JP6723629B2 - Lens driving device and camera module using the lens driving device - Google Patents

Description

The present invention has a lens holding member on which a lens body can be mounted, and a leaf spring that movably supports the lens holding member in the optical axis direction of the lens body, and a lens provided with a damping material on the leaf spring. The present invention relates to a driving device and a camera module using the lens driving device.

Patent Document 1 describes an invention relating to a lens driving device.
In this lens driving device, a yoke is fixed on a base member, and a lens holder (lens holding member) having a lens barrel mounted therein and a spacer are provided inside the yoke. An upper leaf spring and a lower leaf spring are provided between the lens holder and the base member or the spacer, and the lens holder is movably supported in the optical axis direction.

A drive coil is provided around the lens holder, and a drive magnet that faces the drive coil faces the inside of the yoke. The lens holder is driven in the optical axis direction by the drive current applied to the yoke and the magnetic field of the drive magnet.

The lower leaf spring connects the lower inner peripheral end attached to the lens holder, the lower outer peripheral end attached to the base member, and the lower inner peripheral end to the lower outer peripheral end. It has a lower arm part that A U-turn shaped portion is provided on the lower arm portion, and an elastic adhesive is provided so as to straddle the U-turn shaped portions at positions facing each other. The elastic adhesive is made of a stretchable and flexible resin such as a silicone-based adhesive. In Patent Document 1, by providing the elastic adhesive, it is possible to suppress the secondary resonance of the lower arm portion. It is stated that

JP, 2016-4108, A

The lens driving device described in Patent Document 1 has the following problems.
(1) In the lower arm portion of the lower leaf spring, the elastic adhesive is attached between the arm portions facing each other in the U-turn shape portion. The elastic adhesive will be hardened after being applied after it is in liquid form, but due to the wettability of the applied elastic adhesive, the direction in which the arms extend between the opposing arms until it cures. Easy to spread. As a result, the application location of the elastic adhesive cannot be determined, and the vibration damping effect varies from product to product.

(2) When the lens holder supported by the lower leaf spring is driven in the optical axis direction, the two arm portions facing each other in the U-turn shape portion of the lower arm portion are opposite to each other in the optical axis direction. Attempts to bend and deform in the direction (intersection direction). Therefore, a large tensile stress is always applied to the elastic adhesive provided between the two arm portions, and the elastic adhesive is easily peeled off from the arm portion of the lower leaf spring.

The present invention solves the above-mentioned conventional problems, and provides a lens driving device that can stably provide a damping material and can reduce variations in damping effect, and a camera module using the lens driving device. The purpose is to do.

The present invention relates to a lens holding member on which a lens body can be mounted, and a leaf spring which is provided between the lens holding member and a fixed portion and movably supports the lens holding member in the optical axis direction of the lens body. A lens driving device having a driving unit that moves the lens holding member in the optical axis direction,
The leaf spring has a fixed-side support portion fixed to the fixed portion, a movable-side support portion fixed to the lens holding member, and an elastic deformation that connects the fixed-side support portion and the movable-side support portion. Possible connecting parts are integrally formed,
The connecting portion has at least one bending portion and elastic arm portions connected to both ends of the bending portion,
An elastically deformable opposing arm portion having a free end as an opposing portion is integrally formed with the leaf spring so that the bent portion and the opposed portion face each other and a control is provided between the bent portion and the opposed portion. A swing material is provided,
The opposed arm portion extends from the opposed portion toward at least one of the fixed side support portion and the movable side support portion, and the elastic arm portion and the opposed arm portion that are connected to both ends of the bent portion, respectively, It is characterized in that they extend in directions away from each other with the damping material interposed therebetween .

In the lens driving device of the present invention, at least one of the bent portion and the facing portion is provided with at least two protruding portions that project into a facing gap located between the bent portion and the facing portion. It is preferable that at least a part of the damping material is formed between the two protrusions.

Alternatively, at least one of the bent portion and the facing portion is formed with at least two protruding portions spaced apart from each other and projecting into the facing gap located between the bent portion and the facing portion. At least a part of the material is located between the two protruding portions, and the facing portion has a portion corresponding to a position between the two protruding portions connected to the facing arm portion. preferable.

In the lens driving device of the present invention, the bending portion is provided at two or more places in the connecting portion, and the damping material is provided between at least one of the bending portion and the facing portion. Can be configured as

For example, the bending portion is provided at two places in the connecting portion, the first elastic arm portion is provided between the movable side support portion and the first bending portion, and the first bending portion and the second bending portion are provided. A second elastic arm portion is provided between the bent portion and the third elastic arm portion between the second bent portion and the fixed side support portion,
The damping material is provided between the facing portion and the first bent portion provided on the fixed-side support portion.

Alternatively, the bending portion is provided at two places in the connecting portion, the first elastic arm portion is provided between the movable side support portion and the first bending portion, and the first bending portion and the second bending portion are provided. A second elastic arm portion is provided between the bent portion and the third elastic arm portion between the second bent portion and the fixed side support portion,
The damping material is provided between the facing portion and the second bent portion provided on the movable side support portion.

