Disclosure of Invention
The following provides a description of various embodiments of luminaires, systems, and methods for dynamically and automatically controlling day or night color temperature changes and manually overriding the automatically changed color temperature. Manual override of task dimming may occur at any time of day, and preferably, a change in color temperature due to a manual change (either increasing or decreasing color temperature, depending on the desired task) to an automatically changing color temperature may efficiently and advantageously maintain a truer simulation of externally occurring actual daylight changes that vary with time in the day or night.
According to an embodiment, there is provided a lighting device comprising a plurality of chains of LEDs, wherein each chain may be configured to produce illumination for the lighting device at a chromaticity consistent with a chromaticity setting. For example, each chain may be one of the dominant chromaticities, such as red, green, or blue. Moreover, the chain may also have a chromaticity consistent with the white chromaticity setting. The lighting device may further comprise a driver circuit coupled to the plurality of LED chains. The drive circuit is configured to generate a drive current to each chain, and based on the drive currents provided to those chains, the drive currents may automatically change the color temperature output from the lighting device according to the time of day. For example, if the ratio of the currents driven to the LED chains is modified at periodic times, that modification may occur automatically based on a time output from, for example, a timer.
The automatic modification or change of the color temperature does not involve actuating a trigger such as a slider on a user interface of the remote control. Rather than a manual override involving a change in intensity values sent from the remote control to the interface or from the dimmer to the controller, an automatic change in color temperature occurs through a parameter or set point, pre-existing as stored content in the memory of one or more luminaires, and invoked when the one or more luminaires receive a time of day signal sent from the remote control. Manual override necessarily involves user actuation of a trigger on the user interface, while automatic change of color temperature occurs when the appropriate time of day signal is sent periodically and automatically, without any user actuation of the trigger.
The lighting device may further comprise a control module coupled to the driving circuit for sending, for example, a brightness value generated by the task dimming function. The luminance value is sent to each of a plurality of LED chains. The control module may comprise an interface coupled to receive the intensity values from a remote control, which is remotely located, for example, with respect to the lighting device, in particular, with respect to a control module comprising a controller within the lighting device. The storage medium may comprise a non-linear first mapping of intensity values received from the remote control to luminance values sent to the LED chain. The storage medium may further comprise a second mapping of color temperature as a function of time of day. The control module may also include a controller within the lighting device coupled to receive the change in intensity values from the interface and to retrieve the first and second mappings from the storage medium to produce a change in color temperature at a first time of day relative to a second time of day. According to one embodiment, the change in intensity values may reduce the color temperature during the day as part of the dimming function. However, depending on the task, the change in intensity values may increase the color temperature if reverse dimming is required, for example on cloudy days where higher temperatures are required for the reading task. Also, for example, if the current analog output is nighttime and the user wishes to increase the color temperature when he/she wakes up from bed, the intensity value may be increased.
The user moving a trigger on the remote control changes the intensity value sent to the control module of each lighting device in a group of lighting devices in, for example, a room of a structure, accordingly. Task lighting may be manually controlled on a room-by-room basis as the intensity increases or decreases. Moreover, the manual override based on the respective room application overrides the automatic change of the color temperature output that is also based on the respective room application. For example, manually actuating a single trigger on a remote control overrides an automatic change in color temperature output of the entire group of luminaires using an improved discovery and validation process for group projection. The change in intensity may correspond to a fixed or variable change in brightness applied to the LED chain. A fixed change in brightness may produce a greater change in color temperature output from the LED chain during a first time of day than during a second time of day, while a variable change in brightness may produce an equal change in color temperature output from the LED chain during the first time of day as during the second time of day. According to the first embodiment, even if the luminance output from the LED chain is kept constant throughout the day but is changed by the same amount throughout the day, the color temperature may be changed more during the first time of the day than during the second time of the day, or according to the second embodiment, the color temperature may be changed by the same amount during the first time of the day as during the second time of the day even if the luminance output from the LED chain is changed throughout the day but is changed by the same amount throughout the day.
Each LED chain of the plurality of LED chains may produce a different spectral wavelength range than another LED chain. A driving current is applied to each of the plurality of LED chains, the driving current automatically changing as a ratio between the plurality of LED chains over time of day. The dynamic and automatic change function is not terminated until the interface receives the strength value. The interface coupled to receive the intensity values is an interface received during a lighting task, which may be either dimming or reverse dimming, e.g., triggered from a manual override of a user via a remote control, to temporarily stop the dynamic and automatic change of color temperature over time of day. Alternatively, the dynamic and automatic change of the color temperature may continue at the level of dimming or reverse dimming. For example, when the next time of day signal from the timer invokes the next color temperature within the automatically changing color temperature display, the resulting color temperature may be greater or less than the color temperature typically resulting from the display. Manual override occurs when a user actuates a button or slider on the remote control or on an AC power coupled dimmer that includes a triac (triac). For example, actuation of a trigger on a remote control or triac may cause a button or slider position to be output from the remote control or dimmer to the interface as an intensity value. Manual dimming override will cause a change in the brightness output from the plurality of LED chains. The manual dimming override and resulting change in brightness output will affect the LED output color temperature differently depending on the time of day that the user actuates a trigger (e.g., a button or slider).
For example, if the color temperature output from a chain of LEDs dynamically changes automatically from, for example, 2300Kelvin to 6000Kelvin from sunrise to midday, then a manual task lighting override may occur by manually dimming the brightness output. Manual dimming of the brightness in the morning will have a greater effect on lowering the color temperature than if dimming of the brightness occurred at, for example, noon hours. Even if the brightness dimming level is the same, the lowering of the color temperature via task dimming is advantageously greater in the morning than during the noon. This advantage is critical because when a user in the structure performs dimming to perform a task in that room of the structure, the user will prefer to maintain a higher color temperature associated with midday time. Nevertheless, users also prefer to achieve greater color temperature reduction during, for example, morning or evening hours, because during those times the color temperature is already close to the warm white color spectrum and further dimming to complete the task does not adversely affect the user's perception of daylight simulation of outdoor daylight already in the lower color temperature trajectory. Historically, users have become accustomed to using incandescent lamps at about 2700K, which drops to 1500K when dimmed. However, high color temperature lighting devices, such as fluorescent or LED lighting devices, do not significantly change color temperature when dimmed. Thus, the objective for more LED dimming in the morning and evening is generally opposite to conventional LED lighting operation, but is ideally achieved by the present manual override, which will also maintain the less LED dimming conventionally desired when higher color temperatures are achieved.
Therefore, according to one embodiment, it is preferable that the driving current to each of the plurality of LED chains is automatically changed with time of day to change the color temperature output from the LEDs, thereby simulating the light of the natural daytime when the sun rises from the sun to the sun falls. According to another embodiment, the interface allows wired or wireless communication from a timer within a remote control remote from the lighting device, although the drive current to each of the plurality of LED chains is automatically changed depending on the timer output related to the position of the sun. The remote control, remote from the lighting device, also allows a trigger for the user to actuate the trigger and change the intensity value sent to the interface. The dim or reverse dim trigger button slider may be configured on a triac-based dimmer or remote from the lighting fixture and coupled to the AC mains. Actuation not only changes the intensity value, but correspondingly changes the same amount of brightness across all LEDs within one or more groups of luminaires controlled by the toggle button. However, depending on the time of day, when LEDs typically produce a lower color temperature, the brightness changes effected by changing the intensity values preferably have a greater effect than when they produce a higher color temperature. Although the change in brightness is the same, the benefit of the different effects on color temperature stems from the human perception of simulated daylight, as described above, the motivation is to keep the user at a higher color temperature during peak daylight hours than during off-peak times when the user would expect a lower color temperature. That adjustment is made whenever the user desires to dim from a higher brightness to a lower brightness to perform certain tasks, while maintaining a higher color temperature during peak daylight hours and more significantly reducing the color temperature during off-peak daylight hours.
According to yet another embodiment, a lighting system is provided. The illumination system may include a plurality of LEDs configured to produce a plurality of color temperatures along a black body curve. A timer may also be provided for generating a plurality of times of day including a first time of day and a second time of day. A drive circuit may be coupled between the timer and the plurality of LEDs to receive a plurality of times of day and assign drive currents to the plurality of LEDs to produce a first color temperature during a first time of day and a second color temperature during a second time of day. The driver circuit automatically and dynamically generates the first and second color temperatures depending on when the timer generates the first time of day signal and the second time of day signal. However, the dynamic and automatic generation of the first color temperature and the second color temperature may be overridden by user actuation of the trigger. The control module, and in particular an interface coupled to the control module, may receive the intensity values from a remote control or a dimmer and may send corresponding brightness values to each of the plurality of LEDs. The luminance value is determined based on a non-linear first mapping of intensity values to luminance values. That non-linear first mapping may be stored in the storage medium together with a second mapping of the color temperature as a function of time of day. The storage medium, specifically the first mapping and the second mapping, is used by the controller. When the controller receives a change in intensity value from the remote control or dimmer, the controller retrieves the first and second maps from the storage medium and may generate a greater change in color temperature during the first time of day than during the second time of day even if the change in brightness caused by the change in intensity value is equal at both the first time of day and the second time of day.
For example, the timer in the remote control is preferably any module, circuit or system having a clock. The clock preferably varies depending on the position of the earth relative to the structure in which the timer is placed. The clock may be coupled to any synchronous system, such as a crystal oscillator, or may receive a periodic feed from, for example, a satellite or over the internet. Also, the clock may preferably be reset based on the latitude and vertical coordinates of the timer and the particular time zone in which the timer is located. The timer generates times of day at any interval desired by the user, such as every minute, hour, or several hours. Thus, if the regular timing interval is set to every hour, then the times of day may include the day, e.g., starting at 6 am, 7 am, 8 am, etc. Alternatively, the timer generates the time signal only at selected times, such as sunrise, one hour after sunrise, sunset, and/or one hour before sunset. In the latter example, the timer may be generated at relatively short intervals (e.g., 10 minute intervals) over a fixed period of time (e.g., one hour) to produce a smoothing or "fade-in" effect as the color temperature changes after each sunrise and before sunset. Thus, for the viewer, the color temperature will change in a series of increasing or decreasing steps or linearly to increase or decrease the display of the automatic color temperature change.
