JP2009109583A - Lens drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens drive device for preventing deterioration of processability or productivity. <P>SOLUTION: The lens drive device has: a sleeve 13 holding a lens and moving in an optical axis L direction; a support (yoke 11 or the like) supporting the sleeve 13 to be movable in the optical axis L direction; a magnetic drive mechanism equipped with a coil 18 and a magnet 17 and driving the sleeve 13 in the optical axis L direction; and a first leaf spring 14 and a second leaf spring 15 arranged between the sleeve 13 and the support, and regulating the movement of the sleeve 13 in the optical axis L direction. The support is equipped with a holder 30 in which a spring member is fixed, and the yoke 11 covering at least a part of the outer periphery of the magnet 17. A case body 20 of the holder 30 covering at least a part of the periphery of the spring member is constituted separately from a bottom member 19 covering at least a part of the end face of the spring member in the optical axis L direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens driving device that forms an image of a subject by driving a lens in the direction of an optical axis.

  In recent years, as camera-equipped mobile phones equipped with cameras have become popular, opportunities for photographing various subjects using the mobile phones have increased. For example, you can shoot a subject that is far away from the camera lens, such as a friend or landscape (normal shooting), or a subject that is close to the camera lens, such as a bus timetable or petals (close-up shooting) There is a case.

  In close-up photography (macro photography), the lens position of the camera needs to be slightly closer to the subject side than the lens position during normal photography. For this reason, this type of photographic lens system includes a drive mechanism that drives the lens to move in the direction of the optical axis, so that the lens can be moved in the direction of the optical axis by driving the drive mechanism by switching a switch. (For example, refer to Patent Document 1).

  In the lens driving device disclosed in Patent Document 1, a casing (barrel) in which a plurality of lens sets are incorporated is assembled to a sleeve, and a coil is wound around the outer periphery of the sleeve. Then, the coil receives the magnetic flux from the nearby magnet and moves the sleeve in the optical axis direction. At this time, the movement of the sleeve is stopped at the optimum position by the two springs. In this manner, the lens set in the sleeve can be moved by a desired amount in the optical axis direction. Regarding the structure of this lens driving device, a yoke made of a magnetic material is disposed on the outer periphery of the sleeve and the coil, and a holder is disposed on the bottom of the sleeve and the coil.

  Here, according to an industry design specification (SMIA95), there may be a case where a dent must be provided on the side surface of the lens driving device. More specifically, a hook is provided in a power supply socket to which the lens driving device is attached, and a recess for engaging the hook may be provided on the side surface of the yoke.

International Publication No. WO2007 / 026830 (FIG. 1)

  However, when the concave portion is formed on the side surface of the yoke, workability and productivity are deteriorated as compared with the case where the concave portion is not formed. Further, when the recessed portion is formed on the side surface of the yoke, the design space from the sleeve to the yoke becomes narrow, and as a result, there is a problem that the degree of freedom in design is lowered.

  The present invention has been made in view of the above points, and an object thereof is to provide a lens driving device that prevents deterioration of workability and productivity.

  In order to solve the above problems, the present invention provides the following.

  (1) A movable body that holds the lens and is movable in the optical axis direction, a support body that supports the movable body so as to be movable in the optical axis direction, a coil, and a magnet are provided, and the movable body is moved in the optical axis direction. A magnetic drive mechanism for driving, and a spring member that is disposed between the movable body and the support body and restricts movement of the movable body in the optical axis direction, and the support body includes the spring member. A holder for fixing, and a yoke covering at least a part of the outer periphery of the magnet, and a case body covering at least a part of the periphery of the spring member among the holders, and an end surface of the spring member in the optical axis direction A lens driving device comprising a bottom member that covers at least a part of the lens driving member.

