JP2008250190A - Lens drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens drive device capable of minimizing dimension necessary in the direction of an optical axis even if an attachment unit such as a shutter mechanism or a diaphragm mechanism is added. <P>SOLUTION: In the lens drive device 1, a movable lens body 10 and a lens drive mechanism 5 for driving the movable lens body 10 in the direction of an optical axis are incorporated in a fixing body 20. The fixing body 20 incorporates: a plate-like shutter blade 100 switchable from the state in which it is located on the optical paths of lenses 2, 3, and 4 to the state in which it is retracted from the optical paths; and the attachment unit 200 having an optical member drive mechanism 150 for driving the shutter blade 100. The optical member drive mechanism 150 has: a rotor 80 having a rotor magnet 170 in which S-poles and N-poles are alternately disposed in the direction of circumference; and a drive coil 550 passing thought both end faces of the rotor magnet 170 and wound around the circumference of the rotor magnet 170 in the direction of its axis. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  An imaging apparatus mounted on a portable device such as a digital camera includes a moving lens body including a lens and a lens driving mechanism for linearly magnetically driving the moving lens body along the optical axis of the lens. A lens driving device is used.

Such a lens driving device includes a lens moving body and a fixed body mounted on the lens moving body so as to be movable in the lens optical axis direction. The lens moving body is provided with a drive magnet, and the fixed body has a driving coil. And two magnetic pieces (yoke) are proposed (see Patent Document 1).
Japanese Patent Laying-Open No. 2005-37865 (FIG. 1)

  If such a lens driving device is provided with a mechanical shutter mechanism or the like, camera shake when attempting to capture an image with a digital camera can be prevented. In addition, if an aperture mechanism or the like is provided, the function can be enhanced such that a high-quality image can be taken even when sunlight is strong.

  However, if a digital camera or the like is provided with a shutter mechanism or a diaphragm mechanism that is separate from the lens driving device, a large space is required to install these devices in the digital camera. There is a problem of becoming.

  In view of the above-described problems, an object of the present invention is to provide a lens driving device that can keep the dimension in the optical axis direction to a minimum necessary dimension even when an accessory unit such as a shutter mechanism or a diaphragm mechanism is added. There is.

  In order to solve the above problems, the present invention includes a moving lens body that is movable in the optical axis direction, a lens driving mechanism that drives the moving lens body in the optical axis direction, the moving lens body, and the lens driving mechanism. In the lens driving device having the fixed member, the fixed member includes an optical member that is switched between a state of appearing on the optical path of the lens and a state of retracting from the optical path, and an optical member drive that drives the optical member. The optical member driving mechanism is provided with a rotor having a rotor magnet in which S poles and N poles are alternately formed in the circumferential direction, and both end faces of the rotor magnet. A drive coil wound so as to extend in the axial direction along the outer peripheral side surface of the rotor magnet, and the rotation of the rotor is transmitted to the optical member. To.

  In the present invention, “the moving lens body is mounted on the fixed body” means that the moving lens body is mounted directly on the fixed body so as to be movable in the optical axis direction, and the moving lens body is driven by the lens. This also includes the case where it is mounted on a fixed body via a mechanism.

  In the present invention, “the lens driving mechanism and the accessory unit are mounted on the fixed body” means that the lens driving mechanism and the member constituting the accessory unit are directly mounted on the fixed body, as well as the lens. This includes the case where a part of the members constituting the drive mechanism and the accessory unit is mounted on the fixed body via the moving lens body or the lens drive mechanism.

  In the present invention, accessory units such as a shutter mechanism and a diaphragm mechanism are mounted on the fixed body, like the moving lens body and the lens driving mechanism. For this reason, it is not necessary to mount the accessory unit on the digital camera or the mobile phone separately from the lens driving device, so that the size of these devices can be reduced.

  In the present invention, it is preferable that the optical member is supported on the fixed body directly or via another member so as to be rotatable around an axis parallel to the optical axis.

  In the present invention, for example, the optical member includes at least one optical member selected from a shutter plate, a diaphragm plate, a color conversion plate, a neutral density filter plate, an infrared filter plate, and an ultraviolet filter plate. Can be adopted.

  In the present invention, the optical member includes two optical members selected from a shutter plate, a diaphragm plate, a color conversion plate, a neutral density filter plate, an infrared filter plate, and an ultraviolet filter plate, and the optical member driving mechanism. And adopting a configuration including a first optical member driving mechanism for driving one of the two optical members and a second optical component driving mechanism for driving the other optical member. Also good.

  In the present invention, the rotor and the optical member are mechanically connected via a rotation transmission mechanism that transmits the rotation of the rotor to the optical member, and the optical member is rotationally driven via the rotation transmission mechanism. Can be adopted.

  In the present invention, the optical member may be directly connected to the rotor and rotationally driven.

  In the present invention, the accessory unit is disposed on the subject side with respect to the moving lens body, and when the moving lens body is moved to the closest distance position side on the subject side, the accessory unit includes the moving lens body. It is preferable to provide a space into which the subject side end enters. With this configuration, when the moving lens body is moved to a close range position, the distal end portion of the moving lens body enters the space of the attached unit, so even when the attached unit is arranged on the subject side with respect to the moving lens body. The dimension of the lens driving device in the optical axis direction can be short.

