Patent ID: 6094187
Filing Date: 2000-07-25
Classification: G09G

Abstract:
A light modulating device comprising an addressable matrix of modulating elements, and addressing means for selectively addressing each element in order to vary the transmission level of the element relative to the transmission levels of the other elements, wherein the addressing means includes spatial and/or temporal dither means for addressing separately addressable spatial bits of each element with different combinations of spatial dither signals and/or for addressing at least part of each element with different combinations of temporal dither signals applied to separately addressable temporal bits corresponding to subframes of different periods to produce a plurality of different transmission levels, and state selection means for switching the spatial and/or temporal bits between different states corresponding to different transmission levels in response to different state switching signals, whereby a plurality of different overall transmission levels are obtainable by selection of different combinations of spatial and/or temporal dither signals and state switching signals, characterized in that the state selection means is adapted to switch each of at least two bits of each element between more than two different states, at least one bit of each element being switchable between a lesser number of different states than other bit or bits of each element.