JP6742860B2 - Vibration type actuator and electronic equipment - Google Patents

Description

The present invention relates to a dynamic actuator and an electronic device, and more particularly to a configuration for supplying power to a vibrating body that constitutes a vibrating actuator and supporting the vibrating body.

A driven body is brought into pressure contact with a vibrating body formed by joining a piezoelectric element and an elastic body, and an AC voltage is applied to the piezoelectric element to excite vibration in the vibrating body to apply a friction driving force to the driven body. Then, a vibration type actuator is known which moves a vibrating body and a driven body relatively. As a method for supporting a vibrating body to reduce the size of the vibrating actuator, a configuration in which a flexible printed circuit board (hereinafter referred to as “FPC”) that supplies power to the vibrating body has a supporting function for supporting the vibrating body is disclosed in Patent Document 1 Have been proposed to.

FIG. 10 is a plan view showing a support structure of a vibrating body 950 that constitutes the vibration type actuator described in Patent Document 1. The FPC 952 is fixed to a casing or the like (not shown) at two fixing portions 952c provided at predetermined intervals in the longitudinal direction of the FPC 952. The vibrating body 950 is attached to the FPC 952 at approximately the center of the two fixing portions 952c. The extending direction of the conducting member 952d included in the FPC 952 is substantially parallel to the direction connecting the two fixing portions 952c.

Here, in the vibration-type actuator that extracts the frictional driving force, as the vibrating body 950 becomes smaller and the required driving force becomes smaller, the vibrating body 950 is required for pressure contact with the driven body (not shown). The pressure is small. As a result, the rigidity required for the support portion (the portion between the two fixing portions 952c) of the FPC 952 becomes small. Further, in the FPC 952, by shortening the distance from the fixed portion 952c to the vibrating body 950, it is possible to increase the spring constant with respect to the pressing force that brings the vibrating body 950 and the driven body into pressure contact. Therefore, the FPC 952 has lower rigidity than the metal member, but can function as a supporting member that sufficiently supports the vibrating body 950.

Further, since the FPC 952 which is a power feeding member functions as a supporting member and it is not necessary to provide a supporting member in addition to the power feeding member, the number of parts constituting the vibration type actuator can be reduced. Further, the rigidity of the pressing force acting on the support portion of the FPC 952 in the acting direction and the rigidity in the rotating direction of the shaft orthogonal to this acting direction are sufficiently low, so that the vibrating body 950 is attached to the contact surface of the driven body. By imitating the position of the contact surface, it is possible to reduce pressure unevenness on the contact surface. In this way, it is possible to reduce the size of the vibration-type actuator including the structure of the casing (not shown), and to stably support the vibration body 950.

JP-A-9-233868

The FPC 952 is mainly composed of a base member made of a resin film and a metal conductive member 952d, and the difference in rigidity between these two members is large. Therefore, when the vibrating body 950 is supported by the FPC 952, stress is concentrated on the conducting member 952d due to the pressing force applied to the vibrating body 950, and the conducting member 952d is disconnected, which may cause power supply failure. .. In particular, stress is likely to be concentrated on the supporting portion of the FPC 952 between the joint with the vibrating body 950 and the fixing portion 952c, and the conductive member 952d may be broken in the supporting portion.

Further, as the vibration body 950 becomes smaller, the second moment of area of the vibration body 950 becomes smaller. In this way, when the rigidity of the vibrating body 950 becomes small and the rigidity of the conducting member 952d made of copper foil or the like approaches the rigidity of the vibrating body 950, the conducting member for the mode shape of the vibration mode and the resonance frequency determined by the shape of the vibrating body 950. The influence of 952d becomes large. Therefore, it becomes necessary to add the configuration of the conducting member 952d to the driving of the vibrating body 950. Further, for example, when the FPC 952 is deformed such as stretched due to the stress applied to the FPC 952, the conductive member 952d is also similarly deformed, and the vibration state of the vibrating body 950 is also changed, so that the desired driving performance is obtained. May not be obtained.

It is an object of the present invention to provide a technique for suppressing the occurrence of power supply failure when driving a vibration type actuator and obtaining stable drive characteristics.

Vibration actuator according to the present invention, electrical - a vibrator having a mechanical energy conversion element and an elastic member, a support member for supporting the vibrating body, Bei example and a contact body which come in contact with the vibrator, the The support member includes a vibrating portion that is joined to the vibrating body, a plurality of first fixing portions that include a conducting member, and is fixed at a predetermined position, and a direction that is different from a direction from the vibrating portion toward the first fixing portion. A plurality of second fixing portions, a plurality of first supporting portions that connect the vibrating portion and the plurality of first fixing portions, and a portion that connects the vibrating portion and the plurality of second fixing portions. And a plurality of second support portions.

According to the present invention, it is possible to provide a vibration-type actuator that can suppress the occurrence of power supply failure and can obtain stable vibration characteristics.

3A and 3B are a schematic perspective view of a vibration type actuator according to the first embodiment and a schematic perspective view of a vibrating body forming the vibration type actuator. It is a figure explaining the vibration mode excited by the vibration body of the vibration type actuator which concerns on 1st Embodiment, and the electrode structure of a piezoelectric element. 3A and 3B are a side view and a rear view of the vibration type actuator according to the first embodiment. It is a perspective view explaining another vibration mode excited by the vibrating body which constitutes a vibration type actuator. It is a figure which shows schematic structure of the vibration type actuator which concerns on 2nd Embodiment. It is a figure which shows schematic structure of the vibration type actuator which concerns on 3rd Embodiment. It is a figure which shows schematic structure of the vibration type actuator which concerns on 4th Embodiment. It is an appearance perspective view of a microscope provided with a vibration type actuator. 3A and 3B are a schematic plan view and a block diagram of an image pickup apparatus including a vibration actuator. It is a top view which shows the conventional support structure of a vibrating body.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, a first embodiment of the present invention will be described. FIG. 1A is a perspective view showing a schematic configuration of a vibration type actuator 10 according to the first embodiment of the present invention. FIG. 1B is a perspective view showing a schematic configuration of a vibrating body 11 that constitutes the vibrating actuator 10. The vibration type actuator 10 includes a driven body 2, a vibrating body 11, an FPC (flexible printed circuit board) 12, and a backing material 13. The vibrating body 11 includes an elastic body 11a, a piezoelectric element 11b, and a protrusion 11c. For convenience of explanation, the X axis, Y axis, and Z axis shown in FIG. The Y-axis direction is the direction connecting the two protrusions 11c. The Z-axis direction is the protruding direction of the protrusion 11c, and is the thickness direction of the elastic body 11a and the piezoelectric element 11b. The X-axis direction is a direction orthogonal to both the Y-axis direction and the Z-axis direction, and when the driven body 2 is frictionally driven by the vibrating body 11, the driven body 2 and the vibrating body 11 are relatively moved. The direction of movement.

