CN111727405A - Lens driving device, camera module, and camera-mounted device - Google Patents

Abstract

The invention provides a lens driving device, a camera module and a camera carrying device which can achieve miniaturization and light weight and can improve reliability. The lens driving device includes: a shake correction fixing section; a shake correction movable portion that is swingable within a plane orthogonal to the optical axis; a shake correction support portion that supports the shake correction movable portion in a state where the shake correction movable portion is spaced apart from the shake correction fixing portion in an optical axis direction; and a drive source that swings the shake correction movable portion. One of the shake correction fixing section and the shake correction movable section has a protruding section protruding in the optical axis direction. The other of the shake correction fixing section and the shake correction movable section has a flat section that abuts against the protruding section. The protruding portion and the flat portion slide relatively at the time of shake correction. The protruding portion is elastically displaceable in the optical axis direction.

Description

Lens driving device, camera module, and camera-mounted device

technical field

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

Background technique

In general, a small camera module is mounted in a portable terminal such as a smartphone. In such a camera module, the application has an auto focus function (hereinafter referred to as "AF function", AF: Auto Focus) and a shake correction function (hereinafter referred to as "OIS function", OIS: Optical Image Stabilization (Optical Image Stabilization) anti-shake)), the auto focus function is a function of automatically performing focus adjustment when shooting a subject, and the shake correction function is a function of optically correcting the shake (vibration) generated during shooting to reduce image blurring. (For example, Patent Documents 1 and 2).

A lens driving device having an autofocus function and a shake correction function includes a drive unit for autofocus (hereinafter referred to as an "AF drive unit") for moving the lens unit in the direction of the optical axis, and a drive unit for moving the lens unit in the direction of the optical axis. Shake correction drive unit (hereinafter referred to as "OIS drive unit") oscillating in planes with directions orthogonal to each other. 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 section (hereinafter referred to as "OIS movable section") that swings in a plane orthogonal to the optical axis direction during shake correction. The OIS movable portion is supported by the shake correction fixed portion (hereinafter, referred to as the "OIS fixed portion") via the shake correction support portion (hereinafter referred to as the "OIS support portion"). In the lens driving device disclosed in Patent Document 1, the OIS support portion is constituted by a suspension wire (Japanese: サスペンションワイヤー) extending in the optical axis direction, and the OIS movable portion is held at a distance from the OIS fixed portion in the optical axis direction. open state.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2013-210550

Patent Document 2: Japanese Patent Application Laid-Open No. 2012-177753

SUMMARY OF THE INVENTION

Invention to solve problem

In recent years, in order to achieve miniaturization (thinning) and weight reduction of camera-mounted devices such as smartphones, further miniaturization and weight reduction of lens drive devices are required. Along with this, in the lens drive device of the wire support method disclosed in Patent Document 1, the suspension wire is thinned and the member for fixing the suspension wire (hereinafter, referred to as "wire fixing member") is reduced in thickness.

However, with the thinning of the suspension wire and the thinning of the wire fixing member, their rigidity has been reduced, so there is a concern that the OIS may become unstable due to changes in the posture of the lens driving device, displacement of the lens during focusing, and the like. The movable portion is displaced in a plane orthogonal to the optical axis or tilted with respect to the optical axis, thereby degrading the performance of the AF function and the OIS function.

An object of the present invention is to provide a lens driving device, a camera module, and a camera mounting device that can achieve reduction in size and weight and can improve reliability.

solution to the problem

The present invention provides a lens driving device comprising: a shake correction fixed portion; a shake correction movable portion capable of swinging in a plane orthogonal to an optical axis; and a shake correction support portion for enabling the shake correction a movable portion supports the shake correction movable portion in a state of being spaced apart from the shake correction fixed portion in the optical axis direction; and a drive source that swings the shake correction movable portion, the lens driving device is characterized in that , one of the shake correction fixed portion and the shake correction movable portion has a protruding portion protruding in the optical axis direction, and the other of the shake correction fixed portion and the shake correction movable portion has a A flat portion to which the protruding portion abuts, the protruding portion and the flat portion slide relative to each other during shake correction, and the protruding portion can be elastically displaced in the optical axis direction.

The present invention provides a camera module, comprising: the lens driving device described above; the lens unit attached to the shake correction movable unit; and an imaging unit that images an image passing through the lens unit to shoot the subject image.

The present invention provides a camera mounting device, which is an information device or a conveying device, characterized in that the camera mounting device includes: the camera module described above; and an image processing unit that processes an image obtained by the camera module. information is processed.

effect of invention

According to the present invention, the lens driving device, the camera module, and the camera-mounted device can be reduced in size and weight, and reliability can be improved.

Description of drawings

1A and 1B are diagrams showing a smartphone on which a camera module according to an embodiment of the present invention is mounted.

