Patent Publication Number: US-2013229721-A1

Title: Drive unit, method of manufacturing the same, lens module, and image pickup unit

Description:
TECHNICAL FIELD 
     The present invention relates to a drive unit that uses a predetermined actuator device, to a method of manufacturing the drive unit, and to a lens module and an image pickup unit that include such a drive unit. 
     BACKGROUND ART 
     Recently, mobile electronic apparatuses such as mobile phones, personal computers (PC), and PDAs (personal digital assistants) have been remarkably obtaining high functions and a mobile electronic apparatus is typically provided with an image pickup function by providing a lens module. Such mobile electronic apparatuses perform operation such as focusing and zooming by allowing a lens in the lens module to travel along an optical axis thereof. 
     It has been typical that movement of a lens in a lens module is performed using, for example, a voice coil motor, a stepping motor, or the like as a drive section. On the other hand, recently, those utilizing a predetermined actuator device as the drive section have been developed in terms of reducing size. Examples of such actuator devices include a polymer actuator device (see Patent Literatures 1 and 2), a piezoelectric device, and a bimetal device. Out of these devices, the polymer actuator device may be, for example, a device in which an ion-exchange resin film is interposed between a pair of electrodes. In such a polymer actuator device, a potential difference is generated between the pair of electrodes, and thereby, the ion-exchange resin film is displaced in a direction perpendicular to a film plane. 
     CITATION LIST  
     Patent Literature 
     [Patent Literature 1] Japanese Unexamined Patent Application Publication No. 2006-293006 
     [Patent Literature 2] Japanese Unexamined Patent Application Publication No. 2006-172635 
     SUMMARY OF THE INVENTION 
     Typically, a drive unit using an actuator device as described above is a cantilever actuator that drives a driving target by fixing a first end portion (fixed portion) thereof and displacing a second end portion (movable portion) thereof. In recent years, it has been desired to reduce width (length in a direction perpendicular to a direction extending from the first end toward the second end of the actuator device) of a cantilever as much as possible, for example, in terms of freedom in design (size reduction in structure) in such a cantilever actuator. 
     However, since it may be necessary to support the driving target by the cantilever, it may be necessary to secure a certain width to allow the actuator device to have sufficient strength (mechanical strength) to support the driving target. Therefore, there has been a limit in reducing dimensions in a width direction of the cantilever. Accordingly, it has been desired to propose a drive unit capable of reducing size while maintaining drive characteristics. 
     The present invention has been made in view of the forgoing issue and it is an object of the present invention to provide a drive unit capable of reducing size while maintaining drive characteristics, a method of manufacturing the drive unit, a lens module, and an image pickup unit. 
     A drive unit according to an embodiment of the present invention includes: a fixing member; an actuator device having a first end portion directly or indirectly fixed by the fixing member; and a reinforcing member provided on part or all of the actuator device. 
     A lens module according to an embodiment of the present invention includes: a lens; and the above-described drive unit according to the embodiment of the present invention driving the lens. 
     An image pickup unit according to an embodiment of the present invention includes: a lens; an image pickup device acquiring an image pickup signal resulting from imaging by the lens; and the above-described drive unit, driving the lens, according to the embodiment of the present invention. 
     A method of manufacturing a drive unit according to an embodiment of the present invention includes: forming an actuator device; forming a reinforcing member on part or all of the actuator device; and directly or indirectly fixing a first end portion of the actuator device by a fixing member. 
     In the drive unit, the method of manufacturing the drive unit, the lens module, and the image pickup unit according to the embodiments of the present invention, the reinforcing member is provided on part or all of the actuator device. Therefore, mechanical strength of the actuator device is secured even when a width of the actuator device (length in a direction perpendicular to a direction extending from the first end toward a second end of the actuator device) is narrowed. 
     According to the drive unit, the method of manufacturing the drive unit, the lens module, and the image pickup unit according to the embodiments of the present invention, the reinforcing member is provided on part or all of the actuator device. Therefore, mechanical strength of the actuator device is secured while setting the width of the actuator device to be narrow. Therefore, size reduction is achievable while maintaining drive characteristics. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic plan view illustrating an outline configuration of a drive unit according to an embodiment of the present invention. 
         FIG. 2  is a schematic view illustrating a side-face configuration of the drive unit shown in  FIG. 1 . 
         FIG. 3  is a cross-sectional view illustrating a detailed configuration of an actuator device (polymer actuator device) shown in  FIG. 1 . 
         FIG. 4  is a schematic cross-sectional view for explaining about basic operation of the polymer actuator device shown in  FIG. 3 . 
         FIG. 5  is a schematic view illustrating an outline configuration and operation of a drive unit according to Comparative Example 1. 
         FIG. 6  is a schematic view illustrating an outline configuration and operation of a drive unit according to Comparative Example 2. 
         FIG. 7  is a schematic plan view illustrating outline configurations of drive units according to Modifications 1 and 2. 
         FIG. 8  is a schematic view illustrating an outline configuration and operation of a piezoelectric device that functions as an actuator device according to Modification 3. 
         FIG. 9  is a schematic view illustrating an outline configuration and operation of a bimetal device that functions as an actuator device according to Modification 4. 
         FIG. 10  is a perspective view illustrating a configuration example of an electronic apparatus including an image pickup unit according to Application Example 1 of the drive unit of any of the embodiment and the modifications. 
         FIG. 11  is a perspective view illustrating the electronic apparatus shown in  FIG. 10  from a different direction. 
         FIG. 12  is a perspective view illustrating a main part configuration of the image pickup unit shown in  FIG. 11 . 
         FIG. 13  is an exploded perspective view illustrating a lens module shown in  FIG. 12 . 
         FIG. 14  is a schematic view illustrating a side-face configuration and a planar configuration of the lens module shown in  FIG. 12 . 
         FIG. 15  is a cross-sectional view illustrating a detailed configuration of part of actuator devices (polymer actuator devices), fixing members, and fixed electrodes shown in  FIG. 13 . 
         FIG. 12  is a side-face schematic view illustrating operation of the lens module shown in  FIG. 12 . 
         FIG. 17  is a schematic view illustrating a side-face configuration and a planar configuration of a lens module according to Modification 3. 
         FIG. 18  is a schematic view illustrating a side-face configuration and a planar configuration of a lens module according to Application Example 2. 
         FIG. 19  is a perspective view illustrating a method of manufacturing a drive unit in the lens module shown in  FIG. 18  in process order. 
