Thorn Emi Plc

Stc, Inc

The Secretary of State for Defence

Ian Coulson

Paul W Surguy

Peter W Ross

Matthew F Bone

Christopher J Morris

Frances C Saunders

Johnathan R Hughes

A method of addressing a display device comprising a matrix of separately operable pixels is provided. The method comprises the step of applying across a given pixel a voltage waveform comprising a latching pulse and an auxiliary pulse of amplitude smaller than the latching pulse. The amplitude of the auxiliary pulse is modulated to determine the latching effect of the latching pulse.

Display device incorporating separately operable pixels and method for

A ferroelectric liquid crystal device has a first state (T.sub.X1) of maximum transmission, a second state (T.sub.X2) of minimum transmission and a value of voltage pulse width (t.sub.S) and voltage pulse height (V.sub.S) sufficient for a switching pulse to switch the cell from the first state (T.sub.X1) to the second state (T.sub.X2) or vice versa. A method of controlling the transmission of electromagnetic radiation through the ferroelectric liquid crystal device comprises the step of applying, for a time period greater than said value of pulse width (t.sub.S), a plurality of consecutive controlling pulses of one polarity. Each controlling pulse is itself of insufficient pulse height and pulse width to switch the cell from the first state (T.sub.X1) to the second state (T.sub.X2) or vice versa.

Method of driving a ferroelectric liquid crystal shutter having the

A method is disclosed for addressing a matrix-array type liquid crystal layer. The cell has a plurality of pixels which are defined by regions of overlap between two sets of electrodes which sandwich a liquid crystal layer, each pixel having two states. The response time for switching between the two states is dependent upon the voltage across the liquid crystal layer, with a minimum occurring at a particular voltage. The method includes applying a strobe waveform to a selected member of a first set of the electrodes while a data waveform is applied to each member of the second set of electrodes. A waveform for switching a pixel defined by the selected member comprises a switching pulse of a given voltage magnitude and given duration. A waveform for not switching a pixel defined by the selected member comprises a non-switching pulse of a voltage magnitude greater than the given voltage magnitude of the switching pulse and a duration less than the given duration of the switching pulse.

Method of addressing a ferroelectric liquid crystal display

A method is provided for addressing a matrix-array type liquid crystal cell with a ferroelectric liquid crystal layer having a plurality of pixels defined by areas of overlap between members of a first set of electrodes on one side of the liquid crystal layer and members of a second set of electrodes on the other side of the liquid crystal layer, each of the pixels having a first and a second optically distinguishable state and a response time for switching between the two states which depends on the potential difference across the liquid crystal layer. The method includes the step of applying a switching pixel waveform to a selected pixel to switch it between the two states. The switching pixel waveform is charge-balanced and comprises a first pulse having a sufficient pulse width and pulse height magnitude to switch the selected pixel and a second pulse contributing to charge-balancing. The second pulse has a pulse height magnitude greater than the sufficient pulse height magnitude of the first pulse and a pulse width which is insufficient to switch the selected pixel.

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Maidenhead, United Kingdom

Ian Coulson