Color variations in a dimmable lighting device with stable color temperature light sources
US7288902B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 1, 2007 |
| Grant date | Oct 30, 2007 |
| Priority date | — |
| Expiry date | Apr 1, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/905
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and system allow a lighting device having light sources with multiple color temperatures to vary a color temperature of the lighting device in response to changing dimming levels. The light sources are non-incandescent light sources, such as light emitting diodes and/or gas-discharge lights. A dimmer circuit provides a dimming signal that indicates a selected dimming level. The lighting device includes a light source driver and a light source driver controller that cooperate to vary drive currents to the light sources in response to the selected dimming level. By varying the drive currents in different relative amounts, the color temperature of the lighting device changes in response to dimming level changes. In at least one embodiment, changes in the color temperature of the lighting device in response to the dimming level changes simulates the color temperature changes of an incandescent light source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.