TWI802659B - Lens driving device, camera module, and camera mounting device - Google Patents

Abstract

The present invention provides 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 includes: a shake correction fixed part; a shake correction movable part that can swing in a plane perpendicular to the optical axis; a shake correction support part that aligns the shake correction movable part with respect to the shake correction fixed part in the direction of the optical axis The separated state is supported; and the drive source causes the shake correction movable part to oscillate. One of the shake correction fixed part and the shake correction movable part has a protruding part protruding in the direction of the optical axis, and the other has a flat part abutting on the protruding part. The protruding part and the flat part slide relative to each other during shake correction. The protrusion is elastically displaceable toward the optical axis.

Description

Lens driving device, camera module, and camera mounting device

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

Usually, a portable terminal such as a smart phone (smartphone) is equipped with a small camera module. A lens drive device with an autofocus function and a shake correction function is applied to such a camera module. The autofocus function (hereinafter referred to as "AF function", AF: Auto Focus) is to automatically focus when shooting a subject , the shake correction function (hereinafter referred to as "OIS function", OIS: Optical Image Stabilization) is to optically correct the shake (vibration) generated during shooting to reduce image disturbance (for example, patent document 1, patent document 2) .

A lens drive 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 toward the optical axis; and a shake correction drive unit (hereinafter referred to as This is referred to as the "drive unit for OIS") and is used to oscillate the lens unit in a plane perpendicular to the optical axis direction. In Patent Document 1 and Patent Document 2, a voice coil motor (Voice Coil Motor, VCM) is applied to an AF drive unit and an OIS drive unit.

The drive unit for OIS has a shake correction movable part (hereinafter referred to as "OIS movable part") that oscillates in a plane perpendicular to the optical axis direction during shake correction. The OIS movable unit is supported by the shake correction fixing unit (hereinafter referred to as “OIS fixing unit”) via the shake correction supporting unit (hereinafter referred to as “OIS supporting unit”). In the lens drive device disclosed in Patent Document 1, the OIS support portion is formed 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. Keep. [Prior art literature] [Patent Document]

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

[Problem to be Solved by the Invention]

In recent years, in order to realize the miniaturization (thinning) and weight reduction of camera-mounted devices such as smartphones, further miniaturization and weight reduction of lens driving devices have been demanded. Along with this, in the lens driving device of the wire support method disclosed in Patent Document 1, the thinning of the suspension wire and the thinning of the member for fixing the suspension wire (hereinafter referred to as "wire fixing member") are required. walled.

However, when the thinning of the suspension wire and the thinning of the wire fixing member are promoted, since the rigidity of the member is reduced, the OIS movable part may be affected by a change in the posture of the lens driving device or a change in the lens during focus (focus). Displacement, etc., and there is a concern that the performance of the AF function or the OIS function may decrease due to displacement in a plane perpendicular to the optical axis, or inclination 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 capable of achieving miniaturization and weight reduction and improving reliability. [Means to solve the problem]

The lens driving device of the present invention comprises: a shake correction fixed part; a shake correction movable part capable of swinging in a plane perpendicular to the optical axis; a shake correction support part that separates the shake correction movable part from the shake correction fixed part in the direction of the optical axis is supported by an open state; and a drive source that causes the shake correction movable part to oscillate, wherein One of the shake correction fixed part and the shake correction movable part has a protruding part protruding in the direction of the optical axis, The other of the shake correction fixed part and the shake correction movable part has a flat part abutting on the protruding part, The protruding portion and the flat portion slide relative to each other during shake correction, The protruding portion is elastically displaceable in the direction of the optical axis.

The camera module of the present invention is characterized in that it comprises: The lens driving device; a lens unit mounted on the shake correction movable unit; and The imaging unit captures a subject image formed by the lens unit.

The camera-mounted device of the present invention is A camera-mounted device as an information machine or a transport machine, comprising: the camera module; and The image processing unit processes the image information obtained by the camera module. [Effect of the invention]

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

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

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

For example, the smart phone M is equipped with a camera module A as a rear camera OC. The camera module A has an AF function and an OIS function, which can automatically focus when shooting a subject, and can optically correct the shaking (vibration) generated during shooting to take images without image blur.