  According to the present invention, the moving body, the support, the magnetic drive mechanism, and the spring member are provided, and the support is a lens driving device including a holder and a yoke, and the case covers at least a part of the holder around the spring member. Since the body is configured separately from the bottom member that covers at least a part of the end surface of the spring member in the optical axis direction, a positioning recess may be provided on the side surface of the case body instead of the side surface of the yoke. it can. In addition, since the case body is configured separately from the bottom member of the holder, it can be molded separately from the bottom member.

  Therefore, when the recess is provided on the side surface of the lens driving device, it is not necessary to provide the recess on the side surface of the yoke, so that the workability and productivity of the yoke can be improved. In addition, if a positioning recess is provided in a case body that is formed separately from the bottom member, the processability and productivity of the recess itself can be improved. Furthermore, when the side surface of the yoke is not provided with a dent, the design space from the moving body to the yoke is not narrowed, so that it is possible to prevent a reduction in design freedom.

  (2) The lens driving device, wherein the case body is formed of a resin material and includes a plurality of divided case bodies having a substantially L-shaped cross section orthogonal to the optical axis direction.

  According to this invention, since the case body mentioned above is formed with the resin material, the workability at the time of forming the dent for positioning can be improved further. Further, since the case body is composed of a plurality of divided case bodies having a substantially L-shaped cross section orthogonal to the optical axis direction, the amount of resin material used is reduced as compared with, for example, a rectangular frame shape case body. Can be contributed to cost reduction.

  (3) The lens driving device, wherein the case body or the bottom member is formed with a rotation restricting portion for restricting the rotation of the movable body.

  According to the present invention, the case body or the bottom member described above is provided with the rotation restricting portion that restricts the rotation of the moving body. Therefore, even if a slight impact is applied to the lens driving device, the moving body is Rotation in the direction can be prevented, and consequently performance degradation of the lens driving device can be prevented.

  (4) A lens driving device characterized in that a positioning recess for positioning with respect to a device on which the lens driving device is mounted is formed on the outer periphery of the case body.

  According to the present invention, since the positioning recess for positioning with respect to the device on which the lens driving device is mounted is formed on the outer periphery of the case body described above, the power feeding to which the lens driving device is attached Even when a hook or the like is provided on the socket or the like, the positioning can be more reliably performed by engaging the positioning recess with the hook.

  According to the lens driving device of the present invention, since it is not necessary to provide a positioning recess on the side surface of the yoke, the workability and productivity of the yoke can be improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[Machine configuration]
FIG. 1 is a perspective view showing an external configuration of a lens driving device 1 according to an embodiment of the present invention. FIG. 2 is an exploded perspective view showing a mechanical configuration of the lens driving device 1 according to the embodiment of the present invention.

  1 and 2, the lens driving device 1 includes a lens barrel 10, a yoke 11, a cover 12, a sleeve 13, a first leaf spring 14, a second leaf spring 15, and a magnetic member. It has a wire spring 16, a magnet 17, a coil 18, a bottom member 19, a case body 20, and a conduction member 21.

  The lens driving device 1 has both the A direction (front side) approaching the subject (imaging target) and the B direction (rear side) approaching the opposite side (image side) of the sleeve 13 along the direction of the optical axis L. (Refer to FIG. 1). Further, the sleeve 13 that holds the lens barrel 10 in which one or a plurality of lenses are incorporated is configured to be movable in the direction of the optical axis L together with the wire spring 16 and the like. Equivalent to. The yoke 11, the cover 12, the bottom member 19, and the like correspond to an example of a “support” that supports the sleeve 13 and the like so as to be movable in the optical axis direction. The sleeve 13 and the like are driven in the direction of the optical axis L by a “magnetic drive mechanism” including a coil 18 and a magnet 17. Further, the bottom member 19 and the case body 20 correspond to an example of a “holder” for fixing the second leaf spring 15, and constitute a holder 30 (FIG. 1) in the present embodiment. The second leaf spring 15 is disposed between the sleeve 13 and the bottom member 19 and has a function of restricting movement of the sleeve 13 in the direction of the optical axis L, and is electrically divided into two pieces. Spring piece 151 and spring piece 152 (see FIG. 2).