Alternatively, the bending portion is provided at two places in the connecting portion, and a first elastic arm portion is provided between the movable side support portion and the first bending portion, and the first bending portion and the second bending portion are provided. A second elastic arm portion is provided between the bent portion and the third elastic arm portion between the second bent portion and the fixed side support portion,
The damping material is provided between the facing portion and the first bending portion provided on the fixed side support portion, and the damping material is provided between the facing portion and the second bending portion provided on the movable side support portion. Further, the vibration damping material is provided.

In the lens driving device of the present invention, the bent portion has an inner edge portion and an outer edge portion opposite to the inner edge portion, and the facing portion faces the outer edge portion.

Further, it is preferable that the outer edge portion of the bent portion is substantially circular, and the diameter of the outer edge portion is larger than the minimum value of the width dimension between the outer edges of the two elastic arm portions extending from the bent portion.

Next, a camera module of the present invention includes any one of the lens driving devices, a lens body held by the lens holding member of the lens driving device, and an image sensor facing the lens body. It is a feature.

According to the present invention, a bent portion is provided in the connecting portion of the leaf spring, and a damping material is provided between the bent portion and the facing portion provided on at least one of the fixed side supporting portion and the movable side supporting portion. There is. Therefore, it becomes possible to appropriately provide the damping material in the target portion in the target amount, and the target vibration damping effect can be expected, and the variation in the vibration damping effect for each product becomes small.

Further, when the lens holding member moves in the optical axis direction, the damping material is in contact with the bent portion that is located between the two elastic arm portions that bend in the plate thickness direction and is less likely to bend than the elastic arm portions. Even if the elastic arm portion is deformed, it is difficult to apply excessive tensile stress to the damping material, and it is easy to suppress the problem of the damping material coming off.

A perspective view showing the appearance of a lens driving device according to an embodiment of the present invention. An exploded perspective view showing a state where a cover member is removed from the lens driving device shown in FIG. An exploded perspective view showing a state in which a yoke is further removed from the lens driving device shown in FIG. An exploded perspective view showing each member housed inside the yoke, A partially enlarged perspective view showing an enlarged view of a portion V in FIG. Sectional drawing which cut|disconnected the lens drive device in the state covered with the yoke and the cover member by the VI-VI line of FIG. A partially enlarged plan view showing an enlarged connecting portion of the upper leaf spring, The 1st Embodiment is shown and it is explanatory drawing which shows the damping effect when a damping material is provided in a 1st bending part, The 2nd Embodiment is shown and explanatory drawing which shows the damping effect when a damping material is provided in a 2nd bending part, The elements on larger scale which show the connection part of the upper leaf spring of a 1st modification on an enlarged scale. The partial expanded top view which expands and shows the connection part of the upper leaf spring of a 2nd modification, 11A and 11B are partially enlarged plan views showing further modifications of the second modification shown in FIG. The partial expanded top view which expands and shows the connection part of the upper leaf spring of a 3rd modification, The partial expanded top view which expands and shows the connection part of the upper leaf spring of the 4th modification.

1 to 3 show the entire structure of a lens driving device 1 according to an embodiment of the present invention.
The lens driving device 1 has a lens holding member 10. A lens body (lens barrel) is attached to the center hole 11 of the lens holding member 10. The lens body includes one lens or a lens group in which a plurality of lenses are combined, and a lens or a lens holder that holds the lens group. A female screw portion 11a is formed in the central hole 11, and a male screw portion is formed on the outer peripheral surface of the range holder. The male screw portion is screwed into the female screw portion 11a, so that the lens body is mounted on the lens holding member 10. It will be installed. The lens body may be fixed to the lens holding member 10 with an adhesive.

The Z1-Z2 direction shown in each drawing is a vertical direction, and is a direction parallel to the optical axis O of the lens body. The lens driving device 1 is mounted on a portable electronic device such as a mobile phone. An image sensor such as a CCD is arranged on the Z2 side of the lens driving device 1. A camera module is configured by the lens driving device 1, the lens body, and the image sensor. In the camera module, the lens holding member 10 and the lens body mounted on the lens holding member 10 move in the Z1-Z2 directions to automatically focus an image formed on the image sensor.

As shown in FIGS. 1 to 3, a support base 2 is provided in the lens driving device 1, and a yoke 3 is fixed on the support base 2. Further, a cover member 4 is combined with the outside of the yoke 3, and the cover member 4 is fixed to the yoke 3 with an adhesive. The yoke 3 is made of a magnetic metal plate such as a rolled steel plate. Both the support base 2 and the cover member 4 are made of a non-magnetic material. The support base 2 is formed of a synthetic resin material, and the cover member 4 is formed of a metal plate such as a non-magnetic stainless steel plate, but it may be formed of a synthetic resin material.

The support base 2, the yoke 3 and the cover member 4 are combined to form a fixed portion (housing) having a storage space inside. As shown in FIG. 4, the light transmission hole 2b is opened in the support base 2, and as shown in FIG. 3, the light transmission hole 3b is opened in the ceiling portion 3a of the yoke 3, and as shown in FIG. A light transmitting hole 4b is formed in the ceiling portion 4a of the cover member 4. The support base 2, the yoke 3, and the cover member 4 have a quadrangular outer planar shape.

As shown in FIG. 4, spring fixing portions 2 a having protrusions are formed on the four corners of the support base 2. On the support base 2, a pair of lower leaf springs 20 which are separated from each other are attached. In each of the lower leaf springs 20, a fixed side support portion 21, a movable side support portion 22 inside thereof, and a connecting portion 23 connecting the fixed side support portion 21 and the movable side support portion 22 are made of conductive leaf spring metal. It is integrally formed of material.

