| US 7,538,315 B2 | ||
| Image forming apparatus and control method therefor | ||
| Yuzo Matsumoto, Abiko (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, (Japan) | ||
| Filed on Aug. 21, 2006, as Appl. No. 11/466,094. | ||
| Claims priority of application No. 2005-252721 (JP), filed on Aug. 31, 2005. | ||
| Prior Publication US 2007/0047085 A1, Mar. 01, 2007 | ||
| Int. Cl. G06F 7/00 (2006.01); H01J 5/16 (2006.01) | ||
| U.S. Cl. 250—236 [347/231; 347/250] | 4 Claims |
| 1. An image forming apparatus which forms an image on a photosensitive member by scanning the photosensitive member forward
and backward in a main scanning direction with a laser beam reflected by a reciprocating movable mirror which reflects the
laser beam emitted from a light source based on image data toward the photosensitive member, comprising:
a rotation direction detecting unit adapted to detect a rotation direction of the movable mirror;
a laser beam detecting unit adapted to detect the laser beam scanning the photosensitive member in the main scanning direction;
and
an image correction unit adapted to weight, on the basis of the rotation direction detected by said rotation direction detecting
unit, image data of two lines along a sub-scanning direction in correspondence with a scanning length after start of laser
scanning for a line of laser scanning to compensate the image to be formed using the movable mirror; correct the image data
and output the corrected image data to said light source for control of its emission,
wherein said image correction unit changes weighting coefficients in proportion to a scanning time after start of a line of
forward or backward laser scanning in the main scanning direction, based on the rotation direction of the movable mirror detected
by said rotation direction detecting unit and a detection of the laser beam by said laser beam detection unit, and generates
the corrected image data for a line of forward or backward laser scanning in the main scanning direction by weighting image
data of two lines neighboring in a sub-scanning direction orthogonal to the main scanning direction with the changed weighting
coefficients to compensate the image to be formed using the movable mirror.
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