JP2001086775A - Oscillation actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an efficient oscillation actuator in which an oscillator can be locked surely and supported fixedly using a simple structure, without blocking oscillation thereof and an axially asymmetric in-plane oscillation can be generated in the intended direction. SOLUTION: An oscillation actuator generating a drive force by generating a radially symmetric elongation oscillation simultaneously with an axially asymmetric in-plane oscillation is provided with a cut 110b at a part, where an oscillator 110A is distorted significantly by the axially asymmetric in-plane oscillation. A resilient pin 121 is then inserted into the cut 110b, and the oscillator 110A is clamped by first and second washers 122, 123. Subsequently, it is tightened by means of a screw 124 and secured to a base 120A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration actuator using a symmetric elongation vibration mode in a radial direction and a non-axisymmetric in-plane vibration mode, and more particularly to a vibration actuator having an improved rotation stopper for a vibrator. It is.

[0002]

2. Description of the Related Art Conventionally, this type of vibration actuator has
A donut plate-shaped vibration that simultaneously generates a radially symmetric elongation vibration mode extending (expanding and contracting in the radial direction) from the center to the outer peripheral direction and a non-axisymmetric in-plane vibration mode bending non-axisymmetrically in the same plane. The structure using the child is "(R,
1)-((1, 1)) mode improvement of ultrasonic linear motor using piezoelectric ring (Takano, Tomikawa; Proceedings of the 12th Ferroelectric Application Conference, pp. 79-80) "," New Edition Ultrasonic Wave " Motor (Ueba, Tomikawa; Trikeps, P.22-2
3, p. 67-68) "and Japanese Patent Publication No. 6-26994, which are suitable for a thin structure and have characteristics such as high speed and high thrust.

(Structure of vibrator) FIG. 10 is a view showing a conventional example of a vibrator of a vibration actuator using a radially symmetric elongation vibration mode and a non-axially symmetric in-plane vibration mode. The vibrator 10 includes a piezoelectric element 11, an electrode 12, and the like. The piezoelectric element 11 is formed, for example, by forming a piezoelectric material such as PZT into a donut plate shape and polarizing the entire surface in the plate thickness direction. This donut plate shape has a radially symmetric elongation vibration mode (R, 1) and a non-axisymmetric in-plane vibration mode ((1,
It is designed and manufactured so that the resonance frequencies of 1)) become almost equal.

The piezoelectric element 11 has fan-shaped first and second electrodes 12a and 12b formed on the surface thereof [FIG.
0 (A)], and the third electrode 12c is formed on almost the entire back surface [FIG. 10 (B)].

A first AC voltage is applied to the first electrode 12a of the vibrator 10 by a driving voltage generator including an oscillator, a phase shifter, an amplifier and the like. Also, the second electrode 1
2b has an electrical phase (π / π) with the first AC voltage.
A second AC voltage that differs by 2) is applied. The third electrode 12c on the back surface is connected to the GND potential.

The vibrator 10 has a frequency of AC voltage of 2
By approaching the resonance frequency of the two vibration modes,
Resonating in two modes, radially symmetric elongational vibration and non-axisymmetric in-plane vibration occur simultaneously.

The radially symmetric elongation vibration (R, 1) is shown in FIG.
As shown in (C), the vibration is a symmetrical expansion / contraction vibration in the radial direction (radial direction) with node A as a node, and has radial components Ur at points C1 and C2. In addition, non-axisymmetric in-plane vibration ((1,
1)), as shown in FIG. 10 (D), using the points B1 and B2 as nodes, as shown by a broken line, distortion (crushing) in the same plane, , And has a displacement component Uθ in the direction of the arrow at points C1 and C2 on the circumference. And, the vibrator 10 has C1,
An elliptical motion as shown in FIG. 10A is generated as a displacement obtained by combining the two vibrations at the position of the point C2 (the driving force extracting portion).

