JP2018004718A - Lens drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens drive device capable of coping with acceleration of an autofocus.SOLUTION: A lens drive device comprises: a lens holding member 2; an energizing member 3 movably supporting the lens holding member 2; a fixed side member R4 including a housing 4 for housing the lens holding member 2; a coil 35 wound around the lens holding member 2; a plurality of driving magnets 55 magnetized with magnetic poles which differ between an inner side facing the coil 35 and an outer side opposite to the inner side; and position detecting means K7 for detecting a position of the lens holding member 2. The position detecting means K7 has: a detecting magnet 75 fixed to the lens holding member 2; and a magnetism detecting member 77 provided to face the detecting magnet 75. The detecting magnet 75 has: a first magnetized part MG1 magnetized with magnetic poles different from each other in an optical axis direction KD; and a second magnetized part MG2 magnetized to become a magnetic pole opposite to the first magnetized part MG1. The first magnetized part MG1 and the second magnetized part MG2 are provided to be adjacent to each other.SELECTED DRAWING: Figure 5

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. And the lens drive device, which is the main part of the camera mechanism mounted on this small portable device, is used for autofocus to shoot still images or moving images. There has been an increasing demand for driving a lens body (a lens barrel on which a lens is mounted) well. As a lens driving device that satisfies these two requirements, a lens driving device provided with a magnetic circuit for driving a lens holder (lens holding member) for holding a lens body is well known.

  As the lens driving device described above, Patent Document 1 (conventional example) proposes a lens driving device 900 as shown in FIG. FIG. 14 is an exploded perspective view for explaining a conventional lens driving device 900.

  A lens driving device 900 shown in FIG. 14 includes a base member 901 in which a metal plate member is embedded, a lens holder 903 that can hold a lens body (not shown), and a coil 904 in which a metal wire is wound around the lens holder 903. , Four magnets 905 arranged to face the coil 904 at equal intervals, and an elastic member (a lower leaf spring 906 and a lower leaf spring 906 and the lens holder 903 movably supported in the optical axis direction (Z direction shown in FIG. 14)). The upper plate spring 907), a yoke 908 made of a metal plate material, and a spacer member 909 formed in an annular shape are provided. When the lens driving device 900 is assembled, the base member 901 and the yoke 908 are integrated, and a lens holder (lens holding member) 903, a coil 904, four magnets 905, and the like are accommodated in the accommodation space. .

  Further, the lens driving device 900 holds a lens body (not shown) on the lens holder 903, and is mounted on a mounting substrate on which an imaging element (not shown) is mounted. Then, the lens driving device 900 can adjust the focal length by driving the lens held by the lens body in the optical axis direction (Z direction shown in FIG. 14) with respect to the imaging element. At that time, a magnetic circuit is formed by the four magnets 905 disposed at the four corners of the yoke 908, the coil 904, and the yoke 908, and the lens holder 903 is moved in the optical axis direction by electromagnetic force generated by energizing the coil 904. To move along.

Utility Model Registration No. 3179634

  By the way, recently, it has been desired to focus quickly when shooting with autofocus. Therefore, in the lens driving device, it has been required to increase the autofocus speed, that is, to drive faster in the optical axis direction. However, in the conventional lens driving device 900, since the detailed position of the lens holder 903 in the optical axis direction is not controlled, it takes a long time to determine the position of the lens body (lens holder 903), and autofocusing is performed. There is a problem that it is difficult to cope with the increase in the speed.

  The present invention solves the above-described problems, and an object of the present invention is to provide a lens driving device that can cope with high-speed autofocusing.

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 biasing member that supports the lens holding member so as to be movable in the optical axis direction,
A fixed-side member including a housing for housing the lens holding member, an annular coil wound around the lens holding member, and a plurality of driving magnets arranged to face the coil and fixed to the fixed-side member And a position detecting means for detecting the position of the lens holding member in the optical axis direction, and the position detecting means is a detection magnet fixed to the lens holding member, A magnetic detection member provided opposite to the detection magnet, and the drive magnet is magnetized on different magnetic poles on the inner side facing the coil and on the outer side opposite to the inner side. A first magnetized portion magnetized with magnetic poles different from each other in the optical axis direction, and a second magnetized so that the first magnetized portion is a magnetic pole opposite to the first magnetized portion. A magnetic part, and the first magnetized part and the magnetic part 2 and magnetized is characterized in that provided adjacent.

  According to this, the lens driving device of the present invention can cancel the interference of the magnetic field between the detection magnet and the drive magnet, and suppress the influence of the magnetic field from the detection magnet received by the drive magnet. it can. For this reason, it is suppressed that postures, such as a height position of a lens holding member, and inclination, are influenced by a magnet for detection. Thus, the position detection unit reliably detects the position of the lens holding member in the optical axis direction, and when the lens holding member moves, the lens holding member can be quickly and reliably moved to a predetermined position. it can. Therefore, it is possible to provide a lens driving device that can cope with high-speed autofocus.

  The lens driving device according to the present invention is characterized in that the magnetic detection member is disposed at a position closer to the first magnetized portion than the second magnetized portion.

  According to this, a magnetic detection member will not be arrange | positioned in the position where the magnetic field of a 1st magnetized part and a 2nd magnetized part cancels. For this reason, the magnetic field from the 1st magnetization part located nearer can be detected reliably with a magnetic detection member. Thus, the position of the lens holding member can be adjusted reliably, and the lens holding member can be quickly and reliably moved to a predetermined position.

  Further, in the lens driving device according to the present invention, the casing is formed in a rectangular parallelepiped shape, and the driving magnets are arranged one by one at a pair of corners located diagonally of the casing with the optical axis in between. The detection magnet is arranged on the lens holding member at a position corresponding to another corner portion different from the pair of corner portions of the casing.

