Patents by Inventor Joseph K. Madathil

Joseph K. Madathil 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: 6603150
    Abstract: An organic light-emitting device includes a substrate, an anode, a cathode, disposed between the anode and the cathode is an electroluminescent medium including, in sequence: a hole-transporting layer; an interface layer; a light-emitting layer; and an electron-transporting layer. The interface layer comprises a compound having an ionization potential greater than that of the organic compound of the hole-transporting layer, and an energy bandgap equal to or greater than that of the organic compound of the light-emitting layer. Wherein the thickness of the interface layer is in the range of 0.1 nm˜5 nm. The interface layer provides more balanced carrier recombination in the light-emitting layer, and achieves higher luminance efficiency.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: August 5, 2003
    Assignee: Eastman Kodak Company
    Inventors: Liang-Sheng Liao, Joseph K. Madathil, Kevin P. Klubek, Ching W. Tang
  • Publication number: 20030129447
    Abstract: An OLED device, including a substrate, an anode formed of a conductive material over the substrate, an emissive layer having an electroluminescent material provided over the anode, a buffer layer provided over the emissive layer and containing a halide of a heavy alkaline metal, and a sputtered layer of a metal or metal alloy selected to function with the buffer layer to inject electrons.
    Type: Application
    Filed: September 19, 2001
    Publication date: July 10, 2003
    Applicant: Eastman Kodak Company
    Inventors: Joseph K. Madathil, Pranab K. Raychaudhuri, Ching W. Tang
  • Patent number: 6579629
    Abstract: An OLED device including a substrate, an anode formed of a conductive material over the substrate, and an emissive layer having an electroluminescent material provided over the anode. The OLED device also includes a buffer structure having at least two layers, a first buffer layer provided over the emissive layer and containing an alkaline halide and a second buffer layer provided over the first buffer layer and containing phthalocyanine, and a sputtered cathode layer having an alloy containing an alkaline metal provided over the buffer structure.
    Type: Grant
    Filed: August 11, 2000
    Date of Patent: June 17, 2003
    Assignee: Eastman Kodak Company
    Inventors: Pranab K. Raychaudhuri, Ching W. Tang, Joseph K. Madathil
  • Patent number: 6558820
    Abstract: An OLED device including a substrate, an anode formed of a conductive material over the substrate, and an emissive layer having an electroluminescent material provided over the anode. The OLED device also includes either an ultrathin cathode over the emissive layer, a thin interlayer over the ultrathin cathode and a reflecting layer over the thin interlayer, or the thin interlayer over the emissive layer and a reflecting layer containing an electron-injecting dopant over the thin interlayer.
    Type: Grant
    Filed: May 10, 2001
    Date of Patent: May 6, 2003
    Assignee: Eastman Kodak Company
    Inventors: Pranab K. Raychaudhuri, Joseph K. Madathil
  • Publication number: 20030075720
    Abstract: An organic light-emitting device includes a substrate, an anode, a cathode, disposed between the anode and the cathode is an electroluminescent medium including, in sequence: a hole-transporting layer; an interface layer; a light-emitting layer; and an electron-transporting layer. The interface layer comprises a compound having an ionization potential greater than that of the organic compound of the hole-transporting layer, and an energy bandgap equal to or greater than that of the organic compound of the light-emitting layer. Wherein the thickness of the interface layer is in the range of 0.1 nm˜5 nm. The interface layer provides more balanced carrier recombination in the light-emitting layer, and achieves higher luminance efficiency.
    Type: Application
    Filed: September 28, 2001
    Publication date: April 24, 2003
    Applicant: Eastman Kodak Company
    Inventors: Liang-Sheng Liao, Joseph K. Madathil, Kevin P. Klubek, Ching W. Tang
  • Patent number: 6551725
    Abstract: An OLED device, including a substrate, an anode formed of a conductive material over the substrate, an emissive layer having an electroluminescent material provided over the anode layer, a buffer structure including at least two layers, a first buffer layer provided over the electron-transport layer and containing an alkaline halide and a second buffer layer provided over the first buffer layer and containing a metal or metal alloy and having a work function of between 2.0 to 4.0 eV; and a sputtered layer of a metal or metal alloy provided over the buffer structure.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: April 22, 2003
    Assignee: Eastman Kodak Company
    Inventors: Pranab K. Raychaudhuri, Joseph K. Madathil
  • Publication number: 20030035978
    Abstract: An OLED device including a substrate, an anode formed of a conductive material over the substrate, and an emissive layer having an electroluminescent material provided over the anode. The OLED device also includes either an ultrathin cathode over the emissive layer, a thin interlayer over the ultrathin cathode and a reflecting layer over the thin interlayer, or the thin interlayer over the emissive layer and a reflecting layer containing an electron-injecting dopant over the thin interlayer.
