Light source system, optical scanner, image forming apparatus, and light-amount control method

摘要

A light source system includes a splitter that split light beams F0 emitted from a light source into at least light beams FM and light beams FS, and an optical detecting system that guides the light beams FM to a detector. A light component near a light-intensity peak of the light beams F0 in a plane perpendicular to a propagation direction of the light beams F0 is included only in the light beams FS. Accordingly, light beams have a substantially circular or elliptic cross section with the intensity peak near the center. Light at the peak is supplied to the outside, and other light is used to control an amount of light.