JPH11271066A - Angular velocity sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the oscillation leak from a driving beam to a detecting beam, and efficiently transmit the oscillation energy by the Coriolis force from the driving beam to the detecting beam to obtain a high-S/N sensor. SOLUTION: An oscillation member G comprises an approximately U-shaped driving oscillator having a pair of beams 2, 3 and coupling and an approximately U-shaped driving oscillator 5 which has a pair of beams 6, 7 and coupling 8 and is disposed analogously around the driving oscillator 1 having a driving electrode 20 for driving the beams 2, 3 in opposite phase in an x-axis direction, while the driving oscillator 1 has detecting electrodes 22-23 for detecting the oscillation of the beams 6, 7 in opposite phase in the x-axis direction upon input of an angular velocity around the x-axis. Both oscillators 1, 5 are coupled by a torsion beam 9 having a shape of a narrower width in the x-axis direction than that of the inner driving oscillator 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an angular velocity sensor having a vibrator for driving and detecting with separate beams.

[0002]

2. Description of the Related Art Conventionally, as an angular velocity sensor having a vibrator for performing driving and detection with separate beams, Japanese Patent Laid-Open No. 8-2781 is disclosed.
Japanese Unexamined Patent Application Publication No. 41 has proposed the above. This is the outer two beam portions of a comb-shaped composite tuning fork (a so-called four-legged vibrator) having four parallel beam portions (oscillating arms) and a support portion that supports one end of the beam portions in common. Are used as drive beams (drive-side tuning forks), and the two inner beams are used as detection beam portions (detection-side tuning forks) for driving / detection.

[0003] In the operation, first, the drive beam is excited in the opposite direction in the arrangement direction of the beam (drive vibration). When an angular velocity is input around a predetermined axis during the driving vibration, energy that the driving beam vibrates in a direction orthogonal to the excitation direction is transmitted from the support to the detection beam, and the detected energy is used to detect the energy. The angular velocity is detected by detecting the opposite-phase vibration (detection vibration) of the beam part. It is said that this four-legged vibrator has a high S / N (signal-to-noise ratio) compared to a two-legged vibrator (tuning fork) because the beam part is separated for driving and detection. .

[0004]

However, the present inventor has studied the above-mentioned prior art and found that there is a problem as described below, and a sufficient improvement in S / N cannot be obtained. In the four-legged vibrator, four beam portions (legs) are simply formed, and these beam portions are supported by the common supporting portion. Therefore, when the driving beam portion vibrates, the beam portion for detection is used. Also easily transmit vibration energy (so-called vibration leakage). Therefore, when you do not want to vibrate the detection beam,
That is, when the angular velocity is not input, a large unnecessary vibration of に 対 し of the drive amplitude is generated in the detection beam.

On the other hand, since the driving beam and the detecting beam are separated from each other, vibration energy due to the Coriolis force from the driving beam portion is required at the time of inputting the angular velocity (that is, at the time of inputting the Coriolis force) to obtain high sensitivity. It is necessary to efficiently transmit to the detection beam. In order to solve this problem, a study was conducted on a four-legged vibrator simply having three slits in the prior art described above. In this vibrator, the vibration energy due to the Coriolis force from the driving beam was efficiently transmitted to the detecting beam. Turned out not to be.

For example, the amplitude (ie, sensitivity) in the detection direction when Coriolis force is input to a vibrator (a two-leg tuning fork) composed of only a driving beam portion is the same as the driving beam portion of the four-legged vibrator. Comparing the amplitude of the detection beam in the detection direction when the Coriolis force is input, the latter is 1/1 of the former.
It was found that the sensitivity was reduced to 10, that is, the sensitivity was reduced to 1/10.

As described above, the influence of the driving vibration can be reduced to 1/5, but the sensitivity is reduced to 1/10.
The effect of driving vibration is greater than the conventional two-leg tuning fork,
There is a problem that a desired high S / N cannot be obtained. In view of the above, the present invention provides an angular velocity sensor including a vibrator that performs driving and detection with separate beams, and suppresses vibration leakage from the driving beam to the detecting beam, It is an object of the present invention to efficiently transmit vibration energy due to Coriolis force from the sensor to a detection beam portion and obtain a sensor with high S / N.

[0008]

SUMMARY OF THE INVENTION The present inventor has devised the shape and the like of a vibrator and a supporting portion for supporting the vibrator in an angular velocity sensor having a vibrator for performing driving and detection by separate beams. Thus, the above-mentioned object was achieved. According to the first aspect of the present invention, as shown in FIG. 1 and the like described later, two substantially U-shaped vibrators (1, 5) include
The main feature is the structure supported by connection.

That is, the angular velocity sensor of the present invention has an xy
In the z orthogonal coordinate system, a substantially U-shaped first vibrator (1) having a pair of first beams (2, 3) and a first connecting portion (4), and a pair of second beams A second vibrator (5) having a substantially U-shape having a portion (6, 7) and a second connecting portion (8) and arranged in a similar shape on the outer peripheral side of the first vibrator (1); Are connected by a torsion beam (9) having a shape in which the width in the y-axis direction at a position in contact with the first connection portion is smaller than the width in the y-axis direction of the first vibrator.

Here, one of the two vibrators (1, 5) is a driving vibrator (1) and the other is a detecting vibrator (5).
The driving vibrator includes driving means (20, 60, 61) for exciting the beam portions (2, 3) (that is, the driving beam portions) of the driving vibrator in the y-axis direction in the opposite phase to drive and vibrate. , 320, 42
0) is provided, and the beam (6, 7) (that is, the beam for detection) of the beam for detection, which is generated when an angular velocity around the z-axis is input, has an opposite phase in the x-axis direction. Angular velocity detecting means (22 to 24, 63, 64, 322, 323, 422) for detecting the angular velocity by detecting the vibration as a detection vibration
Is provided.

In the present invention, the driving beams (2, 3) are excited in the y-axis direction to drive and oscillate, but both of the first and second oscillators are used as the driving oscillators. Are narrower than the width of the first vibrator in the y-axis direction, so that the drive vibration in the y-axis direction is hardly transmitted. Therefore, vibration leakage from the driving beam portions (2, 3) to the detection beam portions (6, 7) can be suppressed.

The shape of the torsion beam (9) is
Since it has a narrow width in the y-axis direction, the torsion beam (9) is easily twisted around the z-axis. Therefore,
A driving beam (2, 2) generated when an angular velocity about the z-axis is input.
Vibration due to Coriolis force from 3) (vibration in x-axis direction)
Can be efficiently transmitted to the detection beams (6, 7) as torsional vibration around the z-axis.

As described above, in the present invention, vibration leakage from the driving beam to the detecting beam is suppressed, and vibration energy due to Coriolis force from the driving beam is efficiently transmitted to the detecting beam. And an angular velocity sensor realizing a high S / N can be provided. The invention described in claim 2 is the second invention in addition to the invention described in claim 1.
Torsion beams (10, 50, 51, 90).

That is, in the present invention, the first torsion beam (9) is used as the first torsion beam, and the first and second vibrators (1, 5) and the first torsion beam (9) are further provided. ) Are supported by the second torsion beams (10, 50, 51, 90) extending in the z-axis direction from either one of the connecting portions (4, 8). The width of the second torsion beam (10, 50, 51, 90) is equal to y at the point where the second torsion beam is in contact with the connecting portion.
The width of the first vibrator is smaller than the width of the first vibrator in the y-axis direction.

In the present invention, the function and effect of the torsion beam (9) according to the first aspect can be achieved by the first torsion beam (9), and the effect of the first aspect of the invention can be realized. Further, both oscillators and the first
Of the second torsion beam (10, 50, 51, 90) supporting the torsion beam of the first vibrator is also smaller than the width of the first vibrator in the y-axis direction. Is transmitted to both vibrators.
Therefore, in the driving and detecting vibrators, unnecessary vibration of each beam portion can be reduced.

Further, in the present invention, the width of the second torsion beam (10, 50, 51, 90) in the y-axis direction is made narrow like the first torsion beam (9). Causes the torsional vibration around the z-axis to be easily generated, and efficiently induces the vibration (vibration in the x-axis direction) due to the Coriolis force of both vibrators and the first torsion beam generated when the angular velocity is input around the z-axis. be able to.

Next, according to the third aspect of the present invention, as described in the second aspect, both torsion beams (9, 10, 5) are provided.
0, 51, 90), wherein the two torsion beams are arranged on the central axes of the two vibrators (1, 5). In the present invention, the central axes of both vibrators (1, 5) are z
Axis. That is, in the present invention, in the xyz rectangular coordinate system, a substantially U-shaped second beam having the first beam portions (2, 3) and the first connecting portion (4) arranged symmetrically with respect to the z-axis. A first vibrator (1) and a substantially U-shape having a second beam portion (6, 7) and a second connecting portion (8) arranged in a similar shape on the outer peripheral side of the first vibrator (1). A second vibrator (5) having a shape. In the present invention, the first vibrator has a shape in which the width in the y-axis direction is smaller than the width in the y-axis direction of the first vibrator.
And a second torsion beam (9, 10, 50, 51,
90) are arranged such that the respective central axes in the z-axis direction substantially coincide with the z-axis. That is, both torsion beams are located on the center axis (on the center line) of both transducers.
The above is the feature of the present invention.

According to the present invention, the same effects as those of the first and second aspects can be realized, and the first and second torsion beams (10, 50, 51, 90) can be realized.
Are arranged so as to be substantially coincident with the central axes of the two vibrators. Therefore, the vibration (x) caused by the Coriolis force from the driving beams (2, 3) generated when the angular velocity about the z-axis is input.
(Vibration in the axial direction) can be evenly distributed to the pair of detection beams (6, 7), and more efficient transmission can be performed.

The present inventor has noted that in the angular velocity sensor according to any one of claims 1 to 3, there are two vibration modes (detection resonance modes) for detecting an angular velocity when an angular velocity is input. Further studies were conducted to improve S / N. When the driving beams (2, 3) are driven and vibrated in a predetermined direction in opposite phases to each other (driving resonance mode), when an angular velocity is input, the driving beams are out of phase by a Coriolis force in a direction orthogonal to the driving vibration direction. Vibrates. The vibration due to the Coriolis force is transmitted to the detection beam portions (6, 7) by the first torsion beam (9) as described above, and the detection beam portions also vibrate in the opposite direction to the direction perpendicular to the driving vibration direction ( Detection vibration). That is, each of the four beams vibrates in synchronization with a direction orthogonal to the driving vibration direction. This vibration is the detection resonance mode.

Here, one detection resonance mode is:
A mode in which adjacent beam portions of the four beam portions vibrate in directions opposite to each other (see FIG. 8A described below, hereinafter referred to as a first detection resonance mode), and another detection resonance mode is In the case of four beams, two sets on one side and one set on the other side from the central axis of the vibrator, that is, the z-axis, are set as one set. Mode (see FIG. 8B described later, hereinafter referred to as a second mode).
This is called a detection resonance mode).

In each of these detection resonance modes, a desired detection resonance mode can be realized by appropriately setting the shape of the vibrator, for example, the width and length of the beam. As a result of examining a vibrator structure capable of improving S / N for each detection resonance mode, the amplitude XU of the pair of inner beams, that is, the first pair of beams (2, 3) and the pair of outer beams in each detection resonance mode are examined. The ratio XU of the beam portion, that is, the amplitude XS of the second beam portion (6, 7)
/ XS or XS / XU was found to be correlated with the sensitivity gain S.

The first resonance mode is selected according to each detection resonance mode.
If the ratio XU / XS is 10 or less in the second detection resonance mode, and the ratio XS / XU, which is the reverse ratio to the first detection resonance mode, is 10 or less in the second detection resonance mode, It has been found that a sensitivity gain S of an order of magnitude higher than that of the four-legged oscillator type can be realized. The invention according to claim 4 and claim 5 is characterized in that the ratio XU / XS or X
This is based on the knowledge of the correlation between S / XU and sensitivity gain S.

In other words, according to the fourth aspect of the present invention, at the time of inputting the angular velocity, adjacent beam portions among the beam portions (2, 3, 6, 7) vibrate in opposite directions in the x-axis direction, and The ratio XU / XS between the amplitude XU of the first beam portion and the amplitude XS of the second beam portion in the vibration in the x-axis direction is
The size of both vibrators and both torsion beams is set so as to be 10 or less.

In the present invention, the detection resonance mode for detecting the angular velocity uses the above-mentioned first detection resonance mode, in which the amplitude XU of the first beam portion (2, 3) and the second beam portion are used. The dimensions are set so that the ratio XU / XS of the amplitude XS of (6, 7) is 10 or less, so that the mechanical impedance can be reduced and the Coriolis force input to the driving beam (2, 3) Vibration can be efficiently transmitted to the detection beam portions (6, 7), sensitivity gain S can be improved, and S / N can be improved.

According to the fifth aspect of the present invention, when the angular velocity is input, two beams (6, 2) on one side of the z-axis and two beams on the other side of the z-axis of each of the beam portions (2, 3, 6, 7) are provided. (3, 7) is x
Vibrates in opposite directions in the axial direction, and the ratio XS / XU between the amplitude XU of the first beam portion and the amplitude XS of the second beam portion in the vibration in the x-axis direction becomes 10 or less. In which the dimensions of both transducers and both torsion beams are set.

In the present invention, the detection resonance mode for detecting the angular velocity uses the second detection resonance mode, and in that mode, the amplitude XU of the first beam portion (2, 3) and the second beam portion are used. The dimensions are set so that the ratio XS / XU to the amplitude XS of (6, 7) is 10 or less,
An effect equivalent to that of the described invention can be obtained. The invention according to claim 6 is characterized in that the first vibrator (1) has a first beam portion (2,
The ratio WS / WU between the interval WU of 3) and the interval WS of the second beams (6, 7) of the second vibrator (5) is set to 2.5 or less.

