Detection of scanning distortion

Abstract

Abstract PURPOSE:To make the detection of the quantity of scanning distortion that changes momentarily in a real time during scanning period by converting the two-dimensional movement of a light beam to one-dimensional movement by the use of a one-dimensional condensing optical system. CONSTITUTION:The light beam of a laser light source 1 is focused via a lens 2 and a mirror 3 to the reflecting mirror surface of a galvanometer 4, and the focal point is set on the centerline of the oscillation of the reflecting mirror. The deflection point of this light is so disposed as to parallel with the plane having the condensing characteristics of a one-dimensional elliptical mirror 5. A one-dimensional sensor array 6 is disposed at the other focal position of the scanning beam by locating the array direction perpendicularly to the scanning plane. Then, the light beam moves only one dimensionally in the array direction of the array 6, and since this on-dimensional movement occurs in the inclination errors of the galvanometer 4, it is detected as the deviation information of the position by the array 6, whereby the change in the quantity of scanning distortion with respect to the optical path length of the light is detected in a real time.

Inventors

• 👤 Masahiro Inota

Bibliographic Details