Polarized light illumination device and projector
US6341867B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 12, 1999 |
| Grant date | Jan 29, 2002 |
| Priority date | — |
| Expiry date | Aug 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 and combining element into two different types of polarized lights. Secondary light source images are formed at locations shifted from each other in an x direction, whereby polarization is aligned in the same single direction. At least two condensing mirror plates of first to third condensing mirror plates are shifted in parallel from the center axis of the polarized light separating and combining optical element so that secondary light source images formed by z-polarized lights (polarized in a z direction) emitted from the first and second light sources are superimposed upon each other, and secondary light source images formed by x-polarized lights (polarized in an x direction) emitted from the first and second light sources are superimposed upon each other. Thus, even though a plurality of light sources are used, the polarized light illumination apparatus can provide high-intensity illumination light using both polarization components without causing an increase in the illumination angle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.