JP2012130231A - Vibration wave driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that the output of a whole device is reduced due to frictional force of the contact surface of a vibrator, about which driving force does not contribute to the moving direction of a mobile body, becoming a load.SOLUTION: A vibration wave driving device includes a vibrator including an electro-mechanical energy conversion element, and a supporting part for supporting the vibrator, and excites the vibrator to vibrate and moves a mobile body contacting with the vibrator by frictional force. The vibration wave driving device includes a movement mechanism for enabling the vibrator to move in a second direction crossing a first direction the vibrator drives within a plane parallel to a plane where the vibrator and the mobile body contact with each other, and a control unit for performing change operation changing a contact position between the vibrator and the mobile body.

Description

  The present invention relates to a configuration of a vibration type drive mechanism that generates vibration waves in a plurality of ultrasonic vibrators and relatively moves a moving body that contacts the ultrasonic vibrators or vibrator groups by a frictional force.

  Conventionally, proposals have been made to generate a driving force by a piezoelectric vibrator or the like to drive a moving body in frictional contact. An application example of an actuator using a plurality of linear motion (also referred to as linear) piezoelectric vibrators has also been proposed.

  Patent Document 1 discloses an apparatus configuration as an application example of an actuator using a conventional linear motion type piezoelectric vibrator as shown in FIGS. 13 and 14.

FIG. 13 is a perspective view of a camera as an imaging apparatus.
Three vibrators (211, 212, 213 (the top view of each vibrator is shown in FIG. 14)) for driving the image sensor 203 are arranged, and the back side of the moving body 204 to which the image sensor 203 is attached is respectively Each point is received by three contact portions. Further, the ultrasonic transducers 211 to 213 and the movable body 4 are pressed by using a magnetic force such as a magnet (not shown). Reference numeral 201 denotes an image sensor body, and 202 denotes a lens barrel portion that supports a lens and the like.
Reference numerals 263P, 263y, and 263R denote angular acceleration sensors that detect the rotational movement of the imaging apparatus.

  The angular acceleration sensor detects a change in posture of the image pickup apparatus due to camera shake, etc., and generates a driving force for the vibrator so that the signal of the image sensor 203 is not affected by the camera shake, so that the image sensor is moved with respect to the optical axis. Moved to a vertical surface.

FIG. 14 is a top view showing the arrangement of the transducers and position detection sensors and the direction of the driving force in the imaging apparatus of FIG. 13 when driving the moving body 204 in the Y direction.
The position detection sensors 222 to 224 obtain position information by reading scales attached to opposite positions, and obtain the moving direction of the moving body 204 by calculating each position information.

In FIG. 14, when the force generated by the vibrator 211 when driving the moving body 204 in the Y direction is f1, the force generated by the vibrator 212 is f2, and the force generated by the vibrator 213 is f3, f1 = 0. A force of × F f2 = F f3 = F is applied.
That is, when driving the moving body 204 in the Y direction, the vibrators 212 and 213 have a driving force component in the moving direction, but the vibrator 211 does not have a driving force component in the moving direction, that is, the Y direction. Therefore, when the moving body 204 is driven in the Y direction, the driving force of the vibrator 211 becomes zero (does not contribute as driving force). Here, the vibrator 211 and the moving body 204 are in contact with each other, and a frictional force acts on the contact portion. Therefore, when the vibrator 211 does not vibrate, there is a problem that the frictional force at the contact portion between the vibrator 211 and the moving body 2004 becomes a load as it is and becomes a resistance component that inhibits the driving force.

  In the above example, the body is moved by using a plurality of vibrators. However, even if there is only one vibrator, a force in a direction different from the moving direction is applied to the vibrator or moving body from the outside. In some cases, similar problems can occur.

  In order to reduce the frictional load, a driving means that reduces the frictional force between the vibrator and the moving body by causing the vibrator 211 to generate a vibration but not to generate a vibration is conceivable.

JP 2009-031353 A

  A conventional driving device using a plurality of vibrators transmits a driving force to a moving body via a frictional force by applying a driving force in a direction in which the moving body is moved by combining forces of a plurality of vibrators. However, there is a problem that the frictional force on the contact surface of the vibrator, to which the driving force does not contribute to the moving direction of the moving body, becomes a load and the output of the entire apparatus is reduced.

  Further, there is a problem that even if there is only one vibrator, a similar problem may occur when a force in a direction different from the moving direction is applied to the vibrator or the moving body from the outside.

The present invention has been completed as a result of intensive studies by the present inventors in order to solve the above-mentioned problems, and the gist of the present invention is a vibrator having an electro-mechanical energy conversion element,
A vibration wave driving device that includes a support portion that supports the vibrator, excites vibration to the vibrator, and moves a moving body that contacts the vibrator by a frictional force. A moving mechanism that allows the vibrator to move in a second direction that intersects with a first direction that the vibrator drives within a plane that is parallel to a surface that contacts the moving body; and the vibration And a control unit that performs a changing operation for changing a contact position between the child and the moving body.

