JP4613290B2 - Lens drive device - Google Patents

Description

  The present invention relates to a lens driving device that is used in a portable small camera or the like and drives a lens in an optical axis direction.

  Patent Document 1 discloses that a lens support is supported on a frame by a front spring and a rear spring, and the lens support is moved in the optical axis direction by electromagnetic force of a coil. In this lens driving device, a cap projecting from the front surface of the lens support is provided, and the inner peripheral end of the front spring is fixed to the lens support with the cap.

  And in the technique of patent document 1, it is trying to protect the front-end | tip of a lens support body in the part which the cap protruded ahead rather than the front surface of the flame | frame.

JP 2004-280031 A

  However, since the cap protrudes in front of the front surface of the lens support, there is a disadvantage in that the size in the optical axis direction of the entire lens driving device increases accordingly.

  In addition, since the cap fixes the inner peripheral end of the front spring to the lens support, the outer peripheral end of the front spring or the arm portion between the inner peripheral end and the outer peripheral end of the front spring. There is a problem that the appearance is impaired due to exposure.

  Therefore, an object of the present invention is to provide a lens driving device that can reduce the dimension in the optical axis direction and has a good appearance.

  According to the first aspect of the present invention, there is provided a frame in which the magnet and the yoke are fixed, a lens support disposed on the inner peripheral side of the frame and in which the coil is fixed, and the lens support with respect to the frame in the optical axis direction. A lens driving device that includes a front spring and a rear spring that are biased to the side, and a cover, and moves the lens support in the optical axis direction of the lens with respect to the frame by electromagnetic force generated by energizing the coil; The front spring has an inner peripheral end fixed to the front end of the lens support and an outer peripheral end fixed to the front inner periphery of the frame. The lens support is moved forward in the optical axis direction by energizing the coil. At the most moved position, the front edge of the lens support is approximately the same as or behind the front of the frame, the cover covers the front spring, and the front is approximately flush with the front of the frame. Characterized in that the outer peripheral portion to the frame is fixed with an adhesive.

  According to a second aspect of the present invention, in the first aspect of the present invention, the front spring is provided with a conductive wire connecting portion to which a conductive wire is connected, and the front spring is moved to the front as the lens support moves. The contact prevention hole which prevents the contact with a conducting-wire connection part when moving to is characterized by the above-mentioned.

  The invention described in claim 3 is characterized in that, in the invention described in claim 2, the cover is made of metal, and a resin sealing material is attached to the front surface.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the outer peripheral portion of the cover is provided with a joint projecting radially outward, and the front surface of the frame is provided. A concave portion that fits into the joint portion is provided, and the joint portion is bonded and fixed to the concave portion.

  According to the first aspect of the present invention, the front end of the lens support is substantially the same as the front of the frame at the position where the lens support is most moved forward in the optical axis direction by energizing the coil. Since the front surface of the cover is substantially flush with the front surface of the frame, the cover does not protrude forward from the front surface of the frame, and the size in the optical axis direction of the lens driving device can be reduced.

  In addition, the front surface of the frame and the front surface of the cover are substantially flush with each other, and the front spring is hidden by the cover, so the appearance is good.

  When the cap is bonded to the lens support, the adhesive may flow to the arm part of the front spring (the part between the outer peripheral end and the inner peripheral end), which may impair the function of the spring. In the present invention, since the cover is bonded to the frame, the bonding surface can be widened, the adhesive can be prevented from flowing to the arm portion side of the front spring, and the degree of freedom of bonding is high.

  According to the second aspect of the present invention, the effect of the first aspect can be obtained, and when the conductive wire is connected to the front surface of the front spring by solder, adhesive or the like, the conductive wire connecting portion is raised. Yes, there is a risk that the lead wire connecting portion may come into contact with the cover covering the front surface of the front spring when the lens support moves forward, but since a contact prevention hole is formed, such a contact can be prevented with a simple configuration. .

  According to the invention described in claim 3, since the function and effect described in claim 2 can be obtained and the cover is made of metal, the thickness of the cover can be reduced while obtaining a predetermined strength. In addition, since a resin sealing material is attached to the front surface of the cover, it is possible to conceal the metallic luster of the cover and finish processing such as painting of the cover is unnecessary. Furthermore, since the anti-contact hole of the cover can be closed with a sealing material, the inside cannot be seen from the anti-contact hole, and the appearance is good.

  According to the invention described in claim 4, the function and effect described in any one of claims 1 to 3 can be obtained, and the joint portion of the cover is fitted into the recess on the front surface of the frame when the cover is assembled. Therefore, the cover can be easily positioned. Since the concave portion is formed on the front surface of the frame and the joint portion is fitted, the joint portion can be prevented from protruding forward from the front surface of the frame.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a part of the lens driving device shown in FIG. 4 with a part cut away and excluding the lens. FIG. 2 is a perspective view showing the lens driving device shown in FIG. 3 is an exploded perspective view of the lens driving device shown in FIG. 4, and FIG. 4 is a perspective view of the lens driving device according to the present embodiment.

