<p>The present invention employs LEDs and a liquid crystal shutter driven in synchronization with the position of the photosensitive paper, thereby eliminating image distortion even where the head of the optical printer apparatus is subjected to unanticipated load during scanning by the head. A rotary encoder (320) is provided on the rotating shaft of the motor (310) that drives the optical head (100), and the drive timing for the LEDs (110) and the liquid crystal shutter (150) is synchronized with the output of the rotary encoder. <IMAGE></p>