(Configuration of Vibration Actuator) FIG.
FIG. 9 is a diagram illustrating a configuration of a conventional vibration actuator.
The relative movement member 30 is freely movable in the x direction and is in pressure contact with the sliding member 13 of the vibrator 10 by a guide mechanism and a pressure mechanism (not shown). The mat 19 is a pair of ring-shaped mats formed of an elastic member and provided with a central hole 19a. The base 20 is a base plate provided with a screw hole 20a. The outer diameter of the collar member 36 is smaller than the inner diameter of the central hole 19a, and a flange portion 36a is formed at one end. The height between the flange portion 36 a and the base 20 (= the length of the cylindrical portion of the collar member 36)
It is slightly smaller than the total thickness of 9 and the vibrator 10. Screw 3
Reference numeral 7 denotes a screw for fastening and fixing the collar member 36, the mat 19, and the vibrator 10 together.

In such a configuration, the lower mat 1
9, the vibrator 10 and the upper mat 19 are sequentially placed on the base 2
0, the collar member 36 is inserted into each central hole, the screw 24 is inserted into the collar member 36, and screwed into the screw hole 20a, whereby the flange portion 36a
Thus, the vibrator 10 is connected to the base 20 via the mat 19.
And the flange portion 36a. At this time, the height of the collar member 36 up to the flange portion 36a is
The vibrator 10 is formed to be slightly smaller than the total thickness of the vibrator 10, so that the out-of-plane movement of the vibrator 10 is restricted by the pressing force generated by the elastic deformation of both mats 19. In addition, the movement of the vibrator 10 in the x direction and the y direction is regulated by the collar member 36. Further, the movement of the z-axis rotation is regulated by the frictional force between the mat 19 and the vibrator 10.

(Operation of Vibration Actuator) As described above, the first and second electrodes 12 are driven by the drive voltage generator.
a and 12b are applied with the first and second AC voltages,
Elliptical motion occurs at the position where the sliding member 13 is provided. At this time, since the relative motion member 30 is in pressure contact with the sliding member 13, there is a gap between the sliding surface 13a and the relative motion member 30.
A frictional force is generated in the moving direction of the relative motion member 30, and a linear driving force of the relative motion member 30 can be obtained.

The phase difference between the first and second AC voltages is π / 2
, The straight traveling direction can be reversed. Further, by moving the driving frequency closer to or farther from the resonance frequency of the vibrator, it is possible to increase or decrease the speed of the straight running operation. The speed can be increased or decreased by increasing or decreasing the AC voltage.

[0012]

However, in the conventional device described above, the rotation of the vibrator is prevented by the frictional force between the mat 19 and the vibrator 10, so that the vibrator 10 is However, when a driving force is generated, there is a problem that the vibrator 10 is rotated by the reaction. If the amount of squeezing of the mat 19 is increased in order to solve this problem, the vibration of the vibrator 10 is suppressed, and a disadvantage such as an inability to efficiently obtain a driving force occurs. In the non-axially symmetric in-plane vibration, ideally, the position where the sliding member is attached should vibrate in the x-axis direction. However, since the shape of the piezoelectric element is axially symmetric, the direction is aimed at. In some cases, the direction may deviate from the x direction, and in this case, there is a problem that the vibration actuator cannot sufficiently exhibit the original force.

An object of the present invention is to provide a vibrator with a simple structure, which does not hinder vibration of the vibrator, reliably stops the rotation of the vibrator and supports the vibrator, so that the vibration direction of the non-axisymmetric in-plane vibration can be adjusted as intended. And to provide an efficient vibration actuator.

[0014]

The present invention solves the above-mentioned problems by the following means. In addition, in order to make it easy to understand, description is given with reference numerals corresponding to the embodiment of the present invention, but the present invention is not limited to this. That is, the invention of claim 1 provides a vibrator (11) that simultaneously generates a radially symmetric elongation vibration mode that expands and contracts in a radial direction and a non-axisymmetric in-plane vibration mode that bends non-axisymmetrically in the same plane.
0A to 110D, 210A to 210D, 310A to 31
0C), the vibrator is an annular thin plate, and a part of the rotation stopper (110
b to 110e, 210a to 210e, 310a, 310
b, 317) and a positioning part (121, 126a, 227) that engages with the rotation stopper.

