WO2014061193A1

WO2014061193A1 - Drive device and imaging device

Info

Publication number: WO2014061193A1
Application number: PCT/JP2013/005337
Authority: WO
Inventors: 松尾　隆; 豊年川崎; 拓真森川
Original assignee: コニカミノルタ株式会社
Priority date: 2012-10-19
Filing date: 2013-09-09
Publication date: 2014-04-24
Also published as: JPWO2014061193A1; JP5618028B2

Abstract

This drive device has a moving body sliding therein, said moving body being engaged by a prescribed friction force to a drive shaft that transmits mechanical energy from an electromechanical conversion element. The drive device comprises a device main body that holds the electromechanical conversion element. The moving body comprises: a moving body main body section to which a driven body is attached; first and second sliding surfaces that slide along the drive shaft; and a pressing member that presses the drive shaft onto the first and second sliding surfaces. At least one of the first and second sliding surfaces is configured so as to be movable relative to the moving body main body section. The imaging device pertaining to the present invention uses this drive device.

Description

Driving device and imaging device

The present invention relates to a driving apparatus suitably used for an imaging apparatus that can be mounted on, for example, a mobile phone, and an imaging apparatus using the driving apparatus.

2. Description of the Related Art Conventionally, a drive device called “SIDM (Smooth Impact Drive Mechanism,“ SIDM ”is a registered trademark)” is known as a drive device suitably used for an imaging device that can be mounted on, for example, a mobile phone. This SIDM drive device includes a piezoelectric element that is an electromechanical conversion element, a drive shaft that is joined to one end of the piezoelectric element, and a moving body that is frictionally engaged with the outer periphery of the drive shaft. In such a SIDM drive device, the expansion and contraction of the piezoelectric element is transmitted to the drive shaft, and the moving body engaged with the drive shaft with a predetermined frictional force is applied when the piezoelectric element is expanded and contracted. Drive by using the speed difference. More specifically, in such a drive device, for example, by slowly extending the drive shaft, the moving body frictionally engaged with the drive shaft is also driven and moved, while the predetermined frictional force is exceeded. When the drive shaft is instantaneously reduced, the moving body is left in the extended position. By repeatedly performing such expansion and contraction of the drive shaft, the drive device can drive the movable body in the axial direction of the drive shaft.

In such a drive device, for example, when an impact force due to a drop is applied to a mobile phone equipped with the drive device, an external force is also applied to the moving body frictionally engaged with the drive shaft. If the external force is transmitted to the drive shaft as it is, the drive shaft may be inclined or misaligned.

Further, in such a drive device, for example, in Patent Document 1, a piezoelectric element is held by a fixed frame via a support member, and is connected to the piezoelectric element in the axial direction of the drive shaft, and A driving device is disclosed in which each of the tip side opposite to the piezoelectric element is supported by a partition unit integrated with a fixed frame. In this way, when both end sides of the drive shaft in the axial direction are supported by the partition portion, the possibility that the drive shaft is inclined or misaligned even when an external force is applied to the drive shaft can be reduced.

However, in the configuration in which the proximal end side and the distal end side in the axial direction of the drive shaft are supported by the partition portions as in Patent Document 1, the drive shaft is divided into the partition portions on the proximal end side and the distal end side, respectively. A part to be supported is required. As a result, the axial length of the drive shaft becomes long. In addition, a partition that supports the front end side of the drive shaft is disposed on the front end side of the drive shaft. Therefore, the height of the entire drive device corresponding to the axial direction of the drive shaft is increased, and it is difficult to reduce the height.

JP 2007-274777 A

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a drive device in which the external force is not easily transmitted from the mobile body to the drive shaft even when an external force is applied to the mobile body. It is to provide an imaging apparatus used.

A drive device according to the present invention is a device body in which a movable body engaged with a predetermined friction force slides on a drive shaft that transmits mechanical energy by an electromechanical transducer, and holds the electromechanical transducer. Is provided. The movable body includes a movable body main body to which a driven body is attached, first and second sliding surfaces that slide on the driving shaft, and the driving shaft on the first and second sliding surfaces. A pressing member for pressing, and at least one of the first and second sliding surfaces is configured to be movable with respect to the movable body main body. And the imaging device concerning this invention uses this drive device.

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

It is a perspective view of the drive device in an embodiment. It is a disassembled perspective view of the drive device shown in FIG. It is a perspective view of the drive main-body part used for the drive device shown in FIG. It is a perspective view of the holding member used for the drive device shown in FIG. It is a perspective view of the movable body main-body part used for the drive device shown in FIG. It is a top view of the mobile body main-body part shown in FIG. It is a perspective view of the guide spring used for the drive device shown in FIG. It is a top view of the guide spring shown in FIG. It is a top view in the state where the cover of the drive unit shown in FIG. 1 was removed. It is explanatory drawing of the connection part of the electrode terminal and piezoelectric element in the drive device shown in FIG. It is a perspective view of the connection state of the said mobile body main-body part and the said guide spring in the drive device shown in FIG. It is explanatory drawing at the time of connecting the said mobile body main part and guide spring in a drive device shown in FIG. 1 using a jig | tool. It is sectional drawing which abbreviate | omitted the cover of the imaging device which has a drive device shown in FIG. It is explanatory drawing of the state which the mobile body in the drive device shown in FIG. 1 received the force of the direction which goes to a 2nd corner part from a 4th corner part. In the drive device shown in FIG. 1, it is a figure for demonstrating the moving body of another aspect. In the drive device shown in FIG. 1, it is a figure for demonstrating the moving body of another aspect.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably. In the present specification, when referring generically, it is indicated by a reference symbol without a suffix, and when referring to an individual configuration, it is indicated by a reference symbol with a suffix. In the following description, the X direction shown in FIGS. 1 to 5, 7 and 10 to 13 is the upper side, and the Y direction is the lower side.

1 to 14, the driving device 1 of the present embodiment is suitably used for an imaging device that can be mounted on, for example, a mobile phone. As shown in FIGS. 1 and 2, the drive device 1 of this embodiment includes device main bodies 2 and 8, a drive main body portion 3 held by the device main body, and a moving body 4.

