Victor Company of Japan, Limited

Sanyo Electric Co., Ltd.

Shigeru Sawada

Yutaka Shimizu

Hideaki Sasaki

Yoichi Utsumi

Teruo Hotta

An input video signal is written into alternate field memories M1 and M2, according to a timing clock from an input video clock generator. A display video signal is alternately read from those field memories, according to a timing clock from a display video clock generator. In switching a read memory, an address observation circuit judges whether or not a read/write address passes by a write/read address, referring to the condition of reading and writing operations. In this event, the circuit makes a judgement, based on the lag between a vertical synchronizing signals of an input video signal and of a display video signal, and a change of the lag with time. If it is judged that one address will pass by the other, the same read/write memory is again accessed for reading/writing. With this arrangement, there is provided a circuit having a relatively simple structure for preventing a match of read and write addresses.

Video signal processing device for writing and reading a video signal

A television receiver comprises a video signal processing circuit including a video signal demodulating circuit for generating three primary color signals from an input composite video signal, a delay circuit coupled in series to the video signal demodulating circuit within the video signal processing circuit, a parallel circuit system having virtually no delay time and coupled in parallel to the video signal processing circuit, and a picture tube applied with signals passed through a signal system of the video signal processing circuit and the parallel circuit system. The delay circuit has a delay time .tau..sub.b described by a relation .tau..sub.b .apprxeq.N.tau..sub.H -.tau..sub.a, where N is a natural number including one, .tau..sub.H represents a horizontal scanning period and .tau..sub.a represents a delay time of the signal system of the video signal processing circuit.

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Kitasouma-gun, Japan

Shigeru Sawada