JP2011027561A - Vibration gyro using piezoelectric film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a reduction in size, to save electric power, and to improve detection sensitivity. <P>SOLUTION: The vibration gyro includes: a ring vibrating body 11 having a uniform plane; a leg part 15 supporting the vibrating body; and electrodes 13a, 13s, 13t, 13h and a fixed-potential electrode 16 sandwiching the piezoelectric film by upper and lower metal electrodes in the thickness direction. The plurality of electrodes include: a group of driving electrodes 13a including driving electrodes arranged at angles separated circumferentially by (360/N)° of exciting the primary vibration of the vibrating body by the vibration mode of cosNθ and electrodes arranged at angles separated by (180/N)° from the respective electrodes; first detection electrodes 13s arranged at angles separated by (90/N)° from the driving electrodes 13a and detecting the secondary vibration of angular velocity; and second detection electrodes 13t arranged at angles further separated by (180/N)° and detecting the secondary vibration. Each driving electrode 13a is arranged in one or both of the areas from the outer periphery of the vibrating body to the vicinity of the outer periphery or from the inner periphery of the vibrating body to the vicinity of the inner periphery. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vibration gyro using a piezoelectric film, and more specifically to a vibration gyro capable of measuring a change in angular velocity of one axis and a vibration gyro capable of measuring a change in angular velocity of a maximum of three axes.

  In recent years, vibration gyros using piezoelectric materials have been actively developed. Conventionally, a gyro, in which the vibrator itself is made of a piezoelectric material as described in Patent Document 1, has been developed, and there is also a gyro that uses a piezoelectric film formed on the vibrator. For example, in Patent Document 2, a PZT film, which is a piezoelectric material, is used to excite the primary vibration of a vibrating body, and a part of the gyro distortion caused by Coriolis force generated when an angular velocity is applied to the vibrating body. A technique for detecting the above is disclosed.

  On the other hand, as the size of various devices on which the gyro is mounted is becoming smaller and smaller, the miniaturization of the gyro itself is also an important issue. In order to achieve downsizing of the gyro, it is necessary to remarkably increase the processing accuracy of each member constituting the gyro. Further, it can be said that the industry demands not only miniaturization but also further improvement of performance as a gyro, in other words, detection accuracy of angular velocity. However, the gyro structure disclosed in Patent Document 2 does not satisfy the demands for miniaturization and high performance over the past several years.

  In addition to the above technical problem, there is an increasing expectation for a vibrating gyroscope that measures angular velocities with respect to rotation of a plurality of axes (for example, Patent Document 4). However, the development of a vibrating gyroscope having a simple structure that enables downsizing is still halfway.

JP-A-8-271258 JP 2000-9473 A Japanese Patent Application No. 2008-28835 JP 2005-529306 Gazette Special Table 2002-509615 Japanese translation of PCT publication No. 2002-510398

  As described above, it is very difficult to simultaneously satisfy the demand for high performance as a gyro while achieving downsizing and high processing accuracy of a vibration gyro using a piezoelectric film. In general, when the gyro is reduced in size, there is a problem that the signal detected by the detection electrode of the gyro becomes weak when an angular velocity is given to the vibrating body. Therefore, since the size of the vibration gyro reduced in size is small in the difference between the signal that should be detected and the signal that is generated due to an unexpected impact (disturbance) from the outside, it is difficult to improve the detection accuracy of the gyro.

  By the way, there are various kinds of shocks in the unexpected shock from the outside. For example, in the ring-shaped vibrating body described in Patent Document 2 described above, there is an impact that causes a seesaw-like movement in the vertical direction of the surface on which the ring exists with the fixed post at the center of the ring as an axis. By this impact, vibration called a rocking mode is excited. On the other hand, there is an impact in which the entire circumference of the ring-shaped member of the vibrating body supported by the fixed post is bent simultaneously above or below the surface where the ring exists. Due to this impact, vibration called a bounce mode is excited. Even if such an impact occurs in the vibrating gyroscope, it is extremely difficult to establish a technique for detecting an accurate angular velocity.

  In addition, as described above, as the vibration gyro using the piezoelectric film progresses in size, it becomes difficult to improve the detection sensitivity as a gyro even without the above-described disturbance. Therefore, improving the detection sensitivity while reducing the size and power consumption is one of the main requirements for improving the performance of the vibration gyro.

  The present invention greatly contributes to miniaturization and high performance of a vibrating gyroscope using a piezoelectric film by solving the above-described technical problems. The inventors first adopted a ring-shaped vibrating gyroscope, which is considered to have a relatively small influence on the disturbance among the above technical problems, as a basic structure. Then, the inventors diligently researched a structure for solving the above technical problems by causing the piezoelectric film to detect the secondary vibration formed by the excitation of the primary vibration and the Coriolis force. As a result, it has been found that in order to apply a dry process capable of achieving high processing accuracy to a vibrating gyroscope using a piezoelectric film, a specific arrangement of various electrodes in the vibrating gyroscope is necessary. Further, it has been found that by focusing on the driving of the primary vibration, it is possible to improve the detection sensitivity while reducing the size and power consumption. The present invention was created from such a viewpoint. In the present application, the “annular or polygonal vibration gyro” is simply referred to as “ring-shaped vibration gyro”.

  One vibrating gyroscope according to the present invention includes a ring-shaped vibrating body having a uniform plane, a leg portion that flexibly supports the ring-shaped vibrating body, and a plane on or above the ring-shaped vibrating body. And a plurality of electrodes formed by at least one of an upper metal film and a lower metal film sandwiching the piezoelectric film in the thickness direction. Here, the plurality of electrodes described above excite the primary vibration of the ring-shaped vibrating body in the vibration mode of cosNθ when N is a natural number of 2 or more, and are separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including drive electrodes arranged at different angles and at least one drive electrode arranged at any angle (180 / N) ° from each of the drive electrodes; A first group of first members that are arranged at an angle (90 / N) ° clockwise or counterclockwise from the drive electrode and that detect secondary vibrations generated when an angular velocity is applied to the ring-shaped vibrating body. It includes a detection electrode and a group of second detection electrodes that are disposed at an angle of (180 / N) ° from each of the aforementioned first detection electrodes and that detect the aforementioned secondary vibration. Further, each of the drive electrodes, each of the first detection electrodes, and each of the second detection electrodes includes a region from the outer periphery of the ring-shaped vibrating body to the vicinity of the outer periphery. The ring-shaped vibrating body is disposed in one or both of the region from the inner periphery to the vicinity of the inner periphery.

  According to this vibrating gyroscope, a voltage is applied to the piezoelectric element on the plane provided on or above the ring-shaped vibrating body and the voltage signal generated by the distortion of the piezoelectric element is picked up. As a uniaxial angular velocity sensor, excitation of primary vibration and detection of secondary vibration can be performed. In other words, in this vibrating gyroscope, the piezoelectric element is not formed on the side surface of the ring-shaped vibrating body, the primary vibration is excited in the same plane as the plane on which the piezoelectric element on the ring-shaped vibrating body is arranged, and the ring-shaped vibration is generated. Since it has a structure for controlling the movement of the body, it is possible to process the electrode and the ring-shaped vibrating body with high accuracy using a dry process technique. In addition, this vibration gyro has a degree of freedom that can be applied to the vibration mode of cosNθ when N is a natural number greater than or equal to 2 by disposing a piezoelectric element in the above specific region. In addition, by providing the above-described group of drive electrodes, an increase in amplitude or power saving can be achieved as compared with the group of drive electrodes arranged only at an angle of (360 / N) ° in the circumferential direction. The That is, for example, since the former can obtain a large amplitude even when the same voltage is applied to the latter, the detection sensitivity of the vibration gyro is improved. From another viewpoint, the former electric power required to obtain the amplitude of the primary vibration having the same magnitude as the latter can be suppressed. A plurality of examples of cosNθ vibration modes are described in, for example, Japanese Patent Application Publication No. 2005-529306 or Japanese Patent Application No. 2007-209014, which is a patent application by the present applicant. In the present application, “flexible” means “to the extent that the vibrating body can vibrate”. Further, in the present application, the expression “an angle away from the reference electrode” is used to describe the arrangement of the electrodes. The angle here is the value of the azimuth angle of each electrode when the azimuth angle of the reference electrode is 0 degree. The azimuth angle of each electrode is an arbitrary point taken at the circumference of the ring-shaped vibrating body or the center of the ring (for example, when the ring-shaped vibrating body is circular, for example, the center of the circle. The center can be referred to as a “reference point”) and can be an azimuth angle of a straight line from the electrode to the electrode. This straight line can be any straight line that passes through each electrode, and typically passes through the graphical center, center of gravity, or any vertex of each electrode and the center point described above. It can be a straight line. For example, an electrode disposed at an angle of 30 ° from the reference drive electrode means that the center of the electrode and the center of the reference drive electrode have an angle of 30 ° with respect to the azimuth angle of the reference electrode. An electrode in an arrangement as described above. Unless otherwise noted, the angle notation is described in the clockwise direction for the direction in which the angle increases, but even if the direction in which the angle increases is set in the counterclockwise direction, as long as the specified angle condition is satisfied. The angle notation is within the scope of the present invention.

Another vibrating gyroscope of the present invention includes a ring-shaped vibrating body having a uniform plane, a leg portion that flexibly supports the ring-shaped vibrating body, and on or above the plane of the ring-shaped vibrating body. And a plurality of electrodes formed by at least one of an upper metal film and a lower metal film sandwiching the piezoelectric film in the thickness direction. In addition, the plurality of electrodes includes the following (1) and (2):
(1) When N is a natural number equal to or greater than 2, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including electrodes and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes;
(2) When one of the aforementioned drive electrodes is a reference drive electrode and S = 0, 1,..., N (hereinafter the same in this paragraph), the angular velocity of the aforementioned ring-shaped vibrating body is The secondary vibration in the vibration mode of cos (N + 1) θ generated at a given time is detected, and an angle [{360 / (N + 1)} × S] ° away from the reference drive electrode, and the reference drive electrode And [{360 / (N + 1)} × {S + (1/2)}] ° apart from a group of detection electrodes including electrodes arranged at at least one of the angles.
Further, each of the drive electrodes described above includes a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge, and an inner periphery of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Each of the detection electrodes is arranged in the second electrode arrangement region in the plane of the ring-shaped vibrating body. It is arranged so that it is not electrically connected to any of the aforementioned drive electrodes.

  According to this vibrating gyroscope, a voltage is applied to the piezoelectric element on the plane provided on or above the ring-shaped vibrating body and above the specific area, or a voltage signal generated by the distortion of the piezoelectric element is picked up. As a uniaxial angular velocity sensor, excitation of primary vibration and detection of secondary vibration can be performed. That is, in this vibrating gyroscope, the piezoelectric element is not formed on the side surface of the ring-shaped vibrating body, and the same plane as the plane on which the piezoelectric element on the ring-shaped vibrating body is disposed (for example, the XY plane) Because the primary vibration is excited by the in-plane) and the movement of the ring-shaped vibrating body is controlled, the electrode and the ring-shaped vibrating body are processed with high precision using dry process technology. It becomes possible. The vibration gyro detects angular velocity of one axis (for example, X axis) using a vibration mode (hereinafter also referred to as an out-of-plane vibration mode) out of the plane in which the piezoelectric element is disposed. This is a great advantage. In addition, by providing the above-described group of drive electrodes, an increase in amplitude or power saving can be achieved as compared with the group of drive electrodes arranged only at an angle of (360 / N) ° in the circumferential direction. The That is, for example, since the former can obtain a large amplitude even when the same voltage is applied to the latter, the detection sensitivity of the vibration gyro is improved. From another viewpoint, the former electric power required to obtain the amplitude of the primary vibration having the same magnitude as the latter can be suppressed.

Another vibration gyro according to the present invention includes a ring-shaped vibrating body having a uniform plane, a leg portion that flexibly supports the ring-shaped vibrating body, and the plane of the ring-shaped vibrating body or the And a plurality of electrodes formed by at least one of an upper layer metal film and a lower layer metal film that are placed above and sandwich the piezoelectric film in the thickness direction. In addition, the plurality of electrodes includes the following (1) and (2):
(1) When N is a natural number equal to or greater than 2, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including electrodes and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes;
(2) When one of the aforementioned drive electrodes is a reference drive electrode and S = 0, 1,..., N (hereinafter the same in this paragraph), the angular velocity of the aforementioned ring-shaped vibrating body is The secondary vibration of the vibration mode of cos (N + 1) θ generated at a given time is detected, and [{360 / (N + 1)} × {S + (1/4)}] ° away from the reference drive electrode A group of detections comprising an electrode and an electrode arranged at least one of an angle and an angle [{360 / (N + 1)} × {S + (3/4)}] ° away from the reference drive electrode It has an electrode.
Further, each of the drive electrodes described above includes a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge, and an inner periphery of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Each of the detection electrodes is arranged in the second electrode arrangement region in the plane of the ring-shaped vibrating body. It is arranged so that it is not electrically connected to any of the aforementioned drive electrodes.

  Even with this vibrating gyroscope, a voltage is applied to the piezoelectric element on the plane provided on or above the ring-shaped vibrating body and above the specific area, or a voltage signal generated by distortion of the piezoelectric element is picked up. Since the electrode for this is formed, the excitation of the primary vibration and the detection of the secondary vibration can be performed as a uniaxial angular velocity sensor. That is, in this vibrating gyroscope, the piezoelectric element is not formed on the side surface of the ring-shaped vibrating body, and the primary vibration is generated in the same plane as the plane (for example, the XY plane) on which the piezoelectric element on the ring-shaped vibrating body is arranged. Is excited, and the movement of the ring-shaped vibrating body is controlled, so that it is possible to process the electrode and the ring-shaped vibrating body with high accuracy using a dry process technique. In addition, this vibration gyro has a great advantage in that the angular velocity of one axis (for example, the X axis) can be detected using an out-of-plane vibration mode. In addition, by providing the above-described group of drive electrodes, an increase in amplitude or power saving can be achieved as compared with the group of drive electrodes arranged only at an angle of (360 / N) ° in the circumferential direction. The That is, for example, since the former can obtain a large amplitude even when the same voltage is applied to the latter, the detection sensitivity of the vibration gyro is improved. From another viewpoint, the former electric power required to obtain the amplitude of the primary vibration having the same magnitude as the latter can be suppressed.

Another vibration gyro according to the present invention includes a ring-shaped vibrating body having a uniform plane, a leg portion that flexibly supports the ring-shaped vibrating body, and the plane of the ring-shaped vibrating body or the And a plurality of electrodes formed by at least one of an upper layer metal film and a lower layer metal film that are placed above and sandwich the piezoelectric film in the thickness direction. In addition, the plurality of electrodes includes the following (1) and (2):
(1) When N is a natural number greater than or equal to 3, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including electrodes and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes;
(2) When one of the above-described drive electrodes is a reference drive electrode and S = 0, 1,..., N−2 (hereinafter the same in this paragraph), An angle that detects the secondary vibration of the vibration mode of cos (N−1) θ generated when the angular velocity is given, and is separated from the reference drive electrode by [{360 / (N−1)} × S] °. And a group of detections provided with electrodes arranged at least at any angle between [{360 / (N−1)} × {S + (1/2)}] ° from the reference drive electrode Electrode.
Further, each of the drive electrodes described above includes a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge, and an inner periphery of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Each of the detection electrodes is arranged in the second electrode arrangement region in the plane of the ring-shaped vibrating body. It is arranged so that it is not electrically connected to any of the aforementioned drive electrodes.

  Even with this vibrating gyroscope, a voltage is applied to the piezoelectric element on the plane provided on or above the ring-shaped vibrating body and above the specific area, or a voltage signal generated by distortion of the piezoelectric element is picked up. Since the electrode for this is formed, the excitation of the primary vibration and the detection of the secondary vibration can be performed as a uniaxial angular velocity sensor. That is, in this vibrating gyroscope, the piezoelectric element is not formed on the side surface of the ring-shaped vibrating body, and the primary vibration is generated in the same plane as the plane (for example, the XY plane) on which the piezoelectric element on the ring-shaped vibrating body is arranged. Is excited, and the movement of the ring-shaped vibrating body is controlled, so that it is possible to process the electrode and the ring-shaped vibrating body with high accuracy using a dry process technique. In addition, this vibration gyro has a great advantage in that the angular velocity of one axis (for example, the X axis) can be detected using an out-of-plane vibration mode. In addition, by providing the above-described group of drive electrodes, an increase in amplitude or power saving can be achieved as compared with the group of drive electrodes arranged only at an angle of (360 / N) ° in the circumferential direction. The That is, for example, since the former can obtain a large amplitude even when the same voltage is applied to the latter, the detection sensitivity of the vibration gyro is improved. From another viewpoint, the former electric power required to obtain the amplitude of the primary vibration having the same magnitude as the latter can be suppressed.

Another vibration gyro according to the present invention includes a ring-shaped vibrating body having a uniform plane, a leg portion that flexibly supports the ring-shaped vibrating body, and the plane of the ring-shaped vibrating body or the And a plurality of electrodes formed by at least one of an upper layer metal film and a lower layer metal film that are placed above and sandwich the piezoelectric film in the thickness direction. The plurality of electrodes are the following (1) and (2):
(1) When N is a natural number greater than or equal to 3, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including electrodes and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes;
(2) When one of the above-described drive electrodes is a reference drive electrode and S = 0, 1,..., N−2 (hereinafter the same in this paragraph), The secondary vibration in the vibration mode of cos (N−1) θ generated when the angular velocity is given is detected, and {{360 / (N−1)} × {S + (1/4) from the reference drive electrode. )}] [Deg.] Away from the reference drive electrode and [{360 / (N-1)} * {S + (3/4)}] [deg.] Away from the reference drive electrode. And a group of detection electrodes.
Further, each of the drive electrodes described above includes a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge, and an inner periphery of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Each of the detection electrodes is arranged in the second electrode arrangement region in the plane of the ring-shaped vibrating body. It is arranged so that it is not electrically connected to any of the aforementioned drive electrodes.

  Even with this vibrating gyroscope, a voltage is applied to the piezoelectric element on the plane provided on or above the ring-shaped vibrating body and above the specific area, or a voltage signal generated by distortion of the piezoelectric element is picked up. Since the electrode for this is formed, the excitation of the primary vibration and the detection of the secondary vibration can be performed as a uniaxial angular velocity sensor. That is, in this vibrating gyroscope, the piezoelectric element is not formed on the side surface of the ring-shaped vibrating body, and the primary vibration is generated in the same plane as the plane (for example, the XY plane) on which the piezoelectric element on the ring-shaped vibrating body is arranged. Is excited, and the movement of the ring-shaped vibrating body is controlled, so that it is possible to process the electrode and the ring-shaped vibrating body with high accuracy using a dry process technique. In addition, this vibration gyro has a great advantage in that the angular velocity of one axis (for example, the X axis) can be detected using an out-of-plane vibration mode. In addition, by providing the above-described group of drive electrodes, an increase in amplitude or power saving can be achieved as compared with the group of drive electrodes arranged only at an angle of (360 / N) ° in the circumferential direction. The That is, for example, since the former can obtain a large amplitude even when the same voltage is applied to the latter, the detection sensitivity of the vibration gyro is improved. From another viewpoint, the former electric power required to obtain the amplitude of the primary vibration having the same magnitude as the latter can be suppressed.

