JP2007163248A - Piezoelectric vibration gyro - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibration gyro having excellent productivity, high performance, low cost, and little deterioration of a characteristic by suppressing generation of an interference noise. <P>SOLUTION: A tuning fork shape is formed by a piezoelectric vibrator 11 and a piezoelectric vibrator 21, and a plurality of piezoelectric vibrators wherein only the shapes of an arm part 11a and an arm part 21a of the tuning fork are different are arranged on mutually orthogonal axes, and the shapes other than the arm parts of the tuning fork are the same so that a mounting fixing method becomes the same. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sensor for detecting acceleration, and in particular, a piezoelectric vibration gyro using a tuning fork-shaped piezoelectric vibrator that is suitable for a gyroscope that is mounted on a camera-integrated VTR, a digital camera, or the like and is used in a system for detecting camera shake. About.

  Piezoelectric vibratory gyros belong to a gyroscope that utilizes a dynamic phenomenon in which, when an angular velocity of rotation is given to a vibrating object, a Coriolis force is generated in a direction perpendicular to the vibration direction. In two directions orthogonal to each other, in a piezoelectric vibrator that allows one to vibrate as an excitation unit and the other as a detection unit to detect an output voltage, the two vibration surfaces intersect with the excitation unit vibrated. When the piezoelectric vibrator itself is rotated about the axis parallel to the line as a central axis, the above-mentioned Coriolis force causes a force to act in a direction perpendicular to the vibration direction of the excitation unit, thereby exciting the detection unit. . Since the magnitude of the vibration excited by the detector is proportional to the rotational angular velocity, the magnitude of the rotational angular velocity can be obtained from the magnitude of the output voltage generated by the piezoelectric phenomenon of the detector.

  For example, a camera-integrated VTR, a digital camera, or the like uses a system that detects the amount of camera shake and corrects the shake of the screen. This system requires the detection of the rotational angular velocity of rotational motion about two axes orthogonal to each other. The directions of rotational movement about the two axes are called the yaw direction and the pitch direction, respectively. The rotational angular velocities in the yaw direction and the pitch direction can be detected by using two piezoelectric vibrators and arranging them at right angles to each other.

  However, when the two piezoelectric vibrators are arranged close to each other, the excitation vibrations of the piezoelectric vibrators propagate through the air or a common substrate, causing interference between the two piezoelectric vibrators, This interference becomes noise and the gyro characteristics are degraded. This interference noise appears due to a difference in frequency of excitation vibration between the two piezoelectric vibrators used. The noise increases as the frequency difference decreases. In order to solve this problem, proposals have been made to use two piezoelectric vibrators having different resonance frequencies in which a difference of 200 Hz or more is provided between the resonance frequencies of the two piezoelectric vibrators to be used. This is because the frequency of the interference wave is set to 200 Hz or higher than the signal of about 0.1 to 50 Hz, which is the frequency band of the signal output when camera shake is detected, and this interference noise is removed by a low-pass filter. The level is reduced.

  Therefore, in order to obtain the two piezoelectric vibrators having different resonance frequencies, there is a proposal that piezoelectric vibrators having the same shape and different resonance frequencies can be obtained by using piezoelectric bodies having different propagation speeds of transverse waves. Has been made. This allows the processing steps of the vibrator, jigs, vibrator support members, etc. to be shared, and the production of piezoelectric vibrators having different resonance frequencies can be made with high productivity. Such a piezoelectric vibration gyro is disclosed in Patent Document 1.

  FIG. 1 is a perspective view of a conventional piezoelectric vibration gyro. In this piezoelectric vibrating gyroscope, a columnar piezoelectric vibrator 61 is used to hold one node point of the piezoelectric vibrator 61 with the support member 62 and the support member 64, and the other node point to the support member 63 and the support member 65. It is structured to hold with. Here, the support member 62, the support member 63, the support member 64, and the support member 65 are formed according to the thickness of the piezoelectric vibrator 61 and arranged according to the length. A piezoelectric vibration gyro having such a structure is disclosed in Patent Document 2.

JP-A-9-292229 JP 2001-227953 A

  As described above, in order to reduce interference noise generated when two piezoelectric vibrators are arranged close to each other, two piezoelectric vibrators having different resonance frequencies must be used. However, using piezoelectric bodies having different resonance frequencies and using the same shape of piezoelectric vibrators disclosed in Patent Document 1 with different propagation speeds of transverse waves allows the parts to be shared. Are better. However, piezoelectric materials with different propagation velocities have different physical properties such as electromechanical coupling coefficient, sharpness of mechanical resonance, or temperature characteristics. To drive and detect piezoelectric vibrators with different characteristics, control ICs There is a problem that the circuit configuration becomes complicated.

