JP2021100292A - Vibration wave motor and electronic apparatus including the same - Google Patents

Abstract

To provide a vibration wave motor or the like according to the present invention that suppresses the wear of a contact body when a vibrating body and the contact body are relatively moved, and suppresses the deviation of a position where the contact body is in contact with the vibrating body in a direction of the relative movement of the vibrating body and the contact body.SOLUTION: In a vibration wave motor, a protrusion portion has a contact portion on which a contact surface for pressure contact with a contact body is formed, and the contact portion has a tip surface having a first width in a first direction which is a direction of relative movement, and a second width in a third direction that is orthogonal to a second direction which is a pressure contact direction, and a non-tip surface that is obtained by removing the tip surface from the surface of the contact portion, and the first width is less than the second width, and in the non-tip surface, the first curvature which is the curvature on the virtual plane orthogonal to the third direction is the second curvature or more which is the curvature on the virtual plane orthogonal to the first direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vibration wave motor and an electronic device having the same.

Conventionally, a vibration wave motor that obtains an output by exciting vibration to a vibrating body formed by an elastic body and an electric-mechanical energy conversion element and relatively moving the elastic body and a contact body in contact with the elastic body. Proposed. As such a vibration wave motor, the configuration described in Patent Document 1 has been proposed.

The vibrating body 31 described in Patent Document 1 will be described. FIG. 15 is a perspective view of the vibrating body 31. The vibrating body 31 is formed by sticking an electric-mechanical energy conversion element 4 on one plane of a flat plate portion 5a of a substantially rectangular elastic body 5 and integrating them. Protrusions 5b are formed at two positions on the other plane of the elastic body 5, and contact portions 5c that come into contact with the contact body are formed at each end of these protrusions 5b.

The contact portion 5c is a portion where the vibrating body 31 and the contact body are relatively moved by pressure contact with a contact body (not shown). Therefore, a flat surface is formed in advance on the contact portion 5c, or an R surface of a spherical surface is formed, for example, when the contact portion 5c is manufactured. It is formed.

If the area of the plane formed on the contact portion 5c in advance or due to wear remains small, the pressure due to the pressure contact is large, so that the contact body wears rapidly. For this reason, it is desirable that the contact portion 5c is formed with a flat surface having a large area so that the wear of the contact body does not proceed rapidly, and the entire (not a part) of the flat surface is in contact with the contact body. ..

Japanese Unexamined Patent Publication No. 2015-80329 Japanese Unexamined Patent Publication No. 2008-125147

FIG. 19 shows an example of a pressurized contact state between the vibrating body 31 and the contact body 3 in the vibrating wave motor 1. The vibrating body 31 and the contact body 3 are brought into pressure contact with each other by a pressurizing means (not shown) such as a coil spring and a holding means. When the contact body 3 is used as a reference, the contact portion 5c of the vibrating body 31 is held at an angle of θx around the X axis with respect to the surface of the contact body 3 with which the contact portion 5c is in contact, as shown in FIG. May occur. This is because the pressing force by the pressurizing means is biased in the Y direction, or the parts such as the holding means and the inclination around the X axis occur due to the assembly accuracy. Further, depending on the number of protrusions 5b (for example, one), a state in which the plane formed on the contact portion 5c is held at an angle about the Y axis with respect to the surface of the contact body 3 may occur.

In such a state, the plane formed on the contact portion 5c of the vibrating body 31 operates in contact with the surface of the contact body near the edge of the end portion in the Y direction and the edge of the end portion in the X direction. Become. Therefore, since the contact portion 5c continues to be in contact with the contact body on a flat surface having a narrow area, the problem that the contact body wears rapidly cannot be solved. As a result, the desired performance cannot be obtained.

Next, the principle of generating elliptical motion in the contact portion 5c of the vibrating body 31 will be described.

In FIG. 15, the direction in which the two protrusions 5b are lined up (the direction in which the vibrating body 31 and the contact body are relatively moved) is defined as the X direction. Further, the direction orthogonal to the plane of the flat plate portion 5a (the direction in which the vibrating body 31 and the contact body are in pressure contact) is the Z direction. Further, the direction orthogonal to the X direction and the Z direction is defined as the Y direction. These X, Y, and Z directions represent a three-dimensional Cartesian coordinate system.

In the vibration wave motor described here, a plurality of desired vibration modes are excited by applying an AC voltage of a specific frequency to the electric-mechanical energy conversion element 4. Then, by superimposing these vibration modes, vibration for driving the vibration wave motor (relatively moving the vibrating body 31 and the contact body) is formed. FIG. 16 is a perspective view illustrating two bending vibration modes for exciting the vibrating body 31.