Another vibration gyro according to the present invention includes a ring-shaped vibrating body having a uniform plane, a leg portion that flexibly supports the ring-shaped vibrating body, and the plane of the ring-shaped vibrating body or the And a plurality of electrodes formed by at least one of an upper layer metal film and a lower layer metal film that are placed above and sandwich the piezoelectric film in the thickness direction. The plurality of electrodes are the following (1) to (3), that is,
(1) When N is a natural number equal to or greater than 2, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including electrodes and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes;
(2) When one of the aforementioned drive electrodes is a reference drive electrode and S = 0, 1,..., N (hereinafter the same in this paragraph), the angular velocity of the aforementioned ring-shaped vibrating body is The secondary vibration in the vibration mode of cos (N + 1) θ generated at a given time is detected, and an angle [{360 / (N + 1)} × S] ° away from the reference drive electrode, and the reference drive electrode A group of first detection electrodes comprising electrodes arranged at least at any angle of [{360 / (N + 1)} × {S + (1/2)}] ° away from
(3) A secondary vibration having a vibration axis at an angle {90 / (N + 1)} ° away from the secondary vibration is detected, and {{360 / (N + 1)} × { S + (1/4)}] [deg.] Away from the reference drive electrode and [{360 / (N + 1)} × {S + (3/4)}] [deg.] Away from the reference drive electrode And a group of second detection electrodes each having an electrode disposed on the surface.
Further, each of the drive electrodes described above includes a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge, and an inner periphery of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Each of the first detection electrodes and each of the second detection electrodes are arranged in the ring-shaped vibration described above. It is arranged in the second electrode arrangement region in the plane of the body and is not electrically connected to any of the aforementioned drive electrodes.

  According to this vibrating gyroscope, a voltage is applied to the piezoelectric element on the plane provided on or above the ring-shaped vibrating body and above the specific area, or a voltage signal generated by the distortion of the piezoelectric element is picked up. As a biaxial angular velocity sensor, excitation of primary vibration and detection of secondary vibration can be performed. That is, in this vibrating gyroscope, the piezoelectric element is not formed on the side surface of the ring-shaped vibrating body, and the primary vibration is generated in the same plane as the plane (for example, the XY plane) on which the piezoelectric element on the ring-shaped vibrating body is arranged. Is excited, and the movement of the ring-shaped vibrating body is controlled, so that it is possible to process the electrode and the ring-shaped vibrating body with high accuracy using a dry process technique. In addition, this vibration gyro has a great advantage in that it can detect angular velocities of two axes (for example, the X axis and the Y axis) using an out-of-plane vibration mode. In addition, by providing the above-described group of drive electrodes, an increase in amplitude or power saving can be achieved as compared with the group of drive electrodes arranged only at an angle of (360 / N) ° in the circumferential direction. The That is, for example, since the former can obtain a large amplitude even when the same voltage is applied to the latter, the detection sensitivity of the vibration gyro is improved. From another viewpoint, the former electric power required to obtain the amplitude of the primary vibration having the same magnitude as the latter can be suppressed.

Of the plurality of electrodes in the above-described two-axis vibration gyro, instead of the detection electrode having the configuration (2) or (3), the detection electrode having the following configuration (revision 2 or revision 3) Is employed as the first detection electrode or the second detection electrode, the same effect as the biaxial angular velocity sensor described above is exhibited. However, the detection electrode having the configuration of (Revision 2 or Revision 3) is arranged on the first electrode arrangement region described above, and the two axes to be detected are X axis and Z axis, or Y axis and Z axis. It becomes an axis.
(Revision 2 or Revision 3) When M = 0, 1,..., N-1 (hereinafter the same in this paragraph), it occurs when an angular velocity is given to the ring-shaped vibrating body described above. The secondary vibration in the vibration mode of cosNθ is detected, and an angle [[360 / N) × {M + (1/4)}] ° away from the above-described reference drive electrode and [(360 / N)} × {M + (3/4)}] a group of detection electrodes comprising electrodes arranged at at least one of the separated angles

Further, if a detection electrode having the following configuration (4) is added as a third detection electrode to a plurality of electrodes in the above-described two-axis vibration gyro, a total of three axes, that is, two axes (for example, X In addition to the angular velocity detection using the out-of-plane vibration mode (axis and Y axis), the angular velocity can be detected using the in-plane vibration mode of one axis (for example, the Z axis). Is a big advantage. However, the detection electrode having the configuration (4) is arranged on the first electrode arrangement region.
(4) When M = 0, 1,..., N−1 (hereinafter the same in this paragraph), the vibration mode of cosNθ generated when an angular velocity is applied to the ring-shaped vibrating body. And ([360 / N) × {M + (1/4)}] ° away from the reference drive electrode and [(360 / N)} × from the reference drive electrode. {M + (3/4)}] a group of third detection electrodes each having an electrode disposed at at least one of the angles separated from each other

Another vibration gyro according to the present invention includes a ring-shaped vibrating body having a uniform plane, a leg portion that flexibly supports the ring-shaped vibrating body, and the plane of the ring-shaped vibrating body or the And a plurality of electrodes formed by at least one of an upper layer metal film and a lower layer metal film that are placed above and sandwich the piezoelectric film in the thickness direction. The plurality of electrodes are the following (1) to (3), that is,
(1) When N is a natural number greater than or equal to 3, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including electrodes and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes;
(2) When one of the above-described drive electrodes is a reference drive electrode and S = 0, 1,..., N−2 (hereinafter the same in this paragraph), An angle that detects the secondary vibration of the vibration mode of cos (N−1) θ generated when the angular velocity is given, and is separated from the reference drive electrode by [{360 / (N−1)} × S] °. And a reference driving electrode [{360 / (N−1)} × {S + (1/2)}] ° apart from the reference driving electrode. 1 detection electrode;
(3) A secondary vibration having a vibration axis at an angle of {90 / (N-1)} ° with respect to the secondary vibration is detected, and [{360 / (N-1 )} × {S + (1/4)}] ° and an angle [{360 / (N−1)} × {S + (3/4)}] ° away from the reference drive electrode. And a group of second detection electrodes each having an electrode disposed at at least one of the angles.
Further, each of the drive electrodes described above includes a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge, and an inner periphery of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Each of the first detection electrodes and each of the second detection electrodes are arranged in the ring-shaped vibration described above. It is arranged in the second electrode arrangement region in the plane of the body and is not electrically connected to any of the aforementioned drive electrodes.

  According to this vibrating gyroscope, a voltage is applied to the piezoelectric element on the plane provided on or above the ring-shaped vibrating body and above the specific area, or a voltage signal generated by the distortion of the piezoelectric element is picked up. As a biaxial angular velocity sensor, excitation of primary vibration and detection of secondary vibration can be performed. That is, in this vibrating gyroscope, the piezoelectric element is not formed on the side surface of the ring-shaped vibrating body, and the primary vibration is generated in the same plane as the plane (for example, the XY plane) on which the piezoelectric element on the ring-shaped vibrating body is arranged. Is excited, and the movement of the ring-shaped vibrating body is controlled, so that it is possible to process the electrode and the ring-shaped vibrating body with high accuracy using a dry process technique. In addition, this vibration gyro has a great advantage in that it can detect angular velocities of two axes (for example, the X axis and the Y axis) using an out-of-plane vibration mode. In addition, by providing the above-described group of drive electrodes, an increase in amplitude or power saving can be achieved as compared with the group of drive electrodes arranged only at an angle of (360 / N) ° in the circumferential direction. The That is, for example, since the former can obtain a large amplitude even when the same voltage is applied to the latter, the detection sensitivity of the vibration gyro is improved. From another viewpoint, the former electric power required to obtain the amplitude of the primary vibration having the same magnitude as the latter can be suppressed.

Of the plurality of electrodes in the above-described two-axis vibration gyro, instead of the detection electrode having the configuration (2) or (3), the detection electrode having the following configuration (revision 2 or revision 3) Is employed as the first detection electrode or the second detection electrode, the same effect as the biaxial angular velocity sensor described above is exhibited. However, the detection electrode having the configuration of (Revision 2 or Revision 3) is arranged on the first electrode arrangement region described above, and the two axes to be detected are X axis and Z axis, or Y axis and Z axis. It becomes an axis.
(Revision 2 or Revision 3) When M = 0, 1,..., N-1 (hereinafter the same in this paragraph), it occurs when an angular velocity is given to the ring-shaped vibrating body described above. The secondary vibration in the vibration mode of cosNθ is detected, and the angle away from the drive electrode [(360 / N) × {M + (1/4)}] ° and the reference drive electrode [(360 / N) } × {M + (3/4)}] ° A group of detection electrodes including electrodes arranged at at least one of the angles separated from each other

Further, if a detection electrode having the following configuration (4) is added as a third detection electrode to a plurality of electrodes in the above-described two-axis vibration gyro, a total of three axes, that is, two axes (for example, X In addition to the angular velocity detection using the out-of-plane vibration mode (axis and Y axis), the angular velocity can be detected using the in-plane vibration mode of one axis (for example, the Z axis). Is a big advantage. However, the detection electrode having the configuration (4) is arranged on the first electrode arrangement region.
(4) When M = 0, 1,..., N−1 (hereinafter the same in this paragraph), the vibration mode of cosNθ generated when an angular velocity is applied to the ring-shaped vibrating body. And ([360 / N) × {M + (1/4)}] ° away from the reference drive electrode and [(360 / N)} × from the reference drive electrode. {M + (3/4)}] a group of third detection electrodes each having an electrode disposed at at least one of the angles separated from each other

Note that one of the N + 1 or more drive electrodes in the one-axis, two-axis, or three-axis vibration gyro described above replaces the monitor electrode having the following configuration (5). This is a preferable aspect in that the arrangement of the other electrode group and the arrangement of the extraction electrode are facilitated within the limited planar region of the vibrating body.
(5) When M = 0, 1,..., N−1 (hereinafter the same in this paragraph), [(360 / N) × {M + ( 1/2)}] Monitor electrodes arranged at an angle apart

  Further, in order to cancel the influence (detection amount) due to the secondary vibration in the vicinity of the group of drive electrodes in the above-described one-axis, two-axis, or three-axis vibration gyro (in other words, in the following embodiment) It is another preferred embodiment that the monitor electrode is disposed so that the drive gyroscope is in a symmetrical position with one drive electrode in between (as viewed from the front).

  According to one vibration gyro of the present invention, the primary vibration is excited in the same plane as the plane on which the piezoelectric element on the ring-shaped vibrating body is disposed without forming the piezoelectric element on the side surface of the ring-shaped vibrating body, In addition, the movement of the ring-shaped vibrator can be controlled. Moreover, it becomes possible to process an electrode and a ring-shaped vibrating body with high precision using a dry process technique for a plane provided in the ring-shaped vibrating body. In addition, this vibrating gyroscope is provided with an electrode for applying a voltage to the piezoelectric element in a specific region or picking up a voltage signal generated by the distortion of the piezoelectric element. It has a degree of freedom that can be applied to the vibration mode of cosNθ when a certain natural number is used. In addition, one vibrating gyroscope according to the present invention includes a drive electrode disposed at an angle separated by (360 / N) ° in the circumferential direction and an angle separated from each of the drive electrodes by (180 / N) °. And a group of drive electrodes including at least one drive electrode arranged in a row. Accordingly, an increase in amplitude or power saving is achieved as compared with a group of drive electrodes arranged only at an angle (360 / N) ° in the circumferential direction.

  According to another vibration gyro of the present invention, the primary vibration is excited in the same plane as the plane on which the piezoelectric element on the ring-shaped vibrating body is disposed without forming the piezoelectric element on the side surface of the ring-shaped vibrating body. And the movement of the ring-shaped vibrator can also be controlled. In addition, an electrode for applying a voltage to the piezoelectric element or picking up a voltage signal generated by the distortion of the piezoelectric element on or above the plane provided in the ring-shaped vibrating body. Therefore, it is possible to excite primary vibration and detect secondary vibration as a 1-axis to 3-axis angular velocity sensor. That is, in this vibrating gyroscope, the piezoelectric element is not formed on the side surface of the ring-shaped vibrating body, and primary vibration is performed in the same plane as the plane (for example, the XY plane) on which the piezoelectric element on the ring-shaped vibrating body is arranged. Is excited, and the movement of the ring-shaped vibrating body is controlled, so that it is possible to process the electrode and the ring-shaped vibrating body with high accuracy using a dry process technique. The vibration gyro can detect angular velocities of one to three axes using secondary vibration detection means including an out-of-plane vibration mode. In addition, another vibrating gyroscope of the present invention includes a drive electrode disposed at an angle (360 / N) ° circumferentially and an angle (180 / N) ° away from each of the drive electrodes. A group of drive electrodes including at least one drive electrode arranged in any one of them is provided. Accordingly, an increase in amplitude or power saving is achieved as compared with a group of drive electrodes arranged only at an angle (360 / N) ° in the circumferential direction.

It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in one embodiment of the present invention. It is a perspective view of the structure shown in FIG. It is an enlarged view of a part (W section) of FIG. 2A. It is AA sectional drawing of FIG. It is sectional drawing which shows the process of the one part manufacturing process of the ring-shaped vibration gyroscope in the 1st Embodiment of this invention. It is sectional drawing which shows the process of the one part manufacturing process of the ring-shaped vibration gyroscope in the 1st Embodiment of this invention. It is sectional drawing which shows the process of the one part manufacturing process of the ring-shaped vibration gyroscope in the 1st Embodiment of this invention. It is sectional drawing which shows the process of the one part manufacturing process of the ring-shaped vibration gyroscope in the 1st Embodiment of this invention. It is sectional drawing which shows the process of the one part manufacturing process of the ring-shaped vibration gyroscope in the 1st Embodiment of this invention. It is sectional drawing which shows the process of the one part manufacturing process of the ring-shaped vibration gyroscope in the 1st Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibration gyroscope in the 2nd Embodiment of this invention. It is BB sectional drawing of FIG. It is a front view of the structure which plays the central role of the ring-shaped vibration gyroscope in the 3rd Embodiment of this invention. It is CC sectional drawing of FIG. It is a figure which illustrates notionally positive / negative of the electrical signal of a 1st detection electrode and a 2nd detection electrode. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the 4th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibration gyro in the modification of the 4th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the 5th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the 6th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibration gyroscope in the 7th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibration gyroscope in the modification of the 7th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the 8th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the ninth embodiment of the present invention. It is DD sectional drawing of FIG. 15A. It is a figure which illustrates notionally the primary vibration of the vibration mode of cos3 (theta) in the 9th Embodiment of this invention. It is a figure which illustrates notionally the secondary vibration of the vibration mode of cos3 (theta) in the 9th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the tenth embodiment of the present invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the eleventh embodiment of the present invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the twelfth embodiment of the present invention. It is a figure explaining the vibrating body shape in other embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the thirteenth embodiment of the present invention. It is EE sectional drawing of FIG. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the modification (1) of the thirteenth embodiment of the present invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the modification (2) of the thirteenth embodiment of the present invention. It is sectional drawing equivalent to FIG. 2 of the structure which plays the central role of the ring-shaped vibrating gyroscope in the modification (3) of the 13th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in the modification (5) of the thirteenth embodiment of the present invention. It is FF sectional drawing of FIG. It is a figure which illustrates notionally the primary vibration of the vibration mode of cos2 (theta) in the 13th Embodiment of this invention. It is a figure which illustrates notionally the secondary vibration of the vibration mode of in-plane cos2 (theta) in case angular velocity is added around the Z-axis in the 13th Embodiment of this invention. It is a figure which illustrates notionally the secondary vibration of the vibration mode of cos3theta of an out-of-plane when an angular velocity is added around the X-axis in the 13th Embodiment of this invention. It is a figure which illustrates notionally the secondary vibration of the vibration mode of cos3 (theta) of an out-of-plane when an angular velocity is added around the Y-axis in the 13th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibration gyroscope in 14th Embodiment of this invention. It is a figure which illustrates notionally the primary vibration of the vibration mode of cos3 (theta) in the 14th Embodiment of this invention. It is a figure which illustrates notionally the secondary vibration of the vibration mode of cos2theta of an out-of-plane when an angular velocity is added around the X-axis in the 14th Embodiment of this invention. It is a figure which illustrates notionally the secondary vibration of the vibration mode of cos2theta of an out-of-plane when angular velocity is added around the Y-axis in the 14th Embodiment of this invention. It is a figure which illustrates notionally the secondary vibration of the vibration mode of cos3 (theta) in case angular velocity is added around the Z-axis in the 14th Embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in other embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in other embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in other embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in other embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in other embodiment of this invention. It is a front view of the structure which plays the central role of the ring-shaped vibrating gyroscope in other embodiment of this invention.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this description, common parts are denoted by common reference symbols throughout the drawings unless otherwise specified. In the drawings, the elements of the present embodiment are not necessarily shown to scale.

<First Embodiment>
FIG. 1 is a front view of a structure that plays a central role in a ring-shaped vibrating gyroscope 100 according to this embodiment. 2A is a perspective view of the structure shown in FIG. 1, and FIG. 2B is an enlarged view of a part (W portion) of FIG. 2A. FIG. 3 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIGS. 1 to 3, the ring-shaped vibrating gyroscope 100 of this embodiment is roughly classified into three regions. The first configuration includes a silicon oxide film 20 on an upper plane (hereinafter referred to as an upper surface) of a ring-shaped vibrating body 11 formed from a silicon substrate 10, and a piezoelectric film 40 is further formed on the lower layer metal. The region includes a plurality of electrodes 13a, 13s, 13t, and 13h formed by being sandwiched between the film 30 and the upper metal film 50. In the present embodiment, the outer end portion of the upper metal film 50 constituting the plurality of electrodes 13a, 13s, 13t, and 13h is about 1 μm inward from the outer peripheral edge of the ring-shaped vibrating body 11 having a ring-shaped plane having a width of about 40 μm. Formed and its width is about 18 μm. The upper metal film 50 is formed outside a line connecting the centers of both ends of the width of the ring-shaped plane that is the upper surface of the ring-shaped vibrating body 11 (hereinafter simply referred to as a center line).

By the way, in this embodiment, cos 2θ in the same plane as the plane on which the piezoelectric elements on the ring-shaped vibrator are arranged (hereinafter also referred to as in-plane) without forming the piezoelectric elements on the side surfaces of the ring-shaped vibrator. In this vibration mode, the primary vibration of the ring-shaped vibration gyro 100 is excited. Therefore, the breakdown of the plurality of electrodes 13a, 13s, 13t, and 13h is as follows (a) to (d).
(A) Three drive electrodes 13a, 13a, 13a arranged at an angle of 90 ° in the circumferential direction
(B) One monitor electrode 13h arranged at an angle of 90 ° in the circumferential direction from one of the drive electrodes 13a, 13a, 13a
(C) First detection electrodes 13 s and 13 s and second detection electrodes 13 t and 13 t that detect secondary vibration generated when an angular velocity is applied to the ring-shaped vibration gyroscope 100.

  In the present embodiment, the first detection electrodes 13s and 13s are arranged in the circumferential direction from the two drive electrodes 13a and 13a arranged at point-symmetrical positions in the front view among the drive electrodes 13a, 13a and 13a. It is arranged at an angle of 45 ° clockwise. Further, the second detection electrodes 13t, 13t are circumferentially spaced from the first detection electrodes 13s, 13s by 90 °, in other words, the drive electrodes 13a, 13a, 13a are point-symmetric in front view. The two drive electrodes 13a and 13a arranged at the position are arranged at an angle of 45 ° in the counterclockwise direction in the circumferential direction. Since the monitor electrode 13h is used for monitoring the amplitude and frequency of the excited primary vibration, it is sufficient to use a number that can achieve the purpose, and it is not always necessary to use a plurality.

  In the present embodiment, the lower metal film 30 and the upper metal film 50 have a thickness of 100 nm, and the piezoelectric film 40 has a thickness of 3 μm. The thickness of the silicon substrate 10 is 100 μm. Note that the hatched area indicated by V in FIG. 1 or the area indicated by V in FIG. 2B is a space or a gap where no structure constituting the ring-shaped vibrating gyroscope 100 is present, so that the drawing can be easily understood. This area is provided for convenience.

  The second configuration is leg portions 15,..., 15 connected to a part of the ring-shaped vibrating body 11. The leg portions 15,..., 15 are also formed from the silicon substrate 10. Further, the above-described silicon oxide film 20, lower metal film 30, and piezoelectric film 40 that are continuous with those on the ring-shaped vibrating body 11 are formed on the leg portions 15,. .. formed on the entire top surface of 15. Further, on the center line of the upper surface of the piezoelectric film 40, an upper metal film 50 that is the extraction electrodes 14,...

