JP6729968B2 - 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. There has been an increasing demand for driving the lens body (lens barrel in which the lens is mounted). 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.

As a 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 illustrating 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 capable of holding 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) which movably supports the lens holder 903 in the optical axis direction (Z direction shown in FIG. 14). The upper leaf spring 907), a yoke 908 made of a metal plate material, and an annular spacer member 909 are provided. Then, when the lens driving device 900 is assembled, the base member 901 and the yoke 908 are integrated, and the lens holding body (lens holding member) 903, the coil 904, the four magnets 905, etc. are housed in the housing space. ..

The lens driving device 900 holds a lens body (not shown) on the lens holding body 903, and is mounted on a mounting board on which an image pickup device (not shown) is mounted. Then, the lens driving device 900 allows the lens held by the lens body to be driven in the optical axis direction (Z direction shown in FIG. 14) with respect to the image pickup element to adjust the focal length. At that time, a magnetic circuit is formed by the four magnets 905 arranged at the four corners of the yoke 908, the coil 904, and the yoke 908, and the electromagnetic force generated by energizing the coil 904 causes the lens holder 903 to move in the optical axis direction. I am trying to move along.

Utility model registration No. 3179634

By the way, in recent years, it has been desired that the focus be adjusted quickly when shooting with autofocus. Therefore, in the lens driving device, speeding up of autofocus, that is, faster driving in the optical axis direction has been demanded. However, in the lens driving device 900 of the conventional example, since the detailed position of the lens holder 903 in the optical axis direction is not controlled, it takes a long time until the position of the lens body (lens holder 903) is set, and the autofocus is performed. There is a problem that it is difficult to cope with the speeding up of the.

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 speeding up of autofocus.

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, an urging member for movably supporting the lens holding member in an optical axis direction, and 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 coils 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, wherein the driving magnet is on the inside facing the coil and on the opposite side of the inside. The position detection means is magnetized to different magnetic poles on the outside and the position detection means includes a detection magnet fixed to the lens holding member, and a magnetic detection member provided so as to face the detection magnet. The detection magnet is magnetized to have magnetic poles different from each other in the optical axis direction, and second magnetized to have magnetic poles opposite to those of the first magnetized portion. A magnetized portion, the first magnetized portion and the second magnetized portion are provided adjacent to each other , and the magnetism detection member is located closer to the first magnetized portion than to the second magnetized portion. It is characterized in that it is arranged in a close position .

According to this, the lens driving device of the present invention can cancel out the interference of the magnetic fields of the detection magnet and the driving magnet, and can suppress the influence of the magnetic field from the detection magnet that the driving magnet receives. it can. Therefore, it is possible to suppress the attitude of the lens holding member such as the height position and the inclination thereof from being influenced by the detection magnet. With this, the position detecting means can surely detect 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 surely moved to a predetermined position. it can. Therefore, it is possible to provide a lens driving device capable of coping with speeding up of autofocus.

According to this, the magnetic detection member is not disposed at the position where the magnetic fields of the first magnetized portion and the second magnetized portion cancel each other. Therefore, the magnetic field from the first magnetized portion located closer can be reliably detected by the magnetic detection member. As a result, the position of the lens holding member can be adjusted with certainty, and the lens holding member can be moved quickly and reliably to a predetermined position.

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

According to this, the driving force in the optical axis direction generated by the coil and the driving magnet can be applied to the lens holding member in good balance. Further, the distance between the detection magnet and each driving magnet can be made approximately the same and longer. Therefore, the influence of the magnetic field from the detection magnet can be reduced evenly for the respective drive magnets, and the posture of the lens holding member is not affected.

Further, the lens driving device of the present invention is characterized in that the detection magnet is composed of one magnet having the first magnetized portion and the second magnetized portion.

According to this, compared with the case where it is configured with two magnets, the detection magnet can be easily arranged and can be manufactured at low cost.

Further, in the lens driving device of the present invention, 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. It is characterized by being.

