Patent · US Expired

Projection display system with at least two reflective light valves

US6636276B1 · kind B1 · utility

27Cited by
6References
40Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 9, 1999
Grant dateOct 21, 2003
Priority date
Expiry dateSep 9, 2019

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N9/3117
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A projection display system includes a light source, wavelength-selective retarder device, first and second reflective light valves (LVs), a polarizing beam splitter (PBS), and a wavelength-selective filtering device. The wavelength-selective retarder device receives a uniformly polarized light from the light source and produces a first dark-state light having a first polarization state at a first set of wavelengths and a second dark-state light having a second polarization state at a second set of wavelengths. The first LV receives the first dark-state light and produces a first bright-state light by rotating the polarization from the first polarization state to the second polarization state. The second LV receives the second dark-state light and produces a second bright-state light by rotating the polarization from the second polarization state to the first polarization state. The PBS, positioned between the wavelength-selective retarder device and the first and second LVs, directs the first and second dark-state lights to the first and second LVs respectively, and also directs the first and second bright-state lights to a screen. A wavelength-selective filtering device receives …

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