JP2508437B2 - Information transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A Industrial Field B Outline of Invention C Conventional Technology D Problems to be Solved by the Invention E Means for Solving Problems (Fig. 1) F Action G Example G ₁ Explanation of sender G ₂ Description of the transmitting side H Effect of the invention A Industrial field of application The present invention relates to a plurality of video signals in a video display section and a sound generating section which are individually provided in a passenger seat of an aircraft, a train, a bus, or in the vicinity thereof. , An information transmission device suitable for use in transmitting voice signals in parallel.

B. Summary of the Invention The present invention is an information traditional apparatus that transmits a plurality of video signals and audio signals in parallel from a transmission side to a reception side, and multiple video signals and audio signals are multiplexed into a single signal transmission means. In addition to automatically exchanging video signals or audio signals from video signal sources or audio signal sources corresponding to channels that have been transmitted and have not been selected for a certain period of time in all terminal devices, the channel and new video signals or By displaying the contents of the audio signal on each terminal device, the device is simplified and the service to the user of the terminal device is improved.

C PRIOR ART For example, U.S. Pat. No. 4,584,603 shows that a video display is individually provided in a passenger seat of a vehicle such as an aircraft. That is, a video display is individually provided in the passenger seat, and a plurality of video signals are transmitted to these video displays in parallel, and each video display selects and displays one of the signals.

D. Problems to be Solved by the Invention In this conventional apparatus, a plurality of video signals are transmitted to each video display by using independent transmission lines, which requires many transmission lines. Is. Therefore, there is a problem that the wiring is complicated and the device is complicated.

The present invention has been made in view of such a point, while simplifying the device,
It is intended to improve the service to the terminal device user.

E Means for Solving Problems (FIG. 1) In the present invention, a plurality of video signal sources (1a) to (1
c), a plurality of audio signal sources (2a) to (2d), a computer (4), video signals from a plurality of video signal sources (1a) to (1c), a plurality of audio signal sources (2a) to multiplexes control data DC ₁ 'from the audio signal and computer (4) from (2d), the bidirectional signal transmission device the multiplexed signal (11)
To the transmitters (3), (5a) to (5d), (6),
It has a central control unit including a receiving section (8) for receiving control data DC ₂ from the receiving side supplied from the bidirectional signal transmitting means (11) and supplying the control data DC ₂ to the computer (4). Selection units (23), (24) and (26) for selecting a predetermined video signal and audio signal from the multiplexed signal supplied from the bidirectional signal transmission means (11), and the selection units (23) and (2
4), the video display section (28) and the audio generation section (30) to which the video signal and the audio signal selected in (26) are supplied, and the multiplexed signal supplied from the bidirectional signal transmission means (11). Separation unit (26) for separating control data DC ₁ ′ from the transmission side
And a unique address generator (31) and a selection operation unit (25)
And the control data DC ₁ separated by the separation unit (26), the signal from the selection operation unit (25) and the address data from the unique address generation unit (31) are supplied to the selection units (23), (2
Control data 4) and (26) and control data D to the sending side
A plurality of terminal devices (20F) provided with a microcomputer (260) for generating C ₂ and a transmission section (32) for supplying control data DC ₂ from the microcomputer (260) to the bidirectional signal transmission means (11). ), (20B). The present invention is configured such that the video signal sources (1a) to (1c) and the audio signal sources (2a) to (2d) reproduce the video signal and the audio signal from the recording medium, and the recording medium can be replaced. Enabled and central control unit computers (4)
Then, the channel selection states of the terminal devices (20f) and (20B) are aggregated based on the control data DC ₂ from the receiving side, and the video signal sources (1a) to ((a) to (1a) to (( 1c) or audio signal sources (2a) to (2
The recording medium of d) is exchanged under the control of the computer (4), and the control data DC from the computer (4) is exchanged.
_{As 1} ', control data including data indicating a channel that has not been selected for a certain period of time and data indicating the content of the video signal or audio signal recorded on the exchanged recording medium is generated, and the video display of each terminal device is generated. The content of the video signal or the audio signal recorded in the channel which has not been selected for a certain period of time and the exchanged recording medium is displayed in the section (28).

