Patents by Inventor Yoshiro Tomikawa

Yoshiro Tomikawa 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: 7053534
    Abstract: The present invention provides a piezoelectric vibration gyro-sensor utilizing Coriolis force that includes a tuning fork type vibrator in which two rectangular-columnar arms and a base to support the lower end of the arms are integrated; drive electrodes formed on two rectangular-columnar arms; and IDT electrodes of a surface acoustic wave element formed on two arms. Two pairs of the drive electrodes are provided on each rectangular-columnar arm, in which each of the pairs of drive electrodes face each other, and each pair of the drive electrodes are arranged in parallel on the rectangular-columnar arm at a given distance. The IDT electrodes of the surface acoustic wave element are provided between the drive electrodes at the lower end of the rectangular-columnar arms.
    Type: Grant
    Filed: September 3, 2003
    Date of Patent: May 30, 2006
    Assignee: Epson Toyocom Corporation
    Inventors: Yoshiro Tomikawa, Yoshiaki Tanaka
  • Patent number: 6915694
    Abstract: The object of the present invention is to provide an angular velocity sensor that uses Coriolis force with a flatly supported double tuning fork structure that uses an in-plane asymmetrical flexural secondary mode. A large support area is used to provide a high-precision angular velocity sensor with superior resistance to vibration and impact. A double tuning fork gyro-sensor is formed integrally from: two arms; a driver electrode formed on the arms; and a double tuning fork supporting the ends of the arms. Also included are: a detection module connected to the double tuning fork support section; a detection electrode formed on the detection module; and a support securing section for the detection module. When there is rotation, the Coriolis force acting on the arms is transferred to the detection module by way of the double tuning fork support section so that an in-plane asymmetrical flexural secondary vibration takes place.
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: July 12, 2005
    Assignee: Toyo Communication Equipment Co., Ltd.
    Inventors: Yoshiro Tomikawa, Kenji Sato, Atsushi Ono
  • Publication number: 20050056095
    Abstract: The present invention provides an angular velocity sensor that uses Coriolis force with a flatly supported double-ended tuning fork structure that uses an in-plane asymmetrical flexural secondary mode. A large support area is used to provide a high-precision angular velocity sensor with superior resistance to vibration and impact. A double-ended tuning fork gyro-sensor is formed integrally from: two arms; a driver electrode formed on the arms; and a double-ended tuning fork supporting the ends of the arms. Also included are: a detection module connected to the double-ended tuning fork support section; a detection electrode formed on the detection module; and a support securing section for the detection module. When there is rotation, the Coriolis force acting on the arms is transferred to the detection module by way of the double tuning fork support section so that an in-plane asymmetrical flexural secondary vibration takes place.
    Type: Application
    Filed: September 17, 2003
    Publication date: March 17, 2005
    Applicant: Toyo Communication Equipment Co., Ltd.
    Inventors: Yoshiro Tomikawa, Kenji Sato, Atsushi Ono
  • Publication number: 20040046485
    Abstract: The present invention provides a piezoelectric vibration gyro-sensor utilizing Coriolis force that includes a tuning fork type vibrator in which two rectangular-columnar arms and a base to support the lower end of the arms are integrated; drive electrodes formed on two rectangular-columnar arms; and IDT electrodes of a surface acoustic wave element formed on two arms. Two pairs of the drive electrodes are provided on each rectangular-columnar arm, in which each of the pairs of drive electrodes face each other, and each pair of the drive electrodes are arranged in parallel on the rectangular-columnar arm at a given distance. The IDT electrodes of the surface acoustic wave element are provided between the drive electrodes at the lower end of the rectangular-columnar arms.
    Type: Application
    Filed: September 3, 2003
    Publication date: March 11, 2004
    Applicant: Toyo Communication Equipment Co., Ltd.
