Patents by Inventor Noboru Wakatsuki

Noboru Wakatsuki 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: 20230368991
    Abstract: A DC circuit switching apparatus is connected between an automobile battery and a motor-side circuit and cuts off current that flows in two directions. The DC circuit switching apparatus includes a breaker that cuts off current, a first voltage holding circuit, which is constituted by a first diode and a first capacitor that are connected in series, that is provided in parallel to the breaker and is configured to allow power supply from the automobile battery to the motor-side circuit, and a second voltage holding circuit, which is constituted by a second diode and a second capacitor that are connected in series, that is provided in parallel to the breaker and is configured to allow power supply from the motor-side circuit to the automobile battery.
    Type: Application
    Filed: August 2, 2021
    Publication date: November 16, 2023
    Inventors: Yusuke ISAJI, Manami OKADA, Yuki FUJIMURA, Fumihiro KUZUHARA, Noboru WAKATSUKI
  • Patent number: 8350415
    Abstract: The present invention is a switch circuit equipped with a first switch connected between another end of an inductive load having a one end connected to a one end of a DC power supply and another end of the DC power supply, a capacitor connected between the another end of the inductive load and the another end of the DC power supply and connected in parallel with the first switch, a second switch that connects the another end of the inductive load and the capacitor, a third switch that connects a one end of the capacitor on an inductive load side to the one end of the inductive load so as to be parallel to the second switch, and a control circuit that turns ON the second switch before the first switch is turned OFF and turns OFF the second switch before the first switch is turned ON after being turned OFF.
    Type: Grant
    Filed: November 16, 2010
    Date of Patent: January 8, 2013
    Assignee: Fujitsu Limited
    Inventors: Noboru Wakatsuki, Hideaki Deguchi, Yu Yonezawa, Naoyuki Mishima
  • Publication number: 20110057519
    Abstract: The present invention is a switch circuit equipped with a first switch connected between another end of an inductive load having a one end connected to a one end of a DC power supply and another end of the DC power supply, a capacitor connected between the another end of the inductive load and the another end of the DC power supply and connected in parallel with the first switch, a second switch that connects the another end of the inductive load and the capacitor, a third switch that connects a one end of the capacitor on an inductive load side to the one end of the inductive load so as to be parallel to the second switch, and a control circuit that turns ON the second switch before the first switch is turned OFF and turns OFF the second switch before the first switch is turned ON after being turned OFF.
    Type: Application
    Filed: November 16, 2010
    Publication date: March 10, 2011
    Applicant: TAIYO YUDEN Mobile Technology Co., Ltd
    Inventors: Noboru Wakatsuki, Hideaki Deguchi, Yu Yonezawa, Naoyuki Mishima
  • Patent number: 7786830
    Abstract: A switch includes a movable portion, a first electrode and a second electrode. The movable portion is provided on a substrate and moves with respect to the substrate. The first electrode is provided on the movable portion. The second electrode is able to contact with the first electrode and is fixed to the substrate. f×Ro×C?1.6×10?4 when an operation frequency is represented as “f” (Hz), a transmission impedance is represented as “Ro” (?), and a capacitance in “OFF” state between the first electrode and the second electrode is represented as “C” (F).
    Type: Grant
    Filed: July 23, 2007
    Date of Patent: August 31, 2010
    Assignee: Fujitsu Limited
    Inventors: Noboru Wakatsuki, Yu Yonezawa, Naoyuki Mishima, Tadashi Nakatani, Anh Tuan Nguyen
  • Patent number: 7486488
    Abstract: A load is connected with a power supply. An energizing electric contact and a transient current contact are connected electrically in parallel with each other and can do time-coordinated making and breaking operation. A capacitor is connected in series with the transient current contact. During breaking operation of the energizing contact and keeping making state of the transient current contact, a transient current from the power supply flows into the capacitor and delay voltage increase of the energizing contact using voltage drop at an internal resistance of the power supply and the load.