The fixed side support portion 21 of each lower leaf spring 20 is formed with mounting holes 21a at two locations on the X1 side and the X2 side. The respective mounting holes 21a are fitted to the protrusions provided on the spring fixing portion 2a of the support base 2, and the protrusions are heat caulked to fix the support base 2 and the fixed-side support portion 21. ..

Mounting holes 22a are formed at three locations in the movable side support portion 22 of each lower leaf spring 20. As shown in part in FIG. 6, projections that serve as spring fixing portions 12 are provided at six positions on the lower surface 10 a of the lens holding member 10. By fitting the respective mounting holes 22a formed in the movable side support portion 22 of the lower leaf spring 20 into the protrusions of the spring fixing portion 12 and caulking the protrusions, the movable side support portion 22 is moved to the lens holding member 10. Is fixed to the lower surface 10a of the.

The connecting portion 23 provided on each lower leaf spring 20 is composed of a meander-shaped (meandering) arm having two bent portions and is elastically deformable.

As shown in FIG. 3, an upper leaf spring 30 is provided on the lens holding member 10 (Z1 side). As shown in FIG. 4, the upper leaf spring 30 has a rectangular frame-shaped fixed side support portion 31, a movable side support portion 32 inside thereof, and a connection that connects the fixed side support portion 31 and the movable side support portion 32. The part 33 and the part 33 are integrally formed of a leaf spring metal material. The connecting portion 33 is composed of meander-shaped (meandering) arms and is elastically deformable.

As shown in FIGS. 3 and 4, the lens driving device 1 is provided with four driving magnets M. Each drive magnet M is fixed to the inner surface of the side wall portion 3c of the yoke 3 with an adhesive. Mounting portions 31a are formed at four corners of the fixed side support portion 31 of the upper leaf spring 30, and each mounting portion 31a is provided between the lower surface of the ceiling portion 3a of the yoke 3 and the drive magnet M. It is fixed by being sandwiched between. In addition, a part of the adhesive for fixing the drive magnet M is also present on the upper surface and the lower surface of the mounting portion 31a.

As shown in FIG. 4, on the upper surface 10b of the lens holding member 10 facing the Z1 side, spring fixing portions 13 are provided on the Y1 side and the Y2 side. The movable side support portion 32 of the upper leaf spring 30 is fixed to the spring fixing portion 13 by means of an adhesive or the like.

FIG. 7 shows the connecting portion 33 of the upper leaf spring 30 in an enlarged manner. The connecting portion 33 is provided with a bent portion formed in a U-shape at least at one place, and in the connecting portion 33 of the embodiment, the first bent portion located inside (on the side close to the optical axis O). Two bent portions, that is, the portion 34 and the second bent portion 35 located on the outer side, are provided. The first elastic arm portion 36 a is provided between the movable side support portion 32 and one end portion of the first bent portion 34. The second elastic arm portion 36b is provided between the other end of the first bent portion 34 and the one end of the second bent portion 35. The third elastic arm portion 36c is provided between the other end of the second bent portion 35 and the mounting portion 31a formed on the fixed-side support portion 31.

That is, one end portion of the first elastic arm portion 36 a is connected to the movable side support portion 32, and the other end portion of the first elastic arm portion 36 a is connected to one end portion of the first bent portion 34. Further, one end of the third elastic arm portion 36c is connected to the other end portion of the second bent portion 35, and the other end portion of the third elastic arm portion 36c is connected to the fixed side support portion 31 (mounting portion 31a). It is connected.

The elastic arm portion in the present specification is a beam-shaped arm portion that is larger in the longitudinal direction than the lateral width dimension, that is, has a length dimension in the extending direction in which the elastic arm portion extends, and is bendable and deformable to the plate thickness side in the longitudinal direction. Means The width dimension may be uniform or changed in the vertical direction, and a wide relay portion or the like may be provided midway in the vertical direction. The bent portion means a structure in which the directions of the two elastic arms connected to both ends of the bent portion are changed, and the bent portion itself may or may not be elastically deformed. The bent portion can also be called a folded portion.

As shown in FIG. 7, the first bent portion 34 has an inner edge portion 34a and an outer edge portion 34b. The inner edge portion 34a is a concave edge portion, the outer edge portion 34b is a convex edge portion, and the two elastic arm portions 36a and 36b extend from the inner edge portion 34a side. The second bent portion 35 also has an inner edge portion 35a and an outer edge portion 35b.

In the upper leaf spring 30, an elastically deformable opposing arm portion 37 extends from the fixed-side support portion 31, and an opposing portion 37 a that faces the first bending portion 34 is integrally formed at the tip of the opposing arm portion 37. Has been done. The definition of the opposing arm portion 37 here is the same as that of the elastic arm portion, and it can be flexibly deformed to the plate thickness side in the longitudinal direction (extending direction). The facing portion 37a is formed with facing extending portions 37b, 37b extending to both sides around a connecting portion with the facing arm portion 37 as a center. A facing gap 45 is formed between the outer edge portion 34b of the first bent portion 34 and the facing portion 37a (including the facing extension portions 37b, 37b). The outer edge portion 34b of the first bent portion 34 is formed with a pair of protrusions 34c, 34c which are spaced from each other and protrude toward the facing gap 45 (on the side of the facing portion 37a). A portion of the facing portion 37a corresponding to (facing) the position (intermediate position) between the pair of protrusions 34c, 34c is connected (connected) to the facing arm portion 37.

