JPH1123279A - Electric-field compensation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electric-field compensation device in which an electrostatic support force by a capacitor is enhanced and in which the sensitivity of a change in a capacitance with reference to the displacement in the X-axis direction of a vibration part is enhanced by suppressing the electric field at the end part of the capacitor which is constituted of an electrode part in the vibration part in a tuning-fork part and of an electrostatic support electrode by a cover member. SOLUTION: Electrodes 401A-1, 401A-2, etc., and auxiliary electrodes 411A-1, 411A-2, 411A-3, etc., as electric-field compensation mechanisms are installed at the inside of cover members 40A, 40B. Then, potentials of auxiliary electrodes 411A-1 to 412B-3 are made identical to potentials of electrode parts 501A-1 to 502B-2 in vibration parts 501, 502. Thereby, an electric field which is generated at the end part of a capacitor which is composed of electrode parts 501A-1 to 502B-2 in the vibration parts 501, 502 in tuning-fork parts 50-1, 50-2 and of electrodes 401A-1 to 402B-2 by cover members 40A, 40B is suppressed. An electrostatic support force by the capacitor and the sensitivity of a change in a capacitance with reference to the displacement in the X-axis direction of the vibration parts 501, 502 are enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device configured to obtain a driving force by an electrostatic force of a capacitor constituted by electrodes facing each other, and more particularly to an electric field compensation mechanism for improving the electrostatic force by the capacitor. .

[0002] The present invention relates to a vibrating gyro device having an electric field compensation mechanism and a linear stepping electrostatic microactuator device.

[0003]

2. Description of the Related Art When a voltage is applied between two electrodes facing each other, a capacitor is formed, and an electrostatic force or an electrostatic attraction is generated between the two. A device that uses this electrostatic force or electrostatic attraction force as a driving force is known. For example, an acceleration detection type gyro device that supports and drives a gyro rotor in a floating manner by electrostatic force, a vibration type gyro device that vibrates a vibrating portion of a tuning fork by electrostatic force, and a linear stepping electrostatic force microactuator that drives a movable portion by electrostatic force Device.

In these devices, each electrode is formed in a number of elongated strips parallel to each other. These elongated strips extend in a linear or curved manner. These two corresponding electrodes are arranged offset from each other, and the overlapping portion of the two electrodes constitutes a capacitor. By applying a voltage between the two electrodes, a driving force is generated to move the electrodes laterally.

An example of a conventional vibration type gyro device will be described with reference to FIGS. An example of this vibrating gyro device was disclosed by the same applicant as the present applicant on January 1, 1996.
Japanese Patent Application No. 8-5177 filed on the 6th (T95001)
43), see the same application for details.

FIG. 9 shows the appearance of a conventional vibration type gyro device. This vibration type gyro device has two cover members 1
0A and 10B and the substrate 20 interposed therebetween. The cover members 10A and 10B and the substrate 20 are formed of thin plate members, and the vibrating gyro device has a thin rectangular parallelepiped as a whole.

As shown in the figure, an X axis is taken in the longitudinal direction of the vibrating gyro device, a Y axis is taken in the thickness direction, and a Z axis is taken in the width direction. The origin O of the coordinate axes is set at the center position of the rectangular parallelepiped. Main surface is X
It is parallel to the Z plane.

The substrate 20 has a tuning fork, which comprises a pair of tuning fork portions 20-1 and 20-2 (only one is shown). The two tuning fork portions 20-1 and 20-2 are arranged along the XZ plane and symmetrically with respect to the Z axis. Therefore, in this vibrating gyro device, the Z axis is the tuning fork axis. Electrodes (only 100A-1 and 100A-2 are partially shown) are formed on the inner surfaces of the cover members 10A and 10B, respectively. The dimensions and materials of each part will be described later.

The structure of the substrate 20 will be described with reference to FIGS. FIG. 10 shows a cross-sectional configuration along the line 10-10 in FIG. 9, and FIG.
FIG. 11 is a cross-sectional view taken along a line 11-11 in FIG. 10 and shows a planar configuration of the substrate 20. The substrate 20 can be oriented with respect to the Z axis or Y
It has a shape that is symmetrical with respect to the Z plane. Rectangular shallow recesses 20A are formed on both sides of the substrate 20, and such recesses 20A are formed.
A pair of tuning fork portions 20-1 and 20-2 are formed on the bottom surface of A. As shown, an E-shaped through-hole 20a and a pair of U-shaped through-holes 20b, 20c are formed on the bottom surface of the recess 20A.
Is formed, whereby the two tuning fork portions 20-
1, 20-2 are formed.

FIG. 12 shows the structure of one tuning fork portion 20-1. The structure of the two tuning fork portions 20-1 and 20-2 is the same, and the description of the structure of the other tuning fork portion 20-2 is omitted. The first tuning fork portion 20-1 has a central axis OO. Further, for convenience of explanation, in this specification, the central axis O
A plane including -O and parallel to the YZ plane is referred to as a central axis plane OO.

The first tuning fork portion 20-1 has a symmetrical shape with respect to a central axis or a central axis plane OO. The tuning fork portion 20-1 has U-shaped support portions 21a, 21b, 21c and a vibrating portion 201 disposed therebetween. The U-shaped supporting portions 21a, 21b, 21c are connected to the legs 21a, 21b on both sides parallel to each other and the connecting portion 21c connecting the both.
And the vibration unit 201 is connected to the connection unit 21c.

In this way, the vibrating part 201 has two legs 21
Thus, the tuning fork portion 20-1 has a cantilever support structure.

Next, the shape of the vibrating portion 201 of the first tuning fork portion 20-1 will be described in detail with reference to FIGS. 10 and 11 again. As shown in FIG. 11, a plurality of elongated grooves 201a-1 are provided on the upper and lower surfaces of the first vibrating portion 201, respectively.
201a-2 and 201b-1, 201b-2 are formed. The elongated projections formed on both sides of these elongated grooves constitute electrode portions.

As shown in FIG. 10, the first vibrating section 201
On the upper surface of the first vibrating portion 201 are formed elongated electrode portions 201A-1 and 201A-2. On the lower surface of the first vibrating portion 201, elongated electrode portions 201B-1 and 201B-2 are formed. As shown in the figure, these electrode portions 201A-1 and 201A-2 and the electrode portions 201B-1 and 201B-2 are connected to a central axis O-.
It is arranged symmetrically on both sides of the central axis plane in parallel with O.

The same applies to the structure of the vibrating portion 202 of the second tuning fork portion 20-2. That is, elongated electrode portions 202A-1 and 202A-2 are formed on the upper surface of the second vibrating portion 202, and elongated electrode portions 202B-
1, 202B-2. These electrode parts 2
02A-1, 202A-2 and electrode portions 202B-1, 2
02B-2 is arranged symmetrically on both sides of the central axis plane in parallel with the central axis line OO.

The structure of the cover member 10B will be described with reference to FIG. The structure of the two cover members 10A and 10B is the same, and the description of the structure of the other cover member 10A is omitted. An elongated electrode 1 is provided on the inner surface of the cover member 10B.
01B-1, 101B-2 and 102B-1, 102B
-2 is formed.

The first electrodes 101B-1 and 101B-2 are arranged symmetrically on both sides of the central axis plane OO as shown in the figure, and the second electrodes 102B-1 and 102B-2 are also arranged on the central axis. It is symmetrically arranged on both sides of the plane OO. As shown in FIG. 10, the first electrodes 101A-1, 101A-2 and the second electrodes 102A-1, 102A-2 are similarly arranged on the inner surface of the other cover member 10A.

