Patents by Inventor Victor S. Chang

Victor S. Chang 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: 6583930
    Abstract: A birefringent interference polarizer which may be fabricated from readily available materials using established coextrusion techniques is provided. The polarizer has a level of light absorption near zero and can be fabricated to polarize and reflect light of specific wavelengths while transmitting light of other wavelengths. The polarizer includes multiple alternating oriented layers of at least first and second polymeric materials having respective nonzero stress optical coefficients which are sufficiently different to produce a refractive index mismatch between the first and second polymeric materials in a first plane which is different from the refractive index mismatch between the first and second polymeric materials in a second plane normal to the first plane. The refractive index mismatch in the first plane is preferably at least 0.03.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: June 24, 2003
    Assignee: 3M Innovative Properties
    Inventors: Walter J. Schrenk, Victor S. Chang, John A. Wheatley
  • Patent number: 5872653
    Abstract: A birefringent interference polarizer which may be fabricated from readily available materials using established coextrusion techniques is provided. The polarizer has a level of light absorption near zero and can be fabricated to polarize and reflect light of specific wavelengths while transmitting light of other wavelengths. The polarizer includes multiple alternating oriented layers of at least first and second polymeric materials having respective nonzero stress optical coefficients which are sufficiently different to produce a refractive index mismatch between the first and second polymeric materials in a first plane which is different from the refractive index mismatch between the first and second polymeric materials in a second plane normal to the first plane. The refractive index mismatch in the first plane is preferably at least 0.03.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: February 16, 1999
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Walter J. Schrenk, John A. Wheatley, Victor S. Chang
  • Patent number: 5612820
    Abstract: A birefringent interference polarizer which may be fabricated from readily available materials using established coextrusion techniques is provided. The polarizer has a level of light absorption near zero and can be fabricated to polarize and reflect light of specific wavelengths while transmitting light of other wavelengths. The polarizer includes multiple alternating oriented layers of at least first and second polymeric materials having respective nonzero stress optical coefficients which are sufficiently different to produce a refractive index mismatch between the first and second polymeric materials in a first plane which is different from the refractive index mismatch between the first and second polymeric materials in a second plane normal to the first plane. The refractive index mismatch in the first plane is preferably at least 0.03.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: March 18, 1997
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, Victor S. Chang, John A. Wheatley
  • Patent number: 5486949
    Abstract: A birefringent interference polarizer which may be fabricated from readily available materials using established coextrusion techniques is provided. The polarizer has a level of light absorption near zero and can be fabricated to polarize and reflect light of specific wavelengths while transmitting light of other wavelengths. The polarizer includes multiple alternating oriented layers of at least first and second polymeric materials having respective nonzero stress optical coefficients which are sufficiently different to produce a refractive index mismatch between the first and second polymeric materials in a first plane which is different from the refractive index mismatch between the first and second polymeric materials in a second plane normal to the first plane. The refractive index mismatch in the first plane is preferably at least 0.03.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: January 23, 1996
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, John A. Wheatley, Victor S. Chang
  • Patent number: 5389463
    Abstract: A battery separator composed of a microporous sheet product having first and second major surfaces and a thickness of less than about 50 mils, formed from a uniform mixture of a halogenated polyolefin polymer and a filler or a halogenated polyolefin polymer and surfactant/filler agent, said sheet product having a fibrous sheet embedded within said mixture and between the first and second major surfaces. The porosity of the sheet product is at least about 50 volume percent composed of pores such that the average pore diameter increases from each major surface towards the interior of the sheet product's thickness.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: February 14, 1995
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Victor S. Chang, Richard T. Giovannoni, Richard C. Hartwig, Joseph T. Lundquist, Christian B. Lundsager, Marc E. Parham, Anthony J. Laccetti
  • Patent number: 5362581
    Abstract: A battery separator composed of a microporous sheet product having first and second major surfaces and a thickness of less than about 50 mils, formed from a uniform mixture of a polycarbonate polymer and a filler or a polycarbonate and a structure enhancing agent, said sheet product having a porous sheet embedded within said mixture and between the first and second major surfaces. The porosity of the sheet product is at least about 50 volume percent composed of pores such that the nominal pore diameter increases incrementally from each major surface towards the interior central portion of the sheet product's thickness.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: November 8, 1994
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Victor S. Chang, Richard C. Hartwig, Joseph T. Lundquist, Marc E. Parham, Anthony J. Laccetti
  • Patent number: 5362582
    Abstract: A battery separator composed of a microporous sheet product having first and second major surfaces and a thickness of less than about 50 mils, formed from a uniform mixture of a polymer and a filler or a polymer and a structure enhancing agent and having a porous sheet embedded between the first and second major surface. The porosity of the sheet product is at least about 50 volume percent having a pore distribution such that the nominal pore diameter increases from each major surface towards the interior central portion of the sheet product's thickness.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: November 8, 1994
    Assignee: W.R. Grace & Co.-Conn.
    Inventors: Victor S. Chang, Richard C. Hartwig, Joseph T. Lundquist, Marc E. Parham, James K. Kung, James A. Avtges, Anthony J. Laccetti