JP2018189936A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel capable of reducing the diameter of a lens barrel while maintaining the driving force of a VCM, or increasing the diameter of a lens without changing the diameter of the lens barrel. SOLUTION: The lens barrel has a first extending portion extending in the optical axis direction of the lens and a second extending portion extending in the optical axis direction of the lens on the cylindrical member side of the first extending portion. A yoke having an extension portion, a connecting portion connecting the first extension portion and the second extension portion at one end in the optical axis direction, and a first extension portion side of the second extension portion. The first magnet arranged on the surface of the lens and the first extending portion arranged on the lens holding frame so that the surface on which the long side portion and the short side portion are arranged are perpendicular to the optical axis of the lens. A coil that is wound around the lens and can move in the optical axis direction along the first extension portion by the magnetic flux from the magnet, and a second lens that is arranged at a position where the magnetic flux can be supplied to one short side portion of the coil. It is equipped with a magnet. [Selection diagram] Fig. 4

Description

  The present invention relates to a lens barrel that moves a lens holding frame in an optical axis direction by, for example, a voice coil motor (VCM).

  The lens barrel includes a lens holding frame that holds a lens, a cylindrical member that houses and arranges the lens holding frame, and a voice coil motor (VCM) that moves the lens holding frame in the optical axis direction of the lens inside the cylindrical member. The VCM includes a coil, a magnet, and a yoke. The coil is fixed to the lens holding frame in such a direction that its air core is parallel to the optical axis. The magnet is fixed to the cylindrical member so as to face the coil.

  Then, when the coil is energized with the magnetic flux across the coil, the coil is biased in the optical axis direction by electromagnetic force, and the lens holding frame moves in the optical axis direction within the cylindrical member. When the direction of the current flowing through the coil is changed, the moving direction of the lens holding frame is changed.

International Publication No. 2013/121788 JP 2006-99513 A

  In order to reduce the diameter of the lens barrel or increase the diameter of the lens without changing the diameter of the lens barrel, a method of reducing the VCM magnet can be considered. However, if the magnet is simply made smaller, the driving force of the VCM is reduced and the lens holding frame cannot be driven.

  The present invention has been made in view of the above points, and can reduce the diameter of the lens barrel while maintaining the driving force of the VCM, or increase the diameter of the lens without changing the diameter of the lens barrel. An object of the present invention is to provide a lens barrel that can be used.

  One aspect of the lens barrel of the present invention is a lens barrel that moves a lens holding frame in the optical axis direction of a lens held by the lens holding frame with respect to a cylindrical member, and the lens barrel moves in the optical axis direction of the lens. A first extending portion that extends, a second extending portion that extends in the optical axis direction of the lens closer to the cylindrical member than the first extending portion, a first extending portion, and a second extending portion A connecting portion that connects the extending portion at one end in the optical axis direction, the yoke fixed to the cylindrical member, and the first extending portion side surface of the second extending portion. The first magnet is fixed to the lens holding frame, and is wound around the first extension portion so that the surface on which the long side portion and the short side portion are arranged is perpendicular to the optical axis of the lens. A coil that can move in the direction of the optical axis along the first extension by the magnetic flux from the second magnet, a second magnet that is arranged at a position where magnetic flux can be supplied to one short side of the coil, It is provided.

  One aspect of the lens barrel of the present invention is a lens barrel that moves a lens holding frame in the optical axis direction of a lens with respect to a cylindrical member, and a yoke in which a first magnet and a second magnet are arranged. And a first coil wound around a first portion extending in the optical axis direction at a position corresponding to the first magnet of the yoke, and fixed to the lens holding frame. A second coil wound around a second portion extending in the optical axis direction at a position corresponding to the second magnet of the yoke, and disposed in the yoke when viewed from the optical axis direction of the lens, A third magnet disposed between the first magnet and the second magnet, and the third magnet supplies magnetic flux to the first and second coils.

  According to the lens barrel of the present invention, the diameter of the lens barrel can be reduced while maintaining the driving force of the VCM, or the diameter of the lens can be increased without changing the diameter of the lens barrel.