In the vibrating body 31 of FIG. 15, the vibrating body 31 is excited by the two bending vibration modes shown in FIGS. 16A and 16B. Both of these two bending vibration modes are bending vibration modes in the out-of-plane direction of the plate-shaped vibrating body 31. One vibration mode is a primary bending vibration mode (Mode-A) in which nodes and antinodes are generated in the Y direction of the vibrating body 31, and the other vibration mode is a secondary in which nodes and antinodes are generated in the X direction of the vibrating body 31. Bending vibration mode (Mode-B).

The size and shape of the vibrating body 31 are designed so that the resonance frequencies of the two vibration modes match or are close to each other.

The two protrusions 5b are arranged in the vicinity of the position that becomes the antinode of the vibration in the vibration of Mode-A (first bending vibration mode), and are caused by the vibration of Mode-A (first bending vibration mode). The two contact portions 5c reciprocate in the Z direction.

Further, the two protrusions 5b are arranged in the vicinity of the positions that serve as vibration nodes in the vibration of Mode-B (second bending vibration mode), and the vibration of Mode-B (second bending vibration mode). As a result, the two contact portions 5c perform a pendulum motion with the vibration node as a fulcrum. Therefore, the vibrating body 31 and the contact body move relative to each other in the X direction.

By simultaneously exciting and superimposing these two vibration modes (Mode-A and Mode-B) so that the vibration phase difference is close to ± π / 2, the two contact portions 5c move elliptical in the XZ plane. To do. By this elliptical motion, the vibrating body 31 (contact portion 5c) can be relatively moved (driving the vibrating body 31 or the contact body) with the contact body (not shown) in pressure contact.

The nature of the elliptical motion at the contact portion 5c of the vibrating body 31 will be described. In the following, one of the two protrusions will be described, but the other contact portion has the same effect, so the description will be omitted.

FIG. 17 shows an enlarged contact portion 5c located on the X direction side in FIG. The center of the plane formed on the contact portion 5c is designated as a point P1, and the positions separated from this point P1 in the X direction are designated as points P2 and P3. Further, the positions separated from the point P1 in the Y direction are designated as points P4 and P5.

FIG. 18 shows the results verified by the inventor of the present invention. In FIGS. 18 (a) to 18 (e), the elliptical motions at points P1, P2, P3, P4, and P5 shown in FIG. 17 are respectively displaced in the X direction (displacement in the X direction) on the horizontal axis. It is represented by a graph in which the vertical axis is the displacement in the Z direction (displacement in the Z direction).

As is clear from FIG. 18, the elliptical motion generated at the contact portion 5c is a state close to a perfect circle at the point P1 in FIG. 18, or an elliptical motion in which the directions of the major axis and the minor axis follow the X direction or the Z direction. Is. The state of this elliptical motion changes depending on how the input signal (AC signal) to be applied is given, but here, a typical state is shown.

In FIG. 18, as shown by points P2 and P3, as the position changes in the X direction from the point P1, the component in the Z direction in Mode-B (second bending vibration mode) increases, and the major axis and the minor axis of the elliptical motion become larger. The axis is tilted from the X and Z directions in FIG. 18, and the difference between the major axis and the minor axis becomes a large locus. The elliptical motion generated at points P2 and P3 is different from the elliptical motion generated at point P1 in the transmission efficiency of the force for relative movement between the vibrating body and the contact body from the vibrating body to the contact body (hereinafter, simply "transmission efficiency"). ) Will decrease.

On the other hand, the elliptical motion generated at points P4 and P5 is almost the same as the elliptical motion generated at point P1, and the decrease in transmission efficiency at points P4 and P5 (positions changed in the Y direction from point P1) is , It is smaller than the decrease in transmission efficiency at points P2 and P3 (positions changed in the X direction from point P1).

Therefore, it was found that it is desirable that the surface of the contact body is brought into contact with the plane formed on the contact portion 5c so that the position of the contact portion 5c from the center does not change in the X direction rather than the Y direction. ..

However, it is difficult to make such contact. This is because, as described above, the plane formed on the contact portion 5c may be held at an angle about the Y axis with respect to the surface of the contact body 3.

The present invention suppresses wear of the contact body when the vibrating body and the contact body are relatively moved, and suppresses the deviation of the position where the contact body is in contact with the vibrating body in the direction of relative movement between the vibrating body and the contact body. It is an object of the present invention to provide a vibration wave motor and the like.

The vibration wave motor of the present invention includes a vibrating body having an elastic body having a protrusion formed on one surface and an electric-mechanical energy conversion element fixed to the back surface of the one surface of the elastic body. A vibration wave motor including a contact body that makes pressure contact with the protrusion, and the vibrating body excites vibration to move the vibrating body and the contact body relative to each other. It has a contact portion on which a contact surface for pressure contact with the contact body is formed, and the contact portion has a first width in a first direction, which is a direction of relative movement, and the first direction and the addition. A tip surface having a second width in a third direction, which is a direction orthogonal to the second direction, which is a pressure contact direction, and a non-tip surface obtained by removing the tip surface from the surface of the contact portion. The first width is less than the second width, and the non-tip surface has a first curvature which is a curvature on a virtual plane orthogonal to the third direction. It is characterized in that it is equal to or greater than the second curvature, which is the curvature on the virtual plane orthogonal to the direction.

