Lens driving device, camera device, and electronic equipment

Abstract

The present invention provides a lens driving device. The lens driving device (1) is rectangular in shape and can obtain sufficient driving force to drive a large lens body, and comprises: a fixed part; a movable part, which has a holding part for holding the lens body (6) and moves relative to the fixed part along the optical axis of the lens body (6); four coils (30) which are wound around a direction perpendicular to the optical axis and are arranged on one of the fixed part or the movable part; and four magnets (80) which are arranged on the other of the fixed part or the movable part relative to each coil (30). The four coils (30) are arranged at intervals of 90 degrees around the optical axis, and the thickness of the winding axis of each coil (30) is equal to that of the coils (30) facing each other, and different from that of the coils (30) adjacent to each other. The present invention also provides a camera device and an electronic device.

Description

Technical Field

[0001] The present invention relates to a lens driving device, a camera device and an electronic device used in electronic devices such as a smart phone. Background Art

[0002] The voice coil type lens driving device is provided with coils and magnets on the movable part holding the lens body and the fixed part holding the movable part, and uses the electromagnetic force generated between the coil and the magnet to drive the movable part relative to the fixed part. As documents that disclose the technology related to this lens driving device, there are patent documents 1 and 2. The lens driving device of patent document 1 is used to store a leaf spring, a magnet, a coil base, a washer and a conductive spring in a frame body that combines a square-shaped yoke and a base. The lens driving device is provided with four magnets on the inner side of the four sides of the yoke, and two protrusions with a shape that is thin at the base and thick on the outside are provided on the four side surfaces of the coil base, and four coils are wound around the four side protrusions. The lens driving device of patent document 2 is used to store a lens holding part, a lens barrel part, a spring and a driving part composed of a magnet and a coil in a frame body that combines a square-shaped shell and a substrate. The lens driving device is provided with two magnets on two opposing surfaces in the lens holding part, and two coils are provided at the matching position outside the two magnets in the lens barrel part.

[0003] [Prior art literature]

[0004] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2008-268404A

[0006] [Patent Document 2] Japanese Patent Application Publication No. 2008-111873A Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] However, in this camera device, the frame must be rectangular. However, in the case of the technology of Patent Document 1, there are paired magnet coils along the four sides in the frame, so it is difficult to make it rectangular. In addition, in the case of the technology of Patent Document 2, the number of pairs of magnets and coils in the frame is only 2 pairs, so it is difficult to obtain a large driving force and it is impossible to carry a large lens.

[0009] The present invention has been made in view of the above problems, and an object of the present invention is to provide a lens driving device which has a rectangular shape and can obtain a sufficient driving force to drive a large lens body.

[0010]

Methods for solving the problem

[0011] In order to solve the above-mentioned problems, a lens driving device as a preferred embodiment of the present invention is characterized in that it comprises: a fixed part; a movable part, which has a holding part for holding the lens body and moves along the optical axis of the lens body relative to the fixed part; four coils, which are wound around a direction orthogonal to the optical axis and are arranged on one of the fixed part or the movable part; and four magnets, which are opposite to each coil and are arranged on the other of the fixed part or the movable part, and the four coils are arranged at 90 degrees around the optical axis, and the thickness of the winding axis of each coil is equal to that of the coils facing each other and different from that of the coils adjacent to each other.

[0012] In this aspect, a Hall IC may be provided on the air-core portion of one of the four coils.

[0013] Furthermore, a balancing member may be provided on the air-core portion of the other coil facing the one coil.

[0014] Furthermore, the fixing portion may include a base that supports the carrier via four rear springs, and the four rear springs may be respectively disposed between the carrier and the base to form an electric circuit from the outside to the Hall IC.

[0015] Alternatively, the movable portion may include: a carrier having two pairs of side surfaces facing each other with the holding portion sandwiched therebetween; and an FPC provided to surround the two pairs of side surfaces, wherein the coil is provided outside a portion of the FPC surrounding the side surfaces.

[0016] A camera device according to another preferred embodiment of the present invention is characterized by including the above-mentioned lens driving device.