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

3 is an exploded perspective view of the camera module.

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

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

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

7 is a cross-sectional view of an OIS movable portion.

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

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

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

11A and 11B are diagrams showing the contact state between the protruding portion and the flat portion.

12A and 12B are diagrams showing the 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.

15A and 15B are diagrams showing a cantilever-type protrusion.

16A and 16B are diagrams showing an automobile as a camera-mounted device on which an in-vehicle camera module is mounted.

Detailed ways

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

1A and 1B are diagrams showing a smartphone M (camera mounting device) on which a camera module A according to an embodiment of the present invention is mounted. 1A is a front view of the smartphone M, and FIG. 1B is a rear view of the smartphone M.

The smartphone M is equipped with, for example, the camera module A as the rear camera OC. The camera module A is provided with an AF function and an OIS function, can automatically perform focus adjustment when photographing a subject, and can optically correct shake (vibration) generated during photographing to photograph a blur-free image.

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, a description is made using an orthogonal coordinate system (X, Y, Z). In the drawings to be described later, it is also represented by a common orthogonal coordinate system (X, Y, Z).

When actually photographing with the smartphone M, the camera module A is mounted so that the X direction is the up-down direction (or the left-right direction), the Y direction is the left-right direction (or the up-down direction), and the Z direction is the front-rear 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. In addition, the X direction and the Y direction orthogonal to the Z axis are referred to as "optical axis orthogonal directions", and the XY plane is referred to as "optical axis orthogonal planes".

As shown in FIGS. 2 and 3 , the camera module A includes a lens driving device 1 that realizes an AF function and an OIS function, a lens unit 2 that accommodates a lens in a cylindrical lens barrel, and a subject that forms an image through the lens unit 2 . An imaging unit (not shown) that captures a subject image, a cover 3 that covers the entirety, and the like. In addition, in FIG. 3, the lens part 2 is abbreviate|omitted.

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

The imaging unit (not shown) is arranged 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 constituted by, for example, a CCD (charge-coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor: complementary metal oxide semiconductor) type 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 thereto. The control unit that performs drive control of the lens driving device 1 may be provided on the image sensor substrate, or may be provided in a camera-mounted device (in this embodiment, a smartphone M) 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 the present embodiment, the lens driving device 1 includes an OIS movable portion 10 , an OIS fixing portion 20 , an OIS support portion 30 , and the like. In the present embodiment, the drive source of the lens drive device 1 is constituted by a voice coil motor (VCM).

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

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

One end of the suspension wire 30 (the end on the light-receiving side in the optical axis direction, the upper end) is fixed to the OIS movable part 10 (in this embodiment, it is fixed to the AF support part 13 (see FIG. 6 )), and the other end of the suspension wire 30 ( The end portion on the imaging side in the optical axis direction) is fixed to the OIS fixing portion 20 (in this embodiment, it is fixed to the chassis 21 (see FIG. 9 )). The OIS movable part 10 is supported by the suspension wire 30 so as to be able to swing within a plane orthogonal to the optical axis. Two suspension wires 30 out of the four suspension wires 30 are used as power supply paths for supplying power to the AF coil 112 .

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

As shown in FIGS. 6 to 8 , in the present embodiment, the OIS movable portion 10 includes an AF movable portion 11 , an AF fixed portion 12 , and AF support portions 13 and 14 , and the like. The AF movable portion 11 is arranged radially inward with a distance from the AF fixed portion 12 , and is coupled to the AF fixed portion 12 via the AF support portions 13 and 14 .

The AF movable portion 11 has an AF coil 112 constituting a voice coil motor for AF, and is a portion that moves in the optical axis direction during focus adjustment. The AF fixed portion 12 includes a drive magnet 122 (an AF magnet) constituting a voice coil motor for AF, and is a portion that supports the AF movable portion 11 via the AF support portions 13 and 14 . That is, the AF drive unit of the lens drive device 1 is of a moving coil type.

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

In addition, in the present embodiment, the OIS movable portion 10 includes the sliding portion 15 on the imaging side in the optical axis direction, and the sliding portion 15 is arranged so as to partially contact the OIS fixing portion 20 and is connected to the OIS fixing portion during shake correction. 20 slides relatively.

As shown in FIGS. 6 to 8 , in the OIS movable portion 10 , the AF movable portion 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 has a cylindrical lens housing portion 111a, and an upper flange 111b and a lower flange 111c protruding radially outward from the lens housing portion 111a. 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 plan view.

The coil 112 for AF is wound around the part (henceforth "coil winding part") pinched|interposed by the upper flange 111b and the lower flange 111c. The coil winding portion (reference numeral is omitted) 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 housing portion 111a can be prevented, and it is possible to Maintain true roundness.

