JP2015179206A - Lens barrel and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve alignment accuracy of each linear actuator in a lens barrel, and attain miniaturization of the lens barrel.SOLUTION: A lens barrel according to the present invention comprises a linear actuator of two systems of: a lens drive unit that serves as a linear actuator driving one of lenses in a direction along an optical axis; and a lens shift-purposed drive unit that is composed of a pair of linear actuators and drives one of the lenses along a plane surface orthogonal to the optical axis. When viewing in the direction along the optical axis, the lens shift-purposed drive unit and the lens drive unit are disposed on an opposite side across the optical axis between the lens shift-purposed drive unit and the lens drive unit.

Description

  The present invention relates to a lens barrel that holds a zoom lens and an electronic apparatus including the lens barrel.

  In a lens barrel used in an electronic device such as a camera or a video camera, a linear actuator generally called a linear motor or a voice coil motor is used as a method for driving a part of the lens in a direction along the optical axis. It is known. The linear actuator includes a coil and a permanent magnet. In the linear actuator, a magnetic detection unit such as a Hall element is used for position detection for positioning. A lens barrel provided with a linear actuator is disclosed in, for example, Japanese Patent Application Laid-Open No. 2010-249858.

  In addition, in a lens barrel used in an electronic device such as a camera or a video camera, by driving a part of the lens along a plane perpendicular to the optical axis, the image of the image caused by movement of the lens barrel by hand or the like can be obtained. A lens barrel having an image shake correction mechanism for correcting shake is known. A lens barrel having an image blur correction mechanism includes a lens shift drive unit that drives a part of a lens along a pair of axes that intersect on a plane orthogonal to the optical axis. The lens shift driving unit is constituted by a pair of linear actuators.

JP 2010-249858 A

  When two linear actuators, for example, a linear actuator that drives a part of a lens in a direction along the optical axis and a lens shift drive unit that includes a pair of linear actuators, are stored in the same lens barrel. Leakage flux increases the error of the position detection result by each magnetic detection unit, and causes the positioning accuracy to deteriorate. In order to suppress the leakage magnetic flux from the linear actuator, it is common to provide a magnetic shield, but the installation of the magnetic shield hinders the miniaturization of the lens barrel.

  The present invention has been made in view of the above-described points. In a lens barrel including two systems of linear actuators, the lens barrel is reduced in size while improving the positioning accuracy of each linear actuator. For the purpose.

  A lens barrel according to an aspect of the present invention is a lens barrel that holds a zoom lens optical system including a plurality of lens groups, and has a base portion and an optical axis with respect to the base portion during zooming operation. A cylindrical first frame member that moves in a direction along the axis, and moves along a plane perpendicular to the optical axis with respect to the first frame member, and holds a part of the lens group of the zoom lens optical system. A movable frame, a pair of first permanent magnets fixed to one of the first frame member and the movable frame, and a pair of first permanent magnets fixed to the other of the first frame member and the movable frame A lens shift driving unit that has a coil and drives the movable frame along a pair of axes intersecting on a plane orthogonal to the optical axis, and the magnification change operation on the image side of the first frame member; A part of the zoom lens optical system that moves in the direction along the optical axis with respect to the base part A second frame member that holds the lens group, a second coil fixed to the base portion, and a second permanent magnet fixed to the second frame member, along the optical axis. A lens driving unit that drives the second frame member, and when the lens shift driving unit, the second frame member, and the lens driving unit are viewed from a direction along an optical axis, The lens shift driving unit and the lens driving unit are disposed on the opposite side with the optical axis in between when viewed from the direction along the optical axis. It is arranged.

  An electronic device of one embodiment of the present invention includes the lens barrel and an imaging element.

  According to the present invention, in a lens barrel having two types of linear actuators, it is possible to reduce the size of the lens barrel while improving the positioning accuracy of each linear actuator.

It is a perspective view of an imaging device provided with a lens barrel. It is a perspective view of a lens barrel. It is a front view of a lens barrel. It is a longitudinal cross-sectional view along the optical axis of the lens barrel in a shortened state. It is a longitudinal cross-sectional view along the optical axis of the lens barrel in the wide end state. It is a longitudinal cross-sectional view along the optical axis of the lens barrel in the tele end state. It is a disassembled perspective view of a lens barrel. It is a perspective view which shows the back surface of a lens-barrel. FIG. 5 is a cross-sectional view taken along a plane perpendicular to the optical axis O of the lens barrel in a shortened state (cross-sectional view taken along line IX-IX in FIG. 4). It is the perspective view which expanded the base part. It is a figure which expand | deploys the outer peripheral surface of a cam frame, and shows a cam profile. It is a figure which expand | deploys the internal peripheral surface of a cam frame, and shows a cam profile. It is a graph which shows the relationship between rotation angle (theta) of a cam frame, and the distance L from the image surface to the surface top of a 1st-3rd lens group. It is a perspective view of a 3rd lens group holding frame. It is a disassembled perspective view of a lens shift mechanism part. It is the figure which looked at the 3rd lens group holding frame and the movable frame from the front. It is XVII-XVII sectional drawing of FIG. It is XVIII-XVIII sectional drawing of FIG. It is XIX-XIX sectional drawing of FIG. It is a figure which shows the 5th lens group holding frame and the front part of a base part. It is XXI-XXI sectional drawing of FIG. It is A arrow directional view in FIG. 21 (imaging state). It is A arrow directional view in FIG. 21 (shortening state).

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings used for the following description, the scale of each component is made different in order to make each component recognizable on the drawing. It is not limited only to the quantity of the component described in (1), the shape of the component, the ratio of the size of the component, and the relative positional relationship of each component.

  The lens barrel 1 of the present invention is used in an electronic apparatus having an imaging function such as a digital camera or a digital video camera, and holds a zoom lens optical system composed of a plurality of lens groups.

  FIG. 1 shows an external appearance of a digital camera 100 which is an example of an electronic apparatus provided with the lens barrel 1 of the present invention. In the following, the axis parallel to the optical axis O of the zoom lens optical system composed of a plurality of lens groups and the like held by the lens barrel 1 is defined as the Z axis, and two axes orthogonal to each other on a plane orthogonal to the Z axis. Are the X and Y axes. When the digital camera 100 is held in a so-called upright state, the Z axis and the X axis are horizontal axes and the Y axis is a vertical axis. The X axis, the Y axis, and the Z axis are appropriately illustrated in each drawing. In the following, in the direction along the Z axis, the object side (subject side) is the front, and the image side (imaging element side) is the rear.

  The digital camera 100 includes a lens body 1, an image sensor 102, a release switch 103, a strobe unit 104, a power switch 105, and a zoom operation switch 106 in a camera body 101.

  The strobe unit 104 is stored in the camera body 101 when not in use, and is disposed so as to protrude upward when the digital camera 100 is held in an upright state when in use. The strobe unit 104 is disposed on the right side of the lens barrel 1 when the digital camera 100 in an upright state is viewed from the front.

  In the present embodiment, the lens barrel 1 and the image sensor 102 are incorporated in the camera body 101 of the digital camera 100, but at least one of the lens barrel 1 and the image sensor 102 is attached to and detached from the camera body 101. Possible forms may be used. For example, the digital camera 100 may be configured so that at least one of the lens barrel 1 and the image sensor 102 can be replaced with one having different specifications.

  As schematically shown in FIG. 2, a lens barrel 1 according to an embodiment of the present invention has a zoom lens optical system in which a plurality of frame members holding a zoom lens optical system are extended forward (subject side). An image-capable state in which an image can be formed on the image plane, and a shortened state in which the plurality of frame members are retracted rearward (on the main body side of the digital camera 100) and the total length in the Z-axis direction is shorter than the image-capturing state; The two states can be changed.

  Further, the focal length of the zoom lens optical system can be changed, and the lens barrel 1 can change the focal length of the zoom lens optical system by moving a plurality of frame members along the optical axis O. It is. FIG. 4 is a cross-sectional view when the lens barrel 1 is in a shortened state. FIG. 5 is a cross-sectional view when the lens barrel 1 is in a photographing state and the zoom lens optical system has the shortest wide end at the wide end. FIG. 6 is a cross-sectional view when the lens barrel 1 is in a photographing state and the telephoto end has the longest focal length of the zoom lens optical system. As will be described in detail later, the switching operation between the shortened state and the photographing state in the lens barrel 1 is mainly performed by the power of the telescopic drive motor 31 a that is an electric motor included in the telescopic drive unit 31.