The FPC 12, which is a power feeding member that feeds power to the piezoelectric element 11b, has a structure in which the conducting member 12d is narrowed in the base member which is a two-layer sheet-shaped member in the Z-axis direction. For example, a resin material such as a sheet-shaped polyimide film is used for the base member, and a metal material such as copper foil is used for the conductive member 12d. The FPC 12 has a substantially cruciform shape, and includes two positions on the one side of the FPC 12 at the Y-axis direction end, one position at the X-axis direction end, and one position at a predetermined distance from the X-axis direction end. Backing material 13 which is a reinforcing member is fixed to a total of four places. On the other surface of the FPC 12 at a position substantially in the center of the position where the two backing materials 13 are fixed in the X-axis direction and substantially in the center of the position where the two backing materials 13 are fixed in the Y-axis direction. The vibrating body 11 is fixed. The details of the configuration of the FPC 12 will be described later.

The vibrating body 11 is supported by the base 3 by fixing the FPC 12 to the base 3 via the backing material 13. The base 3 is a component that forms a housing of an electronic device (not shown) on which the vibration actuator 10 is mounted. As described above, in the vibration type actuator 10, the FPC 12 has a function as a supporting member that supports the vibrating body 11 in addition to a function as a power supplying member that supplies power to the piezoelectric element 11b. Therefore, it is possible to reduce the number of parts and the number of assembling steps by eliminating the need for another part for supporting the vibrating body 11. The method of fixing the FPC 12 to the base 3 via the lining material 13 is not particularly limited, and known methods such as fixing with an adhesive, sandwiching with a pressing plate, bolt fastening, caulking, etc. may be used. it can.

For the substantially rectangular and flat elastic body 11a, for example, a metal material such as SUS420J2 which is martensitic stainless steel is preferably used. A piezoelectric element 11b, which is an electro-mechanical energy conversion element, is bonded to one surface of the elastic body 11a. The FPC 12 is joined to the surface of the piezoelectric element 11b opposite to the joint surface with the elastic body 11a, and thus the vibrating body 11 is supported by the FPC 12. The “substantially rectangular shape” means that it can be regarded as a substantially rectangular shape, and does not need to be a strictly rectangular shape due to a component tolerance, an assembly error, or the like.

The two protrusions 11c are arranged on the surface of the elastic body 11a opposite to the surface on which the piezoelectric element 11b is joined so as to protrude in the Z-axis direction, which does not face the piezoelectric element 11b, at predetermined intervals in the Y-axis direction. It is provided. The tip of the protrusion 11c makes pressure contact with the driven body 2. Note that FIG. 1A shows a state in which the driven body 2 and the protrusion 11 c are separated from each other for convenience, in order to illustrate at least a part of the vibrating body 11. As a method for bringing the protrusion 11c and the driven body 2 into pressure contact, a method of applying a pressing force (elastic force) from the driven body 2 to the protrusion 11c, or a driven body 2 from the FPC 12 via the vibrating body 11 is used. Any of the methods of applying a pressing force to can be used. In addition, a magnetic circuit is formed between the driven body 2 and the elastic body 11a, and the elastic body 11a and the driven body 2 are attracted to each other by a magnetic force, so that the protrusion 11c and the driven body 2 are brought into pressure contact with each other. You can also let it.

It is desirable to provide a contact portion having a desired friction coefficient and excellent wear resistance at the tip of the protrusion 11c. For example, a contact portion having a desired friction coefficient and wear resistance can be formed by forming the protrusion 11c integrally with the elastic body 11a by bending and then performing heat treatment or surface polishing. The method of forming the protrusion 11c is not particularly limited, and a method of forming by etching or plating, a method of preparing the elastic body 11a as a member separate from the elastic body 11a, and fixing the elastic body 11a by welding or the like can be used. Can be used. When the elastic body 11a, the protrusion 11c, and the contact portion are integrally formed, the number of assembling steps can be reduced as compared with the case where these are separately formed and joined, and the position of the protrusion 11c is reduced. Since it is not necessary to perform matching, it is possible to suppress variations between components.

In the vibration type actuator 10, by exciting two bending vibration modes in the vibrating body 11 with a predetermined phase difference, an elliptic motion that draws a locus in the same direction in the ZX plane is generated at the tip (contact portion) of the protrusion 11c. Then, the driven body 2 is frictionally driven by the protrusion 11c. The higher resonance frequency of the two bending vibration modes is “fa”, and the resonance frequency difference between the two bending vibration modes is “Δf”. In this case, the shape of the vibrating body 11 is determined such that the resonance frequencies of the two bending vibration modes are brought close to each other and the resonance frequency difference Δf becomes a desired value. Specifically, the resonance frequency difference Δf between the two bending vibration modes is set by setting the dimensions of the vibrating body 11 in the longitudinal direction (Y-axis direction), the lateral direction (X-axis direction), and the thickness direction (Z-axis direction). To approach the desired value. In the present embodiment, the shape of the vibrating body 11 is formed so that the resonance frequency difference Δf satisfies the relationship of “0<Δf<fa×0.15”.

