JP5509399B1 - Inertial sensor - Google Patents

Abstract

An object of the present invention is to accurately detect acceleration and angular velocity with high detection sensitivity without adversely affecting detection results depending on the use environment.
A plate-like bridge portion 720 and a plate-like bridge portion 730 extend from a plate-like member 711 fixed to a bottom plate 800 of the apparatus housing into a “U” shape, and a weight body 750 is connected to the tip. A cantilever beam structure is formed. Three sets of piezoresistive elements are arranged at four locations of the root end portion and the tip end portion of the plate-like bridge portion 720 and the root end portion and the tip end portion of the plate-like bridge portion 730, and the x-axis, y-axis, The acceleration acting in the z-axis direction can be detected. The intermediate connection portion 725 and the weight connection portion 740 are provided with eaves structure portions 801, 802, and 803 protruding outward from the side surfaces of the plate-like bridge portions 720 and 730, and the plate-like bridge portion is bent. Sometimes it plays a role in concentrating stress on the root and tip.
[Selection] Figure 36

Description

The present invention relates to an inertial sensor, and more particularly to an inertial sensor having a function of detecting an acceleration acting in a predetermined coordinate axis direction.

  In various vehicles, ships, airplanes, etc., acceleration sensors and angular velocity sensors are used to obtain attitude control and navigation information. Also, in robots and industrial machines, acceleration sensors and angular velocity sensors are attached to various locations in order to accurately control the movement. Among such sensors, a sensor that attaches a weight body to the inside of the apparatus housing via a flexible member and detects acceleration and angular velocity using the inertia of the weight body is generally called an inertia sensor. ing.

  For example, in the case of an acceleration sensor using inertia, when the device housing moves based on the applied acceleration, the internal weight body tends to stay in its original position due to inertia, so the weight body is attached to the device housing. A relative displacement is generated. By detecting the displacement electrically, the applied acceleration can be detected.

  On the other hand, in the case of an angular velocity sensor (gyro sensor) that uses inertia, the inertia that tries to maintain the vibration direction acts on the weight body that vibrates in the device casing. When rotated, the vibration axis relative to the apparatus housing changes. The detected angular velocity can be detected by electrically detecting the Coriolis force that causes the vibration axis to change.

  In such an inertial sensor, various support structures for supporting the weight body in the apparatus casing have been proposed, and various detection elements are used to detect the applied acceleration and angular velocity as an electrical signal. It's being used. For example, Patent Document 1 below discloses an acceleration sensor that employs a structure in which a weight body is suspended from a central portion of a diaphragm and a peripheral portion of the diaphragm is supported and fixed to an apparatus housing by a pedestal. In this acceleration sensor, a specific axial component of the applied acceleration can be detected as an electric signal by using a piezoresistive element formed at a predetermined position of the diaphragm.

  On the other hand, in Patent Document 2, by supporting the weight body with the same structure and configuring the diaphragm itself with a piezoelectric element, the generated acceleration in the piezoelectric element is utilized as an electrical signal. Techniques for detection are disclosed. In addition, since the piezoelectric element has a property of causing deformation when a voltage is applied, the AC drive signal is supplied to the sensor to vibrate the vibrator and the applied Coriolis force is detected. A method for detecting the angular velocity by doing so is also disclosed.

  Furthermore, Patent Document 3 discloses a support structure that supports a weight body with an L-shaped arm. The piezoelectric body is used to vibrate the weight body, and the acting Coriolis force is utilized using the piezoelectric element. An angular velocity sensor that detects an angular velocity by measuring the above is disclosed. The document also discloses a technique for detecting angular velocity using Coriolis force acting on four sets of weights using a structure in which four sets of weights are respectively supported by L-shaped arms. ing.

JP-A-6-174571 JP-A-8-35981 WO2008 / 035683

  As disclosed in the aforementioned Patent Documents 1 and 2, the conventional inertial sensor adopting a support structure in which the weight body is suspended at the center of the diaphragm and the periphery of the diaphragm is fixed by a pedestal has a very structure. Therefore, the manufacturing cost can be greatly reduced. In addition, since the displacement of the weight body can be detected by detecting the deflection of the diaphragm arranged so as to surround the weight body, it is possible to perform detection with relatively high sensitivity. However, since the periphery of the diaphragm is fixed to the device housing by the pedestal, if any stress is applied to the device housing at the time of use, the stress is transmitted to the diaphragm through the pedestal and affects the detection result. There is.

  For example, if the device casing expands or contracts due to the temperature environment during use, the stress is transmitted to the diaphragm, which adversely affects the detection result. In addition, if the device housing is fixed with an adhesive or a screw in order to mount the device housing on some measurement object, stress may be applied to the device housing during the mounting, and the stress adversely affects the detection result. It will be.

  On the other hand, as disclosed in the above-mentioned Patent Document 3, when a supporting structure for supporting the weight body by the arm is employed, the root end portion of the arm is only fixed to the device housing, and thus the device housing. The adverse effect on the detection result based on the stress generated in the body is almost negligible. However, since the displacement of the weight body within the apparatus housing must be detected by the bending of the arm, efficient detection cannot be performed and the detection sensitivity cannot be denied.

  In the case of an angular velocity sensor, if the vibration of the weight body is transmitted to the device housing and leaks to the outside, the vibration mode of the weight body will be affected by the external environment at the time of use, which is also detected. The result will be adversely affected.

Therefore, an object of the present invention is to provide an inertial sensor capable of accurately detecting acceleration with high detection sensitivity without adversely affecting the detection result depending on the use environment.

(1) A first aspect of the present invention is an inertial sensor that detects acceleration acting in a predetermined coordinate axis direction or an angular velocity acting around a predetermined coordinate axis in an xyz three-dimensional coordinate system.
a first plate-like bridge portion that extends in the y-axis direction with a first longitudinal axis parallel to the y-axis as a central axis and has flexibility;
A second plate-like bridge portion that is connected directly or indirectly to the first plate-like bridge portion, extends in the x-axis direction with a second longitudinal axis parallel to the x-axis as a central axis, and has flexibility; ,
A weight body connected directly or indirectly to the second plate-like bridge portion;
An apparatus housing that houses the first plate-like bridge portion, the second plate-like bridge portion, and the weight body;
A fixing portion for fixing one end of the first plate-like bridge portion to the apparatus housing;
An element group for operation disposed at a predetermined position of the first plate-shaped bridge portion and a predetermined position of the second plate-shaped bridge portion;
A detection circuit for detecting the applied acceleration or angular velocity using the operating element group;
Provided,
The fixing portion fixes the root end portion of the first plate-like bridge portion to the apparatus housing, and the tip portion of the first plate-like bridge portion is directly or indirectly on the root end portion of the second plate-like bridge portion. A weight body is directly or indirectly connected to the tip of the second plate-like bridge portion, and an L-shaped structure is formed by the first plate-like bridge portion and the second plate-like bridge portion. The body is formed,
When an external force acts on the device housing, the weight body is configured to be displaced in the device housing due to the bending of the first plate-like bridge portion and the second plate-like bridge portion,
The operating element group includes a first root end side element group disposed in the vicinity of the root end portion of the first plate-shaped bridge portion, and a first element disposed in the vicinity of the tip portion of the first plate-shaped bridge portion. The tip portion side element group, the second root end side element group disposed in the vicinity of the root end portion of the second plate-like bridge portion, and the tip end portion of the second plate-like bridge portion. A second tip side element group,
The first reference region, the second reference region, and the third reference region on the surface in the vicinity of the root end portion of the first plate-like bridge portion, on the surface in the vicinity of the tip portion of the first plate-like bridge portion, The fourth reference region, the fifth reference region, and the sixth reference region are arranged on the surface in the vicinity of the root end portion of the second plate-like bridge portion, the seventh reference region, the eighth reference region, and the ninth reference region. When the reference area is defined on the surface near the tip of the second plate-like bridge portion, the tenth reference area, the eleventh reference area, and the twelfth reference area, respectively,
The first root end side element group includes at least a first attribute element arranged in the first reference region and a third attribute element arranged in the third reference region, and the first tip portion The side element group has at least a fourth attribute element arranged in the fourth reference region and a sixth attribute element arranged in the sixth reference region,
The second root end side element group includes at least a seventh attribute element arranged in the seventh reference region and a ninth attribute element arranged in the ninth reference region, and the second tip portion The side element group has at least a tenth attribute element arranged in the tenth reference region and a twelfth attribute element arranged in the twelfth reference region,
The second reference region and the fifth reference region are respectively defined such that the orthogonal projection image onto the xy plane is located on the projection image of the first longitudinal axis, and the eighth reference region and the eleventh reference region are The reference areas are respectively defined such that the orthographic projection image on the xy plane is located on the projection image of the second longitudinal axis,
Considering the bent structure of the L-shaped structure, when defining the inside and outside of the first plate-like bridge portion and the second plate-like bridge portion,
The first reference region is defined at a position where the orthogonal projection image onto the xy plane is adjacent to the inside of the projection image of the second reference region, and the third reference region is an orthogonal projection image onto the xy plane. Defined at a position adjacent to the outside of the projected image of the second reference region,
The fourth reference area is defined at a position where the orthogonal projection image onto the xy plane is adjacent to the inside of the projection image of the fifth reference area, and the sixth reference area has an orthogonal projection image onto the xy plane. Defined at a position adjacent to the outside of the projected image of the fifth reference region,
The seventh reference region is defined at a position where the orthographic projection image onto the xy plane is adjacent to the inside of the projection image of the eighth reference region, and the ninth reference region has an orthographic projection image onto the xy plane. Defined at a position adjacent to the outside of the projected image of the eighth reference region,
The tenth reference region is defined at a position where the orthogonal projection image onto the xy plane is adjacent to the inside of the projection image of the eleventh reference region, and the twelfth reference region is an orthogonal projection image onto the xy plane. The eleventh reference area is defined at a position adjacent to the outside of the projected image.

(2) According to a second aspect of the present invention, in the inertial sensor according to the first aspect described above,
Each element constituting the operating element group is configured by a detection element that electrically detects the stress acting in the longitudinal direction of the plate-like bridge portion at each arrangement position,
The detection circuit detects acceleration acting in a predetermined coordinate axis direction based on the detection result of the detection element.

(3) According to a third aspect of the present invention, in the inertial sensor according to the second aspect described above,
Each detection element constituting the operating element group is constituted by a piezoresistive element arranged along the longitudinal direction of the plate-like bridge portion,
The detection circuit detects an acceleration acting in a predetermined coordinate axis direction based on an output of a bridge circuit using a piezoresistive element.

(4) A fourth aspect of the present invention is the inertial sensor according to the third aspect described above,
The detection circuit uses the bridge circuit having the first attribute element and the sixth attribute element as the first opposite side, and the third attribute element and the fourth attribute element as the second opposite side, and an acceleration αx applied in the x-axis direction. Detecting acceleration αy acting in the y-axis direction by a bridge circuit having the seventh attribute element and the twelfth attribute element as the first opposite side and the ninth attribute element and the tenth attribute element as the second opposite side It is what you do.

(5) A fifth aspect of the present invention is the inertial sensor according to the third aspect described above,
The detection circuit calculates an acceleration αx applied in the x-axis direction by a bridge circuit having the ninth attribute element and the twelfth attribute element as the first opposite side and the seventh attribute element and the tenth attribute element as the second opposite side. Detecting acceleration αy acting in the y-axis direction by a bridge circuit having the first attribute element and the fourth attribute element as the first opposite side and the third attribute element and the sixth attribute element as the second opposite side It is what you do.

(6) According to a sixth aspect of the present invention, in the inertial sensor according to the second aspect described above,
Each detection element constituting the operation element group is constituted by a piezoelectric element that generates a positive or negative charge according to the stretching stress along the longitudinal direction of the plate-like bridge portion,
The detection circuit detects an acceleration acting in a predetermined coordinate axis direction by performing addition / subtraction on the generated charges of each piezoelectric element.

(7) A seventh aspect of the present invention is the inertial sensor according to the sixth aspect described above,
The detection circuit determines x based on the difference between the sum of the charge generated by the first attribute element and the charge generated by the sixth attribute element and the sum of the charge generated by the third attribute element and the charge generated by the fourth attribute element. The acceleration αx acting in the axial direction is detected, and the sum of the generated charge of the seventh attribute element and the generated charge of the twelfth attribute element, and the sum of the generated charge of the ninth attribute element and the generated charge of the tenth attribute element, The acceleration αy acting in the y-axis direction is detected based on the difference between.

(8) An eighth aspect of the present invention is the inertial sensor according to the sixth aspect described above,
The detection circuit determines x based on the difference between the sum of the generated charge of the ninth attribute element and the generated charge of the twelfth attribute element and the sum of the generated charge of the seventh attribute element and the generated charge of the tenth attribute element. The acceleration αx acting in the axial direction is detected, the sum of the charge generated by the first attribute element and the charge generated by the fourth attribute element, and the sum of the charge generated by the third attribute element and the charge generated by the sixth attribute element The acceleration αy acting in the y-axis direction is detected based on the difference between.

(9) According to a ninth aspect of the present invention, in the inertial sensor according to the first aspect described above,
The individual elements constituting the operating element group are plate-like elements at each arrangement position based on a detection element that electrically detects the stress acting in the longitudinal direction of the plate-like bridge portion at each arrangement position or a given electrical signal. It is composed of a drive element that applies stress in the longitudinal direction to the bridge part,
The detection circuit gives an AC drive signal to the drive element, and in the state where the weight body is vibrated in the first axial direction, the first weight is applied to the weight body based on the detection result of the detection element. The Coriolis force acting in the second axial direction perpendicular to the axis is obtained, and the angular velocity acting around the third axis perpendicular to both the first axis and the second axis is detected based on the Coriolis force. It is what I did.

(10) According to a tenth aspect of the present invention, in the inertial sensor according to the ninth aspect described above,
Each drive element constituting the operating element group is configured by a piezoelectric element that applies a stretching stress along the longitudinal direction to the plate-like bridge portion according to a given AC drive signal,
Each detection element constituting the operation element group is constituted by a piezoelectric element that generates a positive or negative charge according to the stretching stress along the longitudinal direction of the plate-like bridge portion,
The detection circuit gives an alternating current drive signal having a predetermined phase to the piezoelectric element constituting the drive element, thereby causing the weight body to vibrate in the first axis direction, and performing addition / subtraction on the generated charge of the piezoelectric element constituting the detection element. Thus, the Coriolis force acting on the weight body in the second axial direction is obtained.

(11) An eleventh aspect of the present invention is the inertial sensor according to the tenth aspect described above,
The detection circuit applies an AC drive signal having a first phase to the first attribute element and the sixth attribute element, and outputs a second phase opposite to the first phase to the third attribute element and the fourth attribute element. By providing an AC drive signal having a phase, an x-axis excitation function for vibrating the weight body in the x-axis direction and an AC drive signal having a third phase in the seventh attribute element and the twelfth attribute element are provided. Y-axis excitation function for vibrating the weight body in the y-axis direction by applying an AC drive signal having a fourth phase opposite to the third phase to the ninth attribute element and the tenth attribute element And at least one of the excitation functions.

(12) According to a twelfth aspect of the present invention, in the inertial sensor according to the tenth aspect described above,
The detection circuit applies an AC drive signal having a first phase to the ninth attribute element and the twelfth attribute element, and outputs a second phase opposite to the first phase to the seventh attribute element and the tenth attribute element. By providing an AC drive signal having a phase, an x-axis excitation function for vibrating the weight body in the x-axis direction, and an AC drive signal having a third phase in the first attribute element and the fourth attribute element are provided. Y-axis excitation function for vibrating the weight body in the y-axis direction by applying an AC drive signal having a fourth phase opposite to the third phase to the third attribute element and the sixth attribute element And at least one of the excitation functions.

(13) A thirteenth aspect of the present invention is the inertial sensor according to the eleventh or twelfth aspect described above,
The detection circuit is based on a difference between the sum of the generated charge of the first attribute element and the generated charge of the sixth attribute element and the sum of the generated charge of the third attribute element and the generated charge of the fourth attribute element. X-axis detection function for detecting the Coriolis force fx acting on the weight body in the x-axis direction, the sum of the charge generated by the seventh attribute element and the charge generated by the twelfth attribute element, and the generation of the ninth attribute element A y-axis detection function for detecting a Coriolis force fy acting on the weight body in the y-axis direction based on the difference between the charge and the sum of the charges generated by the tenth attribute element. It is made to have.

(14) According to a fourteenth aspect of the present invention, in the inertial sensor according to the eleventh or twelfth aspect described above,
Based on the difference between the sum of the generated charge of the ninth attribute element and the generated charge of the twelfth attribute element and the sum of the generated charge of the seventh attribute element and the generated charge of the tenth attribute element, X-axis detection function for detecting the Coriolis force fx acting on the weight body in the x-axis direction, the sum of the charge generated by the first attribute element and the charge generated by the fourth attribute element, and the generation of the third attribute element A y-axis detection function for detecting a Coriolis force fy acting on the weight body in the y-axis direction based on the difference between the charge and the sum of the charges generated by the sixth attribute element. It is made to have.

(15) According to a fifteenth aspect of the present invention, in the inertial sensor according to the first aspect described above,
The first root end side element group further includes a second attribute element arranged in the second reference region, and the first tip end side element group is arranged in the fifth reference region. The device further includes an attribute element, the second root end side element group further includes an eighth attribute element disposed in the eighth reference region, and the second tip end side element group is the eleventh reference. It further has an eleventh attribute element arranged in the region.

(16) According to a sixteenth aspect of the present invention, in the inertial sensor according to the fifteenth aspect described above,
Each element constituting the operating element group is configured by a detection element that electrically detects the stress acting in the longitudinal direction of the plate-like bridge portion at each arrangement position,
The detection circuit detects acceleration acting in a predetermined coordinate axis direction based on the detection result of the detection element.

(17) According to a seventeenth aspect of the present invention, in the inertial sensor according to the sixteenth aspect described above,
Each detection element constituting the operating element group is constituted by a piezoresistive element arranged along the longitudinal direction of the plate-like bridge portion,
The detection circuit detects an acceleration acting in a predetermined coordinate axis direction based on an output of a bridge circuit using a piezoresistive element.

(18) According to an eighteenth aspect of the present invention, in the inertial sensor according to the seventeenth aspect described above,
The detection circuit uses the bridge circuit having the first attribute element and the sixth attribute element as the first opposite side, and the third attribute element and the fourth attribute element as the second opposite side, and an acceleration αx applied in the x-axis direction. Detecting acceleration αy acting in the y-axis direction by a bridge circuit having the seventh attribute element and the twelfth attribute element as the first opposite side and the ninth attribute element and the tenth attribute element as the second opposite side Then, the acceleration αz acting in the z-axis direction is detected by a bridge circuit in which the fifth attribute element and the eleventh attribute element are the first opposite sides and the second attribute element and the eighth attribute element are the second opposite sides. It is what I did.

(19) According to a nineteenth aspect of the present invention, in the inertial sensor according to the seventeenth aspect described above,
The detection circuit calculates an acceleration αx applied in the x-axis direction by a bridge circuit having the ninth attribute element and the twelfth attribute element as the first opposite side and the seventh attribute element and the tenth attribute element as the second opposite side. Detecting acceleration αy acting in the y-axis direction by a bridge circuit having the first attribute element and the fourth attribute element as the first opposite side and the third attribute element and the sixth attribute element as the second opposite side In addition, one side formed by connecting the fourth attribute element, the fifth attribute element, and the sixth attribute element in series with one side formed by connecting the tenth attribute element, the eleventh attribute element, and the twelfth attribute element in series. The second side is one side formed by connecting the first attribute element, the second attribute element, and the third attribute element in series and the one side formed by connecting the seventh attribute element, the eighth attribute element, and the ninth attribute element in series. The acceleration αz acting in the z-axis direction is detected by a bridge circuit opposite to It is obtained by the.

(20) According to a twentieth aspect of the present invention, in the inertial sensor according to the sixteenth aspect described above,
Each detection element constituting the operation element group is constituted by a piezoelectric element that generates a positive or negative charge according to the stretching stress along the longitudinal direction of the plate-like bridge portion,
The detection circuit detects an acceleration acting in a predetermined coordinate axis direction by performing addition / subtraction on the generated charges of each piezoelectric element.

(21) According to a twenty-first aspect of the present invention, in the inertial sensor according to the twentieth aspect described above,
The detection circuit determines x based on the difference between the sum of the charge generated by the first attribute element and the charge generated by the sixth attribute element and the sum of the charge generated by the third attribute element and the charge generated by the fourth attribute element. The acceleration αx acting in the axial direction is detected, and the sum of the generated charge of the seventh attribute element and the generated charge of the twelfth attribute element, and the sum of the generated charge of the ninth attribute element and the generated charge of the tenth attribute element, , The acceleration αy acting in the y-axis direction is detected based on the difference between and the sum of the charge generated by the fifth attribute element and the charge generated by the eleventh attribute element, the charge generated by the second attribute element, and the eighth attribute element. The acceleration αz acting in the z-axis direction is detected based on the difference between the sum and the generated charge.

(22) According to a twenty-second aspect of the present invention, in the inertial sensor according to the twentieth aspect described above,
The detection circuit determines x based on the difference between the sum of the generated charge of the ninth attribute element and the generated charge of the twelfth attribute element and the sum of the generated charge of the seventh attribute element and the generated charge of the tenth attribute element. The acceleration αx acting in the axial direction is detected, the sum of the charge generated by the first attribute element and the charge generated by the fourth attribute element, and the sum of the charge generated by the third attribute element and the charge generated by the sixth attribute element , The acceleration αy acting in the y-axis direction is detected based on the difference between and the fourth attribute element, the fifth attribute element, the sixth attribute element, the tenth attribute element, the eleventh attribute element, and the twelfth attribute element. Based on the difference between the sum of charges and the sum of generated charges of the first attribute element, the second attribute element, the third attribute element, the seventh attribute element, the eighth attribute element, and the ninth attribute element, in the z-axis direction The acceleration .alpha.z acting on is detected.

(23) According to a twenty-third aspect of the present invention, in the inertial sensor according to the fifteenth aspect described above,
The individual elements constituting the operating element group are plate-like elements at each arrangement position based on a detection element that electrically detects the stress acting in the longitudinal direction of the plate-like bridge portion at each arrangement position or a given electrical signal. It is composed of a drive element that applies stress in the longitudinal direction to the bridge part,
The detection circuit gives an AC drive signal to the drive element, and in the state where the weight body is vibrated in the first axial direction, the first weight is applied to the weight body based on the detection result of the detection element. The Coriolis force acting in the second axial direction perpendicular to the axis is obtained, and the angular velocity acting around the third axis perpendicular to both the first axis and the second axis is detected based on the Coriolis force. It is what I did.

(24) According to a twenty-fourth aspect of the present invention, in the inertial sensor according to the twenty-third aspect described above,
Each drive element constituting the operating element group is configured by a piezoelectric element that applies a stretching stress along the longitudinal direction to the plate-like bridge portion according to a given AC drive signal,
Each detection element constituting the operation element group is constituted by a piezoelectric element that generates a positive or negative charge according to the stretching stress along the longitudinal direction of the plate-like bridge portion,
The detection circuit gives an alternating current drive signal having a predetermined phase to the piezoelectric element constituting the drive element, thereby causing the weight body to vibrate in the first axis direction, and performing addition / subtraction on the generated charge of the piezoelectric element constituting the detection element. Thus, the Coriolis force acting on the weight body in the second axial direction is obtained.

(25) According to a twenty-fifth aspect of the present invention, in the inertial sensor according to the twenty-fourth aspect described above,
The detection circuit applies an AC drive signal having a first phase to the first attribute element and the sixth attribute element, and outputs a second phase opposite to the first phase to the third attribute element and the fourth attribute element. By providing an AC drive signal having a phase, an x-axis excitation function for vibrating the weight body in the x-axis direction and an AC drive signal having a third phase in the seventh attribute element and the twelfth attribute element are provided. Y-axis excitation function for vibrating the weight body in the y-axis direction by applying an AC drive signal having a fourth phase opposite to the third phase to the ninth attribute element and the tenth attribute element And an AC drive signal having a fifth phase is applied to the fifth attribute element and the eleventh attribute element, and a sixth phase opposite to the fifth phase is applied to the second attribute element and the eighth attribute element. A z-axis excitation function that vibrates the weight body in the z-axis direction by applying an alternating drive signal having at least One of those was to have the excitation function.

(26) According to a twenty-sixth aspect of the present invention, in the inertial sensor according to the twenty-fourth aspect described above,
The detection circuit applies an AC drive signal having a first phase to the ninth attribute element and the twelfth attribute element, and outputs a second phase opposite to the first phase to the seventh attribute element and the tenth attribute element. By providing an AC drive signal having a phase, an x-axis excitation function for vibrating the weight body in the x-axis direction, and an AC drive signal having a third phase in the first attribute element and the fourth attribute element are provided. Y-axis excitation function for vibrating the weight body in the y-axis direction by applying an AC drive signal having a fourth phase opposite to the third phase to the third attribute element and the sixth attribute element And an AC drive signal having a fifth phase is applied to each of the fourth attribute element, the fifth attribute element, the sixth attribute element, the tenth attribute element, the eleventh attribute element, and the twelfth attribute element, and the first attribute Each of the element, the second attribute element, the third attribute element, the seventh attribute element, the eighth attribute element, and the ninth attribute element By providing an AC drive signal having a sixth phase opposite to the fifth phase, the z-axis excitation function for vibrating the weight body in the z-axis direction and at least one excitation function are provided. It is a thing.

(27) According to a twenty-seventh aspect of the present invention, in the inertial sensor according to the twenty-fifth or twenty-sixth aspect described above,
The detection circuit is based on a difference between the sum of the generated charge of the first attribute element and the generated charge of the sixth attribute element and the sum of the generated charge of the third attribute element and the generated charge of the fourth attribute element. X-axis detection function for detecting the Coriolis force fx acting on the weight body in the x-axis direction, the sum of the charge generated by the seventh attribute element and the charge generated by the twelfth attribute element, and the generation of the ninth attribute element A y-axis detection function for detecting a Coriolis force fy acting on the weight body in the y-axis direction based on a difference between a charge and a sum of charges generated by the tenth attribute element, and generation of a fifth attribute element Based on the difference between the sum of the charge and the generated charge of the eleventh attribute element, and the sum of the generated charge of the second attribute element and the generated charge of the eighth attribute element, in the z-axis direction with respect to the weight body A z-axis detection function for detecting the applied Coriolis force fz, and at least one of the detection functions. It is intended.

(28) According to a twenty-eighth aspect of the present invention, in the inertial sensor according to the twenty-fifth or twenty-sixth aspect described above,
Based on the difference between the sum of the generated charge of the ninth attribute element and the generated charge of the twelfth attribute element and the sum of the generated charge of the seventh attribute element and the generated charge of the tenth attribute element, X-axis detection function for detecting the Coriolis force fx acting on the weight body in the x-axis direction, the sum of the charge generated by the first attribute element and the charge generated by the fourth attribute element, and the generation of the third attribute element A y-axis detection function for detecting the Coriolis force fy acting on the weight body in the y-axis direction based on the difference between the charge and the sum of the charges generated by the sixth attribute element; the fourth attribute element; Total sum of generated charges of 5 attribute element, 6th attribute element, 10th attribute element, 11th attribute element, 12th attribute element, 1st attribute element, 2nd attribute element, 3rd attribute element, 7th attribute element , The eighth attribute element, and the ninth attribute element based on the difference between the total generated charges and the z axis direction relative to the weight body It is obtained so as to have a z-axis detecting function for detecting a Coriolis force fz exerted, at least one detection of the.

(29) According to a twenty-ninth aspect of the present invention, in the inertial sensor according to the first to twenty-eighth aspects described above,
The orthographic projection image on the xy plane of the operating element group arranged in the first plate-like bridge portion has a pattern that is line symmetric with respect to the projection image of the first longitudinal axis, and the second plate-like bridge The orthographic projection image on the xy plane of the operation element group arranged in the unit has a pattern that is line symmetric with respect to the projection image of the second longitudinal axis.

(30) In a 30th aspect of the present invention, in the inertial sensor according to the first to 29th aspects described above,
The tip of the first plate bridge and the root end of the second plate bridge so that the first plate bridge and the second plate bridge are arranged in an L shape. Are connected via an intermediate connection,
The tip of the second plate-shaped bridge portion and the corner of the weight body are connected via the weight connection portion so that the weight body is arranged beside the second plate-shaped bridge portion. ,
The lower surface of the fixed portion is fixed to the upper surface of the bottom plate of the apparatus housing, and the first plate-shaped bridge portion, the second plate-shaped bridge portion, and the weight body of the device housing are in a state where no external force acts. It is designed to be suspended in the air above the bottom plate.

(31) According to a thirty-first aspect of the present invention, in the inertial sensor according to the thirtieth aspect described above,
An intermediate connecting portion projecting outward from the side surface of the tip portion of the first plate-like bridge portion and an eaves structure portion projecting outward from the side surface of the root end portion of the second plate-like bridge portion; Have
The weight connection part has a ridge structure part protruding outward from the side surface of the tip part of the second plate-like bridge part.

(32) According to a thirty-second aspect of the present invention, in the inertial sensor according to the thirtieth or thirty-first aspect described above,
The fixing portion is constituted by a fixing portion plate member extending along a fixing portion longitudinal axis parallel to the x-axis, and a root end portion of the first plate-like bridge portion is provided at one end of the fixing portion plate member. Is fixed,
The structure constituted by the plate member for the fixing portion, the first plate-like bridge portion, and the second plate-like bridge portion is such that the projected image on the xy plane has a “U” shape. A character-like structure is formed, and a plate-like weight is arranged in an inner region surrounded by the U-shaped structure.

(33) According to a thirty-third aspect of the present invention, in the inertial sensor according to the thirtieth or thirty-first aspect described above,
The fixing portion is constituted by an annular structure, and the first plate-like bridge portion, the second plate-like bridge portion and the weight body are arranged in an inner region surrounded by the annular structure, and the device When an external force of a predetermined magnitude or more is applied to the housing, the member arranged in the inner region comes into contact with the inner surface of the annular structure so that the displacement of the member is controlled within a predetermined range. It is what has been done.

(34) According to a thirty-fourth aspect of the present invention, in the inertial sensor according to the thirty-third aspect described above,
The role of the fixed part and the weight body is reversed, the annular structure functioning as the fixed part in the inertial sensor is functioned as the weight body, and the plate-shaped body functioning as the weight body in the inertial sensor The lower surface of the plate-like body is fixed to the upper surface of the bottom plate of the device housing, and the annular structure is suspended above the bottom plate of the device housing in a state where no external force is applied. It is intended to become.

(35) According to a thirty-fifth aspect of the present invention, in the inertial sensor according to the twentieth to twenty-second or twenty-fourth to twenty-eighth aspects described above,
A lower layer electrode formed in layers on the surfaces of the first plate-shaped bridge portion and the second plate-shaped bridge portion, and a layer formed on the surface of the lower layer electrode, and generates polarization in the vertical direction based on expansion and contraction in the layer direction A piezoelectric element group functioning as an individual detection element or drive element is configured by a piezoelectric body and an upper electrode group composed of a plurality of upper layer electrodes locally formed on the surface of the piezoelectric body. Is.

(36) The thirty-sixth aspect of the present invention is the inertial sensor according to the thirty-fifth aspect described above,
A lower layer electrode is formed on the upper surface of the first plate-like bridge portion and the second plate-like bridge portion, and a piezoelectric body is formed on the upper surface of the lower layer electrode,
The upper layer electrodes constituting the first attribute element to the twelfth attribute element are all formed on the upper surface of each plate-like bridge portion via the lower layer electrode and the piezoelectric body.

(37) According to a thirty-seventh aspect of the present invention, in the inertial sensor according to the thirty-fifth aspect described above,
The lower layer electrode is formed on the side surface as well as the upper surface of the first plate-like bridge portion and the second plate-like bridge portion, and the piezoelectric body is formed on the surface of the lower layer electrode,
Upper layer electrodes constituting the second attribute element, the fifth attribute element, the eighth attribute element, and the eleventh attribute element are formed on the upper surface of each plate-like bridge portion via the lower layer electrode and the piezoelectric body,
The upper layer electrodes constituting the first attribute element, the third attribute element, the fourth attribute element, the sixth attribute element, the seventh attribute element, the ninth attribute element, the tenth attribute element, and the twelfth attribute element are each a plate-like bridge. It is formed on the side surface of the part via a lower layer electrode and a piezoelectric body.

(38) The thirty-eighth aspect of the present invention is the inertial sensor according to the thirty-fifth aspect described above,
The lower layer electrode is formed on the side surface as well as the upper surface of the first plate-like bridge portion and the second plate-like bridge portion, and the piezoelectric body is formed on the surface of the lower layer electrode,
Upper layer electrodes constituting the second attribute element, the fifth attribute element, the eighth attribute element, and the eleventh attribute element are formed on the upper surface of each plate-like bridge portion via the lower layer electrode and the piezoelectric body,
The upper layer electrodes constituting the first attribute element, the third attribute element, the fourth attribute element, the sixth attribute element, the seventh attribute element, the ninth attribute element, the tenth attribute element, and the twelfth attribute element are each a plate-like bridge. It is formed from the upper surface to the side surface of the portion via the lower layer electrode and the piezoelectric body.

(39) A thirty-ninth aspect of the present invention provides a plurality of n sets of inertial sensors according to the ninth to fourteenth or twenty-third to twenty-eighth aspects described above, around a predetermined coordinate axis in the XYZ three-dimensional coordinate system or An angular velocity detection device that detects an angular velocity acting around an axis obtained by rotating the coordinate axis by a predetermined angle around the origin,
The n sets of inertial sensors are arranged so that their x-axis, y-axis, and z-axis are parallel to the X-axis, Y-axis, and Z-axis in the XYZ three-dimensional coordinate system defined for the angular velocity detection device. And
Based on the angular velocity around the predetermined axis detected by the detection circuit of each of the n sets of inertial sensors, it acts around a predetermined coordinate axis in the XYZ three-dimensional coordinate system or around an axis obtained by rotating the coordinate axis by a predetermined angle around the origin. Further, an angular velocity output unit for outputting the detected value of the angular velocity is provided.

(40) According to a 40th aspect of the present invention, in the angular velocity detection device according to the 39th aspect described above,
The first coordinate axis in the XYZ three-dimensional coordinate system is set as a common vibration axis, the second coordinate axis is set as a common Coriolis force detection axis, the third coordinate axis is set as a common angular velocity detection axis,
Each of the n sets of inertial sensors obtains the Coriolis force acting in the common Coriolis force detection axis direction in a state where the respective weight bodies vibrate in the common vibration axis direction, and is parallel to the common angular velocity detection axis. Detect the angular velocity acting around the axis,
The angular velocity output unit outputs an average value for any one or several of the angular velocities detected by each of the n sets of inertial sensors as a detected value of the angular velocity acting around the common angular velocity detection axis. is there.

