VIDEO DEVICE HAVING IMAGE MEMORY FUNCTION

PROBLEM TO BE SOLVED: To obtain a video device having an image memory function, which realizes writing and reading of a plurality of times by using one memory with one port, such as an SRAM and a DRAM without using a dedicated video field memory with three ports. SOLUTION: A video signal for one horizontal scan period written in a write buffer memory 3 is read by a control signal of a memory input/output control circuit 9 in a frequency which is three times as high as that of an input video signal and written to a one-port memory 2. Also, to read an area respectively necessary for 1st and 2nd read signals among video signals written with one field before the memory 2, one horizontal scan period of a necessary area is read from the memory 2 at a frequency which is three times as high as that of the input video signal by a control signal of the circuit 9 and written to corresponding 1st and 2nd read buffer memories 5 and 7 by the control signal of the circuit 9.