Asymmetrical tunnel for spatially integrating light
US6419365B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 2000 |
| Grant date | Jul 16, 2002 |
| Priority date | — |
| Expiry date | Apr 21, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3152
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projector includes a source of polychromatic light that propagates through color filter segments of a color wheel and enters an input aperture of an asymmetrical light integrating tunnel that integrates the filtered light into a uniform pattern at a nonrectangular output aperture of the tunnel. The uniform illumination exiting the nonrectangular output aperture is re-imaged onto a light valve that is mounted obliquely to a longitudinal axis of the tunnel. The image of the nonrectangular output aperture on the light valve compensates for any keystone distortion, illumination overfill and illumination drop-off regions on the light valve, thereby increasing brightness and brightness uniformity across the light valve. The asymmetrical light integrating tunnel may include a trapezoidal input aperture that reduces the time period when adjacent color wheel filter segments are traversing the input aperture, thereby increasing the time period when the input aperture receives light from each single filter segment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.