FIG. 2A is a perspective view illustrating a first bending vibration mode which is one of the two bending vibration modes excited in the vibrating body 11. In the first bending vibration mode, nodal lines Y1 and Y2 occur. Since the first bending vibration mode is the vibration of the vibrating body 11 in the out-of-plane direction (Z-axis direction) with respect to the XY plane, the nodal lines Y1 and Y2 are the vibration displacements of the vibrating body 11 substantially in the Z-axis direction. Refers to the part that does not occur. The two protrusions 11c are provided at positions that are antinodes in the first bending vibration mode. Therefore, when the first bending vibration mode is excited in the vibrating body 11, the two protrusions 11c have tips at the tips thereof. Vibration that reciprocates in the Z-axis direction at the same phase is generated.

FIG. 2B is a perspective view illustrating a second bending vibration mode which is one of the two bending vibration modes excited in the vibrating body 11. In the second bending vibration mode, nodal lines X1, X2 and Y3 occur. Since the second bending vibration mode is also vibration in the out-of-plane direction (Z-axis direction) with respect to the XY plane of the vibrating body 11, the nodal lines X1, X2, Y3 are substantially the Z-axis direction in the vibrating body 11. Refers to the part where vibration displacement does not occur. The two protrusions 11c are provided on the nodal line Y3 of the second bending vibration mode, and therefore, when the second bending vibration mode is excited in the vibrating body 11, the two protrusions 11c are provided at the tips thereof. Vibration that reciprocates in the X-axis direction at the same phase is generated.

FIG. 2C is a plan view of the electrode pattern provided on the piezoelectric element 11b. The piezoelectric element 11b is an example of an electro-mechanical energy conversion element in which electrodes are formed on each surface of a substantially rectangular and plate-shaped piezoelectric body made of piezoelectric ceramics or the like, and the piezoelectric body is polarized in a predetermined direction. is there. The electrode pattern shown in FIG. 2C is provided on the joint surface of the piezoelectric element 11b with the FPC 12, and the common electrode (GND electrode) (not shown) is provided on the joint surface of the piezoelectric element 11b with the elastic body 11a. Has been.

The joint surface of the piezoelectric element 11b with the FPC 12 is divided into two in the X-axis direction by dividing the A-phase electrode portions 11b1 and B in the X-axis direction with the nodal line Y3 generated when the vibration of the second bending vibration mode is excited as a boundary. The phase electrode portion 11b2 is formed. In addition, a GND electrode portion 11b3 is formed at a substantially central portion of the joint surface of the piezoelectric element 11b with the FPC 12. The GND electrode portion 11b3 is electrically connected to a common electrode provided on the joint surface of the piezoelectric element 11b with the elastic body 11a through a through hole (not shown) penetrating the piezoelectric body in the Z-axis direction. The piezoelectric body in the portion where the A-phase electrode portion 11b1 and the B-phase electrode portion 11b2 are provided is polarized in the same direction in the Z-axis direction. The conduction to the common electrode formed on the joint surface of the piezoelectric element 11b with the elastic body 11a may be taken out from the surface of the elastic body 11a.

It is assumed that the AC voltage V1 applied to the A-phase electrode section 11b1 and the AC voltage V2 applied to the B-phase electrode section 11b2 have the same voltage value and frequency. When the alternating voltages V1 and V2 are input to the piezoelectric element 11b in the same phase under this condition, the expansion and contraction directions generated in the electrode regions of the A-phase electrode portion 11b1 and the B-phase electrode portion 11b2 are the same. Therefore, by bringing the frequencies of the AC voltages V1 and V2 close to the resonance frequency of the first bending vibration mode in which the expansion and contraction directions are the same in each electrode region and vibrating, the vibrating body 11 of the first bending vibration mode is generated. Vibration can be excited. Further, when the alternating voltages V1 and V2 are input to the piezoelectric element 11b in opposite phases, the expansion and contraction directions generated in the electrode regions of the A-phase electrode portion 11b1 and the B-phase electrode portion 11b2 are opposite. Therefore, by bringing the frequencies of the AC voltages V1 and V2 close to the resonance frequency of the second bending vibration mode in which the expansion and contraction directions are opposite in each electrode region and vibrating, the vibrating body 11 is operated in the second bending vibration mode. Vibration can be excited.

As described above, the shape of the vibrating body 11 is determined so that the resonance frequencies of the first bending vibration mode and the second bending vibration mode are close to each other. Therefore, when the phases of the AC voltages V1 and V2 having the same frequency as the input voltage are applied to the A-phase electrode portion 11b1 and the B-phase electrode portion 11b2 with a 90° shift, the first bending vibration mode and the second bending vibration mode are applied. The respective vibrations of are excited with a phase difference of 90°. As a result, an elliptical motion in the ZX plane can be generated at the tip of the protrusion 11c, and the driven body 2 that is in pressure contact with the tip of the protrusion 11c receives a frictional driving force from the protrusion 11c. Thereby, the vibrating body 11 and the driven body 2 can be relatively moved in the X-axis direction. By changing the voltage values of the AC voltages V1 and V2 and the input phase difference, it is possible to change the orbital shape of the elliptic motion generated at the tip of the protrusion 11c.

FIG. 3A is a side view of the vibration actuator 10. FIG. 3B is a rear view showing the vibration type actuator 10 with the base member on the side of the backing material 13 of the FPC 12 removed. The driven body 2 is not shown in FIGS. 3(a) and 3(b). The two protrusions 11c are arranged at positions that are substantially rotationally symmetrical with respect to an axis that passes through the center of gravity of the vibrating body 11 and that is substantially parallel to the pressing direction (Z-axis direction). Therefore, since the center of gravity of the vibrating body 11 is supported by the FPC 12 so as to face the pressing direction applied to the vibrating body 11, the posture of the vibrating body 11 can be stabilized.

