Patents by Inventor Man C. Tam

Man C. Tam 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: 4883731
    Abstract: An imaging system in which an imaging member comprising a substrate and an electrically insulating softenable layer on the substrate, the softenable layer comprising migration marking material locked at least at or near the surface of the softenable layer spaced from the substrate, and a charge transport material in the softenable layer is imaged by electrostatically charging the member, exposing the member to activating radiation in an imagewise pattern, and decreasing the resistance to migration of marking material in the softenable layer sufficiently to allow the migration marking material struck by activating radiation to substantially migrate in depth towards the substrate in image configuration.
    Type: Grant
    Filed: January 4, 1988
    Date of Patent: November 28, 1989
    Assignee: Xerox Corporation
    Inventors: Man C. Tam, Arnold L. Pundsack
  • Patent number: 4880715
    Abstract: An imaging system in which an imaging member comprising a substrate and an electrically insulating softenable layer on the substrate, the softenable layer comprising migration marking material located at least at or near the surface of the softenable layer spaced from the substrate, and a charge transport material in the softenable layer is imaged by eletrostatically charging the member, exposing the member to activating radiation in an imagewise pattern, decreasing the resistance to migration of marking material in the softenable layer sufficiently to allow the migration marking material struck by said activating radiation to retain a slight net charge which allows only slight agglomeration, slight coalescence, slight migration in depth of marking material towards said substrate or combination thereof in image configuration during a further decreasing of the resistance to migration towards the substrate in image configuration, and further decreasing the resistance to migration of marking material in the soft
    Type: Grant
    Filed: January 4, 1988
    Date of Patent: November 14, 1989
    Assignee: Xerox Corporation
    Inventors: Man C. Tam, Robert W. Gundlach, Arnold L. Pundsack
  • Patent number: 4853307
    Abstract: An imaging system including a migration imaging member comprising a substrate and an electrically insulating softening layer adjacent the substrate, the softenable layer comprising a fracturable layer of electrically photosensitive migration marking material located substantially at or near the surface of the softenable layer spaced from the substrate, and a copolymer of styrene and ethyl acrylate in at least one layer adjacent the substrate, the copolymer comprising between about 40 and about 80 mole percent styrene, between about 20 and about 60 mole percent ethyl acrylate, the copolymer having a M.sub.n between about 4,000 and about 35,000, a M.sub.w between about 10,000 and about 80,000, a T.sub.g between about 30.degree. C. and about 75.degree. C., and a melt viscosity between about 1.times.10.sup.2 poise and about 1.times.10.sup.6 poise at 115.degree. C.
    Type: Grant
    Filed: January 4, 1988
    Date of Patent: August 1, 1989
    Assignee: Xerox Corporation
    Inventors: Man C. Tam, Steven Bloembergen, Gregory J. Kovacs, Carol A. Jennings, Rafik O. Loutfy, Sandra J. Gardner, Michael G. Taylor
  • Patent number: 4536457
    Abstract: An imaging method comprising providing a migration imaging member comprising a substrate and an electrically insulating softenable layer on the substrate, the softenable layer comprising migration marking material located at least at or near the surface of the softenable layer spaced from the substrate and a charge transport material in the softenable layer, electrostatically charging the member, exposing the member to activating radiation in an imagewise pattern, decreasing the resistance to migration of marking material in the softenable layer sufficiently to allow slight migration in depth of marking material towards the substrate in image configuration, and further decreasing the resistance to migration of marking material in the softenable layer sufficiently to allow nonmigrated marking material to agglomerate.
    Type: Grant
    Filed: January 3, 1984
    Date of Patent: August 20, 1985
    Assignee: Xerox Corporation
    Inventor: Man C. Tam
  • Patent number: 4496642
    Abstract: An imaging member comprising a substrate, an electrically insulating swellable, softenable layer on the substrate, the softenable layer having particulate migration marking material located at least at or near the surface of the softenable layer spaced from the substrate, and a protective overcoating comprising a film-forming resin, a portion of which extends beneath the surface of the softenable layer. This migration imaging member may be prepared with the aid of a material which swells at least the surface of the softenable layer to allow the film-forming resin to penetrate beneath the surface of the softenable layer.
    Type: Grant
    Filed: May 12, 1983
    Date of Patent: January 29, 1985
    Assignee: Xerox Corporation
    Inventors: Man C. Tam, Gregory J. Kovacs
  • Patent number: 4246448
    Abstract: An electromechanical electret transducer suitable for push-pull operation includes multiple vibratory diaphragms acoustically coupled to each other to increase the output sound pressure. Since the diaphragms physically shield the stationary electrets, the adverse environmental effects on the charge stabilities of the electrets are minimized.
    Type: Grant
    Filed: August 3, 1977
    Date of Patent: January 20, 1981
    Assignee: Uniroyal Ltd.
    Inventors: Man C. Tam, Loh-Yi Chang