JP7071585B2 - Lens drive device - Google Patents

Description

The technique of the present disclosure relates to a lens driving device.

An image pickup device such as a digital camera is generally equipped with a shake correction mechanism in order to prevent shake of the subject image due to camera shake or the like. The image stabilization mechanism is an electronic image stabilization mechanism that corrects the image stabilization by cutting out a predetermined range from the subject image captured by the image sensor, and an optical image system that corrects the image stabilization by changing the position of the lens and / or the image sensor. There is a correction. Among the optical correction methods, the lens shift method is a method of obtaining a subject image in which shake is suppressed by moving the lens for correction to change the direction of the optical axis.

The lens shift method is generally configured to correct the runout in the pitch direction and the yaw direction of the optical axis of the lens. That is, it is common to perform runout correction by moving the correction lens in a plane orthogonal to the optical axis.

Patent Document 1 discloses a method in which a rolling member is sandwiched between attractive magnets and a movable member is urged to a fixed member by an attractive force by magnetism.

Further, Patent Document 2 discloses an image blur correction device that urges a lens frame to a base member by a mooring member (coil spring). In Patent Document 2, a method of engaging a swingable guide arm with a lens frame to regulate the rotation of the lens frame is used.

Japanese Unexamined Patent Publication No. 2012-118517 International Publication WO2017 / 090478 Gazette

One embodiment of the present disclosure provides a lens driving device for runout correction.

The lens driving device according to the first aspect has a holding portion that holds a lens for vibration correction, a base portion that supports the holding portion so as to be displaceable along a surface intersecting the optical axis of the lens, and a lens of the holding portion. At least two 2-pole magnets and at least two 2-pole magnets, each of which has different magnetic poles arranged adjacent to each other in a direction intersecting the optical axis of the lens, fixed at positions corresponding to the periphery of the lens at predetermined intervals. Correspondingly, the axis of each coil is along the optical axis of the lens, at least two coils arranged at the base, and at least one of at least two two-pole magnets at the base and along the optical axis. Includes a magnetic material fixed at a position where it overlaps in the vertical direction.

The lens driving device according to the second aspect has a holding portion that holds the lens for vibration correction, a base portion that supports the holding portion so as to be displaceable along a surface intersecting the optical axis of the lens, and a lens of the holding portion. Each coil axis corresponds to at least two coils along the optical axis of the lens and each of the at least two coils, fixed at predetermined intervals at positions corresponding to the perimeter of the lens. Along the optical axis with at least two 2-pole magnets fixed to the base and at least one of the at least two 2-pole magnets in the holder or coil, with the magnetic poles adjacent to each other in the direction intersecting the optical axis of the lens. Includes a magnetic material fixed at a position where it overlaps in the vertical direction.

In the lens driving device according to the third aspect, the magnetic material is positioned so as to overlap each of the two or four two-pole magnets in the direction along the optical axis, and the direction along the boundary line of the magnetic poles of the two-pole magnets. One by one is arranged at a position deviated from the center of the two-pole magnet, and half of the magnetic materials are arranged deviated from the center of the two-pole magnet in a direction different from the other half.

In the lens driving device according to the fourth aspect, the magnetic bodies are arranged one by one at corresponding positions across the center of the two-pole magnet along the boundary line.

In the lens driving device according to the fifth aspect, a pair of a 2-pole magnet and a coil corresponding to the 2-pole magnet is arranged at a position corresponding to the optical axis.

In the lens driving device according to the sixth aspect, the coil has a length tangential to the circumference of the lens longer than the length in the radial direction of the lens, and the bipolar magnet has a flat rectangular shape long in the tangential direction to the circumference of the lens. be.

The lens driving device according to the seventh aspect has at least three support portions that support the holding portion with respect to the base portion.

In the lens driving device according to the eighth aspect, the support portion is a rolling element.

In the lens driving device according to the ninth aspect, the Hall element is arranged at the base portion at a position corresponding to the midpoint of the boundary line of the magnetic poles of the two-pole magnet and the direction along the optical axis.

In the lens driving device according to the tenth aspect, the Hall element is arranged in the holding portion or the coil at the position corresponding to the midpoint of the boundary line of the magnetic poles of the two-pole magnet and the direction along the optical axis.

According to one embodiment of the present disclosure, a lens driving device for runout correction is provided.

It is a perspective view which shows the correction lens unit which concerns on Embodiment 1. FIG. It is an exploded perspective view of the correction lens unit shown in FIG. It is a front view of the correction lens unit which concerns on Embodiment 1 as seen from the subject side along the optical axis. It is a schematic diagram which shows the positional relationship between one Hall element and a 2-pole magnet. It is a schematic diagram which shows the positional relationship between the other Hall element and a two-pole magnet. FIG. 3 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a cross-sectional view taken along the line BB of FIG. It is a schematic diagram which shows the positional relationship between a 2-pole magnet and a magnetic material seen from the image sensor side along the optical axis. It is a conceptual diagram which shows the strength of the magnetic field in the radial direction of the lens of a 2-pole magnet. It is a conceptual diagram which shows the strength of the magnetic field in the tangential direction around the lens of a 2-pole magnet. It is a conceptual diagram which shows the change of the force which a 2-pole magnet gives to a magnetic body when a holding part rotates. It is an exploded perspective view which shows the correction lens unit which concerns on Embodiment 2. FIG. It is a schematic diagram which shows the positional relationship between a two-pole magnet and a magnetic material seen from the image pickup element side along the optical axis of Embodiment 2. FIG. 13 is a cross-sectional view taken along the line CC of FIG. It is an exploded perspective view which shows the correction lens unit which concerns on Embodiment 3. FIG. It is a schematic diagram which shows the positional relationship between a two-pole magnet and a magnetic material seen from the image pickup element side along the optical axis of Embodiment 3. FIG. It is a schematic diagram which shows the positional relationship between a 2-pole magnet and a magnetic body seen from the image pickup element side along the optical axis of the correction lens unit which concerns on Embodiment 4. FIG. It is a schematic diagram which shows the positional relationship between a 2-pole magnet and a magnetic material seen from the image pickup element side along the optical axis of the correction lens unit which concerns on Embodiment 5. FIG. It is an exploded perspective view which shows the correction lens unit which concerns on Embodiment 6.

