| 摘要 |
PROBLEM TO BE SOLVED: To deflect a laser optical path according to the rotational irregularity of a photoreceptor drum and to correct the pitch irregularity of scanning lines caused by the rotational irregularity by controlling voltage applied to an optical path deflection means. SOLUTION: A circumferential speed signal is inputted to a correction amount arithmetic circuit 51 from a circumferential speed detection sensor 9 and the correction amount of the laser optical path is calculated so as to correct the irregularity of recording density on the photoreceptor drum in a rotating direction being the sub- scanning direction of a laser beam generated by the circumferential speed irregularity of the photoreceptor drum. Besides, a light position signal is inputted to a light position arithmetic circuit 52 from a light position detection sensor 105 and a light position is calculated. Then, the output of the arithmetic signals of the correction amount and the light position are inputted to a correction feedback circuit 53 and fed back to a controller 22. Thus, the irregularity of space between the scanning lines caused in accordance with the fluctuation of the circumferential speed of the photoreceptor drum is corrected by executing the feedback of fluctuation amount and properly controlling the optical path while monitoring the position of the laser beam where a liquid crystal cell 3 is actually fluctuated. |
