JP6679143B2 - Lens drive - Google Patents

Description

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

  In recent years, it has become common for mobile devices typified by mobile phones to include a camera mechanism. The lens driving device, which is the main component of the camera mechanism installed in this small portable device, is used for autofocusing to take a still image or a moving image. The demand for driving the lens body (lens barrel in which the lens is mounted) has been increasing. As a lens driving device that should satisfy these two requirements, a device in which a magnetic circuit for driving a lens holder (lens holding member) holding a lens body is provided around the lens holder is well known.

  Further, in recent years, it has been desired to focus quickly when shooting with autofocus, and in a lens driving device, speedup of autofocus, that is, faster driving in the optical axis direction has been demanded. . In order to meet this demand, attempts have been made to shorten the positioning time of the lens holder (lens holding member) by grasping and controlling the detailed position of the lens holder (lens holding member) in the optical axis direction.

  As the lens driving device described above, Patent Document 1 (conventional example) proposes an electromagnetic driving module 901 as shown in FIGS. 12 and 13. FIG. 12 is an exploded perspective view illustrating an electromagnetic drive module 901 of a conventional example. FIG. 13 is a top view of some of the components in the electromagnetic drive module 901 of the conventional example.

  The electromagnetic drive module 901 shown in FIG. 12 is installed in the upper housing 910 and the lower housing 930 which are engaged with each other to form a housing space, the frame 914 fixed to the upper housing 910 or the lower housing 930, and the frame 914. The two first magnetic elements 916 (permanent magnets), a base 918 that supports a lens assembly (not shown), a coil assembly 922 that has an annular structure and is installed outside the base 918, and a base 918. An upper spring seat 912 and a lower spring seat 928 that movably support along a vertical direction (the optical axis direction in the Z direction shown in FIG. 12), a reference element 920 (permanent magnet) arranged in a base 918 (see FIG. 13), a sensor element 926 (Hall effect sensor) that detects a change in the magnetic field of the reference element 920. ) And the sensor element 926 is configured to include a circuit board 924 mounted, the.

  Then, when the electromagnetic drive module 901 is assembled, as shown in FIG. 13, the coil assembly 922 is disposed on the outer periphery of the base 918, and the first magnetic elements 916 are respectively arranged so as to face each other in one direction. Is disposed outside the. Further, the reference element 920 is arranged in the base 918 in the other direction orthogonal to the one direction, and the sensor element 926 is arranged at a position facing the reference element 920 with the coil assembly 922 sandwiched therebetween.

  In the electromagnetic drive module 901 configured as described above, a magnetic circuit is formed by the two first magnetic elements 916 (permanent magnets) and the coil assembly 922, and electromagnetic force generated by energizing the coil assembly 922 causes the base 918. The (lens assembly supported by the base 918) is moved along the optical axis direction. At that time, the electromagnetic drive module 901 can determine the position of the reference element 920 by detecting the change in the magnetic field of the reference element 920 with the sensor element 926, and thus the base 918 (where the reference element 920 is disposed). The position of the lens holding member) can be detected. As a result, the electromagnetic drive module 901 can quickly move the lens assembly to a target position.

JP, 2005-107054, A

  However, in the conventional example, since there is no means such as a yoke for efficiently causing the magnetic flux from the first magnetic element 916 to act on the coil assembly 922, the thrust for moving the base 918 in the optical axis direction cannot be increased. There were challenges. On the other hand, in order to increase the propulsive force without increasing the number or size of the first magnetic elements 916, it is conceivable that the upper housing 910 is made of a magnetic metal and has a function of a yoke. However, in such a configuration, the magnetic field generated from the reference element 920 is affected by the magnetic fields generated from the two first magnetic elements 916 and the upper housing 910, and the sensor element 926 accurately detects the position of the base 918. There was a possibility that it could not be performed.

  The present invention solves the above-described problems, and provides a lens driving device that can secure thrust in the optical axis direction even if the lens holding member is configured to magnetically detect the position in the optical axis direction. To aim.

In order to solve this problem, a lens driving device of the present invention includes a cylindrical lens holding member capable of holding a lens body, a support member for movably supporting the lens holding member in an optical axis direction, and the lens. In a lens driving device including a drive mechanism that moves a holding member along the optical axis direction, and a position detection unit that detects a position of the lens holding member in the optical axis direction, the position detection unit is the A detection magnet fixed to the lens holding member and a magnetic detection member for detecting a magnetic field generated by the detection magnet, and the drive mechanism is wound around the lens holding member. And a plurality of driving magnets arranged outside the coil, and a yoke integrally provided with the plurality of driving magnets, the yoke being composed of: Magnetic metal Consists, have a peripheral wall portion positioned outside of the coil and the driving magnet, the outer peripheral wall portion, in plan view, is formed in a substantially rectangular shape having four corners, the detecting together are notched Oite a position corresponding to the use magnets are formed continuously with the exception of the portion corresponding to the previous SL-detecting magnet, the yoke, across the drive magnet and the coil and the An inner wall portion facing the corner portion and an upper plate portion connected to the inner wall portion and connected to the corner portion of the outer peripheral wall portion are provided, and the upper plate portion and the corner portion are connected to each other. The width dimension of the portion is formed to be smaller than the width dimension of the inner wall portion .

  According to this, in the lens driving device of the present invention, since the yoke is provided integrally with the driving magnet, the magnetic flux from the driving magnet can efficiently act on the coil, and the thrust force in the optical axis direction can be obtained. Can be improved. Further, since the outer peripheral wall portion of the yoke is cut out at the position corresponding to the detection magnet, the magnetic field generated from the detection magnet is less likely to be affected by the magnetic field generated from the yoke. Therefore, it is possible to ensure the detection accuracy of the position detection means (the detection magnet and the magnetic detection member). Therefore, it is possible to provide the lens driving device which can secure the thrust force in the optical axis direction even if it is provided with the structure for magnetically detecting the position of the lens holding member in the optical axis direction.

  According to this, the outer peripheral wall portion of the yoke is not formed in an annular shape, that is, the portion corresponding to the detection magnet has a separated shape (substantially C-shaped). Therefore, when the yoke is manufactured, it is possible to form the yoke by bending and processing the metal plate without squeezing the metal plate. As a result, the yoke can be easily processed, and the yoke can be manufactured at low cost.

