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:
Jul. 24, 1984
Filed:
Feb. 15, 1980
William W Lloyd, Richardson, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A system and method for controlling the effective root mean square (RMS) voltage (Veff) across the segments of a liquid crystal display as a function of the frequency of the voltage signal applied thereto and selected parameters of the display package are described. Display parameters such as the thickness of the barrier dielectric layer and the electrical resistance of the liquid crystal material are chosen so that the ON and OFF states of the display are selectively controllable by lowering the frequency of the drive voltage signal applied to the OFF segments (Foff) a predetermined amount below that of the drive voltage signal applied to the ON segments (Fon), thereby decreasing the ratio of the effective RMS voltage Veff to the RMS voltage of the applied voltage signal (Vapp) for the OFF segments as compared to the ratio Veff/Vapp for the ON segments. The number of drive lines which can be effectively multiplexed is thereby increased. By proper selection of drive frequencies and other display parameters, temperature compensation without the need for additional sensors and circuitry is also achieved.