  The present invention further includes a vibrator having an electro-mechanical energy conversion element and a support portion that supports the vibrator, wherein the vibrator is excited by vibration and is brought into contact with the vibrator by a frictional force. A driving method of a vibration wave driving apparatus for moving a moving body, wherein the driving method is in a plane parallel to a surface where the vibrator and the moving body are in contact with each other, and intersects a first direction in which the vibrator is driven. A moving mechanism that allows the vibrator to move in a second direction; and a control unit that performs a changing operation to change a contact position between the vibrator and the moving body. A first step of performing a first driving operation for generating a driving force in a direction; a second step of generating a vibration in a direction perpendicular to the plane and changing a position between the vibrator and the moving body; And a second process step for performing a driving operation.

  By adopting the configuration of the present invention, the above-described problems can be solved, and the load due to the frictional force of the contact surface of the vibrator that does not contribute the driving force to the moving direction of the moving body can be reduced by the moving mechanism. Further, even when the sliding surface of the moving body slips and deviates from the moving range of the moving mechanism, it can be recovered by changing the contact position between the vibrator and the moving body.

  And it becomes possible to move the moving body with a higher stroke by increasing the displacement amount of the vibrator.

The figure for demonstrating the 1st Embodiment of this invention The figure for demonstrating the drive principle of the vibrator | oscillator of this invention The figure which shows the electrode pattern of the piezoelectric element part of the vibrator | oscillator of this invention The figure which shows the relationship between the voltage input into the piezoelectric element of this invention, and the mode which generate | occur | produces The figure explaining operation | movement of the moving mechanism of this invention The figure explaining the structure which provided the moving mechanism in the vibration type drive mechanism The figure which shows operation | movement of the moving mechanism of this invention The figure which shows the operation | movement principle of 2nd Example. The figure which shows the operation | movement principle of the one part vibrator | oscillator part of 2nd Example. The figure which shows the operation | movement algorithm of 2nd Example. The figure which shows the structure of the vibration type drive mechanism of 3rd Example. The figure which shows operation | movement of the vibration type drive mechanism of 3rd Example. The figure which shows the structure of the conventional multi-degree-of-freedom drive device The figure which shows the structure of the drive part of the conventional multi-degree-of-freedom drive device.

Embodiments of the present invention will be described below.
The present invention includes a vibrator having an electro-mechanical energy conversion element. By applying an alternating signal to the electro-mechanical energy conversion element, the vibrator is excited by a frictional force. The present invention relates to a vibration wave driving device that moves a moving body that comes into contact therewith.

  In the present invention, the “surface where the vibrator and the moving body come into contact” means a virtual plane including a plurality of contact points where the vibrator and the vibrator come into contact. The “plane parallel to the surface where the vibrator and the moving body contact” means a virtual plane parallel to the above-described virtual “surface where the vibrator and the moving body contact”. Exists. These planes are planes that are defined to clearly grasp the first direction and the second direction, which are directions for defining the moving direction of the moving mechanism of the present invention. In the present invention, the first direction is a direction in which the vibrator moves the moving body, and is also referred to as a driving direction. Further, the second direction of the present invention is a direction that can be moved by the moving mechanism of the present invention, and is also referred to as a “drilling direction”. And when a force acts in the direction which crosses the original moving direction of a moving body, the direction which moves (dodges) without resisting the said force is meant. The moving mechanism of the present invention is characterized in that it can move in the second direction defined by the above configuration, and is also referred to as a “drum mechanism”.

  In the present invention, the vibrator can be selectively moved in the second direction (not substantially moved in the first direction) by providing a guide member that can move only in the second direction. realizable. Further, it can be realized by supporting the vibrator with an elastic member (typically, a spring member) as a support portion, and making the elastic member easy to be displaced only in a specific direction.

  As a specific form of the present invention, rigidity is high in the direction in which the force of the vibrator is generated between the support portion supporting the vibrator and the vibrator, and is different from the direction in which the force of the vibrator is generated. A configuration in which a spring mechanism with low rigidity is provided in the direction is mentioned. With this configuration, the vibrator is supported with high rigidity in the first direction, and the driving force can be efficiently transmitted to the moving body. When a force acts in the second direction, the spring mechanism is deformed to move (dodge) the moving body without generating a large force between the vibrator and the frictional contact portion of the moving body. Can do. In this case, the direction in which the force of the vibrator is generated between the support portion that supports the vibrator and the vibrator is the first direction (the direction in which the moving body moves), and the direction in which the force of the vibrator is generated. Is a second direction (a direction intersecting the direction in which the moving body moves). Hereinafter, the mechanism portion provided with the spring portion is also referred to as a dowel spring mechanism.