FIG. 1 is a cross-sectional view of the interchangeable lens according to the first embodiment cut along the optical axis. FIG. 2 is a perspective view of the assembly incorporated in the interchangeable lens of FIG. 1 as viewed obliquely from the front. 3 is a perspective view of the assembly of FIG. 2 as viewed obliquely from the rear. FIG. 4 is a perspective view in which a part of the assembly of FIG. 2 is partially broken along F4-F4. FIG. 5 is a cross-sectional view of the assembly of FIG. 2 cut along F5-F5. FIG. 6 is a cross-sectional view of the structure of FIG. 1 in which the assembly of FIG. 2 is incorporated in a fixed frame, taken along a plane perpendicular to the optical axis, as viewed from the F6 direction. FIG. 7 is a perspective view showing the positional relationship between the shake correction mechanism of FIG. 1 and the rear lens holding frame. FIG. 8 is a diagram for explaining the effect of the first embodiment. FIG. 9 is a perspective view illustrating a main part of the interchangeable lens according to the second embodiment. FIG. 10 is a diagram for explaining the effect of the second embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view of an interchangeable lens 100, which is a first embodiment of a lens barrel of the present invention, cut along a plane including an optical axis O thereof. For example, the interchangeable lens 100 is detachably attached to a digital camera (not shown). In the following description, a subject side (not shown) along the optical axis O (the left side in FIG. 1) is the front, and a camera body side (not shown) (the right side in FIG. 1) is the rear.

  The interchangeable lens 100 has a substantially cylindrical outer frame 1 whose outer diameter slightly increases toward the front along the optical axis O. A substantially cylindrical fixed frame 2 (cylindrical member) is attached to the inside of the outer frame 1. A plurality of lenses 3 are coaxially provided in front of the fixed frame 2. Inside the fixed frame 2, movable lenses 4 and 6 are provided so as to be movable in the front-rear direction along the optical axis O. Behind the fixed frame 2 is provided a blur correction mechanism 8 that moves the lens 7 along a plane orthogonal to the optical axis O. A lens 3 is provided between the movable lens 6 and the lens 7. An imaging lens 9 is provided behind the blur correction mechanism 8. Each lens 3, 4, 6, 7, 9 is coaxially mounted such that the optical axis O passes through its center.

  The blur correction mechanism 8 is provided on the fixed frame 2 so as to face the hall element 62 so as to form a lens holding frame 61 holding the lens 7, a hall element 62 attached to the lens holding frame 61, and a magnetic flux passing through the hall element 62. The magnet 63 is provided. The hall element 62 detects the position of the lens holding frame 61 by detecting a change in the magnetic field accompanying the movement along the plane orthogonal to the optical axis O of the lens holding frame 61.

  FIG. 2 shows a combination of a support mechanism 10 that supports the movable lenses 4 and 6 movably in the optical axis O direction, an actuator 20 that drives the front movable lens 4, and an actuator 30 that drives the rear movable lens 6. It is the perspective view which looked at the solid 40 from diagonally forward. FIG. 3 is a perspective view of the assembly 40 as viewed obliquely from the rear, and FIG. 4 is a perspective view showing a part of the structure of the assembly 40 of FIG. FIG. 5 is a cross-sectional view of the assembly 40 of FIG. 2 cut along a plane including the optical axis O. FIG. 6 is a cross-sectional view of the structure 50 in which the assembly 40 is incorporated in the fixed frame 2 taken along a plane orthogonal to the optical axis O. The assembly 40 is assembled in the fixed frame 2 and attached in the outer frame 1.

  The support mechanism 10 supports the lens holding frame 11 holding the front movable lens 4 so as to be movable in the optical axis O direction, and can move the lens holding frame 12 holding the rear movable lens 6 in the optical axis O direction. To support. The actuator 20 drives the front lens holding frame 11 supported by the support mechanism 10 in the front-rear direction along the optical axis O. The actuator 30 drives the rear lens holding frame 12 supported by the support mechanism 10 in the front-rear direction along the optical axis O.

  The lens holding frames 11 and 12 are arranged side by side in the optical axis O direction in a posture along a plane orthogonal to the optical axis O. The movable range along the optical axis O of each of the lens holding frames 11 and 12 is limited to a range where they do not come into contact with each other by a stopper or the like (not shown).

