Drive device, photographic device, and electronic device

Abstract

Provided are a lens driving device, a photographic device, and an electronic device that can ensure smooth movement of a lens support. The lens driving device (12) includes a moving body (18) that supports a lens (14), a fixed body (16) within which the moving body (18) is disposed, a guiding mechanism (102) that guides the moving body (18) to move freely in the optical axis direction of the lens (14) relative to the fixed body (16), and a driving mechanism that moves the moving body (18) relative to the fixed body (16) in the optical axis direction. The driving mechanism includes a magnet (66) disposed on one side of the moving body (18) and the fixed body (16), a coil (76) disposed on the other side of the moving body (18) and the fixed body (16) and disposed opposite to the magnet (66), and a magnetic member (70) disposed parallel to the coil (76). By the magnet (66) and the magnetic member (70), the moving body (18) is pressed against the fixed body (16) by the guiding mechanism (102), and an opening (100) is formed in the magnetic member (70).

Description

[0001] The present invention relates to a driving device, a photographic device, and an electronic device.

Background Art

[0002] Small photographic devices are mounted in electronic devices such as mobile phones or smartphones. As is well known, for example, as described in Patent Document 1, such small cameras have a shake compensation function.

[0003]

Prior Art Documents

[0004]

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006]

Technical Problem to be Solved by the Invention

[0007] The camera module of the above Patent Document 1 has a lens support body that supports a lens and a frame body around the lens support body. In order to support the lens support body to move freely relative to the frame body in a direction orthogonal to the optical axis direction of the lens, a plurality of balls are used. Moreover, in this camera module, a magnet is provided and a magnetic member is disposed opposite to the magnet, and the balls are clamped between the lens support body and the frame body by the attractive force between the magnet and the magnetic member.

[0008] However, there is a problem with the above arrangement. If a force not less than the attractive force is generated between the magnet and the magnetic member due to dropping or the like, the lens support body separates from the ball, and then the lens support body comes into contact with the ball again. As a result, the lens support body and the frame that are in point contact with the ball are subjected to an impact, causing the portion in contact with the ball to be dented and cracked, which may cause the lens support body to not move smoothly.

[0009] The present invention aims to solve the above problems that have existed for a long time, and provides a lens driving device, a photographic device, and an electronic device that can ensure the smooth movement of the lens support body.

[0010]

Technical Solution

[0011] One aspect of the present invention is a lens driving device, which includes a moving body that supports a lens, a fixed body that houses the moving body therein, a guiding mechanism that guides the moving body to move freely in the optical axis direction of the lens relative to the fixed body, and a driving mechanism that moves the moving body relative to the fixed body in the optical axis direction. The driving mechanism includes a magnet disposed on one of the moving body and the fixed body, a coil disposed on the other of the moving body and the fixed body and disposed opposite to the magnet, and a magnetic member disposed parallel to the coil. By the magnet and the magnetic member, the moving body is pressed against the fixed body by the guiding mechanism, and an opening is formed in the magnetic member.

[0012] Preferably, the opening is divided into two parts in the optical axis direction or divided into two parts in a direction orthogonal to the optical axis direction.

[0013] Moreover, preferably, the guiding mechanism includes a guiding shaft provided on the fixed body and a guiding hole provided on the moving body for receiving the guiding shaft, and the guiding shaft and the guiding hole are in line contact at two places through the pressing.

[0014] Moreover, preferably, on the interface viewed from the optical axis direction, the guiding shaft is circular, and the guiding hole has a V-shaped opening toward the fixed body side.

[0015] Another aspect of the present invention is a photographic apparatus, which includes the lens driving device and a lens supported by the lens support.

[0016] Another aspect of the present invention is an electronic device, which includes the photographic apparatus.

[0017]

Advantages of the Invention

[0018] According to the present invention, a driving mechanism for moving the moving body in the optical axis direction is formed by the coil, the magnet, and the magnetic member that face each other. An opening is formed in the magnetic member. Thus, the attractive force generated between the magnet and the magnetic member can be adjusted to a desired value, so that the moving body can move smoothly in the optical axis direction.

[0019] Another aspect of the present invention is an electronic device, which includes the photographic apparatus.

