Catadioptric imaging system
AssigneeRicoh Company, Ltd.
InventorM. Dirk Robinson
Life of this patent
Estimating the term…
Abstract
A catadioptric imaging system combines a rectifying mirror, a lens system and subsequent image processing. This approach can produce a small form factor desktop document imaging system capable of producing high-quality, high-resolution images of paper documents.
Claims55
An offset catadioptric system comprising, in order along an optical path from an object field to a corresponding image field:
- a convex mirror positioned opposite to the object field, the convex mirror defining an optical axis;
- a lens system, wherein the lens system is a zoom lens system;
- and
- an image sensor, the convex mirror and the lens system acting in concert to image the object field onto the image sensor, the image sensor and the object field positioned on opposite sides of the optical axis.
A document imager for imaging 8.5″×11″ and/or A4 documents, comprising, in order along an optical path from an object field for the documents to a corresponding image field:
- a convex rectifying mirror that substantially corrects for distortion between the object field and the image field, the mirror positioned opposite to the object field, the mirror defining an optical axis and separated from the object field by not more than 5″ along the optical axis;
- a lens system;
- and
- an image sensor, the mirror and the lens system acting in concert to image the object field onto the image sensor at a resolution of at least 300 dpi across the object field, the image sensor and the object field positioned on opposite sides of the optical axis.
An imaging system comprising, in order along an optical path from an object field to a corresponding image field:
- a convex mirror positioned opposite to the object field, the convex mirror defining an optical axis;
- a lens system comprising an aperture stop, a first negative lens group, a second positive lens group and a third negative lens group in that order along the optical path, and with no other lens elements between the aperture stop and the third negative lens group;
- and
- an image sensor, the convex mirror and the lens system acting in concert to image the object field onto the image sensor.
An imaging system comprising, in order along an optical path from an object field to a corresponding image field:
- a convex mirror positioned opposite to the object field, the convex mirror defining an optical axis;
- a lens system comprising an aperture stop, a first negative lens element, a second positive lens element, a third positive lens element and a fourth negative lens element in that order along the optical path, and with no other lens elements between the aperture stop and the fourth negative lens element;
- and
- an image sensor, the convex mirror and the lens system acting in concert to image the object field onto the image sensor.
Dependencies are inferred from the claim text.