Patents by Inventor Yasufumi Takagi

Yasufumi Takagi 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: 10840762
    Abstract: A brushless motor includes a stator including teeth each including a constricted portion on which a coil is to be wound, and a tip end portion including a confronting surface that faces a rotor and having a width greater than that of the constricted portion. A spacer includes closure members disposed between adjacent ones of the tip end portions, and fitted to the teeth so that the confronting surfaces of the teeth are exposed toward the rotor.
    Type: Grant
    Filed: October 15, 2015
    Date of Patent: November 17, 2020
    Assignee: YAMAHA MOTOR ELECTRONICS CO., LTD.
    Inventors: Toshihiko Nagata, Yasufumi Takagi, Tomonari Shiraishi
  • Patent number: 10840406
    Abstract: An optical semiconductor element includes: an optical waveguide body; a first electrode that is disposed on the second clad layer; a second electrode that is disposed on a second clad layer on one side of the first electrode in a light guiding direction of the optical waveguide body; a third electrode that is disposed on the second clad layer on the other side of the first electrode in the light guiding direction; and at least one fourth electrode that faces the first electrode, the second electrode, and the third electrode with the optical waveguide body interposed therebetween. The optical waveguide body includes a first separation region that electrically separates a first region under the first electrode from a second region under the second electrode and a second separation region that electrically separates the first region under the first electrode and a third region under the third electrode.
    Type: Grant
    Filed: February 23, 2018
    Date of Patent: November 17, 2020
    Assignee: HAMAMATSU PHOTONICS K.K.
    Inventors: Masamichi Yamanishi, Akira Higuchi, Toru Hirohata, Kazunori Tanaka, Kazuue Fujita, Yasufumi Takagi, Yuta Aoki, Satoru Okawara
  • Publication number: 20180301591
    Abstract: An optical semiconductor element includes: an optical waveguide body; a first electrode that is disposed on a second clad layer; a second electrode that is disposed on the second clad layer on one side of the first electrode in a light guiding direction of the optical waveguide body; a third electrode that is disposed on the second clad layer on the other side of the first electrode in the light guiding direction; and at least one fourth electrode that faces the first electrode, the second electrode, and the third electrode with the optical waveguide body interposed therebetween. The optical waveguide body includes a first separation region that electrically separates a first region under the first electrode from a second region under the second electrode and a second separation region that electrically separates the first region under the first electrode and a third region under the third electrode.
    Type: Application
    Filed: February 23, 2018
    Publication date: October 18, 2018
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Masamichi YAMANISHI, Akira HIGUCHI, Toru HIROHATA, Kazunori TANAKA, Kazuue FUJITA, Yasufumi TAKAGI, Yuta AOKI, Satoru OKAWARA
  • Publication number: 20180034338
    Abstract: A brushless motor includes a stator including teeth each including a constricted portion on which a coil is to be wound, and a tip end portion including a confronting surface that faces a rotor and having a width greater than that of the constricted portion. A spacer includes closure members disposed between adjacent ones of the tip end portions, and fitted to the teeth so that the confronting surfaces of the teeth are exposed toward the rotor.
    Type: Application
    Filed: October 15, 2015
    Publication date: February 1, 2018
    Inventors: Toshihiko NAGATA, Yasufumi TAKAGI, Tomonari SHIRAISHI
  • Patent number: 8759837
    Abstract: A nitride semiconductor substrate is featured in comprising: a GaN semiconductor layer grown on a base layer, which has a substantially triangular cross-section along the thickness direction thereof, a periodic stripe shapes, and uneven surfaces arranged on the stripes inclined surfaces; and an overgrown layer composed of AlGaN or InAlGaN on the GaN semiconductor layer.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: June 24, 2014
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Harumasa Yoshida, Yasufumi Takagi, Masakazu Kuwabara
  • Patent number: 8237194
    Abstract: A nitride semiconductor substrate is featured in comprising: a GaN semiconductor layer grown on a base layer, which has a substantially triangular cross-section along the thickness direction thereof, a periodic stripe shapes, and uneven surfaces arranged on the stripes inclined surfaces; and an overgrown layer composed of AlGaN or InAlGaN on the GaN semiconductor layer.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: August 7, 2012
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Harumasa Yoshida, Yasufumi Takagi, Masakazu Kuwabara
  • Publication number: 20120175633
    Abstract: A nitride semiconductor substrate is featured in comprising: a GaN semiconductor layer grown on a base layer, which has a substantially triangular cross-section along the thickness direction thereof, a periodic stripe shapes, and uneven surfaces arranged on the stripes inclined surfaces; and an overgrown layer composed of AlGaN or InAlGaN on the GaN semiconductor layer.
