JP6786634B2 - Lens drive device - Google Patents

Description

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

As a lens driving device preferably used for a camera module of a mobile phone or the like, a lens driving device in which a movable portion movable by a driving means or the like is housed inside a fixed portion such as a case has been proposed. In such a lens driving device, optical image stabilization (OIS) and autofocus (AF) are 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 image pickup element or the like. It can be realized.

Further, as a support structure for the movable portion, a structure using a flexible suspension wire or the like has been proposed (see Patent Document 1 and the like). The movable portion supported by the suspension wire may come into contact with the inner surface of the case intentionally by being moved to the movable limit by the drive portion or unintentionally due to an external force applied to the lens drive portion.

International Publication No. 2009/133691

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

The present invention has been made in view of such an actual situation, and an object of the present invention is to provide a lens driving device that enables accurate position control of a movable portion.
The inventors of the present invention have described a phenomenon in which particles (small pieces) generated by joining work during assembly or contact between members after assembly adhere to the contact surface, and protrusions of movable parts get stuck in the corners of the case. However, it was found that a force that hinders the movement of the movable part was generated, and the present invention was completed.

In order to achieve the above object, the lens driving device according to the first aspect of the present invention is
A fixed part that forms a storage space inside,
A movable part that is stored in the storage space and holds the lens,
Suspension wires that are arranged at the four corners of the storage space when viewed from the optical axis direction of the lens and support the movable portion relative to the fixed portion so as to be movable.
It has a drive unit that moves the movable portion in the direction orthogonal to the optical axis of the lens.
The fixed part is
A case in which a through hole for guiding light is formed in the lens and has an upper flat plate portion extending in the direction orthogonal to the optical axis and a side surface portion connected to the outer periphery of the upper flat plate portion and extending in the optical axis direction. Have,
The movable portion is arranged in the central portion between the four corners when viewed from the optical axis direction, and is capable of contacting the upper flat plate portion with an upper stopper surface that regulates the movement of the movable portion in the optical axis direction. It has a side stopper surface which is arranged in the central portion and is capable of contacting the side surface portion and regulates the 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 in the central portion, these stopper surfaces are the joint portions between the suspension wire and the movable portion or the fixed portion. It is placed away from. At the joint part, particles are likely to be generated due to the joining work during assembly and friction after assembly, but by arranging the joint part and the stopper surface at separate positions, it is possible to prevent particles from adhering to the stopper surface. The lens driving device according to the first aspect enables accurate position control of the movable portion.

Further, 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 arranged at a position closer to the four corners than the side stopper surface, and is capable of contacting the side surface portion and regulates the movement of the movable portion in the optical axis rotation direction. It may have a surface.

Since the movable portion has the rotation stopper surface, the rotation of the movable portion can be suppressed, so that the unintended movement of the movable portion can be suppressed, and the generation of particles due to the collision between the movable portion and the case can be suppressed.

Further, for example, the movable portion may have at least four upper stopper surfaces arranged in each of the four central portions between the four corners.

Such a lens driving device can suppress the tilting of the movable portion in the direction of tilting the optical axis of the lens, and can suppress the generation of particles due to the collision between the movable portion and the case.

The lens driving device according to the second aspect of the present invention is
A fixed part that forms a storage space inside,
A movable part that is stored in the storage space and holds the lens,
A support portion that supports the movable portion relative to the fixed portion so as to be movable,
It has a drive unit that moves the movable portion in the direction orthogonal to the optical axis of the lens.
The fixed part is
A through hole for guiding light is formed in the lens and has an upper flat plate portion extending in the direction orthogonal to the optical axis and a side surface portion connected to the outer periphery of the upper flat plate portion and extending in the optical axis direction of the lens. Have a case,
The movable part is
The upper stopper surface that can be in contact with the upper flat plate portion and regulates the movement of the movable portion in the optical axis direction and the movement of the movable portion in the optical axis orthogonal direction that can be in contact with the side surface portion. The upper stopper surface and the upper stopper surface are arranged at a position equal to or more than a predetermined distance below the virtual intersection line where the regulated side stopper surface and the virtual extension surfaces of the upper stopper surface and the side stopper surface intersect each other and on the optical axis side. It has a stopper portion having a connecting portion for connecting to the side stopper surface.

