JP2010066288A - Lens drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens drive device which can appropriately magnetically drive a moving body in an optical axis direction of a lens by utilizing the fact that two spring members are used maximally. <P>SOLUTION: In the lens drive device 1, a first type spring member having a large horizontal spring constant is used as a first spring member 14x where an imaging device is arranged. Therefore, the deterioration of image quality is prevented even if an external force in a direction orthogonal to the optical axis direction L is applied to the moving body 3. A clearance in a radial direction is made larger at a subject side more than at the imaging device side between a supporting body 2 and the moving body 3. Therefore, even if the subject side of the moving body 3 is shaken in a direction orthogonal to an optical axis, unwanted interference is not caused between the moving body 3 and the supporting body 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lens driving device in which a coil is held by a moving body having a lens.

A lens driving device mounted on a camera-equipped mobile phone, a digital camera, or the like includes a support, a moving body including a lens, a magnetic drive mechanism that magnetically drives the moving body in the lens optical axis direction, and the support and movement And a spring member connected to the body, and the moving body is driven in the optical axis direction by using the thrust by the magnetic drive mechanism and the biasing force of the spring member. Here, as the spring member, a first spring member disposed on the imaging element side in the lens optical axis direction and a second spring member disposed on the subject side with respect to the first spring member are used. The first spring member and the second spring member have the same basic configuration, and the same spring member is used for the longitudinal spring constant in the lens optical axis direction and the lateral spring constant in the direction orthogonal to the lens optical axis direction. (See Patent Document 1).
JP 2006-201525 A

  The first spring member and the second spring member used in such a lens driving device are required to have a constant spring constant over a wide deformation range in the lens optical axis direction as a longitudinal spring constant, and a lateral spring constant. However, it is difficult to satisfy both of these requirements with one type of spring member.

  In view of the above problems, an object of the present invention is to provide a lens driving device capable of suitably magnetically driving a moving body in the lens optical axis direction by making the best use of two spring members. It is to provide.

  In order to solve the above problems, in the present invention, a support, a moving body provided with a lens, a magnetic drive mechanism including a coil and a magnet for magnetically driving the moving body in the lens optical axis direction, and the support And a spring member connected between the movable body and a first spring member located on the imaging element side and a second spring member located on the subject side as the spring member, The lateral spring constant of the first spring member is larger than the lateral spring constant of the second spring member, and the radial clearance between the moving body and the support body is larger than that of the image sensor side. Large on the side.

  The present invention pays attention to the use of two spring members and is characterized in that the two spring members are configured differently to meet the demands required for the spring members. For this reason, the requirements that cannot be satisfied by one type of spring member, for example, the requirement that the lateral spring constant is large, and the requirement that the longitudinal spring constant is constant over a wide range in the lens optical axis direction are satisfied. Can do. In other words, in the present invention, when the blurring in the direction orthogonal to the optical axis on the imaging element side of the moving body is compared with the blurring in the direction orthogonal to the optical axis on the subject side of the moving body, the imaging element side Since the influence on the image quality has a greater influence on the image quality, the lateral spring constant of the first spring member arranged on the larger influence side is increased. Therefore, it is possible to suppress the influence on the image quality due to the blurring in the direction orthogonal to the optical axis of the moving body. In addition, since the second spring member has a small transverse spring constant, the moving body tends to shake in the direction perpendicular to the optical axis on the subject side, and thus the radial clearance is set between the moving body and the support body on the image sensor side. Is larger on the subject side. Therefore, even when the subject side of the moving body shakes in a direction perpendicular to the optical axis, useless interference does not occur between the moving body and the support.

  In the present invention, on the subject side between the moving body and the support body, a movement restricting portion is provided that restricts movement of the moving body in the radial direction over the entire moving range of the moving body in the optical axis direction. It is preferable that

  In the present invention, it is preferable that a spring member fixing portion that holds the second spring member on the support side and a portion that constitutes the movement restricting portion on the support side are arranged close to each other. In order for the second spring member to exhibit predetermined spring characteristics, it is important to prevent deformation of the second spring member in the vicinity of the connecting portion with the support, but the second spring member is held on the support side. If the spring member fixing portion to be arranged and the portion constituting the movement restricting portion on the support side are arranged close to each other, the second spring member can be prevented from being deformed in the vicinity of the connection portion with the support.

  In the present invention, it is preferable that the magnet is held on the support side, and a portion constituting the movement restricting portion on the support side is in contact with a subject side end surface in the optical axis direction of the magnet.

  In the present invention, the clearance is set to a dimension that can prevent the spring member from coming into contact with the magnet, the moving body, and the support when the moving body moves with respect to the support. It is preferable. With this configuration, even when the moving body is shaken in a direction perpendicular to the optical axis, the spring member does not interfere with the magnet, the moving body, and the support body, so that the second spring member is reliably prevented from being damaged such as plastic deformation. can do.

  In the present invention, when the blurring in the direction orthogonal to the optical axis on the imaging element side of the moving body is compared with the blurring in the direction orthogonal to the optical axis on the subject side of the moving body, Since blurring has a greater effect on image quality, the lateral spring constant of the first spring member arranged on the larger influence side is increased. Therefore, it is possible to suppress the influence on the image quality due to the blurring in the direction orthogonal to the optical axis of the moving body. In addition, since the second spring member has a small transverse spring constant, the moving body tends to shake in the direction perpendicular to the optical axis on the subject side, and thus the radial clearance is set between the moving body and the support body on the image sensor side. Is larger on the subject side. Accordingly, even when the subject side of the moving body is shaken in the direction orthogonal to the optical axis, useless interference does not occur between the moving body and the support body.

  The best mode for carrying out the present invention will be described below with reference to the drawings. The lens driving device described below can be attached to various electronic devices in addition to the camera-equipped mobile phone. For example, it can be used for a thin digital camera, PHS, PDA, bar code reader, surveillance camera, camera for checking the back of a car, a door having an optical authentication function, and the like.