[0020]

Advantages of the Invention

[0021] According to the present invention, the guide protrusion and the guide groove extend along the moving direction of the lens support on one side and the other side in a direction orthogonal to the optical axis direction of the lens. The guide protrusion and the guide groove are in line contact at two places on one side in the direction orthogonal to the optical axis direction, and in surface contact on the other side. Therefore, the lens driving device of the present invention can reduce the impact received in the optical axis direction, and at the same time accurately position the guide protrusion and the guide groove, thereby ensuring the smooth movement of the lens support.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022]

Figure 1

[0023]

Figure 2

[0024]

Figure 3

[0025]

Figure 4

[0026]

Figure 5

[0027]

Figure 6

[0028] Figure 7A is Figure 6 a sectional view taken along line VIIA-VIIA of Figure 7B and Figure 6 is a sectional view taken along line VIIB-VIIB of

[0029] Figure 8A is Figure 7A an enlarged sectional view of part VIIIA of Figure 8B and Figure 7A is an enlarged sectional view of part VIIIB of

[0030] Figure 9A is Figure 7B an enlarged sectional view of part IXA of Figure 9B and Figure 7B is an enlarged sectional view of part IXB of

[0031]

Figure 10

[0032]

Reference Signs

[0033] 10 Camera device

[0034] 12 Lens driving device

[0035] 14 Lens

[0036] 16 Fixed body

[0037] 18 Moving body

[0038] 20 Lens support

[0039] 22 First frame body

[0040] 24 Lens mounting hole

[0041] 26 First moving body plate

[0042] 28 Second moving body plate

[0043] 30 First cover

[0044] 32, 34, 36 Opening

[0045] 38 Orthogonal direction guiding mechanism

[0046] 40 First guiding mechanism

[0047] 42 Second guiding mechanism

[0048] 44, 44A, 44B Lower guiding protrusion

[0049] 46, 46A, 46B Lower guiding groove

[0050] 48, 48A, 48B Upper guiding protrusion

[0051] 50, 50A, 50B Upper guiding groove

[0052] 52 First magnet

[0053] 54 Second magnet

[0054] 56 First magnetic member

[0055] 58 Second magnetic member

[0056] 60 Mounting portion

[0057] 62 Mounting hole

[0058] 64 Mounted Part

[0059] 66 Third Magnet

[0060] 68 Second Frame Body

[0061] 70 Third Magnetic Component

[0062] 72 First Coil

[0063] 74 Second Coil

[0064] 76 Third Coil

[0065] 78 Flexible Printed Substrate

[0066] 80 Base

[0067] 82 Second Cover

[0068] 84, 86 Through-Holes

[0069] 88 Opening

[0070] 90 Terminal Part

[0071] 92 Y-Direction Position Detection Element

[0072] 94 X-Direction Position Detection Element

[0073] 96 Z-Direction Position Detection Element

[0074] 98 Connecting Part

[0075] 100 Separation Opening

[0076] 102 Optical Axis Direction Guide Mechanism

[0077] 104 Third Guide Mechanism

[0078] 106 Fourth Guide Mechanism

[0079] 108 +X-Side Guide Shaft

[0080] 110 +X-Side Guide Hole

[0081] 110A Guide Surface

[0082] 110B Y-Side Surface

[0083] 112 -X-Side Guide Shaft

[0084] 114 -X-Side Guide Groove

[0085] 114A Protrusion

[0086] 116 Lower Fixed Part

[0087] 118 Upper fixing part

[0088] 120 Insertion hole

[0089]

Specific embodiment

[0090] A specific embodiment of the present invention will be described below with reference to the drawings. The following embodiments show the lens driving device, the imaging device, and the electronic device of the present invention by way of example, but the present invention is not intended to be limited to the following embodiments.

[0091] Figure 1 The imaging device 10 involved in the embodiment of the present invention is shown. The imaging device 10 is mounted on an electronic device such as a mobile phone or a smart phone, and has a lens driving device 12 and a lens 14 mounted on the lens driving device 12.

[0092] Moreover, in the following description, for the sake of convenience, the optical axis direction of the lens 14 is referred to as the Z direction, one direction orthogonal to the Z direction is referred to as the X direction, and the direction orthogonal to both the Z direction and the X direction is referred to as the Y direction. Moreover, the object side of the optical axis (corresponding to Figure 1 the upper side in ) is referred to as the upper side, and the opposite side thereof (i.e., the side where the image sensor is disposed not shown) is referred to as the lower side.

[0093] The lens driving device 12 has a fixed body 16 and a moving body 18 that is supported relative to the fixed body 16 and is free to move in the optical axis direction. The moving body 18 is disposed inside the fixed body 16.

[0094] The moving body 18 is as Figure 2 , Figure 3 shown, and has a lens support 20 that supports the lens 14 and a first frame body 22 that is a frame body surrounding the periphery of the lens support 20. When observing the lens support 20 and the first frame body 22 from above, their outer shapes are substantially rectangular.

[0095] Inside the lens support 20, when observed from the Z direction, a circular lens mounting hole 24 is formed, which penetrates from the upper side to the lower side. The lens 14 is mounted on the lens mounting hole 24.

