Abstract: Fast-switching displays with memory properties are provided, which can display digits, symbols, and images, and which contain as chemically and thermally stable ferroelectric liquid crystalline substances, according to the invention, liquid crystalline derivatives which contain a chiral alkyl halide residue corresponding to the general formula ##STR1## are used in mixtures of one another as well as in conjunction with other liquid crystalline or non-crystalline liquid substances.
Type:
Grant
Filed:
February 3, 1988
Date of Patent:
October 17, 1989
Assignee:
VEB Werk fuer Fernsehelektronik im VEB Kombinat Mikroelektronik
Inventors:
Bak G. Yong, Barth Petra, Demus Dietrich, Joachimi Detlev, Barbara Kampa, Saskia Kohler, Kristine Mohr, Reinhard Paschke, Gerhard Pelzl, Ulrich Rosenfeld, Wolfgang Schafer, Klaus-Dieter Scherf, Carsten Tschirske, Wolfgang Weissflog, Horst Zaschke
Abstract: A mixing component for nematic liquid-crystalline substances used in optoelectronic components for the rendition of numbers, symbols and images. The object of the invention is to reduce, in components for nematic liquid crystal substances, the threshold and operating voltages. It has been found, that the addition of one or more 1-oxa-2,6,7-trioxane-1-phospha-bicyclo-derivatives having the general formula ##STR1## wherein ##STR2## with R.sup.1 =C.sub.n H.sub.2n+1 --, C.sub.n H.sub.2n+1 O--, C.sub.n H.sub.2n+1 COO--, C.sub.n H.sub.2n+1 OCOO--, R.sup.2 +C.sub.n H.sub.2n=1 --with n=an integer from 1 to 10to nematic liquid crystal substances, considerably reduces the operating voltage.
Type:
Grant
Filed:
November 28, 1984
Date of Patent:
October 7, 1986
Assignee:
VEB Werk fuer Fernsehelektronik im VEB Kombinat Mikroelektronik
Inventors:
Dietrich Demus, Horst Zaschke, Gerhard Pelzl, Carsten Tschierske
Abstract: The invention relates to the application of nematic liquid-crystalline substances in electro-optical device elements for the display of numbers, symbols and images.Such nematic liquid crystals having low melting points and extremely high temperatures of transparency.The nematic liquid-crystalline substances are 5-alkyl-2-[4-acyloxyphenyl]-pyrimidines having the general formula ##STR1## wherein ##STR2## R.sup.1 =C.sub.n H.sub.2n+1, C.sub.n H.sub.2n+1 O, C.sub.n H.sub.2n+1 OCOO, C.sub.n H.sub.2n+1 COO, C.sub.n H.sub.2n+1 S, F, Cl, Br, NO.sub.2, CN CF.sub.3R.sup.2 =C.sub.n H.sub.2n+1n denotes any of the numbers between 1 and 10.These substituted pyrimidines are used in electro-optical device elements singly or as mixtures of each other, as well as mixtures with other liquid-crystalline or non liquid-crystalline components.
Type:
Grant
Filed:
August 20, 1980
Date of Patent:
January 19, 1982
Assignee:
VEB Werk fur Fernsehelektronik im VEB Kombinat Mikroelektronik
Inventors:
Horst Zaschke, Dietrich Demus, Adalbert Wiegeleben, Uta Bottger
Abstract: Nematic liquid crystals are employed in electro-optical devices for the modulation of the transmittant or incident light and for the black and white or colored rendition of numerals, symbols and pictures.The object of the invention is the use of nematic liquid crystals having a high positive dielectric anisotropy, a low threshold and operating voltage and high clear points and a process for making these compounds.It was found that as liquid crystals for electro-optical devices mixtures are useful which, as an essential component, contain one or several compounds from the class of 5-cyano-2-[4-acyloxyphenyl]-pyrimidines of the formula ##STR1## wherein R.sup.1 is ##STR2## C.sub.5 H.sub.11 -- or C.sub.n H.sub.2n+1 O-- R.sup.2 is C.sub.n H.sub.2n+1 ; C.sub.n H.sub.2n+1 O; C.sub.n H.sub.2n+1 S; F; Cl; Br; CF.sub.3 ; C.sub.n H.sub.2n+1 COO; C.sub.n H.sub.2n+1 OCOO; CN; NO.sub.2 ; C.sub.n H.sub.2n+1 NH; or C.sub.n H.sub.2n+1 (CH.sub.3)N, n is 1 to 10, andR.sup.3 is C.sub.n H.sub.2n+1,n is 1 to 10.
Type:
Grant
Filed:
April 30, 1980
Date of Patent:
November 9, 1982
Assignee:
VEB Werk fur Fernsehelektronik im VEB Kombinat Mikroelektronik
Inventors:
Horst Zaschke, Dietrich Demus, Sylvia Deresch