The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 05, 1992
Filed:
Dec. 01, 1989
Ian Coulson, Maidenhead, GB;
Thorn Emi plc, London, GB;
Abstract
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.