According to this, as compared with the case where it is configured by one magnet, a large magnetic force from the detection magnet is easily obtained, and the accuracy of detecting the position of the lens holding member can be improved.

Further, the lens driving device of the present invention is characterized in that the magnetic detection member is arranged laterally of the lens holding member.

According to this, the height dimension can be reduced.

Further, in the lens driving device of the present invention, the housing includes a case having a side wall portion, and a base member integrated with the case and provided with a power supply terminal for energizing the coil. And a plate-shaped member having a plurality of external terminals electrically mounted on the magnetic detection member and electrically connected to the magnetic detection member, wherein the external terminals are exposed to the outside of the case. It is arranged in the housing along the inner surface of the portion, and the power supply terminal and the external terminal are arranged in a line.

According to this, the magnetic detection member can be easily arranged on the side of the lens holding member. Further, since the power supply terminal and the external terminal are arranged in a line, the layout of the mounting board and the like on which the lens driving device is mounted becomes easy.

The lens driving device of the present invention can cancel out the interference of the magnetic fields of the detection magnet and the driving magnet, and can suppress the influence of the magnetic field from the detection magnet on the driving magnet. Therefore, it is possible to suppress the attitude of the lens holding member such as the height position and the inclination thereof from being influenced by the detection magnet. With this, the position detecting means can surely detect 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 surely moved to a predetermined position. it can. Therefore, it is possible to provide a lens driving device capable of coping with speeding up of autofocus.

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 diagrams illustrating the lens driving device according to 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. It is a figure explaining the lens drive device of 1st Embodiment of this invention, FIG.4(a) is a perspective view which abbreviate|omitted the case shown in FIG. 2, FIG.4(b) is FIG.4(a). FIG. 4 is a perspective view in which the frame-shaped member and the position detection means shown in FIG. 6A and 6B are views for explaining the lens driving device of the first embodiment of the present invention, FIG. 5A is a side view of FIG. 4A viewed from the X1 side, and FIG. 4(b) is a side view seen from the X1 side. 6A and 6B are diagrams illustrating the lens driving device according to the first embodiment of the present invention, FIG. 6A is a bottom view of FIG. 2 seen from the Z2 side, and FIG. FIG. 4B is a bottom view in which the base member shown in FIG. It is a figure explaining the lens drive device of 1st Embodiment of this invention, Comprising: It is sectional drawing in the VII-VII line shown in FIG.3(a). 8A and 8B are views illustrating 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 a perspective view which the coil was wound around the lens holding member shown to a). FIG. 9A is a diagram illustrating a biasing 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. 10A and 10B are views illustrating a base member of the lens driving device according to the first embodiment of the present invention, FIG. 10A is a perspective view of the base member, and FIG. FIG. 7 is a perspective view showing a state in which a lower leaf spring is placed on the base member of FIG. It is a figure explaining the drive mechanism of the lens drive device concerning 1st Embodiment of this invention, Comprising: It is a bottom view which abbreviate|omitted the lower side leaf spring and lens holding member shown in FIG.6(b). 12A and 12B are views for explaining the position detecting means of the lens driving device according to the first embodiment of the present invention, FIG. 12A is a perspective view of the position detecting means, and FIG. It is a perspective view of the position detection means seen from the Y1 side shown in 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 expanded side view of P part 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 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 of the lens driving device 101 shown in FIG. 2 in which the case 14 that is the fixed-side member R4 is omitted, and FIG. 4B is a frame-shaped member 44 shown in FIG. 4A. It is a perspective view in which the position detecting means K7 is further omitted. 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 the line VII-VII shown in FIG. It should be noted that FIGS. 5 and 7 show an initial state in which no current is applied to the coil 35.

