The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 07, 2003
Filed:
Oct. 22, 2001
Applicant:
Inventor:
Frank Jeroen Pieter Schuurmans, Valkenswaard, NL;
Assignee:
Lümileds USA, San Jose, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B 3/702 ;
U.S. Cl.
CPC ...
H05B 3/702 ;
Abstract
Method and apparatus for controlling an RBG based LED luminary which measures the output signals of filtered photodiodes and unfiltered photodiodes and correlates these values to chromaticity coordinates for each of the red, green and blue LEDs of the luminary. Forward currents driving the LED luminary are adjusted in accordance with differences between the chromaticity coordinates of each of the red, green and blue LEDs and chromaticity coordinates of a desired mixed color light.