  According to this, the driving force in the optical axis direction created by the coil and the driving magnet can be applied to the lens holding member with a good balance. Further, the distance between the detection magnets and the respective drive magnets can be the same and longer. For this reason, the influence of the magnetic field from the detection magnet can be reduced evenly with respect to the respective drive magnets, and the influence of the posture of the lens holding member can be prevented.

  In the lens driving device of the present invention, the detection magnet is composed of a single magnet having the first magnetized portion and the second magnetized portion.

  According to this, compared with the case where it comprises with two magnets, while being able to arrange | position a detection magnet easily, it can produce cheaply.

  In the lens driving device according to the present invention, the detection magnet includes two magnets, a first magnet having the first magnetized portion and a second magnet having the second magnetized portion. It is characterized by being.

  According to this, compared with the case where it comprises with one magnet, it becomes easy to obtain the big magnetic force from the magnet for a detection, and can detect the detection accuracy of the position of a lens holding member.

  The lens driving device of the present invention is characterized in that the magnetic detection member is disposed on a side of the lens holding member.

  According to this, a height dimension can be made small.

  In the lens driving device of the present invention, the housing includes a case having a side wall portion, and a base member that is integrated with the case and provided with a power supply terminal for energizing the coil. The plate member having a plurality of external terminals mounted with the magnetic detection member and electrically connected to the magnetic detection member is exposed to the outside of the case, and the side wall It is arrange | positioned in the said housing | casing so that the inner surface of a part may be followed, and the said electric power feeding terminal and the said external terminal are arranged in a line, It is characterized by the above-mentioned.

  According to this, the magnetic detection member can be easily disposed on the side of the lens holding member. In addition, since the power feeding terminals and the external terminals are arranged in a line, the layout of the mounting substrate on which the lens driving device is mounted becomes easy.

  The lens driving device of the present invention can cancel the magnetic field interference between the detection magnet and the drive magnet, and can suppress the influence of the magnetic field from the detection magnet received by the drive magnet. For this reason, it is suppressed that postures, such as a height position of a lens holding member, and inclination, are influenced by a magnet for detection. Thus, the position detection unit reliably detects the position of the lens holding member in the optical axis direction, and when the lens holding member moves, the lens holding member can be quickly and reliably moved to a predetermined position. it can. Therefore, it is possible to provide a lens driving device that can cope with high-speed autofocus.

It is a disassembled perspective view explaining the lens drive device of 1st Embodiment of this invention. It is a perspective view explaining the lens drive device of a 1st embodiment of the present invention. FIGS. 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 when FIG. 2 is viewed from the Z1 side, and FIG. It is the front view seen from the side. 4A and 4B are diagrams illustrating the lens driving device according to the first embodiment of the present invention, in which FIG. 4A is a perspective view in which the case illustrated in FIG. 2 is omitted, and FIG. It is the perspective view which further abbreviate | omitted the frame-shaped member shown in FIG. 5A and 5B are diagrams illustrating the lens driving device according to the first embodiment of the present invention, in which FIG. 5A is a side view of FIG. 4A viewed from the X1 side, and FIG. It is the side view which looked at 4 (b) from the X1 side. 6A and 6B are diagrams illustrating the lens driving device according to the first embodiment of the present invention, in which FIG. 6A is a bottom view when FIG. 2 is viewed from the Z2 side, and FIG. It is the bottom view which abbreviate | omitted the base member shown to (). It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is sectional drawing in the VII-VII line shown to Fig.3 (a). FIGS. 8A and 8B are views for explaining a lens holding member of the lens driving device according to the first embodiment of the present invention. FIG. 8A is a perspective view of the lens holding member, and FIG. It is the perspective view by which the coil was wound around the lens holding member shown to a). FIG. 9A is a diagram illustrating an urging member of the lens driving device according to the first embodiment of the present invention, and FIG. 9A is a top view of the upper leaf spring shown in FIG. 9 (b) is a top view of the lower leaf spring shown in FIG. 1 viewed from the Z1 side. FIG. 10A is a perspective view of a base member of the lens driving device according to the first embodiment of the present invention, and FIG. 10B is a perspective view of the base member. It is a perspective view which shows the state by which the lower leaf | plate spring was mounted in the base member. It is a figure explaining the drive mechanism of the lens drive device concerning 1st Embodiment of this invention, Comprising: It is the bottom view which abbreviate | omitted the lower leaf | plate spring and lens holding member which were shown in FIG.6 (b). FIGS. 12A and 12B are views for explaining position detection means of the lens driving device according to the first embodiment of the present invention, FIG. 12A is a perspective view of the position detection means, and FIG. It is a perspective view of the position detection means seen from the Y1 side shown to a). It is a figure explaining the position detection means of the lens drive device concerning 1st Embodiment of this invention, Comprising: It is an enlarged side view of the P section shown to Fig.5 (a). It is a disassembled perspective view of the lens drive device 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 the 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 as viewed from the Z1 side in FIG. 2, and FIG. 3B is a front view of the lens driving device 101 as viewed from the Y2 side in FIG. 4A is a perspective view in which the case 14 which is the fixed side member R4 of the lens driving device 101 shown in FIG. 2 is omitted, and FIG. 4B is a frame-like member 44 shown in FIG. And is a perspective view further omitting the position detection means K7. 5A is a side view of FIG. 4A viewed from the X1 side, and FIG. 5B is a side view of FIG. 4B viewed from the X1 side. 6A is a bottom view of the lens driving device 101 as viewed from the Z2 side in FIG. 2, and FIG. 6B is a bottom view in which the base member 8 shown in FIG. 6A is omitted. FIG. 7 is a cross-sectional view taken along line VII-VII shown in FIG. 5 and 7 show an initial state in which no current is passed through the coil 35. FIG.