Further, the vibration wave motor of the present invention is a vibrating body having an elastic body having a protrusion formed on one surface and an electro-mechanical energy conversion element fixed to the back surface of the one surface of the elastic body. A vibration wave motor including a contact body that makes pressure contact with the protrusion, and the vibrating body that excites vibration to move the vibrating body and the contact body relative to each other. The contact portion has a contact portion on which a contact surface for pressure contact with the contact body is formed, and the contact portion has a first width in a first direction, which is a direction of relative movement, and the first direction and A tip surface having a second width in a third direction, which is a direction orthogonal to the second direction, which is a pressure contact direction, and a non-tip surface obtained by removing the tip surface from the surface of the contact portion. The first width is less than the second width, and the non-tip surface is a contact portion of the contact portion with respect to the first direction on a virtual plane orthogonal to the third direction. The first inclination, which is an inclination, is equal to or greater than the second inclination, which is the inclination of the contact portion with respect to the third direction on the virtual plane orthogonal to the first direction.

According to the vibration wave motor or the like of the present invention, the wear of the contact body when the vibrating body and the contact body are relatively moved is suppressed, and the vibrating body and the contact body are relatively moved at the position where the contact body is in contact with the vibrating body. It is possible to provide a vibration wave motor or the like that suppresses the deviation in the direction of causing the vibration.

It is a perspective view of the vibration wave motor which concerns on 1st Embodiment of this invention. It is a top view of the vibrating body which concerns on 1st Embodiment of this invention. It is (a) X direction sectional view and (b) Y direction sectional view of the protrusion and contact part of the vibrating body which concerns on 1st Embodiment of this invention. It is a figure which shows the cross-sectional shape of the contact part of the vibrating body which concerns on 1st Embodiment of this invention. It is a top view which shows the wear state of the vibrating body which concerns on 1st Embodiment of this invention. It is a top view of the vibrating body which concerns on 1st Embodiment of this invention. It is a figure which shows the cross-sectional shape of the contact part of the vibrating body which concerns on 1st Embodiment of this invention. It is a top view which shows the wear state of the vibrating body which concerns on 1st Embodiment of this invention. It is a perspective view of the vibrating body which concerns on 2nd Embodiment of this invention. It is a top view which shows the wear state of the vibrating body which concerns on 2nd Embodiment of this invention. It is a figure which shows the cross-sectional shape of the contact part of the vibrating body which concerns on 2nd Embodiment of this invention. It is a perspective view of another embodiment of the vibrating body which concerns on 2nd Embodiment of this invention. It is a perspective view of the vibrating body which concerns on 3rd Embodiment of this invention. It is (a) top view and (b) block diagram which shows the schematic structure of the electronic device (imaging apparatus) provided with a vibration wave motor. It is a perspective view of the vibrating body which concerns on the prior art. It is a front view of the vibration mode which excites a vibrating body which concerns on the prior art. It is a partial perspective view for demonstrating the position on the contact part of the vibrating body which concerns on the prior art. It is a figure which shows the elliptical motion which occurs at each position on the contact part of the vibrating body which concerns on the prior art. It is a figure which shows an example of the positional relationship between a vibrating body and a contact body which concerns on a prior art.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 is a perspective view showing a component of the vibration wave motor 1 according to the first embodiment of the present invention.

The basic configuration is the same as that of the vibration wave motor described in the prior art, and the vibration wave motor 1 is composed of the vibrating body 2 and the contact body 3. In FIG. 1, the vibrating body 2 and the contact body 3 are shown separately, but they are actually pressurized and in contact with each other (pressurized contact).

The vibrating body 2 has an electric-mechanical energy conversion element 4 and an elastic body 11. A piezoelectric element is used as the electric-mechanical energy conversion element, but a piezoelectric element other than the piezoelectric element may be used. Protrusions 11b are formed at two positions on one surface of the elastic body 11. A contact portion 11c is formed at each end of these protrusions 11b. An electric-mechanical energy conversion element 4 is fixed to the vibrating body 2 by adhesion or the like to the back surface of one surface (of the flat plate portion 11a) of the substantially rectangular elastic body 11. Then, the elastic body 11 and the electric-mechanical energy conversion element 4 are integrally formed. The contact portion 11c is a portion that makes pressure contact with the contact body 3 to drive the vibrating body 2 or the contact body 3 (relatively move the vibrating body 2 and the contact body 3). The shape of the contact portion 11c will be described later.

