JP2016020992A - Lens drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a weight light and minimize power consumption in a lens drive device.SOLUTION: A lens drive device 1 comprises: a lens support body 2 that houses a lens unit; a drive unit 4 that moves the lens support body 2 in an optical axis direction D of a lens; and a magnet support body 6 that supports a magnet 42. The drive unit 4 has: a coil 41 that is arranged around the lens support body 2; a magnet 42 that imparts the coil 41 an electromagnetic field; and the magnet support body 6 that supports the magnet 42. The magnet support body 6 is shaped into a box, and has a magnet mount part 63 which is provided in one side face of the box and to which the magnet 42 is mounted. The lens support body 2 is shaped into a square cylinder, and has a coil reception part 23 which is provided in one side face of an outer periphery of the square cylinder, and in which the coil 41 is received. The lens support body 2 and the magnet support body 6 are arranged so that the coil 41 faces the magnet 42.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lens driving device including a lens support that accommodates an optical system and an actuator that uses a VCM (Voice Coil Motor).

  In recent years, a small camera module used in a portable device such as a smartphone is equipped with an autofocus function. This autofocus function is realized by a lens driving device including a lens support that accommodates an optical member such as a lens, and an actuator that drives the lens support in the optical axis direction. A lens driving device using a VCM (Voice Coil Motor) as an actuator has a simple structure and can be easily reduced in size, and thus is suitably employed in the above-described small camera module (for example, Patent Document 1 and Patent Document 2).

  A general lens driving device using a VCM includes a lens support, a VCM, a spring that urges the lens support in the optical axis direction of the lens, and a main body that stores them. The main body includes a base and a yoke that covers the base from above, and the base and the yoke are each provided with an opening on the optical axis of the lens. The VCM includes a coil fixed to the outer periphery of the lens support and a magnet that applies a magnetic field to the coil, and the lens support is moved in the direction of the optical axis of the lens by the Lorentz force generated by passing a current through the coil. Move to.

JP 2010-190923 A JP 2012-181384 A

  By the way, in the lens driving device using the VCM described in the above-mentioned patent document, a coil is provided so as to wrap around the periphery of the cylindrical lens support. A magnet is used. The magnet has a relatively large weight among the components constituting the VCM, and if four of them are used, the weight of the entire lens driving device also becomes heavy. Further, for example, in the configuration in which the magnet is provided on the lens support, the weight of the lens support itself increases, and the power consumption may increase to obtain the Lorentz force necessary to move the lens support. .

  The present invention solves the above-described problems, and an object thereof is to provide a lens driving device that is light in weight and can reduce power consumption.

  In order to solve the above problems, the present invention provides a lens support that accommodates an optical member including a lens, a base that supports the lens support, and a drive unit that moves the lens support in the optical axis direction of the lens. The drive unit includes a coil disposed around the lens support, a magnet that applies a magnetic field to the coil, and a magnet support that supports the magnet. The magnet support has a box shape and has a magnet mounting portion provided on one side surface to which the magnet is mounted, and the lens support has a rectangular tube shape and one side surface of the outer periphery thereof. The lens support and the magnet support are arranged so that the coil faces the magnet. Characterized in that it is.

  In the lens driving device, the driving unit includes a spring that is disposed between the lens support and the magnet support and adjusts a relative position thereof, and the lens support is movable. When the coil is in a predetermined holding position excluding the upper end position and the lower end position of the range and the coil faces the magnet, it is preferable that no biasing force is applied to the lens support.

  In the lens driving device, the magnet is magnetized so as to have different magnetic poles in a moving direction of the lens support on a surface facing the coil, and the lens support is configured to have a current flowing through the coil. It is preferable that the moving direction is switched from the holding position to the upper end position or the lower end position by switching the direction.

