JP3002000B2 - Video / audio signal separation circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video / audio signal separating circuit for separating and monitoring a video / audio signal from a composite output of a video / audio synthesizing section of a television transmitting apparatus.

[0002]

2. Description of the Related Art Conventionally, in a television transmitting apparatus, when synthesizing and outputting a video signal and an audio signal, an output transmission line is used to monitor that each section of the apparatus output is operating normally. A monitoring signal is extracted by a directional coupler or the like provided in each unit, and monitoring is performed by a video monitor device and an audio monitor device. FIG. 2 shows the system diagram.

In FIG. 2, reference numeral 1 denotes a video transmitting unit, 2 denotes an audio transmitting unit, and video and audio signals output from the transmitting units 1 and 2 are synthesized and output by a synthesizing unit 3 called a CIN diplexer. . Directional couplers 4 to 7 for extracting transmission signals are provided on output transmission lines of the transmitting units 1 and 2 and the combining unit 3 respectively.

The synthesized signal extracted by the directional coupler 6 is sent to a video separation filter 8, where the video signal is separated. This video signal is sent to the video monitor 9 together with the original video signal extracted by the directional coupler 4, and is compared with the original video signal. The synthesized signal extracted by the directional coupler 7 is sent to the audio separation filter 10, where the audio signal is separated. This audio signal is sent to the audio monitoring device 11 together with the original audio signal extracted by the directional coupler 5, and compared with the original audio signal.

[0005] However, the conventional video /
Since the sound separation circuit is affected by the amplitude distortion and delay distortion of the filter used for each signal separation, the characteristics of the monitor signal are different from the characteristics of the actually transmitted television signal (synthesized signal). There was a problem that accurate monitoring could not be performed.

[0006]

As described above, the conventional video / audio separation circuit is affected by the amplitude distortion and the delay distortion of the filter used for each signal separation. However, there is a problem in that the characteristics are different from those of the television signal (synthesized signal) transmitted to the computer and accurate monitoring cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and separates a video signal and an audio signal from a monitor signal extracted from a video / audio synthesizing unit of a television transmitting apparatus without deteriorating characteristics. It is an object of the present invention to provide a video / audio signal separation circuit that can perform the operation.

[0008]

In order to achieve the above object, the present invention provides a video / audio synthesizing unit which combines a video signal output from a video transmitting unit and an audio signal output from an audio transmitting unit. A video / audio separation circuit used for a monitor output of the television transmission device, wherein an inverse-phase video signal generation circuit that generates an inverse-phase video signal by extracting an output of the video transmission unit and inverting a phase; A first synthesizing circuit for obtaining an audio monitor signal by extracting an output of an audio synthesizing unit and synthesizing the negative-phase video signal, and a negative-phase audio by extracting the output of the audio transmitting unit and inverting the phase; A negative-phase audio signal generation circuit for generating a signal;
A second synthesizing circuit for obtaining a video monitor signal by extracting an output of the audio synthesizing unit and synthesizing the opposite-phase audio signal.

[0009]

In the video / audio separation circuit having the above configuration, the output of the video transmission section is inverted to generate a reverse-phase video signal, and the reverse-phase video signal is subjected to reverse-phase synthesis with the output of the video / audio synthesis section. To generate a reverse-phase audio signal by inverting the phase of the output of the audio transmission section, and performing reverse-phase synthesis of the negative-phase audio signal with the output of the video / audio synthesis section to convert the video monitor signal. To separate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIG. However, in FIG. 1, the same portions as those in FIG. 2 are denoted by the same reference numerals, and different portions will be mainly described here.

FIG. 1 shows the structure of the apparatus. The original video signal extracted by the directional coupler 4 is divided into two by a distributor 12, one of which is sent to a video monitor 9 as it is, and the other is an audio signal. It is sent to the separation circuit 13. The circuit 13 includes a phase inverting circuit 131 and a synthesizing circuit 132. The phase inverting circuit 131 inverts the phase of the original video signal to generate an inverted-phase video signal, and then supplies the inverted video signal to one input terminal of the synthesizing circuit 132. It has become.

