Patent ID: 7889408
Filing Date: 2011-02-15
Classification: G02B,G03G,G06K

Abstract:
1. An optical scanning apparatus, comprising: a light source unit; a deflection unit for deflecting a light beam (Ray an imaging optical system for imaging, on a surface to be scanned, the light beam (Ray wherein the imaging optical system comprises, in an optical path in the following order from a side of the deflection unit: an imaging optical element (G wherein the second reflecting minor (M wherein the second reflecting minor (M where α denotes an oblique incident angle of a principal ray of the light beam (Ray 1 ) in the sub-scanning direction, which enters the deflecting surface of the deflection unit from a direction oblique to the optical axis of the imaging optical system within the sub-scanning section; L 1 (mm) denotes an interval in the optical axis direction of the imaging optical system, between a deflection-for-scanning point O and an optical surface on the surface-to-be-scanned side of the imaging optical element (G 1 ), L 2 (mm) denotes an interval in the optical axis direction of the imaging optical system, between the deflection-for-scanning point O and a reflection point P of the first reflecting minor (M 1 ); h (mm) denotes a length of the imaging optical element (G 1 ) in the sub-scanning direction; σ (mm) denotes an interval in the sub-scanning direction between the deflection-for-scanning point O and a profile center C of the imaging optical element (G 1 ); and θ (degree) denotes an angle, in the sub-scanning direction, between the principal ray of the light beam (Ray 1 ) reflected by a reflection surface of the first reflecting mirror (M 1 ) and a plane perpendicular to a rotational axis of the deflection unit.