JP2015228719A - Vibrator, vibration actuator and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance drive efficiency of a vibration actuator.SOLUTION: A vibration actuator 1 includes a vibrator 3 including a rectangular vibration part 11a to which a rectangular piezoelectric element 12 is bonded, and a driven body 4 coming into pressure contact with the vibrator 3 and moving relatively thereto. The vibrator 3 has two protrusions 11b1, 11b2 provided, at a predetermined interval, in the longitudinal direction of the vibration part 11 on the surface opposite to the surface, to which the piezoelectric element 12 is bonded, in the vibration part 11 in order to bring into pressure contact with the driven body 4, and an adjustment part 11d of a predetermined thickness formed integrally with the vibration part 11a with a predetermined thickness between the protrusions 11b1, 11b2 so as not to come into contact therewith. The vibrator 3 has a shape symmetrical in the longitudinal direction and widthwise direction of the vibration part 11a, respectively.

Description

  The present invention relates to a vibrator, a vibration type actuator, and an imaging device, for example, a vibrator that is driven by combining vibrations of different vibration modes, and a vibration type actuator that relatively moves the vibrator and a driven body. The present invention relates to an imaging device including a vibration type actuator.

  There has been proposed a vibration-type actuator that causes the vibrator and the driven body to move relative to each other by causing the vibrator to generate a combination of different vibration modes (see, for example, Patent Document 1). In the vibration type actuator described in Patent Document 1, two protrusions are provided on the vibrator, and a friction force is generated between the protrusion and the driven body by bringing the driven body and the protrusion into pressure contact. Is generated. Then, by causing the vibrator to vibrate in two different out-of-plane bending vibration modes to generate elliptical motion (or circular motion) at the tips of the two protrusions, Relative movement is possible.

  The two vibration modes excited by the vibrator in the prior art are also used in a vibration type actuator according to an embodiment of the present invention described later, and will be described in detail here.

  FIG. 8A is a perspective view showing a schematic structure of the vibrator 80. The vibrator 80 includes a rectangular diaphragm 81 and a piezoelectric element 82 joined to the diaphragm 81. Protrusions 81b1 and 81b2 are formed at two locations on the surface of the vibration plate 81 opposite to the surface to which the piezoelectric element 82 is bonded, and further, not shown at the respective tips of the protrusions 81b1 and 81b2. Contact portions 81e1 and 81e2 are formed in pressure contact with the driven body.

  FIG. 8B is a diagram schematically showing mode shapes of two bending vibration modes excited by the vibrator 80. By applying an alternating voltage (alternating voltage) to the piezoelectric element 82, vibration generated by synthesizing two out-of-plane bending vibration modes (hereinafter referred to as “mode A” and “mode B”) is excited in the vibrator 80. Let

  As shown in the upper diagram of FIG. 8B, mode A, which is the first vibration mode, is a first-order out-of-plane bending vibration in which two nodes appear parallel to the X direction in the figure, which is the longitudinal direction of the vibrator 80. This mode is a mode that is symmetrical to the YZ plane. In this specification, “parallel” is a concept that includes not only strictly parallel but also cases that can be regarded as parallel, and includes cases in which effects and properties due to being parallel are substantially obtained. Similarly, “vertical” is a concept that includes not only strictly vertical but also cases in which it can be regarded as vertical, and includes cases in which effects and properties due to vertical are substantially obtained.

  Due to the vibration of mode A, the contact portions 81e1 and 81e2 are excited with an amplitude that causes a major displacement in a direction (Z direction) perpendicular to the friction sliding surface of the driven body (not shown). That is, due to the vibration of mode A, the protrusions 81b1 and 81b2 are displaced in the direction of pushing up the driven body.

  As shown in the lower diagram of FIG. 8B, the mode B that is the second vibration mode is a second-order out-of-plane bending vibration mode in which three nodes appear parallel to the Y direction of the vibrator 80, and YZ The mode has a shape that is inversely symmetric to the plane and symmetrical to the ZX plane. Due to the vibration in mode B, the protrusions 81b1 and 81b2 are excited with an amplitude that causes a major displacement in a direction (X direction) parallel to the friction sliding surface of the driven body. That is, the contact portions 81e1 and 81e2 are displaced in the movement direction relative to the driven body by the vibration of mode B.