  In the present invention, in the dovetail spring mechanism, the friction contact portion between the vibrator and the moving body slips due to long-time driving or the like, and the reference position of the moving body and the movable range of the spring mechanism at the contact position between the vibrator and the moving body. Even when the center is shifted, the reference position can be recovered. Here, in the present invention, the reference position means a reference position for driving the moving body, and is typically the center position of the moving range of the moving body. Can be determined.

  In the present invention, the recovery of the contact position between the vibrator and the moving body is performed by a control unit that performs a changing operation for changing the contact position between the vibrator and the moving body. Specifically, in order to reduce the frictional force between the vibrator and the moving body, the vibrator can be vibrated in a direction perpendicular to a plane parallel to the surface where the vibrator and the moving body are in contact.

  For example, when the center position of the moving range, which is the reference position of the moving body, deviates from the center of the movable range of the spring, a force is exerted on the spring mechanism to return to the neutral position of the spring. At this time, vibration is generated by the restoring force of the spring mechanism by causing each vibrator to vibrate in a direction (normal direction) perpendicular to the plane parallel to the plane where the vibrator and the moving body contact. Misalignment between the child and the moving body can be recovered.

  In the present invention, the step of performing a driving operation (first driving operation) for generating a driving force in the moving direction (first direction) of the moving body is the first step. Then, when the reference position of the moving body and the center of the movable range of the spring mechanism have shifted, vibration is generated in a direction perpendicular to a plane parallel to the surface where the vibrator and the moving body contact, A step of performing an operation (second driving operation) for changing a position between the vibrator and the moving body is a second step.

  Then, by repeating the first step and the second step, the moving body can be efficiently moved with a high stroke. Specifically, when it is necessary to drive at a high stroke in a range larger than the movable range of the spring mechanism, the operation of moving the moving body in the driving direction (first step) and the vibrator and the moving body are in contact with each other. The operation (second process step) of generating vibration in a direction perpendicular to the plane parallel to the surface to be performed is repeated. By controlling the dowel spring mechanism in this way, high stroke driving is possible.

  Further, after the step of moving the moving body to the reference position (third step), the spring mechanism is moved to the neutral position by performing the operation (fourth step) of vibrating the vibrator in the same manner as the second step. Can be returned. Further, after the third step, a step (fifth step) of reciprocating the vibrator along the moving direction of the moving body (reciprocating operation within a minute range) may be provided.

  In the present invention, the state in which the “second direction intersecting the first direction” exists includes a component in a direction different from the moving direction that is the first direction (different from the first direction). This means a state in which a force moving in the direction is generated. In the case where “a component in a direction different from the moving direction that is the first direction exists”, a force is applied to the vibrator or moving body from the outside in a direction different from the first direction (by vibration, contact, or the like). One example is working. Further, in the case of a vibration wave driving device including a plurality of vibrators, when the driving directions of the vibrators are different, “there is a component in a direction different from the moving direction that is the first direction”. Become.

  As described above, a state in which a force moving in a direction different from the moving direction is acting causes output loss as described above. The angle at which the first direction and the second direction intersect typically has the highest possibility of causing an output loss when it is 90 °, but if there is even a slight intersection, the output according to the intersection angle Loss can occur.

  The vibrator according to the present invention includes a diaphragm (also referred to as a vibrating body) and an electromechanical energy conversion element (typically a piezoelectric element such as PZT), and applies a predetermined electric field to the electromechanical energy conversion element. By doing so, a desired vibration can be excited.

  In the present invention, the direct acting vibration wave driving device means a vibration wave driving device that can be driven linearly, and is also called a linear vibration wave driving device. A single unit is configured to move a moving body (also called a driven body) linearly, but by combining a plurality of direct-acting vibration wave driving devices and combining driving forces in different directions, the moving body Can be moved in a desired direction.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these descriptions. In addition, all the “directions” in the embodiments mean directions in “a plane parallel to the surface where the vibrator and the moving body contact”.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIGS. 1A to 1C are configuration diagrams of a vibration wave driving apparatus including a plurality of vibrators according to the present invention. FIG. 1A is a plan view seen from the vibrator side, FIG. 1B is a plan view seen from the moving body side, and FIG. 1C is a side view of the vibration wave drive apparatus.

  As shown in FIG. 1 (a), 11 (a) to 11 (d) are vibrators composed of a plurality of vibrators, and the driving force generated by each vibrator adjacent in the plane on which the vibrators are arranged. Four vibrators are arranged so that the angle formed with the direction (the direction in which the moving body is moved) is 90 °.

  Reference numerals 13 (a) to (c) denote position detection sensors such as encoders, and the scale unit 14 (a) to (c) can detect the arrow direction at a position facing the sensor on the moving body side in FIG. Is arranged.

  The amount of movement of the moving body is detected from the above three position detection sensor signals, and taken as control information into a microcomputer (not shown) or the like, and drive control is performed.

  The moving body in FIG. 1 (b) is in contact with the plurality of vibrators 11 (a) to 11 (d) and moved in the direction in which the driving forces of the four vibrators are combined, and the operation direction is from XY and the center of the base plate. The structure which can move to rotation direction (theta) is taken.

