LED drive for generating constant light output
US7019662B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 29, 2003 |
| Grant date | Mar 28, 2006 |
| Priority date | — |
| Expiry date | Jan 8, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/39
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An LED light source drive includes an LED current generating circuit and an LED drive controller. The current generating circuit is operable to receive power from a power source and to generate a dc current that can be used to the drive an LED light source. The drive controller is operable to control the dc current to ensure that the light output of the light source remains approximately constant over its operating lifetime. In one embodiment, the drive controller ensures that the effective light output of the light source remains approximately constant by automatically increasing the dc current in predetermined amounts at predetermined times. In an alternative embodiment, the drive controller includes an LED light sensor that is operable to generate a light signal indicative of the effective light output of the light source and the controller uses this light signal to control the dc current output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.