That is, the mechanical impedance of the vibrator can be reduced by bringing the WU and the WS closer to each other so that the rotational vibration efficiency (moment of inertia) of the first vibrator and the second vibrator are matched or close to each other. And the response due to the Coriolis force is improved, so that the second vibrator or the first vibrator is caused by rotational torsional vibration generated when Coriolis force is input to the first vibrator or the second vibrator. The torsional vibration of the vibrator can be easily generated, and the vibration energy due to the Coriolis force can be efficiently transmitted to obtain high sensitivity.

Further, according to the present invention, the ratio WU / WU of the distance WU between the first beam portions (2, 3) of the first vibrator (1) and the width HU of the first beam portion is provided. It is characterized in that the HU is 2.5 or more and 100 or less. That is, in order to increase the rotational torsional force (axial torque) to vibrate the second vibrator or the first vibrator on the detection side, the first vibrator or the second vibrator on the drive side The amplitude of the second vibrator or the first vibrator on the detection side at the time of Coriolis input is reduced by separating the point of force at which the Coriolis force of the vibrator acts from the substantially central axis of the pair of beams in both vibrators. Larger, that is, higher sensitivity can be obtained. If the ratio WU / HU is more than 100, the function as a tuning fork is reduced, and a sufficient drive amplitude cannot be obtained.

According to the present invention, the resonance frequency of the vibration mode in the y-axis direction is different between the first beam portion (2, 3) and the second beam portion (6, 7). By making the resonance frequencies of the first and second beams different from each other, the drive vibration (vibration in the y-axis direction) of the drive beams (2, 3) is reduced. Detection beam (6, 7)
If the beam is not vibrated even if it is partially transmitted,
Alternatively, since almost no vibration occurs, the influence of the driving vibration is further reduced, the noise N can be reduced, and the S / N
Can be improved.

The ninth aspect of the present invention is a device for controlling the ratio of the resonance frequency fd of the driving vibration of the driving beam portions (2, 3) to the resonance frequency fs of the detection vibration of the detecting beam portions (6, 7). fs
Is 0.8 ≦ fd / fs ≦ 0.99 or 1.01 ≦ fd
/Fs≦1.2, and by setting the ratio fd / fs within the above range, the coupling between the drive resonance mode and the detection resonance mode is suppressed, and the S / N is reduced. Can be improved.

Next, the invention according to claim 10 is characterized in that the two oscillators (1, 5) and the torsion beams (9, 10, 5) are used.
0, 51, and 90) are formed integrally from the piezoelectric body, and an angular velocity sensor having an inexpensive configuration can be provided. Next, the invention according to claim 11 is characterized in that the two oscillators (1, 5) and the torsion beam (9,
And 10) are formed separately and joined and connected. The torsion beam having the weakest impact resistance can be formed of a highly durable material (for example, metal or the like). Each of the torsion beams can be made as thin as possible in order to confine the vibration energy of the driving beam, and the vibration leakage can be more effectively suppressed, and an angular velocity sensor having high impact resistance and excellent reliability can be provided.

According to a twelfth aspect of the present invention, the second torsion beam (10, 50) extends from the second connecting portion (8) in the direction opposite to the second beam portion (6, 7). It is characterized by being formed, and provides one means of the configuration of the second torsion beam in the invention of claims 2 to 11. Claim 1
According to a third aspect of the present invention, the second torsion beam (51, 90) in the second to the eleventh aspects is arranged such that the second torsion beam (51, 90) extends from the first connecting portion (4) in the same direction as the first beam portion (2, 3). It is characterized in that it is formed so as to extend in the direction, and it is possible to easily maintain the center of gravity of the two vibrators (1, 5), to be strong against external vibration, and to be excellent in space efficiency. Can be something.

According to a fourteenth aspect of the present invention, the second torsion beams (50, 51) according to the second to eleventh aspects are arranged such that the second torsion beams (50, 51) extend from the second connecting part (8) to the second beam part (50). 6, 7) and in the same direction as the first beam portion (2, 3) from the first connecting portion (4) to the first beam portion (2, 3). It can be made strong against external impacts by supporting from the outside.

The invention according to claim 15 is the second invention.
And the first vibrator (1) and the second vibrator (5) outside the first vibrator are connected by a first torsion beam (9), and these are connected to a second torsion beam. In the configuration supported by (10), the following configuration is added. That is, the added configuration means that the second connecting portion (8) is in the z-axis direction opposite to the pair of second beam portions (6, 7) so as to sandwich the second torsion beam (10). , At least two frames (15a, 15b), a third connecting portion (16) connecting the two frames, and a third torsion beam (17) extending from the third connecting portion in the z-axis direction. )
And both oscillators and the first and second torsion beams are supported by the second and third torsion beams.

According to the present invention, when the driving and angular velocity detecting means (420, 422) separately provided for each transducer are connected to an external circuit, the second transducer on the outer peripheral side is connected to the inner peripheral section. Since the wiring space can be secured by using the frames (15a, 15b) provided in a portion different from the first vibrator and the first torsion beam on the side, the distance between both means can be increased, and both means can be separated. It is possible to reduce the influence of electrical noise and the like generated mutually between them.

According to the invention as set forth in claim 22, in the angular velocity sensor according to any of claims 1 to 21, the second connection is larger than the width (L1) of the first connection portion (4) in the z-axis direction. The width (L2) of the portion (8) in the z-axis direction is wider, and the amplitude XU of the first beam portion (2, 3) and the second
The ratio XU / XS or XS / XU to the amplitude XS of the beam portions (6, 7) can be appropriately reduced, and an angular velocity sensor having good sensitivity can be provided.

According to the twenty-third aspect of the present invention, in the angular velocity sensor of the first to twenty-second aspects, the width (W5) of the first torsion beam (9) in the y-axis direction and the second
The width (W5) of the torsion beam in the y-axis direction is set to not more than 3/5 of the width (W6) of the first connecting portion (4) in the y-axis direction. The effect of suppressing vibration leakage and efficiently transmitting vibration energy can be appropriately realized, and high S / N
Can be provided.

According to a twenty-fourth aspect of the present invention, the driving beams (2, 3) are provided with monitoring means (21, 62, 321, 421) for monitoring the driving vibration. Monitor means (21, 62, 321, 42
The driving beam portion is caused to self-excitedly vibrate based on the monitor signal from 1), and a stable driving vibration can be obtained with respect to a temperature change or the like.

The reference numerals in parentheses of the above-mentioned means indicate the correspondence with the concrete means described in the embodiments described later.

[0040]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. In each of the drawings described in the embodiments below, each electrode described below shows an external appearance, and for convenience, is hatched with diagonal lines, but does not show a cross section. (First Embodiment) The basic configuration of this embodiment is shown in FIG.
FIG. 1 is a perspective view of the angular velocity sensor according to the present embodiment. G is a vibrating member, which is roughly composed of a driving vibrator 1, a detecting vibrator 5, a first torsion beam 9, and a second torsion beam 10.

The driving vibrator (first vibrator) 1 has two rectangular pillar-shaped driving beams (first beams) 2, 3 arranged substantially in parallel. One end of each of the drive beam portions 2 and 3 is fixedly supported by a common connection portion (first connection portion) 4, and the drive vibrator 1 has a substantially U-shape. The detection vibrator (second vibrator) 5 includes two quadrangular prism-shaped detection beam portions (second beam portions) 6 and 7 arranged substantially in parallel. , 7 are fixedly supported at one end by a common connecting portion (second connecting portion) 8. The detection oscillator 5 has a substantially U-shape, and is arranged such that the U-shaped inner peripheral surface of the detection oscillator 5 faces the U-shaped outer peripheral surface of the drive oscillator 1. Have been.

In other words, the detecting vibrator 5 is arranged on the outer peripheral side of the driving vibrator 1 in a similar shape.
3, 6, 7 are parallel to each other, and each connecting portion 4, 8 is parallel to each other. Here, as shown in FIG.
Xyz with the longitudinal direction of 8, ie, the arrangement direction of each beam portion 2, 3, 6, 7 as the y-axis, the longitudinal direction of each of the beam portions as the z-axis, and the thickness direction of each of the beam portions and the two connecting portions as the x-axis. An orthogonal coordinate system is configured. Here, the z-axis is located at the center between the drive beam 2 and the drive beam 3 and at the center between the detection beam 6 and the detection beam 7. In other words, with respect to the z-axis,
The beams 2 and 6 and the beams 3 and 7 are arranged line-symmetrically, and the z-axis forms the central axis of both vibrators 1 and 5.

Hereinafter, description will be made based on the xyz rectangular coordinate system. Hereinafter, the x-axis direction refers to a direction parallel to the x-axis, and the same applies to the y-axis and the z-axis.
One end of the first torsion beam 9 has a first connecting portion 4.
The other end is fixed to the second connecting portion 8, and extends from the first connecting portion 4 in the opposite direction to the driving beams 2 and 3 to connect the two vibrators 1 and 5. I have. The second torsion beam 10 has one end fixed to the second connecting portion 8 and extends in the direction opposite to the first torsion beam, that is, in the direction opposite to the beams 2, 3, 6, and 7, and the other end. Is formed with a connecting portion 11 to be joined to a spacer 12 described later.

The width of the torsion beams 9 and 10 in the y-axis direction is smaller than the width of the driving vibrator 1 in the y-axis direction, and the center axis of each torsion beam 9 and 10 in the z-axis direction is the z-axis. It is arranged so as to substantially match with. In other words, the two torsion beams 9 and 10 are located substantially on the center line of the vibrator 1. The vibrating member G, that is, the two vibrators 1 and 5 and the two torsion beams 9 and 10 are made of, for example, a piezoelectric single crystal such as quartz, and have shapes formed by etching. In this example, the electrode is formed by etching using a Z _cut quartz plate and electrodes are arranged.

The connecting portion 11 is, as shown in FIG.
It is bonded and fixed to the substrate (base) 13 via the spacer 12 by adhesion or the like. The bonding between the spacer 12 and the substrate 13 is also performed by bonding or the like. Accordingly, the driving vibrator 1 is supported by the detecting vibrator 5 via the first torsion beam 9, the two vibrators 1, 5 and the first torsion beam 9 are supported by the second torsion beam 10, and the vibrating member G Is supported in a floating state via the connecting portion 11 and the spacer 12 so as to be able to freely vibrate with respect to the substrate 13. The connecting portion 11 is for ensuring the bonding with the spacer 12, and may not be provided, and the other end of the second torsion beam 10 may be directly bonded to the spacer 12.

Further, as will be described later, the dimensional relationship between the vibrating member and the torsion beam is determined by the ratio XU / XS between the amplitude XU of the first beams 2 and 3 and the amplitude XS of the second beams 6 and 7.
Is set to 10 or less, and the resonance frequencies of the vibration modes in the y-axis direction are set to the first beam portions 2 and 3 (fd) and the second beam portion 6,
7 (fd ₀ ), the resonance frequency fd of the driving vibration of the driving beam portions (first beam portion in this example) 2 and 3 and the detection beam portion (second beam in this example). The ratio is set so that the ratio fd / fs of the detection resonance frequency fs of the detection vibrations of the parts 6 and 7 falls within a predetermined range.

Here, an example of specific dimensions of each part of the vibration member G will be described with reference to the explanatory view of FIG. FIG. 2 shows the vibration member G from the x-axis direction. First, the dimension in the z-axis direction will be described. The length L1 of the driving beams 2 and 3 is 6
mm, the dimension L2 of the connecting portion 4 is 0.5 mm,
The length L3 of the first torsion beam is 1.0 mm. The length L4 of the detection beams 6, 7 is 6.5 mm,
The dimension L5 of the connecting portion 8 is 1.5 mm, and the length L6 of the second torsion beam is 1.0 mm.

Next, the dimension in the y-axis direction will be described. The dimension (width of the beam portion) W1 of each of the beam portions 2, 3, 6, and 7 is 0.25 mm. Regarding the interval (slit width) between adjacent beam portions, the interval W2 between the beam portion 6 and the beam portion 2, and
An interval W3 between the beam 3 and the beam 7 is 0.3 mm, and an interval W4 between the beam 2 and the beam 3 is 3.0 mm. The dimensions (W5) of both torsion beams 9, 10
Are both 0.4 mm. Further, in this example, the central axis interval WU of the beam portions 2 and 3 and the central axis interval WS of the beam portions 6 and 7 are set.
The ratio WS / WU is set to about 1.6. The dimensions (W5) of the torsion beams 9, 10 may be different from each other.

Thus, the two torsion beams 9, 10
Is smaller than the distance W4 between the beam 2 and the beam 3. That is, as described above, the torsion beam 8
Is narrower than the arrangement interval of the inner pair of beam portions 3 and 4. The dimension (thickness) t of the vibrating member G in the x-axis direction is uniform in each part in the present embodiment, and is, for example, 0.3 mm in the above specific example of dimensions.

Next, the electrode configuration of this embodiment will be described. Here, of the surfaces of the vibration member G that are orthogonal to the x-axis, a surface facing the substrate 13 is defined as an X2 surface, and a surface opposite to the X2 surface is defined as an X1 surface. In the present embodiment, both vibrators 1 and 5, both torsion beams 9 and 10, and connection portion 11 are respectively provided on the X1 plane and the X2 plane.
Constitute the same plane.

FIG. 3 shows the vibration member G in the z-axis direction (FIG. 1).
FIG. 9 is a view for explaining each side surface of each of the beam portions 2, 3, 6, and 7, as viewed from above). As shown in FIG. 3, the side surface orthogonal to the y-axis in each beam portion, the Y1 surface (outer peripheral side) in the beam portion 7, the Y3 surface (outer peripheral side), and the Y4 surface in the Y2 surface (inner peripheral side) (Inner peripheral side), Y5 plane (inner peripheral side) and Y6 plane (outer peripheral side) for beam part 2, Y7 plane (inner peripheral side) and Y8 plane (outer peripheral side) for beam part 6.

In this embodiment, X1, X2, Y1
The electrodes to be described later are formed on planes Y8 to Y8, and the electrode configuration is shown in the developed views of FIGS. In FIG. 4, (a) is the X1 plane, (b) is the Y1 plane, (c) is the Y8 plane,
(D) is a view from the Y2 plane, (e) is a view from the Y7 plane,
In FIG. 5, (a) is the X2 plane, (b) is the Y6 plane, (c)
Is the Y3 plane, (d) is the Y5 plane, and (e) is the Y4 plane.

