| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scan apparatus improved in scan speed and scan precision. SOLUTION: In the optical deflector, the mean length RSm of profile elements of a cross section of the deflection surface of a polygon mirror 104 in the sub scan direction is set to be less than to spacing b between spots of the adjacent light beams formed in the sub scan direction of the deflection surface. This makes it possible to prevent a variation in the shape of the spots of the light beams due to the undulation (unevenness) of the deflection surface of the polygon mirror 104. As a result, it is able to accurately scan a face to be scanned in a short time, particularly in the case where many light beams are simultaneously scanned, effectively suppress a decrease of the granularity of images because the dot size composing finally formed images is kept constant. COPYRIGHT: (C)2008,JPO&INPIT |