  The support mechanism 10 includes four guide shafts 13, 14, 15, and 16 that support the two lens holding frames 11 and 12 so as to be movable in the optical axis O direction. These four guide shafts 13, 14, 15, 16 are extended in parallel to the optical axis O in the vicinity of the inner surface of the fixed frame 2, and one end of each is directly fixed to the fixed frame 2 and the other end is fixed. It is fixed to a fixed lid 5 (FIG. 1) fixed integrally to the frame 2. Each guide shaft 13, 14, 15, 16 is fixed at both ends by providing a fixing lid 5 integrally fixed to the fixed frame 2, even if both ends are directly fixed to the fixed frame 2. It may be fixed via a member that is provided.

  The two guide shafts 13, 15 are assigned to the front lens holding frame 11, and are provided on the opposite side with the movable lens 4 interposed therebetween while being spaced apart in the radial direction of the movable lens 4. The two guide shafts 14, 16 are assigned to the rear lens holding frame 12, and are provided on the opposite side with the movable lens 6 interposed therebetween while being spaced apart in the radial direction of the movable lens 6. That is, the guide shafts 13 and 15 support the front lens holding frame 11 so as to be movable in the optical axis direction. In addition to the front lens holding frame 11, the guide shafts 14 and 16 support the rear lens holding frame 12 so as to be movable in the optical axis direction.

  The front lens holding frame 11 has a U-shaped fitting groove 11 a that fits into the guide shaft 13 and a through hole 11 b that passes through the guide shaft 15. The rear lens holding frame 12 has a U-shaped fitting groove 12 a that fits into the guide shaft 14, and a through hole 12 b that passes through the guide shaft 16. The through hole 11b of the lens holding frame 11 is provided on the opposite side of the fitting groove 11a that is spaced in the radial direction of the movable lens 4, and the through hole 12b of the lens holding frame 12 is movable with respect to the fitting groove 12a. It is provided on the opposite side of the lens 6 that is separated in the radial direction. The rear lens holding frame 12 is formed in a shape that does not interfere with the guide shafts 13 and 15, and the front lens holding frame 11 is formed in a shape that does not interfere with the guide shafts 14 and 16.

  The actuator 20 for driving the front movable lens 4 has two sets of drive units 20a and 20b that are spaced apart from each other in the radial direction of the movable lens 4, and the actuator 30 for driving the rear movable lens 6 is: The movable lens 6 includes two sets of drive units 30a and 30b that are spaced apart from each other in the radial direction. One drive unit 20a of the actuator 20 and one drive unit 30a of the actuator 30 are provided at positions overlapping in the optical axis direction. The other drive unit 20b of the actuator 20 and the other drive unit 30b of the actuator 30 are also provided at positions overlapping in the optical axis direction.

  One drive unit 20a, 30a of each actuator 20, 30 has substantially the same structure as the other drive unit 20b, 30b. The drive units 20a and 20b of the actuator 20 and the drive units 30a and 30b of the actuator 30 have substantially the same structure. That is, the four drive units 20a, 20b, 30a, and 30b have substantially the same structure. Therefore, here, one drive unit 20a will be described as a representative, and description of the other drive units 20b, 30a, and 30b will be omitted.

  For example, one driving portion 20a of the actuator 20 for driving the front lens holding frame 11 is separated from the lens holding frame 11 along the outer peripheral portion of the movable lens 4 as shown in a cross section in FIG. There are two fixed coils 21 and 22. The coil 21 (22) has two long side portions 21a (22a) that are spaced apart from each other in parallel and two short side portions 21b (22b) that are spaced away from each other in parallel. The coil 21 (22) has a posture in which the surface on which the long side portion 21a (22a) and the short side portion 21b (22b) are arranged is perpendicular to the optical axis O (that is, the air core portion of the coil 21 (22) is the optical axis). (An attitude parallel to O) and fixed to the lens holding frame 11. The coil 21 (22) is fixed to the lens holding frame 11 at an angle at which the radial direction of the movable lens 4 and the pair of long side portions 21a (22a) are orthogonal to each other.

The drive unit 20 a includes, in addition to the coils 21 and 22 described above, a yoke 24 fixed to the fixed frame 2 and three magnets 26, 27, and 28 fixed to the yoke 24.
The yoke 24 is separated from each other in the circumferential direction of the movable lens 4 and is adjacent to each other and extends in the direction of the optical axis O, respectively, and a first extending yoke 24a (first portion, first extending portion) and a second. It has the extension yoke 24b (2nd part, 1st extension part). The first and second extending yokes 24 a and 24 b have a length corresponding to the movable range of the movable lens 4 along the optical axis O. The first and second extending yokes 24a and 24b are provided corresponding to the coils 21 and 22, respectively.