The FPC 12 can be divided into five parts (regions), and broken lines for explaining these five parts are shown in FIG. 3(b). Specifically, the FPC 12 can be divided into five parts: a vibrating part 12a, a first fixing part 12c1, a second fixing part 12c2, a first supporting part 12b1 and a second supporting part 12b2. The vibrating portion 12 a is a portion of the FPC 12 that is joined to the piezoelectric element 11 b and vibrates together with the vibrating body 11. The first fixing portion 12c1 is a portion that fixes the FPC 12 to the base 3 via the lining material 13, and is provided at two locations with the vibrating body 11 arranged in the center and facing each other in the X-axis direction. The second fixing portion 12c2 is a portion that fixes the FPC 12 to the base 3 via the backing material 13, and is provided at two locations with the vibrating body 11 arranged in the center and facing each other in the Y-axis direction.

The first supporting portion 12b1 is a portion that connects the vibrating portion 12a and each of the two first fixing portions 12c1. The second supporting portion 12b2 is the vibrating portion 12a and each of the two second fixing portions 12c2. This is the part that connects and. Like the two protrusions 11c, the two first support portions 12b1 are arranged substantially in rotational symmetry with respect to an axis parallel to the Z axis that passes through the center of gravity of the vibrating body 11. Further, the two second support portions 12b2 are also arranged substantially in rotational symmetry with respect to an axis passing through the center of gravity of the vibrating body 11 and parallel to the Z axis. Thus, the center of gravity of the FPC 12 is supported by evenly receiving the reaction force applied to the vibrating body 11 at a total of four places, that is, the two first support portions 12b1 and the two second support portions 12b2. As a result, the vibrating body 11 is also supported by the center of gravity and the posture is stabilized.

The conductive member 12d of the FPC 12 is divided into a wiring portion having a power feeding function and a wiring portion having a GND function. Specifically, the conductive member 12d includes a first power supply wiring portion 12d1 connected to the A-phase electrode portion 11b1 of the piezoelectric element 11b, a second power supply wiring portion 12d2 connected to the B-phase electrode portion 11b2, and a GND electrode. It is divided into a GND wiring portion 12d3 connected to the portion 11b3. The first power feeding wiring portion 12d1, the second power feeding wiring portion 12d2, and the GND wiring portion 12d3 each vibrate from a terminal (not shown) connected to a power feeding circuit board (not shown) (from the left side of FIG. 3B). It extends toward the portion 12a. Further, the first power supply wiring portion 12d1, the second power supply wiring portion 12d2, and the GND wiring portion 12d3 have line-symmetrical shapes in the X-axis direction and the Y-axis direction between the two first fixing portions 12c1. doing.

Here, the symmetry of the shape of the conducting member 12d in the vibrating portion 12a when the XY plane is viewed from the Z-axis direction, and the shape of the conducting member 12d on the first support portion 12b1 extending from the vibrating portion 12a. The symmetry of is important. That is, since the shape of the conventional vibrating body is sufficiently larger than that of the FPC, the influence of the FPC on the vibration characteristic of the vibrating body (driving characteristic of the vibration type actuator) can be ignored. However, as the vibration body becomes smaller, the rigidity of the vibration body becomes smaller, so that the rigidity of the base member (film) that constitutes the FPC can be neglected. The difference in body rigidity is reduced. For example, the rigidity difference between the polyimide film as the base member and the vibrating body is so large that the joint between the vibrating body and the polyimide film is substantially equal to the free end of the vibrating body. However, the joint between the vibrating body and the conducting member, whose difference in rigidity is reduced, cannot be regarded as a substantially free end, and when vibration is excited in the vibrating body, part of the vibration energy permeates the joint. Come to do. Therefore, in the vibration-type actuator 10 as well, due to the miniaturization, the influence of the portion extending from the vibrating portion 12a in the conductive member 12d on the shape of the vibrating body 11 that determines the mode shape and the resonance frequency increases.

For this reason, it is necessary to regard the conductive member 12d in the first support portion 12b1 as a part of the vibrating body 11 as the vibrating body 11 is downsized. Therefore, from the viewpoint of giving the first support portion 12b1 the same symmetry as the vibrating body 11, line symmetry in the X-axis direction and the Y-axis direction between the two first fixing portions 12c1 as described above. The conductive member 12d having a general shape is provided. As a result, it is possible to excite the vibrating body 11 to vibrate in a desired bending vibration mode.

By the way, in the vibration type actuator described in Patent Document 1 described as the prior art, the supporting portion (between the two fixing portions 952c) of the FPC 952 exists only in one direction. In this case, when a pressing force is applied to the vibrating body 950 in the thickness direction (direction orthogonal to the paper surface of FIG. 10), this supporting force is received only by the support portion. Further, since the difference in rigidity between the resin-based material and the metal-based conducting member 952d forming the supporting portion of the FPC 952 is sufficiently large, the stress generated in the FPC 952 when the vibrating body 950 receives a pressing force causes the conducting member 952d with high rigidity. Concentrate on. As a result, the conductive member 952d of the FPC 952 may be broken in the supporting portion, and power supply failure to the piezoelectric element forming the vibrating body 950 may occur. Further, the FPC 952 may expand and plastically deform due to the pressure applied to the vibrating body 950, and at that time, the conductive member 952d also expands and deforms. As a result, the shape of the considered vibrating body 950 including the conducting member 952d is changed, and a desired vibration state cannot be obtained.

On the other hand, in the present embodiment, the vibrating body 11 having a rectangular shape is provided with symmetry having two symmetry axes (X axis and Y axis) that are orthogonal to each other in the XY plane, and the vibrating body 11 has the symmetry. The conducting member 12d also has symmetry having two axes of symmetry. The FPC 12 has two second supporting portions 12b2 connecting the second fixing portion 12c2 and the vibrating portion 12a, which are provided in the Y-axis direction substantially orthogonal to the extending direction of the conductive member 12d, and the vibrating body. The pressing force applied to 11 is received by the two second support portions 12b2. Therefore, the load applied to the first support portions 12b1 at the two places can be reduced by the second support portions 12b2 at the two places, and thus the disconnection and the stretch deformation of the conductive member 12d can be prevented.

