CN110068907B

CN110068907B - Lens driving device

Info

Publication number: CN110068907B
Application number: CN201810062176.8A
Authority: CN
Inventors: 松岛俊治; 潮田丰; 藤井健
Original assignee: Ruien Photoelectric Co ltd
Current assignee: Ruien photoelectric Co., Ltd
Priority date: 2018-01-23
Filing date: 2018-01-23
Publication date: 2021-06-15
Anticipated expiration: 2038-01-23
Also published as: CN110068907A

Abstract

The lens driving device of the invention can stably drive a lens, and comprises a lens barrel for mounting the lens; a housing accommodating the lens barrel; a 1 st voice coil motor that moves the lens barrel in an optical axis direction with respect to the housing; a 1 st guide portion that guides movement of the lens barrel with respect to the housing; a support cover for supporting the housing on one end face side of the lens; a 2 nd voice coil motor that moves the housing relative to the support cover in a vertical direction opposite to the optical axis direction; a 2 nd guide portion disposed between the housing and the support cover, for guiding the housing to move relative to the bottom cover; and a connecting member connecting the housing and the support cover. Therefore, the connection member is configured to be connected while maintaining a certain distance between the housing and the support cover.

Description

Lens driving device

Technical Field

The present invention relates to a lens driving device, and more particularly, to a lens driving device having an auto-focusing function and a shake correction function.

Background

Recent information processing terminals such as smartphones and tablet terminals are equipped with small-sized camera modules for capturing images. Such an image pickup module includes a lens driving device having an auto-focus function of performing auto-focus when an object is picked up and a shake correction function of optically correcting hand shake occurring during image pickup to reduce image blur.

For example, as shown in patent document 1, the autofocus function of the lens driving device is realized by a Voice Coil Motor (Voice Coil Motor) including a magnet and a Coil. The lens is reciprocated in the optical axis direction by the driving force of the voice coil motor. Accordingly, the lens driving device supports the reciprocal movement along the optical axis direction of the lens, which realizes the auto-focusing function, by the guide balls disposed around the lens driving device.

Patent document 1 Japanese laid-open patent publication No. 2015-

Disclosure of Invention

Here, in the lens driving device having the above-described auto-focusing function, when moving in the optical axis direction, it is necessary to stably reciprocate the lens. That is, it is necessary to suppress the occurrence of a shake of the optical axis of the lens with movement. Therefore, it is desirable to improve the stability of the lens during the reciprocating movement. Further, since the lens driving device also has a shake correction function, it is also desired to improve the stability at the time of lens driving in cooperation with the structure of the shake correction function.

A lens driving device as one embodiment of the present invention includes a lens barrel to which a lens is attached; a housing surrounding the lens barrel, accommodating the lens barrel; a 1 st voice coil motor that moves the lens barrel relative to the housing in an optical axis direction of the lens; and a 1 st guide portion which guides the lens barrel to move relative to the housing, wherein the 1 st voice coil motor is provided with a magnet at one end in the housing or the lens barrel, and a coil and a yoke at the other end, the yoke is configured to press the lens barrel to the 1 st guide portion by receiving a magnetic force attracted by the magnet, and the lens driving device further includes a support cover which supports the housing at one end surface side of the lens; a 2 nd voice coil motor that moves the housing relative to the support cover in a vertical direction opposite to an optical axis direction of the lens; a 2 nd guide portion which is disposed between the housing and the support cover, abuts against the housing and the support cover, and guides the movement of the housing relative to the support cover; and a connection member connecting the housing and the support cover, wherein the 2 nd voice coil motor has a magnet at one end in the housing or the support cover, and a coil and a yoke at the other end, and the connection member is configured to be connected to the housing and the support cover with a predetermined distance therebetween.

In the lens driving device, the connecting member is configured to apply a force to attract the housing and the support cover to each other via the 2 nd guide portion.

In the lens driving device, the connecting member is configured to have flexibility in a direction perpendicular to an optical axis direction of the lens.

In the lens driving device, the connecting member is formed of a tension spring that applies a force to attract the housing and the support cover to each other.

In the lens driving device, the 2 nd guide portion may be formed of a plurality of spherical bodies, and the plurality of spherical bodies may be disposed at positions predetermined with respect to the support cover and may rotate at the disposed positions.

In the lens driving device, the 2 nd voice coil motor may be 2 voice coil motors, and the 2 nd voice coil motor may move the housing in two linear directions orthogonal to each other on a vertical surface facing the optical axis direction of the lens.

In the lens driving device, the 1 st voice coil motors are respectively arranged at 2 adjacent positions in the lens barrel having a substantially rectangular shape, the 1 st guide portion is arranged at a position intermediate between the two 1 st voice coil motors, and the yoke is arranged to press the lens barrel toward the 1 st guide portion by a resultant force of magnetic forces generated by the yokes of the two 1 st voice coil motors.

