JP2019070843A - Lens driving device - Google Patents

Abstract

To provide a lens driving device that enables accurate position control of a movable portion.SOLUTION: A lens driving device includes: a stationary portion having a storage space formed inside; a movable portion housed in the storage space and holding a lens; suspension wires disposed at four corners of the storage space viewed from the optical axial direction of the lens and supporting the movable portion in a relatively movable manner with respect to the stationary portion; and a driving unit for moving the movable portion in the optical axis orthogonal direction of the lens. The stationary portion includes a case 12 having a top flat plate portion 12a having a through hole formed for guiding light to the lens and extending toward the optical axis orthogonal direction and a side portion 12b connecting with the outer periphery of the top flat plate portion and extending in the optical axis direction. The movable portion has: a top stopper face 42a disposed at the center part among the four corners viewed from the optical axis direction, capable of abutting on the top flat plate portion, and regulating the movement of the movable portion in the optical axis direction; and a side portion stopper face 42b disposed at the center part, capable of abutting on the side portion, and regulating the movement of the movable portion in the optical axis orthogonal direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a lens driving device suitably used for, for example, a camera module of a mobile phone.

  As a lens driving device suitably used for a camera module or the like of a mobile phone, there has been proposed a lens driving device in which a movable portion movable by a driving means or the like is accommodated inside a fixed portion such as a case. In such a lens drive device, an optical camera shake correction (OIS) or an autofocus (AF) can be performed by moving the lens held by the movable portion in the optical axis direction or the optical axis orthogonal direction with respect to the imaging device or the like. It can be realized.

  Moreover, as a support structure of a movable part, the structure using the suspension wire etc. which have flexibility is proposed (refer patent document 1 grade | etc.,). The movable part supported by the suspension wire may contact the inner surface of the case unintentionally by being moved to the movable limit by the drive part or by an external force applied to the lens drive part.

International Publication 2009/133691

  In the conventional structure of the movable part and the fixed part, when the movable part comes in contact with the inner surface of the case, the movable part may receive a force that hinders the movement as intended, which hinders accurate position control of the movable part was there.

The present invention has been made in view of such circumstances, and an object thereof is to provide a lens drive device which enables accurate position control of a movable portion.
The inventors of the present invention have observed that adhesion of particles (micro-pieces) generated by bonding operation during assembly or contact between members after assembly to the contact surface, and that the projection of the movable part gets stuck in the corner of the case Have found that the force that inhibits the movement of the movable part is generated, and completed the present invention.

In order to achieve the above object, a lens driving device according to a first aspect of the present invention is
A fixed part that forms a storage space inside;
A movable portion housed in the housing space and holding a lens;
A suspension wire disposed at four corners of the storage space when viewed from the optical axis direction of the lens, and supporting the movable portion relative to the fixed portion so as to be movable relative to the fixed portion;
A driving unit for moving the movable unit in a direction perpendicular to the optical axis of the lens;
The fixed part is
A case having a through hole for guiding light to the lens and having an upper flat portion extending in the direction orthogonal to the optical axis, and a side portion connected to the outer periphery of the upper flat portion and extending in the optical axis direction Have
The movable portion is disposed at a central portion between the four corners when viewed from the optical axis direction, and is capable of abutting on the upper flat plate portion, and restricts the movement of the movable portion in the optical axis direction. And a side stopper surface disposed at the central portion and capable of abutting on the side surface to restrict movement of the movable portion in the direction orthogonal to the optical axis.

  In the lens driving device according to the first aspect of the present invention, since the upper stopper surface and the side stopper surface are located at the central portion, the stopper surface is the joint portion between the suspension wire and the movable portion or the fixed portion. It is placed at a position away from. In the joint portion, particles are likely to be generated due to the bonding operation at the time of assembly, friction after assembly, etc. However, by disposing the joint portion and the stopper surface at a separated position, adhesion of particles to the stopper surface is prevented. The lens drive device according to the first aspect enables accurate position control of the movable portion.

  Also, for example, the upper stopper surface may be narrower than the side stopper surface.

  By making the upper stopper surface narrower than the side stopper surface, it is possible to suppress the generation of particles due to the contact between the stopper surface and the case.

  Further, for example, the movable portion is disposed at a position closer to the four corners than the side stopper surface, and can be in contact with the side portion to restrict movement of the movable portion in the optical axis rotation direction. It may have a face.

  Since rotation of the movable portion can be suppressed by the movable portion having the rotation stopper surface, it is possible to suppress unintended movement of the movable portion and to suppress generation of particles caused by collision of the movable portion with the case.