    Inventors: Yoshiro Tomikawa, Yoshiaki Tanaka
  • Patent number: 6684716
    Abstract: A sensitivity of a Coriolis flowmeter, which is also utilizable as a density meter, composed of a straight conduit through which a fluid to be measured flows, and two counter straight rods that are aligned on both sides of the conduit in parallel, in which one end of the conduit and each one end of the counter rods are fixed to a common support block and another end of the conduit and each another end of the counter rods are fixed to another common support block, is improved by providing to each of the conduit and counter rods a vibration generator for generating vibrations in such manner that the conduit and the counter rods vibrate in opposite phase, and by fixing both support blocks onto a rigid substrate.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: February 3, 2004
    Inventors: Kazumasa Ohnishi, Yoshiro Tomikawa
  • Patent number: 6553845
    Abstract: A highly sensitive Coriolis flowmeter, which is also utilizable as a density meter, is composed of: a substrate having two conduits through which a fluid to be measured flows; a curved tube fixed to the substrate in such manner that one end connects with one conduit and another end connects with another conduit; two curved rods having a curve identical to the curve of the curved tube each of which is fixed to the substrate on each side in parallel with the curve tube with a space; vibrators attached to the tube and rods which generate vibrations in such manner that the tube and rods vibrate in opposite phase; and a sensor for detecting variation of vibration of the tube which is caused by a Coriolis force occurring when a fluid flows through the tube.
    Type: Grant
    Filed: May 21, 2001
    Date of Patent: April 29, 2003
    Inventors: Kazumasa Ohnishi, Yoshiro Tomikawa
  • Publication number: 20020020228
    Abstract: A sensitivity of a Coriolis flowmeter, which is also utilizable as a density meter, composed of a straight conduit through which a fluid to be measured flows, and two counter straight rods that are aligned on both sides of the conduit in parallel, in which one end of the conduit and each one end of the counter rods are fixed to a common support block and another end of the conduit and each another end of the counter rods are fixed to another common support block, is improved by providing to each of the conduit and counter rods a vibration generator for generating vibrations in such manner that the conduit and the counter rods vibrate in opposite phase, and by fixing both support blocks onto a rigid substrate.
    Type: Application
    Filed: May 14, 2001
    Publication date: February 21, 2002
    Inventors: Kazumasa Ohnishi, Yoshiro Tomikawa
  • Publication number: 20010049971
    Abstract: A sensitivity of a Coriolis flowmeter, which is also utilizable as a density meter, composed of a straight conduit through which a fluid to be measured flows, and two counter straight rods that are aligned on both sides of the conduit in parallel, in which one end of the conduit and each one end of the counter rods are fixed to a common support block and another end of the conduit and each another end of the counter rods are fixed to anther common support block, is improved by adjusting each support block to have a length of {fraction (3/10)} or more of the length of the conduit.
    Type: Application
    Filed: April 9, 2001
    Publication date: December 13, 2001
    Inventor: Yoshiro Tomikawa
  • Publication number: 20010045133
    Abstract: A highly sensitive Coriolis flowmeter, which is also utilizable as a density meter, is composed of:
    Type: Application
    Filed: May 21, 2001
    Publication date: November 29, 2001
    Inventors: Kazumasa Ohnishi, Yoshiro Tomikawa
  • Patent number: 6209393
    Abstract: A piezoelectric unit is composed of a plurality of piezoelectric elements. In one embodiment, a first driving electrode is provided over the whole surface of the lower surface of the piezoelectric element. A second driving electrode is provided over the whole surface between the piezoelectric elements. The driving electrodes are connected to a driving signal source. Detection electrodes are provided on the upper surface of the piezoelectric element. At least one of the detection electrodes is connected to one of the output terminals and at least another of the detection electrodes is connected to the other of the output electrodes. One piezoelectric element is polarized upward and another piezoelectric element is polarized downward. A vertical 1st order vibration is driven in a longitudinal direction and a 2nd order bending vibration is detected by the detection electrodes, and a voltage proportional to a coriolis force (rotational angular velocity) is outputted.
    Type: Grant
    Filed: August 26, 1998
    Date of Patent: April 3, 2001
    Assignee: Mitsui Chemicals Inc.