In the upper leaf spring 30, the elastically deformable opposed arm portion 38 extends from the movable side support portion 32, and the opposed portion 38 a that faces the second bent portion 35 is integrally formed at the tip of the opposed arm portion 38. Has been done. In the structure of FIG. 7, the opposing arm portion 38 integrally projects from the base portion of the first elastic arm portion 36a, but in this case also, the opposing arm portion 38 is defined as extending from the movable side support portion 32. It The opposed arm portion 37 described above extends from the fixed-side support portion 31, but the opposed arm portion 37 may also extend from the third elastic arm portion 36c. In this case as well, the opposed arm portion 37 is fixed. It is defined as extending from the side support portion 31.

The facing portion 38a is formed with facing extending portions 38b, 38b extending to both sides centering on a connecting portion with the facing arm portion 38. A facing gap 46 is formed between the outer edge portion 35b of the second bent portion 35 and the facing portion 38a (including the facing extension portions 38b, 38b). The outer edge portion 35b of the second bent portion 35 is formed with a pair of protrusions 35c, 35c spaced apart from each other and protruding toward the facing gap 46 (opposing portion 38a side). The facing portion 38a is connected (connected) to the facing arm portion 38 at a portion corresponding to (facing) the position (intermediate position) between the pair of protrusions 35c, 35c.

The damping material 61 can be provided in the facing gap 45 between the outer edge portion 34b of the first bent portion 34 and the facing portion 37a, and the facing gap 46 between the outer edge portion 35b of the second bent portion 35 and the facing portion 38a can be provided. It is possible to provide the damping material 62 on the. The damping materials 61 and 62 may be provided by selecting one of the facing gaps 45 and 46, or by providing both of them. The damping effect of the damping materials 61 and 62 will be described later.

The lens holding member 10 includes a lower leaf spring 20 fixed to the support base 2 under the drive magnet M, and an upper leaf spring 30 fixed on the lower surface of the ceiling portion 3a of the yoke 3 above the drive magnet M. It is sandwiched and housed in an operating space surrounded by four drive magnets M. The connecting portion 23 provided on the lower leaf spring 20 has two bent portions and a thin elastic arm portion, and the connecting portion 33 provided on the upper leaf spring 30 also has two bent portions 34 and 35 and is thin. It has elastic arm portions 36a, 36b, 36c. The lens holding member 10 is movably supported in the Z1-Z2 directions by elastic deformation of elastic arms of the upper and lower connecting portions 23 and 33.

As shown in FIGS. 3 and 4, the lens holding member 10 is provided with the coil C around which the covered conductor wire is wound. The four driving magnets M fixed inside the yoke 3 face the outside of the coil C at four corners of the lens holding member 10. The four driving magnets M are magnetized to have the same magnetic poles on the facing surfaces facing the coil C. The coil C and the four driving magnets M constitute a driving unit that moves the lens holding member 10 in the optical axis O direction.

A metal plate is embedded in the support base 2 shown in FIG. 4, and a part of the metal plate serves as a plurality of connection terminals 5 and projects downward from the side of the support base 2. Of the four spring fixing portions 2a of the support base 2, two spring fixing portions 2a provided on the X1 side are provided with exposed portions 5a where a part of the metal plate is exposed. The fixed side support portion 21 of each lower leaf spring 20 is formed with a joint portion 21b having a penetrating portion on the X1 side, and each joint portion 21b (around the penetrating portion) individually adheres to the exposed portion 5a. Then, they are joined by solder, a conductive adhesive, or welding. As a result, one of the plurality of connection terminals 5 is electrically connected to the one lower leaf spring 20, and the other one of the plurality of connection terminals 5 is electrically connected to the other lower leaf spring 20.

On the lower surface 10a of the lens holding member 10, two projecting portions (not shown) projecting downward (Z2 direction) are integrally formed. Both ends of the coated wire forming the coil C are drawn out to the lower surface 10a side of the lens holding member 10, the insulating coating is removed, and the coated wire is wound around the protrusion. The movable side support portion 22 of each of the lower leaf springs 20 divided into two and the end portion of the covered conductor wire wound around the protrusion are joined by a conductive adhesive. Therefore, a drive current can be applied to the coil C from the two connection terminals 5 via the two lower leaf springs 20.

As shown in FIGS. 5 and 6, a position detector 50 is provided on the side of the lens driving device 1 on the X1 side. The position detection unit 50 is composed of one position detection magnet 51 and one magnetic detection member 52. The position detection magnet 51 is magnetized to have different magnetic poles on a lower surface 51a facing the Z2 direction and an upper surface 51b facing the Z1 direction. For example, the lower surface 51a is the N pole and the upper surface 51b is the S pole.

As shown in FIGS. 4 and 5, a holding recess 15 is formed on the side of the lens holding member 10 on the X1 side, and the position detecting magnet 51 is fixed in the holding recess 15 with an adhesive. There is. As shown in FIG. 6, the position detection magnet 51 is fixed to the lower side of the coil C wound around the lens holding member 10 so as to be in close contact with the lower side of the coil C.