According to a second aspect of the present invention, in the vibration actuator according to the first aspect, the rotation stoppers (110b to 110b) are connected to each other.
110e, 210a to 210e, 310a, 310b,
317) is a vibration actuator, which is provided so as not to hinder or promote vibration in the non-axisymmetric in-plane vibration mode.

[0016] The invention of claim 3 is claim 1 or claim 2.
3. The vibration actuator according to claim 2, wherein the rotation stoppers (110b to 110e, 310a, 310b, 317)
Is a vibration actuator provided so as to change the relative rigidity between a portion where the distortion of the vibrator due to the non-axisymmetric in-plane vibration mode is large and a portion where the distortion is small.

According to a fourth aspect of the present invention, there is provided the first to third aspects.
In the vibration actuator according to any one of the above, the rotation stoppers (110b, 110c, 110e,
310a, 310b) are in a vibration plane of the vibrator, are orthogonal to a line connecting two nodes of the non-axisymmetric in-plane vibration, and are on a line passing through a center of a substantially circular ring of the vibrator. A vibration actuator having a shape in which a part of a vibrator is removed.

According to a fifth aspect of the present invention, in the vibration actuator according to the fourth aspect, the rotation stopper (110b,
Reference numeral 110c) denotes a vibration actuator, which is a notch provided in an inner peripheral portion of the vibrator.

The invention according to claim 6 is the invention according to claims 1 to 3.
In the vibration actuator according to any one of the above, the rotation stopper (317) is in a vibration plane of the vibrator, is on a line connecting two nodes of the non-axisymmetric in-plane vibration, and A vibration actuator characterized by adding a member having high rigidity to a vibrator.

[0020] The invention of claim 7 is the invention of claim 1 or claim 2.
In the vibration actuator according to the above, the vibrator,
An electrode (212a, 212b, 212c), wherein the detents (210a, 210b, 210e) are on or near two nodes of the non-axisymmetric in-plane vibration mode, and have an area of the electrode A vibration actuator characterized by being provided so as to be able to be widely taken.

According to an eighth aspect of the present invention, in the vibration actuator according to the seventh aspect, the rotation stopper (210a,
210b, 210e) are vibration actuators characterized by being through holes or substantially conical depressions provided on the two nodes.

According to a ninth aspect of the present invention, there are provided the first to eighth aspects.
In the vibration actuator according to any one of the above, the positioning portion (121, 126a, 227)
A vibration actuator having elasticity that does not hinder in-plane vibration of the vibrator.

A tenth aspect of the present invention is the vibration actuator according to the ninth aspect, wherein the positioning portion is a pin (121).

According to an eleventh aspect of the present invention, in the vibration actuator according to any one of the first to tenth aspects, the positioning portion supplies a driving power to the vibrator (210C). Is a vibration actuator.

[0025]

Embodiments of the present invention will be described below in more detail with reference to the drawings. (First Embodiment) FIG. 1 is a view for explaining a first embodiment of a vibration actuator according to the present invention. FIG. 1 (a)
Shows an assembled state, and (b) is an exploded view of a main part. Note that the same reference numerals are given to the portions that perform the same functions as those of the above-described conventional example, and the overlapping description will be appropriately omitted. In the first embodiment, an embodiment will be described in which the shape of the hole at the center of the vibrator is irregular in order to stop the vibrator from rotating.

The vibrator 110A is a vibrator that generates a radially symmetric elongation vibration mode and a non-axially symmetric in-plane vibration mode, and includes a piezoelectric element 111 and first and second electrodes 112a and 112a.
12b, a sliding member 113 and the like. Piezoelectric element 1
Reference numeral 11 denotes an electromechanical transducer such as a piezoelectric ceramic. The boundary between the first and second electrodes 112a and 112b is
It is arranged along a line connecting two nodes of the non-axisymmetric in-plane vibration mode. The central hole 110a of the vibrator 110A is
A part thereof has two notches 110b. The notch 110b has the first and second electrodes 112a and 112b.
And is on a straight line in the vibration plane.

The first washer 122 includes a vibrator 110A.
And a member that determines the position of the vibrator in the out-of-plane direction and does not hinder in-plane vibration of the vibrator 110A. The material is small felt, urethane, etc. The first washer 122 has a hole 122a including a notch 122b, similarly to the vibrator 110A.

