WO2019172163A1 - 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, a camera module, and a camera mounting device for shake correction.

Generally, a small camera module is mounted on a mobile terminal such as a smartphone. In such a camera module, an autofocus function (AF: Auto Focus) that automatically performs focusing when shooting a subject and vibration (vibration) that occurs during shooting are optically detected. A lens driving device having a shake correction function (hereinafter referred to as “OIS function”, hereinafter referred to as “OIS function”) that corrects and reduces image distortion is applied (for example, Patent Documents 1 and 2).

A lens driving device having an autofocus function and a shake correction function includes an autofocus drive unit (hereinafter referred to as “AF drive unit”) for moving the lens unit in the optical axis direction, and the lens unit in the optical axis direction. And a shake correction drive section (hereinafter referred to as “OIS drive section”) for swinging in an orthogonal plane. 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 section 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 a shake correction fixing portion (hereinafter referred to as “OIS fixing portion”) via a shake correction support portion (hereinafter referred to as “OIS support portion”). In the lens driving device disclosed in Patent Document 1, an OIS support portion is configured by a suspension wire extending in the optical axis direction, and the OIS movable portion is separated from the OIS fixed portion in the optical axis direction. Is retained.

JP 2013-210550 A JP 2012-177753 A

In recent years, there has been a demand for further miniaturization and weight reduction of lens driving devices in order to realize miniaturization (thinning) and weight reduction of camera-equipped devices such as smartphones. In connection with this, in the wire support type lens driving device as 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 thin. It is planned.

However, as the suspension wire becomes thinner and the wire fixing member becomes thinner, the rigidity of these components decreases. Therefore, the OIS movable part becomes lighter due to changes in the attitude of the lens driving device and displacement of the lens during focusing. There is a possibility that the performance of the AF function or the OIS function is deteriorated due to displacement in a plane orthogonal to the axis or tilting with respect to the optical axis.

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

The lens driving device according to the present invention includes:
A shake correction fixed portion, a shake correction movable portion that can swing in a plane orthogonal to the optical axis, and a shake correction that supports the shake correction movable portion in a state separated from the shake correction fixed portion in the optical axis direction. A lens driving device comprising: a supporting portion for driving; and a driving source for swinging the shake correcting movable portion,
One of the shake correction fixed part and the shake correction movable part has a protruding part 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 comes into contact with the protruding portion,
The projecting portion and the flat portion slide relatively during shake correction,
The protrusion may be elastically displaced in the optical axis direction.

The camera module according to the present invention includes:
The lens driving device;
The lens unit mounted on the shake correction movable unit;
An imaging unit for imaging a subject image formed by the lens unit;
It is characterized by providing.

The camera-mounted device according to the present invention is
A camera-mounted device that is an information device or a transport device,
The above camera module;
An image processing unit that processes image information obtained by the camera module.

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

1A and 1B 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 the camera module. FIG. 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. FIG. 7 is a cross-sectional view of the OIS movable portion. FIG. 8 is a bottom view of the OIS movable portion. 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 illustrating a contact state between the protruding portion and the flat portion. 12A and 12B are diagrams illustrating a displacement state of the protruding portion. FIG. 13 is a diagram illustrating another example of the protruding portion. FIG. 14 is a diagram illustrating another example of the protruding portion. 15A and 15B are diagrams showing a cantilever type protrusion. FIG. 16A and FIG. 16B are diagrams showing an automobile as a camera mounting device on which an in-vehicle camera module is mounted.

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

FIG. 1A and FIG. 1B are diagrams showing a smartphone M (camera mounting device) equipped with a camera module A according to an embodiment of the present invention. 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 a camera module A as a rear camera OC, for example. The camera module A has an AF function and an OIS function, and automatically performs focusing when shooting a subject and optically corrects a shake (vibration) generated during shooting to shoot an image without image blur. be able to.

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, the present embodiment will be described using an orthogonal coordinate system (X, Y, Z). In the drawings to be described later, a common orthogonal coordinate system (X, Y, Z) is also used.

The camera module A is mounted so that the X direction is the up / down direction (or left / right direction), the Y direction is the left / right direction (or up / down direction), and the Z direction is the front / rear direction when shooting is actually performed with the smartphone M. The That is, the Z direction is the optical axis direction, the upper side in the figure is the optical axis direction light receiving side, and the lower side is the optical axis direction imaging side. Further, the X direction and the Y direction orthogonal to the Z axis are referred to as “optical axis orthogonal direction”, and the XY plane is referred to as “optical axis orthogonal surface”.