The original audio signal extracted by the directional coupler 5 is divided into two by a distributor 14, one of which is sent to the audio monitor 11 as it is, and the other is a video signal separating circuit 1.
Sent to 5. This circuit 15 is composed of a phase inversion circuit 151 and a synthesizing circuit 152. The phase inversion circuit 151 inverts the phase of the original audio signal to generate an inverted phase audio signal, and then supplies it to one input terminal of the synthesizing circuit 152. It has become.

On the other hand, the combined signal extracted by the directional coupler 7 is divided into two by the divider 16, one of which is to the combining circuit 132 of the audio signal separating circuit 13, and the other is to the combining circuit 152 of the video signal separating circuit 15. Supplied to The output of the synthesizing circuit 132 of the audio signal separating circuit 13 is
The output of the synthesizing circuit 152 of the video signal separation circuit 15 is sent to the video monitor device 9. The operation of the above configuration will be described below.

First, the audio signal separating circuit 13 inverts the phase of the original video signal extracted by the directional coupler 4 via the distributor 12 by the phase inverting circuit 131 to generate a reverse-phase video signal. The phase video signal is inversely synthesized by the synthesis circuit 132 with the video / audio synthesis signal. As a result, the video signal component of the composite signal is canceled with the original video signal, and only the audio signal is extracted. The audio signal thus separated is supplied to the splitter 13.
Are sent to the audio monitoring device 11 together with the original audio signal output from the, and are compared and referenced. In this case, since no filter is used, there is no influence of filter characteristics as in the related art.

The video signal separation circuit 15 inverts the phase of the original audio signal extracted by the directional coupler 5 via the distributor 14 by the phase inversion circuit 151 to generate an inverted phase audio signal. The phase audio signal is inversely synthesized by the synthesis circuit 152 with the video / audio synthesis signal. As a result, the audio signal component of the synthesized signal is canceled with the original audio signal, and only the video signal is extracted. The video signal separated in this way is supplied to the distributor 12
Is sent to the video monitor device 9 together with the original video signal output from the device, and is compared and referenced. Also in this case, since no filter is used, there is no influence of the filter characteristics as in the related art.

Therefore, if the video / audio signal separation circuit having the above configuration is used, the video signal and the audio signal can be separated from the monitor signal extracted from the video / audio synthesizing unit 3 without deteriorating the characteristics. .

[0017]

As described above, according to the present invention, a video signal and an audio signal can be separated from a monitor signal extracted from a video / audio synthesizing section of a television transmitting apparatus without deteriorating characteristics. -An audio signal separation circuit can be provided.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing one embodiment of a video / audio signal separation circuit according to the present invention.

FIG. 2 is a block circuit diagram showing a configuration of a television transmitter to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Video transmission part, 2 ... Audio transmission part, 3 ... Video / audio synthesis part, 4-7 ... Directional coupler, 8 ... Video separation filter, 9
... video monitor device, 10 ... audio separation filter, 11 ... audio monitor device, 12, 14, 16 ... distributor, 13 ... audio signal separation circuit, 131 ... phase inversion circuit, 132 ... synthesis circuit, 15 ... video signal separation circuit , 15 ... phase inverting circuit, 1
52: synthesis circuit.

Claims (1)

(57) [Claims] 1. A video / audio separation circuit used for a monitor output of a television transmission device that combines and outputs a video signal output from a video transmission unit and an audio signal output from an audio transmission unit in a video / audio synthesis unit. A negative-phase video signal generating circuit that generates an opposite-phase video signal by extracting the output of the video transmitting unit and inverting the phase, and extracting the output of the video / audio synthesizing unit to generate the negative-phase video signal. A first synthesizing circuit for obtaining an audio monitor signal by synthesizing, an inverse audio signal generating circuit for extracting an output of the audio transmitting unit and inverting a phase to generate an inverse audio signal;
A second synthesizing circuit for obtaining an image monitor signal by extracting an output of an audio synthesizing unit and synthesizing the opposite-phase audio signal.