  In the lens driving device, the magnet support has a plurality of first rails provided at at least two corners of the inner periphery thereof and extending in parallel with the optical axis direction of the lens, and the lens support has an outer periphery of the lens support. There are a plurality of second rails provided at at least two corners and extending in parallel with the optical axis direction of the lens, and an interval between the inner periphery of the magnet support and the outer periphery of the lens support is set between the first rail and the first rail. Preferably, it is defined by a ball disposed between the two rails.

  The lens driving device may further include a magnetic yoke that accommodates the magnet support, and the magnet is disposed in parallel with a side surface of the yoke and is attached to the magnet mounting portion by an adhesive while being attached to the magnet mounting portion. It is preferable that it is fixed to the inner side surface.

  In the lens driving device, the Hall element that detects the position of the lens support, a substrate on which the Hall element is mounted, and an outer periphery of the lens support that is attached to a side surface facing the substrate and is mounted on the hole. A detection magnet that applies a magnetic field to the element, and the substrate is disposed along one side surface of the magnet support where the magnet is not disposed, and the first rail and the second rail are It is preferable to be provided at each of the two corners of the magnet support and the lens support close to the substrate.

  According to the present invention, the magnet is mounted on the magnet mounting portion on one side surface of the magnet support 6, and the coil is stored in the coil storage portion provided on the outer side surface of the lens support body, and the lens is driven by them. Therefore, the weight of the entire lens driving device can be reduced. In addition, for example, the weight of the lens support itself can be reduced compared to a configuration in which a magnet is provided on the lens support, and power consumption for obtaining an appropriate Lorentz force sufficient to move the lens support is suppressed. can do.

(A) is a top perspective view of a lens driving device according to an embodiment of the present invention, (b) is a bottom perspective view, (c) is a top view, and (d) is a perspective view with a yoke and magnet support removed. Figure. (A) Exploded perspective view of the lens driving device in top view, (b) is an exploded perspective view in bottom view. (A) thru | or (e) is a perspective view which shows the attachment procedure of the coil and the spring to the lens support body of the said lens drive device. (A) and (b) are the perspective views of the bottom view which show the attachment procedure which connects each electric power feeding terminal of a coil and a board | substrate in the said lens drive device. The horizontal sectional view which passes along the upper part of the magnet of the said lens drive device, and an adhesive agent. (A) is a perspective view showing the relationship between the current direction of the coil at the upper position of the lens support and the magnet in the lens driving device, (b) is a side view, and (c) is the coil at the intermediate position of the lens support. The perspective view which shows the relationship of a magnet, (d) is a side view, (e) is a perspective view which shows the current direction of the coil in the upper position of a lens support body, and the relationship between a magnet, (f) is a side view. (A) is a sectional side view of the lens support in the upper position of the lens driving device, (b) is a sectional side view of the lens support in the middle position, and (c) is a side in the lower position of the lens support. Sectional drawing. The elements on larger scale of the horizontal cross section which passes along the ball | bowl part of the said lens drive device.

  A lens driving device according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1A to 1D and FIGS. 2A and 2B, the lens driving device 1 of this embodiment includes a lens support 2 that houses an optical member (not shown) including a lens, and A magnetic yoke 3 having an opening 30 for accommodating the lens support 2 and transmitting light incident on the lens, a drive unit 4 for moving the lens support 2 in the optical axis direction D of the lens, and a lens support A base 5 that supports the body 2 and supports the yoke 3.

  The lens support 2 has a substantially rectangular tube shape, and includes a tube portion 20 that holds the lens unit and a base portion 21 that supports the tube portion 20. A threaded portion 22 is formed on the inner peripheral surface of the cylindrical portion 20, and is held by screwing the lens unit into the threaded portion 22. The lens support 2 is formed of, for example, a plastic material.

  The drive unit 4 is an actuator that drives the lens support 2 by so-called VCM (Voice Coil Motor), a coil 41 disposed around the lens support 2, a magnet 42 that applies a magnetic field to the coil 41, and this magnet And a magnet support 6 that supports 42. The lens support 2 has a concave coil housing portion 23 that is provided on one side surface of the outer periphery of the lens support body 2 and accommodates the coil 41 (see FIG. 2A).

