JPH11351874A - Angular velocity sensor and its adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the offset of a detection signal being generated due to the unneeded vibration of a vibrator and its temperature drift in an angular velocity sensor for detecting an angular velocity using the vibrator consisting of a piezoelectric body in the shape of a tuning fork or in a shape where a plurality of tuning forks are combined. SOLUTION: In an angular velocity sensor with a vibrator 2 in the shape of a tuning fork consisting of a piezoelectric body, the vibrator 2 is excited and vibrated in the direction of a drive axis via a self-excitated oscillation circuit 40 and a ridge near the root of the vibrator 2 for greatly affecting the vibration characteristics of the vibrator 2 is trimmed so that a detection signal (offset) obtained via a detection circuit 50 at that time (when no angular velocity is inputted) can be reduced. Also, the ridge to be trimmed is determined by inputting a reference signal Vr for indicating the actual vibration state of the vibrator 2 and a detection signal to a locking amplifier 60 and detecting the phase relationship for the reference signal Vr of the detection signal, thus achieving an angular velocity sensor for efficiently adjusting the vibration characteristics of the vibrator 2 and for accurately detecting an angular velocity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration type angular velocity sensor used for vehicle control, navigation of a motor vehicle, prevention of camera shake of a video camera, and the like, and an adjustment method for adjusting vibration characteristics of a vibrator constituting the angular velocity sensor. .

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Unexamined Patent Application Publication No.
As disclosed in Japanese Patent Laid-Open Publication No. 0-101, there is provided a vibrator made of a piezoelectric material formed in a tuning fork shape by a pair of arms and a connecting part connecting the arms, and driving the vibrator in the arrangement direction of the arms. 2. Description of the Related Art There is known an angular velocity sensor that detects a Coriolis force applied to a vibrator when an angular velocity is input from a change state of vibration of the vibrator in a detection axis direction orthogonal to a drive shaft while constantly vibrating in an axial direction.

In this type of angular velocity sensor, a vibrator can be manufactured only by forming an electrode for driving (excitation) or detecting vibration on the outer wall surface of a piezoelectric body formed in a tuning fork shape. Compared to the generally used type of angular velocity sensor in which the vibrator is formed of metal and a piezoelectric body is bonded to the surface, the number of parts is smaller and the structure and the manufacturing process are simpler. There is.

[0004]

However, in the angular velocity sensor in which the vibrator is composed of the piezoelectric material as described above, the resonance frequency (drive frequency) of the vibrator in the drive axis direction and the resonance frequency of the vibrator in the detection axis direction are different. Because the frequency (detection frequency) is close, when the angular velocity sensor is vibrating in the drive axis direction at the drive frequency, the vibration part moves in the detection axis direction even though no angular velocity is applied to the angular velocity sensor. (Vibration) (unnecessary vibration), and an unnecessary detection signal (offset) is generated.

If the offset signal is always constant regardless of the use environment of the angular velocity sensor, the angular velocity can be accurately detected by removing the offset from the detection signal obtained at the time of detecting the angular velocity. However, since the unnecessary vibration, and hence the offset, changes depending on the temperature of the vibrator, the conventional angular velocity sensor has a problem that it is difficult to accurately detect the angular velocity due to the unnecessary vibration of the vibrator. .

On the other hand, Japanese Patent Application Laid-Open No. 6-289043 discloses that a pair of arm portions is formed by joining a drive element and a detection element each having a piezoelectric body attached to a metal plate so that the plate surfaces are orthogonal to each other. Then, in the angular velocity sensor having the vibrator formed in a tuning fork shape by connecting one end of the arm portion through a connecting portion, the detection is performed by shaving the detecting element arranged at the tip end side of each arm portion. It is disclosed to reduce noise contained in a signal. Therefore, it is conceivable to reduce the offset temperature drift of an angular velocity sensor provided with a vibrator of this type by using the technology disclosed in this publication for adjusting a vibrator made of a piezoelectric body formed in a tuning fork shape.

However, it has been found that when a vibrator made of a tuning-fork-shaped piezoelectric material is adjusted according to the adjusting method disclosed in the above publication, the vibration characteristics of the vibrator cannot be adjusted efficiently. This is an adjustment method disclosed in the above publication, which is an adjustment method of a vibrator configured by combining a driving element and a detection element in which a piezoelectric body is attached to a metal plate, and the piezoelectric body itself is formed into a tuning fork shape. This is because it is not a method of adjusting the formed vibrator.

That is, in the vibrator of the type disclosed in the above-mentioned publication, the noise component of the detection signal can be reduced by cutting off the detecting element on the arm tip end side which directly affects the detection signal. In a vibrator of a type in which a piezoelectric body is formed in a tuning fork shape, even if the tip end side of the vibrator on which a detection electrode is arranged is shaved, the vibration characteristics of the vibrator cannot be largely changed. However, the adjustment method disclosed in Japanese Patent Application Laid-Open No. H11-157572 cannot reduce offset and offset temperature drift caused by unnecessary vibration of the vibrator.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has been made in consideration of the above problem. And its temperature drift can be sufficiently reduced.

[0010]

According to the first aspect of the present invention, there is provided an angular velocity sensor for connecting at least one pair of arms formed in a prismatic shape and arranged in parallel with each other. A vibrator made of a piezoelectric material formed in a tuning fork shape or a shape obtained by combining a plurality of tuning forks. And, in the vibrator, near the base where each arm portion protrudes from the connecting portion,
Irregularities for adjusting vibration characteristics are formed.

That is, in a vibrator formed in a tuning fork shape or a shape obtained by combining a plurality of tuning forks by a piezoelectric body, the vibration characteristics can be efficiently improved even if the tip end side of each arm is cut in accordance with the adjustment method disclosed in the above publication. Since the adjustment cannot be performed, the present inventor has found, as a result of intensive studies, that the vicinity of the base of the vibrator is found as a portion that most affects the vibration characteristics in this type of vibrator, and that irregularities are formed in that portion. Thus, the angular velocity sensor of the present invention in which the vibration characteristics are optimally adjusted has been completed.

According to the angular velocity sensor of the present invention,
Since the vibration characteristics are adjusted by forming irregularities near the base, an angular velocity sensor that can detect the angular velocity without being affected by unnecessary vibration of the vibrator can be realized, and the vibration formed in a tuning fork shape by the piezoelectric body The offset of the detection signal and the temperature drift thereof in the angular velocity sensor having the element can be sufficiently reduced.

The shape obtained by synthesizing a plurality of tuning forks is a shape formed by connecting a plurality of sets of a pair of arms arranged in parallel with each other and connecting these arms with one connecting portion. As described in the embodiments described later, for example, if two pairs of arms are all arranged in parallel and one end thereof is connected by a connecting part, a comb-shaped four arms project from the connecting part in the same direction. For example, if two pairs of arm portions are arranged along the axial direction, and each arm portion is connected by a connecting portion, an H-shaped shape obtained by combining two sets of tuning forks is obtained.