The base 120A is a base for fixing the vibrator 110A, and has two pins 121 at positions corresponding to the notches 110b of the vibrator 110A.
21 has a screw hole 120a.

The pin 121 is a pin that fits into the notch 110b of the vibrator 110A to position the vibrator 110A in the plane (x-axis direction, y-axis direction, and z-axis rotation). It has elasticity so as not to hinder the in-plane vibration.

The second washer 123 includes a vibrator 110A.
And the screw 124, and is a member that determines the position of the vibrator 110A in the out-of-plane direction, similarly to the first washer 122. In order not to hinder the in-plane vibration of the vibrator 110A,
Resin containing PTFE with low friction or felt, urethane or the like with low shear deformation resistance is used as the material. The second washer 123 has a hole 123a at the center for passing the screw 124.

The screw 124 connects the second washer 123, the vibrator 110A, and the first washer 122 to the base 120A.
It is a screw to tighten together.

The notch 110b of the vibrator 110A is orthogonal to the boundary between the first and second electrodes 112a and 112b (the line connecting the two nodes of the non-axisymmetric in-plane vibration mode), and is located within the vibration plane. It is on a straight line. The position on this straight line is
Vibrator 110A with non-axisymmetric in-plane vibration mode of 10A
Is a portion having a large amount of distortion (hereinafter, a large distortion portion). By providing the notch 110b here,
Non-axially symmetric in-plane vibration in the X direction of A is more likely to occur.

(Modification of First Embodiment) FIG.
It is a figure showing a modification of a method of attaching vibrator 110A of an embodiment to a base. The base 120B is a base for fixing the vibrator 110A. The base 120B includes two pins 121 at positions corresponding to the notches 110b of the vibrator 110A.
Is attached.

The spacer 125 includes the pin 121 and the vibrator 1.
The spacer is used to increase the arm length of the pin 121 by using the spacer to increase the arm length of the pin 121.
The required elasticity is ensured.

FIG. 3 is a sectional view of the vibration actuator taken along a plane connecting the center lines of the two pins 121 (AA in FIG. 2).
FIG. The vibrator 110A and the pin 121 are bonded with an elastic adhesive such as an epoxy adhesive on the inner surface of the notch 110b so as not to hinder the vibration.

FIG. 4 is a view illustrating four modified examples of the vibrator of the first embodiment. The vibrator 110 shown in FIG.
A is the form described above. The vibrator 110B shown in FIG. 4B has a key groove 110c, and the position is provided at a position corresponding to the large distortion portion. Therefore, the rigidity of the large distortion part of the vibrator 110B is relatively lower than that of the other parts. The vibrator 110C shown in FIG.
A part of the center hole has a D-cut shape 110d. The position of the D-cut shape 110d is at a position rotated by 90 degrees from the large distortion portion, and this position has a relatively increased rigidity compared with the other portions, that is, the large distortion portion. From the opposite viewpoint, the rigidity of the large strain portion is relatively reduced. The vibrator 110D shown in FIG. 4D has an oval shape in the center hole. The position of the semicircular portion 110e of this shape is provided at a position corresponding to the large distortion portion. Therefore, the rigidity of the large distortion portion of the vibrator 110D is relatively lower than that of the other portions.

FIG. 5 shows the vibrator 110 shown in FIG.
It is a figure showing one embodiment of a method of fixing B to base 120c. The base 120c includes a mounting block 126 having elasticity. Mounting block 126
Is a convex shape 126a corresponding to the hole shape of the vibrator 110B.
The vibrator 110B has the convex shape 126a
Is fitted in the hole of the vibrator, and the second washer 12
3, is fixed to the base 120c by the screw 124.

The vibrator 110 shown in FIGS. 4C and 4D
C and 110D are also fixed by the same method as the vibrator 110B.

As described above, according to the first embodiment, the shape of the hole at the center of the vibrator is made irregular so that the vibrator has a shape for stopping rotation. Since the shape and arrangement are relatively reduced, the direction of non-axisymmetric in-plane vibration can be generated in a desired direction. Further, the positioning is performed without hindering the necessary vibration of the vibrator and the rotation of the vibrator is reliably prevented, so that the driving performance can be improved. Further, since the positioning accuracy with respect to the relative motion member is also improved, the driving performance of the entire vibration actuator can be improved.

