KR101834251B1 - Lens driving device and assembling method thereof - Google Patents

Abstract

To prevent complicating the shape of the housing for electrode attachment.
The lens driving apparatus 10 includes a lens holder 18 including a cylindrical portion 182 for holding a lens barrel and a housing 12 for movably supporting the lens holder 18 only in the optical axis O direction Moving means for moving the lens holder 18 in the direction of the optical axis O and guiding means for guiding the lens holder 18 movably only in the optical axis O direction. The moving means includes a shape memory alloy member 32 spanning between the lens holder 18 and the housing 12. At both ends of the shape memory alloy member 32, a pair of electrodes 34 for energizing the shape memory alloy member 32 are attached. The housing 12 includes an actuator base 14 disposed on the lower side of the lens holder 18 and an electrode holder 22 attached to the actuator base 14 and holding a pair of electrodes 34 .

Description

TECHNICAL FIELD [0001] The present invention relates to a lens driving device and a method of assembling the lens driving device.

The present invention relates to a lens driving apparatus, and more particularly to a lens driving apparatus using a shape memory alloy for an actuator and a method of assembling the lens driving apparatus.

2. Description of the Related Art [0002] Linear actuators using a shape memory alloy (SMA) are known as actuators for autofocusing and zooming of cameras.

For example, WO2007 / 113478A1 (Patent Document 1) discloses a camera lens driving apparatus that drives the motion of one camera lens supported by one support structure (housing) by one suspension system. The camera lens driving device disclosed in Patent Document 1 mounts a sub-assembly having SMA wires connected to at least one mounting member mounted on a supporting structure. At least two SMA wires are held with tension between the camera lens element and the support structure (housing) at an acute angle with respect to the optical axis for applying tension with components along the optical axis. The two SMA wires are held at an angle when viewed along the optical axis. The subassembly has an attachment member to which the SMA wire is connected by caulking. The attachment member is electrically connected to the SMA wire. Thus, the attachment member functions as an electrode. The attachment member (electrode) is attached to a depression formed in the support structure (annular wall).

Further, Japanese Patent Application Laid-Open No. 2007-292864 (Patent Document 2) discloses a lens driving apparatus in which transmission efficiency is improved and compactness is achieved. The lens driving apparatus disclosed in Patent Document 2 includes a fixed lens barrel (housing), a lens frame (lens holder) for holding a part or all of the lens groups (lens barrels) constituting the optical system, and a lens frame And a pressing means for pressing the lens frame in one direction in the optical axis direction. The lens driving device moves the lens frame toward the other with respect to the fixed lens barrel against the pressure of the pressing means.

The lens driving apparatus disclosed in Patent Document 2 includes a shape memory alloy (SMA) wire and a wire bearing member. Both ends of the SMA wire are fixed to the fixing column and heated by energization to reduce the length of the predetermined relaxed state. The shape memory alloy wire is returned to the length of the relaxed state when cooled by energization stop. The wire bearing member is provided on the lens frame, and an acting portion set between both ends of the shape memory alloy wire is engaged so that the convex portion is in the direction of the curved shape toward the one side.

In the embodiment of the lens driving device disclosed in Patent Document 2, the SMA wire is fixed at both ends to a pair of wire support members, and the pair of wire support members are fixed to the fixed lens barrel (housing). The energization control unit energizes both ends of the SMA wire through the pair of wire support members. Thus, the wire supporting member functions as an electrode.

Japanese Patent Application Laid-Open No. 2007-78954 (Patent Document 3) discloses a lens tilting structure configured to move an imaging lens in an optical axis direction by using a shape memory alloy. The lens tilting disclosed in Patent Document 3 uses a shape memory alloy having an imaging lens (lens barrel) for imaging subject light and a mirror frame (lens holder) for holding the imaging lens (lens barrel) The imaging lens is moved in a predetermined direction. A part of the shape memory alloy is placed in an optical path of an image pickup lens (lens barrel), and the mirror frame (lens holder) is moved by contracting the shape memory alloy by energization. Patent Document 3 also discloses a diaphragm-type leaf spring provided on both ends of the mirror frame (lens holder) in the optical axis direction as an embodiment of lens tilting.

In the lens tilting embodiment disclosed in Patent Document 3, both end portions of the shape memory alloy formed in a strip shape are fixed and fixed to a columnar portion (housing) provided upright from a ground plate by a pair of plate members. And is energized to the shape memory alloy through the plate member. Therefore, the plate member functions as an electrode.

Japanese Unexamined Patent Application Publication No. 2009-19507 (Patent Document 4) discloses a drive module and a method of assembling the same that can reduce unevenness in assembly precision while improving manufacturing efficiency. The driving module disclosed in Patent Document 3 is formed by hanging a middle portion of a shape memory alloy (SMA) wire which is driven and expanded by a driven member (lens holder) movably provided on a chassis (housing; The driving module includes a pair of holding terminals, and the chassis (housing; supporting body) has a positioning portion and a locking portion. Each holding terminal has a wire holding portion for holding the end portion of the SMA wire in a conductive manner, a to-be-positioned portion for the supporting body, and a locking portion for receiving a reaction force toward the to- And the positioning portion hooks the to-be-positioned portion of the holding terminal. The latching portion pushes the retaining portion of the retaining terminal in a pressed state toward the to-be-positioned side. The holding terminal serves as an electrode because it is a conducting portion.

WO2007 / 113478A1 Japanese Patent Application Laid-Open No. 2007-292864 Japanese Patent Application Laid-Open No. 2007-78954 Japanese Patent Application Laid-Open No. 2009-19507

The above-described Patent Documents 1 to 4 have the following problems.

In the camera lens driving apparatus disclosed in Patent Document 1, an attachment member (electrode) for shape memory alloy wire is directly attached to one support structure. As a result, the shape of the support structure becomes complicated for electrode attachment. In addition, it is difficult to disassemble the product at the time of defective characteristics, and it becomes difficult to reuse the components.

Also in the lens driving apparatus disclosed in Patent Document 2, a pair of wire supporting members (electrodes) for SMA wire are directly fixed to the fixed lens barrel (housing). As a result, the shape of the stationary lens barrel (housing) becomes complicated for electrode attachment. In addition, it is difficult to disassemble the product at the time of defective characteristics, and it becomes difficult to reuse the components.

In the lens tilting disclosed in Patent Document 3, a pair of plate members (electrodes) are directly fixed to the columnar portion (housing). As a result, the shape of the housing becomes complicated for electrode attachment. In addition, it is difficult to disassemble the product at the time of defective characteristics, and it becomes difficult to reuse the components.

In the driving module disclosed in Patent Document 4, a pair of holding terminals (electrodes) for the SMA wire are directly attached to the chassis (housing). As a result, the shape of the chassis (housing) becomes complicated for electrode attachment. In addition, it is difficult to disassemble the product at the time of defective characteristics, and it becomes difficult to reuse the components.

In addition, Patent Documents 1 to 4 all use shape memory alloy wires formed in a linear shape as shape memory alloy members. As a result, the lens displacement amount of the lens driving device is limited. In other words, the lens displacement amount of the lens driving device depends on the displacement amount of the shape memory alloy wire.

Accordingly, an object of the present invention is to provide a lens driving apparatus and a method of assembling the same that can simplify the shape of a support (actuator base) for supporting a shape memory alloy member.

The object of the present invention is to provide a lens driving apparatus and a method of assembling the lens driving apparatus which can easily disassemble a product in the event of a defective characteristic and can reuse parts.

Another object of the present invention is to provide a lens driving apparatus capable of greatly increasing the amount of lens displacement.

Other objects of the present invention will become apparent as the description proceeds.

According to the first aspect of the present invention, a lens holder 18 including a tubular portion 182 for holding a lens barrel 11 and a lens holder 18 for moving the lens holder 18 only in the optical axis O direction A moving means for moving the lens holder 18 in the optical axis O direction and a lens having a guiding means for movably guiding the lens holder 18 only in the optical axis O direction, In the driving device 10 (10A; 10B), the moving means includes a shape memory alloy member 32 (32A; 32B-1, 32B-2) extending between the lens holder 18 and the housing 12, A pair of electrodes 34 (34B-1 and 34B-2) for energizing the shape memory alloy members 32 (32A; 32B-1 and 32B-2) An actuator base 14 disposed on the lower side of the holder 18 and an electrode holder attached to the actuator base 14 and holding a pair of electrodes 34 (34B-1, 34B-2) 22) A lens driving device which is characterized by obtained.

In the lens driving apparatus 10 (10A; 10B) according to the first aspect of the present invention, the lens holder 18 protrudes radially outward from the cylindrical portion 182, and the shape memory alloy member 32 (32A 184B-1, and 184B-2) for hooking the intermediate portion 32a (32Aa; 32B-1a, 32B-2a) of the main body 32B-1, 32B-1, 32B-2. The guiding means may comprise, for example, an elastic member 26, 28 disposed between the lens holder 18 and the housing 12. In this case, the elastic members 26, 28 support the lens holder 18 displaceably only in the direction of the optical axis O in the radially positioned state. The elastic member is preferably composed of an upper leaf spring 26 and a lower leaf spring 28 which are provided on the upper side and the lower side of the tubular portion 182 of the lens holder 18 in the optical axis O direction. The upper leaf spring 26 includes an upper ring portion 262 attached to the upper end of the lens holder 18, four upper end portions 264 attached to the housing 12, And four upper arm portions 266 connecting the upper arm portions 266, respectively. And the lower leaf spring may be constituted by a pair of lower leaf springs 28. Each of the pair of lower leaf springs 28 may include a lower arcuate portion 282 attached to the lower end portion of the lens holder 18 and a pair of lower end portions 284 And a pair of lower arm portions 286 connecting the lower arc portion and the pair of lower end portions. The shape memory alloy member may be formed of a shape memory alloy wire 32 formed in a linear shape. Instead, the shape memory alloy member may be composed of shape memory alloy members 32A (32B-1, 32B-2) formed in a coil shape. A plurality of step protrusions 184 (184B-1; 184B-2) are disposed on the outer peripheral wall of the cylindrical portion 182 at an iso-angular interval with the optical axis O as a center, and the shape memory alloy members 32B- -2 may be arranged in the same number as the number of the step protrusions 184 (184B-1; 184B-2) and hooked on each step projection 184 (184B-1; 184B-2).