Reference numeral 320 denotes a driving electrode (driving means). In the driving vibrator 1, surfaces Y5 and Y6 of the beam 2 and the beam 3
Drive electrodes 32 formed on the X1, X2, Y3, and Y4 surfaces of the connection portion 4 and the X1 and X2 surfaces of the connection portion 4, respectively.
All 0s are conducting. Then, the drive electrode 320
In the X2 plane, the connection part 4 is drawn out to the connection part 11 through the torsion beam 9, the connection part 8, and the torsion beam 10, and is led to the pad electrode 320a formed in the connection part 11 in the X1 plane to conduct.

Reference numeral 321 denotes a monitor electrode (monitor means). In the driving vibrator 1, X1, X2, Y
5, Y6 surface, the Y3 and Y4 surfaces of the beam portion 3, and the X2 surface of the connecting portion 4, and the monitor electrode 3 formed on each surface.
21 are all conducting. Then, the monitor electrode 321
Is connected through the torsion beam 9, the connecting portion 8, and the torsion beam 10 from the connecting portion 4 on the X2 plane.
1 and is led to the pad electrode 321a formed on the connection portion 11 on the X1 plane to conduct.

Reference numerals 322 and 323 denote angular velocity detecting electrodes (angular velocity detecting means) for detecting angular velocity. The angular velocity detection electrode 322 is connected to the X1 and X
2, Y7, Y8 surface, X1, X2, Y1, Y2 of beam 7
Surface and the X1 surface of the connecting portion 8, and the angular velocity detection electrodes 322 formed on each surface are all conductive.
Then, the angular velocity detection electrode 322 is drawn out from the connecting portion 8 through the torsion beam 10 to the connecting portion 11 on the X1 plane, and is electrically connected to the pad electrode 322a formed on the connecting portion 11 on the X1 plane.

The angular velocity detecting electrode 323 is connected to the detecting vibrator 5.
, The X1, Y7, and Y8 surfaces of the beam 6 and the X of the beam 7
The angular velocity detecting electrodes 323 formed on the surfaces Y1, Y1, Y2 and X1 of the connecting portion 8 are all conductive. The angular velocity detection electrode 323 is drawn out of the connecting portion 8 through the torsion beam 10 to the connecting portion 11 on the X1 plane, and is electrically connected to the pad electrode 323a formed on the connecting portion 11 on the X1 plane.

Further, as shown in FIG. 1, the substrate 13 is provided with terminals (lead terminals) T11 to T14 connected to a control circuit (control means) C10 described later. The terminal T11 is connected to the wire W11 and the pad electrode 3
The terminal T12 is connected to the monitor electrode 321 via the wire W12 and the pad electrode 321a, and the terminal T13 is connected to the monitor electrode 321 via the wire W13 and the pad electrode 322a.
The terminal T14 is connected to the angular velocity detection electrode 323 via the wire W14 and the pad electrode 323a. The connection of the respective wires is performed by, for example, wire bonding.

Next, the control circuit C10 provided in the angular velocity sensor of this embodiment will be described with reference to the block diagram shown in FIG. The control circuit C10 broadly detects the driving system C11 that drives and vibrates the driving beams 2 and 3 by self-excited oscillation (self-excited vibration), and detects the detection vibration of the detection beams 6 and 7 to detect the angular velocity. It is divided into a detection system C12.

The drive system C11 is a charge amplifier 100 that converts the output (current) from the monitor electrode 321 into a voltage.
And an AGC (auto gain control) circuit 101 provided after the charge amplifier 100. The AGC circuit 101 applies the constant voltage to the drive electrode 320 while maintaining the feedback signal from the charge amplifier 100 to be a constant voltage.

The detection system C12 includes an angular velocity detection electrode 322,
Current-voltage conversion circuits 202a and 202b for converting an output (current) from the H.323 into a voltage, and a current-voltage conversion circuit 2
Circuit 2 for subtracting the outputs from the circuits 02a and 202b
3, a synchronous detection circuit 103 provided after the differential circuit 203, an LPF (low-pass filter) 104, and a phase shift circuit 105 that shifts the feedback signal from the charge amplifier 100 by 90 °.

The current-voltage conversion circuits 202a, 202a,
02b is subtracted by a differential circuit 203, subsequently synchronously detected by a synchronous detection circuit 103 based on the feedback signal (monitor signal) shifted by the phase shift circuit 105, and then outputted by an LPF 104. , Are converted to a DC voltage and output as an angular velocity signal.

Next, the operation of this embodiment will be described (see FIGS. 7 and 8A). First, by applying an AC voltage to the driving electrode 320 formed on the driving vibrator 1, the driving beams 2, 3 are mutually centered in the y-axis direction of the vibrator 1 as shown in FIG. It resonates in a mode (drive resonance mode) in which bending vibration is performed so as to open and close symmetrically with respect to the line (z axis) (that is, in a phase opposite to each other).

The current proportional to the amplitude in the drive resonance mode is converted into a voltage by the charge amplifier 100 as an output from the monitor electrode 321 and monitored by the AGC circuit 101 so that this voltage, that is, the monitor signal is always constant. , A signal of a constant voltage (drive signal) is applied to the drive electrode 320. Self-excited oscillation is performed in the closed system described above, and drive vibration is performed in the drive beams 2 and 3.

At this time, since the vibration energy of the driving vibrator 1 is confined, the detecting beams 6 and 7 of the detecting vibrator 5 hardly vibrate. Therefore, the output from the angular velocity detecting electrodes 322 and 323, that is, the noise N is extremely small. This is because the torsion beam 9 connecting the driving vibrator 1 and the detecting vibrator 5 has a width smaller than the width of each of the vibrators 1 and 5, so that the drive resonance of the driving vibrator 1 is suppressed. The vibration in the y-axis direction such as the mode
Because it is not transmitted. The resonance frequency of the drive resonance mode (drive vibration) and the detection beam portions 6 and 7 are y.
This is because the dimensions and shape are set so as to differ from the resonance frequency of the mode of bending vibration in the axial direction.

Next, when an angular velocity is input around the z-axis during the driving vibration, Coriolis force is generated in the vibrating beam portions 2 and 3 of the driving vibrator 1, and the detecting vibrator 5 is driven. Are subjected to forces in mutually opposite directions in the x-axis direction orthogonal to the excitation direction. At this time, since the torsion beam 9 connecting the driving oscillator 1 and the detecting oscillator 5 transmits torsional vibration around the z-axis, the detecting oscillator 5 also undergoes torsional rotational vibration, and the detecting beams 6 and 7. Also vibrate in opposite directions in the x-axis direction. That is, as shown in FIG.
This is the first detection resonance mode described in the section of the means.

In the first detection resonance mode, an amplitude in the x-axis direction, that is, a current proportional to the angular velocity is generated from the angular velocity detection electrodes 322 and 323. The current is
The current is converted into a voltage by the current-voltage conversion circuits 202a and 202b. Here, since the outputs from the angular velocity detection electrodes 322 and 323 are generated in phases opposite to each other,
A subtraction process is performed in the differential circuit 203, a detection process is performed in the synchronous detection circuit 103 based on a feedback signal (monitor signal) from the phase shift circuit 105, and a signal smoothed through the LPF 104 is set as a final output. This final output produces a DC output (angular velocity signal) proportional to the angular velocity.

In the present embodiment, the width (W5 in FIG. 2) of the first torsion beam 9 connecting the two oscillators 1 and 5 in the y-axis direction is equal to the driving oscillator (first oscillator). 1 is smaller than the width in the y-axis direction, in particular, in the illustrated example, smaller than the width W4 between the driving beams 2 and 3. Therefore, since the driving vibration of the driving beams 2 and 3 in the y-axis direction is attenuated by the first torsion beam 9, the detection beams 6 and
7, and vibration leakage can be suppressed.

Also, according to the present embodiment, both vibrators 1,
5 and the second torsion beam 10 supporting the first torsion beam 9 also have a width in the y-axis direction (W5 in FIG. 2).
However, since the width is smaller than the width W4 between the driving beams 2 and 3, unnecessary vibration from the outside or the like can be suppressed from being transmitted from the substrate 13 or the like to the two vibrators 1 and 5. Therefore, unnecessary vibrations can be reduced in both vibrators 1 and 5.

According to the present embodiment, the first and second
The torsion beams 9 and 10 have a narrow width in the y-axis direction as described above and are arranged so that the axis in the z-axis direction substantially coincides with the z-axis. Only torsional vibration around the axis can be easily transmitted. Therefore, the energy of the vibration (vibration in the x-axis direction) due to the Coriolis force from the driving beams 2 and 3 generated at the time of inputting the angular velocity about the z-axis is efficiently transmitted to the detection beams 6 and 7 as torsional vibration. can do.

Next, the unique features of this embodiment will be described.
The following description focuses on the differences from the above conventional technology. Further, the present embodiment is characterized in that the two tuning-fork type vibrators 1 and 5 are connected via the torsion beam 9. By the way, in the above-mentioned conventional technology, the four beam portions are connected to one common connecting portion. And has a transmission characteristic with many degrees of freedom. That is, not only the mode desired to be transmitted from the driving beam to the detection beam, but also other unnecessary modes are transmitted. On the other hand, in the present embodiment, the S / N can be improved by applying the characteristic of the torsion beam that easily transmits only the twist required for the angular velocity detection.

For example, in the above prior art, the vibration energy of the driving beam is transmitted to the detecting beam via the connecting portion, and vibrates even though the angular velocity is not input.
That is, noise is generated. On the other hand, in the present embodiment, the first torsion beam 9 mainly transmits only torsional vibration.
Vibrates around the z-axis, and only when torsional vibration occurs in the first torsion beam 9, vibration energy is transmitted to the detection beams 6 and 7. In other words, there is a structurally essential difference in that the detection beams 6, 7 vibrate only when the angular velocity is input, and hardly vibrate in other cases, that is, hardly generate noise.

The inventor of the present invention has conducted intensive studies on the vibration transmission of the two tuning-fork vibrators 1 and 5 and found that the connection by the torsion beam is optimal for the angular velocity sensor. In the present embodiment, this research was embodied. An object of the present invention is to provide an angular velocity sensor excellent in S / N by a composite tuning fork. In this embodiment, the first detection resonance mode (see FIG. 8A) is used as the detection resonance mode for detecting the angular velocity, and the amplitude of the inner driving vibrator 1 in the vibration mode is used. XU and outer detecting transducer 5
The characteristic is that the dimension (see FIG. 2) of the vibrating member G is formed such that the ratio XU / XS to the amplitude XS is 10 or less, which is a point for improving the S / N.

The above prior art, that is, Japanese Patent Application Laid-Open No. 8-27814
The XU / XS of the vibrator described in the embodiment described in Japanese Patent Publication No. 1 is as large as 10.7 or more in the detection resonance mode. In the case of such a shape, when Coriolis force is input to the driving vibrator, the amplitude in the direction orthogonal to the arrangement direction of the legs is very small, and accordingly, the amplitude of the detecting vibrator also becomes small. The same applies to the case where the outside is driven and the inside is detected, or vice versa.

In this case, the amplitude (ie, sensitivity) at the time of Coriolis input can be obtained only 1/10 or less of the conventional two-leg tuning fork. Also, regarding the effect of separating the driving and detecting transducers, the noise reduction effect is 1/5 that of a two-leg tuning fork.
Combined with the decrease in sensitivity, the structure described in the related art shows S
/ N improvement is not enough. Further, for example, since the sensitivity S decreases, the sensitivity to external G becomes weaker by the decrease in the sensitivity S,
For example, it becomes difficult when the vehicle is considered.

The present embodiment has been made as a result of studying the structure of the vibrator for the above-mentioned problems of noise and sensitivity. The driving and detecting vibrators 1 and 5 have high vibration stability. Tuning forks are adopted, and these are connected to each other by a torsion beam 9 to form a composite tuning fork structure. Thereby,
From the viewpoint of noise, since the torsion beam 9 transmits only torsional vibration, the angular velocity is input, and the driving vibrator 1 rotates and vibrates around the z-axis. Vibration energy is transmitted.

In other words, the present embodiment proposes a structure in which the detection beams 6, 7 vibrate only when an angular velocity is input, and do not vibrate otherwise, that is, generate no noise. Thereby, the amplitude ratio between the driving oscillator 1 and the detecting oscillator 5 in the driving resonance mode can be reduced from tens of thousands to hundreds of thousands, that is, noise is reduced from tens of thousands to several tens of thousands. The vibration member G described as an example of the specific dimensions described above with reference to FIG.
It is possible to reduce it by a factor of 10,000.

As a result of examining the structure of the vibrator also with respect to the problem of the sensitivity S, it has been clarified that the amplitude ratio XU / XS is important for achieving high sensitivity. As the ratio XU / XS is reduced, the detecting vibrator 5
Vibration energy is also distributed, and the amplitude of the detection vibrator 5 in the detection direction (x-axis direction) increases when Coriolis force is input, that is, the sensitivity S increases, and the S / N of the sensor is improved.

The relationship between the ratio XU / XS and the amplitude XS (that is, sensitivity S) of the beam portions 6 and 7 of the outer detecting vibrator 5 is shown.
This relationship is detected by the amplitude XS of the beam portions 6 and 7 in the specific example of the dimensions described in FIG. 2 and the detection in the two-leg tuning fork M having the dimensions and shape shown in FIG. FIG. 10 shows the ratio of the sensitivity to the amplitude (ie, sensitivity) of the vibration. Here, the thickness of the vibration member G was 0.3 mm.

Further, from the viewpoint of reducing the mechanical impedance of the vibrating member G, which is a composite tuning fork, improving the response to Coriolis force and improving the sensitivity, the distance between the beams 2 and 3 of the inner driving vibrator 1 is improved. (W4 in FIG. 2, slit width) was used as a parameter for the study. For example, the study was conducted by changing the parameter W4 in the range of 0.3 to 5 mm.

