JP2014228650A - Lens driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens driving device for improving a thrust for driving a lens holding member.SOLUTION: A lens driving device 101 includes: a yoke 14 having a cylindrical outer wall part 14A having a plurality of corner parts; a plurality of magnets 15 respectively arranged inside the plurality of corner parts of the yoke 14; a cylindrical lens holding member 12 disposed inside the yoke 14 capable of holding a lens body; a coil 13 annually wound around the lens holding member 12; and an elastic member 16 for supporting the lens holding member 12 movably in an optical axis direction. A gap SM is formed between the outer wall part 14A at the corner part and the magnet 15, and the gap SM is packed with adhesive A7 with which a magnetic substance is mixed, and the magnet 15 is adhered and fixed to an inside surface 14p of the outer wall part 14A with the adhesive A7.

Description

  The present invention relates to a lens driving device mounted on a mobile device with a camera, for example.

  In recent years, it has become common for camera devices to be mounted on portable devices typified by mobile phones. In addition to the demand for downsizing, the lens driving device, which is the main part of the camera mechanism mounted on this small portable device, has been increasingly demanded to drive the lens body with high accuracy. As a lens driving device that should satisfy these two requirements, a device in which a magnetic circuit for driving the lens holder is provided on all four sides of the lens holder is well known.

  As the lens driving device described above, Patent Document 1 (conventional example) proposes a lens driving device 900 as shown in FIGS. FIG. 21 is an exploded perspective view for explaining a conventional lens driving device 900. 22A and 22B are diagrams for explaining a conventional lens driving device 900. FIG. 22A is a perspective view showing an appearance, and FIG. 22B is a Z2 side shown in FIG. FIG. 5 is a bottom view as viewed from above, in which a base member 901, a lens holder (lens holding member) 903, a coil 904, a lower leaf spring 906, and a spacer member 909 are omitted.

  The lens driving device 900 shown in FIGS. 21 and 22A includes a base member 901 in which a metal plate member is embedded, a lens holding body 903 that can hold a lens body (not shown), and a coil 904 wound with a metal wire. And four magnets 905, a lower leaf spring (elastic member) 906 disposed below the lens holder 903 (Z2 side shown in FIG. 21), and above the lens holder 903 (Z1 side shown in FIG. 21). ) Disposed on the upper plate spring (elastic member) 907, a yoke 908 made of a metal plate material, and a spacer member 909 formed in an annular shape.

  The lens driving device 900 holds a lens body (not shown) on the lens holder 903, is attached to a substrate on which an imaging element (not shown) is mounted, and the lens held by the lens body is attached to the imaging element with an optical axis. The focal distance can be adjusted by driving in the direction (Z direction shown in FIG. 22A). At that time, a magnetic circuit is formed by the four magnets 905 (see FIG. 22B) arranged at the four corners of the yoke 908, the coil 904, and the yoke 908, and the electromagnetic force generated when the coil 904 is energized. The lens holder 903 is moved along the optical axis direction.

Utility Model Registration No. 3179634

  However, in order to bring the magnet 905 into close contact with the inner surface 908p of the yoke 908, a gap GP is provided between the magnet 905 at the four corners of the yoke 908 as shown in FIG. For this reason, as the magnetic field flow in the gap GP stagnate, a magnetic loss occurs, the magnetic flux density in the magnetic circuit is lowered, and the thrust for driving the lens holder 903 is weakened. In the future, as the size of products to be applied has been increasingly reduced, there has been a problem that this thrust must be secured even a little while reducing the size of the lens driving device.

  The present invention solves the above-described problems, and an object thereof is to provide a lens driving device with improved thrust for driving a lens holding member.

  In order to solve this problem, a lens driving device according to the present invention includes a yoke having a cylindrical outer wall portion having a plurality of corner portions, and a plurality of portions disposed inside the plurality of corner portions of the yoke. A magnet, a cylindrical lens holding member disposed inside the yoke and capable of holding the lens body, a coil wound in an annular shape around the lens holding member, and moving the lens holding member in the optical axis direction An elastic member that can be supported, and a gap between the outer wall portion and the magnet in the corner portion, and an adhesive mixed with a magnetic material is filled in the gap. The magnet is adhered and fixed to the inner side surface of the outer wall portion by the adhesive.

  According to this, in the lens driving device of the present invention, in the magnetic field flow (magnetic path) flowing through the outer wall portion, the gap, the magnet, and the coil at the corner of the yoke, the flow of the magnetic field in the gap portion does not stagnate. The occurrence of magnetic loss can be suppressed. As a result, the magnetic flux density in the magnetic circuit is improved, and the thrust for driving the lens holding member can be improved.

  The lens driving device of the present invention is characterized in that the magnetic body is iron powder.

  According to this, since the magnetic body is iron having a high magnetic permeability, the magnetic permeability of the adhesive layer mixed with the magnetic body is increased. Thereby, the magnetic flux density in the magnetic circuit can be further improved, and the thrust for driving the lens holding member can be further improved.

  In the lens driving device according to the present invention, the yoke includes a ceiling portion provided continuously with the upper end of the outer wall portion and having an opening, and a plurality of inner yokes extending downward from a part of the ceiling portion. And the inner yoke is disposed opposite to the plurality of magnets with the coil interposed therebetween.

