High brightness full color image light valve projection system
US4127322A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1975 |
| Grant date | Nov 28, 1978 |
| Priority date | — |
| Expiry date | Dec 5, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3105
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There is disclosed an electro-optical system for real time projection of very high brightness, full color pictorial images from television or other program sources onto a large display screen from a set of three reflection type AC driven field effect mode birefringent liquid crystal light valves each of which modulates a primary color component video image onto a collimated beam of polarized light of a given primary color by modulating the polarization state thereof. In order to achieve very high brightness without overheating the system it is necessary that none of the optical elements forming the projection beam optical system absorb light in carrying out their function. Hence all projection beam optical processes are non-absorptive to first order. The light valves are devices that receive and reflect projection light from an independent high power light source while modulating onto the reflected light video images derived from a low level light source such as a cathode ray tube. The modulation onto the projection beam is achieved by modulating the state of polarization thereof. One such device is used for the red portion of the video image, a second for the green portion and a t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.