JP2018080958A - Gyro sensor and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gyro sensor with which it is possible to obtain a desired vibration characteristic with regard to each detection axis.SOLUTION: A gyro sensor according to one embodiment of the present technology comprises an annular frame, a drive unit, a first detection unit, a plurality of pendulum units, a second detection unit, and a first vibration adjustment unit. The annular frame has a first principal surface and a second principal surface. The drive unit is provided on the first principal surface, and causes the frame to vibrate in plane parallel to the first principal surface. The first detection unit is provided on the first principal surface and detects an angular velocity around a first axis orthogonal to the first principal surface. The plurality of pendulum units are connected to the frame and vibrate in plane parallel to the principal surfaces synchronously with the vibration of the frame. The second detection unit is provided in the plurality of pendulum units and detects an angular velocity around an axis orthogonal to the first axis. The first vibration adjustment unit is provided in the inner circumferential edge and outer circumferential edge of the frame on the second principal surface, and includes a plurality of recesses.SELECTED DRAWING: Figure 9

Description

  The present technology relates to a gyro sensor capable of detecting angular velocities around three axes and an electronic device including the gyro sensor.

  Currently, motion sensors for detecting human movement are widely used mainly in mobile devices. Among them, gyro sensors that detect angular velocities have recently been reduced in size due to progress in MEMS (Micro Electro Mechanical Systems) technology, and various types of devices have been developed and commercialized.

  For example, Patent Document 1 discloses an angular velocity sensor capable of detecting angular velocities around three axes. The angular velocity sensor includes a rectangular ring-shaped frame having a main surface, a plurality of pendulum units protruding from the four corners of the frame toward the center of the frame, and a drive unit that fundamentally vibrates the frame in a plane parallel to the main surface. And have. The angular velocity sensor detects an angular velocity around an axis perpendicular to the main surface based on the deformation amount of the frame, and is parallel to the main surface based on the deformation amounts of the plurality of pendulum portions in a direction orthogonal to the main surface. An angular velocity about two axes is detected.

  On the other hand, in a gyro sensor manufactured by the MEMS process, desired vibration characteristics are often not obtained due to variation in element shape or asymmetry due to processing accuracy, and vibration adjustment of the vibration part is performed after the element is manufactured. It is common to implement. For example, Patent Document 2 discloses a technique for performing laser processing on a predetermined portion of a vibrator and adjusting the vibrator to a desired vibration characteristic.

Japanese Patent No. 4858662 JP 2012-18174 A

  The multi-axis gyro sensor described in Patent Document 1 has a plurality of vibrators corresponding to each detection axis in one sensor element. For this reason, when the vibration characteristics of one vibrator are adjusted, the vibration characteristics of other vibrators may be affected, and there is a problem that the vibration characteristics of the vibrator of each detection axis cannot be easily adjusted.

  In view of the circumstances as described above, an object of the present technology is to provide a gyro sensor capable of obtaining a desired vibration characteristic for each detection axis, and an electronic apparatus including the gyro sensor.

A gyro sensor according to an aspect of the present technology includes an annular frame, a drive unit, a first detection unit, a plurality of pendulum units, a second detection unit, and a first vibration adjustment unit. .
The annular frame has a first main surface and a second main surface opposite to the first main surface.
The drive unit is provided on the first main surface and vibrates the frame in a plane parallel to the first main surface.
The first detection unit is provided on the first main surface, and is based on a deformation amount in a plane parallel to the first main surface of the frame and is orthogonal to the first main surface. Detect the angular velocity around the axis.
The plurality of pendulum portions are connected to the frame and vibrate in a plane parallel to the main surface in synchronization with the vibration of the frame.
The second detection unit is provided in the plurality of pendulum units, and based on a deformation amount of the plurality of pendulum units in the first axial direction, an angular velocity about an axis orthogonal to the first axis is calculated. To detect.
The first vibration adjustment unit is provided on the inner peripheral edge and the outer peripheral edge of the second main surface, and includes a plurality of recesses.

  In the gyro sensor, the first vibration adjusting unit is for adjusting the vibration characteristics of the frame that detects the angular velocity around the first axis. By providing the first vibration adjustment unit at the inner and outer peripheral edges of the frame, not only the vibration characteristics of the frame but also the vibration characteristics of a plurality of pendulum parts that vibrate in synchronization with the frame are adjusted in coordination. It becomes possible to do. Thereby, compared with the case where each pendulum part is adjusted individually, the coordinated vibration characteristic of a flame | frame and each pendulum part becomes easy, and the desired vibration characteristic about each detection axis can be obtained.

The frame may include a first set of beams, a second set of beams, and a plurality of connecting portions. The first set of beams extends in a second axial direction orthogonal to the first axis, and faces each other in a third axial direction orthogonal to the first axis and the second axis. To do. The pair of second beams extends in the third axial direction and opposes each other in the second axial direction. The plurality of connection portions connect between the first beam and the second beam, and support one end of the plurality of pendulum portions.
In this case, the first vibration adjusting unit is provided in at least one of the first beam set and the second beam set.

The gyro sensor may further include a second vibration adjustment unit. The second vibration adjustment unit is provided with each of the plurality of pendulum units and includes a plurality of recesses.
Thereby, not only a frame but the vibration characteristic of each pendulum part can be adjusted.

The second vibration adjustment unit may be provided at a location corresponding to each of the plurality of pendulum units.
In addition, the second vibration adjusting unit may be provided at a symmetrical position with respect to the center in the width direction of each of the plurality of pendulum units.
Furthermore, the second vibration adjusting unit may be provided on three or more virtual lines that are symmetrical with respect to the center in the length direction of each of the plurality of pendulum units.
Thereby, vibration adjustment of a plurality of pendulum parts can be performed individually, and vibration characteristics of each pendulum part can be adjusted cooperatively.

  The gyro sensor may further include an annular base portion, a plurality of connecting portions, and a third vibration adjusting portion. The annular base portion is disposed around the frame. The plurality of connecting portions are provided between the frame and the base portion, and support the frame so as to vibrate with respect to the base portion. The third vibration adjustment unit is provided in each of the plurality of coupling units, and includes a plurality of recesses.

The plurality of recesses may have circular openings and be arranged at intervals from each other.
The interval may be larger than the opening diameter of the opening.

An electronic apparatus according to an embodiment of the present technology includes a gyro sensor.
The gyro sensor includes an annular frame, a drive unit, a first detection unit, a plurality of pendulum units, a second detection unit, and a first vibration adjustment unit.
The annular frame has a first main surface and a second main surface opposite to the first main surface.
The drive unit is provided on the first main surface and vibrates the frame in a plane parallel to the first main surface.
The first detection unit is provided on the first main surface, and is based on a deformation amount in a plane parallel to the first main surface of the frame and is orthogonal to the first main surface. Detect the angular velocity around the axis.
The plurality of pendulum portions are connected to the frame and vibrate in a plane parallel to the main surface in synchronization with the vibration of the frame.
The second detection unit is provided in the plurality of pendulum units, and based on a deformation amount of the plurality of pendulum units in the first axial direction, an angular velocity about an axis orthogonal to the first axis is calculated. To detect.
The first vibration adjustment unit is provided on the inner peripheral edge and the outer peripheral edge of the second main surface, and includes a plurality of recesses.