In FIG. 1, the direction in which the two protrusions 11b are lined up (the direction in which the vibrating body 2 and the contact body 3 are relatively moved) is defined as the X direction. Further, the direction orthogonal to the plane of the flat plate portion 5a (the direction in which the vibrating body 2 and the contact body 3 are in pressure contact with each other) is defined as the Z direction. Further, the direction orthogonal to the X direction and the Z direction is defined as the Y direction. These X, Y, and Z directions represent a three-dimensional Cartesian coordinate system.

The vibrating body 2 is excited by a plurality of (two in this case) bending vibration modes and used for driving. This vibration mode is the same as the description in the prior art, and the description is omitted.

The two protrusions 11b are formed so as to overlap the antinodes of the vibration of Mode-A (first bending vibration mode). Due to the vibration of Mode-A (first bending vibration mode), the two contact portions 5c reciprocate in the Z direction. Further, the two protrusions 11b are formed so as to overlap with the vibration nodes of Mode-B (second bending vibration mode). Due to the vibration of Mode-B (second bending vibration mode), the two contact portions 5c reciprocate in the X direction because they perform a pendulum motion with the vibration node as a fulcrum.

By simultaneously exciting and superimposing these two vibration modes (Mode-A and Mode-B), the two contact portions 5c make an elliptical motion in the XZ plane. This elliptical motion can drive a contact body (not shown) that has been pressure-contacted.

FIG. 2 is a plan view of the vibrating body 2.

The two protrusions 11b have a substantially elliptical column shape extending in the Z direction, and are formed so that the long axis is in the Y direction and the short axis is in the X direction. Similarly, the two contact portions 11c also have a substantially elliptical shape on the XY plane, and are formed so that the major axis is in the Y direction and the minor axis is in the X direction. At the center of the contact portion 11c, a tip surface 11d is formed along the XY surface in FIG. The tip surface 11d also has a substantially elliptical shape, and is formed so that the long axis is in the Y direction and the short axis is in the X direction.

The elliptical centers of the protrusion 11b, the contact portion 11c, and the tip surface 11d are formed so as to coincide with each other. Further, the center of the elliptical shape of the protrusion 11b, the contact portion 11c and the tip surface 11d is the antinode of the vibration of Mode-A (first bending vibration mode) and Mode-B (Mode-B) when viewed from the Z direction. It is formed so as to overlap the vibration node of the second bending vibration mode). The contact portion 11c is provided with an inclination in the X direction and the Y direction from the tip surface 11d.

FIG. 3 is a partial cross-sectional view showing the protrusion 11b, the contact portion 11c, and the tip surface 11d cut along the XZ plane and the YZ plane so as to include the center of the elliptical shape. FIG. 3A is a cross section (XZ cross section) cut along the XZ plane. FIG. 3B is a cross section (YZ cross section) cut along the YZ plane. The shape line when the surface of the contact portion 11c is represented by a cross-sectional shape passing through the center of the elliptical shape is defined as a shape line 11cx for the XZ cross section and 11cy for the YZ cross section. In the present embodiment, the contact portion 11c (shape line 11cx and shape line 11cy) forms an acute angle with respect to the X direction (first direction) and the Y direction (third direction). The inclined portion (non-line end surface) of the contact portion 11c is formed in a so-called toric surface shape having different curvatures in the X direction and the Y direction in FIG. The tip surface 11d is a surface shape that appears by removing a part of this toric shape along the XY surface. The symbol o in FIG. 3 indicates a position at the center of the contact portion 11c in the X direction and the Y direction, and this position is set as the center o. The center o is formed so as to coincide with the elliptical center of the protrusion 11b and the contact portion 11c described above.

The contact portion 11c is formed in a plate shape as shown in FIG. 3, and has an elastic action in the Z direction in FIG. This is because it has a desired elastic action when it is in pressure contact with the contact body 3.

As shown in FIG. 1, when the vibrating body 2 (projection portion 11b) and the contact body 3 are brought into pressure contact with each other, the contact portion 11c comes into contact with the contact body 3 at or near the center o. By operating the vibration wave motor 1, the contact portion 11c gradually wears in the Z direction due to the frictional operation. FIG. 5 is a plan view of the vibrating body 2 and shows a friction surface S11 (contact surface) formed when each contact portion 11c is worn.

FIG. 4 is a graph showing the shape lines 11cx and 11cy. The horizontal axis is the X direction (first direction), the Y direction (third direction), and the vertical axis is the Z direction (second direction). ). When the contact portion 11c is worn by the amount of dz in the Z direction from the tip surface 11d (center o) as shown in FIG. 4, the width of the friction surface S11 (contact surface) shown in FIG. 5 in the X direction is dx. And the width in the Y direction is dy.