As shown in FIG. 4, the movable side supporting portion 22 of the lower leaf spring 20 located on the Y1 side of the two lower leaf springs 20 has a magnet supporting portion 25 extending from the location where the mounting hole 22a is formed on the X1 side. Are formed. As shown in FIGS. 5 and 6, the magnet support portion 25 faces the lower surface 51 a of the position detection magnet 51. In FIG. 6, the magnet support portion 25 faces the lower surface 51a with a slight gap, but the magnet support portion 25 may be in contact with the lower surface 51a of the position detection magnet 51. When the magnet support portion 25 faces the lower surface 51a of the position detection magnet 51, it is possible to prevent the position detection magnet 51 from falling out of the lens holding member 10 even if an external impact is applied. ..

As shown in FIGS. 4, 5, and 6, the magnetic detection member 52 is installed on the side of the support base 2 on the X1 side. The magnetic detection member 52 contains a magnetic detection element such as a Hall element or a magnetoresistive effect element and a circuit associated therewith. As shown in FIGS. 4 and 6, a holding recess 6 is formed in the support base 2, and the holding recess 6 has an exposed portion 5b on the surface thereof, from which any of the plurality of connection terminals 5 is exposed. .. The magnetic detection member 52 is positioned inside the holding recess 6, and the electrode portion 52a (see FIGS. 4 and 5) on the lower surface of the magnetic detection member 52 is connected to the exposed portion 5b via a conductive adhesive or the like. .. As shown in FIG. 6, the magnetic detection member 52 is located below the lower surface 51 a of the position detection magnet 51 and faces the lower surface 51 a with the magnet support portion 25 interposed therebetween.

As shown in FIGS. 2 and 3, the yoke 3 has a cylindrical side wall portion 3c that covers the lens holding member 10 and the coil C so as to surround the coil C from four side surfaces, and the light transmission holes 3b at the four corner portions. The opposing yoke portion 3d bent downward (Z2 direction) from the ceiling portion 3a near the inner edge portion is integrally provided. The side wall portion 3c of the yoke 3 contacts the outside of the drive magnet M, the opposing yoke portion 3d is inserted between the lens holding member 10 and the coil C, and is located between the side wall portion 3c and the opposing yoke portion 3d. The drive magnet M and the coil C are interposed.

As shown in FIGS. 2 and 5, an opening 3e is formed on the surface of the side wall 3c of the yoke 3 facing the X1 side. The opening 3e is formed in a size that exposes the position detection magnet 51 by opening in a portion facing the position detection magnet 51. The opening 3e is a recess (notch) that is open to the lower edge of the side wall 3c. However, the opening 3e may be a circular or oval hole. As shown in FIGS. 1 and 6, the opening 3e is laterally covered with a cover member 4 made of a non-magnetic material. Therefore, it is possible to prevent dust and the like from entering the inside through the opening 3e.

As shown in FIG. 6, in the position detection unit 50, the position detection magnet 51 held by the lens holding member 10 and the magnetic detection member 52 held by the support base 2 are along the optical axis O. They are opposed to each other at intervals in the vertical direction (Z1-Z2 direction). Since the position detection unit 50 can be arranged in the X1-X2 direction without requiring a large space, it is possible to suppress an increase in the width dimension of the lens driving device 1 in the X1-X2 direction and to realize miniaturization.

As shown in FIG. 6, the opening 3e formed in the side wall 3c of the yoke 3 is covered with the cover member 4 from the outside. The inside of the opening 3e corresponds to the plate thickness dimension t of the yoke 3. It is a reserve space of width. Therefore, the position detection magnet 51 can be inserted into the opening 3e by the width W. In this structure, the width dimension of the position detection magnet 51 in the X1-X2 direction can be increased, the magnetic flux given to the magnetic detection member 52 can be increased, the detection sensitivity of the position detection magnet 51 by the magnetic detection member 52 can be increased, and the position detection magnet 51 can be increased. Can be detected reliably when the Z moves in the Z1-Z2 direction.

Further, since the position detecting magnet 51 moves in the Z1-Z2 direction inside the opening 3e, it is possible to prevent the moving position detecting magnet 51 from interfering with the yoke 3.

Next, the operation of the lens driving device 1 will be described.
A magnetic flux generated from the drive magnet M is induced inside the yoke 3, and a magnetic field that crosses the coil C is formed between the opposing yoke portion 3d of the yoke 3 and the drive magnet M. When a drive current is applied to the coil C via the two connection terminals 5 and the two lower leaf springs 20, the lens holding member 10 is in the optical axis direction by the electromagnetic force of the drive current and the magnetic field intersecting the drive current. It is driven in the Z1-Z2 direction, and an image is focused on an image sensor such as a CCD provided on the Z2 side in the camera module.

In the position detection unit 50 shown in FIG. 6, the position of the position detection magnet 51 that moves together with the lens holding member 10 in the Z1-Z2 direction, that is, the position of the lens holding member 10 is detected by the magnetic detection member 52. By giving this detection output to the control unit of the electronic circuit unit attached to the camera module, the drive current given to the coil C for moving the lens holding member 10 to the target position in the Z1-Z2 direction can be controlled with high accuracy. become.

As shown in FIGS. 2 and 5, since the opening 3e is formed in the side wall portion 3c of the yoke 3 at a portion facing the position detection magnet 51, the magnetic flux from the position detection magnet 51 is transferred to the side wall portion 3c of the yoke 3. The magnetic field from the position detection magnet 51 can be detected with high accuracy by the magnetic detection member 52.

