Patents by Inventor Takashi Tokunaga

Takashi Tokunaga 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: 6971916
    Abstract: An electrical connector comprises a plurality of conductive contacts arranged in a matrix pattern with a space left from one another and a conductive ground member disposed in the space. The ground member comprises a plurality of first ground plates and a plurality of second ground plates combined with the first ground plates. Each of the first ground plates has a plurality of first slit portions. Each of the second ground plates has a plurality of second slit portions. The contacts are received in one-to-one correspondence in a plurality of contact receiving portions defined by combining the first and the second ground plates in a lattice fashion in the state that the second and the first ground plates are inserted in the first and the second slit portions, respectively. Each of the first slit portions has at least one contacting portion contacted with the second ground plate inserted therein.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: December 6, 2005
    Assignee: Japan Aviation Electronics Industry Limited
    Inventor: Takashi Tokunaga
  • Patent number: 6960103
    Abstract: In a connector mounted on a board having a number of through holes, first and second housing are disposed on opposite surfaces of the board. A conductive contact is inserted through the through holes, respectively, and held by the first and the second housings. The contact has first and second contacting portions which are formed at opposite ends thereof and protrude from the first and the second housings, respectively. A first ground is held by the first housing and surrounds the first contacting portion. A second ground is held by the second housing and surrounds the second contacting portion. The first ground has a plurality of terminal portions protruding from the first housing towards the board and arranged in a first staggered pattern. The second ground has a plurality of terminal portions protruding from the second housing towards the board and arranged in a second staggered pattern. The terminal portions are inserted into the through holes, respectively.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: November 1, 2005
    Assignee: Japan Aviation Electronics Industry Limited
    Inventor: Takashi Tokunaga
  • Publication number: 20050215120
    Abstract: An electrical connector comprises a plurality of conductive contacts arranged in a matrix pattern with a space left from one another and a conductive ground member disposed in the space. The ground member comprises a plurality of first ground plates and a plurality of second ground plates combined with the first ground plates. Each of the first ground plates has a plurality of first slit portions. Each of the second ground plates has a plurality of second slit portions. The contacts are received in one-to-one correspondence in a plurality of contact receiving portions defined by combining the first and the second ground plates in a lattice fashion in the state that the second and the first ground plates are inserted in the first and the second slit portions, respectively. Each of the first slit portions has at least one contacting portion contacted with the second ground plate inserted therein.
    Type: Application
    Filed: March 29, 2004
    Publication date: September 29, 2005
    Inventor: Takashi Tokunaga
  • Publication number: 20050215121
    Abstract: In a connector mounted on a board having a number of through holes, first and second housing are disposed on opposite surfaces of the board. A conductive contact is inserted through the through holes, respectively, and held by the first and the second housings. The contact has first and second contacting portions which are formed at opposite ends thereof and protrude from the first and the second housings, respectively. A first ground is held by the first housing and surrounds the first contacting portion. A second ground is held by the second housing and surrounds the second contacting portion. The first ground has a plurality of terminal portions protruding from the first housing towards the board and arranged in a first staggered pattern. The second ground has a plurality of terminal portions protruding from the second housing towards the board and arranged in a second staggered pattern. The terminal portions are inserted into the through holes, respectively.
    Type: Application
    Filed: March 29, 2004
    Publication date: September 29, 2005
    Inventor: Takashi Tokunaga
  • Publication number: 20050185680
    Abstract: A tunable semiconductor laser apparatus with an external resonator includes: a semiconductor laser device having a first end face and a second end face, the second end face being coated with an antireflection film; an optical device for collimating light emitted from the second end face; a reflecting device for reflecting the collimated light, the reflecting device and the first end face constituting an external resonator; a tunable device located between the optical device and the reflecting device; and a driving mechanism for angularly displacing the tunable device to control incidence angle of light onto the tunable device, wherein the driving mechanism includes a micro-machine actuator, thereby shortening the length of the external resonator, yet providing a wide tunable range, reducing the size of the apparatus while achieving excellent mass-productivity.