Here, the vicinity of the base of the vibrator where the irregularities are formed for adjusting the vibration characteristics affects the vibration characteristics of the vibrator, and the vibration characteristics can be changed by forming the irregularities. Any area may be used, but the present inventor:
The optimum region was found through experiments and the like described in Examples below. In the case where the unevenness for adjusting the vibration characteristic is formed on the arm portion as described in claim 2, the height of the connecting portion along the longitudinal direction of the arm portion from the base of the oscillator is 170 degrees. %, And when the unevenness for adjusting the vibration characteristics is formed on the connecting portion, 70% of the height of the connecting portion along the longitudinal direction of the arm portion from the base of the vibrator.
The area within.

Therefore, if the angular velocity sensor has a vibrator in which unevenness is formed in one or both of these regions as described in claim 2, extremely good vibration characteristics can be obtained. This is an angular velocity sensor having a vibrator and having sufficiently reduced offset and temperature drift.

On the other hand, forming irregularities near the base of the vibrator for adjusting the vibration characteristics means adjusting the rigidity of the vibrator. Specifically, the rigidity of the vibrator can be adjusted. The cross-sectional shape of the vibrator may be changed by a method such as attaching a suitable member (for example, a metal piece or the like) or shaving a part of the vibrator. In addition, when a part of the vibrator is shaved in the area as in the angular velocity sensor according to claim 3, the vibration characteristics can be adjusted more than when the adjusting member is attached to the vibrator. Can be easily performed, which is preferable.

When an angular velocity sensor in which the characteristics of the vibrator are adjusted by shaving a part of the vibrator is manufactured as described above, the wall surface of the vibrator may be shaved. In the vibrator, at least one of the ridges along the longitudinal direction of the vibrating part may be cut off. According to the angular velocity sensor according to the fourth aspect, in which the vibration characteristics of the vibrator are adjusted by cutting the ridge line of the vibrator in this manner, the adjustment operation is simplified, and thus the manufacturing cost can be reduced.

On the other hand, the invention according to claims 5 to 9 relates to a method for actually adjusting the vibration characteristics of the vibrator in the angular velocity sensor according to claims 1 to 4. According to the adjusting method of the fifth aspect, an AC voltage is applied to the drive electrode of the vibrator to vibrate the vibrator in the drive axis direction, and at this time, a pair of detection electrodes formed on each arm portion are driven. Irregularities are formed near the root of the connecting portion so that the unnecessary signal component of the detection signal obtained through the connection becomes small. Therefore, according to the present invention, it is possible to reduce an unnecessary signal (offset) generated in the detection signal due to unnecessary vibration of the vibrator, and furthermore, to reduce the temperature drift thereof, and to realize an angular velocity sensor that can obtain good angular velocity detection characteristics.

Further, according to the adjusting method of the sixth aspect, in the arm portion, an area within 170% of the height of the connecting portion along the longitudinal direction of the arm portion from the base of the vibrator, or In the connecting portion, the unevenness is formed in a region within 70% or less of the height of the connecting portion along the longitudinal direction of the arm portion from the base of the vibrator, or in both regions, whereby the vibrator Adjust vibration characteristics. For this reason, the characteristic adjustment of the vibrator can be performed for the region that most affects the vibration characteristic, and the adjustment operation can be performed efficiently.

In the adjusting method according to a seventh aspect of the present invention, a part of the vibrator is shaved in the area, and in the adjusting method according to the eighth aspect, the vibrator further extends along the longitudinal direction of the arm in the area. Cut at least one of the ridges of the transducer. Therefore, according to each of these adjustment methods, the angular velocity sensor according to claim 3 or 4 can be realized, and the adjustment operation is performed by adjusting the metal piece or the like to the vibrator as described above. Compared to the case where a member is attached or the case where the wall surface of the vibrator is cut, the manufacturing cost of the angular velocity sensor can be reduced because it can be performed more easily.

Further, when adjusting the vibration characteristics of the vibrator by shaving the ridge line of the vibrator, one of the ridge lines of the arm portion constituting the vibrator may be shaved. For example, as described in claim 9, two ridge lines at diagonal positions may be cut off in at least one of the pair of arms on which the drive electrodes are formed, or As described in claim 10, in the pair of arm portions on which the drive electrodes are formed, two ridge lines at a center position between the arm portions and at symmetric positions about an axis parallel to the arm portions. May be cut.

According to the adjusting method of the ninth or tenth aspect, the present invention is particularly advantageous when adjusting a comb-shaped vibrator having a plurality of pairs of arm portions projecting in the same direction from the connecting portion. It has the effect. In other words, the comb-shaped (in other words, multi-legged) vibrator has more vibration modes than the tuning-fork-shaped vibrator. Therefore, in such a vibrator, it is desirable to minimize the influence of the vibration for detecting the angular velocity (that is, the vibration in the drive axis direction and the detection axis direction) from the other vibration modes. It is better to disperse the adjustment points than to set one of the ridges and cut the ridge deep, wide and long. And in a comb-shaped vibrator,
Since the vibration of the driving arm on which the drive electrode is formed is the largest, the vibration of the arm has the greatest effect on the angular velocity detection accuracy.

Therefore, when adjusting the vibration characteristics of the comb-shaped vibrator, as described in claim 9, one of the pair of driving arms is at a diagonal position. The two ridges may be cut or, as described in claim 10, in a pair of driving arms, a center position between the respective arms and an axis parallel to the respective arms. By shaving the two ridge lines at symmetrical positions, the vibration characteristics of the vibrator are not affected by other vibration modes of the vibrator when detecting the angular velocity.
The adjustment can be made efficiently and with high precision.

In the adjusting method according to the tenth aspect, since both the pair of driving arms are shaved, it is possible to prevent the vibration balance of the vibrator from being deteriorated by the adjustment. As compared with the case where only one of the arms is cut, the vibration characteristics of the vibrator can be adjusted more favorably.

In the case where the vibration characteristic of the vibrator is adjusted by shaving the ridge of the vibrating portion as described in claim 7 to claim 10, the shaving of the ridge is performed according to claim 11. It is sufficient to adjust the length of the arm portion along the longitudinal direction, the depth to the vibrator when cutting the ridge line, or both.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view illustrating the entire configuration of the angular velocity sensor according to the embodiment, and FIG. 2 is an explanatory diagram illustrating the vibrator according to the embodiment as viewed from front, rear, left and right.

As shown in FIG. 1, the angular velocity sensor of the present embodiment has a vibrator formed in a tuning fork shape by a pair of left and right arms 4, 6 and a connecting portion 8 connecting one end of each of the arms 4, 6. 2 is provided. The arm portions 4 and 6 and the connecting portion 8 of the vibrator 2 are each in the shape of a quadrangular prism, and the vibrator 2 is manufactured by integrally forming these components with a piezoelectric body.
The piezoelectric body constituting the vibrator 2 can be a ceramic piezoelectric body such as PZT, quartz, or the like. However, the vibrator 2 of this embodiment can be set to any polarization direction and is easy to manufacture. PZT is used.

