公开(公告)号：EP0749625A1

公开(公告)日：1996-12-27

申请号：EP95909863.0

申请日：1995-02-28

申请人： SECRETARY OF STATE FOR DEFENCE IN HER BRITANNIC MAJESTY'S GOV. OF THE UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND

发明人： HUGHES, Jonathan, Rennie ,  SCATTERGOOD, David, Charles ,  TOWLER, Michael, John Sharp Labs. of Europe

IPC分类号： G02F1 ,  G09G3

CPC分类号： G09G3/3629 ,  G09G2310/0205 ,  G09G2310/06 ,  G09G2310/061 ,  G09G2320/0204 ,  G09G2320/041

摘要： The invention provides an addressing scheme with temperature compensation for temperature induced changes in liquid crystal material switching parameters. Temperature compensation is provided by measuring liquid crystal temperature, and varying the length of strobe waveforms accordingly. A ferroelectric liquid crystal cell is addressed by row and column electrodes forming an x,y matrix of display elements. A strobe waveform is applied to each row in sequence whilst appropriate data waveforms are applied to all the column electrodes. At each display element the material receives an addressing waveform to switch it to one of its two switched states depending upon the polarity of the addressing waveform. The data waveforms are e.g. alternating positive and negative pulses of period 2ts. The strobe waveform has a zero for one time period ts followed by a unipolar voltage pulse of significant duration e.g. equal to or greater than 0.25 ts or more. This may result in an overlapping of addressing in adjacent rows, e.g. the end of a strobe pulse on one row overlaps with the beginning of a strobe pulse on the next row. The display elements may be switched into one of their two states by one of two strobe pulses of opposite polarity. Alternatively a blanking pulse may switch all elements to one state and a strobe used to switch selected elements to the other state.