Method for controlling the operation of an optical scanner
US4431912A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1981 |
| Grant date | Feb 14, 1984 |
| Priority date | — |
| Expiry date | Nov 13, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10871
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An optical scanner in a retail store checkout stand includes a single item detector upstream of the scanner window. Output signals from the item detector and from symbol recognition logic are used to open and close a shutter in the beam path of the scanner laser. The shutter is opened and a first time out sequence is started when the beam path is interrupted. A second, short time out sequence is restarted each time a valid symbol is recognized. A third time out sequence of intermediate length supersedes the first time out sequence when the beam path is cleared. The laser shutter is closed and the symbol is transferred to a terminal or controller upon the completion of any active time out sequence or upon recognition of a predetermined number of identical symbols, whichever comes first.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.