Detailed Description
< invention 1 >
First, the invention of the present application 1 will be explained. The invention 1 relates to a broadcasting system that distributes information by light, and a light bulb suitable for use in such a broadcasting system.
As one of the communication systems, a power line communication system is studied. In this power line communication system, information is transmitted using a power line laid in a house or a building and supplying power as it is as a signal transmission medium. Power lines are very popular infrastructure, and communication can be performed between devices connected by power lines. However, communication cannot be performed between devices that are not connected by a power line, such as a portable terminal. The invention provides a broadcasting system for distributing information to devices not connected by the power line, especially to a plurality of devices.
Fig. 1 is a block diagram showing embodiment 1 of the broadcast system according to claim 1 of the present application. In the figure, 101 denotes an information source, 102 denotes a power line modulator, 103 denotes a power line, 104 and 105 denote universal sockets, 106 denotes an LED lighting fixture, 107 denotes a light receiving terminal, 111 denotes an AC/DC converter, 112 denotes a band pass filter, 113 denotes a selector, 114 denotes a superimposing unit, and 115 denotes an LED group. The information source 101 may be configured by a device that outputs various information, such as a tuner or receiver of TV, CATV, radio, cable broadcast, and the like, in addition to a computer. Therefore, the information to be broadcasted may be various information such as video, music, audio, image, and character data. The information to be broadcast may be one or more, where a plurality of information is output.
The power line modulator 102 modulates and multiplexes one or more pieces of information output from the information source 101, and sends the multiplexed information to the power line 103 after superimposing the power waveform. In general power line communication, a demodulation device is often provided to realize bidirectional communication, but the demodulation device is not necessary because of unidirectional communication in a broadcasting system. In this example, multiplexing is performed by frequency division as an example of a method of multiplexing information.
The power line 103 is generally an electric wire laid indoors or outdoors. The power line 103 can use an existing power line. In addition, universal sockets 104, 105 and the like are provided on a wall surface or the like in order to receive power supply from power line 103. The universal sockets 104, 105 can also use existing sockets. In the example shown in fig. 1, the power line modulator 102 is inserted into the universal socket 104, and the LED lighting fixture 106 is inserted into the universal socket 105 for use. Of course, power line 103 and universal sockets 104 and 105 may be replaced. In this example, ac power used as general commercial power is provided as power supply.
The LED lighting fixture 106 is a lighting fixture connected to the power line 103 for lighting nearby. For example, the device is installed on a ceiling or the like in a room. In addition, the lighting apparatus may be used for various purposes such as spot lighting. In this example, the LED lighting fixture 106 includes an AC/DC converter 111, a band-pass filter 112, a selector 113, a superimposing unit 114, an LED group 115, and the like.
Since LED group 115 needs to be driven by DC power to emit light, AC/DC converter 111 converts AC power supplied from power line 103 into DC power. As the AC/DC converter 111, an existing technique can be used. In addition, the voltage is adjusted in accordance with the operating voltage of the LED group 115. Further, the bandpass filter 112 also supplies electric power necessary for operation. Since the waveform of the modulated information is superimposed on the power line 103 as described above, it is desirable that the waveform of the information does not appear as much as possible on the dc waveform by, for example, a smoothing circuit.
Band-pass filter 112 is provided to extract a signal of information superimposed on power line 103. As described above, in this example, since the respective pieces of information are multiplexed by frequency division, one piece of information can be selectively separated from a plurality of pieces of information by the band pass filter 112 that passes only a specific frequency. Fig. 1 shows an example in which a plurality of bandpass filters having different frequencies to pass are arranged in parallel. Alternatively, the filter may be a band-pass filter capable of changing the frequency band to be passed. Further, the waveform of the information after the separation may be biased, shaped, amplified, or the like.
The selection unit 113 selects one or more filters to be used among the plurality of filters provided in the band-pass filter 112, thereby selecting information distributed by light. The selection may be performed by other methods, such as a configuration in which a control signal transmitted as a specific frequency is selectively demodulated and a filter is selected based on the control signal, instead of manually. Alternatively, the band-pass filter 112 may be configured to be capable of changing the frequency at which the band-pass filter 112 passes, and the selector 113 may be configured to set the band-pass filter 112 with a frequency corresponding to the distributed information. Although the selection unit 113 is provided at the front stage of the band pass filter 112 in fig. 1, it may be provided at the rear stage thereof. When the band to be passed by the band pass filter 112 can be changed, the selection unit 113 may set the band to the band pass filter 112 in accordance with a control signal of a specific frequency. Further, when only information transmitted at a fixed frequency is distributed as the LED lighting fixture 106, the selection unit 113 is not provided, and a filter for passing a fixed frequency band may be provided as the band pass filter 112.
The superimposing unit 114 superimposes the signal of the information extracted by the band-pass filter 112 on the power waveform converted into direct current by the AC/DC converter 111. This allows the voltage applied to the LED group 115 to be changed in accordance with the information signal, and the amount of light or on/off of the LED group 115 to be controlled. For example, when the LED group 115 is turned ON or OFF, the power from the AC/DC converter 111 may be turned ON or OFF according to a signal from the band-pass filter 112.
The LED group 115 is basically an LED light source for illumination, and can be configured by, for example, a large number of white LEDs. Of course, the same applies to a configuration in which red, blue, and green LEDs are combined. The LED group 115 is driven by the power supplied from the superimposing unit 114 and emits light. Since the LED response characteristics are good, information can be distributed by changing the amount of light in response to a signal of the information or by turning on and off the light. In this case, even if the light amount is changed at a high speed or turned on or off, the light amount can be used as illumination as it is because human eyes are not conscious.
The light receiving terminal 107 is a terminal having a light receiving device, which receives light emitted from the LED lighting fixture 106, extracts a signal of information, demodulates the signal, and receives the information. The light receiving terminal 107 may be any device as long as it has a light receiving device, and may be various devices such as an audio device provided with a light receiving device, a display device such as a television, and the like, in addition to a personal computer, a portable terminal, a portable telephone, and the like.
Next, an example of the operation in embodiment 1 of the broadcast system according to claim 1 of the present application will be briefly described. As the information source 101, various contents to be broadcasted are prepared. For example, various information such as TV, CATV, radio, cable broadcast, etc. is prepared in addition to data from a computer according to the use.
One or more pieces of information output from the information source 101 are modulated and multiplexed in the power line modulator 102, superimposed on a power waveform, and sent to the power line 103. Fig. 2 is an explanatory diagram of an example of a signal waveform on an electric wire. In this example, a signal waveform of information is superimposed on an electric waveform by a commercial ac power supply (50Hz/60 Hz). In order to avoid an influence on other devices, the signal waveform of the superimposition information is a smaller waveform than the power waveform. The enlarged view shown in fig. 2(B) shows an example in which information is modulated by BPSK or the like and then superimposed on a power waveform. Power line 103 can use an existing power line. Further, if the information is used separately while obtaining power from the universal outlet, the same information as that of power line communication generally used can be provided.
Power and information are transmitted from the universal outlet 105 to the LED lighting fixture 106 through the power line 103. In the LED lighting fixture 106, power carrying a signal waveform is obtained from the universal outlet 105. Then, on the one hand, the AC/DC converter 111 rectifies the DC power to drive the LED group 115, and sends the rectified DC power to the superimposing unit 114. On the other hand, only a predetermined frequency component is extracted by the filter in the band-pass filter 112 selected by the selection unit 113. In this case, it is preferable to apply a bias voltage or perform waveform shaping or amplification, etc., as necessary.
The signal converted into a direct current power waveform by the AC/DC converter 111 and the information extracted by the band-pass filter 112 is synthesized by the adder 114 and applied to the LED group 115. The voltage applied to the LED group 115 varies according to the signal waveform of the synthesized information. This allows the amount of light emitted from the LED group 115 to change in accordance with the signal waveform of the information, thereby enabling transmission of the information.
The light emitted from the LED group 115 is received by a light receiving element provided on the light receiving terminal 107 side. Then, by extracting the change in the received light amount and demodulating it, information can be acquired at the light receiving terminal 107. In this way, among the information supplied from the information source 101, the information selected by the LED lighting fixture 106 is transmitted together with the illumination light and received by the light receiving terminal 107. In this case, even the light receiving part of the light receiving terminal 107 may not accurately face the LED lighting fixture 106(LED group 115), and a signal of information can be acquired with good communication quality as long as illumination light can be received to some extent. This is because the LED illumination light is used for illumination, and therefore, apparent transmission power is very large. In the case of transmitting signals with the same signal intensity by infrared rays used in the past, the influence on the human body (e.g., eyes) is not avoided, and even in this sense, the transmission of information using light is advantageous.
Although only one LED lighting fixture 106 is shown here, for example, when a plurality of LED lighting fixtures 106 are arranged in the vicinity, the same information is selected and broadcast, so that the shadow can be emphasized, and the movement can be supported. On the other hand, even if there is an LED lighting fixture 106 in the vicinity that selects another information to broadcast, if reception is performed in the vicinity of one LED lighting fixture 106, the influence is reduced due to light attenuation from the other LED lighting fixtures 106. When the information from the information source 101 is modulated, for example, when interference with other LED lighting devices is a problem, modulation methods that are good for interference, such as OOK-RZ (On-Off Keying, Return-to-Zero) and ofdm (orthogonal Frequency Division multiplexing), may be used.
In the example shown in fig. 1, the AC/DC converter 111, the band-pass filter 112, and the like are provided in the LED lighting fixture 106. However, the present invention is not limited to this, and for example, these circuits may be provided in a wall switch for turning on/off the lighting, and a direct current having a waveform on which information is superimposed may be supplied to a portion of the power line from the wall switch to the LED lighting fixture 106. In this case, the switch as the selection unit 113 may be provided on the wall surface together with a switch for turning on/off the illumination. Of course, the arrangement of the respective members is not limited to these examples and may be arbitrary.
Fig. 3 is a block diagram showing embodiment 2 of the broadcast system according to claim 1 of the present application. In the drawings, the same components as those in fig. 1 are denoted by the same reference numerals and description thereof is omitted. Reference numeral 116 denotes a band-pass filter, 117 denotes a determination unit, and 118 denotes a selection unit. In this example, the LED lighting fixtures 106 or the information are assigned with fixed identification information (IP, PN code, etc.) one by one, and only specific information is selected by comparing the identification information and broadcast.
Here, the power line modulator 102 divides a plurality of pieces of information from the information source 101 into packets, adds a header to the head of the packets, and superimposes the packets on the power waveform by time division multiplexing. The header contains identification information.
The LED lighting fixture 106 includes a band-pass filter 116, a determination unit 117, a selection unit 118, and the like, together with the LED group 115 and the AC/DC conversion unit 111. The band-pass filter 116 removes an ac component of electric power to separate a signal component of information. In this example, the signal regarding all of the plurality of pieces of information passes through the band pass filter 116.
The determination unit 117 extracts a header portion from the signal of the information separated by the band pass filter 116, compares the header portion with preset identification information, and determines whether or not the transmitted information should be transmitted by light. When the information is to be transmitted, the selection unit 118 selects a signal of the information portion and outputs the signal to the superimposition unit 114. The signal passed through the selector 118 is superimposed on the power waveform converted into direct current by the AC/DC converter 111 in the superimposing unit 114, and is supplied to the LED group 115. Thereafter, as in the above-described embodiment 1, the LED group 115 changes the amount of light or controls the on/off of the light in accordance with the information signal to transmit information using light. Further, the LED group 115 emits light to illuminate.
In embodiment 2, if identification information is assigned to each LED lighting fixture 106, for example, information to be broadcast can be controlled for each LED lighting fixture 106 on the side of sending the information to the power line 103. Further, by configuring the LED lighting fixtures 106 so as to be capable of setting the identification information, it is possible to select information to be broadcast from each of the LED lighting fixtures 106. In this case, a plurality of pieces of identification information may be set, and a plurality of pieces of information may be selectively transmitted by light.
In embodiment 2 as well, various forms can be adopted as in embodiment 1. The advantages are also similar to those of embodiment 1.
In addition to the above embodiments, instead of selecting information distributed by illumination light, information transmitted through power line 103 may be distributed by using all light, and information may be selected on the receiving terminal side.
Fig. 4 is a conceptual diagram showing an embodiment of a light bulb applicable to the broadcasting system according to claim 1 of the present application. In the figure, 121 is a light bulb, 122 is a base, and 123 is a socket. The example shown in fig. 4 can be applied as a part of the LED lighting fixture 106 in each embodiment of the broadcast system. A conventional lighting apparatus is generally used by mounting a white heat bulb. A lamp socket 123 is provided in advance on a ceiling or the like, and as shown in fig. 4(B), a base 122 of the electric bulb 121 is screwed into the lamp socket 123 to be electrically connected. In this example, the wiring portion up to the power line 103 or the socket 123 is configured to use existing equipment as it is, and as shown in fig. 4(a), the light bulb 121 is accommodated in the LED lighting fixture 106 shown in the above-described embodiment 1 or 2. For example, a portion of the base 122 of the electric bulb 121. In addition, unlike a point light source using a filament like a conventional incandescent light bulb, a large number of LEDs are arranged in a planar shape, and therefore, a circuit portion can be accommodated inside.
By using such a light bulb 121, it is possible to replace a general incandescent light bulb with the light bulb 121 according to the invention of the application 1, and use the light bulb 121 as a transmission source of information by light.
Of course, various shapes of light bulbs used in the past have been used in addition to the shape shown in fig. 4. The shape of the electric bulb 121 according to the invention 1 of the present application is not limited to the shape shown in fig. 4, and may be configured in any shape. For example, the light bulb 121 may be formed in a shape in which LEDs are linearly arranged like a fluorescent lamp.
Next, a number of application examples of the broadcast system according to the invention 1 of the present application will be described. Fig. 5 is an explanatory diagram of the 1 st application example of the 1 st invention of the present application. In the figure, 131 denotes an LED lighting fixture, 132 denotes a work, and 133 denotes a light receiving terminal. Fig. 5 shows an example in which the broadcasting system according to claim 1 of the present invention is applied to an art gallery, a museum, or the like. Works and exhibits (hereinafter, referred to as works 132) are individually illuminated by spotlights in art museums, and the like, and descriptions of the works 132 are attached thereto. As a lighting fixture for illuminating the work 132, the LED lighting fixture 131 of the invention of claim 1 of the present application is used. On the other hand, the explanation information of the work 132 is superimposed on the power line 103 that supplies power to the LED lighting fixture 131 and transmitted. The description information superimposed on the power line 103 at this time is superimposed on the plurality of pieces of work 132 in advance. Then, the LED lighting fixture 131 provided for each work 132 is selectively extracted with the description information about each work, and the description information is sent out by controlling the light amount of the illumination light or by turning on and off the light as described above.
If the viewer takes out the light receiving terminal 133 before the work 132, the light is irradiated to the light receiving terminal 133, and the viewer can refer to the description information of the work 132 by taking out the change in the amount of light or turning on and off the light and demodulating the light. In addition, if the viewer moves to the front of the next work, the description information of the work is transmitted by the light illuminating the work, and the description information of the work can be referred to if referring to the light receiving terminal 133.
In this way, in the LED lighting fixture 131 that transmits the explanatory information of each work 132 to the power line 103 so as to be superimposed on the power waveform and illuminate each work, by selecting the explanatory information of the corresponding work 132 and transmitting it by light, the explanatory information of each work 132 can be presented to the viewer together with the illumination of the work 132.
The specification information of each of the works is not limited to one. For example, when explanatory information in a plurality of languages is provided for each work, a plurality of pieces of explanatory information corresponding to the work 132 to be illuminated are selected by the LED lighting fixture 131 and transmitted by light. Then, the plurality of pieces of explanatory information transmitted by the light are separated and demodulated on the light receiving terminal 133 side, and the explanatory information in accordance with the language specified by the viewer is selected from the separated pieces of explanatory information and presented to the viewer. Alternatively, a plurality of pieces of explanatory information such as the explanatory information for adults and the explanatory information for children may be transmitted by light from the same LED lighting fixture 131 to one work 132. The explanatory information is not limited to the character information, and may be, for example, audio information, images, moving images, or the like. Further, the information may be information obtained by appropriately combining them.
Fig. 6 is an explanatory diagram of a 2 nd application example of the 1 st invention of the present application. In the figure, 141 denotes an LED lighting fixture, 142, 143 denote seats, and 144 denotes light receiving terminals. The 2 nd application example shows an example in which the broadcast system according to the 1 st invention of the present application is applied to an aircraft, a train, a bus, or the like. In the example shown in fig. 6, the LED lighting fixtures 141 are provided for the respective seats, and the respective seats are illuminated. At the same time, the information transmitted through the power line 103 is transmitted by using light. Further, a light receiving terminal 144 is provided on the back surface of the front seat 142, and a passenger seated on the seat 143 can refer to a screen of the light receiving terminal 144. The light emitted from the LED lighting fixture 141 is received by the light receiving terminal 144, and information transmitted by the light is acquired by the light receiving terminal 144. The passenger can select desired information and view the information by operating the light receiving terminal 144.
In particular, in an aircraft including a spacecraft or the like, there is a fear of an influence on an instrument or the like, and it is necessary to avoid the use of radio waves in the aircraft. However, if the light is emitted, there is no influence on the instrument or the like, and there is no influence on the human body. For this reason, as shown in fig. 6, information can be distributed wirelessly. The information may be selected not only by the LED lighting fixture 141 but also by the light receiving terminal 144.
In addition, a direct current is often used as electric power for illumination in an aircraft, a train, a bus, or the like. Therefore, in the configuration shown in fig. 1 or 3, the AC/DC converter 111 is not required. For example, when all information transmitted through the power line 103 is transmitted by light, the bandpass filter 112, the superimposing unit 114, and the like are not necessary, and information can be transmitted by light as long as the LED group is driven without any change by the power of the waveform superimposed with the information supplied from the power line 103.
As described above, the broadcast system according to the invention 1 of the present application shows two application examples. However, the present invention is not limited to these application examples, and can be applied to any application in which information is distributed by light. For example, the system may be used as a distribution system to a personal computer on a desktop in a general office or the like, or may be used for information transmission to various works in a factory. Furthermore, it is possible to distribute television or radio broadcasts in a home, and to view and listen to any room through a portable display. In this case, the selection unit corresponding to the tuner may be provided in the LED lighting fixture, and the selection unit in the LED lighting fixture may be controlled by a television controller or the like to select channels. Further, for example, in a sports field or a program venue where sports are performed, various information on the ongoing sports or programs, information on other venues, and the like may be transmitted while being superimposed on the illumination light, and received by a portable terminal or the like of the viewer to acquire the information.
As described above, according to the invention of the present application 1, it is possible to distribute a large amount of information by light using a device for illumination as it is. In this case, it is not necessary to provide a separate transmission device as in the conventional case, and it is not necessary to newly lay a communication cable or the like. Thus, the broadcast system can be constructed at low cost. Further, it is possible to construct a safe broadcasting system without the influence of eye safety or the like on a human body as in infrared rays, and without the limitation of application to an aircraft or the like as in radio waves.
< invention 2 >
Next, the invention of the present application 2 will be explained. The 2 nd invention is for realizing bidirectional communication by light, at least using illumination light on its one direction (downlink).
As described in the above-mentioned invention 1, the communication using the illumination light has excellent characteristics because a large amount of electric power can be used for communication in signal transmission (hereinafter, referred to as downlink) from the illumination device to the mobile terminal. However, conventional illumination light communication is only one-way downlink, and signal transmission from a mobile terminal to an illumination device (hereinafter referred to as uplink) has not been studied yet. In the case of performing general communication other than broadcasting, it is necessary to exchange various data between communication apparatuses, including exchange of control signals for performing handover such as ACK or NACK. For this reason, the uplink is very important.
Fig. 7 is a schematic configuration diagram showing embodiment 1 of invention 2 of the present application. In the figure, reference numeral 201 denotes an illumination-side communication device, 202 denotes a terminal-side communication device, 211 denotes a modulation unit, 212 denotes an illumination light source, 213 denotes a light receiving unit, 214 denotes a filter, 221 denotes a light receiving unit, 222 denotes a light emitting unit, and 223 denotes a processing unit. The illumination-side communication device 201 is used as a lighting fixture for surrounding illumination, and includes an illumination light source 212 that emits light and illuminates. Although the light source is LED here, it is needless to say that the LED is not limited to this, and an LD or another light emitting element with a high response speed may be used.
The illumination-side communication device 201 further includes a modulation unit 211 and a light receiving unit 213 as a configuration for performing illumination light communication. The modulation unit 211 is provided for downlink, and controls power for driving the illumination light source 212 based on data to be transmitted. Thereby, the light amount or on/off of the illumination light source 212 is controlled, and light modulated based on data is emitted. By receiving the modulated illumination light at the terminal communication device 202 described later, data transmission (downlink) from the illumination communication device 201 to the terminal communication device 202 can be performed.
The modulation scheme can be OOK (ON-OFF Keying) or BPSK (binary phase shift Keying). The LEDs that control the amount of light or on/off may be all of the illumination light sources 212 arranged to illuminate, or may be used only partially. Further, since the LED has a high-speed response characteristic as described above, a change in light quantity or turning on and off of the LED is not perceived by human eyes, and continuous light emission is perceived. Thus, even if data transmission is performed, the illumination light source 212 is also responsible for another task of illumination.
The light receiving unit 213 is provided to receive modulated light (infrared light, visible light, ultraviolet light, or the like) emitted from the terminal-side communication device 202, and includes a light receiving element such as a photodiode, for example. In this example, a filter 214 is provided to selectively receive the modulated light emitted from the terminal-side communication device 202. For example, when receiving infrared rays, a filter 214 that transmits infrared rays may be provided. Of course, the filter 214 may not be provided. The received light is converted into an electrical signal, and the data is demodulated and output from the terminal-side communication device 202.
The data transmitted by the illumination light may be data received from the outside or data held or generated in the illumination-side communication device 201. The data received by the light receiving unit 213 may be processed in the illumination-side communication device 201, in addition to being output to the outside.