The lens driving device according to the second aspect of the present invention is movable by preventing the problem that the stopper portion gets stuck in the corner of the case because the connecting portion is arranged at a position equal to or more than a predetermined distance from the virtual intersection line. It enables accurate position control of the part.

Further, for example, the connection portion may have a connection surface that continuously connects the upper stopper surface and the side stopper surface.

Since the stopper portion having the connection surface has a simple shape, it is easy to manufacture.

Further, for example, the movable portion may have an optical axis direction driving portion that moves the lens in the optical axis direction.

Such a lens holding device allows the lens to perform movements associated with optical image stabilization (OIS) and autofocus (AF) operations.

FIG. 1 is a perspective view of a lens driving 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 the stopper surface in the lens driving device according to the modified example.

FIG. 1 is a perspective view of a lens driving device 10 according to an embodiment of the present invention. The lens driving 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 including the case 12, the bottom 78, and the like, and forming the outer surface portion of the lens driving device 10. It is housed in a storage space and has a movable portion 18 for holding a lens (not shown). The lens drive device 10 is used as a camera module or the like having a focus mechanism and an optical image stabilization mechanism in combination with an image sensor arranged on the emission side (see FIG. 1), but the lens drive device 10 is used for this purpose. Not limited to. In the description of the lens driving device 10, the side where the photographing light is incident on the lens is defined as the incident side, and the side which emits the incident captured light is defined as the emitting side along the optical axis α of the lens.

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 accommodating the movable portion 18 between the case 12 and the FP coil 73.

In the case 12, a through hole 12c for guiding light to the lens is formed, and an upper flat plate portion 12a extending in the direction orthogonal to the optical axis and a side surface portion connected to the outer periphery of the upper flat plate portion 12a and extending toward the emission side in the optical axis direction. It has 12b and. 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 sandwiched between them. In the storage 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 incident side in the optical axis direction, the side surface portion 12b constitutes a wall in the direction orthogonal to the optical axis, and the FP. The coil 73 constitutes a wall on the exit side in the optical axis direction. The FP coil 73, the FPC 74, and the bottom 78 are formed with through holes through which the lens or the exit hole from the lens passes.

As shown in FIG. 3, which is a cross-sectional view of the lens driving device 10, the FP coil 73 (flexible printed coil) and the FPC 74 (flexible printed circuit board), which are sheet-like members, are arranged so as to be overlapped on the incident side surface of the bottom 78. To. The FP coil 73 is arranged on the uppermost surface (incident side) of the three members constituting the lower surface of the fixed portion 19, and faces the exit side surface of the magnet 48 in the movable portion 18. The FP coil 73 has four coils (not shown) covered with a base film, and the four coils and the magnet 48 form a first drive unit that moves the movable portion 18 in the direction orthogonal to the optical axis. ..

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

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

As shown in FIG. 2, the movable portion 18 is supported by suspension wires 17 as support portions arranged at the four corners of the storage space when viewed from the optical axis direction so as to be movable relative to the fixed portion. The incident side end portion 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 exit side end portion is connected to the four corners of the FP coil 73. At least two of the four suspension wires 17 can be energized, and electric 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 the power feeding 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 outgoing spring 60. The incident side spring 30 and the exit side spring 60 are arranged so as to sandwich the cap 40 and the lens holder 50 in the optical axis direction. The incident 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 incident side spring 30 and the outgoing side spring 60 are made of an elastic material such as metal, and the lens holder 50 is held so as to be relatively movable in the optical axis direction with respect to the cap 40 by elastically deforming 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 tubular portion, a lens is fixed to the inner peripheral surface of the tubular portion, and a coil 52 is formed on the outer peripheral surface of the tubular portion. Is fixed. The coil 52 is arranged so as to face the magnet 48 fixed to the cap 40, and the coil 52 and the magnet 48 form an optical axis direction driving 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 accommodation space, the cap 40 has four stopper portions 42 arranged in the central portion between the four corners when viewed from the optical axis direction. .. As shown in FIG. 3, the stopper portion 42 has an upper stopper surface 42a that can come into contact with the upper flat plate portion 12a of the case 12 and regulates the movement of the movable portion 18 in the optical axis direction, and a side surface portion 12b of the case 12. It has a side stopper surface 42b that can be brought into contact with the movable portion 18 and regulates the movement of the movable portion 18 in the direction orthogonal to the optical axis. Further, in the stopper portion 42, the connecting portion surface 42ca, which is the surface of the connecting portion 42c connecting the upper stopper surface 42a and the side stopper surface 42b, continuously connects the upper stopper surface 42a and the side stopper surface 42b. Connecting.

