Projection type color liquid crystal optical apparatus
US5754260A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1997 |
| Grant date | May 19, 1998 |
| Priority date | — |
| Expiry date | Feb 27, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3105
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A light source optical system for projection 1, dichroic mirrors 21, 22 disposed to have a predetermined included angle .beta., a reflection type liquid crystal optical element blocks 31-33 each including a closely contacted converging lens and having a reflection surface and a projection optical system 4 are provided, wherein the normal line of a dichroic mirror surface and the optical axis of incident light form an included angle .alpha.; the normal line of the reflection surface and the optical axis of incident light form an included angle .gamma.; light emitted from a light source is color-separated so as to become color lights; the color lights are rendered to be parallel light beams, and are modulated and reflected by means of the reflection type liquid crystal optical elements; the reflected light beams are color-synthesized; and the color-synthesized light is projected through a projection lens. A projection type color liquid crystal optical apparatus having a compact shape and a high brightness is obtainable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.