Next, as shown in FIG. 2A, one surface (X1 surface) of the vibrator 2 having a concave shape is provided with a pair of drive electrodes 12 extending from the connecting portion 8 to the arms 4 and 6.
a, 12b are formed, and these drive electrodes 12a, 12b are formed.
b, the monitor electrodes 14a, 14b and the temporary GND electrodes 16a, 16b
And polarization electrodes 18a and 18b are formed in this order, and pad electrodes 20a and 20b for extracting a detection signal are formed at the tips of the arms 4 and 6, respectively.

Then, the drive electrodes 12a and 12b pass through the connecting portion 8 and the opposing surfaces of the arms 4, 6 facing each other, and the left and right outer surfaces (Y1, Y
2) and the monitor electrodes 14a and 14
b is formed on each of the facing surfaces of the arms 4 and 6, respectively, and the provisional GND electrodes 16a and 16b are
The polarization electrodes 18a and 18 are formed on the Y1 and Y2 surfaces, respectively.
b is formed in the entire width direction from the Y1, Y2 surface side of each arm portion 4, 6 to the opposing surface side, and the pad electrodes 20a and 20b are respectively formed on the Y1, Y2 surface side of each arm portion 4, 6 respectively. Is formed. In addition, each of the polarization electrodes 18a and 18b is
The temporary GND electrode 16 is connected via the short-circuit electrodes 26a and 26b.
a, 16b are respectively connected (short-circuited).

On the other hand, as shown in FIGS. 2B and 2C, the detection electrodes 22a and 18b are located on the Y1 and Y2 surfaces of the arms 4 and 6 at positions corresponding to the polarization electrodes 18a and 18b, respectively.
On the other surface (X2 surface) of the vibrator 2 having a concave shape, drive electrodes 12a and 12b, monitor electrodes 14a and 14b, and a detection electrode 18a are formed as shown in FIG. , 18b as a reference electrode for
An ND electrode 24 is formed. The detection electrodes 22a,
22b is the Y1, Y2 surface of each arm part 4, 6;
It is formed at the position on the X2 plane side from the center.

Then, the provisional GND electrode 24 on the X2 side and the X
The temporary GND electrodes 16a and 16b on the first surface are the short-circuit electrodes 2 formed on the Y1 and Y2 surfaces of each arm 4.6, respectively.
They are connected (short-circuited) to each other via 8a and 28b. Further, the pad electrodes 20a, 20b on the X1, X2 surface side
And the detection electrodes 22a and 22b on the Y1 and Y2 surfaces are connected (short-circuited) to each other via detection signal extraction electrodes (extraction electrodes) 30a and 30b formed on the Y1 and Y2 surfaces, respectively. .

Note that the vibrator 2 of the present embodiment has detection electrodes 22a and 22b and short-circuit electrodes 28 formed on the Y1 and Y2 planes.
a, 28b and the respective electrodes except the extraction electrodes 30a and 30b (that is, the electrodes on the X1 and X2 planes) are formed on the piezoelectric body.
By applying a voltage between the electrodes formed on the X1 and X2 planes, the piezoelectric body is moved from the X1 plane to the X2 plane (FIG. 1).
To the direction indicated by the arrow), and then Y1, Y2
The detection electrodes 22a and 22b and the short-circuit electrodes 28a and 2
8b and the extraction electrodes 30a and 30b, respectively,
Plane-side temporary GND electrode 24 and X1 plane-side temporary GND electrode 16
a, 16b, pad electrodes 20a, 20b on the X1 side and Y
The detection electrodes 22a and 22b on the Y1, Y2 side are short-circuited, respectively.

Next, in the vibrator 2 thus manufactured, the end face on the connecting portion 8 side is attached to the pedestal portion 32b of the supporter 32 having a cross section of an E-shape with an adhesive (for example, an epoxy-based adhesive). Then, the main body side of the supporter 32 is fixed to the surface of the plate-like base 36 by welding or bonding via a spacer 34, so that the back surface (X2 surface) is Is fixed so as to face the surface.

The supporter 32 has a pedestal portion 32 for joining the vibrator 2 to a main body fixed to a base 36 via a spacer 34 via a neck portion 32a for absorbing vibration.
b, and is integrally formed in a D-shaped cross section with a metal such as 42N, for example. Further, the base 36 is for fixing the vibrator 2 directly or via a vibration-proof rubber to a housing of the angular velocity sensor or a vehicle body or the like for which an angular velocity is to be detected. The base 36 has eight terminals T1 to T8 corresponding to the drive electrodes 12a and 12b, the monitor electrodes 14a and 14b, the temporary GND electrodes 16a and 16b, and the pad electrodes 20a and 20b formed on the vibrator 2. It is erected. Each terminal T1-T8
Is for relaying each electrode to a detection circuit (not shown), and each electrode and terminals T1 to T8 are
They are connected by wire bonding via wires W1 to W8, respectively. Note that the base 36 and the terminals T1 to T8 are electrically insulated.

Next, when detecting the angular velocity using the angular velocity sensor of the present embodiment configured as described above, the terminals T5 and T6 are grounded by a signal line (not shown), so that the provisional GND electrode 16a, 16b, a polarization electrode 18a,
18b, Temporary GND electrode 24 is grounded to a reference potential. Then, an AC drive signal having a phase difference of 180 degrees is input to each of the drive electrodes 12a and 12b via terminals T1 and T2 connected to the drive electrodes 12a and 12b.

The drive signal is an AC signal that changes positively and negatively around the reference potential, and its frequency is shifted in the direction of the drive axis (Y axis shown in FIG. 1), which is the direction in which the left and right arms 4 and 6 are arranged. Is the resonance frequency (drive frequency) of the vibrator 2. When each of the electrodes is grounded to the reference potential, the terminals T5 and T6 may be directly grounded to the ground (ground). For example, a constant potential of 2.5 V may be applied to the terminals T5 and T6. The bias may be applied so that That is, the reference potential is directly
Indirectly, any ground reference potential may be used.

The driving electrodes 12a, 12b
When an AC drive signal is input to the
a, 12b and the temporary GND electrode 24 on the X2 plane are applied with AC voltages having inverted phases, respectively.
The arms 4 and 6 resonate in the direction of the drive shaft (Y axis).
At the time of this driving, outputs from the monitor electrodes 14a and 14b (specifically, currents flowing between the monitor electrodes 14a and 14b and the temporary GND electrode 24) are monitored via the terminals T3 and T4. The drive signal is controlled so that the amplitude of the units 4 and 6 in the Y-axis direction becomes constant even when the temperature changes (self-excited control oscillation).

