JP5564353B2 - Lens drive device - Google Patents

Description

  The present invention relates to a lens driving device mounted on a relatively small camera used in a mobile phone or the like.

  Conventionally, as a lens driving device for driving a photographing lens of a camera mounted on a mobile phone or the like, a holder that holds the lens and moves in the optical axis direction, and the holder in the optical axis direction via two leaf springs. A lens driving device is known that includes a fixing member that is movably held, a driving coil that drives the holder in the optical axis direction, and a driving magnet (for example, see Patent Document 1). In the lens driving device described in Patent Document 1, the leaf springs are disposed on both ends of the holder in the optical axis direction. Moreover, the leaf | plate spring is provided with the inner peripheral part fixed to a holder, the outer peripheral part fixed to a fixing member, and the connection part which connects an inner peripheral part and an outer peripheral part.

  In the lens driving device described in Patent Document 1, a buffer member made of an elastic resin or the like is provided in the vicinity of the connection portion between the holder and the leaf spring and in the vicinity of the connection portion between the fixing member and the leaf spring. Yes. Therefore, in this lens driving device, it is possible to prevent the lens from shaking (rolling) in the direction orthogonal to the optical axis direction.

JP 2006-251111 A

  In a lens driving device in which a holder is held by a fixed member via a leaf spring as in the lens driving device described in Patent Document 1, vibration is transmitted from the outside when the lens is moved in the optical axis direction or to the holder. The lens tends to vibrate in the optical axis direction together with the holder. In order to appropriately control the position of the lens in the optical axis direction, it is preferable that the vibration of the lens in the optical axis direction is converged as soon as possible. However, in the lens driving device described in Patent Document 1, it is possible to prevent the lens from rolling in the direction orthogonal to the optical axis direction, but the vibration in the optical axis direction of the lens is converged in a short time. I can't.

  Therefore, an object of the present invention is to provide a lens driving device capable of converging the vibration of the lens in the optical axis direction in a short time.

In order to solve the above problems, a lens driving device of the present invention includes a movable body that holds a lens and is movable in the optical axis direction of the lens, a fixed body that holds the movable body so as to be movable in the optical axis direction, and a movable body. A driving mechanism for driving the body in the optical axis direction, a spring member connecting the movable body and the fixed body, and a viscosity that shortens the vibration time of the movable body by absorbing vibration in the optical axis direction of the movable body relative to the fixed body. The spring member includes an elastic cushioning material, and the spring member includes a movable side fixed portion fixed to the movable body, a fixed side fixed portion fixed to the fixed body, and an arm connecting the movable side fixed portion and the fixed side fixed portion. The movable side fixed portion is disposed on the inner peripheral side of the fixed side fixed portion, and has one end of the arm portion connected to the movable side fixed portion as the tip of the arm portion, and the arm portion connected to the fixed side fixed portion. If the other end is the base end of the arm, the cushioning material spans the movable side fixed part and the base end of the arm. Provided, the installation location of the buffer material, characterized in that the projections and / or recesses which is a measure of the range of setting the buffer member is formed.

  The lens driving device of the present invention includes a buffer material having viscoelasticity that absorbs vibration in the optical axis direction of the movable body relative to the fixed body and shortens the vibration time of the movable body. Therefore, in the present invention, the vibration in the optical axis direction of the lens held by the movable body can be converged in a short time by the action of the buffer material. Further, in the present invention, a convex portion and / or a concave portion, which serves as a measure of the buffer material installation range, is formed at the buffer material installation location. Therefore, it is possible to install a cushioning material in the intended amount with the convex portion and / or the concave portion as a guide. Therefore, in the present invention, it is possible to set the convergence time of vibration in the optical axis direction of the lens as intended.

  Here, when a buffer material that absorbs vibration in the optical axis direction of the movable body with respect to the fixed body is provided, the movable body easily moves in one of the optical axis directions due to the influence of the buffer material, but the other in the optical axis direction. May be difficult to move. That is, when the cushioning material is provided, the amount of movement of the movable body from the predetermined reference position depends on the direction of movement of the movable body, even though the current value supplied to the drive coil constituting the drive mechanism is the same. There is a risk of significant fluctuations. In other words, if a buffer material is provided, the area surrounded by the hysteresis curve indicating the relationship between the current value supplied to the drive coil and the amount of movement of the movable body from the predetermined reference position may increase, and the movable area It may be difficult to control the amount of body movement.

  In the lens driving device of the present invention, the convex portion and / or the concave portion, which serve as an indication of the installation range of the cushioning material, is formed at the location where the cushioning material is installed. It is possible to appropriately set the amount of the cushioning material. Therefore, in the present invention, by appropriately setting the amount of the buffer material to be installed, it is possible to shorten the convergence time of vibration in the optical axis direction of the lens while reducing the area of the region surrounded by the hysteresis curve. It becomes possible. Further, in the present invention, the balance between the size of the area surrounded by the hysteresis curve and the convergence time of the vibration in the optical axis direction of the lens is controlled by appropriately setting the amount of the buffer material to be installed. It becomes possible.