  According to this, since the inner yoke is arranged opposite to each of the plurality of magnets with the coil interposed therebetween, a magnetic field flow (magnetic path) that flows between the outer wall portion of the yoke, the magnet, the coil, the inner yoke, and the ceiling portion is formed. . As a result, the direction of the magnetic field intersecting with the coil is determined, a stable thrust can be obtained, and the lens holding member can be driven stably.

  In the lens driving device of the present invention, in the magnetic field flow (magnetic path) flowing through the outer wall portion, the gap, the magnet, and the coil at the corner portion of the yoke, the magnetic field flow in the gap portion does not stagnate and magnetic loss occurs. Can be suppressed. As a result, the magnetic flux density in the magnetic circuit is improved, and the thrust for driving the lens holding member can be improved.

It is a disassembled perspective view explaining the lens drive device of 1st Embodiment of this invention. FIGS. 2A and 2B are diagrams illustrating the lens driving device according to the first embodiment of the present invention, in which FIG. 2A is a perspective view of the lens driving device, and FIG. 2B is Y2 shown in FIG. It is the front view seen from the side. 3A and 3B are diagrams illustrating the lens driving device according to the first embodiment of the present invention, in which FIG. 3A is a top view seen from the Z1 side shown in FIG. 2A, and FIG. It is the bottom view seen from the Z2 side shown to Fig.2 (a). FIG. 4A is a perspective view illustrating the lens driving device according to the first embodiment of the present invention, and FIG. 4A is a view in which the top cover is omitted from the perspective view shown in FIG. 2, and FIG. It is the figure which abbreviate | omitted the upper leaf | plate spring and the yoke in the perspective view shown to Fig.4 (a). FIG. 5 is a diagram illustrating the lens driving device according to the first embodiment of the present invention, and FIG. 5A is a bottom view in which the base member is omitted from the bottom view shown in FIG. These are the bottom views which abbreviate | omitted the lower leaf | plate spring and the lens holding member in the bottom view shown to Fig.5 (a). FIG. 6A is a perspective view of a lens holding member, and FIG. 6B is a view showing a coil wound around the lens holding member, illustrating the lens driving device according to the first embodiment of the present invention. FIG. FIG. 7A is a diagram illustrating the lens driving device according to the first embodiment of the present invention, and FIG. 7A is a bottom view of the yoke viewed from the Z2 side shown in FIG. These are the perspective views of the yoke seen from the Z2 side shown to Fig.2 (a). It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is sectional drawing in the VIII-VIII line shown to Fig.3 (a). It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is an expanded sectional view of the P section shown in FIG. FIG. 10A is a diagram illustrating an elastic member in the lens driving device according to the first embodiment of the present invention, and FIG. 10A is a top view of the upper leaf spring viewed from the Z1 side shown in FIG. b) is a top view of the lower leaf spring viewed from the Z1 side shown in FIG. It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: Fig.11 (a) is a perspective view of a base member, FIG.11 (b) assembled | attached the lower leaf | plate spring to the base member. It is a perspective view of a state. FIGS. 12A and 12B are diagrams illustrating a top cover in the lens driving device according to the first embodiment of the present invention, in which FIG. 12A is a top perspective view seen from the Z1 side shown in FIG. 1, and FIG. FIG. 2 is a bottom perspective view seen from the Z2 side shown in FIG. It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is sectional drawing in the XIII-XIII line | wire shown in FIG. It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is an expanded sectional view of the Q section shown in FIG. It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is sectional drawing in the XV-XV line | wire shown in FIG. It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is an expanded sectional view of R part shown in FIG. It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is sectional drawing in the XVII-XVII line | wire shown in FIG. It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is an expanded sectional view of the S section shown in FIG. FIG. 19A is a diagram showing a state in which a lens holding member is placed on a base member in the lens driving device according to the first embodiment of the present invention, and FIG. 19A is from the X1 side shown in FIG. FIG. 19B is an enlarged view of a part of the oblique side view viewed from the corner side in front of the paper surface shown in FIG. It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is an expansion perspective view of T part shown to Fig.4 (a). It is a disassembled perspective view explaining the lens drive device 900 of a prior art example. FIG. 22A is a perspective view showing an external appearance, and FIG. 22B is a bottom view seen from the Z2 side shown in FIG. 22A. In the figure, a base member 901, a lens holder (lens holding member) 903, a coil 904, a lower leaf spring 906, and a spacer member 909 are omitted.

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

[First Embodiment]
FIG. 1 is an exploded perspective view illustrating the lens driving device 101 according to the first embodiment of the present invention. 2A and 2B are diagrams for explaining the lens driving device 101 according to the first embodiment of the present invention. FIG. 2A is a perspective view of the lens driving device 101, and FIG. It is the front view seen from the Y2 side shown to (a). FIG. 3 is a diagram illustrating the lens driving device 101 according to the first embodiment of the present invention. FIG. 3A is a top view seen from the Z1 side shown in FIG. (B) is the bottom view seen from the Z2 side shown to Fig.2 (a). For ease of explanation, the magnet 15 in FIG. 1 shows a state where the adhesive A7 is applied, and the adhesive A7 is indicated by hatching.

