JP2010074986A - Drive device, imaging device equipped with the same, and electronic equipment equipped with the drive device or imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device which is improved in drop impact resistance without having any influence on the driving characteristics of a piezoelectric element, an imaging device equipped with the drive device, and electronic equipment equipped with the drive device or imaging device. <P>SOLUTION: A drive device is equipped with a curvature displacement member 5 having one end fixed and the other end free, with curvature displacement excited on the free end; a friction member 3 for transmitting the curvature displacement excited on the curvature displacement member 5 to drive a driven body 2; a first overcurvature restriction member 9 disposed at a position adjacent to a non-displacement portion 5a of the curvature displacement member 5, which is a portion having a displacement of zero when curvature displacement is excited; a fixed wall 6a of a housing 6 in which the one end of the curvature displacement member 5 is fixed; an intermediate member 4 disposed between the curvature displacement member 5 and the friction member 3; and a pressure-applying member 1 for urging the driven body 2 toward the friction member 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a driving device that drives a driven body using a piezoelectric element, an imaging device including the driving device, and an electronic apparatus including the driving device or the imaging device.

  Conventionally, a driving device for driving a driven body using an electromechanical conversion element (piezoelectric element) has been proposed. Such a driving device is used for driving a lens in an optical device such as a photographing lens of a camera, for example.

  Recently, the drive device has been used as a zoom mechanism or an autofocus mechanism in a camera module mounted on a mobile phone.

  As conventional driving devices, there are driving devices disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-252103 and Japanese Patent Application Laid-Open No. 2007-274790.

  These driving devices have a piezoelectric element that bends when voltage is applied, a holding member that holds one end of the piezoelectric element, a driven body that is in frictional contact with the free end of the piezoelectric element, and a constant force between the piezoelectric element and the driven body. And a pressurizing mechanism for pressing the driven member, and the driven body in frictional contact is moved by bending displacement of the piezoelectric element.

  Moreover, as an apparatus provided with the conventional piezoelectric element (vibrating body), there exists a piezoelectric actuator currently disclosed by Unexamined-Japanese-Patent No. 2007-37394, for example.

In this piezoelectric actuator, by providing a gap around the free end of the vibrating body, the free end of the piezoelectric actuator is captured by the gap during a drop impact, and the impact resistance is improved.
JP 2007-252103 A JP 2007-274790 A JP 2007-37394 A

  However, the piezoelectric element constituting the driving device disclosed in the aforementioned Japanese Patent Application Laid-Open Nos. 2007-252103 and 2007-274790 has a cantilever structure in which one end in the length direction is held by a holding member. However, when a drop impact is applied to the cantilever structure, a large load is applied in the thickness direction of the piezoelectric element depending on the dropping direction, and the displacement amount of the piezoelectric element when driving the driven body is greatly exceeded. Deformation will occur. As a result, there is a problem that the piezoelectric element is damaged. In particular, a portable device such as a mobile phone is assumed to be subject to a drop impact in many cases. For example, when it is used for a driving device such as a photographing lens of a camera (imaging device) built in the mobile phone, the mobile phone is drop resistant. There was a problem with impact.

  Further, the piezoelectric actuator disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2007-37394 improves the drop impact resistance by providing a gap around the free end of the piezoelectric element. In order to further reduce the load on the piezoelectric element at the time of the drop impact, it is conceivable to increase the rigidity by shortening the free end of the piezoelectric element and to suppress the deformation amount of the piezoelectric element at the time of the drop impact. However, such a measure has a problem that it is not preferable because it affects driving characteristics, such as a decrease in the amount of displacement of the piezoelectric element when a voltage is applied.

  The present invention was devised to solve such problems, and an object of the present invention is to provide a drive device with improved impact resistance without affecting the drive characteristics of the piezoelectric element, and an image pickup apparatus equipped with this drive device. And providing an electronic apparatus including the driving device or the imaging device.

