Other

Alps Electric Co., Ltd.

Nikon Corporation

Canon Kabushiki Kaisha

Fujitsu Corporation

Mitsui Chemicals, Inc.

Epson Toyocom Corporation

Toyo Communication Equipment Co., Ltd.

Yoshiro Tomikawa

Kazumasa Ohnishi

Akira Satoh

Yuji Sakemi

Hiroaki Tsuchiya

Kenichiro Waki

Nobuyuki Ito

Keishi Ohsawa

Takehiro Takano

Tadao Takagi

Takatoshi Ashizawa

Isao Sugaya

Kenji Sato

Yoshiaki Tanaka

Mitsuhiro Okazaki

Shinichi Yamamoto

Takashi Gounji

Takeshi Koiso

Kouichi Kanayama

Teruo Kawatsu

Masashi Konno

Atsushi Ono

Toshiharu Ogasawara

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.

Piezoelectric vibration gyro-sensor

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.

Double-ended tuning fork vibratory gyro-sensor

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.

Coriolis flowmeter

Coriolis flowmeter utilizing three-forked plate vibrator mode

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 1,order vibration is driven in a longitudinal direction and a 2,order bending vibration is detected by the detection electrodes, and a voltage proportional to a coriolis force (rotational angular velocity) is outputted. With this construction, a vibration gyroscope having a reduced thickness and width can be produced.

Vibration gyroscope

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.

Vibration actuator

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.

Vibratory gyroscope

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.

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.

Vibration driven motor

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). In the self-oscillating circuit, a frequency selection circuit is provided which includes a positive feedback circuit connected between an output and a non-inverting input of an amplifier, and an electrostatic converter including a first terminal connected to the positive feedback circuit, and a second terminal connected to ground. The positive feedback circuit includes an electrostatic capacitance and a resistor selected such that a self-oscillation frequency of the self-oscillation circuit is determined by said frequency selection circuit.

Driving apparatus for electrostatic converting means

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. The outside edges of the side elastic pieces are offset from an outer edge of the base section to prevent twisting stress, thereby allowing more precise vibration detection.

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.

Capacitive-component reducing circuit in electrostatic-type transducer

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.

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.

Growing community of inventors

Yonezawa, Japan

Yoshiro Tomikawa