F action In the above configuration, a plurality of video signals, audio signals, etc. are multiplexed by the transmitters (3), (5a) to (5d), (6),
Since it is supplied to the receiving side terminal devices (20F) and (20B) through the bidirectional signal transmission means (11), the selection operation section (25).
The predetermined video signal and audio signal can be selected by the operation of.

In addition, in the above configuration, a plurality of terminal devices (20
When there is a channel that has not been selected for a certain period of time in all of F) and (20B), the transmitting computer (4)
Video signal source (1a) corresponding to that channel
~ (1c) or audio signal sources (2a) to (2d) are controlled,
The recording medium is exchanged for another one. At this time,
Including data TI indicating the contents of the sending computer (4) from the control data DC ₁ video signal or audio signal is recorded in and exchanged recording medium '(data CH indicating the channel that is not selected fixed time' ) Is generated, and this is multiplexed with the video signal and the audio signal and supplied to the bidirectional signal transmission means (11). Then, each terminal device (20
F), ( 'the separated, this control data DC _1' control data DC ₁ by the demultiplexer (26) of 20B) on the basis of each terminal device (20
The display units (28) of F) and (20B) display the contents of the video signal or the audio signal recorded in the channel which has not been selected for a certain period of time and the exchanged recording medium.

G Example One example of the present invention will be described below with reference to FIG. This example is applied to transmission of video signals, audio signals, and the like in an aircraft.

G ₁ Explanation of transmitting side In FIG. 1, (1a) to (1c) are video tape recorders provided on the transmitting side such as in the cabin of an aircraft,
It is equipped with an auto change mechanism for video cassettes, and is exchanged under the control of a master controller described later. Video tape recorder (1a)
And (1b), a terminal V for outputting a video signal and a first
Terminals L and R for outputting a left audio signal and a right audio signal in a national language and a terminal A for outputting a monaural audio signal in a second language are provided. Further, the video tape recorder (1c) has a terminal V for outputting a video signal.
And terminals L and R for outputting the left audio signal and the right audio signal are provided.

Further, (2a) to (2d) are compact disc players (CD players), which are provided with a disc automatic change mechanism, and are exchanged under the control of a master controller described later. The compact disc players (2a) to (2d) are provided with terminals L and R for outputting a left audio signal and a right audio signal.

Further, (3) is a CADA encoder used in a conventionally known cable digital audio / data transmission system (CADA system). The CADA system is, for example, a system in which multiple digital audios are time-division-multiplexed and transmitted using the band (6MHz) of a vacant TV channel of CATV. Music and the like are extremely efficient without impairing the sound quality. It is a system that can transmit. The CADA encoder (3) comprises an A / D converter and a shift register, converts a plurality of audio signals into digital signals by the A / D converter, and inputs the digital signals in parallel to predetermined positions of the shift register. At the same time, the shift register outputs the signals serially at a high speed to perform time division multiplexing. Note that not only digital audio but also control data can be multiplexed together.

The audio signals obtained at the terminals L, R, A of the video tape recorder (1a) and (1b), the audio signals obtained at the terminals L, R of the video tape recorder (1c), and the compact disc player (2a) to The audio signals obtained at the terminals L and R of (2d) are supplied to the encoder (3), respectively.

Further, (4) is a master controller composed of a computer for in-flight management. As will be described later, when control data DC ₂ (including address data AD indicating a seat, channel selection data CH and volume data VR) is supplied from the receiving side, the address indicating the seat after the seat indicated by the address data AD Data AD is calculated, and control data CD ₁ including address data AD ′, channel selection data CH and volume data VR is generated from this master controller (4). This control data DC ₁ is supplied to the encoder (3).