(Second Embodiment) FIG. 6 is a diagram for explaining a second embodiment. FIG. 6A is a view showing the vibrator 210A taken out, FIG. 6B is a view showing an assembled state, and FIG. 6C is a sectional view taken along the line CC in FIG. 6B. FIG. In the second embodiment, an embodiment will be described in which the rotation stopper of the vibrator is provided at a node of non-axisymmetric in-plane vibration of the vibrator.

FIG. 7 is a view for explaining the vibrator 210A. FIG. 7A shows the first and second electrodes 212a and 212a.
FIG. 7B shows a surface on the side b, and FIG. 7B shows a cross section BB. The vibrator 210A is a node of non-axisymmetric in-plane vibration of the vibrator 210A, and includes first and second electrodes 212a and 212a.
At a point on the boundary of b, a conical hollow 210a is
Are provided.

Returning to FIG. 6, the base 220 includes a vibrator table 226 and a vibrator holder 227. Transducer holder 2
27 is a holding part 2 having elasticity and acting as a leaf spring.
27a and 227b. Pressing parts 227c, 227
d represents two recesses 210a of the vibrator 210A, respectively.
, And the projections 227c and 227d have conical tips.

The vibrator 210A is shown in FIGS.
As shown in (c), the projections 227c and 227d engage with the depressions 210a and 210b in a state where the projections 227c and 227d are pressed against the oscillator base 226 with a predetermined amount of force by the elasticity of the oscillator holder 227, and the position is determined.

At the node of the non-axially symmetric in-plane vibration of the vibrator 210A, only the vibration in the y-direction due to the radially symmetric elongation vibration occurs, and if the vibrator 210A is stopped and fixed at this position, the positioning of the pins and the like is performed. The amount of elastic deformation required for the portion is also minimized, and the adverse effect of suppressing vibration of the vibrator 210A is also minimized.

On the boundary between the first and second electrodes 212a and 212b, there is a portion where no electrode exists (hereinafter, a non-electrode portion) in order to maintain insulation between the two electrodes. The width of the non-electrode portion needs to have a predetermined width in order to absorb manufacturing variations and the like. However, since the non-electrode portion has no electrode, it does not contribute to driving of the vibrator. On the other hand, portions such as holes required for stopping and fixing the vibrator do not have electrodes, and do not contribute to driving of the vibrator. These portions that do not contribute to the driving of the vibrator need to be reduced as much as possible for the purpose of the vibration actuator to generate the driving force, and it is necessary to increase the area of the electrode instead. Recess 21 of vibrator 210A of second embodiment
0a, 210b are the first and second electrodes 212a, 212
Since they are provided on the boundary line b (non-electrode portion), the area of the electrodes can be made larger than in the case where they are arranged at separate positions.

(Modification of Second Embodiment) FIG.
It is the figure which illustrated three deformation forms of the vibrator of an embodiment. In the vibrator 210B shown in FIG. 8A, a rectangular through hole 210b is provided at a node of non-axisymmetric in-plane vibration of the vibrator 210B.
This is a form in which a rotation stopper is provided. The short side of the rectangle of the through hole 210b is set in the y direction, and the plate material having a rectangular cross section inserted therein is arranged so as to be easily elastically deformed in the y direction. The node corresponds to the case where only the vibration in the y direction due to the radially symmetric elongation vibration is generated, and the vibration of the vibrator 210B is not hindered by the elastic deformation of the plate material. Also, a through hole 2 is formed on the non-electrode portion.
Since 10b is provided, the electrode area can be maximized. The positioning in the out-of-plane direction is performed in the same manner as the method described in the first embodiment.

The vibrator 210C shown in FIG. 8 (b) is a node of the non-axially symmetric in-plane vibration of the vibrator 210C, and has a through hole 210c at a point on the first electrode 210a.
The other node of the non-axially symmetric in-plane vibration at 0C,
In this embodiment, a through hole 210d is provided at a point on the electrode 210b. Positioning members having conductivity and elasticity are inserted into the through holes 210c and 210d, soldered to the respective electrodes, and are simultaneously fixed and electrically connected. Here, as a material of the pin, for example, a tin-plated copper wire is suitable when positioning rigidity is relatively unnecessary, and a nickel-plated stainless steel pin is suitable when rigidity is required. The positioning in the out-of-plane direction is performed in the same manner as the method described in the first embodiment.

