KR19980058770A - High frequency input and output automatic switching method and device - Google Patents

Abstract

The present invention relates to a high frequency input and output automatic switching method and apparatus for automatically switching when an RF cable between a video cassette recorder and a television is incorrectly connected. The present invention relates to an antenna terminal and a video of a television. A plurality of RF terminal switching methods of a cassette recorder, comprising: a first RF (RF) terminal switching step of switching to one RF (RF) terminal of a television antenna terminal and a plurality of RF terminals; A channel tuning signal providing a channel tuning signal for tuning the corresponding channel of the broadcast signal received through the antenna; An AFT voltage detecting step of detecting an AFT voltage of a broadcast signal corresponding to the channel tuning signal when synchronization is detected in a broadcast signal of a channel corresponding to the channel tuning signal; A first RF terminal fixing step of switching to a first RF terminal when the AFT voltage of the broadcast signal corresponding to the channel selection signal is detected in the AFT voltage detection step; If the AFT voltage of the broadcast signal corresponding to the channel selection signal is not detected in the AFT voltage detection step, the second RF switch is switched to the other RF terminal of the plurality of RF terminals. (RF) terminal switching step; An iteration step of repeatedly performing the channel tuning signal providing step and the AFT voltage detection step; And a second RF terminal fixing step of switching to a second RF terminal when the AFT voltage of the broadcast signal corresponding to the channel selection signal is detected in the AFT voltage detection step. .

Description

High frequency input and output automatic switching method and device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio frequency (RF) input / output system of a video cassette recorder, and in particular, automatically switches an RF cable between a video cassette recorder and a television. It relates to a high frequency input and output automatic switching method and apparatus.

In general, an RF cable is connected between the video cassette recorder and the television.

That is, the video cassette recorder is equipped with an RF input terminal and an RF output terminal, and the television is equipped with an antenna input terminal, thereby connecting the television antenna input terminal and the RF output terminal of the video cassette recorder. do.

However, when the television antenna input terminal and the RF input terminal of the video cassette recorder are connected due to user's carelessness, a screen may not appear.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and an object of the present invention is to provide an RF (RF) terminal when an antenna input terminal of a television and an RF output terminal of a video cassette recorder are not connected when an RF cable is connected. The present invention provides a high frequency input / output automatic switching method and apparatus for accurately connecting RF input / output terminals by automatically switching to an output terminal.

A feature of the present invention for achieving the above object is an automatic switching device of the RF (RF) cable terminal of a television and video cassette recorder, the apparatus comprising: a tuner for tuning a broadcast signal of a corresponding channel from a broadcast signal received through an antenna; An IF signal processor which demodulates a broadcast signal provided from the tuner, provides an AFT voltage according to a video waveform change of the demodulated broadcast signal, and separates and provides a video signal and an audio signal; A video signal processor which processes a video signal provided by the IF signal processor and detects and provides a synchronization from the processed video signal; An audio signal processor for processing an audio signal provided from the IF signal processor and outputting the audio signal to a speaker; A modulator for modulating and outputting a video signal and an audio signal provided from the video signal processor and the audio signal processor; A channel input control signal is provided to the tuner, and the A / F switching signal according to the comparison result is compared by comparing the AFT voltage provided by the IF signal processor with the number of synchronizations provided by the video signal processor. A microcomputer providing a character control signal for displaying the RF input / output result on the screen; A switching unit which is switched according to the RF input and output switching signal provided by the microcomputer to automatically switch between the antenna input terminal of the television and the RF cable terminal of the video cassette recorder to output the modulated audio signal and the video signal of the modulator. ; It includes an OSD (OSD) unit for displaying the OSD characters according to the text control signal provided by the microcomputer.

The present invention for achieving the above object is a method for switching between a plurality of RF terminals of an antenna terminal of a television and a video cassette recorder, the method comprising switching to one RF (RF) terminal of the television antenna terminal and the plurality of RF terminals. 1 RF terminal switching step; A channel tuning signal providing a channel tuning signal for tuning the corresponding channel of the broadcast signal received through the antenna; An AFT voltage detecting step of detecting an AFT voltage of a broadcast signal corresponding to the channel tuning signal when synchronization is detected in a broadcast signal of a channel corresponding to the channel tuning signal; A first RF terminal fixing step of switching to the first RF terminal when the AFT voltage of the broadcast signal corresponding to the channel selection signal is detected in the AFT voltage detection step. ; If the AFT voltage of the broadcast signal corresponding to the channel selection signal is not detected in the AFT voltage detecting step, the switching to the other one of the plurality of RF terminals is performed. A second RF (RF) terminal switching step; An iteration step of repeatedly performing the channel tuning signal providing step and the AFT voltage detection step; A second RF terminal fixing step of switching to the second RF terminal when the AFT voltage of the broadcast signal corresponding to the channel selection signal is detected in the AFT voltage detection step. It includes.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