Next, with reference to FIGS. 10, 13 and 14, electrode portions 201A-1, 201A-2, 201B-1, and 20B formed on two tuning fork portions 20-1 and 20-2.
1B-2 and 202A-1, 202A-2, 202B-
1, 102B-2 and the electrodes 101A-1, 101A-2, 1 disposed on the inner surfaces of the two cover members 10A, 10B.
01B-1, 101B-2 and 102A-1, 102A
-2, 102B-1, and 102B-2 will be described.

Here, the electrode portions 201A-1, 201A-2, 201B-1, 201 of the first tuning fork portion 20-1 are provided.
B-2 and first electrodes 101A-1, 101A-2, 101 arranged on inner surfaces of two cover members 10A, 10B.
The relative positional relationship between B-1 and 101B-2 will be described.

The upper electrode portion 2 of the first tuning fork portion 20-1
01A-1 and 201A-2 correspond to the electrodes 101A-1 and 101A-2 arranged on the inner surface of the upper cover member 10A. Lower electrode portion 2 of first tuning fork portion 20-1
01B-1 and 201B-2 correspond to the electrodes 101B-1 and 101B-2 arranged on the inner surface of the lower cover member 10B. This is indicated by the dashed line in FIG.

As described above, the electrode portions 201A-1, 201A-2 and 201B-1 of the first tuning fork portion 20-1
201B-2 are arranged symmetrically on both sides with respect to the center axis plane, and the electrodes 101A-1, 1A of the cover members 10A, 10B.
01A-2 and 101B-1, 101B-2 are symmetrically arranged on both sides with respect to the central axis plane.

Therefore, the outer electrode portions 201A-1 and 201B-1 of the first tuning fork portion 20-1 and the cover member 10A,
The electrodes 101A-1 and 101B-1 on the outside of the first tuning fork 20B correspond to the electrodes 101A-1 and 101B-1 on the outside of the first tuning fork portion 20-1.
01A-2, 201B-2 and cover members 10A, 10B
Correspond to the inner electrodes 101A-2 and 101B-2, respectively.

As shown in FIGS. 10 and 13, the electrode portions 201A-2 to 202B-of the tuning fork portions 20-1 and 20-2 are provided.
2 and electrodes 101A-1 to 101-1 of cover members 10A and 10B
Each of 02B-2 includes a number of elongated strips, and the width and pitch of each of these strips in the X-axis direction are all the same.

For example, each of the strips constituting the electrode portions 201A-1 and 201B-1 outside the first tuning fork portion 20-1 and the electrode 101 outside the cover members 10A and 10B.
Each of the strips constituting A-1 and 101B-1 is arranged at the same pitch with respect to the central axis plane. Similarly,
An electrode portion 201A-2 inside the first tuning fork portion 20-1;
Each of the belt-shaped parts and cover member 1 constituting 201B-2
Electrodes 101A-2 and 101B-2 inside 0A and 10B
Are arranged at the same pitch with respect to the central axis plane.

The first of each of the cover members 10A and 10B
Electrodes 101A-1, 101A-2, 101B-1, 1
01B-2 is the electrode section 201A-1, 201A-2 and 201B-1, 20B of the corresponding first tuning fork portion 20-1.
With respect to 1B-2, they are arranged so as to be deviated outward with respect to the central axis plane OO. Cover members 10A, 10
B, the second electrodes 102A-1, 102A-2,
102B-1 and 102B-2 are the electrode portions 202A-1, 202A-2 and 2 of the corresponding second tuning fork portion 20-2.
With respect to 02B-1 and 202B-2, they are arranged to be deviated outward with respect to the central axis plane OO.

A description will be given with reference to FIG. In FIG.
An electrode portion 201A-1 outside the first tuning fork portion 20-1;
Outer electrode 10 out of the first electrodes of cover members 10A and 10B corresponding to the belt-shaped portion constituting 201B-1
1A-1 and 1B-1 show strip-shaped portions. The pitch p of the strip in the X-axis direction is twice the width t of the strip in the X-axis direction, that is, p = 2t. The electrodes 101A-1 and 101 of the cover members 10A and 10B with respect to the electrode portions 201A-1 and 201B-1 of the first tuning fork portion 20-1.
The deviation Δx in the X-axis direction of B-1 is half of the width t of the strip,
That is, Δx = t / 2.

[0027]

## EQU1 ## p = 2tΔx = t / 2

In the above example, the cover members 10A, 10A,
0B of the first electrodes 101A-1 and 101A-
2, 101B-1 and 101B-2 respectively correspond to the central axis plane OO with respect to the corresponding electrode portions 201A-1, 201A-2 and 201B-1 and 201B-2 of the first tuning fork portion 20-1. Although it is arranged to be biased outward with respect to,
It may be arranged biased inward. In such a case, each of the second electrodes 102A-
1, 102A-2, 102B-1, and 102B-2 correspond to the electrode portions 202A-1 of the corresponding second tuning fork portion 20-2.
With respect to 202A-2 and 202B-1, 202B-2, they are arranged to be deflected inward with respect to the central axis plane OO.

Next, the function of the conventional vibration type gyro device will be described with reference to FIG. This vibrating gyro device is
It is configured to detect an input angular velocity Ω around the Z axis. Vibrating section 201 of two tuning fork portions 20-1 and 20-2,
202 are vibrated so as to be displaced in the opposite directions ± V along the X-axis direction on the XZ plane. When the input angular velocity Ω around the Z-axis vibration gyro device acts, Coriolis force ± F _C in the Y-axis direction is generated in the vibration portion 201, 202 of the tuning fork portion 20-1 and 20-2.

[0030] Since the vibration direction of the two vibrating members 201 and 202 are opposite to each other, the Coriolis force F _C acting on the vibrating members 201 and 202 are opposite to each other. Therefore, the two Coriolis forces F _C are couples. Two tuning fork portion by the Coriolis force F _C 20-1 and 20-2 are alternately vibrate along the Y-axis direction. The input angular velocity Ω is detected by detecting the displacement of the alternating vibration.

By appropriately selecting the mass of the vibrating portion 201 and the position of its center of gravity, the center axis OO of the vibrating portion 201 is always kept parallel to the Z-axis even if the supporting portions 21a and 21b are bent. That is, even if the center of gravity of the vibrating part 201 is displaced in the X-axis direction due to vibration, or displaced in the Y-axis direction due to Coriolis force, the vibrating part 201 is only linearly displaced in the X-axis direction or the Y-axis direction. OO is always kept parallel to the Z axis.

The center axis OO of the tuning fork portion 20-1 is always parallel to the tuning fork axis, that is, the Z axis.
Of each of the strips constituting the electrode portions 201A-1 to 201B-2 and two cover members 10A and 10A corresponding thereto.
Each of the strips constituting the B electrodes 101A-1 to 101B-2 is always parallel, and the interval δ between them is the same everywhere in each strip. Therefore, the electrostatic attraction generated between them can be obtained most efficiently.

Next, the dimensions and materials of each part of the conventional vibration type gyro device will be described. This vibration type gyro device has, for example, a width and a length of 10 mm or less or several mm to 1 mm.
0 mm, thickness may be 5 mm or less or 2-4 mm.

As shown in FIGS. 10, 11 and 12,
The vertical and horizontal widths of the vibrating portions 201 and 202 of the tuning fork portions 20-1 and 20-2 formed on the substrate 20 may be 2 to 4 mm and a thickness of 2 to 4 mm. Electrodes 201A-1, 201A-2, 201B- formed on vibrating parts 201, 202
1, 201B-2, 202A-1, 202A-2, 20
The width t in the X-axis direction of the belt-shaped part constituting 2B-1 and 202B-2 may be t = 10 to 20 μm.