The apparatus main body includes a holding member 2 and a cover 8. The holding member 2 is a base member that holds and supports the drive main body 3, and is formed of a resin material such as LCP (liquid crystal polymer), and as shown in FIG. It is formed by injection molding in a shape in which is inserted. The holding member 2 of this embodiment is a cylindrical body having a rectangular outer periphery and having a circular through hole 20g serving as an optical path at the center.

The holding member 2 is provided with a first support column 20a that is erected along the X direction from the upper surface (one surface) 2e of the cylindrical body at the first corner 2a (lower left side in FIG. 4). The holding member 2 includes a drive main body holding portion 21 that holds the drive main body portion 3 inside the first support pillar 20a in the first corner portion 2a.

The drive main body holding portion 21 is formed so as to be recessed in a cylindrical shape with a predetermined depth from the upper surface 2 e of the holding member 2.

The holding member 2 has the front end 22a of the first electrode terminal 22 and the front end 23a of the second electrode terminal 23 facing each other on both sides of the drive main body holding portion 21 at the first corner 2a. The holding member 2 is disposed so as to protrude upward.

The first and

second electrode terminals

22 and 23 are each embedded in the holding member 2 at the intermediate portions thereof, and the base ends of the first and

second electrode terminals

22 and 23 are respectively external surfaces of the holding member 2. The

external connection terminals

22b and 23b are provided. And the circuit board and connector of the mobile phone which are not shown in which this drive device 1 is mounted, and these

external connection terminals

22b and 23b are mutually connected.

In this embodiment, as shown in FIG. 10, the external connection terminal 22b of the first electrode terminal 22 and the external connection terminal 23b of the second electrode terminal 23 are flush with the lower surfaces of the

external connection terminals

22b and 23b, respectively. It bends and forms through the step part. With this configuration, the external connection terminal 22b of the first electrode terminal 22 and the external connection terminal 23b of the second electrode terminal 23 can be connected to the circuit board so as to be energized, for example, by being placed on the circuit board of a mobile phone.

As shown in FIG. 4, the holding member 2 is provided with the cylinder on each of the second corner portion 2 b on the right front side, the third corner portion 2 c on the right rear side, and the fourth corner portion 2 d on the left rear side. A second support column (an example of a movement restricting portion) 20b, a third support column 20c, and a fourth support column 20d are provided so as to stand along the X direction from the upper surface (one surface) 2e of the body. The third support pillar 20c is formed with a restricting portion receiving groove 29 for receiving a rotation restricting portion 61a of the moving body 4 described later so as to be movable in the vertical direction. In the present embodiment, the first to fourth corner portions 2a to 2d are formed integrally with the cylindrical body.

Next, the cover 8 will be described with reference to FIGS. The cover 8 of the present embodiment is formed into a box shape with one surface (lower surface) opened by drawing or pressing a thin plate made of stainless steel having a thickness of 0.1 mm to 0.2 mm, for example. Through-hole 82 is provided. The through hole 82 has a shape corresponding to the shape of the optical path in the lens barrel 7 and is, for example, a circular shape.

The cover 8 is provided with a locking hole 84 for locking to a locking projection 20f provided on the side surface of the holding member 2 on each of the four side walls 83. In this embodiment, the number of the locking projections 20f is two, and the locking projections 20f are locked with the two locking holes 84 facing each other.

The cover 8 is formed on the upper surface of the first support column 20a, the third support column 20c, and the fourth support column 20d of the holding member 2 and the upper surface of the second support column 20b. With the inner surface of the upper wall 81 in contact, the locking hole 84 and the locking projection 20f are locked.

In this locked state, the upper surfaces of the mounting table 20e and the second support pillar 20b and the inner surface of the upper wall 81 of the cover 8 are bonded and bonded with an adhesive.

As shown in FIG. 3, the drive main body 3 includes a piezoelectric element 31 that is an example of an electromechanical conversion element that expands and contracts in the axial direction, a drive shaft 32 that is connected to one end of the piezoelectric element 31, and a piezoelectric element 31. And a weight 33 connected to the other end.

The weight 33 is a member for causing displacement due to expansion and contraction of the piezoelectric element 31 mainly on the drive shaft 32 side, preferably only on the drive shaft 32 side. In this embodiment, the weight 33 is formed of a material having a high specific gravity such as tungsten or a tungsten alloy.

The weight 33 is a cylindrical shape formed so that the outer diameter protrudes from the outer periphery of the piezoelectric element 31 to the outer periphery over the entire periphery.

Note that the weight 33 may be omitted when the other end of the piezoelectric element 31 can be directly attached to the holding member 2 so that the same function as that of the weight 33 can be exhibited. .

The piezoelectric element 31 is an example of an electromechanical conversion element. This electromechanical transducer is an element that converts input electrical energy into mechanical energy that expands and contracts, that is, mechanical motion. For example, a piezoelectric that converts input electrical energy into mechanical elastic motion by the piezoelectric effect. Elements and the like. In the present embodiment, as described above, the piezoelectric element 31 is used as the electromechanical conversion element, and the piezoelectric element 31 includes, for example, a laminated body and a pair of external electrodes.

The laminate is formed by alternately laminating a plurality of thin film (layered) piezoelectric layers made of a piezoelectric material and a conductive thin film (layered) internal electrode layer. In the present embodiment, the laminate has a quadrangular prism shape, but is not limited to this, and may be, for example, a polygonal column shape or a cylindrical shape.

In the plurality of internal electrode layers, the plurality of anode layers among the plurality of internal electrode layers reach one side of the outer peripheral side surface in the multilayer body, and the plurality of cathode layers reach the other side of the outer peripheral side surface in the multilayer body. Are extended so that the front ends of the respective layers face each other on a pair of outer peripheral side surfaces facing each other. A pair of

external electrodes

31a and 31a supply the electric energy to the laminated body, and are formed on the pair of outer peripheral side surfaces of the laminated body by a sputtering method such as silver along the laminating direction. The plurality of internal electrodes are sequentially and alternately connected so as to be connected in parallel.

Examples of the piezoelectric material include lead zirconate titanate (so-called PZT), crystal, lithium niobate (LiNbO ₃ ), potassium tantalate niobate (K (Ta, Nb) O ₃ ), barium titanate (BaTiO ₃ ), Inorganic piezoelectric materials such as lithium tantalate (LiTaO ₃ ) and strontium titanate (SrTiO ₃ ).