(Embodiment 1)
Hereinafter, an example of the embodiment of the technique of the present disclosure will be described with reference to the drawings. The directions in the drawing will be described with reference to the directions indicated by the X-axis, Y-axis, Z-axis and the like shown in the figure. The direction of the arrow on each axis is the + (plus) side or the positive direction, and the opposite direction is the- (minus) side or the negative direction. When + and-are not described, only the axial direction is shown. Further, when the terms "upper", "lower", "right", and "left" are used, they simply mean the upper, lower, right, and left directions in the drawing, and do not mean the absolute direction, unless otherwise specified.

As an example, the correction lens unit 1 shown in FIG. 1 includes a lens 20 for optical shake correction used in an image pickup apparatus such as a digital camera, and a mechanism for driving the lens 20. The drive mechanism that drives the lens 20 of the correction lens unit 1 is an example of the "lens drive device" according to the technique of the present disclosure. The lens 20 is driven by a so-called voice coil motor using a two-pole magnet and a coil, which is a part of the drive mechanism. In the present embodiment, four voice coil motors are provided, but in FIG. 1, a voice coil motor in which a 2-pole magnet 22B and a coil 40B are combined and a voice coil motor in which a 2-pole magnet 22C and a coil 40C are combined are provided. And are illustrated. The voice coil motor is controlled by a control unit (not shown) mounted on the image pickup apparatus, and drives the lens 20 to a position where the shake is corrected.

The four voice coil motors are located in the plane intersecting the optical axis OA of the lens 20 located at the initial position, preferably in the plane orthogonal to the optical axis OA of the lens 20, in the circumferential direction centered on the optical axis OA. Are arranged at predetermined intervals, preferably at equal intervals in the circumferential direction.

Hereinafter, the origin of the coordinates is aligned with the center of the lens 20, the Z axis is aligned with the optical axis of the optical system of an image pickup device such as a camera, the positive direction of the Z axis is toward the subject, and the positive direction of the Y axis is. The three-dimensional XYZ coordinate system is set and described so as to face upward. The negative direction of the Z axis faces the image sensor side.

The correction lens unit 1 is provided inside the optical system of the image pickup device (not shown), and when runout correction is not performed, the optical axis OA of the lens 20 coincides with the optical axis of the optical system of the image pickup device. .. The position of the lens 20 in which the optical axis OA of the lens 20 coincides with the optical axis of the optical system of the image pickup apparatus is referred to as an initial position of the lens 20. The initial position of the lens 20 is a reference position when explaining the displacement of the lens 20. When performing shake correction, the lens 20 is moved from the initial position on the XY plane to change the optical axis direction of the optical system of the image pickup apparatus to perform shake correction. In the following description of the configuration of the correction lens unit 1, unless otherwise specified, the configuration of the lens 20 in the initial position will be described.

The position of the lens 20 is determined by detecting the displacement of the lens 20 in the X-axis direction and the Y-axis direction, respectively, by using the Hall element 14A and the Hall element 14B, which are magnetic sensors. The Hall elements 14A and 14B are arranged at both ends of a flexible printed circuit board (FPC: Flexible Printed Circuits) 12 constituting a flat plate-shaped electronic circuit. The flexible printed circuit board is a member formed by integrating signal cables and / or power cables in a flat plate shape. In the present embodiment, the FPC 12 is a flat plate in which signal cables and the like connecting the Hall elements 14A and 14B and a control unit (not shown) are integrated. By using FPC, the wiring structure is simplified and the correction lens unit 1 is compactly configured. The FPC 12 is supported by the sensor support portion 10. The sensor support portion 10 is fixed to the base portion 50.

In the present specification, when it is explained that a member is fixed to the base portion 50 or is arranged on the base portion 50, it is only when the member is directly fixed or arranged on the base portion 50. It also means that a member is fixed or arranged via another component attached to the base portion 50.

The lens 20 and the four voice coil motors are arranged between the base portion 50 and the sensor support portion 10. The position of the base portion 50 does not change in the XYZ coordinate system. The position of the lens 20 changes in the XYZ coordinate system. That is, the position of the lens 20 is displaced with respect to the base portion 50. Since the sensor support portion 10 is fixed to the base portion 50, the position of the sensor support portion 10 does not change in the illustrated XYZ coordinate system.

As an example, as shown in FIG. 2, the lens 20 is held by the holding portion 21. The holding portion 21 has four two-pole magnets 22A, 22B, 22C, and 22D fixed at predetermined intervals at positions corresponding to the periphery of the lens 20.

The two-pole magnet in the present embodiment means a magnet in which an N pole and an S pole are arranged adjacent to each other in one surface of the magnet. A magnet in which an N pole and an S pole are arranged adjacent to each other in one plane is, for example, magnetized so that the N pole and the S pole are adjacent to each other on a plane of one magnetic material. Alternatively, a magnet in which the north pole plane and the south pole plane of the two magnets are separated from each other in an adjacent or parallel manner may be used.

In the following, when it is not necessary to distinguish between the four 2-pole magnets 22A to 22D, the term “2-pole magnet 22” will be described. The same applies to other members having a plurality of members of the same type. The 2-pole magnet 22 is formed in a flat rectangular shape in which the length in the tangential direction with respect to the circumference of the lens 20 is longer than the length in the radial direction (radial direction). With this configuration, the driving force of the two-pole magnet 22 and the coil 40 can be increased in a compact configuration. Further, the S pole and the N pole of each of the two-pole magnets are arranged side by side in the radial direction of the lens 20.

To specifically explain the arrangement of the two-pole magnet 22, the two-pole magnet 22B and the two-pole magnet 22D are arranged on opposite sides in the direction from the optical axis OA to the X-axis. Both ends of the 2-pole magnet 22B are fixed by magnet support portions 24B, respectively. Both ends of the 2-pole magnet 22D are fixed by magnet support portions 24D, respectively.

