Polarization conversion and recycling method and apparatus
US7097315B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 2003 |
| Grant date | Aug 29, 2006 |
| Priority date | — |
| Expiry date | Apr 2, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/286
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method, apparatus and system for polarization conversion and recycling by using a half-pyramid shaped reflector with multiple reflective surfaces, or said reflector assembly, to obtain a desirable polarization rotation effect. The disclosed half-pyramid reflector comprises a plurality of reflective surfaces, which are formed so that an incoming beam passing perpendicularly through the entrant surface is reflected three times inside the device and leaves the exit surface with the direction of polarization being rotated 90 degrees. The preferred embodiments of polarization:conversion systems using the invented apparatus are included. Without employing any waveplate component, the disclosed system is not sensitive to wavelength variations of the light source, temperature changes, and polarization alignment errors. Typical application of this invention includes polarization conversion and recycling for projection systems with polarization dependent spatial light modulation panels, such as LCD (Liquid Crystal Display) and LCOS (Liquid Crystal On Silicon).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.