Multiple depth of field laser optical scanner
US5484990A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1993 |
| Grant date | Jan 16, 1996 |
| Priority date | — |
| Expiry date | Dec 15, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2207/1013
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A multiple depth of field optical scanner which produces a plurality of scan beams having different focal distances. The optical scanner includes a laser beam having a centerline, a mirrored spinner having a plurality of facets with different curvatures, a detector, and a microcontroller. The optical scanner may additionally include a deflector mirror for changing the direction of the laser beam, collecting optics for equalizing the optical coupling of the reflected light across the field of view of the facets, a distance selection circuit for instructing the microcontroller within the scanner to decode bar code information from a predetermined range of focal distances and an amplification circuit for amplifying the electrical signals from the detector enough to produce other electrical signals having substantially equal amplitudes. The microcontroller may also include the feature of reducing laser power when the scan beams focus more than a predetermined distance from the centerline of the laser beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.