Nihon Dempa Kogyo Co., Ltd.

Tomoya Yorita

Shunichi Wakamatsu

Shigenori Watanabe

Takeru Mutoh

Kazuo Akaike

Tsukasa Kobata

Hiroyuki Kukita

Wakako Shinobu

Naoki Onishi

Mitsuaki Koyama

Kaoru Kobayashi

Yasuo Kitayama

Junichiro Yamakawa

Shoichi Tsuchiya

A clock generating circuit includes a dividing unit and a distribution unit. The dividing unit divides a reference clock to generate a divided clock, and the divided clock has a frequency of 1/N times of a frequency of the reference clock, where N is an integer of two or more. The distribution unit distributes the reference clock to a first route and a second route, the first route includes an output terminal that outputs a clock with a frequency identical to the frequency of the reference clock, and the second route includes the dividing unit. The dividing unit includes one or more amplifiers, one or more dividing circuits, and a correction circuit. The correction circuit is disposed between the amplifier and the dividing circuit, and the correction circuit corrects a level of an input clock input to the dividing circuit.

Clock generating circuit and signal processing device

A signal processing circuit includes a clock generating circuit, a divider circuit, a converter, and an amplifier. The clock generating circuit outputs a first clock. The divider circuit divides the first clock to output a second clock having a frequency lower than a frequency of the first clock. The converter converts an input signal into a digital signal based on a first clock output from the clock generating circuit and a second clock output from the divider circuit. The amplifier, disposed between the clock generating circuit and the divider circuit, has a phase variation property opposite to a phase variation property of the divider circuit. The phase variation property of the divider circuit indicates a relationship between a phase variation amount of an output signal with respect to an input signal in the divider circuit and an ambient temperature of the divider circuit.

Signal processing circuit

Providing an OCXO having a highly stabilized output frequency. In an oscillator, which is an OCXO, crystal resonators, oscillator circuits, a temperature detector, and a heater circuit are disposed inside a first container, which is supported in a state of floating inside a second container, while a voltage stabilizer circuit for stabilizing a supply voltage supplied to the heater circuit is disposed apart from the first container inside the second container. Therefore, the supply voltage supplied to the heater circuit is stabilized. The voltage stabilizer circuit is less likely to be affected by heat generation of the heater circuit, thus obtaining a stable oscillation frequency output regardless of the environmental temperature.

Oscillator

To provide an oscillator configured to output a frequency signal accurately reflecting a result of a temperature adjustment by a heater circuit. An oscillator outputs a frequency signal with a frequency preliminarily set. A crystal resonator connected to an oscillator circuit is housed inside a crystal resonator cover. Soldering this crystal resonator cover onto the base plate inside the container disposes the crystal resonator on the base plate inside the container. A heater circuit performs a temperature adjustment inside the container based on a temperature detected by a temperature detector. At this time, the crystal resonator cover that houses the crystal resonator is constituted of a phosphorus deoxidized copper.

An oscillator detects a temperature of an atmosphere where a crystal resonator for an oscillation output is placed using a temperature detector to stabilize the temperature by controlling a temperature of a heater based on a temperature detection value. The device includes a buffer amplifier interposed in a signal path of a control signal generated based on the temperature detection value, a heater disposed such that a collector and an emitter position between a power source unit and a ground and constituted of a transistor having a base connected to an output port of the buffer amplifier, and a first differential amplifier disposed to adjust a gain of the buffer amplifier to cancel voltage fluctuation of the power source unit and amplifying a difference between a voltage corresponding to the supply voltage and a preliminarily set voltage to input to a gain adjustment port of the buffer amplifier.

Oscillator for detecting temperature of atmosphere

A signal processing device includes a plurality of converters, a generator, a distributor, a first line, and a second line. A plurality of converters is configured to convert analog signals to digital signals based on a clock signal to output the digital signals. The generator is configured to generate the clock signal based on a reference signal. The distributor is configured to distribute a generated clock signal to the plurality of converters. The first line passes through only a region assigned to each of the plurality of converters to supply the analog signal to the converter. The second line passes through only the region to supply a distributed clock signal to the converter.

Signal processing device

An oscillator includes a voltage controlled oscillator, a PLL circuit, a crystal unit and an oscillator circuit configured to generate a clock, a digital control circuit, and a clock switching unit. The digital control circuit is configured to set an oscillation parameter of the oscillator circuit, and a parameter of the PLL circuit. The clock switching unit is configured to supply an output signal of the voltage controlled oscillator to the digital control circuit as a clock signal so as to cause the digital control circuit to operate using the clock signal when powered on, and configured to supply an output signal of the oscillator circuit to the digital control circuit as a clock signal after the digital control circuit sets the oscillation parameter of the oscillator circuit. An initial voltage is supplied to the voltage controlled oscillator as a control voltage when the oscillator is powered on.

An oscillator uses a differential signal corresponding to a difference between an oscillation output f1 of a first oscillator circuit and an oscillation output f2 of a second oscillator circuit as a temperature detection value, and outputs a control signal for reducing an influence caused by a temperature characteristic of the oscillation output f1 based on the differential signal. The oscillator includes a switching unit configured to alternately switch between a first state where a first connecting terminal and a second connecting terminal are connected to a storage unit for access of an external computer to the storage unit, and a second state where the first connecting terminal and the second connecting terminal are respectively connected to a first signal path and a second signal path via a frequency reduction unit such that the output signals from the frequency reduction unit are extracted to an external frequency measuring unit.

