Patents by Inventor Harald Hirschmann

Harald Hirschmann has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • STN liquid-crystal display
    Patent number: 5997767
    Abstract: The invention relates to supertwist liquid-crystal displays (SLCDs) having very short response times and good steepnesses and angle dependences, and to the nematic liquid-crystal mixtures according to the invention used therein, which are distinguished by the fact that they comprise at least one compound of the formula IA and at least one compound of the formula IB ##STR1## in which R, R.sup.3, R.sup.4 and C are as defined herein.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: December 7, 1999
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Harald Hirschmann, Clarissa Weller, Volker Reiffenrath
  • Supertwist liquid-crystal display
    Patent number: 5976404
    Abstract: Supertwist liquid-crystal displays having excellent properties are obtained if the nematic liquid-crystal mixture comprises at least one compound of the formula I ##STR1## and at least one compound of the formula I' ##STR2## in which Alkenyl is an alkenyl radical having 2 to 7 carbon atoms,R is an alkyl group having 1 to 12 carbon atoms, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by --O--, --CH.dbd.CH--, --CO--, --OCO-- or --COO--,b is 0 or 1, andL.sup.2 is H or F.
    Type: Grant
    Filed: November 28, 1997
    Date of Patent: November 2, 1999
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Harald Hirschmann, Clarissa Weller, Volker Reiffenrath