Illumination system for optical reader
US5430285A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 1993 |
| Grant date | Jul 4, 1995 |
| Priority date | — |
| Expiry date | Aug 20, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10811
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
There is disclosed an apparatus for illuminating a sensing region having an object therein, comprising a reflector that is elongated in a first plane, the reflector having a width dimension that is less than a width dimension of a sensing region to be illuminated, and further having a first curved profile in the first plane about a center of curvature. In a preferred embodiment the reflector is disposed between the center of curvature and the sensing region. In a second plane which is orthogonal to the first plane and includes the center of curvature, a reflecting surface of the reflector has a second curved profile. A plurality of substantially Lambertian light sources each face the reflector for directing light thereto generally in a direction of the center of curvature for reflection toward the sensing region. The second profile preferably comprises a portion of an ellipse and a light source is disposed substantially at a primary focus thereof. The second profile preferably has a gap for transmitting retroreflected light generated within the sensing region therethrough. An upper portion of the second profile comprises a portion of a first surface of revolution selected from the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.