Polarization illumination apparatus and projector using the apparatus
US5452128A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 21, 1993 |
| Grant date | Sep 19, 1995 |
| Priority date | — |
| Expiry date | Jan 21, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/283
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A polarization illumination apparatus is constituted by only a light source, light condensing means having a reflection mirror arranged behind the light source, polarization beam splitting means for splitting light emerging from the light condensing means into first and second polarized light components having different directions of polarization, and return means for returning the first polarized light component to the light condensing means. The direction of polarization of the first polarized light component is changed in such a manner that the first polarized light component from the return means is obliquely incident on and reflected by a mirror surface of the reflection mirror. Therefore, a polarization illumination apparatus which can modulate the vibration direction of polarized light without using an optical phase plate, and has high light utilization efficiency, and a projector using the apparatus can be realized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.