Patents by Inventor Masayoshi Nagao

Masayoshi Nagao 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: 11887802
    Abstract: Provided in the present disclosure is an electron emitting element 10 including a laminated structure in which a first electrode 1, an electron accelerating layer 6 made of an insulation film, a second electrode 3, and a cover film 7 are laminated in that order, in which the second electrode is an electrode which transmits electrons and emits electrons from a surface thereof, and the cover film is a film which transmits electrons, is a protective film made of a material different from that of the second electrode, and constitutes an electron emission surface 5.
    Type: Grant
    Filed: March 16, 2021
    Date of Patent: January 30, 2024
    Inventors: Katsuhisa Murakami, Masayoshi Nagao
  • Publication number: 20230298847
    Abstract: An electron gun for an electron microscope or similar device includes a field emitter cathode having a field emitter protrusion extending from the output surface of a monocrystalline silicon substrate, and electrodes configured to enhance the emission of electrons from a tip portion of the field emitter protrusion to generate a primary electron beam. A contiguous TiN layer is disposed directly on at least the tip portion of the field emitter protrusion using a process that minimizes oxidation and defects in the TiN layer.
    Type: Application
    Filed: March 16, 2023
    Publication date: September 21, 2023
    Inventors: Yung-Ho Alex Chuang, Yinying Xiao-Li, Edgardo García Berríos, John Fielden, Lavinia Ghirardini, Masayoshi Nagao
  • Publication number: 20230134647
    Abstract: Provided in the present disclosure is an electron emitting element 10 including a laminated structure in which a first electrode 1, an electron accelerating layer 6 made of an insulation film, a second electrode 3, and a cover film 7 are laminated in that order, in which the second electrode is an electrode which transmits electrons and emits electrons from a surface thereof, and the cover film is a film which transmits electrons, is a protective film made of a material different from that of the second electrode, and constitutes an electron emission surface 5.
    Type: Application
    Filed: March 16, 2021
    Publication date: May 4, 2023
    Inventors: Katsuhisa MURAKAMI, Masayoshi NAGAO
  • Publication number: 20220216026
    Abstract: An electron emission device having a narrow electron energy range and excellent electron emitting efficiency, and an electron microscope using the electron emission device. An electron emission device having a laminated structure in which a first electrode, an electron accelerating layer made of an insulating film, and a second electrode are laminated in this order, in which the second electrode through which electrons transmit and from whose surface electrons emit, and the energy width of the emitted electrons is 100 meV or more and 600 meV or less. For example, graphene having one or more layers and 20 layers or less can be used as the second electrode, and hexagonal boron nitride can be used as the insulating film.
    Type: Application
    Filed: March 23, 2020
    Publication date: July 7, 2022
    Inventors: Katsuhisa MURAKAMI, Masayoshi NAGAO
  • Patent number: 10943760
    Abstract: An electron gun for an electron microscope or similar device includes a field emitter cathode having a field emitter protrusion extending from the output surface of a monocrystalline silicon substrate, and electrodes configured to enhance the emission of electrons from a tip portion of the field emitter protrusion to generate a primary electron beam. A thin, contiguous SiC layer is disposed directly on at least the tip portion of the field emitter protrusion using a process that minimizes oxidation and defects in the SiC layer. Optional gate layers may be placed at, slightly lower than or slightly higher than the height of the field emitter tip portion to achieve high emission current and fast and accurate control of the primary emission beam. The field emitter can be p-type doped and configured to operate in a reverse bias mode, or the field emitter can be n-type doped.
    Type: Grant
    Filed: September 11, 2019
    Date of Patent: March 9, 2021
    Assignees: KLA Corporation, National Institute Of Advanced Industrial Science and Technology
    Inventors: Yung-Ho Alex Chuang, Yinying Xiao-Li, Edgardo Garcia Berrios, John Fielden, Masayoshi Nagao
  • Publication number: 20200118783
    Abstract: An electron gun for an electron microscope or similar device includes a field emitter cathode having a field emitter protrusion extending from the output surface of a monocrystalline silicon substrate, and electrodes configured to enhance the emission of electrons from a tip portion of the field emitter protrusion to generate a primary electron beam. A thin, contiguous SiC layer is disposed directly on at least the tip portion of the field emitter protrusion using a process that minimizes oxidation and defects in the SiC layer. Optional gate layers may be placed at, slightly lower than or slightly higher than the height of the field emitter tip portion to achieve high emission current and fast and accurate control of the primary emission beam. The field emitter can be p-type doped and configured to operate in a reverse bias mode, or the field emitter can be n-type doped.