  By combining the vibration modes of modes A and B, the contact portions 81e1 and 81e2 perform an elliptical motion in the ZX plane, whereby a driving force (thrust) is generated between the driven body and the vibrator 80. The vibrator 80 and the driven body can be relatively moved in the X direction by this driving force.

  Next, the description of the vibration displacement of the two contact portions 81e1 and 81e2 in each vibration mode of modes A and B will be continued. In FIG. 8B, vibration displacements of the contact portions 81e1 and 81e2 in mode A are indicated by vectors V1-a and V2-a, respectively. Similarly, vibration displacements of the contact portions 81e1 and 81e2 in mode B are indicated by vectors V1-b and V2-b, respectively. Since the vibration in mode A is substantially symmetric with respect to the ZX plane, the vector V1-a and the vector V2-a are substantially symmetric with respect to the ZX plane. Further, since the vibration of mode B is substantially inversely symmetric about the ZX plane, the vector V1-b and the vector V2-b are substantially inversely symmetric about the ZX plane. Therefore, since the vibration displacement of the contact portions 81e1 and 81e2 has the same property, the movement of the contact portion 81e2 will be described below.

  In order to simplify the explanation, it is assumed that the mode A and the mode B are excited so that the vector V2-a and the vector V2-b are both unit quantities of 1. If the direction of the vector V2-a is indicated by an angle θ2-a with respect to the X direction, and the direction of the vector V2-b is indicated by an angle θ2-b with reference to the X direction, here, the angle θ2-a Is 82.6 degrees, and the angle θ2-b is 8.5 degrees.

  FIG. 9A is a diagram showing a displacement trajectory of one period of vibration of the contact portion 81e2 when Mode A and Mode B are excited with a difference of ¼ period in time. The horizontal axis is the displacement in the X direction, and the vertical axis is the displacement in the Z direction. When the mode B is excited so that the mode B is delayed by ¼ period with respect to the mode A, vibration displacement occurs in the direction indicated by the arrow in the figure. FIG. 9B is a diagram illustrating a displacement locus of one cycle of vibration of the contact portion 81e2 when the angle θ2-a is 90 degrees and the angle θ2-b is 0 degrees. The displacement locus shown in FIG. 9 (b) is substantially circular, whereas in FIG. 9 (a), it becomes an ellipse having an angle inclined in the X direction.

Japanese Patent No. 4261964

  Equipment equipped with the above-described vibration type actuators is required to reduce power consumption. Therefore, vibration actuators are also required to obtain a desired driving force while reducing power consumption, that is, to improve driving efficiency. It has been. Here, as described above, in the vibration type actuator, the driving force for the driven body is generated by the displacement locus of the contact portions 81e1 and 81e2. When FIG. 9A and FIG. 9B are compared, FIG. ), The driving force is reduced as compared with the displacement locus shown in FIG. This is because the timing at which the displacement in the Z direction becomes maximum and the timing at which the velocity in the X direction becomes maximum are shifted. Therefore, it is considered that the drive efficiency can be improved by bringing the vibration displacement generated in the vibrator 80 closer to an ideal state.

  An object of the present invention is to provide a vibrator having improved driving efficiency and a vibration type actuator including the vibrator.

  The vibrator according to the present invention is a vibrator including a vibration plate including a vibration portion, and an electro-mechanical energy conversion element bonded to one surface of the vibration portion of the vibration plate, , Two protrusions provided at a predetermined interval in a first direction on the surface of the diaphragm opposite to the surface to which the electro-mechanical energy conversion element is bonded, and contact with the two protrusions An adjusting portion integrally formed with the vibrating portion with a predetermined thickness between the two protrusions so as not to be parallel to the first direction and the opposite surface of the diaphragm. And it has the shape symmetrical to each direction of the said 1st direction and a perpendicular | vertical direction, It is characterized by the above-mentioned.