Moreover, in this invention , the shock absorbing material is provided in the location straddling the movable side fixed part and the base end side of an arm part . In other words, the cushioning material is provided at a location straddling the base end side of the arm portion close to the fixed side fixing portion fixed to the fixed body and the movable side fixing portion fixed to the movable body . Therefore , it is possible to effectively absorb vibration in the optical axis direction of the movable body relative to the fixed body by the buffer material.

  In the present invention, the movable side fixed portion is formed in a substantially annular shape or a substantially arc shape, the arm portion is formed in a substantially arc shape, and the convex portion and / or the concave portion are formed on the outer periphery or the arm portion of the movable side fixed portion. It is preferably formed on one of the inner circumferences. If comprised in this way, it will become possible to prescribe | regulate the installation range of a shock absorbing material with a sufficient precision by a convex part and / or a recessed part. That is, for example, one convex portion is formed on the outer periphery of the movable side fixed portion, one convex portion is formed on the inner periphery of the arm portion, and the interval between the convex portions is an indication of the installation range of the cushioning material. In such a case, the interval between the convex portions is likely to vary due to variations in the relative position between the movable side fixed portion and the arm portion. For example, two convex portions are arranged at a predetermined interval on the outer periphery of the movable side fixed portion. When it is formed by, it becomes possible to suppress the dispersion | variation in the space | interval between convex parts. Therefore, it is possible to accurately define the installation range of the cushioning material by the convex portion and / or the concave portion.

  In the present invention, it is preferable that at a location where the cushioning material is installed, at least two convex portions are formed on the movable side fixed portion or the arm portion with a predetermined interval. If comprised in this way, even if it is a case where the width | variety of a movable side fixed part and the width | variety of an arm part are narrow, it becomes possible to ensure the rigidity of a movable side fixed part or an arm part. That is, when the width of the movable side fixed part or the width of the arm part is narrow, if the concave part is formed in the movable side fixed part or the arm part, the width of the part where the concave part is formed becomes further narrow, so the movable side fixed part The rigidity of the part and the arm part tends to decrease. On the other hand, when the convex part is formed on the movable side fixed part or the arm part, even if the width of the movable side fixed part or the width of the arm part is narrow, the width of the part where the convex part is formed is Since it becomes wide, it becomes possible to ensure the rigidity of a movable side fixed part or an arm part.

  In the present invention, for example, at the location where the cushioning material is installed, two convex portions or two concave portions are formed on the movable side fixed portion or the arm portion with a predetermined interval therebetween, and between the two convex portions. Alternatively, a cushioning material is provided between the two recesses. In this case, it is possible to set the standard of the installation range of the cushioning material with a simple configuration using two convex portions or two concave portions.

  In the present invention, for example, the spring member includes four arms formed in a substantially arc shape with a central angle of approximately 90 °.

  In the present invention, it is preferable that the buffer material is provided at a plurality of locations at substantially equal angular intervals in the circumferential direction centered on the optical axis of the lens. If comprised in this way, it will become possible to absorb the vibration in the optical-axis direction of the movable body with respect to a fixed body without a bias | bias by the buffer material in the circumferential direction.

  In the present invention, the buffer material is, for example, a silicon-based viscoelastic composition. In this case, since the buffer material can be provided by coating, the buffer material can be provided even in the final stage of the assembly process of the lens driving device. In this case, it is possible to ensure the adhesion of the buffer material to the member to which the buffer material is applied.

  As described above, in the lens driving device of the present invention, it is possible to converge the vibration of the lens in the optical axis direction in a short time.

It is a perspective view of the lens drive device concerning an embodiment of the invention. It is sectional drawing of the EE cross section of FIG. It is a disassembled perspective view of the lens drive device shown in FIG. It is a top view of the leaf | plate spring shown in FIG. It is an enlarged view of the F section of FIG. It is a figure for demonstrating the installation location of the buffer material concerning embodiment of this invention, (A) is a top view of a lens drive device, (B) is arrangement | positioning of a leaf | plate spring, a cover member, a spacer, and a buffer material It is a top view which shows a relationship. It is a figure for demonstrating the damping characteristic of the vibration in the lens drive device shown in FIG. It is a figure for demonstrating the installation location of the shock absorbing material concerning other embodiment of this invention. It is a figure for demonstrating the installation location of the shock absorbing material concerning other embodiment of this invention. It is an enlarged view which shows the structure of the convex part concerning other embodiment of this invention. It is an enlarged view which shows the structure of the recessed part concerning other embodiment of this invention. It is an enlarged view which shows the structure of the convex part and recessed part concerning other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Schematic configuration of lens driving device)
FIG. 1 is a perspective view of a lens driving device 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line EE of FIG. FIG. 3 is an exploded perspective view of the lens driving device 1 shown in FIG. In the following description, as shown in FIG. 1 and the like, the three directions orthogonal to each other are defined as an X direction, a Y direction, and a Z direction. The X direction is the left-right direction, the Y direction is the front-rear direction, and the Z direction is the up-down direction. The Z1 direction side is the “upper” side, and the Z2 direction side is the “lower” side.