  FIG. 7 is an exploded perspective view of the lens barrel 1. FIG. 8 is a perspective view showing the back surface of the lens barrel 1. FIG. 9 is a cross-sectional view taken along a plane orthogonal to the optical axis O (cross-sectional view taken along the line IX-IX in FIG. 4). FIG. 10 is an enlarged perspective view of the base unit 2.

  The zoom lens optical system held by the lens barrel 1 includes a first lens group 21 having a positive refractive power, a second lens group 22 having a negative refractive power, a third lens group 23 having a positive refractive power, and a negative refractive power. Of the fourth lens group 24 and the fifth lens group 25 having a positive refractive power. A light amount control unit 16 including a shutter mechanism and a diaphragm mechanism is disposed between the second lens group 22 and the third lens group 23. In addition, the light amount control unit 16 of the present embodiment includes a mechanism that selectively arranges an ND filter on the optical axis O.

  The first lens group 21 has a role of correcting the image plane position by moving in the direction of the optical axis O during zooming operation. The second lens group 22, the third lens group 23, and the fifth lens group 25 have a function of changing magnification by moving in the direction of the optical axis O.

  The lens barrel 1 includes a first lens group holding frame 11 and a second lens that hold a first lens group 21, a second lens group 22, a third lens group 23, a fourth lens group 24, and a fifth lens group 25, respectively. A group holding frame 12, a movable frame 41 of the third lens group holding frame 13, a fourth lens group holding frame 14, and a fifth lens group holding frame 15 are provided. The light quantity control unit 16 is fixed to the third lens group holding frame 13.

  As will be described in detail later, the lens barrel 1 moves the movable frame 41 that holds the third lens group 23, which is a shift lens group, in parallel to a plane orthogonal to the optical axis O, thereby forming an image on the image plane. A lens shift mechanism 40 that realizes a blur correction function by a so-called lens shift method. The lens shift mechanism 40 is disposed on the third lens group holding frame 13. The configuration of the lens shift mechanism 40 that drives the movable frame 41 will be described later.

  In addition, the lens barrel 1 is driven to rotate during a zooming operation or a collapsing operation supported by the fixed frame 3 and a base frame 2 that holds the image sensor 102, a fixed frame 3 that is fixed to the base unit 2. In addition, the cam frame 4 that is driven back and forth in the direction along the optical axis O, the float key 5 that moves forward and backward in the direction along the optical axis O together with the cam frame 4 in the rotation restricted state, and the light together with the cam frame 4 in the rotation restricted state. The guide frame 6 that advances and retreats in the direction along the axis O, the telescopic drive unit 31 that is the first lens drive unit that rotationally drives the cam frame 4, and the fourth lens group holding frame 14 advance and retreat in the direction along the optical axis O. A fourth lens group driving unit 34 for driving, and a fifth lens group driving unit 35 which is a second lens driving unit for driving the fifth lens group holding frame 15 forward and backward in the direction along the optical axis O. Yes. The first lens group holding frame 11, the second lens group holding frame 12, and the third lens group holding frame 13 are in a rotation-restricted state, and advance and retreat in a direction along the optical axis O as the cam frame 4 rotates.

  Details of each configuration of the lens barrel 1 will be described below.

  The base unit 2 is a substantially flat plate-like member, and holds the image sensor 102 on the optical axis O. That is, the position of the base unit 2 is fixed with respect to the image plane of the zoom lens optical system that is ready for photographing. As shown in an enlarged view in FIG. 10, a guide for guiding the fourth lens group holding frame 14 and the fifth lens group holding frame 15 on the front surface of the base portion 2 so as to be movable back and forth in the direction along the optical axis O. Shafts 17 and 18 are erected. The guide shafts 17 and 18 are round bar-shaped members having a circular cross section, and are fixed to the base portion 2 so that the central axis is parallel to the optical axis O. The fourth lens group holding frame 14 and the fifth lens group holding frame 15 are formed with bearing portions that slide along the guide shafts 17 and 18, respectively.

  Further, on the front surface of the base portion 2, a detent shaft 19 that restricts the rotation of the fourth lens group holding frame 14 and the fifth lens group holding frame 15 around the guide shafts 17 and 18 is provided upright. The anti-rotation shaft 19 is a round bar-shaped member having a circular cross section, and is fixed to the base portion 2 so that the central axis is parallel to the optical axis O. The fourth lens group holding frame 14 and the fifth lens group holding frame 15 are formed with bearing portions 15 b that slide along the detent shaft 19.

  A fifth lens group driving unit 35 is disposed on the front surface of the base 2. The fifth lens group drive unit 35 includes a permanent magnet 35a (not shown in FIG. 10) fixed to the fifth lens group holding frame 15 and a coil 35b (not shown in FIG. 10) fixed to the base portion 2. And a magnet-movable linear motor. The fifth lens group driving unit 35 drives the fifth lens group holding frame 15 forward and backward in the direction along the optical axis O. The detailed configuration of the fifth lens group driving unit 35 will be described later.

  As shown in FIG. 9, the guide shaft 18 and the detent shaft 19 for guiding the fifth lens group holding frame 35 and the fifth lens group driving unit 35 for driving the fifth lens group holding frame 35 are arranged on the optical axis O. When viewed from the direction along, the second lens group is disposed at a position on the inner side of the outer diameter of the third lens group holding frame 13 described later.

  The fifth lens group driving unit 35 is disposed in an upper right region with respect to the optical axis O when the digital camera 100 in an upright state is viewed from the front. The expression of the upper right direction with respect to the optical axis O is used for convenience to describe the relative positional relationship with other members disposed around the optical axis O described later. It is what.

  The fixed frame 3 is a member fixed to the camera body 101 and the base unit 2, and is disposed on the outermost periphery among the plurality of substantially cylindrical frame members constituting the lens barrel 1. As shown in FIG. 7, cam grooves 3 a and linear grooves 3 b and 3 c are carved on the inner peripheral surface of the substantially cylindrical fixed frame 3. The cam groove 3a is formed by connecting an inclined groove 3a1 formed in a direction inclined with respect to the optical axis O and a circumferential groove 3a2 formed in the circumferential direction. In the cam groove 3a, a cam follower 4c provided on the outer peripheral surface 4a of the cam frame 4 described later is slidably fitted. The linear grooves 3b and 3c are linear grooves parallel to the optical axis O. A protrusion provided on the outer peripheral surface of the float key 5 described later is slidably inserted into the linear groove 3b. A protrusion 6a provided on the outer peripheral surface of a guide frame 6 to be described later is slidably inserted into the immediately preceding groove 3c.

  A telescopic drive unit 31 and a fourth lens group drive unit 34 are disposed on the outer periphery of the fixed frame 3. As shown in FIG. 3, when the lens barrel 1 is viewed from the front, the expansion / contraction drive unit 31 and the fourth lens group drive unit 34 are disposed at positions facing each other across the optical axis O. In addition, when the digital camera 100 in the upright state is viewed from the front, the expansion / contraction drive unit 31 is disposed at a lower right position with respect to the optical axis O, and the fourth lens group drive unit 34 is The optical axis O is disposed at the upper left position.

  In the digital camera 100, the telescopic drive unit 31 protrudes from the lower part of the lens barrel 1 toward the right side. A strobe unit 104 is disposed in the space above the telescopic drive unit 31.

  The extendable drive unit 31 includes an extendable drive motor 31a, a long gear 31b, and a plurality of gears described below. The long gear 31b is a pinion gear having a rotation axis parallel to the optical axis O, and is exposed on the inner periphery of the fixed frame 3 as shown in FIG. The long gear 31 b meshes with a gear portion 4 g provided on the outer periphery of the cam frame 4. The telescopic drive motor 31a is a servo motor that generates power for rotationally driving the long gear 31b. The power of the telescopic drive motor 31a is transmitted to the long gear 31b through a transmission gear mechanism including a plurality of gears shown in FIG. The telescopic drive motor 31a and the transmission gear mechanism are housed in a gear box 31h provided so as to protrude from the outer peripheral surface of the fixed frame 3. The transmission gear mechanism includes a worm screw 31c, a worm wheel 31d, a first Z gear 31e, a second Z gear 31f, and an idle gear 31g.

