JP2009219324A - Vibration actuator, lens unit and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration actuator can improve the output with high efficiency and enhance the flexibility in the design of a unit to be driven. <P>SOLUTION: The vibration actuator 100 is provided with a rotor 140, rotating about a rotary shaft; a cylindrical vibration-rotating member 120, disposed coaxially with the rotor 140 and allowing the rotor 140 to be slidably inserted around the rotating shaft; and a drive section 130 for vibration-moving the vibration-rotating member 120. An annular and endless convex portion 152 and concave portion 154, which are slidably mated to each other around the rotary shaft of the rotor are respectively provided on the outer circumferential portion 143 of the rotor 140 and the inner circumferential portion 121 of the vibration-rotating member 120. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration actuator, a lens unit including the vibration actuator, and an imaging apparatus. The present invention particularly relates to a vibration actuator that rotates a rotor by a swing member, a lens unit including the vibration actuator, and an imaging apparatus.

  An ultrasonic motor as a vibration actuator comprising a stator as a swinging member which is a cylindrical body around which a plurality of electromechanical conversion elements as drive units are arranged, and a rotor as a rotating shaft inserted through the stator Is known (see, for example, Patent Document 1). In this vibration actuator, the rotor is rotated by a swinging motion generated in the stator by the electromechanical transducer.

As another ultrasonic motor, a rotor having a plurality of orbiting ridges, a bearing member having a plurality of orbiting grooves for accommodating the orbiting ridges of the rotor, and a stator that vibrates one end in the axial direction of the rotor (For example, refer to Patent Document 2).
Special table 2007-505599 gazette JP 2005-354775 A

  Here, in the vibration actuator described in Patent Document 1, a screw thread is formed on the outer peripheral portion of the rotor, and a screw groove that is screwed with the screw thread is formed on the inner peripheral portion of the stator. , Vibration is transmitted from the stator to the rotor, and the screw thread slides with respect to the screw groove. Here, in the vibration actuator, since the rotor and the stator are screwed together, the sliding area between the rotor and the stator can be increased efficiently, and the output of the vibration actuator can be increased efficiently. . On the other hand, since the rotor rotates and moves in the axial direction, the use of the vibration actuator is limited to a case where the movement of the rotor in the axial direction can be permitted, such as when the rotor is used as a ball screw.

  Further, in the ultrasonic motor described in Patent Document 2, the abutting portion where the rotor and the bearing member are abutted by pressure, and the rotor and the stator abut for transmission of driving force. Since the contact portion is separate, the transmission efficiency of the driving force is low. Further, since the stator is provided at one end in the axial direction of the rotor, the length in the axial direction becomes long, and it is difficult to downsize the entire apparatus.

  In order to solve the above problems, a vibration actuator includes a rotor that rotates around a rotation axis, and a cylindrical swing-out member that is arranged coaxially with the rotor and that is slidably inserted around the rotation axis. A drive unit that swings the swing member, and includes either an annular convex part or a concave part that fits slidably around the rotation axis of the rotor on the outer peripheral part of the rotor, The other of the swirling member has an inner peripheral portion, and the other of the convex portion and the concave portion of the swirling member swings to slide on the one of the convex portion and the concave portion of the rotor to rotate the rotor. To drive.

  The lens unit includes an optical member, a lens barrel that houses the optical member, and a vibration actuator that is provided inside the lens barrel and moves the optical member, The vibration actuator includes a rotor that rotates about a rotation axis, a cylindrical swing member that is arranged coaxially with the rotor and that is slidably inserted around the rotation shaft, and a swing member that swings the swing member. A drive unit that rotates around the rotor, and any one of an annular convex part and a concave part that slidably fit around the rotation axis of the rotor is provided on the outer peripheral part of the rotor, and the other is provided on the swing member. It has an inner peripheral part, and the other of the convex part and the concave part of the whirling member is swung around to slide on the one of the convex part and the concave part of the rotor to rotationally drive the rotor.

