| 摘要 |
PROBLEM TO BE SOLVED: To provide a color image forming apparatus which can shorten a time before a polygon motor becomes stable by making small ripples which accompany a rotation speed change of the polygon motor. SOLUTION: The color image forming apparatus forms an electrostatic latent image on a photoreceptor which rotates in a perpendicular direction to beam scanning, by laser beam scanning polarized by a polygon mirror 2 rotation controlled by an external clock. Moreover, the color image forming apparatus has a clock generating block 12 for changing a driving speed of the polygon motor 13 by changing the external clock, and is equipped with the color shift preventing function of matching a write position in a vertical scanning direction of each color and preventing a color shift of output images. The clock generating block 12 has the function of controlling to divide a displacement amount derived by setting or measurement to two of a front half part and a rear half part. COPYRIGHT: (C)2005,JPO&NCIPI |