  In the present invention, the lens driving mechanism includes a first magnetic means disposed so as to surround the moving lens body, and the first magnetic means and the magnetic driving mechanism on the moving lens body side. A second magnetic means configured to rotate around the optical axis, and a conversion mechanism for converting the rotation of the second magnetic means into a force in which the movable lens body moves linearly along the optical axis direction; It is possible to adopt a configuration comprising If comprised in this way, a lens can be positioned in the desired position between the lens position at the time of close-up photography, and the lens position at the time of normal photography.

  In the present invention, the lens driving mechanism includes the driving coil and a driving magnet that generates a linkage magnetic field in a direction perpendicular to the optical axis direction of the lens with respect to the driving coil. It is preferable that either one of the coils is fixed to the moving lens body, and the other is fixed to the fixed body. If comprised in this way, a lens can be positioned in the desired position between the lens position at the time of close-up photography, and the lens position at the time of normal photography.

  In the present invention, accessory units such as a shutter mechanism and a diaphragm mechanism are mounted on the fixed body, like the moving lens body and the lens driving mechanism. For this reason, it is not necessary to mount the accessory unit on the digital camera or the mobile phone separately from the lens driving device, so that the size of these devices can be reduced.

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

[Embodiment 1]
(overall structure)
FIG. 1 is a cross-sectional view of a lens driving device according to Embodiment 1 of the present invention. In addition, in this drawing, a principal part is shown with a continuous line, and another structural member is shown with a broken line. 2 is a cross-sectional view of the lens driving device according to Embodiment 1 of the present invention cut along the line XX ′ of FIG. FIG. 3 is an exploded perspective view of the lens driving device according to Embodiment 1 of the present invention.

  As shown in FIGS. 1, 2, and 3, the lens driving device 1 according to the present embodiment is mounted on a camera-equipped mobile phone or the like, and the three lenses 2, 3, 4 are moved along the optical axis L. Is moved in both directions, A direction approaching the image and B direction approaching the side opposite to the subject (image side). Specifically, the lens driving device 1 generally includes a moving lens body 10 that integrally holds three lenses 2, 3, and 4 on a lens barrel 11, and the moving lens body 10 along the optical axis L. And a fixed body 20 on which the lens driving mechanism 5 and the moving lens body 10 are mounted.

  In this embodiment, the fixed body 20 includes a base 21 and a cover 22. In addition to the stator 50 constituting the lens driving mechanism 5, a CCD (imaging device) and the like are mounted on the base 21. Further, a cover 22 is disposed on the subject side so as to sandwich the stator 50 with respect to the base 21, and the cover 22 is fixed to the base 21 with screws (not shown) or the like and bonded and fixed.

  As will be described in detail later, the lens driving device 1 is provided with an accessory unit 2000 including a plate-like shutter blade 100 that can rotate in a direction to open and close an opening O having a center point on the optical axis L. .

(Configuration of lens drive mechanism)
The lens driving mechanism 5 is configured using a stator 50 and a rotating body 8. The stator 50 has two annular drive coils 55 stacked in the direction of the optical axis L, and each of the two drive coils 55 is sandwiched between two annular yokes 51. In this state, in the stator 50, the pole teeth of the two yokes 51 are alternately arranged in the circumferential direction on both the lower stage side and the upper stage side across the spacer 56. Note that a total of four coil terminal wires are drawn from the two drive coils 55, and each of these coil terminal wires is connected to a terminal on a terminal block (not shown). There are six terminals, one of which is connected to the spacer 56 to be grounded.

  Inside the cylindrical stator 50, a cylindrical rotating body 8 is coaxially arranged between the moving lens body 10, and the rotating body 8 includes a cylindrical driving magnet 60 and the driving magnet 60. And a cylindrical resin sleeve 70 fixedly bonded to the outer peripheral surface. On the outer peripheral surface of the drive magnet 60, S poles and N poles are alternately arranged in the circumferential direction, and the drive magnet 60 and the stator 50 constitute a magnetic drive mechanism 6 having a stepping motor structure.

  The sleeve 70 is rotatable around the axis (optical axis L), and when the two drive coils 55 are fed at an appropriate timing, the rotary body 8 is rotated around the optical axis L by the rotational driving force received by the drive magnet 60. Rotate to.

  In the lens driving device 1, the moving lens body 10 includes three lenses 2, 3, 4 and a lens barrel 11 that holds these lenses 2, 3, 4. These are arranged coaxially inside the cylindrical sleeve 7. A female screw 72 is formed on the inner peripheral surface of the sleeve 70, while a male screw 14 is formed on the outer peripheral surface of the lens barrel 11 in the moving lens body 10. It is screwed.