    Inventors: Yoshiro Tomikawa, Kouichi Kanayama, Takeshi Koiso
  • Patent number: 6072266
    Abstract: A vibration actuator has an elastic member formed into a ring shape, an electro-mechanical converting element joined to the elastic member, and a relative moving member which is in press contact with the elastic member. In the vibration actuator, the electro-mechanical converting element generates, upon application of a driving signal, a first vibration mode that vibrates in a direction parallel to a reference plane where the ring shape is formed, and a second vibration mode that vibrates in a direction perpendicular to or substantially perpendicular to the reference plane, and the relative moving member moves relative to the elastic member in one- or two-dimensional directions in the reference plane by the first and second vibration modes.
    Type: Grant
    Filed: December 19, 1995
    Date of Patent: June 6, 2000
    Assignee: Nikon Corporation
    Inventor: Yoshiro Tomikawa
  • Patent number: 5912524
    Abstract: A vibratory gyroscope including an elongated vibrator having a central (neutral) axis (Y-axis), a drive unit for deforming the first direction such that the vibrator vibrates in a first (X) direction, an added mass attached to the vibrator at a position offset from the central axis in a second (Z) direction, and a detector formed on the vibrator. Rotation of the vibratory gyroscope about the second (Z) direction during vibration in the second direction causes Coriolis force to acting on the added mass in a direction parallel to the central axis. Because the added mass is offset from the central axis, a resulting vibration in the second (Z) direction is produced, which is detected by the detector. With this arrangement, the central axis of the vibrator is placed in parallel with the surface of rotation of the rotating system. Thus, rotations about two or three axes in each direction can be detected in such a manner that noise generation is prevented.
    Type: Grant
    Filed: December 23, 1997
    Date of Patent: June 15, 1999
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kazumasa Ohnishi, Akira Satoh, Yoshiro Tomikawa
  • Patent number: 5760528
    Abstract: An ultrasonic actuator is capable of moving one-dimensionally or two-dimensionally on a flat plane, and can easily be assembled in a cylindrical portion such as a lens barrel of a camera. This ultrasonic actuator comprises a frame-like elastic member having an outer form in a regular square, and electro-mechanical converting elements which are joined to frame side portions of the elastic member for generating vibrations in a longitudinal vibration mode and a bending vibration mode in response to a drive signal so as to generate elliptic motion at predetermined positions in the frame side portions by a synthetic motion of the above-mentioned vibrations. The ultrasonic actuator can translate one-dimensionally or two-dimensionally on the flat plane upon application of a driving voltage onto each group of the opposed electro-mechanical converting elements.
    Type: Grant
    Filed: April 2, 1996
    Date of Patent: June 2, 1998
    Assignee: Nikon Corporation
    Inventor: Yoshiro Tomikawa
  • Patent number: 5723935
    Abstract: A vibration driven motor can be driven with high torque at high rotation, and has a simple structure that can be manufactured easily. The motor may comprise a stator in a cylindrical form, a rotor disposed on the end surface of the stator and a pressing member for pressing the rotor on the stator with pressure, the stator may include a first piezoelectric electro-mechanical converting element for generating torsional vibration around the axis of the stator, a second electro-mechanical converting element for generating longitudinal vibration in the axial direction of the stator, and a pair of substantially semi-cylindrical vibration members, and the first or second piezoelectric element may be one or more plate-like members sandwiched by the vibration members of the stator.
    Type: Grant
    Filed: June 10, 1996
    Date of Patent: March 3, 1998
    Assignee: Nikon Corporation
    Inventors: Yoshiro Tomikawa, Tadao Takagi, Mitsuhiro Okazaki, Takatoshi Ashizawa, Isao Sugaya
  • Patent number: 5712598
    Abstract: A driving circuit and a Self-oscillating circuit incorporating a piezoelectric oscillator having one terminal connected to ground. In the driving circuit, an alternating driving power is supplied to a first terminal of the piezoelectric oscillator, and the second terminal of the piezoelectric oscillator is connected to ground. The damping capacitance of the piezoelectric oscillator is effectively canceled by connecting the first terminal to an input of an amplifier, and forming a feedback loop by connecting an output of the amplifier to the input through a electrostatic capacitance whose value is 1/N times the damping capacitance of the piezoelectric oscillator, where the amplifier has a gain of (N+1).
