Laser beam scanning system

摘要

A laser beam emitted from a laser source is deflected by a light deflector such as a rotational polygonal mirror or a galvanometer mirror to scan a surface-to-be-scanned. A beam position detector detects the incident position of the laser beam on the light deflector, and a control circuit drives an optical path changing mechanism according to the output of the beam position detector to change the optical path of the laser beam upstream of the light deflector so that the laser beam impinges upon the light deflector at the regular position.