  The base 5 is a plate-like member having an opening 50 that transmits light emitted from the lens, and the outer shape thereof is substantially the same as the shape of the yoke 3 viewed from below. The base 5 has an engaging portion 51 that engages with the yoke 3. In addition, a convex portion 52 for positioning a spring 8 described later is provided on the periphery of the base 5.

  The magnet support 6 has a substantially box shape slightly smaller than the inner dimension of the yoke 3, is formed of a plastic material, has a rectangular upper surface 61 having an opening 60, and is erected on the base 5 side from the upper surface 61. A side surface 62 of the side. On one side surface of the side surface 62, a magnet mounting portion 63 for mounting the magnet 42 is provided.

  In addition, the magnet support 6 has first rails 64 extending in parallel with the optical axis direction D of the lens at at least two corners of the inner periphery (see FIG. 2A). Moreover, the lens support body 2 has the 2nd rail 24 extended in parallel with the optical axis direction D of a lens in two corners of the outer periphery. The first rail 64 and the second rail 24 are respectively provided at two corners of the magnet support 6 and the lens support 2 that are close to the substrate 44 described later.

  The first rail 64 and the second rail 24 are formed such that the cross sections perpendicular to the optical axis direction D of the lens are V-shaped, and are in contact with the ball 7 at two points. The distance between the outer periphery of the lens support 2 and the inner periphery of the magnet support 6 is defined by the balls 7 disposed between the first rail 64 and the second rail 24. Further, the contact surfaces of the first rail 64 and the second rail 24 with the ball 7 are inclined with respect to the inner peripheral surface of the magnet support 6. The inclination angle is preferably 10 to 15 °.

  In the present embodiment, as shown in FIGS. 2A and 2B, two balls 7 are arranged between the first rails 64 and the second rails 24 in total. The balls 7 are basically true spheres having the same diameter, and at least one pair of the balls 7 provided between the first rail 64 and the second rail 24 has the same shape.

  Further, the magnet support 6 is provided with a substrate 44 on which a Hall element 43 for detecting the position of the lens support 2 is mounted, and the substrate 44 is disposed on one side surface 62 where the magnet 42 of the magnet support 6 is not disposed. A substrate mounting portion 66 having a concave shape is formed (see FIG. 2B). The substrate mounting portion 66 has a convex portion 67 for temporarily fixing the substrate 44, and a hole 44 b corresponding to the convex portion 67 is formed in the substrate 44.

  The substrate 44 is formed of a thin general-purpose substrate, for example, a glass epoxy substrate or a flexible printed circuit board (FPC), and is mounted on the substrate mounting portion 66 so as to be a flat surface with the side surface 62 of the magnet support 6. The The sensing part of the Hall element 43 is led out into the magnet support 6 from a hole 65 provided on the side of the magnet support 6 and faces the lens support 2. The substrate 44 is provided with a wiring terminal 45 for supplying power to the coil 41. The wiring terminal 45 is a land provided on the substrate 44, and a spring 8 described later is electrically connected to the land. An external electrode terminal 44a is formed on the edge of the surface of the substrate 44 where the Hall element 43 or the like is not mounted on the base 5 side. A wiring circuit (not shown) is formed on the substrate 44, and the wiring terminal 45 and the external electrode terminal 44a outside the yoke 3 are electrically connected via the wiring circuit.

  On the outer periphery of the lens support 2, a recess 26 is formed in which a detection magnet 25 that applies a magnetic field to the Hall element 43 is fitted. The Hall element 43 detects the position information of the lens support 2 based on the strength of the magnetic field generated by the detection magnet 25, and controls the camera module control device (on which the lens driving device 1 is mounted) via the wiring circuit of the substrate 44. The position information of the lens support 2 is transmitted. The control device receives this position information, changes the amount of current to the coil 41 supplied via the wiring terminal 45, and feedback-controls the driving position of the lens support 2.

