JP2019023758A - Optical apparatus - Google Patents

Abstract

To provide an optical apparatus that can limit a relative rotation of two bayonet-connecting cylindrical members which is in a predetermined angel range or higher than the range.SOLUTION: The optical apparatus 3 includes: a first tube 40; a second tube 50, which can move with respect to the first tube 40 in the optical axis direction; and a third tube 60, which can rotate and cannot move in the optical axis direction in a predetermined angle range with respect to the second tube 50. The attachment structure for attaching the third tube 60 to the second tube 50 has a regulation unit 52 for regulating the angle of rotation of the third tube 60 with respect to the second tube 50 within the predetermined angle range. The first tube 40 has a reinforcement unit 45 for reinforcing the regulation by the regulation unit 52.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an optical apparatus.

A bayonet structure is known as a method for incorporating two cylindrical members so as to rotate without moving in the optical axis direction (see Patent Document 1).
The bayonet structure couples two cylindrical members by rotating each other in a first direction. However, even once coupled, the bayonet coupling is released when the two cylindrical members are rotated in the second direction opposite to the first direction. For this reason, in the conventional bayonet structure, another part such as a snap fit portion is provided in order to limit the rotation in the first direction of the two cylindrical members once joined.

JP 4011-180554 A

  However, the snap-fit portion has a problem that it may not be able to restrict relative rotation beyond a predetermined angle range in the two cylindrical members that are elastically deformed when a force is applied and the bayonet couples.

  One embodiment of the present invention includes a first tube, a second tube that is movable in the optical axis direction with respect to the first tube, and a light that is rotatable with respect to the second tube within a predetermined angle range. A third cylinder that is immovably attached in the axial direction, and the attachment structure for attaching the third cylinder to the second cylinder has a rotation angle of the third cylinder with respect to the second cylinder within the predetermined angle range. The first cylinder is an optical device having a reinforcing part that reinforces the restriction by the restricting part.

1 is an overall view of a camera including a lens barrel as an example of an optical apparatus. It is sectional drawing of a lens-barrel. It is a disassembled perspective view of each cylinder part of a lens barrel. It is a side view of the optical axis direction front-end | tip part of a 1st rectilinear advance cylinder. It is a side view of the part of the 3rd rotation cylinder, the 2nd rectilinear advance cylinder, and the 1st rectilinear advance cylinder. FIG. 6 is a cross-sectional view taken along line XX in FIG. 5. FIG. 6 is a YY sectional view of FIG. 5. It is a figure explaining the assembly method of a 3rd rotation cylinder and a 2nd rectilinear advance cylinder. FIG. 9 is a diagram in which the third rotating cylinder is relatively moved in the minus direction of the optical axis with respect to the second rectilinear cylinder from the state of FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the subject side of the optical axis OA will be described as the optical axis OA plus side, and the side attached to the camera 1 will be described as the optical axis OA minus side. FIG. 1 is an overall view of a camera 1 including a lens barrel 3 as an example of an optical apparatus.

The camera 1 is a digital single-lens reflex camera with interchangeable lenses. As shown in FIG. 1, the camera 1 includes a camera body 2 and a lens barrel 3 that can be attached to and detached from the camera body 2.
The camera body 2 includes an image sensor (not shown) that captures a subject image formed by the lens barrel 3. Further, the camera body 2 includes a mount portion (not shown) in which the lens barrel 3 can be engaged.

The lens barrel 3 is a zoom lens that can continuously change the focal length.
The lens barrel 3 includes a plurality of lens groups serving as a photographing optical system and a plurality of cylinders (described later) that hold the lens groups in a cylindrical housing.
The lens barrel 3 can be attached to the camera body 2 by fitting the coupling portion of the lens barrel 3 into the mount portion of the camera body 2 and rotating it in a predetermined direction about the optical axis OA.

Next, the configuration of the lens barrel 3 will be described. FIG. 2 is a cross-sectional view of the lens barrel 3. FIG. 3 is an exploded perspective view of each lens barrel 3.
As shown in FIGS. 2 and 3, the lens barrel 3 includes a fixed barrel 10, a second rotary barrel 20, a first rotary barrel 30, a first rectilinear barrel 40, a second rectilinear barrel 50, A three-turn cylinder 60.

(Fixed cylinder 10)
The fixed cylinder 10 is a cylindrical member that becomes the base of the lens barrel 3. The fixed cylinder 10 is provided with a coupling portion with the camera 1 at the end on the minus side of the optical axis OA, and includes a first rectilinear groove 11 and a cam groove 13 as shown in FIG.

