Patents by Inventor Yasumasa Hamana

Yasumasa Hamana 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: 11011358
    Abstract: The present embodiment relates to an electron multiplier having a structure configured to suppress and stabilize a variation of a resistance value in a wider temperature range. In the electron multiplier, a resistance layer sandwiched between a substrate and a secondary electron emitting layer formed of an insulating material includes a metal layer in which a plurality of metal particles formed of a metal material whose resistance value has a positive temperature characteristic are two-dimensionally arranged on a layer formation surface, which is coincident with or substantially parallel to a channel formation surface of the substrate, in the state of being adjacent to each other with a part of the first insulating material interposed therebetween, the metal layer having a thickness set to 5 to 40 angstroms.
    Type: Grant
    Filed: April 10, 2018
    Date of Patent: May 18, 2021
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Daichi Masuko, Hajime Nishimura, Yasumasa Hamana, Hiroyuki Watanabe
  • Publication number: 20210134572
    Abstract: The present embodiment relates to an electron multiplier having a structure configured to suppress and stabilize a variation of a resistance value in a wider temperature range. The electron multiplier includes a resistance layer sandwiched between a substrate and a secondary electron emitting layer and configured using a Pt layer two-dimensionally formed on a layer formation surface which is coincident with or substantially parallel to a channel formation surface of the substrate. The resistance layer has a temperature characteristic within a range in which a resistance value at ?60° C. is 10 times or less, and a resistance value at +60° C. is 0.25 times or more, relative to a resistance value at a temperature of 20° C.
    Type: Application
    Filed: April 10, 2018
    Publication date: May 6, 2021
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Daichi MASUKO, Hajime NISHIMURA, Yasumasa HAMANA, Hiroyuki WATANABE
  • Publication number: 20210118655
    Abstract: The present embodiment relates to an electron multiplier having a structure configured to suppress and stabilize a variation of a resistance value in a wider temperature range. In the electron multiplier, a resistance layer sandwiched between a substrate and a secondary electron emitting layer comprised of an insulating material includes a metal layer in which a plurality of metal particles comprised of a metal material whose resistance value has a positive temperature characteristic are two-dimensionally arranged on a layer formation surface, which is coincident with or substantially parallel to a channel formation surface of the substrate, in the state of being adjacent to each other with a part of the first insulating material interposed therebetween, the metal layer having a thickness set to 5 to 40 angstroms.
    Type: Application
    Filed: April 10, 2018
    Publication date: April 22, 2021
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Daichi MASUKO, Hajime NISHIMURA, Yasumasa HAMANA, Hiroyuki WATANABE
  • Patent number: 10818484
    Abstract: A microchannel plate is provided with a substrate including a front surface, a rear surface, and a side surface, a plurality of channels penetrating from the front surface to the rear surface of the substrate, a first film provided on at least an inner wall surface of the channel, a second film provided on at least a part of the first film, and electrode layers provided on the front surface and the rear surface of the substrate. The first film is made of MgO, the second film is made of SiO2, and the second film is thinner than the first film.
    Type: Grant
    Filed: January 23, 2018
    Date of Patent: October 27, 2020
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Takaaki Nagata, Yasumasa Hamana, Hajime Nishimura, Daichi Masuko
  • Patent number: 10790129
    Abstract: A transmissive photocathode includes a light transmitting substrate that has a first surface on which light is incident and a second surface which emits light incident from a side of the first surface, a photoelectric conversion layer that is provided on the second surface side of the light transmitting substrate and converts the light emitted from the second surface into photoelectrons, a light transmitting conductive layer that is provided between the light transmitting substrate and the photoelectric conversion layer and is composed of a single-layered graphene, and a thermal stress alleviation layer that is provided between the photoelectric conversion layer and the light transmitting conductive layer and has light transmissivity. A thermal expansion coefficient of the thermal stress alleviation layer is smaller than a thermal expansion coefficient of the photoelectric conversion layer and larger than a thermal expansion coefficient of the graphene.
    Type: Grant
    Filed: May 14, 2018
    Date of Patent: September 29, 2020
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Takaaki Nagata, Yoshihiro Ishigami, Yasumasa Hamana
  • Patent number: 10727035
    Abstract: The present embodiment relates to an electron multiplier having a structure configured to suppress and stabilize a variation of a resistance value in a wider temperature range. In the electron multiplier, a resistance layer sandwiched between a substrate and a secondary electron emitting layer comprised of an insulating material is configured using a single metal layer in which a plurality of metal particles comprised of a metal material whose resistance value has a positive temperature characteristic are two-dimensionally arranged on a layer formation surface, which is coincident with or substantially parallel to a channel formation surface of the substrate, in the state of being adjacent to each other with a part of the first insulating material interposed therebetween.