  In order to solve the above-mentioned problem, as shown in FIG. 1, the driving device of the present invention includes a bending displacement member 5 having one end fixed, the other end free, and a bending displacement excited on the free end. A position adjacent to the friction member 3 that transmits the bending displacement of the bending displacement member 5 to drive the driven body 2 and the non-displacement portion 5a of the bending displacement member 5 that is a portion where the displacement amount becomes 0 when bending displacement is excited. A first over-bending restricting member 9 disposed on the side, a fixing member for fixing one end of the bending displacement member 5 (fixing wall 6a of the housing 6), and between the bending displacement member 5 and the friction member 3 And the pressurizing member 1 that urges the driven body 2 toward the friction member 3 side.

  The pressurizing member 1 is a member having elasticity, such as a coil spring or a coil spring, and may or may not be provided in the present invention. However, in particular, when the intermediate member is provided as described above, it is more preferable to provide the pressurizing member 1 because the load on the bending displacement member 5 can be increased.

  Thereby, it is possible to prevent the bending displacement portion 5 from being damaged by an impact at the time of dropping without affecting the driving characteristics of the piezoelectric element, and it is possible to improve the drop impact resistance.

  The first overbend restricting member may be disposed in contact with the non-displacement part, and the first overbend restricting member and the non-displacement part are, for example, in line contact or point contact. May be.

  In this case, the excessive bending displacement can be more reliably regulated.

  The first overbending restricting member may be disposed in a non-contact state with the non-displacement portion.

  In this case, the first overbend restricting member can be brought into contact with the non-displacement part only when the overbend displacement occurs.

  Moreover, it may be further provided with a second overbending restricting member that is disposed in the vicinity of the distal end portion of the free end of the bending displacement member and restricts the overbending displacement of the bending displacement member. For example, the second overbending restricting member is preferably arranged in a state where a gap is provided in the vicinity of the distal end portion of the free end of the bending displacement member, and the bending displacement of the bending displacement member is not restricted, Further, it is more preferable to arrange at a position where excessive bending displacement is restricted.

  In this case, breakage of the free end of the bending displacement member can be prevented without hindering excitation of the bending displacement.

  In addition, it is preferable that the first over-bending restricting member and the second over-bending restricting member are members having elasticity because damage to the bending displacement member can be prevented.

  An imaging apparatus according to the present invention includes any one of the driving devices described above, an optical system that forms an image of an object to be imaged, and an imaging element that converts an image formed by the optical system into an electrical signal. The non-driving body is an optical system holding member that holds the optical system.

  Thereby, it is possible to realize an imaging device (for example, a camera module) having impact resistance.

  The electronic apparatus according to the present invention includes any one of the driving devices described above or the imaging device described above.

  Thereby, it is possible to realize an electronic device having impact resistance.

  Since the present invention is configured as described above, the impact resistance can be improved without affecting the drive characteristics of the piezoelectric element.

  Hereinafter, embodiments of a drive device according to the present invention, an image pickup device including the drive device, and an electronic apparatus including the drive device or the image pickup device will be described.

  In the following description, various technically preferable limitations for carrying out the present invention are given, but the scope of the present invention is not limited by the following embodiments and drawings.

<Embodiment 1 of Drive Device>
First, a first embodiment of the drive device of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing Embodiment 1 of the drive device of the present invention, and shows a state where a cover is removed from the housing.

In this specification, the thickness direction of the bending displacement member is the X direction, the length direction of the bending displacement member in the stationary state is the Y direction, the moving direction of the driven body is the Z direction, and the X direction is on the YZ plane. The Y direction is a direction perpendicular to the ZX plane, and the Z direction is a direction perpendicular to the XY plane.
(Structure of the entire drive unit)
In the driving device 10 of the present embodiment, the driven body 2, one end portion is fixed to the housing 6, a bending displacement member 5 in which bending displacement is generated by electrical control, and one end portion of the driving device 10 is connected to the bending displacement member 5. The friction member 3 is connected, and the other end is in frictional contact with the driven body contact portion 2a of the driven body 2 via the contact member 2d, and between the bending displacement member 5 and the friction member 3. The intermediate member 4 provided on the driven body 2 and one end thereof are fixed to the driven body pressurizing portion 2b of the driven body 2 and the other end thereof is fixed to the casing pressurizing portion 6b of the casing 6. And a pressurizing member 1 for urging the driven body 2 toward the friction member 3 side.

