Patents by Inventor Lewis D. Eigen

Lewis D. Eigen 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).

  • Constructed response method with invisible answer indicator to prevent cheating
    Patent number: 3990156
    Abstract: A device for teaching includes a work sheet having a number of sets of response regions. Each response region is comprised of at least one answer area and at least one confirmation area. Invisibly printed answers are generally provided within the confirmation areas. By omitting the answers from selected confirmation areas, it is possible to determine whether a student is making his response in the answer area before seeking a confirmation of the correctness of this answer by making the answer in the confirmation area visible.
    Type: Grant
    Filed: February 18, 1975
    Date of Patent: November 9, 1976
    Assignee: Meredith Corporation
    Inventor: Lewis D. Eigen