Patents Assigned to Lümileds USA
  • Method and apparatus for sensing the color point of an RGB LED white luminary using photodiodes
    Patent number: 6630801
    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.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: October 7, 2003
    Assignee: Lümileds USA
    Inventor: Frank Jeroen Pieter Schuurmans