  As shown in FIGS. 1 to 3, the lens driving device 101 according to the first embodiment of the present invention includes a cylindrical lens holding member 12 that can hold a lens body (not shown), and a lens holding member 12. A coil 13 wound in an annular shape around the periphery, a yoke 14 having a cylindrical outer wall portion 14A having a plurality of corners, a plurality of magnets 15 disposed respectively inside the yoke 14, and a lens holding member 12 And an elastic member 16 that is movably supported in the optical axis direction. Furthermore, the top cover 19 arrange | positioned above the elastic member 16 (16A) and the base member 18 with which the terminal 7 was embedded are provided. The elastic member 16 includes an upper leaf spring 16A fixed to the upper portion of the yoke 14 and the upper portion of the lens holding member 12, and two lower leaf springs (16C, 16E) fixed to the lower portion of the lens holding member 12. It is configured with.

  The lens driving device 101 holds a lens body (not shown) on the lens holding member 12 and is mounted on a substrate on which an imaging element (not shown) is mounted. Then, in order to adjust the focal length by driving the lens held by the lens body in the optical axis direction (Z direction shown in FIG. 2A) with respect to the image sensor, the coil 13 is energized from the power source. The lens holding member 12 is moved along the optical axis direction by electromagnetic force generated by energization.

  Next, each component will be described. FIG. 4 is a perspective view illustrating the lens driving device 101 according to the first embodiment of the present invention. FIG. 4A is a diagram in which the top cover 19 is omitted from the perspective view shown in FIG. 4 (b) is a diagram in which the upper leaf spring 16A and the yoke 14 are omitted from the perspective view shown in FIG. 4 (a). FIG. 5 is a diagram illustrating the lens driving device according to the first embodiment of the present invention, and FIG. 5A is a bottom view in which the base member 18 is omitted from the bottom view shown in FIG. FIG. 5B is a bottom view in which the lower leaf springs (16C, 16E) and the lens holding member 12 are omitted from the bottom view shown in FIG. 6A and 6B are diagrams illustrating the lens driving device according to the first embodiment of the present invention. FIG. 6A is a perspective view of the lens holding member 12, and FIG. 6B is a lens holding member. 12 is a perspective view in which a coil 13 is wound around 12. FIG. 7 is a diagram for explaining the lens driving device according to the first embodiment of the present invention. FIG. 7A is a bottom view of the yoke 14 as viewed from the Z2 side shown in FIG. FIG. 7B is a perspective view of the yoke 14 viewed from the Z2 side shown in FIG. FIG. 8 is a diagram illustrating the lens driving device 101 according to the first embodiment of the present invention, and is a cross-sectional view taken along line VIII-VIII shown in FIG. The sectional view of FIG. 8 shows a state when the lens holding member 12 is disposed at the lowest position (Z2 direction shown in FIG. 8). FIG. 9 is a diagram for explaining the lens driving device according to the first embodiment of the present invention, and is an enlarged cross-sectional view of a portion P shown in FIG. For ease of explanation, the magnet 15 in FIG. 4B shows a state in which the adhesive A7 is applied, and the adhesive A7 is indicated by hatching. FIG. 9 also shows a state in which the adhesive SM is filled between the gap SM between the magnet 15 and the outer wall portion 14A of the yoke 14 and between the magnet 15 and the ceiling portion 14B of the yoke 14. In addition, the adhesive A7 is indicated by hatching.

  The lens holding member 12 is made of a liquid crystal polymer (LCP) and is formed in a cylindrical shape as shown in FIGS. 1, 4 and 6, and has a circular outer peripheral surface and an inner peripheral surface. 12s and a flange portion 12v protruding radially outward from the outer peripheral surface of the lower end (Z2 side shown in FIG. 6) of the cylindrical portion 12s, and disposed above the base member 18 and inside the yoke 14. ing. Further, a female screw portion 12n is formed on the inner peripheral surface of the cylindrical portion 12s, and a lens body (not shown) is mounted and held on the female screw portion 12n.

  In addition, as shown in FIG. 6, coil support portions 12j that support the coil 13 from the inside are equally provided at four locations on the outer peripheral surface of the cylindrical portion 12s, and a flange portion 12v is provided at one end side of the coil support portion 12j. A flange 12h that protrudes outward in the radial direction is formed. Further, on the outer peripheral surface of the cylindrical portion 12s further above the flange portion 12h, four pedestal portions 12d are formed diagonally facing each other, and the pedestal portion 12d and the upper leaf spring 16A are fixed with an adhesive. The

Further, as shown in FIG. 5A, the bottom surface of the lens holding member 12 has six column-shaped projecting portions 12t protruding downward (front side of the paper surface of FIG. 5A) (12t _1). , 12t ₂ , 12t ₃ , 12t ₄ , 12t ₅ , 12t ₆ ) and are engaged with the two lower leaf springs (16C, 16E). Further, as shown in FIG. 5A, the bottom surface of the lens holding member 12 has two rectangular protrusions 12f (12f ₁ , 12f) that protrude downward (front side of the paper surface of FIG. 5A). ₂₎ together are provided, a cylindrical convex portion 12g is two places _(12g 1, 12g ₂₎ are provided. Then, out with protrusion 12f ₂ and two protrusions _{12g (12g 1, 12g 2)} , are arranged such that the triangle.