    Type: Grant
    Filed: September 16, 2004
    Date of Patent: February 3, 2009
    Inventors: Noboru Wakatsuki, Yu Yonezawa
  • Publication number: 20080173524
    Abstract: A switch includes a movable portion, a first electrode and a second electrode. The movable portion is provided on a substrate and moves with respect to the substrate. The first electrode is provided on the movable portion. The second electrode is able to contact with the first electrode and is fixed to the substrate. f×Ro×C?1.6×10?4 when an operation frequency is represented as “f” (Hz), a transmission impedance is represented as “Ro” (?), and a capacitance in “OFF” state between the first electrode and the second electrode is represented as “C” (F).
    Type: Application
    Filed: July 23, 2007
    Publication date: July 24, 2008
    Inventors: Noboru Wakatsuki, Yu Yonezawa, Naoyuki Mishima, Tadashi Nakatani, Anh Tuan Nguyen
  • Publication number: 20070064356
    Abstract: A load is connected with a power supply. An energizing electric contact and a transient current contact are connected electrically in parallel with each other and can do time-coordinated making and breaking operation. A capacitor is connected in series with the transient current contact. During breaking operation of the energizing contact and keeping making state of the transient current contact, a transient current from the power supply flows into the capacitor and delay voltage increase of the energizing contact using voltage drop at an internal resistance of the power supply and the load.
    Type: Application
    Filed: September 16, 2004
    Publication date: March 22, 2007
    Inventors: Noboru Wakatsuki, Yu Yonezawa
  • Patent number: 7129434
    Abstract: An electrical contact device (X1) includes a first contactor with contact portions (C1, C2) and a second contactor with contact portions (C3, C4). The device (X1) also includes an electrical circuit having a branch path (YA) provided by the contact portions (C1, C3) and a branch path (YB) provided by the contact portions (C2, C4). When closed, the branch path (YA) has a smaller resistance, and the branch path (YB) a greater resistance. In a closing operation, the first and second contactors approach each other. Then the contact portion (C1) and the contact portion (C3) contact with each other after the contact portion (C2) and the contact portion (C4) contact with each other. In an opening operation, the first and second contactors separate from each other. Then the contact portion (C1) and the contact portion (C3) separate after the contact portion (C2) and the contact portion (C4) separate.
    Type: Grant
    Filed: November 18, 2005
    Date of Patent: October 31, 2006
    Assignee: Fujitsu Limited
    Inventors: Noboru Wakatsuki, Yu Yonezawa, Yoshio Satoh, Tadashi Nakatani, Tsutomu Miyashita
  • Publication number: 20060128177
    Abstract: An electrical contact device (X1) includes a first contactor with contact portions (C1, C2) and a second contactor with contact portions (C3, C4). The device (X1) also includes an electrical circuit having a branch path (YA) provided by the contact portions (C1, C3) and a branch path (YB) provided by the contact portions (C2, C4). When closed, the branch path (YA) has a smaller resistance, and the branch path (YB) a greater resistance. In a closing operation, the first and second contactors approach each other. Then the contact portion (C1) and the contact portion (C3) contact with each other after the contact portion (C2) and the contact portion (C4) contact with each other. In an opening operation, the first and second contactors separate from each other. Then the contact portion (C1) and the contact portion (C3) separate after the contact portion (C2) and the contact portion (C4) separate.
    Type: Application
    Filed: November 18, 2005
    Publication date: June 15, 2006
    Applicant: FUJITSU LIMITED
    Inventors: Noboru Wakatsuki, Yu Yonezawa, Yoshio Satoh, Tadashi Nakatani, Tsutomu Miyashita
  • Patent number: 7053739
    Abstract: An electrical contacting device includes a plurality of current paths connected in parallel to each other, and a plurality of electrical contact points each having a first contact and a second contact that are mechanically opened and closed. Each current path is provided with a corresponding one of the contact points. For prevention of the occurrence of arc discharge at the contact points, each current path has its electrical characteristics adjusted in order not to allow the passage of the minimum discharge current.
