Projection-type display apparatus
US6120152A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1997 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | Jan 14, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/7441
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection-type display apparatus includes a light source, a uniform illumination optical system, a color separating system for separating a white light beam emitted from the uniform illumination optical system into three color beams, three liquid crystal panels for respectively modulating each of the separated color beams, a light guide system located on an optical path of the color beam having the longest optical path among the separated color beams, a dichroic prism for synthesizing the beams modulated through the liquid crystal panels, and a projection lens for projecting the synthesized and modulated beam onto a screen. The uniform illumination optical system is provided with a uniform illumination optical device for converting the white light beam emitted from the light source into a uniform beam. Since the dichroic prism, which is an optical element that is rotationally symmetrical about the chief axis of a projection optical system, is employed as a color synthesizing system, and the uniform illumination optical device for restricting unevenness in color and luminous intensity is incorporated in the system, it is possible to realize a display apparatus which causes little…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.