| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect contamination of each mirror surface of mirror surfaces to reduce density unevenness of an image. <P>SOLUTION: A control unit controls, in a first mode, a laser drive device so that a laser light quantity emitted from the laser drive device becomes a common target laser beam quantity (target control voltage Vref) for each mirror surface of mirror surfaces. A difference between the maximum value and the minimum value of input light amount data S310 is calculated. If the difference is smaller than α, difference in reflection light quantity between the mirror surfaces is small, and image formation is started in the first mode. If the difference is equal to or larger than α, the difference in refection light quantity between the mirror surfaces is large, and a second mode is entered. The laser drive device is controlled so that the emitted laser light quantity becomes target light quantities (Vref(1)-Vref(6)) set for each mirror surface of the mirror surfaces. <P>COPYRIGHT: (C)2013,JPO&INPIT |