For example, the width of the vibrating portion 201 of the first tuning fork portion 20-1 in the X-axis direction is 4 mm, and the center axis OO
, That is, the width of the outer electrode 201A-1 in the X-axis direction is 2.0 mm. This electrode 201
Assuming that the width t of the strips constituting A-1 is t = 10 μm and the pitch p is p = 20 μm, about 100 strips are included.

Similarly, the right half of the center axis OO of the vibrating portion 201 of the first tuning fork portion 20-1, that is, the inner electrode 2
01A-2, if the width t of the strip is t = 10 μm and the pitch p is p = 20 μm, about 10
Zero strips are included. Therefore, the first tuning fork portion 20
The -1 vibrating part 201 includes a total of about 200 belt-like parts on both sides of the central axis OO.

As shown in FIG. 11, each tuning fork portion 20-
1, 202 electrode portions 201A-1, 201A-2, 20
1B-1, 201B-2, 202A-1, 202A-
2, 202B-1 and 202B-2 are strip-shaped grooves 201a.
-1, 201a-2, 201b-1, 201b-2, 2
02a-1, 202a-2, 202b-1, 202b-
2 is formed. The width and pitch of these grooves are equal to the width t and pitch p of the electrode portion.

The electrodes 101A-1, 101A-2, 102A-1, formed on the inner surfaces of the cover members 10A, 10B,
102A-1, 101B-1, 101B-2, 102B
-1, 102B-2 are the electrode portions 201A-1, 201A- of the two tuning fork portions 20-1, 20-2 as described above.
2, 201B-1, 201B-2, 202A-1, 20
2A-2, 202B-1, and 202B-2. Therefore, for example, as shown in FIG.
101B-1 and 101B-2 have a width of 2.0 in the X-axis direction.
mm, the width t of the strips constituting it is t = 10 μm, and the pitch p is p = 20 μm, each includes about 100 strips, and thus includes a total of about 200 strips. .

Next, the electrode section 2 of the tuning fork portions 20-1 and 202
01A-1, 201A-2, 201B-1, 201B-
2, 202A-1, 202A-2, 202B-1, 20
2B-2 thickness and electrodes 1 of cover members 10A and 10B
01A-1, 101A-2, 102A-1, 102A-
1, 101B-1, 101B-2, 102B-1, 10
The thickness of 2B-2 will be described.

That is, the electrode portions 201A-1, 201A-2, 201B-1, and 201B of the tuning fork portions 20-1 and 202.
-2, 202A-1, 202A-2, 202B-1, 2
02B-2 has a band-like groove 201a-1, 201a.
-2, 201b-1, 201b-2, 202a-1, 2
02a-2, 202b-1, and 202b-2. The depth of this groove is at least larger than the width t of the strip.

The electrodes 1 of the cover members 10A and 10B
01A-1, 101A-2, 102A-1, 102A-
1, 101B-1, 101B-2, 102B-1, 10
2B-2, which will be described later, is made of a metal thin film, and thus may have a thickness of 1 μmm or less.

Finally, as shown in FIG.
0-1 and 202 of the electrode portions 201A-1, 201A-2,
201B-1, 201B-2, 202A-1, 202A
-2, 202B-1, and electrodes 101A-1 and 101A-2 of the cover members 10A and 10B corresponding to 202B-2,
102A-1, 102A-1, 101B-1, 101B
-2, the gap between 102B-1, 102B-2, ie,
The interval δ in the Y-axis direction is δ = 2 to 3 μm.

The cover members 10A and 10B are made of a suitable insulating material such as glass and ceramics, and are preferably made of transparent hard glass. Substrate 20 is made of a suitable conductive material such as a metal, and is preferably made of single crystal silicon (Si).

Next, a method of manufacturing the vibrating gyro device will be described. First, the cover members 10A and 10B are manufactured.
Two rectangular thin plates of insulating material, preferably hard glass
And a metal thin film electrode 101A on one side of each.
-1, 101A-2, 102A-1, 102A-1 and 101B-1, 101B-2, 102B-1, 102B
-2 is formed.

The electrodes are formed using a suitable metal thin film forming technique. Such metal thin film forming techniques include vapor deposition, ion plating, and photofabrication. The electrodes are preferably made of gold (Au). As shown in FIG. 13, the electrodes 101A-1, 101A-2, 102A
-1, 102A-1 and 101B-1, 101B-2,
The ends of 102B-1 and 102B-2 are terminals 101B ',
102B '. This terminal 101B ', 1
02B 'is formed simultaneously with the electrode.

The terminals 101 are provided on the cover members 10A and 10B.
Through holes are formed at positions where B 'and 102B' are arranged, and a metal thin film is formed on the inner surface thereof. Thus, the electrodes 101A-1 and 101A are connected by through-hole connection.
-2, 102A-1, 102A-1 and 101B-1,
Terminal 10 of 101B-2, 102B-1, 102B-2
1B 'and 102B' are electrically connected to an external electric circuit. In addition, the through hole is sealed by the filler.

Next, the substrate 20 is manufactured. Prepare a rectangular thin conductive material, preferably a single crystal silicon (Si) plate,
A rectangular shallow recess 20A is formed on both sides. This recess 2
As described with reference to FIG. 14, the depth of 0A corresponds to the electrode portions 201A-1 to 202B of the tuning fork portions 20-1 and 202.
-2 of electrodes 101 of cover members 10A and 10B corresponding to
A gap δ between A-1 to 102B-2 is defined. Therefore, the depth of the recess 20A may be 2-3 μm.

Next, two tuning fork portions 20-1 and 20-2 are formed on the bottom surface of the recess 20A. E-shaped hole 20a
And the two U-shaped holes 20b and 20c are formed so that the support portions 21 of the two tuning fork portions 20-1 and 20-2 are formed.
a, 21b, 21c and 22a, 22b, 22c and vibrating parts 201, 202 are formed.

Next, the vibrating portions 201 and 202 are
1A-1 to 202B-2 are formed. Such an electrode unit 20
1A-1 to 202B-2 are formed by forming a large number of strip-shaped parallel grooves 201a-1 to 202b-2.

A rectangular shallow concave portion 20A formed on both surfaces of the substrate 20, an E-shaped hole 20a formed at the bottom of the concave portion 20A, two U-shaped holes 20b and 20c, and vibrating portions 201 and 202 are formed. Strip-shaped parallel groove 201a
-1 to 202b-2 may be formed by a lithography technique using laser light, for example, etching using laser light.

The two cover members 10A and 10B and the substrate 2
When 0 is formed, the two are joined. The substrate 20 is sandwiched between the two cover members 10A and 10B. The frame-shaped surface around the recess 20A on both surfaces of the substrate 20 and the inner surfaces of the two cover members 10A and 10B are joined. Such bonding is preferably made by anodic bonding.

Thus, the two cover members 10A, 10B
And the substrate 20 are joined to form a closed space between the inner surfaces of the two cover members 10A and 10B. This closed space includes a rectangular shallow recess 20A formed on both sides of the substrate 20, an E-shaped hole 20a formed at the bottom of the recess 20A, two U-shaped holes 20b and 20c, and vibrating portions 201 and 202. Strip-shaped parallel groove 201 formed in
a-1 to 202b-2.

In this enclosed space, the two tuning fork portions 20
-1, 20-2 vibrating parts 201 and 202 vibrate. Therefore, this sealed space is maintained at a high vacuum. In order to generate a high vacuum in the enclosed space, two cover members 10A, 1A
The bonding operation between the OB and the substrate 20 may be performed in a high vacuum atmosphere. Of course, the joining operation may be performed in the air, and the closed space may be evacuated later by an appropriate method.

As shown in FIG. 11, the substrate 20 is preferably
A concave portion 20B is formed in the substrate. The recess 20B is formed at an appropriate position so as to communicate with the above-mentioned closed space. A getter member for maintaining a high vacuum in the closed space is arranged in the concave portion 20B.

