Constant optical output illumination system
US8692669B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2007 |
| Grant date | Apr 8, 2014 |
| Priority date | — |
| Expiry date | Sep 27, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/38
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention is an illuminator for CCTV surveillance and security applications that maintains constant optical output from an array of LEDs by employing output compensation, feedback and enhancement. This constant optical output illuminator system enables reliable long-duration low-light imaging and data capture for surveillance and security applications, via an array of LEDs, LED power supply circuitry, and output feedback and compensation circuitry in which a photodetector circuit provides a voltage signal proportional to an amount of light falling on a photosensor and the voltage signal is fed to a drive control circuit for electrical current to the LEDs to achieve a desired optical output as measured by a photosensor voltage setpoint across the photodetector circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.