JPH03155286A - Television image receiver - Google Patents

Abstract

PURPOSE:To prevent displaying only noise on a screen in a channel having no television(TV) broadcasting and to prevent the generation of large noise sound from a speaker by discriminating the existence of TV broadcasting in a received channel by the existence of a synchronizing signal and, displaying a received signal image only when a TV broadcasting signal exists. CONSTITUTION:Channels selected by a tuner part 2 are successively switched by depressing a receiving channel UP or DOWN key on a remoter controller 19 or a key input part 17, the existence of a received channel TV broadcasting signal 1a is discriminated by the existence of a synchronizing signal 4a inputted to a main control part 16 or the level of an output signal from an automatic gain control part 3, and only when the signal 1a exists, the image of the received signal 1a is displayed on a CRT 12. Thereby only the screen receiving TV broadcasting can be displayed without presetting the channel number of TV broadcasting in the memory of the main control part 16. When the broadcasting is stopped, annoying noise picture is not displayed on the display screen.

Description

[Detailed Description of the Invention] [Prior Art] A channel number of a television broadcast to be received is set in advance in a memory corresponding to a channel selection key of a television receiver body or a remote controller, and a memory corresponding to the operated channel selection key is set in advance. It was used to memorize and receive TV broadcasts of certain channel numbers.

[Problem that the invention sought to solve]

When you continuously change the channel to be received using the key input section of the TV receiver or the channel UP or DOWN key on the remote control, the screen will be full of noise on channels where there is no TV broadcast, and the sound will be louder than the speakers, so be careful. It was something that I was concerned about.

Furthermore, even when the display screen of a television receiver is divided and the broadcast content of each channel received is displayed on each divided screen, the screen of the channel that is not being broadcast becomes a noise screen and is an eyesore.

[Means to solve the problem]

UP the reception channel of the remote controller or key input unit
By operating the /DOWN key, the tuner section selects channels in sequence, and determines whether there is a TV broadcast on the received channel by the presence or absence of a synchronization signal or the magnitude of the automatic gain control signal, and receives only when there is a TV broadcast signal. The image of the signal is displayed on a cathode ray tube.

In addition, the numbers of receivable channels are stored in advance in a non-volatile memory, and the channels stored in the non-volatile memory are sequentially switched to display only the video of the channel with the broadcast signal.

[Effect]

From the input television broadcast signal 1a, the main control section 16 comprising a microcomputer selects the signal of the channel designated by the channel selection signal 16a output, and the demodulated audio signal 2b is amplified by the audio amplification section 14 and output to the speaker 15. and outputs the detected video signal 2a.

A part of the video signal 2a output from the tuner section 2 is input to the automatic gain control section 3, and the automatic gain control signal (hereinafter referred to as A) is outputted from the automatic gain control section 3.
The gain of the tuner section 2 is controlled by a GC signal (referred to as a GC signal) 3a, so that the amplitude of the output video signal 2a is kept approximately constant.

The video signal 2a output from the tuner section 2 is transmitted to the video amplification section 11.
The synchronous signal 4a is amplified and supplied to the cathode ray tube 12 and also supplied to the synchronous detection section 4 to separate the synchronous signal 4a.
A high voltage and a sawtooth current for accelerating and deflecting the electron beam of the cathode ray tube 12 synchronized with a are generated and supplied to the cathode ray tube 12, thereby reproducing and displaying the image of the received broadcast signal.

The main control unit 16 reads the control signal corresponding to the operated key of the key input unit 17 or the remote controller 19 via the remote control signal receiving unit 18, outputs a control signal corresponding to the content of the control signal, and outputs a control signal corresponding to the content of the control signal. Execute control.

By operating the key input unit 17 or the reception channel UP or DOWN key of the remote controller 19, the main control unit 16
The channels selected by the tuner section 4 are sequentially switched using the tuning signal 16a outputted by the tuner section 4, and the gain of the tuner section 4 is controlled using the AGC signal 3a generated from the video signal 2a outputted from the tuner section 4. is supplied to the main control section 16.

The presence or absence of the broadcast signal of the received channel is determined based on the magnitude of the input AGC signal in the main control unit 16, and for channels without a broadcast signal, the image of the received signal is displayed on the cathode ray tube for a predetermined period of time, and then for channels with a broadcast signal, the image of the received signal is displayed on the cathode ray tube. Switch to the next channel, and repeat the above operations until the channel UP or DOWN key of the key input section 17 or remote controller 19 is no longer pressed.

