Method of using a retarder plate to improve contrast in a reflective imaging system
US6340230B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 2000 |
| Grant date | Jan 22, 2002 |
| Priority date | — |
| Expiry date | Mar 10, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/7441
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for enhancing the performance of a reflective liquid crystal display system. The high-contrast color splitting prism system utilizes a “double-passed” prism assembly. Polarized light enters the prism assembly, is color-split and emitted as separate colors to spatial light modulators which reflect each color in accordance with a desired image. The reflective light is passed, once again, through the prism assembly where the separate colors converge and propagate to a projection lens for display of the image on a screen. A waveplate retarder is positioned between the liquid crystal display and the polarizing element. The waveplate retarder is tilted with respect to the optical axis to eliminate the deleterious effects of the Fresnel reflections at the interfaces of the waveplate retarder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.