  The yoke 11 is made of a ferromagnetic plate such as a steel plate, for example, and has a rectangular tube shape. In addition, although a magnetic material is used here, it does not exclude the use of a non-magnetic material. Further, the yoke 11 is exposed on the side surface of the lens driving device 1 to form a side surface portion thereof, and covers the side surface of the moving body (including at least a part of the outer periphery of the magnet 17).

  The cover 12 is attached to the yoke 11 and covers the subject side as a support, and a circular incident window 121 is formed in the center for taking in reflected light from the subject into the lens. The bottom member 19 holds an image sensor (not shown) on the image side.

  Here, as for the cover 12, a part by aluminum casting is used. In general, the cover 12 is often manufactured by resin molding. However, as a characteristic required for the lens driving device 1, electromagnetic noise from the outside must be blocked (EMI countermeasure), for example, plating / metal vapor deposition on the cover 12, or metal parts (Cap) It is necessary to use. Therefore, in the present embodiment, a part by aluminum casting is used. Thereby, EMI countermeasures can be taken. In particular, the electromagnetic wave shielding characteristics of aluminum can eliminate the need for plating / evaporation processes for EMI countermeasures, thus contributing to simplification of the manufacturing process and reduction of the number of parts (reduction of manufacturing costs). Can do. Further, by using aluminum for the cover 12, a certain degree of rigidity can be ensured as compared with the cover 12 made of a conventional resin material, so that the cover 12 can be made thin, and the lens driving device 1 can be made compact. Can contribute.

  Further, the features of the cover 12 will be described in detail with reference to FIG. FIG. 3 is a diagram showing a state when the cover 12 is enlarged. 3A shows the surface of the cover 12 (the surface when viewed from the front side), and FIG. 3B shows the back surface of the cover 12 (the surface when viewed from the rear side).

  As shown in FIG. 3A, four recesses 12 a are formed on the surface of the cover 12. Further, a frame portion 12c is formed on the surface of the cover 12 around a flat plate portion 12b. The plate portion 12b is lowered by one step from the frame portion 12c (recessed on the rear side).

  Thereby, a cover glass (not shown) can be installed for the purpose of protecting the lens. That is, the plate portion 12b is lowered from the frame portion 12c by the thickness of the cover glass, and the recessed portion 12a is used when the cover glass is bonded and fixed.

  On the other hand, as shown in FIG. 3B, on the back surface of the cover 12, four step portions 12d are formed at a position one step lower than the above-described back surface of the plate portion 12b (a portion recessed in the front side). Yes. The lens driving device 1 has an autofocus function, and the sleeve 13 integrated with the lens moves back and forth, but the step 12d determines the position when the sleeve 13 is closest to the object. be able to. In addition, the convex part 13a provided in the front-end surface of the sleeve 13 will contact | abut to four step parts 12d.

  Further, four edge portions 12 e are formed on the back surface of the cover 12. Thereby, when attaching the cover 12 to the yoke 11, positioning in the height direction can be performed. Further, four cutout portions 12 f are formed on the back surface of the cover 12. As a result, when the first leaf spring 14 is fixed to the sleeve 13 with an adhesive, the adhesive can be applied using a tool such as a syringe (the tip of the tool is cut out). It can be inserted into the lens driving device 1 through the part 12f), and can contribute to the simplification of the manufacturing process.

  In addition, the edge part 12e and the notch part 12f which were mentioned above are comprised by the fine dimension, and manufacture may be a little difficult by press work. Therefore, in the present embodiment, the component accuracy is further improved by manufacturing by casting. Further, if inexpensive aluminum is used as the material of the cover 12, the manufacturing cost can be reduced. Also, since aluminum has good workability, precision processing such as casting becomes easy.