As shown in FIG. 4, the stopper portion 42 is preferably arranged at positions substantially equidistant from two adjacent corners, but is not particularly limited. Further, the distance from the suspension wire 17 to the end of the upper stopper surface 42a or the side stopper surface 42b is preferably (1/4) or more of the distance between the adjacent suspension wires 17.

As shown in FIG. 3, the upper stopper surface 42a is the surface of the movable portion 18 having the shortest distance to the upper flat plate portion 12a, and the side stopper surface 42b is the side surface portion 12b of the movable portion 18. It is a surface that is close to. Therefore, 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 incident side spring 30 or the like in the vicinity of the wire holding portion 33 due to an external impact, the upper stopper surface 42a of the case 12 It abuts on the upper flat plate portion 12a and regulates the movement of the movable portion 18 in the optical axis direction. Further, the side stopper surface 42b is movable 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 direction orthogonal to the optical axis due to the driving force of the first driving portion or the impact from the outside. The movement of the unit 18 in the direction orthogonal to the optical axis is regulated. The upper stopper surface 42a is preferably narrower than the side stopper surface 42b from the viewpoint of preventing particle generation. The side stopper surface 42b is preferably wider than the upper stopper surface 42a from the viewpoint of stabilizing the movable limit position of the movable portion 18.

Further, as shown in the partially enlarged view in FIG. 3, the connecting portion 42c in the stopper portion 42 is below (exit side) from 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. Moreover, it is preferable that the device is arranged at a predetermined distance D1 or more on the optical axis side.

As shown in FIG. 4, the cap 40 has a rotation stopper surface 44 that regulates the movement of the movable portion 18 in the optical axis rotation direction. The rotation stopper surface 44 is arranged at a position closer to the four corners of the storage space 11 than the side stopper surface 42b, and is arranged below the side stopper surface 42b. The rotation stopper surface 44 contacts the side surface portion 12b of the case 12 to regulate the movement of the movable portion 18 when the movable portion 18 rotates about the optical axis due to an external force. The rotation stopper surface 44 can suppress the unintended movement of the movable portion 18, and can also suppress the generation of particles due to the 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 the incident spring, suspension wire, and the like from being plastically deformed due to an impact such as dropping.

In the lens driving device 10 according to the present embodiment, since the upper stopper surface 42a and the side stopper surface 42b are located in the central portion, these stopper surfaces 42a and 42b are joined to the suspension wire 17 and the movable portion 18. It is placed at a position away from the part. Particles are likely to be generated at the joint portion of the suspension wire 17 due to the joining work at the time of assembly, friction after assembly, etc., but since the joint portion and the stopper surfaces 42a and 42b are separated, particles on the stopper surfaces 42a and 42b Can be prevented from adhering. As a result, the lens driving device 10 can accurately move the movable portion 18 in the direction orthogonal to the optical axis. 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 to hinder the smooth movement of the movable portion 18, but the lens driving device 10 Can prevent such problems. Further, when sticky particles adhere to the side stopper surface 42b, the side stopper surface 42b is attracted to the side surface portion 12b, and when the movable portion 18 reaches the movable limit position and when it separates from the movable limit position, Accurate position control may be difficult due to a large difference in the driving force of the movable portion 18, and the lens driving device 10 can prevent such a problem.

