JP2013050521A - Lens barrel structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel structure in which portions of a lens barrel overlapped in the radial direction are reduced, achieving a reduction in the diameter of the lens barrel used in a lens exchangeable camera.SOLUTION: The lens barrel 10 includes: a lens barrel body 50 for holding lenses; an external ring 20 externally mounted to the lens barrel body 50; an operation ring 30 externally fitted to the outer periphery of the lens barrel body 50 and held in a manner to be rotatable in the circumferential direction with respect to the lens barrel body 50; and a fixed ring 40 for holding the external ring 20 and the operation ring 30 on the lens barrel body 50. The outer shape of the lens barrel 10 is formed by the external ring 20, the operation ring 30 and the fixed ring 40. In the external ring 20, the operation ring 30 and the fixed ring 40, there is no part where the three rings are overlapped at the same time. A portion where the outer shape of the lens barrel 10 is formed only by the operation ring 30 is provided in a plane perpendicular to the optical axis L. Control components for the lens barrel 10 are housed in an interior space formed by the operation ring 30.

Description

  The present invention relates to a lens barrel structure used in an interchangeable lens camera.

  Miniaturization of interchangeable lens cameras is progressing, and along with this, miniaturization of lens barrels is also progressing. Usually, the lens support frame that holds the lens group that contributes to the focus adjustment among the lens groups that constitute the photographing optical system provided in the lens barrel is on the inner peripheral side of the lens barrel body and the optical axis. It is provided so as to be movable in the direction, and the focal position of the light beam incident through the photographing optical system is changed by moving the lens support frame. In order to move the lens support frame to a position where the subject image by the photographing optical system forms an image on the imaging surface of the camera, a rotating frame such as a cam ring is provided rotatably on the inner peripheral side or the outer peripheral side of the lens barrel body, The lens support frame is moved in the optical axis direction by rotating the rotation frame with respect to the lens barrel body.

  In such a lens barrel, in order to detect the amount and direction of rotation of the rotating frame rotated by manual operation, a rotation detection sensor is provided in the barrel body, and the rotation accommodated on the inner peripheral side of the barrel body It is known to detect the amount and direction of rotation of a frame (see Patent Document 1).

International Publication No. 2009/028140 Pamphlet

  However, in such a lens barrel, in order to constitute the lens barrel, a plurality of cylindrical members having different diameters are used on the concentric axis, and a plurality of barrel shapes are formed in the radial direction of the lens barrel. There are many overlapping parts. Actually, from the aesthetic point of view, it can be foreseen that a cylindrical exterior member having a larger diameter will be attached, and it has been difficult to reduce the diameter of the lens barrel.

  An object of the present invention is to reduce the diameter of a lens barrel.

  The lens barrel structure according to the present invention is arranged on the outer periphery of the barrel main body that holds the lens, the exterior ring that is externally mounted on the barrel main body, and is rotatable in the circumferential direction with respect to the barrel main body. An operation ring held by the lens barrel body and a fixed ring that is fixed to the lens barrel body and sandwiches the operation ring between the lens barrel body, and the exterior ring, the operation ring, and the fixed ring are adjacent to each other in the rotation axis direction. And the outer ring, the operation ring, and the fixed ring do not overlap in the radial direction, and there is a surface on which the outer shape is formed only by the operation ring in the plane orthogonal to the optical axis direction. It is characterized by that.

  According to the present invention, there is no portion where the outer ring, the operation ring, and the fixed ring overlap at the same time, and there is a surface in which the outer shape is formed only by the operation ring on the surface orthogonal to the optical axis direction. The diameter of the tube can be reduced.

  In order to reduce the diameter of the lens barrel, the outer shape of the lens barrel is formed by the outer ring, the operation ring, and the fixed ring, and a control component for the lens barrel is provided in the inner space formed by the operation ring. It is preferable to be accommodated.

  In addition, the operation ring has a first step portion formed with different radial dimensions on the lens barrel main body side in the rotation axis direction and a second step portion formed with different radial dimensions on the stationary ring side. It is preferable that the barrel main body is in contact with the first step portion and the stationary ring is in contact with the second step portion, and the operation ring is rotatably held.

  Further, the first step portion and the second step portion are formed on the inner peripheral side of the operation ring, while the outer periphery side of the operation ring has a third step portion formed with a reduced radial dimension, The outer ring is preferably arranged on the outer periphery of the third step portion.

  According to the present invention, it is possible to reduce the overlapping of the lens barrels in the radial direction and reduce the diameter of the lens barrel.

