Method and device for compensating undesired variations in an electrical signal generated by an optical code reader
US6871785B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2000 |
| Grant date | Mar 29, 2005 |
| Priority date | — |
| Expiry date | Oct 26, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10851
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The method for compensating undesired variations in an electrical signal generated by a sensor of an optical code reader comprises the steps of generating an envelope signal starting from the electrical signal generated by the sensor and normalizing the electrical signal with respect to the envelope signal. Preferably, the envelope signal is filtered with a low-pass filter before being normalized so as to eliminate steps and edges which may cause distortions during normalization, and the normalized signal is amplified in a controlled way so as to supply an output signal ranging between two values having preset amplitudes. Normalization is carried out by dividing, point by point, the electrical signal by the envelope signal, in the case of continuous analog processing; alternatively, in presence of discrete-time signals, normalization is carried out by subtracting the envelope signal from the electrical signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.