JP2011013702A - Lens driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens driving device capable of preventing the change of motor characteristics and smoothly moving a carrier in the optical axis direction of a lens by preventing the deformation of a spring due to the shift in the horizontal direction and backlash of the carrier.SOLUTION: The lens driving device 1 moves the carrier 7 in the optical axis direction of the lens by an electromagnetic force generated by the energization of a coil 10. The spring 11 is an annular leaf spring in plan view and includes an inner ring 11a attached to the side of the carrier and an outer ring 11b attached to the side of an outer barrel part 5. The carrier 7 has a positioning part 23 provided to project outward in a radial direction and the outside edge 23a of the positioning part 23 is located to face the inner circumference of the outer ring 11b of the spring 11, to perform positioning between the carrier 7 and the outer barrel part 5.

Description

  The present invention relates to a lens driving device.

  Patent Document 1 includes a substantially cylindrical yoke, an outer cylinder portion on which the yoke is mounted, a carrier including a lens, a spring that supports the carrier with respect to the outer cylinder portion, a coil, and a magnet. A lens driving device that moves a carrier in the optical axis direction of a lens by electromagnetic force generated by energizing a coil is disclosed.

JP 2004-280031 A

  However, in the prior art described in Patent Document 1 described above, since the carrier is only supported by the spring on the outer cylinder portion, if a lateral force acts on the carrier, the carrier is displaced and rattled, and the spring There is a problem that the motor may be deformed and the characteristics of the motor may change. In addition, when a lateral force is applied to the carrier and the position of the carrier is shifted, the clearance between the carrier and the outer cylindrical portion cannot be kept constant, and the carrier outer peripheral surface and the outer cylindrical portion inner peripheral surface There is a problem that sliding friction occurs between them and the carrier is difficult to move smoothly in the optical axis direction of the lens.

  It is an object of the present invention to provide a lens driving device that prevents deformation of a spring due to lateral displacement or rattling of a carrier to prevent a change in motor characteristics and that allows the carrier to move smoothly in the optical axis direction of the lens. And

  In order to solve the above-mentioned problem, the invention described in claim 1 includes a substantially cylindrical yoke, an outer cylinder part to which the yoke is attached, a carrier having a lens, and a carrier supported to the outer cylinder part. A lens driving device that includes a spring, a coil, and a magnet, and moves the carrier in the optical axis direction of the lens by electromagnetic force generated by energizing the coil, and the spring is a flat plate spring in plan view, The carrier has an inner ring attached to the carrier side and an outer ring attached to the outer cylinder side, and the carrier is provided with a positioning portion projecting radially outward, and the outer end of the positioning portion is the outer ring of the spring. Positioning between the carrier and the outer cylinder portion is performed by facing the inner periphery of the carrier.

  According to a second aspect of the present invention, in the first aspect of the present invention, the spring includes a plurality of arm portions that connect the inner ring and the outer ring, and the arm portions are provided at intervals in the annular direction of the spring. And a positioning portion is provided between the arm portions.

  According to the first aspect of the invention, since the carrier is provided with the positioning portion for positioning between the carrier and the outer cylinder portion, the movement of the carrier in the lateral direction is regulated by the positioning portion, and the carrier Even if a lateral force is applied to the carrier, the carrier is unlikely to slip or rattle. Therefore, deformation of the spring can be prevented and change in motor characteristics can be prevented.

Since the movement of the carrier in the lateral direction is regulated by the positioning part, the clearance between the carrier and the outer cylinder part can be kept constant, and the sliding friction between the carrier and the inner peripheral surface of the outer cylinder part The carrier can move smoothly in the direction of the optical axis of the lens.
Since the positioning portion is provided on the carrier, the positioning portion can be formed integrally with the carrier, and it is not necessary to use a separate member when providing the positioning portion, and space saving and cost saving can be achieved.

  According to the second aspect of the invention, the same effect as that of the first aspect of the invention can be obtained, and the positioning portion is provided between the arm portions of the spring. In addition, when the spring is molded, the arm portion and the positioning portion can be molded with the same mold, so that the manufacture is easy.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of a lens driving device according to the present embodiment. FIG. 1 (a) is a sectional view showing a relationship between a front spring and an outer cylinder, and (b) is a rear view. FIG. 2 is a plan view of the front spring shown in FIG. 1, FIG. 3 is a plan view of the rear spring shown in FIG. 1, and FIG. 4 is related to the present embodiment. It is a disassembled perspective view of a lens drive device.