  The lens driving device 1 of this embodiment is mounted on a relatively small camera used in a mobile phone, a drive recorder, a surveillance camera system, or the like, and is formed in a substantially quadrangular prism shape as a whole as shown in FIG. Has been. Specifically, the lens driving device 1 is formed so that the shape of the lens for photographing when viewed from the direction of the optical axis L (optical axis direction) is a substantially square shape. The four side surfaces of the lens driving device 1 are substantially parallel to the left-right direction or the front-rear direction.

  In this embodiment, the Z direction (vertical direction) is substantially coincident with the optical axis direction. In addition, in a camera equipped with the lens driving device 1 of the present embodiment, an imaging element (not shown) is arranged on the lower side, and a subject arranged on the upper side is photographed. That is, in this embodiment, the upper side (Z1 direction side) is the subject side (object side), and the lower side (Z2 direction side) is the anti-subject side (imaging element side, image side).

  As shown in FIGS. 1 and 2, the lens driving device 1 includes a movable body 2 that holds a photographing lens and is movable in the optical axis direction, and a fixed body that holds the movable body 2 so as to be movable in the optical axis direction. 3 and a drive mechanism 4 for driving the movable body 2 in the optical axis direction. Further, as shown in FIGS. 2 and 3, the lens driving device 1 includes leaf springs 5 and 6 as spring members that connect the movable body 2 and the fixed body 3. That is, the movable body 2 is movably held by the fixed body 3 via the leaf springs 5 and 6. In this embodiment, one leaf spring 5 is disposed on the upper end side of the movable body 2, and two leaf springs 6 are disposed on the lower end side of the movable body 2.

  The movable body 2 includes a sleeve 8 that holds a lens holder 7 to which a plurality of lenses are fixed. The fixed body 3 includes a cover member 10 constituting a side surface of the lens driving device 1, a base member 11 constituting an end surface of the lens driving device 1 on the side opposite to the subject, and a spacer 12 to which a part of the leaf spring 5 is fixed. It has.

  The lens holder 7 is formed in a substantially cylindrical shape. A plurality of lenses are fixed on the inner peripheral side of the lens holder 7.

  The sleeve 8 is formed of, for example, a resin material and has a substantially cylindrical shape. The sleeve 8 holds the lens holder 7 on its inner peripheral side. That is, the outer peripheral surface of the lens holder 7 is fixed to the inner peripheral surface of the sleeve 8. At the lower end of the sleeve 8, a contact surface 8a (see FIG. 2) that contacts a later-described reference surface 11b formed on the base member 11 is formed so as to be substantially orthogonal to the optical axis direction. A winding recess 8b around which a driving coil 14 described later is wound is formed on the outer peripheral side of the sleeve 8 (see FIG. 2). The winding recess 8 b is formed so as to be recessed from the outer peripheral surface of the sleeve 8. Moreover, the winding recessed part 8b is formed in two places in the state which left the predetermined space | interval in the up-down direction.

  The cover member 10 is made of a magnetic material. Moreover, the cover member 10 is formed in the substantially square cylinder shape with the bottom which has the bottom part 10a and the cylinder part 10b. A through hole 10c is formed in the center of the bottom portion 10a disposed on the upper side so as to penetrate the bottom portion 10a in the vertical direction. Moreover, the opening part 10d is formed in each of the four corners of the bottom part 10a so that it may connect with the through-hole 10c. The opening 10d is formed so as to penetrate the bottom 10a in the vertical direction. Further, the opening 10d is formed, for example, so that the shape when viewed from the up-down direction is a substantially semicircular shape.

  The base member 11 is formed of an insulating resin material. The base member 11 is formed in a block shape having a substantially square shape when viewed from the optical axis direction. The base member 11 is attached to the lower end side of the cover member 10. A through hole 11 a is formed at the center of the base member 11. Further, a reference surface 11b for determining the reference position of the movable body 2 in the optical axis direction is formed on the upper surface of the base member 11 so as to be substantially orthogonal to the optical axis direction (see FIG. 2).

  The spacer 12 is formed of, for example, a resin material and is formed in a substantially square flat block shape. The spacer 12 is formed in a frame shape, and a through-hole 12a that penetrates the spacer 12 in the vertical direction is formed at the center thereof. Openings 12b are formed at the four corners of the spacer 12 so as to be connected to the through holes 12a. The opening 12b is formed so as to penetrate the spacer 12 in the vertical direction. Moreover, the opening part 12b is formed so that the shape when it sees from an up-down direction may become a substantially semicircle shape, for example. The spacer 12 is fixed to the lower surface of the bottom 10 a of the cover member 10. In a state where the spacer 12 is fixed to the bottom portion 10a, the opening portion 10d and the opening portion 12b overlap in the vertical direction.