         FIG. 20  is a perspective view, a plan view, and a side-face view each illustrating a process following a process shown in  FIG. 19 . 
     
    
    
     MODE(S) FOR CARRYING OUT THE INVENTION 
     An embodiment of the present invention will be described in detail below with reference to the drawings. Description will be given in the following order.
     1. Embodiment (an example using a polymer actuator device as an actuator device)   2. Modifications   

     Modifications 1 and 2 (examples in which a reinforcing layer has a wide-width portion and a narrow-width portion) 
     Modification 3 (an example using a piezoelectric device as the actuator device) 
     Modification 4 (an example using a bimetal device as the actuator device)
     3. Application Examples 1 and 2 (examples in which a drive unit is applied to a lens module and to an image pickup unit)   

     Embodiment 
     [General Configuration of Drive Unit  1 ] 
       FIG. 1  schematically illustrates an outline configuration of a drive unit (drive unit  1 ) according to an embodiment of the present invention in a plan view (an X-Y plane view, a top view). Further, Part (A) of  FIG. 2  schematically illustrates a side-face configuration (Z-X side-face configuration) of the drive unit  1 . Part (B) of  FIG. 2  illustrates an enlarged part of Part (A) of  FIG. 2  (vicinity of a region designated by a symbol P 1 ). 
     The drive unit  1  is a cantilever actuator that drives (along a Z axis in this example) a driving target  9 . The drive unit  1  includes a supporting member  11 , a fixing member  12 , an actuator device  13 , a reinforcing layer  18  (reinforcing member), and a voltage supplying section  19 . 
     The supporting member  11  is a base member (base) that supports the drive unit  1  as a whole. The supporting member  11  is so arranged as to extend on an XY plane in this example. The supporting member  11  may be formed, for example, of a hard resin material such as a liquid crystal polymer. 
     The fixing member  12  is a member that fixes a first end portion (fixed portion) of the actuator device  13  and stands on the supporting member  11  in a Z-axis direction. The fixing member  12  may also be formed, for example, of a hard resin material such as a liquid crystal polymer. 
     The actuator device  13  is a device that drives the driving target  9  along the Z axis. The actuator device  13  is configured of a flat-plate-like (thin-plate-like) polymer actuator device in this example. In the actuator device  13 , a length from the first end (closer to the fixing member  12 ) to the second end (closer to the driving target  9 , closer to the movable portion) is L 1 . Further, concerning a width of the actuator device  13 , a width W 11  of a portion closer to the fixing member  12  is larger than a width W 12  of a portion closer to the driving target  9  in this example (W 11 &gt;W 12 ). In other words, the actuator device  13  has a wide-width portion closer to the fixing member  12  and has a narrow-width portion closer to the driving target  9 . It is to be noted that description will be given later of a detailed configuration of the actuator device  13  configured of the polymer actuator device ( FIG. 3 ). 
     The reinforcing layer  18  is a member that reinforces strength (mechanical strength) of the actuator device  13  by being provided on part or all of the actuator device  13 . The reinforcing layer  18  is provided on both a front face and a back face (a pair of main surfaces) of the actuator device  13  in this example. However, the reinforcing layer  18  may be provided on one of the front and back faces of the actuator device  13 . It is preferable that the above-described reinforcing layer  18  be provided, for example, on part or all of the above-described narrow-width portion (portion with the width W 12 ) of the actuator device  13 . One reason for this is that the narrow-width portion of the actuator device  13  contributes relatively a little to displacement (deformation) of the device as will be described later. The reinforcing layer  18  is provided not only on the narrow-width portion of the actuator device  13  but also on part or all of the above-described wide-width portion (portion with the width W 11 ) in this example. Specifically, the reinforcing layer  18  is continuously (integrally) provided from the narrow-width portion over the wide-width portion of the actuator device  13 . The above-described reinforcing layer  18  may be formed, for example, of a resin material such as polyimide (PI) and polyethylene naphthalate (PEN). 
     The voltage supplying section  19  supplies a drive voltage Vd to the actuator device  13 , and thereby drives (deforms) the actuator device  13 . The foregoing voltage supplying section  19  may include, for example, an electric circuit that uses a component such as a semiconductor device. It is to be noted that description will be given later of the detailed operation of the voltage supplying section  19  driving the actuator device  13  (polymer actuator device) ( FIG. 4 ). 
     [Detailed Configuration of Actuator Device  13 ] 
     Next, description will be given of a detailed configuration of the actuator device  13  configured of the polymer actuator device with reference to  FIG. 3 .  FIG. 3  illustrates a cross-sectional configuration (Z-X cross-section configuration) of the actuator device  13 . 
     The actuator device  13  has a cross-sectional structure in which a pair of electrode films  52 A and  52 B are formed on both faces of an ion conductive polymer compound film  51  (hereinafter, simply referred to as “polymer compound film  51 ”). In other words, the actuator device  13  includes the pair of electrode films  52 A and  52 B and the polymer compound film  51  inserted between the electrode films  52 A and  52 B. It is to be noted that circumference of the actuator device  13  and of the electrode films  52 A and  52 B may be covered with an insulating protection film formed of a material with high elasticity (such as polyurethane). 
     The polymer compound film  51  curves in response to generation of a predetermined potential difference between the electrode films  52 A and  52 B. The polymer compound film  51  is impregnated with an ionic substance. “Ionic substance” herein refers to general ions that are movable inside the polymer compound film  51 . Specifically, “ionic substance” herein refers to substances including a polar solvent and, for example, a hydrogen ion, a simple substance of a metal ion, or a cation and/or an anion thereof, and refers to substances including a cation and/or an anion being liquid itself such as imidazolium salt. Examples of the former include substances in which a polar solvent is solvated in a cation and/or an anion. Examples of the latter include ionic liquid. 
     Examples of a material configuring the polymer compound film  51  includes an ion-exchange resin that includes, for example, a fluorine resin or a hydrocarbon system as a skeleton thereof. As the ion-exchange resin, a cation-exchange resin is preferable when the polymer compound film  51  is impregnated with a cationic substance, and an anion-exchange resin is preferable when the polymer compound film  51  is impregnated with an anionic substance. 
     Examples of the anion-exchange resin include a resin to which an acid group such as a sulfonic acid group and a carboxyl group is introduced, in particular, polyethylene including an acid group, polystyrene including an acid group, and a fluorine resin including an acid group. In particular, a fluorine resin that includes a sulfonic acid group or a carboxyl group is preferable as the cation-exchange resin, for example, Nafion (available from E. I. du Pont de Nemours and Company). 