As shown in FIGS. 2 and 3, the camera module A has an image formed by a lens driving device 1 that realizes an AF function and an OIS function, a lens unit 2 in which a lens is housed in a cylindrical lens barrel, and a lens unit 2. An image pickup unit (not shown) for picking up the captured subject image, a cover 3 covering the whole, and the like are provided. In FIG. 3, the lens unit 2 is omitted.

The cover 3 is a covered rectangular cylinder having a rectangular shape in plan view as viewed from the optical axis direction. 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 on the light receiving side in the optical axis direction (hereinafter referred to as “upper surface”). The lens unit 2 faces the outside through the opening 3a. The cover 3 is fixed to the base 21 (see FIG. 9) of the OIS fixing unit 20 of the lens driving device 1 by, for example, adhesion.

The imaging unit (not shown) is arranged on the optical axis direction imaging side of the lens driving device 1. The imaging unit (not shown) includes, for example, an image sensor substrate and an imaging device mounted on the image sensor substrate. The imaging device is constituted by, for example, a charge-coupled device (CCD) type image sensor, a complementary metal oxide (CMOS) type image sensor, or the like. The imaging element captures the 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 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 (the smartphone M in the present 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.

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

The OIS movable portion 10 has a driving magnet 122 (OIS magnet, see FIG. 6) that constitutes an OIS voice coil motor, and is a portion that swings in the plane orthogonal to the optical axis during shake correction. The OIS fixing portion 20 is a portion that has an OIS coil 221 (see FIG. 9) that constitutes an OIS voice coil motor and supports the OIS movable portion 10 via the OIS support portion 30. In other words, the moving magnet method is adopted for the OIS drive unit of the lens drive device 1. The OIS movable unit 10 includes an AF drive unit having an AF movable unit 11 and an AF fixed unit 12 (see FIG. 6).

The OIS movable unit 10 is disposed apart from the OIS fixing unit 20 on the light receiving side in the optical axis direction, and is connected to the OIS fixing unit 20 by the OIS support unit 30. In the present embodiment, the OIS support portion 30 is composed of four suspension wires extending along the optical axis direction (hereinafter referred to as “suspension wire 30”). Note that the OIS support may be formed of a member other than the suspension wire 30.

One end of the suspension wire 30 (end on the light receiving side in the optical axis direction, upper end) is fixed to the OIS movable portion 10 (in this embodiment, the AF support portion 13 (see FIG. 6)), and the other end (in the optical axis direction). The end on the image forming side) is fixed to the OIS fixing unit 20 (in this embodiment, the base 21 (see FIG. 9)). The OIS movable unit 10 is supported by the suspension wire 30 so as to be swingable in the plane orthogonal to the optical axis. Two of the four suspension wires 30 are used as a power feeding path to the AF coil 112.

FIG. 6 is an exploded perspective view of the OIS movable unit 10. FIG. 7 is a cross-sectional view of the OIS movable unit 10. FIG. 8 is a bottom view of the OIS movable unit 10 (viewed from the optical axis direction imaging side). In FIG. 7, a half section along the X direction or the Y direction passing 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 fixing portion 12, AF support portions 13 and 14, and the like. The AF movable part 11 is arranged to be spaced radially inward with respect to the AF fixing part 12 and is connected to the AF fixing part 12 by AF support parts 13 and 14.

The AF movable portion 11 has an AF coil 112 that constitutes an AF voice coil motor, and is a portion that moves in the optical axis direction during focusing. The AF fixing unit 12 has a driving magnet 122 (AF magnet) that constitutes an AF voice coil motor, and is a portion that supports the AF movable unit 11 via the AF support units 13 and 14. In other words, the moving coil method is employed for the AF driving unit of the lens driving device 1.

The AF movable part 11 is arranged away from the AF fixing part 12 and is connected to the AF fixing part 12 by the AF support parts 13 and 14. In the present embodiment, the AF movable unit 11 is arranged to be separated from the AF fixed unit 12 in the radial direction. 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 fixing portion 12. In the present embodiment, the AF support portion 13 includes two leaf springs 131 and 132 (hereinafter referred to as “upper springs 131 and 132”). The AF support unit 14 is a lower elastic support member that supports the AF movable unit 11 on the optical axis direction imaging side (lower side) with respect to the AF fixing unit 12. In the present embodiment, the AF support portion 14 includes two leaf springs 141 and 142 (hereinafter referred to as “lower springs 141 and 142”).

