Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Seiko Suzuki

Masayuki Miki

Shigeki Tsuchitani

Masahiro Matsumoto

Satoshi Shimada

Takao Sasayama

Yoshihiro Yokota

Hiroshi Kuroiwa

Masayoshi Kaneyasu

Seiichi Ugai

Minoru Takahashi

Sadayasu Ueno

Kanji Kawakami

Akira Koide

Motohisa Nishihara

Norio Ichikawa

Masahiro Komachiya

Masayoshi Suzuki

Hiromichi Ebine

Masahiro Kurita

Hideo Sato

Kazuo Sato

Kazuji Yamada

Shigeru Oho

Kanemasa Sato

Hitoshi Minorikawa

Toru Sugawara

Sigeyuki Kobori

Keiji Hanzawa

Norio Hasegawa

Kazuo Kato

Akira Ikegami

Hiroshi Sato

Nobuo Sato

Kaoru Uchiyama

Ryoichi Kobayashi

Masahide Hayashi

Shotaro Naito

Yoshikazu Hoshi

Matsuo Amano

Korefumi Tashiro

Yutaka Misawa

Hiroaki Hachino

Susumu Murakami

Tomoyuki Tanaka

Hidehito Obayashi

Terumi Nakazawa

Satoshi Suzuki

Masanori Kubota

Shigeyuki Kobori

Masahiro Takasaka

Keisuke Bekki

Takahiko Tanigami

Ryosaku Kanzawa

Yasuhiro Asano

Toshitaka Suzuki

Naoki Minami

Yukiko Sugisawa

Ichiro Kimura

Toru Takahasi

Shiro Ouchi

Benjamin Kloeck

Yukiko Kawai

A combustion pressure sensor suitable for a highly precise combustion control system of an automobile engine and a sensing system using the sensor. The combustion pressure sensor includes a SOI substrate having a three-layered structure of a first silicon plate, a thermal oxide film, and a second silicon plate, wherein a combustion pressure is sensed on the basis of a pressure or a force applied to the first silicon plate.

Semiconductor-type pressure sensor with sensing based upon pressure or

An in-cylinder pressure sensing apparatus for a multi-cylinder engine has a plurality of sensing parts packaged between a cylinder head and a cylinder block of an engine having a plurality of cylinders and being operative to detect a signal indicative of an internal pressure of each of the plurality of cylinders. A detection circuit is provided for connecting the sensing parts in series and for overlapping detection signals obtained from the individual sensing parts to take out a resulting overlapped signal. A reference signal generator operates to supply a reference signal for separating detection signals corresponding to the individual cylinders from the overlapped signal. A unit is also provided for separating the detection signals, detected in accordance with pressures of the individual cylinders, from the overlapped signal on the basis of the reference signal.

In-cylinder pressure sensing apparatus for multi-cylinder engine

A physical quantity detecting apparatus comprises at least one optical fiber, at least one light emitting means for emitting an incident light beam on the optical fiber, at least one light receiving means for detecting an outgoing light beam from the optical fiber, physical quantity applied position information generating means for providing information indicative of a position of a portion at which a physical quantity is applied to the optical fiber, and operation means for receiving signals from the light receiving means and physical quantities applied position information generating means and calculating a change with time in physical quantity at respective positions on the optical fiber.

Physical quantity detecting apparatus and internal combustion engine

A capacitance detector comprises switches for charging and discharging a sensing part, an integrator constituted by a condenser and an operational amplifier for integrating a charging current or a discharging current which is generated according to the charging and discharging the sensing part, a switch for charging an output voltage of the operational amplifier and for feedbacking an electric charge to the integrator, and a condenser. The capacitance detector can be provided by the operational amplifier having a low response performance and a small output current and no hold sample circuit, thereby a circuit scale of the capacitance type sensor can be made small.

Capacitance type sensor device

A detector for detecting a physical quantity as a quantity of electricity has a detection portion, a portion for stimulating the detection portion and a signal processing portion, wherein a calibration signal is supplied from the signal processing portion to the detection portion via the stimulating portion so as to measure a specific response of the detection portion, whereby self-calibration and correction of the characteristic of the detector are performed in accordance with an amount of a change in the response.

Detector having self-calibration function

A capacitance type accelerometer, having a fist silicon plate formed a movable electrode which is moved according to acceleration, two second silicon plates which are disposed on both sides of the first silicon plate with a certain separation distance, and thermal oxide films which are respectively disposed between the first silicon plate except the movable electrode and the two second silicon plates and stick the first silicon plate except the movable electrode and the two second silicon plates together. And further, a capacitance type accelerometer, having, a silicon plate formed a movable electrode which is moved according to acceleration, glass plates respectively mounting a conductive layer thereon which are opposite to the silicon plate with a certain separation distance and are sticked to the both side of the silicon plate except the movable electrode and leeding wires which are respectively connected to the conductive layers through a groove formed between the silicon plate and the glass plates respectively deriving. These capacitance type accelerometers are made by processing and cutting a wafer by dicing saw without coming into the accelerometer of cutting chips or cutting water.