  The telescopic drive motor 31a is disposed on the rear side of the gear box 31h so that the rotation axis is substantially parallel to a plane (XY plane) orthogonal to the optical axis O. A worm screw 31c is fixed to the rotation shaft of the telescopic drive motor 31a. The worm wheel 31d that meshes with the worm screw 31c is disposed so that the rotation axis is parallel to the optical axis O. Thus, the rotation shaft of the output of the telescopic drive motor 31a is bent by about 90 degrees by a so-called worm drive mechanism.

  The first Z gear 31e, the second Z gear 31f, and the idle gear 31g are arranged in the gear box 31h on the front side of the telescopic drive motor 31a so that the rotation axis is parallel to the optical axis O. The first Z gear 31e meshes with the worm wheel 31d, and the idle gear 31g meshes with the long gear 31b. The rotation of the worm wheel 31d is transmitted to the long gear 31b via the first Z gear 31e, the second Z gear 31f, and the idle gear 31g.

  In the present embodiment, in the gear box of the telescopic drive unit 31, the telescopic drive motor 31a, the first Z gear 31e, the second Z gear 31f, and the idle gear 31g are arranged so as to overlap in the optical axis O direction. By adopting a floor structure, the height of the gear box 31h in the Y direction is suppressed. That is, in this embodiment, when the digital camera 100 in the upright state is viewed from the front, the height of the gear box 31h in the vertical direction can be reduced. As a result, a space in which the strobe unit 104 (shown in FIG. 3) is disposed above the gear box 31h can be increased in the vertical direction.

  The fourth lens group drive unit 34 includes a stepping motor 34a having a rotating output shaft, a screw (not shown) that is a male screw that rotates with the output shaft of the stepping motor 34a, and a nut (not shown) that has a female screw portion that is screwed into the screw. It is comprised.

  The fourth lens group drive unit 34 is configured to rotationally drive a screw by a stepping motor 34a and to drive a nut back and forth in a direction along the optical axis O. The fourth lens group holding frame 34 moves forward and backward in the direction along the optical axis O together with the nut.

  The cam frame 4 is a substantially cylindrical member, and is fitted in the inner peripheral portion of the fixed frame 3 in a state where the cam frame 4 can rotate and advance and retract. At the rear part of the outer peripheral surface 4a of the cam frame 4, a plurality of cam followers 4c that are slidably fitted into the plurality of cam grooves 3a of the fixed frame 3, respectively, and a gear portion 4g that meshes with the long gear 31b of the telescopic drive unit 31 Is formed.

  As described above, the cam follower 4c of the cam frame 4 is slidably fitted into the cam groove 3a of the fixed frame 3, and the gear portion 4g is engaged with the long gear 31b. Therefore, the cam frame 4 is rotated by the power of the telescopic drive unit 31. When the cam frame 4 rotates, the cam follower 4 c of the cam frame 4 moves along the cam groove 3 a of the fixed frame 3.

  When the lens barrel 1 is in a shortened state, when the cam frame 4 rotates counterclockwise when viewed from the front, the cam frame 4 moves forward while rotating in the range where the cam follower 4c is indented into the inclined groove 3a1. To do. Further, in a range where the cam follower 4c is recessed in the circumferential groove 3a2, the cam frame 4 rotates without moving back and forth in the direction along the optical axis O.

  Here, the cam follower 4c is indented into the inclined groove 3a1 from the shortened state shown in FIG. 4 until the lens barrel 1 is brought into the wide end state shown in FIG. . When the lens barrel 1 is in a photographing enabled state, that is, when the lens barrel 1 is between the wide end state shown in FIG. 5 and the tele end state shown in FIG. 6, the cam follower 4c has a circumferential groove. Invaded to 3a2. That is, when the lens barrel 1 is in a photographing enabled state, the cam frame 4 is driven only in the rotational direction by the telescopic drive unit 31 without moving back and forth in the direction along the optical axis O.

  Further, as shown in FIGS. 11 and 12, a plurality of cam grooves are carved on the outer peripheral surface 4a and the inner peripheral surface 4b of the cam frame 4. FIG. 11 is a development view in which the cylindrical surface portion of the outer peripheral surface 4a of the cam frame 4 is developed in a plane, and FIG. is there.

  On the outer peripheral surface 4a of the cam frame 4, there are six first cam grooves including three first main cam grooves 4d having the same cam profile and three first sub cam grooves 4e having the same cam profile. It is carved. The first main cam grooves 4d and the first sub cam grooves 4e are provided alternately in the circumferential direction.

  The cam frame 4 is recessed inside the first lens group holding frame 11. In the first main cam groove 4d and the first sub cam groove 4e, a main cam follower 11a and a sub cam follower 11b that protrude from the inner peripheral surface of the first lens group holding frame 11 are slidably inserted.

  Further, on the inner peripheral surface 4b of the cam frame 4, three second cam grooves 4f having the same cam profile are carved. A cam follower 12a projecting on the outer peripheral surface of the second lens group holding frame 12 and a cam follower 13a projecting on the outer peripheral surface of the third lens group holding frame 13 are slidably inserted into the second cam groove 4f. To do.

  Details of the plurality of cam grooves formed in the cam frame 4 and the cam followers that are inserted into the cam grooves will be described later.

The float key 5 is formed in a cylindrical shape, and is fitted in the inner peripheral portion of the cam frame 4 so as to be relatively rotatable. FIG. 7 shows a state in which the float key 5 is inserted into the cam frame 4.

  On the outer peripheral portion of the rear side end portion of the float key 5, a protruding portion is provided that is slidably fitted into the linear groove 3 b of the fixed frame 3. When the projection is slidably fitted into the linear groove 3 b of the fixed frame 3, the rotation of the float key 5 around the optical axis O with respect to the fixed frame 3 is restricted.

  In addition, the float key 5 can rotate relative to the cam frame 4 around the optical axis O, and does not move forward and backward relative to the cam frame 4 in the direction along the optical axis O. The cam frame 4 is engaged.

  Three cylindrical slits 5b and three linear slits 5c whose longitudinal direction is parallel to the optical axis O are formed in the cylindrical portion of the float key 5 that is recessed in the cam frame 4. The straight slits 5 b and 5 c penetrate the inner and outer peripheries of the float key 5. The straight slits 5b and 5c are alternately arranged in the circumferential direction.

  The second lens group holding frame 12 and the third lens group holding frame 13 are recessed inside the float key 5. Inside the float key 5, the second lens group holding frame 12 is positioned in front of the third lens group holding frame 13.

  A cam follower 12a projecting from the outer peripheral surface of the second lens group holding frame 12 passes through the linear slit 5b so as to be slidable. Thereby, the rotation of the second lens group holding frame 12 around the optical axis O with respect to the fixed frame 3 is restricted, but can advance and retreat in a direction parallel to the optical axis O. In addition, a cam follower 13a that protrudes from the outer peripheral surface of the third lens group holding frame 13 passes through the linear slit 5c so as to be slidable. Thereby, the rotation of the third lens group holding frame 13 around the optical axis O with respect to the fixed frame 3 is restricted, but can advance and retreat in a direction parallel to the optical axis O.

  As described above, the cam follower 12a and the cam follower 13a included in the second lens group holding frame 12 and the third lens group holding frame 13 are slid into the second cam groove 4f formed on the inner peripheral surface 4b of the cam frame 4. It has been invaded. For this reason, when the cam frame 4 rotates around the optical axis O, the second lens group holding frame 12 and the third lens group holding frame 13 are parallel to the optical axis O along the shape of the second cam groove 4f. Move forward and backward in the direction.

  The guide frame 6 is a substantially cylindrical member, and is disposed outside the first lens group holding frame 11 and inside the fixed frame 3. On the outer peripheral portion of the rear end portion of the guide frame 6, a protrusion 6 a that is slidably fitted into the linear groove 3 c of the fixed frame 3 is provided. When the protrusion 6 a is slidably fitted into the linear groove 3 c of the fixed frame 3, the rotation of the guide frame 6 around the optical axis O with respect to the fixed frame 3 is restricted.

  The guide frame 6 can rotate relative to the cam frame 4 around the optical axis O, and does not move forward and backward relative to the cam frame 4 in the direction along the optical axis O. The cam frame 4 is engaged.