[0017] Another preferred embodiment of the present invention provides an electronic device comprising the above-mentioned camera device.

[0018] [Effects of the invention]

[0019] The lens driving device of the present invention comprises: a fixed part; a movable part, which has a holding part for holding a lens body and moves relative to the fixed part along the optical axis of the lens body; four coils, which are wound around a direction orthogonal to the optical axis and are arranged on one of the fixed part or the movable part; and four magnets, which are arranged on the other of the fixed part or the movable part relative to each coil. Thus, the four coils are arranged at 90 degrees with the optical axis as the axis, and the thickness of the coils in the winding axis direction is equal to that of the coils facing each other and different to that of the coils adjacent to each other. Therefore, it is possible to provide a lens driving device that is rectangular in shape and has sufficient driving force to drive a large lens body. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view of a smartphone 100 equipped with a camera device 2 including a lens driving device 1 according to one embodiment of the present invention.

[0021] Figure 2 yes Figure 1 A stereoscopic view of the lens driving device 1.

[0022] Figure 3 It is decomposition Figure 2 A stereoscopic view of the lens driving device 1.

[0023] Figure 4 Yes means Figure 2 3D diagram of the carrier 60, FPC 50, coil 30 and Hall IC 40 of the lens driving device 1.

[0024] Figure 5 Observed from the +Z side Figure 4 .

[0025] Figure 6 yes Figure 2 A-A' line cross-section diagram.

[0026] Figure 7 yes Figure 2 BB' line cross-section diagram. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 As shown, a camera device 2 including a lens driving device 1 according to an embodiment of the present invention is accommodated in a housing of a smartphone 100 .

[0028] The camera device 2 includes a lens body 6 , an image sensor 9 that converts light incident through the lens body 6 into an image signal, and a lens driving device 1 that holds the lens body 6 and the image sensor 9 and drives the lens body 6 .

[0029] Here, hereinafter, the optical axis of the lens body 6 is appropriately referred to as the Z direction, a direction orthogonal to the Z direction is appropriately referred to as the X direction, and a direction orthogonal to both the Z direction and the X direction is appropriately referred to as the Y direction. In addition, when viewed from the lens body 6, the object side is sometimes referred to as the front side, and the opposite side (image sensor 9 side) is sometimes referred to as the rear side. The front side corresponds to the +Z side, and the rear side corresponds to the -Z side.

[0030] like Figure 2 as well as Figure 3As shown, the lens driving device 1 includes a cover 10, a front spring 20, four coils 30, a Hall IC 40, a balance component 41, an FPC (Flexible printed circuits) 50, a carrier 60, four rear springs 70, four magnets 80, and a base 90. Among these parts, the fixed part includes the cover 10, the magnet 80, and the base 90. The movable part that moves along the optical axis of the lens body 6 relative to the fixed part includes the coil 30, the Hall IC 40, the balance component 41, the FPC 50, and the carrier 60, which are integrated.

[0031] The cover 10 has a front plate 16 and four side plates 17 extending from the four sides of the front plate 16 along the Z side. A magnet 80 is fixed to the inner surface of the side plate 17. The magnet 80 is formed by overlapping and pasting two magnets whose magnetization directions in the plate surface direction are reversed in the front and rear sides in the Z direction in the Z direction. For example, the front side in the Z direction of the inner surface of the magnet 80 is magnetized to the S pole, and the rear side in the Z direction is magnetized to the N pole.

[0032] The lower end of the side plate 17 of the cover 10 is fixed to the peripheral edge of the base 90. In the space surrounded by the cover 10 and the base 90, the movable part is accommodated inside the four magnets 80.

[0033] The carrier 60 has an octagonal shape after chamfering the four corners of the quadrilateral when viewed from the Z direction. A through hole 61 is provided at the center of the carrier 60 as a holding portion for holding the lens body 6. The carrier 60 has two pairs of side surfaces 64 corresponding to the four sides and two pairs of diagonal surfaces 65 corresponding to the four corners, and the two pairs of side surfaces 64 are opposite to each other along the X direction and the Y direction.

