Apparatus for reducing ambient light into an optical print scanner
AssigneeCross Match Technologies, Inc.
InventorsJohn F. Carver, George W. McClurg
Life of this patent
Estimating the term…
Abstract
A light shroud reduces or eliminates the effects of ambient light on an optical fingerprint scanner. Because of the geometry of a prism used in the scanner, ambient light from only certain incidence angles can interfere with an image produced by the scanner. The light shroud blocks this ambient light entering the system at angles which allow the light to interfere with the illumination system or camera. In an embodiment, the light shroud can be closed to act as a cover, protecting the platen surface.
Claims21
An optical print scanning system, comprising:
- a live print scanner having a platen for receiving an object having a print pattern, wherein the platen is the surface of a prism;
- and
- a light shroud,
- wherein the light shroud allows access to the live print scanner by a user while blocking ambient light from entering the live print scanner at angles which may adversely interfere with an image produced by the live print scanner.
An optical fingerprint system, comprising:
- a platen that receives a fingerprint, wherein the platen is a surface of a prism;
- an illumination system that illuminates the platen;
- a camera that images the fingerprint;
- and
- a light shroud, wherein the light shroud allows access to the platen while blocking ambient light from entering at all angles which may adversely interfere with the illumination system or the camera.
A cover for an optical scanning system, comprising:
- a light-blocking shield in close proximity to a platen of the optical scanning system, wherein the platen is a surface of a prism,
- wherein the light-blocking shield has an open position in which the light-blocking shield blocks ambient light from entering the platen from angles that adversely interfere with the optical scanning system when in the open position, and
- wherein the light-blocking shield has a closed position in which the light-blocking shield fully covers the platen.
Dependencies are inferred from the claim text.