JP2007159244A - Drive unit and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive unit that drives a driven body and enlarges it in dimension while achieving downsizing. <P>SOLUTION: In the drive unit 30 of a lens unit 1, since a protrusion 202 is displaced along a direction that intersects with an optical axis O in a gear lever 60 when the gear lever 60 is turned, the protrusion 202 is linearly driven in a prescribed direction along the optical axis O in conjunction with the turn of the gear lever 60. When rotational movement is received by a cam and converted into linear movement, the stroke of a lens 20 having the protrusion 202 cannot be enlarged unless a large-sized cam is employed, but the length of a string that connects both ends of an arc being a turning locus of the gear lever 60, can be used as a stroke length, thereby largely securing the stroke of the lens 20 while achieving the downsizing. An energy loss caused by friction is small compared with the case wherein the protrusion 202 is friction-coupled to a driving shaft that is moved by a vibrating body 40, thus improving driving efficiency. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a driving device that drives a driven body by a vibrating body using a piezoelectric element, and an electronic apparatus such as a camera, a digital camera, a video camera, a microscope, a binocular, and a projector including the driving device.

2. Description of the Related Art Conventionally, a drive device that uses an electromagnetic motor (see, for example, Patent Document 1) is generally used as a drive device that drives movable parts constituting various electronic devices.
In the lens driving device disclosed in Patent Document 1, a plurality of lens groups as driven bodies arranged in a lens unit and an electromagnetic motor provided outside the lens unit are connected via a gear or a cam ring. Yes. Then, gears and cam rings are rotated in conjunction with the electromagnetic motor, and zooming and focus adjustment are performed as each lens group advances and retreats along the optical axis along with the rotation.

On the other hand, a driving device (for example, see Patent Documents 2 to 4) that drives a lens by deformation of a piezoelectric element has been proposed.
The driving apparatus in Patent Documents 2 to 4 includes a lens holding frame as a driven body, a driving shaft frictionally coupled to the lens holding frame, and a piezoelectric element provided along the driving shaft. Has been. In this driving device, by applying a voltage having a predetermined waveform to the piezoelectric element, the piezoelectric element expands and contracts in the direction along the driving axis to move the driving axis, and the lens holding frame frictionally coupled to the driving axis is provided. Driven. Here, the voltage applied to the piezoelectric element has a pulse waveform that is gently displaced in the driving direction (forward or backward) and rapidly displaced in the direction opposite to the driving direction. In other words, the driven body moves due to the frictional force with the drive shaft in the driving direction, and the inertial force of the driven body does not move above the frictional force in the reverse direction. Will be driven.

JP 10-161001 A (page 3-4) JP-A-7-274546 (Page 3-4) JP-A-8-66068 (page 3-4) JP-A-4-69070 (page 3-5)

However, in the drive device using the electromagnetic motor as in Patent Document 1, it is necessary to provide a large electromagnetic motor outside the lens unit, so that the lens unit becomes large.
Also in the driving devices of Patent Documents 2 to 4, since the expansion and contraction of the piezoelectric element is directly transmitted to the drive shaft, it is necessary to cause a large expansion and contraction displacement in the piezoelectric element in order to rapidly advance and retract the drive shaft. There is a problem that the size of the piezoelectric element in the expansion / contraction direction increases, and the size of the entire lens unit increases.
Further, in the structure as disclosed in Patent Documents 2 to 4, in a drive device that is required to be downsized, if the length of the piezoelectric element is ensured to be large, the drive shaft of the lens unit is correspondingly shortened, and the drive distance that allows the lens to advance and retract. (Stroke) is difficult to secure. Thereby, performance such as zoom and focus adjustment can be limited.

  In view of such a problem, an object of the present invention is to provide a driving device capable of increasing a size that can be driven by a driven body while reducing the size, and an electronic apparatus including the driving device.

  The drive device of the present invention meshes with a vibrating body that vibrates due to deformation of a piezoelectric element, a rotor that is rotated by contacting the vibrating body, a first gear portion that is linked to the rotor, and the first gear portion. The second gear part is interlocked with the second gear part and overlaps with the vibrating body, and the driven body is held movably along a direction crossing a predetermined direction along the arc chord that is the rotation trajectory. And a lever.

According to this invention, when the lever is rotated via the first and second gear portions by the rotation of the rotor, the driven body is displaced along the direction intersecting the string in the lever. In conjunction with this, the driven body can be linearly driven in a predetermined direction along the string.
Here, in addition to the vibrating body, the present invention includes a member having a simple configuration such as a rotor, a gear unit, and a lever, and directly transmits the vibration of the vibrating body to the rotor and the lever that is linked to the rotor. In addition, it is not necessary to provide a complicated structure of a conventionally used electromagnetic motor or a gear associated therewith, and the structure can be simplified and the drive device can be miniaturized.
In addition, instead of directly transmitting the vibration of the vibrating body to the driven body, the driven body is driven via the rotor, each gear unit, and the lever, so that the position where the vibrating body is disposed extends in the driving direction of the driven body. Since it is not limited above, it becomes possible to provide a vibrating body in the position which remove | deviated from the driving direction extension of a to-be-driven body. Thereby, the dimension of the drive device in the drive direction of the driven body can be reduced.
In addition, the arrangement of the parts can be saved even at the point where the lever overlaps the vibrating body, and the drive device can be made smaller.

In addition, when rotating motion is received by a cam and converted to linear drive, it is difficult to increase the driveable distance (stroke) unless a large cam is used. In the present invention, since the stroke length corresponding to the length of the string connecting both ends of the arc that is the rotation trajectory of the lever can be obtained, a large stroke of the driven body can be secured while achieving downsizing.
In addition, since the driven body is driven through the rotor and the lever in this way, energy loss due to friction is small compared to the case where the driven body is frictionally coupled to the drive shaft that is moved by the vibrating body, Drive efficiency can be improved.

  In the drive device according to the aspect of the invention, it is preferable that the vibration body is configured to be able to switch a vibration locus, and the rotor is rotatable in a forward direction and a reverse direction in which the vibration locus is different from each other.