  A lens driving device 1 according to this embodiment is incorporated in an autofocus camera of a mobile phone, and includes a substantially cylindrical yoke 3, an outer cylinder portion (base 5 and frame 6) on which the yoke 3 is mounted, a yoke 3, a carrier 7 disposed on the inner circumferential side of the carrier 3, a coil 10 disposed on the outer circumferential side of the carrier 7, and a front spring 9 and a rear spring 11 disposed in the front-rear direction of the carrier 7.

  The yoke 3 has a substantially U-shaped cross section, and a ring-shaped magnet 13 is disposed in the U-shape. The magnet 13 has a ring shape and is divided into four arc-shaped blocks along the circumferential direction.

  The base 5 is made of resin, and includes a substantially flat base portion 5a and base side connection portions 5b provided upright at four corners of the base portion 5a. A yoke is provided on the inner peripheral surface of the base side connection portion 5b. A protrusion 5c that presses and fixes 3 is provided. Further, an engaging portion 24 that engages with the engaged portion 29 of the frame 6 is formed on the outer periphery of the base side connecting portion 5b.

  The frame 6 is made of resin, and includes a substantially flat upper wall portion 6a and frame side connection portions 6b provided upright at four corners of the upper wall portion 6a, and is provided on the inner peripheral surface of the frame side connection portion 6b. Is provided with a protrusion 6c for pressing and fixing the yoke 3. Further, an engaged portion 29 that is engaged with the engaging portion 24 of the base 5 is formed on the outer periphery of the frame side connecting portion 6b. Furthermore, a circular opening 6d is formed in the upper wall 6a, and a cap 15 attached to the carrier 7 is positioned at the position of the opening 6d.

  A predetermined clearance is formed between the inner peripheral surface of the opening 6 d and the outer edge 15 a of the cap 15. When the carrier 7 moves in the optical axis direction, the outer edge 15 a of the cap 15 is not in contact with the inner peripheral surface 6 e of the frame 6.

  The front spring 9 is a substantially annular leaf spring in plan view, and is provided with an inner ring 9a and an outer ring 9b. The inner ring 9a has an annular shape, the outer ring 9b has an annular shape with a radius larger than that of the inner ring 9a, and a plurality of arm portions 9c are provided between the inner ring 9a and the outer ring 9b. ing. The arm portion 9c is provided at an interval in the annular direction of the front spring 9, and a spring side positioning portion (positioning portion) 9d is provided between the arm portions 9c. The spring-side positioning portion 9d is provided so as to project outward in the radial direction, and the outer ring 9b has a shape that is recessed outward in the radial direction by the amount of projection of the spring-side positioning portion 9d. The spring-side positioning portion 9d is formed with a substantially semicircular cutout portion 9f, and a pin for preventing rotation at the time of assembly is inserted into this portion.

  The inner ring 9 a of the front spring 9 is fixed by being sandwiched between the carrier 7 and the cap 15, and the outer ring 9 b is fixed by being sandwiched between the yoke 3 fixed to the base 5 and the frame 6. The outer end 9 e of the spring side positioning portion 9 d faces the inner peripheral surface 6 e of the frame 6. A front spacer 17 is interposed between the outer ring 9 b and the yoke 3.

  The rear spring 11 is a plate spring having a substantially circular shape in plan view, the inner ring 11a is formed in an annular shape, the outer ring 11b is formed in an annular shape having a larger radius than the inner ring 11a, and the inner ring 11a and the outer ring are formed. A plurality of arm portions 11c are provided between 11b and 11b. The arm portions 11 c are provided at intervals in the annular direction of the rear spring 11.

  The inner ring 11 a is fixed to the rear end in the optical axis direction of the carrier 7, and the outer ring 11 b is fixed between the base portion 5 a of the base 5 and the rear spacer 19.

  The front spring 9 and the rear spring 11 have the inner rings 9a and 11a and the outer rings 9b and 11b located on substantially the same plane in a state before assembly (a state where no load is applied to the springs). At the time of assembly, a preload is applied to the spring so that a step is formed between the inner rings 9a and 11a and the outer rings 9b and 11b.

  The carrier 7 has a substantially cylindrical shape, and a lens 12 is fixed therein. Further, the rear end side of the carrier 7 is provided with a flange portion 21, and the flange portion 21 is provided with a carrier side positioning portion (positioning portion) 23 protruding outward in the radial direction. The outer end 23 a of the carrier side positioning portion 23 faces the inner periphery 11 d of the outer ring 11 b of the rear spring 11.

