Patent ID: 7663659
Filing Date: 2010-02-16
Classification: G03G

Abstract:
1. An image forming apparatus for forming an image by scanning in a main scanning direction laser beams emitted from a plurality of lasers, the image forming apparatus comprising: a detection unit configured to detect displacement, in a sub-scanning direction, of a main scanning line of a laser beam from one of the plurality of lasers, from a reference position in the sub-scanning direction to determine whether the displacement of the main scanning line of the laser beam from one of the plurality of lasers is upward or downward from the reference position in the sub-scanning direction; a determination unit configured to determine an allotted amount of light for each of the plurality of lasers in accordance with the displacement detected by the detection unit; and a control unit configured to control driving of each of the plurality of lasers in accordance with the allotted amount of light for each of the plurality of lasers determined by the determination unit, wherein the determination unit allots a different amount of light to at least two of the lasers, wherein the plurality of lasers are arranged evenly spaced, not longer than one-pixel length apart from each other in the sub-scanning direction, and spaced a predetermined distance apart from each other in the main scanning direction, and one pixel is formed by overlapping laser beams from the plurality of lasers, and wherein in a case where the displacement detected by the detection unit is upward from the reference position in the sub-scanning direction, the determination unit determines allotment of light to the plurality of lasers in such a way that allotted amounts of light for the lasers situated at lower side in the sub-scanning direction are larger, and in a case where the displacement is downward from the reference position in the sub-scanning direction, the determination unit determines allotment of light to the plurality of lasers in such a way that allotted amounts of light for the lasers situated at upper side in the sub-scanning direction are larger.