(Entire configuration of lens driving device)
1A and 1B are an external view and an exploded perspective view, respectively, of a lens driving device to which the present invention is applied as viewed obliquely from above. FIG. 2 is an exploded perspective view in which the lens driving device to which the present invention is applied is disassembled more finely than the state shown in FIG. FIG. 3 is an explanatory diagram schematically showing an operation to which the present invention is applied. In FIG. 3, the lens and the lens holder are not shown.

  1A, 1B, 2 and 3, the lens driving device 1 according to the present embodiment is a thin camera used for a camera-equipped mobile phone or the like. For moving in both directions, the A direction (front side) approaching the subject (object side) and the B direction (rear side) approaching the opposite side (image side) from the subject, and has a substantially rectangular parallelepiped shape. ing. The lens driving device 1 generally includes a moving body 3 having a cylindrical lens holder 30 provided with one or more lenses 36 and a fixed stop inside, and moves the moving body 3 along the optical axis direction L. And the support 2 on which the magnetic drive mechanism 5 and the moving body 3 are mounted. The moving body 3 includes a cylindrical sleeve 13, and a cylindrical lens holder 30 is fixed to the inside thereof. Therefore, the outer shape of the moving body 3 is defined by the sleeve 13 and has a substantially cylindrical shape. Such a lens driving device 1 can be said to be a magnetic device including a magnetic driving mechanism 5.

  Here, the moving body 3 includes three lenses 36, and the lenses 36 are disposed at both ends of the moving body in the optical axis direction and at substantially the center position of the moving body. Among these, since the diameter of the lens arranged on the imaging element side is larger than the diameter of the other lenses, the moving body 3 has one of the lens optical axis directions in the optical axis direction of the moving body 3, In this embodiment, the center of gravity is located at a position biased toward the image sensor.

  The support 2 has a holder 19 (insulating member) made of a rectangular resin plate for holding an image sensor (not shown) on the image side, and a cap 16 and a box-like shape on the subject side. A yoke 18 and a spacer 11 are provided. In the center of the spacer 11, the cap 16, and the yoke 18, circular incident windows 110, 160, and 180 for taking light from the subject into the lens 36 are formed. The yoke 18 is made of a ferromagnetic plate such as a steel plate. As will be described later, the interlinkage magnetic field generator 4 that generates an interlinkage magnetic field in the first coil 31 and the second coil 32 held by the sleeve 13 together with the magnet 17. Is configured.

  The cap 16 is a metal press-processed product, and includes a top plate portion 165 and four side plate portions 161, 162, 163, and 164 bent from the top plate portion 165 toward the image sensor side. The side plate portions 161, 162, 163, 164 extend with substantially the same width as the side portions of the top plate portion 161.

(Configuration of magnetic drive mechanism 5)
The magnetic drive mechanism 5 includes a first coil 31 and a second coil 32 wound around the outer peripheral surface of the sleeve 13, and a linkage magnetic field generator 4 that generates a linkage magnetic field in the first coil 31 and the second coil 32. The magnetic drive mechanism 5 is configured by the first coil 31, the second coil 32, and the interlinkage magnetic field generator 4. The interlinkage magnetic field generator 4 includes four magnets 17 facing the first coil 31 and the second coil 32 on the outer peripheral side. The yoke 18 is also used as a component of the magnetic drive mechanism.

  The yoke 18 includes a top plate portion 185 that covers the upper surface side of the second coil 32 located on the subject side, and side plate portions 181, 182, 183, and 184 that cover the side surfaces of the first coil 31 and the second coil 32. The leakage flux from the magnetic path formed between the magnet 17 and the first coil 31 and the second coil 32 is reduced. With this configuration, the linearity between the amount of movement of the moving body 3 and the current flowing through the first coil 31 and the second coil 32 can be improved.

  In this embodiment, each of the four magnets 17 has a substantially triangular prism shape, and is fixed to the four corners of the inner peripheral surface of the yoke 18 in a state of being separated in the circumferential direction. All of the four magnets 17 are divided into two in the optical axis direction L, and in any case, the inner surface and the outer surface are magnetized to different poles. In the four magnets 17, for example, the inner surface is magnetized to the N pole in the upper half, the outer surface is magnetized to the S pole, and the inner surface is magnetized to the S pole in the lower half, and the outer surface is magnetized to the N pole. ing. Therefore, the winding direction of the coil wire is opposite between the first coil 31 and the second coil 32. As described above, if the magnet 17 is divided into four corners, a thin portion is generated in the magnet 17 even when the gap between the yoke 18 and the sleeve 13 is narrow in the central portion of the side portion of the yoke 18. This can be prevented, the strength of the magnet 17 can be increased, and the magnetic force of the magnet 17 can be efficiently applied to the first coil 31 and the second coil 32 mounted on the moving body 3. In addition, by effectively using the four corner spaces between the moving body 3 and the yoke 18 as the arrangement space for the magnets 17, the entire lens driving device 1 can be reduced in size.

(Configuration of spring member and its surroundings)
The lens driving device 1 according to the present embodiment further includes a support 2 and a moving body 3 between the holder 19 and the sleeve 13 (on the imaging element side) and between the spacer 11 and the sleeve 13 (on the subject side). The first spring member 14x and the second spring member 14y are connected to each other. Both the first spring member 14x and the second spring member 14y are made of metal such as beryllium copper or SUS steel, and are formed by pressing a thin plate having a predetermined thickness or etching using a photolithography technique. is there.

  Although detailed configurations of the first spring member 14x and the second spring member 14y will be described later, the first spring member 14x is connected to the holder 19 and the sleeve 13, and the movable body 3 can be moved along the lens optical axis. It is set as the state supported by the support body 2. The second spring member 14y is connected to the spacer 11 and the sleeve 13, and the movable body 3 is supported by the support body 2 so as to be movable along the lens optical axis.