The tuning fork portions 20-1 and 20-2 may be provided with stoppers for limiting the displacement of the vibrating portions 201 and 202. The vibration units 201 and 202 are basically displaced in the X-axis direction and the Y-axis direction. Therefore, the vibration parts 201, 2
02 is provided with a stopper for limiting the displacement in the X-axis direction and the displacement in the Y-axis direction.

A stopper for limiting the displacement of the vibrating portions 201 and 202 in the Y-axis direction will be described. Vibration unit 20
1, 202 of the electrode portions 201A-1 to 202B-2 and the cover members 10A, 10B of the electrodes 101A-1 to 102B-.
2 constitutes a capacitor. An electrostatic attractive force acts between such capacitors.

This electrostatic attraction force is proportional to the capacitance of the capacitor formed by the two, and is inversely proportional to the square of the gap δ. Accordingly, the electrode portions 201A-
1 to 202B-2 and electrodes 1 of cover members 10A and 10B
When 01A-1 to 102B-2 come into contact with each other and the gap δ becomes zero, the electrostatic attraction becomes infinite, and it becomes difficult to separate them. Therefore, a stopper in the Y-axis direction is provided so that the gap δ between the two does not become zero even when both approach.

The stoppers in the Y-axis direction are
It may be a thin film of an insulating material provided on at least one of the electrode portions 201A-1 to 202B-2 of the 02 and the electrodes 101A-1 to 102B-2 of the cover members 10A and 10B. For example, silicon oxide (SiO ₂ ) may be used as such an insulating material.

Similarly, the stopper in the X-axis direction is
1, 202 is provided to limit the displacement in the X-axis direction. Such stoppers in the X-axis direction are
May be formed by providing appropriate stoppers on both sides of the E-shaped through hole 20a. Accordingly, the vibration units 201 and 202 are prevented from vibrating at an amplitude larger than the preset maximum amplitude.

Referring to FIG. 15, a control loop of the vibrating gyro device will be described. The control system of this vibration gyro device has a detection / drive system and an angular velocity detection system. The detection / drive system includes a detection drive unit 51 and a control calculation unit 52,
The angular velocity detection system includes a detection drive unit 51 and an angular velocity calculation unit 53.

The detection drive unit 51 is provided with two cover members 10.
Electrodes 101A-1 and 101A formed on inner surfaces of A and 10B
1A-2, 102A-1, 102A-2 and 101B-
Four detection drive circuits 51-1, 51-2, 51- connected to 1, 101B-2, 102B-1, 102B-2.
3, 51-4.

The first detection drive circuit 51-1 is provided with the first electrodes 101A-1 and 101A-2 of the first cover member 10A.
And the second detection drive circuit 51-2 is connected to the second electrodes 102A-1 and 102A-2 of the first cover member 10A.
It is connected to the. The third detection drive circuit 51-3 is connected to the second
First electrodes 101B-1 and 101 of the cover member 10B of FIG.
B-2, and the fourth detection drive circuit 51-4 is connected to the second
Second electrodes 102B-1 and 102B of the cover member 10B
B-2.

[0063] The first detection driving circuit 51-1 AC voltage AC for displacement detection and the reference DC voltage DC ₀ and drive AC voltage V _X
0 , the first electrodes 101A-1, 101A-2
Control voltage DC ₀ + V _X + AC ₀ and DC ₀ −
Apply V _X -AC ₀ . Displacement detection AC voltage AC ₀ AC voltage of high frequency is used. For example, the frequency f _X of the drive AC voltage V _X may be a few kHz, the frequency f ₀ is the number 100KHz~ number 10 of the displacement detection AC voltage AC ₀
MHz.

The first detection drive circuit 51-1 has an X voltage signal V _XA1 for instructing displacement of the vibrating portion 201 of the first tuning fork portion 20-1 in the X axis direction and a Y voltage for instructing displacement in the Y axis direction. A voltage signal V _YA1 is generated. The same applies to the second, third, and fourth detection driving circuits 51-2, 51-3, and 51-4. The control operation unit 52 outputs the X voltage signal V _XA1 ,
V _{XA 2} , V _XB1 , V _XB2 are input and the displacement AC voltage signal V
Calculate _X. The angular velocity calculator 53 outputs the Y voltage signal V _YA1 ,
V _YA2 , V _YA1 , and V _YA2 are input to calculate the input angular velocity Ω.

An example of a conventional linear stepping electrostatic microactuator will be described with reference to FIG. The linear stepping electrostatic microactuator has two fixed portions 40A and 40B and a movable portion 50 disposed therebetween, and the movable portion 50 is separated from the fixed portions 40A and 40B by a predetermined distance. And is supported by a suitable support device (not shown) so that it can move linearly.

The fixing portions 40A and 40B are made of a non-conductive material, and have a width t _{1 in the} X-axis direction and a pitch p
₁ strip-shaped electrodes 41A, 42A, 43A and 41
B, 42B and 43B are formed, and the movable portion 50 is made of a conductive material. On both surfaces thereof, elongated strip-shaped electrode portions 51A and 52 having a width in the X-axis direction of t ₂ and a pitch of p ₂ are provided.
A, 53A and 51B, 52B, 53B are formed.

The electrodes 41A, 42A, 43A and 41B,
The width t _{1 in} the X-axis direction of each of the electrodes 42B and 43B is equal to the electrode portion 51A,
52A, 53A and 51B, 52B, is equal to the width t ₂ of the X-axis direction 53B, the electrodes 41A, 42A, 43A and 41B, 42B, the pitch p ₁ of the X-axis direction 43B, the electrode portions 51A, 52A, 53A And 51B, 52B, 53
Greater than the pitch p ₂ of the X-axis direction of the B.

[0068]

## EQU2 ## t ₁ = t ₂ p ₁ > p ₂

The fixing portions 40A and 40B are made of a non-conductive material, and the electrodes 41A, 42A, 43A and 41B,
2B and 43B may be made of a conductive material such as a metal thin film. The movable portion 50 is made of a conductive material, and the electrode portions 51A, 52A, 53A and 51B, 52B, 53
B may be configured as protrusions formed on both surfaces of the movable unit 50.

As shown in FIG. 16A, the fixing portions 40A, 4A
The voltage V is applied between the first electrodes 41A, 41B of the movable portion 50 and the electrode portions 51A, 52A, 53A and 51B, 52B, 53B of the movable portion 50. The other electrodes 42A, 42B and 43A, 43B of the fixing portions 40A, 40B are grounded. The first electrodes 41A and 41B of the fixed portions 40A and 40B and the first electrode portions 51A and 51B of the movable portion 50 attract each other due to electrostatic attraction, and they are overlapped.

Next, as shown in FIG.
A, 40B of the second electrodes 42A, 42B and the movable portion 50 of the electrode portions 51A, 52A, 53A and 51B, 52B, 52B, 5B.
Voltage V is applied during 3B. The other electrodes 41A, 41B and 43A, 43B of the fixing portions 40A, 40B are grounded. Second electrodes 42A, 42B of fixing portions 40A, 40B
And the second electrode portions 52A and 52B of the movable portion 50 attract by the electrostatic attraction force, and both overlap. Therefore, the movable part 50 moves in the X-axis direction.

Next, as shown in FIG.
A, 40B, the third electrodes 43A, 43B and the movable portions 50 of the electrode portions 51A, 52A, 53A and 51B, 52B, 52B, 5B.
Voltage V is applied during 3B. The other electrodes 41A, 41B and 42A, 42B of the fixing portions 40A, 40B are grounded. Third electrodes 43A, 43B of fixing portions 40A, 40B
And the third electrode portions 53A and 53B of the movable portion 50 are attracted by the electrostatic attraction force, and both overlap. Therefore, the movable part 50 further moves in the X-axis direction.