(41) According to a 41st aspect of the present invention, in the angular velocity detection device according to the 39th aspect described above,
The first coordinate axis in the XYZ three-dimensional coordinate system is set as a common vibration axis,
Each of the n sets of inertial sensors oscillates the respective weight bodies in the common vibration axis direction, and obtains the Coriolis force acting in the second coordinate axis direction, thereby obtaining an axis parallel to the third coordinate axis. Detecting each acting angular velocity, and detecting each acting angular velocity around an axis parallel to the second coordinate axis by obtaining a Coriolis force acting in the third coordinate axis direction,
The angular velocity output unit calculates an average value of one or several angular velocities acting around an axis parallel to the third coordinate axis among the angular velocities detected by each of the n sets of inertial sensors around the third coordinate axis. Is detected as the detected value of the angular velocity acting on the axis, and the average value of any one or some of the angular velocities acting around the axis parallel to the second coordinate axis is detected as the angular velocity acting around the second coordinate axis. It is output as a value.

(42) According to a forty-second aspect of the present invention, in the angular velocity detection device according to the thirty-ninth aspect described above,
For the inertial sensors belonging to the first group among the n groups of inertial sensors, the first coordinate axis in the XYZ three-dimensional coordinate system is the vibration axis, and both the second and third coordinate axes are the Coriolis force detection axes. For the inertial sensors belonging to the second group, the second coordinate axis in the XYZ three-dimensional coordinate system is defined as the vibration axis, and the third coordinate axis is defined as the Coriolis force detection axis.
Each of the n sets of inertial sensors obtains the Coriolis force acting in the direction of each Coriolis force detection axis in the state where each weight body vibrates in each vibration axis direction, and around each axis parallel to each angular velocity detection axis. Detecting each acting angular velocity,
The angular velocity output unit outputs a detected value of the angular velocity acting around the second coordinate axis and the angular velocity acting around the third coordinate axis based on the angular velocity detected by the inertial sensor belonging to the first group, and outputs to the second group Based on the angular velocity detected by the associated inertial sensor, a detected value of the angular velocity acting around the first coordinate axis is output.

(43) According to a 43rd aspect of the present invention, in the angular velocity detection device according to the 39th aspect described above,
Obtained by rotating the X axis 45 ° counterclockwise about the origin on the XY plane and rotating the Y axis 45 ° counterclockwise about the origin on the XY plane. When defining the Y 'axis
Each of the n sets of inertial sensors has both an x-axis excitation function for vibrating each weight body in the x-axis direction and an y-axis excitation function for vibrating in the y-axis direction.
Among the n groups of inertial sensors, the inertial sensors belonging to the first group combine the x-axis excitation function and the y-axis excitation function, and in the state where the weight body is vibrated in the X′-axis direction, By obtaining the Coriolis force acting in the Z-axis direction on the weight body, the angular velocity ωY ′ acting around the axis parallel to the Y′-axis is detected,
Among the n groups of inertial sensors, the inertial sensors belonging to the second group combine the x-axis excitation function and the y-axis excitation function, and in the state where the weight body is vibrated in the Y′-axis direction, By obtaining the Coriolis force acting in the Z-axis direction on the weight body, the angular velocity ωX ′ acting around the axis parallel to the X′-axis is detected,
The angular velocity output unit has a function of outputting the angular velocity ωX ′ and the angular velocity ωY ′, or the angular velocity ωX acting around the X axis and the angular velocity ωY acting around the Y axis obtained based on the angular velocity ωX ′ and the angular velocity ωY ′. Detection device.

(44) According to a 44th aspect of the present invention, in the angular velocity detection device according to the 43rd aspect described above,
At least one of the inertial sensor belonging to the first group and the inertial sensor belonging to the second group acted in the x-axis detection function for detecting the Coriolis force acting on the weight body in the x-axis direction and in the y-axis direction. It has both y-axis detection function that detects Coriolis force, and by combining these x-axis detection function and y-axis detection function, it can be used in the Y'-axis direction or X'-axis direction with respect to the weight body. By detecting the angular velocity ωZ acting around the Z axis by obtaining the Coriolis force acting on
An angular velocity detection device, wherein the angular velocity output unit has a function of outputting three-axis components of angular velocities ωX ′, ωY ′, and ωZ or three-axis components of angular velocities ωX, ωY, and ωZ.

(45) According to a 45th aspect of the present invention, in the angular velocity detection device according to the 44th aspect described above,
By setting n = 2, an inertial sensor belonging to the first group and an inertial sensor belonging to the second group are provided,
The two inertial sensors are arranged adjacent to each other along the X axis,
The reciprocating motion of the weight body in one inertial sensor in the positive and negative directions and the reciprocating motion of the weight body in the other inertial sensor in the positive and negative directions have the same period and The control is performed so as to achieve the same phase.

(46) According to a 46th aspect of the present invention, in the angular velocity detection device according to the 45th aspect described above,
One inertial sensor is arranged in one space with the YZ plane as a boundary surface, and the other inertial sensor is arranged in the other space, and these two inertial sensors have a plane symmetrical structure with respect to the YZ plane. It is.

(47) According to a 47th aspect of the present invention, in the angular velocity detection device according to the 44th aspect described above,
By setting n = 4, the first inertial sensor, the second inertial sensor, the third inertial sensor, and the fourth inertial sensor are provided.
The orthographic projection image of the first inertial sensor on the XY plane is located in the first quadrant, the orthographic projection image of the second inertial sensor on the XY plane is located in the second quadrant, and the third inertial sensor The orthographic projection image on the XY plane is positioned in the third quadrant, and the orthographic projection image of the fourth inertial sensor on the XY plane is positioned in the fourth quadrant,
The first inertial sensor and the third inertial sensor belong to the first group, the second inertial sensor and the fourth inertial sensor belong to the second group,
The reciprocating motion of the weight body in the first inertial sensor in the positive and negative directions is the same as the reciprocating motion of the weight body in the third inertial sensor in the positive and negative directions. Reciprocating in the positive and negative directions of the Y ′ axis of the weight body in the second inertial sensor and in the positive and negative directions of the Y ′ axis of the weight body in the fourth inertial sensor. The reciprocating motion has the same period and opposite phase, and the reciprocating motion of the weight body in the first inertial sensor in the positive and negative directions and the Y ′ axis of the weight body in the second inertial sensor. The reciprocating motion in the positive and negative directions is controlled so as to have the same period and the same phase.

(48) According to a 48th aspect of the present invention, in the angular velocity detection device according to the 44th aspect described above,
By setting n = 4, the first inertial sensor, the second inertial sensor, the third inertial sensor, and the fourth inertial sensor are provided.
The orthographic projection image of the first inertial sensor on the XY plane is located in the first quadrant, the orthographic projection image of the second inertial sensor on the XY plane is located in the second quadrant, and the third inertial sensor The orthographic projection image on the XY plane is positioned in the third quadrant, and the orthographic projection image of the fourth inertial sensor on the XY plane is positioned in the fourth quadrant,
The second inertia sensor and the fourth inertia sensor belong to the first group, and the first inertia sensor and the third inertia sensor belong to the second group,
The reciprocating motion of the weight body in the first inertial sensor in the positive and negative directions and the reciprocating motion of the weight body in the third inertial sensor in the positive and negative directions are the same. Periodic and anti-phase, reciprocating motion of the weight body in the second inertial sensor in the positive and negative directions, and weighting mechanism in the fourth inertial sensor in the positive and negative directions of the X 'axis The reciprocating motion has the same period and opposite phase, and the reciprocating motion of the weight body in the first inertial sensor in the positive and negative directions and the weight of the second inertial sensor in the X ′ axis The reciprocating motion in the positive and negative directions is controlled so as to have the same period and the same phase.

(49) According to a 49th aspect of the present invention, in the angular velocity detection device according to the 47th or 48th aspect described above,
The first inertial sensor and the second inertial sensor have a plane symmetry structure with the YZ plane as a symmetry plane, and the third inertial sensor and the fourth inertial sensor have a plane symmetry with the YZ plane as a symmetry plane. The first inertia sensor and the fourth inertia sensor have a plane symmetry structure with the XZ plane as a symmetry plane, and the second inertia sensor and the third inertia sensor have an XZ plane as a symmetry plane. It is intended to form a plane symmetric structure.

(50) According to a 50th aspect of the present invention, in the angular velocity detection device according to the 43rd to 49th aspects described above,
The angular velocity output unit converts the angular velocity ωX ′ and the angular velocity ωY ′ into the geometric transformation equations “ωX = (1 / √2) · ωX ′ − (1 / √2) · ωY ′” and “ωY = (1 / The conversion based on the calculation based on √2) · ωX ′ + (1 / √2) · ωY ′ ”is performed to convert the angular velocity ωX acting around the X axis and the angular velocity ωY acting around the Y axis, respectively. It has a function of outputting the angular velocity ωX and the angular velocity ωY obtained by the processing.

(51) According to a 51st aspect of the present invention, in the angular velocity detection device according to the 45th aspect described above,
The root end portion of the first plate-like bridge portion of the first inertial sensor belonging to the first group and the root end portion of the first plate-like bridge portion of the second inertial sensor belonging to the second group are: It is designed to be connected to the fixed part through a common annular connection part.

(52) According to a 52nd aspect of the present invention, in the angular velocity detection device according to the 51st aspect described above,
The annular connecting portion has a first side and a second side extending in a direction parallel to the X axis as one opposite side, and a third side and a fourth side extending in a direction parallel to the Y axis as the other opposite side Has a rectangular shape,
The root end portion of the first plate-like bridge portion of the first inertial sensor and the root end portion of the first plate-like bridge portion of the second inertial sensor are connected to the first side of the annular connection portion. And the second side of the annular connecting portion is connected to the fixing portion via the fixing connecting portion,
The first inertial sensor is disposed in one space with the YZ plane as a boundary surface, and the second inertial sensor is disposed in the other space. Both the inertial sensors have a plane-symmetric structure with respect to the YZ plane, The connecting portion and the fixing connecting portion also have a plane symmetric structure with respect to the YZ plane.

(53) According to a 53rd aspect of the present invention, the inertial sensor according to the 16th to 22nd aspects described above is added to the angular velocity detection apparatus according to the 45th, 46th, 51st, and 52nd aspects described above. In addition to the angular velocity output unit, in addition to the angular velocity output unit, a composite detection value output unit having a function of outputting a detection value of acceleration detected by the third inertia sensor is provided,
Add three-axis component of acceleration αX ', αY', αZ or three-axis component of acceleration αX, αY, αZ to three-axis component of angular velocity ωX ', ωY', ωZ or three-axis component of angular velocity ωX, ωY, ωZ In addition, a composite detection device of angular velocity and acceleration capable of detecting a total of six axis components is configured.

(54) According to a 54th aspect of the present invention, in the composite detection device for angular velocity and acceleration according to the above-mentioned 53rd aspect,
A sealed structure having a sealed space inside and having a diaphragm formed on at least one surface;
A pressure detecting element that outputs an electrical signal corresponding to the deflection of the diaphragm portion caused by pressure applied from the outside;
A pressure detection circuit for detecting pressure based on the output signal of the pressure detection element;
A pressure sensor having
Angular velocity / acceleration / pressure can be detected in addition to angular velocity and acceleration by providing the composite detection value output unit with the function to output the detected pressure value detected by the pressure sensor. The combined detection device of
The sealing structure is supported in a suspended state in the apparatus housing by fixing one predetermined portion of the sealing structure to the apparatus housing via the fixing connection portion.

(55) According to a 55th aspect of the present invention, in the composite detection device for angular velocity, acceleration, and pressure according to the 54th aspect described above,
When the contour of the orthogonal projection image of the sealed space with respect to the upper surface of the diaphragm portion is a rectangle, and the four sides of the contour rectangle are defined as an upper side, a lower side, a left side, and a right side,
The pressure detecting element has a first piezoresistive element, a second piezoresistive element, a third piezoresistive element, and a fourth piezoresistive element formed on the upper surface of the diaphragm portion, and the first piezoresistive element Is arranged in the vicinity of the center of the upper side inside the outline rectangle so that the direction orthogonal to the upper side is the longitudinal direction, and the second piezoresistive element is orthogonal to the lower side near the center of the lower side inside the outline rectangle The third piezoresistive element is arranged in the vicinity of the center of the left side inside the outline rectangle so that the left side direction is the longitudinal direction, and the fourth piezoresistive element is It is arranged so that the direction of the right side is the longitudinal direction near the center of the right side inside the outline rectangle,
The pressure detection circuit outputs the bridge circuit having the first piezoresistive element and the second piezoresistive element as one opposite side and the third piezoresistive element and the fourth piezoresistive element as the other opposite side. Based on this, the pressure is detected.

(56) A fifty-sixth aspect of the present invention is the combined angular velocity / acceleration / pressure detection device according to the fifty-fourth or fifty-fifth aspect described above,
The hermetically sealed structure is constituted by an SOI substrate formed by laminating a first silicon layer, a silicon oxide layer, and a second silicon layer in order from the top to the bottom, and the inner surface of a groove dug in the upper surface of the second silicon layer And a sealed space is formed between the lower surface of the silicon oxide layer,
The upper part of the sealed space in the laminated body of the first silicon layer and the silicon oxide layer constitutes a diaphragm part, and the pressure detecting element is formed on the upper surface of the first silicon layer.

(57) According to a 57th aspect of the present invention, in the composite detection device for angular velocity, acceleration and pressure according to the 54th to 56th aspects described above,
With respect to the orthogonal projection image on the XY plane in the XYZ three-dimensional coordinate system, one of the projection images of the first inertia sensor and the second inertia sensor is located in the first quadrant and the other is located in the second quadrant. And one of the pressure sensors is located in the third quadrant, and the other is located in the fourth quadrant, and surrounds the entire circumference of the first inertia sensor, the second inertia sensor, the third inertia sensor, and the pressure sensor. A frame-shaped fixing part fixed to the body is provided.

  Since the inertial sensor according to the present invention employs a structure in which the weight body is supported by the L-shaped structure, even if some stress is applied to the apparatus housing at the time of use, the influence is exerted on the detection result. There is almost no. In addition, an operation element group is arranged in a unique reference region (eight unique or twelve unique locations where stress in a specific direction is confirmed to be concentrated) defined in the L-shaped structure. Therefore, it is possible to effectively detect the applied acceleration and angular velocity by detecting the stress generated in the reference region. For this reason, acceleration and angular velocity can be detected with high detection sensitivity.

  In addition, in the angular velocity detection device configured by using a plurality of sets of the inertial sensors, since the final detection value can be output using the detection results of the individual inertial sensors comprehensively, a more accurate detection value can be obtained. You will be able to get In particular, in some embodiments, the action of suppressing the vibration of the weight body from leaking to the outside of the device housing works, so that the vibration mode of the weight body is affected by the external environment during use. Therefore, a more accurate detection value can be obtained.

FIG. 2 is a plan view (FIG. (A)) of an acceleration sensor adopting a conventional diaphragm structure and a side sectional view (FIG. (B)) cut along the yz plane (hatching in FIG. It is given to clearly show the arrangement, not the cross section). FIG. 2 is a plan view (FIG. (A)) of a basic structure 100 constituting an inertial sensor according to a basic embodiment of the present invention, and a side sectional view (FIG. (B)) of cutting this along a yz plane. It is a top view which shows the fixed state with respect to the apparatus housing | casing of the basic structure 100 shown in FIG. 2 (The hatching area | region in a figure is for showing a fixing part and does not show a cross section.). It is a top view which shows 12 sets of reference region R1-R12 defined on the basic structure 100 shown in FIG. 2 (The hatching in a figure is attached in order to show arrangement | positioning of each reference region clearly, It does not show a cross section). FIG. 3 is a plan view showing an expansion / contraction state of each reference region R1 to R12 when a weight body 150 of the basic structure 100 shown in FIG. 2 generates a displacement Δx (+) in the x-axis positive direction. FIG. 3 is a plan view showing an expansion / contraction state of each reference region R1 to R12 when a weight 150 of the basic structure 100 shown in FIG. 2 generates a displacement Δy (+) in the y-axis positive direction. FIG. 3 is a plan view showing an expansion / contraction state of each reference region R1 to R12 when a weight 150 of the basic structure 100 shown in FIG. 2 generates a displacement Δz (+) in the z-axis positive direction. FIG. 8 is a table collectively showing the stretched states shown in FIGS. 5 to 7, where the symbol + indicates a stretched state, the symbol − indicates a contracted state, and the symbol 0 indicates a state in which no significant stretching occurs. The top view (figure (a)) of embodiment which comprised the inertial sensor which concerns on this invention using the piezoresistive element, and side sectional drawing (figure (b)) cut | disconnected this in the position shown by the cutting line 9b-9b (Hatching in FIG. 1 (a) is given to clearly show the arrangement of each piezoresistive element and does not show a cross section). It is a circuit diagram which shows an example of the detection circuit 500 utilized for embodiment shown in FIG. It is a circuit diagram which shows another example of the detection circuit 500 utilized for embodiment shown in FIG. It is a top view which shows the example which has arrange | positioned the several detection element in the same reference area (The hatching in a figure is attached in order to show arrangement | positioning of each detection element clearly, and does not show a cross section.) . FIG. 12 is a plan view showing an example of arrangement of the piezoresistive elements when the detection circuit shown in FIG. 11 is used in the embodiment shown in FIG. 9 (hatching in the figure is attached to clearly show the arrangement of the piezoresistive elements). It does not show a cross section). FIG. 2 is a plan view (FIG. (A)) of an embodiment in which an inertial sensor according to the present invention is configured using a piezoelectric element, and a side sectional view (FIG. (B)) cut at a position indicated by a cutting line 14b-14b. (The hatching in FIG. (A) is given to clearly show the arrangement of each piezoelectric element (upper electrode), and does not show a cross section). It is a circuit diagram which shows an example of the part which performs the detection process of the detection circuit 510 utilized for embodiment shown in FIG. It is a circuit diagram which shows another example of the part which performs the detection process of the detection circuit 510 utilized for embodiment shown in FIG. It is a sectional side view which shows the variation of the arrangement | positioning aspect of the piezoelectric element in the inertial sensor shown in FIG. It is a circuit diagram which shows an example of the part which performs the drive process of the detection circuit 510 utilized for embodiment shown in FIG. FIG. 15 is a circuit diagram showing another example of a portion that performs a driving process of the detection circuit 510 used in the embodiment shown in FIG. 14. It is a top view which shows the basic structure of the angular velocity detection apparatus comprised by providing two sets of inertial sensors shown in FIG. 14 (The hatching in a figure is attached in order to show the shape of a basic structure clearly. Does not show a cross section). 20 is a plan view showing the relationship between the XYZ three-dimensional coordinate system (global coordinate system) defined for the basic structure shown in FIG. 20 and the xyz three-dimensional coordinate system (local coordinate system) defined for each inertial sensor. It is a block diagram which shows a circuit. It is a top view which shows an example of the vibration aspect of the weight body of each inertial sensor in the angular velocity detection apparatus shown in FIG. It is a top view which shows another example of the vibration aspect of the weight body of each inertial sensor in the angular velocity detection apparatus shown in FIG. It is a top view which shows the basic structure of the angular velocity detection apparatus comprised by providing four sets of inertial sensors shown in FIG. 14 (The hatching in a figure is attached in order to show the shape of a basic structure clearly. Does not show a cross section). FIG. 24 is a plan view showing the relationship between the XYZ three-dimensional coordinate system (global coordinate system) defined for the basic structure and the xyz three-dimensional coordinate system (local coordinate system) defined for each inertial sensor. It is a block diagram which shows a circuit. It is a top view which shows an example of the vibration aspect of the weight body of each inertial sensor in the angular velocity detection apparatus shown in FIG. FIG. 25 is a plan view illustrating another example of the vibration mode of the weight body of each inertial sensor in the angular velocity detection device illustrated in FIG. 24. FIG. 21 is a plan view showing a state in which an X ′ axis and a Y ′ axis are defined for the basic structure shown in FIG. 20. FIG. 29 is a plan view showing a vibration direction along the X ′ axis and the Y ′ axis shown in FIG. 28. It is a top view which shows an example of the concrete vibration aspect which employ | adopted the vibration direction shown in FIG. 28 for each weight body. It is a top view which shows another example of the concrete vibration aspect which employ | adopted the vibration direction shown in FIG. 28 for each weight body. FIG. 25 is a plan view showing a state where an X ′ axis and a Y ′ axis are defined for the basic structure shown in FIG. 24. It is a top view which shows the vibration direction along the X 'axis and Y' axis shown in FIG. It is a top view which shows an example of the concrete vibration aspect which employ | adopted each vibration body as the vibration direction shown in FIG. It is a top view which shows another example of the concrete vibration aspect which employ | adopted the vibration direction shown in FIG. 33 to each weight body. FIG. 10 is a plan view (FIG. (A)) showing the structure of the basic structure of the inertial sensor according to a modification of the inertial sensor shown in FIG. 9 and a side sectional view (FIG. (B)) of cutting this along the yz plane. The hatching in (a) is given to clearly show the shape of the basic structure, not the cross section). With respect to the basic structure of the inertial sensor shown in FIG. 9 (FIG. (A)) and the basic structure of the inertial sensor shown in FIG. 36 (FIG. (B)), the weight 150 is displaced in the positive x-axis direction Δx (+). It is a stress distribution figure which shows the magnitude | size of the stress which arises in each plate-shaped bridge part when producing | generating. With respect to the basic structure of the inertial sensor shown in FIG. 9 (FIG. (A)) and the basic structure of the inertial sensor shown in FIG. 36 (FIG. (B)), the weight 150 is displaced in the Y-axis positive direction Δy (+). It is a stress distribution figure which shows the magnitude | size of the stress which arises in each plate-shaped bridge part when producing | generating. For the basic structure of the inertial sensor shown in FIG. 9 (FIG. (A)) and the basic structure of the inertial sensor shown in FIG. 18 (FIG. (B)), the weight 150 is displaced in the positive Z-axis direction Δz (+). It is a stress distribution figure which shows the magnitude | size of the stress which arises in each plate-shaped bridge part when producing | generating. FIG. 37 is a plan view showing a basic structure of an angular velocity detection device configured by providing four sets of inertial sensors having the basic structure shown in FIG. 36 (hatching in the drawing clearly shows the shape of the basic structure); (This is not a cross section.) FIG. 37 is a plan view (FIG. (A)) showing the structure of the basic structure of the inertial sensor according to a modification of the inertial sensor shown in FIG. 36, and a side sectional view (FIG. (B)) taken along the yz plane. The hatching in (a) is given to clearly show the shape of the basic structure, not the cross section). FIG. 42 is a plan view (FIG. (A)) showing the structure of the basic structure of the inertial sensor according to a further modification of the inertial sensor shown in FIG. 41 and a side sectional view (FIG. (B)) of cutting this along the yz plane. (The hatching in FIG. 1 (a) is given to clearly show the shape of the basic structure, and does not show a cross section). It is a top view which shows the basic structure used for the composite detection apparatus of angular velocity, acceleration, and pressure which concerns on this invention (The hatching in a figure is attached in order to show the shape of a basic structure clearly, and a cross section is shown. Not shown). FIG. 44 is a plan view for explaining the operation of the combined angular velocity / acceleration / pressure detection apparatus configured using the basic structure shown in FIG. 43 and a block diagram showing each circuit. It is the sectional side view which cut | disconnected the sealing structure 190 shown in FIG. 44 in the cross section along the cutting line 45-45. It is a circuit diagram which shows the bridge circuit which comprises the pressure detection circuit 530F of FIG.

  Hereinafter, the present invention will be described based on the illustrated embodiments.

<<< §1. Problems with conventional diaphragm type inertial sensors >>
First, the basic structure and problems of a diaphragm type inertial sensor that has been generally used in the past will be briefly described. FIG. 1 (a) is a plan view of an acceleration sensor employing a diaphragm structure disclosed in the above-mentioned Patent Document 1 and Patent Document 2, and FIG. 1 (b) is a side cut by a yz plane. It is sectional drawing. The hatching shown in FIG. 1 (a) is given to clearly show the arrangement of the piezoresistive elements, and does not show a cross section.

  As shown in FIG. 1 (a), the basic structure 10 constituting the acceleration sensor has a square planar shape, a surrounding pedestal portion 11, an inner diaphragm portion 12, and an inner weight body. 13. As shown in the figure, the cylindrical weight body 13 is arranged at the center position, and the periphery thereof is supported by a washer-like diaphragm portion 12, and the periphery of the diaphragm portion 12 is supported by the pedestal portion 11. As shown in b), the bottom surface of the base 11 is fixed to the top surface of the bottom plate 30 of the apparatus housing. Eventually, the weight body 13 is housed in the apparatus housing in a state where it is suspended from the center of the diaphragm portion 12.

  The entire basic structure 10 is constituted by, for example, a silicon substrate, but the diaphragm portion 12 is flexible because it is thin, and can be bent by the action of an external force. When acceleration is applied to the device casing, the pedestal portion 11 moves together with the bottom plate 30 of the device casing. However, since the weight body 13 tends to stay due to inertia, the diaphragm portion 12 bends, and the weight body 13 A displacement occurs relative to the apparatus housing.

  Such displacement of the weight body 13 can be detected as the deflection of the diaphragm portion 12. The twelve sets of piezoresistive elements 20 formed on the upper surface of the diaphragm portion 12 serve to electrically detect the deflection of the diaphragm portion 12. That is, when each part of the diaphragm 12 is bent, stress distortion resulting from the bending occurs in each piezoresistive element 20 and a change occurs in electric resistance. If this change in electrical resistance is detected by, for example, a bridge circuit, the degree of deflection of each part of the diaphragm part 12 can be extracted as an electrical signal. Since the degree of bending of each part of the diaphragm portion 12 differs depending on the direction of the applied acceleration, in the case of the illustrated example, each coordinate axis direction of the applied acceleration is based on the change in the electrical resistance of each of the 12 sets of piezoresistive elements 20. It becomes possible to detect the component.

  In the illustrated example, an xyz three-dimensional coordinate system having an origin O at the center position of the weight body 13 is defined. Four sets of piezoresistive elements 20 are arranged along the y-axis, and eight sets of piezoresistors are provided. The elements 20 are arranged in two rows along the x axis. The four sets of piezoresistive elements 20 arranged along the y-axis are used for detecting the y-axis direction component αy of the applied acceleration, and the four sets of piezoresistive elements in the first row arranged along the x-axis 20 is used to detect the x-axis direction component αx of the applied acceleration, and the four sets of piezoresistive elements 20 in the second row are used to detect the z-axis direction component αz of the applied acceleration.

  Thus, this acceleration sensor functions as a three-dimensional acceleration sensor having a function of independently detecting each coordinate axis direction component αx, αy, αz of the applied acceleration in the xyz three-dimensional coordinate system. In the example shown in the figure, the displacement of the weight body 13 (deflection of the diaphragm portion 12) is detected by the piezoresistive element 20, but in addition, a type using a strain gauge or a piezoelectric element is used as the detection element. A type, a type using a capacitive element, and the like are known and have been put into practical use. Further, instead of the washer-shaped diaphragm portion 12, a structure in which the weight body 13 is supported by, for example, a cross-shaped beam portion along the x-axis and the y-axis has been proposed.

  In this way, the weight body 13 is supported at the center position by the flexible diaphragm portion 12 (or beam portion), and the periphery of the diaphragm portion 12 (or beam portion) is fixed by the pedestal portion 11. Then, since the structure is simple, an effect of reducing the manufacturing cost can be obtained, and moreover, by detecting the deflection of the diaphragm portion 12 (or the beam portion) arranged so as to surround the weight body 13, the weight can be reduced. Since the displacement of the weight 13 can be detected, detection with relatively high sensitivity can be performed.

  However, as shown in FIG. 1 (b), since the pedestal 11 is fixed to the device housing 30, if any stress is applied to the device housing 30 during use, the stress is applied to the diaphragm through the pedestal 11. There is a problem that it is transmitted up to 12 (or beam part) and affects the detection result.

  For example, if the material of the device housing 30 and the material of the basic structure 10 have different coefficients of thermal expansion, the difference between the expansion rate of the device housing 30 and the expansion rate of the basic structure 10 depends on the temperature environment during use. Becomes conspicuous, and stress is constantly applied to the diaphragm 12 as a disturbance. Alternatively, if the device casing 30 is fixed with an adhesive or a screw in order to mount it on some measurement object, stress may be applied to the device casing 30 during the mounting. If the stress is transmitted to the diaphragm portion 12, the detection result is adversely affected.

  As described above, when the weight body is supported by the diaphragm portion and the beam portion from the periphery, it is inevitable that the detection result is adversely affected by the transmission of the stress applied to the apparatus housing. The present invention proposes a solution for solving such a problem.

<<< §2. Basic structure of inertial sensor according to the present invention >>
The feature of the inertial sensor according to the present invention is that a unique basic structure is adopted and a unique element arrangement is adopted. Hereinafter, these points will be described in detail while showing specific structures and arrangements.

<2-1. Unique Basic Structure Characteristic of the Present Invention>
FIG. 2 (a) is a plan view of the basic structure 100 used in the inertial sensor according to the present invention, and FIG. 2 (b) is a side sectional view of the basic structure 100 cut along the yz plane. Here, first, the structure of the basic structure 100 will be described.

  As shown in FIG. 2 (a), the basic structure 100 includes a plate member 110 for a fixing portion, a first plate bridge portion 120, an intermediate connection portion 125, a second plate bridge portion 130, and a weight connection. This is a spiral structure having parts 140 and weight 150. Although not shown in FIG. 2A, in reality, the basic structure 100 is housed in the apparatus housing. FIG. 2B shows a bottom plate 200 that forms a part of the apparatus housing, and shows a state in which the lower surface of the fixing member plate member 110 is fixed to the upper surface of the bottom plate 200. .

  Here, for convenience of explaining the displacement direction of the weight body 150, the origin O is set at the center of gravity of the weight body 150 in a state where the weight body 150 is stationary, and an xyz three-dimensional coordinate system is illustrated as illustrated. Define That is, in the plan view of FIG. 2 (a), the x-axis is defined below the figure, the y-axis is defined on the right side of the figure, and the z-axis is defined vertically above the page. In the side sectional view of FIG. 2 (b), the z-axis is defined above the figure, the y-axis is defined on the right side of the figure, and the x-axis is defined vertically above the page. The side cross-sectional view of FIG. 2B corresponds to a view of the basic structure 100 shown in the plan view of FIG.

  In order to distinguish from the XYZ three-dimensional coordinate system (global coordinate system) used in the angular velocity detection apparatus described in §6, in the description of the inertial sensor described here, an xyz three-dimensional coordinate system (local coordinates) using lowercase xyz. System).

  In the basic structure 100 shown in FIG. 2, the fixing portion plate member 110 is a component that fixes the root end portion (left end in the figure) of the first plate-like bridge portion 120 to the bottom plate 200 of the apparatus housing. . On the other hand, the root end portion of the second plate-like bridge portion 130 is connected to the distal end portion (right end in the drawing) of the first plate-like bridge portion 120 via the intermediate connection portion 125, so that the second plate-like shape is provided. A weight body 150 is connected to the distal end portion of the bridge portion 130 via a weight connection portion 140. The weight body 150 is a rectangular structure having a mass necessary for causing significant displacement based on the applied acceleration and angular velocity, and the components 110, 120, 125, and 130 arranged in a spiral shape. , 140 is supported.

  Although the first plate-like bridge portion 120 and the intermediate connection portion 125 do not appear in the side sectional view of FIG. 2B, the first plate-like bridge portion 120, the intermediate connection portion 125, the second plate-like shape The bridge part 130, the weight connection part 140, and the weight body 150 all have the same thickness (dimension in the z-axis direction). On the other hand, the plate member 110 for fixing part has an excessive thickness part below. For this reason, as shown in FIG. 2 (b), the first plate-like bridge portion 120, the intermediate connection portion 125, the second plate portion 110, the second connection portion 125, and the second connection portion 125 are fixed in the state where the lower surface of the fixing portion plate member 110 is fixed to the upper surface of the bottom plate 200. The plate-like bridge portion 130, the weight connection portion 140, and the weight body 150 are all lifted from the upper surface of the bottom plate 200, and the weight body 150 is held in a suspended state.

  Here, at least the first plate-like bridge portion 120 and the second plate-like bridge portion 130 have flexibility, and therefore bend due to the action of external force. For this reason, when the apparatus casing moves due to acceleration or angular velocity acting from the outside, the weight body 150 is displaced inside the apparatus casing due to the action of inertial force. For example, when acceleration in the positive direction of the y-axis acts on the apparatus housing, the bottom plate 200 moves in the right direction in the figure, so that the inertia force acting in the left direction in the figure acts on the weight body 150 and the weight The body 150 is displaced in the left direction in the figure relative to the apparatus housing. In the present application, for convenience of explanation, the inertial force acting on the weight body 150 is regarded as the acceleration or angular velocity to be detected. For example, in the case of the above example, acceleration in the positive y-axis direction + αy acts on the device casing. However, the output of the inertial sensor detects the negative acceleration in the negative y-axis direction -αy. A value is obtained.

  The basic structure 100 shown in FIG. 2 includes a first plate-like bridge portion 120 and a second plate-like bridge portion 130 each having flexibility so that the first plate-like bridge portion 120 and the second plate-like bridge portion 130 are arranged in an L shape. The distal end portion of the bridge member 120 and the root end portion of the second plate bridge portion 130 are connected via an intermediate connection portion 125, and a weight body 150 is provided on the side of the second plate bridge portion 130. As shown in the figure, the distal end portion of the second plate-like bridge portion 130 and the corner portion of the weight body 150 are connected via the weight connection portion 140. In addition, since the root end portion of the first plate-like bridge portion 120 is fixed to the upper surface of the bottom plate 200 of the apparatus housing by the fixing portion plate-like member 110 functioning as a fixing portion, the first plate-like bridge portion. The portion 120, the second plate-like bridge portion 130, and the weight body 150 are suspended in a suspended state above the bottom plate 200 of the apparatus housing in a state where no external force is applied.

  In particular, in the basic structure 100 shown in FIG. 2, the fixing portion is constituted by a fixing portion plate member 110 extending along the fixing portion longitudinal axis L <b> 0 parallel to the x axis, and this fixing portion plate member. A root end portion of the first plate-like bridge portion 120 is fixed to one end of the 110. Moreover, the first plate-like bridge portion 120 is disposed so as to extend in the y-axis direction with the first longitudinal axis Ly parallel to the y-axis as the central axis, and the second plate-like bridge portion 130 Are arranged so as to extend in the x-axis direction with a second longitudinal axis Lx parallel to the central axis as a central axis. For this reason, the structure constituted by the plate member 110 for the fixing portion, the first plate-like bridge portion 120, and the second plate-like bridge portion 130 has a “U” -shaped projection image on the xy plane. A U-shaped structure is formed, and a plate-like weight body 150 is arranged in an inner region surrounded by the U-shaped structure.

  Such a basic structure 100 has a structure suitable for mass production. That is, as can be seen from the plan view of FIG. 2 (a), the basic structure 100 is formed by forming a “U” -shaped void V in a rectangular plate member by etching or the like. It can be mass-produced by a process of creating a spiral structure as a whole.

  For example, in the embodiment shown here, a silicon substrate having a side of 5 mm square is prepared, and a groove having a width of about 0.3 mm is formed by etching, thereby forming a “U” -shaped void V, A "U" -shaped structure having a width of about 0.5 mm is used to fix the plate member 110 for the fixing portion, the first plate-like bridge portion 120, the intermediate connection portion 125, and the second plate-like bridge portion 130. The weight connection part 140 is formed. Regarding the thickness of each part, the thickness of the first plate-like bridge portion 120, the intermediate connection portion 125, the second plate-like bridge portion 130, the weight connection portion 140, and the weight body 150 is set to 0.5 mm. The thickness of the fixed portion plate member 110 was 1 mm.