  Of the first spring member 14x and the second spring member 14y, the first spring member 14x disposed on the holder 19 side is divided into two spring pieces 14a and 14b. As will be described in detail later, Two ends of the first coil 31 and the second coil 32 (winding end and winding end) are connected to the spring pieces 14a and 14b, respectively. Accordingly, the first spring member 14 x (spring pieces 14 a and 14 b) also functions as a power supply member for the first coil 31 and the second coil 32.

  The spring pieces 14a and 14b can be bent and pulled out to the outside of the support 2 to be used for electrical connection with the outside. However, in this embodiment, as will be described in detail later, terminals 12x and 12y separate from the spring pieces 14a and 14b are fixed to the holder 19.

  In this embodiment, the magnetic drive mechanism 5 further includes a ring-shaped magnetic piece 130 held at the upper end of the sleeve 13, and the magnetic piece 130 is attracted by the attractive force acting between the magnet 17. An urging force in the optical axis direction L is applied to the moving body 3. For this reason, since it is possible to prevent the mobile body 3 from being displaced by its own weight when no current is applied, it is possible to maintain the mobile body 3 in a desired posture and to further improve the impact resistance. Further, the magnetic piece 130 acts as a kind of back yoke, and can reduce leakage magnetic flux from a magnetic path formed between the magnet 17 and the first coil 31 and the second coil 32. In addition, as a magnetic piece, a rod-shaped magnetic body may be used.

  The spacer 11 is attached to the inner surface of the top plate portion 185 of the yoke 18, and an incident window 110 is formed at the center. Small protrusions 112 (see FIG. 6) are formed at the four corners of the plate portion 115 so as to protrude to the opposite side to the subject side.

  The holder 19 is formed with small protrusions 192 extending toward the subject at its four corners. The small protrusion 192 of the holder 19 and the small protrusion 112 of the spacer 11 are used when the first spring member 14x and the second spring member 14y are connected to the support 2 respectively.

  A plurality of stepped protrusions 13y for connecting the second spring member 14y are formed in the circumferential direction on the upper end surface (end surface on the subject side) of the sleeve 13, and the lower end surface (end surface on the image sensor side) of the sleeve 13 is formed. ), A plurality of small protrusions 13x for connecting the first spring members 14x are formed in the circumferential direction.

(Basic operation)
In the lens driving device 1 according to the present embodiment, the moving body 3 is normally located on the image sensor side (image side). When flowing, the first coil 31 and the second coil 32 receive an upward (front) electromagnetic force. As a result, the sleeve 13 to which the first coil 31 and the second coil 32 are fixed starts to move toward the subject (front side / direction indicated by the arrow A). At this time, elastic forces that restrict the movement of the sleeve 13 are generated between the second spring member 14y and the front end of the sleeve 13 and between the first spring member 14x and the rear end of the sleeve 13, respectively. For this reason, when the electromagnetic force that attempts to move the sleeve 13 to the front side and the elastic force that restricts the movement of the sleeve 13 are balanced, the sleeve 13 stops. At this time, the sleeve 13 (the moving body 3) is adjusted by adjusting the amount of current flowing through the first coil 31 and the second coil 32 according to the elastic force acting on the sleeve 13 by the first spring member 14x and the second spring member 14y. ) Can be stopped at a desired position.

  In this embodiment, since the first spring member 14x and the second spring member 14y are plate springs (gimbal springs) in which a linear relationship is established between the elastic force (stress) and the displacement amount (distortion amount), Linearity between the amount of movement of the sleeve 13 and the current passed through the first coil 31 and the second coil 32 can be improved. In addition, since two spring members including the first spring member 14x and the second spring member 14y are used, a large balance force is applied in the direction of the optical axis when the sleeve 13 is stopped. Even if other forces such as centrifugal force and impact force act in the direction of, the sleeve 13 can be stopped more stably. Further, in the lens driving device 1, the sleeve 13 is not stopped by colliding with a collision material (buffer material) or the like, but is stopped using a balance between electromagnetic force and elastic force. Therefore, it is possible to prevent the occurrence of a collision sound.

[Configuration of coil]
4A, 4 </ b> B, 4 </ b> C, and 4 </ b> D are cross-sectional views in a state where the first coil 31 and the second coil 32 are wound around the sleeve 13 in the lens driving device 1 to which the present invention is applied. They are a perspective view of a sleeve, a perspective view when the sleeve is viewed from the opposite side, and a plan view of the sleeve.

  As described with reference to FIGS. 1 to 3, the sleeve 13 is a coil wound body in which the first coil 31 and the second coil 32 are wound on the outer peripheral surface, and includes the first coil 31 and the second coil 31. In the coil 32, the winding direction of the coil wire is opposite. In adopting such a configuration, in the present embodiment, annular rib-shaped protrusions 136 and 137 are formed on the outer peripheral surface of the sleeve 13 at the image sensor side end and the subject side end, and the rib shape. An annular rib-shaped protrusion 138 is formed at a position slightly shifted to the subject side from the intermediate position sandwiched between the protrusions 136 and 137. Therefore, on the outer peripheral surface of the sleeve 13, the first coil winding surface 131 is formed in the portion sandwiched between the rib-like projections 136, 138, and the second coil winding is formed in the portion sandwiched between the rib-like projections 137, 138. A turning surface 132 is formed. The second coil winding surface 132 has a narrower width dimension (interval between rib-shaped projections) in the optical axis direction L and a smaller outer diameter than the first coil winding surface 131.

