Light collimator for liquid crystal displays
US6464365B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 2000 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Jul 21, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0046
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A collimator is provided to collimate light from a lambertian light source in which light from a fluorescent lamp is reflected towards an exit slit and in which light which leaves the slit at 180 degrees and is collimated in one direction to +/−1/2 degree. The collimator is utilized in one application to maximize the diffraction efficiency of a diffractive color separator microlens array to increase the brightness of a color liquid crystal display and to increase color saturation. In order to provide collimation, the light exiting the exit slit is collimated by parabolic surfaces of an optical waveguide to provide a beam which has a collimation of +/−3 degrees in one direction. This light in one embodiment is spread out by a reflective array and is further collimated by a cylindrical lens array so that it exits a panel with the required +/−1/2 degree collimation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.