  In addition, friction parts 15 (a) to 15 (d) having high wear resistance are provided at portions of the moving body 4 facing the vibrators 11 (a) to 11 (d). In the present embodiment, the friction members 15 (a) to 15 (d) are attached, but the entire moving body can be made to be a part with high wear resistance.

  In FIG. 1C, 9 is a support portion that supports the vibrators 11 (a) to (d), and 12 is a ball disposed between the moving body 4 and the support portion 9. The ball 12 is housed in a plurality of holes arranged in the support portion 9, and the ball 4 rotates with the movement of the movable body 4, so that the movable body 4 is freely driven in a plane and the support portion 9 is always supported at a constant height. The vibrators 11 (a) to 11 (d) are connected to the support portion 9 via an elastic member described later.

FIG. 2 is a diagram showing a driving principle of a vibrator used in the vibration type driving mechanism of FIG. 1, and two bending vibrations excited by applying an alternating signal to a piezoelectric element which is an electro-mechanical energy conversion element. Represents the mode. The vibration mode in FIG. 2A represents one bending vibration mode (referred to as A mode) of the two bending vibration modes. This A mode is a secondary bending motion in the long side direction (arrow X direction) of the rectangular vibrator 106, and is a bending mode having three nodes parallel to the short side direction (arrow Y direction). is there.
Here, the protrusion 108 is disposed in the vicinity of a position that becomes a node by the vibration of the A mode, and reciprocates in the direction of the arrow X by the vibration of the A mode.

  The vibration mode shown in FIG. 2B represents the other bending vibration mode (referred to as B mode) of the two bending vibration modes. This B mode is a primary bending vibration in the short-side direction (arrow Y direction) of the rectangular vibrator 106, and is a mode having two nodes parallel to the long-side direction (arrow X direction).

Here, the nodes in the A mode and the nodes in the B mode are substantially orthogonal in the XY plane.
Further, the protrusion 108 is disposed in the vicinity of a position that becomes antinode by B-mode vibration, and reciprocates in the arrow Z direction by B-mode vibration.

By generating the above-described vibrations of the A mode and the B mode with a predetermined phase difference, an elliptical motion can be generated at the tip of the protrusion 108.
FIG. 3 shows an electrode pattern of the piezoelectric element portion of the vibrator used in this embodiment. Reference numeral 20 denotes a piezoelectric element, and a rectangular portion is divided into two and V1 and V2 are applied.
FIG. 4 shows the relationship between the voltage input to the piezoelectric element of FIG. 3 and the generated mode. As can be seen from FIG. 4, the B mode of FIG. 2 is vibrated when the phase difference between Va and Vb is 0 °, and the A mode is vibrated when the phase difference is 180 °. When the phase difference is between them, the modes are combined to generate a driving force.

  FIG. 5 shows that the vibrator provided in FIG. 1A has a large spring rigidity in the direction in which the force of the vibrator is generated (first direction) and is orthogonal to the direction in which the force of the vibrator is generated ( (Second direction) is a diagram for explaining the operation of a spring mechanism (a dovetail spring mechanism) that is supported in a state in which the spring rigidity is low.

  Reference numeral 17 denotes an attachment portion for attaching the vibrator 11 ′ to the support portion 9. Reference numeral 18 denotes a spring portion having different rigidity in a direction orthogonal to the direction in which the force of the vibrator is generated. Reference numeral 15 ′ denotes a friction member attached to the moving body and moves integrally with the moving body. In FIG. 5, the friction material portion 15 ′ is arranged so as to overlap the upper side of the support portion 9. For the sake of explanation, the outer shape of the friction material portion 15 ′ is indicated by a dotted line, and the vibrator of the support portion 9 and the dodging spring mechanism are It is displayed so that the behavior can be understood.

5A is when the vibrator 11 'is at the center position of the movable range of the dovetail spring, and the horizontal position of the support portion 17 and the horizontal position of the vibrator 11' are the same position. .
At this time, the spring portion 18 has a shape in which two beams extend straight downward from the support portion 17.

  FIG. 5B is a diagram showing the friction material portion 15 ′ moved Hx in the right direction on the paper surface by the generated force of another vibrator. The vibrator 11 ′ is in frictional contact with the friction material portion 15 ′. Similarly, Hx moves to the right in the drawing. Since the spring portion 18 is a soft spring in the left-right direction on the paper, it is deformed so as not to obstruct the movement of the vibrator 11 '. As a result of the spring portion acting in this way, the friction material portion 15 ′ provided integrally with the moving body in a direction different from the direction in which the driving force of the vibrator 11 ′ is generated is loaded with the friction force of the contact portion. It becomes possible to move without.

