Optical scanner having a multi-surfaced lens arrangement for producing a rotationally symmetric beam
US4675531A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1985 |
| Grant date | Jun 23, 1987 |
| Priority date | — |
| Expiry date | Mar 28, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10762
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An optical element that is particularly suitable for use in the optical system of a hand-held probe to conduct light to and from bar codes as they are scanned or read for information. The element preferably is integrally formed as a single piece fabricated of optical plastic by injection molding and includes three surfaces, one of which in preferred form is decentered with respect to the element optical axis and forms with another surface an opposed pair used to control the output of a source to illuminate bar codes. The remaining surface, the third, is prismatic, either converging or diverging as required, and is structured to cooperate with part of one of the paired opposed surfaces to conduct light reflected from a bar code to a small photodetector for conversion to electrical form. Overcorrected spherical aberration is used to control the intensity, depth, and surface coverage of illumination so that the probe performance does not change for bar codes positioned anywhere throughout a predetermined working depth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.