The terminal-side communication device 202 may be any terminal device, and may include the light receiving unit 221, the light emitting unit 222, the processing unit 223 that performs various processes in the terminal device, and the like as a configuration for performing illumination light communication. The light receiving unit 221 receives the modulated light emitted from the illumination-side communication device 201, demodulates the light, and transmits the demodulated light to the processing unit 223. This makes it possible to receive data transmitted from the illumination-side communication device 201 by means of the illumination light, thereby making it possible to perform downlink transmission.
The light emitting unit 222 includes a light source such as an LED or an LD, a control circuit for driving and controlling the light source, and the like, receives data to be transmitted from the processing unit 223, controls the amount of light or on/off of the light source based on the data, and emits modulated light. The modulation method is arbitrary. The light emitting light can be infrared light, visible light, ultraviolet light, or the like. The modulated light is received by the light receiving unit 213 of the illumination-side communication device 201 described above, thereby realizing an uplink.
As described above, in the illumination-side communication device 201, the illumination light source 212 illuminates the surroundings and modulates the illumination light based on data, thereby transmitting the data by the illumination light. The light receiving unit 221 of the terminal-side communication device 202 receives the illumination light, and thus can receive data transmitted from the illumination-side communication device 201. This is done for downlink. In addition, in the terminal-side communication device 202, modulated light is emitted from the light emitting section 222 based on data to transmit the data. The modulated light is received by the light receiving unit 213 of the illumination-side communication device 201, and thus the data transmitted from the terminal-side communication device 202 is received by the illumination-side communication device 201. This is done for uplink. In this way, both the downlink and the uplink can communicate by light, and bidirectional communication using light can be realized.
For example, the terminal-side communication device 202 is a portable terminal device such as a node personal computer, a PDA, or a mobile phone, and does not need a connection cable. In particular, a PDA with a camera, a mobile phone, or the like can use the camera as the light receiving unit 221. Further, the present invention can be used in an environment where communication by radio waves is limited, for example, an environment where a user in a hospital or a train, an aircraft, a spacecraft, a leader lives, and the like, and does not require permission. Of course, the present invention can be used in various environments such as general offices, shops, homes, public facilities, and the like. The present invention is not limited to indoor use, and can be used in various applications such as neon signboards, advertisement lighting, vehicle-to-vehicle communication in traffic systems, and vehicle-to-vehicle communication in facilities on roads.
Further, since the wavelength of light is short, communication at a very high speed higher than radio waves can be performed. Furthermore, generally, lighting fixtures are widely installed, and it is needless to say that lighting can be performed even in an environment where a terminal device is used. Since the lighting-side communication device 201 can be installed and communicate by using the lighting fixture, the installation cost can be extremely reduced.
In an environment where a plurality of lighting apparatuses are arranged, such as an office, the lighting apparatuses may be used as the lighting-side communication device 201, and the plurality of lighting-side communication devices 201 may be arranged. In this case, the plurality of lighting-side communication devices 201 can receive the light emitted from the 1 terminal-side communication device 202. By receiving light in the plurality of illumination-side communication devices 201 in this manner, communication quality can be improved. Even when a shadow is generated by, for example, passage of a person, and light cannot be received by 1 lighting-side communication device 201, the problem of the shadow can be solved by receiving light by another lighting-side communication device 201.
Next, several main modifications of embodiment 1 will be described. Fig. 8 is an explanatory diagram of a modification of the light receiving unit 213 of the illumination-side communication device 201. In the figure, 231 is a two-dimensional sensor and 232 is a lens. The two-dimensional sensor 231 can be used as the light receiving unit 213 of the illumination-side communication device 201, and can be configured to form a substantial image on the light receiving surface by the lens 232. In this configuration, for example, the light emitted from the terminal-side communication device 202 is imaged on the light receiving surface of the two-dimensional sensor 231, and the light emitted from the terminal-side communication device 202 is received by some of the plurality of light receiving units provided in the two-dimensional sensor 231. In this case, since the other light receiving unit receives the ambient light, it is possible to remove background noise and the like by using it, and high-quality communication can be performed.
For example, when a plurality of terminal-side communication devices 202 and 202 'exist in the light receiving area, the light emitted from the terminal-side communication devices 202 and 202' are imaged at different positions in the two-dimensional sensor 231 as shown in fig. 8. For this purpose, data from the respective terminal-side communication devices 202 and 202' can be received in parallel. Naturally, the same applies to the case where there are 3 or more terminal-side communication apparatuses.
Further, in an environment where a plurality of illumination-side communication devices 201 are installed, light emitted from the respective terminal-side communication devices 202, 202' can be received by the two-dimensional sensors 231 installed in the respective illumination-side communication devices 201. In this case, the light receiving point of the two-dimensional sensor 231 can be identified by the light receiving position on the two-dimensional sensor 231, the installation position of the illumination-side communication device 201, and the like, and the communication quality can be improved.
Fig. 9 is an explanatory diagram of a modification of the light emitting unit 222 of the terminal-side communication device 202. In the figure, 241 denotes a tracking unit, 242 denotes an LED light source, 243 denotes a mirror surface, and 244 denotes a lens. In the basic configuration shown in fig. 7, when the LED light source 242 is used as the light source of the light emitting section 222 of the terminal-side communication device 202, the emitted light diverges and the amount of light that can be received by the illumination-side communication device 201 decreases. In the example shown in fig. 9, a mirror 243 and a lens 244 are provided to prevent such divergence and convergence of the emitted light. By providing such an optical system, the light emitting efficiency of the LED light source 242 can be favorably directed to the illumination-side communication device 201, and favorable communication can be performed. Of course, when an LD or the like having sharp directivity is used as the light source, the mirror 243, the lens 244, or the like is not necessary.
In addition, when the light beam is converged or the LD is used as the light source, the communication quality is degraded or the communication is not possible if the light beam is not properly irradiated to the light receiving unit 213 of the illumination-side communication device 201. For this purpose, in the example shown in fig. 9, a tracking unit 241 for directing the light beam toward the light receiving unit 213 of the illumination-side communication device 201 is provided. The tracking unit 241 may be configured to be operated automatically by illumination light or the like or under control from the terminal device main body, or may be configured to be controlled from the illumination-side communication device 201 in a downlink, in addition to being provided with a movable mechanism that can manually change the direction of the light beam.
The above description has been made of a modification in the light receiving unit 213 of the illumination-side communication device 201 and a modification in the light emitting unit 222 of the terminal-side communication device 202. The invention of the present application 2 is not limited to these examples. For example, the configuration shown in fig. 8 can be applied to the light receiving unit of the terminal-side communication device 202. Thus, different data can be transmitted in parallel by the illumination light from the plurality of illumination-side communication devices, and separated and received by the terminal-side communication device 202.
In addition, the data transmitted from the lighting-side communication device 201 and the received data may be transmitted by superimposing the data on a power waveform using a power line that supplies power for lighting, in addition to the dedicated data line. Of course, it goes without saying that various modifications other than these are possible.
Fig. 10 is a schematic configuration diagram showing embodiment 2 of invention 2 of the present application. In the drawings, the same portions as those in fig. 7 are denoted by the same reference numerals, and redundant description thereof will be omitted. Reference numeral 224 denotes a reflection modulation unit. In embodiment 1 described above, an example is shown in which the terminal-side communication device 202 is provided with the light emitting unit 222 for uplink and the terminal-side communication device 202 emits light. In contrast, embodiment 2 shows a configuration in which the illumination light used in the downlink is used as it is, and the reflected light is used in the uplink. As described above, the illumination light is very large power, and communication can be performed more reliably by using it for the uplink. Further, since the terminal-side communication device 202 does not need to be provided with the light emitting unit 222, power consumption of the terminal-side communication device 202 can be greatly suppressed, and power saving can be greatly facilitated. Since the configuration of the illumination-side communication device 201 is the same as that of the above-described embodiment 1 and its modified example, the description thereof is omitted here, and the illustration of the modulator 211 is also omitted. The light receiving unit 221 of the terminal-side communication device 202 is also similar to that of embodiment 1 and its modified example.
As a configuration for using illumination light on the uplink, the terminal-side communication device 202 is provided with a reflection modulation unit 224. The reflection modulation unit 224 reflects the illumination light and transmits the reflected light modulated according to the data transmitted in the uplink.
Fig. 11 is an explanatory diagram of an example of a configuration in which a mirror is used as the reflection modulation section 224. In the figure, 251 denotes a mirror, 252 denotes a shutter, 253 denotes a shielding wall, and 254 denotes a tracking unit. As a means for reflecting the illumination light, it is sufficient to simply use the mirror 251 and provide the same tracking section 254 as the tracking section 241 in the modification shown in fig. 9 to control the reflection direction. Here, as a modulation method, the shutter 252 is used, and can transmit/block incident light to the mirror 251 and reflected light from the mirror 251. The shutter 252 is, for example, a liquid crystal shutter, and can modulate by controlling the alignment of liquid crystal based on data and performing switching control of reflected light. Of course, other modulation methods are possible, and for example, modulation can be performed by changing the reflection direction of the mirror surface based on only data. That is, since the amount of light incident on the light receiving unit 213 of the illumination-side communication device 201 changes by changing the reflection direction of the mirror surface, data can be extracted if the change is detected. In this case, the tracking unit 254 may also serve as a modulation device, for example.
In the example shown in fig. 11, a shielding wall 253 is disposed around the mirror 251. This is provided to prevent light from a light source other than the illumination-side communication device 201 performing communication from being reflected by the mirror 251 and entering the eyes of the user to be dazzled. When the illumination light source 212 and the light receiving unit 213 of the illumination-side communication device 201 are disposed close to each other, the light from the illumination light source 212 may be simply reflected to return to the light receiving unit 213, and thus reflection of the other light is not necessary. In order to prevent such unwanted reflection, a shielding wall 253 is provided. The amount of reflected light can also be increased by making the inner surface of the shielding wall 253 a mirror surface. Of course, the shielding wall 253 may not be provided.
In addition, a plurality of units shown in fig. 11 may be arranged in addition to the single use of the units.
The reflection modulation unit 224 can use CCR (inner Cube ref) as a device for reflecting illumination light-ector). FIG. 12 is an explanatory diagram of the outline of CCR. The CCR has a shape with 3-sided reflective surfaces facing inward and perpendicular to each other. For example, as shown in fig. 12, the light-reflecting surface is obtained by using 3 inner surfaces perpendicular to each other, which form 1 vertex of a cube or a cube, as the reflecting surface.
As a feature of the CCR, there is a characteristic of emitting light toward an incident direction of light. Thus, the illumination light is reflected toward the light source of the illumination light if the illumination light is incident. Although the illumination light is used for the downlink in the invention 2 of the present application, the illumination light used for the downlink is reflected, and thus can be used for the uplink as it is. In particular, since the light is reflected toward the illumination light source, the reflected light can be received by providing the light receiving unit 213 close to the illumination light source of the illumination-side communication device 201. Further, since the reflected light having high directivity and high intensity enters the light receiving unit 213 of the illumination-side communication device 201, there is an advantage that it is less susceptible to the influence of the ambient light. The illumination-side communication device 201 may be provided at an arbitrary position, and even if the terminal-side communication device 202 is present at an arbitrary position, the reflected light is reflected toward the illumination-side communication device 201.
Fig. 13 is an explanatory diagram of an example of a modulation method in the case of using CCR. In the figure, 261 is CCR, 262 is a shutter, 263 is a dielectric, and 264 is a regulator. As described above, several methods for reflecting the illumination light toward the illumination-side communication device 201 by the CCR and modulating the reflected light in accordance with data are shown. Fig. 13(a) shows an example in which the shutter 262 is disposed in front of the CCR and modulated. The shutter 262 can be configured by, for example, a liquid crystal shutter using a liquid crystal display device. The liquid crystal shutter switches transmission and blocking of light by changing the orientation of liquid crystal in response to application of a voltage. When the liquid crystal shutter is used, for example, the liquid crystal shutter is controlled to transmit light, as described above, illumination light from the illumination-side communication device 201 enters the CCR261, and reflected light is directed to the illumination-side communication device 201. On the other hand, when the liquid crystal shutter is controlled to block light, both the incident light and the reflected light to the CCR261 are blocked, and the light receiving unit 213 of the illumination-side communication device 201 cannot receive the reflected light. This makes it possible to control the opening and closing of the reflected light by controlling the orientation of the liquid crystal shutters. By performing this switching control in accordance with the data, the modulated reflected light can be transmitted to the illumination-side communication device 201. Of course, there are various liquid crystals, and these various liquid crystals can be suitably used. For example, the transmission and reflection of light may be switched. In this example, a liquid crystal shutter is used as the shutter 262, but any shutter mechanism that can control the entrance and exit of the illumination light and the reflected light to and from the CCR261 can be used as long as it is configured as a shutter mechanism.
In the example shown in fig. 13B, the dielectric 263 is disposed close to (λ/3) in a part or the whole of the mirror surface constituting the CCR261, whereby the amount of total reflection on the inner surface is attenuated. The amount of reflected light in CCR261 can be controlled by changing the position of the dielectric in accordance with data, and the thus modulated reflected light can be sent to illumination-side communication device 201. This method uses the coherence of light, and is limited to the case where an LD is used as a light source of the illumination-side communication device 201.
In the example shown in fig. 13(C), an actuator 264 is attached to 1 surface of the mirror surface constituting the CCR261, and the mirror surface is changed in accordance with the data. For example, the relationship of returning the reflected light to the direction of the incident light can be broken by changing the angle of the mirror surface or tilting the mirror surface to change the reflection angle of light between the mirror surfaces in CCR 261. Such control can be performed in accordance with data to send the modulated reflected light to the illumination-side communication device 201. As the actuator 264, various configurations using deformation by a piezoelectric element or the like can be applied, in addition to driving by a mechanical microcomputer or the like.
Fig. 14 is an explanatory diagram of an example of incident light to the reflection modulation section 224 and the modulated reflected light. The light incident on the reflection modulation unit 224 as described above is modulated illumination light emitted from the illumination-side communication device 201. Thus, the amount of light is controlled or turned on and off according to data transmitted through the downlink. If the reflection is performed by CCR261 as it is, data in the case where the downlink is also superimposed on the reflected light remains unchanged. However, there is almost no problem in the case where the data transmission rate of the uplink is slower than the data transmission rate using the downlink. For example, in the case where the light quantity of illumination light changes at a high speed as shown in fig. 14(a), if the data transmission speed of the uplink is slow, the light quantity of illumination light changes several times in 1 data transmission. For example, when the incident light is modulated as described in fig. 13 and reflected by CCR261, the average light amount of the bright portion and the dark portion existing in 1 data transmission is received by light receiving unit 213 of illumination-side communication device 201. On the other hand, when CCR261 is not used for reflection toward the light source, the average light amount cannot be received by light receiving unit 213 of illumination-side communication device 201. Thus, even if the data of the downlink is used for the uplink with the illumination light left unchanged, the data can be transmitted well.
On the other hand, when the data transfer rate in the downlink is comparable to or lower than the data transfer rate in the uplink, the reflected light of the illumination light can be used in the uplink without a time when the illumination light is completely blocked. Fig. 14(B) shows a case where the data transmission rates of the downlink and the uplink are the same. In this example, a subcarrier BPSK is used as a downlink data modulation scheme. In this case, since the illumination light amount does not continue to be 0 during the transmission time of 1 data, even if modulation using a switch for uplink is performed, uplink data can be received by the light receiving unit 213 of the illumination-side communication device 201 in accordance with a change in the light receiving amount.
In this way, even if the illumination light is modulated, the uplink from the terminal-side communication device 202 to the illumination-side communication device 201 can be realized by reflecting the modulated illumination light and modulating it in accordance with the uplink data. The illumination light is large in power, and also has a large power with respect to its reflected light. Thereby enabling high-quality communication also with respect to the uplink. In addition, in the configuration using CCR261, since the reflected light is returned to the light source of the incident light, it is not necessary at all to perform tracking, and uplink can be realized with a simple configuration. Further, there is an advantage that synchronization with the downlink is not necessary. Further, when CCR261 is used, there is an advantage that light is rarely incident on the eyes of the user due to stray reflection or the like, and glare hardly occurs.
Fig. 15 is an explanatory diagram of an example of a usage form of an illumination light communication device in which the CCR is mounted as the reflection modulation unit 224, and fig. 16 is an explanatory diagram of an example of a method of combining reception signals in a plurality of illumination-side communication devices that are the same. In the figure, reference numeral 271 denotes a light receiving element, 272 denotes a delay correction unit, 273 denotes a combining unit, and 274 denotes a demodulation unit. As described above, CCR has a characteristic of returning reflected light toward a light source, and this characteristic is also the same when light enters from multiple directions. For example, as shown in fig. 15, when illumination light is emitted from each of the plurality of illumination-side communication devices 201, 201 ', 201 ″ and enters the terminal-side communication device 202, the illumination light from the illumination-side communication device 201 is reflected toward the illumination-side communication device 201 by the CCR provided in the terminal-side communication device 202, the illumination light from the illumination-side communication device 201 ' is reflected toward the illumination-side communication device 201 ', and the illumination light from the illumination-side communication device 201 ″ is reflected toward the illumination-side communication device 201 ″. Thereby, the uplink data from the terminal-side communication device 202 is received by the plurality of lighting-side communication devices 201, 201', 201 ″.
In the plurality of lighting-side communication devices 201, 201', 201 ″, data can be received reliably by combining the electrical signals obtained by receiving light from each of the plurality of lighting-side communication devices. Fig. 16 shows an example of the circuit configuration at this time. The light receiving elements 271 provided in the light receiving portions 213 of the respective illumination-side communication devices 201, 201', 201 ″ convert received light into electrical signals. The delay correction unit 272 corrects the electric signals from the light receiving element 271 by the delay amounts individually set for the respective illumination-side communication devices 201, 201', 201 ″, and then the electric signals are combined by the combining unit 273. The synthesis can be performed by, for example, simply adding, or by obtaining average power or by weighting and synthesizing. The higher the signal strength, the higher the weight. The data transmitted from the terminal-side communication device 202 can be acquired by demodulating the combined electrical signal in the demodulation section.
In this way, since the uplink data can be transmitted to the plurality of lighting-side communication devices, even if a shadow occurs in which light does not reach one lighting-side communication device due to, for example, passage of a person, light is received by another lighting-side communication device, and thus communication can be performed without problems. In this case, a mechanism for tracking CCR or the like is not necessary, and a shadow that is a fault of optical communication can be solved with a simple configuration. Although fig. 15 shows 3 illumination-side communication devices, the present invention is not limited to this, and the same is true even if 2 or 4 or more illumination-side communication devices are used.
Although one CCR is described in the above description, the same applies to a configuration in which a plurality of CCR are arranged, and for example, the CCR can be arranged in 2-dimensional form. When a plurality of CCR are arranged, as shown in fig. 13, a configuration for modulation is provided for each CCR261, and all of the configurations are controlled in the same manner, so that the operation can be performed in the same manner as when there is one CCR. For example, in the case of the configuration in which modulation is performed by the shutter 262 as shown in fig. 13(a), a common shutter 262 may be provided for a plurality of CCR.
In the case where a plurality of CCR are configured in this way, modulation control may also be performed on one or more CCR one by one. With such a configuration, parallel data transmission from the terminal-side communication device 202 is possible. Fig. 17 is an explanatory diagram of a configuration example in which parallel transmission is possible in the reflection modulation unit 224 of the terminal-side communication device 202. In the figure, 281 is the CCR array and 282 is the lens. The CCR array 281 is configured with a plurality of CCR, and may be configured to perform modulation control on one or more CCR by one. As for each CCR in CCR array 281, if modulation control using shutter 262 is performed as shown in fig. 13(a), for example, controllable shutter 262 may be provided for one or more CCR one by one. Further, for example, as shown in fig. 13(C), if the configuration is such that the mirror surface of CCR is changed, the same configuration can be provided for each CCR, and control can be performed for one or a plurality of CCR.
A lens 282 is provided on the incident (exit) side of the CCR array 281, and is adjusted so that the illumination light from the illumination-side communication devices 201, 201' is substantially imaged on the mirror surface of the CCR or its vicinity. In this configuration, for example, the light emitted from the illumination-side communication devices 201, 201' is incident only on a respective part of the CCR in the CCR array 281. Then, according to the characteristics of CCR, a part CCR of the illumination light from the illumination side communication device 201 is incident on returns the reflected light to the illumination side communication device 201, and a part CCR of the illumination light from the illumination side communication device 201 'is incident on returns the reflected light to the illumination side communication device 201'. In this case, the same data can be transmitted to the plurality of illumination-side communication devices 201 and 201' as described above with reference to fig. 15 by performing modulation control on the CCR on which the respective illumination lights are incident in the same manner.
Here, the CCR on which the respective illumination lights are incident may be modulated and controlled based on different data. That is, it is possible to control so that CCR of return reflected light of the illumination-side communication device 201 is modulated and controlled based on 1 st data with respect to illumination light from the illumination-side communication device 201 being incident, and CCR of return reflected light of the illumination-side communication device 201 'being incident and modulated and controlled based on 2 nd data different from 1 st data with respect to illumination light from the illumination-side communication device 201'. This enables the 1 st data to be transmitted to the lighting communication device 201 and the 2 nd data to be transmitted to the lighting communication device 201'. These data can be sent in parallel and can be transmitted in parallel.
In addition to the determination of CCR of the incident illumination light, the determination of the position of the illumination-side communication device may be made by configuring a simple light receiving element to be arranged together with CCR, by combining a light receiving element with a mirror surface of CCR, or by configuring the light receiving unit 221 as the terminal-side communication device 202 with a two-dimensional sensor, a lens system, or the like. Of course, other methods may be used.