  According to this, the inner wall portion serves as an inner yoke, and the magnetic flux from the driving magnet can be efficiently applied to the coil, and the thrust in the optical axis direction can be further increased. Further, since the width dimension of the portion (joint portion) connecting the upper plate portion and the corner portion is formed smaller than the inner wall portion, even if the inner wall portion is provided, one metal plate is bent and the yoke is bent. Can be produced. Moreover, the width of the inner wall can be increased, and the space between the inner wall and the corner can be increased. For these reasons, the yoke can be easily manufactured and the thrust can be further increased.

  In addition, the lens driving device of the present invention is a housing configured by a case member that accommodates the yoke so as to cover the yoke and a base member that is disposed below the lens holding member and is integrated with the case member. It is characterized by having.

  According to this, the cutout portion of the yoke is not exposed to the outside, and it is possible to prevent foreign matter from entering the lens holding member side. Further, since the whole body is covered with the housing, the lens driving device can be easily handled.

  Further, in the lens driving device of the present invention, the detection magnet is fixed to a lower portion of the lens holding member, and a wiring board on which the magnetic detection member is mounted is provided below the detection magnet. It is characterized by that.

  According to this, compared to the case where the detection magnet, the magnetic detection member, and the wiring member are provided on the side of the lens holding member, the dimension (projected area) of the shape in plan view can be reduced.

  Further, in the lens driving device of the present invention, the magnetic detection member has a magnetoresistive effect element whose electric resistance changes with a change in magnetic field, and the detection magnet is magnetized to different magnetic poles in the optical axis direction. When viewed from the optical axis direction, the center of the detection magnet and the center position of the magnetoresistive effect element are deviated from each other.

  According to this, the magnetoresistive effect element is arranged at a position where the degree of change of the magnetic field in the orthogonal direction orthogonal to the optical axis direction received by the magnetoresistive effect element is large. As a result, the change in the magnetic field due to the movement of the detection magnet increases, and the detection accuracy can be improved.

  In the lens driving device of the present invention, since the yoke is provided integrally with the driving magnet, the magnetic flux from the driving magnet can efficiently act on the coil, and the thrust in the optical axis direction can be improved. it can. Further, since the outer peripheral wall portion of the yoke is cut out at the position corresponding to the detection magnet, the magnetic field generated from the detection magnet is less likely to be affected by the magnetic field generated from the yoke. Therefore, it is possible to ensure the detection accuracy of the position detection means (the detection magnet and the magnetic detection member). Therefore, it is possible to provide the lens driving device which can secure the thrust force in the optical axis direction even if it is provided with the structure for magnetically detecting the position of the lens holding member in the optical axis direction.

It is an exploded perspective view explaining the lens drive device of a 1st embodiment of the present invention. It is a perspective view explaining the lens drive device of a 1st embodiment of the present invention. 3A and 3B are views for explaining the lens driving device of the first embodiment of the present invention, FIG. 3A is a top view of FIG. 2 seen from the Z1 side, and FIG. 3B is Y2 of FIG. It is the front view seen from the side. 4A and 4B are views for explaining the lens driving device according to the first embodiment of the present invention, FIG. 4A is a perspective view in which the case member shown in FIG. 2 is omitted, and FIG. It is the front view which looked at a) from the Y2 side. 5A and 5B are views for explaining the lens driving device of the first embodiment of the present invention, FIG. 5A is a bottom view of FIG. 2 seen from the Z2 side, and FIG. 5B is FIG. FIG. 4B is a bottom view in which the base member shown in FIG. 6A and 6B are diagrams illustrating a lens holding member of the lens driving device according to the first embodiment of the present invention, FIG. 6A is a perspective view of the lens holding member, and FIG. It is a perspective view which the coil was wound around the lens holding member shown to a). FIG. 7A is a diagram illustrating a support member of the lens driving device according to the first embodiment of the present invention, and FIG. 7A is a top view of the upper leaf spring shown in FIG. 1 as seen from the Z1 side. (B) is a top view of the lower leaf spring shown in FIG. 1 viewed from the Z1 side. FIG. 8A is a diagram illustrating a driving mechanism of the lens driving device according to the first embodiment of the present invention, and FIG. 8A is a perspective view in which the frame-shaped member and the upper leaf spring shown in FIG. 4A are omitted. FIG. 8B is a bottom view in which the lower leaf spring and the lens holding member shown in FIG. 5B are omitted. FIG. 9A is a diagram illustrating a driving mechanism of the lens driving device according to the first embodiment of the present invention, FIG. 9A is a top view of the yoke shown in FIG. 1 as seen from the Z1 side, and FIG. 3] is a lower perspective view of the yoke shown in FIG. 1 as viewed from the Z2 side. 10A is a diagram illustrating a base member of the lens driving device according to the first embodiment of the present invention, and FIG. 10A is an upper perspective view of the base member shown in FIG. 1 as seen from the Z1 side. FIG. 10B is a perspective view showing a state in which the lower leaf spring and the position detecting means are incorporated in the base member of FIG. 11A and 11B are views for explaining the position detecting means of the lens driving device according to the first embodiment of the present invention, FIG. 11A is a perspective view of the position detecting means, and FIG. It is a top view of the position detection means seen from the Z1 side shown in a). It is a disassembled perspective view explaining the electromagnetic drive module of a prior art example. It is a top view of some components in the electromagnetic drive module of a prior art example.

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

[First Embodiment]
FIG. 1 is an exploded perspective view illustrating a lens driving device 101 according to the first embodiment of the present invention. FIG. 2 is a perspective view illustrating the lens driving device 101 according to the first embodiment of the present invention. 3A is a top view of the lens driving device 101 viewed from the Z1 side in FIG. 2, and FIG. 3B is a front view of the lens driving device 101 viewed from the Y2 side in FIG. 4A is a perspective view in which the case member 16 of the lens driving device 101 shown in FIG. 2 is omitted, and FIG. 4B is a front view of FIG. 4A viewed from the Y2 side. 5A is a bottom view of FIG. 2 seen from the Z2 side, and FIG. 5B is a bottom view of the base member 36 shown in FIG. 5A omitted.

  The lens driving device 101 according to the first embodiment of the present invention has a rectangular parallelepiped appearance as shown in FIGS. 2, 3 and 5 (a), and as shown in FIG. ), A cylindrical lens holding member 2, a support member 3 for movably supporting the lens holding member 2 in the optical axis direction KD, and the lens holding member 2 in the optical axis direction KD (Z direction shown in FIG. 2). ), A housing 6 for housing the lens holding member 2 and the driving mechanism M5, and position detecting means K7 for detecting the position of the lens holding member 2 in the optical axis direction KD. Is configured. In addition, in the first embodiment of the present invention, the lens driving device 101 has a frame-shaped member 44 disposed above the lens holding member 2 (Z1 direction shown in FIG. 4A).

