WO2010058638A1

WO2010058638A1 - Lens drive device and camera module having lens drive module mounted therein

Info

Publication number: WO2010058638A1
Application number: PCT/JP2009/064484
Authority: WO
Inventors: 三生中島; 博司山下; 裕麻青井; 哲太田; 裕之奥田
Original assignee: 三洋電機株式会社
Priority date: 2008-11-21
Filing date: 2009-08-19
Publication date: 2010-05-27
Also published as: JP2012027045A

Abstract

A small-sized lens drive device, wherein play of magnets relative to a holder is suppressed. A method of manufacturing the lens drive device is also provided. A lens drive device is provided with a holder (10) for holding a lens and capable of moving in the direction of the optical axis of the lens, magnets (20) fixed separated from each other in the direction around the periphery of the holder (10), and coils mounted facing the magnets (20) in the radial direction perpendicular to the direction of the optical axis and generating magnetic fields. The holders (10) and the magnets (20) are integrally formed by injection molding. Each magnet (20) is provided with corners (21) composed of curved surfaces and sloped surfaces for interconnecting adjacent surfaces of the surfaces forming the magnet (20). Among the corners (21) of each magnet (20), corners (21a) for connection between an outer surface (20a) of the magnet (20), the outer surface (20a) radially facing the coil, and side surfaces (20b, 20c) of the magnet (20), the side surfaces (20b, 20c) being adjacent to the outer surface (20a), are radially covered by holders (10).

Description

Lens driving device and camera module equipped with the lens driving device

The present invention holds a lens and is movable in the optical axis direction of the lens;
The present invention relates to a lens driving device including a plurality of magnets that are spaced apart and fixed in a circumferential direction that is a peripheral direction of the optical axis direction of the lens of the holder.

In recent years, a camera mounted on a mobile phone has been increased in the number of pixels and has become an essential function. Therefore, in order to perform autofocus of the camera, a lens driving device that moves the lens in the direction of the optical axis of the lens (hereinafter referred to as “optical axis direction”) is used in the camera. On the other hand, with the reduction in thickness and size of mobile phones, there is an increasing demand for reducing the space provided to the lens driving device. In order to respond to this requirement, as a structure for driving the lens of the lens driving device, for example, a voice coil type structure as in Patent Document 1 is adopted. This voice coil type structure is generally known to be able to reduce the size of the lens driving device because the structure can be simplified as compared with a structure using a stepping motor.

In the above voice coil structure, the coil is mounted on the holder side that holds the lens, the magnet is mounted on the base side, and the holder is moved in the lens optical axis direction by the electromagnetic driving force generated by applying current to the coil. Has moved to. Further, the holder is supported by a spring member, and the spring member is shared for power supply to the coil so that the wiring is not drawn from the holder.

According to this configuration, since the wiring for supplying power to the coil is not pulled out from the holder, it is possible to suppress the problem that the wiring is damaged due to unnecessary vibration and tension applied to the wiring during lens driving. . However, on the other hand, in this configuration, the structure of the spring member is complicated,
There arises a problem that the yield at the time of manufacturing the lens driving device tends to decrease.

As a configuration for solving such a problem, a configuration in which a magnet is mounted on the holder side and a coil is mounted on the base side can be employed. In this configuration, since it is not necessary to wire the holder, it is possible to suppress the breakage of the wire when driving the lens and simplify the configuration of the lens driving device by removing the spring member.
JP 2004-280031 A

However, in this configuration, when an external impact is applied to the lens driving device, a large impact is applied to the movable holder. Therefore, when the bonding strength between the holder and the magnet is low, the magnet may rattle against the holder.

Therefore, the present invention has been made in view of the above problems, and its object is to
In a small lens driving device, it is to provide a lens driving device in which a magnet is prevented from rattling with respect to a holder and a camera module equipped with the lens driving device.

In order to achieve the above object, the invention described in claim 1 is characterized in that a lens is held and a holder is movable in the direction of the optical axis of the lens, and the lens is surrounded from the radial direction and spaced apart from each other. In a lens driving device including a plurality of magnets fixed to a holder and a coil that generates a magnetic field while being opposed to the magnet in the radial direction, the magnet includes a surface on which the magnet is configured. A corner portion formed by a curved surface and an inclined surface connecting the adjacent surfaces to each other, and the holder and the plurality of magnets are integrally formed by injection molding, and the corner portion of the magnet A first corner portion connecting the first side surface of the magnet facing the coil and the magnet in the radial direction and the surface of the magnet adjacent to the first side surface is covered from the radial direction by the holder. The the gist.

According to the present invention, the manufacturing process of the lens driving device can be simplified by injection molding the holder and the plurality of magnets as compared with the case where the magnets are fixed to the holder with an adhesive. The bonding strength between the holder and the magnet can be improved. Therefore, it can suppress that a magnet rattles with respect to a holder. Moreover, the magnet is prevented from moving from the holder to the coil side by covering the first corner portion connecting the first side surface of the magnet facing the coil and the surface of the adjacent magnet from the radial direction with the holder. Can do. As a result, it is possible to suppress the occurrence of rattling of the magnet with respect to the holder.