FIG. 2 is a perspective view of the appearance of the camera module A. As shown in FIG. FIG. 3 is an exploded perspective view of the camera module A. FIG. As shown in FIG. 2 and FIG. 3 , in this embodiment, an orthogonal coordinate system (X, Y, Z) will be used for description. Also in the drawings described later, the common orthogonal coordinate system (X, Y, Z) is used to represent.

When actually shooting with the smartphone M, 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. 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. Also, the X direction and the Y direction perpendicular to the Z axis are referred to as "optical axis orthogonal directions", and the XY plane is referred to as "optical axis orthogonal surface".

As shown in Figure 2 and Figure 3, the camera module A includes: a lens driving device 1, which realizes the AF function and the OIS function; the lens part 2, which is formed by housing a lens in a cylindrical lens barrel (lens barrel); The part (not shown in the figure) captures the subject image formed by the lens part 2; and the cover body 3 covers the whole. In addition, in FIG. 3, the lens part 2 is omitted.

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

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

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

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

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

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

One end (the light-receiving side end in the optical axis direction, the upper end) of the suspension wire 30 is fixed to the OIS movable part 10 (in this embodiment, the AF support part 13 (refer to FIG. 6 )), and the other end (the imaging side end in the optical axis direction) part) is fixed to the OIS fixing part 20 (in this embodiment, the base 21 (see FIG. 9 )). The OIS movable unit 10 is supported swingably in a plane perpendicular to the optical axis by the suspension wire 30 . Two of the four suspension wires 30 are used as feed paths 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 part 10 (a view viewed from the imaging side in the optical axis direction). 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 unit 10 includes an AF movable unit 11 , an AF fixed unit 12 , an AF supporting unit 13 , an AF supporting unit 14 , and the like. The AF movable part 11 is arranged radially inwardly apart from the AF fixed part 12 , and is connected to the AF fixed part 12 via the AF support part 13 and the AF support part 14 .

The AF movable part 11 has an AF coil 112 constituting an AF voice coil motor, and is a part that moves in the direction of the optical axis when focusing. The AF fixed unit 12 has a driving magnet 122 (AF magnet) constituting an AF voice coil motor, and is a part that supports the AF movable unit 11 via the AF supporting unit 13 and the AF supporting unit 14 . That is, the AF driving unit of the lens driving device 1 adopts a moving coil type.

The AF movable unit 11 is arranged at a distance from the AF fixed unit 12 , and is connected to the AF fixed unit 12 via the AF support unit 13 and the AF support unit 14 . In the present embodiment, the AF movable section 11 is arranged radially apart from the AF fixed section 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 unit 13 is constituted by two leaf springs 131 and 132 (hereinafter referred to as "upper spring 131 and upper spring 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 constituted by two leaf springs 141 and 142 (hereinafter referred to as "lower spring 141 and lower spring 142").

In addition, in this embodiment, the OIS movable part 10 has a sliding part 15 on the imaging side in the optical axis direction, and the sliding part 15 is arranged in a manner to be in partial contact with the OIS fixing part 20, and performs contact with the OIS fixing part 20 at the time of shake correction. relatively sliding.

As shown in FIGS. 6 to 8 , in the OIS movable unit 10 , the AF movable unit 11 has a lens holder (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 has a cylindrical lens housing portion 111 a, an upper flange 111 b and a lower flange 111 c protruding radially outward from the lens housing portion 111 a. 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 portion (symbols are omitted) has a substantially regular octagonal shape in plan view. Thereby, since the load acting on the coil winding portion is uniform when the AF coil 112 is directly wound, and the strength of the coil winding portion is also approximately uniform with respect to the center, deformation of the opening of the lens housing portion 111a can be prevented, thereby enabling Maintain roundness.

The lens part is fixed to the lens housing part 111a by bonding, for example (refer FIG. 2). The lens housing portion 111a preferably has a groove (not shown) for applying an adhesive on the inner peripheral surface. In the method of attaching the lens unit 2 to the lens accommodating unit 111 a by screwing, there is a possibility of damage to the suspension wire 30 supporting the OIS movable unit 10 . On the other hand, in this embodiment, since the lens part 2 is fixed to the inner peripheral surface of the lens accommodating part 111a by bonding, it can prevent that the suspension wire 30 is damaged when the lens part 2 is attached. In addition, when there is a groove on the inner peripheral surface of the lens housing part 111a, an appropriate amount of adhesive can be held by the groove, so that the bonding strength between the lens holder 111 and the lens part 2 is improved.