  The coil 41 is obtained by winding and binding copper wires in the same direction on a plane along one side surface of the lens support 2, and lead wires 41 a and 41 b (see FIG. 3 described later) from the start end and the end thereof. a) and (b) are derived respectively. The magnet 42 is a rectangular parallelepiped permanent magnet made of neodymium or the like.

  Further, the drive unit 4 has a spring 8 that feeds power to the coil 41 and is arranged between the lens support 2 and the magnet support 6 to adjust the relative positions thereof. In the present embodiment, two springs 8 are used and are electrically connected individually to the lead wires 41a and 41b led out from the coil 41, respectively. Each spring 8 includes a base portion 8a in contact with the base 5, a corrugated leaf spring portion 8b that applies a biasing force to the lens support 2, a conduction portion 8c that feeds power to the coil 41, a leaf spring portion 8b, and the lens support 2. And a circular arc portion 8d connected to the. The spring 8 has a power supply terminal 8e that extends from the base 8a and supplies power to the apparatus.

  Next, a procedure for attaching the coil 41 to the lens support 2 will be described with reference to FIGS. As shown in FIG. 3A, the lens support 2 has a housing recess 27 that houses the ends of the lead wires 41 a and 41 b led out from the coil 41 on the surface of the base 21 that faces the base 5. Further, the lens support 2 has a lead-out portion 28 for drawing out the lead wires 41 a and 41 b led out from the coil 41 to the housing recess 27 at a position adjacent to the housing recess 27. The drawer portion 28 is formed in a groove shape on one side portion of the base portion 21 from the coil housing portion 23 to the housing recess 27.

  Next, as shown in FIG. 3 (b), the end portions of the lead wires 41 a and 41 b are folded toward the housing recess 27 via the lead-out portion 28. As a result, the end portions of the lead wires 41 a and 41 b can be temporarily held in the housing recess 27. And as shown in FIG.3 (c), the conductive adhesive 46 is apply | coated to the accommodation recessed part 27 in which the edge part of lead wire 41a, 41b was accommodated.

  Further, as shown in FIG. 3D, two springs 8 attached to the lens support 2 are prepared. The lens support 2 has a convex portion 29 for positioning the spring 8 on the surface of the base portion 21 facing the base 5, and the conducting portion 8 c of the spring 8 is a hole portion through which the convex portion 29 is inserted. 8f. Then, as shown in FIG. 3E, the two springs 8 are placed on the lens support 2 so that the convex portions 29 fit into the hole portions 8f, and the conducting portions 8c of the springs 8 are accommodated in the accommodating concave portions 27. By the conductive adhesive 46 applied to the lead wires 41 a and 41 b, the lead wires 41 a and 41 b are bonded to the receiving recesses 27. As a result, the end portions of the lead wires 41 a and 41 b and the conducting portion 8 c of the spring 8 are electrically connected to each other by the conductive adhesive 46 in the housing recess 27. As the conductive adhesive 46, for example, a conductive paste in which conductive metal fine particles are mixed with a synthetic resin such as a silver paste, a silicone resin, or an epoxy resin is used.

  In the conventional lens driving device, many man-hours are required for performing operations such as soldering and bonding of the springs, and the skill of the operator is required, resulting in a decrease in manufacturing yield. On the other hand, in the present embodiment, since the end portions of the lead wires 41a and 41b and the conducting portion 8c of the spring 8 are simply adhered by the conductive adhesive 46, the attaching operation of the spring 8 to the lens support 2 is performed. Therefore, it is possible to improve the manufacturing yield without requiring the skill of the operator. Further, by simply placing the spring 8 on the lens support 2 so that the convex portion 29 fits into the hole 8f, they can be joined in an accurate positional relationship. This embodiment is particularly preferably used in a lens driving device in which the coil 41 is provided on the lens support 2 and a spring is used as a power feeding mechanism for the coil 41.

