JP2017090398A - Vibration piece, vibration device, electronic apparatus and movable body - Google Patents

Vibration piece, vibration device, electronic apparatus and movable body Download PDF

Info

Publication number
JP2017090398A
JP2017090398A JP2015224541A JP2015224541A JP2017090398A JP 2017090398 A JP2017090398 A JP 2017090398A JP 2015224541 A JP2015224541 A JP 2015224541A JP 2015224541 A JP2015224541 A JP 2015224541A JP 2017090398 A JP2017090398 A JP 2017090398A
Authority
JP
Japan
Prior art keywords
vibrating
arms
detection
arm
resonator element
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2015224541A
Other languages
Japanese (ja)
Inventor
石井 昌宏
Masahiro Ishii
昌宏 石井
菊池 尊行
Takayuki Kikuchi
菊池  尊行
Original Assignee
セイコーエプソン株式会社
Seiko Epson Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by セイコーエプソン株式会社, Seiko Epson Corp filed Critical セイコーエプソン株式会社
Priority to JP2015224541A priority Critical patent/JP2017090398A/en
Publication of JP2017090398A publication Critical patent/JP2017090398A/en
Pending legal-status Critical Current

Links

Images

Abstract

An object of the present invention is to provide a resonator element, a vibration device, an electronic apparatus, and a moving body that have excellent Q value adjustment accuracy.
A resonator element includes a base, a detection arm connected to the base, a first detection signal electrode and a second detection signal electrode disposed on the detection arm, and a base. And adjusting arms 251 and 252 that couple and vibrate with the detection arm 221, and the lengths of the adjustment arms 251 and 252 are smaller than the length of the detection arm 221. The width is smaller than the width of the detection arm 221, and when the Q value of the detection arm 221 is Q1, and the Q value of the adjustment arms 251 and 252 is Q2, the relationship of Q1> Q2 is satisfied.
[Selection] Figure 1

Description

  The present invention relates to a resonator element, a vibration device, an electronic apparatus, and a moving body.

  Conventionally, a configuration described in Patent Document 1 is known as a gyro sensor element (vibration piece). The gyro sensor element described in Patent Literature 1 includes a base, a pair of detection arms extending from the base to both sides in the Y-axis direction, a pair of connection arms extending from the base to both sides in the X-axis direction, and one connection arm. And a pair of drive arms extending from the tip of the other connecting arm to both sides in the Y-axis direction. In the gyro sensor element of Patent Document 1, grooves are provided on the upper and lower surfaces of the drive arm, and when the flexural vibration frequency of the drive arm is f and the relaxation vibration frequency of the drive arm is fm, f / fm> 1. The Q value is increased by satisfying the above range.

JP 2012-63177 A

  However, since it is necessary to ensure the vibration characteristics and the electrical characteristics of the detection signal, there are large restrictions when changing the shape of the drive arm, and it is difficult to adjust the Q value to a predetermined value. That is, it is difficult to appropriately control the Q value by improving the structure of the driving arm.

  An object of the present invention is to provide a resonator element, a vibration device, an electronic apparatus, and a moving body that have excellent Q value adjustment accuracy.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

The resonator element according to this application example includes a base,
A first vibrating arm connected to the base;
A signal electrode disposed on the first vibrating arm;
A second vibrating arm connected to the base and oscillating in combination with the first vibrating arm;
With
The length of the second vibrating arm is smaller than the length of the first vibrating arm,
The width of the second vibrating arm is smaller than the width of the first vibrating arm,
The Q value of the first vibrating arm and the Q value of the second vibrating arm are different.
Thereby, since the Q value of the first vibrating arm can be adjusted by the second vibrating arm, the Q value can be adjusted without greatly changing the design of the first vibrating arm. For this reason, the resonator element is excellent in Q value adjustment accuracy.

In the application example described above, the Q value of the first vibrating arm is Q1,
When the Q value of the second vibrating arm is Q2,
It is preferable to satisfy the relationship of Q1> Q2.
As a result, the Q value of the vibration mode of the first vibrating arm can be adjusted to decrease.

In the application example described above, it is preferable that the relationship of Q1 / 5> Q2 is satisfied.
As a result, the Q value of the vibration mode of the first vibrating arm can be adjusted to decrease.

In the application example described above, the driving unit is connected to the base and vibrates.
The first vibrating arm vibrates in accordance with an applied physical quantity,
The signal electrode is preferably an electrode that acquires a detection signal generated by the detection signal.
As a result, the Q value of the detection vibration mode can be adjusted to decrease. Therefore, excitation of the detection mode due to disturbance can be reduced.

In the application example described above, the two second vibrating arms are provided,
It is preferable that the first vibrating arm is disposed between the two second vibrating arms.
Accordingly, the vibration of the first vibrating arm can be easily coupled to the second vibrating arm, and the first vibrating arm and the second vibrating arm can be vibrated as a whole with a good balance.

In the application example described above, the Q value of the first vibrating arm is Q1,
When the Q value of the second vibrating arm is Q2,
It is preferable to satisfy the relationship of Q1 <Q2.
Thereby, it can adjust to the direction which raises Q value of the vibration mode of a 1st vibration arm.

In the application example described above, it is preferable to satisfy the relationship of 5 · Q1 <Q2.
Thereby, it can adjust to the direction which raises Q value of the vibration mode of a 1st vibration arm.

In the application example described above, the two first vibrating arms are included,
It is preferable that the two first vibrating arms vibrate in opposite phases.
As a result, the two first vibrating arms can be vibrated with good balance.

In the application example described above, the two second vibrating arms are included.
It is preferable that the two second vibrating arms vibrate in opposite phases.
As a result, the two second vibrating arms can be vibrated with good balance.

In the application example described above, it is preferable that the signal electrode is not disposed on the second vibrating arm.
Thereby, for example, it is possible to prevent a signal from being applied to the second vibrating arm or a signal from being taken out from the second vibrating arm.

The vibration device according to this application example includes the above-described vibration piece,
And a package for housing the resonator element.
Thereby, a highly reliable vibration device is obtained.

The vibration device according to this application example includes the above-described vibration piece,
And a circuit connected to the resonator element.
Thereby, a highly reliable vibration device is obtained.

An electronic apparatus according to this application example includes the above-described vibration piece.
As a result, a highly reliable electronic device can be obtained.

The moving body according to this application example includes the above-described vibration piece.
Thereby, a mobile body with high reliability is obtained.

FIG. 3 is a perspective view of a resonator element according to the first embodiment of the invention. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is a schematic diagram which shows a drive vibration mode. It is a schematic diagram which shows a Y-axis detection vibration mode. It is a schematic diagram which shows Z-axis detection vibration mode. It is a graph which shows the relationship between Q value and fd / f1. FIG. 6 is a perspective view of a resonator element according to a second embodiment of the invention. FIG. 6 is a perspective view of a resonator element according to a third embodiment of the invention. It is CC sectional view taken on the line in FIG. FIG. 10 is a schematic diagram illustrating a vibration state of the resonator element illustrated in FIG. 9. It is a graph which shows the relationship between Q value and fr / f4. FIG. 10 is a perspective view of a resonator element according to a fourth embodiment of the invention. FIG. 14 is a schematic diagram illustrating a driving state of the resonator element illustrated in FIG. 13. It is sectional drawing of the physical quantity detection apparatus to which the vibration device of this invention is applied. FIG. 16 is a block diagram of the physical quantity detection device shown in FIG. 15. 1 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer to which an electronic apparatus of the present invention is applied. It is a perspective view which shows the structure of the mobile telephone (PHS is also included) to which the electronic device of this invention is applied. It is a perspective view which shows the structure of the digital still camera to which the electronic device of this invention is applied. It is a perspective view which shows the motor vehicle to which the mobile body of this invention is applied.

  Hereinafter, a resonator element, a vibrating device, an electronic apparatus, and a moving body according to the present invention will be described in detail based on embodiments shown in the accompanying drawings.

<First Embodiment>
First, the physical quantity detection vibrating piece according to the first embodiment of the present invention will be described.

  FIG. 1 is a perspective view of a resonator element according to the first embodiment of the invention. 2 is a cross-sectional view taken along line AA in FIG. 3 is a cross-sectional view taken along line BB in FIG. FIG. 4 is a schematic diagram showing the drive vibration mode. FIG. 5 is a schematic diagram illustrating the Y-axis detection vibration mode. FIG. 6 is a schematic diagram illustrating the Z-axis detection vibration mode. FIG. 7 is a graph showing the relationship between the Q value and fd / f1. In the following, for convenience of explanation, the crystal axes of quartz are the X axis (electrical axis), the Y axis (mechanical axis), and the Z axis (optical axis), and the direction along the X axis is also referred to as the “X axis direction”. The direction along the Y axis is also referred to as the “Y axis direction”, and the direction along the Z axis is also referred to as the “Z axis direction”. The + Z-axis side is also referred to as “upper”, and the −Z-axis side is also referred to as “lower”.

