Abstract: An optical fiber laser, according to the present invention, has an optical fiber including a core to which a rare earth element is added and a clad disposed around the core, and also has an excitation light source for emitting excitation light incident on a side of the optical fiber. The optical fiber has a corrugated shape on the outer circumference of the clad along the longitudinal direction thereof; and the optical fiber is wound in a spiral form and is bundled in such a way that adjacent sides of the clad are brought into contact with one another.

Abstract: An AD converter comprising: a delta-sigma-modulation circuit to output an analog signal from a bridge circuit as a quantized signal; a switch circuit to switch between a first state, where a first level voltage is applied to one terminal of the bridge circuit and a second level voltage different in level from the first level voltage is applied to the other terminal thereof, and a second state, where voltages opposite in level to those in the first state are applied thereto, based on a logic level of a control signal; and an up-down counter to increase a count value based on a rate of the quantized signal being one logic level, during a predetermined period, in the first state, and decrease the count value based on the rate, during the predetermined period, in the second state, the count value representing a digital signal according to the physical quantity.

Abstract: The accuracy of a measurement value obtained by a tire pressure detection device is lowered by a centrifugal force and an inertial force during travel. A pressure sensor (30) displaces a diaphragm (20) in its vertical direction (32) according to the pressure. The pressure sensor (30) is arranged in a tire (2) with the vertical direction (32) directed to a direction parallel to a rotation axis (34) instead of the tire circumferential direction or radial direction. The pressure sensor (30) is mounted onto a substrate with the vertical direction (32) of its diaphragm (20) directed in parallel to the substrate surface and the substrate is bonded to a tread portion of the tire (2) and a wheel rim portion while adjusting the vertical direction (32) of the diaphragm (20) with the direction of the rotation axis (34).

Abstract: A temperature sensor circuit includes a band-gap reference voltage circuit. The resistor and diode-connected bipolar transistor of the band-gap reference voltage circuit are separated into a transistor-resistor series circuit and a transistor-diode series circuit. The transistor-resistor series circuit is configured such that an emitter of the bipolar transistor Q21 is connected to a power supply voltage terminal VCC, a collector thereof is grounded via the resistor R2. The transistor-diode series circuit is configured such that an emitter of the bipolar transistor Q20 is connected to the power supply voltage terminal VCC, a collector thereof is connected to a collector of the diode-connected bipolar transistor Q19, and an emitter of the diode-connected bipolar transistor is grounded. A voltage divider circuit 5 having a plurality of output terminals is connected to the transistor-resistor series circuit and the transistor-diode series circuit via first and second buffer circuits 3 and 4, respectively.

Abstract: According to a preferred embodiment of the present invention, a low-voltage operation constant-voltage circuit includes a band-gap reference voltage circuit including a resistor-diode series circuit as a main component. A resistor and a diode-connected bipolar transistor are connected in series to create a constant current. It also includes an output circuit connected in parallel to the resistor-diode series circuit and formed so that the same constant current as the current flowing through the resistor-diode series circuit flows. The output circuit includes a diode-connected MOS transistor, and is configured to cancel the positive temperature coefficient of the current flowing through the output circuit by the MOS transistor. With this, a stable output low-voltage of, e.g., about 0.6 V, excellent in temperature characteristics can be obtained regardless of the ambient temperature changes.

Abstract: A communication system is provided comprising an environment-side electrode and a living body-side electrode sandwiching an insulating layer and electrically insulated from each other, a grounding electrode which is electrically connected to the environment-side electrode, and a reception amplifier which amplifies a potential difference between the environment-side electrode and the living body-side electrode, wherein the grounding electrode has a side surface section which extends along a vertical direction.

Abstract: A communication system is provided comprising a living body-side electrode which primarily capacitively couples with a living body, an environment-side electrode which primarily capacitively couples with an external environment, and a circuit board on which a circuit which processes a signal which is output from at least one of the living body-side electrode and the environment-side electrode is mounted, wherein the circuit board is not placed between the living body-side electrode and the environment-side electrode.