Capacitance type accelerometer

An air bag operation device which employs only one CPU module to guarantee sufficient fail-safety in the operation of the air bag without increasing the scale of the hardware. A plurality of crash-discriminating programs of different versions and a plurality of self-diagnosing programs of different versions are executed by a single CPU module, a signal is fed to an air bag igniting device based upon a comparison of the discriminated results by the plurality of crash-discriminating programs, and a signal is fed to an abnormality alarm device based upon comparison of the discriminated results of the plurality of self-diagnosing programs.

Air bag operation device

A semiconductor acceleration sensor is formed by a cantilever having a conductive movable electrode of predetermined mass at one end, at least one pair of fixed conductive electrodes which are stationary with respect to the movable electrode located on opposing sides of the movable electrode, and gaps provided between the movable electrode and the fixed electrodes. To prevent the movable electrode becoming fused to the contacted fixed electrode, in a first aspect of this invention, an insulating layer is provided between the movable electrode and fixed electrodes, the layer being either on the movable electrode or on the fixed electrodes and in a second aspect the movable electrode or, preferably, the fixed electrodes, are formed of a high melting point material. In such a second aspect, to improve adhesion between the high melting point material and a substrate to which the fixed electrodes are mounted, a lower melting point material is firstly coated on the substrates. A sensor detector unit processing circuit has the output characteristic of the circuit digitally adjusted by suitable switching of a plurality of resistors, and the sensor chip and the detector unit integrated circuit may be located on a common base and mounted in a hermetically sealed chamber to prevent adverse environmental effects affecting operation of the sensor and detector unit assembly. A gas having a dew point of -40.degree. C. or lower is, advantageously, charged into the hermetically sealed chamber.

Semiconductor acceleration sensor and vehicle control system using the

A capacitance type accelerometer, having a fist silicon plate formed a movable electrode which is moved according to acceleration, two second silicon plates which are disposed on both sides of the first silicon plate with a certain separation distance, and thermal oxide films which are respectively disposed between the first silicon plate except the movable electrode and the two second silicon plates and stick the first silicon plate except the movable electrode and the two second silicon plates together. And further, a capacitance type accelerometer, having, a silicon plate formed a movable electrode which is moved according to acceleration, glass plates respectively mounting a conductive layer thereon which are opposite to the silicon plate with a certain separation distance and are sticked to the both side of the silicon plate except the movable electrode and leading wires which are respectively connected to the conductive layers through a groove formed between the silicon plate and the glass plates respectively deriving. These capacitance type accelerometers are made by processing and cutting a wafer by dicing saw without coming into the accelerometer of cutting chips or cutting water.

A method of manufacturing structures such as a pressure gauge, an accelerometer and the like with a single crystal material such as silicon uses etching techniques where the shape of a part subjected to stress concentration has a curvature, another part is formed in a plane body and a polyhedron is constituted by combining both. To attain the above constitution, a wafer of single crystal material is formed with a stepped surface having a value corresponding to at least the depth of the curvature in a first anisotropic etching process using a prescribed etching mask, and in a second anisotropic etching process, an etching mask is used by removing at least a part of the etching mask used in the first anisotropic etching process.

Structure and method of manufacturing the same

An electrostatic type micro accelerometer comprising means for preventing permanent sticking between a movable electrode and a stationary electrode due to residual dielectric polarization, resisual electric charges and water adsorption and condensation around possible contacting portions therebetween when the movable electrode excessively displaces. The sticking preventing means is realized by disposing one of electric field reducing means, water adsorption and condensation reducing means and contacting area limiting means around the possible contacting portions.

Electrostatic type micro transducer and control system using the same

A signal processor (5) is coupled to a detector (6) for detecting a physical quantity. The signal processor has a zero adjustment memory (14) and a sensitivity adjustment memory (16). The zero adjustment memory and the sensitivity adjustment memory have a number of switches (20, 20A, 20', 20'), respectively. These switches are changed over digitally using a zener zapping method or a polysilicon fuse method at each switch to adjust the characteristics of the detector.

Sensor

In a capacitance type accelerometer used for an air bag system etc., a plurality of grooves crossing each other are provided on the surface of a movable electrode which is arranged to face a fixed electrode at a portion having a gap thereinbetween, and end portions of each groove open to an outside space at the portion between the movable electrode and the fixed electrode. The grooves can be provided on surface of the fixed electrodes. Ventilation between inside and outside of the facing portion is improved by opening of the grooves to outside space, and air damping which is caused at operation of the movable electrode at the gap between the electrodes is reduced, and, consequently, response speed of the movable electrode is increased.

Capacitance type accelerometer for air bag system

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Hitachioota, Japan

Seiko Suzuki