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

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

In the present embodiment, the lens holder 111 is formed of polyarylate (PAR) or a molding material including a PAR blend obtained by mixing a plurality of resin materials including PAR. In particular, the PAR blend is preferably a polymer alloy (PAR/PC) comprising PAR and polycarbonate (PC). Thereby, welding strength is improved compared with the conventional molding material (for example, liquid crystal polymer (LCP: liquid crystal polymer)), Therefore Toughness and impact resistance can be ensured even if the lens holder 111 is thinned. Therefore, the external dimension of the lens driving device 1 can be reduced, and the size and weight can be reduced. Furthermore, the lens holder 111 may also be formed of liquid crystal polymer or the like.

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

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

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

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

The magnet holder 121 is a member that holds the driving magnet 122 . In this embodiment, the magnet holder 121 is comprised by the frame body which has a substantially octagonal shape in planar view. The magnet holder 121 has a partially cut-off opening 121 a corresponding to the lens holder 111 . In the present embodiment, the magnet holder 121 has a magnet holder 121b for holding the driving magnet 122 on the inner peripheral surface at positions corresponding to the four corners of the lens driving device 1 . The inner surface of the magnet holding portion 121 b serves as a bonding surface with the driving magnet 122 .

The bonding surface of the magnet holding part 121b is parallel to the optical axis direction, and the imaging-side end in the optical axis direction (the end on the OIS fixing part 20 side in the optical axis direction) is open. The driving magnet 122 is also used as a magnet for OIS, and is magnetically more preferable because there is no intervening object between the coils 221 for OIS (see FIG. 9 ) arranged in the OIS fixing part 20 . That is, the driving magnet 122 is not physically fixed by the shape of the magnet holding portion 121b so as not to fall off, but is fixed only by the adhesive force of the adhesive.

The outer peripheral surface of the magnet holder 121 at the positions corresponding to the four corners of the lens driving device 1 is linearly cut away. Suspension wires 30 are arranged in this part. In addition, in the magnet holder 121 , a portion where the suspension wire 30 is disposed may be formed to be recessed radially inward in an arc shape. Thereby, without enlarging the outer shape of the lens driving device 1 , it is possible to avoid interference between the suspension wire 30 and the magnet holder 121 when the OIS movable part 10 swings.

The magnet holder 121 has an upper spring fixing part 121d for fixing the AF support part 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 part (not shown) for fixing the AF support part 14 on the lower surface. In this embodiment, like the upper spring fixing part 121d, lower spring fixing parts (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 imaging side in the optical axis direction than the surface on which the AF holder 13 is attached, and a gap is formed when the AF holder 13 is attached.

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

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 part of the magnet holder 121 can be utilized effectively. The driving magnet 122 is magnetized to form a magnetic field that crosses the AF coil 112 in the radial direction. In the present embodiment, the driving magnet 122 is magnetized such that the inner peripheral side has an N pole and the outer peripheral side has an S pole. In addition, the surface of the driving magnet 122 is covered with a metal film such as nickel (Ni) plating to improve corrosion resistance.

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

A voice coil motor for AF is constituted by the driving magnet 122 and the coil 112 for AF. In the present embodiment, the drive magnet 122 also serves as an AF magnet and an OIS magnet. Furthermore, 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 part 10, the AF support part 13 (upper spring 131, upper spring 132) holds the AF movable part 11 (lens holder 111) relative to the AF fixed part 12 (magnet holder). Tool 121) is elastically supported on the light-receiving side in the direction of the optical axis. The upper spring 131 and the upper spring 132 are made of titanium copper, nickel copper, stainless steel, etc., for example.

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

The upper spring 131 and the upper spring 132 respectively have: a lens holder fixing part 131a fixed to the lens holder 111, a lens holder fixing part 132a, a magnet holder fixing part 131b fixed to the magnet holder 121, and a magnet holder fixing part. 132b, and arm portions 131c and 132c for connecting the lens holder fixing portion 131a, the lens holder fixing portion 132a, the magnet holder fixing portion 131b, and the magnet holder fixing portion 132b. The arm part 131c and the arm part 132c are formed in a curved shape, and elastically deform when the AF movable part 11 moves in the direction of the optical axis.