The lens portion (see FIG. 2 ) is fixed to the lens housing portion 111 a by, for example, adhesive bonding. Preferably, the lens accommodating portion 111a has a groove (not shown) to which the adhesive is applied on the inner peripheral surface. In the method of attaching the lens portion 2 to the lens housing portion 111a by screwing, the suspension wire 30 supporting the OIS movable portion 10 may be damaged. On the other hand, in the present 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 attached. In addition, when the inner peripheral surface of the lens accommodating portion 111a has a groove, an appropriate amount of adhesive is held by the groove, so that the adhesive strength between the lens holder 111 and the lens portion 2 is improved.

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

Moreover, the lens holder 111 has a binding part (illustration omitted) which binds the edge part of the coil 112 for AF.

In the present embodiment, the lens holder 111 is formed of a molding material containing polyarylate (PAR) or a PAR alloy obtained by mixing a plurality of resin materials containing PAR. In particular, the PAR alloy is preferably a polymer alloy (PAR/PC) comprising PAR and polycarbonate (PC). Thereby, since the fusion strength is improved compared with the conventional molding material (for example, liquid crystal polymer (LCP: Liquid Crystal Polymer), even if the lens holder 111 is made thinner, toughness and impact resistance can be ensured. , the outer dimensions of the lens driving device 1 can be reduced, and miniaturization and weight reduction can be achieved. In addition, the lens holder 111 may be formed of a liquid crystal polymer or the like.

In addition, it is preferable that the lens holder 111 is formed by injection molding of a multi-point gate. In this case, the gate diameter is preferably 0.3 mm or more. As a result, the fluidity during molding is good, so even when PAR or a PAR alloy is used as a molding material, thin-wall molding can be realized, and generation of sink marks (Japanese: ヒケ) can be prevented.

The molding material containing PAR or PAR alloy has electrical conductivity, and in particular, the volume resistivity is preferably 10 ⁹ Ω·cm to 10 ¹¹ Ω·cm. For example, conductivity can be easily imparted by mixing carbon nanotubes into existing PAR or PAR alloys. In this case, appropriate conductivity can be imparted by adjusting the content of carbon nanotubes. Thereby, since the charging of the lens holder 111 can be suppressed, the 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 around the outer peripheral surface of the coil winding portion (reference numeral omitted) of the lens holder 111 . Both ends of the AF coil 112 are respectively bound to binding portions (not shown) of the lens holder 111 . The AF coil 112 is energized via the AF support portion 13 (upper springs 131 , 132 ) or the AF support portion 14 (lower springs 141 , 142 ). The energization current of the AF coil 112 is controlled by a drive control unit provided on the image sensor substrate.

As shown in FIGS. 6 to 8 , in the OIS movable portion 10 , the AF fixing portion 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 the present embodiment, the magnet holder 121 is constituted by a frame body having a substantially octagonal shape in plan view. The magnet holder 121 has an opening 121a formed by cutting out a portion corresponding to the lens holder 111 . In the present embodiment, the magnet holder 121 has magnet holding portions 121b that hold the driving magnets 122 on the inner peripheral surface at the positions corresponding to the four corners of the lens driving device 1 . The inner surface of the magnet holding portion 121b serves as a bonding surface to which the driving magnet 122 is bonded.

The adhesive surface of the magnet holding portion 121b is parallel to the optical axis direction, and the end portion on the imaging side in the optical axis direction (the end portion on the OIS fixing portion 20 side in the optical axis direction) is open. The reason for this is that the driving magnet 122 is also used as an OIS magnet, and it is preferable that there is no foreign matter between the driving magnet 122 and the OIS coil 221 (see FIG. 9 ) arranged in the OIS fixing portion 20 from the viewpoint of magnetic properties. That is, the driving magnets 122 are not fixed in a physically non-detachable manner by the shape of the magnet holding portion 121b, but are fixed only by the adhesive force of the adhesive.

The outer peripheral surface of the position corresponding to the four corners of the lens driving device 1 of the magnet holder 121 is cut in a straight line. The suspension wire 30 is arranged in this part. In addition, in the magnet holder 121, the part where the suspension wire 30 is arrange|positioned may be formed so that it may be recessed radially inward in the shape of an arc. Thereby, interference between the suspension wire 30 and the magnet holder 121 can be avoided when the OIS movable portion 10 swings without increasing the external shape of the lens driving device 1 .

The magnet holder 121 has an upper spring fixing portion 121d for fixing the AF support portion 13 on the upper surface. In the present embodiment, upper spring fixing portions 121 d are provided on the upper surface of the magnet holder 121 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) on the lower surface for fixing the AF support portion 14 . In the present embodiment, similarly to 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 to be recessed from the image-forming side in the optical axis direction to which the AF support portion 13 is attached, so that a gap is formed when the AF support portion 13 is attached.