Abstract: With a delta sigma modulator of this invention, a plurality of clocks required to control a switching circuit can be easily generated and correlation among phases of the plurality of clocks can be automatically maintained while a frequency of the clocks is modified. A ring oscillator is formed of three delay circuits provided with differential amplifiers in the delta sigma modulator. A clock producing circuit produces the plurality of clocks to control the switching circuit by delaying three-phase clocks outputted from the ring oscillator. All the tail currents Ic in the differential amplifiers in the delay circuits in the ring oscillator and the tail currents Ic in the differential amplifiers in the delay circuits in the clock producing circuit are proportional to each other.

Abstract: A tire pressure measuring system (TPMS) for transmitting pressure information from a tire to a vehicle body has a complicated structure when a plurality kinds of transmission data exist. A sensor unit receives a transmission electromagnetic field from a sensor control unit, and rectify-detects the received field. The counter of the sensor unit determines a rotation cycle of a tire, based on the signal obtained by the rectification detection, then switches the switch in conjunction with the rotation cycle, and sequentially sends the plurality of transmission data items for every tire rotation.

Abstract: An AD converter comprising: a delta-sigma-modulation circuit to output an analog signal from a bridge circuit as a quantized signal; a switch circuit to switch between a first state, where a first level voltage is applied to one terminal of the bridge circuit and a second level voltage different in level from the first level voltage is applied to the other terminal thereof, and a second state, where voltages opposite in level to those in the first state are applied thereto, based on a logic level of a control signal; and an up-down counter to increase a count value based on a rate of the quantized signal being one logic level, during a predetermined period, in the first state, and decrease the count value based on the rate, during the predetermined period, in the second state, the count value representing a digital signal according to the physical quantity.

Abstract: An optical fiber laser, according to the present invention, has an optical fiber including a core to which a rare earth element is added and a clad disposed around the core, and also has an excitation light source for emitting excitation light incident on a side of the optical fiber. The optical fiber has a corrugated shape on the outer circumference of the clad along the longitudinal direction thereof; and the optical fiber is wound in a spiral form and is bundled in such a way that adjacent sides of the clad are brought into contact with one another.

Abstract: An amplitude setting circuit for setting an amplitude level of its output signal corresponding to an input signal. By setting a current flowing through a first diode-connected transistor (Q5) and a current flowing through a first drive transistor (Q1) to be in a predetermined relationship, variation with temperature in potential at a first connection point of the first drive transistor (Q1) and a first conductivity-type transistor (M1) is removed, and by setting a current flowing through a second diode-connected transistor (Q6) and a current flowing through a second drive transistor (Q4) to be in a predetermined relationship, variation with temperature in potential at a second connection point of a second conductivity-type transistor (M2) and the second drive transistor (Q4) is removed.

Abstract: A plurality of light emitting elements 11 are arranged in parallel with a constant pitch to provide a semiconductor laser bar 10. An optical waveguide 20 has a core part 21 for guiding a light emitted from each of the light emitting elements 11 and a cladding part 22 formed around the core part 21. An optical fiber 30 has a core 31 and a cladding 32 formed around the core 31 for confining the light to the core 31. The optical waveguide is bonded to a side surface of the optical fiber 30, and the light emitted from the semiconductor laser bar 10 is inputted to a side surface of the core 31 of the optical fiber 30 via the core part 21 of the optical waveguide 20.

Abstract: With a delta sigma modulator of this invention, a plurality of clocks required to control a switching circuit can be easily generated and correlation among phases of the plurality of clocks can be automatically maintained while a frequency of the clocks is modified. A ring oscillator is formed of three delay circuits provided with differential amplifiers in the delta sigma modulator. A clock producing circuit produces the plurality of clocks to control the switching circuit by delaying three-phase clocks outputted from the ring oscillator. All the tail currents Ic in the differential amplifiers in the delay circuits in the ring oscillator and the tail currents Ic in the differential amplifiers in the delay circuits in the clock producing circuit are proportional to each other.