It is the external appearance perspective view seen from the stationary-ring side of the lens-barrel which concerns on embodiment of this invention. It is the external appearance perspective view seen from the bayonet side of the lens barrel which concerns on embodiment of this invention. It is a front view of a fixed ring of a lens barrel according to an embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line IV-IV in a state in which a front decoration plate, a stationary ring, and a lens of a lens barrel according to an embodiment of the present invention are removed. In FIG. 4, it is the VV sectional view taken on the line which attached the front decoration board, the stationary ring, the board | substrate, and the lens. It is a perspective view of the 1st sensor support member and rotation detection sensor before attaching the 2nd sensor support member. It is a perspective view of the 1st sensor support member and the rotation detection sensor after attaching the 2nd sensor support member. It is a fragmentary sectional view showing the state where a rotation detection sensor is attached to the 1st sensor support member. It is a fragmentary sectional view after attaching the 2nd sensor support member.

  Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, an example of a single focus lens will be described as a lens barrel used in an interchangeable lens camera. The lens barrel according to the embodiment of the present invention is used by being mounted on a lens mount of a digital single-lens camera body (not shown).

  The outline of the lens barrel according to the embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an external perspective view of a lens barrel according to an embodiment of the present invention viewed from the stationary ring side, and FIG. 2 is an external perspective view of the lens barrel viewed from the bayonet side. FIG. 3 is a front view of the fixed ring of the lens barrel. FIG. 4 is a cross-sectional view taken along the line IV-IV in a state in which the front decoration plate, the stationary ring, the substrate, and the rods of the lens barrel are removed. FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 4 in a state where the front decoration plate, the stationary ring, the substrate, and the lens are attached. In FIG. 5, the optical axis L is indicated by a one-dot chain line. Hereinafter, the direction parallel to the optical axis L is the optical axis direction, the subject side when photographing the subject is the front side, and the opposite side is the rear side. In this embodiment, the operation ring is a focus ring, and the lens for focusing of the lens barrel is moved to the in-focus position by being guided in a straight line in the optical axis direction according to the rotation of the operation ring.

  As shown in FIGS. 1 to 5, the lens barrel 10 includes a barrel main body 50 that holds the lens groups L <b> 1 to L <b> 4, an exterior ring 20 that is externally mounted on the barrel main body 50, and an outer periphery of the barrel main body 50. An operation ring 30 that is loosely fitted and is rotatably held in the circumferential direction with respect to the lens barrel main body 50, a stationary ring 40 that is fixed to the lens barrel main body 50, a fixed ring 40 that is fixed to the lens barrel main body 50, And a joint ring 120 for holding the mount part 110.

  As shown in FIG. 5, in the operation ring 30, the inner peripheral side dimension on the rear lens barrel body 50 side is enlarged to form the first step portion 30 a, and the inner peripheral side dimension on the front fixed ring 40 side is enlarged. Thus, the second step portion 30b is formed, and the third step portion 30f is formed by reducing the outer dimension on the rear barrel body 50 side. The first step portion 30 a is in contact with the receiving portion 50 a of the lens barrel body 50, and the second step portion 30 b is in contact with the rear end portion 40 a of the stationary ring 40. That is, the operation ring 30 is surrounded by a portion from the first step portion 30a to the second step portion 30b between the receiving portion 50a of the barrel main body 50 and the rear end portion 40a of the fixed ring 40. The lens barrel body 50, the operation ring 30, and the fixed ring 40 are overlapped in the radial direction only in the optical axis L direction only in the adjacent ring. That is, in the operation ring 30, the portion from the first step portion 30 a to the rear end portion 30 c of the operation ring 30 overlaps the lens barrel body 50, while the portion from the second step portion 30 b to the front end portion 30 d of the operation ring 30 is fixed. It overlaps with the ring 40. An elastic O-ring 200 is provided between the flange portion 50b of the barrel main body 50 and the operation ring 30, and the operational feeling is improved by the stable holding of the operation ring 30 and appropriate frictional friction. It is illustrated. The outer ring 20 fixed to the lens barrel body 50 via the joint ring 120 extends to the third step portion 30f of the operation ring 30 in a direction parallel to the optical axis L, and extends from the rear end 30c of the operation ring 30. The O-ring 200 and the part up to the outer peripheral surface of the lens barrel body 50 are covered to play a role of protection and appearance improvement.

  In the present embodiment, there is no portion where the outer ring 20, the operation ring 30 and the fixed ring 40 overlap at the same time, and the outer shape of the lens barrel 10 is the IV-IV line orthogonal to the optical axis L in FIG. Only the operation ring 30 is formed. The operation ring 30 is in contact with the stationary ring 40 and the lens barrel main body 50 and is slidable with respect to the outer peripheral surfaces of the stationary ring 40 and the lens barrel main body 50. As will be described later, by rotating the operation ring 30 around the optical axis L, the fourth lens group L4 for focusing is moved forward and backward along the optical axis L to perform a focusing operation.