The upper leaf spring 26 and the lower leaf spring 26 are fixed to both ends of the lens holder 18 having the tubular portion 182 for holding the lens barrel 11 in the direction of the optical axis O. According to the second aspect of the present invention, (22, 24; 24B) attached with a shape memory alloy assembly (36; 36A; 36B-1, 36B-2) to the lens holder (18) A third step of attaching the actuator base 14 to the support members 22, 24 and 24B with the lower leaf spring 28 sandwiched from the bottom side of the lens holder 18, A fourth step of attaching the inner cover 30 to the support members 22, 24 and 24B with the upper plate spring 26 sandwiched from the upper side of the inner cover 18, 10A; 10B) including the fifth step of covering the outer-side cover (16) so as to cover the outer-side cover (16).

In the method of assembling the lens driving apparatus 10 (10A; 10B) according to the second aspect of the present invention, the shape memory alloy assemblies 36 (36A; 36B-1 and 36B-2) And a pair of electrodes 34 (34B-1 and 34B-2) electrically connected to both ends of the shape memory alloy member, and the lens holder 18 is made up of a pair of electrodes (184; 184B-1, 184B-2) protruding outwardly from the outer wall of the cylindrical portion 182 on the first side, the support members having opposite first and second sides, The first support member 22 is formed of first and second support members 22, 24 and 24B which are provided with a pair of electrodes 34 (34B-1 and 34B-2) The memory alloy assembly 36 (36A; 36B-1, 36B-2) may be attached. In this case, in the second step, the intermediate portion 32a (32Aa; 32B-1a, 32B-2a) of the shape memory alloy member 32 (32A; 32B-1, 32B- The shape memory alloy member 32 (32A-32B-1, 32B-2) is held between the lens holder 18 and the first support member 22 by being engaged with the first support member 184B- 22 to the first side of the lens holder 18 and attaching the second support member 24 (24B) to the second side of the lens holder 18.

The upper leaf spring 26 has an upper ring portion 262, four upper end portions 264 provided at the four corners and having an upper spring hole 264a, four upper end portions 264, And the lower leaf spring is composed of a pair of lower leaf springs 28. Each of the pair of lower leaf springs has a lower arc portion 282 and a lower end hole 284a May comprise a pair of lower end portions 284 and a pair of lower arm portions 286 connecting the lower arc portion and the pair of lower end portions. In this case, the first step is a step of attaching the upper ring portion 262 of the upper leaf spring 26 to the upper end portion of the tubular portion 182 of the lens holder 18, And attaching the lower circular arc portion 282 of the lens holder 18 to the lower end portion of the cylindrical portion 182.

Each of the first and second support members 22, 24, 24B has a pair of support protrusions 224, 244, 244B at both ends thereof, and each of the pair of support protrusions has a support protrusion 224a, 244a. In this case, in the second step, the support protrusions 224a, 244a of the first and second support members 22, 24, 24B are respectively engaged with the upper end holes 264 of the four upper end portions 264 of the upper leaf spring 26, (264a).

The actuator base 14 has a ring-shaped base portion 14 and four base protrusions 142 protruding upward from the four corners of the base portion. The four base protrusions have four base portions 14, And may have a projection 142a. In this case, in the third step, the four base protrusions 142a formed on the four base protrusions 142 of the actuator base 14 are respectively inserted into the pair of lower end springs 284 The four base protrusions 142 of the actuator base 14 are fixed to the pair of protrusions 223 of the first and second support members 22, 24 and 24B, respectively, (224, 244; 244B).

The upper inner cover 30 has a ring-shaped inner cover main body 302 and four locking protrusions 304 protruding downward from the four corners of the inner cover main body. Each of the four locking protrusions has a through- (304a). In this case, the fourth step is a step of supporting the first and second support members 22, 24 and 24B projecting through the upper end holes 264a of the four upper end portions 264 of the upper leaf spring 26 The first and second support members 22, 24 and 24B are provided with the protrusions 224a and 244a respectively inserted into the through holes 304a formed in the four step protrusions 304 of the inner cover 30, The upper cover 30 is attached.

It is needless to say that the reference numerals in the abovementioned parentheses are added for ease of understanding and are merely examples, and the present invention is not limited thereto.

In the present invention, since the housing includes the actuator base disposed on the lower side of the lens holder, and the electrode holder attached to the actuator base to hold the pair of electrodes, the support for supporting the shape memory alloy member Can be simplified. In addition, the product can be easily disassembled at the time of defective characteristics, and the component can be reused.

1 is a perspective view of an outer appearance of a lens driving apparatus according to a first embodiment of the present invention, viewed obliquely from a front upper side.
Fig. 2 is a perspective view obliquely viewed from the upper front, with the lens barrel omitted from the lens driving apparatus shown in Fig. 1. Fig.
Fig. 3 is a perspective view obliquely viewed from the front and obliquely from the lens driving apparatus shown in Fig. 2 omitting the outer-surface-side cover.
Fig. 4 is an exploded perspective view of the lens driving apparatus shown in Fig. 2 as viewed obliquely from front and above. Fig.
5 is a front view of the lens driving apparatus shown in Fig.
FIG. 6 is a perspective view of the SMA assembly shown in FIG. 5 attached to the electrode holder obliquely from the upper front.
Fig. 7 is a perspective view of the state shown in Fig. 6 obliquely viewed from the upper rear.
8 is a perspective view of the lens holder with an elastic member attached obliquely from the front and from above.
Fig. 9 is a perspective view of the state shown in Fig. 8 obliquely viewed from the front downward. Fig.
10A is a perspective view showing the flow of the first assembling step of the lens driving apparatus shown in Fig. 2 obliquely from the front and viewed from above.
Fig. 10B is a perspective view showing the flow of the second assembling step of the lens driving apparatus shown in Fig. 2 obliquely from the front and above. Fig.
Fig. 10C is a perspective view showing the flow of the third assembling step of the lens driving apparatus shown in Fig. 2 obliquely from the front and above. Fig.
FIG. 10D is a perspective view showing the flow of the fourth assembling process of the lens driving apparatus shown in FIG. 2 obliquely from the front and viewed from above; FIG.
Fig. 11 is a perspective view obliquely from the front and obliquely viewed from above, with the lens barrel and the outer-surface-side cover removed from the lens driving apparatus according to the second embodiment of the present invention.
12 is a front view of the lens driving apparatus shown in Fig.
FIG. 13 is a perspective view of the SMA assembly shown in FIG. 11 attached to the electrode holder obliquely from the upper rear.
14 is a perspective view showing a lens holder and an SMA assembly used in a lens driving apparatus according to a third embodiment of the present invention.
Fig. 15 is an exploded perspective view of the lens driving apparatus according to the third embodiment of the present invention, viewed obliquely from front and above. Fig.
Fig. 16 is a perspective view obliquely viewed from the front and obliquely obliquely omitting the outer-side cover from the lens driving device according to the fourth embodiment of the present invention. Fig.
Fig. 17 is a perspective view obliquely viewed from the upper front, with the actuator base, the elastic member, and the electrode holder removed from the lens driving apparatus shown in Fig. 16; Fig.
Fig. 18 is an exploded perspective view of the lens driving apparatus according to the fourth embodiment of the present invention, viewed obliquely from front and above. Fig.
19 is a front view of the lens driving apparatus shown in Fig.
20 is a top view of the lens driving apparatus shown in Fig.
FIG. 21 is a perspective view obliquely viewed from the upper front side, with the outer-side cover removed from the lens driving apparatus according to the fifth embodiment of the present invention; FIG.
Fig. 22 is a perspective view obliquely viewed from the upper front, with the actuator base, the elastic member and the electrode holder removed from the lens driving apparatus shown in Fig. 16; Fig.
FIG. 23 is an exploded perspective view of the lens driving apparatus according to the fifth embodiment of the present invention, viewed obliquely from front and above. FIG.
24 is a front view of the lens driving apparatus shown in Fig.
25 is a side view of the lens driving apparatus shown in Fig.
26 is a top view of the lens driving apparatus shown in Fig.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

A lens driving apparatus 10 according to a first embodiment of the present invention will be described with reference to Figs. 1 to 5. Fig. 1 is a perspective view of an outer appearance of the lens driving device 10 viewed obliquely from a front upper side. Fig. 2 is a perspective view of the lens driving apparatus 10 viewed obliquely from above in a state in which the lens barrel 11 is omitted. Fig. 3 is a perspective view obliquely viewed from the upper front side in a state in which the lens barrel 11 and the outer-side cover 16 are omitted. Fig. 4 is an exploded perspective view of the lens driving device 10 viewed obliquely from above in a state in which the lens barrel 11 is omitted. Fig. 5 is a front view showing the lens driving apparatus 10 in a state in which the lens barrel 11, the outer-side cover 16, and the inner-side cover (stopper) 30 are omitted.

Here, as shown in Figs. 1 to 5, orthogonal coordinate systems (X, Y, Z) are used. In the states shown in Figs. 1 to 5, in the orthogonal coordinate system (X, Y, Z), the X-axis direction is the fore-and-aft direction The direction is the vertical direction (height direction). In the examples shown in Figs. 1 to 5, the up and down direction Z is the optical axis O direction of the lens. In the present specification, the forward direction is also referred to as a first side, and the backward direction is also referred to as a second side.

However, in the actual use situation, the direction of the optical axis O, that is, the Z-axis direction is the front-back direction. In other words, the upward direction of the Z-axis is the forward direction and the downward direction of the Z-axis is the backward direction.