  In addition, in the first embodiment of the present invention, the support member 3 includes the upper leaf spring 3A fixed to the upper portion of the lens holding member 2 as shown in FIG. 4A and the support member 3 as shown in FIG. 5B. And a lower plate spring 3E fixed to the lower part of the lens holding member 2 to support the lens holding member 2.

  In addition, as shown in FIG. 4, the drive mechanism M5 includes an annular coil 35 wound around the lens holding member 2, and four drive magnets 55 that are arranged to face each other outside the coil 35. And a yoke 75 provided integrally with the four driving magnets 55, and the lens holding member 2 is movable along the optical axis direction KD.

  As shown in FIG. 2, the housing 6 is composed of a case member 16 having a rectangular parallelepiped shape and a box-shaped outer shape, and a base member 36 integrated with the case member 16. There is.

  In addition, the position detecting means K7 includes a detection magnet 57 (see FIG. 4B) fixed to the lens holding member 2 and a magnetic detection member 77 (see FIG. 11) that detects a magnetic field generated by the detection magnet 57. And a wiring board 97 (see FIG. 11) on which the magnetic detection member 77 is mounted.

  Then, the lens driving device 101 holds a lens body (not shown) on the lens holding member 2 and is mounted on a mounting substrate (not shown) on which the image pickup element is mounted. Then, in order to drive the lens held by the lens body in the optical axis direction KD (Z direction shown in FIG. 2) to adjust the focal length, the lens driving device 101 is configured such that a current is supplied from the power supply to the coil 35. The generated electromagnetic force causes the lens holding member 2 to move along the optical axis direction KD with respect to the image pickup element.

  Next, each component will be described in detail. First, the lens holding member 2 of the lens driving device 101 will be described. 6A and 6B are views for explaining the lens holding member 2, FIG. 6A is a perspective view of the lens holding member 2, and FIG. 6B is a lens holding member shown in FIG. 6A. 2 is a perspective view in which a coil 35 is wound around 2. Note that FIG. 6B also shows the detection magnet 57 of the position detection means K7 fixed to the lens holding member 2.

  The lens holding member 2 of the lens driving device 101 is made of liquid crystal polymer (LCP, Liquid Crystal Polymer), which is one of synthetic resins, and is formed in a cylindrical shape as shown in FIG. The tubular portion 12 having a peripheral surface, the projecting portions 22 provided at the outer peripheral surface of the tubular portion 12 at four locations in the X direction and the Y direction, and the lower end side of the tubular portion 12 (Z2 side shown in FIG. 6). ) Mainly includes a collar portion 32 that protrudes radially outward from the outer peripheral surface. As shown in FIG. 4, the lens holding member 2 is arranged below the frame-shaped member 44 (Z2 direction shown in FIG. 4) and above the base member 36 (Z1 direction shown in FIG. 4).

  A lens body (not shown) can be attached to the inner peripheral surface of the cylindrical portion 12 of the lens holding member 2, and the lens body is held by the lens holding member 2 using an adhesive or the like. Further, in the vicinity of the projecting portion 22 on the upper end side of the tubular portion 12, four recessed notch portions 12d are formed diagonally opposite to each other. Then, when the lens driving device 101 is assembled, as shown in FIG. 4A, the four cutouts 12d (lens holding member 2) and the upper leaf spring 3A of the support member 3 (described later). The first part 13) is fixed with an adhesive.

  As shown in FIG. 6A, the projecting portion 22 of the lens holding member 2 includes an eave portion 22h protruding radially outward from the outer peripheral surface on the upper end side (Z1 side shown in FIG. 4), and an eave portion 22h. 6B, the coil 35 is supported by this portion and the coil 35 is wound into an octagonal shape (see FIG. 1). ing. In a portion where the protruding portion 22 is not provided, a gap is provided between the outer peripheral surface of the tubular portion 12 and the coil 35, into which an inner wall portion 75C of the yoke 75, which will be described later, is inserted.

  As shown in FIG. 6A, the lens holding member 2 has one accommodating portion 2s surrounded by two sides on the lower side of the flange 32, and as shown in FIG. 6B. The detecting magnet 57 of the position detecting means K7 is attached to the housing 2s. Then, the detection magnet 57 is fixed to the lower portion of the lens holding member 2 using an adhesive or the like.

Further, as shown in FIG. 5B, a cylindrical protrusion 12t protruding downward (in the front in FIG. 5B, the Z2 direction shown in FIG. 6) is provided on the bottom surface on the side of the flange 32. It is provided at six locations (three protruding portions 12t ₁ and three protruding portions 12t ₂ ). In addition, in FIG. 5B, the one protruding portion 12t ₁ and the one protruding portion 12t ₂ are not shown because they are hidden by the position detecting means K7. Then, when the lens driving device 101 is assembled, as shown in FIG. 5B, the three protruding portions 12t _{1 are} caulked and engaged with the lower leaf spring 3C (the third portion 33 described later). At the same time, the three protruding portions 12t _{2 are} crimped and engaged with the lower leaf spring 3E (the third portion 33 described later).

  Further, on the bottom surface of the lens holding member 2, as shown in FIG. 5B, prismatic entwined portions 12k protruding downward are provided at two positions. Each of the coil ends (not shown) of the coil 35 is wound around the entwined portion 12k and soldered to the two lower leaf springs 3C and 3E. Note that, in FIG. 5B, the solder HD in which the two coil ends are soldered to the lower leaf spring 3C and the lower leaf spring 3E is schematically shown by cross hatching surrounded by broken lines.

  Next, the support member 3 of the lens driving device 101 will be described. 7A and 7B are views for explaining the support member 3, FIG. 7A is a top view of the upper leaf spring 3A shown in FIG. 1 seen from the Z1 side, and FIG. 7B is FIG. 3C is a top view of the lower leaf spring 3C and the lower leaf spring 3E shown in FIG.

  The support member 3 of the lens driving device 101 is made of a metal plate whose main material is copper alloy, and as shown in FIG. An upper leaf spring 3A having a large diameter opening and arranged between the lens holding member 2 and the frame-shaped member 44, and two lower leaf springs arranged between the lens holding member 2 and the base member 36. It is composed of a side leaf spring 3C and a lower leaf spring 3E. Then, each of the lens holding member 2 and the support member 3 (the upper leaf spring 3A, the lower leaf spring 3C, the lower leaf spring 3E) is engaged, and the lens holding member 2 is moved in the optical axis direction KD (Z direction shown in FIG. 2). ), The lens holding member 2 is supported. Since the lower leaf spring 3C and the lower leaf spring 3E (two leaf springs) are electrically connected to the coil 35 by solder HD as shown in FIG. 5B, a power feeding member for the coil 35 is provided. Also has a function as.