  A vibrating piece 1 shown in FIG. 1 is an angular velocity detecting vibrating piece that can independently detect an angular velocity ωz about the Z axis and an angular velocity ωy about the Y axis. Such a vibrating piece 1 includes a vibrating body 2 and a signal electrode disposed on the vibrating body 2.

  The vibrating body 2 is made of quartz. Further, the vibrating body 2 has a plate shape having a spread in the XY plane defined by the X-axis and the Y-axis which are crystal axes of quartz and having a thickness in the Z-axis direction. That is, the vibrating body 2 is formed by patterning a Z-cut quartz plate. However, the cut angle of the crystal is not particularly limited as long as the object can be achieved. For example, the Z axis may be slightly shifted with respect to the thickness direction of the vibrating body 2.

  The constituent material of the vibrating body 2 is not limited to quartz, and for example, piezoelectric materials other than quartz such as lithium tantalate, lithium niobate, lithium borate, and barium titanate may be used.

  Such a vibrating body 2 includes a base 21, detection arms (first vibrating arms) 221 and 222 extending from the base 21 toward both sides in the Y-axis direction, and extending from the base 21 toward both sides in the X-axis direction. Connecting arms 231 and 232, driving arms (driving portions) 241 and 242 extending from the tip of the connecting arm 231 toward both sides in the Y-axis direction, and from the tip of the connecting arm 232 toward both sides in the Y-axis direction. Extending driving arms (driving portions) 243 and 244, a pair of adjusting arms (second vibrating arms) 251 and 252 extending from the base portion 21 toward the + Y-axis direction, and from the base portion 21 toward the -Y-axis direction And a pair of adjustment arms (second vibration arms) 253 and 254 that extend. According to such a configuration, the arms 221, 222, 241 to 244, and 251 to 254 are arranged in a balanced manner, and the resonator element 1 can be vibrated in a balanced manner. Therefore, vibration leakage can be reduced.

  The detection arm 221 includes an arm part 221A and a wide part (hammer head part) 221B which is located on the distal end side of the arm part 221A and is wider than the arm part 221A. As shown in FIG. 2, a groove 2211 extending in the Y-axis direction is formed on the upper surface of the arm 221A, and a groove 2212 extending in the Y-axis direction is formed on the lower surface of the arm 221A. Therefore, the arm portion 221A has an H-shaped cross-sectional shape.

  The detection arm 222 includes an arm portion 222A and a wide portion (hammer head portion) 222B which is located on the distal end side of the arm portion 222A and is wider than the arm portion 222A. Further, as shown in FIG. 3, a groove portion 2221 extending in the Y-axis direction is formed on the upper surface of the arm portion 222A, and a groove portion 2222 extending in the Y-axis direction is formed on the lower surface of the arm portion 222A. Therefore, the arm portion 222A has an H-shaped cross-sectional shape.

  These detection arms 221 and 222 are provided on both sides of the base 21 and are arranged symmetrically with respect to an axis Jx passing through the center of gravity of the base 21 along the X axis. With such an arrangement, as described later, the angular velocity ωy and the angular velocity ωz can be detected independently using the difference in the combination of the vibration directions of the detection arms 221 and 222.

  The drive arm 241 includes an arm portion 241A and a wide portion (hammer head portion) 241B that is positioned on the distal end side of the arm portion 241A and wider than the arm portion 241A. As shown in FIG. 2, a groove 2411 extending in the Y-axis direction is formed on the upper surface of the arm 241A, and a groove 2412 extending in the Y-axis direction is formed on the lower surface of the arm 241A. Further, a stepped portion 2413 that connects the upper surface and the side surface of the arm portion 241A is formed on the −X axis side of the groove portion 2411, and the lower surface and the side surface of the arm portion 241A are connected to the + X axis side of the groove portion 2412. A stepped portion 2414 to be connected is formed.

  The drive arm 242 has an arm part 242A and a wide part (hammer head part) 242B which is located on the distal end side of the arm part 242A and is wider than the arm part 242A. Also, as shown in FIG. 3, a groove 2421 extending in the Y-axis direction is formed on the upper surface of the arm 242A, and a groove 2422 extending in the Y-axis direction is formed on the lower surface of the arm 242A. Further, a stepped portion 2423 that connects the upper surface and the side surface of the arm portion 242A is formed on the −X axis side of the groove portion 2421, and the lower surface and the side surface of the arm portion 242A are connected to the + X axis side of the groove portion 2422. A stepped portion 2424 to be connected is formed.

  The drive arm 243 has an arm portion 243A and a wide portion (hammer head portion) 243B that is positioned on the distal end side of the arm portion 243A and wider than the arm portion 243A. As shown in FIG. 2, a groove 2431 extending in the Y-axis direction is formed on the upper surface of the arm 243A, and a groove 2432 extending in the Y-axis direction is formed on the lower surface of the arm 243A. Further, a stepped portion 2433 is formed on the + X axis side of the groove portion 2431 to connect the upper surface and the side surface of the arm portion 243A, and the lower surface and side surface of the arm portion 243A are connected to the −X axis side of the groove portion 2412. A stepped portion 2434 to be connected is formed.

  The drive arm 244 has an arm portion 244A and a wide portion (hammer head portion) 244B which is located on the distal end side of the arm portion 244A and is wider than the arm portion 244A. Further, as shown in FIG. 3, a groove portion 2441 extending in the Y-axis direction is formed on the upper surface of the arm portion 244A, and a groove portion 2442 extending in the Y-axis direction is formed on the lower surface of the arm portion 244A. In addition, a stepped portion 2443 is formed on the + X axis side of the groove portion 2441 to connect the upper surface and the side surface of the arm portion 244A. A stepped portion 2444 to be connected is formed.

  Among these drive arms 241 to 244, the drive arms 241 and 243 and the drive arms 242 and 244 are arranged symmetrically with respect to the axis Jx, and the drive arms 241 and 242 and the drive arms 243 and 244 are located at the center of gravity. And symmetrically arranged with respect to the axis Jy along the Y axis. The drive arms 241 to 244 have an asymmetric cross-sectional shape with respect to both the arm center line Lx in the X-axis direction and the center line Lz in the Z-axis direction. By adopting such a shape, as will be described later, in the drive vibration mode, the drive arms 241 to 244 can be vibrated in an oblique direction including the X-axis component and the Z-axis component.

  The adjustment arms 251, 252, 253, and 254 are arms for adjusting the Q value of a detection vibration mode (described later) of the detection arms 221 and 222. As shown in FIGS. 1 and 2, the adjustment arms 251 and 252 are arranged with the detection arm 221 sandwiched therebetween, and vibrate in combination with the vibration of the detection arm 221. In this manner, by arranging the detection arm 221 between the two adjustment arms 251 and 252, symmetry is created, and the detection arm 221 and the adjustment arms 251 and 252 can be vibrated with good balance. On the other hand, as shown in FIGS. 1 and 3, the adjustment arms 252 and 253 are arranged with the detection arm 222 interposed therebetween, and vibrate in combination with the vibration of the detection arm 222. In this manner, by arranging the detection arm 222 between the two adjustment arms 253 and 254, symmetry is created, and the detection arm 222 and the adjustment arms 253 and 254 can be vibrated with good balance.

  Further, the adjustment arms 251 to 254 have substantially the same width W1 across the entire area, and the width W1 is smaller than the width W2 of the arm portions 221A and 222A of the detection arms 221 and 222. The length L1 of the adjustment arms 251 to 254 is shorter than the length L2 of the detection arms 221 and 222. As described above, by making the adjustment arms 251 to 254 smaller than the detection arms 221 and 222, the enlargement of the resonator element 1 can be reduced. The functions of the adjusting arms 251, 252, 253, and 254 will be described in detail later.

  Next, the signal electrode disposed on the vibrating body 2 will be described. As shown in FIGS. 1 to 3, the signal electrode disposed on the vibrating body 2 includes a drive signal electrode 31, a drive ground electrode 32, a first detection signal electrode 33, a second detection signal electrode 34, 3 detection signal electrodes 35 and a fourth detection signal electrode 36.

  The drive signal electrode 31 includes an upper surface and a lower surface of the drive arm 241 (in the grooves 2411 and 2412), an upper surface and a lower surface of the drive arm 242 (in the grooves 2421 and 2422), both side surfaces of the drive arm 243, and the drive arm 244. It is arranged on both sides. Such a drive signal electrode 31 is an electrode for applying a drive signal (voltage) for driving and vibrating the drive arms 241 to 244.

  The drive ground electrode 32 includes both side surfaces of the drive arm 241, both side surfaces of the drive arm 242, upper and lower surfaces (in the grooves 2431 and 2432) of the drive arm 243, and upper and lower surfaces (groove portions 2441 and 2442) of the drive arm 244. Inside). Such a drive ground electrode 32 is an electrode that serves as a ground (reference potential) with respect to the drive signal electrode 31.