In the lens driving device, the 1 st guide portion includes a main guide portion disposed in the vicinity of an angle between two adjacent sides of the substantially rectangular lens barrel in which the two 1 st voice coil motors are disposed, and a sub guide portion disposed in the vicinity of the other corner on a diagonal line opposite to the corner of the substantially rectangular lens barrel in which the main guide portion is disposed, and the two 1 st voice coil motors are configured to have different magnetic forces to be attracted to the magnets, and the sub guide portion supports the pressing force of the lens barrel that is biased to rotate about the main guide portion as a fulcrum by a resultant force of the magnetic forces generated by the yokes of the two 1 st voice coil motors.

In the lens driving device, 2 voice coil motors for moving the housing in 2 linear directions orthogonal to each other on a vertical surface facing the optical axis direction of the lens are disposed as the 2 nd voice coil motor in the vicinity of the other 2 sides different from the positions of the two adjacent sides of the lens barrel in which the 1 st voice coil motor is disposed.

In addition, the invention also provides an image pickup module with the lens driving device.

Effects of the invention

According to the lens driving device of the present invention, the lens barrel is pushed toward the 1 st guide portion to be guided to move in the optical axis direction. In addition, the housing accommodating the lens barrel is kept at a certain distance from the support cover while the movement in the perpendicular direction with respect to the optical axis direction can be guided by the 2 nd guide portion. As a result, the stability of lens movement in the auto-focus function and the shake correction function can be improved.

Drawings

Fig. 1 is a diagram showing a configuration of an image pickup module according to embodiment 1 of the present invention.

Fig. 2 is a diagram showing a structure of a lens barrel constituting an image pickup module.

Fig. 3 is a diagram showing a structure of a housing constituting the camera module.

Fig. 4 is a diagram showing the structures of a cover and a bottom cover constituting the image pickup module.

Fig. 5 is a diagram illustrating a structure of an FPC constituting the camera module.

Fig. 6 is a diagram showing a magnet and coil structure constituting the imaging module.

Fig. 7 is a diagram showing a yoke structure constituting the image pickup module.

Fig. 8 is a diagram showing a camera module combination state.

Fig. 9 is a diagram illustrating an operation of the camera module.

Fig. 10 is a diagram illustrating an operation of the camera module.

Description of the reference numerals

1, a camera module; 2, a lens; 3a lens barrel; 31 the 1 st guide ball holding part; 32 nd 2 nd guide ball holding part; 33,34 recesses; 4, a shell; 41 the 1 st guide ball support portion; 42 nd 2 nd guide ball support portion; 43,44, 1 st recess; 45,46, 2 nd recess; 47 a cut-out portion; 48 support the guide ball bearings; 5, covering; 6, a bottom cover; 61 a traction part; 62 an accommodating part; 71a,71b,74a,74 b; 72a,72b,75a,75b coil; 73a,73b yokes; 76 a main guide ball; 77 auxiliary guide balls; 78 support the guide ball; 79 connecting a spring; 8 FPC.

Detailed Description

< embodiment 1>

Embodiment 1 of the present invention is explained with reference to fig. 1 to 10. Fig. 1 is a diagram showing the structure of the camera module 1. Fig. 2 to 7 are diagrams illustrating parts constituting the camera module. Fig. 8 is a diagram showing a camera module combination state. Fig. 9 to 10 are diagrams illustrating the operation of the camera module.

The camera module 1 according to the present invention is mounted on an information processing terminal such as a smartphone or a tablet terminal, for example, and is used to capture an image. However, the camera module 1 of the present invention is not necessarily limited to being mounted on an information processing terminal, and may be mounted on other electronic devices or various devices.

The imaging module 1 of the present invention includes a lens driving device having an auto-focus function for automatically focusing when an object is imaged and a shake correction function for optically correcting hand shake occurring during imaging to reduce image blur. Hereinafter, a configuration of a lens driving device that realizes an auto-focus function and a shake correction function will be mainly described. Further, the lens driving device may have a function other than the functions illustrated in the present embodiment.

[ Structure ]

First, the overall configuration of the image pickup module 1 will be described with reference to fig. 1. Fig. 1 is a top view and side views of the camera module 1. In the drawings of the present invention, some of the structures are illustrated through or omitted in order to make the structures more clear.