A vibration type actuator according to the present invention includes a vibration plate including a vibration portion, and a vibrator including an electromechanical energy conversion element bonded to one surface of the vibration portion of the vibration plate;
A vibration type actuator comprising a driven body that makes pressure contact with the vibrator and moves relative to the vibrator, wherein the vibrator is in contact with the driven body in order to make pressure contact The two protrusions provided at a predetermined interval in the driving direction on the surface opposite to the surface where the electro-mechanical energy conversion element is joined, and the two protrusions so as not to contact the two protrusions. An adjustment part integrally formed with the vibration part with a predetermined thickness between the protrusions, the driving direction and a direction parallel to the opposite surface of the diaphragm and perpendicular to the driving direction And having a symmetrical shape in each direction.

  ADVANTAGE OF THE INVENTION According to this invention, the drive efficiency of a vibration type actuator can be improved and, thereby, the power consumption of the apparatus carrying a vibration type actuator can be reduced.

It is a disassembled perspective view which shows schematic structure of the vibration type actuator which concerns on embodiment of this invention. It is a perspective view which shows the structure of the vibrator | oscillator unit used for the vibration type actuator of FIG. It is a perspective view which shows the structure of the vibrator | oscillator used for the vibrator | oscillator unit of FIG. It is a figure which shows the relationship between the thickness t of the adjustment part provided in the diaphragm which comprises the vibrator | oscillator of FIG. 3, and angle (theta) 2-a, (theta) 2-b (refer FIG.8 (b)). It is a perspective view which shows the structure of another vibrator | oscillator used for the vibrator | oscillator unit of FIG. It is a figure which shows the relationship between the thickness t of the adjustment part provided in the diaphragm which comprises the vibrator | oscillator of FIG. 5, and angle (theta) 2-a, (theta) 2-b (refer FIG.8 (b)). It is the top view and block diagram which show schematic structure of an imaging device provided with the vibration type actuator which concerns on embodiment of this invention. FIG. 6 is a perspective view showing a schematic structure of a vibrator according to a conventional technique, and a diagram schematically showing mode shapes of two bending vibration modes excited by the vibrator. FIG. 9 is a diagram illustrating an example of a displacement locus of a contact portion that is in pressure contact with a driven body when the vibrator of FIG. 8 is driven under a predetermined condition.

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

<First Embodiment>
FIG. 1 is an exploded perspective view showing a schematic configuration of a vibration type actuator 1 according to an embodiment of the present invention. For convenience of explanation, the three-dimensional orthogonal axes (X axis, Y axis, Z axis) shown in FIG. 1 are set for the vibration type actuator 1 and various directions are used as appropriate. I will do it.

  The vibration type actuator 1 is a device capable of linear driving with one degree of freedom, and includes a vibrator unit 2 and a driven body 4 that move relative to each other. The vibrator unit 2 is fixed to the slide part 35. The slide component 35 is held by two guide bars 34 arranged in parallel with the X direction in FIG. 1 so as to be slidable in the X direction. The two guide rods 34 are fixed in a state of being sandwiched between two second base members 32 fixed to the first base member 31.

  The vibrator unit 2 includes a vibrator 3 (see FIG. 3) and a support member 13 (see FIG. 2) which will be described later. The vibrator 3 is screwed to a fixing portion 35 b provided on the slide part 35 via the support member 13. As a result, the slide part 35 and the vibrator unit 2 can move together in the X direction.

  Between the slide component 35 and the vibrator unit 2, there is disposed a pressurizing spring 36 that is a pressurizing unit having a leaf spring shape and generating a spring force by being bent in the Z direction. The free end of the pressure spring 36 is in contact with the vibrator 3 constituting the vibrator unit 2 and presses the vibrator 3 toward the driven body 4.

  The driven body 4 is disposed on the upper side of the vibrator unit 2 in the Z direction. Specifically, both ends (X direction ends) of the driven body 4 having a square bar shape are fixed to the holding member 33, respectively. The two holding members 33 are screwed to the two second base members 32, respectively. Thus, in the present embodiment, the vibrator unit 2 is slid in the X direction, which is the driving direction, integrally with the slide component 35 with respect to the fixed driven body 4. The driven body 4 is made of, for example, a martensitic stainless material in order to ensure the wear resistance required for friction driving.

