WO2014174750A1 - Drive apparatus and image pickup apparatus using same - Google Patents

Abstract

These drive apparatus and image pickup apparatus are provided with: an electric machine conversion element for moving a frictionally engaged moving member via a drive member connected to one end; a base body member to be supported by means of a predetermined supporting body, said base body member being connected to the other end of the electric machine conversion element; a hollow columnar member, which has one end thereof connected to the base body member, and which is disposed such that the side surface thereof surrounds the circumference of the electric machine conversion element by having the circumference spaced apart from the side surface; and an elastic member, which is formed of an elastic material, and which is disposed between the side surface of the electric machine conversion element, and the inner surface of the hollow columnar member.

Description

DRIVE DEVICE AND IMAGING DEVICE USING THE SAME

The present invention relates to a drive device using an electromechanical transducer that converts electrical energy into mechanical energy, and an imaging device using the drive device.

In a mechanical device including a movable part, an actuator is usually incorporated to drive the movable part. This actuator is a device that converts input energy into mechanical motion, one of which is referred to as SIDM (Smooth Impact Drive Mechanism, “SIDM” is a registered trademark), for example, an electromechanical conversion such as a piezoelectric element. A driving device using an element is known.

This SIDM drive device is typically an electromechanical conversion element that converts electrical energy into mechanical energy, a drive member that is fixed to one end of the electromechanical conversion element and that transmits the mechanical energy, and the drive member. A moving member and the like engaged with a predetermined friction force are provided. The electromechanical transducer is, for example, a piezoelectric element in which a plurality of piezoelectric layers made of a piezoelectric material are stacked via internal electrodes between each piezoelectric layer. A pair of external electrodes for supplying the electric energy is respectively formed on a pair of side surfaces facing each other along the stacking direction of the piezoelectric elements, and the pair of external electrodes is connected to the plurality of internal electrodes. They are connected alternately one after another. In such a SIDM drive device, when a sawtooth or pulsed drive voltage is applied from an external drive circuit via the pair of external electrodes, the piezoelectric element expands and contracts in the stacking direction. The drive member reciprocates in the longitudinal direction according to the expansion and contraction of the piezoelectric element. Here, when the electromechanical conversion element (here, the piezoelectric element) is repeatedly expanded and contracted so that the moving speed of the driving member is asymmetric between the forward path and the backward path, the moving member is moved by the asymmetric reciprocating motion of the driving member. It moves along the said longitudinal direction, and an electrical energy is converted into the motion of a moving member (for example, refer patent document 1).

In such a SIDM drive device, the electromechanical conversion element and the drive member are usually bonded and fixed by an adhesive such as an epoxy adhesive. Since the electromechanical conversion element expands and contracts, a compressive force and a tensile force are alternately applied to the bonded portion. For this reason, when a drive device is used for a long time, even if it is a minute vibration, an adhesion part may loosen and peel in a long time. Therefore, as such a countermeasure, for example, there is an SIDM driving device disclosed in Patent Document 2. The drive device disclosed in Patent Document 2 further includes a reinforcing member that integrally covers the base portion of the electromechanical conversion element and the base portion of the drive member at a fixed portion between the electromechanical conversion element and the drive member.

On the other hand, such a SIDM driving device is usually formed long in the expansion / contraction direction of the piezoelectric element of the electromechanical transducer. For this reason, when an external force is applied from a direction orthogonal to the contraction direction of the piezoelectric element, the piezoelectric element is bent with respect to the drive shaft of the drive member, and the piezoelectric element may be damaged depending on the bent state. Therefore, as such a countermeasure, for example, there is an SIDM driving device disclosed in Patent Document 3. The driving device disclosed in Patent Document 3 includes a piezoelectric element, a driving shaft that is fixed to one end surface of the piezoelectric element and moves according to expansion and contraction of the piezoelectric element, and a driven member that is frictionally engaged with the driving shaft. A weight member fixed to the other end surface of the piezoelectric element, and the drive shaft and the weight member are supported by a housing. The driving device disclosed in Patent Document 3 is made of an elastic material such as silicon rubber or an elastic adhesive such as a silicon-based adhesive, and is between the inner surface of the housing and the side surface of the piezoelectric element with respect to the expansion / contraction direction. And a support member that elastically supports the piezoelectric element laterally with respect to the expansion / contraction direction. According to Patent Document 3, with this configuration, it is possible to prevent breakage at each part and their joints by the elastic force of the support member.

By the way, as described above, the SIDM drive device is formed long in the expansion / contraction direction of the electromechanical conversion element, so that it is relatively weak to bending stress when subjected to an impact or the like. Even if the reinforcing member that covers the fixing portion between the electromechanical conversion element and the drive member disclosed in Patent Document 2 is used, the electromechanical conversion element that is weak against stress next to the fixing portion reinforced by the reinforcing member has the impact. There is a risk of breakage due to stress caused by the above.

Therefore, a countermeasure using the support member disclosed in Patent Document 3 can be considered. However, since the support member disclosed in Patent Document 3 is arranged between the housing and the piezoelectric element, the impact force received by the housing incorporating the SIDM driving device and the deformation of the housing are as follows: There is a possibility that the piezoelectric element is directly transmitted to the piezoelectric element via the support member and is damaged. In particular, when the support member is formed of an elastic member having a relatively high elastic modulus, there is a high possibility that the piezoelectric element receives a large stress and is damaged. On the other hand, when the support member is formed of an elastic member having a relatively low elastic modulus, the impact force received by the housing and the deformation of the housing are transmitted to the SIDM drive device by the elastic force of the support member. It becomes difficult. However, in this case, vibration in the SIDM driving device due to inertia and the accompanying deflection cannot be suppressed, and eventually, the SIDM driving device is subjected to relatively large stress and may be damaged. .

JP-A-6-123830 JP-A-8-286093 JP 2007-174882 A

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a drive device that can reduce damage caused by stress caused by an impact or the like with a relatively simple configuration, and an imaging device using the drive device. Is to provide.