FIG. 10 shows the ratio between the ratio XU / XS in the first detection resonance mode on the horizontal axis and the inner driving vibrator (first
When the dynamic load corresponding to the same value of Coriolis force is applied to the beams 2 and 3 of the vibrator 1 and the beam of the two-leg tuning fork M, the amplitude of the beams 6 and 7 of the outer vibrator 5 for detection. XS and bipod tuning fork M
, The sensitivity of the two-leg tuning fork M, ie, the sensitivity, is 1.

As can be seen from FIG. 10, when the ratio XU / XS is reduced, the sensitivity increases. Thereby, by reducing the ratio XU / XS,
In the composite tuning fork according to the present embodiment, the driving vibrator 1
It was found that the vibration energy due to the Coriolis force was dispersed in the detecting vibrator 5 and the sensitivity could be increased. Also,
Looking at the product of the ratio XU / XS and the sensitivity ratio, the amplitude XU of the inner driving vibrator (first vibrator) 1 is also large. It was found that the vibration energy of the vibrator became large, that is, the mechanical impedance of the vibrator could be reduced.

From the above, it can be understood that the mechanical impedance of the vibrator can be reduced by reducing the ratio XU / XS, and a vibrator with high sensitivity can be obtained. It must be: Specifically, as a method of reducing the ratio XU / XS, in the vibrating member G, the beam portion 6 of the outer second vibrator (in this example, the vibrator for detection) 5 and the interval WS (see FIG. 2) ) And the ratio WS / WU between the beam portion 2 and the interval WU (see FIG. 2) of the inner first vibrator (the driving vibrator in this example) 1 are effective. I understand.

In order to reduce the ratio XU / XS, that is, to make the amplitude of the inner first vibrator and the outer second vibrator the same in the x-axis direction, the rotational vibration of the two vibrators From the idea of matching ease (that is, matching the moment of inertia of both), adjust the length of each rotating arm,
That is, it is necessary to reduce the interval ratio WS / WU, and the relationship between the interval ratio WS / WU and the amplitude ratio XU / XS has been studied. As a result, to realize a more sensitive oscillator,
It has been found that it is desirable to set the interval ratio WS / WU to 2.5 or more.

Similarly, from the viewpoint of adjusting the easiness of the rotational vibration of the two vibrators, the outer second vibrator 5 is connected to the second torsion beam 1 like the present embodiment.
It is preferred to support through 0. Further, in the vibrating member G, when the Coriolis force is input to the driving vibrator 1, in order to increase the torsional rotational force, that is, the torque, to the detecting vibrator 5, the distance between the driving beams 2 and 3 is increased. W
It is desirable to increase U (see FIG. 2), and the width HU of the driving beams 2, 3 of the width W1 of each beam (see FIG. 2).
On the other hand, it is desirable that the ratio WU / HU be 2.5 or more.

Incidentally, in the embodiment described in the above prior art, the ratio WS / WU is 2.82 and no torsion beam is provided, so that the moment of inertia is large and the ratio XU is large.
/ XS is about 10.7, and high sensitivity cannot be obtained. On the other hand, in the present embodiment having the torsion beams 9 and 10, when the interval ratio WS / WU is 1.34, the amplitude ratio XU / XS becomes as small as 1.33, and the Coriolis force input is reduced. As for the amplitude of the detecting vibrator 5 in the detecting direction, the sensitivity was 1.3 times higher than that of the conventional two-leg tuning fork, and the sensitivity was at least one order of magnitude higher than that of the prior art. That is, it was confirmed that the structure of the present embodiment is a structure capable of transmitting vibration energy to the detection beams 6 and 7 at a high rate and obtaining a gain. The reference dimensions for realizing this are the same as the specific dimensions described above with reference to FIG.

In the present embodiment, the effect of supporting the vibrator by the torsion beam is not only the effect of improving the sensitivity described above, but also the effect of stably realizing the detection resonance mode. Have. Other than the torsion beam, for example, it is described that a lower portion of the vibrator is fixed to a rigid body, and a part of the above-described prior art example is provided with a cylindrical support hole in a thickness direction of the vibrator.

However, in the latter case, when a cylindrical pin is joined to this hole and the vibrator is supported from the side, the detection resonance mode described in the above prior art occurs, but it is proposed in the present invention. Detection resonance mode does not occur,
I cannot get stable. If it is further added, in the above-mentioned conventional technology, the method of supporting the vibrator is not specified, and the method of supporting the vibrator is an important element at the same level as the structure of the vibrator. Should be composed. The present embodiment provides a structure in which the method of supporting the vibrator and the structure of the vibrator are integrated.

In this embodiment, as shown in FIG. 2, the widths W1 of the drive beams 2, 3 and the detection beams 6, 7 are the same, and the length of the drive beams 2, 3 is long. The length L1 and the length L4 of the detection beam portions 6 and 7 are different. Therefore, in the driving resonance mode (vibration in the y-axis direction), the resonance frequencies of the bending modes are made different from each other, and the driving beam 3,
Even if the driving vibration of 4 is transmitted, the bending vibration of the detection beams 2 and 5 is attenuated, and the S / N can be improved.

In the present embodiment, the ratio fd / fs of the resonance frequency of the drive vibration (drive resonance frequency) fd to the resonance frequency of the detection vibration (detection resonance frequency) fs is, for example, 1.
Since the dimensions are set to be 04, the coupling between the drive resonance mode and the detection resonance mode can be suppressed, and the S / N can be improved. According to the study of the present inventor, in order to suppress the coupling between the two modes, the ratio fd / fs
Is 0.8 ≦ fd / fs ≦ 0.99 or 1.01 ≦ fd
/Fs≦1.2 is preferable.

As described above, in the present embodiment, the operation of each torsion beam 9, 10, the difference in the resonance frequency in the drive resonance mode of both oscillators 1, 5, the optimization of the ratio fd / fs, and the amplitude ratio XU By virtue of each effect of the dimension setting of the vibration member G such that / XS ≦ 20, vibration leakage from the driving beam to the detection beam is suppressed, and vibration energy due to Coriolis force from the driving beam is reduced. It is possible to provide an angular velocity sensor that can efficiently transmit the beam to the detection beam and realizes a high S / N.

Incidentally, if this embodiment is additionally described, the two vibrators 1 and 5 are made of another piezoelectric material, for example, PZ
It may be formed by dancing T, lithium niobate or langasite. Further, the present invention can be applied to a vibrator using a semiconductor. The thickness of the vibrator is not particularly limited, but the width of the beam portion is assumed to be 0.01 mm to 5 mm based on physique restrictions, driving frequency, and common sense from the viewpoint of manufacturing. From the relationship between fs and the detected resonance frequency fd, it is assumed that the thickness is half to twice the thickness, that is, 0.005 mm to 10 mm. (Second Embodiment) The basic configuration of the second embodiment is shown in FIG. FIG. 12 is a perspective view of the angular velocity sensor of the present embodiment. Also in the present embodiment, the vibration member G is mainly composed of the driving vibrator 1, the detecting vibrator 5, the first torsion beam 9, and the second torsion beam 10. Hereinafter, points different from the first embodiment will be mainly described, and the same portions will be denoted by the same reference numerals in the drawings to simplify the description.

The driving vibrator (first vibrator) 1 includes two driving beams (first beams) 2 and 3 and a connecting portion (first beam).
And a substantially U-shape. The detecting vibrator (second vibrator) 5 includes two detecting beam portions (second beam portions) 6, 7 and a connecting portion (second connecting portion) 8,
It has a substantially U shape, and is arranged such that the U-shaped inner peripheral surface of the detection transducer 5 faces the U-shaped outer peripheral surface of the driving transducer 1.

Here, also in FIG. 12, an xyz rectangular coordinate system is constructed in the same manner as in the first embodiment. Hereinafter, description will be made based on this xyz rectangular coordinate system. The first torsion beam 9 is fixed to the first and second connecting portions 4 and 8, respectively, and connects the two oscillators 1 and 5, and the second torsion beam 10 is fixed to the second connecting portion 8 and the substrate 13. Is fixed to the spacer 12. The vibration member G as a whole is connected to the substrate 1 via the connection portion 11 and the spacer 12.
3 is supported in a floating state so as to be able to freely vibrate.

As in the first embodiment, the width of the torsion beams 9 and 10 in the y-axis direction is
Is smaller than the width in the y-axis direction, and the center axes of the torsion beams 9 and 10 in the z-axis direction are arranged so as to substantially coincide with the z-axis. Here, in the present embodiment,
The vibration member G is integrally formed by machining a piezoelectric material such as PZT (lead zirconate titanate) by dicing or the like, and each of the beam portions 2, 3, 6, and 7 is formed as shown in FIG.
As shown by a white arrow in FIG. 2, polarization is performed in the x-axis direction.

As shown in FIG. 12, the connecting portion 11 is joined and fixed to the substrate 13 via the spacer 12 by welding or the like. The connection between the spacer 12 and the substrate 13 is also performed by welding or the like. Further, as in the first embodiment, the dimensional relationship of the vibration member G is determined by the amplitude ratio X.
U / XS is set to 10 or less, and the resonance frequency of the vibration mode in the y-axis direction is different between the first beam portions 2 and 3 (fd) and the second beam portions 6 and 7 (fd ₀ ). It is set so as to satisfy the constraint conditions such as, for example, that the ratio fd / fs of the resonance frequency of the drive and the detected vibration is within a predetermined range.

Here, an example of specific dimensions of each part of the vibration member G of the present embodiment will be described with reference to the explanatory view of FIG. FIG. 13 shows the vibrating member G viewed from the x-axis direction, and each of the dimension codes L1 to L6, W1 to W5, WS and WU refers to the dimensions at the same parts as in the first embodiment. In the dimension in the z-axis direction, the length L1 of the driving beams 2 and 3 is 9 mm, the dimension L2 of the connecting portion 4 is 2 mm, the length L3 of the first torsion beam 9 is 1 mm, and the length of the detecting beams 6 and 7 is The length L4 is 11 mm, and the dimension L5 of the connecting portion 8 is 2
mm, the length L6 of the second torsion beam 10 is 1 mm
It is.

In the dimension in the y-axis direction, each of the beams 2, 3,.
The width W1 of each of 6 and 7 is 1.2 mm and the slit width W
2 and W3 are both 0.4 mm, and slit width W4 is 4.0 m.
m. Therefore, the total length of the vibrator 1 is 9.6 mm. The dimension W5 of the torsion beams 9, 10 is 1.
4 mm, the ratio WS / WU of the center axis interval WU of the beam portions 2 and 3 and the center axis interval WS of the beam portions 6 and 7 is set to about 1.6.

Thus, the two torsion beams 9, 10
Is smaller than the distance W4 between the pair of inner beam portions 2 and 3 in the y-axis direction. In the present embodiment, the dimension (thickness) t of the vibration member G in the x-axis direction is uniform in each portion.
For example, in the above example of specific dimensions, it is 1.5 mm.
Next, the electrode configuration of the present embodiment will be described. Here, of the surfaces of the vibration member G that are orthogonal to the x-axis, a surface facing the substrate 13 is defined as an X2 surface, and a surface opposite to the X2 surface is defined as an X1 surface. In the vibrating member G, the surface orthogonal to the y-axis and on the outer peripheral surface side of the detection beam portions 6 and 7 is the same as the beam portion 6 as the Y2 surface, and the same surface as the beam portion 7 is the Y surface.
One side. In the present embodiment, also, in each of the X1 plane and the X2 plane, the two vibrators 1 and 5, the two torsion beams 9, 10 and the connection part 11 form the same plane.

In this embodiment, X1, X2, Y
Each electrode described later is formed on the Y1 and Y2 planes, and the electrode configuration is shown in a developed view of FIG. In FIG. 14, (a) is the X1 plane, (b) is the X2 plane, (c) is the Y1 plane,
(D) shows an electrode configuration on the Y2 plane. Hereinafter, description will be made with reference to FIG. Reference numeral 20 denotes a drive electrode (drive means), and X
On one surface, it is formed continuously from the outer peripheral side of the beam portion 3 to the outer peripheral side of the beam portion 2 through the connecting portion 4. Reference numeral 21 denotes a monitor electrode (monitor means).
Are formed continuously from the inner peripheral side through the connecting portion 4 to the inner peripheral side of the beam portion 2.

Reference numerals 22, 23 and 24 are angular velocity detecting electrodes (angular velocity detecting means) for detecting angular velocity. The angular velocity detection electrode 22 is formed over substantially the entire area of the beam 7 on the Y1 plane. On the other hand, the angular velocity detecting electrode 23 is formed over substantially the entire area of the beam 6 on the X1 plane, and the angular velocity detecting electrode 24 is formed substantially over the entire area of the beam 6 on the X2 plane. And
As shown in FIG. 14, all of the angular velocity detection electrodes 22 to 24 are extraction electrodes 25, 26, and 27 formed on each surface.
Connected and conducting. The angular velocity detection electrodes 22 and 23 are connected via an extraction electrode 25 (on the Y1 plane) and an extraction electrode 26 (on the X1 plane).
3 and 24 are connected via an extraction electrode 27 (on the Y2 plane).

28, 29, 30, and 31 correspond to the driving
This is a common electrode serving as a reference potential for the monitor and the angular velocity detection electrodes 20 to 24. The common electrode 28 is provided on substantially the entire area of the beam portion 7 on the X1 plane, and the common electrode 29 is provided on the vibrator 1 on the X2 plane.
Are formed continuously over substantially the entire area. Further, the common electrode 30 extends from substantially the entire area of the beam portion 7 on the X2 plane to the connecting portion 8.
Are formed continuously over substantially the entire area of the common electrode 3.
1 is formed over substantially the entire area of the beam portion 6 on the Y2 plane.

Then, all the common electrodes 28 to 31 are
As shown in FIG. 14, the extraction electrodes 3 formed on each surface
2, 33, 34 and 35 are electrically connected. The common electrodes 28 and 30 are connected to an extraction electrode 32 (Y1
Surface), the common electrodes 29 and 30 are connected to the extraction electrode 3
3 (the nine first torsion beams on the X2 plane), the common electrodes 30 and 31 are connected to the extraction electrode 34 (X2 plane).
Surface) and the extraction electrode 35 (Y2 surface).

