Ferroelectric Liquid Crystal Displays With Gray Scale Using Variable Cell Thickness Conditions
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
Multi-level gray scale can be obtained with surface stabilized ferroelectric liquid crystal displays (SSFLCDs) using variable cell thickness conditions and inhomogeneous surface alignment conditions. In a device using variable cell thickness condition, the ferroelectric liquid crystal is sandwiched between two conducting glass plates which are coated with appropriate alignment materials. We assume, for simplicity, both surfaces are treated to give homogeneous parallel alignment and that the lower plate has a variable thickness A and B. If the threshold voltages required to switch-on the cell A and B, respectively, are set so VA is less that VB, in the switch-on operation by applying a DC voltage V between VA and VB, area A is switched on while area B remains in the off state.