Color-difference signal conversion circuit

Abstract

A television receiver comprises an input circuit (1) for Y, PB, and PR signals of an external component video input signal, a matrix circuit (5) having a function of converting luminance signal Y and transmitted chrominance signals PB and PR into primary color signals R, G, and B, and a function of converting luminance signal Y and color-difference signals B-Y and R-Y into primary color signals R, G, and B, and a color-difference conversion circuit (8). When Y, PB, and PR signals of an external component video input signal based on various television systems are fed to the color-difference signal conversion circuit (8), the video signal discriminating circuit (7) determines the video signal format based on data characterizing a video signal such as the horizontal sync frequency and the like of the input signal, and automatically converts the output of the color-difference signal conversion circuit (8) to either Y, PB, and PR signals or to Y, B-Y, and R-Y signals, and supplies the converted signals to the matrix circuit (5). The matrix circuit (5) generates primary colors faithful to the component video input signals of various incoming television systems.

Description

technical field [0001] The present invention relates to a color difference signal conversion circuit for a television receiver capable of reproducing component video input signals according to various television standards in addition to existing television standards, and in particular to a color difference The signal conversion circuit can automatically convert the above-mentioned component video signal into a color-difference signal faithful to the chromaticity standard of the input signal according to various TV systems. In particular it relates to a technique that exploits the functional relationship between the broadcast chrominance signals PB and PR and the color difference signals B-Y and R-Y of an external component video input signal. Background technique [0002] Fig. 4 shows an example of the schematic configuration of a conventional television receiver. In FIG. 4, reference numeral 1 is an input circuit for a luminance signal Y of an external component video inpu...

AI Technical Summary

Problems solved by technology

The SDTV signals transmitted in Y, PB and PR signal formats are passed into the matrix circuit 5 through the first selector 3, and are converted into primary color signals R, G and B by the HDTV matrix conversion function instead of the SD matrix conversion function, thus There is a problem that colors cannot be reproduced accurately

[0006] In addition, with the development of media convergence in the future, it is possible to transmit component video signals of Y, PB, and PR formats of personal computer images to television receivers through the Internet, and this arises how to identify the video signal format so as to produce sufficient color difference signal problem

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