    Type: Application
    Filed: September 11, 2019
    Publication date: April 16, 2020
    Inventors: Yung-Ho Alex Chuang, Yinying Xiao-Li, Edgar Garcia Berrios, John Fielden, Masayoshi Nagao
  • Patent number: 9024544
    Abstract: In a field emission device, the fundamental cause of spherical aberration in an emitted electron beam trajectory is eliminated or mitigated. An aberration suppressor electrode 31 is provided at a lower vertical position than an extraction gate electrode 13 so its opening inner peripheral edge 31e faces a position near an emitter tip 11tp. The vertical position of the opening inner peripheral edge 31e of the aberration suppressor electrode 31 is made lower than the vertical position of the emitter tip 11tp. An aberration suppressing voltage Vsp is applied to the aberration suppressor electrode 31 that is a lower voltage than the potential of the emitter 11 and controls equipotential lines near the emitter tip 11tp to make them parallel.
    Type: Grant
    Filed: November 10, 2010
    Date of Patent: May 5, 2015
    Assignee: National University Corporation Sizuoka University
    Inventors: Masayoshi Nagao, Tomoya Yoshida, Yoichiro Neo
  • Publication number: 20120229051
    Abstract: In a field emission device, the fundamental cause of spherical aberration in an emitted electron beam trajectory is eliminated or mitigated. An aberration suppressor electrode 31 is provided at a lower vertical position than an extraction gate electrode 13 so its opening inner peripheral edge 31e faces a position near an emitter tip 11tp. The vertical position of the opening inner peripheral edge 31e of the aberration suppressor electrode 31 is made lower than the vertical position of the emitter tip 11tp. An aberration suppressing voltage Vsp is applied to the aberration suppressor electrode 31 that is a lower voltage than the potential of the emitter 11 and controls equipotential lines near the emitter tip 11tp to make them parallel.
    Type: Application
    Filed: November 10, 2010
    Publication date: September 13, 2012
    Applicant: NATIONAL UNIVERSITY CORPORATION SIZUOKA UNIVERSITY
    Inventors: Masayoshi Nagao, Tomoya Yoshida, Yoichiro Neo
  • Patent number: 7588475
    Abstract: A stable field-emission electron source that does not suffer from a current drop even after a high-current density operation for a long time is provided. The field-emission electron source includes: a substrate; an insulating layer that is formed on the substrate and that has a plurality of openings; cathodes arranged at the respective openings in order to emit electron beams; a lead electrode formed on the insulating layer in order to control emission of electrons from the respective cathodes; and a surface-modifying layer formed on the surface of each of the cathodes emitting electrons, comprising a chemical bond between a cathode material composing the cathodes and a material different from the cathode material.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: September 15, 2009
    Assignee: Panasonic Corporation
    Inventors: Keisuke Koga, Makoto Yamamoto, Akinori Shiota, Seigo Kanemaru, Masayoshi Nagao
  • Patent number: 7375400
    Abstract: An image display device is provided in which the overall brightness of an image can be varied without adversely affecting hue and contrast. The image display device includes emitters 16 connected to a cathode electrode 15, a gate electrode 13, an anode electrode 3, transistors Tr1 and Tr2, and a capacitor 12. A voltage applied to the capacitor 12 is varied to display an image. A constant voltage is applied to the gate electrode 13 to change a time ratio Du. Thus, the overall brightness of an image can be adjusted.
    Type: Grant
    Filed: November 7, 2006
    Date of Patent: May 20, 2008
    Assignees: Futaba Corporation, National Institute of Advanced Industrial Science and Technology
    Inventors: Shigeo Itoh, Masateru Taniguchi, Masayoshi Nagao
  • Publication number: 20070184747
    Abstract: A stable field-emission electron source that does not suffer from a current drop even after a high-current density operation for a long time is provided. The field-emission electron source includes: a substrate; an insulating layer that is formed on the substrate and that has a plurality of openings; cathodes arranged at the respective openings in order to emit electron beams; a lead electrode formed on the insulating layer in order to control emission of electrons from the respective cathodes; and a surface-modifying layer formed on the surface of each of the cathodes emitting electrons, comprising a chemical bond between a cathode material composing the cathodes and a material different from the cathode material.