  The first detection signal electrodes 33 are disposed on the upper and lower surfaces (in the grooves 2211 and 2122) of the detection arm 221. Such a first detection signal electrode 33 is an electrode for acquiring the first detection signal S1 based on the Coriolis force generated by applying the angular velocity.

  The second detection signal electrodes 34 are disposed on both side surfaces of the detection arm 221. Such a second detection signal electrode 34 is an electrode for acquiring the second detection signal S2 based on the Coriolis force generated by applying the angular velocity.

  The third detection signal electrode 35 is disposed on the upper surface and the lower surface of the detection arm 222 (in the grooves 2221 and 2222). Such a third detection signal electrode 35 is an electrode for acquiring the third detection signal S3 based on the Coriolis force generated by applying the angular velocity.

  The fourth detection signal electrodes 36 are disposed on both side surfaces of the detection arm 222. Such a fourth detection signal electrode 36 is an electrode for acquiring the fourth detection signal S4 based on the Coriolis force generated when the angular velocity is applied.

  Such signal electrodes (the drive signal electrode 31, the drive ground electrode 32, and the first to fourth detection signal electrodes 33 to 36) are not disposed on the adjustment arms 251 to 254. That is, the adjusting arms 251 to 254 do not drive vibration like the driving arms 241 to 244 and do not take out detection signals based on Coriolis force like the detection arms 221 and 222. In other words, the adjustment arms 251 to 254 are vibration arms used for adjusting the Q value of the detection vibration mode without contributing to detection unless contributing to driving.

  The configuration of the resonator element 1 has been briefly described above. Such a resonator element 1 can detect the angular velocity ωy around the Y axis and the angular velocity ωz around the Z axis as follows.

  First, when a drive signal is applied between the drive signal electrode 31 and the drive ground electrode 32, the drive arms 241 to 244 vibrate in a drive vibration mode as shown in FIG. Specifically, the drive arms 241 to 244 each vibrate obliquely including an X-axis direction component and a Z-axis direction component. This is because when the drive signal is applied, the drive arms 241 to 244 tend to bend and vibrate in the X-axis direction due to the inverse piezoelectric effect. This is because a vibration component in the Z-axis direction is generated due to the (asymmetric shape), and as a result, the vibration occurs in an oblique direction including the X-axis direction component and the Z-axis direction component.

  When an angular velocity ωy about the Y axis is applied to the resonator element 1 while driving in the drive vibration mode, a Y axis detection vibration mode as shown in FIG. 5 is newly excited. In this Y-axis detection vibration mode, Coriolis force acts on the drive arms 241 to 244 to excite vibration in the direction indicated by arrow A, and the detection arms 221 and 222 indicate arrow B so as to respond to this vibration. Flexurally vibrates in the direction (X-axis direction). Further, the adjustment arms 251 and 252 are coupled to the bending vibration of the detection arm 221 to bend and vibrate in the direction indicated by the arrow C (X-axis direction), and the adjustment arms 253 and 254 are coupled to the bending vibration of the detection arm 222. Bend and vibrate in the direction indicated by arrow C (X-axis direction). The charges generated in the detection arms 221 and 222 by the vibration in the Y-axis detection mode are taken out from the first to fourth detection signal electrodes 33 to 36 as the first to fourth detection signals S1 to S4, and based on this signal Angular velocity ωy can be detected.

  On the other hand, when an angular velocity ωz around the Z axis is applied to the resonator element 1 while driving in the drive vibration mode, a Z axis detection vibration mode as shown in FIG. 6 is newly excited. In this Z-axis detection vibration mode, Coriolis force acts on the driving arms 241 to 244 to excite vibration in the direction indicated by arrow D, and the detection arms 221 and 222 indicate arrow E so as to respond to this vibration. Flexurally vibrates in the direction (X-axis direction). Further, the adjustment arms 251 and 252 are coupled to the bending vibration of the detection arm 221 to bend and vibrate in the direction indicated by the arrow F (X-axis direction), and the adjustment arms 253 and 254 are coupled to the bending vibration of the detection arm 222 to be adjusted. Bend and vibrate in the direction indicated by arrow F (X-axis direction). The charges generated in the detection arms 221 and 222 by such vibration are taken out from the first to fourth detection signal electrodes 33 to 36 as the first to fourth detection signals S1 to S4, and the angular velocity ωz is detected based on this signal. be able to.

  In the detection vibration mode (the Y-axis detection vibration mode and the Z-axis detection vibration mode), the bending vibration frequency of the adjustment arms 251 to 254 is set so that the adjustment arms 251 to 254 can be easily coupled with the vibrations of the detection arms 221 and 222. It is preferable to set the detection arms 221 and 222 to be approximately equal to the bending vibration frequency.

  Here, when the angular velocity ωy is applied, as shown in FIG. 5, the detection arms 221 and 222 bend and vibrate in phase in the X-axis direction. On the other hand, when the angular velocity ωz is applied, as shown in FIG. 6, the detection arms 221 and 222 bend and vibrate in the opposite phase in the X-axis direction. The resonator element 1 can detect the angular velocity ωy and the angular velocity ωz independently of each other by utilizing the difference in the combination of vibration directions of the detection arms 221 and 222. This will be described in detail below.

  When the angular velocity ωy is applied to the resonator element 1, as described above, the detection arms 221 and 222 bend and vibrate in phase in the X-axis direction. The second and fourth detection signals S2 and S4 generated at this time are in reverse phase with the first and third detection signals S1 and S3. Therefore, assuming that the intensities of the detection signals S1 to S4 are equal, if the first detection signal S1 = + Sy generated by adding the angular velocity ωy, the second detection signal S2 = −Sy and the third detection signal S3 = + Sy, and the fourth detection signal S4 = −Sy.

  On the other hand, when the angular velocity ωz is applied to the resonator element 1, the detection arms 221 and 222 bend and vibrate in the opposite phase in the X-axis direction as described above. The second and third detection signals S2 and S3 generated at this time are in reverse phase with the first and fourth detection signals S1 and S4. Therefore, assuming that the intensities of the detection signals S1 to S4 are equal, if the first detection signal S1 = + Sz generated by adding the angular velocity ωz, the second detection signal S2 = −Sz and the third detection signal S3 = −Sz and the fourth detection signal S4 = + Sz.

  For this reason, the first detection that occurs when the angular velocity ωyz around the axis having both components in the Y-axis direction and the Z-axis direction (that is, the axis inclined with respect to both the Y-axis and Z-axis) is applied to the resonator element 1. When the signal S1 = + Sy + Sz, the second detection signal S2 = −Sy−Sz, the third detection signal S3 = + Sy−Sz, and the fourth detection signal S4 = −Sy + Sz.

  By adjusting the detection signals S1, S2, S3, and S4 to each other, the angular velocity ωy and the angular velocity ωz can be separated from the angular velocity ωyz, and the angular velocity ωy and the angular velocity ωz can be detected independently. .

  Specifically, the calculation of (S1−S2) is performed on the detection arm 221 to (+ Sy + Sz) − (− Sy−Sz) = 2 (Sy + Sz), and the detection signal obtained from the detection arm 221 is doubled. Similarly, by performing the calculation of (S3−S4) for the detection arm 222, (+ Sy−Sz) − (− Sy + Sz) = 2 (Sy−Sz) is obtained, and the detection signal obtained from the detection arm 221 is doubled.

Then, by calculating (S1-S2) + (S3-S4), 2 (Sy + Sz) +2 (Sy-Sz) = 4Sy, and the signal Sy resulting from the angular velocity ωy can be separated. Thereby, the angular velocity ωy is obtained. On the contrary, by performing the calculation of (S1-S2)-(S3-S4), 2 (Sy + Sz) -2 (Sy-Sz) = 4Sz, and the signal Sz caused by the angular velocity ωz can be separated. Thereby, the angular velocity ωz is obtained. Thus, according to the resonator element 1, the angular velocity ωy and the angular velocity ωz can be detected independently. In particular, the signal obtained from the detection arm 221 is doubled using the first and second detection signals S1 and S2, and the signal obtained from the detection arm 222 is doubled using the third and fourth detection signals S3 and S4. Therefore, the detection sensitivity of the angular velocity ωy and the angular velocity ωz is improved.
The method for detecting the angular velocity ωy and the angular velocity ωz has been described above.

  In such a resonator element 1, it is preferable that the Q value of the driving vibration mode is sufficiently high in order to easily excite the driving vibration mode. On the other hand, in order to detect the angular velocity ωy and the angular velocity ωz with higher accuracy, it is preferable to sufficiently reduce the Q value of the detection vibration mode (Y-axis detection vibration mode and Z-axis detection vibration mode). This is because when the Q value of the detection vibration mode is high, for example, the difference between the frequency of the detection vibration mode (the bending vibration frequency of the detection arms 221 and 222) and the detuning frequency (the frequency of the drive vibration mode and the frequency of the detection vibration mode). This is because the detection vibration mode is easily excited when a disturbance having a frequency substantially equal to) is received, which becomes noise and reduces the detection accuracy of the angular velocities ωy and ωz.