As described above, according to the present technology, desired vibration characteristics can be obtained for each detection axis.
Note that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is a perspective view showing a gyro sensor concerning one embodiment of this art. It is a schematic perspective view which shows one structural example of the sensor element in the said gyro sensor. It is a top view which shows typically the structure of the vibrator main body in the said sensor element. It is a schematic diagram which shows the time change of the fundamental vibration of the flame | frame in the said vibrator body. It is a schematic diagram showing a vibration mode when an angular velocity around the Z axis acts on the vibrator body. It is a schematic diagram showing a vibration mode when an angular velocity around the X axis acts on the vibrator body. It is a schematic diagram showing a vibration mode when an angular velocity around the Y axis acts on the vibrator body. It is a block diagram which shows the relationship between the said vibrator main body and the controller connected to this. It is a schematic plan view showing the back side of the vibrator body. It is a principal part top view which shows typically the structure of the 1st vibration adjustment part provided in the said vibrator main body. It is a figure explaining the example of formation of the recessed part which comprises the said 1st vibration adjustment part. It is a figure which shows an example of the relationship between the formation position of the recessed part in FIG. 11A, and the magnitude | size of an unnecessary vibration. It is a figure explaining the example of formation of the recessed part which comprises the said 1st vibration adjustment part. It is a figure which shows an example of the relationship between the formation position of the recessed part in FIG. 12A, and the magnitude | size of an unnecessary vibration. It is a figure explaining the example of formation of the recessed part which comprises the said 1st vibration adjustment part. It is a figure which shows an example of the relationship between the formation position of the recessed part in FIG. 13A, and the magnitude | size of an unnecessary vibration. It is a figure explaining the example of formation of the recessed part which comprises the said 1st vibration adjustment part. It is a figure which shows an example of the relationship between the formation position of the recessed part in FIG. 14A, and the magnitude | size of an unnecessary vibration. It is a principal part top view which shows typically an example of a structure of the 2nd vibration adjustment part provided in the said vibrator main body. It is a principal part top view which shows typically an example of a structure of the 2nd vibration adjustment part provided in the said vibrator main body. It is a principal part top view which shows typically an example of a structure of the 2nd vibration adjustment part provided in the said vibrator main body. It is a principal part top view which shows typically an example of a structure of the 2nd vibration adjustment part provided in the said vibrator main body. It is a schematic plan view which shows one structural example of the sensor element in the gyro sensor which concerns on other embodiment of this technique. FIG. 13 is a schematic bottom view of the sensor element shown in FIG. 12.

  Hereinafter, embodiments according to the present technology will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a perspective view showing a gyro sensor 1 according to an embodiment of the present technology. In the figure, the X, Y, and Z axes indicate three axial directions orthogonal to each other, the X axis direction is the longitudinal direction of the gyro sensor 1, the Y axis direction is the lateral direction, and the Z axis direction is the thickness direction. These correspond to each other (the same applies to the following drawings).

[Gyro sensor]
The gyro sensor 1 of this embodiment includes a sensor element 100 and a controller 200. The gyro sensor 1 is configured as a single package part formed in a substantially rectangular parallelepiped shape as a whole, and has a COC (Chip On Chip) structure in which the sensor element 100 is mounted on the controller 200. The gyro sensor 1 is configured, for example, with dimensions of about 2 mm in length and width and about 0.7 mm in thickness.

Note that the gyro sensor 1 is not limited to the above configuration, and the gyro sensor 1 includes a separate control board that supports the sensor element 100 and the controller 200 in common, and the sensor element 100 and the controller 200 are electrically connected via the control board. It may be configured.
Alternatively, a configuration may be adopted in which a package base material that supports the sensor element 100 and the controller 200 in common is provided separately, and the sensor element 100 and the controller 200 are electrically connected via the package base material.

  The sensor element 100 is configured as a gyro sensor element capable of outputting a signal related to angular velocity. As will be described later, the sensor element 100 has a MEMS (Micro Electro Mechanical System) structure formed by finely processing an SOI (Silicon On Insulator) substrate into a predetermined shape.

  The controller 200 is typically composed of circuit elements such as an IC (Integrated Circuit) chip. The controller 200 has a function of driving the sensor element 100 and calculating an angular velocity signal from the output of the sensor element 100. The upper surface 210 of the controller 200 is provided with a plurality of internal connection terminals that are electrically connected to the sensor element 100, and the lower surface 220 of the controller 200 is electrically connected to a control board (wiring board) (not shown). An external connection terminal is provided.

  The gyro sensor 1 further includes a covering portion 300 that covers the sensor element 100. The covering unit 300 is attached to the upper surface 210 of the controller 200 and configured to shield the sensor element 100 from the outside.

  The covering portion 300 may be made of a conductive material such as metal, or may be made of an electrically insulating material such as a synthetic resin material. The covering unit 300 functions as a cover that prevents foreign matter from entering the gyro sensor 1. Further, when the covering portion 300 is made of a conductive material, the covering portion 300 functions as an electromagnetic shield of the sensor element 100 by being electrically connected to the ground terminal of the controller 200, for example.

  The gyro sensor 1 is mounted on a control board of an electronic device (not shown) via an external connection terminal provided on the lower surface 220 of the controller 200. Examples of the electronic device include a wearable device such as a video camera, a car navigation system, a game machine, and a head mounted display.

[Basic configuration of sensor element]
Next, details of the sensor element 100 will be described. FIG. 2 is a schematic perspective view showing a configuration example of the sensor element 100 and shows the back surface (first main surface) side of the element facing the controller 200.

  The sensor element 100 is made of a material containing single crystal silicon (Si). For example, the sensor element 100 is formed by performing fine processing on an SOI substrate obtained by bonding two silicon substrates, and an active layer W1, a support layer W2, and a bonding layer (BOX (Buried-Oxide) layer) W3. And have. The active layer W1 and the support layer W2 are made of a silicon substrate, and the bonding layer W3 is made of a silicon oxide film.

  The sensor element 100 includes a vibrator main body 101 and a frame body 102. The vibrator main body 101 and the frame body 102 are formed by finely processing the active layer W1 into a predetermined shape. The support layer W2 and the bonding layer W3 are formed in a frame shape around the active layer W1. The thicknesses of the active layer W1, the support layer W2, and the bonding layer W3 are, for example, about 40 μm, about 300 μm, and about 1 μm, respectively.

[Transducer body]
FIG. 3 is a plan view schematically showing the configuration of the vibrator body 101. The vibrator main body 101 includes an annular frame 10 and a plurality of pendulum portions 21a, 21b, 21c, and 21d.

(flame)
The frame 10 has a horizontal direction in the X-axis (second axis) direction, a vertical direction in the Y-axis (third axis) direction, and a thickness direction in the Z-axis (first axis) direction. The frame 10 has a main surface 10s1 (first main surface) perpendicular to the Z-axis. Each side of the frame 10 functions as a vibrating beam and includes a set of first beams 11a and 11b and a set of second beams 12a and 12b.

  The pair of first beams 11a and 11b is composed of a pair of opposite sides extending in parallel to the X-axis direction and facing each other in the Y-axis direction in FIG. The pair of second beams 12a and 12b is composed of another set of opposite sides that extend in the Y-axis direction and face each other in the X-axis direction. Each beam 11a, 11b, 12a, 12b has the same length, width, and thickness, and the cross section perpendicular to the longitudinal direction of each beam is formed in a substantially rectangular shape.

  The size of the frame 10 is not particularly limited. For example, the length of one side of the frame 10 is 1000 to 4000 μm, the thickness of the frame 10 is 10 to 200 μm, and the width of the beams 11a, 11b, 12a, and 12b is 50 to 200 μm. .

  At portions corresponding to the four corners of the frame 10, a plurality (four in this example) of connecting portions 13a and 13b connecting the set of the first beams 11a and 11b and the set of the second beams 12a and 12b are provided. , 13c, 13d are formed. Both ends of the set of the first beams 11a and 11b and the set of the second beams 12a and 12b are supported by the connecting portions 13a to 13d. That is, each beam 11a, 11b, 12a, 12b functions as a vibrating beam whose both ends are supported by the connecting portions 13a to 13d.

(Pendulum part)
The vibrator main body 101 has a plurality of (four in this example) pendulum portions 21a, 21b, 21c, and 21d having a cantilever structure.

  The pendulum portions 21a and 21c (a pair of first pendulum portions) are formed in a pair of connection portions 13a and 13c that are diagonally connected to each other, and are in the diagonal direction (in a plane parallel to the main surface 10s1). (The fourth axial direction intersecting with the X-axis and Y-axis directions) extends inside the frame 10. One end of each of the pendulum portions 21 a and 21 c is supported by the connection portions 13 a and 13 c and protrudes toward the center of the frame 10. The other end of each of the pendulum portions 21 a and 21 c faces each other in the vicinity of the center of the frame 10.

  The pendulum portions 21b and 21d (a pair of second pendulum portions) are respectively formed on the other pair of connection portions 13b and 13d that are in a diagonal relationship with each other, and are in the diagonal direction (parallel to the main surface 10s1). It extends inside the frame 10 along the X axis, the Y axis, and the fifth axis direction intersecting the fourth axis direction) in the plane. One end of each of the pendulum parts 21 b and 21 d is supported by the connection parts 13 b and 13 d and protrudes toward the center of the frame 10. The other end of each of the pendulum parts 21 b and 21 d faces each other in the vicinity of the center of the frame 10.