Further, as shown in FIG. 3B, the length of the first support portion 12b1 in the X-axis direction (the distance from the vibrating portion 12a to the first fixed portion 12c1) is L1, and the length of the second support portion 12b2 in the Y-axis direction. The distance (distance from the vibrating portion 12a to the second fixed portion 12c2) is L2. In the present embodiment, the length L2 in the Y-axis direction is made sufficiently shorter than the length L1 in the X-axis direction, so that the Z constant in the second support portion 12b2 is greater than the spring constant in the Z-axis direction of the first support portion 12b1. The axial spring constant is sufficiently large. That is, with respect to the load applied to the FPC 12 due to the pressure applied to the vibrating body 11, the load applied to the second support portion 12b2 not involved in power feeding is increased and the load applied to the first support portion 12b1 is reduced. This makes it possible to more effectively prevent disconnection of the conductive member 12d at the first support portion 12b1. When a material having high rigidity such as metal wiring (metal foil, metal wire) is used (to be sandwiched between the base members of the FPC 12) in order to increase the spring constant of the second support portion 12b2, the material is the first material. It is desirable that the two support portions 12b2 and the vibrating portion 12a are not connected. This is because the metal wiring is connected to the vibrating portion 12a and the second supporting portion 12b2, and thus the apparent shape of the vibrating body 11 is changed, and a desired vibrating state may not be obtained.

As described above, in the vibration-type actuator 10, in the FPC 12 that is the power feeding member that also has the supporting function, the second fixing portion 12c2 and the second fixing portion 12c2 in the direction different from the direction in which the first fixing portion 12c1 and the first supporting portion 12b1 are arranged. The second support portion 12b2 is provided. That is, by supporting the vibrating body 11 in a plurality of different directions, it is possible to avoid the occurrence of power supply failure, stabilize the vibration characteristics of the vibrating body 11, and realize further downsizing and cost reduction. be able to. Further, by providing the first fixing portion 12c1 and the second fixing portion 12c2 with the backing material 13 having sufficiently higher rigidity than the first supporting portion 12b1 and the second supporting portion 12b2, it is possible to reduce the vibration transmitted through the conducting member 12d. It can be shielded by the first fixing portion 12c1 and the second fixing portion 12c2. This makes it possible to shield the vibration transmission regardless of the method of fixing the FPC 12, and thus the vibration state of the vibrating body 11 can be further stabilized.

Since the conducting member 12d in the vibrating portion 12a is integrated with the vibrating body 11, it has less influence on the vibrating state of the vibrating body 11 than the conducting member 12d in the first supporting portion 12b1. However, it is desirable that the wiring shape in the vibrating portion 12a is also line-symmetrical with respect to each of the two axes of symmetry of the vibrating body 11. Therefore, in the vibrating portion 12a, the base member of the FPC 12 is opened so that the conductive member 12d is brought into contact only with the portion to be electrically connected to the A-phase electrode portion 11b1, the B-phase electrode portion 11b2, and the GND electrode portion 11b3 of the piezoelectric element 11b. Let As a result, it becomes possible to perform power supply while avoiding a short circuit while maintaining the symmetry of the wiring shape. In addition, since the difference in rigidity between the base members forming the FPC 12 between the first support portion 12b1 and the second support portion 12b2 is small, the vibration state of the vibrating body 11 may change due to the vibration transmission from the conductive member 12d to the base member. Conceivable. Therefore, it is desirable that the shape of the base member of the FPC 12 in the first support portion 12b1 and the second support portion 12b2 also has the same symmetry as the shape of the vibrating body 11.

In this embodiment, an AC voltage is applied to the A-phase electrode portion 11b1, the B-phase electrode portion 11b2, and the GND electrode portion 11b3 of the piezoelectric element 11b to excite vibrations in the first bending vibration mode and the second bending vibration mode. The configuration has been described. However, the present invention is not limited to this, and when a vibration mode that excites vibration in the vibrating body 11 is used by floating drive or the like, the piezoelectric element 11b does not necessarily have to be provided with the GND electrode portion 11b3. In addition, an elliptical motion may be generated at the tip of the protrusion 11c by using a vibration mode other than the combination of the first bending vibration mode and the second bending vibration mode, and the third bending vibration mode and the fourth bending vibration mode may be used. The combination of bending vibration modes will be described below.

FIG. 4A is a perspective view illustrating a third bending vibration mode excited in the vibrating body 51 for frictionally driving the driven body 2. 4B is a perspective view illustrating the fourth bending vibration mode excited in the vibrating body 51 at the same time as the third bending vibration mode. Exciting the vibration of the third bending vibration mode in the vibrating body 51 causes vibration displacement in the Z-axis direction at the tip of the protrusion 51c. Further, by exciting the vibration in the fourth bending vibration mode in the vibrating body 51, a vibration displacement in the X-axis direction occurs at the tip of the protrusion 51c. Of the resonance frequencies of the third bending vibration mode and the fourth bending vibration mode, the higher resonance frequency is “fa′” and the resonance frequency difference is “Δf′”. In this case, the shape of the vibrating body 51 is designed so that the relationship of “0<Δf′<fa′×0.15” is satisfied.

Vibrations in the third bending vibration mode and vibrations in the fourth bending vibration mode are simultaneously excited in the piezoelectric element included in the vibrating body 51, for example, by shifting the phase by 90 degrees. As a result, an elliptic motion in the ZX plane can be generated at the tip (contact portion) of the protrusion 51c, and the driven body 2 (not shown) is frictionally driven in the X-axis direction to drive the driven body 2 And the vibrating body 51 can be relatively moved in the X-axis direction. At this time, the vibrating actuator is configured by using a power feeding member having a supporting function that is divided into a vibrating portion, a first fixing portion, a second fixing portion, a first supporting portion, and a second supporting portion like the FPC 12. It is possible to obtain the same effect as that obtained by the vibration type actuator 10.

