Hitachi, Ltd.

Hitachi Car Engineering Co., Ltd.

Other

Mitsubishi Denki Kabushiki Kaisha

Hitachi Automotive Systems, Ltd.

Mitsubishi Electric Corporation

Hitachi Automotive Engineering Co., Ltd.

Hitachi, Ltd. and Hitachi Car Engineering Co., Ltd.

Junichi Horie

Izumi Watanabe

Keiichi Nakada

Kei Ueyama

Masamichi Yamada

Satoshi Shimada

Norio Ichikawa

Yasuo Onose

Seiji Kuryu

Keiji Hanzawa

Atsushi Miyazaki

Akihiko Saito

Masahiro Matsumoto

Atsuo Watanabe

Hiroshi Nakano

Takao Sasayama

Akio Yasukawa

Masayoshi Suzuki

Shinya Satou

Kazunori Suzuki

Yukiko Sugisawa

Keizi Hanzawa

Yuuji Ogasawara

Shinya Igarashi

Akira Uenodan

Kazushige Kawasaki

Akira Kotabe

Hitoshi Sakuma

Katsuomi Shiozawa

Tetsuya Yagi

Toshiyuki Oishi

Hiroshi Moriya

Seikou Suzuki

Naohiro Momma

Hiromu Kikawa

Yasuyuki Nakagawa

Harumi Nishiguchi

Toshihiko Shiga

Kyozo Kanamoto

Hiromasu Matsuoka

Yasuhiro Kunitsugu

Kei Ueda

Akihiko Saitou

The present invention provides a thermal flow rate measurement device that is capable of highly accurate correction of the temperature of an intake gas flow rate using a two-dimensional correction map that stores a correction value in association with temperature and intake gas flow rate. A gas flow rate measurement device that corrects a flow rate detection signal using a correction amount in which the correction amount is a correction amount in which a position displaced from a grid point of an orthogonal grid on a correction mapA is an acquisition point, and stores positional information of the acquisition pointon the correction mapA, and, at a time of flow rate measurement, determines a reference input flow rate that refers to the correction mapA on the basis of the positional information from a flow rate detection signal, determines a reference input temperature that refers to the correction mapA on the basis of the positional information from a temperature detection signal, and determines a correction amount corresponding to an input flow rate of an input flow rate Q axis corresponding to the reference input flow rate and an input temperature of an input temperature T axis corresponding to the reference input temperature.

Gas flow rate measurement device

The present invention is directed to a thermal flowmeter that prevents erroneous detection of backflow by suppressing circulation of air flow from a flow detection unit side to a back side or from the back side to the flow detection unit side and measures a gas flow rate with high accuracy. A thermal flowmeter of the present invention includes a bypass passage through which a gas to be measured passes; a dividing portion which divides the inside of the bypass passage into a first passage portion and a second passage portion; and a flow detection unit which is provided on a surface of the dividing portion on the first passage portion side and detects a flow rate of the gas to be measured. Further, the first passage portion has a detection surface on which the flow detection unit is exposed, an opposing surface which opposes the flow detection unit on the detection surface, and non-opposing surfaces and which are disposed at positions deviating from the opposing surface in a bypass passage width direction of the first passage portion and do not oppose the flow detection unit, and the non-opposing surface is separated from the detection surface farther than the opposing surface.

Thermal flowmeter

A thermal type flow rate measuring device can certainly prevent adhesion of water droplet onto a sensor element and thus achieve high reliability. The thermal type flow rate measuring device includes an auxiliary passage defined within a main passage for introducing a part of fluid flowing through the main passage, a sensor disposed within the auxiliary passage for detecting flow rate of the fluid and capturing means formed on an inner periphery of the auxiliary passage for capturing liquid contained in the fluid and transferring the captured liquid.

Thermal flow rate measuring device

A nitride semiconductor device includes an n-type GaN substrate with a semiconductor device formed thereon and an n-type electrode which is a metal electrode formed on the rear surface of the GaN substrate. A surface modified layer and a reaction layer are interposed between the GaN substrate and n-type electrode. The surface modified layer serves as a carrier supplying layer, and is formed by causing the rear surface of the GaN substrate to react with a Si-containing plasma to be modified. The reaction layer is generated by partially removing a deposited material deposited on the surface modified layer by cleaning to generate a deposited layer and then causing Ti contained in a first metal layer and the deposited layer to partially react by heat treatment.

Nitride semiconductor device and manufacturing method of the same

A semiconductor laser device has a front surface electrode formed by Au plating, a rear surface electrode formed by Au plating, an anti-adhesive film on the front surface electrode or the rear surface electrode and made of a material that does not react with Au, and a coating film that covers an end face on a light emitting side and an end face opposite the light emitting side. The anti-adhesive films may be located at least at the four corners of the front or rear surface electrode.