  Each of the pendulum portions 21 a to 21 d typically has the same shape and size, and is formed simultaneously with the outer shape processing of the frame 10. The shape and size of the pendulum parts 21a to 21d are not particularly limited, and all of them may not be formed in the same shape or the like.

[Frame]
As shown in FIG. 2, the frame body 102 includes an annular base portion 81 disposed around the transducer main body 101, and a plurality of connecting portions 82 disposed between the transducer main body 101 and the base portion 81. Have

(Base part)
The base portion 81 is configured by a rectangular frame that surrounds the outside of the vibrator body 101. The base portion 81 has a rectangular annular main surface 81s formed on the same plane as the main surface 10s1 of the frame 10, and is electrically connected to the controller 200 (see FIG. 1) on the main surface 81s. A plurality of terminal portions (electrode pads) 810 that are connected to each other are provided. A surface (second main surface) opposite to the main surface 81s is bonded to the support layer W2 via the bonding layer W3. The support layer W <b> 2 is configured by a frame similar to the base portion 81 and partially supports the base portion 81.

  As will be described later, the controller 200 includes a control circuit that drives the sensor element 100 and processes the output of the sensor element 100 to detect an angular velocity around each axis. Each terminal portion 810 is electrically and mechanically connected to the controller 200 (or on a control board on which the controller 200 is mounted) via a bump (not shown).

(Connecting part)
The connecting portion 82 includes a plurality of connecting portions 82 a, 82 b, 82 c, and 82 d that support the vibrator main body 101 with respect to the base portion 81 so as to vibrate. The connecting portions 82 a to 82 d extend from the connecting portions 13 a to 13 d of the frame 10 toward the base portion 81. Each of the coupling portions 82a to 82d has a first end portion 821 connected to the vibrator body 101 and a second end portion 822 connected to the base portion 81, and receives the vibration of the frame 10, It is configured to be deformable mainly in the XY plane. That is, the connecting portions 82a to 82d function as a suspension that supports the vibrator main body 101 so as to vibrate.

  The connecting portions 82a to 82d each have a main surface 82s parallel to the main surface 10s1 of the frame 10 and the main surface 81s of the base portion 81. Typically, the main surface 82s includes the main surfaces 10s1 and 81s. Consists of the same plane. That is, the connecting portions 82 a to 82 d of the present embodiment are configured by the same silicon substrate as the silicon substrate that constitutes the vibrator body 101.

  The connecting portions 82a to 82d are typically formed in a symmetric shape with respect to the X axis and the Y axis. As a result, the deformation direction of the frame 10 in the XY plane becomes isotropic, and it is possible to detect the angular velocity with high accuracy around each axis without causing the frame 10 to be twisted or the like.

  The shapes of the connecting portions 82a to 82d may be linear or non-linear. In the present embodiment, as shown in FIG. 2, each of the connecting portions 82 a to 82 d includes a turning portion 820 whose extending direction is reversed by approximately 180 ° between the vibrator main body 101 and the base portion 81. In this way, by increasing the extension length of each of the connecting portions 82a to 82d, the vibrator main body 101 can be supported without inhibiting the vibration of the vibrator main body 101. Furthermore, the effect of not transmitting external vibration (impact) to the vibrator main body 101 is also obtained.

[Piezoelectric drive unit]
The sensor element 100 includes a plurality of piezoelectric drive units that vibrate the frame 10 in an XY plane parallel to the main surface 10s1.

  As shown in FIG. 3, the plurality of piezoelectric driving units include a pair of first piezoelectric driving units 31 provided on the main surface 10s of the set of the first beams 11a and 11b, and second beams 12a and 12b. And a pair of second piezoelectric drive units 32 provided on the main surface 10s1 of the set. The first and second piezoelectric driving units 31 and 32 are mechanically deformed according to the input voltage, and vibrate the beams 11a, 11b, 12a, and 12b with the driving force of the deformation. The direction of deformation is controlled by the polarity of the input voltage.

  The first and second piezoelectric drive units 31 and 32 are the upper surfaces (main surfaces 10s1) of the beams 11a, 11b, 12a, and 12b, and are linearly formed in parallel to their axes. In FIG. 3, in order to facilitate understanding, the first and second piezoelectric driving units 31 and 32 are indicated by different hatchings. The first piezoelectric drive unit 31 is arranged on the outer edge side of the set of the first beams 11a and 11b, and the second piezoelectric drive unit 32 is arranged on the outer edge side of the set of the second beams 12a and 12b. Yes.

  The first and second piezoelectric drive units 31 and 32 have the same configuration. Each piezoelectric drive unit has a laminated structure of a lower electrode layer, a piezoelectric film, and an upper electrode layer. The upper electrode layer corresponds to the first driving electrode (D1) in the first piezoelectric driving unit 31, and corresponds to the second driving electrode (D2) in the second piezoelectric driving unit 32. Equivalent to. On the other hand, the lower electrode layer corresponds to the second drive electrode (D2) in the first piezoelectric drive unit 31, and the first drive electrode (D1) in the second piezoelectric drive unit 32. ). An insulating film such as a silicon oxide film is formed on the surface (main surface 10s1) of the beam on which each piezoelectric driving layer is formed.

  The piezoelectric film is typically composed of lead zirconate titanate (PZT). The piezoelectric film is polarized and oriented so as to expand and contract in accordance with the potential difference between the lower electrode layer and the upper electrode layer. At this time, AC voltages having opposite phases are applied to the upper electrode layer and the lower electrode layer. Thereby, compared with the case where a lower electrode layer is used as a common electrode, the piezoelectric film can be expanded and contracted with about twice the amplitude.

  In the present embodiment, the first drive signal (G +) is input to the upper electrode layer (first drive electrode D1) of each of the first piezoelectric drive units 31, and these lower electrode layers (second The driving electrode D2) is configured to receive a second driving signal (G−) that is differential (opposite phase) from the driving signal (G +). On the other hand, the second drive signal (G−) is inputted to the upper electrode layer (second drive electrode D2) of each of the second piezoelectric drive units 32, and these lower electrode layers (first drive electrode). The first drive signal (G +) is input to each of the electrodes D1).

(Drive principle)
The first piezoelectric drive unit 31 and the second piezoelectric drive unit 32 are applied with voltages of opposite phases so that when one is extended, the other is contracted. As a result, the pair of second beams 12a and 12b is subjected to bending deformation in the X-axis direction while both ends are supported by the connection portions 13a to 13d, and both are close to each other in the XY plane. It vibrates alternately in the direction. Similarly, the pair of the first beams 11a and 11b is also subjected to bending deformation in the Y-axis direction with both ends supported by the connecting portions 13a to 13d, and the direction in which both are separated from each other and the direction in which both are close in the XY plane. And vibrate alternately.

  Therefore, when the set of the first beams 11a and 11b vibrates in a direction close to each other, the set of the second beams 12a and 12b vibrates in a direction away from each other, and the first beams 11a and 11b When the set vibrates in a direction away from each other, the set of the second beams 12a and 12b vibrates in a direction close to each other. At this time, the central part of each beam 11a, 11b, 12a, 12b forms a vibration antinode, and both ends (connecting parts 13a to 13d) form vibration nodes (nodes). Such a vibration mode is hereinafter referred to as a basic vibration of the frame 10.

  The beams 11a, 11b, 12a, 12b are driven at their resonance frequencies. The resonance frequency of each beam 11a, 11b, 12a, 12b is determined by their shape, length, and the like. Typically, the resonance frequencies of the beams 11a, 11b, 12a, and 12b are set in the range of 1 to 100 kHz.

  FIG. 4 is a schematic diagram showing a time change of the fundamental vibration of the frame 10. In FIG. 3, “drive signal 1” indicates the time change of the input voltage applied to the upper electrode (first drive electrode D <b> 1) of the first piezoelectric drive unit 31, and “drive signal 2” is the second The time change of the input voltage applied to the upper electrode (second drive electrode D2) of the piezoelectric drive unit 32 is shown.

