Blade driving device, camera device, and electronic device

Abstract

Provided is a vane driving device with high space efficiency for electromagnetic force generation. A vane driving device (11) defines a center axis O and includes: a plurality of vanes (8) disposed around the center axis O; two coil sets disposed around the center axis O, each having at least two coils (40) wound around the center axis O and separated along the center axis O; and a magnet (41) disposed between the two coil sets such that a magnetization surface faces the two coil sets, the coils (40) and the magnet (41) generating electromagnetic force in a circumferential direction of a circle centered on the center axis O to drive the vanes. Also provided are a camera device and an electronic device.

Description

TECHNICAL FIELD

[0001] The present application relates to a leaf driving device, a camera device, and an electronic device for an electronic device such as a smartphone. BACKGROUND

[0002] Various technologies have been proposed to adjust the light quantity of a lens body by a leaf of a sliding camera device. A camera module disclosed in Patent Literature 1 arranges three leaves around an entrance hole, drives the three leaves, and changes the amount of light entering a lens body. The camera module arranges three driving coils on an FPC (Flexible Printed Circuit) on the bottom surface of a housing that holds the leaves, arranges three driving magnets on a movable ring that faces the housing, and moves the leaves by rotating the movable ring around an optical axis using electromagnetic force generated by the driving coils and the driving magnets. A diaphragm mechanism device disclosed in Patent Literature 2 arranges two leaves called "Blades" in a substantially L shape around an entrance hole, drives the two leaves, and changes the amount of light entering a lens body. The diaphragm mechanism device arranges three coils on an FPC on the bottom surface of a base, arranges three permanent magnets on a rotating ring on the upper side of the base, and drives the leaves by rotating the rotating ring around an optical axis using electromagnetic force generated by the coils and the permanent magnets.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Chinese Patent Application Publication No. 110858048A

[0006] Patent Literature 2: Korean Patent Application Publication No. 2018-0105970A SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, the technologies described in Patent Literature 1 and Patent Literature 2 have a structure in which a plurality of groups are arranged around an entrance hole, and each group includes one coil and a magnet whose face facing the coil is magnetized to have two different magnetic poles. There is a problem that the spatial efficiency of electromagnetic force generation is low.

[0009] The present application has been achieved in view of the problem, and an object thereof is to provide a leaf driving device with high spatial efficiency of electromagnetic force generation.

[0010] MEANS FOR SOLVING THE PROBLEM

[0011] To solve the above problems, a blade driving device according to an embodiment of the present application includes a plurality of blades arranged around a central axis, two coil groups arranged around the central axis and separated in the direction of the central axis, each of the two coil groups having at least two coils with the direction of the central axis as a winding axis direction, and a magnet arranged between the two coil groups with a magnetization surface facing the two coil groups, the coils and the magnet generating an electromagnetic force in a circumferential direction of a circle centered on the central axis to drive the blades.

[0012] In this way, the magnet can extend in a direction orthogonal to a prescribed radius orthogonal to the central axis, sandwiching the radius, different magnetic poles can be arranged side by side in the direction of the radius, each coil group can have two coils arranged to sandwich the radius and facing the respective magnetic poles, and the two coils can each have two straight portions extending in a direction orthogonal to the prescribed radius, one of the two straight portions facing one of the magnetic poles and the other of the two straight portions facing the other of the magnetic poles.

[0013] In addition, the two coil groups can be electrically connected via an FPC having a width in the direction of the central axis and extending in the circumferential direction.

[0014] In addition, the blade driving device can further include a base, a movable ring rotatable about the central axis relative to the base, and a plate spring connecting the base and the movable ring and supporting the movable ring, the coil groups being fixed to the front side and the rear side of the movable ring, and the FPC being arranged on the outer side of the movable ring.

[0015] In addition, the plate spring can be electrically connected to the base and the FPC, and the FPC can be electrically connected to the coil groups at the front end edge and the rear end edge thereof.