Next, the elastic deformation of the connecting portion 33 of the upper leaf spring 30 and the damper effect of the damping material will be described.

FIG. 8 shows the first embodiment of the present invention. In the first embodiment, the damping material 61 is provided in the facing gap 45 between the outer edge portion 34b of the first bent portion 34 and the facing portion 37a (including the facing extension portions 37b, 37b). In the first embodiment, since the damping material is not provided in the facing gap 46 on the second bent portion 35 side, the facing arm portion 38 and the facing portion 38a may be omitted.

The damping material 61 is an epoxy resin, a silicone resin, or an acrylic resin, and a material that becomes an elastic body or a viscoelastic body in a cured state is used. The damping material 61 is formed by supplying a liquid resin material to the facing gap 45 so as to connect the first bent portion 34 (outer edge portion 34b) and the facing portion 37a, and curing the resin material by heat curing or UV curing. .. The liquid resin material that has not yet been cured and serves as the damping material 61 is supplied into the facing gap 45 while being in contact with the outer edge portion 34b of the first bent portion 34 and the facing portion 37a, but the facing gap 45 is limited. Since the liquid resin material is formed within the defined range, the liquid resin material is suppressed from flowing toward the inner edge portion 34a of the first bent portion 34, and the first elastic arm portion 36a and the second elastic arm portion are formed as in the conventional case. It is also possible to prevent the resin material from migrating to the portion 36b.

As shown in FIG. 7, the outer edge portion 34b of the first bent portion 34 is substantially circular, and its diameter R is the minimum value of the width dimension Wd between the outer edges of the first elastic arm portion 36a and the second elastic arm portion 36b. Is set larger than. Therefore, the total distance of the portion of the outer edge portion 34b of the first bent portion 34 that faces the facing portion 37a can be increased, and it is sufficient to hold the damping material 61 between the outer edge portion 34b and the facing portion 37a. It is possible to form the facing gap 45 having a large width. Further, two protrusions 34c, 34c are formed on the outer edge portion 34b of the first bent portion 34 with a space therebetween, and the protrusions 34c, 34c respectively face the facing extension portions 37b, 37b. Therefore, the liquid resin supplied to the facing gap 45 stays between the protrusions 34c, 34c and is less likely to flow out to the side. Therefore, by hardening the resin, the damping material 61 is made uniform in the facing gap 45. It can be attached in various ranges.

When the drive current is applied to the coil C, the lens holding member 10 moves in the Z1 direction and the Z2 direction which are the directions of the optical axis O. As shown in FIG. 8, at this time, the movable side support portion 32 of the upper leaf spring 30 moves together with the lens holding member 10 in the F1 direction and the F2 direction along the optical axis direction. Since the outer edge portion 34b of the first bent portion 34 receives a restraining force by the damping material 61 provided between the outer edge portion 34b and the facing portion 37a, in the connecting portion 33, the first elastic arm portion 36a is mainly connected to the first bent portion. With the 34 side serving as a fulcrum, the leaf spring bends in the α1-α2 direction, which is the plate thickness direction, to exert an elastic force.

Since the vibration damping material 61 is also elastically deformable, the damper effect (vibration damping effect) is exhibited by the elastic force and the viscous force of the vibration damping material 61. Further, following the slight vertical movement of the first bending portion 34, the opposing arm portion 37 is also elastically deformed in the α3-α4 direction, which is the plate thickness direction, and both the elastic force of the damping material 61 and the opposing arm portion 37. The damper effect can be demonstrated with. Since the first elastic arm portion 36a is long in the vertical direction (extending direction), the spring constant is low, while the opposing arm portion 37 has a short vertical dimension and a high spring constant. Therefore, the resonance frequencies of the first elastic arm portion 36a and the opposing arm portion 37 are significantly different. Therefore, when primary resonance or secondary resonance is about to occur in the first elastic arm portion 36a due to the movement of the lens holding member 10 in the Z1-Z2 direction, the presence of the opposing arm portion 37 having a resonance frequency different from that. Thereby, the amplitude of the primary resonance and the secondary resonance can be suppressed. Further, the elasticity or viscoelasticity of the damping material 61 damps the vibration, and the resonance can be effectively suppressed.

Further, the connecting portion between the facing arm portion 37 and the facing portion 37a corresponds to an intermediate position between the two protruding portions 34c, 34c provided on the first bending portion 34, and is located in the middle of the facing portion 37a, Opposite extending portions 37b, 37b are formed on both sides of the connecting portion. Therefore, the vibration at the free end of the opposing arm portion 37 acts on substantially the center of the damping material 61, and the damping effect of the damping material 61 can be exhibited in a well-balanced manner. Further, it is possible to prevent the vibration damping material 61 from peeling or falling off because it is suppressed that the excessive stress that tries to peel the vibration damping material 61 from the first bent portion 34 and the facing portion 37a acts. Therefore, the damping material 61 can be stably held at a predetermined position.

FIG. 9 shows a second embodiment of the present invention. In the second embodiment, the damping material 62 is provided in the facing gap 46 between the outer edge portion 35b of the second bent portion 35 and the facing portion 38a (including the facing extension portions 38b, 38b). In the second embodiment, since the damping material is not provided in the facing gap 45 on the side of the first bent portion 34, the facing arm portion 37 and the facing portion 37a may be omitted.

