JP2010074502A - Drive unit and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of driving a lens layer manufactured at a wafer level. <P>SOLUTION: A drive unit includes: a lens layer 16 which is manufactured at a wafer level and is driven relative to a fixed part; a first actuator layer 15 having a first displacement part that displaces relative to the fixed part; and a second actuator layer 17 having a second displacement part that displaces relative to the fixed part. A body to be driven is sandwiched between the first display part and the second display part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a driving technique for driving a lens.

  2. Description of the Related Art In recent years, small electronic devices (for example, mobile phones) to which a photographing function is added by mounting a micro camera unit (MCU) are rapidly spreading. Accordingly, further miniaturization of the camera module used as the MCU is desired.

  In a conventional camera module, a lens barrel and a lens holder that support a lens, a holder that supports an infrared (IR) cut filter, a substrate, and a casing that holds a laminate including an imaging element and an optical element, such a stack Resins that seal the body are required. For this reason, it has been difficult to produce a camera module by miniaturizing a large number of components and combining the components with high accuracy.

  With respect to such a problem, in Patent Document 1, a laminated member in which a substrate, a semiconductor sheet on which a large number of imaging elements are formed, and a lens array sheet on which a large number of imaging lenses are formed are attached via a resin layer. A technique for forming individual camera modules by dicing the laminated member is proposed.

JP 2007-12995 A

  However, in the technique described in Patent Document 1, a camera module is formed by laminating functional layers such as a layer including an imaging element and a layer including a lens (lens layer) in a wafer state (at the wafer level). For example, when driving a lens layer for autofocusing or zooming, it is difficult to configure a driving mechanism that drives a functional layer as a driven body.

  Therefore, an object of the present invention is to provide a technique capable of driving a driven body manufactured at a wafer level.

  In order to solve the above-described problems, the invention of claim 1 is a drive device, which is manufactured at a wafer level and is driven with respect to a fixed portion, and a first body that is displaced with respect to the fixed portion. A first drive layer having a displacement portion; and a second drive layer having a second displacement portion that is displaced with respect to the fixed portion, wherein the driven body includes the first displacement portion and the second displacement portion. It is pinched by.

  According to a second aspect of the present invention, in the drive device according to the first aspect of the invention, the first drive layer has a free end extended from the fixed portion, and the drive displacement generated at the free end is The second drive layer includes a first beam portion that transmits to the first displacement portion, and the second drive layer has a free end that extends from the fixed portion, and a second displacement portion that transmits the drive displacement generated at the free end to the second displacement portion. The first beam portion, the second beam portion, and the driven body constitute a parallel link mechanism including two beam portions.

  According to a third aspect of the present invention, in the drive device according to the second aspect of the present invention, the first beam portion and the second beam portion are subjected to mechanical deformation when energized, and when a mechanical deformation occurs, a predetermined electric power is generated. The predetermined electrical characteristics are used for detecting the position of the driven body.

  According to a fourth aspect of the present invention, in the drive device according to the third aspect of the invention, the first beam portion and the second beam portion are plate-like members having one main surface and another main surface, respectively. The first beam portion has the electrodynamic element on the one main surface of the first beam portion, and the second beam portion has the electrodynamic element on the other main surface of the second beam portion. Then, whether the electrodynamic element of the first beam portion is energized or the electrodynamic element of the second beam portion is switched according to the driving direction of the driven body.

  According to a fifth aspect of the present invention, in the drive device according to any of the second to fourth aspects, the first beam portion and the first displacement portion are elastically deformable by a first connection member. The second beam part and the second displacement part are connected by a second connection member that is elastically deformable.

  According to a sixth aspect of the present invention, in the drive device according to any of the third to fifth aspects, the electrodynamic element includes a thin film of a shape memory alloy.

  According to a seventh aspect of the present invention, in the driving device according to any of the third to fifth aspects, the electrodynamic element includes a thin film of a piezoelectric element.

  According to an eighth aspect of the present invention, in the drive device according to any one of the first to seventh aspects, the driven body is a lens layer.

  A ninth aspect of the present invention is an imaging apparatus, and includes the drive device according to any one of the first to eighth aspects of the present invention.

  According to the first to ninth aspects of the invention, the driven body manufactured at the wafer level can be driven.

  In particular, according to the second aspect of the present invention, stable movement of the driven body can be ensured.

  In particular, according to the third aspect of the invention, it is possible to detect the drive displacement without providing a new sensor.

