Blade driving device, camera device, and electronic device

Abstract

This invention provides a blade drive device with high spatial efficiency generated by electromagnetic force. In the blade drive device (11), a central axis O is defined, and it includes: a plurality of blades (8) arranged around the central axis O; and a plurality of groups, each group having at least one coil (40) and a magnet (41), arranged at intervals along the circumference of a circle centered on the central axis O. The winding axis of the coil (40) and the normal direction of the opposing surface of the magnet (41) facing the coil (40) are as a whole oriented towards the radial direction centered on the central axis O. When viewed from the central axis, the magnetic poles formed on the opposing surface flip at positions corresponding to the center of the coil, and each group generates an electromagnetic force along the circumferential direction of the circle to drive the blades (8). This invention also provides a camera device and an electronic device.

Description

Technical Field

[0001] This invention relates to blade drive devices, camera devices, and electronic devices used in smartphones and other electronic devices. Background Technology

[0002] Various techniques for adjusting the amount of light entering a lens body using blades in sliding camera devices have been proposed. Patent Document 1 discloses a camera module with three blades arranged around the entrance aperture, driving these three blades to change the amount of light entering the lens body. This camera module has three drive coils arranged on an FPC (Flexible Printed Circuits) on the bottom surface of the housing holding the blades, and three drive magnets arranged on a movable ring opposite the housing. The blades are moved by rotating the movable ring around the optical axis using the electromagnetic force generated by the drive coils and drive magnets. Patent Document 2 discloses an aperture mechanism with two roughly L-shaped blades, called "blades," arranged around the entrance aperture, driving these two blades to change the amount of light entering the lens body. This aperture mechanism has three coils arranged on an FPC on the bottom surface of the base, and three permanent magnets arranged on a rotating ring on the upper side of the base. The blades are moved by rotating the ring around the optical axis using the electromagnetic force generated by the coils and permanent magnets.

[0003] Existing technical documents

[0004] Patent documents

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

[0006] Patent Document 2: Korean Patent Publication No. 2018-0105970A Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, the technology described in Patent Documents 1 and 2 has a structure in which multiple groups are arranged around the entrance hole, wherein each group includes a coil and a magnet, and the face of the magnet opposite the coil is magnetized into two different magnetic poles. The problem is that the spatial efficiency of the electromagnetic force is low.

[0009] The present invention was made in view of this problem, and its object is to provide a blade drive device with high space efficiency generated by electromagnetic force.

[0010] Methods for solving problems

[0011] To address the aforementioned issues, a preferred embodiment of the blade drive device of the present invention is characterized by defining a central axis and comprising: a plurality of blades disposed around the central axis; and a plurality of groups, each group having at least one coil and a magnet, arranged at intervals along the circumference of a circle centered on the central axis, wherein the winding axis of the coil and the normal direction of the opposing surface of the magnet facing the coil are oriented as a whole toward the radial direction centered on the central axis, and when viewed from the central axis, the magnetic poles formed on the opposing surface flip at a position corresponding to the center of the coil, and each group generates an electromagnetic force along the circumference of the circle to drive the blades.

[0012] Alternatively, when viewed from the central axis, at least two of the coils are connected in a straight line and side by side, with the magnetic poles flipped at positions corresponding to the center of each coil.

[0013] Alternatively, when viewed from the central axis, at least two of the coils are connected and side by side along the circumference of the circle, and the magnetic poles flip at positions corresponding to the center of each coil.

[0014] Alternatively, in the parallel direction of the coil, the area of ​​the magnetized portion of one pole located at both ends of the magnet is smaller than the area of ​​the magnetized portion of the other pole located outside the two ends of the magnet.

[0015] Alternatively, in the parallel direction of the coils, the end of the magnet may be located at the position corresponding to the center of the coils at both ends.

[0016] Alternatively, it may have a fixed part and a movable ring, wherein the movable ring is supported so as to be able to rotate about the central axis relative to the fixed part, thereby driving the blade. For the coil and the magnet, one is disposed in the fixed part and the other is disposed in the movable ring.

[0017] As another preferred embodiment of the camera device of the present invention, it is characterized by comprising the above-described blade driving device.

[0018] As another preferred embodiment of the present invention, the electronic device is characterized by comprising the above-described camera device.

[0019] The effects of the invention

[0020] The blade drive device of the present invention is characterized by defining a central axis and comprising: a plurality of blades disposed around the central axis; and a plurality of groups, each group having at least one coil and a magnet, arranged at intervals along the circumference of a circle centered on the central axis. The winding axis of the coil and the normal direction of the opposing surface of the magnet facing the coil are oriented as a whole toward a radial direction centered on the central axis. When viewed from the central axis, the magnetic poles formed on the opposing surface flip at a position corresponding to the center of the coil. Each group generates an electromagnetic force along the circumference of the circle to drive the blades. A portion along the central axis of the coil can be used efficiently. Thus, a blade drive device with high spatial efficiency in generating electromagnetic force can be provided. Attached Figure Description

[0021] Figure 1 This is a front view of a smartphone 19 equipped with a camera device 13, including a blade drive device 11 as an embodiment of the present invention.