  Also, for example, the movable portion may have at least four upper stopper surfaces respectively disposed at the four central portions between the four corners.

  Such a lens drive device can suppress the tilting of the movable portion in the direction in which the optical axis of the lens is tilted, and can suppress the generation of particles caused by the collision between the movable portion and the case.

The lens drive device according to the second aspect of the present invention is
A fixed part that forms a storage space inside;
A movable portion housed in the housing space and holding a lens;
A support portion for supporting the movable portion so as to be movable relative to the fixed portion;
A driving unit for moving the movable unit in a direction perpendicular to the optical axis of the lens;
The fixed part is
A through hole for guiding light to a lens is formed, and it has an upper flat plate extending in the direction perpendicular to the optical axis, and a side face connected to the outer periphery of the upper flat plate and extending in the optical axis direction of the lens. Have a case,
The movable portion is
The upper stopper surface that can abut against the upper flat plate part and restricts the movement of the movable part in the optical axis direction, and the movement of the movable part in the orthogonal direction of the optical axis can abut against the side face part The upper stopper surface and the upper stopper surface are disposed at a predetermined distance or more on the optical axis side from a virtual intersection line at which the side stopper surface to be restricted and the imaginary extension surfaces of the upper stopper surface and the side stopper surface intersect. And a connecting portion for connecting to the side stopper surface.

  In the lens driving device according to the second aspect of the present invention, the connection portion is disposed at a position equal to or more than a predetermined distance from the virtual intersection line, thereby preventing the problem of the stopper portion getting stuck in the corner of the case Enables accurate position control of parts.

  In addition, for example, the connection portion may have a connection surface which continuously connects the upper stopper surface and the side stopper surface.

  The stopper portion having the connection surface is easy to manufacture because its shape is simple.

  Also, for example, the movable portion may include an optical axis direction drive portion that moves the lens in the optical axis direction.

  Such a lens holding device can cause the lens to perform movement associated with optical shake correction (OIS) and autofocus (AF) operations.

FIG. 1 is a perspective view of a lens drive device according to an embodiment of the present invention. FIG. 2 is a schematic exploded perspective view of the lens driving device shown in FIG. FIG. 3 is a cross-sectional view of the lens driving device shown in FIG. FIG. 4 is a plan view of the inside of the storage space as viewed from the optical axis direction. FIG. 5 is a plan view showing the arrangement of stopper surfaces in a lens drive device according to a modification.

  FIG. 1 is a perspective view of a lens drive device 10 according to an embodiment of the present invention. The lens drive device 10 has a substantially rectangular parallelepiped outer shape. As shown in FIG. 2, which is an exploded view, the lens driving device 10 is formed inside the fixing portion 19 and the fixing portion 19 which includes the case 12 and the bottom 78 and the like and constitutes the outer surface portion of the lens driving device 10. The movable portion 18 is accommodated in the accommodation space and holds a lens (not shown). The lens driving device 10 is used as a camera module or the like having a focusing mechanism and an optical image stabilization mechanism in combination with an image pickup device disposed on the emitting side (see FIG. 1). It is not limited to. In the description of the lens driving device 10, the side on which the imaging light is incident on the lens along the optical axis α of the lens is referred to as the incident side, and the side on which the incident imaging light is emitted is referred to as the emission side.

  FIG. 2 is a schematic exploded perspective view of the lens driving device 10 shown in FIG. The fixing portion 19 of the lens driving device 10 has a case 12, an FP coil 73, an FPC 74, and a bottom 78. The fixed portion 19 forms a storage space 11 (see FIG. 3) for storing the movable portion 18 between the case 12 and the FP coil 73.

  The case 12 is formed with a through hole 12c for guiding light to the lens, and is connected to the outer periphery of the upper flat plate portion 12a extending in the direction orthogonal to the optical axis and the outer side of the upper flat plate portion 12a And 12b. The case 12 is attached to the bottom 78 from the optical axis direction incident side with the movable portion 18, the FP coil 73 and the FPC 74 interposed therebetween. In the accommodation space 11 (see FIG. 3) for accommodating the movable portion 18, the upper flat plate portion 12a of the case 12 constitutes a wall on the light axis direction incident side, and the side face portion 12b constitutes a wall in the optical axis orthogonal direction. The coil 73 constitutes a wall on the light emitting side in the optical axis direction. In the FP coil 73, the FPC 74, and the bottom 78, through holes are formed for the lens or the emission hole from the lens to pass through.