The invention according to claim 2 is characterized in that, in the lens driving device according to claim 1, the holder is provided with a cover portion covering an end surface of the magnet in the direction of the optical axis.

According to this invention, since the joint area between the magnet and the holder can be increased by the cover portion, the joint strength between the magnet and the holder can be improved. Therefore, generation | occurrence | production of the shakiness of the magnet with respect to a holder can be suppressed. In addition, since the holder covers the end surface in the direction of the optical axis of the magnet, the magnet can be prevented from moving in the optical axis direction with respect to the holder. Therefore, the occurrence of rattling in the optical axis direction of the magnet with respect to the holder can be suppressed.

The invention described in claim 3 is the lens driving device according to claim 2, wherein the corner portion connecting the first side surface and the end surface of the magnet is covered from the radial direction by the cover portion. To do.

According to this invention, a cover part can suppress more reliably that a magnet moves to a radial direction with respect to a holder by covering the corner | angular part which connects a 1st side surface and an end surface from a radial direction. . Therefore, both the shakiness in the direction of the optical axis of the magnet relative to the holder and the shakiness in the radial direction can be suppressed by the cover portion.

According to a fourth aspect of the present invention, in the lens driving device according to any one of the first to third aspects, the first corner portion of the magnet is formed larger than the other corner portions. The gist.

According to the present invention, since the first corner portion of the magnet is formed larger than the other corner portions, the size of the holder covering the first corner portion is increased, so that the magnet is moved in the radial direction with respect to the holder. It can be surely suppressed.

According to a fifth aspect of the present invention, in the lens driving device according to any one of the first to third aspects, the magnet includes a second side surface opposite to the first side surface in the radial direction. The second corner that connects the end faces is formed to be larger than the other corners, and the second corner is covered from the direction of the optical axis by the holder.

According to this invention, the movement of the magnet in the direction of the optical axis of the magnet relative to the holder can be suppressed by covering the second corner portion connecting the second side surface and the end surface of the magnet. Further, since the second corner portion suppresses the rattling of the magnet with respect to the holder, the first corner portion can be formed small. Therefore, it is possible to secure the area of the first side surface that is the surface facing the coil, and it is possible to suppress a decrease in magnetic force between the coil and the magnet.

The invention described in claim 6 is a camera module, and is characterized in that the lens driving device according to any one of claims 1 to 5 is mounted.

According to the present invention, the lens driving device can be suitably mounted on the camera module.

According to the present invention, in a small lens driving device, it is possible to provide a lens driving device in which a magnet is prevented from rattling with respect to a holder, and a camera module equipped with this lens driving device.

(First embodiment)
A first embodiment in which the lens driving device according to the present invention is embodied as a lens driving device used for autofocus of a camera mounted on a mobile phone will be described with reference to FIGS.

Hereinafter, the direction along the optical axis of the lens is referred to as “optical axis direction”, the radial direction of the lens is referred to as “radial direction”, and the direction surrounding the lens from the radial direction is referred to as “circumferential direction”. Further, in the optical axis direction of the lens driving device 1, the base 30 side is defined as “lower side”, and the case 40 side is defined as “upper side”. In the radial direction of the lens driving device 1, the side toward the optical axis is defined as “inside”, and the side away from the optical axis is defined as “outside”.

First, the overall configuration of the lens driving device 1 will be described with reference to FIG.

As shown in FIG. 1, the lens driving device 1 is provided with a movable body 1a that can move in the optical axis direction, a driving force applied to the moving body 1a, and a fixed that is fixed to a device on which the lens driving device 1 is mounted. It is comprised by the body 1b. The lens driving device 1 performs autofocusing of the camera by moving the lens in the optical axis direction as the moving body 1a moves in the optical axis direction. In addition, the lens driving device 1 according to the present embodiment has about 8. in plan view in the optical axis direction.
It is formed in a 5 mm square, and the height of the lens driving device 1 in the optical axis direction is about 3 mm.

The movable body 1a includes a lens 1 and a holder 1 that holds a lens holder RH that holds the lens.
0 and a plurality of magnets 20 fixed to the holder 10. In addition, the four magnets 20 of this embodiment are being fixed to the holder 10 via the fixed distance in the circumferential direction mutually. The magnet 20 is a neodymium magnet (Ne-Fe-B). In particular, the magnet 20 of the present embodiment uses a neodymium sintered magnet formed in a plate shape.

The fixed body 1b is applied with a current and a base 30 and a case 40 that constitute an outer frame of the lens driving device 1, a shaft 50 that is fixed to the base 30 and guides the movement of the holder 10 in the optical axis direction. Thus, the coil 60 is formed to form a magnetic field. Further, on the outer side in the radial direction of the coil 60, a rectangular plate-like magnetic plate 70 formed of a magnetic steel plate.
Is fixed to the base 30.