  The bending displacement member 5 is a so-called piezoelectric element, and is arranged such that the bending displacement direction is perpendicular to the moving direction (Z direction) of the driven body 2 as shown in FIG. The fixed end (one end) of the bending displacement member 5 is bonded and fixed to the fixed wall 6 a of the housing 6. That is, the fixed wall 6a is arranged so that the wall surface of the fixed wall 6a is parallel to the moving direction (Z direction) of the driven body 2, and the thickness of the bending displacement member 5 is arranged on the wall surface of the fixed wall 6a. The surface orthogonal to the vertical direction is bonded and fixed. The fixed wall 6a may or may not be integrated with the housing 6. However, it is more preferable that the fixed wall 6a is integrated because the number of members can be reduced and the positional accuracy can be improved.

  The pressurizing member 1 and the friction member 3 are disposed so as to sandwich the driven body contact portion 2a and the contact member 2d bonded and fixed to the driven body contact portion 2a. The driven member contact portion 2a and the contact member 2d are constantly urged toward the friction member 3 side.

  The pressurizing member 1 is preferably a coil spring or a member having elasticity, such as a coil spring. In the case of a coil spring, it is more preferable that one end or both ends thereof be wound tightly without elasticity. When one end or both ends of the coil spring are tightly wound with no elasticity, when the coil spring is fixed to the housing 6 or the driven body 2 by using an adhesive or the like, the application area of the adhesive Can be secured greatly. Moreover, since the fixed range does not vary due to manufacturing tolerances or the like by being tightly wound, a stable pressurizing load can be obtained.

  The guide shaft 7 provided in the housing 6 is a guide for smoothly moving the driven body 2 along the Z direction, and the shaft provided perpendicular to the bottom surface of the housing 6 is used as the driven body. 2 through the shaft hole. The guide shaft 7 does not need to be a shaft as long as it guides the driven body 2, and for example, a linear guide or a leaf spring may be used.

  The driven body 2 is always urged toward the bending displacement member 5 by the pressurizing member 1. For this reason, the driven body 2 can maintain a stable position. For example, when the drive device 10 according to the present invention is applied to a portable electronic device such as a mobile phone, the electronic device is highly likely to receive an impact due to dropping or the like. For this reason, when the driving device 10 of this embodiment is used in such an electronic device, the driven shaft 2 is used to maintain the position of the driven body 2 stably, that is, the driven body 2 is a housing. It is necessary to prevent it from coming off the body 6.

  The housing 6 has a frame structure including the pressurizing member 1, the bending displacement member 5, and the like inside, and is necessary for ensuring the strength and function of the driving device 10, but depending on the mounting state of the driving device 10. It may not be necessary. For example, the housing 6 is unnecessary when the driving device 10 of the present embodiment is built in an electronic device or the like and is provided with another structure as an alternative to the housing. However, in the present invention, another structure that replaces the housing is also regarded as the housing of the driving device 10.

Further, the drive device 10 of the present embodiment is provided with a first overbend restricting member 9 described later in contact with the bending displacement member 5.
(Description of friction driven mechanism)
Next, the bending displacement member 5, the intermediate member 4 and the friction member 3 that form the drive mechanism of the drive device 10 according to the present embodiment and the operation thereof will be described.

  FIG. 2 is an explanatory diagram illustrating an example of a bending displacement member, an intermediate member, and a friction member that constitute the drive device illustrated in FIG. 1.

  The bending displacement member 5 is a bimorph type piezoelectric element. For example, as shown in FIG. 2, a laminated piezoelectric element (displacement member 52) is formed on both surfaces (or may be one surface) of a shim member 51 made of a metal plate. It is comprised by forming. The bending displacement member 5 only needs to have a degree of bending displacement necessary to maintain a normal function that the driving device 10 should have. Therefore, the configuration and shape of the bending displacement member 5 are not limited to a specific configuration and shape, and other materials such as a shape memory alloy may be used as the displacement member 52.

  Further, one end of the bending displacement member 5 is a fixed end bonded and fixed to a fixed wall 6a (see FIG. 1) of the housing 6, and the other end is a free end. The friction member 3 is connected to the free end side of the bending displacement member 5 via an intermediate member 4. Furthermore, an electrode portion (not shown) of the bending displacement member 5 is soldered to an electrode terminal (not shown) and is electrically driven by an external drive circuit (not shown).

  Here, an example of the control method used for the movement of the driven body 2 will be described.

