Patents by Inventor Venkatramani S. Iyer

Venkatramani S. Iyer 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).

  • Impregnation of plastic substrates with photochromic additives
    Patent number: 5851585
    Abstract: The present invention relates to new methods of impregnating plastic substrates with photochromic additives. By impregnating the plastic substrate in multiple impregnation steps under varying conditions, the concentration profile of two or more photochromic additive within the plastic substrate can be independently controlled. Methods are also provided for the distribution of a photochromic additive in a high boiling solvent and for increasing the glass transition temperature of a partially cured polymeric resin.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: December 22, 1998
    Assignee: Innotech, Inc.
    Inventors: Amitava Gupta, Ronald D. Blum, Venkatramani S. Iyer
  • Impregnation of plastic substrates with photochromic additives
    Patent number: 5789015
    Abstract: The present invention relates to new methods of impregnating plastic substrates with photochromic additives. By impregnating the plastic substrate in multiple impregnation steps under varying conditions, the concentration profile of two or more photochromic additive within the plastic substrate can be independently controlled. Methods are also provided for the distribution of a photochromic additive in a high boiling solvent and for increasing the glass transition temperature of a partially cured polymeric resin.
    Type: Grant
    Filed: June 26, 1996
    Date of Patent: August 4, 1998
    Assignee: Innotech, Inc.
    Inventors: Amitava Gupta, Ronald D. Blum, Venkatramani S. Iyer
  • Composite lenses
    Patent number: 5702819
    Abstract: A method for making improved optical quality lenses is described which includes arranging a mold having a molding surface, a curable optical quality resin composition, and a plastic lens preform of optical quality material such that the resin composition is disposed between, and in contact with, the plastic lens preform and the mold; upon curing, the resin composition forms a cured plastic attached portion that is bonded to the plastic lens preform. The resin composition and plastic lens preform are selected such that the attached portion has a higher scratch resistance, a lower chromatic aberration, and/or a higher ease of edging than the lens preform.
    Type: Grant
    Filed: May 17, 1996
    Date of Patent: December 30, 1997
    Assignee: Innotech, Inc.
    Inventors: Amitava Gupta, Ronald D. Blum, Venkatramani S. Iyer, Paul J. Nagg
  • Composite lenses
    Patent number: 5512371
    Abstract: A method for making improved optical quality lenses is described. The method includes arranging a mold having a molding surface, a curable optical quality resin composition, and a plastic lens preform of optical quality material such that the resin composition is disposed between, and in contact with, the plastic lens preform and the mold. Upon curing, the resin composition forms a cured plastic attached portion that is bonded to the plastic lens preform. The resin composition and plastic lens preform are selected such that the attached portion has a higher scratch resistance, a lower chromatic aberration, and/or a higher ease of edging than the lens preform.
    Type: Grant
    Filed: March 18, 1994
    Date of Patent: April 30, 1996
    Assignee: Innotech, Inc.
    Inventors: Amitava Gupta, Ronald D. Blum, Venkatramani S. Iyer, Paul J. Nagg