Color image processing apparatus with memory interface synchronization between image scanner and printer operations

Claim 1

A color image processing apparatus comprising: color scanning means for scanning an original image and generating a scanning clock signal and for generating a scanning top signal synchronously with a scanning operation; printing means for printing a printed image corresponding to the original image and generating a printing clock signal synchronously with a printing operation, and a printing top signal, said scanning clock signal and said printing clock being different from each other; an image memory into which signals from said color scanning means respectively corresponding to plural colors are written in accordance with the scanning top signal and from which the signals to be transmitted to said printing means are read in accordance with the printing top signal, said image memory being arranged such that a signal for a writing operation and a signal for a reading operation are substantially simultaneously input; and a memory control unit for addressing said image memory in the writing operation or the reading operation of said image memory, wherein said memory control unit includes a writing address counter for counting the scanning clock signal, a reading address counter for counting the printing clock signal, and control means for controlling said writing address counter and said reading address counter such that image data is read from said image memory before writing of the image data into said image memory is completed.