Optical scanning apparatus

摘要

The present invention is intended to reduce a f&thetas; correction error by correcting an error of an object scanning speed which is produced because a reflecting point of a laser beam moves on a polygon mirror (12). In an inventive laser scanner (9), laser light emitted from a laser oscillator (10) is condensed into a beam by a condenser lens (11) at first. This laser beam is reflected by a polygon mirror (12) rotated by a scanning section (13) and is reflected again to a photoreceptor (4) by a curved reflecting mirror (14). A curved profile of a reflecting plane of the curved reflecting mirror (14) in the main scanning direction is formed so as to be asymmetrical on right and left bounding about a scanning center point (14c). Thereby, variation of speed for scanning the curved reflecting mirror (14) by the light reflected by the polygon mirror (12) may be canceled by the curved reflecting mirror (14) and a speed for scanning the object may be fixed almost at a predetermined speed. <IMAGE>