TW201939115A - Lens drive device, camera module, and camera mounting device - Google Patents

Abstract

Provided are a lens drive device, a camera module, and a camera mounting device, with which a reduction in size and weight can be achieved and reliability can be increased. The lens drive device comprises: a shake correction fixed unit; a shake correction movable unit that is capable of swinging within a plane orthogonal to an optical axis; a shake correction support unit that supports the shake correction movable unit in a state in which the shake correction movable unit is separated in the optical axis direction from the shake correction fixed unit; and a drive source that swings the shake correction movable unit. One of the shake correction fixed unit and the shake correction movable unit has a projection part that projects in the optical axis direction. The other of the shake correction fixed unit and the shake correction movable unit has a flat part that abuts the projection part. The projection part and the flat part slide relative to each other during shake correction. The projection part is elastically displaceable in the optical axis direction.

Description

Lens driving device, camera module, and camera mounting device

The present invention relates to a lens driving device for camera shake correction, a camera module, and a camera mounting device.

Generally, a small camera module is mounted on a portable terminal such as a smartphone. A lens driving device having an autofocus function and a shake correction function is applied to this camera module. The autofocus function (hereinafter referred to as "AF function", AF: Auto Focus) automatically focuses when shooting a subject The above-mentioned shake correction function (hereinafter referred to as "OIS function", OIS: Optical Image Stabilization) is to optically correct shake (vibration) generated during shooting to reduce image disturbance (for example, Patent Document 1, Patent Document 2) .

A lens driving device having an autofocus function and a shake correction function includes a drive unit for autofocus (hereinafter referred to as "AF drive unit") for moving the lens portion toward the optical axis direction, and a drive unit for shake correction (hereinafter (Referred to as a "drive unit for OIS") for swinging the lens unit in a plane orthogonal to the optical axis direction. In Patent Documents 1 and 2, a voice coil motor (VCM) is applied to the AF drive unit and the OIS drive unit.

The OIS drive unit includes a shake correction movable portion (hereinafter referred to as "OIS movable portion") that shakes in a plane orthogonal to the optical axis direction during shake correction. The OIS movable section is supported by a shake correction fixing section (hereinafter referred to as "OIS fixing section") via a shake correction support section (hereinafter referred to as "OIS support section"). In the lens driving device disclosed in Patent Document 1, the OIS support portion is constituted by a suspension wire extending in the optical axis direction, and the OIS movable portion is spaced apart from the OIS fixed portion in the optical axis direction. maintain.
[Prior Art Literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2013-210550
[Patent Document 2] Japanese Patent Laid-Open No. 2012-177753

[Problems to be Solved by the Invention]

In recent years, in order to reduce the size (thinness) and weight of camera-equipped devices such as smartphones, further reductions in size and weight of lens driving devices are required. Along with this, in the lens driving device of the wire support system disclosed in Patent Document 1, thinning of the suspension wire and thinning of a member for fixing the suspension wire (hereinafter referred to as "wire fixing member") are required. Walled.

However, when the thinning of the suspension line and the thinning of the wire fixing member are promoted, since the rigidity of the member is reduced, the OIS movable portion is caused by a change in the posture of the lens driving device or a lens at the focus Such as displacement in a plane orthogonal to the optical axis, or tilting with respect to the optical axis, and there is a concern that the performance of the AF function or the OIS function is reduced.

An object of the present invention is to provide a lens driving device, a camera module, and a camera mounting device that can be downsized and lightened, and can improve reliability.
[Means for solving problems]

The lens driving device of the present invention includes:
A shake correction fixing portion; a shake correction movable portion that can swing in a plane orthogonal to the optical axis; a shake correction support portion that separates the shake correction movable portion from the shake correction fixing portion in the optical axis direction And a driving source that swings the shake correction movable portion, wherein one of the shake correction fixed portion and the shake correction movable portion has a protruding portion protruding toward the optical axis direction,
The other of the shake correction fixing portion and the shake correction movable portion has a flat portion that abuts the protruding portion,
The protruding portion and the flat portion slide relative to each other during shake correction,
The protruding portion is elastically displaceable toward the optical axis direction.

The camera module of the present invention is characterized by comprising:
The lens driving device;
A lens unit is mounted on the shake correction movable unit; and an imaging unit is configured to capture a subject image formed by the lens unit.

The camera mounting device of the present invention is a camera mounting device as an information device or a transportation device, and includes:
The camera module; and an image processing unit that processes image information obtained by the camera module.
[Effect of the invention]

According to the present invention, it is possible to reduce the size and weight of a lens driving device, a camera module, and a camera-mounted device, and improve reliability.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

1 (A) and 1 (B) are diagrams showing a smartphone M (camera-mounted device) equipped with a camera module A according to an embodiment of the present invention. FIG. 1 (A) is a front view of the smart phone M, and FIG. 1 (B) is a rear view of the smart phone M.

The smartphone M is equipped with, for example, a camera module A as a back camera OC. The camera module A has an AF function and an OIS function, and can automatically perform focusing when shooting a subject, and can optically correct a shake (vibration) generated during shooting to capture an image without image blur.

FIG. 2 is an external perspective view of the camera module A. FIG. FIG. 3 is an exploded perspective view of the camera module A. FIG. As shown in FIGS. 2 and 3, in the present embodiment, description is made using an orthogonal coordinate system (X, Y, Z). In the figures described later, a common orthogonal coordinate system (X, Y, Z) is also used.

When actually shooting with the smartphone M, the camera module A is mounted with the X direction as the up and down direction (or left and right direction), the Y direction as the left and right direction (or up and down direction), and the Z direction as the front and back direction. That is, the Z direction is the optical axis direction, the upper side in the figure is the light receiving side in the optical axis direction, and the lower side is the imaging side in the optical axis direction. The X and Y directions orthogonal to the Z axis are referred to as "optical axis orthogonal directions", and the XY plane is referred to as "optical axis orthogonal surfaces".

As shown in FIGS. 2 and 3, the camera module A includes: a lens driving device 1 that implements the AF function and the OIS function; the lens section 2 is formed by accommodating a lens in a cylindrical lens barrel; Section (not shown) for capturing a subject image formed by the lens section 2 and a cover 3 for covering the entirety. In addition, in FIG. 3, the lens section 2 is omitted.

