Patent ID: 7652684
Filing Date: 2010-01-26
Classification: B41J,G03G

Abstract:
1. An image forming apparatus for forming an image by scanning on a photosensitive member in a main-scanning direction with a plurality of beams aligned in a sub-scanning direction, comprising: an emitting unit configured to emit the plurality of beams including a first beam from a first light source, a second beam from a second light source and a third beam from a third light source arranged between the first and second light sources; a detection unit configured to detect a first location in which a first test pattern is formed by the first beam emitted from the first light source and a second location in which a second test pattern is formed by the second beam emitted from the second light source; a determination unit configured to, based on a detection result by said detection unit, determine positions of a first pixel and a last pixel in the main scanning direction on the photosensitive member to be formed by the first beam based on the first location detected by said detection unit, and positions of a first pixel and a last pixel in the main scanning direction on the photosensitive member to be formed by the second beam based on the second location detected by said detection unit, wherein said determination unit determines the positions of a first pixel and a last pixel in the main scanning direction on the photosensitive member to be formed by the third beam based on the first and second locations detected by said detection unit without forming a third test pattern by the third beam emitted from the third light source.