    Type: Grant
    Filed: December 3, 2003
    Date of Patent: May 30, 2006
    Assignee: Fujitsu Limited
    Inventors: Noboru Wakatsuki, Yu Yonezawa, Yoshio Satoh, Tadashi Nakatani, Tsutomu Miyashita
  • Publication number: 20040155737
    Abstract: An electrical contacting device includes a plurality of current paths connected in parallel to each other, and a plurality of electrical contact points each having a first contact and a second contact that are mechanically opened and closed. Each current path is provided with a corresponding one of the contact points. For prevention of the occurrence of arc discharge at the contact points, each current path has its electrical characteristics adjusted in order not to allow the passage of the minimum discharge current.
    Type: Application
    Filed: December 3, 2003
    Publication date: August 12, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Noboru Wakatsuki, Yu Yonezawa, Yoshio Satoh, Tadashi Nakatani, Tsutomu Miyashita
  • Patent number: 6404108
    Abstract: A piezoelectric actuator includes a main driver electrode 4 and a sensor electrode 5. A feedback signal is generated from the sensor electrode 5 in order to eliminate a primary vibration mode due to a primary resonance frequency. The main driver electrode extends to a fixture portion of the actuator, the fixture portion being fitted into a support member 11. The extending portion of the main driver electrode eliminates the electromechanical coupling against a secondary vibration mode due to a second resonance frequency. Features of the piezoelectric actuator suppress the resonance phenomenon, thus improving the response characteristics of the actuator.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: June 11, 2002
    Assignee: Fujitsu Limited
    Inventors: Masanori Yachi, Noboru Wakatsuki, Sumio Yamada
  • Patent number: 6177756
    Abstract: In a piezoelectric gyro, an amplifier 42 receives and amplifies a detected signal from detecting electrodes 19 through 26, and a bandpass filter 43 extracts only a detection-side resonant frequency component from the amplified signal. The extracted resonant frequency component is phase-shifted by a phase-shifting circuit 44, and the resultant signal is passed through a limiting resistor 45 to prepare a constant-current drive signal, and the drive signal is inputted to drive electrodes 11 through 18. As a result, the piezoelectric gyro oscillates self-excitedly at the detection-side resonant frequency. The present invention provides a piezoelectric gyro capable of maintaining a high sensitivity with respect to a change in temperature by improving detection sensitivity.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: January 23, 2001
    Assignee: Fujitsu Limited
    Inventors: Masanori Yachi, Noboru Wakatsuki, Sumio Yamada
  • Patent number: 5861705
    Abstract: A vibratory gyro including a tuning-fork vibrator having a piezoelectric member and a supporting member supporting the tuning-fork vibrator. The tuning-fork vibrator has a driving-side vibration mode and a detection-side vibration mode. The tuning-fork vibrator resonates in the driving-side vibration mode, and the tuning-fork vibrator and the supporting member resonate as a whole in the detection-side vibration mode.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: January 19, 1999
    Assignee: Fujitsu Limited
    Inventors: Noboru Wakatsuki, Masaaki Ono, Sumio Yamada, Kazutugu Kikuchi, Motoi Yamauchi
  • Patent number: 5628099
    Abstract: A method of producing a device including an impedance element provided so as to effect a series resonance, includes a step of connecting connection portions such as terminals or electrodes to be electrically connected in the device, using conductive adhesive resin. This step of connecting connection portions includes a sub-step of applying an alternating current signal which has a frequency lying in close vicinity of a resonant frequency of the device, and which has an enough amplitude to destroy an insulation film parasitically formed in the conductive adhesive resin, to input/output terminals of the device. By executing the sub-step, it is possible to substantially remove a fluctuation in impedance characteristics in dependence on the driving level, and thus to realize a stable operation of the device.
    Type: Grant
    Filed: March 17, 1995
    Date of Patent: May 13, 1997
    Assignee: Fujitsu Limited
    Inventors: Noboru Wakatsuki, Masaaki Ono, Kenji Fukayama, Masanori Yachi
  • Patent number: 5474747
    Abstract: A gas purifier comprising a casing, and two magnetically sensitive reeds arranged in the casing so that one reed extends from one end wall of the casing and the other reed extends from the other end wall of the casing and the free ends of the reeds overlap one above another with a small gap therebetween to form opposing contacts. The magnetically sensitive reeds are magnetically moved by a driving coil so that the contacts are opened and closed like a switch. This operation of the contacts and the contact load coil induces a glow discharge by which a gas is purified by an action of the plasma. A catalyst is carried by the contacts or the casing. Therefore, gas is purified synergically by the action of the plasma and the action of the catalyst. It is also possible to operate the magnetically sensitive reeds, or the like electrodes, by an AC voltage to induce a glow discharge.
