JP2007110805A - Driver and lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a driver for enabling a repetitive operation of a large movement in a short time and a fine movement in short steps, and a lens barrel for satisfying different requests required when a lens group moves. <P>SOLUTION: The driver is provided with a vibrating body having a plurality of piezoelectric elements disposed so as to intersect each other at a predetermined angle and vibrated by a high-frequency signal, a cylindrical driven member driven by vibration from the vibrating body, a male screw member integrally formed at the driven member, a female screw member screwed to the male screw member. The vibrating body drives the driven member in two directions i. e. the circumferential direction and the height direction of the cylinder, and moves the female screw member. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drive device in which a driven member is moved in two directions using the vibration of a vibrating body.

  2. Description of the Related Art Conventionally, a camera equipped with a single focus photographing lens or a variable focal length photographing lens (hereinafter also referred to as a zoom lens) is commercially available.

  In the case of a single focus photographing lens, it is common to perform focusing by moving a predetermined lens group. In the case of a zoom lens, a plurality of lens groups constituting an optical system are arranged along the optical axis. In general, the focal length is changed (zooming) by moving to a desired position and changing the interval, and a predetermined lens group is moved for further focusing. Furthermore, it is moved from the position where it can be photographed to the retracted position and stored without being bulky, so that it has a compact convenience when carried.

  There are roughly two types of methods for moving the lens group along the optical axis. The lens frame is engaged with the linear guide, and the lens frame is moved linearly by rotating the cam cylinder or helicoid. A shaft is arranged almost in parallel, and this shaft is used as a guide shaft for rectilinear guide. A sleeve through which the guide shaft passes is formed in the lens frame, and the lens frame is slid directly along the guide shaft using a motor and a lead screw. There is something that lets you move straight ahead.

  A DC motor or a stepping motor is generally used as a drive source for moving these lens groups.

  Conventionally, there has been known a driving device that vibrates a vibrating body by applying an AC voltage to a piezoelectric element or the like, and relatively moves the driven body by a frictional force by repeatedly contacting and separating from the vibrating body. It has been.

As an actuator of such a driving device, a vibrating body is used in which the displacement directions of two stacked piezoelectric elements intersect at a predetermined angle, and the drive member provided at the intersection of the displacement directions of the elements has an elliptical orbit. As illustrated, an actuator is known in which each element is driven by an AC voltage signal having a predetermined phase difference, and a driven member with which the driving member abuts is rotated in a predetermined direction (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 2001-190081

  In the camera, preferable conditions are different in each of the movement of the lens group from the retracted state to the photographing enabled state, the movement of the lens group during zooming, and the movement of the lens group during focusing. In other words, when moving the lens group from the retracted state to the imageable state, it is required to move quickly in a short time with respect to the large amount of movement from the retracted position to the imageable position. In this case, the total movement amount is smaller than that of the retracted lens, but an operation that repeats the movement in small steps with a minute movement amount is required. In addition, when moving the lens group during zooming, it varies depending on the lens configuration, when it is required to move quickly in a short time, when it is required to repeat the movement in small steps with a small amount of movement. .

  However, a conventional drive device using a cam cylinder or helicoid or a drive device using a motor and a lead screw can satisfy one of the different requirements, but it is difficult to satisfy both.

  The actuator described in Patent Document 1 can drive a cylindrical driven body at high speed and without noise, but there is still room for further application development as a driving device.

  SUMMARY OF THE INVENTION In view of the above problems, the present invention has an object to provide a driving device that can move quickly in a short time with respect to a large amount of movement, and that can repeatedly move in small steps with a small amount of movement. It is an object of the present invention to obtain a lens barrel that can satisfy both different requirements required for group movement.

  The above problem is solved by the following configuration.

  1) A plurality of piezoelectric elements arranged so as to intersect with each other at a predetermined angle, a vibrating body that vibrates based on a high-frequency signal, a cylindrical driven member that is driven by the vibration of the vibrating body, and the driven member An externally formed male screw member and a female screw member screwed into the male screw member, and the vibrator drives the driven member in two directions, a circumference and a cylinder height direction. The drive device is characterized by moving the female screw member.

  2) In a driving device including a vibrating body that is arranged to intersect a plurality of piezoelectric elements at a predetermined angle and vibrates based on a high-frequency signal, and a cylindrical driven member that is driven by the vibration of the vibrating body. The vibration device includes four piezoelectric elements arranged in a cross shape when viewed from the driven member side, and drives the driven member in two directions.

