| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus that can accurately control a rotary angle of a polygon mirror and that can highly precisely control an image writing starting position. SOLUTION: A semiconductor laser 210 emits a laser beam for exposing a photoreceptor drum 22. A polygon mirror 240 deflects the laser beam emitted from the semiconductor laser 210 to scan the surface of the photoreceptor drum 22. A polygon motor 250 rotates the polygon mirror 240. A BD sensor 230 detects the laser beam at an end of the scanning line of the laser beam deflected by the polygon mirror 240. A controller 300 performs PWM conversion to a sinusoidal wave to obtain a driving signal and supplies the driving signal to the polygon motor 250. An angle storage section 360 stores, correspondingly to each face of the polygon mirror 240, the reference sinusoidal wave angle which is a sinusoidal wave angle corresponding to the driving signal when the laser beam emitted from the semiconductor laser 210 is detected by the BD sensor 230. COPYRIGHT: (C)2010,JPO&INPIT |