    Type: Grant
    Filed: October 22, 1993
    Date of Patent: December 12, 1995
    Assignee: Fujitsu Ltd.
    Inventors: Yuji Hayashi, Noboru Wakatsuki
  • Patent number: 5424602
    Abstract: A piezoelectric transformer comprises a piezoelectric substrate extending in a first direction, a first electrode structure provided on the substrate for exciting an elastic wave propagating through the substrate in the first direction as a result of the piezoelectric transverse effect, and a second electrode structure provided on the substrate for converting the elastic wave to an electric voltage, wherein the first electrode group occupies a first area on the substrate while the second electrode group occupies a second area on the substrate.
    Type: Grant
    Filed: August 25, 1993
    Date of Patent: June 13, 1995
    Assignee: Fujitsu Limited
    Inventors: Masuji Sato, Noboru Wakatsuki, Masanori Ueda, Hiroshi Hasegawa
  • Patent number: 5371430
    Abstract: A piezoelectric transformer comprises a piezoelectric substrate carrying thereon an input electrode structure provided on an upper major surface of the piezoelectric substrate for receiving an a.c. voltage for causing an excitation of an elastic wave in the substrate such that the elastic wave propagates through the substrate in a longitudinal direction, an output electrode structure provided on a lower major surface of the piezoelectric substrate for producing an output a.c. voltage by converting the elastic wave into an electric voltage, wherein the input electrode structure and the output electrode structure have a periodical structure in the longitudinal direction with a pitch corresponding to a wavelength of the elastic wave, and wherein at least one of the first and second electrode structures extend in the longitudinal direction from the first longitudinal edge to the second longitudinal edge substantially continuously.
    Type: Grant
    Filed: May 6, 1993
    Date of Patent: December 6, 1994
    Assignee: Fujitsu Limited
    Inventors: Masuji Sato, Noboru Wakatsuki, Masanori Ueda, Hiroshi Hasegawa
  • Patent number: 5251049
    Abstract: A reflection type liquid crystal apparatus comprising a liquid crystal panel (26) composed of a pair of first and second opposed plates (30, 32) for accommodating a liquid crystal (34) therebetween. A reflecting layer (28) is provided in the inner surface of the second plate, and the first plate is transparent. A common electrode (36) is provided in the first plate, and picture electrodes (38) are located in the second plate. A beam splitter (24) is located in front of the liquid crystal panel (26) for supplying polarized light to the first plate and for selectively transmitting polarized light emerging from the liquid crystal panel (24). The liquid crystal (34) comprises a nematic liquid crystal material having a positive birefringence and arranged in a homogeneous orientation with a constant director (n).
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: October 5, 1993
    Assignee: Fujitsu Limited
    Inventors: Masuji Sato, Akira Tanaka, Noboru Wakatsuki
  • Patent number: 5229680
    Abstract: A piezoelectric transformer includes a substrate of piezoelectric material, preferably a single crystal of LiNbO.sub.3. The substrate is uniformly polarized in a selected direction thereof and vibrated in a direction of the length thereof. An input voltage is applied across both sides of a portion of the substrate in a direction of the thickness thereof and thus excites a vibration by way of piezoelectric effect. Thereby another voltage is caused in the direction of the thickness of the substrate in a portion other than the portion to which the input voltage is applied, and taken out as an output voltage. As a result, it is possible to decrease the output impedance to obtain a large load current and thus fully heighten a step-up ratio of the piezoelectric transformer.
    Type: Grant
    Filed: September 18, 1991
    Date of Patent: July 20, 1993
    Assignees: Fujitsu Limited, Kiyoshi Nakamura
    Inventors: Masuji Sato, Noboru Wakatsuki, Kiyoshi Nakamura, Yoshinori Adachi