  3) The driving device according to 1) or 2), wherein the driving amount of the driven member in two directions is detected by one detection member.

  4) The driving device according to any one of 1) to 3), wherein a checkered pattern is formed on the driven member, and the detection member is a photo reflector.

  5) A lens mirror comprising the driving device according to any one of 1) to 4), wherein at least two operations among a collapsing operation, a zooming operation, and a focusing operation are performed by driving the driven member in two directions. Torso.

  According to the present invention, it is possible to obtain a drive device that can move quickly in a short time with respect to a large amount of movement, and that can repeatedly move in small steps with a small amount of movement. It is possible to obtain a lens barrel that can satisfy both of the different demands required in the process.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited thereto.

  FIG. 1 is a front view schematically showing a known vibration actuator in which a plurality of piezoelectric elements are arranged to cross each other at a predetermined angle.

  As shown in the figure, the vibration actuator includes a vibrating body 60 that is a driving source, a driven member 66 that is a driven body that is driven by the vibrating body 60, a pressurizing member 64 that is configured by an elastic member, A pedestal 65 is provided.

  The vibrating body 60 includes two piezoelectric elements 62a and 62b, a chip member 61, and a base member 63, and the vibrating body 60 vibrates in response to application of a high frequency voltage (high frequency signal).

  The two piezoelectric elements 62 a and 62 b are arranged so as to intersect at a substantially right angle as shown in the figure, and the intersecting side ends are joined to the chip member 61. The other ends of the piezoelectric elements 62 a and 62 b are joined to the base member 63. The tip member 61 is preferably formed of a material having a stable high friction coefficient and high wear resistance (for example, a metal material such as cemented carbide). The base member 63 is preferably formed of a material that is easy to manufacture and has high strength (for example, a metal material such as stainless steel). The piezoelectric elements 62a and 62b are fixed to the chip member 61 and the base member 63 with an adhesive. As this adhesive, it is preferable to use an epoxy resin adhesive having excellent adhesive strength.

  The two piezoelectric elements 62a and 62b are stacked piezoelectric elements, and have a structure in which a plurality of ceramic thin plates and electrodes having piezoelectric characteristics are alternately stacked. The piezoelectric elements 62a and 62b are displacement elements that expand and contract in the stacking direction in accordance with an applied voltage. Specifically, the piezoelectric elements 62a and 62b expand when a voltage with a predetermined sign is applied, and contract when a voltage with an opposite sign is applied. For this reason, if an alternating voltage is applied, expansion and contraction is repeated according to the period of the alternating voltage. Therefore, the vibrating body 60 can be vibrated by applying an AC voltage having a phase difference to the two piezoelectric elements 62a and 62b.

  FIG. 2 is a diagram showing a driving operation of the vibrating body 60 shown in FIG. In addition, in the figure shown below, in order to avoid duplication of description, the same code | symbol is provided and demonstrated to the same function member.

  As shown in the figure, by driving the two piezoelectric elements 62a and 62b of the vibrating body 60 with an alternating voltage having a phase difference, the tip member 61 of the vibrating body 60 can be elliptically moved.

  FIG. 4A shows the movement locus of the tip member 61 when the phase difference is 60 °, and FIG. 4B shows the movement locus of the tip member 61 when the phase difference is 90 °. (C) has shown the movement locus | trajectory of the chip | tip member 61 in case a phase difference is 120 degrees. As shown in the figure, when the phase difference is set to 90 °, the tip member 61 has a circular motion. By changing the phase difference, the motion locus of the tip member 61 can be set to a desired shape.

  As described above, the vibration actuator moves the driven member 66 using the movement locus of the tip member 61 of the vibrating body 60.

  That is, the driven member 66 contacts the tip member 61 of the vibrating body 60, and the driving force of the vibrating body 60 is directly transmitted. Specifically, the driven member 66 is driven by the frictional force generated between the driven member 66 and the chip member 61 while repeating contact (collision) with the chip member 61 and separation of the chip member 61 according to the vibration of the vibrating body 60. Is done. In other words, the driven member 66 is driven by repeating a minute movement operation involving frictional contact between the tip member 61 of the vibrating body 60 and the surface of the driven member 66.

  FIG. 3 is a diagram illustrating an example of a vibrating body 70 used in the drive device according to the present embodiment. 4A is a perspective view of the vibrating body 70, FIG. 2B is a view of the vibrating body 70 as seen from the tip member side, that is, the driven member side, and FIG. It is the figure which looked at from the side.