  As shown in FIG. 1, FIG. 4B and FIG. 5B, the coil 13 is formed by winding a conducting wire having an annular shape and an octagonal angle. Of the octagonal shape, the four opposing sides are bent into an arc shape, and the other four opposing sides are formed in a straight line. Further, as shown in FIGS. 4B and 6B, the coil 13 is disposed at a position surrounding the periphery of the cylindrical portion 12s of the lens holding member 12, and is supported from the inside by the coil support portion 12j. In the state, a part of the coil 13 is fixed to the upper surface of the flange 12v so that the coil 13 is sandwiched between the flange 12h and the flange 12v. The portions in contact with the coil support portion 12j are four straight sides. Since the inner peripheral surface 13p of the coil 13 is supported in an isotropically balanced manner by the coil support portion 12j, the lens holding member 12 is brought into contact with the central axis of the coil 13 and the central axis of the lens holding member 12. Retained. Thereby, it becomes easy to easily match the center axis of the lens held by the female screw portion 12n of the lens holding member 12 with the optical axis of the lens body.

  As shown in FIGS. 1 to 5 (excluding FIG. 4 (b)) and FIG. 7, the yoke 14 is formed in a box shape to form a case, and includes a lens holding member 12, a coil 13, These members are accommodated in the accommodating portion 14s shown in FIG. 7 so as to cover the magnet 15 and the elastic member 16. The yoke 14 is engaged with the base member 18 and integrated with the base member 18. Further, as shown in FIG. 7, the case-like yoke 14 includes a cylindrical outer wall portion 14 </ b> A and a flat plate-like ceiling portion 14 </ b> B provided continuously with the upper end (Z1 side shown in FIG. 11) of the outer wall portion 14 </ b> A. And four inner yokes 14C extending downward (Z2 direction shown in FIG. 2) from a part of the opening 14k formed in the ceiling portion 14B.

  Further, as shown in FIGS. 3, 5 and 7A, the outer wall portion 14A has a rectangular shape in plan view, and the inner yoke 14C has the shape shown in FIGS. 5B and 7A. As shown in the plan view, it is formed in an arc shape in plan view, and is arranged at equal intervals so as to face the four corners of the outer wall portion 14A.

  Further, when the lens driving device 101 is assembled, each of the inner yokes 14C is disposed along the outer peripheral surface of the cylindrical portion 12s of the lens holding member 12, and FIG. 5B, FIG. 8 and FIG. As shown in FIG. 9, the coil 13 is disposed to face the inner peripheral surface 13 p. Furthermore, each of the inner yokes 14 </ b> C is disposed opposite to each of the magnets 15 with the coil 13 interposed therebetween. When the yoke 14 is manufactured by drawing, the inner yoke 14C of the yoke 14 has an arc shape, so that the drawing can be easily performed. For this reason, the accuracy of the shape and arrangement position of the inner yoke 14C of the yoke 14 can be increased.

  As shown in FIG. 1, the magnet 15 has a trapezoidal cross-sectional shape and a flat outer shape, and the four magnets 15 (15A, 15B, 15C, 15D) are shown in FIG. 5 (b), FIG. 8 and FIG. 9, it is located outside the coil 13, and is disposed opposite to the four inner yokes 14C of the yoke 14 with the coil 13 in between, and is arranged at the four corners of the yoke 14. Are arranged in minutes.

  Further, the two inclined outer surfaces 15v in the trapezoidal shape of the magnet 15 have a shape along the outer wall portion 14A. For this reason, when assembling the lens driving device 101, the two outer surfaces 15v can be pressed against the inner surface 14p of the outer wall portion 14A, and can be arranged inside the plurality of corner portions of the yoke 14, respectively. Can be easily positioned.

  Further, when the lens driving device 101 is assembled, a gap SM is formed between the outer wall portion 14A and the magnet 15 at the corners of the four corners of the yoke 14, as shown in FIGS. Have. The gap SM is filled with an adhesive A7, and the magnet 15 is bonded and fixed to the inner side surface 14p of the outer wall portion 14A by the adhesive A7.

  The adhesive A7 used here is one in which a magnetic material is dispersed and mixed in a synthetic resin matrix. Thereby, in the magnetic field flow (magnetic path) flowing through the outer wall portion 14A, the gap SM, the magnet 15, and the coil 13 at the corner portion of the yoke 14, the magnetic field flow in the gap SM portion is not stagnated, and the magnetic loss is reduced. Occurrence can be suppressed. Thereby, the magnetic flux density in the magnetic circuit can be improved.

  In the first embodiment of the present invention, iron powder is used as the magnetic material. Thereby, since iron is a material with high magnetic permeability, the magnetic permeability of the layer of the adhesive A7 mixed with the magnetic material is increased. As a result, the magnetic flux density in the magnetic circuit can be further improved.