  The accommodating recess 27 is formed so as to satisfy the normal application capacity of the conductive adhesive 46. Therefore, for example, even when the conductive adhesive 46 is applied to the housing recess 27 so as to rise in a mountain shape, and the conductive portion 8c of the spring 8 is placed thereon, the conductive adhesive 46 may protrude outside. Absent. Thereby, for example, the conductive adhesive 46 used for joining the spring 8 protrudes to the outside, the conductive portion 8c and the base portion 8a are bonded, and the spring performance of the spring 8 is lost. It is possible to suppress problems such as contact with the other spring 8 and short-circuiting.

  Further, as shown in FIG. 3D, the conduction portion 8c has a plurality of minute hole portions 8g in the portion to which the conductive adhesive 46 is bonded. The conductive adhesive 46 generates a small amount of gas during curing, and may cause a conductive failure in which the resistance value during conduction increases due to the influence of the gas. On the other hand, according to the present embodiment, the gas can be discharged from the cured bonded portion by the minute hole portion 8g, and the above-described conductive failure can be suppressed. Moreover, by providing the plurality of minute hole portions 8g in the conductive portion 8c, the bonding area between the conductive adhesive 46 and the conductive portion 8c is increased, and the adhesiveness thereof can be improved. Even when the conductive adhesive 46 is in an uncured state, the spring 8 is positioned by the convex portion 29 of the lens support 2, so that the positional relationship between the spring 8 and the lens support 2 is shifted. Can be suppressed. Therefore, it is possible to obtain the lens driving device 1 with high accuracy in the mounting position accuracy of the spring 8 with respect to the lens support 2 and high reliability.

  Next, the procedure for mounting the substrate 44 and electrical connection to the spring 8 will be described with reference to FIGS. The lens support 2 to which the spring 8 is attached in the above-described procedure is arranged on the magnet support 6 as shown in FIG. The base 8a and the power supply terminal 8e of the spring 8 are formed so as to be placed on the periphery of the magnet support 6 on the base 5 side. Therefore, even when the lens support 2 is fitted into the magnet support 6, the base 8 a and the power supply terminal 8 e are fixed to the periphery of the magnet support 6 on the base 5 side while the conducting portion 8 c is fixed to the lens support 2. It is mounted without shifting. In this state, the substrate 44 is disposed on one side surface 62 of the magnet support 6 so that the wiring terminal 45 is in contact with the power supply terminal 8e of the spring 8 (see also FIG. 2B).

  Next, as shown in FIG. 4B, the wiring terminal 45 of the substrate 44 and the power supply terminal 8 e of the spring 8 are fixed with solder 47. As a result, the substrate 44 is attached to the magnet support 6, and the wiring terminal 45 of the substrate 44 and the power supply terminal 8 e of the spring 8 are electrically connected.

  The magnet support 6 to which the substrate 44 is attached is attached to the yoke 3, and the magnet 42 is attached to the magnet attachment portion 63 of the magnet support 6. As shown in FIG. 5, the magnet 42 is disposed in parallel with the side surface of the yoke 3, and is fixed to the inner side surface of the yoke 3 with an adhesive 6 a while being mounted on the magnet mounting portion 63.

  For example, when the magnet is provided at each corner of the yoke, it is necessary to apply two adhesives to fix one magnet on the inner surface of the two surfaces of the yoke. On the other hand, in the present embodiment, the magnet 42 is arranged in parallel with the side surface of the yoke 3 and is temporarily held by the magnet mounting portion 63 before the adhesive 6a is applied. One point may be applied. Moreover, since there is only one magnet 42, the attaching process of the magnet 42 can be reduced as compared with the conventional lens driving device using a plurality of magnets. Thereby, the assembly process of the lens drive device 1 can be reduced, and productivity can be improved.