  As shown in the figure, the vibrating body 70 used in the drive device according to the present embodiment has four piezoelectric elements 62a, 62b, 62c, and 62d. As shown in FIG. 62b, 62c, and 62d are arranged so as to intersect each other at substantially right angles, the crossing side ends are joined to the chip member 61, and the other ends of the piezoelectric elements are joined to the base member 63.

  Further, as shown in FIG. 5B, the piezoelectric elements 62a and 62b and the piezoelectric elements 62c and 62d are arranged in a cross shape when viewed from the chip member side, that is, the driven member side.

  For the four piezoelectric elements arranged as shown in the figure, for example, an AC voltage having a phase difference of 90 ° is applied to the piezoelectric elements 62a and 62b, and the piezoelectric elements 62a and 62b are elliptically moved to the piezoelectric elements 62c and 62d. AC with a phase difference of 0 ° so that the piezoelectric elements 62c and 62d are fully extended at the timing when the piezoelectric elements 62c and 62b are fully contracted at the timing when the piezoelectric elements 62a and 62b are positioned at the lowest point of the elliptical motion. By applying a voltage, elliptical motion can be performed in the direction of arrow A shown in FIG.

  Similarly, an AC voltage having a phase difference of 90 °, for example, is applied to the piezoelectric elements 62c and 62d, and the piezoelectric elements 62a and 62b are applied to the piezoelectric elements 62a and 62b at the timing when the piezoelectric elements 62c and 62d are positioned at the highest point of the elliptical motion. By applying an AC voltage with a phase difference of 0 ° so that the piezoelectric elements 62a and 62b are fully contracted at the timing when the piezoelectric elements 62c and 62d are positioned at the lowest point of the elliptical motion, the piezoelectric element 62c and 62d are fully extended. Ellipse motion can be performed in the direction of arrow B shown in FIG.

  As a result, the driven member 66 shown in FIG. 5C can be moved in the two directions indicated by arrows A and B.

  In this way, the four piezoelectric elements are arranged in a cross shape when viewed from the driven member side, and by controlling the AC voltage applied to each, the two vibrators are not arranged in two directions, respectively. A vibrating body capable of moving the driven member in two directions can be obtained, and the driving apparatus can be reduced in size by using this vibrating body.

  FIG. 4 is a perspective view showing an example of the driving device 80 according to the present embodiment.

  In the figure, reference numeral 70 denotes the vibrating member shown in FIG. 3, and 66 denotes a driven member driven by the vibrating member 70.

  The vibrating body 66 is held by the frame 72 and is electrically connected (not shown) so that the AC voltage can be applied. Further, the frame 72 is fixed to other constituent members.

  The driven member 66 is cylindrical as shown in the figure, and a male screw member 71 (hereinafter also referred to as a lead screw) having a male screw portion is integrally formed on the central axis of the cylindrical driven member 66. Yes. The cylindrical driven member 66 and the male screw member 71 may be formed as separate parts and then integrally joined by bonding, press fitting, spline coupling, key coupling, or the like, or formed as an integral part. It may be a thing.

  A thin shaft portion 71j is formed at both ends of the male screw member 71, and the thin shaft portion 71j is held by the frame 72 by penetrating through a hole formed in the frame 72. The thin shaft portion 71j is formed to have a sufficient length so as to be slidable in the axial direction without being detached from the frame 72. That is, the integrally formed driven member 66 and male screw member 71 can be rotated about the thin shaft portion 71j while being held by the frame 72, and can also move straight in the axial direction of the thin shaft portion 71j. It is possible.

  A female screw member 73 is screwed into the lead screw 71, and is not shown but is rotationally locked. Thus, the female screw member 73 moves in the axial direction of the lead screw 71 by the rotation of the lead screw 71, that is, the rotation of the driven member 66, and accompanying the movement of the lead screw 71 and the driven member 66 in the axial direction. It can also be moved.

  Further, as shown in the drawing, a checkered black and white pattern is formed on the outer periphery of the cylindrical portion of the driven member 66. This pattern is formed so that the light reflectance is different between the white portion and the black portion, and a photo reflector 74 is arranged to face the checkered pattern. With this two-dimensional checkered black and white pattern, the movement of the driven member 66 in the two directions of the amount of movement in the cylindrical height direction and the amount of rotation in the circumferential direction (rotation angle) is reduced to one. It can be detected by the output of the photo reflector 74.