  The imaging apparatus includes an optical member, a lens barrel that houses the optical member, a vibration actuator that moves the optical member, an imaging unit that captures an image formed by the optical member, and the vibration actuator. And a control unit that controls the imaging unit, wherein the vibration actuator includes a rotor that rotates about a rotation axis, and is arranged coaxially with the rotor so that the rotor slides about the rotation axis Any of an annular convex part and a concave part that are slidably fitted around the rotation axis of the rotor One of them is provided on the outer peripheral part of the rotor, and the other is provided on the inner peripheral part of the whirling member. And slides on the one recess for rotationally driving the rotor.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

  First, a vibration actuator 100 according to an embodiment of the present invention will be described. FIG. 1 is an exploded perspective view of a vibration actuator 100 according to the present embodiment. FIG. 2 is a perspective view of the vibration actuator 100. Further, FIG. 3 shows a cross-sectional view of the vibration actuator 100 as viewed from a direction orthogonal to the axial direction of the rotor 140 (hereinafter referred to as a radial direction).

  For convenience of explanation, the drive output side in the axial direction of the rotor 140 is referred to as an output side, and the opposite side is referred to as a non-output side. Further, a cross section viewed from the radial direction of the rotor 140 is referred to as a vertical cross section, and a cross section viewed from the axial direction of the rotor 140 is referred to as a flat cross section.

  As shown in FIGS. 1 to 3, the vibration actuator 100 includes a rotor 140, a swing member 120, and a drive unit 130. The rotor 140 rotates around the rotation axis and outputs power.

  The swing member 120 has a cylindrical shape having an inner peripheral portion 121 having a circular cross section. In the swing member 120, the rotor 140 is slidably inserted around the rotation axis. Further, the swing member 120 is disposed coaxially with the rotor 140. Both end portions in the axial direction of the swing member 120 are fixedly held by the holding portion 180. The drive unit 130 causes the swing member 120 to perform a bending motion, that is, a swing motion, so that the axis rotates around the rotation axis of the rotor 140.

  The swing member 120 is formed by combining a plurality of (for example, three as shown) divided pieces 125 divided in the circumferential direction. The plurality of divided pieces 125 are bound by an annular member 156 as a binding member.

  A minute clearance is secured between both axial ends of the outer peripheral portion 143 of the rotor 140 and both axial ends of the inner peripheral portion 121 of the swing member 120. A plurality of annular and endless convex portions 152 extending around the rotation axis are continuously formed along the axial direction at the axially central portion of the outer peripheral portion 143 of the rotor 140. On the other hand, a plurality of annular and endless concave portions 154 extending around the rotation axis are continuously formed along the axial direction at the central portion in the axial direction of the inner peripheral portion 121 of the swing member 120. 152 and the recess 154 are fitted. As a result, the rotor 140 cannot be inserted into or removed from the swing member 120.

  Here, the “fit” between the convex portion 152 and the concave portion 154 includes a fit in a state where there is play in the axial direction and the radial direction of the rotor 140, so-called “free fit”. The convex portion 152 may be provided on the inner peripheral portion 121 of the swinging member 120, and the concave portion 154 may be provided on the outer peripheral portion 143 of the rotor 140.

  Hereinafter, the configuration of the vibration actuator 100 according to the present embodiment will be described in detail. As shown in FIG. 1 to FIG. 3, the swing member 120 is formed of a variety of elastically deformable metal materials, resin materials, ceramic materials, and the like into a cylindrical shape whose longitudinal direction is the axial direction of the rotor 140. Yes. Note that the outer shape of the swing-out member 120 may be other shapes such as a rectangular column shape.

  The rotor 140 is formed in a columnar shape, and a gear coupling portion 146 having a rectangular plane cross-sectional shape is formed at the output side end portion of the rotor 140. The gear coupling portion 146 protrudes from the swing member 120 to the output side.

  An output gear 170 is disposed on the output side end of the rotor 140. A rectangular shaft hole 172 that can be fitted to the gear coupling portion 146 is formed in the shaft center of the output gear 170. The output gear 170 rotates integrally with the rotor 140 in a state where the gear coupling portion 146 and the shaft hole 172 are fitted.

  A drive unit 130 is disposed on the outer periphery 123 of the swing member 120. The drive unit 130 includes a plurality (three in the present embodiment) of electromechanical conversion elements 132, 134, and 136 arranged along the circumferential direction of the swing member 120. The electromechanical conversion elements 132, 134, and 136 are rectangular plate-like bodies whose longitudinal direction is the axial direction of the swing member 120, and are attached to the outer peripheral portion 123 of the divided piece 125 by adhesion or the like. The electromechanical conversion elements 132, 134, 136 are provided with electrodes (not shown). The electromechanical conversion elements 132, 134, and 136 are applied with a driving voltage from the power supply unit (not shown) through the electrodes.