In this manner, the fixed part 40 is
By sequentially applying the voltage V to the electrodes A and 40B, the movable unit 50 moves in the X-axis direction. The movable section 50 moves in a stepwise manner at every pitch difference Δp = p ₁ −p ₂ .

[0074]

As described with reference to FIG. 14, the vibrating portion 2 of each of the tuning fork portions 20-1 and 20-2.
01 and 202 and the electrodes 101A-1 and 102B of the cover members 10A and 10B.
-2 forms a capacitor. Vibrating section 201,
The binding or restoring force of 202 is based on the electrostatic support generated by the capacitor. This vibrating part 201,
In order to generate the binding force or the restoring force of 202, that is, the electrostatic supporting force most efficiently, it was considered that the expression of Expression 1 needs to be satisfied as described above.

Therefore, the two tuning fork portions 20-1 and 20-
Electrode portions 201A-1 to 20 of vibrating portions 201 and 202
Band-shaped part and cover members 10A and 10B constituting 2B-2
The dimensions and shapes of the strips constituting the electrodes 101A-1 to 102B-2 are designed so that the equation 1 is satisfied.

However, it has been found that even with such a design, no electrostatic supporting force equivalent to the calculated value is actually generated. This is because in the above discussion, as shown in FIG. 14, the electrode portions 201A-1 to 201A-20 of the vibrating portions 201 and 202.
2B-2 strip and cover member 10A, 10B electrode 1
This is because it is assumed that a capacitor is formed by overlapping portions of the strips 01A-1 to 102B-2, and that a uniform electric field is generated only in the overlapping portions.

In practice, a uniform electric field is destroyed at the end of the overlapped portion, and the effect of the electric field generated at this end appears on the capacitor. The action of the electric field at the end of the capacitor reduces the electrostatic supporting force of the capacitor, reduces the sensitivity of the capacitance change to the displacement of the vibrating portions 201 and 202 in the X-axis direction,
It acts to reduce the restraining or restoring force on 2.

The same applies to the case of the linear stepping electrostatic microactuator described with reference to FIG. For example, as shown in FIG.
A, 40B of the second electrodes 42A, 42B and the movable portion 50 of the electrode portions 51A, 52A, 53A and 51B, 52B, 52B, 5B.
When the voltage V is applied during 3B, the fixed portions 40A, 40A
The B second electrodes 42A and 42B and the second electrode portions 52A and 52B of the movable section 50 constitute a capacitor, and both are attracted and overlap by the electrostatic attraction of the capacitor.
At this time, the actual value of the driving force for moving the movable section 50 in the X-axis direction becomes smaller than the theoretical value due to the electric field generated at the end of the capacitor.

In view of the above, the present invention provides a vibrating gyroscope of a type in which a vibrating portion is vibrated by an electrostatic supporting force and acceleration is detected by a Coriolis force acting on the vibrating portion. To suppress the electric field at the end of the capacitor constituted by the electrostatic support electrode of the cover member and improve the electrostatic support force of the capacitor and the sensitivity of the change in capacitance to displacement of the vibrating portion in the X-axis direction. With the goal.

In view of the above, the present invention provides a linear stepping electrostatic microactuator configured to drive a movable section by electrostatic support force between an electrode of a fixed section and an electrode of a movable section facing each other. It is an object of the present invention to suppress the electric field at an end of a capacitor formed by an electrode of a fixed part and an electrode of a movable part, and to improve a driving force for the movable part.

[0081]

According to the present invention, there is provided an electric field compensating device for controlling an electric field generated between a capacitor constituted by a plurality of elongated strip-shaped first and second electrodes parallel to each other. , Includes an auxiliary electrode disposed between the electrodes, the auxiliary electrode being maintained at the same potential as one of the electrodes. Thereby, the electric field at the end of the capacitor is suppressed, and the change of the capacitance of the capacitor with respect to the electrostatic force generated by the capacitor and the movement of the vibrating part is improved.

According to the present invention, the electric field compensating device further includes a groove formed between the electrodes, and further includes configuring the width of the electrode to be smaller than half the pitch of the electrode.

According to the present invention, a tuning fork having two vibrating portions disposed on both sides of a tuning fork shaft, a casing for accommodating the tuning fork, and a plurality of elongated strip-shaped electrode portions formed on both surfaces of the vibrating portion and parallel to each other are provided. A plurality of elongated strip-shaped electrodes formed on the inner surface of the casing corresponding to the electrode portion and parallel to each other, and driving the vibrating portion by electrostatic force generated between the electrode portion and the electrode, In a vibration type gyro device configured to detect an angular velocity Ω around a tuning fork axis by detecting a generated Coriolis force, an electric field compensating mechanism for controlling an electric field generated in an electrode portion and a capacitor formed by the electrode is provided. The electric field compensating mechanism is configured to improve the electrostatic force generated by the capacitor and the change in the capacitance of the capacitor with respect to the movement of the vibrating part.

In the vibration type gyro device according to the present invention, the electric field compensating mechanism includes the auxiliary electrode disposed between the electrodes, and the auxiliary electrode is maintained at the same potential as the electrode portion. The electric field compensation mechanism includes a groove formed between the electrodes. Further, the electric field compensation mechanism includes a configuration in which the width of the electrode is smaller than half the pitch and the width of the electrode portion is smaller than half the pitch.

According to the present invention, a number of elongated strip-shaped electrode portions provided on the movable portion and parallel to each other, a number of elongated strip-shaped electrodes provided on the fixed portion and parallel to each other, and a capacitor formed by the electrode portion and the electrode. In a microactuator device configured to drive a movable portion by electrostatic force, an electric field compensation mechanism for controlling an electric field generated in a capacitor formed by an electrode portion and an electrode is provided. It is configured to improve the change in the capacitance of the capacitor with respect to the generated electrostatic force and the movement of the vibrating part.

According to the present invention, in the micro-actuator device, the electric field compensation mechanism includes an auxiliary electrode disposed between the electrodes, and the auxiliary electrode is maintained at the same potential as the electrode section. The electric field compensation mechanism includes a groove formed between the electrodes. Further, the electric field compensation mechanism includes a configuration in which the width of the electrode is smaller than half the pitch and the width of the electrode portion is smaller than half the pitch.

[0087]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a vibratory gyro device according to the present invention will be described with reference to FIGS. In the vibration type gyro device of the present example, two cover members 40A and 40A are provided.
An electric field compensating mechanism for suppressing an electric field generated at the end of the capacitor formed by the B electrode and the electrode portion of the substrate 50 is provided. The vibration type gyro device of the present example is different from the conventional vibration type gyro device described with reference to FIGS. 9 to 15 in that an electric field compensation mechanism is provided, and other configurations are basically the same. May be the same as Hereinafter, an example of this electric field compensation mechanism will be described.

A first example of the vibrating gyro device according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the vibration type gyro device of the present example includes two cover members 40A and 40B and a substrate 50 sandwiched therebetween.
It has a thin rectangular parallelepiped as a whole. As shown in the figure, an X-axis in the longitudinal direction of the vibrating gyro device, a Y-axis in the
Take the Z axis in the width direction. The origin O of the coordinate axes is set at the center position of the rectangular parallelepiped. The main surface is parallel to the XZ plane.

Electrodes (only 401A-1 and 401A-2 are shown) are provided on the inner surfaces of the cover members 40A and 40B, respectively.
And auxiliary electrodes (only 411A-1 and 411A-2 are partially shown). This auxiliary electrode is the electric field compensation mechanism in this example.