First, the camera module 1 includes a cover 5 covering an upper portion and a bottom cover 6 covering a lower portion. Fig. 1 is a view through the top and side surfaces of the cover 5. Therefore, the interior of the cover 5 and the bottom cover 6 (support cover) of the camera module 1 includes the lens barrel 3 to which the lens 2 is attached and the housing 4 surrounding the lens barrel 3 for accommodating the lens barrel 3. Further, the camera module 1 includes 21 st voice coil motors 71 to 73 and 21

st guide portions

76, 77, wherein the 1 st voice coil motors 71 to 73 move the lens barrel 3 relative to the housing 4 in the optical axis direction of the lens 2, and the 1

st guide portions

76, 77 guide the movement of the lens barrel 3 relative to the housing 4. The autofocus function of the lens 2 is realized mainly by the 1 st voice coil motors 71 to 73 and the 1

st guide portions

76 and 77.

The housing 4 is supported by the bottom cover 6 on the lower surface side (one end surface side) of the lens 2, and the image pickup module 1 includes 2 nd voice coil motors 74 and 75, and the 2 nd voice coil motors 74 and 75 move the housing 4 relative to the bottom cover 6 in the vertical direction opposite to the optical axis direction of the lens 2. The camera module 1 is disposed between the housing 4 and the bottom cover 6, and includes a 2 nd guide portion 78 for guiding the movement of the housing 4 with respect to the 2 nd voice coil motors 74 and 75, and a connection spring 79 (connection member) for connecting the housing 4 and the bottom cover 6. Also, the shake correction function of the lens 2 is mainly realized by this structure.

Further, the camera module 1 includes an FPC (Flexible Printed Circuits) 8 and other structures. The following describes each structure.

The structure of the lens barrel 3 will be described with reference to fig. 2. Fig. 2 is a top view and side views of the lens barrel 3. The lens barrel 3 has a substantially rectangular outer shape. The lens barrel 3 is formed at the center thereof with a lens accommodating hole for accommodating the lens 2.

Further,

concave portions

33 and 34 recessed inward are formed on the side surface of the lens barrel 3. Specifically, the recessed

portions

33 and 34 are formed at the corner portions formed by the intersections of 2 substantially rectangular adjacent sides of the side surface of the lens barrel 3. Thus,

magnets

71a and 71b constituting the 1 st voice coil motor are disposed in the

recesses

33 and 34, respectively. The 1 st voice coil motor moves the lens barrel 3 in the optical axis direction of the lens 2, and is composed of the

magnets

71a and 71b (magnets) described above, and coils 72a and 72b and

yokes

73a and 73b disposed on the housing 4 with respect to the

magnets

71a and 71b described below. Thus, the 1 st voice coil motor for realizing the automatic focusing function is arranged at the positions of the adjacent 2 sides of the rectangle.

Further, a 1 st guide ball holding portion 31 is formed at a position between adjacent 2 sides of the substantially rectangular lens barrel 3 where the 21 st voice coil motors are arranged. The 1 st guide ball holding portion 31 is formed by a groove along the optical axis direction of the lens 2, which is open to the outside on a diagonal line passing through the formed angular position. Therefore, the 1 st guide ball holding portion 31 rotatably holds the main guide ball 76 (main guide portion) of the spherical body as a part of the 1 st guide portion. The main guide ball 76 is pressed and supported by a 1 st guide ball support portion 41 formed on an inner surface of the housing 4 described below. Thereby, the main guide ball 76 rotates in the groove serving as the 1 st guide ball holding portion 31, and the lens barrel 3 is guided by the main guide ball 76 and moves in the optical axis direction of the lens 2. In fig. 2, although 2 main guide balls 76 are held in the grooves of the guide ball holding portion 31, the number of the main guide balls 76 may be several.

In the lens barrel 3, the 2 nd guide ball holding portion 32 is formed at another diagonal corner position opposite to the corner position at which the 1 st guide ball holding portion 31 is formed. The 2 nd guide ball holding portion 32 is formed of a substantially spherical hole that opens in a direction orthogonal to a diagonal line passing through the formed angular position. Therefore, the 2 nd guide ball holding portion 32 rotatably holds the sub guide ball 77 (sub guide portion) of the spherical body which is a part of the 1 st guide portion. The sub guide ball 77 is pressed and supported by a 2 nd guide ball support portion 42 formed on the inner surface of the housing 4 described below. Thereby, the sub guide ball 77 rotates in the hole as the 2 nd guide ball holding portion 32, and the lens barrel 3 moves along the optical axis direction of the lens 2.

In addition, the lens barrel 3 may further include a position detection structure that detects a position of the lens barrel 3 in the optical axis direction of the lens 2. The position detection structure may be constituted by, for example, a magnet disposed in the lens barrel 3 and a hall element for detecting the intensity of the magnetic field disposed in the housing 4 described below.