The lower end surface of the piezoelectric element 31 is bonded to the upper end surface of the weight 33 with an adhesive such as an epoxy adhesive. In this embodiment, resinous beads having a diameter of about 5 μm are mixed in the epoxy adhesive in order to prevent a short circuit with the weight and stabilize the thickness of the adhesive layer.

The drive shaft 32 is formed of carbon fiber reinforced plastic (CFRP, carbon-fiber-reinforced plastic) in which carbon fibers are arranged in the axial direction and formed into a cylindrical shape with a resin. The drive shaft 32 of the present embodiment is formed so that the outer diameter protrudes from the outer periphery of the piezoelectric element 31 to the outer periphery over the entire periphery.

The lower end surface of the drive shaft 32 is bonded to the upper end surface of the piezoelectric element 31 with an adhesive. This adhesive is the same as the adhesive that bonds the piezoelectric element 31 and the weight 33.

The adhesive (fillet) protruding from the joint surface between the drive shaft 32 and the piezoelectric element 31 is formed on the piezoelectric element 31 side. As a result, the entire region of the drive shaft 32 (the entire region in the axial direction on the outer peripheral surface) can be used for sliding with the moving body 4, and a large stroke can be realized with the short drive shaft 32.

As shown in FIG. 13, the drive main body 3 configured in this manner is inserted into the drive main body holding portion 21 of the holding member 2 from the weight 33 side, and the drive main body holding portion 21 is bonded by an adhesive (not shown). The bottom surface and the weight 33 are bonded to each other, and the drive main body portion 3 is fixed in the drive main body holding portion 21. With this configuration, in this embodiment, the lower end surface (the other end) of the piezoelectric element 31 is indirectly attached to the holding member 2 via the weight 33.

When the weight 33 is inserted into the drive main body holding portion 21, the outer periphery of the drive shaft 32 comes into contact with the inner surface of the first support column 20a of the holding member 2, and the weight 33 is fixed to the holding member 2 in this state.

At this time, since the outer diameter of the drive shaft 32 is formed so as to protrude from the outer periphery of the piezoelectric element 31 to the outer periphery, the inner surface of the first support column 20a can be formed in a flat shape. . With this configuration, the drive shaft 32 can come into contact with the inner surface of the first support column 20a without the piezoelectric element 31 hitting. For example, when the outer periphery of the piezoelectric element 31 protrudes from the outer periphery of the drive shaft 32, the piezoelectric element 31 contacts the inner surface of the first support column 20 a of the holding member 2 in order to contact the outer periphery of the drive shaft 32. It is necessary to provide a step by recessing the protruding portion, and the molding of the holding member 2 becomes complicated and the productivity is lowered. However, as in this embodiment, by forming the inner surface of the first support column 20a flat, the holding member 2 can be easily formed, and productivity can be improved.

In this state, the axial direction of the drive shaft 32 coincides with the axial direction of the holding member 2.

Further, in the drive main body 3 held by the drive main body holding portion 21 of the holding member 2 in this way, a pair of external electrodes in the piezoelectric element 31 via the two first electrode connection springs 24a and the second electrode connection spring 24b. Each 31a is connected to the tip 22a of the first electrode terminal 22 and the tip 23a of the second electrode terminal 23 so as to be energized.

More specifically, as shown in FIG. 10, the first electrode connection spring 24a and the second electrode connection spring 24b have the same configuration, and are each a coil portion 25a that is plated with gold or platinum and wound with a wire. The torsion coil spring includes a first foot portion 25b and a second foot portion 25c that project radially outward from the coil portion 25a.

In the first electrode coupling spring 24a, the tip 22a of the first electrode terminal 22 is pushed into the coil portion 25a, the first foot portion 25b abuts on one external electrode 31a of the piezoelectric element 31, and the second foot portion 25c. Is locked to a spring locking portion 26 (see FIG. 9) provided in the holding member 2. In this state, a torsional force is accumulated in the coil portion 25a, and the first foot 25b presses the external electrode 31a of the piezoelectric element 31 by the torsional force.

In the second electrode connection spring 24b, the tip 23a of the second electrode terminal 23 is pushed into the coil portion 25a, the first foot portion 25b contacts the other external electrode 31a of the piezoelectric element 31, and the second foot portion 25c. Is locked to a spring locking portion 26 (see FIG. 9) provided in the holding member 2. In this state, a torsional force is accumulated in the coil portion 25a, and the first foot 25b presses the external electrode 31a of the piezoelectric element 31 by the torsional force.

In the present embodiment, the conductive adhesive 27 is applied from the contact portion between the first foot portion 25b of each of the first electrode connection spring 24a and the second electrode connection spring 24b and the external electrode 31a of the piezoelectric element 31 to the coil portion 25a. It arrange | positions so that it may interpose. Thereby, in addition to the first electrode connection spring 24a and the second electrode connection spring 24b, the conductive adhesive 27 can energize the external electrode 31a of the piezoelectric element 31, the first electrode terminal 22, and the second electrode terminal 23. Connected and connected more securely.

In this embodiment, the surface of the conductive adhesive 27 is covered with the reinforcing adhesive 28 to reinforce the adhesive strength of the conductive adhesive 27.

Next, the moving body 4 will be described. The moving body 4 is engaged with the drive shaft 32 with a predetermined frictional force, and slides along the axial direction of the drive shaft 32. As shown in FIG. 2, the moving body 4 of the present embodiment includes a metal cylindrical moving body main body 5 and a guide spring (metal plate body) 6 that is separate from the moving body main body 5. . In the present embodiment, the movable body main body 5 is made of, for example, stainless steel and has a thickness of 0.05 mm to 0.3 mm, and is formed by drawing. Stainless steel is a material that is inexpensive, has good moldability, good durability, and good driving performance among metal materials.

As shown in FIGS. 5 and 6, the movable body main body 5 includes a lens holding portion 54 on the inner peripheral side, and the lens holding portion 54 has a lens barrel as a moved body having one or a plurality of lens groups 71. 7 (see FIG. 13). An adhesive groove 72 is provided on the side surface of the lens barrel 7, and the lens barrel 7 is adhered to the lens holding portion 54 by filling the adhesive groove 72 with an adhesive 73 (see FIG. 13).