  First, when a voltage is applied to the bending displacement member 5, the displacement member 52 formed on one surface of the shim member 51 (the surface on the front side in FIG. 2) contracts under one application condition, and the other application Under the condition, the displacement member 52 formed on the other surface (the front surface in FIG. 2) contracts. As a result, the free end of the bending displacement member 5 swings in the + X direction or the −X direction along a direction substantially parallel to the XY plane as shown by the double-pointed arrows A1 and A2 in FIG. The whole bends.

  On the other hand, the intermediate member 4 is, for example, a downward U-shaped thin plate member, and includes a horizontal beam portion and vertical beam portions respectively extending downward from both ends of the horizontal beam portion. Further, the intermediate member 4 has one vertical beam portion fixed to the bending displacement member 5 and the other vertical beam portion not fixed to the bending displacement member 5 being a free end. That is, the intermediate member 4 has a structure having a free end in the Z direction.

  Accordingly, the voltage applied to the bending displacement member 5 is changed in accordance with the one application condition, so that the displacement member 52 formed on one surface of the shim member 51 is contracted and formed on the other surface of the shim member 51. When the displacement member 52 is extended, the intermediate member 4 swings in the + X direction (the direction indicated by the arrow A1), and the friction member 3 is pressed against the contact member 2d so that the driven body 2 is in the initial state along the guide shaft 7. Slide in the + Z direction from the position. That is, the free end of the intermediate member 4 swings in the + X direction due to the change of the bending displacement member 5 and simultaneously swings in the + Z direction due to the sliding movement of the driven body 2.

  Next, when the state is rapidly changed to the state opposite to the above state, that is, when the expansion and contraction of the displacement member 52 is rapidly reversed, the intermediate member 4 swings in the −X direction (the direction indicated by the arrow A2). Due to the displacement of the intermediate member, a slip (slip) occurs between the friction member 3 and the contact member 2d, and the driven body 2 does not move in the −Z direction or only slightly slides in the −Z direction. is doing. That is, the free end of the intermediate member 4 is swung in the −X direction due to the change of the bending displacement member 5, and at the same time, is slightly swung in the −Z direction due to the sliding movement of the driven body 2.

  Subsequently, the rapid change of the voltage and the change at a constant gradient as described above are repeatedly performed, so that the free end of the intermediate member 4 is excited by the bending movement of the bending displacement member 5 as shown in FIG. As indicated by an arrow B inside, it swings along a direction substantially parallel to the XZ plane. As a result, the friction member 3 moves in the X direction and the Z direction, and the driven body 2 is guided by the guide shaft 7 and moves in the Z direction. The direction indicated by the arrow B is an example.

  That is, in the driving device 10 of the present embodiment, the voltage applied to each electrode portion of the bending displacement member 5 is controlled so that the reciprocating bending speed of the bending displacement member 5 is different, and the driven body 2 and the friction member 3 are controlled. A frictional movement difference is generated by changing the friction force acting between them according to the speed difference at the time of voltage change, and the displacement amount (movement amount) of the driven body 2 in the Z direction is changed. The driving frequency for reciprocally bending the bending displacement member 5 is several kHz or more, more preferably an inaudible ultrasonic frequency (20 kHz or more).

  The control method used for the movement of the driven body 2 described above is an example, and the bending displacement member 5 is changed by changing the arrangement of the shim member 51 and the displacement member 52, the condition for applying the voltage to the electrode portion, and the like. It is possible to change the pattern of bending motion. For example, a method described in a document disclosing a conventional technique such as Patent Document 1 and Patent Document 2 may be used, and description of another example of the control method is omitted here.

  As described above, the intermediate member 4 is disposed between the bending displacement member 5 and the friction member 3, thereby performing displacement direction conversion for moving the friction member 3 in a direction different from the displacement direction of the bending displacement member 5. Has a function. By this function, as shown in FIG. 1, the bending displacement member 5 can be arranged in a direction in which the thickness direction is perpendicular to the Z direction, and the drive device 10 is reduced in the width direction (X direction). Can be achieved.

  In addition, the material of the friction member 3 and the contact member 2d should just select a suitable material in consideration of a mutual friction coefficient, for example, a metal, resin, carbon, etc. are mentioned.