  First, as shown in FIG. 7A, the upper leaf spring 3A of the support member 3 has a substantially rectangular outer shape, and is fixed to the lens holding member 2 in plural (first embodiment of the present invention. (Four places), first portions 13 and four second portions 23 located on the outer peripheral side of the first portion 13 and fixed to the housing 6 side (specifically, the frame-shaped member 44). Four elastic arm portions 53a provided between the first portion 13 and the second portion 23, a connecting portion 63 extending from the first portion 13 and connected, and four second portions 23 are connected to each other. And a connecting bar portion 73 to be connected. In addition, the inner shape of the first portion 13 and the connecting portion 63 forms an annular shape, and the outer shape of the second portion 23 and the crosspiece portion 73 forms a rectangular shape.

  Then, when the upper leaf spring 3A is incorporated in the lens driving device 101, as shown in FIG. 4A, the four positions of the first portion 13 are respectively changed to the four positions of the cutout portion 12d of the lens holding member 2. The first portion 13 and the cutout portion 12d, which are arranged to face each other, are fixed to each other with an adhesive, so that one side of the upper leaf spring 3A is fixed to the lens holding member 2.

  On the other hand, the four portions of the second portion 23 are arranged so as to contact the upper surface of the driving magnet 55, respectively, and are sandwiched and fixed by the driving magnet 55 and the case member 16 via the frame-shaped member 44 and the yoke 75. Therefore, the other side of the upper leaf spring 3A is fixed to the housing 6 side.

  In this way, the upper leaf spring 3A is formed in a substantially point-symmetrical shape as shown in FIG. 7A, and the first portion 13 has four uniform positions with respect to the lens holding member 2. And is fixed to the frame-shaped member 44, and further to the housing 6 (case member 16) at four equal positions of the second portion 23. As a result, the lens holding member 2 can be supported in good balance.

  Next, the lower leaf spring 3C and the lower leaf spring 3E of the support member 3 have a substantially rectangular outer shape and a semicircular inner shape as shown in FIG. Each of them is formed to be substantially point-symmetrical. Further, the lower leaf spring 3C and the lower leaf spring 3E include six third portions 33 engaged with the lens holding member 2 and four fourth portions 43 engaged with the base member 36 (described later). 10B), four elastic arm portions 53c and 53e located between the third portion 33 and the fourth portion 43, and the first connecting the third portion 33 at each of the three portions. It is configured to have a chain portion 83 and a second chain portion 93 that connects the fourth portions 43 at two locations, respectively.

  Further, as shown in FIG. 7B, circular through holes 33k are formed in the third portions 33 of the lower leaf spring 3C and the lower leaf spring 3E, respectively. In addition, circular through holes 43m are formed in the fourth portions 43 of the lower leaf springs 3C and 3E, respectively, and rectangular through holes 43s and 43t are formed in one location, respectively. .

Then, when the lower leaf spring 3C and the lower leaf spring 3E are incorporated into the lens driving device 101, as shown in FIG. 5B, the three protruding portions 12t ₁ (12t) of the lens holding member 2 are provided. Is inserted and fitted into the through hole 33k (see FIG. 7B) of the third portion 33 of the lower leaf spring 3C, and the three protruding portions 12t ₂ (12t) of the lens holding member 2 are , The lower leaf spring 3E is inserted into and fitted into the through hole 33k (see FIG. 7B) of the third portion 33 of the lower leaf spring 3E. As a result, one side of the lower leaf spring 3C and the lower leaf spring 3E is positioned on the lens holding member 2 and fixed to the lens holding member 2. At this time, the convex portions 12t (12t ₁ , 12t ₂ ) of the lens holding member 2 are heat-squeezed to more securely fix the lower leaf spring 3C and the lower leaf spring 3E to the lens holding member 2. ing.

  On the other hand, a protrusion 36t (see FIG. 10A) provided on the upper surface of the base member 36 described later has a through hole 43m (see FIG. 7 (see FIG. 7 (C)) of the lower leaf spring 3C and the lower leaf spring 3E. (See FIG. 10B) and is fitted (see FIG. 10B described later). As a result, the other side of the lower leaf spring 3C and the lower leaf spring 3E is positioned on the base member 36 and fixed to the base member 36.

  In this way, the lower leaf spring 3C and the lower leaf spring 3E are formed in a substantially point-symmetrical shape, as shown in FIG. 7B, and the third portion 33 of the lens holding member 2 is provided. The connection is made at six uniform positions, and is also made at four uniform positions on the fourth portion 43 with respect to the base member 36. As a result, the lens holding member 2 can be supported in good balance. Therefore, the support member 3 configured as described above supports the lens holding member 2 so as to be movable in the optical axis direction KD.

  Next, the driving mechanism M5 of the lens driving device 101 will be described. FIG. 8 is a diagram for explaining the drive mechanism M5, and FIG. 8A is a perspective view in which the frame-shaped member 44 and the upper leaf spring 3A shown in FIG. 4A are omitted, and FIG. 5B is a bottom view in which the lower leaf spring 3C, the lower leaf spring 3E, and the lens holding member 2 shown in FIG. 5B are omitted. Note that FIG. 8B shows the case member 16, the upper leaf spring 3A, the drive mechanism M5, and the position detection means K7. 9A and 9B are views for explaining the drive mechanism M5. FIG. 9A is a top view of the yoke 75 shown in FIG. 1 seen from the Z1 side, and FIG. 9B is shown in FIG. It is the lower perspective view which looked at the yoke 75 from the Z2 side.

  The drive mechanism M5 of the lens driving device 101 has a function of moving the lens holding member 2 along the optical axis direction KD (Z direction shown in FIG. 1), and as shown in FIG. 2, an annular coil 35 wound around 2, two driving magnets 55 arranged to face the outside of the coil 35, and a yoke 75 arranged so as to cover the four driving magnets 55. And are provided.

  First, the coil 35 of the drive mechanism M5 is made of a metal wire material having an outer periphery coated with an insulation coating (coating), and is wound around the outer periphery of the lens holding member 2 as shown in FIG. As shown in, it is formed in a substantially octagonal ring shape. At that time, as shown in FIG. 6B, the coil 35 is disposed between the eaves portion 22h and the collar portion 32, and is provided at four support portions 22j (see FIG. 6A). It is supported and fixed from the inside. Note that the coil 35 has a shape in which a metal wire is wound and bundled, but in FIGS. 1, 4, 6 (b) and 8, the surface is simplified and shown with a flat surface. There is.