  As shown in FIG. 3, the lens barrel 11 is formed with a plurality of protrusions 11a protruding outward in the direction of the optical axis L, while the fixed body 20 side, for example, the cover 22 has protrusions. A recess 22a into which 11a is fitted is formed. By these projections 11a and recesses 22a, a rotation preventing mechanism that prevents the rotation of the moving lens body 10 when the rotational force of the rotating body 8 is transmitted to the moving lens body 10 via the male screw 14 and the female screw 72. Is configured. Therefore, when the rotating body 8 rotates, the moving lens body 10 moves linearly along the optical axis L without rotating. Thus, a conversion mechanism for moving the moving lens body 10 along the optical axis L by the rotation of the drive magnet 60 is configured. A spring 18 is arranged between the lens barrel 11 and the cover 22, and the spring 18 prevents backlash between the male screw 14 and the female screw 72. In configuring the rotation prevention mechanism, a groove may be formed in the moving lens body 10 and a protrusion may be formed on the fixed member 20.

(Configuration of shutter blade driving device)
1, 2, and 3, the accessory unit 2000 includes a shutter body 1600, an optical member driving mechanism 150, and a top plate 1700 as an upper surface cover. The moving shutter body 1600 includes a shutter blade 100 that opens and closes the opening O, and a base plate 1500 to which the shutter blade 100 is rotatably attached by a fixing pin 1400. Here, openings 1750 and 1550 are formed in the upper base plate 1700 and the base plate 1500 at positions overlapping the opening O.

  In this embodiment, the base plate 1500 is fixed to the cover 22 of the fixed body 20 on the subject side of the moving lens body 10. Protruding stoppers 1900 and 1901 are formed on the base plate 1500, and these stoppers 1900 and 1901 regulate the rotation range of the shutter blade 100.

  Here, a fulcrum hole 101 serving as a fulcrum of rotation is formed in the shutter blade 100, and a fixing pin 1400 is loosely fitted in the fulcrum hole 101, and the fixing pin 1400 is inserted into a fixing hole 1501 formed in the base plate 1500. It is fixed. With such a configuration, the shutter blade 100 is rotatable about its fulcrum hole 101 and is restricted in position in the radial direction. Such stoppers 1900 and 1901 can be formed by embossing or cutting and raising.

  As shown in FIG. 2, the base plate 1500 and the cover 22 are formed with notches 1502 and 225 so that a part of the optical member driving mechanism 150 is arranged. A connecting hole 102 as a connecting portion formed in the optical member driving mechanism 150 is formed at the rear end of the shutter blade 100. The connection hole 102 is formed as a long hole, and is loosely fitted to a pin portion 1300 formed in the lever portion 1000 constituting the optical member driving mechanism 150. The connection hole 102 protrudes from the notch 1502 in the direction of the optical member drive mechanism 150 and can be engaged with the pin 1300.

  In addition, although the pin part 1300 was formed in the lever part 1000, you may employ | adopt the structure which forms a pin part in the shutter blade | wing 100 and provides a connection hole and a notch in the lever part 1000 side. Further, instead of the connecting hole 102, a notch long hole with one end opened may be used.

  The optical member driving mechanism 150 includes a stator 500 and a rotor 80. The rotor 80 includes a shaft 160, a cylindrical rotor magnet 170 attached to the shaft 160, a lever portion 1000 extending from the shaft 160, and A pin portion 1300 is provided as a protruding portion formed on the distal end side of the lever portion 1000. Both ends of the shaft 160 protrude from both end surfaces of the rotor magnet 170, and these protruding portions are rotatably supported by an upper bearing 1100 and a lower bearing 1150 disposed on the upper side and the lower side in FIG. Has been.

  The stator 500 includes a yoke 1200 and an annular drive coil 550 disposed inside the yoke 1200, and the drive coil 550 passes from the upper bearing 1100 and the lower bearing 1150 in the axial direction and is parallel to the shaft 160. It is wound in any direction. For this reason, the drive coil 550 passes through both end faces of the rotor magnet 170 and is wound so as to extend in the axial direction along the outer peripheral side surface of the rotor magnet 170.

  As shown in FIG. 1, the rotor magnet 170 is magnetized in two directions in the circumferential direction, and the polarization plane, that is, the neutral plane of the S pole and the N pole is the length of the axis of the shaft 160 and the lever portion 1000. Along the direction. The rotor magnet 170 and the stator 500 constitute a motor, and the lever portion 1000 rotates around the central axis L ′ of the shaft 160. Therefore, when power is supplied to the drive coil 550, the rotor magnet 170 rotates with respect to the fixed drive coil 550 and the rotor 80 rotates according to Fleming's law.

  Here, a part of the yoke 1200 is notched, and the lever portion 1000 protrudes from between both ends of the notch. For this reason, when the lever portion 1000 swings due to the rotation of the rotor 80, the rotational force of the lever portion 1000 (rotational force of the rotor magnet 170) is transmitted to the shutter blade 100, and the shutter blade 100 opens and closes the opening O. Rotate to. Note that both ends of the yoke 1200 are used as second stoppers 1201 and 1202 for regulating the rotation angle of the shutter blade 100, and the stoppers 1201 and 1202 may be formed by cutting and raising.

  In this embodiment, as shown in FIG. 1, the yoke 1200 has a substantially square planar shape, and protrusions 1203 and 1204 projecting inward are formed at substantially the center of each side. . For this reason, in the region where the protrusion 1203 is formed, the distance between the yoke 1200 and the rotor magnet 170 is narrowed, so that the rotor magnet 170 and the protrusion 1203 are attracted to each other by a magnetic attractive force.