    Type: Application
    Filed: March 21, 2012
    Publication date: July 12, 2012
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Harumasa YOSHIDA, Yasufumi Takagi, Masakazu Kuwabara
  • Patent number: 8164069
    Abstract: A light-emitting body of rapid speed of response and high light emission intensity, and an electron beam detector, scanning electron microscope and mass spectroscope using this are provided. In the light-emitting body 10 according to the present invention, when fluorescence is emitted by a nitride semiconductor layer 14 formed on one face 12a of a substrate 12 in response to incidence of electrons, at least some of this fluorescence is transmitted through this substrate 12, whereby that fluorescence is emitted from the other face 12b of the substrate. The response speed of this fluorescence is not more than ?sec order. Also, the intensity of emission of this fluorescence is almost identical to that of a conventional P47 phosphor. Specifically, with this light-emitting body 10, a response speed and light emission intensity are obtained that are fully satisfactory for application to a scanning electron microscope or mass spectroscope.
    Type: Grant
    Filed: January 10, 2011
    Date of Patent: April 24, 2012
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Shoichi Uchiyama, Yasufumi Takagi, Minoru Niigaki, Minoru Kondo, Itaru Mizuno
  • Patent number: 8056918
    Abstract: A saddle riding type vehicle includes a vehicle body frame, a head pipe, a steering shaft, and a steering damper. The head pipe is attached to the front end of the vehicle body frame. The steering shaft is inserted rotatably in the head pipe. The steering damper includes an electromagnet, a magnetic member, and a magnetic fluid. The electromagnet is provided around the steering shaft and has a first surface. The magnetic member is provided around the steering shaft and has a second surface opposed to the first surface. The magnetic fluid is stored in a gap formed between the first and second surfaces. One of the electromagnet and the magnetic member is attached to the steering shaft and the other is attached to the head pipe.
    Type: Grant
    Filed: April 22, 2010
    Date of Patent: November 15, 2011
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Shidehiko Miyashiro, Nobuo Hara, Naoyuki Hosono, Yasufumi Takagi, Takayuki Suzuki
  • Publication number: 20110101219
    Abstract: A light-emitting body of rapid speed of response and high light emission intensity, and an electron beam detector, scanning electron microscope and mass spectroscope using this are provided. In the light-emitting body 10 according to the present invention, when fluorescence is emitted by a nitride semiconductor layer 14 formed on one face 12a of a substrate 12 in response to incidence of electrons, at least some of this fluorescence is transmitted through this substrate 12, whereby that fluorescence is emitted from the other face 12b of the substrate. The response speed of this fluorescence is not more than ?sec order. Also, the intensity of emission of this fluorescence is almost identical to that of a conventional P47 phosphor. Specifically, with this light-emitting body 10, a response speed and light emission intensity are obtained that are fully satisfactory for application to a scanning electron microscope or mass spectroscope.
    Type: Application
    Filed: January 10, 2011
    Publication date: May 5, 2011
    Inventors: Shoichi UCHIYAMA, Yasufumi TAKAGI, Minoru NIIGAKI, Minoru KONDO, Itaru MIZUNO
  • Patent number: 7910895
    Abstract: A light-emitting body of rapid speed of response and high light emission intensity, and an electron beam detector, scanning electron microscope and mass spectroscope using this are provided. In the light-emitting body 10 according to the present invention, when fluorescence is emitted by a nitride semiconductor layer 14 formed on one face 12a of a substrate 12 in response to incidence of electrons, at least some of this fluorescence is transmitted through this substrate 12, whereby that fluorescence is emitted from the other face 12b of the substrate. The response speed of this fluorescence is not more than ?sec order. Also, the intensity of emission of this fluorescence is almost identical to that of a conventional P47 phosphor. Specifically, with this light-emitting body 10, a response speed and light emission intensity are obtained that are fully satisfactory for application to a scanning electron microscope or mass spectroscope.