     The cationic substance that impregnates the polymer compound film  51  may be any kind, for example, may be organic or inorganic. Various materials may be used, for example, a simple substance of a metal ion, a substance including a metal ion and water, a substance including an organic cation and water, ionic liquid, etc. Examples of the metal ion include light-metal ions such as a sodium ion (Na + ), a potassium ion (K + ), a lithium ion (Li + ), and a magnesium ion (Mg 2+ ). Moreover, examples of the organic cation include an alkyl ammonium ion. The foregoing cations exist as hydrates in the polymer compound film  51 . Therefore, it is preferable that the cationic substance be sealed as a whole so as to suppress volatilization of water in the actuator device  13  when the polymer compound film  51  is impregnated with a cationic substance including a cation and water. 
     The ion liquid may be a so-called ambient-temperature molten salt and includes a cation and an anion that have low burnability and low volatility. Examples of the ionic liquid include imidazolium-ring-based compounds, pirydinium-ring-based compounds, and aliphatic compounds. 
     In particular, the cationic substance preferably is ionic liquid since ionic liquid has low volatility, and therefore, the actuator device  13  operates favorably even under high temperature atmosphere or in a vacuum. 
     The electrode films  52 A and  52 B that face each other with the polymer compound film  51  in between each include one or more conductive materials. The electrode films  52 A and  52 B are each preferably formed of conductive material powders bound together by an ion conductive polymer since this increases flexibility of the electrode films  52 A and  52 B. The conductive material powders are preferably carbon powders. One reason for this is that a larger amount of deformation is obtainable since carbon powders have high conductivity and large specific surface area. Ketjen black is preferable as the carbon powders. Materials similar to those configuring the polymer compound film  51  described above are preferable as the ion conductive polymer. 
     The electrode films  52 A and  52 B may be formed as follows, for example. That is, paint in which the conductive material powders and an ion conductive polymer are dispersed in a dispersion medium is applied to both faces of the polymer compound film  51  and is dried. Also, a film-like component including the conductive material powders and the ion conductive polymer may be crimped onto the both faces of the polymer compound film  51 . 
     The electrode films  52 A and  52 B each may have a multi-layer structure. In this case, it is preferable that the electrode films  52 A and  52 B each have a structure in which a layer including the conductive material powders bound by the ion conductive polymer and a metal layer are laminated in order from the polymer compound film  51 . This allows a potential to be closer to a uniform value in an in-plane direction of the electrode films  52 A and  52 B, and thereby, further superior deformation performance is obtained. Examples of a material configuring the metal layer include noble metal such as gold and platinum. The metal layer may have any thickness. However, the metal film is preferably a continuous film so that a potential is uniform in the electrode films  52 A and  52 B. Examples of a method of forming the metal film include plating, deposition, and sputtering. 
     Dimensions (width and length) of the polymer compound film  51  may be appropriately set depending on factors such as the dimensions and weight of the driving target  9  and displacement amount (deformation amount) necessary in the polymer compound film  51 . The displacement amount of the polymer compound film  51  may be set, for example, depending on the necessary displacement amount (moving amount along the Z-axis direction) of the driving target  9 . 
     [Method of Manufacturing Drive Unit  1 ] 
     The drive unit  1  of the present embodiment may be manufactured as follows, for example. That is, first, the actuator device  13  is formed. Specifically, the actuator device  13  configured of the polymer actuator device with the above-described structure is formed in this example. 
     Next, the reinforcing layer  18  configured of the foregoing material is formed on part or all of the actuator device  13  by attaching the reinforcing layer  18  thereto, for example, with use of an adhesive agent or the like. 
     Subsequently, the first end portion of the actuator device  13  is fixed by the fixing member  12  that stands on the supporting member  11 . Further, a predetermined circuit (such as a semiconductor chip) configuring the voltage supplying section  19  is also attached. Thus, the drive unit  1  shown in  FIGS. 1 and 2  is completed. 
     [Functions and Effects of Drive Unit  1 ] 
     Subsequently, description will be given of functions and effects of the drive unit  1  of the present embodiment. 
     [1. Operation of Actuator Device  13 ] 
     First, description will be given of operation of the actuator device  13  configured of the polymer actuator device with reference to  FIG. 4 .  FIG. 4  schematically illustrates the operation of the actuator device  13  in a cross-sectional view. 
     First, a case of using a substance including a cation and a polar solvent as the cationic substance will be described. 
     In this case, the actuator device  13  without voltage application does not curve and has a planar shape since the cationic substances are dispersed almost uniformly in the polymer compound film  51  (Part (A) of  FIG. 4 ). Here, when the voltage supplying section  19  in Part (B) of  FIG. 4  applies a voltage (begins application of a drive voltage Vd), the actuator device  13  behaves as follows. That is, for example, when a predetermined drive voltage Vd is applied between the electrode films  52 A and  52 B so that the electrode film  52 A has a minus potential and the electrode film  52 B has a plus potential, the cation moves toward the electrode film  52 A with being solvated with the polar solvent. At this time, the anion is hardly movable in the polymer compound film  51 . Therefore, the electrode film  52 A side of the polymer compound film  51  is swollen and the electrode film  52 B side thereof is contracted. Accordingly, the actuator  13  as a whole curves toward the electrode film  52 B as shown in Part (B) of  FIG. 4 . Thereafter, when a potential difference between the electrode films  52 A and  52 B is eliminated to make a non-voltage application state (stop application of the drive voltage Vd), the cationic substance (the cation and the polar solvent) that has been tilted toward the electrode film  52 A in the polymer compound film  51  is diffused and returns to the state shown in Part (A) of  FIG. 4 . Moreover, when a predetermined drive voltage Vd is applied between the electrode films  52 A and  52 B in the non-voltage application state shown in Part (A) of  FIG. 4  so that the electrode film  52 A has a plus potential and the electrode film  52 B has a minus potential, the cation moves toward the electrode film  52 B with being solvated with the polar solvent. In this case, the electrode film  52 A side of the polymer compound film  51  is contracted and the electrode film  52 B side thereof is swollen. Therefore, the actuator device  13  as a whole curves toward the electrode film  52 A. 
     Subsequently, a case of using ionic liquid including liquid cation as the cationic substance will be described. 
