Projection display
US6854851B2 · kind B2 · utility
29Cited by
1References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2003 |
| Grant date | Feb 15, 2005 |
| Priority date | — |
| Expiry date | Aug 29, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/16
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection display according to the present invention reduces the size of a light beam in the optical path of an illumination optics from the periphery to change the amount of light incident on a video display device and the angle of such incidence, thereby making a plurality of image brightness/contrast combinations selectable. Further, the present invention changes the revolving speed of a projection display cooling fan and the adjustment value settings for the video display device's electrical characteristics in accordance with the aperture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.