Moreover, the upper spring 131 and the upper spring 132 respectively have a wire connection part 131d and a wire connection part 132d connected to the suspension wire 30 . The wire connection part 131d and the wire connection part 132d are connected to the magnet holder fixing part 131b and the magnet holder fixing part 132b via the connection (link) part 131e and the connection part 132e extending zigzag.

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

As shown in FIGS. 6 to 8, in the OIS movable part 10, the AF support part 14 (lower spring 141, lower spring 142) holds the AF movable part 11 (lens holder 111) relative to the AF fixed part 12 (magnet holder). Tool 121) provides elastic support on the imaging side in the direction of the optical axis. The lower spring 141 and the lower spring 142 are made of, for example, titanium copper, nickel copper, stainless steel or the like.

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

The lower spring 141 and the lower spring 142 respectively have a lens holder fixing part 141a fixed to the lens holder 111, a lens holder fixing part 142a, a magnet holder fixing part 141b fixed to the magnet holder 121, and a magnet holder fixing part. 142b, and arm portions 141c and 142c for connecting the lens holder fixing portion 141a, the lens holder fixing portion 142a, the magnet holder fixing portion 141b, and the magnet holder fixing portion 142b. The arm part 141c and the arm part 142c are formed in a curved shape, and elastically deform when the AF movable part 11 moves in the direction of the optical axis.

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

In this embodiment, the ball 153 corresponds to the protruding portion of the present invention. That is, the ball 153 protrudes toward the imaging side in the optical axis direction, and contacts the slide plate 23 (see FIG. 9 , flat portion) of the OIS fixing portion 20 . By using the balls 153 as protrusions, point contact with the slide plate 23 reduces the contact area, thereby ensuring slidability at the time of shake correction. Furthermore, the ball 153 does not rotate on the slide plate 23 but slides during shake correction.

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

The holding member 151 has a thick portion 151b and a thin portion 151a. In the present embodiment, a thin portion 151 a is formed approximately at 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 for accommodating the ball 153 on the bottom surface side of the thin portion 151a. The ball housing part 151c has a dimple (symbol omitted) corresponding to the shape of the ball 153 at the center. Balls 153 are disposed in the recess.

The thin portion 151a is formed thinner than the thick portion 151b, and is elastically deformable in the direction of the optical axis. In the present embodiment, the upper surface of the thin portion 151a is formed to be depressed, and when a force in the direction of the optical axis is received, it bends toward the light-receiving side in the direction of the optical axis to release the stress. That is, in the slider 15 , the holding member 151 has a beam structure supported at both ends. And the ball 153 which is a protruding part is arrange|positioned in the thin-walled part 151a which is a beam part. The dimples on the upper surface of the thin portion 151 a are preferably larger than the gap formed between the holding member 151 and the slide plate 23 (see FIG. 12(A) ).

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

The ball 153 is formed of a metal material such as zirconia, for example. The balls 153 are arranged in the ball housing portion 151 c of the holding member 151 . The ball 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 ball 153 will be in the state which urges the OIS fixed part 20 (slide plate 23). Thereby, the ball 153 is surely in contact with the OIS fixing part 20 .

In this embodiment, the OIS movable part 10 is supported by four balls 153 . Thereby, the OIS movable part 10 is held in a stable posture with respect to the OIS fixed part 20 . Furthermore, from the standpoint of stabilizing the posture of the OIS movable part 10, it is preferable that there are three or more balls 153 (protruding parts), that is, the OIS movable part 10 is preferably supported by three or more points.

FIG. 9 is an exploded perspective view of the OIS fixing unit 20 . FIG. 10 is a plan view of the OIS fixing unit 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 supporting member that supports the coil substrate 22 and the slide plate 23 . The base 21 is a rectangular member in plan view, and has a substantially circular opening 21 a in the center. A terminal metal fitting 211 is embedded in the base 21 . The terminal metal fitting 211 is integrally formed with the base 21 by, for example, insert molding. In this embodiment, the terminal metal fittings 211 are exposed from four corners of the base 21 . The terminal metal fitting 211 is soldered to the power supply terminal (not shown) of the coil substrate 22 and the suspension wire 30 to be physically and electrically connected.