Next, the structure of the housing 4 will be described with reference to fig. 3. Fig. 3 shows a top view, side views, and a bottom view of the housing 4.

The housing 4 is a cylindrical member having a substantially rectangular end face and is formed by 4-face side walls. Therefore, the lens barrel 3 on which the above-described lens 2 is mounted is accommodated in the housing 4, and the components constituting the 1 st voice coil motor are mounted. Further, the housing 4 is also mounted with parts constituting a 2 nd voice coil motor described below.

Specifically, a concave 1 st guide ball support portion 41 for receiving the main guide ball 76 is formed on the inner surface of the housing 4 at 1 angular position, that is, at an angular position corresponding to the 1 st guide ball holding portion 31 formed in the lens barrel 3 accommodated therein. Further, a concave 2 nd guide ball support portion 42 that receives the sub guide ball 77 is formed on the inner surface of the other angular position on the diagonal line of the angular position, that is, the inner surface of the angular position corresponding to the 2 nd guide ball holding portion 32 formed in the lens barrel 3 housed therein.

In addition, in both side walls of the housing 4, the 1 st

concave portions

43 and 44 are formed so that the inner surfaces of the side walls themselves are concave. Specifically, in the side wall of the housing 4, the 1 st recesses 43 and 44 are formed at positions facing the

magnets

71a and 71b attached to the lens barrel 3 accommodated therein, respectively.

Coils

72a and 72b and

yokes

73a and 73b, which constitute the 1 st voice coil motor, are disposed in the 1 st recesses 43 and 44, respectively.

Further, the 2 nd

concave portions

45 and 46 recessed upward are formed on the bottom surface of the side wall of the housing 4. Specifically, in the side wall of the housing 4, on the bottom surface of the adjacent two sides of the substantially rectangular shape, the other two sides of the 1 st

concave parts

43 and 44 are not formed, and the 2 nd

concave parts

45 and 46 are formed, respectively. Therefore,

magnets

74a and 74b constituting the 2 nd voice coil motor are disposed in the 2 nd recesses 45 and 46, respectively. The 2 nd voice coil motor moves the housing 4 accommodating the lens barrel 3 along a plane perpendicular to the optical axis direction of the lens 2, and is composed of the

magnets

74a and 74b (magnets) and coils 75a and 75b disposed on the bottom cover 6 described below. At this time, the first 2 nd voice coil motor, which is constituted by the magnet indicated by 74b in fig. 1, moves in one linear direction (X-axis direction) on a plane perpendicular to the optical axis direction of the lens 2. Further, the second 2 nd voice coil motor, which is constituted by the magnet indicated by 74a, moves in the other linear direction (Y-axis direction) orthogonal to the one linear direction on the optical axis direction vertical plane of the lens 2.

In addition, the bottom surfaces of the 4 corners of the housing 4 are formed with cut-outs 47 cut out toward the upper surface side, respectively. The 4 cut-outs 47 respectively accommodate therein a connecting spring 79. Thus, the inner surface of the ceiling of each cutout 47 is configured as one end pulled by the connection spring 79.

The bottom surface of the housing 4 is formed in a concave shape, and support guide ball receiving portions 48 for receiving support guide balls 78 described below are formed at 3 places.

The housing 4 may include a part of a position detection structure for detecting a position of the lens barrel 3 along the optical axis direction of the lens 2. The position detecting structure is constituted by, for example, a magnet and a hall element for detecting the magnetic field intensity, and the hall element may be disposed in the housing 4 for detecting the magnetic field intensity of the magnet disposed in the lens barrel 3. The housing 4 may include a position detection structure for detecting a position of the housing 4 in a direction perpendicular to the optical axis direction of the lens 2, that is, a position of the housing 4 facing the bottom cover 6. For example, a magnet may be provided on the housing 4 and a hall element may be provided on the bottom cover 6.

Next, the structure of the cover 5 and the bottom cover 6 will be described with reference to fig. 4. Fig. 4 (a) and 4 (b) show a top view and a side view of the cover 5 and the bottom cover 6, respectively.

The upper surface of the cover 5 is formed in a substantially rectangular shape, and is formed in a box shape surrounded on four sides by side walls. Therefore, the housing 4 and the like are covered from above. Further, a hole having a size corresponding to the lens 2 is formed at the center of the upper surface of the cover 5.