  In addition, since the coil is provided so as to wrap around the periphery of the lens support, and there is one magnet 42 as compared with the conventional lens driving device using four magnets for applying a magnetic field from the four sides of the coil, The entire weight of the lens driving device 1 can be reduced. Further, for example, compared to a configuration in which a magnet is provided on the lens support, the weight of the lens support 2 itself can be reduced, and power consumption for obtaining an appropriate Lorentz force sufficient to move the lens support 2 Can be suppressed. Further, in the present embodiment, the range of generating the magnetic field by providing the coil 41 is limited, thereby suppressing the amount of current necessary for driving the lens support 2 and reducing the power consumption of the lens driving device 1. Can be realized.

  The lens driving device 1 assembled in this way controls the amount of current supplied to the coil 41 from the control device (not shown) of the camera module on which the lens driving device 1 is mounted via the wiring terminals 45 and the direction in which the current flows. Thus, the lens support 2 can be driven at an arbitrary position.

  Here, the operation of the lens driving device 1 will be described with reference to FIGS. 6 and 7. First, as shown in FIG. 7B, the spring 8 is arranged so that the lens support 2 is disposed at a predetermined holding position (in this example, an intermediate position) excluding the upper end position and the lower end position of the movable range. The lens support 2 is held. In this state, the spring 8 does not apply a biasing force to the lens support 2 when the coil 41 faces the magnet 42 (see also FIGS. 6C and 6D). The magnet 42 is magnetized on the surface facing the coil 41 so as to have different magnetic poles in the moving direction of the lens support 2. For example, in the illustrated example, the magnet 42 is magnetized so as to have an S pole at the upper position on the surface facing the coil 41 and an N pole at the lower position. The intermediate position here may be either the upper end position or the lower end position, for example, +0.05 to 0.1 mm from the lower end position (longest lens photographing distance) shown in FIG. It is preferable that it is a position.

  And the lens support body 2 is comprised so that the moving direction may switch, when the direction of the electric current which flows into the coil 41 switches. Specifically, as shown in FIGS. 6 (a) and 6 (b), a coil 41 facing the south pole surface of the magnet 42 is supplied with a current in the front direction of the drawing and the coil 42 facing the north pole surface of the magnet 42. When a current in the back direction of the drawing is caused to flow through 41, a Lorentz force in the downward direction of the drawing is generated in the coil 41. As a result, the lens support 2 moves from the holding position shown in FIG. 7B to the lower end position shown in FIG. On the other hand, as shown in FIGS. 6 (e) and 6 (f), a current in the back direction of the drawing is passed through the coil 41 facing the south pole surface of the magnet 42, and the coil 41 facing the north pole surface of the magnet 42 When a forward current is passed, a Lorentz force in the upward direction of the drawing is generated in the coil 41. As a result, the lens support 2 moves from the holding position shown in FIG. 7 (b) to the upper end position shown in FIG. 7 (c).

  In this manner, the lens driving device 1 moves the lens support 2 from the lowest position shown in FIG. 7A to the intermediate position shown in FIG. 7B and the highest position shown in FIG. It can be moved in the range up to. At this time, the distance between the outer periphery of the lens support 2 and the inner periphery of the magnet support 6 is defined by a constant distance by the balls 7 disposed between the first rail 64 and the second rail 24. Then, when the ball 7 rotates between the first rail 64 and the second rail 24, the lens support 2 is guided along the first rail 64 and the second rail 24 extending in parallel with the optical axis direction D of the lens. Thus, the lens support 2 can be moved without tilting from the optical axis direction D of the lens.

  Further, the coil 41 and the magnet face each other at the intermediate position of the lens support 2 shown in FIG. The spring 8 does not apply a biasing force (spring stress) to the lens support 2 when the coil 41 and the magnet are in a position facing each other. That is, when a voltage is applied to the coil 41 to cause a negative current or a positive current to flow and the lens support 2 moves to the position shown in FIG. 7A or 7B due to the generation of Lorentz force, FIG. An urging force is applied to return the lens support 2 to the intermediate position shown in FIG.