    Type: Application
    Filed: May 10, 2001
    Publication date: February 20, 2003
    Applicant: Eastman Kodak Company
    Inventors: Pranab K. Raychaudhuri, Joseph K. Madathil
  • Publication number: 20020185969
    Abstract: An OLED device, including a substrate, an anode formed of a conductive material over the substrate, an emissive layer having an electroluminescent material provided over the anode layer, a buffer structure including at least two layers, a first buffer layer provided over the electron-transport layer and containing an alkaline halide and a second buffer layer provided over the first buffer layer and containing a metal or metal alloy and having a work function of between 2.0 to 4.0 V; and a sputtered layer of a metal or metal alloy provided over the buffer structure.
    Type: Application
    Filed: February 28, 2001
    Publication date: December 12, 2002
    Applicant: Eastman Kodak Company
    Inventors: Pranab K. Raychaudhuri, Joseph K. Madathil
  • Patent number: 6429451
    Abstract: An organic light-emitting device capable of reducing ambient-light reflection from a cathode includes a light-transmissive substrate, a light-transmissive anode, an organic hole-transporting layer, and an organic electron transporting layer. A reflection-reducing structure disposed between the electron-transporting layer and a light-reflective cathode is capable of providing electron injection into the electron-transporting layer and of substantially reducing reflection of ambient-light entering the device.
    Type: Grant
    Filed: May 24, 2000
    Date of Patent: August 6, 2002
    Assignee: Eastman Kodak Company
    Inventors: Liang-Sun Hung, Joseph K. Madathil
  • Patent number: 6278236
    Abstract: An organic electroluminescent (EL) device having a layered structure, including an anode; an organic hole-transport layer in contact with the anode; an organic emitting layer having one surface thereof in contact with the hole-transport layer; an organic electron-transport layer in contact with a second surface of the emitting layer; an electron-injecting layer in contact with the electron-transport layer; and a cathode in contact with the electron-injecting layer, wherein the electron-injecting layer includes aluminum and at least one alkali halide or at least one alkaline earth halide.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: August 21, 2001
    Assignee: Eastman Kodak Company
    Inventors: Joseph K. Madathil, Max G. Mason, Ching W. Tang
  • Patent number: 6208075
    Abstract: A fluorocarbon based conductive polymer and method of making such polymer are disclosed. The conductive polymer is advantageously used in electroluminescent devices.
    Type: Grant
    Filed: November 5, 1998
    Date of Patent: March 27, 2001
    Assignee: Eastman Kodak Company
    Inventors: Liang-Sun Hung, Longru Zheng, Joseph K. Madathil
  • Patent number: 6140763
    Abstract: An organic light-emitting device including a substrate, an anode disposed over the substrate, an organic light-emitting structure disposed over the anode, a cathode buffer layer disposed over the organic light-emitting structure and formed of a material selected to permit high energy deposition of a cathode, and a cathode disposed over the cathode buffer layer and being provided with an electron-injecting dopant which diffuses across the buffer layer to provide an interfacial electron-injecting layer at the interface between the organic light-emitting structure and the cathode buffer layer.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: October 31, 2000
    Assignee: Eastman Kodak Company
    Inventors: Liang S. Hung, Joseph K. Madathil, Ching W. Tang
  • Patent number: 6137223
    Abstract: An organic light-emitting device including a substrate; an anode disposed over the substrate; an organic light-emitting structure disposed over the anode; a cathode buffer layer disposed over the organic light-emitting structure and formed of a material selected to permit high energy deposition of a cathode; a cathode disposed over the cathode buffer layer; and a dopant layer disposed between the cathode buffer layer and the cathode and being provided with an electron-injecting dopant which diffuses across the buffer layer to provide an interfacial electron-injecting layer at the interface between the light-emitting structure and the cathode buffer layer.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: October 24, 2000
    Assignee: Eastman Kodak Company
    Inventors: Liang S. Hung, Joseph K. Madathil
  • Patent number: 6069442
    Abstract: An organic EL device, includes an anode, an anode, an organic hole transporting layer over the anode, an organic luminescent layer on the organic hole transporting layer, an inorganic electron transporting layer over the organic luminescent layer, and a cathode on the electron transporting layer.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: May 30, 2000
    Assignee: Eastman Kodak Company
    Inventors: Liang-Sun Hung, Joseph K. Madathil
  • Patent number: 5904961
    Abstract: A method of depositing organic layers on a substrate in organic light emitting devices is disclosed. The method uses a donor support which is coated with a transferable coating of an organic donor material selected as one of a plurality of organic materials useful in an organic light emitting device. The donor coating is positioned in transferable relationship with the substrate in an environment of reduced pressure. The donor support is heated to cause the transferable coating of organic donor material to transfer to a position on or over the substrate and to form a layer of the organic material on the substrate.
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: May 18, 1999
    Assignee: Eastman Kodak Company
    Inventors: Ching W. Tang, Joseph K. Madathil, Dustin L. Comfort