  The coil 35 is configured such that both ends of the wound metal wire can be electrically conducted, and as described above, as shown in FIG. 5B, a coil end (not shown). Are soldered and electrically connected to the two lower leaf springs 3C and 3E.

  Next, as the driving magnet 55 of the driving mechanism M5, for example, four samarium-cobalt magnets are used, and as shown in FIG. 8B, they are arranged at the four corners of the case member 16 (housing 6) so as to surround the optical axis. Has been done. In addition, the driving magnets 55 are formed in a trapezoidal shape in cross section so as to be efficiently arranged at the four corners, and the upper bottom faces the corner portion 16C (described later) of the case member 16 via the yoke 75. At the same time, the legs are shaped along the side wall portion 16A (described later) of the case member 16 and the outer peripheral wall portion 75A (described later) of the yoke 75.

  The drive magnet 55 is arranged so that the trapezoidal lower bottom faces the coil 35, as shown in FIG. 8B. The driving magnet 55 is magnetized to have different magnetic poles on the inside (the trapezoidal lower bottom side) facing the coil 35 and on the outside (the trapezoidal upper bottom side) opposite to the inside. There is.

  Next, the yoke 75 of the drive mechanism M5 is made of a metal plate having magnetism, and as shown in FIG. 9A, the outer peripheral wall portion 75A and the outer peripheral wall portion 75A which are formed in a substantially rectangular shape in plan view. The inner wall portion 75C and the upper plate portion 75T connecting the corner portion 75k and the inner wall portion 75C are configured so as to face the four corner portions 75k apart from each other (see FIG. 9B). ing. The yoke 75 is made by bending a single metal plate.

  The outer peripheral wall portion 75A of the yoke 75 has a shape formed continuously except a part thereof. That is, the outer peripheral wall portion 75A has a shape in which a part thereof is cut out, that is, has a substantially C-shape in a plan view. As shown in FIG. 8A, the detecting magnet 57 of the position detecting means K7 is arranged in the cutout portion. As a result, the outer peripheral wall portion 75A is not formed in an annular shape, and when the yoke 75 is manufactured, the metal plate can be bent and processed without being squeezed to form the shape of the yoke 75. As a result, the yoke 75 can be easily processed and the yoke 75 can be manufactured at low cost.

  Further, as shown in FIG. 8B, the outer peripheral wall portion 75A is located outside the coil 35 and the driving magnet 55, and along the case member 16 (specifically, the side wall portion 16A described later). It has a curved shape. The trapezoidal leg of the drive magnet 55 is in contact with and fixed to the outer peripheral wall portion 75A with an adhesive or the like. As a result, the yoke 75 is integrated with the four driving magnets 55. As a result, the magnetic flux from the drive magnet 55 can be efficiently applied to the coil 35 by the yoke 75, and the thrust in the optical axis direction KD can be improved. In addition, in the first embodiment of the present invention, the corner portion 75k of the outer peripheral wall portion 75A is a flat plate-shaped corner wall, and as shown in FIG. It preferably faces the bottom in a substantially parallel state. The corner portion 75k does not necessarily have to be a flat plate shape, and may have, for example, a curved surface shape that bulges toward the case member 16 side.

  Further, the inner wall portion 75C of the yoke 75 is connected by the upper plate portion 75T and faces the corner portion 75k, and is provided at a position sandwiching the coil 35 and the driving magnet 55. As a result, the inner wall portion 75C serves as an inner yoke, and the magnetic flux from the driving magnet 55 can be efficiently applied to the coil 35, and the thrust in the optical axis direction KD can be further increased.

  Further, as shown in FIG. 9A, the yoke 75 is formed such that the width dimension of the portion (joint portion) connecting the upper plate portion 75T and the corner portion 75k is smaller than the width dimension of the inner wall portion 75C. There is. Therefore, even if the inner wall portion 75C is provided, the yoke 75 can be manufactured by bending one metal plate. Moreover, the width dimension of the inner wall portion 75C can be increased, and the space between the inner wall portion 75C and the corner portion 75k can be increased. For these reasons, the yoke 75 can be easily manufactured and the thrust can be further increased.

  As described above, since the lens holding member 2, the coil 35, the driving magnet 55, and the yoke 75 are respectively arranged, the lens driving device 101 operates from the power source to the lower leaf spring 3C and the lower leaf spring 3E. The electromagnetic force generated by the current flowing through the coil 35 through the coil causes a thrust force to act on the coil 35 in accordance with the direction of the current flow, so that the lens holding member 2 moves up and down. Moreover, in the first embodiment of the present invention, since the driving magnets 55 are arranged in the corner portions 16C located at the four corners of the case member 16 so as to surround the optical axis, the coil 35, the driving magnet 55, and the yoke 75 are disposed. The driving force in the optical axis direction KD, which is generated by, can be applied to the lens holding member 2 in a well-balanced manner.

  Next, the frame-shaped member 44 of the lens driving device 101 will be described. The frame-shaped member 44 is a frame body formed of a synthetic resin such as polybutylene terephthalate (PBT) and having a rectangular opening 44k at the center as shown in FIG. Then, when the frame-shaped member 44 is incorporated in the lens driving device 101, it is disposed above the upper leaf spring 3A as shown in FIG. The second portion 23 of the upper leaf spring 3A is sandwiched between the corner portion of and the driving magnet 55. As a result, the other side of the upper leaf spring 3A is fixed to the housing 6 side.

  Next, the housing 6 of the lens driving device 101 will be described. FIG. 10 is a diagram for explaining the base member 36 of the housing 6, and FIG. 10A is an upper perspective view of the base member 36 shown in FIG. 1 as seen from the Z1 side, and FIG. FIG. 11 is a perspective view showing a state in which the lower leaf spring 3C and the lower leaf spring 3E and the position detecting means K7 are incorporated in the base member 36 of FIG. 10 (a). In addition, in FIG. 10A, the magnetic detection member 77 of the position detection means K7 is shown for the sake of easy understanding. Further, FIG. 10B shows the detection magnet 57 fixed to the lens holding member 2 and the wiring board 97 of the position detection means K7.