  The coils 21 and 22 fixed to the lens holding frame 11 are wound around the first and second extending yokes 24a and 24b in a non-contact state. In other words, the first and second extending yokes 24 a and 24 b are formed in a rectangular plate shape with a flat cross section, and are inserted through the air core portions of the corresponding coils 21 and 22 in a non-contact state. That is, the air core portions of the coils 21 and 22 and the first and second extending yokes 24a and 24b are arranged with a certain gap therebetween. In the first and second extending yokes 24 a and 24 b, the surface facing the optical axis O and the opposite surface separated from the optical axis O are orthogonal to the radial direction of the movable lens 4.

  The yoke 24 has a fixed portion 23 (second extended portion) extending in the optical axis O direction on the fixed frame 2 side (outside in the radial direction) from the first and second extended yokes 24a and 24b. The fixing portion 23 has a shape in which a rectangular plate is bent inward at two locations along the optical axis O. The fixing portion 23 functions as a magnet holding portion that holds three magnets 26, 27, and 28 described later.

  The fixed portion 23 includes a first parallel portion 23a parallel to the optical axis O facing the first extending yoke 24a, a third parallel portion 23c parallel to the optical axis O facing the second extending yoke 24b, and It has the 2nd parallel part 23b parallel to the optical axis O which connected the 1st parallel part 23a and the 3rd parallel part 23c. The first to third parallel portions 23 a to 23 c each have an inner surface and an outer surface that are orthogonal to the radial direction of the movable lens 4. That is, the fixed part 23 is bent between the first parallel part 23a and the second parallel part 23b, and is bent between the second parallel part 23b and the third parallel part 23c. The fixed part 23 is arranged concentrically with the movable lens 4.

  Further, the yoke 24 is a connecting portion that gently connects the front end portion along the optical axis O of the first extending yoke 24a and the front end portion of the first parallel portion 23a of the fixing portion 23 in a U-shape. 24c, and a connecting portion 24d that gently connects the front end portion of the second extending yoke 24b along the optical axis O and the front end portion of the third parallel portion 23c of the fixing portion 23 in a U-shape. .

  Further, the yoke 24 projects between the two connecting portions 24c and 24d from the front end portion of the second parallel portion 23b of the fixed portion 23 toward the optical axis O and protrudes in parallel with the connecting portions 24c and 24d. Have

  In addition to this, the yoke 24 has a substantially fan-shaped end plate portion 25 connecting the rear end portion along the optical axis O of the fixed portion 23 and the rear ends of the first and second extending yokes 24a and 24b. Have. The end plate portion 25 is not an essential configuration and is not necessarily provided.

  The fixing part 23 has two protrusions 23d for positioning that protrude from the outer surface of the second parallel part 23b. As shown in FIG. 6, in a state where the assembly 40 is assembled in the fixed frame 2, the two protrusions 23 d of the fixing portion 23 of the yoke 24 are fitted into the two holes 2 a of the fixed frame 2, respectively. Positioned on the inner surface of the fixed frame 2. The yoke 24 is fixed to the fixed frame 2 with screws. The yoke 24 may be fixed to the fixed frame 2 by adhering the outer surface of the fixed portion 23 to the inner surface of the fixed frame 2.

  In addition, the fixing portion 23 has a plurality of through holes 23e for injecting an adhesive from the outer surface side. In the present embodiment, two through holes 23 e are provided in each of the first to third parallel parts 23 a to 23 c of the fixing part 23. The magnets 26, 27, and 28 are bonded and fixed to the inner surface of the fixing portion 23 of the yoke 24 by the adhesive injected through the plurality of through holes 23 e.

  Magnets 26, 27, and 28 are bonded and fixed to the inner surfaces of the first to third parallel portions 23a, 23b, and 23c of the fixing portion 23, respectively. That is, the three magnets 26, 27 and 28 are arranged concentrically with the movable lens 4. The magnets 26, 27, and 28 have substantially the same length as the first to third parallel portions 23a, 23b, and 23c along the optical axis O. The magnets 26, 27, and 28 are extended in parallel with the optical axis O.