  In particular, according to the fourth aspect of the present invention, the drive displacement of the driven body can be increased.

  Embodiments of the present invention will be described below with reference to the drawings.

<1. First Embodiment>
FIG. 1 is a schematic diagram showing a schematic configuration of a mobile phone 100 equipped with a camera module 500A according to the first embodiment of the present invention. In FIG. 1 and the drawings after FIG. 1, three axes XYZ orthogonal to each other are appropriately attached in order to clarify the orientation relationship.

  As shown in FIG. 1, the mobile phone 100 is configured as a foldable mobile phone, and includes a first housing 200, a second housing 300, and a hinge part 400.

  Each of the first casing 200 and the second casing 300 is a plate-shaped rectangular parallelepiped, and has a role as a casing for storing various electronic members. Specifically, the first casing 200 includes a camera module 500A and a display (not shown), and the second casing 300 includes a control unit that electrically controls the mobile phone 100, buttons, and the like. And an operating member (not shown).

  The hinge part 400 connects the first casing 200 and the second casing 300 so as to be rotatable. Thereby, the mobile phone 100 can be folded.

  FIG. 2 is a schematic cross-sectional view of the mobile phone 100 focusing on the first housing 200.

  As shown in FIG. 1 and FIG. 2, the camera module 500A is a small imaging device having a XY cross section of about 5 mm square and a thickness (depth in the Z direction) of about 3 mm, a so-called micro camera unit. (MCU).

  Hereinafter, the configuration and the like of the camera module 500A will be described.

<Configuration of camera module>
3 is a schematic cross-sectional view of the camera module 500A, and FIG. 4 is an exploded perspective view of the camera module 500A.

  As shown in FIGS. 3 and 4, the camera module 500A includes a drive mechanism KB that drives the lens layer 16 as a photographing optical system, and an imaging unit PB that acquires a photographed image related to the subject image.

  The imaging unit PB has a configuration in which, for example, an imaging element layer 11 having an imaging element 111 such as a COMS sensor or a CCD sensor, an imaging element holder layer 12, and an infrared cut filter layer 13 are stacked in this order. Yes. The light (subject light) from the object scene sequentially passes through the lens layer 16 and the infrared cut filter layer 13 as a photographing optical system and reaches the image sensor 111 of the image sensor layer 11.

  Between the imaging unit PB and the cover 19, both are manufactured in a wafer state (at the wafer level), the lens layer 16, the first actuator layer (the first actuator layer that holds the lens layer 16 and drives the lens layer 16). Drive layer) 15, second actuator layer (second drive layer) 17, and interposed between the imaging unit PB and the first actuator layer 15 to secure a drive space of the driven body (here, the lens layer 16). The first spacer 14 and the second spacer 18 that is inserted between the second actuator layer 17 and the cover 19 and that secures the drive space of the driven body are stored. The functional layers stored between the imaging unit PB and the cover 19 cooperate with each other to form a drive mechanism KB that drives the lens layer 16.

  Specifically, in the camera module 500 </ b> A, the first spacer 14 joined to the imaging unit PB and the imaging unit PB, and the cover 19 and the second spacer 18 joined to the cover 19 are both fixed parts to the lens layer 16. It becomes.

  The lens layer 16 is sandwiched between the first actuator layer 15 and the second actuator layer 17 coupled to the fixed portion.

  More specifically, the first actuator layer 15 is interposed between the imaging unit PB and the lens layer 16 on one main surface side (−Z side) of the lens layer 16. Further, a second actuator layer 17 is interposed between the cover 19 and the lens layer 16 on the other main surface side (+ Z side) of the lens layer 16. The lens layer 16 is sandwiched between a first displacement portion that is displaced with respect to the fixed portion in the first actuator layer 15 and a second displacement portion that is displaced with respect to the fixed portion in the second actuator layer 17.

  The drive displacement generated in the first actuator layer 15 and / or the second actuator layer 17 is transmitted from the first displacement portion and / or the second displacement portion to the lens layer 16. The lens layer 16 that has received the driving force from the first displacement portion and / or the second displacement portion is moved in the optical axis direction according to the direction and magnitude of the driving force.

  As described above, in the camera module 500A, the lens layer 16 that is a driven body is sandwiched between the first displacement portion of the first actuator layer 15 and the second displacement portion of the second actuator layer 17, and each displacement portion. Is driven in accordance with the driving force generated in step.