As described above, the example in which the reflected illumination light is used for the uplink is described as embodiment 2. In embodiment 2 as well, the illumination-side communication device 201 can be installed in the same manner as the illumination device used in general, and the terminal-side communication device 202 is preferably a portable terminal device such as a personal computer, a PDA, or a mobile phone, as in embodiment 1 described above. The present invention can be used in various applications such as general offices, stores, homes, public facilities, and usage environments in which communication by radio waves is limited, for example, environments in which users of hospitals, trains, aircrafts, spacecrafts, and pilots live, and can also be used in various applications such as neon signboards, advertisement lighting, and vehicle-to-vehicle communication and road-to-vehicle communication in a transportation system, without being limited to indoor use.
In addition, in embodiment 2, various modifications similar to those in embodiment 1 can be made. The configuration of the light receiving unit 213 in the illumination-side communication device 201 shown in fig. 8 and the configuration of the light emitting unit 222 in the terminal-side communication device 202 shown in fig. 9 can be applied, and data transmitted from the illumination-side communication device 201 and data received can also be communicated by the power line. Of course, it is needless to say that various modifications other than these are possible.
As described above, in conventional illumination light communication, only downlink light is used, but according to the invention of claim 2 of the present application, uplink light can be used, and bidirectional communication using light is possible.
In addition, the illumination light can be reflected for use in the uplink, and in this case, high-quality communication can be performed using high-power illumination light. Further, by using the CCR, an uplink using light can be realized with a simple configuration without tracking.
< invention 3 >
Next, the invention of the present application 3 will be explained. In the case of communication using illumination light, there is a problem that communication cannot be performed if the illumination is turned off. In the invention 3, infrared communication is used in combination to enable communication even when the lamp is turned off. First, a general structure is shown for a Light Emitting Diode (LED) for illumination used in the 3 rd aspect of the present application.
Fig. 25 is a configuration diagram of an example of a general white LED. In the figure, 331 and 341 are LED elements, 332 is a red light emitting element portion, 333 is a green light emitting element portion, 334 is a blue light emitting element portion, 342 is a light emitting element portion, and 343 is a phosphor. An example of the white LED shown in fig. 25(a) is a configuration in which a red light emitting element portion 332 that emits red light, a green light emitting element portion 333 that emits green light, and a blue light emitting element portion 334 that emits blue light are arranged in parallel in the LED element 331. The red, green, and blue lights emitted from the respective light emitting element portions are mixed and viewed as white light.
In the example of the white LED shown in fig. 25(B), a light-emitting element portion 342 for blue or ultraviolet is provided in the LED element 341, and a phosphor 343 is provided around the light-emitting element portion 342. In the LED element 341, like a fluorescent lamp, when blue light or ultraviolet light emitted from the light emitting element portion 342 is irradiated to the fluorescent agent 343, the fluorescent agent 343 emits white light. Whereby white light is emitted.
Such a single LED element is generally used as an array of a plurality of LEDs so that the amount of light emitted for illumination is small. In the following description, the LED array is sometimes referred to as an LED. Such an LED array is used for, for example, a part of traffic signals, a rear lamp of an automobile, a desk lamp, a foot lamp, and the like. LEDs have excellent characteristics such as long life, small size, and low power consumption compared to conventional illumination light sources such as incandescent bulbs and fluorescent lamps, and are expected to be future illumination light sources.
Further, since a light emitting element such as an LED does not require a warm-up time, response speed is very high. In view of the rapid response speed and the capability of electrical control, studies have been made to superimpose a signal on illumination light using an LED so as to have a signal transmission function.
In the case of lighting, lighting fixtures are widely installed on ceilings, wall surfaces, and the like, or light is irradiated from a high position by constructing an electric pole or the like, and therefore shadows are not often generated in a certain area. Generally, in wireless communication including light, a shadow in which signal intensity is reduced in a shadow of an object to cause a failure in communication becomes a problem. However, since the illumination is often arranged so as not to appear as a shadow as described above, the use of illumination for communication means that communication can be performed without generating a shadow. Further, since a large amount of illumination power can be used, there is an advantage that communication quality is also improved.
However, since the illumination light communication uses illumination light, there is a problem that the illumination light cannot be used when turned off. Of course, although lighting may be performed even when lighting is not necessary, lighting may be performed when not necessary without obtaining understanding of the user from the viewpoint of energy saving, and lighting may not be performed at night or the like, for example. However, communication is not possible when the lamp is turned off, and communication is not possible when the projector is not in use, at night, or when the projector is used.
On the other hand, since infrared light communication has been widely used in the past, standardization of IrDA and the like has been advanced. In infrared light communication, there is a fear that human body is affected by eye safety and the like, and thus, high-power communication cannot be performed. Further, due to the characteristics of light, if an obstacle such as a user exists, the communication quality is degraded, and the communication is easily affected by shadows. For this reason, the use range is narrow and stable use may not be possible.
In order to solve such a problem, a communication device usable even when the lamp is turned off or the like is realized by using the illumination light and the infrared light in combination with the following configuration.
Fig. 18 is a block diagram showing embodiment 1 of the illumination light communication device according to claim 3 of the present application. In the figure, 311 denotes an optical modulation unit, 312 to 314 denote switches, 315 denotes a power divider, 316 denotes an illumination unit, 317 denotes a communication unit, 321 denotes an information terminal, and 322 denotes a light receiving unit. The illumination unit 316 is provided with a light source for illuminating by light emission. A semiconductor light emitting element having high-speed response characteristics such as a white LED element is used as a light source, and illumination light communication can be performed by turning on and off or controlling the amount of light. The communication unit 317 can transmit data by an optical communication method other than the illumination light, for example, infrared light communication. As described later, the illumination section 316 and the communication section 317 may be formed in the same element. Of course, it may be configured as a separate device.
The light modulation section 311 and the power divider 315 correspond to the modulation device of the invention of claim 3, and modulate the illumination light by controlling the amount of light or the blinking of the illumination section 316 in accordance with the data. In this example, the optical modulation unit 311 modulates the input data in accordance with a predetermined modulation scheme, and the modulated data is superimposed on the power waveform and input to the power divider 315 via the switch 313, and is also input to the communication unit 317 via the switch 314. Thereby, ON/OFF control or light amount control is performed for the illumination section 316 and the communication section 317.
The power distributor 315 mainly supplies power to the lighting unit 316. At this time, when power is supplied to the illumination unit 316, the modulated data transmitted from the light modulation unit 311 through the switch 313 is superimposed on the power.
The switches 312 to 314 constitute the switching device of the invention 3 of the present application, and switch ON/OFF of the respective switches in accordance with an instruction from the outside such as an instruction to turn ON or OFF the lighting device. The switch 312 switches ON/OFF of power supply to the power distributor 315, and switches lighting ON and OFF of illumination. The switch 313 switches whether or not modulated data is supplied to the power distributor 315, and when the illumination unit 316 illuminates, switches whether or not data is transmitted by the illumination light (illumination light communication). The switch 314 switches whether or not modulated data is supplied to the communication unit 317. Either or both of the switches 312 and 313 are turned ON.
Fig. 19 is an explanatory diagram of an example of the on/off operation of the switches 312 to 314. When the switches 312 are turned on and the switch 313 is turned off by turning on and off the switches 312 to 314, if the switch 314 is turned on, communication is performed by the communication unit 317 while illumination is performed by the illumination unit 316 as shown in fig. 19. In fig. 19, the infrared light communication is described as "infrared light communication" as the communication performed by the communication unit 317, but the communication performed by the communication unit 317 is not limited to this. If the switches 312 and 313 are set to the same value, if the switches are turned off, only illumination is performed and communication is not performed as shown in fig. 19 (c). The illumination light in this case is not used for communication. When the switch 312 is turned off and the switch 313 is turned on, if the switch 314 is turned on, communication is performed by the illumination light while illumination is performed by the illumination section 316, and the same data is also communicated by the communication section 317 as shown in fig. 19 (c). In the same case, if the switch 314 is turned off, the illumination by the illumination section 316 and the communication by the illumination light are performed as shown in fig. 19 (r). When the switches 312 and 313 are turned off, the illumination section 316 is not used, and when the switch 314 is turned on, communication by the communication section 317 is performed as shown in fig. 19 (fifthly), and when the switch 314 is turned off, neither illumination nor communication is performed as shown in fig. 19 (sixthly).
For example, when communication is performed when illumination is necessary, communication via the communication unit 317 or communication using illumination light via the illumination unit 316 can be performed by turning on the switch 312, turning off the switch 313, and turning on the switch 314 as shown in fig. 19 (r), or by turning off the switch 312, turning on the switch 313, and turning on or off the switch 314 as shown in fig. 19 (c) and (r). When the illumination is not necessary, communication can be performed through the communication unit 317 by turning off the switches 312 and 313 and turning on the switch 314 as shown in fig. 19.
Thus, communication using the illumination light can be performed when the illumination is used, and communication can be performed even when the illumination is turned off. As described above, in the case of using the infrared light communication as the communication method of the communication section 317, since infrared light is not seen by eyes, a person does not perceive brightness even when communication is performed, and communication is possible in a state where illumination is turned off.
Fig. 20 is a schematic view showing an example of the illumination device of the invention 3 which is suitably used in the illumination light communication device of the invention 3, and fig. 21 is an explanatory view of an application example of the illumination device of the invention 3 which is an example of the illumination device of the invention 3. In the drawings, the same portions as those in fig. 25 are denoted by the same reference numerals, and redundant description thereof will be omitted. Reference numeral 335 denotes an infrared light emitting element portion. A general illumination LED as shown in fig. 25 naturally emits only visible light, but does not emit infrared light. Therefore, when infrared light communication is performed by the communication unit 317 as described above, an LED for infrared light needs to be separately provided as the communication unit 317. Of course, the illumination section 316 and the communication section 317 may be provided with LEDs, respectively, but they may have similar structures and be integrally formed. An example thereof is shown in fig. 20.
In the example shown in fig. 20, as shown in fig. 25(a), an infrared light emitting element portion 335 is provided on an LED that emits red, green, and blue 3-color light to become white light. Even if the size of the package in which the infrared light emitting element portion 335 is provided is almost unchanged from that of a general LED, the width is several mm and the height is several mm.
When such an illumination element is applied to an illumination light communication device, as shown in fig. 21, the red light emitting element portion 332, the green light emitting element portion 333, and the wiring connecting the light emitting element portion 334 are connected to the power distributor 315 for power supply at the time of illumination and for power supply modulated at the time of illumination light communication. The infrared light emitting element portion 335 may be connected to the light modulation portion 311 via the switch 314, and may be modulated and driven by the light modulation portion 311 when the switch 314 is turned off. The common electrode may be grounded together with the optical modulation unit 311, the power divider 315, and the like.
In normal illumination, the red light emitting element portion 332, the green light emitting element portion 333, and the blue light emitting element portion 334 emit light, and white illumination light is visually emitted by 3 colors of light. Illumination light communication can be performed by modulating the illumination light at high speed. Although the infrared light emitting element portion 335 is invisible from the view even when it emits light, wireless communication using infrared light can be performed by modulating the emitted light at a high speed.
By switching the switches 312 to 314 as described above, it is possible to switch the illumination light communication in which the red light emitting element portion 332, the green light emitting element portion 333, and the blue light emitting element portion 334 are modulated at high speed and the infrared light communication in which the infrared light emitting element portion 335 is modulated at high speed, and use them. For example, when illumination is required and communication is also required, the red light-emitting element portion 332, the green light-emitting element portion 333, and the blue light-emitting element portion 334 are modulated at high speed while emitting light, and information is transmitted. Thus, the optical power required for illumination can be used for communication, and high-speed and high-quality communication can be performed. When the illumination is not necessary but the communication is necessary, the infrared light emitting element portion 335 is modulated and driven to emit infrared light, thereby performing communication. In this case, since infrared light is not visually recognized, communication can be performed in a light-off state. In addition, in general, no one is present at the time of lighting-off, and the influence of eye safety and the like on the human body can be reduced.
Of course, the infrared light emitting element portion 335 may be modulated and driven even during illumination, and communication using infrared light may be performed. In this case, the receiving side may often receive only infrared light, and the configuration can be simplified because the solution is not compatible with a plurality of wavelengths.
Alternatively, the red light emitting element portion 332, the green light emitting element portion 333, and the blue light emitting element portion 334 may be modulation-driven during illumination, and the infrared light emitting element portion 335 may also be modulation-driven, so that communication may be performed by infrared light together with illumination light. In this case, since all the power can be used, high-speed and high-quality communication can be performed as compared with the above-described embodiments.
In the configuration shown in fig. 20, the red light emitting element section 332, the green light emitting element section 333, the blue light emitting element section 334, and the infrared light emitting element section 335 are driven independently of each other, and therefore, if the wavelengths are separated, a plurality of pieces of information can be transmitted at the same time.
Fig. 22 is a schematic view showing another example of the illumination device according to the present invention 3 which is suitably used for the illumination light communication device according to the present invention 3. Fig. 23 is an explanatory view of an application example of the illumination light communication device according to the invention 3 of the present application to another example of the illumination element according to the invention 3 of the present application. In the drawings, the same portions as those in fig. 25 are denoted by the same reference numerals, and redundant description thereof will be omitted. Reference numeral 344 denotes an infrared light emitting element portion. In the example shown in fig. 22, an infrared light emitting element portion 344 is provided in the LED element 341 having the configuration shown in fig. 25 (B).
When such an illumination element is applied to an illumination light communication device, as shown in fig. 23, the wiring of the light emitting element portion 342 is connected to the power distributor 315 for power supply during illumination and for power supply after modulation during illumination light communication. The infrared light emitting element portion 335 may be connected to the light modulation portion 311 via the switch 314, and may be modulated and driven by the light modulation portion 311 when the switch 314 is turned off. The common electrode may be grounded together with the optical modulation unit 311, the power divider 315, and the like.
In normal illumination, blue light or ultraviolet light emitted from the light-emitting element portion 342 is irradiated to the fluorescent agent 343 to emit white light. At this time, by modulating and driving the light emitting element portion 342 at high speed, the illumination light can be used for communication. Further, by modulating and driving the infrared light emitting element portion 344, wireless communication by infrared light is possible although it is not visually visible.
As in the example shown in fig. 20, for example, when lighting is necessary and communication is also necessary, the light-emitting element portion 342 is modulated and driven to transmit information. Thus, the optical power required for illumination can be used for communication, and high-speed and high-quality communication can be performed. When the communication is required without illumination, the infrared light emitting element portion 344 is modulated and driven to emit infrared light, thereby performing communication. In this case, since infrared light is not visually recognized, communication can be performed in a light-off state. In addition, in general, no one is present at the time of lighting-off, and the influence of eye safety and the like on the human body can be reduced.
Of course, similarly to the example shown in fig. 20, the infrared light emitting element portion 344 may be modulation-driven at the time of illumination to perform communication using infrared light, or both the light emitting element portion 342 and the infrared light emitting element portion 344 may be modulation-driven. In the configuration shown in fig. 22, the light emitting element portion 342 and the infrared light emitting element portion 344 can be driven separately to transmit different data in parallel, but different data cannot be transmitted individually for each of the red, green, and blue wavelengths of the bright light.
Fig. 24 is a block diagram showing embodiment 2 of the illumination light communication device according to claim 3 of the present application. The symbols in the figure are the same as those in fig. 18. In embodiment 1 described above, when communication is performed in a state where the illumination is turned off, the communication is performed by the communication unit 317 separately provided. In embodiment 2, an example is shown in which the communication unit 317 is not provided and the illumination unit 316 performs communication even when the lighting is turned off.
In this example, the switch 312 is used to switch lighting on and off of illumination, and the switch 313 is used to switch whether or not to perform communication.
The power distributor 315 drives the illumination unit 316 in accordance with the on/off of the switch 312 and the switch 313, and performs modulation control in accordance with information to be transmitted while supplying sufficient power for illumination to the illumination unit 316 when lighting up, and performs modulation control in accordance with information to be transmitted when lighting down, so that the illumination unit 316 blinks to an extent necessary for only communication when communication is performed.
For example, when the switch 312 and the switch 313 are turned off, the illumination section 316 is modulated in an illumination state to realize illumination light communication. When the switch 312 is opened and the switch 313 is closed, the illumination section 316 is driven by the modulation signal of the optical modulation section 311, and the illumination section 316 is caused to emit light for a very short time in accordance with information to be transmitted, thereby performing communication. If the light is emitted for a very short time, the light is not visually perceived. For this reason, even if the light is actually emitted, it is recognized as being turned off to the eyes of people, and therefore communication can be performed when the light is turned off. When the switch 312 is turned off and the switch 313 is turned on, normal lighting is performed, and when both the switches 312 and 313 are turned on, the lighting is turned off and communication is not performed.
In this way, by controlling the illumination section 316 not to be continuously turned on but to emit light for a very short time in accordance with the information when the lighting is turned off, communication by visible light can be performed by the illumination section 316 in a state where the lighting is turned off to the eyes of a person.
As described above, in addition to communication using light emission for a very short time, communication can be performed by causing the illumination unit 316 to emit light with a weak intensity to the extent that communication can be performed. In this case, although the lamp is not completely turned off, for example, a light amount of a degree of protecting the lamp is also considered in many cases when the light amount is allowed even at the time of turning off the lamp.
Thus, according to the invention of the present application 3, it is possible to provide an illumination light communication device capable of performing communication even when the lighting is turned off, and to provide an illumination device suitably used for such an illumination light communication device.
In the case of an illumination device, the illumination device may be used frequently for 24 hours, and depending on the case, the lighting may be turned off when the illumination device is not used, when sunlight is present around the illumination device, when a projector is used, or the like. In such a case, if information transmission is performed only with illumination light, there is a problem in that the illumination light must be turned on even when information flows. In the invention 3 of the present application, communication can be performed even when the lighting is turned off by using infrared light communication or communication using a short time or a weak light intensity when the lighting is turned off.
In the case of using infrared light communication, by providing a light-emitting element in which a light-emitting element for illumination and a light-emitting element for infrared light are integrated into one light-emitting element, communication using infrared light can be performed when the light is turned off, as described above. Further, the light can be emitted by an element that integrates light from visible light to infrared light, and the device configuration can be miniaturized. That is, instead of a system in which illumination is performed and infrared communication is performed separately, a new compact system using an integrated illumination element can be constructed. If the viewpoint is changed, it is known from the past that wireless information transmission using infrared light is used, but a system is constructed regardless of lighting. That is, a transceiver is provided on a ceiling or the like, separately from the lighting. Therefore, it is difficult to install the infrared communication device over a wide range on a ceiling, and there are many cases where the use is hindered by the influence of shadows and the like, but the infrared communication system and the illumination system can be easily integrated by using the illumination element according to the invention of claim 3 of the present application. Since the illumination is installed in a wide range on a ceiling or the like, the illumination can be easily installed in a wide range even in information transmission, and the influence of shadows is reduced, so that wireless communication by infrared light can be stably utilized.
< invention 4 >
First, the invention of the present application No. 4 will be explained. In the above-described 1 st to 3 rd inventions, examples of performing communication using illumination light directly emitted from a lighting fixture are shown. The 4 th invention of the present application shows an example of a configuration in which illumination light modulated in accordance with information is made to reach a place where illumination and communication are performed using an optical fiber.
Fig. 32 is an explanatory diagram of an example of a conventional illumination device using an optical fiber. In the figure, 401 is a light source, and 402 is an optical fiber. As shown in fig. 32, a conventional lighting fixture using an optical fiber 402 receives light emitted from a light source 401 such as a halogen lamp, LED, or laser from one end of the optical fiber 402 and emits the light into a space from the other end. This emitted light is used as illumination.
In this method, light is emitted from a point light source such as one end of the optical fiber 402, and light having a good straight-line propagation property is emitted, so that a large amount of light is emitted at a narrow angle of view. For this reason, the end of the optical fiber 402 is rather dazzled in the case of being viewed straight with the eyes. In addition, there is a disadvantage that a wide range of illumination is not possible. Therefore, a treatment of diffusing light emitted from the end portion of the optical fiber 402 by providing a diffusion plate at the emission end of the optical fiber 402, emitting light over a somewhat wide range, and reducing glare is also performed.
On the other hand, with the progress of high-speed communication technology, indoor wireless communication technology using light has been utilized. In particular, LANs using infrared rays are not limited to offices and the like, and are becoming widespread in homes and the like. However, in order to use the infrared LAN, a transceiver serving as an access point needs to be specially provided on the ceiling. In addition, if there is an obstacle between the access point and the terminal, transmission and reception are generally not possible. Further, since power needs to be suppressed due to the influence on the human body such as eye safety, there is a problem that high-speed and high-quality communication cannot be performed.
As a communication system for solving such problems, a communication system using illumination light is considered, and the invention of the present application 4 is described with respect to a configuration in which illumination and communication are performed using an optical fiber.
Fig. 26 is a conceptual diagram illustrating embodiment 1 of invention 4 of the present application. In the figure, 411 denotes a light source control unit, 412 denotes a light source, 413 denotes an optical fiber, 414 denotes a light scattering body, 415 denotes a reflection plate, 421 denotes a receiver, 422 denotes a light receiving unit, and 423 denotes a demodulation unit. The light source 412 emits light for illumination, and for example, an element having high-speed response characteristics such as an LED or a laser diode is used.
The light source control section 411 controls on/off or the amount of light of the light source 412 according to information to be transmitted. Thereby causing modulated light to be emitted from the light source 412.
The optical fiber 413 conducts light from the light source 412 from one end to the other. Both glass fiber and Plastic Optical Fiber (POF) can be used as the type of the optical fiber 413. When comparing the two, the POF is lighter and generally can have a larger fiber diameter, so that the energy density of light per unit cross-sectional area of the POF is lower than that of the glass fiber. Thus, higher power optical energy can be transmitted. In addition, POF is easier to connect and has flexibility compared to glass fiber.