    Type: Grant
    Filed: April 10, 2018
    Date of Patent: July 28, 2020
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Daichi Masuko, Yasumasa Hamana, Hajime Nishimura, Hiroyuki Watanabe
  • Publication number: 20200234935
    Abstract: A transmissive photocathode includes a light transmitting substrate that has a first surface on which light is incident and a second surface which emits light incident from a side of the first surface, a photoelectric conversion layer that is provided on the second surface side of the light transmitting substrate and converts the light emitted from the second surface into photoelectrons, a light transmitting conductive layer that is provided between the light transmitting substrate and the photoelectric conversion layer and is composed of a single-layered graphene, and a thermal stress alleviation layer that is provided between the photoelectric conversion layer and the light transmitting conductive layer and has light transmissivity. A thermal expansion coefficient of the thermal stress alleviation layer is smaller than a thermal expansion coefficient of the photoelectric conversion layer and larger than a thermal expansion coefficient of the graphene.
    Type: Application
    Filed: May 14, 2018
    Publication date: July 23, 2020
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Takaaki NAGATA, Yoshihiro ISHIGAMI, Yasumasa HAMANA
  • Publication number: 20200176236
    Abstract: The present embodiment relates to an electron multiplier having a structure configured to suppress and stabilize a variation of a resistance value in a wider temperature range. In the electron multiplier, a resistance layer sandwiched between a substrate and a secondary electron emitting layer comprised of an insulating material is configured using a single metal layer in which a plurality of metal particles comprised of a metal material whose resistance value has a positive temperature characteristic are two-dimensionally arranged on a layer formation surface, which is coincident with or substantially parallel to a channel formation surface of the substrate, in the state of being adjacent to each other with a part of the first insulating material interposed therebetween.
    Type: Application
    Filed: April 10, 2018
    Publication date: June 4, 2020
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Daichi MASUKO, Yasumasa HAMANA, Hajime NISHIMURA, Hiroyuki WATANABE
  • Publication number: 20200027709
    Abstract: A microchannel plate is provided with a substrate including a front surface, a rear surface, and a side surface, a plurality of channels penetrating from the front surface to the rear surface of the substrate, a first film provided on at least an inner wall surface of the channel, a second film provided on at least a part of the first film, and electrode layers provided on the front surface and the rear surface of the substrate. The first film is made of MgO, the second film is made of SiO2, and the second film is thinner than the first film.
    Type: Application
    Filed: January 23, 2018
    Publication date: January 23, 2020
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Takaaki NAGATA, Yasumasa HAMANA, Hajime NISHIMURA, Daichi MASUKO
  • Patent number: 10340129
    Abstract: A microchannel plate is provided with a substrate including a front surface, a rear surface, and a side surface, a plurality of channels penetrating from the front surface to the rear surface of the substrate, a first film provided on at least an inner wall surface of the channel, a second film provided on the first film, and electrode layers provided on the front surface and the rear surface of the substrate. The first film is made of Al2O3. The second film is made of SiO2. The first film is thicker than the second film.
    Type: Grant
    Filed: August 9, 2016
    Date of Patent: July 2, 2019
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Takaaki Nagata, Yasumasa Hamana, Hajime Nishimura, Kimitsugu Nakamura
  • Publication number: 20180247802
    Abstract: A microchannel plate is provided with a substrate including a front surface, a rear surface, and a side surface, a plurality of channels penetrating from the front surface to the rear surface of the substrate, a first film provided on at least an inner wall surface of the channel, a second film provided on the first film, and electrode layers provided on the front surface and the rear surface of the substrate. The first film is made of Al2O3. The second film is made of SiO2. The first film is thicker than the second film.
    Type: Application
    Filed: August 9, 2016
    Publication date: August 30, 2018
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Takaaki NAGATA, Yasumasa HAMANA, Hajime NISHIMURA, Kimitsugu NAKAMURA
  • Patent number: 9824844
    Abstract: A transmission mode photocathode comprises: an optically transparent substrate having an outside face to which light is incident, and an inside face from which the light incident to the outside face side is output; a photoelectric conversion layer disposed on the inside face side of the optically transparent substrate and configured to convert the light output from the inside face into a photoelectron or photoelectrons; and an optically-transparent electroconductive layer comprising graphene, and disposed between the optically transparent substrate and the photoelectric conversion layer.
    Type: Grant
    Filed: August 8, 2014
    Date of Patent: November 21, 2017
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Takaaki Nagata, Yasumasa Hamana, Kimitsugu Nakamura
  • Publication number: 20160233044
    Abstract: A transmission mode photocathode comprises: an optically transparent substrate having an outside face to which light is incident, and an inside face from which the light incident to the outside face side is output; a photoelectric conversion layer disposed on the inside face side of the optically transparent substrate and configured to convert the light output from the inside face into a photoelectron or photoelectrons; and an optically-transparent electroconductive layer comprising graphene, and disposed between the optically transparent substrate and the photoelectric conversion layer.
