Patents by Inventor Karl Pampus

Karl Pampus 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).

  • Electrically conductive polymers and their use as orienting layer in liquid-crystal switching and display elements
    Patent number: 5118538
    Abstract: Switching and display elements based on ferroelectric liquid-crystals often exhibit a pronounced optical hysteresis which results in the appearance of so-called ghost images. This phenomenon can be markedly reduced or even suppressed if at least one of the two orienting layers are in direct contact with the electrodes and is composed of an electrically conductive polymer of the formula (I): ##STR1## in which R.sup.1, R.sup.2 =independently of each other, H, or straight-chain or branched alkyl or alkoxy containing 1-16 carbon atoms, or halogen,X=S, NH,Y.sup.- =BF.sub.4.sup.-, PF.sub.6.sup.-, PO.sub.4.sup.3-, AsF.sub.6.sup.-, SbCl.sub.6.sup.-, SO.sub.4.sup.2-, HSO.sub.4.sup.-, alkyl--SO.sub.3.sup.-, perfluoroalkyl--SO.sub.3.sup.-, aryl--SO.sub.3, F.sup.- or Cl.sup.-, andn is an integer from 4 to 100 andm is an integer from 1 to 30.
    Type: Grant
    Filed: August 3, 1990
    Date of Patent: June 2, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Claus Escher, Hans-Rolf Dubal, Michael Feldhues, Takamasa Harada, Gerhard Illian, Thomas Mecklenburg, Mikio Murakami, Dieter Ohlendorf, Karl Pampus