    Type: Application
    Filed: July 16, 2004
    Publication date: August 25, 2005
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Tokunaga, Yoshio Fujii, Masahiro Tsugai
  • Publication number: 20050174642
    Abstract: An optical element which polarizes light, including: a substrate having a major surface with a first axis, the major surface including concave and convex portions arranged periodically in the direction of the first axis; and a laminated structure disposed on the major surface, in which first and second dielectric layers having different refractive indexes are stacked, one atop the other. The laminated structure includes a low-refraction area that is periodic in the direction of the first axis. The refractive index of the low-refraction area is smaller than the first or second dielectric layer which is adjacent to the low-refraction area.
    Type: Application
    Filed: August 11, 2003
    Publication date: August 11, 2005
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Tokunaga, Yoshio Fujii
  • Publication number: 20050080544
    Abstract: A rollover determination apparatus for vehicles includes a roll-angular-velocity sensor (1) for detecting, as a roll angular velocity, the rotational angular velocity of a vehicle about a longitudinal axis extending lengthwise through the vehicle, an upward-or-downward-acceleration sensor (2) for detecting, as an upward or downward acceleration, an acceleration in an upward or downward direction of the vehicle, an arithmetic processing unit (4a) for carrying out arithmetic processing on both the roll angular velocity detected by the roll-angular-velocity sensor (1) and the upward or downward acceleration detected by the upward-or-downward-acceleration sensor (2), and a rollover occurrence determining unit (4b) for determining whether the vehicle will roll over based on a processing result of the arithmetic processing unit (4a).
    Type: Application
    Filed: September 30, 2004
    Publication date: April 14, 2005
    Inventors: Ryoutarou Suzuki, Satoru Inoue, Masahiro Nakamoto, Takashi Tokunaga
  • Publication number: 20040137219
    Abstract: The throw-away tip has a shape of substantially flat plate, comprising from 1 to 30% by weight of binder phase comprising at least one kind of Co and Ni, and 70 to 90% by weight of carbonitride phase comprising composite metal carbonitride of Ti and one or more kind other than Ti among metals of groups 4a, 5a and 6a of the Periodic Table, wherein the mean grain size of the carbonitride phase is 1.5 &mgr;m or less, while flexural strength test pieces which are cut out of ten throw-away tips including the side face thereof show flexural strength with a Weibull coefficient of 5 or higher. Throw-away tips having fine carbonitride phase structure and high cutting performance can be made with less variance among individual throw-away tips.
    Type: Application
    Filed: December 23, 2003
    Publication date: July 15, 2004
    Applicant: KYOCERA CORPORATION
    Inventor: Takashi Tokunaga
  • Patent number: 5764600
    Abstract: A recording/reproduction method for recording or reproducing information using the magneto-optical recording medium, the magneto-optical recording medium comprising a first magnetic layer comprising a rare earth-transition metal alloy or a ferromagnetic material containing a magnetic transition metal, a second magnetic layer comprising a rare earth-transition metal alloy, a third magnetic layer comprising a rare earth-transition metal alloy, a fourth magnetic layer comprising a rare earth-transition metal alloy, a fifth magnetic layer comprising a rare earth-transition metal alloy, and a sixth magnetic layer comprising a rare earth-transition metal alloy, the second to sixth magnetic layers being stacked in this order on the first magnetic layer, adjacent layers of the second to sixth magnetic layers being coupled by an exchange force thereof.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: June 9, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshio Fujii, Tatsuya Fukami, Takashi Tokunaga, Yoshiyuki Nakaki, Kazuhiko Tsutsumi
  • Patent number: 5679455
    Abstract: This invention relates to a multi-layer magneto-optic recording medium having an information recording layer and an initializing layer that can be overwritten by light modulation, and in which adjacent layers, including auxiliary layers provided for more efficient transfer from the initializing layer to the recording layer, are coupled by an exchange force. This structure enables high-density, high-speed recording of audio information, visual information, and computer data.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 21, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshiyuki Nakaki, Takashi Tokunaga, Tatsuya Fukami, Motohisa Taguchi, Kazuhiko Tsutsumi
  • Patent number: 5638344
    Abstract: A multi-layer magneto-optic recording medium having an information recording layer and an initializing layer that can be overwritten by light modulation, and in which adjacent layers, including auxiliary layers provided for more efficient transfer from the initializing layer to the recording layer, are coupled by an exchange force. This structure enables high-density, high-speed recording of audio information, visual information, and computer data.
