Hand-suportable imaging-based bar code symbol reader employing an automatic light exposure measurement and illumination control subsystem for measuring illumination exposure on CMOS image sensing array and controlling LED illumination array driver circuitry
US7240844B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 2004 |
| Grant date | Jul 10, 2007 |
| Priority date | — |
| Expiry date | Mar 19, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10881
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A hand-supportable digital imaging-based bar code symbol reading system comprises: an automatic object presence detection subsystem; an image formation and detection subsystem employing a CMOS area-type image detection array; an LED-based illumination subsystem employing a LED illumination array for generating a field of narrow-band LED illumination; an automatic light exposure measurement and illumination control subsystem employing LED illumination driver circuitry; an image capturing and buffering subsystem; an image-processing bar code symbol reading subsystem; an input/output subsystem; a narrow-band transmission-type optical filter subsystem; and a system control subsystem for controlling the subsystems. The time duration that the CMOS area-type image sensing array is exposed to narrow-band illumination, from the LED-based illumination array, is managed by controlling the time that the LED-based illumination array generates narrow-band illumination in response to first and second control activation signals generated by the CMOS image sensing array and the automatic object presence detection subsystem, respectively, aboard the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.