  An annular recess 41 is formed in the front end of the fixed ring 40 on the subject side, and an annular front decoration plate 43 centered on the optical axis L is fixed to the annular recess 41. The front decoration plate 43 is formed of the same material as that of the stationary ring 40, and a plurality of annular grooves 44 centering on the optical axis L are formed on the front end face thereof. Three screw holes 42 for fixing the stationary ring 40 to the lens barrel body 50 are formed in the annular recess 41 of the stationary ring 40. The screw holes 42 are evenly spaced in the circumferential direction. In the present embodiment, the screw holes 42 are arranged at intervals of 120 ° in the circumferential direction.

  In the present embodiment, a cylindrical outer shape of the lens barrel 10 is formed by the exterior ring 20, the operation ring 30, and the stationary ring 40 in order from the rear, and the lens barrel body 50 and the lens barrel body 50 are attached to the inside thereof. Various control components for controlling the four lens groups L1 to L4 and the lens barrel 10 are accommodated. In a cylindrical inner space formed on the inner peripheral side of the operation ring 30, for example, a motor 100 for driving a later-described fourth lens unit L <b> 4 or rotation of the operation ring 30 is detected as a control component. A rotation detection sensor 60 is housed, and a first flexible substrate 71 connected to the rotation detection sensor 60 and a second flexible substrate 72 connected to other electronic components (not shown) are connected to the operation ring 30. Other electronic components are arranged in the circumferential direction and accommodated in the operation ring 30. As described above, in the present embodiment, the thickness direction (parallel to the optical axis L) of the operation ring 30 and the space on the inner peripheral side are effectively used, and the lens ring is configured by the exterior ring 20, the operation ring 30, and the fixed ring 40. By forming the outer shape of the tube 10, the diameter of the lens barrel 10 is reduced.

  The lens barrel 10 has a barrel main body 50, a bayonet mount 110, a joint ring 120, four lens groups L1 to L4, and an optical axis L as a central axis inside a cylindrical outer shape. Cylindrical support frames 131 to 133, a rotation detection sensor 60, sensor support members 80 and 90, and a motor 100 are provided. The mount unit 110 is detachably provided on a lens mount of a camera body (not shown). As shown in FIG. 4, the sensor support members 80 and 90 are arc-shaped members provided only in the arc region where the rotation detection sensor 60 is arranged in the circumferential direction of the outer peripheral surface of the lens barrel body 50. The rotation detection sensor 60 is supported so as to face the inner peripheral surface of the operation ring 30.

  The motor 100 is disposed on the outer peripheral surface of the barrel main body 50. In this embodiment, a stepping motor is used. The motor 100 is electrically connected to the second flexible substrate 72 shown in FIG. A shaft 101 is directly connected to the motor 100. A lead screw portion 102 is formed on the other end side of the shaft 101, and the rotation axis of the motor 100 is a screw axis. A nut 103 is engaged with the lead screw portion 102.

  The rotation detection sensor 60 is used to detect the rotation direction, rotation amount, and rotation speed of the operation ring 30. In the present embodiment, two transmissive photo interrupters are used, and by detecting the passage of the convex detected portion 31 formed on the inner periphery of the operation ring 30, the rotation direction, the rotation amount, and the rotation amount of the operation ring 30 are detected. Detect rotation speed.

  The lens groups L1 to L4 are arranged along the optical axis L from the front to the rear of the lens barrel 10. The first and second lens groups L1 and L2 are supported by a first support frame 131 supported by the barrel main body 50. A shutter unit 134 for controlling a diaphragm and a shutter (both not shown) is disposed on the inner peripheral side of the barrel main body 50. A second support frame 132 is disposed at the rear end of the barrel main body 50. The second support frame 132 supports the third lens group L3. The third lens group L3 is located on the inner peripheral side of the joint ring 120 and is supported by the barrel main body 50.

  A third support frame 133 that supports the fourth lens unit L4 for focusing is disposed on the inner peripheral side of the mount unit 110. The third support frame 133 is connected to a nut 103 that meshes with a lead screw portion 102 provided integrally with the motor 100.