The bottom cover 6 is a plate-like member formed in a substantially rectangular shape, and covers the bottom surface of the housing 4 and the like covered with the cover 5. Therefore, a hole having a size corresponding to the lens 2 is formed at the center of the bottom cover 6. Further, pulling portions 61 for pulling the other ends of the connecting springs 79 are formed at 4 corners of the bottom cover 6. Further, 3 accommodating portions 62 are formed on the bottom cover 6. Each receiving portion 62 receives a support guide ball 78 as a spherical body so as to be rotatable, and determines the position of the support guide ball 78. The support guide ball 78 is held between the support guide ball retainer 48 formed in the housing 4 and the bottom cover 6, and has a function of guiding the housing 4 to move relative to the bottom cover 6 on a vertical plane opposite to the optical axis direction of the lens 2. The number of the receiving portions 62 is not limited to 3, and the number of the support guide balls 78 is not limited to 3.

Next, the structure of the FPC described above will be described with reference to fig. 5. Fig. 5 is a top view and a side view of the FPC 8.

The FPC8 is in the form of a thin plate and has an outer shape substantially the same as that of the bottom cover 6. Therefore, the cover member can be assembled substantially integrally with the bottom cover 6 and handled as the same member as the bottom cover 6. Therefore, coils 75a and 75b constituting the 2 nd voice coil motor are provided on the adjacent 2 sides of the FPC8, respectively. Specifically, the

coils

75a and 75b are provided at positions facing the

magnets

74a and 74b of the 2 nd voice coil motor provided in the housing 4.

Next, the components constituting the 1 st and 2 nd voice coil motors will be described with reference to fig. 6 to 7. First, the 1 st voice coil motor is composed of

magnets

71a and 71b disposed in the lens barrel 3, and coils 72a and 72b and

yokes

73a and 73b provided in the housing 4.

As shown in the front view and the plan view of fig. 6 (a), the

magnets

71a and 71b constituting the 1 st voice coil motor are formed in a rectangular shape having a predetermined thickness. As shown in the front view and the plan view of fig. 6 (b), coils 72a and 72b constituting the 1 st voice coil motor have substantially the same outer shape as

magnets

71a and 71b, and are formed in an elliptical ring shape.

As shown in the front and plan views of fig. 8 (a) and (b), the

yokes

73a and 73b constituting the 1 st voice coil motor are formed in T-shaped thin plate shapes, and have some shape differences from each other. The 1 st yoke 73a shown in fig. 8 (a) is arranged to correspond to the magnet 71a and the coil 72a, and the 2 nd yoke 73b shown in fig. 8 (b) is arranged to correspond to the magnet 71b and the coil 72 b. As shown in the drawing, the 2 nd yoke 73b is formed in a shape larger than the 1 st yoke 73 a. Specifically, the thickness of the leg portion in the T-shape in the 2 nd yoke 73b is formed thicker than that of the 1 st yoke 73 a. The

yokes

73a and 73b are arranged with head portions in a T-shape so as to form corner portions at the intersection of adjacent 2 sides of the arranged lens barrel 3.

The 2 nd voice coil motor includes

magnets

74a and 74b disposed on the housing 4 and

coils

75a and 75b provided on the FPC8 serving as the bottom cover 6. As shown in the front view and the plan view of fig. 7 (c), the

magnets

74a and 74b constituting the 2 nd voice coil motor are formed in a rectangular shape having a predetermined thickness. As shown in the front view and the plan view of fig. 7(d), coils 75a and 75b constituting the 2 nd voice coil motor have substantially the same outer shape as

magnets

74a and 74b, and are formed in an elliptical ring shape.

[ Assembly ]

Next, an assembled state of the image pickup module 1 will be described with reference to fig. 8. Fig. 8 shows the image pickup module 1 shown in fig. 1 and 10 as viewed from the right side. The order of the steps in the assembly procedure described below can be adjusted back and forth.

First, the assembly of the housing 4 and the bottom cover 6 will be described with reference to fig. 8 (d). The housing 4 and the bottom cover 6 sandwich the FPC8 therebetween, and are connected by a connection spring 79. Specifically, first, 4 connection springs 79 are respectively arranged in the respective cut-outs 47 formed on the bottom surface sides of the 4 corners of the housing 4, and the ceiling surface end of each cut-out 47 is connected to the pulling portion. Therefore, as shown by the broken line arrows in fig. 8 (d), the other end of each connection spring 79 is inserted into a hole formed in 4 corners of the FPC8, and is connected to the pulling portion 61 formed in 4 corners of the bottom cover 6 by pulling.

At this time, in the bottom cover 6, the support guide balls 78 are disposed in 3 receiving portions 62 formed in the side surface of the housing 4, respectively. Thus, the support guide balls 78 pass through 3 through holes formed in the FPC8, and are connected to the housing 4 by the support guide ball receiving portions 48 formed on the bottom surface of the housing 4. Thereby, the support guide ball 78 is configured in a state of being sandwiched between the housing 4 and the bottom cover 6.