On the other hand, a two-pole magnet 22C and a two-pole magnet 22A are arranged on opposite sides in the direction from the optical axis OA to the Y axis, respectively. Both ends of the 2-pole magnet 22C are fixed by magnet support portions 24C, respectively. Both ends of the 2-pole magnet 22A are fixed by magnet support portions 24A.

In this embodiment, the two-pole magnets 22A to 22D are arranged around the lens 20 at 90 ° intervals. The two-pole magnets 22A to 22D constitute four sets of voice coil motors together with the corresponding coils 40A to 40D. Two sets of voice coil motors composed of the two-pole magnets 22A and 22C and the corresponding coils 40A and 40C drive the holding portion 21 in the Y-axis direction. Two sets of voice coil motors composed of the two-pole magnets 22B and 22D and the corresponding coils 40B and 40D drive the holding portion 21 in the X-axis direction.

Each of the coils 40A to 40D is formed in an elongated flat shape. Further, each of the coils 40A to 40D is arranged so that the length direction corresponds to the length direction of the two-pole magnets 22A to 22D.

Further, as will be described later, the Hall element 14A described above is correspondingly arranged on the 2-pole magnet 22B, and the Hall element 14B described above is correspondingly arranged on the 2-pole magnet 22C.

The holding portion 21 has three ball contact portions 26A, 26B, and 26C at positions corresponding to the periphery of the lens 20. The ball contact portions 26A to 26C are arranged at positions where the side facing the base portion 50 comes into contact with the ball, as will be described later. The ball contact portions 26A to 26C are not necessarily arranged at equal intervals. The reason is that the two-pole magnets 22A to 22D are arranged at 90 ° intervals, and if the three ball contact portions 26A to 26C are arranged at equal intervals, they interfere with the positions of the two-pole magnets 22A to 22D. .. The three ball contact portions 26A to 26C may be arranged at equal intervals by providing a ball contact portion 26 on any of the two-pole magnets 22.

In the present embodiment, each of the ball contact portions 26A to 26C is arranged so that the ball 30C is located at the apex of an isosceles triangle whose base is a line segment connecting the ball 30A and the ball 30B.

The ball contact portions 26A to 26C are integrally formed with the holding portion 21. The holding portion 21 has a structure in which two-pole magnets 22A to 22D can be attached around the holding portion 21. In the example shown in FIG. 2, the holding portion 21 uses a member different from that of the lens 20. However, without using a member different from the lens 20, for example, the outer peripheral portion of the lens 20 to which the luminous flux is not incident can be widened and formed as the holding portion 21. In this case, the ball contact portions 26A to 26C may be formed on the holding portion 21 made of the same material as the lens 20, and the two-pole magnets 22A to 22D may be attached. For example, the description "having a 2-pole magnet at a position corresponding to the periphery of the lens 20 of the holding portion" may indicate that the 2-pole magnet may be attached to the holding portion 21 formed on the outer peripheral portion of the lens 20. It means that it may be attached to the holding portion 21 attached to the lens 20 as a separate member.

A known configuration can be used for the accommodating portion that accommodates the holding portion 21 that holds the lens 20 so as not to fall off from the correction lens unit 1, and the description and illustration thereof will be omitted.

As shown in FIG. 2, the base portion 50 has a bottom surface 56 having a surface orthogonal to the optical axis OA, and side wall portions 52A, 52B, 52C, 52D rising from the bottom surface 56 in the direction along the optical axis OA. .. The sensor support portion 10 is fixed to the end portion on the subject side in the direction along the optical axis of the side wall portions 52A, 52B, 52C, and 52D. The base portion 50 is made of a non-magnetic material, that is, a material that is not magnetized even when placed in a magnetic field. In addition, in the present specification, "orthogonal" means not only orthogonality in a strict sense but also orthogonality including optically and / or functionally acceptable error.

Four magnetic bodies 60A, 60B, 60C, and 60D are arranged on the base portion 50 so as to correspond to each of the two-pole magnets 22A, 22B, 22C, and 22D, respectively. Specifically, the magnetic body 60B and the magnetic body 60D are fixed on the opposite sides of the optical axis OA along the X-axis. The magnetic body 60B is fixed to the inside of the recess 62B recessed from the bottom surface 56 of the base portion 50. The magnetic body 60D is fixed to the inside of the recessed portion 62D in the same manner as the recessed portion 62B. The term "magnetic material" as used herein means a member having a property that when it is placed in a magnetic field, it is magnetized to generate magnetism, and when the magnetic field disappears, its own magnetism also disappears. When the magnetic field disappears, a material that generates a residual magnetic field to the extent that the drive by the voice coil motor and the displacement amount detection by the Hall element 14 are not affected, or a material that exhibits ferromagnetism may be used. Specifically, it is a member composed of, for example, a metal such as iron, nickel, cobalt, ferrite, an alloy thereof, and / or an oxide thereof.

On the other hand, the magnetic body 60C and the magnetic body 60A are fixed on the opposite sides of the base portion 50 in the directions from the optical axis OA to the Y axis. The magnetic body 60C is fixed to the inside of the recessed portion 62C in the same manner as the recessed portion 62B. The magnetic body 60A is fixed to the inside of the recessed portion 62A in the same manner as the recessed portion 62B. The recesses 62A to 62D have a depth such that the magnetic bodies 60A to 60D do not protrude from the bottom surface 56 in the direction along the optical axis OA.

Further, four coils 40A, 40B, 40C, and 40D are arranged on the base portion 50. Specifically, the coil 40B and the coil 40D are fixed on the opposite sides of the optical axis OA along the X axis, and the coil 40C and the coil are on the opposite sides of the optical axis OA along the Y axis. 40A is fixed. In the coil 40, the axes of the coils 40A to 40D are arranged in the direction along the optical axis OA of the lens 20. The axis of the coil is the winding axis of the coil. The coils 40A to 40D are all air-core coils.

