JPH07184132A - Television signal receiver - Google Patents

Abstract

PURPOSE:To allow the receiver to receive a broadcast of another channel while a commercial is broadcast with a simple configuration, by using a discrimination signal from an audio multiplex mode discrimination means so as to switch a channel selection means to another channel only when the discrimination signal is a stereo signal. CONSTITUTION:When a commercial is broadcast through a channel 1, an audio multiplex mode discrimination circuit 12 connecting to a tuner B9 detects a stereo broadcast of an audio signal in the commercial broadcast. Since a discrimination signal 13 changes from a monaural or dual audio signal into a stereo signal, the signal 13 is given to a channel selection circuit A3 as a control signal to switch a tuner A2 from the channel 1 into a channel 2. In this case, since a tuner B9 remains to the channel 1, when a commercial broadcast of the channel 1 is finished, the audio multiplex mode discrimination circuit 12 provides an output of the discrimination signal 13 by the monaural or dual audio signal into a stereo signal again to allow the tuner A2 to receive the channel 1 again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television signal receiving apparatus adapted to automatically switch to another channel or another input source during commercial broadcasting.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing a channel selection circuit and a video / audio demodulation circuit of a general television receiver, wherein 1 is an antenna for receiving VHF and UHF band television signals, and 2 is an antenna. A tuner for converting a received signal into a constant intermediate frequency and selecting a desired channel, 3 is a tuning circuit for generating a signal for selecting the desired channel by the tuner 2, and 4 is an image from an output signal of the tuner 2. A video intermediate frequency signal processing circuit for extracting a frequency signal, 5 is an audio intermediate frequency signal processing circuit for extracting an audio intermediate frequency signal, and 6 is an output signal of the audio intermediate frequency signal processing circuit 5 for each of the left and right audio signals. An audio multiplex demodulation circuit for demodulation, 7 is a video signal output from the video intermediate frequency signal processing circuit 4, and 8 is an audio signal output from the audio multiplex demodulation circuit 6.

Next, the operation will be described. The tuner 2 and the tuning circuit 3 select a desired channel signal from the television signal received by the antenna 1. From the output signal, the video intermediate frequency signal processing circuit 4 extracts the baseband video signal 7.

The voice passes through the voice intermediate frequency signal processing circuit 5 and the voice multiplex demodulation circuit 6, is separated into left and right baseband signals, and is taken out as a voice signal 8. At this time, the audio multiplex demodulation circuit 6 determines three modes of monaural, stereo, and dual audio based on the frequency of the identification signal of the audio multiplex signal.

By the way, in recent television broadcasting,
Commercials are stereo broadcasts, and Western movies are dual audio. 2
Many national language broadcasts and dramas are monaural. Therefore, by utilizing the fact that the mode of this audio multiplex is changed, it is possible to detect a commercial broadcast broadcasted in a Western picture or a drama.

As an example of utilizing such a mode change, there is proposed a television receiver disclosed in Japanese Patent Laid-Open No. 4-172808, which automatically switches to a back program only during a commercial period.

[0007]

However, in the device of the prior art, since two circuits for demodulating the video signal and the audio signal are required, the circuit is complicated and expensive. .

The present invention eliminates the above-mentioned drawbacks, and provides a television signal receiving apparatus having a simple structure and automatically switching to a back program from another channel or another input source during a commercial broadcasting period. It is what

[0009]

A television signal receiving apparatus according to the present invention comprises a first channel selecting means, and a video signal and an audio signal for demodulating a video signal and an audio multiplex signal from the first channel selecting means. A signal processing means, a second channel selecting means, and an audio multiplex mode determining means for determining whether the audio multiplex mode of the audio signal from the second channel selecting means is monaural, dual audio, or stereo. Only while the discrimination signal from this discrimination means is stereo, the first channel selection means is switched to another channel by this discrimination signal.

Another television signal receiving apparatus according to the present invention is a channel selecting means, a video signal and audio signal processing means for demodulating a video signal and an audio multiplex signal from the channel selecting means, and a demodulated audio signal. Is mono or dual voice,
Means for discriminating between stereo and outputting an audio signal mode discrimination signal, the video signal and audio signal, an external video,
An input switching means for switching and outputting a video signal and an audio signal of another input source such as a BS and a control means for controlling the input switching means are provided, and only while the audio mode discrimination signal is stereo. The input switching means is switched to another input source side via the control means by the discrimination signal.

[0011]

In the television signal receiving apparatus according to the present invention, the audio mode of the television signal received by the second channel selecting means is determined by the audio multiplex mode determining means, and a commercial broadcast normally sent in stereo is broadcast. By detecting and switching the first channel selection means to another channel by the discrimination signal, the program of another channel is automatically received while the commercial is being played.

Alternatively, the second channel selecting means and the like may be omitted, and the audio multiplex mode discrimination signal may be taken out from the audio multiplex demodulation circuit, and the input switching circuit may be operated by this, so as to operate the external video, BS, etc. during the commercial period. By switching to the input source, the other input source is the back program while the commercial is being played.

[0013]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, since 1 to 8 are the same as those shown in FIG. 3, the same reference numerals are given and description thereof is omitted. 9 is a tuner B different from tuner A3, 10 is this tuner B
A tuning circuit B that outputs a tuning signal to 9 and that can receive at least a television audio frequency is a tuner B.
An audio intermediate frequency signal processing circuit B for performing audio signal processing from the output of 9, an audio multiplex mode determination circuit for determining an audio multiplex mode from the output signal of the audio intermediate frequency signal processing circuit B11, and an audio multiplex mode determination circuit 12 This is a discrimination signal of the voice multiplex mode output from the channel selection circuit A3 and is supplied as a control signal to the channel selection circuit A3.