     Also in this case, the actuator device  13  without voltage application has the planar shape shown in Part (A) of  FIG. 4  since the ionic liquid is dispersed almost uniformly in the polymer compound film  51 . Here, when the voltage supplying section  19  applies a voltage (begins application of a drive voltage Vd), the actuator device  13  behaves as follows. That is, for example, when a predetermined drive voltage Vd is applied between the electrode films  52 A and  52 B so that the electrode film  52 A has a minus potential and the electrode film  52 B has a plus potential, a cation in the ionic liquid moves toward the electrode film  52 A. However, the anion is not movable in the polymer compound film  51  which is a cation-exchange film. Therefore, the electrode film  52 A side of the polymer compound film  51  is swollen and the electrode film  52 B side thereof is contracted. Accordingly, the actuator  13  as a whole curves toward the electrode film  52 B as shown in Part (B) of  FIG. 4 . Thereafter, when a potential difference between the electrode films  52 A and  52 B is eliminated to make a non-voltage application state (stop application of the drive voltage Vd), the cation that has been tilted toward the electrode film  52 A in the polymer compound film  51  is diffused and returns to the state shown in Part (A) of  FIG. 4 . Moreover, when a predetermined drive voltage Vd is applied between the electrode films  52 A and  52 B in the non-voltage application state shown in Part (A) of  FIG. 4  so that the electrode film  52 A has a plus potential and the electrode film  52 B has a minus potential, the cation in the ionic liquid moves toward the electrode film  52 B. In this case, the electrode film  52 A side of the polymer compound film  51  is contracted and the electrode film  52 B side thereof is swollen. Therefore, the actuator device  13  as a whole curves toward the electrode film  52 A. 
     [2. Operation of Drive Unit  1 ] 
     In the drive unit  1 , the driving target  9  is driven in accordance with the above-described deformation (curve) of the actuator device  13 . Accordingly, the driving target  9  becomes movable (displaceable) along the Z axis as shown by an arrow in Part (A) of  FIG. 2 . 
     Here, functions and effects of the feature part of the drive unit  1  will be described in detail in comparison with comparative examples.  FIG. 5  schematically illustrates an outline configuration and operation of a drive unit (drive unit  101 ) according to Comparative Example 1. Part (A) shows a planar configuration (X-Y plane configuration, top configuration) thereof and Part (B) shows a side-face configuration (Z-X side-face configuration) thereof. Further,  FIG. 6  schematically illustrates an outline configuration and operation of a drive unit (drive unit  201 ) according to Comparative Example 2. Part (A) shows a planar configuration (X-Y plane configuration, top configuration) thereof and Part (B) shows a side-face configuration (Z-X side-face configuration) thereof. 
     Comparative Example 1  
     First, the drive unit  101  of Comparative Example 1 shown in  FIG. 5  does not include the reinforcing layer  18 , unlike the drive unit  1  of the present embodiment. Further, in the drive unit  101 , an actuator device  103  has a width W 101  that is uniform (the same) from a portion closer to the fixing member  12  over a portion closer to the driving target  9 . In other words, the width W 101  of the actuator device  103  as a whole is larger than the width (in particular, the width W 12  of the narrow-width portion) of the actuator device  13  of the present embodiment (W 101 &gt;W 12 ). 
     In such a cantilever actuator, it is preferable to allow a width of the cantilever to be as small as possible, for example, in a view of freedom in design (size reduction in structure). However, in the drive unit  101  of Comparative Example 1, it is difficult to reduce the size of the structure (to improve freedom in design) of the drive unit  101  as a whole since the width W 101  of the actuator device  103  is large (wide). 
     Comparative Example 2  
     On the other hand, in the drive unit  202  of Comparative Example 2 shown in  FIG. 6 , the actuator device  13  includes a wide-width portion (with the width W 11 ) closer to the fixing member  12  and includes a narrow-width portion (with the width W 12 ) closer to the driving target  9  as in the drive unit  1  of the present embodiment. Therefore, size reduction in the structure (to improve freedom in design) of the drive unit  201  as a whole is allowed, compared to the above-described drive unit  101  of Comparative Example 1. 
     However, the drive unit  201  of Comparative Example 2 does not include the reinforcing layer  18 , unlike the drive unit  1  of the present embodiment. Therefore, it is difficult to secure strength (mechanical strength) of the actuator device  13  due to the small width (width W 12 ) of the cantilever. Therefore, there may be a case in which the actuator device  13  does not sufficiently drive (displace in a positive direction (upward direction) of the Z axis, in this example) the driving target  9  as shown in Part (B) of  FIG. 6 , for example. In other words, it is necessary to provide the actuator device  13  with sufficient strength (mechanical strength) to support the driving target  9  by securing a certain width since it is necessary to support the driving target  9  by the cantilever. 
     As described above, it is difficult to reduce size (improve freedom in design) while maintaining (favorable) drive characteristics in the above-described drive units  101  and  201  of Comparative Examples 1 and 2. 
     On the other hand, in the drive unit  1  of the present embodiment, the reinforcing layer  18  is provided on part or all of the actuator device  13  as shown in  FIGS. 1 and 2 . Therefore, mechanical strength of the actuator device  13  is secured even when the width thereof (in particular, the width W 12  of the narrow-width portion) is narrowed. 
     Moreover, it can be said as follows concerning a location to provide the reinforcing layer  18  in the drive unit  1  of the present embodiment. That is, first, in the actuator device  13 , the fixed portion (see a region shown by the symbol P 11  in Part (A) of  FIG. 2 ) has larger curvature than the movable portion (see a region shown by the symbol P 12  in Part (A) of  FIG. 2 ) at the time of deformation. Further, in view of displacement enlarging effect due to the length of the beam, the fixed portion contributes more to displacement at a tip (vicinity of the driving target  9 ) of the actuator device  13  compared to the movable portion. Therefore, it is the fixed portion that largely contributes to displacement (deformation) of the actuator device  13 , and a portion (such as the vicinity of P 12 ) that contributes to the displacement relatively a little has small influence on the displacement amount of the driving target  9  even if the portion is restrained by the reinforcing layer  18 . On the other hand, generative force of the actuator device  13  increases in accordance with (substantially in proportion to) increasing width (the width W 11  of the wide-width portion in this example) of the fixed portion when rigidity (flexural rigidity) of the cantilever actuator is sufficiently secured. As can be said from the above, it is preferable to provide the reinforcing layer  18 , for example, on a middle portion (the vicinity of P 12 ) or on the tip of the cantilever with allowing the width W 11  of the fixed portion (wide-width portion) of the actuator device  13  to be sufficiently large. One reason is that this allows setting the width W 12  of the portion (narrow-width portion) other than the fixed portion to be dramatically small while sufficiently securing mechanical strength of the actuator device  13 . 