[0034] The FPC 50 has an outer shape bent along the seven surfaces of the carrier 60 except for one corner surface 65. The FPC 50 is provided with two pairs of side plate portions 54 respectively facing each other in the X direction and the Y direction and three corner plate portions 55 sandwiched between the adjacent side plate portions 54, and surrounds the two pairs of side surfaces 64 of the carrier 60. The inner surfaces of the side plate portions 54 and the corner plate portions 55 of the FPC 50 are fixed to the side surfaces 64 and the corner surfaces 65 of the carrier 60.

[0035] The coils 30 are fixed to the outer surfaces of the four side plates 54 of the FPC 50. The coils 30 on the outer surfaces of the side plates 54 facing in the X direction are wound around the X direction. The coils 30 on the outer surfaces of the side plates 54 facing in the Y direction are wound around the Y direction. The four coils 30 are respectively arranged so that the front side portions face the front side portions of the corresponding magnets 80, and the rear side portions face the rear side portions of the corresponding magnets 80. Thus, when current flows through each coil 30, an electromagnetic force in the Z direction is generated in each coil.

[0036] like Figure 5As shown, four pairs of coils 30 and magnets 80 are arranged at 90 degrees with the optical axis as the axis. The thickness of each coil 30 in the winding axial direction is equal to that of coils 30 facing each other, and different from that of coils 30 adjacent to each other. The thickness of two coils 30 facing each other in the X direction is thinner than that of two coils 30 facing each other in the Y direction. In order to reduce the thickness, the number of turns can be reduced, but even if the number of turns is the same, the number of axial turns can be reduced or the number of radial turns can be increased, and the coil wire can be made thinner. In addition, these methods can also be combined.

[0037] like Figure 4 as well as Figure 6 As shown, a Hall IC 40 is provided in the hollow core portion of the +X side coil 30 of the two coils 30 facing each other in the X direction. The Hall IC 40 faces the plate surface of the magnet 80 on the +X side. The Hall IC 40 has 6 gaskets. The 6 gaskets are respectively connected to the six electrodes (land) of the side plate portion 54 on the +X side of the FPC 50. Among them, the two electrodes are electrically connected to the two ends of the four coils 30 connected in series, and the same current flows through the four coils 30. The two electrodes can also be electrically connected to each end of the four coils 30 connected in parallel. A balancing component 41 is provided in the hollow core portion of the coil 30 on the -X side. The balancing component 41 is used to obtain a balance with the Hall IC 40.

[0038] like Figure 6 as well as Figure 7 As shown, a front spring 20 is disposed between the front plate 16 of the cover 10 and the carrier 60, and four rear springs 70 are disposed between the base 90 and the carrier 60. The movable portion is elastically supported by the front spring 20 and the rear spring 70. The front spring 20 has an inner ring-shaped inner portion 21 and four arm portions 22 protruding from the inner portion 21 toward the outside. The inner portion 21 is fixed to the periphery of the through hole 61 on the front surface of the carrier 60. The arm portions 22 are fixed to the four corners of the front plate 16 of the cover 10.

[0039] The four rear springs 70 have an arc-shaped inner portion 71 and an arm portion 72 protruding from the inner portion 71 toward the outside. The inner portion 71 is fixed to the periphery of the through hole 61 on the rear surface of the carrier 60. The arm portion 72 is fixed to the four corners of the base 90. The inner end portions of the four rear springs 70 are respectively connected to the remaining four electrodes of the six electrodes of the aforementioned FPC 50. The outer end portions of the four rear springs 70 are respectively connected to the external substrate. The four rear springs 70 respectively constitute a part of the circuit that reaches the pad of the Hall IC 40 from the external substrate through the wiring in the FPC 50.

[0040] The Hall IC 40 detects the relative position of the magnet 80 , that is, the position of the carrier 60 and / or the lens body 6 relative to the fixing portion, by detecting the magnetic field of the magnet 80 from the +X side.

