Method and apparatus for variable retardation and adjusting light channel pathlengths
US7791675B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 5, 2005 |
| Grant date | Sep 7, 2010 |
| Priority date | — |
| Expiry date | May 23, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/136277
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A variable retarder is inserted in one or more light channels of a kernel. The variable retarder is a nematic liquid crystal layer that is energized by an electric field and, for example, the voltage or frequency of the electric field dictates an amount of retardation effected by the variable retarder. The variable retarder either increases or decreases an optical path in which it is inserted relative to a reference. The amount of increase or decrease is utilized to place light paths in the kernel within acceptable tolerances. The acceptable tolerances are, for example, a tolerance of difference-light paths expected by a projection lens of device using the kernel for light modulation. In one embodiment, the variable retarder includes a polymer that can be used to fix a retardation value of the variable waveplate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.