  As described above, the driving mechanism KB provided in the camera module 500A can displace the lens layer 16 manufactured at the wafer level in the optical axis direction of the lens layer 16, and causes the camera module 500A to function as a driving device.

  In addition, since the lens layer 16 is driven in a state of being sandwiched between the first displacement portion and the second displacement portion, the driving device can achieve stable driving of the lens layer 16.

<About each functional layer>
Below, the detail of each functional layer which comprises camera module 500A is demonstrated. In each functional layer, a surface on the −Z direction side is referred to as a surface on one main surface side, and a surface on the + Z direction side is referred to as a surface on the other main surface side.

○ Image sensor layer 11:
As shown in FIG. 3, the image sensor layer 11 includes an image sensor 111 that receives subject light that has passed through the photographing optical system and generates an image signal related to the subject image, its peripheral circuit, and an outer periphery that surrounds the image sensor 111. It is a member provided with a part.

  Although not shown here, wiring for applying a signal to the image sensor 111 and reading a signal from the image sensor 111 is connected to one main surface of the image sensor layer 11. Various terminals are provided.

○ Image sensor holder layer 12:
The imaging element holder layer 12 is a member that holds the imaging element layer 11 that is formed of, for example, a material such as a resin and is joined by an adhesive or the like. An opening is provided substantially at the center of the image sensor holder layer 12.

○ Infrared cut filter layer 13:
The infrared cut filter layer 13 is formed by multilayering transparent thin films having different refractive indexes on a transparent substrate.

  Specifically, the infrared cut filter layer 13 is formed by, for example, sputtering a large number of transparent thin films having different refractive indexes on the upper surface of a substrate made of glass or transparent resin, and the thickness and refractive index of the thin film. The wavelength band of the transmitted light is controlled by the combination. As the infrared cut filter layer 13, for example, a layer that blocks light in a wavelength band of 600 nm or more is employed.

○ First spacer 14 and second spacer 18:
Both the first spacer 14 and the second spacer 18 are made of a material such as a resin, and an opening is provided in the approximate center of the first spacer 14 and the second spacer 18. The first spacer 14 and the second spacer 18 are inserted between the driven body and the fixed portion, and secure a driving space of the driven body.

○ First actuator layer 15
The first actuator layer 15 is a thin plate-like member that is formed using a metal or silicon (Si) substrate as a base material and has a displacement element (also referred to as “actuator element”) that generates a driving force. FIG. 5 is a top view of the first actuator layer 15. 6 is a cross-sectional view of the first actuator layer 15 taken along the broken line II in FIG.

  As shown in FIG. 5, the first actuator layer 15 extends from the frame 151 along each side of the frame 151 inside the frame 151 and a rectangular frame 151 constituting the outer peripheral portion. Four plate-like beam portions 152, a rectangular movable portion 153 disposed adjacent to each beam portion 152 inside the frame 151, a free end FT of each beam portion 152, and a movable portion 153 And a connecting member 154 to be connected.

  The frame 151 is joined to the first spacer 14 as a fixed portion, and becomes a fixed portion for the movable portion 153.

  The connection member 154 is configured as an elastic member having a structure that can be elastically deformed, and facilitates the movement of the movable portion 153.

  A thin-film actuator element 155 is provided on the other main surface side of the beam portion 152.

For the actuator element 155, for example, a member containing a shape memory alloy (SMA) is used. In this case, after an insulating layer such as SiO ₂ , a metal heater layer, and an SMA layer are formed on the beam portion 152 using a sputtering method or the like, the beam portion 152 is set in a mold having a shape to be memorized, and a predetermined temperature ( For example, a heating process (shape memory process) at about 600 ° C. is performed.

  The SMA has a characteristic that when it reaches a predetermined temperature by being heated, it is restored to a predetermined contracted shape (also referred to as “memory shape”) stored in advance. Therefore, when the SMA is heated by energizing the heater layer, the SMA contracts and deforms into a memory shape, and the free end FT of the beam portion 152 moves in the + Z direction (see FIG. 6).

  Accordingly, the movable portion 153 coupled to the free end FT of the beam portion 152 becomes a displacement portion (first displacement portion) that is displaced with respect to the fixed portion.

  The lens layer 16 is bonded to the movable portion 153 that functions as the displacement portion, and the drive displacement generated in the displacement portion is transmitted to the lens layer 16.