  In addition, the electromechanical conversion elements 132, 134, and 136 include a piezoelectric material that expands when a driving voltage is applied. Specifically, it includes piezoelectric materials such as lead zirconate titanate titanate, crystal, lithium niobate, barium titanate, lead titanate, lead metaniobate, polyvinylidene fluoride, lead zinc niobate, lead scandium niobate, etc. It is out.

  Since many piezoelectric materials are fragile, they are preferably reinforced with a highly elastic metal material such as phosphor bronze. Alternatively, the electromechanical conversion elements 132, 134, and 136 may be formed by forming a piezoelectric material layer on the outer peripheral portion 123 of the divided piece 125 using the divided piece 125 itself as a carrier. The electrode is formed directly on the surface of the piezoelectric material by an electrode material such as nickel or gold by a method such as plating, sputtering, vapor deposition, or thick film printing.

  The electromechanical conversion elements 132, 134, and 136 are arranged so as to be accommodated in the outer peripheral portion 123 of each divided piece 125. That is, the electromechanical conversion elements 132, 134, 136 are arranged offset (shifted) from the dividing line 127 described later in the circumferential direction of the swing member 120.

  Each convex part 152 is formed so that the longitudinal section thereof is V-shaped. As a result, a so-called sawtooth shape in which V-shaped irregularities are repeated by a plurality of convex portions 152 continuous in the axial direction of the rotor 140 is formed in the central portion in the axial direction of the outer peripheral portion 143 of the rotor 140.

  Each concave portion 154 is formed in a V-shaped cross section similar to the convex portion 152. As a result, a so-called sawtooth shape in which V-shaped unevenness is repeated by a plurality of concave portions 154 continuous in the axial direction of the rotor 140 is formed at the central portion in the axial direction of the inner peripheral portion 121 of the swing member 120. Yes. In the present embodiment, the convex portion 152 and the concave portion 154 have a sawtooth shape, but may have other convex and concave shapes such as a wave shape.

  As described above, the convex portion 152 and the concave portion 154 are fitted in a loosely fitted state. Further, the convex portion 152 includes a pair of inclined surfaces 151 and 153 that are close to each other toward the outer side in the radial direction of the rotor 140. On the other hand, the recess 154 includes a pair of inclined surfaces 155 and 157 that are close to each other toward the radially outward direction of the swing-around member 120. The inclined surfaces 151 and 155 are arranged on the output side, and the inclined surfaces 153 and 157 are arranged on the non-output side. When the rotor 140 is urged to the output side, the inclined surface 151 and the inclined surface 155 abut, while when the rotor 140 is urged to the non-output side, the inclined surface 153 and the inclined surface 157 Abut.

  A bearing plate 160 is disposed on the non-output side of the rotor 140. The bearing plate 160 rotatably supports the non-output side end portion of the rotor 140. Further, a tension coil spring 162 as an urging member is disposed between the bearing plate 160 and the non-output side end of the swing member 120.

  One end of the tension coil spring 162 in the axial direction is attached to a surface of the bearing plate 160 facing the swing member 120. The other axial end of the tension coil spring 162 is attached to the non-output side end face of the swing member 120. Further, the tension coil spring 162 is elastically stretched. As a result, the bearing plate 160 is urged toward the swing member 120 by the tension coil spring 162, so that the inclined surface 151 of the convex portion 152 is pressed against the inclined surface 155 of the concave portion 154.

  For this reason, when the rotor 140 rotates, the inclined surface 151 slides relative to the inclined surface 155. That is, the sliding portion 159 is formed by the inclined surface 151 and the inclined surface 155. In this embodiment, the rotor 140 is biased toward the swing member 120 by the elastic extension force of the tension coil spring 162. However, even if the rotor 140 is biased toward the swing member 120 by the elastic contraction force of the compression coil spring. Good. In addition, it is not essential to provide a biasing member that biases the rotor 140 toward the swinging member 120 side. For example, the output gear 170 is a helical gear, and the rotor 140 is driven by the thrust force generated by the output gear 170. The swaying member 120 may be biased.

