Patents by Inventor Nobuyuki Ishitoko

Nobuyuki Ishitoko 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: 6898973
    Abstract: A vibrating gyroscope includes a vibrator which is retained by supporting members at one end of the supporting members and a housing to which the supporting members are fixed at the other end of the supporting members. A rigid reinforcing plate made of a metal is embedded in the housing made of a resin by insert molding. The rigid reinforcing plate is continuous between positions near fixing portions at which the supporting members are fixed to the housing. Therefore, the rigidity of the housing is increased and the vibration of the vibrator is prevented from being transmitted to the outside. In addition, the temperature drift performance is prevented from being degraded.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: May 31, 2005
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Nobuyuki Ishitoko
  • Patent number: 6722622
    Abstract: A compact vibrator support structure has a very high “vibration confinement effect”, and includes a vibrator, vibrator support members, and a vibrator base, which supports the vibrator in midair via the vibrator support members and is made of a material having a specific gravity of about 3.0 or above. Since the high vibration confinement effect of the vibrator support structure reduces leakage of vibration from the vibrator base, the stability of the vibration of the vibrator is greatly improved, thereby increasing the detecting accuracy of angular velocity. This eliminates the need to enlarge the vibrator base or to adhere a weight thereto, resulting in a miniaturized vibrating gyroscope.
    Type: Grant
    Filed: February 26, 2002
    Date of Patent: April 20, 2004
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Akira Mori, Nobuyuki Ishitoko
  • Patent number: 6720714
    Abstract: A vibrating gyroscope includes a vibrator having a node and a support member having a thin flexible portion and an expanded portion which is connected to the thin flexibly portion and has a larger area than the thin flexible portion. The expanded portion of the support member is fixed to the vibrator at the node.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: April 13, 2004
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Ishitoko, Katsumi Fujimoto, Yoshiji Okamoto, Hirofumi Tanaka
  • Patent number: 6680559
    Abstract: A vibration gyroscope includes a vibrator base that supports a vibrator in a hollow portion of the base and includes a frame-shaped portion. Protrusion portions are provided on the inner wall of the frame-shaped portion which defines a stopper that restricts displacement of the vibrator beyond a desired distance. The frame-shaped portion and the protrusion portions are integrally formed by a two-color molding method to define a single unitary member.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: January 20, 2004
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Ishitoko, Katsumi Fujimoto
  • Patent number: 6668649
    Abstract: In order to provide a vibrating gyroscope in which variations in the angular-velocity detection sensitivity are not likely to occur even when sharp temperature changes occur, a vibrator for a vibrating gyroscope includes, on one main surface, a first detection electrode and a second detection electrode, which output a signal containing an angular-velocity signal, wherein a groove having a predetermined depth is provided between the first detection electrode and the second detection electrode. As for a vibrator for a vibrating gyroscope of the present invention, since the difference between the resonance frequency and the anti-resonance frequency in a bending vibration mode in the driving direction becomes closer to the difference between the resonance frequency and the anti-resonance frequency in a bending vibration mode in the detection direction, variations in the angular-velocity detection sensitivity are not likely to occur even when sharp temperature changes are given.
    Type: Grant
    Filed: June 14, 2001
    Date of Patent: December 30, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Ishitoko, Masato Koike
  • Patent number: 6634230
    Abstract: A vibrating gyroscope includes supporting members which are fixed in the vicinity of two node axes n1 and n2 of a bar-shaped vibrator. The supporting members corresponding to node axis n1 extend from the locations at which they are fixed to the vibrator in the widthwise direction of the vibrator, and also include bending portions and a proximity portion. The bending portions bend toward node axis n1. At the proximity portion, the supporting members are in close proximity with each other with a gap therebetween in the vicinity of node axis n1.
    Type: Grant
    Filed: April 18, 2002
    Date of Patent: October 21, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Isao Toyoshima, Akira Mori, Nobuyuki Ishitoko, Takayuki Shimamoto, Akira Kumada, Iku Nagai
  • Patent number: 6590316
    Abstract: The present invention provides a piezoelectric vibrator, in which there is no significant change in the characteristics even when depole occurs due to heat shock and the like. The piezoelectric vibrator includes a first piezoelectric substrate having split electrodes formed on one main surface thereof and a second piezoelectric substrate having a common electrode formed on one main surface thereof. The remaining main surfaces of both piezoelectric substrates are bonded to each other via an intermediate electrode. The material of the first piezoelectric substrate differs from the material of the second piezoelectric substrate. As a result, the difference (longitudinal DF) between a resonant frequency and an anti-resonant frequency in a longitudinal vibration of the piezoelectric vibrator substantially coincides with the difference (transverse DF) between a resonant frequency and an anti-resonant frequency in a transverse vibration thereof.