As with the timer, which is preferably configured in a remote control (i.e., a physical keypad, or a portable computing device that is coupled, wired or wirelessly, to one or more groups of luminaires), the AC mains-coupled dimmer is also configured to be remote from the luminaires. A remote control or dimmer changes the brightness value manually, non-linearly, depending on the time of day, changing the color temperature by different amounts. However, the change in intensity value output from the dimmer changes the brightness value equally among the LEDs, changing the color temperature by equal or different amounts depending on the time of day. For example, the dimmer may include a trigger that, when actuated by a user, changes the color temperature more before 10 am and after 4 pm than between 10 am and 4 pm. Also, when actuated by a user, movement of the trigger over the dimmer may record a change in the corresponding intensity value, and correspondingly record a change in the brightness value. The color temperature is preferably reduced more before 10 am and after 4 pm than between 10 am and 4 pm. More preferably, the color temperature is reduced more by one or two hours after sunrise and one or two hours before sunset than during the middle period between sunrise and sunset. Those times are local times relative to the geographical location of the structure containing the lighting devices.
According to yet another preferred embodiment, the plurality of LEDs may comprise a first plurality of LEDs. The second plurality of LEDs may be grouped with the first plurality of LEDs within the room of the structure. Thus, two or more LED-based lighting devices may be grouped together within a room of a structure. Those lighting may be a set of down lamp PAR lighting installed in the ceiling and/or one or more of a20 lighting or a19 lighting, for example, lamps placed on a nightstand. Regardless of the type of lighting device or its functionality, the lighting devices may be grouped with each other for control purposes. However, typically, for example, a group of lighting devices are generally arranged in close geographical proximity to each other within one room of the structure. Thus, preferably according to some embodiments, the grouped plurality of lighting devices may be configured to produce the same color temperature between all lighting devices within the group. The color temperature between the grouped plurality of luminaires is set by a data set stored as content within each of the grouped plurality of luminaires. For example, the content of the data set is configured and then stored in the grouped lighting devices using the remote control. Thus, the remote control may not only discover all lighting devices within the structure, but may thereafter group certain groups of lighting devices, but may also assign the content of the data set defining the chromaticity and luminance values of each lighting device within the group. Thereafter, when the timer invokes a time-based display, such as an automatic fade-in of color temperature change, a periodic time-of-day signal is sent to a specifically grouped group of lighting devices. This causes all lighting devices within that group to experience an automatic change in color temperature, and possibly also an automatic change in luminance output, throughout the day. Thus, a preferred method includes automatically changing the color temperature between the grouped plurality of lighting devices based on a periodic, different time of day signal sent from a timer remote from the grouped plurality of lighting devices to simulate changing natural light produced by the sun.
The preferred lighting method further comprises manually dimming the brightness between the grouped plurality of luminaires, thereby causing the color temperature to change with the current time of day signal sent from the timer. In particular, if manual dimming occurs at a first time of day (i.e., at a current time of day signal at the first time of day), the color temperature may change more than when manual dimming occurs at a second time of day (i.e., at a current time of day signal at the second time of day). Manual dimming may maintain an override state in which it terminates the automatic change in color temperature or increases/decreases the automatic change in color temperature until the timeout timer ends, a predetermined time of day signal subsequently occurs, or possibly the next predetermined time of day signal subsequently occurs. The override state may be maintained indefinitely, or for a specific predetermined amount of time. Moreover, manual override, and in particular intensity change of dimming or reverse dimming levels, may occur gradually, linearly, exponentially, or in any user desired dimming or reverse dimming gradient, based on multiple steps, over a fixed or varying amount of time, to gradually fade into the automatically changing color temperature change. Details thereof, including details of each of the above-described embodiments, are further described below.
Detailed Description
Among the various advantages of LED-based lighting devices, LEDs provide a unique opportunity to integrate artificial light with natural light, and provide beneficial and healthy lighting through dynamic lighting mechanisms. One particular advantage of LED-based lighting devices is the generation of artificial sunlight for various reasons, in particular for the treatment of human diseases such as circadian rhythm disorders, seasonal diseases, shift work condition disorders, etc. Many conventional LED-based lighting devices replicate or "simulate" natural daylight conditions by using sensors. The sensor may detect daylight conditions within the interior structure of the structure and create artificial lighting from the lighting devices that attempt to replicate natural daylight conditions or simulate daylight outside the structure. Unfortunately, sensors have limitations both in technology and in the location of the sensors. Therefore, the sensor does not always accurately detect the external daylight condition, and sometimes fails to correctly simulate the outdoor natural daylight condition.
Thus, another, more preferred alternative mechanism is to keep track of the time of day and send multiple time of day values from the timer to the LED based lighting device. Instead of using a sensor, which has various drawbacks associated with it, a timer is used, and the simulated daylight changes based on the time of day value or data sent from the timer. The use of timers and time of day values proves beneficial if the day and night display is customized differently depending on the room in which the daylight is simulated. The sensors cannot customize the simulation depending on the room, but rather sense and provide a consistent simulation throughout the structure. Thus, grouping lighting devices on a room-by-room basis and controlling each room separately using different remote controls and associated timers with different time of day values is inherent to the timers rather than the sensors-the additional benefit of not using sensors to control daylight simulation. Of course, the use of a timer has acceptable limitations with respect to the sensor. The timer changes the time of day value sent to the lighting device to update the lighting device output at periodic intervals throughout the day, regardless of whether external conditions have changed, except for normal conditions occurring during that time of day. For example, unless a timer is coupled to the sensor, and the sensor is preferably placed outside the structure and communicatively linked to the timer, the timer itself cannot detect cloudy external conditions, partially cloudy, foggy, or rainy conditions. Thus, the communication of the timer and the plurality of time of day values or data transmitted from the timer of the remote control lighting device is limited to normal daylight conditions expected during the various times of the day. Simulating daylight with a timer is associated with statistically normal daylight conditions in some cases, but can be customized depending on the direction of the room toward daylight conditions. The benefit of selectively customizing the simulation depending on the group of lighting devices being controlled and the orientation of the room containing the devices outweighs any benefit of using sensors rather than timers. Individual control and customization among groups of lighting devices on a room-by-room basis has proven to be a superior control mechanism over sensors on most days of the year. The timer determines that any deviation of the conditions of the daylight simulation from what actually occurs outside at normal times of the day is an acceptable deviation and does not interfere with the benefits of the daylight simulation performed by the timer and the custom timer control between rooms within the structure. The use of only a timer and no sensor may also prove sufficient simply from the ease of operation of the timer rather than inaccurate and often defective sensor readings for sensing abnormal external daylight conditions. However, if the resulting analog display is unacceptable to the user, the user may manually change the color temperature output at any time, as described below.
According to one embodiment, daylight conditions are preferably simulated by using a timer that manipulates and updates the simulation from the lighting device based on the calendar day and time of day, and this function is performed automatically and dynamically throughout the day. The automatic simulation occurs as a dynamically changing display that automatically continues without user intervention, and in particular continues to change the color temperature output in response to the lighting device receiving a time of day signal sent from a timer. Automatic simulation and automatic change of color temperature occurs without user actuation of a trigger, functionally reserved for manual override rather than automatic display. Thereafter, depending on the task desired by the user, or if the user wishes to manually change the simulation to be more accurate with respect to what is occurring outside the structure, the user may manually change the color temperature output from the luminaire or specific group of luminaires, either in a single step in response to user actuation, or gradually in smooth steps or linearly over time. The return to automatically and dynamically changing the analog output may occur in smooth multiple steps or the same reversal that occurs linearly over time after the task is completed or after the user actuates the dimmer back to its previous trigger position or after a daylight analog change occurs at the next time of day or at the next time of day.
Fig. 3 illustrates in more detail the daylight trajectory and spectral characteristics of daylight similar to those shown in fig. 1 and 2, resulting from a change in position of the sun 16 relative to, for example, the structure 18 carrying one or more lighting devices. As shown in FIG. 3, the angular relationship between the sun 16 and the structure 18 changes throughout the day, where the angular relationship is often referred to as the zenith angleThe Path Length (PL) is from PL when the sun 16 moves from a top position to a position nearly horizontal to the Earth's surface 201 Increase to PL4 . Importantly, the spectral distribution of sunlight, and in particular the spectral radiance of sunlight, varies with PL. As shown in fig. 4, shorter wavelengths may be more sensitive and produce greater spectral radiation at shorter PLs than longer wavelengths. The combination of fig. 3 and 4 illustrates a shorter Path Length (PL) when the sun 16 is directly above the structure 181 ) Produce a greater amount of lower wavelength chromaticity spectrum and a longer Path Length (PL) as the sun 16 approaches the horizon4 ) Showing the advantages of longer wavelength spectral radiation. At PL1 Natural daylight conditions are usually more of a cool white or natural daylight color temperature, where blue dominates over red and yellow. Conversely, as path length increases to PL4 The color temperature is closer to the warm white associated with incandescent or halogen lamps, where red and yellow dominate over blue. In order to simulate an artificial lighting system (Such as one or more of the lighting devices of the present invention), the lighting device must be based on, for example, the changed Path Length (PL)s ) The color temperature output is changed throughout the day.