The illustrated lens driving apparatus 10 has a structure of plane symmetry with respect to a plane that passes through the optical axis O and is defined (extended) by the forward and backward directions X and the up and down direction Z. [

The illustrated lens driving apparatus 10 is provided in, for example, a cellular phone equipped with an autofocusable camera. The lens driving device 10 includes a lens barrel (lens assembly) 11 incorporating an autofocus lens AFL which is a movable lens. The lens driving device 10 is for moving the lens barrel 11 only in the optical axis O direction.

As shown in Fig. 1, the lens driving apparatus 10 has a substantially rectangular parallelepiped-shaped housing (housing) 12 which covers the lens barrel 11. As shown in Fig. In other words, the lens barrel 11 is disposed in the housing 12. The housing (12) includes an actuator base (14) and an outer cover (16).

On the other hand, although not shown, an imaging element arranged on the substrate is mounted at the center of the actuator base 14. [ This imaging element captures an image of a subject image formed by the movable lens AFL and converts it into an electric signal. The image pickup device is constituted by, for example, a CCD (charge coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor) type image sensor or the like.

The lens driving device 10 includes a lens holder 18 for holding the lens barrel 11. In other words, the lens barrel 11 is held and fixed in the lens holder 18. In more detail, the lens holder 18 includes a cylindrical portion 182 that is substantially cylindrical in shape. A female screw (not shown) is formed on the inner peripheral wall of the cylindrical portion 182 of the lens holder 18. On the other hand, on the outer peripheral wall of the lens barrel 11, a male screw (screw) is screwed to the female screw. Therefore, in order to mount the lens barrel 11 to the lens holder 18, the lens barrel 11 is rotated about the optical axis O with respect to the lens holder 18 and screwed along the optical axis O direction, (11) are accommodated in the lens holder (18) and bonded to each other with an adhesive or the like.

The lens holder 18 is movably supported in the housing 12 only in the direction of the optical axis O as described later. The combination of the lens barrel 11 and the lens holder 18 constitutes the lens moving parts 11, 18.

On the outer peripheral wall of the cylindrical portion 182 of the lens holder 18, a protruding portion 184 protruding radially outward from the front in the forward and backward directions X is provided. The projecting portion 184 protrudes from the upper end of the tubular portion 182 along the vertical direction Z toward the lower end. The projecting portion 184 is for engaging the intermediate portion 32a of the shape memory alloy wire 32 formed in a linear shape to be described later. Therefore, the projection 184 is also referred to as a step projection.

The actuator base 14 has a ring-shaped base portion 142 and four base protrusions 144 protruding slightly upward in the vertical direction Z from the four corners of the base portion 142. The four base protrusions 144 each have four base protrusions 144a protruding upward. A front recess 146 is formed between the two base protrusions 144 of the four base protrusions 144 and a rear recess 148 is formed between the two base protrusions 144 at the rear .

The housing (12) further has a front support member (22) and a rear support member (24). The front support member 22 is attached to the front of the actuator base 14 and the rear support member 24 is attached to the rear of the actuator base 14. [ The front support member 22 and the rear support member 24 have substantially the same shape. The front support member 22 and the rear support member 24 are arranged in a plane symmetry with respect to a plane passing through the optical axis O and defined (extended) in the left-right direction Y and the up-down direction Z . In other words, the front support member 22 and the rear support member 24 are mirror image relative to the plane.

The front support member 22 is also referred to as a first support member, and the rear support member 24 is also referred to as a second support member. The first and second support members are simply referred to as support members.

The front support member 22 is also called an electrode holder because it is for holding a pair of electrodes 34 to be described later.

The front support member (electrode holder) 22 includes a front base portion 222 to be inserted into the front concave portion 146 of the actuator base 14 and a pair of base projections A pair of front support protrusions 224 mounted on the front base portion 222 and a pair of front support connection portions 226 connecting both ends of the front base portion 222 and the pair of front support protrusions 224 . The pair of front support protrusions 224 protrude upward and have a pair of front support protrusions 224a protruding upward. Although not shown, the pair of front support protrusions 224 include a pair of front support holes 244, 252, 254, 252, 254, 252, . As will be described later, the pair of electrodes 34 are held by the pair of front support connection portions 226.

The rear support member 24 includes a rear base portion 242 to be inserted into the rear recessed portion 148 of the actuator base 14 and a pair of base projections 144 on the rear side of the actuator base 14. [ A pair of rear support protrusions 244 mounted on the rear base portion 242 and a pair of rear support protrusions 246 connecting both ends of the rear base portion 242 and the pair of rear support protrusions 244. The pair of rear support protrusions 244 protrude upward and have a pair of rear support protrusions 244a projecting upward. Although not shown, the pair of rear support protrusions 244 has a pair of rear support holes (not shown) in which a pair of base protrusions 144a protruding from a pair of rear base protrusions 144 are inserted into the bottom of the pair of rear support protrusions 244. [ .

The lens driving apparatus 10 includes an upper plate spring 26 and a pair of lower leaf springs 28 provided on the upper side and the lower side of the cylindrical portion 182 of the lens holder 18 in the direction of the optical axis O do. The upper leaf spring 26 and the pair of lower leaf springs 28 are disposed between the lens holder 18 and the housing 12 to move the lens holder 18 in the radial direction, As shown in Fig.

As described above, in the actual use situation, the upward direction in the Z-axis direction (optical axis (O) direction) is the forward direction and the downward direction in the Z-axis direction (optical axis (O) direction) is the backward direction. Therefore, the upper leaf spring 26 may be referred to as a front spring, and the pair of lower leaf springs 28 may be referred to as a rear spring.

The upper leaf spring 26 is disposed on the upper side in the optical axis O direction of the lens holder 18 and the lower leaf spring 28 is disposed on the lower side of the lens holder 18 in the direction of the optical axis O .

The upper leaf spring 26 has an upper ring portion 262 attached to the lens holder 18 and four upper ends 264 attached to the four corners of the housing 12 as described below. Four upper arm portions 266 are provided between the upper ring portion 262 and the four upper end portions 264. That is, the four upper arm portions 266 connect the upper ring portion 262 and the four upper end portions 264.

The upper ring portion 262 of the upper leaf spring 26 is fixed to the tubular portion 182 of the lens holder 18. In detail, the lens holder 18 has four upper holder projections 186 projecting radially outward from the top of the tubular portion 182. The four upper holder projections 186 each have four upper holder projections 186a projecting upward. The upper ring portion 262 of the upper leaf spring 26 has four upper spring holes 262a into which the upper holder protrusions 186a are inserted.

The four upper end portions 264 of the upper leaf spring 26 are engaged with a pair of the front support protrusions 224 of the front support member 22 and a pair of the rear support protrusions 244 of the rear support member 24. [ Respectively. The four upper end portions 264 of the upper leaf spring 26 each include a pair of front support protrusions 224a and a pair of rear support protrusions 244 formed on the pair of front support protrusions 224 And four upper end holes 264a into which a pair of rear support protrusions 244a formed in the upper end holes 264a are fitted. The housing 12 further has an inner cover 30 made of resin and provided inside the outer-surface-side cover 16. And the four upper end portions 264 of the upper leaf spring 26 are fixed by the inner upper cover 30.

In detail, the inner cover 30 includes a ring-shaped inner cover body 302, four locking protrusions 304 slightly protruding downward from the four corners of the inner cover body 302, And a pair of rear extension portions 308 extending downward from the vicinity of the pair of rear projection portions 304. The pair of rear extension portions 306 extend downward from the vicinity of the pair of protruding portions 304 of the front- ). The four step protrusions 304 are formed by four through holes 304a through which a pair of front protrusions 224a of the front support member 22 and a pair of rear support protrusions 244a of the rear support member 24 are inserted, ). The four upper end portions 264 of the upper leaf spring 26 are engaged with the four step projection portions 304 of the inner upper cover 30 and the pair of front support protrusions 224 and 224 of the front support member 22, Is held between the pair of rear support protrusions (244) of the rear support member (24). The inner upper cover 30 is also called a stopper since it has a function of preventing the upper leaf spring 26 from escaping from the front support member 22 and the rear support member 24.

Thus, the housing 12 includes an actuator base 14, an outer cover 16, a front support member (electrode holder) 22, a rear support member 24, and an inner cover (stopper) 30 .

One of the pair of lower leaf springs 28 is provided on the right side in the left and right direction Y and the other is provided on the left side in the left and right direction Y. [ The pair of lower leaf springs 28 are arranged in plane symmetry with respect to the plane passing through the optical axis O and extending (extending) in the forward and backward directions X and the up and down direction Z. [ In other words, one and the other of the pair of the lower leaf springs 28 are in a linear relationship with respect to the plane.

The lower leaf spring 28 on the right side has a lower arc portion 282 extending in an arc shape in the forward and backward direction X and a pair of lower end portions 284 provided on two corners in the forward and backward direction X on the right side, . A pair of lower arm portions 286 are provided between the lower circular arc portion 282 and the pair of lower end portions 284. That is, the pair of lower arm portions 286 connects the lower arc portion 282 and the pair of lower end portions 284. The pair of lower end portions 284 has a pair of lower end holes 284a in which a pair of base projections 144a provided on the right side of the four base projections 144a of the actuator base 14 are fitted. A pair of lower end portions 284 of the right side lower leaf spring 28 are engaged with the pair of base projecting portions 144 on the right side of the actuator base 14 and the pair of base projecting portions 144 on the right side of the front support member 22, And between the right projecting portion 224 and the right projecting portion 244 of the rear support member 24. The lower arc portion 282 of the right side lower leaf spring 28 is attached to the right side of the lower end portion of the cylindrical portion 182 of the lens holder 18.

Likewise, the left lower leaf spring 28 includes a lower arc portion 282 extending in a forward and backward direction X from the left and a pair of lower ends 284). A pair of lower arm portions 286 are provided between the lower circular arc portion 282 and the pair of lower end portions 284. That is, the pair of lower arm portions 286 connects the lower arc portion 282 and the pair of lower end portions 284. The pair of lower end portions 284 has a pair of lower end holes 284a in which a pair of base projections 144a provided on the left side of the four base projections 144a of the actuator base 14 are fitted. A pair of lower end portions 284 of the left lower leaf spring 28 are connected to a pair of left and right base projecting portions 144 of the actuator base 14 and a pair of left and right projecting portions 144, And between the rearward projecting portion 244 of the rear support member 24 and the left rearward projecting portion 244 of the rear support member 24. The lower arc portion 282 of the left lower leaf spring 28 is attached to the left side of the lower end portion of the cylindrical portion 182 of the lens holder 18.

