Light beam scanning apparatus

摘要

A light beam is scanned in the main scanning direction on a scanned face. The light beam is detected by a pair of sensors arranged on the scanned face or a position equivalent thereto and is converted to an electric signal. A processing circuit having a plurality of operational amplifiers corrects electric signals from the pair of sensors based on a correction signal and integrates a difference between these electric signals. A correction amount of the correction signal is set based on a value integrated by the processing circuit and an offset amount present in the processing circuit.