JPH0683384B2 - Video and audio signal receiving station equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention transmits a video / audio signal from a transmitting station to a plurality of receiving stations in a broadcast format, and connects / disconnects (ON / OFF) the video / audio signal for each receiving station. OFF) The present invention relates to a video / audio signal receiving station device in a control system.

“Prior Art” As shown in FIG. 4, in the conventional system of this type, the video input and the audio input are supplied to the video / audio synthesizing device 12 through the video / audio switching device 11 at the transmitting station, and the video synthesized by this is supplied. The audio signal is broadcast. At the plurality of receiving stations A, B, C, the broadcast video / audio signal is received, separated by the video / audio separation device 13 into a video signal and an audio signal, and output through the video / audio switching device 14.

The control for connecting / disconnecting the video / audio signal is performed by the control center 15 through the respective control lines 16 for controlling the video / audio switching devices 11 and 14 respectively. In this way, the computer installed in the control center 15 controls ON / OFF of the video / audio signal of each station online.

[Problems to be Solved by the Invention] As described above, in the related art, a separate control line is required for controlling connection / disconnection of a video / audio signal. For this reason, it was not possible to flexibly deal with the increase or decrease or change in the number of receiving stations. I had no choice but to visit the current receiving station to check if the connection / disconnection was normal.

[Means for Solving the Problems] According to the present invention, the control signal is detected from the video / audio signal received by the receiving means, and the receiving means and the output side are connected in accordance with the connection / disconnection instruction of the detected control signal. The switch means inserted between the switch means is controlled, and the video signal separated from the received audiovisual signal on the output side of the switch means is monitored by the monitor detecting means, and the normal video signal is detected by the monitor detecting means. Then, the audio signal separated from the received video / audio signal on the output side is transmitted to the telephone line, and if a normal video signal is not detected, the transmission of the audio signal to the telephone line is cut off. Means are provided.

[Embodiment] FIG. 1 shows a system configuration including a receiving station apparatus according to the present invention. In the transmitting station, the control signal from the control device 21 on the transmission side is switched to audio input by the switch 22 and supplied to the video / audio synthesizer 12. The control signal is for instructing connection / disconnection of the transmission of the video / audio signal.

In the receiving stations A, B, and C, the output of the video / audio separating device 13 is supplied to the control device 23 on the receiving side, and the control device 23 detects the control signal and connects / disconnects the video output and the audio output according to the instruction. Is controlled.

Next, a specific example of the control devices 21 and 23, which are the essential parts of the present invention, will be described with reference to FIG. The operator inputs the ON-OFF condition (ON-OFF time) for each receiving station from the ON-OFF condition input unit 24 in the control device 21 of the transmitting station. Based on the input conditions, the ON-OFF control unit 25 causes the control signal generation unit 26 to connect (ON) and disconnect (OF) the signal of the target receiving station at the set time.
F) A control signal consisting of either signal is generated as a digital signal such as MF signal (multi-frequency signal) or FS modulation (frequency shift), and at the same time the switch 22 is switched to send the control signal to the audio signal line. To do. The control signal is, as shown in Fig. 3, the receiving station identification signal part for identifying the receiving station such as the code number of the receiving station, and the ON-OFF control signal part for instructing connection (ON) or disconnection (OFF). And consists of.

The control signal decoder unit 27 is connected to the audio signal line separated in the control device 23 on the receiving side, and the control signal decoder unit 27 is connected.
The control signal is decoded by and the output is
When the receiving station specific signal part in the control signal is detected and the code number of the receiving station is detected, the ON-OFF control signal part in the control signal is switched to the audio / video ON-OFF relay. It is supplied to the control unit 29, and video / audio ON / OFF relay control unit
29 is relay contact 29a, 29b when ON-OFF control signal part is ON
When the ON / OFF control signal is OFF, the relay contacts 29a and 29b are turned OFF to output the video output and audio output from the video / audio separation device 13 by turning on the Shut off.

A video signal monitoring / detecting unit 31 is connected to the rear stage of the relay contact 29a inserted in the video output line of the video / audio separating device 13, and the video signal monitoring / detecting unit 31 detects the fluctuation of the video signal level and synchronization, and the detected value. When the value exceeds a preset value, the audio switch of the audio signal SW unit 32 is turned off. Audio signal SW section 32
Controls whether the voice output is branched and supplied to the telephone receiving unit 33. The telephone call receiving unit 33 is a voice signal switch by telephone operation.
Connect the part 32 to the telephone line. Therefore, if the transmitted video signal is good, the voice switch of the voice signal SW section 32 is turned on, the voice signal is monitored by the telephone, and if the transmitted video signal is bad, nothing is heard from the telephone receiving section 33. Absent.

In the above, it was transmitted wirelessly from the transmitting station to the receiving station,
The present invention can also be applied to the case where all stations broadcast via a transmission path connected in a bus shape. Although the control signal is sent by switching it to the audio signal, it may be sent by switching it to the video signal.
ON-OFF condition input section 24, ON-O in the control device 21 on the transmission side
The FF control unit 25 may be omitted, and the operator may manually switch the switch 22 to send the control signal. When connecting / disconnecting the video / audio signals to a plurality of receiving stations at the same time, a special signal of a non-identifying operation may be used as the receiving station specifying signal portion in the control signal. Further, in a system in which each receiving station always operates simultaneously, the receiving station specifying signal section may be omitted as a matter of course. Similarly, when there is only one receiving station, the receiving station specifying signal part in the control signal can be omitted.

"Effects of the Invention" As described above, according to the present invention, the control signal is detected by the receiving station to connect / disconnect the video / audio signal. Therefore, no control line is required. You can flexibly deal with changes and changes.

Also, by connecting the transmitting station and the receiving station with a telephone line, the signal confirmation unit can confirm the connection / disconnection of the video / audio signal by telephone, and the maintenance person does not have to go to the receiving station one by one, saving time and cost. It can be reduced and work efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a system configuration in which the receiving station device of the present invention is used, and FIG. 2 is a block diagram showing an example of embodying the control devices 21 and 23 which are the main parts of the present invention. FIG. 4 is a diagram showing a configuration example of a control signal, and FIG. 4 is a block diagram showing a conventional video / audio remote control system.

Claims (1)

[Claims] 1. A video / audio signal receiving station device in a system for transmitting a video / audio signal from a transmitting station to a plurality of receiving station devices in a broadcast format, and controlling connection / disconnection of the video / audio signal for each receiving station device, Receiving means for receiving the video / audio signal, means for detecting a control signal from the received video / audio signal, and instructions for connecting / disconnecting the detected control signal,
Means for controlling the switch means inserted between the receiving means and the output side, and monitoring and detecting means for monitoring the video signal separated from the received audiovisual signal on the output side of the switch means, When a normal video signal is detected by the monitoring detection means, an audio signal separated from the received video / audio signal on the output side is sent to the telephone line, and if the normal video signal is not detected, the audio signal is output. Means for cutting off the transmission to the telephone line.