BACKGROUNDThe present invention relates generally to in-flight aircraft entertainment systems, and more particularly, to a low cost, hybrid video distribution system for use with in-flight aircraft entertainment systems.
The assignee of the present invention designs and manufactures in-flight entertainment systems for aircraft, and the like. Heretofore, full cable television (CATV) type radio frequency (RF) distribution systems have been used in most aircraft in-flight aircraft entertainment systems. These cable television type RAF distribution systems require a tuner at every seat. The cost of tuners is relatively high, and because of the large number of seats and associated tuners, the overall cost of prior distribution systems has been high.
It would therefore be desirable to have an alternative in-flight entertainment system that does not replace the full RF system, but provides a low cost system for use in commercial aircraft, and particularly in narrow body commercial aircraft. Such a low cost -flight entertainment system would make video sources such as DIRECTTV satellite broadcasts, for example, a viable option on short haul aircraft flying routes within the continental United States.
Accordingly, it is an objective of the present invention to provide for a video distribution system for use with in-flight aircraft entertainment systems. It is a further objective of the present invention to provide for a hybrid video distribution system that permits distribution of direct broadcast satellite programming to passengers on short haul aircraft flying routes within the continental United States.
SUMMARY OF THE INVENTIONTo meet the above and other objectives, the present invention provides for an architecture for a low cost in-flight aircraft entertainment (video and audio) distribution system that supports reception of satellite broadcasts from a direct broadcast satellite source, such as from DIRECTTV satellites, for example, along with other video programming, such as video tapes, and laser disks, and the like. The present video distribution system thus distributes video derived from a wide variety of video sources to passengers of an aircraft.
The in-flight aircraft entertainment system comprises a video control center, a plurality of groups of seat display units, and a plurality of audio and video processors that control routing of video channels to each respective seat display unit. A plurality of seat junction boxes may be interposed between the plurality of audio and video processors and the plurality of groups of seat display units to simplify interconnection of these components.
The video control center includes an antenna for receiving programming broadcast from a direct broadcast satellite, and a splitter for generatING a plurality of channels of programming received by the antenna. A decoder decodes the channels to provide video and audio signals for distribution. An RF modulator modulates the decoded audio and video signals.
Each seat display unit comprises a keypad for selecting channels and controlling the volume of the audio signals for the selected channels, a logic circuit for outputting channel addresses corresponding to the selected channels, an address decoder for decoding the channel addresses, and a channel display for displaying the number of the selected channel. A video display is provided for processing the video signals to display the selected channel, and an audio output device is provided for reproducing the audio signals for each of the channels.
The plurality of audio and video processors convert the modulated RF video signals to baseband video for distribution to each of the seat display units. Each of the processors comprise a plurality of tuners, and non-blocking audio crosspoint switches having a predetermined number of audio and video outputs that are a selected multiple of the number of inputs. A processor is coupled to the audio and video crosspoint switches and coupled to the address decoder of each of the seat display units for receiving the decoded channel addresses and for selecting which channels are output to eachseat display unit40 in response thereto.
The in-flight aircraft entertainment distribution system distributes audio and video without requiring a tuner at every seat. In the in-flight aircraft entertainment distribution system, one tuner is provided for each video program that is used to service a predetermined large number of seats. In a reduced-to-practice embodiment of the resent invention, one tuner is provided for a group of 48 seats. Distribution of video programs is handled in an area video processor as requested on a serial communications link from a seat display unit serving each seat.
In the case of an eight video program (eight tuners) system, for example, the quantity of tuners required for the system is reduced from 48 to 8. At approximately $150 per tuner, $6600 per group of 48 seats is saved using the present invention. On a 747-400 aircraft having 400 seats, for example, this represents a savings of $55,000 in the cost of the system. The present invention removes the tuner from the seatback, allowing larger displays to be installed, while reducing the power requirements of the system. Due to the reduction in the number of components, the mean time between failure (MTBF) of the system increases, thus reducing service costs.
The present system was originally developed to permit the display of direct satellite broadcasts on narrow body aircraft. However, the present video and audio distribution system provides a low cost distribution solution with or without the ability to distribute direct broadcast satellite programming. Signals from any video or audio source may be inexpensively distributed throughout the cabin of an aircraft using the present system.