  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 6A. As shown in FIGS. (Not shown) including a cylindrical lens holding member 2, a biasing member 3 that supports the lens holding member 2 so as to be movable in the optical axis direction KD, and a housing 4 that houses the lens holding member 2. A fixed-side member R4, a drive mechanism M5 that moves the lens holding member 2 along the optical axis direction KD (Z direction shown in FIG. 2), and a position detection unit that detects the position of the lens holding member 2 in the optical axis direction KD. K7.

  In the first embodiment of the present invention, the urging member 3 includes an upper leaf spring 3A fixed to the upper portion of the lens holding member 2, as shown in FIGS. 4B and 5B, and FIG. As shown in FIG. 5 and FIG. 6B, the lens holding member 2 is supported by two lower leaf springs 3 </ b> C and 3 </ b> E fixed to the lower portion of the lens holding member 2. .

  In addition to the housing 4 described above, the fixed member R4 is located above the lens holding member 2 (Z1 direction shown in FIG. 4A), as shown in FIGS. 4A and 5A. The frame-shaped member 44 is disposed. Further, the housing 4 of the fixed side member R4 is formed in a rectangular parallelepiped shape, and as shown in FIG. 1, the case 14 whose outer shape is formed in a box shape and the case 14 as shown in FIG. And a base member 8.

  4 and 7, the driving mechanism M5 includes an annular coil 35 wound around the lens holding member 2 and two driving magnets 55 arranged to face the coil 35. ing.

  Further, as shown in FIGS. 4A and 5A, the position detection means K7 includes a detection magnet 75 fixed to the lens holding member 2 and a magnet provided to face the detection magnet 75. A detection member 77 and a plate member 79 on which the magnetic detection member 77 is mounted are provided.

  The lens driving device 101 holds a lens body (not shown) on the lens holding member 2 and is mounted on a mounting board (not shown) on which an imaging element is mounted. In order to adjust the focal length by driving the lens held by the lens body in the optical axis direction KD (Z direction shown in FIG. 2), the lens driving device 101 is supplied with current from the power source to the coil 35. The lens holding member 2 is moved along the optical axis direction KD with respect to the image pickup device by the generated electromagnetic force.

  Next, each component will be described in detail. First, the lens holding member 2 of the lens driving device 101 will be described. 8A and 8B are diagrams for explaining the lens holding member 2. FIG. 8A is a perspective view of the lens holding member 2, and FIG. 8B is a lens holding member shown in FIG. 8A. 2 is a perspective view in which a coil 35 is wound around 2. FIG.

  The lens holding member 2 of the lens driving device 101 uses a liquid crystal polymer (LCP, Liquid Crystal Polymer), which is one of synthetic resins, and is formed in a cylindrical shape as shown in FIG. A cylindrical portion 12 having a peripheral surface and a rectangular outer peripheral surface (circular shape on the upper end side), and a flange portion 22 protruding radially outward from an outer peripheral surface on the upper end side (Z1 side shown in FIG. 4) of the cylindrical portion 12; The flange portion 32 is provided opposite to the flange portion 22 and protrudes radially outward from the outer peripheral surface of the lower end (Z2 side shown in FIG. 4) of the cylindrical portion 12. And the lens holding member 2 is arrange | positioned above the base member 8 (Z1 direction shown in FIG. 4), as shown in FIG.

  As shown in FIG. 8, the cylindrical portion 12 of the lens holding member 2 has a female screw portion 12n formed on the inner peripheral surface thereof, and a lens body (not shown) is mounted and held on the female screw portion 12n. Further, as shown in FIG. 8A, the outer peripheral surface of the cylindrical portion 12 is formed in an octagonal shape between the flange portion 32 and the flange portion 22, as shown in FIG. 8B. Further, the coil 35 is wound in an octagon shape supported by the outer peripheral surface.

  Moreover, as shown in FIG. 8, the base part 12d is formed in two places facing the outer peripheral surface of the cylinder part 12 above the collar part 22. As shown in FIG. When the lens driving device 101 is assembled, as shown in FIG. 4 (b), two pedestal portions 12d (lens holding members 2) that face each other (in the X direction shown in FIG. 4 (b)). The upper leaf spring 3A (first portion 13 described later) of the urging member 3 is fixed with an adhesive.

Further, on the bottom surface of the lens holding member 2 on the collar portion 32 side, as shown in FIG. 6B, a columnar shape protruding downward (in FIG. 6B, in the Z2 direction shown in FIG. 8 in front of the paper surface). The protruding portions 12t are provided at four places (two protruding portions 12t ₁ and two protruding portions 12t ₂ ). Then, when the lens driving device 101 is assembled, as shown in FIG. 6 (b), together with the two convex portions 12t ₁ is engaged with the lower leaf spring 3C (third portion 33 to be described later), two convex portions 12t ₂ engages the lower leaf spring 3E (third portion 33 to be described later).

  Further, as shown in FIG. 6B, the bottom surface of the lens holding member 2 is provided with two rectangular columnar binding portions 12k protruding downward. Each of the coil end portions of the coil 35 is wound around the binding portion 12k and soldered to the two lower leaf springs 3C and 3E. In FIG. 6B, the solder HD in which two coil ends, the lower leaf spring 3C, and the lower leaf spring 3E are soldered is schematically shown by cross hatching surrounded by a broken line.

  Next, the urging member 3 of the lens driving device 101 will be described. FIG. 9 is a diagram illustrating the urging member 3. FIG. 9 (a) is a top view of the upper leaf spring 3A shown in FIG. 1 as viewed from the Z1 side, and FIG. 3 is a top view of the lower leaf spring 3C and the lower leaf spring 3E shown in FIG.