  In the first embodiment of the present invention, as described above, the yoke 14 has the inner yoke 14 </ b> C, and the inner yoke 14 </ b> C is disposed opposite to the plurality of magnets 15 with the coil 13 interposed therebetween. . For this reason, the flow (magnetic path) of the magnetic field which flows with the outer wall part 14A of the yoke 14, the magnet 15, the coil 13, the inner yoke 14C, and the ceiling part 14B is formed. As a result, the direction of the magnetic field intersecting with the coil 13 is determined, and a stable thrust can be obtained.

  Further, by providing the inner yoke 14 </ b> C in the yoke 14, the magnetic flux density in the magnetic circuit can be improved, and the thrust for driving the lens holding member 12 can be improved. On the other hand, it is not necessary to increase the size of the magnet 15 in order to obtain the same thrust, and the lens driving device 101 that can obtain a desired thrust can be made lighter.

  Next, other component parts will be described. FIG. 10 is a diagram illustrating the elastic member 16 in the lens driving device according to the first embodiment of the present invention. FIG. 10A is a top view of the upper leaf spring 16A as viewed from the Z1 side shown in FIG. FIG. 10B is a top view of the lower leaf springs (16C, 16E) viewed from the Z1 side shown in FIG. 11A and 11B are views for explaining the lens driving device according to the first embodiment of the present invention. FIG. 11A is a perspective view of the base member 18, and FIG. It is a perspective view of the state which assembled | attached the lower side leaf | plate spring (16C, 16E). FIG. 12 is a view for explaining the top cover 19 in the lens driving device according to the first embodiment of the present invention. FIG. 12 (a) is a top perspective view seen from the Z1 side shown in FIG. 12 (b) is a bottom perspective view seen from the Z2 side shown in FIG.

  The elastic member 16 is manufactured by processing a plate made of a copper alloy, and has an opening larger in diameter than the inner peripheral surface of the cylindrical portion 12s of the lens holding member 12, as shown in FIG. 1 and FIG. 4A, the upper leaf spring 16A disposed between the yoke 14 and the top cover 19, and the lens holding member 12 as shown in FIG. 1 and FIG. The lower plate spring 16C and the lower plate spring 16E are disposed between the base member 18 and placed on the base member 18. Then, each of the lens holding member 12 and the elastic member 16 (16A, 16C, 16E) is engaged, and the lens holding member 12 can be moved in the optical axis direction (Z direction shown in FIG. 2). The member 12 is supported in the air.

  The upper leaf spring 16A of the elastic member 16 has a rectangular shape as shown in FIG. 10 (a), and the first portion 16a fixed to the lens holding member 12 is fixed to the four locations and the yoke 14 side. The four second portions 16b and the four elastic arm portions 16p located between the first portion 16a and the second portion 16b connect the four first portions 16a to the elastic arm portions 16p. A crosspiece 16d connected to one end and a fixed connecting portion 16e that connects the four second portions 16b are provided.

  When the upper leaf spring 16A is incorporated in the lens driving device 101, as shown in FIG. 4A, the upper leaf spring 16A is placed on the yoke 14, and the second portion 16b of the upper leaf spring 16A is a corner of the yoke 14. The through hole 16f of the second portion 16b shown in FIG. 10A and the through hole 14f of the yoke 14 shown in FIG. 7 overlap each other. Further, the first portion 16 a of the upper leaf spring 16 </ b> A shown in FIG. 10A is placed on the pedestal portion 12 d of the lens holding member 12. Then, the first portion 16a of the upper leaf spring 16A and the pedestal portion 12d are fixed with an adhesive.

  As shown in FIG. 10B, the lower leaf spring 16C of the elastic member 16 has a half-moon inner shape, three first portions 16h engaged with the lens holding member 12, and a base member. 18 is engaged with two second portions 16i, and two elastic arm portions 16q located between the first portion 16h and the second portion 16i connect the two first portions 16h. It has the 1st fixed connection part 16g and the 2nd fixed connection part 16j which connects the 2nd part 16i of two places.

When the lower leaf spring 16C is incorporated in the lens driving device 101, as shown in FIG. 5A, the three protruding portions 12t (12t ₁ , 12t ₂ , 12t ₃ ) of the lens holding member 12 are formed. 10B, the first portion 16h shown in FIG. 10B is inserted into and fitted into the three through holes 16k, and is positioned and fixed to the lens holding member 12. Moreover, the lower leaf spring 16C can be more securely fixed to the lens holding member 12 by performing heat caulking using the protruding portions 12t (12t ₁ , 12t ₂ , 12t ₃ ).

When the lower leaf spring 16C is incorporated in the lens driving device 101, two of the through holes 16m of the second portion 16i shown in FIG. 10B are formed on the base as shown in FIG. and fitted with two projecting portions 18t projecting upward is provided on the upper surface of the member 18 _(18t 1, 18t _2), which is positioned on the base member 18 is fixed.

  Similarly to the lower leaf spring 16C, the lower leaf spring 16E of the elastic member 16 has a half-moon inner shape and is fixed to the lens holding member 12 as shown in FIG. 10B. Are two locations, two second portions 16w fixed to the base member 18, two elastic arm portions 16r located between the first portion 16v and the second portion 16w, and three first portions. It has the 1st fixed connection part 16x which connects each of the part 16v, and the 2nd fixed connection part 16y which connects the 2nd part 16w of two places.