The elastic member 20 including the upper leaf spring 26 and the pair of lower leaf springs 28 functions as guiding means for guiding the lens holder 18 movably only in the optical axis O direction. Each of the upper plate spring 26 and the lower plate spring 28 is made of a metal such as beryllium copper, phosphor bronze or stainless steel. The upper plate spring 26 and the lower plate spring 28 are manufactured by press working for a predetermined thin plate or by etching using a photolithography technique. Further, etching is preferable to press working. This is because residual stress is not left in the etching process.

With this configuration, the lens movable parts 11 and 18 can move only in the optical axis O direction with respect to the optical body (housing) 12. [

The lens driving apparatus 10 includes a shape memory alloy wire 32 formed in a line shape and disposed in the vicinity of the outer wall of the cylindrical portion 182 of the lens holder 18 and two And a pair of electrodes 34 electrically connected to each other. The combination of the shape memory alloy (SMA) wire 32 and the pair of electrodes 34 is referred to as a shape memory alloy (SMA) assembly 36. The SMA assembly 36 is held in a front support member (electrode holder) 22 as described below.

With reference to Figs. 6 and 7, the attachment state of the SMA assembly 36 to the front support member (electrode holder) 22 will be described. 6 is a perspective view of the SMA assembly 36 attached to the electrode holder 22 obliquely from the upper front. 7 is a perspective view of the state in which the SMA assembly 36 is attached to the electrode holder 22 as viewed obliquely from the upper rear.

The pair of electrodes 34 have a symmetrical shape. The pair of electrodes 34 extend substantially in the up-and-down direction (Z). Each of the electrodes 34 has a substantially L-shaped supported portion 342 held by the front support connection portion 226, a connection portion 344 bent in a U-shaped cross section in the upper end portion of the supported portion 342, Like terminal portion 346 extending downward from an inner end portion of the terminal portion 346. [ Each electrode 34 caulkes the connection portion 344 and is electrically connected to the end portion of the shape memory alloy wire 32. The terminal portion 346 receives a drive current from a drive circuit (not shown).

6, the supported portion 342 of the electrode 34 is held on the back surface of the front support connection portion 226 of the electrode holder 22. As shown in Fig. The supported portion 342 has a circular hole 342a.

7, the front support connection portion 226 has a cylindrical first protrusion 226a protruding rearward from the back surface thereof so as to be fitted into the circular hole 342a of the supported portion 342. As shown in Fig. The front support connection portion 226 has a second protrusion 226b protruding rearward from its back surface so as to be caught by the bottom surface portion of the supported portion 342. [ The front support connection portion 226 has a third protruding portion 226c in the form of a substantially triangular prism protruding rearward from the rear surface thereof so as to engage with the inner bent portion of the L-shaped portion of the supported portion 342. [ The outer surface of the supported portion 342 of the electrode 34 is hooked on the inner wall of the front support protrusion 224 of the electrode holder 22.

In this way, the SMA assembly 36 is attached to the front support member (electrode holder) 22. On the other hand, the intermediate portion 32a of the shape memory alloy wire 32 is engaged with the projecting portion (hooking projection) 184 of the lens holder 18. That is, the shape memory alloy wire 32 extends between the lens holder 18 and the housing 12.

Next, a schematic operation of the lens driving apparatus 10 will be described.

As is well known, a " shape memory alloy " is a metal having a property that a given strain is zero in a specific temperature range and is restored to its original shape. The shape memory alloy is made of, for example, a TiNi alloy.

The shape memory alloy wire 32 shown in the drawing is a type which shrinks to a contraction length previously stored when self-heating by energization occurs and returns to a predetermined original length (relaxed length) by natural cooling when energization stops Respectively.

The elastic member 20 acts to press the lens holder 18 downward along the optical axis O direction. On the other hand, the shape memory alloy wire 32 is contracted when energized through a pair of electrodes 34 from a driving circuit (not shown). As a result, the lens holder 18 moves upward along the optical axis O direction against the pressing force of the elastic member 20 in the downward direction.

On the other hand, when energization of the shape memory alloy wire 34 is stopped, the shape memory alloy wire 32 is naturally cooled. As a result, the shape memory alloy wire 32 is stretched by the downward pressing force of the elastic member 20. As a result, the lens holder 18 moves downward along the optical axis O direction.

That is, the shape memory alloy wire 32 is expanded and contracted in the direction of the optical axis O by the temperature change due to energization / deactivation, and functions as a moving means for moving the lens holder 18 in the optical axis O direction.

The combination of the elastic member 20 and the SMA assembly 36 allows the lens driving portions 20 and 36 for driving the lens moving portions 11 and 18 while movably supporting the lens moving portions 11 and 18 in the direction of the optical axis O ).

The lens driving portions 20 and 36 and the lens moving portions 11 and 18 are provided side by side with respect to the optical axis O as shown in Fig. Therefore, the lens driving apparatus 10 can be lowered (reduced in height).

Next, a method of assembling the lens driving apparatus 10 will be described with reference to Figs. 8 to 10D. 8 is a perspective view of the lens holder 18 with the elastic member 20 attached obliquely as viewed from the upper front. 9 is a perspective view of the lens holder 18 with the elastic member 20 attached obliquely from the front downward. FIGS. 10A to 10D are perspective views showing the flow of the first to fourth assembling steps of the lens driving device 10 obliquely viewed from the upper front.

8 and 9, the elastic member 20 is attached to the lens holder 18 first.

In this state, the upper ring portion 262 of the upper leaf spring 26 is fixed to the upper end of the cylindrical portion 182 of the lens holder 18 as shown in Fig. Four upper holder protrusions 186a formed on the four upper holder protrusions 186 protruding from the upper end of the cylindrical portion 182 are inserted into the four upper spring holes 262a formed in the upper ring portion 262, .

9, the lower arc portion 282 of the pair of lower leaf springs 28 is attached to the lower end portion of the cylindrical portion 182 of the lens holder 18.

The front support member (electrode holder) 22, the SMA assembly 36, and the rear support member 24 are attached to the lens holder 18 with the elastic member 20 attached thereto as shown in FIG. 10A .

In detail, first, an assembly formed by attaching the SMA assembly 36 to the front support member (electrode holder) 22 as shown in Figs. 6 and 7 is attached to the lens holder 18. Fig. At this time, a pair of front support protrusions 224a formed on the pair of front support protrusions 224 of the front support member (electrode holder) 22 are sandwiched between a pair of upper ends 264 formed in the upper end holes 264a. The intermediate portion 32a (see Figs. 6 and 7) of the shape memory alloy wire 32 is caught by the projecting portion (hooking projection) 184 of the lens holder 18. A pair of rear support protrusions 244a formed on a pair of rear support protrusions 244 of the rear support member 24 are connected to a pair of upper ends 264 formed on a pair of upper ends 264 of the upper plate spring 26 And is inserted into the upper end hole 264a.

Next, as shown in Fig. 10B, the actuator base 14 is attached to the front support member (electrode holder) 22 and the rear support member 24. At this time, a pair of base protrusions 144a (see Fig. 4) formed on a pair of base protrusions 144 in front of the actuator base 14 are formed by a pair of front support members (electrode holders) A pair of base protrusions 144a (see Fig. 4) inserted in a pair of front support holes (not shown) formed in the front support protrusions 224 and formed on a pair of base protrusions 144 on the rear side, (Not shown) formed in a pair of rear support protrusions 144 of the member 24. [

Subsequently, as shown in Fig. 10C, the inner cover 30 is attached to the front support member (electrode holder) 22 and the rear support member 24. At this time, the upper leaf spring 26 is clamped and fixed between the inner upper cover 30 and the front support member (electrode holder) 22 and the rear support member 24.

A pair of upper end portions 264 in front of the upper leaf spring 26 are connected to a pair of step protruding portions 304 in front of the inner upper cover 30 and a pair And is held and fixed between the pair of front support protrusions 224. A pair of upper end portions 264 of the rear side of the upper side leaf spring 26 are engaged with a pair of step projection portions 304 on the rear side of the inner side cover 30 and a pair of rear support members 24 of the rear support member 24, And is sandwiched and fixed between the protruding portions 244.

Finally, the outer side cover 16 is covered and attached to the assembly shown in Fig. 10C as shown in Fig. 10D.

In this manner, in the present embodiment, the lens driving apparatus 10 can be manufactured step by step. As a result, the tact up to the completion of the product can be shortened, and the adhesion of dust can be suppressed as much as possible.

After that, the lens barrel 11 is attached to the lens holder 18 as described above.

The lens driving apparatus 10 according to the first embodiment described above exhibits the following effects.

Since the shape memory alloy wire 32 (SMA assembly 36) to which the pair of electrodes 34 is attached is attached to the actuator base 14 through the electrode holder 22, The shape can be simplified.

As shown in Fig. 10, since the lens driving apparatus 10 can be manufactured step by step, the lens driving apparatus 10 (product) can be easily disassembled when the characteristic is defective. As a result, components can be reused.

The lens driving apparatus 10A according to the second embodiment of the present invention will be described with reference to Figs. 11 to 13. Fig. 11 is a perspective view obliquely viewed from the upper front side in a state in which the lens barrel 11 and the outer-side cover 16 are omitted in the lens driving apparatus 10A. 12 is a front view of the lens driving apparatus 10A shown in Fig. 13 is a perspective view of the state in which the SMA assembly is attached to the electrode holder 22 as viewed obliquely from the upper rear.