  Further, the intermediate member 4 is not limited to the shape shown in FIG. 2 as long as it has a function of changing the displacement direction, and may be, for example, an “L” -shaped thin plate member.

  FIG. 3 is an explanatory view showing a modification of the intermediate member constituting the drive device shown in FIG.

  The intermediate member 4 is composed of a horizontal beam portion and a vertical beam portion extending downward from one end portion of the horizontal beam portion, and the other end portion of the horizontal beam portion is a bending displacement member 5. It is fixed to one of the corners at the free end (upper corner in FIG. 3).

Further, the friction member 3 is fixed to the Z-direction front end portion of the intermediate member 4 (in the vicinity of the lower end portion of the vertical beam portion not fixed to the bending displacement member 5 in FIGS. 2 and 3). The material of the intermediate member 4 is preferably a metal having elasticity, and examples thereof include SUS (stainless steel), aluminum, phosphor bronze, and the like.
(About drive control method)
In this embodiment, the contact member 2d is a member that is adhered and fixed to the driven body 2 (one side surface of the driven body contact portion 2a in FIG. 1), but the driven body 2 (for example, the driven body contact portion 2a). In this case, the member moves integrally with the driven body 2.

Note that the driven body 2 constituting the driving device 10 of the present embodiment is a member different from an intermediate driven body for driving the lens holding frame described in Patent Document 1 and the like described above. In this embodiment, since the driven body 2 itself is driven by being brought into direct contact with the friction member 3, there is no need to provide an intermediate driven body, and the driving apparatus 10 can be reduced in size and each member arrangement can be reduced. The degree of freedom can be increased. The drive device 10 according to the present embodiment has a configuration that eliminates the need for the intermediate driven body by devising the arrangement of each member as described below.
(Operation of over-bending restricting member)
Next, the operation of the first overbend restricting member 9 constituting the drive mechanism of the drive device 10 of the present embodiment will be described.

  The first over-bending restricting member 9 is arranged in contact with the bending displacement member 5.

  If the first overbending restricting member 9 is not disposed, a space is provided between the bending displacement member 5 and the cover 8. Further, the bending displacement member 5 is in a state in which the pressurization from the pressurizing member 1 is always applied to the cover 8 side via the driven member contact portion 2a, the contact member 2d, the friction member 3 and the intermediate member 4. . Therefore, in this state, when some external force, for example, an impact force due to dropping, is applied to the drive device 10, the bending displacement member 5 is excessively displaced toward the cover 8, and the bending displacement member 5 is damaged. Problems arise.

  In general, the bimorph type piezoelectric element (bending displacement member 5) is made of ceramic or metal. It will be damaged by deformation of several mm. Further, at the time of excessive bending displacement, a large load is also applied to the bonding portion between the bending displacement member 5 and the fixed wall 6a, and as a result, adhesion peeling occurs.

  In order to solve the above-described problem, in the present embodiment, the first over-bending restricting member 9 is arranged to shorten the free length of the bending displacement member 5, and the bending displacement member 5 by applying an impact force at the time of dropping. By limiting the amount of deformation, the drop impact resistance is improved.

In addition, as a material of the 1st overbending control member 9, the member which has the elasticity which relieves an impact force, for example, a rubber material, a gel material, a spring, etc. is especially preferable.
(Position of over-bending restricting member and vibration mode during driving)
The first over-bending restricting member 9 is arranged so as to come into contact with a position that becomes a node of the vibration mode of the bending displacement member 5 when the bending displacement member 5 drives the driven body 2 by a bending motion.
The “node” is a portion where the amount of displacement becomes “0” when the bending displacement member 5 performs a bending motion (when bending displacement is excited). In the present specification, the “non-displacement portion”. Also say. That is, even when the bending displacement is excited, the displacement amount of the non-displacement portion 5a is 0. Therefore, even when the first overbending restricting member 9 is brought into contact with the position of the non-displacement portion 5a, the driving characteristics are not impaired. As in the case where the first overbending restricting member 9 is not disposed, the bending displacement member 5 performs a bending motion.

