Patents by Inventor David L. Hofeldt

David L. Hofeldt 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).

  • Publication number: 20100231897
    Abstract: Systems and methods for calibrating a web inspection system.
    Type: Application
    Filed: May 25, 2010
    Publication date: September 16, 2010
    Inventors: David L. HOFELDT, Derek H. Justice, John A. Ramthun, Catherine P. Tarnowski, Wenyuan Xu
  • Patent number: 7773226
    Abstract: Systems and methods for calibrating a web inspection system.
    Type: Grant
    Filed: June 5, 2008
    Date of Patent: August 10, 2010
    Assignee: 3M Innovative Properties Company
    Inventors: David L. Hofeldt, Derek H. Justice, John A. Ramthun, Catherine P. Tarnowski, Wenyuan Xu
  • Publication number: 20100188651
    Abstract: An apparatus that can measure both haze and clarity on a web moving at conventional manufacturing speeds. The apparatus uses an integrating sphere and a novel mirror arrangement. With this arrangement, the invention can utilize a calibration curve created using known samples over the range of measurement desired to convert in real time, and the response of two photo detectors that measure the wide and low angle scattering signals, to deduce the desired optical property values. This approach significantly increases the speed and response of sensor and enables either on-line single point or full web scanning for uniformity measurement and control.
    Type: Application
    Filed: July 1, 2008
    Publication date: July 29, 2010
    Inventors: Gregory D. Kostuch, David L. Hofeldt
  • Publication number: 20090303484
    Abstract: Systems and methods for calibrating a web inspection system.
    Type: Application
    Filed: June 5, 2008
    Publication date: December 10, 2009
    Inventors: David L. HOFELDT, Derek H. Justice, John A. Ramthun, Catherine P. Tarnowski, Wenyuan Xu
  • Patent number: 7202490
    Abstract: A radiation modifying apparatus comprises a plurality of solid state radiation sources to generate radiation that modifies a first material such as by curing or creating alignment through polarization. The solid state radiation sources can be disposed in an array pattern. Optical concentrators, arranged in a corresponding array pattern, receive radiation from corresponding solid state radiation sources. The concentrated radiation is received by a plurality of optical waveguides, also arranged in a corresponding array pattern. Each optical waveguide includes a first end to receive the radiation and a second end to output the radiation. The radiation modifying apparatus can be utilized for continuous substrate, sheet, piece part, spot curing, and/or 3D radiation-cure processes.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: April 10, 2007
    Assignee: 3M Innovative Properties Company
    Inventors: Francis M. Aguirre, Peter T. Benson, Michele A. Craton, David L. Hofeldt, Jack W. Lai, David L. Phillips
  • Patent number: 7189983
    Abstract: A radiation modifying apparatus comprises a plurality of solid state radiation sources to generate radiation that modifies a first material such as by curing or creating alignment through polarization. The solid state radiation sources can be disposed in an array pattern. Optical concentrators, arranged in a corresponding array pattern, receive radiation from corresponding solid state radiation sources. The concentrated radiation is received by a plurality of optical waveguides, also arranged in a corresponding array pattern. Each optical waveguide includes a first end to receive the radiation and a second end to output the radiation. The radiation modifying apparatus can be utilized for continuous substrate, sheet, piece part, spot curing, and/or 3D radiation-cure processes.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: March 13, 2007
    Assignee: 3M Innovative Properties Company
    Inventors: Francis M. Aguirre, Peter T. Benson, Michele A. Craton, Gordon D. Henson, David L. Hofeldt, Jack W. Lai, Michael A. Meis, David L. Phillips