The illustrated lens driving apparatus 10A has the same configuration as that of the lens driving apparatus 10 shown in Figs. 1 to 7 except that the configuration of the shape memory alloy member (SMA assembly) is different as described later . Therefore, the shape memory alloy member and the SMA assembly are denoted by reference numerals 32A and 36A, respectively. The same constituent elements as those of the lens driving apparatus 10 are denoted by the same reference numerals, and a description thereof will be omitted, and only differences will be described below.

The illustrated shape memory alloy member 32A is formed of a shape memory alloy member formed in a coil shape. The illustrated shape memory alloy member 32A has a length of, for example, 3 mm in a state in which the shape memory alloy member 32A does not extend (natural state). 11 and 12, when the shape memory alloy member 32A is placed so that the intermediate portion 32Aa of the shape memory alloy member 32A is hooked on the projecting portion (the projecting projection) 184 of the lens holder 18, The length of the alloy member 32A is, for example, 7 mm. On the other hand, the thickness (diameter) of the wire of the shape memory alloy member 32 is 0.05 mm.

For this reason, in the shape memory alloy wire 32 formed in a linear shape, for example, only about 4% is shrunk, whereas in the shape memory alloy member 32A formed in a coil shape, It is possible. Therefore, in the lens driving apparatus 10A according to the second embodiment, the movable ranges (strokes) of the lens moving parts 11 and 18 can be made longer than the lens driving apparatus 10 according to the first embodiment.

The lens driving apparatus 10A having the above-described structure operates in the same manner as the lens driving apparatus 10 according to the first embodiment described above, so that the description of the operation thereof will be omitted.

In any case, the shape memory alloy member 32A is expanded and contracted in the direction of the optical axis O by the temperature change due to energization / deactivation, and functions as a moving means for moving the lens holder 18 in the optical axis O direction.

The combination of the elastic member 20 and the SMA assembly 36A is a combination of the lens driving parts 20 and 36A for driving the lens moving parts 11 and 18 while movably supporting the lens moving parts 11 and 18 in the direction of the optical axis O ).

The lens driving portions 20 and 36A and the lens moving portions 11 and 18 are provided side by side with respect to the optical axis O as shown in Fig. Therefore, the lens driving apparatus 10A can be lowered.

The method of assembling the lens driving apparatus 10A is the same as the assembling method of the lens driving apparatus 10 described with reference to Figs. 8 to 10, and therefore the description thereof will be omitted.

The lens driving apparatus 10A according to the second embodiment described above exhibits the following effects.

Since the shape memory alloy member 32A (SMA assembly 36A) to which the pair of electrodes 34 are attached is attached to the actuator base 14 via the electrode holder 22, The shape can be simplified.

Since the SMA assembly 36A is attached to the actuator base 14 via the electrode holder 22, the lens driving apparatus 10A (product) can be easily disassembled when the characteristics are defective. As a result, components can be reused.

Since the shape memory alloy member 32A is formed in a coil shape, the entire length of the wire of the shape memory alloy member 32A can be made longer than the shape memory alloy wire 32 of the linear shape. Therefore, the elastic force of the shape memory alloy member 32A can be improved. As a result, it becomes possible to largely increase the amount of lens displacement (stroke of the lens moving part) of the lens driving device 10A.

A lens driving apparatus 10B according to a third embodiment of the present invention will be described with reference to Figs. 14 and 15. Fig. FIG. 14 is a perspective view showing a lens holder and an SMA assembly used in a lens driving apparatus according to a third embodiment of the present invention, FIG. 15 is a perspective view of the lens driving apparatus according to the third embodiment of the present invention, viewed obliquely from above Fig.

The lens driving apparatus 10B of the third embodiment is different from the lens driving apparatus 10B of the first embodiment shown in Figs. 1 to 7 except that the configurations of the SMA assembly and the electrode holder and the step projection (projecting portion) And operates with the same configuration as that of the driving apparatus 10. [ Therefore, the SMA assembly, the electrode holder, and the step projection (projection) are denoted by reference numerals 36B-1, 36B-2, and 22, 24B, and 184B-1, 184B-2, respectively. The same components as those of the lens driving apparatus 10 of the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted. Only differences between the first embodiment and the third embodiment will be described below.

First, the first projecting protrusions (protruding portions) 184B-1 and 184B-2, which are the first differences between the first and third embodiments, will be described.

In the lens driving apparatus 10B according to the third embodiment, the locking projections (projections) 184B are provided in one place in the lens driving apparatus 10 according to the first embodiment, -1, and 184B-2 are provided at two positions.

In detail, in the lens driving apparatus 10B according to the third embodiment, a pair of protruding radially outward from the front in the forward and backward directions X is formed on the outer peripheral wall of the cylindrical portion 182 of the lens holder 18 The protrusions 184B-1 and 184B-2 are formed. The protruding portion 184B-1 is formed in front of the cylindrical portion 182 and the protruding portion 184B-2 is formed in the rear of the cylindrical portion 182. [ The pair of protrusions 184B-1 and 184B-2 are formed at positions shifted by 180 degrees from each other about the optical axis O positioned at the center of the cylindrical portion 182 as shown in Fig. In other words, the pair of protrusions 184B-1 and 184B-2 pass through the optical axis O and are also symmetrical with respect to the plane defined by the left-right direction Y and the up-down direction Z Respectively. Each of the projections 184B-1 and 184B-2 protrudes in the form of a hook along the vertical direction Z from the upper end side to the lower end side of the tubular portion 182. [ The protrusions 184B-1 and 184B-2 are for fastening the intermediate portions 32B-1a and 32B-2a of the shape memory alloy wires 32B-1 and 32B-2 formed in a coil shape to be described later. Therefore, the projecting portions 184B-1 and 184B-2 are also referred to as a step projection.

Next, the electrode holders 22 and 24B which are the second difference between the first embodiment and the third embodiment will be described.

In the lens driving apparatus 10 according to the third embodiment, only the front support member 22 functions as an electrode holder, while the lens support apparatus 22 according to the first embodiment functions as the electrode holder, The rear support member 24B also functions as an electrode holder.

In detail, the housing (housing) 12 has a front support member 22 and a rear support member 24B functioning as an electrode holder. Here, the front support member 22 according to the third embodiment is completely the same as the front support member 22 according to the first embodiment, and a description thereof will be omitted. Since the rear support member 24B in the third embodiment is substantially the same as the rear support member 24 in the first embodiment, the rear support member 24B and the rear support member 24B in the third embodiment Only the differences of the rear support members 24 in the first embodiment will be described below, and the description of other configurations is omitted.

The rear support member 24B in the third embodiment functions as an electrode holder for holding a pair of electrodes 34B-2, and the support portion 342B- 2 at its back surface. The rear support connection portion 246B has a cylindrical first protrusion 246Ba protruding forward from its back surface so as to be fitted into the circular hole 342B-2a of the supported portion 342B-2. The rear support connection portion 246B has a second protrusion 246Bb protruding forward from its back surface so as to engage with the bottom surface portion of the supported portion 342B-2. The rear support connecting portion 246B has a substantially triangular prism-shaped third projection 246Bc protruding rearward from the rear surface thereof so as to engage with the L-shaped inner bent portion of the supported portion 342B-2. The outer side surface of the supported portion 342B-2 of the electrode 34B-2 is hooked on the inner side wall of the rear support projection 244B of the rear support member 24B.

Next, SMA assemblies 36B-1 and 36B-2 (shape memory alloy members 32B-1 and 32B-2), electrodes 34B-1 and 34B-2 which are the third of the difference between the first embodiment and the third embodiment, 2) will be described.

In the lens driving apparatus 10 according to the first embodiment, one SMA assembly 36 (shape memory alloy member 32, pair of electrodes 34) is provided. On the other hand, in the lens driving apparatus 10 according to the third embodiment In the lens driving apparatus 10B, two SMA assemblies 36B-1 and 36B-2 (shape memory alloy members 32B-1 and 32B-2, a pair of electrodes 34B-1 and 34B-2) Is installed.

In detail, the lens driving apparatus 10B according to the third embodiment includes a first SMA assembly 36B-1 (a shape memory alloy member 32B-1, a pair of electrodes 34B-1) A second SMA assembly 36B-2 (shape memory alloy member 32B-2, a pair of electrodes 34B-2) configured in the same manner as the first SMA assembly 36B-1.

The supported portion 342B-1 of the pair of electrodes 34B-1 constituting the first SMA assembly 36B-1 is connected to the front support connection portion 226 of the electrode holder (front support member) And is maintained on the back surface. The supported portion 342B-2 of the pair of electrodes 34B-2 constituting the second SMA assembly 36B-2 is connected to the rear surface of the back support connection portion 246B of the electrode holder (rear support member) Lt; / RTI >

In the lens driving apparatus 10B according to the third embodiment, while the shape memory alloy member 32 is formed in a linear shape in the lens driving apparatus 10 according to the first embodiment, Members 32B-1 and 32B-2 are formed in a coil shape.

In detail, the shape memory alloy members 32B-1 and 32B-2 of the third embodiment are formed of shape memory alloy members formed in a coil shape. The illustrated shape memory alloy members 32B-1 and 32B-2 have a length of, for example, 3 mm in a state in which they are not extended (natural state). As shown in Fig. 14, the shape memory alloy members 32B-1 and 32B-2 are arranged such that their intermediate portions 32B-1a and 32B-2a are protruded (projected) from the lens holder 18 184B-1, 184B-2, the length of the shape memory alloy members 32B-1, 32B-2 becomes, for example, 7 mm. The diameter (diameter) of the wire of the shape memory alloy members 32B-1 and 32B-2 is 0.05 mm.

Therefore, in the shape memory alloy wire 32 of the first embodiment formed in a line shape, the shape memory alloy wire 32B-1 of the third embodiment formed in a coil shape, for example, only about 4% , And 32B-2, it is possible to contract, for example, 200% or more. Therefore, in the lens driving apparatus 10B according to the third embodiment, the movable ranges (strokes) of the lens moving parts 11 and 18 can be made longer than the lens driving apparatus 10 according to the first embodiment.