The base 30 is provided with a base portion 31 constituting the lower surface of the outer frame of the lens driving device 1 and a support column portion 32 extending from the base portion 31 along the optical axis direction. The base 31 is formed in a square shape in a plan view in the optical axis direction. And the support | pillar part 32 is provided in the four corners of the base 31, respectively. An opening 33 that is a circular through hole is formed at the center of the base 31. In addition, two magnetic plates 70 are fixed at two positions on the periphery of the base 30. Specifically, the magnetic plate 70 is fixed at the center position of each side constituting the periphery of the base 30.

The case 40 constitutes an outer side surface and an upper surface of the lens driving device 1. The case 40 is attached to the base 30 so as to surround the outer side of the coil 60 in the radial direction. In addition, two through holes 41 into which the shaft 50 is inserted and an opening 42 through which the movable body 1a can be inserted are provided on the upper surface of the case 40.

The shaft 50 is fixed to the base 31 of the base 30 and is inserted into the through hole 41 of the case 40 so as to be held along the optical axis direction. This shaft 5
0 is inserted into the holder 10. The holder 10 can move along the shaft 50 by making it slidable with respect to the shaft 50. That is, the moving body 1a is guided by the shaft 50 and moves in the optical axis direction.

The coil 60 is wound around the four support portions 32 of the base 30. And
The coil 60 includes a first coil 61 wound in a predetermined direction and a second coil 62 wound in a direction opposite to the winding direction of the first coil 61. When a current is applied to the first coil 61 and the second coil 62, magnetic fields are generated around the first coil 61 and the second coil 62, respectively. The magnetic field and the magnet 20 generate a force that moves the moving body 1a in the optical axis direction.

Next, the driving operation of the lens driving device 1 will be described with reference to FIG.

In FIG. 2A, the moving body 1a is located at the home position. Specifically, the lower surface of the holder 10 of the moving body 1 a is in contact with the upper surface of the base portion 31 of the base 30. Mobile body 1a
Is in the home position, no current is applied to the coil 60.

When a current is applied to the coil 60, that is, the first coil 61 and the second coil 62.
When a current having a direction shown in FIG. 2 (b) is applied, the moving body 1a moves to the position shown in FIG. 2 (b). Specifically, when a current is applied to the first coil 61 and the second coil 62, a magnetic field is generated around each of the first coil 61 and the second coil 62. A magnetic circuit is formed by the magnetic field and the magnet 20, and a force for moving the moving body 1a upward in the optical axis direction is generated. Then, the moving body 1a moves from the home position shown in FIG. 2 (a) upward in the optical axis direction to the position shown in FIG. 2 (b).

On the other hand, when a current in the direction opposite to the direction shown in FIG. 2B is applied to each of the first coil 61 and the second coil 62, a magnetic circuit is formed by these magnetic fields and the magnet 20, and the moving body A force is generated to move 1a downward in the optical axis direction. That is, the moving body 1a is shown in FIG.
Move from the position b) toward the home position. Here, the coil 60 in FIG.
As for the marks attached to, a black dot mark on the circle indicates a direction toward the drawing reference person, and a cross mark on the circle indicates a direction away from the drawing reference person.

As described above, the lens is moved to the on-focus position while moving the moving body 1a upward and downward in the optical axis direction. At this time, the moving body 1 a slides with respect to the two shafts 50 due to the magnetic force generated between the two magnetic plates 70 and the magnets 20 facing the magnetic plates 70 in the radial direction. For this reason, even when the moving body 1a is moved in the vertical direction, a frictional resistance acts on the gravity. Further, even if the current application to the coil 60 is interrupted after the lens is moved to the on-focus position, the moving body 1a is maintained at the on-focus position by the magnetic force between the magnet 20 and the magnetic plate 70. Is done.

Next, the detailed structure of the moving body 1a will be described with reference to FIGS.

First, the shape of the moving body 1a will be described with reference to FIGS.

As shown in FIG. 3A, the holder 10 and the magnet 20 are integrally molded as a substantially octagonal prism shape by injection molding of a resin material. In other words, the holder 10 and the magnet 20 are
It is formed by insert molding. Of the side surfaces of each magnet 20, the coil 60 is used.
The outer side surface 20a which is the opposing surface in the radial direction forms a continuous surface with the side surface 10a of the holder 10. Further, the holder 10 has an opening hole 1 for holding the lens holder RH.
1 is provided.

Moreover, as shown in FIG.3 (b), the corner | angular part 21 which connects each side surface of the magnet 20 is each formed in the curved surface shape. In addition, the corner portion 21a that connects the outer surface 20a of the magnet 20 and the side surfaces 20b and 20c extending radially inward from the circumferential edge of the outer surface 20a is formed on the holder 1.
0 is covered from the outside in the radial direction. With this structure, the holder 10 suppresses the magnet 20 from moving radially outward with respect to the holder 10.