The tip surface 11d is formed so that the width in the X direction (first width) in FIG. 1 is less than the width in the Y direction (second width). At this time, the curvature (first) of the non-tip surface (hereinafter, simply referred to as "non-tip surface") excluding the tip surface 11d from the surface of the contact portion 11c on the virtual plane (XZ plane) orthogonal to the Y direction. Curvature) is set to be equal to or greater than the curvature (greater than or equal to the second curvature) of the non-tip surface on the virtual plane (YZ plane) orthogonal to the X direction. That is, the ratio of the first curvature to the second curvature (first curvature / second curvature) is set to 1 or more (first curvature / second curvature ≥ 1). As a result, the friction surface S2 (contact surface) is likely to be formed in a rectangular shape with a long side along the Y direction and a short side along the X direction. Further, it is more preferable that the first curvature is larger than the second curvature. As a result, dy is always larger than dx. By forming in this way, the friction surface S11 (contact surface) is likely to be formed in an elliptical shape along the major axis in the Y direction and along the minor axis in the X direction. The ratio of the first curvature to the second curvature (first curvature / second curvature) is preferably 4 or less. Thereby, it is possible to prevent dx from becoming smaller than necessary for the relative movement between the vibrating body and the contact body.

Further, when viewed from the Z direction, the center o of the contact portion 11c is located at the center of the contact portion 11c, so that when viewed from the Z direction, the protrusion 11b and the friction surface S11 (contact surface) are It is easy to form so that the centers of each other are aligned. By forming the friction surface S11 (contact surface) of the vibrating body 2 with the contact body 3 in this way, there is a place where the elliptical motion of the friction surface S11 (contact surface) generated by exciting the vibrating body 2 is good. , Will be used to drive the oscillating wave motor 1 (relative movement between the oscillating body 2 and the contact body 3).

When the vibrating body 2 and the contact body 3 are combined so as to be relatively tilted around the X axis, in the initial state, the vibrating body 2 (contact portion 11c) comes into contact with the contact body 3 near the end portion of the tip surface 11d. It will be. For example, at the position of the point Q shown in FIG. 4, the vibrating body 2 (contact portion 11c) comes into contact with the contact body. The point Q is a position close to the center o, and it can be considered that a point equivalent to the center o is in contact with the point Q in practice. In this way, the vibrating body 2 and the contact body 3 can be brought into contact with each other at a desired position without being affected by the inclination of the vibrating body 2 and the contact body 3 around the X axis. FIG. 6 is a plan view of the vibrating body 24 for explaining another embodiment of the present embodiment.

The flat plate portion 16a of the elastic body 16 is formed with protrusions 16b at two positions, and contact portions 16c in contact with the contact body are formed at each end of each of the protrusions 11b. Further, when viewed from the Z direction, a tip surface 16d is formed at the center of the contact portion 16c.

FIG. 7 shows the contact portion 16c when the protrusion 16b, the contact portion 16c, and the tip surface 16d are cut along the XZ plane and the YZ plane so as to include the center of the elliptical shape when viewed from the Z direction. It is the figure which showed the shape of the surface by a graph. The shape line when the surface of the contact portion 16c is represented by a cross-sectional shape passing through the center of the elliptical shape is defined as a shape line 16cx for the XZ cross section and 16cy for the YZ cross section. In the present embodiment, the inclined portion (non-tip surface) of the contact portion 16c is formed so as to have a constant inclination in the X direction and the Y direction in the drawing. Further, in these examples, the inclination of the shape line 16cx with respect to the X direction on the XZ plane (first inclination θ ₁ ) and the inclination of the shape line 16cy with respect to the Y direction on the YZ plane (second inclination). θ ₂ ) has the same slope.

When the contact portion 16c is worn by the amount of dz in the Z direction from the center o as shown in the drawing, the width (first width) of the wear surface S12 (contact surface) shown in FIG. 8 in the X direction is dx. And the width in the Y direction (second width) is dy. The width of the tip surface 16d may be smaller in the X direction than in the Y direction. That is, it is more preferable that the first width is less than the second width. As a result, dy is always larger than dx. By forming in this way, the contact surface is likely to be formed in a rectangular shape in which the long side is along the Y direction and the short side is along the X direction.

The above has described the vibrating body that excites the two vibrating modes shown in FIG. 16, but the present invention is not limited to the vibrating body that uses such a vibrating mode. The present invention can be effective as long as the elliptical motion of the contact surface excites the vibration that changes in the relative movement direction between the vibrating body and the contacting body.

<Second embodiment>
FIG. 9 is a perspective view of the vibrating body 21 according to the second embodiment of the present invention. The description of the same parts as in the first embodiment will be omitted. Similar to the vibrating body 2 shown in FIG. 1, the two protrusions 12b overlap with the vibration antinodes of Mode-A (first bending vibration mode) and of Mode-B (second bending vibration mode). It is formed so as to overlap the vibration node.