  The checkered black and white pattern is not limited to the pattern having the same pitch in the cylinder height direction and the circumferential direction as shown in the figure, but is a pattern having a different pitch in the cylinder height direction and the circumferential direction. Of course, it may be.

  FIG. 5 is a plan view of the driving device 80 shown in FIG. 4A shows a state in which the driven member 66 and the lead screw 71 have moved to the right end with respect to the frame 72, and FIG. 4B shows a state in which the driven member 66 and the lead screw 71 have moved to the left end with respect to the frame 72. Indicates the state.

  The movement from the state shown in FIG. 6A to the state shown in FIG. 5B is performed by driving the tip member 61 of the vibrating body 70 in the left-right direction on the paper surface of the drawing, and the lead screw 71 is rotated. The female screw member 73 can be moved in the left direction in the figure without any problem. Further, the female screw member 73 can be moved rightward in the drawing by driving the tip member 61 in the reverse direction. Furthermore, the driven member 66 and the lead screw 71 are rotated by driving the chip member 61 of the vibrating body 70 in the front and back direction of the drawing, and the female screw member 73 to be screwed can be moved.

  That is, by moving the driven member 66 linearly in the cylindrical height direction, the female screw member 73 can be moved quickly and with a large amount of movement in a short time, and the driven member 66 is rotated in the circumferential direction. By rotating the lead screw 71, it is possible to obtain a drive device capable of finely and precisely controlling the movement of the female screw member 73 to be screwed.

  In addition, the above-described driving device appropriately sets the range of the driven member 66 in the cylindrical height direction and the threaded portion of the lead screw 71, so that the total movement amount due to the movement in the cylindrical height direction and the rotation of the lead screw 71 The total amount of movement is set to an optimum condition corresponding to the equipment to be used.

  FIG. 6 is a schematic diagram illustrating an example of a lens barrel using the driving device 80 according to the present embodiment. 4A shows the retracted state, FIG. 2B shows the wide state, and FIG. 3C shows the tele state.

  In the figure, reference numeral 1 denotes a first lens group, and 1k denotes a first lens group frame, which holds the first lens group 1. Reference numeral 2 denotes a second lens group, and 2k denotes a second lens group lens frame, which holds the second lens group 2. An optical filter 7 has functions of an optical low-pass filter and an infrared light cut filter. Reference numeral 8 denotes an image pickup device, and a CCD (Charge Coupled Device) type image sensor, a CMOS (Complementary Metal-Oxide Semiconductor) type image sensor, or the like is used. The first lens group lens frame 1k and the second lens group lens frame 2k are guided by a guide shaft (not shown) and can move in the direction of the optical axis O. In the figure, the aperture shutter unit assembled to the second lens group frame 2k is omitted.

  The first lens group lens frame 1k has a female screw portion, and is screwed with a lead screw 71 of a driving device 80 similar to that shown in FIG. The second lens group lens frame 2k is moved in the direction of the optical axis O by the vibration actuator 60 shown in FIG.

  The movement from the retracted state shown in FIG. 5A to the wide state shown in FIG. 5B is performed as follows.

  First, the vibrating body 70 is driven in a direction in which the driven member 66 moves linearly in the cylindrical height direction, and the first lens group frame 1k is fed forward by a predetermined amount together with the lead screw 71. The amount by which the first lens group frame 1k is moved out is such that the cylindrical height of the checkered pattern on the outer periphery of the driven member 66 from the position where the driven member 66 shown in FIG. The movement in the vertical direction is detected by a photo reflector 74 and controlled based on the detection result. Further, the vibrating body 60 is driven to extend the second lens group lens frame 2k by a predetermined amount, so that the wide state is achieved. Although the drawing amount of the second lens group frame 2k is not shown, for example, the N pole and the S pole are alternately formed in the rotation direction, and a magnetic thin film resistance element as a detection member is used at a corresponding position, thereby forming a magnetic thin film. Control is performed by detecting an output signal that is output along with the movement of the resistance element by arithmetic processing.

  In focusing in the wide state shown in FIG. 5B, the vibrating body 70 is driven in a direction in which the driven member 66 is rotated in the circumferential direction, and the first lens group frame 1k that is screwed by the rotation of the lead screw 71 is used. Is performed in the direction of the optical axis O. The amount of movement of the first lens group frame 1k due to focusing is controlled based on the detection result obtained by detecting the rotation in the circumferential direction of the checkered pattern on the outer periphery of the driven member 66 by the photo reflector 74. It has become.