By assembling the housing 4, the FPC8, and the bottom cover 6, a force is applied by the connecting spring 79 to attract the housing 4 and the bottom cover 6 to each other in a state where the guide ball 78 is held and supported. Therefore, as shown in fig. 8 (c), the housing 4 and the bottom cover 6 are integrated, and are connected to each other while always maintaining the distance corresponding to the diameter of the support guide ball 78.

Before the assembly, the

coils

75a and 75b constituting the 2 nd voice coil motor are arranged in the FPC 8. Further,

magnets

74a and 74b constituting the 2 nd voice coil motor are disposed in the 2 nd recesses 45 and 46 formed in the bottom surface of the housing 4 so as to face the

coils

75a and 75b, respectively, whereby the jitter correction function driving can be realized.

Coils

72a and 72b and

yokes

73a and 73b constituting the 1 st voice coil motor are disposed in the 1 st recesses 43 and 44 formed in the side wall of the housing 4, respectively.

Next, the lens barrel 3 shown in fig. 8 (b) is accommodated in the housing 4. At this time, the lens barrel 3 has the lens 2 mounted in the central lens-accommodating hole.

Magnets

71a and 71b constituting the 1 st voice coil motor are disposed in the

recesses

33 and 34 formed in the side surface of the lens barrel 3, respectively. The

magnets

71a and 71b are arranged so as to face the

coils

72a and 72b and the

yokes

73a and 73b of the 1 st voice coil motor arranged in the housing 4 by accommodating the lens barrel 3 in the housing 4, and thus can be driven to realize the auto-focusing function.

In the lens barrel 3, the 1 st guide ball holding portion 31 is attached with the main guide ball 76, and the 2 nd guide ball holding portion 32 is attached with the sub guide ball 77. Therefore, when the lens barrel 3 is accommodated in the housing 4, the main guide ball 76 is supported in contact with the 1 st guide ball support portion 41 of the housing 4, and the sub guide ball 77 is supported in contact with the 2 nd guide ball support portion 42 of the housing 4.

In the above step, a component such as a magnet or a hall element may be attached to configure a position detection structure for detecting the position of the lens barrel 3 in the optical axis direction of the lens 2 and the position of the housing 4 on a vertical surface facing the optical axis direction, or another component not shown may be attached.

Finally, the cover 5 shown in fig. 8 (a) covers the housing 4 from above, and the assembly of the camera module 1 is completed.

[ actions ]

Next, the operation of the camera module 1 will be described with reference to fig. 9 to 10. First, the lens driving of the auto-focus function by the image pickup module 1 will be described with reference to fig. 9 (a) and 10.

As shown in fig. 9 (a), the 1 st voice coil motor for realizing the autofocus function includes a magnet 71a magnetized to N and S poles from above and below the side surface of the lens barrel 3, and a coil 72a and a yoke 73a on the side surface of the housing 4. The yoke 73a is made of, for example, a soft magnetic material (e.g., iron with less impurities) and concentrates the magnetic flux emitted from the magnet 71 a. Although one set of the 1 st voice coil motor is already assembled, only the component configurations of the

reference numerals

71a, 72a, and 73a will be described here.

Therefore, a current flows in the coil 72a, thereby generating a driving force that moves the lens barrel 3 in the optical axis direction of the lens 2. Specifically, when a current flows in the coil 72a, the lens barrel 3 reciprocates along the optical axis direction of the lens 2 (the direction of arrow Y21: the Z-axis direction in FIG. 10) according to the direction of the current and the magnetic flux (refer to arrow Y1) passing from the magnet 71a through the coil 72a, in accordance with the Freim's left-hand rule.

At this time, the lens barrel 3 is mounted with the main guide ball 76 and the sub guide ball 77 abutting on the housing 4, and the lens barrel 3 is pressed against both the

guide balls

76 and 77 by the 2 st voice coil motors 1. Specifically, first, in the 21 st voice coil motors, magnetic forces are generated as indicated by arrows Y11, Y12 in fig. 10, and thus a resultant force Y13 of these is applied to the lens barrel 3. Thereby, the lens barrel 3 is pressed in the diagonal corner direction by the main guide ball 76.

As shown in fig. 10, the magnetic forces Y11 and Y12 acting on the 21 st voice coil motors are different in size. Specifically, as shown in fig. 7, the outer shape of the yoke 73b corresponding to the magnet 71b constituting the 1 st voice coil motor at one end is formed larger than the outer shape of the yoke 73a corresponding to the magnet 71a constituting the 1 st voice coil motor at the other end. Thus, the magnetic force Y12 attracted laterally to the magnet 71b of the first voice coil motor 1 is stronger than the magnetic force Y11 attracted laterally to the magnet 71a of the other end. Accordingly, the lens barrel 3 is urged to rotate about the main guide ball 76 as a fulcrum by the resultant force of the magnetic forces Y11 and Y12 as indicated by an arrow Y14. As a result, the lens barrel 3 is in a state of pressing the sub guide ball 77 in a substantially vertical direction corresponding to the diagonal line, and the sub guide ball 77 is configured to support the pressing.