  The heater layer of each beam portion 152 is connected to the electrodes 157A and 157B through the wiring 156. Further, energization of the electrodes 157A and 157B is performed through a through electrode connected to an electrode of another functional layer (for example, the image sensor layer 11).

  In addition, the amount of displacement generated on the free end FT side of the beam portion 152 differs depending on the heating temperature of the SMA, and the amount of displacement can be adjusted by controlling the amount of current supplied to the heater layer.

  The actuator element 155 also functions as a sensor that detects the position of the lens layer 16 in the driving direction. Details will be described later.

○ Lens layer 16:
The lens layer 16 is manufactured at a wafer level using a glass substrate as a base material, and is used as an optical lens for autofocusing, zooming, or camera shake correction, for example.

  The lens layer 16 is formed by stacking two or more lenses. In the present embodiment, a case where the lens layer 16 is configured by stacking three lenses is illustrated. FIG. 7 is a schematic cross-sectional view of the lens layer 16.

  As shown in FIG. 7, the lens layer 16 has a lens constituent layer LY1 having the first lens G1, a lens constituent layer LY2 having the second lens G2, and a lens constituent layer LY3 having the third lens G3. The lens constituent layers LY1 to LY3 are coupled via the ribs RB in this order.

  Each of the lens constituent layers LY1 to LY3 is produced by the same method using the glass substrate 161 as a base material. FIG. 8 is a diagram showing how the lens constituent layer LY3 having the third lens G3 is produced.

  Specifically, as shown in FIG. 8, a highly transparent acrylic or epoxy ultraviolet (UV) curable resin is applied to each of both surfaces of the glass substrate 161. Then, a transparent lens molding die 162 having the shape of each lens (the third lens G3 in FIG. 8) is pressed at a predetermined pressure and irradiated with ultraviolet rays UV1 from both sides, and each surface of the glass substrate 161 is irradiated. The polymer lenses GP1 and GP2 are respectively molded.

  In each of the lens constituent layers LY1 to LY3 manufactured by such a method, alignment marks for alignment are formed at two or more predetermined positions. The lens constituent layers LY1 to LY3 are assembled into an integrated lens layer 16 with a rib layer having a rib RB sandwiched between the lens constituent layers LY1 to LY3.

  More specifically, the lens constituent layers LY1 to LY3 and the rib layer are aligned and bonded in the shape of the substrate while confirming the respective alignment marks using a mask aligner or the like. As a bonding method, a UV curing layer is provided on the surface of the rib layer to be bonded to each of the lens constituent layers LY1 to LY3, and the bonding is performed by irradiating with ultraviolet rays, or the surface of the rib layer is irradiated with an inert gas plasma. Then, a technique (surface activated bonding method) is employed in which the surfaces of the rib layers are bonded together while being activated.

  In addition, after each functional layer including the lens layer 16 is bonded, a part of the lens layer 16 is cut so that the lens portion can be driven. The cutting of the lens layer 16 is performed, for example, by irradiating a laser to a cutting portion (a portion RH surrounded by a broken line in FIG. 7). By this cutting, the lens layer 16 is divided into a drive lens layer 168 that can be driven and a fixed lens layer 169 that is fixed. In this embodiment, the lens layer 16 is a lens layer that uses the drive lens layer 168 as a driven body. 16 is called.

  In addition, when forming a diaphragm on the camera module 500A, the diaphragm layer is formed by a method of forming a light shielding material thin film after applying a shadow mask to the layer having the second lens G2, or a resin material colored in black separately. A configuration method or the like is used.

○ Second actuator layer 17:
The second actuator layer 17 is a thin-film member having the same configuration and function as the first actuator layer 15, and includes a rectangular frame 171, four beam portions 172, a movable portion 173, and each beam portion 172. A connection member 174 that connects the free end FT and the movable portion 173 is provided (see FIG. 5).

  The frame body 171 is joined to the second spacer 18 as a fixed portion, and becomes a fixed portion for the movable portion 173.

  A thin film actuator element 175 is provided on the other main surface side of the beam portion 172. For example, a member containing SMA is used for the actuator element 175. When the SMA is heated, the free end FT of the beam portion 172 moves in the + Z direction (FIG. 6).

  Accordingly, the movable portion 173 coupled to the free end FT of the beam portion 172 becomes a displacement portion (second displacement portion) that is displaced with respect to the fixed portion.