An oscillation apparatus corrects a setting value for an output frequency based on a detection result of an environmental temperature. The oscillation apparatus includes a first crystal unit, a second crystal unit, an integrated circuit chip, and a container. The first crystal unit includes first excitation electrodes on respective surfaces of a crystal element. The second crystal unit includes second excitation electrodes on respective surfaces of a crystal element. The integrated circuit chip includes a first oscillation circuit, a second oscillation circuit, and a correction unit. The container houses the first crystal unit, the second crystal unit, and the integrated circuit chip. Assuming that distances from a gravity center position of the integrated circuit chip to respective gravity center positions of the first excitation electrodes and the second excitation electrodes in plan view are denoted by D1 and D2, D1/D2 is within a predetermined range close to 1.

Oscillation apparatus

A heater device includes a temperature detector, a heater control circuit, a heater, a voltage supply path, and an overheat prevention circuit. The overheat prevention circuit includes a positive-temperature-coefficient thermistor and a pull-up resistor. The positive-temperature-coefficient thermistor is interposed on the voltage supply path in a position for being heated by the heater. The pull-up resistor that includes: one end connected between the heater and the positive-temperature-coefficient thermistor, and another end connected to a direct current power source. The control voltage to be applied to the heater is restricted to a voltage at a connection point between the positive-temperature-coefficient thermistor and the pull-up resistor when the control voltage from the heater control circuit is abnormally decreased.

Heater device and oscillation apparatus

To provide a sensing device that holds a piezoelectric sensor and a channel forming member placed on the sensor in a closely contacted state while maintaining a shape of space of a passage space formed inside the device. In a sensing devicethat senses a substance to be sensed based on a variation in an oscillation frequency caused by an absorption of the substance to be sensed in an absorption layer provided on a piezoelectric resonatorof a piezoelectric sensor, a holding memberholds the piezoelectric sensorand a channel forming memberthat forms a passage space through which a sample fluid passes on an upper surface side of the sensor, in a vertically stacked state. A cover memberis placed on the channel forming member, and a pressing partwhich is raised/lowered by a first raising/lowering mechanismpresses the cover memberplaced on the channel forming memberdownward with a previously set force.

Sensing device

An oscillator outputs a control signal to suppress an influence caused by temperature characteristic of fbased on a differential signal corresponding to difference between an oscillation output fof a first oscillator circuit and an oscillation output fof a second oscillator circuit treated as a temperature detection value. A switching unit switches between a first state and a second state. The first state is a state where a first connecting end and a second connecting end are connected to a storage unit for access from an external computer to the storage unit. The second state is a state where the first connecting end and the second connecting end are connected to a first signal path and a second signal path such that the respective fand fare retrieved from the first connecting end and the second connecting end to an external frequency measuring unit.

An atmosphere temperature at which a quartz-crystal oscillator and an oscillation circuit are placed is controlled in high accuracy, and an output frequency with high stability is obtained. If oscillation outputs of first and second quartz-crystal oscillators are set to fand f, and oscillation frequencies of the oscillation outputs at a reference temperature are set to fand, respectively, {(f&#x2212;f)/f}&#x2212;{(f&#x2212;f)/f} is calculated by a frequency difference detection unit. A digital value can be obtained by representing this value by 34-bit digital value, corresponding to a temperature. Therefore, this value is treated as a temperature detection value, a difference with a temperature set value is supplied to the loop filter, and the digital value therefrom is converted into a direct-current voltage to control a heater.

Quartz-crystal controlled oscillator

To provide a sensing device having a high processing power and capable of high-accuracy measurement. It is determined whether or not an oscillation frequency is stabilized while a buffer solution is supplied to a quartz-crystal resonator. from a syringe pump. When it is determined that the frequency is stabilized, a second valve. is switched to a sample solution supply mode to supply a sample solution in an injection loop. to the quartz-crystal resonator. An instant at which the sample solution reaches the quartz-crystal resonator. and an instant at which the sample solution finishes passing through the quartz-crystal resonator. are automatically found based on a supply flow rate of the buffer solution, a volume of the injection loop, a volume of a supply channel supplying the sample solution to the quartz-crystal resonator, and an instant at which the second valve. is switched to the sample solution supply mode. An oscillation frequency before the sample solution reaches the quartz-crystal resonator. and an oscillation frequency after the sample solution passes through the quartz-crystal resonator. are found, and a difference between the oscillation frequencies is obtained.

To provide a sensing device and a sensing method that, by a simple method of liquid supply to first and second excitation electrodes, makes it possible to make a first oscillation area adsorb an adsorption substance that adsorbs a substance to be sensed in a sample solution and a blocking substance that prevents the adsorption of a substance and to make the electrode in a second oscillation area adsorb the blocking substance. By the supply of a solution containing the adsorption substance to a first liquid storage spaceA surrounding a first excitation electrodeA, a front surface of the excitation electrodeA is made to adsorb the adsorption substance, and next, by the supply of a solution containing the blocking substance to the first liquid storage spaceA, an area, of the excitation electrodeA, on which the adsorption substance is not adsorbed, is made to adsorb the blocking substance. Further, by the supply of the solution containing the blocking substance to a second liquid storage spaceB separated from the first liquid storage space and surrounding a second excitation electrodeB, a front surface of the second excitation electrodeB is made to adsorb the blocking substance.

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Saitama, Japan

Tomoya Yorita