  According to this invention, the driven body is advanced (or retracted) by rotating the rotor in the forward direction according to the vibration locus of the vibrating body, and the driven body is rotated by rotating the rotor in the reverse direction. Can be moved backward (or moved forward). That is, since the driven body can be driven in both the forward and backward directions by one vibrating body, it is unnecessary to prepare two vibrating bodies for advancing and retreating the driven body.

  In the drive device according to the aspect of the invention, it is preferable that the vibrating body and the rotor are in contact with each other in a state where one is biased toward the other.

  According to the present invention, since an appropriate frictional force is generated between the vibrating body and the rotor due to the biasing, rattling between the vibrating body and the rotor can be prevented. In addition, due to an appropriate frictional force between the vibrating body and the rotor, slippage hardly occurs when the vibrating body sends the rotor due to expansion and contraction of the piezoelectric element, and driving efficiency can be improved.

  In the drive device according to the aspect of the invention, it is preferable that the position of the vibrating body is fixed, and the rotor is provided with a biasing unit that biases the rotor toward the vibrating body.

According to the present invention, since the position of the vibrating body can be fixed when biasing one of the vibrating body and the rotor to the other, the vibration of the vibrating body is stabilized. In addition, since the position of the vibrating body is fixed, the structure for preventing disconnection can be made unnecessary or simplified, so that wiring to the vibrating body can be facilitated.
In addition, the first gear portion provided on the rotor is also biased toward the second gear portion by the biasing means provided on the rotor, compared to the case where the biasing means is provided on the vibrating body, The meshing between the first gear portion provided on the rotor and the second gear portion provided on the lever is stabilized. For this reason, the driven body can be stably moved by the lever that rotates integrally with the second gear.

  In the driving apparatus according to the present invention, it is preferable that the lever is formed with a slit extending along a radial direction in the rotation thereof, and the driven body has a protrusion inserted into the slit.

According to the present invention, the formation of the slit makes it possible to easily realize that the driven body can be moved in the direction intersecting the string and held by the lever, and the driven body is guided along the slit. Therefore, rattling when the driven body moves along the direction of the string can be prevented.
If the driven body is held in a state where the both sides of the slit are thin and elastic in the direction of the string, the driven body is displaced along the direction intersecting the string in the lever. The overall movement can prevent rattling when moving along the direction of the string.

  In the drive device according to the present invention, the second gear portion includes a first member and a second member that are overlapped with each other and have substantially the same shape, and the first member and the second member. One of the members is biased in the circumferential direction of the rotation shaft with respect to the other, and the teeth of the first gear portion are between the tooth row of the first member and the tooth row of the second member. It is preferable to be sandwiched.

According to this invention, the first and second members of the second gear portion can follow the movement of the teeth of the first gear portion, and the backlash between the first and second gear portions can be reduced. The backlash of the second gear portion can be prevented, and the operation of the lever is stabilized. Therefore, the driven body can be moved to a desired position, and noise reduction and driving efficiency can be improved.
Here, the second gear portion and the lever are integrally formed, and it is also possible to form the first member and the second member having the second gear portion and the lever, thereby reducing the number of parts, Cost can be reduced. The first and second members can be manufactured, for example, by stamping a metal plate.

  In the drive device according to the aspect of the invention, it is preferable that the vibrating body has a rectangular shape, and the lever extends from the rotating shaft so as to intersect the longitudinal direction of the vibrating body.

  According to the present invention, the circumferential direction when the lever rotates follows the longitudinal direction of the vibrating body, and the lever rotating area can be increased in a range where the lever overlaps with the vibrating body. Therefore, the stroke length can be increased. In addition, since the size of the vibrating body in the longitudinal direction can be increased within a range that overlaps the rotation region of the lever, the amplitude of the vibrating body can be increased and the driving efficiency can be improved. That is, a large stroke and high driving efficiency can be realized while downsizing.

  In the drive device of the present invention, the vibrator, the rotor, the first gear portion, the second gear portion, and the lever are each provided with a substantially rectangular casing in plan view, and the vibrator has a longitudinal shape thereof. The rotor is disposed side by side with the vibrating body in the longitudinal direction of the casing, and the pivot shaft of the lever is an end portion on the long side of the casing. It is preferable to arrange | position in the approximate center of the said long side.

According to this invention, the pivot shaft of the lever is provided at substantially the center of the end portion on the long side of the casing, so that the position parallel to the short side of the casing is the reference position of the gear lever and protrudes from the casing. In such a range, the lever can be largely rotated at substantially equal angles on both sides. As a result, it is possible to realize a drive device that allows a large stroke in both directions with respect to the reference position while being compact.
In addition, since the vibrating body and the rotor are arranged adjacent to each other in a plan view, the driving device can be thinned.

An electronic apparatus according to the present invention includes the drive device described above.
According to the present invention, since the drive device has the operations and effects as described above, the same operations and effects can be enjoyed.
That is, since the drive device is small, the size of the entire electronic device can be reduced, and the driven body can be driven with a long stroke by the drive device, which can lead to improvement in performance of the electronic device.

  In the electronic device of the present invention, it is preferable that the electronic device includes a lens as the driven body, and the lens is driven by the driving device.

  According to the present invention, since the lens can be moved back and forth with a long driving distance by the driving device described above, zooming performance, focusing performance, and the like can be improved.

  According to the present invention as described above, it is possible to lengthen the stroke of the driven body while reducing the size.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
Here, a lens unit as an electronic apparatus will be described.
In the description after the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.
The lens unit of the present embodiment is configured to be mounted on a digital camera. The digital camera includes a recording medium for recording an image formed by the lens unit and a case in addition to the lens unit. However, only the lens unit will be illustrated and described below.
Such a lens unit is also mounted on a camera other than a digital camera, a video camera, a camera mechanism of a mobile phone, and the like.

[1. Overall structure of lens unit)
FIG. 1 is a perspective view of the lens unit 1 according to the present embodiment as viewed from the upper left of the front.
The lens unit 1 includes a box-shaped housing 10 in which openings 1A and 1B are formed on a surface intersecting the optical axis O, a lens 20 as a driven member disposed inside the housing 10, and the housing 10. A driving device 30 is provided on the side surface portion 11 and drives the lens 20 to advance and retract along the optical axis O.