In the X1 plane, pad electrodes 36 and 37 for wire bonding described later are formed on the connecting portion 8. The pad electrode 36 is an angular velocity detecting electrode 2
The pad electrode 37 is located at the end of the extraction electrode 38 extending from the common electrode 28, and is formed wider than the extraction electrodes 26 and 38, respectively, in the middle of the extraction electrode 26 that conducts with the electrodes 2 to 24. Accordingly, the pad electrode 36 is electrically connected to the angular velocity detection electrodes 22 to 24, and the pad electrode 37 is electrically connected to the common electrodes 28 to 31.

The surface of the vibrator 1 orthogonal to the y-axis direction is the surface facing the beam 6 and the beam 2, and the beam 2 and the beam 3
No electrode is formed on the opposite surface of the beam portion 3 and the opposite portion of the beam portion 7. Further, the drive electrode 20 and the monitor electrode 21,
The angular velocity detecting electrode 22 and the common electrodes 28 and 30 and the angular velocity detecting electrodes 23 and 24 and the common electrode 31 are formed with a gap therebetween, and are not conductive.

Further, as shown in FIG.
Terminals (lead terminals) T1 to T4 connected to a control circuit (control means) A10 described later are provided. The terminal T1 is connected to the drive electrode 20 via the wire W1.
The terminal T2 is connected to the pad electrode 37 via the wire W2, the terminal T3 is connected to the monitor electrode 21 via the wire W3, and the terminal T4 is connected to the pad electrode 36 via the wire W4. . The connection of the respective wires is performed by, for example, wire bonding.

Next, the control circuit A10 provided in the angular velocity sensor of this embodiment will be described with reference to the block diagram shown in FIG. As in the first embodiment, the control circuit A10 is roughly divided into a drive system A11 and a detection system A1.
Divided into two. The vibrating member G is connected to a circuit through a pad electrode 37 and is set at a reference potential. Drive system A
Reference numeral 11 denotes a charge amplifier 100 that converts the output (current) from the monitor electrode 21 into a voltage, as in the first embodiment.
And an AGC circuit 101. AGC circuit 1
01 applies this constant voltage to the drive electrode 20 while maintaining the feedback signal from the charge amplifier 100 to be a constant voltage.

The detection system A12 is provided in the current-voltage conversion circuit 102 for converting the output (current) from the angular velocity detection electrodes 22 to 24 into a voltage via the pad electrode 36, and in the current-voltage conversion circuit 102 and thereafter. The synchronous detection circuit 103, the LPF 104 provided after the synchronous detection circuit 103, and the feedback signal from the charge amplifier 100 by 90 °
And a phase shift circuit 105 for phase shifting.

The output from the current-voltage conversion circuit 102 is output to the synchronous detection circuit 103 by the phase shift circuit 105.
After the synchronous detection based on the feedback signal shifted in step (1), the signal is smoothed by the LPF 104, converted into a DC voltage, and output as an angular velocity signal.
Next, the operation of the present embodiment will be described (FIGS. 7 and 8).
(A)). First, by applying an AC voltage between the drive electrode 20 formed on the X1 plane and the X2 plane and the common electrode 29, uneven distribution of electric charge occurs in the drive beams 2 and 3, and the drive beam 2 And 3 resonate in the drive resonance mode as shown in FIG.

Here, as in the first embodiment, the drive signal is applied to the drive electrode 20 while the current proportional to the amplitude output from the monitor electrode 21 is monitored by the AGC circuit 101 in the drive resonance mode. I do. Thus, self-excited oscillation is performed, and drive vibration is performed in the drive beams 2 and 3. In this drive resonance mode, if the angular velocity input about the z-axis is 0, the detection beams 6, 7 hardly vibrate in the y-axis direction.
The output from 24, the noise N, is very small. For example,
The amplitude of the detection beams 6, 7 is about 1/20000 compared to the amplitude of the drive beams 2, 3. This is because the resonance frequency of the drive resonance mode (drive vibration) and the detection beam 6,
This is because the size and shape of the vibration member G are set so that the resonance frequency of the mode in which the bending vibration occurs in the y-axis direction is different from that of the vibration member G, and the details will be described later.

Therefore, in the driving resonance mode, substantially only the driving vibration of the driving beams 2 and 3 is performed. When an angular velocity about the z-axis is input during the drive vibration, Coriolis force is generated in the vibrating drive beams 2 and 3. Then, the driving beams 2 and 3 are
In the x-axis direction orthogonal to the driving vibration direction (direction of the driving resonance mode), the driving beams 2 and 3 receive forces in directions opposite to each other. Due to this force, forces in directions opposite to each other in the x-axis direction (perpendicular to the paper surface in FIG. 7) are generated also in the vicinity of the support portion of the beam portion 2 and the vicinity of the support portion of the beam portion 3 in the connecting portion 4.

Accordingly, the connecting portion 4 generates rotational vibration about the z-axis, and the first torsion beam 9 due to the rotational vibration.
Is transmitted to the second connecting portion 8, and the vibrations are also coupled to the detecting beam portions 6 and 7, and vibrate in opposite directions in the x-axis direction. At this time, also in this embodiment, FIG.
The first detection resonance mode shown in FIG. Here, current-voltage conversion is performed in which the vibrations of the detection beam portions 6 and 7 in the x-axis direction that are opposite to each other in the x-axis direction are detected vibrations, and the amplitude proportional to the angular velocity is output (current) from the angular velocity detection electrodes 22 to 24. The voltage is converted by the circuit 102. This voltage is detected by the synchronous detection circuit 103 based on the feedback signal (monitor signal) from the phase shift circuit 105, and the LPF 10
4 and the final output. This final output produces a DC output (angular velocity signal) proportional to the angular velocity.

The angular velocity detecting electrode 2 on the beam 2 side
The positional relationship between 3 and 24 and the common electrode 31 is the reverse of the positional relationship between the angular velocity detection electrode 22 and the common electrodes 28 and 29 on the beam 5 side. Therefore, in the above-described detection vibration in which the beam 2 and the beam 5 vibrate symmetrically (in opposite phases) in directions opposite to each other, the current detected from the angular velocity detection electrode 22 and the angular velocity detection electrodes 23 and 24 is It has the same phase.

Incidentally, also in this embodiment, similarly to the first embodiment, the width W5 of the first and second torsion beams 9 and 10 (see FIG. 13) is set to be equal to that of the driving beams 2 and 3.
Since the width is smaller than the width W4, vibration leakage due to driving vibration of the driving beams 2 and 3 is suppressed, and unnecessary vibrations in the vibrators 1 and 5 are reduced. Further, similarly to the first embodiment, the first and second torsion beams 9, 10
Are arranged so as to substantially coincide with the z-axis, so that it is easy to transmit only torsional vibration around the z-axis, and vibration (vibration in the x-axis direction) due to Coriolis force from the driving beams 2 and 3. Can be efficiently transmitted to the detection beam portions 6 and 7 as torsional vibration.

Therefore, also in the present embodiment, the first
As in the embodiment, the S / N can be improved by applying the characteristic of the torsion beam that it is easier to transmit only the torsion required for detecting the angular velocity as compared with the related art.
That is, since the first torsion beam 9 mainly transmits only torsional vibration, only when angular velocity is input and the driving beams 2 and 3 rotate and vibrate around the z-axis, and the first torsion beam 9 generates torsional vibration, Detection beams 6, 7
Is transmitted with vibration energy.

Further, also in the present embodiment, FIG.
As shown in the figure, the widths W1 of the drive beams 2, 3 and the detection beams 6, 7 are the same, and the length L1 of the drive beams 2, 3 and the length of the detection beams 6, 7 are provided. L4 is different from L4.
Therefore, the resonance frequencies of the bending modes are different from each other in the drive resonance mode (vibration in the y-axis direction), and even if the drive vibration of the drive beams 3 and 4 (for example, fd = 5310 Hz) is transmitted, the detection beam portion is used. 2, 5 bending vibrations (for example, f
d ₀ = 3976 Hz), and the S / N can be improved.

In the present embodiment, the driving resonance frequency f
The ratio fd / fs between d and the detected resonance frequency fs is, for example, 1.
Since the size of the vibration member G is set to be 13,
The coupling between the drive resonance mode and the detection resonance mode can be suppressed, and S
/ N can be improved. According to the study of the inventor, the ratio fd / fs is preferably in the same range as in the first embodiment also in the present embodiment.

Further, in the present embodiment, as in the first embodiment, the first detection resonance mode (FIG. 8A)
(See FIG. 13) is characterized in that the dimensions of the vibrating member G (see FIG. 13) are formed such that the amplitude ratio XU / XS is 10 or less, which is a point for improving the S / N. In this embodiment, as in the first embodiment, when the ratio XU / XS is reduced in the first detection resonance mode, the vibration energy is also distributed to the detection beams 6, 7, and the Coriolis force is applied. At the time of input, the amplitude (sensitivity S) of the detection beams 6 and 7 in the detection direction (x-axis direction) increases, and the S / N of the sensor can be improved. That is, the ratio WS / W between the beam portions 6, 7 of the outer detecting transducer 5 and the beam portion 2, 3 of the inner driving transducer 1 shown in FIG.
If U is reduced, the amplitude ratio XU / XS can be reduced.

In this example, the ratio WS / WU of this interval is 1.
6 and the first torsion beam 9, the amplitude ratio XU / XS becomes as small as 3.1, and the amplitude of the detection beams 6 and 7 in the detection direction when Coriolis force is input is:
That is, the sensitivity gain S is at the same level as the conventional two-leg tuning fork. By the way, when the first detection resonance mode is used, if the amplitude ratio XU / XS is larger than 10, the sensitivity gain S is reduced by one digit or more compared to the conventional two-leg tuning fork.

As described above, also in the present embodiment, the operation of each torsion beam 9, 10, the difference in resonance frequency in the drive resonance mode of both oscillators 1, 5, the ratio fd / fs
And the vibration setting from the driving beam to the detecting beam is suppressed by the effects of the optimization of the size and the size setting of the vibrating member G such that the amplitude ratio XU / XS ≦ 10. Vibration energy due to Coriolis force can be efficiently transmitted to the detection beam portion, and an angular velocity sensor realizing high S / N can be provided.

Incidentally, if this embodiment is additionally described, the two vibrators 1 and 5 can be formed by etching another piezoelectric material, for example, Z-cut quartz, or by dicing lithium niobate or langasite. , May be formed. In any case, since the piezoelectric body can be manufactured by integral molding, an inexpensive manufacturing cost can be realized. In the present embodiment, the second torsion beam 10 may not be provided. That is, even if the vibrators 1, 5 and the first torsion beam 9 are not supported via the second torsion beam 10 and the bottom of the vibrator 5, that is, the connecting portion 8 is clamped and supported, the first By the effect of the torsion beam 9, the vibration leakage from the driving beam to the detecting beam can be suppressed, and a higher S / N than before can be obtained.

(Third Embodiment) In the first and second embodiments, the first detection resonance mode (see FIG. 8 (a)) is used as the detection resonance mode. The mode is different from the first embodiment in that the mode is the second detection resonance mode shown in FIG. Second embodiment of the present invention
In the detection resonance mode, in the x-axis direction, the driving beam portions 2 and 3 vibrate in the opposite phases to each other, and the detection beam portions 6 and 7 vibrate in the opposite phases to each other. A pair of two beam portions 6 and 2 on one side and a pair of two beam portions 3 and 7 on the other side vibrate in opposite directions.

In order to realize the second detection resonance mode, in the vibrators 1 and 5, the width W1 of each of the beam portions 2, 3, 6, 7 is larger than that in the first and second embodiments. 2) may be reduced. In the present embodiment, the size of the vibration member G is determined by the amplitude XU of the first beams 2 and 3.
In the amplitude XS of the second beam portions 6 and 7, the ratio XS / XU, which is opposite to the ratio XU / XS of the first embodiment, is set to 10 or less, and in the first and second embodiments. It is set so as to satisfy the aforementioned constraint conditions.

In the second detection resonance mode, since the resonator having the same size has a lower resonance frequency than the first detection resonance mode, the frequency of the resonator can be reduced.
Therefore, it can be used in accordance with the configuration of the detection circuit (detection system A12 of the control circuit) requiring low-frequency vibration, the response of the sensor, and the like. (Fourth Embodiment) The configuration of this embodiment is shown in the perspective view of FIG. In each of the above embodiments, in the vibration member G, the second torsion beam 10 (see FIGS.
Are formed so as to extend from the connecting portion 8 in the direction opposite to the second beam portions 6 and 7, but in the present embodiment, the vibration member G
Is characterized in that it has a structure having two second torsion beams (50 and 51 in FIG. 16).

That is, one second torsion beam 50 is formed so as to extend from the second connecting portion 8 in the direction opposite to the second beam portions 6 and 7, and the other second torsion beam 51 is formed by the first torsion beam 51. Are formed so as to extend in the same direction as the first beam portions 2 and 3 from the connecting portion 4 of the first portion. Hereinafter, points different from the above embodiments will be mainly described, and the same portions will be denoted by the same reference numerals in the drawings to simplify the description.

The first and second vibrators 1 and 5 of this embodiment have the same configuration as that shown in FIG.
And 5, respectively, have a first beam part 2, 3 and a first connection part 4, and a second beam part 6, 7 and a second connection part 5,
It has a substantially U-shape. Also in the present embodiment, the first vibrator 1 on the inner peripheral side is a driving vibrator and the second vibrator is located on the outer peripheral side in a similar shape.
The vibrator 5 is configured as a detecting vibrator, and the two vibrators 1
And 5 are connected by a first torsion beam 9. Here, the relationship between each of the transducers 1 and 5 and each axis of the xyz rectangular coordinate system is the same as in the first embodiment.