Further, in the present embodiment, the OIS movable unit 10 is disposed on the image forming side in the optical axis direction so as to partially contact the OIS fixed unit 20 and slides relative to the OIS fixed unit 20 during shake correction. The sliding part 15 is provided.

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

The lens holder 111 is a member that holds the lens unit 2 (see FIG. 2). The lens holder 111 includes a cylindrical lens housing portion 111a, and an upper flange 111b and a lower flange 111c that project 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 AF coil 112 is wound around a portion sandwiched between the upper flange 111b and the lower flange 111c (hereinafter referred to as “coil winding portion”). The coil winding part (reference numeral omitted) has a substantially regular octagonal shape in plan view. As a result, the load acting on the coil winding portion when the AF coil 112 is wound directly becomes uniform, and the strength of the coil winding portion becomes substantially uniform with respect to the center. Can be prevented from being deformed, and the roundness can be maintained.

A lens portion (see FIG. 2) is fixed to the lens housing portion 111a by, for example, adhesion. The lens housing portion 111a preferably has a groove (not shown) to which an adhesive is applied on the inner peripheral surface. In the method of attaching the lens unit 2 to the lens housing unit 111a by screwing, there is a possibility that the suspension wire 30 supporting the OIS movable unit 10 may be damaged. On the other hand, in the present embodiment, since the lens unit 2 is fixed to the inner peripheral surface of the lens housing unit 111a by adhesion, the suspension wire 30 can be prevented from being damaged when the lens unit 2 is attached. Further, when the inner peripheral surface of the lens housing 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 to the upper outer periphery of the lens housing portion 111a. In the present embodiment, the upper spring fixing portion 111d is provided facing the X direction. Further, the lens holder 111 has a lower spring fixing portion 111e for fixing the AF support portion 14 to a surface (hereinafter referred to as "lower surface" or "bottom surface") of the lower flange 111c on the optical axis direction imaging side. Have In the present embodiment, the lower spring fixing portion 111e is provided facing the Y direction.

Further, the lens holder 111 has a binding portion (not shown) to which the end of the AF coil 112 is bound.

In the present embodiment, the lens holder 111 is formed of a molding material made of PAR alloy in which a plurality of resin materials including polyarylate (PAR) or PAR are mixed. In particular, the PAR alloy is preferably a polymer alloy (PAR / PC) made of PAR and polycarbonate (PC). Thereby, since the weld strength is higher than that of a conventional molding material (for example, liquid crystal polymer (LCP: Liquid Crystal Polymer)), toughness and impact resistance can be ensured even if the lens holder 111 is thinned. Therefore, the outer size of the lens driving device 1 can be reduced, and the size and weight can be reduced. 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 multipoint gate. In this case, the gate diameter is preferably 0.3 mm or more. Thereby, the fluidity at the time of molding is improved, so that even when PAR or PAR alloy is used as a molding material, thin-wall molding is possible, and the occurrence of sink marks can be prevented.

The molding material made of PAR or PAR alloy has electrical conductivity, and particularly preferably has a volume resistivity of 10 ⁹ to 10 ¹¹ Ω · cm. For example, conductivity can be easily imparted by mixing carbon nanotubes into existing PAR or PAR alloy. At this time, appropriate conductivity can be imparted by adjusting the content of the carbon nanotube. As a result, charging of the lens holder 111 can be suppressed, and generation of static electricity can be prevented.

The AF coil 112 is an air-core coil that is energized during 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 entangled with the entangled portion (not shown) of the lens holder 111. The AF coil 112 is energized through the AF support portion 13 (upper springs 131 and 132) or the AF support portion 14 (lower springs 141 and 142). The energization current of the AF coil 112 is controlled by, for example, a drive control unit provided on the image sensor substrate.