1 is a block diagram showing the configuration of a high frequency input and output automatic switching device according to a preferred embodiment of the present invention

2 is a flow chart for performing a high frequency input and output automatic switching method according to the present invention

<Description of the code | symbol about the principal part of drawing>

10: key input unit 20: micom

30: switching unit 40: tuner

50: IF signal processor 60: video signal processor

70: audio signal processor 80: modulator

90: OSD unit 100: monitor

Hereinafter, with reference to the accompanying drawings will be described in detail the operation of the preferred embodiment according to the present invention.

1 is a block diagram showing a configuration of an RF input / output automatic switching device according to the present invention, which corresponds to a key input unit 10 for providing a key signal pressed by a user and a key signal provided from the key input unit 10. The microcomputer 20 for controlling the operation of the video cassette recorder, the switching unit 30 connecting the input terminal of the antenna of the television and the RF terminal of the video cassette recorder under the control of the microcomputer 20, IF (intemediate frequency) signal processor 50 for demodulating and outputting the broadcast signal of the channel tuned by the tuner 40, the tuner 40 for tuning the channel corresponding to the provided channel tuning signal The video signal processor 60 for processing the video signal of the demodulated broadcast signal output from the (IF) signal processor 50 and the audio of the demodulated broadcast signal output from the IF signal processor 50 are output. The audio signal processor 70, the video signal processor 60, and the audio signal processor 70, which modulate and output the signal, output the signal to the monitor 100 that modulates and outputs the signal. On-screen display (OSD) unit 90 for displaying a character according to the character control signal of 20).

The detailed description of the operation of the high frequency input and output automatic switching device according to the present invention configured as described above is as follows.

The key input unit 10 is composed of key metrics and provides a predetermined key signal pressed by a user to the microcomputer 20. The key input unit 10 is provided with a plurality of keys such as a channel tuning key and is usually provided on an infrared carrier. The signal is detected and provided to the microcomputer 20.

At this time, the microcomputer 20 outputs the channel tuning signal corresponding to the channel tuning key signal provided from the key input unit 10 to the tuner 40, and the tuner 40 receives the microcomputer 20 from the broadcast signal received through the antenna. Receives a broadcast signal of a channel corresponding to the channel selection signal provided by the), and outputs the received broadcast signal to the IF signal processor (50).

That is, the IF signal processor 50 demodulates the broadcast signal output from the tuner 40, separates the demodulated broadcast signal into a video signal and an audio signal, and then the video signal processor 60 and the audio signal processor ( 70) and supplies an AFT voltage according to the waveform of the video signal of the broadcast signal to the microcomputer 20.

At this time, the video signal processing unit 60 processes the video signal output from the IF signal processing unit 50 and outputs it to the modulation unit 80, detects the synchronization, and provides it to the microcomputer 20, The audio signal processor 70 processes the audio signal output from the IF signal processor 50 and outputs the audio signal to the modulator 80.

Therefore, the modulator 80 modulates the signals output from the video signal processor 60 and the audio signal processor 70 and outputs the modulated signals to the switching unit 30.

In this case, as described above, if the synchronization is detected by the video signal processing unit 60 and the AFT voltage is detected by the IF signal processing unit 50, the RF currently switched is RF. For example, as shown in FIG. 1, the first switching unit 31 is connected with a and c, and the second switching unit 32 is fixed with d and f connected with the switching unit 30. ), And if the synchronization and the AFT voltage are not detected, the other switching (RF) terminal, that is, the first switching unit 31, is connected to b and c at the currently switched RF terminal. The second switching unit 32 controls the switching unit 30 to switch to a state in which e and f are connected.

Accordingly, the switching unit 30 switches to a switching mode under the control of the microcomputer 20 and outputs a broadcast signal received through the antenna to the RF output terminal.

On the other hand, as described above, the microcomputer 20 switches to another RF terminal, and if the AFT voltage is not detected, an OSD character control signal indicating that there is no current input signal is displayed. Provided to the unit 90.

Accordingly, the OS unit 90 outputs the character according to the OSD character control signal of the microcomputer 20 to the monitor 100.

FIG. 2 is a flow chart for performing a high frequency input / output automatic switching method according to the present invention, which will be described in detail with reference to the block diagram shown in FIG. 1.

The microcomputer 20 connects the switching terminal 30 of the first switching unit 31 to a and c and the switching terminal 30 of the second switching unit 32 to d and f in step 200. In operation 201, the control signal for tuning the channel corresponding to the channel selection signal provided from the key input unit 10 is output.