  In the structure shown in FIG. 1 disclosed in Patent Document 2, the resonance frequency can be changed by changing the length dimension or thickness dimension of the columnar piezoelectric vibrator 61. However, if the length dimension is changed, the position of the node point will change, and if the thickness dimension is changed, the size of the support member will change, so the support member and support member corresponding to each piezoelectric vibrator will be held. There is a problem that the parts to be used are required and the parts cannot be shared, resulting in an increase in the specifications of the parts and a change in the assembly process.

  Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art. Specifically, it is an object of the present invention to provide a piezoelectric vibration gyro that suppresses the generation of interference noise and has little deterioration in characteristics, high productivity, high performance, and low cost.

  The present invention employs the following means in order to solve the above problems. That is, according to the present invention, in order to reduce interference between piezoelectric vibrators, the piezoelectric vibrator has a tuning fork shape, and a plurality of piezoelectric vibrators that differ only in the shape of the arm portion of the tuning fork are arranged on axes orthogonal to each other. The gist is to make the shape and size other than the arm portion of the tuning fork the same in order to arrange and mount and fix the same.

  According to the present invention, there is provided a piezoelectric vibratory gyro comprising two or more piezoelectric vibrators formed by joining two identical arm portions through a joint portion functioning as a fixed end, wherein each piezoelectric vibrator comprises: A piezoelectric vibration gyro is obtained in which only the arm portion has a different shape.

  The shape of the piezoelectric vibrator according to the present invention is such that a structure capable of exciting vibration such as bending and bending and a Coriolis force generated by a rotational force received with respect to the center axis of the vibration are perpendicular to the vibration direction. A structure that can detect the vibration to be excited is preferable. Therefore, a shape like a tuning fork is suitable for the shape of the piezoelectric vibrator, which has two arm portions and a joint portion for joining one end of the two arm portions, and fixing the joint portion. A structure with a cantilever shape is suitable.

  In addition, when two or more piezoelectric vibrators are used, vibrations such as bending and bending interfere with each other, and the detection unit is excited to generate interference noise. Therefore, in order to reduce interference noise generated when two or more piezoelectric vibrators are arranged close to each other, two or more piezoelectric vibrators having different resonance frequencies can be obtained by changing the shape of each of the arm portions only. can get.

  Furthermore, even if the piezoelectric vibrator of the piezoelectric vibration gyro according to the present invention is a piezoelectric vibrator having different resonance frequencies, the joint and the manufacturing apparatus for fixing the joint by making the joint have the same shape and size. It is not necessary to match each of the piezoelectric vibrators having different resonance frequencies, and there is an advantage that they can be shared.

According to the present invention, there is obtained a piezoelectric vibration gyro characterized in that the piezoelectric vibrator is made of a single material. The piezoelectric vibrator according to the present invention includes two arm portions taken out by etching or processing from a single piezoelectric material such as piezoelectric ceramics, quartz, LiNbO ₃ , LiTaO ₃ , or langasite, and the coupling portion. It is desirable to use an integrated piezoelectric vibrator.

  According to the present invention, it is possible to obtain a piezoelectric vibration gyro characterized in that the piezoelectric vibrator is formed by bonding a material having piezoelectricity to an elastic body. The piezoelectric vibrator of the present invention may have a structure in which a piezoelectric material is joined to two arms of an elastic body having a tuning fork shape.

  According to the present invention, there is obtained a piezoelectric vibration gyro characterized in that each piezoelectric element has a different resonance frequency and has a difference of 200 Hz or more. In the present invention, in order to reduce the interference noise, it is preferable that the resonance frequencies of the two or more piezoelectric vibrators are different frequencies, and the difference between the resonance frequencies is 200 Hz or more. Since the interference noise has a frequency component obtained by synthesizing the respective resonance frequencies, when the difference between the respective resonance frequencies is set to 200 Hz or more, the interference noise is also set to 200 Hz or more. It can be removed with a filter.

  According to the present invention, it is possible to obtain a piezoelectric vibration gyro characterized in that the piezoelectric vibrators are housed in the same casing. The piezoelectric vibration gyro according to the present invention is a small piezoelectric vibration gyro by storing two or more of the piezoelectric vibrators in one housing, and can detect a rotational angular velocity of two or more axes with one piezoelectric vibration gyro. It becomes possible.