  The driven body 4 and the vibrator unit so that a frictional force necessary to generate a driving force (thrust) for sliding the vibrator unit 2 is generated between the driven body 4 and the vibrator unit 2. 2 is in a state of being pressed by the spring force of the pressure spring 36. Here, in order to realize a desired pressure contact state, the vibrator unit 2 and the driven body 4 need to be relatively displaceable in the Z direction. In the present embodiment, a part of the support member 13 is elastically deformed, so that the vibrator unit 2 and the driven body 4 can be relatively displaced in the Z direction.

  In the vibration type actuator 1, an arbitrary device can be driven by taking out a driving force (or displacement) using the slide part 35 that slides in the X direction integrally with the vibrator unit 2 as output means. As a specific example, the vibration type actuator 1 can be used for driving a lens of an imaging apparatus (camera) as described in the second embodiment.

  In this embodiment, the vibrator unit 2 is slid with respect to the driven body 4. However, the present invention is not limited to this, and the driven body 4 moves with respect to the fixed vibrator unit 2. It is good also as a structure. In such a case, the vibrator unit 2 may be fixed to a predetermined external member so that the vibrator unit 2 cannot slide and the driven body 4 may be held movably with respect to the vibrator unit 2. In this embodiment, the vibration type actuator 1 is a linear type in which the vibrator unit 2 slides in the X direction. However, the vibration type actuator 1 is not limited to this, and may be a rotary type. Good. Since the configuration of a rotary vibration actuator that has two contact portions 11e1 and 11e2 to be described later like the vibrator unit 2 and uses vibration generated in the contact portions 11e1 and 11e2, is well known. Omitted.

  Next, the vibrator unit 2 constituting the vibration type actuator 1 and the vibrator 3 constituting the vibrator unit 2 will be described in detail. FIG. 2 is a perspective view showing the structure of the vibrator unit 2 used in the vibration type actuator 1. FIG. 3 is a perspective view showing the structure of the vibrator 3 used in the vibrator unit 2.

  The vibrator unit 2 includes a vibrator 3 and a support member 13. The support member 13 elastically holds the vibrator 3 in the Z direction. The vibrator 3 is a substantially rectangular plate having a diaphragm 11 formed in a plate shape by an elastic body such as a metal material, and an electro-mechanical energy conversion element bonded to one surface of the diaphragm 11 by adhesion or the like. And a piezoelectric element 12 having the following shape. A flexible wiring board 14 is connected to the piezoelectric element 12 for electrical connection with the outside.

  The vibration plate 11 includes a substantially rectangular vibration part 11a and two protrusions 11b1 and 11b2 formed at predetermined intervals in the X direction on the upper surface of the vibration part 11a (the surface opposite to the bonding surface of the piezoelectric element 12). With. Contact portions 11e1 and 11e2 that are in pressure contact with the driven body 4 are provided on the upper end surfaces (upper surfaces protruding in the Z direction) of the protrusions 11b1 and 11b2. Joint portions 11c1 and 11c2 to be joined to the support member 13 are provided at both ends in the X direction of the diaphragm 11 (X direction side of the vibration portion 11a), and the joint portions 11c1 and 11c2 and the support member 13 are welded. Etc. are joined together.

  The diaphragm 11 has a symmetrical shape in each of the X direction and the Y direction. However, in the present embodiment, the “symmetrical shape” includes not only a strictly symmetrical shape but also a substantially symmetrical shape due to a processing error or the like. In addition, for example, the coupling holes 11c1 and 11c2 may be formed with positioning holes or the like used for joining the vibrator 3 with different shapes, but the vibration does not affect the vibration state of the vibrator 3. The difference in the shape of the plate 11 can be ignored. In this case, the diaphragm 11 is regarded as having a symmetrical shape.