6 to 8, in the OIS movable unit 10, the AF fixing unit 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 configured by a frame having a substantially octagonal shape in plan view. The magnet holder 121 has an opening 121a in which a portion corresponding to the lens holder 111 is cut out. In the present embodiment, the magnet holder 121 has a magnet holding portion 121 b that holds the driving magnet 122 on the inner peripheral surface at a position corresponding to the four corners of the lens driving device 1. The inner surface of the magnet holding part 121 b is an adhesive surface with the driving magnet 122.

The adhesion surface of the magnet holding part 121b is parallel to the optical axis direction, and the end on the optical axis direction imaging side (the end on the OIS fixing part 20 side in the optical axis direction) is open. This is because the driving magnet 122 is also used as an OIS magnet, and it is magnetically preferable that there is no inclusion between the driving magnet 122 and the OIS coil 221 (see FIG. 9) disposed in the OIS fixing portion 20. . That is, the driving magnet 122 is not fixed physically so as not to fall off 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 corresponding to the four corners of the lens driving device 1 is cut out linearly. The suspension wire 30 is disposed at this portion. In addition, in the magnet holder 121, the part in which the suspension wire 30 is arrange | positioned may be formed so that it may dent in circular arc shape inside radial direction. Thereby, it is possible to avoid the suspension wire 30 and the magnet holder 121 from interfering with each other when the OIS movable unit 10 swings without increasing the outer 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) for fixing the AF support portion 14 on the lower surface. 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 toward the optical axis direction imaging side with respect to the surface to which the AF support portion 13 is attached, and a gap is formed when the AF support portion 13 is attached. It has become.

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

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

In this 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 thermosetting adhesive or an ultraviolet curable adhesive is used. In the driving magnet 122, the surfaces that contact the magnet holding portion 121b (in this embodiment, the side surfaces and the upper surface excluding the surfaces exposed to the inside) are adhesive surfaces.

The driving magnet 122 and the AF coil 112 constitute an AF voice coil motor. In the present 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 drive 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 in contact with the AF fixed portion 12 (magnet holder 121) and the AF movable portion 11 (lens holder 111). ) Is elastically supported on the light receiving side in the optical axis direction. The upper springs 131 and 132 are made of, for example, titanium copper, nickel copper, stainless steel, or the like.

The upper springs 131 and 132 as a whole have a rectangular shape in plan view, that is, a shape equivalent to 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 sheet metal.

The upper springs 131 and 132 are respectively a lens holder fixing part 131a and 132a fixed to the lens holder 111, a magnet holder fixing part 131b and 132b fixed to the magnet holder 121, and a lens holder fixing part 131a and 132a and a magnet holder. Arm portions 131c and 132c for connecting the fixing portions 131b and 132b are provided. 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.

Further, the upper springs 131 and 132 have wire connecting portions 131d and 132d connected to the suspension wire 30, respectively. The wire connecting portions 131d and 132d are connected to the magnet holder fixing portions 131b and 132b via link portions 131e and 132e extending in a zigzag manner.

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 via the upper springs 131 and 132. It is like that.

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

The lower springs 141 and 142 as a whole have a rectangular shape in plan view, that is, a shape equivalent to 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 by, for example, etching a single sheet metal.

The lower springs 141 and 142 are respectively a lens holder fixing portion 141a and 142a fixed to the lens holder 111, a magnet holder fixing portion 141b and 142b fixed to the magnet holder 121, and the lens holder fixing portions 141a and 142a and the magnet holder. Arm portions 141c and 142c for connecting the fixing portions 141b and 142b are provided. 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 includes a holding member 151, a spacer 152, and a ball 153. The sliding portion 15 is disposed on the most optical axis direction imaging side of the OIS movable portion 10 and contacts the OIS fixing portion 20.

In the present embodiment, the ball 153 corresponds to the protruding portion of the present invention. That is, the ball 153 protrudes toward the image forming side in the optical axis direction, and comes into contact with the sliding plate 23 (see FIG. 9, flat portion) of the OIS fixing portion 20. By applying the ball 153 as the projecting portion, a point contact is made with the sliding plate 23 and the contact area becomes small, so that the slidability at the time of shake correction can be ensured. Note that the ball 153 slides instead of rolling on the sliding plate 23 at the time of shake correction.