  4 is a cross-sectional view taken along the line 4-4 of FIG. As shown in FIGS. 3 and 4, the outer shape of the annular member 156 is formed in a rectangular shape in plan view. The annular member 156 is formed with a circular hole 158 coaxial with the swing member 120. The diameter of the circular hole 158 is slightly smaller than the diameter at both axial ends of the outer peripheral portion 123 of the swing member 120, and both axial ends of the outer peripheral portion 123 of the swing member 120 are formed in the circular holes 158. Press fit. In other words, the annular member 156 is fitted to both end portions in the axial direction of the swing member 120 in a fixed state. A plurality of split pieces 125 are bundled at both axial ends of the swirl member 120 by a pair of upper and lower annular members 156. The plurality of divided pieces 125 are divided in the circumferential direction with a dividing line 127 extending along the axial direction of the rotor 140 as a boundary. In this embodiment, the swing member 120 is divided into three equal parts in the circumferential direction of the rotor 140 with the three dividing lines 127 as a boundary. Each of the divided pieces 125 has a flat cross-sectional shape that is an arc shape and a rectangular plate material in a side view.

  In the present embodiment, the plurality of divided pieces 125 are bundled by the annular member 156. However, the plurality of divided pieces 125 may be bonded together. In addition, a plurality of divided pieces can be coupled also by locking each divided piece 125 to a coupling member disposed inside the swing member 120.

  Further, the holding portion 180 is attached to the annular member 156 as described above. The holding part 180 is a disk-shaped member arranged coaxially with the rotor 140. The holding portion 180 is formed with a rectangular opening 186 through which the swing member 120 is inserted, and a mounting hole 184 through which a screw or the like is inserted.

  Here, the angle between the diagonals of the annular member 156 is set slightly longer than each side of the opening 186, and the annular member 156 is in a state where the corner of the annular member 156 is in contact with the center of the edge of the opening 186. And the opening 186 are fitted. In addition, a notch 102 (see FIGS. 1 to 3) into which the central portion of the edge of the opening 186 can be fitted is formed at the central portion in the axial direction of the corner portion of the annular member 156. For this reason, the annular member 156 is rotated around the axis after being inserted into the opening 186, and the four notches 102 are fitted into the center of the edge of the four openings 186, so that the annular member 156 is rotated around the axis. It is possible to integrate with the holding part 180 in a state where it is positioned. The holding unit 180 is attached to a driven device that uses the vibration actuator 100 as a driving source by a screw or the like inserted through the attachment hole 184.

  Next, the operation in this embodiment will be described. 5A and 5B are conceptual diagrams illustrating the swinging motion of the swinging member 120 in the driving state of the vibration actuator 100. FIG. In the drive state of the vibration actuator 100, an alternating voltage having a phase delayed by 2π / 3 is sequentially applied to the electromechanical conversion elements 132, 134, and 136.

  Here, when a positive drive voltage is applied to one of the electromechanical conversion elements 132, 134, and 136, a negative drive voltage is applied to the remaining two electromechanical conversion elements. As a result, an operation occurs in which the one electromechanical conversion element expands and the remaining two electromechanical conversion elements contract. Then, the electromechanical conversion element to which the positive drive voltage is applied shifts in one direction along the circumferential direction of the swing member 120, and in accordance with the two, two negative drive voltages are applied. The electromechanical conversion element is also shifted in the same direction as the shift direction of application of the positive drive voltage, whereby the above operation is shifted in the circumferential direction of the swing member 120.

  Further, both end portions in the axial direction of the swing member 120 are fixedly held by the holding portion 180 as described above. For this reason, as shown in FIG. 5B, the central portion in the axial direction of the swing member 120 moves circularly around the rotor 140. That is, a swinging motion is generated in the entire swinging member 120 with the central portion in the axial direction as the antinode X and both ends in the axial direction as nodes Y. Then, the swinging movement of the swinging member 120 causes the inclined surface 155 to slide with respect to the inclined surface 151 in the sliding portion 159, so that the swinging motion is transmitted to the rotor 140, thereby causing the rotor 140 to move. It is rotated and power is output via the output gear 170.