The lens driving device 101 according to the first embodiment of the present invention has an appearance of a rectangular parallelepiped shape as shown in FIGS. 2, 3 and 6(a), and as shown in FIGS. A cylindrical lens holding member 2 capable of holding (not shown), an urging member 3 for movably supporting the lens holding member 2 in the optical axis direction KD, and a housing 4 for housing the lens holding member 2. The fixed member R4, the drive mechanism M5 for moving the lens holding member 2 along the optical axis direction KD (Z direction shown in FIG. 2), and the position detecting means for detecting the position of the lens holding member 2 in the optical axis direction KD. And K7.

Further, 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. 4(b) and 5(b), 5 and FIG. 6B, the lens holding member 2 is configured to include two lower leaf springs 3C and 3E fixed to the lower portion of the lens holding member 2 and supporting 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. It has a frame-shaped member 44 disposed in the. Further, the housing 4 of the fixed-side member R4 is formed in a rectangular parallelepiped shape, and has a case 14 having a box-shaped outer shape as shown in FIG. 1 and a case 14 integrated with the case 14 as shown in FIG. And a base member 8 according to the present invention.

Further, the drive mechanism M5 includes an annular coil 35 wound around the lens holding member 2 and two drive magnets 55 arranged to face the coil 35, as shown in FIGS. 4 and 7. ing.

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

Then, 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 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 moves the lens holding member 2 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. 8A and 8B are views 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.

The lens holding member 2 of the lens driving device 101 is made of liquid crystal polymer (LCP, Liquid Crystal Polymer) or the like, which is one of synthetic resins, and is formed into a cylindrical shape as shown in FIG. A cylindrical portion 12 having a peripheral surface and a rectangular outer peripheral surface (the upper end side is circular), and an eaves portion 22 protruding radially outward from the upper end side (Z1 side shown in FIG. 4) of the outer peripheral surface of the cylindrical portion 12. A flange portion 32 that is provided so as to face the eaves portion 22 and projects radially outward from the outer peripheral surface of the lower end (Z2 side shown in FIG. 4) of the tubular portion 12. The lens holding member 2 is arranged above the base member 8 (Z1 direction shown in FIG. 4) as shown in FIG.

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

In addition, as shown in FIG. 8, pedestal portions 12d are formed on the outer peripheral surface of the tubular portion 12 above the eaves portion 22 so as to face each other. Then, when the lens driving device 101 is assembled, as shown in FIG. 4B, two pedestal portions 12d (lens holding member 2) facing each other (X direction shown in FIG. 4B) are formed. The upper leaf spring 3A (first portion 13 described later) of the biasing member 3 is fixed with an adhesive.

Further, on the bottom surface of the lens holding member 2 on the side of the flange portion 32, as shown in FIG. 6B, a cylindrical shape protruding downward (Z2 direction shown in FIG. 8 in front of the paper surface in FIG. 6B). convex portion 12t is provided at four positions (two convex portions 12t ₁ and two convex portions 12t _2). Then, when the lens driving device 101 is assembled, as shown in FIG. 6B, the two protruding portions 12t ₁ are engaged with the lower leaf spring 3C (the third portion 33 described later), and The two protruding portions 12t ₂ engage 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. 6B, prismatic entwined portions 12k protruding downward are provided at two positions. Each of the coil end portions 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. 6B, the solder HD to 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 biasing member 3 of the lens driving device 101 will be described. 9A and 9B are views for explaining the urging member 3, FIG. 9A is a top view of the upper leaf spring 3A shown in FIG. 1 seen from the Z1 side, and FIG. 9B is a diagram. FIG. 3 is a top view of the lower leaf spring 3C and the lower leaf spring 3E shown in FIG. 1 viewed from the Z1 side.

The urging member 3 of the lens driving device 101 is made of a metal plate whose main material is copper alloy. As shown in FIG. 4B, the urging member 3 is formed from the inner peripheral surface of the cylindrical portion 12 of the lens holding member 2. Also has an opening with a large diameter and is provided between the lens holding member 2 and the frame-shaped member 44, and the upper leaf spring 3A and the two provided between the lens holding member 2 and the base member 8. It is composed of a lower leaf spring 3C and a lower leaf spring 3E. 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 so that the lens holding member 2 is moved in the optical axis direction KD (see FIG. 2). The biasing member 3 supports the lens holding member 2 in the air so that it can move in the Z direction). 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. 6B, a power feeding member for the coil 35. It also has the function of.