Two rod-shaped guide shafts 12 are installed parallel to each other along the optical axis O in the housing 10, and the guide shaft 12 guides the advancement and retreat of the lens 20. The guide shaft 12 penetrates the holding frame 201 that holds the lens 20 along the optical axis O, and also prevents the lens 20 from swinging with respect to the optical axis O.
Further, an opening 111 (FIGS. 5 and 8) having a substantially fan shape in plan view is formed in the side surface portion 11 of the housing 10 on which the driving device 30 is provided.

The lens 20 is configured as a focus lens in the present embodiment, and detailed illustration is omitted. However, the central condensing part and the surrounding frame attaching part are integrally formed of a lens material, and the frame attaching part is A holding frame 201 is provided. The holding frame 201 has a protrusion 202 that protrudes outward from the opening 111 of the housing 10.
The lens 20 can be configured as a zoom lens by appropriately setting the optical characteristics of the lens 20. Further, the lens 20 can be configured as a lens group in which, for example, a concave lens and a convex lens are combined.

[2. Lens drive unit structure]
Next, the drive device 30 will be described. The drive device 30 of the present embodiment is manufactured at the same time as the lens unit 1 is manufactured.
2 and 3 are plan views of the drive device 30. FIG. 2 shows the surface side exposed to the outside when the drive device 30 is attached to the housing 10, and FIG. The opposite back side is shown in FIG. 4 and 5 are side cross-sectional views showing the assembly of the components in the drive device 30. FIG.

[2-1. Overall structure of drive unit]
As shown in FIGS. 2 to 5, the driving device 30 is roughly composed of a rectangular vibrating body 40 having a piezoelectric element 41, a rotor 50 that rotates when vibrations of the vibrating body 40 are transmitted, a rotor 50, a gear lever 60 interlocked with the rotor 50, and a planar rectangular base member into which the vibrating body 40, the rotor 50, the rotor support 53, the pressing spring 55, and the gear lever 60 are incorporated. 70 and unitized.
In addition, the driving device 30 includes a rotor gear portion 51 (first gear portion) provided coaxially and integrally with the rotor 50, a pressing spring 55 that urges the rotor support 53, and a base member in which these are incorporated. 70 and a holding plate 71 that holds each component between the base member 70 and the base plate 70. The holding plate 71 and the base member 70 constitute a casing in the driving device 30.

[2-2. Base member structure]
The structure of the base member 70 and the component layout incorporated in the base member 70 will be described. In addition, the dimension of the longitudinal direction of the base member 70 is about 12 mm in this embodiment.
In the base member 70, the vibrating body 40 and the rotor 50 are arranged in a plane in the longitudinal direction of the base member 70, so that the drive device 30 is thinned. Further, the base member 70 is formed with an opening 701 in which the vibrating body 40 and the rotor 50 are disposed. The vibrating body 40 is disposed substantially along the longitudinal direction of the base member 70, and the rotor 50 is disposed on the short side of the base member 70 adjacent to the vibrating body 40.
A gear lever 60 is disposed on the back side of the base member 70 so as to cross the vibrating body 40. The gear lever 60 is disposed so as to substantially follow the center line along the short direction of the base member 70.
Holes 72 are respectively formed at the four corners of the base member 70, and the base member 70 is fixed to the side surface portion 11 of the housing 10 by screw insertion into each hole 72.

[2-3. (Structure of vibrator)
FIG. 6 is a perspective view of the vibrating body 40. In addition, in FIG. 6, illustration of the circuit board provided in the vibrating body 40 was abbreviate | omitted.
The vibrating body 40 is formed by laminating rectangular piezoelectric elements 41 on both front and back surfaces of a reinforcing plate 42 made of stainless steel or the like, and is formed in a substantially rectangular shape as a whole.
The reinforcing plate 42 is integrally formed with a rectangular portion 42A where the piezoelectric element 41 is disposed and fixing portions 42B which are provided on both sides of the rectangular portion 42A in the width direction and are respectively fixed to the base member 70. An arc-shaped convex portion 421 is formed substantially at the center of one short side of the rectangular portion 42 </ b> A, and this convex portion 421 contacts the rotor 50. In addition, a polygonal convex portion 422 is formed substantially at the center of the other short side of the rectangular portion 42A.

Piezoelectric element 41 includes lead zirconate titanate (PZT (registered trademark)), crystal, lithium niobate, barium titanate, lead titanate, lead metaniobate, polyvinylidene fluoride, lead zinc niobate, lead scandium niobate, etc. It is formed by.
Electrodes 43 are formed on both surfaces of the piezoelectric element 41 by plating with nickel or gold, sputtering, vapor deposition, or the like, and electrodes on the back side (not shown) are in contact with the reinforcing plate 42.

The electrode 43 is divided into five electrode patterns 431 to 435 by grooves 44 formed by etching or the like.
The division pattern of these electrode patterns 431 to 435 is roughly as follows. The rectangular electrode 43 is divided into three equal parts in the width direction by grooves along the longitudinal direction of the piezoelectric element 41, and the electrodes on both sides in the width direction are divided into three equal parts. The electrode patterns 431 to 435 are arranged symmetrically with respect to the center line along the longitudinal direction of the piezoelectric element 41. Specifically, these electrode patterns 431 to 435 have a reduced width dimension at the longitudinal center portion of the piezoelectric element 41, and the electrode patterns 431 and the electrode patterns 432 arranged on both sides in the longitudinal direction of the piezoelectric element 41 are: Alternatively, the electrode pattern 434 and the electrode pattern 435 protrude alternately beyond the longitudinal center of the piezoelectric element 41. As a result, all of the electrode patterns 431 to 435 are arranged at equal widths in the central portion in the longitudinal direction of the piezoelectric element 41, and these electrode patterns 431 to 435 are arranged on a straight line along the short direction of the piezoelectric element 41 (in FIG. Therefore, the wiring work to these electrode patterns 431 to 435 can be simplified.