That is, in the angular velocity sensor of the present embodiment, in order to vibrate the vibrator 2 at the driving frequency, FIG.
A self-excited oscillation circuit 40 as shown in FIG. 1 is provided, an output (AC voltage) from an amplitude control circuit (a so-called AGC circuit) 42 is supplied to the drive electrode 12b, and the output (AC voltage) is supplied to an inversion circuit 44.
The AC voltage with a phase difference of 180 degrees inverted by
2a, and the vibration state of the vibrator 2 caused by the voltage application is displayed on the monitor electrodes 14a and 14b.
Is converted into a voltage signal by a charge amplifier circuit 46, and this voltage signal is fed back to an amplitude control circuit 42 via a buffer circuit 48, whereby the buffer circuit 4 is operated by the operation of the amplitude control circuit 42.
The vibrator 2 is caused to self-oscillate so that the signal level from 8 (in other words, the amplitude of the vibrator 2 in the drive axis direction) is constant.

When an angular velocity Ω about the Z axis parallel to the arms 4 and 6 is input during the self-excited oscillation of the vibrator 2 as described above, the arms 4 and 6 Vibrates in the X-axis direction (detection axis direction) penetrating the X1 and X2 planes due to Coriolis force, and the vibration component in the X-axis direction
2a, 22b and the current flowing between the temporary GND electrode 24. Therefore, when detecting angular velocity, the current is
A terminal T7 connected to the detection electrodes 22a and 22b,
The signal is fetched through T8 and is detected by a detection circuit 50 as shown in FIG.
First, the current between these electrodes is converted into a voltage signal by current-voltage conversion circuits 52 and 54, respectively, and further, each voltage signal is differentially amplified using a differential amplifier circuit 56. As a result, a voltage signal corresponding to the vibration component of each of the arm units 4 and 6 in the detection resonance mode is generated, and this is output as a detection signal representing the angular velocity around the Z axis.

When the angular velocity Ω around the Z-axis is detected using the angular velocity sensor of the present embodiment, the accuracy of detecting the angular velocity Ω decreases when the above-described offset or its temperature drift occurs. Therefore, in the present embodiment, adjustment is performed to suppress unnecessary vibration of the vibrator 2 that causes the offset and the offset temperature drift to zero or below a predetermined threshold.

Hereinafter, this adjusting method will be described. When performing this adjustment work, as shown in FIG. 3, the self-excited oscillation circuit 40 is actually mounted in a state where the angular velocity sensor is provided with the angular velocity detection circuit unit including the self-excited oscillation circuit 40 and the detection circuit 50. At this time (when the angular velocity is not input), the detection signal (that is, the offset) output from the detection circuit 50 and the actual vibration state of the vibrator 2 input to the amplitude control circuit 42 by the self-excitation circuit 40 are shown. Signal to be used.

That is, the input signal to the amplitude control circuit 42 is input as a reference signal Vr to a lock-in amplifier (so-called synchronous detection circuit) 60 together with a detection signal, and the lock-in amplifier 6
0, a quadrature signal component V1 (= Asin) having a phase difference of 90 degrees with respect to the reference signal Vr from the detection signals.
φ), a signal component V2 in phase with the reference signal Vr (= Acos
φ) or a signal component obtained by combining them is extracted. In the case of the orthogonal signal component V1, the detection signal is the reference signal V
It is determined whether the phase is shifted by 90 degrees or -90 degrees (that is, 270 degrees) with respect to r. In the case of the in-phase signal component V2, the detection signal is in-phase with the reference signal Vr having a phase difference of zero. And a phase difference of 180 degrees, and the trimming position of the vibrator 2 is determined from the determination result (that is, the phase of the offset with respect to the reference signal Vr), and the signal components V1, V2,
Alternatively, the ridge near the root of the vibrator 2 is trimmed using the luter 70 or the like until the magnitude (amplitude A) of the combined component becomes zero or less than a predetermined threshold (see FIG. 4A). Note that the root of the vibrator 2 is the upper end position of the connecting portion 8 from which the respective arm portions 4 and 6 are protruded.

For example, when the in-phase signal component V2 is monitored, as shown in FIG. 5A, if the in-phase signal component V2 is in phase with the reference signal Vr (the phase difference is zero), A ridge portion which is a boundary between the X1 plane and the Y1 plane of the left arm unit 4 is trimmed, and as shown in FIG. 5B, the in-phase signal component V2 is out of phase with the reference signal Vr (a phase difference of 180 degrees).
In the case of, the ridge portion which is the boundary between the X1 plane and the Y2 plane of the right arm 6 is trimmed. Then, the in-phase signal component V2, and hence the unnecessary vibration of the vibrator 2, is reduced, so that the signal component V2 becomes substantially zero (or a predetermined threshold value), and the unnecessary vibration is sufficiently small. Until
Continue trimming. When the quadrature signal component V1 is monitored, or when the quadrature signal component V1 and the in-phase signal component V
5 while monitoring the composite signal with
Unnecessary vibration of the vibrator 2 can be reduced by trimming the vibrator 2 according to the procedure shown in FIGS.

Next, the vibrator 2 is actually operated in such a procedure.
FIG. 6 shows the result of adjusting (Sample 1, Sample 2). As shown in FIG. 6A, in the case of sample 1, before adjustment, the in-phase signal component V2 (hereinafter simply referred to as offset V2) was + 83.3 ° / sec. By trimming the ridge portion, which is the boundary between the X1 plane and the Y1 plane, the offset V2 becomes +21.8.
° / sec. As a result, before adjustment, +19
The offset temperature drift of ° / sec. Could be reduced to + 7.6 ° / sec. By trimming.

On the other hand, as shown in FIG.
In the case of, before the adjustment, the offset V2 is -99.1 ° /
sec., the X1 plane of the right arm 6 and Y
The offset V2 was reduced to -23.6 ° / sec. By trimming the ridge portion which is the boundary between the two surfaces. As a result, the offset temperature drift of −18.2 ° / sec. Before the adjustment was reduced to −8.2 by trimming.
° / sec.

Therefore, it can be seen that the unnecessary vibration of the vibrator 2 can be reduced and the offset and its temperature drift can be reduced by the above-described adjustment method. Next, the relationship between the trimming amount and the offset V2 and the offset temperature drift will be described.

As shown in FIG. 7, when the offset V2 is in phase with the reference signal Vr (the phase difference is zero), the ridge which is the boundary between the X1 plane and the Y1 plane of the left arm unit 4 is adjusted by the above adjustment method. When the portion is trimmed near the base of the vibrator 2, both the offset V2 and its temperature drift decrease, but when the trimming amount is further increased, the phase of the offset V2 and the reference signal Vr is inverted. Reverse phase (phase difference 1
80 °), and the offset V2 and its temperature drift increase. Next, in a state where the phase relationship between the offset V2 and the reference signal Vr is inverted and the respective signals are in opposite phases, the ridge portion which is the boundary between the X1 plane and the Y2 plane of the right arm 6 is trimmed. Then, the offset V2 and its temperature drift decrease again. Therefore, even when trimming is excessively performed at the time of adjusting the vibration characteristics of the vibrator 2 by trimming, the vibration characteristics can be easily readjusted by changing the trimming position (ridge line).