  Movement from the wide state shown in FIG. 5B to the tele state shown in FIG. 4C is performed as follows.

  The vibrating body 70 is driven in a direction in which the driven member 66 is rotated in the circumferential direction, and the first lens group frame 1k to be screwed is moved in the optical axis O direction by the rotation of the lead screw 71 (in the drawing direction, in the drawing). Further, the vibrating body 60 is driven to extend the second lens group frame 2k by a predetermined amount, and the tele state is obtained.

  In the tele state focusing shown in FIG. 5C, the vibrating body 70 is driven in the direction of rotating the driven member 66 in the circumferential direction and screwed by the rotation of the lead screw 71 as in the wide state. This is done by moving the first lens group frame 1k in the direction of the optical axis O. The amount of movement of the first lens group frame 1k due to focusing is controlled based on the detection result obtained by detecting the rotation in the circumferential direction of the checkered pattern on the outer periphery of the driven member 66 by the photo reflector 74. It has become.

  Further, the movement from the telephoto state of FIG. 10C to the wide state of FIG. 10B and the movement from the wide state of FIG. 10B to the retracted state of FIG. This is done by reversing.

  That is, the lens barrel shown in FIG. 6 performs a collapsing operation by moving the driven member 66 of the driving device 80 in the cylindrical height direction, and a zooming operation by rotating the driven member 66 in the circumferential direction. Focusing operation is performed. By doing so, different movements required when moving the lens group, a large amount of movement during retraction is quickly moved in a short time, and a small amount of movement during focusing is repeated in small increments. It is possible to obtain a lens barrel that can satisfy both of the operations.

  In the above example, the zooming operation is described by rotating the driven member 66 in the circumferential direction. However, for the zooming operation of the first lens group between the wide and telephoto, the driven member 66 is a cylinder. You may make it carry out by moving to a height direction. Further, the first lens barrel 1k is moved by the vibration actuator 60 shown in FIG. 1, and the second lens group barrel 2k is driven by the driving device 80, and the driven member 66 is rotated in the circumferential direction. Thus, focusing may be performed by the second lens group.

  Hereinafter, another example of a lens barrel provided with the driving device 80 will be described.

  FIG. 7 is a cross-sectional view showing a foldable imaging optical system capable of zooming. FIG. 4A is a cross-sectional view taken along a plane including two optical axes before and after bending. FIG. 4B is a movement diagram of each lens group during zooming.

  As shown in FIG. 2A, OA is the optical axis before bending, and OB is the optical axis after bending. Reference numeral 1 denotes a first lens group. The first lens group 1 includes a prism 11 that is a reflection member that bends the optical axis OA in a substantially right angle direction, a lens 11 that is disposed toward the subject with the optical axis OA, and a prism 12. The lens 13 is disposed with the optical axis OB bent by the optical axis as the optical axis. The first lens group 1 is a lens group fixed to the main body 9.

  Reference numeral 2 denotes a second lens group, which is incorporated in the second lens group frame 2k. The second lens group is a lens group that moves together with the second lens group frame 2k during zooming (hereinafter also referred to as zooming).

  Reference numeral 3 denotes a third lens group, which is fixed to the main body 9. The third lens group 3 is a lens group that does not move.

  Reference numeral 4 denotes a fourth lens group, which is incorporated in the fourth lens group frame 4k. The fourth lens group is a lens group that moves together with the fourth lens group frame 4k during zooming.

  Reference numeral 5 denotes a fifth lens group, which is incorporated in the fifth lens group frame 5k. The fifth lens group is a lens group that moves integrally with the fifth lens group frame 5k during zooming.

  Reference numeral 6 denotes a sixth lens group, which is fixed to the main body 9. The sixth lens group 6 is a lens group that does not move.

  An optical filter 7 is assembled to the main cylinder 9. Reference numeral 8 denotes an image sensor. The image sensor 8 is assembled to the main body 9. The FPC is a flexible printed circuit board that is connected to the image sensor 8 and connected to other circuits in the camera. S is an aperture shutter unit, which is fixed to the main cylinder 9.

  As shown in FIG. 4B, the first, third, and sixth lens groups are fixed lens groups, and the second, fourth, and fifth lens groups are between wide (W) and tele (T). The zooming is performed by moving as shown. The fifth lens group is further moved from the position moved by zooming to perform focusing.