Next, the operation will be described. While watching a program that is being broadcast on a certain channel, for example, channel 1 in monaural or dual audio, another channel, for example channel 2 that has been preset only during the commercial period of this program.
The operation when trying to see is as follows.

Now, when a commercial is broadcast on channel 1, a stereo broadcast of the commercial audio signal is performed.
The audio multiplex mode discrimination circuit 12 connected to the tuner B9 detects and the discrimination signal 13 is changed from monaural or dual voice output to stereo output. Therefore, this is given to the channel selection circuit A3 as a control signal and Switch A2 from channel 1 to channel 2. At this time, since the tuner B9 still receives the channel 1, when the commercial of the channel 1 is finished, the voice multiple mode discriminating circuit 12 again outputs a discriminating signal in monaural or double voice, and the discriminating signal 1
The channel selection device A3 is controlled by 3 to return the tuner A2 to the channel 1 again. Therefore, it is possible to automatically switch to another channel only during the commercial period in which channel 1 is being viewed.

Here, the audio intermediate frequency signal processing circuit B11
The audio multiplex mode discriminating circuit 12 is for the purpose of only discriminating the audio multiplex mode, and no video signal processing circuit is required in this series. Therefore, unlike the conventional device, the video signal demodulating circuit and the audio signal demodulating circuit are provided. The configuration can be remarkably simplified as compared with the case where two systems are provided.

Example 2. FIG. 2 shows another embodiment of the present invention. In Example 1, the main tuner A
In addition to No. 2 and the tuning circuit A3, an auxiliary tuner B9, a tuning circuit B10, an audio intermediate frequency signal processing circuit B11, and an audio multiplex mode discrimination circuit 12 are provided. 9 to 12 in the series are omitted and the configuration is as follows.

In FIG. 2, 1 to 8 are the same as those in FIG. Reference numeral 14 is a video signal input from an external video input terminal, 15 is an audio signal thereof, 16 is a BS receiving circuit in a television receiver having a satellite broadcast (hereinafter referred to as BS) receiver, and 17 is an output BS video signal. , 18
Is a BS audio signal, 19 is the terrestrial television side,
An input switching circuit for switching the video signal and the audio signal to either the external video side or the BS side, 20 is a control for receiving the audio multiplex mode determination signal 13 obtained from the audio multiplex demodulation circuit 6 and controlling the input switching circuit 19. Circuit.

In such a case, when the tuner 2 is being received by the channel selection circuit 3 in tune with the channel 1, when the commercial broadcast starts in this program, it is notified that the audio multiplex mode is stereo. Circuit 6
Discriminates and inputs the discrimination signal 13 to the control circuit 20,
The input switching circuit 19 automatically switches the video signal and the audio signal to the external video or BS, respectively. And
When the commercial of the terrestrial TV channel 1 ends, the audio multiplex demodulation circuit 6 determines that the stereo has switched to monaural or dual audio, and the determination signal 13 is input to the control circuit 20 to broadcast the program on the ground. The input switching circuit 19 is automatically switched to return to the wave television channel 1. The input source other than the terrestrial television need not necessarily have both the external video and the BS, and either one may be provided, or another input source may be provided. It should be noted that in the first and second embodiments, it is easy to configure so that the function of watching the back program during the commercial period is canceled by the user's selection.

[0020]

As described above, according to the present invention, the commercial broadcast of the received television program is discriminated by the audio multiplex mode discriminating circuit provided in the sub-tuner and the sub-selection circuit, and the discriminating signal is used for the main tuner and the main selection. Since the station circuit is switched to a program on another channel to receive another broadcast during the commercial period, the video signal processing circuit can be configured in one system, and the circuit configuration is simplified.

Further, the audio multiplex mode discrimination signal is taken out from the audio multiplex demodulation circuit of the terrestrial television receiver, and the input signal is switched to an external video or other input source such as BS during the commercial period by the discrimination signal. Therefore, it is possible to watch the back program during the commercial period with a simpler structure.

[Brief description of drawings]

FIG. 1 is a block diagram showing a channel selection circuit according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a tuning circuit according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a channel selection circuit of a general television receiver.

[Explanation of symbols]

 1 antenna 2 tuner 3 channel selection circuit 4 video intermediate frequency signal processing circuit 5 audio intermediate frequency signal processing circuit 6 audio multiplex demodulation circuit 7 television video signal 8 television audio signal 9 tuner 10 channel selection circuit 11 audio intermediate frequency signal processing circuit 12 audio Multiplex mode determination circuit 13 Audio multiplex mode determination signal 14 External video input video signal 15 External video input audio signal 16 BS reception circuit 17 BS video signal 18 BS audio signal 19 Input switching circuit 20 Control circuit

Claims (2)

[Claims] 1. A first channel selecting means, a video signal and audio signal processing means for demodulating a video signal and an audio multiplex signal from the first channel selecting means, a second channel selecting means, and a second channel selecting means. And a voice multiplex mode discriminating unit for discriminating whether the voice multiplex mode of the voice signal from the channel selecting unit 2 is monaural, dual voice, or stereo, and only while the discriminating signal from the discriminating unit is stereo. , The first signal based on this determination signal
A television signal receiving apparatus, characterized in that the channel selecting means of (1) is switched to another channel. 2. A channel selecting means, a video signal and audio signal processing means for demodulating a video signal and an audio multiplex signal from the channel selecting means, and whether the demodulated audio signal is monaural, dual audio or stereo. Means for discriminating and outputting an audio signal mode discrimination signal, input switching means for switching and outputting the video signal and audio signal, and the video signal and audio signal of an external video or other input source such as BS, and the input A control means for controlling the switching means is provided, and the input switching means is switched to another input source side via the control means by the discrimination signal only while the audio mode discrimination signal is stereo. A television receiver characterized in that