FIG. 5 is a perspective view showing a schematic configuration of the vibration type actuator 20 according to the second embodiment of the present invention. The vibrating body 21 forming the vibrating actuator 20 is the same as the vibrating body 11 forming the vibrating actuator 10. Therefore, the elastic body 21a, the piezoelectric element 21b, and the protruding portion 21c forming the vibrating body 21 correspond to the elastic body 11a, the piezoelectric element 11b, and the protruding portion 11c forming the vibrating body 11, respectively. Although the driven body 2 is not shown in FIG. 5, the driven body 2 is arranged so as to be in pressure contact with the upper surface of the protrusion 21c in the Z-axis direction in the Z-axis direction.

The FPC 22 has a conduction member 22d including a first power supply wiring part 22d1, a second power supply wiring part 22d2, and a ground wiring part 22d3. The wiring shape of the conducting member 22d in the FPC 22 is the same as the wiring shape of the conducting member 12d in the FPC 12. The vibrating portion of the FPC 22, the two first fixing portions, and the two first connecting portions are connected to each other in the same manner as the vibrating portion 12a of the FPC 12, the two first fixing portions 12c1 and the two first connecting portions 12b1. It is provided in the extending direction of the member 22d. The FPC 22 is fixed to the base 3 via the lining material 23 at the first fixing portion. The backing material 23 is equivalent to the backing material 13.

The second fixing portion of the FPC 22 corresponding to the second fixing portion 12c2 of the FPC 12 has a XY plane (bonding surface between the FPC 22 and the backing material 23) of the first fixing portion as a reference surface, and is located in the Z-axis direction from the reference surface. It is provided in the negative direction (base 3 side). As a result, the FPC 22 is fixed to the ZX surface of the base 3 via the backing material 23 in the second fixing portion, and thus the second support portion of the FPC 22 extends in the Y-axis direction and then extends in the Z-axis direction. The shape (shape) extends in the negative direction.

For example, when a pressing mechanism that presses the protrusion 21c against the driven body 2 (not shown) in the positive Z-axis direction (to the driven body 2 side) by using the attractive force of a magnet is used, Since the fixed portion is provided in the negative direction of the Z-axis direction, the load applied to the second support portion is in the pulling direction. Therefore, the strength of the second support portion of the FPC 22 can be made larger than that of the second support portion 12b2 of the FPC 12. Further, since the space for providing the second fixing portion does not expand in the Y-axis direction, the vibration type actuator 20 can be downsized as compared with the vibration type actuator 10.

FIG. 6A is a perspective view showing a schematic configuration of the vibration type actuator 30 according to the third embodiment of the present invention. FIG. 6B is a plan view illustrating the configuration and wiring shape of the FPC 32 that constitutes the vibration actuator 30. The vibration type actuator 30 includes a vibrating body 31, an FPC 32, and a backing material 33. The vibrating body 31 is the same as the vibrating body 11 constituting the vibrating actuator 10 according to the first embodiment. Therefore, the driving method of the vibrating body 31 (bending vibration mode to be excited), the mode of frictional driving of the driven body 2 (not shown) by the vibrating body 31 and the like are the same as those in the first embodiment, and redundant description will be omitted.

In the vibration type actuator 30, as the backing material 33, one having a rectangular frame shape is used. The backing material 33 can be regarded as the four backing materials 13 used in the vibration type actuator 10 integrated in a rectangular frame shape. The lining material 33 is attached to the base 3 (not shown). Similar to the FPC 12, the FPC 32 can be divided into five parts, that is, a vibrating part 32a, a first fixing part 32c1, a second fixing part 32c2, a first supporting part 32b1 and a second supporting part 32b2. FIG. 6B shows broken lines for explaining these five parts (regions).

In the vibration type actuator 30, as in the first embodiment, the FPC 32, which is a power feeding member having a supporting function, is provided with the first supporting portion 32b1 and the second supporting portion 32b2. As a result, the load applied to the first support portion 32b1 due to the pressure applied to the vibrating body 31 is reduced by the second supporting portion 32b2, occurrence of power supply failure is avoided, and the vibration state of the vibrating body 31 is stabilized. Can be transformed into In addition, since the first fixing portion 32c1 and the second fixing portion 32c2 are integrated by the lining material 33, there is a case where the first fixing portion 12c1 and the second fixing portion 12c2 are independent as in the vibration actuator 10. Differently, it is possible to enhance the positioning accuracy when mounting on the base 3.

The functions of the conducting members 32d1, 32d2, 32d3 provided in the FPC 32 are the same as those of the first power supply wiring part 12d1, the second power supply wiring part 12d2, and the GND wiring part 12d3. In the FPC 32, the conducting members 32d1, 32d2, 32d3 are routed to the vibrating portion 32a via the first fixing portion 32c1 and the second fixing portion 32c2 and the two first supporting portions 32b1. Accordingly, the electrical connection of the conducting members 32d1, 32d2, 32d3 to the piezoelectric element of the vibrating body 31 can be maintained through the other first support portion 32b1 even if the one first support portion 32b1 is broken. Therefore, the occurrence of power supply failure can be more effectively avoided.

FIG. 7A is a perspective view showing a schematic configuration of the vibration type actuator 40 according to the fourth embodiment of the present invention. FIG. 7B is a rear view showing the vibration type actuator 40 with the base member on the side of the backing material 43 of the FPC 42 removed. The vibration type actuator 40 includes a vibrating body 41, an FPC 42, and a backing material 43. The vibrating body 41 is the same as the vibrating body 11 configuring the vibration-type actuator 10 according to the first embodiment. The backing material 43 is the same as the backing material 33 that constitutes the vibration-type actuator 30 according to the third embodiment. The wiring shapes of the conductive members 42d1, 42d2, 42d3 included in the FPC 42 are the same as the wiring shapes of the first power feeding wiring portion 12d1, the second power feeding wiring portion 12d2, and the GND wiring portion 12d3 of the FPC 12. Similar to the FPC 12, the FPC 42 can be divided into five parts, namely a vibrating part 42a, a first fixing part 42c1, a second fixing part 42c2, a first supporting part 42b1 and a second supporting part 42b2. FIG. 7B shows broken lines for explaining these five parts (regions).

