Patents by Inventor Atsuhito Fukasawa

Atsuhito Fukasawa 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: 11118969
    Abstract: An electron tube includes a photoelectric surface, an avalanche photodiode, a focusing electrode part that accelerates and focuses the electrons E from the photoelectric surface toward the avalanche photodiode, and a casing including a stem provided with the avalanche photodiode. The stem is provided with a light incident hole through which the light is transmitted, and the periphery of the light incident hole is light-shielded by the stem. The focusing electrode part includes a first region provided with a light passage hole, and a second region provided with an electron passage hole that guides the electrons to the avalanche photodiode. The first region is formed on an axial line that connects the light incident hole and the photoelectric surface. The second region is formed on an axial line that connects the photoelectric surface and the avalanche photodiode.
    Type: Grant
    Filed: June 15, 2018
    Date of Patent: September 14, 2021
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Atsuhito Fukasawa, Yasuyuki Egawa, Shigeru Ichikawa, Yasuharu Negi
  • Publication number: 20200149959
    Abstract: An electron tube includes a photoelectric surface, an avalanche photodiode, a focusing electrode part that accelerates and focuses the electrons E from the photoelectric surface toward the avalanche photodiode, and a casing including a stem provided with the avalanche photodiode. The stem is provided with a light incident hole through which the light is transmitted, and the periphery of the light incident hole is light-shielded by the stem. The focusing electrode part includes a first region provided with a light passage hole, and a second region provided with an electron passage hole that guides the electrons to the avalanche photodiode. The first region is formed on an axial line that connects the light incident hole and the photoelectric surface. The second region is formed on an axial line that connects the photoelectric surface and the avalanche photodiode.
    Type: Application
    Filed: June 15, 2018
    Publication date: May 14, 2020
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Atsuhito FUKASAWA, Yasuyuki EGAWA, Shigeru ICHIKAWA, Yasuharu NEGI
  • Patent number: 8203266
    Abstract: An electron tube of the present invention includes: a vacuum vessel including a face plate portion and a stem portion arranged facing the face plate portion; a photocathode arranged in the vacuum vessel and formed on the face plate portion; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the face plate portion, and made of an insulating material; an electron detector arranged on the projection portion, made of a semiconductor, and having a first conductivity-type region and a second conductivity-type region; and a first conductive film covering a surface of the projection portion and to be electrically connected to the first conductivity-type region.
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: June 19, 2012
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Yasuyuki Egawa, Atsuhito Fukasawa, Motohiro Suyama
  • Patent number: 8080806
    Abstract: An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: December 20, 2011
    Assignees: Hamamatsu Photonics K.K., The Regents of the University of California
    Inventors: Motohiro Suyama, Atsuhito Fukasawa, Katsushi Arisaka, Hanguo Wang
  • Patent number: 8040060
    Abstract: An electron tube of the present invention includes: a vacuum vessel including a side tube portion made of glass and a plate-like member blocking one opening of the side tube portion and made of glass; a first metal film provided on an end face of the side tube portion; a second metal film arranged facing the first metal film and provided on a marginal part of a face at a vacuum side of the plate-like member; a third metal film provided on at least one of an outer wall face of the side tube portion adjacent to the end face and a side face of the plate-like member adjacent to the marginal part; and a metal member made of a low-melting-point metal, for sealing a gap between the side tube portion and the plate-like member while contacting the first metal film, the second metal film, and the third metal film.
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: October 18, 2011
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Atsuhito Fukasawa, Yasuyuki Egawa, Motohiro Suyama
  • Patent number: 7876033
    Abstract: An electron tube of the present invention includes: a vacuum vessel including a stem portion made of quartz and formed with an opening; a lid portion connected to the stem portion via a joining member made of aluminum so as to seal the opening, having a recess portion depressed to a vacuum side in the opening, and made of Kovar; a voltage applying section arranged in the vacuum vessel; and wiring for electrically connecting the voltage applying section and the lid portion.
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: January 25, 2011
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Tomohiro Ishizu, Yasuyuki Egawa, Atsuhito Fukasawa, Motohiro Suyama
  • Publication number: 20100102408
    Abstract: An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.