FIG. 5C is a view showing the state where the friction material portion 15 ′ is moved Hx leftward in the drawing, and the spring portion 18 is deformed so as not to obstruct the movement of the vibrator 11 ′ as in FIG. 5B. ing.
FIG. 5D shows the case where the vibrator 11 ′ is at the center position of the movable operating range of the spring as in FIG. 5A, and the horizontal position of the support portion 17 and the horizontal position of the vibrator 11 ′. Are in the same position.

  FIG. 5E is a diagram showing a state in which the friction material portion 15 ′ is moved upward in the drawing by the vibrator 11 ′. Since the spring portion 18 is a hard spring in the vertical direction on the paper surface, the spring is not deformed and efficiently transmits the driving force Fy of the vibrator 11 ′ to the friction material portion 15 ′.

  FIG. 5 (f) is a diagram showing a state in which the friction material portion 15 'is moved downward in the drawing by the vibrator 11'. At this time, as in FIG. 5 (e), the spring portion 18 operates to transmit the driving force Fy of the vibrator 11 'as it is to the friction material portion 15' provided integrally with the moving body.

  FIG. 6 is a diagram in which the above-described dovetail spring mechanism is used in the vibration wave driving device of the present invention, and shows the operation when the moving body 4 moves in the X direction. In FIG. 6, the moving body 4 is arranged so as to overlap the upper side of the support portion 9, but for the sake of explanation, the outer shape of the moving body 4 is indicated by a dotted line so that the behavior of the vibrator of the support portion 9 and the dowel spring mechanism can be understood. Is displayed.

  The vibrators that generate driving force when moving the moving body 4 in the X direction are 11 (a) and 11 (c). The relationship between the direction of generation of the force of the vibrator of the vibrator 11 (a) and the dowel spring is shown in FIG. 5F, and the driving force Fa of the vibrator is transmitted to the moving body 4. The relationship between the direction of generation of the force of the vibrator of the vibrator 11 (c) and the dowel spring is as shown in FIG. 5E, and similarly, the driving force Fc of the vibrator is transmitted to the moving body 4.

  11 (b) and 11 (d) are transducers that do not generate force in the moving direction of the moving body, which was a conventional load when moving the moving body 4 in the X direction. The relationship between the direction of force generation of the vibrator of the vibrator 11 (b) and the dowel spring is as shown in FIG. 5 (c), and the spring portion prevents the friction force of the friction portion from being a load even when the moving body 4 moves. Is acting to deform. If the amount of movement of the moving body 4 in the X direction at this time is ΔX, if the amount of deformation of the spring portion is Hx, then Hx = ΔX.

  The relationship between the direction of generation of the force of the vibrator of the vibrator 11 (d) and the dovetail spring is as shown in FIG. 5 (b). Similarly, the frictional force of the vibrator that does not contribute to the drive acts so as not to become a load. The quantity Hx = ΔX.

  In FIG. 7, the moving body 4 is at the center of the X-direction operating range, but a deviation occurs from the center of the spring operating range (movable range) and the reference position of the moving body (center position of the moving range of the moving body). FIG. Then, after repeating the driving operation, the vibrators 11 (b) and 11 (d) are moved by the sliding of the friction portion, and the center of the spring operating range (movable range) and the reference position of the moving body (the moving range of the moving body). It is a figure which shows the operation | movement which recovers from the state which the shift | offset | difference produced with respect to (center position). FIG. 7A shows a state in which the center of the operating range of the spring is displaced from the position of the moving body due to the sliding of the friction part. Even though the moving body 4 is at the center position in the X-direction operation range, the vibrator 11 (b) is Hx = −ΔX1, 11 (d) is Hx = ΔX2, and the spring moves the vibrator laterally. It has stopped in the state. If it is further driven in the X direction in this state, the vibrator 11 (d) is moved further to the right side and exceeds the range in which the spring can be deformed. Furthermore, there arises a problem that the spring is plastically deformed and broken. Therefore, a driving force is applied to the vibrators 11 (a) and 11 (c) to move the moving body 4 to the center of the X direction driving. Thereafter, the driving of the vibrators 11 (a) and 11 (c) is stopped, and the vibrators 11 (b) and 11 (d) are perpendicular to the plane of the paper (a plane parallel to the surface where the vibrator and the moving body are in contact). Vibration T (vibrator 11 (b) is Tb and 11 (d) is Td). Here, the vibration in the vertical direction is the mode of FIG. 2B, and in order to generate only the vibration in the vertical direction, as can be seen from FIGS. 3 and 4, the vibrators 11 (b) and 11 (d) This is possible by applying an AC voltage having a phase difference of 0 ° to the drive voltages V1 and V2. When only such a vertical vibration is applied, a driving force is not applied to the moving body and the stopped state is maintained. However, since the frictional force is small at the contact portion between the moving body 4 and the vibrators 11 (b) and 11 (d), the vibrator that has been moved in the lateral direction is positioned at the center position of the movable range by the restoring force of the spring. Returned to As a result, as shown in FIG. 7B, the dovetail spring provided in the vibrators 11 (b) and 11 (d) is in a state where the spring is not deformed as shown in FIG. You can go back. As described above, when the moving body 4 is in the center position of the range where the dovetail spring is deformed, such as the first time when the moving body starts to be driven or after a certain number of times of driving, the vertical vibration is generated and the spring position is set to the initial position. The operation to return to the undeformed state is performed. By doing so, it is possible to solve the problem that the spring is out of the operating range and more stress than expected is applied or the spring is damaged.