  A linear groove 6 b that is a linear groove parallel to the optical axis O is formed on the inner peripheral surface of the guide frame 6. A protrusion 11c provided on the outer peripheral surface of the first lens group holding frame 11 is slidably inserted into the linear groove 6b. Thereby, the rotation of the first lens group holding frame 11 around the optical axis O with respect to the fixed frame 3 is restricted, but can advance and retreat in a direction parallel to the optical axis O.

  As described above, the main cam follower 11a and the sub cam follower 11b of the first lens group holding frame 11 are in the first main cam groove 4d and the first sub cam groove 4e formed on the outer peripheral surface 4a of the cam frame 4. It is slidable. Therefore, when the cam frame 4 rotates around the optical axis O, the first lens group holding frame 11 is parallel to the optical axis O along the shapes of the first main cam groove 4d and the first sub cam groove 4e. Move forward and backward in the direction.

  Next, details of the plurality of cam grooves formed in the cam frame 4 will be described.

  As shown in FIG. 11, on the outer peripheral surface 4a of the cam frame 4, three first main cam grooves 4d and three first sub cam grooves 4e are alternately formed in the circumferential direction. The first main cam groove 4d and the first sub cam groove 4e have the same cam profile, and the second sub cam groove 4e is disposed in front of the first main cam groove 4d. In the present embodiment, it is possible to form six cam grooves having the same cam profile by offsetting the first main cam groove 4d and the second sub cam groove 4e in the front-rear direction as described above. ing.

  The main cam follower 11a and the sub cam follower 11b of the first lens group holding frame 11 are slidably inserted into the first main cam groove 4d and the first sub cam groove 4e. In FIG. 11, the position of the main cam follower 11a when the lens barrel 1 is in the shortened state is indicated by reference numeral 11a (R), and the position of the main cam follower 11a when the lens barrel 1 is in the wide end state is indicated by reference numerals. 11a (W), and the position of the main cam follower 11a when the lens barrel 1 is in the tele end state is indicated by reference numeral 11a (T). In FIG. 11, the position of the secondary cam follower 11b when the lens barrel 1 is in the shortened state is indicated by reference numeral 11b (R), and the position of the secondary cam follower 11b when the lens barrel 1 is in the wide end state. Is denoted by reference numeral 11b (W), and the position of the sub cam follower 11b when the lens barrel 1 is in the telephoto end state is denoted by reference numeral 11b (T).

  Here, the fitting between the first sub cam groove 4e and the sub cam follower 11b is set to be looser than the fitting between the first main cam groove 4d and the main cam follower 11a. Specifically, the first main cam groove 4d and the main cam follower 11a are always kept in contact with each other, but there is a gap between the first sub cam groove 4e and the sub cam follower 11b.

  That is, the movement of the first lens group holding frame 11 in the direction along the optical axis O accompanying the rotation of the cam frame 4 is performed by the engagement of the three pairs of first main cam grooves 4d and the main cam follower 11a. In the present embodiment, when an external force is applied to the first lens group holding frame 11 by dropping or the like, in addition to the engagement of the three pairs of first main cam grooves 4d and the main cam follower 11a, the three pairs of first auxiliary sub-frames. Even in the engaging portion between the cam groove 4e and the sub cam follower 11b, this external force is received, so that the first lens group holding frame 11 is unlikely to drop off.

  Further, the first sub cam groove 4e is opened forward at the front end portion of the cam frame 4, and when the lens barrel 1 is in the tele end state, as shown in FIG. The cam follower 11 b is disengaged from the first sub cam groove 4 e and is positioned in front of the front end of the cam frame 4.

  On the other hand, as shown in FIG. 12, three second cam grooves 4 f are formed on the inner peripheral surface 4 b of the cam frame 4. The cam follower 12a of the second lens group holding frame 12 and the cam follower 13a of the third lens group holding frame 13 are slidably inserted into the second cam groove 4f.

  In FIG. 12, the position of the cam follower 12a when the lens barrel 1 is in the shortened state is indicated by reference numeral 12a (R), and the position of the cam follower 12a when the lens barrel 1 is in the wide end state is indicated by reference numeral 12a (R). W), and the position of the cam follower 12a when the lens barrel 1 is in the tele end state is indicated by reference numeral 12a (T). In FIG. 12, the position of the cam follower 13a when the lens barrel 1 is in the shortened state is indicated by reference numeral 13a (R), and the position of the cam follower 13a when the lens barrel 1 is in the wide end state is indicated by reference numerals. The position of the cam follower 13a when the lens barrel 1 is in the tele end state is denoted by reference numeral 13a (T).

  When the lens barrel 1 is assembled, the second lens group holding frame 12 is first engaged in the cam frame 4 with the float key 5 fitted inside, and the cam follower 12a is engaged with the inlet 4f1 of the second cam groove 4f. Insert to fit. Then, by rotating the second lens group holding frame 12 relative to the cam frame 4, the cam follower 12a is moved along the second cam groove 4f. Next, the third lens group holding frame 13 is inserted so that the cam follower 13a engages with the inlet 4f1 of the second cam groove 4f.

Here, as shown in FIG. 12, the width of the second cam groove 4f in which the cam follower 12a of the second lens group holding frame 12 is depressed is W2, and the cam follower 13a of the third lens group holding frame 13 is depressed. In the present embodiment, when the width of the entering region is W3, the width W2 of the second cam groove 4f is narrower than the width W3. Further, the fitting tolerance between the cam follower 12a and the second cam groove 4f and the fitting tolerance between the cam follower 13a and the second cam groove 4f are equal.

  For this reason, when the third lens group holding frame 13 is accidentally inserted into the cam frame 4 when the lens barrel 1 is assembled, the cam follower 13a reaches the width W2 portion of the second cam groove 4f. Since it advances, sliding resistance becomes large. In this way, when assembled in the wrong order, the operator can be made aware of work mistakes by increasing the sliding resistance.

  FIG. 13 shows the relationship between the rotation angle θ of the cam frame 4 and the distance L from the image plane to the top of the first to third lens groups in the lens barrel 1 of the present embodiment. In the graph shown in FIG. 13, the horizontal axis represents the rotation angle θ of the cam frame 4 from the wide end state to the tele end state. θWide is the angle of the cam frame 4 when the lens barrel 1 is in the wide end state, and θTele is the angle of the cam frame 4 when the lens barrel 1 is in the tele end state.

  In the graph shown in FIG. 13, the vertical axis represents the distance L from the image plane to the top of each lens group. A curved line G1 indicated by a solid line indicates the distance from the image plane to the top of the first lens group 21, and a curved line G2 indicated by a broken line indicates the distance from the image plane to the top of the second lens group 22. A curve G3 indicated by a one-dot chain line indicates a distance from the image plane to the top of the third lens group 23.

  As shown in FIG. 13, in the lens barrel 1 of the present embodiment, during the zooming operation from the wide end to the tele end, the first lens group 21 moves to the object side after moving to the image side, The lens group 22 moves to the image side, and the third lens group 23 moves to the object side. The aperture stop moves together with the third lens group 23.

  As described above, in the present embodiment, the first main cam groove 4d (first cam groove) into which the cam follower 11a of the first lens group holding frame 11 is recessed is engraved on the outer peripheral surface 4a of one cam frame 4. The second cam groove 4f into which the cam followers 12a and 13a of the second lens group holding frame 12 and the third lens group 23 are recessed is engraved on the inner peripheral surface 4b. That is, in the present embodiment, it is possible to drive the three lens groups in the direction along the optical axis O by rotating one cam frame 4, reducing the number of members overlapping in the radial direction, and reducing the lens barrel 1. Small diameter can be realized.

  In the present embodiment, the first lens group 21 having a role for correcting the image plane position is moved toward the object side after moving toward the image side upon zooming from the wide end to the tele end. Thus, the total length of the lens barrel 1 in the tele end state can be shortened. In addition, optical performance at the wide end can be ensured.

  Also, as shown in FIGS. 12 and 13, during the zooming operation from the wide end to the tele end, the movement distance ΔG3 in the direction along the optical axis O of the third lens group 23 is the optical axis of the second lens group 22. It is shorter than the movement distance ΔG2 in the direction along O. Thus, by shortening the moving distance ΔG3 of the third lens group 23, the outer diameter of the third lens group 23 can be reduced, and the diameter of the lens barrel 1 can be reduced.