In addition, the master controller (4) uses control data DC
Based on ₂ , the channel selection status of each terminal device is aggregated. Then, when there is a channel that has not been selected for a certain period of time, for example, about 5 minutes in all the terminal devices, the video tape recorders (1a) to (1c) or the compact disc player (2) corresponding to the channel.
a) to (2d) are controlled and the video cassette or disc is replaced. At this time, the master controller (4) indicates the data CH'indicating a channel that has not been selected for a certain period of time and the contents (title, etc.) of the video signal or audio signal recorded in the exchanged video cassette or disc. Control data DC ₁ ′ containing data TI is generated. This control data DC ₁ ′ is supplied to the encoder (3). The data TI is previously stored in the memory in the master controller (4).

Eventually, at the output terminal O of the encoder (3), the digitally exchanged plurality of supplied audio signals and the time-division multiplexed signal S _{CA of the} control data DC ₁ or DC ₁ ′ are obtained. The S _CA is supplied to the modulator (5d) and is AM-modulated by the VSB (Vestigial Sideband) method.

The terminal V of the video tape recorder (1a) to (1c)
The video signals obtained in the above are respectively supplied to modulators (5a) to (5c), and are respectively AM-modulated by the VSB system. Here, the modulators (5a) to (5d) are, for example, 60 or more television broadcasting channels, and sequentially perform modulation in frequency bands of every two channels to prevent intermodulation.

The output signals of the modulators (5a) to (5d) are supplied to the adder (6) and frequency-multiplexed. The frequency-multiplexed signal S _MF from the adder (6) is sent to the demultiplexer (7).
Is supplied to one end of a leaky cable (leakage cable) (11) constituting the bidirectional signal transmission means. A terminating resistor (12) is connected to the other end of the leaky cable (11) for termination. This leaky cable (11)
For example, the circumference of the coaxial cable is cut out in a spiral shape to increase the amount of signal leakage.

G ₂ Receiving side description In addition, each passenger seat of the aircraft is individually provided with a terminal device. In the figure, as shown in FIG.
Terminal devices (20F), (2
0B) is shown.

In the terminal device (20F), (21) is an antenna for capturing the frequency multiplexed signal S _MF leaking from the leaky cable (11). The frequency-multiplexed signal S _MF captured by the antenna (21) is supplied to the television tuner (23) and the CADA tuner (24) via the demultiplexer (22). The tuner (23) is selected so that it can select a channel in the output frequency band of the modulators (5a) to (5c), and the channel selection is made in the CADA decoder (26) according to the key operation on the control panel (25). It is controlled by a microcomputer (hereinafter referred to as "microcomputer"). The video signal output from this tuner (23) is processed by the signal processing circuit (2
It is supplied to a display device (28) including a flat cathode ray tube, a liquid crystal display device, etc. via 7).

In addition, the tuner (24) is configured to selectively receive a channel in the output frequency band of the modulator (5d). The time division multiplexed signal S _CA output from this tuner (24) is CAD
It is supplied to the A decoder (26). The decoder (26) is configured to operate in a manner almost opposite to that of the CADA encoder (3) described above, and is controlled by the microcomputer in the decoder (26) to extract a desired audio signal from the time division multiplex signal S _CA. , Control data DC ₁ or DC ₁ ′ is taken out from the time division multiplexed signal S _CA.

The audio signal taken out by the decoder (26) is supplied to the headphones (30) via the audio output terminal (29).

(31) is an address ROM, and this address ROM
(31), the Yes and unique address data AD _F indicating the distribution has been that the seat of the terminal unit (20F) is written,
Address data AD _F from the address ROM (31) is supplied to the microcomputer decoder (26).

Time division in the microcomputer if the multiplexed signal S _CA from control data DC ₁ is taken out, and control the address data AD _F data DC ₁
Is compared with the address data AD ′ contained in, the decoder (26) extracts the audio signal based on the channel selection data CH contained in the control data DC ₁ and outputs the volume based on the volume data VR. Controlled.

When the control data DC ₁ ′ is extracted from the time division multiplexed signal S _CA , the signal processing circuit (27) is controlled by the microcomputer and the channel and video signal based on the data CH ′ and TI included in the control data DC ₁ ′. The video signal from the tuner (23) is superimposed on the video signal from the tuner (23) for a predetermined time, or the video signal showing the content of the channel and the video signal based on the data CH ′ and TI included in the control data DC ₁ ′ is displayed. The video signal from the tuner (23) is replaced for a predetermined time. In this case, the character signal generator or the video signal generator is provided in the microcomputer or the signal processing circuit (27).