The cover 3 is a rectangular box body having a rectangular shape when viewed from above in the direction of the optical axis. In this embodiment, the cover 3 has a square shape in a plan view. The cover 3 has a substantially circular opening 3a on a surface on the light-receiving side in the optical axis direction (hereinafter referred to as "upper surface"). The lens portion 2 faces outward from the opening 3a. The cover 3 is fixed to the base 21 (see FIG. 9) of the OIS fixing portion 20 of the lens driving device 1, for example.

The imaging unit (not shown) is disposed on the imaging side in the optical axis direction of the lens driving device 1. The imaging unit (not shown) includes, for example, an image sensor substrate and an imaging element mounted on the image sensor substrate. The imaging element is configured by, for example, a charge coupled device (CCD) image sensor, a complementary metal oxide semiconductor (CMOS) image sensor, or the like. The imaging element captures a subject image formed by the lens unit 2. The lens driving device 1 is mounted on an image sensor substrate (not shown), and is mechanically and electrically connected. The control unit that performs the drive control of the lens driving device 1 may be provided on the image sensor substrate, or may be provided on a camera-mounted device (a smartphone M in this embodiment) on which the camera module A is mounted.

4 and 5 are exploded perspective views of the lens driving device 1. FIG. 4 is an upper perspective view, and FIG. 5 is a lower perspective view.

As shown in FIGS. 4 and 5, in this embodiment, the lens driving device 1 includes an OIS movable section 10, an OIS fixed section 20, an OIS support section 30, and the like. In this embodiment, the driving source of the lens driving device 1 is a voice coil motor (VCM).

The OIS movable unit 10 includes a driving magnet 122 (OIS magnet, see FIG. 6) constituting a voice coil motor for the OIS, and is a portion that swings in the orthogonal plane of the optical axis during shake correction. The OIS fixed portion 20 includes an OIS coil 221 (see FIG. 9) constituting an OIS voice coil motor, and is a portion that supports the OIS movable portion 10 via the OIS support portion 30. That is, the driving unit for OIS of the lens driving device 1 is a moving magnet type. The OIS movable section 10 includes an AF driving section including an AF movable section 11 and an AF fixed section 12 (see FIG. 6).

The OIS movable section 10 is disposed at a distance from the OIS fixed section 20 on the light-receiving side in the optical axis direction, and is connected to the OIS fixed section 20 via the OIS support section 30. In the present embodiment, the OIS support portion 30 is composed of four suspension lines extending in the optical axis direction (hereinafter referred to as "hanging lines 30"). In addition, the OIS support portion may be constituted by a member other than the suspension wire 30.

One end (the light-receiving-side end portion and the upper end) of the suspension line 30 is fixed to the OIS movable portion 10 (in this embodiment, the AF support portion 13 (see FIG. 6)), and the other end (the optical-axis-direction imaging side end) Parts) are fixed to the OIS fixing part 20 (in this embodiment, the base 21 (see FIG. 9)). The OIS movable portion 10 is supported swingably in the plane orthogonal to the optical axis by a suspension line 30. Two of the four suspension wires 30 are used as a feeding path to the AF coil 112.

FIG. 6 is an exploded perspective view of the OIS movable section 10. FIG. 7 is a cross-sectional view of the OIS movable section 10. FIG. 8 is a bottom view of the OIS movable section 10 (a view viewed from the imaging side in the optical axis direction). FIG. 7 shows a half cross-section along the X direction or the Y direction passing through the center of the lens driving device 1.

As shown in FIGS. 6 to 8, in this embodiment, the OIS movable section 10 includes an AF movable section 11, an AF fixed section 12, an AF support section 13, an AF support section 14, and the like. The AF movable portion 11 is disposed spaced radially inward from the AF fixing portion 12, and is connected to the AF fixing portion 12 via the AF support portion 13 and the AF support portion 14.

The AF movable portion 11 includes an AF coil 112 constituting an AF voice coil motor, and is a portion that moves in the optical axis direction during focusing. The AF fixing portion 12 includes a driving magnet 122 (AF magnet) constituting an AF voice coil motor, and is a portion that supports the AF movable portion 11 via the AF support portion 13 and the AF support portion 14. That is, the AF driving section of the lens driving device 1 adopts a moving coil type.

The AF movable portion 11 is disposed at a distance from the AF fixing portion 12, and is connected to the AF fixing portion 12 via the AF support portion 13 and the AF support portion 14. In this embodiment, the AF movable portion 11 is disposed spaced apart from the AF fixed portion 12 in the radial direction. The AF support portion 13 is an upper elastic support member that supports the AF movable portion 11 with respect to the AF fixed portion 12 on the light receiving side (upper side) in the optical axis direction. In this embodiment, the AF support portion 13 is composed of two leaf springs 131 and 132 (hereinafter referred to as "upper spring 131, upper spring 132"). The AF support portion 14 is a lower elastic support member that supports the AF movable portion 11 with respect to the AF fixed portion 12 on the imaging side (lower side) in the optical axis direction. In this embodiment, the AF support portion 14 is composed of two leaf springs 141 and leaf springs 142 (hereinafter referred to as "lower spring 141, lower spring 142").

Further, in this embodiment, the OIS movable portion 10 includes a sliding portion 15 on the imaging side in the optical axis direction, and the sliding portion 15 is arranged in contact with the OIS fixed portion 20 and is performed with the OIS fixed portion 20 during shake correction Relative sliding.

As shown in FIGS. 6 to 8, in the OIS movable section 10, the AF movable section 11 includes a lens holder 111 and an AF coil 112.

The lens holder 111 is a member that holds the lens portion 2 (see FIG. 2). The lens holder 111 includes a cylindrical lens housing portion 111 a, an upper flange 111 b and a lower flange 111 c protruding from the lens housing portion 111 a toward the radially outer side. That is, the lens holder 111 has a bobbin structure. The upper flange 111b and the lower flange 111c have a substantially octagonal shape in a plan view.

An AF coil 112 is wound around a portion sandwiched between the upper flange 111b and the lower flange 111c (hereinafter referred to as a "coil winding portion"). The coil winding part (the symbol is abbreviated) has a substantially regular octagonal shape in plan view. Accordingly, when the AF coil 112 is directly wound, the load acting on the coil winding portion is uniform, and the strength of the coil winding portion is also substantially uniform with respect to the center. Therefore, deformation of the opening of the lens accommodating portion 111a can be prevented. Keep the roundness.