As shown in FIG. 16, in the present embodiment, the second vibrators 1, 5 and the second torsion beam 9 supporting the first torsion beam 9 are provided.
There are two torsion beams 50 and 51, but for convenience, the upper and lower torsion beams will be referred to as 50 and the upper torsion beam as 51 in FIG. The lower torsion beam 50 is formed so as to extend from the second connecting portion 8 in a direction opposite to the second beam portions 6 and 7,
The upper torsion beam 51 is formed so as to extend from the first connecting portion 4 in the same direction as the first beam portions 2 and 3,
Connection portions 50a and 51a for joining with a frame 52 to be described later are formed at the respective end portions.

The torsion beams 9, 50, 5
1 is located on the center line of the vibrators 1 and 5 (that is, the z axis). The width of each of the torsion beams 9, 50, 51 in the y-axis direction is smaller than the width of the driving vibrator 1 in the y-axis direction (in this embodiment, the arrangement interval W4 of the first beam portions 2, 3). It is assumed. These two oscillators 1 and 5, the first torsion beam 9, and the second torsion beams 50 and 5
The first and both connecting portions 50a and 51a are integrally formed by dicing and cutting a piezoelectric material such as x-cut quartz to form a vibration member G. Note that the axis of the crystal is irrelevant to the xyz rectangular coordinate system, and is set to a desired direction.

The connecting members 50a, 51a and the frame 52 made of glass are joined by a chemical bond, so that the vibration member G is suspended in the frame 52 so that it can freely vibrate. And In the present embodiment, the first and second detection resonance modes can be used as the detection resonance mode. However, as in the above-described embodiments, the vibration member G corresponding to the detection resonance mode to be used is used.
Can be set as a matter of course. Hereinafter, description will be made assuming that the second detection resonance mode is used.

Next, the electrode configuration of this embodiment will be described. The X1, X2, Y1, and Y2 planes of the vibration member G are the same as in the first embodiment, and FIG.
Represents an X1 plane, (b) represents an X2 plane, (c) represents an Y1 plane, and (d) represents an electrode configuration on a Y2 plane. Hereinafter, description will be made with reference to FIG. Also in the present embodiment, in each of the X1 plane and the X2 plane, both the oscillators 1 and 5, the respective torsion beams 9, 50 and 51, and both the connection portions 50a and 51a constitute the same plane.

Reference numerals 60 and 61 denote drive electrodes (drive means), which are formed on the outer peripheral portion of the beam portion 2 and the outer peripheral portion of the beam portion 3, respectively, on the X1 plane. Reference numeral 62 denotes a monitor electrode (monitor means), which is formed on the inner peripheral side of the beam 3 on the X1 plane. 63 and 64 are angular velocity detecting electrodes (angular velocity detecting means) for detecting angular velocity. The angular velocity detection electrode 63 is formed over substantially the entire area of the beam 7 on the Y1 plane, and the angular velocity detection electrode 64 is formed substantially over the entire area of the beam 6 on the Y2 plane.

Then, on the X1 plane, both drive electrodes 6
Reference numerals 0 and 61 denote extraction electrodes 6 formed on the first connecting portion 4.
5 and the connecting portion 4 and the extraction electrode 66 formed on the upper torsion beam 51 are electrically connected to the pad electrode 67 formed on the connecting portion 51a. Also, X
On one surface, the monitor electrode 62 is electrically connected to a pad electrode 69 formed on the connection portion 51a by an extraction electrode 68 formed from the first connection portion 4 to the upper torsion beam 51.

The angular velocity detecting electrode 63 is formed at the connection portion 50a via the extraction electrode 70 formed on the Y1 surface and the extraction electrode 71 formed on the torsion beam 50 on the X1 surface. Is electrically connected to the pad electrode 72. On the other hand, the angular velocity detection electrode 64 is connected to the extraction electrode 73 formed on the Y2 surface and the extraction electrode 74 formed on the torsion beam 50 on the X1 surface via the extraction electrode 73 formed on the connection portion 50a. 75 is electrically connected.

Reference numerals 76, 77, 78, 79, and 80 are common electrodes serving as reference potentials for the drive, monitor, and angular velocity detection electrodes 60 to 64. The common electrode 76 is formed continuously from substantially the entire area of the beam section 6 through the second connecting section 8 to substantially the entire area of the beam section 7 on the X1 plane.
Is formed continuously from substantially the entire area of the beam portion 2 through the first connecting portion 4 to the beam portion 3 on the X2 plane.

The common electrode 78 is formed on substantially the entire area of the beam section 7 on the X2 plane, and the common electrode 79 is formed on almost the entire area of the beam section 6 on the X2 plane. Also, the common electrode 8
0 is formed on the inner peripheral side of the beam 2 in the X1 plane,
Short-circuit electrode 8 formed on the surface facing beam 3
0a (see FIG. 16) is electrically connected to the common electrode 77.

The X2 plane common electrodes 77 to 79 are
The X2 plane is electrically connected by an extraction electrode 81 formed continuously over both the connecting portions 4 and 8 and the first torsion beam 9, and furthermore, a common electrode 78 on the X2 plane and a common electrode on the X1 plane. 76 and the common electrode 79 on the X2 plane through the extraction electrode 82 formed on the Y1 plane.
And the common electrode 76 on the X1 plane are electrically connected via the extraction electrode 83 formed on the Y2 plane.

The common electrode 76 extends from the second connecting portion 8 to the lower torsion beam 50 and the connecting portion 5 on the X1 plane.
It is electrically connected to a pad electrode 85 formed on the connection part 50a via an extraction electrode 84 formed over the area 0a. Therefore, the pad electrode 67 is connected to the drive electrodes 60 and 6.
1, the pad electrode 69 is the monitor electrode 62, the pad electrode 72 is the angular velocity detection electrode 63, the pad electrode 75 is the angular velocity detection electrode 64, and the pad electrode 85 is all the common electrodes 76-8.
0 and each have a conductive form. These pad electrodes are connected to a control circuit (control means) B10 described later by wire bonding. The electrodes 60 to 85 are formed by vapor deposition of Cr, Au, or the like.

Next, the control circuit B10 provided in the angular velocity sensor of the present embodiment will be described with reference to the block diagram shown in FIG. The control circuit B10 mainly detects the drive system B11 that drives and vibrates the drive beams 2 and 3 by self-excited oscillation (self-excited vibration), and detects the detected vibration of the detection beams 6 and 7 to perform angular velocity detection. It is divided into a detection system B12. The vibration member G is connected to the circuit from the pad electrode 85 by wire bonding or the like, and is set at a reference potential.

The driving system B11 includes the driving systems A11 and C1.
1 and the charge amplifier 100 and the AGC
And a circuit 101. Here, the output of the monitor electrode 62 is input to the charge amplifier 100 from the pad electrode 69, and a constant voltage is applied to the drive electrodes 60 and 61 from the AGC circuit 101 through the pad electrode 67 by a feedback signal (monitor signal).

The detection system B12 has the same configuration as the detection system C12. The current-voltage conversion circuit 202a converts the outputs (currents) from the angular velocity detection electrodes 63 and 64 via the pad electrodes 72 and 75 into voltages. , 202b and the differential circuit 2
3, a synchronous detection circuit 103, an LPF 104, and a phase shift circuit 105. Then, similarly to the detection system C12, the current-voltage conversion circuits 202a and 202b
Is output as an angular velocity signal.

Next, the operation of the present embodiment will be described. First, the drive electrodes 60 formed on the X1 plane and the X2 plane,
By applying an AC voltage between 61 and the common electrode 77, the driving beams 2 and 3 resonate in the driving resonance mode as shown in FIG. The output in the drive resonance mode is monitored from the monitor electrode 62 in the same manner as described above, and self-excited oscillation (self-excited oscillation) is performed to drive and vibrate the drive beams 2 and 3.

Also in the present embodiment, the driving beam portions 3 and the detection beam portions 6 and 7 have different resonance frequencies in the mode of bending vibration in the y-axis direction. 4
Are set differently from the length L1 of the detection beam portions 6 and 7, and if the angular velocity input about the z-axis is 0 in the drive resonance mode, the detection beam portions 6 and 7 Hardly vibrates in the y-axis direction, and the output from the angular velocity detecting electrodes 63 and 64, ie, the noise N is extremely small. Accordingly, in the drive resonance mode, substantially only the drive vibration of the drive beams 2 and 3 is performed.

When an angular velocity about the z-axis is input during the drive vibration, the Coriolis force generated in the vibrating drive beams 2 and 3 becomes the first as in the above embodiments. Connection part 4, first torsion beam 9, second connection part 8
Are transmitted in the order of torsional vibration. Therefore, opposite-phase vibrations (detection vibrations) of the detection beam portions 6 and 7 in the x-axis direction are coupled, and the second detection resonance mode shown in FIG. 8B is generated.

The detected vibration causes the angular velocity detecting electrode 6
A current proportional to the amplitude in the x-axis direction, that is, the angular velocity is generated from 3, 64. The current is applied to the pad electrode 72,
The voltage is converted to a voltage by the current-voltage conversion circuits 202a and 202b via the switch 75. Also in the case of the present embodiment, since the outputs from the angular velocity detection electrodes 63 and 64 are generated in opposite phases, similarly to the first embodiment, the differential circuit 203
, A detection process is performed by the synchronous detection circuit 103 based on the feedback signal (monitor signal) from the phase shift circuit 105, and the signal smoothed through the LPF 104 is made the final output. This final output produces a DC output (angular velocity signal) proportional to the angular velocity.

By the way, in this embodiment, the three torsion beams 9, 50, and 51 all have such a narrow width in the y-axis direction and the axis in the z-axis direction substantially coincides with the z-axis. As in the above embodiments, the effect of suppressing vibration leakage, the effect of reducing unnecessary vibration, and the effect of transmitting characteristic of torsional vibration can be realized. Further, in the present embodiment, since the second detection resonance mode is used, the amplitude XU of the drive beams 2 and 3 and the detection beam 6,
The dimensions of the vibrating member G, such as the beam-to-beam spacing ratio WS / WU, are set so that the amplitude ratio XS / XU with the amplitude XS of 7 is 10 or less.

As described above, also in this embodiment, the operation of each of the torsion beams 9, 50, 51, the two vibrators 1, 5
Of the resonance frequency in the drive resonance mode of
By optimizing fs and setting the size of the vibration member G so that the amplitude ratio XS / XU ≦ 10, vibration leakage from the driving beam to the detecting beam can be suppressed, and the driving beam can be suppressed. Vibration energy due to Coriolis force from the section can be efficiently transmitted to the beam section for detection, and an angular velocity sensor realizing high S / N can be provided.

Further, in the present embodiment, since the vibration member G is supported by the torsion beams 50 and 51 having both ends, the vibration member G is superior in impact resistance as compared with cantilever support.
The two torsion beams 50 and 51 can be separated from the wiring of the drive system B11 and the detection system B12, so that they have excellent electrical noise resistance, and they are inexpensive because they are integrally formed of a piezoelectric body.

In the present embodiment, the lower torsion beam 50 has basically the same configuration as the second torsion beam 10 in the first and second embodiments, and the upper torsion beam 51 is a second torsion beam. In the opposite direction to a certain lower torsion beam 50,
Further, it can be regarded as an added third torsion beam.

In this embodiment, if additional writing is performed, the vibration member G may be formed by etching a Z-cut crystal or the like. (Fifth Embodiment) The vibrating member G according to the first to third embodiments.
Are both oscillators 1, 5 and both torsion beams 9, 10
Was integrally formed of a piezoelectric body. The vibrating member G of the present embodiment is based on the vibrating member G of the second embodiment, but the two vibrators 1 and 5 and the two torsion beams 9 and 10 are separately formed and connected and joined. It is characterized by having been done. Hereinafter, parts different from the second embodiment will be mainly described, and the same parts will be denoted by the same reference numerals in the drawings and description thereof will be omitted.

FIG. 19 shows the configuration of this embodiment. The driving vibrator (first vibrator) 1 and the detecting vibrator (second vibrator) 5 are the same as those in the second embodiment, and are made of a piezoelectric material such as PZT. In the first torsion beam 9 of the present embodiment, the connection portions 9a and 9b whose width in the y-axis direction is substantially equal to the width in the y-axis direction of the first connecting portion 4 are formed at both ends by a highly durable material. (For example, a metal such as a 42 alloy). As shown in FIG. 19, one connecting portion 9a is connected to the first connecting portion 4
The other connecting portion 9b is joined to the second connecting portion 8 by bonding or the like, and the first torsion beam 9 is formed by connecting the two vibrators 1 and 5 via the both connecting portions 9a and 9b. Has become.

Further, a connecting portion (oscillator side connecting portion) 10a connected to the second connecting portion 8 is provided at one end of the second torsion beam 10 of the present embodiment, and the first working portion is provided at the other end thereof. A connection portion (substrate-side connection portion) 11 to be joined to the spacer 12 similar to the embodiment is provided by integral molding with the above-mentioned highly durable material. The width of the connection portion 10a in the y-axis direction is
The width is substantially equal to the width of the second connecting portion 8 in the y-axis direction.

That is, the first torsion beam 9 and the two connecting portions 9a and 9b constitute a first supporting portion for connecting the two vibrators 1 and 5, and the second torsion beam 10
The two connecting portions 10a and 11 constitute a second supporting portion that supports the vibrators 1 and 5 and the first supporting portion. As shown in FIG. 19, one connecting portion 10a is
And the other connecting portion 10
b is joined to the spacer 12 by welding or the like, and the second
The torsion beam 10 is configured to support both the vibrators 1 and 5 and the first supporting portion via both connecting portions 10a and 10b. Here, the shape and arrangement of the torsion beams 9 and 10 are the same as in the first and second embodiments.

In this embodiment, the first and second detection resonance modes can be used as the detection resonance mode. However, similar to the above embodiments, the vibration member according to the detection resonance mode to be used is used. Of course, the dimension of G can be set. Next, the electrode configuration of the present embodiment will be described with reference to FIGS. 20 and 21, and is basically the same as that of the second embodiment. FIG. 20 shows an electrode configuration on the first vibrator (driving vibrator) 1.
(A) is the X1 plane, (b) is the X2 plane, (c) is the Y1 plane,
(D) shows an electrode configuration on the Y2 plane, and FIG. 21 shows an electrode configuration on the second vibrator (detection vibrator) 5.
(A) is the X1 plane, (b) is the X2 plane, (c) is the Y1 plane,
(D) shows an electrode configuration on the Y2 plane.

