JPH05168028A - Television receiver - Google Patents

Abstract

PURPOSE:To simplify a signal switching circuit and to easily realize a multi- system television by providing a signal integrated circuit to switch luminance and chrominance signals by the same signal line control as an input video signal. CONSTITUTION:Composite video signals from an antenna 1 and an external terminal 3 are selected by a signal switching integrated circuit 5 and impressed to a deflecting circuit 8 and Y/C signal separating circuits 6 and 7. The separated luminance signal (Y signal) and chrominance signal (C signal) are respectively processed by a luminance signal processing circuit 9 and a chrominance signal demodulation circuit 10 and impressed to a CRT afterwards. Then, the chrominance signal demodulation circuit 10 switches the signal switching integrated circuit 5 through a control circuit 4 so that the signals from the Y/C separating circuits 6 and 7 can be impressed to the luminance signal processing circuit 9 and the chrominance signal demodulation circuit 10 corresponding to the signal system of a desired signal to be received. Therefore, the Y/C separated signals can be switched corresponding to the chrominance signal system without using any complicated switching circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is suitable for application to, for example, a television receiver which receives a plurality of color signal systems.

[0002]

2. Description of the Related Art Conventionally, in a television receiver (hereinafter, abbreviated as a multi-channel television) which receives a plurality of different color signal systems, an input composite video signal (hereinafter abbreviated as a video signal) is selected and the signal is A plurality of luminance and color signal separation circuits (hereinafter abbreviated as Y / C separation circuits) provided according to the color signal system are added to separate the luminance signal and the color signal. The chrominance signal is transmitted to the separated luminance signal image processing circuit, demodulated and transmitted to the color demodulation circuit, and finally reproduced as an image on the CRT.

[0003]

In general, however, in a multi-system television, since a luminance signal and a color signal are correctly reproduced according to the signal system, a Y / C separation circuit in which the video signal corresponds to the color signal system. Circuit selection is required to be added to. That is, as shown in FIG. 3, after the input signal is selected, the switching circuit to the Y / C separation circuit corresponding to the signal system switches the signal. Further, this signal switching control is performed via a dedicated signal line from the control circuit. Therefore, the conventional multi-system television has a problem that the signal switching circuit becomes complicated. The present invention has been made in consideration of the above points, and an object of the present invention is to provide a television receiver having a simplified signal switching circuit.

[0004]

In order to solve such a problem, in the present invention, a selection circuit for a composite video signal and Y / Y for separating the selected signal into a luminance signal and a chrominance signal are provided.
An output circuit to the C separation circuit and a signal switching means from a plurality of Y / C separation circuits are provided, and the control of the composite video signal selection circuit and the control of the input signal switching from the Y / C separation circuit are the same control signal. Provide an integrated circuit that is performed by wires.

[0005]

The switching circuit is simplified by selecting the composite video signal and switching the luminance signal and the chrominance signal from the Y / C separation circuit by one integrated circuit and by using the same control signal line. It

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a multi system television will be described in detail below with reference to the drawings. In FIG. 1, the high frequency signal obtained from the antenna 1 is demodulated by the tuner 2 into a composite video signal. A composite video signal from an external video device is input to the external input terminal 3. For these signals, signals to be displayed on the screen are selected by the signal switching integrated circuit 5 and added to the deflection circuit 8, the Y / C signal separation circuit 6 and the separation circuit 7. The video signal applied to the deflection circuit controls the scanning line. Y / C signal separation circuit 6 and Y
The / C separation circuit 7 has different circuit characteristics corresponding to the color system of the video signal. The separated luminance signal (hereinafter abbreviated as Y signal) and color signal (hereinafter abbreviated as C signal) are processed by the luminance signal processing circuit 9 and the color signal demodulation circuit 10, respectively, and then added to the CRT. The color signal demodulation circuit discriminates the color signal system as well as the color signal demodulation, and the signal from the Y / C separation circuit corresponding to the color signal system of the signal to be received is the luminance processing circuit so that the correct color demodulation is performed. , The signal switching integrated circuit 5 is switched through the control circuit 4 so as to be added to the color signal modulation circuit. FIG. 2 shows the details of the signal switching integrated circuit 5. The composite video signal is applied to the input terminal 13 and switched by the internal switch 14, and the amplifier 1
After being amplified at 5, it is output from the video output terminal 16. Y
The luminance signal from the / C separation circuit is input from terminal 17,
After being switched by the internal switch 18, it is output from the output terminal 19. The color signal also passes through a circuit having a similar configuration.

Switching of these internal switches 14, 18 and 21 is performed by a control signal from a control section through a control signal line 22.

According to the above configuration, it is possible to switch the Y / C separation signal according to the color signal system without using a new Y / C separation signal switching circuit.

[0009]

As described above, according to the present invention, the input video signal selection circuit, the output circuit to the Y / C separation circuit, and the Y / C
The signal switching circuit can be simplified by using a signal integrated circuit that has a switching circuit for the luminance and chrominance signals from the separation circuit and can be switched by the same signal line control as that of the input video signal. Realization becomes easy.

[Brief description of drawings]

FIG. 1 is a block diagram of a television receiver according to an embodiment of the present invention.

FIG. 2 is a detailed block diagram of a signal switching integrated circuit of the present invention.

FIG. 3 is a block diagram of a conventional television receiver.

[Explanation of symbols]

 5 signal changeover integrated circuit 6 Y / C separation circuit 7 Y / C separation circuit 14 video input changeover switch 16 video output terminal 17 luminance signal changeover switch 21 color signal changeover switch

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hiroaki Hirahara 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Akio Nakatani, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Yoshinao Watanabe 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A selection circuit for inputting a plurality of composite video signals,
A television characterized by comprising an output circuit to a separation circuit for separating the selected signal into a luminance signal and a chrominance signal, and an integrated circuit having means for switching the inputs from the plurality of luminance and chrominance signal separation circuits. John receiver 2. The television receiver according to claim 1, wherein the switching means for the plurality of luminance and color signal input circuits is means for using the same signal line as the switching control signal for the composite video signal.