  The lens layer 16 is bonded to the movable portion 173 that functions as the displacement portion, and the drive displacement generated in the displacement portion is transmitted to the lens layer 16.

○ Cover 19
The cover 19 is molded from a resin material, protects the drive mechanism KB, and serves as a fixing portion for the driven body (lens layer 16).

<Supporting mechanism of driven body>
Here, the support mechanism of the driven body in the camera module 500A will be described in detail. FIG. 9 is a top view of the drive mechanism KB of the camera module 500A. 10 and 11 are cross-sectional views of the drive mechanism KB taken along the broken line II-II in FIG. 9, FIG. 10 is a cross-sectional view in a non-driven state (stationary state), and FIG. 11 is a cross-sectional view in the driven state. ing.

  As described above, the lens layer 16 as the driven body is joined to the movable portion 153 of the first actuator layer 15 on one main surface side of the layer (see FIG. 10), and the second actuator on the other main surface side of the layer. It joins with the movable part 173 of the layer 17 (refer FIG. 9, FIG. 10).

  As shown in FIG. 11, in the driving state, the lens layer 16 is driven in the + Z direction according to the driving displacement generated by the bending deformation of the beam portions 152 and 172.

  As shown in FIGS. 10 and 11, the lens layer 16 is supported by a pair (one set) of beam portions 152 and 172 arranged side by side in the driving direction (here, the Z direction). More precisely, the lens layer 16 is supported by four pairs (four sets) of beam portions 152 and 172 that exist in four directions of the lens layer 16, but here, a pair of lens layers 16 that exist on one side of the lens layer 16. Note the relationship established by the beams 152,172.

  The pair of beam portions 152 and 172 that support the lens layer 16 are configured such that the lengths from the fixed end KT serving as the fulcrum to the free end FT serving as the action point to the lens layer 16 are equal to each other. . The distance between the fulcrums and the distance between the action points in the pair of beam portions 152 and 172 are equal to each other.

  That is, the support mechanism of the driven body includes a pair of beam portions 152 and 172 each having a fixed end KT and a free end FT and having the same length. In the support mechanism, the pair of beam portions 152 and 172 are arranged side by side in the driving direction, and the distance between the fixed ends KT serving as fulcrums in the pair of beam portions 152 and 172 and the lenses are mutually connected. The distance between the free ends FT serving as the point of action on the layer 16 is configured to be equal.

  In the support mechanism of the lens layer 16 having such a configuration, the pair of beam portions 152 and 172 and the lens layer 16 (specifically, the fixed lens layer 169 and the drive lens layer 168) constitute a parallel link mechanism. This makes it possible to ensure stable movement of the lens layer 16 in the optical axis direction.

<About sensor function>
Actuator elements 155 and 175 provided in beam portions 152 and 157 also function as sensors that detect drive displacement generated in the displacement portion.

  Specifically, the heater layer is deformed with the deformation of the SMA at the time of driving, but the electric resistance value of the heater layer is also changed according to the deformation of the heater layer. For this reason, the amount of displacement generated in the displacement portion is detected by flowing a small current (also referred to as “measurement current”) different from the driving current at the time of driving through the heater layer and measuring the electrical resistance value of the heater layer. can do.

  The actuator elements 155 and 175 are deformed by energization, and change the electric resistance value in accordance with the deformation. Therefore, the actuator elements 155 and 175 cause mechanical deformation by energization and exhibit predetermined electrical characteristics when mechanically deformed. It can also be expressed as an element (electrodynamic element). When a member containing SMA is adopted as the actuator elements 155 and 175, the lens layer 16 has a predetermined electrical characteristic (in this case, a change in electric resistance value) that appears according to mechanical deformation in the actuator elements 155 and 175. Used for position detection.

  As described above, the actuator elements 155 and 175 provided on the beam portions 152 and 172 function as a driving unit that generates a driving force and also detect a displacement amount of the lens layer 16, that is, a position information of the lens layer 16 (detection). Part).

  Whether the actuator elements 155 and 175 are used as a drive unit, a sensor, or a drive unit and a sensor can be freely combined.

  For example, when each actuator element 155 of the first actuator layer 15 and each actuator element 175 of the second actuator layer 17 are both used as a drive unit, the lens layer 16 can be driven with twice the driving force. Become.

  Further, for example, when each actuator element of either the first actuator layer 15 or the second actuator layer 17 is used as a drive unit and each other actuator element is not used as a drive unit, each actuator not used as a drive unit The beam portion having the element functions as a restoring force generating unit that generates a restoring force.