In this embodiment, like the lens holder 111, the base 21 is formed of polyarylate (PAR) or a PAR blend (for example, PAR/PC) obtained by mixing various resin materials containing PAR. material formed. Thereby, since the welding strength improves, toughness and impact resistance can be ensured even if the base 21 is thinned. Therefore, the external dimension of the lens driving device 1 can be reduced, and miniaturization and low profile can be achieved.

Also, the base 21 is preferably formed by injection molding of a multi-gate. In this case, the gate diameter is preferably 0.3 mm or more. Thereby, since the fluidity at the time of molding becomes favorable, thin-wall molding is possible even when PAR or a PAR blend is used as a molding material, and generation of sink marks can be prevented.

PAR or a molding material comprising a PAR blend has electrical conductivity, and in particular, preferably has a volume resistivity of 10 ⁹ to 10 ¹¹ Ω·cm. For example, conductivity can be imparted by incorporation of carbon nanotubes into existing PAR or PAR blends. In this case, appropriate conductivity can be imparted by adjusting the content of carbon nanotubes. Thereby, since charging of the susceptor 21 can be suppressed, 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 slide plate fixing portion 21c on which the slide plate 23 is arranged on the periphery of the opening 21a. The coil substrate fixing portion 21b is formed to be more concave than the sliding plate fixing portion 21c on the inner peripheral side of the sliding plate fixing portion 21c. The upper surface of the slide plate 23 disposed on the slide 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 disposed on the coil substrate fixing portion 21b. Thereby, a gap is reliably formed between the coil substrate 22 and the OIS movable part 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 similar to the base 21 and has a circular opening 22 a in the center. The coil substrate 22 is, for example, a multilayer printed wiring board in which unit layers including conductor layers and insulating layers (not shown) are laminated. In the coil substrate 22 , for example, an OIS coil 221 , external terminals (not shown), and a conductor pattern (not shown) including a power line connecting the external terminal and the OIS coil 221 are integrally embedded.

In the OIS fixing unit 20 , the slide plate 23 is a substantially rectangular frame in plan view, similarly to the holding member 151 . The slide plate 23 is formed of a metal material such as copper alloy, for example. In this 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 balls 153 . The approximate longitudinal center 23 a of the four sides of the slide plate 23 forms a contact portion with the ball 153 . The width of the slide plate 23 is appropriately set according to the swing range of the OIS movable unit 10 .

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

In the present embodiment, the base 21, the coil substrate 22, and the sliding plate 23 are bonded by an elastic epoxy resin material. Since the mechanical strength of the OIS fixing part 20 is improved by integrating the base 21, the coil substrate 22, and the slide plate 23 by bonding, the base 21, the coil substrate and 22, and slide plate 23 thin-walled.

In the lens driving device 1 , one end of the suspension wire 30 is physically and electrically connected to the wire connection portion 131 d and the wire connection portion 132 d of the upper spring 131 and the upper spring 132 , respectively. The other end of the suspension wire 30 is physically and electrically connected to the terminal metal fitting 211 (the part exposed from the cutouts at the four corners) of the base 21 . When the OIS movable part 10 and the OIS fixed part 20 are connected by the suspension wire 30, the ball 153 will be in the state which urges the OIS fixed part 20 (slide plate 23).

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

In the case of the Z position detection unit, for example, a detection magnet is disposed on the AF movable unit 11 (for example, the lens holder 111 ), and a Hall element is disposed on the AF fixed unit 12 (for example, the magnet holder 121 ). When the AF movable section 11 moves in the direction of the optical axis, the magnetic field caused by the position detection magnet changes. The position of the AF movable section 11 in the optical axis direction is detected by detecting the change in the magnetic field with the Hall element. Furthermore, a control integrated circuit (integrated circuit, IC) with a built-in Hall element may also be arranged in the AF fixing part 12, and the energizing current of the AF coil 112 is 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 be utilized. In the case of an XY position detection unit, for example, a detection magnet is arranged on the OIS movable unit 10 (for example, the magnet holder 121 ), and a Hall element is arranged on the OIS fixed unit 20 (for example, the coil substrate 22 ). When the OIS movable part 10 moves in the plane perpendicular to the optical axis, the magnetic field caused by the position detection magnet changes. The position of the OIS movable part 10 in the plane perpendicular to the optical axis is detected by detecting the change of the magnetic field with the two Hall elements.

By performing closed loop control based on the Hall output, the response performance is improved, and thus the speed of the AF operation or the OIS operation can be increased.

