Holographic laser scanning system for carrying out light collection operations with improved light collection efficiency
US6547144B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1999 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Dec 23, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2207/1018
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A holographic laser scanning system for carrying out laser beam scanning operations with improved light collection efficiency. The holographic laser scanning system comprises: a housing of compact construction; a plurality of laser beam sources; a holographic scanning disc supporting a plurality of holographic optical elements having fringe structure of variable spatial frequency; a plurality of laser beam folding mirrors disposed about the holographic scanning disc; a plurality of light focusing surfaces disposed below the holographic scanning disc; and a plurality of photodetectors disposed at the focal points of the light focusing surfaces. During laser beam scanning operations, each laser beam is transmitted through the outer edge portion of each holographic optical element at an angle of incidence. During light collection operations, a portion of the laser light rays reflected off a code symbol scanned by a produced laser scanning plane is collected over the total surface area of the holographic optical element producing the laser scanning plane. The collected laser light rays are focused by the light focusing surface to the respective photodetector, for detecting the intensit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.