The movable body main body 5 includes a first sliding surface 51 that slides on the drive shaft 32 on a part of the outer peripheral surface. In the present embodiment, the first sliding surface 51 is formed in a flat plate shape with a predetermined width in the circumferential direction over the entire axial direction when molding the movable body main body 5. To form a flat surface. For this reason, when the movable body main body 5 slides on the drive shaft 32, the movable body main body 5 can slide while maintaining a certain posture without being inclined with respect to the drive shaft 32.

The mobile body 5 includes a first flange 52 formed at the lower end so as to protrude radially inward, and a second flange 53 formed at the upper end so as to protrude radially outward. Thus, the strength of the movable body main body 5 is increased.

The upper surface of the first flange 52 forms a lens barrel mounting portion 52a. When the lens barrel 7 is held by the lens holding portion 54 as shown in FIG. 13, the lens barrel mounting portion 52a has a lens barrel. 7 is arranged such that the axis of the movable body main body 5 and the optical axis of the lens group 71 of the lens barrel 7 are aligned without tilting each other.

As described above, since the movable body main body 5 is a metal tube, it has high durability and durability against wear, and since it is a thin metal tube, it is possible to increase the diameter of the lens 71 held inside. Become. Since the drive shaft 33 is driven in direct contact with the moving body main body 5, the moving body main body 5 is compared with a configuration in which a portion that frictionally engages the driving main body 3 is provided separately from a portion that holds the lens group 71. The diameter of the lens group 71 held inside can be increased.

In the present embodiment, the guide spring 6 is made of, for example, stainless steel and has a thickness of 0.1 mm to 0.3 mm. 7 and 8, the guide spring 6 includes an arc portion 61, a guide portion 62 formed on one end side of the arc portion 61, and a pressing piece 63 formed on the other end side of the arc portion 61. Is provided.

The arc portion 61 includes a rotation restricting portion 61a at a position separated from the guide portion 62 by approximately 180 ° in the circumferential direction. The rotation restricting portion 61a is for restricting the rotation of the movable body 4 around the axis of the drive shaft 32, and includes a restricting frame portion 61b and a hemispherical protrusion 61c formed on the restricting frame portion 61b. .

The restriction frame portion 61b is formed so that a part of the arc portion 61 protrudes radially outward in a rectangular shape.

The protrusion 61c is formed so as to protrude outward from both outer side surfaces of the restriction frame portion 61b. Further, the outer width V1 (see FIG. 9) between the protrusions 61c is set to be slightly narrower than the inner width V2 (see FIG. 9) of the restricting portion receiving groove 29 of the holding member 2. In FIG. 9, for the convenience of drawing, the outer width V <b> 1 between the protrusions 61 c and the inner width V <b> 2 of the restricting portion receiving groove 29 are represented by the same width.

In the present embodiment, the arc portion 61 includes a narrow portion 61d having a narrower width than the other portions between one end (guide portion 62) and the rotation restricting portion 61a.

The guide portion 62 is formed by bending a part of one end side of the arc portion 61 outward in the radial direction of the arc portion 61, and a second sliding surface 62 a that slides the drive shaft 32 is formed on one surface thereof. Prepare.

The pressing piece 63 is formed so as to extend linearly from the other end of the arc portion 61 through a stepped portion, and includes a pressing portion 63a that presses the drive shaft 32 at a tip portion thereof. The pressing part 63a of the present embodiment is formed narrower than the first sliding surface 51 and the second sliding surface 62a.

The guide spring 6 and the movable body main body 5 are fixedly connected by welding.

More specifically, as shown in FIG. 11, the guide spring 6 and the movable body main body 5 are adjacent to each other in the first sliding surface 51 of the movable body main body 5 and the second sliding surface 62a of the guide spring 6. The guide spring 6 is wound around the outer periphery of the movable body main body 5.

In this state, both of the first fixing portion 64a and the first fixing portion 64a spaced apart from the guide portion 62 in the arc portion 61 of the guide spring 6 by a predetermined distance, for example, as indicated by x in FIG. Further, resistance welding (spot welding) is performed at four positions spaced apart from each other between the second fixing portion 64b and the third fixing portion 64c on both sides of the rotation restricting portion 61a and the fourth fixing portion 64d in the vicinity of the boundary between the pressing piece 63. ) And laser welding or the like.

By this fixing, an elastic portion 65 that can be elastically deformed in the radial direction of the guide spring 6 is formed between the guide portion 62 and the first fixing portion 64a in the arc portion 61 of the guide spring 6.

In this embodiment, the elastic portion 65 is formed so that the radius of curvature of the inner peripheral surface is smaller than the radius of curvature of the outer peripheral surface of the movable body main body 5 before being fixed to the movable body main body 5. Then, the inner periphery of the elastic portion 65 moves against the elasticity while the guide spring 6 is wound around the outer periphery of the movable body main body 5 and the first fixed portion 64a is fixed to the movable body main body 5 by welding. It is larger than the state before the radius of curvature is fixed by being pushed over the outer periphery of the body main body 5.

Therefore, the elastic part 65 urges the guide part 62 (second sliding surface 62a) to the inner side in the radial direction (Z direction shown in FIG. 11) of the movable body main body 5 with the elastic force corresponding to the spread. It is in a state.

In the present embodiment, at the time of the above welding, as shown in FIG. 12, the positioning jig 11 that holds the rotation restricting portion 61a and the second sliding surface attitude adjustment jig 12 that holds the guide portion 62 are used. Welding is performed after the positions of the main body 5 and the guide spring 6 and the attitude of the second sliding surface are determined. At this time, for example, when the posture of the second sliding surface is set, the posture of the second sliding surface is easily set by the narrow portion 61 d of the arc portion 61.

In a state fixed by this welding, the first sliding surface 51 and the second sliding surface 62a are substantially perpendicular to each other, and the first and second sliding

surfaces

51, 62a form an L shape together. is doing.

