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:
Apr. 28, 1981
Filed:
Jun. 15, 1979
Siemens Aktiengesellschaft, Berlin & Munich, DE;
Abstract
An operable liquid crystal display device having threshold energy fields dependent on a finite temperature operating range is provided with a layer of a liquid crystal material positioned between the carrier plates of such device. The liquid crystal material includes a nematic carrier material and at least two doping chiral additives, one of which exhibits a clockwise twisting tendency and the other which exhibits a couter-clockwise twisting tendency. The twisting characteristic for the cholesteric phase has a temperature-dependent pitch and, under certain conditions, a temperature-dependent direction of rotation. With such a multiply-doped liquid crystal material and with the application of a controllable select energy field, such as electricity or magnetism to such material, selective display characteristic data can be generated by, for example, a temperature-independent pitch, a helix inversion, or a pitch which greatly increases or decreases with an increasing temperature within the finite temperature range. In such liquid crystal materials, the threshold field strengths are temperature-constant for different display effects or may be compensated to the temperature-dependency of other magnitudes, such as the temperature drift of a driving module designed as an integrated circuit.