  According to the present invention, there can be obtained a piezoelectric vibration gyro characterized in that the piezoelectric vibrators are housed in different housings.

  One piezoelectric vibrator according to the present invention can be housed in a single housing to constitute a single-axis rotational angular velocity detecting piezoelectric vibration gyro, and two or more of them can be used. In this case, the detection shaft can be freely designed by mounting each piezoelectric vibration gyro at a position corresponding to the rotation shaft to be detected.

  According to the present invention, there is obtained a piezoelectric vibration gyro characterized in that the piezoelectric vibrators are arranged so as to be orthogonal to each other.

  In the piezoelectric vibrator according to the present invention, two or more piezoelectric vibrators are arranged so that the central axes of bending or bending vibration thereof are orthogonal to each other, so that the rotational angular velocity around the two orthogonal axes can be detected. It becomes possible. Therefore, in order to detect the magnitude of camera shake in a camera-integrated VTR, a digital camera, or the like, it is suitable for a piezoelectric vibration gyro that needs to detect a rotational angular velocity about two axes. In the piezoelectric vibration gyro according to the present invention in which one piezoelectric vibrator is accommodated in one housing, two or more rotation axes for detection purposes may be arranged so as to be orthogonal to each other. A piezoelectric vibration gyro may be used in which two or more of the piezoelectric vibrators are housed in the same casing so that the rotation axes are orthogonal to each other.

  As described above, according to the present invention, in a piezoelectric vibration gyro in which a plurality of piezoelectric vibrators are arranged on orthogonal axes and multi-axis rotational angular velocities are detected, the shape of the tuning fork-shaped piezoelectric vibrator is changed and the resonance frequency is changed. Thus, interference noise can be removed, and a small piezoelectric vibrating gyroscope that does not deteriorate characteristics and impair productivity can be provided.

As the best mode for carrying out the present invention, first, a tuning fork-shaped piezoelectric vibrator is cut out from a single crystal plate of LiNbO ₃ by machining, and a drive electrode and an output signal for applying a drive voltage to the surface are taken out. These detection electrodes are formed by vapor deposition. At this time, the tuning-fork-shaped piezoelectric vibrator has a structure having two arm portions and a coupling portion that couples the short portions of the two arm portions.

  Further, the number of the piezoelectric vibrators is two or more, and only the shape of each arm portion is changed to manufacture piezoelectric vibrators having different resonance frequencies. Specifically, a piezoelectric vibrator in which two arm portions are linear, a piezoelectric vibrator in which the arm portions are straight and partially expanded in the vicinity of the end portion, and a piezoelectric vibration in which the length of the linear arm portion is long A child is manufactured and processed so that a difference in mutual resonance frequency is 200 Hz to 1 kHz. At this time, the shapes of the coupling portions of the two or more piezoelectric vibrators are all the same shape and size.

  Next, a drive detection circuit having a self-excited oscillation circuit for exciting the piezoelectric vibrator and a detection circuit for calculating the detected angular velocity signal is mounted on a substrate having a conductor pattern, and the different resonance frequencies are set. The two types of piezoelectric vibrators are arranged on the same substrate so that the central axes of the excited vibrations are orthogonal to each other, and the coupling portion is fixed. The drive detection circuit is electrically connected to the drive electrode and the detection electrode of the piezoelectric vibrator by wire bonding or flip chip mounting using bumps. By covering the substrate in this state, a piezoelectric vibration gyro capable of detecting two orthogonal angular velocities can be obtained. In addition, according to the present invention, a piezoelectric vibration gyro capable of detecting the angular velocity of the other axis can be obtained by mounting the piezoelectric vibrators by the number of rotation axes that require detection.

  In addition, the piezoelectric vibrators having the different resonance frequencies are mounted on different substrates and manufactured as independent piezoelectric vibration gyros, and when used, the central axes of vibrations excited by the piezoelectric vibrators are orthogonal to each other. By mounting it on the substrate, a piezoelectric vibration gyro capable of detecting two-axis or multi-axis angular velocities that are orthogonal to each other can be obtained.