The light scattering body 414 is provided at an end of the optical fiber 413, and scatters and emits light conducted to the optical fiber 413. As the light scattering body 414, a high-luminance light scattering/condensing light guide can be used. The high-brightness light scattering polymerization light guide can be formed of, for example, a high-brightness light scattering light guide (HSOT) polymer in which a nonuniform structure of a precise level is formed in a photonic polymer, and can be used as a high-efficiency visible light scattering body as a lighting fixture. When the POF is used as the optical fiber 413, the light scattering body 414 and the optical fiber 413 are made of plastic, and therefore, they can be integrated with each other. For example, the two components may be manufactured separately and integrated, or may be manufactured integrally by adjusting additives, manufacturing conditions, and the like during manufacturing. The light scattering body 414 has an arbitrary shape, for example, a hemispherical shape in fig. 26, and ends of the optical fibers 413 are connected to the center thereof.
The reflecting plate 415 has a mirror surface on a surface facing the light scattering body 414, and returns the scattered light from the upper portion of the light scattering body 414 to the light scattering body 414 again to increase the scattered light from the lower portion of the light scattering body 414. The reflecting plate 415 may be provided by another member, or may be formed by applying a reflecting material to a surface to be reflected, or by vapor deposition. In this example, a case is assumed where a hemispherical light scattering body 414 as shown in fig. 26 is used to illuminate from, for example, a ceiling of a room. In this case, since the flat surface portion of the hemisphere is the ceiling side, and there is no need to radiate scattered light from this surface, the reflection plate 415 is provided in the flat surface portion of the light scattering body 414 to improve the illumination efficiency. However, the reflecting plate 415 may not be provided when there is no need to improve the form of illumination or the luminous efficiency of illumination.
The receiver 421 receives the modulated scattered light emitted from the light scattering body 414 through the optical fiber 413 as described above, and receives the transmitted information. The configuration for this includes a light receiving unit 422, a demodulation unit 423, and the like. The light receiving unit 422 receives the modulated scattered light emitted from the light scattering body 414 through the optical fiber 413, converts the received light into an electrical signal, and sends the electrical signal to the demodulating unit 423. The demodulation unit 423 demodulates an electric signal corresponding to the amount of light received by the light receiving unit 422 to extract original information. Thus, the transmitted information can be received.
An example of the operation in embodiment 1 of the 4 th invention of the present application will be described. In the invention of claim 4, the lighting device can be used as it is without transmitting information. That is, light emitted from the light source 412 is incident on the optical fiber 413, and is incident on the light scattering body 414 after the optical fiber 413 is conducted. The light scattering member 414 scatters light incident from the optical fiber 413 to emit scattered light. The light emitted from the hemispherical upper plane is reflected by the reflection plate 415, and then enters the light scattering member 414 again to be scattered and emitted. The radiated light scattered and radiated by the light scattering body 414 in this way may be used as the illumination light.
In the case of using the optical fiber as an illumination device, a light scattering body 414 is provided at the output end of the optical fiber 413, and the light passing through the optical fiber 413 is emitted as scattered light. Therefore, the luminance per unit area is lower than that of a method of directly irradiating from the end of the optical fiber 413. Thus, the eyes do not feel dazzled even when the user looks directly at the glasses. In addition, a wide range can be illuminated by the light scattering member 414.
Further, when the light scattering body 414 is integrated with the optical fiber 413, it is only necessary to provide the light scattering body 414 indoors, and it is not necessary to provide a large-sized instrument as in the conventional lighting instrument. Since the light source 412 is present everywhere and the light is transmitted only by the optical fiber 413, it is not necessary to provide a light source indoors as in the conventional lighting apparatus. Therefore, for example, when the light source is used in a place where an electrical short circuit or the like is a problem, the light source 412 may be installed in another room, and the optical fiber 413 may be laid on the place and used as illumination. Thus, it is possible to safely perform illumination without causing problems such as leakage or short-circuiting.
When transmitting information, the light source control unit 411 is given the information to be transmitted. The light source control section 411 controls the on/off or the amount of light of the light source 412 based on the received information to be transmitted, and emits light modulated in accordance with the information to be transmitted from the light source 412. Similarly to the case of the above-described illumination, modulated light emitted from the light source 412 is incident on the optical fiber 413, and is incident on the light scattering member 414 after the optical fiber 413 is conducted. The light scattering body 414 scatters modulated light incident from the optical fiber 413, and emits the scattered light. Even if scattering occurs at the light scattering member 414, the frequency at the time of modulation is lower than the frequency of light, and this will not be affected. The modulated scattered light is emitted from the light scattering member 414.
Further, since the light source 412 uses an element having a high-speed response characteristic as described above, high-speed turning on/off or light amount control by the light source control unit 411 is possible, and the modulated scattered light emitted from the light scattering body 414 is also turned on/off or light amount is varied at high speed. However, even when the light is turned on or off or the light amount varies, the light is turned on or off or the light amount varies at a high speed, and the light is not perceived by human eyes, and the light is seen to be emitted at a substantially constant light amount. Therefore, the scattered light emitted from the light scattering body 414 can be used as illumination light as it is even if it is modulated.
When receiving information, the modulated scattered light emitted from the light scatterer 414 may be received by the light receiving unit 422 of the receiver 421. The light received by the light receiving unit 422 is converted into an electrical signal and transmitted to the demodulation unit 423. Then, the information can be acquired by performing demodulation in the demodulation section 423.
In this way, information can be transmitted while lighting is performed. In conventional communication using an optical fiber, it is necessary to pull the optical fiber up to a receiver, and it is difficult to move the receiver. However, in the present invention of claim 4, information can be received at any place as long as the place can receive illumination light. In addition, the receiver can be mobile since no direct connection to the fiber is required. For example, the receiver 421 can be incorporated into a portable terminal and used. In addition, in the case of the conventional infrared communication, wireless communication, or the like, a dedicated transmitter needs to be installed separately from the lighting fixture. However, in the invention of claim 4, the light scattering body 414 is generally provided as a lighting fixture installed indoors, and communication with lighting can be performed by laying the optical fiber 413 instead of the electric wire.
In addition, since the light scattering body 414 emits scattered light, the illumination range can be widened, and therefore the communicable range can also be widened. Further, high power of several watts to several tens of watts is required for illumination, and the power can be used for communication, so that high-speed and high-quality communication can be performed.
Fig. 27 is a conceptual diagram of a 1 st modification example of the 1 st embodiment of the 4 th invention of the present application. The same reference numerals as in fig. 26 are used in the drawings, and redundant description thereof will be omitted. In the above configuration, communication can be performed as long as the receiver 421 can receive the illumination light, and therefore, the shape of the light scattering body 414 and the like are arbitrary, and various shapes can be used. In the modification 1, an example using a flat plate-shaped light scattering body 414 is shown as an example. The configuration and operation are the same as those described above except that the light scattering body 414 is a flat plate.
By using such a flat plate-shaped light scattering body 414, light entering the light scattering body 414 from the optical fiber 413 is scattered in the horizontal direction, and light scattered in the vertical direction is radiated from the plane. The scattered light emitted from the plane is used as illumination light, and thus the two-dimensional illumination light source can be used. This makes it possible to realize a very thin illumination device having a thickness of the light scattering body 414.
In the case where there is a surface on which the radiation of scattered light is not necessary, a reflection surface corresponding to the reflection plate 415 or the reflection plate 415 shown in fig. 26 may be formed on the surface. In the example shown in fig. 27, a reflecting plate 415 is provided on the upper surface of the flat light scattering body 414. By the reflection plate 415, the scattered light emitted from the upper surface of the light scattering body 414 can be returned to the light scattering body 414 again, and the illumination efficiency can be improved.
Further, the light passing through the optical fiber 413 has a linear propagation property, and may not be sufficiently scattered by only 1 light scattering body 414. In this case, it is preferable to use a plurality of light scattering bodies 414 in a superposed manner. This increases the scattering angle, and allows the scattered light to be emitted more uniformly over a wider angle range. Further, a reflecting plate may be provided on a surface of the light scattering body 414 facing the connection surface of the optical fiber 413, and light propagating straight may be reflected and redirected to be sufficiently scattered. Or sufficient scattering can be obtained by entering light from multiple directions of the diffuser 414 by means of multiple optical fibers.
Fig. 28 is a conceptual diagram illustrating a 2 nd modification example of embodiment 1 of the 4 th invention of the present application. The same reference numerals as in fig. 26 are used in the drawings, and redundant description thereof will be omitted. 416 is a phosphor. In this modification 2, an ultraviolet or blue LED or a laser diode is used as the light source 412. Further, a phosphor 416 is mixed into the light scattering member 414 in advance.
Ultraviolet or blue light emitted from the light source 412 is incident on the light diffuser 414 through the optical fiber 413. Then, the fluorescent material 416 in the light scattering body 414 is excited by the incident ultraviolet or blue light, similarly to a fluorescent lamp, to emit white light. The white light is emitted from the light scattering member 414. The light emitted from the light scattering body 414 can be used as illumination light to illuminate. Further, by turning on/off or controlling the light amount of the light source 412 in accordance with information to be transmitted, if modulated ultraviolet light or blue light is emitted from the light source 412, modulated white light is emitted from the light scattering body 414, so that information can be transmitted by receiving light by the light receiving section 422 of the receiver 421.
The light scattering member 414 in this case is not limited to the hemispherical shape shown in fig. 28, and may have various shapes such as a flat plate shape shown in fig. 27.
Fig. 29 is a conceptual diagram illustrating embodiment 2 of invention 4 of the present application. The same reference numerals as in fig. 26 are used in the drawings, and redundant description thereof will be omitted. In embodiment 2, an example is shown in which a plurality of optical fibers 413 are connected to one light scattering body 414, and light of different wavelengths is conducted to the respective optical fibers 413. In the example shown in fig. 29, red, green, and blue light sources are used as the light sources 412, and light of the color emitted from each light source 412 is incident on each of the 3 optical fibers 413.
The red, green, and blue light incident on the respective optical fibers 413 is incident on the light scattering member 414 through the respective optical fibers 413. The light of each color incident on the light scattering body 414 is mixed by being scattered by the light scattering body 414, and is emitted as white light. Therefore, when the light emitted from the light scattering body 414 is used as illumination light, it can be used as a white light source. Of course, in addition to being used as a white light source, it is also possible to produce illumination light of any color by adjusting the intensity of light of each color.
In the communication, it is also possible to control the driving of only a part of the plurality of light sources 412 in addition to the simultaneous control of the driving of the plurality of light sources. The example shown in fig. 29 shows an example in which only the LED or laser diode that emits red light is driven and controlled, and the other LEDs or laser diodes of green and blue are not driven and controlled. If this is done, only the red light is modulated, and the other colors of light are not modulated. Such a configuration is effective, for example, when the sensitivity of the light receiving unit 422 of the receiver 421 has a peak for red or infrared light.
When the light of a part of the colors is modulated in this way, it is desirable that the modulated light component be received and demodulated in the receiver 421. For example, in the case of modulating red light as in the example shown in fig. 29, if a filter for transmitting red light is provided, or if a light receiving unit 422 having a high light receiving sensitivity for red light is used, or if red light is selectively received by various known methods such as splitting red light by using a prism, and then demodulated by the demodulating unit 423, information can be received more reliably.
The light sent to the plurality of optical fibers 413 is arbitrary, and is not limited to the red, green, and blue light as described above, and the intensity of the light can be freely changed. For example, the light quantity may be increased by making the light all of the same color. In the case of using the red, green, and blue light sources 412 as described above, it is also possible to make 3-color light incident on 1 optical fiber 413. The color of light modulated when transmitting information is not limited to red, and light of 1 color or more may be modulated.
In the configuration shown in fig. 29, it is also possible to individually drive and control the light sources 412 for transmitting a plurality of pieces of information in accordance with different pieces of information. That is, information 1 may be transmitted by red light, information 2 may be transmitted by green light, and information 3 may be transmitted by blue light. In this case, if the color of light to be received is selected on the receiver 421 side, information transmitted by the light of the selected color can be received.
Further, for example, in addition to the one or more optical fibers 413 for transmitting the light for illumination, it is also possible to provide an optical fiber for transmitting information, and to control the light source corresponding to the optical fiber to transmit information. In this case, information can be transmitted without changing the color of the illumination light by using, for example, a white light source. In addition, transmission of information by infrared rays can also be performed by using, for example, infrared light.
Fig. 30 is a schematic configuration diagram showing a modification of embodiment 2 of the invention 4 of the present application. When only a part of the colors of light are modulated, as shown in fig. 30, for example, the light source 412 driven and controlled by the drive control unit 411 may be configured to supply modulated light to the light scattering member 414 through the optical fiber 413, and the light source 412 emitting another color may be configured to directly emit light to the light scattering member 414. In this case, light of the color to be incident may be mixed into the light scattering body 414 and synthesized, and may be used as illumination light. At the same time, the light of the specific color is modulated, and the light component can be demodulated by the light receiving demodulation unit 423 of the light receiving unit 422 of the receiver 421 to receive information. Although fig. 30 shows an example of modulating red light, the present invention is not limited to this, and blue and green light may be modulated, or any 2 of 3 colors may be modulated.
Fig. 31 is an explanatory diagram of an application example of the invention of the present application 4. In this example, an example of distributing information in a plurality of rooms is shown. As described above, the present invention according to claim 4 can also be used as a lighting fixture. Therefore, an example is shown in which the light scattering body 414 is provided on the ceiling in the room. When communication is performed by illumination light, the communication quality is degraded if a shadow is generated. When the light scattering body 414 is provided on the ceiling in this way, shadows are less likely to appear due to people, objects, or the like, and therefore the problem of shadows can be avoided as much as possible.
Further, an example in which a plurality of light scattering bodies 414 are provided in the chamber a is shown. By providing a plurality of light scattering bodies 414 in this way, the influence of shadows can be further reduced. When the plurality of light scattering bodies 414 are provided in this manner, modulated light can be transmitted from the same light source to the plurality of light scattering bodies 414 through the optical fiber 413. Therefore, it is not necessary to provide the light source control unit 411 or the light source to the illumination device one by one, and the installation cost of the transmitter can be significantly reduced. Of course, different information may be transmitted from the plurality of light scattering bodies 414, and in this case, the information to be received can be selected by selecting the illumination light to be received on the receiver 421 side.
Further, a light scattering body 414 is also provided in the B chamber. At this time, the modulated light can be sent to the B chamber from the same light source as the a chamber. Thus, the same information can be distributed even if the rooms are different. In this case, the light source control units 411 can be shared even for different rooms, and the light sources 412 can also be shared.
In the above-described embodiments 1 and 2, the transmission of one-way information is explained. However, since the optical fiber 413 conducts light in both directions, bidirectional communication is also possible. That is, light emitted from a light source existing outside the light scattering body 414 is emitted from the light scattering body 414 through the optical fiber 413 from the end of the light source 412. With this, the light source existing outside the light scattering body 414 is driven and controlled to emit modulated light. The modulated light is emitted from the end on the light source 412 side through the optical fiber 413. A light separation device such as a half mirror is provided between the light source 412 and the end of the optical fiber 413, and the transmitted information can be received by demodulating the light emitted from the end of the optical fiber 413 on the light source 412 side by separating and receiving the light. Thereby, bidirectional communication is possible. The amount of light entering the optical fiber 413 through the light scattering body 414 is very weak due to scattering by the light scattering body 414, but improvement in the light receiving sensitivity and improvement in the signal recognition technology can be sufficiently achieved.
As described above, according to the invention of the present application 4, if the optical fiber and the light scattering body are provided, communication can be performed by the illumination light at the same time, and it is not necessary to provide the lighting fixture and the communication device separately on the ceiling or the like as in the conventional case. Further, since communication is performed using illumination light, communication can be performed with high power. Therefore, high-speed and high-quality communication can be performed. Further, while the power is high, a place where the illumination is normally arranged to be shaded is as little as possible, and a shadow such as a problem with an infrared LAN, that is, a phenomenon in which communication is interrupted by an obstacle can be greatly reduced. Further, although the light emitted from the light source is emitted from the light scattering body through the optical fiber, since only the light is used without using an electric circuit therebetween, the system becomes simple, and problems such as electric leakage and short circuit do not occur.
< invention 5 >
Next, the invention of the present application 5 will be explained. The present invention according to claim 5 is directed to a configuration in which information is transmitted between the lighting fixtures by light.
Lighting fixtures are widely installed on a ceiling or the like, or light is irradiated from a high position by constructing an electric pole so that shadows do not appear in a certain area. The use of the illumination light for communication has an advantage that high-quality communication can be performed because it does not cause shading and a large illumination power can be used.
However, since the lighting device is installed at a high position such as a ceiling as described above, there is a problem that it is difficult to construct the lighting device. For example, when communication is performed by illumination light as described above, it is necessary to transmit information transmitted by communication to the lighting fixture. As a method of transmitting information to the lighting apparatus, for example, a method of laying a cable or an optical fiber for a network is considered. However, since new construction for laying a cable or an optical fiber is required, communication by illumination light cannot be easily performed, and a high cost is required.
As a method for eliminating the need for laying a new cable or optical fiber, for example, as in the invention of the present application 1, a method for transmitting a signal to a lighting fixture by superimposing the signal on a power line for lighting is also conceivable. However, in the case of transmitting information by superimposing a signal on a power line, radio wave radiation or the like is often caused when the frequency of the signal is high, and wireless communication may be interfered with. In addition, there is a problem that the signal is easily affected by motor noise, inverter noise, or the like.
As described above, there has been no optimum device for transmitting information to a lighting apparatus for performing illumination light communication, and this has been an obstacle for performing illumination light communication. The present invention according to claim 5 provides an apparatus that is optimal for transmitting information to each lighting fixture.
Fig. 33 is a conceptual diagram showing the illumination light communication system of the invention 5 in embodiment 1. In the figure, 501 denotes an optical communication device, 502 denotes a lighting fixture, 503 denotes a terminal device, 511, 522, and 531 denote optical transmission/reception units, 512 denotes a communication cable, 521 denotes a light emitting element, and 523 denotes a light receiving element. Fig. 33 shows an example in which an illumination light communication system is realized by using a lighting fixture provided for indoor illumination.
An optical communication device 501 for transmitting information for transmission by illumination light communication from a lighting fixture 502 to the lighting fixture 502 is installed indoors. The optical communication device 501 is connected to a network, and transmits and receives information through the network. The network is a wired network installed in offices, schools, factories, homes, and the like, is composed of optical fibers, coaxial cables, twisted wires, and the like, and is often connected to an external telephone network, the internet, and the like. As shown in fig. 33, the terminals of such a network are often installed on a wall or the like, and in such a case, the wall surface terminals and the optical communication device 501 are electrically connected by the communication cable 512.
The optical communication device 501 performs communication through a network as described above, and performs communication using light in a space between the light transmitting/receiving unit 511 and the lighting fixture 502. In the invention of claim 5, communication is performed by using light, but since the light passes through a space during communication, it is not necessary to lay an optical fiber or the like. Of course, the communication cable 512 need not be routed to the respective lighting fixture 502. Since the lighting fixture 502 is installed at a high position such as a ceiling, the optical communication device 501 is preferably installed at a low position where the lighting fixture 502 performing communication does not become a shadow.
The light transmitting/receiving unit 511 is provided with a light emitting element and a light receiving element, and the light emitting element is driven to emit modulated light by modulation in accordance with information, thereby transmitting the information to the lighting fixture 502. In this example, it is desirable that light emitted by the light emitting element be received by a plurality of lighting fixtures 502. For this reason, the directivity is preferably not so sharp. Alternatively, the light emitted from each lighting fixture 502 with sharp directivity that can be specified by the lighting fixture 502 may be irradiated to the lighting fixture 502.
The light receiving element receives light emitted from the light transmitting/receiving unit 522 of the lighting fixture 502 to receive information transmitted from the lighting fixture 502. Further, since the illumination light emitted from the lighting fixture 502 is received, it is necessary to separate and acquire information obtained from the light emitted from the light transmitting/receiving unit 522 of the lighting fixture 502. The light receiving element may not be provided when information from the lighting fixture 502 is not received.
With this configuration, the optical communication device 501 functions as a gateway for converting communication using the wired communication cable 512 and communication using light. In addition, since communication is performed with respect to the plurality of lighting fixtures 502, the function as a base station for wireless (optical) communication is also completed. The light used for communication in the optical transceiver 511 is not limited to visible light, and may be infrared light.
The lighting fixture 502 is the lighting device according to claim 5 of the present application, and is installed on, for example, a ceiling or the like to illuminate a room by light emission of the light emitting element 521. The lighting fixture 502 is provided with a light transmitting/receiving unit 522 including a light emitting element and a light receiving element, and in this example, communicates with the optical communication device 501 by light in a space. The light receiving element is preferably provided with a lens system or the like, for example, and can receive light from the light transmitting/receiving unit 511 of the optical communication device 501 with a pinpoint (pinpoint). Of course, it is preferable to appropriately change the direction such as the incident direction of light. When information is transmitted from the lighting fixture 502 to the optical communication device 501, the light emitting element is preferably provided so that the light can be transmitted to the light transmitting/receiving unit 511 of the optical communication device 501 by the needle tip. For example, when the optical communication device is configured by ld (laser diode), etc., the straight-line propagation property is good, and the visibility of the optical communication device 501 can be improved by coherent light. The optical transceiver 522 can perform bidirectional communication between the lighting fixture 502 and the optical communication device 501.
A control unit, not shown, is provided inside the lighting fixture 502, and the information received and demodulated by the light transmitting/receiving unit 522 is transmitted to the control unit. The control unit controls the driving of the light emitting element 521 in accordance with the received information, and emits the illumination light modulated in accordance with the information. Thereby, information is transmitted from the lighting fixture 502 using the illumination light to the terminal device 503.
In the example shown in fig. 33, the light emitting element 521 is indicated by a circle, and the light receiving element 523 indicated by ● is disposed in the middle. The light-emitting element 521 illuminates as described above, but emits modulated light in accordance with information, and thus has a high response characteristic. For example, a semiconductor light emitting element such as an LED or an LD is preferable.
