Fujitsu Corporation

Shozo Kobatake

Kiyoshi Kohiyama

Hidenaga Takahashi

Yukio Otobe

Kiyotaka Ogawa

A color image display control apparatus for receiving a composite color picture signal and processing color image data included in the signal. A color picture signal in an analog form included in the composite color picture signal is converted to a digital form by sampling the analog signal at each cycle of a sampling clock, in and analog to digital converter. The digital image data is processed in a digital image processing circuit. Processed digital data is converted to analog data in a digital to analog converter. Information regarding a phase difference between the sampling clock and each horizontal synchronizing signal in the composite color picture signal is obtained. According to the information, a digital image data in a line corresponding to each horizontal synchronizing signal, which was sampled by the sampling clock, is modified so that the influence of the above phase difference on a displayed image of the processed image data is corrected.

Color image display control apparatus with correction of phase

A composite video signal generation method and device comprises circuits for processing a digital signal, by which the circuits can be integrated. The method comprises the steps of calculating a digital luminance signal and two digital chrominance signals combined from digital primary color component signals, balance-modulating a subcarrier by the two digital chrominance signals, and combining the balance-modulated signals and the luminance signal. In the balance-modulation step, a series of phase information values by adding one by one a value of a sampling period of the digital primary color component signal per a subcarrier period is obtained, cosine function values and sine function values are operated in response to the phase information values, and the cosine function values and the sine function values are multiplied by the two digital chrominance signals, respectively. Accordingly, phase information values of the device can be varied, and if the sampling period of the system changes, the digital primary color component signals can be converted to the NTSC signal.

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Kawasaki, Japan

Shozo Kobatake