  Specifically, since each of the beam portions 152 and 172 is made of an elastically deformable member, a beam portion having an actuator element that does not function as a driving portion is affected by bending deformation generated in other beam portions. In the case of elastic deformation, the elastically deformed beam portion generates a restoring force that attempts to return to the original state. For this reason, when energization to the actuator element that has generated the driving force is stopped, the lens layer 16 is moved in the −Z direction by the restoring force.

  As described above, when each actuator element of the first actuator layer 15 or the second actuator layer 17 is used as the drive unit and the other actuator element is not used as the drive unit, the SMA is dissipated to restore the original. The low responsiveness when returning to the state (stationary state) can be compensated by the restoring force of the beam portion having the actuator element that does not function as the drive portion, so that the drive responsiveness can be improved. .

  For example, when the actuator element 155 of the first actuator layer 15 is used as a sensor, the position information of the lens layer 16 can be detected without adding a new position sensor.

<2. Second Embodiment>
Next, a second embodiment of the present invention will be described.

  In the camera module 500A of the first embodiment, the actuator element 155 of the first actuator layer 15 and the actuator element 175 of the second actuator layer 17 are both provided in the same direction, but the camera module 500B of the second embodiment. Then, the actuator elements 155 and 175 are provided in directions opposite to each other. 12, 13 and 14 are cross-sectional views of the drive mechanism KB of the camera module 500B taken along the broken line II-II in FIG. 9, and FIG. 12 is a cross-sectional view in the non-driven state (stationary state). 14 represents a cross-sectional view of the driving state.

  The camera module 500B according to the second embodiment has substantially the same configuration and functions as the camera module 500A of the first embodiment except that the arrangement positions of the actuator elements 155 and 175 are different (see FIGS. 3 and 4). The common parts are denoted by the same reference numerals and the description thereof is omitted.

  As shown in FIG. 12, in the camera module 500B according to the second embodiment, the actuator element 155 of the first actuator layer 15 is provided on one main surface side of the beam portion 152, and the actuator element of the second actuator layer 17 is provided. 175 is provided on the other main surface side of the beam portion 172.

  As described above, in the camera module 500B having the actuator elements 155 and 175 provided in directions opposite to each other, the actuator elements 155 and 175 used as the drive unit are switched between the first actuator layer 15 and the second actuator layer 17. Thus, the driving direction of the driven body (lens layer 16) is switched.

  Specifically, when the actuator element (here, the actuator element 175) provided on the + Z side is energized and used as a driving unit, the driving direction of the lens layer 16 becomes the + Z direction (see FIG. 13).

  On the other hand, when the actuator element (here, the actuator element 155) provided on the −Z side is energized and used as a drive unit, the driving direction of the lens layer 16 becomes the −Z direction (see FIG. 14).

  As described above, the actuator element is provided not only on the other principal surface side but also on the one principal surface side of the beam portion, and by switching the actuator element to be energized according to the driving direction, in addition to the + Z direction − Since it is also possible to drive in the Z direction, the driving displacement of the lens layer 16 can be enlarged by about twice.

<3. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the contents described above.

  For example, in the camera modules 500A and 500B in the above embodiments, SMA is used as the actuator elements 155 and 175, but the present invention is not limited to this. FIG. 15 is a top view of actuator layers 15 and 17 using members including piezoelectric elements (piezoelectric elements) as actuator elements 155 and 175.

  Specifically, as the actuator elements 155 and 175, for example, a member including a thin film (piezoelectric thin film) of a piezoelectric element such as an inorganic piezoelectric body (PZT) or an organic piezoelectric body (PVDF) can be used. In this case, an electrode, a piezoelectric thin film, and an electrode are formed on the Si substrate in this order using a sputtering method or the like, and poling with a high electric field is performed.

  Note that energization of the piezoelectric element is performed via wirings 156A and 156B as shown in FIG. The wirings 156A and 156B are connected to each other and provided on the other main surface side (front side) and one main surface side (back side) of the actuator layer 15, respectively. Specifically, the wiring 156A represented by the solid line BJ in FIG. 15 is provided on the front side of the actuator layer 15, and the wiring 156B represented by the broken line BH is provided on the back side of the actuator layer 15.

  Further, even when piezoelectric elements are used as the actuator elements 155 and 175, the actuator elements 155 and 175 can be used as sensors for detecting positional information of the lens layer 16.