  As shown in FIG. 4, the drive signal 1 and the drive signal 2 have alternating waveforms that change in opposite phases. Thereby, the frame 10 changes in the order of (a), (b), (c), (d), (a),..., And the set of the first beams 11a, 11b and the second beams 12a, The frame 10 vibrates in a vibration mode in which the other set is separated when one set is close to the set of 12b and the other set is close when the one set is separated.

  Along with the basic vibration of the frame 10 described above, the pendulum parts 21a to 21d also vibrate in the XY plane around the connection parts 13a to 13d in synchronization with the vibration of the frame 10 (in the direction of the arrow shown in FIG. 3). And FIG. 4). The vibrations of the pendulum parts 21a to 21d are excited by the vibrations of the beams 11a, 11b, 12a, and 12b. In this case, the pendulum parts 21a and 21c and the pendulum parts 21b and 21d vibrate (oscillate) in mutually opposite phases at the support points of the arm portions in the XY plane, that is, the left and right swing directions from the connection parts 13a to 13d. .

  As described above, the beams 11a, 11b, 12a, and 12b of the frame 10 are applied to the first and second drive electrodes D1 and D2 as shown in FIG. It vibrates in the vibration mode shown in. When an angular velocity around the Z-axis acts on the frame 10 that continues such basic vibration, the Coriolis force F0 resulting from the angular velocity acts on each point of the frame 10, so that the frame 10 is schematically illustrated in FIG. As shown in FIG. 4, the deformation occurs so as to be distorted in the XY plane. Therefore, by detecting the amount of deformation of the frame 10 in the XY plane, it is possible to detect the magnitude and direction of the angular velocity around the Z axis that has acted on the frame 10.

[First piezoelectric detector]
As shown in FIG. 3, the sensor element 100 further includes a plurality of first piezoelectric detectors 51a, 51b, 51c, and 51d (first detectors). The first piezoelectric detectors 51a to 51d detect angular velocities around the Z axis (first axis) perpendicular to the main surface 10s1 based on the deformation amount of the main surface 10s1 of the frame 10. The first piezoelectric detectors 51a to 51d include four piezoelectric detectors provided on the main surface 10s1 of the four connecting portions 13a to 13d, respectively.

  The first piezoelectric detectors 51a and 51c are respectively formed around one set of connecting portions 13a and 13c having a diagonal relationship. Of these, one piezoelectric detector 51a extends in two directions from the connecting portion 13a along the beams 11a and 12a, and the other piezoelectric detector 51c extends from the connecting portion 13c along the beams 11b and 12b. Extending in the direction.

  Similarly, the first piezoelectric detectors 51b and 51d are respectively formed around the other set of connecting portions 13b and 13d in a diagonal relationship. Of these, one piezoelectric detector 51b extends in two directions from the connecting portion 13b along the beams 11b and 12a, and the other piezoelectric detector 51d extends from the connecting portion 13d along the beams 11a and 12b. Extending in the direction.

  The first piezoelectric detectors 51a to 51d have the same configuration as the first and second piezoelectric drive units 31 and 32. That is, the first piezoelectric detectors 51a to 51d are composed of a laminate of a lower electrode layer, a piezoelectric film, and an upper electrode layer, and mechanical deformation of each beam 11a, 11b, 12a, 12b is converted into an electrical signal. Has a function to convert. In the first piezoelectric detectors 51a to 51d, each lower electrode layer is connected to a reference potential (Vref) such as a ground potential, and each upper electrode layer outputs a detection signal (z1, z2, z3, z4). The first detection electrode (S1) is configured.

  In the present embodiment, each of the first piezoelectric detectors 51a to 51d provided in the frame 10 includes a plurality of detection electrode units (first detection electrodes) that output a first detection signal including angular velocity information about the Z axis. ).

  In the vibrator main body 101 shown in FIG. 3, when the angular velocity acts around the Z axis, the size of the inner angle of the frame 10 periodically varies as shown in FIGS. At this time, fluctuations in internal angles are opposite to each other in the pair of one connection portions 13a and 13c and the other connection portion 13b and 13d in a diagonal relationship. Therefore, the output of the piezoelectric detector 51a on the connecting portion 13a and the output of the piezoelectric detector 51c on the connecting portion 13c are the same in principle, and the output of the piezoelectric detecting portion 51b on the connecting portion 13b and the output of the piezoelectric detecting portion 51c on the connecting portion 13d. The output of the piezoelectric detector 51d is the same in principle. Therefore, by calculating the difference between the sum of the outputs of the two piezoelectric detectors 51a and 51c and the sum of the outputs of the two piezoelectric detectors 51b and 51d, the magnitude of the angular velocity around the Z axis acting on the frame 10 and The direction can be detected.

[Second piezoelectric detector]
On the other hand, as a detector that detects an angular velocity around the X axis and an angular velocity around the Y axis, the sensor element 100 includes a plurality of second piezoelectric detectors 71a, 71b, 71c, 71d (second Detection section). The second piezoelectric detectors 71a to 71d calculate the angular velocities in the two-axis directions (eg, the X-axis direction and the Y-axis direction) perpendicular to the Z-axis based on the deformation amounts in the Z-axis direction of the plurality of pendulum portions 21a to 21d. To detect. The second piezoelectric detectors 71a to 71d include four piezoelectric detectors provided on the four pendulum portions 21a to 21d, respectively.

  The second piezoelectric detectors 71a to 71d are the surfaces of the pendulum portions 21a to 21d (the same main surface as the main surface 10s1), and are arranged on these axes. The second piezoelectric detectors 71a to 71d have the same configuration as that of the first piezoelectric detectors 51a to 51d, and are composed of a laminate of a lower electrode layer, a piezoelectric film, and an upper electrode layer. It has a function of converting mechanical deformations of the portions 21a to 21d into electric signals. In the second piezoelectric detectors 71a to 71d, each lower electrode layer is connected to a reference potential (Vref) such as a ground potential, and each upper electrode layer outputs a detection signal (xy1, xy2, xy3, xy4). The second detection electrode (S2) is configured.

  In the present embodiment, each of the second piezoelectric detectors 71a to 71d provided in the pendulum portions 21a to 21d includes a second detection signal and a third detection signal including angular velocity information about the X axis and angular velocity information about the Y axis. It functions as a plurality of detection electrode portions (second detection electrode, third detection electrode) that output detection signals.

  For example, when an angular velocity around the X-axis acts on the frame 10 that vibrates with basic vibration, the Coriolis force F1 in the direction orthogonal to the vibration direction at that moment is applied to each pendulum portion 21a to 21d as schematically shown in FIG. Each occurs. As a result, the pair of pendulum portions 21a and 21d adjacent in the X-axis direction is deformed in the positive direction of the Z-axis by the Coriolis force F1, and the deformation amounts thereof are detected by the piezoelectric detectors 71a and 71d, respectively. . The other pair of pendulum parts 21b and 21c adjacent in the X-axis direction is deformed in the negative direction of the Z-axis by the Coriolis force F1, and the deformation amounts thereof are detected by the piezoelectric detectors 71b and 71c, respectively.

  Similarly, when an angular velocity around the Y-axis acts on the frame 10 that vibrates with basic vibration, as shown schematically in FIG. 7, the Coriolis force F2 in the direction orthogonal to the vibration direction at that moment is applied to each pendulum part 21a to 21d. Each occurs. As a result, the pair of pendulum portions 21a and 21b adjacent in the Y-axis direction is deformed in the positive direction of the Z-axis by the Coriolis force F2, and the deformation amounts thereof are detected by the piezoelectric detectors 71a and 71b, respectively. . Further, the other pair of pendulum portions 21c and 21d adjacent in the Y-axis direction is deformed in the negative direction of the Z-axis by the Coriolis force F2, and the deformation amounts thereof are detected by the piezoelectric detectors 71c and 71d, respectively.

  Even when an angular velocity is generated around an axis in a direction that obliquely intersects the X axis and the Y axis, the angular velocity is detected based on the same principle as described above. That is, each pendulum part 21a-21d deform | transforms with the Coriolis force according to the X direction component and Y direction component of the said angular velocity, and those deformation amounts are each detected by piezoelectric detection part 71a-71d. The controller 200 extracts the angular velocity around the X axis and the angular velocity around the Y axis based on the outputs of the piezoelectric detectors 71a to 71d. This makes it possible to detect an angular velocity around an arbitrary axis parallel to the XY plane.