First, as shown in FIG. 9A, the upper leaf spring 3A of the urging member 3 has a substantially rectangular outer shape and is fixed to the lens holding member 2 (a first embodiment of the present invention. First portion 13 at two locations) and four second portions 23 located on the outer peripheral side of the first portion 13 and fixed to the fixed-side 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 from the first portion 13 and connected, and four second portions 23 at four locations. And a cross section 73 that connects the two. 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 73 forms a rectangular shape.

Then, when the upper leaf spring 3A is incorporated in the lens driving device 101, the first portion 13 is placed on the pedestal portion 12d of the lens holding member 2 as shown in FIG. 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 driving magnet 55 (see FIGS. 4B and 5 ), and together with the frame member 44, the driving member 55 is driven. It is sandwiched between the magnet 55 and the case 14. The drive 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 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 3A is configured to have a substantially line-symmetrical shape as shown in FIG. 9A, and two uniform positions of the first portion 13 with respect to the lens holding member 2 are provided. (See FIG. 4), and is fixed to the fixed side member R4 (the case 14 and the frame-shaped member 44) at four equal positions of the second portion 23 (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 biasing member 3 have a substantially rectangular outer shape and a semicircular inner shape. 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 four Two elastic arm portions 53c and 53e located between the portions 43, a first chain portion 83 connecting the third portions 33 at two locations, and a first chain portion connecting each of the fourth portions 43 at two locations. And two chain portions 93.

Further, as shown in FIG. 9B, circular through holes 33k are formed in the third portions 33 of the lower leaf spring 3C and the lower leaf spring 3E, respectively. Further, 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 a rectangular through hole 43s and a through hole 43t are formed at 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. 6B, the two protruding portions 12t ₁ (12t) of the lens holding member 2 are provided. Is inserted through the through hole 33k (see FIG. 9B) of the lower leaf spring 3C (see FIG. 9B), and the two protruding portions 12t ₂ (12t) of the lens holding member 2 are attached to the lower leaf spring 3E. Through the through hole 33k (see FIG. 9B). 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 18t (see FIG. 1) provided on the upper surface of the base member 8 described later is inserted into the through holes 43m (see FIG. 9B) of the lower leaf spring 3C and the lower leaf spring 3E. Are fitted together. As a result, the other side of the lower leaf spring 3C and the lower leaf spring 3E is positioned on the base member 8 and fixed to the base member 8.

In this way, the lower leaf spring 3C and the lower leaf spring 3E are configured to have substantially line-symmetrical shapes as shown in FIG. 9B, and the third portion 33 of the lens holding member 2 is formed. The connection is made at four uniform positions, and at the same time, at four uniform positions of the fourth portion 43 with respect to the base member 8. 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 member R4 of the lens driving device 101 will be described. 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 has a function of fixing a part of the biasing member 3 that supports the lens holding member 2 so that the lens holding member 2 moves along the optical axis direction KD, 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 holds the second portion 23 of the upper leaf spring 3A between the drive magnet 55 and the case 14, which is fixed to the case 14. 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 are fixed are configured. ing. In the first embodiment of the present invention, the frame-shaped member 44 and the driving magnet 55 sandwich the two portions of the second portion 23 of the upper leaf spring 3A to fix the other side of the upper leaf spring 3A. 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 member R4 will be described. The case 14 is manufactured by cutting, drawing, etc. using a metal plate made of a non-magnetic metal material. The case 14 has a box-shaped outer shape as shown in FIG. It has a substantially rectangular shape (in plan view) as shown. The case 14 includes a flat plate-shaped side wall portion 14A, a flat plate-shaped upper plate portion 14B continuously provided with an upper end of the side wall portion 14A (Z1 side shown in FIG. 1), and a portion connecting the side wall portion 14A. And a corner portion 14C located therein, and a substantially circular opening 14k is formed in the upper plate portion 14B.