  To explain with a specific example, for example, when the resonator element 1 is incorporated in a car navigation device, various disturbances are received, and thus such disturbances may coincide with the detuning frequency. is there. Then, the detection vibration mode is excited by the disturbance, the noise component is increased, and the detection accuracy of the angular velocities ωy and ωz is lowered.

  Therefore, in the resonator element 1, the adjustment arms 251 to 254 are arranged to lower the Q value in the detection vibration mode as compared with the case where the adjustment arms 251 to 254 are not provided. This will be described in detail below. Since the adjustment arms 251 and 252 that make a pair with the detection arm 221 and the adjustment arms 253 and 254 that make a pair with the detection arm 222 have the same configuration, the adjustment arms 251 and 252 will be representatively described below. Description of the adjustment arms 253 and 254 will be omitted.

  When the Q value of the detection arm 221 is Q1 and the Q value of the adjustment arms 251 and 252 is Q2, Q1 and Q2 are different from each other, and in this embodiment, the relationship of Q1> Q2 is satisfied. . In other words, the thermoelastic loss of the adjustment arms 251 and 252 is larger than the thermoelastic loss of the detection arm 221. Thus, the adjustment arms 251 and 252 are provided by making the Q value Q2 of the adjustment arms 251 and 252 that vibrate in combination with the detection arm 221 in the detection vibration mode lower than the Q value Q1 of the detection arm 221. The Q value of the detection vibration mode can be lowered as compared with the case where it is not. Therefore, the erroneous excitation of the detection vibration mode due to the disturbance as described above is reduced, and the detection accuracy of the angular velocities ωy and ωz is increased.

  Here, the “thermoelastic loss” will be briefly described. When the arms 221, 251, and 252 are bent and vibrated in the X-axis direction, when one side surface contracts, the other side surface expands. When stretched, the other side shrinks. Then, the temperature on the side surface that contracts increases and the temperature on the side surface that expands decreases, so that a temperature difference occurs between both side surfaces, that is, inside the arms 221, 251, and 252. Loss of vibration energy occurs due to heat transfer (thermal conduction) resulting from such a temperature difference, and this loss of energy is called thermoelastic loss.

  The relationship between Q1 and Q2 is not particularly limited as long as the relationship of Q1> Q2 described above is satisfied, but it is further preferable that the relationship of Q1 / 5> Q2 is satisfied. By satisfying such a relationship, the erroneous excitation of the detection vibration mode due to the above-described disturbance is further reduced, and the detection accuracy of the angular velocities ωy and ωz is further increased. Note that specific numerical values of Q1 and Q2 are not particularly limited. For example, Q1 can be about 10,000 and Q2 can be about 1000. Thereby, the Q value of the detection vibration mode becomes a value more suitable for exhibiting the above effect.

Here, if the thermal natural frequency of the vibrating arm is f0, the thermal natural frequency f0 can be obtained by f0 = (π · k) / (2 · ρ · Cp · t 2 ) (1). In Equation (1), π is the circularity ratio, k is the thermal conductivity of the vibrating arm in the vibration direction, ρ is the mass density of the vibrating arm, Cp is the heat capacity of the vibrating arm, and t is the width of the vibrating arm in the vibration direction. It is. Then, by inputting (substituting) constants of the material of the vibrating arm itself (that is, crystal) into k, ρ, and Cp, the thermal natural frequency f0 of the vibrating arm can be obtained.

  When t in equation (1) is the width W1 in the vibration direction of the adjusting arms 251 and 252 (width in the X-axis direction), the thermal natural frequency f0 is f1, and the frequency of the detected vibration mode is fd. The graph of FIG. 7 shows the fd / f1 dependence of the Q value Q2. In the figure, the region of fd / f1 <1 is also referred to as an isothermal region. In this isothermal region, the Q value Q2 increases as fd / f1 decreases. This is because the temperature difference in the arm as described above is less likely to occur as fd becomes lower. Therefore, in the limit when fd / f1 is as close as possible to 0 (zero), the operation is an isothermal quasi-static operation, and the thermoelastic loss approaches 0 (zero) as much as possible. On the other hand, the region of fd / f1> 1 is also referred to as an adiabatic region. In this adiabatic region, the Q value Q2 increases as fd / f1 increases. This is because as fd becomes higher, the temperature rise and temperature change on each side surface becomes faster and there is no time for heat transfer as described above. Therefore, in the limit when fd / f1 is increased as much as possible, the operation becomes adiabatic, and the thermoelastic loss approaches 0 (zero) as much as possible. When fd / f1 = 1 (when at the boundary between the isothermal region and the adiabatic region), the Q value Q2 is the smallest. Therefore, in order to sufficiently reduce the Q value Q2 and effectively reduce the Q value of the detection vibration mode, it is preferable to satisfy the relationship 0.1 <fd / f1 <10, and 0.5 <fd It is more preferable to satisfy the relationship / f1 <5.

  An example of the specific dimension of the width W1 of the adjustment arm 251 when the relationship 0.1 <fd / f1 <10 is satisfied will be described. Since the adjustment arm 251 is made of quartz, K = 10, ρ = 2600, and Cp = 750. When fd = 120 kHz, 12 kHz <f1 <1200 kHz, and 2.6 μm <W1 <26 μm.

  Further, when t in the equation (1) is the width W2 of the detection arm 221 (arm portion 221A) in the vibration direction (width in the X-axis direction), the thermal natural frequency f0 is f2, and the frequency of the detection vibration mode is fd. It is preferable that fd / f2 be in the adiabatic region (region where fd / f2> 1). Thereby, for example, compared with the case where fd / f2 is in the isothermal region (region where fd / f2 <1), the frequency fd of the detection vibration mode when having the same Q value Q1 can be increased. Accordingly, the width W2 of the arm portion 221A can be increased. Therefore, the detection arm 221 and the first and second detection signal electrodes 33 and 34 can be easily formed.

  Further, when t in the equation (1) is the width W3 in the vibration direction of the drive arm 241 (arm portion 241A) (the width in the X-axis direction), the thermal natural frequency f0 is f3, and the frequency of the detected vibration mode is fd. It is preferable that the relationship 1 <fd / f1 <fd / f3 is satisfied, or the relationship fd / f3 <fd / f1 <1 is satisfied. Satisfying such a range can also sufficiently reduce the Q value of the detection vibration mode.

  The vibration piece 1 according to this embodiment has been described above. According to such a resonator element 1, the Q value in the detection vibration mode can be adjusted by the adjustment arms 251 to 254, and thus the Q value in the detection vibration mode can be easily adjusted. Further, since the Q value of the detection vibration mode does not have to be adjusted depending on the shape of the detection arms 221 and 222, the degree of freedom in designing the detection arms 221 and 222 is increased. Further, the adjustment arms 251 to 254 are not coupled with the vibrations of the drive arms 241 to 244 in the drive vibration mode. Therefore, the adjustment arms 251 to 254 do not lower the Q value in the driving vibration mode, and the Q value in the driving vibration mode can be kept high.

  In this embodiment, the adjustment arms 251 to 254 extend in the Y-axis direction and are arranged in parallel with the detection arms 221 and 222. However, as the extension direction of the adjustment arms 251 to 254, the adjustment arm 251 is used. ˜254 can be combined with the vibrations of the detection arms 221 and 222, and is not particularly limited, and may extend in a direction inclined with respect to the Y axis.

  In the present embodiment, the second and fourth detection signal electrodes 34 and 36 are arranged on the detection arms 221 and 222, and the second and fourth detection signal S2 are provided from the second and fourth detection signal electrodes 34 and 36. , S4, but instead of the second detection signal electrode 34, a first detection ground electrode serving as a ground (reference potential) is arranged with respect to the first detection signal electrode 33, and the fourth detection signal electrode 36 is obtained. Instead, a second detection ground electrode that serves as a ground (reference potential) with respect to the third detection signal electrode 35 may be disposed. In this case, the angular velocities ωy and ωz may be detected by the first and third detection signals S1 and S3.

  In the present embodiment, the drive arms 241 to 244 vibrate in an oblique direction including the X-axis component and the Z-axis component. However, the step portions 2413, 2414, 2423, and 2424 from the drive arms 241 to 244 are configured. , 2433, 2434, 2443, 2444 may be omitted and the drive arms 241 to 244 may be vibrated in the X-axis direction. In this case, the resonator element 1 can detect only the angular velocity ωz around the Z axis.

Second Embodiment
FIG. 8 is a perspective view of a resonator element according to the second embodiment of the invention.

  Hereinafter, the resonator element according to the second embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted.

