Light modulating devices
US6417864B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1999 |
| Grant date | Jul 9, 2002 |
| Priority date | — |
| Expiry date | Apr 28, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G3/3629
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
When a ferroelectric liquid crystal display (FLCD) panel is addressed in such a manner as to cause adjacent or successive pixels to display different levels of greyscale, the viewer may perceive a pseudo edge effect caused by the perceived error in the transmission level at the transition between the two grey levels. In order to decrease this perceived error, the panel is addressed such that, at the transition between the two grey levels, for example between the grey levels “3” and “4”, the most significant bit of the addressing scheme incorporates an analogue grey level, for example a half level. This results in a perception level exhibiting a lower absolute error in the relative grey level than would be obtained if no special measures were taken to compensate for the perceived error at the transition. This compensation technique is applicable to addressing schemes utilizing temporal dither (TD) as well as spatial dither (SD).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.