  The third configuration is a fixed end portion for an electrode pad provided with a support column 19 and electrode pads 18,..., 18 formed from the silicon substrate 10 connected to the leg portions 15,. 17,... In the present embodiment, the support column 19 is connected to a package portion of the ring-shaped vibrating gyroscope 100 (not shown) and serves as a fixed end. Further, the ring-shaped vibrating gyroscope 100 of the present embodiment includes electrode pad fixed ends 17,..., 17 as fixed ends other than the support column 19. The electrode pad fixed end portions 17,..., 17 are connected only to the support column 19 and the above-described package portion, and therefore do not substantially hinder the movement of the ring-shaped vibrating body 11. Further, as shown in FIG. 3, leg portions 15,..., 15 are formed on the upper surfaces of the support pillars 19 and the electrode pad fixed ends 17,. The above-described silicon oxide film 20, lower metal film 30, and piezoelectric film 40 that are continuous with those above are formed. Here, the lower metal film 30 formed on the silicon oxide film 20 serves as the fixed potential electrode 16. In addition, on the upper surface of the piezoelectric film 20 formed on the support column 19 and the electrode pad fixed end portions 17,..., 17, the above-described lead continuous with that on the leg portions 15,. Electrodes 14,..., 14 and electrode pads 18,.

  Next, a method for manufacturing the ring-shaped vibrating gyroscope 100 of this embodiment will be described with reference to FIGS. 4A to 4F. 4A to 4F are cross-sectional views corresponding to a part of the range in FIG.

  First, as shown in FIG. 4A, a silicon oxide film 20, a lower metal film 30, a piezoelectric film 40, and an upper metal film 50 are stacked on a silicon substrate 10. Each of the aforementioned films is formed by a known film forming means. In this embodiment, the silicon oxide film 20 is a thermal oxide film by a known means. The lower metal film 30, the piezoelectric film 40, and the upper metal film 50 are all formed by a known sputtering method. In addition, formation of these films | membranes is not limited to the above-mentioned example, It can form also by another well-known means.

Next, a part of the upper metal film 50 is etched. In the present embodiment, after forming a known resist film on the upper metal film 50, the upper metal film 50 shown in FIG. 4B is formed by performing dry etching based on the pattern formed by the photolithography technique. The Here, the dry etching of the upper metal film 50 was performed under known reactive ion etching (RIE) conditions using argon (Ar) or a mixed gas of argon (Ar) and oxygen (O ₂ ).

Thereafter, as shown in FIG. 4C, a part of the piezoelectric film 40 is etched. First, as described above, the piezoelectric film 40 is dry-etched based on the resist film patterned by the photolithography technique. Incidentally, the dry etching of the piezoelectric film 40 of the present embodiment, using argon (Ar) and a mixed gas of _C 2 _{F 6} gas, or argon (Ar) and _C 2 _{F 6} gas and CHF ₃ gas mixed gas This was performed under known reactive ion etching (RIE) conditions.

Subsequently, as shown in FIG. 4D, a part of the lower metal film 30 is etched. In the present embodiment, dry etching is again performed using a resist film patterned by a photolithography technique so that the fixed potential electrode 16 using the lower metal film 30 is formed. In the present embodiment, the fixed potential electrode 16 is used as a ground electrode. In addition, the dry etching of the lower layer metal film 30 of the present embodiment was performed under known reactive ion etching (RIE) conditions using argon (Ar) or a mixed gas of argon (Ar) and oxygen (O ₂ ). .

  By the way, in this embodiment, since the subsequent silicon oxide film 20 and the silicon substrate 10 are continuously etched using the re-formed resist film as an etching mask, the thickness of the resist film is about 4 μm. Is formed. However, even if this resist film disappears during the etching of the silicon substrate 10, the etching rate selectivity with respect to the etchant used for the silicon substrate 10 works advantageously. The performance of 30 is not substantially affected.

Next, as shown in FIGS. 4E and 4F, the silicon oxide film 20 and the silicon substrate 10 are dry-etched using the resist film for etching the lower metal film 30 as described above. The dry etching of the silicon oxide film 20 of the present embodiment was performed under known reactive ion etching (RIE) conditions using argon (Ar) or a mixed gas of argon (Ar) and oxygen (O ₂ ). In addition, a known silicon trench etching technique is applied to the dry etching conditions of the silicon substrate 10 of the present embodiment. Here, the silicon substrate 10 is etched through. Therefore, in the dry etching described above, a protective substrate for preventing the stage on which the silicon substrate 10 is placed from being exposed to plasma during penetration is attached to the lower layer of the silicon substrate 10 with grease having excellent heat conductivity. Done. Therefore, for example, in order to prevent the surface in the direction perpendicular to the thickness direction of the silicon substrate 10 after the penetration, in other words, the etching side surface from being eroded, the dry etching technique described in JP-A-2002-158214 is employed. This is a preferred embodiment.

  As described above, after the central structure of the ring-shaped vibrating gyroscope 100 is formed by etching the silicon substrate 10 and each film laminated on the silicon substrate 10, the process of accommodating the package in a known means, and The ring-shaped vibrating gyroscope 100 is formed through the wiring process.

  Next, the operation of each electrode provided in the ring-shaped vibrating gyroscope 100 will be described. As described above, in this embodiment, the primary vibration of the in-plane cos 2θ vibration mode is excited. Since the fixed potential electrode 16 is grounded, the lower electrode film 30 formed continuously with the fixed potential electrode 16 is uniformly at 0V.

First, as shown in FIG. 1, an AC voltage of 1V _P-0 is applied to the three drive electrodes 13a, 13a, 13a. However, the phase of the voltage applied to the two drive electrodes 13a, 13a arranged at point-symmetric positions in FIG. 1 is opposite to the phase of the voltage applied to the other one drive electrode 13a. . As a result, the piezoelectric film 40 expands and contracts to excite primary vibration. Here, in this embodiment, since the upper metal film 50 is formed outside the center line on the upper surface of the ring-shaped vibrating body 11, the piezoelectric film 40 is not formed on the side surface of the ring-shaped vibrating body 11. The expansion and contraction motion can be converted into the primary vibration of the ring-shaped vibrating body 11.

  Next, the monitor electrode 13h shown in FIG. 1 detects the amplitude and resonance frequency of the primary vibration described above, and transmits a signal to a known feedback control circuit (not shown). The feedback control circuit of the present embodiment controls the frequency of the AC voltage applied to the drive electrodes 13a, 13a, and 13a so as to match the natural frequency of the ring-shaped vibrating body 11, and the amplitude of the ring-shaped vibrating body 11 Is controlled using a signal from the monitor electrode 13h so as to have a certain value. As a result, the ring-shaped vibrating body 11 maintains a constant vibration.

  After the above-described primary vibration is excited, the angular velocity around an axis perpendicular to the plane on which the ring-shaped vibrating gyroscope 100 shown in FIG. 1 is arranged (an axis perpendicular to the paper surface, hereinafter simply referred to as “vertical axis”). In this embodiment, which is an in-plane cos 2θ vibration mode, a secondary vibration having a new vibration axis inclined at 45 ° on both sides with respect to the vibration axis of the primary vibration is generated by the Coriolis force.

This secondary vibration is detected by the two first detection electrodes 13s and 13s and the two second detection electrodes 13t and 13t. In the present embodiment, as shown in FIG. 1, the first detection electrodes 13s and 13s and the second detection electrodes 13t and 13t are arranged corresponding to the vibration axes of the secondary vibration, respectively. Further, all the first detection electrodes 13 s and 13 s and the second detection electrodes 13 t and 13 t are formed outside the center line on the upper surface of the ring-shaped vibrating body 11. Therefore, the positive and negative of the electrical signals of the first detection electrodes 13s and 13s and the second detection electrodes 13t and 13t generated by the secondary vibration excited by the angular velocity are reversed. As shown in FIG. 9, for example, when the ring-shaped vibrating body 11 changes to a vibrating state of the vibrating body 11 a that is vertically elliptical, the position of the first detection electrode 13 s arranged outside the center line. the piezoelectric film 40, while extending in the direction of the arrow shown in a _1, the piezoelectric film 40 of the position of the second detection electrode 13t which is disposed outside the center line is contracted in directions indicated by arrows a ₂ Therefore, their electrical signals are reversed. Similarly, if you change the vibration state of the vibrating body 11b of the ring-shaped vibrating body 11 has an elliptical next, the piezoelectric film 40 of the position of the first detection electrode 13s, while contracts in the direction of the arrow shown in B _1, the piezoelectric film 40 of the position of the second detection electrode 13t, since extending in the direction of the arrow shown in B _2, also in this case, their electrical signal is reversed. In the present application, the vibration axis means an orientation in which the amplitude of the described vibration is the largest, and is indicated by a direction on the ring-shaped vibrating body.

  Here, in the arithmetic circuit 60 which is a known difference circuit, the difference between the electrical signals of the first detection electrodes 13s and 13s and the second detection electrodes 13t and 13t is calculated. As a result, the detection signal has a detection capability that is approximately twice that of either the first detection signal or the second detection signal.

  On the other hand, in the present embodiment, the upper metal film 50, the piezoelectric film 40, and the lower metal film 30 are formed on the leg portions 15,. Here, if the disturbance (impact) accompanied by the vibration that excites the bounce mode described above occurs in the ring-shaped vibrating gyroscope 100, the leg portions 15,. Since the axis moves in one direction, an electrical signal is generated as the piezoelectric film 40 on the legs 15,. However, in this case, since the positive and negative of the above-described electrical signals of the leg portions connected to all the electrodes for detecting the secondary vibration coincide with each other, each difference is obtained by calculating the difference between them in the arithmetic circuit 60. The signal from the unit 15 is substantially canceled.

  On the other hand, when a disturbance that excites rocking mode vibrations occurs, for example, as shown in FIG. 1, the first detection electrodes 13 s and 13 s are arranged at positions 180 ° apart from each other in the circumferential direction. The expansion and contraction of the piezoelectric film 40 on the leg portion connected to the first detection electrodes 13s and 13s is reversed. As a result, the sign of the electrical signal of each first detection electrode 13s is reversed. Therefore, these electric signals cancel each other. The phenomenon described above also applies to the above-described electrical signal of the leg portion connected to each second detection electrode 13t. For this reason, there is no substantial influence on the arithmetic circuit 60 due to the vibration in the rocking mode.

  As described above, the ring-shaped vibrating gyroscope 100 according to the present embodiment includes the two first detection electrodes 13s and 13s and the two second detection electrodes 13t and 13t, thereby increasing the secondary vibration detection capability. Impact resistance against external impacts that excite bounce mode and rocking mode vibrations is also improved.

<Second Embodiment>
FIG. 5 is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 200 according to this embodiment. 6 is a cross-sectional view taken along the line BB in FIG. The ring-shaped vibrating gyroscope 200 of the present embodiment has the same configuration as the ring-shaped vibrating gyroscope 100 of the first embodiment except for the piezoelectric film 40 and the upper metal film 50 in the first embodiment. The manufacturing method is the same as that of the first embodiment except for a part. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 5, for the sake of convenience, the arithmetic circuit 60 in FIG.

  As shown in FIGS. 5 and 6, the ring-shaped vibrating gyroscope 200 of the present embodiment includes second detection electrodes 213 t and 213 t instead of the second detection electrodes 13 t and 13 t of the first embodiment. The outer end portions of the upper metal film 50 of the second detection electrodes 213t and 213t of the present embodiment are formed about 1 μm inside from the inner peripheral edge of the ring-shaped vibrating body 11, and the width thereof is about 18 μm. Further, the upper metal film 50 is formed inside the center line of the ring-shaped plane of the ring-shaped vibrating body 11.

  In the present embodiment, as shown in FIG. 6, the piezoelectric film 40 is etched in accordance with a region where the upper metal film 50 is substantially formed. For this reason, the AC voltage applied to the upper metal film 50 is applied only vertically downward without being affected by the region where the lower metal film 30 is formed. Transmission is prevented. In the present embodiment, after the dry etching step of the upper metal film 50, the remaining resist film on the upper metal film 50 or the metal film 50 itself is used as an etching mask, and then the dry etching is performed under the same conditions as in the first embodiment. By performing the etching, the above-described piezoelectric film 40 is formed. Further, as shown in FIG. 6, in this embodiment, the piezoelectric film 40 is etched in an inclined shape (for example, an inclination angle is 75 °). However, in the present application, the piezoelectric film 40 having a steep slope as shown in FIG. 6 is not substantially visible in the front view of the ring-shaped vibrating gyroscope 200 shown in FIG. Handled.

  Here, when an angular velocity is applied around the vertical axis (direction perpendicular to the paper surface) of the ring-shaped vibrating gyroscope 200 to the ring-shaped vibrating gyroscope 200 in which the primary vibration is excited as in the first embodiment, the secondary vibration is obtained. The vibration is detected by the two first detection electrodes 13s and 13s and the two second detection electrodes 213t and 213t.

  In the present embodiment, as shown in FIG. 5, the first detection electrodes 13s and 13s and the second detection electrodes 213t and 213t are arranged corresponding to the vibration axis of the secondary vibration, respectively. The first detection electrodes 13 s and 13 s are formed outside the center line on the upper surface of the ring-shaped vibrating body 11. On the other hand, the second detection electrodes 213 t and 213 t are formed inside the center line on the upper surface of the ring-shaped vibrating body 11. Accordingly, the positive and negative electrical signals of the first detection electrodes 13s and 13s and the second detection electrodes 213t and 213t generated by the secondary vibration excited by the angular velocity coincide.

  Here, the sum of the electrical signals of the first detection electrodes 13s and 13s and the second detection electrodes 213t and 213t is calculated in an arithmetic circuit which is a known addition circuit (not shown). As a result, the detection signal has a detection capability that is approximately twice that of either the first detection signal or the second detection signal. In addition, it is equivalent to the above-mentioned addition circuit only by connecting the extraction electrodes 14,..., 14 from the first detection electrodes 13s, 13s and the second detection electrodes 213t, 213t instead of the above-described addition circuit. Therefore, the ring-shaped vibrating gyroscope 200 of this embodiment has an advantage that it is extremely simplified in terms of circuit design.

  By the way, in the present embodiment, when it occurs as a disturbance that excites the rocking mode vibration, for example, as shown in FIG. 5, the first detection electrodes 13 s and 13 s are arranged at positions 180 ° apart from each other in the circumferential direction. Therefore, the expansion and contraction of the piezoelectric film 40 on the leg portion connected to the first detection electrodes 13s and 13s is reversed. As a result, the sign of the electrical signal of each first detection electrode 13s is reversed. Therefore, these electric signals cancel each other. The phenomenon described above also applies to the above-described electrical signal of the leg portion connected to each second detection electrode 213t. For this reason, there is no substantial influence on the arithmetic circuit with respect to the vibration in the rocking mode.

  In this embodiment, when a disturbance (impact) that excites bounce mode vibration occurs, the positive and negative of the electrical signals of the leg portions connected to all the electrodes for detecting secondary vibration match, so If they are summed in the circuit, they are not canceled as in the first embodiment. Therefore, the ring-shaped vibrating gyroscope 200 according to the present embodiment does not have impact resistance that excites bounce mode vibration.

  As described above, the ring-shaped vibration gyro 200 of the present embodiment includes the two first detection electrodes 13s and 13s and the two second detection electrodes 213t and 213t, so that the detection capability of the secondary vibration is enhanced.

<Third Embodiment>
FIG. 7 is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 300 according to this embodiment. 8 is a cross-sectional view taken along the line CC of FIG. The ring-shaped vibrating gyroscope 300 of the present embodiment has the same configuration as the ring-shaped vibrating gyroscope 100 of the first embodiment, except for the arrangement of the upper metal film 50 of the first configuration in the first embodiment. The manufacturing method is the same as that of the first embodiment except for a part. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 7, the arithmetic circuit 60 in FIG. 1 is omitted for the sake of convenience in order to make the drawing easy to see.

  As shown in FIGS. 7 and 8, the ring-shaped vibrating gyroscope 300 of the present embodiment includes first detection electrodes 313 s and 313 s instead of the first detection electrodes 13 s and 13 s of the first embodiment, and the first In place of the second detection electrodes 13t and 13t of the embodiment, second detection electrodes 313t and 313t are provided. The outer end portions of the upper metal film 50 of the first detection electrodes 313s and 313s and the second detection electrodes 313t and 313t of the present embodiment are formed about 1 μm inside from the inner periphery of the ring-shaped vibrating body 11, and the width thereof is about 18 μm. Further, the upper metal film 50 is formed inside the center line on the upper surface of the ring-shaped vibrating body 11.

  Here, when an angular velocity is applied around the vertical axis (direction perpendicular to the paper surface) of the ring-shaped vibrating gyroscope 300 to the ring-shaped vibrating gyroscope 300 in which the primary vibration is excited as in the first embodiment, the secondary vibration is obtained. The vibration is detected by the two first detection electrodes 313s and 313s and the two second detection electrodes 313t and 313t.

  In the present embodiment, as shown in FIG. 7, the first detection electrodes 313s and 313s and the second detection electrodes 313t and 313t are arranged corresponding to the vibration axis of the secondary vibration, respectively. The first detection electrodes 313 s and 313 s and the second detection electrodes 313 t and 313 t are formed on the inner side of the center line on the upper surface of the ring-shaped vibrating body 11. Therefore, the positive and negative of the electrical signals of the first detection electrodes 313s and 313s and the second detection electrodes 313t and 313t generated by the secondary vibration excited by the angular velocity are reversed.

  Here, in an arithmetic circuit which is a known difference circuit (not shown), the difference between the electrical signals of the first detection electrodes 313s and 313s and the second detection electrodes 313t and 313t is calculated. As a result, the detection signal has a detection capability that is approximately twice that of either the first detection signal or the second detection signal.

  On the other hand, in the present embodiment, the upper metal film 50, the piezoelectric film 40, and the lower metal film 30 are formed on the leg portions 15,. Here, if the disturbance (impact) that excites the bounce mode vibration described above is generated in the ring-shaped vibration gyro 300, the leg portions 15,... Therefore, an electric signal is generated along with the expansion and contraction of the piezoelectric film 40 on the leg portions 15. However, in this case, since the above-described electrical signals of the leg portions connected to all the electrodes for detecting the secondary vibration match, the above arithmetic circuit calculates the difference between them. The signal from the leg portion 15 is substantially canceled.

  On the other hand, when a disturbance that excites a rocking mode vibration occurs, for example, as shown in FIG. 7, the first detection electrodes 313s and 313s are arranged at positions 180 ° apart from each other in the circumferential direction. The expansion and contraction of the piezoelectric film 40 on the leg portion connected to the first detection electrodes 313s and 313s is reversed. As a result, the sign of the electrical signal of each first detection electrode 313s is reversed. Therefore, these electric signals cancel each other. The phenomenon described above also applies to the above-described electrical signal of the leg portion connected to each second detection electrode 313t. For this reason, there is no substantial influence on the arithmetic circuit with respect to the vibration in the rocking mode.

  As described above, the ring-shaped vibration gyro 300 according to the present embodiment includes the two first detection electrodes 313s and 313s and the two second detection electrodes 313t and 313t, so that the detection capability of the secondary vibration is enhanced. Impact resistance against external impacts that excite bounce mode and rocking mode vibrations is also improved.

<Fourth Embodiment>
FIG. 10A is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 400 according to this embodiment. The ring-shaped vibrating gyroscope 400 of the present embodiment includes an arrangement of the upper metal film 50 of the first configuration related to the monitor electrode and a part of the drive electrodes in the first embodiment, a part of the leg parts 15,. 15 has the same configuration as that of the ring-shaped vibrating gyroscope 100 of the first embodiment except for the arrangement of the extraction electrode 14 and the arrangement of some electrode pads 18. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 10A, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easy to see.

  As shown in FIG. 10A, the ring-shaped vibrating gyroscope 400 of this embodiment includes four monitor electrodes 413h, 413h, 423h, and 423h. , 18 are connected to the electrode pads 18. These monitor electrodes 413h, 413h, 423h, and 423h detect the amplitude and resonance frequency of the primary vibration of the ring-shaped vibrating body 11 and transmit a signal to a known feedback control circuit (not shown), as in the first embodiment. To do. As a result, the ring-shaped vibrating body 11 maintains constant vibration.