The size of the vibrator 2 of this embodiment is such that the width of each of the arms 4 and 6 in the Y-axis direction (lateral direction) is about 2.0 m.
m, the gap (width in the Y-axis direction) between the arm portions 4 and 6 is about 0.6 mm, the height of the connecting portion 8 in the Z-axis direction is about 3 mm, and the X-axis of the arm portions 4 and 6 and the connecting portion 8 Direction thickness is about 2.1
mm, the supporter 3 of the connecting portion 8 from the tip of the arm portion 4 or 6
The length up to the end face on the second side is about 20 mm. The length of the supporter 32 in the Z-axis direction is about 4 mm.

Then, when the optimum region for adjusting the vibration characteristics by trimming was examined in the vibrator 2 of this size, the results shown in FIGS. 8 and 9 were obtained. That is, first, as shown in FIG. 8A, when the vibration characteristics of the vibrator 2 are adjusted by trimming the arm portions 4 and 6 near the base of the vibrator 2, FIG. As shown, if the region from the root of the vibrator 2 to 1 mm from the root is trimmed, the offset V2 and its temperature drift greatly change, but the trimming region is moved from the root of the vibrator 2 to the tip end of the arms 4 and 6. As the size increases, the offset V2 and its temperature drift change slowly, and in a region where the length of the trimming from the base is about 5 mm or more, even if the trimming is performed, the offset V2 and the temperature drift hardly change. all right.

The trimming length is equal to the vibrator 2
As a result of various experiments, when adjusting the vibration characteristics of the vibrator 2 by shaving the arms 4 and 6, the Z of the connecting portion 8 starts from the base of the vibrator 2.
170 for the height in the axial direction (3 mm in this embodiment)
% (In the present embodiment, approximately 5.1 mm), it is sufficient to trim the region. Even if the trimming region is further expanded, the effect of improving the vibration characteristics cannot be obtained.
It was found that the only effect was to lower the strength of the.

On the other hand, when the vibration characteristics of the vibrator 2 are adjusted by trimming the connecting portion 8 near the base of the vibrator 2 as shown in FIG. As described above, if the region from the root of the vibrator 2 to 1 mm from the root is trimmed, the offset V2 and its temperature drift greatly change, but the trimming region is expanded from the root of the vibrator 2 to the supporter 32 side of the connecting portion 8. As you go,
It has been found that the offset V2 and its temperature drift change slowly, and the offset V2 and the temperature drift hardly change even when trimming is performed in a region where the length of the trimming from the base is about 2 mm or more.

The trimming length is determined by the vibrator 2
As a result of various experiments, when adjusting the vibration characteristics of the vibrator 2 by shaving the connecting portion 8, the height of the connecting portion 8 in the Z-axis direction from the base of the vibrator 2 is varied. An area up to 70% (about 2.1 mm in this embodiment) with respect to (3 mm in this embodiment) may be trimmed, and even if the trimming area is further expanded, the vibration characteristics are improved. No effect was found.

Therefore, in the angular velocity sensor for detecting the angular velocity using the vibrator 2 made of a piezoelectric material formed in a tuning fork shape as in the present embodiment, the vibration characteristics of the vibrator are adjusted to stably maintain the angular velocity. In order to enable high-precision detection, on the basis of the height of the connecting portion 8 along the longitudinal direction of the arm portion, from the base of the vibrator 2 to 170% of the height from the root of the vibrator 2 to the arm portions 4 and 6. Area is trimmed and vibrator 2
From the base to the connecting portion side, the region up to 70% of the height may be trimmed.
It can be seen that even if the trimming is performed continuously to, the trimming should be performed in each of these areas.

When the vibration characteristics of the vibrator 2 are actually adjusted by the above-described method, for example, the trimming depth is made constant, and the length of the trimming portion in the Z-axis direction is adjusted within the above-mentioned region. Alternatively, the depth may be adjusted while keeping the length constant in the above-described region. However, in consideration of the damage to the vibrator 2, the depth of the trimming is desirably set to about 0.5 mm in this embodiment.

As described above, according to the angular velocity sensor of the present embodiment, the vibration characteristic of the vibrator 2 is determined by trimming (cutting) the ridgeline near the base where each of the arms 4 and 6 protrudes from the connecting portion 8. Therefore, the offset, which is an unnecessary signal component included in the detection signal, can be reduced, and a stable detection signal with less temperature drift can be obtained. For this reason, the detection accuracy of the angular velocity by the angular velocity sensor can be improved.

The adjustment of the vibration characteristics of the vibrator 2 can be performed in a state where the vibrator 2 is mounted on the base 36 and a circuit unit for detecting the angular velocity is mounted, that is, before the angular velocity sensor is shipped. Since it is possible, the manufacturing and adjustment process of the angular velocity sensor is simplified. In addition, at the time of the adjustment, the vicinity of the base that greatly affects the vibration characteristics of the vibrator 2 is trimmed, so that the adjustment operation can be performed efficiently. Therefore, according to the present embodiment, an angular velocity sensor that can obtain excellent detection accuracy can be provided at low cost.

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various embodiments can be adopted. For example, in the above embodiment, the trimming position (ridge line) is determined from the phase relationship between the detection signal and the reference signal Vr, and a signal component (offset of zero or 180 degrees) in phase with the reference signal Vr extracted from the detection signal (offset). ) When V2 is completely in phase (zero phase difference) with reference signal Vr, X1 plane of left arm 4 and Y
When the offset V2 is out of phase with the reference signal Vr (the phase difference is 180 degrees), the ridge line which is the boundary between the X1 plane and the Y2 plane of the right arm 6 is trimmed. Although it was explained as trimming the part,
Since the position of the ridge line to be trimmed determined from such a phase relationship differs depending on the shape and size of the vibrator 2, if the type of the vibrator is different, the trimming is performed according to the phase relationship between the detection signal and the drive signal. The ridge line to be reversed may be reversed. Therefore, the ridge line to be trimmed first according to the phase relationship between the detection signal and the drive signal may be appropriately set according to the type of the vibrator to be adjusted.

In the case of a tuning fork-shaped vibrator, FIG.
As shown in (b), the change in the vibration characteristic obtained when the ridge line P1 on the outer side (Y1 side) of the X1 plane of the left arm unit 4 is cut is the ridge line P2 on the inner side of the X2 plane of the left arm unit 4.
2. The same can also be realized by cutting the ridge line P3 inside the X1 plane of the right arm section 6 or the ridge line P4 outside the X2 plane of the right arm section 6. The change in the vibration characteristic obtained when the ridge line P5 on the outer side (Y2 side) of the X1 plane of the right arm 6 is reduced
The same can be realized by cutting the ridge line P6 inside the surface, the ridge line P7 inside the X1 surface of the left arm unit 4, or the ridge line P8 outside the X2 surface of the left arm unit 4. Therefore, at the time of the above adjustment, an easy-to-operate ridgeline may be appropriately selected from among ridgelines having similar characteristic changes, and trimming may be performed.

