KR20000034306A - Device for selecting an external input of television - Google Patents

Abstract

PURPOSE: A device for selecting an external input of television is provided so that an external signal can input to the television by selecting an external S-VHS and a video A/V terminals mechanically without using a switching IC. CONSTITUTION: A chroma IC(8) processes video and audio signals inputted through input terminals(R,L,V)(13). An audio amplifier(9) amplifies the audio signals outputted from the chroma IC(8) and outputs the signals through a speaker(10). A video amplifier(11) amplifies the video signals outputted from the chroma IC(8) and outputs the signals to a CRT(12). The R,L,V terminals(13) receive common VCR signals. S-terminal including Y,C separations receive S-VHS signals. If S-VHS signals are inputted, the video signals are outputted through the Y,C separation of the S terminal. On common video mode, a connection point of the S terminal is changed and video signals are outputted through the V input terminal(13).

Description

TV's external input selector

The present invention relates to a television that receives external input signals such as S-VHS and general video signals and outputs them as video signals. More specifically, the present invention relates to receiving an external S-VHS signal without using a conventional switching IC. An external input selection device of a television configured to input an external signal by mechanically selecting an S terminal and a general video A / V terminal.

General televisions currently on the market are configured to perform more diverse and comprehensive functions by connecting an external input such as a VCR. 1 is a schematic configuration diagram of a television conventionally used. Reference numeral 1 is an antenna for receiving an airwave broadcasting signal, 2 is a tuner for tuning the broadcast signal received by the antenna 1, and 3 is an intermediate frequency signal (IF signal output from the tuner 2). IF amplification part to amplify

In addition, reference numeral 4 is a P / S separator consisting of a surface acoustic wave filter (SAW FILTER) for separating the IF signal output from the IF amplifier (3) into an image intermediate frequency (PIF) and a voice intermediate frequency (SIF), 6 is an image signal detector for detecting an image signal from an image intermediate frequency output from the P / S separation unit 4. 5 is a voice signal detection unit for detecting a voice signal from the voice intermediate frequency output from the P / S separation unit 4.

The signals output from the audio signal detector 5 and the video signal detector 6 are selectively input from the switching unit 7 to the chroma IC 8. In addition, the switching unit 7 inputs an external input, that is, a video signal input from the VCR 18 to the chroma IC 8 by a control signal from the microcomputer 15. The video signal output from the chroma IC 8 is amplified through the image amplifier 11 and then output through the CRT 12.

In the conventional television as described above, the switching unit 7 which selects the signal from the tuner 2 and the signal from the VCR 18 is expensive, and the S-VHS signal that provides higher image quality than the conventional VCR is conventional. Since there is an S terminal for inputting a Y, C separation signal having a different standard from R, L, and V, a circuit becomes complicated to receive the S-VHS signal. That is, the state of connection between the switching unit 7, the audio signal detector 5, the video signal detector 6, the connection state of the output terminal of the VCR 18, the connection state of the chroma IC 8, etc. are complicated. The circuit was constructed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to mechanically connect an S terminal receiving an external S-VHS signal and a general video A / V terminal without using an expensive switching IC. The present invention provides an external input selection device of a television which can select and input an external signal.

1 is a schematic configuration diagram of a television conventionally used;

2 is a partial block diagram of a television equipped with an external input selection device according to the present invention;

3 is a flowchart showing an operating state of an external input selection device of a television of the present invention;

4A and 4B are circuit diagrams showing a connection state between a video terminal and an S-VHS input terminal.

<Explanation of symbols on the main parts of the drawing>

1: antenna 2: tuner

3: IF amplification part 4: P / S separation part

5: audio signal detector 6: video signal detector

7: switching unit 8: chroma IC

9: voice amplifier 10: speaker

11: image amplification unit 12: CRT

13: Input terminal 14, 17: Male and female S terminal

15: Micom 16: Output terminal

20: S terminal

An external input selection device of a television of the present invention comprises a chroma IC (8) for receiving and processing video and audio signals output from a VCR through input terminals (R, L, and V), and from the chroma IC (8). An audio amplifier 9 for amplifying the output audio signal through the speaker 10 and an image amplifier 11 for amplifying the video signal output from the chroma IC 8 and outputting the amplified video signal to the CRT 12. A television comprising: an R, L, V input terminal 13 for receiving a signal of a general VCR, and an S terminal 14 including Y, C separation for receiving an S-VHS signal. In the S-VHS signal input state, the video signal is output through the Y and C separations of the S terminal 14, and in the normal video mode, the video signal is output through the V input terminal 13 by changing the output mode. The connection point of the S terminal 14 is configured to switch using a relay.

Hereinafter, an external input selection device of a television of the present invention will be described in detail with reference to the accompanying drawings.

First, the general video signal and the S-VHS signal are outlined as follows.

S-VHS is a high-definition technology that eliminates interference by using S-separated transmission system for the interference of the playback Y and C signals (frequency region 3.58MHz), which has been hindering the widening of home video. Therefore, in the S-VHS video cassette recorder, the conventional general video signal is output and the S-VHS signal output is possible, which is separated according to the signal stored in the video tape.