  Here, in the present embodiment, by providing the sliding portion 159 that makes one round around the rotation axis of the rotor 140, compared with the case where the rotor 140 and the swinging member 120 slide in a part of the circumferential direction. Thus, the sliding area between the rotor 140 and the swing member 120 can be increased efficiently. Therefore, even if the vibration actuator 100 is small, the sliding area between the rotor 140 and the swinging member 120 can be made larger than that of an equivalent size. Therefore, a high torque can be generated as compared with a vibration actuator of the same size. Also, the sliding portion 159 is in contact with the tension of the tension coil spring 162, and the driving force is transmitted by the same sliding portion 159. The rotor 140 can be driven to rotate efficiently as compared with the case where the portion in contact with the rotor is separate. Furthermore, since the swing member 120 surrounding the rotor 140 is driven from the outer periphery of the swing member 120 by the electromechanical conversion element 134, the electromechanical conversion element 134 is disposed at one end of the rotor 140 in the axial direction. In comparison, the entire apparatus can be reduced in size.

  In addition, the inclined surface 151 and the inclined surface 155 forming the sliding portion 159 are provided in the convex portion 152 and the concave portion 154, respectively. The convex portions 152 and the concave portions 154 are not spiral, but are formed in an annular and endless shape. The plurality of convex portions 152 and the concave portions 154 arranged in the axial direction of the rotor 140 are not thread-shaped but saw-toothed. A fitting portion having a shape is formed.

  For this reason, the rotor 140 rotates at a certain axial position when the swing member 120 is swinging. Therefore, since the position of the output gear 170 in the axial direction is constant, the output gear 170 can also be used for a driven part that cannot allow the output gear 170 to move in the axial direction. Therefore, it is possible to provide a vibration actuator that can generate high torque despite its small size and is not limited in its application.

  Further, by providing a plurality of convex portions 152 and concave portions 154 in the axial direction of the rotor 140, the sliding area between the rotor 140 and the swing-out member 120 can be further increased. Therefore, the generated torque can be further increased.

  Further, by making the sliding portion 159 an inclined surface inclined in the axial direction of the rotor 140 toward the outer diameter side of the rotor 140, vibration and load are applied in the axial direction and the radial direction from the swing member 120 to the rotor 140. Can communicate. Therefore, the generated torque can be increased efficiently.

  Further, the sliding portion 159 is an inclined surface inclined from the opening side to the bottom side of the concave portion 154 toward the inclined surface 157 as a hole wall facing the sliding portion 159 and the rotor 140 in the axial direction. That is, the concave portion 154 is a V-groove whose width increases from the bottom side to the opening side, and the convex portion 152 is a V-shaped protrusion whose width decreases from the bottom side to the top side. For this reason, since the convex part 152 and the recessed part 154 can be continuously formed in the axial direction of the rotor 140, the sliding part 159 can be arrange | positioned densely. Therefore, the sliding area between the rotor 140 and the swing member 120 can be increased more efficiently, and thus the generated torque can be further increased.

  Further, by arranging the convex portion 152 and the concave portion 154 at the position of the antinode X of the vibration generated in the swing member 120, vibration can be efficiently transmitted from the swing member 120 to the rotor 140. Therefore, the output from the rotor 140 can be increased more efficiently.

  In the present embodiment, the convex portion 152 and the concave portion 154 are arranged at the position of the antinode X of the vibration generated by the swinging member 120, that is, the central portion in the axial direction of the rotor 140 and the swinging member 120. As shown in FIG. 6, the entire circumference in the axial direction of the inner peripheral portion 121 of the swing member 120 may be provided. In this case, the sliding area between the rotor 140 and the swing member 120 can be further increased, and the generated torque can be further increased. On the other hand, it is not essential to form a plurality of convex portions 152 and concave portions 154, and only one may be used.

  In the present embodiment, both ends in the axial direction of the swing member 120 are fixedly held by the holding portion 180 so that the vibration antinode X is arranged at the central portion in the axial direction of the swing member 120. The antinode X of vibration may be disposed at both axial ends of the swirling member 120 by fixing and holding the central portion in the axial direction by the holding portion 180. In this case, the convex portion 152 and the concave portion 154 may be disposed at both axial end portions of the rotor 140 and the swinging member 120.