    Type: Application
    Filed: March 29, 2007
    Publication date: August 9, 2007
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keisuke Koga, Makoto Yamamoto, Akinori Shiota, Seigo Kanemaru, Masayoshi Nagao
  • Publication number: 20070103085
    Abstract: An image display device is provided in which the overall brightness of an image can be varied without adversely affecting hue and contrast. The image display device includes emitters 16 connected to a cathode electrode 15, a gate electrode 13, an anode electrode 3, transistors Tr1 and Tr2, and a capacitor 12. A voltage applied to the capacitor 12 is varied to display an image. A constant voltage is applied to the gate electrode 13 to change a time ratio Du. Thus, the overall brightness of an image can be adjusted.
    Type: Application
    Filed: November 7, 2006
    Publication date: May 10, 2007
    Inventors: Shigeo Itoh, Masateru Taniguchi, Masayoshi Nagao
  • Patent number: 7215072
    Abstract: A stable field-emission electron source that does not suffer from a current drop even after a high-current density operation for a long time is provided. The field-emission electron source includes: a substrate; an insulating layer that is formed on the substrate and that has a plurality of openings; cathodes arranged at the respective openings in order to emit electron beams; a lead electrode formed on the insulating layer in order to control emission of electrons from the respective cathodes; and a surface-modifying layer formed on the surface of each of the cathodes emitting electrons, comprising a chemical bond between a cathode material composing the cathodes and a material different from the cathode material.
    Type: Grant
    Filed: March 23, 2004
    Date of Patent: May 8, 2007
    Assignees: Matsushita Electric Industrial Co., Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Keisuke Koga, Makoto Yamamoto, Akinori Shiota, Seigo Kanemaru, Masayoshi Nagao
  • Patent number: 7112920
    Abstract: A field emission electron source capable of achieving large current density is provided at low cost with good productivity. An insulating layer is formed on a substrate and has one or more openings; and an extraction electrode is formed on the insulating layer. In one or more of the openings, a plurality of emitters, each of which emits an electron by an electric field from the extraction electrode, are formed on the substrate.
    Type: Grant
    Filed: April 20, 2004
    Date of Patent: September 26, 2006
    Assignee: National instutute of advanced industrial science and technology
    Inventors: Makoto Yamamoto, Keisuke Koga, Akinori Shiota, Seigo Kanemaru, Masayoshi Nagao
  • Publication number: 20050001536
    Abstract: A field emission electron source capable of achieving large current density is provided at low cost with good productivity. An insulating layer is formed on a substrate and has one or more openings; and an extraction electrode is formed on the insulating layer. In one or more of the openings, a plurality of emitters, each of which emits an electron by an electric field from the extraction electrode, are formed on the substrate.
    Type: Application
    Filed: April 20, 2004
    Publication date: January 6, 2005
    Applicants: Matsushita Electric Industrial Co., Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Makoto Yamamoto, Keisuke Koga, Akinori Shiota, Seigo Kanemaru, Masayoshi Nagao
  • Publication number: 20040189176
    Abstract: A stable field-emission electron source that does not suffer from a current drop even after a high-current density operation for a long time is provided. The field-emission electron source includes: a substrate; an insulating layer that is formed on the substrate and that has a plurality of openings; cathodes arranged at the respective openings in order to emit electron beams; a lead electrode formed on the insulating layer in order to control emission of electrons from the respective cathodes; and a surface-modifying layer formed on the surface of each of the cathodes emitting electrons, comprising a chemical bond between a cathode material composing the cathodes and a material different from the cathode material.
    Type: Application
    Filed: March 23, 2004
    Publication date: September 30, 2004
    Applicants: Matsushita Electric Industrial Co., Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Keisuke Koga, Makoto Yamamoto, Akinori Shiota, Seigo Kanemaru, Masayoshi Nagao