JPH088668B2 - Television signal receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a television receiver or a television receiver which is adapted to automatically switch to another channel during a commercial broadcast.
The present invention relates to a television signal receiving device such as a VTR.

[Conventional technology]

In the conventional television receiver, when the broadcast content becomes a commercial broadcast, the user switches to another channel,
Even if the timing for ending the commercial was estimated, the switching operation was performed to return to the original channel.

[Problems to be Solved by the Invention]

For this reason, when the program of the channel being watched becomes commercial, the user has to switch the receiving channel, and when returning to the original channel, it is still a commercial broadcast or there is a delay in returning timing. There is a problem that it is difficult to switch channels properly, such as the program has already started.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a television receiver capable of automatically switching to another channel only while a commercial program is being broadcast. .

[Means for solving the problem]

A television receiver according to the present invention has a tuner for demodulating a television signal of a plurality of channels into a video signal and an audio signal, a video demodulation circuit, and an audio multiplex demodulation circuit for demodulating a domestic audio multiplex signal, and receiving Detecting whether the audio broadcast is in stereo mode or bilingual mode from the identification signal of the domestic audio multiplex signal of, and switch to the state of receiving another channel while the identification signal changes. It is the one.

[Action]

According to the present invention, when the program of the channel the user is watching becomes a commercial broadcast, it is automatically switched to a state of receiving the broadcast of another channel, and the commercial broadcast of the program originally watched ends. Then the original channel is automatically switched.

〔Example〕

FIG. 1 is a block circuit diagram of an embodiment of the present invention. In this embodiment, an explanation will be given of what is constructed so as to be able to receive two television broadcasts.

In the figure, (1) is an antenna, (2a) is a first tuner, (2b) is a second tuner, (3a) is a first video signal demodulation circuit, (3b) is a second video signal demodulation circuit, (Four
a) is a first audio signal demodulation circuit, (4b) is a second audio signal demodulation circuit, (5a) is a first audio multiplexed signal demodulation circuit, (5b) is a second audio multiplexed signal demodulation circuit,
(6) is a video signal selector switch, (7) is an audio signal selector switch, (10) and (11) are transistors,
(12) and (13) are light emitting diodes, and (10) and (12) constitute a stereo broadcast display means, and (11) and (13) constitute a bilingual broadcast display means. (14) is a microcomputer, (15) is its key matrix part, (16a)
~ (16n) is the switch, (22) is the remote control light receiving section, and (23) is the amplifier.

FIG. 2 is a flowchart of the control operation in the microcomputer of this embodiment, and FIG. 3 is a diagram showing the frequency band of the domestic audio multiplex broadcast signal.

 Next, the operation of this embodiment will be described.

This invention was made by paying attention to the fact that commercial broadcasting is not bilingual broadcasting in the case of bilingual broadcasting, and commercial broadcasting is stereo broadcasting in the case of monaural broadcasting. If it does not meet the above conditions, it will be excluded from the application.

In this embodiment, there are first and second reception channels, and the first channel and the second channel simultaneously receive broadcasts of different channels. The television signal received by the antenna (1) is
a), (2b), video signal demodulation circuits (3a), (3b), audio signal demodulation circuits (4a), (4b) and audio multiplex signal demodulation circuits (5a), (5b) respectively in the first channel And a second channel video signal and audio signal are demodulated. In the case of a television receiver, the video signal is subjected to luminance signal processing and chroma signal processing so that an image is displayed on the cathode ray tube and an audio signal is amplified. In the case of VTR, the video signal is divided into a luminance signal and a chroma signal, which are subjected to signal processing and recorded on a magnetic tape, and the audio signal is also subjected to signal processing. Recorded on magnetic tape.

The audio signal demodulated by the voice demodulation circuit (4a) is input to the voice demodulation circuit (5a) as a signal having a frequency band as shown in FIG. Of this demodulated audio signal, the audio signal of the sub-channel is FM-modulated with double the horizontal synchronizing frequency of about 31.5KHz as a carrier,
In the case of two-language broadcasting, the main channel is Japanese and the sub-channel is a foreign language, and in the case of stereo broadcasting, the main channel is the left and right sum signal and the sub-channel is the difference signal. As an identification signal of these two kinds of audio signals, a carrier of 982.5Hz in the case of stereo broadcasting and a signal of 922.5Hz in the case of two-language broadcasting is FM-modulated at 55.125KHz which is 3.5 times the frequency of the horizontal synchronizing signal. . Audio multiple signal demodulation circuit (5a)
Detects the frequency of this identification signal to determine whether it is a stereo broadcast or a bilingual broadcast, and an internal matrix circuit outputs the left and right channel audio signals in the case of a stereo broadcast, or a bilingual broadcast. In the case of, the main and sub channel audio signals are output respectively.