As shown in FIG. 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-shaped member 44, and a drive mechanism M5 (coil 35). And the drive magnet 55) so as to accommodate these members and engage with the base member 8 disposed below (Z2 direction shown in FIG. 2) to be 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 formed of a synthetic resin such as polybutylene terephthalate (PBT) and having a rectangular opening 44k at the center, as shown in FIG. The frame-shaped member 44 includes a first extending portion 44A that is a pair of sides facing each other, a second extending portion 44B that is another pair of sides intersecting with the pair of sides, and The first extension portion 44A and the second extension portion 44B are connected to a corner side portion 44C.

When the frame-shaped member 44 is incorporated in the lens driving device 101, as shown in FIGS. 4(a) and 5(a), the frame-shaped member 44 is disposed above the upper leaf spring 3A, and as shown in FIG. As shown, the corner side portions 44C of the frame-shaped member 44 and the driving magnet 55 arranged diagonally sandwich the second portion 23 of the upper leaf spring 3A. Further, as shown in FIG. 4A, the first extending portion 44A of the frame-shaped 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-shaped member 44 is formed. The middle portion of the extending portion 44B comes 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 made by injection molding using the same synthetic resin material as the lens holding member 2 such as liquid crystal polymer (LCP). As shown in FIG. 10A, the outer shape is a rectangular plate shape. And is formed in an annular shape having a circular opening 8k in its central portion. Further, on the upper surface of the base member 8, as shown in FIG. 10A, four projecting portions 18t (two projecting portions 18t ₁ and two projecting portions 18t ₂ ) projecting upward are provided. It is provided in the four corners. Then, as described above, as shown in FIG. 10B, the protruding portion 18t is inserted into the through holes 43m (see FIG. 9B) of the lower leaf spring 3C and the lower leaf spring 3E by fitting. Are combined. At this time, the protruding portion 18t of the base member 8 is heat-crimped to more securely fix the lower leaf spring 3C and the lower leaf spring 3E to the base member 8.

Further, as shown in FIG. 10A, the base member 8 has three terminals T9 (a power supply terminal T9C, a power supply terminal T9C) made of a metal plate using 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 element (not shown) is mounted, and electric power can be supplied from the electrode land of the mounting board and the electrodes can be supplied. It is designed to be grounded to 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 power feeding terminal T9C and the power feeding terminal T9E by soldering, welding or the like.

Although not shown in detail in the base member 8, a connecting 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 used in the same manner as the three terminals T9. The connection member 59 is partly exposed at the four corners of the case 14, as shown in FIG. 3A. 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, the joints between the connecting member 59 of the base member 8 and the four corners of the case 14 are welded at four locations to form a case. 14 is fixed to the base member 8. At least a part of the connecting member 59 is formed integrally with the ground terminal T9G. Therefore, 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 for explaining 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-shaped 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. It is configured to include the annular coil 35 that is formed and two drive magnets 55 that are arranged to face the coil 35.

First, the coil 35 of the driving mechanism M5 is made of a metal wire material having an outer periphery coated with an insulating 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. 8B, the coil 35 is disposed between the eaves portion 22 and the flange portion 32, and is supported and fixed from the inner side to the rectangular outer peripheral surface. Note that the coil 35 has a shape in which a metal wire is wound and bundled, but in FIGS. 1, 4 and 8B, etc., the coil 35 is simplified and shown with a flat surface.

Further, in the coil 35, both ends of the wound metal wire can be electrically conducted, and as described above, as shown in FIG. 6B, each of the coil ends has two lower ends. The side leaf springs 3C and the lower leaf springs 3E are soldered and electrically connected.