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: January 27, 1998
    Inventor: Yoshiro Tomikawa
  • Patent number: 5708320
    Abstract: A vibratory gyroscope including an elongated vibrator having a central (neutral) axis (Y-axis), a drive unit for deforming the first direction such that the vibrator vibrates in a first (X) direction, an added mass attached to the vibrator at a position offset from the central axis in a second (Z) direction, and a detector formed on the vibrator. Rotation of the vibratory gyroscope about the second (Z) direction during vibration in the second direction causes Coriolis force to acting on the added mass in a direction parallel to the central axis. Because the added mass is offset from the central axis, a resulting vibration in the second (Z) direction is produced, which is detected by the detector. With this arrangement, the central axis of the vibrator is placed in parallel with the surface of rotation of the rotating system. Thus, rotations about two or three axes in each direction can be detected in such a manner that noise generation is prevented.
    Type: Grant
    Filed: October 27, 1995
    Date of Patent: January 13, 1998
    Assignees: Alps Electric Co., Ltd, Yoshiro Tomikawa
    Inventors: Kazumasa Ohnishi, Akira Satoh, Yoshiro Tomikawa
  • Patent number: 5691595
    Abstract: A vibratory gyroscope including a planar elastic vibrator having vibrator piezoelectric material layers formed on both the front and back sides. The vibrator includes a base portion and three parallel elastic pieces extending from the base portion such that the a center elastic piece is located between two side elastic pieces. Electrode layers are formed over the piezoelectric material layers which cause both the side elastic pieces and the center elastic piece to vibrate in a plane, such that the vibrations of the center elastic piece are 180.degree. out-of-phase with the side elastic pieces. When the thus-vibrated vibrator is rotated, the elastic pieces are vibrated in directions parallel to the plane due to the Coriolis force. These deformations are detected as voltage changes across the piezoelectric material layers, and the voltage changes are used to determinate the angular velocity of the vibrator.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: November 25, 1997
    Assignees: Alps Electric Co., Ltd., Yoshiro Tomikawa
    Inventors: Yoshiro Tomikawa, Kazumasa Ohnishi, Akira Satoh
  • Patent number: 5675296
    Abstract: A drive voltage is supplied to a piezoelectric oscillator from an A.C. drive power source. Attached to an electrode of the piezoelectric oscillator is a loop circuit in which an amplifier having a (N+1) voltage amplification factor and an electrostatic capacitor are connected in series. When the electrostatic capacity is set to 1/N of a damping capacity of the piezoelectric oscillator, the current flowing through the damping capacity is replaced and shared by current from the electrostatic capacity, thus the drive current will not be consumed by the damping capacity. Therefore, a condition where the damping capacity is minimized depends on a capacity value of the electrostatic capacity and amplification factor of the amplifier only and does not depend on the frequency.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: October 7, 1997
    Inventor: Yoshiro Tomikawa
  • Patent number: 5451828
    Abstract: A vibratory gyroscope, including a vibrator, which has three elastic arms separated by two slits, a driving means for generating vibration in at least one elastic arm, and a detecting means for detecting a component of vibration in a direction, which intersects with the direction of the vibration generated in an elastic arm due to Coriolis force when the vibrator rotates.
    Type: Grant
    Filed: July 22, 1994
    Date of Patent: September 19, 1995
    Assignees: Alps Electric Co., Ltd., Yoshiro Tomikawa
    Inventors: Yoshiro Tomikawa, Kazumasa Ohnishi
  • Patent number: 5414497
    Abstract: A developing apparatus includes a guide member for guiding toner toward an image bearing member bearing an electrostatic image thereon, the guide member having a first end and a second end, a vibration generating device for applying an ultrasonic oscillation to the guide member proximate one of the first end and the second end of the guide member, and a vibration absorbing device for absorbing the ultrasonic oscillation in the guide member at the other one of the first end and the second end, wherein toner is conveyed on the guide member in a direction from the absorbing device to the vibration applying device. In one aspect, the toner is a magnetic toner, and a magnetic field is generated on the guide member at a position opposite a surface for guiding the toner.
    Type: Grant
    Filed: October 21, 1993
    Date of Patent: May 9, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroaki Tsuchiya, Keishi Ohsawa, Yuji Sakemi, Kenichiro Waki, Nobuyuki Ito, Takehiro Takano, Yoshiro Tomikawa