  As shown in FIG. 3 which is a cross-sectional view of the lens drive device 10, the sheet-like members FP coil 73 (flexible printed coil) and FPC 74 (flexible printed circuit board) are disposed overlapping on the incident side surface of the bottom 78. Ru. The FP coil 73 is disposed on the uppermost surface (incident side) of the three members constituting the lower surface of the fixed portion 19 and faces the emission side surface of the magnet 48 in the movable portion 18. The FP coil 73 has four coils (not shown) covered by a base film, and the four coils and the magnet 48 constitute a first drive unit for moving the movable unit 18 in the direction orthogonal to the optical axis. .

  The FPC 74 is formed with an electronic circuit for controlling the current value of the coil contained in the FP coil 73 and the coil 52 attached to the lens holder 50 of the movable portion 18, and the end of the FPC 74 is formed. An external terminal for transmitting and receiving signals with an external control circuit and supplying power is formed.

  The bottom 78 has a role of a frame giving rigidity to the lower surface of the fixed portion 19 for supporting the movable portion 18, and is made of resin or the like. In the bottom 78, a through hole 78a for housing the hall sensor 76 is formed. The Hall sensor 76 is a movement detection unit for detecting the movement of the movable unit 18 in the direction perpendicular to the optical axis, and two Hall sensors 76 for detecting the position in two directions orthogonal to the optical axis It is fixed to the exit side surface. Each Hall sensor 76 is disposed on the emission side of the magnet 48 as viewed from the optical axis direction so that a change in the magnetic field formed by the magnet 48 can be suitably detected. By housing the hall sensor 76 in the through hole 78a of the bottom 78, it is possible to suppress the height of the lens driving device 10, and the through hole 78a of the bottom 78 in which the hall sensor 76 is housed is In order to prevent the generation of particles when the Hall sensor 76 is attached to the FPC 74, it is preferable that the resin be filled.

  As shown in FIG. 2, the movable portion 18 is supported so as to be movable relative to the fixed portion by suspension wires 17 as support portions disposed at four corners of the storage space when viewed from the optical axis direction. The incident side end of the suspension wire 17 is fixed to the wire holding portion 33 of the incident side spring 30 in the movable portion 18, and the emission side end is connected to the four corners of the FP coil 73. At least two of the four suspension wires 17 can be energized, and power can be supplied to the coil 52 (see FIG. 3) of the movable portion 18 via the incident side spring 30. The suspension wire 17 used as a feed path is electrically connected to the FPC 74.

  As shown in FIGS. 2 and 3, the movable portion 18 has an incident side spring 30, a cap 40 to which the magnet 48 is fixed, a lens holder 50 to which the coil 52 is attached, and an exit side spring 60. The entrance side spring 30 and the exit side spring 60 are disposed so as to sandwich the cap 40 and the lens holder 50 in the optical axis direction. The entrance side spring 30 and the exit side spring 60 have an outer ring portion fixed to the cap 40, an inner ring portion fixed to the lens holder 50, and an arm portion connecting the inner ring portion and the outer ring portion. doing. The entrance side spring 30 and the exit side spring 60 are made of an elastic material such as metal, and hold the lens holder 50 relatively movable in the optical axis direction with respect to the cap 40 by the elastic deformation of the arm portion. . Further, the incident side spring 30 has wire holding portions 33 for fixing the suspension wires 17 at the four corners.

  As shown in FIGS. 2 and 3, the lens holder 50 has a cylindrical portion, and the lens is fixed to the inner peripheral surface of the cylindrical portion, and the coil 52 is fixed to the outer peripheral surface of the cylindrical portion. Is fixed. The coil 52 is disposed to face the magnet 48 fixed to the cap 40. The coil 52 and the magnet 48 constitute an optical axis direction drive unit that moves the lens in the optical axis direction.

  As shown in FIG. 4 which is a plan view of the incident side spring 30 and the cap 40 in the housing space, the cap 40 has four stopper portions 42 disposed at the center between the four corners when viewed from the optical axis direction. . As shown in FIG. 3, the stopper portion 42 can be in contact with the upper flat plate portion 12 a of the case 12 and restricts the movement of the movable portion 18 in the optical axis direction, and the side surface portion 12 b of the case 12 And a side stopper surface 42b that restricts the movement of the movable portion 18 in the direction orthogonal to the optical axis. Further, in the stopper portion 42, a connection portion surface 42ca which is a surface of the connection portion 42c connecting the upper stopper surface 42a and the side stopper surface 42b continuously has the upper stopper surface 42a and the side stopper surface 42b. Connecting.