[0096] The first frame body 22 includes a first moving body plate 26, a second moving body plate 28, and a first cover 30, which are each substantially quadrangular in shape when viewed from above. The first moving body plate 26 and the second moving body plate 28 are made of engineering plastics, such as liquid crystal polymer (LCP), polyoxymethylene, polyamide, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, etc. The first cover 30 is made of, for example, metal. Openings 32, 34, and 36 through which light passes are respectively formed in the first moving body plate 26, the second moving body plate 28, and the first cover 30, and penetrate from the upper side to the lower side. The openings 32, 34, and 36 are each substantially circular.

[0097] The first frame body 22 supports the lens support 20 to move freely in two directions, the first direction (i.e., the X direction) and the second direction (i.e., the Y direction). Specifically, a guiding mechanism (i.e., the orthogonal direction guiding mechanism 38) is provided on the lens support 20 and the first frame body 22, supporting the lens support 20 to move freely in the X direction and the Y direction relative to a specified component (i.e., the second moving body plate 28) constituting the frame body. The orthogonal direction guiding mechanism 38 is composed of a first guiding mechanism 40 provided on one side (the lower side) in the Z direction and a second guiding mechanism 42 provided on the other side (the upper side) in the Z direction.

[0098] The first guiding mechanism 40 is composed of a lower guiding protrusion 44 protruding downward in the -Z direction from the lower side of the first moving body plate 26 and a lower guiding groove 46 recessed in the -Z direction so that the lower guiding protrusion 44 can be inserted above the second moving body plate 28. The lower guiding protrusion 44 and the lower guiding groove 46 are formed near the four corners of the first moving body plate 26 and the second moving body plate 28, respectively, and extend along the X direction.

[0099] Since the lower guiding protrusion 44 and the lower guiding groove 46 extend along the X direction respectively, they can only move relative to each other in the X direction, restricting their movement in the Y direction. Thus, the first moving body plate 26 can only move relative to the second moving body plate 28 in the X direction, restricting its movement in the Y direction. In other words, the lens support 20 can move in the X direction relative to the second moving body plate 28 together with the first moving body plate 26 through the first guiding mechanism 40.

[0100] Moreover, the lower guiding protrusion 44 and the lower guiding groove 46 are arranged on one side and the other side in the direction (i.e., the Y direction) orthogonal to the moving direction of the first moving body plate 26. Specifically, the lower guiding protrusion 44 has two lower guiding protrusions 44A, 44A provided on one side (-Y side) in the Y direction and two lower guiding protrusions 44B, 44B provided on the other side (+Y side) in the Y direction. Moreover, the lower guiding groove 46 has two lower guiding grooves 46A, 46A provided on one side in the Y direction and two lower guiding grooves 46B, 46B provided on the other side in the Y direction.

[0101] As Figure 7A 、 Figure 8B shown, when viewed from the X direction, the cross-sections of the lower guide grooves 46A, 46A on one side in the Y direction are V-shaped. The shape of the lower guide grooves 46A, 46A is such that the width becomes smaller as it approaches the bottom of the groove. In order to make the width smaller as it approaches the bottom of the groove, the guide grooves are inclined. Moreover, the lower guide protrusions 44A, 44A are semi-circular in shape. Thus, the arc portions of the lower guide protrusions 44A, 44A and the linear portions of the lower guide grooves 46A, 46A are in line contact with each other at two places. Moreover, a space is formed between the lower guide protrusions 44A, 44A and the lower guide grooves 46A, 46A for the portion between the two line contact positions and the bottom of the groove. The cross-sectional shape of the lower guide protrusions 44A, 44A may also be square. In this case, the cross-sectional shape of the lower guide grooves 46A, 46A may also be V-shaped or U-shaped. By making line contact at two places, the position of the lower guide protrusions 44A, 44A relative to the lower guide grooves 46A, 46A in the Y direction can be determined without deviation.

[0102] Moreover, as Figure 7A 、 Figure 8A shown, when viewed from the X direction, the cross-sections of the lower guide protrusions 44B, 44B and the lower guide grooves 46B, 46B on the other side in the Y direction are square respectively. That is, the lower guide grooves 46B, 46B have a plane extending in a direction orthogonal to the extending direction of the lower guide protrusions 44B, 44B and the lower guide grooves 46B, 46B at the bottom of the groove, and the lower guide protrusions 44B, 44B have a plane in surface contact with this plane. Thus, the lower guide protrusions 44B, 44B and the lower guide grooves 46B, 46B are in surface contact with each other on the other side in the Y direction. Thus, the height of the first moving body plate 26 relative to the second moving body plate 28 in the Z direction can be determined. Moreover, the plane of the lower guide grooves 46B, 46B is larger than the lower guide protrusions 44B, 44B. Therefore, even if the distance between the lower guide protrusions 44A, 44A and the distance between the lower guide protrusions 44B, 44B are different from the distance between the lower guide grooves 46A, 46A and the distance between the lower guide grooves 46B, 46B due to manufacturing errors, assembly can still be carried out so that the first moving body plate 26 moves smoothly.

