Holographic laser scanner for producing a highly-defined three-dimensional scanning volume having multiple focal regions within which the laser scanlines are spatially confined
US6375074B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1999 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Feb 17, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2207/1018
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A holographic laser scanner for scanning bar code symbols, in which a plurality of scanning planes are projected through a plurality of different focal regions in order to provide, at each such focal region, a plurality of scanlines that are substantially confined within the highly-defined 3-D scanning volume of the holographic laser scanner. This remarkable capability of the system ensures that the scanlines of the holographic scanner extend only where scanning is required (e.g., within the highly-defined 3-D scanning volume). This avoids scanning regions of space where bar code symbols are known to not be present, or collecting scan data from such “empty” regions of space. By virtue of the present invention, the highly-defined 3-D scanning volume of the holographic laser scanner can be easily positioned above a doorway, conveyor belt, loading dock or the like where objects bearing bar code symbols are expected to pass.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.