Next, as the driving magnet 55 of the driving mechanism M5, for example, two samarium-cobalt magnets are used, and as shown in FIG. 11, a pair of corners located diagonally of the housing 4 (case 14) with the optical axis interposed therebetween. One is arranged in each of the portions 14</b>C and is arranged so as to face the coil 35. Further, the driving magnet 55 has a trapezoidal cross-sectional shape in order to efficiently arrange the driving magnet 55 at the corner 14C, and the upper bottom faces the corner 14C and the lower bottom is the coil. 35, and the leg has a shape along the side wall portion 14A. The legs of the drive magnet 55 are pressed against the side wall portion 14A and are fixed to the case 14 that is the fixed-side member R4 with an adhesive. The drive 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.

As described above, since the lens holding member 2 and the coil 35, the case 14 and the driving magnet 55 are respectively arranged, the lens driving device 101 is configured such that a current is supplied from the power source to the coil 35. Due to the electromagnetic force generated, a thrust acts on the coil 35 in accordance with the direction in which the current flows, and 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 one by one at the pair of corner portions 14C diagonally located on the housing 4 with the optical axis interposed therebetween, the coil 35 and the driving coil 55 are driven. The driving force in the optical axis direction KD generated by the magnet 55 can be applied to the lens holding member 2 in good balance.

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

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

First, the detection magnet 75 of the position detection means K7 is formed in a rectangular parallelepiped shape by using, for example, one samarium-cobalt magnet, and is arranged on the collar portion 32 of the lens holding member 2 as shown in FIG. 4(a). It is fixed with an adhesive. As a result, the detection magnet 75 moves along with the movement of the lens holding member 2.

Further, as shown in FIGS. 12 and 13, the detection magnet 75 has a first magnetized portion MG1 magnetized to magnetic poles different from each other in the optical axis direction KD and a magnetized portion opposite to the first magnetized portion MG1. The second magnetized portion MG2 magnetized so as to form 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 closer to the magnetic detection member 77 is magnetized so that the upper side is the S pole and the lower side is the N pole, and the second magnetized section 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 poles are opposite to those of the first magnetized portion MG1. As a result, the interference of the magnetic fields of the detection magnet 75 and the driving magnet 55 can be canceled out, and the influence of the magnetic field from the detection magnet 75 on the driving magnet 55 can be suppressed. This means that when a magnet magnetized with a set of N and S poles is used, the magnetic fields of the detection magnet 75 and the driving magnet 55 interfere with each other, and due to this interference, the lens in the initial state It is possible to solve the problems that the height position of the holding member 2 shifts and the posture of the lens holding member 2 tilts.

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

In addition, in the first embodiment of the present invention, since the detection magnet 75 is configured by one magnet, the detection magnet 75 can be easily arranged as compared with the case where it is configured by two magnets. , Can be manufactured cheaply.

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

The magnetic detection member 77 is fixed to the plate-shaped member 79 so as to face the detection magnet 75 by being soldered to four conductive members 79d of a plate-shaped member 79 described later. As a result, the magnetic detection member 77 is arranged laterally of the lens holding member 2, and the height dimension can be reduced as compared with the case where the magnetic detection member 77 is arranged above or below the lens holding member 2. The magnetic sensitivity direction of the Hall element is the Y direction shown in FIG.

Then, the magnetic detection member 77 can detect the change in the magnetic field due to the movement of the detection magnet 75 fixed to the lens holding member 2 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 can adjust the actual position of the lens holding member 2. As a result, the lens holding member 2 whose position has been adjusted and clarified 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, since the magnetic detection member 77 is arranged at a position closer to the first magnetized portion MG1 than the second magnetized portion MG2, the magnetic fields of the first magnetized portion MG1 and the second magnetized portion MG2 cancel each other. The magnetic detection member 77 is not provided at the matching position. Therefore, the magnetic field from the first magnetized portion MG1 can be reliably detected by the magnetic detection member 77. As a result, the position of the lens holding member 2 can be adjusted with certainty, and the lens holding member 2 can be quickly and reliably moved to a predetermined position.