[0103] The second guide mechanism 42 is composed of an upper guide protrusion 48 protruding upward in the +Z direction from the upper surface of the first moving body plate 26 and an upper guide groove 50 recessed in the +Z direction so that the upper guide protrusion 48 can be inserted below the lens support 20. The upper guide protrusion 48 and the upper guide groove 50 are formed near the four corners of the first moving body plate 26 and the lens support 20 respectively and extend along the Y direction.

[0104] The upper guide protrusions 48 and the upper guide grooves 50 extend in the Y direction respectively, so they can only move relative to each other in the Y direction, restricting their movement in the X direction. Thus, the lens support 20 can only move relative to the first moving body plate 26 in the Y direction, restricting its movement in the X direction. In other words, due to the second guiding mechanism 42, the lens support 20 can move relative to the first moving body plate 26 in the Y direction. Combining with the first guiding mechanism 40, the lens support 20 can move relative to the second moving body plate 28 in the X direction and the Y direction respectively. Moreover, the first guiding mechanism 40 and the second guiding mechanism 42 are independent guiding mechanisms. Even when driving in the X-Y directions simultaneously, no force in the rotational direction around the Z direction is generated, preventing the lens support 20 from vibrating in the rotational direction.

[0105] Moreover, the upper guide protrusions 48 and the upper guide grooves 50 are arranged on one side and the other side in the direction orthogonal to the moving direction of the lens support 20 (i.e., the X direction). Specifically, the upper guide protrusions 48 have two upper guide protrusions 48A, 48A arranged on one side in the X direction (-X side) and two upper guide protrusions 48B, 48B arranged on the other side in the X direction (+X side). Moreover, the upper guide grooves 50 have two upper guide grooves 50A, 50A arranged on one side in the X direction and two upper guide grooves 50B, 50B arranged on the other side in the X direction.

[0106] As Figure 7B , Figure 9A shown, when observed from the Y direction, the cross-sections of the upper guide grooves 50A, 50A on one side in the X direction are V-shaped. The shape of the upper guide grooves 50A, 50A is such that the width becomes smaller as it approaches the bottom of the groove. To make the width smaller as it approaches the bottom of the groove, the guide grooves are inclined. Moreover, the upper guide protrusions 48A, 48A are semi-circular. Thus, the arc portions of the upper guide protrusions 48A, 48A and the linear portions of the upper guide grooves 50A, 50A are in line contact at two places. Moreover, for the portions between the two line contact positions and the bottom of the groove, a space is formed between the upper guide protrusions 48A, 48A and the upper guide grooves 50A, 50A. The cross-sectional shape of the upper guide protrusions 48A, 48A can also be square. In this case, the cross-sectional shape of the upper guide grooves 50A, 50A can also be V-shaped or U-shaped. By making line contact at two places, the position of the upper guide grooves 50A, 50A relative to the upper guide protrusions 48A, 48A in the X direction can be determined without deviation.

[0107] Moreover, as Figure 7B , Figure 9BAs shown, when viewed from the Y direction, the cross-sections of the upper guide protrusions 48B, 48B and the upper guide grooves 50B, 50B on the other side in the X direction are square respectively. That is, the upper guide grooves 50B, 50B have a plane extending in a direction orthogonal to the extending direction of the upper guide protrusions 48B, 48B and the upper guide grooves 50B, 50B at the bottom of the grooves, and the upper guide protrusions 48B, 48B have a plane that makes surface contact with this plane. Thus, the upper guide protrusions 48B, 48B and the upper guide grooves 50B, 50B make surface contact with each other on the other side in the X direction. Thereby, the height of the lens support 20 relative to the first moving body plate 26 in the Z direction can be determined. Moreover, the plane of the upper guide grooves 50B, 50B is larger than the upper guide protrusions 48B, 48B. Therefore, even if the distance between the upper guide protrusions 48A, 48A and the upper guide protrusions 48B, 48B is different from the distance between the upper guide grooves 50A, 50A and the upper guide grooves 50B, 50B due to manufacturing errors, assembly can be carried out and the lens support 20 can move smoothly.

[0108] Outside the lens support 20, plate-shaped first magnet 52 and second magnet 54 are fixed. The first magnet 52 faces its plate surface in the Y direction and is arranged on one side in the Y direction, that is, the side where the lower guide protrusions 44A, 44A and the lower guide grooves 46A, 46A make line contact. The second magnet 54 faces its plate surface in the X direction and is arranged on one side in the X direction, that is, the side where the upper guide protrusions 48A, 48A and the upper guide grooves 50A, 50A make line contact. The first magnet 52 sets the S pole on the plate surface facing the Y direction side and the N pole on the other plate surface. The second magnet 54 sets the S pole on the plate surface facing the X direction side and the N pole on the other plate surface.