The vibration type actuator 40 has a first support portion 42b1 and a second support portion 42b2 integrally formed as compared with the vibration type actuator 30 in which the first support portion 32b1 and the second support portion 32b2 are separately formed. It is characterized by In other words, the FPC 42 has a structure that does not have the opening that the FPC 32 has. When the first support portion 32b1 and the second support portion 32b2 are separated as in the third embodiment, a constant gap is required between the end portion of the FPC 32 and the conductive members 32d1 to 32d3, and thus the overall shape Tends to grow. On the other hand, in the FPC 42, by integrally forming the first support portion 42b1 and the second support portion 42b2 without providing an opening, processing becomes easy and the vibration-type actuator 40 as a whole can be downsized. Can be realized.

Next, an electronic device including the vibration-type actuator 10 according to the first embodiment of the present invention will be described by taking a microscope and an imaging device. However, the vibration type actuator 10 is not limited to the application to these, and can be widely applied to electronic devices including components that require positioning by driving.

FIG. 8 is an external perspective view of the microscope 500 including the vibration actuator 10. The microscope 500 includes an image pickup unit 530 including an image pickup element and an optical system, an automatic stage unit 510 having a stage 520 which is a driven body and is movably arranged on a base in an XY plane, and a base plate 540. With. A control device 550 that controls driving of the vibration-type actuator 10 including control of power supply to the piezoelectric element 11b is arranged on the base plate 540. The control device 550 may be provided in the image capturing unit 530. In the microscope 500, at least two vibrators 11 are used, at least one vibrator 11 is used for driving the stage 520 in the X-axis direction, and at least one other vibrator 11 is used for the Y-axis of the stage 520. Used for driving in the direction.

When an observation object is placed on the upper surface of the stage 520 and an enlarged image is captured by the image capturing unit 530 and the observation range is wide, the automatic stage unit 510 is driven to move the stage 520 to the X-axis direction. The object to be observed is moved by moving it in the Y-axis direction. Thus, by photographing a large number of photographed images and combining the photographed images by image processing by a computer (not shown), one observation image having a wide observation range and high definition can be obtained.

FIG. 9A is a top view showing a schematic configuration of the image pickup apparatus 700. The image pickup apparatus 700 includes a camera body 730 having an image pickup element 710 and a power button 720. Further, the imaging device 700 includes a lens barrel 740 having a first lens group (not shown), a second lens group 820, a third lens group (not shown), a fourth lens group 840, and vibration type driving devices 620 and 640. Equipped with. The lens barrel 740 can be attached to and detached from the camera body 730 as an interchangeable lens, and the lens barrel 740 suitable for a subject to be photographed can be attached to the camera body 730. In the imaging device 700, the two vibration type driving devices 620 and 640 drive the second lens group 820 and the fourth lens group 840, respectively.

Although the detailed configuration of the vibration type drive device 620 is not shown, the vibration type drive device 620 includes an annular driven body, a vibrating body 11 for rotating the driven body, and a drive circuit for the vibrating body 11. Have. For example, the three vibrating bodies 11 are arranged at equal intervals in the circumferential direction of the annular base, and in each vibrating body 11, the line connecting the two protrusions 11c is normal to the same circumference. It is supported by the FPC 12 and supported by the base via the lining material 13. With the driven body and the protrusion 11c of the vibrating body 11 in pressure contact with each other in the optical axis direction, the driven body and the base are arranged such that their radial directions are substantially orthogonal to the optical axis of the lens barrel 740. It is arranged in the lens barrel 740. In the vibration-type driving device 620, the driven body is rotated around the optical axis, and the rotational output of the driven body is converted into a linear motion in the optical axis direction via a cam, a gear, or the like (not shown), whereby the second lens is moved. The group 820 is moved in the optical axis direction. The vibration type drive device 640 has the same configuration as the vibration type drive device 620, and thus moves the fourth lens group 840 in the optical axis direction. The vibrating body 11 can drive the driven body 2 in one direction (X-axis direction). Therefore, the vibrating body 11 is arranged so that the X-axis direction (short side direction) of the vibrating body 11 is parallel to the optical axis direction of the lens barrel 740, and the lens holding member for holding the lens is used as the driven body. The holding member may be directly driven in the optical axis direction.

FIG. 9B is a block diagram showing a schematic configuration of the image pickup apparatus 700. The first lens group 810, the second lens group 820, the third lens group 830, the fourth lens group 840, and the light amount adjustment unit 850 are arranged at predetermined positions on the optical axis inside the lens barrel 740. The light that has passed through the first lens group 810 to the fourth lens group 840 and the light amount adjustment unit 850 forms an image on the image sensor 710. The image sensor 710 converts the optical image into an electric signal and outputs the electric signal, and the output is sent to the camera processing circuit 750.

The camera processing circuit 750 performs amplification and gamma correction on 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 also 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 the 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 determining exposure and focusing from the acquired video signal. The CPU 790 controls the driving of the vibration type driving devices 620 and 640 and the meter 630 so that the determined exposure and an appropriate focus state are obtained, and thus the second lens group 820, the fourth lens group 840, and the light amount adjustment unit. The optical axis position of 850 is adjusted. Under the control of the CPU 790, the vibration type driving device 620 moves the second lens group 820 in the optical axis direction, the vibration type driving device 640 moves the fourth lens group 840 in the optical axis direction, and the light amount adjusting unit 850 is a meter. Drive control is performed by 630.