  Of course, the dimension of each part can be set arbitrarily. In short, if the first plate-like bridge portion 120 and the second plate-like bridge portion 130 are set to dimensions having flexibility such that the weight body 150 can vibrate in the direction of each coordinate axis with a certain amplitude. The weight body 150 may be set to a size having a mass sufficient to detect acceleration and angular velocity, and the fixed member plate member 110 may be configured such that the entire basic structure 100 is the bottom plate of the apparatus housing. What is necessary is just to set to the dimension which can adhere to 200 firmly.

  The structure of the basic structure 100 used in the inertial sensor according to the present invention has been described above with reference to FIG. 2. In short, the basic structure 100 has a first longitudinal axis Ly that is parallel to the y axis. And a flexible first plate-like bridge portion 120 that extends in the y-axis direction and is connected directly or indirectly to the first plate-like bridge portion 120 and is parallel to the x-axis. A second plate-shaped bridge portion 130 that extends in the x-axis direction with the longitudinal axis Lx as a central axis and has flexibility, and a weight body connected directly or indirectly to the second plate-shaped bridge portion 150.

  In the example shown in FIG. 2, the tip of the first plate-like bridge portion 120 and the root end portion of the second plate-like bridge portion 130 are indirectly connected via the intermediate connection portion 125, and the second plate This is an example in which the tip of the bridge member 130 and the weight body 150 are indirectly connected via the weight connection portion 140, and the first plate-like bridge portion 120 and the second plate-like bridge portion 130 An L-shaped structure is formed. Each of these components is housed in the apparatus casing, and the root end portion of the first plate-like bridge 120 is fixed to the apparatus casing by the fixing portion plate member 110 that functions as a fixing section. Fixed to. For this reason, when an external force is applied to the apparatus housing, the weight 150 is displaced in the apparatus housing due to the bending of the first plate-like bridge portion 120 and the second plate-like bridge portion 130.

  When such a structure is compared with the structure of the basic structure 10 used in the conventional inertial sensor shown in FIG. 1, the difference between the two becomes clear. That is, the basic structure 10 shown in FIG. 1 employs a structure in which the weight body 13 is supported from the periphery by the diaphragm portion 12 having flexibility, whereas the basic structure 100 shown in FIG. In this case, a structure is used in which the weight body 150 is supported by an L-shaped structure having a first plate-like bridge portion 120 and a second plate-like bridge portion 130 having flexibility.

  This L-shaped structure is fixed to the bottom plate 200 of the apparatus housing only at its root end (the root end of the first plate-like bridge 120), and almost entirely lifts from the top surface of the bottom plate 200. It is in the state. For this reason, even when stress is applied to the bottom plate 200 of the apparatus housing for some reason when using the inertial sensor, the stress is hardly transmitted to the L-shaped structure and the detection result is hardly adversely affected. That is, if the basic structure 100 that supports the weight body 150 by the L-shaped structure having flexibility is employed, it is possible to prevent the detection result from being adversely affected by the use environment.

<2-2. Unique Device Arrangement Characterizing the Present Invention>
However, the structure itself that supports the weight body by the L-shaped structure body having flexibility as described above is a known technique as disclosed in, for example, the above-mentioned Patent Document 3. However, any of the inertial sensors employing the L-shaped structure disclosed in the prior art has a lower detection sensitivity than the inertial sensor employing the diaphragm structure (or beam structure) shown in FIG. Have a problem.

  For example, in the inertial sensor employing the diaphragm structure shown in FIG. 1, focusing on the bending of each part of the diaphragm 12 that supports the weight body 13 from the periphery, the force acting in the specific coordinate axis direction is detected most efficiently. The piezoresistive element 20 can be arranged at each possible position. The arrangement of the twelve pairs of piezoresistive elements 20 shown in FIG. 1A is an arrangement capable of performing such efficient detection, and is an arrangement that is distributed two-dimensionally on the upper surface of the diaphragm section 12. Has been adopted.

  On the other hand, in the inertial sensor employing the L-shaped structure shown in FIG. 2, such a two-dimensionally distributed element arrangement cannot be performed, and a predetermined location along the L-shaped structure is not provided. An element must be arranged.

  FIG. 3 is a plan view showing a state in which the basic structure 100 shown in FIG. 2 is fixed to the apparatus housing. A hatched area in the figure indicates an occupied area of the fixing member plate member 110, and the hatched area is fixed to the upper surface of the bottom plate 200 of the apparatus housing with an adhesive or the like. The white area | region which is not hatched is the state which floated above the baseplate 200, and is an area | region which produces a displacement by the effect | action of an external force.

  Here, the weight body 150 constitutes a plate-shaped lump, and hardly bends even if an external force acts. Therefore, the place where the element is arranged is limited to any one of the first plate-like bridge portion 120, the intermediate connection portion 125, the second plate-like bridge portion 130, and the weight connection portion 140. In addition, the bending that occurs in each of these parts is not as flexible as the bending that occurs in each part of the diaphragm, and the amount of displacement is also small. Under such circumstances, it cannot be denied that the inertial sensor employing the L-shaped structure has a lower detection sensitivity than the inertial sensor employing the diaphragm structure.

  In view of such circumstances, the inventor of the present application determines which of the basic structure 100 having the L-shaped structure when force in the x-axis, y-axis, and z-axis directions is applied to the weight body 150. An experiment for analyzing whether such a stress distribution occurs was performed by a simulation on structural mechanics using a computer (detailed experimental results are shown in stress distribution diagrams of FIGS. 37 to 39 in §7-3 later). Will be described in detail with reference to FIG. Then, by examining this experimental result, when an inherent element arrangement as shown in FIG. 4 is performed, effective detection is possible even in an inertial sensor employing an L-shaped structure, which is practically sufficient. It was confirmed that a good detection sensitivity was obtained. Hereinafter, this unique element arrangement will be described.

  The inertial sensor according to the present invention includes an acceleration sensor and an angular velocity sensor. Here, in the case of an acceleration sensor, an element disposed at a predetermined position of the basic structure 100 is a detection element that can detect stress applied to the predetermined position as distortion or displacement. In this case, since it is necessary to perform detection in a state where the weight body is vibrated, not only the detection element but also a driving element that applies a stress in a predetermined direction to a predetermined location is required. Therefore, the following specific element arrangement indicates the arrangement of the detection element in the case of the acceleration sensor, and indicates the arrangement of the detection element and the drive element in the case of the angular velocity sensor. In this application, for convenience, the term “operation element” (meaning an element used for the operation of the inertial sensor) is used as a concept including both the detection element and the drive element.

  FIG. 4 is a plan view showing 12 sets of reference regions R1 to R12 defined on the basic structure 100 shown in FIG. The hatching in the figure is given to clearly show the arrangement of each reference region, and does not show a cross section. The individual reference regions R1 to R12 are regions in which operation elements are arranged, and the inertial sensor according to the basic embodiment described here has at least one operation in each of these 12 sets of reference regions R1 to R12. It is comprised by arranging the element for operation.

  The twelve sets of reference regions shown in FIG. 4 are a first reference region R1, a second reference region R2, and a third reference region R3 defined on the surface in the vicinity of the root end portion of the first plate-like bridge portion 120. , The fourth reference region R4, the fifth reference region R5, the sixth reference region R6, and the root of the second plate-like bridge portion 130 defined on the surface in the vicinity of the tip of the first plate-like bridge portion 120. The seventh reference region R7, the eighth reference region R8, the ninth reference region R9 defined on the surface in the vicinity of the end, and the tenth defined on the surface in the vicinity of the tip of the second plate-like bridge portion 130. Of the reference region R10, the eleventh reference region R11, and the twelfth reference region R12.

  Therefore, the operating element group used in the inertial sensor according to the present invention includes the first root end side element group disposed in the vicinity of the root end portion of the first plate-like bridge portion 120, and the first plate-like element group. A first tip end side element group disposed in the vicinity of the tip end portion of the bridge portion 120; a second root end side element group disposed in the vicinity of the root end portion of the second plate-like bridge portion 130; And a second tip side element group disposed in the vicinity of the tip of the two plate-like bridge portions 130.

  In order to describe the arrangement of these 12 sets of reference regions R1 to R12 in more detail, here, a projection image obtained by orthogonal projection of each reference region on the xy plane, the first longitudinal axis Ly and the second longitudinal axis Consider a positional relationship with a projection image obtained by orthogonally projecting the direction axis Lx on the xy plane.

  At this time, in consideration of the bending structure of the L-shaped structure, the inside and outside of the first plate-like bridge portion 120 and the second plate-like bridge portion 130 are defined. That is, in FIG. 4, the portion located below the first longitudinal axis Ly of the first plate-like bridge portion 120 and the right side of the second longitudinal axis Lx of the second plate-like bridge portion 130. The part located at corresponds to the part constituting the outside in the bent structure of the L-shaped structure. Similarly, in FIG. 4, the portion located above the first longitudinal axis Ly of the first plate-like bridge portion 120 and the left side of the second longitudinal axis Lx of the second plate-like bridge portion 130. The part located in the direction corresponds to the part constituting the inner side in the bent structure of the L-shaped structure. Therefore, in the case of the illustrated example, with respect to the first plate-like bridge portion 120, the lower side of the drawing is referred to as the outer side, and the upper side is referred to as the inner side. Will be called the inside.

  Then, first, the second reference region R2 and the fifth reference region R5 are respectively defined so that the orthogonal projection image on the xy plane is located on the projection image of the first longitudinal axis Ly, The eighth reference region R8 and the eleventh reference region R11 are defined so that the orthogonal projection image on the xy plane is positioned on the projection image of the second longitudinal axis Lx. Here, the four sets of reference regions R2, R5, R8, and R11 arranged on the central axis are referred to as a center arrangement region, and the other eight sets of reference regions R1, R3, R4, R6, R7, R9, R10 and R12 will be referred to as armpit arrangement regions. Each armpit arrangement area is arranged on both sides of a predetermined center arrangement area.

  That is, the first reference region R1 is defined at a position where the orthogonal projection image onto the xy plane is adjacent to the inside of the projection image of the second reference region R2, and the third reference region R3 is defined on the xy plane. The orthographic projection image is defined at a position adjacent to the outside of the projection image of the second reference region R2, and the fourth reference region R4 has an orthographic projection image on the xy plane of the fifth reference region R5. The sixth reference region R6 is defined at a position adjacent to the outside of the projection image of the fifth reference region R5. The sixth reference region R6 is defined at a position adjacent to the inside of the projection image.

  Similarly, the seventh reference region R7 is defined at a position where the orthogonal projection image onto the xy plane is adjacent to the inside of the projection image of the eighth reference region R8, and the ninth reference region R9 is directed to the xy plane. Is defined at a position adjacent to the outside of the projection image of the eighth reference region R8. The tenth reference region R10 has an orthographic projection image on the xy plane that is the eleventh reference region R11. The twelfth reference region R12 is defined at a position where the orthogonal projection image onto the xy plane is adjacent to the outside of the projection image of the eleventh reference region R11. .

  In the example shown in FIG. 4, the 12 sets of reference regions R1 to R12 are all on the upper surface (the surface shown in FIG. 4) of the first plate-like bridge portion 120 or the second plate-like bridge portion 130. In the defined example, the eight armpit arrangement regions R1, R3, R4, R6, R7, R9, R10, and R12 are not necessarily the upper surface of the plate-like bridge portion as long as the positional relationship described above is maintained. However, it may be defined on the side surface of the plate-like bridge portion, or may be defined as a continuous region bent from the upper surface to the side surface.

  Further, the reference regions R1 to R12 shown in FIG. 4 are elongated regions extending along the longitudinal axis Ly or Lx, and are arranged in these reference regions R1 to R12 as will be described later. This is because the operation element is configured by a detection element that detects a stress acting in a direction along the longitudinal axis, or a drive element that applies a stress in a direction along the longitudinal axis.

  Furthermore, the arrangement of the reference regions R1 to R12 shown in FIG. 4 maintains symmetry with respect to the longitudinal axis Ly or Lx. This is a consideration for simplifying the configuration of the detection circuit described later by providing symmetry to the arrangement pattern of the operating element groups arranged in each of the reference regions R1 to R12.

  That is, the six sets of reference regions R1 to R6 on the first plate-like bridge portion 120 have a pattern in which the orthogonal projection image on the xy plane is line symmetric with respect to the projection image of the first longitudinal axis Ly. The pattern of the orthogonal projection image on the xy plane of the operating element group arranged in the first plate-like bridge portion 120 is line-symmetric with respect to the projection image of the first longitudinal axis Ly. It is consideration to make it become.

  Similarly, in the six sets of reference regions R7 to R12 on the second plate-shaped bridge portion 130, a pattern in which an orthogonal projection image on the xy plane is axisymmetric with respect to a projection image of the second longitudinal axis Lx. This is because the pattern of the orthographic projection image on the xy plane of the operating element group arranged in the second plate-like bridge portion 130 is a line with respect to the projection image of the second longitudinal axis Lx. It is a consideration to make it symmetrical.

<2-3. Technical significance of unique element placement>
The inertial sensor according to the present invention is a sensor that detects an acceleration acting in a predetermined coordinate axis direction or an angular velocity acting around a predetermined coordinate axis in an xyz three-dimensional coordinate system. Therefore, operation element groups are arranged at predetermined positions of the first plate-like bridge portion 120 and predetermined positions of the second plate-like bridge portion 130. As will be described later, these operation element groups are used to act. A detection circuit for detecting the acceleration or angular velocity is added.

  As already described, the individual detection elements and driving elements constituting the operation element group are arranged in any one of the reference regions R1 to R12 as shown in FIG. Therefore, here, the technical significance of arranging the operating element groups in the 12 sets of reference regions R1 to R12 will be described.

  The first feature of the arrangement of the 12 sets of reference regions R1 to R12 is that each region is arranged at the root end portion or the tip end portion of the plate-like bridge portions 120 and 130. These portions are regions where stress is particularly concentrated when the weight body 150 is displaced (for details, see the description with reference to stress distribution diagrams of FIGS. 37 to 39 described later). For this reason, if an operation element group is arranged in these reference regions R1 to R12, extremely efficient detection operation and drive operation can be performed.

  The second feature of the arrangement of the 12 sets of reference regions R1 to R12 is that when an external force in a specific coordinate axis direction in the xyz three-dimensional coordinate system acts on the weight 150, each reference region This is a point where a specific stress is selectively generated. I will explain this in the case of individual cases.

  FIG. 5 is a plan view showing a stretched state of a portion in each of the reference regions R1 to R12 when the weight body 150 of the basic structure 100 shown in FIG. 4 generates a displacement Δx (+) in the x-axis positive direction. is there. Similarly, FIG. 6 is a plan view showing a stretched state when a displacement Δy (+) in the y-axis positive direction is generated, and FIG. 7 is a stretched state when a displacement Δz (+) in the z-axis positive direction is generated. FIG. Such a displacement occurs when acceleration in the positive direction of each coordinate axis acts on the weight body 150, and due to the displacement, each of the plate-like bridge portions 120, 130 bends, and the basic structure The body 100 deforms. However, in FIG. 5 to FIG. 7, for convenience of illustration, depiction of the displacement state of the basic structure 100 is omitted, and the expansion and contraction states of the reference regions R1 to R12 are indicated by arrows (the arrows with arrows at both ends extend). State, a pair of arrows facing each other indicates a contracted state).

  When the weight body 150 is displaced in the positive x-axis direction Δx (+), the reference regions R6, R9, and R12 arranged outside the L-shaped structure are all long as shown in FIG. Although stress extending in the direction (tensile stress) acts on the reference region R3, stress contracting in the longitudinal direction (compressive stress) acts on the reference region R3. On the other hand, stress that contracts in the longitudinal direction acts on the reference regions R4, R7, and R10 disposed inside the L-shaped structure, but stress that extends in the longitudinal direction acts on the reference region R1.

  Although the reference region R3 is located outside the L-shaped structure, the reference region R6 is reversely expanded and contracted with the other reference regions R6, R9, and R12. Despite being located inside the L-shaped structure, the stretched state is reversed from the reference regions R4, R7, R10 located inside the other. Thus, in order to explain the reason why expansion / conversion inversion occurs at the root end portion of the first plate-like bridge portion 120, a complicated theoretical development is required, and thus the explanation is omitted here. Has confirmed that the stretching stress shown in the figure is generated by executing a structural mechanics simulation using a computer (see FIG. 37 described later).

  For the four central arrangement regions R2, R5, R8, and R11 arranged on the longitudinal axes Lx and Ly serving as the center lines, the right half and the left half divided by the center lines are slightly reversed. Therefore, it can be considered that the stress is balanced as a whole and expansion and contraction does not occur.

  FIG. 5 shows a state when the displacement Δx (+) in the x-axis positive direction occurs. When the displacement Δx (−) in the negative x-axis direction occurs, the weight body 150 is displaced in the reverse direction. Thus, the stretched state of each part is the reverse of the state shown in FIG.

  On the other hand, when the weight body 150 is displaced in the y-axis positive direction Δy (+), as shown in FIG. 6, the reference regions R3, R6, and R9 arranged outside the L-shaped structure Although stress contracting in the longitudinal direction also acts, stress extending in the longitudinal direction acts on the reference region R12. In addition, stress that extends in the longitudinal direction acts on the reference regions R1, R4, and R7 arranged inside the L-shaped structure, but stress that contracts in the longitudinal direction acts on the reference region R10.

  Although the reference region R12 is positioned outside the L-shaped structure, the reference region R10 is reversely expanded and contracted with the other reference regions R3, R6, and R9. Despite being located inside the L-shaped structure, the stretched state is reversed from the reference regions R1, R4, R7 located inside the other. Thus, in order to explain the reason why the expansion and contraction inversion occurs at the tip of the second plate-like bridge portion 130, a complicated theoretical development is required, so the explanation is omitted here. It has been confirmed that a stretching stress as shown in the figure is generated by executing a structural mechanics simulation using a computer (see FIG. 38 described later).

  Also in this case, the four central arrangement regions R2, R5, R8, and R11 arranged on the longitudinal axes Lx and Ly serving as the center lines are slightly in the right half and the left half divided by the center line. Therefore, it can be considered that the stress is balanced as a whole and expansion and contraction does not occur.

  FIG. 6 shows a state when a displacement Δy (+) in the y-axis positive direction occurs. When a displacement Δy (−) in the y-axis negative direction occurs, the weight body 150 is displaced in the reverse direction. Therefore, the stretched state of each part is the reverse of the state shown in FIG.

  Finally, in the case where the weight body 150 has a displacement Δz (+) in the positive z-axis direction (vertical upper direction in the drawing), as shown in FIG. 7, the vicinity of the root end portion of the first plate-like bridge portion 120 In the reference regions R1, R2, R3 and the reference regions R7, R8, R9 in the vicinity of the root end portion of the second plate-like bridge portion 130, stress contracting in the longitudinal direction acts, but the first plate-like bridge portion Stress extending in the longitudinal direction acts on the reference regions R4, R5, R6 near the front end portion of 120 and the reference regions R10, R11, R12 near the front end portion of the second plate-like bridge portion 130. Although the detailed explanation about the reason why such stress acts is omitted, the present inventor confirmed that the stretching stress as shown in the figure is generated by executing a structural mechanical simulation using a computer. (See FIG. 39 described later).

  FIG. 7 shows the state when the displacement Δz (+) in the positive z-axis direction is generated. When the displacement Δz (−) in the negative z-axis direction is generated, the weight body 150 is displaced in the reverse direction. Therefore, the stretched state of each part is the reverse of the state shown in FIG.

  FIG. 8 is a table that collectively shows the stretched states shown in FIGS. 5 to 7, where the symbol + is a state in which a stress that extends in the longitudinal direction acts, the symbol − is a state in which a stress that contracts in the longitudinal direction acts, and a symbol 0. Indicates a state in which no significant stretching occurs. For example, the result of each column of “displacement Δx (+)” on the first line in the list of FIG. 8 is “+” in the reference area column of the extending part in the expansion / contraction distribution shown in FIG. "-" Is written in the area column, and "0" is written in the reference area column of the portion where expansion and contraction does not occur as a whole. Similarly, the result of each column of “displacement Δy (+)” in the second row corresponds to the expansion / contraction distribution shown in FIG. 6, and the result of “displacement Δz (+)” in the third row. The results in each column correspond to the stretch distribution shown in FIG.

  As described above, when the weight body 150 is displaced in the x-axis, y-axis, and z-axis directions, inherent stretching stress is applied to the 12 sets of reference regions R1 to R12, respectively. This is very important in independently detecting the coordinate axis components. In the present invention, the technical significance that the reference regions R1 to R12 have the unique arrangement as described above is that the weight body 150 has an x-axis, a y-axis, and a z-axis as shown in the list of FIG. When the displacement occurs in the direction, a specific stretching stress is selectively applied to each reference region.

  As described in §3 and later, when a piezoresistive element is used as the detection element, the expansion / contraction stress can be electrically detected as an increase / decrease in electrical resistance, and when a piezoelectric element is used as the detection element, the expansion / contraction stress is detected. Can be detected as a positive or negative generated charge amount. In addition, when a piezoelectric element is used as the drive element, it is possible to generate stretching stress in each part by supplying an AC drive signal.

  Therefore, in consideration of the behavior shown in the list of FIG. 8, if a detection circuit that operates by appropriately combining each operation element is provided, each coordinate axis direction component of the applied acceleration is efficiently detected, It becomes possible to efficiently detect the component around each coordinate axis of the applied angular velocity. A specific detection method will be described in detail in §3 and later.

<<< §3. Accelerometer using piezoresistive element >>
In order to configure an acceleration sensor using the basic structure 100 described in §2, the individual elements constituting the operation element group acted in the longitudinal direction of the plate-like bridge portions 120 and 130 at the respective arrangement positions. What is necessary is just to prepare the detection circuit which comprises the detection element which detects a stress electrically, and detects the acceleration which acted on the predetermined coordinate-axis direction based on the detection result of each of these detection elements. Here, an embodiment in which an acceleration sensor is configured by using a piezoresistive element as the operating element group will be described.

  FIG. 9A is a plan view showing the basic structure 100 of the embodiment according to such an acceleration sensor, and the drawing is the same as the plan view of the basic structure 100 shown in FIG. However, 12 sets of reference regions R1 to R12 shown in FIG. 4 are replaced with 12 sets of piezoresistive elements 301 to 312 in FIG. 9A. The hatching in FIG. 9A is given to clearly show the arrangement of the piezoresistive elements 301 to 312 and does not show a cross section.

  In short, the basic structure 100 of the acceleration sensor shown in FIG. 9A is obtained by embedding the piezoresistive elements 301 to 312 at the positions of the reference regions R1 to R12 in the basic structure 100 shown in FIG. become. The lower two digits 1 to 12 of the reference numerals 301 to 312 of the piezoresistive elements correspond to the reference numerals R1 to R12 of the reference regions.

  In the present application, the individual operation elements arranged in the reference regions R1 to R12 are referred to as the first attribute element to the twelfth attribute element by quoting the numerical portions of the reference regions R1 to R12. To. Here, the “attribute” indicates a property of “arranged in a specific reference area”. For example, an element arranged in the reference region R1 is a first attribute element, and an element arranged in the reference region R2 is a second attribute element.

  In the end, in the case of the inertial sensor according to the basic embodiment of the present invention, the first root end side element group arranged in the vicinity of the root end portion of the first plate-like bridge portion 120 is the first reference region. A first plate having a first attribute element disposed in R1, a second attribute element disposed in the second reference region R2, and a third attribute element disposed in the third reference region R3; The first distal end side element group disposed in the vicinity of the distal end portion of the bridge portion 120 has a fourth attribute element disposed in the fourth reference region R4 and a fifth attribute region disposed in the fifth reference region R5. It has the attribute element and the sixth attribute element arranged in the sixth reference region R6.

  Similarly, the second root end portion side element group disposed in the vicinity of the root end portion of the second plate-like bridge portion 130 includes the seventh attribute element disposed in the seventh reference region R7, The second attribute element arranged in the vicinity of the tip of the second plate-like bridge portion 130 has the eighth attribute element arranged in the reference region R8 and the ninth attribute element arranged in the ninth reference region R9. The tip portion side element group is arranged in the tenth attribute element arranged in the tenth reference region R10, the eleventh attribute element arranged in the eleventh reference region R11, and the twelfth reference region R12. It has a twelfth attribute element.

  In the specific embodiment shown in FIG. 9A, the piezoresistive elements 301 to 312 are the first attribute element to the twelfth attribute element. Such piezoresistive elements 301 to 312 can be formed, for example, by constituting the basic structure 100 with a silicon substrate and embedding predetermined impurities in the reference regions R1 to R12 on the upper surface thereof. As shown in the figure, the piezoresistive elements 301 to 306 formed on the first plate-like bridge portion 120 are elongated elements extending along the first longitudinal axis Ly, and are formed on the second plate-like bridge portion 130. The piezoresistive elements 307 to 312 are elongated elements extending along the second longitudinal axis Lx.

  FIG. 9 (b) is a side sectional view showing a state in which the basic structure 100 shown in FIG. 9 (a) is accommodated in the apparatus housing, and is cut at a position indicated by a cutting line 9b-9b in FIG. 9 (a). A cross section is shown. As shown in the figure, the lower surface of the fixing member plate member 110 is fixed to the upper surface of the bottom plate 200 of the apparatus housing. The figure shows a state in which the cover 400 of the apparatus housing having the top plate 410 and the side plate 420 is attached to the upper surface of the bottom plate 200. The cover 400 and the bottom plate 200 constitute a device casing. The first plate-like bridge portion 120, the second plate-like bridge portion 130, the weight connection portion 140, and the weight body 150 are included in the device case. It is suspended.

  In the example shown in the figure, the distance between the upper surface of the weight body 150 and the lower surface of the top plate 410 and the distance between the lower surface of the weight body 150 and the upper surface of the bottom plate 200 are secured relatively large. If the distance is set to an appropriate dimension, the top plate 410 and the bottom plate 200 can function as stopper members. That is, since the inner wall surface of the apparatus housing functions as a control member that restricts excessive displacement of the weight body 150, excessive acceleration (acceleration that damages the plate-like bridge portions 120 and 130) is applied to the weight body 150. Even when the weight is added, the excessive displacement of the weight body 150 can be restricted, and the situation where the plate-like bridge portions 120 and 130 are damaged can be avoided. However, if the gap between the top plate 410 and the weight body 150 or the gap between the bottom plate 200 and the weight body 150 is too narrow, the displacement of the weight body 150 is hindered due to the influence of air damping. Cost.

  9B shows a cross section of three sets of piezoresistive elements 310 to 312, and wiring from these piezoresistive elements to the detection circuit 500 is schematically depicted. In FIG. 9B, the detection circuit 500 is shown as a simple block, but a specific circuit diagram will be described later. When the basic structure 100 is configured by a silicon substrate, the detection circuit 500 can be formed on the silicon substrate (for example, the plate member 110 for the fixing portion).

  In practice, wiring for each piezoresistive element is performed at both end points in the longitudinal direction. Since the electrical resistance value between the both end points changes according to the stress applied in the longitudinal direction, the applied stretching stress can be detected by increasing or decreasing the electrical resistance value. In the embodiment shown here, a p-type piezoresistive element is used in which the electrical resistance increases when a stress in the extending direction acts and the electrical resistance decreases when a stress in the contracting direction acts.

  As described above, when the individual detection elements constituting the operation element group are configured by the piezoresistive elements 310 to 312 arranged along the longitudinal direction of the plate-like bridge portions 120 and 130, the detection circuit 500. As an example, a circuit that detects acceleration acting in a predetermined coordinate axis direction can be configured based on the output of a bridge circuit using the piezoresistive elements 310 to 312.

  FIG. 10 is a circuit diagram showing an example of the detection circuit 500 used in the embodiment shown in FIG. As shown in the figure, this detection circuit 500 is composed of three sets of Wheatstone bridge circuits: a bridge circuit shown in FIG. 10 (a), a bridge circuit shown in FIG. 10 (b), and a bridge circuit shown in FIG. 10 (c). ing. A predetermined reference voltage is applied from the power supply 300 to any bridge circuit.

  The bridge circuit shown in FIG. 10A is a bridge having the first attribute element 301 and the sixth attribute element 306 as the first opposite side, and the third attribute element 303 and the fourth attribute element 304 as the second opposite side. This circuit has a function of detecting acceleration αx (force fx) acting in the x-axis direction and outputting it as a bridge voltage Vx between the output terminals T11 and T12.

  Similarly, the bridge circuit shown in FIG. 10B has the seventh attribute element 307 and the twelfth attribute element 312 as the first opposite side, and the ninth attribute element 309 and the tenth attribute element 310 as the second opposite side. And has a function of detecting an acceleration αy (force fy) acting in the y-axis direction and outputting it as a bridge voltage Vy between the output terminals T13 and T14.

  Further, the bridge circuit shown in FIG. 10C has the fifth attribute element 305 and the eleventh attribute element 311 as the first opposite side, and the second attribute element 302 and the eighth attribute element 308 as the second opposite side. And has a function of detecting an acceleration αz (force fz) acting in the z-axis direction and outputting it as a bridge voltage Vz between the output terminals T15 and T16.

  The reason why each coordinate circuit direction component αx, αy, αz of the applied acceleration can be detected by each bridge circuit shown in FIG. 10 can be easily understood by referring to the list shown in FIG. That is, when the piezoresistive elements 301 to 312 are made to correspond to the reference regions R1 to R12 in the list of FIG. 8, when the corresponding column is “+” (extended stress generation), the increase in the electric resistance value is increased. When the corresponding column is “-” (shrinking stress is generated), it indicates a decrease in the electric resistance value, and when the corresponding column is “0” (no significant expansion / contraction), it indicates that there is no change in the electric resistance value. Will be.

  Therefore, first, when the acceleration + αx in the positive x-axis direction acts on the weight body 150 and the displacement Δx (+) in the positive x-axis direction occurs on the weight body 150 as shown in FIG. Think about it. In this case, resistance values as shown in each column of Δx (+) in the list of FIG. 8 are generated in the piezoresistive elements 301 to 312 constituting each bridge circuit shown in FIG.

  That is, in the bridge circuit shown in FIG. 10A, the resistance values of the elements 301 and 306 increase (R1 and R6 in the corresponding column Δx (+) in FIG. 8 are both “+”), and the elements 303 and 304 (The R3 and R4 in the corresponding column Δx (+) in FIG. 8 are both “−”), the bridge equilibrium state is lost, and the displacement Δx (+) is between the output terminals T11 and T12. A positive bridge voltage Vx corresponding to the magnitude of is output. On the other hand, when the acceleration −αx in the negative x-axis direction is applied, a displacement Δx (−) in the reverse direction occurs, so that the sign of each of the above columns is reversed, and between the output terminals T11 and T12, A negative bridge voltage Vx corresponding to the magnitude of the displacement Δx (−) is output.

  Thus, the x-axis detection voltage Vx output from the bridge circuit shown in FIG. 10 (a) depends on the direction of the x-axis direction component αx of the acceleration acting on the weight 150 (whether the x-axis is positive or negative). It shows the size. Moreover, when only the x-axis direction component αx of the acceleration is acting, no significant detection voltage is output from the bridge circuit shown in FIG. 10B or the bridge circuit shown in FIG.

  For example, in the bridge circuit shown in FIG. 10B, the resistance value of the element 312 decreases while the resistance value of the element 312 increases (R7 in the corresponding column Δx (+) in FIG. 8 is “−”, but R12 Becomes “+”). Further, although the resistance value of the element 309 increases, the resistance value of the element 310 decreases (R9 in the corresponding column Δx (+) in FIG. 8 is “+”, but R10 is “−”). Therefore, the balanced state of the bridge is maintained, and the y-axis detection voltage Vy output from the bridge circuit becomes zero.

  On the other hand, in the bridge circuit shown in FIG. 10 (c), there is no significant change in the resistance values of the elements 305, 311, 302, and 308 (R5, R11, R2, and R8 in the corresponding column Δx (+) in FIG. Both are “0”). Therefore, the balanced state of the bridge is maintained, and the z-axis detection voltage Vz output from the bridge circuit becomes zero.

  Subsequently, when the acceleration + αy in the y-axis positive direction acts on the weight body 150 and the displacement Δy (+) in the y-axis positive direction occurs with respect to the weight body 150 as shown in FIG. I'll think about it. In this case, a change in resistance value as shown in each column of Δy (+) in the list of FIG. 8 occurs in the piezoresistive elements 301 to 312 constituting each bridge circuit shown in FIG.

  Here, first consider the bridge circuit shown in FIG. In this bridge circuit, the resistance values of the elements 307 and 312 increase (R7 and R12 in the corresponding column Δy (+) in FIG. 8 are both “+”), and the resistance values of the elements 309 and 310 decrease (in FIG. 8). Since R9 and R10 in the corresponding column Δy (+) are both “−”), the balanced state of the bridge is lost, and a positive bridge corresponding to the magnitude of the displacement Δy (+) is present between the output terminals T13 and T14. A voltage Vx is output. On the other hand, when the acceleration -αy in the negative y-axis direction is applied, a displacement Δy (−) in the reverse direction occurs, so the sign of each of the above columns is reversed, and between the output terminals T13 and T14, A negative bridge voltage Vy corresponding to the magnitude of the displacement Δy (−) is output.

  Thus, the y-axis detection voltage Vy output from the bridge circuit shown in FIG. 10 (b) indicates the direction and magnitude of the y-axis direction component αy of the acceleration acting on the weight body 150. Moreover, when only the y-axis direction component αy of the acceleration is acting, no significant detection voltage is output from the bridge circuit shown in FIG. 10 (a) or the bridge circuit shown in FIG. 10 (c).

  For example, in the bridge circuit shown in FIG. 10A, the resistance value of the element 301 increases while the resistance value of the element 306 decreases (R1 in the corresponding column Δy (+) in FIG. 8 is “+”, but R6 Becomes "-"). Further, although the resistance value of the element 303 decreases, the resistance value of the element 304 increases (R3 in the corresponding column Δy (+) in FIG. 8 is “−”, but R4 is “+”). Therefore, the balanced state of the bridge is maintained, and the y-axis detection voltage Vy output from the bridge circuit becomes zero.

  On the other hand, in the bridge circuit shown in FIG. 10 (c), there is no significant change in the resistance values of the elements 305, 311, 302, and 308 (R5, R11, R2, and R8 in the corresponding column Δy (+) in FIG. Both are “0”). Therefore, the balanced state of the bridge is maintained, and the z-axis detection voltage Vz output from the bridge circuit becomes zero.

  Finally, the case where the acceleration + αz in the z-axis positive direction acts on the weight body 150 and the displacement Δz (+) in the z-axis positive direction occurs on the weight body 150 as shown in FIG. I'll think about it. In this case, a resistance value change as shown in each column of Δz (+) in the list of FIG. 8 occurs in the piezoresistive elements 301 to 312 constituting each bridge circuit shown in FIG.