FIG. 2 is a flowchart showing the control procedure in the main control unit 16 when operating the channel selection key of the remote controller 19. Even when operating the channel DOWN key, only the addition/subtraction and maximum/minimum relationships are reversed; The same is true.

The same applies when a so-called channel multi display mode is specified, in which the display screen is divided into 4 or 9 parts by operating the key input section 17 or the remote controller 19, and the video of each channel received is displayed on each divided screen. Sequentially switching the channel selection signal 16a output from the main control unit 16,
Channels without broadcast signals are skipped, and channels with broadcast signals receive the same broadcast signals for a predetermined period of time.

The video signal 2a obtained from the received broadcast signal is converted into digital data by the analog-to-digital converter 6 using the control pulse 9a output from the sub-control unit 9, which is controlled by the synchronization signal 4a detected from the video signal 2a, as a clock signal. do.

The digital data obtained by converting the video signal 2a is sampled to be thinned out according to the number of divisions of the display screen by the control pulse 9b output from the sub-control unit 9, and is stored in a memory corresponding to the position of the division screen to be displayed according to the order of reception. 7 is temporarily stored in a predetermined location.

The digital data of the video signal stored in the memory 7 is converted into an analog video signal by the digital-to-analog converter 8, and the control signal 9c generated and output by the sub-control unit 9 is converted into an analog video signal by the digital-to-analog converter 8. The signal is supplied to the video signal section 11 via the switched switch circuit 10 and displayed on the cathode ray tube 12.

On the display screen on the cathode ray tube 12, the received video of each channel is displayed as a reduced still image on each divided screen.

〔Example〕

The television broadcast signal 1a input to the antenna terminal 1 is supplied to the tuner section 2, and the tuner section 2 selects the broadcast signal of the specified channel by the channel selection signal 16a output from the main control section 16 constituted by a microcomputer. The amplified and demodulated audio signal 2b and video signal 2a are output.

The audio signal 2b output from the tuner section 2 is amplified by the audio amplification section 14, drives the speaker 15, and outputs the audio signal 2b from the tuner section 2.
Step 5 converts it to audible sound.

The video signal 2a outputted from the tuner section 2 is supplied to the video amplification section 11 via a switch circuit 1o that switches the input signal of the video amplification section 11 that amplifies the signal supplied to the cathode ray tube 12, and is also supplied to the automatic gain control section 3 and It is also supplied to the synchronization detection section 4.

The signal gain of the tuner section 2 is controlled by the AGC signal 3a generated by the video signal 2a supplied to the automatic gain control section 3, and the video signal 2 outputted from the tuner section 2.
The amplitude of a was kept constant.

A synchronization signal 4a is obtained from the video signal 2a supplied to the synchronization detection section 4.
The deflection high voltage section L3 inputs the synchronization signal 4a and outputs it to the cathode ray tube 12 in synchronization with the synchronization signal 4a.
A sawtooth current and high voltage are generated and supplied to the cathode ray tube 12 for accelerating and deflecting the electron beam.

The video signal 2a outputted from the tuner section 2 is an analog signal.
The signal is also supplied to a digital converter 6, and the video signal 2a is converted into digital data using an analog-to-digital conversion control signal 9a generated by a sub-control unit 9 controlled by the synchronization signal 4a and output.

The main control unit 16 decodes the operation command for the screen split display mode called channel multi inputted from the remote control operator 19 via the remote control signal receiving unit 18 or the key input unit 17 of the television receiver body. The digital data output from the analog-to-digital converter 6 is sampled and stored in a predetermined location in the memory 7 under the control of the memory control signal 9b output from the sub-control section 9.

An example of dividing the display screen on a cathode ray tube is shown in FIG. 3. In the figure, the numbers in the divided screen are the video signals of the received channels combined with the channel numbers and displayed.

The main control unit 16 that has decoded the operating command for the split screen display mode sequentially switches channels to be selected according to the control procedure shown in FIG. The data is converted into data and sequentially stored in predetermined locations in the memory corresponding to each of the divided display screens.