The holding member 151 is a substantially rectangular frame body in plan view, and is adhered to the spacer 152. The holding member 151 is formed of 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 thin-walled portion 151a is formed at approximately the center in the longitudinal direction of the four sides of the holding member 151. The holding member 151 has a ball accommodating portion 151c that accommodates the ball 153 on the bottom surface side of the thin portion 151a. The ball accommodating portion 151c has a recess (reference numeral omitted) corresponding to the shape of the ball 153 at the center. A ball 153 is disposed in this recess.

The thin-walled portion 151a is thinner than the thick-walled portion 151b and is formed to be elastically deformable in the optical axis direction. In the present embodiment, the upper surface of the thin wall portion 151a is formed to be recessed, and when receiving a force in the optical axis direction, it bends to the light receiving side in the optical axis direction to release the stress. In other words, in the sliding portion 15, the holding member 151 has a beam structure that is supported at both ends. And the ball | bowl 153 which is a protrusion part is arrange | positioned at the thin part 151a which is a beam part. The depression on the upper surface of the thin portion 151a is preferably larger than the gap (see FIG. 12A) formed between the holding member 151 and the sliding plate 23.

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

The ball 153 is formed of a metal material such as zirconia, for example. The ball 153 is disposed in the ball housing portion 151 c of the holding member 151. The ball 153 is interposed between the OIS movable unit 10 and the OIS fixed unit 20. When the OIS movable part 10 and the OIS fixing part 20 are connected by the suspension wire 30, the ball 153 is biased with respect to the OIS fixing part 20 (sliding plate 23). As a result, the ball 153 reliably abuts against the OIS fixing portion 20.

In the present embodiment, the OIS movable unit 10 is supported by four balls 153. Accordingly, the OIS movable unit 10 is held in a stable posture with respect to the OIS fixed unit 20. In addition, from the viewpoint of stabilizing the posture of the OIS movable unit 10, it is preferable that there are three or more balls 153 (projections), that is, the OIS movable unit 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 unit 20.

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

The base 21 is a support member that supports the coil substrate 22 and the sliding plate 23. The base 21 is a rectangular member in plan view, and has a substantially circular opening 21a at the center. A terminal fitting 211 is embedded in the base 21. The terminal fitting 211 is formed integrally with the base 21 by, for example, insert molding. In the present embodiment, the terminal fitting 211 is 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.

In the present embodiment, the base 21 is formed of a molding material made of PAR alloy (for example, PAR / PC) in which a plurality of resin materials including polyarylate (PAR) or PAR are mixed, like the lens holder 111. Yes. Thereby, since the weld strength is increased, toughness and impact resistance can be ensured even if the base 21 is thinned. Therefore, the outer size of the lens driving device 1 can be reduced, and the size and height can be reduced.

The base 21 is preferably formed by injection molding of a multipoint gate. In this case, the gate diameter is preferably 0.3 mm or more. Thereby, since the fluidity at the time of molding is improved, thin-wall molding is possible even when PAR or PAR alloy is used as a molding material, and the occurrence of sink marks can be prevented.

The molding material made of PAR or PAR alloy has electrical conductivity, and particularly preferably has a volume resistivity of 10 ⁹ to 10 ¹¹ Ω · cm. For example, conductivity can be imparted by mixing carbon nanotubes into existing PAR or PAR alloy. At this time, appropriate conductivity can be imparted by adjusting the content of the carbon nanotube. Thereby, since charging of the base 21 can be suppressed, generation of static electricity can be prevented.

The base 21 has, on the periphery of the opening 21a, a coil substrate fixing portion 21b where the coil substrate 22 is arranged and a sliding plate fixing portion 21c where the sliding plate 23 is arranged. 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 located on the light receiving side in the optical axis direction 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 rectangular substrate in plan view like the base 21, and has a circular opening 22a in the center. The coil substrate 22 is, for example, a multilayer printed wiring board in which a plurality of unit layers including a conductor layer and an insulating layer (not shown) are stacked. 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 formed on the coil substrate 22.

In the OIS fixing portion 20, the sliding plate 23 is a substantially rectangular frame body in plan view, like the holding member 151. The sliding plate 23 is made of a metal material such as a copper alloy, for example. In the present embodiment, the sliding 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 comes into contact with the ball 153. The approximately center 23 a in the longitudinal direction of the four sides of the sliding plate 23 serves as a contact portion with the ball 153. The width of the sliding plate 23 is appropriately set according to the swing range of the OIS movable unit 10.

