JP4537866B2 - Lens drive device - Google Patents

Description

  The present invention relates to a lens driving device used for a digital camera or the like.

  A lens driving device mounted on a portable device such as a digital camera or a camera-equipped mobile phone includes a moving lens body provided with a lens, and a magnetic driving mechanism for moving the moving lens body linearly along the optical axis of the lens. A lens driving device provided has been proposed (see, for example, Patent Document 1).

Further, a lens driving device has been devised in which the rotor is rotationally driven by a stator, the rotational operation is converted into a linear motion, and the moving lens body is linearly magnetically driven along the optical axis of the lens.
JP-A-10-150759

  In any of these types of lens driving devices, when a stopper mechanism for defining the moving range of the moving lens body in the optical axis direction is provided, a fixed body is provided on the outer peripheral side of the moving lens body 10A as shown in FIG. Since there is no space for disposing the stopper mechanism with respect to 20A, the end portion 28A located on the subject side of the fixed body 20A and the end portion 29A on the opposite side (imaging element side) from the subject side are projected inward. Thus, a contacted portion capable of contacting the one end face and the other end face in the optical axis direction of the moving lens body 10A is formed.

  However, when the stopper mechanism 40A having such a configuration is configured, the light of the lens driving device 1A is disposed by the amount of the contacted portions (end portions 28A and 29A) at positions overlapping the moving lens body 10A in the optical axis direction. There is a problem in that the dimension in the axial direction becomes longer, which hinders the thinning of the lens driving device 1A.

  In view of the above problems, an object of the present invention is to provide a lens driving device that can be thinned even when a stopper mechanism that defines a moving range of the moving lens body in the optical axis direction is provided. is there.

In order to solve the above problems, in the present invention, a moving lens body that is movable in the optical axis direction on a fixed body, a magnetic drive mechanism that moves the lens moving body along the optical axis, and a moving lens body In the lens driving device having a stopper mechanism for defining a moving range in the optical axis direction, the magnetic driving mechanism includes a first magnetic means disposed on the moving lens body side and a position on the outer peripheral side from the moving lens body. A second magnetic means disposed on the fixed body side, and the stopper mechanism is connected to the moving lens body at a position on the outer peripheral side with respect to the second magnetic means and is integrated with the moving lens body. and the outer interlocking part that moves axially is constituted in the fixed body side, the outer peripheral side interlocking part is provided with abutting abutted portion when moved in the optical axis direction, the first magnetic The means is the moving lens The second magnetic means is disposed on one side of the optical axis direction with respect to the magnet, and is disposed on the other side of the optical axis direction. A second stator coil, wherein the outer peripheral side interlocking portion is fixed to an outer peripheral side end of the magnet.

  In the present invention, since the magnetic drive mechanism including the first magnetic means and the second magnetic means is disposed on the outer peripheral side of the moving lens body, a stopper mechanism is provided in the vicinity of the outer peripheral side of the moving lens body. However, in the present invention, an outer peripheral side interlocking portion connected to the moving lens body is provided at a position on the outer peripheral side from the second magnetic means, and the outer peripheral side interlocking portion is integrated with the moving lens body on the fixed body side. A stopper mechanism is provided by providing a contacted portion that contacts when moved in the optical axis direction. For this reason, it is not necessary to dispose a stopper mechanism on the side of the moving lens body in the optical axis direction, so that the lens driving device can be thinned even when the stopper mechanism is provided. Furthermore, since the stroke amount of the moving lens body is set on the outer peripheral side of the lens driving device, the stroke adjustment operation can be performed efficiently in the manufacturing process of the lens driving device.

Further, according to the present invention, the magnet protrudes from the moving lens body to the outer peripheral side, and the stator coil as the second magnetic means is disposed in the optical axis direction with respect to the magnet. An outer peripheral side interlocking portion that moves integrally with the moving lens body can be easily formed at the outer peripheral side position of the magnetic means.

  In this invention, the said outer peripheral side interlocking | linkage part is a cylindrical member attached to the outer peripheral side edge part of the said magnet coaxially with the said moving lens body, The said cylindrical member is a said 1st stator coil and a said 2nd It is preferable to cover the outer peripheral side of the stator coil. If comprised in this way, the outer peripheral side interlocking | linkage part which consists of a cylindrical member can be utilized as a case which covers the outer peripheral side surface of a lens drive device.