  First, consider the bridge circuit shown in FIG. In this bridge circuit, the resistance values of the elements 305 and 311 increase (R5 and R11 in the corresponding column Δz (+) in FIG. 8 are both “+”), and the resistance values of the elements 302 and 308 decrease (in FIG. 8). Since R2 and R8 in the corresponding column Δz (+) are both “−”), the bridge equilibrium state is lost, and a positive bridge corresponding to the magnitude of the displacement Δz (+) is present between the output terminals T15 and T16. A voltage Vz is output. Conversely, when an acceleration −αz in the negative z-axis direction is applied, a displacement Δz (−) in the reverse direction occurs, so that the sign of each of the above columns is reversed, and between the output terminals T15 and T16, A negative bridge voltage Vz corresponding to the magnitude of the displacement Δz (−) is output.

  Thus, the z-axis detection voltage Vz output from the bridge circuit shown in FIG. 10C indicates the direction and magnitude of the z-axis direction component αz of the acceleration acting on the weight body 150. In addition, when only the z-axis direction component αz of the acceleration is acting, no significant detection voltage is output from the bridge circuit shown in FIG. 10 (a) or the bridge circuit shown in FIG. 10 (b).

  For example, in the bridge circuit shown in FIG. 10A, the resistance value of the element 301 decreases while the resistance value of the element 306 increases (R1 in the corresponding column Δz (+) in FIG. 8 is “−”, but R6 Becomes “+”). Further, although the resistance value of the element 303 decreases, the resistance value of the element 304 increases (R3 in the corresponding column Δz (+) in FIG. 8 is “−”, but R4 is “+”). Accordingly, the balanced state of the bridge is maintained, and the x-axis detection voltage Vx output from the bridge circuit becomes zero.

  On the other hand, in the bridge circuit shown in FIG. 10B, the resistance value of the element 312 decreases while the resistance value of the element 312 increases (R7 in the corresponding column Δz (+) in FIG. 8 is “−”, but R12 Becomes “+”). Further, although the resistance value of the element 309 decreases, the resistance value of the element 310 increases (R9 in the corresponding column Δz (+) in FIG. 8 is “−”, but R10 is “+”). Therefore, the balanced state of the bridge is maintained, and the y-axis detection voltage Vy output from the bridge circuit becomes zero.

  Finally, considering the operation of the detection circuit 500 shown in FIG. 10 with reference to the list of FIG. 8, the x-axis detection voltage Vx output from the bridge circuit of FIG. 10 (a) does not include other axis components. Only the x-axis direction component αx of the acceleration is shown, and the y-axis detection voltage Vy output from the bridge circuit of FIG. 10B shows only the y-axis direction component αy of the acceleration not including the other-axis component. Thus, it can be understood that the z-axis detection voltage Vz output from the bridge circuit of FIG. 10 (c) shows only the z-axis direction component αz of the acceleration not including the other-axis component. As described above, according to the inertial sensor according to the embodiment shown here, each coordinate axis direction component αx, αy, αz of acceleration is detected independently and with high detection sensitivity without receiving interference from other axis components. It becomes possible to do.

  In the above-described operation, the orthographic projection image on the xy plane of the operation element group (piezoresistive elements 301 to 306) arranged in the first plate-like bridge 120 is the first longitudinal axis Ly. An orthographic projection image on the xy plane of the operating element group (piezoresistive elements 307 to 312) having a pattern that is line-symmetric with respect to the projection image and arranged on the second plate-like bridge portion 130 is the second projection image. It is premised on having a line-symmetric pattern with respect to the projection image of the longitudinal axis Lx.

  By providing such a symmetry in the arrangement pattern of each element, the effect of canceling out the increase and decrease in resistance value for a specific element pair can be obtained, and as described above, detection operation that eliminates interference from other axis components Is possible. Of course, if the length, width, resistance value (impurity concentration), etc. in the longitudinal direction are adjusted as appropriate for the specific element pair, the effect of offsetting the increase or decrease in resistance value can be obtained even if the symmetry is not necessarily maintained. Since it can be obtained, the symmetry of the element arrangement pattern is not an essential requirement for implementing the present invention. However, in practice, it is preferable to obtain an element arrangement pattern having the above symmetry.

  Further, the detection circuit 500 of the inertial sensor shown in FIG. 9 is not necessarily limited to the circuit shown in FIG. 10, and based on the results shown in the list of FIG. Any other circuit may be adopted as long as the circuit can be used.

  For example, FIG. 11 is a circuit diagram showing another example of the detection circuit 500 used in the embodiment shown in FIG. This detection circuit is composed of three sets of Wheatstone bridge circuits: a bridge circuit shown in FIG. 11 (a), a bridge circuit shown in FIG. 11 (b), and a bridge circuit shown in FIG. 11 (c). A predetermined reference voltage is applied from the power supply 300 to any bridge circuit.

  The bridge circuit shown in FIG. 11A is a bridge having the ninth attribute element 309A and the twelfth attribute element 312A as the first opposite side, and the seventh attribute element 307A and the tenth attribute element 310A as the second opposite side. This circuit has a function of detecting acceleration αx (force fx) acting in the x-axis direction and outputting it as a bridge voltage Vx between the output terminals T21 and T22.

  Similarly, the bridge circuit shown in FIG. 11 (b) has the first attribute element 301A and the fourth attribute element 304A as the first opposite side, and the third attribute element 303A and the sixth attribute element 306A as the second opposite side. And has a function of detecting an acceleration αy (force fy) acting in the y-axis direction and outputting it as a bridge voltage Vy between the output terminals T23 and T24.

  Further, the bridge circuit shown in FIG. 11 (c) includes a side formed by connecting the fourth attribute element 304B, the fifth attribute element 305, and the sixth attribute element 306B in series, the tenth attribute element 310B, the eleventh attribute element 311, and the like. One side formed by connecting the twelfth attribute element 312B in series is defined as the first opposite side, and the one side formed by connecting the first attribute element 301B, the second attribute element 302, and the third attribute element 303B in series and the seventh attribute element 307B. , The eighth attribute element 308 and the ninth attribute element 309B are bridge circuits having a second side opposite to one side formed by connecting them in series, and detecting and outputting an acceleration αz (force fz) acting in the z-axis direction. It has a function of outputting as a bridge voltage Vz between the terminals T25 and T26.

  Although detailed explanation is omitted here, the reason why each coordinate circuit direction component αx, αy, αz of the applied acceleration can be detected independently without receiving interference from other axes by each bridge circuit shown in FIG. However, it can be easily understood by referring to the list shown in FIG.

  Note that symbols A or B are attached to the end of the reference numerals of some of the piezoresistive elements constituting the bridge circuit shown in FIG. When used, it is for distinguishing the two. For example, the ninth attribute element 309A is used in the bridge circuit shown in FIG. 11 (a), and the ninth attribute element 309B is used in the bridge circuit shown in FIG. 11 (c). Each element is a ninth attribute element arranged in the reference region R9, but is an electrically independent separate piezoresistive element.

  As described above, in carrying out the present invention, it is not always necessary to arrange only one operation element in one reference region. If a plurality of identical attribute elements are necessary for detection operation, the same operation element is not necessarily used. A plurality of different operating elements may be arranged in the reference region.

  FIG. 12 is a plan view showing an example in which two sets of piezoresistive elements are arranged in the same reference region. Again, the hatching in the figure is given to clearly show the arrangement of each piezoresistive element and does not show a cross section. The illustrated example is an example in which two sets of piezoresistive elements are arranged in each of the reference regions R10, R11, and R12 shown in FIG. That is, piezoresistive elements 310A and 310B are arranged in the reference region R10, piezoresistive elements 311A and 311B are arranged in the reference region R11, and piezoresistive elements 312A and 312B are arranged in the reference region R12. Is arranged.

  A pair of piezoresistive elements arranged in parallel in the same reference region are formed at a predetermined interval from each other and are electrically independent. Therefore, the detection circuit 500 can be incorporated as components of different bridge circuits. Of course, if necessary, three or more sets of operating elements may be arranged in the same reference region.

  FIG. 13 is a plan view showing an arrangement example of piezoresistive elements when the detection circuit shown in FIG. 11 is used in the embodiment of the inertial sensor (acceleration sensor) shown in FIG. Again, the hatching in the figure is given to clearly show the arrangement of each piezoresistive element and does not show a cross section. In the figure, four sets of piezoresistive elements 302, 305, 308, and 311 shown by hatching are elements arranged in one set in the reference regions R2, R5, R8, and R11, respectively. On the other hand, 16 sets of piezoresistive elements 301A, 301B,..., 312A, 312B indicated by thick black lines in the figure are reference regions R1, R3, R4, R6, R7, R9, R10, R12, respectively. It is an element arranged in pairs in the inside.

  A total of 20 sets of piezoresistive elements incorporated in the three bridge circuits shown in FIG. 11 correspond to the 20 sets of piezoresistive elements shown in FIG. In this example as well, in practice, the arrangement pattern of each element is provided with symmetry so that the effect of canceling out the increase and decrease in resistance value for a specific pair of elements can be obtained in one bridge circuit. Is preferred.

  In FIG. 13, the positional relationship between the piezoresistive element with A at the end of the symbol and the piezoresistive element with B at the end of the symbol has symmetry with respect to the longitudinal axes Lx and Ly. This is because such a point is taken into consideration. That is, in the case of the illustrated example, an element (for example, 310A, 312A) with an A at the end of the code is arranged at a position far from the longitudinal axis, and an element with an B at the end of the code (for example, 310B, 312B). ) Is arranged at a position close to the longitudinal axis so that elements having the same symbol at the end of the code are arranged in a symmetrical position (for example, 310A and 312A are arranged in a symmetrical position, 310B and 312B are arranged at symmetrical positions.)

<<< §4. Acceleration sensor using piezoelectric element >>>
Next, an embodiment in which an acceleration sensor is configured by using a piezoelectric element using a layered piezoelectric body 600 as an operation element group while using the basic structure 100 shown in FIG. 4 will be described. FIG. 14A is a plan view showing such an acceleration sensor (not shown for the device casing), and FIG. 14B is a side sectional view of the device taken along the yz plane (device). The housing is also shown).

  As shown in FIG. 14 (b), a layered lower layer electrode 650 is formed on the entire upper surface of the basic structure 100 (shown in FIG. 4), and a layered piezoelectric body 600 is formed on the entire upper surface thereof. Is formed. On the upper surface of the piezoelectric body 600, an upper layer electrode group including a plurality of locally formed upper layer electrodes is formed. Note that FIG. 14B shows a side cross-section cut at the position indicated by the cutting line 14b-14b in FIG. 14A, so that only the three upper layer electrodes 610, 611, and 612 appear in the figure. ing.

  The lower layer electrode and the upper layer electrode may be formed using a general conductive material such as metal. In the case of the example shown here, the lower layer electrode 650 and the upper layer electrode group are formed of a thin metal layer (a metal layer comprising two layers of a titanium film and a platinum film) having a thickness of about 300 nm. Further, as the layered piezoelectric body 600, a thin film having a thickness of about 2 μm made of PZT (lead zirconate titanate), KNN (potassium sodium niobate) or the like is used. Of course, it is not always necessary to use a thin film as the piezoelectric body 600.

  As shown in FIG. 14 (b), also in the embodiment shown here, the apparatus housing is constituted by the bottom plate 200 and the cover 400, and the basic structure 100 is accommodated in the apparatus enclosure. . Similarly to the embodiment described in §3, the basic structure 100 is fixed to the upper surface of the bottom plate 200 by the fixing plate member 110, and the weight body 150 is suspended in the apparatus housing. ing. The cover 400 is constituted by the top plate 410 and the side plate 420, and the weight body 150 is displaced in the internal space of the cover 400. Also in this embodiment, if the distance between the upper surface of the weight body 150 and the lower surface of the top plate 410 and the distance between the lower surface of the weight body 150 and the upper surface of the bottom plate 200 are set to appropriate dimensions, the top plate 410 and the bottom plate 200 can function as stopper members.

  In the case of this inertial sensor, as shown in FIG. 14 (a), the upper electrode group consists of twelve upper layer electrodes 601 to 612 (hatching in the figure is given in order to clearly show the electrode formation region, Is not shown). Here, the arrangement positions of the upper layer electrodes 601 to 612 respectively correspond to the arrangement of the reference regions R1 to R12 shown in FIG.

  As described above, the layered lower layer electrode 650 is formed on the entire upper surface of the basic structure 100, and the layered piezoelectric body 600 is formed on the entire upper surface of the basic structure 100. Therefore, as shown in FIG. The twelve upper layer electrodes 601 to 612 are all formed on the upper surface of the layered piezoelectric body 600. FIG. 14 (a) is a plan view of the inertial sensor as viewed from above, so that the piezoelectric body 600 covering the entire surface of the basic structure 100 can be seen. For convenience, FIG. 14 (a) The positions of the fixed plate member 110, the first plate bridge portion 120, the second plate bridge portion 130, the weight connection portion 140, and the weight body 150 are indicated by parenthesized symbols.

  Here, since the layered piezoelectric body 600 is disposed below the 12 upper layer electrodes 601 to 612 and the lower layer electrode 650 is disposed below the 12 layers of the upper layer electrodes 601 to 612, each reference region R1 to R12 is individually provided. This piezoelectric element is formed. For example, in the reference region R1, the upper layer electrode 601, a part of the layered piezoelectric body 600 positioned immediately below the upper layer electrode 601 (a portion corresponding to the reference region R1), and a lower layer electrode positioned immediately below the upper layer electrode 601 A part of 650 (part corresponding to the reference region R1) forms a set of piezoelectric elements in which a piezoelectric body is sandwiched between upper and lower electrodes.

  Here, for convenience, the piezoelectric elements formed in the individual reference regions R1 to R12 are represented using the same reference numerals 601 to 612 as the upper layer electrodes. For example, the piezoelectric element 601 is formed at the position of the upper layer electrode 601, and the piezoelectric element 602 is formed at the position of the upper layer electrode 602. Therefore, FIG. 14A is a plan view showing the arrangement of 12 sets of piezoelectric elements 601 to 612. Here, the piezoelectric elements 601 to 612 are a first attribute element to a twelfth attribute element, respectively.

  As a result, in the inertial sensor shown in FIG. 14, the individual detection elements constituting the operation element group generate positive or negative charges according to the stretching stress along the longitudinal direction of the plate-like bridge portions 120 and 130. It is comprised by the piezoelectric elements 601-612. In the case of the embodiment shown here, as the layered piezoelectric body 600, a type of piezoelectric body that generates polarization in the vertical direction in accordance with the stretching stress generated in the layer direction is used.

  More specifically, when a stress extending in the layer direction is applied, a positive charge is generated on the upper electrode side, and a negative charge is generated on the lower electrode side. When a stress contracting in the layer direction is applied, a negative charge is applied on the upper electrode side and the lower electrode is applied. A piezoelectric body that generates positive charges on the side is used. In addition, since the lower layer electrode 650 is common to the twelve pairs of piezoelectric elements 601 to 612, if the lower layer electrode 650 is used while being grounded, a positive charge is generated on the upper layer electrode side when stress extending in the layer direction acts. When a stress that occurs and shrinks in the layer direction acts, negative charges are generated on the upper electrode side. If a predetermined addition / subtraction is performed on the charges thus generated, an acceleration acting in a predetermined coordinate axis direction can be detected.

  As shown in FIG. 14 (b), this inertial sensor is provided with a detection circuit 510, which can perform addition / subtraction on the generated charges described above. In FIG. 14B, the detection circuit 510 is shown as a simple block, but a specific circuit diagram will be described later.

  As shown in the figure, wiring is provided between the detection circuit 510 and the lower layer electrode 650 and the twelve upper layer electrodes 601 to 612 (only three upper layer electrodes 610 to 612 are shown in the figure). The positive or negative charges generated in the upper layer electrodes 601 to 612 are taken out by the detection circuit 510 through this wiring. Actually, each wiring can be formed by a conductive pattern formed on the upper surface of the layered piezoelectric body 600 together with each upper layer electrode. In addition, when the basic structure 100 is configured by a silicon substrate, the detection circuit 510 can be formed on the silicon substrate (for example, the plate member 110 for the fixing portion).

  FIG. 15 is a circuit diagram showing an example of the detection circuit 510 used in the embodiment shown in FIG. As shown in the figure, this detection circuit 510 is composed of three sets of addition / subtraction circuits, an addition / subtraction circuit shown in FIG. 15 (a), an addition / subtraction circuit shown in FIG. 15 (b), and an addition / subtraction circuit shown in FIG. 15 (c). Yes. In this circuit diagram, a rectangle indicated by reference numeral “600” indicates a part of the piezoelectric body 600, and a line segment indicated by reference numeral “650” indicates a part of the lower layer electrode 650. As described above, the piezoelectric body 600 and the lower layer electrode 650 are formed over the entire surface of the basic structure 100 and are members common to the 12 sets of piezoelectric elements. However, the piezoelectric body 600 and the lower layer electrode 650 correspond to the reference regions R1 to R12. The portion is a component of each piezoelectric element.

  As described above, each piezoelectric element is represented by the same reference numeral as that of the upper layer electrode. For example, in the circuit diagram of FIG. 15 (a), the upper layer electrode 601 and the piezoelectric body 600 therebelow. And a portion indicated by a part of the lower layer electrode 650 thereunder correspond to the piezoelectric element 601 (that is, the first attribute element). For all the 12 sets of piezoelectric elements 601 to 612, the lower layer electrode 650 is common and all are grounded. On the other hand, charges generated in the upper layer electrodes 601 to 612 are given to predetermined difference circuits 621, 622, and 623, respectively.

  Charges generated in the upper layer electrodes of a pair of piezoelectric elements connected in parallel to each other are collected at the same terminal of the same differential circuit. This corresponds to a process of adding charges generated in both upper layer electrodes. For example, in the circuit diagram shown in FIG. 15A, the charges generated in the upper layer electrodes 601 and 606 of the pair of piezoelectric elements are added and given to the positive terminal of the difference circuit 621. Similarly, charges generated in the upper layer electrodes 603 and 604 of the pair of piezoelectric elements are added and given to the negative terminal of the difference circuit 621. The difference circuit 621 performs subtraction considering the sign of the charge amount given to the positive terminal and the charge amount given to the negative terminal, and the result is output to the output terminal T31 as the x-axis detection voltage Vx. Output. Since the subtraction takes the sign into account, for example, when a positive charge is given to the positive terminal and a negative charge is given to the negative terminal, the sum of the absolute values of both charges is actually output. Will be.

  If the piezoelectric elements 601 to 612 are referred to as the first attribute element to the twelfth attribute element, respectively, the addition / subtraction circuit shown in FIG. 15 (a) has the generated attribute of the first attribute element (piezoelectric element 601) and the sixth attribute element ( Based on the difference between the sum of the generated charge of the piezoelectric element 606) and the sum of the generated charge of the third attribute element (piezoelectric element 603) and the generated charge of the fourth attribute element (piezoelectric element 604), the x axis Addition / subtraction processing is performed in which the acceleration αx (force fx) acting in the direction is detected and output to the output terminal T31 as the x-axis detection voltage Vx.

  Similarly, the addition / subtraction circuit shown in FIG. 15B includes the sum of the charge generated by the seventh attribute element (piezoelectric element 607) and the charge generated by the twelfth attribute element (piezoelectric element 612) and the ninth attribute element (piezoelectric element). Based on the difference between the charge generated by the element 609) and the sum of the charge generated by the tenth attribute element (piezoelectric element 610), the acceleration αy (force fy) acting in the y-axis direction is detected, and the output terminal T32 Addition / subtraction processing for outputting as y-axis detection voltage Vy is performed.

  In addition, the addition / subtraction circuit shown in FIG. 15C includes the sum of the charge generated by the fifth attribute element (piezoelectric element 605) and the charge generated by the eleventh attribute element (piezoelectric element 611), and the second attribute element (piezoelectric element). 602) and the sum of the generated charges of the eighth attribute element (piezoelectric element 608) and the acceleration αz (force fz) acting in the z-axis direction is detected and applied to the output terminal T33. Addition / subtraction processing for outputting as the z-axis detection voltage Vz is performed.

  The reason why each coordinate axis direction component αx, αy, αz of the applied acceleration can be detected by each addition / subtraction circuit shown in FIG. 15 can be easily understood by referring to the list shown in FIG. That is, when each piezoelectric element 601 to 612 is made to correspond to each reference region R1 to R12 in the list of FIG. 8, when the corresponding column is “+” (extended stress generation), a positive charge is applied to the upper layer electrode. If the corresponding column is “-” (shrinking stress is generated), a negative charge is generated in the upper electrode, and if the corresponding column is “0” (no significant expansion / contraction), there is no significant charge generation. Will show.

  Therefore, first, when the acceleration + αx in the positive x-axis direction acts on the weight body 150 and the displacement Δx (+) in the positive x-axis direction occurs on the weight body 150 as shown in FIG. Think about it. In this case, charges having the polarities shown in the respective columns of Δx (+) in the list of FIG. 8 are generated in the upper layer electrodes 601 to 612 of the piezoelectric elements shown in FIG.

  For example, in the addition / subtraction circuit shown in FIG. 15A, the upper layer electrodes 601 and 606 have positive charges (R1 and R6 in the corresponding column Δx (+) in FIG. 8 are both “+”), and the upper layer electrodes 603 and 604 Since negative charges (R3 and R4 in the corresponding column Δx (+) in FIG. 8 are all “−”) are generated, the difference circuit 621 generates the four sets of upper layer electrodes 601, 606, 603, and 604. A voltage corresponding to the sum of absolute values of the generated positive and negative charges is output to the output terminal T31 as the x-axis detection voltage Vx. On the contrary, when the acceleration −αx in the negative x-axis direction is applied, the displacement Δx (−) in the reverse direction is generated, so that the sign of each of the above columns is reversed, and the difference circuit 621 has four sets of upper layers. A negative voltage corresponding to the sum of absolute values of positive and negative charges generated at the electrodes 601, 606, 603, and 604 is output to the output terminal T31 as the x-axis detection voltage Vx.

  Thus, the x-axis detection voltage Vx output from the adder / subtractor circuit shown in FIG. 15A is the direction of the x-axis direction component αx of the acceleration acting on the weight 150 (whether the x-axis is positive or negative). It shows the size. Moreover, when only the x-axis direction component αx of the acceleration is acting, no significant detection voltage is output from the addition / subtraction circuit shown in FIG. 15 (b) or the addition / subtraction circuit shown in FIG. 15 (c).

  For example, in the addition / subtraction circuit shown in FIG. 15B, negative charge is generated in the upper layer electrode 607 (R7 in the corresponding column Δx (+) in FIG. 8 is “−”), but positive charge is generated in the upper layer electrode 612. (R12 in the corresponding column Δx (+) in FIG. 8 is “+”), the charge given to the positive terminal of the difference circuit 622 is canceled out to zero. Similarly, a positive charge (R9 in the corresponding column Δx (+) in FIG. 8 is “+”) is generated in the upper layer electrode 609, but a negative charge (in the corresponding column Δx (+) in FIG. 8 is generated in the upper layer electrode 610. Since “−”) occurs in R10, the charge given to the negative terminal of the difference circuit 622 is also canceled out to zero. Therefore, the y-axis detection voltage Vy output from the difference circuit 622 to the output terminal T32 is zero.

  On the other hand, in the addition / subtraction circuit shown in FIG. 15C, the generated charges of the upper layer electrodes 605, 611, 602, and 608 are all 0 (R5, R11, R2, R8 in the corresponding column Δx (+) in FIG. 8). Are all “0”). Therefore, the z-axis detection voltage Vz output from the difference circuit 623 to the output terminal T33 is zero.

  Although a specific description is omitted, when the acceleration αy in the y-axis direction acts on the weight body 150 for the same reason, it is output from the addition / subtraction circuit 622 shown in FIG. 15B to the output terminal T32. The y-axis detection voltage Vy indicates the direction and magnitude of the acceleration αy. In addition, at this time, a significant detection voltage is not output from the addition / subtraction circuit shown in FIG. 15 (a) or the addition / subtraction circuit shown in FIG. 15 (c). When the acceleration αz in the z-axis direction acts on the weight 150, the z-axis detection voltage Vz output from the addition / subtraction circuit 623 shown in FIG. 15C to the output terminal T33 is the direction of the acceleration αz. And it will show the size. In addition, at this time, a significant detection voltage is not output from the addition / subtraction circuit shown in FIG. 15 (a) or the addition / subtraction circuit shown in FIG. 15 (b).

  In this way, considering the operation of the detection circuit 510 shown in FIG. 15 with reference to the list of FIG. 8, the x-axis detection voltage Vx output from the addition / subtraction circuit of FIG. Only the x-axis direction component αx of the acceleration not including the y-axis detection voltage Vy output from the addition / subtraction circuit of FIG. 15 (b) includes only the y-axis direction component αy of the acceleration not including the other-axis component. It can be understood that the z-axis detection voltage Vz output from the addition / subtraction circuit of FIG. 15 (c) shows only the z-axis direction component αz of the acceleration not including the other-axis component. As described above, according to the inertial sensor according to the embodiment shown here, each coordinate axis direction component αx, αy, αz of acceleration is detected independently and with high detection sensitivity without receiving interference from other axis components. It becomes possible to do. In addition, since the detected value is obtained as a differential voltage that has passed through the differential circuit, detection that offsets the influence of environmental changes such as temperature is possible.

  In the above-described operation, the orthographic projection image on the xy plane of the operation element group (piezoelectric elements 601 to 606) arranged in the first plate-like bridge portion 120 is projected on the first longitudinal axis Ly. An orthographic projection image on the xy plane of the operating element group (piezoelectric elements 607 to 612) disposed in the second plate-like bridge portion 130 having a pattern that is line symmetric with respect to the image is the second longitudinal direction. It is premised on having a pattern that is line symmetric with respect to the projected image of the axis Lx.

  If such a symmetry is provided in the arrangement pattern of each piezoelectric element, the effect of canceling the positive and negative charges generated by a specific pair of piezoelectric elements can be obtained. Detection operation that eliminates the above becomes possible. However, if the length, width, piezoelectric efficiency, etc. in the longitudinal direction of the specific piezoelectric element pair are appropriately adjusted, it is possible to obtain an effect of canceling the generated charges even if the symmetry is not necessarily maintained. In practicing the present invention, the symmetry of the element arrangement pattern is not an essential requirement. However, in practice, it is preferable to obtain an element arrangement pattern having the above symmetry.

  Further, the inertial sensor detection circuit 510 shown in FIG. 14 is not necessarily limited to the circuit shown in FIG. 15, and based on the results shown in the list of FIG. Any other circuit may be adopted as long as the circuit can be used.

  For example, FIG. 16 is a circuit diagram showing another example of the detection circuit 510 used in the embodiment shown in FIG. This detection circuit is composed of three sets of addition / subtraction circuits, an addition / subtraction circuit shown in FIG. 16 (a), an addition / subtraction circuit shown in FIG. 16 (b), and an addition / subtraction circuit shown in FIG. 16 (c).

  The addition / subtraction circuit shown in FIG. 16A includes the sum of the charge generated by the ninth attribute element (piezoelectric element 609A) and the charge generated by the twelfth attribute element (piezoelectric element 612A) and the seventh attribute element (piezoelectric element 607A). , And the acceleration αx (force fx) acting in the x-axis direction is detected based on the difference between the generated charge and the sum of the generated charges of the tenth attribute element (piezoelectric element 610A) and the output terminal T41 receives the x-axis Addition / subtraction processing to output as the detection voltage Vx is performed.

  Similarly, the addition / subtraction circuit shown in FIG. 16B includes the sum of the charge generated by the first attribute element (piezoelectric element 601A) and the charge generated by the fourth attribute element (piezoelectric element 604A) and the third attribute element (piezoelectric element). Based on the difference between the generated charge of the element 603A) and the sum of the generated charge of the sixth attribute element (piezoelectric element 606A), the acceleration αy (force fy) acting in the y-axis direction is detected, and the output terminal T42 Addition / subtraction processing for outputting as y-axis detection voltage Vy is performed.

  16C includes a fourth attribute element (piezoelectric element 604B), a fifth attribute element (piezoelectric element 605), a sixth attribute element (piezoelectric element 606B), and a tenth attribute element (piezoelectric element). 610B), the eleventh attribute element (piezoelectric element 611) and the twelfth attribute element (piezoelectric element 612B), and the first attribute element (piezoelectric element 601B), second attribute element (piezoelectric element 602), The difference between the third attribute element (piezoelectric element 603B), the seventh attribute element (piezoelectric element 607B), the eighth attribute element (piezoelectric element 608) and the ninth attribute element (piezoelectric element 609B) Based on this, the acceleration αz (force fz) acting in the z-axis direction is detected, and an addition / subtraction process is performed to output it to the output terminal T43 as the z-axis detection voltage Vz.

  Although detailed description is omitted here, the reason why each coordinate axis direction component αx, αy, αz of the applied acceleration can be independently detected without interference from other axes by the respective addition / subtraction circuits shown in FIG. However, it can be easily understood by referring to the list shown in FIG.

  Note that the symbols A and B are attached to the end of the symbols of some of the piezoelectric elements (upper layer electrodes) constituting the adder / subtracter circuit shown in FIG. 16, but this symbol is detected as described in §3. When a plurality of the same attribute elements are used in the circuit 510, the two are distinguished from each other. For example, the ninth attribute element 609A is used in the addition / subtraction circuit shown in FIG. 16 (a), and the ninth attribute element 609B is used in the bridge circuit shown in FIG. 16 (c). Each element is a ninth attribute element arranged in the reference region R9, but is an electrically independent separate piezoelectric element.

  As described above, in carrying out the present invention, it is not always necessary to arrange only one operation element in one reference area. If a plurality of the same attribute elements are required, the same reference area is included. A plurality of different operating elements may be arranged. Even in such a case, it is preferable that the arrangement pattern of each piezoelectric element is provided with symmetry so that an effect of canceling generated charges related to a specific piezoelectric element pair can be obtained.

  In the embodiment described so far, when a stress extending in the layer direction is applied, a positive charge is generated on the upper electrode side, and a negative charge is generated on the lower electrode side. Conversely, when a stress contracting in the layer direction is applied, the upper electrode side In this example, a piezoelectric body 600 that generates a negative charge and a positive charge on the lower electrode side is used. Of course, a piezoelectric body having a reverse polarization characteristic may be used. Alternatively, the 12 sets of piezoelectric elements may have different polarization characteristics.

  Further, as described in §2-2, in the example shown in FIG. 4, the 12 sets of reference regions R1 to R12 are all formed on the upper surface of the first plate-like bridge portion 120 or the second plate-like bridge portion 130 (see FIG. 8), the eight armpit arrangement regions R1, R3, R4, R6, R7, R9, R10, and R12 are not necessarily defined on the upper surface of the plate-like bridge portion. However, it may be defined on the side surface of the plate-like bridge portion, or may be defined as a bent continuous region from the upper surface to the side surface.

  FIG. 17 is a side cross-sectional view showing an example in which some variations are provided in the arrangement mode of the upper layer electrode in accordance with such variations relating to the arrangement of the reference regions. FIG. 17A is a side sectional view showing a section of the second plate-like bridge portion 130 shown in FIG. As shown in the figure, a lower layer electrode 650 and a layered piezoelectric body 600 are laminated on the upper surface of the plate-like bridge portion 130, and three upper layer electrodes 610, 611, 612 are arranged on the upper surface. Therefore, the polarization phenomenon of the piezoelectric body 600 occurs in the vertical direction of the figure.

  On the other hand, in the embodiment shown in FIG. 17B, the upper layer electrode 610b and the upper layer electrode 612b are arranged on the side surface. In this embodiment, the lower layer electrode 650b is formed on the side surface as well as the upper surface of the plate-like bridge portion 130, and the layered piezoelectric body 600b is formed on the surface of the lower layer electrode 650b. That is, in the sectional side view, both the lower layer electrode 650b and the piezoelectric body 600b have a “U” shape, and are integrally formed from the upper surface of the plate-like bridge portion 130 to the left and right side surfaces. The arrangement of the three upper layer electrodes is the same as that the center upper layer electrode 611b is formed on the upper surface of the plate-like bridge portion 130 via the lower layer electrode 650b and the piezoelectric body 600b. 612b are formed on the side surface of the plate-like bridge portion 130 via the lower layer electrode 650b and the piezoelectric body 600b. FIG. 17B shows only three upper layer electrodes 610b to 612b, but the arrangement of the other nine upper layer electrodes is the same.

  In short, the lower layer electrode 650b is formed on the side surfaces as well as the upper surfaces of the first plate-like bridge portion 120 and the second plate-like bridge portion 130, and the piezoelectric body 600b is formed on the surface of the lower layer electrode 650b, and has the second attribute. The upper layer electrodes 602b, 605b, 608b, and 611b constituting the element, the fifth attribute element, the eighth attribute element, and the eleventh attribute element are formed by disposing the lower layer electrode 650b and the piezoelectric body 600b on the upper surfaces of the plate-like bridge portions 120 and 130, respectively. And the upper layer constituting the first attribute element, the third attribute element, the fourth attribute element, the sixth attribute element, the seventh attribute element, the ninth attribute element, the tenth attribute element, and the twelfth attribute element. Electrodes 601b, 603b, 604b, 606b, 607b, 609b, 610b, and 612b are provided with the lower layer electrode 650b and the piezoelectric body 600b on the side surfaces of the plate-like bridge portions 120 and 130, respectively. It may be as being formed by.

  In the case of the example shown in FIG. 17 (b), each part of the piezoelectric body 600b causes a polarization phenomenon in the thickness direction thereof, so that the part formed on the upper surface of the plate-like bridge portion 130 is A polarization phenomenon occurs in the direction, and a polarization phenomenon occurs in the left-right direction of the drawing for the portion formed on the side surface of the plate-like bridge portion 130. Therefore, the stress generated in each part of the plate-like bridge portion 130 does not change that charges having a predetermined polarity are generated as in the above-described embodiments. The expansion / contraction state of each part of the plate-like bridge parts 120 and 130 shown in FIGS. 5 to 7 does not change on the side surface, so that the acceleration can be detected by the detection circuit similar to the detection circuit 510 described so far. is there.

  Compared to the embodiment shown in FIG. 17 (a), the embodiment shown in FIG. 17 (b) has a larger area of each upper electrode, and therefore the amount of charge generated in the upper electrode group also increases. Therefore, the detection sensitivity of the latter is improved compared to the former, but in the latter case, it is necessary to form a lower layer electrode, a piezoelectric body, and an upper layer electrode not only on the upper surface of the plate-like bridge portions 120 and 130 but also on the side surface. As a result, the manufacturing cost will rise.

  On the other hand, in the embodiment shown in FIG. 17 (c), the upper layer electrode 610c and the upper layer electrode 612c are arranged so as to be continuous from the upper surface to the side surface. Also in this embodiment, similarly to the embodiment shown in FIG. 17B, the lower layer electrode 650c is formed on the side surface as well as the upper surface of the plate-like bridge portion 130, and the plate-like piezoelectric body 600c is formed on the surface of the lower layer electrode 650c. Is formed. Therefore, in the side sectional view, the lower layer electrode 650c and the piezoelectric body 600c have a “U” shape, and are integrally formed from the upper surface of the plate-like bridge portion 130 to the left and right side surfaces.

  Here, the arrangement of the three upper layer electrodes is the same as that the central upper layer electrode 611c is formed on the upper surface of the plate-like bridge portion 130 via the lower layer electrode 650c and the piezoelectric body 600c. 610c and 612c are formed from the upper surface to the side surface of the plate-like bridge portion 130 via the lower layer electrode 650c and the piezoelectric body 600c. FIG. 17 (c) shows only three upper layer electrodes 610c to 612c, but the arrangement of the other nine upper layer electrodes is the same.