  When the operation ring 30 is rotated, the rotation detection sensor 60 detects the rotation direction, the rotation amount, and the rotation speed of the operation ring 30 by detecting the passage of the convex detected portion 31 of the operation ring 30 that passes through the recess 61. To do. A signal detected by the rotation detection sensor 60 is input to a microprocessor (not shown) mounted on the circuit board, and the motor 100 is driven according to the rotation direction, rotation amount, and rotation speed of the operation ring 30. Be controlled. Then, the lead screw portion 102 of the motor 100 converts the rotational motion of the motor 100 into a linear motion in the optical axis L direction. Depending on the amount of rotation of the motor 100, the third support frame 133 and the fourth lens group L4 connected to the nut 103 and the nut 103 are both guided along the optical axis L in a straight line.

  Next, the rotation detection sensor 60 and the sensor support members 80 and 90 that support the rotation detection sensor 60 will be described with reference to FIGS. FIG. 6 is a perspective view of the first sensor support member 80 and the rotation detection sensor 60 before the second sensor support member 90 is attached. FIG. 7 is a perspective view of the first sensor support member 80 and the rotation detection sensor 60 after the second sensor support member 90 is attached. FIG. 8 is a partial cross-sectional view showing a state in which the rotation detection sensor 60 is attached to the first sensor support member 80. FIG. 9 is a partial cross-sectional view after the second sensor support member 90 is attached.

  The rotation detection sensor 60 is directly attached to the first flexible substrate 71 by soldering. In the first flexible substrate 71, the attachment position 71 a to which the rotation detection sensor 60 is attached is formed thicker than the others so that the rotation detection sensor 60 can be easily pressed after being fitted into the first sensor support member 80. .

  As shown in FIG. 6, the first sensor support member 80 is an arc-shaped member, and is fixed to the lens barrel body 50 by screwing (see FIG. 4). Screw fixing holes 81a and 82a and fitting grooves 81b and 82b are formed in the first and second end portions 81 and 82, respectively. A protrusion 83 is formed at the center of the first sensor support member 80, and a through-hole 84 for fitting the rotation detection sensor 60 is formed in the protrusion 83.

  As shown in FIG. 7, the second sensor support member 90 is an arc-shaped member, and the protrusions 91 a and 92 b are inserted into the fitting grooves 81 b and 82 b of the first sensor support member 80, so that the first sensor The first flexible substrate 71 is sandwiched between the first sensor support member 80 and the support member 80. The first end 91 of the second sensor support member 90 is not formed with a screw hole, and does not overlap the first end 81 of the first sensor support member 80. On the other hand, the second end portion 92 of the second sensor support member 90 is formed with a screw-fastening hole 92a, which overlaps the second end portion 82 of the first sensor support member 80 and is screwed. (See FIG. 4). The second sensor support member 90 is formed with a pressing portion 90 a for pressing the first flexible substrate 71.

  In order to attach the rotation detection sensor 60 to the lens barrel body 50, first, the rotation detection sensor 60 attached to the first flexible substrate 71 is inserted into the through hole 84 of the first sensor support member 80 and loosely fitted. Next, the first sensor support member 80 is inserted in the X direction of FIG. 8, that is, from the front side of the lens barrel body 50 toward the rear, and is applied to the wall surface of the lens barrel body 50, and the hole portion a is fixed with a screw 52.

  After attaching the first sensor support member to the lens barrel body 50, the operation ring 30 is fitted from the front of the lens barrel body 50. As shown in FIGS. 8 and 9, in the present embodiment, in the radial direction, the peripheral wall surface 50 c of the portion of the barrel body 50 in which the shutter unit 134 is accommodated, that is, the outer circumferential surface of the barrel body 50, and the operation ring. The distance h1 from the surface facing the inner peripheral surface 30 to the inner peripheral side end of the detected part 31, the distance h2 from the peripheral wall surface 50c to the upper end 60b of the rotation detection sensor 60, and the first sensor instruction from the peripheral wall surface 50c. When the distance h3 to the inner peripheral bottom of the member 80 is set, the relationship is h1> h2> h3. Further, the depth l1 of the concave portion of the rotation detection sensor 60 is slightly shorter than the length l2 of the detected portion 31 (l1 <l2). For this reason, since the detected part 31 protruding to the inner peripheral side of the operation ring 30 does not interfere with the rotation detection sensor 60, the operation ring 30 can be easily fitted into the lens barrel body. Further, from the relationship of h2> h3, the rotation detection sensor 60 is guided to the through hole 84 without being detached from the first sensor support member 80, and is held in a state where it can advance and retreat in the radial direction.