  In the present invention, it is preferable that the cylindrical member is formed with a notch for drawing out a power feeding terminal for the first stator coil and the second stator coil to the outer peripheral side. If comprised in this way, even when the outer peripheral side interlocking | linkage part which consists of a cylindrical member is utilized as a case which covers the outer peripheral side surface of a lens drive device, electric power feeding to a stator coil can be performed without trouble.

  In the present invention, the magnetic drive mechanism may be arranged at a center position in the optical axis direction of the moving lens body, but the magnetic drive mechanism has an optical axis as viewed from the center position in the optical axis direction of the movable lens body. You may arrange | position in the position biased to one of the directions. Here, when the magnetic drive mechanism is configured at a position biased toward the subject side in the optical axis direction when viewed from the center position in the optical axis direction of the moving lens body, an empty space can be secured on the side opposite to the subject side, A circuit for the image sensor and a circuit for the stator coil can be arranged. In addition, when the magnetic drive mechanism is configured at a position deviated from the subject side in the optical axis direction when viewed from the center position in the optical axis direction of the moving lens body, an empty space can be secured on the subject side. When an accessory unit such as a shutter mechanism is disposed on the side, the mechanism portion can be disposed in an empty space.

  In the lens driving device according to the present invention, an outer peripheral side interlocking portion connected to the moving lens body is provided at a position on the outer peripheral side from the second magnetic means, and the outer peripheral side interlocking portion is integrated with the moving lens body on the fixed body side. A stopper mechanism is provided by providing a contacted portion that contacts when moved in the optical axis direction. For this reason, it is not necessary to dispose a stopper mechanism on the side of the moving lens body in the optical axis direction, so that the lens driving device can be thinned even when the stopper mechanism is provided. Furthermore, since the stroke amount of the moving lens body is set on the outer peripheral side of the lens driving device, the stroke adjustment operation can be performed efficiently in the manufacturing process of the lens driving device. Therefore, since the working efficiency is improved, the productivity of the lens driving device can be increased, and the cost can be reduced.

  A lens driving device to which the present invention is applied will be described below with reference to the drawings.

(overall structure)
1A, 1B, and 1C are a plan view, a longitudinal sectional view, and a side view of a lens driving device to which the present invention is applied. 1B and 1C, the right side shows the state where the moving lens body has moved to the subject side (closest distance position side), and the left side shows the moving lens body on the image sensor side (infinity). The position has been moved to the position side).

  1A, 1B, and 1C, the lens driving device 1 according to the present embodiment is a digital camera or the like on which an image sensor (not shown) is disposed (one side in the optical axis L direction / infinite). This is for reciprocating the lens system between the far position side) and the subject side (the other side / closest distance position side in the optical axis L direction), and includes three lenses 11, 12, 13 and an aperture 15, A movable lens body 10 having 16 in a cylindrical lens holder 14, a magnetic drive mechanism 30 for driving the movable lens body 10 in the optical axis L direction, and the magnetic drive mechanism 30 and the movable lens body 10 are accommodated. The fixed body 20 is provided. The fixed body 20 includes a base member 21 to which an imaging element or the like is fixed, and a cover member 22 located on the subject side. The base member 21 and the cover member 22 have an outer diameter dimension of the moving lens body. Substantially equal openings 210 and 220 are formed.

  The magnetic drive mechanism 30 includes a ring-shaped magnet 31 (first magnetic means) attached to the outer peripheral side of the moving lens body 10 via a sleeve 15, and one side in the optical axis L direction with respect to the magnet 31. An annular first stator coil 33 (second magnetic means) disposed, an annular first yoke 34 disposed opposite to the magnet 31 with respect to the first stator coil 33, and a magnet An annular second stator coil 35 (second magnetic means) arranged on the other side in the optical axis L direction with respect to 31 and an opposite side of the magnet with respect to the second stator coil 35. And an annular second yoke 36. Here, the magnet 31 is magnetized to different poles on the inner peripheral side and the outer peripheral side.

  Here, the movable lens body 10 and the sleeve 15 are connected via a screw or the like, and the magnet 31 has a flange portion 150 in a state in which the protrusion formed on the inner peripheral side of the magnet 31 is fitted in the groove on the outer peripheral surface of the sleeve 15. It is positioned with and fixed with adhesive. The first stator coil 33 and the first yoke 34 are fixed with an adhesive or the like in an annular recess 211 formed on the upper surface of the base member 21, and the second stator coil 35 and the second yoke 36 are covered with a cover. It is fixed in an annular recess 221 formed on the lower surface of the member 22 with an adhesive or the like.