The position in the optical axis direction of the second lens group 820 driven by the vibration type driving device 620 is detected by the first linear encoder 770, and the detection result is notified to the CPU 790 to be fed back to the driving of the vibration type driving device 620. .. Similarly, the position of the fourth lens group 840 in the optical axis direction driven by the vibration type driving device 640 is detected by the second linear encoder 775, and the detection result is notified to the CPU 790 to drive the vibration type driving device 640. To be fed back. The position of the light amount adjustment unit 850 in the optical axis direction is detected by the diaphragm encoder 780, and the detection result is notified to the CPU 790, and is fed back to the drive of the meter 630.

When the vibration type actuator 10 or the like described in the first embodiment is used for the purpose of moving a predetermined lens group of the imaging device 700 in the optical axis direction, a large holding force can be obtained even when the lens group is stopped. Accordingly, even if an external force acts on the lens barrel 740 and the camera body 730, it is possible to prevent the lens group from being displaced. When the lens barrel 740 has a built-in camera shake correction lens, the vibrating body 11 can be used as a camera shake correction unit that moves the camera shake correction lens in an arbitrary direction within a plane orthogonal to the optical axis. In that case, one or a plurality of vibrations driving the lens holding member in each direction so that the lens holding member holding the image stabilizing lens can be moved in two directions orthogonal to each other in a plane orthogonal to the optical axis direction. Place the body 11. The image stabilization unit may be configured to move the image sensor 710 built in the camera body 730 in an arbitrary direction within a plane orthogonal to the optical axis, instead of driving the image stabilization lens.

The present invention has been described in detail above based on its preferred embodiments, but the present invention is not limited to these specific embodiments, and various embodiments within the scope not departing from the gist of the present invention are also included in the present invention. included. Furthermore, each of the above-described embodiments is merely an example of the present invention, and the embodiments may be combined as appropriate. In the above embodiment, the elliptical motion is generated by combining the two vibration modes on the protrusion of the vibrating body, but a method of utilizing the inertial drive by using only one vibration mode may be used. Further, although the configuration having the two protrusions 11c like the vibrating body 11 has been taken up, the driven body 2 can be frictionally driven if there is at least one protrusion 11c, and one protrusion in this case is It may be provided at the center of the XY plane of the elastic body 11a and a suitable vibration mode may be selected.

2 Driven body 3 Base 10, 20, 30, 40 Vibration type actuator 11, 21, 31, 41 Vibration body 11a Elastic body 11b Piezoelectric element 11c Projection part 12, 22, 32, 42 FPC (flexible printed circuit board)
12a, 32a, 42a Vibrating part 12b1, 32b1, 42b1 1st support part 12b2, 32b2, 42b2 2nd support part 12c1, 32c1, 42c1 1st fixing part 12c2, 32c2, 42c2 2nd fixing part 12d Conducting member 13, 23, 33,43 Lining material

Claims (14)

A vibrating body having an electro-mechanical energy conversion element and an elastic body;
A support member for supporting the vibrating body,
E Bei and a contact body which come in contact with the vibrating body,
The support member is
A vibrating section joined to the vibrating body,
A plurality of first fixing portions including a conductive member and fixed at predetermined positions;
A plurality of second fixing portions provided in a direction different from the direction from the vibrating portion to the first fixing portion;
A plurality of first supporting portions that connect the vibrating portion and the plurality of first fixing portions,
A vibration-type actuator, comprising: a plurality of second support parts that connect the vibrating part and the plurality of second fixing parts. The support member is a flexible printed board that is joined to the electro-mechanical energy conversion element and supplies power to the electro-mechanical energy conversion element.
The vibration-type actuator according to claim 1, wherein the conductive member is provided in a direction connecting at least the plurality of first supporting portions and the plurality of first fixing portions through the vibrating portion. The vibration type actuator according to claim 2, wherein the flexible printed circuit board has a structure in which the conductive member is sandwiched between sheet-shaped members made of resin having a rigidity lower than that of the conductive member. The spring constant of the second support part is larger than the spring constant of the first support part in a direction in which the vibrating body receives a pressing force for making pressure contact with the contact body. The vibration type actuator according to any one of 3 above. The vibrating actuator according to any one of claims 1 to 4, wherein a distance from the vibrating body to the second fixing portion is shorter than a distance from the vibrating body to the first fixing portion. The vibration-type actuator according to claim 1, wherein the elastic body has at least one contact portion that makes pressure contact with the contact body . The elastic body has a substantially rectangular flat plate shape,
The vibrating actuator according to claim 1, wherein the vibrating body has two symmetry axes that are orthogonal to a thickness direction of the elastic body. The vibration-type actuator according to claim 7, wherein the conductive member is provided on the support member so as to be line-symmetric with respect to the two axes of symmetry. A plurality of reinforcing members fixed to each of the plurality of first fixing portions and the plurality of second fixing portions,
9. The vibration type actuator according to claim 1, wherein the support member is fixed at a predetermined position via the plurality of reinforcing members. The plurality of first fixing portions are fixed to predetermined positions on a surface substantially orthogonal to a direction in which the vibrating body receives a pressing force for making pressure contact with the contact body ,
10. The plurality of second fixing portions are fixed at a position farther from the contact body than a position at which the first fixing portion is fixed in the direction of receiving the pressing force. The vibration type actuator according to any one of 1. The vibration type actuator according to any one of claims 1 to 9, wherein the plurality of first fixing portions and the plurality of second fixing portions are integrally formed. The vibration type actuator according to claim 11, wherein the plurality of first support portions and the plurality of second support portions are integrally formed. A vibrating body having an electro-mechanical energy conversion element and an elastic body;
A support member for supporting the vibrating body,
A contact body in contact with the vibrating body,
The support member has a cross shape, and the vibrating body is joined to the crossing position of the cross shape of the support member, and power is supplied to the vibrating body via a conducting member provided in the support member. Vibration type actuator. A vibration-type actuator according to any one of claims 1 to 13 ,
A member positioned by driving the vibration type actuator.