  As shown in FIG. 4, the stopper portions 42 are preferably arranged at substantially equal distances from two adjacent corners, but are not particularly limited. Further, it is preferable that the distance from the suspension wire 17 to the end of the upper stopper surface 42a or the side stopper surface 42b is equal to (quarter) or more of the distance between the adjacent suspension wires 17.

  As shown in FIG. 3, the upper stopper surface 42 a is a surface closest to the upper flat plate portion 12 a in the movable portion 18, and the side stopper surface 42 b is the most side surface 12 b in the movable portion 18. It is a plane close to the distance to Therefore, the upper stopper surface 42 a of the case 12 when the movable portion 18 moves in the storage space in the optical axis incident direction while the movable portion 18 is deformed by the impact from the outside with the incident side spring 30 or the like near the wire holding portion 33. It abuts on the upper flat plate portion 12 a and restricts the movement of the movable portion 18 in the optical axis direction. Further, the side stopper surface 42b moves in contact with the side surface portion 12b of the case 12 when the movable portion 18 moves to the movable limit position in the optical axis orthogonal direction by the driving force by the first drive portion or external impact. The movement of the portion 18 in the direction orthogonal to the optical axis is restricted. The upper stopper surface 42 a is preferably narrower than the side stopper surface 42 b from the viewpoint of particle generation prevention. The side stopper surface 42 b is preferably wider than the upper stopper surface 42 a from the viewpoint of stabilizing the movable limit position of the movable portion 18.

  Further, as shown in the partial enlarged view in FIG. 3, the connecting portion 42 c in the stopper portion 42 is downward (outgoing side) from the virtual intersection line 42 d where the virtual extension surfaces of the upper stopper surface 42 a and the side stopper surface 42 b intersect. And it is preferable to arrange | position in the position more than predetermined distance D1 in the optical axis side.

  As shown in FIG. 4, the cap 40 has a rotation stopper surface 44 that restricts the movement of the movable portion 18 in the optical axis rotation direction. The rotation stopper surfaces 44 are disposed closer to the four corners of the storage space 11 than the side stopper surfaces 42b, and are disposed below the side stopper surfaces 42b. The rotation stopper surface 44 abuts against the side surface portion 12 b of the case 12 to restrict the movement of the movable portion 18 when the movable portion 18 is rotated about the optical axis by an external force. The rotation stopper surface 44 can suppress an unintended movement of the movable portion 18 and can suppress generation of particles caused by a collision between the movable portion 18 and the case 12. Further, the rotation stopper surface 44, together with the upper stopper surface 42a and the side stopper surface 42b, also has a function of preventing plastic deformation of the incident spring, the suspension wire and the like due to an impact such as falling.

  In the lens driving device 10 according to the present embodiment, since the upper stopper surface 42 a and the side stopper surface 42 b are located at the central portion, the stopper surfaces 42 a and 42 b join the suspension wire 17 and the movable portion 18. It is placed at a position away from the part. In the joint portion of the suspension wire 17, particles are likely to be generated due to the joint operation at the time of assembly and friction after assembly, but since the joint portion and the stopper surfaces 42a and 42b are separated, particles to the stopper surfaces 42a and 42b Can prevent the adhesion of Thereby, the lens drive device 10 can accurately move the movable portion 18 in the optical axis orthogonal direction. That is, when particles adhere to the upper stopper surface 42a, the particles may intervene between the upper stopper surface 42a and the upper flat plate portion 12a and interfere with the smooth movement of the movable portion 18. Can prevent such problems. When adhesive particles adhere to the side stopper surface 42b, the side stopper surface 42b is stuck to the side surface portion 12b, and when the movable portion 18 reaches the movable limit position and when the movable portion 18 leaves the movable limit position, Although a large difference may occur in the driving force of the movable portion 18 to make accurate position control difficult, the lens driving device 10 can prevent such a problem.

  In addition, the stopper portion 42 has a connecting portion 42c disposed below the virtual intersection line 42d where the virtual extension surfaces of the upper stopper surface 42a and the side stopper surface 42b intersect with each other at a predetermined distance or more on the optical axis side. Therefore, the lens drive device 10 prevents the problem that the stopper portion 42 gets stuck in the corner of the case 12 and realizes accurate control of the movable portion 18.