The digital data stored in the memory 7 is read out using a digital-to-analog conversion control signal 9c synchronized with the synchronization signal 4a inputted to the sub-control unit 9, and the digital-to-analog converter 8 is controlled to convert it into an analog video signal. The cathode ray tube 1 is connected to the output of the digital-to-analog converter 8 via a switch circuit 10 and a video amplifying section 11.
Supply to 2.

A still image of each channel of the television broadcast signal received is displayed on each divided screen of the cathode ray tube 12.

When the number of received broadcast channels is less than the number of divided screens of the cathode ray tube 12, only the images of the broadcasts that can be received are displayed again using the control procedure shown in FIG. It is also possible to set only the screen and make the other screens blue-colored.

The above method divides the display screen of the television and displays each video of the received television broadcast channel on each divided screen. UP or DO
Even if the received channels are sequentially switched and displayed by operating the WN key, only the broadcast screen can be displayed by skipping channels that are not broadcast.

Further, a switch circuit for switching the audio signal 2b and video signal 2a output from the tuner section 2 is provided at the output of the tuner section 2, and by controlling and switching the switch circuit by the main control section 16, the video signal output from the VTR etc. It is also possible to process the video signal in the same way as the video signal of the receiving channel and display the video on one of the split screens.

〔Effect of the invention〕

As described above, only the screen with the TV broadcast can be displayed without presetting the channel number of the TV broadcast being broadcast in the memory of the main control unit.

Furthermore, even if the receivable channel numbers of television broadcasts are preset, an annoying noise screen will not be displayed on the display screen even if the broadcasts stop late at night.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the television receiver of the present invention, FIG. 2 is a flowchart of the control procedure when channel is up, and FIG. 3 is an example of dividing the display screen. In the figure, 1 is an antenna terminal, la is a broadcast signal, 2 is a tuner section, 2a is a video signal, 2b is an audio signal, 3 is an automatic gain control section, 3a is an automatic gain control signal (AGC signal), 4 is synchronization detection 4a is a synchronization signal, 6 is an analog-to-digital converter, 7 is a memory, 8 is a digital-to-analog converter,
9 is a sub-control unit, 9a is an analog-digital conversion control signal, 9b is a memory M control signal, 9C is a digital-analog conversion control signal, 10 is a switch circuit, 11 is a video amplification unit,
12 is a cathode ray tube, 13 is a deflection high voltage section, 14 is an audio amplification section, 15 is a speaker, 16 is a main control section, 16a is a channel selection control signal, 17 is a key input section, 18 is a remote control signal receiving section, 19 is a remote control operation It is a vessel.

Claims (3)

[Claims] (1) Based on the TV broadcast signal input to the tuner section, specified by the operation command output from the remote control operator via the remote control signal receiving section or the key input section, and the channel selection signal output from the main control section that inputs the operation command. Selecting the broadcast signal of the channel, controlling the gain of the tuner section with the output signal of the automatic gain control section into which the video signal output from the tuner section is input, and keeping the amplitude of the video signal output from the tuner section constant. At the same time, the same video signal is supplied to the cathode ray tube via the synchronization detection section and the video amplification section, and the deflection high voltage section that accelerates and deflects the electron beam of the cathode ray tube is synchronized with the synchronization signal output from the synchronization detection section to reproduce the image. In the television receiver, by operating the reception channel UP or DOWN key from the remote controller or key input section,
Sequentially switching the channels selected by the tuner section,
The presence or absence of the television broadcast signal of the received channel is determined by the presence or absence of the synchronization signal input to the main control section or the magnitude of the output signal of the automatic gain control section, and the video of the received broadcast signal is determined only when there is a television broadcast signal. A television receiver that displays images on a cathode ray tube. (2) The main control unit is set to a preset mode by operating the remote controller or the key input unit, and the specified channel number is stored in advance in a non-volatile memory within the main control unit; The television receiver according to claim 1, characterized in that only channels are switched sequentially. (3) The video signal output from the tuner section is converted into digital data by the control signal of the sub-control section controlled by the synchronization signal by the operation command of the remote controller or the key input section, and a part of the digital data is sampled. In a mode in which the digital data temporarily stored in a predetermined part of the memory and read out is converted into an analog video signal, and the input of the video amplification part is switched to the same video signal, and the display screen is divided and displayed, the tuner part The television receiver according to claim 1 or claim 2, wherein the channels to be selected are sequentially switched and the received video signals of each channel are displayed on each divided display screen.