The light receiving element 523 is an element for receiving light from the terminal device 503. The modulated light emitted from the terminal device 503 can be received and demodulated, and the information transmitted from the terminal device 503 is acquired by the control unit. The acquired information can be transmitted from the optical transmitter/receiver 522 to the optical communication device 501 by light, and the information can be transmitted to the network. By providing the light receiving element 523, bidirectional communication between the lighting fixture 502 and the terminal device 503 can be realized. The light receiving element 523 may receive infrared light instead of visible light, for example. Further, an antenna may be provided instead of the light receiving element 523, and information from the terminal device 503 may be received by radio waves. The system light receiving element 523 is not required to be of a broadcast type.
The terminal device 503 is an information terminal having an optical transceiver 531. The light receiving and transmitting unit 531 receives the illumination light and demodulates the illumination light, thereby acquiring information. Further, by emitting modulated light corresponding to the information by causing the light transmitting/receiving unit 531 to emit light, the information can be transmitted from the terminal device 503 to the lighting fixture 502. The position of the terminal device 503 is arbitrary as long as it is an area illuminated by the illumination fixture 502. Thus, communication can be performed even if the terminal device 503 can move. In addition, since the lighting fixture is generally disposed so as not to cause shading as much as possible and the illumination light is large in power, high-quality and high-speed communication can be performed. Further, the illumination light can be used safely as in the case of infrared rays and the like without affecting human bodies such as eye safety.
In the above-described embodiment 1, information transmitted from a network is transmitted by light in a space by controlling light emission of the optical transmitter/receiver 511 in the optical communication device 501. The light emitted from the light transmitting/receiving unit 511 of the optical communication device 501 is received by the light transmitting/receiving unit 522 of each lighting fixture 502 to receive information. Then, in each lighting fixture 502, the light emitting element 521 is driven in accordance with the information received by the light transmitting/receiving unit 522, and the modulated illumination light is emitted. The modulated illumination light is received and demodulated at the terminal device 503, and information is transmitted to the terminal device 503.
On the other hand, the information of the terminal device 503 is transmitted from the light transmitting/receiving unit 531 of the terminal device 503, received by the light receiving element 523 of the lighting fixture 502 to receive the information, and transmitted to the optical communication device 501 from the light transmitting/receiving unit 522 of the lighting fixture 502 after being modulated according to the information. The optical communication device 501 receives modulated light from the lighting fixture 502 by the optical transceiver 511, converts the light into an electrical signal, and transmits the electrical signal to the network. This enables information from the terminal device 503 to be transmitted to the network.
Fig. 34 is a conceptual diagram showing embodiment 2 of the illumination light communication system according to claim 5 of the present application. Fig. 35 is a plan view showing an example of the same lighting fixture. The same reference numerals as in fig. 33 are used in the drawings, and redundant description thereof will be omitted. 502-1 to 4 are lighting devices, 541 is a lamp socket, and 542 is a rod-like lighting source. In the above-described embodiment 1, an example is shown in which the lighting fixtures 502 receive modulated light from the optical communication device 501, and in the embodiment 2, an example is shown in which information is transferred between the lighting fixtures 502-1 to 4. Further, the lighting fixtures 502-1 to 4 are different from the example shown in fig. 33, and show an example in which the light emitting elements 521 are arranged in the same shape as a straight tube fluorescent lamp which is generally used. The lighting fixtures 502-1 to 4 are the same ones, and will be described as the lighting fixture 502 unless otherwise noted.
In embodiment 2, as shown in fig. 35, the light transmitting/receiving unit 522 is disposed on four sides of the lighting fixture 502, and the light transmitting/receiving unit 522 communicates with the lighting fixture 502. In addition, only the light transmitting/receiving unit 522 of one or more lighting fixtures 502 among the plurality of lighting fixtures 502 communicates with the optical communication device 501, and the lighting fixture 502 that does not directly communicate with the optical communication device 501 transfers information by communicating with another lighting fixture 502.
In the example shown in fig. 34, the light fixture 502-1 directly communicates with the optical communication device 501, the light fixtures 502-2 and 502-3 communicate with the light fixture 502-1, and the light fixture 502-4 communicates with the light fixture 502-2 or 502-3, thereby acquiring information from the optical communication device 501 or transmitting information to the optical communication device 501. For example, the information from the optical communication device 501 is sent to the lighting fixture 502-1, and the information sent to the lighting fixture 502-1 is sent to the lighting fixtures 502-2 and 502-3. Information is then communicated from the light fixture 502-2 or the light fixture 502-3 to the light fixture 502-4. Thus, information from the optical communication device 501 is transmitted to the lighting fixtures 502-1 to 4, and the lighting fixtures 502-1 to 4 transmit the information by the illumination light, respectively, and the information is transmitted to the terminal device 503. On the other hand, when the lighting fixture 502-4 receives the modulated light from the terminal device 503, the information is transmitted to the lighting fixture 502-2 or the lighting fixture 502-3, and further transmitted from the lighting fixture 502-2 or the lighting fixture 502-3 to the lighting fixture 502-1, and the information is transmitted from the lighting fixture 502-1 to the optical communication device 501, and the information is transmitted to the network.
The communication between the respective lighting fixtures 502 is performed by light in space by the light transmitting/receiving unit 522. Thus, communication between the lighting fixtures 502 can be performed from the optical communication device 501 without laying a communication cable, an optical fiber, or the like. In addition, although it is also considered that the attenuation amount of the light quantity for performing communication between the optical communication device 501 and the lighting fixture 502 becomes large in the lighting fixture 502 located far from the optical communication device 501 in embodiment 1, the lighting fixtures 502 are installed at substantially constant intervals in embodiment 2, and therefore, the communication quality does not deteriorate due to the installation position of the lighting fixture 502. Further, since information is transmitted by communication between the lighting fixtures 502, the lighting fixtures 502 that are not in the field of view of the optical communication device 501 can be used for illumination light communication by indirectly communicating with the optical communication device 501 by communicating with other lighting fixtures 502.
In this way, the optical transceiver 522 realizes bidirectional communication between the lighting fixtures 502 and the optical communication device 501. In the case where one-way communication is preferable as in the broadcast type, the light transmitting/receiving unit 522 may be configured by either a light emitting element or a light receiving element, and may be provided so that the light emitting element and the light receiving element face each other between the lighting fixtures 502 that receive and deliver information.
In embodiment 2, an example is shown in fig. 35 in which a rod-like illumination light source 542 having the same shape as a straight tube fluorescent tube is used. The rod-like illumination light source 542 is provided with 1 to several rows of light emitting elements 521, and light receiving elements 523 are dispersed in the middle. When a new lighting fixture is installed, the shape of the lighting source is arbitrary, and the shape of the lighting fixture is determined according to the lighting source, the design, and the like. However, when the conventional illumination fixture is used, it is desirable to use the rod-like illumination light source 542 having the same shape as that of the straight tube fluorescent tube. The rod-shaped illumination light source 542 can be illuminated by supplying power to the rod-shaped illumination light source 542 through the lamp socket 541 in which the rod-shaped illumination light source 542 is installed in a fluorescent room. At this time, a control unit, not shown, is incorporated in advance in the rod-like illumination light source 542. The light transmitting/receiving unit 522 may be disposed around the existing lighting fixture and electrically connected to the rod-shaped lighting source 542. Thus, the lighting apparatus of the invention of the present application 5 can be realized by the existing lighting apparatus. By using an existing lighting fixture, illumination light communication can be realized at lower cost than when the lighting fixture is replaced with a new one.
Of course, the shape of the illumination light source is not limited to a rod-like shape like a straight tube fluorescent tube, and the same applies to an annular shape like a circular tube fluorescent tube (annular shape). Alternatively, the light source may be a bulb-shaped illumination light source as described later.
Fig. 36 is a conceptual diagram showing a 1 st modification example of the 2 nd embodiment of the illumination light communication system according to the 5 th aspect of the present application. The example shown in fig. 34 shows an example in which the lighting fixture is provided on the ceiling surface, and for example, as shown in fig. 36, a case in which the lighting fixture 502 is embedded in the ceiling surface is also shown. In this case, for example, as shown in fig. 36, the light transmitting/receiving unit 522 can be projected to the lower side than the ceiling surface, and thus communication between the lighting fixtures 502 by light can be performed.
Fig. 37 is a conceptual diagram showing a 2 nd modification of the 2 nd embodiment of the illumination light communication system according to the 5 th aspect of the present application. The example shown in fig. 37 also shows an example in which the lighting fixture 502 is installed by being fitted into a ceiling. When the lighting fixture 502 is fitted to the ceiling, the space above the ceiling in which the lighting fixture 502 is fitted is left empty. The light transmitting/receiving unit 522 may be provided in the ceiling to communicate with the lighting fixtures 502 and the optical communication device 501, using the space in the ceiling.
Fig. 38 is a conceptual diagram showing a 3 rd modification of the 2 nd embodiment of the illumination light communication system according to the 5 th aspect of the present application. The example shown in fig. 38 shows an example in which a suspended lamp cover is used as the lighting fixture 502. In the case of the suspended type, a light bulb is often used as a light source, and in the invention of the present application 5, an illumination light source having the same shape as the light bulb is also used. The light transmitting/receiving unit 522 is provided on the back upper portion of the light umbrella of the lighting apparatus 502. Needless to say, the position where the light transmitting/receiving unit 522 is provided is arbitrary as long as it can communicate with another lighting fixture 502, the optical communication device 501, or the like.
For example, in a store or the like, a suspended lighting fixture 502 is often installed at each guest seat, and the configuration shown in fig. 38 is useful in such an application. For example, when internet coffee is opened, broadband communication can be provided by only using light to communicate between the lighting fixtures 502 and the optical communication device 501, and cabling in a store is not necessary.
Fig. 39 and 40 are conceptual views showing embodiment 3 of the illumination light communication system according to claim 5 of the present application. Fig. 41 is an explanatory view of an example of the same illumination light source. In the figure, reference numeral 551 denotes an illumination light source, 552 denotes an adjacent light source-to-light source light transmitting/receiving unit, and 553 denotes an illumination fixture-to-light fixture light transmitting/receiving unit. In the example shown in fig. 35 and the like, even when an existing lighting fixture is used, it is necessary to attach the light transmitting/receiving unit 522 together with the lighting source. In embodiment 3, an example is shown in which the illumination light source is integrally configured with the light transmitting/receiving unit 522.
In the example shown in fig. 41, for example, the illumination light source 551 according to the invention of the present application 5 shows a rod-like shape similar to that of a straight tube fluorescent tube, as in fig. 35. The illumination light source 551 is provided with a light emitting element 521 and a light receiving element 523, and is also provided therein with a control unit, not shown. In addition, when the illumination light sources 551 are arranged such that the adjacent light source light transmission/reception section 552 is provided in the abdomen and a plurality of fluorescent tubes are arranged in parallel, there is a light transmission/reception section for performing communication with the adjacent illumination light sources 551. Further, it is also conceivable to provide 3 or more illumination light sources 551, and it is preferable to provide adjacent light source-to-light transmitting/receiving sections 552 on both sides of the abdomen.
Further, an inter-lighting-fixture light transmitting/receiving unit 553 is provided for communicating with the lighting source 551 or the optical communication device 501 other than the adjacent lighting source 551. The inter-lighting-fixture light transmitting/receiving unit 553 corresponds to various lighting fixtures, and therefore, it is preferable that the length, direction, and the like are adjustably configured. In fig. 41, the lighting fixture light transmitting/receiving units 553 are provided at both ends, respectively, but may be provided only at one of the ends.
The illumination light source 551 is attached to an existing fluorescent tube of a lighting fixture after replacement. In this case, the illumination light source 551 is preferably mounted on the lamp holder holding the fluorescent tube as it is. Thus, the power of the illumination light source 551 can be supplied from the socket of the lighting fixture. Then, the information using the illumination light can be transmitted by adjusting the length or direction of the lighting fixture light transmitting/receiving unit 553.
Fig. 39 shows an example of a configuration applied to embodiment 1 of the present invention 5 shown in fig. 33. In this case, the inter-lighting-fixture light transmitting/receiving unit 553 provided in each of the lighting sources 551 may be directed to the optical communication apparatus 501. In this case, the inter-lighting-fixture light-transmitting/receiving unit 553 is provided in one of the lighting sources 551 in each lighting fixture, and the information may be transmitted to the other lighting source 551 by using the adjacent inter-light-source light-transmitting/receiving unit 552 without providing the inter-lighting-fixture light-transmitting/receiving unit 553.
The example shown in fig. 40 is an example of a configuration applied to embodiment 2 of the present invention 5 shown in fig. 34. In this case, the optical communication device 501 communicates with the lighting fixture inter-light transmitting/receiving unit 553 provided in a certain lighting source 551, and communicates with the other lighting source 551 through the adjacent light source inter-light transmitting/receiving unit 552 or the lighting fixture inter-light transmitting/receiving unit 553. If the communication route is set as at least one stroke, illumination light communication can be performed among all the illumination light sources 551. Of course, a plurality of communication routes may be set in advance.
Fig. 39 and 40 show a case where the illumination light source 551 is attached to a ceiling-embedded lighting fixture, and in this case, it is effective that the lighting fixture-to-lighting fixture light transmitting/receiving portion 553 protrudes downward as shown in the drawing. Similarly, depending on the lighting fixture to which the illumination light source 551 is attached, the surrounding lamp shade may extend to a lower portion than the illumination light source 551. In this case as well, it is effective to make the inter-lighting-fixture light-transmitting/receiving section 553 protrude downward.
Fig. 42 is a conceptual diagram illustrating embodiment 4 of the illumination light communication system according to claim 5 of the present application. Fig. 43 is an explanatory view of an example of the same illumination light source. In embodiment 4, the light emitting element 521 and the light receiving element 523 are used instead of the light transmitting/receiving unit 522 in the illumination light source 551 or the illumination fixture 502. Here, an example is shown in which an illumination light source 551 having a light emitting element 521 and a light receiving element 523 as shown in fig. 43 is used, and the illumination light source 551 is attached to an existing illumination fixture to construct an illumination light communication system. As is clear from comparison with the illumination light source 551 shown in fig. 41, in the example of the illumination light source 551 shown in fig. 43, the adjacent inter-light-source light transmitting/receiving section 552 and the inter-lighting-fixture light transmitting/receiving section 553 are not provided.
The light receiving element 523 receives light (visible light, infrared light, or the like) emitted from the light transmitting/receiving unit 511 of the optical communication device 501, and receives information from the optical communication device 501. The light emission of the light emitting element 521 is modulated in accordance with the received information, and the modulated illumination light is emitted. If the terminal device 503 receives and demodulates the light, the terminal device 503 can receive the information.
When information is transmitted from the terminal device 503, the modulated light emitted from the terminal device 503 is received by the light receiving element 523 of the illumination light source 551 and demodulated, and the information from the terminal device 503 reaches the illumination light source 551. The light emitted from the light emitting element 521 is modulated according to the received information, and the modulated illumination light is emitted. When the optical transceiver 511 of the optical communication device 501 receives the information and demodulates the information, the information from the terminal device 503 reaches the optical communication device 501.
As described above, in embodiment 4, both the optical communication apparatus 501 and the terminal apparatus 503 emit light to the illumination light source 551 or receive illumination light emitted from the illumination light source 551. Compared with the case where the optical communication device 501 and the terminal device 503 perform direct communication by light, the lighting fixture is installed in a place where shadows are hard to appear, such as a ceiling, while using a large amount of illumination light, so that the influence of the shadows can be reduced, and good communication can be achieved. Of course, the communication cable, the optical cable, and the like to the lighting fixture 502 are not required to be laid.
Although the example shown in fig. 42 shows an example using the dedicated illumination light source 551 as shown in fig. 43, for example, even when using a dedicated illumination fixture as shown in fig. 33, the same can be configured without providing the light transmitting/receiving unit 522 in the illumination fixture 502.
Fig. 44 is a conceptual diagram illustrating embodiment 5 of the illumination light communication system according to claim 5 of the present application. In the figure, 561 denotes a street lamp. The street lamp 561 installed on the road is currently mainly a mercury lamp, a sodium vapor lamp, a fluorescent lamp, or the like, but application of a semiconductor light emitting element such as an LED is also considered. When the semiconductor light emitting element is used as the illumination light source of the street lamp 561, various information can be transmitted to a passing vehicle or pedestrian by the illumination light. At this time, it takes a cost to lay communication cables, optical fibers, and the like for transmitting information to be transmitted to the respective street lamps 561.
In the 5 th aspect of the present invention, the light transmitting/receiving unit 522 is provided in the street lamps 561, and information is transmitted and received by light in the space between the street lamps 561, as in the 2 nd embodiment. This allows the street lamps 561 to transmit information, and the illumination light from the street lamps 561 transmits the information. In such a configuration, it is economical to perform only the construction of the street lamps 561, without laying communication cables, optical fibers, and the like.
The street lamps 561 are spaced apart from each other by about 30m in a high-speed road, which is wider than the above-described indoor space, and are within a range in which communication using light can be sufficiently performed. Further, although it is necessary to adjust the direction of the light transmitting/receiving unit 522 so as to be directed to the adjacent street lamp depending on the terrain, the structure of the road, and the like, it is not so difficult as long as the street lamp is spaced at a regular interval. Further, although it is assumed that the fog is generated to block the visual field, this is not a serious problem since the interval is about 30 m.
Here, as an example of an outdoor network, an example in which street lamps installed on a road are communicated with each other by light is shown, but the application example of the invention of the present application 5 is not limited to this. For example, the present invention can be used for various applications such as a guide light of an aircraft and an illumination light of a program venue.
As described above, the present invention 5 has been explained in several embodiments and modifications thereof. In the above description, the information from the optical communication device 501 is transmitted to the lighting fixture 502, the illumination light source 551, the street lamp 561, and the like (referred to as a lighting fixture and the like herein), but it is not necessary that the received information is transmitted by the illumination light as it is in the respective lighting fixtures and the like. For example, an address, an ID, or the like may be added to a header of the transmitted information, and the information may be transmitted by illumination light after selecting the information by a lighting fixture or the like. Further, there may be a lighting fixture or the like that does not transmit information using illumination light but functions as a kind of relay or router.
As described above, according to the invention of the present application 5, since the illumination appliances, the illumination light sources, and the like communicate with each other by light in space, and information is transmitted to the illumination appliances, the illumination light sources, and the like that perform illumination light communication, the illumination light communication system can be constructed at low cost without requiring a communication cable or an optical fiber to be laid. In this case, the lighting apparatus can be constructed by using an existing lighting apparatus, and the cost can be further reduced. In addition, in the communication using light, it is possible to transmit information with high communication quality without causing problems such as limitation of a frequency band, overlapping of radio wave radiation and noise, and the like, unlike the communication using a lamp line.
< invention 6 >
Several inventions will be described below with respect to application examples of communication using such illumination light. The invention of the present application 6 will be explained. The 6 th invention shows an example in which various types of lighting such as home electric appliances and electric appliances are used for communication.
In various electrical devices, semiconductor light Emitting elements such as leds (light Emitting diodes) have been used for display. Fig. 53 and 54 are explanatory views of an example of a mode in which an LED is used for display in an electrical device. Fig. 53(a) shows an example of a television receiver, which is provided with LEDs for displaying on/off of power, distinction between display and standby, distinction of input terminals, and the like. Fig. 53(B) shows an example of an audio device, but in this case, an LED indicating turning on/off of the power supply is also provided. Further, in the example shown in fig. 53(C), LEDs are provided in meters provided in the measuring instruments and the like, and the operating states of the respective meters, the states of the values indicated by the meters, and the like are displayed.
Not only is such simple light emission used to convey display contents to a user, but also semiconductor light emitting elements such as LEDs are used in display devices for displaying characters, pictures, and the like. For example, fig. 54(a) shows an example of a device provided with a liquid crystal panel. In such a liquid crystal panel, an LED is widely used as a backlight. Fig. 54(B) also shows an example of a node personal computer, but in this case, a liquid crystal panel with a backlight is often used as a display device. As the backlight in this case, an LED is also used. In addition, display devices such as an electro-optical sign in which a large number of LEDs are arranged have been developed and used.
Further, in addition to the use of obtaining information to a user by recognizing the light emission as described above, semiconductor light emitting elements such as LEDs are also widely used for decoration. Fig. 54(C) shows an example of the illumination used for a christmas tree. In addition, the present invention is also used for decoration of billboards, interior decorations, and the like in stores. In addition, semiconductor light emitting elements such as LEDs are used in various electric devices.
Semiconductor light emitting elements such as LEDs provided in such electrical devices cause light to be directly seen by people, thereby giving rise to transmission of information and aesthetic feeling. Conventionally, the method has been used only for this purpose, but has not been used for other purposes.
Fig. 45 is a block diagram showing an embodiment of an electric device according to claim 6 of the present application. In the figure, 601 is an electric device, 602 is a receiver, 611 is an LED, 612 is a control unit, 621 is a light receiving unit, 622 is an optical system, and 623 is a demodulation unit. Here, an example using the LED611 is shown as an example of the semiconductor light emitting element. In addition, the same applies to other semiconductor light emitting elements such as laser diodes, EL elements, and plasma display elements.
The LED611 is an LED light source for display conventionally provided in an electric appliance, and is used here to display the state of a device such as a power supply. In addition, the LED611 is constituted by a single element, or by a plurality of elements. Further, there are various element configurations such as having a multicolor light emitting region in a single element.
The control section 612 controls the on/off or the light emission amount of the LED611 in accordance with the information, and modulates the light emission of the LED611 to transmit the information. The LED611 has a property of having a very fast response speed as described above, and can transmit information by controlling on/off or the amount of light emission at a high speed in accordance with the information. Even if the on/off or the light emission amount is controlled at a high speed, such a change in the on/off or the light emission amount is not noticeable, but is seen as if the light is continuously turned on. Accordingly, information can be transmitted while keeping the lighting state of the conventional LED611 unchanged. The modulation method is any modulation method to which various digital or analog modulation methods can be applied.