  The resonator element of the second embodiment is mainly the same as the resonator element of the first embodiment described above except that the configuration of the adjustment arm is different. In FIG. 8, the same reference numerals are given to the same components as those in the above-described embodiment.

  In the resonator element 1 of the present embodiment, as shown in FIG. 8, a coating film 39 made of a metal film is disposed on the adjustment arms 251 to 254. Since such a coating film 39 is excellent in thermal conductivity, the heat transfer in the adjusting arms 251 to 254 can be promoted, and the thermoelastic loss of the adjusting arms 251 to 254 can be increased. The Q value of the adjustment arms 251 to 254 can be further lowered. Therefore, the Q value of the detection vibration mode can be further reduced.

  Such a coating film 39 can be formed together with the signal electrode. That is, by forming a metal film on the surface of the vibrating body 2 and patterning the metal film using a photolithography technique and an etching technique, the signal electrode and the covering film 39 can be formed at a time. The coating film 39 may be connected to any one of the drive signal electrode 31, the drive ground electrode 32, and the first to fourth detection signal electrodes 33 to 36, for example. Even if it is connected to any one of the electrodes, a pair of electrodes is not arranged. Therefore, if the adjustment arms 251 to 254 do not vibrate like the drive arms 241 to 244, the adjustment arms 251 to 224 generate Coriolis force like the detection arms 221 and 222. This is because the detection signal based on this is not taken out.

  Also according to the second embodiment, the same effects as those of the first embodiment described above can be exhibited.

<Third Embodiment>
FIG. 9 is a perspective view of a resonator element according to the third embodiment of the invention. FIG. 10 is a cross-sectional view taken along the line CC in FIG. FIG. 11 is a schematic diagram illustrating a vibration state of the resonator element illustrated in FIG. 9. FIG. 12 is a graph showing the relationship between the Q value and fr / f4.

  Hereinafter, the resonator element according to the third embodiment will be described mainly with respect to differences from the above-described embodiment, and description of similar matters will be omitted.

  The vibrating piece 4 shown in FIG. 9 is not a vibrating piece for detecting a physical quantity like the vibrating piece 1 of the first embodiment described above, but is a vibrating piece used for an oscillator, for example.

  Such a vibrating piece 4 includes a vibrating body 5 and a signal electrode disposed on the vibrating body 5. The vibrating body 5 is formed by patterning a Z-cut quartz plate. However, the cut angle of the crystal is not particularly limited as long as the object can be achieved, and for example, the Z axis may be slightly shifted with respect to the thickness direction of the vibrating body 5. In addition, the constituent material of the vibrating body 5 is not limited to quartz, and for example, piezoelectric materials other than quartz such as lithium tantalate, lithium niobate, lithium borate, and barium titanate may be used.

  Such a vibrating body 5 includes a base 51, a pair of vibrating arms (first vibrating arms) 521 and 522 extending from the base 51 toward the + Y axis direction, and extending from the base 51 toward the + Y axis direction. And a pair of adjusting arms (second vibrating arms) 531 and 532. These four arms 521, 522, 531, and 532 are arranged side by side in the X-axis direction, and the vibrating arms 521 and 522 are arranged between the adjustment arms 531 and 532. According to such a configuration, the arms 521, 522, 531, and 532 can be arranged with good balance, and thus the vibrating body 2 can be vibrated with good balance.

  As shown in FIG. 10, a groove 5211 extending in the Y-axis direction is formed on the upper surface of the vibrating arm 521, and a groove 5212 extending in the Y-axis direction is formed on the lower surface of the vibrating arm 521. Similarly, a groove portion 5221 extending in the Y-axis direction is formed on the upper surface of the vibrating arm 522, and a groove portion 5222 extending in the Y-axis direction is formed on the lower surface of the vibrating arm 522.

  The adjustment arms 531 and 532 are arms for adjusting the Q value of the resonator element 4. The adjusting arms 531 and 532 are arranged with the vibrating arms 521 and 522 interposed therebetween, and vibrate in combination with the vibration of the vibrating arms 521 and 522.

  In addition, the adjustment arms 531 and 532 have substantially the same width W4 across the entire area, and the width W4 is smaller than the width W5 of the vibrating arms 521 and 522. Further, the length L4 of the adjusting arms 531 and 532 is shorter than the length L5 of the vibrating arms 521 and 522. As described above, by making the adjustment arms 531 and 532 smaller than the vibration arms 521 and 522, it is possible to reduce the size of the vibration piece 4.

  Next, the signal electrode disposed on the vibrating body 5 will be described. As shown in FIG. 10, the signal electrode disposed on the vibrating body 5 includes a drive signal electrode 61 and a drive ground electrode 62.

  The drive signal electrode 61 is disposed on the upper and lower surfaces (in the grooves 5211 and 5212) of the vibrating arm 521 and on both side surfaces of the vibrating arm 522. Such a drive signal electrode 61 is an electrode for applying a drive signal for driving and vibrating the vibrating arms 521 and 522.

  The drive ground electrode 62 is disposed on both side surfaces of the vibrating arm 521 and the upper and lower surfaces (in the groove portions 5221 and 5222) of the vibrating arm 522. Such a drive ground electrode 62 is an electrode that serves as a ground (reference potential) with respect to the drive signal electrode 61.

  Such signal electrodes (the drive signal electrode 61 and the drive ground electrode 62) are not disposed on the adjustment arms 531 and 532. That is, the adjustment arms 531 and 532 are vibration arms that do not vibrate like the vibration arms 521 and 522 and are used only to adjust the Q value of the resonator element 4.

  When a drive signal is applied to the drive signal electrode 61, the vibrating arms 521 and 522 vibrate as shown in FIG. Specifically, the vibrating arms 521 and 522 respectively bend and vibrate in mutually opposite phases in the X-axis direction. Further, coupled with the vibrations of the vibrating arms 521 and 522, the adjusting arms 531 and 532 are flexibly vibrated in mutually opposite phases in the X-axis direction. According to such vibration, vibration balance is good and vibration leakage can be reduced. It is preferable to set the bending vibration frequency of the adjustment arms 531 and 532 to be substantially equal to the bending vibration frequency of the vibration arms 521 and 522 so that the adjustment arms 531 and 532 can be easily coupled with the vibration of the vibration arms 521 and 522.

  In such a vibrating piece 4, it is preferable to make the Q value of the vibrating piece 4 sufficiently high in order to easily excite the vibrating arms 521 and 522. Therefore, in the resonator element 4, the adjustment arms 531 and 532 are arranged so that the Q value of the resonator element 4 is increased as compared with the case where the adjustment arms 531 and 532 are not provided. This will be described in detail below.

  When the Q value of the vibrating arms 521 and 522 is Q1, and the Q value of the adjusting arms 531 and 532 is Q2, Q1 and Q2 are different from each other. In this embodiment, the relationship of Q1 <Q2 is satisfied. ing. In this way, by adjusting the Q value Q2 of the adjusting arms 531 and 532 that vibrate in combination with the vibrating arms 521 and 522 to be higher than the Q value Q1 of the vibrating arms 521 and 522, the adjusting arms 531 and 522 are not provided. Compared to the case, the Q value of the resonator element 4 can be increased. Therefore, it becomes easy to excite the drive vibration mode.

  The relationship between Q1 and Q2 is not particularly limited as long as the relationship of Q1 <Q2 described above is satisfied, but it is preferable that the relationship of 5 · Q1 <Q2 is satisfied. Satisfying such a relationship makes it easier to excite the resonator element 4. Specific numerical values of Q1 and Q2 are not particularly limited. For example, Q1 can be about 30000 and Q2 can be about 100000.

  Here, as described in the first embodiment, the thermal natural frequency f0 of the vibrating arm can be obtained by Expression (1). The thermal natural frequency f0 when t in the formula (1) is the width W4 in the vibration direction of the adjusting arms 531 and 532 (the width in the X-axis direction) is f4, and the oscillation frequency of the resonator element 4 is fr. FIG. 12 shows the fr / f4 dependence of the Q value Q2 at that time. In order to increase the Q value Q2 sufficiently and effectively increase the Q value of the resonator element 4, it is preferable to satisfy the relationship fr / f4 <0.1 in the isothermal region, and fr / f4 < It is more preferable to satisfy the relationship of 0.01. In the adiabatic region, it is preferable to satisfy the relationship fr / f4> 10, and it is more preferable to satisfy the relationship fr / f4> 100. However, since the adjusting arms 531 and 532 can be made smaller in the isothermal region, it is particularly preferable to use the isothermal region.

  An example of the specific dimension of the width W4 of the adjustment arms 531 and 532 when the relationship fr / f4 <0.1 is satisfied will be described. Since the adjustment arms 531 and 532 are made of quartz, K = 10, ρ = 2600, and Cp = 750. When fr = 32 kHz, f4 <320 kHz and W4 <5 μm.