In the present embodiment, the sliding surface of the sliding plate 23 is subjected to a low friction process. For the low friction treatment, for example, a Ni plating treatment in which PTFE (Polytetrafluoroethylene) is dispersed can be applied. Thereby, since the frictional force generated when the ball 153 slides on the sliding plate 23 is reduced, the slidability at the time of shake correction can be ensured.

In this embodiment, the base 21, the coil substrate 22, and the sliding plate 23 are bonded by an elastic epoxy resin material. 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 increased, so that the base 21, the coil substrate 22 and the sliding plate are secured while ensuring the desired drop impact resistance. The moving plate 23 can be 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 portion exposed from the notches at the four corners). When the OIS movable portion 10 and the OIS fixing portion 20 are connected by the suspension wire 30, the ball 153 is biased against the OIS fixing portion 20 (sliding plate 23).

The lens driving device 1 includes a Z position detection unit that detects a position of the AF movable unit 11 in the optical axis direction and / or an XY position detection unit that detects a position of the OIS movable unit 10 in the plane orthogonal to the optical axis. Also good. For example, the Z position detection unit and the XY position detection unit can be configured 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 unit, for example, a detection magnet is disposed in the AF movable unit 11 (for example, the lens holder 111), and a Hall element is disposed in the AF fixing unit 12 (for example, the magnet holder 121). When the AF movable unit 11 moves in the optical axis direction, the magnetic field generated by the position detection magnet changes. By detecting this change in the magnetic field with a Hall element, the position of the AF movable portion 11 in the optical axis direction is detected. Note that a control IC with a built-in Hall element may be disposed in the AF fixing unit 12 so that the energization current of the AF coil 112 is controlled by the control IC.

XY position detection unit has two sets of position detection magnets and Hall elements. The drive magnet 122 may be used as the position detection magnet. In the case of the XY position detection unit, for example, a detection magnet is disposed on the OIS movable unit 10 (for example, the magnet holder 121), and a Hall element is disposed on the OIS fixing unit 20 (for example, the coil substrate 22). When the OIS movable unit 10 moves in the plane orthogonal to the optical axis, the magnetic field generated by the position detection magnet changes. By detecting this change in magnetic field with two Hall elements, the position of the OIS movable unit 10 in the plane orthogonal to the optical axis is detected.

Since the response performance is improved by performing the closed loop control based on the hall output, the AF operation or the OIS operation can be speeded up.

When the lens drive device 1 performs shake correction, the OIS coil 221 is energized. Specifically, in the OIS drive unit, the energization current of the OIS coil 221 is 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 out. Be controlled.

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

When the lens driving device 1 performs automatic focusing, the AF coil 112 is energized. When the AF coil 112 is energized, 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 through 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 voice coil motor for AF, and the AF movable portion 11 having the AF coil 112 moves in the optical axis direction, and focusing is performed.

When no power is applied without focusing, the AF movable unit 11 is suspended (neutral point) between the infinity position and the macro position 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 positioned with respect to the AF fixed portion 12 (magnet holder 121) by the upper springs 131 and 132 and the lower springs 141 and 142. It is elastically supported so that it can be displaced on both sides in the Z direction.

11A and 11B are diagrams showing a contact state between the ball 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 shows an enlarged view of the broken line part of FIG. 11A.

11A and 11B, in the lens driving device 1, since the ball 153 is biased toward the OIS fixing portion 20, the ball 153 and the sliding plate 23 come into contact with each other. Since the ball 153 protrudes from the bottom surface of the holding member 151 toward the optical axis direction imaging side, a gap is formed between the bottom surface of the holding member 151 and the top surface of the sliding plate 23. When the OIS movable unit 10 swings in the plane orthogonal to the optical axis during shake correction, the ball 153 slides on the sliding plate 23.

In the present embodiment, the surface of the sliding plate 23 is subjected to a low friction process. Further, the ball 153 and the sliding plate 23 are in contact with each other, and the contact area is extremely small. Therefore, although the OIS movable part 10 is in partial contact with the OIS fixed part 20, the swinging of the OIS movable part 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 due to a drop impact, the force concentrates on the ball 153. Accordingly, the thin portion 151a of the holding member 151 is bent, and the ball 153 is displaced to the light receiving side in the optical axis direction (see FIG. 12B). On the other hand, the ball 153 returns to the original state when the force in the optical axis direction is released (see FIG. 12A). That is, the ball 153 can be elastically displaced in the optical axis direction.