  Of the rib-shaped protrusions 136, 137, and 138, the rib-shaped protrusion 137 formed at the end on the subject side is connected in the circumferential direction. On the other hand, the rib-shaped protrusion 136 on the image sensor side has a pair of discontinuous portions on the opposite side across the optical axis, and one of the pair of discontinuous portions is used as the coil winding start portion 136a. The other interrupted portion is used as the coil winding end portion 136b. The rib-shaped protrusion 136 is formed with protrusions 136e, 136f, 136g, and 136h protruding toward the outer peripheral side at equal angular intervals, and the protrusions 136e and 136g are respectively a coil winding start portion 136a and a coil winding end portion 136b. Is adjacent on the counterclockwise CCW side.

  In addition, the intermediate rib-like protrusion 138 is also formed with a pair of interrupted portions on the opposite side across the optical axis, and the pair of interrupted portions are formed by connecting the coil wire to the first coil winding surface 131 and the second coil winding. It is used as coil turn-back portions 138a and 138b for moving the winding position between the winding surface 132 and reversing the winding direction of the coil wire. On the rib-like protrusion 138, protrusions 138e, 138f, 138g, and 138h protruding toward the outer peripheral side are formed at equal angular intervals. The protrusion 138e is adjacent to the coil return portion 138a on the counterclockwise CCW side, and the protrusion 138g is adjacent to the coil return portion 138b on the clockwise CW side. The projections 138e and 138g function as coil locking portions that hook the coil wires when the coil wires are folded back by the folded portions 138a and 138b together with the ends of the rib-shaped projections 138. The coil locking portion may be any protrusion that protrudes radially outward from the outer peripheral surface of the sleeve 13. For example, when the protrusions 138 e and 138 g are not formed, the first coil winding surface 131 and the second coil winding portion 131 In the rib-like projection 138 that separates the coil winding surface 132, an end portion of the rib-like projection 138 formed by the interrupted portion may be used as a coil locking portion.

  In the sleeve 13 configured as described above, the protrusions 138e, 138f, 138g, and 138h formed in the middle protrude outward in the radial direction as compared with the protrusions 136e, 136f, 136g, and 136h formed on the imaging element side. Yes. As will be described later, the protrusions 138e to 138h are located between the magnets 17 adjacent in the circumferential direction. Further, the protrusions 136 e to 136 h formed on the outer peripheral surface of the sleeve 13 are positioned inside a recess 191 a formed on the inner surface of the side wall 191 of the holder 19. Accordingly, the intermediate protrusions 138e, 138f, 138g, and 138h, and the protrusions 136e, 136f, 136g, and 136h on the imaging element side are interference protrusions that restrict the rotation range of the moving body 3 or restrict the movement in the radial direction, respectively. Also works.

  In the sleeve 13 of this embodiment, the first coil winding surface 131 and the second coil winding surface 132 have different outer diameters, and the second coil winding surface 132 has an outer diameter of the first coil winding surface. The outer diameter dimension of the surface 131 is smaller. In other words, a plurality of lenses 36 are held inside the sleeve 13 via the lens holder 30, but among the plurality of lenses 36, a lens positioned on the image sensor side as the number of pixels increases. Is set larger than the lens located on the subject side. For this reason, since the outer diameter of the lens holder 30 is large on the image sensor side and small on the subject side, the inner diameter of the sleeve 13 is also large on the image sensor side and small on the subject side. Therefore, the outer diameter dimension of the second coil winding surface 132 is smaller than the outer diameter dimension of the first coil winding surface 131.

  In winding the coil wire around the sleeve 13, in this embodiment, first, as shown by an arrow C1, the coil wire is wound from the winding start portion 136a to the first coil winding surface 131 in an odd number of layers and clockwise CW. To do. At this point, since the end of the coil wire is near the coil turn-back portion 138a, when the coil wire is passed through the coil turn-back portion 138a as shown by the arrow C2, the winding direction of the coil wire is changed by hooking the root of the protrusion 138e. Invert. Then, the coil wire is wound on the second coil winding surface 132 in an even number of layers counterclockwise CCW. Meanwhile, the coil wire reciprocates on the coil winding surface 132, so that the end of the coil wire reaches the vicinity of the intermediate rib-shaped protrusion 138. Next, as shown by an arrow C3, when the coil wire is passed through the coil turn-back portion 138b, the coil wire is hooked on the base of the protrusion 138g to reverse the winding direction of the coil wire. Then, the coil wire is wound around the first coil winding surface 131 by an odd number of layers in the clockwise direction CW. As a result, the end of the coil wire reaches the vicinity of the rib-like protrusion 136, and therefore the coil wire is pulled out from the coil winding end portion 136b as indicated by an arrow C4. Note that the winding start end and the winding end end of the coil wire are connected to the spring pieces 14a and 14b of the first spring member 14x described with reference to FIGS.

  During such winding, the coil wire is aligned and wound around the first coil winding surface 131 and the second coil winding surface 132. In addition, the number of coil winding layers on the first coil winding surface 131 and the second coil winding surface 132 is 8 or less, and the wire diameter of the coil wire is 0.04 including the winding insulating layer. It is in the range of ~ 0.08 mm.

  Further, in this embodiment, the first coil winding surface 131 and the second coil winding surface 132 have different outer diameter dimensions, and among the first coil winding surface 131 and the second coil winding surface 132, In the winding surface with a small outer diameter, the number of coil winding layers is set larger than that of a winding surface with a large outer diameter. That is, in this embodiment, the second coil winding surface 132 with a small outer diameter dimension has a larger number of coil winding layers than the first coil winding surface 131 with a large outer diameter dimension. In particular, in the present embodiment, the second coil winding surface 132 having a small outer diameter dimension is compared with the first coil winding surface 131 having a large outer diameter dimension by a coil winding layer corresponding to the difference in outer diameter dimension. There are many. For this reason, the outer diameter dimension of the sleeve including the coil is equal in the portion corresponding to the first coil winding surface 131 and the portion corresponding to the second coil winding surface 132. For this reason, the number of winding layers of the coil wire can be increased without increasing the maximum outer diameter of the entire sleeve 13 including the first coil 31 and the second coil 32.

