Optical systems for bar code scanners
US5332892A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1991 |
| Grant date | Jul 26, 1994 |
| Priority date | — |
| Expiry date | Dec 24, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/14
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention facilitates operation of a bar code reader over a wider range of working angle, a wider range of distances from the bar code and a wider range of bar code densities. The invention includes improved optics and sensing elements. To provide a wider depth of field the optics associated with the emitter and or the photodetector have two distinct focal points. In the preferred embodiments, the optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived form the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data. The data from the channel producing a valid result can be used, or if neither channel produces a valid result by itself, data from each channel can be analyzed and valid portions of the data from both channels combined to produce the single decoded result.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.