  The first rectilinear groove 11 is a through groove that penetrates the fixed cylinder 10 and is linearly formed in a direction along the optical axis OA. The first rectilinear groove 11 is a groove that linearly guides a first protrusion 41 (described later) of the first rectilinear cylinder 40. The first rectilinear grooves 11 are provided at three locations at equal intervals in the circumferential direction of the fixed cylinder 10.

  The cam groove 13 is a groove that guides the cam follower 31 of the first rotating cylinder 30 along the circumferential direction. The cam grooves 13 are provided at three locations at equal intervals in the circumferential direction of the fixed cylinder 10. Each cam groove 13 is formed in a substantially curved shape with the same shape in the direction along the optical axis OA in the fixed cylinder 10.

(Second rotating cylinder 20)
The second rotating cylinder 20 is a cylindrical member that is disposed on the outer peripheral side of the fixed cylinder 10 and is rotatable relative to the fixed cylinder 10 and is restricted from moving in the direction along the optical axis OA. is there.
The second rotating cylinder 20 includes a first cam groove 21 and a second cam groove 22 (see FIG. 3). A zoom ring (not shown) provided on the outer peripheral portion of the lens barrel 3 and operated by the operator is provided on the outer peripheral surface of the second rotating cylinder 20. When the photographer performs an operation of rotating the zoom ring, the second rotary cylinder 20 rotates clockwise or counterclockwise in conjunction with this operation. The zoom ring may be disposed on the outer peripheral surface of the second rotating cylinder 20 and may be connected via a connecting member or the like.

The first cam groove 21 is a groove that drives a cam follower 43 (described later) of the first rectilinear cylinder 40 in a direction along the optical axis OA. When the second rotating cylinder 20 rotates, the cam follower 43 is driven in the direction along the optical axis OA by the first cam groove 21 of the second rotating cylinder 20.
Therefore, the first rectilinear cylinder 40 moves in the direction along the optical axis OA in a state where the first protrusion 41 is restricted from rotating in the circumferential direction by the first rectilinear groove 11.
The first cam grooves 21 are provided at three locations at equal intervals in the circumferential direction of the second rotating cylinder 20. Each first cam groove 21 is formed in the same shape in the direction along the optical axis OA.

The second cam groove 22 is a groove that drives a protrusion 32 of the first rotating cylinder 30 to be described later in the circumferential direction. When the second rotating cylinder 20 rotates, the protrusion 32 is driven in the circumferential direction by the second cam groove 22 of the second rotating cylinder 20.
Therefore, in the first rotating cylinder 30, the cam follower 31 is guided along the cam groove 13 of the fixed cylinder 10. Thereby, the first rotating cylinder 30 moves in the direction along the optical axis OA while rotating in the circumferential direction.
The second cam grooves 22 are provided at three locations at equal intervals in the circumferential direction of the second rotating cylinder 20. Each second cam groove 22 is formed in the same shape in the direction along the optical axis OA.

(First rotating cylinder 30)
The first rotating cylinder 30 is a cylindrical member disposed on the inner diameter side of the fixed cylinder 10. The first rotating cylinder 30 includes a cam follower 31, a protrusion 32, and a cam groove 33.

  The cam follower 31 is a member that engages with the cam groove 13 of the fixed cylinder 10. The cam followers 31 are arranged at three locations at equal intervals in the circumferential direction on the outer peripheral portion of the first rotating cylinder 30.

  The protrusion 32 is a member that engages with a second cam groove 22 of the second rotating cylinder 20 described later. The protrusion 32 is formed integrally with the cam follower 31 at the upper part of the cam follower 31. Accordingly, the protrusions 32 are arranged at three locations at equal intervals in the circumferential direction on the outer peripheral portion of the first rotating cylinder 30, as with the cam follower 31.

The cam groove 33 is a groove that guides a cam follower 51 of a second rectilinear cylinder 50 described later along the circumferential direction. When the first rotating cylinder 30 moves straight while rotating, the second rectilinear cylinder 50 that engages with the cam groove 33 of the first rotating cylinder 30 via the cam follower 51 is guided by a convex portion 45 to be described later and the optical axis OA. Move in the direction along
The cam grooves 33 are provided at three locations at equal intervals in the circumferential direction of the first rotating cylinder 30. Each cam groove 33 is formed in the same shape in the direction along the optical axis OA.

