| 摘要 |
PURPOSE:To make it unnecessary to provide an optical member for correcting a surface inclination of a rotary polygon mirror in an optical path, by controlling the magnitude of output for ON-state of a light source for every surface, in accordance with the size of the surface inclination of each surface of the rotary polygon mirror, from a position detecting means of each surface of the rotary polygon mirror and a surface inclination angle of each surface of a known polygon mirror. CONSTITUTION:In a beam detector 14, a beam detecting signal Sb of every surface of a rotary polygon mirror 6 is generated, amplified by an amplifier AMPB and becomes a horizontal synchronizing signal BD. This BD signal is inputted to a signal generator CG, and its signal interval is set to a reference timer. Also, the horizontal synchronizing signal BD is inputted as a clock signal CK of a shift register SR. The shift register SR is constituted of (n) bits being equal to the number (n) of mirror surfaces of the rotary polygon mirror 6, and cleared by a pulse CL generated in a reference mirror position M1. Accordingly, when such an initial set has been completed, by setting successively RM1-RMn which has been stored in a RAM of an MPU, to an output DA in accordance with SR1, a laser output control corresponding to a surface inclination of each mirror in the rotary polygon mirror 6 part can be execut ed. |
