Lifetime correction for aging of LEDs in tunable-white LED lighting devices

Patent metadata

Field	Value
Publication number	US-9167656-B2
Application number	US-201313972309-A
Country	US
Kind code	B2
Filing date	Aug 21, 2013
Priority date	May 4, 2012
Publication date	Oct 20, 2015
Grant date	Oct 20, 2015

Abstract

A lighting system having at least three light sources receives an input relating to color coordinates of a target point representing a desired color characteristic for a combined output from the light sources. The system provides color tunable output and/or dimmable output in response to differences in user input. The system also corrects changes in performance of the light sources due to lifetime degradation in each of the light sources. After a period of system operation, outputs of the sources are measured. The system increases the luminosity outputs of each of the light sources by a respective amount relative to the degradations measured in all the light sources; in this manner, the luminosity outputs of the light sources remain substantially constant in relations to each other over the lifetime of the light sources.

First claim

What is claimed is:

1. A method for controlling a multi-color lighting system for combining light from multiple solid state light sources of the system, each configured for producing light of a different color characteristic, each light source comprising one or more light emitting diodes (LEDs), the method comprising the steps of:
for a period of operation, selectively controlling drive currents supplied to the LEDs of the multiple solid state light sources to produce a combined l…

Assignees

• Abl Ip Holding Llc

Inventors

• Raj Rashmi K
• Rogers Jason W

Classifications

• H05B45/20

  Electricity · mapped topic

• H05B45/22 Primary

  Electricity · mapped topic

• G09G3/32

  Physics · mapped topic

• G09G3/30

  Physics · mapped topic

• H05B33/0869 Primary

  Electricity · mapped topic