A lens portion is fixed to the lens housing portion 111 a by, for example, bonding (see FIG. 2). The lens accommodating portion 111a preferably has a groove (not shown) for applying an adhesive on the inner peripheral surface. In the method of attaching the lens portion 2 to the lens housing portion 111 a by screwing, there is a concern that the suspension wire 30 supporting the OIS movable portion 10 is damaged. On the other hand, in this embodiment, since the lens portion 2 is fixed to the inner peripheral surface of the lens housing portion 111 a by adhesion, the suspension wire 30 can be prevented from being damaged when the lens portion 2 is mounted. In addition, when a groove is provided on the inner peripheral surface of the lens accommodating portion 111a, an appropriate amount of the adhesive can be held by the groove, thereby increasing the bonding strength between the lens holder 111 and the lens portion 2.

The lens holder 111 has an upper spring fixing portion 111d for fixing the AF support portion 13 on the outer peripheral edge of the upper portion of the lens housing portion 111a. In this embodiment, the upper spring fixing portion 111d is provided so as to face the X direction. The lens holder 111 has a lower spring fixing portion 111 e for fixing the AF support portion 14 on a surface on the imaging side in the optical axis direction of the lower flange 111 c (hereinafter referred to as “lower surface” or “bottom surface”). In this embodiment, the lower spring fixing portion 111e is provided so as to face the Y direction.

In addition, the lens holder 111 has a winding portion (not shown) around which the end portion of the AF coil 112 is wound.

In this embodiment, the lens holder 111 is formed of a polyarylate (PAR) or a molding material containing a PAR blend obtained by mixing a plurality of resin materials containing PAR. In particular, the PAR blend is preferably a polymer alloy (PAR / PC) containing PAR and polycarbonate (PC). As a result, the welding strength is improved as compared with a conventional molding material (for example, liquid crystal polymer (LCP: liquid crystal polymer)). Therefore, even if the lens holder 111 is thinned, toughness and impact resistance can be ensured. Therefore, the external dimensions of the lens driving device 1 can be reduced, and downsizing and weight reduction can be achieved. The lens holder 111 may be formed of a liquid crystal polymer or the like.

The lens holder 111 is preferably formed by injection molding of a multi-point gate. In this case, the gate diameter is preferably 0.3 mm or more. Thereby, since the fluidity | liquidity at the time of shaping | molding becomes favorable, even when PAR or a PAR blend is used as a shaping | molding material, thin-wall shaping | molding is possible, and generation | occurrence | production of a sink mark is prevented.

PAR or a molding material containing a PAR blend has conductivity, and particularly preferably has a volume resistivity of 10 ⁹ to 10 ¹¹ Ω · cm. For example, conductivity can be easily imparted by incorporating carbon nanotubes into an existing PAR or PAR blend. In this case, appropriate conductivity can be imparted by adjusting the content of the carbon nanotube. Thereby, since the electrification of the lens holder 111 can be suppressed, generation of static electricity can be prevented.

The AF coil 112 is an air-core coil that is energized at the time of focusing, and is wound on the outer peripheral surface of the coil winding portion (the symbol is omitted) of the lens holder 111. Both ends of the AF coil 112 are wound around a winding portion (not shown) of the lens holder 111. The AF coil 112 is energized via the AF support portion 13 (upper spring 131, upper spring 132) or the AF support portion 14 (lower spring 141, lower spring 142). The energizing current of the AF coil 112 is controlled by, for example, a drive control unit provided on the image sensor substrate.

As shown in FIGS. 6 to 8, in the OIS movable section 10, the AF fixing section 12 includes a magnet holder 121 and a driving magnet 122.

The magnet holder 121 is a member that holds the driving magnet 122. In this embodiment, the magnet holder 121 is composed of a frame having a substantially octagonal shape in a plan view. The magnet holder 121 has an opening 121 a in which a portion corresponding to the lens holder 111 is cut out. In the present embodiment, the magnet holder 121 includes a magnet holding portion 121 b for holding the driving magnet 122 on the inner peripheral surface of the lens driving device 1 at positions corresponding to the four corners of the lens driving device 1. The inner surface of the magnet holding portion 121 b becomes a contact surface between the magnet holding portion 121 b and the driving magnet 122.

The adhering surface of the magnet holding portion 121b is parallel to the optical axis direction, and the imaging side end portion (the OIS fixing portion 20 side end portion in the optical axis direction) of the optical axis direction is opened. The driving magnet 122 is also used as an OIS magnet. This is because there is no intervening substance between the OIS coil 221 (see FIG. 9) arranged in the OIS fixing portion 20 and it is more magnetically preferable. That is, the driving magnet 122 is not fixed in a physically immovable manner by the shape of the magnet holding portion 121b, but is fixed only by the adhesive force of the adhesive.

The outer peripheral surface of the magnet holder 121 at positions corresponding to the four corners of the lens driving device 1 is cut out linearly. A suspension wire 30 is arranged in this part. Further, in the magnet holder 121, a portion where the suspension wire 30 is disposed may be formed in a circular arc-shaped depression toward the radially inner side. Thereby, it is not necessary to increase the external shape of the lens driving device 1, and it is possible to prevent the suspension wire 30 from interfering with the magnet holder 121 when the OIS movable portion 10 swings.

The magnet holder 121 has an upper spring fixing portion 121 d for fixing the AF support portion 13 on the upper surface. In this embodiment, the upper surface of the magnet holder 121 is provided with upper spring fixing portions 121d at positions corresponding to the four corners of the lens driving device 1. The magnet holder 121 has a lower spring fixing portion (not shown) for fixing the AF support portion 14 on the lower surface. In this embodiment, like the upper spring fixing portion 121d, lower spring fixing portions (not shown) are provided at positions corresponding to the four corners of the lens driving device 1. The corner portion of the upper spring fixing portion 121d is formed so as to be recessed toward the imaging side in the optical axis direction than the surface on which the AF support portion 13 is mounted, and a gap is formed when the AF support portion 13 is mounted.

In this embodiment, the magnet holder 121 is formed of a liquid crystal polymer. Like the lens holder 111, the magnet holder 121 may be formed of a PAR or a molding material containing a PAR blend, but is preferably formed of a liquid crystal polymer having excellent heat resistance. Since the magnet holder 121 has high heat resistance, welding of the AF support portion 13, the AF support portion 14, and the like can be easily performed. The magnet holder 121 is formed by, for example, injection molding using a mold.

