Patents by Inventor Keisuke Koga

Keisuke Koga 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: 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: 20060066216
    Abstract: There is provided a field emission display that can achieve high brightness without increasing the anode voltage, and can realize high resolution by suppressing the occurrence of inter-pixel crosstalk resulting from light excited from the phosphor layers. A field emission display is constructed by a field emission electron source disposed in a vacuum container and a phosphor screen that is disposed in the vacuum container so as to be opposite to the field emission electron source and that has a plurality of recessed portions on its surface opposing to the field emission electron source, with phosphor layers being formed in the recessed portions An image is displayed by causing the phosphor layers to emit light by collision of electrons emitted from the field emission electron source.
    Type: Application
    Filed: September 23, 2005
    Publication date: March 30, 2006
    Applicant: Matsushita Toshiba Picture Display Co., Ltd.
    Inventors: Keisuke Koga, Akinori Shiota, Makoto Yamamoto
  • Publication number: 20060066198
    Abstract: An electron source apparatus includes a plurality of electron emission portions arranged in a matrix on a Si substrate, and a plurality of emitter lines and a plurality of gate lines that are orthogonal to each other, and each of the plurality of electron emission portions being controlled by signals from the plurality of emitter lines and the plurality of gate lines to perform an independent electron emission operation.
    Type: Application
    Filed: September 19, 2005
    Publication date: March 30, 2006
    Applicant: Matsushita Toshiba Picture Display Co., Ltd.
    Inventors: Makoto Yamamoto, Keisuke Koga, Akinori Shiota
  • Patent number: 6940218
    Abstract: A field-emission electron source element includes a cathode substrate, an insulating layer that is formed on the cathode substrate and has an opening, a lead electrode formed on the insulating layer, and an emitter formed in the opening. A surface layer of an electron emitting region of the emitter is doped with at least one reducing element selected from the group consisting of hydrogen and carbon monoxide. Further, an image display apparatus including the above-mentioned field-emission electron source element is provided. This makes it possible to obtain not only a stable field-emission electron source element that does not cause a current drop even after a high current density operation for a long time but also a high-performance image display apparatus that can maintain a stable display performance over a long period of time.
    Type: Grant
    Filed: August 8, 2003
    Date of Patent: September 6, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keisuke Koga, Toru Kawase, Kenichi Honda, Tetsuya Norikane
  • Patent number: 6914373
    Abstract: A cathode ray tube according to the present invention include a cold cathode electron gun, the cold cathode electron gun including a cold cathode array for emitting electrons through field emission, a gate electrode for controlling the field emission, a first selective electrode provided around the cold cathode array and the gate electrode, and a second selective electrode opposing the first selective electrode, and the second selective electrode is adapted to have a lower potential than the gate electrode and the first selective electrode. In accordance with this configuration, the divergence of electron beams emitted from any positions in the cold cathode array can be converged uniformly upon removing electron beams emitted at a great emission angle. This allows the electron beams thereafter to be made narrower by an electrostatic lens. As a result, the present invention can provide a cathode ray tube capable of forming a high-resolution image.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: July 5, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takashi Itoh, Masahide Yamauchi, Koji Fujii, Keisuke Koga, Toru Kawase
  • 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
  • Patent number: 6818915
    Abstract: The field emission type electron source device of the present invention includes: a field emission electron source portion including an extraction electrode provided on a p-type silicon substrate via an insulating film and having an opening portion at a position corresponding to a region where a cathode is provided; and a cathode portion provided on the p-type silicon substrate and at a position corresponding to the opening portion of the extraction portion; and an n-channel field effect transistor portion provided on the p-type silicon substrate, corresponding to the field emission electron source portion. The field emission electron source portion is provided in a drain region of the field effect transistor portion. A control voltage is applied to a gate electrode of the field effect transistor portion to control a field emission current from the field emission electron source portion. The drain region includes at least two wells having different impurity concentrations.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: November 16, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Keisuke Koga
  • Patent number: 6812654
    Abstract: The object of the present invention is to provide a field emission device that emits an electron beam bundle whose spot profile on a display screen has as little distortion as possible, and that maintains a stable electron emission property regardless of the length of a driving time, a CRT apparatus equipped with such field emission device, and a production method of such CRT apparatus. The field emission device (10) has, on a surface of a substrate (11), a plurality of cathode electrodes (12) parallel to each other, an insulation layer (13), and a plurality of extraction electrodes (14) parallel to each other, in the stated order, the cathode electrodes (12) and the extraction electrodes (14) being orthogonal to each other and so yielding a plurality of crossover regions. At the crossover regions, electron emission zones (15) each made up of four emitters (16) are formed.