Among the electrode patterns 431 to 435 thus formed, when a voltage is applied between the electrode patterns 431, 433 and 435 and the reinforcing plate 42 by an external voltage application device, the vibrating element 40 is expanded and contracted by the expansion and contraction of the piezoelectric element 41. Excites vertical primary vibration and bending secondary vibration, and the convex portion 421 of the vibrating body 40 draws a substantially elliptical vibration locus E by a combination of the vertical vibration and the bending vibration. Here, the frequency of the drive voltage applied to the piezoelectric element 41 is determined so that the phase difference between the longitudinal vibration and the bending vibration is appropriate in order to realize a substantially elliptical vibration locus E. In addition, by appropriately setting the dimensions, thickness, material, aspect ratio, electrode division form, and the like of the piezoelectric element 41, the resonance point of the longitudinal vibration and the resonance point of the bending vibration when the vibrating body 40 is vibrated Are close to each other, and the frequency of the driving voltage is selected between the resonance point of the longitudinal vibration and the resonance point of the bending vibration. As a result, each amplitude of the longitudinal vibration and the bending vibration can be secured, so that a favorable vibration locus E can be realized. The vibration trajectory E is inclined with respect to the longitudinal center line of the vibrating body 40, and the rotor 50 is moved in the positive direction (by a friction between the convex portion 421 and a side surface of the rotor 50 in a part of the trajectory E). It rotates in the direction of arrow R + in FIG.
On the other hand, in the case where the electrode patterns 432 and 434 are the target of voltage application instead of the electrode patterns 431 and 435, the target to which the voltage is applied is axisymmetric with respect to the center line along the longitudinal direction of the vibrating body 40. Therefore, the locus of the convex portion 421 is also a substantially elliptical locus that is inclined symmetrically with respect to the locus E with respect to the center line, and the rotor 50 rotates in the reverse direction (the direction indicated by the arrow R- in FIG. 2). .
The waveform of the AC voltage applied to the piezoelectric element 41 is not particularly limited, and for example, a sine wave, a rectangular wave, a trapezoidal wave, or the like can be employed.

As shown in FIG. 2, the vibrating body 40 is provided with a circuit board 45 for connecting the electrode patterns 431 to 435 and the reinforcing plate 42 to an external voltage application device.
The circuit board 45 is made of an insulating flexible board or the like and is screwed to the base member 70. The circuit boards 45 are provided on both surfaces of the vibrating body 40 corresponding to the two piezoelectric elements 41 (circuit boards 45A and 45B). The circuit boards 45A and 45B are connected to each other on the side surfaces of the vibrating body 40. Yes.

Although not shown in the drawings, the circuit boards 45A and 45B are provided with conductive patterns corresponding to the electrode patterns 431 to 435 and the reinforcing plate 42, respectively. Overhanging portion 459 (FIG. 4). This overhang portion 459 is fixed to each electrode pattern 431 to 435 by means of solder or the like at a substantially central position in the longitudinal direction of the piezoelectric element 41 (a position of a black dot (•) in FIG. 6).
By arranging the conductive patterns on the circuit boards 45A and 45B, the electrode patterns 431 and 435 and the electrode patterns 432 and 434 at the diagonal positions of the piezoelectric element 41 are electrically connected to each other, and the two piezoelectric elements 41 are also connected. The corresponding electrode patterns 431 to 435 are electrically connected to each other. On the surface of the circuit board 45A, although not shown, terminals connected to the electrode patterns 431 and 435 on both surfaces of the vibrating body 40 and terminals connected to the electrode patterns 432 and 434 on both surfaces of the reinforcing plate 42 are omitted. And terminals connected to the electrode patterns 433 on both sides of the reinforcing plate 42 are provided side by side. The reinforcing plate 42 is made of a conductive material and itself serves as a terminal. The four terminals thus formed are connected to an external voltage application device.

[2-4. Structure of rotor and rotor support)
The rotor 50 includes a rotation shaft 50A and an annular member 50B provided on the rotation shaft 50A, and is supported by a support hole 53A of the rotor support 53 via a bearing (not shown) such as a ruby.
Further, the rotor gear portion 51 is fixed to the back surface side of the annular member 50B, and the rotor 50 and the rotor gear portion 51 rotate integrally with each other around the rotation shaft 50A.
As shown in FIG. 4, the rotor support 53 includes a plate member 531 and a plate member 532 that are provided on the rotor 50 side (front side) and the rotor gear portion 51 side (back side), respectively. The plate member 532 is fixed to each other with a screw 538.
The plate member 531 extends from the support hole 53 </ b> A to the end portion on the long side of the base member 70, and is pivotally supported on the base member 70 by a rotation pin 539.
A locked portion 533 to which the pressing spring 55 is locked is formed on the short side of the base member 70 with respect to the direction connecting the rotation pin 539 of the plate member 531 and the support hole 53A.

  In this embodiment, the pressing spring 55 is a torsion spring, and the shaft portion 550 is attached to a screw pin 73 provided at one corner of the base member 70. Then, one end 551 of the pressing spring 55 along the long side of the base member 70 is locked to the throat of the base member 70, and the other end 552 along the short side of the base member 70 is locked to the locked portion 533. ing. The pressing spring 55 is locked to the base member 70 and the locked portion 533 in a state where the angle between the one end 551 and the other end 552 is widened, and the rotor support 53 is shown by an arrow in FIG. Energize in the direction. At this time, the rotor 50 pivotally supported by the support hole 53A is also urged, and the side surface of the rotor 50 comes into contact with the convex portion 421 of the vibrating body 40 with an appropriate contact pressure.

[2-5. Gear lever structure)
The gear lever 60 is configured by overlapping a first member 61 and a second member 62 formed by press punching a metal plate or the like.
FIG. 7A shows the first member 61, and FIG. 7B shows the second member 62. The first and second members 61 and 62 are arranged in the order of the second member 62 and the first member 61 from the surface side of the driving device 30 (the side opposite to the housing 10) (FIG. 5).

In the first member 61, a lever gear portion 611 as a second gear portion meshing with the rotor gear portion 51 and a lever portion 612 extending so as to cross the vibrating body 40 are integrally formed, and a step portion 61A bent in the middle. And rotates around the shaft hole 61B.
The lever gear portion 611 is formed with a tooth row 611A centering on the shaft hole 61B and a bent piece 611B protruding to the side where the second member 62 is overlapped.