In the present embodiment, the magnet holder 121 is formed of liquid crystal polymer. The magnet holder 121 may be formed of a molding material containing PAR or a PAR alloy similarly to the lens holder 111, but is preferably formed of a liquid crystal polymer having excellent heat resistance. Since the magnet holder 121 has high heat resistance, the welding of the AF support parts 13 and 14 and the like can be easily performed (Japanese: Handadasuke). The magnet holder 121 is formed, for example, by injection molding using a mold.

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

In the present embodiment, the driving magnet 122 is fixed to the magnet holding portion 121b of the magnet holder 121 by adhesion. As the adhesive, for example, an epoxy resin-based thermosetting adhesive or an ultraviolet curing adhesive is used. The surfaces of the driving magnets 122 in contact with the magnet holding portions 121b (in the present embodiment, the side surfaces and the upper surfaces other than the surfaces exposed on the inside) serve as the adhesive surfaces.

The AF voice coil motor is constituted by the drive magnet 122 and the AF coil 112 . In the present embodiment, the drive magnet 122 serves as both the AF magnet and the OIS magnet. In addition, 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 springs 131 and 132 ) is capable of AF on the light receiving side in the optical axis direction with respect to the AF fixing portion 12 (magnet holder 121 ). The movable portion 11 (the lens holder 111 ) is elastically supported. The upper springs 131 and 132 are formed of, for example, titanium copper, nickel copper, stainless steel, or the like.

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

The upper springs 131 and 132 respectively have lens holder fixing parts 131a and 132a fixed to the lens holder 111, magnet holder fixing parts 131b and 132b fixed to the magnet holder 121, and the lens holder fixing parts 131a and 132a and The arm parts 131c and 132c are connected to the magnet holder fixing parts 131b and 132b. The arm portions 131c and 132c are formed to be curved, and elastically deform when the AF movable portion 11 moves in the optical axis direction.

In addition, the upper springs 131 and 132 have wire connection parts 131d and 132d connected to the suspension wire 30, respectively. The wire connection parts 131d and 132d are connected to the magnet holder fixing parts 131b and 132b via the connection parts 131e and 132e extending in a meandering shape.

In the present embodiment, the upper springs 131 and 132 are electrically connected to the binding portion (not shown) of the lens holder 111 , and the AF coil 112 is energized through the upper springs 131 and 132 .

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

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

The lower springs 141 and 142 respectively have lens holder fixing parts 141a and 142a fixed to the lens holder 111, magnet holder fixing parts 141b and 142b fixed to the magnet holder 121, and the lens holder fixing parts 141a and 142a and 142b. The arm parts 141c and 142c are connected to the magnet holder fixing parts 141b and 142b. The arm portions 141c and 142c are formed to be curved, and elastically deform when the AF movable portion 11 moves in the optical axis direction.

In the present embodiment, as shown in FIGS. 6 to 8 , in the OIS movable portion 10 , the sliding portion 15 is constituted by a holding member 151 , a spacer 152 , and a spherical body 153 . The sliding portion 15 is arranged at the position closest to the imaging side in the optical axis direction of the OIS movable portion 10 , and is in contact with the OIS fixing portion 20 .

In the present embodiment, the spherical body 153 corresponds to the protruding portion of the present invention. That is, the spherical body 153 protrudes toward the imaging side in the optical axis direction, and is in contact with the sliding plate 23 (see FIG. 9 , flat portion) of the OIS fixing portion 20 . By using the spherical body 153 as the protruding portion, the sliding plate 23 is in point contact with the sliding plate 23 and the contact area is small, so that the slidability at the time of shake correction can be ensured. Furthermore, the ball 153 slides on the slide plate 23 during shake correction, instead of rolling.

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

The holding member 151 has a thick portion 151b and a thin portion 151a. In the present embodiment, the approximately center in the longitudinal direction of the four sides of the holding member 151 is the thin portion 151a. The holding member 151 has a spherical body accommodating portion 151c that accommodates the spherical body 153 on the bottom surface side of the thin portion 151a. The spherical body accommodating part 151c has a depression (reference numeral is omitted) corresponding to the shape of the spherical body 153 in the center. The spherical body 153 is arranged in this recess.

The thin portion 151a is thinner than the thick portion 151b, and is formed so as to be elastically deformable in the optical axis direction. In the present embodiment, the upper surface of the thin portion 151a is formed to be recessed, and when a force in the optical axis direction is received, it is deflected toward the light receiving side in the optical axis direction to release the stress. That is, in the sliding portion 15, the holding member 151 has a beam structure supported by both ends. In addition, a spherical body 153 serving as a protruding portion is arranged on the thin portion 151a serving as a beam portion. The depression of the upper surface of the thin-walled portion 151a is preferably larger than the gap formed between the holding member 151 and the slide plate 23 (see FIG. 12A ).