    Type: Grant
    Filed: December 26, 2001
    Date of Patent: July 8, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Masato Koike, Katsumi Fujimoto, Nobuyuki Ishitoko
  • Publication number: 20030101816
    Abstract: A vibrating gyroscope includes a vibrator which is retained by supporting members at one end of the supporting members and a housing to which the supporting members are fixed at the other end of the supporting members. A rigid reinforcing plate made of a metal is embedded in the housing made of a resin by insert molding. The rigid reinforcing plate is continuous between positions near fixing portions at which the supporting members are fixed to the housing. Therefore, the rigidity of the housing is increased and the vibration of the vibrator is prevented from being transmitted to the outside. In addition, the temperature drift performance is prevented from being degraded.
    Type: Application
    Filed: November 27, 2002
    Publication date: June 5, 2003
    Inventor: Nobuyuki Ishitoko
  • Publication number: 20020166381
    Abstract: A vibrating gyroscope includes supporting members which are fixed in the vicinity of two node axes n1 and n2 of a bar-shaped vibrator. The supporting members corresponding to node axis n1 extend from the locations at which they are fixed to the vibrator in the widthwise direction of the vibrator, and also include bending portions and a proximity portion. The bending portions bend toward node axis n1. At the proximity portion, the supporting members are in close proximity with each other with a gap therebetween in the vicinity of node axis n1.
    Type: Application
    Filed: April 18, 2002
    Publication date: November 14, 2002
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Isao Toyoshima, Akira Mori, Nobuyuki Ishitoko, Takayuki Shimamoto, Akira Kumada, Iku Nagai
  • Publication number: 20020134155
    Abstract: A vibration gyroscope includes a vibrator base that supports a vibrator in a hollow portion of the base and includes a frame-shaped portion. Protrusion portions are provided on the inner wall of the frame-shaped portion which defines a stopper that restricts displacement of the vibrator beyond a desired distance. The frame-shaped portion and the protrusion portions are integrally formed by a two-color molding method to define a single unitary member.
    Type: Application
    Filed: March 26, 2002
    Publication date: September 26, 2002
    Inventors: Nobuyuki Ishitoko, Katsumi Fujimoto
  • Publication number: 20020125795
    Abstract: A compact vibrator support structure has a very high “vibration confinement effect”, and includes a vibrator, vibrator support members, and a vibrator base, which supports the vibrator in midair via the vibrator support members and is made of a material having a specific gravity of about 3.0 or above. Since the high vibration confinement effect of the vibrator support structure reduces leakage of vibration from the vibrator base, the stability of the vibration of the vibrator is greatly improved, thereby increasing the detecting accuracy of angular velocity. This eliminates the need to enlarge the vibrator base or to adhere a weight thereto, resulting in a miniaturized vibrating gyroscope.
    Type: Application
    Filed: February 26, 2002
    Publication date: September 12, 2002
    Inventors: Akira Mori, Nobuyuki Ishitoko
  • Patent number: 6418789
    Abstract: A vibrating gyroscope includes: a support; four vibrating arms, four weights and excitation and detection elements. Each of the four vibrating arms has a first end and a second end in a longitudinal direction, and the four vibrating arms are fixed to the support at the respective first ends in the longitudinal direction such that four vibrating arms are radially arranged in a single plane with the adjacent arms making an angle of about 90 degrees. The four weights are fixed to the support so as to be arranged radially between the respective adjacent vibrating arms. The excitation and detection elements vibrate the vibrating arms under a bending mode within the single plane and output signals generated by the vibration of the vibrating arms.
    Type: Grant
    Filed: February 8, 2000
    Date of Patent: July 16, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Ishitoko, Katsumi Fujimoto
  • Publication number: 20020089260
    Abstract: The present invention provides a piezoelectric vibrator, in which there is no significant change in the characteristics even when depole occurs due to heat shock and the like. The piezoelectric vibrator includes a first piezoelectric substrate having split electrodes formed on one main surface thereof and a second piezoelectric substrate having a common electrode formed on one main surface thereof. The remaining main surfaces of both piezoelectric substrates are bonded to each other via an intermediate electrode. The material of the first piezoelectric substrate differs from the material of the second piezoelectric substrate. As a result, the difference (longitudinal DF) between a resonant frequency and an anti-resonant frequency in a longitudinal vibration of the piezoelectric vibrator substantially coincides with the difference (transverse DF) between a resonant frequency and an anti-resonant frequency in a transverse vibration thereof.
    Type: Application
    Filed: December 26, 2001
    Publication date: July 11, 2002
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Masato Koike, Katsumi Fujimoto, Nobuyuki Ishitoko
  • Publication number: 20020047502
    Abstract: A vibrating gyroscope includes a vibrator having a node and a support member having a thin flexible portion and an expanded portion which is connected to the thin flexibly portion and has a larger area than the thin flexible portion. The expanded portion of the support member is fixed to the vibrator at the node.