The drive device and the imaging device according to the present invention include an electromechanical conversion element for moving a frictionally engaged moving member via a drive member connected to one end, and the other end of the electromechanical conversion element. A base member to be connected and supported by a predetermined support, and one end thereof is connected to the base member, and the electromechanical conversion element is arranged so as to be separated from the side surface and surrounded by the side surface. A hollow columnar member and an elastic member formed of an elastic material and disposed between a side surface of the electromechanical conversion element and an inner surface of the hollow columnar member.

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

The drive device and the imaging device according to the present invention can reduce breakage due to stress caused by an impact or the like with a relatively simple configuration.

It is sectional drawing which shows the structure of the imaging device using the drive device of 1st Embodiment. It is a perspective view which shows the structure of the drive device of 1st Embodiment used for the imaging device shown in FIG. It is a figure for demonstrating the 1st coating | coated member in the drive device of 1st Embodiment used for the imaging device shown in FIG. It is a figure for demonstrating the drive pulse supplied to the drive device used for the imaging device shown in FIG. It is a perspective view which shows the structure of the drive device of 2nd Embodiment used for the imaging device shown in FIG. It is a figure for demonstrating the filler in the drive device of 2nd Embodiment used for the imaging device shown in FIG. It is a perspective view which shows the structure of the drive device of 3rd Embodiment used for the imaging device shown in FIG.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably.

FIG. 1 is a cross-sectional view illustrating a configuration of an imaging apparatus using the driving device of the embodiment. As shown in FIG. 1, the imaging apparatus S according to the embodiment includes a driving device IM, an imaging element 30 that converts an optical image into an electrical signal, and one or a plurality of optical elements. An imaging optical system LS that forms an image on the light receiving surface of the imaging element 30. Then, the driving device IM moves the optical element L1 that moves along the optical axis AX direction among the one or more optical elements in the imaging optical system LS, for example, for zooming or focusing. Any of the driving devices IMa, IMb, and IMc in the first to third embodiments is used for such an imaging device S.

(First embodiment)
FIG. 2 is a perspective view showing the configuration of the drive device of the first embodiment used in the imaging device shown in FIG. 2A is a partially exploded perspective view, and FIG. 2B is an overall external perspective view. FIG. 3 is a view for explaining an elastic member in the driving apparatus of the first embodiment used in the imaging apparatus shown in FIG. FIG. 3A shows a state before filling the elastic member 15 (15 ′), FIG. 3B shows a state of filling the elastic member 15 (15 ′), and FIG. 3C shows the filling of the elastic member 15 in the first mode. 3D shows the state after the elastic member 15 is filled, and FIG. 3D shows the state after the elastic member 15 ′ filled with the elastic member 15 ′ in the second mode. FIG. 4 is a diagram for explaining drive pulses supplied to a drive device used in the imaging apparatus shown in FIG. The horizontal axis in FIG. 4 is time, and the vertical axis is voltage.

As shown in FIG. 1, the imaging device Sa using the driving device IMa of the first embodiment includes an elastic adhesive fixing member 10, an electromechanical conversion element 11, a driving member 12, a base member 13, and a moving member. 14, the elastic member 15, the hollow columnar member 16, the pad 17, the spring 18, the drive circuit 20, the image pickup device 30, and the housing 40 (41, 42) (not shown) that accommodates them. 43). In such an imaging device Sa, the driving device IMa includes the elastic adhesive fixing member 10, the electromechanical conversion element 11, the driving member 12, the base member 13, the moving member 14, the elastic member 15, and the hollow columnar member. 16, a pad 17, and a spring 18.

The electromechanical transducer 11 is an element that converts input electrical energy into mechanical energy that expands and contracts, that is, mechanical motion. For example, a piezoelectric that converts input electrical energy into mechanical elastic motion by the piezoelectric effect. Elements and the like. Such a piezoelectric element includes, for example, a laminated body and a pair of external electrodes. The laminated body is formed by alternately laminating a plurality of thin film (layered) piezoelectric layers made of a piezoelectric material and a conductive thin film (layered) internal electrode layer. In the present embodiment, the laminate has a quadrangular prism shape, but is not limited to this, and may be, for example, a polygonal column shape or a cylindrical shape. Each of the plurality of internal electrode layers is configured to face the outside with a pair of outer peripheral side surfaces facing each other. The pair of external electrodes are formed along the stacking direction on the pair of outer peripheral side surfaces in the stacked body, and supply the electric energy to the stacked body, and are sequentially and alternately connected to the plurality of internal electrodes. . Examples of the piezoelectric material include so-called PZT, quartz, lithium niobate (LiNbO ₃ ), potassium tantalate niobate (K (Ta, Nb) O ₃ ), barium titanate (BaTiO ₃ ), lithium tantalate (LiTaO ₃ ). And inorganic piezoelectric materials such as strontium titanate (SrTiO ₃ ).

The driving member 12 is fixedly connected to an end surface of one end in the expansion / contraction direction of the electromechanical transducer element (piezoelectric element in the present embodiment), and mechanical energy converted from electric energy is transmitted by the electromechanical transducer element 11. It is a member. More specifically, in this embodiment, the drive member 12 is a columnar (shaft-shaped) member that is bonded and fixed to the end surface of one end of the laminate in the piezoelectric element with an adhesive. The drive member 12 is supported by a pair of support pieces 41 and 42 extended from a housing 40 (not shown) so as to be movable in parallel with the axial direction a. The pair of support pieces 41 and 42 are arranged at a predetermined interval, and define a moving range of the moving member 14 that frictionally engages the drive member 12 between the pair of support pieces 41 and 42. Yes. As the material of the drive member 12, for example, any material such as metal, resin, and carbon can be used. The cross section orthogonal to the longitudinal direction of the drive member 12 may be any shape such as a rectangle, a polygon, an ellipse, and a circle, but in the present embodiment, the moving member 14 extends along the longitudinal direction of the drive member 12. The cross section is circular so that it can be moved relatively easily. In addition, when this cross section is a rectangle or a polygon, it is preferable that it is chamfered from the said viewpoint.

