Projection display apparatus
US7794093B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 2007 |
| Grant date | Sep 14, 2010 |
| Priority date | — |
| Expiry date | Jun 25, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S385/901
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection display apparatus includes a light source, a light intensity equalizing element, a reflective light valve, a relay optical system, and a projecting optical system; the light intensity equalizing element being an optical device in which a cross-sectional shape in a direction orthogonal to a central axis of the light has four corners; the cross-sectional shape of the light intensity equalizing element being determined in accordance with a rectangular ideal illumination area determined so as to include the image forming area on the reflective light valve, an illumination area on the reflective light valve when a reference light intensity equalizing element is assumed to be used, the reference light intensity equalizing element being rectangular in a cross-sectional shape in a direction orthogonal to the central light ray, and the cross-sectional shape of the reference light intensity equalizing element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.