     As described above, the reinforcing layer  18  is provided on part or all of the actuator device  13  in the present embodiment. Therefore, mechanical strength of the actuator device  13  is secured while setting the width (in particular, the width W 12  of the narrow-width portion) thereof to be narrow. Therefore, size reduction is achievable while maintaining drive characteristics and freedom in design is improved. 
     Moreover, the polymer actuator device is used in particular as the actuator device  13 . Therefore, the following advantages are obtainable compared to a case of using an actuator device of other scheme (such as a piezoelectric device and a bimetal device described later). That is, the drive voltage Vd is suppressed to be low, and therefore, electric power consumption is reduced. Also, low-cost manufacturing is achieved. 
     Modifications 
     Subsequently, modifications (Modifications 1 to 4) of the above-described embodiment will be described. It is to be noted that components same as those in the embodiment are designated by the same numerals and description thereof will be appropriately omitted. 
     Modifications 1 and 2 
     Part (A) of  FIG. 7  schematically illustrates an outline configuration of a drive unit (drive unit  1 A) according to Modification 1 in a plan view (X-Y plane view, top view). Further, Part (B) of  FIG. 7  schematically illustrates an outline configuration of a drive unit (drive unit  1 B) according to Modification 2 in a plan view (X-Y plane view, top view). 
     The drive unit  1 A of Modification 1 shown in Part (A) of  FIG. 7  includes an actuator device  13 A and a reinforcing layer  18 A instead of the actuator device  13  and the reinforcing layer  18 , respectively, in the drive unit  1  of the above-described embodiment. Other configurations of the drive unit  1 A are similar to those of the drive unit  1  of the above-described embodiment. 
     The actuator device  13 A includes a wide-width portion (with the width W 11 ) closer to the fixing member  12  and a narrow-width portion (with the width W 12 ) closer to the driving target  9 , as the actuator device  13  of the above-described embodiment. Further, the reinforcing layer  18 A has a shape with a width in accordance with the narrow-width portion and the wide-width portion of the actuator device  13 A. In other words, the reinforcing layer  18 A also has a wide-width portion  18 A 1  closer to the fixing member  12  and includes a narrow-width portion  18 A 2  closer to the driving target  9 . It is to be noted that the planar shape of the wide-width portion  18 A 1  is rectangular in this example. 
     On the other hand, the drive unit  1 B of Modification 2 shown in Part (B) of  FIG. 7  includes an actuator device  13 B and a reinforcing layer  18 B instead of the actuator device  13  and the reinforcing layer  18 , respectively, in the drive unit  1  of the above-described embodiment. Other configurations of the drive unit  1 B are similar to those of the drive unit  1  of the above-described embodiment. 
     The actuator device  13 B includes a wide-width portion (with the width W 11 ) closer to the fixing member  12  and a narrow-width portion (with the width W 12 ) closer to the driving target  9 , as the actuator device  13 . Further, the reinforcing layer  18 B has a shape with a width in accordance with the narrow-width portion and the wide-width portion of the actuator device  13 B. In other words, the reinforcing layer  18 B also has a wide-width portion  18 B 1  closer to the fixing member  12  and includes a narrow-width portion  18 B 2  closer to the driving target  9 . It is to be noted that the planar shape of the wide-width portion  18 B 1  is triangular (a triangular shape with a width gradually narrowed from the portion closer to the fixing member  12  toward the portion closer to the driving target  9 ) in this example. 
     As described above, in the Modifications 1 and 2, the reinforcing layers  18 A and  18 B each have a shape with a width in accordance with the narrow-width portion and the wide-width portion thereof in the actuator devices  13 A and  13 B. Therefore, mechanical strength of the actuator devices  13 A and  13 B are more easily secured even when the driving target  9  is especially heavy. 
     Modification 3 
       FIG. 8  schematically illustrates, in a perspective view, an outline configuration and operation of an actuator device (actuator device  13 C) applied to a drive unit according to Modification 3. The drive unit of the present modification includes the actuator device  13 C configured of a piezoelectric device which will be described below, instead of the actuator device  13  configured of the polymer actuator device described in the above embodiment. 
     The piezoelectric device includes a conductive plate  61  that extends on the X-Y plane, a pair of piezoelectric bodies  62 A and  62 B arranged on both faces of the conductive plate  61 , and a pair of fixing members  63 A and  63 B that fix first end portions of the conductive plate  61  and of the piezoelectric bodies  62 A and  62 B. 
     The conductive plate  61  may be formed, for example, of a material such as phosphor bronze. The piezoelectric bodies  62 A and  62 B each may be formed, for example, of a piezoelectric material such as lead zirconate titanate (PZT). It is to be noted that a predetermined polarization process is performed on each of the piezoelectric bodies  62 A and  62 B along a thickness direction thereof (Z-axis direction) and the piezoelectric bodies  62 A and  62 B have the polarization directions that are directed at the same direction. 
     The actuator device  13 C configured of the piezoelectric device with the above-described configuration operates as follows when a predetermined drive voltage Vd is applied to each of the piezoelectric bodies  62 A and  62 B. That is, one of the piezoelectric bodies (the piezoelectric body  62 A in this example) extends along the X-axis direction, and on the other hand, the other of the piezoelectric bodies (the piezoelectric body  62 B in this example) shrinks along the X-axis direction. As a result, the actuator device  13 C as a whole curves (is flexed) along the thickness direction thereof (Z-axis direction) and generates a deformation amount d in the Z-axis direction. It is to be noted that, when the polarity of the drive voltage Vd is inversed, a deformation amount d in an opposite direction is obtained in accordance thereto. Thus, the piezoelectric device functions as the actuator device by supplying the drive voltage Vd. 
     Therefore, effects similar to those of the above-described embodiment is obtained from functions similar to those of the above-described embodiment also in the drive unit of the present modification that uses the foregoing piezoelectric device as the actuator device  13 C. 
     Modification 4 
       FIG. 9  schematically illustrates, in a side-face view (Z-X side-face view), an outline configuration and operation of the actuator device (actuator device  13 D) applied to a drive unit according to Modification 4. Part (A) illustrates a state before an operation and Part (B) illustrates a state after the operation. The drive unit of the present modification includes an actuator device  13 D configured of a bimetal device described below, instead of the actuator device  13  configured of the polymer actuator device described in the above embodiment. 