Fig. 5 partially illustrates a "white" LED lighting device 24. The illumination device constitutes white illumination by including, for example, a plurality of white LED semiconductor devices 26, a plurality of yellow-green semiconductor devices 28, a plurality of red LED semiconductor devices 30, and a blue LED semiconductor device 32 if the illumination device 24 is an RGB-based illumination device. The red, green, blue and white semiconductor devices are each defined in a particular chromaticity region of the chromaticity space that includes a target chromaticity region of combined light emitted by the red, green, blue and white light emitters. For example, an RGB system may form white light of a particular color temperature depending on the mix of various red, green, and blue chromaticity regions. Red, green, blue and white semiconductor devices are made of various organic or inorganic semiconductor materials, each of which produces a different chromaticity or wavelength output. Some red, green, blue or white semiconductor devices may be encapsulated with a coating to also produce a desired chromaticity wavelength output. For example, the white LED semiconductor device may comprise a blue light emitting LED semiconductor device coated with a phosphor. Also, by independently attenuating each of the three or four RGB or RGBW LEDs (or LED chains), the luminaire 24 is able to produce a wide color gamut with a color temperature along the blackbody curve and according to the desired output along the daylight trajectory.
Fig. 6 illustrates an example of a structure 36 containing a plurality of lighting devices 38. The lighting device 38 is sometimes interchangeably referred to simply as a lamp, lighting fixture, or luminaire. Residence 36 may have multiple rooms, such as bedrooms, living rooms, and so on. Preferably, each lighting device comprises at least one LED, and more preferably several LED chains, wherein each chain can produce a respective color within the chromaticity region. The lighting 38 can include PAR lighting, shown as a down light 38a in, for example, a living room, and other PAR lighting 38c, such as a down light in a bedroom. For example, a living room may have four downlights labeled 38a, while a bedroom may have three downlights labeled 38 c. Next to a sofa, for example, in a living room, is a table on which, for example, an a20 lighting device 38b is arranged.
Preferably, each lighting device comprises a communication interface for a first communication protocol, which is a wireless communication protocol used by, for example, all lighting devices 38 within the residence 36. A popular first communication protocol may be WPAN using IEEE 802.15.4 and/or any protocol based thereon, such as ZigBee. Thus, if desired, the lighting devices may communicate wirelessly with each other. In addition to wirelessly interconnected lighting devices, the remote control may also be interconnected wirelessly or by wire. The remote controls shown in fig. 6 may be physical keypads 40a and 40b associated with, for example, a living room and a bedroom, respectively. As will be mentioned later, the physical keypad may be replaced by a virtual keypad and assigned to, for example, a mobile phone, and in particular to a GUI displayed on a mobile phone or mobile computer. Thus, the remote control may be a physical keypad wired or wirelessly connected to one or more sets of physical lighting devices controlled by the physical keypad, or the remote control may be a computer-based portable device wirelessly connected to one or more sets of lighting devices controlled by a virtual keypad shown on a GUI of the wireless portable device. The virtual keypad displayed on the GUI of the mobile device may look exactly the same as the physical keypad, with virtual triggers (i.e., buttons, sliders, etc.) that are similar to the actual triggers on the physical keypad. The physical keypad may communicate with its corresponding lighting device by wire or wirelessly, while the virtual keypad displayed on the GUI of the mobile device may communicate using a wireless communication protocol, such as WPAN or ZigBee. Also, in contrast to the first communication protocol in which the physical lights and physical keypad 40 in the lighting device 38 communicate, the second communication protocol is linked to the first communication protocol via the bridge 42, the bridge 42 may be placed near a residence, and the residence 36 may allow the second communication protocol, such as ethernet, wiFi, bluetooth, etc., to communicate from, for example, a mobile phone to the lighting device 38.
Fig. 7 illustrates an exemplary block diagram of a lighting device 38 according to one embodiment of the present invention. The lighting device shown in fig. 7 provides one example of hardware and/or software that may be used to implement a method of dynamically and automatically simulating natural daylight, and thereafter manually overriding the simulation when one or more lighting tasks are required. Manual overrides may be required to perform temporary tasks or to more accurately simulate current external daylight conditions-e.g., changing from cloudy, sunny external daylight conditions to cloudy or rainy conditions.
The physical lighting device 38 comprises a plurality of emitting LEDs 40, and in this example, the physical lighting device 38 comprises a four-chain of any number of series-connected LEDs. Each chain may have two to four LEDs of the same color coupled in series and configured to receive the same drive current. In one example, the emitting LEDs 40 may include a red LED chain, a green LED chain, a blue LED chain, and a white or yellow LED chain. However, the preferred embodiments are not limited to any particular number of LED chains, any particular number of LEDs within each chain, or any particular color or combination of LED colors. In some embodiments, the emitting LED 40 may be mounted on a substrate and packaged within the primary optics structure of the emitter module, possibly together with one or more photodetectors.
In addition to the emitting LEDs 40, the lighting device 38 also includes various hardware and software components for powering the lighting device and controlling the light output from the one or more emitter modules. In the embodiment shown in fig. 7, the lighting device 38 is connected to the AC mains 42 and comprises a converter for converting the AC mains voltage (e.g. 120V or 240V) to a DC voltage (V)DC ) The AC/DC converter 44. The DC voltage (e.g., 15V) is supplied to the LED drive circuit 46 to generate a drive current that is supplied to the emitting LEDs 40 to produce illumination. In the embodiment of fig. 7, a DC/DC converter 48 is included for converting the DC voltage (V)DC ) Conversion to a lower voltage VL (e.g., 3.3V), the voltage VL Is used to power the lower voltage circuitry of the lighting device, such as Phase Locked Loop (PLL) 50, interface 52 and control circuitry 54. In other embodiments, the lighting device 38 may be powered by a DC voltage source (e.g., a battery) instead of the AC mains 42. In such embodiments, the lighting device may be coupled to a DC voltage sourceAnd may or may not include a DC/DC converter in place of the AC/DC converter 44. Additional timing circuitry may be required to provide timing and synchronization signals to the control drive circuitry.
In the illustrated embodiment, a PLL 50 is included within the illumination device 38 for providing timing and synchronization signals. PLL 50 may lock to the AC mains frequency and may generate a high speed Clock (CLK) signal and a synchronization Signal (SYNC). The CLK signal provides timing signals for the control circuit 54 and the LED driver circuit 46. In one example, the CLK signal frequency is in the tens of MHz range (e.g., 23 MHz) and is precisely frequency and phase synchronized to the AC mains. The SYNC signal is used by the control circuit 54 to create a timing signal for controlling the LED driver circuit 46. In one example, the SYNC signal frequency is equal to the AC mains frequency (e.g., 50 or 60 Hz) and is also precisely phase aligned with the AC mains.
In some embodiments, an interface 52 may be included within the lighting device 38 for receiving data sets or content from an external calibration tool during device manufacturing or during provisioning or commissioning of the lighting device or group of lighting devices. For example, the data set or content received via the interface 52 may be stored in a mapping table within the storage medium 56 of the control circuit 54. Examples of data sets or content that may be received via interface 52 include, but are not limited to, luminous flux (i.e., luminance value), intensity, wavelength, chromaticity of light emitted by each LED chain (i.e., which when mixed form a color temperature), more specifically, (a) a mapping of luminance values to intensity values, and (b) a mapping of color temperature to luminance values and time of day values, as will be described in more detail below.
The interface 52 is not limited to receiving data sets or content during provisioning or commissioning of a lighting device or group of lighting devices. The interface 54 may also be used to receive commands from, for example, a remote control 64. Commands may also be sent from the dimmer 52 to the control circuit (controller) 54. The dimmer 62 may be coupled to the AC mains, as shown, similar to a triac, to allow a user to manually operate the dimmer. The triac of dimmer 62 changes the phase-cut rms voltage on the AC mains and forwards the corresponding intensity value derived therefrom into the lighting device. Dimming or reverse dimming commands in the form of intensity values may be sent to the driver circuit 46 by actuating a trigger button or slider on the remote control 64 or the dimmer 62. Instead of actuating a trigger on the dimmer 52, a user may actuate a trigger (i.e., a button or slider) on a user interface of a remote control (such as a physical keypad) or a graphical user interface of a portable computer (such as a smartphone or laptop) to allow a dimming or reverse dimming command to be sent from the remote control 64 via the interface 52, either wired or wirelessly. Via the dimmer 62 or the remote control 64, a decrease in intensity values due to dimming (or an increase in intensity values due to reverse dimming) will cause a decrease/increase in brightness due to the mapping table stored in the medium 56 and retrieved by the control circuit controller 54. For example, commands may be communicated to the lighting 38 via the dimmer 62 or remote control 64 and interface 52 to turn the lighting on/off, control the brightness level, and manually and temporarily override the color temperature daylight simulation display (day or night) as described below, while performing tasks or while performing more accurate color temperature simulations of actual daylight conditions (e.g., cloudy, rainy, or cloudy outdoor conditions).
The interface 52 is not limited to receiving data sets or content during provisioning or commissioning of a lighting device or group of lighting devices. The interface 54 may also be used to receive commands from, for example, a remote control 64. Commands may also be sent from the dimmer 62 to the control circuit (controller) 54. The dimmer 62 may be coupled to the AC mains, as shown, similar to a triac, to allow a user to manually operate the dimmer. The triac of dimmer 62 changes the phase-cut rms voltage on the AC mains and relays the corresponding intensity values derived therefrom into the lighting device. Dimming or reverse dimming commands in the form of intensity values may be sent to the driver circuit 46 by actuating a trigger button or slider on the remote control 64 or the dimmer 62. Rather than actuating a trigger on the dimmer 62, a user may actuate a trigger (i.e., a button or slider) on a user interface of a remote control (such as a physical keypad) or a graphical user interface of a portable computer (such as a smartphone or laptop) to allow a dimming or reverse dimming command to be sent from the remote control 64 via the interface 52, either wired or wirelessly. Via the dimmer 62 or the remote control 64, a decrease in intensity values due to dimming (or an increase in intensity values due to reverse dimming) will cause a decrease/increase in brightness due to the mapping table stored in the medium 56 and retrieved by the control circuit controller 54. For example, commands may be transmitted to the lighting fixture 38 via the dimmer 62 or remote controller 64 and interface 52 to turn the lighting fixture on/off, control the brightness level, and manually and temporarily override the color temperature daylight simulation display (day or night) as described below, while performing tasks or while performing more accurate color temperature simulations of actual daylight conditions (e.g., cloudy, rainy, or cloudy outdoor conditions).
