Switchable color filter using electrically controllable optical retarders
US5714970A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1994 |
| Grant date | Feb 3, 1998 |
| Priority date | — |
| Expiry date | Nov 30, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/133533
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A switchable color filter (11) includes three polarizing filters (12, 14, and 16) and two zero to substantially half-wave optical retarders (36 and 38) and is incorporated in a field sequential display system (10) to provide output states of light of three different colors to form an image in full color. Each one of four preferred embodiments (11, 11a, 11b, and 11c) of the switchable color filter provides the output states of three colors. The third and fourth preferred embodiments (11b and 11c) provide a fourth additional output state of, respectively, white light and light of a color which is a combination of two of the other output state colors. The optical retarders comprise nematic liquid crystal cells (100) having fast relaxation times to operate the display system at video rates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.