BRIEF DESCRIPTION OF THE DRAWINGSThe various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
FIG. 1 is a system block diagram illustrating an embodiment of a hybrid in-flight audio and video distribution system in accordance with the principles of the present invention;
FIG. 2 illustrates details of a seat junction box used in the system of FIG. 1; and
FIG. 3 illustrates details of a seat display unit used in the system of FIG.1.
DETAILED DESCRIPTIONReferring to the drawing figures, FIG. 1 illustrates one embodiment of a hybrid in-flight audio andvideo distribution system10 in accordance with the principles of the present invention. The in-flight audio andvideo distribution system10 comprises avideo control center11 that is designed to output a variety of video and audio signals for distribution to passengers of an aircraft. For example, a video tape recorder (VTR)15 can be used to provide prerecorded programming on video tapes. Thevideo control center11 has asplitter13 that is coupled to an antenna12 that receives programming broadcast from a direct broadcast satellite such as from satellites of the DIRECTTV satellite system, for example. The antenna12 is coupled by way of thesplitter13 to aDirectTV decoder14. Thesplitter13 that splits off a plurality of channels of programming which are each decoded by thedecoder14. Outputs of thedecoder14 include video and audio signals for each of the channels. The video signals are coupled to a system control unit (SCU)16 which provides an operator and airframe interface to thevideo distribution system10. The output signals from theSCU16 are coupled to anRF modulator17. TheRF modulator17 modulates the audio and video signals contained in the decoded video channels. The modulated audio and video signals are coupled to an audio andvideo processor20 in accordance with the principles of the present invention which processes the signals and routes them by way of a plurality ofseat junction boxes30 to a plurality ofseat display units40.
Video sources in thevideo control center11, also known ashead end equipment11, are modulated onto asingle coax cable18 by theRF modulator17. This CATV-type video signal is routed to the audio andvideo processor20, where it is converted to baseband video for distribution to the seat displays. The audio andvideo processor20 comprises a plurality ofinput connectors21a,21b, wherein thefirst connector21a is coupled to receive 115 VAC, 400 Hz power for thepower supply22 and wherein thesecond connector21b is coupled to the next audio andvideo processor20 of thesystem10.
The audio andvideo processor20 comprises a plurality oftuners25, onetuner25 for each video program decoded by thedecoder14. In the embodiment of thesystem10 shown in FIG. 1, sixtuners25 are employed in the audio andvideo processor20 to route programming to forty-eight seat display units. The modulated RF video signal is coupled by way of atap23 and avideo amplifier24 to each of thetuners25. The modulated RF video signal is also coupled by way of thetap23 to the next audio andvideo processor20 in the chain via thesecond connector21b.
Each of therespective tuners25 have a pair of audio outputs and a video output respectively coupled to inputs of non-blocking audio andvideo crosspoint switches26,27. The non-blocking audio andvideo crosspoint switches26,27 select which program is sent to a particularseat display unit40. This is controlled by RS-485 data originating at the seat display unit, which will be discussed with reference to FIG.3. The RS-485 data is input to aprocessor28 that outputs control signals to the non-blocking audio andvideo crosspoint switches26,27 to select which program is sent to eachseat display unit40.
Theaudio crosspoint switch26 has six sets of audio inputs and forty-eight pairs of audio outputs. Thevideo crosspoint switch27 has six sets of video inputs and forty-eight video outputs. Audio and video output signals from the audio and video crosspoint switches26,27 are routed by way ofoutput connectors29 on the audio andvideo processor20 to a plurality ofseat junction boxes30.
FIG. 2 illustrates details of theseat junction box30 used in the system of FIG.1. Each of theseat junction boxes30 processes six sets of audio and video input signals received by way of aninput connector31 and outputs the first three sets of audio and video output signals by way of afirst output connector32a, and outputs the second three sets of audio and video output signals by way of asecond output connector32b. Each of theseat junction boxes30 contains apower supply33 that converts 115 VAC, 400 Hz power into ±28 volt DC power to drive theseat display units40.