  Further, the protrusions 11b1 and 11b2 and the contact portions 11e1 and 11e2 provided on the diaphragm 11 are respectively equivalent to the protrusions 81b1 and 81b2 and the contact portions 81e1 and 81e2 of the vibrator 80 described with reference to FIG. . Further, the vibration part 11a and the piezoelectric element 12 are equivalent to the vibration plate 81 and the piezoelectric element 82 of the vibrator 80, respectively. The vibrator 3 is driven by exciting vibration of the mode A (primary out-of-plane bending vibration mode) and mode B (secondary out-of-plane bending vibration mode) described with reference to FIG. Is done by doing. Since the details have already been described, the description is omitted here.

  An adjustment part 11d having a plate thickness thicker than that of the peripheral part is integrally formed with the vibration part 11a at the center of the upper surface in the Z direction (surface facing the driven body 4) of the vibration part 11a. Note that “being integrally formed” means that the vibrating portion 11a and the adjusting portion 11d are made of the same material, have no boundary, and have a continuous structure.

  As shown in FIGS. 2 and 3, the adjusting portion 11 d is generally a protrusion in the vicinity of the approximate center in the X direction and the Y direction so that its long side is parallel to the X direction, which is the longitudinal direction of the diaphragm 11. It is provided in a region between the portions 11b1 and 11b2. In the present embodiment, the adjusting unit 11d has a uniform thickness and, like the other components of the diaphragm 11, each direction of the driving direction (X direction) and the direction perpendicular to the driving direction (Y direction). Are formed in a symmetrical shape. In addition, if the adjustment part 11d contacts the projection parts 11b1 and 11b2, there is a possibility that the adjustment part 11d may have an unnecessary influence on the displacement direction and the displacement amount when the contact parts 11e1 and 11e2 vibrate. The adjustment part 11d is formed so as not to contact the protrusions 11b1 and 11b2 so that such a problem does not occur.

  The operation of the adjusting unit 11d will be described. FIG. 4A is a diagram illustrating the relationship between the thickness t of the adjustment unit 11d and the angles θ2-a and θ2-b. The thickness t of the adjusting portion 11d is a value based on the surface of the portion of the vibrating portion 11a where the adjusting portion 11d is not formed (from the Z-direction upper surface of the peripheral portion of the vibrating portion 11a to the Z direction of the adjusting portion 11d). Thickness to the top surface). In addition, the angles θ2-a and θ2-b are as already described with reference to FIG.

  In FIG. 4A, the horizontal axis represents the thickness t of the adjusting portion 11d, and the vertical axis represents the values of the angles θ2-a and θ2-b. Both the angles θ2-a and θ2-b vary depending on the value of the thickness t. When the thickness t is approximately 0.25 mm to 0.3 mm, the angle θ2-a is approximately 90 degrees. It can be seen that the angle θ2-b is approximately 0 degrees. That is, by providing the diaphragm 11 with the adjusting portion 11d having a predetermined thickness, the angles θ1-a and θ2-a are set to approximately 90 degrees (the vectors V1-a and V2-a are parallel to the Z direction) and the angle θ1-b and θ2-b can be set to approximately 0 degrees (vectors V1-b and V2-b are parallel to the X direction). In this way, both the contact portions 11e1 and 11e2 can perform a motion that draws a substantially circular displacement locus as shown in FIG. 9B, so that the vibration type actuator 1 has a higher efficiency than the conventional one. It becomes possible to drive with.

  The drive efficiency of the vibration type actuator 1 can be increased not only by adjusting the thickness t of the adjusting unit 11d but also by adjusting the shape of the adjusting unit 11d (the dimensions of the adjusting unit 11d in the X and Y directions). FIG. 4B is a diagram illustrating the relationship between the dimensional ratio of the adjusting unit 11d in the X direction and the Y direction and the angles θ2-a and θ2-b. The dimensional ratio of the horizontal axis includes the dimension in the Y direction. The value divided by the dimension in the X direction is used. When this dimensional ratio is approximately 0.876 to 0.877, the angles θ1-a and θ2-a are set to approximately 90 degrees, and the angles θ1-b and θ2-b are set to approximately 0 degrees. It can be seen that the contact portions 11e1 and 11e2 can be driven with a substantially circular displacement locus as shown in FIG.