Accordingly, the tuner 40 tunes a channel corresponding to the channel tuning control signal output from the microcomputer 20.

On the other hand, the microcomputer 20 proceeds to step 202 to determine whether the synchronization is detected from the video signal processor 60, and if the synchronization is detected, the microcomputer 20 proceeds to step 203 and the IF signal processor 50 performs the AF. It is determined whether an AFT voltage is detected.

As a result of the determination, if the AFT voltage is detected by the IF signal processing unit 50, the flow proceeds to step 204 to fix the switching terminal switched in step 200, and the IF signal processing unit 50. ), If no AFT voltage is detected, the process proceeds to step 205 to connect the switching terminals of the first switching unit 31 to b and c, and the switching terminals of the second switching unit 32 to e and f. The switching unit 30 is controlled to be connected to the control unit, and the flow proceeds to step 206 to output a control signal for selecting a channel corresponding to the channel selection signal provided from the key input unit 10.

In this case, if the synchronization is detected in the broadcast signal of the channel corresponding to the channel tuning signal output in step 206, the microcomputer 20 proceeds to step 208 to determine whether the AFT voltage is detected. do.

That is, if the AFT voltage is detected by the IF signal processor 50 in step 208, the microcomputer 20 proceeds to step 209 to fix the switching terminal switched in step 205.

In the meantime, if the AFT voltage is not detected by the IF signal processor 50 in step 208, the microcomputer 20 proceeds to step 210 to display a message indicating that there is no input signal. (OSD) character control signal is provided, and the OSD unit 90 outputs a character according to the OSD character control signal of the microcomputer 20 to the monitor.

As described above, the RF input / output automatic switching device and method according to the present invention automatically switch to the RF output terminal when the antenna input terminal and the RF input / output terminal of the television are incorrectly connected, thereby the antenna of the television. The effect is that the input terminal and RF output terminal can be connected correctly.

While the invention has been shown and described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various modifications, changes and omissions can be made without departing from the spirit and scope of the invention.

Claims (3)

As a method of switching between a plurality of RF terminals of an antenna terminal of a television and a video cassette recorder, A first RF terminal switching step of switching to an RF terminal of the television antenna terminal and the plurality of RF terminals; A channel tuning signal providing a channel tuning signal for tuning the corresponding channel of the broadcast signal received through the antenna; An AFT voltage detecting step of detecting an AFT voltage of a broadcast signal corresponding to the channel tuning signal when synchronization is detected in a broadcast signal of a channel corresponding to the channel tuning signal; A first RF terminal fixing step of switching to the first RF terminal when the AFT voltage of the broadcast signal corresponding to the channel selection signal is detected in the AFT voltage detection step. ; If the AFT voltage of the broadcast signal corresponding to the channel selection signal is not detected in the AFT voltage detecting step, the switching to the other one of the plurality of RF terminals is performed. A second RF (RF) terminal switching step; An iteration step of repeatedly performing the channel tuning signal providing step and the AFT voltage detection step; A second RF terminal fixing step of switching to the second RF terminal when the AFT voltage of the broadcast signal corresponding to the channel selection signal is detected in the AFT voltage detection step. High frequency input and output automatic switching method comprising a. The method of claim 1, wherein if the AFT voltage is not detected in the second RF terminal fixing step, a message indicating that there is no input signal is displayed. An RF (terminal) cable terminal automatic switching device for television and video cassette recorders, A tuner which tunes and provides a broadcast signal of a channel from a broadcast signal received through an antenna; An IF signal processor which demodulates a broadcast signal provided from the tuner, provides an AFT voltage according to a video waveform change of the demodulated broadcast signal, and separates and provides a video signal and an audio signal; A video signal processor which processes a video signal provided by the IF signal processor and detects and provides a synchronization from the processed video signal; An audio signal processor for processing an audio signal provided from the IF signal processor and outputting the audio signal to a speaker; A modulator for modulating and outputting a video signal and an audio signal provided from the video signal processor and the audio signal processor; A channel input control signal is provided to the tuner, and the A / F switching signal according to the comparison result is compared by comparing the AFT voltage provided by the IF signal processor with the number of synchronizations provided by the video signal processor. A microcomputer providing a character control signal for displaying the RF input / output result on the screen; A switching unit which is switched according to the RF input and output switching signal provided by the microcomputer to automatically switch between the antenna input terminal of the television and the RF cable terminal of the video cassette recorder to output the modulated audio signal and the video signal of the modulator. ; High frequency input and output automatic switching method including an OSD (OSD) unit for displaying the OSD character according to the character control signal provided by the microcomputer.