  Moreover, in this embodiment, although the convex part 152 and the recessed part 154 are similar shapes as mentioned above, it is not restricted to this. For example, as shown in FIG. 7, the cross-sectional shape of the convex portion 152 may be formed in a rectangular shape that fits into the concave portion 154 having a V-shaped cross section.

  Further, in the present embodiment, the drive unit 130 is configured by the three electromechanical conversion elements 132, 134, and 136, but may be configured by two or four or more electromechanical conversion elements. As shown in FIG. 8, when the drive unit 130 is configured by four electromechanical transducer elements 132, 134, 136, and 138, a sin wave is applied to one of a pair of axially symmetrical electromechanical transducer elements. By applying a drive voltage and applying a cosine wave drive voltage to the other, the swing member 120 can be swung. Thereby, the control of the drive voltage can be simplified.

  Next, another embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure similar to the said embodiment, and description is abbreviate | omitted. FIG. 9 is an exploded perspective view showing the swing member 120 and the annular member 210 of the vibration actuator 200 according to the present embodiment. FIG. 10 is a perspective view showing the swing member 120, the annular member 210, and the like.

  As shown in these drawings, the vibration actuator 200 includes an annular member 210 that covers the entire swing member 120 in the axial direction. The annular member 210 is formed in a cylindrical shape, and an inner peripheral portion thereof is fitted to the entire outer peripheral portion 123 of the swing-out member 120 in the axial direction. Then, the electromechanical conversion elements 132, 134, and 136 are attached to the outer peripheral portion of the annular member 210.

  Thereby, the whole of the swing member 120 in the axial direction is bundled by the annular member 210. Therefore, when the swing member 120 is swinging, it is possible to more reliably prevent a gap from being formed between the adjacent divided pieces 125, and the swing motion of the swing member 120 can be stabilized. .

  Next, an imaging apparatus 700 according to another embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure similar to the said embodiment, and description is abbreviate | omitted. FIG. 11 shows a schematic configuration of the imaging apparatus 700 in a side sectional view.

  The imaging device 700 includes an optical member 420, a lens barrel 430, a focus ring 710, a vibration actuator 100, an imaging unit 500, and a control unit 550. The lens barrel 430 accommodates the optical member 420. The focus ring 710 has an annular shape and moves the optical member 420 with a manual rotational force.

  The vibration actuator 100 moves the optical member 420 and rotates the focus ring 710. The imaging unit 500 captures an image formed by the optical member 420. The control unit 550 controls the vibration actuator 100 and the imaging unit 500.

  The imaging apparatus 700 includes a lens unit 410 including an optical member 420, a lens barrel 430, and the vibration actuator 100, and a body 460. The lens unit 410 is detachably attached to the body 460 via the mount 450.

  The optical member 420 includes a front lens 422, a compensator lens 424, a focusing lens 426, and a main lens 428, which are sequentially arranged from the incident end corresponding to the left side in the drawing. An iris unit 440 is disposed between the focusing lens 426 and the main lens 428.

  The vibration actuator 100 is fixed inside the lens barrel 430 by a fixing member such as a screw in the pair of holding portions 180. The pair of holding portions 180 support the swing member 120 at a node position in the swing vibration of the swing member 120. Thereby, the vibration of the swing member 120 is not transmitted to the lens barrel 430, and the influence of the vibration of the swing member 120 on the imaging device 700 can be reduced.

  The focusing lens 426 has a diameter smaller than the inner diameter of the lens barrel 430 and is arranged in the middle of the lens barrel 430 in the optical axis direction. The vibration actuator 100 is disposed below the focusing lens 426. Accordingly, the vibration actuator 100 is accommodated in the lens barrel 430 without increasing the diameter of the lens barrel 430. The vibration actuator 100 advances or retracts the focusing lens 426 in the optical axis direction through, for example, a gear train. Further, the vibration actuator 100 rotates the focus ring 710 via, for example, a gear train.

  The body 460 accommodates optical members including the main mirror 540, the pentaprism 470, and the eyepiece system 490. The main mirror 540 is located between a standby position inclined on the optical path of incident light incident through the lens unit 410 and an imaging position (indicated by a dotted line in the figure) that rises while avoiding incident light. Moving.