(First straight cylinder 40)
FIG. 4 is a side view of the front end portion of the first rectilinear cylinder 40 in the optical axis OA direction. FIG. 5 is a side view of portions of the third rotating cylinder 60, the second rectilinear cylinder 50, and the first rectilinear cylinder 40 in the lens barrel 3. FIG. 6 is a cross-sectional view taken along line XX in FIG. 7 is a cross-sectional view taken along line YY of FIG. FIG. 8 is a view for explaining an assembly method of the third rotating cylinder 60 and the second rectilinear cylinder 50. FIG. 9 is a diagram in which the third rotating cylinder 60 is moved relative to the second rectilinear cylinder 50 in the minus direction of the optical axis OA from the state of FIG.

The first rectilinear cylinder 40 is a cylindrical member that can move linearly relative to the fixed cylinder 10 in the direction along the optical axis OA.
The first rectilinear cylinder 40 includes a first protrusion 41, a cam follower 43, and a convex portion 45.
The first protrusion 41 is a plate-like member that engages with the first rectilinear groove 11 of the fixed cylinder 10.
The first protrusion 41 moves along the first rectilinear groove 11 while passing through the first rectilinear groove 11. The first protrusions 41 are arranged at three locations at equal intervals in the circumferential direction on the outer peripheral portion of the first rectilinear cylinder 40.

  The cam follower 43 is a member that engages with the first cam groove 21 of the second rotating cylinder 20. The cam follower 43 is formed integrally with the first protrusion 41 at the upper part of the first protrusion 41. Accordingly, the cam followers 43 are arranged at three locations at equal intervals in the circumferential direction on the outer peripheral portion of the first rectilinear cylinder 40, as with the first protrusions 41.

  The convex portion 45 is a protrusion that extends in the direction of the optical axis OA on the outer periphery of the first rectilinear cylinder 40. As shown in a cross section in FIG. 7B, the convex portion 45 is trapezoidal in the cross section orthogonal to the optical axis OA, and the side surface is inclined.

(Second straight cylinder 50)
The second rectilinear cylinder 50 is disposed on the outer peripheral side of the first rectilinear cylinder 40 and between the outer peripheral surface of the first rectilinear cylinder 40 and the inner peripheral surface of the third rotating cylinder 60.
The second rectilinear cylinder 50 is a cylindrical member that can move linearly relative to the first rectilinear cylinder 40 in the direction along the optical axis OA direction.
The second rectilinear cylinder 50 includes a cam follower 51 and a snap fit portion 52.
The cam follower 51 is a member that engages with the cam groove 33 of the first rotating cylinder 30. The cam followers 51 are arranged at three locations at equal intervals in the circumferential direction on the outer peripheral portion of the second rectilinear cylinder 50.

  As shown in FIG. 8, the snap fit portion 52 is formed by providing a U-shaped through portion 55 extending in the optical axis OA direction on the outer periphery of the second rectilinear cylinder 50. The snap fit portion 52 has a free end on the optical axis OA minus side and a fixed end on the OA plus side that is fixed to a portion where the through portion 55 of the second rectilinear cylinder 50 is not formed.

As shown in FIG. 6, in the snap fit portion 52, the first portion 52a on the free end side protrudes to the outer diameter side than the second portion 52b on the fixed end side. That is, the first portion 52a is thicker in the radial direction than the second portion 52b.
In a state where the first rectilinear cylinder 40 is not arranged inside the second rectilinear cylinder 50, the snap fit portion 52 can be elastically deformed, and as shown by a dotted line in FIG. 6, the first portion 52a on the free end side. The second portion 52b can be bent and pressed into the inner diameter side of the first portion 52a by pressing toward the inner diameter side.
When viewed from the optical axis OA direction, the snap fit portion 52 includes an inner peripheral surface 58, an outer peripheral surface 59, a first side surface 53 and a second side surface 57 extending in a substantially radial direction, as shown in FIG. And a tapered portion 54 provided between the inner peripheral surface 58 and the first side surface 53. That is, the cross section of the snap fit portion 52 of the second rectilinear cylinder 50 in the direction perpendicular to the optical axis OA is not a rectangle but a pentagon. The first side surface 53 is a surface on the rear side of the second side surface 57 in the rotation direction R1 at the time of snap fitting of the third rotating cylinder 60 described later.