Next, as shown in FIG. 12B, the plate-shaped member 79 of the position detecting means K7 has four external terminals 79c formed of a conductive metal member and a conductive member formed integrally with the external terminals 79c. It is configured to include a conductive member 79d that forms a pattern and a base member 79f that exposes the external terminal 79c and burys the conductive member 79d. A magnetic detection member 77 is mounted on the plate member 79, and the four external terminals 79c of the plate member 79 are electrically connected to the magnetic detection member 77 via the conductive member 79d.

Further, when the lens driving device 101 is assembled, the plate member 79 is arranged 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 terminals 79c are exposed to the outside of the case 14. Then, the four external terminals 79c are electrically connected to the terminals T9 of the base member 8 and the electrode lands of the mounting board on which the image pickup device (not shown) is mounted. Thereby, the magnetic detection member 77 can be easily arranged on the side of the lens holding member 2. Further, since the three terminals T9 (the power feeding terminal T9C, the power feeding terminal T9E, and the ground terminal T9G) and the external terminal 79c are arranged in a line (see FIG. 6A), the mounting in which the lens driving device 101 is mounted 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 that form the housing 4 with an adhesive.

In the position detecting means K7 configured as described above, the magnetic flux generated from the detecting magnet 75 changes due to the movement of the detecting magnet 75 with the movement of the lens holding member 2, and the change in the magnetic flux is detected by the magnetic field. 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, respectively. 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.

When an electric current is applied to the coil 35 from the power supply terminal T9C side from this initial state, 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, when the current is applied to the coil 35, the electromagnetic force generated in the coil 35 causes the lens driving device 101 to urge one of the upper leaf spring 3A, the lower leaf spring 3C, and the lower leaf spring 3E. On the contrary, it becomes possible to move the lens body (not shown) integrally with the lens holding member 2 along the optical axis direction KD (Z direction shown in FIG. 2). The current flowing through the coil 35 is controlled based on the position 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 collectively described below.

Since the lens driving device 101 of the first embodiment of the present invention has the position detecting means K7 for detecting 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. Therefore, the lens holding member 2 whose position is clearly adjusted by adjustment can be quickly moved to a predetermined position such as a position where an image is focused. Therefore, it is possible to shorten the time until the position of the lens holding member 2 is determined. Moreover, even if the detecting magnet 75 and the magnetic detecting member 77 having a simple structure are used as the position detecting means K7, the detecting magnet 75 has the first magnetized portion MG1 and the first magnetized portion MG1 whose magnetic poles in the optical axis direction KD are opposite to each other. Since it has two magnetized portions MG2, it is possible to cancel out the interference of the magnetic fields of the detection magnet 75 and the driving magnet 55, and to suppress the influence of the magnetic field from the detection magnet 75 which the driving magnet 55 receives. You can Therefore, it is possible to suppress the attitude of the lens holding member 2 such as the height position and the inclination thereof from being influenced by the detection magnet 75. With these, 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 moves, the lens holding member 2 can be quickly and quickly moved to a predetermined position. It can be moved reliably. Therefore, it is possible to provide the lens driving device 101 capable of coping with the speedup of autofocus.

Further, since the magnetic detection member 77 is arranged at a position closer to the first magnetized portion MG1 than the second magnetized portion MG2, the magnetic fields of the first magnetized portion MG1 and the second magnetized portion MG2 cancel each other. The magnetic detection member 77 is not provided at the matching position. Therefore, the magnetic field from the first magnetized portion MG1 can be reliably detected by the magnetic detection member 77. As a result, the position of the lens holding member 2 can be adjusted with certainty, 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 in the pair of corner portions 14C located diagonally of the housing 4 with the optical axis interposed therebetween, the optical axis direction KD created by the coil 35 and the driving magnet 55 The driving force to the lens holding member 2 can be exerted in good balance. Further, since the detection magnet 75 is arranged 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 driving magnet 55 is about the same. It can be longer. Therefore, the influence of the magnetic field from the detection magnet 75 can be reduced evenly for each drive magnet 55, and the posture of the lens holding member 2 can be less affected. ..