  The main mirror 540 at the standby position guides most of the incident light to the pentaprism 470 disposed above. Since the pentaprism 470 emits a reflection of incident light toward the eyepiece system 490, the image on the focusing screen can be viewed as a normal image from the eyepiece system 490. The remainder of the incident light is guided to the photometric unit 480 by the pentaprism 470. The photometric unit 480 measures the intensity and distribution of incident light.

  A half mirror 492 is disposed between the pentaprism 470 and the eyepiece system 490 to superimpose the display image formed on the finder liquid crystal 494 on the image of the focusing screen. The display image is displayed so as to overlap the image projected from the pentaprism 470.

  The main mirror 540 has a sub mirror 542 on the back surface with respect to the incident surface of the incident light. The sub mirror 542 guides part of the incident light transmitted through the main mirror 540 to the distance measuring unit 530 disposed below. Thereby, when the main mirror 540 is in the standby position, the distance measuring unit 530 measures the distance to the subject. When the main mirror 540 is moved to the photographing position, the sub mirror 542 is also retracted from the optical path of the incident light.

  Further, a shutter 520, an optical filter 510, and an imaging unit 500 are sequentially arranged behind the main mirror 540 with respect to incident light. When the shutter 520 is opened, the main mirror 540 moves to the photographing position immediately before the shutter 520 is opened, so that incident light travels straight and enters the imaging unit 500. Thereby, an image formed by incident light is converted into an electrical signal. Thereby, the imaging unit 500 captures an image formed by the lens unit 410.

  In the imaging device 700, the lens unit 410 and the body 460 are also electrically coupled. Therefore, for example, the autofocus mechanism can be formed by controlling the rotation of the vibration actuator 100 based on the distance information to the subject detected by the distance measuring unit 530 on the body 460 side. Further, when the distance measuring unit 530 refers to the operation amount of the vibration actuator 100, a focus aid mechanism can be formed. The vibration actuator 100 and the imaging unit 500 are controlled by the control unit 550 as described above.

  Although the case where the focusing lens 426 is moved by the vibration actuator 100 has been illustrated, it goes without saying that the vibration actuator 100 can drive the opening / closing of the iris unit 440, the movement of the variator lens of the zoom lens, and the like. Also in this case, the vibration actuator 100 contributes to automating exposure, execution of a scene mode, execution of bracket photography, and the like by referring to information with the photometric unit 480, the finder liquid crystal 494, and the like via an electrical signal.

  By the way, the imaging apparatus 700 is equipped with a so-called M / A mode in which a manual focus operation by the focus ring 710 can be performed during an autofocus operation. That is, the focusing lens 426 is focused by a rotational force generated by manual operation of the focus ring 710 instead of the output of the vibration actuator 100.

  Here, in the vibration actuator 100, since the sliding area between the rotor 140 and the swing member 120 can be increased efficiently, the output of the vibration actuator 100 can be increased efficiently. Accordingly, since a large output can be obtained by the small vibration actuator 100 as compared with the equivalent size, the space occupied by the vibration actuator 100 in the lens unit 410 and the imaging device 700 can be reduced, and thus the lens. The unit 410 and the imaging device 700 can be downsized.

  As described above, the vibration actuators 100 and 200 can be suitably used for driving a focusing mechanism, a zoom mechanism, a camera shake correction mechanism, and the like in an optical system such as a photographing machine and binoculars. Furthermore, it can be used for power sources such as precision stages, more specifically electron beam lithography equipment, various stages for inspection equipment, moving mechanisms for cell injectors for biotechnology, moving beds for nuclear magnetic resonance equipment, etc. Needless to say, it is not limited to.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