  The leaf spring 5 is fixed to the sleeve 8 and the spacer 12 so that the thickness direction and the vertical direction substantially coincide with each other. The detailed configuration of the leaf spring 5 will be described later.

  The leaf spring 6 has two movable side fixed portions fixed to the lower end side of the sleeve 8, two fixed side fixed portions fixed to the base member 11, and two connecting the movable side fixed portion and the fixed side fixed portion. Arm. The movable side fixed portion and the arm portion are formed in a substantially arc shape. The fixed-side fixing portions are formed in a substantially triangular shape, and are arranged at each of the four corners of the lens driving device 1. The leaf spring 6 is fixed to the sleeve 8 and the base member 11 so that the thickness direction and the vertical direction substantially coincide with each other. Further, when the movable body 2 is disposed at the reference position where the contact surface 8a of the sleeve 8 and the reference surface 11b of the base member 11 are in contact with each other, the urging force of the leaf spring 6 is movable by the leaf spring 6. 2 is fixed to the sleeve 8 and the base member 11 so as not to occur.

  The drive mechanism 4 includes two drive coils 14 wound around the outer periphery of the sleeve 8 and four drive magnets 15 disposed along each of the four side surfaces of the lens drive device 1. ing.

  The two driving coils 14 are wound around the winding recess 8b of the sleeve 8 with a predetermined interval in the vertical direction. For example, the two drive coils 14 are formed by sequentially winding one conductive wire. The two driving coils 14 are wound so that the direction of the current supplied to one driving coil 14 and the direction of the current supplied to the other driving coil 14 are different. Yes.

  The drive magnet 15 is formed in a substantially rectangular plate shape. Each of the four drive magnets 15 is fixed to the inner side surface of the cylindrical portion 10 b of the cover member 10 so as to face the outer peripheral surface of the drive coil 14. The cover member 10 of this embodiment fulfills the function of a yoke for forming a magnetic circuit.

  The drive magnet 15 is constituted by one magnet piece, for example. The driving magnet 15 is magnetized so that two different magnetic poles overlapping in the vertical direction are formed on the surface facing the driving coil 14. That is, in the driving magnet 15, the first magnet portion 15a and the second magnet portion 15b having different magnetic poles on the surface facing the driving coil 14 are integrated (see FIG. 2), and the first magnet portion 15a. And the second magnet portion 15b are arranged so as to overlap in the vertical direction. For example, the surface of the first magnet portion 15a facing the drive coil 14 is magnetized to the S pole, and the surface of the second magnet portion 15b facing the drive coil 14 is magnetized to the N pole.

  In the lens driving device 1 configured as described above, since the movable body 2 is held by the fixed body 3 via the leaf springs 5 and 6, when the movable body 2 is moved by the power of the drive mechanism 4, When vibration from the outside is transmitted to the movable body 2, the movable body 2 is likely to vibrate in the optical axis direction with respect to the fixed body 3. Therefore, the lens driving device 1 of the present embodiment is provided with a buffer material 17 (see FIG. 4 and the like) that absorbs vibration in the optical axis direction of the movable body 2 with respect to the fixed body 3 to shorten the vibration time of the movable body 2. ing. Hereinafter, detailed configurations of the buffer material 17 and the leaf spring 5 will be described.

(Configuration of leaf spring and cushioning material)
FIG. 4 is a plan view of the leaf spring 5 shown in FIG. FIG. 5 is an enlarged view of a portion F in FIG. FIGS. 6A and 6B are views for explaining an installation location of the buffer material 17 according to the embodiment of the present invention. FIG. 6A is a plan view of the lens driving device 1, and FIG. 6B is a leaf spring 5 and a cover member 10. FIG. 6 is a plan view showing a positional relationship between the spacer 12 and the buffer material 17.

  As shown in FIG. 4, the leaf spring 5 includes a movable side fixed portion 5a fixed to the upper end side of the sleeve 8, four fixed side fixed portions 5b fixed to the spacer 12, and a movable side fixed portion 5a. Four arm portions 5c that connect the fixed side fixing portion 5b are provided. The movable side fixing portion 5a is formed in a substantially annular shape with the optical axis L as the center. The fixed-side fixing portions 5 b are formed in a substantially triangular shape and are disposed at each of the four corners of the lens driving device 1. The arm part 5c is formed in a substantially arc shape. Specifically, the arm portion 5c is formed in a substantially arc shape with a central angle about the optical axis L being approximately 90 °. In the leaf spring 5, the movable body 2 is arranged at a reference position where the contact surface 8 a of the sleeve 8 and the reference surface 11 b of the base member 11 are in contact when no current is supplied to the drive coil 14. As shown, the sleeve 8 and the spacer 12 are fixed in a bent state.