When the lower leaf spring 16E is incorporated into the lens driving device 101, as shown in FIG. 5A, the three convex portions 12t (12t ₄ , 12t ₅ , 12t ₆ ) of the lens holding member 12 are formed. 10B, the three portions of the through hole 16z of the first portion 16v shown in FIG. 10B are inserted and fitted, and the lens holding member 12 is positioned and fixed. Further, similarly to the lower leaf spring 16C, the lower leaf spring 16C is more securely fixed to the lens holding member 12 by performing heat caulking using the projecting portions 12t (12t ₄ , 12t ₅ , 12t ₆ ). can do.

When the lower leaf spring 16E is incorporated into the lens driving device 101, the two through holes 16n of the second portion 16w shown in FIG. 10B are similar to those shown in FIG. As shown in b), the base member 18 is positioned and fixed by fitting with two projecting portions 18t (18t ₃ and 18t ₄ ) provided on the upper surface of the base member 18 and projecting upward.

  Further, as shown in FIG. 10 (b), the lower leaf spring 16C and the lower leaf spring 16E have a substantially point-symmetric shape, and at three locations of the first portion 16h and the first portion 16v, It is connected to the lens holding member 12 at an equal position, and is connected to the base member 18 at an equal position at two locations of the second portion 16i and the second portion 16w. Thereby, the lens holding member 12 can be supported in the air with good balance.

  Further, as shown in FIG. 5A, the lower leaf spring 16C is electrically connected to one end side of the coil 13 (the portion CN1 shown in the figure), and the lower leaf spring 16E is shown in FIG. As shown to a), it is electrically connected with the other end side of the coil 13 (part of CN2 shown in the figure). The coil 13 and the lower leaf springs (16C, 16E) are easily connected by solder or the like. Further, the lower leaf spring 16C is electrically connected to the terminal 7C at a portion of the through hole 16s shown in FIG. 11B, and the lower leaf spring 16E is a portion of the through hole 16t shown in FIG. 11B. Is electrically connected to the terminal 7E. Thereby, an electric current can be sent through the coil 13 through the lower leaf spring 16C and the lower leaf spring 16E. The lower leaf springs (16C, 16E) and the terminals 7 (7C, 7E) are easily connected by welding or the like.

  As shown in FIGS. 1 and 12, the top cover 19 has a frame shape having a rectangular opening 19k at the center. As shown in FIG. 2, the top cover 19 is located above the upper leaf spring 16A (FIG. 2). The upper leaf spring 16 </ b> A is sandwiched between the ceiling portion 14 </ b> B of the yoke 14 and the top cover 19.

  Further, on the lower surface side (the surface on the Z2 side shown in FIG. 1) of the top cover 19, as shown in FIG. 12B, there are four convex portions 19t protruding downward (in the Z2 direction shown in FIG. 12). A recessed portion 19r is formed which is formed at a location and falls from the periphery of the top cover 19 to the opening 19k. When the top cover 19 is incorporated in the lens driving device 101, the four convex portions 19t are formed by the through holes 16f of the second portion 16b shown in FIG. 10A and the yoke shown in FIG. 14 through the through hole 14f, the top cover 19 is engaged with the yoke 14, and the upper leaf spring 16A is positioned and fixed. Further, the concave portion 19r allows deformation of the elastic arm portion 16p of the upper leaf spring 16A, and thus allows the lens holding member 12 to move upward.

  Finally, the base member 18 will be described in detail. FIG. 13 is a diagram illustrating the lens driving device 101 according to the first embodiment of the present invention, and is a cross-sectional view taken along line XIII-XIII shown in FIG. FIG. 14 is a diagram illustrating the lens driving device according to the first embodiment of the present invention, and is an enlarged cross-sectional view of a Q portion shown in FIG. FIG. 15 is a diagram illustrating the lens driving device 101 according to the first embodiment of the present invention, and is a cross-sectional view taken along line XV-XV shown in FIG. FIG. 16 is a diagram for explaining the lens driving device according to the first embodiment of the present invention, and is an enlarged cross-sectional view of a portion R shown in FIG. FIG. 17 is a diagram illustrating the lens driving device 101 according to the first embodiment of the present invention, and is a cross-sectional view taken along line XVII-XVII shown in FIG. FIG. 18 is a diagram illustrating the lens driving device according to the first embodiment of the present invention, and is an enlarged cross-sectional view of a portion S shown in FIG. FIG. 19 is a diagram showing a state in which the lens holding member 12 is placed on the base member 18 in the lens driving device according to the first embodiment of the present invention. FIG. 19B is a side view seen from the X1 side, and FIG. 19B is an enlarged view of a part of the oblique side view seen from the corner side in front of the paper shown in FIG. FIG. 20 is a diagram for explaining the lens driving device according to the first embodiment of the present invention, and is an enlarged perspective view of a T portion shown in FIG. For ease of explanation, the yoke 14 in FIG. 4A is omitted.

  The base member 18 is made of the same liquid crystal polymer (LCP) as the lens holding member 12, and as shown in FIGS. 1 and 11A, a base 18b having a rectangular plate shape and a base 18b. And a circular opening 18k formed in the center of the.