The spacer 152 is a frame having a substantially rectangular shape in plan view like the holding member 151 , and is bonded 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 copper alloy.

The spherical body 153 is formed of a metal material such as zirconia. The spherical body 153 is arranged in the spherical body accommodating portion 151 c of the holding member 151 . The spherical body 153 is interposed between the OIS movable part 10 and the OIS fixed part 20 . When the OIS movable part 10 and the OIS fixed part 20 are connected by the suspension wire 30 , the spherical body 153 is in a state of being urged against the OIS fixed part 20 (slide plate 23 ). Thereby, the spherical body 153 comes into contact with the OIS fixing portion 20 reliably.

In the present embodiment, the OIS movable portion 10 is supported by the four spherical bodies 153 . Thereby, the OIS movable part 10 is held in a stable posture with respect to the OIS fixed part 20 . In addition, from the viewpoint of stabilizing the posture of the OIS movable portion 10 , it is preferable that there are three or more spherical bodies 153 (protrusions), that is, the OIS movable portion 10 is supported at three or more points.

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

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

The base 21 is a support member that supports the coil substrate 22 and the slide plate 23 . The base 21 is a member having a rectangular shape in plan view, and has a substantially circular opening 21a in the center. Terminal fittings 211 are embedded in the base 21 . The terminal fitting 211 is integrally formed with the base 21 by, for example, insert molding. In the present embodiment, the terminal fittings 211 are exposed from the four corners of the base 21 . The terminal fitting 211 is soldered to the power supply terminal (not shown) of the coil substrate 22 and the suspension wire 30 , and is physically and electrically connected thereto.

In the present embodiment, like the lens holder 111 , the base 21 is formed of a molding material containing polyarylate (PAR) or PAR alloy (for example, PAR/PC), which is a plurality of resin materials that will contain PAR mixed. Thereby, since the fusion strength is improved, even if the base 21 is made thinner, toughness and impact resistance can be ensured. Therefore, the external dimension of the lens driving device 1 can be reduced, and miniaturization and low profile can be achieved.

In addition, it is preferable that the base 21 is formed by injection molding of a multi-point gate. In this case, the gate diameter is preferably 0.3 mm or more. As a result, the fluidity during molding is good, and therefore, even when PAR or a PAR alloy is used as a molding material, thin-wall molding can be realized, and generation of sink marks can be prevented.

The molding material containing PAR or PAR alloy has electrical conductivity, and in particular, the volume resistivity is preferably 10 ⁹ Ω·cm to 10 ¹¹ Ω·cm. For example, conductivity can be imparted by mixing carbon nanotubes into existing PAR or PAR alloys. In this case, appropriate conductivity can be imparted by adjusting the content of carbon nanotubes. Thereby, since the electrification of the chassis 21 can be suppressed, the generation of static electricity can be prevented.

The base 21 has a coil substrate fixing portion 21b on which the coil substrate 22 is arranged, and a sliding plate fixing portion 21c on which the sliding plate 23 is arranged, on the periphery of the opening 21a. The coil substrate fixing portion 21b is formed on the inner peripheral side of the sliding plate fixing portion 21c so as to be recessed from the sliding plate fixing portion 21c. The upper surface of the sliding plate 23 arranged in the sliding plate fixing portion 21c is positioned on the light receiving side in the optical axis direction rather than the upper surface of the coil substrate 22 arranged in the coil substrate fixing portion 21b. Thereby, a gap is reliably formed between the coil substrate 22 and the OIS movable portion 10 (holding member 151 ).

As shown in FIGS. 9 and 10 , in the OIS fixing portion 20 , the coil substrate 22 is a substrate having a rectangular shape in plan view like 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 a unit layer including a conductor layer and an insulating layer (not shown) is laminated in multiple layers. On the coil substrate 22, for example, an OIS coil 221, an external terminal (not shown), and a conductor pattern (not shown) including a power supply line connecting the external terminal and the OIS coil 221 are integrally formed.

In the OIS fixing portion 20 , like the holding member 151 , the slide plate 23 is a frame body having a substantially rectangular shape in plan view. The sliding plate 23 is formed of a metal material such as copper alloy, for example. In the present embodiment, the slide plate 23 corresponds to the 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 spherical body 153 . The substantially center 23 a in the longitudinal direction of the four sides of the slide plate 23 serves as a contact portion with which the spherical body 153 abuts. The width of the slide plate 23 can be appropriately set according to the swing range of the OIS movable portion 10 .

In the present embodiment, the sliding surface of the sliding plate 23 is subjected to low-friction treatment. For the low-friction treatment, for example, Ni plating treatment in which PTFE (Polytetrafluoroethylene) is dispersed can be applied. As a result, the frictional force generated when the spherical body 153 slides on the sliding plate 23 can be reduced, so that the slidability during shake correction can be ensured.

