JP2000180180A - Physical amount detector and angular velocity detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid deterioration in accuracy of angular velocity detection due to a variation in machining. SOLUTION: A vibrator 11 floating on a substrate 10 is supported by anchors 16a-1 to 16b-4 via detecting beams 12-1 to 12-4, couplings 13-1, 13-2, driving beams 14a-1 to 14a-4, couplings 15-1 to 15-4 and driving beams 14b-1 to 14c-4 so that it can vibrate both in X-and Y-axis directions. Angular velocity around a Z-axis which is orthogonal to both X-and Y-axis functions while the vibrator 11 is vibrated in an X-axis direction by a driving electrode 17, and the vibrator 11 vibrates in a Y-axis direction in proportion to the angular velocity. Control electrodes 25-1 to 25-4 are provided on the driving beams 14a-1 to 14a-4, electrostatic attraction due to the electrodes 25-1 to 25-4 is changed by changing applied DC voltage, and a spring constant of the driving beams 14a-1 to 14c-4 is electrically controlled, thereby eliminating leakage vibration of the vibrator 11 in the Y-axis direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a physical quantity detecting device for detecting physical quantities such as angular velocity, acceleration, and pressure based on displacement of a mass body displaceably supported on a substrate upper surface via a beam with respect to the substrate, and The present invention relates to an angular velocity detection device that uses the same physical quantity as an angular velocity.

[0002]

2. Description of the Related Art Conventionally, as a physical quantity detecting device of this type, for example, the technical digest of the 16th Sensor Symposium published in 1998, pp. 37-40 (Te
chnical Digest of the 16th Symposium, 1998, pp. 37-4
0), JP-A-10-103960, and 1997
IEEE Transducer (Trnsducer '97)
As described on pages 1129 to 1132,
A mass body suspended above the substrate upper surface, a plurality of beams extended above the substrate upper surface and connected at each end to the mass body, and each other end fixed to the substrate upper surface, respectively; A driving electrode for causing the substrate to vibrate in the X-axis direction with respect to the substrate, and a detection electrode for detecting vibration of the mass body with respect to the substrate in the Y-axis direction orthogonal to the X-axis direction. Z that is orthogonal to both X and Y axes
An angular velocity detecting device for detecting an angular velocity around an axis is well known. Japanese Patent Application Laid-Open No. 10-103960 discloses that a part of a drive signal for vibrating a mass body in the X-axis direction electrically leaks in the Y-axis direction (hereinafter, this leak signal is referred to as crosstalk). In order to prevent this crosstalk from appearing as noise, a correction electrode for vibrating the mass body in the Y-axis direction is provided, and the vibrating body is vibrated in the Y-axis direction by the amount of canceling the crosstalk. Are also shown.

[0003]

However, in this kind of angular velocity detecting device, not only the angular velocity detection error due to the crosstalk but also the cross-sectional shape, width, height,
Since there is a great effect due to variations in beam processing such as length, the vibrating body cannot be vibrated and displaced with high accuracy, and there has been a problem that the angular velocity detection accuracy cannot be improved.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem of the conventional angular velocity detecting device. In addition, the object of the present invention is to provide a mass body supported displaceably via beams on the upper surface of the substrate. In general physical quantity detection device that detects physical quantities such as angular velocity, acceleration, and pressure based on displacement,
An object of the present invention is to solve the problem of beam processing variations and minimize errors in detected physical quantities.

[0005] In order to achieve the above-mentioned object, a structural feature of the present invention is that a mass body suspended above the upper surface of a substrate is provided;
A plurality of beams that are extended above the board and connected at one end to the mass body and each other end is fixed to the board top face, respectively, to detect physical quantities based on the displacement of the mass body with respect to the board In the physical quantity detection device for performing, for at least one of the plurality of beams, a beam-side electrode finger connected to the intermediate portion of the at least one beam and a substrate-side electrode finger connected to the upper surface of the substrate An adjustment electrode is provided so as to face each other and change the spring constant of the at least one beam.

In this case, it is preferable that both the beam-side electrode fingers and the substrate-side electrode fingers extend in the same direction as the extending direction of the beam to which the beam-side electrode fingers are connected. In use, it is preferable that a variable voltage source circuit is connected to the beam-side electrode finger and the substrate-side electrode finger of the adjustment electrode so that a DC voltage can be applied between both electrode fingers and the applied voltage can be changed. .

According to this, even when the vibrating body cannot be accurately displaced due to variations in processing of the beams, by changing the spring constant of at least one of the plurality of beams, the mass of the mass body is changed. Since the displacement can be adjusted,
The accuracy of detecting the physical quantity based on the displacement of the mass body can be improved.

Another feature of the present invention is that a driving electrode for vibrating the mass body in the X-axis direction with respect to the substrate is provided, comprising a mass body and a plurality of beams similar to the above. A detection electrode for detecting the vibration of the mass body with respect to the substrate in the Y-axis direction orthogonal to the X-axis direction, and detecting an angular velocity about the Z-axis acting on the substrate and orthogonal to both the X and Y axes; In the angular velocity detection device for detecting, for at least one of the plurality of beams, a beam-side electrode finger connected to the intermediate portion of the at least one beam and a board-side electrode finger connected to the top surface of the board And an adjusting electrode for changing the spring constant of the at least one beam is provided.

Also in this case, it is preferable that both the beam-side electrode fingers and the substrate-side electrode fingers extend in the same direction as the extending direction of the beam to which the beam-side electrode fingers are connected. In use, it is preferable that a variable voltage source circuit is connected to the beam-side electrode finger and the substrate-side electrode finger of the adjustment electrode so that a DC voltage can be applied between both electrode fingers and the applied voltage can be changed. .

[0010] According to this, even when the beam cannot be displaced with high accuracy due to variations in processing of the beam, the detection accuracy of the angular velocity can be improved by adjusting the displacement of the mass body by changing the spring constant as described above. Can be good.

Another feature of the present invention is that, in the angular velocity detection device, both the X and Y axes are axes parallel to the upper surface of the substrate, and the plurality of beams are moved in the Y-axis direction. The extended drive beam and the detection beam extended in the X-axis direction are connected to each other, and the adjustment electrode is provided on the drive beam.

According to this, when the driving electrode cannot accurately vibrate the vibrating body in the X-axis direction due to a variation in processing of the driving beam, the spring constant of at least one driving beam is determined. By changing the
Vibration can be accurately performed in the axial direction. as a result,
The angular velocity can be accurately detected based on the vibration of the vibrating body in the Y-axis direction.

Another structural feature of the present invention resides in that an adjustment electrode is provided on a detecting beam in place of the driving beam.

According to this, the angular velocity is accurately detected by the vibrating body not accurately vibrating in the Y-axis direction due to the Coriolis force or the rotational center of the vibrating body being displaced due to a variation in processing of the detection beam. Even in the case where it is not possible, by changing the spring constant of at least one detection beam portion, it is possible to obtain accurate vibration of the vibrating body in the Y-axis direction due to Coriolis force, and it is possible to accurately detect the angular velocity.

[0015]

DETAILED DESCRIPTION OF THE INVENTION a. First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of an angular velocity detecting element formed of a semiconductor according to the present invention, and FIG. It is a figure or an end view. 1 and 2, the substrate 10
The pattern is different between a member having a gap between the upper surface and a member having no gap.

This angular velocity detecting element is provided with a vibrator 11 as a mass body on a substrate 10 formed in a square shape of silicon.
Is floated by a predetermined distance from the upper surface thereof and arranged in a horizontal plane. The vibrator 11 is vibrating in the X-axis direction (horizontal direction in the drawing), and has an amplitude proportional to the magnitude of the angular velocity by an angular velocity about a Z-axis (through-the-sheet direction) orthogonal to both X and Y axes. It vibrates in the Y-axis direction (vertical direction in the figure), and has a plurality of small rectangular through holes 11a formed in a square shape. The vibrator 11 includes the vibrator 1
1, the detection beam portions 12-1 to 12-4 and the connection portions 13-1 and 13 provided to be floated from the substrate 10 by a predetermined distance.
-2, drive beam parts 14a-1 to 14a-4, 14b-1
To 14b-4, 14c-1 to 14c-4 and the connecting portion 15
By -1 to 15-4, it is supported on the substrate 10 so as to be able to vibrate.

The detection beams 12-1 to 12-4 are formed in a long shape with a small width, are connected at one ends to respective corners of the vibrator 11, and extend in the X-axis direction. Provided to allow the vibrator 11 to vibrate in the Y-axis direction. The connecting portions 13-1 and 13-2 have a relatively large width and extend in the Y-axis direction, and connect the other ends of the detecting beam portions 12-1 to 12-4 to the driving beam portions 14a. -1 to 14a-4, respectively. Drive beams 14a-1 to 14a
-4, 14b-1 to 14b-4, 14c-1 to 14c-
Numeral 4 is formed in a narrow shape with a narrow width, and extends in the Y-axis direction to allow the vibrator 11 to vibrate in the X-axis direction. The connecting portions 15-1 to 15-4 have a relatively large width and extend in the X-axis direction, and the driving beam portions 14a-1 to 14a-1.
The other end of 14a-4 is connected to the driving beam portions 14b-1 to 14b-
4 and one end of each of the drive beams 14c-1 to 14c-4. Driving beams 14b-1 to 14b-
4, 14c-1 to 14c-4 are respectively connected to anchors 16a-1 to 16a-4 and 16b-1 fixed on the substrate 10.
To 16b-4. Note that, even in the wide connecting portions 13-1, 13-2, 15-1 to 15-4, a through hole 11a similar to the vibrator 11 is appropriately formed due to a manufacturing problem described later. Is also good.