In this embodiment, the driving magnet 122 is composed of four rectangular columnar magnets. The driving magnet 122 has a substantially isosceles trapezoidal shape in a plan view. Thereby, the space (the magnet holding part 121b) of the corner part of the magnet holder 121 can be effectively utilized. The driving magnet 122 is magnetized to form a magnetic field crossing the AF coil 112 in the radial direction. In this embodiment, the driving magnet 122 is magnetized such that the inner peripheral side is the N pole and the outer peripheral side is the S pole. In addition, the surface of the driving magnet 122 is covered with a metal film such as nickel (Ni) plating to improve corrosion resistance.

In the present embodiment, the driving magnet 122 is fixed to the magnet holding portion 121 b of the magnet holder 121 by adhering to it. For the adhesive, for example, an epoxy resin-based thermosetting adhesive or an ultraviolet curing adhesive is used. In the driving magnet 122, a surface (a side surface and an upper surface other than the surface exposed to the inside in this embodiment) that is in contact with the magnet holding portion 121b is a bonding surface.

The driving magnet 122 and the AF coil 112 constitute a voice coil motor for AF. In this embodiment, the driving magnet 122 serves as both an AF magnet and an OIS magnet. A yoke may be provided on the peripheral surface of the driving magnet 122.

As shown in FIGS. 6 to 8, in the OIS movable portion 10, the AF support portion 13 (upper spring 131 and upper spring 132) positions the AF movable portion 11 (lens holder 111) with respect to the AF fixed portion 12 (magnet holding portion). (Tool 121) It is elastically supported on the light receiving side in the optical axis direction. The upper spring 131 and the upper spring 132 are formed of, for example, titanium copper, nickel copper, stainless steel, or the like.

The upper spring 131 and the upper spring 132 as a whole have a rectangular shape in plan view, that is, they have the same shape as the magnet holder 121. The upper spring 131 and the upper spring 132 are disposed so as not to contact each other on the magnet holder 121. The upper spring 131 and the upper spring 132 are formed by, for example, etching a single metal plate.

The upper spring 131 and the upper spring 132 each include a lens holder fixing portion 131 a fixed to the lens holder 111, a lens holder fixing portion 132 a, a magnet holder fixing portion 131 b fixed to the magnet holder 121, and a magnet holder fixing portion. 132b, and an arm portion 131c and an arm portion 132c that connect the lens holder fixing portion 131a, the lens holder fixing portion 132a, the magnet holder fixing portion 131b, and the magnet holder fixing portion 132b. The arm portion 131c and the arm portion 132c are formed in a curved shape, and are elastically deformed when the AF movable portion 11 moves in the optical axis direction.

The upper spring 131 and the upper spring 132 have a wire connection portion 131d and a wire connection portion 132d connected to the suspension wire 30, respectively. The wire connection portion 131d and the wire connection portion 132d are connected to the magnet holder fixing portion 131b and the magnet holder fixing portion 132b via a link portion 131e and a connection portion 132e extending in a meandering manner.

In the present embodiment, the upper spring 131 and the upper spring 132 are electrically connected to a winding portion (not shown) of the lens holder 111, and current is applied to the AF coil 112 via the upper spring 131 and the upper spring 132.

As shown in FIGS. 6 to 8, in the OIS movable portion 10, the AF support portion 14 (lower spring 141, lower spring 142) positions the AF movable portion 11 (lens holder 111) with respect to the AF fixed portion 12 (magnet holding portion). 121) The elastic imaging support is provided on the imaging side in the optical axis direction. The lower spring 141 and the lower spring 142 are formed of, for example, titanium copper, nickel copper, stainless steel, or the like.

The lower spring 141 and the lower spring 142 as a whole have a rectangular shape in plan view, that is, they have the same shape as the magnet holder 121. The lower spring 141 and the lower spring 142 are disposed so as not to contact each other on the magnet holder 121. The lower spring 141 and the lower spring 142 are formed by, for example, etching a single metal plate.

The lower spring 141 and the lower spring 142 each include a lens holder fixing portion 141 a fixed to the lens holder 111, a lens holder fixing portion 142 a, a magnet holder fixing portion 141 b fixed to the magnet holder 121, and a magnet holder fixing portion. 142b, and an arm portion 141c and an arm portion 142c connecting the lens holder fixing portion 141a, the lens holder fixing portion 142a, the magnet holder fixing portion 141b, and the magnet holder fixing portion 142b. The arm portion 141c and the arm portion 142c are formed in a curved shape, and are elastically deformed when the AF movable portion 11 moves in the optical axis direction.

In this embodiment, as shown in FIGS. 6 to 8, in the OIS movable portion 10, the sliding portion 15 is composed of a holding member 151, a spacer 152, and a ball 153. The sliding portion 15 is arranged on the imaging side of the OIS movable portion 10 closest to the optical axis direction, and is in contact with the OIS fixed portion 20.

In this embodiment, the ball 153 corresponds to a protruding portion of the present invention. That is, the ball 153 protrudes toward the imaging side in the optical axis direction, and is in contact with the slide plate 23 (see the flat portion in FIG. 9) of the OIS fixing portion 20. By applying the ball 153 as a protrusion, the contact area with the sliding plate 23 is made point-to-point, and the contact area becomes small, so that the sliding property at the time of shake correction can be ensured. In addition, the ball 153 does not rotate on the slide plate 23 during shake correction, but slides.

The holding member 151 is a frame having a substantially rectangular shape in a plan view, and is continued to the spacer 152. The holding member 151 is formed of a resin material such as polycarbonate (PC).

The holding member 151 includes a thick-walled portion 151b and a thin-walled portion 151a. In this embodiment, the thin portions 151a are formed at approximately the center of the four sides of the holding member 151 in the longitudinal direction. The holding member 151 has a ball accommodating portion 151c for accommodating the balls 153 on the bottom surface side of the thin-walled portion 151a. The ball accommodating part 151c has a dimple (the symbol is omitted) corresponding to the shape of the ball 153 in the center. A ball 153 is disposed in the recess.