  FIG. 8 is a schematic diagram showing an example in which the driving device 80 is used in the lens barrel shown in FIG. The figure schematically shows the drive device 80 arranged outside the lens barrel.

  The inside of the lens barrel shown in the figure is a sleeve 2s formed integrally with the second lens group frame 2k, a sleeve 4s formed integrally with the fourth lens group frame 4k, and a fifth lens group mirror. A guide shaft 15 is provided through a rotation locking portion 5m formed integrally with the frame 5k. Further, a rotation locking portion 2m formed integrally with the second lens group lens frame 2k, a rotation locking portion 4m formed integrally with the fourth lens group lens frame 4k, and a fifth lens group lens frame 5k. A guide shaft 16 is provided through the integrally formed sleeve 5s. Thereby, the second lens group lens frame 2k, the fourth lens group lens frame 4k, and the fifth lens group lens frame 5k are slidable along the guide shafts 15 and 16 in the optical axis OB direction. Each sleeve is fitted with a guide shaft, and the guide shafts 15 and 16 are disposed substantially in parallel with the optical axis OB, and are fixed to the main body 9 by bonding or the like at both ends thereof.

  Female sleeve members 23 and 24 that engage with the lead screw and are moved along the guide shafts 15 and 16 in the direction of the optical axis OB by the rotation of the lead screw are engaged with the sleeve 2s and the sleeve 4s, respectively. Yes. The female screw member 25 is engaged with the sleeve 5s.

In the first motor 20, a lead screw 20r, which is a male screw member, is disposed on an extension line of the rotating shaft. In the lead screw 20r, a first screw groove 20r ₁ and a second screw groove 20r ₂ having different pitches and screw advance directions are formed on one shaft. The lead screw 20r having the first and second screw grooves 20r ₁ and 20r ₂ may be individually manufactured and joined to be integrated, or may be processed from an integrated shaft.

The female screw member 23 is screwed into the first screw groove 20r ₁ of the lead screw 20r, and moves the second lens group frame 2k to be engaged in the direction of the optical axis OB. Similarly, female screw member 24, the second screw groove 20r ₂ and screwed of the lead screw 20r, moving the fourth lens group holding frame 4k which engages the optical axis OB direction.

  As a result, the second lens group 2 and the fourth lens group 4 approach the third lens group 3 from both sides with different movement amounts due to the rotation of the first motor 20 in a predetermined direction, and the reverse direction of the first motor 20. Are rotated so as to be separated from the third lens group 3 by different movement amounts.

  On the other hand, the female screw member 25 is screwed into the lead screw 71 of the driving device 80. The fifth lens group 5 moves during zooming by driving the vibrating body 70 in a direction in which the driven member 66 moves straight in the cylindrical height direction, and the lead lens 71 and the fifth lens group frame 5k in the optical axis OB direction. It is done by moving. The amount of movement of the fifth lens group frame 5k is controlled by detecting the movement in the cylindrical height direction of the checkered pattern on the outer periphery of the driven member 66 by the photo reflector 74.

  The focusing is performed by driving the vibrating body 70 in a direction in which the driven member 66 is rotated in the circumferential direction and moving the fifth lens group frame 5k in the optical axis OB direction by the rotation of the lead screw 71. . The amount of movement by focusing of the fifth lens group frame 5k is controlled based on the detection result obtained by detecting the circumferential rotation of the checkered pattern on the outer periphery of the driven member 66 by the photo reflector 74. It has become.

  Thereby, the second lens group, the fourth lens group, and the fifth lens group can be moved along the movement diagram of wide (W) to tele (T) shown in FIG. Focusing by the fifth lens group is also possible.

  Reference numerals 32 and 35 are photo interrupters. The photo interrupter 32 detects the initial position for positioning the second lens group frame 2k by detecting the switching position of the presence or absence of the shielding portion formed on the second lens group frame 2k. The photo interrupter 35 detects an initial position for positioning the fifth lens group frame 5k by detecting a switching position of the presence or absence of a shielding portion formed on the fifth lens group frame 5k.

  The rotation direction and amount of rotation of the first motor 20 are controlled based on this initial position, and the position control of the second and fourth lens groups is performed. Further, the movement of the checkered pattern on the outer periphery of the driven member 66 of the driving device 80 in the cylindrical height direction is detected by the photo reflector 74 with reference to the initial position, and the zooming position control is performed. Yes.