A driving electrode 1 for vibrating the vibrator 11 with respect to the substrate 10 in the X-axis direction is provided on the substrate 10.
7, a drive monitoring electrode 18 for monitoring the vibration of the vibrator 11 with respect to the substrate 10 in the X-axis direction, and a vibrator 11
A pair of detection electrodes 21 and 22 for detecting the vibration of the vibrator 11 with respect to the substrate 10 in the Y-axis direction, and a pair of control electrodes 23 and 24 for suppressing the vibration of the vibrator 11 with respect to the substrate 10 in the Y-axis direction. Is provided.

The driving electrode 17 is a comb-shaped electrode 17 provided at a position outside the connecting portion 13-1 in the X-axis direction (left position in the drawing).
and the comb-shaped electrode 17 provided integrally with the connecting portion 13-1
b. The comb-shaped electrode 17a includes a plurality of electrode fingers that are fixed on the substrate 10 and extend in the X-axis direction toward the connecting portion 13-1 and are arranged at equal intervals in the Y-axis direction. The comb-teeth-shaped electrode 17b is provided with a plurality of electrode fingers at equal intervals in the Y-axis direction, which are floated on the substrate 10 and extend outward from the connecting portion 13-1 in the X-axis direction. The electrode 17a penetrates the center position in the width direction of each adjacent electrode finger and faces the adjacent electrode finger. A pad portion 17c fixed on the substrate 10 and connected to the comb-teeth electrode 17a is provided at a position outside the comb-teeth electrode 17a in the X-axis direction (a left position in the drawing). Is provided with an electrode terminal 17d made of a conductive metal (for example, aluminum).

The drive monitor electrode 18 is connected to the connecting portion 13-2.
And a comb-shaped electrode 18b provided integrally with the connecting portion 13-2. Comb-shaped electrode 18a
Is fixed on the substrate 10 and X
It includes a plurality of electrode fingers extending in the axial direction and arranged at equal intervals in the Y-axis direction. The comb-shaped electrode 18b is provided with a plurality of electrode fingers at equal intervals in the Y-axis direction, which are floated on the substrate 10 and extend outward from the connecting portion 13-2 in the X-axis direction. The electrode 18a penetrates the center position in the width direction of each adjacent electrode finger and faces the adjacent electrode finger. Comb electrode 18
The substrate 10 is located at the outer position in the X-axis direction of FIG.
A pad portion 18c fixed to the top and connected to the comb-shaped electrode 18a is provided.
Is provided with an electrode terminal 18d formed of a conductive metal (for example, aluminum).

The detection electrodes 21 and 22 are connected to the Y
Comb-shaped electrode 2 provided at an axially outer position (a lower position in the figure)
1a and 22a, and comb-shaped electrodes 21b and 22b provided integrally with the vibrator 11. The comb-shaped electrodes 21a and 22a each include a plurality of electrode fingers that are fixed on the substrate 10 and extend in the X-axis direction and are equally spaced in the Y-axis direction. Each of the comb-tooth electrodes 21b and 22b includes a plurality of electrode fingers that are floated on the substrate 10 and extend in the X-axis direction and are equally spaced in the Y-axis direction.
a, 22a penetrate between the adjacent electrode fingers and face the adjacent electrode fingers, respectively. However, the comb-shaped electrode 21b
Are arranged to be shifted downward in the drawing from the center position in the width direction between adjacent electrode fingers of the comb-shaped electrode 21a,
On the other hand, each electrode finger of the comb-shaped electrode 22b is
It is provided so as to be shifted upward in the figure from the center position in the width direction between adjacent electrode fingers a. Y of the comb-shaped electrodes 21a and 22a
Pad portions 21c, 22c fixed to the substrate 10 and connected to the comb-shaped electrodes 21a, 22a, respectively, are provided at axially outer positions (lower positions in the drawing). , 22c are provided with electrode terminals 21 and 21 formed of a conductive metal (for example, aluminum).
2d are provided respectively.

The control electrodes 23 and 24 are connected to the Y
Comb-shaped electrode 2 provided at an axially outer position (upper position in the figure)
3a and 24a, and comb-shaped electrodes 23b and 24b provided integrally with the vibrator 11. The comb-shaped electrodes 23a and 24a each have a plurality of electrode fingers fixed on the substrate 10 and extended in the X-axis direction and spaced at equal intervals in the Y-axis direction. The comb-tooth electrodes 23b and 24b are provided with a plurality of electrode fingers at equal intervals in the Y-axis direction, which are floated on the substrate 10 and extended in the X-axis direction.
a and 24a penetrate between the adjacent electrode fingers and face the adjacent electrode fingers, respectively. However, the comb-shaped electrode 23b
Are arranged to be shifted upward in the drawing from the center position in the width direction between the adjacent electrode fingers of the comb-shaped electrode 23a,
When a voltage is applied to the comb-shaped electrode 23a, the control electrode 23 suppresses the displacement of the vibrator 11 in the Y-axis direction downward by electrostatic attraction. On the other hand, each electrode finger of the comb-shaped electrode 24b is provided to be shifted downward from the center position in the width direction between adjacent electrode fingers of the comb-shaped electrode 24a, and a voltage is applied to the comb-shaped electrode 24a. At this time, the control electrode 24 suppresses the upward displacement of the vibrator 11 in the Y-axis direction due to electrostatic attraction. Outer position in the Y-axis direction of comb-shaped electrodes 23a and 24a (upper position in the figure)
Are fixed on the substrate and each of the comb-shaped electrodes 23
Pad portions 23c and 24c connected to the respective pads a and 24a are provided, and electrode terminals 23d and 24d formed of a conductive metal (for example, aluminum) are provided on the upper surfaces of the pad portions 23c and 24c, respectively. I have.

Further, on the substrate 10, a driving beam portion 14 is provided.
a-1, 14b-1, and 14c-1, the spring constants of the drive beams 14a-2, 14b-2, and 14c-2, and the spring constants of the drive beams 14a-3, 14b-3, and 14c-3. Spring constant and drive beams 14a-4, 14b-4, 14c-4
The adjustment electrodes 25-1 to 25-4 that can independently change the spring constants of the two are provided.

The adjusting electrodes 25-1 to 25-4 are connected to the comb-shaped electrodes 25a-1 to 25a-4 provided at positions outside the connecting portions 15-1 to 15-4 in the Y-axis direction, respectively. 15-1
Comb-shaped electrodes 25b-1 to 25-25 provided integrally with 15-4
b-4. Comb-shaped electrode 2
5a-1 to 25a-4 are respectively provided with a plurality of electrode fingers at regular intervals in the X-axis direction fixed on the substrate 10 and extended in the Y-axis direction toward the connecting portions 15-1 to 15-4. Have. The comb-shaped electrodes 25b-1 to 25b-4 are a plurality of electrode fingers spaced apart from each other in the X-axis direction at equal intervals in the X-axis direction and extended from the connecting portions 15-1 to 15-4 to the outside in the Y-axis direction. , And each electrode finger has a comb-shaped electrode 25a-1 to 25a-2.
5a-4 penetrates into the center position in the width direction of each adjacent electrode finger and faces the adjacent electrode finger. Comb-shaped electrode 2
Pad portions 25c- fixed on the substrate and connected to the comb-shaped electrodes 25a-1 to 25a-4 are located at outer positions in the Y-axis direction (left positions in the drawing) of 5a-1 to 25a-4.
1 to 25c-4 are provided, and electrode terminals 25d-1 to 25-2 formed of a conductive metal (for example, aluminum) are provided on the upper surfaces of the pad portions 25c-1 to 25c-4.
5d-4 are provided.

An anchor 16a-3 is provided on the substrate 10.
Is provided. The pad 26a is fixed to the upper surface of the substrate 10, and a conductive metal (for example, aluminum) is formed on the upper surface of the pad 26a.
Is provided.

Next, a method of manufacturing the angular velocity detecting element having the above configuration will be briefly described with reference to FIG. First,
SOI (Silicon-On-Ins) in which a single crystal silicon layer C is provided on the upper surface of the single crystal silicon layer A via a silicon oxide film B
ulator) A substrate is prepared, and the single crystal silicon layer C is doped with an impurity such as phosphorus to lower the resistance of the same layer C. Hereinafter, this layer is referred to as a low resistance layer C. Next, portions with the pattern of FIG. 1 (except for the through-hole 11a of the vibrator 11, etc.), various beam portions 12-1 to 12-4, and 14a-1 to 14 are provided.
a-4, 14b-1 to 14b-4, 14c-1 to 14c
-4 and various comb-shaped electrodes 17a, 17b, 18a, 18
b, 21a to 24a, 21b to 24b, 25a-1 to 2
5a-4, 25b-1 to 25b-4 and the like are masked with a resist film, and the single crystal silicon layer C is etched by reactive ion etching or the like, and anchors 16a-1 to 16a are formed on the silicon oxide film B. -4, 16b-1 to 16b-
4, various comb-shaped electrodes 17a, 18a, 21a to 24a,
25a-1 to 25a-4 and various pad portions 17c, 1
8c, 21c to 24c, 25c-1 to 25c-4, 26
a and the like (the portions described above as being fixed to the substrate 10).

Next, the silicon oxide film B excluding the formed portion is removed by etching with a hydrofluoric acid aqueous solution or the like, and the vibrator 11, the various beam portions 12-1 to 12-4, 14a-1 to 14a-1 are removed.
14a-4, 14b-1 to 14b-4, 14c-1 to 1
4c-4, connecting parts 13-1, 13-2, 15-1 to 15
-4 and comb-shaped electrodes 17b, 18b, 21b to 24b,
25b-1 to 25b-4 (portions described as floating above the substrate 10 by a predetermined distance) are formed. Then, various pad portions 17c, 18c, 21c to 24c, 2
Aluminum or the like is vapor-deposited on 5c-1 to 25c-4, 26a to form terminal electrodes 17d, 18d, 21d to 24d, 2
5d-1 to 25d-4, 26b are formed. Therefore, the above-described portions formed on the substrate 10
Is composed of an insulated low-resistance layer C, and includes a vibrator 11, various beam portions 12-1 to 12-4, and 14a-1 to 14-1.
4a-4, 14b-1 to 14b-4, 14c-1 to 14
c-4, connecting parts 13-1, 13-2, 15-1 to 15-
4, and comb-shaped electrodes 17b, 18b, 21b to 24b,
25b-1 to 25b-4 are positioned floating above the substrate 10 by a predetermined distance, and the anchors 16a-1 to 16a-
The structure supported by the substrate 10 so as to be able to vibrate is provided by 4, 16b-1 to 16b-4.

