| 摘要 |
PROBLEM TO BE SOLVED: To provide a light beam scanning control apparatus in which the deterioration of correction accuracy in picture magnification due to variation of characteristic for every element is prevented. SOLUTION: An optical sensor 24 which detects a laser beam and a lens 27 are placed at the beginning position side of scanning on a main scanning line, a mirrors 25 and 26 are placed at the beginning position of scanning and the terminal position of scanning, respectively, the laser beam radiated on the beginning position of scanning is reflected on the mirror 25 and detected with the optical sensor 24. The laser beam which is radiated on the terminal position of scanning is reflected on the mirror 26 and detected with the optical sensor 24. A time interval T between the time when the laser beam is detected at the beginning position of scanning and the time when the laser beam is detected at the terminal position of scanning is measured, and the measured time interval and a reference time interval TO are compared. On the basis of the compared result, a magnification correcting and controlling part 29 varies the frequency of a clock PCLK which decides the rotation of a polygon motor 17, and corrects the picture magnification in the main scanning direction. COPYRIGHT: (C)2007,JPO&INPIT |