  For example, when the spring 8 is set so as not to apply an urging force at the lowest position shown in FIG. 7A, the spring 8 exerts a large urging force on the lens support 2 at the uppermost position shown in FIG. Therefore, in order to hold the lens support 2 at this position, it is necessary to increase the amount of current to the coil 41 in order to generate a large Lorentz force against the urging force of the spring 8, and power consumption is reduced. Get higher.

  On the other hand, in the present embodiment, since it is set so as not to apply a biasing force to the lens support 2 at the intermediate position shown in FIG. 7B, the lowest position shown in FIG. However, even at the uppermost position shown in FIG. 7C, the spring 8 does not apply a large urging force to the lens support 2. Therefore, an appropriate Lorentz force that opposes the urging force of the spring 8 may be generated to hold the lens support 2 at these positions, and a control unit (not shown) of the device in which the lens driving device 1 is incorporated. By switching the direction of the current flowing through the coil 41 in accordance with the above control, it is not necessary to increase the amount of current to the coil 41 more than necessary, and power consumption can be suppressed.

  In addition, according to the present embodiment, the first rail 64 and the second rail 24 are each V-shaped, and are in contact with each other at a total of four points so as to surround the ball 7 from four directions, so that the lens driving device 1 is tilted. Even so, the ball 7 moves between the first rail 64 and the second rail 24 with a constant contact resistance. Therefore, the lens support 2 can be smoothly moved in the optical axis direction D of the lens so as to linearly correspond to the amount of current supplied to the coil 41. In addition, the first rail 64, the second rail 24, and the ball 7 are provided so as to fit in the gap between the two corners of the rectangular tube-shaped magnet support 6 and the lens support 2, so that these configurations are accommodated. There is no need to provide a separate space, and an increase in the size of the lens driving device 1 can be suppressed.

  Furthermore, according to the present embodiment, since the rails 64, 24 and the ball 7 are provided on the two sides of the lens driving device 1, even if the camera module is tilted when the VCM is driven, the rails 64, 24 and the ball 7 are The lens support 2 is appropriately moved along the optical axis direction D of the lens. Therefore, it is possible to effectively suppress the tilt when the lens support 2 is driven.

  According to the embodiment, since the spring 8 is arranged between the lens support 2 and the magnet support 6, the spring stress of the spring 8 reduces the vibration of the lens support 2 when the camera module is not in operation. can do. Therefore, for example, when the portable device using the lens driving device 1 is carried, the lens support 2 does not move and does not generate an unpleasant noise.

  By the way, depending on the processing accuracy of the first rail 64 and the second rail 24, a slight gap may be formed between the first rail 64 and the second rail 24 and the ball 7. On the other hand, according to this embodiment, as shown in the enlarged view of FIG. 8, the lens support 2 is caused to detect the detection magnet 25 by the attractive force between the magnetic yoke 3 and the detection magnet 25. Is attracted to the side surface 62 side of the yoke 3 facing the above, and the gap is eliminated. Therefore, an adhesive force necessary to move the lens support 2 along the first rail 64 and the second rail 24 is generated between the first rail 64 and the second rail 24 and the ball 7. it can.

  Further, according to the present embodiment, the contact surfaces of the first rail 64 and the second rail 24 with the ball 7 are inclined with respect to the inner peripheral surface of the magnet support 6. If the contact surface is not inclined, as shown in the right dashed line column in FIG. 8, the first rail 64, the second rail 24, and the ball 7 are contact surfaces in the suction direction by the detection magnet 25. It is possible that the contact is made only at the point P1 (illustrated). On the other hand, in the present embodiment, since the contact surfaces of the first rail 64 and the second rail 24 and the ball 7 are inclined, the attractive force by the detection magnet 25 also works in the inclined direction, and the first The rail 64 and the second rail 24 and the ball 7 are in contact with each other at both V-shaped contact surfaces (points P1 and P2 shown). Therefore, the adhesive force necessary for moving the lens support 2 along the first rail 64 and the second rail 24 can be effectively generated, and the inclination of the lens support 2 with respect to the optical axis during driving can be increased. It can suppress more effectively.