An electric circuit device for detecting an angular velocity using the angular velocity detecting element constructed as described above will be described. FIG. 3 is a block diagram showing the electric circuit device.

A self-exciting circuit 31a is connected to the terminal electrode 17d via an amplitude control circuit 31b, and a capacitance detecting circuit 31c is connected to the terminal electrode 18d. The self-excited oscillation circuit 31a has a self-excited oscillator built therein, and based on the output of the capacitance detection circuit 31c, a sine of a frequency substantially equal to the resonance frequency of the oscillator 11 for causing the oscillator 11 to vibrate in the X-axis direction. Outputs a wave signal. Amplitude control circuit 31
b is the vibrator 1 based on the output of the capacitance detection circuit 31c.
The amplitude of the sine wave signal from the self-exciting circuit 31a is controlled so that the amplitude of the vibration in the X-axis direction of the terminal electrode 1 becomes constant.
The voltage is applied to the comb-shaped electrode 17a of the driving electrode 17 via 7d. The capacitance detection circuit 31c applies a capacitance detection signal composed of an AC signal or a DC signal to the comb-like electrode 18a of the detection electrode 18 via the terminal electrode 18d, and
Of the vibrator 11 in the X-axis direction in the capacitor constituted by the eight comb-tooth electrodes 18a and 18b, and detects the frequency and amplitude of the X-axis vibration of the vibrator 11 based on the detection result. Self-exciting circuit 31
a and the amplitude control circuit 31b.

A capacitance detection circuit 32a is connected to the terminal electrodes 21d and 22d, and the terminal electrodes 23d and 2d are connected.
4d, the output of the self-exciting circuit 31a is
b, are connected via a phase compensation circuit 32c and a waveform shaping circuit 32d. The capacitance detection circuit 32a includes the terminal electrode 2
Each of the capacitance detection signals composed of an AC signal or a DC signal is applied to each of the comb-like electrodes 21a and 22a of the detection electrodes 21 and 22 via 1d and 22d, respectively. , 21b and the comb-shaped electrodes 22a, 22b of the detection electrode 22 detect the respective capacitance changes associated with the vibration of the vibrator 11 in the Y-axis direction in each of the capacitors. Also, this capacitance detection circuit 32a
By subtracting the signals representing the respective capacitance changes, the parasitic capacitances of the detection electrodes 21 and 22 with respect to the respective substrates 10 are cancelled, and only the signal representing the amplitude of the vibration of the vibrator 11 in the Y-axis direction is transferred to the displacement control circuit 32e. Output to The output signal of the self-exciting circuit 31a is also supplied to the capacitance detection circuit 32a for synchronous detection.

The displacement control circuit 32e controls the vibration of the vibrator 11 in the Y-axis direction detected by the capacitance detection circuit 32a in order to control the amplitude of the vibration of the vibrator 11 in the Y-axis direction within a predetermined small range. And outputs a signal that increases as the amplitude of the vibration increases. This is the vibrator 11
The output signal of the displacement control circuit 32e also indicates the magnitude of the angular velocity in order to prevent the amplitude of the vibration in the Y-axis direction from becoming large and not being exactly proportional to the magnitude of the angular velocity around the Z-axis. Therefore, the output terminal O of this electric circuit device
It is also output from the UT as a signal representing the angular velocity.

The amplitude control circuit 32b includes a self-excitation circuit 31a.
Proportional control (the amplitude of the sine wave signal is controlled to increase as the output signal from the displacement control circuit 32e increases) according to the output signal from the displacement control circuit 32, and the proportional control is performed. The obtained sine wave signal is output to the phase compensation circuit 32c. The phase compensation circuit 32c adjusts the phase of the sine wave signal from the amplitude control circuit 32b, and adjusts the phase of the sine wave signal from the self-exciting circuit 31a and the vibration of the vibrator 11 in the Y-axis direction accompanying the angular velocity around the Z-axis. The deviation is compensated for. The waveform shaping circuit 32d includes a phase compensating circuit 32c.
Independently extracts the half-wave signal on the positive side and the half-wave signal on the negative side of the sine wave signal, and inverts the half-wave signal on the negative side to the positive side to form two half-wave signals. When the actuator 11 is displaced downward in the Y-axis direction, one of the two half-wave signals is applied to the comb-like electrode 23a of the control electrode 23 via the terminal electrode 23d to suppress the displacement of the vibrator 11. I do. When the vibrator 11 is being displaced upward in the Y-axis direction, the other of the two half-wave signals is applied to the comb-like electrode 24a of the control electrode 24 via the terminal electrode 24d, and The displacement is suppressed.

Further, the electric circuit device is controlled by the leakage vibration control circuit 33a and the terminal electrode 25
DC variable power supply circuits 33b-1 to 33b-4 connected to d-1 to 25d-4, respectively.

The leak vibration control circuit 33a controls the adjusting electrodes 25-1 to 25-4 so that the vibrator 11 vibrates accurately only in the X-axis direction when the angular velocity about the Z-axis is not acting.
It controls the DC voltage applied to the electric circuit device, and is adjusted when the electric circuit device is assembled or mounted on a vehicle.
Or, even after the vehicle is mounted, when the vehicle is stopped or the like, when the angular velocity is not acting, it automatically operates to form a control signal, and when the electric circuit device operates, each DC variable power supply circuit 33
Control signals are continuously output to b-1 to 33b-4. The DC variable power supply circuits 33b-1 to 33b-4 respond to the control signal from the leakage vibration control circuit 33a to adjust the electrode 25- via the terminal electrodes 25d-1 to 25d-4.
A DC voltage is applied to each of the comb-like electrodes 25a-1 to 25a-4. The magnitude of the applied voltage and the combination of the applied electrodes are determined by the leakage vibration control circuit 33a so that the output of the capacitance detection circuit 32a is minimized.

The terminal electrode 26b is grounded.
Thus, the comb-shaped electrode 17b of the driving electrode 17, the comb-shaped electrode 18b of the drive monitoring electrode 18, the comb-shaped electrode 21b of the detection electrodes 21, 22 connected to the terminal electrode 26b by the low resistance layer, and the like. 22b, comb-shaped electrodes 23b and 24b of control electrodes 23 and 24, and adjustment electrodes 25-1 to 25-25
-4 comb-shaped electrodes 25b-1 to 25b-4 are grounded.

In the first embodiment configured as described above, as shown in FIG. 3, an angular velocity detecting element is connected to an electric circuit device to form an angular velocity detecting device, and then the device is shipped and shipped to a vehicle. In one or both of the mounting, the driving beam portions 14a-1 to 14a-4, 14b-1 to 14b-1
The spring constants of 14b-4, 14c-1 to 14c-4 are adjusted. In this adjustment, the sine wave signal from the self-exciting circuit 31a is applied to the comb-shaped electrode 17a of the driving electrode 17 to vibrate the vibrator 11 in the X-axis direction, and the angular velocity around the Z-axis is set to "0". In this state, the spring constants are changed to eliminate the leakage vibration of the vibrator 11 in the Y-axis direction. In this case, since the angular velocity is “0”, the vibrator 11 should not vibrate in the Y-axis direction, and a signal representing the angular velocity “0” should appear at the output terminal OUT. But,
Each part of angular velocity detecting element, drive beam parts 14a-1 to 14a
-4, 14b-1 to 14b-4, 14c-1 to 14c-
In the case where there is a variation in processing in No. 4 and leakage vibration in the Y-axis direction occurs in the vibrator 11 and a signal representing the angular velocity “0” is not output to the output terminal OUT, the signal from the output terminal OUT The leak vibration control circuit 33a is adjusted until the indicated angular velocity approaches “0” as much as possible. In this adjustment, DC voltages corresponding to the adjustment are output from the DC variable power supply circuits 33b-1 to 33b-4, respectively, and the comb-shaped electrodes 25a-1 to 25a- of the adjustment electrodes 25-1 to 25-4. 4 and comb-shaped electrodes 25b-1 to 25b-25
b-4. The driving beams 14a-1 to 14a-4, 1 are applied by the respective DC voltages.
The spring constants of 4b-1 to 14b-4 and 14c-1 to 14c-4 are changed, and leakage vibration of the vibrator 11 in the Y-axis direction can be minimized.

The driving beams 14a-1 to 14a-4,
Changes in the spring constants of 14b-1 to 14b-4 and 14c-1 to 14c-4 will be described using the adjustment electrode 25-3 as an example. FIG. 4 shows an enlarged view of the adjustment electrode 25-3. In FIG. 4, the DC variable power supply circuit 33b is shown.
-3 is indicated as 33b-3 '. In this case, between the comb-shaped electrodes 25a-3 and 25b-3,
A voltage having the comb-teeth shaped electrode 25a-3 on the positive side is applied.
If each electrode finger of the comb-shaped electrode 25b-3 is located at the center in the width direction of the comb-shaped electrode 25a-3 as shown in the drawing, the comb-shaped electrode 25
Each of the electrode fingers b-3 is evenly pulled in the horizontal direction in the drawing by electrostatic attraction with each of the electrode fingers of the comb-tooth electrode 25a-3. In this state, the pulling force due to the electrostatic attraction is comb-shaped. It does not act on the electrode 25b-3. However, when the comb-tooth electrode 25b-3 is displaced in the left-right direction from the illustrated state, each electrode finger of the comb-tooth electrode 25b-3
5a-3 approaches one of the adjacent electrode fingers. Thereby, each electrode finger of the comb-like electrode 25b-3 is
Since each electrode finger on the side closer to a-3 is pulled by a greater force, the comb-like electrode 25b-3 is easily displaced in the left-right direction. The pulling force increases as the output voltage of the DC variable power supply circuit 33b-3 'increases.