  In the present embodiment, as the material of the cover 12, aluminum having many merits is used as described above, but other materials may be used. In particular, a material having a noise countermeasure (nonmagnetic metal material) is preferable. As a result, electromagnetic noise from the outside can be blocked, as well as electromagnetic noise from the inside of the lens driving device 1 can be blocked, and thus adverse effects on other electronic components can be reduced.

  The coil 18 includes a first coil 181 and a second coil 182, which are arranged in two stages in the direction of the optical axis L, both of which are annular. Then, the sleeve 13 is wound around the outer peripheral surface of the sleeve 13 at a predetermined interval, and the moving body is driven in the optical axis direction. In addition, eight magnets 17 are arranged in two stages in the optical axis direction. The magnets 17 of each stage are arranged such that the front magnet 17 is against the first coil 181 and the rear magnet 17 is the first. The two coils 182 face each other on the outer peripheral side, and are fixed to four corners on the inner peripheral surface of the yoke 11.

  In the present embodiment, the magnet 17 is magnetized to poles whose inner surface and outer surface are different from each other. For example, the four magnets 17 arranged on the front side are magnetized with the N pole on the inner surface, the outer surface is magnetized with the S pole, and the four magnets 17 arranged on the rear side have an S inner surface. The pole is magnetized and the outer surface is magnetized to the N pole.

  Both the first plate spring 14 and the second plate spring 15 are formed of a thin metal plate and have the same thickness in the optical axis direction.

  Since the yoke 11 is larger than the dimension in the optical axis direction of the region where the first coil 181 and the second coil 182 are arranged, and the dimension in the optical axis direction of the magnet 17, the front magnet 17. Leakage flux from the magnetic path configured between the first coil 181 and the magnetic path configured between the rear magnet 17 and the second coil 182 can be reduced. As a result, the linearity between the amount of movement of the sleeve 13 and the current flowing through the first coil 181 and the second coil 182 can be improved.

  The lens driving device 1 includes an annular wire spring (magnetic member) 16. The wire spring 16 applies a biasing force in the optical axis direction to the sleeve 13 by a magnetic attractive force acting between the wire spring 16 and the magnet 17. For this reason, it is possible to prevent the moving body (sleeve 13 or the like) from being displaced by its own weight when the coil is not energized, and as a result, the moving body (sleeve 13 or the like) can be maintained in a desired posture.

  The sleeve 13 is formed with the direction of the optical axis L as the axial direction, and the first coil winding portion 131 around which the first coil 181 is wound and the second coil winding portion 132 around which the second coil 182 is wound ( Each of which has a concave shape), and a first guide part 133, a second guide part 134, and a third guide part 135 for guiding the coil 18 in a predetermined position or winding direction.

  In the present embodiment, the inner surfaces of the four magnets 17 arranged on the front side are magnetized to the N pole, and the inner surfaces of the four magnets 17 arranged on the rear side are magnetized to the S pole. The winding directions of the first coil 181 and the second coil 182 wound around the winding portion 131 and the second coil winding portion 132 are opposite to each other. Thereby, when electric current is supplied to the coil 18, the generated force (thrust) is set in the same direction.

  Specifically, the winding direction of the coil 18 is changed by the second coil guide portion 134 disposed between the first coil winding portion 131 and the second coil winding portion 132. That is, the coil 18 (second coil 182) wound around the second coil winding part 132 is converted to a reverse direction using the second coil guide part 134, and the coil 18 (first coil 1 coil 181) is wound around the first coil winding part 131 by a predetermined number of turns. Further, when starting to wind the coil 18, the coil winding start end portion of the coil 18 is wound around the pins 136c and 136d (see FIG. 4) so that the winding work can be smoothly performed by applying tension to the coil 18. Has been. Similarly, the coil winding end portion of the coil 18 is wound around the pins 136a and 136b (see FIG. 4).