  Specifically, when bending deformation occurs in the piezoelectric element by driving, charges corresponding to the bending deformation are generated at both ends of the piezoelectric element. Therefore, for example, the displacement amount generated in the displacement portion can be detected by connecting both ends of the piezoelectric element via a capacitor and measuring the voltage appearing in the capacitor.

  Moreover, in each said embodiment, although SMA was heated by electricity supply to a heater layer, it is not limited to this.

  Specifically, a current can be passed through the SMA itself to cause self-heating, thereby increasing the temperature of the SMA.

  Moreover, although each said embodiment demonstrated the case where four beam parts exist in one actuator layer, it is not limited to this.

  Specifically, it is sufficient that at least one beam portion exists in one actuator layer.

  In addition, when using an actuator element as a sensor, any one of the actuator elements included in the actuator layer may be used as a sensor.

It is a schematic diagram which shows schematic structure of the mobile telephone carrying a camera module. It is a cross-sectional schematic diagram which paid its attention to the 1st housing | casing among mobile phones. It is a cross-sectional schematic diagram of a camera module. It is a disassembled perspective view of a camera module. It is a top view of a 1st actuator layer. It is sectional drawing of the 1st actuator layer in broken line II of FIG. It is a cross-sectional schematic diagram of a lens layer. It is a figure which shows the mode of preparation of the lens structure layer which has a 3rd lens. It is a top view of the drive mechanism of a camera module. It is sectional drawing of the drive mechanism in the broken line II-II of FIG. It is sectional drawing of the drive mechanism in the broken line II-II of FIG. It is sectional drawing of the drive mechanism of the camera module which concerns on 2nd Embodiment in broken line II-II of FIG. It is sectional drawing of the drive mechanism of the camera module which concerns on 2nd Embodiment in broken line II-II of FIG. It is sectional drawing of the drive mechanism of the camera module which concerns on 2nd Embodiment in broken line II-II of FIG. It is a top view of an actuator layer using a member containing a piezoelectric element as an actuator element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Mobile phone 500A, 500B Camera module 11 Image pick-up element layer 111 Image pick-up element 12 Image pick-up element holder layer 13 Infrared cut filter layer 14 Spacer 15, 17 Actuator layer 152, 172 Beam part 153, 173 Movable part 154, 174 Connection member 155 175 Actuator element 16 Lens layer 18 Spacer 19 Cover

Claims (9)

A driven body manufactured at the wafer level and driven with respect to the fixed portion;
A first drive layer having a first displacement portion that is displaced with respect to the fixed portion;
A second drive layer having a second displacement portion that is displaced with respect to the fixed portion;
With
The driven device is a drive device that is sandwiched between the first displacement portion and the second displacement portion. The first driving layer includes
A first beam portion having a free end extended from the fixed portion, and transmitting a driving displacement generated at the free end to the first displacement portion;
Including
The second driving layer includes
A second beam portion having a free end extended from the fixed portion, and transmitting a driving displacement generated at the free end to the second displacement portion;
Including
The drive device according to claim 1, wherein the first beam portion, the second beam portion, and the driven body constitute a parallel link mechanism. The first beam portion and the second beam portion are:
It has an electrodynamic element that exhibits a predetermined electrical characteristic when it is mechanically deformed while mechanically deforming by energization,
The driving apparatus according to claim 2, wherein the predetermined electrical characteristic is used for position detection of the driven body. The first beam portion and the second beam portion are plate-like members each having one main surface and another main surface,
The first beam portion has the electrodynamic element on the one main surface of the first beam portion,
The second beam part has the electrodynamic element on the other main surface of the second beam part,
4. The method according to claim 3, wherein whether the electrodynamic element of the first beam part is energized or the electrodynamic element of the second beam part is switched according to a driving direction of the driven body. Drive device. The first beam portion and the first displacement portion are connected by a first connection member that is elastically deformable,
The drive device according to any one of claims 2 to 4, wherein the second beam portion and the second displacement portion are connected by a second connection member that is elastically deformable.   6. The drive device according to claim 3, wherein the electrodynamic element includes a thin film of a shape memory alloy.   The drive device according to claim 3, wherein the electrodynamic element includes a thin film of a piezoelectric element.   The driving apparatus according to claim 1, wherein the driven body is a lens layer.   An imaging device comprising the drive device according to any one of claims 1 to 8.

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