Further, when the reception channel is selected by the key operation of the control panel (25) is a microcomputer decoder (26), the control data DC ₂ including the address data AD _F and channel selection data CH and volume data VR is generated , This control data DC ₂ is supplied to the transmitter (32) and is modulated to a frequency other than the output frequency band of the modulators (5a) to (5d), and then passed through the duplexer (22) and the antenna (21). Supplied to the leaky cable (11).

Although not mentioned above, this data is supplied from the leaky cable (11) to the receiver (8) via the demultiplexer (7) on the transmission side, demodulated, and then mastered via the encoder (3). It is supplied to the controller (4).

Further, FIG. 3 shows the decoder (26) and the control panel (25) in more detail. This third
In the figure, the parts corresponding to those in FIG. 1 are designated by the same reference numerals.

In the figure, the television tuner (23) is controlled by the microcomputer (260) of the decoder (26) according to the key operation of the control panel (25).

Also, the time division multiplexed signal S _CA from the CADA tuner (24)
Is supplied to the carrier regenerator (261) of the decoder (26) and also to the command decoder (262), shift registers (263) and (264). Carrier regenerator (26
A clock signal synchronized with the time division multiplexed signal S _CA is obtained from 1), and this clock signal is supplied to the microcomputer (260) and also to the command decoder (262), shift registers (263) and (264). To be done. The command decoder (262) outputs control data from the time division multiplexed signal S _CA.
DC ₁ or DC ₁ ′ is taken out, and this control data DC ₁ or DC ₁ ′ is supplied to the microcomputer (260).

A latch signal is supplied from the microcomputer (260) to the shift registers (263) and (264) at a predetermined timing, and a predetermined audio signal is extracted from the shift registers (263) and (264). That is, as described above, when the address data AD 'and included in the address data AD _F and the control data DC ₁ supplied from the address ROM (31) coincide, the shift register (263), control is (264) Data DC
_The latch signal is supplied at the timing corresponding to the channel selection data CH included in ₁ , and the audio signal is taken out. The time-division multiplexed signal S from the CADA tuner (24)
_CA is supplied to the microcomputer (260), and the above-mentioned latch signal is formed based on this.

Further, the audio signals (the left signal and the right signal in the case of stereo, the same signal in the case of monaural) taken out from the shift registers (263) and (264) are respectively D / A converters (265) and (266). ), Volume adjustment volume (267),
Audio output terminal (29) via amplifiers (268) and (269)
And (29).

In the control panel (25), (25a)
Is a TV selection key, (25b) is a music selection key, (25c) is a channel up key, (25d) is a channel down key, (25e) is a channel display, (25f) is a volume control, and (25g ) Is the stewardess call key, (25
h) is the reading light key.

In this case, pressing the TV select key (25a) will select the TV channel and the channel up key (25c),
Press channel down key (25d) and microcomputer (260)
The reception channel of the TV tuner (23) can be changed by the control of. Further, the control data CD ₂ including the volume data VR which is set by the microcomputer (260) from the address data AD _F and channel selection data CH and operator for volume adjustment (25f) is generated, the control data DC ₂ is Transmitter (32)
After being modulated by the antenna (21) through the splitter (22)
Is supplied to.

Pressing the music selection key (25b) music channels is selected, the channel up key (25c), press the channel down key (25d) when the microcomputer (260) from the address data AD _F and channel selection data CH and volume control Control data DC ₂ including the volume data VR set by the operator (25f) for control is generated, and this control data DC ₂ is modulated by the transmitter (32) and then transmitted through the demultiplexer (22). It is supplied to the antenna (21). In this case, for example, the microcomputer (26
0) controls the signal processing circuit (27) and mutes the video signal.