    Type: Application
    Filed: October 23, 2008
    Publication date: April 29, 2010
    Applicants: HAMAMATSU PHOTONICS K.K., THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Motohiro SUYAMA, Atsuhito FUKASAWA, Katsushi ARISAKA, Hanguo WANG
  • Publication number: 20100102720
    Abstract: An electron tube of the present invention includes: a vacuum vessel including a face plate portion and a stem portion arranged facing the face plate portion; a photocathode arranged in the vacuum vessel and formed on the face plate portion; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the face plate portion, and made of an insulating material; an electron detector arranged on the projection portion, made of a semiconductor, and having a first conductivity-type region and a second conductivity-type region; and a first conductive film covering a surface of the projection portion and to be electrically connected to the first conductivity-type region.
    Type: Application
    Filed: October 23, 2008
    Publication date: April 29, 2010
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Yasuyuki EGAWA, Atsuhito FUKASAWA, Motohiro SUYAMA
  • Publication number: 20100102721
    Abstract: An electron tube of the present invention includes: a vacuum vessel including a side tube portion made of glass and a plate-like member blocking one opening of the side tube portion and made of glass; a first metal film provided on an end face of the side tube portion; a second metal film arranged facing the first metal film and provided on a marginal part of a face at a vacuum side of the plate-like member; a third metal film provided on at least one of an outer wall face of the side tube portion adjacent to the end face and a side face of the plate-like member adjacent to the marginal part; and a metal member made of a low-melting-point metal, for sealing a gap between the side tube portion and the plate-like member while contacting the first metal film, the second metal film, and the third metal film.
    Type: Application
    Filed: October 23, 2008
    Publication date: April 29, 2010
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Atsuhito Fukasawa, Yasuyuki Egawa, Motohiro Suyama
  • Publication number: 20100102701
    Abstract: An electron tube of the present invention includes: a vacuum vessel including a stem portion made of quartz and formed with an opening; a lid portion connected to the stem portion via a joining member made of aluminum so as to seal the opening, having a recess portion depressed to a vacuum side in the opening, and made of Kovar; a voltage applying section arranged in the vacuum vessel; and wiring for electrically connecting the voltage applying section and the lid portion.
    Type: Application
    Filed: October 23, 2008
    Publication date: April 29, 2010
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Tomohiro ISHIZU, Yasuyuki EGAWA, Atsuhito FUKASAWA, Motohiro SUYAMA
  • Patent number: 7692384
    Abstract: An envelope has a glass bulb body and a cylindrical glass bulb base. The glass bulb body includes an upper hemisphere and a lower hemisphere. The upper hemisphere is curved in a substantially spherical shape. The lower hemisphere is substantially curved in a spherical shape and connects the upper hemisphere and glass bulb base. A photocathode is formed on the inner surface of the glass bulb body. An avalanche photodiode is disposed on the glass bulb body side relative to an intersection between an imaginary extended curved surface of the lower hemisphere within the glass bulb base and an axis. When light enters the photocathode, electrons are emitted from the photocathode. The electrons are converged at the position above and in the vicinity of the APD by an electrical field in the electron tube, so that the electrons enter the APD in an efficient manner and are detected satisfactorily.
    Type: Grant
    Filed: March 8, 2006
    Date of Patent: April 6, 2010
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Hiroyuki Kyushima, Motohiro Suyama, Suenori Kimura, Yasuharu Negi, Atsuhito Fukasawa, Yoshihiko Kawai, Atsushi Uchiyama, Yasuyuki Egawa
  • Patent number: 7525249
    Abstract: In an electron tube, an insulating tube protrudes inside an envelope. One end of the insulating tube is connected to the envelope. An avalanche photo diode (APD) is provided on the other end of the insulating tube. A ground voltage is applied to the envelope and a positive high voltage is applied to the APD. Photoelectrons which are emitted in response to an incident light on a photocathode are converged by an electrical field in the envelope and enter the APD. Thereafter, the incident photoelectrons are amplified and detected. Since a positive high voltage is not exposed to the envelope, the electron tube can easily be handled and is excellent in safety.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: April 28, 2009
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Motohiro Suyama, Hiroyuki Kyushima, Suenori Kimura, Yasuharu Negi, Atsuhito Fukasawa, Yoshihiko Kawai, Atsushi Uchiyama, Yasuyuki Egawa
  • Patent number: 7491918
