To attain a reading in a shorter time with a comparatively inexpensive configuration by reciprocating a read means, so as to read an image on an original for each one way movement by one color each through color separation.

A home position of a read unit 13 is selected to be an end of a printer section, a moving scanning of a forward path from the end to the opposite end is selected to be a forward direction and a moving scanning on the return path is selected to be a reverse direction, so as to control the count of an address counter 51 and an up-down counter 56. When the count of the up-down counter 56 indicates a final line of the one-way movement scanning, it is decided that reading of one color image is finished, and the scanning is repeated until the reading for three color images is completely finished. Since the image is read one by one color for one-way movement of the reciprocating motion, the number of reciprocating motions required to read the color image into n-colors separation is decreased to n/2 and then the reading is conducted in a shorter time.