  The conducting member 21 serves as a medium for supplying current from the external power source to the coil 18, and the second plate spring 15 electrically connected to the winding start end and winding end of the coil 18. The two spring pieces 151 and 152 are configured to come into contact with each other and are electrically connected.

  Here, in the lens driving device 1 according to the present embodiment, at least a part of the periphery of the second plate spring 15 is covered with the case body 20 and the end surface (rear side) of the second plate spring 15 in the optical axis direction. At least a part of the end surface is covered with the bottom member 19, and the bottom member 19 and the case body 20 are configured separately. Hereinafter, the bottom member 19 and the case body 20 will be described in detail with reference to FIGS.

  FIG. 4 is a diagram illustrating a state when the bottom member 19 and the case body 20 are removed from the lens driving device 1 and viewed from an oblique rear side. FIG. 5 is a diagram illustrating a state when the conductive member 21 is further removed from the lens driving device 1 illustrated in FIG. 4 and viewed from the rear side. FIG. 6 is a diagram showing a state when focusing on the second plate spring 15, the bottom member 19, and the case body 20. FIG. 7 is a diagram showing a state when attention is paid only to the case body 20 (divided case bodies 20a to 20d).

  4 to 7, the second leaf spring 15 includes two spring pieces 151 and 152 that are electrically separated. That is, the second leaf spring 15 includes spring pieces 151 and 152 that are electrically divided. As shown in FIG. 6, the spring pieces 151 (152) include two bottom member side mounting portions 151 a and 151 b (152 a and 152 b) held (fixed) on the resin-formed bottom member 19, and the sleeve 13. An arcuate mounting portion 151c (152c) attached to the lower end portion (rear end portion), and a plurality of sleeve side attachment portions 151d and 151e (152d and 152e) each having a substantially hole shape with a part cut away. The bottom member side attaching portions 151a and 151b (152a and 152b) and the sleeve side attaching portions 151d and 151e (152d and 152e) are provided with two spring portions 151f and 151g (152f and 152g). Moreover, in this Embodiment, as shown in FIG. 6, the two spring parts 151f and 151g (152f, 152g) are extended to the vicinity of the spring arrange | positioned at an adjacent corner | angular part. In addition, a pin penetrating portion 151h (151i) is formed in the arcuate placement portion 151c (152c), and a spring portion 151f (152g) is formed outside thereof.

  A plurality of protrusions 13 a to 13 d extending to the image sensor side are formed at the lower end (rear end) of the sleeve 13. Therefore, the sleeve side attachment portions 151d and 151e (152d and 152e) are configured to engage with the protrusions 13a to 13d.

  On the other hand, as shown in FIG. 6, the four bottom member side attachment portions 151 a and 151 b (152 a and 152 b) of the spring pieces 151 and 152 are held on the bottom member 19 surface. Projections 191 a to 191 d extending toward the subject are formed at the four corners of the bottom member 19. Therefore, the protrusions 191a to 191d are configured to engage with the holes formed in the bottom member side attachment portions 151a and 151b (152a and 152b). By these engagements, the spring pieces 151 and 152 are held by the bottom member 19.

  On the other hand, the sleeve-side attachment portions 151d and 151e (152d and 152e) and the protrusions 13a to 13d and the holes formed in the bottom member-side attachment portions 151a and 151b (152a and 152b) and the protrusions 191a to 191d These are fixed by welding or the like.

  Accordingly, the spring pieces 151 and 152 are difficult to rotate in the circumferential direction around the optical axis L, and the sleeve 13 is also difficult to rotate in the circumferential direction around the optical axis L. Thus, the protrusions 191 a to 191 d formed on the bottom member 19 correspond to an example of a rotation stopper that restricts the rotation of the sleeve 13.