  In short, the lower layer electrode 650c is formed on the side surfaces as well as the upper surfaces of the first plate-like bridge portion 120 and the second plate-like bridge portion 130, and the layered piezoelectric body 600c is formed on the surface of the lower layer electrode 650c. Upper layer electrodes 602c, 605c, 608c, and 611c constituting the second attribute element, the fifth attribute element, the eighth attribute element, and the eleventh attribute element are disposed on the upper surface of each plate-like bridge portion 120 and 130, and the lower layer electrode 650c and the piezoelectric body. The first attribute element, the third attribute element, the fourth attribute element, the sixth attribute element, the seventh attribute element, the ninth attribute element, the tenth attribute element, and the twelfth attribute element. The upper layer electrodes 601c, 603c, 604c, 606c, 607c, 609c, 610c, 612c are connected to the lower layer electrode 650c from the upper surface to the side surface of the plate-like bridge portions 120, 130. It may be as being formed through a fine piezoelectric 600c.

  As described above, also in the case of the example shown in FIG. 17 (c), each part of the piezoelectric body 600c causes a polarization phenomenon in the thickness direction, and therefore, a detection circuit similar to the detection circuit 510 described so far. Thus, acceleration can be detected.

  Compared with the embodiment shown in FIG. 17 (b), in the embodiment shown in FIG. 17 (c), since the area of each upper layer electrode can be secured more widely, the amount of electric charge generated in the upper layer electrode group is also that much. The detection sensitivity is further improved. However, since it is necessary to form the upper electrode on the left and right in the figure from the upper surface to the side surface, the manufacturing cost will further increase.

  Of course, the arrangement of the upper layer electrodes in the embodiment shown in FIGS. 17 (a) to 17 (c) can be combined for each part. In FIG. 17 (d), the arrangement shown in FIG. 17 (b) is adopted for the right half, and the arrangement shown in FIG. 17 (c) is adopted for the left half. In this embodiment, the piezoelectric body is divided into two portions 600d1 and 600d2 instead of an integral structure.

  Specifically, in the embodiment shown in FIG. 17 (d), the lower layer electrode 650d is formed on the side surface as well as the upper surface of the plate-like bridge portion 130, and piezoelectric bodies 600d1 and 600d2 are formed on the surface. The piezoelectric body 600d1 is formed at a position covering the right side surface of the lower layer electrode 650d, and the piezoelectric body 600d2 is formed at a position covering the upper surface and the left side surface of the lower layer electrode 650d. In the arrangement of the three upper layer electrodes, the central upper layer electrode 611d is formed on the upper surface of the plate-shaped bridge portion 130 via the lower layer electrode 650d and the piezoelectric body 600d2, and the upper layer electrode 612d is formed of the plate-shaped bridge portion. 130 is formed via a lower layer electrode 650d and a piezoelectric body 600d1, and the upper layer electrode 610d is formed from the upper surface of the plate-shaped bridge portion 130 to the left side surface via the lower layer electrode 650d and the piezoelectric body 600d2. Yes.

  As in the embodiment shown in FIG. 17 (d), the arrangement of the upper layer electrodes does not necessarily have to be symmetrical. However, as described above, the effect of canceling the generated charges related to a specific piezoelectric element pair is reduced. In order to obtain it, it is preferable to employ an arrangement that is symmetric as in the embodiment shown in FIGS. 17 (a), (b), and (c).

  In addition, the piezoelectric element does not necessarily have an integral structure, and as shown in FIG. 17 (d), independent elements may be arranged at positions corresponding to the upper layer electrodes. Above, the manufacturing process becomes easier with a single structure. Similarly, the lower layer electrodes may be arranged separately and independently at positions corresponding to the upper layer electrodes. However, practically, the manufacturing process is easier when the single layer structure is used.

<<< §5. Angular velocity sensor using piezoelectric element >>
So far, the acceleration sensor using only the detection element as the operation element group has been described. Here, an embodiment in which an angular velocity sensor is configured by using a drive element as an operation element group in addition to a detection element will be described.

  In §3, an embodiment of an acceleration sensor using a piezoresistive element as a detection element is described. In §4, an embodiment of an acceleration sensor using a piezoelectric element as a detection element is described. Each of these detection elements played a role of detecting the displacement of the weight body 150 generated based on the applied acceleration based on the bending generated in a predetermined portion of the plate-like bridge portions 120 and 130. The drive element used for the angular velocity sensor described in §5, on the contrary, plays a role of vibrating the weight body 150 in a predetermined direction by periodically bending the predetermined portions of the plate-like bridge portions 120 and 130. It will be.

  Actually, the angular velocity sensor described here has the same structure as the acceleration sensor described in §4, and the structure is as shown in FIG. However, the contents of the detection circuit 510 are slightly different. As described in §4, the 12 sets of piezoelectric elements 601 to 612 used in the acceleration sensor shown in FIG. 14 have individual upper layers according to the stretching stress along the longitudinal direction of the plate-like bridge portions 120 and 130. This is a type in which positive and negative polarization occurs between the electrodes 601 to 612 and the common lower layer electrode 650. If the lower layer electrode 650 is grounded and used, positive or negative charges are generated in the upper layer electrodes 601 to 612. Therefore, a function as a detection element for detecting stress generated in each part based on the generated charges is provided. Can fulfill.

  On the other hand, if an AC drive signal is given to the piezoelectric elements 601 to 612, the function as a drive element can be achieved. That is, when a voltage having a predetermined polarity is applied between the individual upper layer electrodes 601 to 612 and the common lower layer electrode 650, the direction extending in accordance with the polarity along the longitudinal direction of the plate-like bridge portions 120 and 130, or Stress in the shrinking direction is generated. Specifically, in the case of the example shown in FIG. 14, since the lower layer electrode 650 is grounded, when a positive voltage is applied to the upper layer electrode side, stress in the direction extending in the longitudinal direction is generated, and the upper layer electrode side When a negative voltage is applied, stress is generated in the direction of contraction in the longitudinal direction.

  Therefore, referring to the list of FIG. 8, if a voltage having a predetermined polarity is applied to each upper layer electrode 601 to 612, the weight body 150 can be displaced in the predetermined axial direction. For example, when it is desired to cause the weight body 150 to generate the x-axis positive direction displacement Δx (+), refer to the column of Δx (+) in this list, and the reference regions R1, R6 marked with “+” , R9, R12, a positive voltage is applied to the upper electrodes 601, 606, 609, 612 of the piezoelectric elements, and the piezoelectric elements are arranged in the reference regions R3, R4, R7, R10 marked with “-”. A negative voltage may be applied to the upper layer electrodes 603, 604, 607, and 610 of the piezoelectric element. A voltage is applied to the upper electrodes 602, 605, 608, 611 of the piezoelectric elements arranged in the reference regions R2, R5, R8, R11 in which “0” is written in the Δx (+) column of the list. There is no need.

  Subsequently, when a voltage having a polarity opposite to that described above is applied to each of the upper layer electrodes 601 to 612, the weight body 150 generates an x-axis negative direction displacement Δx (−). Therefore, an AC drive signal (for example, a sine wave signal or a rectangular wave signal) having a predetermined period is provided to the upper layer electrodes 601, 606, 609, and 612, and the upper layer electrodes 603, 604, 607, and 610 are provided. If an AC drive signal having the same period and a second phase opposite to the first phase is applied, the weight body 150 can be vibrated in the x-axis direction.

  Similarly, the upper electrodes 601, 604, 607, 612 of the piezoelectric elements arranged in the reference regions R 1, R 4, R 7, R 12 marked with “+” in the column of Δy (+) in the list of FIG. 3 is applied to the upper layer electrodes 603, 606, 609, and 610 of the piezoelectric elements disposed in the reference regions R3, R6, R9, and R10 marked with “−”. If the AC drive signal having the same period and the fourth phase opposite to the phase 3 is given, the weight body 150 can be vibrated in the y-axis direction.

  Further, the upper electrodes 604, 605, 606 of the piezoelectric elements arranged in the reference regions R4, R5, R6, R10, R11, R12 in which “+” is marked in the column of Δz (+) in the list of FIG. 610, 611, and 612 are supplied with an AC drive signal having a predetermined period and having a fifth phase, and piezoelectric elements arranged in reference regions R1, R2, R3, R7, R8, and R9 marked with “-” are displayed. If an AC drive signal with the same period having the sixth phase opposite to the fifth phase is given to the upper layer electrodes 601, 602, 603, 607, 608, 609, the weight body 150 is vibrated in the z-axis direction. be able to.

  As described above, in the list of FIG. 8, the AC drive signal having the first phase is applied to all the upper layer electrodes corresponding to the column marked “+”, and all the upper layers corresponding to the column marked “−”. The driving method of vibrating the weight body 150 in a predetermined coordinate axis direction by applying an AC driving signal having the second phase to the electrodes has been described. However, it is not always necessary to apply an AC driving signal to all the upper layer electrodes. Alternatively, an AC drive signal may be given only to some upper layer electrodes. However, in order to stabilize the vibration of the weight body 150, it is preferable to employ a drive system in which AC drive signals having the same phase are supplied to at least two sets of upper layer electrodes.

  FIG. 18 is a circuit diagram showing a driving circuit configured based on such a basic principle. FIG. 18A shows a driving circuit for causing the weight 150 to generate vibration Ux in the x-axis direction. Here, the AC drive signal sources 641 and 642 are signal sources that generate sinusoidal AC with the same period, but the phases of both are reversed. Therefore, as shown in the drawing, for the upper layer electrodes 601 and 606 (electrodes corresponding to the columns marked with “+” in the Δx (+) row of the list), the first phase is supplied from the AC drive signal source 641. The AC drive signal having, and the upper layer electrodes 603 and 604 (electrodes corresponding to the columns marked with “-” in the Δx (+) row of the list) are supplied from the AC drive signal source 642. An AC drive signal having a second phase opposite to the first phase is supplied. As a result, the weight 150 generates vibration Ux in the x-axis direction.

  Similarly, FIG. 18B shows a driving circuit for causing the weight 150 to generate a vibration Uy in the y-axis direction. Again, the AC drive signal sources 643 and 644 are signal sources that generate sinusoidal alternating current with the same period, but the phases of both are reversed. Therefore, as shown in the figure, for the upper layer electrodes 607 and 612 (electrodes corresponding to the columns marked with “+” in the row of Δy (+) in the list), the AC drive signal source 643 supplies the third phase. The AC drive signal having, and the upper layer electrodes 609 and 610 (electrodes corresponding to the columns marked with “−” in the row of Δy (+) of the list) from the AC drive signal source 644 An AC drive signal having a fourth phase opposite to the third phase is supplied. As a result, the weight 150 generates vibration Uy in the y-axis direction.

  FIG. 18C shows a driving circuit for causing the weight body 150 to generate a vibration Uz in the z-axis direction. Again, the AC drive signal sources 645 and 646 are signal sources that generate sinusoidal alternating current with the same period, but the phases of both are reversed. Therefore, as shown in the figure, for the upper layer electrodes 605 and 611 (electrodes corresponding to the columns marked with “+” in the row of Δz (+) in the list), the fifth phase is supplied from the AC drive signal source 645. AC drive signal having, is supplied from the AC drive signal source 646 to the upper layer electrodes 602 and 608 (electrodes corresponding to the columns marked with “-” in the row of Δz (+) in the list). An AC drive signal having a sixth phase opposite to the fifth phase is supplied. As a result, the weight body 150 generates vibration Uz in the z-axis direction.

  Thus, if the driving circuit shown in FIGS. 18 (a), (b), and (c) is incorporated in the detection circuit 510 of the acceleration sensor shown in FIG. 14, the weight body 150 vibrates in the desired coordinate axis direction. Therefore, as described later, the acceleration sensor can be diverted to an angular velocity sensor.

  Note that the driving circuit that can be used to divert the acceleration sensor shown in FIG. 14 to the angular velocity sensor is not necessarily limited to the circuit shown in FIG. 18, and based on the results shown in the list of FIG. Other circuits may be adopted as long as the weight body 150 can vibrate in the desired coordinate axis direction.

  For example, the circuit illustrated in FIG. 19 is an example of a circuit that performs a function equivalent to that of the driving circuit illustrated in FIG. That is, FIG. 19A is a driving circuit for generating a vibration Ux in the x-axis direction in the weight body 150, and FIG. 19B is a circuit for driving the vibration Uy in the y-axis direction in the weight body 150. FIG. 19C shows a driving circuit for generating the vibration Uz in the z-axis direction in the weight body 150. Here, the AC drive signal sources 651 to 656 are signal sources that generate sinusoidal AC with the same cycle, but the phases of the AC drive signal sources 651 and 652 are reversed, and the AC drive signal sources 653 and 654 The phase is reversed, and the phases of the AC drive signal sources 655 and 656 are reversed.

  Further, the symbol A or B is attached to the end of the reference numerals of some upper layer electrodes shown in the circuit diagram shown in FIG. 19, and this symbol is used for driving as described in §4. This is for distinguishing between a plurality of the same attribute elements in the circuit. For example, an upper layer electrode 609A for the ninth attribute element is used in the drive circuit shown in FIG. 19A, and an upper layer for the ninth attribute element is used in the drive circuit shown in FIG. An electrode 609B is used. Each element is a ninth attribute element arranged in the reference region R9, but is an electrically independent separate piezoelectric element.

  The driving circuit shown in FIG. 19 performs the same function as the driving circuit shown in FIG. 18, and the driving operation that vibrates the weight body 150 in the direction of each coordinate axis is possible, see the table in FIG. It will be easy to understand.

  That is, the driving circuit in FIG. 19A supplies the first phase signal to the two sets of electrodes 609A and 612A corresponding to the column marked with “+” in the Δx (+) row of the list. In addition, the second phase signal is supplied to the two sets of electrodes 607A and 610A corresponding to the column marked with “−”. Similarly, the driving circuit of FIG. 19B applies the third phase signal to the two sets of electrodes 601A and 604A corresponding to the column marked with “+” in the Δy (+) row of the list. In addition to the supply, the circuit supplies a fourth phase signal to the two sets of electrodes 603A and 606A corresponding to the column marked with “−”. In addition, the driving circuit of FIG. 19 (c) includes fifth electrodes on all the electrodes 604B, 605, 606B, 610B, 611, and 612B corresponding to the columns marked with “+” in the Δz (+) row of the list. And a sixth phase signal to all the electrodes 601B, 602, 603B, 607B, 608, and 609B corresponding to the columns marked with “−”.

  Subsequently, by incorporating a driving circuit as illustrated in FIG. 18 or 19 in the detection circuit 510 of the acceleration sensor shown in FIG. 14, the weight body 150 can be vibrated in a desired coordinate axis direction. A specific method for diverting the acceleration sensor to an angular velocity sensor will be described.

  In general, the detection of the angular velocity in the inertial sensor defines three axes orthogonal to each other, and acts on the weight body in the second axial direction in a state where the weight body is vibrated in the first axis direction. If the Coriolis force is measured, the Coriolis force is performed based on the basic principle that the Coriolis force indicates an angular velocity acting around the third axis with respect to the sensor. The angular velocity sensor according to the present invention also performs angular velocity detection based on the basic principle.

  Therefore, in the angular velocity sensor according to the present invention, the individual elements constituting the operation element group arranged in each reference region R1 to R12 of the basic structure 100 shown in FIG. A detection element that electrically detects a stress acting in the longitudinal direction of 130, and a drive element that applies a stress in the longitudinal direction to the plate-like bridge portions 120 and 130 at each arrangement position based on a given electric signal; , By. In the detection circuit, an AC drive signal is applied to the drive element, so that the weight 150 is vibrated in the first axial direction based on the detection result of the detection element. The Coriolis force acting in the second axial direction perpendicular to the first axis is obtained, and based on the Coriolis force, the Coriolis force acts around the third axis perpendicular to both the first axis and the second axis. Performs processing to detect angular velocity.

  In particular, in the case of an angular velocity sensor configured using an acceleration sensor (FIG. 14) using a piezoelectric element described in §4, each drive element that constitutes the operating element group responds to a given AC drive signal. The plate-shaped bridge portions 120 and 130 are each composed of a piezoelectric element that applies a stretching stress along the longitudinal direction, and the individual detection elements constituting the operation element group are arranged in the longitudinal direction of the plate-shaped bridge portions 120 and 130. The piezoelectric element generates a positive or negative charge according to the stretching stress along the axis. Then, the detection circuit applies an alternating current drive signal having a predetermined phase to the piezoelectric element constituting the drive element, thereby vibrating the weight body 150 in the first axial direction, and generating charge of the piezoelectric element constituting the detection element. By performing addition / subtraction, Coriolis force acting on the weight body in the second axial direction is obtained, and processing for outputting a detected value of angular velocity is performed based on the Coriolis force.

  For example, when the circuit shown in the circuit diagram of FIG. 18 is employed as the driving circuit incorporated in the detection circuit 510, the detection circuit 510 gives the first phase to the first attribute element 601 and the sixth attribute element 606. The AC drive signal 641 having the first phase and the AC drive signal 642 having the second phase opposite to the first phase are supplied to the third attribute element 603 and the fourth attribute element 604. Has an x-axis excitation function to vibrate in the x-axis direction. In addition, the detection circuit 510 provides an AC drive signal 643 having a third phase to the seventh attribute element 607 and the twelfth attribute element 612, and third signal to the ninth attribute element 609 and the tenth attribute element 610. By providing an AC drive signal 644 having a fourth phase opposite to the phase of the first phase, a weight axis 150 has a y-axis excitation function for vibrating the weight body 150 in the y-axis direction. An AC drive signal 645 having a fifth phase is given to the 11th attribute element 611, and an AC drive having a 6th phase opposite to the 5th phase is given to the 2nd attribute element 602 and the 8th attribute element 608. By providing the signal 646, the weight body 150 has a z-axis excitation function that vibrates in the z-axis direction.

  On the other hand, when the circuit shown in the circuit diagram of FIG. 19 is adopted as the driving circuit incorporated in the detection circuit 510, the detection circuit 510 gives the first phase to the ninth attribute element 609A and the twelfth attribute element 612A. The AC driving signal 651 having the first phase and the AC driving signal 652 having the second phase opposite to the first phase are supplied to the seventh attribute element 607A and the tenth attribute element 610A. Has an x-axis excitation function to vibrate in the x-axis direction. In addition, the detection circuit 510 gives an AC drive signal 653 having a third phase to the first attribute element 601A and the fourth attribute element 604A, and third signals to the third attribute element 603A and the sixth attribute element 606A. By providing an AC drive signal 654 having a fourth phase opposite to the phase of the first, it has a y-axis excitation function for vibrating the weight body 150 in the y-axis direction, and further includes a fourth attribute element 604B, An AC drive signal 655 having a fifth phase is applied to each of the fifth attribute element 605, the sixth attribute element 606B, the tenth attribute element 610B, the eleventh attribute element 611, and the twelfth attribute element 612B, and the first attribute element 601B The second attribute element 602, the third attribute element 603B, the seventh attribute element 607B, the eighth attribute element 608, and the ninth attribute element 609B each have an AC drive having a sixth phase opposite to the fifth phase. By giving the signal will have a z-axis excitation function of vibrating the weight body 150 in the z-axis direction.

  The detection circuit 510 requires a detection circuit for detecting the Coriolis force acting on the weight body 150 in addition to the drive circuit described above. As the detection circuit, the acceleration circuit described in §4 is used. The acceleration detection circuit provided in the sensor detection circuit 510 can be used as it is.

  For example, the three sets of addition / subtraction circuits shown in FIG. 15 output the acceleration αx in the x-axis direction acting on the weight body 150 as the x-axis detection voltage Vx in the acceleration sensor shown in FIG. Is output as the y-axis detection voltage Vy, and the acceleration αz in the z-axis direction is output as the z-axis detection voltage Vz. The x-axis detection voltage Vx, y-axis detection voltage Vy, The z-axis detection voltage Vz actually indicates the force fx in the x-axis direction, the force fy in the y-axis direction, and the force fz in the z-axis direction that acted on the weight body 150 based on the acceleration.

  Therefore, when the acceleration sensor shown in FIG. 14 is diverted to an angular velocity sensor, the x-axis detection voltage Vx, the y-axis detection voltage Vy, and the z-axis detection voltage Vz in the detection circuit shown in FIG. It shows the Coriolis force fy in the fx and y-axis directions and the Coriolis force fz in the z-axis direction. Therefore, in the angular velocity sensor described in §5, the circuit shown in FIG. 15 or 16 (or another circuit that performs an equivalent function) may be used as a detection circuit to detect the Coriolis force in each coordinate axis direction. be able to.

  For example, when the circuit shown in the circuit diagram of FIG. 15 is adopted as the detection circuit incorporated in the detection circuit 510, the detection circuit 510 has the generated charge of the first attribute element 601 and the generated charge of the sixth attribute element 606. And the Coriolis force fx acting on the weight body 150 in the x-axis direction is detected based on the difference between the sum of the two and the sum of the charge generated by the third attribute element 603 and the charge generated by the fourth attribute element 604 It has an x-axis detection function. The detection circuit 510 also includes the sum of the generated charge of the seventh attribute element 607 and the generated charge of the twelfth attribute element 612, and the sum of the generated charge of the ninth attribute element 609 and the generated charge of the tenth attribute element 610. And a y-axis detection function for detecting the Coriolis force fy acting on the weight 150 in the y-axis direction, and the generated attribute of the fifth attribute element 605 and the eleventh attribute element Based on the difference between the sum of the generated charge of 611 and the sum of the generated charge of the second attribute element 602 and the generated charge of the eighth attribute element 608, the weight 150 is acted on in the z-axis direction. A z-axis detection function for detecting the Coriolis force fz is provided.

  On the other hand, when the circuit shown in the circuit diagram of FIG. 16 is adopted as the detection circuit incorporated in the detection circuit 510, the detection circuit 510 has the generated charge of the ninth attribute element 609A and the generated charge of the twelfth attribute element 612A. And the Coriolis force fx acting in the x-axis direction on the weight body 150 is detected based on the difference between the sum of the two and the sum of the charge generated by the seventh attribute element 607A and the charge generated by the tenth attribute element 610A It has an x-axis detection function. The detection circuit 510 also includes the sum of the charge generated by the first attribute element 601A and the charge generated by the fourth attribute element 604A, and the sum of the charge generated by the third attribute element 603A and the charge generated by the sixth attribute element 606A. And a y-axis detection function for detecting the Coriolis force fy acting on the weight 150 in the y-axis direction, and further, a fourth attribute element 604B, a fifth attribute element 605, The total generated charges of the six attribute element 606B, the tenth attribute element 610B, the eleventh attribute element 611, and the twelfth attribute element 612B, the first attribute element 601B, the second attribute element 602, the third attribute element 603B, and the seventh attribute element A z-axis that detects a Coriolis force fz that has acted on the weight 150 in the z-axis direction based on the difference between the generated charges of the attribute element 607B, the eighth attribute element 608, and the ninth attribute element 609B. Detector It will have.

  Note that the piezoelectric element used in the detection circuit illustrated in FIG. 15 or FIG. 16 and the piezoelectric element used in the drive circuit illustrated in FIG. 18 or FIG. 19 have the same attribute element (in the same reference region). Elements to be arranged in the same reference area, they may be arranged in the same reference region as separate and independent elements. As described above, in carrying out the present invention, it is not always necessary to arrange only one operation element in one reference area. If a plurality of the same attribute elements are required, the same reference area is included. A plurality of different operating elements may be arranged.

  In this way, if a circuit as illustrated in FIG. 18 or 19 is employed as the driving circuit incorporated in the detection circuit 510, and a circuit as illustrated in FIG. 15 or 16 is employed as the detection circuit, The weight body 150 can be vibrated in the arbitrary coordinate axis direction of the xyz three-dimensional coordinate system, and the Coriolis force in the arbitrary coordinate axis direction of the xyz three-dimensional coordinate system acting on the weight body 150 can be detected.

  For example, if the detection circuit detects a Coriolis force fy in the y-axis direction acting on the weight body 150 in a state where the vibration body Ux in the x-axis direction is applied to the weight body 150 by the driving circuit, the detection is performed. The value can be output as a detected value of the angular velocity ωz about the z-axis acting on the apparatus housing. When a single-axis detection type angular velocity sensor having a function of detecting only the angular velocity ωz around the z-axis is configured by such a method, the drive circuit is provided with x for applying the vibration Ux in the x-axis direction. It is only necessary to provide an axis excitation function and to provide a detection circuit with a y-axis detection function for detecting the Coriolis force fy in the y-axis direction.

  Of course, as a method of detecting the angular velocity ωz around the z-axis, a method of detecting the Coriolis force fx in the x-axis direction acting on the weight body 150 in a state where the vibration Uy in the y-axis direction is applied can be adopted. When a single-axis detection type angular velocity sensor having a function of detecting only the angular velocity ωz around the z-axis is configured by such a method, a vibration Uy in the y-axis direction is applied to the driving circuit. It is sufficient to provide a y-axis excitation function for detecting the x-axis, and to provide an x-axis detection function for detecting the Coriolis force fx in the x-axis direction.

  After all, in order to construct a single axis detection type angular velocity sensor having a function of detecting only an angular velocity around a specific one axis in the xyz three-dimensional coordinate system, any one of the following six detection methods can be adopted. Good.

(1) The vibration body Ux in the x-axis direction is applied to the weight body by the x-axis excitation function, the Coriolis force fy acting in the y-axis direction is obtained by the y-axis detection function, and the angular velocity ωz around the z-axis is detected.
(2) The vibration Ux in the x-axis direction is applied to the weight body by the x-axis excitation function, the Coriolis force fz acting in the z-axis direction is obtained by the z-axis detection function, and the angular velocity ωy around the y-axis is detected.
(3) The y-axis vibration function Uy is applied to the weight body by the y-axis excitation function, the Coriolis force fx acting in the x-axis direction is obtained by the x-axis detection function, and the angular velocity ωz around the z-axis is detected.
(4) The y-axis vibration function Uy is applied to the weight body by the y-axis excitation function, the Coriolis force fz acting in the z-axis direction is obtained by the z-axis detection function, and the angular velocity ωx around the x-axis is detected.
(5) The z-axis excitation function gives the weight Uz in the z-axis direction, the x-axis detection function obtains the Coriolis force fx acting in the x-axis direction, and detects the angular velocity ωy around the y-axis.
(6) The z-axis excitation function applies a vibration Uz in the z-axis direction to the weight body, the y-axis detection function obtains the Coriolis force fy acting in the y-axis direction, and detects the angular velocity ωx around the x-axis.

  In the case of configuring such a single-axis detection type angular velocity sensor, any one of the above-described x-axis excitation function, y-axis excitation function, and z-axis excitation function required for the detection operation is prepared. Of the x-axis detection function, the y-axis detection function, and the z-axis detection function, it is sufficient to prepare any one detection function necessary for the detection operation.

  In order to construct a two-axis detection type angular velocity sensor having a function of detecting angular velocities around two specific axes in the xyz three-dimensional coordinate system, one of the following three detection methods may be employed. .

(1) The Coriolis force fy acting in the y-axis direction is obtained by the y-axis detection function in the state where the x-axis vibration Ux is applied to the weight body by the x-axis excitation function, and the angular velocity ωz around the z-axis is detected. At the same time, the Coriolis force fz acting in the z-axis direction is obtained by the z-axis detection function, and the angular velocity ωy around the y-axis is detected.
(2) The Coriolis force fx acting in the x-axis direction is obtained by the x-axis detection function while the y-axis excitation function is applied to the weight body in the y-axis direction, and the angular velocity ωz around the z-axis is detected. At the same time, the Coriolis force fz acting in the z-axis direction is obtained by the z-axis detection function, and the angular velocity ωx around the x-axis is detected.
(3) The Coriolis force fy acting in the y-axis direction is obtained by the y-axis detection function while the z-axis excitation function is applied to the weight body in the z-axis direction, and the angular velocity ωx around the x-axis is detected. At the same time, the Coriolis force fx acting in the x-axis direction is obtained by the x-axis detection function, and the angular velocity ωy around the y-axis is detected.

  On the other hand, a three-axis detection type angular velocity sensor having a function of detecting angular velocities around all three coordinate axes in the xyz three-dimensional coordinate system includes the above-described one-axis detection type angular velocity sensor and two-axis detection type angular velocity sensor. It can comprise by combining. However, since two types of vibration axes are required, it is necessary to perform a time division detection operation and switch the vibration direction between the first detection period and the second detection period.

  For example, in the first detection period, the detection method “(2) in the above-described single-axis detection type angular velocity sensor“ the vibration Ux in the x-axis direction is applied to the weight body by the x-axis excitation function and z is detected by the z-axis detection function ”. The Coriolis force fz acting in the axial direction is obtained and the angular velocity ωy about the y-axis is detected ”, and in the second detection period, the detection method“ y ” In a state where the vibration body Uy is applied to the weight body by the shaft excitation function, the Coriolis force fx acting in the x-axis direction is obtained by the x-axis detection function, and the angular velocity ωz around the z-axis is detected, and the z-axis If the Coriolis force fz acting in the z-axis direction is obtained by the detection function and the angular velocity ωx around the x-axis is detected, the vibration is caused in the x-axis direction in the first detection period and y in the second detection period. To vibrate in the axial direction It is necessary to switch Urn Do vibration direction, but the angular velocity ωx about the three axes, .omega.y, it is possible to configure the angular velocity sensor 3 axis detection type capable of detecting all .omega.z. Of course, the combination of detection methods is not limited to the above example.

  Eventually, even when a two-axis detection type angular velocity sensor or a two-axis detection type angular velocity sensor is configured, one of the above-described x-axis excitation function, y-axis excitation function, and z-axis excitation function is required. A plurality of excitation functions may be prepared, and one or a plurality of detection functions necessary for the detection operation may be prepared among the above-described x-axis detection function, y-axis detection function, and z-axis detection function.

<<< §6. Angular velocity detector >>>
In §5, an embodiment of an inertial sensor (angular velocity sensor) capable of detecting an angular velocity using a piezoelectric element has been described. Here, a plurality of n inertia sensors having such an angular velocity detection function are provided and combined. An embodiment that enables more accurate angular velocity detection by configuring the apparatus will be described. In the present application, for convenience of explanation, the single detection device described in §5 will be referred to as “inertia sensor” or “angular velocity sensor” as before, and the composite device described in §6 will be referred to as “angular velocity detection device”. To. The “angular velocity detection device” described here includes a plurality of n sets of “inertia sensors” (“angular velocity sensors”) described in §5 (here, an example in which n = 2 is set and an example in which n = 4 is set) It will be a composite device constructed by combining only those described.

  In the description so far, the operation of the inertial sensor has been described based on the xyz three-dimensional coordinate system having the coordinate axes indicated by the lowercase letters x, y, and z. Here, the uppercase letters X, Y, and Z are used. The operation of the angular velocity detection device will be described based on an XYZ three-dimensional coordinate system having the coordinate axes shown. The xyz three-dimensional coordinate system is a local coordinate system defined for each inertial sensor, whereas the XYZ three-dimensional coordinate system is a global coordinate system defined in a space where a plurality of sets of these inertial sensors are arranged. It will be. Note that each of the n sets of inertial sensors has an x-axis, a y-axis, and a z-axis that are parallel to the X-axis, the Y-axis, and the Z-axis in the XYZ three-dimensional coordinate system defined for the angular velocity detection device. Placed in.

  The angular velocity detection device described here has a function of detecting an angular velocity acting around a predetermined coordinate axis in the XYZ three-dimensional coordinate system. For this reason, this angular velocity detection apparatus is based on the angular velocities ωx, ωy, ωz around the predetermined axes detected by the detection circuits 510 of the n sets of inertial sensors, respectively, and the angular velocities acting around the predetermined coordinate axes in the XYZ three-dimensional coordinate system. An angular velocity output unit that outputs detection values of ωX, ωY, and ωZ is further provided.

  The angular velocity detection device described in §6 is not necessarily configured using the angular velocity sensor described in §5, and can be configured using any conventionally known angular velocity sensor. However, here, this angular velocity detection device will be described based on an embodiment in which two or four angular velocity sensors described in §5 are used.

<6-1. Embodiment using two sets of inertial sensors>
FIG. 20 is a plan view showing a portion of the basic structure of the angular velocity detection device 1000 configured by providing two sets of inertial sensors shown in FIG. The hatching in the figure is given to clearly show the shape of the basic structure, and does not show a cross section.

  In this angular velocity detection device 1000, a first inertial sensor A and a second inertial sensor B are arranged adjacent to each other along the X axis. FIG. 20 shows the basics of the first inertial sensor A. The structure 100A and the basic structure 100B of the second inertial sensor B are juxtaposed on the left and right, and a state where a part thereof is fused is shown.

  The basic structures 100A and 100B are both the same structure as the basic structure 100 shown in FIG. 2 (where 100B is a mirror image structure). That is, the basic structure 100A includes a fixed portion plate member 110A, a first plate bridge portion 120A, a second plate bridge portion 130A, a weight connection portion 140A, and a weight body 150A. The structural body 100B includes a plate member 110B for a fixing portion, a first plate-like bridge portion 120B, a second plate-like bridge portion 130B, a weight connection portion 140B, and a weight body 150B. The right end of the fixed portion plate member 110A and the left end of the fixed portion plate member 110B are joined as shown in the figure, and the basic structures 100A and 100B form an integral structure.

  As shown in the figure, the basic structures 100A and 100B are arranged so as to be symmetric with respect to the symmetry plane S (a plane perpendicular to the paper), and the shapes of the two are mirror images. Reference regions R1 to R12 as shown in FIG. 4 are defined in the basic structures 100A and 100B. The reference regions R1 to R12 include, for example, piezoelectric elements 601 to 601 as shown in FIG. 612 is formed.

  21 shows an XYZ three-dimensional coordinate system (global coordinate system) defined for the basic structure shown in FIG. 20 and an xyz three-dimensional coordinate system (local coordinate system) defined for individual inertial sensors A and B. It is a top view which shows a relationship. Here, as shown in the figure, the origin Q is taken at the center position of the basic structure of the angular velocity detecting device 1000, the X axis is in the right direction in the figure, the Y axis is in the upward direction in the figure, and the Z axis is in the vertical direction in the drawing. To define an XYZ three-dimensional coordinate system (to distinguish it from the origin O of the xyz three-dimensional coordinate system, the origin is set to Q in the XYZ three-dimensional coordinate system).

  The X axis is defined on a line connecting the origin O of the xyz three-dimensional coordinate system defined on the basic structure 100A and the origin O of the xyz three-dimensional coordinate system defined on the basic structure 100B. As described above, the x-axis, y-axis, and z-axis of the xyz three-dimensional coordinate system defined on the basic structure 100A, and the x-axis, y-axis of the xyz three-dimensional coordinate system defined on the basic structure 100B, The z-axis is parallel to the X-axis, Y-axis, and Z-axis in the XYZ three-dimensional coordinate system (only the x-axis direction of the xyz three-dimensional coordinate system defined on the basic structure 100B is the X-axis Is the opposite direction).