  As shown in FIG. 10A, the monitor electrodes 413h, 413h, 423h, and 423h do not necessarily have to be arranged at an angle of (180/2) °, that is, 90 ° from each of the drive electrodes 13a, 13a, and 13a. Even with the arrangement of the monitor electrodes 413h, 413h, 423h, and 423h shown in FIG. 10A, the main effect of the present invention is exhibited. In the present embodiment, the two monitor electrodes 413h and 413h are 90 ° apart from the two drive electrodes 13a and 13a arranged at point-symmetrical positions in the front view among the drive electrodes 13a, 13a and 13a. Centering on the angle, each is arranged at an angle separated by equal angles clockwise and counterclockwise. In addition, since the output of the opposite phase due to the secondary vibration of the ring-shaped vibrating body 11 is mutually suppressed, the magnitude of the primary vibration can be kept constant without being affected by the newly generated secondary vibration. It becomes possible. Further, the other two monitor electrodes 423h and 423h are also centered at an angle of 90 ° from the two drive electrodes 13a and 13a arranged at point-symmetrical positions in the front view among the drive electrodes 13a, 13a and 13a. Are arranged so as to sandwich the other drive electrode 13a at an angle separated by an equal angle clockwise and counterclockwise. With this arrangement, electrical signals due to secondary vibrations that are not detection targets cancel each other, so detection of the primary vibration amplitude and resonance frequency of the ring-shaped vibrating body 11 that is the original role of the monitor electrodes 423h and 423h. Accuracy is improved.

<Modification of Fourth Embodiment>
FIG. 10B is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 420 according to this embodiment. The ring-shaped vibrating gyroscope 420 of the present embodiment includes an arrangement of the upper metal film 50 of the first configuration related to the monitor electrode and a part of the drive electrodes in the first embodiment, a part of the leg parts 15,. 15 has the same configuration as that of the ring-shaped vibrating gyroscope 100 of the first embodiment except for the arrangement of the extraction electrode 14 and the arrangement of some electrode pads 18. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 10B, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easier to see.

  As shown in FIG. 10B, the ring-shaped vibrating gyroscope 420 of this embodiment includes four drive electrodes 13a,. Two monitor electrodes 423h and 423h are arranged in the vicinity of each of the two drive electrodes 13a and 13a. The four monitor electrodes 423h,..., 423h are respectively connected to the electrode pads 18 and 18 through extraction electrodes.

  As shown in FIG. 10B, the four monitor electrodes 423h,..., 423h are not necessarily arranged at an angle of (180/2) °, that is, 90 ° from each of the drive electrodes 13a, 13a, 13a. Absent. Even with the arrangement of the four monitor electrodes 423h,..., 423h shown in FIG. 10B, the main effect of the present invention is exhibited.

  Here, two monitor electrodes 423h and 423h in the vicinity of one drive electrode 13a are two drive electrodes 13a and 13a in which no monitor electrode is disposed in the vicinity of the drive electrodes 13a,. Centering on an angle of 90 °, each drive electrode 13a is sandwiched at an angle that is equidistant clockwise and counterclockwise. With this arrangement, electrical signals due to secondary vibrations that are not detection targets cancel each other, so detection of the primary vibration amplitude and resonance frequency of the ring-shaped vibrating body 11 that is the original role of the monitor electrodes 423h and 423h. Accuracy is improved.

  Further, the four monitor electrodes 423h,..., 423h of the present embodiment can be said to be a group of two sets of monitor electrodes arranged at positions that are point-symmetric in front view, in other words, two-fold symmetry. . For example, even if patterning misalignment occurs due to misalignment of the etching mask in the manufacturing process of the vibrating gyroscope, the arrangement at the point symmetric position reduces the detection sensitivity of one monitor electrode to the other. This can be compensated by an increase in the detection sensitivity of the monitor electrode.

<Fifth Embodiment>
FIG. 11 is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 500 according to this embodiment. The ring-shaped vibrating gyroscope 500 according to the present embodiment includes an arrangement of the upper metal film 50 of the first configuration in the first embodiment, an arrangement of the extraction electrodes 14 on some leg portions 15,. Except for the arrangement of some electrode pads 18,..., 18, the configuration is the same as that of the ring-shaped vibrating gyroscope 100 of the first embodiment. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 11, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easy to see.

  The ring-shaped vibrating gyroscope 500 according to this embodiment includes two monitor electrodes 513h and 513h as shown in FIG. 11, and the monitor electrodes 513h and 513h are connected to the electrode pads 18 and 18 through the extraction electrodes. ing. Similar to the first embodiment, these monitor electrodes 513h and 513h detect the amplitude and resonance frequency of the primary vibration of the ring-shaped vibrating body 11, and transmit a signal to a known feedback control circuit (not shown). As a result, the ring-shaped vibrating body 11 maintains constant vibration.

  As shown in FIG. 11, the monitor electrodes 513h and 513h are not necessarily arranged at an angle of (180/2) °, that is, 90 ° from the drive electrodes 13a, 13a, and 13a. Even with the arrangement of the monitor electrodes 513h and 513h shown in FIG. 11, the main effect of the present invention is exhibited. Here, in the present embodiment, the monitor electrodes 513h and 513h are separated by 90 ° from the two drive electrodes 13a and 13a disposed at point-symmetric positions in the front view among the group of drive electrodes 13a, 13a and 13a. Centering on the angle, each is arranged at an angle separated by an equal angle clockwise. For this reason, similarly to the modification (1) of the fourth embodiment, it is possible to reduce the influence of the nonuniformity of the detection sensitivity due to the positional deviation of the monitor electrodes 513h and 513h caused by the variation in the manufacturing process. . The monitor electrodes 513h and 513h are centered on an angle of 90 ° away from the two drive electrodes 13a and 13a arranged at point-symmetric positions in the front view among the group of drive electrodes 13a, 13a and 13a. The same effect as described above can be obtained even if each of them is arranged at an angle separated by an equal angle counterclockwise.

<Sixth Embodiment>
FIG. 12 is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 600 according to this embodiment. The ring-shaped vibrating gyroscope 600 of the present embodiment includes an arrangement of the upper metal film 50 of the first configuration in the first embodiment, an arrangement of the extraction electrodes 14 on some leg portions 15,. Except for the arrangement of some electrode pads 18,..., 18, the configuration is the same as that of the ring-shaped vibrating gyroscope 100 of the first embodiment. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 12, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easier to see.

  As shown in FIG. 12, the ring-shaped vibrating gyroscope 600 of this embodiment includes two monitor electrodes 613h and 623h, and the monitor electrodes 613h and 623h are connected to the electrode pads 18 and 18 through the extraction electrodes. ing. Similar to the first embodiment, these monitor electrodes 613h and 623h detect the amplitude and resonance frequency of the primary vibration of the ring-shaped vibrating body 11, and transmit signals to a known feedback control circuit (not shown). As a result, the ring-shaped vibrating body 11 maintains constant vibration.

  As shown in FIG. 12, the monitor electrodes 613h and 623h do not necessarily need to be arranged at an angle of (180/2) °, that is, 90 ° from the drive electrodes 13a, 13a, and 13a. Even with the arrangement of the monitor electrodes 613h and 623h shown in FIG. 12, the main effects of the present invention can be obtained. Here, in the present embodiment, the monitor electrodes 613h and 623h are separated by 90 ° from the two drive electrodes 13a and 13a arranged at point-symmetrical positions in the front view among the group of drive electrodes 13a, 13a and 13a. Centered on the other angle, one is arranged counterclockwise and the other is arranged at an angle separated by an equal angle clockwise. As a result, the output of the opposite phase due to the secondary vibration of the ring-shaped vibrating body 11 mutually suppresses, so that the magnitude of the primary vibration can be kept constant without being affected by the newly generated secondary vibration. It becomes possible.

<Seventh Embodiment>
FIG. 13A is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 700 according to this embodiment. The ring-shaped vibrating gyroscope 700 of the present embodiment includes an arrangement of the upper metal film 50 of the first configuration in the first embodiment, an arrangement of the extraction electrodes 14 on some leg portions 15,. Except for the arrangement of some of the electrode pads 18,... The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 13A, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easy to see.

  As shown in FIG. 13A, the ring-shaped vibrating gyroscope 700 of the present embodiment includes two monitor electrodes 713h and 713h, and the monitor electrodes 713h and 713h are connected to the electrode pads 18 and 18 via the extraction electrodes. ing. These monitor electrodes 713h and 713h detect the amplitude and resonance frequency of the primary vibration of the ring-shaped vibrating body 11 and transmit signals to a known feedback control circuit (not shown) as in the first embodiment. As a result, the ring-shaped vibrating body 11 maintains constant vibration.

  In this embodiment, one 713h is arranged in a region from the outer peripheral edge to the vicinity of the outer peripheral edge of the ring-shaped vibrating body 11, and the other 713h is in a region from the inner peripheral edge to the vicinity of the inner peripheral edge. Has been placed. As shown in FIG. 13A, the monitor electrodes 713h and 713h do not necessarily have to be arranged at an angle of (180/2) °, that is, 90 ° from the respective drive electrodes 13a, 13a, and 13a. Even with the arrangement of the monitor electrodes 713h and 713h shown in FIG. 13A, the main effect of the present invention is exhibited. Here, in the present embodiment, the monitor electrodes 713h and 713h are separated by 90 ° from the two drive electrodes 13a and 13a arranged at point-symmetric positions in the front view among the group of drive electrodes 13a, 13a and 13a. Centering on the angle, each is arranged at an angle separated by an equal angle counterclockwise. For this reason, the influence of the nonuniformity of the detection sensitivity accompanying the position shift of the monitor electrodes 413h,..., 413h caused by variations in the manufacturing process is reduced. Even if the monitor electrodes 713h and 713h are arranged at an angle of 90 ° from the drive electrodes 13a, 13a and 13a, respectively, and at an angle apart from each other in the clockwise direction, the same effect as described above can be obtained. Played.

<Modification of the seventh embodiment>
FIG. 13B is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 750 in the present embodiment. The ring-shaped vibrating gyroscope 750 of the present embodiment includes an arrangement of the upper metal film 50 of the first configuration in the first embodiment, an arrangement of the extraction electrodes 14 on some leg portions 15,. Except for the arrangement of some electrode pads 18,..., 18, the configuration is the same as that of the ring-shaped vibrating gyroscope 100 of the first embodiment. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 13B, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easier to see.

  As shown in FIG. 13B, the ring-shaped vibrating gyroscope 750 of the present embodiment includes two monitor electrodes 753h and 753h, and the monitor electrodes 753h and 753h are connected to the electrode pads 18 and 18 via lead electrodes. ing. These monitor electrodes 753h and 753h detect the amplitude and resonance frequency of the primary vibration of the ring-shaped vibrating body 11 and transmit a signal to a known feedback control circuit (not shown), as in the first embodiment. As a result, the ring-shaped vibrating body 11 maintains constant vibration.

  As shown in FIG. 13B, the monitor electrodes 753h and 753h do not necessarily have to be arranged at an angle of (180/2) °, that is, 90 ° from the respective drive electrodes 13a, 13a, and 13a. Even with the arrangement of the monitor electrodes 753h and 753h shown in FIG. 13B, the main effect of the present invention is exhibited. Here, in the present embodiment, the monitor electrodes 753h and 753h are separated by 90 ° from the two drive electrodes 13a and 13a arranged at point-symmetric positions in the front view among the group of drive electrodes 13a, 13a and 13a. Centering on this angle, one on the outer peripheral side of the ring-shaped vibrating body 11 is arranged counterclockwise, and the other on the inner peripheral side of the ring-shaped vibrating body 11 is arranged at an angle separated by equal angles clockwise. . As a result, for this reason, the influence of the nonuniformity of the detection sensitivity accompanying the position shift of the monitor electrodes 753h and 753h caused by the variation in the manufacturing process is reduced.

<Eighth Embodiment>
FIG. 14 is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 800 according to this embodiment. The ring-shaped vibrating gyroscope 800 of the present embodiment is the same as the ring of the first embodiment except for the arrangement of the leg portions 15,..., 15 and the arrangement of the upper metal film 50 of the first configuration in the first embodiment. The same configuration as that of the vibrating gyroscope 100 is provided. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. Incidentally, in FIG. 14, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easy to see. Further, for convenience of drawing, an AC power source connected to the drive electrodes 13a,..., 13a is also omitted. For convenience, the AC power supply may be omitted in other drawings.

  As shown in FIG. 14, the ring-shaped vibrating gyroscope 800 of the present embodiment has each drive electrode 13 a,..., 13 a, each first detection electrode 13 s,. The electrodes 13t,..., 13t are arranged in a region from the outer periphery of the ring-shaped vibrating body 11 to the vicinity of the outer periphery or a region from the inner periphery to the vicinity of the inner periphery.

  Here, in the present embodiment, since six drive electrodes 13a are formed, an increase in the amplitude of primary vibration or power saving is achieved. For example, when the primary vibration of the vibration mode of cosNθ is excited, the group of drive electrodes 13a,..., 13a in the present embodiment has an angle of the drive electrode 13a serving as a reference and a circumferential direction ( As compared with a group of drive electrodes arranged only at an angle of 360 / N) °, an increase in amplitude or power saving is achieved. That is, for example, since the former can obtain a large amplitude even when the same voltage is applied to the latter, the detection sensitivity of the vibration gyro is improved. From another viewpoint, the former electric power required to obtain the amplitude of the primary vibration having the same magnitude as the latter can be suppressed.

  Each of the monitor electrodes 13h and 13h is disposed in a region from the inner peripheral edge of the ring-shaped vibrating body 11 to the vicinity of the inner peripheral edge. In the present embodiment, the phase of the two drive electrodes 13a and 13a having the same angle as the angle at which the monitor electrodes 13h and 13h are arranged, and the four drive electrodes having an angle of 90 ° from each monitor electrode 13h The phases of the two drive electrodes 13a and 13a in the region from the inner peripheral edge of the ring-shaped vibrating body 11 to the vicinity of the inner peripheral edge are the same. On the other hand, the phases of the other two drive electrodes 13a, 13a are opposite to the phases of the four drive electrodes 13a,. The phase detected by the first detection electrodes 13s and 13s arranged in the region from the outer peripheral edge of the ring-shaped vibrating body 11 to the vicinity of the outer peripheral edge extends from the inner peripheral edge to the vicinity of the inner peripheral edge. It becomes the same as the phase which the 1st detection electrodes 13s and 13s of the area | region until are detected. The phase detected by the second detection electrodes 13t and 13t arranged in the region from the outer peripheral edge of the ring-shaped vibrating body 11 to the vicinity of the outer peripheral edge extends from the inner peripheral edge to the vicinity of the inner peripheral edge. This is the same as the phase detected by the second detection electrodes 13t and 13t in the area up to. However, the phase of each first detection electrode 13s is opposite to the phase of each second detection electrode 13t.

  As in this embodiment, various electrodes are arranged in a region from the outer peripheral edge of the ring-shaped vibrating body 11 to the vicinity of the outer peripheral edge, and from the inner peripheral edge to the vicinity of the inner peripheral edge. Even in the case of being arranged in the region, the same effect as the effect of the present invention is exhibited. In particular, when the electrode is disposed in a region from the outer peripheral edge of the ring-shaped vibrating body 11 to the vicinity of the outer peripheral edge and disposed in a region from the inner peripheral edge to the vicinity of the inner peripheral edge, various electrodes are used. However, the ring-shaped vibrating gyroscope 800 of the present embodiment is also a preferable aspect because the driving capability of the ring-shaped vibrating body 11 and the detection capability of secondary vibration are greatly improved.

  In addition, even if the arrangement of part or all of the monitor electrodes 13h and 13h of the ring-shaped vibrating gyroscope 800 of the present embodiment is arranged as in the fourth to eighth embodiments, the fourth to eighth embodiments. The same effect as that of the embodiment is achieved.

<Ninth Embodiment>
FIG. 15A is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 900 according to this embodiment. FIG. 15B is a sectional view taken along the line DD of FIG. 15A. The ring-shaped vibrating gyroscope 900 of the present embodiment is the same as that of the first embodiment except for the arrangement of the upper metal film 50 and the electrode pad fixed ends 17,. The ring-shaped vibrating gyroscope 100 has substantially the same configuration. The manufacturing method is the same as that in the first embodiment except for various patterns formed by photolithography. On the other hand, unlike the first embodiment, the vibration mode of the present embodiment excites the primary vibration of the ring-shaped vibration gyro 100 in the in-plane cos 3θ vibration mode. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 15A, an arithmetic circuit is omitted for the sake of convenience in order to make the drawing easy to see. For convenience of explanation, FIG. 15A shows the X axis and the Y axis. In addition, in the present embodiment, the hatched and V letters described in the drawings of the other embodiments are omitted.

  As shown in FIG. 15A, each upper metal film 50 of the ring-shaped vibrating gyroscope 900 of the present embodiment is formed outside the center line.

  By the way, the vibration mode of the primary vibration of the present embodiment is the in-plane cos 3θ vibration mode shown in FIG. 16A. Further, the vibration mode of the secondary vibration of the present embodiment is a cos 3θ in-plane vibration mode shown in FIG. 16B. Therefore, the breakdown of the plurality of electrodes 13a to 13e is as follows. First, four drive electrodes 13a,..., 13a arranged at an angle of 180 ° in the circumferential direction are arranged. In addition, when one of the four drive electrodes 13a,..., 13a is used as a reference electrode (for example, the drive electrode 13a in the 12 o'clock direction in FIG. 15A), the reference electrode is used. The monitor electrodes 13h and 13h are arranged at angles of 120 ° and 300 ° clockwise in the circumferential direction from. The first detection electrodes 13s, 13s, and 13s are arranged at angles that are 30 °, 150 °, and 270 ° clockwise from the reference electrode in the circumferential direction. In addition, the second detection electrodes 13t, 13t, and 13t are disposed at angles that are 90 °, 210 °, and 330 ° clockwise from the reference electrode in the circumferential direction.

  Here, in this embodiment, since four drive electrodes 13a are formed, an increase in the amplitude of primary vibration or power saving is achieved. In general terms, when the primary vibration of the vibration mode of cosNθ is excited, the group of drive electrodes 13a,... As compared with a group of drive electrodes arranged only at an angle of (360 / N) ° in the circumferential direction, an increase in amplitude or power saving is achieved.

  In this embodiment, as shown in FIG. 15A, lead electrodes 14 and 14 are formed from both ends of some of the various electrodes in order to eliminate the bias of the electric signal. Even if the extraction electrode 14 is formed only from one side of various electrodes, the function as a vibrating gyroscope is not lost.

  Moreover, the 3rd structure of this embodiment is the support | pillar 19 formed from the silicon substrate 10 connected with the above-mentioned leg part 15, ..., 15. In this embodiment, this support | pillar 19 has a function of the fixed end part 17 for electrode pads in 1st Embodiment. Further, on the upper surface of the support column 19, the above-described silicon oxide film 20, the lower metal film 30, and the piezoelectric body that are continuous with those on the leg portions 15,..., 15 except for the fixed potential electrode 16 that is a ground electrode. A film 40 is formed. Here, the lower metal film 30 formed on the silicon oxide film 20 serves as the fixed potential electrode 16. Further, on the upper surface of the piezoelectric film 40 formed above the support column 19, the above-described lead electrodes 14,..., 14 and the electrode pads 18 that are continuous with those on the leg portions 15,. ..., 18 are formed.

  Next, the operation of each electrode provided in the ring-shaped vibrating gyroscope 900 will be described. As described above, in this embodiment, the primary vibration of the in-plane cos 3θ vibration mode is excited. Since the fixed potential electrode 16 is grounded, the lower electrode film 30 formed continuously with the fixed potential electrode 16 is uniformly at 0V.

