| 摘要 |
A light deflector has a focusing optical system for focusing a light beam deflected by a light deflector onto an object surface. The focusing optical system comprises, in order from the light deflector, a single anamorphic lens, a single spherical lens having a positive refractive index, and a single lens having a toric surface, the lenses having refracting surfaces having respective radii of curvature indicated respectively by r:1, r:2, r:3, r:4, r:5, r:6 in order from the light deflector. The light deflector meets the following condition: -1.0<r:6Y/r:2Y<-0.3 where Y is a component of each of the radii of curvature in a direction normal to a main scanning direction in which the light beam is deflected. |