[0041] The above are the structural details of the present embodiment. The lens driving device 1 of the present embodiment includes a fixed portion, a movable portion, four coils 30 and four magnets 80. The movable portion has a holding portion for holding the lens body 6, and moves along the optical axis of the lens body 6 relative to the fixed portion. The four coils 30 are arranged on the movable portion with a direction perpendicular to the optical axis as an axis, and the four magnets 80 are arranged on the fixed portion opposite to each coil 30. Thus, the four coils 30 are arranged with the optical axis as an axis at intervals of 90 degrees, and the thickness of the winding axis of each coil 30 is equal to that of the coils 30 facing each other, and different from that of the coils 30 adjacent to each other. Thus, a lens driving device 1 having a rectangular shape and having sufficient driving force to drive a large lens body 6 can be provided.

[0042] In the above embodiment, the Hall IC 40 may be provided on the hollow portion of one of the two coils 30 facing each other in the Y direction, and the balancing member 41 may be provided on the hollow portion of the other coil 30. Alternatively, the balancing member 41 may not be provided.

[0043] In the above-described embodiment, the front side in the Z direction of the inner surface of the magnet 80 may be set as the N pole, and the rear side in the Z direction may be set as the S pole.

[0044] In the above-described embodiment, the coil 30 and the Hall IC 40 may be provided on the fixed portion side together with the FPC 50 , and the magnet 80 may be provided on the movable portion side.

[0045] In addition, at least four springs of the front spring 20 and the rear spring 70 are provided, wherein the four springs respectively constitute a part of the circuit. For example, two front springs 20 and two rear springs 70 may be provided to constitute a part of the circuit. In addition, four front springs 20 and one rear spring 70 may be provided, and the four front springs 20 respectively constitute a part of the circuit. In the case where the front spring 20 forms a part of the circuit, for example, a vertical portion may be provided at the four corners of the base 90, a conductive portion passing through an external substrate may be formed inside the vertical portion, and the wrist portion 72 of the front spring 20 may be fixed on the front side of the vertical portion and electrically connected to the conductive portion.

[0046]

Explanation of symbols

[0047] 1 lens driving device; 2 camera device; 6 lens body; 9 image sensor; 10 cover; 16 front plate; 17 side plate; 20 front spring; 21 inner side; 22 wrist; 30 coil; 40 Hall IC; 41 balance member; 50 FPC; 54 side plate; 55 angle plate; 60 carrier; 61 through hole; 64 side surface; 65 angle surface; 70 rear spring; 71 inner side; 72 wrist; 80 magnet; 90 base; 100 smart phone.

Claims

1. A lens driving device, characterized in that: have: Fixed part; The movable part has a holding part for holding the lens body and moves along the optical axis of the lens body relative to the fixed part; four coils, which are wound around a direction perpendicular to the optical axis and are arranged on one of the fixed part or the movable part; and Four magnets, which are opposite to the coils, are arranged on the other of the fixed part or the movable part, The four coils are arranged at intervals of 90 degrees around the optical axis, and the thickness of each coil in the winding axial direction is equal to that of coils facing each other and different to that of coils adjacent to each other.

2. The lens driving device according to claim 1, characterized in that: A Hall IC is provided in the air core portion of one of the four coils.

3. The lens driving device according to claim 2, characterized in that: A balancing member is provided in the air-core portion of the other coil facing the one coil.

4. The lens driving device according to claim 2, characterized in that: The movable part is elastically supported by at least four springs. The four springs of the at least four springs respectively constitute a part of a circuit from the outside to the Hall IC.

5. The lens driving device according to any one of claims 1 to 4, characterized in that: The activity unit has: A carrier having two pairs of side surfaces sandwiching the holding portion and facing each other; and The FPC is configured to surround the two pairs of side surfaces. The coil is provided outside a portion of the FPC surrounding the side surface.

6. A camera device, characterized in that: A lens driving device according to any one of claims 1 to 5.

7. An electronic device, characterized in that: A camera device according to claim 6.

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