As shown in FIG. 3C, the holder 10 is provided with a cover 12 so as to cover the lower end surface 20e, which is the lower surface of the magnet 20 in the optical axis direction, from the lower side in the optical axis direction. It has been. The cover portion 12 constitutes the lower end surface 10b of the holder 10 and is continuous with the side surface 10a. That is, the side surface 12a of the cover part 12 constitutes the side surface 10a.

Here, as shown in FIG. 4A, the holder 10 has a cylindrical portion 13 that covers the inner surface 20d of the magnet 20 from the inside in the radial direction, and projects from the cylindrical portion 13 to the inside in the radial direction. A fixing portion 14 for fixing the holder RH is provided. A threaded portion 14 a is provided on the inner peripheral surface that is the radially inner surface of the fixed portion 14. The lens holder RH is fixed by screwing with the screw portion 14a.

Further, as shown in FIG. 4B, the cover portion 12 includes an outer surface 20 a and a lower end surface 2 of the magnet 20.
It is provided so that the corner | angular part 21b which connects 0e may be covered from the outer side of radial direction. The side surface 12 a of the cover portion 12 forms a surface that is continuous with the outer surface 20 a of the magnet 20. With this structure, the holder 10 suppresses the magnet 20 from moving radially outward with respect to the holder 10.

Moreover, as shown in FIG.4 (c), the upper end surface 10c which is an upper surface of the optical axis direction of the holder 10 is shown.
Forms a continuous surface with the upper end surface 20f which is the upper surface of the magnet 20 in the optical axis direction.
The holder 10 has a corner 21c that connects the inner surface 20d of the magnet 20 and the upper end surface 20f.
Is provided so as to cover from above in the optical axis direction. With this structure, the holder 10 suppresses the magnet 20 from moving upward in the optical axis direction with respect to the holder 10.

Next, a mold for integrally molding the holder 10 and the magnet 20 will be described with reference to FIG.

As shown in FIG. 5, the mold 80 for integrally molding the holder 10 and the magnet 20 is arranged by injecting a resin material into the mold 80 after placing the magnet 20 in the mold 80. And the magnet 20 is shape | molded. The mold 80 is composed of a first mold 81 to a third mold 83. The first mold 81 is provided with the upper end surface 20f of the magnet 20 and the holder 10
The upper end surface 10c is formed. The second mold 82 is in contact with the outer surface 20 a of the magnet 20 and forms the side surface 10 a of the holder 10 and the cover portion 12. The third mold 83 can be inserted into the second mold 82 and forms the cylindrical portion 13 and the fixing portion 14 of the holder 10.

Next, the configuration of the camera module when the lens driving device 1 of the present embodiment is mounted on a camera will be described with reference to FIG.

As shown in FIG. 6, the filter 2 and the image sensor 3 are arranged on the base 30 side of the lens driving device 1. That is, the filter 2 and the image sensor 3 are disposed below the base 30 in the optical axis direction. In the base 30, the Hall element 4 is disposed as a position detection element. Based on the signal from the Hall element 4, the position of the moving body 1a is detected.

During the focusing operation, a CPU (Central Processing Unit) 5 controls the driver 6 to move the moving body 1a from the home position to a preset position in the optical axis direction. At this time, a position detection signal from the Hall element 4 is input to the CPU 5. At the same time, CP
U5 processes the signal input from the image sensor 3 to obtain the contrast value of the captured image. Then, the position of the moving body 1a having the best contrast value is acquired as the on-focus position.

Thereafter, the CPU 5 drives the moving body 1a toward the on-focus position. At that time, C
The PU 5 monitors the signal from the hall element 4 and drives the moving body 1a until the signal from the hall element 4 is in a state corresponding to the on-focus position. Thereby, the moving body 1a is positioned at the on-focus position.

According to the lens driving device 1 of the present embodiment, the following effects can be obtained.

(1) In the present embodiment, the holder 10 and the magnet 20 are integrally formed by injection molding, and the corner portion 21a that connects the outer surface 20a and the side surfaces 20b and 20c of the magnet 20 has a diameter by the holder 10. It is the structure covered from the outer side of a direction. According to this structure, compared with the case where the magnet 20 is fixed to the holder 10 with an adhesive, the bonding strength between the holder 10 and the magnet 20 can be improved. When the magnet 20 is fixed to the holder 10 with an adhesive, the step of inserting the magnet 20 into the holder 10 and the holder 10 and the magnet 2 in order to produce the moving body 1a.
Two steps are required, that is, a step of applying an adhesive to at least one of 0, but in this embodiment, the moving body 1a can be manufactured only by the step of injection molding the holder 10 and the magnet 20. The manufacturing process of the lens driving device 1 can be simplified.