  Further, when t in the equation (1) is the width W5 (width in the X-axis direction) of the vibrating arms 521 and 522, the thermal natural frequency f0 is f5, and the oscillation frequency is fr, fr / f4 <fr It is preferable that the relationship / f5 <1 is satisfied. Satisfying such a range can also sufficiently increase the Q value of the drive vibration mode.

  Also according to the third embodiment, the same effects as those of the first embodiment described above can be exhibited.

<Fourth embodiment>
FIG. 13 is a perspective view of a resonator element according to the fourth embodiment of the invention. FIG. 14 is a schematic diagram illustrating a driving state of the resonator element illustrated in FIG. 13. In the following, for convenience of explanation, the three axes orthogonal to each other are referred to as an x-axis, a y-axis, and a z-axis, the direction along the x-axis is also referred to as the “x-axis direction”, and the direction along the y-axis is referred to as the “y-axis”. The direction along the z-axis is also referred to as the “z-axis direction”. Further, the + z axis side is also referred to as “upper”, and the −z axis side is also referred to as “lower”.

  Hereinafter, the resonator element according to the fourth embodiment will be described mainly with respect to differences from the above-described embodiment, and description of similar matters will be omitted.

  A vibrating piece 7 shown in FIG. 13 includes a vibrating body 8 made of silicon and a piezoelectric element disposed on the vibrating body 8. The vibrating body 8 extends from the base 81, a pair of vibrating arms (first vibrating arms) 821 and 822 extending from the base 81 toward the + y axis, and from the base 81 toward the + y axis. A pair of adjusting arms (second vibrating arms) 831 and 832. These four arms 821, 822, 831, and 832 are arranged side by side in the x-axis direction, and the vibrating arms 821 and 822 are arranged between the adjustment arms 831 and 832.

  The adjustment arms 831 and 832 are arms for adjusting the Q value of the resonator element 7. The adjusting arms 831 and 832 are disposed with the vibrating arms 821 and 822 interposed therebetween, and vibrate in combination with the vibration of the vibrating arms 821 and 822. Further, the adjustment arms 831 and 832 have substantially the same width W6 across the entire area, and the width W6 is smaller than the width W7 of the vibrating arms 821 and 822. Further, the length L6 of the adjusting arms 831 and 832 is shorter than the length L7 of the vibrating arms 821 and 822. As described above, by making the adjustment arms 831 and 832 smaller than the vibrating arms 821 and 822, it is possible to reduce the size of the vibrating piece 7.

  The piezoelectric elements are a pair of piezoelectric elements 91 and 92 arranged in the x-axis direction on the upper surface of the vibrating arm 821, and a pair of piezoelectric elements 93 and 94 arranged in the x-axis direction on the upper surface of the vibrating arm 822. And have. These piezoelectric elements 91 to 94 have a configuration in which a piezoelectric body is sandwiched between a pair of electrodes, and can expand and contract in the y-axis direction.

  Therefore, the piezoelectric elements 91 and 94 are expanded while the piezoelectric elements 92 and 93 are contracted, and the piezoelectric elements 91 and 94 are contracted while the piezoelectric elements 92 and 93 are expanded. By applying a driving voltage to the elements 91 to 94, as shown in FIG. 14, the vibrating arms 821 and 822 bend and vibrate in mutually opposite phases in the x-axis direction. Further, in combination with the vibrations of the vibrating arms 821 and 822, the adjusting arms 831 and 832 bend and vibrate in mutually opposite phases in the X-axis direction.

  In such a vibrating piece 7, it is preferable to make the Q value of the vibrating piece 7 sufficiently high in order to easily excite the bending vibration. Therefore, in the resonator element 7, the adjustment arms 831 and 832 are arranged so that the Q value of the resonator element 7 is increased as compared with the case where the adjustment arms 831 and 832 are not provided.

  When the Q value of the vibrating arms 821 and 822 is Q1, and the Q value of the adjusting arms 831 and 832 is Q2, Q1 and Q2 are different from each other. In this embodiment, the relationship of Q1 <Q2 is satisfied. ing. Thereby, the Q value of the resonator element 7 can be increased as compared with the case where the adjusting arms 831 and 822 are not provided. Since the relationship between Q1 and Q2 is the same as that in the third embodiment described above, detailed description thereof is omitted.

  According to the fourth embodiment, the same effect as that of the first embodiment described above can be exhibited.

[Vibration device]
Next, a vibration device including the resonator element according to the invention will be described.

  FIG. 15 is a cross-sectional view of a physical quantity detection apparatus to which the vibration device of the present invention is applied. FIG. 16 is a block diagram of the physical quantity detection device shown in FIG.

  The physical quantity detection device 100 of the present embodiment is a physical quantity detection device that can detect angular velocity. As shown in FIG. 15, the physical quantity detection device 100 has a vibrating piece 1, an IC 130, and a package 10 that houses the vibrating piece 1 and the IC 130. The package 10 includes a cavity-shaped base 11 and a lid 12 that closes the opening of the base 11, and an airtight space for accommodating the resonator element 1 and the IC 130 is formed inside the package 10. In this airtight space, the IC 130 is fixed to the base 11, and the resonator element 1 is fixed and electrically connected to the IC 130 via a conductive adhesive.

  As shown in FIG. 16, the IC 130 includes a drive circuit 110 for driving and vibrating the resonator element 1 and a detection circuit 120 for detecting the detected vibration of the resonator element 1 when an angular velocity is applied. Yes. Note that the drive circuit 110 and the detection circuit 120 may be realized by a one-chip IC 130 as in the present embodiment, or may be realized by separate IC chips.

  The drive circuit 110 includes an I / V conversion circuit (current / voltage conversion circuit) 111, an AC amplification circuit 112, and an amplitude adjustment circuit 113. The drive circuit 110 is a circuit that outputs a signal for driving the drive arms 241 to 244 to the drive signal electrode 31 of the resonator element 1 and a signal output from the drive ground electrode 32 of the resonator element 1.

  When the drive arms 241 to 244 of the resonator element 1 vibrate, an alternating current based on the piezoelectric effect is output from the drive ground electrode 32 and input to the I / V conversion circuit 111. The I / V conversion circuit 111 converts the input AC current into an AC voltage signal having the same frequency as the vibration frequency of the drive arms 241 to 244 and outputs the AC voltage signal. The AC voltage signal output from the I / V conversion circuit 111 is input to the AC amplifier circuit 112. The AC amplifier circuit 112 amplifies and outputs the input AC voltage signal.

  The AC voltage signal output from the AC amplifier circuit 112 is input to the amplitude adjustment circuit 113. The amplitude adjustment circuit 113 controls the gain so as to hold the amplitude of the input AC voltage signal at a constant value, and outputs the AC voltage signal after gain control to the drive signal electrode 31 of the resonator element 1. The drive arms 241 to 244 vibrate in the drive vibration mode by the AC voltage signal (drive signal) input to the drive signal electrode 31.

  The detection circuit 120 includes charge amplifiers 121a, 121b, 121c, and 121d, subtraction processing circuits 122 and 123, a Y-axis angular velocity detection unit 124, and a Z-axis angular velocity detection unit 125. The detection circuit 120 is a circuit that detects the angular velocity ωy and the angular velocity ωz based on signals respectively output from the first to fourth detection signal electrodes 33 to 36 of the vibrating piece 1.

  The charge amplifier 121a (first current / voltage conversion unit) includes an operational amplifier, a feedback resistor, and a feedback capacitor. The second input of the detection arm 221 is connected to the inverting input terminal (− terminal) of the operational amplifier. The second detection signal S2 output from the detection signal electrode 34 is input, and the non-inverting input terminal (+ terminal) of this operational amplifier is fixed to the reference potential. The charge amplifier 121a converts the detection signal input to the operational amplifier into an AC voltage signal.

The charge amplifier 121b (second current / voltage converter) includes an operational amplifier, a feedback resistor, and a feedback capacitor. The first input of the detection arm 221 is connected to the inverting input terminal (− terminal) of the operational amplifier. The first detection signal S1 output from the detection signal electrode 33 is input, and the non-inverting input terminal (+ terminal) of this operational amplifier is fixed to the reference potential. The charge amplifier 121b converts the detection signal input to the operational amplifier into an AC voltage signal.
The first and second detection signals S1 and S2 have opposite electrical characteristics.

  The output signal of the charge amplifier 121 a and the output signal of the charge amplifier 121 b are input to a subtraction processing circuit (differential amplifier circuit) 122. The subtraction processing circuit 122 functions as a differential amplification unit that differentially amplifies the output signal of the resonator element 1, and a signal obtained by amplifying (differential amplification) the potential difference between the output signal of the charge amplifier 121 a and the output signal of the charge amplifier 121 b. Is output. The output signal S ′ of the subtraction processing circuit 122 is input to the Y-axis angular velocity detection unit 124 and the Z-axis angular velocity detection unit 125.