  When the fixed wall 6a is formed of a material having high rigidity such as a metal material such as SUS or ceramics, the bending displacement member 5 takes a vibration mode of a one-sided beam during resonance driving. Since the bending displacement member 5 is in a state where a load is applied to the distal end portion of the free end by the pressurizing member 1, the value of the amplitude amount and the resonance frequency of the bending displacement member 5 at the time of resonance driving is slightly different depending on the magnitude of the load. Although it changes, the position of the non-displacement part 5a is not changed.

  Even when the material constituting the bending displacement member 5 is changed, the position of the non-displacement portion 5a in the vibration mode is determined by the dimensions of the bending displacement member 5, so that the position of the non-displacement portion 5a is unchanged. .

  For example, when the free length of the bending displacement member 5 is 1, when the intermediate member 4 is excited in the secondary mode, the intermediate member 4 is excited in the tertiary mode, while the intermediate member 4 is excited in the tertiary mode. In such a case, the first overbending restricting member 9 may be arranged so as to come into contact with a position at 0.5 or 0.868 from the fixed end.

  In the secondary mode and the tertiary mode, the first over-bending restricting member is positioned so as not to be in close contact with the bending displacement member 5 when arranged so as to contact the position of 0.774, 0.5, or 0.868. 9 can also be arranged. For example, the first over-bending restricting member 9 is formed in a curved surface or a shape having an acute angle, and the curved surface or the acute angle is disposed in the vicinity of the bending displacement member 5 or arranged in a state of being slightly abutted. Thus, the influence of the regulating member on the bending displacement member 5 may be suppressed.

  The fixed wall 6a may be formed of a material having low rigidity such as polycarbonate (PC), polyphenylene sulfide (PPS), or liquid crystal polymer (LCP).

  FIG. 4 is a top view showing the drive device shown in FIG. 1, in which FIG. 4 (a) shows a state in which the bending displacement member 5 is not bent, and FIG. 4 (b) and FIG. Shows a bent state. In addition, illustration of a cover is abbreviate | omitted in FIG.

When the fixed wall 6a is formed of a material having low rigidity, the fixed wall 6a follows the bending motion of the bending displacement member 5, and the bending displacement member 5 is changed from the state shown in FIG. In order to change to the state shown in FIG. 4B or FIG. 4C, or to change from the state shown in FIG. 4B or FIG. 4C to the state shown in FIG. The bending motion is performed in a state where the substantially central portion of 5 becomes the non-displacement portion 5a. Therefore, when the fixed wall 6a is formed of a material having low rigidity, the first over-bending restricting member 9 may be disposed at the substantially central portion of the bending displacement member 5.
(Example of the shape of the overbend displacement member)
In the embodiment, the shape of the first overbend restricting member 9 is a quadrangular prism shape, but if it is configured to be able to restrict the overbend displacement at a position that becomes the non-displacement part 5a in the vibration mode, Not limited to this.

  FIG. 5 is an explanatory view showing a first modification example of the first overbend restricting member constituting the drive device shown in FIG. 1, and FIG. 6 is a first overbend restriction constituting the drive device shown in FIG. FIG. 7 is an explanatory view showing a second modification example of the member, and FIG. 7 is an explanatory view showing a third modification example of the first overbend restricting member constituting the drive device shown in FIG. 1. 5 to 7, (a) is a perspective view and (b) is a top view. In addition, illustration of a cover is abbreviate | omitted in FIGS.

  As shown in FIG. 5, Modification 1 of the first overbending restricting member 19 has a semi-cylindrical shape, and a curved portion is arranged on the bending displacement member 5 side. The excessive bending restricting member 19 and the bending displacement member 5 are in line contact. By using the first overbend restricting member 19 having such a shape, the first overbend restricting member 19 can be brought into contact with only the non-displacement portion 5 a of the bend displacement member 5. It is possible to regulate the excessive bending displacement when some external force is applied to the driving device 10 without impairing the bending motion.

  Moreover, as shown in FIG. 6, the modified example 2 of the first overbending restricting member 29 has a hemispherical shape, and a curved portion is arranged on the bending displacement member 5 side. The over-bending restricting member 29 and the bending displacement member 5 are in point contact. By using the first overbend restricting member 29 having such a shape, the first overbend restricting member 29 can be brought into contact with only the non-displacement portion 5 a of the bend displacement member 5. It is possible to regulate the excessive bending displacement when some external force is applied to the driving device 10 without impairing the bending motion.

