Multifocal holographic scanning system
US4333006A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 1980 |
| Grant date | Jun 1, 1982 |
| Priority date | — |
| Expiry date | Dec 12, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2207/1013
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A holographic scanning system for scanning bar code indicia is disclosed in which the light beam of a laser is directed to a first set of holograms located on a single rotating disc in which each hologram will generate an individual scan beam having a slightly different focal length and direction angle from that of the other holograms. The generated scanning beams are directed on a target area through which passes a label or object bearing a bar code indicia. Each of the scan beams is projected in an overlapping relationship on the target area, thereby providing an enhanced depth of focus enabling a more effective reading operation. The light reflected from the bar code indicia is picked up by a second set of holograms mounted on the rotating disc and focused at a point at which is located an optical detector for use in reading the bar code.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.