Scanning optical system
AssigneePENTAX Corporation
InventorTakashi Iizuka
Life of this patent
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Abstract
There is provided a scanning optical system, which is provided with a light source, a cylindrical lens that converges the beam emitted by the light source in an auxiliary scanning direction, a polygonal mirror, and an optical element that has a reflection surface to reflect the beam deflected by the polygonal mirror. The optical element converges the beam deflected by the polygonal mirror on the surface to be scanned to form a beam spot. In this case, the cylindrical lens is arranged such that the beam, which enters into the cylindrical lens and exits from the cylindrical lens without being reflected by inner surfaces of the cylindrical lens, is deflected in the auxiliary scanning direction by the cylindrical lens and is incident on the polygonal mirror.
Claims15
A scanning optical system for emitting a beam scanning in a main scanning direction, comprising:
- a light source that emits a beam;
- a cylindrical lens that converges the beam emitted by said light source in an auxiliary scanning direction which is perpendicular to the main scanning direction;
- a polygonal mirror that rotates and deflects the beam emerged from said cylindrical lens to scan in the main scanning direction;
- and
- an optical element that has a reflection surface to reflect the beam deflected by said polygonal mirror, said optical element converging the beam deflected by said polygonal mirror on a surface to be scanned to form a beam spot, the beam spot scanning on the surface to be scanned,
- wherein said cylindrical lens is arranged such that the beam, which enters into said cylindrical lens and exits from said cylindrical lens without being reflected by inner surfaces of said cylindrical lens, is deflected in the auxiliary scanning direction by said cylindrical lens and is incident on said polygonal mirror.
A scanning optical system, comprising:
- a light source that emits a beam;
- a cylindrical lens that converges the beam emitted by the light source in an auxiliary scanning direction;
- a polygonal mirror that deflects the beam from the cylindrical lens to scan within an predetermined angular range;
- and
- an fθ mirror that converges the scanning beam on a surface to be scanned,
- wherein stray light is generated inside said cylindrical lens due to inner reflection thereof, the stray light being emitted from said cylindrical lens on the same side where the beam directed to said polygonal mirror emerges, and
- wherein said cylindrical lens is arranged so that the stray light is spatially separated from the beam directed to said polygonal mirror.
Dependencies are inferred from the claim text.