First, an AC voltage of 1 V _P-0 is applied to the four drive electrodes 13a,. As a result, the piezoelectric film 40 expands and contracts to excite primary vibration. However, when the driving electrode 13a in the 12 o'clock direction of the timepiece of FIG. 15A is used as a reference electrode, the reference electrode and one reference electrode arranged at an angle of 240 ° in the clockwise circumferential direction from the reference electrode. The phase of the voltage applied to the drive electrode 13a is opposite to the phase of the voltage applied to the other two drive electrodes 13a, 13a. Here, in this embodiment, since the upper metal film 50 is formed outside the center line on the upper surface of the ring-shaped vibrating body 11, the piezoelectric film 40 is not formed on the side surface of the ring-shaped vibrating body 11. The expansion and contraction motion can be converted into the primary vibration of the ring-shaped vibrating body 11.

  Next, the two monitor electrodes 13h and 13h arranged at point-symmetrical positions in front view shown in FIG. 15A detect the amplitude and resonance frequency of the primary vibration described above, and send signals to a known feedback control circuit (not shown). Send. The feedback control circuit of the present embodiment controls the frequency of the alternating voltage applied to the drive electrodes 13a,..., 13a and the natural frequency of the ring-shaped vibrating body 11 to coincide with each other. Is controlled using the signals of the monitor electrodes 13h and 13h so that the amplitude of becomes a certain value. As a result, the ring-shaped vibrating body 11 maintains constant vibration.

  Here, when an angular velocity is applied to the ring-shaped vibrating gyroscope 900 around the vertical axis of the ring-shaped vibrating gyroscope 900 (paper surface, that is, a direction perpendicular to the XY plane), the vibration mode is in-plane cos 3θ. In the present embodiment, the Coriolis force generates the secondary vibration shown in FIG. 16B having a new vibration axis inclined at 30 ° on both sides with respect to the vibration axis of the primary vibration shown in FIG. 16A.

  This secondary vibration is detected by the three first detection electrodes 13s, 13s, 13s and the three second detection electrodes 13t, 13t, 13t. Also in the present embodiment, as in the first embodiment, the difference between the electrical signals of the detection electrodes 13s and 13t is calculated in an arithmetic circuit that is a known difference circuit. As a result, the detection signal has about twice the detection capability as compared with the case of either one of the detection electrodes.

  As described above, the ring-shaped vibrating gyroscope 900 of the present embodiment includes the first detection electrode 13s and the second detection electrode 13t, so that the detection capability of the secondary vibration is enhanced even in the vibration mode of cos3θ. In addition, the impact resistance against external shocks that excite vibrations in the bounce mode and the rocking mode is also improved. It should be noted that here, a more general expression including the present embodiment and the above-described embodiments is possible with respect to the impact resistance against the disturbance that excites the rocking mode vibration. That is, when the primary vibration of the vibration mode of cosNθ is excited, the first detection electrode 13s and the second detection electrode 13t are arranged at positions having rotational symmetry every (360 / N) °. This will improve the shock resistance to disturbances that excite vibration.

  Further, even if some of the group of drive electrodes 13a,..., 13a are replaced with the monitor electrodes 13h and 13h of the present embodiment, the function as a vibration gyro is not lost. Rather, the present embodiment has a degree of freedom that the angle or place where the monitor electrode is disposed can be replaced with the drive electrode. Therefore, when it is desired to further increase the amplitude of the primary vibration or to further reduce power consumption, one of the monitor electrodes 13h and 13h of the present embodiment can be replaced with a drive electrode. In other words, it is sufficient that at least one monitor electrode is disposed.

  Furthermore, even if the arrangement of part or all of the monitor electrodes 13h and 13h of the ring-shaped vibrating gyroscope 900 of this embodiment is arranged as in the fourth to eighth embodiments, the fourth to eighth The same effect as that of the embodiment is achieved.

<Tenth Embodiment>
FIG. 17 is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 920 in the present embodiment. The ring-shaped vibrating gyroscope 920 of the present embodiment is the same as the ring of the first embodiment except for the arrangement of the leg portions 15,..., 15 and the arrangement of the upper metal film 50 of the first configuration in the eighth embodiment. The same configuration as that of the vibrating gyroscope 100 is provided. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 17, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easy to see.

By the way, in this embodiment, the primary vibration of the ring-shaped vibration gyro 100 is excited in the in-plane cos 2θ vibration mode. Accordingly, the breakdown of the plurality of electrodes 13a, 13t, 13h, and 13j is as follows (a) to (d). In the present embodiment, there is only one type of detection electrode that detects secondary vibration that occurs when an angular velocity is applied to the ring-shaped vibration gyro 920. However, in order to follow the description of the embodiments so far, this detection electrode is referred to as a second detection electrode.
(A) Three drive electrodes 13a, 13a, 13a arranged at an angle of 90 ° in the circumferential direction
(B) One monitor electrode 13h arranged at an angle of 90 ° in the circumferential direction from one of the drive electrodes 13a, 13a, 13a
(C) Second detection electrodes 13t and 13t for detecting secondary vibration generated when an angular velocity is applied to the ring-shaped vibration gyro 920.
(D) Suppression electrodes 13j and 13j for suppressing secondary vibration based on the voltage signal from the second detection electrode.

  In the present embodiment, the second detection electrodes 13t and 13t are arranged in a circumferential direction from two drive electrodes 13a and 13a arranged at point-symmetrical positions in the front view among the group of drive electrodes 13a, 13a and 13a. Therefore, they are arranged at an angle of 45 ° counterclockwise. Further, the suppression electrodes 13j and 13j are circumferentially spaced from the second detection electrodes 13t and 13t by 90 °, in other words, of the group of drive electrodes 13a, 13a, and 13a, point-symmetric in front view. The two drive electrodes 13a and 13a arranged at the position are arranged at an angle of 45 ° in the circumferential direction and clockwise. In other words, the second detection electrodes 13t and 13t and the suppression electrodes 13j and 13j are ring-shaped vibrations inclined by 45 ° with respect to the vibration axis of the primary vibration generated by the drive electrodes 13a, 13a, and 13a. It is arranged on the vibration axis of the secondary vibration generated when the body 11 is given an angular velocity.

  Next, the operation of each electrode provided in the ring-shaped vibrating gyroscope 920 will be described. As described above, in the present embodiment, the primary vibration of the in-plane cos 2θ vibration mode is excited. Since the fixed potential electrode 16 is grounded, the lower electrode film 30 formed continuously with the fixed potential electrode 16 is uniformly at 0V.

First, as shown in FIG. 17, an AC voltage of 1 V _P-0 is applied to the three drive electrodes 13a, 13a, 13a. However, the phase of the voltage applied to the two drive electrodes 13a, 13a arranged at point-symmetric positions in FIG. 17 is opposite to the phase of the voltage applied to the other one drive electrode 13a. . As a result, the piezoelectric film 40 expands and contracts to excite primary vibration. Here, in this embodiment, since the upper metal film 50 is formed outside the center line on the upper surface of the ring-shaped vibrating body 11, the piezoelectric film 40 is not formed on the side surface of the ring-shaped vibrating body 11. The expansion and contraction motion can be converted into the primary vibration of the ring-shaped vibrating body 11.

  Next, the monitor electrode 13h shown in FIG. 17 detects the amplitude and resonance frequency of the primary vibration described above, and transmits a signal to a known feedback control circuit (not shown). This feedback control circuit controls the frequency of the alternating voltage applied to the drive electrodes 13a, 13a, and 13a to be equal to the natural frequency of the ring-shaped vibrating body 11, and the amplitude of the ring-shaped vibrating body 11 is constant. Is controlled using the signal of the monitor electrode 13h. As a result, the ring-shaped vibrating body 11 maintains constant vibration.

  When an angular velocity is applied around the vertical axis of the ring-shaped vibrating gyroscope 920 shown in FIG. 17 after the above-described primary vibration is excited, in the present embodiment, which is a cos 2θ vibration mode, the vibration axis of the primary vibration is caused by the Coriolis force. On the other hand, a secondary vibration having a new vibration axis inclined at 45 ° on both sides is generated.

  This secondary vibration is detected by the two second detection electrodes 13t and 13t. Here, the ring-shaped vibration gyro 920 of the present embodiment cancels the voltage signal related to the secondary vibration detected by the second detection electrodes 13t and 13t, in other words, sets the value of the voltage signal to zero. In order to do so, feedback control circuits 61 and 62 for instructing or controlling the suppression electrodes 13j and 13j to apply a specific voltage are provided. This specific voltage is used as a result output as a vibrating gyroscope.

  As described above, by providing the suppression electrodes 13j and 13j that suppress the secondary vibration based on the voltage signals from the second detection electrodes 13t and 13t, the ring-shaped vibration gyro 920 can cause the secondary vibration of the ring-shaped vibration body 11 to be secondary. The performance as a vibration gyro can be exhibited with almost no vibration. Note that the ring-shaped vibration gyro 920 of the present embodiment is extremely excellent in noise performance as compared with the vibration gyro in which the suppression electrodes 13j and 13j and the feedback control circuits 61 and 62 are not provided. Specifically, the ring-shaped vibration gyro 920 of the present embodiment is compared with an example of the vibration gyro described in PCT / JP2008 / 071372 previously proposed by the applicant of the present application (vibration gyro of the first embodiment). In particular, the magnitude of noise in the low frequency region is less than half. Therefore, the S / N ratio can be dramatically increased without sacrificing responsiveness. A known feedback control circuit can be applied to the feedback control circuits 61 and 62 described above.

  On the other hand, when a disturbance with vibration that excites the rocking mode occurs in the present embodiment, for example, as shown in FIG. 17, the second detection electrodes 13t and 13t are each 180 degrees apart in the circumferential direction (in other words, , A point-symmetrical position in front view). Therefore, the expansion and contraction of the piezoelectric film 40 on the leg portion connected to each of the second detection electrodes 13t and 13t is reversed even if it occurs. As a result, the sign of the electrical signal of each second detection electrode 13t is reversed. Therefore, since these electric signals cancel each other, there is substantially no adverse effect on the operation of the ring-shaped vibration gyro 920 due to the vibration in the rocking mode.

  As described above, the ring-shaped vibration gyro 920 of the present embodiment includes the two second detection electrodes 13t and 13t and the two suppression electrodes 13j and 13j, thereby increasing the detection capability of the secondary vibration and the rocking mode. The impact resistance against external impacts that excite the vibrations is enhanced.

<Eleventh embodiment>
FIG. 18 is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 940 in the present embodiment. The ring-shaped vibrating gyroscope 940 of the present embodiment has the same configuration as the ring-shaped vibrating gyroscope 800 of the eighth embodiment except for the arrangement of the upper metal film 50 of the first configuration in the eighth embodiment. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 18, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easy to see. For the sake of convenience, the AC power supply connected to the drive electrodes 13a,..., 13a and the feedback control circuit depicted in FIG. 17 of the tenth embodiment are also omitted.

  In the present embodiment, unlike the tenth embodiment, first detection electrodes 13s and 13s and second detection electrodes 13t and 13t for detecting secondary vibration are arranged. Further, the first detection electrodes 13s, 13s are arranged at point-symmetrical positions in the front view among the group of drive electrodes 13a, ..., 13a, and from the inner periphery of the ring-shaped vibrating body 11 to the inner periphery thereof. The two drive electrodes 13a, 13a arranged in the region up to the vicinity are arranged at an angle of 45 ° in the circumferential direction and counterclockwise. Similarly, the second detection electrodes 13t, 13t are arranged at point-symmetrical positions in the front view among the group of drive electrodes 13a,..., 13a, and from the outer periphery of the ring-shaped vibrating body 11 to the outer periphery thereof. The two drive electrodes 13a, 13a arranged in the region up to the vicinity of the two electrodes are arranged at an angle of 45 ° in the circumferential direction and counterclockwise. Further, the four suppression electrodes 13j,..., 13j are at an angle of 90 ° in the circumferential direction from the first detection electrodes 13s, 13s and the second detection electrodes 13t, 13t, in other words, a group of drives. Of the electrodes 13a, ..., 13a, the four drive electrodes 13a, ..., 13a arranged at point-symmetrical positions in front view are circumferentially inclined at an angle of 45 ° clockwise. Be placed. In other words, the first detection electrodes 13s, 13s, the second detection electrodes 13t, 13t, and the suppression electrodes 13j, ..., 13j are primary generated by the drive electrodes 13a, ..., 13a. It is arranged on the vibration axis of secondary vibration generated when an angular velocity is applied to the ring-shaped vibrating body 11, which is inclined by 45 ° with respect to the vibration axis of vibration.

  The ring-shaped vibrating gyroscope 940 of the present embodiment includes suppression electrodes 13j,..., 13j that suppress secondary vibrations based on voltage signals from the first detection electrodes 13s and 13s and the second detection electrodes 13t and 13t. . Therefore, the ring-shaped vibrating gyroscope 940 can exhibit the performance as a vibrating gyroscope while hardly vibrating the secondary vibration of the ring-shaped vibrating body 11. Note that the ring-shaped vibrating gyroscope 940 of the present embodiment is also excellent in noise performance as compared with a vibrating gyroscope in which the suppression electrodes 13j,..., 13j and the feedback control circuit described above are not provided. In particular, in the present embodiment, since the first detection electrodes 13s and 13s and the second detection electrodes 13t and 13t are arranged, noise in the low frequency region is greatly reduced due to the presence of the suppression electrodes 13j,. Can be done. Therefore, the S / N ratio can be dramatically increased without sacrificing responsiveness.

  Further, in the present embodiment, when a disturbance with vibration that excites the rocking mode occurs, for example, as shown in FIG. 18, the first detection electrodes 13s and 13s and the second detection electrodes 13t and 13t are 180 in the circumferential direction. They are arranged at an angle apart (in other words, a point-symmetrical position in front view). Therefore, the expansion and contraction of the piezoelectric film 40 on the leg portions connected to the first detection electrodes 13s and 13s and the second detection electrodes 13t and 13t is reversed even if they occur. As a result, the electrical signals of the first detection electrodes 13s and the second detection electrodes 13t are reversed in polarity, and the electrical signals cancel each other. For this reason, there is substantially no adverse effect on the operation of the ring-shaped vibrating gyroscope 940 due to the vibration in the rocking mode. In the present embodiment, the phase of the first detection electrodes 13s and 13s and the phase of the second detection electrodes 13t and 13t are opposite to each other. It is possible to suppress the influence of disturbance accompanied by vibration that excites the mode.

  As described above, the ring-shaped vibrating gyroscope 940 of the present embodiment includes the two first detection electrodes 13s and 13s, the two second detection electrodes 13t and 13t, and the four suppression electrodes 13j,. As a result, the detection capability of the secondary vibration is enhanced and the impact resistance against an external impact that excites the rocking mode vibration is also enhanced.

<Twelfth Embodiment>
FIG. 19 is a front view of a structure that plays a central role in another ring-shaped vibrating gyroscope 960 according to this embodiment. The ring-shaped vibrating gyroscope 960 of the present embodiment has the same configuration as the ring-shaped vibrating gyroscope 800 of the eighth embodiment, except for the arrangement of the upper metal film 50 of the first configuration in the eighth embodiment. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Furthermore, the vibration mode of the present embodiment is an in-plane cos 2θ vibration mode, as in the first embodiment. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. In FIG. 19, the arithmetic circuit 60 is omitted for the sake of convenience in order to make the drawing easier to see. For the sake of convenience, the AC power supply connected to the drive electrodes 13a,..., 13a and the feedback control circuit depicted in FIG. 17 of the tenth embodiment are also omitted.

  In the present embodiment, four second detection electrodes 13t,..., 13t for detecting secondary vibration are arranged. Further, the ring-shaped vibrating gyroscope 960 of the present embodiment has seven drive electrodes 13a,..., 13a, one monitor electrode 13h, and four suppression electrodes 13j,. The second detection electrodes 13t,..., 13t and the suppression electrodes 13j,..., 13j of the present embodiment are also inclined by 45 ° with respect to the vibration axis of the primary vibration generated by the drive electrodes 13a,. The ring-shaped vibrating body 11 is disposed on the vibration axis of the secondary vibration generated when an angular velocity is given.

  The ring-shaped vibration gyroscope 960 of the present embodiment includes suppression electrodes 13j,..., 13j that suppress secondary vibrations based on voltage signals from the second detection electrodes 13t,. Therefore, the ring-shaped vibrating gyroscope 960 can exhibit the performance as a vibrating gyroscope while hardly vibrating the secondary vibration of the ring-shaped vibrating body 11. Note that the ring-shaped vibrating gyroscope 960 of the present embodiment is also excellent in noise performance as compared with a vibrating gyroscope that is not provided with the suppression electrodes 13j,..., 13j and the feedback control circuit described above. In particular, in this embodiment, the ring-shaped vibrating body 11 is arranged in a region from the outer peripheral edge to the vicinity of the outer peripheral edge and a region from the inner peripheral edge of the ring-shaped vibrating body 11 to the vicinity of the inner peripheral edge. Since the second detection electrodes 13t,..., 13t are arranged, noise in the low frequency region can be greatly reduced by the presence of the suppression electrodes 13j,. Therefore, the S / N ratio can be dramatically increased without sacrificing responsiveness. Further, in the present embodiment, since the phases of the second detection electrodes 13t and 13t are all the same, there is an advantage that a differential circuit is not required, and the S / N ratio is improved as compared with the tenth embodiment.

  By the way, in the embodiments other than the ninth embodiment described above, the cos 2θ vibration mode is employed, but the present embodiment is not limited to this. By adopting a drive electrode that excites the primary vibration of the ring-shaped vibrating body in the vibration mode of cosNθ when N is a natural number of 2 or more, substantially the same effect as the effect of the present invention is achieved. The For example, the arrangement of the electrodes in the ninth embodiment in which the cos 3θ vibration mode is adopted is sufficient for those skilled in the art to arrange the electrodes in the cos 3θ vibration mode corresponding to the first to eighth embodiments described above. Is disclosed. That is, the arrangement of the electrodes in the vibration mode of cosNθ when N is a natural number of 2 or more is sufficiently disclosed by the description of each of the above embodiments.

  Further, as in the fourth to seventh embodiments described above, even in embodiments other than the fourth to seventh embodiments, the one drive electrode is arranged in the vicinity of one drive electrode. A plurality of monitor electrodes may be arranged at an angle apart from each other by an equal angle clockwise and / or counterclockwise around a certain angle.

  In addition, as described above, in the primary vibration mode of the cosNθ vibration mode, two even-numbered drive electrodes arranged at an angle apart from each other in the circumferential direction (180 / N) ° are two Each monitor electrode is used in place of a pair of monitor electrodes, and the monitor electrodes are arranged at point-symmetrical positions in the front view of the vibrating body, or N pieces are arranged every (360 / N) °. Is another preferred embodiment. By adopting this configuration and arrangement, even if patterning misalignment occurs due to misalignment of the etching mask in the manufacturing process of the vibration gyro, the detection sensitivity of one monitor electrode is reduced. This can be compensated by an increase in detection sensitivity.

  Moreover, although each above-mentioned embodiment was demonstrated with the vibration gyro using an annular | circular shaped vibrating body, a polygonal vibrating body may be sufficient instead of an annular shape. For example, even with a regular polygonal vibrator such as a regular hexagon, a regular octagon, a regular dodecagon, and a regular icosahedron, substantially the same effect as the effect of the present invention is exhibited. Moreover, a vibrating body such as the octagonal vibrating body 111 of the ring-shaped vibrating gyroscope 980 shown in FIG. 20 may be used. In the front view of the vibrating body, for example, a polygon having a point-symmetrical shape or an n-fold symmetrical shape (n is an arbitrary natural number) with an arbitrary point such as the reference point described above as the center of symmetry is defined as an outer peripheral edge or an inner peripheral edge. If such a ring-shaped vibrating body is employed, it is preferable from the viewpoint of stability during vibration of the vibrating body. The “annular shape” includes an elliptical shape.

