Patents by Inventor Johannes L. A. M. Heldens

Johannes L. A. M. Heldens 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).

  • Display device
    Patent number: 4286266
    Abstract: In a liquid crystal display device which upon controlling with direct voltage shows a memory effect that can be erased by alternating voltage, the written area can expand beyond the edge of the electrode so that edge zones can no longer be erased readily. This disadvantage is avoided by covering the edges of the electrodes with an insulating layer.
    Type: Grant
    Filed: December 13, 1978
    Date of Patent: August 25, 1981
    Assignee: U.S. Philips Corporation
    Inventors: Maarten De Zwart, Johannes L. A. M. Heldens