Projection apparatus using spatial light modulator with relay lens and dichroic combiner
US6676260B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 2002 |
| Grant date | Jan 13, 2004 |
| Priority date | — |
| Expiry date | Jun 12, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/7441
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital projection apparatus (10) for projection of a multicolor image includes a magnifying relay lens assembly (28) as part of the light modulation assembly (38) for each component color. The relay lens assembly (28) increases the effective f/# of incident light to the V-plate assembly (25) or V-prism assembly (27) that serves as dichroic combiner, used to combine modulated light of each color from each light modulation assembly (38) in order to form the multicolor image. The magnifying relay lens assembly (28) also provides a reduced working distance for the projection lens (32), allowing a lower-cost design and facilitating substitution of the projection lens (32) best suited for a display surface (40).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.