In the lever portion 612, slits 612A and 612B extending from the position of the shaft hole 61B substantially along the radial direction intersecting the direction of the shaft are formed side by side. The slits 612A and 612B are connected by a slit groove. By these slits 612A and 612B, the lever portion 612 has elasticity in a direction intersecting the radial direction.
As shown in FIG. 2 or the like, the projection 202 of the holding frame 201 of the lens 20 is inserted into the slit 612A on the distal end side of the lever portion 612, and the projection 202 is movable in the radial direction of the shaft hole 61B along the slit 612A. Retained.
Further, in the lever portion 612, the side opposite to the shaft hole 61B of the stepped portion 61A is stepped down to the housing 10 side and extends in the plane direction of the opening 111 formed in the housing 10 as shown in FIG. Thus, when the lever portion 612 is rotated, it does not interfere with the rotor 50. Similarly, as shown in FIG. 5, the side opposite to the stepped side of the stepped portion 61 </ b> A protrudes to the surface side of the driving device 30, and the shaft hole 61 </ b> B is provided in the side surface portion 11 of the housing 10. The rotating pin 112 is inserted. Thereby, thickness reduction of the drive device 30 is achieved.

The second member 62 also has a lever gear portion 621 as a second gear portion, a lever portion 622, and a step portion 62A, and is provided on the side surface portion 11 of the housing 10 in substantially the same manner as the first member 61. It rotates around a shaft hole 62B inserted through the rotating pin 112.
The lever portion 622 is formed with a U-shaped notch 622A wider than the slit 612A of the first member 61, and the protrusion 202 of the lens 20 is loosely fitted into the notch 622A.
In the lever gear portion 621, a tooth row 621A similar to the lever gear portion 611 of the first member 61 and a spring portion 621B extending from the vicinity of the shaft hole 62B toward the tooth row 621A are formed. The spring portion 621 </ b> B is locked to the bent piece 611 </ b> B of the first member 61 in a compressed state, and has a spring property in a direction of urging the second member 62 against the first member 61 in the circumferential direction of the rotation pin 112. Have. In this state, the tooth row 621A of the second member 62 is displaced with respect to the position of the tooth row 611A of the first member 61 due to the backlash at the notch 622A, and as shown in FIG. The teeth of the rotor gear portion 51 to be engaged are sandwiched between the tooth row 611 </ b> A of the first member 61.

[3. Driving lens unit)
The drive of the lens unit 1 demonstrated above is demonstrated.
When a signal related to the focus operation is input to the driving device 30 of the lens unit 1, the driving device 30 moves the lens 20 in the forward direction F from the back side to the front side of the housing 10 based on the operation signal (FIG. 1). ) Or in the backward direction B (FIG. 1) from the front side to the back side.
In the present embodiment, when the lens unit 1 is activated, the lens 20 is positioned at the approximate center in the longitudinal direction of the housing 10 as shown in FIG. 8, and the gear lever 60 is moved from the rotation pin 112 to the base member 70. It extends almost parallel to the short side.
First, when the lens 20 is moved forward, a voltage is applied between the electrode patterns 431, 433, and 435 of the piezoelectric element 41 and the reinforcing plate 42, and the rotor 50 is rotated in the rotation direction R + by the vibration locus E of the convex portion 421. Move. Then, the rotor gear portion 51 also rotates together with the rotor 50, and the gear lever 60 that meshes with the rotor gear portion 51 also rotates, as shown by the one-dot chain line in FIG. At this time, the protrusion 202 held by the gear lever 60 has a moving direction defined along the guide shaft 12 inserted through the holding frame 201 of the lens 20. Moves along the optical axis O direction while displacing the position in the slit 612A. Thus, the lens 20 is driven forward along the optical axis O direction.

  On the other hand, when retracting the lens 20, a voltage is applied between the electrode patterns 432, 433, 434 of the piezoelectric element 41 and the reinforcing plate 42, and the locus of the convex portion 421 (the locus E and the longitudinal direction of the vibrating body 40 are along. The rotor 50 is rotated in the rotational direction R-. As a result, the gear lever 60 moves from the front of the housing 10 indicated by the solid line in FIG. 9 to the rear of the housing 10 through the state of FIG. 8 and as indicated by the dashed line in FIG. To do. As a result, the lens 20 moves backward from the housing 10. Even when the lens 20 moves backward, the projection 202 of the lens 20 moves along the optical axis O while displacing the position in the slit 612A, as in the previous case.

Such forward / backward driving of the lens 20 is shown in the schematic diagram of FIG. The range in which the gear lever 60 rotates through the forward and backward movement of the lens 20 is an arc AR, and the lens 20 has a distance CD ′ corresponding to the string CD along a predetermined direction Z along the string CD of the arc AR. The projection 202 of this moves linearly. That is, the stroke (drive distance) of the lens 20 is the distance CD ′. The predetermined direction Z is a direction along the optical axis O.
Here, by increasing the distance D from the rotation pin 112 of the gear lever 60 to the tip of the gear lever 60 on the opposite side of the rotation pin 112, the arc AR and the string CD can be increased, and the distance CD ′ can be increased. . The length of the distance CD ′ is about 8 mm in this embodiment, and is as large as about 2/3 with respect to the dimension of about 12 mm in the longitudinal direction of the drive device 30.

  When the lens 20 is advanced and retracted, the position of the lens 20 is detected by a position reading sensor (not shown), and is fed back to the control circuit in the driving device 30 to drive and control the lens 20. It is stopped at the position.

According to the present embodiment described above, there are the following effects.
(1) In the driving device 30 of the lens unit 1, when the gear lever 60 rotates, the protrusion 202 is displaced along the direction intersecting the optical axis O in the gear lever 60, and thus interlocked with the rotation of the gear lever 60. Thus, the lens 20 can be linearly driven in a predetermined direction along the optical axis O.
As described above, the drive device 30 includes members having a simple configuration such as the rotor 50, the rotor gear portion 51, and the gear lever 60 in addition to the vibrating body 40, and the vibration of the vibrating body 40 is linked to the rotor 50 and the same. Therefore, it is not necessary to provide a complicated structure of a conventionally used electromagnetic motor or a gear associated therewith, and the structure can be simplified and the drive device 30 can be downsized. Can do.

Further, the vibration of the vibrating body 40 is not directly transmitted to the lens 20, but the lens 20 is driven via the rotor 50, the rotor gear portion 51, and the gear lever 60, so that the position where the vibrating body 40 is disposed is the lens 20. Since the position is not limited to the position along the driving direction, the vibrating body 40 can be provided at a position outside the driving direction of the lens 20. Thereby, the dimension of the driving device 30 in the driving direction of the lens 20 can be reduced.
Furthermore, also in the point which the gear lever 60 overlaps with the vibrating body 40, component arrangement is saved and the drive device 30 can be made smaller.