  The urging member 3 of the lens driving device 101 is made of a metal plate made of a copper alloy as a main material, and as shown in FIG. 4 (b), from the inner peripheral surface of the cylindrical portion 12 of the lens holding member 2. Also has an upper leaf spring 3A disposed between the lens holding member 2 and the frame-shaped member 44, and two members disposed between the lens holding member 2 and the base member 8. The lower leaf spring 3C and the lower leaf spring 3E are configured. Then, a part of each of the biasing members 3 (upper leaf spring 3A, lower leaf spring 3C, lower leaf spring 3E) is fixed to the lens holding member 2, and the lens holding member 2 is in the optical axis direction KD (FIG. 2). The urging member 3 supports the lens holding member 2 in the air so as to be movable in the Z direction shown in the drawing. 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. It also has a function as

  First, as shown in FIG. 9A, the upper plate spring 3A of the urging member 3 has a substantially rectangular outer shape and is fixed to the lens holding member 2 (first embodiment of the present invention). Two portions) in the form), four second portions 23 positioned on the outer peripheral side of the first portion 13 and fixed to the stationary member R4 (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 and connected from the first portion 13, and the four second portions 23 to each other And a crosspiece 73 that connects the two. The first portion 13 and the connecting portion 63 form an annular shape inside, and the second portion 23 and the crosspiece 73 form a rectangular shape outside.

  When the upper leaf spring 3A is incorporated in the lens driving device 101, as shown in FIG. 4B, the first portion 13 is placed on the pedestal portion 12d of the lens holding member 2, and the first portion By fixing 13 and the pedestal portion 12d with an adhesive, one side of the upper leaf spring 3A is fixed to the lens holding member 2. In addition,

  On the other hand, as shown in FIG. 7, the two portions of the second portion 23 are in contact with the upper surface of the drive magnet 55 (see FIGS. 4B and 5), and together with the frame-shaped member 44, It is sandwiched between the magnet 55 and the case 14. The driving magnet 55 is fixed to the case 14 with an adhesive. Further, although not shown, the other two second portions 23 are fixed to the lower surface of the frame-shaped member 44 with an adhesive, so that the other side of the upper leaf spring 3A is fixed.

  In this way, the upper leaf spring 3 </ b> A is configured in a substantially line-symmetric shape as shown in FIG. 9A, and two equal positions of the first portion 13 with respect to the lens holding member 2. (See FIG. 4), and fixed at four equal positions of the second portion 23 with respect to the stationary member R4 (case 14 and frame-like member 44) (see FIG. 7). ). Thereby, the lens holding member 2 can be supported in the air with good balance.

  Next, as shown in FIG. 9B, the lower leaf spring 3C and the lower leaf spring 3E of the urging member 3 have a substantially rectangular outer shape and a semicircular shape inside each lens. Four third portions 33 fixed to the holding member 2, four fourth portions 43 fixed to the base member 8 (see FIG. 10B described later), third portions 33 and fourth Two elastic arm portions 53c and 53e positioned between the portion 43, a first linkage portion 83 that connects two third portions 33, and a second link portion that connects two fourth portions 43, respectively. 2 chain parts 93.

  Further, as shown in FIG. 9B, circular through holes 33k are respectively formed in the third portions 33 of the lower leaf spring 3C and the lower leaf spring 3E. In addition, circular through holes 43m are formed in the fourth portions 43 of the lower leaf spring 3C and the lower leaf spring 3E, respectively, and rectangular through holes 43s and through holes 43t are formed in one place. .

When the lower leaf spring 3C and the lower leaf spring 3E are incorporated into the lens driving device 101, as shown in FIG. 6B, the two protruding portions 12t ₁ (12t) of the lens holding member 2 are provided. Is inserted through and fitted into the through hole 33k (see FIG. 9B) of the lower leaf spring 3C, and the two protruding portions 12t ₂ (12t) of the lens holding member 2 are connected to the lower leaf spring 3E. The through-hole 33k (see FIG. 9B) is inserted and fitted. Accordingly, one side of the lower leaf spring 3 </ b> C and the lower leaf spring 3 </ b> E 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 caulked 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 protruding portion 18t (see FIG. 1) provided on the upper surface of the base member 8 to be described later is inserted into a through hole 43m (see FIG. 9B) of the lower leaf spring 3C and the lower leaf spring 3E. Are mated. Thereby, the other side of the lower leaf spring 3 </ b> C and the lower leaf spring 3 </ b> E is positioned on the base member 8 and is fixed to the base member 8.

  In this way, the lower leaf spring 3C and the lower leaf spring 3E are configured in a substantially line-symmetric shape as shown in FIG. 9B, and the third portion 33 of the lens holding member 2 is formed. While being connected at four equal positions, it is connected to the base member 8 at four equal positions of the fourth portion 43. Thereby, the lens holding member 2 can be supported in the air with good balance. Therefore, the biasing 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 fixed side member R4 of the lens driving device 101 will be described. FIG. 10A is a perspective view of the base member 8, and FIG. 10B shows a state in which the lower leaf spring 3C and the lower leaf spring 3E are placed on the base member 8 of FIG. 10A. It is a perspective view.

  The fixed side member R4 is a member having a function of fixing a part of the urging member 3 that supports the lens holding member 2 so as to move while the lens holding member 2 moves along the optical axis direction KD. That is, in the first embodiment of the present invention, as shown in FIG. 1, the fixed-side member R4 includes the case 14 that fixes the second portion 23 of the upper leaf spring 3A with the driving magnet 55, A frame-shaped member 44 to which the second portion 23 of the upper leaf spring 3A is fixed with an adhesive, and a base member 8 to which the fourth portion 43 of the lower leaf spring 3C and the lower leaf spring 3E is fixed. ing. In the first embodiment of the present invention, the other side of the upper leaf spring 3A is fixed by sandwiching the two portions of the second portion 23 of the upper leaf spring 3A between the frame-shaped member 44 and the driving magnet 55. Therefore, the driving magnet 55 can also be referred to as a fixed-side member R4 that fixes a part of the biasing member 3.