  Here, it has been described that the driving efficiency of the vibration type actuator 1 can be increased by adjusting the thickness t of the adjusting portion 11d or adjusting the dimensional ratio between the X direction and the Y direction. However, the present invention is not limited to this, and the same effect can be obtained by adjusting the shape of the adjusting portion 11d and the position where the adjusting portion 11d is provided. For example, although the thickness t of the adjusting portion 11d is assumed to be uniform, the thickness is not limited to this, and the thickness may be different depending on the position as long as the driving efficiency is improved.

  By the way, in this embodiment, in the diaphragm 11, the adjustment part 11d is integrally formed with the vibration part 11a. This is due to the following reason. That is, when the adjustment part 11d is prepared as a separate body from the vibration part 11a (diaphragm 11) and is configured to be coupled to the vibration part 11a by adhesion, welding, or the like, due to variations in rigidity at the coupling part, There is a possibility that the symmetry of the vibration state of the vibration part 11a is broken. And if the symmetry of the vibration state of the vibration part 11 breaks, the vibration displacement of the contact parts 11e1 and 11e2 (projection parts 11b1 and 11b2) does not become a desired value. In order to avoid the occurrence of such a problem, the adjustment portion 11d needs to be integrally formed with the vibration portion 11a in the vibration plate 11.

  As described above, in the vibration type actuator 1, since the driving efficiency can be increased as compared with the conventional case, the power consumption can be reduced. On the contrary, it is possible to obtain a larger driving force with the same power consumption as in the prior art. As a result, the vibration actuator 1 can be reduced in size and the apparatus on which the vibration actuator 1 is mounted can be reduced in size. Can be realized.

Second Embodiment
FIG. 5 is a perspective view showing a schematic structure of a vibrator 3A used in the vibration type actuator according to the second embodiment. In the vibrator 3A, the shape of the adjustment part 11dA integrally formed with the vibration part 11a of the diaphragm 11A is different from the shape of the adjustment part 11d of the vibrator 3 described in the first embodiment, and other components and The constituent parts are the same as the constituent parts and constituent parts of the vibrator 3 (see FIG. 3). Therefore, in the vibrator 3A, the same components and parts as those of the vibrator 3 are denoted by the same reference numerals and description thereof is omitted.

  In the vibrator 3A, the vibration direction of the contact portions 11e1 and 11e2 in the mode B is adjusted to a desired value by adjusting the interval between the protruding portions 11b1 and 11b2. The adjustment portion 11d integrally formed with the vibration plate 11A has a substantially rectangular shape provided so that its long side is parallel to the Y direction, which is the short direction of the vibration plate 11A, and a protrusion in the X direction. It is provided at a center position between 11b1 and 11b2. In the vibrator 3A, the angles θ1-b and θ2-b do not need to be adjusted by the adjusting unit 11dA, and the angles θ1-a and θ2-a may be set to desired values.

  FIG. 6 is a diagram illustrating the relationship between the thickness t of the adjustment unit 11dA and θ2-a and θ2-b. Also here, the thickness t of the adjusting portion 11dA is a value based on the surface of the portion of the vibrating portion 11a where the adjusting portion 11d is not formed. As shown in FIG. 6, the angle θ2-b has a substantially constant value in the vicinity of 0 degrees regardless of the thickness t of the adjusting unit 11dA. However, the angle θ2-a has the adjusting unit 11dA. The thickness t increases as the thickness t increases. And when thickness t of adjustment part 11dA is about 0.35 mm in general, it turns out that angle theta 2-a becomes about 90 degrees. Therefore, also in the vibrator 3A, by appropriately setting the thickness t of the adjusting unit 11dA, the angles θ1-a and θ2-a are set to approximately 90 degrees, and the angles θ1-b and θ2-b are set to approximately 0 degrees. The contact portions 11e1 and 11e2 can be moved along a substantially circular displacement locus shown in FIG.