  In the present embodiment, the rotation stopper is provided on the bottom member 19 side, but may be provided on the case body 20 side. That is, it is good also as providing the protrusion which engages with the hole formed in the bottom member side attaching part 151a, 151b (152a, 152b) corresponding to the protrusions 191a-191d in the case body 20. FIG. Thereby, the shape of the bottom member 19 is simplified (to the extent that the protrusions 191a to 191d are unnecessary), and the workability of the bottom member 19 can be improved.

  The rear end surface of the sleeve 13 is provided with six contact portions 137 that come into contact with the bottom member 19, and the contact portion 137 comes into contact with a predetermined portion of the bottom member 19, so that the sleeve 13 is in the optical axis. Positioned in the L direction.

  Near the center of the arcuate placement portion 151c (152c), pin penetration portions 151h and 151i that are cut out in a substantially circular shape are formed as described above. And the four pins 136 (136a-136d) mentioned above are comprised so that these pin penetration parts 151h and 151i may be penetrated (refer FIG. 4). These four pins 136 (136a to 136d) are not in contact with the bottom member 19. Further, the pin penetrating portions 151h and 151i are not in contact with other members such as the case body 20. The pins 136 (136a to 136d) are used when the coil 18 and the second leaf spring 15 are electrically connected to each other, but detailed description thereof is omitted.

  In FIG. 7, the case body 20 formed of a resin material is composed of four divided case bodies 20 a to 20 d whose cross section perpendicular to the direction of the optical axis L is approximately L-shaped. And the positioning recessed parts 20e-20h for positioning with respect to the apparatus in which the lens drive device 1 is mounted are formed in the outer periphery of the division | segmentation case bodies 20a-20d (in FIG. 7, positioning recessed part 20f and Only the positioning recess 20h is visible).

  In addition, although the case body 20 was comprised from the four division | segmentation case bodies 20a-20d, it is good also as comprising, for example, two U-shaped division | segmentation case bodies. In addition, the positioning recesses 20e to 20h are configured by connecting a plane parallel to the optical axis L and a plane inclined with respect to the optical axis L. For example, the plane parallel to the optical axis L is a bottom surface. However, the shape, size, and number are not limited. Depending on the device on which the lens driving device 1 is mounted, the optimum shape, size, and number can be obtained.

  Here, as shown in FIG. 6, in the lens driving device 1 according to the present embodiment, among the second leaf springs 15, the spring portions 151 f and 151 g near the bottom member side attachment portions 151 a and 151 b (152 a and 152 b). The periphery of (152f, 152g) is covered with the case body 20. Specifically, the bottom member side attachment portions 151a and 151b (152a and 152b) in the bottom member side attachment portions 151a and 151b (152a and 152b) and the spring portions 151f and 151g (152f and 152g) It is located inside the L-shaped split case bodies 20a to 20d. In addition, the rear end surface in the optical axis L direction of the spring portions 151 f and 151 g (152 f and 152 g) of the second plate spring 15 is covered with the bottom member 19. In other words, the second leaf spring 15 is placed on the surface of the bottom member 19. The bottom member 19 and the case body 20 are configured separately. Thereby, the positioning recesses 20 e to 20 h can be formed separately from the bottom member 19.

[Assembly method]
An outline of an assembling method of the lens driving device 1 will be described. FIG. 8 is a view showing a state where the second leaf spring 15 is not separated from the frame 50. In the handling of the leaf spring 15 before assembly, there is a possibility that the leaf spring 15 may be deformed by directly gripping, and in order to prevent the deformation, the assembly work is performed without separating the frame 50. . Further, when the frame 50 is not provided, when the four bottom member side mounting portions of the second leaf spring 15 are inserted into the protrusions 191a to 191d formed on the bottom member 19, the second leaf spring 15 itself Is small, each bottom member side mounting portion is inserted into the protrusion, resulting in poor assemblability. Therefore, the frame 50 is left without being separated so that the assembling work can be easily performed.

