Optical scanning apparatus and image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorGenichiro Kudo
Life of this patent
Estimating the term…
Abstract
An optical scanning apparatus, including: a light source; an incident optical system; and an imaging optical system, in which: the imaging optical system includes at least one plastic lens; in a sub-scanning section, principal rays of the beams intersect each other on an optical axis of the imaging optical system; the principal rays intersect each other at different positions between a case of entering a central region of the at least one plastic lens and a case of entering an end region of the at least one plastic lens; and the principal rays entering one of the central region and the end region of the at least one plastic lens intersect each other, and the principal rays entering another of the central region and the end region of the at least one plastic lens intersect each other.
Claims16
An optical scanning apparatus, comprising:
- a light source including a plurality of light emitting points;
- a deflector configured to deflect beams from the plurality of light emitting points in a main scanning direction;
- an incident optical system configured to cause the beams from the plurality of light emitting points to enter the deflector;
- and
- an imaging optical system configured to condense the beams deflected by the deflector onto a surface to be scanned, wherein:
- the plurality of light emitting points are arranged in a sub-scanning direction parallel to a rotation axis of the deflector;
- the imaging optical system comprises a plastic lens;
- in a sub-scanning section that is perpendicular to the main scanning direction, and that includes the sub-scanning direction, principal rays of the beams from the plurality of light emitting points entering one of a central region or an end region in the main scanning direction of the plastic lens intersect each other on an incident surface of the plastic lens or, at a position between the deflector and the plastic lens, on an optical axis of the imaging optical system;
- and
- the principal rays entering another of the central region or the end region of the plastic lens intersect each other on an exit surface of the plastic lens or, at a position between the surface to be scanned and the plastic lens, on the optical axis.
An image forming apparatus, comprising:
- an optical scanning apparatus comprising:
- a light source including a plurality of light emitting points;
- a deflector configured to deflect beams from the plurality of light emitting points in a main scanning direction;
- an incident optical system configured to cause the beams from the plurality of light emitting points to enter the deflector;
- and
- an imaging optical system configured to condense the beams deflected by the deflector onto a surface to be scanned;
- a photosensitive member in which the surface to be scanned is disposed;
- a developing unit configured to develop an electrostatic latent image, which is formed on the photosensitive member by the beams scanning by the optical scanning apparatus, as a toner image;
- a transferring unit configured to transfer the developed toner image onto a transfer material;
- and
- a fixing unit configured to fix the transferred toner image onto the transfer material, wherein:
- the plurality of light emitting points are arranged in a sub-scanning direction parallel to a rotation axis of the deflector;
- the imaging optical system comprises a plastic lens;
- in a sub-scanning section that is perpendicular to the main scanning direction, and that includes the sub-scanning direction, principal rays of the beams from the plurality of light emitting points entering one of a central region or an end region in the main scanning direction of the plastic lens intersect each other on an incident surface of the plastic lens or, at a position between the deflector and the plastic lens, on an optical axis of the imaging optical system;
- and
- the principal rays entering another of the central region or the end region of the plastic lens intersect each other on an exit surface of the plastic lens or, at a position between the surface to be scanned and the plastic lens, on the optical axis.
Dependencies are inferred from the claim text.