| 摘要 |
PURPOSE:To correct the asymmetry of optical scanning and to obtain a highly accurate output image by turnably providing a scanning lens system within a surface where the main light beam of luminous flux generated in accordance with the optical scanning passes through and adjusting the optical scanning state of the surface to be scanned by turning the scanning lens system. CONSTITUTION:The luminous flux made incident on a deflecting and reflecting surface 5a is reflected and deflected, made incident on the scanning lens system 6 having an (f-theta) characteristic and condensed, thus to form a light spot on the surface 7a to be scanned of a photoreceptor drum 7. Besides, the optical scanning of the surface to be scanned 7a is executed in a direction shown by an arrow Q by rotating an optical deflector 5 in a direction shown by an arrow S with a rotary shaft P as an axis. When the assembling error or the parts error in a collimator lens 2, a cylindrical lens 3, a scanning lens 6, the optical deflector 5 or the like is caused, the asymmetry is caused at an optical scanning time and the formed image is deteriorated. In order to correct the asymmetry, the lens system 6 is turned without the main scanning cross section and adjusted so that the luminous flux from the lens system 6 is equally condensed on the surface 7a to be scanned. |