  In this embodiment, when the moving body is at the center position in the X direction, the vibrators 11 (b) and 11 (d) are caused to vibrate in the direction perpendicular to the paper surface to correct the displacement of the moving body and the spring. When there is a moving body at the center position in the Y direction, it is also possible to correct the displacement between the moving body and the spring by causing the vibrators 11 (a) and 11 (c) to vibrate in the direction perpendicular to the paper surface. In addition, when there is a moving body at the center position in the XY direction, the vibrators 11 (a) to (d) are caused to vibrate in the direction perpendicular to the paper surface to correct the displacement between the moving body and the spring. It is also possible to center the operating range of the dowel spring provided on the vibrator.

  FIGS. 8A to 8H are diagrams for illustrating the operation mode of the second embodiment of the vibration wave driving device. The apparatus configuration is the same as that of the first embodiment, and the same components are assigned the same numbers. In the first embodiment, the purpose is to correct the relative displacement between the vibrator and the moving body within the movable range of the dovetail spring. However, the second embodiment can use the moving body in a range larger than the allowable operation range. This is an operation algorithm.

  In FIG. 8, the movable body 4 is arranged so as to overlap the upper side of the support portion 9, but for the sake of explanation, the outer shape of the movable body 4 is indicated by a dotted line so that the behavior of the vibrator of the support portion 9 and the dowel spring mechanism can be understood. I have to.

First, the operation relating to the portion of the vibrator 11 (c) in FIG. 8 will be described with reference to FIG.
In FIG. 9, the upper side of the figure shows the relationship between the vibrator 11 (c) and the moving body 4 as viewed from the direction of the arrow in FIG. 8 (a). 15 "is provided as a mark for understanding the movement of one portion of the friction material portion 15 '. The lower side of FIG. 9 is a vibration including a dovetail spring mechanism corresponding to the upper side operation. 9 (a) shows a state in which the center of the vibrator is located at the center position of the range in which the dovetail spring is deformed before starting the operation of the present embodiment. The position where the body (friction material portion 15 ′) and the vibrator 11 (b) are in contact with each other is 15 ″.

  FIG. 9B shows the direction in which the moving body generates the force of the vibrator 11 (b) by the driving force of the other vibrator, that is, the left-right direction (referred to as the X direction) orthogonal to the thickness direction of the paper surface of FIG. FIG. 6 is a diagram illustrating the state where the movable body and the vibrator are integrated with each other, and is moved by ΔX in the X direction.

  FIG. 9C shows a state in which the moving body and the vibrator are moved by ΔX by the operation of FIG. 9B, and are perpendicular to the contact surface of the vibrator 11 (b), that is, in the vertical direction on the paper surface in FIG. 9C. Vibration is generated. When the vibration in the vertical direction is generated on the contact surface, the frictional force between the moving body (friction material portion 15 ′) and the vibrator can be reduced.

  FIG. 9 (d) shows that the force that causes the deformation of the dovetail spring of the vibrator 11 (b) to return to the original state rather than the frictional force of the moving body and the vibrator due to the occurrence of the vertical vibration on the contact surface. Only the vibrator 11 (b) returns to the center position of the deformation range of the dovetail spring. However, since the moving body has the holding force of the contact portion with other vibrators, it remains in the state where it has moved ΔX. That is, in FIG. 9D, the moving body has moved by ΔX, but the vibrator has returned to the state of FIG. 9A. Accordingly, the moving body moves by ΔX by performing the operations of FIGS. 9A to 9D. If this operation is repeated twice, 3 × ΔX moving body can be moved by repeating 2 × ΔX three times.

  FIG. 8 is an operation of moving the moving body in the X direction using the above-described operation algorithm with the vibration type driving mechanism, and the vibrators 11 (a) and 11 (C) are vibrators that generate a driving force. , 11 (d) are vibrators that repeat the operation of FIG.