<13th Embodiment>
FIG. 21 is a front view of a structure that plays a central role in the ring-shaped vibrating gyroscope 1000 that measures the triaxial angular velocities in the present embodiment. 22 is a cross-sectional view taken along line EE in FIG. For convenience of explanation, FIG. 21 shows the X axis and the Y axis. The manufacturing method is the same as that of the first embodiment except for a pattern formed by a photolithography technique. Therefore, the description which overlaps with 1st Embodiment is abbreviate | omitted. By the way, also in FIG. 21, in order to make the drawing easy to see, the AC power source connected to the arithmetic circuit 60 and the drive electrodes 13a, 13a, 13a is not shown for convenience.

  As shown in FIGS. 21 and 22, the ring-shaped vibrating gyroscope 1000 of this embodiment is also roughly classified into three configurations. The first configuration includes a silicon oxide film 20 on the upper surface of the silicon substrate 10, and a plurality of piezoelectric films 40 sandwiched between the lower metal film 30 and the upper metal film 50 thereon. It is the structure provided with electrodes 13a-13h. In the present embodiment, the outer end portion or the inner end portion of the upper metal film 50 constituting the plurality of electrodes 13a to 13h is approximately from the outer periphery or inner periphery of the ring-shaped vibrating body 11 having a ring-shaped plane having a width of approximately 40 μm. It is formed inside 1 μm and its width is about 18 μm. Among the upper metal film 50, some electrodes are formed outside the center line of the ring-shaped vibrating body 11, and the other electrodes are formed inside the center line.

By the way, in this embodiment, the primary vibration of the ring-shaped vibrating gyroscope 1000 is excited in the in-plane cos 2θ vibration mode shown in FIG. 28A. In addition, the vibration mode of the secondary vibration of the present embodiment includes the X-axis cos 3θ out-of-plane vibration mode illustrated in FIG. 28C and the Y-axis cos 3θ out-of-plane vibration mode illustrated in FIG. 28D. And the in-plane vibration mode of cos 2θ of one axis (Z axis) shown in FIG. 28B. Therefore, the breakdown of the plurality of electrodes 13a to 13h is as follows (a) to (e).
(A) Three drive electrodes 13a, 13a, 13a arranged at an angle of 90 ° in the circumferential direction
(B) One of the three driving electrodes 13a, 13a, 13a described above (for example, when the driving electrode 13a in the 12 o'clock direction of the timepiece in FIG. 21 is used as a reference electrode, the driving electrode 13a One monitor electrode 13h arranged at an angle of 90 ° in the circumferential direction
(C) First detection electrodes 13b and 13c arranged in the circumferential direction from the reference electrode at angles of 0 °, 60 °, 120 °, 180 °, 240 °, and 300 °.
(D) Second detection electrodes 13d and 13e arranged at an angle of 30 °, 90 °, 150 °, 210 °, 270 ° and 330 ° in the circumferential direction from the reference electrode.
(E) Third detection electrodes 13f and 13g disposed in the circumferential direction from the reference electrode at angles of 45 °, 135 °, 225 °, and 315 °.

  The first detection electrodes 13b and 13c described above are ring-shaped vibrating gyros when the plane on which the piezoelectric elements on the ring-shaped vibrating body 1000 are arranged, in other words, when the paper surface in FIG. The secondary vibration generated when the angular velocity around the X axis is given to 1000 is detected. Similarly, the second detection electrodes 13d and 13e described above detect the secondary vibration that occurs when the ring-shaped vibration gyroscope 1000 is given an angular velocity around the Y axis. Further, the third detection electrodes 13f and 13g described above are provided on the ring-shaped vibrating gyroscope 1000 with the Z axis, that is, the axis perpendicular to the plane on which the ring-shaped vibrating gyroscope 1000 shown in FIG. Hereinafter, the secondary vibration generated when an angular velocity around the “vertical axis” or “Z axis” is given is detected.

  In the present embodiment, the lower metal film 30 and the upper metal film 50 have a thickness of 100 nm, and the piezoelectric film 40 has a thickness of 3 μm. The thickness of the silicon substrate 10 is 100 μm.

  In the present embodiment and other embodiments described later, the region where each electrode is arranged is classified into two. One is each drive electrode arranged in the region from the outer peripheral edge of the upper surface of the ring-shaped vibrating body 11 to the vicinity of the outer peripheral edge and / or the region from the inner peripheral edge to the vicinity of the inner peripheral edge. 13a and third detection electrodes 13f and 13g. This is defined as a first electrode arrangement region. The other is the first detection electrodes 13b and 13c and the second detection electrodes 13d and 13e arranged on the upper surface of the ring-shaped vibrating body 11 so as not to be in electrical contact with the first electrode arrangement region. is there. This is the second electrode arrangement region. More specifically, the first detection electrodes 13b and 13c and the second detection electrodes 13d and 13e are arranged so as not to be electrically connected to any of the three drive electrodes 13a, 13a, and 13a.

  The second configuration is leg portions 15,..., 15 connected to a part of the ring-shaped vibrating body 11. Since the leg portions 15,..., 15 are formed in the same manner as those in the first embodiment, detailed description in the present embodiment is omitted.

  In the present embodiment, a plurality of lead electrodes 14 are formed on the four leg portions 15,..., 15 out of the 16 leg portions 15,. These were created in order to secure a path for drawing from each electrode arranged in the region from the outer peripheral edge of the ring-shaped vibrating body 11 to the vicinity of the outer peripheral edge to the electrode pad 18 on the support column 19. In particular, in this embodiment, lead electrodes 14 and 14 are formed from both end portions of the second detection electrodes 13d and 13e in order to eliminate the bias of the electric signals from the second detection electrodes 13d and 13e. Even if the extraction electrodes 14 and 14 are formed only from one side of the respective second electrode detections 13d and 13e, the function as a vibrating gyroscope is not lost.

  A third configuration is a support column 19 formed from the silicon substrate 10 connected to the above-described leg portions 15,. In the present embodiment, the support column 19 is connected to the package portion of the ring-shaped vibrating gyroscope 1000 (not shown) and serves as a fixed end. The support column 19 includes electrode pads 18,. As shown in FIG. 22, on the upper surface of the support column 19, the above-described silicon oxide film 20 continuous with those on the leg portions 15,. A metal film 30 and a piezoelectric film 40 are formed. Here, the lower metal film 30 formed on the silicon oxide film 20 serves as the fixed potential electrode 16. Further, on the upper surface of the piezoelectric film 40 formed above the support column 19, the above-described lead electrodes 14,..., 14 and the electrode pads 18 that are continuous with those on the leg portions 15,. ..., 18 are formed.

  Next, the operation of each electrode provided in the ring-shaped vibrating gyroscope 1000 will be described. As described above, in the present embodiment, the primary vibration of the in-plane cos 2θ vibration mode is excited. Since the fixed potential electrode 16 is grounded, the lower electrode film 30 formed continuously with the fixed potential electrode 16 is uniformly at 0V.

First, as shown in FIG. 21, an AC voltage of 1 V _P-0 is applied to the three drive electrodes 13a, 13a, 13a. As a result, the piezoelectric film 40 expands and contracts to excite primary vibration. Here, in this embodiment, since the upper metal film 50 is formed outside the center line on the upper surface of the ring-shaped vibrating body 11, the piezoelectric film 40 is not formed on the side surface of the ring-shaped vibrating body 11. The expansion and contraction motion can be converted into the primary vibration of the ring-shaped vibrating body 11.

  Here, in this embodiment, three groups of drive electrodes arranged at an angle of 90 ° in the circumferential direction are arranged to excite the primary vibration of the ring-shaped vibrating body 1000 in the cos 2θ vibration mode. As compared with a group of drive electrodes arranged only at an angle of 180 ° in the circumferential direction, an increase in amplitude or power saving is achieved. If a more general expression is used, the ring-shaped vibrating body 1000 of the present embodiment that excites the primary vibration in the vibration mode of cosNθ includes a drive electrode disposed at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes. Accordingly, an increase in amplitude or power saving is achieved as compared with a group of drive electrodes arranged only at an angle (360 / N) ° in the circumferential direction.

  Next, the monitor electrode 13h shown in FIG. 21 detects the amplitude and resonance frequency of the primary vibration described above, and transmits a signal to a known feedback control circuit (not shown). The feedback control circuit of the present embodiment controls the frequency of the AC voltage applied to the drive electrodes 13a, 13a, and 13a so that the natural frequency of the ring-shaped vibrating body 11 coincides with the amplitude of the ring-shaped vibrating body 11. Control is performed using the signal of the monitor electrode 13h so as to have a certain value. As a result, the ring-shaped vibrating body 11 maintains constant vibration.

  When an angular velocity is applied around the vertical axis (Z axis) after the above-described primary vibration is excited, in this embodiment, which is an in-plane cos 2θ vibration mode, the vibration of the primary vibration shown in FIG. 28A is caused by the Coriolis force. The secondary vibration shown in FIG. 28B occurs with a new vibration axis inclined at 45 ° on both sides with respect to the axis.

  This secondary vibration is detected by the two detection electrodes (third detection electrodes) 13f and 13f and the other two detection electrodes (third detection electrodes) 13g and 13g. In the present embodiment, as shown in FIG. 21, the detection electrodes 13f and 13g are arranged corresponding to the vibration axes of in-plane secondary vibration, respectively. The detection electrodes 13 f and 13 g described above are formed on the inner side of the center line on the upper surface of the ring-shaped vibrating body 11. Therefore, as already described in the explanation of FIG. 9, the positive and negative of the electrical signals of the detection electrodes 13f and 13g generated by the in-plane secondary vibration excited by the angular velocity are reversed.

  Here, in an arithmetic circuit which is a known difference circuit, the difference between the electrical signals of the third detection electrodes 13f and 13g is calculated. As a result, the detection signal has about twice the detection capability as compared with the case of either one of the detection electrodes.

  Next, a case where an angular velocity is applied around the X axis after the above-described primary vibration is excited will be described. In this case, the secondary vibration of the vibration mode of cos 3θ shown in FIG. 28C is generated.

  This secondary vibration is detected by three detection electrodes (first detection electrodes) 13b, 13b, 13b and another three detection electrodes (first detection electrodes) 13c, 13c, 13c. In the present embodiment, as shown in FIG. 21, the detection electrodes 13b and 13c are arranged corresponding to the vibration axis of the secondary vibration in the cos 3θ mode of the out-of-plane. In the present embodiment, the detection electrodes 13b and 13c described above are formed on the outer side or the inner side of the center line on the upper surface of the ring-shaped vibrating body 11, but the present embodiment is not limited to this. Absent. Rather, it is preferable that each of the detection electrodes 13b and 13c described above is disposed so as to include a center line in which the distortion of the piezoelectric film is least likely to occur due to the in-plane primary vibration or the secondary vibration corresponding to the Z axis. It is one mode. In that sense, it can be said that the arrangement of the first detection electrodes 13b, 13b, and 13b like the ring-shaped vibrating gyroscope 1900 shown in FIG. In FIG. 33, for convenience of explanation, the configuration other than the ring-shaped vibrating body 11 is not drawn. In addition, the arrangement of the detection electrodes 13b and 13c of the present embodiment reverses the positive and negative of the electrical signals of the detection electrodes 13b and 13c caused by the out-of-plane secondary vibration excited by the angular velocity. .

  Therefore, in the same manner as described above, the difference between the electrical signals of the detection electrodes 13b and 13c is calculated in an arithmetic circuit that is a known difference circuit. As a result, the detection signal has about twice the detection capability as compared with the case of either one of the detection electrodes.

  Next, a case where an angular velocity is applied around the Y axis after the above-described primary vibration is excited will be described. In this case, the secondary vibration in the vibration mode of cos 3θ shown in FIG. 28D is generated. This secondary vibration is another out-of-plane cos 3θ mode in which the vibration axis angle is 30 ° apart from the cos 3θ vibration mode shown in FIG. 28C.

  This secondary vibration is detected by the three detection electrodes (second detection electrodes) 13d, 13d, and 13d and the other three detection electrodes (second detection electrodes) 13e, 13e, and 13e. In the present embodiment, as shown in FIG. 21, each of the detection electrodes 13d and 13e is arranged corresponding to the vibration axis of the out-of-plane secondary vibration. In the present embodiment, the detection electrodes 13d and 13e described above are formed outside the center line on the upper surface of the ring-shaped vibrating body 11, but the present embodiment is not limited to this. Rather, it is preferable that each of the detection electrodes 13d and 13e described above is disposed so as to include a center line in which the piezoelectric film is most unlikely to be distorted by the in-plane primary vibration or the secondary vibration corresponding to the Z axis. It is one mode. In that sense, like the first detection electrodes 13b, 13b, and 13b, the arrangement of the second electrodes 13d, 13d, and 13d such as the ring-shaped vibrating gyroscope 1900 shown in FIG. 33 is a preferable embodiment. Further, in the arrangement of the detection electrodes 13d and 13e of the present embodiment, the positive and negative of the electrical signals of the detection electrodes 13d and 13e generated by the out-of-plane secondary vibration excited by the angular velocity is reversed. .

  Therefore, in the same manner as described above, the difference between the electrical signals of the detection electrodes 13d and 13e is calculated in an arithmetic circuit that is a known difference circuit. As a result, the detection signal has about twice the detection capability as compared with the case of either one of the detection electrodes.

  By the way, in the above-mentioned thirteenth embodiment, for convenience, the names of the first detection electrode to the third detection electrode are given to the detection electrodes that detect each of the three axes that are targets for detecting the angular velocity. As the name of the detection electrode for the axis, any one non-overlapping name among the first detection electrode to the third detection electrode may be given.

  Further, since the ring-shaped vibration gyro 1900 shown in FIG. 33 includes six drive electrodes 13a,..., 13a, compared with the ring-shaped vibration gyro 1000 of the thirteenth embodiment, Further increase in amplitude or further power saving is achieved. Further, if the positional objectivity of the monitor electrodes 13h and 13h is not taken into consideration, it is possible to replace one of the two monitor electrodes 13h and 13h with a drive electrode, or to further increase the amplitude of the primary vibration or This leads to further power saving.

<Modification (1) of the thirteenth embodiment>
FIG. 23 is a front view of a structure that plays a central role in a ring-shaped vibrating gyroscope 1100 obtained by modifying a part of the first embodiment.

  The ring-shaped vibrating gyroscope 1100 of the present embodiment includes an arrangement of the upper metal film 50 of the first configuration in the thirteenth embodiment, an arrangement of the extraction electrodes 14 on some leg portions 15,. Except for the arrangement of some electrode pads 18,..., 18, the same configuration as the ring-shaped vibrating gyroscope 1000 of the first embodiment is provided. The manufacturing method is the same as that of the thirteenth embodiment except for a part. Furthermore, the vibration mode of the primary vibration and the vibration mode of the secondary vibration in this embodiment are the same vibration modes as those in the thirteenth embodiment. Therefore, the description which overlaps with 13th Embodiment is abbreviate | omitted.

  As shown in FIG. 23, in the ring-shaped vibrating gyroscope 1100 of this embodiment, the detection electrodes 13b, 13d, and 13g are arranged one by one. Even with such an arrangement of the detection electrodes, the effect of the present invention is substantially achieved. That is, the presence of each of the detection electrodes 13b, 13d, and 13g allows detection of angular velocity using an out-of-plane vibration mode of three axes, that is, two axes (X axis and Y axis) and one axis (Z It is possible to detect the angular velocity using the in-plane vibration mode of the (axis). In the present embodiment, the difference circuit employed in the thirteenth embodiment is not necessary, so that the circuit can be simplified. On the other hand, since there is only one detection electrode 13b, 13d, 13g having the same electrode area as that of the thirteenth embodiment, the detection capability is inferior to that of the thirteenth embodiment.

  Further, in the present embodiment, since each electrode is unevenly distributed, there is a leg portion 15 where the extraction electrode 14 is not formed, but the present embodiment is not limited to this. For example, even if the leg portion 15 where the extraction electrode 14 is not formed is eliminated, the same effect as that of the present embodiment is achieved. However, since the absence of the disordered leg portions 15 may hinder the uniform vibration of the ring-shaped vibrating body 11, a structure in which only the leg portions 15 located at positions allocated so as to be separated by a uniform angle are eliminated.

<Modification (2) of the thirteenth embodiment>
FIG. 24 is a front view of a structure that plays a central role in a ring-shaped vibrating gyroscope 1200 obtained by modifying a part of the thirteenth embodiment.

  The ring-shaped vibrating gyroscope 1200 of the present embodiment includes an arrangement of the upper metal film 50 of the first configuration in the thirteenth embodiment, an arrangement of the extraction electrodes 14 on some leg portions 15,. Except for the arrangement of some of the electrode pads 18,..., 18, the same configuration as the ring-shaped vibrating gyroscope 1000 of the thirteenth embodiment is provided. The manufacturing method is the same as that of the thirteenth embodiment except for a part. Furthermore, the vibration mode of the primary vibration and the vibration mode of the secondary vibration in this embodiment are the same vibration modes as those in the thirteenth embodiment. Therefore, the description which overlaps with 13th Embodiment is abbreviate | omitted.

  As shown in FIG. 24, in the ring-shaped vibrating gyroscope 1200 of this embodiment, each detection electrode 13b, 13c, 13d, 13e, 13g is arranged one by one. Further, as shown in FIG. 24, the first detection electrodes 13b and 13c extend to a range where the electrode region exceeds the center line. Even with such an arrangement of the detection electrodes, the effect of the present invention is substantially achieved. That is, the presence of each of the detection electrodes 13b, 13c, 13d, 13e, and 13g allows detection of angular velocity using a 3-axis, that is, 2-axis (X-axis and Y-axis) out-of-plane vibration mode, and Angular velocity can be detected using a single-axis (Z-axis) in-plane vibration mode. In particular, it is preferable that the first detection electrodes 13b and 13c are arranged so as to include a center line that is most unlikely to cause distortion of the piezoelectric film due to primary vibration or secondary vibration that is an in-plane vibration mode. It is. Further, the first detection electrodes 13b and 13c are arranged in a symmetric shape with respect to the center line because in the in-plane vibration mode, the direction of distortion is reversed with respect to the center line. It is a more preferable embodiment.

  Further, even if the plurality of first detection electrodes 13b and 13c are not arranged so as to be symmetric with respect to the center line, the first in which the in-plane vibration mode is difficult to detect according to the vibration mode to be employed. There are various arrangements of the detection electrodes 13b and 13c. Therefore, as described above, the second electrode arrangement region in which the detection electrodes 13b, 13c, 13d, and 13e are arranged is defined as a region on the upper surface of the ring-shaped vibrating body 11 that is not in electrical contact with the first electrode arrangement region. Is done.

  In addition, in this embodiment, since the electrode area of the 1st detection electrode 13b, 13c single-piece | unit has increased compared with those of 13th Embodiment, the modification (2) of 13th Embodiment mentioned above and In comparison, the detection capability is improved. However, it is preferable that they are arranged symmetrically with respect to the vibration axis. In the present embodiment, the electrode area of only the first detection electrodes 13b and 13c is increased, but the present embodiment is not limited to this. For example, it is a preferable aspect that the drive capability or the detection capability is improved by increasing the number and area of the drive electrodes, the area of the monitor electrodes, or the area of other detection electrodes. In particular, in this embodiment, three groups of drive electrodes arranged at an angle of 90 ° in the circumferential direction that excite the primary vibration of the ring-shaped vibrating body 1000 in the vibration mode of cos 2θ are disposed. As compared with a group of drive electrodes arranged only at an angle of 180 ° in the circumferential direction, an increase in amplitude or power saving is achieved.

  Further, in the present embodiment, since each electrode is unevenly distributed, there is a leg portion 15 where the extraction electrode 14 is not formed, but the present embodiment is not limited to this. For example, even if the leg portion 15 where the extraction electrode 14 is not formed is eliminated, the same effect as that of the present embodiment is achieved. However, since the absence of the disordered leg portions 15 may hinder the uniform vibration of the ring-shaped vibrating body 11, a structure in which only the leg portions 15 located at positions allocated so as to be separated by a uniform angle are eliminated.