Therefore, the lens barrel 3 is maintained in contact with the housing 4 by the main guide ball 76 and the sub guide ball 77. Therefore, the movement in the housing 4 corresponding to the optical axis vertical direction is restricted, and the posture thereof is stabilized. As a result, the optical axis can be stabilized, and the autofocus operation can be realized.

In addition, in the 21 st voice coil motors, although magnetic fluxes passing through the

yokes

73a and 73b from the

magnets

71a and 71b are generated, the

yokes

73a and 73b have characteristics of acquiring the magnetic fluxes emitted from the

magnets

71a and 71b as much as possible. Therefore, yokes 73a and 73b function as positions facing the centers of

magnets

71a and 71b, i.e., the boundary between the N-pole and S-pole. Due to this magnetic levitation effect, yokes 73a and 73b are positioned at the boundary between the N-pole and S-pole of

magnets

71a and 71b, and lens barrel 3 connected to

magnets

71a and 71b is levitated. Further, when the lens barrel 3 connected to the

magnets

71a and 71b is moved according to fleming's left-hand rule, the position of the

yokes

73a and 73b is displaced in the vertical direction with respect to the center of the

magnets

71a and 71b, and the magnetic force causes a magnetic spring effect to return to the original position.

As described above, the lens barrel 3 connected to the

magnets

71a and 71b is stabilized at the position where the

yokes

73a and 73b are provided. Therefore, by setting the position of the lens barrel 3 based on the magnetic levitation effect to a predetermined position such as a focus position with a high frequency of use, the driving of the lens barrel 3 by the 1 st voice coil motor can be suppressed, and the power saving can be achieved.

Next, lens driving of the camera module 1 by the shake correction function will be described with reference to fig. 9 (b) and 10.

As shown in fig. 9 (b), the 2 nd voice coil motor that realizes the shake correction function is composed of a magnet 74b magnetized to N and S poles on the case 4 side and a coil 75b on the bottom cover 6 side. Although the 2 nd voice coil motor is provided in 1 group, only the configurations of the components denoted by

reference numerals

74b and 75b will be described here.

Therefore, a current flows through the coil 75b, and a driving force is generated to move the housing 4 accommodating the lens barrel 3 along a predetermined one end of the plane perpendicular to the optical axis direction of the lens 2. Specifically, when a current flows through the coil 75b, the direction of the current and the magnetic flux (see arrow Y2) passing through the coil 75b from the magnet 74b reciprocate the housing 4 in a straight direction (arrow Y22 direction: X axis direction in fig. 10) on the optical axis direction vertical plane of the lens 2 in accordance with fleming's left-hand rule. The magnet 74a and the coil 75a constituting the other 2 nd voice coil motor are used to reciprocate the housing 4 in a linear direction (Y-axis direction) orthogonal to the one linear direction (X-axis direction) on the optical axis direction vertical plane of the lens 2. That is, the 2 nd voice coil motor 2 reciprocates the housing 4 in each of the linear directions orthogonal to each other on the vertical plane in the optical axis direction of the lens 2.

At this time, the housing 4 and the bottom cover 6 are attracted and connected to each other by the connecting spring 79 in a state of holding and supporting the guide ball 78. The housing 4 is thereby reciprocated on the bottom cover 6 by guiding and supporting the guide balls 78 by the driving of the 2 nd voice coil motor. Further, since the connection spring 79 is flexible in the direction perpendicular to the optical axis direction of the lens 2, when the 2 nd voice coil motor is driven, although it is deflected as indicated by arrow Y23 in fig. 10, the housing 4 and the bottom cover 6 are always urged so as to attract each other, and therefore the housing 4 and the bottom cover 6 are always connected by holding the distance of the diameter length of the support guide ball 78. Therefore, the

magnets

74a and 74b disposed on the housing 4 and the

coils

75a and 75b disposed on the bottom cover 6, which constitute the 2 nd voice coil motor, are always fixed in distance from each other. As a result, the 2 nd voice coil motor is stably driven.

Further, since the 2 nd voice coil motor is guided by the support guide balls 78, it can withstand dropping and the like, and is highly reliable. The 2 nd voice coil motor having the above-described configuration does not have a resonance system because it is not a Spring-mass system (Spring-mass system). From this viewpoint, reliability can be improved.