  A detection circuit 510A shown in the lower part of FIG. 21 is a detection circuit provided in the first inertial sensor A, and a detection circuit 510B is a detection circuit provided in the second inertial sensor B. The detection circuit 510A has an excitation function for vibrating the weight body 150A in a desired coordinate axis (x-axis, y-axis, or z-axis) direction and a predetermined coordinate axis (x-axis, y-axis, or and a detection function for detecting the Coriolis force in the z-axis direction, and detects an angular velocity (ωx, ωy or ωz) around a predetermined coordinate axis. Similarly, the detection circuit 510B includes an excitation function for vibrating the weight body 150B in a desired coordinate axis (x axis, y axis, or z axis) direction and a predetermined coordinate axis (x axis, y acting on the weight body 150B). And a detection function for detecting the Coriolis force in the direction of the axis or the z-axis) and detecting an angular velocity (ωx, ωy or ωz) around a predetermined coordinate axis.

  The angular velocity output unit 550 is based on the angular velocities (ωx, ωy, or ωz) around the predetermined axes detected by the detection circuits 510A and 510B, respectively, and the angular velocities ωX, ωY or the like acting around the predetermined coordinate axes in the XYZ three-dimensional coordinate system. Processing to output the detected value of ωZ is performed.

  The simplest operation mode of the angular velocity detection device 1000 shown in FIG. 21 is a single-axis detection type angular velocity detection in which the vibration axes of the two sets of weights 150A and 150B are made common and the angular velocity around a specific one axis is detected. This is a mode of operating as a device. FIG. 22 is a plan view showing an example of such a vibration mode. In the figure, points Ga and Gb are the gravity center points of the weight bodies 150A and 150B, respectively, and the weight bodies 150A and 150B both vibrate using the X axis as a common vibration axis.

  In the illustrated example, vibration UX (+) in the X-axis direction is applied to the weight body 150A, and vibration UX (−) in the X-axis direction is applied to the weight body 150B. Here, the reason that one vibration is UX (+) and the other vibration is UX (−) is to indicate that both vibrations are vibrations of opposite phases while having the same period. . That is, during the period in which the weight body 150A moves to the left in the figure, the weight body 150B moves to the right in the figure, and conversely, the period in which the weight body 150A moves to the right in the figure. In the middle, the weight body 150B moves to the left in the figure.

  Note that the vibration about the X axis in the XYZ global coordinate system is a vibration in the reverse direction, such as vibration UX (+), UX (-), but the local coordinate system in each of the inertial sensors A and B As the vibration about the x-axis, as shown in FIG. 21, the directions of the x-axis are different between the right and left inertial sensors, so that the weight bodies 150A and 150B of the two sets of inertial sensors A and B have the same phase. Vibration Ux is given.

  In this way, the drive so that the moving directions of the two sets of weight bodies 150A and 150B are reversed is a consideration for reducing vibration leakage to the apparatus housing. In the structure shown in FIG. 20, since the fixed plate members 110A and 110B are fixed to the apparatus casing, the vibrations of the two sets of weights 150A and 150B are also transmitted to the apparatus casing. It will be. Although not shown here, the device housing of the inertial sensor A and the device housing of the inertial sensor B are merged to accommodate the entire basic structure shown in FIG. 20 as the device housing of the angular velocity detecting device 1000. An apparatus housing is prepared.

  In this way, if vibration of the weight body is transmitted to the device housing and leaks to the outside, the vibration mode of the weight body is affected by the external environment at the time of use, and the detection result is adversely affected. It will reach. For example, if you touch the device case where vibration leakage occurs, the change in the vibration mode of the device case will affect the vibration mode of the weight body, the detection system will be affected by disturbance, and the correct detection value will be displayed. You can't get it. Therefore, it is preferable to reduce vibration leakage to the outside as much as possible.

  As shown in FIG. 22, if the two sets of weight bodies 150A and 150B are vibrated in opposite phases while using the X axis as a common vibration axis, the vibration component in the X axis direction leaking to the outside is entirely present. Therefore, vibration leakage can be reduced. As shown in FIG. 20, in the angular velocity detection device shown here, the structure of the basic structure is bilaterally symmetric with respect to the symmetry plane S, so the vibration component in the X-axis direction that leaks to the outside is more effectively canceled out. It will be.

  As shown in FIG. 22, the Coriolis force fy in the y-axis direction in the local coordinate system acting on the weights 150A and 150B is detected in the state where the two sets of weights 150A and 150B are vibrated in the X-axis direction. For example, the inertial sensor A can obtain the angular velocity ωza around the z axis, and the inertial sensor B can obtain the angular velocity ωzb around the z axis. The local z axis of the inertial sensor A and the local z axis of the inertial sensor B are offset from the global Z axis, but both are parallel to each other. Therefore, in the angular velocity detection based on the Coriolis law, theoretically, ωza = ωzb = ωZ.

  Since the detection value ωza is obtained from the detection circuit 510A and the detection value ωzb is obtained from the detection circuit 510B, the angular velocity output unit 550 shown in FIG. 21 outputs either one as the angular velocity ωZ around the Z axis on the global coordinate system. Alternatively, the average value ωZ obtained by the equation ωZ = (ωza + ωzb) / 2 may be output as the angular velocity around the Z axis on the global coordinate system. By outputting the average value, it is possible to output a more accurate detection value in which variations due to measurement errors for individual sensors are corrected.

  On the other hand, as shown in FIG. 22, in a state where the two weight bodies 150A and 150B are vibrated in the X-axis direction, the Coriolis force fz in the z-axis direction in the local coordinate system acting on the weight bodies 150A and 150B is obtained. If detected, the angular velocities ωya and ωyb around the y-axis can be obtained from the inertial sensors A and B, so the angular velocities ωY around the Y-axis on the global coordinate system can be output. Of course, it is also possible to detect the angular velocity around the predetermined axis by vibrating the two sets of weight bodies 150A and 150B in the Y-axis direction or in the Z-axis direction.

  After all, if the angular velocity detection device 1000 shown in FIG. 21 is operated as a single-axis detection type angular velocity detection device, the first coordinate axis in the XYZ three-dimensional coordinate system is set as a common vibration axis, and the second coordinate axis is set. A common Coriolis force detection axis is set, a third coordinate axis is set as a common angular velocity detection axis, and each inertial sensor A, B is in a state where each weight body is vibrated in a common vibration axis direction. The Coriolis force acting in the direction of the Coriolis force detection axis is obtained, the angular velocities acting around the axis parallel to the common angular velocity detection axis are respectively detected, and the angular velocity output unit 550 detects the angular velocity detected by each of the inertial sensors A and B. Either one or both average values may be output as the detected value of the angular velocity acting around the common angular velocity detection axis.

  Further, as shown in FIG. 22, while the weight bodies 150A and 150B are vibrated using the X axis as a common vibration axis, the Coriolis force fy in the y-axis direction in the local coordinate system in each of the inertial sensors A and B, If both the Coriolis force fz in the z-axis direction in the local coordinate system is detected, in each of the inertial sensors A and B, angular velocities ωza and ωzb around the z-axis in the local coordinate system and angular velocities around the y-axis in the local coordinate system. ωya and ωyb can be detected. Therefore, this apparatus can be operated as a two-axis detection type angular velocity detection apparatus.

  Also in this case, since the z-axis and y-axis in the local coordinate system are different axes between the two inertial sensors A and B, the angular velocity detection values ωza and ωya output from the detection circuit 510A and the detection circuit 510B output them. The detected angular velocity values ωzb and ωyb are detected values around different axes. However, since the z-axis and y-axis in the local coordinate system of the two inertial sensors A and B are axes parallel to the Z-axis and Y-axis in the global coordinate system, theoretically, ωza = ωzb = ωZ, ωya = ωyb = ωY. Accordingly, either ωza or ωzb may be output as the angular velocity ωZ around the Z axis in the global coordinate system, and one of ωya or ωyb may be output as the angular velocity ωY around the Y axis in the global coordinate system. Of course, in order to output a more accurate detection value, the average value of the detection values ωza and ωzb is output as the angular velocity ωZ around the Z axis in the global coordinate system, and the average value of the detection values ωya and ωyb is output in the global coordinate system Y You may output as angular velocity (omega) Y around an axis | shaft.

  After all, if the angular velocity detection device 1000 shown in FIG. 21 is operated as a two-axis detection type angular velocity detection device, the first coordinate axis in the XYZ three-dimensional coordinate system is defined as a common vibration axis, and each inertial sensor A, B obtains the angular velocity acting around the local axis parallel to the third coordinate axis by obtaining the Coriolis force acting in the second coordinate axis direction in a state where each weight body vibrates in the common vibration axis direction. The angular velocity acting around the local axis parallel to the second coordinate axis is detected by detecting the Coriolis force acting in the third coordinate axis direction, and the angular velocity output unit 550 detects each inertial sensor. Among the angular velocities, the average value of one or both of the angular velocities acting around the local axis parallel to the third coordinate axis is calculated around the third coordinate axis. Output as the detected value of the acting angular velocity, and output the average value of one or both of the angular velocities acting around the local axis parallel to the second coordinate axis as the detected value of the angular velocity acting around the second coordinate axis do it.

  On the other hand, in order to operate the angular velocity detection device 1000 shown in FIG. 21 as a three-axis detection type angular velocity detection device, as described above, each of the inertial sensors A and B performs a time-division detection operation. Although it is possible to adopt a method of switching the vibration direction between the first detection period and the second detection period, in practice, the advantage of incorporating two sets of inertial sensors A and B is 2 It is preferable to adopt a method in which the vibration direction of the weight body in the pair of inertial sensors A and B is made different. In general, when an operation for switching the vibration direction of the same weight body is performed, a predetermined time is required until the vibration of the weight body is stabilized, and a detection value is obtained during a period when the vibration is unstable. This is because there is a harmful effect of disappearing.

  FIG. 23 is a plan view showing an example of a vibration mode of the weight body of each of the inertial sensors A and B in the three-axis detection type angular velocity detection device adopting such a method. In the illustrated example, a vibration UY in the Y-axis direction is applied to the weight body 150A, and a vibration UX in the X-axis direction is applied to the weight body 150B. Therefore, the left inertial sensor A can detect the angular velocity ωxa around the x axis and the angular velocity ωza around the z axis in the local coordinate system, and the right inertial sensor B can detect the angular velocity ωyb around the y axis in the local coordinate system. (And angular velocity ωzb around the z-axis) can be detected.

  Therefore, for example, the angular velocity output unit 550 outputs the angular velocity ωxa around the x axis detected by the inertial sensor A as the angular velocity ωX around the X axis in the global coordinate system, and the angular velocity ωza around the z axis detected by the inertial sensor A is obtained. If the angular velocity ωZ around the Y axis in the global coordinate system is output as the angular velocity ωZ around the Y axis in the global coordinate system, the angular velocity ωZ around the Z axis in the global coordinate system is output as the angular velocity ωY around the Y axis. , ΩZ can be obtained.

  In the case of the example shown in FIG. 21, since the direction of the x-axis of the inertial sensor B is reversed with respect to the direction of the X-axis of the global coordinate system, the local detection value obtained by involving the x-axis. When converting to a global detection value, a correction process such as reversing the sign is required.

  Eventually, if the angular velocity detection device 1000 shown in FIG. 21 is operated as a three-axis detection type angular velocity detection device by the above-described method, the first inertial sensor A has the first coordinate axis in the XYZ three-dimensional coordinate system. Is defined as the vibration axis, both the second coordinate axis and the third coordinate axis are Coriolis force detection axes. For the second inertial sensor B, the second coordinate axis in the XYZ three-dimensional coordinate system is the vibration axis, Each of the inertial sensors A and B determines the Coriolis force acting in the direction of each Coriolis force detection axis in a state where each of the inertial sensors A and B vibrates in the direction of each vibration axis. The angular velocity acting around the local axis parallel to each angular velocity detection axis is detected, and the angular velocity output unit detects the second coordinate axis based on the angular velocity detected by the first inertial sensor A. If the angular velocity acting on the third coordinate axis and the detected value of the angular velocity acting around the third coordinate axis are output, and the detected value of the angular velocity acting around the first coordinate axis is output based on the angular velocity detected by the second inertial sensor. Good.

<6-2. Embodiment using four sets of inertial sensors>
FIG. 24 is a plan view showing a portion of the basic structure of the angular velocity detection device 2000 configured by providing four sets of inertial sensors shown in FIG. The hatching in the figure is given to clearly show the shape of the basic structure, and does not show a cross section.

  In this angular velocity detection device 2000, inertial sensor A, inertial sensor B, inertial sensor C, and inertial sensor D are arranged in a matrix of 2 rows and 2 columns. 24 shows a state where the basic structure 100A of the inertial sensor A and the basic structure 100B of the inertial sensor B are juxtaposed on the left and right, and the basic structure of the inertial sensor C is shown in the lower part of FIG. A state in which the body 100C and the basic structure 100D of the inertial sensor D are juxtaposed on the left and right is shown. A part of these four sets of inertial sensors A to D are fused via the symmetry planes S1 and S2.

  The basic structures 100A to 100D are all the same structure as the basic structure 100 shown in FIG. 2 (a part of the structures are mirror images). In other words, the basic structure 100A includes a plate member 110AC for a fixing portion, a first plate-like bridge portion 120A, a second plate-like bridge portion 130A, a weight connection portion 140A, and a weight body 150A. The structural body 100B includes a plate member 110BD for a fixing portion, a first plate-like bridge portion 120B, a second plate-like bridge portion 130B, a weight connection portion 140B, and a weight body 150B.

  The basic structure 100C includes a fixed portion plate member 110AC, a first plate bridge portion 120C, a second plate bridge portion 130C, a weight connection portion 140C, and a weight body 150C. The structure 100D includes a fixed portion plate member 110BD, a first plate bridge portion 120D, a second plate bridge portion 130D, a weight connection portion 140D, and a weight body 150D.

  Here, the fixing portion plate member 110AC is a fixing portion plate member that is commonly used in the basic structures 100A and 100C, and the fixing portion plate member 110BD is the basic structures 100B and 100D. It is the plate-shaped member for fixing | fixed part utilized in common. The right end of the fixed portion plate member 110AC and the left end of the fixed portion plate member 110BD are joined as illustrated, and the four sets of basic structures 100A, 100B, 100C, and 100D are fused together. It is an integral structure.

  As shown in the figure, the basic structures 100A and 100B are arranged so as to be symmetric with respect to the symmetry plane S1 (plane perpendicular to the paper surface), and the shapes of the two are mirror images. Similarly, the basic structures 100C and 100D are arranged so as to be symmetric with respect to the symmetry plane S1 (a plane perpendicular to the paper), and the shapes of the two are mirror images. The basic structures 100A and 100C are arranged so as to be symmetric with respect to the symmetry plane S2 (a plane perpendicular to the paper), and the shapes of the two are mirror images. Similarly, the basic structures 100B and 100D are arranged so as to be symmetrical with respect to the symmetry plane S2 (plane perpendicular to the paper surface), and the shapes of both are in a mirror image relationship.

  As described above, the basic structure of the angular velocity detecting device 2000 is also symmetric with respect to the illustrated symmetry plane S1, and is also symmetric with respect to the illustrated symmetry plane S2. In each of the basic structures 100A to 100D, reference regions R1 to R12 as shown in FIG. 4 are defined. In each of the reference regions R1 to R12, for example, as shown in FIG. Piezoelectric elements 601 to 612 are formed.

  25 shows an XYZ three-dimensional coordinate system (global coordinate system) defined for the basic structure shown in FIG. 24 and an xyz three-dimensional coordinate system (local coordinate system) defined for individual inertial sensors AD. It is a top view which shows a relationship. Here, as shown in the drawing, the origin Q is taken at the center position of the basic structure of the angular velocity detecting device 2000, the X axis is in the right direction in the figure, the Y axis is in the upward direction in the figure, and the Z axis is in the vertical direction in the drawing. By taking the above, an XYZ three-dimensional coordinate system is defined. When such an XYZ three-dimensional coordinate system is defined, inertial sensor B is arranged in the first quadrant, inertial sensor A is arranged in the second quadrant, inertial sensor C is arranged in the third quadrant, and inertial sensor D is in the first quadrant. It is arranged in 4 quadrants.

  Since the basic structure of the angular velocity detection device 2000 has the above-described symmetrical structure, the x-axis, y-axis, and z-axis of the xyz three-dimensional coordinate system defined for the individual inertial sensors AD. The direction of the axis has symmetry with respect to the X axis and the Y axis. As described above, the x-axis, y-axis, and z-axis of the local coordinate system defined for each of the inertial sensors A to D are parallel to the X-axis, Y-axis, and Z-axis of the global coordinate system, respectively. .

  Detection circuits 510A to 510D shown in the lower part of FIG. 25 are detection circuits provided in the inertial sensors A to D, respectively, an excitation function for vibrating the weight bodies 150A to 150D, and the weight bodies 150A to 150D. And a detection function for detecting Coriolis force acting on the lens, and an angular velocity around a predetermined coordinate axis can be detected. The angular velocity output unit 560 is based on the angular velocities (ωx, ωy, or ωz) around the predetermined axes detected by the detection circuits 510A to 510D, respectively, and the angular velocities ωX, ωY or the like acting around the predetermined coordinate axes in the XYZ three-dimensional coordinate system. Processing to output the detected value of ωZ is performed.

  The simplest operation mode of the angular velocity detection device 2000 shown in FIG. 25 is a single axis detection type angular velocity detection in which the vibration axes of the four sets of weights 150A to 150D are made common and the angular velocity around a specific one axis is detected. This is a mode of operating as a device. FIG. 26 is a plan view showing an example of such a vibration mode. In the figure, points Ga to Gd are gravity center points of the weight bodies 150A to 150D, respectively, and the weight bodies 150A to 150D all vibrate with the X axis as a common vibration axis.

  In the illustrated example, vibrations UX (+) in the X-axis direction are applied to the weight bodies 150A and 150C, and vibrations UX (−) in the X-axis direction are applied to the weight bodies 150B and 150D. . As described above, the vibrations UX (+) and UX (−) are vibrations having opposite phases while having the same period. As described above, the effect of suppressing the vibration leakage to the apparatus housing can be obtained by performing the vibration in the opposite phase as described above. Although the illustration of the device housing is omitted, the device housings of the inertial sensors A to D are fused, and the device housing of the angular velocity detection device 2000 is a device that accommodates the entire basic structure shown in FIG. A housing is prepared.

  As shown in FIG. 26, in the state where the four weight bodies 150A to 150D are vibrated in the X-axis direction, the Coriolis force fy in the y-axis direction in the local coordinate system acting on the weight bodies 150A to 150D is detected. For example, the angular velocity ωza around the z axis from the inertial sensor A, the angular velocity ωzb around the z axis from the inertial sensor B, the angular velocity ωzc around the z axis from the inertial sensor C, the angular velocity ωzd around the z axis from the inertial sensor D, Can be obtained. 25, the detection value ωza is obtained from the detection circuit 510A, the detection value ωzb is obtained from the detection circuit 510B, the detection value ωzc is obtained from the detection circuit 510C, and the detection value ωzd is obtained from the detection circuit 510D. Therefore, any one of these may be output as an angular velocity ωZ around the Z axis on the global coordinate system, or an average value of some is output as ωZ in order to obtain a more accurate detection value. May be. For example, if four average values are used, the average value ωZ obtained by the equation ωZ = (ωza + ωzb + ωzc + ωzd) / 4 can be output as the angular velocity around the Z axis on the global coordinate system.

  As shown in FIG. 25, since the origins O of the xyz three-dimensional coordinate system defined for the inertial sensors A to D are shifted from each other, the positions of the z axes of the local coordinate systems are also shifted. Therefore, the angular velocity detection values ωza to ωzd output from the detection circuits 510A to 510D are detection values around the different coordinate axes z. As described above, theoretically, ωza = ωzb = ωzc = ωzd. Therefore, an average value for any one or some of these may be output as the angular velocity ωZ around the Z axis on the global coordinate system.

  On the other hand, as shown in FIG. 26, the Coriolis force fz in the z-axis direction in the local coordinate system acting on the weights 150A to 150D in a state where the four sets of weights 150A to 150D are vibrated in the X-axis direction. If detected, the angular velocities ωya to ωyd around the y axis can be obtained from the respective inertial sensors A to D, so the angular velocities ωY around the Y axis on the global coordinate system can also be output. Of course, it is also possible to detect the angular velocity around the predetermined axis by vibrating the four weight bodies 150A to 150D in the Y-axis direction or in the Z-axis direction.

  After all, as a general theory, if an angular velocity detection device incorporating a plurality of n sets of inertial sensors is operated as a single-axis detection type angular velocity detection device, the first coordinate axis in the XYZ three-dimensional coordinate system is set to a common vibration. The second coordinate axis is defined as a common Coriolis force detection axis, the third coordinate axis is defined as a common angular velocity detection axis, and each of the n sets of inertial sensors has their respective weights in a common vibration axis direction. The Coriolis force acting in the direction of the common Coriolis force detection axis is obtained, and the angular velocities acting around the local axis parallel to the common angular velocity detection axis are respectively detected. Any one or several average values of the angular velocities detected by the respective inertial sensors may be output as detected values of angular velocities acting around the common angular velocity detection axis.

  Further, as shown in FIG. 26, while the weight bodies 150A to 150D are vibrated with the X axis as a common vibration axis, the Coriolis force fy in the y axis direction in the local coordinate system in each of the inertial sensors A to D, If both the Coriolis force fz in the z-axis direction in the local coordinate system is detected, in each of the inertial sensors A to D, the angular velocities ωza to ωzd around the z-axis in the local coordinate system and the angular velocities around the y-axis in the local coordinate system ωya to ωyd can be detected. Therefore, this apparatus can be operated as a two-axis detection type angular velocity detection apparatus.

  In this case as well, the z-axis and y-axis in the local coordinate system are different from each other in the four sets of inertial sensors A to D. Therefore, the detection values ωza and ωya output from the detection circuit 510A and the detection circuit 510B are output. The detected values ωzb, ωyb, the detected values ωzc, ωyc output from the detecting circuit 510C, and the detected values ωzd, ωyd output from the detecting circuit 510D are detected values around different axes. However, since the z-axis and y-axis in the local coordinate system of the four sets of inertial sensors A to D are axes parallel to the Z-axis and Y-axis in the global coordinate system, either one of the detected values ωza to ωzd or Some average values are output as the angular velocity ωZ around the Z axis in the global coordinate system, and any one or some average value of the detected values ωya to ωyd is output as the angular velocity ωY around the Y axis in the global coordinate system. That's fine.

  After all, as a general rule, if an angular velocity detection device incorporating a plurality of n sets of inertial sensors is operated as a two-axis detection type angular velocity detection device, the first coordinate axis in the XYZ three-dimensional coordinate system is set to a common vibration. The n-axis inertial sensors are parallel to the third coordinate axis by determining the Coriolis force acting in the second coordinate axis direction when each of the n sets of inertial sensors vibrates the respective weight bodies in the common vibration axis direction. Angular velocity acting around the local axis, and detecting the angular velocity acting around the local axis parallel to the second coordinate axis by obtaining the Coriolis force acting in the direction of the third coordinate axis. Any one or some of the angular velocities acting around the local axis parallel to the third coordinate axis among the angular velocities detected by each of the n sets of inertial sensors The average value is output as the detected value of the angular velocity acting around the third coordinate axis, and any one or several average values of the angular velocities acting around the local axis parallel to the second coordinate axis are used as the second value. May be output as a detected value of angular velocity acting around the coordinate axis.

  On the other hand, in order to operate the angular velocity detection device 2000 shown in FIG. 25 as a three-axis detection type angular velocity detection device, as described above, each of the inertial sensors A to D performs a time-division detection operation. Although it is possible to adopt a method of switching the vibration direction between the first detection period and the second detection period, as described above, when the operation of switching the vibration direction is performed, the vibration of the weight body becomes unstable. Therefore, in practice, taking advantage of the fact that a plurality of inertial sensors A to D are incorporated, these inertial sensors are classified into a first group and a second group, and the vibration of the weight body for each group. It is preferable to adopt a method of changing the direction.

  FIG. 27 is a plan view showing an example of a vibration mode of the weight body of each of the inertial sensors A to D in the three-axis detection type angular velocity detection device adopting such a method. In the illustrated example, the inertial sensors B and C are classified into the first group and the inertial sensors A and D are classified into the second group, and the inertial sensors B and C belonging to the first group are weighted with the X axis as the vibration axis. Vibrations UX (+) and UX (−) are given to the body, and for the inertial sensors A and D belonging to the second group, the vibrations UY (+) and UY (−) are applied to the weight body with the Y axis as the vibration axis. Giving. As described above, the vibrations UX (+) and UX (−) are vibrations having opposite phases, and the vibrations UY (+) and UY (−) are also vibrations having opposite phases to each other. In addition, the vibration component in the Y-axis direction is canceled out as a whole, and an effect of suppressing vibration leakage to the apparatus housing is obtained.

  When such a vibration mode is adopted, in the inertial sensors B and C belonging to the first group, the weight bodies 150B and 150C vibrate in the x-axis direction in the local coordinate system, and thus the angular velocity around the y-axis in the local coordinate system. It is possible to detect ωyb, ωyc and angular velocities ωzb, ωzc around the z-axis. In addition, in the inertial sensors A and D belonging to the second group, the weight bodies 150A and 150D vibrate in the y-axis direction in the local coordinate system, so that the angular velocities ωxa and ωxd (and the z-axis around the x-axis in the local coordinate system). The surrounding angular velocities ωza, ωzd) can be detected.

  Therefore, for example, the angular velocity output unit 560 outputs one or the average value of the angular velocities ωxa and ωxd as the angular velocity ωX around the X axis of the global coordinate system, and the one or the average value of the angular velocities ωyb and ωyc is the global coordinate system. One of the angular velocities ωzb and ωzc or an average value thereof (when the angular velocities ωza and ωzd are detected, the average value of the four sets of angular velocities ωza, ωzb, ωzc, and ωzd) may be globally output. If the angular velocity ωZ around the Z axis of the coordinate system is output, angular velocities ωX, ωY, and ωZ around the three axes can be obtained.

  As described above, the x-axis, y-axis, and z-axis of each local coordinate system and the X-axis, Y-axis, and Z-axis of the global coordinate system are slightly displaced but are parallel to each other. Each angular velocity detected on the system theoretically matches the angular velocities ωX, ωY, ωZ on the global coordinate system.

  Note that, as shown in FIG. 25, the direction of specific coordinate axes in some local coordinate systems is reversed with respect to the direction of each coordinate axis in the global coordinate system. When converting the local detection value into the global detection value, a correction process such as reversing the sign is required.

  After all, in general, if an angular velocity detection device incorporating a plurality of n sets of inertial sensors is operated as a three-axis detection type angular velocity detection device, it belongs to the first group of each of n sets of inertial sensors. For the inertial sensor to be used, the first coordinate axis in the XYZ three-dimensional coordinate system is set as the vibration axis, the second coordinate axis and the third coordinate axis are both set as the Coriolis force detection axes, and the inertial sensors belonging to the second group are In the XYZ three-dimensional coordinate system, the second coordinate axis is set as the vibration axis, the third coordinate axis is set as the Coriolis force detection axis, and each of the n sets of inertial sensors vibrates the respective weight bodies in the respective vibration axis directions. In the state, Coriolis force acting in the direction of each Coriolis force detection axis is obtained, angular velocity acting around the local axis parallel to each angular velocity detection axis is detected, and angular velocity is detected. Based on the angular velocity detected by the inertial sensor belonging to the first group, the force unit outputs the detected angular velocity acting around the second coordinate axis and the angular velocity acting around the third coordinate axis, and belongs to the second group. The detected value of the angular velocity acting around the first coordinate axis may be output based on the angular velocity detected by the inertial sensor.

<6-3. Embodiment in which two sets of inertial sensors are used to tilt the vibration axis>
Here, the variation which performs the operation | movement which inclined the vibration axis about the angular velocity detection apparatus incorporating the two sets of inertial sensors described in §6-1 will be described. The angular velocity detection device used in this variation is basically the same as the angular velocity detection device 1000 shown in FIG. However, the processing operations of the detection circuits 510A and 510B and the angular velocity output unit 550 are slightly different. Hereinafter, this difference will be described.

  In section 6-1, the vibration mode shown in FIG. 23 is exemplified to describe an operation example of the three-axis detection type angular velocity detection device. In this example, the weight body 150A is given a vibration UY in the Y-axis direction, and the weight body 150B is given a vibration UX in the X-axis direction. In this way, the vibration directions are changed between the left and right inertial sensors A and B in order to detect the angular velocities ωX, ωY, and ωZ around the three axes without adopting the time division method. Because it is necessary to change.

  However, as shown in FIG. 23, when the left weight body 150A is vibrated in the vertical direction of the drawing and the right weight body 150B is vibrated in the horizontal direction of the drawing, the overall dynamic body balance is unbalanced. It must be said that the entire device must be an extremely unstable vibration system. For this reason, in the angular velocity detection apparatus adopting the vibration mode shown in FIG. 23, vibration leakage to the apparatus housing becomes noticeable, and the external environment during use may greatly affect the detection result.

  The embodiment described here proposes a unique vibration mode for solving such a problem. In order to explain this unique vibration mode, the X ′ axis and the Y ′ axis as shown in FIG. 28 are defined here. FIG. 28 is a plan view of the basic structure of the angular velocity detection device 1000 shown in FIG. 21, and has a structure in which the left basic structure 100A and the right basic structure 100B are fused as described above. Also in this figure, the origin Q is taken at the center position of the basic structure, and the X axis and the Y axis are defined in the illustrated direction. Therefore, the paper surface of the figure corresponds to the XY plane in this global coordinate system.

  Therefore, on this XY plane, the X ′ axis obtained by rotating the X axis 45 ° counterclockwise around the origin Q, and the Y obtained by rotating the Y axis 45 ° counterclockwise. The 'axis' is defined as shown. In the X ′ axis, the upper right direction in the figure is a positive direction, and the lower left direction is a negative direction. In the Y ′ axis, the upper left direction in the figure is a positive direction and the lower right direction is a negative direction. Next, as shown in FIG. 29, consider the vibration UX ′ along the X ′ axis and the vibration UY ′ along the Y ′ axis. In the case of the first inertial sensor A, the movement of reciprocating the center of gravity Ga in the diagonal direction is vibration UX ′ or vibration UY ′, and in the case of the second inertial sensor B, the gravity center Gb is inclined in the diagonal direction in the figure. The reciprocating motion becomes vibration UX ′ or vibration UY ′.

  As described above, the inertial sensors A and B have an x-axis excitation function for vibrating the weight body in the x-axis direction of the local coordinate system and a y-axis excitation function for vibrating in the y-axis direction. In the embodiments described so far, when the detection is performed by vibrating the weight body in the x-axis direction, the x-axis excitation function is used, and when the detection is performed by vibrating the weight body in the y-axis direction. Uses the y-axis excitation function, and it is assumed that these excitation functions are selectively used according to the mode of detection operation.

  However, since the x-axis excitation function and the y-axis excitation function are independent functions, both can be used simultaneously. For example, the drive circuit shown in FIG. 18 (a) is a circuit that plays the role of the x-axis excitation function, and the drive circuit shown in FIG. 18 (b) is a circuit that plays the role of the y-axis excitation function. It is a separate and independent circuit. Accordingly, if both of these driving circuits are operated simultaneously, the weight Ux and the vibration Uy in the y-axis direction can be simultaneously applied to the weight body. As a result, the weight body can be given a vibration UX ′ along the X ′ axis and a vibration UY ′ along the Y ′ axis.

  For example, let us consider a case where the driving circuit shown in FIG. 18 (a) and the driving circuit shown in FIG. 18 (b) are simultaneously operated for the inertial sensor A shown in FIG. At this time, the AC drive signals 641, 642, 643, and 644 have the same period, the AC drive signals 641 and 643 have the first phase, and the AC drive signals 642 and 644 have the second phase. (The first phase and the second phase are opposite to each other). Then, the weight body 150A moves in the y-axis positive direction when moving in the x-axis positive direction, and also moves in the y-axis negative direction when moving in the x-axis negative direction. As a result, the vibration body UX ′ along the X ′ axis is given to the weight body 150A.

  On the other hand, when the AC drive signals 641 and 644 are in the first phase and the AC drive signals 642 and 643 are in the second phase, the weight body 150A is moving in the positive x-axis direction. When moving in the negative direction of the y-axis and moving in the negative direction of the x-axis, it moves in the positive direction of the y-axis. It will be given.

  On the other hand, the inertial sensor B shown in FIG. 29 has a structure that is a mirror image with respect to the Y axis with respect to the inertial sensor A, and therefore performs an operation in which the relationship between the vibration UX ′ and the vibration UY ′ is reversed. In any case, if the phase of the AC drive signal to be supplied is appropriately set by combining the x-axis excitation function and the y-axis excitation function, the inertial sensors A and B both have the weight body along the X ′ axis. A driving operation that vibrates or vibrates along the Y ′ axis is possible.

  Therefore, let us operate this angular velocity detection apparatus 1000 in a vibration mode as shown in FIG. In other words, the weight body 150A of the inertial sensor A is given a vibration UY ′ (+) along the Y ′ axis, and the weight body 150B of the inertial sensor B is given a vibration UX ′ (+) along the X ′ axis. )give. Here, the vibration UY ′ (+) and the vibration UX ′ (+) are vibrations having the same period, and the symbol “(+)” indicates that the vibration axis moves in the positive direction of the vibration axis. Specifically, the vibration UY ′ (+) indicates a vibration mode that moves in the positive direction of the Y ′ axis in the first half cycle, and UX ′ (+) indicates a vibration mode that moves in the positive direction of the X ′ axis in the first half cycle. Show.

  Therefore, in the vibration mode shown in FIG. 30, while the gravity center point Ga is moving in the positive Y′-axis direction, the gravity center point Gb is moving in the positive X′-axis direction, and the gravity center point Ga is in the negative Y′-axis direction. While moving, the barycentric point Gb moves in the negative direction of the X ′ axis. When the movements of the two gravity center points Ga and Gb are synchronized in this way, the movements of the two gravity center points Ga and Gb are in opposite phases with respect to the X-axis direction. The components are canceled out as a whole, and vibration leakage can be reduced. As shown in FIG. 20, in the angular velocity detecting device 1000 shown here, the structure of the basic structure is symmetrical with respect to the symmetry plane S, so that the vibration component in the X-axis direction that leaks to the outside is more effectively canceled out. Will be.

  On the other hand, the same effect can be obtained in the vibration mode shown in FIG. In this case, a vibration body UX ′ (+) along the X′-axis is given to the weight body 150A of the inertial sensor A, and a vibration UY ′ along the Y′-axis is applied to the weight body 150B of the inertial sensor B. (+) Is given. Again, the vibration UX ′ (+) and the vibration UY ′ (+) are vibrations having the same period, and the symbol “(+)” indicates that the vibration axis moves in the positive direction of the first half period.

  Therefore, in the vibration mode shown in FIG. 31, while the gravity center point Ga is moving in the positive X′-axis direction, the gravity center point Gb is moving in the positive Y′-axis direction, and the gravity center point Ga is in the negative X′-axis direction. The center of gravity Gb moves in the negative direction of the Y ′ axis. If the movements of the two centroid points Ga and Gb are synchronized in this way, the movements of the two centroid points Ga and Gb are in opposite phases with respect to the X axis direction. The vibration component is totally canceled, and vibration leakage can be reduced.