Semiconductor laser device

A flow rate sensor has a problem that a resistance value of a heat generating resistor itself varies and sensor characteristics are changed during use of the sensor for a long term. Also, the temperature of the heat generating resistor must be adjusted on a circuit substrate with a resistance constituting one side of a fixed temperature difference control circuit, and this has been one of factors pushing up the production cost. All resistances used for fixed temperature difference control are formed on the same substrate as temperature sensitive resistors of the same material. This enables all the resistances for the fixed temperature difference control to be exposed to the same environmental conditions. Hence, even when the resistances change over time, the changes over time occur substantially at the same tendency. Since the resistances for the fixed temperature difference control change over time essentially at the same rate, a resulting output error is very small.

Thermal type flow rate measuring apparatus

A thermal-type fluid flow sensor comprises a heating resistor formed on a thin film of a substrate, and plural thermal sensitive resistors configuring a bridge circuit. The thermal sensitive resistors are disposed on the thin film of the substrate so as to be located on an adjacent upstream side and an adjacent downstream side of the heating resistor in a stream direction of fluid to be measured. Resistor traces for the thermal sensitive resistors are formed so that the respective thermal sensitive resistors exhibit substantially equal changes in resistance with each other to distortion caused in the thin film.

Fluid flow sensor and fluid flow measurement device

A semiconductor laser device has a front surface electrode formed by Au plating, a rear surface electrode formed by Au plating, an anti-adhesive film only on the front surface electrode and made of a material that does not react with Au, and a coating film that covers an end face on a light emitting side and an end face opposite the light emitting side. The anti-adhesive films are located on the four corners of the front surface electrode.

A thermal type flow measuring apparatus includes a heating resistor provided in a thin part of a substrate and a bridge circuit for driving the heating resistor to have a preset heating temperature, wherein resistor elements on sides forming the bridge circuit are temperature sensitive resistors, a part or whole of at least one of the temperature sensitive resistors is placed in the thin part and near the heating resistor so that the temperature sensitive resistor is influenced by a heat of the heating resistor, and the preset heating temperature is increased as the flow of fluid is increased. This configuration introduces flow dependency into the heating temperature of the heating resistor.

Thermal type flow measuring apparatus

A semiconductor laser diode comprises: an n-type GaAs substrate; and a first laser diode structure having a first n-type cladding layer, a first active layer including a quantum well layer, a first p-type cladding layer on the first active layer, a p-type signal layer on the first p-type cladding layer and which has the same constituent elements as those of the first p-type cladding layer, and a p-type ridge waveguide in a stripe mesa-like shape on the signal layer, which has the same constituent elements as those of the signal layer, and in which composition ratios of two constituent elements in a complementary relation of constituent elements are different from those composition ratios of the signal layer.

Semiconductor laser device and method of manufacturing the same

A Thermal type fluid flow sensor comprises a heating resistor formed on a thin film of a substrate, and plural thermal sensitive resistors configuring a bridge circuit. The thermal sensitive resistors are disposed on the thin film of the substrate so as to be located on an adjacent upstream side and an adjacent downstream side of the heating resistor in a stream direction of fluid to be measured. Resistor traces for the thermal sensitive resistors are formed so that the respective thermal sensitive resistors exhibit substantially equal changes in resistance with each other to distortion caused in the thin film.

A gas flowmeter capable of reducing a secular change comprises a silicon semiconductor substrate formed with a cavity and a heat element formed above the cavity of the semiconductor substrate by way of an insulating film. The heat element is a silicon (Si) semiconductor thin film impurity-doped at high concentration. Stoichiometrically stable silicon nitride (SiN) thin films as barrier layers which less permeate and less absorb hydrogen in the heat generating temperature range of the heat element are formed above and below the silicon (Si) semiconductor thin film.

Method of manufacturing a gas flow meter

A thermal flow sensor which is fabricated at a low cost and has improved reliability. Over a cavity () formed in a semiconductor substrate (), at least a heating resistance () is formed near the center of the cavity with an electrical insulation film interposed between the heating resistance and the cavity. The temperature (Th) of the heating resistance () is controlled to be higher than the medium temperature (Ta) by a constant temperature (&#x394;Th=Th&#x2212;Ta). A distance (Ws) in the direction of airflow from an upstream end of the heating resistance () to an upstream end of the electrical insulation film lying over the cavity and the constant temperature (&#x394;Th) satisfy the following relationship:&#x394;&#x2266;800 (&#xb0; C./mm)Thus, a thermal flow sensor is provided which can prevent deposition of floating fine particles, such as carbon particles, caused by the thermophoretic effect, can be fabricated at a low cost, and has high reliability.

Thermal flow sensor

A low reflective film is formed of, in sequence from a side in contact with a laser chip, a first dielectric film of a refractive index nand a thickness d, a second dielectric film of a refractive index nand a thickness d, a third dielectric film of a refractive index nand a thickness d, and a fourth dielectric film of a refractive index nand a thickness d, specifically, aluminum oxide AlOwith a refractive index n=1.638 is used for the first dielectric film, silicon oxide SiOwith a refractive index n=n=1.489 for the second and fourth dielectric films, tantalum oxide TaOwith a refractive index n=2.063 for the third dielectric film, respectively, resulting in a semiconductor laser device with a reflectance which is stably controllable.

Semiconductor laser devices

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Hitachinaka, Japan

Junichi Horie