In addition, in the present specification, "along" in the case of "along the optical axis" or "along a certain direction" is parallel in a parallel direction or within a range including an error that is optically and / or functionally acceptable. Means the direction.

The coil 40 is formed in a flat shape in which the length in the tangential direction with respect to the circumference of the lens 20 is longer than the length in the radial direction. With this configuration, the driving force of the two-pole magnet 22 and the coil 40 can be increased in a compact configuration.

The four coils 40A to 40D are fixed to the bottom surface 56 at positions corresponding to the recesses 62A to 62D, respectively. The magnetic bodies 60A to 60D are arranged in the recesses 62A to 62D, respectively, but the magnetic bodies 60A to 60D do not protrude from the bottom surface 56 in the direction along the optical axis OA, so that they do not interfere with the coils 40A to 40D. not.

Further, three ball accommodating portions 54A, 54B, and 54C are provided on the bottom surface 56 of the base portion 50. The ball accommodating portions 54A, 54B, 54C have a receiving hole in the central portion thereof, and receive the balls (rollers) 30A, 30B, 30C inside the receiving hole. The balls 30A to 30C are rotatably received by the ball accommodating portions 54A to 54C. As will be described later, the balls 30A to 30C project further toward the subject than the end of the optical axis OA of the ball accommodating portions 54A to 54C in the direction toward the subject. The balls 30A to 30C protruding from the ball accommodating portions 54A to 54C abut with the ball contact portions 26A to 26C of the base portion 50, respectively.

As described above, the lens 20 and the two-pole magnets 22A to 22D held by the holding portion 21 are movable with respect to the base portion 50. On the other hand, since the sensor support portion 10 is fixed to the base portion 50, it is not movable with respect to the base portion. That is, the lens 20 and the two-pole magnets 22A to 22D held by the holding portion 21 are separated from the sensor supporting portion 10.

Next, the arrangement relationship between the two-pole magnet 22 and the Hall element 14 will be described. As an example, as shown in FIG. 3, the two-pole magnet 22C and the Hall element 14B overlap each other along the optical axis OA. Further, the two-pole magnet 22B and the Hall element 14A overlap with each other along the optical axis OA. The fact that the 2-pole magnet 22 and the Hall element 14 overlap along the optical axis OA means that when projected onto a plane orthogonal to the optical axis OA, the projected image region of the 2-pole magnet 22 in the optical axis OA direction and the Hall element It means that it overlaps with the projected image region of 14 in the optical axis OA direction.

As an example, as shown in FIG. 4, in the 2-pole magnet 22C, the north pole and the south pole are arranged adjacent to each other in the direction intersecting the optical axis OA of the lens 20. In the present embodiment, the north pole and the south pole are arranged adjacent to each other in the direction orthogonal to the optical axis OA of the lens 20, that is, in the radial direction of the lens 20. Therefore, it has a boundary line MB between the N pole and the S pole in the tangential direction of the circumference of the lens 20.

The Hall element 14B is arranged at a position corresponding to the midpoint CP of the boundary line MB of the magnetic pole of the two-pole magnet 22C and the optical axis OA direction. The Hall element 14B is arranged along the optical axis OA so as to straddle the boundary line MB along the X-axis direction of the two-pole magnet 22C. By arranging the Hall element 14B in this way, the Hall element 14B can accurately detect the amount of change in the magnetic field in the Y-axis direction near the boundary line MB. That is, the Hall element 14B can accurately detect the amount of displacement of the 2-pole magnet 22C in the Y-axis direction.

Further, as shown in FIG. 5, the 2-pole magnet 22B has a boundary line MB which is a boundary line between the N pole and the S pole in the direction along the Y axis. The Hall element 14A is arranged at a position corresponding to the midpoint CP of the boundary line MB of the magnetic pole of the two-pole magnet 22B and the optical axis OA direction. The Hall element 14A is arranged along the optical axis OA so as to straddle the boundary line MB. By arranging the Hall element 14A in this way, the Hall element 14A can accurately detect the amount of change in the magnetic field in the X-axis direction near the boundary line MB. That is, the Hall element 14A can accurately detect the amount of displacement of the two-pole magnet 22B in the X-axis direction.

The Hall elements 14A and 14B detect the amount of displacement of the holding portion 21 in the X-axis direction and the Y-axis direction. This enables runout correction control that calculates and moves the correction amount in the orthogonal biaxial directions, and the runout correction control program compared to runout correction control that calculates and moves the correction amount in the non-orthogonal biaxial directions. It will be easy. Therefore, the responsiveness of the runout correction becomes faster.

The Hall element 14 is fixed to the sensor support portion 10. Since the sensor support portion 10 is fixed to the base portion 50, the Hall element 14 is fixed to the base portion 50.

As an example, as shown in the cross-sectional view of FIG. 6, the two-pole magnet 22C and the Hall element 14B overlap each other along the optical axis OA direction, but are separated from each other. The Hall element 14B is fixed to the sensor support portion 10 and connected to the FPC 12 which is an electronic circuit. The relationship between the 2-pole magnet 22B and the Hall element 14A is the same (not shown).

The boundary line MB of the magnetic poles of the two-pole magnet 22 is shown by a dotted line in FIGS. 4 to 6 for the sake of explanation. In the present embodiment, since the 2-pole magnet 22 has the N pole and the S pole adjacent to each other in the radial direction orthogonal to the optical axis OA of the lens 20, the boundary line MB exists in the tangential direction around the lens 20. do. Further, although the N pole is located on the center side of the lens 20 and the S pole is located on the outer peripheral side of the lens 20, the S pole and the N pole may be in opposite positions.