  The movable side fixing portion 5a is disposed on the inner side (that is, the inner peripheral side) in the radial direction than the fixed side fixing portion 5b. The arm portion 5c is disposed between the movable side fixed portion 5a and the fixed side fixed portion 5b in the radial direction. The arm portions 5c are arranged at a substantially 90 ° pitch in the circumferential direction. Therefore, as shown in FIG. 4, the connecting portion 5d between one arm portion 5c and the movable side fixing portion 5a and the connecting portion 5e between the other one arm portion 5c and the fixed side fixing portion 5b are close to each other. doing. In the following description, one end of the arm portion 5c connected to the movable side fixing portion 5a is referred to as a distal end of the arm portion 5c, and the other end of the arm portion 5c connected to the fixed side fixing portion 5b is referred to as a base end of the arm portion 5c.

  On the outer periphery of the movable side fixed portion 5a, a plurality of convex portions 5f projecting outward in the radial direction are formed. Specifically, a pair of convex portions is provided on each of the outer circumferences of the movable side fixed portion 5a in the vicinity of the connecting portion 5d and on the inner peripheral side of the proximal end side of the arm portion 5c. 5f (that is, two convex portions 5f) are formed in a state in which a predetermined interval is provided in the circumferential direction. Further, the pair of convex portions 5f are formed at four locations at substantially equal angular intervals in the circumferential direction with the optical axis L as the center. That is, the pair of convex portions 5f are formed at a substantially 90 ° pitch with the optical axis L as the center. The convex portion 5f is formed in, for example, a semicircular shape, a semi-elliptical shape, or a polygonal shape such as a triangular shape.

  As shown in FIG. 6, the distal end side and the proximal end side of the arm portion 5 c and the peripheral portions of the connecting portion 5 d and the convex portion 5 f of the movable side fixing portion 5 a are viewed from the optical axis direction when the cover member 10. 10d and the opening 12b of the spacer 12 overlap. For this reason, when the lens driving device 1 is viewed from above, the distal end side and the proximal end side of the arm portion 5c and the peripheral portions of the connecting portion 5d and the convex portion 5f of the movable side fixing portion 5a are visible. .

  The buffer material 17 is a viscoelastic composition having viscoelasticity. For example, the buffer material 17 is a silicon-based gel. The buffer material 17 is provided at a location straddling the movable side fixed portion 5a and the arm portion 5c of the leaf spring 5. Specifically, the cushioning material 17 is provided at a location straddling each of the proximal end sides of the four arm portions 5c and the movable side fixing portion 5a. Moreover, the buffer material 17 is provided between each of the pair of convex portions 5f when viewed from the optical axis direction. That is, the buffer material 17 is provided at four locations at substantially equal angular intervals in the circumferential direction centered on the optical axis L.

  As described above, when the lens driving device 1 is viewed from above, the distal end side and the proximal end side of the arm portion 5c and the peripheral portions of the connecting portion 5d and the convex portion 5f of the movable side fixing portion 5a are visually recognized. It has become. In this embodiment, after assembly of the lens driving device 1 is completed, the lens driving device 1 is cleaned, and then the base end side of the four arm portions 5c with reference to the pair of convex portions 5f from the openings 10d and 12b. The cushioning material 17 is installed by applying a gel-like cushioning material 17 between the pair of convex portions 5f and between the pair of convex portions 5f. As described above, in the present embodiment, the pair of convex portions 5 f serve as a guide for the installation range of the cushioning material 17. In other words, in this embodiment, a pair of convex portions 5 f serving as a guide for the installation range of the buffer material 17 is formed at the installation location of the buffer material 17.

  As described above, the leaf spring 5 is at the reference position where the contact surface 8a of the sleeve 8 and the reference surface 11b of the base member 11 are in contact when no current is supplied to the drive coil 14. Since the movable body 2 is disposed and fixed to the sleeve 8 and the spacer 12 in a bent state, when the gel-like cushioning material 17 is applied, the contact surface 8a and the reference surface 11b And abut.

(Main effects of this form)
As described above, in this embodiment, a buffer is provided at a location straddling the base end side of the arm portion 5 c close to the fixed side fixing portion 5 b fixed to the fixed body 3 and the movable side fixing portion 5 a fixed to the movable body 2. A material 17 is provided. Therefore, the buffer material 17 has an action of absorbing vibration in the optical axis direction of the movable body 2 with respect to the fixed body 3 to shorten the vibration time of the movable body 2. Therefore, in this embodiment, it is possible to converge the vibration in the optical axis direction of the lens held by the movable body 2 in a short time by the action of the buffer material 17.