In the present embodiment, the base 21 , the coil substrate 22 and the slide plate 23 are bonded together by an epoxy resin material having elasticity. By integrating the base 21 , the coil substrate 22 , and the sliding plate 23 by bonding, the mechanical strength of the OIS fixing portion 20 is improved. Therefore, the base 21 , the coil substrate 21 and the coil substrate can be integrated while ensuring the desired drop impact resistance. 22 and the sliding plate 23 are thinned.

In the lens driving device 1, one end of the suspension wire 30 is physically and electrically connected to the wire connecting portions 131d and 132d of the upper springs 131 and 132, respectively. The other end of the suspension wire 30 is physically and electrically connected to the terminal fitting 211 of the base 21 (the part exposed from the cutouts at the four corners). When the OIS movable part 10 and the OIS fixed part 20 are connected by the suspension wire 30 , the spherical body 153 is in a state of being urged against the OIS fixed part 20 (slide plate 23 ).

In addition, the lens driving device 1 may include a Z position detection unit that detects the position in the optical axis direction of the AF movable unit 11 and/or a Z position detection unit that detects the position in the plane orthogonal to the optical axis of the OIS movable unit 10 . XY position detection unit. For example, the Z position detection unit and the XY position detection unit can be constituted by a magnet for position detection and a Hall element, respectively. The Hall element and the magnet for position detection are arranged to face each other.

In the case of the Z position detection unit, for example, a detection magnet is arranged on the AF movable unit 11 (eg, the lens holder 111 ), and a Hall element is arranged on the AF fixed unit 12 (eg, the magnet holder 121 ). When the AF movable portion 11 moves in the optical axis direction, the magnetic field by the position detection magnet changes. The change in the magnetic field is detected by the Hall element, thereby detecting the position of the AF movable portion 11 in the optical axis direction. In addition, a control IC with a built-in Hall element may be arranged in the AF fixing portion 12 , and the energization current of the AF coil 112 may be controlled by the control IC.

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

By performing closed-loop control based on the Hall output, the response performance is improved, so that the AF operation or the OIS operation can be accelerated.

When performing shake correction in the lens driving device 1 , the OIS coil 221 is energized. Specifically, in the OIS drive unit, the energization current of the OIS coil 221 is controlled based on a detection signal from a shake detection unit (not shown, for example, a gyro sensor) so that the shake of the camera module A is canceled.

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

When autofocusing is performed in the lens driving device 1 , the AF coil 112 is energized. When the AF coil 112 is energized, a Lorentz force is generated in the AF coil 112 due to the interaction between the magnetic field of the driving magnet 122 and the current flowing in 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 in the AF coil 112 . Since the driving magnet 122 is fixed, a reaction force acts on the AF coil 112 . This reaction force becomes the driving force of the AF voice coil motor, and the AF movable portion 11 having the AF coil 112 moves in the optical axis direction to perform focus adjustment.

In addition, when the focus is not turned on, the AF movable part 11 is suspended between the infinity position and the macro position (neutral point) by the upper springs 131 and 132 and the lower springs 141 and 142 . That is, in the OIS movable portion 10 , the AF movable portion 11 (lens holder 111 ) is elastically supported by the upper springs 131 , 132 and the lower springs 141 , 142 so as to be able to be fixed relative to the AF fixed portion 12 (the magnet holder 121 ). ) is shifted to both sides in the Z direction.

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

As shown in FIGS. 11A and 11B , in the lens driving device 1 , since the spherical body 153 is urged toward the OIS fixing portion 20 , the spherical body 153 and the sliding plate 23 are in contact with each other. Since the spherical body 153 protrudes from the bottom surface of the holding member 151 to the imaging side in the optical axis direction, 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 portion 10 swings within a plane orthogonal to the optical axis during shake correction, the spherical body 153 slides on the slide plate 23 .

In the present embodiment, the surface of the sliding plate 23 is subjected to low-friction treatment. In addition, the spherical body 153 and the sliding plate 23 are in contact with each other, and the contact surface is positively small. Therefore, although the OIS movable portion 10 and the OIS fixed portion 20 are partially in contact with each other, the swinging of the OIS movable portion 10 is not hindered.

Here, as shown in FIG. 12A , when a force in the optical axis direction acts on the lens driving device 1 by the drop impact, the force is concentrated on the sphere 153 . Along with this, the thin portion 151a of the holding member 151 is deflected, and the spherical body 153 is displaced toward the light-receiving side in the optical axis direction (see FIG. 12B ). On the other hand, when the force in the optical axis direction is released, the spherical body 153 returns to its original state (see FIG. 12A ). That is, the spherical body 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, so that the force transmitted to the suspension wire 30, the AF support portions 13 and 14, and the like is reduced. Therefore, it is possible to prevent the lens drive device 1 from being damaged due to a drop impact, and to reduce the diameter of the suspension wire 30 and to reduce the thickness of the AF support parts 13 and 14 .

