发明授权
US5793515A Optical scanning apparatus 失效
光学扫描装置

Optical scanning apparatus
摘要:
An optical scanning apparatus includes: a rotational polygonal mirror, on the side of which a plurality of reflecting surfaces are provided, the reflecting surfaces deflecting a beam of incident light in the primary scanning direction at a substantially equal angular velocity; a first optical system for forming a beam of light sent from the light source into an image long in the primary scanning direction in such a manner that the formed image strides over the plurality of deflecting surfaces; and an f.theta. lens for converging the beam of light deflected on the deflecting surface at a position close to the surface of the photoreceptor drum so that a spot of light irradiated on the photoreceptor drum can be moved at a substantially equal speed. In the optical scanning apparatus, the angles .alpha. and .beta. satisfy the following expression: (cos((.beta.+.alpha.).div.2)).div.(cos((.beta.-.alpha.).div.2)).gtoreq.0.75where .alpha. is the maximum deflection angle of the deflection luminous flux with respect to the optical axis of the f.theta. lens, and .beta. is an angle formed between the optical axis of the first optical system projected in the subsidiary scanning direction and the optical axis.
公开/授权文献
信息查询
0/0