| 摘要 |
PROBLEM TO BE SOLVED: To realize improvement of quality of a multicolor image to be formed by superimposing images with plural colors with simple and low-cost structure. SOLUTION: Positions of light beams of each color to scan a sub-scanning position detection sensor are compared with an initial case (initial data) and fluctuation of positions in the sub-scanning direction of images of each color is detected (a step 232). When the direction of positional deviation of each of other colors against positional deviation (fluctuation) of a reference color is the same, page sync setting data to regulate starting time of writing image of the colors with quantity of color positional deviation >3/4 dot against the reference color is corrected by unit of one main scan for the colors (steps 240, 242). When the direction positional deviation of each of other colors against the reference color is in both directions, the page sync setting data to regulate the starting time of writing the image of the colors with the quantity of color positional deviation >=1/2 dot against the reference color is corrected by unit of one main scan for the colors (steps 236, 238).
|