    Type: Grant
    Filed: September 2, 2003
    Date of Patent: November 2, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keisuke Koga, Toru Kawase
  • 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
  • Patent number: 6794822
    Abstract: A field emission electron source includes: a field emission array portion composed of an insulation layer with a plurality of apertures, which is formed on a substrate, an extraction electrode formed on the insulation layer, and a plurality of cathodes formed respectively on the substrate in the plurality of apertures; a cathode base for fixing the field emission array portion; and an electron lens portion composed of a plurality of electrode members having a function of accelerating and converging an electron beam emitted from the field emission array portion. An emission axis of the electron beam emitted from the field emission array portion has a predetermined angle with respect to an optical axis of the electron lens portion. Thus, the field emission array portion can be protected from impact caused by ions generated in the electron lens portion, thereby improving the life of a field emission electron source.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: September 21, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keisuke Koga, Toru Kawase, Masahide Yamauchi, Koji Fujii, Takashi Itoh
  • Publication number: 20040051461
    Abstract: The object of the present invention is to provide a field emission device that emits an electron beam bundle whose spot profile on a display screen has as little distortion as possible, and that maintains a stable electron emission property regardless of the length of a driving time, a CRT apparatus equipped with such field emission device, and a production method of such CRT apparatus.
    Type: Application
    Filed: September 2, 2003
    Publication date: March 18, 2004
    Inventors: Keisuke Koga, Toru Kawase
  • Publication number: 20040032194
    Abstract: A field-emission electron source element includes a cathode substrate, an insulating layer that is formed on the cathode substrate and has an opening, a lead electrode formed on the insulating layer, and an emitter formed in the opening. A surface layer of an electron emitting region of the emitter is doped with at least one reducing element selected from the group consisting of hydrogen and carbon monoxide. Further, an image display apparatus including the above-mentioned field-emission electron source element is provided. This makes it possible to obtain not only a stable field-emission electron source element that does not cause a current drop even after a high current density operation for a long time but also a high-performance image display apparatus that can maintain a stable display performance over a long period of time.
    Type: Application
    Filed: August 8, 2003
    Publication date: February 19, 2004
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keisuke Koga, Toru Kawase, Kenichi Honda, Tetsuya Norikane
  • Patent number: 6692327
    Abstract: An electron emission element includes a substrate, a cathode electrode formed on the substrate, an anode electrode disposed so as to be opposed to the cathode electrode, an electron emission member disposed on the cathode electrode, a control electrode disposed between the cathode electrode and the anode electrode, and an insulating layer. The electron emission member includes a first member having a hole and a second member filling the hole, wherein the second member is more likely to emit electrons than the first member.
    Type: Grant
    Filed: January 11, 2000
    Date of Patent: February 17, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masahiro Deguchi, Makoto Kitabatake, Kanji Imai, Tomohiro Sekiguchi, Hideo Kurokawa, Keisuke Koga, Tetsuya Shiratori, Toru Kawase
  • Publication number: 20040004588
    Abstract: The object of the present invention is to provide a driving method and a driving apparatus for a field emission device that controls emission current with stability regardless of how long the device is driven. The field emission device driving method and driving apparatus of the present invention set the actual emission current at a reference level by adjusting the amount of current which is supplied to the emitter to a reference level. The amount of current supplied to the emitter is adjusted to the reference level by increasing the driving voltage in response to driving time elapsing in a state in which the electron emission performance is sustained above the reference level.
    Type: Application
    Filed: April 9, 2003
    Publication date: January 8, 2004
    Inventors: Toru Kawase, Keisuke Koga
  • Patent number: 6661166
    Abstract: A cathode includes emitter tips provided on a substrate, a gate electrode with an electric field formed between the gate electrode and the emitter tips, and terminals and leads for supplying voltages to the emitter tips and the gate electrode, respectively. A shield electrode further is provided between the cathode and a control electrode, and the shield electrode has a cylindrical projecting portion projecting toward the cathode, through which electron beams pass. The disturbance of an electric field by the leads influences the electron beams; however, this can be prevented by the projecting portion. Because of this, even if the size of the cathode is reduced, the distortion of an electron beam spot on a phosphor screen can be reduced. As a result, a cathode-ray tube with high resolution can be provided at a low cost.