Thus, since the force in the optical axis direction due to the drop impact is absorbed by the sliding portion 15, the force transmitted to the suspension wire 30, the AF support portions 13, 14, etc. becomes small. Accordingly, 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 to reduce the thickness of the AF support portions 13 and 14.

As described above, the lens driving device 1 includes the OIS fixing unit 20 (shake correction fixing unit), the OIS movable unit 10 (shake correction moving unit) that can swing in a plane orthogonal to the optical axis, and the OIS fixing unit 20. On the other hand, a suspension wire 30 (shake correction support portion) that supports the OIS movable portion 10 in a state of being separated in the optical axis direction, and a voice coil motor (drive source) that swings the OIS movable portion 10 are provided.
In the lens driving device 1, the OIS movable unit 10 (one of the shake correction fixed unit and the shake correction movable unit) has a ball 153 (projection) that projects in the optical axis direction. The OIS fixing portion (the other of the shake correction fixing portion and the shake correction movable portion) has a sliding plate 23 (flat portion) that comes into contact with the ball 153. The ball 153 and the sliding plate 23 slide relative to each other during shake correction. The ball 153 can be elastically displaced in the optical axis direction.

According to the lens driving device 1, since the ball 153 is interposed between the OIS movable unit 10 and the OIS fixed unit 20, and the OIS movable unit 10 is supported by the ball 153, it is held in a stable posture. As a result, even if the suspension wire 30 is thinned and the AF support portions 13 and 14 (wire fixing members) are thinned, the OIS movable portion 10 is displaced in the plane orthogonal to the optical axis even if the rigidity thereof decreases. Or tilting with respect to the optical axis to prevent the performance of the AF function or the OIS function from deteriorating.
Further, since the ball 153 is elastically displaceably held and the force acting upon the 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, it is possible to reduce the size and weight and improve the reliability.

As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above-described embodiment, and can be changed without departing from the gist thereof.

For example, in the embodiment, the case where the holding member 151 is bent to absorb the drop impact has been described. However, when the ball 153 is displaced in the optical axis direction between the holding member 151 and the ball 153, a restoring force is exhibited. An urging member may be interposed. For example, a leaf 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 leaf spring 154 bends when receiving a force in the optical axis direction from the ball 153.

Further, a compression coil spring may be arranged as the urging member. When a compression coil spring is applied, there may be no gap between the holding member 151 and the spacer 152.

For example, in the embodiment, the case where the holding member 151 has a both-end supported beam structure has been described, but a cantilever beam structure may be applied as shown in FIG. In this case, the holding member 151 may be composed of a plurality of members (see FIG. 15A) or a single member (see FIG. 15B).

Further, the protrusions may be formed integrally with the holding member 151. In this case, it is preferable that the tip portion of the protruding portion (the portion in contact with the sliding plate 23) has a spherical shape. Thereby, the slidability of the OIS movable part 10 is securable similarly to the case where the ball | bowl 153 is arrange | positioned.

In the embodiment, the sliding 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 a metal, it is preferably provided separately from the base 21 and the coil substrate 22.

In the embodiment, the OIS movable part 10 is provided with a protrusion and the OIS fixed part 20 is provided with a flat part. However, the OIS movable part 10 is provided with a flat part and the OIS fixed part 20 is provided with a protrusion. May be provided. Further, not only the flat portion but also the protruding portion may be subjected to the low friction treatment.

In the embodiment, the smartphone M, which is a camera-equipped mobile terminal, has been described as an example of a camera mounting device including the camera module A. However, the present invention processes image information obtained by the camera module and the camera module. The present invention can be applied to a camera mounting device having an image processing unit. The camera mounting device includes information equipment and transportation equipment. The information equipment includes, for example, a mobile phone with a camera, a notebook computer, a tablet terminal, a portable game machine, a web camera, and a vehicle-mounted device with a camera (for example, a back monitor device or a drive recorder device). Moreover, transportation equipment includes a motor vehicle, for example.

FIG. 16A and FIG. 16B are views showing a vehicle V as a camera mounting 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. The automobile V is equipped with the camera module A described in the embodiment as an in-vehicle camera module VC. As shown in FIGS. 16A and 16B, the in-vehicle camera module VC is attached to the windshield, for example, facing forward or attached to the rear gate facing backward. This in-vehicle camera module VC is used for a back monitor, a drive recorder, a collision avoidance control, an automatic driving control, and the like.