  As described above, even when the vibrator 3A is applied to the vibration type actuator 1 instead of the vibrator 3, the driving efficiency of the vibrator 3A can be increased as compared with the conventional case, so that power consumption can be reduced. It becomes possible. Here, an example in which the angles θ1-a and θ2-a are set to desired angles by adjusting the thickness t of the adjusting unit 11dA has been shown, but the planar shape and dimensions of the adjusting unit 11dA are adjusted. Also, the angles θ1-a and θ2-a can be set to desired angles. Here, the adjustment unit 11dA has a uniform thickness t. However, the thickness is not limited to this, and the thickness may be different depending on the position as long as the driving efficiency is improved.

<Third Embodiment>
Here, an example in which the above-described vibration type actuator according to the embodiment of the present invention is applied to an imaging apparatus will be described. FIG. 7A is a top view illustrating a schematic configuration of the imaging apparatus 700. FIG. The imaging apparatus 700 includes a camera body 730 on which an imaging element 710 and a power button 720 are mounted. The imaging device 700 includes a first lens group (not shown), a second lens group 320, a third lens group (not shown), a fourth lens group 340, a vibration type actuator 620 disposed on the base, A lens barrel 740 including 640 is provided. The lens barrel 740 can be replaced as an interchangeable lens, and a lens barrel 740 suitable for a subject to be photographed can be attached to the camera body 730. In the imaging apparatus 700, the second lens group 320 and the fourth lens group 340 are driven by the two vibration actuators 620 and 640, respectively, and the vibration actuator 1 of the first embodiment is used as the vibration actuators 620 and 640. Used.

  FIG. 7B is a block diagram illustrating a schematic structure of the imaging apparatus 700. The first lens group 310, the second lens group 320, the third lens group 330, the fourth lens group 340, and the light amount adjustment unit 350 are disposed at predetermined positions on the optical axis inside the lens barrel 740. The light that has passed through the first lens group 310 to the fourth lens group 340 and the light amount adjustment unit 350 forms an image on the image sensor 710. The output of the image sensor 710 is sent to the camera processing circuit 750.

  The camera processing circuit 750 performs amplification, gamma correction, and the like on the output signal from the image sensor 710. The camera processing circuit 750 is connected to the CPU 790 through the AE gate 755 and is connected to the CPU 790 through the AF gate 760 and the AF signal processing circuit 765. The video signal that has undergone 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 imaging 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 actuators 620 and 640 and the meter 630 so that the determined exposure and an appropriate focus state are obtained, so that the second lens group 320, the fourth lens group 340, and the light amount adjustment unit 350 are controlled. Adjust the position in the optical axis direction. Under the control of the CPU 790, the vibration type actuator 620 moves the second lens group 320 in the optical axis direction, the vibration type actuator 640 moves the fourth lens group 340 in the optical axis direction, and the light quantity adjustment unit 350 is controlled by the meter 630. Drive controlled.

  The position of the second lens group 320 driven by the vibration type actuator 620 in the optical axis direction is detected by the first linear encoder 770, and the detection result is notified to the CPU 790 and fed back to the drive of the vibration type actuator 620. Similarly, the position in the optical axis direction of the fourth lens group 340 driven by the vibration type actuator 640 is detected by the second linear encoder 775, and the detection result is notified to the CPU 790, which is fed back to the drive of the vibration type actuator 640. Is done. The position in the optical axis direction of the light amount adjustment unit 350 is detected by the diaphragm encoder 780, and the detection result is notified to the CPU 790, which is fed back to the drive of the meter 630.

  As described above, the vibration type actuator 1 according to the first embodiment can be used as an application for moving a predetermined lens group of the imaging apparatus 700 in the optical axis direction, thereby enabling reliable lens driving. A highly-capable imaging device 700 can be realized. Of course, the vibration type actuator 1 may include the vibrator 3A described in the second embodiment.

<Other embodiments>
Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. Furthermore, each embodiment mentioned above shows only one embodiment of this invention, and it is also possible to combine each embodiment suitably.

