Illumination pulsing method for a data reader
US7234641B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 28, 2005 |
| Grant date | Jun 26, 2007 |
| Priority date | — |
| Expiry date | Apr 30, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10732
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Row signals or other typically regular signals generated by an imager during each frame period of the imager are counted to determine when to emit pulses of illumination. Methods in accordance with the preferred embodiments may facilitate synchronization of at least some of the pulses with exposures of the imager, while pulsing visible illumination at a rate in excess of the flicker fusion frequency of human vision, to thereby avoid a flicker effect. Methods in accordance with disclosed embodiments are especially useful for a data reader including an imager when visible illumination is pulsed or when it is desired to pulse one or more illumination sources (whether or not visible) at a constant rate or a minimum rate, wherein the constant or minimum rate of pulses differs from a nominal frame rate of the imager.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.