  8 and 10 are used to show an operation algorithm for operating the movable body in the X direction beyond the deformation range of the spring in the X direction. First, Fa is applied to the vibrator 11 (a), and Fc driving force is applied to 11 (c). Is generated. At this time, since the amount of movement in the Y direction is zero, almost no driving force is generated in the vibrators 11 (b) and 11 (d). (FIG. 10 Step (a) and FIG. 8 (a))

Next, a driving force is generated in the vibrators 11 (a) and 11 (C) so as to move the dowel spring displacements Hx = ΔX of 11 (b) and 11 (d). At this time, the moving body 4 has moved by the same amount of ΔX as the amount of displacement of the dovetail spring. (FIG. 10 Step (b) and FIG. 8 (b))
When vertical vibrations are generated in 11 (b) and 11 (d), there is a holding force of the vibrators 11 (a) and 11 (c), so that the position of the moving body remains as it is, and 11 (b) and 11 (d) The frictional force between the moving body and the moving body is reduced, and the displacement Hx of the dovetail spring is about to return from ΔX to zero, that is, the center position of the allowable operation range. (FIG. 10 Step (c) and FIG. 8 (c))
While the moving body has moved by ΔX, the displacement Hx = 0 of the dovetail spring 11 (b) and 11 (d) returns to the center position of the dowel spring operating range. (FIG. 10 Step (d) and FIG. 8 (d))
This is the operation to return the deformation of the dovetail spring after moving by a certain amount of movement.
This operation corresponds to the operation shown in FIGS. An operation of further moving from this state to ΔX, that is, 2 × ΔX in total is shown. Driving forces Fa and Fc are applied to the vibrators 11 (a) and 11 (c) so as to further move the ΔX moving body in the next operation, and the moving body is driven until it moves 2 × ΔX. At this time, since the amount of movement in the Y direction is zero, almost no driving force is generated in the vibrators 11 (b) and 11 (d). (FIG. 10 Step (e) and FIG. 8 (e))
Stop at the dowel spring displacement Hx = ΔX of 11 (b) and 11 (d). At this time, the moving body has moved 2 × ΔX in combination with ΔX of the displacement amount of the dovetail spring and the previous ΔX. (FIG. 10 Step (f) and FIG. 8 (f))
When vertical vibrations are generated in 11 (b) and 11 (d), there is a holding power of the vibrators 11 (a) and 11 (c). ), 11 (d) and the frictional force between the moving body is reduced and the displacement of the dovetail spring Hx = 0. (FIG. 10 Step (g) and FIG. 8 (g))
The movable springs 11 (b) and 11 (d) return to the center position of the operating range while the moving body has moved 2 × ΔX. (FIG. 10 Step (h) and FIG. 8 (h))
By the operation so far, the moving body has moved 2 × ΔX in the X direction, and the dovetail spring is located at the center position of the deformation range. Therefore, if such an operation is repeated n times, it is possible to move n × ΔX. That is, by repeating the operation of moving the ΔX moving body, it is possible to drive a long stroke with a mechanism using a dovetail spring.

  Although this embodiment shows an example of long stroke drive in the X direction, it is possible to drive in the Y direction as well, and in the oblique direction including XY, the above X direction drive and Y direction drive are combined. This can be realized.

  FIG. 11 is a diagram for illustrating the configuration of a third embodiment of the vibration wave driving device. In FIG. 11, the number of vibrators of the vibration wave actuator of the driving device in this configuration is four in the first embodiment, but three are arranged every rotation angle of 120 °.

  Reference numerals 11 (a) ′, 11 (b) ′, and 11 (c) ′ are driving vibrators, and the positions obtained by the position detection sensors 13 (a) to (c) are the same as in the first embodiment. According to the information, the driving force of the three vibrators is controlled by the control unit to move the moving body 4 in frictional contact with the vibrator.

  FIG. 11A shows a state in which the moving body 4 is at the center position of the operating range, and the dodging spring is not deformed. FIG. 11 (b) is a diagram showing a case where the moving body 4 is moved in the 135 ° direction when the X-axis direction is set to 0 °. The vibrator 11 (a) ′ has Fa and 11 (b) ′. Fb driving force is generated. Since the generation direction of the force of the vibrator of the vibrator 11 (C) ′ is a direction orthogonal to the moving direction of the moving body 4, the dowel spring mechanism is acting, and when the moving body moves by ΔX, the dowel spring displacement Hx = It turns out that it becomes ΔX and the friction load of a contact surface does not generate | occur | produce.

  FIG. 12 is an explanatory diagram of this embodiment. In FIG. 12, the movable body 4 is in the center of the operating range, but after repeating the driving operation, the vibrators 11 (a) to 11 (c) are moved to the center of the operating range of the spring and the moving body by sliding of the friction part. It is a figure which shows the operation | movement which restores from the state which the shift | offset | difference generate | occur | produced with respect to this position.