The lens driving apparatus 10B having the above-described structure operates in the same manner as the lens driving apparatus 10 according to the first embodiment described above, so that the description of its operation will be omitted.

Anyway, the shape memory alloy members 32B-1 and 32B-2 are contracted due to the temperature change due to energization / deactivation thereof, and are held by the lens holder 18 through projections (step projections) 184B-1 and 184B- To move in the direction of the optical axis (O).

The combination of the elastic member 20 and the SMA assemblies 36B-1 and 36B-2 allows the lens moving parts 11 and 18 to move in the optical axis O direction while driving the lens moving parts 11 and 18 And functions as the lens driving units 20, 36B-1, and 36B-2.

The lens driving portions 20, 36B-1, 36B-2 and the lens moving portions 11, 18 are provided side by side with respect to the optical axis O. Therefore, the lens driving apparatus 10B can be lowered.

The method of assembling the lens driving apparatus 10B according to the third embodiment is the same as the assembling method of the lens driving apparatus 10 according to the first embodiment described with reference to Figs. 8 to 10, and the description thereof will be omitted.

The lens driving apparatus 10B according to the third embodiment described above exhibits the following effects.

The shape memory alloy members 32B-1 and 32B-2 (SMA assemblies 36B-1 and 36B-2) to which the pair of electrodes 34B-1 and 34B- So that the shape of the actuator base 14 can be simplified.

Since the SMA assemblies 36B-1 and 36B-2 are attached to the actuator base 14 via the electrode holders 22 and 24B, the lens driving apparatus 10B (product) can be easily disassembled . As a result, components can be reused.

Since the shape memory alloy members 32B-1 and 32B-2 are formed in a coil shape, the entire shape of the wire members of the shape memory alloy members 32B-1 and 32B-2 The length can be made longer. Therefore, the elastic force of the shape memory alloy members 32B-1 and 32B-2 can be improved. As a result, it becomes possible to largely increase the amount of lens displacement (stroke of the lens moving part) of the lens driving device 10B.

Two of the step projections 184B-1 and 184B-2 are provided on the outer peripheral wall of the tubular portion 182 at regular angular intervals about the optical axis O, Two SMA assemblies 36B-1 and 36B-2 are provided by providing two shape memory alloy members 32B-1 and 32B-2 (SMA assemblies 36B-1 and 36B-2) -1 is applied to the movable parts 11 and 18 with respect to the optical axis O direction at the time of operation of the lens driving device 10B, Can be suppressed.

Further, by driving the lens moving parts 11 and 18 by the two shape memory alloy members 32B-1 and 32B-2, the driving force required for each shape memory alloy member 32B-1 and 32B- The shape memory alloy members 32B-1 and 32B-2 can have a wider design freedom.

In the present embodiment, two stepping protrusions (protruding portions) and two shape memory alloy members are provided. However, the number of the step protrusions (protruding portions) and the shape memory alloy members may be three, four, Does not matter.

A lens driving apparatus 10C according to a fourth embodiment of the present invention will be described with reference to Figs. 16 to 20. Fig. Fig. 16 is a perspective view obliquely from above and obliquely omitting the outer-side cover from the lens driving apparatus according to the fourth embodiment of the present invention, Fig. 17 is a plan view of the lens- Fig. 18 is an exploded perspective view of the lens driving apparatus according to the fourth embodiment of the present invention, viewed obliquely from above and from above, Fig. 19 is a perspective view of the lens driving apparatus shown in Fig. 17, And Fig. 20 is a top view of the lens driving apparatus shown in Fig.

The lens driving apparatus 10C of the fourth embodiment is different from the lens driving apparatus 10C of the first embodiment shown in Figs. 1 to 7 except that the configuration of the lens holder, the lens driving unit, and the actuator base is different as described later. (10). Therefore, the same reference numerals are given to the same constituent elements as the constituent elements of the lens driving apparatus 10 of the first embodiment, and their explanations are omitted, and only the differences between the first and fourth embodiments will be described do.

First, the lens holder 18C, which is the first difference between the first embodiment and the fourth embodiment, will be described.

The lens holder 18 in the lens driving apparatus 10 according to the first embodiment has one projection projection 184 for holding the shape memory alloy wire 32. On the other hand, The lens holder 18C in the lens driving apparatus 10C according to the first embodiment is provided with the projecting projections 184C-1 and 184C-2 projecting the shape memory alloy wires 32C-1 and 32C- (Projection portions) 188C-1a, 188C-1b, 188C-2a, and 188C-2b for pressing the shape memory alloy 38C-1 and 38C- I have dogs.

First, the projection projections (projections) 184C-1 and 184C-2 will be described in detail below.

The lens driving apparatus 10C according to the fourth embodiment is provided with a pair of step protrusions 182C protruding outward in the radial direction from the front and rear of the front and rear direction X on the outer peripheral wall of the cylindrical portion 182C of the lens holder 18C (184C-1, 184C-2) are formed. The step protrusion 184C-1 is formed in front of the cylindrical portion 182C and the step projection 184C-2 is formed in the rear of the cylindrical portion 182C. As shown in Figs. 16 to 20, the pair of step protrusions 184C-1 and 184C-2 are disposed at positions displaced from each other by 180 degrees about the optical axis O positioned at the center of the cylindrical portion 182C Respectively. In other words, the pair of step protrusions 184C-1 and 184C-2 are formed on the plane passing through the optical axis O and defined by (extending to) the left-right direction Y and the up-down direction Z And are arranged in a plane symmetry. Each of the step protrusions 184C-1 and 184C-2 protrudes in the form of a hook along the vertical direction Z from the upper end side to the lower end side of the tubular portion 182C. These step projections 184C-1 and 184C-2 are for fastening the intermediate portions 32C-1a and 32C-2a of the shape memory alloy wires 32C-1 and 32C-2 formed in a line shape to be described later.

Next, pressing projection projections (projections) 188C-1a, 188C-1b, 188C-2a, and 188C-2b will be described in detail below.

Four pressing projections 188C-1a, 188C-1b, and 188C-2a projecting radially outward from the front and rear of the forward and backward directions X on the outer peripheral wall of the cylindrical portion 182C of the lens holder 18C , And 188C-2b are formed. A pair of pressing projections 188C-1a and 188C-1b of the four pressing pressing projections 188C-1a, 188C-1b, 188C-2a, and 188C-2b are provided in front of the cylindrical portion 182C Respectively. A pair of pressing projections 188C-2a and 188C-2b are formed behind the tubular portion 182C. A pair of pressing hooks 188C-1a and 188C-1b are located above the hooking protrusion 184C-1 in a state where two hooking protrusions 188C-1a and 188C-1b are arranged side by side in the left-right direction Y. [ Specifically, in order to position the midpoint of a pair of pressing projections 188C-1a and 188C-1b on the line extending upwardly along the vertical direction Z through the step projection 184C-1, The pair of pressing projections 188C-1a and 188C-1b are disposed. Similarly, a pair of pressing hooks 188C-2a and 188C-2b are located above the hooking protrusion 184C-2 in a state in which two pressing hooking projections 188C-2a and 188C-2b are arranged side by side in the left-right direction Y. [ More specifically, in order to position the midpoint of a pair of pressing projections 188C-2a and 188C-2b on the line extending upward along the vertical direction Z through the step projection 184C-2, The pair of pressing projections 188C-2a and 188C-2b are disposed. The pressing protrusions 188C-1a, 188C-1b, 188C-2a, and 188C-2b protrude in the form of a hook along the vertical direction Z from the lower end side to the upper end side of the tubular portion 182C . Each of the pressing protrusions 188C-1a, 188C-1b, 188C-2a and 188C-2b is pressed against the middle portion 38C-1 of the pressing shape memory alloy 38C- 1a, and 38C-2a.

The lens holder 18C in the lens driving apparatus 10C according to the fourth embodiment is different from the lens holder 18C in the lens holder 18 in the lens driving apparatus 10 according to the first embodiment, (186).

Next, the actuator base 14C, which is the second difference between the first embodiment and the fourth embodiment, will be described.

In the lens driving apparatus 10 according to the first embodiment, the electrode holder 22 and the actuator base 14 are formed separately, whereas in the lens driving apparatus 10C according to the fourth embodiment, Is provided on the actuator base 14C.

More specifically, the actuator base 14C of the fourth embodiment includes a ring-shaped base portion 142C and four first (first) and second Electrode holder portion 144C and two second electrode holder portions 146C projecting upward from the base portion 142C in the vertical direction Z between the first electrode holder portion 144C. The four first electrode holder portions 144C have substantially the same shape. The two second electrode holder portions 146C have substantially the same shape. The four first electrode holder portions 144C are for holding electrodes 34C-1 and 34C-2 described later and alloy holding portions 382C-1 and 382C-2 described later. The two second electrode holder portions 146C hold the electrodes 34C-1 and 34C-2 described later and the lower leaf spring 28C in the forward and backward directions X and the left and right directions Y .

Next, the lens driving unit which is the third difference between the first and fourth embodiments will be described.

In the lens driving apparatus 10 according to the first embodiment, the lens driving unit is composed of a combination of the elastic member 20 and one shape memory alloy wire 32 for driving, The lens driving unit includes a resilient member 20C, two shape memory alloy wires 32C-1 and 32C-2 for driving, two pressing shape memory alloys 38C- 1, and 38C-2.

First, the elastic member 20C will be described in detail below.

The elastic member 20C includes an upper leaf spring 26C disposed on the upper side of the optical axis O of the lens holder 18C and a lower leaf spring 26C disposed on the lower side of the lens holder 18C in the direction of the optical axis O 28C. The upper side leaf spring 26C in the fourth embodiment and the upper side leaf spring 26 in the first embodiment have slightly different structures, but the function side is the same. Similarly, the lower leaf spring 28C in the fourth embodiment and the lower leaf spring 28 in the first embodiment have slightly different structures, but the function thereof is the same. That is, the upper leaf spring 26C and the lower leaf spring 28C are disposed between the lens holder 18C and the housing 12 so as to extend in the radial direction of the lens holder 18C in the direction of the optical axis O And functions as an elastic member 20C that supports the elastic member 20 so as to be displaceable. The upper leaf spring 26C and the lower leaf spring 28C are made of beryllium copper, phosphor bronze or the like.

