Dual mode reflective/transmissive liquid crystal display apparatus
US5986730A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1998 |
| Grant date | Nov 16, 1999 |
| Priority date | — |
| Expiry date | Dec 1, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/133553
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A dual mode liquid crystal display device has a liquid crystal material disposed between a first polarizer and a second reflective polarizer. A light source is disposed behind the second polarizer and an absorbing means is disposed behind the second polarizer in front of the light source. The reflective polarizer may be a wire grid polarizer and reflects one polarization back towards the front of the display to create a bright image. The other polarization is passed by the reflective polarizer and absorbed by the absorbing means. The absorbing means may be a third polarizer and a wave plate for rotating the polarization passed by the second polarizer before absorbing it so that the second and third polarizers pass the same polarization so that the light produced by the light source may also pass through to the front of the display. The absorbing means may also be a removable sheet of absorbing material. A controller selectively activates the liquid crystal to selectively alter the polarization of the light as it passes through. A switch may reverse the manner in which the controller activates the liquid crystal so that the same pattern of bright and dark images is maintained when t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.