Hereinafter, embodiments of a piezoelectric vibration gyro according to the present invention will be described in detail with reference to the drawings. FIG. 2 is an exploded perspective view of the piezoelectric vibration gyro according to the first embodiment. In the first embodiment, the piezoelectric vibrator 11, the piezoelectric vibrator 21, and the drive detection circuit 52 are mounted on a substrate 53 having a conductor pattern, and a lid 54 is disposed on the substrate 53. The piezoelectric vibrator 11 and the piezoelectric vibrator 21 were formed by cutting out a LiNbO ₃ single crystal plate having a thickness of 0.25 mm and depositing drive and detection electrodes on the surface thereof. The electrodes are not shown.

  Here, the piezoelectric vibrator 11 has a tuning fork shape composed of two arm portions 11a having a length of 3 mm and a width of 0.5 mm, and a connecting portion 11b having a length of 3 mm and a width of 1.5 mm for connecting the two arm portions 11a. It was. In order to set the difference in resonance frequency with the piezoelectric vibrator 11 to 200 Hz, the piezoelectric vibrator 21 has two arm portions 21a having a length of 3 mm and a width of 0.5 mm, and the width of the 1.5 mm portion from the tip is 0. .. 1 mm wide outer structure. The coupling portion 21b that couples the two arm portions 21a has the same shape and size as the piezoelectric vibrator 11. The resonance frequency of the piezoelectric vibrator 11 was 20 kHz, and the resonance frequency of the piezoelectric vibrator 21 was 19.8 kHz.

  In the first embodiment, the piezoelectric vibrator 11 and the piezoelectric vibrator 21 are fixed to a ceramic substrate 53 with a part of each coupling portion 11b and the coupling portion 21b, and the piezoelectric vibrator 11 and the piezoelectric vibrator 21 described above. The electrodes and the drive detection circuit 52 mounted on the substrate 53 were electrically connected using the conductor pattern on the substrate 53. Mounting and fixing of the piezoelectric vibrator 11 and the piezoelectric vibrator 21 to the ceramic substrate 53 were performed by wire bonding and flip-chip mounting using bumps. The conductor pattern and the like are not shown.

  The drive detection circuit 52 is a circuit for driving and detecting the piezoelectric vibrator 11 and the piezoelectric vibrator 21, and two self-excited so that the piezoelectric vibrator 11 and the piezoelectric vibrator 21 can be driven at respective resonance frequencies. An oscillation circuit was configured. The drive detection circuit 52 has a function of detecting the vibration in the direction perpendicular to the excitation direction generated by the action of the Coriolis force when an angular velocity is applied to the piezoelectric vibrator 11 and the piezoelectric vibrator 21. The proportional output signal was processed, and the function to output the angular velocity with respect to each rotation axis was also provided.

  The piezoelectric vibration gyro according to the first embodiment changes the resonance frequency difference by changing only the shape of the arm portion of the used piezoelectric vibrator, so that the frequency of interference noise generated between the two piezoelectric vibrators is reduced. Since the frequency becomes 200 kHz, it is possible to provide a low-noise piezoelectric vibration gyro that can remove interference noise with a low-pass filter.

In the first embodiment, laser processing is used to cut out the piezoelectric vibrator 11 and the piezoelectric vibrator 21 from the single crystal plate of LiNbO _3. However, wet etching, dry etching, sand blast processing, ultrasonic processing are also used. A processing method such as In addition to the LiNbO ₃ single crystal, the material to be used may be any material having piezoelectricity such as piezoelectric ceramics, quartz, LiTaO ₃ , or langasite. In addition to vapor deposition, the electrode may be formed by printing, plating, sputtering, or the like.

  Further, in the first embodiment, if the shape of the coupling portion is the same shape and size, the shape of the arm portion may be such that the difference in resonance frequency between the piezoelectric vibrator 11 and the piezoelectric vibrator 21 is 200 Hz or more. The shape is not limited to the above.

FIG. 3 is an exploded perspective view of the piezoelectric vibration gyro according to the second embodiment. In the second embodiment, the piezoelectric vibrator 11, the piezoelectric vibrator 31, and the drive detection circuit 52 are mounted on a substrate 53 having a conductor pattern, and a lid 54 is disposed on the substrate 53. The piezoelectric vibrator 11 and the piezoelectric vibrator 31 were formed by cutting out a LiNbO ₃ single crystal plate having a thickness of 0.25 mm and depositing driving and detection electrodes on the surface thereof. The electrodes are not shown.