  First, the coil 18 is wound around the sleeve 13 and welded and UV bonded. Subsequently, the second plate spring 15 having the frame 50 is attached to the sleeve 13 by welding, UV bonding or the like. Finally, the coil 18 is soldered to the second leaf spring 15. This completes the sleeve assembly.

  Then, the sleeve assembly is attached to the bottom member 19 in which the conducting member 21 is fixed in advance by UV bonding or the like, and the frame 50 attached to the second leaf spring 15 is separated. Thereby, the bottom member assembly is completed.

  Thereafter, the case body 20 is attached to the bottom member assembly by bonding or the like. Finally, the yoke 11 and the cover 12 are UV bonded, and the cover 12 and the sleeve assembly are UV bonded. In this way, the lens driving device 1 can be assembled. It should be noted that soldering is appropriately performed at a place where electrical conduction is required.

  According to this assembling method, if the case body 20 and the bottom member 19 are integrally formed, the frame 50 becomes an obstacle and the second leaf spring 15 cannot be assembled to the bottom member 19 first. . However, according to this assembling method, the case body 20 and the bottom member 19 are separate from each other. Therefore, as described above, after the second leaf spring 15 is assembled to the bottom member 19 (having gaps at the four corners), The case body 20 can be adhered. Thereby, the assembly property of the 2nd leaf | plate spring 15 and the bottom member 19 can be improved.

  In addition to this method, there are other assembly methods. The other method different from the assembly method described above will be described. First, the coil 18 is wound around the sleeve 13 to be welded and UV-bonded. Subsequently, the second plate spring 15 with the frame 50 is attached by welding, UV bonding or the like to form a sleeve assembly. On the other hand, a conductive member 21 is attached to the bottom member 19 by UV bonding or the like to form a bottom member set. On the other hand, after the magnet 17 is UV bonded to the yoke 11, the case body 20 is attached by UV bonding to form a yoke assembly. Finally, the sleeve assembly is welded to the bottom member assembly, UV bonded, etc., and then the frame 50 of the second leaf spring 15 attached to the yoke assembly is cut off and attached to the sleeve assembly by UV bonding or the like. The cover 12 is also attached by UV bonding or the like. In this way, the lens driving device 1 can be assembled.

  In the above two assembling methods, four case bodies 20 may be connected to the yoke 11 at a time by connecting four case bodies 20 with a cross member.

[basic action]
In the lens driving device 1 according to the present embodiment, the moving body is normally located on the image sensor side (image side) (when the first coil 181 and the second coil 182 are not energized). At this time, the wire spring 16 regulates the displacement of the moving body by a magnetic attractive force acting between the wire 17 and the magnet 17. However, since the distance between the wire spring 16 and the magnet 17 is maintained to some extent, the magnetic attractive force between the wire spring 16 and the magnet 17 does not become too strong. As a result, it is possible to prevent the center axis of the moving body from being shifted, and thus to prevent the tilt characteristics from deteriorating.

  In such a state, when a current is passed through the first coil 181 and the second coil 182, the first coil 181 and the second coil 182 receive an upward (front) electromagnetic force, respectively ( Fleming's left hand rule). As a result, the first coil 181, the second coil 182, and the sleeve 13 begin to move toward the subject side (front side).

  At this time, an elastic force that restricts the movement of the sleeve 13 is generated between the first leaf spring 14 and the front end of the sleeve 13 and between the second leaf spring 15 and the rear end of the sleeve 13. . For this reason, when the electromagnetic force that moves the sleeve 13 forward and the elastic force that restricts the movement of the sleeve 13 are balanced, the sleeve 13 stops. In addition, when a reverse current is passed through the first coil 181 and the second coil 182, the first coil 181 and the second coil 182 receive a downward (rear) electromagnetic force, respectively. .