  In the present embodiment, the position of the protrusion 1203 is radially outside the position where the position of the shutter blade 100 is restricted by the stopper 1900. That is, the shutter blade 100 is formed so as to have a force that pushes the stopper 1900 further than the position where the shutter blade 100 contacts the stopper 1900. For this reason, in addition to the magnetic attractive force, a force that the shutter blade 100 presses the stopper 1900 works, so that the shutter blade 100 is supported more stably.

  Similarly, the protrusion 1204 also protrudes toward the inner periphery of the yoke 1200, and the distance from the rotor magnet 170 disposed in the yoke 1200 is reduced. Therefore, the rotor magnet 170 and the protrusion 1204 are separated by a magnetic attractive force. Both are attracting. Further, the position of the protrusion 1204 is radially outward from the position where the shutter blade 100 is restricted by the stopper 1901. That is, the shutter blade 100 is formed so as to have a force that pushes the stopper 1901 further than the position where the shutter blade 100 contacts the stopper 1901. For this reason, in addition to the magnetic attraction force, the shutter blade 100 presses the stopper 1901 so that it is supported more stably.

(Lens drive operation)
In the lens driving device 1 configured as described above, when the two drive coils 55 are energized, the rotating body 8 rotates clockwise (CW) or counterclockwise (CCW). Therefore, the female screw 72 of the sleeve 70, the male screw 14 of the moving lens body 10, and the rotation prevention mechanism are used to move the moving lens body 10 in the direction A or the moving lens body 10 in the direction B away from the subject. To do. Therefore, for example, as shown in FIG. 2, when the moving lens body 10 moves toward the subject, the upper surface 11b of the lens barrel 11 moves to the position indicated by the alternate long and short dash line L11b. Here, an opening 1550 (concave portion) is formed in the base plate 1500, and the upper surface 11 b of the lens barrel 11 (the tip of the moving lens body 10) enters the opening 1550 of the base plate 1500. There is nothing to do.

(Shutter blade drive operation)
Next, the operation at the time of rotation of the shutter blade 100 will be described with reference to FIGS. 1, 4A and 4B. 4A and 4B show how the shutter blade 100 sequentially opens from the state where the opening O is closed as shown in FIG. In the state shown in FIG. 1, the shutter blade 100 is in a state where its base portion is in contact with the first stopper 1901 and is positioned. In addition, the lever portion 1000 that transmits the rotational force of the shutter blade 100 by the attractive force between the rotor magnet 170 and the yoke 1200 constituting the optical member driving mechanism 150 is magnetically applied to the protrusion 1203 formed on the yoke 1200. Sucked by. For this reason, the shutter blade 100 is pressed against the first stopper 1901 and stops, so that the stop position is stabilized. That is, in the state shown in FIG. 1, it is not necessary to pass a current through the drive coil 550 constituting the optical member drive mechanism 150, so that power saving can be achieved.

  In this state, when a current is passed through the drive coil 550 of the optical member drive mechanism 150, the shutter blade 100 rotates, and the direction of rotation is controlled by the direction of the current passed through the drive coil 550. That is, when a current is passed through the drive coil 550, the rotor magnet 170 is rotated in the counterclockwise (CCW) direction in the figure according to Fleming's left-hand rule. As a result, as the rotor magnet 170 rotates, the pin portion 1300 also rotates counterclockwise (CCW), and the movement of the pin portion 1300 causes the shutter blade 100 to move around the fulcrum (fixed pin 1400). ) Direction. As a result, as shown in FIG. 4 (A), the shutter blade 100 is moved approximately half from the opening O, and the opening O is opened approximately half, and as shown in FIG. 4 (B), The shutter blade 100 is completely moved from the opening O. In this state, the shutter blade 100 is in a state where the base is in contact with the first stopper 1900 and positioned. In this state, the lever portion 1000 that transmits the rotational force of the shutter blade 100 by the attractive force between the rotor magnet 170 and the yoke 1200 constituting the optical member driving mechanism 150 is magnetically applied to the protrusion 1204 formed on the yoke 1200. It is sucked by the action. For this reason, since the shutter blade 100 is pressed against the first stopper 1900 and stops, the shutter blade 100 is stabilized. Therefore, in the state shown in FIG. 4B, since it is not necessary to pass a current through the drive coil 550 constituting the optical member drive mechanism 150, power saving can be achieved.

(Main effects of this form)
As described above, in the lens driving device of the present embodiment, the accessory unit 2000 is mounted on the fixed body 20, like the moving lens body 10 and the lens driving mechanism 5. For this reason, it is not necessary to mount the accessory unit 2000 on the digital camera or the mobile phone separately from the lens driving device 1, so that the size of these devices can be reduced.

  In addition, an opening 1550 (concave portion) is formed in the base plate 1500, and the upper surface 11b of the lens barrel 11 (the distal end portion of the moving lens body 10) enters the opening 1550 of the base plate 1500. Even if the accessory unit 2000 is arranged, there is no interference.

  In this embodiment, when the shutter blade 100 abuts against the stoppers 1900 and 1901, the rotor magnet 170 constituting the optical member driving mechanism 150 and the protrusions 1203 and 1204 formed on the yoke 1200 made of a magnetic material. The shutter blade 100 can be held at the stop position by the magnetic attractive force. For this reason, even when the drive coil 550 constituting the optical member drive mechanism 150 is de-energized, the position of the shutter blade 100 can be held by its magnetic action, and power saving can be achieved.

