Patents by Inventor Stephen H. Pollack

Stephen H. Pollack 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: 4823062
    Abstract: A two-dimensional linear motor is provided with sensors respectively capable of detecting only the x and y grid lines arranged in a platen traversed by the linear motor. These signals are accumulated and their counts are compared against the respective x and y distances the linear motor is to be moved in order to move the linear motor to the precise position desired and/or to verify that the desired movement has been accomplished. Differentiation of the mutually orthogonal sets of grid lines is accomplished by providing the grid lines with reflective surfaces which have different reflectivity characteristics or alternatively have a different reflectivity characteristics at with appropriate evaluation devices such as filters or threshold circuits which differentiate between either different wavelengths or different reflectivity characterisitics.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: April 18, 1989
    Assignee: Megamation, Incorporated
    Inventors: Brian D. Hoffman, Stephen H. Pollack