Optical code reader and format
US4980544A · kind A · utility
37Cited by
13References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1990 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Feb 22, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/06028
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An optical code reader system includes an optical code reader and a corresponding optical code format. The code reader includes a detector circuit for establishing an adaptive threshold level related to the difference in successive positive and negative peaks of the analog signal corresponding to white and black areas of the code. The code format comprises a plurality of alternating encoded black and white areas bounded by white quiet zones and black preset areas associated with the quiet zones for presetting the threshold value of the detector circuit to a known level before the code is read.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.