Murata Manufacturing Co., Ltd.

Keiichi Okano

Takeshi Nakamura

Tohru Kasanami

Yoshiko Morishita

Katsumi Fujimoto

Masato Koike

Hideaki Sugibayashi

Hironari Yamamoto

Kohichi Murohashi

Yoshiki Morishita

Kohichi c/o Texas Inst Japan Limited Murohashi

Katsumi c/o Intel Prop Dpt Fujimoto

A vibrating gyroscope includes two input buffers each arranged to input voltage signals appearing at respective detection electrodes of one of two piezoelectric vibrators. An adding circuit adds up output voltages of the respective input buffers. An amplitude control circuit automatically controls a loop gain such that an output voltage of the adding circuit has a substantially constant amplitude. A phase-shift circuit controls the phase of a drive voltage supplied to the piezoelectric vibrators such that the piezoelectric vibrators oscillate by positive feedback. Two differential amplifier circuits each amplify a voltage difference corresponding to an angular velocity about an axis. Two synchronous detection circuits each perform detection using a synchronizing signal generated from an oscillation signal, and detect a voltage signal corresponding to the angular velocity.

Vibrating gyroscope

A piezoelectric vibrator of a vibration gyro vibrates in response to a drive voltage Vinput into a drive electrode, and when deformed by a Coriolis force, generates detection voltages V, between which a potential difference corresponds to the deformation, at detection electrodes. An AGC circuit outputs a drive voltage Vwhile performing automatic gain control so that the detection voltages Vhave a given amplitude. A phase inversion circuit and a BTL amplifier circuit output a BTL voltage V, whose phase is opposite to the detection voltage Vand whose amplitude has been increased, to the detection electrodes via detection resistances. The AGC circuit reduces the detection voltages Vin order to prevent the drive voltage Vfrom exceeding a design upper limit value V'.

Vibrating gyro

A vibrator that produces bending vibration with both ends unsupported is mounted on one principal surface of a mounting board, and a driving-and-detecting circuit component is also mounted to cross over an antinode center line of bending vibration of the mounting board due to resonance. The original self-resonance frequency of bending vibration of the mounting board itself is lower than the frequency of bending vibration of the vibrator. The modified self-resonance frequency of bending vibration of the mounting board when the vibrator and the driving-and-detecting circuit component are mounted thereon is higher than the original self-resonance frequency, and does not coincide with the frequency of bending vibration of the vibrator.

Vibrating gyroscope and electronic device using the same

A vibration gyro which is a sensor circuit module includes a packaging substrate, a vibrator mounted on the substrate, a chip type semiconductor element mounted by flip-chip bonding, a chip element, and a cover. The portion of the end surfaces of the packaging substrate in which no through-hole terminals are formed is coated with a light-shielding coating material which is a light-transmission-stopping member. Preferably, the color of the light-shielding coating material is as dark as possible, and is black, if possible.

Sensor circuit module and electronic device using the same

An angular velocity sensor includes a vibrator. A differential amplifier circuit outputs a differential signal including a Coriolis component from the vibrator. The differential signal is converted into a digital signal by an A/D converter. A Hilbert transformer shifts the differential signal by &pgr;/2. Two multipliers squares the original differential signal and the &pgr;/2-phase-shifted differential signal, respectively, and an adder computes the sum of the squares. A square root circuit computes the square root of the sum and outputs a magnitude signal proportional to Coriolis force.

Angular velocity sensor

A vibrating gyroscope includes a vibrating body and at least one driving member located on the vibrating body. The at least one driving member is arranged vibrate the vibrating body in a direction that is substantially perpendicular to an axis of the vibrating body. At least two detection members are are arranged so as to be spaced from each other and operatively connected to the vibrating body. The at least two detection members are located on opposite sides of a plane which includes the axis and a vibrating direction of the vibrating body such that the at least two detection members detect vibration of the vibrating body at substantially the same amount and detect at a different amount a Coriolis force generated by a rotational angular velocity applied to the vibrating body.. A differential amplifier circuit is connected to the at least two detection members and is arranged receive signals from the at least two detection members and outputs a signal indicative of the Coriolis force by canceling detection signals received from the vibration body at the least two detection members.

Vibrator and vibratory gyroscope using the same

A method of forming a vibrating gyroscope includes the steps of providing a vibrating body and disposing at least one driving member on the vibrating body so that the at least one driving member is arranged to generate vibration in the vibrating body in a vibrating direction that is substantially perpendicular to an axis of the vibrating body. Then, at least two detection members are disposed on the vibrating body such that the at least two detection members are spaced from each other, located on opposite sides of a plane including the axis and the vibrating direction of the vibrating body, arranged to detect a rotational angular velocity applied to the vibrating body and arranged in a non-parallel relationship relative to each other and in a non-parallel relationship relative to the at least one driving member.

Vibrator including piezoelectric electrodes of detectors arranged to be

A vibrating gyroscope comprising includes a vibrating body. At least one driving member is located on the vibrating body and vibrates the vibrating body in a vibrating direction that is substantially perpendicular to an axis of said vibrating body. At least two detection members are located so as to be spaced from each other on the vibrating body and located on opposite sides of a plane including the axis and the vibrating direction of the vibrating body. The at least one driving member is arranged in a non-parallel relationship relative to each of the at least two detection members. The at least two detection members are arranged to detect a rotational angular velocity applied to the vibrating body and the at least two detection members are arranged in a non-parallel relationship relative to each other.

Vibratory gyroscope including piezoelectric electrodes or detectors

The vibrator includes, for example, a triangular prism shaped vibrating body. On each of three side faces of the vibrating body, piezoelectric elements are formed respectively. The vibrating body makes bending vibration by giving a driving signal to one or two piezoelectric elements. The vibrator is used in a vibratory gyroscope. In this case, for example, one piezoelectric element is used for vibrating the vibrator. When a rotating force is applied to the vibratory gyroscope, a Coriolis force is exerted to produce output voltages on the remaining two piezoelectric elements corresponding to the rotational angular velocity.

Vibrator including piezoelectric electrodes or detectors arranged to be

The vibrator includes for example, a triangular prism shaped vibrating body. On each of three side faces of the vibrating body, piezoelectric elements are formed respectively. The vibrating body makes bending vibration by giving a driving signal to one or two piezoelectric elements. The vibrator is used in a vibratory gyroscope. In this case, for example, one piezoelectric element is used for vibrating the vibrator. When a rotating force is applied to the vibratory gyroscope, a Coriolis force is exerted to produce output voltages on the remaining two piezoelectric elements corresponding to the rotational angular velocity.

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Nagaokakyo, Japan

Keiichi Okano