Patent ID: 7787166
Filing Date: 2010-08-31
Classification: G02B,G03G,Y10S

Abstract:
1. A method for controlling an image forming apparatus including a first optical scanning portion and a second optical scanning portion, wherein each of the first and second optical scanning portions has a laser emitting unit, a rotatable polygonal mirror arranged to expose and scan a different image bearing member with laser light from the laser emitting unit, and a driving unit arranged to rotate the rotatable polygonal mirror, the image forming apparatus being capable of forming a color image by causing the first and second optical scanning portions to expose and scan the respective image bearing members and to transfer respective images to a moving medium, the method comprising: starting rotation control of controlling rotation of the driving unit of at least one of the first and second optical scanning portions; after starting rotation control of controlling rotation of the driving unit, forming a color image by using the first and second optical scanning portions by rotating the driving units thereof at a first speed in response to an instruction to start image formation of a color image and forming a monochrome image by using the first optical scanning portion by rotating the driving unit of the first optical scanning portion at a second speed different from the first speed without using the second optical scanning portion in response to an instruction to start image formation of a monochrome image; detecting a remaining amount of a developer used in forming the color or monochrome image; and setting a speed for controlling the driving unit of the first optical scanning portion at the first speed or the second speed based on a detection result of the remaining amount of developer.