The vibrator 210D shown in FIG. 8C is a node of non-axially symmetric in-plane vibration of the vibrator 210D, and has a conical recess 21 at a point on the third electrode 210c (GND side).
0e is provided at two places, and the vibrator 21 shown earlier is provided.
A rotation stop portion (dent) of 0A is provided on the back surface. The vibrator 210D is fixed in the same manner as the vibrator 210A, and the effect is the same as that of the vibrator 210A.

As described above, in the second embodiment, the non-axially symmetric in-plane vibration node is provided with the rotation stop portion of the vibrator, so that the non-axially symmetric in-plane vibration of the vibrator is not affected at all. ,
Fixing itself is also easy. Further, since the maximum area of the electrode can be ensured, it is possible to provide an efficient vibration actuator without hindering the vibration of the vibrator.

(Third Embodiment) FIG. 9 is a view for explaining a third embodiment. In the third embodiment, a form in which a rotation stopping portion of the vibrator is provided on the outer periphery of the vibrator will be described. The vibrator 310A shown in FIG. 9A has a form in which two notches 310a are provided symmetrically on the outer periphery of the large distortion portion of the vibrator 310A. By fitting elastic positioning portions such as pins to these two places, the vibrator 310A is stopped and fixed. Due to the notch 310a, the rigidity of the large distortion portion is relatively reduced, and the vibration of the vibrator 310A is more likely to occur.

In the vibrator 310B shown in FIG. 9B, one notch 310a is formed at the outer periphery of the large distortion portion of the vibrator 310B.
It is a form provided in a place. An elastic positioning portion such as a pin is fitted into the notch 310b, and the vibrator 310B is stopped and fixed together with a shaft fitted into the central hole 310c. Due to the notch 310b, the rigidity of the large distortion portion is relatively reduced, and the vibration of the vibrator 310B is more likely to occur.

The vibrator 310C shown in FIG. 9C is a fixing member 3 having sufficient rigidity at a position symmetrical with the sliding portion 313.
17 is provided. The vibrator 310C is fixed using a positioning portion having a shape that engages with the fixing member 317. Since the fixing member 317 is integrally attached, the rigidity of this portion is relatively improved. In other words, the rigidity of the large distortion portion relatively decreases, and the vibration of the vibrator 310C is more likely to occur.

As described above, according to the third embodiment, the shape of the rotation stopping portion is such that the rigidity of the large distortion portion of the vibrator is relatively reduced, so that the vibration of the vibrator is not hindered. Non-axially symmetrical in-plane vibration in the X direction of the child is easily generated, and an efficient vibration actuator can be provided.

(Modifications) Various modifications and changes are possible without being limited to the above-described embodiments, and these are also within the equivalent scope of the present invention.

(1) In each embodiment, an example is shown in which the relative motion member is brought into pressure contact with the vibrator. However, the present invention is not limited to this.
The vibrator may be brought into pressure contact with the relative motion member.

(2) In each embodiment, the vibrator is 1
Although an example using two piezoelectric elements has been shown, the invention is not limited to this.
For example, a vibrator in which a plurality of piezoelectric elements are stacked, or a vibrator in which members other than the piezoelectric elements are stacked may be used.

(3) In each of the embodiments, an example in which the vibrator uses a piezoelectric element such as a piezoelectric ceramic has been described.
However, the invention is not limited thereto, and for example, an electrostrictive element or a magnetostrictive element may be used.

[0058]

As described above in detail, according to the present invention, the vibration actuator can suppress the disturbance of the vibration of the vibrator to a low level, securely stop and fix the vibrator, and perform stable driving. it can. In addition, the anti-rotation part provided on the vibrator is configured so that the vibration direction of the non-axisymmetric in-plane vibration is positively generated in the target direction, so that the vibration direction of the non-axisymmetric in-plane vibration is stable and accurate. The vibration of the vibrator can be converted into the driving force without waste, and the driving efficiency of the vibration actuator is improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a modified example of a method of attaching the vibrator 110A of the first embodiment to a base.

