Measuring and testing – Speed – velocity – or acceleration – Acceleration determination utilizing inertial element
Reexamination Certificate
1999-07-26
2001-11-27
Kwok, Helen (Department: 2856)
Measuring and testing
Speed, velocity, or acceleration
Acceleration determination utilizing inertial element
C073S514010
Reexamination Certificate
active
06321600
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to an acceleration detecting device, and more particularly to an acceleration detecting device for detecting acceleration in all directions.
A conventional acceleration detecting device is typically constructed in such a manner as disclosed in U.S. Pat. No. 5,365,799, U.S. Pat. No. 5,571,972, Japanese Patent Application Laid-Open Publication No. 132845/1998, Japanese Patent Application Laid-Open Publication No. 153614/1998 or the like. The acceleration sensor disclosed includes a diaphragm provided on a central region thereof with a weight, a base made of a metal material and arranged so as to support an outer periphery of the diaphragm, and an acceleration sensor element fixed on a surface of the diaphragm opposite to a surface thereof on which the weight is arranged. Such an acceleration detecting device is constructed so as to detect acceleration in a predetermined direction in such a manner that the acceleration sensor element outputs an acceleration signal depending on deformation of the diaphragm due to application of acceleration to the weight. In particular, an acceleration detecting device disclosed in U.S. Pat. No. 5,571,972 is constructed in the form of a single unit wherein a weight, a diaphragm and a base are formed integrally with each other. The weight, diaphragm and base are mounted directly on a casing of a measuring equipment or an electronic equipment.
Unfortunately, the conventional acceleration detecting device substantially fails to accurately position the weight, diaphragm and base on a casing of a measuring equipment or an electronic equipment.
SUMMARY OF THE INVENTION
The present invention has been made in view of the foregoing disadvantage of the present invention.
Accordingly, it is an object of the present invention to provide an acceleration detecting device which is capable of permitting a weight, a diaphragm and a base to be precisely positioned on a casing of a measuring equipment or an electronic equipment.
It is another object of the present invention to provide an acceleration detecting device which is capable of facilitating mounting of a weight, a diaphragm and a base on a casing of a measuring equipment or an electronic equipment.
It is a further object of the present invention to provide an acceleration detecting device which is capable of preventing occurrence of an error in output thereof due to noise.
In accordance with the present invention, an acceleration detecting device is provided. The acceleration detecting device includes a weight, a diaphragm provided on a central portion thereof with the weight, a base for supporting an outer periphery of the diaphragm, an acceleration sensor element fixed on a surface of the diaphragm opposite to a surface of the diaphragm on which the weight is arranged and constructed so as to output an acceleration signal depending on deformation of the diaphragm due to an action of acceleration on the weight, and an insulating casing made of an insulating resin material and constructed so as to receive the weight, diaphragm, base and acceleration sensor element therein. The acceleration detecting device of the present invention may be any of a one-axis acceleration detecting device for detecting acceleration in a direction of only one axis (X-axis), a two-axis acceleration detecting device for detecting acceleration in each of directions of two axes (X- and Y-axes) and a three-axis acceleration detecting device for detecting acceleration in each of directions of three axes (X-, Y- and Z-directions). In the present invention, the weight, diaphragm and base are integrally formed of a metal material into a single unit. The insulating casing is integrally formed while incorporating the single unit as an insert therein.
The above-described integral formation of the insulating casing while incorporating the single unit as insert therein permits the insulating casing of a desired configuration to be integrally formed together with the weight, diaphragm and base. Thus, mounting of the insulating casing on a casing of a measuring equipment or an electronic equipment permits the single unit to be precisely positioned on the casing of the measuring equipment or the electronic equipment. Also, it facilitates mounting of the weight, diaphragm and base on the casing of the measuring equipment or the electronic equipment.
The acceleration detecting device of the present invention may be so constructed that the insulating casing is provided therein with a recess in which the acceleration sensor element is received and the terminal fitments include ground terminals electrically connected to the base. It is preferable that the recess of the insulating casing is closed with a cover member made of a metal material and the cover member is integrally provided with a contactor, which is elastically pressed against the base when the cover member is kept fixed on the insulating casing so as to close the recess.
Such construction permits the cover member to be grounded through the contactor, base and ground terminal. This permits the metal cover member to act as a shield for shielding noise such as an electromagnetic wave or the like, to thereby prevent intrusion of the noise into the acceleration sensor element. In particular, the contactor is elastically forcibly pressed against the base, so that electrical connection between the cover member and the base may be carried out concurrently with mounting of the cover member and contact between the base and the contactor may be ensured.
Also, in accordance with the present invention, an acceleration detecting device is provided. The acceleration detecting device includes a piezoelectric ceramic substrate, an acceleration sensor element including a detection electrode for detection of acceleration and a plurality of electrodes arranged on one surface of the piezoelectric ceramic substrate and a counter electrode pattern arranged on the other surface of the piezoelectric ceramic substrate in a manner to be opposite to the detection electrode pattern, a diaphragm having the acceleration sensor element connected onto one surface thereof by means of an adhesive layer, a weight fixed on a central portion of the other surface of the diaphragm, a metal base provided with a receiving space in which the weight is received in a manner to be displaceable and arranged so as to support an outer periphery of the diaphragm, an insulating casing constructed so as to receive the diaphragm, base and acceleration sensor element and provided therein with a recess for receiving the acceleration sensor element therein, and a plurality of terminal fitments connected to the electrodes of the acceleration sensor element. The terminal fitments has ground terminals electrically connected to the base, so that the base is electrically connected to the ground terminals of the terminal fitments. The weight, diaphragm and base are integrally formed of a metal material into a single unit. The insulating casing is integrally formed while incorporating the single unit as an insert therein. The insulating casing includes a side wall defining the recess and provided with a window through which the base is partially exposed. The acceleration detecting device also includes a cover member made of a metal material and arranged so as to close the recess of the insulating casing. The cover member is integrally provided with a contactor elastically pressed against the base when the cover member is kept fixed on the insulating casing so as to close the recess.
REFERENCES:
patent: 5365799 (1994-11-01), Okada
patent: 5492011 (1996-02-01), Amano et al.
patent: 5571972 (1996-11-01), Okada
patent: 5668318 (1997-09-01), Okada
patent: 5744718 (1998-04-01), Okada
patent: 5864062 (1999-01-01), Nagahara et al.
patent: 6148671 (2000-11-01), Nakamizo et al.
Abstract for Japanese Patent No. 10153614 published Jun. 9, 1998.
Abstract for Japanese Patent No. 10132845 published May 22, 1998.
Ando Masato
Arikura Takeshi
Hirose Shigeru
Nakamizo Yoshiyuki
Sawai Tsutomu
Hokuriku Electric Industry Co., Ltd.
Kwok Helen
Rankin, Hill Porter & Clark LLP
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