DESCRIPTION OF SYMBOLS 1 Vibration type actuator 2 Vibrator unit 3, 3A Vibrator 4 Driven body 11 Diaphragm 11b1, 11b2 Protrusion part 11e1, 11e2 Contact part 11d, 11dA Adjustment part 12 Piezoelectric element (electro-mechanical energy conversion element)
700 Imaging device

Claims (14)

A vibrator including a vibration portion, and a vibrator including an electro-mechanical energy conversion element bonded to one surface of the vibration portion in the vibration plate,
The vibrator is
Two protrusions provided at a predetermined interval in a first direction on a surface of the diaphragm opposite to a surface to which the electro-mechanical energy conversion element is bonded;
An adjustment part integrally formed with the vibration part with a predetermined thickness between the two protrusions so as not to contact the two protrusions;
A vibrator having a symmetric shape in each of the first direction and a direction parallel to the opposite surface of the diaphragm and perpendicular to the first direction.   The vibrator according to claim 1, wherein the adjustment portion has a uniform thickness.   The vibrator according to claim 1, wherein the adjustment unit has a shape that is long in a longitudinal direction of the vibration unit and short in a short direction of the vibration unit.   4. The vibrator according to claim 3, wherein a value obtained by dividing a length in a short direction of the adjustment unit by a length in a longitudinal direction is in a range of 0.876 to 0.877. 5.   The adjusting portion has a substantially rectangular shape that is short in the longitudinal direction of the vibrating portion and long in the short direction of the vibrating portion, and is provided in the center between the two protruding portions. The vibrator according to claim 1 or 2.   The vibrator according to claim 1, wherein two different out-of-plane bending vibrations are excited. A vibration plate including a vibration portion, and a vibrator including an electro-mechanical energy conversion element bonded to one surface of the vibration portion of the vibration plate;
A vibration type actuator comprising a driven body that is in pressure contact with the vibrator and performs relative movement with the vibrator;
The vibrator is
Two protrusions provided at predetermined intervals in the driving direction on the surface of the diaphragm opposite to the surface to which the electro-mechanical energy conversion element is bonded in order to make pressure contact with the driven body When,
An adjustment part integrally formed with the vibration part with a predetermined thickness between the two protrusions so as not to contact the two protrusions;
A vibration type actuator having a shape symmetrical with respect to each of a drive direction and a direction parallel to the opposite surface of the diaphragm and perpendicular to the drive direction.   The vibration type actuator according to claim 7, wherein a thickness of the adjustment unit is uniform.   9. The vibration type actuator according to claim 7, wherein the adjustment unit has a shape that is long in a longitudinal direction of the vibration unit and short in a short direction of the vibration unit.   10. The vibration type actuator according to claim 9, wherein a value obtained by dividing a length in a short direction of the adjustment portion by a length in a longitudinal direction is in a range of 0.876 to 0.877.   The adjusting portion has a substantially rectangular shape that is short in the longitudinal direction of the vibrating portion and long in the short direction of the vibrating portion, and is provided in the center between the two protruding portions. The vibration type actuator according to claim 7 or 8.   The vibration type actuator according to claim 7, wherein the vibrator is excited by two different out-of-plane bending vibrations. A diaphragm including a substantially rectangular vibrating portion; and a vibrator including a substantially rectangular electro-mechanical energy conversion element joined to one surface of the vibrating portion of the diaphragm;
A vibration type actuator comprising a driven body that is in pressure contact with the vibrator and performs relative movement with the vibrator;
The vibrator is
Two protrusions provided at a predetermined interval in the longitudinal direction of the vibrating portion on the surface of the diaphragm opposite to the surface to which the electro-mechanical energy conversion element is bonded in order to make pressure contact with the driven body And
An adjustment part integrally formed with the vibration part between the two protrusions so as not to contact the two protrusions;
The adjustment unit has a direction in which the vibrator and the driven body perform relative movement when vibrations of a primary out-of-plane bending vibration mode and a secondary out-of-plane bending vibration mode are excited in the vibrator. The angle formed between the direction of the relative movement and the vibration direction of the secondary out-of-plane bending vibration mode when the angle formed with the vibration direction of the primary out-of-plane bending vibration mode is approximately 90 degrees. Is provided so as to be approximately 0 degrees. The vibration type actuator according to any one of claims 7 to 13,
A lens moved by the vibration actuator;
An image pickup apparatus comprising: an image pickup element that forms an image of light passing through the lens.

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