  A lens driving device 1 according to the present embodiment is a lens driving device for an autofocus small camera incorporated in a mobile phone.

  The lens driving device 1 includes a substantially cylindrical yoke 3, a frame 5 to which the yoke 3 is fixed, a lens support 7 disposed on the inner peripheral side of the yoke 3, a front spring 9, and a rear spring 11. A base 23 and a cover 24, and the frame 5 is fitted to the base 23 to fix the yoke 3 together with the base 23.

  The yoke 3 has a substantially U-shaped cross section, and a magnet 13 is disposed inside the U-shape, and a coil 15 is disposed on the inner peripheral side of the magnet 13 inside the U-shape. The magnet 13 is fixed to the base 23 via the rear spacer 17. The coil 15 is fixed to the outer peripheral portion 7 a of the lens support 7, and the outer peripheral portion 7 a of the lens support 7 enters the inside of the yoke 3, and the outer peripheral portion 7 a of the lens support 7 is the U-shaped gap of the yoke 3. Is supposed to move.

  The lens support 7 has a substantially cylindrical shape, and a lens 20 is accommodated therein. The lens support 7 is attached to the inner peripheral side of the yoke 3 so as to be movable along the optical axis by a front spring 9 and a rear spring 11. Yes.

  The front spring 9 is a substantially annular leaf spring, and has an inner peripheral end 9 a and an outer peripheral end 9 b. The inner peripheral end 9 a is fixed to the front end 7 b of the lens support 7. The outer peripheral end 9b is sandwiched and fixed between the yoke 3 and the frame 5, and a front spacer 21 is interposed between the outer peripheral end 9b and the yoke 3.

  The front spring 9 is provided with an arm portion 9c between the inner peripheral end portion 9a and the outer peripheral end portion 9b. The arm portion 9c causes the inner peripheral end portion 9a to be connected to the outer peripheral end portion 9b. And urged in the direction of the optical axis.

  The rear spring 11 has substantially the same shape as the front spring 9 and is a substantially annular leaf spring. The inner end 11a of the rear spring 11 is fixed to the rear end 7a of the lens support 7 and the outer end 11b is fixed between the base 23b of the base 23 and the rear spacer 17. An arm portion 11c is provided between the inner peripheral end portion 11a and the outer peripheral end portion 11b.

  The front spring 9 and the rear spring 11 are flat in a natural state before assembly (a state in which no load is applied), but after assembly, the inner peripheral side end portions 9a and 11a are the outer peripheral side end portions, respectively. It is attached in a deformed state so as to be located behind 9b and 11b. Thereby, the urging | biasing force which always turned inner peripheral side edge part 9a, 11a to back (base 23 side) acts with the restoring force (urging | biasing force) of a spring.

  Then, the front end 7b of the lens support 7 is substantially the same as the front surface 5c of the frame 5 or located behind the front surface 5a at the position where the lens support 7 is most moved forward in the optical axis direction by energization of the coil 15. It is like that.

  Further, the front spring 9 is provided with a conductor connecting portion 9d on the front surface, and the conductor connected to the front spring 9 is connected to the coil 15 or a terminal.

  The cover 24 is made of metal and has a substantially annular shape. The cover 24 is attached to the front surface 5c of the frame 5 and covers the front spring 9 attached to the frame 5 and the lens support 7.

  The cover 24 is provided with joint portions 25 that protrude outward in the radial direction on the outer periphery. In the present embodiment, the joint portions 25 are provided at three substantially equal intervals. Further, the cover 24 is formed with a contact prevention hole 32 for preventing the lead wire connecting portion 9c of the front spring 9 from coming into contact with the cover 24 when it moves to the front side along with the movement of the lens support 7.

  A resin sealing material 28 is adhered to the front surface 24a of the cover 24, covers the front surface 24a of the cover 24 with a resin material, and closes the conflict prevention hole 32.

  The frame 5 is provided with a concave portion 30 in which the joint portion 25 of the cover 24 is fitted on the front surface 5 c of the inner peripheral portion, the joint portion 25 of the cover 24 is fitted in the concave portion 30, and the joint portion 25 is bonded to the concave portion 30. It is adhered with an agent.

  The front surface 24 a of the cover 24 and the front surface of the sealing material 28 are substantially flush with the front surface 5 c of the frame 5.

  Next, operations and effects of the lens driving device 1 according to the present invention will be described.

  In the lens driving device 1, when the coil 15 is energized, the lens support 7 moves forward in the optical axis direction with respect to the yoke 3 by electromagnetic force generated by energizing the coil 15 to adjust the focal length of the lens.

