Patents by Inventor Joseph W. Doane

Joseph W. Doane 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: 7170481
    Abstract: The present invention relates to a display film that may be transferred by lamination or otherwise onto a substrate. The display film is formed of a stack of layers that can include different types, arrangements, and functionality within the stack depending upon factors including the characteristics of the substrate (e.g., upper or lower, transparent or opaque, substrates) and addressing of the display (e.g., active or passive matrix, electrical or optical addressing). The layers of the stacked display film include one or more electrode layers and one or more liquid crystal layers and, in addition, may include various combinations of an adhesive layer, preparation layer, casting layer, light absorbing layer, insulation layers, and protective layers. The liquid crystal layer can include cholesteric or other liquid crystal material. The liquid crystal layer can be a dispersion of liquid crystal in a polymer matrix formed by a variety of techniques.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: January 30, 2007
    Assignee: Kent Displays Incorporated
    Inventors: Joseph W. Doane, Asad A. Khan, Irina Shiyanovskaya, Tod Schneider, Oleg Pishnyak, Seth E. Green, Forrest N. Nicholson, Liang-Chy Chien
  • Patent number: 6830789
    Abstract: A unique class of chiral additive materials is disclosed for use in cholesteric displays that possess a helical twist power substantially independent of temperature. The additives have a solubility and a helical twist power large enough to be used as a single chiral component with little dilution of the physical properties of the nematic liquid crystal host mixture. The chiral additives may be used in combination with non-chiral additives to provide a helical twisting power substantially independent of temperature suitable for cholesteric displays.
    Type: Grant
    Filed: September 24, 2001
    Date of Patent: December 14, 2004
    Assignees: Kent Displays, Inc., Kent State University
    Inventors: Joseph W. Doane, Asad A. Khan, Alexander J. Seed
  • Publication number: 20020187281
    Abstract: A unique class of chiral additive materials is disclosed for use in cholesteric displays that possess a helical twist power substantially independent of temperature. The additives have a solubility and a helical twist power large enough to be used as a single chiral component with little dilution of the physical properties of the nematic liquid crystal host mixture. The chiral additives may be used in combination with non-chiral additives to provide a helical twisting power substantially independent of temperature suitable for cholesteric displays.
    Type: Application
    Filed: September 24, 2001
    Publication date: December 12, 2002
    Inventors: Joseph W. Doane, Asad A. Khan, Alexander J. Seed
  • Patent number: 5504600
    Abstract: An oriented ferroelectric liquid crystal in the chiral smectic C phase with the smectic planes normal to bounding plates of a cell is interspersed with polymer which stabilizes and freezes the arrangement of the liquid crystal. The polymer which stabilizes the liquid crystal is formed by a method which includes introducing a mixture of a monomer and a ferroelectric liquid crystal between cell walls when the liquid crystal is in the isotropic phase, cooling the liquid crystal to a chiral nematic or smectic phase, and polymerizing the monomer. The cooling of the mixture can be done in the presence of a magnetic or electric field.
    Type: Grant
    Filed: April 11, 1995
    Date of Patent: April 2, 1996
    Assignee: Kent State University
    Inventors: Janez Pirs, Robert Blinc, Slobodan Zumer, Igor Musevic, Bojan Marin, Silva Pirs, Joseph W. Doane
  • Patent number: 5434685
    Abstract: An oriented ferroelectric liquid crystal in the chiral smectic C phase with the smectic planes normal to bounding plates of a cell is interspersed with polymer which stabilizes and freezes the arrangement of the liquid crystal.
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: July 18, 1995
    Assignee: Kent State University
    Inventors: Janez Pirs, Robert Blinc, Slobodan Zumer, Igor Musevic, Bojan Marin, Silva Pirs, Joseph W. Doane
  • Patent number: 5240636
    Abstract: A haze-free light modulating polymer dispersed liquid crystal (PDLC) material is disclosed which comprises a polymer which is birefringent and possesses anisotropic optical properties similar to those of the dispersed liquid crystal such that the PDLC material in its transparent state exhibits a refractive index that is matched for all directions of incident light providing for an optically clear, scatter-free film for all angles of view. Electrooptic light shutters are possible from this material which are transparent in the field OFF-state and opaque in the field ON-state or vice versa, depending upon the liquid crystal phase structure and configuration of the light shutter device.
    Type: Grant
    Filed: March 30, 1992
    Date of Patent: August 31, 1993
    Assignee: Kent State University
    Inventors: Joseph W. Doane, John L. West
  • Patent number: 4994204
    Abstract: A haze-free light modulating polymer dispersed liquid crystal (PDLC) material is disclosed which comprises a polymer matrix which is birefringent and possesses anisotropic optical properties similar to those of the dispersed liquid crystal microdroplets such that the PDLC material in its transparent state exhibits a refractive index that is matched for all directions of incident light providing for an optically clear, scatter-free film for all angles of view. Electrooptic light shutters are possible from this material which are transparent in the field OFF-state and opaque in the field ON-state or vice versa, depending upon the microdroplet structure and configuration of the light shutter device.
    Type: Grant
    Filed: March 20, 1989
    Date of Patent: February 19, 1991
    Assignee: Kent State University
    Inventors: Joseph W. Doane, John L. West
  • Patent number: 4688900
    Abstract: A light modulating material consisting of droplets of liquid crystal in a clear or light transmitting, flexible plastic sheet or film, such as a cured epoxy. The light modulating material is prepared by dissolving liquid crystal in an uncured resin and then curing the resin so that droplets of liquid crystal spontaneously form and are uniformly dispersed throughout the sheet or film. The new material shows a reversible, high contrast optical response from an opaque scattering mode to a clear light transmission mode when either the temperature of the material is changed to transform the liquid crystal into the isotropic phase or an electric field is applied across the material. The material is optically responsive to strain, whereby under tension it acts to polarize incident light. Curing the material in the presence of an applied field also causes it to act as an electrically addressable polarizer.
    Type: Grant
    Filed: September 17, 1985
    Date of Patent: August 25, 1987
    Assignee: Kent State University
    Inventors: Joseph W. Doane, Giuseppe Chidichimo, Nuno A. P. Vaz
  • Patent number: 4685771
    Abstract: The invention provides a new liquid crystal display material prepared by the phase separation of a homogeneous solution of liquid crystal and thermoplastic resin to create in situ microdroplets of liquid crystal within a set transparent resin matrix. The new display material is characterized by ease of fabrication and the ability to be reworked by simple heating and cooling of the thermoplastic resin containing microdroplets of liquid crystal. It has been discovered that such a material fabricated from a thermoplastic resin and a liquid crystal having a liquid crystalline phase to isotropic phase transition temperature above the softening temperature of the resin exhibits a reversible field-independent memory.
    Type: Grant
    Filed: May 22, 1986
    Date of Patent: August 11, 1987
    Inventors: John L. West, Joseph W. Doane, Slobodan Zumer
  • Patent number: 4673255
    Abstract: The invention provides a method of controlling the rate of growth of liquid crystal microdroplets formed in situ by the phase separation of a homogeneous solution of liquid crystal and polymer. Temperature, relative concentration and choice of materials determine the microdroplet growth rate and resultant microdroplet size and density. Controlling growth rate allows for fabrication of liquid crystal display devices with optimized display characteristics and response times.
    Type: Grant
    Filed: June 27, 1986
    Date of Patent: June 16, 1987
    Inventors: John West, Attilio Golemme, Joseph W. Doane