Semiconductor integrated circuit device, optical scanner using same, image forming apparatus using optical scanner, and return light identification method

Abstract

A semiconductor integrated circuit device controlling a first light amount of light emitted from a light source based on a second light amount of light entering a light amount detection part so that the first light amount becomes a target level is disclosed. The semiconductor integrated circuit device includes a comparison part configured to compare a voltage corresponding to the second light amount and a reference voltage corresponding to the target level; and a drive current control part configured to control a drive current supplied to the light source based on the result of the comparison by the comparison part. The drive current control part includes a return light identification part configured to determine whether the second light amount includes a third light amount of return light occurring discontinuously.

Dependencies are inferred from the claim text.