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

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

When performing autofocus in the lens driving device 1 , the AF coil 112 is energized. When the AF coil 112 is energized, Lorentz force is generated in the AF coil 112 by the interaction between the magnetic field of the drive magnet 122 and the current flowing through the AF coil 112 . The direction of the Lorentz force is the direction (Z direction) perpendicular to the direction of the magnetic field and the direction of the current flowing through the AF coil 112 . Since the driving magnet 122 is fixed, a reaction force acts on the AF coil 112 . The reaction force becomes the driving force of the AF voice coil motor, and the AF movable part 11 having the AF coil 112 moves in the direction of the optical axis to perform focusing.

Furthermore, when there is no power supply for focusing, the AF movable part 11 is suspended between the infinity position and the macro position by the upper spring 131, the upper spring 132, the lower spring 141, and the lower spring 142. state (neutral point). That is, in the OIS movable part 10, the AF movable part 11 (lens holder 111) is fixed relative to the AF fixed part 12 (magnet holder 121) by the upper spring 131, the upper spring 132, the lower spring 141, and the lower spring 142. In the positioned state, it is elastically supported so as to be displaceable on both sides in the Z direction.

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

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

In this embodiment, the surface of the slide plate 23 is subjected to low-friction treatment. Also, the ball 153 is in contact with the slide plate 23, and the contact area is extremely small. Therefore, although the OIS movable part 10 partially contacts the OIS fixed part 20 , the swing of the OIS movable part 10 is not hindered.

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

In this way, the force in the direction of the optical axis due to the impact of the drop is absorbed by the sliding portion 15 , so that the force transmitted to the suspension wire 30 , the AF support portion 13 , the AF support portion 14 , and the like is reduced. Therefore, it is possible to prevent the lens driving 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 portion 13 and the AF support portion 14 .

In this way, the lens driving device 1 includes: OIS fixed part 20 (shake correction fixed part); OIS movable part 10 (shake correction movable part), which can swing in a plane perpendicular to the optical axis; support part) supports the OIS movable part 10 in a state spaced apart from the OIS fixed part 20 in the optical axis direction; and a voice coil motor (drive source) makes the OIS movable part 10 swing.

In the lens driving device 1 , the OIS movable section 10 (one of the shake correction fixed section and the shake correction movable section) has a ball 153 (protruding section) protruding 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 slide plate 23 (flat portion) that is in contact with the ball 153 . The balls 153 and the slide plate 23 slide relative to each other during shake correction. Also, the ball 153 can be elastically displaced toward the optical axis.

According to the lens driving device 1 , the ball 153 is interposed between the OIS movable part 10 and the OIS fixed part 20 , and since the OIS movable part 10 is supported by the ball 153 , it is held in a stable posture. Thereby, the thinning of the suspension wire 30 and the thinning of the AF supporting part 13 and the AF supporting part 14 (wire fixing member) are promoted, and even if the rigidity of the members is lowered, it is possible to prevent the OIS movable part 10 from The performance of the AF function and the OIS function is degraded due to the in-plane displacement of the optical axis or the inclination relative to the optical axis. In addition, since the ball 153 is elastically displaceably held, the force acting upon a drop impact is absorbed by the sliding portion 15, thereby preventing damage to the constituent members of the lens driving device 1 . Therefore, according to the lens driving device 1 , size reduction and weight reduction can be achieved, and reliability can be improved.

As mentioned above, although the invention made by this inventor was concretely demonstrated 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 recessed to absorb the impact of falling is shown, but a biasing member may be interposed between the holding member 151 and the balls 153 so that the balls 153 face the optical axis. Resilience when displaced. For example, a leaf spring 154 (see FIG. 13 ) may be provided as the urging member. Since both ends of the leaf spring 154 are fixed by the holding member 151 , when the self-ball 153 receives a force in the direction of the optical axis, it bends.

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

Also, 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 also be applied. In this case, the holding member 151 may be composed of a plurality of members (see FIG. 15(A) ), or may be composed of a single member (see FIG. 15(B) ).

Also, the protruding portion may be integrally formed on the holding member 151 . At this time, it is preferable that the front end portion of the protruding portion (the portion abutting against the slide plate 23 ) has a spherical shape. Thereby, the sliding property of the OIS movable part 10 can be ensured similarly to the case where the ball 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, the base 21 and the coil substrate 22 may be provided separately.