On the other hand, in the above embodiment, the angular velocity sensor provided with the tuning-fork-shaped vibrator 2 and the method of adjusting the vibration characteristics thereof have been described. However, the present invention relates to a pair of prisms formed in a prismatic shape and connected by a connecting portion. The present invention can be applied to any angular velocity sensor provided with a vibrator having the above arm portion, and the shape of the vibrator to which the present invention can be applied is not limited to the tuning fork shape.

That is, as an angular velocity sensor for detecting an angular velocity using a tuning fork formed by a connecting portion and a pair of arms, as shown in FIGS. 10 and 11, two arms constituting the tuning fork are used. Are provided, and each of these arm portions 10
12, 104, 105, 106 are arranged in parallel, and one end thereof is connected by a common connecting portion 102, thereby using a comb-shaped vibrator 100, or FIG.
As shown in FIG. 2, two sets of two arm portions constituting the tuning fork are provided, and the arm portions 203, 204 and 205,
A configuration using the vibrator 200 formed in an H shape by arranging and connecting the 206 on both sides of the connecting portion 202 is also conceivable.

Also in these angular velocity sensors, if the vibration characteristics of the vibrator are adjusted in the same manner as in the above embodiment, the offset which is an unnecessary signal component included in the detection signal is reduced, and the temperature is reduced. A stable detection signal with little drift can be obtained, and the detection accuracy of the angular velocity can be improved.

Hereinafter, the configuration of each angular velocity sensor shown in FIGS. 10 to 12 and a method of adjusting the same will be briefly described.
Vibrator 100 of angular velocity sensor shown in FIGS. 10 and 11
Is a so-called four-legged tuning fork in which two sets of tuning forks with different intervals between the arms 103, 104 and 105, 106 are combined. Are arranged in a narrow interval, and the connecting portions of the tuning forks are connected (comb shape). As in the case of the vibrator 2 shown in FIG. 1, a supporter 107 having a torsion beam 108 in the center is formed of an adhesive material or the like for the connecting portion 102 of the vibrator 100 in the same manner as the vibrator 2 shown in FIG. The supporter 107 further connects the arm portions 103 to 106 to each other.
In order to dispose the base 111 in parallel at a predetermined distance from the base 111, the base 111
The upper part is fixed by welding or the like.

FIG. 10 is a perspective view showing the entire structure of the angular velocity sensor provided with the comb-shaped vibrator 100, and FIG.
FIG. 4 is an explanatory diagram showing a state in which the vibrator 100 is viewed from front and rear (X1 plane, X2 plane) and left and right (Y1 plane, Y2 plane).
The vibrator 100 is formed in a comb shape by, for example, machining PZT by dicing or the like. The four arms 103 to 10 constituting the vibrator 100
6, a pair of arm portions 10 constituting a central tuning fork portion.
The vibrator 100 is attached to each of the arm portions 103-1 to 3-4.
The electrodes for vibrating in the arrangement direction (Y-axis direction) of the pair 06 are formed, and a pair of arm portions 10 constituting an outer tuning fork portion are formed.
5 and 106, each arm portion 1 added to the vibrator 100 is provided.
Electrodes for detecting the angular velocity Ω around the Z-axis parallel to the central axes of 03 to 106 are formed.

That is, as shown in FIG.
The drive electrodes 112 and the monitor electrodes 113 are respectively formed on the X1 surface (the surface opposite to the base 111) of the X-rays 3 and 104, and the X2 surface (the back surface facing the base 111) is formed on the X3 surface. Temporary GND electrode 12 for grounding to a reference potential
0 is formed. And each of the arm portions 103, 10
4 drive electrode 112 and monitor electrode 113
Are connected to each other on the X1 plane of the connecting part 102, and are formed on the X2 plane of the arm parts 103 and 104, respectively.
The electrodes 120 are connected to each other on the X2 plane of the connection part 102.

On the other hand, the detection electrode 114 is formed on the X1 plane of the arm 105, the detection electrode 122 is formed on the X2 plane, and the Y1 plane which is the outer side surface of the vibrator 100 is formed on the X1 plane.
A temporary GND electrode 125 is formed, and a short-circuit electrode 129 that connects (short-circuits) the detection electrodes 114 and 122 on the X1 and X2 planes is formed. The arm 10
6, a temporary GND electrode 115 is formed on the X1 plane,
A temporary GND electrode 121 is formed on the surface, and the vibrator 100
The detection electrode 124 is formed on the Y2 surface, which is the outer side surface of the X-ray, and the provisional GND electrodes 115 and 12 on the X1 and X2 surfaces.
1 are connected to each other (short-circuit).

Next, a pad electrode 116 for extracting a detection signal is formed on the X1 surface of the connecting portion 102. The pad electrode 116 is connected to the X1 surface of the arm portion 105 via an extraction electrode 118. The arm portion 106 is connected to the formed detection electrode 114 and is connected to the arm portion 106 via the extraction electrode 126.
Is connected to the detection electrode 124 formed on the Y2 plane. A pad electrode 117 for grounding a temporary GND electrode is also formed on the X1 plane of the connecting portion 102. The pad electrode 117 is connected to the arm portion 1 via an extraction electrode 119.
The temporary GND electrode 115 formed on the X1 plane of No. 06 is connected. The temporary GND electrode 121 of the arm 106 connected to the temporary GND electrode 115 is connected to the connecting portion 1.
02 through the extraction electrode 123 formed on the X2 plane and the extraction electrode 127 formed on the Y1 plane of the arm 105.
Temporary GND electrode 12 formed on Y1 surface of arm 105
5 and the provisional GND electrodes 120 formed on the X2 plane of the arm portions 103 and 104 are connected to each other.

Then, as shown in FIG.
Reference numeral 1 denotes a drive electrode 1 formed on the X1 plane of the connecting portion 102.
12, four terminals T31 to T3 corresponding to the monitor electrode 113, the pad electrode 116, and the pad electrode 117.
4 and each of these electrodes and each terminal T3.
1 to T34 are connected by bonding wires W31 to W34, respectively. The vibrator 1
The procedure for forming the electrodes on each surface of 00 is exactly the same as that of the vibrator 2 shown in FIG.

When detecting the angular velocity using the angular velocity sensor having the above configuration, the driving arm 10
By applying a drive signal (AC voltage) between the drive electrode 112 formed on the third and fourth electrodes 104 and the provisional GND electrode 120, the inner tuning fork formed by the arms 103 and 104 is driven left and right. By controlling the drive signal using a control circuit (not shown) so as to resonate in the axial direction (Y-axis direction shown in the drawing) and to keep the output from the monitor electrode 113 constant, the tuning fork inside the vibrator 100 is formed. The part is self-oscillated. When the vibrator 100 is self-excited and oscillated in this manner, when an angular velocity Ω about the longitudinal central axis (Z axis) of the vibrator 100 is input,
The arms 103 and 104 also vibrate in the X-axis direction (detection axis direction) penetrating the X1 and X2 planes by Coriolis force. Then, each arm part 1 constituting the outer tuning fork part
05, 106 also vibrate in the X-axis direction, and the detection electrodes 114, 1
22 and the provisional GND electrode 125 and the detection electrode 12
4 and the temporary GND electrodes 115 and 121, a current proportional to the vibration in the X-axis direction flows. By converting the current between these electrodes into a voltage value, the angular velocity Ω around the Z-axis is changed. To detect.