Next, a method of supporting the lens 20, that is, the holding portion 21, will be described. As an example, as shown in FIG. 7, the ball 30C protrudes further in the Z-axis + side direction from the upper end portion (+ side direction end portion of the Z-axis) 54CTOP of the ball accommodating portion 54C. The ball 30C is in contact with the holding portion support surface 27C, which is the Z-axis-side surface of the ball contact portion 26C of the holding portion 21 that holds the lens 20. Although not shown in FIG. 7, similarly, for the ball 30A and the ball 30B, the holding portion support surface 27A, which is the Z-axis-side surface of the ball contact portion 26A and 26B of the holding portion 21, respectively. It is in contact with 27B. With this configuration, the holding portion 21 is supported with respect to the base portion 50 so as to be displaceable in the XY plane in a state of being in contact with the balls 30A to 30C.

As shown in the above configuration, the holding portion 21 for holding the lens 20 is supported at three points by the base portion 50 via the balls 30A to 30C. More specifically, the holding portion 21 is supported by the base portion 50 so as to be displaceable along a surface of the lens 20 that intersects the optical axis OA. In the present embodiment, the surface intersecting the optical axis OA is a surface orthogonal to the optical axis OA.

The plane passing through the three contact points between the balls 30A to 30C and the holding portion support surfaces 27A to 27C constitutes the drive surface of the lens 20 orthogonal to the optical axis OA. The drive surface is a plane on which the lens 20, that is, the holding portion 21 is driven. The balls 30A to 30C correspond to a part of the "support portion" according to the technique of the present disclosure. At least three balls 30A to 30C may be used. This is because the drive surface can be defined if there are at least three.

The "support portion" according to the technique of the present disclosure is not limited to the ball 30. For example, a rod-shaped support whose contact portion with the holding portion support surfaces 27A to 27C may be a curved surface having a low frictional force may be used. Alternatively, it may be a flat support portion that is in flat contact with the holding portion support surfaces 27A to 27C. In that case, the frictional force during driving can be reduced by arranging the lubricant on the contact surfaces with the holding portion support surfaces 27A to 27C.

Next, the positional relationship between the two-pole magnet 22 and the magnetic body 60 will be described. As an example, as shown in FIG. 8, the two-pole magnet 22 and the magnetic body 60 are arranged so as to overlap each other in the direction along the optical axis OA. The magnetic material 60A overlaps with the two-pole magnets 22D, and similarly, the magnetic materials 60B to 60D overlap with the two-pole magnets 22B to 22D, respectively. In the present embodiment, the magnetic material 60 is arranged so as to overlap the central portion of the corresponding two-pole magnet 22.

The operation of the correction lens unit 1 having the above structure will be described. First, the strength of the magnetic field formed by the two-pole magnet 22 will be described.

As shown in FIG. 9, the strength of the magnetic field along the Y-axis (radial direction of the lens 20) of the 2-pole magnet 22 is maximum at the center of each of the N-pole surface and the S-pole surface, and decreases toward both ends. Become. The magnetic body 60C is arranged at the center of the two-pole magnet 22 at the initial position, that is, at a position where the magnetic field distribution in the radial direction becomes uniform. Since the magnetic body 60C is magnetized by the magnetic field of the two-pole magnet 22, both attract each other.

Further, as shown in FIG. 10, the strength of the magnetic field along the X axis (tangential direction of the circumference of the lens 20) of the two-pole magnet 22 is maximum at the central portion and decreases toward both ends. The magnetic body 60C is arranged at the center of the two-pole magnet 22 at the initial position, that is, at a position where the magnetic field distribution in the circumferential tangential direction becomes uniform.

As an example, as shown in the upper figure of FIG. 11, in the initial position, the magnetic body 60C is arranged so as to overlap the central portion of the two-pole magnet 22C. Therefore, for example, the strength of the magnetic field in the tangential direction around the intersections G1 and G2 of the right side surface and the left side surface of the magnetic body 60C at the position where the strength of the magnetic field in the radial direction (Y-axis direction) is maximum is H0. Is the same. The magnetic body 60C is magnetized by the magnetic field of the two-pole magnet 22C, and an attractive force acts between the magnetic body 60C and the two-pole magnet 22C, but the attractive force is only in the direction along the optical axis OA, and the optical axis OA. The rotational force centered on is not working.

However, as shown in the lower figure of FIG. 11, when the 2-pole magnet 22C is rotated clockwise, for example, during the runout correction control, the magnetic field strength H1 in the tangential direction around the intersection G1 becomes the tangential direction around the intersection G2. The strength of the magnetic field of H2 is larger than that of H2. In this case, an attractive force due to magnetic force acts between the magnetic body 60C and the two-pole magnet 22C so that the magnetic field strength H1 at the intersection G1 and the magnetic field strength H2 at the intersection G2 are equal. Therefore, a force acts in the direction in which the two-pole magnet 22C rotates counterclockwise with respect to the magnetic body 60C. This force is the restoring force that tries to return to the initial position. The restoring force also works when the 2-pole magnet 22C rotates counterclockwise. This restoring force suppresses the rotation of the 2-pole magnet 22C. Since the same force acts on the four two-pole magnets 22, the rotation of the holding portion 21 is suppressed.

Similar restoring forces are generated not only by the tangential magnetic field, but also by the radial magnetic field. Since this mechanism is the same as the mechanism by the magnetic field in the circumferential direction, the description thereof is omitted.

In the present embodiment, four pairs of voice coil motors, which are a pair of the two-pole magnet 22 and the coil 40, are arranged in the holding portion 21 at predetermined intervals. By arranging the pair of the two-pole magnet 22 and the coil 40 at the positions corresponding to the optical axis OA in this way, the rotation suppressing force is located at the position corresponding to the optical axis OA on the circumference of the lens 20. Since it occurs evenly, stable rotation suppression can be performed. The position corresponding to the optical axis OA is, for example, a position that is axisymmetric or substantially axially symmetric with respect to the optical axis OA.

As described above, the two-pole magnet 22 and the magnetic body 60 are attracted to each other by the magnetic force of the two-pole magnet 22. Since the magnetic body 60 is fixed to the base portion 50, a force acts on the two-pole magnet 22 in a direction of being attracted toward the magnetic body 60. This force is a force that urges the holding portion 21 toward the balls 30A to 30C. This urging force always works even when the holding portion 21 is in the initial position and during the runout correction. This urging force is useful for stably driving the holding portion 21 on the balls 30A to 30C even if the direction of the correction lens unit 1 changes. The urging of the lens 20 by the two-pole magnet 22 and the magnetic body 60 can save space as compared with the urging by the spring of the prior art.