The protrusion 12b is formed in a substantially rectangular shape in which the long side is along the Y direction and the short side is along the X direction when viewed from the Z direction. Contact portions 12c are formed on the upper surfaces of the two protrusions 12b in the Z direction. Like the protrusion 12b, the contact portion 12c is also formed in a substantially rectangular shape in which the long side is along the Y direction and the short side is along the X direction when viewed from the Z direction. The contact portion 12c includes a tip surface 12d formed along the XY surface in FIG. Similar to the protrusion 12b and the contact portion 12c, the tip surface 12d is also formed in a substantially rectangular shape with the long side along the Y direction and the short side along the X direction when viewed from the Z direction.

The center of the protrusion 12b, the contact portion 12c, and the tip surface 12d on the XY plane in FIG. 9 is represented by a point o. The position of the point o is near the antinode of the vibration of Mode-A (first bending vibration mode) and near the vibration node of Mode-B (second bending vibration mode) when viewed from the Z direction. The protrusion 12b, the contact portion 12c, and the tip surface 12d are formed so as to be at a certain position. The position of point o overlaps with the antinode of the vibration of Mode-A (first bending vibration mode) and overlaps with the vibration node of Mode-B (second bending vibration mode) when viewed from the Z direction. As described above, it is preferable that the protrusion 12b, the contact portion 12c and the tip surface 12d are formed.

An inclined surface 12x is formed in the X direction from the tip surface 12d, and an inclined surface 12y is formed in the Y direction. The inclined surface 12x (first surface) is a plane having an inclination obtained by rotating the XY plane in FIG. 9 only around the Y axis. The inclined surface 12y (second surface) is a plane having an inclination obtained by rotating the XY plane in FIG. 9 only around the X axis. The contact portions 12c (inclined surfaces 12x and 12y) form an acute angle with respect to the X direction (first direction) and the Y direction (third direction).

FIG. 10 shows a state of wear caused by operating the vibrating body 21 as a vibrating wave motor. The contact portion 12c is worn due to an operation through friction with a contact body (not shown), and a contact surface S2 (contact surface) is formed. The contact surface S2 (contact surface) has a substantially rectangular shape for the reason described later.

FIG. 11 is a graph showing the inclined surfaces 12x and 12y. The horizontal axis is the X direction (first direction), the Y direction (third direction), and the vertical axis is the Z direction (second direction). ). When the contact portion 12c is worn by the amount of dz in the Z direction from the tip surface 12d (center o) as shown in FIG. 11, the width of the friction surface S2 (contact surface) shown in FIG. 10 in the X direction is dx. And the width in the Y direction is dy.

The tip surface 12d is formed so that the width in the X direction (first width) in FIG. 9 is less than the width in the Y direction (second width). _{At this time, the inclination (first inclination θ 1} ) of the contact portion 12c (inclined surface 12x) with respect to the X direction on the virtual plane (XZ plane) orthogonal to the Y direction is changed to the virtual plane (YZ) orthogonal to the X direction. Make it equal to or greater than the inclination of the contact portion 12c (inclined surface 12y) with respect to the Y direction (second inclination θ _{2 or more) on the plane).} That is, the first ratio of inclination theta ₁ (first inclination theta _{1 /} second inclination theta ₂₎ to one or more (first inclination theta _{1 /} second inclination with respect to the second inclination theta ₂ theta ₂ ≧ 1). As a result, the friction surface S2 (contact surface) is likely to be formed in a rectangular shape with a long side along the Y direction and a short side along the X direction.

Further, it is preferable that the first inclination θ ₁ is made larger than the second inclination θ _2. As a result, dy is always larger than dx. By forming in this way, the friction surface S2 (contact surface) is more easily formed into a rectangular shape in which the long side is along the Y direction and the short side is along the X direction. The first inclination theta ₁ of the ratio of the second inclination theta ₂ (first inclination theta ₁ / second inclination theta ₂₎ is preferably 4 or less. Thereby, it is possible to prevent dx from becoming smaller than necessary for the relative movement between the vibrating body and the contact body.

In this way, similarly to the vibrating body 2 shown in the first embodiment, the friction surface S2 (contact surface) between the vibrating body 21 and the contact body 3 is formed, so that the vibrating body 2 is excited to generate the vibration. The portion of the friction surface S2 (contact surface) to be caused to have good elliptical motion is used for driving the vibration wave motor 1.

Although the two types of vibrating bodies (vibrating bodies 2 and 21) have been described above as the first and second embodiments, the present invention is not limited to these, and a form in which the same function can be obtained can be selected. For example, the curvature of the contact portion 11c is not limited to a constant curvature, and the contact portion 11c may have a quadric surface, a higher-order curved surface, or the like. Further, the inclination of the contact portion 12c is not limited to a constant inclination, and the contact portion 12c may have a shape such that the inclination changes in the middle.

