Matsushita Electric Industrial Co., Ltd.

Takuji Yoneda

Atsushi Ohara

A video signal processor reduces the deterioration of image quality due to the superposition of noise on a sync signal included in a luminance signal. A frequency discriminator outputs a first error signal if a ratio of the frequency of a frequency-modulated signal during a sync-signal interval to the frequency of a reference frequency signal is smaller than a predetermined ratio. Alternatively, the discriminator outputs a second error signal if the ratio is greater than the predetermined ratio. If the first error signal has been input to a frequency controller a preset number of times or more during an interval before the second error signal is input thereto, the controller instructs a frequency modulator to increase the frequency of the frequency-modulated signal. On the other hand, if the second error signal has been input to the controller a preset number of times or more during an interval before the first error signal is input thereto, the controller instructs the modulator to decrease the frequency of the frequency-modulated signal.

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Kyoto, Japan

Takuji Yoneda