[0109] Below the second moving body plate 28, a first magnetic member 56 and a second magnetic member 58 composed of magnetic materials are respectively arranged. The first magnetic member 56 is arranged along the X direction on one side in the Y direction and is parallel to the first magnet 52. The second magnetic member 58 is arranged along the Y direction on one side in the X direction and is parallel to the second magnet 54. Thus, the first magnetic member 56 and the first magnet 52 face each other in the Z direction with the second moving body plate 28 in between. Similarly, the second magnetic member 58 and the second magnet 54 face each other in the Z direction with the second moving body plate 28 in between.

[0110] On one side in the Y direction, the first magnet 52 and the first magnetic member 56 are arranged between the combination of the lower guide protrusion 44A and the lower guide groove 46A on one side and the combination of the lower guide protrusion 44A and the lower guide groove 46A on the other side, and attract each other. For this reason, compared with arranging the first magnet 52 and the first magnetic member 56 in other positions, the lower guide protrusions 44A, 44A and the lower guide grooves 46A, 46A that are in line contact with each other can make a stronger contact, so the positioning in the Y direction can be carried out more accurately.

[0111] On one side in the X direction, the second magnet 54 and the second magnetic member 58 are arranged between the combination of the upper guide protrusion 48A and the upper guide groove 50A on one side and the combination of the upper guide protrusion 48A and the upper guide groove 50A on the other side, and attract each other. For this reason, compared with arranging the second magnet 54 and the second magnetic member 58 in other positions, the upper guide grooves 50A, 50A and the upper guide protrusions 48A, 48A that are in line contact with each other can make a stronger contact, so the positioning in the X direction can be carried out more accurately.

[0112] At the four corners of the first cover 30, mounting portions 60 are provided and extend downward in the Z direction. Mounting holes 62 in the shape of a quadrangle are formed on each of the mounting portions 60. Moreover, mounted portions 64 are formed at the four corners of the second moving body plate 28 and protrude laterally. The mounting holes 62 are inserted into the mounted portions 64, whereby the first cover 30 is fixed to the second moving body plate 28. Moreover, between the lower part of the first cover 30 and the upper part of the lens support 20, as Figure 7A , Figure 7B shown, a necessary minimum clearance including errors caused by tolerances and the like is formed. Thus, even when impacted, the lens support 20, the first moving body plate 26, and the second moving body plate 28 are regulated and will not generate an excessive distance between each other.

[0113] On the second moving body plate 28, on the outer surface on the side opposite to the side where the first magnet 52 is provided (i.e., the +Y side), a plate-shaped third magnet 66 is fixed with its plate surface facing the Y direction. The third magnet 66 is divided into two parts, the upper side and the lower side in the Z direction, and S poles and N poles are arranged on the plate surface, and this configuration makes the upper and lower polarities opposite.

[0114] As Figure 1As shown, the fixed body 16 includes a second frame body 68 having a base 80 and a second cover 82, a third magnetic member 70 mounted on the second frame body 68, a first coil 72, a second coil 74, a third coil 76, and a flexible printed circuit board 78. The base 80 and the second cover are each made of resin or non-magnetic metal and are quadrangular in shape when viewed from above in the Z direction. The second cover 82 is embedded outside the base 80 to form the second frame body 68. The second frame body 68 surrounds the periphery of the first frame body 22 of the moving body 18. Through holes 84 and 86 are formed in the base 80 and the second cover 82 to allow light to pass through or to insert the lens 14.

[0115] Moreover, as Figure 1 , Figure 4 shown, openings 88 that are open upward in the Z direction are respectively formed on four side surfaces of the base 80. Moreover, the flexible printed circuit board 78 is arranged to surround three side surfaces of the base 80. That is, the flexible printed circuit board 78 is bent into a U shape to surround two side surfaces orthogonal to the Y direction of the base 80 and one side surface (-X side) orthogonal to the X direction.

[0116] On the inner side of the flexible printed circuit board 78, the first coil 72 and the third coil 76 are fixed on two surfaces orthogonal to the Y direction, and the second coil 74 is fixed on one surface orthogonal to the X direction. A terminal portion 90 is provided at the lower portion of the flexible printed circuit board 78 in the Z direction, and current, signals, etc. are supplied through the terminal portion 90.

[0117] Moreover, as Figure 5 shown, on the inner side of the flexible printed circuit board 78, a Y-direction position detection element 92 is arranged in the middle of the first coil 72, an X-direction position detection element 94 is arranged in the middle of the second coil 74, and a Z-direction position detection element 96 is arranged adjacent to the third coil 76.

[0118] The first coil 72 and the Y-direction position detection element 92 are arranged adjacent to the inner side of the base 80 within the opening 88 and face the first magnet 52. Similarly, the second coil 74 and the X-direction position detection element 94 are arranged within the opening 88 and face the second magnet 54. Moreover, the third coil 76 and the Z-direction position detection element 96 are arranged within the opening 88 and face the third magnet 66.