Further, since the detection magnet 75 is composed of one magnet, the detection magnet 75 can be easily arranged and can be manufactured at a low cost, as compared with the case where it is composed of two magnets.

Further, by arranging the magnetic detection member 77 on the side of the lens holding member 2, the height dimension can be reduced as compared with the case where it is arranged on the upper side or the lower side of the lens holding member 2. it can.

Further, by disposing the plate-shaped member 79 on which the magnetic detection member 77 is mounted in the housing 4, the magnetic detection member 77 can be easily arranged on the side of the lens holding member 2. Further, since the power supply terminal T9C and 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 board or the like on which the lens driving device 101 is mounted is easy.

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, one magnet is used as the detection magnet 75 to have a simple structure, but the present invention is not limited 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. This makes it easier to obtain a large magnetic force from the detection magnet 75, as compared with the case where a single magnet is used, and the accuracy of detecting 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 as the S pole, the lower side is magnetized as the N pole, the upper side of the second magnetized portion MG2 is magnetized as the N pole, and the lower side is magnetized as the S pole. Although it is configured to be magnetized, the present invention is not limited to this, and it is sufficient 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 as N pole, the lower side thereof may be magnetized as S pole, and the upper side of the second magnetized portion MG2 may be magnetized as S pole and the lower side thereof may be magnetized as N pole. ..

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

<Modification 4>
In the above-described first embodiment, the Hall element is used as the magnetic detection member 77, but the present invention is not limited to this. For example, a magnetoresistive effect element whose resistance changes due to a change in magnetism may be used.

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

2 lens holding member 3 biasing member 3A upper leaf spring 3C, 3E lower leaf spring R4 fixed side 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 Magnetization unit MG2 Second magnetization unit 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 (6)

A cylindrical lens holding member capable of holding the 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 that houses the lens holding member,
An annular coil wound around the lens holding member,
A plurality of drive magnets arranged facing the coil and fixed to the fixed member,
In a lens driving device equipped with
A position detecting means for detecting the position of the lens holding member in the optical axis direction,
The drive magnet is magnetized to have different magnetic poles on the inside facing the coil and the outside opposite to the inside,
The position detection means is configured to include a detection magnet fixed to the lens holding member, and a magnetic detection member provided to face the detection magnet,
The detection magnet has a first magnetized portion magnetized to magnetic poles different from each other in the optical axis direction, and a second magnetized portion magnetized to have a magnetic pole opposite to the first magnetized portion. And have,
The first magnetized portion and the second magnetized portion are provided adjacent to each other ,
The lens driving device , wherein the magnetic detection member is arranged at a position 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 with the optical axis interposed therebetween.
The lens driving device according to claim 1 , wherein the detection magnet is arranged on the lens holding member at a position corresponding to another corner different from the pair of corners of the housing. .. The lens drive device according to claim 1 or 2 , wherein the detection magnet is composed of one magnet having the first magnetized portion and the second magnetized portion. The detecting magnet includes a first magnet having a first magnetized portion, and a second magnet having a second magnetization portion, claim 1, characterized in that it consists of two magnets or The lens driving device according to claim 2 . The lens drive device according to any one of claims 1 to 4 , wherein the magnetic detection member is arranged laterally of the lens holding member. The casing includes a case having a side wall portion, and a base member integrated with the case and provided with a power supply terminal for energizing the coil,
The side wall portion in a state in which the plate-shaped member having the magnetic detection member mounted thereon and having a plurality of external terminals electrically connected to the magnetic detection member exposes the external terminals to the outside of the case. 6. The lens driving device according to claim 5 , wherein the lens driving device is arranged along the inner surface of the housing, and the power supply terminal and the external terminal are arranged in a line.