| 摘要 |
PROBLEM TO BE SOLVED: To continuously provide a high image quality optical scanner by detecting mirror surface contamination of a rotating polygon mirror at an early stage, performing mirror surface cleaning of the rotating polygon mirror or replacement of the rotating polygon mirror, detecting the decline in the light transmittance of the optical scanner, and cleaning the optical scanner. SOLUTION: The optical scanner has a light source 1 which emits a laser beam 2, the rotating polygon mirror 3 which deflects and scans the laser beam 2 emitted from the light source 1, and a photo sensor 7 which detects the laser beam 2 deflected and scanned by the rotating polygon mirror 3. The optical scanner includes: a peak hold circuit 9 which holds the peak value of a signal detected by the photo sensor 7; an A/D conversion circuit 10 which performs A/D conversion to the value peak-held by the peak hold circuit 9; and CPU 11. When it is detected from the value of the A/D conversion circuit 10 that the output of the photo sensor 7 has been decreasing with time, an alarm that the reflection factor of the mirror surface of the rotating polygon mirror 3 or the light transmittance of the optical scanner is falling is output. COPYRIGHT: (C)2009,JPO&INPIT |