  Moreover, it has the base part 18d formed extending from the base part 18b of the base member 18 upward (Z1 direction of Fig.11 (a)). The base portion 18d is housed in the housing portion 14s of the yoke 14, and the outer peripheral side surface 18p of the base portion 18d and the inner side surface 14p of the yoke 14 come into contact with each other. Thereby, positioning of the yoke 14 and the base member 18 is performed.

Further, on the upper surface of the base portion 18d, four projecting portions 18t (18t ₁ , 18t ₂ , 18t ₃ , 18t ₄ ) projecting upward are provided at four corners, and above (FIG. 11 ( prismatic projections 18f are opposed to two places which protrudes in the Z1 direction) of a) _(18f 1, 18f ₂₎ are provided. Further, the cylindrical protrusion 18g is provided at two locations to face _(18g 1, 18g _2), convex portions 18h protruding upward (Z1 direction in FIG. 11 (a)) is to face 2 Locations (18h ₁ , 18h ₂ ) are provided. As shown in FIG. 11, the protrusion 18f ₂ and the two protrusions 18g (18g ₁ , 18g ₂ ) are arranged in a triangular arrangement, and the protrusion 18f ₁ and the two protrusions 18g ₁ The projecting portions 18h (18h ₁ , 18h ₂ ) are arranged in a triangular arrangement.

When the lens holding member 12 movable in the optical axis direction is held at the lowest position (Z2 direction shown in FIG. 13), the protrusion 18f of the base member 18 is shown in FIGS. ₂ and the two convex portions 18g (18g ₁ , 18g ₂ ), and the projection 12f ₂ of the lens holding member 12 and the three convex portions 12g (12g ₁ , 12g ₂ ) come into contact with each other. become. As a result, the base member 18 supports the lens holding member 12 in a balanced manner at three points, and even if the lens driving device 101 receives an impact due to dropping or the like, the impact can be received in a balanced manner.

Further, when the lens holding member 12 is placed on the base member 18, as shown in FIGS. 15 and 17 through 19, the projection 12f ₁ of the projection 18f ₁ and the lens holding member 12 of the base member 18 Are opposed to each other with a gap GP, and the two projecting portions 18h (18h ₁ , 18h ₂ ) of the base member 18 and the bottom portion 12p of the lens holding member 12 (shown in FIG. 5A) define the gap GP. Have opposites. Accordingly, the lens driving device 101 is subjected to an impact in drop or the like, even if not fully supported at three points of the projection 18f ₂ and two protrusions 18g of the base member 18 _(18g 1, 18g _2), the base member The lens holding member 12 is supported in a well-balanced manner at three points of the 18 protrusions 18f ₁ and the two protruding portions 18h (18h ₁ , 18h ₂ ), and the impact can be received in a well-balanced manner.

  Further, as shown in FIGS. 1 and 11, a terminal 7 made of a metal plate made of a material such as copper, iron, or an alloy containing them as a main component is embedded in the base member 18 by insert molding. Each of the two electrically insulated terminals 7 (terminal 7C and terminal 7E) is electrically connected to a substrate on which an imaging element (not shown) is mounted, and can supply power (see FIG. 13). It is like that. One terminal 7C of the terminal 7 is electrically connected to the lower leaf spring 16C, and the other terminal 7E of the terminal 7 is electrically connected to the lower leaf spring 16E. A current can be passed from the terminal 7E to the coil 13 via the lower leaf spring 16C and the lower leaf spring 16E.

  Further, as shown in FIGS. 1 and 11, the base member 18 has a connection member 57 made of a metal plate using a material such as copper, iron, or an alloy containing them as a main component, like the terminal 7. It is insert-molded and embedded (see FIGS. 15 to 18), and a part of the connection member 57 is partially exposed at the four corners as shown in FIGS. Then, after the inner side surface 14p of the outer wall portion 14A of the yoke 14 and the outer peripheral side surface 18p of the base member 18 are positioned and combined, four joints between the connection member 57 of the base member 18 and the four corners of the yoke 14 are welded. The yoke 14 is fixed to the base member 18. Thereby, the yoke 14 is integrated with the base member 18. The yoke 14 is grounded to the ground.

  Moreover, in 1st Embodiment of this invention, as shown in FIG.19 and FIG.20, two inclination parts 18s are in the edge part side (Y1 side and Y2 side shown in FIG. 11) which the base member 18 opposes. Is formed. However, in FIG. 20, the inclined portion 18s on the Y1 side is on the rear side of the page and is not shown. By providing the inclined portion 18s, the end portion 14t of the outer wall portion 14A formed on the open side of the yoke 14 shown in FIG. 7 comes into contact with the inclined portion 18s with priority. As a result, it is possible to prevent the inner side surface 14p of the yoke 14 from hitting an undesired place on the outer peripheral side surface 18p of the base portion 18d and to improve the positioning accuracy.

  In the lens driving device 101 configured as described above, after the upper leaf spring 16A and the yoke 14 are assembled to the top cover 19 shown in FIG. 12, the lens holding member 12, the coil 13, the magnet 15, and the lower leaf spring (16C 16E) are sequentially accommodated in the accommodating portion 14s of the yoke 14 shown in FIG. Further, the base member 18 is assembled to the yoke 14 and integrated with the yoke 14.