In this way, the movable body main body 5 and the guide spring 6 are made of a metal such as stainless steel, and are joined by welding, so that the movable body main body 5 and the guide spring 6 can be firmly fixed. Since it can be fixed instantly, the manufacturing tact time can be greatly reduced.

As shown in FIG. 9, the movable body 4 in which the movable body main body 5 and the guide spring 6 are connected has the rotation restricting portion 61 a inserted in the restricting portion receiving groove 29 of the holding member 2, and the drive shaft 32. Is arranged so as to be surrounded by the first sliding surface 51, the second sliding surface 62a, and the pressing portion 63a.

Accordingly, the first sliding surface 51 is pressed against the outer periphery of the drive shaft 32 by the elastic force of the pressing piece 63, and the second sliding surface 62 a contacts the first sliding surface 51 on the outer periphery of the driving shaft 32. The movable body 4 is frictionally engaged with the drive shaft 32 by being pressed to a position that is spaced a predetermined distance in the circumferential direction.

In this state, the pressing piece 63 is in a state extending from the second corner portion 2b of the holding member 2 to the first corner portion 2a. The first sliding surface 51 is perpendicular to a line P connecting the center O1 of the holding member 2 and the axis O2 of the drive shaft 32 when viewed from the upper side (one side) of the drive shaft 32 in the axial direction. Further, the second sliding surface 62a is in contact with the drive shaft 32 while being parallel to the line P and facing the second corner portion 2b between the fourth corner portion 2d and the drive shaft 32. It touches.

In the driving device 1 configured as described above, for example, as shown in FIG. 13, the lens barrel (imaging optical system) 7 is held by the lens holding portion 54 of the moving body 4, and the IR cut is formed on the lower surface side of the holding member 2. A sensor substrate 103 a having a filter 102 and an image sensor 103 is attached. Thereby, the imaging device 100 is formed.

The image sensor 103 is an image of each component of R (red), G (green), and B (blue) according to the amount of light in an optical image of an object (subject) imaged by an imaging optical system (not shown) as a whole. It is an element that photoelectrically converts a signal and outputs it to a predetermined image processing circuit (not shown). The image sensor 103 is, for example, a CCD image sensor, a CMOS image sensor, or the like.

The imaging optical system includes one or a plurality of lens groups (optical elements) including a lens group 71, and forms an optical image of an object on the light receiving surface of the imaging element 103. The lens group 71 is an optical element that moves along the optical axis among the one or more optical elements in such an imaging optical system. The lens group 71 may be a single lens or may include a plurality of lenses. The lens group 71 may be, for example, an optical system that moves along the optical axis to perform focusing (focusing), and, for example, an optical that moves along the optical axis to perform zooming (magnification). It may be a system. The optical image of the object is guided by the imaging optical system including the lens group 71 to the light receiving surface of the imaging element 103 along the optical axis, and the optical image of the object is captured by the imaging element 103. The

For example, the external connection terminal 22b of the first electrode terminal 22 and the external connection terminal 23b (see FIG. 1 and the like) of the second electrode terminal 23 are arranged on the circuit board of the mobile phone and installed in the casing of the mobile phone. .

When electric power (drive signal) is supplied from an unillustrated drive circuit to the external connection terminal 22b of the first electrode terminal 22 and the external connection terminal 23b of the second electrode terminal 23, the piezoelectric element 31 of the drive device 3 is moved in the axial direction. The drive shaft 32 reciprocates due to the expansion and contraction, and the movable body 4 moves in the axial direction (optical axis direction) of the drive shaft 32 due to the reciprocation.

More specifically, when a rectangular wave having a predetermined duty ratio is applied to the piezoelectric element 31 as a drive signal, the displacement of the piezoelectric element 31 becomes a triangular wave shape, and when the rectangular wave has a duty ratio that is changed by changing the duty ratio of the rectangular wave. ) And a triangular wave-like expansion / contraction motion with different inclinations when descending (when contracting). The drive mechanism of the drive main body 3 utilizes this.

For example, when the drive shaft 32 is slowly extended, the moving body 4 that is frictionally engaged with the drive shaft 32 also moves in accordance with the extension, and the drive is instantaneously performed to exceed the frictionally engaged friction force. When the shaft 32 is contracted, the moving body 4 is left as it is at the position of the movement destination. By repeatedly expanding and contracting the drive shaft 32 in the axial direction, the moving body 4 slides in the axial direction of the drive shaft 32.

When the moving body 4 slides on the drive shaft 32, the first sliding surface 51 and the second sliding surface 62a slide while being pressed against the driving shaft 32. It can move without changing its posture.

Since the pressing portion 63a is formed to be narrower than the first sliding surface 51 and the second sliding surface 62a, for example, even when the pressing piece 63 is twisted, the drive shaft 32 is securely moved to the first sliding surface. The moving surface 51 and the second sliding surface 62a can be brought into line contact with each other, and the moving body 4 can move more reliably without changing its posture.

When the moving body 4 tries to rotate around the axis of the drive shaft 32, any one of the protrusions 61c of the rotation restricting portion 61a comes into contact with the inner wall of the restricting portion receiving groove 29, so that the rotation of the moving body 4 is restricted. Is done. When the moving body 4 slides on the drive shaft 32 from the state in which the protrusion 61c is in contact with the inner wall of the restricting portion receiving groove 29, the protrusion 61c is formed in a hemispherical shape and makes point contact with the inner wall of the restricting portion receiving groove 29. Therefore, the movable body 4 can slide on the drive shaft 32 with almost no resistance due to the contact.

For example, an impact force due to dropping is applied to a mobile phone equipped with the drive device 1, and as a result of this impact force, a fourth corner angle is applied to the moving body 4 frictionally engaged with the drive shaft 32 as shown in FIG. When a force in the second direction (W2 direction) from the portion 2d toward the second corner portion 2b is applied, the driving device 1 operates as follows.

When the second sliding surface 62a in contact with the drive shaft 32 receives a reaction force from the drive shaft 32 and the reaction force becomes larger than the urging force of the elastic portion 65 applied to the second sliding surface 62a, FIG. As shown in FIG. 4, the elastic portion 65 is elastically deformed, and the second sliding surface 62a moves outward in the radial direction of the movable body main body portion 5.