In this way, the lens driving device 1 includes: the OIS fixed part 20 (shake correction fixed part); the OIS movable part 10 (shake correction movable part) which can swing in a plane orthogonal to the optical axis; the suspension wire 30 (shake correction movable part) with a support portion) that supports the OIS movable portion 10 in a state where the OIS movable portion 10 is spaced from the OIS fixed portion 20 in the optical axis direction; and a voice coil motor (drive source) that causes the OIS movable portion 10 swings.

In the lens driving device 1 , the OIS movable portion 10 (one of the shake correction fixed portion and the shake correction movable portion) has a spherical body 153 (protruding portion) that protrudes in the optical axis direction. The OIS fixed portion (the other of the shake correction fixed portion and the shake correction movable portion) has a sliding plate 23 (flat portion) that is in contact with the spherical body 153 . The spherical body 153 and the slide plate 23 slide relatively at the time of shake correction. Also, the spherical body 153 can be elastically displaced in the optical axis direction.

According to the lens driving device 1 , the spherical body 153 is interposed between the OIS movable portion 10 and the OIS fixed portion 20 , and the OIS movable portion 10 is supported by the spherical body 153 , so that the OIS movable portion 10 is held in a stable posture. Thereby, even if the rigidity of the AF support parts 13 and 14 (wire fixing members) decreases due to the thinning of the suspension wire 30 and the thinning of the walls of the AF support parts 13 and 14 (wire fixing members), the OIS movable part 10 can be prevented from being in the plane orthogonal to the optical axis. When shifting or tilting with respect to the optical axis reduces the performance of the AF function and the OIS function.

In addition, since the spherical body 153 is held to be elastically displaceable, the force acting upon falling impact is absorbed by the sliding portion 15 , and therefore, damage to the constituent members of the lens driving device 1 can also be prevented.

Therefore, according to the lens driving device 1, the size and weight can be reduced, and the reliability can be improved.

As mentioned above, although the invention made by the present inventors was specifically described based on embodiment, this invention is not limited to the said embodiment, It can change in the range which does not deviate from the summary.

For example, in the embodiment, the case where the holding member 151 is deflected to absorb a drop impact is shown, but an urging member that exerts a restoring force when the spherical body 153 is displaced in the optical axis direction may be interposed between the holding member 151 and the spherical body between 153. For example, a leaf spring 154 (see FIG. 13 ) may be provided as the biasing member. Both ends of the leaf spring 154 are fixed by the holding members 151 , and thus deflect when a force in the optical axis direction is received from the spherical body 153 .

In addition, a coil compression spring may be arranged as the biasing member. In the case of applying the helical compression spring, there may 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 supported 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 formed of a plurality of members (see FIG. 15A ), or the holding member 151 may be formed of a single member (see FIG. 15B ).

In addition, the protruding portion may be integrally formed on the holding member 151 . In this case, it is preferable that the front-end|tip part (the part which abuts on the slide plate 23) of a protrusion part has a spherical shape. Thereby, the sliding property of the OIS movable part 10 can be ensured similarly to the case where the spherical body 153 is arrange|positioned.

In addition, 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, it is preferable to provide it independently of the base 21 and the coil substrate 22 .

In addition, in the embodiment, the case where the protruding portion is provided on the OIS movable portion 10 and the flat portion is provided on the OIS fixing portion 20 is shown, but the OIS movable portion 10 may be provided with a flat portion and the OIS fixing portion may be provided with a flat portion. 20 Set the protrusions. Furthermore, not only the flat portion but also the low-friction treatment may be applied to the protruding portion.

In the embodiments, the smartphone M, which is a portable terminal with a camera, is described as an example of the camera-mounted device including the camera module A, but the present invention can be applied to a camera module and an image obtained by the camera module. A camera-mounted device of an image processing unit that processes information. The camera-mounted device includes information equipment and conveyance equipment. The information equipment includes, for example, a mobile phone with a camera, a notebook computer, a tablet terminal, a portable game console, a web camera, and an in-vehicle device with a camera (eg, a rear monitor device, a driving recorder device). In addition, the conveying apparatus includes, for example, an automobile.

16A and 16B are diagrams showing a vehicle V as a camera-mounted device on which a vehicle-mounted camera module VC (Vehicle Camera) is mounted. 16A is a front view of the automobile V, and FIG. 16B is a rear perspective view of the automobile V. FIG. The vehicle V is equipped with the camera module A described in the embodiment as the in-vehicle camera module VC. As shown in FIGS. 16A and 16B , the in-vehicle camera module VC is, for example, attached to the front windshield so as to face the front, or attached to the tailgate so as to face the rear. The in-vehicle camera module VC is used for rear monitors, driving recorders, collision avoidance control, automatic driving control, and the like.

