Contrast and brightness enhancing apertures for illumination displays
US7029130B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 2003 |
| Grant date | Apr 18, 2006 |
| Priority date | — |
| Expiry date | Dec 30, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/315
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention is particularly useful for projection systems in which portions of an unwanted light beam overlap with the image beam. Such an overlap reduces the image contrast. Under the present invention, an aperture is used to restrict the extent of the unwanted beam while an integrator changes the shape of the light beam illuminating the image display device. The integrator changes the illumination beam so as concentrate the light in those areas of the illumination beam that are transmitted through the aperture. When the aperture and the integrator are used together in the projection system, both the image brightness and the image contrast are increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.