Further, the configurations of the AF coil, the AF magnet, the OIS coil, and the OIS magnet are not limited to those shown in the embodiment. For example, the driving magnet that serves both as the AF magnet and the OIS magnet may have a rectangular parallelepiped shape and may be disposed around the AF coil so that the magnetization direction coincides with the radial direction. Also, a flat AF coil is placed around the lens so that the coil surface is parallel to the optical axis direction, a rectangular parallelepiped drive magnet, and the magnetization direction intersects the coil surface of the AF coil. You may arrange so that.

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

In the embodiment, the lens unit 2 is arranged in the OIS movable unit 10, the imaging unit is arranged in the OIS fixing unit 20, and so-called optical correction is performed by the lens unit 2 swinging with respect to the imaging unit. Although the lens driving device 1 having the shake correction function has been described, in the present invention, the lens unit is disposed in the OIS fixed unit, the imaging unit is disposed in the OIS movable unit, and the imaging unit swings with respect to the lens unit. The present invention can also be applied to a lens driving device having a so-called sensor shift type shake correction function that performs shake correction by the above-described method.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The disclosure of the specification, drawings and abstract contained in the Japanese application of Japanese Patent Application No. 2018-040487 filed on March 7, 2018 is incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 Lens drive device 2 Lens part 3 Cover 10 OIS movable part (shake correction movable part)
11 AF movable portion 12 AF fixing portion 13, 14 AF support portion 15 sliding portion 20 OIS fixing portion (shake correction fixing portion)
21 Base 22 Coil substrate 23 Sliding plate (flat part)
30 OIS support part 111 Lens holder 112 AF coil 121 Magnet holder 122 Driving magnet 151 Holding member 152 Spacer 153 Ball (protrusion part)
221 Coil for OIS M Smartphone A Camera module

Claims (13)

A shake correction fixed portion, a shake correction movable portion that can swing in a plane orthogonal to the optical axis, and a shake correction that supports the shake correction movable portion in a state separated from the shake correction fixed portion in the optical axis direction. A lens driving device comprising: a supporting portion for driving; and a driving source for swinging the shake correcting movable portion,
One of the shake correction fixed part and the shake correction movable part has a protruding part 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 comes into contact with the protruding portion,
The projecting portion and the flat portion slide relatively during shake correction,
The lens driving device according to claim 1, wherein the protruding portion is elastically displaceable in the optical axis direction. 2. The lens driving device according to claim 1, wherein the protruding portion is biased with respect to the flat portion. 3. The lens driving device according to claim 1, wherein at least one sliding surface of the projecting portion and the flat portion is subjected to a low friction process. 4. The lens driving device according to claim 3, wherein the low friction treatment is a Ni plating treatment in which PTFE particles are dispersed. A holding member for holding the protruding portion;
The holding member has a beam portion that is supported at both ends or cantilevered,
The lens driving device according to claim 1, wherein the protruding portion is disposed on the beam portion. A holding member for holding the protruding portion;
An urging member interposed between the holding member and the protrusion,
5. The lens driving device according to claim 1, wherein the biasing member exhibits a restoring force when the projecting portion is displaced in the optical axis direction. 6. The lens driving device according to claim 6, wherein the urging member is a leaf spring attached to the holding member by a both-end support type or a cantilever type. The lens driving device according to claim 6, wherein the biasing member is a compression coil spring. 9. The lens driving device according to claim 1, wherein the protruding portion has a spherical shape and makes point contact with the flat portion. The lens driving device according to claim 9, wherein the protruding portion is formed of a ball member. The drive source is
A shake correction magnet disposed on one of the shake correction fixed portion and the shake correction movable portion;
A shake correction coil disposed on the other of the shake correction fixed portion and the shake correction movable portion;
The lens driving device according to claim 1, further comprising: The lens driving device according to any one of claims 1 to 11,
The lens unit mounted on the shake correction movable unit;
An imaging unit for imaging a subject image formed by the lens unit;
A camera module comprising: A camera-mounted device that is an information device or a transport device,
The camera module according to claim 12,
An apparatus for mounting a camera, comprising: an image processing unit that processes image information obtained by the camera module.

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