  As described above, in this embodiment, the winding order of the coil wires and the number of winding layers are optimized in the first coil winding surface and the second coil winding surface, and therefore the first coil winding surface 131 or the second coil winding surface is optimized. There is no crossover that runs through the coil winding surface 132 at all. Therefore, since the outer diameter occupied by the conventional connecting wire can be used for winding the coil, the number of winding layers of the coil can be increased without increasing the outer diameter. Moreover, since the coil wire is wound in an aligned manner, the number of turns of the coil wire can be increased without increasing the outer diameter.

  In particular, in this embodiment, since the number of coil winding layers on the first coil winding surface 131 and the number of coil winding layers on the second coil winding surface 132 are all as small as eight layers or less, there is no crossover. The number of winding layers of the coil wire can be increased by one layer, that is, the number of winding layers can be increased by 10% or more. In addition, in this embodiment, the wire diameter of the coil wire is in the range of 0.04 to 0.08 mm including the winding insulation layer, and is thin, so if there is a crossover wire, the coil wire is easily cut. Since there is no connecting wire, the coil is not cut due to the connecting wire during winding.

  Moreover, since the coil winding start part 136a and the coil winding end part 136b are located on the opposite side, the moving body is compared with the case where the coil winding start part 136a and the coil winding end part 136b are adjacent in the circumferential direction. 3 symmetry can be ensured. Therefore, the moving body 3 can move in the optical axis direction L in a stable posture without tilting.

(Detailed configuration of spring member)
With reference to FIG. 5, the configuration of the spring members (first spring member 14x and second spring member 14y) used in the lens driving device to which the present invention is applied will be described. FIG. 5 is a perspective view of the first spring member 14x and the second spring member 14y used in the lens driving device 1 to which the present invention is applied.

  In this embodiment, the spring force of the spring member is used. Therefore, the first spring member 14x and the second spring member 14y have a constant spring constant in a wide deformation range in the lens optical axis direction L as a longitudinal spring constant, that is, the sleeve 13 extends in the optical axis direction L. The spring force generated by the first spring member 14x and the second spring member 14y when moved is required to be constant, and the lateral spring constant is large, that is, the moving body 3 is orthogonal to the optical axis. It is required not to deviate in the direction. However, it is difficult to satisfy both of these requirements with one type of spring member. Therefore, in this embodiment, the configuration described below is adopted.

  As shown in FIG. 5, the first spring member 14x on the imaging element side includes four support-side connecting portions 149 held by the support 2 (holder 19) and a circle fixed to the moving body 3 (sleeve 13). An annular moving body side connecting portion 148 and four leaf spring-shaped arm portions 141 connecting the supporting body side connecting portion 149 and the moving body side connecting portion 148 are provided. A small hole 148 a for connection with the lower end portion of the sleeve 13 is formed in the moving body side connection portion 148, and a small hole 149 a for connection with the holder 19 is formed in the support body side connection portion 149. Here, the arm portion 141 extends in an arc shape in the circumferential direction and does not include a meandering portion that is folded back in the radial direction.

  The first spring member 14 x is divided into two spring pieces 14 a and 14 b and is used as a power supply member for the first coil 31 and the second coil 32. Accordingly, both end portions (winding start end portion and winding end end portion) of one coil wire constituting the first coil 31 and the second coil 32 are the ends of the moving body side connecting portion 148 of the two spring pieces 14a and 14b. It is connected to the part 148e by a method such as soldering.

  However, the first spring member 14x is connected to the spring pieces 14a and 14b through a frame portion 140 indicated by a one-dot chain line until the middle of manufacture, and is attached to the two spring pieces 14a and 14b during the assembly to the lens driving device 1. Divided. For this reason, the spring pieces 14a and 14b are provided with separation points 141a and 141b from the frame part 140, and the separation point 141a is wider than the separation point 141b. As described later, the wide cut-off portion 141a is used as a connected portion by soldering with the terminals 12x and 12y.

  The second spring member 14y on the subject side includes four support body side connection portions 143 held by the support body 2 (spacer 11), an annular frame-like moving body side connection portion 144 connected to the upper end of the sleeve 13, and Four arm portions 145 that connect the support body side connection portion 143 and the moving body side connection portion 144 are provided. Each of these four arm portions 145 extends from the connecting portion with the moving body side connecting portion 144 to the moving body side connecting portion 143 with a meandering portion 145a that is bent while being curved toward the outer peripheral side. The movable body side connecting portion 144 is formed with a notch 144a for connection with the upper end portion of the sleeve 13, and the support body side connecting portion 143 is formed with a small hole 143a for connection with the spacer 11. Yes.

  Thus, in this embodiment, paying attention to the use of two spring members (the first spring member 14x and the second spring member 14y), the two spring members are configured differently to obtain the spring member. It is characterized by responding to the demands. That is, in this embodiment, as the first spring member 14x, a first type spring member in which the arm portion 141 does not have a meandering portion and extends in an arc shape in the circumferential direction is used. Although it is difficult to extend the arm portion 141 further in order to make the longitudinal spring constant constant over a wide deformation range in the optical axis direction L, there is an advantage that the lateral spring constant is large. On the other hand, as the second spring member 14y, a second type spring member in which the arm portion 145 extends in the circumferential direction with a meandering portion 145a is used, and the second type spring member has a small lateral spring constant. However, since the arm portion 145 has the meandering portion 145a, there is an advantage that the longitudinal spring constant is constant over a wide deformation range in the lens optical axis direction L. Therefore, according to the present embodiment, there is a demand for a large lateral spring constant that cannot be satisfied by one type of spring member, and a demand for a constant longitudinal spring constant over a wide range in the lens optical axis direction L. Can be met. Therefore, by realizing a sufficient level of lateral spring constant, it is possible to prevent the moving body 3 from shifting in the lateral direction and to make the longitudinal spring constant constant over a wide displacement range in the optical axis direction L.