  First, the case 14 of the fixed side member R4 will be described. The case 14 is manufactured by cutting, drawing or the like using a metal plate made of a non-magnetic metal material. The outer shape as shown in FIG. 1 is formed in a box shape, and FIG. It has a substantially rectangular shape as shown (in plan view). And the case 14 is a part which connects the flat side wall part 14A, the flat plate upper plate part 14B provided continuously with the upper end (Z1 side shown in FIG. 1) of the side wall part 14A, and the side wall part 14A. 14C, and a substantially circular opening 14k is formed in the upper plate portion 14B.

  2, the case 14 includes a lens holding member 2, a biasing member 3 (upper leaf spring 3A, lower leaf spring 3C, lower leaf spring 3E), a frame member 44, and a drive mechanism M5 (coil 35). These members are accommodated so as to cover the drive magnet 55), and are engaged with the base member 8 disposed below (Z2 direction shown in FIG. 2), and are integrated with the base member 8. .

  Next, the frame-shaped member 44 of the fixed side member R4 will be described. The frame-shaped member 44 is a frame body that uses a synthetic resin such as polybutylene terephthalate (PBT) and has a rectangular opening 44k in the center and has a substantially rectangular shape as shown in FIG. The frame-shaped member 44 includes a first extending portion 44A which is a set of sides facing each other, a second extending portion 44B which is another set of sides intersecting with the set of sides, A corner side portion 44C that connects the first extending portion 44A and the second extending portion 44B is provided.

  When the frame-like member 44 is incorporated into the lens driving device 101, it is disposed above the upper leaf spring 3A as shown in FIGS. As shown, the second portion 23 of the upper leaf spring 3 </ b> A is sandwiched between the corner side portions 44 </ b> C of the frame-shaped member 44 arranged diagonally and the driving magnet 55. 4A, the first extending portion 44A of the frame-like member 44 extends along the outer peripheral side of the connecting portion 63 of the upper leaf spring 3A, and the second extension of the frame-like member 44. The intermediate portion of the extending portion 44B is positioned to face the first portion 13 of the upper leaf spring 3A.

Next, the base member 8 of the fixed side member R4 will be described. The base member 8 is manufactured by injection molding using the same synthetic resin material as the lens holding member 2 such as a liquid crystal polymer (LCP). As shown in FIG. And is formed in an annular shape having a circular opening 8k at the center. Further, as shown in FIG. 10A, four projecting portions 18 t (two projecting portions 18 t ₁ and two projecting portions 18 t ₂ ) projecting upward are formed on the upper surface of the base member 8. It is provided at the four corners. As described above, as shown in FIG. 10 (b), the protruding portion 18t is inserted into the through hole 43m (see FIG. 9 (b)) of the lower leaf spring 3C and the lower leaf spring 3E. Combined. At this time, the caulking portion 18t of the base member 8 is heat caulked to more reliably fix the lower leaf spring 3C and the lower leaf spring 3E to the base member 8.

  Further, as shown in FIG. 10 (a), the base member 8 includes three terminals T9 (a power supply terminal T9C, a power supply terminal) made of a metal plate made of a material such as copper, 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 imaging element (not shown) is mounted, and can supply power from the electrode land of the mounting board, It is designed to be grounded to the land. That is, the power supply terminal T9C and the power supply terminal T9E are connected to the power source, and the ground terminal T9G is connected to the ground.

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

  Further, although not shown in detail in the base member 8, a connecting member 59 made of a metal plate using a material such as copper, iron, or an alloy containing them as a main component is also the same as the three terminals T9. The part of the connection member 59 is partially exposed at the four corners of the case 14 as shown in FIG. Then, after the inner wall of the side wall portion 14A of the case 14 and the outer peripheral side surface of the base member 8 are combined and positioned, four joint portions between the connection member 59 of the base member 8 and the four corners of the case 14 are welded, 14 is fixed to the base member 8. Note that at least a part of the connection member 59 is formed integrally with the ground terminal T9G. For this reason, the case 14 can be grounded via the connection member 59 and the ground terminal T9G.

  Next, the driving mechanism M5 of the lens driving device 101 will be described. FIG. 11 is a view illustrating the drive mechanism M5, and 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. 6B are omitted. FIG. 11 shows the case 14, the frame-like member 44, the upper leaf spring 3A, the drive mechanism M5, and the position detection means K7.

  The drive mechanism M5 has a function of moving the lens holding member 2 along the optical axis direction KD (Z direction shown in FIG. 1), and is wound around the lens holding member 2 as shown in FIG. The annular coil 35 is provided, and two drive magnets 55 arranged opposite to the coil 35.

  First, the coil 35 of the driving mechanism M5 is made of a metal wire having an insulating coating (coating) on the outer periphery, and is wound around the outer periphery of the lens holding member 2 as shown in FIG. As shown in FIG. 2, it is formed in a substantially octagonal annular shape. In that case, the coil 35 is arrange | positioned between the collar part 22 and the collar part 32, as shown in FIG.8 (b), and is supported and fixed to the rectangular-shaped outer peripheral surface from the inner side. The coil 35 has a shape in which a metal wire is wound and bundled. However, in FIG. 1, FIG. 4, FIG.