  Furthermore, as shown in FIG. 7, the modified example 3 of the first overbend restricting member 39 has a hemispherical shape, and the flat portion is arranged on the bending displacement member 5 side. One over-bending restricting member 39 is bonded and fixed to the bending displacement member 5. Even when the first overbending restricting member 39 is arranged in this way, the same effect as that of the driving device 10 shown in FIG. 1 can be obtained.

  The first over-bending restricting members 9, 19, 29, 39 are arranged in contact with the bending displacement member 5, but the present invention is not limited to this and is in a non-contact state. You may arrange | position in the bending displacement member 5 vicinity.

<Embodiment 2 of Drive Device>
Next, a second embodiment of the driving apparatus of the present invention will be described with reference to the drawings.

  8A and 8B are explanatory views showing Embodiment 2 of the drive device of the present invention, where FIG. 8A is a perspective view and FIG. 8B is a top view. In addition, illustration of the cover is abbreviate | omitted in the figure (a).

  In the present embodiment, the same reference numerals are assigned to the same components as those of the driving device of the first embodiment described above, and the description thereof is omitted.

  According to the drive device 10 shown in FIG. 1, the first overbending restricting member 9 is arranged so as to come into contact with the non-displacement portion 5 a when the bending displacement member 5 performs a bending motion to excite the intermediate member 4. Thus, it is possible to reduce the damage caused by the excessive bending displacement of the bending displacement member 5 when the driving device 10 receives an impact due to dropping or the like. However, the distance between the distal end portion of the free end of the bending displacement member 5 and the first overbending restriction member 9 disposed on the non-displacement portion 5a is long (the amount of bending when the material used as the bending displacement member 5 breaks). In this case, the tip of the free end of the bending displacement member 5 is excessively displaced with the non-displacement portion 5a as a fulcrum and contacts a cover (not shown) due to an impact applied by dropping or the like. As a result, the bending displacement member 5 may be damaged.

  The drive device 110 of this embodiment is different from the drive device shown in Embodiment 1 in that the drive device 110 includes a second overbend restricting member 11 for restricting the overbend displacement of the distal end portion of the free end.

  The second overbending restricting member 11 is adhesively fixed to the inner wall surface of a cover (not shown), and is disposed in a state where a gap is provided in the vicinity of the free end of the bending displacement member 5.

  The position at which the second overbending restricting member 11 is arranged is determined so as not to contact the tip of the free end during the bending movement when the bending displacement member 5 excites the intermediate member 4. This is because when the non-displacement portion 5a comes into contact, the bending motion of the bending displacement member 5 is affected.

  By disposing the second overbending restricting member 11 in the vicinity of the distal end portion of the free end of the bending displacement member 5, even when an impact is applied due to, for example, dropping, the free end of the bending displacement member 5 is Since the excessive bending displacement of the bending displacement member 5 is restricted by contacting the second overbending restriction member 11, problems such as breakage can be avoided.

  In addition, as a material of the 2nd overbending control member 11, the member which has the elasticity for relieving an impact force, for example, a rubber material, a gel material, a spring, etc. is especially preferable.

Further, the present invention is not limited to the configuration shown in the first and second embodiments described above, and the bending displacement member 5 is formed by the first overbend restricting member 9 and / or the second overbend restricting member 11. As long as the excessive bending displacement is within a range that can be regulated, the same effect can be obtained with a configuration in which a part thereof is changed.
<Embodiment of Imaging Device>
Next, an embodiment of the imaging apparatus of the present invention will be described.

  The imaging apparatus according to the present embodiment is a camera module (a mechanism used for driving a lens of an imaging apparatus such as a camera) provided with the driving apparatus described in the first or second embodiment.

  The camera module includes a driving device 10 according to the first embodiment or the second embodiment, an optical system that forms an object to be imaged, an image sensor that converts an image formed by the optical system into an electrical signal, and the like. It consists of

  The driven body 2 is an optical system holding member that holds the optical system, and an annular lens mounting portion 2c (FIGS. 1, 5A, 6A, and 7) at the center thereof. a lens barrel having a) and FIG. 8A) or a lens holding frame for directly holding the lens.

