Denso Corporation

Nippondenso Co., Ltd.

Seiki Aoyama

Yasuaki Makino

Minekazu Sakai

Susumu Kuroyanagi

Minoru Murata

Takamoto Watanabe

Yukihiro Takeuchi

Tsuyoshi Fukada

Shigenori Yamauchi

Tomoatsu Makino

Toshikazu Itakura

Ichiro Izawa

Ichirou Izawa

Kazuo Kajimoto

Kenichi Ao

Toshio Yamamoto

Shinji Yoshihara

Yoshimi Yoshino

Hirofumi Uenoyama

Kazushi Asami

Toshitaka Yamada

Seiji Fujino

Hiroshi Muto

Haruo Kawakita

Takeshi Shinoda

Masakazu Kanosue

Hiroshige Sugito

Kenji Yagi

Takanori Makino

Masakazu Terada

Shoji Ozoe

Izuru Shoji

Toshikazu Arasuna

Shigehiro Kasumi

Hirotsugu Funato

Yasuki Makino

Shinichi Konda

Masaki Takashima

Youko Nakagawa

A side collision detecting apparatus includes a pressure sensor disposed in a side door of a vehicle and including a diaphragm for detecting a pressure in the side door. The diaphragm has a pressure receiving surface configured to be distorted in accordance with a change in the pressure. The pressure sensor is arranged so as to satisfy one of a first condition where an angle between a line along which the pressure receiving surface extends and a horizontal line extending in a front-rear direction of the vehicle is from 60 degrees to 90 degrees and a second condition where the angle is less than 60 degrees or greater than 90 degrees and the pressure receiving surface is not vertical.

Side collision detecting apparatus for vehicle

A physical quantity sensor includes: a substrate; a movable element; two fixed elements; a carrier wave application element for applying two carrier waves to the fixed elements; a signal application element for applying a middle voltage to the movable element; and a detection circuit for detecting a physical quantity. The detection circuit executes a first self diagnosis process when the signal application element further applies a first self diagnosis signal to the movable element. The first self diagnosis signal has a first frequency for obtaining a resonant magnification equal to or larger than 1.1 times with respect to a resonant frequency of the movable element, so that the movable element is resonated and almost contacts or press contacts one fixed element. The detection circuit determines whether a sticking phenomenon occurs when the signal application element applies the first self diagnosis signal.

Physical quantity sensor

An oscillator includes first, second and third inverters () connected in series. A feedback path is connected from the output terminal of the third inverter () to the input terminal of the first inverterthrough a resistor () while a second feedback path is connected from the output terminal of the second inverter () to the input terminal of the first inverter () through a capacitor (). The second feedback path further includes a resistor () having a temperature coefficient larger than that of resistor () is inserted to adjust the charge/discharge trigger voltage and charge/discharge time of the capacitor ().

Oscillator circuit having stable frequency

A low-pass filter configured as a switched capacitor circuit in which capacitor charge switching is performed by 2-phase clock signals that control respective sets of switching elements, wherein an interval between a first-phase clock signal pulse and a succeeding second-phase clock signal pulse, during which no charging/discharging of capacitors should occur, is made as short as possible while ensuring that the two sets of switching elements cannot enter the ON state simultaneously. A low cut-off frequency can thereby be achieved, while using very small capacitor values.

Switched-capacitor low-pass filter and semiconductor pressure sensor apparatus incorporating the filter

In a switched capacitor filter circuit, a switching transistor is connected to an operational amplifier for input of a switching control signal to the operational amplifier. A noise compensation transistor is provided between the switching transistor and the operational amplifier. The drain and the source of the noise compensation transistor are connected to each other. The noise compensation transistor is applied with an inverted signal of the switching signal, and generates feedthrough noise of the polarity inverted from that generated by the switching transistor in order to cancel the feedthrough noise.

Switched capacitor filter circuit and method of fabricating the same

A dynamic quantity sensor has a weigh portion that is supported by a base portion to be displaced by a dynamic quantity, a movable electrode protruding from the weigh portion, and a fixed electrode protruding from the base portion and defining a detection interval with the movable electrode. The detection interval changes in response to displacement of the weight portion for detecting the dynamic quantity. Each of the movable electrode and the fixed electrode has a tapered plane shape with a width that decreases from a root portion toward a tip portion thereof.

Dynamic quantity sensor having movable and fixed electrodes with high rigidity

The clock signal for the sample and hold circuit for sampling the C-V conversion circuit output generated by the control signal generation circuit is different in period from the clock signal for switched capacitor filter circuit for filtering the sample and hold circuit output such that the clock signal for the switched capacitor filter circuit is unchanged in period between the measuring and self-diagnostic modes.

Capacitive physical quantity sensor

A semiconductor physical quantity sensor from which a stable sensor output can be obtained even when the usage environment changes. A silicon thin film is disposed on an insulating film on a supporting substrate, and a bridge structure having a weight part and moving electrodes and cantilever structures having fixed electrodes are formed as separate sections from this silicon thin film. The moving electrodes provided on the weight part and the cantilevered fixed electrodes are disposed facing each other. Slits are formed at root portions of the cantilevered fixed electrodes at the fixed ends thereof, and the width W of the root portions is thereby made narrower than the width W of the fixed electrodes proper. As a result, the transmission of warp of the supporting substrate to the cantilevered fixed electrodes is suppressed.