[0022] Figure 2 yes Figure 1 A perspective view of the blade drive device 11.

[0023] Figure 3 yes Figure 2 An exploded perspective view of the blade drive device 11.

[0024] Figure 4 From Figure 2 The image with the front cover 1 removed. Detailed Implementation

[0025] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 As shown, a camera device 13, including a blade drive device 11 as one embodiment of the present invention, is housed in a smartphone 19.

[0026] 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.

[0027] 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.

[0028] The lens drive device 12 has a lens carrier that holds 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 central axis is the same as the Z direction. In addition, the central axis is also in 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.

[0029] like Figure 3 As shown, the blade drive device 11 has a front cover 1, a movable ring 3, four magnetic yokes 31, an FPC 4, 12 coils 40, four plate springs 6, four magnets 41, a base 7, four blades 8, and a rear cover 9. Among them, the front cover 1, the magnets 41, the base 7, and the rear cover 9 constitute a fixed part that does not move relative to the lens drive device 12.

[0030] 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 toward the Z side, and the front cover 1 is annular when viewed from the central axis.

[0031] The movable ring 3 is approximately circular in shape with a width at the front and rear. On the +X, -X, +Y, and -Y sides of the inner surface of the movable ring 3, there are grooves 344 that are recessed outwards and pass through the front and rear, with the bottom of the grooves 344 being flat. Three protrusions 304 are provided in each groove 344. The three protrusions 304 on the +X and -X sides are separated and arranged side-by-side along the Y direction. The three protrusions 304 on the +Y and -Y sides are separated and arranged side-by-side along the X direction. At the rear edge of the +X, -X, +Y, and -Y sides of the movable ring 3, there are platforms 370 that protrude rearwards, and each platform 370 also has a movable pin 37 that protrudes rearwards. Slits 306 extending forward and backward are provided on the +X+Y, +XY, -X+Y, and -XY sides of the movable ring 3.

[0032] The magnetic yoke 31 is a magnetic plate in the shape of a rectangle. The magnetic yoke 31 has a rectangular hole 314 corresponding to the protrusion 304.

[0033] The FPC4 has a shape obtained by cutting off a portion of the +X+Y side of a circular ring with a width at both ends. The FPC4 has a rectangular hole 404 corresponding to the protrusion 304. Three coils 40 are fixed to the +X, -X, +Y, and -Y sides of the inner surface of the FPC4, respectively, corresponding to the hole 404. The three coils 40 on the +X and -X sides are separated and arranged side-by-side along the Y direction, wound around the X-axis. The three coils 40 on the +Y and -Y sides are separated and arranged side-by-side along the X direction, wound around the Y-axis. A slit 406 extending along the front and back is provided on the +XY, -X+Y, and -XY sides of the FPC4.

[0034] The leaf spring 6 has an inner edge 61, an outer edge 62, and a wrist 63 that elastically connects them. The wrist 63 is constructed by a linear, tortuous elastic member.

[0035] Magnets 41 are mounted on base 7 and located on the +X, -X, +Y, and -Y sides. Each magnet 41 is formed by attaching four magnetic plates 411 and 412 in a cuboid shape. For the magnets 41 on the +X and -X sides, the magnetic plates 411 and 412 are arranged side-by-side along the Y direction and have a magnetized surface in the X direction. For the magnets 41 on the +Y and -Y sides, the magnetic plates 411 and 412 are arranged side-by-side in the X direction and have a magnetized surface in the Y direction. The two central magnetic plates 411 of the magnet 41 are square when viewed from the plate surface. The two end magnetic plates 412 are rectangular in shape, with a width equal to half the width of the magnetic plates 411 in the side-by-side direction. The magnetic plates 411 and 412 of the magnet 41 are magnetized such that the magnetic poles of adjacent magnetic plates 411 and 412 in the plate surface direction are opposite magnetic poles. Therefore, the area of ​​the magnetized portion of one magnetic pole located at both ends of the magnet 41 is smaller than the area of ​​the magnetized portion of the other magnetic pole located outside the two ends of the magnet 41.

[0036] The base 7 is in the shape of an annular plate. Four metal components 70 are embedded in the base 7, surrounding a through hole in its center. One end of the two metal components 70 on the +Y side rises outward from the outer edge of the base 7 on the +Y side in a stepped manner, and one end of the two metal components 70 on the -Y side rises outward from the outer edge of the base 7 on the -Y side in a stepped manner. The other end of the metal components 70 rises together with the column portion 706 from the periphery of the through hole surrounding the base 7.

