JPS6413113A - Scanning optical device - Google Patents

Abstract

PURPOSE:To scale down a device and to uniformize an exposing amount of luminous energy by providing a beam reflecting means which reflects plural laser beams in different directions and exposes beams in different positions in the sub-scan direction of an object to be scanned. CONSTITUTION:The laser beams LA and LB emitted from a laser 1 are exposed and scanned on a photosensitive body 3 as an object to be scanned by a polygon mirror 2 (deflecting means) as a polarizing means. Points A and B where the laser 1 emits light can be independently controlled in terms of their light quantities, which can be modulated according to different pieces of graphic information. The laser beams LA and LB reflected by reflecting faces of a prism-like mirror (beam reflecting means) are oriented toward the photosensitive body 3 through bending mirrors 8a and 8b. Images can be formed in a position away from the subscan direction of the photosensitive body 3 by cylindrical lenses 9a and 9b so that the prism-like mirror 7 and the photosensitive body 3 are in conjugate relationship. Thus the device can be scaled down, and unevenness of the exposing amount of luminous energy can be eliminated.