Also, in the embodiment, the OIS movable part 10 is provided with a protruding part and the OIS fixed part 20 is provided with a flat part. department. Furthermore, not only the flat portion but also the protruding portion can be given a low-friction treatment.

In the embodiment, the smartphone M, which is a portable terminal equipped with a camera, has been described as an example of a camera-mounted device having a camera module A, but the present invention can be applied to a The camera-mounted device of the image processing part of the image information obtained by the module. Camera-mounted devices include information equipment and transportation equipment. Information equipment includes, for example: mobile phones equipped with cameras, notebook (note) personal computers (personal computers, PCs), tablet (tablet) terminals, portable game (game) machines, network (web) cameras, camera-equipped Vehicle-mounted devices (eg, back monitor devices, drive recorder devices). Also, the transport equipment includes, for example, automobiles.

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

In addition, 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, a drive magnet serving 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 its magnetization direction coincides with the radial direction. Alternatively, a flat 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 driving magnet may be arranged such that its magnetization direction intersects the coil surface of the AF coil.

In the embodiment, the case where the driving magnet is used as both the AF magnet and the OIS magnet in the lens driving device having the OIS function and the AF function has been described, but the AF magnet and the OIS magnet may be provided separately. Also, 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 having a driving source (for example, an ultrasonic motor) other than the VCM.

In the embodiment, the lens unit 2 is disposed on the OIS movable unit 10, the imaging unit is disposed on the OIS fixed unit 20, and the lens drive has a so-called optical shake correction function that performs shake correction by swinging the lens unit 2 relative to the imaging unit. The device 1 has been described, but the present invention can also be applied to a so-called sensor that arranges the lens unit on the OIS fixed unit, arranges the imaging unit on the OIS movable unit, and performs shake correction by swinging the imaging unit relative to the lens unit. Lens drive device with sensor shifting type shake correction function.

It should be understood that the entire contents of the disclosed embodiments of the present invention are illustrative and not restrictive. It means that the scope of the present invention is indicated not by the above-mentioned descriptions, but by the scope of the patent application, and includes any changes within the meaning equivalent to the scope of the patent application and within the range.

The disclosure contents of the specification, drawings and abstract contained in the Japanese application of Japanese Patent Application No. 2018-040489 filed on March 7, 2018 are all cited by this application.

1‧‧‧Lens driving device 2‧‧‧Lens Department 3‧‧‧Cover 3a‧‧‧opening 10‧‧‧OIS movable part (shake correction movable part) 11‧‧‧AF movable part 12‧‧‧AF fixed part 13, 14‧‧‧AF support department 15‧‧‧Sliding part 20‧‧‧OIS fixed part (shake correction fixed part) 21‧‧‧base 21a‧‧‧opening 21b‧‧‧Coil substrate fixing part 21c‧‧‧Sliding plate fixing part 22‧‧‧Coil substrate 22a‧‧‧opening 23‧‧‧Sliding plate (flat part) 23a‧‧‧The length direction of the four sides of the sliding plate is approximately in the center 30‧‧‧Suspension wire (shake correction support part)/OIS support part 111‧‧‧Lens holder 111a‧‧‧Lens storage unit 111b‧‧‧upper flange 111c‧‧‧Flange on the lower side 111d‧‧‧Upper spring fixing part 111e‧‧‧Lower spring fixing part 112‧‧‧Coil for AF 121‧‧‧Magnet holder 121a‧‧‧opening 121b‧‧‧Magnet holding part 121d‧‧‧Upper spring fixing part 122‧‧‧Drive magnet (magnet for AF) 131, 132‧‧‧upper spring 131a, 132a‧‧‧Lens holder fixing part 131b, 132b‧‧‧Magnet holder fixing part 131c, 132c‧‧‧arm 131d, 132d‧‧‧wire connection part 131e, 132e‧‧‧connection part 141, 142‧‧‧lower spring 141a, 142a‧‧‧Lens holder fixing part 141b, 142b‧‧‧Magnet holder fixing part 141c, 142c‧‧‧arm 151‧‧‧Retaining components 151a‧‧‧(holding member) thin-walled part 151b‧‧‧(holding member) thick wall part 151c‧‧‧Ball Containment Department 152‧‧‧Spacer 153‧‧‧Ball (Protrusion) 154‧‧‧leaf spring 211‧‧‧Terminal metal parts 221‧‧‧Coil for OIS A‧‧‧Camera Module M‧‧‧Smartphone (camera mounted device) OC‧‧‧Back Camera V‧‧‧Car VC‧‧‧Vehicle Camera Module X‧‧‧coordinate system/direction Y‧‧‧coordinate system/direction Z‧‧‧coordinate system/direction