[0037] Two platforms 741 are provided at intervals on the +X, -X, +Y, and -Y sides of the inner periphery surrounding the through hole of the base 7. The surfaces facing the outer periphery of the two platforms 741 are each part of the same plane. A column 706 rises from the periphery surrounding the through hole between adjacent platforms 741. An elongated hole 27 and a fixing pin 28 are provided on the outer periphery of the base 7 near the +X, -X, +Y, and -Y sides, respectively. The elongated hole 27 and the fixing pin 28 are positioned close to the tangent direction of the circle, with the elongated hole 27 extending along the tangent direction of the circumference. The fixing pin 28 extends rearward from the rear surface of the base 7.

[0038] The blade 8 is a flat plate, with four identical blades 8 arranged at 90-degree intervals to form an opening in the center. A movable hole 87 and a fixed hole 88 are provided at the protrusions extending from the outer edge of the blade 8. The movable hole 87 extends along the midline direction of the radial direction and the tangential direction of the circumference, and the fixed hole 88 is circular.

[0039] The rear cover 9 has an annular bottom portion 901 and an edge portion 902 protruding from its outer periphery toward the +Z side.

[0040] The blade drive unit 11 is manufactured in the following manner.

[0041] On the outer peripheral surface of the base 7, which is manufactured by pre-embedding the metal component 70, a magnet 41 is fixed. Additionally, a yoke 31 is fixed in the groove 344 of the movable ring 3, and an FPC 4 is fixed inside it. A protrusion 304 of the movable ring 3 is inserted into the hole 314 of the yoke 31 and the hole 404 of the FPC 4. Furthermore, the gap 306 of the movable ring 3 and the gap 406 of the FPC 4 are aligned. Next, a coil 40 is mounted to the FPC 4 by inserting the protrusion 304 into the central hole, thus establishing a fixed electrical connection.

[0042] Next, the outer edge 62 of the leaf spring 6 is fixed in the gap 306 of the movable ring 3, and electrically connected to the FPC4 at the gap 406. Thus, the inner edge 61 of the leaf spring 6 is fixed and electrically connected to the metal part 70 of the base 7, which stands together with the column 706. Therefore, the movable ring 3, which carries the coil 40, the yoke 31, and the FPC4, is supported on the column 706 of the base 7 via the leaf spring 6. Furthermore, the magnet 41 and the coil 40 face each other. Additionally, the movable pin 37 of the movable ring 3 is inserted into the elongated hole 27 of the solid plate 7.

[0043] Next, the blade 8 is installed on the base 7. The blade 8 is installed by inserting the fixing pin 28 of the base 7 into the fixing hole 88, and by inserting the movable pin 37 of the movable ring 3, which extends further rearward from the elongated hole 27, into the movable hole 87 of the blade 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 and outer peripheral edges of the through hole in the base 7. Additionally, the edge portion 902 of the rear cover 9 is fixed to the outer peripheral edge of the base 7.

[0044] After the blade drive device 11 is completed, the rear surfaces of the exposed portions of the four metal parts 70 of the blade drive device 11 on the +Y and -Y sides are welded or soldered to the front surface of the receiving part 17 of the lens drive device 12.

[0045] On the +X, -X, +Y, and -Y sides, magnets 41 and three coils 40 form groups respectively. In each group, the magnetic plates 411 and 412 constituting magnet 41 are arranged side-by-side in a straight line when viewed from the central axis. Similarly, in each group, coils 40 are arranged side-by-side in a straight line when viewed from the central axis. Magnets 41 and coils 40 in each group are parallel and opposite to each other. In the side-by-side direction of the magnetic plates 411 and 412 in magnet 41, the boundaries of each magnetic plate 411 and 412, i.e., the dividing lines of the magnetic poles, are located at positions corresponding to the center of each coil 40. That is, the magnetic poles flip at these positions.

[0046] When current is supplied to coil 40, the electromagnetic force generated by coil 40 and magnet 41 creates an axial thrust around the central axis O. This thrust causes movable ring 3 to rotate relative to base 7. Accompanying this rotation, movable pin 37 of movable ring 3 moves within the elongated hole 27 of base 7 and the movable hole 87 of blade 8. Blade 8 rotates about the axis of fixed pin 28 embedded in fixed hole 88. The rotation of the four blades 8 changes the size of the opening surrounded by the inner circumference of the four blades 8, controlling the amount of light reaching the image sensor 16 from the subject through lens body 15. Therefore, when current is stopped from supplying coil 40, the elastic force of plate spring 6 returns movable ring 3 to its original position, the four blades 8 to their original positions, and the openings to their original positions.