     The bimetal device includes a pair of metal plates (a high-expansion metal plate  72 A and a low-expansion metal plate  72 B having different thermal expansion rates) that extend on the XY plane and a pair of fixing members  73 A and  73 B that fix first end portions of the metal plates. The high-expansion metal plate  72 A and the low-expansion metal plate  72 B are attached to each other to form a laminate structure. 
     The high-expansion metal plate  72 A and the low-expansion metal plate  72 B each may be formed, for example, of a material in which metal such as manganese (Mn), chromium (Cr), and copper (Cu) is added to an alloy of iron (Fe) and nickel (Ni). The thermal expansion rates of the high-expansion metal plate  72 A and the low-expansion metal plate  72 B are differentiated by differentiating the amount of the foregoing metal added to the alloy. 
     When the actuator device  13 D configured of the bimetal device with the above-described configuration is brought into a high temperature state compared to the flat state (before-operation state) shown in Part (A) of  FIG. 9 , the high-expansion metal plate  72 A expands more than the low-expansion metal plate  72 B. As a result, the actuator device  13 D as a whole curves (is flexed) along a thickness direction thereof (Z-axis direction) and generates a deformation amount d in the Z-axis direction. Therefore, the bimetal device functions as the actuator device by varying temperature of the high-expansion metal plate  72 A and the low-expansion metal plate  72 B with use of a heating section such as a heater which is not illustrated. 
     Therefore, effects similar to those of the above-described embodiment is obtained from functions similar to those of the above-described embodiment also in the drive unit of the present modification that uses the foregoing bimetal device as the actuator device  13 D. 
     APPLICATION EXAMPLES  
     Subsequently, description will be given of application examples (application examples to a lens module and to an image pickup unit: Application Examples 1 and 2) of the drive units according to the above-described embodiment and Modifications 1 to 4. 
     Application Example 1  
     [Configuration of Mobile Phone  8 ] 
       FIGS. 10 and 11  each illustrate, in a perspective view, an outline configuration of a mobile phone (mobile phone  8 ) with an image pickup function as an example of an electronic apparatus with an image pickup unit according to Application Example 1 of the drive unit of the above-described embodiment and the like. In the mobile phone  8 , two housings  81 A and  81 B are connected to each other through an unillustrated hinge mechanism in a foldable manner. 
     As shown in  FIG. 10 , a plurality of various operation keys  82  are provided on a surface on one side of the housing  81 A and a microphone  83  is provided on the bottom end of the housing  81 A. The operation keys  82  receive predetermined operation by a user and are used to input information. The microphone  83  is used to input voice of the user during phone call etc. 
     As shown in  FIG. 10 , a display section  84  using a liquid crystal display panel etc. is provided on a surface on one side of the housing  81 B and a speaker  85  is provided on the top end of the housing  81 B. The display section  84  may display, for example, various information such as radio wave reception state, remaining amount of battery, a phone number of a person who is on the phone, content stored in a phonebook (phone number, name, etc. of a person), and lists of transmitted call and received call. The speaker  85  outputs voice of the person on the phone etc. during the phone call etc. 
     As shown in  FIG. 11 , a cover glass  86  is provided on a surface on the other side of the housing  81 A and an image pickup unit  2  is provided in the housing  81 A at a position corresponding to that of the cover glass  86 . The image pickup unit  2  includes a lens module  4  according to the present application example that is arranged in a region closer to the object (cover glass  86 ), and includes an image pickup device  3  arranged in a region closer to an image (inside of the housing  81 A). The image pickup device  3  is a device that acquires an image pickup signal resulting from imaging by a lens (later-described lens  40 ) in the lens module  4 . The image pickup device  3  is configured of an image sensor that is provided with, for example, a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), or the like. 
     [Configuration of Image Pickup Unit  2 ] 
       FIG. 12  illustrates, in a perspective view, a main part configuration of the image pickup unit  2 .  FIG. 13  illustrates, in an exploded perspective view, a configuration of the lens module  4  in the image pickup unit  2 . Moreover,  FIG. 14  schematically illustrates an outline configuration of the lens module  4  with a side-face view (Z-X side-face view) in Part (A) and a plan view (X-Y plane view) in Part (B). 
     The lens module  4  includes the supporting member  11 , a reinforcing layer  181 , an actuator device  131 , a lens holding member  14  and a lens  40 , reinforcing layer  182 , and an actuator device  132  along an optical axis Z 1  in order from the image (image pickup device  3 ) toward the object (along the positive direction of the Z axis). It is to be noted that illustration of the lens  40  is omitted in  FIG. 12 . The lens module  4  also includes the fixing member  12 , coupling members  151 A,  151 B,  152 A, and  152 B, fixed electrodes  130 A and  130 B, a steadying member  16 , and hole devices  17 A and  17 B. It is to be noted that the foregoing members of the lens module  4  except for the lens  40  correspond to specific example of “lens drive unit” of the present invention. 
     The supporting member  11  is a base material (base) that supports the lens module  4  as a whole. 
     The fixing member  12  is a member that fixes a first end of each of the actuator devices  131  and  132  in this example. The fixing member  12  includes three members, i.e., a lower fixing member  12 D, a central (middle) fixing member  12 C, and an upper fixing member  12 U that are arranged from the image (bottom parts in  FIGS. 12 and 13 ) toward the object (upper parts in  FIGS. 12 and 13 ). The first end of the actuator device  131  and first ends of the fixed electrodes  130 A and  130 B are interposed between the lower fixing member  12 D and the central fixing member  12 C. On the other hand, the first end of the actuator device  132  and second ends of the fixed electrodes  130 A and  130 B are interposed between the central fixing member  12 C and the upper fixing electrode  12 U. Further, an opening  12 C 0  that allows a part of the lens holding member  14  (a part of a holding portion  14 B described later) to be partially inserted therethrough is formed in the central fixing member  12 C of the foregoing. This allows part of the lens holding member  14  to move inside the opening  12 C 0 . Therefore, space is effectively utilized and the size of the lens module  4  is reduced. 