FIG. 3 illustrates details of theseat display unit40 used in the system of FIG.1. Theseat display unit40 has aninput connector41 that is coupled to theoutput connector32a, for example, of theseat junction box30. Theinput connector41 receives the three sets of audio and video output signals and ±28 volt DC power from theseat junction box30. The RS-485 data is routed by way of theinput connector41 to theprocessor28 of the audio andvideo processor20. Anoutput connector42 is used to pass through the three sets of audio and video output signals and the ±28 volt DC power to an adjacentseat display unit40. Anaudio jack43 is provided for connection to passenger headphones.
Theseat display unit40 comprises akeypad44 comprising a plurality of switches that include a channel upswitch44a, a channel downswitch44b, an on/offswitch44c, a volume upswitch44d, and a volume downswitch44e. The channel up and channel downswitches44a,44b are coupled to data receive and transmitlogic45. The data receive and transmitlogic45 outputs channel addresses (ADDR) for the appropriate programming channel selected by the passenger. The data receive and transmitlogic45 is coupled to achannel display46 which displays the selected channel to the passenger, and to anaddress decoder47 whose output lines are coupled to a +5 volt DC source by way of a plurality ofresistors48 to properly set the voltage level of the decoded address transmitted to theprocessor28 in the audio andvideo processor20.
A video enablekey51 is provided that is coupled to avolume control circuit52 and avideo display53 which is used to activate them. A 5 inchLCD seat display53 is used in the reduced to practice embodiment of thesystem10. The volume up and volume downswitches44d,44e are coupled to thevolume control circuit52. The on/offswitch44c and is coupled to thevolume control circuit52 and to thevideo display53 to turn them on and off. Thevolume control circuit52 is coupled to theaudio jack43 and couples audio signals thereto that may be used to drive a set of headphones.
Apower regulator54 is coupled to the ±28 volt DC lines and provides regulated power to components of theseat display unit40 that require regulated power. These components include the data receive and transmitlogic45, thechannel display46, theaddress decoder47, thevolume control circuit52 and thedisplay53.
In operation, channels are selected by a passenger using thekeypad44. Seat identification is accomplished by wiring in the cable coupled to theseat display unit40 identified by addressed ADDR1-ADDR3.Seat display units40 are grouped in sets of three. By routing the audio and video signals from two to one and three to two in everyseat display unit40, the proper signals do not need to be switched in theseat display unit40. This enables theseat display units40 to occupy any of three relative positions in a seat group without requiring special configuration. DC power is provided to theseat display unit40 via thepower supply33 in theseat junction box30. Theseat junction box30 also serves as a cable junction and disconnect box.
In the reduced to practice embodiment of thepresent system10, there is no interface to other aircraft systems, such as passenger service systems or existing audio entertainment systems. Thepresent system10 provides for ahybrid system10 containing both RF and baseband processing that takes advantage of RF distribution throughout the aircraft and baseband distribution within an area provided by respective audio andvideo processor20 to a predetermined number ofseat display units40. In the reduced to practice embodiment of thesystem10, the number of video channels can range from 2 to 6, with each channel providing one stereo pair or two monoaural languages.
The reduced to practice embodiment of the in-flight audio andvideo distribution system10, each audio andvideo processor20 receives a composite analog video signal that has been modulated using a single RF carrier. Thesystem10 provides control for up to eight channels of video programming each with an associated stereo audio pair (or two monoaural languages). The RF signal is routed to the audio andvideo processor20 for distribution to up to 48 seats. The audio andvideo processor20 contains up to eighttuners25, one for each channel. Thetuner25 output is routed through the non-blocking audio and video crosspoint switches26,27 that have the capability to switch any one of the weight tuner outputs to any one of the 48 seat outputs. In addition to thetuner25 and the audio and video crosspoint switches26,27 in the audio andvideo processor20 provide a serial control interface to theseat display units40 along with appropriate video and audio amplifiers.
The video, audio and data signals are routed through theseat junction box30 that provides power to up to sixseat display units40. Theseat junction box30 communicates with the audio andvideo processor20 through the RS-485 serial interface and polls theseat display units40 for video control switch processing. Thejunction box30 provided power to theseat display units40 and a also provides a means to interconnect the audio andvideo processor20 to theseat display units40.
Thus, a hybrid video distribution system for use with in-flight aircraft entertainment systems has been disclosed. It is to be understood that the described embodiment is merely illustrative of some of the many specific embodiments which represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.