  In the present embodiment, the second lens group 22 is moved to the image side upon zooming from the wide end to the tele end, so that the first lens group 21 and the second lens group 22 are in the tele end state. The interval can be widened. As a result, the total length of the lens barrel 1 can be shortened while increasing the variable magnification load of the second lens group 22.

  In the present embodiment, the third lens group 23 is moved to the object side upon zooming from the wide end to the telephoto end, so that the third lens group 23 that is a shift lens group plays a role of zooming. It also has. As a result, the amount of movement of the other lens units during zooming can be suppressed, and the overall length of the lens barrel 1 can be shortened while realizing a high zoom ratio.

  Although not shown, in the lens barrel 1 of the present embodiment, during the zooming operation from the wide end to the tele end, the fourth lens group 24 moves to the object side and then moves to the object side, and the fifth lens group G5 Moves to the image side.

  By moving the fourth lens group 24 at the time of zooming, image plane position correction and field curvature correction can be performed efficiently. In the present embodiment, by providing the fifth lens group 25 with a zooming function, the movement amount of other lens groups during zooming can be suppressed, and the lens can be realized while realizing a high zooming ratio. The overall length of the lens barrel 1 can be shortened.

  Next, detailed configurations of the third lens group holding frame 13 and the movable frame 41, which are first frame members, will be described. As described above, the third lens group holding frame 13 holds the light amount control unit 16 and the lens shift mechanism 40 in addition to the third lens group 23. FIG. 14 is a perspective view of the third lens group holding frame 13. FIG. 15 is an exploded perspective view of the lens shift mechanism 40. FIG. 16 is a view of the third lens group holding frame 13 and the movable frame 41 as viewed from the front. 17 is a cross-sectional view taken along the line XVII-XVII in FIG.

  The lens shift mechanism unit 40 is configured to move the third lens group 23 along a plane orthogonal to the optical axis O. In the zoom lens optical system of the present embodiment, the third lens group 23 moves along a plane orthogonal to the optical axis O, so that the imaging position on the image plane moves. In the present embodiment, as an example, the third lens group includes four lenses as shown in FIG. 17 and has a positive refractive power.

  As shown in FIG. 15, the lens shift mechanism 40 has a movable frame 41 to which the third lens group 23 is fixed, and a lens shift mechanism that generates power for moving the movable frame 41 along a plane orthogonal to the optical axis O. And a drive unit 50.

  The movable frame 41 includes a substantially cylindrical cylindrical portion 41a in which the third lens group 23 is fixed, and a flange portion 41b extending radially outward from the outer peripheral surface of the cylindrical portion 41a. . The movable frame 41 is disposed so as to be relatively movable along a plane orthogonal to the optical axis O with respect to the third group lens holding frame 13.

  Specifically, as shown in FIGS. 15, 16, and 17, the movable frame 41 is a plate that is substantially orthogonal to the rear surface of the flange portion 41 b and the optical axis O that protrudes to the inside of the third group lens holding frame 13. Three balls 44 are sandwiched between the front surface of the support portion 13b. Coil springs 45 that urge the flange portion 41b toward the support portion 13b are installed between the flange portion 41b and the support portion 13b at three locations in the vicinity of the three balls 44. The movable frame 41 is movable relative to the third lens group holding frame 13 along a plane perpendicular to the optical axis O by the rolling of the balls 44. The ball 44 may be made of a magnetic material such as iron, or may be made of a non-magnetic material such as ceramic.

  The coil spring 45 may be covered with a viscoelastic material. By covering the coil spring 45 with a viscoelastic material, a vibration damping effect can be imparted to the coil spring 45. Further, a part or all of the three coil springs 45 may be configured to attract the movable frame 41 to the support portion 13b by magnetic force.

  The support portion 13b provided in the third lens group holding frame 13 is formed with a through hole 13c through which the optical axis O passes. In addition, through holes 13d, 13e, and 13f that penetrate in the direction substantially parallel to the optical axis O are formed in the support portion 13b.

  The through hole 13d is formed at a position overlapping the stepping motor 35a and the screw 35b of the fifth lens group driving unit 35 when viewed from the direction along the optical axis O. When the lens barrel 1 is in a shortened state, the screw 35b protruding forward from the base portion 2 penetrates into the through hole 13d.

  The through holes 13e and 13f are formed at positions overlapping the guide shaft 18 and the detent shaft 19 when viewed from the direction along the optical axis O, respectively. When the lens barrel 1 is in a shortened state, the guide shaft 18 and the rotation prevention shaft 19 protruding forward from the base portion 2 penetrate into the through holes 13e and 13f.

  The lens shift driving unit 50 has a configuration called a so-called linear motor or voice coil motor that generates a driving force by passing a current through a coil in a magnetic field of a permanent magnet.

  As shown in FIG. 15, the lens shift driving unit 50 includes a permanent magnet 51x and a flat coil 52x that constitute a magnet movable linear motor for generating a driving force in the direction along the X axis, and a direction along the Y axis. The permanent magnet 51y and the flat coil 52y which comprise the magnet movable type linear motor for generating this driving force are included.

  The permanent magnets 51x and 51y, which are first permanent magnets, are fixed to the flange portion 41b of the movable frame 41. The flat coil 52x and the flat coil 52y, which are the first coils, are fixed to the rear side of the light quantity control unit 16. As described above, the light quantity control unit 16 is fixed to the front side of the third lens group holding frame 13.

  The permanent magnets 51x and 51y, the flat coil 52x and the flat coil 52y constituting the lens shift driving unit 50 are located on the side of the third lens group 23 in the third lens group holding frame 13, that is, the third lens group 23. It is arrange | positioned in the radial direction outer side. In other words, the permanent magnets 51x and 51y, the flat coil 52x, and the flat coil 52y constituting the lens shift driving unit 50 are arranged at positions overlapping the third lens group 23 in the direction along the optical axis O. .

  As shown in FIGS. 16 and 18, the flat coil 52 x is a coil in which a conducting wire is wound around an axis parallel to the optical axis O, and the Y direction is the longitudinal direction when viewed from the direction along the optical axis O. It has a substantially oval or substantially rectangular outer diameter. The flat coil 52 x is fixed to the rear side surface of the light quantity control unit 16.

  The permanent magnet 51x is fixed to the front surface of the flange portion 41b of the movable frame 41 so as to face the flat coil 52x behind the flat coil 52x. When the surface facing the flat coil 52x is divided into two regions in the X direction, the permanent magnet 51x is magnetized differently so that one region becomes an N pole and the other region becomes an S pole. . In other words, the permanent magnet 51x is magnetized so that different magnetic poles are arranged in the X direction on the surface of the permanent magnet 51x facing the flat coil 52x. The permanent magnet 51x of the present embodiment is a different pole facing type in which two permanent magnets magnetized in the optical axis direction are joined so that different magnetic poles face each other in the X direction. May be.

  A plate-like yoke 55x made of a magnetic material is disposed behind the permanent magnet 51x, that is, on the surface opposite to the surface facing the flat coil 52x of the permanent magnet 51x. As described above, by passing a current through the flat coil 52x disposed in the magnetic field of the permanent magnet 51x and the yoke 55x, the permanent magnet 51x is applied to the flat coil 52x fixed to the third lens group holding frame 13. A force is generated to move the X in the X direction.

  As shown in FIGS. 16 and 19, the flat coil 52 y is a coil in which a conducting wire is wound around an axis parallel to the optical axis O, and the X direction is the longitudinal direction when viewed from the direction along the optical axis O. The outer diameter is substantially oval or substantially rectangular. The flat coil 52 y is fixed to the rear surface of the light quantity control unit 16.

  The permanent magnet 51y is fixed to the front surface of the flange portion 41b of the movable frame 41 so as to face the flat coil 52y behind the flat coil 52y. When the surface facing the flat coil 52y is divided into two regions in the Y direction, the permanent magnet 51y is magnetized differently so that one region becomes an N pole and the other region becomes an S pole. . In other words, the permanent magnet 51y is magnetized so that different magnetic poles are arranged in the Y direction on the surface of the permanent magnet 51y facing the flat coil 52y. In addition, the permanent magnet 51y of this embodiment is a different pole facing type formed by joining two permanent magnets magnetized in the optical axis direction so that different magnetic poles face each other in the Y direction. .