1(A) and 1(B) are diagrams showing a smartphone equipped with a camera module according to an embodiment of the present invention. FIG. 2 is a perspective view of the appearance 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 an OIS movable part. Fig. 7 is a cross-sectional view of an OIS movable part. Fig. 8 is a bottom view of the OIS movable part. Fig. 9 is an exploded perspective view of an OIS fixing part. Fig. 10 is a plan view of an OIS fixing portion. FIG. 11(A) and FIG. 11(B) are diagrams showing a contact state between the protruding portion and the flat portion. 12(A) and 12(B) are diagrams showing the displacement state of the protruding portion. FIG. 13 is a diagram showing another example of a protruding portion. FIG. 14 is a diagram showing still another example of a protruding portion. FIG. 15(A) and FIG. 15(B) are diagrams showing a cantilever beam type protrusion. 16(A) and 16(B) are diagrams showing a car as a camera-mounted device equipped with a vehicle-mounted camera module.

23‧‧‧Sliding plate (flat part)

151‧‧‧Retaining components

151a‧‧‧(holding member) thin-walled part

152‧‧‧Spacer

153‧‧‧Ball (protruding part)

X‧‧‧coordinate system/direction

Z‧‧‧coordinate system/direction

Claims (12)

A lens driving device, comprising: a shake correction fixed part; a shake correction movable part capable of swinging in a plane perpendicular to an optical axis; a shake correction support part for positioning the shake correction movable part relative to the shake correction fixed part supported in a state spaced apart in the optical axis direction; and a driving source that causes the shake correction movable part to swing; and the lens driving device is characterized in that: the shake correction fixed part and the shake correction movable part One of them has a protruding portion protruding in the direction of the optical axis, the other of the shake correction fixed portion and the shake correction movable portion has a flat portion abutting on the protruding portion, and the protruding portion Sliding relative to the flat portion during shake correction, and the sliding surface of at least one of the protruding portion and the flat portion is subjected to a low-friction treatment to act on the lens driving device by a drop impact When a force is applied in the direction of the optical axis, the protruding portion can be elastically displaced in the direction of the optical axis. The lens driving device according to claim 1 of the patent claims, wherein the protruding part applies force to the flat part. The lens driving device according to claim 1 or claim 2, wherein the low-friction treatment is a nickel plating treatment for dispersing polytetrafluoroethylene particles. The lens driving device as described in item 1 or item 2 of the scope of patent application, which includes a holding member holding the protrusion, and the holding member has a beam portion supported at both ends or cantilevered, The protruding portion is arranged on the beam portion. The lens driving device according to claim 1 or claim 2 of the patent application, which includes: a holding member holding the protrusion; and a force applying member interposed between the holding member and the protrusion, And the urging member exerts a restoring force when the protruding portion is displaced in the direction of the optical axis. The lens driving device as described in claim 5 of the scope of the patent application, wherein the biasing member is a leaf spring mounted on the holding member in a supported or cantilevered manner at both ends. The lens driving device as described in item 5 of the scope of the patent application, wherein the biasing member is a compression coil spring. In the lens driving device as described in item 1 or item 2 of the patent claims, wherein the protruding portion has a spherical shape and is in point contact with the flat portion. The lens driving device according to claim 8, wherein the protruding part comprises a ball member. The lens driving device according to claim 1 or claim 2, wherein the driving source includes: a shake correction magnet disposed on any one of the shake correction fixed part and the shake correction movable part and a shake correction coil disposed on the other of the shake correction fixed part and the shake correction movable part. A camera module, characterized by comprising: the lens driving device described in any one of the first to tenth items of the scope of the patent application; A lens unit is attached to the shake correction movable unit; and an imaging unit captures a subject image formed by the lens unit. A camera-mounted device, which is a camera-mounted device used as an information machine or a transportation machine, and is characterized in that it includes: the camera module as described in item 11 of the scope of the patent application; Image information obtained by the module.

Images