  The coil 35 is electrically conductive at both ends of the wound metal wire, and as described above, each of the coil ends has two lower ends as shown in FIG. 6 (b). The side leaf spring 3C and the lower leaf spring 3E are soldered and electrically connected.

  Next, as the drive magnet 55 of the drive mechanism M5, for example, two samarium cobalt magnets are used, and as shown in FIG. 11, a pair of corners positioned diagonally to the housing 4 (case 14) across the optical axis. One each is disposed in the portion 14C and is disposed opposite to the coil 35. Further, the drive magnet 55 has a trapezoidal cross section so that the drive magnet 55 is efficiently arranged at the corner portion 14C, the upper base faces the corner portion 14C, and the lower base is a coil. 35, and the leg has a shape along the side wall portion 14A. The drive magnet 55 has its legs pressed against the side wall portion 14A, and is fixed to the case 14 that is the stationary member R4 with an adhesive. The driving magnet 55 is magnetized so as to have different magnetic poles on the inner side (the trapezoidal lower bottom side) facing the coil 35 and on the outer side (the trapezoidal upper bottom side) opposite to the inner side. Yes.

  As described above, since the lens holding member 2 and the coil 35, the case 14, and the driving magnet 55 are arranged, the lens driving device 101 is configured such that a current is passed from the power source to the coil 35. Due to the generated electromagnetic force, a thrust acts on the coil 35 corresponding to the direction in which the current flows, and the lens holding member 2 moves up and down. In addition, in the first embodiment of the present invention, the driving magnet 55 is disposed on each of the pair of corner portions 14C located diagonally of the housing 4 with the optical axis in between, so that the coil 35 and the drive are driven. The driving force in the optical axis direction KD created by the magnet 55 can be applied to the lens holding member 2 with a good balance.

  Finally, the position detection unit K7 of the lens driving device 101 will be described. FIG. 12A is a perspective view of the position detection means K7, and FIG. 12B is a perspective view of the position detection means K7 viewed from the Y1 side shown in FIG. 12A. FIG. 13 is a diagram for explaining the position detection means K7, and is an enlarged side view of a portion P shown in FIG. 5 (a). 5A, 12 and 13, the boundary line between the magnetized magnetic poles is indicated by a two-dot chain line.

  As shown in FIG. 12, the position detection means K7 is fixed to the lens holding member 2 (see FIG. 4A and FIG. 5A) and faces the detection magnet 75 and the detection magnet 75. The magnetic detection member 77 is provided, and a plate-like member 79 on which the magnetic detection member 77 is mounted.

  First, the detection magnet 75 of the position detection means K7 is formed in a rectangular parallelepiped shape using, for example, one samarium cobalt magnet, and is disposed on the flange portion 32 of the lens holding member 2 as shown in FIG. And is fixed by an adhesive. As a result, the detection magnet 75 moves as the lens holding member 2 moves.

  Further, as shown in FIGS. 12 and 13, the detection magnet 75 includes a first magnetized portion MG1 magnetized with different magnetic poles in the optical axis direction KD, and is opposite to the first magnetized portion MG1. A second magnetized portion MG2 magnetized so as to be a magnetic pole, and the first magnetized portion MG1 and the second magnetized portion MG2 are provided adjacent to each other. Specifically, as shown in FIG. 13, the first magnetized portion MG1 on the side close to the magnetic detection member 77 is magnetized with the S pole on the upper side and the N pole on the lower side, and the second magnetized portion MG2 is The upper side is magnetized to the N pole and the lower side is magnetized to the S pole so that the magnetic pole is opposite to the first magnetized portion MG1. Thereby, interference of the magnetic field of the detection magnet 75 and the drive magnet 55 can be canceled, and the influence of the magnetic field from the detection magnet 75 which the drive magnet 55 receives can be suppressed. This is because when a magnet magnetized with a pair of N pole and S pole is used, the magnetic fields of the detection magnet 75 and the drive magnet 55 interfere with each other, and this interference causes the lens in the initial state. The problem that the displacement of the height position of the holding member 2 occurs or the posture of the lens holding member 2 is inclined is solved.

  Further, in the first embodiment of the present invention, as shown in FIG. 11, the detection magnet 75 is a pair of corner portions 14C of the casing 4 (case 14) (the corner portions 14C where the drive magnet 55 is disposed). ) Is disposed at a position corresponding to another corner portion 14C different from (). As a result, the distance between the detection magnet 75 and each drive magnet 55 can be made approximately the same and longer. For this reason, the influence of the magnetic field from the detection magnet 75 can be reduced evenly with respect to the respective drive magnets 55, and the posture of the lens holding member 2 can be made less affected. .

  In the first embodiment of the present invention, since the detection magnet 75 is composed of one magnet, the detection magnet 75 can be easily disposed as compared with the case where the magnet is composed of two magnets. Can be manufactured cheaply.

  Next, the magnetic detection member 77 of the position detection means K7 uses a Hall element that detects a change in magnetism, and only four terminal portions (two terminal portions on one side are shown in FIG. 12B). , 77a and 77b) are exposed to the outside and formed with a package incorporating this Hall element.

  Further, the magnetic detection member 77 is soldered to four conductive members 79 d of a plate-like member 79 described later, and is fixed to the plate-like member 79 so as to face the detection magnet 75. Thereby, it becomes the structure which arrange | positions the magnetic detection member 77 to the side of the lens holding member 2, and can make a height dimension small compared with the case where it arrange | positions to the upper side or the lower side of the lens holding member 2. FIG. The magnetic sensitive direction of the Hall element is the Y direction shown in FIG.