Abstract: A constant current circuit that generates a constant output current corresponding to an input voltage, comprises a differential amplifying unit to which the input voltage and a feedback voltage to be compared therewith are applied, the differential amplifying unit outputting a differential voltage, a first transistor with a first control electrode to which the differential voltage is applied, a first diode element that is connected to a power-supply side electrode of the first transistor, one or a plurality of second transistors that generates the output current, a feedback voltage conversion block that converts the duplicated current of the diode current flowing through the second transistor into the feedback voltage, and a constant current loading unit that is connected to a ground side electrode of the first transistor, the constant current loading unit making a voltage change in the ground side electrode follow a voltage change in the first control electrode.

Abstract: In a delay circuit, when a first conductivity-type transistor (M6) becomes conductive on the basis of one level of its input signal, a first current path is formed through a source side transistor (M4), the first conductivity-type transistor (M6), and a second drive transistor (M9) between a source power line and a sink power line, and its output signal being the delayed inverse of the one level of the input signal is output from a connection point of another source side transistor (M5) and a sink side transistor (M11), and when a second conductivity-type transistor (M7) becomes conductive on the basis of the other level of the input signal, a second current path is formed through a first drive transistor (M3), the second conductivity-type transistor (M7), and another sink side transistor (M10), and the output signal being the delayed inverse of the other level of the input signal is output from the connection point.

Abstract: An amplitude adjusting circuit comprises a first current mirror where a variable current of a variable current source is copied into each of 1st-3rd transistors; a second current mirror where the variable current is copied into each of 11th-13th transistors; a third current mirror having 6th-7th transistors where a current through the 2nd transistor copied from the variable current flows through the 6th transistor; a fourth current mirror having 8th-9th transistors where a current through the 12th transistor copied from the variable current flows through the 8th transistor; an inverter that has 1st-2nd conductivity type transistors and produces an output signal corresponding to a current level of the 7th or 9th transistor; a fifth current mirror having 15th-14th transistors where a current through the 14th transistor copied from the 15th transistor's becomes a current sourced by the 7th transistor; and a sixth current mirror having 5th-4th transistors where a current through the 4th transistor copied from the

Abstract: A method of calculating a compensation value for an angle detecting sensor including a sensor unit, a signal converting section, a signal adjusting section, an arithmetic operation section, a memory section, and a compensator includes a first step of generating two signals having a predetermined phase difference from a plurality of output signals; a second step of calculating a rotation angle of an object from the two signals as an output angle before compensation; and a third step of extracting a candidate signal having a minimum residual energy in the signal after removal as the compensation value when a plurality of candidate signals having the same period but different amplitudes has been removed from a total error signal included in the output angle before compensation.

Abstract: A constant current circuit that generates a constant output current corresponding to an input voltage, comprises a differential amplifying unit to which the input voltage and a feedback voltage to be compared therewith are applied, the differential amplifying unit outputting a differential voltage between the input voltage and the feedback voltage, a first transistor with a first control electrode to which the differential voltage is applied, a first diode element that is connected to a power-supply side electrode of the first transistor, one or a plurality of second transistors that generates the output current duplicated from a diode current by applying to a second control electrode a voltage drop in the first diode element developed as a result of the diode current flowing through the first diode element due to drive of the first transistor, a feedback voltage conversion block that converts the duplicated current of the diode current flowing through the second transistor into the feedback voltage, which is

Abstract: In a delay circuit, when a first conductivity-type transistor (M6) becomes conductive on the basis of one level of its input signal, a first current path is formed through a source side transistor (M4), the first conductivity-type transistor (M6), and a second drive transistor (M9) between a source power line and a sink power line, and its output signal being the delayed inverse of the one level of the input signal is output from a connection point of another source side transistor (M5) and a sink side transistor (M11), and when a second conductivity-type transistor (M7) becomes conductive on the basis of the other level of the input signal, a second current path is formed through a first drive transistor (M3), the second conductivity-type transistor (M7), and another sink side transistor (M10), and the output signal being the delayed inverse of the other level of the input signal is output from the connection point.