  In addition, when the rotational movement is received by a cam and converted to linear driving, it is difficult to increase the driveable distance (stroke) of the lens 20 unless a large cam is used. In the present invention, the driving distance CD ′ corresponding to the length of the chord CD connecting both ends of the arc AR that is the rotation locus of the gear lever 60 can be obtained, so that a large stroke of the lens 20 can be ensured while achieving downsizing. .

  In addition, since the lens 20 is driven through the rotor 50 and the gear lever 60 in this way, energy loss due to friction is reduced as compared with the case where the lens 20 is frictionally coupled to the drive shaft that is moved by the vibrating body 40. Less drive efficiency can be achieved.

(2) Since the driving device 30 is small in size, the size of the lens unit 1 or the entire camera can be reduced, and the lens 20 can be driven by the driving device 30 with a long stroke. It can lead to improvement.
That is, since the lens can be moved forward and backward by the driving device 30 with a long driving distance, focusing (focusing) performance can be improved in the camera including the lens unit 1 of the present embodiment.

(3) Since the rotor 50 can be rotated in both directions of R + and R− by switching the vibration locus E of the vibrating body 40, the lens 20 is advanced by the rotation of the rotor 50 in the rotational direction R +, and The lens 20 can be moved backward by the rotation of the rotor 50 in the rotation direction R-. That is, since the lens 20 can be driven in both the forward and backward directions by one vibrating body 40, it is not necessary to prepare two vibrating bodies 40 for moving the lens 20 forward and backward.

(4) Since the vibrating body 40 and the rotor 50 are in contact with each other while being urged by the pressing spring 55, an appropriate frictional force is generated between the vibrating body 40 and the rotor 50, Shaking with the rotor 50 can be prevented. In addition, due to an appropriate frictional force between the vibrating body 40 and the rotor 50, slipping hardly occurs when the vibrating body 40 sends the rotor 50, and driving efficiency can be improved.

(5) Furthermore, since the rotor 50 is biased toward the vibrating body 40 by the biasing of the pressing spring 55 to the rotor support 53, one of the vibrating body 40 and the rotor 50 is biased to the other. In doing so, the position of the vibrating body 40 can be fixed, and the vibration of the vibrating body 40 is stabilized. In addition, since the position of the vibrating body 40 is fixed, wiring to the vibrating body 40 can be facilitated.

(6) In addition, the rotor gear portion 51 provided in the rotor 50 is also urged toward the gear lever 60 by the urging of the pressing spring 55 toward the rotor 50, and the urging means is applied to the vibrating body 40. Compared with the case where it provides, the meshing between the rotor gear part 51 provided in the rotor 50 and the lever gear parts 611 and 621 is stabilized. For this reason, the lens 20 can be stably moved by the gear lever 60.

(7) The lens 20 has a protrusion 202 inserted into the slit 612A, and the gear lever 60 is formed with a slit 612A extending along the radial direction in its rotation. It can be easily realized to be movable in the intersecting direction and held in the gear lever 60.
Further, since the projection 202 is guided along the slit 612A, it is possible to prevent rattling when the lens 20 moves along the direction of the optical axis O.

(8) Since slits 612A and 612B are formed in the gear lever 60 and the protrusion 202 is elastically held by the slit 612A, the protrusion 202 is displaced along the direction intersecting the optical axis O in the gear lever 60, As the movement of the entire protrusion 202, it is possible to prevent rattling when moving along the direction of the optical axis O.

(9) Further, the gear lever 60 has a first and second members 61 and 62, and the second member 62 is biased in the circumferential direction with respect to the first member 61, and the rotor gear. Since the teeth of the portion 51 are sandwiched between the tooth rows 611A and 621A of the first and second members 61 and 62, rattling between the rotor gear portion 51 and the gear lever 60 can be prevented. Thereby, the operation of the gear lever 60 is stabilized, and the lens 20 can be moved to a desired position and stopped. In addition, noise reduction and drive efficiency can be improved.

(10) Further, since the gear lever 60 is arranged so as to intersect the longitudinal direction of the vibrating body 40, the circumferential direction when the gear lever 60 rotates follows the longitudinal direction of the vibrating body 40, Since the rotation region of the gear lever 60 can be made large within the overlapping range, the stroke length can be increased. In addition, since the size of the vibrating body 40 in the longitudinal direction can be increased within a range that overlaps the rotation region of the gear lever 60, the amplitude of the vibrating body 40 can be increased and the driving efficiency can be improved. That is, a large stroke and high driving efficiency can be realized while downsizing.

(11) Since the rotation pin 112, which is the rotation center of the gear lever 60, is provided at substantially the center of the long side end of the base member, the position parallel to the short side of the base member 70 is set to the gear lever 60. As a reference position (state of FIG. 8), the gear lever 60 can be largely rotated at substantially equal angles to both sides within a range not protruding from the base member 70. As a result, it is possible to realize the drive device 30 that is compact and enables a large stroke in both directions with respect to the reference position.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
The lens unit of the present embodiment includes two lenses and two driving devices that drive these lenses.
FIG. 11 is a perspective view showing the lens unit 2 of the present embodiment from the upper left of the front.
Inside the housing 10 of the lens unit 2, a first lens 20A and a second lens 20B are sequentially arranged from the front side. Both the first lens 20A and the second lens 20B are configured as zoom lenses.
In addition, two rod-shaped guide shafts 151 and 152 are arranged in parallel on the upper end portion 14 of the housing 10. These guide shafts 151 and 152 pass through the holding frames 201 of the lenses 20A and 20B and guide the movement of the lenses 20A and 20B along the optical axis O.
Here, the first and second lenses 20 </ b> A and 20 </ b> B are positioned with respect to one guide shaft 151 disposed at the upper left corner of the housing 10. That is, the through hole of the holding frame 201 through which the guide shaft 151 is inserted has a circular cross section, whereas the through hole of the holding frame 201 through which the other guide shaft 152 is inserted has a long hole shape in cross section. .