  That is, the lens barrel shown in FIG. 8 performs a zooming operation by moving the driven member 66 of the driving device 80 in the cylindrical height direction, and performs a focusing operation by rotating the driven member 66 in the circumferential direction. To do. By doing this, different movements required when moving the lens group, a large amount of movement during zooming is quickly moved in a short time, and a small amount of movement during focusing is repeated in small increments. It is possible to obtain a lens barrel that can satisfy both of the operations.

  As another lens barrel configuration, a three-group zoom configuration in which the first lens group and the second lens group on the object side are retracted and zoomed by the cam barrel, and the third lens group on the image plane side is retracted. In addition, the driving device according to the present embodiment can be applied to the movement of the third lens group even in a configuration in which a small amount of movement is performed during zooming and focusing is performed. In this case, when retracting and zooming, the driven member is moved straight in the cylinder height direction to move the third lens group, and during focusing, the driven member is rotated in the circumferential direction to rotate the lead screw. The third lens group is moved by moving the third lens group by moving the driven member straight in the cylinder height direction when retracted, and the driven member is rotated in the circumferential direction during zooming and focusing. The third lens group may be moved by rotating the lead screw.

  The driving device according to the present embodiment has been described using the vibrator described in FIG. 3, but is not limited thereto, and the linear movement and circumference of the driven member in the cylindrical height direction are not limited thereto. It is needless to say that the rotation in the direction may be arranged in accordance with the respective driving directions using two vibrating bodies shown in FIG. In this case, for example, an AC voltage having a phase difference of 90 ° is applied to one vibrating body, and the other vibrating body is subjected to timing when the tip member of one vibrating body is positioned at the highest point of the elliptical motion. Phase difference 0 such that the tip member of the vibrating body is positioned at the lowest point and the tip member of one vibrating body is positioned at the lowest point of the elliptical motion, the tip member of the other vibrating body is positioned at the highest point. An AC voltage of ° may be applied.

It is the front view which showed typically the well-known vibration actuator which has arrange | positioned the several piezoelectric element at the predetermined angle mutually. FIG. 6 is a diagram illustrating a driving operation of the vibrating body 60 illustrated in FIG. 1. It is a figure which shows an example of the vibrating body 70 used for the drive device which concerns on this Embodiment. It is a perspective view which shows an example of the drive device 80 which concerns on this Embodiment. It is a top view of the drive device 80 shown in FIG. It is a schematic diagram which shows an example of the lens barrel using the drive device 80 which concerns on this Embodiment. It is sectional drawing which shows the bending imaging optical system which can be changed in magnification. It is a schematic diagram which shows the example which used the drive device 80 for the lens barrel shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st lens group 1k 1st lens group frame 2 2nd lens group 2k 2nd lens group frame 3 3rd lens group 4 4th lens group 4k 4th lens group frame 5 5th lens group 5k 5th lens Group lens frame 6 Sixth lens group 7 Optical filter 8 Image sensor 9 Main body 15, 16 Guide shaft 20 First motor 61 Chip member 62a, 62b, 62c, 62d Piezoelectric element 63 Base member 64 Pressure member 66 Driven member 70 Vibrating body 71 Male thread member (lead screw)
72 Frame 73 Female thread member 74 Photo reflector 80 Drive device

Claims (5)

A plurality of piezoelectric elements arranged so as to cross each other at a predetermined angle, a vibrating body that vibrates based on a high-frequency signal, a cylindrical driven member that is driven by the vibration of the vibrating body, and the driven member integrally A male screw member formed, and a female screw member screwed into the male screw member,
The vibrator is configured to drive the driven member in two directions of a circumference and a cylinder height direction to move the female screw member. In a driving device comprising: a vibrating body that is arranged to intersect a plurality of piezoelectric elements at a predetermined angle and vibrates based on a high-frequency signal; and a cylindrical driven member that is driven by the vibration of the vibrating body.
The vibration device includes four piezoelectric elements arranged in a cross shape when viewed from the driven member side, and drives the driven member in two directions. The driving device according to claim 1, wherein the driving amount of the driven member in two directions is detected by one detection member. The driving device according to claim 1, wherein a checkered pattern is formed on the driven member, and the detection member is a photo reflector. 5. The driving apparatus according to claim 1, wherein the driven member performs at least two of a collapsing operation, a zooming operation, and a focusing operation by driving the driven member in two directions. Lens barrel.

Images