  In the lens driving device 1, the position of the shutter blade 100 can also be regulated by the second stoppers 1201 and 1202 formed on the yoke 1200. Here, the second stoppers 1201 and 1202 are formed on the yoke 1200 constituting the optical member driving mechanism 150. That is, a notch is formed in the yoke 1200 made of a magnetic material, and the rotation range of the shutter blade 100 is controlled by causing the rotation range of the shutter blade 100 to function as the stoppers 1201 and 1202 at both ends of the notch. For this reason, since the configuration can be simplified, the size can be reduced and the production cost can be reduced.

  Further, in the second stoppers 1201 and 1202 as well as the first stoppers 1900 and 1901, the position of the shutter blade 100 constitutes the optical member driving mechanism 150 even when the drive coil 550 is de-energized. The stop position can be held by the magnetic attractive force of the rotor magnet 170 and the protrusions 1203 and 1204, and power saving can be achieved.

[Embodiment 2]
FIG. 5 is a longitudinal sectional view of a lens driving device according to Embodiment 2 of the present invention. FIG. 6 is an exploded perspective view of the lens driving device according to Embodiment 2 of the present invention. FIG. 7 is a plan view of a leaf spring used in the lens driving device according to Embodiment 2 of the present invention.

  In the first embodiment, the lens driving mechanism 5 employs a stepping motor structure. However, as shown in FIG. 5, one of the drive magnet and the drive coil is fixed to the moving lens body, and the other is fixed. A fixed structure may be adopted. For example, in the lens driving device 1 shown in FIGS. 5 and 6, the fixed body 20 includes a base 21, a cover 22, and a cylindrical yoke 16 held between the base 21 and the cover 22. . In this embodiment as well, an accessory unit 2000 including the shutter blade 100 is configured. However, the configuration of the accessory unit 2000 is the same as that of the first embodiment, and thus the description thereof is omitted.

  In this embodiment, in the lens driving mechanism 5, a ring-shaped driving magnet 17 is fixed to the inner peripheral surface of the yoke 16, and the driving magnet 17 protrudes inward from the inner peripheral surface of the yoke 16. The movable lens body 10 includes three lenses 2, 3, 4, a lens barrel 11 that holds these lenses 2, 3, and 4, and a sleeve 15 to which the lens barrel 11 is fixed. In the outer periphery of the sleeve 15, a ring-shaped first drive coil 141 is fixed to the subject side (front side), and a ring-shaped second drive coil 142 is fixed to the image sensor side (rear side). Has been. Here, the first drive coil 141 is positioned on the front side of the drive magnet 17 on the outer peripheral side of the sleeve 15, and the second drive coil 142 is positioned on the rear side of the drive magnet 17 on the outer peripheral side of the sleeve 15. is doing. For this reason, the drive magnet 17 is interposed between the first drive coil 141 and the second drive coil 142 in the direction of the optical axis L. Therefore, the rear end surface of the first drive coil 141 and the front end surface of the drive magnet 17 are opposed to each other, and the front end surface of the second drive coil 142 and the rear end surface of the drive magnet 17 are opposed to each other. The first drive coil 141 and the second drive coil 142 fixed to the sleeve 15 can move relative to the yoke 16 in the direction of the optical axis L together with the moving lens body 20.

  In the lens driving device 1 configured as described above, the driving magnet 17 is magnetized in a direction perpendicular to the direction of the optical axis L, and the magnetic flux emitted from the N pole of the driving magnet 17 is, for example, the sleeve 15, the first one. After passing through one drive coil 141 and the yoke 16, it returns to the drive magnet 17 again. Further, the magnetic flux emitted from the N pole of the drive magnet 17 passes through, for example, the sleeve 15, the second drive coil 142, and the yoke 16 and returns to the drive magnet 17 again. Therefore, a magnetic circuit (magnetic path) is formed by members such as the first drive coil 141, the second drive coil 142, the yoke 16, and the sleeve 15. For this reason, it is preferable to use a magnetic material as the material of the sleeve 15. The sleeve 15 can be removed from the material constituting the magnetic circuit (magnetic path).

  The distance between the opposing surfaces of the first drive coil 141 and the second drive coil 142 is greater than the thickness of the drive magnet 17 in the direction of the optical axis L, and between the drive magnet 17 and the first drive coil 141, and There is a gap in the direction of the optical axis L between the drive magnet 17 and the second drive coil 142, and the movable lens body 10 can move in the direction of the optical axis L within the range of this gap.

  The yoke 16 is formed so that the length in the direction of the optical axis L is longer than the distance between the opposing surfaces of the first drive coil 141 and the second drive coil 142. For this reason, the leakage magnetic flux from the magnetic path formed between the drive magnet 17 and the first drive coil 141 and the magnetic path formed between the drive magnet 17 and the second drive coil 142 is reduced. The linearity between the amount of movement of the sleeve 15 and the current flowing through the first drive coil 141 and the second drive coil 142 can be improved.