    Type: Grant
    Filed: November 29, 1995
    Date of Patent: June 10, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshiyuki Nakaki, Takashi Tokunaga, Tatsuya Fukami, Motohisa Taguchi, Kazuhiko Tsutsumi
  • Patent number: 5593791
    Abstract: A magneto-optical recording medium wherein an initializing layer is covered with a resin layer for dissipating heat from the initializing layer thereby to prevent signal degradation at high recording power and thus excellent in record/reproduce repetition times, and the initializing layer is compositionally modulated thereby to broaden allowable ranges for the recording/reproducing light intensity and for the external magnetic field, besides the composition of a first or a second magnetic layer is controlled thereby to enhance recording sensitivity, and the exchange-coupling force between the first and second magnetic layers or the magnetic field strengthe to reverse the magnetization of the first magnetic layer is controlled thereby to enhance the recording/reproducing characteristics.
    Type: Grant
    Filed: October 16, 1995
    Date of Patent: January 14, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshio Fujii, Takashi Tokunaga, Yoshiyuki Nakaki, Kazuhiko Tsutsumi, Kazuo Hashima, Tatsuya Fukami, Yuji Kawano
  • Patent number: 5547751
    Abstract: A magneto-optical recording medium wherein an initializing layer is covered with a resin layer for dissipating heat from the initializing layer thereby to prevent signal degradation at high recording power and thus excellent in-record/reproduce repetition times, and the initializing layer is compositionally modulated thereby to broaden allowable ranges for the recording/reproducing light intensity and for the external magnetic field, besides the composition of a first or a second magnetic layer is controlled thereby to enhance recording sensitivity, and the exchange-coupling force between the first and second magnetic layers or the magnetic field strengthe to reverse the magnetization of the first magnetic layer is controlled thereby to enhance the recording/reproducing characteristics.
    Type: Grant
    Filed: March 14, 1994
    Date of Patent: August 20, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshio Fujii, Takashi Tokunaga, Yoshiyuki Nakaki, Kazuhiko Tsutsumi, Kazuo Hashima, Tatsuya Fukami, Yuji Kawano
  • Patent number: 5512366
    Abstract: This invention relates to a multi-layer magneto-optic recording medium having an information recording layer and an initializing layer that can be overwritten by light modulation, and in which adjacent layers, including auxiliary layers provided for more efficient transfer from the initializing layer to the recording layer, are coupled by an exchange force. This structure enables high-density, high-speed recording of audio information, visual information, and computer data.
    Type: Grant
    Filed: November 13, 1990
    Date of Patent: April 30, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshiyuki Nakaki, Takashi Tokunaga, Tatsuya Fukami, Motohisa Taguchi, Kazuhiko Tsutsumi
  • Patent number: 5449566
    Abstract: A magneto-optical recording medium allowing both direct overwriting by light power modulation and superresolutive reproduction, and a recording/reproduction method therefor are provided. The magneto-optical recording medium includes six magnetic layers of which adjacent layers are coupled by an exchange force thereof, the first magnetic layer being made of a rare earth-transition metal alloy or a ferromagnetic material containing a magnetic transition metal, the second to sixth magnetic layers being each composed of a rare earth-transition metal alloy. Each of the magnetic layers has a predetermined Curie temperature, and the respective transition metal sub-lattice magnetization directions of the first to third magnetic layers (including the magnetization direction of the first layer) are aligned in one direction at room temperature while at the same time those of the fourth to sixth magnetic layers are aligned in one direction at room temperature.