  A driving device 30 </ b> A that drives the first lens 20 </ b> A is provided on the left side surface portion 11 of the housing 10. The drive device 30A includes a vibrating body 40, a rotor 50, a gear lever 60, and the like, substantially the same as the drive device 30 of the first embodiment. Further, although a detailed illustration of the driving device 30B provided on the upper end portion 14 of the housing 10 and driving the second lens 20B is omitted, the vibrating body 40 of the driving device 30 and the rotor 50 in the first embodiment are omitted. The gear lever 60 has the same configuration as the gear lever 60 and the like.

  In such a lens unit 2, zooming in and zooming out are performed by changing the distance between the first lens 20A and the second lens 20B, that is, the focal length, by zooming. 12 and 13 are left side views of the lens unit 2 and show the operation of the drive device 30A. The driving of the first lens 20A by the driving device 30A will be described with reference to FIGS. 12 and 13, and the description of the driving of the second lens 20B by the driving device 30B that is the same as this will be simplified.

  When the lens unit 2 is activated, the first lens 20A is at a substantially central position of the housing 10 indicated by pA in FIG. 12, and the gear lever 60 of the driving device 30A is also at this position pA. Further, when the lens unit 2 is activated, the second lens 20B is in a position behind the housing 10 indicated by pB, and a gear lever (not shown) of the driving device 30B is also in this position pB. When a zoom operation signal is input from this state, the vibrating body 40 vibrates, and the rotor 50 is sent in the R + direction in FIG. 12 by the vibration locus E (FIG. 6) of the convex portion 421. The gear lever 60 is interlocked with the movement of the rotor 50, and the gear lever 60 rotates to a position on the front side of the housing 10 indicated by qA in FIG. On the other hand, in the driving device 30B, when the gear lever is interlocked with the movement of the rotor and is rotated as much as possible, the gear lever of the driving device 30B rotates to the position on the front side of the housing 10 indicated by qB in FIG. To do.

At this time, the projection 202 of the first lens 20A held by the gear lever 60 through the opening of the housing 10 is displaced from the position pA (FIG. 12) to the position qA (FIG. 12) while displacing the position of the gear lever 60 in the slit 612A. 13) advance along the optical axis O. Similarly, in the driving device 30B, the protrusion (not shown) of the second lens 20B is fed by the gear lever 60B, and the second lens 20B is moved from the position pB (FIG. 12) to the position qB (FIG. 13). It advances along the optical axis O. That is, the first lens 20A and the second lens 20B both move forward and come close to each other, thereby zooming in.
On the other hand, at the time of zooming out, the electrodes to which the voltage is applied are switched in the vibrating bodies 40 of the drive devices 30A and 30B, and the rotor 50 and the gear lever 60 are rotated in the opposite direction (R−). . In response to this, the first and second lenses 20A and 20B retreat from the front side to the rear side of the housing 10 along the optical axis O and are separated from each other.

According to such this embodiment, in addition to the said embodiment, there exist the following effects.
(12) Since the lens unit 2 has a zoom function and the drive devices 30A and 30B can increase the drive distance of the first and second lenses 20A and 20B, the zoom magnification can be increased.

(13) Further, in the configuration including the plurality of lenses 20A and 20B, the driving devices 30A and 30B for driving the lenses 20A and 20B are disposed on the side surface portion 11 and the upper end portion 14, and the side surface portions 11 are disposed. And guide shafts 151 and 152 are provided in the vicinity of the upper end 14. Since the drive devices 30A and 30B are close to the guide shafts 151 and 152 as described above, the moment when the lenses 20A and 20B are sent by the gear lever 60 can be reduced, and the lenses 20A and 20B can be smoothly advanced and retracted. Is possible.

(14) Furthermore, since the lenses 20A and 20B are positioned with respect to the guide shaft 151, the axes of the lenses 20A and 20B can be shared by one guide shaft 151, and the positioning accuracy can be greatly improved.

[Modification of the present invention]
The present invention is not limited to the above-described embodiments, and includes modifications and improvements as described below.
The drive device only needs to include a vibrating body, a rotor, a first gear portion, a second gear portion, and a lever, and other configurations can be appropriately designed. In addition, the driving device of each of the above embodiments is manufactured at the same time as the lens unit. However, the driving device may be manufactured and distributed as a single unit, and the configuration of the driving device in that case is shown in FIG.
The drive device 32 in FIG. 14 includes a plate-like cover member 80 (a casing) on the back side where the gear lever 60 is disposed in the drive device 30 of the first embodiment. The vibrating body 40, the rotor 50, the rotor gear portion 51, the rotor support body 53, the gear lever 60, a pressing spring (not shown), and the like are disposed between the cover member 80 and the cover member 80. Here, in the first embodiment, the cover member 80 is provided with the rotation pin 112 (FIG. 5) provided on the side surface portion 11 of the housing 10 and the opening 111 exposing the stepped portion 61 </ b> A of the gear lever 60. Yes.
Therefore, in order to make the driving device thinner, a configuration in which the cover member 80 is not provided and the rotation pin 112 and the like are provided on the housing 10 as in the first embodiment is suitable.

Further, in each of the above embodiments, the rectangular vibrating body 40, the rotor 50, the rotor gear portion 51, and the thin plate-like gear lever 60 formed with the slits are configured. The shape, material, arrangement, dimensions, rotation angle, and the like of the rotor, the first gear portion, the second gear portion, the lever, etc. are appropriately determined.
For example, the vibrating body 40 may be urged toward the rotor 50 without being limited to the above embodiments. However, in terms of ease of wiring and stabilization of vibration, it is preferable that the vibrating body 40 is fixed and the rotor 50 is urged toward the vibrating body 40 as in the above-described embodiments.
Further, as a configuration in which the lever holds the driven body so as to be movable in a direction crossing a predetermined direction in which the driven body is driven, for example, a protrusion is formed at the rotating tip of the lever, and the protrusion is in the predetermined direction. A freely movable groove may be formed in a lens holding frame or the like.
In each of the above embodiments, the gear lever 60 (the second gear portion and the lever are integrated) is configured by overlapping the first member 61 and the second member 62, and the first and second members 61 and 62 are overlapped. Is biased by the spring portion 621B formed on the second member 62, but the biasing means of the first and second members is not limited to this. For example, in addition to the first and second members, a spring It is possible to energize the first member or the second member with the spring.