    Type: Grant
    Filed: April 7, 2005
    Date of Patent: March 22, 2011
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Shoichi Uchiyama, Yasufumi Takagi, Minoru Niigaki, Minoru Kondo, Itaru Mizuno
  • Publication number: 20100270773
    Abstract: A saddle riding type vehicle includes a vehicle body frame, a head pipe, a steering shaft, and a steering damper. The head pipe is attached to the front end of the vehicle body frame. The steering shaft is inserted rotatably in the head pipe. The steering damper includes an electromagnet, a magnetic member, and a magnetic fluid. The electromagnet is provided around the steering shaft and has a first surface. The magnetic member is provided around the steering shaft and has a second surface opposed to the first surface. The magnetic fluid is stored in a gap formed between the first and second surfaces. One of the electromagnet and the magnetic member is attached to the steering shaft and the other is attached to the head pipe.
    Type: Application
    Filed: April 22, 2010
    Publication date: October 28, 2010
    Applicant: YAMAHA HATSUDOKI KABUSHIKI KAISHA
    Inventors: Shidehiko MIYASHIRO, Nobuo HARA, Naoyuki HOSONO, Yasufumi TAKAGI, Takayuki SUZUKI
  • Publication number: 20100102328
    Abstract: A nitride semiconductor substrate is featured in comprising: a GaN semiconductor layer grown on a base layer, which has a substantially triangular cross-section along the thickness direction thereof, a periodic stripe shapes, and uneven surfaces arranged on the stripes inclined surfaces; and an overgrown layer composed of AlGaN or InAlGaN on the GaN semiconductor layer.
    Type: Application
    Filed: March 17, 2008
    Publication date: April 29, 2010
    Applicant: HAMAMATSU PHOTONICKS K.K
    Inventors: Harumasa Yoshida, Yasufumi Takagi, Masakazu Kuwabara
  • Publication number: 20080116368
    Abstract: A light-emitting body of rapid speed of response and high light emission intensity, and an electron beam detector, scanning electron microscope and mass spectroscope using this are provided. In the light-emitting body 10 according to the present invention, when fluorescence is emitted by a nitride semiconductor layer 14 formed on one face 12a of a substrate 12 in response to incidence of electrons, at least some of this fluorescence is transmitted through this substrate 12, whereby that fluorescence is emitted from the other face 12b of the substrate. The response speed of this fluorescence is not more than ?sec order. Also, the intensity of emission of this fluorescence is almost identical to that of a conventional P47 phosphor. Specifically, with this light-emitting body 10, a response speed and light emission intensity are obtained that are fully satisfactory for application to a scanning electron microscope or mass spectroscope.
    Type: Application
    Filed: April 7, 2005
    Publication date: May 22, 2008
    Applicant: HAMAMATSU PHOTONICS K.K.
    Inventors: Shoichi Uchiyama, Yasufumi Takagi, Minoru Niigaki, Minoru Kondo, Itaru Mizuno
  • Publication number: 20070176160
    Abstract: A GaN-based semiconductor photocathode is applied to an electron tube. A GaN-based compound semiconductor layer is laterally grown on a substrate, and incorporated in the electron tube. The crystal defects of the compound semiconductor layer are reduced, whereby an electron tube which has inconceivably high sensitivity is realized.
    Type: Application
    Filed: January 27, 2006
    Publication date: August 2, 2007
    Inventors: Shoichi Uchiyama, Yasufumi Takagi, Harumasa Yoshida
  • Patent number: 7217932
    Abstract: A UV sensor (1) includes a container (5) in which the upper end opening of a metal side tube (2) is sealed with a front plate (3) composed of borosilicate glass as an incident light window and the lower end opening is sealed with a base plate (4). The front plate (3) serving as an incident light window constitutes part of the wall of container (5) by sealing the upper end opening of the metal side tube (2). A pin-type photodiode (6) is disposed inside the container (5). The pin-type photodiode (6) comprises a photoabsorption layer (9) formed from InxGa(1?x)N (0<x<1) between an n-type contact layer (8) and a p-type contact layer (10).