With this configuration, the LED611 conventionally provided for display in the electric device can be used to transmit information while maintaining the display function. Electrical devices require many functions but require increased functions in a simple design over a limited area. Therefore, by using the LED611 provided in the related art, the function of transmitting information can be added without increasing the size of the apparatus.
The receiver 602 receives the modulated light from the LED611 of the electrical device 601 to receive information. The configuration for this includes a light receiving unit 621 that receives light and converts the light into an electrical signal, and a demodulation unit 623 that demodulates the electrical signal to extract information. The light from the electrical device 601 is received by the light receiving unit 621 and the information is extracted by the demodulation unit 623, thereby realizing the information transmission from the electrical device 601 to the receiver 602.
An optical system 622 such as a lens may be provided in the light receiving section 621. By providing the optical system 622, it is possible to limit the light source of the received light and receive information with the needle tip. For this reason, even in the case where similar electrical devices are arranged, it is possible to receive information from a specific electrical device without being interfered by information transmission from other electrical devices.
Fig. 46 is a schematic view showing a 1 st application example in an embodiment of an electric device according to the 6 th aspect of the present invention. In the figure, reference numeral 631 denotes a television receiver, 632 denotes an LED, 633 denotes an infrared light receiving unit, 641 denotes a remote controller, 642 denotes a light receiving unit, 643 denotes an infrared light transmitting unit, 644 denotes a display unit, 651 denotes a portable terminal, and 652 denotes a camera. Fig. 46 shows an example in which the invention 6 of the present application is applied to a television receiver.
In the television receiver 631, a remote operation using the remote control 641 has been conventionally performed. The communication from the remote controller 641 to the television receiver 631 is typically by infrared rays. In the example shown in fig. 46, as a configuration for this, an infrared light transmitting unit 643 is provided in a remote controller 641, and an infrared light receiving unit 633 is provided on the television receiver 631 side. With this configuration, when the user operates the remote control 641, information corresponding to the operation is transmitted to the television receiver 631 by infrared rays. For example, when a channel is selected by the remote control 641, information on the selected channel is transmitted from the infrared light transmitting unit 643 to the television receiver 631 by infrared rays, and the infrared light receiving unit 633 of the television receiver 631 receives the information and switches the channel to the selected channel. In the general television receiver 631, only one-way communication from the remote controller 641 to the television receiver 631 is performed.
One or more LEDs 632 for displaying on/off of power and whether the display state or the standby state are normally provided on the television receiver 631. In the present invention 6, the LED632 is used as the LED611 shown in fig. 45 to transmit information. That is, the LED632 has functions of turning on/off the power supply and displaying the status, which have been conventionally performed, and also has a function of transmitting information by performing modulation driving according to the information and emitting visible modulated light.
The remote controller 641 is provided with a light receiving unit 642 for receiving the modulated light emitted from the television receiver 631. The information transmitted from the television receiver 631 can be received by receiving visible modulated light emitted from the television receiver 631 by the light receiving unit 642 and internally demodulating the received light.
This enables information transmission from the television receiver 631 to the remote controller 641. The communication between the television receiver 631 and the remote controller 641, which has been conventionally performed as unidirectional communication, is bidirectional communication, and the state of the television receiver 631 can be received on the remote controller 641 side and transmitted to the user. With this, for example, the operation method of the television receiver 631 or the program reservation state is transmitted from the television receiver 631 to the remote controller 641, received on the remote controller 641 side, displayed on the display unit 644, and confirmed. Further, various operations may be performed while the display portion 644 of the remote controller 641 confirms the state of the television receiver 631.
Fig. 46 shows an example of a mobile terminal 651 further provided with a camera 652. The information transmitted by the LED632 of the television receiver 631 may be received by various devices that can receive visible light, instead of a dedicated device such as the remote control 641. In recent years, mobile phones with cameras or PDAs have been actively used, and they can be used as the mobile terminal 651 to receive information transmitted from the television receiver 631. Further, a device originally having an image capturing function, such as a digital camera or a digital video camera, may be provided with a communication function.
Similarly to the remote controller 641 and the mobile terminal 651, for example, the program content received by the television receiver 631 can be transmitted from the television receiver 631, displayed on the display unit of the mobile terminal 651, and reproduced from the speaker. For example, it is possible to display and check a program (a program) different from the television receiver 631, or to display and view a program on the remote controller 641 and the mobile terminal 651 side without displaying a character broadcast or the like on the screen of the television receiver 631.
Since such transmission of information using visible light can be performed in a state where the LED632 is on, communication can be performed in a standby state where viewing is not performed, for example. Further, since the light from the light source can be selectively received when an optical system such as a lens is provided in the light receiving unit 642 of the remote controller 641 or when the camera 652 of the portable terminal 651 is provided, information from a specific television receiver can be selectively received even when a plurality of television receivers are provided in parallel, for example.
Fig. 47 is a schematic diagram showing a modification of the 1 st application example in the embodiment of the electric device according to the 6 th aspect of the present application. In the drawings, the same portions as those in fig. 46 are denoted by the same reference numerals, and redundant description thereof will be omitted. Reference numeral 34 denotes a light receiving portion, and 45 denotes a light emitting portion. In the example shown in fig. 46, the information transmission from the remote controller 641 to the television receiver 631 is performed by infrared rays, but in the modification shown in fig. 47, an example in which the information transmission from the remote controller 641 to the television receiver 631 is also performed by visible rays is shown. Note that the transmission of information by visible light from the television receiver 631 to the remote controller 641 is also the same as in the above example.
In order to realize information transmission by visible light from the remote controller 641 to the television receiver 631, the light emitting unit 45 is provided on the remote controller 641 side and the light receiving unit 34 is provided on the television receiver 631 side. These correspond to the infrared light transmitting unit 643 and the infrared light receiving unit 633 shown in fig. 46.
When information is transmitted from the remote control 641, the light-emitting unit 45 may be caused to emit light in accordance with a signal modulated in accordance with the information. The modulated light is received by the light receiving unit 34 on the television receiver 631 side and demodulated, whereby information transmitted from the remote controller 641 can be received.
An optical system such as a mirror or a lens is preferably provided in the light emitting unit 45 provided in the remote controller 641 so as to converge the light beam of the modulated light emitted from the light emitting unit 45. This allows the modulated light to efficiently reach the television receiver 631. At the same time, since the light used for the communication is visible light, when the converged light flux reaches the television receiver 631, the surface of the television receiver 631 is brightly illuminated as shown in fig. 47, for example, in the same manner as a flashlight or the like. Thereby, an area irradiated by light emitted from the remote controller 641 can be recognized. For example, even when a plurality of television receivers 631 exist, it is possible to reliably identify and confirm a television receiver to which information is to be transmitted, and transmit information.
Since infrared light is not visible to the eyes, a transmission destination of information cannot be specified, and if a plurality of television receivers are present, a setting operation such as changing an ID needs to be performed on the controller side. However, in the invention of claim 6, such setting is not required, and it is only necessary to perform the remote controller operation by confirming with the eyes that the television receiver to be operated is irradiated with light, and it is possible to easily perform the reliable operation.
The remote control 641 is not limited to a television receiver, and may be used in various devices such as a video camera, a DVD, an audio device, an air conditioner, and others, and the above-described application example 1 is similarly applicable to these devices.
The present invention can be applied to any device that displays the power supply state or the device state by a semiconductor light emitting element such as an LED, and an example of application to a measurement device or the like will be described next. Fig. 48 is a schematic view showing a 2 nd application example in an embodiment of the electric device according to the 6 th aspect of the present invention. In the figure, 661 is an instrument, and 662 is an LED display. The mobile terminal 651 is provided with a camera 652 in the same manner as shown in fig. 46.
As shown in fig. 48, various instruments 661 are arranged in an aircraft cabin, a control panel of a factory, and the like. At the same time, the LED display 662 often displays whether or not the device corresponding to the device 661 is operating or the status thereof. This LED display 662 is used as the LED611 shown in fig. 45 to transmit information. That is, the LED display 662 has a function of displaying the operation state of the device and the like, which are conventionally performed, and a function of performing modulation driving according to information, emitting visible modulated light, and transmitting information. For example, various information such as the state of the device in which each instrument 661 is responsible, the value indicated by the instrument 661, and a manual of a measurement device or a control device provided with the instrument 661 can be transmitted.
The modulated light emitted from the LED display 662 provided in the device 661 can be received by the portable terminal 651 provided with the camera 652, for example. In particular, when a plurality of instruments 661 are provided as shown in fig. 48, information from the LED display 662 of a specific instrument 661 can be received by selectively imaging the LED display 662 of the instrument 661 with the camera 652. For example, when the detailed state or manual of the 4 th device 661 from the left is desired to be known, only the LED display 662 of the 4 th device 661 may be photographed. Thus, only the information transmitted from the LED display 662 of the 4 th instrument 661 from the left can be selectively received. At this time, the user can reliably acquire desired information without making an error by capturing the position of the LED display 662 while viewing the image captured by the camera 652.
If such information is communicated by radio waves or the like, the radio waves may not be captured by the needle tip because the radio waves propagate around the needle tip, and the information may be received from another device. Further, it is necessary to transmit the radio wave with different frequencies, times, codes, and the like, and it is necessary to perform troublesome operations and checks such as selecting the radio wave from a specific device on the receiving side. Thus, there are a plurality of devices in a narrow place, and one of them can be directly selected without error, which is an advantage of communication using visible light.
By sequentially performing communication with the device 661 as described above, information from the device 661 is stored in the portable terminal 651. The stored information may be transmitted to the portable terminal 651 or other terminal or host for processing. For example, it can also be applied to check usage in electric or water meters, gas meters, and the like.
Fig. 49 is a schematic diagram showing a modification example of the 2 nd application example in the embodiment of the electric device according to the 6 th invention of the present application. In the figure, 653 denotes a light emitting portion, and 663 denotes a light receiving portion. Similarly to the examples shown in fig. 46 and 47, the apparatus 661 can be provided with the light receiving unit 663 for receiving visible light or infrared light, and the portable terminal 651 can be provided with the light emitting unit 653 for emitting visible light or infrared light, so that the communication from the portable terminal 651 to the apparatus 661 can be performed, and the bidirectional communication can be performed. By enabling bidirectional communication in this way, reliable communication can be performed, for example, by making a request for confirmation of the device 661 or transmission of information from the portable terminal 651 to the device 661, or by returning confirmation of transmission of information to the device 661.
When such a signal exchange is performed between the device 661 and the portable terminal 651, for example, by turning on or off the LED display 662 of the device 661 to be visible to the user or changing the color, a communicable state, or the like can be displayed on the same LED display 662. This enables the user to reliably select the device 661 to be communicated with, without being confused with another device.
As described with reference to fig. 47, the light-emitting unit 653 on the portable terminal 651 side is provided with an optical system, and the light beam is converged, whereby information can be transmitted to the needlepoint of a specific instrument 661, and it is possible to determine to which instrument 661 information is transmitted by the light beam focused on the instrument 661, and visually confirm the information.
As described above, the invention of the present application 6 can be applied not only to household electric appliances but also to industrial equipment such as meters and control boards of factories. In addition, the present invention can be widely applied to various applications such as business equipment, transportation equipment such as automobiles and aircrafts, and the like.
Fig. 50 is a schematic diagram showing a 3 rd application example in an embodiment of the electric device according to the 6 th aspect of the present invention. In the figure, 671 denotes an audio device, 672 denotes a liquid crystal panel, and 673 denotes a backlight LED. In the above application examples 1 and 2, the LED alone is used to display the power supply status, the device status, and the like of the device, but the invention of the present application 6 is not limited thereto. In the application example 3, an example is shown in which a semiconductor light emitting element such as an LED incorporated in a display device is used for communication. The mobile terminal 651 is provided with at least a camera 652 as in fig. 46, 48, and 49.
The audio equipment 671 is shown as a specific example. A liquid crystal panel 672 is provided in the nearest audio device 671 to display various information. An LED is often used as the backlight on the liquid crystal panel 672. This backlight LED673 is used as the LED611 shown in fig. 45 to transmit information. That is, information is displayed on the liquid crystal panel 672, and a user can refer to an image displayed on the liquid crystal panel 672, and by modulating and driving the backlight LED673 in accordance with information to be transmitted, information can be transmitted by using light of the backlight. For example, the portable terminal 651 or the like can receive information by receiving and demodulating light of background light.
As in the above-described application example 1, the modification thereof, or the modification of the application example 2, when bidirectional communication is performed, it is preferable that a light receiving element or a light receiving layer is provided near the backlight LED673 of the liquid crystal panel 672 or on the back surface of the liquid crystal layer of the liquid crystal panel 672 so as to receive visible light or infrared light. In a state where light from the backlight LED673 passes through the liquid crystal layer, light from the outside can also pass through the liquid crystal layer, and thus a configuration in which a light receiving portion is provided in the liquid crystal panel 672 can be adopted. Then, a light emitting element of visible light or infrared light may be provided in the mobile terminal 651, and visible light or infrared light modulated in accordance with information to be transmitted may be emitted, received by a light receiving unit in the liquid crystal panel 672, and demodulated. This enables information transmission from the mobile terminal 651 to the audio device 671, and bidirectional communication is possible.
Of course, if the audio device 671 is a device that can be operated by a remote controller, communication by visible light using the backlight LED673 can be performed similarly also in the case of using a remote controller as in the above-described application example 1. Although the audio equipment 671 is described as a specific example, the present invention is not limited to this, and can be applied to equipment equipped with various display devices using LEDs as light sources. For example, the present invention can be used in a display unit of a home appliance, a liquid crystal display of an inner panel of a wireless device, a node-type personal computer, a liquid crystal display, a liquid crystal television, an automobile, or the like, and all devices using a liquid crystal display device using an LED as a backlight, such as a car navigation system. In the above-described portable terminal and the like, communication may be similarly performed on the display portion using an LED for illumination.
Furthermore, the present invention can be applied to various display devices using semiconductor light-emitting elements other than LEDs as light sources, and can be applied to a display device using visible light similarly even to a display device of another type as long as the device has a very high response characteristic, without being limited to a liquid crystal display device.
Fig. 51 is a schematic diagram showing a 4 th application example in an embodiment of the electric device according to the 6 th invention of the present application. In the figure, 681 is a christmas tree, 682 is a decorative lamp, 683 is an LED, and 684 is a light receiving element. In this 4 th application example, a case where an LED is used for decoration is shown, and a case of a christmas tree 681 is shown as an example thereof. The mobile terminal 651 is provided with at least a camera 652 as in the same manner as shown in fig. 46, 48, 49, and 50.
Various decorations are implemented on christmas tree 681, and a decorative light 682 is used as one of them. The decorative lamp 682 is decorated with light by arranging light sources at appropriate intervals on electric wires and hanging the lamp on a christmas tree 681 or the like to turn on and off the light sources.
In recent years, lamps have been developed that also use LEDs 683 for the decorative lamp 682. This LED683 can be used as the LED611 shown in fig. 45 to perform transmission of information. That is, when the LED683 is lit, visible light modulated by modulation driving in accordance with information can be emitted. The information can be received by receiving the modulated light and demodulating it in, for example, the mobile terminal 651. Thus, for example, when a pedestrian or the like shields the mobile terminal 651 while watching the christmas tree 681, it is possible to receive various information such as messages, images, and sounds transmitted from the christmas tree 681.
Further, since the decorative lamp 682 has a large number of portions where the LEDs 683 are not disposed, a light-receiving element 684 that receives visible light or infrared light can be provided in the portions. Then, the portable terminal 651 may be provided with a light emitting element of visible light or infrared light, emit visible light or infrared light modulated in accordance with information to be transmitted, and receive and demodulate the light by the light receiving element 684. This enables information transmission from the mobile terminal 651 to the christmas tree 681, and bidirectional communication is possible. Of course, the light-receiving element 684 may be disposed on the christmas tree 681 separately from the decorative lamp 682 and together with other decorative components.
Although the example of the decoration lamp for the christmas tree is shown in the 4 th application example, a semiconductor light emitting element such as an LED used for various decorations can be used for communication by visible light in addition to this. For example, a semiconductor light emitting element such as an LED used for clothing with electric decoration, decoration of mountain bike, interior furniture, and the like, electric decoration of store and building, and various decorations, which are used in traveling, can be used for communication of visible light.
Fig. 52 is a schematic view showing a 5 th application example in an embodiment of the electric device according to the 6 th invention of the present application. In the figure, 691 is an electric sign. In recent years, an electro-optical signboard 691 provided with a plurality of light sources has been widely used, and LEDs are often used as the light sources. Further, in some cases, an LED for decoration is disposed in addition to a portion for displaying information in the electric sign 691. These LEDs for displaying information, LEDs for decoration, and the like can be used as the LEDs 611 shown in fig. 45 to transmit information. For example, if a pedestrian or the like blocks the camera-equipped mobile terminal 651 or the like on the electric sign 691, various information such as a message, an image, and a voice transmitted from the electric sign 691 can be received.
Of course, if the light receiving element for receiving visible light or infrared light is provided in the electric sign 691, bidirectional communication can be performed with the portable terminal 651 provided with the light emitting element for visible light or infrared light.
The electric sign 691 is used as a sign at a store, or used for various purposes such as destination display, sort display, and fee display at a train, a bus, and the like, in addition to displaying news and the like at the street. The present invention 6 can be applied to the electric sign used in such various applications. In addition, in the case of an indicator lamp during construction, a guide lamp held by a guide, a marker lamp installed on a road or a road surface, and the like, the semiconductor light emitting element can be used for communication by using various applications of the semiconductor light emitting element so as to perform communication by visible light.
As described above, according to the invention of the present application 6, the semiconductor light emitting element such as an LED used for a display device for transmitting information by making light directly visible to a human or giving an aesthetic feeling can be used for communication by visible light by modulating and driving the semiconductor light emitting element according to information as it functions as a display device. By thus using the original semiconductor light emitting element, communication can be performed without newly providing a transmission device, and the need for increasing the size of the device or changing the design is eliminated.
In addition, in the conventional electric device using the remote controller, the remote controller is mounted with a light receiving device so that information transmitted from the electric device can be received. Information can be received by a portable terminal with a camera or the like, in addition to the remote controller. In this case, if the optical system is provided as a camera or the like and the received light beam can be converged, the light source as the information transmission source can be specified and the information can be received by the needle tip.
Further, if the transmission function of visible light, infrared light, or the like is provided, bidirectional communication can be performed between the electric devices. In addition, when the remote controller has a transmission function by visible light, the area to be transmitted is illuminated by the light beam of the light used for transmission, whereby the device to be transmitted can be reliably identified and specified, and communication of the transmission destination of the information can be easily specified.
< invention 7 >
Next, the invention of the present application 7 will be described as an application example 2. The invention of the present application 7 is directed to an application example of an emergency lamp.
Even in the display, the emergency light is rarely turned off semi-permanently when it is turned on. This is because it is necessary to prepare for accidents such as fires and disasters, and a plurality of emergency lamps are installed in buildings, theaters, movie theaters, hospitals, airports, stations, and other places where there is much interest. Most of the existing emergency lamps use fluorescent lamps as light sources. In the emergency light, it is assumed that external power is cut off in a disaster, and an internal battery is used to display the power in an abnormal state. Fluorescent lamps, which are more power efficient than incandescent bulbs, are used in order to efficiently utilize the limited power. However, further reduction in maintenance cost due to the use of a light source having high power efficiency or the use of a light source having a long life is expected. As described above, although LEDs have excellent power efficiency and long life, their application to emergency lamps is not considered. As described in japanese patent application laid-open No. 9-19084, there is only an example in which an LED is used for a secondary display such as a display during charging, but the LED is not used as a main light source of an emergency light.
In addition, emergency lights are typically provided to only visually indicate where there is an emergency exit or a very stairway. As other information, for example, it is known to provide a guide mechanism using sound as described in japanese patent laid-open No. 8-299475, or to perform radio broadcasting as described in japanese patent laid-open No. 8-67203. However, the sound output consumes much power. Therefore, in addition to visual display of an emergency exit or the like, which is the fundamental meaning of an emergency light, it is necessary to mount a large-capacity battery for such audio output, which is a problem that the price is increased and the size of the equipment is increased.
On the other hand, since high-speed modulation can be performed by utilizing the high-speed response characteristics of LEDs, studies have been made to use LEDs for optical data transmission. Using this, the idea of simultaneously lighting and communication is also known. However, a general lighting fixture is turned off when power supply is stopped in a disaster or the like. Therefore, any use cannot be made in the case of an abnormality, and a transmission system in the case of an abnormality is not yet constructed.
In order to solve such a problem, the invention 7 of the present application shows an example in which light emitted from an emergency light is used for communication.
Fig. 55 is a block diagram showing an embodiment of an emergency lamp and an emergency lamp wireless data transmission system according to claim 7 of the present application. Fig. 56 is an explanatory diagram of an example of an LED array as a light source. In the figure, 701 is an emergency light, 702 is a portable terminal, 711 is a battery, 712 is a switching unit, 713 is an LED array, 714 is a modem unit, 715 is a data memory, 716 is a light modulator unit, 721 is a light receiver unit, 722 is a demodulator unit, 723 is a display unit, and 731 is a lamp cover. The emergency lamp 701 includes a battery 711 as a power supply together with an external power supply, as in a general conventional emergency lamp, and further includes a switching unit 712 for switching to power supply from the battery 711 when power supply from the external power supply is stopped.