[Reference electrode]
The sensor element 100 has a reference electrode 61 as shown in FIG. The reference electrode 61 is disposed adjacent to the second piezoelectric drive unit 32 on the beam 12a and the beam 12b. The reference electrode 61 has the same configuration as the first and second piezoelectric detectors 51a to 51d and 71a to 71d, and is composed of a laminate of a lower electrode layer, a piezoelectric film, and an upper electrode layer. , Has a function of converting mechanical deformation of the beams 12a and 12b into an electric signal. The lower electrode layer is connected to a reference potential such as a ground potential, and the upper electrode layer functions as a detection electrode that outputs a reference signal (FB signal). The reference signal is used as a vibration monitor signal indicating the vibration state of the vibrator 100.

  Instead of forming the reference electrode 61, a sum signal of the outputs of the first piezoelectric detectors 51a to 51d can be generated and used as the reference signal.

[controller]
Next, details of the controller 200 will be described. FIG. 8 is a block diagram showing the configuration of the controller 200.

  The controller 200 includes a self-excited oscillation circuit 201 and a detection circuit (an arithmetic circuit 203, a detection circuit 204, and a smoothing circuit 205). The self-excited oscillation circuit 201 generates a drive signal that vibrates the vibrator main body 101 (the frame 10, the pendulum portions 21a to 21d) in the XY plane. The detection circuit generates and outputs angular velocities around the X, Y, and Z axes based on the detection signals (z1, z2, z3, z4, xy1, xy2, xy3, xy4) output from the vibrator main body 101.

The controller 200 has a G + terminal, a G− terminal, a GFB terminal, a Gxy1 terminal, a Gxy2 terminal, a Gxy3 terminal, a Gxy4 terminal, a Gz1 terminal, a Gz2 terminal, a Gz3 terminal, a Gz4 terminal, and a Vref terminal.
Note that the Gz1 terminal and the Gz3 terminal may be configured by a common terminal, and the Gz2 terminal and the Gz4 terminal may be configured by a common terminal. In this case, the wirings connected to the Gz1 terminal and the Gz3 terminal are integrated with each other on the way, and the wirings connected to the Gz2 terminal and the Gz4 terminal are integrated with each other on the way.

  In the present embodiment, the G + terminal is electrically connected to the upper electrode layer of the first piezoelectric drive unit 31 and the lower electrode layer of the second piezoelectric drive unit 32, respectively. The G-terminal is electrically connected to the lower electrode layer of the first piezoelectric drive unit 31 and the upper electrode layer (drive electrode D2) of the second piezoelectric drive unit 32, respectively. The GFB terminal is electrically connected to the upper electrode layer of the reference electrode 61, respectively.

  The G + terminal is connected to the output terminal of the self-excited oscillation circuit 201. The G-terminal is connected to the output terminal of the self-excited oscillation circuit 201 via the inverting amplifier 202. The self-excited oscillation circuit 201 generates a drive signal (AC signal) for driving the first and second piezoelectric drive units 31 and 32. The inverting amplifier 202 generates a drive signal (second drive signal G−) having the same magnitude as the drive signal (first drive signal G +) generated by the self-excited oscillation circuit 201 and having a phase inverted by 180 °. To do. Thereby, the 1st and 2nd piezoelectric drive parts 31 and 32 are expanded-contracted in a mutually opposite phase. For ease of understanding, the connection between the lower electrode layers of the piezoelectric drive units 31 and 32 and the controller 200 is omitted in FIG.

  The Gxy1 terminal, the Gxy2 terminal, the Gxy3 terminal, and the Gxy4 terminal are electrically connected to the upper electrode layer (second detection electrode S2) of the second piezoelectric detection units 71a, 71b, 71c, and 71d, respectively. The Gz1, Gz2, Gz3, and Gz4 terminals are electrically connected to the upper electrode layers (first detection electrodes S1) of the first piezoelectric detectors 51a, 51b, 51c, and 51d, respectively. The Vref terminal is electrically connected to the lower electrode layer of the reference electrode 61 and the lower electrode layers of the first and second piezoelectric detectors 51a to 51d and 71a to 71d, respectively.

  The GFB terminal, the Gxy1 terminal, the Gxy2 terminal, the Gxy3 terminal, the Gxy4 terminal, the Gz1 terminal, the Gz2 terminal, the Gz3 terminal, and the Gz4 terminal are each connected to the input terminal of the arithmetic circuit 203. The arithmetic circuit 203 generates a first difference circuit for generating an angular velocity signal around the X axis, a second difference circuit for generating an angular velocity signal around the Y axis, and an angular velocity signal around the Z axis. A third difference circuit for the purpose.

  Assume that the outputs of the first piezoelectric detectors 51a to 51d are z1 to z4, respectively, and the outputs of the second piezoelectric detectors 71a to 71d are xy1 to xy4, respectively. At this time, the first difference circuit calculates (xy1 + xy2) − (xy3 + xy4) and outputs the calculated value to the detection circuit 204x. The second difference circuit calculates (xy1 + xy4) − (xy2 + xy3), and outputs the calculated value to the detection circuit 204y. The third difference circuit calculates (z1 + z3) − (z2 + z4) and outputs the calculated value to the detection circuit 204z.

  The detection circuits 204x, 204y, and 204z perform full-wave rectification on the differential signal in synchronization with the output of the drive signal from the self-excited oscillation circuit 201 or the reference signal (FB), and convert it into a direct current. Smoothing circuits 205x, 205y, and 205z smooth the outputs of the detection circuits 204x, 204y, and 204z. The DC voltage signal ωx output from the smoothing circuit 205x includes information regarding the magnitude and direction of the angular velocity around the X axis, and the DC voltage signal ωy output from the smoothing circuit 205y includes the magnitude of the angular velocity around the Y axis and Contains information about directions. Similarly, the DC voltage signal ωz output from the smoothing circuit 205z includes information on the magnitude and direction of the angular velocity around the Z axis. That is, the magnitude of the DC voltage signals ωx, ωy, and ωz with respect to the reference potential Vref corresponds to information related to the magnitude of the angular velocity, and the polarity of the DC voltage signal corresponds to information related to the direction of the angular velocity.

[Vibration adjuster]
As described above, the sensor element 100 is configured such that each of the pendulum portions 21a to 21d vibrates in the XY plane in synchronization with the basic vibration of the frame 10 driven by the piezoelectric drive portions 31 and 32 (FIG. 4). reference). However, the desired in-plane symmetry may not be obtained depending on the machining accuracy of each part of the sensor element 100 and the patterning accuracy of various functional films such as a piezoelectric film. In this case, there is a possibility that not only the lateral resonance vibration (drive mode) in the plane parallel to the XY plane but also the longitudinal resonance vibration (detection mode) outside the plane intersecting the XY plane occurs in the pendulum portions 21a to 21d. As a result, a significant angular velocity signal is generated from the output of the second piezoelectric detectors 71a to 71d due to the out-of-plane vibration of the pendulum portions 21a to 21d, even though no angular velocity is generated, and the detection accuracy decreases. To do.

  Therefore, the sensor element 100 of the present embodiment includes a vibration adjustment unit VA for suppressing out-of-plane vibration (hereinafter also referred to as unnecessary vibration) of each pendulum unit in the drive mode. Details of the vibration adjustment unit VA will be described below.

  FIG. 9 is a schematic plan view of the second main surface 10 s 2 of the vibrator main body 101. The second main surface 10s2 is a main surface opposite to the first main surface 10s1 on which the piezoelectric driving unit 31 and the piezoelectric detection units 51a to 51d and 71a to 71d illustrated in FIG. 3 are formed. The vibration adjustment unit VA includes a first vibration adjustment unit VA1 and a second vibration adjustment unit VA2 provided in a predetermined region of the second main surface 10s2 of the vibrator body 101.

(First vibration adjustment unit)
The first vibration adjustment unit VA1 is provided on the first beams 11a and 11b and the second beams 12a and 12b (hereinafter also referred to as beams 11a to 12b) constituting the frame 10. In the present embodiment, the first vibration adjustment portion VA1 is the second main surface 10s2 of the frame 10, and is provided on the inner peripheral edge portion and the outer peripheral edge portion of the frame 10, respectively. The first vibration adjustment unit VA1 is provided in all the beams 11a to 12b, but is not limited thereto, and may be provided in at least one beam.