  The configuration of the lens unit shown in each of the above embodiments is merely an example, and the shape of the lens housing (such as a rectangular tube or cylinder), the number of lenses, the configuration of the lens group, focusing by zooming in and out of the lens, and zooming Such functions are determined as appropriate. In addition to those exemplified in the above embodiments, for example, a lens unit including a first lens group, a second lens group, and a third lens group is formed from the subject side of the camera, and the first lens group and the second lens group are zoomed. The third lens group may be designed as a focus lens. Alternatively, in the configuration including the first and second lens groups, the first lens group may be designed as a zoom lens and the second lens group as a focus lens.

  Here, the driven body is not limited to a lens, and an image sensor that converts an image formed by the lens into an electrical signal may be the driven body. For example, in the second embodiment, instead of the second lens 20B, a charge-coupled device (Charge-Coupled Device, CCD) as an imaging device can be provided. In this way, the image is formed by the first lens 20A by the charge coupled device by operating the driving device as described above and aligning the charge coupled device with the image forming position of the first lens 20A. Can do.

Further, the arrangement of the driving device for driving the lens is not limited to the above embodiments.
For example, when there are a plurality of lenses, it is possible to arrange a driving device for driving each of the plurality of lenses only on one surface of the lens housing. At this time, it is possible to consider arranging a plurality of driving devices adjacent to each other in a plane and unitizing each driving device in a step with respect to the housing.
On the other hand, when two lenses are provided, not only in the second embodiment, driving devices respectively corresponding to the lenses may be arranged on two side surfaces of the lens housing. However, the second embodiment is recommended for the positional accuracy of the lens.

  The electronic device in which the drive device of the present invention is incorporated is not limited to the lens unit exemplified in each of the above embodiments or a digital camera including the lens unit. For example, a video camera, a microscope, binoculars, a projector, and a mobile phone equipped with a camera mechanism can be exemplified, and the driving device of the present invention can be used for a lens driving portion in these. In addition, it is also possible to drive the head arm of a card type hard disk mounted on the small information terminal device or the like by incorporating the drive device of the present invention into the small information terminal device or the like.

The best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

1 is a perspective view of a lens unit according to a first embodiment of the present invention. The top view (table | surface) of the drive device of the lens in the said embodiment. The top view (back) of the drive device of the lens in the embodiment. FIG. 3 is a side sectional view of the lens driving device in the embodiment. FIG. 3 is a side sectional view of the lens driving device in the embodiment. The perspective view of the vibrating body of the drive device in the embodiment. The top view which shows the gear lever in the said embodiment. The side view which shows operation | movement of the lens unit in the said embodiment. The side view which shows operation | movement of the lens unit in the said embodiment. The schematic diagram which shows operation | movement of the drive device in the said embodiment. The perspective view of the lens unit in 2nd Embodiment of this invention. The side view which shows operation | movement of the lens unit in the said embodiment. The side view which shows operation | movement of the lens unit in the said embodiment. The top view which shows the drive device in the modification of this invention.

Explanation of symbols

1, 2... Lens unit (electronic device), 20, 20A, 20B ... Lens (driven body), 30, 30A, 30B, 32 ... Driving device, 40 ... Vibrating body, 41. ..Piezoelectric element, 43... Electrode, 50... Rotor, 51... Rotor gear part (first gear part), 55... Press spring (biasing means), 60. 61 ... 1st member, 62 ... 2nd member, 70 ... Base member (casing), 112 ... Turning pin (turning shaft of lever), 202 ... Projection, 611 Lever gear part (second gear part), 611A ... tooth row, 612 ... lever part (lever), 612A, 612B ... slit, 621 ... lever gear part (second gear part), 621A ... dentition, 621B ... spring part, 622 ... lever part (lever), R ... arc, B ... backward direction, CD '... drive distance, CD ... string, E ... vibrating locus, F ... forward direction, O ... optical axis, R +. ..Rotation direction (forward direction), R -... Rotation direction (reverse direction), Z ... Predetermined direction.

Claims (10)

A vibrating body that vibrates due to deformation of the piezoelectric element;
A rotor rotating in contact with the vibrating body;
A first gear portion interlocked with the rotor;
A second gear portion meshing with the first gear portion;
A lever that interlocks with the second gear portion and overlaps the vibrating body and holds the driven body movably along a direction that intersects a predetermined direction along a chord of an arc that is a rotation locus thereof. A drive device characterized by the above. The drive device according to claim 1,
The vibrator is configured such that its vibration trajectory can be switched,
The drive device according to claim 1, wherein the rotor is rotatable in a forward direction and a reverse direction in which the vibration trajectories are different from each other. The drive device according to claim 1 or 2,
The vibration device and the rotor are in contact with each other in a state where one is biased toward the other. The drive device according to claim 3, wherein
The position of the vibrating body is fixed,
The drive device according to claim 1, wherein the rotor is provided with a biasing unit that biases the rotor toward the vibrating body. In the drive device according to any one of claims 1 to 4,
The lever is formed with a slit extending along the radial direction in its rotation,
The driven body has a protrusion inserted into the slit. The drive device according to any one of claims 1 to 5,
The second gear portion includes a first member and a second member which are overlapped with each other in the same rotational axis and have tooth rows having substantially the same shape,
One of the first member and the second member is biased in the circumferential direction of the rotation shaft with respect to the other,
The teeth of the first gear portion are sandwiched between the tooth row of the first member and the tooth row of the second member. The drive device according to any one of claims 1 to 6,
The vibrating body has a rectangular shape,
The lever extends from the rotating shaft so as to intersect with the longitudinal direction of the vibrating body. The drive device according to claim 7, wherein
A substantially rectangular casing in plan view in which the vibrator, the rotor, the first gear portion, the second gear portion, and the lever are respectively incorporated;
The vibrator is arranged such that its longitudinal direction is substantially along the longitudinal direction of the casing,
The rotor is arranged side by side with the vibrating body in the longitudinal direction of the casing,
The rotation shaft of the lever is arranged at the approximate center of the long side at the end portion on the long side of the casing. An electronic apparatus comprising the drive device according to claim 1. The electronic device according to claim 9,
A lens as the driven body;
The lens is driven by the driving device.

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