[0016] In addition, the base can have a through hole, can be in the form of a circular ring, and a column portion can be erected together with a metal member from a peripheral portion surrounding the through hole, a hole can be provided in the movable ring, and for the plate spring, an inner edge portion can be electrically connected to the metal member and an outer edge portion can be electrically connected to the FPC via the hole.

[0017] In addition, the blade driving device can include a fixed portion and a movable ring rotatable about the central axis relative to the fixed portion to drive the blades by rotation, and one of the two coil groups and the magnet can be arranged in the fixed portion and the other can be arranged in the movable ring.

[0018] A camera device according to another preferred embodiment of the present application is characterized by comprising the above-described blade driving device.

[0019] An electronic device according to another preferred embodiment of the present application is characterized by comprising the above-described camera device.

[0020] Effects of the Invention

[0021] A blade driving device according to the present application is characterized by defining a center axis, comprising: a plurality of blades arranged around the center axis; two coil groups arranged around the center axis, separated in the direction of the center axis, each of the two coil groups having at least two coils with the direction of the center axis as a winding axis direction; and a magnet arranged between the two coil groups in such a manner that a magnetization surface faces the two coil groups, the coil and the magnet generating an electromagnetic force in the circumferential direction of a circle centered on the center axis to drive the blades. The electromagnetic force can be generated by the two coil groups arranged on both sides of the magnet. Thus, a blade driving device with high spatial efficiency of electromagnetic force generation can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a front view of a smartphone 19 equipped with a camera device 13 including a blade driving device 11 according to an embodiment of the present application.

[0023] Figure 2 is a perspective view of the blade driving device 11 of Figure 1 .

[0024] Figure 3 is an exploded perspective view of the blade driving device 11 of Figure 2 .

[0025] Figure 4 is a view of Figure 2 from which the front cover 1 is removed.

[0026] Figure 5 is a view of Figure 4 from which the front coil substrate 2 is removed. DETAILED DESCRIPTION

[0027] Hereinafter, an embodiment of the present application will be described with reference to the drawings. As shown in Figure 1 , a camera device 13 including a blade driving device 11 according to an embodiment of the present application is housed in a smartphone 19.

[0028] The camera device 13 includes a lens body 15, an image sensor 16 that converts light from the lens body 15 into an electrical signal, a lens drive device 12 that drives the lens body 15, and a blade drive device 11 that drives a blade 8 disposed on the front side of the lens body 15.

[0029] Hereinafter, the direction in which the light from the subject is incident will be appropriately referred to as the Z direction, a direction orthogonal to the Z direction will be appropriately referred to as the X direction, and a direction orthogonal to both the Z and X directions will be appropriately referred to as the Y direction. In addition, sometimes the side of the optical axis of the lens body 15 that is the subject side, i.e., the +Z side, will be referred to as the front side, and the side opposite to the subject where the image sensor 16 is located, i.e., the Z side, will be referred to as the rear side.

[0030] The lens drive device 12 has a lens carrier that supports the lens body 15 so that it can move along the optical axis. The blade drive device 11 is configured such that the optical axis of the lens body 15 becomes the central axis O of the blade drive device 11. The central axis O is an axis that passes through the center of the blade drive device 11 along the Z direction, and the direction of the central axis is the same as the Z direction. In addition, the direction of the central axis is also the front-rear direction. In the lens drive device 12, a metal receiving portion 17 is provided at one end of the front surface of the lens carrier on the -Y side and the +Y side. The receiving portion 17 extends along the +Z side. The lens drive device 12 supports the metal member 70 protruding towards the -Y side and the +Y side of the blade drive device 11 through the receiving portion 17, and supplies power to the blade drive device 11 through the receiving portion 17 and the metal member 70.