  FIG. 10 is a plan view of main parts of the beams 11a to 12b showing a configuration example of the first vibration adjustment unit VA1.

  As shown in FIG. 10, the first vibration adjustment unit VA <b> 1 includes a plurality of recesses 91. The plurality of recesses 91 are arranged at intervals on two linear reference lines 11v1 and 11v2 along the inner and outer peripheral edges of the beams 11a to 12b. The two reference lines 11v1 and 11v2 are virtual lines that are respectively set at symmetrical positions with respect to the center line 11c on the main surface 10s2 of the beams 11a to 12b. The center line 11c is a virtual straight line that passes through the center in the width direction of the main surface 10s2 of the beams 11a to 12b and is parallel to the longitudinal direction of the beams 11a to 12b.

For the beams 11a and 11b, the first vibration adjusting unit VA1 is for adjusting the vibration characteristics along the Y-axis direction of the beams 11a and 11b. An appropriate number of recesses 91 are provided at appropriate positions on the reference lines 11v1 and 11v2 of the beams 11a and 11b, the rigidity of the beams 11a and 11b is reduced, and the spring constant of the beams 11a and 11b during vibration is reduced. Thus, the beams 11a and 11b are likely to vibrate along the Y-axis direction.
Similarly, with respect to the beams 12a and 12b, the vibration characteristics along the X-axis direction are adjusted by the first vibration adjustment unit VA1.

  As described above, the first vibration adjustment unit VA1 stabilizes the in-plane vibration in the XY plane of each beam 11a to 12b, and drives the frame 10 with a predetermined basic vibration. Thereby, the stable in-plane vibration of each pendulum part 21a-21d is accelerated | stimulated, and the unnecessary vibration of each pendulum part 21a-21d is suppressed.

  The number, part, and the like of the concave portions 91 provided on the reference lines 11v1 and 11v2 vary depending on the type of unnecessary vibration. Typically, the concave portions 91 are provided symmetrically outward from the central portions of the beams 11a to 12b. . For example, FIG. 11A shows an example of forming the recess 91 provided on the reference line 11v2 along the outer peripheral edge of the beam 12a. As shown in the figure, the recess 91 is provided on the object from the processing position 1 to the processing position 8 from the beam center to the outside. The magnitude of the unnecessary vibration (Null Y) when the frame 10 vibrates in the Y-axis direction differs depending on the machining position of the recess 91. For example, as shown in FIG. 11B, the magnitude of the unwanted vibration depends on the machining position. It changes (In FIG. 11B, the processing position 0 means a state without a recess. The same applies to FIGS. 12B, 13B, and 14B).

  On the other hand, FIGS. 12A and 12B show an example of the relationship between the formation position of the recess 91 on the reference line 11v1 along the inner peripheral edge of the beam 12a and the magnitude of unnecessary vibration. As shown in the figure, as the formation range of the concave portion 91 becomes wider, the change in the magnitude of unnecessary vibration (Null Y) during vibration in the Y-axis direction tends to be opposite to the example of FIG. 11B. I understand. This relationship shows the same tendency between the beam 12a on the left side and the beam 12b on the right side in the drawing even when the recess is formed on the same reference line 11v1 (or 11v2).

  The concave portions 91 formed in the beams 11a and 11b also have the same operation as described above. An example of the relationship between the formation position of the concave portion 91 on the reference line 11v2 along the outer peripheral edge of the beam 11a and the magnitude of unnecessary vibration is shown in FIGS. 13A and 13B on the reference line 11v1 along the inner peripheral edge of the beam 11a. An example of the relationship between the formation position of the concave portion 91 and the magnitude of unnecessary vibration is shown in FIGS. 14A and 14B, respectively.

  As described above, by processing a part of the beams 11a to 12b according to unnecessary vibration, the spring constant of the entire vibrator can be adjusted and the vibration mode can be adjusted.

  Each recess 91 constituting the first vibration adjustment unit VA1 is typically formed by laser light irradiation (laser processing method) to the main surface 10s2. The shape, size, depth, and the like of the recess 91 are not particularly limited, and are appropriately set depending on the size, thickness, and the like of the frame 10. Typically, the opening shape of the recess is circular, the size (opening diameter) is 1/50 to 1/3 of the width of the beams 11a to 12b, and the depth is 1/150 of the thickness of the beams 11a to 12b. It is made into the range of -1/3.

  The interval between the recesses 91 (the distance between the centers of the adjacent recesses 91) is not particularly limited, and may be an equal pitch or an unequal pitch. In order to prevent local stress concentration of the beam, it is preferable that the recesses 91 do not overlap each other. Typically, the interval between the recesses 91 is equal to or larger than the opening diameter of the recesses 91.

(Second vibration adjustment unit)
The second vibration adjustment unit VA2 is for adjusting the vibration characteristics of the pendulum units 21a to 21d, and is provided on the main surface of the pendulum units 21a to 21d, and typically the pendulum units 21a to 21d. Provided on the arm part. The main surfaces of the pendulum portions 21a to 21d are configured in the same plane as the main surface 10s2 of the frame 10, and are similarly referred to as the main surface 10s2.

  15A to 15D are schematic plan views of the main part showing a typical form of the second vibration adjustment unit VA2.

  As shown in FIGS. 15A to 15D, the second vibration adjustment unit VA <b> 2 includes a plurality of recesses 92. The plurality of recesses 92 are spaced on the center line 20c of the main surface 10s2 of the pendulum part 21a or on two linear reference lines 20v1 and 20v2 of the main surface 10s2 along both side edges of the arm part of the pendulum part 21a. Arranged with a gap. The two reference lines 20v1 and 20v2 are virtual lines that are set at symmetrical positions with respect to the center line 20c. The center line 20c is a virtual straight line that passes through the center in the width direction of the main surface 10s2 of the arm part of the pendulum part 21a and is parallel to the longitudinal direction of the arm part.

  The second vibration adjustment unit VA2 is for adjusting the in-plane vibration and the out-of-plane vibration of the pendulum units 21a to 21d. Typically, the second vibration adjustment unit VA2 is used to adjust the drive mode (lateral resonance frequency), detection mode (longitudinal resonance frequency), detuning degree, and the like of each of the pendulum units 21a to 21d.

  When adjusting the in-plane vibrations of the pendulum portions 21a to 21d, as shown in FIG. 15A, the laser beam is irradiated on two reference lines 20v1 and 20v2 that are symmetrical with respect to the center line 20c of the arm portion, and an appropriate number is applied. A recess 92 having a size is formed. Thereby, since the spring constant and vibration mass at the time of vibration in the XY plane of the pendulum parts 21a to 21d change, the pendulum parts 21a to 21d can be vibrated at a desired drive frequency (lateral resonance frequency).

  The recesses 92 on the reference lines 20v1 and 20v2 are preferably provided at positions and sizes that are symmetrical with respect to the center line 20c. Since the in-plane symmetry is maintained, the in-plane vibration characteristics can be easily adjusted. Moreover, it is preferable that the recessed part 92 on each reference line 20v1, 20v2 is provided in common at the corresponding position of each pendulum part 21a-21d. Thereby, since the in-plane vibration of all the pendulum parts 21a-21d is adjusted more cooperatively, generation | occurrence | production of an unnecessary vibration is suppressed.

  On the other hand, when adjusting the out-of-plane vibration of the pendulum portions 21a to 21d, as shown in FIG. 15B, the laser beam is irradiated onto the center line 20c of the arm portion to form concave portions 92 of an appropriate number and size. To do. Thereby, since the spring constant at the time of vibration in the direction perpendicular | vertical to XY plane of pendulum part 21a-21d changes, pendulum part 21a-21d can be vibrated with the desired detection frequency (longitudinal resonance frequency).

  FIG. 15C is a schematic diagram illustrating an example in which the center line 20c is divided into two center auxiliary lines 20c1 and 20c2. The center auxiliary lines 20c1 and 20c2 are imaginary lines that are symmetrical with respect to the center line 20c and are set close to the center line 20c. By providing the concave portions 92 in the center auxiliary lines 20c1 and 20c2, the longitudinal resonance frequencies of the pendulum portions 21a to 21d can be finely adjusted.