Further, a tapered portion 72 is also provided at an inner diameter side end portion of the side surface 71 facing the first side surface 53 and the through portion 55 of the snap fit portion 52 in the second rectilinear cylinder 50.
The trapezoidal shape of the convex portion 45 of the first rectilinear cylinder 40 corresponds to the shape of the space between the taper portion 72 and the taper portion 54 on the radially inner side in the penetrating portion 55, and the convex portion 45 has an inclined surface. It arrange | positions so that the taper part 54 and the taper part 72 of the snap fit part 52 may contact | abut.
As shown by a dotted line in FIG. 6, the convex portion 45 is provided with a predetermined length in the optical axis OA direction, and the taper portion 54 and the taper portion 72 of the snap fit portion 52 also have a predetermined length in the optical axis OA direction. It is provided. This predetermined length is a length at which the convex portion 45, the tapered portion 54, and the tapered portion 72 are always in contact with each other even when the third rotating cylinder 60 moves relative to the first rectilinear cylinder 40. .

(Third rotating cylinder 60)
The third rotating cylinder 60 is a cylinder that is attached to the outer periphery of the second rectilinear cylinder 50. A circumferential groove B for engaging the second rectilinear cylinder 50 with the bayonet is formed on the inner peripheral surface of the third rotating cylinder 60. The circumferential groove B has a first region extending along the circumferential direction and a second region formed continuously from one end of the first region and extending along the optical axis OA direction. The second region of the circumferential groove B is formed up to the rear end of the third rotating cylinder 60.
As shown in FIG. 7, the third rotating cylinder 60 is a cylindrical body. By providing a stepped portion (end surface 63) on the inner diameter side, the thick portion 61 (the radial thickness r <b> 1) and the radial direction from the thick portion. Is provided with a thin portion 62 (thickness r2). Due to the difference in thickness, an end face 63 is formed at the boundary between the thick portion 61 and the thin portion 62. Moreover, the thick part 61 and the thin part 62 are continuously formed along the circumferential direction.
The third rotating cylinder 60 advances straight as the second rectilinear cylinder 50 goes straight due to the bayonet coupling between the protrusion A and the circumferential groove B. When the third rotating cylinder 60 moves straight, the first b lens group Lb moves straight due to the engagement between the cam groove C and the cam pin of the first b lens group Lb.
The 1b lens group Lb is also moved straight by SWM (ultrasonic motor, not shown) during the focusing operation. At this time, the third rotating cylinder 60 is rotationally driven in the circumferential direction by the rectilinear movement of the 1b lens group Lb and the engagement with the cam groove C and the cam pin.

(Bayonet combination)
Next, a bayonet coupling method between the second rectilinear cylinder 50 and the third rotating cylinder 60 will be described.
As shown in FIG. 8, the third rotating cylinder 60 is placed on the tip of the second rectilinear cylinder 50 in the optical axis OA direction, and the outer wall of the second rectilinear cylinder 50 is covered with the thick portion 61 covering the snap fit portion 52. Deploy. At this time, the protrusion A protruding from the outer peripheral surface of the second rectilinear cylinder 50 engages with the second region of the circumferential groove B of the third rotating cylinder 60.

  The third rotary cylinder 60 is moved relative to the second rectilinear cylinder 50 in the minus direction of the optical axis OA (the direction of the arrow R1 in FIG. 8). Then, the protrusion A of the second rectilinear cylinder 50 moves from the second region of the circumferential groove B to the first region. As a result, the third rotating cylinder 60 is bayonet-coupled to the second rectilinear cylinder 50. Further, as shown in the dotted line in FIG. 6 and FIG. 7A, the first portion 52a of the snap fit portion 52 is pushed by the thick portion 61, elastically deformed, and moves to the inner diameter side (arrow R2). ).

  When the third rotating cylinder 60 is rotated in the direction of arrow R3 in FIG. 7A in the state of FIG. 7A, the thick portion 61 of the third rotating cylinder 60 gets over the snap fit portion 52. When the thin portion 62 is rotated until it comes to the outer diameter side of the snap fit portion 52, the snap fit portion 52 returns to the direction of the arrow R4 by the spring force as shown in FIG.

At this stage, when the third rotating cylinder 60 rotates in the opposite direction to R3, the end face 63 comes into contact with the second side surface 57 of the snap fit portion 52, and the circumferential direction of the third rotating cylinder 60 in the direction opposite to the arrow R3 is obtained. Rotation is easily regulated.
That is, in the snap fit portion 52, the third rotating cylinder 60 is detached from the second rectilinear cylinder 50 until the first rectilinear cylinder 40 described below is incorporated after the second rectilinear cylinder 50 and the third rotating cylinder 60 are incorporated. Is simply prevented.