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: May 15, 2007
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Yasufumi Takagi, Kazutoshi Nakajima, Yoshitaka Suzuki, Nobuharu Suzuki
  • Patent number: 7030388
    Abstract: The present invention relates to an illuminant, etc., having a high response speed and a high luminous intensity. The illuminant comprises a substrate and a nitride semiconductor layer provided on one surface of the substrate. The nitride semiconductor layer emits fluorescence in response to incidence of electrons. At least part of the emitted fluorescence passes through the substrate, and then exits from the other surface of the substrate. Generation of the fluorescence is caused by incidence of electrons onto a quantum well structure of the nitride semiconductor layer and recombination of pairs of electrons and holes generated due to electron incidence, and the response speed of fluorescence generation is on the order of nanoseconds or less. Also, the luminous intensity of the fluorescence becomes equivalent to that of a conventional P47 fluorescent substance.
    Type: Grant
    Filed: October 7, 2003
    Date of Patent: April 18, 2006
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Yasufumi Takagi, Minoru Niigaki, Shoichi Uchiyama, Minoru Kondo, Itaru Mizuno
  • Publication number: 20050045866
    Abstract: Ultraviolet light incident from the side of a surface layer 5 passes through the surface layer 5 to reach an optical absorption layer 4. Light which reaches the optical absorption layer 4 is absorbed within the optical absorption layer 4, and photoelectrons are generated within the optical absorption layer 4. Photoelectrons diffuse within the optical absorption layer 4, and reach the interface between the optical absorption layer 4 and the surface layer 5. Because the energy band is curved in the vicinity of the interface between the optical absorption layer 4 and surface layer 5, the energy of the photoelectrons is larger than the electron affinity in the surface layer 5, and so photoelectrons are easily ejected to the outside. Here, the optical absorption layer 4 is formed from an Al0.3Ga0.7N layer with an Mg content concentration of not less than 2×1019 cm?3 but not more than 1×1020 cm?3, so that a solar-blind type semiconductor photocathode 1 with high quantum efficiency is obtained.
    Type: Application
    Filed: October 12, 2004
    Publication date: March 3, 2005
    Inventors: Hirofumi Kan, Minoru Niigaki, Masashi Ohta, Yasufumi Takagi, Shoichi Uchiyama
  • Patent number: 6831341
    Abstract: Ultraviolet light incident from the side of a surface layer 5 passes through the surface layer 5 to reach an optical absorption layer 4. Light which reaches the optical absorption layer 4 is absorbed within the optical absorption layer 4, and photoelectrons are generated within the optical absorption layer 4. Photoelectrons diffuse within the optical absorption layer 4, and reach the interface between the optical absorption layer 4 and the surface layer 5. Because the energy band is curved in the vicinity of the interface between the optical absorption layer 4 and surface layer 5, the energy of the photoelectrons is larger than the electron affinity in the surface layer 5, and so photoelectrons are easily ejected to the outside. Here, the optical absorption layer 4 is formed from an Al0.3Ga0.
    Type: Grant
    Filed: May 14, 2003
    Date of Patent: December 14, 2004
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Hirofumi Kan, Minoru Niigaki, Masashi Ohta, Yasufumi Takagi, Shoichi Uchiyama
  • Publication number: 20040135094
    Abstract: A UV sensor 1 comprises a container 5 in which the upper end opening of a metal side tube 2 is sealed with a front plate 3 composed of Kovar glass as an incident light window and the lower end opening is sealed with a base plate 4. The front plate 3 serving as an incident light window constitutes part of the wall of container 5 by sealing the upper end opening of the metal side tube 2. A pin-type photodiode 6 is disposed inside the container 5. The pin-type photodiode 6 comprises a photoabsorption layer 9 formed from InxGa(1-x)N (0<x<1) between an n-type contact layer 8 and a p-type contact layer 10.
    Type: Application
    Filed: November 21, 2003
    Publication date: July 15, 2004
    Applicant: Hamamatsu Photonics K.K.
    Inventors: Minoru Niigaki, Yasufumi Takagi, Kazutoshi Nakajima, Yoshitaka Suzuki, Nobuharu Suzuki