[0119] Moreover, as Figure 1 shown, outside the portion where the third coil 76 of the flexible printed circuit board 78 is fixed, a third magnetic member 70 made of a magnetic body is arranged parallel to the third coil 76. The third magnetic member 70 is fixed to the side surface of the base 80 by being closely attached to the flexible printed circuit board 78. The third magnetic member 70 and the third magnet 66 sandwich the flexible printed circuit board 78 and the third coil 76 and face each other.

[0120] Magnetic flux from the third magnet 66 flows toward the third magnetic member 70, generating an attractive force between the third magnet 66 and the third magnetic member 70. For this reason, an attractive force in the Y direction with respect to the fixed body 16 is generated on the moving body 18.

[0121] Two partition openings 100, 100 that are separated into two parts in the X direction by a connecting portion 98 extending in the Z direction are formed on the third magnetic member 70. The connecting portion 98 may also extend in the Y direction. In this case, the partition openings 100, 100 are separated into two parts in the Z direction. The third magnetic member is made of magnetic stainless steel or iron that has been plated. By forming the partition openings 100, 100 on the third magnetic member 70, the attractive force between it and the third magnet 66 can be adjusted to a desired strength. In other words, the driving force required to move in the Z direction can be reduced, and at the same time, when an external impact is applied, the damage to the optical axis direction guiding mechanism 102 described below can be reduced.

[0122] As Figure 1 shown, the moving body 18 is supported by the optical axis direction guiding mechanism 102 and can move in the Z direction with respect to the fixed body 16. In other words, the optical axis direction guiding mechanism 102 guides the first frame body 22 to move freely in the Z-axis direction with respect to the second frame body 68. That is, thereby, the lens support body 20 is guided and moves freely in the optical axis direction together with the first frame body 22. The optical axis direction guiding mechanism 102 is composed of a third guiding mechanism 104 and a fourth guiding mechanism 106. The third guiding mechanism 104 is composed of a +X side guiding shaft 108 provided on the second frame body 68 and a +Z side guiding hole 110 provided on the moving body 18 for receiving the +X side guiding shaft 108. The fourth guiding mechanism 106 is composed of a -X side guiding shaft 112 provided on the second frame body 68 and a -X side guiding groove 114 provided on the moving body 18.

[0123] In the present embodiment, the +X side guiding shaft 108 and the -X side guiding shaft 112 are cylindrical and extend in the Z direction, and are composed of, for example, ceramics, metal, or resin. The +X side guiding shaft 108 and the -X side guiding shaft 112 are arranged near the corners on the inner side of the side surface of the base 80 where the third coil 76 is arranged. Moreover, the +X side guiding shaft 108 and the -X side guiding shaft 112 are circular in the X_Y direction cross-section, but only a part may be circular, or it may be elliptical. It may also be a polygonal shape such as a quadrangle.

[0124] Near the corners on the side of the third coil 76 disposed on the bottom surface portion around the through hole 84 of the abutment 80, lower fixing portions 116, 116 forming a cylindrical insertion groove are provided. At the lower fixing portions 116, 116, the lower ends of the +X side guide shaft 108 and the -X side guide shaft 112 are inserted and fixed. Moreover, upper fixing portions 118, 118 bent in the Y direction are formed at both ends in the X direction at the upper end of the third magnetic member 70. Insertion holes 120 are formed in the respective upper fixing portions 118. The upper ends of the +X side guide shaft 108 and the -X side guide shaft 112 are inserted and fixed in the insertion holes 120, 120. Thus, the +X side guide shaft 108 and the -X side guide shaft 112 are fixed to the abutment 80. The third magnetic member 70 also functions to support the +X side guide shaft 108 and the -X side guide shaft 112. Compared with the case of using other components for support, the number of components can be reduced, and thus the +X side guide shaft 108 and the -X side guide shaft 112 can be stably supported.

[0125] As Figure 2 , Figure 6 shown, the +X side guide hole 110 is a hollow through hole that penetrates from the upper surface in the Z direction to the lower surface of the second moving body plate 28. Moreover, the -X side guide groove 114 extends and penetrates from the upper side in the Z direction to the lower side of the second moving body plate 28, and a groove opened toward the outside is formed in the -X direction.

[0126] As Figure 6 , Figure 10 shown, regarding the cross-sectional shape in the X - Y plane of the +X side guide hole 110, the -Y side has a V-shaped cross-section opening toward the fixed body side (i.e., the +Y side), and the +Y side has a square cross-section. The cross-sectional shape on the +Y side may also be a semi-circular shape.

