High contrast illumination system for video projector
US5442414A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 1994 |
| Grant date | Aug 15, 1995 |
| Priority date | — |
| Expiry date | May 10, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/7458
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A high contrast illumination system particularly suitable for use with light valves that have an array of reflective pivotable pixels. The light valve is arranged in light path which extends from a projection lamp to a projection lens. By the action of the pivotable pixels the light is directed either into the projection lens (ON) or away from the projection lens (OFF) to modulate the light with video information. An asymmetric aperture is disposed in the light path with its longitudinal axis located along the pivot axis of the pixels. This configuration provides maximum brightness without adversely affecting contrast. The system may be used in either a monochrome or color (RGB) system and in single or multiple light valve systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.