  The magnetic detection member 77 is generated by the detection magnet 75 fixed to the lens holding member 2, and can detect a change in the magnetic field due to the movement in the optical axis direction KD. For this reason, 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 can adjust the actual position of the lens holding member 2. Accordingly, the lens holding member 2 that has been adjusted and whose position is clear can be quickly moved to a predetermined position such as a position where the image is focused. Accordingly, the time until the position of the lens holding member 2 is determined can be shortened, and the lens holding member 2 can be quickly and reliably moved to a predetermined position.

  Further, since the magnetic detection member 77 is disposed at a position closer to the first magnetized part MG1 than to the second magnetized part MG2, the magnetic fields of the first magnetized part MG1 and the second magnetized part MG2 cancel out. The magnetic detection member 77 is not disposed at the matching position. For this reason, the magnetic detection member 77 can reliably detect the magnetic field from the first magnetized portion MG1. Thereby, the position of the lens holding member 2 can be adjusted reliably, and the lens holding member 2 can be quickly and reliably moved to a predetermined position.

  Next, as shown in FIG. 12B, the plate-like member 79 of the position detecting means K7 is formed integrally with four external terminals 79c formed of a conductive metal member and this external terminal 79c. A conductive member 79d for forming a pattern and a base material portion 79f for exposing the external terminal 79c and embedding the conductive member 79d are provided. A magnetic detection member 77 is mounted on the plate-like member 79, and the four external terminals 79c of the plate-like member 79 are electrically connected via the magnetic detection member 77 and the conductive member 79d.

  Further, when the lens driving device 101 is assembled, the plate-like member 79 is disposed in the housing 4 along the inner surface of the side wall portion 14A of the case 14, as shown in FIG. As shown in FIG. 2, the external terminal 79 c is exposed to the outside of the case 14. The four external terminals 79c are electrically connected together with the terminal T9 of the base member 8 to an electrode land of a mounting board on which an imaging element (not shown) is mounted. Thereby, the magnetic detection member 77 can be easily disposed on the side of the lens holding member 2. In addition, since the three terminals T9 (the power supply terminal T9C, the power supply terminal T9E, and the ground terminal T9G) and the external terminal 79c are arranged in a line (see FIG. 6A), the lens driving device 101 is mounted. The layout of the substrate and the like becomes easy. The plate member 79 is fixed to at least one of the base member 8 and the case 14 constituting the housing 4 with an adhesive.

  In the position detection means K7 configured as described above, the magnetic flux generated from the detection magnet 75 changes due to the movement of the detection magnet 75 as the lens holding member 2 moves, and the change in the magnetic flux is magnetized. Detection is performed by the detection member 77. Thereby, the position detection 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 supply terminal T9C and the power supply terminal T9E via the lower plate spring 3C and the lower plate spring 3E, the power supply terminal T9C and the power supply terminal are connected. A current can flow from the terminal T9E to the coil 35. On the other hand, the magnetic flux from the driving magnet 55 emits the driving magnet 55, passes through the coil 35, and returns to the driving magnet 55.

  From this initial state, when a current is passed through the coil 35 from the power supply terminal T9C side, an electromagnetic force is generated in the coil 35 from the Z1 direction, which is the optical axis direction KD, to the Z2 direction in accordance with 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 through the coil 35 from the power supply terminal T9E side, an electromagnetic force is generated from the Z2 direction, which is the optical axis direction KD, in the Z1 direction, and the lens holding member 2 moves in the Z1 direction.

  In this way, when the current flows through the coil 35, the lens driving device 101 causes the biasing force of any one of the upper leaf spring 3A, the lower leaf spring 3C, and the lower leaf spring 3E by the electromagnetic force generated in the coil 35. On the other hand, a lens body (not shown) can be integrated with the lens holding member 2 and moved along the optical axis direction KD (Z direction shown in FIG. 2). The current flowing through the coil 35 is controlled based on the positional accuracy of the lens holding member 2 in the optical axis direction KD detected by the position detecting means K7.

  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.

  Since the lens driving device 101 according to the first embodiment of the present invention includes the position detection unit K7 that detects the position of the lens holding member 2 in the optical axis direction KD, the position of the lens holding member 2 can be adjusted. The lens holding member 2 that has been adjusted and whose position is clear can be quickly moved to a predetermined position such as a position where the image is in focus. For this reason, the time until the position of the lens holding member 2 is determined can be shortened. Moreover, even if the detection magnet 75 and the magnetic detection member 77 having a simple configuration are used as the position detection means K7, the detection magnet 75 and the first magnetized portion MG1 in which the magnetic poles in the optical axis direction KD are opposite to each other. Since the two magnetized portions MG2 are provided, the magnetic field interference between the detection magnet 75 and the drive magnet 55 can be canceled out, and the influence of the magnetic field from the detection magnet 75 received by the drive magnet 55 can be suppressed. Can do. For this reason, it can suppress that postures, such as a height position and inclination of the lens holding member 2, are influenced by the magnet 75 for a detection. As a result, the position detecting means K7 reliably detects the position of the lens holding member 2 in the optical axis direction KD, and when the lens holding member 2 is moved, the lens holding member 2 can be quickly moved to a predetermined position. It can be moved reliably. Therefore, it is possible to provide the lens driving device 101 that can cope with high-speed autofocus.

  Further, since the magnetic detection member 77 is disposed at a position closer to the first magnetized part MG1 than to the second magnetized part MG2, the magnetic fields of the first magnetized part MG1 and the second magnetized part MG2 cancel out. The magnetic detection member 77 is not disposed at the matching position. For this reason, the magnetic detection member 77 can reliably detect the magnetic field from the first magnetized portion MG1. Thereby, the position of the lens holding member 2 can be adjusted reliably, and the lens holding member 2 can be quickly and reliably moved to a predetermined position.