  Here, the piezoelectric vibrator 11 includes two arm portions 11a having a length of 3 mm and a width of 0.5 mm, and a connecting portion 11b having a length of 3.0 mm and a width of 1.5 mm for connecting the two arm portions 11a. A tuning fork shape was adopted. In order to set the difference in resonance frequency with the piezoelectric vibrator 11 to 200 Hz, the piezoelectric vibrator 31 has a length of 3.1 mm and a width of 0.5 mm, and the two arm parts 21 a are coupled. The connecting portion 21b to be formed has the same shape as the piezoelectric vibrator 11. The resonance frequency of the piezoelectric vibrator 11 was 20 kHz, and the resonance frequency of the piezoelectric vibrator 31 was 19.8 kHz.

  In the second embodiment, the piezoelectric vibrator 11 and the piezoelectric vibrator 31 are fixed to a ceramic substrate 53 with a part of each coupling portion 11b and the coupling portion 31b. The electrodes and the drive detection circuit 52 mounted on the substrate 53 were electrically connected using the conductor pattern on the substrate 53. Mounting and fixing of the piezoelectric vibrator 11 and the piezoelectric vibrator 31 to the ceramic substrate 53 was performed by flip chip mounting using wire bonding and bumps. The conductor pattern and the like are not shown.

  The drive detection circuit 52 is a circuit for driving and detecting the piezoelectric vibrator 11 and the piezoelectric vibrator 21, and two self-excited so that the piezoelectric vibrator 11 and the piezoelectric vibrator 21 can be driven at respective resonance frequencies. An oscillation circuit was configured. The drive detection circuit 52 has a function of detecting the vibration in the direction perpendicular to the excitation direction generated by the action of the Coriolis force when an angular velocity is applied to the piezoelectric vibrator 11 and the piezoelectric vibrator 21. The proportional output signal was processed, and the function to output the angular velocity with respect to each rotation axis was also provided.

  In the piezoelectric vibration gyro according to the second embodiment, the difference in the resonance frequency is set to 200 Hz by changing only the length of the arm portion of the used piezoelectric vibrator. The frequency of the interference noise generated in the filter becomes 200 kH, and it is possible to provide a low-noise piezoelectric vibration gyro that can remove the interference noise with a low-pass filter.

  In FIG. 3, the dimensional differences are greatly illustrated for easy understanding, but in order to obtain a frequency difference that can suppress interference noise including practical variations, the arm portion 11a and the arm shown in FIG. The difference in length of the portion 31a may be about 0.1 mm. In addition, since the processing accuracy of 10 μm or less can be obtained with the current processing technology, dimensional management of 0.1 mm is sufficiently possible.

  FIG. 4 is an exploded perspective view of the piezoelectric vibration gyro according to the third embodiment. In the third embodiment, the piezoelectric vibrator 11, the piezoelectric vibrator 41, and the drive detection circuit 52 are mounted on a substrate 53 having a conductor pattern, and a lid 54 is disposed on the substrate 53. The piezoelectric vibrator 11 was formed by cutting out a LiNbO3 single crystal plate having a thickness of 0.250 mm and depositing drive and detection electrodes on the surface thereof. The piezoelectric vibrator 41 was cut out from a LiNbO3 single crystal plate having a thickness of 0.255 mm, and electrodes for driving and detection were deposited on the surface thereof. The electrodes are not shown.

  Here, the piezoelectric vibrator 11 and the piezoelectric vibrator 41 have two arm portions 11a having a length of 3 mm and a width of 0.5 mm, and a joint having a length of 3.0 mm and a width of 1.5 mm for joining the two arm portions 11a. A tuning fork shape consisting of the portion 11b was adopted. The piezoelectric vibrator 41 is different from the piezoelectric vibrator 11 only in thickness, and the resonance frequency is lowered. In Example 3, the resonance frequency of the piezoelectric vibrator 11 was 20 kHz, and the resonance frequency of the piezoelectric vibrator 41 was 19.8 kHz.

  In the third embodiment, the piezoelectric vibrator 11 and the piezoelectric vibrator 41 are fixed to a ceramic substrate 53 with a part of each coupling portion 11b and the coupling portion 41b, and the electrodes of the piezoelectric vibrator 11 and the piezoelectric vibrator 41 are used. The drive detection circuit 52 mounted on the substrate 53 was electrically connected using the conductor pattern on the substrate 53. Mounting and fixing of the piezoelectric vibrator 11 and the piezoelectric vibrator 41 to the ceramic substrate 53 were performed by flip chip mounting using wire bonding and bumps. The conductor pattern and the like are not shown.