When measuring the vibration characteristics of the vibrator 100 of this embodiment, the angular velocity sensor 1 is used in the same manner as in the above embodiment.
00 and a self-excited oscillation circuit 4 with an angular velocity detection circuit unit including a self-excited oscillation circuit 40, a detection circuit 50, and the like.
0, and using the detection signal obtained at that time and a reference signal that is input to the amplitude control circuit 42 and that represents the actual vibration state of the vibrator 2, monitors the in-phase signal components of these signals, In order to reduce the in-phase signal component (in other words, an unnecessary signal), each of the arm units 103 to
What is necessary is just to trim the ridgeline of the vibrator 100 near the base from which the 106 protrudes.

The ridge line to be trimmed may be the outer or inner side or the ridge line of the connecting portion 102 as long as it is the ridge line of each of the arm portions 203 to 206, as in the above-described embodiment. The vibrator 100 is connected to the connecting portion 1
The four arm portions 103 to 106 have a four-leg comb shape protruding in the same direction, have a greater number of vibration modes than the tuning-fork-shaped vibrator 2 described above, and have a drive shaft direction when detecting an angular velocity. In addition, since it is easily affected by another vibration mode different from the vibration in the detection axis direction, two edges are trimmed at the same time as an adjustment edge as shown in FIG. It is better to do it.

That is, FIG. 13A shows two ridge lines (P11) that are diagonally opposite to each other in one of the driving arms 103 and 104 on which the driving electrode 112 is formed. And P12, P13 and P14, P15 and P
16, P17 and P18) are set as one set, and the vibration characteristics of the vibrator 100 are adjusted by trimming any set of ridge lines at the same time.

According to such an adjustment method (in other words, the adjustment method according to the ninth aspect), the arm 103
Or 104, the adjustment portions of the vibrator 100 can be dispersed as compared with the case where one of the two ridge lines at the diagonal positions is trimmed, so that the vibration balance of the vibrator 100 is prevented from deteriorating. As a result, the influence of other vibration modes at the time of detecting the angular velocity can be reduced, and the vibration characteristics of the vibrator can be adjusted efficiently and with high accuracy. The arm 103 or 1
The reason why the two ridge lines at the diagonal positions are trimmed in 04 is that the ridge lines at the diagonal positions in one arm part have the vibration characteristics of the vibrator as described with reference to FIG. This is because they can be adjusted in the same direction.

On the other hand, FIG. 13B shows the driving arms 103 and 104 on which the driving electrodes 112 are formed.
An axis (in other words, the vibrator 10) at a central position between the arms 103 and 104 and parallel to the arms 103 and 104.
Two ridges (P21 and P22, P23 and P24, P25 and P26, P25
27 and P28) as one set, and the trimming of any set of ridge lines at the same time adjusts the vibration characteristics of the vibrator 100.

According to such an adjusting method (in other words, the adjusting method according to the tenth aspect), FIG.
The same effect as the adjustment method shown in FIG. 1 can be obtained, and since both of the pair of driving arms are shaved, the vibrator 100 can be obtained as compared with the case where only one arm 103 or 104 is trimmed. This can more reliably prevent the vibration balance from being deteriorated.

Next, the vibrator 200 of the angular velocity sensor shown in FIG.
Each of the tuning forks has an H-shape connected at a connecting portion 202 such that the reference numerals 3, 204 and 205, 206 face in opposite directions. The vibrator 200 is formed in an H-shape by machining PZT by dicing or the like, and the vibrator 200 is attached to the pair of arms 203 and 204 forming one tuning fork. An electrode for vibrating in the arrangement direction (Y-axis direction) is formed, and a pair of arms 205 and 206 constituting the other tuning fork are provided with the arms 203 to 206 applied to the vibrator 200.
An electrode for detecting the angular velocity around the z-axis parallel to the central axis of is formed.

That is, the drive electrode 207 and the monitor electrode 208 are formed on the X1 surface (one surface of the vibrator 200 having an H shape) of the arm portions 203 and 204. Then, the drive electrode 20 of each arm 203, 204
7 and the monitor electrode 208 are connected to each other at the connection portion 202. Further, temporary GND electrodes 210 and 211 are formed on the X1 surface of the arm portions 205 and 206, respectively.
The detection electrodes 212 and 21 are provided on the Y1 and Y2 planes (outer side surfaces of the vibrator 200 in the respective arm portions 205 and 206).
3 are formed.

The X2 plane of the vibrator 200 (vibrator 20
0), an arm 2
03 and 204 through the connecting portion 202 and the arm portion 20
Temporary GND electrodes 209 are formed over substantially the entire area extending to the arm portions 205 and 206. The temporary GND electrodes 210 and 211 formed on the X1 plane of the arm portions 205 and 206
Short-circuit electrodes 21 formed on the Y1 and Y2 planes 206
8, 219 are connected to the temporary GND electrode 209 on the X1 plane. Further, pad electrodes 214 and 215 for extracting a detection signal are formed on the X1 surface of the connection portion 202, and the detection electrodes 212 and 213 formed on the Y1 and Y2 surfaces of the arm portions 205 and 206 are connected to the extraction electrode 216. , 217 are connected to the pad electrodes 214, 215, respectively.

When detecting the angular velocity using the vibrator 200 having the above-described configuration, for example, the X
At the same time as fixing the two surfaces on the base via the supporter,
The temporary GND electrode 209 on the X2 plane is grounded to the reference potential. Then, the drive electrodes 2 formed on the arm portions 203 and 204 are formed.
07 and the provisional GND electrode 209, a drive signal (AC voltage) is applied between these arm portions 103, 1
The drive signal is generated by using a control circuit (not shown) so that the tuning fork formed by the drive circuit 04 resonates in the left and right drive axis directions (Y axis direction shown in the figure) and the output from the monitor electrode 208 becomes constant. By performing the control, the tuning fork inside the vibrator 200 is caused to self-oscillate.

When the angular velocity Ω around the Z-axis is input during the self-excited control oscillation of the vibrator 200, the arms 203 and 204 are moved by the Coriolis force to the X1 and X2 planes. Vibrates also in the X-axis direction (not shown) penetrating through. Then, each of the arm portions 2 constituting the other tuning fork portion
05 and 206 also vibrate in the X-axis direction.
2 and the provisional GND electrodes 209 and 210, and between the detection electrode 213 and the provisional GND electrodes 209 and 211, X
A current proportional to the axial vibration flows. Then, this current is taken out through the pad electrodes 214 and 215 and converted into a voltage value, thereby detecting the angular velocity Ω around the Z axis.