    Type: Application
    Filed: August 8, 2014
    Publication date: August 11, 2016
    Inventors: Takaaki NAGATA, Yasumasa HAMANA, Kimitsugu NAKAMURA
  • Patent number: 9299530
    Abstract: In an electron tube, an atomic layer deposition method is used to form an electrical resistance film having a stacked structure of electrically insulating layers and electrically conductive layers or a mixed structure of an electrically insulating material and an electrically conductive material, so as to cover the whole of an inner wall surface and an outer wall surface of a second envelope. By use of the atomic layer deposition method, the firm and fine electrical resistance film with a desired resistance can be formed on an insulation surface, without containing a material such as a binder. When the electrical resistance film is provided with slight electrical conductivity, it can suppress occurrence of withstand voltage failure due to electrification of the insulation surface or the like and realize stability of withstand voltage characteristics.
    Type: Grant
    Filed: July 31, 2013
    Date of Patent: March 29, 2016
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Yasumasa Hamana, Takaaki Nagata, Kimitsugu Nakamura
  • Patent number: 9293308
    Abstract: In an electron tube, an electrical resistance film having a stacked structure of electrically insulating layers and electrically conductive layers is formed on holding surfaces of bases in insulating substrates. This electrical resistance film is made as a firm and fine film with a desired resistance by use of an atomic layer deposition method, which can suppress electrification of the bases comprised of an insulating material. This makes it feasible to stably maintain withstand voltage characteristics.
    Type: Grant
    Filed: July 31, 2013
    Date of Patent: March 22, 2016
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Takaaki Nagata, Yasumasa Hamana, Kimitsugu Nakamura
  • Patent number: 9257266
    Abstract: In a micro-channel plate, an electron emission film and an ion barrier film formed on a substrate are integrally formed by the same film formation step. In this structure, the electron emission film and the ion barrier film are made as continuous and firm films and the ion barrier film can be made thinner. Since the ion barrier film is formed on the back side of an organic film, the organic film is exposed during removal of the organic film. This prevents the organic film from remaining and thus suppresses degradation of performance of the ion barrier film due to the residual organic film, so as to suppress ion feedback from the micro-channel plate and achieve a sufficient improvement in life characteristics of an image intensifier.
    Type: Grant
    Filed: July 11, 2013
    Date of Patent: February 9, 2016
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Kimitsugu Nakamura, Yasumasa Hamana, Takaaki Nagata
  • Publication number: 20150279639
    Abstract: In a micro-channel plate, an electron emission film and an ion barrier film formed on a substrate are integrally formed by the same film formation step. In this structure, the electron emission film and the ion barrier film are made as continuous and firm films and the ion barrier film can be made thinner. Since the ion barrier film is formed on the back side of an organic film, the organic film is exposed during removal of the organic film. This prevents the organic film from remaining and thus suppresses degradation of performance of the ion barrier film due to the residual organic film, so as to suppress ion feedback from the micro-channel plate and achieve a sufficient improvement in life characteristics of an image intensifier.
    Type: Application
    Filed: July 11, 2013
    Publication date: October 1, 2015
    Inventors: Kimitsugu Nakamura, Yasumasa Hamana, Takaaki Nagata
  • Publication number: 20150235825
    Abstract: In an electron tube, an electrical resistance film having a stacked structure of electrically insulating layers and electrically conductive layers is formed on holding surfaces of bases in insulating substrates. This electrical resistance film is made as a firm and fine film with a desired resistance by use of an atomic layer deposition method, which can suppress electrification of the bases comprised of an insulating material. This makes it feasible to stably maintain withstand voltage characteristics.
    Type: Application
    Filed: July 31, 2013
    Publication date: August 20, 2015
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Takaaki Nagata, Yasumasa Hamana, Kimitsugu Nakamura
  • Publication number: 20150228439
    Abstract: In an electron tube, an atomic layer deposition method is used to form an electrical resistance film having a stacked structure of electrically insulating layers and electrically conductive layers or a mixed structure of an electrically insulating material and an electrically conductive material, so as to cover the whole of an inner wall surface and an outer wall surface of a second envelope. By use of the atomic layer deposition method, the firm and fine electrical resistance film with a desired resistance can be formed on an insulation surface, without containing a material such as a binder. When the electrical resistance film is provided with slight electrical conductivity, it can suppress occurrence of withstand voltage failure due to electrification of the insulation surface or the like and realize stability of withstand voltage characteristics.
    Type: Application
    Filed: July 31, 2013
    Publication date: August 13, 2015
    Inventors: Yasumasa Hamana, Takaaki Nagata, Kimitsugu Nakamura
  • Patent number: 8796923
    Abstract: The present invention aims at providing a photocathode which can improve various characteristics. In a photocathode 10, an intermediate layer 14, an underlayer 16, and a photoelectron emission layer 18 are formed in this order on a substrate 12. The photoelectron emission layer 18 contains Sb and Bi and functions to emit a photoelectron in response to light incident thereon. The photoelectron emission layer 18 contains 32 mol % or less of Bi relative to SbBi. This can dramatically improve the linearity at low temperatures.
    Type: Grant
    Filed: November 7, 2008
    Date of Patent: August 5, 2014
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Toshikazu Matsui, Yasumasa Hamana, Kimitsugu Nakamura, Yoshihiro Ishigami, Daijiro Oguri