  The drive detection circuit 52 is a circuit for driving and detecting the piezoelectric vibrator 11 and the piezoelectric vibrator 21, and two self-excited so that the piezoelectric vibrator 11 and the piezoelectric vibrator 21 can be driven at respective resonance frequencies. An oscillation circuit was configured. The drive detection circuit 52 has a function of detecting the vibration in the direction perpendicular to the excitation direction generated by the action of the Coriolis force when an angular velocity is applied to the piezoelectric vibrator 11 and the piezoelectric vibrator 21. The proportional output signal was processed, and the function to output the angular velocity with respect to each rotation axis was also provided.

  The piezoelectric vibration gyro according to the third embodiment changes the resonance frequency difference by changing only the length of the arm portion of the used piezoelectric vibrator, so that the difference between the two piezoelectric vibrators is the same as in the first embodiment. The frequency of the interference noise generated in the filter becomes 200 kH, and it is possible to provide a low-noise piezoelectric vibration gyro that can remove the interference noise with a low-pass filter.

  In FIG. 4, the dimensional differences are greatly illustrated for easy understanding, but in order to obtain a frequency difference that can suppress interference noise including practical variations, the thickness of the piezoelectric vibrator shown in FIG. The difference may be about 0.005 mm. Note that with the current thickness processing technology, a processing accuracy of 0.5 μm or less can be obtained by lapping processing or the like, and therefore 5 μm dimension management is sufficiently possible.

  In Example 3, piezoelectric vibrators having different thicknesses were used. However, since the structure is not configured to grip the thickness direction of the piezoelectric elements, the parts and manufacturing process used are not affected even if the thicknesses are different. .

  5 and 6 are exploded perspective views of the piezoelectric vibration gyro according to the fourth embodiment. In Example 4, two piezoelectric vibration gyros are used. First, as shown in FIG. 5, the drive detection circuit 12 is mounted on a substrate 13 having a conductor pattern in advance, only the piezoelectric vibrator 11 manufactured in the first embodiment is mounted on the substrate 13, and the lid 14 is covered. Thus, the piezoelectric vibrating gyroscope 10 was configured. The other is a piezoelectric vibrating gyroscope as shown in FIG. 6, like the piezoelectric vibrating gyroscope 10, in which the drive detection circuit 12 is mounted in advance on a substrate 13 having a conductor pattern, and the piezoelectric vibrator manufactured in the first embodiment. The piezoelectric vibration gyro 20 was configured by mounting only 21 on the substrate 13 and covering the lid 14.

The piezoelectric vibrator 11 and the piezoelectric vibrator 21 according to the fourth embodiment are cut from a LiNbO ₃ single crystal plate having a thickness of 0.25 mm and formed by depositing drive and detection electrodes on the surface thereof, as in the first embodiment. did. The piezoelectric vibrator 11 has a tuning fork shape composed of two arm portions 11a having a length of 3 mm and a width of 0.5 mm, and a connecting portion 11b having a length of 3 mm and a width of 1.5 mm for connecting the two arm portions 11a. In order to set the difference in resonance frequency with the piezoelectric vibrator 11 to 200 Hz, the piezoelectric vibrator 21 has two arm portions 21a having a length of 3 mm and a width of 0.5 mm, and the width of the 1.5 mm portion from the tip is 0. .. 1 mm wide outer structure. A coupling portion 21 b that couples the two arm portions 21 a has the same shape as the piezoelectric vibrator 11. The resonance frequency of the piezoelectric vibrator 11 was 20 kHz, and the resonance frequency of the piezoelectric vibrator 21 was 19.8 kHz.

  In the fourth embodiment, the same components are used for the substrate 13, the drive detection circuit 12, and the lid 14 used in FIGS. 5 and 6. Thus, even if the piezoelectric vibrator 11 and the piezoelectric vibrator 21 are piezoelectric vibrators having different resonance frequencies, the same parts can be used for manufacturing the piezoelectric vibration gyro. This is an effect in which the shapes of the coupling portion 11b and the coupling portion 21b are made the same only in the shape of the arm portion.

