Patent · US Expired

Light source unit and display device having luminance control based upon detected light values

US7208713B2 · kind B2 · utility

40Cited by
7References
12Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 30, 2003
Grant dateApr 24, 2007
Priority date
Expiry dateJun 10, 2024

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F1/133628
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A light source unit includes a light source having LED chips for emitting different colors of light and an optical sensor for detecting light from a light mixer. A light source control section controls by feedback control luminance of each of the LED chips according to values detected by the optical sensor. The light source unit also includes a temperature control section for controlling the temperature of the light source. The temperature control section is a feedback control system. Keeping the light source at a constant temperature allows suppressing spectrum changes of the LED chips with temperature, thereby suppressing changes in the luminance and chromaticity of the light source unit.

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