On the other hand, the movable body main body 5 moves in the second direction and comes into contact with the second support pillar 20b, and the rotation restricting portion 61a of the movable body main body 5 is provided in the restricting portion receiving groove 29 of the third support pillar 20c. It abuts against the inner wall, and as a result, movement in the second direction is stopped. Therefore, the force in the second direction applied to the moving body 4 can be received in a distributed manner by the drive shaft 32, the second support column 20b, and the third support column 20b, and the drive shaft 32 can be received by the urging force of the elastic portion 65. Is not received from the second sliding surface 62a.

Therefore, in the drive device 1 of the present embodiment, the drive shaft 32 can be prevented from being tilted or displaced from the holding member 2.

On the other hand, as shown in FIG. 9, when a force in the first direction (W1 direction) from the second corner 2b opposite to the second direction toward the fourth corner 2d is applied to the moving body 4, The pressing piece 63 (not shown) is deformed, and the second sliding surface 62a moves in the first direction together with the movable body main body 5. During the movement, the second sliding surface 62a moves away from the drive shaft 32, and no force is transmitted from the second sliding surface 62a to the drive shaft 32.

The mobile body 5 moves in the first direction and contacts the fourth support column 20d, and the rotation restricting portion 61a contacts the inner wall of the restricting portion receiving groove 29 of the third support column 20c. Movement in the direction is stopped.

When a force is applied to the moving body 4 in a direction perpendicular to the second direction from the first corner 2a toward the third corner 2c, the second sliding surface 62a and the first sliding No force is transmitted from the surface 51 to the drive shaft 32. In this case, the movable body main body 5 moves in the direction from the first corner 2a toward the third corner 2c, and the rotation restricting portion 61a is formed on the inner wall of the restricting portion receiving groove 29 of the third support pillar 20c. As a result, the movement in the same direction is stopped.

Conversely, when a force is applied to the moving body 4 in the direction perpendicular to the second direction from the third corner 2c toward the first corner 2a, the mobile body 4 is driven from the first sliding surface 51. A force is transmitted to the shaft 32. However, in this embodiment, since the drive shaft 32 is received by the first support column 20a of the holding member 2 from the opposite side to the first sliding surface 51, the force from the first sliding surface 51 is the driving shaft. 32 to the first support column 20a. Thereby, it is possible to prevent the drive shaft 32 from being inclined or being displaced from the holding member 2. In this case, since the first sliding surface 51 is constituted by a part of the movable body main body 5, the movement is stopped by the first support pillar 20 a via the drive shaft 32.

As described above, in the present embodiment, as a result of at least one of the first and second sliding

surfaces

51, 62a being configured to be movable with respect to the movable body main body 5, for example, when an impact force due to dropping is applied, Regardless of the presence or absence of the movement limiting portion (second support pillar 20b in the present embodiment), the acceleration of the movable body main body 5 can be reduced and the impact force transmitted to the drive shaft 32 can be reduced.

FIG. 15 is a diagram for explaining a moving body of another mode in the driving apparatus shown in FIG. FIG. 15A is a plan view in which a cover of a driving apparatus incorporating a moving body of another embodiment is omitted, and FIG. 15B is a direction in which the moving body of FIG. 15A is directed from the fourth corner to the second corner. It is a top view at the time of receiving the force of. In FIG. 15, the pressing piece 63 is not shown. In the above embodiment, the moving body 4 is configured such that only the second sliding surface 62a moves relative to the moving body main body 5. However, the moving body 4 is not limited to this configuration and can be changed as appropriate. For example, as shown in FIG. 15, the moving body 104 may be configured such that both the first sliding surface 161 and the second sliding surface 162 move relative to the moving body main body 105.

More specifically, the moving body 104 includes a moving body main body portion 105, a sliding portion 160 separate from the moving body main body portion 105, and an elastic portion 164 that supports the sliding portion 160.

The sliding portion 160 includes a concave portion formed so as to be recessed in a dogleg shape on the distal end side, and a first sliding surface 161 and a second sliding surface 162 are formed in the concave portion.

The sliding part 160 includes a main body sliding part 160a that slides on the movable body main body part 105 on the side surface.

The elastic portion 164 is formed of a plate-like elastic member, and has a base end connected to the movable body main body 105 and a distal end connected to the sliding portion 160 to support the sliding portion 160.

When the moving body 104 receives the force in the second direction (W2 direction), the first sliding surface 161 and the second sliding surface 162 that are in contact with the drive shaft 32 receive a reaction force from the drive shaft 32. As shown in FIG. 15B, the elastic part 164 is elastically deformed, and the main body sliding part 160 b moves in the circumferential direction of the movable body main body part 5.

Therefore, in this case as well, the force in the second direction applied to the moving body 104 can be received by the drive shaft 32, the second support column 20b, and the third support column 20c in a distributed manner. A force larger than the force by which 164 elastically deforms is not received from the sliding portion 160.

Therefore, in this case as well, it is possible to prevent the drive shaft 32 from being inclined or displaced from the holding member 2.

FIG. 16 is a diagram for explaining a moving body of still another aspect in the driving apparatus shown in FIG. In FIG. 16, the pressing piece 63 is not shown. In the said embodiment, although the elastic part was formed from the plate-shaped thing, it can change suitably not only in the thing of this form. For example, as shown in FIG. 16, the elastic part may be composed of a coil spring 264.

More specifically, the moving body 204 includes a moving body main body 205, a sliding piece 260, and a coil spring 264 as an elastic portion that biases the sliding piece 260.

The movable body main body 205 is made of synthetic resin, and a metal plate 261a is fixedly attached to the outer periphery thereof. The outer surface of the metal plate 261a forms a first sliding surface 261.

The moving body main body 205 includes a housing recess 252 that houses the sliding piece 260 and the coil spring 264. The storage recess 252 includes an opening 252a and a sliding piece receiving part 252b formed in the opening 252a.

The sliding piece 260 includes a shaft portion 260a and a head portion 260b formed on the tip side of the shaft portion 260a. The head portion 260b is formed larger in diameter than the shaft portion 260a, and includes a second sliding surface 262 at a distal end surface thereof and a coil spring contact portion 260c at a proximal end surface thereof. And the sliding piece 260 is accommodated in the accommodation recessed part 252 so that a movement is possible.

