Patents by Inventor Seiichi Sakawa

Seiichi Sakawa 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).

  • Publication number: 20220190403
    Abstract: A heat insulating material composition, including: a composite in which cellulose microfibrils enclose wet silica particles having an average particle diameter of 1 ?m or more and 50 ?m or less.
    Type: Application
    Filed: April 6, 2020
    Publication date: June 16, 2022
    Applicant: DENKA COMPANY LIMITED
    Inventors: Kohei MIZUTA, Kazuto TABARA, Seiichi SAKAWA
  • Publication number: 20170233647
    Abstract: A wavelength converter is provided with a light-transmitting substrate and with a thin film that is formed on a surface of the light-transmitting substrate and that contains a phosphor. A sintered body that constitutes the light-transmitting substrate has an average particle size of 5-40 ?m. The light-transmitting substrate contains at least 10-500 ppm by mass of MgO. The principal component of the phosphor is an ?-sialon that is indicated by the general formula (Ca?,Eu?) (Si,Al)12(O,N)16 (provided that 1.5<?+?<2.2, 0<?<0.2, and O/N?0.04).
    Type: Application
    Filed: April 20, 2017
    Publication date: August 17, 2017
    Applicants: DENKA Company Limited, NGK Insulators, Ltd.
    Inventors: Seiichi SAKAWA, Kenji MONDEN, Takeshi ASAMI, Tsuneaki OHASHI, Kazuyoshi SHIBATA
  • Patent number: 7969080
    Abstract: The present invention provides an electron source that can produce a stable electron beam even if an apparatus employing the electron source receives vibration from the outside. An electron source comprising an insulator, a pair of conductive terminals attached to the insulator, a filament tensed between the pair of conductive terminals, a rod-shaped cathode having a sharp end portion performing as an electron emitting portion and joined with the filament, wherein the cathode has another end portion different from the electron emitting portion, fixed to the insulator. It is preferred that said another end portion of the cathode other than the electron emitting portion, is fixed to the insulator via a metal pin brazed with the insulator.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: June 28, 2011
    Assignee: Denki Kagaku Kogyo Kabushiki Kaisha
    Inventors: Yoshinori Terui, Seiichi Sakawa
  • Patent number: 7919750
    Abstract: An electron gun includes an electron source configured to emit electrons. The electron source includes an electron emission region configured to emit the electrons and an electron emission restrictive region configured to restrict emission of the electrons. The electron emission restrictive region is located on a side surface of the electron source except an electron emission surface on a tip of the electron source and is covered with a different material from the electron source. The electron gun emits thermal field-emitted electrons by applying an electric field to the tip while maintaining a sufficiently low temperature to avoid sublimation of a material of the electron source. The material of the electron source may be lanthanum hexaboride (LaB6) or cerium hexaboride (CeB6). The electron emission restrictive region may be covered with carbon.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: April 5, 2011
    Assignees: Advantest Corporation, Denki Kagaku Kogyo Kabushiki Kaisha
    Inventors: Hiroshi Yasuda, Takeshi Haraguchi, Yoshihisa Ooae, Takamasa Satoh, Yoshinori Terui, Seiichi Sakawa, Ryozo Nonogaki
  • Patent number: 7722425
    Abstract: An electron source excellent in the uniformity in current emission distribution is provided certainly and at a low cost. A process for producing an electron source having an electron emitting portion at one end of a rod, which comprises a step of forming the electron emitting portion by machining, and a step of removing a damaged layer at the surface of the formed electron emitting portion by chemical polishing or electrolytic polishing.
    Type: Grant
    Filed: January 13, 2006
    Date of Patent: May 25, 2010
    Assignee: Denki Kagaku Kogyo Kabushiki Kaisha
    Inventors: Seiichi Sakawa, Yoshinori Terui
  • Publication number: 20100026160
    Abstract: An electron source showing little surplus current even at a time of high angular intensity operation is provided. An electron source comprising an electron emitting portion, a suppressor electrode and an extractor electrode, wherein the electron emitting portion is present at a leading edge of an end of a single crystal rod having a shape comprising a first truncated cone portion or a cone portion, and a second truncated cone portion continuing therefrom. It is preferably the electron source, wherein the single crystal rod has an oxide of a metal element selected from the group consisting of Ca, Sr, Ba, Sc, Y, La, Ti, Zr, Hf and lanthanoide elements as a diffusion source, and the single crystal rod is made of tungsten or molybden of <100> orientation.
