Systems, methods and apparatus for improving the contrast ratio in reflective imaging systems utilizing color splitters
US5986815A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 1998 |
| Grant date | Nov 16, 1999 |
| Priority date | — |
| Expiry date | May 15, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/133553
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for enhancing the performance of reflective LCD systems. The high-contrast color-splitting prism system utilizes a "double-pass" prism assembly. Polarized light enters the prism assembly, is color-split and is emitted as separate colors to reflective imagers which reflect each color in accord with a desired image. The reflected light is passed, once again, through the prism assembly where the separate colors converge and the convergent light is emitted to a projection lens for display of the image on a screen. At least one zero-incidence waveplate compensator is positioned between one reflective imager and the prism assembly. The waveplate compensator effectively decreases the unwanted polarized light entering the prism assembly for the second pass-through, thereby increases the polarization purity of the light that is emitted from the prism assembly to the projection lens to yield a high-contrast projection image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.