Highly efficient and compact frontlighting for polarization-based reflection light valves
US5896232A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1997 |
| Grant date | Apr 20, 1999 |
| Priority date | — |
| Expiry date | Aug 7, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/7491
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical device and a display are disclosed that include an illumination source which provides unpolarized light. An array of polarizing plates have an entrance surface, which receives the unpolarized light at an oblique angle, and an exit surface which provides a polarized light having a first polarization and exiting the array at a substantially perpendicular direction to the exit surface. A light valve selectively rotates the polarized light to form an image forming light, and an imaging lens receives the image forming light and forms an image. Each of the polarizing plates in the array has opposing surfaces that are tilted relative to its entrance and exit surfaces. Each polarizing plate includes a polarizing layer formed on one of the opposing tilted surfaces, and a half-wave optical retardation layer formed on the polarizing layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.