The coil spring 264 has one end in contact with the back end surface 252 c of the storage recess 252 and the other end in contact with the coil spring contact portion 260 c of the head 260 b of the sliding piece 260 in the storage recess 252.

Thus, the sliding piece 260 is urged in the second direction (W2 direction) from the fourth corner 2d of the holding member 2 toward the second corner 2b by the urging force of the coil spring 264, and the head 260b The front end surface is pressed against the sliding piece receiving portion 252b of the storage recess 252.

Therefore, the second sliding surface 262 of the sliding piece 260 is maintained in a state of being biased by the biasing force of the coil spring 264.

When the moving body 204 receives the force in the second direction and the second sliding surface 162 in contact with the drive shaft 32 receives a reaction force greater than the biasing force of the coil spring 264 from the drive shaft 32, the coil spring 264 is moved. Shrink.

Therefore, in this case as well, the force in the second direction applied to the moving body 204 can be received by the drive shaft 32, the second support column 20b, and the third support column 20c in a distributed manner, and the drive shaft 32 can receive the coil spring 264. A force larger than the urging force is not received from the second sliding surface 162.

In the above embodiment, the movable body main body 5 has the rotation restricting portion 61a abutting against the inner wall of the restricting portion receiving groove 29 of the third support pillar 20c when moving in the first or second direction. Not limited to this form, it can be changed as appropriate. For example, the movable body main body 5 does not have the rotation restricting portion 61a, and is received by the second support pillar 20b when the movable body main body 5 moves in the second direction. It may be configured to be received by the fourth support pillar 20d during the movement.

In the above embodiment, the movement restricting portion is provided on the holding member 2 of the apparatus main body. However, the movement restricting portion is not limited to this configuration. For example, the movement restricting portion may be provided on the cover 8 of the apparatus main body 2. Can be changed as appropriate. Further, although the piezoelectric element 31 is fixed to the holding member 2 via the weight 33, the side surface of the piezoelectric element 31 may be fixed to the holding member 2.

This specification discloses various modes of technology as described above, and the main technologies are summarized below.

A driving apparatus according to an aspect includes an electromechanical conversion element that converts electrical energy into mechanical energy that expands and contracts, and a drive shaft that is fixed to one end side in the expansion and contraction direction of the electromechanical conversion element and that transmits the mechanical energy. A movable body that is engaged with the drive shaft with a predetermined frictional force and is slidable along the axial direction of the drive shaft, and an apparatus main body that directly or indirectly holds the electromechanical conversion element. Prepare. The movable body includes a movable body main body to which a driven body is attached, first and second sliding surfaces that slide on the drive shaft, and the drive on the first sliding surface and the second sliding surface. A pressing member that presses the shaft, and at least one of the first and second sliding surfaces is configured to be movable with respect to the movable body main body.

In such a drive device, since at least one of the first and second sliding surfaces is configured to be movable with respect to the moving body main body, even if the moving body main body moves due to an external force, the first and second sliding surfaces are arranged. At least one of the two sliding surfaces can be configured not to move together with the movable body main body. Thereby, for example, even when a mobile phone equipped with this drive device is subjected to an impact force due to a drop and an external force is applied to the moving body frictionally engaged with the drive shaft, the first and second sliding surfaces The moving body main body moves relative to at least one of them, reduces the acceleration of the moving body main body, and can reduce the impact force transmitted to the drive shaft.

In another aspect, in the above-described drive device, the movable body main body is movable in the radial direction of the drive shaft in association with relative movement with at least one of the first and second sliding surfaces. The apparatus main body includes a movement restricting section that restricts movement of the movable body main body relative to the apparatus main body that occurs in association with relative movement between at least one of the first and second sliding surfaces and the movable body main body. Prepare. Preferably, the movement restricting portion is disposed on a radially outer side of the movable body main body portion of the apparatus main body so as to be able to stop the movable body main body portion when the movable body main body portion is moved in the radial direction. Provide pillars.

In such a drive device, the movable body main body can restrict the movement of the drive shaft in the radial direction by the movement restricting portion. Therefore, for example, when a mobile phone equipped with this drive device is dropped on the ground and an impact force applied to the mobile phone is applied in the radial direction of the drive shaft of the mobile body main body, the impact force is distributed to the movement restricting portion. Therefore, the force applied to the drive shaft and the electromechanical transducer can be reduced, and the force applied to the movable body main body can be suppressed from being transmitted to the drive shaft.

In another aspect, in the above-described driving device, the movable body further includes a coupling member that couples at least one of the first and second sliding surfaces and the movable body main body, and the coupling The member includes an elastic portion between at least one of the first and second sliding surfaces and the movable body main body.

In such a drive device, when an external force is applied to at least one of the first and second sliding surfaces, the elastic portion accumulates the external force, and when the external force is removed, the elastic portion can restore the original state. Therefore, at least one of the first and second sliding surfaces and the movable body main body can be formed so as to be easily movable, and an increase in size can be suppressed.

In another aspect, in the above-described driving device, at least one of the first and second sliding surfaces is in a biased state in which a biasing force is applied by the elastic portion, and the first and second sliding surfaces When a force larger than the urging force is applied to at least one of the surfaces, the movable body main body is configured to move. Preferably, the connecting member is formed of a plate-like piece having elasticity, and the base end side of the moving member is pressed against the outer periphery of the moving body main body by a predetermined urging force from outside in the radial direction. Connected to the main body, at least one of the first and second sliding surfaces is held on the distal end side of the connecting member.

In such a drive device, at least one of the first and second sliding surfaces can be made to not move relative to the movable body main body unless receiving a force greater than the urging force applied by the elastic portion. . As a result, the first and second sliding surfaces can slide in a stable state while maintaining a constant posture of the drive shaft at all times.

In another aspect, in the above-described driving device, the movable body main body portion is made of a metal cylinder, and the first sliding surface is formed on a part of the outer peripheral surface of the movable body main body portion. The second sliding surface is disposed at one end of the connecting member, and the other end of the connecting member is connected to the movable body main body by welding.

