THIN-FILM COATED POLYGON MIRROR FOR CONTROL THE FINE REFLECTANCE ANGLE

摘要

A polygon mirror having a reflecting surface coated with a thin film for controlling fine displacement of the optical reflection angle is provided to scan the reflected light in both Theta and y directions through thin film coating and to regulate the reflection angle of a y-direction at high precision. In a polygon mirror(100) having at least three reflecting surfaces at the lateral sides, a thin film with different thickness distributions along an axial direction is formed on the reflecting surface in order to make reflection angles(delta1,delta2,delta3,delta4,delta5,delta6) of the reflecting surfaces different from each other and linearly change the reflection angle on each reflecting surface. The thin film is coated with metal or dielectric materials by using vacuum deposition.