The shapes of the protrusion 11b, the contact portion 11c and the tip surface 11d when viewed from the Z direction are the same, and the shapes of the protrusion 12b, the contact portion 12c and the tip surface 12d when viewed from the Z direction are the same. It is not limited to being the same. The shape of the protrusion, the contact portion, and the tip surface may be any combination of a rectangle, an oval, a rectangle with rounded corners, an ellipse, and the like.

Further, the protrusion and the elastic body are not limited to being one. FIG. 12 is a perspective view of the vibrating body 22 showing another form of the vibrating body according to the present embodiment. The vibrating body 22 is formed by an electric-mechanical energy conversion element 4, an elastic body 31 which is a plate component having a substantially rectangular shape, and two protruding members 32. The electric-mechanical energy conversion element 4 is attached to the elastic body 31, and the joint portion 32a of the two protrusion members 32 is fixed to the elastic body 31 by adhesion, welding, or the like on the opposite surface. A contact portion 32b and a tip surface 32d are formed on the protrusion member 32. The same effect can be obtained by forming the contact portion 32b and the tip surface 32d in the same shape as the contact portion 11c described with reference to FIG. 1, for example.

<Third embodiment>
FIG. 13 is a perspective view of the vibrating body 23 according to the third embodiment of the present invention. In the vibrating body 23, one protrusion 15b is formed at substantially the center of the elastic body 15. The protrusion 15b is formed so as to overlap the antinode of the vibration of Mode-A (first bending vibration mode) and overlap with the vibration node of Mode-B (second bending vibration mode). A contact portion 15c and a tip surface 15d are formed at the upper end of the protrusion 15b in the Z direction. The protrusion 15b, the contact portion 15c, and the tip surface 15d have the same shape as the protrusion 11b, the contact portion 11c, and the tip surface 11d shown in FIG. The elliptical motion of the contact portion 15c at this position during vibration excitation is the same as that described with reference to FIGS. 17 and 18, and the same effect can be obtained.

<Fourth Embodiment>
The vibration wave motor 1 described above can be used, for example, in an image pickup device (optical device) in which a lens group or an image pickup element is a driven member driven by a vibrating body or a contact body. Further, the stage can be used for various purposes such as an electronic device such as a linear motion stage device in which a driven member is driven by a vibrating body or a contact body. Here, as an example, an imaging device (optical device) in which the vibration wave motor 1 is arranged in the lens barrel and used to drive a lens group having one or a plurality of lenses will be described.

FIG. 14A is a top view showing a schematic configuration of an image pickup apparatus 700 including the vibration wave motor of the present invention. The image pickup device 700 includes a camera body 730 equipped with an image pickup element 710 and a power button 720. Further, the image pickup apparatus 700 includes a first lens group (not shown), a second lens group 320, a third lens group (not shown), a fourth lens group 340, and a vibration type drive device 620, 640 (vibration). A lens barrel 740 equipped with a wave motor) is provided. The lens barrel 740 is removable as an interchangeable lens from the camera body 730.

In the image pickup apparatus 700, the second lens group 320 (driven member) and the fourth lens group 340 (driven member) are driven by the two vibration wave motors 620 and 640, respectively. As the vibration wave motors 620 and 640, the vibration wave motor 1 described with reference to FIGS. 1 to 13 is used.

FIG. 14B is a block diagram showing a schematic configuration of an image pickup apparatus 700 including the vibration wave motor of the present invention. The first lens group 310, the second lens group 320, the third lens group 330, the fourth lens group 340, and the light amount adjusting unit 350 are arranged at predetermined positions on the optical axis inside the lens barrel 740. There is. The light that has passed through the first lens group 310 to the fourth lens group 340 and the light amount adjusting unit 350 is imaged on the image sensor 710. The image sensor 710 converts an optical image into an electric signal and outputs it, and the output is sent to the camera processing circuit 750.

The camera processing circuit 750 amplifies, gamma-corrects, and the like the output signal from the image sensor 710. The camera processing circuit 750 is connected to the CPU 790 via the AE gate 755, and is connected to the CPU 790 via the AF gate 760 and the AF signal processing circuit 765. The video signal subjected to the predetermined processing in the camera processing circuit 750 is sent to the CPU 790 through the AE gate 755, the AF gate 760, and the AF signal processing circuit 765. The AF signal processing circuit 765 extracts a high frequency component of the video signal, generates an evaluation value signal for autofocus (AF), and supplies the generated evaluation value to the CPU 790.

The CPU 790 is a control circuit that controls the overall operation of the image pickup apparatus 700, and generates a control signal for exposure determination and focusing from the acquired video signal. The CPU 790 controls the drive of the vibration wave motors 620, 640 and the meter 630 so as to obtain the determined exposure and the appropriate focus state, thereby adjusting the second lens group 320, the fourth lens group 340, and the amount of light. Adjust the position of the unit 350 in the optical axis direction.