  For example, in the lens driving device 1, when the buffer material 17 is not provided, the vibration amplitude in the optical axis direction of the movable body 2 relative to the fixed body 3 is attenuated to 10 μm as shown in FIG. However, if the buffer member 17 is provided at four locations in the lens driving device 1, the vibration in the optical axis direction of the movable body 2 with respect to the fixed body 3 as shown in FIG. It takes 30 to 50 msec for the amplitude of the signal to attenuate to 10 μm. Further, in the lens driving device 1, even in the case where the buffer material 17 is provided at two positions on the diagonal line, as shown in FIG. 7C, in the optical axis direction of the movable body 2 with respect to the fixed body 3. The time required for the vibration amplitude to attenuate to 10 μm is 60 to 100 msec. As described above, in this embodiment, it is possible to converge the vibration in the optical axis direction of the lens held by the movable body 2 in a short time by the action of the buffer material 17. 7B and 7C show attenuation characteristics obtained from each of the four samples (sample Nos. 1 to 4 and Nos. 11 to 14).

  In the present embodiment, a pair of convex portions 5 f serving as a guide for the installation range of the buffer material 17 is formed at the installation site of the buffer material 17. Therefore, it is possible to install the cushioning material 17 in an intended amount at a location straddling the base end side of the arm portion 5c and the movable side fixing portion 5a, using the pair of convex portions 5f as a guide. Therefore, in this embodiment, it is possible to set the convergence time of vibration in the optical axis direction of the lens as intended.

  When the cushioning material 17 is provided, the movable body 2 is easy to move in the downward direction (that is, the direction toward the reference position) due to the influence of the cushioning material 17, but the upward direction (that is, the direction away from the reference position). Since it is difficult to move, the area of the region surrounded by the hysteresis curve indicating the relationship between the current value supplied to the driving coil 14 and the amount of movement of the movable body 2 from the reference position may be increased. It may be difficult to control the amount of movement. However, in this embodiment, since the pair of convex portions 5f serving as a guide for the installation range of the cushioning material 17 is formed at the location where the cushioning material 17 is installed, by appropriately setting the interval between the pair of convex portions 5f, It is possible to shorten the convergence time of vibration in the optical axis direction of the lens while reducing the area of the region surrounded by the hysteresis curve. In this embodiment, the balance between the size of the area surrounded by the hysteresis curve and the convergence time of vibration in the optical axis direction of the lens is controlled by appropriately setting the interval between the pair of convex portions 5f. It becomes possible. As the distance between the pair of convex portions 5f is increased and the amount of the buffer material 17 is increased, the convergence time of the vibration in the optical axis direction of the lens is shortened, but the area of the region surrounded by the hysteresis curve is increased. . That is, as the distance between the pair of convex portions 5f is narrowed to reduce the amount of the buffer material 17, the area of the region surrounded by the hysteresis curve decreases, but the convergence time of the vibration in the optical axis direction of the lens increases. .

  In this embodiment, a pair of convex portions 5f are formed on the outer periphery of the movable side fixed portion 5a. Therefore, the installation range of the buffer material 17 can be accurately defined by the pair of convex portions 5f. That is, for example, the installation range of the cushioning material 17 can be reduced by one convex portion formed on the outer periphery of the movable side fixed portion 5a and one convex portion formed on the inner periphery on the proximal end side of the arm portion 5c. When a pair of convex portions serving as a guide is configured, the interval between the convex portions is likely to vary due to variations in the relative positions of the movable-side fixed portion 5a and the arm portion 5c. Since the pair of convex portions 5f are formed on the outer periphery of the fixed portion 5a, variation in the interval between the pair of convex portions 5f can be suppressed. Accordingly, it is possible to accurately define the installation range of the buffer material 17 by the pair of convex portions 5f.

  In this embodiment, a pair of convex portions 5f are formed on the outer periphery of the movable side fixed portion 5a. Therefore, as shown in FIG. 4, even when the width of the movable side fixing portion 5a formed in a substantially annular shape is narrow, the rigidity of the movable side fixing portion 5a can be ensured. That is, when the convex portion 5f is formed on the movable side fixing portion 5a, the width of the portion of the movable side fixing portion 5a where the convex portion 5f is formed is widened, so that the rigidity of the movable side fixing portion 5a is ensured. Is possible.

  In this embodiment, the cushioning material 17 is provided at four locations at substantially equal angular intervals in the circumferential direction centered on the optical axis L. Therefore, the buffer member 17 can absorb the vibration in the optical axis direction of the movable body 2 relative to the fixed body 3 without deviation in the circumferential direction.

  In this embodiment, the buffer material 17 is, for example, a silicon-based gel. Therefore, as described above, the buffer material 17 can be provided at the final stage of the assembly process of the lens driving device 1. Moreover, it becomes possible to ensure the adhesiveness of the buffer material 17 to the leaf spring 5 to which the buffer material 17 is applied.

(Other embodiments)
The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited to this, and various modifications can be made without departing from the scope of the present invention.

  In the form mentioned above, the convex part 5f is formed in the outer periphery of the movable side fixed part 5a. In addition, for example, instead of the convex portion 5f, a convex portion that protrudes inward in the radial direction may be formed on the inner periphery on the proximal end side of the arm portion 5c. In addition, one convex portion 5f is formed on the outer periphery of the movable side fixed portion 5a, and one convex portion is formed on the inner periphery on the proximal end side of the arm portion 5c, and the two convex portions are buffered. It may be an indication of the installation range of the material 17.

