Sharp Kabushiki Kaisha Corporation

The Secretary of State for Defence in Her Brittanic Majesty's Government

The Secretary of State for Defence in Her Britannic Majesty's Government

Simon David Haslam

John Clifford Jones

Robert William Bannister

A ferroelectric liquid crystal display (FLCD), which comprises a cell including a layer of chiral smetic ferroelectric liquid crystal material contained between two substrates and at least one alignment layer for determining the surface alignment of the molecules in the liquid crystal material, is manufactured as follows. After selection of a suitable material for the alignment layer, the cell is filled by introducing liquid crystal material between the substrates to which the alignment layer is applied. After filling of the cell, a heat treatment is applied to the cell by raising the cell to an elevated temperature and maintaining the cell at that temperature for a predetermined period of time. The temperature and the period of time of this heat treatment are selected to cause the surface alignment properties of the alignment layer to be changed by the heat treatment in such a manner as to promote adoption of the C2 state by the liquid crystal material on subsequent cooling to the device operating temperature.

Liquid crystal devices

In order to promote the formation of the C2 state during manufacturing of a ferroelectric liquid crystal display comprising a cell including a layer of chiral smectic ferroelectric liquid crystal material contained between two substrates. The manufacturing method includes the steps of (a) heating the liquid crystal material and (b) whilst allowing the liquid crystal material to cool from an elevated temperature, which is close to the phase transition temperature to the chiral smectic phase, allowing pressure to the liquid crystal material within the cell by means of rollers in such a manner as to produce mass flow of liquid crystal material within the cell so that the liquid crystal material preferentially adopts the C2 state on cooling to the device operating temperature. This avoids formation of both the C1 and C2 states in the manufactured display which would otherwise result in a patchy appearance, and allows faster switching at lower voltages.

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Wyesham, United Kingdom

Simon David Haslam