When the stewardess call key (25g) is pressed, control data (address data A
_DF and stewardess call data) are generated, and this control data is supplied to the transmitter (32) and modulated, and then the leaky cable (11) is passed through the duplexer (22) and the antenna (21). Is supplied to. This control data is supplied from the leaky cable (11) to the receiver (8) through the branching filter (7) on the transmission side, demodulated, and then supplied to the encoder (3). Then, CPU within the encoder (3) based on the control data (not shown) the switch box (40) is controlled, flight attendant call lamp corresponding to the seat after the seat address data AD _F are shown (41a) Is made to emit light. Further, when the reading lamp key (25h) is pressed, the control data from the microcomputer (260) (the address data AD _F, including reading lights data) is generated, hereinafter the above stewardess call key (25 g) is pressed reading lamp corresponding to the seat after the seat indicated by the address data AD _F in the same manner (42a) is made to emit light with.

The terminal device (28B) is also configured in the same manner as the terminal device (20F). In this case, the address ROM (31) is written with unique address data AD _B indicating the seat in which this terminal device (20 B) is arranged, and this address data AD _B
Are supplied to the microcomputer of the decoder (26). (41
b) and (42b) are a stewardess call light and a reading light corresponding to the seat after the seat indicated by the address data AD _B , respectively.

Further, although not shown, other terminal devices are similarly configured.

In addition, most of the terminal devices (ideographic device (28),
The control panel (25) and the like are arranged on the back surface of the seat, and the audio output terminals (29) are arranged on the armrest portion (see FIG. 2).

This example is configured as described above, and the video signals output from the video tape recorders (1a) to (1c), the video tape recorders (1a) to (1c), and the compact disc players (2a) to (2d) are used. The output signal S _CA of the encoder (3), which is the time-division-multiplexed output audio signal, is modulated by the modulators (5a) to (5d) and added to form a frequency-multiplexed signal S _MF . Then, the frequency-multiplexed signal S _MF is supplied to the leaky cable (11) and transmitted to the receiving side.
Then, the terminal device on the receiving side can select a desired one from a plurality of video signals and audio signals transmitted as the frequency-multiplexed signal S _MF according to the key operation of the control panel (25).

In this case, for example, the control panel (2) of the terminal device (20F) arranged in the seat in front of the seat where the user is seated.
Press the TV selection key (25a) in 5) to select the TV channel, and the channel up key (25c),
Press the channel down key (25d) to change the receiving channel. Then, the video signal of the selected channel is output from the television tuner (23) and supplied to the display device (28) via the signal processing circuit (27), and the image by the video signal is displayed.

At this time, the control data DC ₂ including address data AD _F channel selection data CH and volume data VR from the microcomputer (260) of the decoder (26) is generated, the control data DC ₂ is modulated by the transmitter (32) Tanochi duplexer (22)
And is supplied to the leaky cable (11) via the antenna (21), and this data is supplied from the leaky cable (11) to the receiver (8) via the demultiplexer (7) on the transmission side and demodulated. Then, it is supplied to the master controller (4) via the encoder (3). Then, the master controller (4), the control address indicating the seat after the data DC seat indicated by the address data AD _F contained in the _second data AD _B is calculated, the address data AD _B from the master control (4) Control data DC ₁ including channel selection data CH and volume data VR is generated. Then, the control data DC ₁ is supplied to the encoder (3), multiplexed with the audio signal and the video signal, and supplied to the leaky cable (11). Then, each terminal device is retrieved control data DC ₁ decoder (26), the address and data AD _B included in the address data and control data DC ₁ supplied from the address ROM (31) are compared. In this case, since the address data supplied from the address ROM (31) of the terminal device (20B) arranged in the seat where the user is seated matches AD _B , the decoder (26) of the terminal device (20B) The shift registers (263) and (264) of
A latch signal is supplied from the microcomputer (260) at a timing corresponding to the channel selection data CH included in the control data DC ₁ , and an audio signal corresponding to the video signal output from the above-mentioned TV tuner (23) is taken out and the audio signal is output. It is supplied to the output terminal (29). Also, the volume (267) is the volume data included in the control data DC ₁ by the microcomputer (260).
The volume is controlled and controlled according to VR.