In the invention of claim 7, the LED array 713 is used as a light source for illumination instead of a conventional fluorescent lamp. Fig. 56 shows an example of the shape of the LED array 713. In the example shown in fig. 56(a), as in a general emergency light, an LED array 713 is provided in a lamp housing 731 in which characters and the like are shown. When used in this manner, as shown in fig. 56(B), a rod-like LED array 713 similar to a fluorescent lamp is used. For example, one or more LED elements may be arranged in a row. In addition, if the LED array 713 is such as described above, it can be used as a substitute for a fluorescent lamp for a dc lighting lamp, and the emergency lamp of the invention of the present application 7 can be configured by merely replacing the fluorescent lamp in the emergency lamp generally used with the LED array 713 as shown in fig. 56 (B). In this case, when AC power is supplied from the power line, the AC/DC converter may convert the AC power into DC power and drive the DC power. In an emergency light using a fluorescent lamp that is lit by AC, a DC/AC converter may be incorporated in the LED array 713 and used when the battery 711 is driven. Further, by using the LED array 713 having a shape that is an alternative to such a fluorescent lamp, the appearance can be made unchanged from that of a conventional emergency lamp.
In addition to the configuration as an alternative to the conventional illumination tube, for example, as shown in fig. 56(C), a configuration may be adopted in which a display of graphic characters or the like formed on a lamp shade 731 is directly displayed by an LED array 713. In general, if the graphic characters are those indicating an emergency exit, the graphic characters are formed of white and green colors, and therefore, the white LEDs and the green LEDs can be appropriately arranged to show the graphic characters. Of course, LEDs may be arranged in the same manner as in a color display device to display graphic characters and the like. In this case, it is preferable that the lamp shade 731 be transparent.
By using the LED array as the light source of the emergency light 701 in this way, since the LEDs have features such as low power consumption, it is possible to realize the same lighting time as in the conventional art even with a small battery capacity, and to realize the downsizing of the battery 711, and further, the downsizing, weight saving, and low price of the emergency light 701. On the other hand, if the battery capacity is the same, the lighting can be continued for a long time, and the display of the evacuation guidance can be displayed for a long time in a disaster. Further, since the LED has a long life, a maintenance interval such as replacement of the light source can be extended, or the number of maintenance operations can be reduced, and maintenance cost can be reduced. Of course, maintenance for maintaining performance such as dirt, battery life, and lighting inspection in case of disaster is desired. Further, the LED has high impact resistance, and it is expected that the lighting is continued while avoiding damage of the light source even in a severe disaster.
The emergency light 701 according to claim 7 of the present invention shown in fig. 55 further includes a modem unit 714, a data memory 715, and an optical modulator unit 716. Here, data is transmitted to the emergency light 701 by a communication method using a power line for supplying an external power source. The modem unit 714 separates modulated data transmitted by superimposing on the voltage of the external power supply, demodulates the data, and stores the demodulated data in the data memory 715. For example, by transmitting data to be transmitted from the emergency light 701 at the time of an abnormality from a computer or the like through a power line, the data can be distributed to the emergency light 701 through an external power supply at a time other than the time of the abnormality, and the data can be easily stored in the data memory 715. Further, various information such as data stored in the data memory 715 and the state of the emergency light 701 may be modulated and transmitted via the power line. This enables confirmation of rewriting of data and confirmation of operation of the emergency light 701 even in a remote place. In addition, the modem unit 714 can be configured as a demodulation function only when bidirectional communication is not performed. In addition, when data transmitted in the event of an abnormality is stored in the data memory 715, the modem unit 714 is not required.
The data memory 715 can store therein data to be transmitted in the event of an abnormality. It is desirable that the data memory 715 should consume as little power as possible, and that data stored during power switching should not be erased. For example, it is preferable to use a rewritable ROM, a nonvolatile RAM, or the like.
When an abnormality such as switching the power supply from the external power supply to the storage battery 711 is detected in the switching unit 712, the light modulation unit 716 reads out the data at the time of abnormality stored in the data memory 715, modulates the data, and superimposes the modulated data on the waveform of the power supplied to the LED array 713. Thus, the light emitted from the LED array 713 can be controlled to be on or off or to be in a light quantity according to the data modulated by the light modulation unit 716. Thereby performing data transmission using light. Of course, the data stored in the data memory 715 may be modulated and supplied to the LED array 713 for data transmission in addition to the abnormal time. In this case, the data to be transmitted in the case of an abnormality may be different.
The mobile terminal 702 is preferably a PDA with a camera, a mobile phone, or the like, and includes a light receiving unit 721, a demodulation unit 722, a display unit 723, and the like. The light receiving unit 721 receives light emitted from the LED array 713 of the emergency light 701 and converts the light into an electrical signal, and may be configured by a camera, a photodiode, or the like.
The demodulation unit 722 extracts and demodulates a data signal modulated in accordance with the electrical signal output from the light receiving unit 721 to acquire data. The acquired data can be used in various ways and is displayed on the display unit 723 here. Accordingly, data transmitted by light from the emergency lamp 701 in an abnormal state is displayed on the display unit 723. For example, a map or the like relating to an emergency exit or an evacuation route provided on a floor can be displayed on the display unit 723 using characters or images. Moreover, it is possible to transmit audio information, and audio information can be easily acquired by incorporating a speaker as in a mobile phone.
An example of the operation and use of an embodiment of the emergency lamp and the emergency lamp wireless data transmission system according to claim 7 of the present application will be described. In the emergency light 701, data to be sent out when an abnormality occurs is stored in the data memory 715 in advance. As one method, modulated data is superimposed on a waveform of an external power source and transmitted by power line communication as described above, and the modulated data transmitted from the external power source is acquired and demodulated in the emergency lamp 701. Alternatively, the data may be stored in advance in the ROM or the like outside, and then the ROM may be attached to the emergency light 701 as the data memory 715. For example, the memory card or the like may be mounted.
In the abnormal state, the optical modulation unit 716 reads data from the data memory 715, modulates the data, and superimposes the modulated data on a power waveform supplied to the LED array 713. By driving the LED array 713 with the power on which the modulated data is superimposed, the amount of light emission or on/off of the LED array 713 can be controlled at the same time as the light emission, and the data can be transmitted by the light.
In addition, when the holder of the mobile terminal 702 is abnormal, the holder can receive data transmitted by light from the emergency light 701 by directing the mobile terminal 702 to the emergency light 701. For example, in the case of an abnormality, it is often not known where the vehicle is located, and for example, even if evacuation is performed using emergency lights, it is not known how much the vehicle can be evacuated and the vehicle is not anxious. However, in the invention of the present application 7, various more detailed information that cannot be obtained only by the conventional emergency lamp can be obtained visually (or by sound, etc.) from the emergency lamp 701, such as the name of the building, the number of floors, a map of the floors, or an illustration of the evacuation route, and the next emergency exit by about m. Therefore, the danger can be reduced to some extent, and evacuation can be performed more quickly.
In general, since many mobile terminals 702 are battery-driven, they can be effectively used even in an abnormal state. Therefore, by using the emergency lamp which does not emit light from the external power supply or the mobile terminal 702 which does not require the external power supply in the event of an abnormality, evacuation guidance and the like can be smoothly performed even in the event of an abnormality, particularly in the event of the external power supply being turned off.
In the emergency lamp 701 according to the invention of the present application 7, electric power for operating the light modulation unit 716 and the like is required, but electric power required for operating the electronic circuit part is extremely small compared to electric power for emitting light. Therefore, even if the data transmission function using light is provided, it is hardly necessary to reinforce the battery 711 of the emergency light 701, and power consumption can be significantly suppressed and a separate device for transmitting data is not necessary as compared with a configuration in which radio waves or sound is transmitted in addition to light, for example. For example, even if infrared rays are used, power consumption cannot be avoided, and a separate transmitter must be provided. From the viewpoint of such reduction in power consumption and simplification of the apparatus, data transmission using light from the LED light source is advantageous.
Of course, the emergency lamp 701 illuminates the emergency exit or the evacuation route by the light emission of the LED array 713 in the same manner as in a normal emergency lamp, and there is no change in that it is effective even in an abnormal state for people who do not have the portable terminal 702. Even if the amount of light emission is controlled or turned on or off for data transmission, such a change in the amount of light is not perceived at all by the eyes of the person, and the function as an emergency light is not impaired. In this case, the characteristics of the LED can be used as described above, and thus the LED can perform a function as an emergency light more than the conventional one.
In addition, data transmission using such an emergency light 701 is not limited to the case of an abnormality. The information held in data store 715 may also be transmitted, often by light. Further, if data other than the data that is not used is also stored in the data memory 715, and the optical modulation section 716 changes the read data between the abnormal time and the time other than the abnormal time, it is possible to transmit, for example, information on surrounding stores, news, and the like to the mobile terminal 702. The emergency lamp 701 is not turned off when it is turned on, and is constantly turned on day and night. Therefore, the user of the mobile terminal 702 can constantly obtain information from the emergency light 701. Further, as described above, since the contents of the data memory can be rewritten as needed by the power line communication and can be updated constantly, the data can be distributed to the mobile terminal 702 in real time at a time other than the abnormal time.
In the above examples, an example of acquiring data by power line communication, a case of storing data in the data memory 715 in advance, and the like have been described. However, the present invention is not limited to this, and various methods can be used as a method of sending data to the emergency light 701. Fig. 57 is a block diagram showing another embodiment of the emergency lamp and the wireless data transmission system for the emergency lamp according to the invention of fig. 7. In the figure, 741 denotes an antenna, and 742 denotes a modem unit. In the example shown in fig. 57, data is transmitted from the outside by radio waves, received by the emergency light 701, and stored in the data memory 715. Data received by the antenna 741 is demodulated by the modem 742, and the data is stored in the data memory 715. Such data reception may be performed at a time other than the abnormal time. Since the power supply from the external power supply can be received at a time other than the abnormal time, such data reception using radio waves can be performed. Needless to say, when broadcast-type data distribution is performed, modem unit 742 has only a demodulation function.
Further, as shown in fig. 57, in addition to the radio waves, data distribution can be received in advance by a communication line other than the power line, such as an optical cable or a communication cable. Further, the use of the power line communication shown in fig. 55 has an advantage that data distribution can be received without providing an antenna or another cable.
As described above, according to the invention of the present application 7, the use of the LED as the light source can suppress the consumption of the battery due to the high power efficiency which is a characteristic of the LED, and the downsizing of the device and the prolongation of the light emission time due to the downsizing of the battery can be realized. Further, since the light source device has a long life, the interval of maintenance such as replacement of the light source can be extended, and the maintenance cost can be reduced. Further, the LED is excellent in impact resistance, and can be used as an emergency light without being damaged even in a severe disaster.
Further, since the response characteristics of the LED are good, the LED can be used as a transmission source of data using light by controlling the on/off state or the light amount. The emergency lamp has a battery mounted therein and continues to emit light even when power is cut off due to a disaster or the like. By using the light emitting device, it is possible to transmit information in various abnormal situations, such as a display of the position of an emergency exit or an evacuation stairway, an evacuation route to the emergency exit, and the like, which are stored in advance, in the abnormal situations. Such a function of transmitting data does not involve much power consumption and does not incur a cost, as compared with a case where a transmitting device such as a radio wave or infrared ray is separately provided, and therefore, the function as an emergency light, such as light emission at an abnormal time, is not impaired.
Further, the emergency light is not semi-permanently turned off when it is turned on, and therefore, the emergency light is installed in an eye-catching place without being affected by weather or seasons. Therefore, it is possible to transmit not only the unusual information but also general information such as surrounding advertisements and guidance, and it is expected that the information is frequently used other than at abnormal times, and the added value of the emergency light is improved.
< invention 8 >
Next, the invention of the present application 8 will be described as an application example 3. Although the above-described invention is described in a few as application examples, the 8 th invention of the present application shows an example of control of an illumination lamp installed on a road and communication by the illumination lamp.
The purpose of road lighting is to ensure safe and comfortable passage of vehicles or pedestrians by making the road bright, and further to be used for crime prevention. For road lighting, a fluorescent lamp, a halogen lamp, a sodium vapor lamp, or the like is generally used. In addition, recently, illumination of semiconductor light Emitting elements such as leds (light Emitting diodes) having a longer lifetime has been studied and actually provided. They are used from the viewpoints of light power efficiency, brightness, visibility, life, and the like, and are widely used from general roads to highways according to the characteristics of their lights, and are arranged every 10 meters on roads.
Generally, such lighting is often used for a long time when it is turned on, and is not turned on and off frequently. For example, if the light is dark, the light is turned on, and if the light is bright, the light is turned off. In addition, the tunnel is used in places such as tunnels for a long time without being divided into day and night.
On the other hand, traffic signals have been developed independently of road lighting. The purpose is to rectify the traffic of vehicles or people on the road. Since the vehicle is fixedly installed at an intersection, a crosswalk, or the like, there is a mobile type for road construction or the like. They are different from road lighting, change color from red to blue, yellow, or go on and off. For this reason, a white thermoelectric bulb has been used, and recently, an LED has been used. The use as a traffic signal requires easy lighting, good power efficiency, and a long life. A white heat lamp as a light source is inferior in power efficiency to other light sources, but is used because of its on-off property. Recently, LEDs having light-out characteristics, power efficiency, and long life have been replaced with other LEDs.
Fluorescent lamps, halogen lamps, sodium vapor lamps, and the like, which have been conventionally used for road lighting, and incandescent bulbs, which are used for traffic signals, are used separately according to the characteristics of the light source. Further, since the above-described separate use is made, an idea of using both road lighting and traffic signals has not been known.
Many numbers of accidents on roads are reported each year, but the handling of the accidents after they have occurred is also important. This is to prevent further accidents without causing traffic congestion. As described above, the traffic signal is installed at an intersection, a crosswalk, or the like to perform traffic regulation at the installed place, but when an abnormality such as an accident occurs on the road, there is no function of performing traffic regulation on the abnormality. Therefore, in the past, only the following vehicles pay attention to the accident immediately after the accident. If there is an accident notification soon the police arrive at the scene to do traffic regulation. However, since the security up to this point has to rely on the attention of individuals, there is a high possibility of the reoccurrence of an accident, such as causing a car hit in the accident, a rear-end collision at the very end of a jam accompanying the accident, or the like.
In general, when an accident occurs, a person who is involved in the accident burns a smoke pipe to notify a following vehicle of the occurrence of the accident. However, it is the case that the smoke tube is not readily available. Further, the smoke tube may be exposed to fire or smoke, which may be in the vicinity of combustible materials, and the smoke may obstruct the view. Further, the user cannot pay attention from a distant place because of the low position. Further, there is a disadvantage that remote control is impossible.
A reflection plate is often provided behind an accident car or the like, instead of using a smoke tube. However, since the vehicle is often placed near the accident vehicle and is placed at a low position, the vehicle cannot be seen from a distant place and cannot know the accident without being close to the vehicle. Further, since the reflection plate is installed by a person, there is a problem that remote control is not possible.
The hazard lamps of the vehicle are simple methods as a method for accident occurrence or attention calling of the following vehicle. However, the vehicle itself may not be able to use the lamp due to an accident or the like. Further, since the vehicle is installed in the vehicle body area of the vehicle, the vehicle can be recognized from several vehicles in the following and surrounding areas, but is often not recognized from a distant place or the back of a large vehicle. In this case, the remote operation cannot be performed because the vehicle is operated by a person.
In addition, if the police arrive at the scene, a hand signal or a simple signal device is arranged to carry out traffic regulation. However, the simple signaling device needs to be transported from a police station or the like after an accident occurs, and is not adaptable to the accident. In addition, remote manipulation is not possible due to the simplicity.
An information display panel is provided on an expressway, a trunk line, or the like to display accident information, congestion information, or the like, so that a user can visually acquire the information. The information to be displayed is mostly sent to the information display panel by remote manipulation. However, since the information display panel is provided separately from the above-described illumination, traffic signal, and the like, the cost is high, and the number of the information display panels to be provided is not comparatively small as compared with the illumination, traffic signal, and the like. Therefore, there is a problem that the acquisition of information by the information display panel is very limited.
The illumination light communication has not been considered conventionally for application to the traffic system as described above, and an application example thereof is shown in the 8 th invention of the present application.
Fig. 58 is a block diagram showing a road illumination control system according to embodiment 1 of the 8 th invention of the present application. In the figure, 801 denotes an abnormality detection unit, 802 denotes an illumination control unit, and 803 denotes an illumination lamp. The abnormality detection unit 801 detects an abnormality on a road. For example, an emergency call can be set on an expressway, and the use of the emergency call by a user can be detected as an abnormality occurrence, or the abnormality occurrence can be instructed by an operator at a monitoring center corresponding to the emergency call. Similarly, a notification to the police or the like may be triggered to indicate the occurrence of an abnormality. Alternatively, the abnormality may be detected by a monitoring device that monitors the road.
The lighting control unit 802 selects a lighting group for lighting control according to the abnormality detection result in the abnormality detection unit 801 and performs lighting control for the selected lighting group, with the plurality of illumination lamps 803 as one or more lighting groups. The illumination control can be performed, for example, by turning on or off the illumination lamp 803 or by controlling the amount of light of the illumination lamp 803. In addition, if the illumination lamp 803 can change the light emission, the color of the light emission can be controlled. The illumination lamps 803 constituting an illumination group are arbitrary, and if one illumination lamp 803 is set as an illumination group, for example, illumination is controlled for one illumination lamp 803 one by one. In addition, instead of the continuous illumination lamps 803, every other illumination lamp may be configured as an illumination group. Of course, the number and position of the illumination lamps 803 constituting an illumination group may be different for each illumination group, and may be changed according to, for example, the position where an abnormality occurs, the scale of the abnormality, or the like. In addition, when all the illumination lamps 803 are controlled in the same manner (that is, when only one illumination group exists), the process of selecting an illumination group is not necessary.
A plurality of illumination lamps 803 are provided on the road similarly to the illumination lamps generally provided, and illuminate the road in the dark. At the same time, the lighting control unit 802 may be configured to perform lighting control such as on/off control, light amount control, or light color control in accordance with an instruction from the lighting control unit. Unlike conventional mercury lamps, light sources that respond to a change in the amount of light or light being turned on or off for several seconds or less are used. Such a light source is preferably a semiconductor light emitting element such as an LED or an ld (laser diode). For example, when an LED of a system in which 3 color lights are mixed and emitted as white light is used as a light source, the emission color can be easily changed.
Fig. 59 is an explanatory diagram of an example of the illumination mode of the illumination lamp at the time of occurrence of an abnormality. 811 is the scene of an accident, 812 is an emergency telephone device, and 813-818 is an illuminating lamp. Fig. 59 shows an example of an accident occurring on an expressway, and an accident scene 811 is represented by x. In this example, the emergency telephone device 812 provided in the roadside area realizes the function of the abnormality detection unit 801, and when the accident party or another 3 rd person transmits the occurrence of the accident to the center or the like by using the emergency telephone device 812, the accident occurrence is transmitted from the emergency telephone device to the lighting control unit 802.
The lighting control unit 802 selects lighting groups for lighting control from lighting lamps 813 to 818 (corresponding to the lighting lamps 803 in fig. 58) provided in the vicinity of the notified emergency telephone device 812 from the position thereof, and controls lighting of the selected lighting groups. For example, when 2 illumination lamps are used as the illumination group, the illumination group of the illumination lamps 813 and 814 closest to the accident site 811 and the illumination lamps 815 and 816 next closest to the accident site 811 are selected as the illumination group to be subjected to illumination control. Then, the lighting control is performed for these lighting groups.
As the illumination control, for example, the illumination lamps 813 and 814 closest to the accident site 811 may be controlled to blink fast to transmit the situation where the accident site 811 is near to the driver, and the illumination lamps 815 and 816 may be controlled to blink slow to transmit the situation where the accident site 811 is in front to the driver. Alternatively, if the illumination lamps can be controlled in illumination color, for example, the illumination lamps 813 and 814 closest to the accident site 811 may be controlled in such a manner that the illumination color is changed to red to inform the driver that the accident site 811 is nearby, and the illumination lamps 815 and 816 may be controlled in such a manner that the illumination color is changed to yellow to call the driver's attention.
By performing such illumination control of the illumination lamp, the driver of the vehicle approaching the accident scene can be urged to pay attention from there, and the illumination lamp can function as a kind of traffic signal. In particular, since the illumination lamp is installed at a high position on the road, it can be recognized well even from a distance. Since such lighting control can be performed immediately after the occurrence of an accident, it is possible to prevent a secondary accident by calling attention without waiting for the arrival of the police. Further, since the illumination lamps are arranged at intervals of 10 meters, the occurrence of the difference can be finely transmitted to road users such as drivers. Since the illumination lamp is generally installed on a road, it is possible to effectively use the existing infrastructure without providing a separate display device or the like for notifying the driver of an accident or the like.
Further, the illumination control is not limited to the above example. For example, the number and position of the illumination lamps constituting the illumination group are arbitrary, and various illumination methods such as changing the light amount, changing the illumination color together with turning on and off or changing the light amount, and the like may be combined in addition to turning on and off. In particular, the illumination on the road cannot be guaranteed to be particularly dangerous because the illumination lamp is turned off at night. In such a case, it is preferable to perform lighting control on the lighting lamps every other lamp, or alternately perform on-off control so as to ensure the illuminance on the road.
In the above example, the illumination control of the illumination lamp is performed by the operation of the emergency telephone device 812, but the illumination control may be instructed from the center after, for example, a notification to the center or the like is made by the emergency telephone device 812. The same applies to the case where an accident or the like is recognized by a monitoring camera or the like or is determined by an operator, other than the emergency telephone device 812. Further, the size of the accident or the like may be determined based on information from a reporter or information from a monitoring camera, and only lighting control for calling attention may be instructed if the accident is a minor accident or a faulty vehicle.
In addition to the occurrence of an accident as described above, for example, there are many accidents in the vicinity of the rearmost part of a jam, and the illumination of the illumination lamp can be controlled in the vicinity to call the driver for attention. Similarly, instead of providing a separate warning light in the construction section, or in combination with a warning light or the like, the lighting control of the lighting lamp can be used to call attention.
Further, in the case of crime, emergency patient, fire, or other disaster, the illumination of the illumination lamp may be controlled for the purpose of guiding the emergency vehicle. In this case, in addition to the illumination control in the vicinity of the place of occurrence as in the case of an accident, the illumination control may be performed on an illumination lamp in front of the emergency vehicle, and the general vehicle may be notified of the approach of the emergency vehicle. For example, the lighting control may be performed by selecting a lighting group for performing lighting control in accordance with a radio wave from an emergency vehicle, guidance from a center, or the like.
