Patent ID: 9217863
Filing Date: 2015-12-22
Classification: G02B,G03G

Abstract:
1. A scanning optical system, comprising: a light source comprising a plurality of light emission points; a light deflector for deflecting a light beam in a main scanning direction; an optical element for guiding the light beam emitted from the light source to the light deflector; and a stop for blocking a part of the light beam emitted from the optical element, the following expression being satisfied: where L x is a distance (mm) from the light source to the stop, f col is a focal length (mm) of the optical element, and y LD is a distance (mm) in the main scanning direction between an optical axis of the optical element and a light emission point among the plurality of light emission points, which is farthest from the optical axis of the optical element in the main scanning direction, the following expression being satisfied: where D y is a diameter (mm) of an aperture of the stop in the main scanning direction, and FFP y is a total angle at half maximum (degree) of a far-field pattern of light emitted from the light source, the light emission point which is farthest from the optical axis of the optical element in the main scanning direction satisfying: when an angle (degree) φ y between a marginal ray within a main scanning section of the light beam emitted from the light source and a ray of light of a maximum intensity is defined as follows