| 摘要 |
PROBLEM TO BE SOLVED: To provide an image formation device that can prevent toner images from being shifted in a vertical scanning direction in a surface image and a rear image and adjust magnification in the vertical scanning direction between the surface image and the rear image.SOLUTION: For a first drawing mode, rotation speed of a polygon mirror of each image formation unit is set to a first speed, and for a second drawing mode, the rotation speed of the polygon mirror of each image formation unit is set to a second speed larger than the first speed. A phase of a light beam detecting signal generated by the image formation unit in the first drawing mode is accorded with a phase of a first reference pulse, and a phase of a light beam detecting signal to be generated by the image formation unit in the second drawing mode is accorded with a phase of a second reference pulse. |