  In this embodiment, a first type spring member having a large lateral spring constant is used as the first spring member 14x on which the image sensor is arranged. For this reason, even when an external force in a direction orthogonal to the optical axis direction L is applied to the moving body 3, it is possible to prevent the image quality from being deteriorated. That is, in the small lens driving device 1, the blurring in the direction orthogonal to the optical axis on the imaging element side of the moving body 3 is compared with the blurring in the direction orthogonal to the optical axis on the subject side of the moving body 3. In this case, the blur on the image sensor side has a larger influence on the image quality. However, in this embodiment, the lateral spring constant of the first spring member 14x arranged on the larger influence side is increased. Can be kept small.

  In the first spring member 14x and the second spring member 14y used in the present embodiment, the four arm portions are formed so as to be substantially rotationally symmetric so as to extend in the same direction. You may employ | adopt the structure etc. in which two are formed in line symmetry.

(Radial clearance between moving body and fixed body)
FIGS. 6A and 6B are a perspective view of the spacer 11 used in the lens driving device to which the present invention is applied as viewed obliquely from below, and an explanatory view showing the positional relationship between the spacer and the sleeve.

  In the present embodiment, a first type spring member having a large lateral spring constant is used as the first spring member 14x on which the image sensor is disposed, and a second type having a small lateral spring constant is used as the second spring member 14y on the subject side. The spring member is used. For this reason, the moving body 3 greatly shakes in the radial direction on the subject side. Therefore, in this embodiment, as described below, the radial clearance between the support 2 and the moving body 3 is larger on the subject side than on the image sensor side.

  First, on the image sensor side, the clearance G1 (see FIG. 3) between the support 2 and the moving body 3 is the protrusions 136e, 136f, 136g, 136h of the sleeve 13 shown in FIGS. It is defined by the radial dimension between the inner surface of the side wall 191 and the radial direction. Further, in the intermediate portion between the image sensor side and the subject side, the clearance G2 (see FIG. 3) between the support 2 and the moving body 3 is the protrusions 138e, 138f, 138g of the sleeve 13 shown in FIGS. 138 h and the radial dimension between the inner side surfaces of the side plate portions 181, 182, 183, and 184 of the yoke 18.

  On the subject side, the clearance G3 (see FIG. 3) between the support 2 and the moving body 3 is determined by the radial gap between the sleeve 13 and the columnar protrusion 119 that protrudes toward the image sensor side in the spacer 11. It is prescribed.

  The configuration of the clearance G3 will be described in detail with reference to FIGS. 6 (a) and 6 (b). As shown in FIGS. 6A and 6B, the bottom surface of the spacer 11 has small holes formed in the support-side connecting portion 143 of the second spring member 14y in the spring member fixing portions 114 having thick corners. A small protrusion 112 that fits into 143a is formed. A columnar protrusion 119 that protrudes toward the image sensor is formed on the lower surface of the spacer 11 at a position close to the spring member fixing portion 114 in which the small protrusion 112 is formed in the clockwise CW direction. In addition, the lower end surface of the columnar protrusion 119 is in contact with the subject-side end surface of the magnet 17 to position the magnet 17 with the holder 19.

  Here, the inner surface 119a of the columnar protrusion 119 is a curved surface when viewed from the optical axis direction L. On the other hand, the outer peripheral surface of the annular rib-shaped protrusion 137 of the sleeve 13 is opposed to the inner surface 119a of the columnar protrusion 119 via a predetermined gap on the inner side in the radial direction. A clearance G3 between the support 2 and the moving body 3 on the side is defined. Accordingly, the columnar protrusion 119 functions as a movement restricting portion that restricts movement of the moving body 3 in the radial direction. As described above, in the present embodiment, in the spacer 11, the spring member fixing portion 114 that supports the second spring member 14 y and the columnar protrusion 119 that restricts the movement of the moving body 3 in the radial direction are disposed close to each other.

The clearances G1, G2, and G3 set in this way have the following relationship: G1 ≦ G2 <G3
The clearance in the radial direction between the support 2 and the moving body 3 is larger on the subject side than on the image sensor side. Therefore, even when the subject side of the moving body 3 is shaken in the direction perpendicular to the optical axis, useless interference does not occur between the moving body 3 and the support 2.

  In this embodiment, the clearances G1, G2, and G3 indicate that the first spring member 14x and the second spring member 14y come into contact with the magnet 17 and the moving body 3 when the moving body 3 moves with respect to the support body 2. The dimensions are set to avoid this. For this reason, even when the moving body 3 shakes in the direction perpendicular to the optical axis, the first spring member 14x and the second spring member 14y do not interfere with any of the magnet 17, the support body 2, and the moving body 3. Breakage such as plastic deformation of the first spring member 14x and the second spring member 14y can be reliably prevented.

  In addition, the columnar protrusion 119 has a function of projecting from the lower surface of the spacer 11 toward the image sensor and positioning the magnet 17 between the columnar protrusion 119 and the holder 19. Further, the columnar protrusion 119 has a sufficient projecting dimension from the lower surface of the spacer 11 toward the image sensor, and the outer peripheral surface of the rib-shaped protrusion 137 of the sleeve 13 in a state where the moving body 3 is located closest to the image sensor. Is opposed to the lower end of the inner surface 119a of the columnar protrusion 119. For this reason, even if the moving body 3 moves to any position in the optical axis direction L, the outer peripheral surface of the rib-shaped protrusion 137 of the sleeve 13 faces the inner surface 119a of the columnar protrusion 119. Therefore, even if the movable body 3 moves to any position in the optical axis direction L, the movement of the movable body 3 in the radial direction is limited by the spacer 11. Moreover, since the spring member fixing portion 114 and the columnar protrusion 119 are disposed close to each other in the spacer 11, the second spring member 14y always exhibits desired spring characteristics. That is, in order for the second spring member 14y to exhibit desired spring characteristics, it is important to prevent deformation of the second spring member 14y in the vicinity of the connecting portion with the support 2 side (spacer 11 side). However, if the spring member fixing portion 114 and the columnar protrusion 119 are arranged close to each other as in this embodiment, the second spring member 14y is deformed near the connection portion with the support 2 side (spacer 11 side). Can be reliably prevented. In particular, in this embodiment, in the second spring member 14y, an S-shaped meandering portion 145a is formed in the vicinity of the connecting portion with the support 2 side (spacer 11 side), and the magnet 17 is provided in the vicinity thereof. Although the spring member fixing portion 114 and the columnar protrusion 119 are arranged close to each other, even when the moving body 3 is displaced in the radial direction, the meandering portion 145a of the second spring member 14y and the magnet 17 Contact can be reliably prevented.