  The charge amplifier 121c (third current / voltage conversion unit) includes an operational amplifier, a feedback resistor, and a feedback capacitor. The third input of the detection arm 222 is connected to the inverting input terminal (− terminal) of the operational amplifier. The third detection signal S3 output from the detection signal electrode 35 is input, and the non-inverting input terminal (+ terminal) of this operational amplifier is fixed to the reference potential. The charge amplifier 121c converts the detection signal input to the operational amplifier into an AC voltage signal.

The charge amplifier 121d (fourth current / voltage conversion unit) includes an operational amplifier, a feedback resistor, and a feedback capacitor. The fourth input of the detection arm 222 is connected to the inverting input terminal (− terminal) of the operational amplifier. The fourth detection signal S4 output from the detection signal electrode 36 is input, and the non-inverting input terminal (+ terminal) of this operational amplifier is fixed to the reference potential. The charge amplifier 121d converts the detection signal input to the operational amplifier into an AC voltage signal.
Note that the third and fourth detection signals S3 and S4 have opposite electrical characteristics.

  The output signal of the charge amplifier 121c and the output signal of the charge amplifier 121d are input to a subtraction processing circuit (differential amplifier circuit) 123. The subtraction processing circuit 123 functions as a differential amplification unit that differentially amplifies the output signal of the resonator element 1, and a signal obtained by amplifying (differential amplification) the potential difference between the output signal of the charge amplifier 121 c and the output signal of the charge amplifier 121 d. Is output. The output signal S ″ of the subtraction processing circuit 123 is input to the Y axis angular velocity detection unit 124 and the Z axis angular velocity detection unit 125.

  The Y-axis angular velocity detection unit 124 includes an addition processing circuit 1241, an AC amplification circuit 1242, a synchronous detection circuit 1243, a smoothing circuit 1244, a variable amplification circuit 1245, and a filter circuit 1246.

  The output signal S ′ of the subtraction processing circuit 122 and the output signal S ″ of the subtraction processing circuit 123 are input to the addition processing circuit 1241. The addition processing circuit 1241 adds and amplifies the output signal of the resonator element 1. Functions as a unit, adds the potentials of the output signal S ′ of the subtraction processing circuit 122 and the output signal S ″ of the subtraction processing circuit 123, and outputs an amplified signal. The output signal of the addition processing circuit 1241 is input to the AC amplification circuit 1242.

  The AC amplifying circuit 1242 functions as an AC amplifying unit that amplifies the AC signal, and outputs a signal obtained by amplifying the output signal of the addition processing circuit 1241. The output signal of the AC amplifier circuit 1242 is input to the synchronous detection circuit 1243. The synchronous detection circuit 1243 extracts an angular velocity component around the Y axis by synchronously detecting the output signal of the AC amplifier circuit 112 based on the AC voltage signal output from the AC amplifier circuit 112 of the drive circuit 110.

  The signal of the angular velocity component around the Y axis extracted by the synchronous detection circuit 1243 is smoothed into a DC voltage signal by the smoothing circuit 1244 and input to the variable amplifier circuit 1245. The variable amplifier circuit 1245 amplifies (or attenuates) the output signal (DC voltage signal) of the smoothing circuit 1244 with a set amplification factor (or attenuation factor) to change the angular velocity sensitivity. The signal amplified (or attenuated) by the variable amplifier circuit 1245 is input to the filter circuit 1246.

  The filter circuit 1246 removes high-frequency noise components outside the sensor band from the output signal of the variable amplifier circuit 1245 (more precisely, attenuates to a predetermined level or less), and the polarity according to the direction and magnitude of the angular velocity around the Y axis. And a voltage level detection signal. This detection signal is output to the outside from an external output terminal (not shown).

  The Z-axis angular velocity detection unit 125 includes a subtraction processing circuit 1251, an AC amplification circuit 1252, a synchronous detection circuit 1253, a smoothing circuit 1254, a variable amplification circuit 1255, and a filter circuit 1256.

  The output signal S ′ of the subtraction processing circuit 122 and the output signal S ″ of the subtraction processing circuit 123 are input to the subtraction processing circuit 1251. The subtraction processing circuit 1251 differentially amplifies the output signal of the resonator element 1. And outputs a signal obtained by amplifying (differential amplification) the potential difference between the output signal S ′ of the subtraction processing circuit 122 and the output signal S ″ of the subtraction processing circuit 123. The output signal of the subtraction processing circuit 1251 is input to the AC amplification circuit 1252.

  The AC amplification circuit 1252 functions as an AC amplification unit that amplifies the AC signal, and outputs a signal obtained by amplifying the output signal of the subtraction processing circuit 1251. An output signal of the AC amplifier circuit 1252 is input to the synchronous detection circuit 1253. The synchronous detection circuit 1253 extracts an angular velocity component around the Z axis by synchronously detecting the output signal of the AC amplifier circuit 1252 based on the AC voltage signal output from the AC amplifier circuit 112 of the drive circuit 110.

  The signal of the angular velocity component around the Z axis extracted by the synchronous detection circuit 1253 is smoothed into a DC voltage signal by the smoothing circuit 1254 and input to the variable amplifier circuit 1255. The variable amplifier circuit 1255 amplifies (or attenuates) the output signal (DC voltage signal) of the smoothing circuit 1254 at a set amplification factor (or attenuation factor) to change the angular velocity sensitivity. The signal amplified (or attenuated) by the variable amplifier circuit 1255 is input to the filter circuit 1256.

  The filter circuit 1256 removes high-frequency noise components outside the sensor band from the output signal of the variable amplifier circuit 1255 (more precisely, attenuates to a predetermined level or less), and the polarity according to the direction and magnitude of the angular velocity around the Z axis. And a voltage level detection signal. This detection signal is output to the outside from an external output terminal (not shown).

  Such a physical quantity detection device 100 includes the resonator element 1 and thus has excellent reliability.

  Note that the vibration device of the present invention is not limited to the physical quantity detection device of FIG. 16, and may be, for example, an oscillator having the resonator element 4 and an oscillation circuit that oscillates the resonator element 4.

[Electronics]
Next, an electronic device including the resonator element according to the invention will be described.
FIG. 17 is a perspective view showing the configuration of a mobile (or notebook) personal computer to which the electronic apparatus of the present invention is applied.

  In this figure, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 1108. The display unit 1106 is rotated with respect to the main body portion 1104 via a hinge structure portion. It is supported movably. Such a personal computer 1100 incorporates the resonator element 1.

  FIG. 18 is a perspective view showing a configuration of a mobile phone (including PHS) to which the electronic apparatus of the invention is applied.

  In this figure, a cellular phone 1200 includes an antenna (not shown), a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 1208 is provided between the operation buttons 1202 and the earpiece 1204. Has been placed. Such a cellular phone 1200 has the resonator element 1 built therein.

  FIG. 19 is a perspective view showing a configuration of a digital still camera to which the electronic apparatus of the present invention is applied.

A display unit 1310 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD. The display unit 1310 displays a subject as an electronic image. Function as. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302. When the photographer confirms the subject image displayed on the display unit 1310 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. Such a digital still camera 1300 incorporates, for example, the resonator element 1 used for camera shake correction.
Since such an electronic device includes the resonator element 1, the electronic device has excellent reliability.

  In addition to the personal computer of FIG. 17, the mobile phone of FIG. 18, and the digital still camera of FIG. 19, the electronic apparatus of the present invention includes, for example, a smartphone, a tablet terminal, a watch (including a smart watch), an inkjet discharge Wearable terminals such as devices (for example, inkjet printers), laptop personal computers, televisions, HMDs (head-mounted displays), video cameras, video tape recorders, car navigation devices, pagers, electronic notebooks (including those with communication functions), electronics Dictionary, calculator, electronic game device, word processor, workstation, video phone, security TV monitor, electronic binoculars, POS terminal, medical device (eg electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasound diagnostic device, electronic Insight ), Fish finders, various measurement devices, gauges (e.g., vehicle, aircraft, ship instruments), can be applied to a flight simulator or the like.

[Moving object]
Next, a moving body provided with the resonator element according to the invention will be described.
FIG. 20 is a perspective view showing an automobile to which the moving body of the present invention is applied.

  As shown in FIG. 20, the vehicle 1500 has a built-in vibrating piece 1. For example, the posture of the vehicle body 1501 can be detected by the vibrating piece 1. The detection signal of the vibration piece 1 is supplied to the vehicle body posture control device 1502, and the vehicle body posture control device 1502 detects the posture of the vehicle body 1501 based on the signal, and controls the stiffness of the suspension according to the detection result. The brakes of the individual wheels 1503 can be controlled. In addition, such posture control can be used by a biped robot or a radio controlled helicopter (including a drone). As described above, the vibrator element 1 is incorporated in realizing the posture control of various moving bodies.