As a result, as the output voltage of the DC variable power supply circuit 33b-3 'increases, the adjusting electrode 25-3 drives the drive beams 14a-3, 14b-3, and 14c-.
3 acts so as to be easily deformed in the X-axis direction. In other words, the adjustment electrode 25-3 is connected to the DC variable power circuit 3
Since the output voltage of 3b-3 'increases, it acts to reduce the spring constants of the drive beams 14a-3, 14b-3, and 14c-3. This driving beam 14a-
The spring constant k per pair of electrode fingers of 3, 14b-3 and 14c-3 is represented by the following equation (1).

[0039]

[Number 1] _{k = k M - (εSV T} 2 / d T 3) However, k _M of the number in 1 driving beam portion 14a-3, 1
4b-3 and 14c-3 are the mechanical spring constants, ε is the dielectric constant of the environment where the adjustment electrode 25-3 is placed, and S
Is the opposing area of the electrode fingers adjacent each of the interdigital electrodes 25b-3,25a-3, V _T is the interdigital electrodes 25b-3,2
5T is an applied voltage between 3a and 3d, and d _T is a comb-shaped electrode 25b.
-3, 25a-3 are the distances between adjacent electrode fingers. The driving beams 14a-1, 14a-2, and 14a-4 by the other adjustment electrodes 25-1, 25-2, and 25-4, and the driving beams 14b-1, 14b-2, and 14b-4. The same applies to the change of the spring constant of the drive beam portions 14c-1, 14c-2, and 14c-4. Therefore, the driving beam portions 14a-1 to 14a-4, 14b-1 can be adjusted by the above-described leakage vibration control circuit 33a.
The spring constants of 14b-4 and 14c-1１〜14c-4 are changed, so that leakage vibration of the vibrator 11 in the Y-axis direction can be sufficiently suppressed.

Next, the operation of detecting the angular velocity around the Z-axis using the angular velocity detecting device that has been adjusted will be described. As described above, when the sine wave signal from the self-excited oscillation circuit 31a is applied to the comb-shaped electrode 17a of the driving electrode 17, the vibrator 11 drives the driving beams 14a-1 to 14a-4, 14b.
Vibration in the X-axis direction is caused by the spring action of -1 to 14b-4 and 14c-1 to 14c-4. The same applies to the adjustment of the spring constant described above. However, the capacitance detection circuit 31c detects the amplitude of the vibration of the vibrator 11 in the X-axis direction, outputs a control signal representing the amplitude to the amplitude control circuit 31b, and controls the amplitude. The circuit 31b controls the amplitude of the vibration of the vibrator 11 in the X-axis direction to be always constant. Thereby, the vibrator 11 vibrates at a constant amplitude in the X-axis direction. In this state, when the angular velocity around the Z axis acts on the substrate 10 and the vibrator 11, the vibrator 11 receives Coriolis force proportional to the angular velocity and detects the beam 1 for detection.
Due to the spring action of 2-1 to 12-4, it starts to vibrate in the Y-axis direction with an amplitude proportional to the angular velocity.

The vibration of the vibrator 11 in the Y-axis direction is detected by the capacitance detection circuit 32a, and a signal representing the amplitude of the vibration of the vibrator 11, ie, the angular velocity about the Z-axis (however,
A signal representing the vibration suppressed by the control electrodes 23 and 24) is output from the displacement control circuit 32e via the output terminal OUT. At this time, the amplitude control circuit 32b, the phase compensation circuit 32c, and the waveform shaping circuit 32d
Based on the sine wave signal from 1a and the control signal from the displacement control circuit 32e, the control signal application to the comb-like electrodes 23a and 24a of the control electrodes 23 and 24 is controlled, and the Y-axis direction of the vibrator 11 is controlled. Is limited to a predetermined small range. Thereby, even if the angular velocity around the Z axis increases, the amplitude of the vibration of the vibrator 11 is maintained with good linearity, and the angular velocity is accurately detected.

Even when the angular velocity is being detected as described above, if the apparatus is mounted on a vehicle, the leakage vibration may occur while the angular velocity around the Z axis is not acting, such as when the vehicle is stopped. The control circuit 33a automatically operates, and the output terminal OU
The output voltages of the DC variable power supply circuits 33b-1 to 33b-4 are automatically determined so that a signal representing the angular velocity "0" is output to T. The determined voltage is stored and used for detecting the angular velocity thereafter. As a result, the driving beam 1
4a-1 to 14a-4, 14b-1 to 14b-4, 14
Even if the spring constants of c-1 to 14c-4 change over time, the changes are corrected, and the angular velocity is always accurately detected.

As described above, in the first embodiment, the driving beams 14a-1 to 14a-4, 14b-1 to 14b- which allow the vibrator 11 to vibrate in the X-axis direction.
4, 14c-1 to 14c-4, adjusting electrodes 25-1 and 25-2
5-4 were provided. Then, the adjusting electrodes 25-1 to 25-
4 by applying a changeable DC voltage from the DC variable power supply circuits 33b-1 to 33b-4.
a-1 to 14a-4, 14b-1 to 14b-4, 14c
The spring constants of -1 to 14c-4 can be changed independently.
Thereby, according to the first embodiment, the driving beam 1
4a-1 to 14a-4, 14b-1 to 14b-4, 14
Even if other parts mainly including c-1 to 14c-4 have processing variations, or each part changes with time, the driving beam parts 14a-1 to 14a-4, 14b-1 to 14b- 4,1
By adjusting the spring constants of 4c-1 to 14c-4, the leakage vibration component of the vibrator 11 in the Y-axis direction due to the driving of the vibrator 11 in the X-axis direction can be minimized. Since the vibrator 11 can be vibrated in the X-axis direction with high accuracy, the angular velocity can always be detected with high accuracy based on the vibration of the vibrator 11 in the Y-axis direction.

The adjusting electrodes 25-1 to 25-4
Can be modified as shown in FIGS.
5A to 5C, the adjusting electrode 25-3 is also representatively shown.
Will be described only.

In FIG. 5A, an extension 15-3a is formed integrally with the connecting portion 15-3 so as to float on the substrate 10.
Is extended from the connecting portion 15-3 in the Y-axis direction opposite to the driving beam portion 14a-3, and an adjustment electrode 25-3 is provided on one end in the X-axis direction at the tip of the extension portion 15-3a. ing. In this case as well, the adjustment electrode 25-3 is composed of a comb-shaped electrode 25a-3 fixed to the substrate 10 and a comb-shaped electrode 25b- 3 Each electrode finger of the comb-shaped electrodes 25a-3 and 25b-3 extends in the same Y-axis direction as the drive beam portion 14a-3.

In FIG. 5B, an adjustment electrode 25-3 configured in the same manner as in FIG. 5A is provided on one side of the connecting portion 15-3 in the X-axis direction, and the comb-shaped electrode 25b- 3 for connecting part 15
-3.

In FIG. 5C, the drive beams 14a-3, 14b-3,
The driving beams 14b-3 and 14c-3 are omitted without folding back the 14c-3, and the other end of the driving beam 14a-3 linearly extending in the Y-axis direction is connected to the anchor 16c.
-3 directly. The adjustment electrode 25-3 is provided on one side of the driving beam 14a-3 in the X-axis direction, and the comb-shaped electrode 25b-3 is directly connected to the driving beam 14a-3.

5A to 5C, the comb-shaped electrodes 25a-3 and 25a of the adjustment electrode 25-3 are also provided.
Each of the electrode fingers b-3 is a driving beam 14a-3, 14b-
3, 14c-3 (in FIG. 5C, the driving beam portion 14a
-3), and the adjustment electrode 25-3 is connected to the drive beams 14a-3, 14b-3, and 14 respectively.
Since the spring constant of c-3 is changed, the same effect as in the first embodiment is expected.

B. Second Embodiment Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a plan view of an angular velocity detecting element formed of a semiconductor according to the second embodiment. In FIG. 6, the same members as those in the above embodiment are denoted by the same reference numerals as those in FIG. 1, and detailed description thereof will be omitted.

Also in the second embodiment, the vibrator 11 ′ as a mass body is arranged in a horizontal plane so as to float a predetermined distance above the upper surface of the substrate 10 formed of silicon in a square shape. In this case, the vibrator 11 ′ is formed in an H-shape, and the detection beam portions 12 are provided on both sides in the Y-axis direction of the vibrator 11 ′.
One ends of -1 to 12-4 are connected. The other ends of these detection beams 12-1 to 12-4 are connected to the vibrator 11 '.
In the same manner as described above, they are connected to respective ends of slightly wide connecting portions 13-3 and 13-4 which are floated on the substrate 10 and extended in the X-axis direction.

The driving beams 14d-1 to 14d- are located at symmetrical positions on the outer side in the Y-axis direction of the intermediate portions of the connecting portions 13-3 and 13-4.
4 are connected to each other, and the driving beam portion 14d-
Reference numerals 1 to 14d-4 extend outward in the Y-axis direction, respectively. The other ends of the driving beams 14d-1 to 14d-4 are X
A slightly wide connecting portion 15-5, 15-extended in the axial direction.
6 are connected to symmetrical positions on the inner side in the Y-axis direction of the intermediate portion. One ends of driving beams 14e-1 to 14e-4 are respectively connected to both ends of the connecting portions 15-5 and 15-6, and the driving beams 14e-1 to 14e-4 are in the Y-axis direction. Each is extended inside. Drive beam 14e-1
14e-4 are connected to anchors 16-1 to 16-4 fixed on the substrate 10, respectively. The driving beam portions 14d-1 to 14d-4, 14e-1 to 14e-1
14e-4 and connecting portions 15-5 and 15-6 are also provided on the substrate 10
It is provided floating above. Also in the second embodiment, the vibrator 11 ′ and the connecting portions 13-3 and 13-.
Wide portions such as 4, 15-5 and 15-6 may be appropriately provided with through holes as in the case of the first embodiment due to the above-described manufacturing problem.

