Light beam scanning apparatus and image forming apparatus

摘要

A beam position detector output processor (40) converts an output from a beam position detector (38) into beam position information. A main control unit (51) detects a total offset value of a plurality of operational amplifiers constituting the processor (40). The detected offset value is used to compensate a determination reference value used to control the sub-scanning position of a beam, or the beam position information obtained from the beam position detector output processor (40). As a result, the offsets of the operational amplifiers constituting the beam position detector output processor (40) are compensated.