[0127] Due to the adsorption force between the third magnet 66 mounted on the moving body 18 and the third magnetic member 70, the moving body 18 is pulled in the +Y direction. Thus, at least on the -Y side of the +X side guide hole 110, guide surfaces 110A, 110A having a V-shaped cross-section are formed, and line contact is made with the outer surface of the +X side guide shaft 108 at two locations when viewed from the Z direction. Thus, the moving body 18 can be accurately positioned with respect to the fixed body 16 in the X direction and the Y direction. Moreover, it is preferable that the square portion of the +X side guide hole 110 does not make line contact with the outer surface of the +X side guide shaft 108 and a very small gap is provided, but line contact may also be made.

[0128] Moreover, the -X side guide groove 114 is composed of two wall surfaces facing each other in the Y direction in the cross-section in the X_Y plane. Curved protruding portions 114A, 114A protruding in the Y direction are formed on the two wall surfaces. As Figure 10As shown, the center of the protrusion 114A on at least the -Y side contacts the outer surface of the -X side guide shaft 112. That is, the -X side guide groove 114 and the -X side guide shaft 112 are in point contact with each other at at least one point, whereby the frictional resistance becomes small. Moreover, it is preferable that the protrusion 114A on the +Y side does not make point contact with the outer surface of the -X side guide shaft 112, and a very small gap is provided, but line contact may also be made. Thus, since the moving body 18 is pushed toward the +X side guide shaft 108 and the -X side guide shaft 112 by magnetic force, it is not inclined with respect to the +X side guide shaft 108 and the -X side guide shaft 112. Moreover, if the lens 14 becomes larger, the weight of the moving body 18 carrying the lens 14 becomes larger. In such a case, conventionally, it has been necessary to increase the necessary adsorption force caused by this magnetic force, resulting in an increase in frictional force, and it has been necessary to make the increased driving force greater than the increased part of the lens weight. However, in the present embodiment, due to the guide shaft structure, it is not necessary to increase the necessary adsorption force caused by this magnetic force, and the driving force is small, thus solving the problem.

[0129] In the lens driving device 12, the first magnet 52 and the first coil 72 constitute a driving mechanism that moves the lens support 20 in the Y-axis direction relative to the second moving body plate 28. When the first coil 72 is energized, a current in the X direction flows through the first coil 72. The first magnet 52 facing the first coil 72 generates a magnetic flux having a Z-direction component, and thus a Lorentz force in the Y direction is generated on the first coil 72. Since the first coil 72 is fixed to the base 80, the corresponding reaction force generated on the first magnet 52 becomes a driving force relative to the lens support 20. The lens support 20 is guided by the second guide mechanism 42 to move in the Y direction.

[0130] If the energization of the first coil 72 is terminated after the lens support 20 has moved in the Y direction, the lens support 20 stops at the position when the energization of the first coil 72 is terminated due to the attraction between the first magnet 52 and the first magnetic body 56, the attraction between the second magnet 54 and the second magnetic body 58, the friction between the lower guide protrusion 44 and the lower guide groove 46, and the friction between the upper guide protrusion 48 and the upper guide groove 50.

[0131] Moreover, the second magnet 54 and the second coil 74 constitute a drive mechanism that moves the lens support 20 together with the first moving body plate 26 in the X-axis direction relative to the second moving body plate 28. When the second coil 74 is energized, a current in the Y direction flows through the second coil 74. The second magnet 54 facing the second coil 74 generates a magnetic flux with a Z-direction component, and thus a Lorentz force in the X direction is generated on the second coil 74. Since the second coil 74 is fixed to the base 80, the corresponding reaction force generated on the second magnet 54 becomes a driving force relative to the lens support 20 and the first moving body plate 26, and the lens support 20 and the first moving body plate 26 are guided by the first guiding mechanism 40 to move in the X direction.

[0132] If the energization of the second coil 74 is terminated after the lens support 20 and the first moving body plate 26 move in the X direction, due to the attraction between the first magnet 52 and the first magnetic body 56, the attraction between the second magnet 54 and the second magnetic body 58, the friction between the lower guiding projection 44 and the lower guiding groove 46, and the friction between the upper guiding projection 48 and the upper guiding groove 50, the lens support 20 and the first moving body plate 26 stop at the position when the energization of the second coil 74 is terminated.

[0133] The third magnet 66, the third coil 76, and the third magnetic member 70 constitute a drive mechanism that moves the moving body 18 in the optical axis direction relative to the fixed body 16. When the third coil 76 is energized, a current in the X direction flows through the third coil 76. The third magnet 66 facing the third coil 76 generates a magnetic flux in the Y direction, and thus a Lorentz force in the Z direction is generated on the third coil 76. Since the third coil 76 is fixed to the base 80, the corresponding reaction force generated on the third magnet 66 becomes a driving force relative to the moving body 18, and the moving body 18 is guided by the optical axis direction guiding mechanism 102 to move in the Z direction. That is, the lens support 20 moves in the optical axis direction.

