Nihon Dempa Kogyo Co., Ltd.

Mitsuaki Koyama

Takeru Mutoh

Shunichi Wakamatsu

Hiroki Iwai

Shigenori Watanabe

Ryoichi Ichikawa

Kazuo Akaike

Shinichi Sato

Wakako Shinobu

Tsukasa Kobata

Tomoya Yorita

Tsuyoshi Shiobara

Takeshi Matsumoto

Yoshiaki Amano

Shigeru Obara

Manabu Ishikawa

Junichiro Yamakawa

Shigetaka Kaga

Kietsu Saito

Sachiko Takehana

Tadashi Tamiya

Keisuke Miyashita

Chiaki Kato

Toshihiko Kagami

Shuzi Osawa

It is possible to determine the presence of bacteria in a sample solution in a shorter period of time without changing a conventional incubating method. Bacteria in a sample solution are incubated in, for example, a sterilized agar mediumhaving a layer thickness of 0.1 &#x3bc;m to 1 &#x3bc;m formed on an electrode of a crystal resonator, and an oscillation frequency is measured. When the bacteria proliferate, the mass of the entire crystal resonatorincreases, and the oscillation frequency decreases. Therefore, by monitoring presence of such a change over time, presence of bacteria in the sample solution can be determined quickly.

Method for detecting microorganisms and microorganism detecting apparatus

A technique for detecting external force applied to a piezoelectric plate is provided. A crystal plate is cantilever-supported in a container. Excitation electrodes are formed on an upper face and lower face, respectively, of the crystal plate. A movable electrode is formed on the lower face side. A fixed electrode is provided on a bottom portion of the container facing the movable electrode. The excitation electrode on the upper face side and the fixed electrode are connected to an oscillation circuit. When the crystal plate bends by external force applied, capacitance between. A direction of the movable electrode along a length direction of the crystal plate is set to 30&#xb0; to 60&#xb0;, relative to a face orthogonal to an intended direction of the external force. The movable electrode and fixed electrode changes, and this capacitance change and a deformation of the crystal circuit.

External force detecting method and external force detecting device

A device is provided for a detecting external force applied to piezoelectric piece. A crystal piece is cantilever-supported in a container. Excitation electrodes are formed on an upper face and lower face, respectively. A movable electrode, connected via a lead-out electrode to the excitation electrode, is formed on the lower face side at a front end of the crystal piece. A fixed electrode is provided on a bottom portion of the container to face this movable electrode. The excitation electrode on the upper face side and the fixed electrode are connected to an oscillation circuit. When the crystal piece bends in response to an applied external force, capacitance between the movable electrode and fixed electrode, changes. This capacitance change results in a corresponding change in oscillation frequency of the crystal piece.

External force detecting device and external force detecting sensor

An acceleration measuring apparatus that can easily detect acceleration with high accuracy is provided. In the apparatus, positional displacement of a swingable pendulum member is detected, feedback control is performed to maintain the pendulum member in a stationary state using an actuator, and acceleration is measured by measuring the output of the actuator at this time. A movable electrode is provided to the pendulum member, and a loop is formed in which a fixed electrode provided to oppose the movable electrode, and an oscillating circuit, a crystal unit, and the movable electrode are electrically connected in series. By measuring an oscillating frequency of the oscillating circuit at this time, a change in the size of a variable capacitance formed between the movable electrode and the fixed electrode is detected, and thereby the positional displacement of the pendulum member is detected.

Acceleration measuring apparatus

In an external force detection apparatus, a crystal plate is cantilevered within a container. Excitation electrodes are formed on the top surface and the bottom surface of the crystal plate. A movable electrode is formed on a distal end on the bottom surface of the crystal plate and is connected to the excitation electrode on the bottom surface via an extraction electrode. A fixed electrode is provided on the bottom of the container to oppose the movable electrode. The excitation electrode on the top surface and the fixed electrode are connected to an oscillating circuit. When an external force acts on the crystal plate to bend it, the capacitance between the movable electrode and the fixed electrode changes, and this capacitance change is captured as a change in the oscillating frequency of the crystal plate.

External force detection apparatus and external force detection sensor

A crystal resonator comprises a first vibrating region provided on a crystal wafer, a second vibrating region provided on the crystal wafer, the second vibrating region having a different thickness and positive/negative orientation of the X-axis from those of the first vibrating region, and excitation electrodes which are provided respectively on the first vibrating region and the second vibrating region for causing the vibrating regions to vibrate independently. Frequencies that change by different amounts from each other relative to a temperature change can be retrieved from one vibrating region and the other vibrating region. Thus, based on an oscillating frequency of the vibrating region in which a clear frequency change occurs relative to the temperature, the oscillating frequency of the other vibrating region can be controlled. Thereby, increases in the complexity of the crystal oscillator can be suppressed.

Crystal resonator and crystal oscillator

Method of detecting microorganisms and microorganism detecting apparatus

A brake mechanism is constituted to have: an electromotive actuator which suppresses a rotation of a disk by moving a first pad toward a second pad to sandwich and press the disk between the first pad and the second pad; a pressing force setting section outputting a set signal to set a pressing force of the pad to the disk; a plurality of piezoelectric elements provided at different places from each other in the first pad or the second pad, the plurality of piezoelectric elements detecting a stress of the pad; a signal processing part which processes electric signals obtained from the plurality of piezoelectric elements and generates a detection signal of a pressing force, the detection signal corresponding to a pressing force of the pad to the disk; and a computing part which obtains a deviation between the set signal and the detection signal, computes an operation signal of the electromotive actuator based on the deviation, and then outputs the operation signal.

