Patents by Inventor Tit-Keung Lau

Tit-Keung Lau 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: 20080041716
    Abstract: Described herein are photomask blanks and photomasks prepared therefrom, methods for producing the photomask blanks and apparatus used in such methods. In one aspect, there is described methods for preparing photomask blanks having layers with a compositional gradient, i.e., a varying composition through the thickness of the layer. In other aspects, either in conjunction with the above aspects or independently, methods and apparatus are provided which allow more efficient use of a cluster tool for preparing the photomask blanks and performing quality control on them. The inventions find applicability, for example, in preparing binary photomask blanks and phase shift photomask blanks.
    Type: Application
    Filed: August 18, 2006
    Publication date: February 21, 2008
    Inventors: Hakki Ufuk Alpay, Devi Koty, Michael Patrick Goudy, Tit Keung Lau
  • Patent number: 5798181
    Abstract: The present invention is an improved release coating for use on a variety of elastomeric structures, such as printer rollers and belts. The coating of the present invention is a thin expanded polytetrafluoroethylene skin that has a porous surface attached to a substratum and an impermeable surface exposed as the contact surface. This use of dual surfaces on a single thin coating provides both an excellent bond to substratum materials, such as a silicone elastomer layer, as well as being highly wear resistant and resistant to chemical attack.
    Type: Grant
    Filed: October 4, 1994
    Date of Patent: August 25, 1998
    Assignee: W. L. Gore & Associates, Inc.
    Inventors: Alex Ray Hobson, Robert L. Sassa, Steven H. Speck, Tit-Keung Lau
  • Patent number: 5779795
    Abstract: This invention provides a liquid metering and surface coating device which can satisfactorily perform the operation of applying a release liquid to at least the surface of toner image fixation rolls in plain paper copying, with exceptional accuracy, uniformity, and durability. The device comprises a porous support layer adhered to a metal shaft. The porous support layer is comprised of an open-celled thermosetting polymer foam internally reinforced to obtain the strength, resilience, and heat resistance needed for high durability in use as part of a hot toner image fixation mechanism in a PPC machine. The porous support is comprised of materials having high compatibility with and wettability by the liquids to be distributed and having high liquid holding capacity so as to provide smooth continuous liquid delivery.
    Type: Grant
    Filed: August 4, 1995
    Date of Patent: July 14, 1998
    Assignee: W. L. Gore & Associates, Inc.
    Inventors: Richard Andrew Bucher, Robert L. Sassa, Tit-Keung Lau
  • Patent number: 5744241
    Abstract: The present invention is an improved release coating for use on a variety of surfaces, such as printer rollers and belts. The coating of the present invention is an thin expanded polytetrafluoroethylene skin that has a porous surface attached to a substratum and an impermeable surface exposed as the contact surface. This use of dual surfaces on a single thin coating provides both an excellent bond to substratum materials, such as a silicone elastomer layer, as well as being highly wear resistant and resistant to chemical attack.
    Type: Grant
    Filed: December 4, 1995
    Date of Patent: April 28, 1998
    Assignee: W. L. Gore & Associates, Inc.
    Inventors: Alex Ray Hobson, Robert L. Sassa, Steven H. Speck, Tit-Keung Lau
  • Patent number: 4744847
    Abstract: A process is disclosed for separating a series of substrate elements laminated with a supported photosensitive composition whereby the support is weakened by heating in a line pattern along abutting edges of the substrate prior to pulling the laminated substrates apart.
    Type: Grant
    Filed: January 29, 1986
    Date of Patent: May 17, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Tit-Keung Lau