A pair of divided driving electrodes 17-for driving the vibrator 11 ′ in the X-axis direction with respect to the substrate 10 is provided at each end on the left side of the connecting portions 13-3 and 13-4. 1,
17-2 are provided. Driving electrodes 17-1, 17
-2 is a comb-like electrode 17 similar to the driving electrode 17 described above.
a-1, 17a-2 and comb-shaped electrodes 17b-1, 17b-
2 respectively. Driving electrode 17-
Each of the comb-shaped electrodes 17a is provided on the outside of the
-1, 17a-2 respectively connected to the pad portion 1
7c and a pad portion 17c-1, similar to the terminal electrode 17d,
17c-2 and terminal electrodes 17d-1 and 17d-2 are provided, respectively.

A pair of divided drive monitoring electrodes for monitoring the vibration of the vibrator 11 ′ with respect to the substrate 10 in the X-axis direction are provided at the right ends of the connecting portions 13-3 and 13-4 in the drawing. 18-1 and 18-2 are provided. Similarly to the drive monitor electrode 18, the drive monitor electrodes 18-1 and 18-2 are respectively constituted by comb electrodes 18a-1 and 18a-2 and comb electrodes 18b-1 and 18b-2. Have been. X of drive monitor electrodes 18-1 and 18-2
Comb-shaped electrodes 18a-1, 18a-2 are provided on the outer sides in the axial direction.
And pad portions 18c-1 and 18c-2 and terminal electrodes 18d-1 and 18d-2 similar to the pad portion 18c and the terminal electrode 18d, respectively.

At each left end of the vibrator 11 ′ in the figure, detection electrodes 21 ′ and 2 corresponding to the detection electrodes 21 and 22 are provided.
2 'are provided respectively. These detection electrodes 2
The electrodes 1 'and 22' are fixed to the substrate 10 and extend in the X-axis direction, and the electrode fingers 21a 'and 22a' and the vibrator 11 'are floated on the substrate 10 and extended in the X-axis direction. Electrode fingers 21b 'and 22b'.
a ′, 22a ′ and the electrode fingers 21b ′, 22b ′ face each other. The electrode fingers 21a 'and 22a' are
1c, 22c and the electrode terminals 21d, 22d, respectively.

The control electrodes 23 ', 2 corresponding to the control electrodes 23, 24 are provided on each right end of the vibrator 11' in the figure.
4 'are provided. These control electrodes 2
The electrode fingers 3a and 24 'are fixed to the substrate 10 and extend in the X-axis direction. The electrode fingers 23a' and 24a 'and the vibrator 11' are floated on the substrate 10 and extended in the X-axis direction. Electrode fingers 23b 'and 24b'.
a ', 24a' and the electrode fingers 23b ', 24b' face each other. The electrode fingers 23a 'and 24a' are
3c, 24c and electrode terminals 23d, 24d, respectively.

At both ends of the connecting portions 15-5 and 15-6,
The adjustment electrodes 25-1 and 25-2 arranged as shown in FIG.
5-4 are provided. Adjustment electrode 25-1
To 25-4 of the comb-shaped electrodes 25a-1 to 25a-4,
Pad portions 25c-1 to 25c-4 and electrode terminals 25d-
1 to 25d-4 are respectively connected. The pad 16a and the electrode terminal 26b are connected to the anchor 16-3.

The angular velocity detecting element according to the second embodiment configured as described above is manufactured by the same method as the angular velocity detecting element according to the first embodiment. In addition, the second
An electric circuit device for detecting an angular velocity using the angular velocity detecting element according to the embodiment is also configured substantially in the same manner as the first embodiment, but the electrode terminals 17d-1 and 17d-2 are controlled by the amplitude control of the first embodiment. The electrode terminals 18d-1 and 18d-2 are commonly connected to the circuit 31b, and are commonly connected to the capacitance detection circuit 31c of the first embodiment. The other points are the same as in the first embodiment.

Next, the operation of detecting the angular velocity around the Z-axis using the angular velocity detecting device configured as described above will be described. Similarly to the above, the sine wave signal from the self-exciting circuit 31a is applied to the comb-shaped electrodes 17-1 and 17-2 of the driving electrodes 17-1 and 17-2.
a-1 and 17a-2, a detection signal indicating the frequency of the vibration of the vibrator 11 'in the X-axis direction is fed back from the capacitance detection circuit 31c to the self-excited oscillation circuit 31a, and a detection indicating the amplitude of the vibration is performed. Signal to amplitude control circuit 3
1b, and the driving beams 14d-1 to 14d-14
The vibrator 11 'is vibrated at a constant amplitude in the X-axis direction using the spring action of d-4, 14e-1 to 14e-4. Then, a signal representing the angular velocity is extracted from the output terminal OUT via the capacitance detection circuit 32a and the displacement control circuit 32e. As a result, also in the angular velocity detecting device according to the second embodiment, the angular velocity around the Z axis is detected with high accuracy.

Also in the angular velocity detecting device according to the second embodiment, an angular velocity detecting element is incorporated in an electric circuit device, the electric circuit device is mounted on a vehicle, or the Z-axis around the Z axis when the vehicle is stopped. In the state where the angular velocity is not acting, the DC variable power supply circuits 33b-1 to 33b-4 are controlled by the leak vibration control circuit 33a to adjust the adjustment electrodes 25-1 to 25-1.
By independently applying a DC voltage to the driving beams 25-4, the driving beams 14d-1 to 14d-4, 14e-1 to 14e-
Adjust the spring constant of 4. As a result, also in the second embodiment, the drive beam portions 14d-1 to 14d-4, 14
Even if other parts mainly including e-1 to 14e-4 have processing variations, or each part changes over time, the driving beam parts 14d-1 to 14d-4, 14e-1 to 14e- By adjusting the spring constant of No. 4, it is possible to minimize the leakage vibration component of the vibrator 11 in the Y-axis direction due to the driving of the vibrator 11 in the X-axis direction, Vibrator 1
The angular velocity can always be accurately detected based on the vibration in the Y-axis direction.

In the second embodiment, similarly to the first embodiment, the adjusting electrodes 25-1 to 25-4 are used.
Can be variously modified as shown in FIGS. 4 and 5A to 5C.

C. Third Embodiment Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a plan view of an angular velocity detecting element formed of a semiconductor according to the third embodiment.

Also in the third embodiment, the vibrator 51 as a mass body is arranged in a horizontal plane so as to float a predetermined distance above the upper surface of the substrate 10 formed in a square shape of silicon. The vibrator 51 is formed in an H-shape.
One end of each of the detection beams 52-1 to 52-4 is connected to both sides in the Y-axis direction. These detection beams 52-1
Each of the other ends of .about.52-4 is floated on the substrate 10 in the same manner as the vibrator 51, and is extended in the X-axis direction to form an I-shaped slightly wider connecting portion 53-1 or 53-2. Terminator 53-1
a, 53-1b, 53-2a, and 53-2b. Termination parts 53-1a, 53-1b, 53-
2a and 53-2b extend in the Y-axis direction.

The driving beams 54a-1 to 54a- are located at symmetrical positions on the outer side in the Y axis direction of the connecting portions 53-1 and 53-2.
4 are connected to each other, and the driving beam 54a-
Reference numerals 1 to 54a-4 extend outward in the Y-axis direction, respectively. The other ends of the driving beams 54a-1 to 54a-4 are X
Slightly wide connecting portions 55-1, 55- extending in the axial direction
The two intermediate portions are connected to symmetrical positions on the inner side in the Y-axis direction. One end of each of the drive beams 54b-1 to 54b-4 is connected to each end of each of the connecting portions 55-1 and 55-2, and the drive beams 54b-1 to 54b-4 are in the Y-axis direction. Each is extended inside. Drive beam 54b-1
54b-4 are connected to anchors 56-1 to 56-4 fixed on the substrate 10, respectively. The driving beams 54a-1 to 54a-4, 54b-1 to 54b-1
54b-4 and the connecting portions 55-1, 55-2 are also provided on the substrate 10
It is provided floating above. Also in the second embodiment, the vibrator 51, the connecting portions 53-1 and 53-2,
Due to the manufacturing problem described above, the through-holes 51a, 55-2 are provided in the same manner as in the first embodiment.
3a and 55a are provided.

The end portions 53-of the connecting portions 53-1 and 53-2
Divided drive electrodes 57-1 to 57 for vibrating the vibrator 51 in the X-axis direction with respect to the substrate 10 are provided on the outer sides of the 1a, 53-1b, 53-2a, and 53-2b in the X-axis direction.
-4 are provided. Driving electrode 57-1
57-4 are comb-like electrodes 57a-1 to 57a-4 and comb-like electrodes 57b-1 to 57b-4, similarly to the drive electrode 17.
b-4. Driving electrode 5
At the outside of the X-axis direction of 7-1 to 57-4, a comb-shaped electrode 5 is provided.
7a-1 to 57a-4 connected to the pad 17c and the pad 57c similar to the terminal electrode 17d, respectively.
1 to 57c-4 and terminal electrodes 57d-1 to 57d-4 are provided, respectively.

The end portions 53-of the connecting portions 53-1 and 53-2
1a, 53-1b, 53-2a, and 53-2b, the connecting portions 53-1 and 53-2 and the vibrator 51
Drive monitoring electrodes 58-1 to 58-4 for monitoring the vibration of the substrate 10 in the X-axis direction are provided. Drive monitoring electrodes 58-1 to 58-58
-4, similarly to the drive monitor electrode 18, the comb-shaped electrodes 58a-1 to 58a-4 and the comb-shaped electrodes 58b-1 to 58b-5.
8b-4. Pad portions 58c similar to the above-mentioned pad portions 18c and terminal electrodes 18d connected to the comb-like electrodes 58a-1 to 58a-4, respectively, are provided on the outer sides of the drive monitoring electrodes 58-1 to 58-4 in the X-axis direction. -1 to 58c-4 and terminal electrodes 58d-1 to 58
d-4 are provided.

