Optical scanner having laser diode as light source

摘要

An optical scanner includes a light source including a laser diode for emitting a laser beam, and an optical deflector such as a rotary polygonal mirror for deflecting the laser beam to thereby produce a scanning laser beam. The laser diode is protected from being overheated by arranging the light source in a heat insulating chamber or by cooling the light source with the air flow circulated by the rotation of the rotary polygonal mirror in cooperation with a curved guide plate.