Moreover, since the corner | angular part 21a of the magnet 20 is covered from the radial direction outer side by the holder 10, it can suppress that the magnet 20 moves to the radial direction outer side with respect to the holder 10. FIG. In particular,
Due to the coil 60 and the magnetic plate 70, the magnet 20 is always subjected to a force to move radially outward relative to the holder 10. At that point, the holder 10 is connected to the corner 21a of the magnet 20.
By covering the holder 10, the holder 10 works as a resistance against the above force. As a result, the occurrence of rattling in the radial direction of the magnet 20 with respect to the holder 10 can be suppressed.

(2) In the present embodiment, the outer side surface 20a of the magnet 20 and the side surface 10a of the holder 10 are configured to be formed as one continuous surface. Here, when the outer surface 20a of the magnet 20 and the side surface 10a of the holder 10 are not formed by a continuous surface, that is, when the radial position of the outer surface 20a is different from the radial position of the side surface 10a. The outer surface 20a of the magnet 20 and the holder 10
The shape of the inner side surface of the second mold 82 for molding the side surface 10a of the magnet 10 must be a stepped shape that forms two surfaces, a surface corresponding to the outer side surface 20a of the magnet 20 and a surface corresponding to the side surface 10a of the holder 10. I must. For this reason, the shape of the second mold 82 becomes complicated, and the cost of the mold 80 increases.

In that respect, in the present embodiment, the outer surface 20a of the magnet 20 and the side surface 10a of the holder 10 are used.
Since it is a structure formed by one continuous surface, in the injection molding, the outer surface 20a of the magnet 20 and the side surface 10a of the holder 10 can be molded on one surface of the mold. Therefore, the shape of the inner side surface 82a of the second mold 82 of the mold 80 for molding the outer side surface 20a of the magnet 20 and the side surface 10a of the holder 10 can be simplified. Specifically, the shape of the inner side surface 82a of the second mold 82 that molds the outer side surface 20a of the magnet 20 and the side surface 10a of the holder 10 only needs to be formed as an octagon in plan view. That is, each surface constituting the octagon can be formed by a flat surface having no step shape. As a result, the cost of the second mold 82 can be reduced, and the cost of the mold 80 can be reduced.

(3) In this embodiment, the holder 10 has a cover portion 12 that covers the lower end surface 20 e of the magnet 20.
Is provided. According to this configuration, the magnet 20 is held by the cover 10 with the holder 10.
Against the lower side in the optical axis direction. Therefore, the holder 1
Occurrence of rattling in the optical axis direction of the magnet 20 with respect to 0 can be suppressed.

(4) In this embodiment, the cover part 12 is the structure which covers the corner | angular part 21b which connects the outer side surface 20a and the lower end surface 20e of the magnet 20 from the outer side of radial direction. According to this configuration, the cover portion 1
2, it is possible to suppress the magnet 20 from moving radially outward with respect to the holder 10. Therefore, the occurrence of rattling in the radial direction of the magnet 20 with respect to the holder 10 can be more reliably suppressed. Moreover, when the bonding area between the magnet 20 and the holder 10 increases, the bonding strength between the magnet 20 and the holder 10 can be improved. Therefore, the occurrence of rattling in the optical axis direction of the magnet 20 with respect to the holder 10 can be more reliably suppressed.
As described above, the cover portion 12 can suppress the occurrence of rattling in the radial direction and the optical axis direction of the magnet 20 with respect to the holder 10.

In the present embodiment, the side surface 12a of the cover portion 12 constitutes the side surface 10a of the holder 10, that is, the side surface 12a of the cover portion 12 and the outer surface 20a of the magnet 20 form a continuous surface. Even when the cover portion 12 is provided, the shape of the inner side surface 82a of the second mold 82 can be simplified.

(5) In this embodiment, the corner | angular part 21 which connects the inner surface 20d of the magnet 20, and the upper end surface 20f.
In this configuration, c is covered by the holder 10. With this configuration, the upward movement of the magnet 20 in the optical axis direction can be suppressed. In particular, since the magnet 20 is also covered by the cover portion 12 from the lower side in the optical axis direction, the magnet 20 is sandwiched and joined from both sides in the optical axis direction by the holder 10. Therefore, the movement of the magnet 20 relative to the holder 10 in the optical axis direction can be more reliably suppressed.

(6) In the present embodiment, the upper end surface 10c of the holder 10 and the upper end surface 20f of the magnet 20 are formed as a continuous surface. Here, when the upper end surface 10c of the holder 10 and the upper end surface 20f of the magnet 20 are not formed by a continuous surface, that is, the position of the upper end surface 10c of the holder 10 in the optical axis direction and the upper end surface of the magnet 20 When the position of 20 f in the optical axis direction is different, the shape of the upper surface 81 a of the first mold 81 that forms the upper end surface 20 f of the magnet 20 and the upper end surface 10 c of the holder 10 is changed to the upper end surface 20 f of the magnet 20. Corresponding surface and upper end surface 1 of holder 10
It must be a step shape that forms two of the surfaces corresponding to 0c. Therefore, the first mold 8
Since the shape of 1 becomes complicated, the cost of the metal mold | die 80 will increase.