The arms 51b-1 to 51b of the vibrator 51
-4, the detection electrodes 61-1 to 61-
4 are provided. Detection electrodes 61-1 to 6
1-4 are comb-shaped electrodes 61a-1 to 61a-1 which are fixed to the substrate 10 and have a plurality of electrode fingers extending on both the inner and outer sides in the X-axis direction.
61a-4, and comb-shaped electrodes 61b-1 to 61-6 each including a plurality of electrode fingers extending outward from the transducer 51 in the X-axis direction.
1b-4 and comb-shaped electrodes 61c-1 to 61c-4 each of which is provided at an intermediate position between the arm portions 51b-1 to 51b-4 and extends inward in the X-axis direction and includes a plurality of electrode fingers. . Comb-shaped electrodes 61b-1 to 61b-4, 61c-1
61c-4 are formed integrally with the vibrator 51 and are formed so as to float from the substrate 10. Comb-shaped electrode 61b-1
61b-4, 61c-1 to 61c-4,
It penetrates between adjacent electrode fingers of the comb-shaped electrodes 61a-1 to 61a-4 and faces the adjacent electrode fingers. However, the comb-shaped electrodes 61b-1, 61c-1, 61b-2, 61c
-2 are provided downwardly in the figure from the center in the width direction between the electrode fingers of the comb-shaped electrodes 61a-1 and 61a-2, and are provided below the comb-shaped electrodes 61b-3, 61c-3, 61b-
4, 61c-4 are comb-shaped electrodes 61a-3, 6
1a-4 are provided to be shifted upward in the drawing from the center in the width direction between the electrode fingers. Comb-shaped electrodes 61a-1 to 61a-4
Include pad portions 61 d-1 to 61 d fixed to the substrate 10.
d-4 and the electrode terminals 61e-1 to 61e-4 are respectively connected.

The arm portions 51b-1 to 51b of the vibrator 51
-4, the detection beam portions 52-1 to 52-
4 for adjusting the spring constant of No. 4
2-4 are provided. Adjusting electrode 62-1
62a to 62-4 are electrode fingers 62a-1 to 62a-4 fixed to the substrate 10 and extended in the X-axis direction;
Arms 51b-1 to 51b-5 in the middle of -1 to 51b-4
The electrode fingers 62a-1 to 62a-4 and the electrode fingers 62b-1 are integrally formed with the electrode fingers 62b-1 to 62b-4 and extended in the X-axis direction while floating from the substrate 10 integrally with the electrode fingers 1b-4.
To 62b-4 face each other. Electrode finger 6
2a-1 to 62a-4 have pad portions 62c-1 to 62c-4 fixed on the substrate 10 and electrode terminals 62d-1 to 62d-1.
62d-4 are respectively connected.

In this case, the adjustment electrodes 62-1 and 62-2
Are the electrode fingers 62a-1 and 62a-2 and the electrode fingers 62b
-1 and 62b-2, the arm portions 51b-1 and 51b-2 of the vibrator 51 are displaced downward in FIG.
1, 51b-2 functions to facilitate displacement by electrostatic attraction, and the tendency increases as the DC voltage increases. Adjusting electrodes 62-3, 62-4
Are the electrode fingers 62a-3 and 62a-4 and the electrode fingers 62b
When the DC voltage is applied to the arm portions 51b-3 and 62b-4, as the arm portions 51b-3 and 51b-4 of the vibrator 51 are displaced upward in the drawing, the arm portions 51b-3 and 51b-4 are displaced upward.
In addition to functioning to facilitate the displacement of 3, 4 by electrostatic attraction, the tendency increases as the DC voltage increases. That is, the detection beam portions 52-1 to 52-
The spring constant of No. 4 corresponds to the electrode fingers 62a-1 to 62a-4 and the electrode fingers 62b- in the adjustment electrodes 62-1 to 62-4.
It decreases as the DC voltage between 1 and 62b-4 increases.

Further, an anchor 56-
3, drive beam parts 54a-3, 54a-4, 54b-3,
A pad section 63a is provided which is electrically connected to the vibrator 51 via the connection section 54b-4, the connecting sections 55-2 and 53-2, and the detection beam sections 52-3 and 52-4. Pad section 63
a is formed integrally with the anchor 56-3 and is fixed to the upper surface of the substrate 10, and an electrode terminal 63b is provided on the upper surface of the pad portion 63a.

The angular velocity detecting element according to the third embodiment configured as described above is manufactured by the same method as the angular velocity detecting element according to the first and second embodiments. An electric circuit device for detecting an angular velocity using the angular velocity detecting element according to the third embodiment will be described. The circuit device is as shown in FIG.

The terminal electrodes 61e-1 and 61e-2 connected to the detection electrodes 61-1 and 61-2 have a high-frequency oscillator 7 connected thereto.
1 is connected, and the oscillator 71 generates a detection signal E ₁ si having a frequency f _{1 which} is extremely higher than the resonance frequency of the vibrator 51.
n (2πf ₁ t) is supplied to the terminal electrodes 61e- _{1 and} 61e-2. This high-frequency oscillator 71 includes a phase inversion circuit 71a.
Is connected, and the same circuit 71a outputs the detection signal E ₁ s
In (2πf ₁ t) the detection signal E ₁ sin (2π
f ₁ t + π) is supplied to the terminal electrodes 61e-3 and 61e-4 connected to the detection electrodes 61-3 and 61-4.

A high-frequency oscillator 72 is connected to the terminal electrodes 58d-1 and 58d-3 connected to the drive monitoring electrodes 58-1 and 58-3.
A monitoring signal E ₂ sin (2πf ₂ t) having a frequency f ₂ which is much higher than the resonance frequency of ₁ and different from the frequency f ₁ is supplied to the terminal electrodes 58d-1 and 58d-3. A phase inversion circuit 72a is connected to the high-frequency oscillator 72,
This circuit 72a is terminal electrodes 58d connected monitor signal E ₂ sin (2 [pi] f ₂ t) monitor signal E ₂ obtained by inverting the phase of sin a (2πf ₂ t + π) to drive the monitor electrodes 58-2,58-4 -2, 58d-4. Thereby, each vibration of the vibrator 51 in the X and Y axis directions is expressed by E _0x sin (2πf ₀ t),
When expressed as E _0y sin (2πf ₀ t), a signal output from the terminal electrode 63b and representing each vibration of the vibrator 51 in both the X and Y axes directions is E ₂ · E _0x · sin (2πf ₀ t).・ Sin (2πf
₂ t), the _{E 1 · E 0y · sin (} 2πf 0 t) · sin (2πf 1 t). The frequency f ₀ is a frequency near the resonance frequency of the vibrator 51.

Each of the terminal electrodes 57d-1 to 57d-4 connected to the driving electrodes 57-1 to 57-4 has a driving circuit 8
0 is connected. The drive circuit 80 includes a terminal electrode 63b.
From the terminal electrodes 57d-1 to 57d- based on a signal input from the
4

The drive circuit 80 includes a demodulation circuit 81, a phase shift circuit 82 and a gain control circuit 83 connected in series to the charge amplifier 73, and is connected to the demodulation circuit 81 to control the gain of the gain control circuit 83. A detection circuit 84 is provided. Demodulation circuit 81, a signal outputted from the terminal electrode 63b by detecting synchronism with the frequency f ₂ (frequency 2 [pi] f ₂
Take out the amplitude envelope of the signal of
A signal E _0x sin (2πf ₀ t) representing the vibration component in the X-axis direction is output. The phase shift circuit 82 outputs a detection signal representing the vibration of the vibrator 51 with respect to a signal for driving the vibrator 51 by π /
In order to correct the delay by 2 (= 1 / 8πf ₀ seconds), the phase of the input signal is advanced by π / 2 and output. The detection circuit 84 synchronously detects the signal from the demodulation circuit 81 at the frequency f ₀ (extracts the amplitude envelope of the vibration component of the vibrator 20 in the X-axis direction) and outputs the vibration component of the vibrator 51 in the X-axis direction. And outputs a signal E _0x representing the amplitude of.
The gain control circuit 83 includes a phase shift circuit 82 and a gain control circuit 8.
The gain of the output signal from the phase shift circuit 82 is controlled in accordance with the signal E _0x from the detection circuit 84 so that the amplitude of the input signal of No. 3 (the amplitude of the vibration component of the vibrator 20 in the X-axis direction) is constant. That is, the output is controlled so that the amplitude of the output signal of the gain control circuit 83 decreases as the signal from the detection circuit 84 increases.

The drive circuit 80 includes a gain control circuit 83
, And adders 84-1 and 84-3 connected to the outputs of the gain control circuit 83.
Are also provided via adders 84-2 and 84-4. The phase inversion circuit 83a inverts the phase of the signal from the gain control circuit 83 and outputs the inverted signal. Adders 84-1 and 84-
With a variable voltage source circuit 85a for outputting a DC voltage E _T which is variably adjusted is connected to 2, the adder 84-3,
A constant voltage source circuit 85b which outputs a fixed DC voltage E _B is connected to 84-4.

The adder 84-1 outputs the signal from the gain control circuit 83
Signal E_0x'sin (2πf₀t) and the variable voltage source circuit 85a
DC voltage signal E_TAnd an addition voltage E_T+
E_0x'sin (2πf₀t) is connected to the driving electrode 57-1.
To the terminal electrode 57d-1. The adder 84-2 is
Signal E from phase inversion circuit 83a_0x'sin (2πf₀t +
π) and the DC voltage signal E from the variable voltage source circuit 85a._TAnd
Add the added voltage E_T+ E _0x'sin (2πf₀t + π)
The terminal electrode 57d-2 connected to the operating electrode 57-2 is provided.
Pay. The adder 84-3 receives the signal from the gain control circuit 83.
No. E_0x'sin (2πf₀t) and the direct voltage from the constant voltage source circuit 85b.
Current voltage signal E_BAnd an addition voltage E_B+ E_0x'sin
(2πf₀t) is the terminal voltage connected to the driving electrode 57-3.
Supply to pole 57d-3. The adder 84-4 performs phase inversion.
Signal E from circuit 83a_0x'sin (2πf₀t + π) and constant current
DC voltage signal E from pressure source circuit 85b_BAnd add
Addition voltage E _B+ E_0x'sin (2πf₀t + π) to drive electrode 5
It supplies to terminal electrode 57d-4 connected to 7-4.

