Patents by Inventor Gerhard Illian

Gerhard Illian 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).

  • Patent number: 5286409
    Abstract: The novel liquid-crystalline mixtures (in the case of ferroelectric behavior they additionally contain an optically active compound as dope) are based on at least two mixture components of the general formula (I) and at least one carboxylate of the general formula (II), (III) or (IV). ##STR1## The mixtures have favorable properties for use in electrooptical display elements, such as high contrast, low melting point and short switching times.
    Type: Grant
    Filed: November 6, 1991
    Date of Patent: February 15, 1994
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hans-Rolf Dubal, Claus Escher, Takamasa Harada, Wolfgang Hemmerling, Gerhard Illian, Ingrid Muller, Mikio Murakami, Dieter Ohlendorf, Rainer Wingen
  • Patent number: 5257122
    Abstract: A ferroelectric liquid crystal switching or display device, in which the liquid crystal film has a constant thickness, wherein one of the glass sheets in the device is planar and the other glass sheet has at least one step. The switching or display device of the present invention does not require shortened switching times or more contacts or drivers and does not show unwanted switching.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: October 26, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hans-Rolf Dubal, Claus Escher, Gerhard Illian, Mikio Murakami, Dieter Ohlendorf
  • Patent number: 5231528
    Abstract: What is described is a surface stabilized ferroelectric liquid crystal display with a layer thickness of 1 to 10 .mu.m containing a ferroelectric liquid crystal mixture having a high spontaneous polarization of P.sub.s greater than 20 nC.multidot.cm.sup.31 2 and a natural helical pitch of less than one half of the layer thickness.
    Type: Grant
    Filed: November 20, 1992
    Date of Patent: July 27, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Claus Escher, Wolfgang Hemmerling, Gerhard Illian, Takamasa Harada, Mikio Murakami
  • Patent number: 5206751
    Abstract: Addition of coronands and cryptands to FLC-mixtures makes it possible to bring the FLC material into a homogeneous "bookshelf" or "quasi-bookshelf" geometry. When such a FLC mixture is used, displays which have been shock-damaged can be regenerated by applying a suitable electric field for a short period of time.
    Type: Grant
    Filed: April 10, 1991
    Date of Patent: April 27, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Claus Escher, Gerhard Illian, Norbert Rosch, Takamasa Harada
  • 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