In the second embodiment shown in FIG. 9, the opposing gap 46 between the second bent portion 35 and the opposing portion 38a receives the restraining force by the damping material 62, so that the movable side supporting portion 32 together with the lens holding member 10 has F1. When it moves in the −F2 direction, the bending of the base portion of the first elastic arm portion 36a on the movable support portion 32 side in the β1-β2 direction is restrained (suppressed), and the second elastic arm portion 36b and the third elastic arm portion. The bending of the 36c in the β3-β4 direction is also restrained (suppressed). Accordingly, the bending of the first elastic arm portion 36a in the Z1-Z2 direction is also suppressed, and the vibration of the entire connecting portion 33 is suppressed. Thereby, the primary resonance and the secondary resonance of the connecting portion 33 are suppressed.

As shown in FIG. 8, a first embodiment in which a damping material 61 is provided on the first bending portion 34 side, and as shown in FIG. 9, a damping material 62 is provided on the second bending portion 35 side. In the second embodiment, the frequencies of the first resonance and the second resonance that can be suppressed are different. Therefore, either the damping material 61 or the damping material 62 may be selected according to the difference in the size and mass of the mounted lens body and the difference in the magnitude of the driving current applied to the coil C. Further, in the present invention, both the damping material 61 on the first bent portion 34 side and the damping material 62 on the second bent portion 35 side may be provided.

A modified example of the structure of the connecting portion 33 of the upper leaf spring 30 is shown below FIG. In the following modified examples, parts having the same functions as those shown in FIGS. 7 to 9 will be described with the same reference numerals even if the shapes are different.

In the connecting portion 33A of the first modified example shown in FIG. 10, three protrusions 34c are formed on the outer edge portion 34b of the first bending portion 34, and three protrusions 34c are formed on the outer edge portion 35b of the second bending portion 35. The protrusion 35c is formed. By forming three or more protrusions 34c on the first bent portion 34, the adhesion strength of the damping material 61 arranged in the facing gap 45 can be increased. Similarly, by forming three or more protrusions 35c on the outer edge portion 35b of the second bent portion 35, it is possible to increase the adhesive strength of the damping material 62 arranged in the facing gap 46.

11 and 12A and 12B show the connecting portion 33B of the second modified example.
In the connecting portion 33B shown in FIG. 11, the protruding portion 34d is formed on the outer edge portion 34b of the first bent portion 34. An opposing arm portion 37 extends from the fixed-side support portion 31, and a tip portion thereof is an opposing portion 37c. The damping material 61 is arranged in the facing gap 47 between the extension portion 34d and the facing portion 37c.

In the modification shown in FIG. 12A, an elastic arm-shaped facing portion 37 d bent in one direction from the tip of the facing arm portion 37 extending from the fixed-side support portion 31 is provided, and the outer edge of the first bent portion 34 is provided. A damping material 61 is arranged in the facing gap 45 between the portion 34b and the facing portion 37d. In the modified example shown in FIG. 12B, the tip of the opposing arm portion 37 extending from the fixed-side support portion 31 is the opposing portion 37e. The facing portion 37e has a shape surrounding the outer edge portion 34b of the first bent portion 34, and has a width between the outer edge portion 34b of the first bent portion 34 and the facing portion 37e along the arc of the outer edge portion 34b. A substantially uniform facing gap 45 is formed. A damping material 61 is provided in the facing gap 45.

In the connecting portion 33B of the second modification shown in FIGS. 11 and 12A and 12B, the facing portions 37c, 37d, and 37e of the facing arm portion 37 are elongated elastic arm shapes capable of elastically deforming themselves. Is. Therefore, when the first bent portion 34 is about to be flexibly deformed in the Z1-Z2 direction, the opposing portions 37c, 37d, 37e can be elastically deformed along with the elastic deformation of the damping material 61, and the opposing portions 37c, 37d, 37e can also be deformed. The vibration damping effect can be exhibited. Further, since the facing portions 37c, 37d, and 37e easily move together with the damping material 61, the damping material 61 is less likely to peel off.

In the connecting portion 33C of the third modification shown in FIG. 13, the facing arm portion 37 is not formed on the fixed-side support portion 31, but the facing portion 39a is directly formed on the fixed-side support portion 31, The damping material 61 is disposed in the facing gap 48 between the outer edge portion 34b of the first bent portion 34 and the facing portion 39a. In the connecting portion 33C, the facing portion 39a has higher rigidity in the plate thickness direction than the facing portion 37a shown in FIG. Therefore, when the movable side support portion 32 moves in the Z1-Z2 direction, the restraining force on the first bent portion 34 becomes slightly stronger, and the primary resonance and the secondary resonance can be limited.

It has shown the connection part 33D of the 4th modification shown in FIG. A facing portion 39b is formed on the fixed side support portion 31 of the lower leaf spring 30. The damping material 62 is provided in the facing gap 49 between the outer edge portion 35b of the second bent portion 35 and the facing portion 39b. In this modified example, the deformed portion from the first elastic arm portion 36a to the second elastic arm portion 36b via the first bent portion 34 is not constrained by the damping material 62, so that the elastic coefficient of the connecting portion 33D. Can be set low.

