Pioneer Electronic Corporation

Tadao Nuka

Akira Nagashima

Koji Shibata

Yasuo Kawakami

Yutaka Miyahara

An S/N ratio measuring method of a video signal which is suitable for the formation of an IC and can precisely detect a fluctuation of an S/N ratio of a video signal at high response speed while suppressing the total cost and a system based on this method. In operation, a composite video signal is received, a noise density in a predetermined period of the composite video signal is detected, and an S/N ratio of a video signal included in the composite video signal is recognized basis on the detected noise density. The S/N ratio measuring system has a demodulator for demodulating the composite video signal from the reception signal and a counter for counting noises which are generated in a predetermined period of time of the composite video signal and recognizes the S/N ratio of the video signal included in the composite video signal based on a count value obtained.

Apparatus for measuring S/N ratio of composite video signal

A removable panel has a plurality of operation buttons for operating a car stereo. A cellular telephone system operated by the operation buttons is provided in the panel. A controller is provided in the panel for rendering the car stereo inoperative in response to an instruction received through the cellular telephone system.

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Kawagoe, Japan

Tadao Nuka