Further, the stopper portion 42 has a connecting portion 42c arranged at a position below a virtual intersection line 42d where the virtual extension surfaces of the upper stopper surface 42a and the side stopper surface 42b intersect each other and on the optical axis side at a predetermined distance or more. Therefore, the lens driving 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 of the magnets 48, springs 30, and 60 included in the lens driving device 10 can be appropriately adjusted according to the specifications required for the lens driving device 10. Further, the support portion that supports the movable portion 18 is not limited to the suspension wire 17, and may be a structure using a slider, a structure in which a ball and a receiving surface are combined, or the like. Further, as shown in FIG. 4, the cap 40 has four upper stopper surfaces 42a arranged at each of the four central portions, thereby preventing the movable portion 18 from tilting in the direction in which the optical axis of the lens tilts. However, the number and arrangement of the stopper portions of the movable portion can be changed as appropriate. As shown in FIG. 3, in the lens driving device 10, the connecting portion 42c and the connecting portion surface 42ca have a shape in which the end portion of the stopper portion 42 is chamfered, but the shape of the connecting portion is not limited to this. , The end portion of the stopper portion may be rounded or cut out in an L shape.

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

10 ... Lens drive device 12 ... Case 12a ... Upper flat plate part 12b ... Side 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 part 42d ... Virtual intersection line 44 ... Rotating stopper surface 48 ... Magnet 50 ... Lens holder 60 ... Exit side spring 73 ... FP coil 74 ... FPC
76 ... Hall sensor 78 ... Bottom

Claims (7)

A fixed part that forms a storage space inside,
A movable part that is stored in the storage space and holds the lens,
A support portion that supports the movable portion relative to the fixed portion so as to be movable,
It has a drive unit that moves the movable unit in the direction orthogonal to the optical axis.
The fixed part is
There is a case in which a through hole for guiding light is formed in the lens and has an upper flat plate portion extending in the direction orthogonal to the optical axis and a side surface portion connected to the outer periphery of the upper flat plate portion and extending in the optical axis direction. And
The movable part is
A lens holder that holds the lens and fixes the coil,
An upper stopper surface that can abut the upper flat plate portion and regulates the movement of the movable portion in the optical axis direction, and an upper stopper surface that can abut the side surface portion and restrict the movement of the movable portion in the direction orthogonal to the optical axis. A cap having a side stopper surface that regulates the lens, and a cap to which a magnet is fixed that faces the coil in the direction orthogonal to the optical axis and acts with the coil to move the lens holder in the optical axis direction. Have,
It is arranged between the upper stopper surface and the side stopper surface, and has a connecting portion for connecting the upper stopper surface and 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 greater than or equal to the distance between the side stopper surface and the side surface portion. apparatus. The lens driving device according to claim 1, wherein the upper stopper surface and the side stopper surface are arranged in the central portion between the four corners of the cap when viewed from the optical axis direction. The lens driving device according to claim 1, wherein the connecting 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 3, wherein the upper stopper surface has the shortest distance between the movable portion and the upper flat plate portion. The lens drive according to any one of claims 1 to 4, further comprising a spring that is directly connected to the lens holder and the cap and holds the lens holder so as to be relatively movable in the optical axis direction with respect to the cap. apparatus. The lens driving device according to any one of claims 1 to 5, wherein the side stopper surface is arranged above the upper end of the coil in the storage space. An upper flat plate portion that forms a storage space inside and has a through hole for guiding light to the lens and extends in the direction orthogonal to the optical axis, and a side surface portion that connects to the outer circumference of the upper flat plate portion and extends in the optical axis direction. And the case with
A lens holder that is stored in the storage space, holds the lens, and fixes the coil.
The housing is accommodated in the space, an upper stop surface for restricting the direction of the optical axis of movement of the said a contactable to the upper flat plate portion lens holder, the lens a possible contact with the side surface portion It has a side stopper surface that regulates the movement of the holder in the direction perpendicular to the optical axis, faces the coil in the direction orthogonal to the optical axis, and acts with the coil to move the lens holder in the direction of the optical axis. With a cap to which the magnet is fixed,
It is arranged between the upper stopper surface and the side stopper surface, and has a connecting portion for connecting the upper stopper surface and 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 greater than or equal to the distance between the side stopper surface and the side surface portion. apparatus.

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