[0047] The above are the details of this embodiment. The blade drive device 11 of this embodiment defines a central axis O and includes: a plurality of blades 8 disposed around the central axis O; and a plurality of groups, each group having at least one coil 40 and a magnet 41, arranged at intervals along the circumference of a circle centered on the central axis O. The winding axis of the coil 40 and the normal direction of the opposing surface of the magnet 41 facing the coil 40 are as a whole oriented toward the radial direction centered on the central axis O. When viewed from the central axis, the magnetic poles formed on the opposing surface flip at positions corresponding to the center of the coil. Each group generates an electromagnetic force along the circumference of the circle to drive the blades 8. The portion extending along the central axis of the coil 40 can be used efficiently. Therefore, a blade drive device 11 with high spatial efficiency in generating electromagnetic force can be provided.

[0048] Furthermore, in the above embodiments, in one group, the magnet 41 can be configured as two magnetic plates 412, facing one coil 40. Alternatively, the magnet 41 can be configured as one magnetic plate 411, facing two coils 40. In this case, in the side-by-side direction of the coils 40, the ends of the magnet 41 form the minimum combination of positions corresponding to the center of the coils 40 at both ends. Additionally, more than three coils 40 can be used in one group. Furthermore, the number of coils 40 or the number of magnetic poles on the plates of the magnet 41 facing the coils 40 can vary for each group. Additionally, the number of groups of magnets 41 and coils 40 can be two, three, or five or more.

[0049] Alternatively, in the above embodiment, a magnet 41 may be arranged on the movable ring 3, and a coil 40 may be arranged on the fixed plate 7. Alternatively, the coil 40 may be arranged on the outer periphery, and the magnet 41 on the inner periphery. Furthermore, in each group, the magnetic pieces 411 and 412 of the magnet 41 and the coil 40 may be connected and arranged side-by-side along the circumference of the circle. Alternatively, the magnet 41 may not use individual magnetic pieces 411 and 412, but only have its magnetization direction reversed.

[0050] Symbol Explanation

[0051] 1 Front cover; 3 Movable ring; 4 FPC; 6 Leaf spring; 7 Base; 8 Blade; 9 Rear cover; 11 Blade drive device; 12 Lens drive device; 13 Camera device; 15 Lens body; 16 Image sensor; 17 Receiving part; 19 Smartphone; 27 Elongated hole; 28 Fixing pin; 31 Magnetic yoke; 37 Movable pin; 40 Coil; 41 Magnet; 61 Inner edge; 62 Outer edge; 63 Wrist; 70 Metal part; 87 Movable hole; 88 Fixing hole; 101 Front side wall; 102 Outer peripheral wall; 103 Inner peripheral wall; 304 Protrusion; 306 406 Gap; 31 44 404 Hole; 344 Groove; 370 741 Platform; 411, 412 Magnet plates; 706 Post; 901 Bottom surface; 902 Edge.

Claims

1. A blade drive device, characterized in that, Define a central axis and have the following characteristics: Multiple blades are arranged around the central shaft; and Multiple groups, each having at least one coil and one magnet, are arranged at intervals along the circumference of a circle centered on the central axis. In each of the aforementioned groups, the winding axis of the coil and the normal direction of the opposing surface of the magnet facing the coil, as a whole, are oriented in a radial direction centered on the central axis. When viewed from the central axis, the magnetic poles formed on the opposing surfaces flip at positions corresponding to the center of the coil. Each of the groups generates an electromagnetic force along the circumference of the circle to drive the blade.

2. The blade drive device according to claim 1, characterized in that, When viewed from the central axis, at least two of the coils are connected in a straight line and side by side, and the magnetic poles are flipped at positions corresponding to the center of each coil.

3. The blade drive device according to claim 1, characterized in that, When viewed from the central axis, at least two of the coils are connected and side by side along the circumference of the circle, and the magnetic poles flip at positions corresponding to the center of each coil.

4. The blade drive device according to claim 2 or 3, characterized in that, In the parallel direction of the coil, the area of ​​the portion of one magnetic pole located at both ends of the magnet that is magnetized is smaller than the area of ​​the portion of one magnetic pole located outside the two ends of the magnet that is magnetized.

5. The blade drive device according to claim 2 or 3, characterized in that, In the parallel direction of the coils, the end of the magnet is located at the position corresponding to the center of the coils at both ends.

6. The blade drive device according to claim 1, characterized in that, It has a fixed part and a movable ring. The movable ring is supported so that it can rotate about the central axis relative to the fixed part, and the blade is driven by this rotation. The coil and the magnet are respectively disposed in the fixed part and the movable ring.

7. A camera device, characterized in that, The blade drive device is provided with any one of claims 1 to 6.

8. An electronic device, characterized in that, The device comprises the camera apparatus of claim 7.

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