The base member 13 is a member that is fixedly connected to the other end face of the electromechanical conversion element 11 in the expansion / contraction direction and is supported by the main body member 43 in the casing 40. The base member 13 has an inertial mass greater than that of the drive member 12. More specifically, the base member 13 has a cylindrical shape having a diameter matched to the outer shape of the electromechanical conversion element 11, and is bonded and fixed to the electromechanical conversion element 11 with an adhesive at one end face thereof. Thus, the electromechanical conversion element 11 is supported. The base member 13 is fixed by elastic bonding by the elastic bonding fixing member 10 to the arrangement surface of the main body member 43 in the housing 40 at the other end face where the electromechanical conversion element 11 is not fixed. Since the base member 13 has an inertial mass that is larger than the inertial mass of the drive member 12, the base member 13 is fixed to the body member 43 of the housing 40, so that the base member 13 is stationary with respect to the expansion and contraction motion of the electromechanical transducer 11. Thus, the expansion and contraction motion of the electromechanical conversion element 11 is mainly transmitted to the drive member 12.

As described above, the elastic adhesive fixing member 10 is a member for elastically bonding and fixing the base member 13 to the main body member 43 of the housing 40, and is made of an elastic adhesive. The main body member 43 of the housing 40 corresponds to an example of a predetermined support. The elastic adhesive is, for example, a silicone rubber-based adhesive that cures by reacting with moisture in the air, or an acrylic rubber-based adhesive that cures when irradiated with ultraviolet rays. Since the base member 13 is fixed to the housing 40 by the elastic adhesive in this way, the impact force and deformation transmitted to the driving device IMa due to the impact or the like are alleviated, and compared with the bending force of the connecting portion of each member. The damage of the weak part can be reduced.

The moving member 14 is a member that is engaged with the driving member 12 with a predetermined frictional force, and slides with respect to the driving member 12. In the present embodiment, the moving member 14 is a lens holding frame that supports and holds a lens L1, which is an example of an optical element.

The moving member 14 of the lens holding frame has a slider block 141 formed by extending a part of the outer periphery. A through opening is formed in the slider block 141 along the direction of the optical axis AX, and the drive member 12 is inserted through the through opening. The direction of the optical axis AX and the axial direction a of the drive member 12 are parallel to each other. Further, a notch 142 is formed at the center of the slider block 141, and the radial half of the drive member 12 is exposed at the notch 142. A pad 17 that contacts the half of the driving member 12 in the radial direction is fitted into the notch 142, and a biasing force in the direction toward the driving member 12 is applied to the pad 17 by a spring 18. . With such a structure, the moving member 14 including the pad 17 and the driving member 12 are pressed against each other by the urging force of the spring 18 and frictionally engaged with each other with a predetermined frictional force. The structure that frictionally engages the moving member 14 and the driving member 12 is not limited to such a structure.

The hollow columnar member 16 is connected to the base member 13 at one end, and spaced apart from the side surface in the expansion / contraction direction of the electromechanical conversion element 11 by a predetermined distance so as to surround the periphery of the electromechanical conversion element 11 on the side surface. It is a member to be arranged. In the example shown in FIG. 1, first, the base member 13 includes a lower member having a first diameter (large diameter) short and high columnar shape, and a second diameter (small diameter) short and high column smaller than the first diameter. An upper member having a shape, and the lower member and the upper member are integrally formed by being laminated with their axes aligned. For example, the base member 13 is an integrally sintered product of tungsten alloy. Therefore, an annular (ring-shaped) flat surface surrounding the periphery of the upper member is formed on the base member 13 on the surface of the lower member on which the upper member is laminated. Since the base member 13 has such a shape, the hollow columnar member 16 is generally a hollow columnar body (for example, a cylindrical body) having an inner shape corresponding to the outer shape of the electromechanical transducer 11. The end surface of one end of the hollow columnar member 16 is in contact with and fixed to the flat surface of the lower member of the base member 13, and the inner peripheral surface of the one end is the peripheral surface of the upper member of the base member 13. It is covered and adhesively fixed. As a result, a recess whose bottom surface is the main surface of the upper member of the base member 13 is formed between the side surface (circumferential surface) of the electromechanical conversion element 11 and the inner surface (inner peripheral surface) of the hollow columnar member 16. As described above, the elastic member 15 can be filled in the recess (filling tank). The hollow columnar member 16 is formed of a material such as metal (including an alloy) or resin, for example.

The base member 13 is a columnar member, and the hollow columnar member 16 is a hollow columnar body (for example, a cylindrical body) having an inner shape corresponding to the outer shape of the electromechanical transducer 11. Yes, the end surface of one end of the hollow columnar member 16 is in contact with and fixed to the mounting surface of the main body member 43 of the housing 40, and the inner peripheral surface of the one end covers the peripheral surface of the base member 13. Then, it may be bonded and fixed.

The elastic member 15 is formed of an elastic material, and is disposed between the side surface of the electromechanical conversion element 11 with respect to the expansion / contraction direction and the inner surface of the hollow columnar member 16, and covers part or all of the side surface of the electromechanical conversion element 11. It is a member to do. The elastic member 15 supports the electromechanical conversion element 11 with respect to the hollow columnar member 16. Such an elastic member 15 is obtained by solidifying, for example, an epoxy adhesive or an acrylate adhesive, as will be described later. Preferably, the elastic member 15 is formed of a material having an elastic modulus smaller than that of the electromechanical transducer 11. Since the elastic member 15 is disposed so as to surround the electromechanical conversion element 11 on the side surface, the elastic member 15 works to prevent the electromechanical conversion element 11 from expanding and contracting. Thus, the elastic modulus of the elastic member 15 is the electric machine. Since it is smaller than the elasticity modulus of the conversion element 11, it can suppress that the elastic member 15 prevents the expansion-contraction movement of the electromechanical conversion element 11 from occurring.