In such a drive device, it is not necessary to form the first sliding surface separately from the movable body main body, and it can be easily manufactured. Since the movable body main body is made of a metal cylinder, the strength is higher than that of a resin, and the radial thickness can be made thinner than that of a resin. Thereby, for example, when holding a large-aperture lens group on the inner peripheral side, the outer diameter can be suppressed. On the other hand, when a small-aperture lens group is held on the inner peripheral side, the outer diameter can be reduced. Therefore, it is possible to reduce the size of the movable body main body, and thus the entire drive device. Moreover, the moving body main body can be thinned and lightened, and for example, the load when receiving an impact force due to dropping can be reduced.

Further, the second sliding surface can be formed by connecting the other end of the connecting member to the movable body main body by welding, and the second sliding surface can be easily manufactured.

In another aspect, in the above-described driving device, the device main body includes a holding member that holds the electromechanical conversion element, and a cover that covers the holding member, and the holding member includes the driving shaft. The driving shaft is disposed at a first corner of the holding member, and at least one of the first and second sliding surfaces is the holding member. When receiving a force in the first direction from the second corner adjacent to the first corner of the member toward the fourth corner opposite to the second corner, the force is While not applied to the drive shaft, when receiving a force in the second direction from the fourth corner toward the second corner, a part of the force is applied to the drive shaft and the moving body It is arranged to move with respect to the main body, and the movement restriction unit is It is disposed in said second corner in the support member.

In such a drive device, for example, when a force in the first direction is applied to the movable body main body by an impact force received by the mobile phone, the first drive shaft is connected to the drive shaft from at least one of the first and second sliding surfaces. Almost no direction force is applied. On the other hand, when a force in the second direction opposite to the first direction is applied to at least one of the first and second sliding surfaces, at least one of the first and second sliding surfaces is the movable body main body. Can move against. As a result, the force in the second direction applied to the drive shaft from at least one of the first and second sliding surfaces is reduced. In addition, the movable body main body moves with respect to the holding member by the force in the second direction. However, since the movement restricting portion is disposed at the second corner of the holding member, the movable body main body can be stopped. The movement of the mobile body main body can be restricted.

Therefore, the movement restricting portion only needs to be arranged at the second corner portion of the holding member, thereby reducing the force applied to the drive shaft by the impact force received by the mobile phone.

In addition, an imaging apparatus according to another aspect includes any one of the above-described driving apparatuses, an imaging element that converts an optical image into an electrical signal, and one or more optical elements. An imaging optical system that forms an optical image on a light receiving surface of the imaging element, and the optical element that moves in the optical axis direction of the one or more optical elements in the imaging optical system is the drive It is attached to the moving body of the apparatus.

Since such an imaging device includes any one of the above-described driving devices, at least one of the first and second sliding surfaces is movable body main body even when the movable body main body is moved by an external force. You can make it not move with. Thereby, for example, even when a mobile phone equipped with this drive device is subjected to an impact force due to a drop and an external force is applied to the moving body frictionally engaged with the drive shaft, the first and second sliding surfaces The moving body main body moves relative to at least one of them, reduces the acceleration of the moving body main body, and can reduce the impact force transmitted to the drive shaft.

This application is based on Japanese Patent Application No. 2012-231654 filed on October 19, 2012, the contents of which are included in this application.

In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

According to the present invention, it is possible to provide a drive device suitably used for an imaging device that can be mounted on, for example, a mobile phone, and an imaging device using the driving device.

Claims

An electromechanical transducer that converts electrical energy into expanding and contracting mechanical energy;
A drive shaft that is fixed to one end side in the expansion / contraction direction of the electromechanical transducer and that transmits the mechanical energy;
A movable body that is engaged with the drive shaft with a predetermined frictional force and is slidable along the axial direction of the drive shaft;
An apparatus main body directly or indirectly holding the electromechanical transducer, and
The movable body includes a movable body main body to which a driven body is attached, first and second sliding surfaces that slide on the drive shaft, and the drive on the first sliding surface and the second sliding surface. A pressing member that presses the shaft,
At least one of the first and second sliding surfaces is configured to be movable with respect to the movable body main body.
Drive device.
The movable body main body is movable in the radial direction of the drive shaft in association with relative movement with at least one of the first and second sliding surfaces.
The apparatus main body includes a movement restricting unit that restricts movement of the movable body main body with respect to the apparatus main body caused by relative movement between at least one of the first and second sliding surfaces and the movable body main body. ,
The drive device according to claim 1.
The movable body further includes a connecting member that connects at least one of the first and second sliding surfaces and the movable body main body,
The connecting member includes an elastic portion between at least one of the first and second sliding surfaces and the movable body main body.
The drive device according to claim 1 or 2.
At least one of the first and second sliding surfaces is in a biased state in which a biasing force is applied by the elastic portion, and a force larger than the biasing force is applied to at least one of the first and second sliding surfaces. Is configured to be movable with respect to the movable body main body when receiving
The drive device according to claim 3.
The movable body main body is made of a metal cylinder,
The first sliding surface is formed on a part of the outer peripheral surface of the movable body main body,
The second sliding surface is disposed at one end of the connecting member,
The other end of the connecting member is connected to the movable body main body by welding,
The drive device according to claim 3 or 4.
The apparatus main body includes a holding member that holds the electromechanical conversion element, and a cover that covers the holding member,
The holding member has a substantially rectangular shape when viewed from one side in the axial direction of the drive shaft,
The drive shaft is disposed at a first corner of the holding member;
At least one of the first and second sliding surfaces is a fourth corner that is a diagonal of the second corner from a second corner adjacent to the first corner of the holding member. The first direction force is not applied to the drive shaft when receiving the first direction force toward the second direction, while the second direction force from the fourth corner portion to the second corner portion is not applied. When received, a part of the force in the second direction is applied to the drive shaft, and is arranged so as to move relative to the movable body main body,
The movement restricting portion is disposed at the second corner portion of the holding member.
The drive device according to any one of claims 2 to 5.
A driving device according to any one of claims 1 to 6,
An image sensor that converts an optical image into an electrical signal;
An imaging optical system that includes one or a plurality of optical elements, and that forms an optical image of an object on a light receiving surface of the imaging element;
The optical element that moves in the optical axis direction among the one or more optical elements in the imaging optical system is attached to the movable body main body of the driving device.
Imaging device.