  The magnet 26 is disposed in contact with the inner surface of the first parallel portion 23a (the surface on the first extension yoke 24a side) inside the coupling portion 24c, and is fixed by an adhesive injected through the through hole 23e. 23. The magnet 27 is disposed in contact with the inner surface of the second parallel portion 23b so as to face the inside of the protruding portion 24e, and is fixed to the fixing portion 23 by an adhesive injected through the through hole 23e. The magnet 28 is disposed in contact with the inner surface of the third parallel portion 23c (the surface on the second extending yoke 24b side) inside the connecting portion 24d, and is fixed by an adhesive injected through the through hole 23e. 23.

  With the lens holding frame 11 attached to the two guide shafts 13 and 15, the first and second extending yokes 24 a and 24 b of the yoke 24 are inserted through the air core portions of the coils 21 and 22, and the fixed portion When 23 is fixed to the fixed frame 2, the coils 21, 22 and the first and second extending yokes 24a, 24b are brought into a non-contact state, and the coils 21, 22 and the magnets 26, 28 are brought into a non-contact state. For this reason, the two coils 21 and 22 can move in the direction of the optical axis O without contacting the members around them.

  When a current is passed from the drive circuit (not shown) to the coils 21 and 22, an electric field having a direction corresponding to the direction of the current is generated around the coil 21, and an electric field having a direction corresponding to the direction of the current is generated around the coil 22. . On the other hand, since the magnetic flux from the magnets 26, 27, 28 passes through the coils 21, 22, an electromagnetic force acts on the coils 21, 22 by electromagnetic induction, and the lens holding frame 11 moves to one end side in the optical axis O direction. Is done. When the direction of the current applied to the coils 21 and 22 is changed, the lens holding frame 11 is moved to the other end side in the optical axis direction.

  At this time, the direction of the current flowing through the coils 21 and 22 and the direction of the magnetic poles of the magnets 26, 27 and 28 are set so that the directions of the electromagnetic forces acting on the two coils 21 and 22 are aligned in the same direction. There is a need. If an electromagnetic force opposite to the direction of the electromagnetic force acting on the coil 21 acts on the coil 22, the lens holding frame 11 cannot be moved along the optical axis O. For this reason, in this embodiment, the direction of the current flowing through each coil 21 and 22 and the direction of the magnetic pole of each magnet 26, 27 and 28 are set so that the direction of the electromagnetic force acting on each coil 21 and 22 is the same. Set.

  Further, in the present embodiment, the Hall element 62 provided on the lens holding frame 61 that holds the lens 7 of the blur correction mechanism 8 can be brought close to the Hall element 62 so as not to be affected by the magnetic flux generated in the coils 21 and 22. The direction of the current flowing through each of the coils 21 and 22 and the direction of the magnetic poles of the magnets 26, 27 and 28 are set. Specifically, the direction of the current flowing through the coils 21 and 22 and the magnets 26 so that the directions of magnetic fluxes generated by the two coils 21 and 22 facing each other with the hall element 62 interposed therebetween are opposite to each other. , 27 and 28 are set in the direction of the magnetic poles.

  FIG. 7 is a perspective view showing the positional relationship between the lens holding frame 12 holding the movable lens 6 and the blur correction mechanism 8. In FIG. 7, the magnets 26, 27, 28 on the fixed frame 2 side and the yoke 24 are not shown for easy understanding of the drawing. There is a possibility that the two drive units 30a and 30b provided on the rear lens holding frame 12 along the optical axis O may approach the shake correction mechanism 8, and in this embodiment, one of the two drive units 30a and 30b. The two coils 21 and 22 of the drive unit 30 a are opposed to the Hall element 62. For this reason, when the drive unit 30 a comes closest to the Hall element 62, the magnetic flux generated by the two coils 21 and 22 may pass through the Hall element 62 and become a noise component of the detection signal by the Hall element 62. .