For example, the drive device IMa of the first embodiment is manufactured as follows. First, as shown in FIG. 2A, the drive member 12 is bonded and fixed to the end surface of one end of the electromechanical conversion element 11, and the base member 13 is bonded and fixed to the end surface of the other end. Next, the hollow columnar member 16 is bonded and fixed to the base member 13 through the drive member 12 and the electromechanical conversion element 11. For each of these adhesive fixings, for example, an adhesive such as an epoxy adhesive or an acrylate adhesive is used.

When the hollow columnar member 16 is attached to the base member 13 so as to surround the side surface of the electromechanical conversion element 11 with a predetermined interval in this manner, as shown in FIG. Between the side surfaces of the mechanical conversion element 11, an annular recess is formed in plan view with the upper surface of the upper member of the base member 13 as the bottom surface and an opening in the direction opposite to the bottom surface in the axial direction. Then, as shown in FIG. 3B, an adhesive such as an epoxy adhesive or an acrylate adhesive is discharged into the recess by an adhesive discharge device EF-1 or EF-2 that discharges a predetermined adhesive from the opening. Are filled and heat-cured or UV-cured. Thus, as shown in FIGS. 3C and 3D, the electromechanical conversion element 11 is disposed between the side surface of the electromechanical conversion element 11 and the inner surface of the hollow columnar member 16 in contact with the side surface of the electromechanical conversion element 11 and the inner surface of the hollow columnar member 16. The elastic member 15 (15 ′) is formed, and the driving device IMa (IMa ′) of the first embodiment shown in FIG. 2B is manufactured.

Here, as shown in FIG. 3C, the adhesive to the concave portion is filled up to a height in the axial direction of the electromechanical transducer 11 so as not to cover the driving member 12, and the elastic member 15 The electromechanical conversion element 11 may be disposed so as to surround a part of the side surface of the mechanical conversion element 11. Alternatively, as illustrated in FIG. 3D, the driving member 12 is filled up to a height that covers the periphery of the driving member 12, and the elastic member 15 ′ is disposed so as to surround the periphery of the electromechanical conversion element 11 on the entire side surface of the electromechanical conversion element 11. May be. For example, when an impact due to dropping or the like occurs, bending stress is applied to the electromechanical conversion element 11, and this bending stress is greatest in the vicinity of the base member 13 of the electromechanical conversion element 11. Therefore, the elastic member 15 needs to cover at least the vicinity of the base member 13 of the electromechanical transducer 11 as in the first mode shown in FIG. 3C. In such a 1st aspect, since the elastic member 15 is arrange | positioned at a part of side surface in the electromechanical conversion element 11, it can suppress that the expansion / contraction of the electromechanical conversion element 11 is prevented by the elastic member 15. In the second mode shown in FIG. 3D, since the elastic member 15 ′ is disposed on all the side surfaces of the electromechanical transducer 11, the impact force received by the housing 40 due to, for example, dropping or the deformation of the housing 40 is reduced. Transmission to the electromechanical conversion element 11 can be further relaxed, damage can be further reduced, and impact resistance can be enhanced. Further, in the second mode shown in FIG. 3D, when the elastic member 15 ′ covers the drive member 12, the drive member 12 is also integrally covered with the electromechanical conversion element 11. The bending stress applied to the mechanical conversion element 11 can be further reduced.

In the case of the first mode shown in FIG. 3C, the axial length of the hollow columnar member 16 may be up to the position where the elastic member 15 is filled.

1, the drive circuit 20 is a circuit that generates a predetermined drive pulse supplied to the electromechanical conversion element 11 in order to drive the electromechanical conversion element 11. As the drive circuit 20, for example, a known oscillation circuit that oscillates a sawtooth drive pulse shown in FIG. 4 can be used. When the frequency of the sawtooth drive pulse is about 20 to 30 kHz, the vibration frequency is out of the audible range, and the vibration sound that can be heard by the human ear can be reduced. However, the frequency may be any frequency. When the drive pulse of the sawtooth wave shown in FIG. 4 is supplied from the drive circuit 20 to the electromechanical conversion element 11, the electromechanical conversion element 11 becomes loose at the gentle rising portion of the drive pulse of the sawtooth wave. The drive member 12 that is extended and displaced in the expansion / contraction direction and is bonded and fixed to the electromechanical conversion element 11 is also gradually displaced in the axial direction a. In this case, the slider block 141 of the moving member 14 that is frictionally engaged with the driving member 12 moves in the axial direction a together with the driving member 12 by the frictional force. At the rapid falling portion of the sawtooth drive pulse, the electromechanical transducer 11 is rapidly contracted and displaced in the expansion / contraction direction, and the drive member 12 is also displaced in the direction opposite to the axial direction a. In this case, the slider block 141 of the moving member 14 overcomes the frictional force by the inertial force, stays at that position, and does not substantially move. By repeating this continuously, the slider block 141 of the moving member 14 moves in the axial direction a. Then, by reversing the waveform of the sawtooth driving pulse and supplying the electromechanical transducer 11 with a sawtooth driving pulse composed of a rapid rising portion and a subsequent gentle falling portion, the moving member Fourteen slider blocks 141 move in the opposite direction.

Further, for example, the driving circuit 20 includes an H bridge circuit including four known switching elements that oscillate with a rectangular pulse having a predetermined duty ratio (for example, 3: 7 or 7: 3) as a driving pulse, or two switching elements. A half-bridge circuit with elements can be used. The predetermined duty ratio is, for example, 3: 7 or 7: 3, and the traveling direction of the moving member 14 can be reversed by reversing the duty ratio in this way.

