Bar code scanner with DC brushless motor
US4709195A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1986 |
| Grant date | Nov 24, 1987 |
| Priority date | — |
| Expiry date | Sep 12, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2207/1018
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A laser scanner having a rotating mirror, such as a POS scanner as used in supermarkets, uses a closed-loop velocity controlled DC brushless motor for rotating the mirror. In addition to providing a hall effect motor speed signal which is used for monitoring and safety features in association with the scanner, the DC brushless motor provides the advantages of greatly reduced power consumption, decreased temperature rise, less electrical noise in the analog scanner circuitry, reduced cost, and greatly reduced size, sometimes over 80%. The use of the inherent motor speed signal from the DC brushless motor also enables elimination of costly mechanical windswitches as typically used in prior scanners.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.