Patents by Inventor Eric Rothfjell

Eric Rothfjell 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).

  • Method of signature verification and device for carrying out the method
    Patent number: 4856077
    Abstract: A method and a device for signature verification, where an electric pulse train individual for every person in question is caused to be generated in that said person is allowed to move a pen comprising at its nib a light-emitting member and a light-sensitive member over a background, whereby an electric pulse train is caused to be emitted from the light-sensitive member in response to patterns on said background, and where said pulse train generated at a certain occasion is caused by means of a computer, processor or corresponding device to be compared with pulse trains generated earlier.
    Type: Grant
    Filed: January 14, 1988
    Date of Patent: August 8, 1989
    Inventor: Eric Rothfjell
  • Method of deriving characteristic contours from a colored picture
    Patent number: 4055833
    Abstract: A method of deriving characteristic curves from a colored photograph of an object, which comprises making an image comprising only one of the basic colors of the colored photograph, the contrast of said image being enhanced, so that only the areas of the object which are most strongly colored in said color are reproduced.
    Type: Grant
    Filed: June 10, 1975
    Date of Patent: October 25, 1977
    Inventor: Rolf Eric Rothfjell