The image sensor 30 has R (red), G (green), and B (blue) components according to the amount of light in an optical image of an object (subject) imaged by an imaging optical system LS (not shown) as a whole. This is an element that performs photoelectric conversion to an image signal and outputs it to an image processing circuit (not shown) that performs predetermined image processing. The image sensor 30 is, for example, a CCD image sensor, a CMOS image sensor, or the like.

The imaging optical system LS includes one or more optical elements, and forms an optical image of an object (subject) on the light receiving surface of the imaging element 30. The above-described lens L1 attached to the moving member 14 of the lens holding frame is an optical element that moves along the optical axis AX among the one or more optical elements in the imaging optical system LS. The lens L1 may be a single lens or a lens group including a plurality of lenses. The lens L1 may be, for example, a lens that moves along the optical axis AX to perform focusing (focusing), and, for example, a lens that moves along the optical axis AX to perform zooming (magnification). It may be. The optical image of the object is guided to the light receiving surface of the image sensor 30 along the optical axis AX by the imaging optical system LS including such a lens L1, and the optical image of the object is captured by the image sensor 30.

In the imaging device Sa and the driving device IMa in the first embodiment, the driving device IMa is supported by the main body member 43 of the housing 40 by the base member 13, and the hollow columnar member 16 is connected to the base member 13. The An elastic member 15 is disposed between the side surface of the electromechanical conversion element 11 and the inner surface of the hollow columnar member 16, and the electromechanical conversion element 11 is supported by the hollow columnar member 16 via the elastic member 15. For this reason, in such an imaging device Sa and driving device IMa, for example, the impact force received by the housing 40 due to dropping or the like and the deformation of the housing 40 are transmitted to the base member 13 and the hollow columnar member 16, thereby The member 13 and the hollow columnar member 16 are integrally bent. However, since the base member 13 and the hollow columnar member 16 are connected to each other, the rigidity is increased. As a result, the bending due to the impact force or the deformation is suppressed. can do. The elastic member 15 (15 ′) functions as a spring component and a viscous component disposed between the side surface of the electromechanical conversion element 11 and the inner surface of the hollow columnar member 16 in the dynamic model, so that the bending force is relatively low. The impact force and the deformation transmitted to the weak electromechanical conversion element 11 can be relaxed, and the breakage can be reduced. As described above, in the imaging device Sa and the driving device IMa in the present embodiment, the base member 13 and the hollow columnar member 16 have a function of supporting the driving device IMa with respect to the housing 40, and the impact force and the deformation. The elastic member 15 has a function of suppressing the vibration and deflection of the electromechanical conversion element 11, supports the drive device IMa with respect to the housing 40, and the vibration of the electromechanical conversion element 11 due to the impact force and the deformation. The function of suppressing the bending is divided into different members. The hollow columnar member 16 preferably has a hardness (rigidity) that does not substantially deform and sway as the housing 40 sways with respect to the impact or the like, and supports the elastic member 15. On the other hand, the elastic member 15 preferably has a softness (elasticity) enough to absorb the impact or the like. The hollow columnar member 16 is preferably a metal (including alloy) material having a Young's modulus of about 200 GPa, for example, whereas the elastic member 15 has a Young's modulus (hollow columnar member 16 of, for example, about 10 MPa to 1 GPa). It is preferable that the resin material has a Young's modulus that is smaller by about 4 to 2 digits than the Young's modulus.

From the above, the imaging device Sa and the driving device IMa in the present embodiment as described above can reduce damage due to stress caused by an impact or the like with a relatively simple configuration of the base member 13, the hollow columnar member 16, and the elastic member 15. Can do.

As described above, the elastic member 15 (15 ′) has a function of preventing the electromechanical conversion element 11 from being damaged due to the impact or the like, and also has a function of preventing the electromechanical conversion element 11 from expanding and contracting. Yes. Therefore, the elastic modulus of the elastic member 15 (15 ') is appropriately set according to the performance required for the driving device IMa in consideration of the breakage preventing function and the expansion / contraction motion inhibiting function. For example, when the breakage prevention function is given priority over the expansion / contraction motion inhibiting function, the elastic member 15 (15 ′) is made of, for example, an epoxy adhesive or an acrylate adhesive other than a rubber adhesive having a relatively high elastic modulus. For example, in the case where the expansion / contraction inhibition function has priority over the damage prevention function, the elastic member 15 (15 ′) is preferably a silicone rubber adhesive or an acrylic rubber adhesive having a relatively low elastic modulus. As described above, the elastic member 15 (15 ′) preferably has an elastic modulus smaller than that of the electromechanical transducer 11.

Next, another embodiment will be described.

(Second Embodiment)
FIG. 5 is a perspective view illustrating a configuration of a driving device according to a second embodiment used in the imaging device illustrated in FIG. 1. 5A and 5C are partially exploded perspective views, FIG. 5B is an overall external perspective view after the covering member 19 is mounted, and FIG. 5D is an overall external perspective view. FIG. 6 is a view for explaining an elastic member in the driving device of the second embodiment used in the imaging device shown in FIG. 1. FIG. 6A shows a state before filling of the elastic member 15 (15 ″), FIG. 6B shows a state of filling of the elastic member 15 (15 ″), and FIG. 6C shows the filling of the elastic member 15 in the third mode. 6D shows the state after the elastic member 15 is filled, and FIG. 6D shows the state after the elastic member 15 ″ filled with the elastic member 15 ″ in the fourth embodiment.

The driving device IMb in the second embodiment further includes a covering member 19 that covers a fixed portion between the electromechanical conversion element 11 and the driving member 12 with respect to the driving device IMa in the first embodiment.