    Type: Application
    Filed: September 26, 2007
    Publication date: February 4, 2010
    Applicant: Denki Kagaku Kogyo Kabushiki Kaisha
    Inventors: Yoshinori Terui, Fumihiro Nakahara, Seiichi Sakawa
  • Publication number: 20100019649
    Abstract: The present invention provides an electron source that can produce a stable electron beam even if an apparatus employing the electron source receives vibration from the outside. An electron source comprising an insulator, a pair of conductive terminals attached to the insulator, a filament tensed between the pair of conductive terminals, a rod-shaped cathode having a sharp end portion performing as an electron emitting portion and joined with the filament, wherein the cathode has another end portion different from the electron emitting portion, fixed to the insulator. It is preferred that said another end portion of the cathode other than the electron emitting portion, is fixed to the insulator via a metal pin brazed with the insulator.
    Type: Application
    Filed: August 31, 2007
    Publication date: January 28, 2010
    Applicant: Denki Kagaku Kogyo Kabushiki Kaisha 1-1, Nihonbashi-Muromachi 2-chome
    Inventors: Yoshinori Terui, Seiichi Sakawa
  • Publication number: 20090023355
    Abstract: An electron source excellent in the uniformity in current emission distribution is provided certainly and at a low cost A process for producing an electron source having an electron emitting portion at one end of a rod which comprises a step of forming the electron emitting portion by machining, and a step of removing a damaged layer at the surface of the formed electron emitting portion by chemical polishing or electrolytic polishing.
    Type: Application
    Filed: January 13, 2006
    Publication date: January 22, 2009
    Applicant: Denki Kagaku Kogyo Kabushiki Kaisha
    Inventors: Seiichi Sakawa, Yoshinori Terui
  • Publication number: 20080315089
    Abstract: An electron gun includes an electron source configured to emit electrons. The electron source includes an electron emission region configured to emit the electrons and an electron emission restrictive region configured to restrict emission of the electrons. The electron emission restrictive region is located on a side surface of the electron source except an electron emission surface on a tip of the electron source and is covered with a different material from the electron source. The electron gun emits thermal field-emitted electrons by applying an electric field to the tip while maintaining a sufficiently low temperature to avoid sublimation of a material of the electron source. The material of the electron source may be lanthanum hexaboride (LaB6) or cerium hexaboride (CeB6). The electron emission restrictive region may be covered with carbon.
    Type: Application
    Filed: May 7, 2008
    Publication date: December 25, 2008
    Inventors: Hiroshi Yasuda, Takeshi Haraguchi, Yoshihisa Ooae, Takamasa Satoh, Yoshinori Terui, Seiichi Sakawa, Ryozo Nonogaki
  • Publication number: 20060145585
    Abstract: To provide an electron source which is suitable for an electron beam lithography machine, an Auger electron spectroscope or the like and provides a small total emission current even in a high angular intensity operation. An electron gun provided with a cathode which comprises a single crystal needle of tungsten or molybdenum and a coating layer consisting of oxygen and at least one metal element selected from the group consisting of Group 2A, Group 3A and Group 4A, formed on its surface, characterized in that an apex of the cathode as a truncated cone shape, and the truncated cone shape portion has a cone angle of from 25° to 95° and a diameter of the top surface of from 5 ?m to 200 ?m.
    Type: Application
    Filed: February 17, 2004
    Publication date: July 6, 2006
    Applicant: Denki Kagaku Kogyo Kabushiki Kaisha
    Inventors: Yoshinori Terui, Ryozo Nongaki, Seiichi Sakawa
  • Patent number: 6630794
    Abstract: An S/N ratio of a probe current is measured while a filament current is changed, and the filament current in which the S/N ratio is maximal is determined.
    Type: Grant
    Filed: November 14, 2001
    Date of Patent: October 7, 2003
    Assignee: Denki Kagaku Kygyo Kabushiki Kaisha
    Inventors: Seiichi Sakawa, Yoshinori Terui
  • Publication number: 20020060573
    Abstract: An S/N ratio of a probe current is measured while a filament current is changed, and the filament current in which the S/N ratio is maximal is determined.
    Type: Application
    Filed: November 14, 2001
    Publication date: May 23, 2002
    Applicant: Denki Kagaku Kogyo Kabushiki Kaisha
    Inventors: Seiichi Sakawa, Yoshinori Terui