The mounting positions of the 1 st and 2 nd voice coil motors are not limited to the above-described positions, and may be set at any positions, and the shapes of the components constituting the voice coil motors are not limited to the above-described shapes, and the number thereof may be arbitrary.

In the present embodiment, the case where the lens barrel 3 has the

magnets

71a and 71b and the housing 4 has the

coils

72a and 72b and the

yokes

73a and 73b in the 1 st voice coil motor will be described, but the lens barrel 3 may have the

coils

72a and 72b and the

yokes

73a and 73b and the housing 4 may have the

magnets

71a and 71 b. In the present embodiment, the case 4 and the bottom cover 6 of the 2 nd voice coil motor have the

magnets

74a and 74b and the

coils

75a and 75b, respectively, but the case 4 and the bottom cover 6 may have the

magnets

74a and 74b and the

coils

75a and 75b, respectively.

The present invention has been described above with reference to the above embodiments and the like, but the present invention is not limited to the above embodiments. It will be understood by those skilled in the art that various changes in form and details of the present invention may be made without departing from the spirit and scope of the invention.

Claims

1. A lens driving device, comprising:

a lens barrel mounted with a lens;

a housing surrounding the lens barrel, accommodating the lens barrel;

a 1 st voice coil motor that moves the lens barrel relative to the housing in an optical axis direction of the lens; and

a 1 st guide portion that guides the lens barrel to move relative to the housing,

the 1 st voice coil motor is provided with a magnet at one end in the housing or the lens barrel, and a coil and a yoke at the other end, the yoke being configured to: the yoke receives the magnetic force attracted by the magnet and presses the lens barrel toward the 1 st guide portion,

the lens driving apparatus further includes:

a support cover for supporting the housing on one end surface side of the lens;

a 2 nd voice coil motor that moves the housing relative to the support cover in a vertical direction opposite to an optical axis direction of the lens;

a 2 nd guide portion which is disposed between the housing and the support cover, abuts against the housing and the support cover, and guides the movement of the housing relative to the support cover; and

a connecting member connecting the housing and the support cover,

the 2 nd voice coil motor is provided with a magnet at one end in the housing or the support cover and a coil and a magnetic yoke at the other end,

the connection member is configured to be connected to the housing and the support cover with a predetermined distance therebetween.

2. The lens driving device according to claim 1,

the connecting member is configured to apply a force that attracts the housing and the support cover to each other through the 2 nd guide portion.

3. The lens driving device according to claim 2,

the connecting member is configured to have flexibility in a direction perpendicular to the optical axis direction of the lens.

4. The lens driving device according to claim 3,

the connecting member is constituted by a tension spring that exerts a force that attracts the housing and the support cover to each other.

5. The lens driving device according to claim 1,

the 2 nd guide portion is configured by a plurality of spherical bodies, which are respectively arranged at respective positions predetermined with respect to the support cover and rotate at the respective arranged positions.

6. The lens driving device according to claim 1,

the 2 nd voice coil motor comprises 2 voice coil motors, 2 voice coil motors make the shell move respectively on two linear directions of mutual quadrature on the perpendicular face that the optical axis direction of lens is relative.

7. The lens driving device according to any one of claims 1 to 6,

the 1 st voice coil motor is respectively arranged at 2 adjacent positions in the lens barrel with a roughly rectangular shape,

the 1 st guide part is arranged at the middle position of the two 1 st voice coil motors,

the yoke is configured to: the lens barrel is pressed toward the 1 st guide portion by a resultant force of magnetic forces generated by the yokes of the two 1 st voice coil motors.

8. The lens driving device according to claim 7,

the 1 st guide portion has a main guide portion disposed in the vicinity of an angle between two adjacent sides of the substantially rectangular lens barrel in which the two 1 st voice coil motors are arranged, and a sub guide portion disposed in the vicinity of an angle on the other side on a diagonal line opposite to an angle of the substantially rectangular lens barrel in which the main guide portion is arranged,

the two 1 st voice coil motors are configured such that the magnetic forces of the yokes respectively provided therein and attracted by the magnets are different from each other,

the sub-guide portion is configured to support a pressing force generated by the lens barrel that is biased to rotate about the main guide portion as a fulcrum by a resultant force of magnetic forces generated by the yokes of the two 1 st voice coil motors.

9. The lens driving device according to claim 8,

in the vicinity of the other 2-side portion different from the adjacent two-side portion of the substantially rectangular lens barrel in which the 1 st voice coil motor is arranged, 2 voice coil motors for moving the housing in 2 linear directions orthogonal to each other on a vertical surface facing the optical axis direction of the lens are arranged as the 2 nd voice coil motor.

10. A camera module is characterized in that a camera module is provided,

a lens driving device according to any one of claims 1 to 9 is mounted.