  In order to detect the biaxial angular velocity using the piezoelectric vibrating gyroscope according to the fourth embodiment, the piezoelectric vibrating gyroscope 10 shown in FIG. 5 and the piezoelectric vibrating gyroscope 20 shown in FIG. That's fine. FIG. 7 is a perspective view illustrating a usage state of the piezoelectric vibration gyro according to the fourth embodiment. The piezoelectric vibration gyro 10 and the piezoelectric vibration gyro 20 are mounted on the circuit board 55 of a device that requires detection of the angular velocity, and the X axis that is the central axis of the excitation vibration of the piezoelectric vibrator 11 used in the piezoelectric vibration gyro 10 56 and the Y axis 57 that is the central axis of the excitation vibration of the piezoelectric vibrator 21 used in the piezoelectric vibration gyro 20 are arranged so as to be orthogonal to each other so that the yaw direction and the pitch direction of the biaxial angular velocity can be obtained. Detection is possible.

  At this time, since the resonance frequency difference between the piezoelectric vibrator 11 and the piezoelectric vibrator 21 according to the fourth embodiment used for the piezoelectric vibration gyro 10 and the piezoelectric vibration gyro 20 is 200 Hz, the interference noise due to mutual interference becomes 200 Hz. Thus, it is possible to provide a low-noise piezoelectric vibration gyro that can remove interference noise.

  In the fourth embodiment, the piezoelectric vibrator 41 having a different resonance frequency by changing the thickness of the piezoelectric vibrator shown in the third embodiment may be used. Even in this case, since the piezoelectric element is not configured to be gripped in the thickness direction, it is not affected by the difference in thickness, and a component having the same specification as that of a piezoelectric vibrator having another resonance frequency can be used. .

  As described above, according to the present invention, even when the piezoelectric vibrator has a tuning fork shape and the arm portion shape of the tuning fork is changed, the resonance frequency of the piezoelectric vibrator is changed and arranged on axes orthogonal to each other. The mounting and fixing method can be made the same by reducing the interference between the piezoelectric vibrators and making the shape and size other than the tuning fork arm part the same. It is possible to provide a small, high-performance, low-cost piezoelectric vibration gyro with low productivity.

  The piezoelectric vibration gyro according to the present invention can be used in a system for detecting camera shake such as a camera-integrated VTR or a digital camera. In addition, as an angular velocity detection sensor, the piezoelectric vibration gyro can be used in an angular velocity detection device such as vibration or impact, a device, or a navigation system. Can also be used.

The perspective view of the conventional piezoelectric vibration gyro. 1 is an exploded perspective view of a piezoelectric vibration gyro according to Embodiment 1. FIG. FIG. 4 is an exploded perspective view of a piezoelectric vibration gyro according to a second embodiment. FIG. 6 is an exploded perspective view of a piezoelectric vibration gyro according to a third embodiment. FIG. 9 is an exploded perspective view of a piezoelectric vibration gyro according to a fourth embodiment. FIG. 9 is an exploded perspective view of a piezoelectric vibration gyro according to a fourth embodiment. FIG. 6 is a perspective view showing a usage state of a piezoelectric vibration gyro according to a fourth embodiment.

Explanation of symbols

10, 20 Piezoelectric vibratory gyros 11, 21, 31, 41 Piezoelectric vibrators 11a, 21a, 31a, 41a Arm parts 11b, 21b, 31b, 41b Coupling parts 12, 52 Drive detection circuit 13, 53 Substrate 14, 54 Lid 55 Circuit Substrate 56 X-axis 57 Y-axis 61 Piezoelectric vibrator 62, 63, 64, 65 Support member

Claims (7)

  A piezoelectric vibration gyro comprising two or more piezoelectric vibrators formed by joining two identical arm parts via a joint functioning as a fixed end, wherein each piezoelectric vibrator differs only in the arm part. A piezoelectric vibration gyro characterized by having a shape.   The piezoelectric vibration gyro according to claim 1, wherein the piezoelectric vibrator is made of a single material.   The piezoelectric vibration gyro according to claim 1, wherein the piezoelectric vibrator is formed by bonding a material having piezoelectricity to an elastic body.   4. The piezoelectric vibration gyro according to claim 1, wherein the piezoelectric elements have different resonance frequencies and have a difference of 200 Hz or more. 5.   5. The piezoelectric vibration gyro according to claim 1, wherein the piezoelectric vibrators are housed in the same housing.   The piezoelectric vibration gyro according to any one of claims 1 to 4, wherein each of the piezoelectric vibrators is housed in a different housing.   The piezoelectric vibration gyro according to any one of claims 1 to 6, wherein the piezoelectric vibrators are arranged so as to be orthogonal to each other.

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