Projector and phase difference plate and method of arranging phase difference plate
US7199849B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 2003 |
| Grant date | Apr 3, 2007 |
| Priority date | — |
| Expiry date | Nov 28, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/133638
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Provided are a projector capable of correcting a polarization state properly and improving image quality, a retardation plate being used in a projector or the like and being capable of correcting a polarization state properly, and a method of placing a retardation plate. A quarter-wave plate (22) is placed between a reflective spatial light modulator (21) and a PBS (20). The quarter-wave plate (22) includes a combination of a first retardation plate (41) and a second retardation plate (42) each producing a different phase difference. The phase differences produced by two retardation plates (41), (42) are set to be suitable amounts of phase difference according to a position state, so in spite of the fact that the quarter-wave plate (22) including the combination of two retardation plates, the quarter-wave plate (22) can correct the polarization state properly with performance equal to or higher than that in the case where the quarter-wave plate includes a single plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.