  FIG. 15D shows an example in which a recess 92 is provided on the center line 20c (or the center auxiliary lines 20c1 and 20c2) and the reference lines 20v1 and 20v2 of the pendulum portions 21a to 21d. According to this example, the in-plane resonance frequency and the out-of-plane resonance frequency of the pendulum portions 21a to 21d can be more coordinated.

  Each recessed part 92 which comprises 2nd vibration adjustment part VA2 is comprised by the method and form similarly to the recessed part 91 which comprises 1st vibration adjustment part VA1. The shape, size, depth, and the like of the recess 92 are not particularly limited, and are appropriately set depending on the length, thickness, and the like of the pendulum portions 21 a to 21. The opening shape, size (opening diameter), depth, interval, and the like of the recess 92 can be set similarly to the recess 91.

  In the above description, the example in which the second vibration adjustment portion VA2 is provided on the arm portion of the pendulum portions 21a to 21d has been described. However, instead of or in addition to this, the tip of the pendulum portions 21a to 21d The vibration adjusting unit may also be provided in the weight part. In addition, the number of reference lines and center auxiliary lines in which the recesses 92 are formed is not particularly limited, and may be three or more virtual lines including the center line 20c.

In a multi-axis gyro sensor capable of detecting angular velocities around multiple axes, a single sensor element is provided with multiple transducers corresponding to each detection axis, so the vibration characteristics of one transducer can be adjusted. As a result, the vibration characteristics of the other vibrators are affected, and the vibration characteristics of the vibrators of the respective detection axes cannot be easily adjusted.
However, according to the gyro sensor 1 (sensor element 100) of the present embodiment, the vibration characteristics of the plurality of vibrators (the frame 10, the pendulum portions 21a to 21d) can be coordinately adjusted. The child can be easily adjusted to desired vibration characteristics.

  Further, according to the present embodiment, since the first and second vibration adjustment units VA1 and VA2 are provided on the second main surface 10s2 of the sensor element 100, the piezoelectric drive units 31 and 32 and the piezoelectric detection units 51a to 51d, The vibration characteristics can be adjusted without depending on the positions of 71a to 71d, the reference electrode 61, and the like.

<Second Embodiment>
Subsequently, a second embodiment of the present technology will be described.

FIG. 16 is a schematic plan view of the first principal surface 10s1 side showing the configuration of the sensor element in the gyro sensor of the present embodiment. FIG. 17 is a schematic plan view of the sensor element on the second main surface 10s2 side.
Hereinafter, the configuration different from the first embodiment will be mainly described, and the same configuration as the first embodiment will be denoted by the same reference numeral, and the description thereof will be omitted or simplified.

  The sensor element 150 of this embodiment has an annular frame 110. In the frame 110 shown in FIG. 16, the set of the first beams 11a and 11b and the set of the second beams 12a and 12b are protruding portions that protrude inward of the square S having the respective connecting portions 13a to 13d as vertices. Each has p and is formed into an arcuate shape as a whole.

  The protrusions p of the first beams 11a and 11b are formed in parallel to the X-axis direction, and face each other in the Y-axis direction. The projecting portions p of the second beams 12a and 12b are formed in parallel to the Y-axis direction and face each other in the X-axis direction. On the surface of the frame 110 and the pendulum portions 21a to 21d (first main surface 10s1), the first and second piezoelectric drive portions 31 and 32, the first and second piezoelectric detection portions 51a to 51d, and 71a to 71d. A reference electrode 61 is provided.

  In the frame 110 configured as described above, since the beams 11a, 11b, 12a, and 12b are formed in an arc shape, the length of each beam forming the frame is short even when the occupied area of the frame is reduced. In other words, the resonance frequency of the vibration mode does not change greatly. Therefore, for example, when an angular velocity acts around the Z axis, distortion deformation in the XY plane as shown in FIG. 5 is not hindered, so that the angular velocity detection sensitivity around the Z axis can be maintained.

  On the other hand, the plurality of connecting portions 82 a to 82 d that connect the frame 110 to the base portion 81 have a first end portion 821 connected to the frame 110 and a second end portion 822 connected to the base portion 81. (Only the connecting portion 82a is indicated in FIG. 16).

  The connecting parts 82a to 82d have first inversion parts wa1, wb1, wc1, wd1 and second inversion parts wa2, wb2, wc2, wd2, respectively. The first reversing portions wa1 to wd1 have a turning portion 823 that is connected at one end to the connecting portions 13a to 13d and is folded back approximately 180 ° in the X-axis direction. On the other hand, the second reversing portions wa2 to wd2 have a turning portion 824 that is connected at one end to the other end portions of the first reversing portions wa1 to wd1 and folded back approximately 180 ° in the Y-axis direction. The other ends of the second inversion portions wa <b> 2 to wd <b> 2 are connected to the base portion 81.

  At this time, as shown in FIG. 16, the second reversing portions wa <b> 2 to wd <b> 2 are formed on the second beams 12 a and 12 b so that the turning portion 822 enters the inner side of the square S forming the outer shape of the frame 110. The protrusion p is partially bent toward the outer peripheral side. As described above, by designing at least a part of the connecting portions 82a to 82d according to the outer shape of the frame 110, the extending length of the connecting portions 82a to 82d can be increased without increasing the size of the base portion 81. it can.

  The sensor element 150 configured as described above includes a first vibration adjustment unit VA1, a second vibration adjustment unit VA2, and a third vibration adjustment unit VA3 as the vibration adjustment unit VA.

The first vibration adjustment unit VA1 is for suppressing unnecessary vibrations of the frame 110 and the pendulum units 21a to 21d. Similarly to the first embodiment, the beams 11a, 11b, 12a, It is provided on the second main surface 10s2 of 12b (see FIG. 17).
The second vibration adjustment unit VA2 is for adjusting the in-plane vibration and the out-of-plane vibration of the pendulum portions 21a to 21d. As in the first embodiment, the second main body of the pendulum portions 21a to 21d Provided on the surface 10s2 (see FIG. 17).
The third vibration adjustment unit VA3 is for adjusting unnecessary vibration and lateral resonance frequency or detuning degree of the frame 110, and is provided on the second main surface 10s2 of the plurality of coupling units 82a to 82d. .

  In the present embodiment, as shown in FIG. 17, the third vibration adjustment unit VA3 includes first inversion units wa1 to wd1 and second inversion units wa2 to wd2 (see FIG. 16) among the coupling units 82a to 82d. (Hereinafter also referred to as reversing portions wa1 to wd2) on both side edges in the longitudinal direction. The third vibration adjustment unit VA3 includes a plurality of recesses as in the first embodiment, and by changing the mechanical rigidity (spring constant) of a predetermined region of the coupling portions 82a to 82d by the plurality of recesses, Adjust the vibration characteristics.

  The plurality of recesses are arranged at intervals on two linear reference lines along the inner peripheral edge and the outer peripheral edge of the reversing parts wa1 to wd2. The two reference lines are virtual lines that are respectively set at symmetrical positions with respect to the center line on the main surface 10s2 of the reversing portions wa1 to wd2. The center line 11c is a virtual straight line that passes through the center in the width direction of the main surface 10s2 of the reversing portions wa1 to wd2 and is parallel to the longitudinal direction of the reversing portions wa1 to wd2.

  As described above, the third vibration adjustment unit VA3 adjusts the in-plane vibration in the XY plane of the reversing units wa1 to wd2, thereby suppressing the out-of-plane vibration (unnecessary vibration) of the frame 110. Further, the third vibration adjustment unit VA3 can adjust the in-plane vibration in the XY plane of the reversing units wa1 to wd2, thereby adjusting the lateral resonance frequency or the degree of detuning of the frame 110.

  Here, it is preferable that the third vibration adjustment unit VA3 is formed symmetrically with respect to each of the plurality of coupling units 82a to 82d. For example, the position, the number, the size, the interval, and the like of the concave portions provided in the reversing portions wa1 to wd2 are formed to be the same as the reversing portions of other corresponding connecting portions. As a result, a symmetrical vibration characteristic can be obtained in the plane of the sensor element 150 with the frame 110 as the center, so that the occurrence of unnecessary vibration can be effectively suppressed.

