Optical scanning apparatus

摘要

In an optical scanning apparatus for causing a luminous flux from a rotary polygon mirror 4 to form an image on a surface to be scanned 6, a concave lens 5a functions not only as one constituent of an f theta lens with respect to the luminous flux scanned by the rotary polygon mirror 4 but also as a cylindrical lens for forming a linear image in the vicinity of a deflecting and reflecting surface of the rotary polygon mirror 4 with respect to a luminous flux from a laser light source 1. The luminous flux directed from the light source 1 to the rotary polygon mirror 4 is passed through the concave lens 5a such as to intersect the optical axis of the f theta lens.