Tuning Fork Patents (Class 73/504.16)
  • Patent number: 6220094
    Abstract: An angular velocity sensor driving circuit includes a driving part for a vibrator, a vibration level detector, a coriolis force detector, a first amplifier for amplifying an output signal of the vibration level detector, a rectifying circuit, a variable gain amplifier, a voltage amplifier, a level judging circuit and switching means. The gain of the voltage amplifier or the gain of a variable gain amplifier is varied by a switching circuit which is controlled by the output signal of a level judging circuit which compares the output signal of the rectifying circuit and a reference voltage. By using the switching circuit rapid start up of the angular velocity sensor can be achieved.
    Type: Grant
    Filed: March 31, 1999
    Date of Patent: April 24, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshihiko Ichinose, Takeshi Uemura, Jiro Terada, Masami Tamura, Kiyohito Nakazawa
  • Patent number: 6220093
    Abstract: An efficiently produced vibratory gyroscope having secure connections is provided. The vibratory gyroscope comprises a vibrator in which driving electrodes, grounding electrodes, and land sections electrically connected to the driving and grounding electrodes are formed. A holding member holds the vibrator, allowing it to vibrate. The vibratory gyroscope also comprises wiring patterns, vibrator-side end sections, a substrate-side end section and a wiring section positioned between the vibrator-side end sections and the substrate-side end section. The vibrator-side end sections are connected to a flexible wiring board comprising land sections electrically connected to the wiring sections and also electrically connected to the land sections of the vibrator and to the substrate-connection end section formed in the circuit-substrate-side end section of the flexible wiring board. A circuit substrate is electrically connected to the wiring patterns.
    Type: Grant
    Filed: February 16, 1999
    Date of Patent: April 24, 2001
    Assignee: Alps Electric Co., Ltd.
    Inventor: Nobuyuki Hirosawa
  • Patent number: 6205857
    Abstract: A tuning-fork sensor is formed with a piezoelectric single crystal and its drive arm 101 is self-excitedly vibrated by an oscillation circuit at a resonance frequency f0 in a predetermined direction. A sensor arm 102 also vibrates in the same direction in synchronization with the drive arm, and forcibly vibrates in the direction orthogonal to the direction of the vibration at the same frequency as f0 by a Coriolis force induced by the rotation. First sensor electrodes of the sensor arm are connected to a ground wire, a positive-input terminal of an operational amplifier forming a sensor circuit is connected to the ground wire, second sensor electrodes and a negative-input terminal are connected to each other, and the negative-input terminal and an output terminal are connected to each other through a feedback resistor 33.
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: March 27, 2001
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Fumio Nakajima
  • Patent number: 6186003
    Abstract: A vibratory gyroscope for detecting a turning angular rate of rotation applied to a vibrator, which vibratory gyroscope has the vibrator provided with a plurality of vibration pieces and a base part having the plurality of vibration pieces connected with it and is composed so as to obtain the turning angular rate on the basis of a detecting vibration excited in the vibrator according to the turning angular rate when giving a driving vibration to at least one of the vibration pieces, and makes the vibrator being supported in a domain where the detecting vibration is smallest in said vibrator, said domain being in the vicinity of the center of gravity of the vibrator.
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: February 13, 2001
    Assignee: NGK Insulators, Ltd.
    Inventors: Takayuki Kikuchi, Shosaku Gouji, Yukihisa Osugi, Takao Soma
  • Patent number: 6182508
    Abstract: An angular rate sensor is provided which measures the angular rate of a moving object such as an automotive vehicle. The angular rate sensor includes an installation base and an oscillator. The oscillator is excited to oscillate in a preselected direction perpendicular to an axis of rotation of the moving object and provides a signal indicative thereof. The installation base is used for installation of the sensor on the moving object and has an improved orientation structure for orienting the oscillator relative to the installation base during installation of the oscillator on the installation base so that the oscillator may oscillate in the preselected direction. The angular rate sensor is disposed within a casing through improved vibration isolators for absorbing unwanted vibrations impinging upon an operation of the sensor.
    Type: Grant
    Filed: December 17, 1997
    Date of Patent: February 6, 2001
    Assignee: Denso Corporation
    Inventors: Yoshinobu Takeuchi, Satoshi Hayashi, Takehiro Watarai, Shinro Oda, Junji Moriwaki, Tomoyuki Kanda, Katuhide Akimoto
  • Patent number: 6170330
    Abstract: An angular velocity sensor including a tuning-fork sensor element made of a material exhibiting piezoelectricity to have two arms formed integrally on a base and electrodes provided on surfaces of the arms. The free end of each arm is formed with an extension projecting outward in the direction of arm vibration. The surfaces of the arms lying in the direction of vibration and the surfaces thereof lying orthogonal to thee surfaces are each provided with a single electrode. When the angular velocity sensor experiences an angular velocity owing to rotation about an axis orthogonal to the plane of the tuning fork, Coriolis forces act on the arms in the same direction as or the opposite direction from that of the vibration at that instant, thereby producing a bending moment. The direction and magnitude of the angular velocity can be determined by detecting the voltages produced by the bending moment.
    Type: Grant
    Filed: May 20, 1999
    Date of Patent: January 9, 2001
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Fumio Nakajima