  In this case, if the directions of the magnetic fluxes generated by the two coils 21 and 22 of the driving unit 30a are the same direction, the magnetic fluxes strengthen each other and are detected as noise by the Hall element 62. For this reason, in this embodiment, the direction of the current flowing through the coils 21 and 22 and the respective directions so that the directions of the magnetic fluxes generated by the two coils 21 and 22 of the drive unit 30a are opposite to each other as shown by the arrow B in FIG. The direction of the magnetic poles of the magnets 26, 27, and 28 was set. In this way, by reversing the directions of the magnetic fluxes generated by the two coils 21 and 22, the magnetic fluxes cancel each other and weaken each other, so that the noise detected by the Hall element 62 can be almost eliminated, and the detection accuracy can be improved. Can be increased.

Hereinafter, the effect of the first embodiment will be described with reference to FIG.
FIG. 8A is a schematic diagram illustrating a configuration example of a conventional general drive unit 120. The drive unit 120 is a coil in which a fixed part 123 of a yoke 124 fixed to a fixed frame is formed into a flat plate shape, one magnet 126 is attached to the inner surface of the fixed part 123, and fixed to a lens holding frame. The extended yoke 124 a of the yoke 124 is inserted through the air core portion 121. FIG. 8B is a schematic diagram showing the configuration of the drive unit 20a of the first embodiment described above side by side.

  The drive unit 20a of the first embodiment shown in FIG. 8B is provided with two coils 21 and 22 on the lens holding frame 11, and a yoke 24 provided on the fixed frame 2 is opposed to the coils 21 and 22 3. Two magnets 26, 27, 28 were provided. Compared with the conventional driving unit 120 of FIG. 8A, the driving unit 20a of the first embodiment divides the coil into two and the magnet into three, so that the diameter of the fixed frame 2 is reduced. Is able to. That is, by dividing the configuration arranged around the movable lens 4 into a plurality of parts and arranging them concentrically with the movable lens 4, the dimension of the movable lens 4 in the radial direction is reduced.

  Specifically, the inner diameter of the fixed frame when the conventional drive unit 120 is adopted is R1, whereas the inner diameter of the fixed frame 2 when the drive unit 20a of the first embodiment is used is R2. , R1> R2 holds. This relationship holds when the driving force generated by the driving unit 120 in FIG. 8A and the driving force generated by the driving unit 20a in FIG. 8B are designed to be the same.

  As described above, when the coil is divided into two and laid out in the same angle range as the conventional one, the diameters of the coils 21 and 22 are reduced. Further, if the magnet is divided into three as in the first embodiment, the magnetic flux from each of the magnets 26, 27, and 28 is reduced. Since the driving force in the driving unit is generated when the magnetic flux crosses the coil, if the components of the driving unit are simply divided to make the coils and magnets smaller, the driving force generated by the driving unit becomes weak.

  The magnetic flux from the magnet 26 provided in the first parallel portion 23a of the yoke 24 crosses the long side portion 21a of the coil 21 wound around the first extending yoke 24a substantially perpendicularly. Further, the magnetic flux from the magnet 28 provided on the third parallel portion 23c of the yoke 24 crosses the long side portion 22a of the coil 22 wound around the second extending yoke 24b substantially perpendicularly. Considering only these two sets of magnetic circuits, the magnetic force generated is smaller than that of the conventional driving unit 120 illustrated in FIG. For this reason, in the first embodiment, the third magnet 27 is added between the two magnets 26 and 28 described above.

  The magnetic flux from the third magnet 27 obliquely crosses the short side portion 21 b of the coil 21 and increases the magnetic flux passing through the coil 21. Further, the magnetic flux from the magnet 27 obliquely crosses the short side portion 22 b of the coil 22 and increases the magnetic flux passing through the coil 22. As a result, the magnetic flux passing through the coils 21 and 22 increases, and the driving force increases.

  In other words, in the first embodiment, the magnet 27 is provided between the magnet 26 and the magnet 28 in order to add the magnetic flux passing through the short sides 21b and 22b of the coils 21 and 22. That is, in the first embodiment, the magnet 27 is laid out at a position where the magnetic flux of the magnet 27 passes through the short side portion 21 b of the coil 21 and the magnetic flux of the magnet 27 passes through the short side portion 22 b of the coil 22. Since the arrangement position of the magnet 27 is set to a position where the magnets 26 to 28 are arranged concentrically with the movable lens 4, the size of the drive unit 20 a is not increased by adding the magnet 27.