  According to the driving apparatus 1 according to the present embodiment, the front end 7b of the lens support 7 is substantially the same as the front surface 5c of the frame 5 at the position where the lens support 7 is most moved to the front side in the optical axis direction. The same is located on the rear side, and the cover 24 has the front surface 24 a substantially flush with the front surface 5 c of the frame 5, so that the cover 24 does not protrude forward from the front surface 5 c of the frame 5, and thus in the lens driving device 1. The dimension in the optical axis direction can be reduced and the apparatus can be miniaturized.

  Further, the front surface 5c of the frame 5 and the front surface 24a of the cover 24 are substantially flush with each other, and the front spring 9 is hidden by the cover 24, so that the appearance is good.

  When the cover 24 is bonded to the lens support 7, the adhesive may flow to the arm portion 9c of the front spring 9 and impair the function of the spring. However, in this embodiment, the cover 24 is attached to the front surface 5c of the frame 5. Since it is bonded, the bonding surface can be widened, the adhesive does not flow to the arm 9c side of the front spring 9, and the front surface 5c of the frame 5 can be widened, so the degree of freedom of the bonding portion Is expensive.

  A portion 9d connected by soldering a conductive wire to the front surface of the front spring 9 can be swelled, and when the lens support 7 moves forward, it may come into contact (contact) with the back surface of the cover 24. Since the anti-collision hole 32 is formed, such an anti-collision can be prevented and the structure is simple because only the hole is formed.

  Since the cover 24 is made of metal, the thickness of the cover 24 can be reduced while obtaining a predetermined strength. Further, since the resin sealing material 28 is attached to the front surface 24a of the cover 24, the metallic luster of the cover 24 is concealed and finishing processing such as painting of the cover 24 is unnecessary. Furthermore, since the anti-contact hole 32 of the cover 24 is closed by the sealing material 28, the front spring 9 cannot be seen from the anti-contact hole 32, and the appearance is good.

  When the cover 24 is assembled to the frame 5, the joint portion 25 provided on the cover 24 is fitted into the recess 30 formed on the front surface 5 c of the frame 5, so that the cover can be easily positioned. Since the concave portion 30 is formed on the front surface 5c of the frame 5, it is possible to prevent the joining portion 25 and the adhesion portion from rising, and it is possible to prevent the joining portion 25 from protruding forward from the front surface 5c.

  In particular, in the present embodiment, the lens support 7 is sandwiched between the front spring 9 and the rear spring 11, and the lens support 7 is urged toward the base 5 so as to prevent the lens support 7 from shaking or impacting. Because it suppresses the movement, it can relieve shock and has excellent impact resistance.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

  For example, in the first and second aspects of the invention, the sealing material 28 may not be provided on the front surface 28 a of the cover 24.

FIG. 5 is a perspective view showing a part of the lens driving device shown in FIG. FIG. 2 is a perspective view showing the lens driving device shown in FIG. It is a disassembled perspective view of the lens drive device shown in FIG. It is a perspective view of the lens drive device concerning this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens drive device 3 Yoke 5 Frame 5c Front surface 7 Lens support body 9 Front side spring 11 Rear side spring 13 Magnet 15 Coil 24 Cover 24a Front surface 25 Joint part 28 Sealing material 30 Recessed part 32 Contact prevention hole

Claims (4)

  A frame having a magnet and a yoke fixed thereto, a lens support disposed on the inner peripheral side of the frame and having a coil fixed thereto, a front spring and a rear for urging the lens support toward the optical axis rear side with respect to the frame A lens driving device that includes a side spring and a cover, and moves the lens support in the direction of the optical axis of the lens with respect to the frame by electromagnetic force generated by energizing the coil. The lens support is fixed to the front end of the lens support and the outer peripheral end is fixed to the front inner periphery of the frame, and the lens support is moved to the front in the optical axis direction by energizing the coil. The front end is the same as the front of the frame or located behind the front, the cover covers the front spring, and the outer periphery is bonded to the frame so that the front is substantially flush with the front of the frame In a lens driving device which is characterized in that it is fixed.   The front spring has a conductive wire connecting portion for connecting a conductive wire, and the cover has a collision prevention hole for preventing a conflict with the conductive wire connecting portion when the front spring moves forward as the lens support moves. The lens driving device according to claim 1, wherein the lens driving device is formed.   The lens driving device according to claim 2, wherein the cover is made of metal, and a resin sealing material is attached to the front surface. The outer periphery of the cover is provided with a joint projecting outward in the radial direction, the front surface of the frame is provided with a recess that fits into the joint, and the joint is adhesively fixed to the recess. The lens driving device according to any one of claims 1 to 3.

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