  The effects of the lens driving device 101 according to the first embodiment of the present invention configured as described above will be described below.

  In the lens driving device 101 according to the first embodiment of the present invention, a gap SM located between the outer wall portion 14A and the magnet 15 at the corner of the yoke 14 is filled with an adhesive A7 mixed with a magnetic material. For this reason, in the magnetic field flow (magnetic path) flowing through the outer wall portion 14A, the gap SM, the magnet 15, and the coil 13 at the corner portion of the yoke 14, the magnetic field flow in the gap SM portion does not stagnate and the magnetic loss is reduced. Occurrence can be suppressed. Thereby, the magnetic flux density in the magnetic circuit is improved, and the thrust for driving the lens holding member 12 can be improved.

  In addition, since the magnetic material is iron with high magnetic permeability, the magnetic permeability of the layer of the adhesive A7 mixed with the magnetic material is increased. Thereby, the magnetic flux density in the magnetic circuit can be further improved, and the thrust for driving the lens holding member 12 can be further improved.

  Further, since the inner yoke 14C is disposed opposite to the plurality of magnets 15 with the coil 13 interposed therebetween, the flow of magnetic field flowing through the outer wall portion 14A of the yoke 14, the magnet 15, the coil 13, the inner yoke 14C, and the ceiling portion 14B ( Magnetic path) is formed. As a result, the direction of the magnetic field intersecting with the coil 13 is determined, a stable thrust can be obtained, and the lens holding member 12 can be driven stably.

Further, the protrusion 18f ₁ of the base member 18 and the protrusion 12f ₁ of the lens holding member 12 face _{each other} with a gap, and the two protruding portions 18h (18h ₁ , 18h ₂ ) of the base member 18 and the lens The bottom portion 12p of the holding member 12 is opposed to each other with a gap. Accordingly, the lens driving device 101 is subjected to an impact in drop or the like, even if not fully supported at three points of the projection 18f ₂ and two protrusions 18g of the base member 18 _(18g 1, 18g _2), the base member The lens holding member 12 is supported in a well-balanced manner at three points of the 18 protrusions 18f ₁ and the two protruding portions 18h (18h ₁ , 18h ₂ ), and the impact can be received in a well-balanced manner.

  Since two inclined portions 18s are formed on the opposite end side of the base member 18, the end portion 14t of the outer wall portion 14A formed on the open side of the yoke 14 preferentially contacts the inclined portion 18s. It becomes like this. As a result, it is possible to prevent the inner side surface 14p of the yoke 14 from hitting an undesired place on the outer peripheral side surface 18p of the base portion 18d and to improve the positioning accuracy.

  In addition, this invention is not limited to the said embodiment, For example, it can deform | transform and implement as follows, These embodiments also belong to the technical scope of this invention.

<Modification 1>
In the first embodiment, iron powder is suitably used as the magnetic material, but not only iron powder but also magnetic powder having magnetism may be used.

<Modification 2>
In the first embodiment, the upper leaf spring 16 </ b> A is fixed to the yoke 14 using the top cover 19. However, the upper leaf spring 16 </ b> A is not limited to this configuration, for example, between the yoke 14 and the magnet 15. The upper leaf spring 16A may be fixed to the yoke 14 with an adhesive A7.

<Modification 3>
In the said 1st Embodiment, although comprised using the rectangular-shaped yoke 14, you may comprise not only a rectangular shape but polygons, such as an octagon, for example.

<Modification 4>
In the first embodiment, the upper plate spring 16A and the lower plate springs (16C, 16E) are used as the elastic member 16, but any member that supports the lens holding member 12 so as to be movable in the optical axis direction. However, the present invention is not limited to this, and other members may be used.

  The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the scope of the object of the present invention.

DESCRIPTION OF SYMBOLS 12 Lens holding member 13 Coil 14 Yoke 14A Outer wall part 14B Ceiling part 14C Inner yoke 14k Opening part 15, 15A, 15B, 15C, 15D Magnet 16 Elastic member A7 Adhesive material SM Gap 101 Lens drive device

Claims (3)

A yoke having a cylindrical outer wall having a plurality of corners;
A plurality of magnets respectively disposed inside the plurality of corners of the yoke;
A cylindrical lens holding member disposed inside the yoke and capable of holding a lens body;
A coil wound in a ring around the lens holding member;
An elastic member that supports the lens holding member so as to be movable in the optical axis direction.
Having a gap between the outer wall and the magnet in the corner,
A lens driving device characterized in that an adhesive material mixed with a magnetic material is filled in the gap, and the magnet is adhered and fixed to the inner side surface of the outer wall portion by the adhesive material.   The lens driving apparatus according to claim 1, wherein the magnetic body is iron powder. The yoke has a ceiling part that is provided continuously with the upper end of the outer wall part and has an opening, and a plurality of inner yokes that extend downward from a part of the ceiling part,
The lens driving device according to claim 1, wherein the inner yoke is disposed to face the plurality of magnets with the coil interposed therebetween.

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