Illumination optical system with reflecting light valve
US6561656B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2002 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | Feb 7, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/315
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An illumination optical system comprises a light source lamp (1), a light mixing element (3) for mixing light emitted from the light source lamp (1), a DMD element (5) having a plurality of pixels, a transmission optical system (4) for bringing a light-exit surface (3a) of the light mixing element (3) into optical conjugation with a to-be-illuminated surface (5S) of the DMD element (5), and a field lens (6) located in front of the DMD element (5). The focal length of the field lens (6) can be changed so that an illuminance distribution that varies according to the application of the illumination optical system can be achieved on the to-be-illuminated surface (5S).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.