(Configuration of stopper mechanism)
The lens driving device 1 configured as described above further includes a stopper mechanism 40 that defines a moving range of the moving lens body 10 in the optical axis L direction. In constructing such a stopper mechanism 40, in this embodiment, first, a cylindrical member 41 is fixed coaxially with respect to the moving lens body 10 at the outer peripheral side end of the magnet 31. Is movable in the direction of the optical axis L integrally with the moving lens body 10 at a position on the outer peripheral side from the first stator coil 33 and the second stator coil 35.

  Further, the base member 21 is formed with a cylindrical body 212 on which the inner peripheral surface of the cylindrical member 41 slides, and at the end of the cylindrical body 212 on the image sensor side, the imaging of the cylindrical member 41 is performed. An annular step portion 42 (contacted portion) that defines a moving range of the lens moving body 10 toward the imaging device side by contacting the end portion on the element side is formed. On the other hand, the cover member 22 is formed with a cylindrical body 222 on which the inner peripheral surface of the cylindrical member 41 slides, and an object on the object side of the cylindrical body 222 has a subject of the lens moving body 10. An annular step portion 43 (abutted portion) that defines a moving range to the side is formed.

  Here, the cylindrical member 41 forms a case that covers the outer peripheral side of the first stator coil 33 and the second stator coil 35 and covers the outer peripheral side surface of the lens driving device 1. Further, two power supply terminals 341 and 342 for winding the coil terminal of the first stator coil 33 are formed by using a part of the first yoke 34, and these power supply terminals 341 are formed. , 342 are drawn out from the notches 411, 412 formed in the cylindrical member 41 to the outer peripheral side. Further, two power supply terminals 361 and 362 for winding the coil terminal of the second stator coil 35 are formed by using a part of the second yoke 36, and these power supply terminals 361 are formed. , 362 are also drawn out from the notches 413, 414 formed in the cylindrical member 41 to the outer peripheral side. Therefore, even when the cylindrical member 41 is used as a case, power can be supplied to the first stator coil 33 and the second stator coil 35 without hindrance.

(Operation)
In the lens driving device 1 configured in this manner, the energizing condition to the stator coils 33 and 35 of the magnetic driving mechanism 30 is controlled at the time of autofocusing, so that the moving lens body 10 is moved to one side and the other side in the optical axis L direction. And the movable lens body 10 is held at these positions.

  First, in the state shown on the right side of FIG. 1B, the moving lens body 10 moves to the subject side, and the subject-side end of the cylindrical member 41 contacts the subject-side annular step 43 of the fixed body 20. The position is at a close distance, and this state is maintained by a magnetic attractive force acting between the magnet 31 and the second yoke 36.

  When a predetermined current is passed through the stator coils 33 and 35 from this state, a thrust toward the image pickup device acts on the moving lens body 10, and the moving lens body 10 picks up an image as shown on the left side of FIG. Moving to the element side, the end of the cylindrical member 41 on the image sensor side becomes an infinite position where it contacts the annular step 42 on the image sensor side of the fixed body 20. Such a state is maintained by a magnetic attractive force acting between the magnet 31 and the first yoke 34.

  Further, when a predetermined current is passed through the stator coils 33 and 35 from the state shown on the left side of FIG. 1B, thrust toward the subject side acts on the moving lens body 10 and is shown on the right side of FIG. As described above, the moving lens body 10 moves to the subject side, and the end of the cylindrical member 41 on the subject side comes to a close distance position where it contacts the annular step 43 on the subject side of the fixed body 20. Such a state is maintained by a magnetic attractive force acting between the magnet 31 and the second yoke 36.

(Main effects of this form)
As described above, in the lens driving device 1 of the present embodiment, the magnetic driving mechanism 30 is disposed on the outer peripheral side of the moving lens body 10, and thus a stopper mechanism cannot be formed near the outer peripheral side of the moving lens body 10. A cylindrical member 41 connected to the moving lens body 10 is provided at the outer peripheral side position of the coils 33, 35, etc., and the cylindrical member 41 is moved integrally with the moving lens body 10 in the optical axis L direction on the fixed body 20 side. The stopper mechanism 40 is configured by providing annular step portions 42 and 43 (contacted portions) that come into contact with each other. For this reason, since it is not necessary to arrange a stopper mechanism at a position overlapping the moving lens body 10 in the optical axis L direction, the lens driving device 1 can be thinned even when the stopper mechanism 40 is provided.

