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:
Jan. 10, 1984
Filed:
Dec. 14, 1981
Hubert Portmann, 6023 Rothenburg, CH;
Asulab, S.A., , CH;
Abstract
A liquid crystal display cell with thermal compensation of the degree of contrast comprises a measuring capacitor 12, 13 and a reference capacitor formed by two constituent reference capacitors 13, 15 and 14, 15 connected in series. The areas of the surfaces of the electrodes are so selected that the capacitances of the measuring and reference capacitors are approximately equal. The measuring and reference capacitors of the cell can be operated by excitation voltages of the same amplitude. The voltages which then appear at the terminals of the constituent reference capacitors are of lower amplitudes, corresponding to a region of the characteristics in which the capacitance is independent of temperature.