According to a preferred embodiment, the interface 52 is coupled for receiving control signals from the remote control 64, and in particular for receiving control signals from a user actuating a trigger on the remote control 64, for altering the automatically changing lighting display between one or more sets of lighting devices 38. In accordance with the automatically changing lighting display, the remote control 64 may include a timer that sends a plurality of time of day signals to the control circuit controller 54 via the interface 52. For example, if the remote control 64 includes a physical keypad 40 having a real-time clock therein, the real-time clock periodically transmits a time of day signal among a plurality of time of day signals depending on the calendar day and the time of day. The time of day signal is unique to the calendar day and the time of day recorded and output by the timer. If, for example, a time of day signal is transmitted every hour, only the specific time of day signal for the current hour is transmitted from among the time of day signals, where each signal corresponds to a different hour.
Using the timing signals received from PLL 50 and control signals from interface 52 (e.g., a periodic set of time of day signals sent from a remote timer to create a display that simulates daylight changes over time of day, and a dimmer that performs a dimming function to change the intensity values to desired brightness levels), control circuit controller 54 controls the display based on brightness and color temperature as a function of brightness and time stored in medium 56The map calculates and generates a value indicative of the desired drive current to be provided to each LED chain 40. This information may be passed through a compliance standard (such as SPI or I)2 C) From the control circuit controller 54 to the LED driver circuit 40. In addition, the control circuit 54 may provide a latch signal that instructs the LED drive circuit 46 to simultaneously vary the drive current provided to each LED chain 40 to prevent brightness and color artifacts.
In some embodiments, controller 54 may be configured to operate in accordance with U.S. patent application serial No.14/314,530, published as U.S. publication No.2015/0382422A1, on 31/12/2015; U.S. Pat. No.14/314,580, issued on U.S. Pat. No.9,392,663, 2016, 7, 12; and 2016, 3/3 as one or more compensation methods described in U.S. publication No.14/471,081, published as U.S. publication No.2016/0066384A1, determines the respective drive currents required to achieve a desired luminous flux and/or a desired chromaticity of a lighting device, which are commonly assigned and incorporated herein in their entirety. In a preferred embodiment, the control circuit controller 54 may also be configured to adjust the drive current provided to the emitting LEDs 40 so as not to exceed a maximum safe current level or a maximum safe power level due to the one or more power converters of the lighting device 38 at the current operating temperature determined by the temperature sensor 58.
As shown in fig. 7, a temperature sensor 58 may be included within the lighting device 38 for measuring the current operating temperature of the lighting device. In some embodiments, the temperature sensor 58 may be a thermistor that is thermally coupled to a circuit board or chip that includes one or more of the components shown in fig. 7. For example, the temperature sensor 58 may be coupled to a circuit board that includes the AC/DC converter 44, the DC/DC converter 48, the PLL 50, and the interface 52. In another example, the temperature sensor 58 may be thermally coupled to a chip that includes the LED driver circuit 46 and the emitting LED chain 40. In other embodiments, the temperature sensor 58 may be an LED that functions as both a temperature sensor and an optical sensor to measure ambient light conditions or output characteristics of the LED chain 40. The temperature measured by the sensor 58 is provided to the controller 54 for adjusting the drive current.
In some embodiments, control circuit controller 54 may determine the corresponding drive current by executing program instructions stored in storage medium 56. In one embodiment, the storage medium 56 storing the first and second mappings may be a non-volatile memory and may be configured to store program instructions and a table of calibration values as described, for example, in U.S. patent application Ser. No.14/314,451 published 31/12/2015 as U.S. publication No.2015/0377699A1 and 14/471,057 published 31/12/2015 as U.S. patent No.9,392,660, which are commonly assigned and incorporated herein in their entirety. Alternatively, control circuit controller 54 may include combinatorial logic for determining the desired drive current, and storage medium 56 may be used only to store a map of color temperature as a function of luminance value and time of day, and intensity as a function of luminance value.
In general, the LED driver circuit 46 may include a number (N) of driver blocks 68, N being equal to the number of emitting LED chains 40 included within the lighting device 38. In one exemplary embodiment, the LED driver circuit 46 includes four driver blocks 68, each configured to produce illumination from a different one of the emitting LED chains 40. In some embodiments, the LED drive circuit 46 may include circuitry for measuring ambient temperature, measuring the photodetector and/or emitter forward voltage and photocurrent, and adjusting the LED drive current. Each driver block 68 receives data indicating a desired drive current from the control circuit 54 and a latch signal indicating when the driver block 68 should change the drive current.
Fig. 8 is an exemplary block diagram of the LED driver circuit 46 according to one embodiment of the invention. In the exemplary embodiment of fig. 8, the LED driver circuit 46 includes four driver blocks 68, each block including a DC/DC converter 72, a current source 74 and an LC filter 76 for generating an operating drive current (Idrv) that is supplied to the connected emitting LED chain 40a to produce illumination, and a relatively small drive current (Idrv) for obtaining a measurement of the emitter forward voltage (Vfe). In some embodiments, DC/DC converter 72 may drive a DC voltage (V) when controller 80 drives the "Out _ En" signal highDC ) Conversion to Pulse Width Modulated (PWM) voltageAnd (Vdr) is output. This PWM voltage signal (Vdr) is filtered by the LC filter 76 to produce a forward voltage on the anode of the connected LED chain 40 a. The cathode of the LED chain is connected to a current source 74 which forces the fixed drive current (Idrv) to be equal to the value provided by the "emitter current" signal through the LED chain 40a when the "LED _ On" signal is high. The "Vc" signal from current source 74 provides feedback to DC/DC converter 72 to output the appropriate duty cycle and minimize the voltage drop across current source 74.
As shown in fig. 8, each driver block 30 may also include a differential amplifier 78 for measuring the forward voltage drop (Vfe) across the connected emitting LED chain 26 a. When Vfe is measured, DC/DC converter 32 is turned off, and current source 74 is configured to draw a relatively small drive current (e.g., about 1 mA) through the connected emitting LED chain 40 a. The forward voltage drop (Vfe) produced across LED chain 40a by this current is measured by a differential amplifier 78, which produces a signal equal to Vfe. The forward voltage (Vfe) is converted to a digital signal by an analog-to-digital converter (ADC) 42 and provided to the controller 80. The second controller 80 determines when to make a forward voltage measurement and generates Out _ En, emitter Current (Emitter Current), and Led _ On signals, which are provided to each driver block 68.
The LED driver circuit 46 is not limited to the embodiment shown in fig. 8. In some embodiments, each LED driver block 68 may include additional circuitry for measuring photocurrent induced across one or more of the emitting LED chains 40 when those chains are configured to detect incident light (e.g., ambient light or light emitted from other emitting LEDs). In some embodiments, the LED driver circuit 46 may additionally include one or more receiver blocks (not shown) for measuring the forward voltage and/or photocurrent induced across one or more photodetectors, which may also be included in the transmitter module. In some embodiments, the LED driver circuit 46 may include a temperature sensor for measuring the temperature of the driver circuit and a multiplexer for multiplexing the transmitter forward voltage (Vfe) and the measured temperature to the ADC 82. Exemplary embodiments of such a drive circuit are described in the aforementioned co-pending application.
DC/DC converters 48 and 72 may include substantially any type of DC/DC power converter, including, but not limited to, buck converters, boost converters, buck-boost converters,A converter, a single-ended primary inductor converter (SEPIC), or a flyback converter. The AC/DC converter 44 may likewise comprise substantially any type of AC/DC power converter, including but not limited to buck converters, boost converters, buck-boost converters,A converter, a single-ended primary inductor converter (SEPIC), or a flyback converter, etc. Each of these power converters generally includes a plurality of inductors (or transformers) for storing energy received from an input voltage source, a plurality of capacitors for supplying energy to a load, and switches for controlling the transfer of energy between the input voltage source and the load. Depending on the type of power converter used, the output voltage supplied by the power converter to the load may be greater or less than the input voltage source.
According to a preferred embodiment, AC/DC converter 44 comprises a flyback converter, while DC/DC converter 48 and DC/DC converter 72 comprise buck converters. The AC/DC converter 44 converts AC mains power (e.g., 120V or 240V) to a substantially lower DC voltage VDC (e.g., 15V) which is provided to the buck converter 48/72. The buck converters 48/72 step down the DC voltage output from the AC/DC converter 44 to a lower voltage that is used to power the low voltage circuitry and provide drive current to the LED chain 40.
In some embodiments, the brightness level may be adjusted substantially continuously from the dimmer 62 or the remote 64 between a minimum level (e.g., 0% brightness) and a maximum level (e.g., 100% brightness), or vice versa. The adjustment may be linear, but in most cases is non-linear and more of a logarithmic scale due to differences in dimmer and slider adjustments on the remote 64 with respect to brightness output, as shown and described in fig. 12. Specifically, movement of the trigger position (movement of the slider, amount of time to press a button, or whether one or more buttons are pressed) translates into an intensity value. The location of the trigger location may correspond to the intensity value, but the trigger location/state or intensity value is non-linear with respect to the brightness level. Thus, actuation of the trigger does not translate into an exact "one-to-one" change in brightness level. A non-linear mapping is required. By defining the brightness level as a 16-bit variable, scaling can be easily achieved. In other embodiments, the brightness level may be adjusted between a finite number of predefined steps, where each step corresponds to a percentage change in brightness (e.g., 0%, 25%, 50%, 75%, or 100% maximum brightness) or a decibel change in lumen output (e.g., +/-1 dB).