Referring to FIG. 2 and FIG.
The auxiliary electrodes formed on A and 40B will be described. FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG.
FIG. 3 is a sectional view taken along line 3-3 of FIG. The two cover members 40A and 40B have the same structure, and FIG. 3 shows only one cover member 40B.

On the inner surface of the cover member 40B, electrodes 401B-1, 401B-2 and 402B-1,
402B-2 are formed. First electrode 401B-
1, 401B-2 are arranged symmetrically on both sides of the central axis plane OO as shown in the figure, and the second electrodes 402B-1 and
402B-2 is also arranged symmetrically on both sides of the central axis plane OO.

Electrodes 401B-1, 401B-2 and 40
2B-1 and 402B-2 are constituted by a large number of elongated strips parallel to each other. In the following, the term "electrode" will be used as appropriate to mean this strip.

The first auxiliary electrodes 411B-1 and 411B-2 are disposed between the first electrodes 401B-1 and 401B-2, and the second auxiliary electrodes 411B-1 and 411B-2 are disposed between the second electrodes 402B-1 and 402B-2. Auxiliary electrodes 412B-1 and 412B-2 are arranged. Note that third auxiliary electrodes 411B-3 and 412B-3 are arranged at the center of the first electrodes 401B-1 and 401B-2 and at the center of the second electrodes 402B-1 and 402B-2. I have.

First and second auxiliary electrodes 411B-1 and 411B-4
11B-2, 412B-1, 412B-2, 411B-
3, 412B-3, like the electrodes 401B-1, 401B-2 and 402B-1, 402B-2, includes a number of mutually parallel strips.

As shown in FIG. 1, the other cover member 40
Similarly, on the inner surface of A, the first electrodes 401A-1, 401A
1A-2 and second electrodes 402A-1 and 402A-2 are arranged. Further, the first electrodes 401A-1, 40A
1A-2, the first auxiliary electrodes 411A-1 and 411A
-2, and the second electrodes 402A-1, 402A-
2, the second auxiliary electrodes 412A-1 and 412A-2 are arranged. First electrodes 401A-1, 401A-
2 and the center of the second electrodes 402A-1 and 402A-2, the third auxiliary electrodes 411A-3 and 412A-
3 are arranged.

A description will be given with reference to FIG. FIG. 4 shows the first
Electrode part 50 outside the vibrating part 501 of the tuning fork part 50-1
1A-1, 501B-1 and corresponding cover member 4
0A, the outer electrode 401A of the first electrodes 40B-
1, 401B-1 and auxiliary electrodes 411A-1, 411B
-1. As shown in FIG. 2, the vibration units 501 and 502
The electrode portions 501A-1 to 502B-2 include a number of elongated strips parallel to each other. In the following, the term “electrode part”
It is used as appropriate to mean this strip. In addition, the term “auxiliary electrode” is used as appropriate to mean a strip included in the auxiliary electrode.

The widths t of the electrode portions 501A-1 and 501B-1 in the X-axis direction are constant, and are arranged at a predetermined pitch p in the X-axis direction. Also, the electrodes 401A-1 and 401B
The width t in the X-axis direction of −1 is constant, and is arranged at a predetermined pitch p in the X-axis direction. Electrode portions 501A-1 and 5
01B-1 in the X-axis direction and the electrodes 401A-1 and 401A
B-1 has the same width in the X-axis direction, and the electrode portion 501A-
1, 501B-1 in the X-axis direction and the electrode 401A-
1, 401B-1 have the same pitch in the X-axis direction.

The pitch p of the electrodes 401A-1 and 401B-1 in the X-axis direction is twice the width t in the X-axis direction, that is, p = 2t.
It is. Further, the electrode portion 5 outside the first tuning fork portion 50-1
Cover member 40A for 01A-1, 501B-1,
The amount of deviation Δx in the X-axis direction of the electrodes 401A-1 and 401B-1 outside the 40B is half the width t in the X-axis direction, that is, Δx
= T / 2. Therefore, the equation of Expression 1 is established.

The first and second auxiliary electrodes 411A-1 and 411A-4
11B-1 are electrodes 401A-1, 401B-1
It is located between. Two adjacent electrodes 401A-
The interval between 1,401B-1 is t. First and second
The auxiliary electrodes 411A-1,411B-1 of width t _C in the X-axis direction smaller than the electrode 401A-1,401B-1 in the X-axis direction width t, therefore, the clearance Δt is present therebetween.

[0100]

T> t _C t−t _C = 2Δt

Third auxiliary electrodes 411A-3, 411B-
3 and 412A-3, 412B-3, the width t _C ′ in the X-axis direction is the first and second auxiliary electrodes 411A-1, 411A-1
It is larger than the width t _{C in} the X-axis direction of 1B-1.

In the above example, the cover members 40A, 40A
0B, the first electrodes 401A-1 and 401A-
2, 401B-1 and 401B-2 respectively correspond to the central axis plane OO with respect to the electrode portions 501A-1, 501A-2 and 501B-1, 501B-2 of the corresponding first tuning fork portion 50-1. Although it is arranged to be biased outward with respect to,
It may be arranged biased inward. In such a case, each of the second electrodes 402A-
1, 402A-2, 402B-1, and 402B-2 correspond to the electrode portions 502A-1 and 502A-1 of the corresponding second tuning fork portion 50-2.
With respect to 502A-2 and 502B-1, 502B-2, they are arranged to be deviated inwardly with respect to the central axis plane OO.

Auxiliary electrodes 411A-1, 411B-1, 4
11A-2, 411B-2, 412A-1, 412B-
1, 412A-2, 412B-2, 411A-3, 41
1B-3 and 412A-3, 412B-3 and the terminals 411A ', 411B' connected thereto (only one terminal 411B 'is shown in FIG. 3) are made of a conductive material, and the cover members 40A, 40B It may be manufactured by the same method and simultaneously with the electrodes.

For the production of the electrodes and the auxiliary electrodes of the cover members 40A and 40B and the terminals connected thereto, well-known metal thin film production techniques such as vapor deposition, ion plating, and photofabrication may be used.

Next, the auxiliary electrodes 411A-1 to 412B-
The operation of No. 3 will be described. The auxiliary electrodes are maintained at the same potential as the electrode portions 501A-1 to 502B-2 of the vibrating portions 501 and 502 of the corresponding tuning fork portions 50-1 and 50-2. As described with reference to FIG.
Normally, the potentials of the electrode portions 501A-1 to 502B-2 of the 502 are maintained at zero. Thus, the auxiliary electrode may be grounded to zero potential. Terminals 411A ', 411
B 'is grounded via through holes provided in the cover members 40A and 40B.

Thus, the auxiliary electrodes 411A-1 to 412B
-3 potential is applied to the electrode portions 501A of the vibrating portions 501 and 502.
By making the potential equal to 1 to 502B-2, 2
Vibrating parts 501, 50 of the two tuning fork parts 50-1, 50-2
2 electrode portions 501A-1 to 502B-2 and cover member 4
The electric field generated at the end of the capacitor constituted by the electrodes 401A-1 to 402B-2 of the electrodes 0A and 40B is suppressed, and the electrostatic supporting force and the vibrating portion 50 of this capacitor are suppressed.
The sensitivity of the change in capacitance with respect to the displacement of the X-axis direction 1,502 is improved.

Referring to FIG. 5, a second example of the vibrating gyro device according to the present invention will be described. FIG. 5 is a view similar to FIG. 4, in which the outer electrode portions 501A-1 and 501B-1 of the vibrating portion 501 of the first tuning fork portion 50-1 and the corresponding first outer electrodes of the first electrodes of the cover members 40A and 40B. Electrode 4
01A-1 and 401B-1 are shown.

