Patents by Inventor Waltraud Fehrenbach

Waltraud Fehrenbach 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: 7656490
    Abstract: An electro-optical display device comprising a liquid crystal layer achieves switching using an electric field component which is predominantly parallel to the surface of the liquid crystal layer. Low dependence of image contrast on viewing angle is achieved by selection of parameters including pretilt angle ?0, orientation angle ?0, etc. of the liquid crystal molecules in the layer.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: February 2, 2010
    Assignee: Merck Patent Gesellschaft
    Inventors: Gunter Baur, Waltraud Fehrenbach, Barbara Weber Ne Staudacher, Friedrich Windscheid, Rudolf Kiefer
  • Publication number: 20020060761
    Abstract: The invention relates to an electrooptical system according to the preamble of claim 1, where the angle &psgr;, which the polarization device forms on the input side with the directors of the liquid-crystal molecules on the 1st substrate surface, is optimized in order to achieve high contrast and/or high brightness and/or high viewing angle independence and/or the color values.
    Type: Application
    Filed: July 23, 2001
    Publication date: May 23, 2002
    Applicant: Merck Patent GmbH
    Inventors: Bernhard Scheuble, Gunter Baur, Waltraud Fehrenbach, Barbara Staudacher
  • Patent number: 6327010
    Abstract: An electrooptical system contains: (a) a twisted nematic liquid-crystal layer, with an input side and an output side, which is positioned between a first substrate and a second substrate, each of whose inside surface is provided with an electrode coating and an alignment layer thereon, the director of said liquid crystal layer having a parallel edge alignment and a twist angle of 0°≦&bgr;≦1000, (b) at least one compensation layer for compensating the optical path difference of the liquid-crystal layer d·&Dgr;n, and (c) at least one device for linear polarization of light in such an arrangement that light, before entering and after exiting the liquid-crystal layer, passes through a polarization device, I.
    Type: Grant
    Filed: December 19, 1996
    Date of Patent: December 4, 2001
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Bernhard Scheuble, G√ľnter Baur, Waltraud Fehrenbach, Barbara Staudacher
  • Patent number: 5841499
    Abstract: An electro-optical display device comprising a liquid crystal layer achieves switching using an electric field component which is predominantly parallel to the surface of the liquid crystal layer. Low dependence of image contrast on viewing angle is achieved by selection of parameters including pretilt angle .alpha..sub.0, orientation angle .beta..sub.0, etc. of the liquid crystal molecules in the layer. Reflection mode devices are described.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: November 24, 1998
    Assignee: Merck Patent Gesellschaft Mit Beschrankter Haftung
    Inventors: Gunter Baur, Waltraud Fehrenbach, Barbara W. Ne Staudacher, Friedrich Windscheid, Rudolf Kiefer
  • Patent number: 5841498
    Abstract: An electro-optical display device comprising a liquid crystal layer achieves switching using an electric field component which is predominantly parallel to the surface of the liquid crystal layer. Low dependence of image contrast on viewing angle is achieved by selection of parameters including orientation angle .beta..sub.o, and others, of the liquid crystal molecules in the layer.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: November 24, 1998
    Assignee: Merck Patent Gesellschaft Mit Beschrankter Haftung
    Inventors: Gunter Baur, Waltraud Fehrenbach, Barbara Weber Ne Staudacher, Friedrich Windscheid, Rudolf Kiefer
  • Patent number: 5576867
    Abstract: An electro-optical display device comprising a liquid crystal layer achieves switching using an electric field component which is predominantly parallel to the surface of the liquid crystal layer. Low dependence of image contrast on viewing angle is achieved by selection of parameters including orientation angle .beta..sub.o and pretilt angle .alpha..sub.o of the liquid crystal molecules in the layer. For example, good results are achieved when 0.degree.<.beta..sub.o .ltoreq.20.degree. for liquid crystal molecules having negative dielectric anisotropy and 70.degree..ltoreq..beta..sub.o <90.degree. for molecules having positive dielectric anisotropy. Preferably, 0.degree..ltoreq..alpha..sub.o <30.degree..
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: November 19, 1996
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Gunter Baur, Waltraud Fehrenbach, Barbara Weber nee Staudacher, Friedrich Windscheid, Rudolf Kiefer
  • Patent number: 5188758
    Abstract: The invention relates to an electrooptical display element which can be multiplexed, has two support plates which, with an edging, form a cell containing a pneumatic liquid crystal material with positive dielectric anisotropy, and at least one chiral additive, and has a small surface tilt angle and a twist angle with a value between 150.degree. and 250.degree., wherein the ratio of the elastic constants for bending and twisting K.sub.3 /K.sub.2 of the liquid crystal material and the twist angle are such that when using liquid crystal material with the ratio of the elastic constants K.sub.3 /K.sub.1 for mending and spreading, which is in the order of the maximum possible, the steepness of the characteristic line is approved by the characteristic line is bi-stable or when using liquid crystal material with the ratio of the elastic constants K.sub.3 /K.sub.
    Type: Grant
    Filed: May 15, 1989
    Date of Patent: February 23, 1993
    Assignee: Merck Patent Gesellschaft mit beschraenkter Haftung
    Inventors: Gunter Baur, Bernhard Scheuble, Waltraud Fehrenbach
  • Patent number: 4886344
    Abstract: A suitable choice of the liquid crystal parameters K.sub.3 /K.sub.1 and .DELTA.E/E.sub.1 makes it possible in electrooptical display elements to obtain both a minimum dependence on the angle of observation and, simultaneously, a steep electro-optical characteristic when operated in the first transmission minimum.
    Type: Grant
    Filed: August 19, 1988
    Date of Patent: December 12, 1989
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Bernhard Scheuble, Gunter Baur, Waltraud Fehrenbach
  • Patent number: 4799774
    Abstract: By suitable choice of the liquid crystal parameters K.sub.3 /K.sub.1 and K.sub.3 /K.sub.2, it becomes possible to achieve a steep electrooptical characteristic line and a maximum contrast with minimum dependence on the viewing angle in electrooptical display elements with a twist angle with a value between 150.degree. and 250.degree..
    Type: Grant
    Filed: November 17, 1987
    Date of Patent: January 24, 1989
    Assignee: Merck Patent Gesellschaft Mit Beschrankter Haftung
    Inventors: Guter Baur, Bernhard Scheuble, Waltraud Fehrenbach