Projector utilizing liquid crystal light-valve and color selection by diffraction
US5231432A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 1991 |
| Grant date | Jul 27, 1993 |
| Priority date | — |
| Expiry date | Dec 3, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3105
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection system which produces a color image on a screen corresponding to an applied color signal. In a preferred embodiment, light beams from a source of white light are separated by a dichroic mirror into two beams, one containing green and the other containing blue and red. The beam containing green illuminates a first active matrix liquid crystal panel which contains electrodes which define a diffraction grating having parameters corresponding to green, and the beam containing blue and red illuminates a second active matrix liquid crystal panel which contains electrodes which form two separate diffraction gratings, one having parameters corresponding to red and the other having parameters corresponding to blue. As each beam passes through its respective LC panel its transmittance is modulated in accordance with video information signals applied to the panels, and the red and blue colors are selected by diffraction. The LC panels are embodied in a schlieren optical system for converting modulations of the LC panels and the colors selected by diffraction into an image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.