Denso Corporation

Kabushiki Kaisha Toyota Chuo Kenkyusho

Toyota Jidosha Kabushiki Kaisha

Norikazu Ohta

Yasutoshi Suzuki

Yasuaki Makino

Seiichiro Ishio

Hirofumi Funabashi

Keiichi Shimaoka

Hirofumi Funahashi

Kenichi Ao

Hajime Ito

Hideya Yamadera

Yoshie Ohira

Hiroshi Okada

Hiromi Ariyoshi

Kentaro Mizuno

Nobukazu Oba

Shin Yamamoto

Reiji Iwamoto

Keisuke Gotoh

Kazuhiro Kozuka

Yoshihiro Nishimura

Takehiko Okuda

Shinji Nakatani

Hidehiro Tomioka

Hideki Hosokawa

Yoshihisa Harata

Souichi Isikawa

A capacitive sensor device includes first and second sensor capacitors coupled in series, a clock signal generating part, an operational amplifier, a feedback capacitor, a compensating capacitor, and a compensating signal generating part. The clock signal generating part generates a first clock signal and the second clock signal applied to the first and second sensor capacitors, respectively. The compensating signal generating part generates a compensating signal applied to the compensating capacitor. The first clock signal and the second clock signal have the same frequency and the same amplitude and have phases being opposite each other. The compensating signal has a frequency same as the first clock signal and the second clock signal, has a phase same as one of the first clock signal and the second clock signal, and has an amplitude that is adjustable.

Capacitive sensor device

A peak voltage detector circuit detects a peak voltage of an input voltage. The input voltage is input into a first input terminal of a comparator. A counter circuit counts up a counter value in synchronization with a first clock signal, when a signal output from the comparator is in a first state. The counter circuit counts down the counter value in synchronization with a second clock signal. A digital-analog conversion circuit outputs an output voltage corresponding to the counter value, and the output voltage is input into a second input terminal of the comparator. The first clock signal has a wave period shorter than that of the second clock signal.

Peak voltage detector circuit and binarizing circuit including the same circuit

A magnetic sensor apparatus includes a semiconductor substrate and a magnetic impedance device for detecting a magnetic field. The magnetic impedance device is disposed on the substrate. The magnetic sensor apparatus has minimum size and is made with low manufacturing cost. Here, the magnetic impedance device detects a magnetic field in such a manner that impedance of the device is changed in accordance with the magnetic filed when an alternating current is applied to the device and the impedance is measured by an external electric circuit.

Method for manufacturing magnetic sensor apparatus

1to npairs of transistors (n=an odd number) are connected in parallel, and each pair of transistors has an upper transistor and a lower transistor connected in series. A point between the upper transistor and the lower transistor of a preceding pair of transistors is connected to a gate of the lower transistor of a subsequent transistor, and the point between the upper transistor and the lower transistor of npair of transistors is connected to the gate of the first lower transistor. A capacitor is inserted between the lower transistor and a direct power source. A current regulating circuit connected to gates of the upper transistors, wherein the current regulating circuit supplies a gate voltage to each gate of the each upper transistor. The magnitude of the gate voltage is adjusted such that a magnitude of current that flows between the source and drain of the upper transistor due to the gate voltage is proportional to a voltage between the source and gate of the corresponding lower transistor when the lower transistor is turned on.

Clock signal output circuit

Magnetic impedance device, sensor apparatus using the same and method for manufacturing the same

A reference voltage circuit includes an operational amplifier, a first fixed resistance resistor, a second fixed resistance resistor, a third fixed resistance resistor, a first diode and a second diode. The reference voltage circuit further includes a fourth fixed resistance resistor having an end connected to a non-inverting input terminal of the operational amplifier and the other end connected to the first diode. The reference voltage circuit is characterized by a value of the resistance of the fourth resistor being less than the resistance of the first resistor and a temperature coefficient of the fourth resistor being greater than any of the temperature coefficients of the first, second and third resistors.

Circuit for outputting stable reference voltage against variation of background temperature or variation of voltage of power source

First and second predetermined charging voltages are applied between the movable and fixed electrodes of a capacitive type of sensor to measure first and second capacitances between the movable and fixed electrodes, respectively. The first and second electrostatic capacitances are compared to obtain a characteristic of the sensor from a result of comparison. In measuring the first and second capacitances, first and second charging voltages are generated of which magnitudes are determined in accordance with the first and second capacitances, respectively. Equalization is made between the first output voltage when the first charging voltage is applied between the movable and fixed electrodes in a predetermined normal condition of the movable electrode and the second output voltage outputted when the second charging voltage is applied between the movable and fixed electrodes in the predetermined normal condition.

METHOD OF MEASURING A CHARACTERISTIC OF A CAPACITIVE TYPE OF SENSOR, A SENSOR CHARACTERISTIC MEASURING APPARATUS, A CAPACITIVE TYPE OF SENSOR APPARATUS, AND AN IC CHIP FOR MEASURING A SENSOR CHARACTERISTIC

In a capacitive sensor apparatus, a capacitive sensor includes a plurality of physical-quantity-detection capacitors each having a movable electrode and a fixed electrode. A conversion device operates for converting an output signal of the capacitive sensor into an apparatus output signal. Each of the physical-quantity-detection capacitors is selectively connected and disconnected to and from the conversion device. A determination is made as to whether or not each of the physical-quantity-detection capacitors fails in response to the sensor output signal. When it is determined that a first one of the physical-quantity-detection capacitors fails, the first one is disconnected from the conversion device and a second one of the physical-quantity-detection capacitors is connected to the conversion device.

Capacitive sensor apparatus

A capacitive physical load sensor includes a substrate, which has fixed electrodes, and a diaphragm, which has movable electrodes. The diaphragm is located across a gap from the substrate, and retaining parts for the diaphragm are formed around the diaphragm. Protruding parts extend into the gap from the diaphragm or from the substrate. The protruding parts support the diaphragm at different levels of deformation to alter the characteristics of the diaphragm and extend its range.

Capacitive physical load sensor and detection system

Interrogator/transponder system and mobile transponder device

Growing community of inventors

Aichi-gun, Japan

Norikazu Ohta