Patent · US Expired

Polarized light illumination device and projector

US6132047A · kind A · utility

11Cited by
3References
22Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 12, 1999
Grant dateOct 17, 2000
Priority date
Expiry dateAug 12, 2019

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N9/3167
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

In a polarized light illumination apparatus, randomly polarized lights emitted from first and second light sources are respectively separated by a polarized light separating optical element into two different types of polarized light thereby producing three types of polarized light which are polarized in directions perpendicular to one another. The polarized lights are partially returned to the light sources and their polarization directions are rotated. Secondary light source images are formed at locations shifted in an x direction whereby polarization is aligned in the same single direction. Thus, even though a plurality of light sources are used, the polarized light illumination apparatus can emit illumination light using both polarized components without causing an increase in the illumination angle. Furthermore, a projector capable of projecting an image with a very high brightness can be realized.

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