Patent · US Expired

LED lighting system

US7067995B2 · kind B2 · utility

80Cited by
3References
29Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 27, 2003
Grant dateJun 27, 2006
Priority date
Expiry dateFeb 20, 2024

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S362/80
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

Method and system are disclosed for compensating for color variations due to thermal differences in LED based lighting systems. The method and system involves characterizing the LEDs to determine what PWM (pulse-width modulation) is needed at various operating temperatures to achieve a desired resultant color. The characterization data is then stored in the microprocessor either in the form of a correction factor or as actual data. When an operating temperature that is different from a calibration temperature is detected, the characterization data is used to adjust the PWM of the LEDs to restore the LEDs to the desired resultant color.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.