Hitachi Metals, Ltd.

Isao Sakaguchi

Kengo Suzuki

Masaru Noda

Atsushi Kazama

Masakatsu Saitoh

Takahiro Umeyama

Yoshio Ikeda

Masayuki Hosoda

The present invention makes it possible to, even when a stainless steel is adopted in a diaphragm: prevent the diaphragm and a strain sensor from exfoliating from each other; be hardly susceptible to the influence of temperature in an operating environment; not allow the sensitivity of a pressure sensor to be dominated only by the mechanical characteristic of a material constituting the diaphragm; and increase the degree of freedom in design of members constituting the pressure sensor. A pressure sensor according to the present invention is, in order to solve the above problems, characterized in that: the pressure sensor has a diaphragm deforming by the pressure of a fluid, an elastic body covering the whole surface of the diaphragm and joining to the diaphragm on one side, and a strain sensor being arranged by joining on the other side of the elastic body and on an end side apart from a position corresponding to the center of the diaphragm and detecting the deformation of the elastic body working together with the deformation of the diaphragm as a strain; and the elastic body is formed of a material having a linear expansion coefficient close to the linear expansion coefficient of a material constituting the strain sensor.

Pressure sensor, differential pressure sensor, and mass flow rate control device using same

There is provided a pressure sensor which includes: a diaphragm having an inside surface facing to a fluid-tight space, the diaphragm including a diaphragm film that is part of the inside surface and deformable in response to a pressure application, and a diaphragm film support that is part of the inside surface and constitutes a periphery of the diaphragm film; a strain sensor bonded to the inside surface so as to lie partially on the periphery and having plural strain gauges thereon; and a depression formed on the inside surface, when defining an x-direction oriented from center of the inside surface to a position bonded of the strain sensor and a y-direction perpendicular to the x-direction on the inside surface, the depression extending a certain length in the y-direction, the depression being adjacent to or a certain distance apart from an edge of the strain sensor in the y-direction.

Pressure sensor, and mass flow meter, and mass flow controller using same

An acceleration sensor device comprising: an acceleration sensor chip comprising a mass portion, a support frame and flexible arms having piezo-resistors on their top surfaces; and an upper regulation plate having an IC circuit, which is larger in area than the support frame, bonded to a top surface of the support frame; wherein the acceleration sensor chip and the upper regulation plate are placed in a protection case with a lid. The regulation plate protrudes from outside walls of the support frame to partition the space accommodating the chip in the protection case by the protrusion and to prevent air circulation above and below the regulation plate, so that a temperature rise due to the IC circuit among the piezo-resistors provided on the top surfaces of the flexible arms is kept uniform to reduce offset voltage.

Acceleration sensor device having piezo-resistors measuring acceleration

A fall detecting method and a device for detecting a fall with high accuracy even when an object touches a human or a thing while falling. The fall detecting device has an output detecting part for generating an acceleration detection output after comparing the magnitude of acceleration detected by a three-axis acceleration sensor with a certain threshold, an output interruption correcting part for generating an output interruption corrected acceleration output which is corrected for an interruption when a fall acceleration output recovers within a first predetermined time after the fall acceleration output interrupts, and an output continuation time judging part for generating a fall judgment output when the output interruption corrected acceleration output continues for a second predetermined time longer than the first predetermined time.

Fall detecting method and fall detecting device

A semiconductor acceleration sensor is disclosed which has a small difference in acceleration detection sensitivity among X, Y, and Z axes and a high detection sensitivity. The acceleration sensor has a mass portion in its center, a support frame surrounding the mass portion, and a plurality of flexible arms connecting the mass portion and the support frame. The flexible arm has wider portions on both ends and a narrower portion between the wider portions. Piezo resistors are restrictedly provided within a top surface region of the wider portion of the flexible arm, and through holes connecting metal wires and the piezo resistors are disposed on the mass portion/support frame. The plurality of flexible arms are symmetric with respect to the center of the mass portion, and each of the flexible arms is symmetric with respect to the center line of the flexible arm.

Semiconductor acceleration sensor

An acceleration measuring apparatus capable of calibrating its output with a zero-point in the state of no acceleration applied as well as sensitivity. An acceleration sensor detects each component of an acceleration and creates an output based on each of the detected components in each direction of at least two mutually perpendicular axes of orthogonal coordinates for the acceleration sensor. The acceleration sensor is held at at least two different positions; each of the acceleration sensor axes at one position is at a angle, with the gravitational acceleration direction, that is different from the angle at the other position. A processing circuit develops calibration parameters based on output by each component in the at least two axis directions of the gravitational acceleration measured by the acceleration sensor positioned at each of the at least two different positions and calibrates the output of the acceleration measured by using the calibration parameters to provide a calibrated output.

Growing community of inventors

Saitama, Japan

Isao Sakaguchi