Patents by Inventor Helwig Schaefer

Helwig Schaefer 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).

  • Liquid crystal cell having an insulating layer of a silicon oxide base
    Patent number: 4201453
    Abstract: A liquid crystal cell having a pair of spaced carrier plates with inner surfaces forming a cavity for receiving a layer of liquid crystal material, each of said inner surfaces being provided with a conductive coating and at least one of the carrier plates having its conductive coating covered with an insulated layer of silicon oxide base characterized by the insulating layer containing an additive selected from a group consisting of boron oxide, tin oxide, titanium oxide and mixtures thereof so that the insulating layer causes homeotropic orientation of the molecules of the liquid crystal layer.
    Type: Grant
    Filed: May 18, 1978
    Date of Patent: May 6, 1980
    Assignee: Siemens Aktiengesellschaft
    Inventors: Manfred Kobale, Hans Pink, Helwig Schaefer