Light modulating devices having grey scale levels using multiple state selection in combination with temporal and/or spatial dithering
US6094187A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 15, 1997 |
| Grant date | Jul 25, 2000 |
| Priority date | — |
| Expiry date | Dec 15, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G3/2081
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A ferroelectric liquid crystal display comprises an addressable matrix of pixels, and addressing circuitry for selectively addressing each pixel in order to vary the transmission level of the pixel relative to the transmission levels of the other pixels. The addressing circuitry includes spatial and/or temporal dither circuits for addressing separately addressable subpixels with different spatial dither signals and/or for addressing each pixel or subpixel with different temporal dither signals in separate subframes. In addition to such spatial and/or temporal dither, the addressing circuitry switches each pixel or subpixel between different grey states corresponding to different transmission levels, with at least two of the bits of spatial or temporal dither being switchable between more than two different grey states and at least one bit being switchable between a lesser number of different grey states than the or each other bit, so that a plurality of different overall transmission levels are achievable by different combinations of spatial and/or temporal dither and such grey states. This allows a larger number of substantially linearly spaced or suitably weighted grey levels to …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.