  As described above, according to the first embodiment, the size of the drive unit 20a along the radial direction of the movable lens 4 can be reduced, and the drive force of the drive unit 20a can be maintained. For this reason, according to the first embodiment, the diameter of the interchangeable lens 100 can be reduced and / or the diameter of the movable lens 4 can be increased without changing the diameter of the interchangeable lens 100.

(Second Embodiment)
FIG. 9 is a perspective view showing the structure of the main part of the interchangeable lens according to the second embodiment. In the interchangeable lens of the second embodiment, the cross-sectional shape along the plane orthogonal to the optical axis O of the coils 21 ′ and 22 ′ in each of the drive units 20 a, 20 b, 30 a, and 30 b and the first extension of the yoke 24 The yoke 24a ′ and the second extending yoke 24b ′ have the same structure as that of the first embodiment described above except that the cross-sectional shapes are different. Therefore, here, the same reference numerals are given to components that function in the same manner as in the first embodiment, and detailed description thereof will be omitted. Also here, the drive unit 20a will be described as a representative, and description of the drive units 20b, 30a, and 30b having the same structure will be omitted.

  The coils 21 ′ and 22 ′ have a substantially pentagonal cross section along a plane orthogonal to the optical axis O. In other words, the coils 21 ′ and 22 ′ include the coil 21 in addition to the pair of long sides 21 a and 22 a orthogonal to the radial direction of the movable lens 4 and the pair of short sides 21 b and 22 b extending substantially in the radial direction. It has opposing side parts 21c and 22c which oppose the magnet 27 arrange | positioned between 'and 22'. The opposing side portions 21 c and 22 c are substantially orthogonal to the radial direction of the movable lens 4 and extend substantially parallel to the magnet 27.

  Further, the cross-sectional shape along the plane orthogonal to the optical axis O of the first extension yoke 24a ′ and the second extension yoke 24b ′ inserted through the air cores of the coils 21 ′ and 22 ′ is also the coil 21 ′, It is a pentagon substantially similar to 22 '. In other words, the first and second extending yokes 24a ′ and 24b ′ are surfaces parallel to the magnet 27 facing the magnet 27 with the opposing sides 21c and 22c of the corresponding coils 21 ′ and 22 ′ interposed therebetween. Have

Hereinafter, the effect of the second embodiment will be described with reference to FIG.
Also in the second embodiment, since the coil is divided into two and the magnet is divided into three as in the first embodiment described above, the driving force of the driving unit 20a is maintained and the fixing frame 2 is maintained. The diameter can be reduced and / or the diameter of the movable lens 4 can be increased without changing the diameter of the interchangeable lens.

  In addition, according to the second embodiment, since the coils 21 ′ and 22 ′ have opposing sides 21 c and 22 c that face the magnet 27 in parallel, the magnetic flux of the magnet 27 has an effect on the coils 21 ′ and 22 ′. As a result, the driving efficiency of the driving unit 20a can be further increased.

  In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not deviate from the summary. Further, the embodiments may be implemented in combination as appropriate, and in that case, the combined effect can be obtained. Furthermore, the present invention includes various inventions, and various inventions can be extracted by combinations selected from a plurality of disclosed constituent elements. For example, even if several constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the problem can be solved and an effect can be obtained, the configuration from which the constituent requirements are deleted can be extracted as an invention.

  For example, in the above-described embodiment, the case where the three magnets 26 to 28 are arranged concentrically around the movable lens 4 is described. However, the present invention is not limited to this, and the magnet 27 is provided between the two coils 21 and 22. The magnetic flux passing through the short sides 21b and 22b may be increased. Or you may provide the one coil 21 and add another magnet which opposes the short side part 21b. Thus, the arrangement position of the magnet to be added can be arbitrarily changed, and is selected according to the application. In any case, the magnetic flux passes through the short side portion 21b (22b) of the coil 21 (22). What is necessary is just to arrange | position to a position.

  In the second embodiment described above, the case where the cross-sectional shapes of the coils 21 ′ and 22 ′ are pentagons has been described. However, the present invention is not limited to this, and the long side portions 21 a facing the magnets 26 and 28 in parallel. What is necessary is just to have the opposing side parts 21c and 22c which oppose in parallel with the magnet 27 in addition to 22a.