    Abstract: An insulating tube has one end and another end. An avalanche photodiode (APD) is provided outside the one end of the insulating tube. The another end of the insulating tube is air-tightly connected to an outer flange through a stem inner wall. Capacitors electrically connected to the APD are provided in the insulating tube. The capacitors remove direct current components from signals that the APD generates when detecting electrons. By providing the capacitors in the insulating tube, response of output signals can be prevented from being impaired.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: February 17, 2009
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Hiroyuki Kyushima, Motohiro Suyama, Suenori Kimura, Yasuharu Negi, Yoshihiko Kawai, Atsuhito Fukasawa
  • Patent number: 7176429
    Abstract: In an electron tube, one end of an insulating tube is protruded toward the inside of an envelope, and an avalanche photodiode (APD) is provided on the one end of the insulating tube. Another end of the insulating tube is connected to an outer stem of the envelope. Alkali sources are provided inside the envelope. The alkali sources are disposed inside the envelope and generates alkali metal vapor to thereby form a photocathode on a predetermined part of the internal surface of the envelope. The alkali sources and insulating tube are isolated from each other by a separating member. When the electron tube is manufactured, the alkali metal vapor that is generated from the alkali sources is not deposited on the insulating tube due to existence of the separating member. This prevents voltage resistance between the envelope and APD from being decreased and the electrical field in the electron tube from being adversely affected, thereby preventing incident efficiency of electrons to the APD from being decreased.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: February 13, 2007
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Motohiro Suyama, Hiroyuki Kyushima, Yasuharu Negi, Atsuhito Fukasawa, Yoshihiko Kawai, Yasuyuki Egawa, Atsushi Uchiyama, Suenori Kimura
  • Publication number: 20070029930
    Abstract: In an electron tube, an insulating tube protrudes inside an envelope. One end of the insulating tube is connected to the envelope. An avalanche photo diode (APD) is provided on the other end of the insulating tube. A ground voltage is applied to the envelope and a positive high voltage is applied to the APD. Photoelectrons which are emitted in response to an incident light on a photocathode are converged by an electrical field in the envelope and enter the APD. Thereafter, the incident photoelectrons are amplified and detected. Since a positive high voltage is not exposed to the envelope, the electron tube can easily be handled and is excellent in safety.
    Type: Application
    Filed: September 9, 2004
    Publication date: February 8, 2007
    Applicant: Hamamatsu Photonics K.K.
    Inventors: Motohiro Suyama, Hiroyuki Kyushima, Suenori Kimura, Yasuharu Negi, Atsuhito Fukasawa, Yoshihiko Kawai, Atshushi Uchiyama, Yasuyuki Egawa
  • Publication number: 20070023652
    Abstract: An insulating tube has one end and another end. An An avalanche photodiode (APD) is provided outside the one end of the insulating tube. The another end of the insulating tube is air-tightly connected to an outer flange through a stem inner wall. Capacitors electrically connected to the APD are provided in the insulating tube. The capacitors remove direct current components from signals that the APD generates when detecting electrons. By providing the capacitors in the insulating tube, response of output signals can be prevented from being impaired.
    Type: Application
    Filed: September 9, 2004
    Publication date: February 1, 2007
    Applicant: Hamamatsu Photonics K.K.
    Inventors: Hiroyuki Kyushima, Motohiro Suyama, Suenori Kimura, Yasuharu Negi, Yoshihiko Kawai, Atsuhito Fukasawa
  • Publication number: 20070001093
    Abstract: In an electron tube, one end of an insulating tube is protruded toward the inside of an envelope, and an avalanche photodiode (APD) is provided on the one end of the insulating tube. Another end of the insulating tube is connected to an outer stem of the envelope. Alkali sources are provided inside the envelope. The alkali sources are disposed inside the envelope and generates alkali metal vapor to thereby form a photocathode on a predetermined part of the internal surface of the envelope. The alkali sources and insulating tube are isolated from each other by a separating member. When the electron tube is manufactured, the alkali metal vapor that is generated from the alkali sources is not deposited on the insulating tube due to existence of the separating member. This prevents voltage resistance between the envelope and APD from being decreased and the electrical field in the electron tube from being adversely affected, thereby preventing incident efficiency of electrons to the APD from being decreased.
    Type: Application
    Filed: September 9, 2004
    Publication date: January 4, 2007
    Applicant: Hamamatsu Photonics K.K
    Inventors: Motohiro Suyama, Hiroyuki Kyushima, Yasuharu Negi, Atsuhito Fukasawa, Yoshihiko Kawai, Yasuyuki Egawa, Atsushi Uchiyama, Suenori Kimura