  After all, the angular velocity detection device shown in FIGS. 30 and 31 has a structure in which two sets of inertial sensors A and B are arranged adjacent to each other along the X axis, and in one space with the YZ plane as a boundary surface. One inertial sensor A is arranged, and the other inertial sensor B is arranged in the other space, and both the inertial sensors A and B have a plane symmetrical structure with respect to the YZ plane. In the basic structure having such symmetry, the positive and negative reciprocations of the weight body in one inertial sensor in the positive and negative directions and the positive and negative Y ′ axes of the weight body in the other inertial sensor. Control is performed such that the reciprocating motion in the negative direction has the same period and the same phase. As a result, the vibration component in the X-axis direction that leaks to the outside is canceled out as a whole, and the effect of reducing the vibration leakage occurs.

  Comparing the vibration mode shown in FIG. 23 with the vibration mode shown in FIG. 30 or 31 while performing the detection operation using the angular velocity detection device 1000 having the same structure, in the latter case, the two gravity center points Ga , Gb movements are symmetrical on the left and right, and the overall dynamic balance is understood. Therefore, if the latter vibration mode is employed, the vibration system is more stable and vibration leakage to the apparatus housing is suppressed. Moreover, since the vibration mode shown in FIG. 30 or FIG. 31 satisfies the condition that the vibration directions of the two sets of inertial sensors A and B are different from each other (orthogonal to each other), like the vibration mode shown in FIG. The angular velocities ωX, ωY, and ωZ of all three axes can be obtained without performing time division processing.

  In short, in the embodiment described in §6-3, vibration leakage to the apparatus housing can be prevented by changing the vibration mode while using the angular velocity detection device 1000 used in the embodiment described in §6-1 as it is. The effect of suppressing will be obtained. As described above, each weight body actually vibrates along a vibration axis inclined at 45 ° such as the X ′ axis and the Y ′ axis, but the basic structure has an angle of 45 °. There is no need to arrange the members, and there is no problem in the manufacturing process.

  However, since the vibration axis is an axis inclined by 45 ° with respect to the X axis or the Y axis, it is necessary to perform a geometric conversion process when detecting the Coriolis force or outputting the angular velocity. For example, in FIG. 29, when the gravity center Ga of the weight body 150A vibrates along the Y ′ axis, the direction axis of the Coriolis force to be detected is not the X axis but the X ′ axis (an axis orthogonal to the vibration axis). )It turns out that. However, since the inertial sensor A does not have a function of directly detecting the Coriolis force fX ′ originally acting in the X′-axis direction, the force fx acting in the x-axis direction and the force fy acting in the y-axis direction are not provided. As the resultant force, it is necessary to perform an operation for calculating the Coriolis force fX ′ acting in the X′-axis direction.

  Specifically, since the direction of the X ′ axis is inclined by 45 ° with respect to the x and y axes, in the case of the inertial sensor A shown in FIG. 29, the Coriolis force fX ′ acting in the X ′ axis direction. Is a geometrical conversion formula “fX ′ = (1 / √2) · fx + (1 / √2) using detected values of the force fx acting in the x-axis direction and the force fy acting in the y-axis direction. It can be obtained by performing an operation based on “fy”. Similarly, the Coriolis force fY ′ acting in the Y′-axis direction is calculated based on the geometric conversion formula “fY ′ = − (1 / √2) · fx + (1 / √2) · fy”. It can ask for.

  In addition, the sign of each term on the right side in each of the above formulas varies depending on the orientation of the x-axis and y-axis on the local coordinate system with respect to the X-axis and Y-axis on the global coordinate system. That is, the above conversion equations are for the inertial sensor A shown in FIG. 29, but in the case of the inertial sensor B shown in FIG. 29, the direction of the x-axis is reversed, so that “fX ′ = − It is necessary to use conversion formulas of (1 / √2) · fx + (1 / √2) · fy ”and“ fY ′ = (1 / √2) · fx + (1 / √2) · fy ”.

  Of course, since the inertial sensors A and B have a function of directly detecting the Coriolis force fz acting in the z-axis direction, it is necessary to perform an operation using the above-described conversion formula for detecting fz. Absent. Therefore, for example, Coriolis in which the inertial sensor A shown in FIG. 31 acts on the weight body 150A in the Z-axis direction (the z-axis direction is the same) in a state where the weight body 150A is vibrated in the X′-axis direction. If the force fz is obtained, the angular velocity ωY ′ acting around the axis parallel to the Y ′ axis (around the axis passing through the center of gravity Ga and parallel to the Y ′ axis) can be detected. Similarly, the Coriolis force fz applied to the weight body 150B in the Z-axis direction (−z-axis direction) when the inertial sensor B shown in FIG. 31 vibrates the weight body 150B in the Y′-axis direction. , The angular velocity ωX ′ acting around the axis parallel to the X ′ axis (around the center of gravity Gb and parallel to the X ′ axis) can be detected.

  The angular velocity output unit 550 shown in FIG. 21 converts the angular velocity ωX ′ and the angular velocity ωY ′ thus given from the detection circuits 510A and 510B into the angular velocity ωX acting around the X axis and the angular velocity ωY acting around the Y axis, respectively. It has a function of performing conversion processing and outputting the angular velocity ωX and angular velocity ωY obtained by this conversion processing. This conversion process is performed using geometric conversion equations “ωX = (1 / √2) · ωX ′ − (1 / √2) · ωY ′” and “ωY = (1 / √2) · ωX ′ + (1 / √2) · ωY ′ ”.

  When outputting the angular velocity ωZ around the Z axis in addition to the angular velocities ωX and ωY from the angular velocity output unit 550, at least one of the inertial sensors A and B has the Y′-axis direction or X It suffices to provide a function for obtaining the Coriolis force acting in the axial direction.

  For example, if the inertial sensor A shown in FIG. 31 calculates the Coriolis force fY ′ acting on the weight 150A in the Y′-axis direction in a state where the weight 150A is vibrated in the X′-axis direction (described above). As described above, actually, the Coriolis force fY ′ is obtained by a geometric conversion formula based on the Coriolis forces fx and fy), and the Coriolis force fY ′ corresponds to the angular velocity ωza around the z-axis passing through the center of gravity Ga. .

  Alternatively, if the inertial sensor B shown in FIG. 31 obtains the Coriolis force fX ′ acting on the weight 150B in the X′-axis direction in a state where the weight 150B is vibrated in the Y′-axis direction (described above). As described above, actually, the Coriolis force fX ′ is obtained by a geometric conversion formula based on the Coriolis forces fx and fy), and the Coriolis force fX ′ corresponds to the angular velocity ωzb around the z axis passing through the center of gravity Gb. .

  Therefore, the angular velocity output unit 550 outputs the angular velocity ωza output from the detection circuit 510A, the angular velocity ωzb output from the detection circuit 510B, or an average value thereof as the angular velocity ωZ around the coordinate axis Z axis of the global coordinate system. For example, the angular velocities ωX, ωY, and ωZ of all three axes can be output.

  If it is sufficient to output the angular velocity ωX ′ around the X ′ axis and the angular velocity ωY ′ around the Y ′ axis instead of the angular velocity ωX around the X axis and the angular velocity ωY around the Y axis, the angular velocity ωX ′, A conversion process for converting ωY ′ to angular velocities ωX and ωY is unnecessary. The angular velocity output unit 550 only needs to output the angular velocities ωX ′, ωY ′, and ωZ as three-axis detection values. Since the X ′ axis, the Y ′ axis, and the Z axis are orthogonal to each other, it is practically hindered to output the angular velocities ωX ′, ωY ′, ωZ as detection values instead of the angular velocities ωX, ωY, ωZ. Does not occur.

<6-4. Embodiment in which four sets of inertial sensors are used to tilt the vibration axis>
Here, the variation which performs the operation | movement which inclined the vibration axis about the angular velocity detection apparatus incorporating the four sets of inertial sensors described in §6-2 will be described. The angular velocity detection device used in this variation is basically the same as the angular velocity detection device 2000 shown in FIG. However, the processing operations of the detection circuits 510A to 510D and the angular velocity output unit 560 are slightly different. Hereinafter, this difference will be described.

  In section 6-2, the vibration mode shown in FIG. 27 is exemplified to describe an operation example of the three-axis detection type angular velocity detection device. In this example, four inertial sensors A to D are divided into two groups, and for the inertial sensors B and C belonging to the first group, the weight body is vibrated in the X-axis direction and belongs to the second group. For the inertial sensors A and D, the weight body is vibrated in the Y-axis direction. At this time, vibrations UX (+) and UX (−) having opposite phases are applied to the inertial sensors B and C, and vibrations UY (+) and UY (−) having opposite phases to the inertial sensors A and D as well. Therefore, a device has been devised that cancels vibration components as a whole and suppresses vibration leakage to the apparatus housing.

  However, the vibrations UY (+), UX (+), UX (−), and UY (−) indicated by arrows in FIG. 27 are not generally balanced, and vibrations to the apparatus housing It is not always sufficient as a measure to suppress leakage. Similar to the embodiment described in §6-3, the embodiment described here proposes a unique vibration mode for solving the above problem by inclining the vibration axis at an angle of 45 °.

  Here, the X ′ axis and the Y ′ axis are defined as shown in FIG. FIG. 32 is a plan view of the basic structure of the angular velocity detection device 2000 shown in FIG. 25, and has a structure in which four sets of inertial sensors A to D are fused as described above. Also in this figure, the origin Q is taken at the center position of the basic structure, and the X axis and the Y axis are defined in the illustrated direction. Therefore, the paper surface of the figure corresponds to the XY plane in this global coordinate system.

  Therefore, on this XY plane, the X ′ axis obtained by rotating the X axis 45 ° counterclockwise around the origin Q, and the Y obtained by rotating the Y axis 45 ° counterclockwise. The 'axis' is defined as shown. In the X ′ axis, the upper right direction in the figure is a positive direction, and the lower left direction is a negative direction. In the Y ′ axis, the upper left direction in the figure is a positive direction and the lower right direction is a negative direction. Next, as shown in FIG. 33, consider the vibration UX ′ along the X ′ axis and the vibration UY ′ along the Y ′ axis for the weight bodies 150A to 150D of the inertial sensors A to D.

  Each inertial sensor A to D has an x-axis excitation function for vibrating the weight body in the x-axis direction of the local coordinate system and a y-axis excitation function for vibrating in the y-axis direction. As described in §6-3, it is possible to apply vibration UX ′ along the X ′ axis and vibration UY ′ along the Y ′ axis to each of the weight bodies 150A to 150D. .

  Therefore, let us operate this angular velocity detection device 2000 in a vibration mode as shown in FIG. In other words, the weight body 150A of the inertial sensor A is given a vibration UY ′ (+) along the Y ′ axis, and the weight body 150B of the inertial sensor B is given a vibration UX ′ (+) along the X ′ axis. ), A vibration body UX ′ (−) along the X ′ axis is applied to the weight body 150C of the inertial sensor C, and a vibration UY ′ along the Y ′ axis is applied to the weight body 150D of the inertial sensor D. (-) Is given.

  Here, the vibrations UX ′ (+), UY ′ (+), UX ′ (−), UY ′ (−) are all vibrations of the same period, and the symbol “(+)” indicates the vibration axis in the first half period. The symbol “(−)” indicates movement in the negative direction of the vibration axis in the first half cycle. Accordingly, when focusing on the movement of the gravity center points Ga to Gd of the four sets of weight bodies 150A to 150D, they move in the direction away from the origin Q (centrifugal movement) in the first half cycle, and all in the second half cycle. It moves in the direction approaching the origin Q (centripetal movement). As described above, the motion that repeats the centrifugal motion and the centripetal motion is a motion having symmetry about the origin Q, and is a motion that effectively cancels the vibration component in both the X-axis direction and the Y-axis direction. . For this reason, the vibration component leaking to the outside from the apparatus housing is canceled as a whole, and the vibration leakage can be effectively suppressed.

  In particular, the basic structure of the angular velocity detection device 2000 shown here has a shape that is symmetric with respect to both the X axis and the Y axis of the XY coordinate system. That is, when the four inertial sensors A to D are orthogonally projected onto the XY plane, the projected image of the inertial sensor A is the second quadrant, the projected image of the inertial sensor B is the first quadrant, and the projected image of the inertial sensor C is the third. The projection image of the quadrant and inertial sensor D is located in the fourth quadrant.

  Therefore, quoting the number of the quadrant in which each is arranged, inertial sensor B is the first inertial sensor, inertial sensor A is the second inertial sensor, inertial sensor C is the third inertial sensor, and inertial sensor D is When called the fourth inertial sensor, the first inertial sensor B and the second inertial sensor A have a plane-symmetric structure with the YZ plane as the symmetry plane, and the third inertial sensor C and the fourth inertial sensor are the same. The inertial sensor D has a plane-symmetric structure with a YZ plane as a plane of symmetry, and the first inertial sensor B and the fourth inertial sensor D have a plane-symmetric structure with a plane of symmetry as the XZ plane. The inertial sensor A and the third inertial sensor C have a plane-symmetric structure with the XZ plane as the plane of symmetry. Such a symmetric structure cancels out the vibration component that leaks out from the apparatus housing and plays a role of enhancing the effect of suppressing vibration leakage.

  Eventually, in the angular velocity detection device 2000 that performs the detection operation using the vibration mode shown in FIG. 34, the first inertia sensor B and the third inertia sensor C belong to the first group, and the second inertia sensor A and The fourth inertial sensor belongs to the second group, and for the inertial sensors B and C belonging to the first group, the weight body is moved in the X′-axis direction by combining the x-axis excitation function and the y-axis excitation function. For the inertial sensors A and D belonging to the second group, the weight body may be vibrated in the Y′-axis direction by combining the x-axis excitation function and the y-axis excitation function.

  At this time, the reciprocating motion of the weight body 150B in the first inertial sensor B in the positive and negative directions and the third inertial sensor C in the positive and negative directions of the weight body 150C in the positive and negative directions. Reciprocating motion of the weight body 150A in the second inertial sensor A in the positive and negative directions of the weight body 150A and the weight body 150D in the fourth inertial sensor D. Of the first inertial sensor B in the positive and negative directions, and the reciprocating motion of the weight 150B in the first inertial sensor B in the positive and negative directions, Control may be performed so that the reciprocating motion of the weight body 150A in the positive and negative directions of the weight body 150A in the second inertial sensor A has the same period and the same phase.

  On the other hand, FIG. 35 is a plan view showing another vibration mode of the angular velocity detection device 2000. In the case of this vibration mode, the weight body 150A of the inertial sensor A is given a vibration UX ′ (+) along the X ′ axis, and the weight body 150B of the inertial sensor B is along the Y ′ axis. Vibration UY ′ (+) is applied, weight UC ′ of inertial sensor C 150C is provided with vibration UY ′ (−) along the Y ′ axis, and weight body 150D of inertial sensor D is applied with X ′. A vibration UX ′ (−) along the axis is given.

  Here, the meanings of the respective symbols of the vibrations UX ′ (+), UY ′ (+), UX ′ (−), UY ′ (−) are as described above. Therefore, when focusing on the movement of the gravity center points Ga to Gd of the four weight bodies 150A to 150D, in the first half cycle, they move away from the X axis and move closer to the Y axis. Are both moved away from the Y axis and moved closer to the X axis. Such a movement is a movement having symmetry with respect to the X axis and the Y axis, and also a movement that effectively cancels the vibration component in both the X axis direction and the Y axis direction. For this reason, the vibration component leaking to the outside from the apparatus housing is canceled as a whole, and the vibration leakage can be effectively suppressed.

  After all, in the angular velocity detection device 2000 that performs the detection operation using the vibration mode shown in FIG. 35, the second inertia sensor A and the fourth inertia sensor D belong to the first group, and the first inertia sensor B and The third inertial sensor C belongs to the second group, and the inertial sensors A and D belonging to the first group are combined with the x-axis excitation function and the y-axis excitation function, so that the weight body is placed on the X′-axis. For the inertial sensors B and C belonging to the second group, the weight body may be vibrated in the Y′-axis direction by combining the x-axis excitation function and the y-axis excitation function.

  At this time, the reciprocating motion of the weight 150B in the first inertial sensor B in the positive and negative directions of the Y ′ axis and the positive and negative direction of the Y ′ axis of the weight 150C in the third inertial sensor C are performed. Of the second inertial sensor A in the positive and negative directions of the weight body 150A in the positive and negative directions and the weight body 150D in the fourth inertial sensor D. Of the first inertial sensor B in the positive and negative directions, and the reciprocating motion of the weight 150B in the first inertial sensor B in the positive and negative directions. The control may be performed so that the reciprocating motions of the weight body 150A in the inertial sensor A in the positive and negative directions of the weight body 150A have the same period and the same phase.

  In short, in the embodiment described in §6-4, vibration leakage to the apparatus housing can be prevented by changing the vibration mode while using the angular velocity detection device 2000 used in the embodiment described in §6-2 as it is. The effect of suppressing will be obtained. As described above, each weight body actually vibrates along a vibration axis inclined at 45 ° such as the X ′ axis and the Y ′ axis, but the basic structure has an angle of 45 °. There is no need to arrange the members, and there is no problem in the manufacturing process.

  In the case of the embodiment described here, the vibration axis is an axis inclined by 45 ° with respect to the X-axis and the Y-axis. Therefore, when Coriolis force is detected or angular velocity is output, geometric conversion processing is performed. Need to do. For example, in the case of the inertial sensor A shown in FIG. 33, the Coriolis force fX ′ acting in the X′-axis direction is a geometry using the detected values of the force fx acting in the x-axis direction and the force fy acting in the y-axis direction. It can be obtained by a general conversion formula. A specific conversion formula is as described in §6-3. Of course, since the Coriolis force fz acting in the z-axis direction has a function of directly detecting, it is not necessary to perform an operation using the above conversion equation.

  The angular velocity output unit 560 shown in FIG. 25 outputs angular velocities ωX ′, ωY ′, ωZ or angular velocities ωX, ωY, ωZ obtained by converting the angular velocities ωX ′, ωY ′, ωZ based on the angular velocities thus provided from the detection circuits 510A to 510D. Will do. A specific output method is as described in §6-3.

<6-5. Embodiment in which n sets of inertial sensors are used to tilt the vibration axis>
In §6-3, an embodiment in which two sets of inertial sensors are used to tilt the vibration axis is described, and in §6-4, an embodiment in which four sets of inertial sensors are used to tilt the vibration axis is described. Here, a general theory in which the embodiment in which the vibration axis is inclined in this way is extended to a plurality of n sets of inertial sensors will be briefly described.

  Here, the angular velocity detection device described as general theory includes, for example, a plurality of n sets of inertial sensors having an angular velocity detection function around a specific coordinate axis in the xyz three-dimensional coordinate system as described in §5, and an XYZ three-dimensional coordinate system. Is an angular velocity detection device for detecting an angular velocity acting around a predetermined coordinate axis. Here, in each of the n sets of inertial sensors, the x-axis, y-axis, and z-axis are parallel to the X-axis, Y-axis, and Z-axis in the XYZ three-dimensional coordinate system defined for the angular velocity detector. Are arranged as follows. The detection device outputs an angular velocity detection value acting around a predetermined coordinate axis in the XYZ three-dimensional coordinate system based on the angular velocity around the predetermined axis detected by the detection circuit of each of the n sets of inertial sensors. An output unit is further provided.

  When this device is operated as a two-axis detection type angular velocity detection device having a function of detecting angular velocities around two coordinate axes in an XYZ three-dimensional coordinate system, each weight sensor is provided with n sets of inertial sensors. Both an x-axis excitation function that vibrates in the x-axis direction and a y-axis excitation function that vibrates in the y-axis direction are provided. Then, the X ′ axis obtained by rotating the X axis 45 ° counterclockwise around the origin Q on the XY plane, and the Y axis rotated 45 ° counterclockwise around the origin Q on the XY plane. And the Y ′ axis obtained by making the inertial sensor belonging to the first group out of the n sets of inertial sensors a weight by combining the x-axis excitation function and the y-axis excitation function. When the body is vibrated in the X′-axis direction, the angular velocity ωY ′ acting around the local axis parallel to the Y′-axis is detected by obtaining the Coriolis force acting in the Z-axis direction on the weight body. , The inertial sensors belonging to the second group of each of the n sets of inertial sensors in a state where the weight body is vibrated in the Y′-axis direction by combining the x-axis excitation function and the y-axis excitation function. Z axis with respect to the weight By obtaining the Coriolis force acting on the direction, so as to detect the 'angular ωX exerted around parallel local axis to the axis' X. Then, the angular velocity output unit 560 can convert the angular velocity ωX ′ and the angular velocity ωY ′ into the angular velocity ωX acting around the X axis and the angular velocity ωY acting around the Y axis, respectively, as necessary. .

  Further, when this apparatus is operated as a three-axis detection type angular velocity detection apparatus having a function of detecting angular velocities around three coordinate axes in the XYZ three-dimensional coordinate system, an inertial sensor belonging to the first group, and An x-axis detection function for detecting a Coriolis force acting in the x-axis direction on at least one of the inertial sensors belonging to the second group and a y-axis detection function for detecting a Coriolis force acting in the y-axis direction By combining these x-axis detection function and y-axis detection function, the Coriolis force acting on the weight body in the Y'-axis direction or the X'-axis direction is obtained. It is sufficient to have a function of detecting the angular velocity ωZ acting around the Z axis. Then, the angular velocity output unit 560 can output three-axis components of angular velocities ωX, ωY, and ωZ.

<<< §7. Some variations >>>
Here, some modified examples of the various embodiments described so far will be described.

<7-1. Modified example in which the reference area for element placement is narrowed down to 8>
In the embodiment described so far, 12 sets of reference regions R1 to R12 are defined in the basic structure 100 as shown in FIG. 4, and at least one operation is performed in each of the 12 sets of reference regions R1 to R12. This is based on the premise that an element (detection element or drive element) is disposed.

  However, in practicing the present invention, it is not an essential requirement to arrange at least one operating element for all of these 12 sets of reference regions R1 to R12. As described above, among the 12 sets of reference regions R1 to R12, four sets of reference regions R2, R5, R8, and R11 arranged on the first longitudinal axis Ly or the second longitudinal axis Lx are included. When eight sets of reference regions R1, R3, R4, R6, R7, R9, R10, and R12 arranged on both sides of these are called the central arrangement region, in the present invention, at least 1 It is an essential requirement to arrange one operation element in eight sets of armpit arrangement areas, and it is not always necessary to arrange an operation element in four sets of central arrangement areas.

  As is apparent from FIGS. 5 to 7, the eight armpit arrangement regions are long even when the weight 150 is displaced in any of the x-axis, y-axis, and z-axis directions. Stretching stress is generated in the direction. On the other hand, with respect to the four central arrangement regions, stretching stress is generated in the longitudinal direction only when the weight body 150 is displaced in the z-axis direction. Therefore, when a detection method that does not require the displacement of the weight body 150 in the z-axis direction is adopted (for example, when detection of the acceleration αz is unnecessary, or when the weight body is vibrated in the x-axis direction, For example, when it is sufficient to detect the angular velocity ωz about the z-axis by detecting the Coriolis force fy), it is not necessary to arrange the operation elements in the four central arrangement regions.

  Of course, the displacement in the z-axis direction of the weight body 150 can be detected or caused by the elements arranged in the eight sets of armpit arrangement regions, so that the acceleration αz can be detected only by these elements. The Coriolis force fz can be detected and excited in the z-axis direction. In short, when the present invention is implemented with the minimum configuration, considering the expansion / contraction state of the eight sets of armpit arrangement regions shown in FIGS. What is necessary is just to take the structure arrange | positioned in the heel arrangement | positioning area | region.

<7-2. Fixed part made of an annular structure>
Here, as a modification of the basic structure 100 shown in FIG. 4, an example in which the fixing portion is configured by an annular structure will be described. FIG. 36 is a plan view showing the structure of a basic structure 700 according to this modification, and a side cross-sectional view (FIG. (B)) cut along the yz plane. FIG. 36 (a) is a plan view, but in order to clearly show the planar shape, hatched portions are shown inside the structure, and the positions of 12 sets of reference regions are indicated by rectangles.

  In the basic embodiment shown in FIG. 4, a fixing portion that extends along a longitudinal axis L <b> 0 parallel to the x-axis is used as a fixing portion that fixes one end of the first plate-like bridge portion 120 to the bottom plate 200 of the apparatus housing. The plate-like member 110 for use was used. On the other hand, in the modification shown in FIG. 36, the annular structure 710 is used as the fixing portion. As shown in the figure, this annular structure 710 is a rectangular frame-shaped structure having four sides, ie, a left side 711, a lower side 712, a right side 713, and an upper side 714. As shown in FIG. Is fixed to the upper surface of the bottom plate 800 of the apparatus casing.

  On the other hand, the root end portion of the first plate-like bridge portion 720 is connected to the vicinity of the lower end of the left side 711 of the annular structure 710 in FIG. The leading end of the first plate-like bridge portion 720 is connected to the root end portion of the second plate-like bridge portion 730 via the intermediate connection portion 725, and the second plate-like bridge portion 730 is connected. Is connected to the weight body 750 via the weight connection portion 740. After all, in the case of this modification, the fixed portion is constituted by the annular structure 710, and the first plate-like bridge portion 720 and the second plate-like bridge are formed in the inner region surrounded by the annular structure 710. The portion 730 and the weight body 750 are arranged.

  As described above, when the structure in which the annular structure 710 surrounds the first plate-shaped bridge portion 720, the second plate-shaped bridge portion 730, and the weight body 750 while maintaining a predetermined distance, the annular structure 710 serves as a stopper member that controls excessive displacement of the first plate-like bridge portion 720, the second plate-like bridge portion 730, and the weight body 750. That is, when an external force of a predetermined magnitude or more is applied to the apparatus housing, the member disposed in the inner region contacts the inner surface of the annular structure 710, so that the displacement of the member is controlled within a predetermined range. It is comprised so that. For this reason, even if excessive acceleration or Coriolis force is applied to the weight body 750 (force that damages each plate-like bridge portion 720, 730), excessive displacement of each portion can be limited. The situation where the bridge portions 720 and 730 are damaged can be avoided.

<7-3.の Addition of structure part>
Another feature of the modified example shown in FIG. 36 is that the intermediate connection portion 725 protrudes outward from the side surface of the front end portion of the first plate-like bridge portion 720 and the second plate-like bridge portion.庇 structure portion 802 projecting outward from the side surface of the root end portion of 730, and weight connection portion 740 projecting outward from the side surface of the distal end portion of second plate-like bridge portion 730 This is a point having a portion 803. Since these flange structures 801, 802, and 803 are provided, recesses are formed in the inner portion of the annular structure 710 at positions corresponding to these flange structures 801, 802, and 803.

  The inventor of the present application has found that the detection efficiency of the inertial sensor can be further improved by adopting a structure provided with the saddle structure portions 801, 802, and 803 as shown in the figure. This is because if the structure provided with the flange structures 801, 802, and 803 is employed, the stretching stress generated at the positions of the reference regions R1 to R12 can be further increased. Let's show this based on the simulation results of structural mechanics using a computer.

  FIG. 37 (a) shows a case where the weight body 150 has a displacement Δx in the positive x-axis direction (about xx-axis positive direction) with respect to the basic structure 100 (substantially corresponding to the basic structure 100 shown in FIG. It is a stress distribution diagram which shows the magnitude | size of the stress which arises in each plate-shaped bridge part 120,130 when producing | generating +). On the other hand, FIG. 37 (b) shows that the weight body 750 produces a displacement Δx (+) in the x-axis positive direction with respect to the basic structure 700 shown in FIG. 36 (the structure provided with the flange structures 801, 802, 803). It is a stress distribution diagram which shows the magnitude | size of the stress which arises in each plate-shaped bridge part at the time of. In each distribution diagram, when a certain amount of displacement occurs, the areas where moderate extension stress, strong extension stress, intermediate contraction stress, and strong contraction stress are applied are shown with their own hatching. (See legend at the top right of each figure).

  Similarly, FIG. 38 shows that the weight body of the basic structure (FIG. (A)) in which the heel structure portion is not formed and the basic structure (FIG. (B)) in which the heel structure portion is formed are y-axis positive. FIG. 39 is a stress distribution diagram showing the magnitude of the stress generated in each plate-like bridge portion when the direction displacement Δy (+) is generated, and FIG. 39 is a basic structure (FIG. (A )) And the magnitude of stress generated in each plate-like bridge when the weight body is displaced in the z-axis positive direction Δz (+) for the basic structure (Fig. FIG.

  Referring to the stress distribution diagrams of FIGS. 37 (a), 37 (b) and 38 (a), 38 (b), when the weight body is displaced in the x-axis direction or the y-axis direction, the left and right armpit arrangement regions It can be seen that a relatively large stretching stress is generated. On the other hand, referring to the stress distribution diagrams of FIGS. 39 (a) and 39 (b), it can be seen that when the weight body is displaced in the z-axis direction, a relatively large stretching stress is generated in all the reference regions. Therefore, it can be understood that the arrangement of the 12 sets of reference regions R1 to R12 shown in FIG. 4 is an ideal arrangement. The expansion and contraction states of the reference regions R1 to R12 shown in FIGS. 5 to 7 are obtained from the stress distribution diagrams of FIGS.

  Although not shown in the figure, stress distribution similar to that at both edges appears continuously on both side surfaces of each plate-like bridge portion 120, 130. Therefore, the armpit arrangement regions R1, R3, R4, R6, R7, R9, R10, and R12 can be provided not only on the upper surfaces of the plate-like bridge portions 120 and 130, but also on the side surfaces. The variations shown in FIGS. 17 (b) to 17 (d) take into account such side surface stress distribution.

  Moreover, in FIGS. 37 to 39, when the upper diagram (a) and the lower diagram (b) are compared, generally the stress distribution diagram shown in the lower diagram (b) generates a relatively large stretching stress. You can see that As shown in FIG. 36 (a), when a structure provided with eaves structure portions 801, 802, 803 is adopted, the root end portion and the tip end portion of the first plate-like bridge portion 720 and the second plate-like portion are used. This means that stress can be efficiently concentrated on the root end portion and the tip end portion of the bridge portion 730, and the detection efficiency of the inertial sensor can be further improved. Therefore, in practice, it is preferable to employ a structure provided with the ridge structure portions 801, 802, and 803 as shown in FIG.

  FIG. 40 is a plan view showing a basic structure of an angular velocity detecting device 3000 configured by providing four sets of inertial sensors having the basic structure 700 shown in FIG. 36 (hatching in the figure indicates the basic structure). It is given to clearly show the shape, not the cross section). The basic structures 700A to 700D shown in the figure correspond to the basic structure 700 shown in FIG. If the angular velocity detection device 3000 shown in FIG. 40 is used instead of the angular velocity detection device 2000 shown in FIG. 25, the detection efficiency can be further improved.

<7-4. Annular weight>
Finally, a modified example in which a weight body is provided on the outer side to form an annular structure will be described. In this modification, the roles of the fixed portion (annular structure 710) and the weight body (750) in the modification shown in FIG. 36 are reversed. That is, the annular structure 710 functioning as the fixing portion in the modification shown in FIG. 36 is caused to function as the weight body, and the plate-like body functioning as the weight body 750 is functioned as the fixing portion. Is. For this purpose, the lower surface of the plate-like body functioning as the weight body 750 in FIG. 36 is fixed to the upper surface of the bottom plate of the apparatus housing, and the annular structure 710 functioning as the fixing portion in FIG. In a state in which no action occurs, it may be suspended in a suspended state above the bottom plate of the apparatus housing.

  FIG. 41 is a plan view (FIG. 41 (a)) showing the structure of an inertial sensor basic structure 700E according to a modified example in which such a role is reversed, and a side sectional view of the structure cut along the yz plane (FIG. )) Comparing only the plan view shown as FIG. (A) in the upper stage, the basic structure 700 shown in FIG. 36 and the basic structure 700E shown in FIG. Comparing the cross-sectional side views shown as), you can understand the difference in structure between the two.

  In the case of the basic structure 700E shown in FIG. 41, a plate-like member 750E disposed at the center serves as a plate-like fixing portion, and a portion having a larger thickness than other portions. The lower surface of the plate-like fixing portion 750E is fixed to the upper surface of the bottom plate 800E of the apparatus housing. On the other hand, as shown in FIG. 41 (a), at the upper right corner of the plate-like fixing portion 750E, the root end portion (the upper end of the figure) of the first plate-like bridge portion 730E is provided via a fixed end connecting portion 740E. ) Is connected. In addition, a root end portion (right end in the drawing) of the second plate bridge portion 720E is connected to a tip portion (lower end in the drawing) of the first plate-like bridge portion 730E through an intermediate connection portion 725E. Further, an annular weight body 710E is connected to the tip end portion (left end in the figure) of the second plate-like bridge portion 720E.

  As shown in FIG. 41 (a), the annular weight body 710E is a rectangular frame-like structure having four sides of a left side 711E, a lower side 712E, a right side 713E, and an upper side 714E, as shown in FIG. 41 (b). Furthermore, it is suspended in the air so that it floats above the bottom plate 800E of the apparatus housing.

  In the embodiments described so far, the weight body is disposed at the inner position of the basic structure body. However, in the modification shown in FIG. 41, the annular weight body 710E is disposed at the outer position of the basic structure body 700E. Will be. If a structure in which the annular weight body is arranged on the outside in this way is generally easy to secure a large weight body weight, the weight body weight is increased to increase the detection efficiency. Above is advantageous.

  42 is a plan view (FIG. 42 (a)) showing a modified example in which the mass of the entire weight body is increased by adding auxiliary weight bodies 711F to 714F to the basic structure 700E shown in FIG. It is the sectional side view (FIG. (B)) which cut | disconnected by yz plane. As shown in the plan view of FIG. 42 (a), the structure when the basic structure 700F according to this modification is viewed from above is exactly the same as the structure of the basic structure 700E shown in FIG. Here, the same reference numerals as those of the basic structure 700E shown in FIG.

  In the embodiment shown in FIG. 42 as well, the central plate-like member 750E becomes a fixed portion fixed to the apparatus housing, and the surrounding annular structure 710E (rectangular frame composed of four sides 711E to 714E) overlaps. Functions as a weight. Here, the mass is increased by fixing the auxiliary weight body to the lower surface of the annular structure 710E. That is, as can be seen from the side sectional view of FIG. 42 (b), in the basic structure 700F according to this modification, auxiliary weight bodies 711F to 714F are respectively provided on the lower surfaces of the sides 711E to 714E of the annular structure. The assembly of the annular weight body 710E and the auxiliary weight bodies 711F to 714F functions as a weight body in the basic structure 700F. Therefore, it is possible to increase the mass of the weight body and improve the detection sensitivity.

<<< §8. Combined detection device for angular velocity, acceleration and pressure >>>
So far, in §3 and §4, an embodiment using the inertial sensor according to the present invention as an acceleration sensor is described. In §5, an embodiment using the inertial sensor according to the present invention as an angular velocity sensor is described. In §6, an embodiment of an angular velocity detection device provided with a plurality of sets of angular velocity sensors has been described.