  A plate-like yoke 55y made of a magnetic material is disposed behind the permanent magnet 51y, that is, on the surface of the permanent magnet 51y opposite to the surface facing the flat coil 52y. By passing a current through the flat coil 52y disposed in the magnetic field of the permanent magnet 51y and the yoke 55y as described above, the permanent magnet 51y is applied to the flat coil 52y fixed to the third lens group holding frame 13. A force is generated to move the lens in the Y direction.

  The lens shift driving unit 50 may be a so-called coil movable linear motor in which a permanent magnet is fixed to the third lens group holding frame 13 and a flat coil is fixed to the movable frame 41.

  The lens shift drive unit 50 includes auxiliary permanent magnets 54x and 53y and Hall elements 53x and 53y. The auxiliary permanent magnets 54x and 53y are fixed to the movable frame 41, and the Hall elements 53x and 53y are fixed to the third lens group holding frame 13. The auxiliary permanent magnets 54 x and 53 y and the hall elements 53 x and 53 y are arranged around the third lens group 23 and inside the third lens group holding frame 13.

  As shown in FIG. 18, the auxiliary permanent magnet 54 x is fixed to the rear surface of the flange portion 41 b of the movable frame 41 behind the yoke 55 x. As shown in FIG. 16, the permanent magnet 54 x and the auxiliary permanent magnet 54 x are disposed at overlapping positions when viewed from the direction along the optical axis O. The hall element 53x is fixed to the support portion 13b of the third lens group holding frame 13 so as to face the auxiliary permanent magnet 54x. The hall element 53x is disposed in a through hole 13g formed in the support portion 13b.

  When the rear surface is divided into two regions in the X direction, the auxiliary permanent magnet 54x is magnetized differently so that one region has an N pole and the other region has an S pole. In other words, the auxiliary permanent magnet 54x is magnetized so that different magnetic poles are arranged in the X direction on the surface of the auxiliary permanent magnet 54x facing the Hall element 53x. The auxiliary permanent magnet 54x of the present embodiment is a different pole facing type formed by joining two permanent magnets magnetized in the optical axis direction so that different magnetic poles face each other in the X direction. is there. The Hall element 53x is disposed so as to face the boundary between the N pole surface and the S pole surface of the auxiliary permanent magnet 54x facing opposite poles.

  As shown in FIG. 19, the auxiliary permanent magnet 54 y is fixed to the rear surface of the flange portion 41 b of the movable frame 41 behind the yoke 55 y. As shown in FIG. 16, the permanent magnet 54 y and the auxiliary permanent magnet 54 y are disposed at overlapping positions when viewed from the direction along the optical axis O. The hall element 53y is fixed to the support portion 13b of the third lens group holding frame 13 so as to face the auxiliary permanent magnet 54y. The hall element 53x is disposed in a through hole 13g formed in the support portion 13b.

  When the rear surface is divided into two regions in the Y direction, the auxiliary permanent magnet 54y is magnetized differently so that one region has an N pole and the other region has an S pole. In other words, the auxiliary permanent magnet 54y is magnetized so that different magnetic poles are arranged in the Y direction on the surface of the auxiliary permanent magnet 54y facing the hall element 53y. The auxiliary permanent magnet 54y of the present embodiment is a heteropolar facing type formed by joining two permanent magnets magnetized in the optical axis direction so that different magnetic poles face each other in the Y direction. is there. The Hall element 53y is disposed so as to face the boundary between the N-pole surface and the S-pole surface of the different-pole-facing auxiliary permanent magnet 54y.

  The hall elements 53x and 53y detect a change in the magnetic field caused by the movement of the auxiliary permanent magnets 54x and 54y fixed to the movable frame 41 with respect to the third lens group holding frame 13. From the change in the magnetic field detected by the Hall elements 53x and 53y, the position of the movable frame 41 with respect to the third lens group holding frame 13 can be calculated.

  Here, as shown in FIG. 9, when the lens barrel 1 is viewed from the direction along the optical axis O, the lens shift drive unit 50 is provided with the fifth lens group drive unit 35 provided on the base unit 2. The guide shaft 18 and the non-rotating shaft 19 are disposed at positions that do not overlap.

  More specifically, when the digital camera 100 in the upright state is viewed from the front, the lens shift driving unit 50 is disposed in the left and lower regions of the third lens group 23. When the digital camera 100 in an upright state is viewed from the front, the permanent magnet 51x, the flat coil 52x, and the hall element 53x are disposed on the left side of the third lens group 23, and the permanent magnet 51y, the flat coil The 52y and the hall element 53y are disposed below the third lens group 23.

  Here, as described above, the fifth lens group driving unit 35 is disposed in the upper right region with respect to the optical axis O when the digital camera 100 in the upright state is viewed from the front. It can be said that the shift drive unit 50 is disposed on the opposite side of the fifth lens group drive unit 35 across the optical axis O.

  Although not shown, the lens shift drive unit 50 includes a yoke made of a magnetic material for controlling the path of the lines of magnetic force.

  The light quantity control unit 16 is fixed to the front of the third lens group holding frame 13, but is arranged so that the above-described flat coil 52x and flat coil 52y protrude rearward from the light quantity control unit 16. It is installed.

  The light quantity control unit 16 includes a shutter actuator 16a for driving the shutter, a diaphragm actuator 16b for driving the diaphragm, and an ND filter actuator 16c for driving the ND filter. The shutter actuator 16a, the diaphragm actuator 16b, and the ND filter actuator 16c protrude toward the rear of the light quantity control unit 16, and as shown in the sectional view of FIG. Is located. In other words, the rear ends of the shutter actuator 16a, the diaphragm actuator 16b, and the ND filter actuator 16c are located behind the front end of the third lens group 23, and in the direction along the optical axis O, The third lens group 23 is disposed at a position overlapping with the third lens group 23.

  Here, as shown in FIG. 9, when the lens barrel 1 is viewed from the direction along the optical axis O, the shutter actuator 16a, the diaphragm actuator 16b, and the ND filter actuator 16c include the lens shift drive unit 50. The fifth lens group drive unit 35, the guide shaft 18 and the detent shaft 19 are disposed at positions that do not overlap.

  In the lens barrel 1 of the present embodiment, when the third lens group holding frame 13 is closest to the base unit 2 in the shortened state, the fifth lens group driving unit 35 protruding forward from the base unit 23, the guide The front end portions of the shaft 18 and the detent shaft 19 are positioned on the side of the third lens group 23.

  As described above, the lens shift driving unit 50, the shutter actuator 16a, the diaphragm actuator 16b, and the ND filter, which are members disposed on the side of the third lens group 23 in the third lens group holding frame 13. The actuator 16c is disposed at a position that does not overlap with the fifth lens group drive unit 35, the guide shaft 18, and the rotation-preventing shaft 19 when viewed from the direction along the optical axis O, so that they interfere with each other. There is no.

  The power supply to the lens shift drive unit 50, the shutter actuator 16a, the diaphragm actuator 16b, and the ND filter actuator 16c and input / output of control signals are performed via the second flexible printed circuit board 61 shown in FIG. Done. As shown in FIG. 8, the second flexible printed circuit board 61 is drawn to the outer peripheral surface of the fixed frame 3. The portion of the second flexible printed circuit board 61 drawn to the outer peripheral surface of the fixed frame 3 is disposed along the outer peripheral surface of the fixed frame 3, and the imaging element 102 is interposed via the planar connector 62. Is electrically connected to the first flexible printed circuit board 60 on which is mounted. The first flexible printed circuit board 60 is connected to a control board (not shown) of the digital camera 100 at the connection portion 60a.

  Next, a detailed configuration of the fifth lens group driving unit 35 that is a lens driving unit that drives the fifth lens group holding frame 15 that is the second frame member along the optical axis O will be described. FIG. 20 is a view of the base unit 2 and the fifth lens group holding frame 15 as viewed from the front along the optical axis O. FIG. FIG. 21 is a cross-sectional view taken along the line XXI-XXI in FIG. FIG. 22 is a view of the base 2, the fourth lens group holding frame 14, and the fifth lens group holding frame 15 in a shooting state as viewed from a direction orthogonal to the optical axis O (A in FIG. 21). Arrow view). FIG. 23 is a view of the base 2, the fourth lens group holding frame 14, and the fifth lens group holding frame 15 in a shortened state as viewed from a direction orthogonal to the optical axis O (see arrow A in FIG. 21). ).