  In the lens driving device 1 of the present embodiment, the lens driving mechanism 5 includes a first leaf spring 131 and a second leaf spring that restrict the movement of the sleeve 15 as shown in FIGS. 5, 6, and 7. 132 (regulating means) is provided, and the first and second leaf springs 131 and 132 are held between the cover 22 and the yoke 16 and between the base 19 and the yoke 16. Of these first and second leaf springs 131 and 132, the second leaf spring 132 is engaged with an anti-rotation groove 21a formed in the base 21, as shown in FIG. Thereby, the rotation of the second leaf spring 132 is prevented.

  The second leaf spring 132 is a metal spring through which an electric current flows, and the rear end of the sleeve 15 is placed on the innermost circumferential portion 132a. Further, three terminals 132b for energizing the second drive coil 142 are formed in the circumferential portion 132a, and current can be supplied to the second drive coil 142 through the terminal 132b.

  Although a detailed description is omitted, the first leaf spring 131 is also provided with a terminal for energizing the first drive coil 141, like the second leaf spring 132, and the first leaf spring 131 is connected to the first leaf spring 131 through the terminal. It is possible to pass a current through one drive coil 141. Thereby, the first leaf spring 131 and the second leaf spring 132 can be made to function as energization wiring for the first drive coil 141 and the second drive coil 142, and as a result, the electric circuit of the lens drive device 1. The configuration (circuit wiring) can be facilitated and the entire lens driving device 1 can be reduced in size.

  Referring again to FIG. 5, in this embodiment, a current-carrying wiring 140 for the first drive coil 141 and the second drive coil 142 is provided on the outer peripheral surface of the sleeve 15. Thereby, the current flowing through the first drive coil 141 and the current flowing through the second drive coil 142 can be made equal, and current control is facilitated.

  In the lens driving device 1 having such a configuration, when currents in the same direction are supplied to the first and second driving coils 141 and 142, the first and second driving coils 141 and 142 are directed upward (front side), respectively. You will receive electromagnetic force. As a result, the sleeve 15 to which the first and second drive coils 141 and 142 are fixed starts to move toward the subject side (front side). In the present embodiment, as described above, the energization wiring 140 is provided in the sleeve 15 and the currents flowing through the first and second drive coils 141 and 142 are equalized. The substantially equal electromagnetic force acts on the two drive coils 141 and 142. Further, since the size of the lens driving device 1 is very small (for example, outer diameter is about 10 mm × height is about 5 mm), the magnetic flux passing through the first driving coil 141 and the magnetic flux passing through the second driving coil 142 are different. Think of it as almost equal.

  At this time, elastic forces that restrict the movement of the sleeve 15 are generated between the first leaf spring 131 and the front end of the sleeve 15 and between the second leaf spring 132 and the rear end of the sleeve 15, respectively. . For this reason, when the electromagnetic force that moves the sleeve 15 forward and the elastic force that restricts the movement of the sleeve 15 are balanced, the sleeve 15 stops. In this way, by adjusting the amount of current flowing through the first drive coil 141 and the second drive coil 142 and the elastic force acting on the sleeve 15 by the first leaf spring 131 and the second leaf spring 132, The sleeve 15 (movable lens body 10) can be stopped at a desired position.

  In the present embodiment, since the first and second leaf springs 131 and leaf springs 132 in which a linear relationship is established between the elastic force (stress) and the displacement amount (strain amount) are used, the sleeve 15 is used. Linearity between the amount of movement and the current flowing through the first and second drive coils 141 and 142 can be improved. Also, since two elastic members, the first and second leaf springs 131 and 132, are used, a large balance force is applied in the direction of the optical axis L when the sleeve 15 is stopped. Even if other forces such as centrifugal force are applied in the direction of the axis L, the sleeve 15 can be stopped more stably. Further, in the lens driving device 1, in order to stop the sleeve 15, it is not stopped by colliding with a collision material (buffer material) or the like, but is stopped using a balance between electromagnetic force and elastic force. Therefore, it is possible to prevent the occurrence of a collision sound.

  In this embodiment, a leaf spring is used, but a coil spring may be used. Moreover, in the said form, although two drive coils were used, you may use one drive coil. Conversely, two drive magnets may be used for one drive coil.

  Furthermore, in the above embodiment, the driving magnet and the driving coil are opposed to each other in the direction of the optical axis L. However, the driving coil is fixed to the outer peripheral side of the sleeve 15 and the driving magnet is fixed to the outer peripheral side with respect to the driving coil. You may fix to the yoke 16 so that it may oppose. In the above embodiment, the drive coil and the drive magnet are formed in an annular shape. However, while the drive coil is wound around the sleeve 15, a plurality of drive magnets are wound around the outer periphery of the drive coil. You may arrange | position in the position away in a direction. Furthermore, as long as the interlinkage magnetic field can be generated in the direction orthogonal to the optical axis with respect to the drive coil, the drive magnet is either magnetized in the axial direction or configured radially in and out. May be adopted. Further, the drive magnet of the drive magnet and the drive coil may be fixed to the sleeve 15.

