Patents by Inventor Karin Else Bredfeldt

Karin Else Bredfeldt 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).

  • Electrochromic display devices comprising thienylidene pyrazoline compounds
    Patent number: 4090782
    Abstract: This invention relates to a reversible display device based upon the electrochromic properties of certain thienylidene pyrazoline compounds when used in conjunction with a complementary redox material.
    Type: Grant
    Filed: May 31, 1977
    Date of Patent: May 23, 1978
    Assignee: International Business Machines Corporation
    Inventors: Karin Else Bredfeldt, Robert Bruce Champ, Karl John Fowler