  With the form mentioned above, the buffer material 17 is provided in the location straddling the base end side of the arm part 5c, and the movable side fixing | fixed part 5a. In addition to this, as shown in FIG. 8, for example, the cushioning material 17 may be provided at a location straddling the intermediate position of the arm portion 5 c and the movable side fixing portion 5 a. In this case, as shown in FIG. 8, a pair of convex parts 5f may be formed on the outer periphery of the movable-side fixed part 5a, or a pair of convex parts 5c may be formed on the inner periphery of the arm part 5c. A convex part may be formed. In addition, when the shock absorbing material 17 is provided in the location straddling the arm part 5c and the movable side fixing | fixed part 5a, the shock absorbing material 17 is provided in the part straddling the part except the front end side of the arm part 5c, and the movable side fixing | fixed part 5a. Should just be provided. In this way, the buffer member 17 can have a function of absorbing vibration in the optical axis direction of the movable body 2 relative to the fixed body 3 and shortening the vibration time of the movable body 2.

  Moreover, as shown in FIG. 9, the shock absorbing material 17 may be provided in the location straddling the front end side of the arm part 5c, and the fixed side fixing | fixed part 5b. In this case, as shown in FIG. 9, a pair of convex portions 5f may be formed on the outer periphery of each of the four arm portions 5c, or a pair of convex portions may be formed on the fixed-side fixing portion 5b. It may be formed. In addition, when the shock absorbing material 17 is provided in the location straddling the arm part 5c and the fixed side fixing part 5b, the shock absorbing material is provided in the part straddling the portion excluding the base end side of the arm part 5c and the fixed side fixing part 5b. 17 may be provided. In this way, the buffer member 17 can have a function of absorbing vibration in the optical axis direction of the movable body 2 relative to the fixed body 3 and shortening the vibration time of the movable body 2.

  Moreover, the buffer material 17 may be provided in the location straddling the movable side fixing | fixed part 5a and the fixed side fixing | fixed part 5b, and may be provided in the location straddling the movable body 2 and the fixed side fixing | fixed part 5b. Further, it may be provided at a location straddling the fixed body 3 and the movable side fixed portion 5a. Furthermore, the cushioning material 17 may be provided at a position straddling the movable body 2 and the portion excluding the distal end side of the arm portion 5c, or the fixed body 3 and the portion of the arm portion 5c excluding the proximal end side. It may be provided at a location straddling the movable body 2 or at a location straddling the movable body 2 and the fixed body 3. In any case, for example, a convex portion serving as a guide for the installation range of the buffer material 17 is formed at the installation site of the buffer material 17.

  With the form mentioned above, a pair of convex part 5f (namely, two convex part 5f) is formed in the movable side fixing | fixed part 5a in the installation location of the shock absorbing material 17. As shown in FIG. In addition to this, as shown in FIG. 10, for example, three convex portions 5 f may be formed in the state where the shock-absorbing material 17 is installed at a predetermined interval in the movable side fixed portion 5 a. In this case, as shown in FIG. 10 (B), the cushioning material 17 may be provided from the beginning between the two convex portions 5f arranged at both ends of the three convex portions 5f. For example, as shown in FIG. 10A, the cushioning material 17 is provided only between two adjacent convex portions 5f of the three convex portions 5f, and the area of the region surrounded by the hysteresis curve is large. After confirming the balance between the convergence time of vibrations in the optical axis direction of the lens, if necessary, as shown in FIG. 10B, two convex portions 5f on which no buffer material 17 is installed. A cushioning material 17 may be further provided between the two. As described above, when the three protrusions 5f are formed at the location where the cushioning material 17 is installed, the size of the area of the region surrounded by the hysteresis curve is determined using the three protrusions 5f, and the lens It is possible to adjust the balance with the convergence time of vibration in the optical axis direction. Note that three convex portions may be formed on the proximal end side of the arm portion 5c. Further, two convex portions are formed on one of the proximal end side of the arm portion 5c or the movable side fixed portion 5a, and one convex portion is formed on the other side of the proximal end side of the arm portion 5c or the movable side fixed portion 5a. May be.

  Moreover, four or more convex parts 5f may be formed in the installation location of the shock absorbing material 17. FIG. Even in this case, the balance between the size of the area surrounded by the hysteresis curve and the convergence time of the vibration in the optical axis direction of the lens can be adjusted using four or more convex portions 5f. It becomes possible.