According to this example, the cover members 40A, 40B
Grooves 421A- between the electrodes 401A-1 and 401B-1.
1, 421B-1 are formed. In this example, this groove is an electric field compensation mechanism. FIG. 9 shows a vibration type gyro device of this example.
15A to 40C of the cover members 40A and 40B as compared with the conventional vibration type gyro device described with reference to FIG.
-1, 401B-1 between the grooves 421A-1, 421B-
1 is provided, and other configurations may be the same.

The function of the grooves 421A-1 and 421B-1 will be described. By forming the grooves 421A-1 and 421B-1, the electrode portions 501 of the vibrating portions 501 and 502 are formed.
The electric field generated at the end of the capacitor constituted by A-1 to 502B-2 and the electrodes 401A-1 to 402B-2 of the cover members 40A and 40B is suppressed, and the electrostatic supporting force and the vibrating section 501 by this capacitor are suppressed. , 502, the sensitivity of the change in capacitance to the displacement in the X-axis direction is improved.

The depth δ _{t of the} grooves 421A-1 and 421B-1
Is set to a predetermined size so that the electric field generated at the end of the capacitor can be suppressed.
Electrode portions 501A-1, 501B-1 of tuning fork portion 50-1
May be sufficiently smaller than the depth of the groove between them (the height of the electrode portions 501A-1 and 501B-1). For example, the electrode unit 501A
In the case where the pitch p in the X direction of -1 and 501B-1 is 40 μm and the width t in the radial direction is 20 μm, the groove 421A-
Depth [delta] _t of 1,421B-1 may be a few [mu] m.

A third example of the vibrating gyro device according to the present invention will be described with reference to FIG. FIG. 6 is similar to FIGS. 4 and 5, except that the electrode portions 501A-1 and 501B-1 outside the vibrating portion 501 of the first tuning fork portion 50-1 and the first electrodes of the cover members 40A and 40B corresponding thereto. Outer electrodes 401A-1 and 401B-1 are shown.

According to this example, the cover members 40A, 40B
Of the electrodes 401A-1 and 401B-1 is larger than the width t of the electrodes 401A-1 and 401B-1 in the X-axis direction. Therefore, the following equation is established instead of the equation (1).

[0113]

P = t + s t <p / 2 <s Δx = t / 2

In this example, the electric field compensation mechanism has a structure in which the distance s between the electrodes 401A-1 and 401B-1 of the cover members 40A and 40B is larger than the width t in the X-axis direction. The pitch in the X-axis direction and the width in the X-axis direction of the electrode portions 501A-1 to 502B-2 of the vibrating portions 501 and 502 correspond to the electrodes 401A-1 to 402B-2 of the corresponding cover members 40A and 40B.
Are the same as the pitch in the X-axis direction and the width in the X-axis direction. Accordingly, the electrode portions 501A-1 to 501-5 of the vibrating portions 501 and 502
The pitch in the X-axis direction and the width in the X-axis direction of 02B-2 are also expressed by Formula 4.
The following relationship holds.

FIGS. 9 to 15 show the vibration type gyro device of this embodiment.
In comparison with the conventional vibratory gyro device described with reference to FIGS.
01B-1 and the electrode section 501A of the vibrating sections 501 and 502
-1 to 502B-2 are arranged so as to satisfy the relationship of Expression 4, and the other configurations may be the same.

According to this example, the electrode portions 501A-1 to 502B-2 of the vibrating portions 501 and 502 and the cover member 40A,
By configuring the electrodes 401A-1 to 402B-2 of the 40B so as to satisfy Equation 4, the electric field generated at the end of the capacitor constituted by both electrodes is suppressed,
The electrostatic supporting force of the capacitor and the vibrating sections 501, 5
02, the sensitivity of the change of the capacitance to the displacement in the X-axis direction is improved.

The examples of the three electric field compensation mechanisms described above can be combined with each other. For example, the compensation electrode of the first example can be added to the second example or the third example. Further, the second example and the third example can be combined. Of course, the three examples may be combined.

Referring to FIG. 7, the effects of the three electric field compensating mechanisms of the vibration type gyro device of the present embodiment will be described in comparison. FIG. 7 shows an example of three electric field compensating mechanisms when the vibrating parts 501 and 502 are changed in the X-axis direction.
01, 502 and the electrodes 401A-1 to 402B of the cover members 40A, 40B.
2 shows the change rate of the capacitance of the capacitor constituted by -2.

The graph F in FIG.
Electrode portions 501A-1 to 502B-2 and cover member 40
This is the change rate of the capacitance when the capacitor constituted by the electrodes 401A-1 and 402B-2 of A and 40B is ideal. The case where the capacitor is ideal is that the electrode portions 501A-1 to 501A-1 of the vibrating portions 501 and 502 are used.
502B-2 and electrodes 401 of cover members 40A and 40B
This is a case where an electric field is uniformly generated only in the portion where A-1 to 402B-2 overlap, and the electric field generated at the end of the capacitor can be ignored.

Graph A shows the rate of change of the capacitance of the capacitor in the case of the conventional vibrating gyro device, which is about 0.4 because no electric field compensation mechanism is provided. Graph B shows a third example of the electric field compensation mechanism of the vibration type gyro device of the present invention.
In the case of the example, graph C is a graph of the second example of the electric field compensation mechanism of the vibration type gyro device of the present invention, and graph D is a graph of the first example of the electric field compensation mechanism of the vibration type gyro device of the present invention E represents the rate of change of the capacitance of the capacitor when the first example and the third example of the electric field compensation mechanism of the vibration type gyro device of the present invention are combined.

According to the present invention, it can be seen that the first example of the electric field compensation mechanism, that is, the case where the compensation electrode is used, provides the best results. Also, it can be seen that a better result can be obtained by combining the first example of the electric field compensation mechanism with another example.

Referring to FIG. 8, an example of a linear stepping electrostatic microactuator according to the present invention will be described.
The linear stepping electrostatic microactuator of the present example is different from the conventional linear stepping electrostatic microactuator described with reference to FIG. 16 in that an electric field compensation mechanism is provided, and other configurations are the same. It may be.

As described above, the linear stepping electrostatic micro-actuator has two fixed portions 40A and 40B.
Fixed electrodes 41A, 42A, 43A and 41 attached to
B, 42B, 43B and movable electrodes 51A, 52A, 53A, and 51 mounted on the movable portion 50 disposed therebetween.
B, 52B, and 53B.

In the first example shown in FIG.
Compensation electrodes 61A, 62A, 63A and 61B, 62B between A, 42A, 43A and 41B, 42B, 43B,
63B are arranged. In the first example, the compensation electrodes 61A, 62A, 63A and 61B, 62B, 63B are electric field compensation mechanisms.

In the second example shown in FIG. 8B, the fixed electrode 41
Grooves 71A, 72A, 73A and 71B, 72B, 73B between A, 42A, 43A and 41B, 42B, 43B
Are formed. In the second example, the grooves 71A, 72
A, 73A and 71B, 72B, 73B are electric field compensation mechanisms.

A first example of the electric field compensation mechanism of the linear stepping electrostatic microactuator shown in FIG. 8A is shown in FIG.
Has the same configuration and operation as the first example of the electric field compensation mechanism of the vibration type gyro device described with reference to FIG. The second example of the electric field compensation mechanism of the linear stepping electrostatic microactuator shown in FIG. 8B has been described with reference to FIG.
It has the same configuration and operation as the second example of the electric field compensation mechanism of the vibration gyro device.

According to the present example, the electric field at the end of the capacitor formed by the fixed electrode and the movable electrode is suppressed, the electrostatic force generated by the capacitor is improved, and the driving for driving the movable portion in the X-axis direction is performed. Power is improved.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to these examples, and various modifications can be made within the scope of the invention described in the claims. It will be understood by those skilled in the art.