  FIG. 12A shows a state in which the center of the operating range of the spring is displaced from the position of the moving body due to the sliding of the friction portion, and the vibrator 11 is in spite of the moving body 4 being at the center position of the operating range. (A) is H = ΔX1, 11 (b) is H = ΔX2, 11 (C) is H = ΔX3, and the dowel spring stops in a state where the vibrator is moved in a direction orthogonal to the direction in which the force is generated. It has been done. If it tries to drive in this state, a certain spring will exceed the deformation range of a spring. Furthermore, there arises a problem that the spring is plastically deformed and broken. Therefore, after moving the movable body 4 to the center of driving, the vibrators 11 (a) to 11 (c) are subjected to vibration T in the direction perpendicular to the paper surface (the vibrator 11 (a) is Ta, 11 (b) is Tb, 11 (C) generates TC). Here, in order to generate only the vibration in the vertical direction, as can be seen from FIGS. 3 and 4, the drive voltages V1 and V2 of the vibrators 11 (a), 11 (b), and 11 (c) are about 0 °. This is possible by applying an alternating voltage of phase difference. When only such a vertical vibration is applied, a driving force is not applied to the moving body and the stopped state is maintained. Since the frictional force is small at the contact portion between the moving body 4 and the vibrators 11 (a) to 11 (C), the vibrator that has been moved in the lateral direction is moved to the center position of the movable range by the restoring force of the spring. As shown in FIG. 11B, the dovetail springs of the vibrators 11 (a) to 11 (c) can return to the state where the spring is not deformed as shown in FIG. 5 (a). As described above, when the moving body 4 is at the center position where the dodging spring is deformed (movable range) such as at the beginning of movement or after being driven a certain number of times, vertical vibration is generated and the spring position is set to the initial position. By performing the operation of returning to the undeformed state, it is possible to solve the problem that the spring is out of the operating range, causing more stress than expected, or being damaged. As described above, even when three vibrators are used, the load can be reduced by using the mechanism of the dovetail spring. In addition, when the positional relationship between the vibrator and the moving body is deviated during repeated driving as in the first embodiment, the spring is displaced by generating vibration in the direction perpendicular to the paper surface at the center position of the operation range. It is possible to correct and recover to the correct position.

  In the first to third embodiments, the vibrator is caused to vibrate perpendicular to the contact surface in order to correct the spring displacement. However, the driving force reduces the frictional force in the direction orthogonal to the operation direction. The same effect can be obtained by driving back and forth in the direction in which the force of the vibrator is generated in small increments.

4, 4 ′ moving body 8 elastic member 9, 9 ′ support portion 11 (a) to 11 (d) vibrator 11 ′ vibrator 12 ball 13 (a) to 13 (c) position detection sensor 14 (a) to 14 (C) Scale part 15 (a) to 15 (d) Friction part 17 Support part 18 Spring part 20 Piezoelectric element 100 Vibrator 106 Diaphragm 107 Piezoelectric element part 108 Projection part 201 Imaging device main body 202 Lens barrel 203 Imaging element 204 Movement Body 211-213 Vibrator 221-223 Position detection means 263P, 263y, 263R Angular acceleration sensor

Claims (10)

A vibrator having an electro-mechanical energy conversion element;
A support portion for supporting the vibrator,
A vibration wave driving device that excites vibration in the vibrator and moves a moving body that contacts the vibrator by a frictional force,
A moving mechanism that allows the vibrator to move in a second direction that intersects a first direction that the vibrator drives within a plane that is parallel to a surface that contacts the vibrator and the moving body. When,
And a control unit that performs a changing operation for changing a contact position between the vibrator and the moving body.   2. The vibration wave driving device according to claim 1, wherein the changing operation includes an operation of causing the vibrator to vibrate in a direction perpendicular to a surface where the vibrator and the moving body are in contact with each other.   3. The vibration wave driving device according to claim 1, comprising a plurality of the vibrators, wherein the plurality of vibrators include the moving mechanism and the control unit for at least one vibrator.   The plurality of vibrators include vibrators whose driving directions are different from each other, and the moving body is moved by combining driving forces in the different directions. The vibration wave drive device described in 1.   5. The moving mechanism includes a spring between the support portion and the vibrator having high rigidity in the first direction and low rigidity in the second direction. The vibration wave driving device according to any one of the above. A vibrator having an electro-mechanical energy conversion element;
A support portion for supporting the vibrator,
A driving method of a vibration wave driving device that excites vibrations in the vibrator and moves a moving body that contacts the vibrator by a frictional force,
A moving mechanism that allows the vibrator to move in a second direction that intersects a first direction that the vibrator drives within a plane that is parallel to a surface that contacts the vibrator and the moving body. When,
A control unit that performs a changing operation for changing a contact position between the vibrator and the moving body,
A first step of performing a first driving operation for generating a driving force in the first direction, and generating a vibration in a direction perpendicular to the plane to change a position between the vibrator and the moving body. A second process step for performing a second drive operation;
A method of driving a vibration wave driving device comprising: A plurality of the vibrators;
The vibration wave drive according to claim 6, wherein the first step includes a step of generating a driving force in the first direction by combining at least two driving forces of the plurality of vibrators. Device driving method. The first step;
The method for driving a vibration wave driving device according to claim 6, wherein the second step is repeated. A third step of moving the movable body to a reference position serving as a reference;
The driving of the vibration wave driving device according to claim 6, further comprising a fourth step of performing the second driving operation on at least one vibrator after the third step. Method.   The method for driving a vibration wave driving device according to claim 9, further comprising a fifth step of reciprocating along the direction in which the vibrator is driven after the third step.

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