In the correction lens unit 1 having the above configuration, the magnetic body 60 fixed at a position overlapping the two-pole magnet 22 in the direction along the optical axis OA exerts a restoring force on the rotation of the holding portion 21. The rotation of the holding portion 21 can be suppressed. Therefore, when driving the lens 20 for vibration correction, it is possible to suppress erroneous determination of the position of the lens 20 based on the detection signal of the Hall element 14.

Here, the "misjudgment of position" is not a malfunction of the Hall element 14. The control program for runout correction is made on the premise that the holding unit 21 does not rotate. Therefore, when the holding unit 21 rotates, the position of the holding unit 21 calculated by the control program based on the detection signal of the Hall element 14 and the position where the holding unit 21, that is, the lens 20 actually exists are deviated from each other. This is called "misjudgment of position".

Further, according to the correction lens unit 1 having the above configuration, since the spring used in the prior art is not used to stabilize the position of the holding portion 21, there is an effect that the space can be saved and the size can be reduced. .. Therefore, it is possible to provide a lens driving device that is compact and can suppress the rotation of the lens holding portion.

(Embodiment 2)
Next, the second embodiment will be described with reference to the drawings. The parts having the same configuration as the correction lens unit 1 according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As an example, as shown in FIG. 12, in the correction lens unit 2 according to the second embodiment, each of the magnetic bodies 60A to 60D has a two-pole magnet 22 in a direction along the boundary line MB of the magnetic poles of the two-pole magnet 22. It is located at a position deviated from the center. With this configuration, the FPC 12 including the Hall element 14 is arranged in the base portion 50. Therefore, the sensor support portion 10 is not provided.

The deviation direction of the magnetic body 60 from the center of the two-pole magnet 22 is, as shown in FIG. 13, right from the center of the two-pole magnet 22 along the boundary line MB. It is displaced by a predetermined distance around it. Further, the magnetic body 60B and the magnetic body 60D are displaced counterclockwise by a predetermined distance from the center of the two-pole magnet 22 along the boundary line MB. In this way, by deviating half of each of the four magnetic bodies 60 by predetermined distances in different directions along the boundary line MB, at four locations between the two-pole magnet 22 and the magnetic body 60. The generated suction moment can be offset. Therefore, the holding portion 21 is stabilized at the initial position, and in the case of shake correction, it is possible to suppress the rotation of the holding portion 21 which causes an erroneous determination of the position of the lens 20.

As shown in FIG. 14, since the magnetic body 60B is arranged in the base portion 50 at a position deviated from the center of the two-pole magnet 22B, the Hall element 14A is arranged between the coil 40B and the base portion 50. Can be done. The Hall element 14A is arranged at a position corresponding to the air core portion of the coil 40B. Since the magnetic body 60B is located at a position deviated from the center of the 2-pole magnet 22B, the Hall element 14A can accurately detect the change in the magnetic field of the 2-pole magnet 22B. Similarly, the Hall element 14B can be arranged between the base portion 50 facing the center of the two-pole magnet 22C and the coil 40C (not shown). Therefore, the FPC 12 including the Hall element 14 can be arranged between the coil 40 and the base portion 50.

Since the electrical wiring to the coil 40 is wired from the side of the base portion 50, the electrical wiring to the coil 40 can also be included in the FPC 12, and the wiring design becomes easy and compact. As described above, in the present embodiment, the degree of freedom in the layout design of the Hall element 14, the wiring, and the like can be improved.

(Embodiment 3)
Next, the third embodiment will be described with reference to the drawings. The parts having the same configuration as the correction lens unit 1 according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As an example, as shown in FIG. 15, in the correction lens unit 3 according to the third embodiment, two magnetic bodies 60 are arranged with respect to one two-pole magnet 22. Specifically, as shown in FIG. 16, magnetic materials 60A and 60E are arranged with respect to the two-pole magnet 22A. Similarly, the magnetic bodies 60B and 60F are arranged with respect to the 2-pole magnet 22B, the magnetic bodies 60C and 60G are arranged with respect to the 2-pole magnet 22C, and the magnetic bodies 60D and 60H are arranged with respect to the 2-pole magnet 22D. ing.

The two magnetic bodies 60 arranged corresponding to one two-pole magnet 22 are located along the boundary line MB of the magnetic poles of the two-pole magnet 22 with the center of the two-pole magnet 22 interposed therebetween, that is, from the center. They are arranged one by one at positions separated by a predetermined distance. By arranging the magnetic body 60 in this way, the suction moment generated between the two-pole magnet 22 and the magnetic body 60 can be canceled out. Therefore, the holding portion 21 is stabilized at the initial position, and in the case of shake correction, the rotation of the holding portion 21, which causes an erroneous determination of the position of the lens 20, is suppressed more strongly than in the case where the magnetic material 60 is four. can do.

(Embodiment 4)
Next, the correction lens unit 4 according to the fourth embodiment will be described with reference to FIG. The correction lens unit 4 has one magnetic body 60A corresponding to the two-pole magnet 22A. No magnetic material corresponding to the other two-pole magnets 22B to 22D is arranged.

When there is only one magnetic material 60A for the four two-pole magnets 22A to 22D, the attractive force between the magnetic material and the two-pole magnet works only in one place when the holding portion 21 rotates. , The suction power cannot be balanced. Therefore, a spring force corresponding to an attractive force is applied between the position where the magnetic body 60A is arranged and the position facing the radial direction, that is, between the 2-pole magnet 22C (or the holding portion 21 near the 2-pole magnet 22C) and the base portion 50. (Not shown). As the spring, the spring used in the runout correction mechanism of the prior art can be used. According to the configuration of the correction lens unit 4, it is possible to suppress the rotation of the holding portion 21 which causes an erroneous determination of the position of the lens 20 in the case of the shake correction, as in the first embodiment.