The thin-walled portion 151a is formed to be thinner than the thick-walled portion 151b, and is elastically deformable in the direction of the optical axis. In this embodiment, the upper surface of the thin-walled portion 151a is formed by depression, and when a force in the optical axis direction is received, it is bent toward the light-receiving side in the optical axis direction to release stress. That is, in the sliding portion 15, the holding member 151 has a beam structure that supports both ends. Further, a ball 153 which is a protruding portion is disposed on the thin-walled portion 151 a which is a beam portion. The recess on the upper surface of the thin-walled portion 151 a is preferably larger than the gap formed between the holding member 151 and the slide plate 23 (see FIG. 12 (A)).

The spacer 152 is a frame body having a substantially rectangular shape in a plan view similarly to the holding member 151, and is continued to the bottom surface of the magnet holder 121. The spacer 152 is, for example, a rigid body formed of a metal material such as a copper alloy.

The balls 153 are formed of a metal material such as zirconia. The balls 153 are arranged in the ball accommodating portion 151 c of the holding member 151. The ball 153 is interposed between the OIS movable portion 10 and the OIS fixed portion 20. When the OIS movable portion 10 and the OIS fixed portion 20 are connected by a suspension wire 30, the ball 153 is in a state of urging the OIS fixed portion 20 (the slide plate 23). Thereby, the ball 153 reliably abuts on the OIS fixing portion 20.

In this embodiment, the OIS movable portion 10 is supported by four balls 153. Thereby, the OIS movable portion 10 is held in a stable posture with respect to the OIS fixed portion 20. In addition, from the viewpoint of stabilizing the posture of the OIS movable portion 10, the number of the balls 153 (protruding portions) is preferably three or more, that is, the OIS movable portion 10 is preferably supported by three or more points.

FIG. 9 is an exploded perspective view of the OIS fixing section 20. FIG. 10 is a plan view of the OIS fixing section 20.

As shown in FIGS. 9 and 10, the OIS fixing portion 20 includes a base 21, a coil substrate 22, a slide plate 23, and the like.

The base 21 is a supporting member that supports the coil substrate 22 and the slide plate 23. The base 21 is a rectangular-shaped member in a plan view, and has a substantially circular opening 21 a in the center. A terminal metal piece 211 is embedded in the base 21. The terminal metal 211 is formed integrally with the base 21 by, for example, insert molding. In this embodiment, the terminal metal pieces 211 are exposed from the four corners of the base 21. The terminal metal piece 211 is soldered to a feed terminal (not shown) and the suspension wire 30 of the coil substrate 22, and is physically and electrically connected.

In the present embodiment, like the lens holder 111, the base 21 is formed of polyarylate (PAR) or a PAR blend (for example, PAR / PC) including a mixture of a plurality of resin materials containing PAR. Material formation. Thereby, since the welding strength is improved, even if the base 21 is thinned, toughness and impact resistance can be ensured. Therefore, the external dimensions of the lens driving device 1 can be reduced, and downsizing and downsizing can be achieved.

The base 21 is preferably formed by injection molding of a multi-point gate. In this case, the gate diameter is preferably 0.3 mm or more. Thereby, since the fluidity | liquidity at the time of shaping | molding becomes favorable, even when PAR or a PAR blend is used as a shaping | molding material, thin-wall shaping | molding is possible, and generation | occurrence | production of a sink mark is prevented.

PAR or a molding material containing a PAR blend has conductivity, and particularly preferably has a volume resistivity of 10 ⁹ to 10 ¹¹ Ω · cm. For example, conductivity can be imparted by incorporating carbon nanotubes into an existing PAR or PAR blend. In this case, appropriate conductivity can be imparted by adjusting the content of the carbon nanotube. Thereby, since the charging of the base 21 can be suppressed, generation of static electricity can be prevented.

The base 21 includes a coil substrate fixing portion 21 b where the coil substrate 22 is arranged and a slide plate fixing portion 21 c where the slide plate 23 is arranged on the periphery of the opening 21 a. The coil substrate fixing portion 21b is formed on the inner peripheral side of the slide plate fixing portion 21c more concavely than the slide plate fixing portion 21c. The upper surface of the slide plate 23 arranged on the slide plate fixing portion 21c is located more on the light-receiving side in the optical axis direction than the upper surface of the coil substrate 22 placed on the coil substrate fixing portion 21b. Thereby, a gap is reliably formed between the coil substrate 22 and the OIS movable portion 10 (the holding member 151).

As shown in FIGS. 9 and 10, in the OIS fixing portion 20, the coil substrate 22 is a rectangular substrate in a plan view similar to the base 21, and has a circular opening 22 a in the center. The coil substrate 22 is, for example, a multilayer printed wiring board in which unit layers including a conductor layer and an insulating layer (not shown) are laminated in multiple layers. For the coil substrate 22, for example, an OIS coil 221, an external terminal (not shown), and a conductor pattern (not shown) including a power line connecting the external terminal and the OIS coil 221 are integrally embedded.

In the OIS fixing portion 20, the slide plate 23 is a frame body having a substantially rectangular shape in a plan view similarly to the holding member 151. The slide plate 23 is formed of, for example, a metal material such as a copper alloy. In this embodiment, the slide plate 23 corresponds to a flat portion of the present invention. That is, the upper surface (sliding surface) of the sliding plate 23 is a flat surface and is in contact with the balls 153. The approximate center 23 a of the four sides in the longitudinal direction of the slide plate 23 forms a contact portion with the ball 153. The width of the slide plate 23 is appropriately set in accordance with the swing range of the OIS movable section 10.

In this embodiment, a low-friction treatment is applied to the sliding surface of the sliding plate 23. For the low-friction treatment, for example, a nickel plating treatment in which polytetrafluoroethylene (PTFE) is dispersed can be applied. Thereby, since the frictional force generated when the ball 153 slides on the slide plate 23 is reduced, the sliding property at the time of shake correction can be ensured.

In this embodiment, the base 21, the coil substrate 22, and the slide plate 23 are bonded by an epoxy resin material having elasticity. Since the base 21, the coil substrate 22, and the slide plate 23 are integrated by using them to improve the mechanical strength of the OIS fixing portion 20, the base 21 and the coil substrate can be secured while ensuring desired drop resistance. 22, and the sliding plate 23 is thinned.

In the lens driving device 1, one end of the suspension wire 30 is physically and electrically connected to the wire connection portion 131 d and the wire connection portion 132 d of the upper spring 131 and the upper spring 132, respectively. The other end of the suspension wire 30 is physically and electrically connected to the terminal metal piece 211 (the portion exposed from the cutout portions of the four corners) of the base 21. When the OIS movable portion 10 and the OIS fixed portion 20 are connected by a suspension wire 30, the ball 153 is in a state of urging the OIS fixed portion 20 (the sliding plate 23).