  In the present embodiment, the third vibration adjustment unit VA3 is provided in the first and second inversion units wa1 to wd2 of the connection units 82a to 82d, but instead, the first inversion unit wa1. ˜wd1 and second inversion portions wa2 to wd2 may be provided. Alternatively, the third vibration adjustment unit VA3 may be provided in a region other than the reversing unit.

  As mentioned above, although embodiment of this technique was described, this technique is not limited only to the above-mentioned embodiment, Of course, a various change can be added.

  For example, in the above embodiment, the first to third vibration adjustment portions VA1 to VA3 are each configured by the plurality of concave portions 91 and 92 each having a circular opening shape, but the shape of each concave portion is not limited to a circular shape, and a groove Or at least part of the shape may be included.

  Each of the recesses is not limited to being formed only in the surface of the main surface 10s2, and may be provided on a ridge line including at least a portion of the main surface 10s2 in addition to the main surface 10s23.

In addition, this technique can also take the following structures.
(1) an annular frame having a first main surface and a second main surface opposite to the first main surface;
A drive unit provided on the first main surface and configured to vibrate the frame in a plane parallel to the first main surface;
An angular velocity around a first axis orthogonal to the first main surface is detected based on a deformation amount provided in the first main surface and parallel to the first main surface of the frame. A first detection unit;
A plurality of pendulum parts connected to the frame and vibrating in a plane parallel to the main surface in synchronization with the vibration of the frame;
A second detection unit that is provided in the plurality of pendulum units and detects an angular velocity around an axis orthogonal to the first axis based on a deformation amount of the plurality of pendulum units in the first axial direction; ,
A gyro sensor comprising: a first vibration adjustment unit that is provided on each of the second main surface and the inner peripheral edge portion and the outer peripheral edge portion of the frame and includes a plurality of concave portions.
(2) The gyro sensor according to (1) above,
The frame extends in a second axial direction orthogonal to the first axis and is opposed to each other in a third axial direction orthogonal to the first axis and the second axis. A pair of second beams extending in the third axial direction and facing each other in the second axial direction, and the first beam and the second beam. A plurality of connection parts for supporting one end of the plurality of pendulum parts,
The first vibration adjusting unit is provided in each of at least one of the first beam set and the second beam set.
(3) The gyro sensor according to (1) or (2) above,
A gyro sensor further comprising a second vibration adjustment unit provided with each of the plurality of pendulum units and including a plurality of recesses.
(4) The gyro sensor according to (3) above,
The second vibration adjustment unit is provided at a corresponding location for each of the plurality of pendulum units.
(5) The gyro sensor according to (3) or (4) above,
The second vibration adjustment unit is provided at a position symmetrical with respect to the center in the width direction of each of the plurality of pendulum units.
(6) The gyro sensor according to any one of (3) to (6) above,
The second vibration adjustment unit is provided on three or more virtual lines that are symmetrical with respect to the center in the length direction of each of the plurality of pendulum units.
(7) The gyro sensor according to any one of (1) to (6) above,
An annular base disposed around the frame;
A plurality of connecting portions that are provided between the frame and the base portion and support the frame so as to vibrate with respect to the base portion;
A gyro sensor further comprising: a third vibration adjusting unit that is provided in each of the plurality of connecting portions and includes a plurality of concave portions.
(8) The gyro sensor according to any one of (1) to (7) above,
The plurality of recesses have circular openings and are arranged at intervals from each other.
(9) The gyro sensor according to (8) above,
The said space | interval is a magnitude | size beyond the opening diameter of the said opening part.
(10) an annular frame having a first main surface and a second main surface opposite to the first main surface;
A drive unit provided on the first main surface and configured to vibrate the frame in a plane parallel to the first main surface;
An angular velocity around a first axis orthogonal to the first main surface is detected based on a deformation amount provided in the first main surface and parallel to the first main surface of the frame. A first detection unit;
A plurality of pendulum parts connected to the frame and vibrating in a plane parallel to the main surface in synchronization with the vibration of the frame;
A second detection unit that is provided in the plurality of pendulum units and detects an angular velocity around an axis orthogonal to the first axis based on a deformation amount of the plurality of pendulum units in the first axial direction; ,
An electronic apparatus comprising: a gyro sensor having a first vibration adjustment unit that is provided on each of the second main surface and the inner peripheral edge and the outer peripheral edge of the frame and includes a plurality of recesses.

DESCRIPTION OF SYMBOLS 1 ... Gyro sensor 10, 110 ... Frame 10s1 ... 1st main surface 10s2 ... 2nd main surface 11a, 11b, 12a, 12b ... Beam 13a-13d ... Connection part 21a-21d ... Pendulum part 31, 32 ... Piezoelectric drive Units 51a to 51d ... First piezoelectric detectors 71a to 71d ... Second piezoelectric detectors 91, 92 ... Recesses 100, 150 ... Sensor element 101 ... Vibrator body 200 ... Controller VA1 ... First vibration adjustment unit VA2 ... 2nd vibration adjustment part VA3 ... 3rd vibration adjustment part

Claims (10)

An annular frame having a first main surface and a second main surface opposite to the first main surface;
A drive unit provided on the first main surface and configured to vibrate the frame in a plane parallel to the first main surface;
An angular velocity around a first axis orthogonal to the first main surface is detected based on a deformation amount provided in the first main surface and parallel to the first main surface of the frame. A first detection unit;
A plurality of pendulum parts connected to the frame and vibrating in a plane parallel to the first main surface in synchronization with the vibration of the frame;
A second detection unit that is provided in the plurality of pendulum units and detects an angular velocity around an axis orthogonal to the first axis based on a deformation amount of the plurality of pendulum units in the first axial direction; ,
A gyro sensor comprising: a first vibration adjustment unit that is provided on each of the second main surface and the inner peripheral edge portion and the outer peripheral edge portion of the frame and includes a plurality of concave portions. The gyro sensor according to claim 1,
The frame extends in a second axial direction orthogonal to the first axis and is opposed to each other in a third axial direction orthogonal to the first axis and the second axis. A pair of second beams extending in the third axial direction and facing each other in the second axial direction, and the first beam and the second beam. A plurality of connection parts for supporting one end of the plurality of pendulum parts,
The first vibration adjusting unit is provided in each of at least one of the first beam set and the second beam set. The gyro sensor according to claim 1,
A gyro sensor further comprising a second vibration adjustment unit provided with each of the plurality of pendulum units and including a plurality of recesses. The gyro sensor according to claim 3,
The second vibration adjustment unit is provided at a corresponding location for each of the plurality of pendulum units. The gyro sensor according to claim 3,
The second vibration adjustment unit is provided at a position symmetrical with respect to the center in the width direction of each of the plurality of pendulum units. The gyro sensor according to claim 3,
The second vibration adjustment unit is provided on three or more virtual lines that are symmetrical with respect to the center in the length direction of each of the plurality of pendulum units. The gyro sensor according to claim 1,
An annular base disposed around the frame;
A plurality of connecting portions that are provided between the frame and the base portion and support the frame so as to vibrate with respect to the base portion;
A gyro sensor further comprising: a third vibration adjusting unit that is provided in each of the plurality of connecting portions and includes a plurality of concave portions. The gyro sensor according to claim 1,
The plurality of recesses have circular openings and are arranged at intervals from each other. The gyro sensor according to claim 8, wherein
The said space | interval is a magnitude | size beyond the opening diameter of the said opening part. An annular frame having a first main surface and a second main surface opposite to the first main surface;
A drive unit provided on the first main surface and configured to vibrate the frame in a plane parallel to the first main surface;
An angular velocity around a first axis orthogonal to the first main surface is detected based on a deformation amount provided in the first main surface and parallel to the first main surface of the frame. A first detection unit;
A plurality of pendulum parts connected to the frame and vibrating in a plane parallel to the main surface in synchronization with the vibration of the frame;
A second detection unit that is provided in the plurality of pendulum units and detects an angular velocity around an axis orthogonal to the first axis based on a deformation amount of the plurality of pendulum units in the first axial direction; ,
An electronic apparatus comprising: a gyro sensor having a first vibration adjustment unit that is provided on each of the second main surface and the inner peripheral edge and the outer peripheral edge of the frame and includes a plurality of recesses.

Images