  In this embodiment, the protrusions 138e to 138h formed on the outer peripheral surface of the sleeve 13 are positioned between the four magnets 17 arranged in the circumferential direction. Further, the protrusions 136 e to 136 h formed on the outer peripheral surface of the sleeve 13 are positioned inside a recess 191 a formed on the inner surface of the side wall 191 of the holder 19. Accordingly, when the moving body 3 is displaced in a direction (radial direction or circumferential direction) orthogonal to the optical axis direction L due to an impact or the like, the protrusions 138e to 138h abut against the magnet 17, and the rotation range of the moving body 3 is restricted. It also functions as an interference convex portion that restricts movement in the radial direction. Further, when the moving body 3 is displaced in a direction (radial direction) orthogonal to the optical axis direction L due to an impact or the like, the protrusions 136e to 136h abut against the side wall portion 191 of the holder 19, and the moving body 3 moves in the radial direction. It also functions as an interference convex portion for restricting movement. Moreover, if the projecting portions 136e to 136h and 138e to 138h are interference convex portions, the movable body 3 is moved in the optical axis direction L by an impact or the like even if the movable body 3 moves to any position in the optical axis direction L. When it is displaced in a direction orthogonal to the side wall 191 of the holder 19 and the magnet 17. Therefore, even if the movable body 3 moves to any position in the optical axis direction L, the displacement of the movable body 3 in the radial direction can be reliably prevented.

[Configuration of Terminal 12]
FIG. 7 is a perspective view showing a state in which the terminals 12x and 12y and the first spring member 14x are attached to the holder 19 in the lens driving device to which the present invention is applied. FIG. 8 is a perspective view showing a state in which the holder 19, the terminals 12x and 12y, and the first spring member 14x are separated in the lens driving device to which the present invention is applied.

  In this embodiment, when energizing the first coil 31 and the second coil 32, both end portions (winding start end portion and winding end end portion) of the coil wire are connected to the end portions 148e of the spring pieces 14a and 14b shown in FIGS. ) Are connected by a method such as soldering, and terminals 12x and 12y separate from the spring pieces 14a and 14b are used.

  The terminals 12x and 12y are an external connection terminal portion 121 located outside the holder 19 (insulating member) and an internal connection terminal portion electrically connected to the disconnecting portion 141a (connected portion) of the spring pieces 14a and 14b. 123, and a routing portion 122 extending from the external connection terminal portion 121 along the side wall portion 191 (inner wall) of the holder 19 to reach the internal connection terminal portion 123. The terminals 12x and 12y have a portion extending downward from one end of the routing portion 122 as an external connection terminal portion 121. The leading end of the routing portion 122 is bent at two locations along the side wall portion 191 of the holder 19. The portion is an internal connection terminal portion 123. The terminals 12x, 12y having such a structure are metal plates that have been punched and bent by pressing or the like, and the optical axis direction L is in the surface direction, in other words, the thickness direction is in the radial direction. Is held by the holder 19.

  In the holder 19, a through hole 194 through which the external connection terminal portion 121 penetrates from the inside to the outside of the holder 19 is formed at a corner portion where the bottom wall portion 190 and the side wall portion 191 are connected. Further, in the side wall portion 191 of the holder 19, a notch 191 c is formed at a position where the internal connection terminal portion 123 is located, and the internal connection terminal portion 123 enters the notch 191 c and enters the side wall portion 191. It is in contact with the end of the. A flat seat portion 196 is formed in a portion corresponding to the notch 191c on the bottom plate portion 190 of the holder 19, and the separating portion 141a of the spring pieces 14a and 14b is placed on the upper surface of the seat portion 196. . Further, the seat portion 196 extends to the vicinity of the adjacent side wall portion 191, and a slit-like groove 195 is formed between the end portion of the seat portion 196 and the side wall portion 191. Therefore, the terminals 12x and 12y can be fixed to the holder 19 in a state where the routing portions 122 of the terminals 12x and 12y are inserted into the grooves 195. In this embodiment, the external connection terminal portions 121 of the terminals 12 x and 12 y are press-fitted into the through holes 194 of the holder 19, and the routing portions 122 of the terminals 12 x and 12 y are press-fitted into the grooves 195 of the holder 19. For this reason, the terminals 12 x and 12 y can be easily and reliably fixed to the holder 19.

  When the terminals 12x and 12y are fixed to the holder 19 in this way and the separation portion 141a of the spring pieces 14a and 14b is placed on the seat portion 196, the separation portion between the internal connection terminal portion 123 and the spring pieces 14a and 14b is obtained. 141a is a posture in which the surfaces are orthogonal to each other. Further, the internal connection terminal portion 123 and the separation portion 141a of the spring pieces 14a and 14b are in a state of being separated by a narrow gap in the optical axis direction L. In such a state, the surfaces of the internal connection terminal portion 123 and the cut portions 141a of the spring pieces 14a and 14b are soldered to each other. At that time, a soldering iron is inserted from the notch 191c from the outside.