  DESCRIPTION OF SYMBOLS 2 ... Fixed frame, 4, 6 ... Movable lens, 10 ... Support mechanism, 11, 12 ... Lens holding frame, 13, 14, 15, 16 ... Guide shaft, 20, 30 ... Actuator, 20a, 20b, 30a, 30b ... Drive part 21, 22, 21 ', 22' ... coil, 21a, 22a ... long side part, 21b, 22b ... short side part, 21c, 22c ... opposite side part, 40 ... assembly, 23 ... fixing part, 23a ... 1st parallel part, 23b ... 2nd parallel part, 23c ... 3rd parallel part, 24 ... Yoke, 24a, 24a '... 1st extension yoke, 24b, 24b' ... 2nd extension yoke, 24c, 24d: connecting portion, 24e: projecting portion, 26, 27, 28 ... magnet, 62 ... Hall element, 100 ... interchangeable lens, O ... optical axis.

Claims (13)

A lens barrel that moves the lens holding frame in the optical axis direction of the lens held by the lens holding frame with respect to the cylindrical member,
A first extension portion extending in the optical axis direction of the lens; a second extension portion extending in the optical axis direction of the lens on the cylindrical member side than the first extension portion; A yoke fixed to the cylindrical member, the connecting portion connecting the first extending portion and the second extending portion at one end in the optical axis direction;
A first magnet fixed to a surface of the second extension part on the first extension part side;
It is fixed to the lens holding frame, and is wound around the first extension portion so that the surface on which the long side portion and the short side portion are arranged is perpendicular to the optical axis of the lens, and from the magnet A coil movable in the optical axis direction along the first extending portion by magnetic flux;
A second magnet disposed at a position where magnetic flux can be supplied to one short side of the coil;
A lens barrel characterized by comprising:   2. The lens barrel according to claim 1, wherein one end of the second magnet is disposed at a position adjacent to the connecting portion of the yoke.   The second extending portion is provided with a protruding portion that protrudes in parallel with the connecting portion toward the optical axis, and the second magnet is disposed to face the protruding portion. The lens barrel according to claim 1. A lens barrel that moves the lens holding frame in the optical axis direction of the lens with respect to the cylindrical member,
A yoke in which a first magnet and a second magnet are disposed;
A first coil fixed to the lens holding frame and wound around a first portion extending in the optical axis direction at a position corresponding to the first magnet of the yoke;
A second coil fixed to the lens holding frame and wound around a second portion extending in the optical axis direction at a position corresponding to the second magnet of the yoke;
A third magnet disposed on the yoke and disposed between the first magnet and the second magnet when viewed from the optical axis direction of the lens. And
The lens barrel, wherein the third magnet supplies magnetic flux to the first and second coils. In the first coil and the second coil, the first part and the second part are arranged such that the surfaces on which the long side part and the short side part are arranged are perpendicular to the optical axis of the lens. Wound around each
The long side portion of each coil is disposed at a position facing the corresponding first magnet or the second magnet,
The lens barrel according to claim 4, wherein a short side portion of each of the coils is disposed at a position where magnetic flux is supplied from the third magnet. The yoke is
A first parallel portion that is parallel to the optical axis, the first magnet being disposed and facing the first portion;
A second parallel part parallel to the optical axis, on which the third magnet is disposed,
A third parallel part, which is parallel to the optical axis, and is disposed opposite to the second part, the second magnet being disposed;
The lens barrel according to claim 4, wherein the lens barrel functions as having a magnet holding portion integrally connected to each other.   The portion of the first parallel portion to the third parallel portion to which the first magnet to the third magnet are attached has a surface parallel to the optical axis direction. Lens barrel.   7. The second parallel portion is provided with a protruding portion that protrudes toward the optical axis, and the third magnet is disposed to face the protruding portion. Lens barrel.   The lens barrel according to claim 4, wherein the first to third magnets are arranged concentrically with the lens.   A drive unit including the yoke on which the first to third magnets are arranged, and the first and second coils fixed to the lens holding frame is arranged on the opposite side across the lens. The lens barrel according to claim 4, wherein the lens barrel is provided in a set.   5. The lens barrel according to claim 4, wherein each of the first and second coils has opposing side portions facing in parallel with the third magnet.   The lens barrel according to claim 4, wherein the first coil and the second coil have a polygonal shape.   5. The lens barrel according to claim 4, wherein the first coil and the second coil have a pentagonal shape.