     The fixed electrodes  130 A and  130 B are electrodes that supply the drive voltage Vd received from the foregoing voltage supplying section  19  to the electrode films (the foregoing electrode films  52 A and  52 B) in the actuator devices  131  and  132 . The fixed electrodes  130 A and  130 B may be formed, for example, of gold (Au), metal plated with gold, etc. and has a U-like shape. Therefore, the fixed electrodes  130 A and  130 B each sandwich top and bottom of the central fixing member  12 C (both side faces along the Z axis) and is allowed to apply the same voltage in parallel to the pair of actuator devices  131  and  132  with small number of wirings. Further, degradation in contact resistance due to a factor such as surface oxidation is prevented when the fixed electrodes  130 A and  130 B are configured of a metal material plated with gold. 
     The lens holding member  14  is a member that holds the lens  40 . The lens holding member  14  may be formed, for example, of a hard resin material such as liquid crystal polymer. The lens holding member  14  is so arranged that the center thereof is on the optical axis Z 1 . The lens holding member  14  includes the circular holding portion  14 B that holds the lens  40 , and includes a connection portion  14 A that supports the holding portion  14 B and connects the holding portion  14 B to the later-described coupling members  151 A,  151 B,  152 A, and  152 B. Moreover, the holding portion  14 B is arranged between later-described driving faces of the pair of actuator devices  131  and  132 . 
     The actuator devices  131  and  132  each have a driving face (a driving face on the X-Y plane) that is perpendicular to the optical axis Z 1  of the lens  40 . The actuator devices  131  and  132  are so arranged that the driving faces face each other along the optical axis Z 1 . The actuator devices  131  and  132  each drive the lens holding member  14  (and the lens  40 ) along the optical axis Z 1  through the later-described coupling members  151 A,  151 B,  152 A, and  152 B. Further, the actuator devices  131  and  132  are each configured of the foregoing polymer actuator device in this example. The actuator devices  131  and  132  includes a wide-width portion (with a width W 21 ) closer to the fixing member  12  and a narrow-width portion (with a width W 22 ) in a movable portion (closer to the coupling members  151 A,  151 B,  152 A, and  152 B) in this example as shown in Part (B) of  FIG. 14 . 
     Here, as shown in a cross-sectional view (Z-X cross-section view) in  FIG. 15 , in the actuator device  131 , the electrode film  52 A is electrically connected to the fixed electrode  130 B on the lower fixing member  12 D side thereof and the electrode film  52 B is electrically connected to the fixed electrode  130 A on the central fixing member  12 C side thereof. On the other hand, in the actuator device  132 , the electrode film  52 A is electrically connected to the fixed electrode  130 A on the central fixing member  12 C side thereof, and the electrode film  52 B is electrically connected to the fixed electrode  130 B on the upper fixing member  12 U side thereof. It is to be noted that, although not illustrated in  FIG. 15 , each of the members and the electrodes from the fixed electrode  130 B closer to the lower fixing member  12 D to the fixed electrode  130 B closer to the upper fixing member  12 U is sandwiched and fixed by the steadying member  16  (plate spring) shown in  FIG. 13  with a certain pressure. Accordingly, the actuator devices  131  and  132  are not destroyed even when a large force is applied thereto and stable electric connection is allowed even when the actuator devices  131  and  132  are deformed. 
     The reinforcing layers  181  and  182  each correspond to the reinforcing layer  18  described in the above embodiment and are selectively provided on one face (back face) of the flat-plate-like actuator devices  131  and  132  in this example. However, the above-described reinforcing layers  181  and  182  may be provided on both faces (front face and back face) of the actuator devices  131  and  132 . 
     The coupling members  151 A,  151 B,  152 A, and  152 B are each a member that couples (connects) an end of the connection portion  14 A and second ends of the respective actuator devices  131  and  132 . Specifically, the coupling members  151 A and  151 B each couple a lower end of the connection portion  14 A and the second end of the actuator device  131 . The coupling members  152 A and  152 B each couple an upper end of the connection portion  14 A and the second end of the actuator device  132 . The coupling members  151 A,  151 B,  152 A, and  152 B each may be formed, for example, of a flexible film such as a polyimide film and is preferably formed of a flexible material that has rigidity (flexural rigidity) almost equal to or less than (preferably, equal to or less than) that of the respective actuator device  131  and  132 . Accordingly, freedom of the coupling members  151 A,  151 B,  152 A, and  152 B of curving in a direction opposite to a curving direction of the actuator devices  131  and  132  is provided. Therefore, a cross-sectional shape of the cantilever configured of the actuator devices  131  and  132  and the coupling members  151 A,  151 B,  152 A, and  152 B has an S-like curved line. As a result, the connection portion  14 A is allowed to travel in parallel along the Z-axis direction and the holding portion  14 B (and the lens  40 ) is driven in the Z-axis direction with maintaining a parallel state with respect to the supporting member  11 . It is to be noted that, for example, a spring constant may be used as the above-described rigidity (flexural rigidity). 
     Here, it is preferable that the following expression (1) is satisfied where S 1  is rigidity (flexural rigidity) of the actuator devices  131  and  132 , and S 2  is rigidity (flexural rigidity) of the reinforcing layers  181  and  182 . This allows the widths of the actuator devices  131  and  132  to be set smaller and the size of the lens module  4  to be smaller. Further, it is more preferable that the following expressions (2) and (3) are both satisfied in addition to the expression (1) where S 3  is rigidity (flexural rigidity) of the coupling members  151 A,  151 B,  152 A, and  152 B. This allows the widths of the actuator devices  131  and  132  to be set further smaller and the size of the lens module  4  to be further smaller. 
       S2&gt;S1   (1)
 
       S2&gt;S3   (2)
 
       S1&gt;S3   (3)
 
     [Functions and Effects of Lens Module  4 ] 
       FIG. 16  illustrates, in a perspective view, operation of the lens module  4 . Part (A) illustrates a state before an operation and Part (B) illustrates a state after the operation. 
     In the lens module  4 , as shown in Parts (A) and (B) of  FIG. 16  (an arrow in the drawing), the pair of actuator devices  131  and  132  drive the lens holding member  14 , and thereby, the lens  40  is allowed to travel along the optical axis Z 1  thereof. Thus, the lens  40  is driven along the optical axis Z 1  thereof by the drive unit (lens drive unit) that uses the actuator devices  131  and  132 , in the lens module  4 . 
     Here, the reinforcing layers  181  and  182  are provided on part or all of the actuator devices  131  and  132  also in the present application example in a manner similar to that of the above-described embodiment. Therefore, mechanical strength of the actuator devices  131  and  132  is secured even when the widths (in particular, the width W 22  of the narrow-width portion) of the actuator devices  131  and  132  are narrowed as shown in Part (B) of  FIG. 14 . Accordingly, the area of the actuator devices  131  and  132  is reduced, and therefore, an optical device with larger diameter (the lens  40  with a large diameter R 1  in this example) is allowed to be provided in the lens module  4 . 