  In addition, since the driving magnets 55 are arranged one by one on the pair of corner portions 14C located diagonally of the housing 4 with the optical axis in between, the optical axis direction KD created by the coil 35 and the driving magnet 55 is provided. The driving force can be applied to the lens holding member 2 in a balanced manner. Further, since the detection magnet 75 is disposed at a position corresponding to another corner portion 14C different from the pair of corner portions 14C, the distance between the detection magnet 75 and each drive magnet 55 is approximately the same. Can be longer. For this reason, the influence of the magnetic field from the detection magnet 75 can be reduced evenly with respect to the respective drive magnets 55, and the posture of the lens holding member 2 can be made less affected. .

  Further, since the detection magnet 75 is composed of a single magnet, the detection magnet 75 can be easily arranged and can be manufactured at a lower cost than the case where it is composed of two magnets.

  Further, by adopting a configuration in which the magnetic detection member 77 is disposed on the side of the lens holding member 2, the height dimension can be reduced as compared with the case where it is disposed on the upper side or the lower side of the lens holding member 2. it can.

  In addition, the magnetic detection member 77 can be easily arranged on the side of the lens holding member 2 by arranging the plate-like member 79 on which the magnetic detection member 77 is mounted in the housing 4. In addition, since the power supply terminal T9C, the power supply terminal T9E (including the ground terminal T9G) and the external terminal 79c are arranged in a line, the layout of the mounting substrate on which the lens driving device 101 is mounted becomes easy.

  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 said 1st Embodiment, although it was set as the simple structure using one magnet as the magnet 75 for a detection, it is not restricted to this. For example, the detection magnet 75 may be composed of two magnets, a first magnet having the first magnetized portion MG1 and a second magnet having the second magnetized portion MG2. Thereby, compared with the case where it comprises with one magnet, it becomes easy to obtain the big magnetic force from the magnet 75 for a detection, and the detection accuracy of the position of the lens holding member 2 can be improved.

<Modification 2>
In the first embodiment, the upper side of the first magnetized portion M1 is magnetized to the S pole, the lower side is magnetized to the N pole, the upper side of the second magnetized portion MG2 is magnetized to the N pole, and the lower side is magnetized to the S pole. However, the present invention is not limited to this, and it is only necessary that the first magnetized portion MG1 and the second magnetized portion MG2 are magnetized so as to have opposite magnetic poles in the optical axis direction KD. . For example, the upper side of the first magnetized portion M1 may be magnetized to the N pole, the lower side may be magnetized to the S pole, the upper side of the second magnetized portion MG2 may be magnetized to the S pole, and the lower side may be magnetized to the N pole. .

<Modification 3>
In the first embodiment, as the plate-like member 79, a member in which the conductive member 79d integrated with the external terminal 79c is embedded in the base material portion 79f is preferably used. However, the present invention is not limited to this, and is generally used, for example. A printed wiring board (PWB) on which external terminals 79c are mounted may be used.

<Modification 4>
In the first embodiment, the Hall element is used as the magnetic detection member 77. However, the present invention is not limited to this. For example, a magnetoresistive element whose resistance is changed by a change in magnetism 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.

2 Lens holding member 3 Energizing member 3A Upper leaf spring 3C, 3E Lower leaf spring R4 Fixed member 4 Housing 14 Case 14A Side wall portion 14C Corner portion 35 Coil 55 Driving magnet K7 Position detecting means 75 Detection magnet MG1 1st Magnetized part MG2 Second magnetized part 77 Magnetic detection member 79 Plate member 79c External terminal 8 Base member T9C, T9E Power supply terminal KD Optical axis direction 101 Lens drive device

Claims (7)

A cylindrical lens holding member capable of holding a lens body;
An urging member that supports the lens holding member so as to be movable in the optical axis direction;
A fixed-side member including a housing that houses the lens holding member;
An annular coil wound around the lens holding member;
A plurality of drive magnets arranged opposite to the coil and fixed to the fixed side member;
In a lens driving device comprising:
A position detecting means for detecting a position of the lens holding member in the optical axis direction;
The position detection means includes a detection magnet fixed to the lens holding member, and a magnetic detection member provided to face the detection magnet.
The driving magnet is magnetized with different magnetic poles on the inner side facing the coil and the outer side opposite to the inner side,
The detection magnet includes a first magnetized portion magnetized with magnetic poles different from each other in the optical axis direction, and a second magnetized portion magnetized so as to have a magnetic pole opposite to the first magnetized portion. And having
The lens driving device, wherein the first magnetized portion and the second magnetized portion are provided adjacent to each other.   The lens driving device according to claim 1, wherein the magnetic detection member is disposed closer to the first magnetized portion than the second magnetized portion. The housing is formed in a rectangular parallelepiped shape,
The driving magnets are arranged one by one at a pair of corners located diagonally of the housing across the optical axis,
The said detection magnet is arrange | positioned at the said lens holding member in the position corresponding to the other corner | angular part different from the said pair of corner | angular part of the said housing | casing. Lens drive device.   4. The lens driving device according to claim 1, wherein the detection magnet is configured by a single magnet having the first magnetized portion and the second magnetized portion. 5. .   The detection magnet is composed of two magnets, a first magnet having the first magnetized portion and a second magnet having the second magnetized portion. The lens driving device according to claim 3.   6. The lens driving device according to claim 1, wherein the magnetic detection member is disposed on a side of the lens holding member. The housing includes a case having a side wall portion, and a base member provided with a power supply terminal that is integrated with the case and energizes the coil.
In the state where the magnetic detection member is mounted and the plate-like member having a plurality of external terminals electrically connected to the magnetic detection member is exposed to the outside of the case, the side wall portion The lens driving device according to claim 6, wherein the lens driving device is arranged in the casing along the inner surface of the lens, and the power supply terminal and the external terminal are arranged in a line.