    Type: Application
    Filed: September 10, 2001
    Publication date: April 25, 2002
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Ishitoko, Katsumi Fujimoto, Yoshiji Okamoto, Hirofumi Tanaka
  • Publication number: 20020020218
    Abstract: In order to provide a vibrating gyroscope in which variations in the angular-velocity detection sensitivity are not likely to occur even when sharp temperature changes occur, a vibrator for a vibrating gyroscope includes, on one main surface, a first detection electrode and a second detection electrode, which output a signal containing an angular-velocity signal, wherein a groove having a predetermined depth is provided between the first detection electrode and the second detection electrode. As for a vibrator for a vibrating gyroscope of the present invention, since the difference between the resonance frequency and the anti-resonance frequency in a bending vibration mode in the driving direction becomes closer to the difference between the resonance frequency and the anti-resonance frequency in a bending vibration mode in the detection direction, variations in the angular-velocity detection sensitivity are not likely to occur even when sharp temperature changes are given.
    Type: Application
    Filed: June 14, 2001
    Publication date: February 21, 2002
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Ishitoko, Masato Koike
  • Patent number: 6288478
    Abstract: A vibrating gyroscope includes a vibrator having a node and a support member having a thin flexible portion and an expanded portion which is connected to the thin flexibly portion and has a larger area than the thin flexible portion. The expanded portion of the support member is fixed to the vibrator at the node.
    Type: Grant
    Filed: May 28, 1998
    Date of Patent: September 11, 2001
    Assignee: Murata Manufacturing Co. Ltd.
    Inventors: Nobuyuki Ishitoko, Katsumi Fujimoto, Yoshiji Okamoto, Hirofumi Tanaka
  • Patent number: 6281618
    Abstract: A vibrating gyroscope includes two planar vibrating plates arranged to oppose each other. The two vibrating plates vibrate under buckling vibration mode and a second-order bending vibration mode which is degenerated with or close to the buckling vibration mode. The vibrating gyroscope detects Coriolis force by detecting displacements in amplitude balance of the second-order bending vibration modes generated when an angular rotation velocity around an axis parallel to surfaces of the vibrating plates is applied.
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: August 28, 2001
    Assignee: Murata Manufactuirng Co., Ltd.
    Inventors: Nobuyuki Ishitoko, Katsumi Fujimoto
  • Patent number: 6089087
    Abstract: A vibrating gyroscope includes a vibration member in which first and second piezoelectric substrates are joined together. On the outside main surface of the first piezoelectric substrate, a first external electrode divided into six electrode sections is formed. On the outside main surface of the second piezoelectric substrate, a second external electrode is formed. By removing a part of the electrode sections disposed at the center, a capacitance difference C(L)-C(R) between the capacitance C(L) formed between one of the electrode sections disposed at the center and the second external electrode, and the capacitance C(R) formed between another electrode section disposed at the center and the second external electrode is adjusted.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: July 18, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Katsumi Fujimoto, Nobuyuki Ishitoko
  • Patent number: 6058777
    Abstract: A vibrating gyroscope includes a vibrating unit and a driving unit for driving the vibrating unit. The vibrating unit includes at least a pair of piezoelectric bodies stacked and polarized in a stacked direction thereof such that polarizing directions of the piezoelectric bodies are opposed to each other. An interface between the piezoelectric bodies is electrically floating with respect to a reference potential. The driving circuit receives at least one feedback signal from the vibrating unit and outputs to the vibrating unit a driving signal which has substantially the same phase as the feedback signal.
    Type: Grant
    Filed: February 19, 1998
    Date of Patent: May 9, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Katsumi Fujimoto, Kazuhiro Ebara, Nobuyuki Ishitoko
  • Patent number: 6023973
    Abstract: A vibrating gyroscope includes a columnar vibrator, a driver and a detector. The columnar vibrator includes first and second piezoelectric substrates polarized in mutually opposite directions along the thickness directions thereof and stacked with each other. Two divided electrodes are formed on one main surface of the first piezoelectric substrate and spaced in the direction perpendicular to the longitudinal direction of the first piezoelectric substrate, and a common electrode is formed on one main surface of the second piezoelectric substrate. The driver drives the vibrator in the thickness direction of the first and second piezoelectric substrates and is connected between the divided electrodes and the common electrode. The detector detects a displacement caused by bending vibration of the vibrator, and is connected to the divided electrodes.
    Type: Grant
    Filed: September 3, 1998
    Date of Patent: February 15, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Toru Yabe, Katsuhiko Morita, Tetsuo Tatsumi, Nobuyuki Ishitoko, Michihiko Takenaka