Furthermore, the lens driving device 1 may include a Z position detection unit that detects the position of the AF movable portion 11 in the optical axis direction, and / or an XY position detection unit that detects the position of the OIS movable portion 10 in the optical axis orthogonal plane. For example, the Z-position detection section and the XY-position detection section may be constituted by a position detection magnet and a Hall element, respectively. The Hall element is disposed to face the position detection magnet.

In the case of the Z-position detection section, for example, a detection magnet is disposed in the AF movable section 11 (for example, the lens holder 111), and a Hall element is disposed in the AF fixed section 12 (for example, the magnet holder 121). When the AF movable section 11 moves in the direction of the optical axis, the magnetic field caused by the position detection magnet changes. By detecting the change in the magnetic field using a Hall element, the position of the AF movable portion 11 in the optical axis direction is detected. Furthermore, a control integrated circuit (IC) with a built-in Hall element may be arranged in the AF fixing portion 12, and the energizing current of the AF coil 112 may be controlled by the control IC.

The XY position detection unit includes two sets of position detection magnets and Hall elements. As the position detection magnet, a driving magnet 122 can be used. In the case of the XY position detection section, for example, a detection magnet is disposed in the OIS movable section 10 (for example, the magnet holder 121), and a Hall element is disposed in the OIS fixing section 20 (for example, the coil substrate 22). When the OIS movable section 10 moves in the plane orthogonal to the optical axis, the magnetic field caused by the position detection magnet changes. By detecting the change in the magnetic field using two Hall elements, the position of the OIS movable portion 10 in the plane orthogonal to the optical axis is detected.

The closed loop control based on the Hall output improves response performance, so it is possible to speed up AF operation or OIS operation.

When shake correction is performed in the lens driving device 1, current is applied to the OIS coil 221. Specifically, the OIS driving unit controls the OIS based on a detection signal from a shake detection unit (not shown, for example, a gyro sensor) so as to cancel the shake of the camera module A. The energizing current of the coil 221.

When the OIS coil 221 is energized, a Lorentz force (Fleming) is generated in the OIS coil 221 by the interaction between the magnetic field of the driving magnet 122 and the current flowing through the OIS coil 221. (Fleming) left-hand rule). The direction of the Lorentz force is a direction in which the direction of the magnetic field (Z direction) of the long side portion of the OIS coil 221 is orthogonal to the direction of the current. Since the OIS coil 221 is fixed, a reaction force acts on the driving magnet 122. The reaction force is a driving force of the voice coil motor for OIS, and the OIS movable section 10 having the driving magnet 122 swings in the XY plane to perform shake correction. At this time, the ball 153 slides on the slide plate 23.

When autofocusing is performed in the lens driving device 1, power is applied to the AF coil 112. When the AF coil 112 is energized, a Lorentz force is generated in the AF coil 112 by the interaction of the magnetic field of the driving magnet 122 and the current flowing through the AF coil 112. The direction of the Lorentz force is a direction (Z direction) orthogonal to the direction of the magnetic field and the direction of the current flowing through the AF coil 112. Since the driving magnet 122 is fixed, a reaction force acts on the AF coil 112. The reaction force is the driving force of the voice coil motor for AF, and the AF movable portion 11 having the AF coil 112 moves in the direction of the optical axis to perform focusing.

Furthermore, when no power is applied without focusing, the AF movable section 11 is suspended between the infinity position and the macro position by the upper spring 131, the upper spring 132, and the lower spring 141 and the lower spring 142. State (neutral point). That is, in the OIS movable portion 10, the AF movable portion 11 (the lens holder 111) is opposed to the AF fixed portion 12 (the magnet holder 121) by the upper spring 131, the upper spring 132, the lower spring 141, and the lower spring 142. In the positioned state, it is elastically supported so as to be displaceable toward both sides in the Z direction.

11 (A) and 11 (B) are diagrams showing a contact state between the ball 153 (protruding portion) and the sliding plate 23 (flat portion). FIG. 11 (A) shows a cross section passing through the center in the width direction of one side of the holding member 151. FIG. 11 (B) shows an enlarged dotted line portion in FIG. 11 (A).

As shown in FIGS. 11 (A) and 11 (B), in the lens driving device 1, the balls 153 are urged toward the OIS fixing portion 20, so the balls 153 are in contact with the slide plate 23. Since the ball 153 protrudes more toward the imaging side in the optical axis direction than the bottom surface of the holding member 151, a gap is formed between the bottom surface of the holding member 151 and the upper surface of the slide plate 23. When the OIS movable part 10 swings in the orthogonal plane of the optical axis during the shake correction, the ball 153 slides on the slide plate 23.

In this embodiment, the surface of the slide plate 23 is subjected to a low-friction treatment. In addition, the structure in which the balls 153 are in contact with the slide plate 23 is adopted, and the contact area is extremely small. Therefore, the OIS movable portion 10 and the OIS fixed portion 20 partially abut, but the swing of the OIS movable portion 10 is not prevented.

Here, as shown in FIG. 12 (A), when a force in the optical axis direction is applied to the lens driving device 1 by a drop impact, the force is concentrated on the balls 153. Along with this, the thin-walled portion 151a of the holding member 151 is flexed, and the balls 153 are displaced toward the light-receiving side in the optical axis direction (see FIG. 12 (B)). On the other hand, when the force in the optical axis direction is released, the ball 153 returns to the original state (see FIG. 12 (A)). That is, the ball 153 can be elastically displaced in the optical axis direction.

In this way, the force in the optical axis direction due to the drop impact is absorbed by the sliding portion 15, and thus the forces transmitted to the suspension wire 30, the AF support portion 13, the AF support portion 14, and the like are reduced. Therefore, it is possible to prevent the lens driving device 1 from being damaged by a drop impact, and to reduce the diameter of the suspension wire 30 and reduce the thickness of the AF support portion 13 and the AF support portion 14.