In that respect, in this embodiment, the upper end surface 10c of the holder 10 and the upper end surface 20 of the magnet 20 are used.
In the injection molding, the upper end surface 10c of the holder 10 and the upper end surface 20f of the magnet 20 can be molded on one surface of the mold. In particular,
The upper surface 81a of the first mold 81 can be configured only by a uniform plane. Therefore, since the shape of the first mold 81 can be simplified, the cost of the first mold 81 can be reduced. As a result, the cost of the mold 80 can be reduced.

In addition, since the position of the upper end surface 10c of the holder 10 and the upper end surface 20f of the magnet 20 in the optical axis direction is the same, the cover 12 is moved as compared with the case where the cover portion 12 is also provided on the upper end surface 20f side of the magnet 20. The body 1a can be downsized in the optical axis direction, and the lens driving device 1 can be downsized.

(7) In this embodiment, the lens driving device 1 is mounted on a camera module of a mobile phone. Here, especially in mobile devices such as mobile phones, due to the fall of these devices,
An external impact may be applied to the lens driving device 1. In this case, the external impact is greatly applied to the movable body 1a movable in the optical axis direction. As a result, rattling of the magnet 20 with respect to the holder 10 may occur due to a force applied to the joint portion between the holder 10 and the magnet 20. In this regard, in the present embodiment, the corners 21a to 21c of the magnet 20 are replaced with the holder 10.
The cover 10 and the cover portion 12 cover the lower end surface 20e of the magnet 20 so that the bonding strength between the holder 10 and the magnet 20 is improved. As a result, it is possible to suppress the occurrence of rattling of the magnet 20 with respect to the holder 10 due to an external impact. Therefore, it is preferable to mount the lens driving device 1 of the present embodiment on the portable device.

(Second Embodiment)
With reference to FIG. 7, a second embodiment in which the lens driving device according to the present invention is embodied as a lens driving device used for autofocus of a camera mounted on a mobile phone will be described. In addition, since this embodiment is a configuration in which a part of the shape of the magnet 20 and the holder 10 is changed as compared with the first embodiment, the same components are denoted by the same reference numerals, and description thereof is omitted. To do.

As shown in FIG. 7A, the corner portion 21 a that connects the outer surface 20 a and the side surfaces 20 b and 20 c of the magnet 20 is formed larger than the other corner portions 21. And as shown in FIG.7 (b), the corner | angular part 21a goes to the inner side of radial direction from the outer side surface 20a to the side surfaces 20b and 2b.
It is formed by a flat inclined surface facing 0c. And the holder 10 has this corner | angular part 21
It is formed so as to cover a from the outside in the radial direction. Thereby, the holder 10 is attached to the magnet 20.
Is restrained from moving outward in the radial direction with respect to the holder 10.

According to this embodiment, in addition to the effects (1) to (7) of the first embodiment, the following effects can be obtained.

(8) In the present embodiment, the corner portion 21 a of the magnet 20 is configured to be larger than the other corner portions 21 of the magnet 20. Here, in the magnet 20, a radially outward force is always applied to the holder 10 by the coil 60 and the magnetic plate 70. That is, the magnet 20 is connected to the holder 10.
Is constantly moving outward in the radial direction. In this respect, in the present embodiment, by forming the corner portion 21a of the magnet 20 to be large, it becomes possible to increase the size of the holder 10 that covers the corner portion 21a from the outside in the radial direction. It is possible to more reliably suppress the outward movement of 20 in the radial direction.

In particular, in the present embodiment, since the magnet 20 uses a neodymium magnet,
Magnetic force is larger than ferrite magnet. That is, the force with which the magnet 20 moves to the outer side in the radial direction with respect to the holder 10 is strong. In this regard, in the present embodiment, since the holder 10 is large enough to cover the magnet 20 from the radial direction, the magnet 2 for the holder 10 is used even if a neodymium magnet is used.
The movement in the radial direction of 0 can be reliably suppressed.

(Third embodiment)
With reference to FIG. 8, a third embodiment in which the lens driving device according to the present invention is embodied as a lens driving device used for autofocus of a camera mounted on a mobile phone will be described. In addition, since this embodiment is a configuration in which a part of the shape of the magnet 20 and the holder 10 is changed as compared with the first embodiment, the same components are denoted by the same reference numerals, and description thereof is omitted. To do.

As shown in FIG. 8A, the corner 2 connecting the inner surface 20d of the magnet 20 and the upper end surface 20f.
1c is formed larger than the other corner | angular part 21. As shown in FIG. And as shown in FIG.
The corner 21c is formed by a flat inclined surface that is inclined outward in the radial direction as it goes upward in the optical axis direction. And the holder 10 is formed so that this corner | angular part 21c may be covered from the upper side of an optical axis direction. Thereby, the holder 10 suppresses the magnet 20 from moving upward in the optical axis direction with respect to the holder 10.

