OPTICAL SCANNER AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an optical scanner in which the rotation of a beam spot on a surface to be scanned caused when a light beam is made incident diagonally with respect to a deflection mirror face is suppressed and the surface to be scanned is scanned with the light beam with an excellent scanning characteristic, and to provide an image forming apparatus using the optical scanner. SOLUTION: The dimension Hb of the deflection mirror face 651 and the dimension Hbs of the beam spot BSi on the deflection mirror face 651 satisfy the following two conditions: (1) the spot dimension Hbs of an incident light beam Li on the deflection mirror face 651 is not larger than the width Hb of the deflection mirror face 651 when the angle between the optical axis OAi of the incident light beam Li and a reference line SL is a right angle; and (2) the spot dimension Hbs of an incident light beam Li on the deflection mirror face 651 is larger than the width Hb of the deflection mirror face 651 when the above mentioned angle becomes maximum or minimum. COPYRIGHT: (C)2005,JPO&NCIPI