Patents by Inventor Douglas D. Castle

Douglas D. Castle 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: D325196
    Type: Grant
    Filed: March 8, 1991
    Date of Patent: April 7, 1992
    Assignee: Digital Biometrics, Inc.
    Inventors: Bruce N. Stanger, Glenn M. Fishbine, Douglas D. Castle
  • Patent number: D346158
    Type: Grant
    Filed: March 25, 1991
    Date of Patent: April 19, 1994
    Assignee: Digital Biometrics, Inc.
    Inventors: Bruce N. Stanger, Glenn M. Fishbine, Douglas D. Castle