The charge amplifier 73 is connected in series.
From the demodulation circuit 91, the detection circuit 92 and the amplifier 93
Output circuit 90 is connected. The demodulation circuit 91
The signal output from terminal electrode 63b is converted to frequency f₁Sync with
Detect (frequency 2πf₁The amplitude envelope of the signal
Out), and represents a vibration component of the vibrator 51 in the Y-axis direction.
Signal E_0ysin (2πf₀t) is output. The detection circuit 92
The signal from the demodulation circuit 91 is represented by a frequency f₀With synchronous detection
T (the amplitude envelope of the vibration component of the vibrator 51 in the Y-axis direction)
Of the vibration component of the vibrator 51 in the Y-axis direction.
Signal E representing amplitude _0yIs output. The amplifier 93 is connected to the signal
No. E_0yIs input to the Y-axis of the vibrator 51 from the output terminal OUT.
A signal representing the magnitude of the directional vibration is output.

Further, DC variable power circuits 74-1 to 74-4 are connected to the terminal electrodes 62d-1 to 62d-4 connected to the adjustment electrodes 62-1 to 62-4. The DC variable power supply circuits 74-1 to 74-4 change the output voltage according to the manual operation.

In the third embodiment configured as described above, after the angular velocity detecting element is connected to the electric circuit device to configure the angular velocity detecting device as shown in FIG. 3, the Z-axis rotation is performed before the device is shipped. Output terminal O with the angular velocity of
A signal representing the magnitude of the vibration of the vibrator 51 in the Y-axis direction is extracted from the UT. In this case, since the angular velocity is “0”, the output signal should be “0”, but if not “0”, the variable voltage source circuit 85a and the variable DC power supply circuit 74−
1～74-4 by changing the DC voltage signal E _T by adjusting the changes to the output signal becomes "0".

First, the adjustment of the variable voltage source circuit 85a will be described.
In other words, the driving electrodes 57-1 and 57-2 are driven.
Voltage signal E_T+ E_0x'sin (2πf₀t), E_T+ E_0x'sin (2
πf ₀t + π) = E_T-E_0x'sin (2πf₀t) is applied
At the same time, a driving voltage is applied to the driving electrodes 57-3 and 57-4.
Signal E_B+ E_0x'sin (2πf₀t), E_B+ E_0x'sin (2πf
₀t + π) = E_B-E_0x'sin (2πf₀t) is applied
You. When the angular velocity detecting element is configured with high accuracy
Is a DC voltage signal E from the variable voltage source circuit 85a._TAnd fixed
DC voltage signal E from voltage source circuit 85b_BAnd
If it is fixed, the connecting parts 53-1 and 53-2 are applied with electrostatic attraction.
A uniform force acts in the X-axis direction, and the connecting portions 53-1 and 53
-2 are driving beam portions 54a-1 to 54a-4, 54b-
Due to the spring action of 1 to 54b-1, the vibration frequency f₀And X
Synchronizes in the axial direction and oscillates with the same amplitude
Should be. This vibration is caused by the detection beam 52-1.
To the vibrator 51 through .about.52-4.
51 should vibrate only in the X-axis direction. Accordingly
And the Y-axis of the vibrator 51 taken out from the output terminal OUT.
The signal indicating the magnitude of the vibration in the direction should be "0".
You.

In this case, the high-frequency oscillator 72, the phase inversion circuit 72a, and the drive monitoring electrodes 58-1 to 58-
4, the signal E ₂ · E representing the vibration component in the X-axis direction
_0x · sin (2πf ₀ t) · sin (2πf ₂ t) is supplied to the drive circuit 80 via the terminal electrode 63b and the charge amplifier 73. Then, the demodulation circuit 81, the detection circuit 84, the phase shift circuit 82, and the gain control circuit 83 constituting the drive circuit 80 are connected to the input signal E _0x sin (2) of the phase shift circuit 82 and the gain control circuit 83.
πf ₀ t), that is, the vibration component in the X-axis direction from the terminal electrode 63b acts so as to be always constant over time, so that the vibrator 51 always vibrates with a constant amplitude in the X-axis direction.

On the other hand, variations in processing of each part of the angular velocity detecting element, particularly, the connecting parts 53-1 and 53-2, the driving beams 54a-1 to 54a-4, 54b-1 to 54b-4, and the driving Electrodes 57-1 to 57-4 and detection beam 52-1
Due to processing variations such as 52-4, the connecting portion 53-
If the 1,53-2 is not evenly driven in the X axis direction, the two DC voltage signal E _T, even equal E _B, the difference in the driving force of the connecting portion 53-1 and 53-2 occur Therefore, when a rotational motion is applied to the vibrator 51 and the center of the rotational motion is displaced from the vibrator center, the vibrator 51 generates vibration in the Y-axis direction. Here, paying attention to the driving force F1, F2 to the connecting portion 53-1 and 53-2, the driving force F1, the drive voltage signal _{E T + E 0x 'sin (} 2πf 0 t), E T -E 0x 'sin (2
πf ₀ t), where K is a proportional constant,
It is represented by

[0083]

F1 = K · {(E _T + E _0x 'sin (2πf ₀ t)) ² − (E _T −E _0x ' sin (2πf ₀ t)) ² } = 4 · K · E _T · E _0x 'sin (2πf ₀ t) The driving force F2 is equal to the driving voltage signal E _B + E _0x ' sin
(2πf ₀ t), E _B −E _0x 'sin (2πf ₀ t), and is expressed by the following equation 3.

[0084]

F1 = K · {(E _B + E _0x 'sin (2πf ₀ t)) ² − (E _B −E _0x ' sin (2πf ₀ t)) ² } = 4 · K · E _B · E _0x 'sin (2πf ₀ t) these numbers 2, as can be understood from Equation 3, by changing the magnitude of the DC voltage signal E _B outputted from the variable voltage source circuit 85a, connecting portion 53-1, The magnitude of both driving forces with respect to 53-2 can be adjusted. Therefore, the vibration component in the Y-axis direction of the vibrator 51 and the connecting portions 53-1 and 53-2 can be minimized.

Next, the DC variable power supply circuits 74-1 to 74-
4 will be described. The connecting part 53-
Oscillator 5 generated due to a difference in driving force between 1, 53-2
In one rotation movement, the detection beam portions 52-1 to 52-4
Are equal, the center of rotation is substantially equal to the center of the vibrator, and the vibration component in the Y-axis direction is zero. But,
If there is a difference in the spring constant of each beam due to processing variations of the detection beam portions 52-1 to 52-4, and the center of the rotational motion of the vibrator 51 around the Z axis is shifted, A vibration component in the Y-axis direction due to the vibration in the X-axis direction appears. Therefore, the DC variable power supply circuits 74-1 to 74-4 are adjusted so that the signal output from the output terminal OUT becomes zero when the vibrator 51 is vibrated in the X-axis direction in the state of the angular velocity “0”. By doing so, it is possible to minimize the displacement of the center of the rotational movement of the vibrator 51 about the Z axis.

Next, the operation of detecting the angular velocity around the Z-axis using the angular velocity detecting device that has been adjusted will be described. First, the angular velocity detector is fixed to an object such as a vehicle whose angular velocity is to be detected, and the electric circuit device is operated as described above. In this state, when an angular velocity acts around the Z axis, the vibrator 51 starts to vibrate in the Y axis direction with an amplitude proportional to the angular velocity due to Coriolis force.

In this case, the capacitance of the detection electrodes 61-1 to 61-4 changes according to the vibration of the vibrator 51 in the Y-axis direction. The change in the capacitance is determined by the detection signals E ₁ sin (2πf ₁ t) and E ₁ sin (2πf ₁ ) output from the high-frequency oscillator 71 and the phase inversion circuit 71a.
t + π) = − E ₁ sin (2πf ₁ tπ) modulated signal, that is, E ₁ · E _0y · sin (2πf ₀ t) · sin (2πf ₁ t)
And appears on the terminal electrode 63b, and is output to the output circuit 90 via the charge amplifier 73. The output circuit 90 outputs a signal E _0y representing the magnitude of the vibration of the vibrator 51 in the Y-axis direction from the output terminal OUT by the operation of the demodulation circuit 91, the detection circuit 92, and the amplifier 93. And this Y
Since the magnitude of the vibration in the axial direction is proportional to the angular velocity around the Z axis, the same angular velocity is detected.

As a result of detecting the angular velocity in this manner,
As described above, even if there is processing variation in each part of the angular velocity detecting element, the driving circuit 80 and the DC variable power supply circuit 74-
The vibrations in the X-axis direction of the vibrator 51 are accurately and stably secured by 1 to 74-4, and the center of rotation of the vibrator 51 about the Z-axis is also accurately adjusted. Is also detected with high accuracy.

In the third embodiment, the leakage vibration control circuit 33a (FIG. 3) as in the first embodiment is used.
, And after the angular velocity detecting device is mounted on a vehicle or the like, the DC variable power supply circuit 7
By controlling 4-1 to 74-4, the detection beam portions 52-1 to 5-5 are controlled.
The spring constant of 2-4 may be automatically adjusted when the vehicle stops.

Also, in the third embodiment, as in the first embodiment, the detection beams 52-1 to 52-4 are used.
Can be variously changed.