Fig. 60 is a schematic configuration diagram showing a 2 nd embodiment of a road illumination control system according to the 8 th aspect of the present application. In the drawings, the same portions as those in fig. 58 are denoted by the same reference numerals, and redundant description thereof will be omitted. Reference numeral 821 denotes a vehicle, 822 denotes a light receiving part, 831 denotes a pedestrian, and 832 denotes a portable terminal. By controlling the illumination of the illumination lamp 803 as in embodiment 1, information such as calling attention can be transmitted to the driver or the like. If such illumination control is performed at high speed, illumination light by the illumination lamp 803 can be used for communication of information. The illuminating light is very powerful and reliable communication is possible by using it to transmit information.
When a semiconductor light emitting element such as an LED or an LD is used as a light emitting device of the illumination lamp 803, turning on and off or controlling the amount of light can be performed at a very high speed. When the lighting or the light amount control is performed at a speed higher than a certain speed, the lighting 803 is continuously turned on because the eyes of a person cannot perceive the lighting or the light amount change, and thus a function as road lighting can be realized. Further, since light is used, communication can be performed at a communication speed as high as a degree of visibility from human eyes (several Hz or less) to a communication speed of several 100MHz or more.
In embodiment 2, the illumination control unit 802 is given information to be transmitted. Then, in accordance with the transmission information, the illumination control section 802 controls on/off of the illumination lamp 803, the light amount, the color, and the like, and causes the illumination section 3 to emit illumination light modulated in accordance with the transmission information.
On the other hand, a vehicle 821 passing on a road may be provided with a light receiving unit 822 for receiving light emitted from an illumination lamp 803, converting the light into an electrical signal, and then demodulating the signal to acquire information transmitted from the illumination lamp 803. Since the illumination lamps 803 are generally arranged so that the road is not dark, if the same information is transmitted by illumination light from a plurality of illumination lamps 803, the information can be acquired by illumination light from different illumination lamps 803 even while the vehicle 821 is traveling. For example, distribution of program information such as traffic information, news, and music is possible.
Similarly, when the pedestrian 831 carries a mobile terminal 832 having a light receiving unit such as a camera, information transmitted from the illumination lamp 803 can be acquired by receiving illumination light from the illumination lamp 803 by the mobile terminal 832. In the case of transmitting information for the pedestrian 831, since the area illuminated by one illumination lamp 803 is not so wide, it is also possible to perform communication for each narrow area by changing the information to be transmitted for each illumination group of one or a plurality of illumination lamps 803. Even if the pedestrian 831 is moving, it takes time to move from under a certain illumination lamp 803 to under the next illumination lamp 803, and therefore communication can be performed without being interrupted in the middle unless a large amount of information is transmitted. For example, it is conceivable to distribute positional information of the illumination lamp 803, map information of the surroundings, and the like, or distribute information of a store, a public institution, and the like in the vicinity thereof. Of course, the information transmitted from the illumination lamp 803 is arbitrary, and is not limited to these examples.
Further, by providing a light receiving section in the illumination lamp 803, bidirectional communication using light can be performed as described in japanese patent application laid-open No. 2003-4560, for example. It is possible to use the internet by the vehicle 821 while traveling by enabling two-way communication. Further, since the response from the vehicle 821 can be obtained, it is also possible to perform the linkage with the traffic control or the traffic monitoring system.
Further, the illumination control for calling attention to the driver or the like as described in embodiment 1 and the illumination control for information transmission as described in embodiment 2 may be performed simultaneously, and the illumination lamp 803 may be used more efficiently.
In general, the amount of light emitted from the illumination lamp 803 decreases as the light leaves the illumination lamp 803. In the case of normal road lighting, a certain degree of light quantity reduction is tolerated as long as there is no obstacle to walking, driving of a vehicle, or the like. However, in the case of performing communication using illumination light as described in embodiment 2, there is a concern that the communication quality may be deteriorated due to a decrease in the light amount. Therefore, it is desirable to prevent the light amount from decreasing as much as possible even if the illumination lamp 803 is separated.
Fig. 61 is a schematic sectional view showing an example of the shape of a substrate of a light emitting portion of an illumination lamp. In the figure, 841 is a substrate, and 842 is a semiconductor light emitting element. Although a plurality of semiconductor light-emitting elements 842 are generally used for illumination, the plurality of semiconductor light-emitting elements 842 are mounted on a substrate 841 so as to be incorporated into an illumination lamp 803. In this case, when the substrate 841 is a flat surface, the light emitted from the semiconductor light-emitting element 842 is directed substantially perpendicular to the substrate 841. Therefore, the light intensity is bright under the illumination lamp 803, but the light intensity decreases when the light is separated from the illumination lamp 803.
In the 8 th invention of the present application, therefore, the substrate 841 is bent as shown in fig. 61. In particular, it is preferable to curve the road or the like in the extending direction. When the substrate 841 is bent in this way, the semiconductor light emitting elements 842 mounted on the substrate 841 are radially oriented in different directions. Therefore, not only under the illumination lamp 803 but also in the peripheral direction, light from the semiconductor light-emitting element 842 is directly irradiated, and a decrease in the amount of light when the illumination lamp 803 is separated can be suppressed.
Further, when the illumination lamp 803 is separated, the distance from the semiconductor light emitting element 842 as a light source to the road surface is increased, and the light amount is decreased. In order to prevent the decrease in the light amount due to such a distance, for example, it is preferable to make the directivity narrower as the distance from the end of the substrate is closer, to reduce the spread of the light emitted from the semiconductor light emitting element 842, and to make the light reach as far as possible even at a long distance. In a simple manner, for example, the semiconductor light emitting elements 842 disposed on the substrate 841 at an angle exceeding ± δ degrees from the right below the illumination lamp 803 are preferably configured to narrow the directivity thereof. Of course, the directivity may be gradually narrowed as the angle from the right below is increased.
With this configuration, even in a position away from the illumination lamp 803, the light having narrow directivity reaches the position, and thus the decrease in the light amount can be suppressed. Accordingly, high-quality communication can be performed by light from illumination lamp 803 even when the illumination lamp 803 is separated from the illumination lamp 803.
It is also conceivable to control such directivity by changing the package of each semiconductor light emitting element 842, or by providing a lens function to the transparent cover of the street lamp 3, for example.
As described above, according to the 8 th aspect of the present invention, by using the lighting devices installed in many ways on the road for purposes other than lighting, for example, turning on and off the lighting lamps, controlling the amount of light, or controlling the color of the lighting, it is possible to quickly call attention to a passing person or vehicle in the event of an accident, a traffic jam, a construction section, or the like, to prevent an accident, and to realize smooth traffic. Further, by transmitting information by turning on/off the illumination lamp, controlling the amount of light, controlling the color of illumination, or the like, it is possible to provide various information to the road user.
In addition, when a large number of semiconductor light emitting elements are used as a light source of an illumination lamp, a substrate on which the semiconductor light emitting elements are mounted is bent, whereby it is possible to maintain high-quality communication while suppressing a decrease in light quantity even when the substrate is separated from the illumination lamp.
< invention 9 >
Next, the invention of the present application 9 will be described as an application example of the 4 th embodiment. The 9 th invention of this application shows an example in which communication using light is performed between a moving body such as a train and the ground.
Conventionally, a wireless system is used as a communication device for connecting a moving object such as a train to the ground. In general, a method used in a mobile phone or the like is to provide a base station and perform communication between the base station and a mobile station. However, since the electric wave is blocked in the tunnel, communication cannot be performed. For this reason, there is a problem such as a call being interrupted in a telephone or the like or a session being disconnected when data communication is performed. In addition, since radio waves attenuate according to the distance from the base station, the transmission speed cannot be greatly increased. Further, the communication quality is not so good due to the influence of attenuation and the like.
In a new trunk line or the like, a Leaky Coaxial Cable (LCX) is laid on a line or near the line and used for communication of public telephones. The leaky coaxial cable utilizes the property of passing a high-frequency current through the cable and radiating electromagnetic waves in the surroundings. Since the leaky coaxial cable is laid close to a train such as a new railway line, which is traveling, the attenuation amount due to the distance does not vary so much, and high-quality communication can be performed. Further, if a leaky coaxial cable is also laid in a tunnel or the like, communication can be performed. However, since reflection of radio waves by wall surfaces occurs in a tunnel, the radio waves are strongly affected by multipath fading, and thus, there is a disadvantage that communication characteristics are significantly deteriorated. Further, the communication speed is also about 2.6MBps, and further speeding up is desired.
With the recent improvement of network technology, it is promoted to construct a ubiquitous network society that can communicate anywhere and anytime. As a communication device which is responsible for such ubiquitous network society, the conventional communication device is insufficient in both communication speed and communication quality as described above, and a communication technology capable of performing communication at a higher speed and with higher quality is desired.
On the other hand, optical fibers are used for high-speed, large-capacity communication between fixed stations. The optical fiber technology is used for suppressing transmission loss in general, and attempts are made to make the light emitted from the optical fiber reach the light receiving side as much as possible. Therefore, the optical fiber for communication is configured to suppress light leakage as much as possible.
As an optical fiber different from such a general optical fiber for communication, for example, a leaky optical fiber which leaks light from the surface of the optical fiber as described in japanese patent laid-open No. 2001-133652 has been developed, and there are various methods in the development. Japanese patent application laid-open No. 2001-133652 discloses the use of such a leaky optical fiber for guidance, decoration, or optical guidance, and further discloses the use thereof for communication. However, although it is used for communication, there is no description at all about how to use a leaky optical fiber. As described above, the optical fiber is used between fixed stations, but when the leaky optical fiber is used in such a use form, the leakage of light becomes a transmission loss, and the communication quality is deteriorated. Therefore, the leaky optical fiber cannot be used for communication between conventional fixed stations, and there is no case of performing communication using the leaky optical fiber.
Fig. 62 is a schematic configuration diagram showing an embodiment of the invention 9 of the present application. In the figure, 911 is a mobile body, 912 is a light receiving unit, 913 is a demodulation unit, 914 is a modulation unit, 915 is a light emitting unit, 916 is a leaky optical fiber, 921 is a network, 922 is a signal control unit, 923 is a light emitting unit, 924 is a leaky optical fiber, and 925 is a light receiving unit. The moving object 911 moves on a fixed path, for example, a train, a carrier, or the like is considered, and the invention of the present application 9 is not limited to these. Here, the mobile object 911 will be described as an example of a train.
On the path along which the mobile object 911 moves, the leaky optical fiber 924 having an appropriate length is laid along the path of the mobile object 911. For example, the cable may be laid inside a track as a track of a train, or may be laid beside the track, on a side wall such as a soundproof wall, or along with a trolley line if the cable is a train.
The leak optical fiber 924 can be the optical fiber described in the above-mentioned Japanese patent application laid-open No. 2001-133652, or any other optical fiber having the property of leaking light. The length of 1 leaky optical fiber 924 is preferably several tens of meters or more if the moving object 911 is a train. The laying length of each 1 stripe may be determined in consideration of attenuation due to light leakage. The leaky optical fiber 924 may be laid in a row or may be laid so that a part of the light emitting section is overlapped without a crack.
A light emitting unit 923 for transmitting an optical signal to the leaky optical fiber 924 is provided at one end of the leaky optical fiber 924, and drive control is performed by the signal control unit 922. The light Emitting unit 923 may be, for example, a Laser Diode (LD) or a light Emitting Diode (led). Particularly, LD preferably has sharp directivity. In either case, the optical fiber has a high-speed response characteristic, and the signal control unit 922 performs ON/OFF or light amount control at high speed to modulate the optical fiber, thereby enabling an optical signal to be emitted to the leaky optical fiber 924.
The signal control unit 922 drives and controls the light emitting unit 923 in accordance with information transmitted from the network 921 to the mobile object 911, and transmits an optical signal from the light emitting unit 923 to the leakage optical fiber 924. The optical signal received by the light receiving unit 925 is demodulated and the information is sent to the network 921. Further, the mobile object 911 may be provided with a function of performing operation control so that the mobile object 911 operates when entering the irradiation range of the leak light by the leak optical fiber 924 when transmitting information to the mobile object 911. Further, the switching control of the leaky optical fiber 924 according to the movement of the mobile body 911 may be performed by communication between the signal control units 922 or by control using another control device.
The network 921 may be configured by an arbitrary channel, and may be a wired communication cable or the like. Of course, the communication cable may be connected to a backbone network such as the internet.
The light receiving unit 925 is disposed substantially opposite to the leak optical fiber 916 provided in the mobile object 911, receives light leaking from the leak optical fiber 916, converts the light into an electrical signal, and transmits the electrical signal to the signal control unit 922. The light receiving section 925 can be a light receiving element such as a Photodiode (PD).
On the other hand, the mobile object 911 is provided with a light receiving unit 912 and a demodulation unit 913 as a configuration for receiving information, and a modulation unit 914, a light emitting unit 915, and a leak optical fiber 916 as a configuration for transmitting information. The light receiving unit 912 is disposed substantially opposite to the leakage optical fiber 924 running along the movement path, and receives the optical signal leaked from the leakage optical fiber 924 and converts the optical signal into an electrical signal. The light receiving section 912 can also use a light receiving element such as PD, as in the light receiving section 925 described above.
The demodulation section 913 demodulates the signal received and converted into the electrical signal by the light receiving section 925, and acquires the transmitted information. The demodulated information is sent to a computer or network within mobile 911.
Information transmitted from the mobile object 911 is transmitted to the modulation unit 914, and the modulation unit 914 performs drive control so as to turn ON/OFF the light emitting unit 915 or change the light amount in accordance with the information to be transmitted. The light emitting section 915 can be configured by an LD, an LED, or the like, as in the light emitting section 923 described above, and transmits an optical signal to the leakage optical fiber 916 according to drive control by the modulation section 914.
The leaky fiber 916 is provided along the moving direction of the mobile body 911, similarly to the leaky fiber 924 described above. Then, the optical signal sent from the light emitting section 915 leaks from the surface thereof.
Fig. 63 is an explanatory diagram of an example of an operation performed when information (downlink) is transmitted to the mobile 911 in the first embodiment of the present invention 9. When the mobile object 911 arrives at the leaky optical fiber 924, the signal control unit 922 drives and controls the light emitting unit 923 in accordance with information to be transmitted to the mobile object 911 received in advance from the network 921, and transmits the modulated optical signal from the light emitting unit 923 to the leaky optical fiber 924.
The optical signal emitted from the light emitting portion 923 travels through the leaky optical fiber 924, and a part of the optical signal leaks from the surface of the leaky optical fiber 924. When the light receiving unit 912 of the mobile object 911 comes on the leak optical fiber 924 as shown in fig. 63(a), the light receiving unit 912 receives the optical signal leaking from the leak optical fiber 924 and converts the optical signal into an electrical signal. Then, the optical signal converted into the electrical signal at the light receiving section 912 can be demodulated by the demodulating section 913 to obtain information.
For example, when the leakage optical fiber 924 is laid on a track such as a line, the light receiving unit 912 is provided under the floor of the mobile object 911. In general, since light around sunlight or street lamps is irradiated on the track, the optical signal leaked from the leakage optical fiber 924 is easily affected by the disturbance light. However, when a moving object 911 such as a train exists, the moving object 911 covers the track. Therefore, the leakage optical fiber 924 and the light receiving section 912 of the mobile object 911 enter the shadow of the mobile object 911, and become a very dark state. Therefore, the influence of interference light or the like such as sunlight or street lights can be remarkably reduced, high-quality communication can be performed, and the communication speed can be improved. Of course, even when the leakage optical fiber 924 is laid out outside the track, the optical signal can be detected by, for example, receiving the optical signal together with the ambient light by the light receiving section 912, and taking a measure against the normal disturbance light such as detecting a difference with the ambient light in the subsequent signal processing. The mobile object 911 is an electric car or the like, and electromagnetic noise is frequently generated by a flash light or the like, but an optical signal can be communicated without being affected by such electromagnetic noise. Further, the radio wave is not affected by attenuation even in a tunnel or the like, and high-quality communication and high-speed communication are possible compared with the conventional radio wave.
The moving body 911 travels on the track as it is. For example, from (a) to (B) in fig. 63. Meanwhile, although the light receiving unit 912 moves along with the movement of the moving body 911, the distance from the leaky fiber 924 extending in the moving direction of the moving body 911 does not change greatly. Since the leak optical fiber 924 leaks the incident light substantially uniformly, the intensity of the optical signal received by the light receiving unit 912 of the mobile object 911 does not change even when the mobile object 911 moves. Thus, high-quality, high-speed communication can be continuously maintained even when the mobile object 911 moves.
When the moving body 911 further moves, the moving body moves beyond one end of 1 leaky optical fiber 924, but in this case, it is possible to continue receiving information by receiving leaky light from the leaky optical fiber 924 which is laid next. At this time, for example, if the leakage range of the light leaking out of the optical fiber 924 is repeated, the communication is not interrupted.
In this way, information transmission (downlink) to the mobile 911 can be performed. In addition, when a plurality of leakage optical fibers 924 are laid as shown in fig. 62, it is possible to arbitrarily control which light emitting portion 923 is driven and controlled. For example, in the case of a train, the drive control of the light emission start unit 923 may be started in conjunction with a control system such as a crossing or the like or may be started when the approach of the train is detected. In the case of bidirectional communication between mobile objects 911, it is also possible to detect that one or more light receiving units 925 following the mobile object 911 receive an optical signal from the mobile object 911 as shown in fig. 62, and start driving control of the light emitting unit 923. Of course, the light emitting unit 923 may be constantly driven and controlled in accordance with information.
Fig. 64 is an explanatory diagram illustrating an example of an operation performed when information (uplink) is transmitted from the mobile 911 in an embodiment of the present invention 9. Even in the case of an uplink in which information is transmitted from the mobile 911, communication can be performed in the same manner as in the above-described downlink case. In the mobile object 911, information to be transmitted is modulated by the modulation unit 914, and the driving of the light emitting unit 915 is controlled by the modulated information, so that an optical signal is emitted to the leak optical fiber 916. The optical signal emitted from the light emitting section 915 travels through the leaky optical fiber 916, and a part leaks from the surface of the leaky optical fiber 916.
As shown in fig. 64(a), when the region of the mobile object 911 where light leaks out of the leak optical fiber 916 comes to the external light receiving unit 925, the light receiving unit 925 receives the light signal leaking out of the leak optical fiber 916 and converts the light signal into an electrical signal. Then, the signal control unit 922 can demodulate the optical signal converted into the electrical signal to acquire information.
In the case of such information transmission (uplink) from the mobile 911, as in the case of the downlink, for example, in the case where the leaky optical fiber 924 is laid on a track such as a line, communication can be performed in the shadow of the mobile 911 itself, and the influence of the disturbance light can be reduced. Further, since the influence of electromagnetic noise, attenuation, or the like is small, high-quality and high-speed communication is possible.
The moving body 911 travels on the track as it is. For example, from (a) to (B) in fig. 64. In this case, in contrast to the downlink case described above, the leaky fiber 916 moves simultaneously with the movement of the mobile 911. However, the distance between the leak optical fiber 916 of the mobile body 911 and the light receiving unit 925 provided outside does not change greatly. Since the leak optical fiber 916 leaks incident light substantially uniformly, even if the moving body 911 moves and the position of the leak optical fiber 916 facing the light receiving section 925 changes, the intensity of the optical signal received by the external light receiving section 925 does not change as much. Thus, high-quality, high-speed communication can be continuously maintained even when the mobile object 911 moves.
Thus, information can be transmitted (uplink) from the mobile 911. Further, when the mobile object 911 moves, the optical signal leaked from the leakage optical fiber 916 of the mobile object 911 may be received by the next other light receiving unit 925 disposed at a predetermined interval. The light receiving unit 925 may be disposed at an interval within the length of the leakage optical fiber 916 provided in the mobile object 911.
By using the downlink and uplink communications in combination, bidirectional communication with the mobile 911 is possible. In addition to business applications such as train operation management, a user on a train can use a network 921 such as the internet from a terminal device to the mobile object 911. Of course, a configuration may be possible in which unidirectional communication is realized by a configuration only in one direction. For example, a downlink-only broadcast system for transmitting information to the mobile 911 may be constructed and video information may be distributed to each mobile 911.
As described above, according to the invention 9 of the present application, the mobile object 911 has substantially the same configuration as the structure on the ground. That is, the configuration on the transmission side may include the leak optical fiber and the light emitting portion, and the configuration for driving and controlling the light emitting portion, and the configuration on the reception side may include the light receiving portion and the demodulation portion. Since the configuration is the same, the communication speed at the time of transmitting information to the mobile object 911 and the communication speed at the time of transmitting information from the mobile object 911 can be made substantially the same. It is also possible to animate the speed of communications over 1GBps both uplink and downlink by leaking fiber. For example, when the passenger of the mobile 911 uses the external network 921 as described above, a sufficient communication speed can be secured even when the passenger 100 communicates at the same time at 10 MBps.
As described above, according to the invention of the present application 9, the influence of attenuation and the influence of electromagnetic noise can be eliminated by using light as a medium for wireless communication due to its characteristics, and high-quality and high-speed mobile communication can be realized. In addition, both transmission of information to a mobile object (downlink) and transmission of information from a mobile object (uplink) can be performed with the same configuration, and both directions can be performed with the same communication speed. Further, for example, when communication is performed between the floor of a train and a line, communication can be performed in a dark state in the shadow of the train, and the influence of disturbance light can be significantly reduced to perform high-quality communication. According to the invention of the present application 9, various effects which cannot be achieved by the conventional mobile communication using radio waves are obtained as described above.
The present invention has been described above with reference to the 1 st to 9 th inventions. However, it is needless to say that the present invention is not limited to the ranges described above, and various modifications may be made.