| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of optimizing the rotating action of a rotary polygon mirror while preventing the magnification of a formed toner image from being varied in a main scanning direction and a sub-scanning direction. <P>SOLUTION: While a control section 43 is not in a state of writing out an image (NO at #4), the control section 43 detects rotational phase differences of polygon mirrors 34C, 34M and 34Y with respect to a rotational phase of a polygon mirror 34B (#5) to determine whether or not the rotational phase differences are adequate (#6). When they are not (NO at #6), the control section 43 changes a drive frequency of each of polygon motors 36C, 36M and 36Y (#7) in order to change rotational phases of polygon mirrors 34C, 34M, 34Y on the basis of the rotational phase of the polygon mirror 34B. While the control section 43 is in a state of writing out an image, (YES at #4) and the rotational phase differences are adequate (YES at #6), the control section 43 carries out no changing operation of the drive frequencies of the polygon motors 36C, 36M and 36Y (#8). <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