  As shown in FIG. 1, the housing 6 is composed of a case member 16 having a box-shaped outer shape, and a base member 36 integrated with the case member 16. Since the case member 16 is housed so as to cover the yoke 75, the cutout portion of the yoke 75 is not exposed to the outside, and foreign matter is prevented from entering the lens holding member 2 side. be able to. Furthermore, since the case member 16 and the base member 36 are integrated, the lens driving device 101 can be easily handled.

  First, the case member 16 of the housing 6 will be described. The case member 16 is manufactured by performing a cutting process, a drawing process, and the like using a metal plate made of a non-magnetic metal material. The case member 16 has a box-shaped outer shape as shown in FIG. It has a substantially rectangular shape (in plan view) as shown in FIG. The case member 16 includes a flat plate-shaped side wall portion 16A, a flat plate-shaped ceiling portion 16B provided continuously with the upper end of the side wall portion 16A (on the Z1 side in FIG. 1), and adjacent side wall portions 16A. And a corner portion 16C located at the connecting portion, and a substantially circular opening 16k is formed in the ceiling portion 16B.

  The case member 16 includes the lens holding member 2, the support member 3 (the upper leaf spring 3A, the lower leaf spring 3C, the lower leaf spring 3E), the frame member 44, and the drive mechanism M5 (the coil 35, the drive magnet 55, and the yoke). 75) so as to cover these members and to be engaged with a base member 36 disposed on the lower side (Z2 direction shown in FIG. 2) of the lens holding member 2 to be integrated with the base member 36. Has been done. The case member 16 and the yoke 75 are integrated by an adhesive.

  Next, the base member 36 of the housing 6 will be described. The base member 36 is made by injection molding using the same synthetic resin material as the lens holding member 2 such as liquid crystal polymer (LCP), and as shown in FIG. 10A, the outer shape is a rectangular plate shape. And is formed in an annular shape having a circular opening 36k in the center thereof.

Further, on the upper surface of the base member 36, as shown in FIG. 10A, six projecting portions 36t (three projecting portions 36t ₁ and three projecting portions 36t ₂ ) projecting upward are provided. It is provided in the four corners. Then, as described above, as shown in FIG. 10B, the protruding portion 36t is inserted into and fitted into the through holes 43m (see FIG. 7B) of the lower leaf spring 3C and the lower leaf spring 3E. Are combined. At this time, the protruding portion 36t of the base member 36 is subjected to heat staking to more securely fix the lower leaf spring 3C and the lower leaf spring 3E to the base member 36.

  Further, as shown in FIG. 10A, the base member 36 is provided with a through hole 36h on the side where the position detecting means K7 is arranged (Y2 side shown in FIG. 10). The magnetism detecting member 77 of the position detecting means K7 is arranged to face the through hole 36h. Further, the detection magnet 57 of the position detection means K7 is also arranged to face the through hole 36h. That is, the magnetic detection member 77 and the detection magnet 57 face each other through the through hole 36h.

  Further, as shown in FIG. 10B, the base member 36 has three terminals T9 (a power supply terminal T9C, a power supply terminal T9C) made of a metal plate made of a material such as copper or iron or an alloy containing them as a main component. T9E and ground terminal T9G) are insert-molded and embedded. Each of the three electrically insulated terminals T9 is electrically connected to an electrode land of a mounting board on which an image pickup device (not shown) is mounted, so that power can be supplied from the electrode land of the mounting board and the electrode It is designed to be grounded on the land. That is, the power feeding terminal T9C and the power feeding terminal T9E are connected to the power source, and the ground terminal T9G is connected to the ground.

  Further, the power feeding terminal T9C is electrically connected to the connecting portion T9d shown in FIG. 10A at the through hole 43s portion of the lower leaf spring 3C shown in FIG. 10B, and the power feeding terminal T9E is The through hole 43t of the lower leaf spring 3E shown in FIG. 10 (b) is electrically connected to the connecting portion T9f shown in FIG. 10 (a). As a result, current can be passed (energized) from the power supply terminal T9C and the power supply terminal T9E to the coil 35 via the lower leaf spring 3C and the lower leaf spring 3E. Although not shown, the lower leaf spring 3C and the lower leaf spring 3E are connected to the feeding terminal T9C and the feeding terminal T9E by soldering or the like.

  Although not shown in detail in the base member 36, the connection member 59 made of a metal plate made of a material such as copper, iron, or an alloy containing them as a main component is also similar to the three terminals T9. The connection member 59 is partly exposed at the four corners of the case member 16, as shown in FIG. 3A. Then, after the inner wall of the side wall portion 16A of the case member 16 and the outer peripheral side surface of the base member 36 are combined and positioned, the joint portions of the connecting member 59 of the base member 36 and the four corners of the case member 16 are welded at four locations. The case member 16 is fixed to the base member 36.

  Finally, the position detecting means K7 of the lens driving device 101 will be described. 11A is a perspective view of the position detecting means K7, and FIG. 11B is a top view of the position detecting means K7 viewed from the Z1 side shown in FIG. 11A. Note that, in FIG. 11B, the magnetoresistive effect element RE built in the magnetic detection member 77 is schematically shown by a cross hatch. Further, in FIG. 11, the detection magnet 57 fixed to the lens holding member 2 is also shown.

  As shown in FIG. 11, the position detecting means K7 includes a detection magnet 57 fixed to the lens holding member 2 (see FIG. 8A) and a magnetic detection member for detecting a magnetic field generated by the detection magnet 57. 77 and a wiring board 97 on which the magnetic detection member 77 is mounted.

  First, the detection magnet 57 of the position detection means K7 is formed in a substantially rectangular parallelepiped shape by using, for example, one samarium-cobalt magnet, and as shown in FIG. 6B, the lower side of the collar portion 32 of the lens holding member 2. And is fixed to the lower part. As a result, the detection magnet 57 moves along with the movement of the lens holding member 2. Further, the detection magnet 57 is magnetized to different magnetic poles in the optical axis direction KD, and can be composed of one magnet, so that the detection magnet 57 can be made easier than in the case of being composed of two magnets. It can be arranged and can be manufactured at low cost.

  In addition, as shown in FIG. 4, the detection magnet 57 is located at a position where the outer peripheral wall portion 75A of the yoke 75 is cut out, and is also at a uniform position (position apart) from the notched end portion of the outer peripheral wall portion 75A. (See FIG. 4B). As a result, the magnetic field generated by the detection magnet 57 is less likely to be affected by the magnetic field generated by the yoke 75. Therefore, the detection accuracy of the position detection means K7 (the detection magnet 57 and the magnetic detection member 77) can be ensured.