     On the other hand, in a lens module (lens module  304 ) according to Comparative Example 3 shown in Parts (A) and (B) of  FIG. 17 , the reinforcing layer as in the present application example is not provided. Therefore, an area of an actuator device  302  is large. Specifically, the wide-width portion (with a width W 301 ) closer to the fixing member  12  and the narrow-width portion (with a width W 302 ) in a movable portion (closer to the coupling members  151 A,  151 B,  152 A, and  152 B) are larger than the widths W 21  and W 22  of the actuator devices  131  and  132 . Therefore, a diameter of the optical device (a diameter R 301  of a lens  340  in this example) is smaller in the lens module  304  according to Comparative Example 3 compared to in the lens module  4  of the present application example (R 1 &gt;R 301 ). In other words, it is difficult to provide an optical device with a large diameter in the lens module  304  in Comparative Example 3. 
     Application Example 2  
     [Configuration of Lens Module  4 A] 
       FIG. 18  schematically illustrates an outline configuration of a lens module  4 A according to Application Example 2 in a side-face view (Z-X side-face view) in Part (A) and in a plan view (X-Y plane view) in Part (B). The lens module  4 A of the present application example includes reinforcing layers  181 A,  181 B,  182 A, and  182 B instead of the reinforcing layers  181  and  182  in the lens module  4  of the above-described Application Example 1. Moreover, in the lens module  4 A, a length of the coupling members  151 A,  151 B,  152 A, and  152 B in the X-axis direction is set to be longer than the length (length in the X-axis direction) of the beam of the actuator devices  131  and  132 , unlike in the above-described Application Example 1. 
     The reinforcing layers  181 A,  181 B,  182 A, and  182 B correspond to the reinforcing layer  18  described in the above embodiment and are provided on both surfaces (front and back faces) of the flat-plate-like actuator devices  131  and  132  in this example. 
     [Method of Manufacturing Lens Drive Unit in Lens Module  4 A] 
     Lens drive unit part (the actuator devices  131  and  132 , the coupling members  151 A,  151 B,  152 A, and  152 B, and the reinforcing layers  181 A,  181 B,  182 A, and  182 B) out of those in the lens module  4 A of the present application example, in particular, may be manufactured as follows.  FIGS. 19 and 20  illustrate an example of processes of manufacturing the lens drive unit part in perspective views, a plan view (X-Y plane view), and a side-face view (Z-X side-face view). 
     First, as shown in Part (A) of  FIG. 19 , an actuator device  130  configuring the actuator devices  131  and  132  and a low-rigidity layer  150  (for example, a layer formed of the foregoing materials exhibiting rigidity S 3 ) configuring the coupling members  151 A,  151 B,  152 A, and  152 B are arranged with a predetermined space. 
     Subsequently, as shown in Part (B) of  FIG. 19 , a high-rigidity layer  180 A (for example, a layer formed of the foregoing materials exhibiting rigidity S 2 ) configuring the reinforcing layers  181 A and  182 A is attached on one surface (front face) of the actuator device  130  and the low-rigidity layer  150  with use of, for example, an adhesive agent or the like. Subsequently, as shown in Part (C) of  FIG. 19 , a high-rigidity layer  180 B (for example, a layer made of the foregoing materials exhibiting rigidity S 2 ) configuring the reinforcing layers  181 B and  182 B is attached on the other surface (back face) of the actuator device  130  and the low-rigidity layer  150  with use of, for example, an adhesive agent or the like in a similar manner. Thus, the high-rigidity layers  180 A and  180 B configuring the reinforcing layer are formed on the actuator device  130 . 
     Thereafter, a region shown by a dashed line in Part (A) of  FIG. 20  is mechanically cut out, for example, by a process using, for example, a punch, a laser beam, or the like. In other words, the actuator device  130 , the low-rigidity layer  150 , and the high-rigidity layers  180 A and  180 B are cut out in a predetermined shape. Accordingly, the lens drive unit in the lens module  4 A shown in  FIG. 18  is completed as shown in Part (B) of  FIG. 20 . 
     Effects similar to those of the above-described Application Example 1 is obtained from functions similar to those of the above-described Application Example 1 also in the lens module  4 A of the present application example with the above-described configuration. In other words, the area of the actuator devices  131  and  132  is reduced, and therefore, an optical device with a larger diameter (the lens  40  with a large diameter R 1 ) is allowed to be provided in the lens module  4 A. 
     Other Modifications 
     The present invention has been described hereinabove with referring to the embodiment, the modifications, and the application examples as examples. However, the present invention is not limited to the above-described embodiments and the like and may be variously modified. 
     For example, the connection portion  14 A and the coupling members  151 A,  151 B,  152 A, and  152 B that are described in the above embodiment and the like may not be provided in some cases. Moreover, description has been given in the above embodiment and the like of a case in which the first end portion of the actuator device is directly fixed by the fixing member; however, this is not limitative. In other words, the first end portion of the actuator device may be indirectly (through a component such as a fixed electrode) fixed by the fixing member. 
     Moreover, description has been mainly given in the above embodiment and the like of a case in which a pair of actuator devices are provided. However, the actuator devices are not necessarily one pair, and one, or three or more actuator devices may be provided. 
     Moreover, the shape of each actuator device is not limited to those described in the above embodiment and the like. The laminate configuration of each actuator device is also not limited to those described in the above embodiment and the like and may be appropriately changed. Moreover, for example, a shape, a material, etc. of each member in the lens module (drive unit) are not limited to those described in the above embodiment and the like. For example, the shape of the reinforcing member is not limited to the shapes (such as a layered structure (reinforcing layer)) described in the above embodiment and the like, and may be other shapes. 
     In addition, the lens drive unit that drives the lens along the optical axis thereof has been described as an example of the drive unit of the present invention in the above embodiment and the like. However, it is not limited to the case, and the lens drive unit may drive the lens along a direction perpendicular to the optical axis thereof, for example. Moreover, the drive unit of the present invention is applicable to those other than the above-described lens drive unit, such as a drive unit that drives an aperture etc. (see Japanese Unexamined Patent Application Publication No. 2008-259381 etc.). Moreover, the drive unit, the lens module, and the image pickup unit of the present invention are applicable to various electronic apparatuses other than the mobile phone described in the above embodiment and the like.