Optical projector
US5749641A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1997 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | Jan 14, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/283
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical projector is described that orients its optics engine preferably vertically within an enclosure that is higher than it is wide or deep. The invented optics engine uses a prismatic cube for color separation or beam splitting, with the prismatic elements within the cube being secured within a durable frame that mounts the three color light valves, e.g. twisted nematic liquid crystal display (LCD)-type shutters, in a predefined position and orientation relative to the prismatic cube. In order to improve image quality and brightness, especially of the notoriously difficult-to-reproduce green color, red and blue beams are S polarized, as is conventional, but the green beam is P-polarized. The invented optical projector preferably includes a frame having a footing portion for resting on a support surface, a light source high above the footing portion, optical convolution structure downstream from the light source for reverse-bending downwardly flowing light from the source, light modulation structure near the reverse bend region for infusing the light with image information and for directing modulated light upwardly in a projectable, image-containing stream of light and outwar…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.