Bar code reader for sensing at an acute angle
US5406060A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 6, 1993 |
| Grant date | Apr 11, 1995 |
| Priority date | — |
| Expiry date | May 6, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/14
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Apparatus for illuminating a bar code at a relatively shallow (i.e., acute) angle, and for sensing the light reflected from the surface at the shallow angle. In one embodiment the apparatus is used to illuminate the data bars at an acute angle along their length. Viewing the illuminated area at an acute angle, equal to the acute angle of incidence, increases the area being viewed and tends to spatially integrate the non-uniformity of the data bars. Apparatus embodying the invention is particularly useful for reading bar codes formed on a highly reflective surface. The shallow angle of illumination increases the contrast between the surrounding surface and the "data bars" of the bar code as it increases the effective area being viewed and enables the bar code to be read more accurately. In some embodiments a laser light spot is swept at an acute angle across a bar code and the light reflected from the bar code is viewed at the acute angle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.