Patent ID: 6847390

Claim:
An image forming apparatus, comprising: a photosensitive member; a light source; an optical unit configured to scan a surface of the photosensitive member with a light beam produced by the light source; a sensor disposed at a side of the photosensitive member and configured to detect a light amount of the light beam from the light source at the side of the photosensitive member before the light beam scans an image region in a main scanning direction on the photosensitive member, and the sensor outputs a detected signal based on the detected light beam; an electronic circuit configured to store data information and to produce a corrected signal based on a stored correction data table including predetermined light amount data of the light source corresponding to various image forming conditions and a start position shift amount data including a plurality of time shift amounts correspounding to the predetermined light amount data; and a controller unit configured to control a light amount of the light source based on the correction data table, wherein a start position on the photosensitive member of the light beam produced by the light source is adjusted based on the detected signal and the corrected signal, and the controller unit is further configured to shift the start position of the light beam on the photosensitive member for image recording when the light amount of the light source detected by the sensor changes from a reference value.