Fig. 9 illustrates an example of grouping actual physical lighting devices 38 based on their location and function. When describing the grouping mechanism and the scene/display assignment mechanism, a mechanism for providing the grouping and the functions of the lighting devices will be disclosed later. However, as shown in fig. 9, a location such as a bedroom may have a set of lights 38, and associated with the set of lights 38 is a particular scene or display. Since each luminaire 38 has one or more LEDs, the RGB of the multiple LEDs can be customized to any color, brightness, or visual effect desired by the user by setting up a scene or time-varying display within the grouped luminaires.
Fig. 9 illustrates a plurality of physical lighting devices displayed as virtual lighting devices on a graphical user interface of the remote control 64, and in particular on the GUI 85 of the remote control 64. The virtual lighting devices 39 correspond to the respective actual lighting devices 38 within the structure. In addition to the physical lighting 38, there are physical keypads 40 spaced throughout the structure as shown in fig. 6. The lighting device 38 may have any type of form factor including a20, PAR38, linear grooves, wall wash lights, and track lights. The keypad 40 may be mounted in a signal combining junction box and coupled to an AC mains. Also, the virtual keypad appearing on the wireless or wired remote control 64 may eliminate the physical keypad 40. The virtual keypad may reside on a GUI application on a computer, in particular a mobile device such as a smartphone. If the remote control consists of a wired physical keypad or a wireless mobile device having a GUI with a virtual keypad shown thereon, the keypad (whether physical or virtual) is generally described as the remote control 64. In addition to the network of physical lighting devices 38 and physical keypads 40, the remote control 64 is also used to control communications with the network of physical lighting devices 38 and physical keypads 40. The remote control 64 is essentially an execution unit that executes instructions and data to present a GUI that a user may use to perform the grouping and scene/display assignments described in fig. 10b and 10 c. Control instructions are sent from the controller 64 to the network of lighting devices 38 via the communication interface. The communication interface for the controller 64 simply communicates properly with the lighting devices and keypad using, for example, the ZigBee communication protocol. The remote control 64 may also communicate via a different protocol if a bridge or hub is required to bridge between the ZigBee protocol for communication by the lighting devices 38 and the protocol used by the remote control 64. For example, a software application may operate on the controller 64, perhaps on an Apple (Apple) or Android (Android) mobile device, to present a virtual keypad on the controller 22. A hub or bridge connects between WiFi and a wireless light network that may use ZigBee. A dongle with a radio interface would allow the GUI of the remote control 64 to communicate directly with the network of physical lighting devices 38 and physical keypads 40 if the remote control 64 communicates directly without an intermediate bridge or hub.
A typical installation in a structure will have a physical keypad 40 and various physical lighting devices 38 in each room. In some cases, some rooms may have multiple keypads controlling the same lighting device as a conventional two-way or three-way light switch, where the three-way switch uses two switches and the two-way switch uses one switch, on/off. The physical keypad 40 in each room then generally controls color, brightness, spectrum, or visual effect. The keypad may control these effects statically or as a function of time. The static control is simply the user pressing a trigger button or slider on the physical keypad. The lighting device 38 and physical keypad 40 in the home may also be controlled by a computer running an application, with a radio-based dongle plugged into a USB port, or may be controlled by a mobile device (such as a smartphone also running a software application). For example, the dongle may transmit ZigBee messages directly, while the bridge or hub converts between WiFi and ZigBee messages.
After the physical lighting devices 38 and physical keypads 40 are installed in the structure, the physical lighting devices 38 and physical keypads 40 must be discovered prior to the grouping and scene building process. Thus, when using a controller with a dongle for example, the first step is to discover all lighting devices and keypads within range of the controller. The wireless network used by the lighting device 38 and keypad 40 is preferably a mesh network, so that physically remote lighting devices or keypads may still be within communication range of the controller by one or more hops (hops). When the user instructs the controller to discover all devices (which may be through commands on the controller's GUI), the dongle broadcasts a message instructing all devices to receive the message directly or over any number of hops to respond with their unique ID number (often referred to as a MAC address). The unique MAC address for each lighting device and keypad is sent back to the remote controller 64. If the remote control 64 is a personal computer or telephone with a screen, it displays a set of GUI icons on the screen as virtual lighting devices representing the corresponding physical lighting devices that have responded. These icons are referred to as virtual lighting devices because there is a need to distinguish between lighting devices appearing on the GUI as virtual lighting devices 39 and lighting devices existing in the home or physical lighting devices 38.
For example, as shown in fig. 9, in a facility with six PAR physical luminaires 38 in the structure, six virtual luminaire 39 icons will appear. The keypad will also be shown as a virtual keypad icon in a later step. When an acknowledgement message is sent back from each luminaire to the remote control, an indication occurs that all luminaires have been discovered, which causes each physical light to turn blue and each physical keypad to blink. Moreover, each discovered physical lighting device and physical keypad will appear on the GUI as a virtual lighting device and virtual keypad icon. If not all physical lighting devices turn blue or the keypad blinks when the user checks by walking around the house, not all acknowledgement messages have been returned, so a missing acknowledgement message for a unique MAC lamp address would indicate that a non-blue physical lamp has not been found. Remedial action then needs to be taken, as described below. However, if all physical lighting devices become blue upon physical inspection, the corresponding icon will appear, and all physical lighting devices within the home will appear as icons on the controller GUI.
After all physical lighting devices and physical keypads are discovered, the next step is grouping. In the grouping process or mechanism, physical lighting devices that need to be controlled together are assigned a specific group address. As shown in fig. 9, during the grouping mechanism, the group address is downloaded into the storage medium 56 of each lighting device. Thereafter, during a control mechanism, actuation of a single button of the physical keypad 40, or of the group name assigned to the virtual button of the virtual keypad, will cause a control message to be sent from the controller to all unique MAC addresses associated with that unique group address via a single multicast message to initiate content associated with that group of physical lighting devices via the microprocessor abstraction mechanism. Further description of the group addressing and storage of content within the lighting devices 38 occurs during the grouping mechanism as well as during the scene builder or display builder mechanism.
There may be different types of remote controls 64, particularly communication protocols that apply to multiple lighting fixtures 38. The remote control 64 may simply comprise a dongle with a USB interface and plugged into the USB port of the mobile device by radio. If the remote control 64 is to communicate through a hub or bridge, the remote control 64 communicates using different protocols, which are used by the various lighting devices 38 to communicate with each other and with the physical keypad 40.
For example, during the discovery phase, a broadcast discovery signal is sent from the remote controller 64 over the mesh network from hop to hop with an acknowledgement return (e.g., in hexadecimal) from, for example, the unique address to the unique address. The broadcast discovery and acknowledgement returns form a routing table with the destination address and next hop address for a particular lamp. The routing table is stored in the memory of the lighting device 38 together with a group address that we will describe later and the content associated with the group address. The group address and the content may have group addresses, e.g. F and C, respectively, forming a multicast table. Examples of lighting device discovery, multicast table formulation and content (scene/display builder) for groups of lighting devices and flow charts for each process are set forth in U.S. patent application serial No.15/041,166, commonly assigned and incorporated by reference herein in its entirety.
The discovery process may be initiated by sending a discovery message. At least once, after the lighting devices 38 are installed, network configuration may be required. This network configuration may be repeated if desired. Typically, the configuration or discovery process is performed only once. However, if the lighting device is replaced, the discovery process must be repeated at any time the lighting system is modified. Thus, the discovery process may be performed if the network is modified or reconfigured, if lighting devices are added or removed, or a modification of the lighting scene occurs. When the network is configured during the discovery phase, the remote control initially has no knowledge of the available lighting devices. The structure of the lighting system network is not predetermined by installation as is the wiring structure of a wired network. Instead, it may be determined by a number of physical conditions, such as the distance between adjacent lighting devices or shielding material, walls or other devices between lighting devices, or even by electromagnetic interference of appliances or other devices within the structure 36.
To calculate the network configuration, the broadcast is preferably triggered by the controller 64. The broadcast message is sent by addressing the message to a predefined broadcast address, which all physical devices (lighting devices and keypads) listen to. For example, the broadcast signal will first be received by those devices that are close to the controller. Those lighting devices may then forward the broadcast message to other lighting devices, which further forward the message to even further lighting devices via one or more hops. To complete the network configuration, the controller must receive an acknowledgement signal from each lamp, with which the lamp acknowledges that it has received the broadcast message. The acknowledgement signal is preferably sent back as a unicast or direct message to the controller sending the broadcast. Each lighting device that sends such a unicast message must receive an acknowledgement to prevent such a lighting device from resending the same message. Thus, the return acknowledgement is sent back by the controller through the mesh network, also as a unicast message.
Broadcasting, receiving and acknowledging back, and then sending an acknowledgement, during the discovery phase or process, is time consuming. However, since the discovery process does not occur often and generally only during configuration of the lighting device during initial installation, the user may generally accept a time-consuming discovery process that may take many seconds. However, any time delay or lag, in particular any popcorn effect, should be avoided when subsequently controlling the discovered lighting device. In some cases, even within a fraction of a second, it may be obviously annoying for the user when performing control using the multicast and aggregate acknowledgement mechanism described later.
