Patents by Inventor Cornelia Pithart

Cornelia Pithart 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: 7067179
    Abstract: A novel compound represented by the general formula (I), and a nematic liquid crystal composition incorporating the same. A compound represented by the general formula (I) can be produced industrially extremely easily, as shown in the examples, displays superior compatibility with current general purpose host liquid crystals as a nematic phase, and also shows little crystal precipitation at low temperatures. Moreover, by addition of a small amount of such a compound to a host liquid crystal, the liquid crystal temperature range at low temperatures can be effectively widened without any significant worsening of the various characteristics of the liquid crystal material. Consequently, a compound of the present invention is an extremely useful liquid crystal material which is suitable for various liquid crystal display elements which require a broad operating temperature range.
    Type: Grant
    Filed: September 10, 1999
    Date of Patent: June 27, 2006
    Assignee: Dainippon Ink and Chemicals, Inc.
    Inventors: Shinji Ogawa, Tatsuo Kawara, Sadao Takehara, Hiroyuki Ohnishi, Kiyofumi Takeuchi, Haruyoshi Takatsu, Gerwald Grahe, Rainer Bruno Frings, Christine Fugger, Cornelia Pithart
  • Patent number: 6913797
    Abstract: The present invention discloses a decahydronaphthalene derivative represented by general formula (I): a liquid crystal composition in which it is contained, and a liquid crystal device in which it is used. The novel decahydronaphthalene derivative of the present invention can be produced industrially extremely easily as shown in the examples, and by adding a small amount to a base liquid crystal, it is possible to have effects that expand the nematic phase temperature range, thereby improving its various characteristics as a nematic liquid crystal. Moreover, the novel decahydronaphthalene derivative of the present invention also has superior co-solubility with base liquid crystals generally used at present. Thus, it is suitable for various types of liquid crystal devices requiring a wide operating temperature range, and is extremely useful as a liquid crystal material.
    Type: Grant
    Filed: August 23, 1999
    Date of Patent: July 5, 2005
    Assignee: Dainippon Ink and Chemicals, Inc.
    Inventors: Shinji Ogawa, Hiroyuki Ohnishi, Yutaka Nagashima, Sadao Takehara, Makoto Negishi, Haruyoshi Takatsu, Gerwald Grahe, Rainer Bruno Frings, Christine Fugger, Cornelia Pithart
  • Patent number: 6746728
    Abstract: A tetrahydronaphthalene derivative represented by the general formula (I) and a liquid crystal composition containing the same. A compound represented by the general formula (I) shows superior liquid crystallinity and co-solubility with conventional liquid crystal compounds and compositions. Furthermore, addition of such a compound enables the threshold voltage to be significantly reduced with almost no deleterious effect on the responsiveness. In addition, a compound of the present invention can also be easily produced industrially, is colorless, and is chemically stable. Consequently, liquid crystal compositions containing such a compound are extremely useful as liquid crystals, and are particularly suitable for liquid crystal displays requiring a wide operating temperature range, low voltage driving and a high response speed.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: June 8, 2004
    Assignee: Dainippon Ink and Chemicals, Inc.
    Inventors: Tetsuo Kusumoto, Yoshitaka Saito, Makoto Negishi, Yutaka Nagashima, Sadao Takehara, Haruyoshi Takatsu, Gerwald Grahe, Rainer Bruno Frings, Cornelia Pithart