[0134] If the energization of the third coil 76 is terminated after the moving body 18 moves in the Z direction, due to the attraction between the third magnet 66 and the third magnetic body 70, and the friction between the +X side guiding shaft 108 and the +X side guiding hole 110, and the -X side guiding shaft 112 and the -X side guiding groove 114, the lens support 20 included in the moving body 18 stops at the position when the energization of the third coil is terminated.

[0135] Here, it is assumed that the imaging device 10 is subjected to an impact in the Y direction. The +X side guide shaft 108 and the +X side guide hole 110, and the -X side guide shaft 112 and the -X side guide groove 114, even if separated, only return to their original positions immediately after separating by a very small distance, so the damage is extremely small. The lower side guide protrusions 44A, 44B and the lower side guide grooves 46A, 46B, and the upper side guide protrusions 48A, 48B and the upper side guide grooves 50A, 50B are respectively in a state of keeping contact, so there is almost no damage.

[0136] Here, it is assumed that the imaging device 10 is subjected to an impact in the X direction. The +X side guide shaft 108 and the +X side guide hole 110, and the -X side guide shaft 112 and the -X side guide groove 114, the lower side guide protrusions 44A, 44B and the lower side guide grooves 46A, 46B, and the upper side guide protrusions 48A, 48B and the upper side guide grooves 50A, 50B are respectively in a state of keeping contact, so there is almost no damage.

[0137] It is assumed that the imaging device 10 is subjected to an impact in the Z direction. The +X side guide shaft 108 and the +X side guide hole 110, and the -X side guide shaft 112 and the -X side guide groove 114 are respectively in a state of keeping contact, so there is almost no damage. The lower side guide protrusions 44A, 44B and the lower side guide grooves 46A, 46B, and the upper side guide protrusions 48A, 48B and the upper side guide grooves 50A, 50B, even if separated, only return to their original positions immediately after separating by a very small distance, and the contact state is a line contact or a surface contact, so there is almost no damage.

[0138] Thus, no matter in which direction the imaging device 10 is subjected to an impact, the damage to the lens driving device 12 of the present embodiment is extremely small or almost no damage. Therefore, smooth movement of the lens support 20 in the X, Y, and Z directions can be ensured.

[0139] In the above embodiment, an example is given of providing the lower side guide protrusions 44 and the upper side guide protrusions 48 on the first moving body plate 26, forming the lower side guide grooves 46 on the second moving body plate 28 facing it, and forming the upper side guide grooves 50 on the lens support 20. However, the positions of the protrusions and the grooves can also be swapped, forming guide grooves above and below the first moving body plate 26, and forming guide protrusions on the second moving body plate 28 and the lens support 20 to face them. Moreover, only the upper side or only the lower side can be swapped.

[0140] Moreover, in the above-described embodiment, an example was given in which the first coil 72, the second coil 74, the third coil 76, and the third magnetic body 70 are mounted on the fixed body 12, and the first magnet 52, the second magnet 54, and the third magnet 66 are mounted on the moving body 18. However, the first coil 72, the second coil 74, the third coil 76, and the third magnetic body 70 may also be mounted on the moving body 18, and the first magnet 52, the second magnet 54, and the third magnet 66 may be mounted on the fixed body 12.

[0141] Moreover, in the above-described embodiment, the lens driving device 12 used in the photographic apparatus 10 was described. However, the present invention can also be applied to other devices.

Claims

1. A lens driving device, comprising: A moving body that supports a lens, A fixed body that houses the moving body therein, A guiding mechanism that guides the moving body to move freely in the optical axis direction of the lens with respect to the fixed body, A driving mechanism that moves the moving body with respect to the fixed body in the optical axis direction, The driving mechanism includes a magnet disposed on one of the moving body and the fixed body, a coil disposed on the other of the moving body and the fixed body and disposed opposite to the magnet, and a magnetic member disposed parallel to the coil, Characterized in that, By the magnet and the magnetic member, the moving body is pressed against the fixed body by the guiding mechanism, An opening is formed in the magnetic member; the opening is divided into two parts in the optical axis direction, or is divided into two parts in a direction orthogonal to the optical axis direction, so as to adjust the adsorption force generated between the magnet and the magnetic member to a desired value.

2. The lens driving device according to claim 1, characterized in that, The guiding mechanism includes a guiding shaft provided on the fixed body and a guiding hole provided on the moving body for housing the guiding shaft, The guiding shaft and the guiding hole are in line contact at two places through the pressing.

3. The lens driving device according to claim 2, characterized in that, On the interface viewed from the optical axis direction, the guiding shaft is circular, and the guiding hole presents a V-shaped that opens toward the fixed body side.

4. A photographic device, characterized in that, Including the lens driving device according to any one of claims 1 to 3, and a lens supported by the moving body.

5. An electronic device, characterized in that, It has the photographic device according to claim 4.

Images