Next, the shape memory alloy wires 32C-1 and 32C-2 for driving will be described in detail below.

Both ends of the shape memory alloy wire 32C-1 are held by a pair of electrodes 34C-1. Both ends of the shape memory alloy wire 32C-2 are held by a pair of electrodes 34C-2. The intermediate portion 32C-1a of the shape memory alloy wire 32C-1 is caught by the step projection (projection portion) 184C-1. The intermediate portion 32C-2a of the shape memory alloy wire 32C-2 is caught by the projection (protrusion) 184C-2. The shape memory alloy wires 32C-1 and 32C-2 for driving are formed linearly in the same manner as the shape memory alloy wire 32 in the first embodiment.

Next, the two pressurizing shape memory alloys 38C-1 and 38C-2 will be described in detail below.

The pressing shape memory alloy 38C-1 is disposed above the shape memory alloy wire 32C-1 and the pressing shape memory alloy 38C-2 is disposed above the shape memory alloy wire 32C-2 . A pair of alloy holding portions 382C-1 is attached to both ends of the pressing shape memory alloy 38C-1. A pair of alloy holding portions 382C-2 is attached to both ends of the pressing shape memory alloy 38C-2. The alloy holding portion 382C-1 is fitted and held in an alloy holding groove 144Ca formed in the two first electrode holder portions 144C positioned on the front side. The alloy holding portion 382C-2 is fitted and held in an alloy holding groove 144Ca formed in the two first electrode holder portions 144C located on the rear side. The intermediate shape portion 38C-1a of the pressing shape memory alloy 38C-1 is caught by two pressing pressing projections (projections) 188C-1a and 188C-1b. The intermediate shape portion 38C-2a of the pressure-applying shape memory alloy 38C-2 is engaged by two pressing hinge projections (projections) 188C-2a and 188C-2b. The pressure-application shape memory alloys 38C-1 and 38C-2 are not connected to the electrodes and thus are not energized.

The two pressure-application shape memory alloys 38C-1 and 38C-2 are formed in a coil shape. The illustrated pressure-application shape memory alloys 38C-1 and 38C-2 have a length of 3 mm, for example, in a non-stretched state (natural state). The intermediate shape portions 38C-1a and 38C-2a of the pressing shape memory alloy 38C-1 and 38C-2 are pressed against the pressing projection projections (projection portions) 188C-1a and 188C of the lens holder 18C 1b, 188C-2a, and 188C-2b, the lengths of the pressing shape memory alloys 38C-1 and 38C-2 become, for example, 7 mm. The diameter (diameter) of the wires of the compression-molding shape memory alloys 38C-1 and 38C-2 is 0.05 mm.

For this reason, in the case of being formed into a linear shape, for example, only about 4% is not shrunk, whereas when formed into a coil shape, it can be contracted by, for example, 200% or more.

The temperature of these driving shape memory alloy wires 32C-1 and 32C-2 and the pressing shape memory alloys 38C-1 and 38C-2 are increased and contracted under a high temperature environment. On the other hand, The temperature is lowered and elongated. The " high-temperature environment " referred to herein means an environment where the external temperature is about 70 ° C or more when a TiNi alloy is employed as the shape memory alloy, for example. The " room temperature environment " means an environment where the external temperature is about 70 DEG C or less when a TiNi alloy is used as the shape memory alloy, for example.

Next, the action of the lens driving section in the normal temperature environment, the high temperature environment, and the driving of the shape memory alloy wires 32C-1 and 32C-2 for driving will be described below.

First, under the normal temperature environment, since the pressing shape memory alloy 38C-1, 38C-2 is not contracted as described above, the lens moving parts 11, 18C are moved downward along the optical axis O direction And as a result, the pressing force for pressing the lens movable portions 11, 18C downward along the optical axis O direction can be adjusted.

Next, under the high-temperature environment, the shape memory alloy wires 32C-1 and 32C-2 are contracted as the temperature rises as described above. At this time, the pressurizing shape memory alloys 38C-1 and 38C-2 similarly contract and rise in temperature. At this time, toward the upper side in the direction of the optical axis O, the lens movable parts 11 and 18C are moved toward the lower side in the optical axis O direction rather than the thrust of the shape memory alloy wires 32C-1 and 32C-2 acting on the lens movable parts 11 and 18C, The thrust of the pressing shape memory alloy 38C-1 and 38C-2 acting on the movable portions 11C and 18C is increased (or becomes the same) . Thus, the pressing shape memory alloys 38C-1 and 38C-2 function as thrust force adjusting means for adjusting the thrust acting on the lens moving parts 11 and 18C.

Next, during the passage of the shape memory alloy wires 32C-1 and 32C-2, the shape memory alloy wires 32C-1 and 32C-2 rise in temperature and contract, -1, and 184C-2, the lens holder 18C is moved upward in the optical axis O direction. At this time, the pressing shape memory alloy 38C-1, 38C-2 functions only as a pressing spring that presses downward because no electric current is supplied as described above. As a result, the lens holder 18C moves upward along the optical axis O direction against the pressing force of the pressing shape memory alloy 38C-1, 38C-2 and the upper leaf spring 26C in the downward direction . On the other hand, when the energization of the shape memory alloy wires 32C-1 and 32C-2 is stopped, the shape memory alloy wires 32C-1 and 32C-2 are naturally cooled. As a result, the shape memory alloy wires 32C-1 and 32C-2 are elongated, and the downward pressing force of the pressing shape memory alloy 38C-1 and 38C-2 causes the lens holder 18C to move along the optical axis O) direction.

The lens driving apparatus 10C according to the fourth embodiment described above exhibits the following effects.

Two projections (projections) 184C-1 and 184C-2 are provided on the outer peripheral wall of the tubular portion 182C at regular angular intervals around the optical axis O, Two shape memory alloy wires 32C-1 and 32C-2 are provided in correspondence with the lens movable parts 184C-1 and 184C-2, It is possible to suppress the inclination of the lens moving parts 11 and 18C with respect to the optical axis O direction at the time of driving the lens driving device 10C.

The driving of the lens moving parts 11 and 18C by the two shape memory alloy wires 32C-1 and 32C-2 causes the driving forces required for the shape memory alloy wires 32C-1 and 32C- It is possible to secure a wider design freedom of the shape memory alloy wires 32C-1 and 32C-2.

The pressing force for pressing the lens moving parts 11 and 18C downward along the optical axis O direction under normal temperature environment is adjusted by providing the shape memory alloys 38C-1 and 38C-2 for pressing as the lens driving parts And it is also possible to prevent displacement of the lens moving parts 11 and 18C in the direction of the optical axis O under a high temperature environment.

Since the shape memory alloy wires 38C-1 and 38C-2 are formed in a coil shape, the shape of the shape memory alloy wires 32C-1 and 32C-2 in the high temperature environment is smaller than the contraction of the shape memory alloy wires 32C- The shrinkage of the memory alloys 38C-1 and 38C-2 becomes large and the driving force in the downward direction along the optical axis O becomes larger. Therefore, the displacement of the lens moving parts 11 and 18C in the optical axis O direction Can be reliably prevented.

A lens driving apparatus 10D according to a fifth embodiment of the present invention will be described with reference to Figs. 21 to 26. Fig. Fig. 21 is a perspective view obliquely from above and obliquely omitted from the lens-driving apparatus according to the fifth embodiment of the present invention, and Fig. 22 is a plan view of the lens- FIG. 23 is an exploded perspective view of the lens driving apparatus according to the fifth embodiment of the present invention, viewed obliquely from above and from above, FIG. 24 is a perspective view of the lens driving apparatus shown in FIG. 22, Fig. 25 is a side view of the lens driving apparatus shown in Fig. 22, and Fig. 26 is a top view of the lens driving apparatus shown in Fig.

The lens driving apparatus 10D of the fifth embodiment is different from the lens driving apparatus 10D of the fourth embodiment shown in Figs. 16 to 20 except that the configuration of the pressing projection and the shape memory alloy for pressing are different as described later. And operates with the same configuration as the device 10C. Therefore, the same constituent elements as those of the lens driving apparatus 10C of the fourth embodiment are denoted by the same reference numerals and their explanations are omitted, and only the differences between the fourth embodiment and the fifth embodiment will be described do.

First, the pressing projection projections 188D-1 and 188D-2, which are the first differences between the fourth and fifth embodiments, will be described.

The pressing projection 188C-1a and the pressing projection 188C-1b of the lens driving apparatus 10C according to the fourth embodiment are located above the projection 184C-1, The pressing projection 188D-1 of the lens driving device 10D is formed above the position of the locking protrusion 184C-1 at a position shifted by 90 占 about the optical axis O from the position of the locking projection 184C-1. Similarly, while the pressing projections 188C-2a and 188C-2b of the lens driving apparatus 10C according to the fourth embodiment are located above the projection 184C-2, The pressing projection 188D-2 in the lens driving apparatus 10D according to the second embodiment is formed above the position displaced 90 degrees from the position of the locking projection 184C-2 about the optical axis O. [ The pressing projection 188D-1 and the pressing projection 188D-2 are formed at positions shifted from each other by 180 占 about the optical axis O with respect to each other.

Next, the pressing shape memory alloys 38D-1 and 38D-2, which are the second difference from the fourth and fifth embodiments, will be described.