  In the embodiment described above, the pair of convex portions 5f serving as a guide for the installation range of the cushioning material 17 is formed on the outer periphery of the movable side fixed portion 5a. In addition to this, as shown in FIG. 11, for example, a pair of recesses 5 g serving as a guide for the installation range of the cushioning material 17 may be formed on the outer periphery of the movable side fixing portion 5 a so as to be recessed radially inward. In this case, the buffer material 17 is provided between the pair of recesses 5g. In addition, a pair of recesses that serve as a guide for the installation range of the cushioning material 17 may be formed in the inner periphery on the proximal end side of the arm portion 5c so as to be recessed radially outward.

  In addition, as shown in FIG. 12, a pair of convex portions 5f and concave portions 5g that serve as a guide for the installation range of the cushioning material 17 may be formed on the outer periphery of the movable side fixed portion 5a. In this case, the buffer material 17 is provided between the convex part 5f and the concave part 5g. Moreover, a pair of convex part and recessed part used as the standard of the installation range of the buffer material 17 may be formed in the inner periphery of the base end side of the arm part 5c.

  In the embodiment described above, the movable side fixing portion 5a is formed in a substantially annular shape. In addition to this, for example, the movable-side fixed portion 5a may be formed in a substantially arc shape and connected to each of the four arm portions 5c. That is, the leaf spring 5 may be composed of one movable side fixing portion 5a, one fixed side fixing portion 5b, and one arm portion 5c. The leaf spring 5 may be configured in the same manner as the leaf spring 6. Moreover, in the form mentioned above, the number of the arm parts 5c with which the leaf | plate spring 5 is provided is 4, However, The number of the arm parts 5c with which the leaf | plate spring 5 is provided may be three, and it is five or more. Also good.

  In the form mentioned above, the buffer material 17 is provided in the location straddling the base end side of the arm part 5c and the movable side fixing | fixed part 5a. In other words, in the embodiment described above, the buffer material 17 is provided on the leaf spring 5. In addition to this, for example, a buffer material 17 may be provided on the leaf spring 6 in addition to or instead of the leaf spring 5.

  In the embodiment described above, the lens driving device 1 is formed so that the shape when viewed from the optical axis direction is substantially square. In addition, for example, the lens driving device 1 may be formed so that the shape when viewed from the optical axis direction is a substantially rectangular shape, or the shape when viewed from the optical axis direction is a substantially hexagonal shape or the like. It may be formed so as to have a substantially polygonal shape. The lens driving device 1 may be formed so that the shape when viewed from the optical axis direction is a substantially circular shape or a substantially elliptical shape.

DESCRIPTION OF SYMBOLS 1 Lens drive device 2 Movable body 3 Fixed body 4 Drive mechanism 5 Leaf spring (spring member)
5a Movable fixed part 5b Fixed fixed part 5c Arm part 5f Convex part 5g Concave part 17 Buffer L L Optical axis Z Optical axis direction

Claims (7)

A movable body that holds a lens and is movable in the optical axis direction of the lens, a fixed body that holds the movable body so as to be movable in the optical axis direction, and a drive for driving the movable body in the optical axis direction A mechanism, a spring member that connects the movable body and the fixed body, and a buffer material having viscoelasticity that absorbs vibration in the optical axis direction of the movable body relative to the fixed body and shortens the vibration time of the movable body And
The spring member includes a movable side fixed portion fixed to the movable body, a fixed side fixed portion fixed to the fixed body, and an arm portion connecting the movable side fixed portion and the fixed side fixed portion. ,
The movable side fixed portion is disposed on the inner peripheral side than the fixed side fixed portion,
When one end of the arm part connected to the movable side fixed part is the tip of the arm part, and the other end of the arm part connected to the fixed side fixed part is the base end of the arm part,
The cushioning material is provided at a location straddling the movable side fixed portion and the base end side of the arm portion,
The lens driving device according to claim 1, wherein a convex portion and / or a concave portion, which serves as a guide for an installation range of the cushioning material, is formed at the location of the cushioning material. The movable side fixing portion is formed in a substantially annular shape or a substantially arc shape,
The arm portion is formed in a substantially arc shape,
The convex portion and / or the recess, the lens driving device according to claim 1, characterized by being formed on one of the inner periphery of the outer periphery or the arm portion of said movable side fixing part. Wherein in the installed position of the cushioning material, the movable-side fixing portion or the arm portion, according to claim 1 or 2, characterized in that at least two of said convex portion is formed in a state with a predetermined gap Lens drive device. In the installation location of the cushioning material, the two movable portions or the two concave portions are formed on the movable side fixed portion or the arm portion at a predetermined interval,
Two of the convex portion or between the two lens driving device according to claim 1 or 2, wherein said buffer material between the recess and being provided. Said spring member is a lens driving device according to claim 1, characterized in that it comprises four of said arms which central angle is formed in a substantially arcuate shape that is approximately 90 ° 4. The buffer material, a lens driving device according to any one of claims 1 to 5, characterized in that are provided at a plurality of positions at substantially equal angular intervals in the circumferential direction about the optical axis of the lens. The buffer material, a lens driving device according to claim 1, characterized in that the viscoelastic composition of the silicon-based 6.

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