  Thus, in this embodiment, since the spring pieces 14a and 14b and the terminals 12x and 12y are separate bodies, the spring pieces 14a and 14b are never deformed even when the bent portions are provided on the terminals 12x and 12y. Further, even when an external force is applied to the external connection terminal 121, the external force is not transmitted to the spring portions of the spring pieces 14a and 14b because the long lead-out portion 122 is present. Therefore, it is possible to reliably prevent the spring portions of the spring pieces 14a and 14b from being deformed by an external force. Therefore, a change in the spring constant due to the deformation of the spring members 14x and 14y can be prevented, so that the moving body 3 using the thrust by the magnetic drive mechanism 5 and the urging force of the spring members 14x and 14y can be prevented. Driving can be suitably performed. In addition, since the routing portion 122 extends along the inner wall of the holder 19, there is no problem such as contact with the spring pieces 14a and 14b even if the routing portion 122 is long.

  Further, the external connection terminal portions 121 of the terminals 12x and 12y pass through the through hole 194 of the holder 19 and are drawn out to the outside. For this reason, as compared with the configuration in which the external connection terminal portion 121 is pulled out along the outer surface of the holder 19, the lens drive is performed by the amount that the external connection terminal portion 121 can be pulled out using the meat portion of the holder 19. The apparatus 1 can be reduced in size.

  Moreover, since the external connection terminal portion 121 is press-fitted into the through hole 194, even when an external force is applied to the external connection terminal portion 121, the external force is not transmitted to the spring pieces 14a and 14b. Further, since the routing portion 122 of the terminals 12x and 12y is press-fitted into the slit-shaped groove 195, it is firmly fixed. For this reason, even when an external force is applied to the external connection terminal portion 121, the external force is not transmitted to the spring pieces 14a and 14b. Therefore, deformation of the spring pieces 14a and 14b can be reliably prevented.

  Moreover, in this embodiment, the cut-off portion 141a of the spring pieces 14a and 14b is placed on the seat 196. Further, among the disconnecting portions 141a and 141b of the spring pieces 14a and 14b, the wide disconnecting portion 141a is used as a connected portion of the terminals 12x and 12y. For this reason, it is easy to perform the soldering operation and can be surely soldered.

  Furthermore, the cut-off portions 141a of the spring pieces 14a and 14b and the internal connection terminal portions 123 of the terminals 12x and 12y are solder-connected to each other at right angles to each other. Therefore, even if the area that the soldering area occupies in plan is small, a sufficiently wide soldering area can be secured for both the spring pieces 14a and 14b and the terminals 12x and 12y. Further, a gap in the optical axis direction L exists between the cut-off portion 141a of the spring pieces 14a and 14b and the internal connection terminal portion 123 of the terminals 12x and 12y, and the gap is filled with solder. For this reason, there is an advantage that a fillet having an appropriate shape can be formed in the soldered portion and the solder does not spread to an extra area.

  The configuration in which the external connection terminal portion 121 is press-fitted into the through hole 194 and the lead-out portion 122 is press-fitted into the slit-shaped groove 195, even when the terminals 12x and 12y are made of part of the spring members 14x and 14y, There is an effect that an external force applied to the external connection terminal portion 121 can be prevented from being transmitted to the spring portions of the spring pieces 14a and 14b.

(A), (b) is the external view which looked at the lens drive device to which this invention is applied from diagonally upward, and an exploded perspective view, respectively. It is the disassembled perspective view which decomposed | disassembled further finely the lens drive device to which this invention is applied. It is explanatory drawing which shows typically the operation | movement to which this invention is applied. (A), (b), (c), (d) is a sectional view of the lens drive device to which the present invention is applied, in which the first coil and the second coil are wound around the sleeve, and a perspective view of the sleeve, It is the perspective view when a sleeve is seen from the other side, and the top view of a sleeve. It is a perspective view of the spring member (the 1st spring member and the 2nd spring member) used for the lens drive device to which the present invention is applied. (A), (b) is the perspective view when the spacer 11 used for the lens drive device to which this invention is applied is seen from diagonally downward, and explanatory drawing which shows the positional relationship of a spacer and a sleeve. In the lens drive device to which this invention is applied, it is a perspective view which shows a mode that the terminal and the 1st spring member were attached to the holder. In the lens drive device to which this invention is applied, it is a perspective view of the state which isolate | separated the holder, the terminal, and the 1st spring member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens drive device 2 Support body 3 Moving body 5 Magnetic drive mechanism 11 Spacer 12x, 12y Terminal 13 Sleeve (coil winding body)
14a, 14b Spring piece 14x First spring member 14y Second spring member 16 Cap 17 Magnet 18 Yoke 19 Holder (insulating member)
31 First coil 32 Second coil 36 Lens

Claims (5)

A support, a moving body including a lens, a magnetic drive mechanism including a coil and a magnet for magnetically driving the moving body in the lens optical axis direction, and a spring connected between the support and the moving body A lens driving device having a member,
As the spring member, a first spring member located on the image sensor side, and a second spring member located on the subject side,
The lateral spring constant of the first spring member is greater than the lateral spring constant of the second spring member;
A lens driving device characterized in that a radial clearance between the moving body and the support is larger on the subject side than on the imaging element side.   Between the moving body and the support body, on the subject side, there is configured a movement restricting section for restricting movement of the moving body in the radial direction over the entire moving range of the moving body in the optical axis direction. The lens driving device according to claim 1.   The spring member fixing portion that holds the second spring member on the support side and the portion that constitutes the movement restriction portion on the support side are disposed close to each other. Lens drive device. The magnet is held on the support side,
4. The lens driving device according to claim 3, wherein a portion constituting the movement restricting portion on the support side is in contact with a subject-side end surface in the optical axis direction of the magnet.   The clearance is set to a dimension that can prevent the spring member from coming into contact with the magnet, the moving body, and the support when the moving body moves with respect to the support. The lens driving device according to claim 4.

Images