It should be noted that X in the vibrating member G of this embodiment is
The surfaces X1, Y2, Y1, and Y2 are the same as those in the first embodiment. However, here, as shown in FIGS. 20C and 20D, the surface of the vibration member G orthogonal to the y-axis and Of the outer peripheral surfaces of the beams 2 and 3, the same surface as the beam 2 is the Y2 surface of the first vibrator 1, and the same surface as the beam 3 is the first vibrator 1.
In the Y1 plane.

In this embodiment, a first torsion beam 9 made of conductive metal and both connecting portions 9 are used instead of the extraction electrode 33 (see FIG. 14B) in the second embodiment.
The common electrodes 29 and 30 are electrically connected via a and 9b. When the first torsion beam 9 and the connection portions 9a and 9b are not made of a conductive material, the extraction electrode 33 may be formed.

Accordingly, similarly to the second embodiment, the drive electrode 20, the monitor electrode 21, and the angular velocity detection electrodes 22 to 2 are used.
4, common electrodes 28 to 31, lead electrodes 25 to 27 and 32, 34, 35 are formed, the pad electrode 36 is electrically connected to the angular velocity detecting electrodes 22 to 24, and the pad electrode 37 is electrically connected to the common electrodes 28 to 31. It takes shape. Incidentally, each electrode is formed by baking a silver electrode or the like.

Also, the control circuit of the present embodiment is the same as the control circuit A10, and the terminals T1 to T4 and the electrodes 20, 21, 36, and 37 are connected to each other similarly to the second embodiment. As shown in FIG.
Are connected by. And also in this embodiment,
When an angular velocity is input during self-excited vibration (drive vibration) in the drive resonance mode (see FIG. 7), both vibrators 1 and 5 vibrate in the first or second detection resonance mode. Here, an angular velocity signal (DC output) is detected by detecting a detection vibration in the detection vibrator 5.

The difference between the present embodiment and the first to third embodiments is that the vibrators 1 and 5 and the torsion beams 9 and 10 are formed separately and connected and joined. Or the piezoelectric body is integrally formed, and the effects of the vibrator and the torsion beam are the same. Therefore, also in the present embodiment, it is possible to provide an angular velocity sensor having the same effects as those of the first to third embodiments.

Further, in the present embodiment, the driving vibrator 1
Since the first supporting portion for connecting the first torsion beam 9 to the detecting vibrator 5 is integrally formed of metal.
Can be reduced as much as possible while maintaining the strength as compared with the case of molding with a piezoelectric material. Therefore, the vibration energy of the driving vibrator 1 can be further confined than in the first to third embodiments, so that the S / N can be further improved.

(Sixth Embodiment) This embodiment is different from the vibration member G shown in FIGS. 1 and 12 in that the direction in which the second torsion beam extends is the opposite direction. FIG. 22 shows the configuration of the present embodiment. Second torsion beam 9
0 is integrally formed with the vibrator 1 so as to extend from the first connecting portion 4 in the same direction of the first beam portions 2 and 3 and the second beam portions 6 and 7 in the z-axis direction. 1st, 5th and 1st
Is supported.

The center axis (long axis) of the second torsion beam 90 also substantially coincides with the z-axis, and
It is located on the center line of. The end of the torsion beam 90 opposite to the first connecting part 4 is connected to the connecting part 9 connected to the substrate or the frame as described in the above embodiment.
0a. Then, in the portion other than the connecting portion 90a, the width in the y-axis direction is smaller than the arrangement interval of the first beam portions 2, 3.

The vibrating member G is integrally formed from the same piezoelectric material (eg, quartz) as the vibrators 1 and 5 and the torsion beams 9 and 90. Vibration member G
The upper electrode configuration is basically the same as that of the fourth embodiment shown in FIG. 16 described above.
Since there is no torsion beam on the side opposite to 6 and 7, the pad electrodes 72, 75 and 85 are formed on the second connecting portion 8, and the extraction electrodes 71, 74 and 84 are formed only on the second connecting portion 8. I have.

Also in this embodiment, the effect of the torsion beam described in the first and second embodiments can be realized by the first and second torsion beams 9 and 90, and each of the above embodiments can be realized according to the detection resonance mode. alike,
The dimensions can be set so that the S / N can be improved.
Therefore, also in this embodiment, while suppressing vibration leakage from the driving beam to the detecting beam, vibration energy due to Coriolis force from the driving beam can be efficiently transmitted to the detecting beam, An angular velocity sensor that achieves high S / N can be provided.

Further, in the present embodiment, the second torsion beam 90 can be supported at the position of the center of gravity of the vibration member G, and has a feature that it is excellent against external vibration. Further, there is no torsion beam on the side opposite to the beam portions 2, 3, 6, 7 and the space is high in space efficiency in which the second torsion beam 90 is housed between the inner first beam portions 2, 3. Due to the configuration, the torsion beam can be lengthened, and the ratio YU / YS or YS / YU can be reduced, that is, the sensitivity S can be increased.

(Other Embodiments) The vibration member G is shown in FIG.
As shown in FIG. This vibration member G
The vibration member G according to the first embodiment is modified, and z in the opposite direction to each of the beams 2, 3, 6, 7 is sandwiched between the both ends of the second connecting portion 8 with the second torsion beam 10 therebetween. Two frames 15a, 15b extending in the axial direction;
A third connecting portion 16 connecting the two frames 15a and 15b, and a third connecting portion 16 extending in the z-axis direction (each beam portion 2,
And a third torsion beam 17 extending in the same direction as 3, 6, 7).

The second and third torsion beams 10 and 17 are connected by a connecting portion 11, and the two oscillators 1, 5 and the first and third torsion beams 10 and 17 are connected by the second and third torsion beams 10. The second torsion beams 9 and 10 are supported. These frames 15a and 15b, the third connecting portion 16 and the third torsion beam 17 are connected to the two vibrators 1, 5 and the first and second torsion beams.
Are formed integrally with the torsion beams 9, 10.

Here, the third torsion beam 17 is
The first and second torsion beams 9 and 10 are disposed so as to substantially coincide with the center axis in the z-axis direction, and
Has the same configuration, operation and effect as the torsion beams 9 and 10. FIGS. 24, 25, and 26 show the configuration of the electrodes formed on the vibration member G shown in FIG. 24 to 26, each surface X1, X2, Y1
Y8 means the same surface as in the first embodiment. FIG.
4, (a) is the X1 plane, (b) is the Y1 plane, and (c) is the Y8 plane.
25A shows the Y7 plane, FIG. 25B shows the Y6 plane,
(C) is Y5 plane, (d) is Y4 plane, (e) is Y3 plane,
(F) shows the Y2 plane, and FIG. 26 shows the X2 plane.

The drive electrodes (drive means) 420 formed on the respective surfaces X1, X2 and Y3 to Y6 of the inner driving vibrator 1 and electrically connected to each other are, as shown in FIG. The light passes through the first torsion beam 9, the second connecting portion 8, and the second torsion beam 10 and is led to the pad electrode 420 a formed on the connecting portion 11. Also,
Monitor electrodes (monitor means) 421 formed on the respective surfaces X1, X2 and Y3 to Y6 of the driving vibrator 1 and conducting with each other.
Are also routed to the pad electrode 421a formed on the connection portion 11 on the X1 plane.

Each surface X1, X2,
The angular velocity detecting electrodes (angular velocity detecting means) 422 formed on the Y1, Y2, Y7, and Y8 planes and conducting each other are shown in FIG.
As shown in FIG. 26A and FIG. 26, the third connecting portion 1 passes through the frames 15a and 15b on the X2 plane and the X1 plane.
6 and the third torsion beam 17,
Is extended to the pad electrode 422a formed on the substrate.

The electrode 430 is a shield (G
ND), and each surface X1, X of the detecting transducer 5
24, formed on the Y1, Y2, Y7, and Y8 planes and electrically connected to each other. As shown in FIG. 24A, the X1 plane passes through the frames 15a and 15b to the pad electrode 430a formed on the connection portion 11. Have been. This shield electrode 430 may be used as an electrode for detecting angular velocity or for assisting driving.

The vibration member G shown in FIG.
The same operation and effects as described in the first embodiment can be obtained, and the angular velocity detection electrode 422 provided on the outer detection vibrator 5 using the outer peripheral surfaces of the frames 15a and 15b can be obtained. Since the wiring can be routed to the connection portion 11, the distance from the drive electrode 420 can be further increased, which is suitable for suppressing generation of noise.

In each of the above embodiments, of the two vibrators 1 and 5, the inner first vibrator 1 is used as a driving vibrator and the outer second vibrator is used as a detecting vibrator. However, conversely, when the first vibrator 1 is used as a detecting vibrator and the second vibrator 5 is used as a driving vibrator (that is, the first beam portions 2 and 3 are used as detecting beam portions, The same effect can be obtained by using the second beam portions 6 and 7 as driving beam portions).

In each of the above embodiments, the first and second torsion beams have a shape in which the overall width in the y-axis direction is smaller than the width of the first vibrator in the y-axis direction. The width of the first torsion beam is such that the width in the y-axis direction at least at the position where the first torsion beam is in contact with the first connecting portion is smaller than the width of the first vibrator in the y-axis direction. Good.

The width of the second torsion beam is such that the width in the y-axis direction of at least the portion where the second torsion beam is in contact with the connecting portion (first or second connecting portion) is equal to that of the first vibrator. It is sufficient that the width is smaller than the width in the y-axis direction. This also provides the effect of the first and second torsion beams described above. An example is shown in FIG.
(A) and (b). In the first torsion beam 9, the width of the first torsion beam 9 in the y-axis direction at a position where the first torsion beam 9 contacts the first connection portion 4 is smaller than the width of the first connection portion 4 in the y-axis direction. It was done.

Regarding the widths of the torsion beams 9 and 10 in the y-axis direction, more specifically, the width W5 of the first torsion beam 9 in the y-axis direction and the y-axis of the second torsion beam shown in FIG. The width W5 in the direction is preferably equal to or less than ／ of the width W6 in the y-axis direction of the first connecting portion 4. This is when the driving vibrator is driven and vibrated using the ratio W5 / W6 of the width W5 of the first torsion beam 9 in the y-axis direction and the width W6 of the first connecting portion 4 in the y-axis direction as a parameter. This is based on the result of studying the ratio of the amplitude of the driving beam to the amplitude of the detecting beam (amplitude of the detecting beam / amplitude of the driving beam).

An example is shown in FIG. As can be seen from FIG. 28, when the width W5 is equal to or less than ／ (0.6) of the width W6, the amplitude of the detection beam / the amplitude of the drive beam satisfactorily suppresses vibration leakage in the drive resonance mode. It is a level that can be done. The tendency shown in FIG. 28 is the same when the inner first vibrator 1 is a driving vibrator and the outer second vibrator 5 is a detecting vibrator, and vice versa. This also applies to the width W5 of the second torsion beam in the y-axis direction.

In each of the above embodiments, FIG.
Is larger than the width L1 of the first connecting portion 4 in the
It is preferable to increase the width L2 of the connecting portion 8 in the z-axis direction. Thereby, the ratio XU / XS or XS / XU between the amplitude XU of the first beams 2 and 3 and the amplitude XS of the second beams 6 and 7 can be appropriately reduced, and an angular velocity sensor having good sensitivity can be provided. Can be provided.

In each of the above embodiments, the first vibrator 1 and the second vibrator 5 are located on the same plane in the X1 and X2 planes. May be arranged in an offset state. In the second, third and fifth embodiments, 20 is a drive electrode and 21 is a monitor electrode.
May be monitor electrodes and 21 may be drive electrodes. In that case, of course, the connection with the control circuit is changed as appropriate.

In each of the second, third, fourth, and sixth embodiments, the vibrators 1, 5 and each torsion beam 9, 10, 50, 51, 90 are connected to each other as in the fifth embodiment. , May be formed separately. When there is no need to symmetrically vibrate each pair of beam portions 2, 3, 6, 7 of both vibrators 1, 5, each of the torsion beams 9, 10, 50,
51 and 90 need not be arranged on the z-axis, that is, on the central axis of the two vibrators 1 and 5, but may be offset and extend in the z-axis direction.

Each of the torsion beams 9, 10, 5
0, 51, and 90 have a width in the y-axis direction of y of the first vibrator 1.
If it has a shape narrower than the width in the axial direction, the vibration leakage can be suppressed and the vibration energy can be efficiently transmitted. The expression that each of the vibrators 1 and 5 has a substantially U-shape also includes a V-shape that functions as a tuning fork, as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an angular velocity sensor according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing respective dimensions of the vibration member of FIG.

FIG. 3 is an explanatory diagram illustrating a side surface of each beam portion of the vibration member of FIG. 1;

FIG. 4 is a developed view showing an electrode configuration of the vibration member of FIG.

FIG. 5 is a developed view showing an electrode configuration of the vibration member of FIG.

FIG. 6 is a block diagram of a control circuit according to the first embodiment.

FIG. 7 is an explanatory diagram showing a drive resonance mode of the present invention.

FIG. 8 is an explanatory diagram showing a detection resonance mode of the present invention.

FIG. 9 is a diagram showing the size and shape of a two-leg tuning fork as a comparative example.

FIG. 10 is a diagram showing a relationship between an amplitude ratio XU / XS and sensitivity.

FIG. 11 is a diagram showing a relationship between an interval ratio WS / WU and an amplitude ratio XU / XS.

FIG. 12 is a perspective view illustrating a configuration of an angular velocity sensor according to a second embodiment of the present invention.

FIG. 13 is an explanatory diagram showing respective dimensions of the vibration member of FIG.

FIG. 14 is a developed view showing an electrode configuration of the vibration member of FIG.

FIG. 15 is a block diagram of a control circuit according to the second embodiment.

FIG. 16 is a perspective view showing a configuration of an angular velocity sensor according to a fourth embodiment of the present invention.

FIG. 17 is a developed view showing an electrode configuration of the vibration member of FIG.