  Next, assembly and operation effects of the lens driving device according to the present embodiment will be described. The lens driving device 1 is assembled by attaching the rear spring 11 to the carrier 7, placing the magnet 13 and the coil 10 fixed to the carrier 7 inside the yoke 3, and placing the rear spacer 19 on the base portion 5 a of the base 5. Assemble through. The inner ring 9 a of the front spring 9 is placed between the front spacer 17 and the yoke 3 and fixed with the cap 15, the frame 6 is attached to the base 5, and the outer ring 9 b of the front spring 9 is attached to the frame 6. Fix it.

  In the state where the front spring 9 is assembled, the outer end 9e of the spring side positioning portion 9d of the inner ring 9a faces the inner peripheral surface 6e of the frame 6, and the lateral movement of the carrier 7 is restricted. Further, in the state in which the rear spring 11 is assembled, the outer end 23a of the carrier side positioning portion 23 of the carrier 7 faces the inner periphery 11d of the outer ring 11b, and the lateral movement of the carrier 7 is restricted. .

  In the present embodiment, since the outer end 9e of the spring side positioning portion 9d faces the inner peripheral surface 6e of the frame 6 and the lateral movement of the carrier 7 is restricted, a lateral force acts on the carrier 7. However, the carrier 7 is unlikely to be displaced or rattled. Therefore, deformation of the arm portion 9c of the front spring 9 and the arm portion 11c of the rear spring 11 can be prevented, and a change in motor characteristics can be prevented.

  Further, since the lateral movement of the carrier 7 is restricted, the clearance between the carrier 7 and the frame 6 (the portion indicated by reference numeral 25 in FIG. 1A), the clearance between the carrier 7 and the yoke 3 ( 1), the clearance between the yoke 3 and the coil 10 (the portion indicated by reference numeral 29 in FIG. 1), and the clearance between the magnet 13 and the coil 10 (indicated by reference numeral 31 in FIG. 1). Part) can be kept constant, and the carrier 7 can move smoothly in the optical axis direction of the lens 12.

  Since the spring-side positioning portion 9d is provided in the inner ring 9a of the spring, it is not necessary to use a separate member when providing the positioning portion, and space saving and cost saving can be achieved.

  Since the spring side positioning portion 9d is provided between the arm portions 9c of the spring, it is possible to effectively use the space where the spring is vacant, and by taking a large area of the positioning portion 9d, it is possible to prevent a lateral impact. Thus, deformation of the positioning portion 9d can be prevented. Further, when the spring is molded, the arm portion 9c and the spring side positioning portion 9d can be molded with the same mold, so that the manufacture is easy.

  Needless to say, the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the scope of the invention.

  The lens driving device 1 is not limited to a camera related to a mobile phone, but may be used for a digital camera.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view of the lens drive device which concerns on this Embodiment, (a) extracted and shown with a dashed-dotted line is sectional drawing which shows the relationship between a front side spring and an outer cylinder part, (b) is a rear side spring, It is sectional drawing which shows the relationship with an outer cylinder part. It is a top view of the front side spring shown in FIG. It is a top view of the rear side spring shown in FIG. It is a disassembled perspective view of the lens drive device concerning this embodiment.

1 Lens drive device 3 Yoke 5 Base (outer cylinder)
6 Frame (outer cylinder)
7 Carrier 9 Front spring (spring)
9a Inner ring 9b Outer ring 9c Arm 10 Coil 11 Rear spring (spring)
11a Inner ring 11b Outer ring 11c Arm part 12 Lens 13 Magnet 23 Carrier side positioning part

Claims (2)

  A substantially cylindrical yoke, an outer cylinder part to which the yoke is mounted, a carrier having a lens, a spring for supporting the carrier with respect to the outer cylinder part, a coil, and a magnet, are generated by energizing the coil. A lens driving device that moves a carrier in the optical axis direction of the lens by electromagnetic force, and the spring is an annular leaf spring in plan view, and includes an inner ring attached to the carrier side and an outer ring attached to the outer cylinder part side. The carrier is provided with a positioning portion projecting radially outward, and the outer end of the positioning portion is positioned opposite to the inner periphery of the outer ring of the spring, so that the carrier and the outer cylinder portion A lens driving device characterized by positioning between the two.   The spring includes a plurality of arm portions that connect the inner ring and the outer ring, the arm portions are provided at intervals in the annular direction of the spring, and a positioning portion is provided between the arm portions. 2. The lens driving device according to 1.

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