[0031] like Figure 3 As shown, the blade drive device 11 includes a front cover 1, a front coil base plate 2, a movable ring 3, an FPC 4, four magnets 41, a rear coil base plate 5, four plate springs 6, eight support members 60, a base 7, four blades 8, and a rear cover 9. The front cover 1, magnets 41, support members 60, and base 7 constitute a fixed part that does not move relative to the lens drive device 12. The front coil base plate 2 and the rear coil base plate 5 each constitute a coil assembly. The coil assembly can also be formed by arranging multiple coils 40 on a single plane, or by arranging multiple coils 40 on a predetermined plate.

[0032] The front cover 1 has a front side wall portion 101, an outer peripheral wall portion 102, and an inner peripheral wall portion 103. The inner peripheral wall portion 103 and the outer peripheral wall portion 102 extend from the inner and outer peripheral edges of the front side wall portion 101 along the -Z side, and the front cover 1 is annular when viewed from the direction of the central axis.

[0033] The front coil substrate 2 is annular with a four-sided inner side and an angular circular four-sided outer side. Two coils 40 are embedded in the +X side, -X side, +Y side, and -Y side of the through hole in the center of the front coil substrate 2, respectively. The coils 40 arranged in the +X side and -X side are side by side in the Y direction, and each coil 40 has two straight portions extending in the Y direction. The coils 40 arranged in the +Y side and -Y side are side by side in the X direction, and each coil 40 has two straight portions extending in the X direction.

[0034] The movable ring 3 is substantially circular with a width in the front and back. A table portion 371 and 370 protruding forward and backward, respectively, are present in the +X side, -X side, +Y side, and -Y side of the movable ring 3. An operating pin 37 protruding backward is further provided in each table portion 370. A gap 306 is provided in the +X+Y side, +X-Y side, -X+Y side, and -X-Y side of the inner surface of the movable ring 3. A hole 366 is provided in the +X-Y side and -X-Y side of the outer surface of the movable ring 3. The hole 366 is connected to the gap 306 in the +X-Y side and -X-Y side.

[0035] The FPC 4 is substantially the same as the movable ring 3 in that it has a width in the front and back and extends along the circumferential direction, and is arranged in the portion of the outer side of the movable ring 3 from the hole 366 in the +X-Y side to the hole 366 in the -X-Y side. A wiring portion 406 is provided in each of the two ends of the FPC 4. Two wiring portions 407 and 408 are provided in the front end edge and the rear end edge of the FPC 4, respectively.

[0036] The magnets 41 are mounted to the base 7 and are provided in the +X side, -X side, +Y side, and -Y side. The magnets 41 arranged in the +X side and -X side are plate-shaped bodies extending in the Y direction, are magnetized in the front and back directions, and are magnetized so that the inner circumferential side half and the outer circumferential side half become opposite magnetic poles. The magnets 41 arranged in the +Y side and -Y side are plate-shaped bodies extending in the X direction, are magnetized in the front and back directions, and are magnetized so that the inner circumferential side half and the outer circumferential side half become opposite magnetic poles.

[0037] The rear coil substrate 5 is annular with a four-sided inner side and an angular circular four-sided outer side. Two coils 40 are embedded in the +X side, -X side, +Y side, and -Y side of the through hole in the center of the rear coil substrate 5, respectively. The coils 40 arranged in the +X side and -X side are side by side in the Y direction, and each coil 40 has two straight portions extending in the Y direction. The coils 40 arranged in the +Y side and -Y side are side by side in the X direction, and each coil 40 has two straight portions extending in the X direction.

[0038] The plate-shaped spring 6 has an inner edge portion 61, an outer edge portion 62, and a wrist portion 63 elastically connecting them. The wrist portion 63 is formed of a wire-shaped elastic member.

[0039] The support member 60 is a plate-shaped body having an L-shaped portion that accommodates the corner of the magnet 41, as viewed from the direction of the center axis. The support member 60 is fixed to the base 7, and two sets thereof are used to sandwich and support the magnet 41 from both sides in the extending direction. The corner of the inner periphery side and the corner of the outer periphery side of the surface of the L-shaped portion of the support member 60 that faces the plate spring 6 after assembly are chamfered more greatly.