<Modification (13) of the thirteenth embodiment>
FIG. 25 is a cross-sectional view corresponding to FIG. 22 of a structure that plays a central role in a ring-shaped vibrating gyroscope 1300 obtained by modifying a part of the thirteenth embodiment.

  In the present embodiment, as shown in FIG. 25, the piezoelectric film 40 is etched in accordance with a region where the upper metal film 50 is substantially formed. For this reason, the AC voltage applied to the upper metal film 50 is applied only vertically downward without being affected by the region where the lower metal film 30 is formed. Transmission is prevented. In the present embodiment, after the dry etching process of the upper metal film 50, the remaining resist film on the upper metal film 50 or the metal film 50 itself is used as an etching mask, and then the dry etching is performed under the same conditions as in the thirteenth embodiment. By performing the etching, the above-described piezoelectric film 40 is formed. Further, as shown in FIG. 25, in this embodiment, the piezoelectric film 40 is etched in an inclined shape (for example, an inclination angle is 75 °). However, in the present application, the piezoelectric film 40 having a steep inclination as shown in FIG. 25 is not substantially visible in the plan view of the ring-shaped vibrating gyroscope 200 shown in FIG. Handled. In addition, the aspect in which the piezoelectric film 40 disclosed in this embodiment is etched can be applied to at least all the embodiments of the present application.

<Modification (4) of the thirteenth embodiment>
In the thirteenth embodiment and the modifications (1) to (3) described above, the structure of a vibrating gyroscope capable of detecting a triaxial angular velocity is described, but for detecting a biaxial or uniaxial angular velocity. The arrangement of each detection electrode is also derived from the thirteenth embodiment.

  For example, among the first to third detection electrodes 13b, 13c, 13d, 13e, 13f, and 13g, the first detection electrodes 13b and 13c for measuring the X-axis angular velocity and the second detection electrode for measuring the angular velocity of the Y-axis. By arranging only 13d and 13e on the ring-shaped vibrating body 11, a vibrating gyroscope that detects a biaxial angular velocity is manufactured. That is, by selecting the detection electrodes corresponding to the two axes among the first to third detection electrodes, it is possible to obtain a vibrating gyroscope that detects the angular velocity of the two axes. For example, it has already been described that the effect of the present invention can be substantially achieved by arranging only one first detection electrode (for example, 13b) among the first detection electrodes 13b and 13c. It is as follows.

  The same idea as described above is also applied to the structure of a vibrating gyroscope that can detect a uniaxial angular velocity. For example, among the first to third detection electrodes 13b, 13c, 13d, 13e, 13f, and 13g, only the first detection electrodes 13b and 13c for measuring the angular velocity of the X axis are arranged on the ring-shaped vibrating body 11. Thus, a vibrating gyroscope that detects the angular velocity of one axis is manufactured. The vibration gyro for detecting the uniaxial angular velocity also has a biaxial angular velocity by selecting a detection electrode corresponding to any one of the three axes (X axis, Y axis, Z axis). A vibration gyro to be detected can be obtained. For example, it has already been described that the effect of the present invention can be substantially achieved by arranging only one first detection electrode (for example, 13b) among the first detection electrodes 13b and 13c. It is as follows.

<Modification (13) of the thirteenth embodiment>
FIG. 26 is a front view of a structure that plays a central role in a ring-shaped vibrating gyroscope 1400 obtained by modifying a part of the thirteenth embodiment. FIG. 27 is a cross-sectional view taken along line FF in FIG.

  In the ring-shaped vibrating gyroscope 1400 of this embodiment, a fixed end 60 is formed around the ring-shaped vibrating body 11 via a groove or leg portion 17 as compared with the thirteenth embodiment. On the leg portion 17 and the fixed end 60, the extraction electrode 14 and the electrode pad 18 starting from the drive electrodes 13a and 13a and the second detection electrodes 13d and 13e are formed. Further, since the lead electrode 14 on the leg portion 17 is formed, the lead electrode 14 and the electrode pad 18 on the leg portion 15 and the fixed end 19 are removed. The ring-shaped vibrating gyroscope 1400 of this embodiment has the same configuration as that of the thirteenth embodiment except for the points described above. The manufacturing method is the same as that of the thirteenth embodiment except for a part. Furthermore, the vibration mode of the primary vibration and the vibration mode of the secondary vibration in this embodiment are the same vibration modes as those in the thirteenth embodiment. Therefore, the description which overlaps with 13th Embodiment is abbreviate | omitted. In the present embodiment, in order to make the drawing easier to see, the AC power source connected to the drive electrodes 13a and 13a is not shown.

  In the ring-shaped vibrating gyroscope 1400 of the present embodiment, the fixed end 60 and the leg portion 17 that connects the fixed end 60 and the ring-shaped vibrating body 11 are formed, so that a plurality of lead electrodes are formed on the leg portion 15 inside the ring-shaped vibrating body 11. 14 need not be arranged. Therefore, the risk of a short circuit between the extraction electrodes due to defects in the manufacturing process is greatly reduced. As shown in FIG. 26, since the extraction electrode 14 is joined to the center of the width of each electrode, the bias of the electric signals from the drive electrodes 13a and 13a and the second detection electrodes 13d and 13e in the thirteenth embodiment is Does not occur. On the other hand, the formation of the fixed end 60 increases the size of the vibration gyro as compared with that of the thirteenth embodiment.

<Fourteenth embodiment>
FIG. 29 is a front view of a structure that plays a central role in a ring-shaped vibrating gyroscope 1500 that measures another three-axis angular velocity in the present embodiment.

  The ring-shaped vibrating gyroscope 1500 according to this embodiment includes a drive electrode 13a, a monitor electrode 13h, the first detection electrodes 13b and 13c, the second detection electrodes 13d and 13e, and the third detection electrodes 13f and 13g in the thirteenth embodiment. The arrangement is the same as that of the ring-shaped vibrating gyroscope 1000 of the thirteenth embodiment except for the arrangement of some of the detection electrodes. The manufacturing method is the same as that in the thirteenth embodiment. Therefore, the description which overlaps with 13th Embodiment is abbreviate | omitted. However, the vibration mode of the primary vibration of the present embodiment is the in-plane cos 3θ vibration mode shown in FIG. 30A. Also, the vibration mode of the secondary vibration of the present embodiment includes the X-axis cos 2θ out-of-plane vibration mode shown in FIG. 30B and the Y-axis cos 2θ out-of-plane vibration shown in FIG. 30C. FIG. 30D is a one-axis (Z-axis) cos 3θ in-plane vibration mode shown in FIG. 30D.

  As shown in FIG. 29, also in the ring-shaped vibrating gyroscope 60 of this embodiment, the outer end portion of the upper metal film 50 constituting the plurality of electrodes 13a to 13h has a ring-shaped vibrating body 11 having a ring-shaped plane having a width of about 40 μm. It is formed about 1 μm inward from the outer peripheral edge, and its width is about 18 μm. The upper metal film 50 is formed outside or inside the center line.

  By the way, in this embodiment, the primary vibration of the ring-shaped vibration gyroscope 1500 is excited in the in-plane cos 3θ vibration mode. Moreover, the vibration mode of the secondary vibration of this embodiment is a vibration mode shown in FIGS. 30B to 30D. Therefore, the breakdown of the plurality of electrodes 13a to 13h is as follows. First, four drive electrodes 13a,..., 13a arranged at an angle of 120 ° in the circumferential direction are arranged. Further, when one of the four drive electrodes 13a,..., 13a is used as a reference electrode (for example, the drive electrode 13a in the 12 o'clock direction in FIG. 29), the drive electrode Two monitor electrodes 13h and 13h are arranged at angles of 120 ° and 300 ° in the circumferential direction from 13a. Further, when an angular velocity around the X axis is given to the ring-shaped vibrating gyroscope 1500 when the plane on which the piezoelectric element on the ring-shaped vibrating body is arranged, in other words, the paper plane in FIG. 29 is the XY plane. The first detection electrodes 13b and 13c that detect secondary vibrations generated at the same position are arranged in the circumferential direction from the reference electrode at angles of 0 °, 90 °, 180 °, and 270 °. Similarly, the second detection electrodes 13d and 13e for detecting secondary vibration generated when an angular velocity around the Y axis is applied to the ring-shaped vibration gyroscope 1500 are 45 °, 135 ° in the circumferential direction from the reference electrode. It is arranged at an angle of 225 ° and 315 ° apart. Furthermore, the ring-shaped vibrating gyroscope 1500 has a Z-axis, that is, an axis perpendicular to the plane on which the ring-shaped vibrating gyroscope 1500 shown in FIG. Third detection electrodes 13f and 13g for detecting secondary vibration generated when an angular velocity around the axis) is also provided. Note that the third detection electrodes 13f and 13g of the present embodiment are arranged at angles away from the reference electrode by 30 °, 90 °, 150 °, 210 °, 270 °, and 330 ° in the circumferential direction.

  Next, the operation of each electrode provided in the ring-shaped vibrating gyroscope 1500 will be described. As described above, in this embodiment, the primary vibration of the in-plane cos 3θ vibration mode is excited. Since the fixed potential electrode 16 is grounded, the lower electrode film 30 formed continuously with the fixed potential electrode 16 is uniformly at 0V.

First, an AC voltage of 1 V _P-0 is applied to the four drive electrodes 13a,. As a result, the piezoelectric film 40 expands and contracts to excite primary vibration. Here, in this embodiment, since the upper metal film 50 is formed outside the center line on the upper surface of the ring-shaped vibrating body 11, the piezoelectric film 40 is not formed on the side surface of the ring-shaped vibrating body 11. The expansion and contraction motion can be converted into the primary vibration of the ring-shaped vibrating body 11. However, when the driving electrode 13a in the 12 o'clock direction of the timepiece in FIG. 29 is used as a reference electrode, the reference electrode and one reference electrode arranged at an angle of 240 ° in the clockwise circumferential direction from the reference electrode. The phase of the voltage applied to the drive electrode 13a is opposite to the phase of the voltage applied to the other two drive electrodes 13a, 13a.

  Next, the monitor electrodes 13h and 13h shown in FIG. 29 detect the amplitude and resonance frequency of the primary vibration described above, and transmit a signal to a known feedback control circuit (not shown). The feedback control circuit of the present embodiment controls the frequency of the alternating voltage applied to the drive electrodes 13a,..., 13a and the natural frequency of the ring-shaped vibrating body 11 to coincide with each other. Is controlled using the signals of the monitor electrodes 13h and 13h so that the amplitude of becomes a certain value. As a result, the ring-shaped vibrating body 11 maintains constant vibration.

  When the angular velocity is applied around the vertical axis (Z axis) after the above-described primary vibration is excited, in this embodiment, which is an in-plane cos 3θ vibration mode, the vibration of the primary vibration shown in FIG. The secondary vibration shown in FIG. 30D occurs with a new vibration axis tilted 30 ° on either side with respect to the axis.

  This secondary vibration is detected by the three detection electrodes (third detection electrodes) 13f, 13f, 13f and another three detection electrodes (third detection electrodes) 13g, 13g, 13g. Also in the present embodiment, as in the thirteenth embodiment, the difference between the electrical signals of the third detection electrodes 13f and 13g is calculated in an arithmetic circuit that is a known difference circuit. As a result, the detection signal has about twice the detection capability as compared with the case of either one of the detection electrodes.

  Next, a case where an angular velocity is applied around the X axis after the above-described primary vibration is excited will be described. In this case, the secondary vibration in the vibration mode of cos 2θ of out-of-plane shown in FIG. 30B occurs.

  This secondary vibration is detected by the two detection electrodes (first detection electrodes) 13b and 13b and the other two detection electrodes (first detection electrodes) 13c and 13c. In this embodiment, as shown in FIG. 29, each of the detection electrodes 13b and 13c is arranged corresponding to the vibration axis of the secondary vibration of the out-of-plane. In the present embodiment, the detection electrodes 13b and 13c described above are formed on the inner side of the center line on the upper surface of the ring-shaped vibrating body 11, but the present embodiment is not limited to this. Rather, it is preferable that each of the detection electrodes 13b and 13c described above is disposed so as to include a center line in which the distortion of the piezoelectric film is least likely to occur due to the primary vibration or the secondary vibration that is an in-plane vibration mode. It is an aspect. Further, the detection electrodes 13b and 13c described above are arranged so as to have a symmetrical shape with respect to the center line because the direction of distortion is reversed with respect to the center line in the in-plane vibration mode. Is a more preferable embodiment.

  The arrangement of the detection electrodes 13b and 13c of the present embodiment reverses the sign of the electrical signals of the detection electrodes 13b and 13c generated by the out-of-plane secondary vibration excited by the angular velocity. Therefore, as in the thirteenth embodiment, the difference between the electrical signals of the detection electrodes 13b and 13c is calculated in an arithmetic circuit that is a known difference circuit. As a result, the detection signal has about twice the detection capability as compared with the case of either one of the detection electrodes.

  Next, a case where an angular velocity is applied around the Y axis after the above-described primary vibration is excited will be described. In this case, the secondary vibration of the vibration mode of cos 2θ shown in FIG. 30C has a vibration axis whose angle is 45 ° apart from the vibration mode of cos 2θ described above.

  This secondary vibration is detected by the two detection electrodes (second detection electrodes) 13d and 13d and the other two detection electrodes (second detection electrodes) 13e and 13e. In the present embodiment, the detection electrodes 13d and 13e are respectively arranged corresponding to the vibration axes of the out-of-plane secondary vibration. In the present embodiment, the detection electrodes 13d and 13e described above are formed on the inner side of the center line on the upper surface of the ring-shaped vibrating body 11, but the present embodiment is not limited to this. Rather, it is preferable that each of the detection electrodes 13d and 13e described above is disposed so as to include a center line in which the distortion of the piezoelectric film is least likely to occur due to the primary vibration or the secondary vibration that is an in-plane vibration mode. It is an aspect. Further, in the in-plane vibration mode, the direction of distortion is reversed with respect to the center line, and therefore, it is more preferable that the in-plane vibration modes are arranged so as to be symmetrical with respect to the center line.

  The arrangement of the detection electrodes 13d and 13e of the present embodiment reverses the sign of the electrical signals of the detection electrodes 13d and 13e generated by the secondary vibration of the out-of-plane excited by the angular velocity. Therefore, in the same manner as described above, the difference between the electrical signals of the detection electrodes 13d and 13e is calculated in an arithmetic circuit that is a known difference circuit. As a result, the detection signal has about twice the detection capability as compared with the case of either one of the detection electrodes.

  In the above-described fourteenth embodiment, for convenience, the names of the first detection electrode to the third detection electrode are given to the detection electrodes that detect each of the three axes that are targets for detecting the angular velocity. As the name of the detection electrode for the axis, any one non-overlapping name among the first detection electrode to the third detection electrode may be given.

  Incidentally, in the thirteenth embodiment and the modifications (1) to (5) described above, the monitor electrodes 13h and 13h are arranged in the same position or region, but the present invention is not limited to this. Absent. That is, the monitor electrode 13h is a case where N is a natural number of 2 or more, or 3 or more, and one of the drive electrodes 13a is used as a reference drive electrode, and M = 0, 1,. (Hereinafter, the same in this paragraph) is necessarily arranged at an angle of [(360 / N) × {M + (1/2)}] ° in the circumferential direction from the reference drive electrode 13a. There is no need. For example, in the case of the vibration mode of cosNθ, where L = 0, 1,..., 2N−1 (hereinafter the same in this paragraph), each monitor electrode 13h is connected to the reference drive electrode by Arrangement is made so as to avoid an arrangement at an angle other than (180 / N) × {L + (1/2)} ° apart in the circumferential direction, or an arrangement that is axisymmetric with respect to the position of the angle. In addition, each monitor electrode 13h is arranged so as to avoid an arrangement that is symmetric with respect to the center line. By arranging each monitor electrode 13h in such a manner, the effect of the thirteenth embodiment or its modification is substantially achieved.

  A specific example of the above is a ring-shaped vibrating gyroscope 1600 shown in FIG. 31A. The monitor electrodes 13h and 13h of the ring-shaped vibrating gyroscope 1600 are cases where N is a natural number greater than or equal to 2 or 3, and one of the drive electrodes 13a is a reference drive electrode and M = 0, 1,. .., N-1 (hereinafter the same in this paragraph), it is not necessarily [(360 / N) × {M + (1/2)}] degrees away from the reference drive electrode 13a in the circumferential direction Is not arranged at an angle. However, even with the arrangement of the monitor electrodes 13h and 13h shown in FIG. 12A, the same effect as that of the thirteenth embodiment is exhibited.

  Note that the two monitor electrodes 13h and 13h of the ring-shaped vibrating gyroscope 1600 shown in FIG. 31A are two drive electrodes 13a and 13a arranged at point-symmetrical positions in the front view among the drive electrodes 13a, 13a and 13a. Centered at an angle of 90 ° in the circumferential direction from each other, they are arranged at an angle separated by an equal angle clockwise and counterclockwise. With this arrangement, electrical signals due to secondary vibrations that are not to be detected cancel each other. Therefore, detection of the amplitude and resonance frequency of the primary vibration of the ring-shaped vibrating body 11 that is the original role of the monitor electrodes 13h and 13h. Accuracy is improved.

  Another example is a ring-shaped vibrating gyroscope 1700 shown in FIG. 31B. The two monitor electrodes 13 h and 13 h of the ring-shaped vibrating gyroscope 780 are disposed on a region from the inner peripheral edge of the ring-shaped vibrating body 11 to the center line. On the other hand, the electrode area of the second detection electrode 13d is reduced. However, even with the arrangement of the monitor electrodes 13h and 13h shown in FIG. 31B, at least some of the effects of the thirteenth embodiment can be achieved. In addition, some or all of the monitor electrodes 13h and 13h are arranged on a region from the outer peripheral edge of the ring-shaped vibrating body 11 to the center line so as to avoid an arrangement that is symmetric with respect to the center line. Thus, at least some of the effects of the thirteenth embodiment are achieved.

  As shown in the above examples, the degree of freedom of arrangement of the monitor electrodes on or above the plane of the ring-shaped vibrating body 11 is high. However, for example, in the thirteenth and subsequent embodiments, when the vibration mode is cosNθ and L = 0, 1,..., 2N−1 (hereinafter the same in this paragraph). Further, each monitor electrode 13h is symmetrical with respect to the arrangement of the angle other than (180 / N) × {L + (1/2)} ° in the circumferential direction from the reference drive electrode, or the position of the angle. Arranged to avoid such an arrangement. The reason for the former is that the distortion of the ring-shaped vibrator 11 becomes zero (0) when arranged at that position. Moreover, the latter reason is because the distortion directions are opposite to each other, so that the distortions are offset. In addition, each monitor electrode 13h is arranged so as to avoid an arrangement that is symmetric with respect to the center line. This is also because the distortion directions are opposite to each other, so that the distortions are offset. In particular, in the limited planar area of the ring-shaped vibrating body 11 that is miniaturized, the arrangement of the monitor electrode 13h as shown in the thirteenth embodiment is different from the arrangement of other electrode groups and / or the extraction electrode. Will be easier to arrange. Specifically, the monitor electrode 13h is a case where N is a natural number greater than or equal to 2 or 3, and one of the drive electrodes 13a is a reference drive electrode, and M = 0, 1,. In the case of N-1 (hereinafter the same in this paragraph), it is arranged at an angle of [(360 / N) × {M + (1/2)}] ° in the circumferential direction from the reference drive electrode 13a. This is a preferable embodiment.

<Other variations>
In the fourteenth embodiment, modifications similar to the modifications of the thirteenth embodiment described above can be applied. Therefore, the advantageous effect by each structure is show | played.

  By the way, in each embodiment after the thirteenth embodiment described above, a vibration gyro using an annular vibrating body has been described, but in each embodiment after the thirteenth embodiment, instead of the annular shape, A polygonal vibrator may be employed. For example, even with a regular polygonal vibrator such as a regular hexagon, a regular octagon, a regular dodecagon, and a regular icosahedron, substantially the same effect as the effect of the present invention is exhibited. Further, a vibrating body such as a dodecagonal vibrating body 211 of a ring-shaped vibrating gyroscope 1800 shown in FIG. 32 may be used. If a polygonal vibrating body having a point-symmetric shape in the front view of the vibrating body is employed, it is preferable from the viewpoint of stability during vibration of the vibrating body. The “annular shape” includes an elliptical shape. Further, in FIG. 32, unlike FIG. 21 and the like, the leg portion and the support column are not shown in order to make the drawing easy to see.