Semiconductor physical quantity sensor

A semiconductor dynamic quantity sensor includes a semiconductor support substrate having a specific resistance equal to or less than 3&OHgr; cm. An insulation film is provided on the support substrate and a semiconductor layer is provided on the support substrate with the insulation film interposed therebetween. The semiconductor layer has a specific resistance equal to or less than 3&OHgr; cm. A movable electrode is provided in the semiconductor layer to be displaced according to a dynamic quantity acting thereto. A fixed electrode is fixedly provided in the semiconductor layer to make a specific gap with the movable electrode and to from a capacitor with the movable electrode. The capacitor has a capacity that changes in response to displacement of the movable electrode to detect the dynamic quantity.

Method for manufacturing semiconductor dynamic quantity sensor

In a method for manufacturing a semiconductor acceleration sensor, a movable portion including a mass portion and movable electrodes is formed in a single crystal silicon thin film provided on a silicon wafer through an insulation film by etching both the single crystal silicon thin film and the silicon wafer. In this case, the movable portion is finally defined at a movable portion defining step that is carried out in a vapor phase atmosphere. Accordingly, the movable portion is prevented from sticking to other regions due to etchant during the manufacture thereof.

Magnetic resistive elements,and,cooperatively detect the change of the magnetic field responsive to the rotation of a gear,fixed to a shaft,An amplification circuit,comprises an operational amplifier,having an input terminal to which a gain-determining input resistor,is connected. A gain-determining feedback resistor,is provided in a feedback path of the operational amplifier,The gain-determining resistors,and,are formed by a P well region and a P,region of a MOS process element. The temperature characteristics of the gain-determining resistor,and,are opposed to that of the magnetic resistive elements,and,The temperature characteristics of the gain of the operational amplifier,cancel the temperature characteristics of the magnetic resistive elements,and

Temperature-compensating amplification circuit and a position detecting apparatus using such amplification circuit

To correct an unintentionally erasing error in an EPROM circuit, in accordance with the same one-bit data, each of first and second EPROM cells is either unprogrammed to output a first logic value representing an unprogrammed condition when reading or programmed to output a second logic value representing a programmed condition when reading. A logic operation gate outputs the first logic value when both the first and second EPROM cells output the first logic value and outputting the second logic value when at least one of the first and second EPROM cells output the second logic value. To correct unintentionally writing error in an N-bit EPROM circuit, a first parity is stored and a second parity is detected from N logic operation gates. If the first parity disagrees with the second parity, a correction signal is generated. In the presence of the correction signal, when it is detected at each of N-bit that an output of the first EPROM cell disagrees with that of the second one, an inverted output of the logic operation gate at the bit instead the output of the logic operation gate.

EPROM circuit with error correction

A magnetoresistance element detects an angular position of a toothed gear rotated by an engine. The element (first element) is positioned at a vicinity of the peripheral edge of the gear tooth in a magnetic filed supplied from a bias magnet. The magnetic field direction is changed by the tooth, which is detected by the element even when the gear is not rotated before the engine starts. To detect an exact angle of the gear, an additional magnetoresistance element positioned perpendicularly to the first element may be used. The gear tooth position is detected by the first element even when the gear is not rotated, and once the gear rotates, the second element detects an exact angular position of the gear.

Rotation detector using magnetoresistance element positioned in vicinity

A rotation object is made of a magnetic material and disposed within a predetermined range of an angle of rotation on a plane perpendicular to an axis of rotation. A bias magnet generates a bias magnetic field to the rotation body in a direction perpendicular to the axis of rotation. Magnetic resistance elements are disposed in the bias magnetic field on a plane including the axis of rotation at a position deviated from the position of the rotation object in the axial direction of the rotation body and inclined by about 45.degree. relative to a direction perpendicular to the axis of rotation.

Magnetoresistive type position sensor having bias magnetic and magnet

An automatic gain control circuit for controlling the gain of an amplifier amplifying an ac signal is provided which includes a resistance circuit, a comparing circuit, a gain control determining circuit, and a gain controlling circuit. The resistance circuit includes a plurality of resistors connected in series through taps. The comparing circuit compares an output signal of the amplifier with reference upper and lower limit values to determine whether the output signal of the amplifier is within a desired amplitude range of the reference upper limit value to the reference lower limit value or not. The gain control determining circuit determines whether the output signal of the amplifier has exceeded the upper and lower limit values sequentially during a complete cycle thereof for determining whether the gain of the amplifier should be changed or not. The gain controlling circuit selectively short-circuits the taps on both sides of each of the resistors of the resistance circuit to change a total resistance of the resistance circuit for controlling the gain of the amplifier when the output signal of the amplifier has exceeded the upper and lower limit values sequentially.

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Toyohashi, Japan

Seiki Aoyama