Although relatively slow compared to the control process, the discovery process begins with broadcasting a discovery message, whereby the message may be routed over multiple hops to all of the various nodes, including the physical lighting devices 38 and the physical keypad 40. Unicast and acknowledgement returns to the remote control 64 for each of those nodes, keypads and lighting devices must be routed through the mesh network as acknowledgement signals, whereupon the remote control 64 receives an acknowledgement that it is expected to have a unique MAC address for all physical lighting devices through the physical keypad indicating the blue light output from all these lighting devices and the flashing of the keypad found.
Fig. 9 illustrates a grouping process in which the GUI on the remote controller 64 is used not only to group virtual lighting device 39 icons, but also any group of physical lighting devices 38 named based on the user or a pre-existing group having pre-existing scenes assigned to it. Fig. 9 illustrates a GUI displayed on the remote controller 64 if the remote controller 64 has a screen similar to a portable computer or a telephone. On this GUI, on the left hand portion of the GUI are icons representing either groups or keypads. When a group icon is selected, a series of groups A, B, C, etc. may appear as indicated. According to one embodiment, a series of group icons 90 appear. According to one embodiment, the group icon is not named until the user provides the name. Thus, for example, group a may be the name given to the group icon, or may simply be the default name given to the group icon. The group shown as an icon on the GUI of the remote control 64 may have a predefined name, such as a bedroom downlight or a bedroom bedside table (night stand). In the latter embodiment, those predefined names may also have predefined scenes or displays. For example, a bedroom downlight may have a predefined scene or display uniquely assigned to the downlight or to the lighting in the bedroom as content stored in that group of lighting. For example, the uniquely assigned scene/display is preferably different from the predetermined scene or display associated with the bedroom bedside cabinet group of the lighting device. As shown in fig. 9, after all lighting devices have been discovered and appear as virtual lighting devices 39 or icons in the right portion of the GUI 85, one or more lighting devices may be grouped by clicking on the virtual lighting device in the GUI, and the virtual lighting device icon 39 may flash or change to a different color. The corresponding physical lighting or lights 38 in, for example, the bedroom will also change color or flash as indicated by the physical lighting flashing corresponding to the virtual lighting 39 icon flashing. In this way, the user will know the correspondence between the virtual lighting device icons and the physical lighting devices, so that when he or she performs the grouping process, it is known which lighting device (virtual icon and physical) is assigned to each group, as shown in fig. 9, where the bedroom down lighting device 38 corresponding to virtual lighting device 39 is assigned to group a.
As an example, if there are three rooms with one keypad in each room (i.e., kitchen, living room, and bedroom), then in the bedroom there might be two a20 lights on the bedside cabinet and two PAR38 lights in the ceiling. The user may want to control the two groups of physical lighting independently in order to create two groups called bedroom downlights and bedroom bedside tables and these groups are displayed as another group name in group 90 of GUI 85. In a living room, there may be three a20 lighting and four PAR38 lighting. The user may want to create three named group icons 90, including one a20 on the end table next to the chair, two a20 on either end of the sofa, and four PARs 38 in the ceiling, thus creating three groups, called a life-down light, a life-end table-chair, and a life-end table sofa. The named group icons may be named by the user or may be predefined with predefined scenes and displays associated therewith. In a kitchen, there may be four PARs 38 in the ceiling that are controlled together, thus creating a group called kitchen-down light, or may be pre-existing with the associated scene/display.
Using the example above, there are six groups of virtual lighting icons on the left side of the GUI, ten PAR38 light icons (virtual lighting) and five a20 light icons (virtual lighting) on the right side of the GUI. All lamps are still blue. When a user clicks on a light icon, the corresponding physical light and its associated MAC address change color momentarily, as shown for example when clicking on the virtual lighting device icon. The user will enter, for example, a bedroom and will notice that the corresponding physical lighting device changes color or flashes, indicating its correspondence with the virtual lighting device. The user then drags and drops, for example, two virtual light icons into the left group named group a or "bedroom-bedside table". This process may continue for other groups, for example, the user may click on the PAR38 virtual light icons until two icons in the bedroom are identified, and then drag and drop those virtual light icons into a group named group B or "bedroom-down light," for example. For example, when a virtual light icon is placed in a group, the associated physical light changes back to its default light color. The user may perform the same grouping process in the living room, kitchen or the entire structure.
At this point, all virtual lighting device icons on the right side of the GUI disappear because they have been dragged and dropped, for example, into the corresponding group named group icon 90. Moreover, all physical lighting devices produce white light. The next step is to configure the physical keypad in each room. The configuration of the virtual keypad using, for example, a mobile phone control device will be described later. However, at present, the configuration of the physical keypad is described. In configuring the keypad, the user may click on a different tab, such as tab B, instead of tab A at the top of the GUI. By clicking on another tab associated with a keypad, the buttons on each keypad may be configured to produce specific brightness, color, spectral settings, and visual attribute settings for a specific group of lighting devices. The device control process of configuring specific buttons on a physical keypad is shown in more detail with reference to fig. 10a, 10b and 10 c.
For example, configuring a particular keypad begins by selecting the keypad, as shown in FIG. 10a, that is, selecting the virtual keypad icon 92 upon clicking on the keypad icon in the left portion of GUI 85. Once the virtual keypad icon 92 is identified, the keypad icon 92 may be assigned to one or more group icons 90 to be named or to a predefined named group icon. Thereafter, as shown in FIG. 10b, the GUI 85 changes its display and presents the virtual keypad 92 with the corresponding virtual trigger button 98. The virtual buttons 98 may be replaced by virtual sliders, all of which belong to the category of triggers. Five virtual buttons are shown, however, there may be more or fewer buttons as desired. A scene or display may be associated with the selected virtual scene/display icon 100 and dragged and dropped onto the corresponding trigger button 98. In this manner, each button on the virtual keypad 92 may operate as a trigger slider. The longer the button is pressed, the larger the slider position. Each trigger button may have associated controls for one or more groups of physical lighting devices 38 within the structure, as well as a corresponding scene or display for each of those groups assigned to the lighting devices 38 by downloading corresponding content to the physical lighting devices 38. The assignment of groups or scenes/displays may also be performed from drop-down menus rather than drag-and-drop techniques.
By way of example, if there are two buttons controlling the bedroom-downlight group and the bedroom-bedside cabinet group, then the top two buttons may control each of those groups. The user assigns a particular color temperature, brightness, or any visual attribute to each of the various buttons, and in this case, to the virtual buttons of the virtual keypad 92. For example, a bottom button may be assigned to all groups controlled by a corresponding physical keypad, and a bottom button may be assigned to turn off all lights associated with the respective groups attributable to that keypad. The process of grouping buttons into bedrooms may be repeated for the living room, kitchen, and all remaining physical keypads within the structure. The grouping is done by the virtual keypad configuration which then corresponds to the appropriate physical keypad. Select and assign a trigger button to a predefined or non-predefined group of lighting devices, and control the scenes and displays of those groups.
After programming the various virtual buttons of the virtual keypad displayed on the controller 64GUI, the corresponding group address and the assigned scenes and corresponding content of the display are downloaded from the virtual keypad 92 to the corresponding physical keypad 40 of fig. 1. The physical keypad 40 will operate exactly the same as the virtual keypad 92 in that touching any button corresponding to the five buttons on the virtual keypad will send a multicast control message to the physical lighting devices controlled by the physical keypad. Also, similar to identifying physical lighting devices when performing grouping of virtual light icons, the physical keypad 40 associated with virtual keypad 92 will blink when the virtual keypad is selected. For example, when a virtual keypad 92 is selected within the GUI of the controller 64, the corresponding physical keypad 40a, 40b, etc. will flash, indicating to the user which keypad within the structure has been selected.
As shown in fig. 10b, there are also up/down buttons 104 along with the five virtual buttons 98 of the virtual keypad 92. The up/down trigger button may be programmed in the virtual keypad 92 and have a corresponding similar programming effect in the physical keypad 40. For example, upon actuation of a corresponding button on the physical keypad 40 after programming using a virtual button on the GUI, the corresponding set of physical lighting devices is turned on. The physical keypad 40 or virtual keypad 92 may have buttons or touch lights corresponding to the virtual trigger slider up/down buttons 104 operable on the virtual keypad as well as on the physical keypad to adjust the brightness of the light controlled by the last button pressed on the physical/virtual keypad. For example, if the top button of a physical or virtual keypad associated with the bedroom sets the bedroom-down light to half brightness in red, then the up/down arrow will adjust the brightness of the bedroom-down light after the top button of the physical/virtual keypad is pressed. For example, after pressing another button associated with the bedroom bedside table group, the up/down arrow will control the brightness of the bedroom bedside table. When the up/down arrow is pressed, a message is sent to the group of physical luminaires associated with the keypad button using multicast addressing. Alternatively, the up/down trigger 104 may control all groups of lighting devices controllable by the keypad. For example, all groups associated with a virtual or physical keypad are dimmed or dimmed back together, not just the group controlled by the last button 98 pressed. Also, as described above, the trigger may include the button 98 or the up/down button 104. The duration of pressing of the button 98 operates as a trigger slider, or, for example, the appropriate up/down button 104 in the five groups may also operate as the last button 98 pressed or a trigger slider for all buttons 98 assigned to all lighting devices in the room or rooms controlled by those buttons 98.
According to one embodiment, the groups assigned to virtual buttons on the virtual keypad and thus to physical buttons on the physical keypad may also be assigned to predefined scenes or displays by using pull-down icons. The drop-down icon records the predefined scene or display applied to the group and its corresponding scene or display is applied, for example, to a virtual button on the virtual keypad 92 via the GUI of the controller 64, and that group, scene or display is then downloaded to the physical button on the corresponding physical keypad that is flashing to indicate that it is selected for programming. The physical keypad may interrupt the flashing that occurs in the discovery/configuration process after all buttons have been programmed with their corresponding predefined group names for the predefined scenes and displays, or according to another embodiment, after any user-defined and non-predefined group names or scenes and displays. Once the virtual keypad icon is dragged and dropped to the left side of the GUI screen, the user can enter the name of that keypad, e.g., "bedroom _1". To program the buttons on the virtual/physical keypad, the user selects the virtual keypad on the left side of the GUI screen 85, which is preferably pre-named as what the user can recognize.