  At that time, by adjusting the amount of current flowing through the first coil 181 and the second coil 182 and the elastic force acting on the sleeve 13 by the first leaf spring 14 and the second leaf spring 15, the sleeve 13 (moving) Body) can be stopped at a desired position. In addition, by stopping the sleeve 13 using the balance between the electromagnetic force and the elastic force, unlike the case where the members are brought into contact with each other so as to be locked with the locking portion or the like, it is possible to prevent occurrence of a collision sound. .

[Main effects of the embodiment]
As described above, according to the lens driving device 1 according to the present embodiment, when the positioning recess is provided on the side surface, it is not necessary to provide the recess on the side surface of the yoke 11 (see FIG. 1). 11 workability and productivity can be improved.

  Further, if positioning recesses 20e to 20h are provided on the outer periphery of the case body 20 configured separately from the bottom member 19, the workability and productivity of these recesses themselves can be improved, and as a result, the cost can be reduced. Can be connected.

  In addition, if the side surface of the yoke 11 is not provided with a dent, the design space from the sleeve 13 to the yoke 11 is not narrowed (the shape and size of the design space from the sleeve 13 to the yoke 11 is not affected by magnetic flux). This may affect the magnetic path that passes therethrough), and can prevent a reduction in the degree of freedom in design.

  Moreover, since the case body 20 is a resin component and is disposed on the side surface of the second leaf spring 15 to which power is supplied, the insulation can be improved. Further, since the bottom member 19 and the case body 20 are separate parts, the assemblability of the second leaf spring 15 and the bottom member 19 disposed inside the case body 20 can be improved.

  The lens driving device 1 can be attached to various electronic devices other than the camera-equipped mobile phone. For example, PHS, PDA, bar code reader, thin digital camera, surveillance camera, vehicle rear view confirmation camera, door with optical authentication function, and the like.

  The lens driving device according to the present invention is useful as a device capable of improving workability and productivity.

It is a perspective view which shows the external appearance structure of the lens drive device which concerns on embodiment of this invention. It is a disassembled perspective view which shows the machine structure of the lens drive device which concerns on embodiment of this invention. It is a figure which shows a mode when a cover is expanded. It is a figure which shows a mode when a bottom member and a case body are removed from a lens drive device, and it sees from the diagonal rear side. It is a figure which shows a mode when a conduction | electrical_connection member is further removed from the lens drive device shown in FIG. 4, and it sees from the back side. It is a figure which shows a mode when paying attention to a 2nd leaf | plate spring, a bottom member, and a case body. It is a figure which shows a mode when paying attention only to a case body (divided case body). It is a figure which shows the state in which the 2nd leaf | plate spring is not cut away from the flame | frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens drive device 11 Yoke 12 Cover 13 Moving body (sleeve)
14 First leaf spring 15 Second leaf spring 16 Wire spring 17 Magnet 18 Coil 19 Bottom member 20 Case body 20a to 20d Split case body 21 Conducting member

Claims (4)

A movable body that holds the lens and is movable in the optical axis direction;
A support that supports the movable body so as to be movable in the optical axis direction;
A magnetic drive mechanism comprising a coil and a magnet, and driving the movable body in the optical axis direction;
A spring member that is disposed between the movable body and the support body and restricts movement of the movable body in the optical axis direction;
The support includes a holder that fixes the spring member, and a yoke that covers at least a part of the outer periphery of the magnet.
A lens drive characterized in that a case body that covers at least a part of the periphery of the spring member of the holder is configured separately from a bottom member that covers at least a part of an end surface of the spring member in the optical axis direction. apparatus.   The lens driving device according to claim 1, wherein the case body is formed of a resin material and includes a plurality of divided case bodies having a substantially L-shaped cross section orthogonal to the optical axis direction.   The lens driving device according to claim 1, wherein the case body or the bottom member is formed with a rotation restricting portion that restricts rotation of the movable body.   4. The lens driving device according to claim 1, wherein a positioning recess for positioning with respect to a device on which the lens driving device is mounted is formed on an outer periphery of the case body. 5. .

Images