In the above-described embodiment, the first bent portion 34 is provided with the protrusions 34c and 34c projecting into the facing gap 45, but the facing portion 37a may be provided with the protrusion protruding into the facing gap 45. Good. Furthermore, protrusions may be provided on both the first bent portion 34 and the facing portion 37a. The same applies to the second bent portion 35 side.

Further, in the above-described embodiment, the case where two bent portions are formed in the connecting portion 33 has been described, but the number of bent portions may be one, or may be three or more.

1 Lens Driving Device 2 Support Base 3 Yoke 3c Side Wall 3e Opening 4 Cover Member 5 Connection Terminal 10 Lens Holding Member 10a Lower Surface of Lens Holding Member 20 Lower Leaf Spring 21 Fixed Side Support 22 Movable Side Support 23 Connection 25 Magnet support portion 30 Upper leaf spring 31 Fixed side support portion 32 Movable side support portion 33 Connecting portion 34 First bent portion 35 Second bent portion 34a, 35a Inner edge portion 34b, 35b Outer edge portion 34c, 35c Projection portion 36a First elastic arm Part 36b Second elastic arm part 36c Third elastic arm part 37, 38 Opposing arm parts 37a, 38a Opposing parts 45, 46 Opposing gap 50 Position detecting part 51 Position detecting magnet 52 Magnetic detecting members 61, 62 Damping material C Coil M Drive magnet O optical axis

Claims (11)

A lens holding member on which a lens body can be mounted, a leaf spring which is provided between the lens holding member and a fixed portion and movably supports the lens holding member in the optical axis direction of the lens body, and the lens holding member. A lens driving device having a driving unit that moves a member in the optical axis direction,
The leaf spring includes a fixed-side support portion fixed to the fixed portion, a movable-side support portion fixed to the lens holding member, and an elastic deformation that connects the fixed-side support portion and the movable-side support portion. Possible connecting parts are integrally formed,
The connecting portion has at least one bending portion and elastic arm portions connected to both ends of the bending portion,
An elastically deformable opposing arm portion having a free end as an opposing portion is integrally formed with the leaf spring so that the bent portion and the opposed portion face each other and a control is provided between the bent portion and the opposed portion. A swing material is provided,
The opposed arm portion extends from the opposed portion toward at least one of the fixed side support portion and the movable side support portion, and the elastic arm portion and the opposed arm portion that are connected to both ends of the bent portion, respectively, A lens drive device, wherein the lens drive device extends in a direction in which the vibration control members are separated from each other . The lens driving device according to claim 1, wherein a width dimension of the facing arm portion is smaller than a width dimension of the facing portion. At least one of the bent portion and the facing portion is formed with at least two protruding portions spaced apart from each other and projecting into a facing gap located between the bent portion and the facing portion. The lens driving device according to claim 1, wherein at least a part of the material is located between the two protrusions. At least two projecting portions projecting into a facing gap located between the bent portion and the facing portion are formed at least one of the bent portion and the facing portion with a space therebetween. is located between at least a portion of two of said projections, said opposed portion, a portion corresponding to a position between the two said projections, the claims are connected to opposite arms 1 or 2. The lens driving device according to 2 . 5. The connecting portion is provided with the bent portions at two or more places, and the damping material is provided between at least one of the bent portions and the facing portion. The lens driving device according to claim 1. The bending portion is provided at two places in the connecting portion, the first elastic arm portion is provided between the movable side support portion and the first bending portion, and the first bending portion and the second bending portion are provided. A second elastic arm portion is provided between the second elastic portion and the fixed side support portion, and a third elastic arm portion is provided between the second bent portion and the fixed side support portion.
The lens driving device according to claim 5, wherein the damping material is provided between the first bending portion and the facing portion provided on the facing arm portion extending toward the fixed-side support portion. The bending portion is provided at two places in the connecting portion, the first elastic arm portion is provided between the movable side support portion and the first bending portion, and the first bending portion and the second bending portion are provided. A second elastic arm portion is provided between the second elastic portion and the fixed side support portion, and a third elastic arm portion is provided between the second bent portion and the fixed side support portion.
The lens driving device according to claim 5, wherein the vibration damping material is provided between the facing portion and the second bending portion provided on the facing arm portion extending toward the movable side support portion. The bending portion is provided at two places in the connecting portion, the first elastic arm portion is provided between the movable side support portion and the first bending portion, and the first bending portion and the second bending portion are provided. A second elastic arm portion is provided between the second elastic portion and the fixed side support portion, and a third elastic arm portion is provided between the second bent portion and the fixed side support portion.
The damping member is provided between the facing portion provided on the facing arm portion extending toward the fixed side support portion and the first bent portion, and the facing arm extending toward the movable side support portion. between the opposing portion and the second bent portion provided on the parts, the lens driving device according to claim 5, wherein said damping material is provided. The lens driving device according to claim 1, wherein the bent portion has an inner edge portion and an outer edge portion opposite to the inner edge portion, and the facing portion faces the outer edge portion. .. The lens drive according to claim 9, wherein the bent portion has a substantially circular outer edge portion, and a diameter of the outer edge portion is larger than a minimum value of a width dimension between outer edges of the two elastic arms extending from the bent portion. apparatus. 11. A lens drive device according to claim 1, a lens body held by the lens holding member of the lens drive device, and an image pickup element facing the lens body. Camera module to be used.

Images