[Embodiment 3]
FIG. 8 is a longitudinal sectional view of a lens driving device according to Embodiment 3 of the present invention. In the above embodiment, a configuration in which the base plate 1500 is fixed to the fixed body 20 is adopted. However, as shown in FIG. 8, the base plate 1500 is fixed to the upper surface of the moving lens body 10 and the shutter is placed on the base plate 1500. You may employ | adopt the structure by which the blade | wing 100 is hold | maintained. With this configuration, when the moving lens body 10 moves to the subject side, the base plate 1500 and the shutter blade 100 also move to the subject side as indicated by alternate long and short dash lines L1500 and L100. Here, the pin portion 1300 is provided long in the optical axis L direction. Therefore, even if the shutter blade 100 moves along the optical axis L direction, the driving force can be transmitted to the shutter blade 100. That is, the length of the pin portion 1300 in the optical axis L direction is formed to be longer than the moving distance of the shutter blade 100 in the optical axis L direction, so that it does not come out even when it moves most in the A direction approaching the subject. It is configured. Other configurations are the same as those of the first and second embodiments, and thus description thereof is omitted.

  In the lens driving device 1 of the present embodiment, a shutter blade 100 as an optical member is attached to the moving lens body 10. However, since the pin portion 1300 is long in the optical axis L direction, the shutter blade 100 is connected to the optical axis L. Even if it moves along the direction, the driving force can be transmitted to the shutter blade 100. Therefore, the shutter blade 100 may have a size corresponding to a certain angle of view from the lenses 2, 3, and 4 provided in the moving lens body 10. In addition, since the distance between the lenses 2, 3, 4 and the shutter blade 100 is constant, the shutter blade 100 may have a minimum size necessary for shielding light. For this reason, since the shielding area of the shutter blade 100 is not increased in accordance with the change in the angle of view, the inertia (inertia) generated in the shutter blade 100 can be reduced. Therefore, the operating speed of the shutter blade 100 can be improved, and power can be saved even when the operating speed of the shutter blade 100 is increased.

  In the lens driving device 1, since the first stoppers 1900 and 1901 described with reference to the first embodiment are formed on the base plate 1500 that moves integrally with the shutter blade 100, the base plate 1500 (moving) Even when the lens body 10) moves in the direction of the optical axis L, the first stoppers 1900 and 1901 can reliably regulate the rotation range of the shutter blades 100. Furthermore, since the first stoppers 1900 and 1901 are provided on the base plate 1500 (the moving lens body 10) together with the shutter blade 100, the configuration can be simplified, so that the size can be reduced and the production cost can be reduced. .

[Embodiment 4]
In the first to third embodiments, the optical member is the shutter blade 100, but it can also be a neutral density filter (ND filter (not shown)). The ND filter is a well-known filter that can reduce only the amount of light with little influence on the color.

[Embodiment 5]
FIGS. 9A and 9B are a plan view and a longitudinal sectional view of an accessory unit configured in the lens driving device according to Embodiment 4 of the present invention. As shown in FIGS. 9A and 9B, a plurality of optical members may be arranged for the lens driving device 1. For example, the shutter blade 100 and the ND filter 900 are provided to be rotatable around the fulcrum hole 101 and the fixing pin 1400, respectively. Further, the pin portion 1300 formed on the lever portion 1000 of the shutter blade driving device is fitted into the connecting hole 102 of the shutter blade 100, and the pin portion 1300 formed on the lever portion 1000 of the ND filter driving device is inserted into the connecting hole 102 of the ND filter 900. Just fit. Further, for example, as shown in FIG. 9B, three ground plates, that is, an upper ground plate 910, a middle ground plate 920, and a ground plate 930 are arranged so as to be stacked, and between the ground plate 930 and the middle ground plate 920. Has a shutter blade 100 and an ND filter 900 between the middle base plate 920 and the upper base plate 930. Also in this case, as shown in FIG. 9A, it is preferable to form the first stoppers 950 and 951 on the base plate 930 to restrict the rotation range of the shutter blade 100, and the middle plate 920 has the first stopper. 1 stoppers 941 and 942 are preferably formed to restrict the rotation range of the ND filter 900.

  When configured in this manner, the light quantity can be adjusted by attaching the ND filter 900 between the middle base plate 920 and the upper base plate 910 so as not to be affected by the lens design in place of the diaphragm blades. Further, since the distance between the ND filter 900 and the lenses 2, 3, 4 does not change, there is no focus on the ND filter surface, so that dust and scratches attached to the ND filter 900 surface are copied. The image is not deteriorated. Moreover, since only the shutter blade 100 or only the ND filter 900 can be provided in accordance with the application of the lens driving device, the weight can be reduced. On the other hand, for high-intensity shooting indoors and outdoors, an ND filter 900 can be provided together with the shutter blade 100 to obtain a desired high-quality image.

[Other embodiments]
In the above embodiment, the rotation of the rotor is transmitted to an optical member such as a shutter blade via a lever mechanism. For example, while a thread is spirally wound around a pair of rotors, this thread is also applied to the rotation center axis of the optical member. The optical member may be rotated by winding it spirally and pulling the yarn by rotating the rotor. Further, the rotation of the rotor may be transmitted to an optical member such as a shutter blade via a cam mechanism.

  Furthermore, an optical member such as a shutter blade may be directly connected to the rotor, and the optical member may be rotated.

