Polarizing illumination device and projection display device
US6092901A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1998 |
| Grant date | Jul 25, 2000 |
| Priority date | — |
| Expiry date | Dec 2, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3167
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A polarizing illumination device and a projection display device using the polarizing illumination device improve light utilization efficiency. Polarizing conversion elements are placed so that one of polarizing separation films of a first polarizing conversion element and one of polarizing separation films of a second polarizing conversion element are close to each other and so that effective incident areas and ineffective incident areas are alternately arranged in the x direction. The width WP in the x direction of the effective incident areas and the ineffective incident areas is set to be larger than half of the width WL in the x direction of small lenses in a second lens array. The optical axes of each of small lenses are offset from the lens centers thereof so that partial beams emerging from the small lenses in a first lens array optimally enter the effective incident areas where the partial beams should enter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.