  In the present embodiment, the magnet 31 protrudes from the moving lens body 10 toward the outer peripheral side, and the stator coils 33 and 36 are disposed in the optical axis L direction with respect to the magnet 31. The cylindrical member 41 that moves integrally with the moving lens body 10 can be easily disposed at the outer peripheral side position.

  Furthermore, since the stroke amount of the moving lens body 10 is set on the outer peripheral side of the lens driving device 1, the stroke adjustment work can be performed efficiently in the manufacturing process of the lens driving device 1. Therefore, since the working efficiency is improved, the productivity of the lens driving device 1 can be increased, and the cost can be reduced.

(Other embodiments)
In the above embodiment, the magnetic drive mechanism 30 is disposed at the center position in the optical axis L direction of the moving lens body 10, but the magnetic drive mechanism 30 is moved to the moving lens as shown in FIGS. The body 10 may be disposed at a position biased to one side in the optical axis L direction when viewed from the center position in the optical axis L direction. For example, as shown in FIG. 2A, when the magnetic drive mechanism 30 and the stopper mechanism 40 are configured at positions that are biased toward the image pickup element when viewed from the center position in the optical axis L direction of the moving lens body 10, Since the empty space 2 can be secured on the side, when an accessory unit such as a shutter mechanism is arranged on the subject side, the mechanism portion can be arranged in the empty space 2. In addition, as shown in FIG. 2B, when the magnetic drive mechanism 30 and the stopper mechanism 40 are configured to be biased toward the subject when viewed from the center position in the optical axis L direction of the moving lens body 10, the subject side Since the empty space 3 can be secured on the opposite side, a circuit board for the image sensor and a circuit board for the stator coils 33 and 35 can be arranged.

In the above embodiment, the present invention is applied to a lens driving device having a magnetic driving mechanism that linearly moves the moving lens body along the optical axis L. However, the rotor is rotationally driven by a stator, and the rotational operation is linear. The present invention may be applied to a lens driving device that converts the moving lens body linearly and magnetically along the optical axis L of the lens .

(A), (b), (c) is the top view of the lens drive device to which this invention is applied, a longitudinal cross-sectional view, and a side view. (A), (b) is explanatory drawing which shows the modification of the lens drive device to which this invention is applied. It is explanatory drawing which shows the conventional lens drive device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens drive device 10 Moving lens body 15 Sleeve 20 Fixed body 30 Magnetic drive mechanism 31 Magnet (1st magnetic means)
33 First stator coil (second magnetic means)
34 First yoke 35 Second stator coil (second magnetic means)
36 Second yoke 40 Stopper mechanism 41 Cylindrical member (outer peripheral interlocking portion)
42, 43 Annular step (contacted part)

Claims (4)

A moving lens body movable in the optical axis direction on the fixed body, a magnetic drive mechanism for moving the lens moving body along the optical axis, and a stopper mechanism for defining a moving range of the moving lens body in the optical axis direction; In a lens driving device having
The magnetic drive mechanism includes first magnetic means disposed on the moving lens body side, and second magnetic means disposed on the fixed body side at a position on the outer peripheral side from the moving lens body,
The stopper mechanism is connected to the moving lens body at a position on the outer peripheral side from the second magnetic means, and is configured on the outer peripheral side interlocking portion that moves integrally with the moving lens body in the optical axis direction, and on the fixed body side. A contacted portion that contacts when the outer peripheral side interlocking portion moves in the optical axis direction ,
The first magnetic means is a magnet protruding from the moving lens body to the outer peripheral side,
The second magnetic means includes a first stator coil disposed on one side in the optical axis direction with respect to the magnet, and a second stator coil disposed on the other side in the optical axis direction,
The outer peripheral side interlocking portion is fixed to the outer peripheral side end of the magnet. The outer peripheral side interlocking portion according to claim 1, wherein the outer peripheral side interlocking portion is a cylindrical member attached coaxially with the moving lens body at an outer peripheral side end portion of the magnet.
The cylindrical member covers the outer peripheral side of the first stator coil and the second stator coil. 3. The lens driving device according to claim 2, wherein the cylindrical member is formed with a notch for pulling out a power supply terminal for the first stator coil and the second stator coil to the outer peripheral side. 4. The lens drive according to claim 1, wherein the magnetic drive mechanism is disposed at a position biased to one side in the optical axis direction when viewed from a center position in the optical axis direction of the movable lens body. apparatus.

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