According to one embodiment, the user may select the create scene or display button 106, as shown in FIG. 10b, if the scene and display are not predefined and assigned to a predefined group name, but are defined by the user to allow the button to present any possible, substantially unlimited number of scenes or displays. The corresponding GUI will then appear on the remote control 64, as shown in fig. 10 c. The GUI allows the user to manually control any color temperature, brightness, or visual attribute to be assigned by clicking on the manual control 108. The manual control may then bring up the blackbody curve 110 to allow the user to pick any color temperature along the blackbody curve 110, or manually select visual properties, color temperature (CCT), and/or brightness, etc. for each group using the slider 112. Also, the user may assign a time (in increments or times of day 114) for each attribute, color temperature, or brightness to produce an automatically changing color temperature for the display. The time can be programmed, for example, to be daytime, to automatically and dynamically change the color temperature throughout the day from sunrise to sunset. The display may also extend to sunset, to night. Depending on the display stored in the corresponding one or more groups of luminaires, the change in color temperature output from the one or more groups of luminaires assigned to the generated display is automatic. The change in color temperature may also be implemented as a series of scenes triggered by multiple time of day signals sent from a timer within the remote control (virtual keypad 92 or physical keypad 40). Thus, the remote control 64 includes a real time clock that generates a plurality of time of day signals based on the calendar day and the time of day during the day. Those time of day signals may be synchronized via connection to a crystal oscillator, via connection to the internet, or to a satellite. Depending on which of a plurality of time of day signals is transmitted, the color temperatures output from the corresponding group of luminaires respond via multicast signals transmitted to the grouped set of luminaire MAC addresses. Different time of day signals are sent at different times during the whole day to trigger different color temperatures output from the addressed group of luminaires. Thus, a user may program a bedroom group of lighting devices to operate simulated daylight different from, for example, a kitchen group of lighting devices. Even if the same time of day signal is sent to the bedroom and kitchen group (e.g., midday hours), the display stored in the bedroom lighting can produce a lower color temperature of 2300Kelvin, or be off, while the kitchen lighting can produce a higher color temperature of approximately 6000 Kelvin. Alternatively, the user may program the time of day signal at different times for the kitchen and the bedroom. For example, the sunrise time signal of a day may be earlier in the bedroom than in the kitchen. The remote control for the kitchen is separate from that for the bedroom and each programs a timer in a different manner, allowing the displays to be selectively modified and then each display to be selectively manually overridden.
Turning now to fig. 11, a graph of spectral sensitivity of luminance at different color wavelengths is shown. Although the power of the lighting devices of the various wavelengths is equal from a physical point of view, the sensitivity of the vision system to different wavelengths differs. For example, luminance or brightness can be expressed even if light of equal power should produce the same effect at all spectral wavelengths, in fact, not all wavelengths appear to be equally bright. Visual luminance is defined as L = c ═ P (λ) V (λ) d λ, where P is the spectral power and V is the photopic spectral sensitivity of a standard observer. As shown in fig. 11, luminance can be expressed as the fact that: lighting devices of the same power but different wavelengths do not appear as bright to a standard observer. Further details regarding the relationship between color temperature as a function of brightness and time of day will be described later with reference to fig. 15. However, according to one embodiment, it is sufficient to recognize that lower color temperatures are more affected by changes in brightness and time of day than higher color temperatures. However, according to another embodiment, an all-day variable luminance with the same change in luminance can produce the same change in color temperature all day long. FIG. 12 illustrates what happens when a remote control 64, such as a virtual/physical keypad, receives a user actuation on, for example, a trigger slider to produce a different intensity value that is sent to the interface 52. The intensity value corresponds to a trigger position value. The relation between the trigger position/state and the lumen output has the characteristics shown in fig. 12. The controller 54 converts the trigger/status position to lumen output and color temperature by table and interpolation. Those transfer functions are different at different times of the day. Once the desired lumen output and color temperature are known, the controller 54 calculates the drive current required for each LED chain. That value applied to all LED chains is the current or power value required to change the brightness output from all LED chains.
As shown in fig. 12, a change in slider movement is used to produce a change in intensity on the virtual/physical keypad or triac dimmer associated with the physical keypad, the resulting brightness will change in a non-linear manner. In other words, there is a non-linear relationship between the slider movement intensity output and the luminance output. Thus, the storage medium 56 contains a non-linear first mapping of intensity values to brightness values such that each incremental change in slider position on the virtual/physical keypad or dimmer will correspond to a brightness value according to the mapping along a series of points of the non-linear curve shown in fig. 12. The mapping or plot of the intensity versus brightness non-linear curve is generally referred to as a brightness dimming curve and is mapped to a first mapping within the storage medium. The resulting luminance output caused by the movement of the slider by the user is triggered, and then a first mapping is formulated using the gradual movement and the recording of the luminance output, which is then stored in storage medium 56 for subsequent use.
Fig. 13a and 13b illustrate what happens when the user actuates the trigger at different times of day, those times of day being times sent from a timer within, for example, a remote control physical/virtual keypad. The first time of day may be before sunrise, followed by a second time that triggers a sunrise event. Each of the sunrise, morning and noon hours of the day addresses a different data set or content stored within the corresponding group or groups of lighting devices. For example, the time-before-day output from the timer triggers the first content or data set to be automatically displayed and an appropriate ratio of current is sent to the LED chain to produce a relatively low color temperature. Thus, the timer triggers a first content comprising a relatively low lumen output and color temperature. Manual adjustment of an actuator, such as a dimmer or physical keypad, will reduce the brightness 120 by an amount that will occur before an automatic change to a higher color temperature in the display occurs, such as during the morning hours when 3200Kelvin is typically produced, and importantly, for a brightness reduction 120, the color temperature, which typically reaches 3200Kelvin, will be reduced to well below 3200Kelvin. The brightness reduction 120 and significant reduction in color temperature may remain for the timeout period until the next time-of-day signal is sent, or a time signal after the next time-of-day signal, or when the trigger is actuated again to release the manual override mode.
A significant decrease in color temperature during manual override dimming (or an increase in color temperature during reverse dimming) when the trigger is actuated may occur without any fade-ins. However, it is desirable to have a fade-in occur in the color temperature automatic change during display and prior to manual override. Also, it is desirable to send less time of day signals from the timer to minimize the amount of auto-fade-in of color temperature change. As shown in fig. 13b, for example, one hour after sunrise, a first time of day signal is sent to increase the color temperature in a plurality of steps 121, linearly 123 or exponentially 125 over a fixed time preferably less than two hours and more preferably less than one hour. In order to minimize the number of time-of-day signals, there may also be a time-of-day signal that decreases the color temperature in a plurality of steps, linearly or exponentially, within one or two hours before sunset. There may be only two time of day signals and sending those signals twice a day will significantly reduce the amount of traffic required to perform the display and will reduce the amount of content that needs to be stored in one or more groups of luminaires.
Fig. 13b also illustrates the same brightness reduction 120 as shown in fig. 13a, for example, if the user actuates the slider on the dimmer or physical keypad the same amount as he or she was adjusted one hour after sunrise (i.e., morning) in fig. 13 a. However, in FIG. 13b, if the slider is actuated at noon in the day, the same brightness reduction 120 produces a significantly smaller color temperature reduction than at sunrise as shown in FIG. 13 a. At noon, the color temperature, which is automatically and dynamically set at noon hours of the day, e.g. 6500Kelvin, drops slightly below 6500Kelvin (< 6.5K Kelvin), and this drop is much smaller than the color temperature drop that would occur in the morning or at sunrise (< 3.2K Kelvin). Thus, the influence of the brightness change on the color temperature depends on the time of day, since, as indicated above, the spectral sensitivity of a LED chain producing a lower color temperature is far more meaningful than the spectral sensitivity of a LED chain producing a higher color temperature (robust). Even if the power or current supplied to all LED chains changes by the same amount based on the change in intensity values, the color temperature of cold white, for example, having a blue spectral output dominance during noon hours, will change less than the red spectral output that is predominantly produced during sunrise or pre-sunrise hours.
The circadian rhythm display may be used to simulate daylight at different times of the day and may continue in different groups of lighting devices within the structure. However, if a certain set of lighting devices requires a defined task, or requires changing the simulation to be closer to outdoor-like daylight conditions, the user may manually modify the circadian display to have a more profound effect on color temperature at certain times of the day than at other times of the day. A significant benefit of the present invention is that, for example, changes in brightness one hour after sunrise and one hour before sunset have a greater effect on the color temperature than any time in between.
Even if dimming occurs manually, it is desirable that the effect on color simulation be reduced at higher color temperature times than at lower color temperature times so that the circadian rhythm is not significantly interrupted even if the user manually changes the circadian display that occurs automatically throughout the day. In other words, it is more advantageous to change the circadian display during warm white lighting output times to a warmer color temperature than during cold white lighting output times that typically occur during peak daylight hours. In this way, the manual adjustments needed to perform a task or more closely resemble actual outdoor daylight conditions are still more consistent with actual outdoor daylight conditions. Warm white remains warmer white, while cool white remains cool white, and so on.