  The fifth lens group drive unit 35 includes a permanent magnet 35a that is a second permanent magnet, a coil 35b that is a second coil, an inner yoke 35d, and an outer yoke 35e. The fifth lens group driving unit 35 is a magnet-movable linear motor in which a permanent magnet 35 a is fixed to the fifth lens group holding frame 15 and a coil 35 b is fixed to the base unit 2.

  The coil 35 b has a shape in which a conductive wire is wound around an axis substantially parallel to the optical axis O so as to be a substantially rectangular shape when viewed from a direction along the optical axis O. In other words, the coil 35b has a substantially rectangular outer shape in a cross section by a plane orthogonal to the optical axis O.

  The permanent magnet 35a is disposed so as to face one surface 35ba of the two surfaces having long sides in the cross section of the coil 35b. The permanent magnet 35a and the coil 35b are not in contact with each other. As shown in FIG. 21, the permanent magnet 35a is magnetized so as to be polarized in a direction orthogonal to the surface 35ba of the coil 35b.

  More specifically, in the present embodiment, the coil 35b whose cross section by a plane orthogonal to the optical axis O has a substantially rectangular shape has one surface 35ba, which is a long side in the cross section, facing the optical axis O. It is arranged like this. The permanent magnet 35a is magnetized so as to be polarized in a direction perpendicular to the optical axis O. In the present embodiment, as shown in the figure, the permanent magnet 35a is magnetized so that the side facing the coil 35b is the N pole and the side facing the optical axis O is the S pole. The magnetic poles of the permanent magnet 35a may be reversed.

  The inner yoke 35d is made of a magnetic material such as iron and is inserted inside the coil 35b. The outer yoke 35e is made of a magnetic material such as iron, and is disposed so as to cover four surfaces of the outer surface of the coil 35b excluding the surface 35ba facing the permanent magnet 35a and the object-side end surface. In other words, the outer yoke 35e has a channel shape extending substantially parallel to the optical axis O and having a substantially U-shaped cross section by a plane orthogonal to the optical axis O. The image side end of the outer yoke 35e having a channel shape is closed and opened toward the object side. The outer yoke 35e opens toward the object side. The inner yoke 35d is coupled to a portion covering the image side end surface of the coil 35b of the outer yoke 35e.

  Further, a pair of surfaces of the outer yoke 35e covering a pair of short sides in the cross section of the coil 35b protrudes toward the permanent magnet 35a side from the surface 35ba of the coil 35b, and covers the side surface of the permanent magnet 35a. The permanent magnet 35a and the outer yoke 35e are not in contact with each other.

  The outer yoke 35e and the coil 35b are fixed by an adhesive. The outer yoke 35e is fixed to the base portion 2 with screws. Thereby, the coil 35b is fixed with respect to the base part 2. FIG. Note that a magnetic attractive force is generated between the permanent magnet 35 a fixed to the fifth lens group holding frame 15 and the outer yoke 35 e fixed to the base portion 2 in the shortened state. In a shortened state in which power is not supplied to the fifth lens group driving unit 35, the permanent magnet 35a and the outer yoke 35e are attracted to each other, so that the position of the fifth lens group holding frame 15 as the second frame member is reached. Hold.

  Moreover, the coil 35b is electrically connected to the 3rd flexible printed circuit board 63 arrange | positioned at the back side of the base part 2, as shown in FIG. The third flexible printed circuit board 63 is also electrically connected to the telescopic drive motor 31a and the electric motor of the fourth lens group drive unit. The third flexible printed circuit board 63 is electrically connected to a control board (not shown) of the digital camera 100.

  In the fifth lens group driving unit 35 having the above-described configuration, a magnetic circuit is formed between the permanent magnet 35a, the outer yoke 35e, and the inner yoke 35f, and a current is passed through the coil 35b placed in the magnetic circuit. The force that drives the permanent magnet 35a in the direction along the optical axis O relative to the coil 35b is generated. By this force, the fifth lens group holding frame 15 is driven in a direction along the optical axis O.

  As shown in FIG. 10, the fifth lens group drive unit 35 includes a position detection unit 36 and an origin detection unit 37. The position detection unit 36 is configured to detect the position of the fifth lens group holding frame 15. The position detection unit 36 includes a magnetic scale 36 a fixed to the fifth lens group holding frame 15 and a magnetic detection unit 36 b fixed to the base unit 2.

  The magnetic scale 36a is formed such that different magnetic poles are alternately present in a predetermined cycle in the direction along the optical axis O. The magnetic detection unit 36 b is an MR element, a Hall element, or the like, and detects a change in the magnetic field caused by the movement of the magnetic scale 36 a together with the fifth lens group holding frame 15. The position detector 36 detects the moving direction and moving distance of the magnetic scale 36a from the change in the magnetic field detected by the magnetic detector 36b. The position detection unit 36 and the magnetic scale 36 a may be fixed to the base unit 2, and the magnetic detection unit 36 b may be fixed to the fifth lens group holding frame 15.

  The position detection unit 36 is disposed in an upper right region with respect to the optical axis O when the digital camera 100 in an upright state is viewed from the front. That is, the position detection unit 36 is disposed on the opposite side of the lens shift driving unit 50 with the optical axis O in between.

  In the origin detection unit 37, the position detection unit 36 includes a light shielding piece 37 a provided in the fifth lens group holding frame 15 and a photo interrupter 37 b fixed to the base unit 2. The origin detection unit 37 detects the origin of the fifth lens group driving unit 35 by detecting the light shielding piece 37a that moves together with the fifth lens group holding frame 15 by the photo interrupter 37b. The magnetic detection unit 36 b and the photo interrupter 37 b are mounted on a third flexible printed circuit board 63 disposed on the back side of the base unit 2.

  As described above, in the lens barrel 1 of the present embodiment, the fifth lens group driving unit 35 that drives the fifth lens group 25 in the direction along the optical axis O and the third lens group 23 are orthogonal to the optical axis O. Two systems of linear actuators including a lens shift driving unit 50 that drives along a plane are provided. Here, when the lens barrel 1 is viewed from the front in parallel with the optical axis O, the fifth lens group driving unit 35 and the lens shift driving unit 50 are disposed so as to sandwich the optical axis O therebetween. ing. With this arrangement, the Hall elements 53x and 53y included in the lens shift drive unit 50 are moved away from the fifth lens group drive unit 35, and the magnetic detection unit 36b included in the fifth lens group drive unit 35 is replaced with the lens shift drive unit. Can be moved away from 50.

  For this reason, the influence of the leakage magnetic flux from the lens shift driving unit 50 on the position detection using the magnetic detection unit 36b, and the leakage magnetic flux from the fifth lens group driving unit 35 are detected using the Hall elements 53x and 53y. Can be reduced. Accordingly, in a lens barrel including a linear actuator that drives the lens along the optical axis O and a linear actuator that drives the lens along a plane orthogonal to the optical axis O, the positioning accuracy of both linear actuators is improved. However, the outer diameter of the lens barrel can be reduced.

  In addition to the lens shift drive unit 50, the lens barrel 1 of the present embodiment has a shutter actuator 16 a and an aperture stop around the third lens group 23 that is a movable lens in a lens shift type blur correction mechanism. An actuator 16b and an ND filter actuator 16c are arranged.

  Further, in the lens barrel 1 of the present embodiment, when viewed from the direction along the optical axis O, the guide shaft 18, the detent shaft 19 and the fifth lens group driving unit for driving the fifth lens group 25 forward and backward. 35 is disposed on the inner side of the outer diameter of the third lens group holding frame 13 and on the outer side of the outer diameter of the third lens group 23.

  The guide shaft 18, the detent shaft 19, and the fifth lens group drive unit 35 for driving the fifth lens group 25 forward and backward are projected forward from the base portion 2. When the lens barrel 1 is in a shortened state, as shown in FIG. 9, a lens shift driving unit 50, a shutter actuator 16a, an aperture actuator 16b, and an ND filter disposed around the third lens group 23 are provided. It arrange | positions in the position which does not interfere with the actuator 16c for use.