[0040] The base 7 is circular. In the base 7, four metal members 70 are embedded in a manner so as to surround the through hole in the center of the base 7. One end portion of the two metal members 70 on the +Y side is raised in a step-like manner from the outer edge of the +Y side of the base 7 to project outward, and one end portion of the two metal members 70 on the -Y side is raised in a step-like manner from the outer edge of the -Y side of the base 7 to project outward. The other end portion of the metal member 70 is raised from the peripheral portion that surrounds the through hole of the base 7 together with the column portion 706.

[0041] The +X side, -X side, +Y side, and -Y side of the inner periphery of the through hole that surrounds the base 7 are each provided with two steps 741 at intervals. The height in the front-rear direction of the step 741 is greater than the height in the front-rear direction of the rear coil substrate 5. The column portion 706 is raised from the peripheral portion that surrounds the through hole between the adjacent steps 741. The long hole 27 and the fixing pin 28 are provided at positions close to the outer periphery of the +X side, -X side, +Y side, and -Y side of the base 7, respectively. The long hole 27 is provided so as to extend along the tangential direction of the circle, and the fixing pin 28 extends toward the rear from the rear surface of the base 7.

[0042] The vane 8 is a flat plate, and four vanes 8 of the same shape are arranged at intervals of 90 degrees to form an opening in the center. A movable hole 87 and a fixed hole 88 are provided in a protruding portion that protrudes from the outer edge of the vane 8. The movable hole 87 extends in the intermediate direction of the radial direction and the tangential direction of the circle, and the fixed hole 88 is circular.

[0043] The rear cover 9 has a bottom surface portion 901 that is annular, and a rim portion 902 that protrudes from the outer periphery thereof toward the +Z side.

[0044] The vane driving device 11 is manufactured in the following manner.

[0045] First, the FPC 4 is attached to the outer peripheral surface of the movable ring 3. Next, the rear coil substrate 5 is placed between the two steps 370 from the rear side of the movable ring 3, and the two wiring portions 408 and the rear coil substrate 5 are electrically connected. Thereby, the assembly of the movable ring 3 is placed on the front surface of the solid plate 7 that is manufactured by embedding the metal members 70 in advance. At this time, the movable pin 37 is inserted into the long hole 27.

[0046] Next, the support members 60 are fixed to the front side surface of the table portion 741 of the base 7, and the magnets 41 are arranged and fixed to the support members 60 so as to be housed between the L-shaped portions of the two support members 60. Next, the outer edge portions 62 of the plate-like springs 6 are inserted and fixed to the slits 306 of the movable ring 3. Since the corners of the outer peripheral side of the support members 60 are chamfered, the work of applying an adhesive or the like can be performed. The outer edge portions 62 of the plate-like springs 6 inserted in the slits 306 in which the holes 366 are present and the contact portions 406 of the FPC 4 are electrically connected from the outside of the holes 366.

[0047] Next, the front-side coil substrate 2 is placed and fixed between the two table portions 371 from the front side of the movable ring 3, and the two lead portions 407 of the front-side coil substrate 2 are electrically connected. Next, the assembly of the movable ring 3 is slightly lifted and fixed to the inner edge portions 61 of the plate-like springs 6 and the column portions 706 of the base 7. At this time, the plate-like springs 6 electrically connected to the FPC 4 and the metal members 70 are electrically connected. Since the corners of the inner peripheral side of the support members 60 are chamfered, the work of applying an adhesive or performing electrical connection or the like can be performed. Thus, the front-side coil substrate 2 in which the coil 40 is buried and the movable ring 3 in which the rear-side coil substrate 5 is mounted are supported to the column portions 706 of the base 7 via the plate-like springs 6. In addition, the magnet 41 and the coil 40 of the front-side coil substrate 2 and the coil 40 of the rear-side coil substrate 5 face each other in the front-rear direction.

