Patents by Inventor Hemasiri K. Vithana

Hemasiri K. Vithana 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).

  • Four domain pixel for liquid crystalline light modulating device
    Patent number: 6141074
    Abstract: A liquid crystalline light modulating pixel includes first and second cell wall structures and nematic liquid crystal disposed therebetween. The first and second cell wall structures cooperate with the liquid crystal to form four liquid crystal domains within the pixel. The liquid crystal in each of the domains exhibits a twisted nematic liquid crystal structure and the orientation of the liquid crystal director of the liquid crystal adjacent one of the cell wall structures in at least two domains is different.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: October 31, 2000
    Assignee: Kent State University
    Inventors: Philip J. Bos, Hemasiri K. Vithana, David L. Johnson, Jianmin Chen
  • Optically active diffractive device
    Patent number: 5638201
    Abstract: A liquid crystalline diffractive light valve for use in a diffractive projection system. The liquid crystal cell includes substrates treated to provide alternating stripes which cooperate with the liquid crystal to form liquid crystal domains extending across the thickness of the cell that will produce a 180.degree. phase difference in light emerging from adjacent domains, irrespective of the polarization of incident light.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: June 10, 1997
    Inventors: Philip J. Bos, David L. Johnson, Jianmin Chen, Hemasiri K. Vithana, William E. Glenn, Carvel E. Holton, Brett E. Smith