Luminance control for illumination devices
US8749172B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 8, 2011 |
| Grant date | Jun 10, 2014 |
| Priority date | — |
| Expiry date | Dec 3, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/22
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An illumination device is provided having one or more illumination LEDs configured to provide illumination for the device. Along with the illumination LED is a reference LED. The illumination LED provide illumination during normal operation of the device, whereas the reference LED provides a reference illumination, but does not provide illumination during normal operation. A light detector can detect light from the illumination LED and the reference LED, and control circuitry can be used to compare light detected from the reference LED and the illumination LED to adjust a brightness for the device. The light detector can comprise a photo-detector or can comprise an LED, such as one of the illumination LEDs if more than one illumination LED is utilized. A method is also provided for controlling brightness of an illumination device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.