| 摘要 |
PROBLEM TO BE SOLVED: To control the light output of a laser actually applied to a photoreceptor to a constant even if optical components such as a lens and a mirror are soiled with dust etc. and to attain stable printing quality by providing a means for switching/controlling the light output of the laser in a printing operation mode and a maintenance mode. SOLUTION: The flickering of a visible ray semiconductor laser 4 is controlled by a control part 8. In a maintenance/inspection mode, laser light at a low level is emitted. The light output just before the photoreceptor 2 is measured by a photosensor 13 and stored in a memory part 11 in the control part 8, as reference light output control data. In an arithmetic part 10, arithmetic processing is executed by the reference light output control data obtained in such a way and previously fixed optimum light output just before the photoreceptor 2 under a printing operation, to fix reference light output during a printing operation mode. Then, the output is switched/controlled by a reference light output selecting part 9, to always irradiate the photoreceptor 2 with constant light output. |
