Bar code reader and reading method using single laser light source for both reading information and measuring distance
US5426288A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1993 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | Sep 23, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10851
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An optical information reading method and device which prevents the generation of erroneous reading by specifying a reliable reading range for a bar code or like information. A microcomputer calculates the distance between the position of reflection of laser light from the bar code and a position at which the same laser light enters the scanning unit based on a time difference between the emission of the laser light and the reception of the reflected laser light. The microcomputer determines, through the calculation process, that the bar code is present within the suitable reading range only when the calculated distance is determined to be within the set reading range, and permits the scanning of the bar code.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.