  Here, by combining an inertial sensor that functions as an angular velocity sensor and an inertial sensor that functions as an acceleration sensor, it has a function of detecting both angular velocity and acceleration, and a pressure sensor that detects pressure is added. The embodiment of the combined angular velocity / acceleration / pressure detecting device 4000 having a function of detecting pressure will be described with reference to FIGS. This composite detection apparatus is configured by adding an acceleration sensor and a pressure sensor based on the angular velocity detection apparatus described with reference to FIGS. 30 and 31 in §6-3.

  FIG. 43 is a plan view showing a basic structure used in the composite detection apparatus 4000 (hatching in the figure is given in order to clearly show the shape of the basic structure, and does not show a cross section). ). This composite detection apparatus 4000 is configured by arranging a first inertia sensor A, a second inertia sensor B, a third inertia sensor E, and a pressure sensor F in a matrix of 2 rows and 2 columns. The first inertial sensor A and the second inertial sensor B are angular velocity sensors, while the third inertial sensor E is an acceleration sensor. 43 shows a state in which the basic structure 100AA of the first inertial sensor A and the basic structure 100BB of the second inertial sensor B are juxtaposed side by side, and the lower part of FIG. A state is shown in which the basic structure 100EE of the third inertial sensor E and the basic structure 100FF of the pressure sensor F are juxtaposed side by side.

  Here, the basic structure 100AA of the first inertial sensor A and the basic structure 100BB of the second inertial sensor B are substantially the same as the structures of the basic structures 100A and 100B shown in FIG. That is, the basic structure 100AA includes a first plate-like bridge portion 120A, a second plate-like bridge portion 130A, a weight connection portion 140A, and a weight body 150A, and the basic structure 100BB has the first structure 100BB. A plate-like bridge portion 120B, a second plate-like bridge portion 130B, a weight connection portion 140B, and a weight body 150B are provided. The root end portion of the first plate-like bridge portion 120A and the root end portion of the second plate-like bridge portion 120B are fixed to a device housing (not shown) by fixing portion plate-like members 171 and 172. The

  However, in the case of the embodiment shown here, the root end portion of the first plate-like bridge portion 120A and the root end portion of the second plate-like bridge portion 120B are, as shown, the common annular connecting portion 160 and the fixing portion. It is connected to the fixed portion plate members 171 and 172 via the connection portion 165. The connection through the annular connecting portion 160 is performed in order to suppress vibration leakage to the apparatus housing when the weight bodies 150A and 150B are vibrated, as will be described in detail later.

  In the case of the illustrated example, the annular connecting portion 160 has a first side (upper side in the figure) and a second side (lower side in the figure) extending in a direction parallel to the X axis as one opposite side and parallel to the Y axis. It has a rectangular shape with the third side (left side in the figure) and the fourth side (right side in the figure) extending in the direction as the other opposite side. The root end portion of the first plate-like bridge portion 120A of the first inertial sensor A and the root end portion of the first plate-like bridge portion 120B of the second inertial sensor B are connected to the annular connection portion 160. It is connected to the first side (the upper side in the figure), and the second side (the lower side in the figure) of the annular connection part 160 is connected to the fixing member plate members 171 and 172 via the fixing connection part 165. ing.

  The fixing member plate members 171 and 172 function as a fixing part of the inertial sensor according to the present invention, and the lower surface thereof is fixed to the bottom plate of the apparatus housing. On the other hand, the annular connecting portion 160 and the fixing connecting portion 165 are arranged at positions that are lifted upward from the bottom plate of the apparatus housing. Eventually, the basic structures 100AA and 100BB are supported in a cantilever structure by the annular connecting portion 160 and the fixing connecting portion 165, and the whole is held at a position raised from the bottom plate of the apparatus housing.

  Here, the first inertial sensor A and the second inertial sensor B have structures that are mirror images of each other, the first inertial sensor A is disposed in one space with the YZ plane as a boundary surface, and the other The second inertial sensor B is disposed in the space, and both the inertial sensors A and B have a plane symmetrical structure with respect to the YZ plane. Further, as illustrated, the annular connecting portion 160 and the fixing connecting portion 165 also have a plane symmetrical structure with respect to the YZ plane. Employing such a symmetrical structure is effective in suppressing vibration leakage to the apparatus housing when the weights 150A and 150B are vibrated.

  On the other hand, the third inertial sensor E is an acceleration sensor, but the basic structure 100EE has a mirror image relationship with the basic structure 100AA of the first inertial sensor A. That is, the basic structure 100EE includes a first plate-like bridge portion 120E, a second plate-like bridge portion 130E, a weight connection portion 140E, and a weight body 150E, and the first plate-like bridge portion 120E. The root end portion is fixed to a device housing (not shown) by a fixing portion plate member 171. Here, the basic structure 100EE is held at a position raised from the bottom plate of the apparatus housing. Thus, by adding the third inertial sensor E functioning as an acceleration sensor to the first inertial sensor A and the second inertial sensor B functioning as an angular velocity sensor, both angular velocity and acceleration are detected. A composite detection apparatus having a function can be configured.

  In the illustrated embodiment, a combined detection device for angular velocity / acceleration / pressure is configured by adding a pressure sensor F. The basic structure 100FF constituting the pressure sensor F is configured by a fixing connection portion 180 and a sealing structure 190, as illustrated. As will be described later, the sealed structure 190 is a plate-like structure having a sealed space inside and having a diaphragm portion formed on at least one surface thereof, and the fixing portion plate member 172 via the fixing connection portion 180. It is connected to the. As described above, the lower surface of the fixing member plate-like member 172 is fixed to the bottom plate of the apparatus housing, but the fixing connecting portion 180 and the sealing structure 190 are lifted upward from the bottom plate of the apparatus housing. Placed in position. Therefore, the basic structure 100FF is supported in a cantilever structure by the fixing connection portion 180, and the whole is held at a position raised from the bottom plate of the apparatus housing.

  Here, as shown in FIG. 43, the origin Q of the XYZ three-dimensional global coordinate system is defined at the boundary portion between the plate members 171 and 172 for the fixed portion, and the X axis is on the right side of the figure, and the upward direction of the figure. If the Y axis is defined and the arrangement of the orthogonal projection image of each sensor with respect to the XY plane is considered, the first inertial sensor A is the second quadrant, the second inertial sensor B is the first quadrant, the third The inertial sensor E is arranged in the third quadrant, and the pressure sensor F is arranged in the fourth quadrant. Here, the function does not change even if the positions of the first inertial sensor A and the second inertial sensor B are interchanged, and the function does not change even if the positions of the third inertial sensor E and the pressure sensor F are interchanged. However, the first inertial sensor A and the second inertial sensor B need to be adjacently disposed along the X axis. This is because, in §6-3, as described with reference to FIGS. 30 and 31, when the weights 150A and 150B are vibrated, vibration leakage to the apparatus housing is suppressed.

  Of course, the first inertia sensor A and the second inertia sensor B are arranged in the third quadrant and the fourth quadrant, and the third inertia sensor E and the pressure sensor F are arranged in the first quadrant and the second quadrant. However, such an arrangement is equivalent to an arrangement when the direction of each coordinate axis is defined in the opposite direction in FIG. After all, if an effective arrangement is adopted to suppress vibration leakage to the apparatus housing, the first inertial sensor A and the second inertia are related to the orthogonal projection image with respect to the XY plane in the XYZ three-dimensional coordinate system. If one of the projected images of sensor B is in the first quadrant, the other is in the second quadrant, one of the third inertial sensor E and pressure sensor F is in the third quadrant, and the other is in the fourth quadrant. Good.

  In the embodiment shown in FIG. 43, the first inertial sensor A, the second inertial sensor B, the third inertial sensor E, and the pressure sensor F are surrounded by a frame shape fixed to the apparatus housing. A fixing portion 900 is provided. The frame-shaped fixing unit 900 functions to protect individual sensors from being directly exposed to the outside, and can be used as a part of the apparatus housing as necessary. Thus, in the composite detection device 4000 shown here, the basic structures of the sensors necessary for the four quadrants are arranged, respectively, and the whole is efficiently accommodated inside the rectangular frame-shaped fixing portion 900. Yes. For this reason, a small device suitable for mass production can be realized.

  Subsequently, the detection operation of the composite detection apparatus 4000 will be described. FIG. 44 is a plan view for explaining the operation of the composite detection apparatus 4000 and a block diagram showing each circuit. As described above, the first inertial sensor A composed of the basic structure 100AA and the second inertial sensor B composed of the basic structure 100BB are angular velocity sensors, and the detection operation is performed in §6-3. 30 is exactly the same as the operation of the angular velocity detection apparatus described with reference to FIG. 30 (the position of the origin Q in the XYZ three-dimensional coordinate system is slightly shifted).

  Specifically, a vibration UY ′ (+) along the Y ′ axis is applied to the weight body 150A of the first inertial sensor A, and a weight body 150B of the second inertial sensor B is applied to the weight body 150B. A vibration UX ′ (+) along the axis is given. Here, the vibration UY ′ (+) and the vibration UX ′ (+) are vibrations having the same period, and when the movements of the two centroid points Ga and Gb are synchronized, the two centroids in the X-axis direction. The movements of the points Ga and Gb are in opposite phases. For this reason, the vibration component in the X-axis direction that leaks to the outside is canceled as a whole. On the other hand, since the basic structural bodies 100AA and 100BB are fixed to the apparatus housing via the annular connection portion 160, vibration components in the Y-axis direction that are likely to leak to the outside are greatly increased by the annular connection portion 160. The part will be absorbed.

  Eventually, the vibration component that leaks to the apparatus housing through the annular connection portion 160 is sufficiently damped regardless of whether it is the X-axis direction component or the Y-axis direction component. Vibration that is transmitted and leaks to the outside is greatly suppressed. Since the third inertial sensor E and the pressure sensor F, which are acceleration sensors, do not generate vibration components in the first place, it is not necessary to take measures against vibration leakage for these sensors. Even if the weight bodies 150A and 150B are vibrated in the manner shown in FIG. 31, the same vibration leakage effect can be obtained.

  As described in §6-3, the angular velocity detection device in which the first inertial sensor A and the second inertial sensor B are incorporated is the detected value of each of the angular velocities ωX ′, ωY ′, ωZ, or conversion processing based on them. The detected values of the angular velocities ωX, ωY, and ωZ obtained in step 1 can be obtained.

  On the other hand, the third inertial sensor E is an acceleration sensor, and its detection operation has already been described in §3 and §4. Since this acceleration sensor has a function of independently detecting each coordinate axis direction component αx, αy, αz of the applied acceleration in the xyz three-dimensional local coordinate system, these detected values are directly used in the XYZ three-dimensional global coordinate system. Each coordinate axis direction component αX, αY, αZ can be output. It is also possible to obtain an acceleration component αX ′ in the X′-axis direction obtained by rotating the X axis by 45 ° and an acceleration component αY ′ in the Y′-axis direction obtained by rotating the Y axis by 45 ° by performing a vector composition operation. It is.

  Further, the pressure sensor F has a function of electrically detecting the pressure applied from the outside and outputting it as a pressure detection value P, and detects the atmospheric pressure in the environment where the composite detection device 4000 is placed. It is possible. The specific structure and operating principle of the pressure sensor F will be described later.

  The block diagram shown in the lower part of FIG. 44 shows the basic configuration of each detection circuit included in the composite detection apparatus 4000. Here, the detection circuits 510A and 510B are detection circuits for the inertial sensors A and B that function as angular velocity sensors, respectively, and their configuration examples and detection operations are as described in §6-3 and the like. The acceleration detection circuit 520E is a detection circuit for the inertial sensor E that functions as an acceleration sensor, and a configuration example thereof is as described in §3 and §4. The pressure detection circuit 530F is a circuit for performing a pressure detection operation by the pressure sensor F, and an example thereof will be described later with reference to FIG.

  In addition to the function of the angular velocity output unit 550 shown in FIG. 21, the composite detection value output unit 570 has a function of outputting a detection value of acceleration detected by the third inertial sensor E and a pressure detected by the pressure sensor F. This is a component having a function of outputting the detection value P. Eventually, from this composite detection value output unit 570, accelerations αX ′, αY ′, αZ are applied to the three-axis components of angular velocities ωX ′, ωY ′, ωZ or the three-axis components of angular velocities ωX, ωY, ωZ as shown in the figure. A detected value indicating a total of 6-axis components obtained by adding the 3-axis components or the 3-axis components of accelerations αX, αY, and αZ, and the pressure detection value P are output.

  Next, the specific structure and operating principle of the pressure sensor F will be described. The basic structure 100FF constituting the pressure sensor F shown in FIG. 44 is configured by the fixing connection portion 180 and the sealing structure 190 as described above. In the case of the illustrated example, the sealed structure 190 is a plate-shaped structure having a sealed space 195 inside and having a diaphragm portion Df formed on the upper surface. The pressure sensor F includes the basic structure 100FF, pressure detection elements 351 to 354, and a pressure detection circuit 530F. The pressure detection elements 351 to 354 are elements that output an electrical signal corresponding to the deflection of the diaphragm portion Df caused by the pressure applied from the outside, and the pressure detection circuit 530F is an output of the pressure detection elements 351 to 354. This is a circuit for obtaining a pressure detection value P based on a signal.

  FIG. 45 is a side cross-sectional view of the sealed structure 190 shown in FIG. 44 cut along a cross section taken along the cutting line 45-45. In the drawing, in order to clarify the position of the sealing structure 190, the bottom plate 200 of the apparatus housing is also drawn. As described above, the lower surface of the fixing portion plate member 172 shown in FIG. 44 is fixed to the bottom plate 200 of the apparatus housing, but the sealing structure 190 is fixed to the fixing portion plate shape via the fixing connection portion 180. It is connected to the member 172 and is held at a position raised upward from the bottom plate 200 of the apparatus housing as shown in the figure.

  The sealed structure 190 is a plate-like structure having a sealed space 195 inside and having a diaphragm portion Df formed on the upper surface. In the illustrated example, the sealed structure 190 is configured by an SOI (Silicon on Insulator) substrate. Therefore, it has a three-layer structure. That is, the sealed structure 190 shown in this example is configured by an SOI substrate in which a first silicon layer 191, a silicon oxide layer 192, and a second silicon layer 193 are stacked in order from the top to the bottom. A sealed space 195 is formed between the inner surface of the groove dug in the upper surface of the layer 193 and the lower surface of the silicon oxide layer 192. Here, the inside of the sealed space 195 is evacuated and functions as a vacuum chamber.

  As in the example shown here, when the sealed structure 190 is formed of an SOI substrate, an advantage of facilitating the process of creating a vacuum sealed space 195 inside can be obtained. A general SOI substrate manufacturing process is performed by bonding a second silicon substrate having a silicon oxide layer formed on an upper surface thereof to a lower side of a first silicon substrate having a silicon oxide layer formed on a lower surface. Therefore, if a groove is dug in the upper surface of the second silicon substrate and bonded to each other in a vacuum before bonding, a sealed structure 190 as shown in FIG. 45 can be manufactured. Can do.

  When the bonding process is performed, the silicon oxide layer formed on the lower surface of the first silicon substrate and the silicon oxide layer formed on the upper surface of the second silicon substrate are strongly bonded, and the degree of vacuum of the sealed space 195 is increased. Well maintained. In general, the thickness of the silicon layer of the first silicon substrate is too thick as a layer constituting the diaphragm portion Df. Therefore, after bonding both substrates, the silicon layer on the upper surface is polished and thinned to obtain an optimum thickness. What is necessary is just to make it form the diaphragm part Df with.

  In FIG. 45, the thickness ratio of each layer is drawn inaccurately for the sake of illustration, but in reality, the first silicon layer 191 and the silicon oxide layer 192 are bent to a degree due to fluctuations in atmospheric pressure. The upper portion of the sealed space 195 in the stacked body of the first silicon layer 191 and the silicon oxide layer 192 constitutes the diaphragm portion Df. Therefore, the diaphragm portion Df bends due to a change in atmospheric pressure, and the volume of the sealed space 195 changes.

  The pressure detection elements 351 to 354 are elements for electrically detecting such deflection generated in the diaphragm portion Df, and are formed on the upper surface of the first silicon layer 191. In the example shown here, piezoresistive elements are used as the pressure detecting elements 351 to 354. In the side sectional view of FIG. 45, only two sets of piezoresistive elements 353 and 354 appear, but actually, as shown in the plan view of FIG. 44, there are a total of four on the upper surface of the first silicon layer 191. A pair of piezoresistive elements 351 to 354 are arranged (here, the piezoresistive elements are indicated by black rectangles in any of the drawings).

  In the case of the embodiment shown here, the outline 197 of the sealed space 195 has a rectangular shape as indicated by a broken line in the plan view of FIG. In other words, the contour 197 of the orthogonal projection image of the sealed space 197 with respect to the upper surface of the diaphragm portion Df is rectangular. Here, for convenience of explanation, in the plan view of FIG. 44, if the four sides of the outline rectangle are defined as the upper side, the lower side, the left side, and the right side, respectively, the arrangement of the four sets of piezoresistive elements 351 to 354 is as follows. ing.

  First, the first piezoresistive element 351 is arranged in the vicinity of the center of the upper side in the outline rectangle 197 so that the direction perpendicular to the upper side (the Y-axis direction in the drawing) is the longitudinal direction. The second piezoresistive element 352 is arranged in the outline rectangle 197 in the vicinity of the center of the lower side so that the direction perpendicular to the lower side (the Y-axis direction in the drawing) is the longitudinal direction. On the other hand, the third piezoresistive element 353 is arranged in the outline rectangle 197 in the vicinity of the center of the left side so that the direction of the left side (the Y-axis direction in the drawing) is the longitudinal direction. The piezoresistive element 354 is arranged inside the outline rectangle 197 in the vicinity of the center of the right side so that the direction of the right side (the Y-axis direction in the drawing) is the longitudinal direction.

  In short, the four sets of piezoresistive elements 351 to 354 are arranged in the inner region near the center of the four sides of the outline rectangle 197 so that the direction parallel to the Y axis is the longitudinal direction. The piezoresistive element is an element that detects a change in electrical resistance with the longitudinal direction as a current path, and can electrically detect mechanical expansion and contraction in the longitudinal direction. Here, when the diaphragm portion Df bends due to a change in the atmospheric pressure, the first piezoresistive element 351, the second piezoresistive element 352, the third piezoresistive element 353, and the fourth piezoresistive are caused by the bend. A completely opposite resistance change occurs with the piezoresistive element 354, and when one resistance value increases, the other resistance value decreases. By utilizing such a resistance change, the pressure can be detected by a bridge circuit.

  FIG. 46 is a circuit diagram showing a bridge circuit constituting the pressure detection circuit 530F of FIG. As shown in the figure, the bridge circuit includes a first piezoresistive element 351 and a second piezoresistive element 352 on one side, and a third piezoresistive element 353 and a fourth piezoresistive element 354 on the other side. The circuit is the opposite side, and a predetermined reference voltage is applied from the power supply 300. For this reason, the bridge voltage Vp corresponding to the fluctuation of the atmospheric pressure is output between the output terminals T51 and T52, and the pressure detection value P is determined based on the bridge voltage Vp.

  In the pressure sensor F, one predetermined place (one place on the upper left in the figure in the example shown in FIG. 44) of the sealed structure 190 is fixed to the apparatus housing via the fixing connection portion 180. 45, the sealed structure 190 is supported in a suspended state in the apparatus housing. This is advantageous for accurate pressure detection that is not affected by disturbance. If the diaphragm portion Df is bent due to mechanical stress applied from the outside, accurate pressure detection cannot be performed. As shown in the example, if a structure in which the sealed structure 190 is supported in a suspended state in the apparatus housing with a single cantilever structure, stress from the outside affects the deflection of the diaphragm portion Df. Can be eliminated as much as possible, and the atmospheric pressure can be accurately detected.

9b: cutting line (shows the cross-sectional position in FIG. 9 (b))
10: Basic structure 11: Pedestal part 12: Diaphragm part 13: Weight body 14b: Cutting line (shows the cross-sectional position of FIG. 14 (b))
20: Piezoresistive element 30: Bottom plates 100, 100A to 100D of the apparatus housing: Basic structures 100AA to 100FF: Basic structures 110, 110A, 110B: Plate members for fixing portions 110AC, 110BD: Plate members for fixing portions 120, 120A to 120E: first plate-like bridge portion 125: intermediate connection portion 130, 130A to 130E: second plate-like bridge portion 140, 140A to 140E: weight connection portion 150, 150A to 150E: weight body 160: annular connection portion 165: fixing connection portions 171, 172: fixing portion plate member 180: fixing connection portion 190: sealing structure 191: first silicon layer (diaphragm portion)
192: Silicon oxide layer (diaphragm part)
193: Second silicon layer 195: Sealed space (vacuum chamber)
197: Outline rectangle 200: Bottom plate 300 of apparatus housing: Power supplies 301 to 312: Piezoresistive elements 301A to 312A: Piezoresistive elements 301B to 312B: Piezoresistive elements 351 to 354: Piezoresistive elements (pressure detecting elements)
400: device housing cover 410: device housing top plate 420: device housing side plate 500: detection circuit 510, 510A to 510D: detection circuit 520E: acceleration detection circuit 520F: pressure detection circuit 550, 560: angular velocity output Unit 570: composite detection value output unit 600: layered piezoelectric bodies 600b, 600c, 600d1, and 600d2: layered piezoelectric bodies 601 to 612: individual piezoelectric elements / individual upper layer electrodes 601A to 612A: individual piezoelectric elements / individual Upper layer electrodes 601B-612B: individual piezoelectric elements / individual upper layer electrodes 610b, 610c, 610d: individual upper layer electrodes 611b, 611c, 611d: individual upper layer electrodes 612b, 612c, 612d: individual upper layer electrodes 621-633: difference Circuits 641 to 646: AC power source 650: lower layer electrodes 650b, 650c, 650d: Layer electrodes 651-656: AC drive signal / AC drive signal source 700, 700A-700F: Basic structure 710: Ring structure 710E: Ring structure 711-714: Each side 711E-714E of ring structure: Ring structure Sides 711F to 714F: auxiliary weight body 720: first plate-like bridge portion 720E: second plate-like bridge portion 725: intermediate connection portion 725E: intermediate connection portion 730: second plate-like bridge portion 730E: First plate-like bridge portion 740: weight connecting portion 740E: fixed end connecting portion 750: weight body 750E: plate-like fixing portion 800, 800E: bottom plates 801 to 803 of apparatus housing: eaves structure portion 900: frame shape Fixed portion 1000: Angular velocity detection device 2000: Angular velocity detection device 3000: Angular velocity detection device 4000: Composite detection devices A to D: Inertia sensor Df: Diaphragm portion E: Inertia sensor (acceleration Capacitors)
F: Pressure sensors Ga to Gd: Center of gravity L0: Longitudinal axis Lx for fixed portion Lx: Second longitudinal axis (center line)
Ly: first longitudinal axis (center line)
O: origin of xyz three-dimensional coordinate system (local coordinate system) P: pressure detection value Q: origin of XYZ three-dimensional coordinate system (global coordinate system) R1 to R12: reference areas S, S1, S2: symmetry planes T11 to T52 : Output terminals UX, UX (+), UX (-): Vibration in the X-axis direction UX ', UX' (+), UX '(-): Vibration in the X-axis direction UY, UY (+), UY ( -): Y-axis vibration UY ', UY' (+), UY '(-): Y'-axis vibration Ux: x-axis vibration Uy: y-axis vibration Uz: z-axis vibration V: gap portion Vx: x-axis detection voltage Vy: y-axis detection voltage Vz: z-axis detection voltage X: coordinate axis X ′ of the XYZ three-dimensional coordinate system (global coordinate system): axis obtained by rotating the X axis by 45 ° x: coordinate axis Δx (+) of xyz three-dimensional coordinate system (local coordinate system): x-axis positive displacement Y: XYZ three Coordinate axis Y ′ of the dimensional coordinate system (global coordinate system): axis obtained by rotating the Y axis by 45 ° y: coordinate axis Δy (+) of the three-dimensional coordinate system (local coordinate system): displacement Z in the positive direction of the y axis : XYZ three-dimensional coordinate system (global coordinate system) coordinate axis z: xyz three-dimensional coordinate system (local coordinate system) coordinate axis Δz (+): z-axis positive displacement

Claims (10)

An inertial sensor that detects acceleration acting in a predetermined coordinate axis direction in an xyz three-dimensional coordinate system,
a first plate-like bridge portion that extends in the y-axis direction with a first longitudinal axis parallel to the y-axis as a central axis and has flexibility;
A second plate which is connected to the first plate-like bridge portion indirectly via an intermediate connection portion , extends in the x-axis direction about a second longitudinal axis parallel to the x-axis, and has flexibility; A plate-like bridge,
A weight body indirectly connected to the second plate-like bridge portion via a weight connection portion ;
An apparatus housing for housing the first plate-like bridge portion, the second plate-like bridge portion, and the weight body;
A fixing portion for fixing one end of the first plate-like bridge portion to the device housing;
A group of operating elements disposed at a predetermined location of the first plate-like bridge portion and a predetermined location of the second plate-like bridge portion;
A detection circuit for detecting the applied acceleration using the operating element group;
With
The fixing portion fixes a root end portion of the first plate-like bridge portion to the apparatus housing, and a tip portion of the first plate-like bridge portion is connected to the second plate via the intermediate connection portion. Indirectly connected to the root end of the bridge-like bridge portion, the tip of the second plate-like bridge portion is indirectly connected to the corner of the weight body via the weight connection portion, An L-shaped structure is formed by the first plate-like bridge portion and the second plate-like bridge portion, and the weight body is disposed beside the second plate-like bridge portion. ,
The lower surface of the fixed portion is fixed to the upper surface of the bottom plate of the apparatus housing, and the first plate-shaped bridge portion, the second plate-shaped bridge portion, and the weight body are in a state where no external force acts. , Suspended in a suspended state above the bottom plate of the device housing,
When an external force acts on the device casing, the weight body is configured to be displaced in the device casing due to bending of the first plate-like bridge portion and the second plate-like bridge portion,
The operating element group is disposed in the vicinity of the first root end side element group disposed in the vicinity of the root end portion of the first plate-like bridge portion, and in the vicinity of the distal end portion of the first plate-like bridge portion. The first tip end side element group, the second root end side element group disposed in the vicinity of the root end portion of the second plate-like bridge portion, and the tip end portion of the second plate-like bridge portion A second tip portion side element group disposed in the vicinity,
A first reference region, a second reference region, and a third reference region are provided on the surface in the vicinity of the root end portion of the first plate-like bridge portion, and the surface in the vicinity of the tip portion of the first plate-like bridge portion. In addition, a fourth reference region, a fifth reference region, and a sixth reference region are arranged on the surface in the vicinity of the root end portion of the second plate-like bridge portion, a seventh reference region, an eighth reference region, When the ninth reference region is defined on the surface in the vicinity of the tip of the second plate-like bridge portion, the tenth reference region, the eleventh reference region, and the twelfth reference region, respectively,
The first root end side element group is disposed in the first attribute element disposed in the first reference region, the second attribute element disposed in the second reference region, and the third reference region. The first tip side element group includes a fourth attribute element disposed in the fourth reference region and a fifth attribute disposed in the fifth reference region. An element and a sixth attribute element disposed in the sixth reference region;
The second root end side element group is disposed in a seventh attribute element disposed in the seventh reference region, an eighth attribute element disposed in the eighth reference region, and the ninth reference region. And the second tip side element group includes a tenth attribute element arranged in the tenth reference region and an eleventh attribute arranged in the eleventh reference region. An element and a twelfth attribute element disposed in the twelfth reference region;
The second reference area and the fifth reference area are defined so that an orthogonal projection image onto the xy plane is positioned on the projection image of the first longitudinal axis, and the eighth reference area And the eleventh reference region is defined so that an orthogonal projection image onto the xy plane is positioned on the projection image of the second longitudinal axis,
In consideration of the bent structure of the L-shaped structure, when defining the inside and outside of the first plate-like bridge portion and the second plate-like bridge portion,
The first reference area is defined at a position where an orthogonal projection image onto the xy plane is adjacent to the inside of the projection image of the second reference area, and the third reference area is an orthogonal projection onto the xy plane. A projected image is defined at a position adjacent to the outside of the projected image of the second reference region;
The fourth reference area is defined at a position where an orthogonal projection image onto the xy plane is adjacent to the inside of the projection image of the fifth reference area, and the sixth reference area is an orthogonal projection onto the xy plane. A projection image is defined at a position adjacent to the outside of the projection image of the fifth reference region;
The seventh reference area is defined at a position where an orthogonal projection image onto the xy plane is adjacent to the inside of the projection image of the eighth reference area, and the ninth reference area is an orthogonal projection onto the xy plane. A projection image is defined at a position adjacent to the outside of the projection image of the eighth reference region;
The tenth reference area is defined at a position where an orthogonal projection image onto the xy plane is adjacent to the inside of the projection image of the eleventh reference area, and the twelfth reference area is an orthogonal projection onto the xy plane. A projected image is defined at a position adjacent to the outside of the projected image of the eleventh reference region ;
The intermediate connecting portion protrudes outward from the side surface of the tip portion of the first plate-like bridge portion and the flange protruding outward from the side surface of the root end portion of the second plate-like bridge portion. Having a structure part,
The weight connecting portion has a flange structure portion protruding outward from a side surface of a tip portion of the second plate-like bridge portion;
The fixing portion has a fixing portion plate-like member extending along a fixing portion longitudinal axis parallel to the x-axis, and one end of the fixing portion plate-like member has a root of the first plate-like bridge portion. An end is fixed, and the one end of the plate member for the fixed portion is provided with a eaves structure portion protruding outward from the side surface of the root end portion of the first plate-like bridge portion. And
The structure constituted by the plate member for fixing portion, the first plate-like bridge portion, and the second plate-like bridge portion is such that the projected image on the xy plane has a “U” shape. A plate-shaped weight body is arranged in an inner region surrounded by this U-shaped structure.
Each element constituting the operating element group is constituted by a detection element that electrically detects stress acting in the longitudinal direction of the plate-like bridge portion at each arrangement position,
An inertial sensor, wherein a detection circuit detects an acceleration acting in a predetermined coordinate axis direction based on a detection result of the detection element. The inertial sensor according to claim 1,
  The fixing portion is constituted by an annular structure, and the first plate-like bridge portion, the second plate-like bridge portion and the weight body are arranged in an inner region surrounded by the annular structure, and the device When an external force of a predetermined magnitude or more is applied to the housing, the member disposed in the inner region comes into contact with the inner surface of the annular structure, so that the displacement of the member is controlled within a predetermined range. An inertial sensor characterized by comprising: The roles of the fixed portion and the weight body in the inertial sensor according to claim 2 are reversed, the annular structure functioning as the fixed portion in the inertial sensor is caused to function as the weight body, and the weight is reduced in the inertial sensor. In order for the plate-like body functioning as a body to function as a fixing portion, the lower surface of the plate-like body is fixed to the upper surface of the bottom plate of the apparatus housing, and the annular structure is in a state where no external force acts, An inertial sensor characterized by being suspended in a suspended state above the bottom plate of the apparatus housing. In the inertial sensor according to any one of claims 1 to 3,
  The orthographic projection image on the xy plane of the operating element group arranged in the first plate-like bridge portion has a pattern that is line symmetric with respect to the projection image of the first longitudinal axis, and the second plate-like bridge An inertial sensor, wherein an orthographic projection image on an xy plane of an operating element group arranged in a section has a pattern that is line symmetric with respect to a projection image of a second longitudinal axis. In the inertial sensor according to any one of claims 1 to 4,
  Each detection element constituting the operating element group is constituted by a piezoresistive element arranged along the longitudinal direction of the plate-like bridge portion,
  An inertial sensor, wherein a detection circuit detects an acceleration acting in a predetermined coordinate axis direction based on an output of a bridge circuit using the piezoresistive element. The inertial sensor according to claim 5, wherein
  The detection circuit uses the bridge circuit having the first attribute element and the sixth attribute element as the first opposite side, and the third attribute element and the fourth attribute element as the second opposite side, and an acceleration αx applied in the x-axis direction. Detecting acceleration αy acting in the y-axis direction by a bridge circuit having the seventh attribute element and the twelfth attribute element as the first opposite side and the ninth attribute element and the tenth attribute element as the second opposite side Then, the acceleration αz acting in the z-axis direction is detected by a bridge circuit in which the fifth attribute element and the eleventh attribute element are the first opposite sides and the second attribute element and the eighth attribute element are the second opposite sides. An inertial sensor characterized by that. The inertial sensor according to claim 5, wherein
  The detection circuit calculates an acceleration αx applied in the x-axis direction by a bridge circuit having the ninth attribute element and the twelfth attribute element as the first opposite side and the seventh attribute element and the tenth attribute element as the second opposite side. Detecting acceleration αy acting in the y-axis direction by a bridge circuit having the first attribute element and the fourth attribute element as the first opposite side and the third attribute element and the sixth attribute element as the second opposite side In addition, one side formed by connecting the fourth attribute element, the fifth attribute element, and the sixth attribute element in series with one side formed by connecting the tenth attribute element, the eleventh attribute element, and the twelfth attribute element in series. The second side is one side formed by connecting the first attribute element, the second attribute element, and the third attribute element in series and the one side formed by connecting the seventh attribute element, the eighth attribute element, and the ninth attribute element in series. The acceleration αz acting in the z-axis direction is detected by a bridge circuit opposite to the Inertial sensor according to claim. In the inertial sensor according to any one of claims 1 to 4,
  Each detection element constituting the operation element group is constituted by a piezoelectric element that generates a positive or negative charge according to the stretching stress along the longitudinal direction of the plate-like bridge portion,
  An inertial sensor, wherein a detection circuit detects an acceleration acting in a predetermined coordinate axis direction by performing addition and subtraction on the generated charge of each piezoelectric element. The inertial sensor according to claim 8.
  The detection circuit determines x based on the difference between the sum of the charge generated by the first attribute element and the charge generated by the sixth attribute element and the sum of the charge generated by the third attribute element and the charge generated by the fourth attribute element. The acceleration αx acting in the axial direction is detected, and the sum of the generated charge of the seventh attribute element and the generated charge of the twelfth attribute element, and the sum of the generated charge of the ninth attribute element and the generated charge of the tenth attribute element, , The acceleration αy acting in the y-axis direction is detected based on the difference between and the sum of the charge generated by the fifth attribute element and the charge generated by the eleventh attribute element, the charge generated by the second attribute element, and the eighth attribute element. An inertial sensor that detects an acceleration αz acting in the z-axis direction based on a difference between the sum of the generated charge and the generated charge. The inertial sensor according to claim 8.
  The detection circuit determines x based on the difference between the sum of the generated charge of the ninth attribute element and the generated charge of the twelfth attribute element and the sum of the generated charge of the seventh attribute element and the generated charge of the tenth attribute element. The acceleration αx acting in the axial direction is detected, the sum of the charge generated by the first attribute element and the charge generated by the fourth attribute element, and the sum of the charge generated by the third attribute element and the charge generated by the sixth attribute element , The acceleration αy acting in the y-axis direction is detected based on the difference between and the fourth attribute element, the fifth attribute element, the sixth attribute element, the tenth attribute element, the eleventh attribute element, and the twelfth attribute element. Based on the difference between the sum of charges and the sum of generated charges of the first attribute element, the second attribute element, the third attribute element, the seventh attribute element, the eighth attribute element, and the ninth attribute element, in the z-axis direction An inertial sensor that detects an acceleration αz acting on the actuator.

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