(9) In this embodiment, the corners 21c of the magnet 20 are formed larger than the other corners 21,
The corner portion 21 c is covered from the upper side in the optical axis direction by the holder 10. According to this configuration, the upward movement of the magnet 20 relative to the holder 10 in the optical axis direction can be suppressed. In addition, since the bonding strength between the magnet 20 and the holder 10 increases as the corner portion 21c of the magnet 20 is formed larger, it is possible to prevent the corner portion 21a from becoming larger than necessary.
Therefore, it is possible to suppress a decrease in the area of the outer side surface 20a of the magnet 20 that is the surface facing the coil 60 due to the corner 21a. Therefore, a decrease in magnetic force between the outer surface 20a and the coil 60 can be suppressed.

(Other embodiments)
The present invention is not limited to the embodiment exemplified above, and can be modified as follows.

-In the lens drive device 1 of 2nd Embodiment, although the magnitude | size of the corner | angular part 21a was formed larger than the other corner | angular part 21, the shape of the corner | angular part 21a of the magnet 20 is not limited to this. . For example, as shown in FIG. 9, the structure which forms the magnet 20 in trapezoid shape may be sufficient. That is, the side surfaces 20b and 20c of the magnet 20 may have a tapered shape in which the width of the magnet 20 is narrowed toward the outside in the radial direction. According to this configuration, the effects (1) to (7) of the first embodiment can be obtained. In particular, since the holder 10 is large enough to cover the side surfaces 20b and 20c of the magnet 20 from the outside in the radial direction, the occurrence of rattling of the magnet 20 with respect to the holder 10 can be reliably suppressed.

In the lens driving device 1 of the first to third embodiments, the lens driving device 1 is applied to a camera module mounted on a mobile phone, but the scope of application of the present invention is not limited to this. For example, the present invention may be applied to a camera module mounted on another portable device.

In the lens driving device 1 of the first to third embodiments, the upper end surface 20f of the magnet 20 and the holder 1
Although the upper end surface 10c of 0 is formed as one continuous surface, the shape of the moving body 1a is not limited to this. For example, the upper end surface 10 c of the holder 10 may have a shape that covers the upper end surface 20 f of the magnet 20. That is, the shape which provides a cover part also in the upper end surface 20f side of the magnet 20 may be sufficient. According to this configuration, the bonding strength between the holder 10 and the magnet 20 can be improved. However, since the length of the moving body 1a in the optical axis direction becomes longer by the provision of the cover portion, it is preferable when the length of the moving body 1a in the optical axis direction has a margin.

In the lens driving device 1 of the first to third embodiments, the moving body 1a is the lower end surface 2 of the magnet 20
Although 0e was the shape covered with the cover part 12, the shape of the moving body 1a is not limited to this. For example, as shown in FIG. 10, the moving body 1a may have a shape in which the cover portion 12 is not provided. According to this configuration, the length of the moving body 1a in the optical axis direction can be shortened. Therefore, it is possible to reduce the size of the lens driving device 1 in the optical axis direction. In this case, the holder 10 includes the inner surface 20d and the upper end surface 20f of the magnet 20 and the inner surface 20.
It is desirable that the corner portion 21 connecting the d and the lower end surface 20e is covered from the inside in the radial direction. With this structure, it is possible to reduce the size of the moving body 1a in the optical axis direction and to suppress the occurrence of rattling of the magnet 20 with respect to the holder 10.

In the lens driving device 1 of the first to third embodiments, the corner portion 21 of the magnet 20 is formed.
The shape of the magnet 20 of the present invention is not limited to this. For example, the corners of the magnet 20 may be formed at the stage of forming the magnet 20 with a mold. And you may utilize the corner | angular part in the said case. Thereby, compared with a structure in which the corner portion 21 is not covered with the holder 10, the bonding area between the holder 10 and the magnet 20 can be increased.
The bonding strength between the magnet 20 and the magnet 20 can be improved. In addition, the magnet 2 for the holder 10
The movement of 0 in the radial direction can be suppressed, and rattling of the magnet 20 in the radial direction with respect to the holder 10 can be suppressed. Thereby, even if it omits giving special processing for formation of the corner | angular part 21 of the magnet 20, generation | occurrence | production of rattling of the magnet 20 with respect to the holder 10 can be suppressed. Therefore, the cost of the magnet 20 can be reduced.

Further, for example, at the stage of delivery from a magnet manufacturer, there are cases where corners are formed in the magnet 20 to prevent the corners of the magnet 20 from being chipped. In that case as well, corners formed at the stage of delivery from such a magnet manufacturer may be used. Thereby, the improvement of the joining strength of the holder 10 and the magnet 20 and generation | occurrence | production of the shakiness of the magnet 20 with respect to the holder 10 can be suppressed similarly to the above. As a result, since it is not necessary to perform special processing to form the corner portion 21 in the magnet 20, the cost of the magnet 20 can be reduced.