  In the camera module, the optical system is driven along the optical axis direction (Z direction) by a drive mechanism including the friction member 3 and the bending displacement member 5, so that AF (automatic) of the lens attached to the lens attachment portion 2 c is achieved. Focus) operation can be realized.

According to the imaging apparatus of the present embodiment, it is possible to realize a camera module having impact resistance.
<Embodiment of Electronic Device>
Next, an embodiment of the electronic device of the present invention will be described.

  An electronic apparatus according to the present embodiment includes the driving device described in the first embodiment or the second embodiment or the imaging device described above.

  For example, by mounting the above-described camera module on an electronic device such as a digital camera or a mobile phone, it is possible to improve the impact resistance of the imaging optical system.

  The drive device of the present invention, the image pickup device including the drive device, and the electronic device including the drive device or the image pickup device can be used when providing a product having excellent impact resistance.

It is a perspective view which shows Embodiment 1 of the drive device of this invention. It is explanatory drawing which shows an example of the bending displacement member, intermediate member, and friction member which comprise the drive device shown in FIG. It is explanatory drawing which shows the modification of the intermediate member which comprises the drive device shown in FIG. It is a top view which shows the drive device shown in FIG. It is explanatory drawing which shows the modification 1 of the 1st overbending control member which comprises the drive device shown in FIG. It is explanatory drawing which shows the modification 2 of the 1st overbending control member which comprises the drive device shown in FIG. It is explanatory drawing which shows the modification 3 of the 1st overbending control member which comprises the drive device shown in FIG. It is explanatory drawing which shows Embodiment 2 of the drive device of this invention, The figure (a) is a perspective view, The figure (b) is a top view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,110 Drive device 1 Pressurizing member 2 Driven body 2a Driven body contact portion 2b Driven body pressurizing portion 2c Lens mounting portion 2d Contact member 3 Friction member 4 Intermediate member 5 Bending displacement member 6 Housing 7 Guide shaft 8 Cover 9, 19, 29, 39 First overbend restricting member 11 Second overbend restricting member

Claims (16)

One end is a fixed end, the other end is a free end, and a bending displacement member whose bending displacement is excited on the free end side;
A friction member for transmitting the bending displacement of the bending displacement member to drive the driven body;
A drive device comprising: a first over-bending restricting member disposed at a position adjacent to a non-displacement portion of a bending displacement member, which is a portion where the displacement amount becomes 0 when bending displacement is excited.   The drive device according to claim 1, further comprising a fixing member that fixes one end of the bending displacement member.   The drive device according to claim 1, further comprising an intermediate member disposed between the bending displacement member and the friction member.   The drive apparatus according to claim 1, further comprising a pressurizing member that biases the driven body toward the friction member.   The drive device according to claim 1, wherein the first overbend restricting member is disposed in contact with the non-displacement portion.   The drive device according to claim 1, wherein the first overbend restricting member is disposed in a non-contact state with the non-displacement portion.   The drive device according to claim 5, wherein the first overbend restricting member is arranged in line contact with the non-displacement portion.   The drive device according to claim 5, wherein the first overbend restricting member is disposed in a point contact with the non-displacement portion.   The drive device according to any one of claims 1 to 8, wherein the second overload is disposed in the vicinity of a distal end portion of a free end of the bending displacement member and restricts an excessive bending displacement of the bending displacement member. A drive device further comprising a bending restricting member.   The drive device according to any one of claims 1 to 8, further comprising a second overbending restricting member disposed in a state where a gap is provided in the vicinity of a free end portion of the bending displacement member. Drive device.   11. The driving device according to claim 9, wherein the second overbending restricting member is disposed at a position that does not restrict the bending displacement of the bending displacement member and restricts the overbending displacement.   9. The drive device according to claim 1, wherein the first overbend restricting member is a member having elasticity.   The drive device according to any one of claims 9 to 11, wherein the second overbend restricting member is a member having elasticity.   A drive device according to any one of claims 1 to 13, an optical system that forms an image of an object to be imaged, and an image sensor that converts an image formed by the optical system into an electrical signal. The imaging apparatus according to claim 1, wherein the non-driving body is an optical system holding member that holds the optical system.   An electronic apparatus comprising the drive device according to any one of claims 1 to 13.   An electronic apparatus comprising the imaging device according to claim 14.

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