Hitachi, Ltd.

Takeo Nagata

Satoshi Shimada

Yoshitaka Matsuoka

Yutaka Sakurai

Mitsuo Ai

Motohisa Nishihara

Yoshimi Yamamoto

Akira Nagasu

Yosimi Yamamoto

Yukio Takahashi

Akira Ikegami

Kazuji Yamada

Yasumasa Matsuda

Hiroyasu Uchida

Akio Yasukawa

Masao Fukunaga

Masanori Tanabe

Ko Soeno

Akira Sase

Masatoshi Tsuchiya

Tsutomu Okayama

Syozo Kasai

Tomio Yasuda

Tomomasa Yoshida

Keiichi Satou

Yoshikatsu Satomi, Deceased

In an apparatus for checking patterns on printed circuit boards by comparing two patterns formed on two printed circuit boards, registration patterns each including orthogonal straight line segments and respectively formed on the two printed circuit boards are imaged by two imagers, and registration images from the imagers are matched by means of a registration unit to accurately match an image of a pattern to be checked on one printed circuit board with an image of a reference pattern on the other printed circuit board.

Apparatus for checking patterns on printed circuit boards

A differential pressure transmitter has a pressure receiving portion and a sensor portion which are constituted from separate parts separably jointed with each other. The sensor portion includes a semiconductor sensor having one side formed with a resistance pattern and the other side which has a thick-walled peripheral portion and a thick-walled central portion. The semiconductor sensor is incorporated in the sensor portion as being supported at the thick-walled peripheral portion thereof. The pressure receiving portion includes seal diaphragms disposed on both sides of the pressure receiving portion and a central diaphragm disposed therein. The semiconductor sensor is arranged such that the side thereof carrying the resistance pattern faces the pressure receiving portion.

Differential pressure transmitter

A pressure transducer is arranged to mount a semiconductor pressure sensor in a housing such that the pressure of a high-pressure fluid is applied to one side of the semiconductor pressure sensor through a high pressure seal diaphragm and a sealed liquid in the high pressure side, while the pressure of a low-pressure fluid is applied to the other side of the sensor through a low-pressure seal diaphragm and a sealed liquid in the low pressure side, and a protecting member is provided closer to the low-pressure seal diaphragm.

Pressure transducer

A differential pressure transducer having a cantilever and a semiconductor strain gauge attached to each side of the cantilever at an intermediate portion of the latter. The cantilever has one end fixed by electron beam welding to a fixing member and the other end left for free displacement in response to a differential pressure. The displacement of the other end of the cantilever is detected as changes in the electric resistances of the semiconductor strain gauges.

Differential pressure transducer

A semiconductor substrate has a major surface, another major surface on the opposite side of the first major surface, a strain gauge stripe formed in the central portion of the second major surface by diffusing an impurity therein, and electrodes connected to the strain gauge stripes. These strain gauge stripes are spaced from the peripheral edge of the second major surface by a distance greater than 1/3 of the length of the same major surface. The first major surface of the semiconductor substrate is bonded to an elastic metal load plate.

Semiconductor strain gauge with elastic load plate

A pressure transducer has at least one pressure transmitting space filled with liquid, a space for a pressure to be sensed connected to the pressure transmitting space through a diaphragm, and a pressure sensitive element in the pressure transmitting space for transducing a pressure transmitted from the space for the pressure to be sensed to the pressure transmitting space through the diaphragm to an electrical signal. A printed circuit board wired to electrically connect terminals of the pressure sensitive element is arranged closely to the element and thin temperature sensitive elements for temperature-compensating the pressure sensitive element are arranged on the printed circuit board.

A semiconductor transducer comprising an improved strain-yielding body yielding a strain in response to the impartation of a force or displacement, and a semiconductor strain gauge bonded to the strain-yielding body. The improved strain-yielding body is made of an iron-nickel-cobalt alloy containing 28.2 to 31.0% by weight of nickel and 15.0 to 19.5% by weight of cobalt. This iron-nickel-cobalt alloy is initially heated up to a temperature above 600.degree. C. for the purpose of standard heat treatment for removing its internal strain. After the standard heat treatment, the iron-nickel-cobalt alloy is subjected to cold working at a working rate of more than and including 60%, and is then subjected to heat treatment at a temperature between 350.degree. C. and 600.degree. C. The heat-treated iron-nickel-cobalt alloy is shaped into the predetermined form of the strain-yielding body.

Semiconductor transducer

A filled-in-fluid and diaphragm type intermediate device for transmitting pressure and for use with a pressure, liquid level or flow rate transmitter is disclosed, which enables the measurement of the pressure, liquid level or flow rate at a high temperature by using a conventional transmitter. This device includes a fluid-contacting flange having mounted thereon a pressure receiving element and coupled to a flange provided on the side of a fluid to be measured. A sealing flange having mounted thereon a diaphragm is provided on the side of a meter proper. A pressure transmitting pipe is coupled to the fluid-contacting flange and to the sealing flange, and contains therein a pressure-transmitting fluid which is adapted for use at a high temperature or as anti-radiant-ray fluid.

Filled-in-fluid and diaphragm type intermediate device for transmitting

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Hitachi, Japan

Takeo Nagata