Brake mechanism, transport apparatus and industrial apparatus

Provided is a device capable of easily and accurately detecting a vibration period when, for example, an earthquake occurs. When a quartz-crystal plate bends upon application of a force, capacitance between a movable electrode provided at its tip portion and a fixed electrode provided on a vessel to face the movable electrode changes, so that an oscillation frequency of the quartz-crystal plate changes according to this capacitance. Therefore, when the vessel is vibrated, there appear a first state where the quartz-crystal plate ends to approach the fixed electrode and a second state where the quartz-crystal plate is in an original state or bends to be apart from the fixed electrode. Accordingly, an oscillation frequency corresponding to the first state and corresponding to the second state alternately appear, and therefore, it is possible to find the period (frequency) of the vibration.

Vibration detecting device

An oscillator includes a nominal frequency output unit, a frequency adjustment amount output unit, a gain output unit, a multiplier, and an adder. The nominal frequency output unit is configured to output a first digital value corresponding to the nominal frequency. The frequency adjustment amount output unit is configured to output a second digital value corresponding to a rate of frequency in order to set a frequency adjustment amount with respect to the nominal frequency using the rate of frequency. The gain output unit is configured to output a third digital value corresponding to a gain to be multiplied by the second digital value. The multiplier is configured to multiply the second digital value by the third digital value, thus outputting a fourth digital value. The adder adds the first digital value and the fourth digital value to output the added result as a setting signal of frequency.

Oscillator with frequency adjustment

To provide a quartz sensor capable of detecting a sensing target with high sensitivity also in measurement in a liquid phase in which a difference in Q values at the time of measurement in the liquid phase and in a vapor phase is small. In a quartz sensorincluding an AT-cut quartz platehaving a capture layer (absorbing layer)formed on one surface (XZ' surface) thereof and detecting a sensing target based on an amount of change in a frequency of a quartz resonatorcaused when the sensing target is absorbed by the capture layer, there are formed electrodesfor oscillating the quartz plateon end faces (XY&#x2032; surfaces) mutually opposite in a Z&#x2032; direction of the surface of the quartz resonatoron which the capture layeris formed (XZ&#x2032; surface).

Quartz sensor and sensing device

A sensing instrument using a piezoelectric resonator changes natural frequency when coming into contact with a liquid to adsorb a substance to be sensed in the liquid. The sensing instrument includes an oscillator circuit supplying a piezoelectric resonator with oscillation driving power for oscillating the piezoelectric resonator so as to set a driving current to 0.3 mA or less. A measuring unit measures a concentration of the substance to be sensed based on an oscillation output of the oscillator circuit. Self-heating of the piezoelectric resonator is suppressed. Consequently, a change of the oscillation frequency of the piezoelectric oscillator is suppressed, which as a result enables accurate detection of a variation of the frequency due to the adsorption of the substance to be sensed.

Sensing instrument

Objects of the present invention is to provide a piezoelectric resonator having high frequency stability and a sensing sensor using the piezoelectric resonator. In the present invention, a piezoelectric resonator 1 has: a first oscillation area 105 which is provided in a piezoelectric piece 100 and from which a first oscillation frequency is taken out; a second oscillation area which is provided in an area 105 different from the first oscillation area 106 via an elastic boundary area 107 and from which a second oscillation frequency is taken out; and excitation electrodes 101 to 103 provided on one surface side and another surface side of the oscillation areas 105, 106 across the piezoelectric piece 100, and a frequency difference between the first oscillation frequency and the second oscillation frequency is not less than 0.2% nor greater than 2.2% of these oscillation frequencies.

Piezoelectric resonator and sensing sensor

To shorten the time required for an oscillation frequency to stabilize in a sensing device sensing a substance to be sensed by using the fact that a natural frequency of a piezoelectric resonator changes when the substance to be sensed is adsorbed by an adsorption layer formed on the piezoelectric resonator. A sensing device includes: an oscillator circuitoscillating a quartz-crystal resonator; and an intense excitation circuit that is formed by the oscillator circuitincluding a series circuit of a resistorand a third transistorof PNP type and that intensely excites the quartz-crystal resonatorconnected to the oscillator circuitfor a period of time preset by a one-shot circuitby supplying the quartz-crystal resonatorwith high power equal to or more than twice regular power supplied at the time of the measurement of the substance to be sensed, to stabilize the oscillation of the quartz-crystal resonator. When the connection of the quartz-crystal resonatoris detected, the one-shot circuitbrings the oscillator circuitinto an aging state and the high power is supplied to the quartz-crystal resonatorto intensely excite the quartz-crystal resonator, thereby eliminating the distortion and stress of a quartz-crystal plate

Sensing device

There is provided a temperature compensated piezoelectric oscillator which excels in frequency stability and has a good electronic noise characteristic, and with which a circuit can be structured simply. An auxiliary oscillator unitsharing a crystal substratewith a main oscillator unitoutputting a set frequency fto an outside is used as a temperature detecting unitdetecting a temperature T for obtaining a compensation voltage &#x394;V in a temperature compensated piezoelectric oscillator (TCXO), and electrodesof the main oscillator unitand the auxiliary oscillator unitare provided separately on the crystal substrate. For example, a fundamental wave and an overtone are used or a thickness shear vibration and a contour shear vibration are used in the main oscillator unitand the auxiliary oscillator unit, respectively.

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Sayama, Japan

Mitsuaki Koyama