Signal processing apparatus and method
US5298728A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 1991 |
| Grant date | Mar 29, 1994 |
| Priority date | — |
| Expiry date | Nov 1, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10851
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A signal processing apparatus and method adapted for use in bar code scanners is described. The apparatus forms a derivative signal, and utilizes the derivative signal to detect transition points from white to black bars and vice-versa. Then, the apparatus starts and stops the generation of digital pulses at or about the transition points, thereby generating pulses having widths corresponding to the widths of the bars making up the bar code symbol. The apparatus is capable of successively scanning a bar code symbol more than once, and varying various processing parameters used in forming the derivative signal over the successive scans, including threshold level, overall bandpass, overall amplification, and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.