IMAGE SIGNAL PROCESSOR

ABSTRACT OF THE DISCLOSURE An image signal processor includes a memory device for storing an image signal representative of a picture during one field period, an operating unit for generating a READ-OUT command necessary to read out contents stored in the memory device, a selector for selectively switching the memory device between a WRITE-IN READY condition and a READ-OUT READY condition, and a switching control unit for generating a control signal necessary to control the switching operation of the selector. The switching control unit is adapted to receive the READ-OUT command and a vertical synchronizing signal included in a composite video signal. The selector performs the switching operation in synchronism with the initial vertical synchronizing signal applied immediately after the READ-OUT command has been inputted.