Therefore, the control panel (25) of the terminal device (20F) arranged in the seat in front of the seat in which the user is seated
When selecting a TV channel by key operation of, the image of the selected channel can be observed on the display device (28) of the terminal device (20F) and the sound of the terminal device (20B) arranged in the seat where the user is seated You can listen to the corresponding sound by connecting headphones (30) to the output terminal (29).

Also, when the user selects a music channel by key operation on the control panel (25) of the terminal device (20F) arranged in the seat in front of the seat on which the user is seated, the audio signal of the above-mentioned TV channel is transmitted. By the same operation, the audio signal of the selected channel is obtained at the audio output terminal (29) of the terminal device (20B) of the seat where the user is seated.
Therefore, the headphones (30) can be connected to the audio output terminal (29) of the terminal device (20B) to listen to the audio.
At this time, the signal processing circuit (27) is controlled by the microcomputer (260) in the terminal device (20F), the video signal is muted, and a black screen is displayed on the display device (28).

Also, when there is a channel that has not been selected for a certain period of time in all of the plurality of terminal devices, the master controller (4) on the transmission side causes the corresponding video tape recorders (1a) to (1d) and the compact disc player (2a). ) ~ (2d) are controlled and the video cassette or disc is replaced. At this time, the master controller (4) indicates the data CH'indicating a channel that has not been selected for a certain period of time and the contents (title, etc.) of the video signal or audio signal recorded in the exchanged video cassette or disc. Control data DC ₁ ′ including data TI
Is generated. The control data DC ₁ ′ is supplied to the encoder (3) and the leaky cable (11). Then, in each terminal device, the control data DC ₁ ′ is taken out by the decoder (26). Therefore, the signal processing circuit (27) is controlled by the microcomputer (260), and the character signal indicating the contents of the channel and the video signal based on the data CH ′ and TI included in the control data DC ₁ ′ is output from the tuner (23). The video signal from the tuner (23) is replaced with the video signal indicating the contents of the channel and the video signal, etc., which are superposed on the video signal or included in the control data DC ₁ ′ based on the data CH ′ and TI. Therefore, the display device of each terminal device (28)
A character (superimpose) or an image indicating the content of the video signal or the audio signal recorded on the channel which has not been selected for a certain period of time and the exchanged recording medium is displayed.

In addition, the stewardess call key (25
g), control data indicating that the reading light key (25h) has been pressed is modulated by the transmitter (32) and then supplied to the leaky cable (11) via the duplexer (22) and antenna (21). It Then, this data is supplied from the leaky cable (11) to the receiver (8) via the demultiplexer (7) on the transmission side, demodulated, and then supplied to the CPU of the encoder (3), as described above. The stewardess call lights (41a) and (41b) and the reading lights (42a) and (42b) corresponding to are controlled to emit light.

Thus, according to this example, a plurality of video signals, audio signals, etc. are frequency-multiplexed on the transmission side, and the leaky cable (1
1) is supplied to the receiving side terminal devices (20F), (20B), and the control data from the receiving side terminal devices (20F), (20B) is transmitted through the leaky cable (11). Since it is configured to be supplied to the device, the wiring can be simplified and the device can be simplified.

Further, according to this example, the video cassettes or discs of the video tape recorders (1a) to (1c) or the compact disc players (2a) to (2d) corresponding to the channels that have not been selected for a certain period of time in all the terminal devices are The contents of the video signal or audio signal recorded on the channel and new video cassette or disc that have not been selected for a certain period of time are automatically displayed and displayed on the display device (28) of each terminal device. The terminal device is supplied with a video signal and an audio signal that meet the needs of the user, and the user can immediately know the change of the video signal and the audio signal, so that the service for the user of the terminal device can be improved. Can be planned.

Further, according to this example, the image can be observed on the display device (28) of the terminal device (20F) arranged in the seat in front of the seat where the user is seated, and the seat where the user is seated You can listen to the sound by connecting the headphones (30) to the audio output terminal (29) of the terminal device (20B) arranged in
It is possible to avoid the inconvenience that the lead wire of the headphone (30) interferes with other passengers, and that the headphone (30) having a different lead wire is prepared every time the seat pitch (the distance between the front and rear seats) is changed. it can.