  In addition, this invention is not restricted to the said embodiment, A various deformation | transformation is possible. For example, in the above-described embodiment, the first rail 64 and the second rail 24 are configured to be provided at the corners close to the substrate 44 on the side opposite to the coil 41 and the magnet 42. And the 2nd rail 24 may be provided in the corner part of the vicinity of the side surface in which the coil 41 and the magnet 42 were provided. In the above embodiment, the lens support 2 is placed between the first rail 64 and the second rail 24 and the ball 7 by the attractive force between the magnetic yoke 3 and the detection magnet 25. The adhesive force required to move along the 64 and the second rail 24 was generated. On the other hand, in the above configuration, for example, a magnetic plate (not shown) is provided in the vicinity of the coil 41 of the lens support 2, and the lens is supported by the attractive force between the magnetic plate and the magnet 42. An adhesive force necessary to move the body 2 along the first rail 64 and the second rail 24 may be generated.

DESCRIPTION OF SYMBOLS 1 Lens drive device 2 Lens support body 23 Coil accommodating part 24 2nd rail 25 Detection magnet 3 Yoke 4 Drive unit 41 Coil 42 Magnet 5 Base 6 Magnet support body 6a Adhesive 63 Magnet mounting part 64 1st rail 43 Hall element 7 Ball 8 Spring D Optical axis direction of lens

Claims (6)

A lens driving device comprising: a lens support that contains an optical member including a lens; a base that supports the lens support; and a drive unit that moves the lens support in the optical axis direction of the lens,
The drive unit includes a coil disposed around the lens support, a magnet that applies a magnetic field to the coil, and a magnet support that supports the magnet.
The magnet support has a box shape, and has a magnet mounting portion provided on one side surface to which the magnet is mounted,
The lens support has a rectangular tube shape, and has a coil housing portion that is provided on one side surface of the outer periphery of the lens support body and houses the coil.
The lens driving device, wherein the lens support and the magnet support are arranged so that the coil faces the magnet. The drive unit includes a spring that is disposed between the lens support and the magnet support and adjusts their relative positions;
The spring does not apply an urging force to the lens support when the lens support is in a predetermined holding position excluding the upper end position and the lower end position of the movable range and the coil faces the magnet. The lens driving device according to claim 1. The magnet is magnetized on the surface facing the coil so as to have different magnetic poles in the moving direction of the lens support,
The lens support body is configured to switch its moving direction from the holding position to the upper end position or the lower end position by switching the direction of the current flowing through the coil. The lens drive device described in 1. The magnet support has a plurality of first rails provided at at least two corners of the inner periphery thereof and extending in parallel with the optical axis direction of the lens,
The lens support has a plurality of second rails provided at at least two corners of the outer periphery thereof and extending parallel to the optical axis direction of the lens,
The distance between the inner periphery of the magnet support and the outer periphery of the lens support is defined by a ball disposed between the first rail and the second rail. The lens driving device according to any one of claims. A magnetic yoke that accommodates the magnet support;
5. The lens drive according to claim 4, wherein the magnet is disposed in parallel with a side surface of the yoke, and is fixed to an inner side surface of the yoke with an adhesive while being mounted on the magnet mounting portion. apparatus. A Hall element that detects the position of the lens support, a substrate on which the Hall element is mounted, and a detection that is attached to one side of the outer periphery of the lens support that faces the substrate and applies a magnetic field to the Hall element And a magnet for
The substrate is disposed along one side surface of the magnet support where the magnet is not disposed,
6. The lens driving device according to claim 5, wherein the first rail and the second rail are respectively provided at two corners of the magnet support and the lens support close to the substrate.