| 摘要 |
PROBLEM TO BE SOLVED: To prevent DMA noise from being superimposed on a video signal. SOLUTION: A CCD receiving a horizontal transfer pulse or the like provides an output of a video signal. An analog signal processing is applied to the video signal to convert the video signal into image data. The image data are written in a line memory in a digital signal processing circuit, subjected to digital signal processing therein and again written in the line memory. The image data written in the line memory are read and subjected to DMA transfer to a memory via a data bus. Application of the horizontal transfer pulseϕH to the CCD is stopped for a time (t12 to t13, t14 to t15, and t16 to t17 or the like) when the image data are subjected to DMA transfer from the line memory to the memory. Superimposition of the DMA noise on the video signal outputted from the CCD is prevented. COPYRIGHT: (C)2005,JPO&NCIPI
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