    Type: Grant
    Filed: June 4, 2002
    Date of Patent: December 9, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masahide Yamauchi, Takashi Itoh, Koji Fujii, Keisuke Koga, Toru Kawase
  • Publication number: 20030151367
    Abstract: A method is applied for operating a cold cathode having at least one electron emission portion and a control electrode for controlling an emission of electrons, in which an electron beam is extracted out of the cold cathode by applying operating voltages to the electron emission portion and the control electrode, respectively. At least one auxiliary electron emission portion is provided other than the electron emission portion positioned at an operating position for emitting electrons. In order to replace the electron emission portion to be operated, the electron emission portions are moved so that the auxiliary electron emission portion is positioned at the operating position.
    Type: Application
    Filed: February 13, 2003
    Publication date: August 14, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toru Kawase, Keisuke Koga
  • Publication number: 20030107312
    Abstract: A field emission device having cold cathode devices including an emitter and a lead electrode, and the field emission device is provided with the plural kinds of cold cathode device groups classified based on the emission property of the cold cathode device. This field emission device has a member for allowing the cold cathode device group to perform emission by successively changing the cold cathode device group that mainly performs emission based on the difference in the emission property. Thus, it is possible to maintain the emission current at a predetermined necessary value or more and to realize the long lifetime of the field emission device.
    Type: Application
    Filed: December 10, 2002
    Publication date: June 12, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toru Kawase, Keisuke Koga
  • Publication number: 20030098410
    Abstract: A field emission electron source includes: a field emission array portion composed of an insulation layer with a plurality of apertures, which is formed on a substrate, an extraction electrode formed on the insulation layer, and a plurality of cathodes formed respectively on the substrate in the plurality of apertures; a cathode base for fixing the field emission array portion; and an electron lens portion composed of a plurality of electrode members having a function of accelerating and converging an electron beam emitted from the field emission array portion. An emission axis of the electron beam emitted from the field emission array portion has a predetermined angle with respect to an optical axis of the electron lens portion. Thus, the field emission array portion can be protected from impact caused by ions generated in the electron lens portion, thereby improving the life of a field emission electron source.
    Type: Application
    Filed: November 12, 2002
    Publication date: May 29, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd
    Inventors: Keisuke Koga, Toru Kawase, Masahide Yamauchi, Koji Fujii, Takashi Itoh
  • Publication number: 20030006687
    Abstract: A cathode ray tube according to the present invention include a cold cathode electron gun, the cold cathode electron gun including a cold cathode array for emitting electrons through field emission, a gate electrode for controlling the field emission, a first selective electrode provided around the cold cathode array and the gate electrode, and a second selective electrode opposing the first selective electrode, and the second selective electrode is adapted to have a lower potential than the gate electrode and the first selective electrode. In accordance with this configuration, the divergence of electron beams emitted from any positions in the cold cathode array can be converged uniformly upon removing electron beams emitted at a great emission angle. This allows the electron beams thereafter to be made narrower by an electrostatic lens. As a result, the present invention can provide a cathode ray tube capable of forming a high-resolution image.
    Type: Application
    Filed: June 27, 2002
    Publication date: January 9, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takashi Itoh, Masahide Yamauchi, Koji Fujii, Keisuke Koga, Toru Kawase
  • Publication number: 20020190631
    Abstract: A cathode includes emitter tips provided on a substrate, a gate electrode with an electric field formed between the gate electrode and the emitter tips, and terminals and leads for supplying voltages to the emitter tips and the gate electrode, respectively. A shield electrode further is provided between the cathode and a control electrode, and the shield electrode has a cylindrical projecting portion projecting toward the cathode, through which electron beams pass. The disturbance of an electric field by the leads influences the electron beams; however, this can be prevented by the projecting portion. Because of this, even if the size of the cathode is reduced, the distortion of an electron beam spot on a phosphor screen can be reduced. As a result, a cathode-ray tube with high resolution can be provided at a low cost.
    Type: Application
    Filed: June 4, 2002
    Publication date: December 19, 2002
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masahide Yamauchi, Takashi Itoh, Koji Fujii, Keisuke Koga, Toru Kawase