Patent · US Expired

Light modulating devices

US6147792A · kind A · utility

9Cited by
6References
11Claims
0Family size

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Inventors

Key dates

Filing dateApr 29, 1999
Grant dateNov 14, 2000
Priority date
Expiry dateApr 29, 2019

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G3/3629
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A light modulating device, such as a ferroelectric liquid crystal display (FLCD) comprises an addressable matrix and modulating elements or pixels and associated circuitry for selectively addressing each element in a series of addressing frames in order to vary the transmission level of each element relative to the transmissions levels of the other elements. Such addressing utilises a temporal dither addressing scheme for addressing at least part of each element within each frame with different combinations of temporal dither signals applied to separately addressable temporal bits within the frame to produce different transmission levels. In order to enable a large number of grey levels to be produced whilst limiting the perceived errors at transitions between different grey levels, the temporal bits are addressed in a first order in a first frame (or in a first spatial location) and in a second order, which is different to the first order, in a second frame (or in a second spatial location). The order in which the temporal bits are addressed may be varied according to a prescribed sequence, for example alternating between successive frames, along each line or between corresponding…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.