[0048] Next, the vane 8 is installed in the base 7. The installation is performed in such a manner that the fixing pin 28 of the base 7 is inserted into the fixing hole 88 of the vane 8 and the movable pin 37 of the movable ring 3 further extended in the rearward direction from the long hole 27 is inserted into the movable hole 87 of the vane 8. Finally, the front cover 1 and the rear cover 9 are fixed to the base 7. That is, the inner peripheral wall portion 103 and the outer peripheral wall portion 102 of the front cover 1 are fixed to the inner peripheral edge and the outer peripheral edge of the through hole of the base 7. In addition, the edge portion 902 of the rear cover 9 is fixed to the outer peripheral edge of the base 7.

[0049] After the completion of the vane driving device 11, the rear surfaces of the exposed portions of the four metal members 70 of the vane driving device 11 on the +Y side and the Y side are soldered or soldered and bonded to the front surface of the receiving portion 17 of the lens driving device 12.

[0050] Here, the two straight portions of the coil 40 and the pole faces of the magnet 41 face each other. For example, assume the +Z-side pole face of the +X-side magnet 41, the +X-side pole face is magnetized to the N pole, and the -X-side pole face is magnetized to the S pole. Assume the coil 40 on the Y-side in the +X-side of the front-side coil substrate 2, the current flows in the clockwise direction. In the two straight portions of this coil 40, electromagnetic force is generated in the -X direction, and becomes the thrust in the clockwise direction. Assume the coil 40 on the +Y-side in the +X-side of the front-side coil substrate 2, the current flows in the counterclockwise direction. In the two straight portions of this coil 40, electromagnetic force is generated in the +X direction, and becomes the thrust in the clockwise direction. By flowing the current in the same direction through the coil 40 at the same position of the rear-side coil substrate 5, the same direction electromagnetic force is generated, and the same direction thrust is obtained.

[0051] When the current is supplied to the coil 40 as described above, the thrust in the axial direction around the center axis O is generated by the electromagnetic force generated by the coil 40 and the magnet 41. By this thrust, the movable ring 3 rotates with respect to the base 7. Along with this rotation, the movable pin 37 of the movable ring 3 moves within the long hole 27 of the base 7 and the movable hole 87 of the vane 8, and the vane 8 rotates around the shaft of the fixed pin 28 embedded in the fixed hole 88. By the rotation of the four vanes 8, the size of the opening surrounded by the inner periphery of the four vanes 8 changes, and the amount of light from the subject passing through the lens body 15 to the image sensor 16 is controlled. Thus, when the supply of the current to the coil 40 is stopped, the movable ring 3 returns to the original position by the elastic force of the plate spring 6, the positions of the four vanes 8 also return to the original positions, and the opening also returns to the original position.

[0052] The above is the details of the present embodiment. The vane driving device 11 in the present embodiment defines the center axis O, and includes: a plurality of vanes 8 disposed around the center axis O; two coil groups disposed around the center axis O and separated in the direction of the center axis, each of the two coil groups having at least two coils 40 with the direction of the center axis as the winding axis direction; and a magnet 41 disposed between the two coil groups with the magnetization surface facing the two coil groups, the coil 40 and the magnet 41 generating electromagnetic force in the circumferential direction of the circle centered on the center axis O to drive the vane. The electromagnetic force can be generated by the two coil groups disposed on both sides of the magnet 41. Thus, a vane driving device 11 with high spatial efficiency of electromagnetic force generation can be provided.

[0053] Further, in the above-described embodiment, one magnet 41, two coils 40 included in the front-side coil substrate 2 and facing the magnet 41, and two coils 40 included in the rear-side coil substrate 5 and facing the magnet 41 are explained as one group. However, for example, one magnet 41, one coil 40 included in the front-side coil substrate 2 and facing the magnet 41, and one coil 40 included in the rear-side coil substrate 5 and facing the magnet 41 can be set as one group. The number of coils 40 or the number of magnetic poles of the plate surface facing the coils 40 in the magnet 41 can be different for each group. Further, the number of groups of the magnet 41 and the coil 40 can be set to two groups, three groups, or five groups or more.