(Embodiment 5)
Next, the correction lens unit 5 according to the fifth embodiment will be described with reference to FIG. The correction lens unit 5 has a magnetic body 60A corresponding to the 2-pole magnet 22A and a magnetic body 60C corresponding to the 2-pole magnet 22C. The magnetic body 60A and the magnetic body 60C are arranged in the central portion of the two-pole magnet 22A and the two-pole magnet 22C, respectively. The magnetic material corresponding to the other two-pole magnets 22B and 22D is not arranged.

According to the correction lens unit 5, even when the holding portion 21 is rotated, the attractive force between the two-pole magnet 22A and the magnetic body 60A and the attractive force between the two-pole magnet 22C and the magnetic body 60C are balanced. It is not necessary to balance by the spring as in 4. According to the configuration of the correction lens unit 5, it is possible to suppress the rotation of the holding portion 21 which causes an erroneous determination of the position of the lens 20 in the case of the shake correction, as in the first embodiment.

(Embodiment 6)
It is preferable that the two-pole magnets 22A to 22D face each other in the radial direction, but they do not necessarily have to be arranged at equal intervals. When the two-pole magnets 22A to 22D are not arranged at equal intervals, the drive directions of the voice coil motors are not orthogonal to each other. That is, the drive direction of the two sets of voice coil motors composed of the two-pole magnets 22A and 22C and the coils 40A and 40C, and the two sets of voice coil motors composed of the two-pole magnets 22B and 22D and the coils 40B and 40D. The drive directions are not orthogonal. In that case, the drive direction and the drive amount required for the runout correction are decomposed into the drive amounts in the drive directions of the two sets of voice coil motors, and the calculation is performed to control each voice coil motor.

Further, in the above embodiment, four voice coil motors including the two-pole magnet 22 and the coil 40 are provided. However, there may be at least two. When there are two voice coil motors, the two voice coil motors are arranged at an angular interval of 90 ° so as to drive the holding portion 21 in the directions orthogonal to each other. For example, in FIG. 2, the configuration has only the two-pole magnets 22B and 22C and the coils 40B and 40C. A voice coil motor consisting of a 2-pole magnet 22B and a coil 40B drives the holding portion 21 in the X-axis direction, and a voice coil motor consisting of a 2-pole magnet 22C and a coil 40C drives the holding portion 21 in the Y-axis direction. Can be done.

(Embodiment 7)
In the above embodiments 1 to 6, the coil 40 is fixed to the base portion 50. On the other hand, the 2-pole magnet 22 is fixed to the holding portion 21 and moves relative to the base portion 50 together with the lens 20. However, the arrangement of the coil 40 and the two-pole magnet 22 may be exchanged. That is, the 2-pole magnet 22 may be fixed to the base portion 50, and the coil 40 may be fixed to the holding portion 21.

As an example, as shown in FIG. 19, in the correction lens unit 6 according to the seventh embodiment, the coils 40A to 40D are fixed to the holding portion 21. The coils 40A to 40D are fixed at positions corresponding to the periphery of the lens 20 at predetermined intervals. Magnetic materials 60A to 60D are fixed to the coils 40A to 40D, respectively. The magnetic body 60A is displaced in the positive X direction from the center of the coil 40A, and the magnetic body 60C is displaced in the negative X direction by the same distance from the center of the coil 40C. ing. Further, the magnetic body 60D is displaced in the positive Y direction from the center of the coil 40D, and the magnetic body 60B is displaced in the negative Y direction by the same distance from the center of the coil 40B. Have been placed. The reason for deviating the magnetic body 60 is to prevent it from overlapping the Hall element 14 in the optical axis OA direction. Further, the FPS 12 provided with the Hall elements 14A and 14B is fixed to the subject side of the holding portion 21. Therefore, the sensor support portion 10 is not provided. On the other hand, the two-pole magnets 22A to 22D are fixed to the bottom surface 56 of the base portion 50. The two-pole magnets 22A to 22D are arranged so as to correspond to each of the four coils 40A to 40D so that the N pole and the S pole are adjacent to each other in the direction intersecting the optical axis OA of the lens 20. In the present embodiment, the north pole and the south pole of the two-pole magnet 22 are adjacent to each other in a direction orthogonal to the optical axis OA of the lens 20.

The arrangement relationship between the coils 40A to 40D and the two-pole magnets 22A to 22D along the optical axis OA, and the arrangement relationship between the magnetic materials 60A to 60D and the two-pole magnets 22A to 22D along the optical axis OA are It is the same as the arrangement relationship described in the first embodiment. Further, the arrangement relationship between the Hall elements 14A and 14B and the two-pole magnets 22B and 22C is the same as the arrangement relationship described in the first embodiment.

According to the above configuration, the two-pole magnet based on the detection signal of the Hall element 14 in the case of runout correction, as in the first embodiment, due to the attractive force between the magnetic bodies 60A to 60D and the two-pole magnets 22A to 22D. It is possible to suppress the rotation of the holding portion 21, which causes an erroneous determination of the position of the 22. The mechanism by which the rotation of the holding portion 21 is suppressed is the same as the mechanism described in the first embodiment.

In the seventh embodiment, the magnetic bodies 60A to 60D are arranged in the coils 40A to 40D. However, the magnetic bodies 60A to 60D may be arranged directly on the holding portion 21 (not shown). Further, although the Hall elements 14A and 14B are fixed to the holding portion 21 together with the FPC 12, the Hall elements 14A and 14B may be directly arranged on the holding portion 21 (not shown).

Further, the same configuration as that described in the second to sixth embodiments may be applied to the seventh embodiment. Specifically, the magnetic body 60 may be arranged at a position deviated from the center of the two-pole magnet 22 in the direction along the boundary line MB of the magnetic poles of the two-pole magnet 22. The arrangement relationship between the magnetic body 60 and the two-pole magnet 22 can be, for example, the arrangement shown in FIG.

