Patent · US Expired

Light separation device, blazed grating device, diffraction grating device, and illumination optical system

US7075615B2 · kind B2 · utility

6Cited by
12References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 13, 2004
Grant dateJul 11, 2006
Priority date
Expiry dateJan 15, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B27/0927
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A thin and light optical device satisfactorily separates light components having different properties. A blazed grating is formed on a surface of a flat-plate-shaped transparent substrate, and a separation coating that reflects or transmits incident light according to the properties of the incident light is provided on the blazed grating. The thus obtained optical device offers a function of separating light into reflected light and transmitted light, and also has a function of diffracting or refracting the thus separated light. As the separation coating, a polarization separation film, dichroic film, angle separation film, or chiral nematic liquid crystal layer is used to separate linearly polarized light components having different polarization planes, light components having different wavelengths, light components incident at different angles of incidence, or circularly polarized light components having different rotation directions.

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