Other Embodiments The shapes and the like of the magnets 48 and the springs 30, 60 included in the lens drive device 10 may be appropriately adjusted according to the specifications required for the lens drive device 10. Further, the support portion for supporting the movable portion 18 is not limited to the suspension wire 17 but may be a structure using a slider or a structure combining a ball and a receiving surface. Further, as shown in FIG. 4, the cap 40 has four upper stopper surfaces 42a respectively disposed at four central portions, and prevents the movable portion 18 from tilting in the direction in which the optical axis of the lens is tilted. Although it can do, it is possible to change suitably the number and arrangement | positioning of the stopper part which a movable part has. As shown in FIG. 3, in the lens driving device 10, the connection portion 42c and the connection portion surface 42ca have a shape obtained by chamfering the end portion of the stopper portion 42, but the shape of the connection portion is not limited thereto. Alternatively, the end of the stopper may be rounded or L-shaped.

  FIG. 5 is a plan view showing the shape of a cap 90 according to a modification. The cap 90 has a total of eight stopper portions 92, two on each side, and a lens drive having such a cap 90 instead of the cap 40 (see FIG. 4 etc.) is also accurate for the movable portion. Control can be realized.

DESCRIPTION OF SYMBOLS 10 ... Lens drive device 12 ... Case 12a ... Upper flat plate part 12b ... Side surface part 17 ... Suspension wire 18 ... Movable part 19 ... Fixed part 30 ... Incident side spring 40 ... Cap 42 ... Stopper part 42a ... Upper stopper surface 42b ... Side part Stopper surface 42c ... Connection section 42d ... Virtual crossing line 44 ... Rotation stopper surface 48 ... Magnet 50 ... Lens holder 60 ... Ejection side spring 73 ... FP coil 74 ... FPC
76 Hall sensor 78 bottom

Claims (8)

A fixed part that forms a storage space inside;
A movable portion housed in the housing space and holding a lens;
A support portion for supporting the movable portion so as to be movable relative to the fixed portion;
A drive unit for moving the movable unit in a direction orthogonal to the optical axis;
The fixed part is
There is a case having a through hole for guiding light to a lens and having an upper flat portion extending in the direction perpendicular to the optical axis and a side portion connected to the outer periphery of the upper flat portion and extending in the optical axis direction. And
The movable portion is
A lens holder that holds the lens and the coil is fixed;
An upper stopper surface which can abut against the upper flat plate portion and restricts the movement of the movable portion in the optical axis direction, and a movement of the movable portion orthogonal to the optical axis which can abut against the side surface portion A cap which has a side stopper surface for restricting the magnet, and a magnet which is opposed to the coil in the direction perpendicular to the optical axis and acts with the coil to move the lens holder in the optical axis direction is fixed; A lens driving device having   The lens driving device according to claim 1, wherein the upper stopper surface and the side stopper surface are disposed at a central portion between four corners of the cap when viewed from the optical axis direction. A connecting portion disposed between the upper stopper surface and the side stopper surface and connecting the upper stopper surface to the side stopper surface;
The distance between the connecting portion and the case is equal to or greater than the distance between the upper stopper surface and the upper flat plate portion, and is equal to or greater than the distance between the side stopper surface and the side portion. The lens drive device of Claim 1 or Claim 2.   The lens drive device according to claim 3, wherein the connection portion has a shape in which an end portion of a stopper portion having the upper stopper surface and the side stopper surface is cut out in an L shape.   The lens driving device according to any one of claims 1 to 4, wherein a distance between the upper stopper surface and the upper flat plate portion in the movable portion is the shortest.   The lens drive according to any one of claims 1 to 5, further comprising a spring which is directly connected to the lens holder and the cap and holds the lens holder so as to be movable relative to the cap in the optical axis direction. apparatus.   The lens drive device according to any one of claims 1 to 6, wherein the side stopper surface is disposed above the upper end of the coil in the storage space. A storage space is formed inside, a through hole for guiding light to the lens is formed, and an upper flat plate extending in a direction orthogonal to the optical axis, and a side face extending in the optical axis direction connected to the outer periphery of the upper flat And a case having
A lens holder which is housed in the housing space, holds a lens, and to which a coil is fixed;
An upper stopper surface which is accommodated in the accommodation space and which can be in contact with the upper flat plate portion and restricts the movement of the movable portion in the optical axis direction; And a side stopper surface for restricting the movement of the lens in the direction orthogonal to the optical axis, and the coil faces the coil in the direction orthogonal to the optical axis and acts on the coil to move the lens holder in the optical axis direction And a cap to which a magnet is fixed.

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