Further, two magnetic bodies 60 may be arranged for one two-pole magnet 22. The arrangement relationship between the magnetic body 60 and the two-pole magnet 22 can be, for example, the arrangement shown in FIG.

Further, for example, as shown in FIG. 17, the magnetic body 60A corresponding only to the 2-pole magnet 22A among the four 2-pole magnets 22 may be provided. In this case, as in the fourth embodiment, the position where the magnetic body 60A is arranged and the position facing the radial direction, that is, between the coil 40C and the base portion 50, between the two-pole magnet 22A and the magnetic body 60A. A spring having a spring force corresponding to the suction force is arranged (not shown).

Further, for example, as shown in FIG. 18, of the four 2-pole magnets 22, the magnetic body 60A and the magnetic body 60C corresponding to the 2-pole magnet 22A and the 2-pole magnet 22C may be provided, respectively.

Further, the voice coil motors of the two-pole magnet 22 and the coil 40 do not necessarily have to be arranged at equal intervals. Although the drive directions of the two sets of voice coil motors are not orthogonal, the calculation is performed to decompose the drive direction and drive amount required for runout correction into the drive amounts of the drive directions of the two sets of voice coil motors, and each voice coil motor is used. You just have to control it.

With the above configuration, it is possible to suppress the rotation of the holding portion 21 which causes an erroneous determination of the position of the lens 20 in the case of the shake correction.

In the above embodiment, the Hall element 14 that detects the magnetic field of the two-pole magnet is used as the position sensor, but the present invention is not limited to this. For example, another magnet for position detection may be arranged in the base portion, and the movement amount may be detected by a Hall element provided in the holding portion. The arrangement of the Hall element and the magnet for position detection can be appropriately set in consideration of the arrangement with other members. Further, instead of the position sensor that detects magnetism, a known position sensor using another principle may be used.

In the above embodiment, the lens driving device of the present disclosure has been described as a correction lens unit used for an image pickup device such as a digital camera, but the image pickup device is not limited to the digital camera. Further, the lens driving device can be applied as a component of a lens unit used in an image pickup device, and can be applied not only to a dedicated image pickup device but also to various devices including an image pickup device.

As used herein, "A and / or B" is synonymous with "at least one of A and B." That is, "A and / or B" means that it may be only A, it may be only B, or it may be a combination of A and B. Further, in the present specification, when three or more matters are connected and expressed by "and / or", the same concept as "A and / or B" is applied.

All documents, patent applications and technical standards described herein are to the same extent as if it were specifically and individually stated that the individual documents, patent applications and technical standards are incorporated by reference. Incorporated by reference in the book.

1,2,3,4,5,6 Correction lens unit 10 Sensor support 12 FPC
14, 14A, 14B Hall element 20 Lens 21 Holding part 22, 22A, 22B, 22C, 22D 2-pole magnet 24, 24A, 24B, 24C, 24D Magnet support part 26, 26A, 26B, 26C Ball contact part 27, 27A , 27B, 27C Holding part Support surface 30, 30A, 30B, 30C Ball 40, 40A, 40B, 40C, 40D Coil 50 Base part 52, 52A, 52B, 52C, 52D Side wall part 54, 54A, 54B, 54C Ball accommodating part 56 Bottom surface 60, 60A, 60B, 60C, 60D, 60E, 60F, 60G, 60H Magnetic material 62, 62A, 62B, 62C, 62D Recess

Claims (8)

A holding part that holds the lens for shake correction,
A base portion that displaceably supports the holding portion along a surface intersecting the optical axis of the lens, and a base portion.
At least two two-pole magnets, each of which is fixed at a predetermined position at a position corresponding to the periphery of the lens in the holding portion and has different magnetic poles adjacent to each other in a direction intersecting the optical axis.
With respect to each of the at least two two-pole magnets, the axis of each coil is aligned with the optical axis direction, and at least two coils arranged in the base portion.
One by one is arranged at a position deviated from the center of the two-pole magnet in a direction along the boundary line of the magnetic poles of the two-pole magnet, and half of the magnetic material is the same as the other half. A magnetic material placed at a position deviated away from the center of the two-pole magnet in a different direction, and
A Hall element arranged at the base portion at a position corresponding to the midpoint of the boundary line of the magnetic poles of the two-pole magnet and the direction along the optical axis.
Lens drive device including. A holding part that holds the lens for shake correction,
A base portion that displaceably supports the holding portion along a surface intersecting the optical axis, and a base portion.
At least two coils in which the axes of the respective coils are fixed at predetermined intervals at positions corresponding to the periphery of the lens in the holding portion along the optical axis direction.
At least two two-pole magnets fixed to the base portion, each of which has different magnetic poles arranged adjacent to each other in a direction intersecting the optical axis, corresponding to each of the at least two coils.
One by one is arranged at a position deviated from the center of the two-pole magnet in a direction along the boundary line of the magnetic poles of the two-pole magnet, and half of the magnetic material is the same as the other half. A magnetic material placed at a position deviated away from the center of the two-pole magnet in a different direction, and
A Hall element arranged in the holding portion or the coil at a position corresponding to the midpoint of the boundary line of the magnetic poles of the two-pole magnet and the direction along the optical axis.
Lens drive device including. (Delete) The lens driving device according to claim 1 or 2, wherein the magnetic material is arranged one by one at corresponding positions across the center of the two-pole magnet along the boundary line. In any one of claims 1, 2, and 4, the pair of the two-pole magnet and the coil corresponding to the two-pole magnet is arranged at a position corresponding to the optical axis. The lens drive device described. The coil has a length in the tangential direction with respect to the circumference of the lens longer than the length in the radial direction of the lens, and the two-pole magnet has a flat rectangular shape long in the tangential direction with respect to the circumference of the lens. Item 2. The lens driving device according to any one of claims 4 and 5. The lens driving device according to any one of claims 1, 2, and 4 to 6, which has at least three support portions that support the holding portion with respect to the base portion. The lens driving device according to claim 7, wherein the support portion is a rolling element.

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