FIG. 18 is a block diagram of a control circuit according to the fourth embodiment.

FIG. 19 is a perspective view illustrating a configuration of an angular velocity sensor according to a fifth embodiment of the present invention.

20 is a developed view showing an electrode configuration on the first vibrator of FIG.

FIG. 21 is a developed view showing an electrode configuration on the second vibrator of FIG. 19;

FIG. 22 is a perspective view illustrating a configuration of an angular velocity sensor according to a sixth embodiment of the present invention.

FIG. 23 is a view showing a vibration member according to another embodiment of the present invention.

24 is a diagram showing an electrode configuration of the vibration member shown in FIG.

25 is a diagram showing an electrode configuration of the vibration member shown in FIG.

26 is a diagram showing an electrode configuration of the vibration member shown in FIG.

FIG. 27 is a diagram showing a modification of the shape of the torsion beam.

FIG. 28 is a diagram showing the effect of the width of a torsion beam on vibration leakage.

FIG. 29 is a diagram showing a modified example of the vibrator shape.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st vibrator, 2, 3 ... 1st beam part, 4 ... 1st connection part, 5 ... 2nd vibrator, 6 and 7 ... 2nd beam part, 8 ... 2nd connection Part, 9 ... first torsion beam, 10, 5
0, 51, 90 ... second torsion beam, 15a, 1
5b: frame, 16: third connecting portion, 17: third torsion beam, 20, 60, 61, 320, 420 ...
Drive electrode, 21, 62, 321, 421 ... monitor electrode,
22, 23, 24, 63, 64, 322, 323, 42
2. Angular velocity detection electrode.

Claims (24)

[Claims] 1. In a xyz rectangular coordinate system, a pair of first beam portions (2, 3) extending in a z-axis direction;
A substantially U-shaped first vibrator (1) having a first connecting portion (4) connecting the first and second beam portions; and a pair of second beam portions (6, 7) extending in the z-axis direction. And a second connecting portion (8) for connecting the pair of second beam portions, and the U-shaped inner periphery has a U-shaped shape of the first vibrator. A second vibrator (5) disposed so as to be located on an outer peripheral side, one end of which is fixed to the first connecting portion, and the other end of which is fixed to the second connecting portion. And a torsion beam (9) extending in a direction opposite to the first beam portion from the first connection portion and connecting the two vibrators. The torsion beam has a width between the torsion beam and the first connection portion. A width in the y-axis direction at a contacting portion has a shape smaller than a width in the y-axis direction of the first vibrator; One of the first and second vibrators is a driving vibrator (1) and the other is a detecting vibrator (5). The driving vibrator includes a beam (2) of the driving vibrator. ,
3) driving means (20, 60, 61, 320, 420) are provided for exciting and driving vibration in the opposite phase in the y-axis direction, and the detecting vibrator is provided when an angular velocity about the z-axis is input. Angular velocity detecting means (22 to 24, 63, 64) for detecting the generated angular velocity of the beam portion (6, 7) of the detection vibrator in the x-axis direction in opposite phase as the detection vibration. ,
322, 323, 422) are provided. 2. In an xyz rectangular coordinate system, a pair of first beam portions (2, 3) extending in the z-axis direction and a first connecting portion (4) connecting the pair of first beam portions are provided. A substantially U-shaped first vibrator (1), a pair of second beam portions (6, 7) extending in the z-axis direction, and a second connection for connecting the pair of second beam portions. And a second vibrator (a second vibrator (8) arranged so that an inner periphery of the U-shape is located on an outer peripheral side of the U-shape of the first vibrator). 5) and one end portion is fixed to the first connection portion, and the other end portion is fixed to the second connection portion, respectively, and from the first connection portion in a direction opposite to the first beam portion. A first torsion beam (9) extending and connecting the two vibrators; and z from one of the connecting portions (4, 8) of the two connecting portions.
A second torsion beam (10, 5) extending in the axial direction and supporting the two vibrators and the first torsion beam.
0, 51, 90), wherein the width of the first torsion beam is such that the width in the y-axis direction at a position where the first torsion beam is in contact with the first connecting portion is the first vibrator. The width of the second torsion beam is smaller than the width of the second torsion beam at a position where the second torsion beam is in contact with the connecting portion.
The width in the axial direction is smaller than the width in the y-axis direction of the first vibrator. One of the first and second vibrators is a driving vibrator (1), and the other is a driving vibrator. The detection vibrator (5), wherein the driving vibrator includes a beam portion (2,
3) driving means (20, 60, 61, 320, 420) are provided for exciting and driving vibration in the opposite phase in the y-axis direction, and the detecting vibrator is provided when an angular velocity about the z-axis is input. Angular velocity detecting means (22 to 24, 63, 64) for detecting the generated angular velocity of the beam portion (6, 7) of the detection vibrator in the x-axis direction in opposite phase as the detection vibration. ,
322, 323, 422) are provided. 3. A pair of first beam portions (2, 3) arranged in line symmetry with respect to the z-axis and extending in the z-axis direction in an xyz orthogonal coordinate system, and a first beam portion connecting the pair of first beam portions. A substantially U-shaped first vibrator (1) having one connecting portion (4);
A pair of second beam portions (6, 7) arranged symmetrically with respect to the z-axis and extending in the z-axis direction, and a second connecting portion (8) for connecting the pair of second beam portions. A second vibrator (5) arranged so that an inner periphery of the U-shape is located on an outer peripheral side of the U-shape of the first vibrator; A portion is fixed to the first connecting portion, and the other end is fixed to the second connecting portion. The two vibration portions extend from the first connecting portion in a direction opposite to the first beam portion. A first torsion beam (9) for connecting the first and second connecting portions;
A second torsion beam (10, 5) extending in the axial direction and supporting the two vibrators and the first torsion beam.
0, 51, 90), wherein each of the torsion beams has a shape in which the width in the y-axis direction is smaller than the width in the y-axis direction of the first vibrator,
In addition, the first and second vibrators are arranged such that one of the first and second vibrators is a driving vibrator (1) and the other is a detecting vibration. The driving vibrator includes a beam portion (2, 2) of the driving vibrator.
3) driving means (20, 60, 61, 320, 420) are provided for exciting and driving vibration in the opposite phase in the y-axis direction, and the detecting vibrator is provided when an angular velocity about the z-axis is input. Angular velocity detecting means (22 to 24, 63, 64) for detecting the generated angular velocity of the beam portion (6, 7) of the detection vibrator in the x-axis direction in opposite phase as the detection vibration. ,
322, 323, 422) are provided. 4. At the time of inputting the angular velocity, adjacent beam portions among the respective beam portions (2, 3, 6, 7) vibrate in directions opposite to each other in the x-axis direction. The two vibrators (1, 5) and the torsion beam (9, so that the ratio XU / XS between the amplitude XU of the first beam portion and the amplitude XS of the second beam portion during vibration is 10 or less.
The angular velocity sensor according to any one of claims 1 to 3, wherein dimensions (10, 50, 51, 90) are set. 5. At the time of inputting the angular velocity, two beams (2, 6) on one side of the z-axis of each of the beam portions (2, 3, 6, 7).
And the other two (3, 7) vibrate in opposite directions in the x-axis direction, and in the vibration in the x-axis direction, the amplitude XU of the first beam portion and the second beam portion The two oscillators (1, 5) and the torsion beams (9, 10, 5) such that the ratio XS / XU to the amplitude XS of the
The angular velocity sensor according to any one of claims 1 to 3, wherein dimensions (0, 51, 90) are set. 6. An interval WU between the first beams (2, 3) of the first oscillator (1) and the second beams (6, 7) of the second oscillator (5). The angular velocity sensor according to any one of claims 1 to 5, wherein a ratio WS / WU with respect to the interval WS is 2.5 or less. 7. A distance WU between the first beam portions (2, 3) of the first vibrator (1) and the first width of the first vibrator.
The angular velocity sensor according to any one of claims 1 to 6, wherein a ratio WU / HU to a width HU of the beam portion is 2.5 or more and 100 or less. 8. The resonance frequency of the vibration mode in the y-axis direction is different between the first beam part (2, 3) and the second beam part (6,
The angular velocity sensor according to any one of claims 1 to 7, wherein the angular velocity sensor is different from (7). 9. A ratio fd / the ratio of the resonance frequency fd of the driving vibration of the beam part (2, 3) of the driving vibrator to the resonance frequency fs of the detection vibration of the beam part (6, 7) of the detecting vibrator. fs
0.8 ≦ fd / fs ≦ 0.99 or 1.01 ≦ fd
The angular velocity sensor according to any one of claims 1 to 8, wherein a relationship of /fs≤1.2 is satisfied. 10. The device according to claim 1, wherein said two vibrators and said torsion beam are integrally formed of a piezoelectric material. 9. The angular velocity sensor according to claim 1. 11. The device according to claim 1, wherein the two vibrators and the torsion beams are formed separately and joined to each other. 2. The angular velocity sensor according to 1. 12. The second torsion beam (10,
50) is formed so as to extend from said second connecting portion (8) in a direction opposite to said second beam portion (6, 7). The angular velocity sensor according to one of the above. 13. The second torsion beam (51,
90) is formed so as to extend from the first connecting portion (4) in the same direction as the first beam portion (2, 3). The angular velocity sensor according to any one of the above. 14. The second torsion beam (50,
51) are two, and one of the second torsion beams (50) is formed so as to extend from the second connecting portion (8) in a direction opposite to the second beam portions (6, 7). The other second torsion beam (51) is formed to extend from the first connecting portion (4) in the same direction as the first beam portions (2, 3). Item 12. The angular velocity sensor according to any one of Items 2 to 11. 15. A pair of first beam portions (2, 3) extending in the z-axis direction in the xyz rectangular coordinate system, and the pair of first beam portions (2, 3).
A substantially U-shaped first vibrator (1) having a first connecting portion (4) connecting the first and second beam portions; and a pair of second beam portions (6, 7) extending in the z-axis direction. And a second connecting portion (8) for connecting the pair of second beam portions, and the U-shaped inner periphery has a U-shaped shape of the first vibrator. A second vibrator (5) disposed so as to be located on an outer peripheral side, one end of which is fixed to the first connecting portion, and the other end of which is fixed to the second connecting portion. A first torsion beam (9) extending in a direction opposite to the first beam portion from the first connection portion and connecting the two vibrators; and a pair of second torsion beams from a substantially center of the second connection portion. And a second torsion beam (10) extending in the z-axis direction opposite to the beam portion of the second connecting portion. At least two frames (15a, 15a) extending in the z-axis direction opposite to the pair of second beam portions so as to sandwich them.
b) and a third connecting portion (16) for connecting the two frames.
And a third torsion beam (17) extending in the z-axis direction from the third connecting portion. The second and third torsion beams cause the two oscillators, the first torsion beam, and the second torsion beam. A torsion beam is supported, one of the first and second vibrators is a driving vibrator (1), and the other is a detecting vibrator (5); Beam part of the vibrator (2,
3) a driving means (420) for exciting and driving vibration in the opposite phase in the y-axis direction, wherein the detecting vibrator includes the detecting vibrator generated when an angular velocity about the z-axis is input. An angular velocity sensor comprising an angular velocity detecting means (422) for detecting the angular velocity of the beams (6, 7) in opposite phases in the x-axis direction as detection vibration to detect the angular velocity. 16. At the time of inputting the angular velocity, adjacent beam portions among the respective beam portions (2, 3, 6, 7) vibrate in directions opposite to each other in the x-axis direction. The two vibrators (1, 5) and the torsion beam (9, so that the ratio XU / XS between the amplitude XU of the first beam portion and the amplitude XS of the second beam portion during vibration is 10 or less.
16. The angular velocity sensor according to claim 15, wherein dimensions (10, 17) are set. 17. At the time of inputting the angular velocity, two of the beam portions (2, 3, 6, 7) on one side of the z-axis (2, 6)
And the other two (3, 7) vibrate in opposite directions in the x-axis direction, and in the vibration in the x-axis direction, the amplitude XU of the first beam portion and the second beam portion The two vibrators (1, 5) and the torsion beams (9, 10, 1) are arranged such that the ratio XS / XU to the amplitude XS of the torsion beam is 10 or less.
2. The size of 7) is set.
6. The angular velocity sensor according to 5. 18. A space WU between the first beams (2, 3) of the first vibrator (1) and the second beams (6, 7) of the second vibrator (5). ) The ratio WS / WU to the interval WS
The angular velocity sensor according to any one of claims 15 to 17, wherein is less than or equal to 2.5. 19. A ratio WU of a distance WU between the first beam portions (2, 3) of the first vibrator (1) and a width HU of the first beam portion of the first vibrator. / HU is 2.5 or more and 100
The angular velocity sensor according to any one of claims 15 to 18, wherein: 20. The resonance frequency of the vibration mode in the y-axis direction is different between the first beam part (2, 3) and the second beam part (6,
17. The method according to claim 15, wherein the setting is different from the setting in 7).
20. The angular velocity sensor according to any one of claims 19 to 19. 21. A ratio fd / the resonance frequency fd of the driving vibration of the beam portion (2, 3) of the driving vibrator to the resonance frequency fs of the detecting vibration of the beam portion (6, 7) of the detecting vibrator. fs
0.8 ≦ fd / fs ≦ 0.99 or 1.01 ≦ fd
21. The angular velocity sensor according to claim 15, wherein a relationship of /fs≦1.2 is satisfied. 22. The z-axis width of the second connecting portion (8) is larger than the z-axis width of the first connecting portion (4). Any one of 21
The angular velocity sensor according to any one of the above. 23. The width of the first torsion beam (9) in the y-axis direction and the second torsion beam (10).
23. The angular velocity sensor according to claim 1, wherein a width of the first connection portion in the y-axis direction is not more than 3/5 of a width of the first connection portion in the y-axis direction. . 24. A monitoring means for monitoring the driving vibration is provided on the driving beam portions (2, 3).
321 and 421) are provided, and the monitor means (21, 62, 3)
The angular velocity sensor according to any one of claims 1 to 23, wherein the driving beam portion is caused to self-excitedly vibrate based on a monitor signal from (21, 421).