As such, the lens driving device 1 includes: an OIS fixed portion 20 (shake correction fixed portion); an OIS movable portion 10 (shake correction movable portion) that can swing in a plane orthogonal to the optical axis; a suspension line 30 (for shake correction A support section) to support the OIS movable section 10 with respect to the OIS fixed section 20 in a state separated from each other in the optical axis direction; and a voice coil motor (drive source) to swing the OIS movable section 10.
In the lens driving device 1, the OIS movable section 10 (one of the shake correction fixed section and the shake correction movable section) has a ball 153 (projection section) protruding in the optical axis direction. The OIS fixing portion (the other of the shake correction fixing portion and the shake correction movable portion) includes a slide plate 23 (flat portion) that abuts against the ball 153. The balls 153 and the slide plate 23 slide relative to each other during shake correction. Moreover, the balls 153 can be elastically displaced in the direction of the optical axis.

According to the lens driving device 1, a ball 153 is interposed between the OIS movable section 10 and the OIS fixed section 20. Since the OIS movable section 10 is supported by the ball 153, it is held in a stable posture. Thereby, the thinning of the suspension wire 30 and the thinning of the AF support portion 13 and the AF support portion 14 (wire fixing member) are promoted, and even if the rigidity of the member is reduced, it is possible to prevent the movable portion 10 from being caused by the OIS. The performance of the AF function and the OIS function is reduced due to the in-plane displacement of the optical axis or the tilt with respect to the optical axis.
In addition, since the balls 153 are held in an elastically displaceable manner, and the force acting upon a drop impact is absorbed by the sliding portion 15, it is possible to prevent the constituent members of the lens driving device 1 from being damaged.
Therefore, according to the lens driving device 1, miniaturization and weight reduction can be achieved, and reliability can be improved.

As mentioned above, although the invention made by the present inventor was demonstrated concretely based on embodiment, this invention is not limited to the said embodiment, and can be changed in the range which does not deviate from the summary.

For example, in the embodiment, the case where the holding member 151 is recessed to absorb the falling impact is shown. However, a force applying member may be interposed between the holding member 151 and the ball 153, and the force applying member faces the optical axis in the ball 153 Resilience when shifting. For example, a plate spring 154 may be provided as the urging member (see FIG. 13). Since both ends of the leaf spring 154 are fixed by the holding member 151, the self-ball 153 is flexed when receiving a force in the optical axis direction.

A compression coil spring may be disposed as the biasing member. When the compression coil spring is applied, there can be no gap between the holding member 151 and the spacer 152.

In addition, for example, in the embodiment, the case where the holding member 151 has a beam structure with a support at both ends has been described, but as shown in FIG. 14, a cantilever beam structure may be applied. In this case, the holding member 151 may be composed of a plurality of members (see FIG. 15 (A)) or may be composed of one member (see FIG. 15 (B)).

Further, the protruding portion may be integrally formed on the holding member 151. At this time, it is preferable that the front end portion (the portion abutting the sliding plate 23) of the protruding portion has a spherical shape. Thereby, as in the case where the balls 153 are arranged, the sliding property of the OIS movable portion 10 can be secured.

In the embodiment, the slide plate 23 may be omitted, and a part of the base 21 or the coil substrate 22 may function as a flat portion. However, since the flat portion is preferably a rigid body such as metal, the base 21 and the coil substrate 22 may be separately provided.

Moreover, in the embodiment, the case where a protruding portion is provided on the OIS movable portion 10 and a flat portion is provided on the OIS fixed portion 20 is shown. However, a flat portion may be provided on the OIS movable portion 10 and a protrusion may be provided on the OIS fixed portion 20. unit. Furthermore, a low-friction treatment may be applied to not only the flat portion but also the protruding portion.

In the embodiment, as an example of a camera-equipped device having a camera module A, a smartphone M, which is a portable terminal equipped with a camera, has been described. However, the present invention is applicable to a camera having a camera module and processing a camera. A camera-mounted device in an image processing section of the image information obtained by the module. The camera-mounted device includes information equipment and transportation equipment. Information devices include, for example, camera-equipped mobile phones, note-type personal computers (PCs), tablet terminals, portable game machines, web cameras, and camera-equipped Vehicle-mounted devices (for example, a back monitor device, a drive recorder device). The transportation equipment includes, for example, automobiles.

FIGS. 16 (A) and 16 (B) are diagrams showing a car V as a camera mounting device equipped with a vehicle camera module VC (Vehicle Camera). FIG. 16 (A) is a front view of the automobile V, and FIG. 16 (B) is a rear perspective view of the automobile V. FIG. The automobile V is equipped with the camera module A described in the embodiment as the vehicle camera module VC. As shown in FIG. 16 (A) and FIG. 16 (B), the on-vehicle camera module VC is, for example, mounted on a front glass toward the front, or mounted on a rear gate toward the rear. The in-vehicle camera module VC is used for a back-up monitor, a driving recorder, a collision avoidance control, an automatic driving control, and the like.

The configurations of the AF coil, the AF magnet, the OIS coil, and the OIS magnet are not limited to those shown in the embodiments. For example, a driving magnet that also serves as an AF magnet and an OIS magnet may have a rectangular parallelepiped shape and be arranged around the AF coil so that the magnetization direction and the radial direction are consistent with each other. Alternatively, the flat-shaped AF coil may be disposed around the lens portion so that the coil surface is parallel to the optical axis direction, and the rectangular parallelepiped driving magnet may be disposed so that the magnetization direction intersects the coil surface of the AF coil.

In the embodiment, the case where the driving magnet is used as both the AF magnet and the OIS magnet in the lens driving device having the OIS function and the AF function has been described. However, the AF magnet and the OIS magnet may be separately provided. The present invention is applicable to a lens driving device having only an OIS function. Furthermore, the present invention can also be applied to a lens driving device having a driving source (for example, an ultrasonic motor) other than VCM.

In the embodiment, the lens unit 2 is disposed on the OIS movable unit 10, the imaging unit is disposed on the OIS fixed unit 20, and a lens drive having a so-called optical shake correction function that performs shake correction by the lens unit 2 swinging relative to the imaging unit The device 1 has been described, but the present invention is also applicable to a so-called sensor in which a lens portion is disposed on an OIS fixed portion, an image pickup portion is disposed on an OIS movable portion, and a shake correction is performed by the image pickup portion swinging relative to the lens portion. Lens driving device with sensor shifting shake correction function.

It should be understood that the entire contents of the embodiments disclosed in the present invention are illustrative and not restrictive. It means that the scope of the present invention is not represented by the above description, but is expressed by the scope of the patent application, and includes the meaning equivalent to the scope of the patent application and any changes within the scope.

