Patent ID: 6239894
Filing Date: 2001-05-29
Classification: G02B

Abstract:
A scanning optical system comprising:a first optical system for shaping a light beam emitted from light source means to form a line image elongated in the same direction as a main scanning direction;a light deflector which has a deflection surface near an imaging position of said first optical system and deflectively scans an incident light beam in the main scanning direction;a second optical system for forming the light beam deflected by said light deflector into an image on a scanned surface in the main scanning direction; anda third optical system for forming the light beam deflected by said light deflector into an image on the scanned surface in a sub-scanning direction and setting the deflection surface of said light deflector and the scanned surface optically conjugate with each other,wherein the light beam guided by said first optical system is made to strike said light deflector at a predetermined angle with respect to a plane perpendicular to a rotation axis of said light deflector, andan optical axis of said second optical system is set to be parallel to a plane which includes an imaging point of the line image and is perpendicular to the rotation axis of said light deflector, and is also set to shift from a plane, which includes the imaging point of the line image and is perpendicular to the rotation axis of said light deflector, by a predetermined amount in the sub-scanning direction.