Under the control of the CPU 790, the vibration type drive device 620 (vibration wave motor) moves the second lens group 320 in the optical axis direction. Further, the vibration type drive device 640 (vibration wave motor) moves the fourth lens group 340 in the optical axis direction. Further, the light amount adjusting unit 350 is driven and controlled by the meter 630.

The position of the second lens group 320 driven by the vibration wave motor 620 in the optical axis direction is detected by the first linear encoder 770, and the detection result is notified to the CPU 790 to drive the vibration wave motor 620. It has been fed back to.

Similarly, the position of the fourth lens group 340 driven by the vibration wave motor 640 in the optical axis direction is detected by the second linear encoder 775, and the detection result is notified to the CPU 790, so that the vibration wave motor It is fed back to the drive of 640. The position of the light amount adjusting unit 350 in the optical axis direction is detected by the aperture encoder 780, and the detection result is notified to the CPU 790, so that the position is fed back to the drive of the meter 630.

1 Vibration wave motor 2, 21, 22, 23 Vibrator 3 Contact 4 Electrical-mechanical energy conversion element 5, 11, 12, 13, 14, 15 Elastic body 5b, 11b, 12b, 13b, 14b, 15b Projection 5c , 11c, 12c, 13c, 14c, 15c Contact parts 5d, 11d, 12d, 13d, 14d, 15d Tip surface θ ₁ First inclination θ ₂ Second inclination S11, S12, S2 Friction surface (contact surface)

Claims (11)

A vibrating body having an elastic body having a protrusion formed on one surface and an electric-mechanical energy conversion element fixed to the back surface of the one surface of the elastic body.
A contact body that comes into pressure contact with the protrusion is provided.
A vibration wave motor that excites vibration by the vibrating body to move the vibrating body and the contact body relative to each other.
The protrusion has a contact portion on which a contact surface for pressure contact with the contact body is formed.
The contact portion has a first width in a first direction, which is a relative movement direction, and a third width, which is a direction orthogonal to the first direction and a second direction, which is a pressure contact direction. A tip surface having a second width in the direction and a non-tip surface obtained by removing the tip surface from the surface of the contact portion are provided.
The non-tip surface has a first curvature, which is a curvature on a virtual plane orthogonal to the third direction, and is equal to or greater than a second curvature, which is a curvature on a virtual plane orthogonal to the first direction. A vibration wave motor characterized by that. The vibration wave motor according to claim 1, wherein the first curvature is larger than the second curvature. A vibrating body having an elastic body having a protrusion formed on one surface and an electric-mechanical energy conversion element fixed to the back surface of the one surface of the elastic body.
A contact body that comes into pressure contact with the protrusion is provided.
A vibration wave motor that excites vibration by the vibrating body to move the vibrating body and the contact body relative to each other.
The protrusion has a contact portion on which a contact surface for pressure contact with the contact body is formed.
The contact portion has a first width in a first direction, which is a relative movement direction, and a third width, which is a direction orthogonal to the first direction and a second direction, which is a pressure contact direction. A tip surface having a second width in the direction and a non-tip surface obtained by removing the tip surface from the surface of the contact portion are provided.
The non-tip surface is on a virtual plane on which the first inclination, which is the inclination of the contact portion with respect to the first direction, is orthogonal to the first direction on the virtual plane orthogonal to the third direction. , A vibration wave motor characterized in that it is equal to or greater than the second inclination, which is the inclination of the contact portion with respect to the third direction. The vibration wave motor according to claim 3, wherein the first inclination is larger than the second inclination. The vibration wave motor according to claim 1 to 4, wherein the first width is less than the second width. The vibration wave motor according to claim 1 to 5, wherein the shape of the tip surface when viewed from the second direction is rectangular. The vibration wave motor according to claim 1 to 5, wherein the shape of the tip surface when viewed from the second direction is an ellipse. The vibration wave motor according to claim 1, wherein the vibration excited by the vibrating body is vibration in a plurality of bending vibration modes. The plurality of bending vibration modes include a first bending vibration mode in which a vibration node and a vibration antinode occur in the third direction of the vibrating body, and a vibration node and vibration in the first direction of the vibrating body. Including a second bending vibration mode, which causes the belly of
The vibration according to claim 8, wherein the protrusion is formed so as to overlap the vibration antinode of the first bending vibration mode and the vibration node of the second bending vibration mode. Wave motor. The vibration wave motor according to any one of claims 1 to 9,
An image pickup apparatus comprising the lens group or an image pickup element driven by the vibrating body or the contact body. The vibration wave motor according to any one of claims 1 to 9,
An electronic device comprising the vibrating body or a driven member driven by the contact body.

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