As shown in FIG. 1, the imaging device Sb using the driving device IMb of the second embodiment includes an elastic adhesive fixing member 10, an electromechanical transducer 11, a driving member 12, a base member 13, and a moving member. 14, an elastic member 15, a hollow columnar member 16, a covering member 19 indicated by a broken line, a pad 17, a spring 18, a drive circuit 20, an image pickup device 30, and the whole housing these components. And a casing 40 (41, 42, 43) not provided. In such an imaging device Sb, the driving device IMb includes the elastic adhesive fixing member 10, the electromechanical transducer 11, the driving member 12, the base member 13, the moving member 14, the elastic member 15, and the hollow columnar member. 16, a covering member 19, a pad 17, and a spring 18.

In these second embodiments, the elastic adhesive fixing member 10, electromechanical conversion element 11, driving member 12, base member 13, moving member 14, elastic member 15, hollow columnar member 16, pad 17, spring 18, driving circuit 20, imaging The element 30 and the housing 40 are respectively the elastic adhesive fixing member 10, the electromechanical conversion element 11, the driving member 12, the base member 13, the moving member 14, the elastic member 15, the hollow columnar member 16, and the pad 17 in the first embodiment. Since this is the same as the spring 18, the drive circuit 20, the image sensor 30, and the housing 40, description thereof is omitted.

The covering member 19 is a member that covers a fixed portion between the electromechanical conversion element 11 and the driving member 12. More specifically, the covering member 19 covers the base portion of the electromechanical conversion element 11 in the vicinity of the fixed portion, and has a first hollow short columnar portion having an inner shape corresponding to the outer shape of the electromechanical conversion element 11. 191, a second hollow short columnar portion 192 having an inner shape corresponding to the outer shape of the driving member 12 covering the base of the driving member 12 near the fixed portion, and a first hollow short columnar portion 191 And an annular connecting portion 193 that connects the one end and the other end of the second hollow short columnar portion 192 to each other. In the example shown in FIG. 5, the first hollow short high columnar portion 191 is a hollow short high columnar column member, and the second hollow short high columnar portion 192 is a short high tubular member (a hollow short high columnar member). The annular connecting portion 193 is an annular plate member in which a circular opening having a diameter corresponding to the outer diameter of the second hollow short columnar portion 192 is formed, and corresponds to the outer shape of the first hollow short columnar portion 191. This is an annular plate member having an outer shape of a certain size. The covering member 19 is formed of a material such as metal or resin, for example.

For example, the drive device IMb of the second embodiment is manufactured as follows. First, similarly to the drive device IMa of the first embodiment, as shown in FIG. 5A, the drive member 12 and the base member 13 are bonded and fixed to the end surfaces at both ends of the electromechanical transducer 11 respectively.

Next, the driving member 12 is inserted into the second hollow short columnar portion 192 from the other end of the first hollow short columnar portion 191, and the inside is filled with an adhesive, so that the first hollow short columnar portion 191 is filled. The base of the electromechanical conversion element 11 is fitted in For example, an adhesive such as an epoxy adhesive or an acrylate adhesive is used as the adhesive. As a result, as shown in FIG. 5B, the electromechanical conversion element 11, the drive member 12, and the covering member 19 are integrally bonded and fixed so as to cover the fixed portion between the electromechanical conversion element 11 and the drive member 12. . The driving member 12 and the base member 13 may be bonded to the electromechanical conversion element 11 and the covering member 19 may be bonded to the fixed portion at the same time.

Hereinafter, as shown in FIGS. 5C, 6A, and 6B, similarly to the driving device IMa of the first embodiment, the hollow columnar member 16 is bonded and fixed to the base member 13, and the adhesive discharge device EF-1 is discharged from the opening. , EF-2 fills the recess with an adhesive that becomes the elastic member 15, and is cured. As a result, as shown in FIGS. 6C and 6D, the electromechanical conversion element 11 is disposed between the side surface of the electromechanical conversion element 11 and the inner surface of the hollow columnar member 16 in contact with the side surface of the electromechanical conversion element 11 and the inner surface of the hollow columnar member 16. The elastic member 15 (15 ″) is formed, and the driving device IMb (IMb ′) of the second embodiment shown in FIG. 5D is manufactured.

Here, as shown in FIG. 6C, the adhesive to the concave portion is filled up to the height of the middle position in the axial direction of the electromechanical transducer 11 so as not to cover the covering member 19, and the elastic member 15 The electromechanical conversion element 11 may be disposed so as to surround a part of the side surface of the mechanical conversion element 11. Alternatively, as shown in FIG. 6D, the covering member 19 is filled up to a height that covers the periphery of the first hollow short columnar portion 191, and the elastic member 15 ″ further includes the side surface of the covering member 19 and the hollow columnar member 16. 6D, the hollow columnar member 16 is disposed so as to surround the periphery of the covering member 19 on the side surface of the covering member 19 while being separated from the side surface of the covering member 19. For example, when an impact due to dropping or the like occurs, bending stress is applied to the electromechanical conversion element 11, but this bending stress is the largest in the vicinity of the base member 13 of the electromechanical conversion element 11, and thus the elastic member 15. As in the first mode shown in Fig. 3C, it is necessary to cover at least the vicinity of the base member 13 of the electromechanical transducer 11 as in the third mode shown in Fig. 6C. ,Up Since the elastic member 15 is arrange | positioned in a part of side surface in the electromechanical transducer 11 like the 1st aspect of this, it can suppress that the expansion / contraction of the electromechanical transducer 11 is prevented by the elastic member 15. And FIG. In the fourth mode, the elastic member 15 ″ is also arranged on the side surface of the covering member 19, so that the impact force and the deformation transmitted to the electromechanical conversion element 11 can be further alleviated, and damage is prevented. It can reduce more and can improve impact resistance. Further, in the fourth embodiment shown in FIG. 6D, when the elastic member 15 ″ covers the first hollow short columnar portion 191 of the covering member 19, the driving member 12 is also covered, and the driving member 12 also has the first hollow short height. Since the electromechanical conversion element 11 is integrally covered via the columnar portion 191, the bending stress applied to the electromechanical conversion element 11 when the impact occurs can be further reduced.

In the case of the third mode shown in FIG. 6C, the axial length of the hollow columnar member 16 may be up to the position where the elastic member 15 is filled.