  Next, the magnetic detecting member 77 of the position detecting means K7 uses a magnetoresistive effect element RE (see FIG. 11B) whose electric resistance changes due to a change in magnetic field, for example, a magnetic detecting element using a giant magnetoresistive effect ( GMR (Giant Magneto Resistive) element) is used. Further, the magnetic detection member 77 exposes four terminal portions (in FIG. 11A, only two terminal portions on one side are shown and is shown as 77a and 77b) to the outside, and thermosetting is performed. It is formed of a package in which the magnetoresistive effect element RE is built in using a synthetic resin having a magnetic property.

  The magnetic detection member 77 is fixed to the wiring board 97 by being soldered to four conductive members 97d of the wiring board 97, which will be described later, so as to face the detection magnet 57 at a distance. Further, the magnetic detection member 77 is arranged on the lower side (Z2 side) of the detection magnet 57, as shown in FIG. Then, the magnetic detection member 77 can detect the magnetic field generated by the detection magnet 57 fixed to the lens holding member 2 and detect the change in the direction of the magnetic field due to the movement in the optical axis direction KD. Therefore, the lens driving device 101 according to the first embodiment of the present invention can detect the position of the lens holding member 2 in the optical axis direction KD and correct the actual position of the lens holding member 2. As a result, the corrected lens holding member 2 whose position is clear can be quickly moved to a predetermined position such as a position where the image is in focus. Therefore, the time until the position of the lens holding member 2 is settled can be shortened, and the lens holding member 2 can be quickly and surely moved to a predetermined position.

  Further, in the first embodiment of the present invention, as shown in FIG. 11B, when viewed from the optical axis direction KD, the center position of the detection magnet 57 and the center position of the magnetoresistive effect element RE are light. It is displaced in the radial direction RD about the axis. As a result, the magnetoresistive effect element RE is arranged at a position where the degree of change of the magnetic field (direction) in the orthogonal direction (radial direction RD) orthogonal to the optical axis direction KD received by the magnetoresistive effect element RE is large. Become. As a result, the change in the direction of the magnetic field due to the movement of the detection magnet 57 (the movement of the lens holding member 2) increases, and the detection accuracy can be improved.

  Next, the wiring board 97 of the position detecting means K7 is formed in a plate shape, and as shown in FIG. 11 (a), four external terminals 97c formed of a conductive metal member and the external terminals 97c. It is configured to include a conductive member 97d that is integrally formed with 97c and forms a conductive pattern, and a base material portion 97f that exposes the external terminal 97c and burys the conductive member 97d. The magnetic detection member 77 is mounted on the wiring board 97, and the four external terminals 97c of the wiring board 97 are electrically connected to the four terminal portions of the magnetic detection member 77 through the conductive members 97d. It

  The wiring board 97 is arranged below the detection magnet 57 when the lens driving device 101 is assembled, as shown in FIG. Since the lower surface side of the base member 36 is formed with an accommodating portion (recess) for accommodating the wiring board 97, the wiring board 97 is arranged in this accommodating portion, so that the wiring The substrate 97 is arranged inside the outer shape of the base member 36 on the lower surface side of the base member 36. The wiring board 97 is fixed to the base member 36 with an adhesive or the like. As a result, the dimension (projected area) of the shape in plan view can be made smaller than in the case where the detection magnet 57, the magnetic detection member 77, and the wiring member are provided on the side of the lens holding member 2.

  The external terminal 97c of the wiring board 97 is formed to extend in the same direction (Z2 direction shown in FIG. 4) as the above-described three terminals T9 (power feeding terminal T9C, power feeding terminal T9E, and ground terminal T9G). . Then, the four external terminals 97c are electrically connected to the terminal T9 of the base member 36 and the electrode lands of the mounting board on which the image pickup device (not shown) is mounted. As a result, the three terminals T9 and the four external terminals 97c are arranged in a line, which facilitates the layout of the mounting board or the like on which the lens driving device 101 is mounted.

  In the position detecting means K7 configured as described above, the magnetic flux generated from the detecting magnet 57 changes due to the movement of the detecting magnet 57 with the movement of the lens holding member 2. It is detected by the detection member 77. Thereby, the position detecting means K7 can detect the position corresponding to the change of the magnetic flux, that is, the position of the lens holding member 2 in the optical axis direction KD.

  Finally, the operation of the lens driving device 101 configured as described above will be briefly described.

  First, in the lens driving device 101, since both ends of the coil 35 are electrically connected to the power feeding terminal T9C and the power feeding terminal T9E via the lower leaf spring 3C and the lower leaf spring 3E, the power feeding terminal T9C and the power feeding terminal T9C are connected. A current can flow from the terminal T9E to the coil 35. On the other hand, the magnetic flux from the drive magnet 55 is emitted from the drive magnet 55, passes through the coil 35, and returns to the drive magnet 55 with the help of the yoke 75.

  From this initial state, when a current is passed from the side of the power supply terminal T9C to the coil 35, an electromagnetic force is generated in the coil 35 from the Z1 direction, which is the optical axis direction KD, to the Z2 direction according to Fleming's left-hand rule. Then, the lens holding member 2 moves in the Z2 direction. On the other hand, when a current is passed from the power supply terminal T9E side to the coil 35, an electromagnetic force is generated from the Z2 direction, which is the optical axis direction KD, toward the Z1 direction, and the lens holding member 2 moves in the Z1 direction. As described above, by supplying an electric current to the coil 35, the lens driving device 101 is supported by the supporting member 3 by an electromagnetic force generated in the coil 35, and a lens body (not shown) is integrated with the lens holding member 2, It becomes possible to move along the optical axis direction KD (Z direction shown in FIG. 2).

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

  In the lens driving device 101 of the first embodiment of the present invention, the driving mechanism M5 has the yoke 75 provided integrally with the plurality of driving magnets 55, so that the magnetic flux from the driving magnet 55 can be efficiently generated. This can act on the coil 35, and the thrust in the optical axis direction KD can be improved. In addition, since the outer peripheral wall portion 75A of the yoke 75 is cut out at a position corresponding to the detection magnet 57 for detecting the position of the lens holding member 2 in the optical axis direction KD, it is generated from the detection magnet 57. The generated magnetic field is less likely to be affected by the magnetic field generated from the yoke 75. Therefore, the detection accuracy of the position detection means K7 (the detection magnet 57 and the magnetic detection member 77) can be ensured. Therefore, it is possible to provide the lens driving device 101 that can secure the thrust force in the optical axis direction KD even if the lens holding member 2 is provided with a structure for magnetically detecting the position in the optical axis direction KD.