In the above-described embodiment, the master controller (4) collects the channel selection status of each terminal device based on the control data DC ₂ generated by the channel selection of each terminal device. However, the master controller (4) supplies control data requesting the data indicating the channel selection state to each terminal device, and based on this, the control data including the data indicating the channel selection state is mastered by each terminal device. In the case of a device configured to be supplied to the controller (4), aggregation processing may be performed based on this control data.

Further, in the above-mentioned embodiment, the master controller (4) processes the address data, but it may be processed when the control data DC ₂ is generated at the receiving side terminal. Further, although the above-described embodiments apply the present invention to an information transmission device in an aircraft, the invention can be similarly applied to an information transmission device in a vehicle such as a train, a bus, a theater, a stadium or the like. In the above embodiment, the terminal device (20
Although F) and (20B) are provided on the seat, they may be arranged near the seat, for example, on a table attached to the seat.

H Effects of the Invention According to the present invention described above, a plurality of video signals, audio signals, and the like are multiplexed and transmitted by a single signal transmission means, so that the wiring is simplified and the apparatus is simplified. Can be. Further, according to the present invention, the video signal or the audio signal from the video signal source or the audio signal source corresponding to the channel which has not been selected for a certain time in all the terminal devices is automatically exchanged, and the channel and the new signal are also exchanged. Since the content of the video signal or the audio signal is displayed on each terminal device, the service to the user of the terminal device can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram for explaining the same, and FIG. 3 is a specific configuration diagram of a main part of a terminal device. (1a) to (1c) are video tape recorders, (2a) to (2
d) is a compact disk player, (3) is a CADA encoder, (4) is a master controller, and (5a) to (5)
d) is a modulator, (8) is a receiver, (11) is a leaky cable, (20F) and (20B) are terminal devices, (21) is an antenna, (23) is a TV tuner, and (24) is a CADA tuner. ,
(25) is the control panel, (26) is the CADA decoder,
(27) is a signal processing circuit, (28) is a display device, (29) is an audio output terminal, (30) is headphones, and (31) is an address RO.
M, (32) is a transmitter.

Claims (1)

(57) [Claims] 1. A plurality of video signal sources, a plurality of audio signal sources, a computer, a video signal from the plurality of video signal sources, an audio signal from the plurality of audio signal sources, and the computer on the transmitting side. A control unit that multiplexes control data from, and supplies the multiplexed signal to the bidirectional signal transmission means,
It has a central control unit having a receiving section for receiving control data from the receiving side supplied from the bidirectional signal transmitting means and supplying it to the computer, and is supplied to the receiving side from the bidirectional signal transmitting means. A selection unit for selecting a predetermined video signal and audio signal from the multiplexed signal, a video display unit and an audio generation unit to which the video signal and audio signal selected by the selection unit are supplied, and the bidirectional signal transmission A separating section for separating control data from the transmitting side from the multiplexed signal supplied from the means, a unique address generating section, a selecting operation section, control data separated by the separating section, and the selecting operation section Signal and the address data from the unique address generating section to control the selecting section and generate control data to the transmitting side. The video signal source and the audio signal source reproduce the video signal and the audio signal from the recording medium. The video signal source and the audio signal source reproduce the video data and the audio signal from the recording medium. The recording medium can be exchanged, and the computer of the central controller aggregates the channel selection state of each terminal device based on the control data from the receiving side, and selects for a certain period of time. The recording medium of the video signal source or the audio signal source corresponding to the non-selected channel is exchanged under the control of the computer, and the data indicating the channel not selected for the certain period of time as the control data from the computer and the exchange. Data that contains the contents of the video signal or audio signal recorded on the recorded recording medium. Control data is generated, and the contents of the video signal or the audio signal recorded on the channel which has not been selected for the certain period of time and the exchanged recording medium are displayed on the image display unit of each terminal device. Information transmission equipment.