  In the embodiments other than the above-described second embodiment and the modification (3) of the thirteenth embodiment, each electrode is formed by patterning the upper metal film 50 without etching the piezoelectric film 40. However, the present invention is not limited to this. Also in the embodiments other than the modification (3) of the second embodiment and the thirteenth embodiment, the piezoelectric film 40 is etched in accordance with the region where the upper metal film 50 is substantially formed. Undesirable expansion and contraction of the piezoelectric film 40 and the transmission of electrical signals are prevented.

  In each of the above-described embodiments, a silicon oxide film is employed as the insulating film on the silicon substrate, but the present invention is not limited to this. For example, even if a silicon nitride film or a silicon oxynitride film is formed instead of the silicon oxide film, substantially the same effect as the effect of the present invention is achieved.

  In each of the above-described embodiments, each electrode is formed by patterning the upper metal film, but the present invention is not limited to this. For example, even if each electrode is formed by patterning only the lower metal film or both the upper metal film and the lower metal film, the same effect as that of the present invention can be obtained. However, considering the ease of manufacturing, it is a preferable aspect that only the upper metal film is patterned as in the above-described embodiments.

  In addition, in the embodiments other than the tenth to twelfth embodiments described above, the suppression electrode is not used, but the present invention is not limited to this. By arranging the suppression electrode in all the embodiments, the same effects as the effects of the tenth to twelfth embodiments can be obtained. For example, the vibrating gyroscope 2000 shown in FIG. 34 is one of the modified examples of the fourteenth embodiment. This vibrating gyroscope 2000 is a vibrating gyroscope in which the suppression electrode 13j acts on detection of angular velocity around the vertical axis (Z axis). Accordingly, the arrangement of the electrodes in the tenth to twelfth embodiments in which the suppression electrode is adopted is, for those skilled in the art, an X axis, a Y axis, and a plurality of axes (for example, three axes of X, Y, and Z axes). The arrangement of each electrode of a vibrating gyroscope with a suppression electrode for the detection of the angular velocity around all) is fully disclosed. One specific example is a ring-shaped vibrating gyroscope 2100 in which suppression electrodes act on all three axes of the X, Y, and Z axes as shown in FIG.

  Furthermore, in each of the embodiments described above, a ring-shaped vibrating gyroscope using silicon as a base material is employed, but the present invention is not limited to this. For example, the base material of the vibration gyro may be germanium or silicon germanium. Among the above, in particular, adoption of silicon or silicon germanium can greatly improve the processing accuracy of the entire gyro including the vibrating body because a known anisotropic dry etching technique can be applied. As described above, modifications that exist within the scope of the present invention including other combinations of the embodiments are also included in the scope of the claims.

  The present invention can be applied to a part of various devices as a vibrating gyroscope.

DESCRIPTION OF SYMBOLS 10 Silicon substrate 11, 11a, 11b Ring-shaped vibrating body 12 AC power supply 13a Drive electrode 13b, 13c, 213b, 213c, 313c, 13s, 313s First detection electrode 13d, 13e, 13t, 213t, 313t Second detection electrode 13f, 13g Third detection electrode 13h, 413h, 423h, 513h, 613h, 623h, 713h, 753h Monitor electrode 13j Suppression electrode 14 Lead electrode 15, 95 Leg portion 16 Fixed potential electrode (ground electrode)
Reference Signs List 17 Electrode Pad Fixed End 18 Electrode Pad 19 Support 20 Silicon Oxide Film 30 Lower Metal Film 40 Piezoelectric Film 50 Upper Metal Film 60 Fixed End 61, 62 Feedback Control Circuit 100, 200, 300, 400, 420, 500, 600 , 700, 750, 800, 900, 920, 940, 960, 980, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100 Ring-shaped vibrating gyroscope

Claims (22)

A ring-shaped vibrating body with a uniform plane;
A leg portion that flexibly supports the ring-shaped vibrating body;
A plurality of electrodes placed on or above the plane of the ring-shaped vibrator and formed by at least one of an upper metal film and a lower metal film sandwiching the piezoelectric film in the thickness direction;
The plurality of electrodes are arranged at an angle separated by (360 / N) ° in the circumferential direction to excite the primary vibration of the ring-shaped vibrating body in a vibration mode of cosNθ when N is a natural number of 2 or more. A group of drive electrodes including a plurality of drive electrodes and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes, and clockwise from each of the drive electrodes Or a group of first detection electrodes that are disposed at an angle of (90 / N) ° counterclockwise and that detect secondary vibrations generated when an angular velocity is applied to the ring-shaped vibrating body, A group of second detection electrodes disposed at an angle of (180 / N) ° from the first detection electrodes of the first detection electrodes, and detecting the secondary vibration,
Each of the drive electrodes, each of the first detection electrodes, and each of the second detection electrodes includes a region extending from an outer peripheral edge of the ring-shaped vibrating body to a vicinity of the outer peripheral edge, and the ring-shaped vibrating body. The vibrating gyroscope is disposed in one or both of the region from the inner peripheral edge to the vicinity of the inner peripheral edge. The plurality of electrodes further include a monitor electrode disposed at an angle (180 / N) ° away from at least one of the drive electrodes;
Either the area from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge and the area from the inner peripheral edge of the ring-shaped vibrating body to the vicinity of the inner peripheral edge, or The vibrating gyroscope according to claim 1, wherein the vibrating gyroscope is disposed in both regions. The plurality of electrodes may exclude {(180 / N) − (45 / N)} ° from {(180 / N) + (45), excluding an angle (180 / N) ° away from at least one of the drive electrodes. / N)} further including monitor electrodes disposed in the region up to
Either the area from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge and the area from the inner peripheral edge of the ring-shaped vibrating body to the vicinity of the inner peripheral edge, or The vibrating gyroscope according to claim 1, wherein the vibrating gyroscope is disposed in both regions. All the first detection electrodes and all the second detection electrodes are in a region from the outer periphery of the ring-shaped vibrating body to the vicinity of the outer periphery or from the inner periphery to the vicinity of the inner periphery. Placed in only one of the areas,
The vibration gyro according to claim 1, wherein a difference between signals output from the first detection electrodes and the second detection electrodes is calculated by an arithmetic circuit. All the first detection electrodes and all the second detection electrodes are in a region from the outer periphery of the ring-shaped vibrating body to the vicinity of the outer periphery or from the inner periphery to the vicinity of the inner periphery. Are located in different areas of the area,
The sum of signals output from each of the first detection electrodes and each of the second detection electrodes is calculated by connecting an arithmetic circuit or electrodes extracted from the first detection electrode and the second detection electrode. The vibration gyro described. A ring-shaped vibrating body with a uniform plane;
A leg portion that flexibly supports the ring-shaped vibrating body;
A plurality of electrodes placed on or above the plane of the ring-shaped vibrator and formed by at least one of an upper metal film and a lower metal film sandwiching the piezoelectric film in the thickness direction;
The plurality of electrodes are the following (1) and (2), that is,
(1) When N is a natural number equal to or greater than 2, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including an electrode and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes. (2) one of the drive electrodes is a reference drive electrode And S = 0, 1,..., N (hereinafter the same), the secondary vibration of the vibration mode of cos (N + 1) θ generated when an angular velocity is applied to the ring-shaped vibrating body. And {{360 / (N + 1)} × S] ° away from the reference drive electrode and [{360 / (N + 1)} × {S + (1/2)}] from the reference drive electrode At an angle of at least one of Has a group of detection electrodes comprising an electrode,
Each of the drive electrodes may be either a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge or a region from the inner peripheral edge of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Or disposed in the first electrode arrangement region in the plane including both regions,
Each of the detection electrodes is arranged in a second electrode arrangement region in the plane of the ring-shaped vibrating body, and is not electrically connected to any of the drive electrodes. A ring-shaped vibrating body with a uniform plane;
A leg portion that flexibly supports the ring-shaped vibrating body;
A plurality of electrodes placed on or above the plane of the ring-shaped vibrator and formed by at least one of an upper metal film and a lower metal film sandwiching the piezoelectric film in the thickness direction;
The plurality of electrodes are the following (1) and (2), that is,
(1) When N is a natural number equal to or greater than 2, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including an electrode and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes. (2) one of the drive electrodes is a reference drive electrode And S = 0, 1,..., N (hereinafter the same), the secondary vibration of the vibration mode of cos (N + 1) θ generated when an angular velocity is applied to the ring-shaped vibrating body. And {{360 / (N + 1)} × {S + (1/4)}] ° away from the reference drive electrode and [{360 / (N + 1)} × {S +] from the reference drive electrode. (3/4)}] at least one of an angle apart Has a group of detection electrodes comprising electrodes disposed at an angle,
Each of the drive electrodes may be either a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge or a region from the inner peripheral edge of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Or disposed in the first electrode arrangement region in the plane including both regions,
Each of the detection electrodes is arranged in a second electrode arrangement region in the plane of the ring-shaped vibrating body, and is not electrically connected to any of the drive electrodes. A ring-shaped vibrating body with a uniform plane;
A leg portion that flexibly supports the ring-shaped vibrating body;
A plurality of electrodes placed on or above the plane of the ring-shaped vibrator and formed by at least one of an upper metal film and a lower metal film sandwiching the piezoelectric film in the thickness direction;
The plurality of electrodes are the following (1) to (3), that is,
(1) When N is a natural number equal to or greater than 2, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including an electrode and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes. (2) one of the drive electrodes is a reference drive electrode And S = 0, 1,..., N (hereinafter the same), the secondary vibration of the vibration mode of cos (N + 1) θ generated when an angular velocity is applied to the ring-shaped vibrating body. And {{360 / (N + 1)} × S] ° away from the reference drive electrode and [{360 / (N + 1)} × {S + (1/2)}] from the reference drive electrode At an angle of at least one of A group of first detection electrodes each including an electrode; (3) detecting a secondary vibration having a vibration axis at an angle of {90 / (N + 1)} ° with respect to the secondary vibration; 360 / (N + 1)} × {S + (1/4)}] ° apart, and an angle {{360 / (N + 1)} × {S + (3/4)}] ° away from the reference drive electrode, A group of second sensing electrodes comprising electrodes arranged at at least one of the angles,
Each of the drive electrodes may be either a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge or a region from the inner peripheral edge of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Or disposed in the first electrode arrangement region in the plane including both regions,
Each of the first detection electrodes and each of the second detection electrodes is arranged in a second electrode arrangement region in the plane of the ring-shaped vibrating body and is not electrically connected to any of the drive electrodes. A vibrating gyro. When the detection electrode is a first detection electrode, the plurality of electrodes are the following (3):
(3) When M = 0, 1,..., N−1 (hereinafter the same), the secondary vibration of the vibration mode of cosNθ that occurs when an angular velocity is applied to the ring-shaped vibrating body. The angle detected and [(360 / N) × {M + (1/4)}] ° from the reference drive electrode, and [(360 / N)} × {M + (3/4) from the reference drive electrode. )}] Further comprising a group of second detection electrodes comprising electrodes arranged at least one of the angles apart from each other;
The vibrating gyroscope according to claim 6 or 7, wherein each of the second detection electrodes is arranged on the first electrode arrangement region. When the detection electrode is a first detection electrode, the plurality of electrodes are the following (3) and (4), that is,
(3) A secondary vibration having a vibration axis at an angle {90 / (N + 1)} ° away from the secondary vibration is detected, and [{360 / (N + 1)} × {S +] from the reference drive electrode. (1/4)}] ° and at least one of an angle separated from the reference drive electrode by [{360 / (N + 1)} × {S + (3/4)}] °. A group of second detection electrodes each having an electrode disposed thereon (4) When M = 0, 1,..., N-1 (hereinafter the same), an angular velocity is given to the ring-shaped vibrating body The secondary vibration in the vibration mode of cosNθ generated at the angle is detected, and the angle away from the reference drive electrode by [(360 / N) × {M + (1/4)}] ° and the reference drive electrode [( 360 / N)} × {M + (3/4)}] ° at least one of the angles Further comprising a set of third detection electrodes comprising a location has been electrode,
The vibrating gyroscope according to claim 6, wherein each of the second detection electrodes is arranged on the second electrode arrangement region, and each of the third detection electrodes is arranged on the first electrode arrangement region. . A ring-shaped vibrating body with a uniform plane;
A leg portion that flexibly supports the ring-shaped vibrating body;
A plurality of electrodes that are placed on or above or above the plane of the ring-shaped vibrating body and are formed by at least one of an upper metal film and a lower metal film that sandwich the piezoelectric film in the thickness direction. ,
The plurality of electrodes are the following (1) and (2), that is,
(1) When N is a natural number greater than or equal to 3, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including an electrode and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes. (2) one of the drive electrodes is a reference drive electrode And S = 0, 1,..., N-2 (hereinafter the same), the vibration mode of cos (N−1) θ generated when an angular velocity is applied to the ring-shaped vibrating body. And {{360 / (N−1)} × S] ° from the reference driving electrode, and {{360 / (N−1)} × {from the reference driving electrode. S + (1/2)}] arranged at least one of the angles apart It has a group of detection electrodes comprising electrodes,
Each of the drive electrodes may be either a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge or a region from the inner peripheral edge of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Or disposed in the first electrode arrangement region in the plane including both regions,
Each of the detection electrodes is arranged in a second electrode arrangement region in the plane of the ring-shaped vibrating body, and is not electrically connected to any of the drive electrodes. A ring-shaped vibrating body with a uniform plane;
A leg portion that flexibly supports the ring-shaped vibrating body;
A plurality of electrodes placed on or above the plane of the ring-shaped vibrator and formed by at least one of an upper metal film and a lower metal film sandwiching the piezoelectric film in the thickness direction;
The plurality of electrodes are the following (1) and (2), that is,
(1) When N is a natural number greater than or equal to 3, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including an electrode and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes. (2) one of the drive electrodes is a reference drive electrode And S = 0, 1,..., N-2 (hereinafter the same), the vibration mode of cos (N−1) θ generated when an angular velocity is applied to the ring-shaped vibrating body. And {{360 / (N−1)} × {S + (1/4)}] ° away from the reference drive electrode and {{360 / ( N-1)} × {S + (3/4)}] ° apart from at least one of the angles Has a group of detection electrodes comprising electrodes placed Kano angle,
Each of the drive electrodes may be either a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge or a region from the inner peripheral edge of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Or disposed in the first electrode arrangement region in the plane including both regions,
Each of the detection electrodes is arranged in a second electrode arrangement region in the plane of the ring-shaped vibrating body, and is not electrically connected to any of the drive electrodes. A ring-shaped vibrating body with a uniform plane;
A leg portion that flexibly supports the ring-shaped vibrating body;
A plurality of electrodes placed on or above the plane of the ring-shaped vibrator and formed by at least one of an upper metal film and a lower metal film sandwiching the piezoelectric film in the thickness direction;
The plurality of electrodes are the following (1) to (3), that is,
(1) When N is a natural number greater than or equal to 3, the primary vibration of the ring-shaped vibrating body is excited in the vibration mode of cosNθ, and the drive is arranged at an angle separated by (360 / N) ° in the circumferential direction. A group of drive electrodes including an electrode and at least one drive electrode disposed at any angle (180 / N) ° from each of the drive electrodes. (2) one of the drive electrodes is a reference drive electrode And S = 0, 1,..., N-2 (hereinafter the same), the vibration mode of cos (N−1) θ generated when an angular velocity is applied to the ring-shaped vibrating body. And {{360 / (N−1)} × S] ° from the reference driving electrode, and {{360 / (N−1)} × {from the reference driving electrode. S + (1/2)}] arranged at least one of the angles apart A group of first detection electrodes each provided with an electrode (3) detecting a secondary vibration having a vibration axis at an angle of {90 / (N-1)} ° with respect to the secondary vibration, and performing the reference drive [{360 / (N−1)} × {S + (1/4)}] ° away from the electrode and [{360 / (N−1)} × {S + (3/4) from the reference drive electrode. )}] Having a group of second detection electrodes comprising electrodes arranged at at least one of the angles apart from each other;
Each of the drive electrodes may be either a region from the outer peripheral edge of the ring-shaped vibrating body to the vicinity of the outer peripheral edge or a region from the inner peripheral edge of the ring-shaped vibrating body to the vicinity of the inner peripheral edge. Or disposed in the first electrode arrangement region in the plane including both regions,
Each of the first detection electrodes and each of the second detection electrodes is arranged in a second electrode arrangement region in the plane of the ring-shaped vibrating body and is not electrically connected to any of the drive electrodes. A vibrating gyro. When the detection electrode is a first detection electrode, the plurality of electrodes are the following (3):
(3) When M = 0, 1,..., N−1 (hereinafter the same), the secondary vibration of the vibration mode of cosNθ that occurs when an angular velocity is applied to the ring-shaped vibrating body. The angle detected and [(360 / N) × {M + (1/4)}] ° from the reference drive electrode, and [(360 / N)} × {M + (3/4) from the reference drive electrode. )}] Further comprising a group of second detection electrodes comprising electrodes arranged at least one of the angles apart from each other;
The vibrating gyroscope according to claim 11 or 12, wherein each of the second detection electrodes is arranged on the first electrode arrangement region. When the detection electrode is a first detection electrode, the plurality of electrodes are the following (3) and (4), that is,
(3) A secondary vibration having a vibration axis at an angle {90 / (N−1)} ° away from the secondary vibration is detected, and [{360 / (N−1)] from the reference drive electrode. } × {S + (1/4)}] ° and an angle [{360 / (N−1)} × {S + (3/4)}] ° away from the reference drive electrode. A group of second detection electrodes including electrodes arranged at least at any angle (4) When M = 0, 1,..., N−1 (hereinafter the same), Detecting a secondary vibration of a vibration mode of cosNθ generated when an angular velocity is given, and an angle away from the reference drive electrode by [(360 / N) × {M + (1/4)}] °; At least one of the angles [(360 / N)} × {M + (3/4)}] degrees away from the reference drive electrode Further comprising a set of third detection electrodes comprising a location has been electrode,
The vibrating gyroscope according to claim 11, wherein each of the second detection electrodes is arranged on the second electrode arrangement region, and each of the third detection electrodes is arranged on the first electrode arrangement region. . The plurality of electrodes further includes:
(5) When L = 0, 1,..., 2N−1 (hereinafter the same), (180 / N) × {L + (1/2)} ° in the circumferential direction from the reference drive electrode. The vibrating gyroscope according to claim 6, further comprising a monitor electrode disposed at an angle other than the separated angle. The plurality of electrodes further includes:
(5) When M = 0, 1,..., N−1 (hereinafter the same), [(360 / N) × {M + (1 / The vibration gyro according to any one of claims 6 to 15, further comprising: 2)}] monitor electrodes disposed at an angle apart from each other. The vibrating gyroscope according to any one of claims 6 to 15, wherein the second electrode arrangement region includes a center line connecting a center of a width from the outer peripheral edge to the inner peripheral edge. The ring-shaped vibrator is formed of a silicon substrate;
The vibrating gyroscope according to any one of claims 1 to 15, wherein substantially only the upper metal film, the piezoelectric film, and the lower metal film are observed in a front view. The ring-shaped vibrator is formed of a silicon substrate;
The vibrating gyroscope according to any one of claims 1 to 15, wherein substantially only the upper metal film and the lower metal film are observed in a front view. 17. The vibration gyro according to claim 3, wherein a plurality of monitor electrodes are arranged in the vicinity of at least one of the drive electrodes so as to be N times symmetrical in a front view. The plurality of monitor electrodes are arranged in the vicinity of at least one of the drive electrodes at an angle separated by an equal angle clockwise and counterclockwise around the angle at which the one drive electrode is arranged. The vibrating gyroscope according to claim 16.

Images