The vibration actuator 100 which concerns on embodiment of this invention is shown with a disassembled perspective view. The vibration actuator 100 which concerns on embodiment of this invention is shown with a perspective view. The vibration actuator 100 which concerns on embodiment of this invention is shown with sectional drawing seen from radial direction. 4-4 sectional drawing of FIG. 3 is shown. (A) shows a cross-sectional view of the swirl member 120 viewed from the radial direction. FIG. 5B is a conceptual diagram for explaining the swinging motion of the swinging member 120. The modification of the vibration actuator which concerns on embodiment of this invention is shown with a perspective view. The modification of the convex part 152 and the recessed part 154 is shown with the expanded sectional view seen from radial direction. The modification of the vibration actuator which concerns on embodiment of this invention is shown with a perspective view. The vibration actuator 200 which concerns on other embodiment is shown with an exploded perspective view. The vibration actuator 200 which concerns on other embodiment is shown with a perspective view. 1 is a side sectional view showing a schematic configuration of an imaging apparatus 700 according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Vibration actuator, 102 Notch part, 120 Swing-out member, 121 Inner peripheral part, 123 Outer peripheral part, 125 Dividing piece, 127 Dividing line, 130 Drive part, 132 Electromechanical conversion element, 134 Electromechanical conversion element, 136 Electromechanical Conversion element, 138 Electromechanical conversion element, 140 rotor, 143 outer peripheral portion, 146 gear coupling portion, 151 inclined surface, 152 convex portion, 153 inclined surface, 154 concave portion, 155 inclined surface, 156 annular member, 157 inclined surface, 158 yen Hole, 159 sliding part, 160 bearing plate, 162 tension coil spring, 170 output gear, 172 shaft hole, 180 holding part, 184 mounting hole, 186 opening, 200 vibration actuator, 210 annular member, 410 lens unit, 420 optical member, 422 front lens, 424 Pensator lens, 426 focusing lens, 428 main lens, 430 lens barrel, 440 iris unit, 450 mount, 460 body, 470 pentaprism, 480 photometric unit, 490 eyepiece system, 492 half mirror, 494 finder finder liquid crystal, 500 imaging unit , 510 optical filter, 520 shutter, 530 ranging unit, 540 main mirror, 542 sub mirror, 550 control unit, 700 imaging device, 710 focus ring

Claims (7)

A rotor that rotates about a rotation axis;
A cylindrical swing-around member that is arranged coaxially with the rotor and in which the rotor is slidably inserted around a rotation axis;
A drive unit that swings the swing member;
With
One of an annular convex portion and a concave portion slidably fitted around the rotation axis of the rotor is provided on the outer peripheral portion of the rotor, and the other is provided on the inner peripheral portion of the whirling member. A vibration actuator that rotationally drives the rotor by sliding on the one of the convex portion and the concave portion of the rotor by swinging the other of the convex portion and the concave portion of the member.   The vibration actuator according to claim 1, wherein a plurality of the convex portions and the concave portions are continuously provided in the axial direction of the rotor.   3. The vibration actuator according to claim 1, wherein a sliding portion between the convex portion and the concave portion is an inclined surface that is inclined in an axial direction of the rotor toward an outer diameter side of the rotor.   The sliding portion is an inclined surface that is inclined from the opening side to the bottom side of the concave portion toward the hole wall side of the concave portion facing the sliding portion and the axial direction of the rotor. The vibration actuator according to claim 3.   5. The vibration actuator according to claim 1, wherein the convex portion and the concave portion are arranged at a vibration antinode of the swing member. An optical member;
A lens barrel that houses the optical member;
A vibration actuator that is provided inside the lens barrel and moves the optical member;
A lens unit comprising:
The vibration actuator is
A rotor that rotates about a rotation axis;
A cylindrical swing-around member that is arranged coaxially with the rotor and in which the rotor is slidably inserted around a rotation axis;
A drive unit that swings the swing member;
With
One of an annular convex portion and a concave portion slidably fitted around the rotation axis of the rotor is provided on the outer peripheral portion of the rotor, and the other is provided on the inner peripheral portion of the whirling member. A lens unit that rotationally drives the rotor by sliding to the one of the convex portion and the concave portion of the rotor by swinging the other of the convex portion and the concave portion of the member. An optical member;
A lens barrel that houses the optical member;
A vibration actuator for moving the optical member;
An imaging unit that captures an image formed by the optical member;
A control unit that controls the vibration actuator and the imaging unit;
An imaging device comprising:
The vibration actuator is
A rotor that rotates about a rotation axis;
A cylindrical swing-around member that is arranged coaxially with the rotor and in which the rotor is slidably inserted around a rotation axis;
A drive unit that swings the swing member;
With
One of an annular convex portion and a concave portion slidably fitted around the rotation axis of the rotor is provided on the outer peripheral portion of the rotor, and the other is provided on the inner peripheral portion of the whirling member. An imaging device that slides on the one of the convex portion and the concave portion of the rotor to rotate the rotor by swinging the other of the convex portion and the concave portion of the member.

Images