Since the imaging device Sb and the driving devices IMb and IMb ′ according to the second embodiment further include the third covering member 19, the area to be bonded by the adhesive is widened, and thus the electromechanical conversion element 11 and the driving member. 12 can be bonded and fixed more firmly. Therefore, the imaging device Sb and the driving devices IMb and IMb ′ according to the second embodiment can further reduce the breakage of the fixed portion due to the stress caused by the impact or the like with a relatively simple configuration.

Next, another embodiment will be described.

(Third embodiment)
FIG. 7 is a perspective view illustrating a configuration of a drive device according to a third embodiment used in the imaging device illustrated in FIG. 1.

In the driving devices IMa (IMa ′) and IMb (IMb ′) in the first and second embodiments, the base member 13 and the hollow columnar member 16 are separate, but in the driving device IMc in the third embodiment. The base member 13 and the hollow columnar member 16 are integrally formed.

As shown in FIG. 1, the imaging device Sc using the driving device IMc of the third embodiment includes an elastic adhesive fixing member 10, an electromechanical conversion element 11, a driving member 12, a moving member 14, and an elastic member. 15, a hollow columnar base member 51, a pad 17, a spring 18, a drive circuit 20, an image sensor 30, and a housing 40 (41, 42, 43) that accommodates these and not shown in its entirety. It has. In such an imaging device Sc, the driving device IMc includes the elastic adhesive fixing member 10, the electromechanical transducer 11, the driving member 12, the moving member 14, the elastic member 15, the hollow columnar base member 51, and the pad. 17 and a spring 18.

The elastic adhesive fixing member 10, the electromechanical conversion element 11, the drive member 12, the moving member 14, the elastic member 15, the pad 17, the spring 18, the drive circuit 20, the image pickup element 30, and the housing 40 in the third embodiment are respectively The elastic adhesive fixing member 10, the electromechanical conversion element 11, the driving member 12, the moving member 14, the elastic member 15, the pad 17, the spring 18, the driving circuit 20, the imaging element 30, and the housing 40 in the first embodiment. Since there is, explanation is omitted.

In the example shown in FIG. 7, the elastic member 15 is in the fourth mode shown in FIG. 6D, but may be in the third mode shown in FIG. 6C.

1 may not be provided as in the first embodiment, and may be provided as in the second embodiment. In the example shown in FIG. 7, in order to further improve the impact resistance, the driving device IMc of the third embodiment including the covering member 19 is illustrated.

The hollow columnar base member 51 is a member in which the above-described base member 13 and the hollow columnar member 16 are integrally formed, and is a member having both the function of the base member 13 and the function of the hollow columnar member 16. More specifically, as shown in FIG. 7, the hollow columnar base member 51 is a bottomed hollow columnar member with one end face closed. The bottom portion of the hollow columnar base member 51 is formed thicker than the thickness of the peripheral wall portion functioning as the hollow columnar member 16 described above in order to function as the above-described base member 13. Such a hollow columnar base member 51 is integrally formed of metal (including an alloy), resin, or the like.

Since the imaging device Sc and the driving device IMc in the third embodiment use the hollow columnar base member 51 having both the function of the base member 13 and the function of the hollow columnar member 16, the number of assembling steps can be reduced. Can be assembled more easily.

In these first to third embodiments described above, the elastic member 15 may contain a thermally expandable microcapsule. The heat-expandable microcapsule is a member that expands by heating, for example, about 4 to 5 times in diameter to increase its volume. Thermally expandable microcapsules are, for example, lower aliphatic hydrocarbons such as isobutane, pentane, and hexane, low-boiling halogen hydrocarbons, and volatile organic solvents such as methylsilane as expansion agents, vinylidene chloride, acrylonitrile, acrylate esters. A member encased in a thermoplastic resin made of a copolymer such as methacrylic acid ester.

Such an imaging device S (Sa, Sb, Sc) and a driving device IM (IMa (IMa ′), IMb (IMb ′), IMc) are provided between the side surface of the electromechanical transducer 11 and the inner surface of the hollow columnar member 16. After the elastic member 15 (15 ′, 15 ″) is disposed between the heat-expandable microcapsules, the elastic member 15 (15 ′, 15 ″) is converted into the electromechanical transducer 11 and the hollow columnar member 16. Can be pressed and adhesion with them can be improved.

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

A drive device according to one aspect is coupled to an electromechanical conversion element that converts electrical energy into mechanical energy that expands and contracts, and one end of the electromechanical conversion element in a direction of expansion and contraction, and the mechanical energy is transmitted to the drive device. A driving member for moving the moving member engaged by the frictional force of the base member, a base member connected to the other end in the expansion / contraction direction of the electromechanical transducer and supported by a predetermined support, and one end Is connected to the base member, and is formed of an elastic material and a hollow columnar member that is disposed so as to surround the electromechanical conversion element at the side surface apart from the side surface with respect to the expansion and contraction direction of the electromechanical conversion element. An elastic member disposed between a side surface of the electromechanical conversion element and an inner surface of the hollow columnar member and supporting the electromechanical conversion element;

In such a drive device, the drive device is supported on a predetermined support by a base member, a hollow columnar member is connected to the base member, and the side surface of the electromechanical transducer and the inner surface of the hollow columnar member are An elastic member that supports the electromechanical conversion element is disposed between them. For this reason, in such a driving device, for example, the impact force received by the casing due to dropping or the like and the deformation of the casing are transmitted to the base member and the hollow columnar member, and thereby the base member and the hollow columnar member bend. However, since the base member and the hollow columnar member are connected to each other, the rigidity becomes high, and as a result, the impact force and the bending due to the deformation can be suppressed. In the mechanical model, the elastic member functions as a spring component and a viscous component disposed between the side surface of the electromechanical transducer and the inner surface of the hollow columnar member, so that the impact transmitted to the electromechanical transducer is transmitted. The force and the deformation can be relaxed, and the damage can be reduced. As described above, in the drive device of the present invention, the base member and the hollow columnar member have a function of supporting the drive device with respect to the support, and vibration and deflection of the electromechanical transducer due to the impact force and the deformation. The elastic member is responsible for suppressing the vibration, and the function of supporting the driving device with respect to the support and the function of suppressing the vibration and deflection of the electromechanical transducer due to the impact force and the deformation are divided into separate members. It has been. Therefore, such a drive device can reduce damage caused by stress caused by an impact or the like with a relatively simple configuration of the base member, the hollow columnar member, and the elastic member.