  Since the outer peripheral wall portion 75A of the yoke 75 is continuously formed except the portion corresponding to the detection magnet 57, the outer peripheral wall portion 75A of the yoke 75 is not formed in an annular shape, that is, the detection magnet 57. Has a separated shape (substantially C-shaped). Therefore, when the yoke 75 is manufactured, the shape of the yoke 75 can be formed by bending and processing the metal plate having magnetism without squeezing and processing. As a result, the yoke 75 can be easily processed and the yoke 75 can be manufactured at low cost.

  Further, since the yoke 75 has an inner wall portion 75C that faces the corner portion 75k of the outer peripheral wall portion 75A with the driving magnet 55 and the coil 35 interposed therebetween, the inner wall portion 75C serves as an inner yoke, and the driving magnet The magnetic flux from 55 can be efficiently applied to the coil 35, and the thrust in the optical axis direction KD can be further increased. Further, since the width dimension of the portion (joint portion) connecting the upper plate portion 75T and the corner portion 75k is formed smaller than the inner wall portion 75C, even if the inner wall portion 75C is provided, one metal plate Can be bent to form the yoke 75. Moreover, the width dimension of the inner wall portion 75C can be increased, and the space between the inner wall portion 75C and the corner portion 75k can be increased. For these reasons, the yoke 75 can be easily manufactured and the thrust can be further increased.

  Further, since the yoke 75 is covered by the case member 16, the cutout portion of the yoke 75 is not exposed to the outside, and foreign matter can be prevented from entering the lens holding member 2 side. Furthermore, since the entire body is covered with the housing 6, the lens driving device 101 can be easily handled.

  Further, since the detection magnet 57 is fixed to the lower portion of the lens holding member 2 and the wiring board 97 on which the magnetic detection member 77 is mounted is provided below the detection magnet 57, Compared with the case where the magnetic detection member 77 and the wiring member are provided on the side of the lens holding member 2, the dimension (projected area) of the shape in plan view can be reduced.

  Further, when viewed from the optical axis direction KD, the center position of the detection magnet 57 and the center position of the magnetoresistive effect element RE are misaligned, so that the magnetoresistive effect element RE is orthogonal to the optical axis direction KD received by the magnetoresistive effect element RE. The magnetoresistive effect element RE is arranged at a position where the degree of change of the magnetic field in the direction (radial direction RD) is large. As a result, the change in the magnetic field due to the movement of the detection magnet 57 (the movement of the lens holding member 2) becomes large, and the detection accuracy can be improved.

  Note that the present invention is not limited to the above-described embodiments, and can be modified and implemented as follows, for example, and these embodiments also belong to the technical scope of the present invention.

<Modification 1>
In the first embodiment, the yoke 75 is preferably formed by using one metal plate and integrally forming the outer peripheral wall portion 75A, the inner wall portion 75C, and the upper plate portion 75T, but the present invention is not limited to this. Instead, they may be formed separately and combined.

<Modification 2>
In the first embodiment described above, the GMR element is preferably used as the magnetic detection member 77, but in addition, an MR (Magneto Resistive) element or an AMR (Anisotropic Magneto Resistive) element of a type in which electric resistance changes due to a change in magnetic field is used. It may be an element, a TMR (Tunnel Magneto Resistive) element, or the like. Further, it is not limited to the type in which the electric resistance changes due to the change in the magnetic field, and may be a Hall element, for example.

<Modification 3>
In the first embodiment, as the wiring board 97, the one in which the conductive member 97d integrated with the external terminal 97c is embedded in the base member 97f is preferably used, but the wiring board 97 is not limited to this, and is generally used, for example. You may use what mounted the external terminal 97c on the printed wiring board (PWB, printed wiring board).

<Modification 4>
In the first embodiment, the wiring board 97 and the base member 36 are formed by different members, but both members may be formed by one member. For example, the base member may be provided with the function of a wiring board by embedding a metal member that constitutes an external terminal or a conductive member in the base member.

  The present invention is not limited to the above-mentioned embodiments, and can be appropriately modified without departing from the gist of the present invention.

2 lens holding member 3 support member M5 driving mechanism 35 coil 55 driving magnet 75 yoke 75A outer peripheral wall portion 75C inner wall portion 75T upper plate portion 75k corner portion 6 housing 16 case member 36 base member K7 position detecting means 57 detection magnet 77 Magnetic detection member RE Magnetoresistive effect element 97 Wiring board KD Optical axis direction 101 Lens drive device

Claims (4)

A cylindrical lens holding member capable of holding the lens body,
A supporting member for supporting the lens holding member so as to be movable in the optical axis direction,
A drive mechanism for moving the lens holding member along the optical axis direction,
In a lens driving device comprising: a position detecting unit that detects a position of the lens holding member in the optical axis direction,
The position detection unit is configured to include a detection magnet fixed to the lens holding member, and a magnetic detection member that detects a magnetic field generated by the detection magnet,
The drive mechanism includes a coil wound around the lens holding member, a plurality of drive magnets disposed outside the coil, and a plurality of drive magnets provided integrally with the drive magnet. And a yoke,
The yoke is made of a metal plate having magnetism, have a peripheral wall portion positioned outside of the coil and the driving magnet,
Wherein the outer peripheral wall, in plan view, is formed in a substantially rectangular shape having four corners, along with being notched Oite the position corresponding to the detected magnet, corresponding to the previous SL-detecting magnet It is formed continuously except the part where
The yoke includes an inner wall portion facing the corner portion with the driving magnet and the coil interposed therebetween, and an upper plate portion connected to the inner wall portion and the corner portion of the outer peripheral wall portion. Prepare,
The lens driving device is characterized in that a width dimension of a portion connecting the upper plate portion and the corner portion is formed to be smaller than a width dimension of the inner wall portion . Claim 1, characterized in that it comprises a housing configured by a base member is integrated with the case member is disposed on the lower side of the case member and the lens holding member which houses so as to cover the yoke The lens driving device according to. Together with the detecting magnet is fixed to a lower portion of the lens holding member, according to claim 2, wherein the wiring board having the magnetic detection member is characterized in that provided on the lower side of the detecting magnets Lens drive device. The magnetic detection member has a magnetoresistive effect element whose electric resistance changes with a change in magnetic field,
The detection magnet is magnetized to different magnetic poles in the optical axis direction,
4. The lens driving device according to claim 3 , wherein the center of the detection magnet and the center position of the magnetoresistive effect element are deviated when viewed from the optical axis direction.