In the lens driving apparatus 10C according to the fourth embodiment, the pressing shape memory alloy 38C-1 is disposed above the shape memory alloy wire 32C-1 and has pressing projection projections 188C-1a and 188C- 1 in the lens driving apparatus 10D according to the fifth embodiment, the pressing shape memory alloy 38D-1 is located at a position shifted from the position of the shape memory alloy wire 32C-1 by 90 degrees And is hooked on the above-described pressing projection 188D-1. Similarly, in the lens driving apparatus 10C according to the fourth embodiment, the pressing shape memory alloy 38C-2 is disposed above the shape memory alloy wire 32C-2, and the pressing forcing projections 188C-2a, 2, the pressing shape memory alloy 38D-2 is displaced 90 degrees from the position of the shape memory alloy wire 32C-2 in the lens driving apparatus 10D according to the fifth embodiment, Position and is engaged with the above-described pressing projection 188D-2. The pressurizing shape memory alloy 38D-1 and the pressurizing shape memory alloy 38D-2 are disposed at positions shifted by 180 占 with respect to the optical axis O from each other. One of the pair of alloy holding portions 382D-1 attached to both ends of the pressure-applying shape memory alloy 38C-1 has one of the two first electrode holder portions 144C positioned on the front side, The other one of the pair of alloy holding portions 382D-1 is held by the two first electrode holder portions 144C located at the rear side The first electrode holder portion 144C of the first electrode holder 144C. Likewise, one of the pair of alloy holding portions 382D-2 attached to both ends of the pressing shape memory alloy 38C-2 is one of the two first electrode holder portions 144C positioned on the front side And the other one of the pair of alloy holding portions 382D-2 is held by the two first electrode holder portions 442a and 442b positioned on the rear side, Is held and held in the alloy holding groove 144Ca formed in one of the first electrode holder portions 144C of the first electrode holder portion 144C.

The lens driving apparatus 10D according to the fifth embodiment described above is different from the lens driving apparatus 10C according to the fourth embodiment in that the mounting position of the shape memory alloy wires 32C- Since the mounting positions of the shape memory alloys 38D-1 and 38D-2 are spaced apart, mounting operation of the lens driving apparatus 10D can be easily achieved.

In the present embodiment, the shape memory alloy wires 32C-1 and 32C-2 and the shape memory alloy for pressure 38D-1 and 38D-2 are disposed at positions shifted by 90 degrees with respect to the optical axis O However, this angle may be any angle.

While the present invention has been particularly shown and described with reference to the embodiments thereof, the present invention is not limited to these embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. For example, in the present invention, since the SMA assembly is attached directly to the actuator base through the electrode holder without attaching the SMA assembly directly to the actuator base, if the position of the electrode holder can be adjusted, the shape memory alloy member It is possible to easily adjust the amount of tension applied to the shape memory alloy member even after the attachment. As a result, it is possible to suppress unevenness of the product characteristics. The guide member (elastic member) is not limited to the above-described embodiment, and various members may be used.

10, 10A, 10B, 10C, 10D ... Lens driving device 11 ... Lens barrel (lens assembly)
12 ... The housing (housing) 14, 14C ... Actuator base
142, 142C ... The base portion 144 ... Base protrusion
146 ... The front concave portion 148 ... Front concave portion
144C ... The first electrode holder part 144Ca ... Alloy retention groove
146C ... The second electrode holder portion 16 ... The outer side cover
18, 18C ... The lens holders 182, 182C ... The cylindrical portion
184, 184B-1, 184B-2, 184C-1, 184C-2 ... The projecting portion (step projection)
186 ... The upper holder protrusions 186a ... The upper holder protrusion
188C-1a, 188C-1b, 188C-2a, 188C-2b ... The pressing projection (projection)
20, 20C ... Elastic member
22 ... The front supporting member (first supporting member; electrode holder)
222 ... The front base portion 224 ... The front support projection
224a ... The front support protrusions 226 ... Forward connection
226a ... The first protrusion 226b ... The second protrusion
226c ... Third protrusion
24, 24B ... The rear support member (second support member)
242 ... The rear base portions 244, 244B ... The rear support protrusions
244a ... The rear support protrusions 246, 246B ... Rear connection portion
26, 26C ... The upper plate spring 262 ... The upper-
262a ... The upper spring hole 264 ... The upper end
264a ... The upper end hole 266 ... The upper-
28, 28C ... The lower leaf spring 282 ... The lower-
284 ... The lower end 284a ... The lower end hole
286 ... The lower arm portion 30 ... My upper cover (stopper)
302 ... Inner cover body 304 ... Step projection
304a ... Through hole 306 ... The front extension
308 ... The rear extension
32, 32A, 32B-1, 32B-2, 32C-1, 32C-2, Shape memory alloy wire
32a, 32Aa, 32B-1a, 32B-2a, 32C-1a, 32C-2a, Middle part
34, 34B-1, 34B-2, 34C-1, 34C-2, Electrodes 342, 342B-1, 342B-2 ... [0040]
342a, 342B-2a ... Round hole 344 ... Connection
346 ... Terminal portion
36, 36A, 36B-1, 36B-2 ... SMA assembly
38C-1, 38C-2, 38D-1, 38D-2 ... Shape memory alloy for pressurization
382C-1, 382C-2 ... Alloy holding part o ... The optical axis of the lens
AFL ... Autofocus lens

Claims (15)

A housing for supporting the lens holder movably only in the direction of the optical axis, a moving means for moving the lens holder in the optical axis direction, a lens holder for holding the lens holder in the optical axis direction, In a direction perpendicular to the optical axis direction,
Wherein the moving means includes a shape memory alloy member extending between the lens holder and the housing, and both ends of the shape memory alloy member are attached with a pair of electrodes for energizing the shape memory alloy member,
The housing includes an actuator base disposed on a lower side of the lens holder, and first and second support members attached to the actuator base, the first and second support members being opposed to each other,
Wherein the first support member functions as an electrode holder for holding the pair of electrodes. The lens driving apparatus according to claim 1, wherein the lens holder has a projection protruding radially outward from the tubular portion and engaging an intermediate portion of the shape memory alloy member. The lens holder according to any one of claims 1 to 3, wherein the guide means comprises an elastic member disposed between the lens holder and the housing, the elastic member being movable only in the optical axis direction So as to be displaceable. 4. The lens driving apparatus according to claim 3, wherein the elastic member is constituted by an upper leaf spring and a lower leaf spring provided above and below the tubular portion of the lens holder in the optical axis direction. The lens barrel according to claim 4, wherein the upper leaf spring comprises: an upper ring portion attached to an upper end portion of the lens holder; four upper end portions attached to the housing; and four upper end portions connecting the upper ring portion and the four upper ends, And an arm portion. The lens barrel according to claim 4, wherein the lower leaf spring comprises a pair of lower leaf springs, each of the pair of lower leaf springs includes a lower arc portion attached to a lower end portion of the lens holder, A lower end of the pair and a pair of lower arm portions connecting the lower arc portion and the pair of lower ends. The lens driving apparatus according to claim 1 or 2, wherein the shape memory alloy member is formed of a shape memory alloy wire formed in a linear shape. 3. The lens driving apparatus according to claim 1 or 2, wherein the shape memory alloy member is formed of a shape memory alloy member formed in a coil shape. delete A first step of attaching the upper side leaf spring and the lower side leaf spring to both ends of the lens holder having the cylindrical portion for holding the lens barrel in the direction of the optical axis,
A second step of attaching a support member having a shape memory alloy assembly to the lens holder,
A third step of attaching the actuator base to the support member in a state that the lower leaf spring is sandwiched from the bottom side of the lens holder;
A fourth step of attaching an inner upper cover to the support member in a state that the upper leaf spring is sandwiched from the upper side of the lens holder,
And a fifth step of covering the outer top cover, the lens holder, the upper leaf spring, the lower leaf spring, the shape memory alloy assembly, and the support member,
Wherein the shape memory alloy assembly comprises a shape memory alloy member and a pair of electrodes electrically connected to both ends of the shape memory alloy member,
Wherein the lens holder has first and second sides facing each other and has a projection protruding outward from an outer wall of the tubular portion on the first side,
The shape memory alloy assembly is attached to the first support member while the pair of electrodes are held in the first support member,
The second step
Wherein the shape memory alloy member is held between the lens holder and the first support member by engaging the intermediate portion of the shape memory alloy member with the step projection to attach the first support member to the first side of the lens holder ;
And attaching the second support member to the second side of the lens holder. delete 11. The upper plate spring according to claim 10, wherein the upper leaf spring is constituted by an upper ring portion, four upper end portions provided at four corners and having an upper spring hole, and four upper arm portions connecting the upper ring portion and the four upper end portions ,
Wherein the lower leaf spring is composed of a pair of lower leaf springs, each of the pair of lower leaf springs has a lower arcuate portion, a pair of lower end portions having a lower end hole, And a pair of lower arm portions connecting the lower ends of the lower arm portions,
The first step
Attaching the upper ring portion of the upper leaf spring to an upper end portion of the cylindrical portion of the lens holder;
And attaching the lower arcuate portion of the pair of lower leaf springs to a lower end portion of the cylindrical portion of the lens holder. 13. The image forming apparatus according to claim 12, wherein each of the first and second support members has a pair of support protrusions at both end sides thereof, each of the pair of support protrusions has a support protrusion at the top,
And the second step includes the step of fitting the support protrusions of the first and second support members into the upper end holes of the four upper ends of the upper leaf spring . 14. The apparatus according to claim 13, wherein the actuator base has a ring-shaped base portion and four base protrusions protruding upward from four corners of the base portion, wherein the four base protrusions have four base protrusions Lt; / RTI &
Wherein the fourth step includes the steps of, in a state in which four base protrusions formed on the four base protrusions of the actuator base are respectively passed through a lower end hole formed in the pair of lower ends of the pair of lower leaf springs, And the four base protrusions of the base are attached to the pair of support protrusions of the first and second support members, respectively. 15. The apparatus according to claim 14, wherein the inner top cover comprises a ring-shaped inner cover main body, and four step protruding portions projecting downward from four corners of the inner cover main body, have,
And the fourth step is characterized in that the support protrusions of the first and second support members protruding through the upper end holes of the upper end portions of the upper plate spring are respectively formed on the four step protrusions of the inner upper cover Wherein the inner cover is attached to the first and second support members in a state where the inner cover is inserted into the through hole.

Images