FIG. 3 is an AA cross section of FIG. 2;

FIG. 4 is a view illustrating four modified examples of the vibrator of the first embodiment.

FIG. 5 is a view showing one embodiment of a method of fixing a vibrator 110B to a base 120c.

FIG. 6 is a diagram illustrating a second embodiment.

FIG. 7 is a diagram illustrating a vibrator 210A.

FIG. 8 is a view illustrating three modified examples of the vibrator of the second embodiment.

FIG. 9 is a diagram illustrating a third embodiment.

FIG. 10 is a diagram illustrating a vibrator of a conventional vibration actuator.

FIG. 11 is a diagram illustrating a configuration of a conventional vibration actuator.

[Explanation of symbols]

10, 110A to 110D, 210A to 210D, 31
0A to 310C Vibrator 12a, 112a, 212a First electrode 12b, 112b, 212b Second electrode 12c, 212c Third electrode 13, 113, 213, 313 Sliding material 110b, 310a, 310b Notch 210a, 210e Recesses 210b, 210c, 210d Through-hole 317 Fixing member

Continuing from the front page (72) Inventor Tsunemi Gonda 3-2-3 Marunouchi, Chiyoda-ku, Tokyo Nikon Corporation (72) Inventor Tomoaki Suzuki 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Nikon Corporation F term (reference) 5H680 AA06 AA08 BB13 BB15 CC02 DD01 DD15 DD23 DD30 DD53 DD55 DD57 DD73 DD83 DD85 DD92 EE10 FF03 FF04 FF05 FF08 FF16 FF21 FF23 FF25 FF33 GG11 GG18 GG19 GG20

Claims (11)

[Claims] 1. A vibration actuator using a vibrator that simultaneously generates a radially symmetric elongation vibration mode that expands and contracts in a radial direction and a non-axisymmetric in-plane vibration mode that bends non-axisymmetrically in the same plane, The vibrator is an annular thin plate, partially having a rotation stop portion, and provided with a positioning portion that engages with the rotation stop portion. 2. The vibration actuator according to claim 1, wherein the rotation stopping portion is provided so as not to hinder or promote vibration in the non-axially symmetric in-plane vibration mode. Actuator. 3. The vibration actuator according to claim 1, wherein the rotation stopper has a relative position between a portion having a large distortion and a portion having a small distortion of the vibrator due to the non-axisymmetric in-plane vibration mode. A vibration actuator characterized by being provided so as to change rigidity. 4. One of claims 1 to 3
In the vibration actuator described in the paragraph, the rotation stopper is in a vibration plane of the vibrator, is orthogonal to a line connecting two nodes of the non-axisymmetric in-plane vibration, and is substantially a ring of the vibrator. A vibrating actuator which is on a line passing through the center and has a shape in which a part of the vibrator is removed. 5. The vibration actuator according to claim 4, wherein the rotation stopping portion is a notch provided on an inner peripheral portion of the vibrator. 6. Any one of claims 1 to 3
In the vibration actuator according to the paragraph, the rotation stopper is in a vibration plane of the vibrator, is on a line connecting two nodes of the non-axisymmetric in-plane vibration, and provides the vibrator with a highly rigid member. A vibration actuator characterized by being formed by adding. 7. The vibration actuator according to claim 1, wherein the vibrator has an electrode, and the rotation stopper is on or at two nodes of the non-axisymmetric in-plane vibration mode. , And provided so as to increase the area of the electrode. 8. The vibration actuator according to claim 7, wherein the rotation stopper is a through-hole or a substantially conical recess provided on the two nodes. 9. Any one of claims 1 to 8
The vibration actuator according to any one of the preceding claims, wherein the positioning portion has an elasticity that does not hinder in-plane vibration of the vibrator. 10. The vibration actuator according to claim 9, wherein the positioning portion is a pin. 11. The vibration actuator according to claim 1, wherein the positioning unit supplies a driving power to the vibrator.