In addition, the structure of the coil for AF, the magnet for AF, the coil for OIS, and the magnet for OIS is not limited to the structure shown in embodiment. For example, a driving magnet that is used both as an AF magnet and an OIS magnet may have a rectangular parallelepiped shape, and may be arranged around the AF coil so that the magnetization direction coincides with the radial direction. Alternatively, a flat-shaped AF coil may be arranged around the lens portion such that the coil surface is parallel to the optical axis direction, and a rectangular parallelepiped-shaped driving magnet may be arranged such that the magnetization direction intersects the coil surface of the AF coil. .

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

In the embodiment, the lens unit 2 is arranged on the OIS movable unit 10 and the imaging unit is arranged on the OIS fixed unit 20 , and the lens unit 2 is oscillated relative to the imaging unit to perform a so-called optical shake correction, which is so-called optical shake correction. The functional lens driving device 1 has been described, but the present invention can also be applied to a lens unit arranged on the OIS fixed unit, the imaging unit arranged on the OIS movable unit, and having a device that performs shake correction by swinging the imaging unit relative to the lens unit. , The so-called sensor shift type shake correction function of the lens driving device.

All the inventive points of the embodiments disclosed this time are illustrative and should not be construed as limiting the present invention. The scope of the present invention is shown not by the above-mentioned description but by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

All the disclosures of the specification, drawings, and abstract included in Japanese Patent Application No. 2018-040489 for which it applied on March 7, 2018 are incorporated in the present application.

Description of reference numerals

1. Lens driving device; 2. Lens part; 3. Cover; 10. OIS movable part (shake correction movable part); 11, AF movable part; 12, AF fixed part; 13, 14, AF support part ; 15, sliding part; 20, OIS fixing part (shake correction fixing part); 21, base; 22, coil substrate; 23, sliding plate (flat part); 30, supporting part for OIS; 111, lens holder; 112 , AF coil; 121, magnet holder; 122, driving magnet; 151, holding member; 152, spacer; 153, sphere (protrusion); 221, coil for OIS; M, smartphone; A, camera module .

Claims (13)

1. A lens driving device includes: a shake correction fixing section; a shake correction movable portion that is swingable within a plane orthogonal to the optical axis; a shake correction support portion that supports the shake correction movable portion in a state where the shake correction movable portion is spaced apart from the shake correction fixing portion in an optical axis direction; and a drive source that swings the shake correction movable portion, the lens drive device being characterized in that,

one of the shake correction fixing section and the shake correction movable section has a protruding section protruding in the optical axis direction,

the other of the shake correction fixed portion and the shake correction movable portion has a flat portion abutting against the protruding portion,

the protruding portion and the flat portion slide relatively at the time of shake correction,

the protruding portion is elastically displaceable in the optical axis direction.

2. The lens driving device according to claim 1,

the protruding portion is urged against the flat portion.

3. The lens driving device according to claim 1 or 2,

the sliding surface of at least one of the protruding portion and the flat portion is subjected to a low friction treatment.

4. The lens driving device according to claim 3,

the low friction treatment is a Ni plating treatment in which PTFE particles are dispersed.

5. The lens driving device according to any one of claims 1 to 4,

the lens driving device comprises a holding member for holding the projection,

the holding member has a beam portion supported at both ends or a cantilevered beam portion,

the protruding portion is disposed on the beam portion.

6. The lens driving device according to any one of claims 1 to 4,

the lens driving device includes:

a holding member that holds the protruding portion; and

a biasing member interposed between the holding member and the protruding portion,

the urging member exerts a restoring force when the protruding portion is displaced in the optical axis direction.

7. The lens driving device according to claim 6,

the urging member is a plate spring mounted to the holding member in a supported or cantilevered manner at both ends.

8. The lens driving device according to claim 6,

the urging member is a helical compression spring.

9. The lens driving device according to any one of claims 1 to 8,

the protruding portion has a spherical shape and is in point contact with the flat portion.

10. The lens driving device according to claim 9,

the projection is constituted by a spherical member.

11. The lens driving device according to any one of claims 1 to 10,

the drive source includes:

a shake correction magnet disposed on either one of the shake correction fixed portion and the shake correction movable portion; and

and a shake correction coil disposed on the other of the shake correction fixed portion and the shake correction movable portion.

12. A camera module, characterized in that,

the camera module includes:

the lens driving device according to any one of claims 1 to 11;

the lens unit attached to the shake correction movable unit; and

and an imaging unit that images the subject image formed by the lens unit.

13. A camera mounting device, which is an information apparatus or a transportation apparatus, is characterized in that,

the camera mounting device includes:

a camera module as in claim 12; and

and an image processing unit that processes image information obtained by the camera module.

Images