[0054] Further, in the above-described embodiment, the movable ring 3 can be fixed with the magnet 41, and the front-side coil substrate 2 and the rear-side coil substrate 5 can be fixed at the fixed portion. Further, for example, the magnet 41 can be provided at the front side of the front-side coil substrate 2, and a coil substrate having the coil 40 can be provided at the front side thereof. Each coil 40 can be provided with a straight portion extending in the radial direction. The magnet 41 can be composed of two magnet pieces individually magnetized and facing in opposite directions.

[0055] Explanation of Symbols

[0056] 1 front cover; 2 front-side coil substrate; 3 movable ring; 4 FPC; 5 rear-side coil substrate; 6 plate spring; 7 base; 8 blade; 9 rear cover; 11 blade driving device; 12 lens driving device; 13 camera device; 15 lens body; 16 image sensor; 17 receiving portion; 19 smartphone; 21, 51 wiring portion; 27 long hole; 28 fixing pin; 37 movable pin; 40 coil; 41 magnet; 60 support member; 61 inner edge portion; 62 outer edge portion; 63 wrist portion; 70 metal member; 87 movable hole; 88 fixed hole; 101 front-side wall portion; 102 outer peripheral wall portion; 103 inner peripheral wall portion; 306 gap; 366 hole; 370, 371, 741, 902 table portion; 406, 406, 407 wiring portion; 706 column portion; 901 bottom surface portion; 902 edge portion.

Claims

1. A vane driving device characterized by comprising: a center axis defined, a plurality of vanes disposed around the center axis, two coil groups disposed around the center axis, separated in the direction of the center axis, each of the two coil groups having at least two coils with the direction of the center axis as a winding axis direction, and a magnet disposed between the two coil groups with a magnetization surface facing the two coil groups, the coils and the magnet generating an electromagnetic force in a circumferential direction of a circle centered on the center axis to drive the vanes.

2. The vane driving device according to claim 1, characterized in that the magnet extends sandwiching a prescribed radius orthogonal to the center axis in a direction orthogonal to the radius, different poles from each other being side by side in the direction of the radius, each coil group has two coils disposed sandwiching the radius and facing each pole, the two coils each have two straight line portions extending in a direction orthogonal to the prescribed radius, one of the two straight line portions facing one of the poles, the other of the two straight line portions facing the other of the poles.

3. The vane driving device according to claim 1, characterized by comprising an FPC having a width in the direction of the center axis and extending in a circumferential direction, the two coil groups being electrically connected via the FPC.

4. The vane driving device according to claim 3, characterized by further comprising a base, a movable ring supported so as to be rotatable around the center axis with respect to the base, and a plate spring linking the base and the movable ring to support the movable ring, the coil groups being fixed to the front side and the rear side of the movable ring, the FPC being disposed outside the movable ring.

5. The vane driving device according to claim 4, characterized in that the plate spring electrically connected to the FPC is electrically connected to a metal member embedded in the base, the FPC being electrically connected to the coil groups at the front end edge and the rear end edge.

6. The vane driving device according to claim 5, characterized in that the base has a through hole in a circular ring shape, a column portion rising together with a metal member from a peripheral edge portion surrounding the through hole, a hole is provided in the movable ring, for the plate spring, an inner edge portion is electrically connected to the metal member, and an outer edge portion is electrically connected to the FPC via the hole.

7. The vane driving device according to claim 1, characterized by comprising a fixed portion and a movable ring, the movable ring being supported so as to be rotatable around the center axis with respect to the fixed portion, the vanes being driven by the rotation, one of the two coil groups and the magnet being disposed in the fixed portion, the other being disposed in the movable ring. The vane driving device according to any one of claims 1 to 7 is provided. The camera device according to claim 8 is provided. ​ 8. A camera device, characterized by ​ 9. An electronic device, comprising: ​

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