D. Other Modifications In the first and second embodiments, the driving beam 14
a-1 to 14a-4, 14b-1 to 14b-4, 14c
Adjustment electrodes 25-1 to 25-4 are provided on -1 to 14c-4 (drive beams 14d-1 to 14d-4, 14e-1 to 14e-4 in the second embodiment), respectively. DC variable power supply circuits 33b-1 to 33b-4 are provided corresponding to the adjustment electrodes 25-1 to 25-4, respectively.
Each drive beam 14a-1 to 14a-4, 14b-1 to 1
4b-4, 14c-1 to 14c-4 (in the second embodiment, the drive beams 14d-1 to 14d-4, 14e-1).
To 14e-4) can be changed independently of each other. However, the adjustment electrodes 25-1 to 25-25
-4 or a part of the DC variable power supply circuits 33b-1 to 33b-4 is omitted or shared so that the driving beam 1
4a-1 to 14a-4, 14b-1 to 14b-4, 14
c-1 to 14c-4 (drive beams 14d-1 to 14d-4, 14e-1 to 14e-4 in the second embodiment)
Only a part of the spring constant may be changed with respect to the others.

In the third embodiment, the adjustment electrode 62-1 is provided to the detection beam portions 52-1 to 52-4.
To 62-4, and each adjustment electrode 6
DC variable power supply circuit 74-1 corresponding to 2-1 to 62-4
To 74-4 are provided, respectively, and each detection beam part 52-1 to 74-4 is provided.
All the spring constants of 52-4 can be independently changed. However, by omitting or sharing a part of the adjustment electrodes 62-1 to 62-4 or the DC variable power supply circuits 74-1 to 74-4, the detection beam portions 52-1 to 5-4 can be used.
Only a part of the spring constant of 2-4 may be made changeable relative to the others.

In the first and second embodiments, the spring constants of the detection beams 12-1 to 12-4 may be changed by the same adjustment electrode as in the third embodiment. In the third embodiment, a driving beam 54a-1 is used.
The spring constants of ｂ54a-4 and 54b-1 変 更 54b-4 may be changeable by adjusting electrodes similar to those of the first and second embodiments.

In the first to third embodiments,
Changing the spring constant by the adjusting electrode also means changing the resonance frequency of the vibrator, and the change in the resonance frequency may be positively used. For example,
It may be used for changing and adjusting the resonance frequency of the vibrator in the X-axis direction and the Y-axis direction.

In the first to third embodiments, single crystal silicon is used as a material for the angular velocity detecting element. However, polycrystalline silicon may be used instead of single crystal silicon. Further, the substrate, various components, and the like may be formed using a metal material, a piezoelectric material, or the like instead of silicon.

Further, in the first to third embodiments, the present invention is applied to the angular velocity detecting device.
According to the present invention, a mass body (vibrator) suspended above a substrate upper surface is extended by a plurality of beams which are extended above the substrate upper surface and connected at one end to the mass body and fixed at the other end to the substrate. Any physical quantity detection device that is displaceably supported on a substrate and detects a physical quantity according to the displacement of the mass body can be widely applied to an acceleration sensor, a pressure sensor, a gas sensor, a force sensor, and the like. The acceleration sensor, for example, detects acceleration in accordance with the amount of displacement of the mass body in accordance with the acceleration acting on the substrate, also in this case, by adjusting the spring constant of the beam by the adjustment electrode as described above, High-precision displacement of the mass body according to the acceleration can be obtained. Further, the pressure sensor and the gas sensor use, for example, a method in which the mass body is vibrated, and the vibration of the mass body is suppressed by the pressure and the gas, and the amplitude of the vibration is reduced. By adjusting the spring constant by the adjusting electrode as described above, the mass body can be vibrated with high accuracy. The force sensor, when the mass is vibrated and a force is applied to the beam,
It utilizes the fact that the spring constant of the beam changes and the vibration frequency of the mass changes, and also in this case, the mass is adjusted by adjusting the spring constant of the beam with the adjustment electrode as described above. It becomes possible to vibrate accurately.

[Brief description of the drawings]

FIG. 1 is a plan view of an angular velocity detecting element according to a first embodiment of the present invention.

2A is a sectional view taken along line AA of FIG. 1, and FIGS. 2B to 2D are views taken along line BB to DD of FIG. It is an end elevation.

FIG. 3 is a block diagram of an electric circuit device for detecting an angular velocity using the angular velocity detecting element according to the first embodiment.

FIG. 4 is an explanatory diagram for describing an operation of adjusting a spring constant of a driving beam by the adjustment electrode of FIG. 1;

FIGS. 5A to 5C are plan views according to various modifications of the adjustment electrode of FIG. 1;

FIG. 6 is a plan view of an angular velocity detecting element according to a second embodiment of the present invention.

FIG. 7 is a plan view of an angular velocity detecting element according to a third embodiment of the present invention.

FIG. 8 is a block diagram of a first electric circuit device for detecting an angular velocity using the angular velocity detecting element according to the third embodiment.

[Explanation of symbols]

10: substrate, 11, 11 ': vibrator, 12-1 to 12-
4 ... Detection beam part, 14a-1 to 14a-4, 14b-1
~ 14b-4, 14c-1 ~ 14c-4, 14d-1 ~
14d-4, 14e-1 to 14e-4: driving beam, 1
6a-1 to 16a-4, 16b-1 to 16b-4, 16
-1 to 16-4 ... anchor, 17, 17-1, 17-2 ...
Driving electrodes, 18, 18-1, 18-2 ... Driving monitoring electrodes, 21, 21 ', 22, 22' ... Detecting electrodes, 2
3, 23 ', 24, 24' ... control electrodes, 25-1 and 25-2
5-4: electrode for adjustment, 33a: leakage vibration control circuit, 33
b-1 to 33b-4: DC variable power supply circuit, 51: vibrator, 52-1 to 52-4: beam for detection, 54a-1 to 54-5
4a-4, 54b-1 to 54b-4...
-1 to 56-4: anchor, 57-1 to 57-4: drive electrode, 58-1 to 58-4: drive monitor electrode, 61-
1 to 61-4: detection electrodes; 62-1 to 62-4: adjustment electrodes; 74-1 to 74-4: DC variable power supply circuits.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Motohiro Fujiyoshi 41-Cho, Yokomichi, Nagakute-machi, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory, Inc. (72) Inventor Tokuo Fujitsuka, Nagakute-machi, Nagakute-cho, Aichi-gun, Aichi Prefecture No. 41, Yokomichi, Toyota Central Research Institute, Inc. (72) Inventor Kentaro Mizuno, Chitomi, Ochi, Nagakute-cho, Aichi-gun, Aichi Prefecture, Japan No. 41, Toyota Central Research Institute, Inc. (72) Inventor Yoshiteru Omura Aichi Prefecture No. 41, Toyota Central R & D Laboratories Co., Ltd. (72) Inventor Hiroshi Nonomura 41, Ochi-Cham Chu Yokomichi, Nagakute-cho, Aichi County, Aichi-gun Reference) 2F105 BB04 BB15 CC04 CD03

Claims (8)

[Claims] A mass body suspended above an upper surface of a substrate;
A plurality of beams extending above the substrate and connected at one end to the mass body and having the other end fixed to the substrate upper surface, respectively, based on a displacement of the mass body with respect to the substrate. In a physical quantity detection device for detecting a physical quantity, for at least one of the plurality of beams, a beam-side electrode finger connected to an intermediate portion of the at least one beam and a substrate connected to an upper surface of the substrate A physical quantity detection device characterized in that an adjustment electrode for changing a spring constant of at least one beam is provided by opposing side electrode fingers to each other. 2. The physical quantity according to claim 1, wherein both the beam-side electrode fingers and the substrate-side electrode fingers extend in the same direction as the direction in which the beam connected to the beam-side electrode fingers extends. Detection device. 3. The physical quantity detection device according to claim 1, wherein a DC voltage is applied between the beam-side electrode finger and the substrate-side electrode finger of the adjustment electrode, and the applied voltage is changed. A physical quantity detection device provided with a variable voltage source circuit that enables the physical quantity detection. 4. A mass body suspended above an upper surface of a substrate,
A plurality of beams extending from the top surface of the substrate, each end connected to the mass body, and the other end fixed to the top surface of the substrate, and the mass body in the X-axis direction with respect to the substrate. A driving electrode for vibrating; and a detecting electrode for detecting vibration of the mass body with respect to the substrate in a Y-axis direction orthogonal to the X-axis direction. An angular velocity detecting device for detecting an angular velocity around a Z-axis orthogonal to both Y-axes, wherein at least one of the plurality of beams has a beam side connected to an intermediate portion of the at least one beam. An angular velocity detecting device, wherein an electrode finger and a substrate-side electrode finger connected to the upper surface of the substrate are opposed to each other, and an adjusting electrode for changing a spring constant of the at least one beam is provided. 5. The angular velocity according to claim 4, wherein both the beam-side electrode fingers and the substrate-side electrode fingers extend in the same direction as the direction in which the beam connected to the beam-side electrode fingers extends. Detection device. 6. The angular velocity detecting device according to claim 4, wherein both the X and Y axes are axes parallel to the upper surface of the substrate, and the plurality of beams are connected to the Y beam.
The driving beam portion extending in the axial direction and the detection beam portion extending in the X-axis direction are connected to each other, and the adjustment electrode is provided on the driving beam portion. Angular velocity detecting device. 7. The angular velocity detecting device according to claim 4, wherein both the X and Y axes are axes parallel to the upper surface of the substrate, and the plurality of beams are connected to the Y beam.
The driving beam portion extending in the axial direction and the detection beam portion extending in the X-axis direction are connected to each other and configured, and the adjustment electrode is provided on the detection beam portion. Angular velocity detecting device. 8. The angular velocity detecting device according to claim 4, wherein a DC voltage is applied between a beam electrode finger and a substrate electrode finger of said adjusting electrode. And a variable voltage source circuit capable of changing the applied voltage.