    Type: Grant
    Filed: August 17, 1993
    Date of Patent: September 12, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshio Fujii, Tatsuya Fukami, Takashi Tokunaga, Yoshiyuki Nakaki, Kazuhiko Tsutsumi
  • Patent number: 5347485
    Abstract: A magnetic thin film memory wherein the memory is composed of magnetic thin films with a layer of a higher coercive force and a layer of a lower coercive force via a nonmagnetic layer laminated repetitively, or magnetic thin films having the easy magnetization axis which lies between the perpendicular and the horizontal directions of the magnetic thin film, and information is recorded on the layer of a lower coercive force, or information is recorded by changing the direction of the magnetization by means of a magnetic field applied by two recording lines which cross the magnetic thin film, thereby to obtain a sufficient amplitude of reproduction signal even when the size of the memory is reduced.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: September 13, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Motohisa Taguchi, Tatsuya Fukami, Kazuo Hashima, Yukari Toide, Yuji Kawano, Yoshio Fujii, Takashi Tokunaga, Yoshiyuki Nakaki, Kazuhiko Tsutsumi, Hiroshi Kobayashi, Yuzou Ohdoi, Shinji Tanabe, Hiroshi Shibata
  • Patent number: 5337305
    Abstract: An information storage system for recording and reproducing information by use of irradiating light on a medium capable of overwriting information is provided. The information storage system is capable of recording information even if the light intensity is varied so as to enhance reliability. The intensity of the light at the time of overwriting is modulated, the more intense light intensity being P.sub.H and the less intense light intensity being P.sub.L. The system includes a mechanism to keep relationship of P.sub.H +.alpha.P.sub.L equal to a constant (.alpha. being a constant depending on the recording conditions). The laser drive circuit is so adjusted that P.sub.H and P.sub.L always provide an optimal condition even if P.sub.H and/or P.sub.L vary. Thus recording can always be performed under optimal conditions to enhance the reliability of the information storage system to expand the power margin of a recording medium and to increase the percentage yield of information medium.
    Type: Grant
    Filed: February 10, 1993
    Date of Patent: August 9, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazuo Hashima, Yuji Kawano, Tatsuya Fukami, Kazuhiko Tsutsumi, Yoshiyuki Nakaki, Takashi Tokunaga, Yoshio Fujii
  • Patent number: 5258237
    Abstract: A megneto-optic recording medium which is comprised of a first, a second, a third and a fourth magnetic layers coupled each other between the adjacent layers by an exchange force, wherein said first through fourth magnetic layers satisfy T.sub.c1 <T.sub.c2, T.sub.c3 <T.sub.c2, T.sub.c1 <T.sub.c4 and T.sub.c3 <T.sub.
    Type: Grant
    Filed: December 27, 1991
    Date of Patent: November 2, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshiyuki Nakaki, Takashi Tokunaga, Tatsuya Fukami, Motohisa Taguchi, Kazuhiko Tsutsumi
  • Patent number: 5216663
    Abstract: This invention relates to a multi-layer magneto-optic recording medium having an information recording layer and an initializing layer that can be overwritten by light modulation, and in which adjacent layers, including auxiliary layers provided for more efficient transfer from the initializing layer to the recording layer, are coupled by an exchange force. This structure enables high-density, high-speed recording of audio information, visual information, and computer data.
    Type: Grant
    Filed: April 20, 1990
    Date of Patent: June 1, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazuhiko Tsutsumi, Tatsuya Fukami, Motohisa Taguchi, Yoshiyuki Nakaki, Takashi Tokunaga
  • Patent number: 5208797
    Abstract: In a magneto-optical recording system for recording information with bits having upward magnetization and having downward magnetization on a recording layer of a magneto-optical recording medium, having four magnetic layers exchange-coupled with each other. A laser beam directed onto the medium is modulated to heat the magneto-optical recording medium to two values, for "High" writing and for "Low" writing. During "High" writing, the first to third layers lose magnetization because their Curie temperatures are exceeded, and the direction of the magnetization of the first layer, which is the recording layer is determined mainly by the magnetostatic coupling from the the fourth layer. During "Low" writing, the first and the third layers lose their magnetization as their Curie temperatures are exceeded, and the direction of the magnetization of the first layer is determined by the exchange coupling from the second layer, which in turn is dependent on the exchange coupling from the fourth layer.
    Type: Grant
    Filed: November 14, 1990
    Date of Patent: May 4, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshiyuki Nakaki, Takashi Tokunaga, Tatsuya Fukami, Motohisa Taguchi, Kazuhiko Tsutsumi