Method of driving a ferroelectric liquid crystal shutter having the application of a plurality of controlling pulses for counteracting relaxation

摘要

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.