  The lens barrel 1 of the present embodiment having such a configuration includes a guide shaft 18, a detent shaft 19 and a fifth lens group drive unit 35 for driving the fifth group lens holding frame 15 forward and backward, and a third lens group. The third lens group holding frame 13 having the lens shift drive unit 50 can be further shortened while the entire outer diameter can be reduced by disposing it inside the outer diameter of the holding frame 13. Sometimes, the total length in the shortened state can be shortened by bringing it close to the base portion 2.

  Further, in the present embodiment, the configuration is such that the light quantity control unit 16 and the lens shift drive unit 50 are held by the third lens group holding frame 13, so that electromagnetic components are gathered and arranged on the third lens group holding frame 13. Therefore, man-hours during assembly can be reduced.

  Further, in the present embodiment, in the lens shift drive unit 50, the Hall elements 53x and 54y are viewed from behind the permanent magnets 51x and 52y, which are the first permanent magnets, from the direction along the optical axis O. It arrange | positions in the position which overlaps with the permanent magnets 51x and 52y. The hall elements 53x and 53y are disposed in the through holes 13g and 13h formed in the support portion 13b of the third group holding frame 13. With such a configuration, the Hall elements 53x and 53y can be disposed in a space-saving manner, and the overall length in the shortened state can be shortened.

  The lens barrel 1 is provided between the fifth lens group holding frame 15 and the base, and a compression coil spring is disposed around the guide shaft 18, and the fifth lens group holding frame 15 is moved by the compression coil spring. You may have the structure urged | biased ahead. In this case, when the power is not supplied to the fifth lens group driving unit 35, the fifth lens group holding frame 15 comes into contact with the fourth lens holding frame 14 by the biasing force of the compression coil spring, and the fifth lens is driven. The position of the group holding frame 15 is fixed.

  In addition, as a configuration in which the position of the fifth lens group holding frame 15 is fixed in a shortened state in which power is not supplied to the fifth lens group driving unit 35, one of the base unit 2 and the fifth lens group holding frame 15 is fixed. A configuration is conceivable in which the fifth lens group holding frame 15 is attracted to the base 2 by fixing a permanent magnet and fixing a member made of a magnetic material to the other.

  Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification, and a lens mirror accompanying such a change. The cylinder is also included in the technical scope of the present invention.

  For example, the present invention relates to a lens barrel that holds a zoom lens optical system including N lens groups in which a first lens group to an Nth lens group are arranged in order from the object side. 2) The lens shift driving unit 50 is disposed in the lens group, and the Nth lens group can be applied to a lens unit for zooming that is driven in a direction along the optical axis O by a magnet-movable linear motor. For example, when the lens barrel holds a zoom lens optical system including six lens groups, the fourth lens group is driven on a plane orthogonal to the optical axis O by the lens shift driving unit 50, and The present invention can also be applied to the case where the six lens groups are driven in the direction along the optical axis O by a magnet movable linear motor.

  The lens barrel according to the present invention is not limited to a form provided in a so-called digital camera (lens-integrated or interchangeable lens camera or video camera), and has an imaging function of a portable communication terminal, a game machine, a digital media player, or the like. Needless to say, the electronic device may be provided in a form.

  As an example of an electronic apparatus including a lens barrel according to the present invention, an imaging device, a wireless communication unit including a wireless communication function such as a wireless LAN, and a control unit are configured, and a so-called smartphone An imaging device configured to be able to communicate with a mobile communication terminal such as a tablet-type terminal via a wireless communication unit is conceivable. The imaging device performs a scaling operation and an imaging operation in response to an instruction input to the mobile communication terminal by a user, an image processing operation of an image as an imaging result, an image transmission / reception operation with the mobile communication terminal, and the like. Run. That is, the imaging device can be remotely operated using a mobile communication terminal.

  In addition, the imaging apparatus may be configured to use an image display apparatus of a mobile communication terminal that is not provided with an image display apparatus and is connected via a wireless communication unit as a separated viewfinder. In this case, the imaging apparatus may include an adapter that can be mechanically fixed to the main body of the mobile communication terminal.

1 lens barrel,
2 base part,
3 fixed frame,
3a Cam groove,
3a1 inclined groove,
3a2 circumferential groove,
3b straight groove,
3c straight groove,
4 Cam frame,
4a outer peripheral surface,
4b inner peripheral surface,
4c cam follower,
4d first main cam groove,
4e 1st sub cam groove,
4f Second cam groove,
4f1 entrance,
4g gear part,
5 Float key,
5b Straight slit,
5c straight slit,
6 guide frame,
6a protrusion,
6b straight groove,
11 First lens group holding frame;
11a Main cam follower,
11b Deputy cam follower,
11c protrusion,
12 Second lens group holding frame;
12a Cam follower,
12d front part,
13 Third lens group holding frame (first frame member),
13a Cam follower,
13b support part,
13c through hole,
13d through hole,
13e through hole,
13f through hole,
13g through hole,
13h through hole,
14 Fourth lens group holding frame;
14a bearing part,
14b bearing part,
15 Fifth lens group holding frame (second frame member),
16 Light quantity control unit,
16a shutter actuator,
16b Aperture actuator,
16c ND filter actuator,
17 Guide shaft,
18 guide shaft,
19 Non-rotating shaft,
21 1st lens group,
22 Second lens group,
23 Third lens group,
24 4th lens group,
25 fifth lens group,
31 telescopic drive unit,
31a telescopic drive motor,
31b long gear,
31c Worm screw,
31d worm wheel,
31e 1st Z gear,
31f 2nd Z gear,
31g idle gear,
31h Gearbox,
34 Fourth lens group drive unit,
35 fifth lens group driving unit (lens driving unit),
35a permanent magnet (second permanent magnet),
35b coil (second coil),
35c York,
35d inner yoke,
35e outer yoke,
36 position detector,
36a magnetic scale,
36b magnetic detection unit,
37 Origin detector,
37a shading piece,
37b Photo interrupter,
40 Lens shift mechanism,
41 Movable frame,
41a cylindrical part,
41b flange part,
44 balls,
45 Coil spring,
50 lens shift drive,
51x, 51y permanent magnet (first permanent magnet),
52x, 52y flat coil (first coil),
53x, 53y Hall element,
54x, 54y auxiliary permanent magnet,
55x, 55y York,
60 first flexible printed circuit board,
60a connection part,
61 2nd flexible printed circuit board,
62 connectors,
63 third flexible printed circuit board,
100 Digital camera (electronic equipment),
101 body,
102 imaging device,
103 Release switch,
104 Strobe unit,
105 Power switch,
106 Zoom operation switch.

Claims (4)

A lens barrel that holds a zoom lens optical system composed of a plurality of lens groups,
A base,
A cylindrical first frame member that moves in a direction along the optical axis with respect to the base portion during zooming operation;
A movable frame that moves along a plane perpendicular to the optical axis with respect to the first frame member and holds a part of the lens group of the zoom lens optical system;
A pair of first permanent magnets fixed to one of the first frame member and the movable frame; and a pair of first coils fixed to the other of the first frame member and the movable frame. A lens shift drive unit for driving the movable frame along a pair of axes intersecting on a plane orthogonal to the optical axis;
The second frame member that moves in the direction along the optical axis with respect to the base portion during the zooming operation on the image side of the first frame member, and holds a part of the lens group of the zoom lens optical system. When,
A lens driving unit having a second coil fixed to the base and a second permanent magnet fixed to the second frame member, and driving the second frame member along the optical axis When,
Comprising
The lens shift driving unit, the second frame member, and the lens driving unit are arranged so as to fit inside the first frame member when viewed from the direction along the optical axis.
The lens barrel, wherein the lens shift driving unit and the lens driving unit are disposed on opposite sides of the optical axis therebetween when viewed from a direction along the optical axis. The zoom lens optical system includes N lens groups,
The movable frame holds the (N-2) th lens group from the object side,
The lens barrel according to claim 1, wherein the second frame member holds the Nth lens group from the object side. A light amount control unit fixed to the object side of the first frame member,
A part of the light amount control unit has a part protruding toward the image side so as to overlap the (N-2) -th lens group in the optical axis direction around the movable frame, and the part has an optical axis. 3. The lens barrel according to claim 2, wherein the lens barrel is arranged so as not to overlap the lens driving unit when viewed from a direction along the line.   An electronic apparatus comprising the lens barrel according to any one of claims 1 to 3 and an imaging element.

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