In the lens driving device 1 according to the first to second embodiments, the first mold 81 to the third mold 83 are divided into three parts as the structure of the mold 80 that integrally molds the holder 10 and the magnet 20. Although the mold is used, the configuration of the mold 80 of the present invention is not limited to this. The mold 80 may have other configurations.

The perspective view which shows the disassembled perspective structure of the lens drive device about 1st Embodiment which actualized the lens drive device which concerns on this invention. (A) Sectional drawing which shows the cross-sectional structure of the state in which a moving body is located in a home position about the lens drive device of the embodiment. (B) Sectional drawing which shows the cross-sectional structure of the state in which a moving body is located in an on-focus position about the lens drive device of the embodiment. (A) The top view which shows the planar structure which looked at the moving body from the upper side of the optical axis direction about the lens drive device of the embodiment. (B) The enlarged view to which the broken-line circle of (a) was expanded about the lens drive device of the embodiment. (C) The top view which shows the planar structure which looked at the moving body of (a) from the arrow A which is radial direction about the lens drive device of the embodiment. (A) Sectional drawing which shows the cross-section which cut | disconnected the mobile body of FIG. 3 with the plane parallel to an optical axis direction about the lens drive device of the embodiment. (B) The enlarged view to which the broken-line circle C1 of (a) was expanded about the lens drive device of the embodiment. (C) The enlarged view to which the broken-line circle C2 of (a) was expanded about the lens drive device of the embodiment. The schematic cross section which showed the cross-section of the metal mold | die which shape | molds a moving body about the lens drive device of the embodiment. The schematic diagram which shows the structure of the camera module carrying the lens drive device of the embodiment. (A) The top view which shows the planar structure which looked at the moving body of the lens drive device from the upper side of the optical axis direction about 2nd Embodiment which actualized the lens drive device which concerns on this invention. (B) The enlarged view which expanded the broken-line circle | round | yen of (a) about the same embodiment. (A) Sectional drawing which shows the cross-sectional structure which cut | disconnected the moving body of the lens driving device in the plane along the optical axis direction about 3rd Embodiment which actualized the lens driving device based on this invention. (B) The enlarged view which expanded the broken-line circle | round | yen of (a) about the same embodiment. The top view which shows the planar structure which looked at the moving body of the lens drive device from the upper side of the optical axis direction about the modification of the lens drive device which concerns on this invention. Sectional drawing which showed the cross-section which cut | disconnected the holder of the lens drive device by the plane along the optical axis direction about the other modification of the lens drive device which concerns on this invention.

RH ... lens holder, 1 ... lens driving device, 1a ... moving body, 1b ... fixed body, 2 ... filter, 3 ... image sensor, 4 ... Hall element (position detection element), 5 ... CPU, 6 ... driver, 10 ... Holder, 10a ... side face, 10b ... lower end face, 10c ... upper end face, 11 ... opening, 20
... magnet, 20a ... side surface (first side surface), 20b ... side surface, 20c ... side surface, 20d ... inside surface (second side surface), 20e ... lower end surface (end surface), 20f ... upper end surface (end surface), 21 ... corner portion 21a ... Corner (first corner), 21b ... Corner, 21c ... Corner (second corner), 30 ... Base, 31 ... Base, 32 ... Column, 40 ... Case, 41 ... Through-hole, 42 ... opening, 50 ... shaft, 60 ...
Coil 61 ... first coil 62 ... second coil 70 ... magnetic plate 80 ... mold 81 ... first
Mold, 82 ... second mold, 83 ... third mold.

Claims

A holder that holds the lens and is movable in the direction of the optical axis of the lens, a plurality of magnets that surround the lens from the radial direction and that are spaced apart from each other and are fixed to the holder, and the magnet in the radial direction And a lens driving device including a coil that generates a magnetic field.
The magnet is provided with a corner portion formed by a curved surface and an inclined surface connecting the adjacent surfaces to each other in the surface constituting the magnet,
The holder and the plurality of magnets are integrally formed by injection molding,
Of the corner portions of the magnet, the first corner portion connecting the first side surface of the magnet facing the coil in the radial direction and the surface of the magnet adjacent to the first side surface is formed by the holder with the diameter. A lens driving device characterized by being covered from a direction.
The lens driving device according to claim 1,
The lens driving device, wherein the holder is provided with a cover portion that covers an end surface of the magnet in the direction of the optical axis.
The lens driving device according to claim 2,
The lens driving device, wherein a corner portion connecting the first side surface and the end surface of the magnet is covered in a radial direction by a cover portion.
The lens driving device according to any one of claims 1 to 3,
The first corner portion of the magnet is formed to be larger than the other corner portions.
The lens driving device according to any one of claims 1 to 3,
In the magnet, a second corner portion that connects the second side surface opposite to the first side surface in the radial direction and the end surface is formed to be larger than other corner portions,
The second corner is covered from the direction of the optical axis by the holder.
A camera module comprising the lens driving device according to any one of claims 1 to 5.