  As described above, the resonator element, the vibration device, the electronic apparatus, and the moving body of the present invention have been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each part has the same function. Any configuration can be substituted. In addition, any other component may be added to the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Vibrating piece, 10 ... Package, 11 ... Base, 12 ... Lid, 2 ... Vibrating body, 21 ... Base part, 221, 222 ... Detection arm, 221A, 222A ... Arm part, 221B, 222B ... Wide part, 2211, 2122 , 2221, 222 ... groove, 231 232 ... connecting arm, 241, 242, 243, 244 ... driving arm, 241A, 242A, 243A, 244A ... arm, 241B, 242B, 243B, 244B ... wide part, 2411, 2412 , 2421, 2422, 2431, 2432, 2441, 2442 ... groove, 2413, 2414, 2423, 2424, 2433, 2434, 2443, 2444 ... stepped portion, 251, 252, 253, 254 ... adjustment arm, 31 ... drive signal electrode 32 ... Driving ground electrode, 33 ... First detection signal electrode, 34 ... Second detection signal electrode, DESCRIPTION OF SYMBOLS 5 ... 3rd detection signal electrode, 36 ... 4th detection signal electrode, 39 ... Coating film, 4 ... Vibrating piece, 5 ... Vibrating body, 51 ... Base, 521, 522 ... Vibrating arm, 5211, 5212, 5221, 5222 ... groove, 531, 532 ... adjustment arm, 61 ... drive signal electrode, 62 ... drive ground electrode, 7 ... vibrating piece, 8 ... vibrating body, 81 ... base, 821, 822 ... vibrating arm, 831,832 ... adjustment arm, 91, 92, 93, 94 ... piezoelectric element, 100 ... physical quantity detection device, 110 ... drive circuit, 111 ... I / V conversion circuit, 112 ... AC amplifier circuit, 113 ... amplitude adjustment circuit, 120 ... detection circuit, 121a, 121b 121c, 121d ... charge amplifiers, 122, 123 ... subtraction processing circuit, 124 ... Y-axis angular velocity detection unit, 1241 ... addition processing circuit, 1242 ... AC amplification circuit, 1243 ... synchronous detection circuit, 12 DESCRIPTION OF SYMBOLS 4 ... Smoothing circuit, 1245 ... Variable amplification circuit, 1246 ... Filter circuit, 125 ... Z-axis angular velocity detection part, 1251 ... Subtraction processing circuit, 1252 ... AC amplification circuit, 1253 ... Synchronous detection circuit, 1254 ... Smoothing circuit, 1255 ... Variable Amplifier circuit 1256 ... Filter circuit 130 ... IC 1100 Personal computer 1102 Keyboard 1104 Main body 1106 Display unit 1108 Display unit 1200 Mobile phone 1202 Operation buttons 1204 Earpiece 1206: Mouthpiece, 1208 ... Display, 1300 ... Digital still camera, 1302 ... Case, 1304 ... Light receiving unit, 1306 ... Shutter button, 1308 ... Memory, 1310 ... Display, 1500 ... Car, 1501 ... Car body, 1502 ... Car body attitude control device, 1503: Wheel, A, B, C, D, E, F ... Arrow, Jx, Jy ... Axis, Lx, Lz ... Centerline, S ', S "... Output signal, S1 ... First detection signal, S2 ... First 2 detection signals, S3 ... third detection signal, S4 ... fourth detection signal, ωy, ωyz, ωz ... angular velocity

Claims (14)

  1. The base,
    A first vibrating arm connected to the base;
    A signal electrode disposed on the first vibrating arm;
    A second vibrating arm connected to the base and oscillating in combination with the first vibrating arm;
    With
    The length of the second vibrating arm is smaller than the length of the first vibrating arm,
    The width of the second vibrating arm is smaller than the width of the first vibrating arm,
    A vibrating piece, wherein a Q value of the first vibrating arm and a Q value of the second vibrating arm are different.
  2. The resonator element according to claim 1,
    The Q value of the first vibrating arm is Q1,
    When the Q value of the second vibrating arm is Q2,
    A resonator element that satisfies the relationship of Q1> Q2.
  3. The resonator element according to claim 2,
    A resonator element that satisfies the relationship of Q1 / 5> Q2.
  4. The resonator element according to any one of claims 1 to 3,
    A drive unit that is connected to the base and vibrates;
    The first vibrating arm vibrates in accordance with an applied physical quantity,
    The signal electrode is a vibrating piece that is an electrode that acquires a detection signal generated by the detection signal.
  5. 5. The resonator element according to claim 1, wherein:
    Two second vibrating arms,
    A vibrating piece in which the first vibrating arm is disposed between the two second vibrating arms.
  6. The resonator element according to claim 1,
    The Q value of the first vibrating arm is Q1,
    When the Q value of the second vibrating arm is Q2,
    A resonator element that satisfies the relationship of Q1 <Q2.
  7. The resonator element according to claim 6,
    5. Vibration piece satisfying the relationship of Q1 <Q2.
  8. The resonator element according to claim 6 or 7,
    Two first vibrating arms,
    The two first vibrating arms are vibrating pieces that vibrate in opposite phases.
  9. The vibration piece according to any one of claims 6 to 8,
    Two second vibrating arms;
    The two second vibrating arms are vibrating pieces that vibrate in opposite phases.
  10. The resonator element according to any one of claims 1 to 9,
    The signal electrode is a vibrating piece that is not disposed on the second vibrating arm.
  11. The resonator element according to any one of claims 1 to 10,
    A vibration device comprising: a package for housing the vibration piece.
  12. The resonator element according to any one of claims 1 to 10,
    And a circuit connected to the resonator element.
  13.   An electronic device comprising the resonator element according to claim 1.
  14.   A moving body comprising the resonator element according to claim 1.
JP2015224541A 2015-11-17 2015-11-17 Vibration piece, vibration device, electronic apparatus and movable body Pending JP2017090398A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2015224541A JP2017090398A (en) 2015-11-17 2015-11-17 Vibration piece, vibration device, electronic apparatus and movable body

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2015224541A JP2017090398A (en) 2015-11-17 2015-11-17 Vibration piece, vibration device, electronic apparatus and movable body

Publications (1)

Publication Number Publication Date
JP2017090398A true JP2017090398A (en) 2017-05-25

Family

ID=58767966

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2015224541A Pending JP2017090398A (en) 2015-11-17 2015-11-17 Vibration piece, vibration device, electronic apparatus and movable body

Country Status (1)

Country Link
JP (1) JP2017090398A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019059187A1 (en) * 2017-09-21 2019-03-28 住友精密工業株式会社 Angular speed sensor

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019059187A1 (en) * 2017-09-21 2019-03-28 住友精密工業株式会社 Angular speed sensor

Similar Documents

Publication Publication Date Title
JP6315164B2 (en) Oscillation circuit, vibration device, electronic device, mobile body, vibration device adjusting method, and sensitivity adjustment circuit
JP5975601B2 (en) Detection circuit, physical quantity detection device, angular velocity detection device, integrated circuit device, and electronic apparatus
US9546869B2 (en) Vibrator element, method of manufacturing vibrator element, vibrator, electronic device, electronic apparatus and moving body
US9470711B2 (en) Physical quantity sensor and electronic apparatus
TW201221907A (en) Vibrator element, sensor unit, electronic apparatus, manufacturing method of vibrator element, and manufacturing method of sensor unit
CN103715987B (en) Oscillating circuit, conductor integrated circuit device, resonator device, electronic equipment
JP6020793B2 (en) Physical quantity sensor and electronic equipment
JP5838689B2 (en) Sensor element, sensor element manufacturing method, sensor device and electronic device
US8978472B2 (en) Gyro sensor, electronic apparatus, and method of manufacturing gyro sensor
JP5838695B2 (en) Sensor element, sensor element manufacturing method, sensor device and electronic device
JP5088540B2 (en) Detecting device, detecting method, and electronic device
CN103376101B (en) Gyrosensor and electronic equipment
US8511161B2 (en) Physical amount detecting device
JP3421720B2 (en) Angular velocity detection circuit
JP5970690B2 (en) Sensor element, sensor unit, electronic device, and sensor unit manufacturing method
JP6051885B2 (en) Vibration element, vibrator, oscillator, electronic device, and moving object
JP2016029773A (en) Vibration element, method for manufacturing vibration element, vibrator, electronic apparatus and mobile body
US9631926B2 (en) Vibration element, vibrator, vibration device, electronic device and moving object
JP2014215097A (en) Physical quantity detection circuit, physical quantity detection device, electronic apparatus, and mobile
JP2011193399A (en) Resonator element, resonator and piezoelectric device
US8001840B2 (en) Oscillation type gyro sensor, control circuit, electronic apparatus, and method of manufacturing an oscillation type gyro sensor
JP4668739B2 (en) Vibrating gyro
US9372084B2 (en) Gyro sensor, electronic apparatus, and mobile unit
US10079590B2 (en) Vibrator element, electronic device, electronic apparatus, moving object, and method of manufacturing vibrator element
JP2002228453A (en) Oscillatory gyro and temperature drift adjusting method therefor