  As shown in FIG. 9, the second sensor support member 90 is inserted in the X direction of FIG. As the second sensor support member 90 is inserted, the first flexible substrate 71 and the rotation detection sensor 60 penetrate in the Y direction, that is, from the peripheral wall surface 50c of the barrel main body 50 toward the inner peripheral surface of the operation ring 30. Guided by the hole 84 and pushed up, the recess 61 of the rotation detection sensor 60 faces the detected portion 31 and advances to a position where the passage of the detected portion 31 can be detected. Then, the protrusions 91 a and 92 b of the second sensor support member 90 are fitted into the fitting grooves 81 b and 82 b of the first sensor support member 80, and the first flexible substrate is interposed between the first sensor support member 80 and the first sensor support member 80. 71 is sandwiched. In this way, the second sensor support member 90 urges and fixes the rotation detection sensor 60 from the outer peripheral surface of the barrel main body 50 toward the inner peripheral surface of the operation ring 30. Thereafter, the first sensor support member 80 and the second sensor support member 90 are screwed with screws 51 as shown in FIG. After the substrate 35 is attached, the fixed frame 40 is attached and fixed with screws (not shown). Then, the front decoration board 43 is affixed to the fixed frame 40, and the exterior ring 20 is also attached.

  As described above, according to the lens barrel structure according to the present embodiment, there is no place where the exterior ring, the operation ring, and the fixed ring overlap at the same time, and only the operation ring is provided on the surface orthogonal to the optical axis direction. Since there is a surface on which the outer shape is formed, the diameter of the lens barrel can be reduced. In addition, a cylindrical outer shape of the lens barrel is formed by the outer ring, the operation ring, and the fixed ring, and the inside of the lens barrel is used for controlling the lens barrel, a lens group attached to the barrel main body, and the lens barrel. A space for accommodating the various control components is secured. As described above, in this embodiment, the radial direction of the ring forming the outer shape of the operation ring or the like and the space on the inner peripheral side are effectively used, and the diameter of the lens barrel can be reduced.

  In addition, by providing an arc-shaped sensor support member directly in the circumferential direction of the outer peripheral surface of the lens barrel body, it is not a shape that supports the rotation detection sensor on the entire outer periphery of the lens barrel body, but on a part of the outer periphery. Therefore, the diameter can be further reduced. Furthermore, since the rotation detection sensor is provided only on a part of the outer periphery, the diameter of the lens barrel can be reduced without the rotation detection sensor affecting the outer shape of the lens barrel.

  In addition, since the sensor support member supports the rotation detection sensor so as to face the inner peripheral surface of the operation ring, the rotation detection sensor can be easily supported. Further, since all the electronic components such as the rotation detection sensor are attached to the lens barrel body, all the electronic components are exposed when the fixed frame or the like constituting the outer shape of the lens barrel is removed. For this reason, it is easy to assemble even if the lens barrel has a small diameter.

DESCRIPTION OF SYMBOLS 10 Lens barrel 20 Exterior ring 30 Operation ring 30a 1st step part 30b 2nd step part 30f 3rd step part 40 Fixed ring 50 Lens barrel body 60 Rotation detection sensor (detection sensor)
71 1st flexible substrate 80 1st sensor support member 90 2nd sensor support member 100 Motor 110 Mount part L Optical axis L1-L4 Lens group

Claims (4)

A lens barrel body for holding the lens;
An exterior ring that is externally mounted on the lens barrel body;
An operation ring disposed on the outer periphery of the barrel main body and held rotatably in the circumferential direction with respect to the barrel main body;
A fixed ring fixed to the lens barrel body and holding the operation ring with the lens barrel body;
The outer ring, the operation ring, and the fixed ring overlap with each other only in the radial direction in the rotation axis direction, and the outer ring, the operation ring, and the fixed ring overlap three in the radial direction. There is no lens barrel structure in which an outer shape is formed only by the operation ring on a surface orthogonal to the optical axis direction.   An outer shape of the lens barrel is formed by the outer ring, the operation ring, and the fixed ring, and a control part for the lens barrel is accommodated in an inner space formed by the operation ring. The lens barrel structure according to claim 1. The operation ring has a first step portion formed with a different radial dimension on the lens barrel body side in the rotation axis direction and a second step formed with a different radial dimension on the stationary ring side. Having a step,
2. The lens according to claim 1, wherein the lens barrel main body is in contact with the first step portion and the stationary ring is in contact with the second step portion, and the operation ring is rotatably held. A lens barrel structure.   The first step portion and the second step portion are formed on the inner peripheral side of the operation ring, and the third step portion is formed on the outer peripheral side of the operation ring with a reduced radial dimension. The lens barrel structure according to claim 3, wherein the outer ring is disposed on an outer periphery of the third step portion.

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