In this embodiment, the microcomputer (14) has
The audio multiplex identification signals (8) and (9) of the first channel are input, and in the case of stereo broadcasting, the identification signal (hereinafter referred to as "ST signal") (8) becomes "H" level,
The transistor (10) turns “ON” and the LED (12) lights up, indicating that the broadcast is stereo. In the case of bilingual broadcasting, an identification signal (hereinafter referred to as "B1 signal")
(9) becomes "H" level, the transistor (11) becomes "ON" and the LED (13) lights up to indicate that it is a bilingual broadcast.

This ST signal (8) and B1 signal (9) are
a), (2b) and the microcomputer (14) controlling the channel selection, the microcomputer (14) operates the switches (16a) ... (16n) of the key matrix section (15) by the user. Press to select channel (20),
(21) is sent to the tuners (2a) and (2b) to control the up / down of the receiving channel. Although detailed description is omitted here, the microcomputer (14) is also configured to switch the voice and to raise / lower the output level of the audio signal.

The microcomputer (14) switches the switches (6) and (7) when the ST signal (8) or B1 signal (9) of the receiving first channel changes, and outputs the video signal and the audio signal of the second channel. Then, when the ST signal (8) or the B1 signal (9) of the first channel is duplicated, the channel is switched to the first channel. Therefore, only during the period when the broadcast of the first channel is the commercial broadcast,
The broadcast program of the channel will be received.

In this embodiment, in order for the user to switch to the automatic channel switching mode (mode for switching to the second channel side during commercial), it is configured to be executed by pressing a switch (16d) not shown. There is.

In addition, the second receiving channel is set in advance by the user by a switch (16e) not shown, or the second receiving channel is automatically switched to a receivable channel by the microcomputer (14). The configuration may be such that, when the channel is switched to the second channel, if the user presses a switch (16f) (not shown) while switching to the second channel automatically, Either of them may be set as the reception channel.

Note that such switching of the operation modes may be performed by the remote control by the remote control light receiving section (22) and the amplifier (23), in addition to the switches (16a) to (16n).

Next, the operation of the microcomputer (14) will be described with reference to the flowchart of FIG.

First, a case where the first channel being received is monaural broadcasting will be described.

When the automatic channel switching mode is set in S1, it is determined whether or not the B1 signal (9) is present in S2.
If there is no ST signal (8), the process returns to S2, and if there is, the process advances to S4 to switch the switches (6) and (7) to the second channel side. That is, in the case of monaural broadcasting, commercials are stereo broadcasting. Next, in S5, when the ST signal (8) is input, the process proceeds to S6, and switches (6),
Switch (7) to channel 1 and return to S2.

On the other hand, when the B1 signal (9) is detected in S2, the process proceeds to S7 and B1
When the signal disappears, the process proceeds to S8 to switch the switches (6) and (7) to the second channel, and when the B1 signal (9) is input at S9, the process proceeds to S10 to set the switches (6) and (7) to the first channel. Switch to channel and return to S7.

By the above operation, the channel selection operation is performed in which the commercial broadcasting is automatically switched to the second channel and the commercial broadcasting is automatically switched to the original first channel when the commercial broadcasting ends.

〔The invention's effect〕

As described above, according to the present invention, when the main broadcast is a monaural broadcast, the commercial broadcast is a stereo broadcast, and when the main broadcast is a bilingual broadcast, the commercial broadcast is broadcast in a mode other than the bilingual broadcast. To detect that
Since the broadcast content of the second reception channel is switched during this detection period, when the program currently being watched becomes a commercial broadcast, it is automatically switched to another channel, and with the end of the commercial broadcast. There is an effect that a television receiver that automatically switches back to the channel it was originally watching can be obtained.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of an embodiment of the present invention, FIG. 2 is a flow chart of control operation in the microcomputer of this embodiment, and FIG. 3 is a diagram showing a frequency band of domestic audio multiplex broadcasting. (2a), (2b) ... Tuner, (3a), (3b) ... Video signal demodulation circuit, (4a), (4b) ... Audio signal demodulation circuit, (5a), (5b) ... Voice multiplexing Signal demodulation circuit,
(6) ... video signal changeover switch, (7) ... audio signal changeover switch, (14) ... microcomputer.

Claims (1)

[Claims] 1. A signal processing circuit for receiving a television broadcast of at least two channels and demodulating a video signal and a multiplexed audio signal, and whether the demodulated multiplexed audio signal is a stereo signal or a bilingual broadcasting signal. A means for discriminating based on the identification signal, and when the audio mode being received is monaural broadcasting, outputs the video signal and audio signal of another receiving channel during the period when the identification signal of the stereo broadcasting is detected and receiving. In the case where the audio mode is a bilingual broadcast, the television signal reception means is provided with means for outputting video signals and audio signals of other receiving channels during a period in which the identification signal of the bilingual broadcast is not detected. apparatus.