[0129]

According to the present invention, there is provided a vibrating gyro apparatus of the type in which a vibrating section is vibrated by an electrostatic supporting force.
There is an advantage that the sensitivity of the change in the capacitance to the displacement of the vibrating portion in the vibration direction and the electrostatic supporting force can be improved.

According to the present invention, in a vibration type gyro device of a type in which a vibrating portion is vibrated by an electrostatic supporting force, the sensitivity of the change in capacitance with respect to displacement of the vibrating portion in the vibration direction and the electrostatic supporting force are improved. Therefore, there is an advantage that the driving force for the vibrating portion can be increased.

According to the present invention, in a vibration type gyro device of a type in which a vibrating portion is vibrated by an electrostatic supporting force, the sensitivity of the change in capacitance to the displacement of the vibrating portion in the vibration direction can be improved by a relatively simple configuration. There is an advantage that the electrostatic supporting force can be improved.

According to the present invention, there is an advantage that the driving force for the movable portion can be improved with a simple configuration in the electrostatic microactuator device.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing the appearance of a vibration type gyro device according to the present invention.

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, showing a cross-sectional configuration of the vibration type gyro device according to the present invention.

FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2, showing an inner surface of a cover member of the vibration gyro device according to the present invention.

FIG. 4 is a diagram showing a first example of an electric field compensation mechanism provided in a capacitor of the vibration type gyro device according to the present invention.

FIG. 5 is a diagram showing a fifth example of the electric field compensation mechanism provided in the capacitor of the vibration type gyro device according to the present invention.

FIG. 6 is a diagram showing a third example of the electric field compensation mechanism provided in the capacitor of the vibration type gyro device according to the present invention.

FIG. 7 is a diagram showing the effects of three examples of the electric field compensation mechanism provided in the capacitor of the vibration type gyro device according to the present invention.

FIG. 8 is a diagram illustrating an example of a linear stepping electrostatic microactuator device according to the present invention.

FIG. 9 is a partially cutaway perspective view showing the appearance of a conventional vibration type gyro device.

FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 9, showing a cross-sectional configuration of the conventional vibration type gyro device.

FIG. 11 is a cross-sectional view of the structure of the tuning fork of the substrate of the conventional vibration type gyro device, taken along line 11-11 in FIGS. 9 and 10;

FIG. 12 is a partially cutaway view showing a structure of a tuning fork of a conventional vibration type gyro device.

FIG. 13 is a cross-sectional view showing an inner surface of a cover member of the conventional vibration type gyro device, taken along line 13-13 in FIG.

FIG. 14 is a diagram showing a relative position between an electrode portion of a tuning fork and an electrode of a cover member of a conventional vibration type gyro device.

FIG. 15 is a diagram illustrating an example of a control loop of a conventional vibration type gyro device.

FIG. 16 is a diagram showing an example of a conventional linear stepping electrostatic force microactuator device.

[Explanation of symbols]

10A, 10B Cover member 20 Substrate 20-1, 20-2 Tuning fork portion 20A Recess 20B Recess 20a, 20b, 20c Hole 21a, 21b, 21c, 22a, 22b, 22c Support member 40A, 40B Cover member, fixing portion 50 Substrate, Movable part 50-1, 50-2 Tuning fork part 50A Recess 50a, 50b, 50c Hole 51 Detection drive part 52 Control operation part 53 Angular velocity operation part 101A-1, 101A-2, 102A-1, 102A
-2 electrode 101B-1, 101B-2, 102B-1, 102B
-2 electrode 201, 202 vibrating part 201A-1, 201A-2, 202A-1, 202A
-2 electrode part 201B-1, 201B-2, 202B-1, 202B
-2 electrode part 201a-1, 201a-2, 202a-1, 202a
-2 groove 201b-1, 201b-2, 202b-1, 202b
-2 groove portions 401A-1, 401A-2, 402A-1, 402A
-2 electrode 401B-1, 401B-2, 402B-1, 402B
-2 electrode 411A-1, 411A-2, 411A-3, 412A
-1, 412A-2, 412A-3 Compensation electrode 411B-1, 411B-2, 411B-3, 412B
-1, 412B-2, 412B-3 Compensation electrodes 421A-1, 421A-2, 422A-1, 422A
-2 groove 421B-1, 421B-2, 422B-1, 422B
-2 groove 501, 502 vibrating part 501A-1, 501A-2, 502A-1, 502A
-2 electrode part 501B-1, 501B-2, 502B-1, 502B
-2 electrode part

Claims (11)

[Claims] 1. An electric field compensator for controlling an electric field generated between a capacitor formed by a plurality of elongated strip-shaped first and second electrodes parallel to each other, comprising:
An electric field compensator comprising an auxiliary electrode disposed between the electrodes, the auxiliary electrode being maintained at the same potential as one of the electrodes. 2. The electric field compensator according to claim 1, wherein
An electric field compensator comprising a groove formed between the electrodes. 3. The electric field compensator according to claim 1, further comprising a configuration in which the width of the electrode is smaller than half the pitch of the electrode. 4. A tuning fork having two vibrating portions disposed on both sides of a tuning fork shaft, a casing for accommodating the tuning fork, a plurality of elongated strip-shaped electrode portions formed on both surfaces of the vibrating portion and parallel to each other; A plurality of elongated strip-shaped electrodes formed on the inner surface of the casing corresponding to the electrode portion and parallel to each other, and driving the vibrating portion by electrostatic force generated between the electrode portion and the electrode; In a vibrating gyro device configured to detect an angular velocity Ω around the tuning fork axis by detecting a Coriolis force generated in a vibrating portion, in order to control an electric field generated in a capacitor formed by the electrode portion and the electrode. Electric field compensation mechanism is provided,
A vibratory gyro device, wherein the electric field compensating mechanism is configured to improve a change in electrostatic force generated by the capacitor and a change in capacitance of the capacitor with respect to movement of the vibrating section. 5. The vibrating gyro device according to claim 4, wherein the electric field compensation mechanism includes an auxiliary electrode disposed between the electrodes, and the auxiliary electrode is maintained at the same potential as the electrode section. A vibratory gyro device characterized by the above-mentioned. 6. The vibrating gyro device according to claim 4, wherein said electric field compensating mechanism includes a groove formed between said electrodes. 7. The vibrating gyro device according to claim 4, wherein the electric field compensation mechanism makes the width of the electrode smaller than half the pitch and makes the width of the electrode portion smaller than half the pitch. A vibrating gyro device characterized by comprising: 8. A plurality of elongated strip-shaped electrode portions provided on the movable portion and parallel to each other, a number of elongated strip-shaped electrodes provided on the fixed portion and parallel to each other, and a capacitor formed by the electrode portion and the electrode. In a micro-actuator device configured to drive the movable portion by electrostatic force, an electric field compensation mechanism for controlling an electric field generated in a capacitor formed by the electrode portion and the electrode is provided,
A microactuator device characterized in that the electric field compensation mechanism is configured to improve a change in electrostatic force generated by the capacitor and a change in capacitance of the capacitor with respect to movement of the vibrating portion. 9. The microactuator device according to claim 8, wherein the electric field compensation mechanism includes an auxiliary electrode disposed between the electrodes, and the auxiliary electrode is maintained at the same potential as the electrode portion. A microactuator device characterized by the following. 10. The microactuator device according to claim 8, wherein the electric field compensation mechanism includes a groove formed between the electrodes. 11. The micro-actuator device according to claim 8, 9 or 10, wherein the electric field compensating mechanism causes the width of the electrode to be smaller than half the pitch and the width of the electrode portion to be smaller than half the pitch. A microactuator device comprising configuring.