The general video signal is output through the R and L channels and the video signal is output through the V channel. On the other hand, the S-VHS is input to the television after being output through the luminance signal Y and the color signal C terminals of the S terminal. Normally used S-VHS decks, two luminance signal circuits, VHS and S-VHS, are used, and color signal processing systems are commonly used.

2, the V terminal of the input terminal 13 is connected to the terminal V1 of the S terminal 20, and the terminal V2 is connected to the input side of the chroma IC 8. Therefore, when the terminal V1 and the terminal V2 are connected, the general video signal is input as in the conventional art. The input video signal is processed by the chroma IC 8 and then amplified while passing through the image amplifier 11 and finally output through the CRT 12. At this time, the input terminal of the Y, C signal of the S terminal 20 is the same as the conventional one.

On the other hand, the voice signal is input through the input terminals (R, L) as in the prior art, amplified by a signal of sufficient magnitude in the voice amplifier 9 and input to the speaker 10. The connection state of the Y and C input terminals for inputting the S-VHS signal to the chroma IC 8 is the same as the conventional one.

In the connection state as described above, the apparatus of the present invention is connected to a circuit such that the S-VHS of the external input is preferentially operated when the video is selected by the microcomputer 15. In other words, if S-VHS is selected, video terminal V is open, and if normal video is selected, S-VHS is open and signal input is properly blocked. This operation can be easily configured using a conventional three-terminal relay. Alternatively, the relay may be configured by combining two terminals and one terminal relay. The operating state of the relay is controlled by mode selection in the microcomputer 15.

4A and 4B show an example of input signal control using a relay assembly. As shown, in the initial mode, as shown in Fig. 4A, S-VHS is a reference mode, and a circuit is connected so that the S-VHS signal can be input to the chroma IC 8 of the television. You can see that it is open. This is a mode at the time of inputting a control signal to the microcomputer 15 for watching a video while watching television. On the contrary, in FIG. 4B, the general video signal is input and the S-VHS signal terminals Y and C are blocked.

The operational effects of the external input selection device of the television of the present invention having the above configuration are as follows.

When a command is input by the user, the microcomputer 15 recognizes this signal and outputs a control signal to perform a control operation accordingly. If the television broadcasting mode is selected, the microcomputer 15 outputs the tuning signal to the tuner 2, selects a specific broadcasting station, and then outputs the video and audio signals through the CRT 12 and the speaker 10, respectively.

At this time, when the video input mode is selected, the microcomputer 15 outputs a control signal to switch to the video mode, and the initial state controls the connection state at the S terminal 20 so that the S-VHS signal output operates first. At this time, the video output terminal V of the input terminal 13 is opened between the terminals V1 and V2 so that the video output signal is blocked from being input to the chroma IC 8, and the S terminal 20 The S-VHS signal is input to the chroma IC 8 via the Y and C terminals (see Fig. 4A).

In this initial state, when the S-VHS signal is input from the VCR, the microcomputer 15 controls the signal to be processed through the chroma IC 8. At the same time, the audio signal output from the VCR is also input through the R and L terminals of the input terminal 13 and then amplified by the voice amplifier 9 to a sufficient extent to drive the speaker 10.

However, if the signal input in the initial mode is not S-VHS, the microcomputer 15 switches the video operation mode to the normal video mode. That is, the video output terminal V of the input terminal 13 controls the general video signal to be input to the chroma IC 8 by connecting the terminals V1 and V2. At the same time, the Y and C terminals are opened to prevent input of the Y and C signals of the S terminal 20 (see Fig. 4B).

As described above, the general video signal is input to the chroma IC 8. The input general video signal is processed by the chroma IC 8 and then amplified by the image amplifier 11 and output through the CRT 12. In addition, the audio signal output from the VCR is also input through the R and L terminals of the input terminal 13 and then output after being amplified by the voice amplifier 9 to an extent sufficient to drive the speaker 10.

According to the embodiment of the present invention described above, the external signal can be input by mechanically selecting the S terminal receiving the external S-VHS signal and the general video A / V terminal without using a conventional switching IC. There is an advantage to that.

While the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited thereto, and the present invention may be variously modified and changed without departing from the spirit or the field of the present invention. It will be readily apparent to those of ordinary skill in the art.

Claims (1)

Chroma IC (8) for receiving and processing the video and audio signals output from the VCR through the input terminals (R, L, V), and amplified audio signals output from the chroma IC (8) to the speaker (10) In the television comprising a voice amplifier 9 for outputting through the video amplifier 11 for amplifying and outputting the video signal output from the chroma IC (8) to the CRT (12), R, L, V input terminal 13 for receiving the signal of the general VCR, S terminal 14 including the Y, C separation for receiving the S-VHS signal, In the S-VHS signal input state, the video signal is output through the Y and C separations of the S terminal 14, and in the normal video mode, the video signal is output through the V input terminal 13 by changing the output mode. An external input selection apparatus for a television, comprising a relay for switching the connection point of the terminal (14).