In another aspect, in the above-described driving device, the elastic member has an elastic modulus smaller than that of the electromechanical transducer.

In such a drive device, the elastic member has an elastic modulus smaller than that of the electromechanical transducer, so that the elastic member can prevent the elastic member from expanding and contracting.

In another aspect, in the above-described driving device, the elastic member contains a thermally expandable microcapsule.

In such a driving device, after the elastic member is disposed between the side surface of the electromechanical transducer and the inner surface of the hollow columnar member, the elastic member is thermally expanded by the thermal expansion microcapsule. A mechanical conversion element and the said hollow columnar member can be pressed, and adhesiveness with them can be improved.

In another aspect, in the above-described driving device, the elastic member is disposed so as to surround the electromechanical conversion element at a part of the side surface of the electromechanical conversion element.

In such a drive device, the elastic member is arranged on a part of the side surface, and therefore it is possible to suppress the expansion and contraction of the electromechanical conversion element from being obstructed by the elastic member.

In another aspect, in these above-described driving devices, the elastic member is disposed so as to surround the electromechanical transducer at all of the side surfaces of the electromechanical transducer.

In such a drive device, since the elastic member is disposed on all of the side surfaces, the impact force and the deformation transmitted to the electromechanical conversion element can be further reduced, damage can be further reduced, Impact properties can be increased.

In another aspect, the above-described driving device further includes a covering member that covers a fixed portion between the electromechanical conversion element and the driving member.

Since such a driving device further includes a covering member, it is possible to further reduce the breakage of the fixed portion due to stress caused by impact or the like with a relatively simple configuration.

In another aspect, in the above-described driving device, the hollow columnar member is further disposed so as to be separated from the side surface of the covering member and surround the periphery of the covering member by the side surface of the covering member. The member is further disposed between the side surface of the covering member and the inner surface of the hollow columnar member.

In such a drive device, since the elastic member is also arranged on the side surface of the covering member, the impact force and the deformation transmitted to the electromechanical conversion element can be further relaxed, and damage can be further reduced. Can improve impact resistance.

In another aspect, in the above-described driving device, the base member and the hollow columnar member are integrally formed.

In such a drive device, since the base member and the second covering member are integrally formed, the number of assembling steps can be reduced and the assembly can be performed more easily.

Further, an imaging device according to another aspect includes an electric image obtained by driving any one of the above-described driving devices, a moving member engaged with the driving member of the driving device with a predetermined frictional force, and an optical image. An image pickup device that converts the signal into a typical signal; and an image pickup optical system that forms an optical image of an object on a light receiving surface of the image pickup device. An optical element that moves along the optical axis direction among the plurality of optical elements is attached to the moving member of the driving device.

Since such an imaging apparatus includes any one of the above-described driving apparatuses, damage to the driving apparatus due to stress caused by impact or the like can be reduced with a relatively simple configuration. Therefore, such an imaging apparatus can improve impact resistance.

This application is based on Japanese Patent Application No. 2013-91106 filed on Apr. 24, 2013, the contents of which are included in the present application.

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

According to the present invention, it is possible to provide a driving device and an imaging device using the driving device.

Claims (9)

An electromechanical transducer that converts electrical energy into elastic mechanical energy;
A driving member connected to one end of the electromechanical conversion element in the direction of expansion and contraction to move a moving member engaged with a predetermined frictional force by transmitting the mechanical energy;
A base member coupled to the other end of the electromechanical conversion element in the expansion / contraction direction and supported by a predetermined support;
A hollow columnar member connected at one end to the base member, and disposed so as to surround the electromechanical conversion element at the side surface apart from the side surface with respect to the stretching direction of the electromechanical conversion element;
An elastic member formed of an elastic material, disposed between a side surface of the electromechanical conversion element and an inner surface of the hollow columnar member, and an elastic member that supports the electromechanical conversion element;
Drive device. The elastic member has an elastic modulus smaller than that of the electromechanical transducer;
The drive device according to claim 1. The elastic member contains a thermally expandable microcapsule,
The drive device according to claim 1 or 2. The elastic member is arranged so as to surround the periphery of the electromechanical transducer at a part of the side surface of the electromechanical transducer.
The drive device according to any one of claims 1 to 3. The elastic member is arranged so as to surround the periphery of the electromechanical transducer with all of the side surfaces of the electromechanical transducer.
The drive device according to any one of claims 1 to 3. A covering member that covers a fixed portion of the electromechanical transducer and the driving member;
The driving device according to any one of claims 1 to 5. The hollow columnar member is further disposed so as to surround the periphery of the covering member on the side surface of the covering member, spaced from the side surface of the covering member,
The elastic member is further disposed between a side surface of the covering member and an inner surface of the hollow columnar member.
The drive device according to claim 6. The base member and the hollow columnar member are integrally formed.
The driving device according to any one of claims 1 to 7. A driving device according to any one of claims 1 to 8,
A moving member engaged with the driving member of the driving device with a predetermined frictional force;
An image sensor that converts an optical image into an electrical signal;
An imaging optical system that includes one or a plurality of optical elements, and that forms an optical image of an object on a light receiving surface of the imaging element;
An optical element that moves along the optical axis direction among the one or more optical elements in the imaging optical system is attached to the moving member of the drive device.
Imaging device.

Images