Also, when adjusting the vibrator 200 of this embodiment, similarly to the above embodiment, the angular velocity sensor 200 is provided with an angular velocity detection circuit unit including the self-excited oscillation circuit 40 and the detection circuit 50. The self-oscillation circuit 40 is operated, and a detection signal obtained at that time and a reference signal representing the actual vibration state of the vibrator 2 input to the amplitude control circuit 42 are used to generate in-phase signal components of these signals. So that the in-phase signal component (in other words, an unnecessary signal) is reduced, so that the ridge line of the vibrator 100 near the base from which each of the arms 203 to 206 protrudes from the connecting portion 202 is trimmed. I just need. Note that the ridgeline to be trimmed may be the outside or inside, or the ridgeline of the connecting portion 202, as long as it is the ridgeline of each of the arm portions 203 to 206.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration of an angular velocity sensor according to an embodiment including a tuning-fork-shaped vibrator.

FIG. 2 is an explanatory diagram showing electrodes formed on the vibrator shown in FIG.

FIG. 3 is an explanatory diagram illustrating a configuration of a self-excited oscillation circuit and a detection circuit connected to a vibrator and a system configuration at the time of adjusting vibration characteristics using these components.

FIG. 4 is an explanatory diagram for explaining a method of trimming a vibrator.

FIG. 5 is an explanatory diagram illustrating an adjustment procedure by trimming a vibrator.

FIG. 6 is an explanatory diagram showing a result of measuring a change in offset and offset temperature drift due to trimming of a vibrator.

FIG. 7 is an explanatory diagram showing a relationship between a trimming amount of a vibrator and a change in offset and offset temperature drift.

FIG. 8 is an explanatory diagram illustrating a measurement result obtained by measuring an optimum region when trimming an arm portion.

FIG. 9 is an explanatory diagram illustrating a measurement result obtained by measuring an optimum region when trimming a connecting portion.

FIG. 10 is an explanatory diagram illustrating a configuration of an angular velocity sensor including a comb-shaped vibrator having two sets of tuning forks.

FIG. 11 is an explanatory view showing electrodes formed on the comb-shaped vibrator shown in FIG.

FIG. 12 is an explanatory diagram illustrating a configuration of an H-shaped vibrator having two sets of tuning forks.

13 is an explanatory diagram illustrating an adjustment method by trimming the comb-shaped vibrator illustrated in FIG. 10;

[Explanation of symbols]

2,100,200 ... vibrator, 4,6,103-10
6, 203-206 ... arm part, 8, 102, 202 ...
Connecting parts, 12a, 12b, 112, 207 ... drive electrodes,
14a, 14b, 113, 208 ... monitor electrode, 16
a, 16b, 24, 115, 120, 121, 125,
209, 210, 211 ... temporary GND electrode, 18a, 18
b ... polarizing electrode, 20a, 20b, 116, 117, 2
14, 215: pad electrode, 22a, 22b, 114,
122, 124, 212, 213 detection electrodes, 26a,
26b, 28a, 28b, 128, 129, 218, 2
19 ... Short-circuiting electrodes 30a, 30b, 118, 11
9, 123, 126, 127, 216, 217 extraction electrodes, 32, 107 supporters 34, 110 spacers, 36, 111 base, 40 self-oscillation circuit 50
Detector circuit 60 Lock-in amplifier

Claims (11)

[Claims] 1. A piezoelectric body comprising at least a pair of arms formed in a prismatic shape and arranged in parallel with each other and a connecting portion connecting the arms, and an AC voltage is applied to an outer wall surface at least from the outside. And a drive electrode that excites each of the arm portions in a drive axis direction that is an arrangement direction of the arm portions, and a pair of detections that detect a vibration generated in a detection axis direction orthogonal to the drive shaft in each arm portion. electrode,
An angular velocity sensor provided with a vibrator formed with a vibrator, wherein irregularities for adjusting vibration characteristics are formed near the base of the vibrator where each of the arms protrudes from the connecting portion. Sensor. 2. The method according to claim 1, wherein the concave and convex portions have a height of 170 mm from a base of the vibrator in the arm portion with respect to a height of a connecting portion along a longitudinal direction of the arm portion.
% Of the connecting portion, a region within 70% of the height of the connecting portion along the longitudinal direction of the arm portion from the base of the vibrator, and / or a region of both of them. 2. The angular velocity sensor according to claim 1, wherein the angular velocity sensor is formed as follows. 3. The angular velocity sensor according to claim 2, wherein the unevenness is formed by cutting a part of the vibrator in the area. 4. The angular velocity sensor according to claim 3, wherein the unevenness is formed by cutting at least one ridge line of the vibrator along a longitudinal direction of the arm portion. 5. A piezoelectric body formed by at least a pair of arms formed in a prismatic shape and arranged in parallel with each other and a connecting portion connecting the arms, and an AC voltage is applied to the outer wall surface at least from the outside. And a drive electrode that excites each of the arm portions in a drive axis direction that is an arrangement direction of the arm portions, and a pair of detections that detect a vibration generated in a detection axis direction orthogonal to the drive shaft in each arm portion. electrode,
In an angular velocity sensor provided with a vibrator formed with, a method for adjusting vibration characteristics of the vibrator, wherein an AC voltage is applied to the drive electrode to vibrate the vibrator in a drive axis direction. As the unnecessary signal component of the detection signal obtained via the pair of detection electrodes is reduced,
A method of adjusting an angular velocity sensor, comprising forming irregularities near a root of the connecting portion from which the respective arm portions project from the connecting portion. 6. The method for adjusting the vibration characteristic, comprising: adjusting a height of a connecting portion along a longitudinal direction of the arm portion from a root of the vibrator in the arm portion;
% Of the connecting portion, a region within 70% of the height of the connecting portion along the longitudinal direction of the arm portion from the base of the vibrator, and / or a region of both of them. The method for adjusting an angular velocity sensor according to claim 5, wherein the method is performed by forming the unevenness on the angular velocity sensor. 7. The angular velocity sensor adjusting method according to claim 6, wherein the adjustment of the vibration characteristic is performed by cutting a part of the vibrator in the area. 8. The adjustment of the angular velocity sensor according to claim 7, wherein the adjustment of the vibration characteristic is performed by cutting at least one ridge line of the vibrator along a longitudinal direction of the arm portion. Method. 9. The method according to claim 9, wherein the adjustment of the vibration characteristic is performed by cutting two ridge lines at diagonal positions in at least one of the pair of arms on which the drive electrodes are formed. An adjustment method of the angular velocity sensor according to claim 8. 10. The adjustment of the vibration characteristic is performed in a pair of arms on which the drive electrodes are formed, at a central position between the arms and at a position symmetric about an axis parallel to the arms. The method for adjusting an angular velocity sensor according to claim 8, wherein the adjustment is performed by cutting two ridge lines. 11. The method of adjusting the vibration characteristic includes adjusting a length of the arm portion along a longitudinal direction when the ridge is cut, a depth of the vibrator when the ridge is cut, or both. The method for adjusting an angular velocity sensor according to any one of claims 7 to 10, wherein: