JPH0330352B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a device for transmitting television signals that differ from room to room, for example, to hotel rooms.

<Prior Art> Conventionally, each room in a hotel or the like receives a television signal other than the television signal transmitted from a broadcasting station, a so-called pay television signal. In such a case, the transmission of the video signal from the VTR is started at a predetermined time using the transmission line of the communal viewing device, so when a guest in a certain room tries to watch pay TV, there is a possibility that the transmission is not yet available. It may not have started or the transmission may have already started.

A technique to solve this problem is, for example, to install as many VTRs as there are rooms at the front desk, connect each of these VTRs to the television receiver in each room using separate lines, and Respond to each room request from the front desk.
One possibility is to activate the VCR.

<Problems to be Solved by the Invention> However, this technique had the problem of requiring a large number of VTRs. In other words, the probability that a request to operate a VCR will come from all rooms is generally very low, but with this technology, each
If the VTR is not connected to the television receiver in each room, it will not be possible to transmit the video from the beginning when a request is made from each room.
VCRs had to be prepared, increasing costs. Furthermore, since each VTR must be connected to the television receiver in each room, the transmission line of the communal viewing system cannot be used, and separate wiring must be done, which is a hassle. Moreover, the cost was increasing.

<Means for Solving the Problems> The present invention includes a central device installed, for example, at the front desk, and a plurality of terminal devices installed, for example, in each room.

The central device is connected to a plurality of video software playback devices that generate video signals by applying video software requested from the terminal device to unused video software from the beginning, and among these video software playback devices. A modulation means for supplying each channel signal, which is obtained by modulating a carrier wave signal with a different frequency with each video signal from an operating device, to each terminal device via a transmission line, and a terminal device that has requested video software playback. A modulated signal, in which a carrier wave different from the frequency of each channel signal is modulated by the address signal of the address signal and a channel instruction signal indicating the channel signal to be received by the terminal device that made the request, is sent to each terminal device via a transmission line. and transmitting means for supplying the information.

The terminal device includes a receiving means for receiving the modulated signal;
demodulating means for demodulating a channel signal selected by a channel selection signal among each channel signal; and a received channel instruction signal instructs when the received address signal matches the address assigned to itself. a control means for supplying a channel selection signal to the demodulation means so that the demodulation means demodulates the channel signal; and confirmation signal generating means for supplying a reception confirmation signal changed to the state of 1 to the central device via the transmission line.

Further, the central device includes determining means for determining whether the reception confirmation signal is in the first state or at the second level.

[Operation] According to the present invention, when there is a request to send specific video software from the terminal device side to the central device side, for example by telephone, the central device side sends the requested software to the video software. Put it on a playback device,
Generate a video signal. This video signal is converted into a channel signal by a modulation means and transmitted to each terminal device via a transmission line. On the other hand, a modulated signal whose carrier wave is modulated by the address signal of the terminal device that requested transmission of the video signal and a channel signal obtained by converting the requested video signal is transmitted to each terminal device.

The terminal device that made the request receives the modulated signal and the address signal matches the address assigned to itself, so it uses the demodulating means to transmit the channel signal indicated by the channel instruction signal included in the received modulated signal. A channel selection signal is generated to the demodulation means so that the channel selection signal can be received by the demodulation means. Further, the level of the reception confirmation signal is changed from the first state to the second state and sent to the central device. In the central device, the determining means confirms whether the sent reception confirmation signal is in the second state, and if it is in the second state, it is determined that the signal has been received and the process ends.

<Embodiment> In this embodiment, as shown in FIG.
and each terminal device 4. The central device 2 is installed, for example, at the front desk, and each terminal device 4 is installed in each room. Central device 2 and each terminal device 4
and is connected via a transmission line 6 for a joint viewing and viewing device.

The central device 2 includes a center device 8 and a plurality of VTRs, for example, 16 VTRs 10a to 10p. Of these VTRs 10a to 10p, only those to which a drive signal is supplied from the center device 8 operate and supply a video signal to the modulator 12. When the video signal is supplied from the VTR 10a, the modulator 12 transmits the A channel signal to the VTR 10a.
When a video signal is supplied from VTR 10p, it modulates the B channel signal, and when a video signal is supplied from the VTR 10p, it modulates the P channel signal to generate a pay television signal. These pay television signals are mixed at the head end 14 with general television broadcast signals from broadcast stations received by the antenna 16. Note that the A to P channels are selected from, for example, a midband between the 3rd channel and the 4th channel.

The center device 8, as shown in FIG.
It has a CPU 18, an FSK transmitter 20, a keyboard 22, and a comparator 24. The keyboard 22 is
It instructs the CPU 18 which of the VTRs 10a to 10p to operate and which terminal device 4 to supply the video signal of the activated VTR. According to this instruction, CPU18 was instructed
The address signal of the terminal device 4 that supplies the drive signal to the VTR and also supplies the video signal to the FSK transmitter 20, and the channel that instructs which VTR is supplying the video signal, that is, how many channels should be received. and an instruction signal.
Further, when a VTR end signal is supplied, this and an address signal are supplied to the FSK transmitter 20.
When the FSK transmitter 20 is supplied with the address signal and the channel instruction signal, it transmits a signal obtained by frequency shift modulating a signal with a lower frequency than the general television signal and each channel signal, and also transmits the address signal and the VTR signal. When the end signal is supplied, it similarly sends out a frequency shift signal. This modulated signal and the signal from the head end 14 are combined into a mixing section 2.
6 and supplied to each terminal device 4 via the transmission path 6 of the joint viewing and viewing device. The comparator 24 connects the terminal device 4 to the transmission path 6 of the joint viewing device and the mixing unit 2.
When the DC voltage supplied through 6 is at L level, an output signal at H level is supplied to CPU 18.

Each terminal device 4 has a duplexer 28. As shown in FIG.
0, and a bandpass filter 34 for supplying only the frequency-shifted signal from the center device 8 to the receiver 33.
and a low-pass filter 38 for supplying the DC signal from the transmitter 36 to the central device 2.

The two-way divider 30 sends the output signal of the head end 14 extracted by the splitter 28 to a PLL converter 39.
and the amplifier 40.

The receiver 33 demodulates an address signal and a channel instruction signal from the frequency shift signal extracted by the duplexer 28 and supplies the demodulated address signal and channel instruction signal to the CPU 42 .

When the address assigned to this terminal device 4 by the deep switch 44 and the address signal demodulated by the receiver 33 do not match, the CPU 42 sends the output side of the amplifier 40 and the output side of the PLL converter 39 to the television receiver. The relay 48 interposed between the amplifier 40 and the television receiver 46 is switched to a state where the output side of the amplifier 40 is connected to the television receiver 46, and the PLL converter 39 is controlled to be in a stopped state. Further, when the demodulated address signal and the address from the deep switch 44 match, the CPU 42 switches the relay 48 so that the output side of the PLL converter 39 is connected to the television receiver 46, and also switches the PLL converter 39
9, and the PLL converter 39 converts the pay television signal of the channel specified by the channel instruction signal into the television signal of a predetermined specific channel.
A channel selection signal is provided to PLL converter 39 and transmitter 36 is activated.

The transmitter 36 uses an NPN transistor 50, as shown in FIG. 26 to the comparator 24 of the center device 8.

According to this embodiment, for example, when a guest in a certain room requests the front desk to broadcast a specific video, the front desk displays an empty VTR, for example.
The videotape containing the requested video is played on the VTR 10b. And keyboard 2
Step 2 instructs the CPU 18 to operate the VTR 10b and the address assigned to the terminal device 4 in the room that requested the video.
This causes the CPU 18 to operate the VTR 10b to generate a video signal from the first portion of the videotape, and to supply the FSK transmitter 20 with an address signal and a channel indication signal.
The video signal from the VTR 10b is sent to the modulator 12
This B channel modulated signal can be used as a general television signal or already in the modulator 12.
The mixed signal is supplied to the mixing section 26 via the head end 14 along with other channel signals sent from the source.
Further, the FSK transmitter 20 performs frequency shift modulation on the address signal and the channel signal, and supplies this frequency shift signal to the mixing section 26 . The mixing section 26 is
The B channel signal and the frequency shift signal are mixed and this mixed signal is supplied to each terminal device 4 via the transmission line 6 for the communal viewing device.

In each terminal device 4, a branching filter 28 supplies a B channel modulated signal, a general television signal, and other channel signals to a two-way splitter 30. Further, the duplexer 28 extracts the frequency shift signal and supplies it to the receiver 33. The receiver 33 demodulates an address signal and a channel instruction signal from this frequency shift signal and supplies them to the CPU 42. The CPU 42 determines whether the demodulated address signal matches the address given by the deep switch 44, but the CPU 42 in the room that made the request switches the relay 48.
The output side of the PLL converter 39 is connected to the television receiver 46, and a channel selection instruction signal is supplied to the PLL converter 39 to select the B channel according to the channel instruction signal, thereby converting the B channel into a predetermined channel. make it work like this. This allows the requested video to be viewed from the beginning on the television receiver 46 in the room where the request was made. At the same time, the CPU 42 operates the transmitter 36 to provide an L level voltage to the comparator 24 of the center device 8 . As a result, the comparator 24 provides an H level signal to the CPU 18, and the CPU 18 confirms based on this that the video has definitely been supplied to the terminal device 4 in the requested room.

Note that among the terminal devices 4 in the rooms whose addresses do not match, the relay 48 maintains the state in which the output side of the amplifier 40 is connected to the television receiver 46 for those receiving general television signals. General television signals continue to be received. In addition, in the terminal device 4 in the room that has already issued a request for another video, the relay 48 connects the PLL converter 39 to the television receiver 46, but the CPU 42 does not change the selected channel to the PLL converter. 39, the reception of the video currently being received continues.

When the requested video ends, the CPU 18 of the center device 8 supplies the FSK transmitter 20 with an address signal and a video end instruction signal. These signals are supplied to the terminal device 4 in the requested room in the same manner as described above, and the CPU 42 stops the PLL converter 39 and switches the relay 48 so that it can receive general television broadcast signals.

In the above embodiment, a VTR is used, but a video disc may also be used. Although general television signals were also transmitted at the same time, it is not necessary to transmit them. Furthermore, relay circuit 4
8 was used, but a mixing section may be used instead. In that case, you can also receive general television signals by switching channels.

<Effects> As described above, according to the present invention, when a request for video software is received from the terminal device side, when the video software is played on an available video playback device, the video software is transmitted to the terminal device that requested the video software. Only the video software can supply the video signal from the beginning. Moreover, since the transmission line of the communal viewing equipment can be used as is to play the video software from the beginning only to the terminal device that has received the request, it is possible to use the same number of videos as there are rooms in a hotel etc. There is no need to prepare a software playback device or to connect these video software playback devices and television receivers in each room individually. Therefore, there is no need for special wiring, and there is almost never a request to stream video from all rooms at the same time, making it possible to reduce the number of VTRs installed and lower costs. Furthermore, the reception confirmation signal used to notify the central device that it has been received from the terminal device is the signal that changes the DC voltage level from the first state to the second state when it is actually received. Therefore, both the structure of the confirmation signal generation means and the structure of the determination means for receiving this reception confirmation signal on the central device side and determining the reception confirmation signal can be simplified.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a television signal transmission device according to the present invention, FIG. 2 is a block diagram of a center device of the same embodiment, and FIG. 3 is a block diagram of a duplexer of the same embodiment. FIG. 4 is a circuit diagram of the transmitter of the same embodiment. 2...Central device, 4...Terminal device, 6...Address signal sending means, 10a to 10p and 12...
...Television signal source.

Claims (1)

[Claims] 1. A central device comprising: a central device; and a plurality of terminal devices connected to the central device via transmission lines and each having a different address assigned; It has a video software playback device, and any unused video software playback device can be used to play any video software requested from any of the above terminal devices, and the video software can be played from the beginning. a video software playback source that generates a video signal, and a carrier wave signal having a different frequency corresponding to each of the video software playback devices, and these carrier wave signals are transmitted by the video signal of the corresponding video software playback device. a modulation means that modulates and outputs them as channel signals of different frequencies; an address signal of the terminal device that has requested video software playback; means for generating a channel instruction signal for instructing a channel signal of a frequency corresponding to the channel signal; transmitting means for supplying the signal to each terminal device via the transmission line, the terminal device comprising: receiving means for receiving the modulated signal; and the received address signal matches the address assigned to the terminal device. control means for supplying the received channel instruction signal as a channel selection signal to the conversion means; the converting means converting the channel signal indicated by the channel instruction signal into the television signal of the channel having the predetermined frequency; reception confirmation signal generating means for supplying the reception confirmation signal changed from the state to the second state to the central device via the transmission line; A television signal transmission device comprising determining means for determining whether it is in a first state or a second state.