The disclosure of the description, drawings, and abstract contained in the Japanese application for Japanese Patent Application No. 2018-040489 filed on March 7, 2018 is cited in this application.

1‧‧‧ lens driving device

2‧‧‧ lens section

3‧‧‧ cover

3a‧‧‧ opening

10‧‧‧OIS movable section (shake correction movable section)

11‧‧‧AF movable section

12‧‧‧AF fixed part

13, 14‧‧‧AF support department

15‧‧‧ sliding section

20‧‧‧OIS fixed part (shake correction fixed part)

21‧‧‧ base

21a‧‧‧ opening

21b‧‧‧Coil substrate fixing part

21c‧‧‧Sliding plate fixing part

22‧‧‧coil substrate

22a‧‧‧ opening

23‧‧‧Sliding plate (flat part)

23a‧‧‧ The four sides of the sliding plate are approximately centered in the longitudinal direction.

30‧‧‧Hanging line (shake correction support section) / OIS support section

111‧‧‧ lens holder

111a‧‧‧ lens housing

111b‧‧‧upper flange

111c‧‧‧Lower flange

111d‧‧‧ Upper spring fixing part

111e‧‧‧ Lower spring fixing part

112‧‧‧AF Coil

121‧‧‧Magnet holder

121a‧‧‧ opening

121b‧‧‧Magnet holder

121d‧‧‧ Upper spring fixing part

122‧‧‧Drive Magnet (AF Magnet)

131, 132‧‧‧ Upper spring

131a, 132a ‧‧‧ lens holder fixing part

131b, 132b ‧‧‧ magnet holder fixing part

131c, 132c‧‧‧arm

131d, 132d‧‧‧ line connection

131e, 132e‧‧‧ Connection

141, 142‧‧‧ Lower spring

141a, 142a ‧‧‧ lens holder fixing part

141b, 142b‧‧‧‧Magnet holder fixing part

141c, 142c‧‧‧‧arm

151‧‧‧ holding member

151a‧‧‧ (thin-walled portion)

151b‧‧‧ (thick wall)

151c‧‧‧Ball Containment Department

152‧‧‧ spacer

153‧‧‧ball (projection)

154‧‧‧leaf spring

211‧‧‧Terminal metal parts

221‧‧‧OIS coil

A‧‧‧ Camera Module

M‧‧‧ smart phone (camera-mounted device)

OC‧‧‧Back Camera

V‧‧‧ Car

VC‧‧‧Car Camera Module

X‧‧‧ coordinate system / direction

Y‧‧‧ coordinate system / direction

Z‧‧‧ coordinate system / direction

1 (A) and 1 (B) are diagrams showing a smartphone equipped with a camera module according to an embodiment of the present invention.

FIG. 2 is an external perspective view of a camera module.

FIG. 3 is an exploded perspective view of a camera module.

FIG. 4 is an exploded perspective view of a lens driving device.

FIG. 5 is an exploded perspective view of a lens driving device.

FIG. 6 is an exploded perspective view of an OIS movable portion.

FIG. 7 is a cross-sectional view of a movable part of the OIS.

FIG. 8 is a bottom view of the OIS movable portion.

FIG. 9 is an exploded perspective view of an OIS fixing portion.

FIG. 10 is a plan view of an OIS fixing portion.

11 (A) and 11 (B) are diagrams showing a contact state between a protruding portion and a flat portion.

12 (A) and 12 (B) are diagrams showing a displacement state of the protruding portion.

FIG. 13 is a diagram showing another example of the protruding portion.

FIG. 14 is a diagram showing still another example of the protruding portion.

15 (A) and 15 (B) are diagrams showing a cantilever-type projection.

FIGS. 16 (A) and 16 (B) are diagrams showing an automobile as a camera-mounted device equipped with a vehicle-mounted camera module.

Claims (13)

A lens driving device includes: a shake correction fixed portion; a shake correction movable portion capable of swinging in a plane orthogonal to an optical axis; a shake correction support portion that sets the shake correction movable portion relative to the shake correction fixed portion Supported in a state of being spaced apart in the direction of the optical axis; and a driving source that swings the shake correction movable portion; and the lens driving device is characterized by: One of the shake correction fixing portion and the shake correction movable portion has a protruding portion protruding in the optical axis direction, The other of the shake correction fixing portion and the shake correction movable portion has a flat portion that abuts the protruding portion, The protruding portion and the flat portion slide relative to each other during shake correction, The protruding portion can be elastically displaced in the optical axis direction. The lens driving device according to item 1 of the patent application range, wherein the protruding portion applies a force to the flat portion. The lens driving device according to claim 1 or claim 2, wherein a sliding surface of at least one of the protruding portion and the flat portion is subjected to a low-friction treatment. The lens driving device according to item 3 of the patent application scope, wherein the low-friction treatment is a nickel plating treatment in which polytetrafluoroethylene particles are dispersed. The lens driving device according to any one of claims 1 to 4, including a holding member that holds the protruding portion, The holding member has a beam portion that is supported at both ends or cantilevered, The protruding portion is disposed on the beam portion. The lens driving device according to any one of claims 1 to 4 in the patent application scope, comprising: a holding member that holds the protruding portion; and The urging member is interposed between the holding member and the protruding portion, and The urging member exerts a restoring force when the protruding portion is displaced in the optical axis direction. The lens driving device according to item 6 of the scope of application for a patent, wherein the force applying member is a leaf spring mounted on the holding member with both ends supported or cantilevered. The lens driving device according to item 6 of the patent application scope, wherein the urging member is a compression coil spring. The lens driving device according to any one of claims 1 to 8, wherein the protruding portion has a spherical shape and is in point contact with the flat portion. The lens driving device according to item 9 of the patent application scope, wherein the protrusion includes a ball member. The lens driving device according to any one of claims 1 to 10, wherein the driving source includes: A shake correction magnet is disposed on either of the shake correction fixed portion and the shake correction movable portion; and The shake correction coil is disposed on either of the shake correction fixing section and the shake correction movable section. A camera module, comprising: the lens driving device according to any one of claims 1 to 11 in the scope of patent application; A lens portion mounted on the shake correction movable portion; and The imaging unit captures a subject image formed by the lens unit. A camera mounting device is a camera mounting device as an information device or a transportation device, and is characterized by including: A camera module as described in claim 12; and The image processing unit processes image information obtained by the camera module.