Reverse dimming may also be performed manually. At night, the user may actuate a trigger to manually override the night time automatically changing color temperature display, which may be programmed to have no illumination output regardless of the time of day signal sent (or, in this case, the time of night signal sent). For example, a user may wish to actuate a toggle button or up/down button on a physical keypad of a bedroom to override the non-illuminated output display to increase the brightness and color temperature within the group of luminaires within the bedroom. The reverse dimming advantageously results in a lower color temperature output to mimic the incandescent lamp lighting output that typically occurs when a user wakes up from bed and turns on the incandescent lamp during nighttime hours. Manual override of reverse dimming, which occurs at night, is similar to daytime because the change in brightness has a greater effect at lower color temperatures than at higher color temperatures. Thus, the present invention is applicable to circadian displays that extend beyond daylight, and manual overrides are equally applicable to any change in brightness and have a greater effect on lower color temperatures than on higher color temperatures.
Turning now to fig. 14, the storage medium 56 may contain content or data sets associated with the lighting device containing the storage medium 56. Each of the groups of lighting devices, possibly grouped according to the description shown in fig. 9 and 10, may contain the same content for the respective group of lighting devices. For example, content in the color temperature setting for various times of day 124 or various conditions 126 that the sensor may perceive. The various times of day 124 or daylight conditions 126 stored in each of the groups of lighting devices with storage medium 56 are triggered by time messages in the case of time of day 124 or sensor readings in the case of daylight conditions 126.
As shown in fig. 14, the time message may activate or execute on the content stored in the storage medium 56 depending on the value of the time message, e.g. will execute on a noon time of day data set 124, then the time message will most likely be at or near the local noon time of the timer within the remote control. A timer or real time clock with remote control 64 may send an appropriate time message to address the appropriate content of the current time of day 124. The time message will change the color output of the corresponding group of lighting devices with a similar stored time content or data set. Alternatively, a button of a particular display, such as button 1 of display a, will be invoked, which when button 1 is pressed will cause the initiation of display a. This will result in sending an appropriate time message or, alternatively, a timer may be found in each luminaire that automatically changes the fetched content at regular periodic intervals, e.g. by simply initiating display a. Whether the time message is sent from a remote controller timer or the timer is present in the group of lighting devices based on the programmed display, the control circuit controller 54 executes a periodically changing, automatically changing sequence of content or data sets to simulate daylight changes along the day trajectory from as little as 2000Kelvin at early sunrise to a maximum of more than 6000Kelvin at midday time, and then falls back to less than 2000Kelvin at sunset. According to an alternative embodiment, a sensor similar to the temperature sensor 58 may be employed to measure sunlight inside or outside the structure, and then automatically and dynamically change the content or data set extracted and executed based on the sensor readings, so that the sensed sunlight can be simulated not only along the trajectory of the day but also at any chromaticity point or spectrum.
Fig. 15 is a graph of color, specifically color temperature or CCT, which changes as a function of both time of day and brightness. For the above reasons, the color temperature changes automatically and dynamically during the day. As shown, the color temperature output from the plurality of LED chains is automatically changed to replicate the actual daylight conditions outside the structure, and to simulate, for example, the natural daylight required to treat circadian rhythm disorders. At off-peak daylight hours, such as pre-sunrise, morning sunrise, and evening and sunset times, the color temperature may simulate sunrise and sunset times along the day's track. Preferably, the target color temperature is less than, for example, 3200 or 3000Kelvin during the morning and evening hours, and may be as high as 6000 or 6500Kelvin around midday hours. 6000-6500Kelvin may simulate the midday time of a blue day, while 3500 or less than 3000Kelvin may simulate a mixture of mostly yellow with some red morning or evening sky. Fig. 15 illustrates different times of day (TOD), starting with TOD1 to TOD6, and possibly more.
Fig. 15 also shows a change in luminance from, for example, full luminance BR1 to a luminance (or BR 2) less than full luminance. According to one embodiment, the brightness is changed from one level BR1, which is constant during the day, to another level BR2, which is also constant during the day. According to another embodiment, the brightness is changed from one level BR1, which changes during the day, to another level BR2, which also changes during the day. In either embodiment, the luminance is changed from BR1 to BR2, resulting in the effect on the color temperature being shown depending on the time of day, the effect at TOD4 being relatively small, but the effect at TOD1-3 and TOD5 and TOD6 being larger. The difference in color temperature for the same luminance change is shown by different arrows 130 and 132. Arrow 130 indicates a change in color temperature greater than arrow 132, but the change in brightness from BR1 to BR2 is the same. The change in brightness is achieved by a change in intensity of the remote control or dimmer. When the trigger on the remote control or dimmer is reduced to, for example, half of its adjustment amount, the intensity may be reduced by half, and according to the first mapping of brightness to intensity shown in fig. 12, the brightness may be non-linearly reduced by an amount close to half of the previous brightness. If BR2 represents half luminance relative to BR1, the color temperature changes not only with luminance, but also with time of day. For example, at noon, the color temperature is relatively unaffected even if the slider has moved to indicate, for example, half brightness. This effect is valuable because at noon when the user wishes to perform a task and reduce the brightness by manually adjusting the slider, it is desirable to place the simulated daylight in natural daylight conditions of 6000Kelvin or higher even if the slider is moved. This ensures that the simulated daylight conditions after the manual override still appear normal to the external ongoing situation. In other words, even if the user adjusts the dimming of the brightness along the dimming curve, the daytime natural daylight conditions simulated by the plurality of LEDs remain near peak daylight hours. Conversely, if the user dims along the dimming curve at sunrise or morning hours, the color temperature will drop more than at noon, which is advantageous because the actual daylight conditions are more so at warm white temperatures during those hours, and any changes to the dimming will remain more than the warm white conditions that occur outside.
Fig. 15 also shows, in dashed lines, that according to the second embodiment the brightness changes from one level BR1, which changes over the course of a day, to another level BR2', which also changes over the course of a day. In this embodiment, any actuation of the trigger slider to invoke a manual override will have the same effect in the color temperature change throughout the day, as shown by arrows 130 and 132' indicating equal amounts of change at different times of the day.
A major advantage of preferred embodiments of the present invention is that simulated natural daylight conditions remain when a task is to be performed, for example, when a brightness reduction occurs through a dimming curve that is manually adjusted by a user. Continuing to simulate daylight conditions throughout the awake time and beyond, may be beneficial for psychological and aesthetic reasons even when manual dimming or reverse dimming occurs, e.g., the lighting may be more suitable for simulating incandescent lighting that produces more warm white color temperatures, such as halogen, etc., shortly after sunrise and before sunset. Thus, the color simulation is most suitably implemented as an astronomical display, since the natural lighting varies to the greatest extent depending on whether the sun is up or down (in particular the path length of the sun). However, when performing certain tasks, it is not necessary to couple brightness to a time-based display, so the preferred embodiment allows the user to adjust the brightness as desired. For example, changing the brightness at noon hours changes the brightness of the simulated sun in its peak daylight condition while maintaining the peak daylight or high color temperature condition. Conversely, changing the brightness in the morning or evening of a day changes the brightness of a simulated incandescent lamp, where it is more desirable to produce a lower color temperature than at midday. Thus, the preferred embodiments of the present invention are not necessarily drawn for automatic and dynamic changes in color temperature throughout the day, but rather are drawn to task lighting conditions that are periodically required by the user throughout the day, where brightness may change but the effect on color temperature depends on the time of day that the user actuates the dimmer.
Fig. 16 illustrates the effect on color temperature or CCT when brightness is manually adjusted at different times in the morning and midday (TOD 3 and TOD 4). Specifically, fig. 16 indicates a larger change in color temperature when the luminance is manually changed from BR1 (shown in solid lines) to BR2 (shown in dotted lines) in the morning time of TOD3 and the midday time of TOD 4. At TOD3, the color temperature substantially decreases as the brightness changes from BR1 to BR2 as indicated by arrow 134. However, as indicated by arrow 136, when the luminance is changed from BR1 to BR2, the color temperature hardly drops as much as TOD3 in the morning at noon time TOD 4. Of course, fig. 16 is an example of various TODs, and does not represent that only two TODs may be used: one hour after sunrise and one hour before sunset, and possibly sunset or night. Also, fig. 16 does not illustrate TOD after sunset, nor does it illustrate reverse dimming that may occur after day or night. Still further, fig. 16 does not illustrate the fade-in of the automatic change in color temperature that will occur at each TOD.
Fig. 17 illustrates how user input from a manually activated trigger (such as a slider) on a triac dimmer or associated with a physical or virtual keypad produces intensity values that are fed into the dimming curve module 140, which contains a non-linear first mapping of intensity values to luminance values within the storage medium, and maps luminance values corresponding to the intensity values input to the dimming curve module 140. The color simulation module 142 receives the brightness value and a time of day message or TOD value from, for example, a timer 144. A combination of TOD and luminance (BR) values is received through a second mapping of color temperature as a function of time of day and a luminance input. Thus, the color simulation module 142 performs a second mapping of the color temperature according to the time of day and the luminance level input thereto. The color simulation module 142 generates a corresponding color temperature along an X/Y chromaticity diagram, specifically along a black body curve of the color temperature. Knowing the appropriate chromaticity, the chromaticity module 146 may include control circuitry and LED drive circuitry for controlling each LED chain by sending an appropriate drive current to each of the plurality of LED chains. Accordingly, the chromaticity module 146 includes controlling and driving the plurality of LED chains to produce appropriate illumination from each of the plurality of LED chains. The combination of the first and second mappings produces, via the luminance dimming curve module 140 and the color simulation module 142, the appropriate drive currents within the chromaticity module for maintaining daylight simulation dependent on time of day and luminance changes.
It will be appreciated by those skilled in the art having the benefit of this disclosure that the present invention is believed to provide an improved lighting device, system and method which not only simulates daylight throughout the day, but can also maintain the simulation when a lighting task is required, for example by advantageously lowering the color temperature more during the morning and evening hours than during midday hours. Further modifications to alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. It is therefore intended that the following claims be interpreted to embrace all such modifications and changes and, accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.