| 摘要 |
PROBLEM TO BE SOLVED: To correct inclination and curve of a main scanning line, and suppress the occurrence of "streaks" in an extremely easy way, in forming a halftone image with image data having pseudo multiple values.SOLUTION: A controller 11 temporarily stores image data having pseudo multiple values created by performing dither processing to multi-gradation image data in a memory 13 of a writing control unit 12. A shift control unit 14 reads out the image data by dividing for each of predetermined areas in a main scanning direction, shifts the image data in a sub scanning direction for each of the predetermined areas and outputs the resulting data to an LD lighting control unit 20, and corrects inclination and curve of the main scanning line of an image to be formed. The shift control unit 14 receives, from the controller 11, input of information specifying the type of a dither matrix that has been used in the dither processing, and changes a shift amount to shift the image data in the sub scanning direction according to the type of the dither matrix specified by the information. |