  Further, when a plurality of optical members are provided, the combination may be other than the combination of the shutter blade and the ND filter. For example, it is possible to provide two shutter blades 100 and simultaneously open and close the opening. In this case, since the moving distance of the shutter blades per sheet becomes short and the inertia is small, the opening / closing operation of the opening can be performed at a higher speed. Further, an ND filter may be combined with two shutter blades. Further, the optical member may be a diaphragm blade instead of the ND filter 900, or may be combined with a shutter blade and an ND filter. When the diaphragm blades are attached, the light quantity can be adjusted by changing the aperture of the exposure opening. Since the position of the aperture blade on the optical axis is determined by the lens design, the degree of freedom is small. However, in this embodiment, the aperture can be arranged at a predetermined interval without changing the interval between the aperture and the aperture blade. Can be downsized.

  In addition to the shutter plate and the neutral density filter plate (ND filter plate), the optical member includes a diaphragm plate, a color conversion plate for appropriate color conversion, an infrared filter plate for cutting infrared rays, and an ultraviolet filter plate for cutting ultraviolet rays. Etc. may be used.

It is a cross-sectional view of the lens driving device according to the first embodiment of the present invention. It is sectional drawing when the lens drive device which concerns on Embodiment 1 of this invention is cut | disconnected along the XX 'line of FIG. It is a disassembled perspective view of the lens drive device concerning Embodiment 1 of the present invention. (A), (B) is explanatory drawing which shows a mode that the shutter blade opens sequentially from the state which has closed the opening part in the lens drive device which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the lens drive device which concerns on Embodiment 2 of this invention. It is a disassembled perspective view of the lens drive device concerning Embodiment 2 of this invention. It is a top view of the leaf | plate spring used for the lens drive device which concerns on Embodiment 2 of this invention. It is a longitudinal cross-sectional view of the lens drive device which concerns on Embodiment 2 of this invention. (A), (B) is the top view and longitudinal cross-sectional view of an attachment unit comprised in the lens drive device which concerns on Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens drive device 2, 3, 4 Lens 5 Lens drive mechanism 10 Moving lens body 11 Lens barrel 20 Fixed body 21 Base 22 Cover 80 Rotor 100 Shutter blade (plate-shaped optical member)
150 Optical member drive mechanism 170 Rotor magnet 500 Stator 1000 Lever part 2000 Attached unit

Claims (9)

In a lens driving device having a moving lens body movable in the optical axis direction, a lens driving mechanism for driving the moving lens body in the optical axis direction, and a fixed body on which the moving lens body and the lens driving mechanism are mounted. ,
The fixed body is equipped with an accessory unit including a plate-like optical member that can be switched between a state that appears on the optical path of the lens and a state that it is retracted from the optical path, and an optical member drive mechanism that drives the optical member. And
The optical member driving mechanism includes a rotor including a rotor magnet in which S poles and N poles are alternately formed in a circumferential direction, and passes through both end faces of the rotor magnet, along an outer circumferential side surface of the rotor magnet, in an axial direction. And a driving coil wound so as to extend to the lens, and the rotation of the rotor is transmitted to the optical member.   2. The lens driving device according to claim 1, wherein the optical member is supported on the fixed body directly or via another member in a state of being rotatable around an axis parallel to the optical axis. In claim 1 or 2,
A lens driving device comprising at least one optical member selected from a shutter plate, a diaphragm plate, a color conversion plate, a neutral density filter plate, an infrared filter plate, and an ultraviolet filter plate as the optical member. In claim 1 or 2,
The optical member includes two optical members selected from a shutter plate, a diaphragm plate, a color conversion plate, a neutral density filter plate, an infrared filter plate, and an ultraviolet filter plate,
The optical member drive mechanism includes a first optical member drive mechanism that drives one of the two optical members, and a second optical component drive mechanism that drives the other optical member. A lens driving device. In any of claims 1 to 4,
The rotor and the optical member are mechanically connected via a rotation transmission mechanism that transmits the rotation of the rotor to the optical member;
The lens driving device, wherein the optical member is rotationally driven via the rotation transmission mechanism. In any of claims 1 to 4,
The lens driving device according to claim 1, wherein the optical member is directly connected to the rotor and rotationally driven. In any one of Claims 1 thru | or 6.
The accessory unit is disposed on the subject side with respect to the moving lens body,
The lens driving device according to claim 1, wherein the accessory unit includes a space into which an object side end of the moving lens body enters when the moving lens body moves to a close distance position side on the object side. In any one of Claims 1 thru | or 7,
The lens driving mechanism includes a first magnetic means disposed so as to surround the moving lens body, and the first magnetic means and the magnetic driving mechanism on the moving lens body side. A second magnetic means for rotating around the optical axis; and a conversion mechanism for converting the rotation of the second magnetic means into a force for the moving lens body to move linearly along the optical axis direction. A lens driving device. In any one of Claims 1 thru | or 7,
The lens drive mechanism includes the drive coil and a drive magnet that generates an interlinkage magnetic field in a direction perpendicular to the optical axis direction of the lens with respect to the drive coil.
One of the drive magnet and the drive coil is fixed to the moving lens body, and the other is fixed to the fixed body.

Images