  However, since the first portion 52a of the snap fit portion 52 is a free end, it moves in the radial direction and the circumferential direction when a force is applied. For this reason. When a certain amount of force is applied, the bayonet coupling between the third rotating cylinder 60 and the second rectilinear cylinder 50 may be released.

  Therefore, in the present embodiment, the first rectilinear cylinder 40 is further aligned with the convex portion 45 of the first rectilinear cylinder 40 and the penetrating portion 55 of the second rectilinear cylinder 50 from the minus direction of the optical axis OA. As shown in FIG. 7B, the convex portion 45 is formed by the tapered portion 72 and the tapered portion 54 on the inner diameter side of the through portion 55. Fit into space.

Thereby, since the inner peripheral surface 58 of the snap fit portion 52 is fixed by the outer peripheral surface adjacent to the convex portion 45 in the first rectilinear cylinder 40, the snap fit portion 52 does not bend in the radial direction.
Moreover, since the taper part 54 of the snap fit part 52 is fixed by the side surface of the convex part 45, the snap fit part 52 does not move in the circumferential direction.

(Effect of this embodiment)
According to the present embodiment, the third rotating cylinder 60 moves in the circumferential direction with respect to the second rectilinear cylinder 50 in the range on the arrow R3 side from the position where the end surface 63 contacts the second side surface 57 of the snap fit portion 52. Is possible.
However, since the snap fit portion 52 is fixed so as not to move in the radial direction and the circumferential direction, the third rotary cylinder 60 has an end surface 63 that comes into contact with the second side surface 57 of the snap fit portion 52. No further rotation in the direction opposite to the arrow R3.
Therefore, the bayonet coupling between the third rotating cylinder 60 and the second rectilinear cylinder 50 is not easily released. Thereby, the effect of shortening the coupling length of the circumferential groove B and the protrusion A related to the bayonet coupling and contributing to the downsizing of the lens barrel 3 is also obtained.

(Deformation)
The present invention is not limited to the above-described embodiment, and various modifications and changes as described below are possible, and these are also within the scope of the present invention.
(1) In the present embodiment, the first rectilinear cylinder 40, the second rectilinear cylinder 50, and the third rotary cylinder 60 are arranged from the inner diameter side in this order, but the arrangement order is not limited thereto, and the arrangement order may be reversed.
(2) Another member may be disposed between the first rectilinear cylinder 40 and the second rectilinear cylinder 50. Further, another member may be disposed between the second rectilinear cylinder 50 and the third rotating cylinder 60.

(3) The first rectilinear cylinder 40 may be fixed with respect to the optical axis direction, or may be linearly moved and rotated.
(4) Moreover, the 3rd rotation cylinder 60 may be fixed to the optical axis direction with respect to the 1st rectilinear advance cylinder 40, and may move rectilinearly.
Moreover, in this embodiment, the 1st rotation cylinder 30 has the cam follower 31 and the protrusion 32 on the outer peripheral surface, respectively. In addition, the cam follower 31 and the protrusion 32 that are integral metal cut products are fixed to the outer peripheral surface of the first rotating cylinder 30. Not limited to this, the first rotating cylinder, the cam follower, and the protrusion may be integrally formed. Alternatively, the cam follower and the protrusion may be prepared separately and fixed sequentially to the outer peripheral surface of the first rotating cylinder. Furthermore, the first rotating cylinder and the cam follower may be integrally molded, and the protrusion may be fixed to the cam follower.
(5) In the present embodiment, the lens barrel 3 has been described as a zoom lens capable of continuously changing the focal length. Not limited to this, the lens barrel 3 may be a single focus lens having a fixed focal length.
(6) In this embodiment, the camera 1 including the lens barrel 3 has been described as a digital single-lens reflex camera with interchangeable lenses. However, the present invention is not limited to this, and the present invention can also be applied to a mirrorless interchangeable-lens camera, a lens-integrated digital camera, a video camera, a portable terminal, and the like.
In addition, although embodiment and a deformation | transformation form can also be used combining suitably, detailed description is abbreviate | omitted. Further, the present invention is not limited to the embodiment described above.

  OA: optical axis, 1: camera, 2: camera body, 3: lens barrel, 10: fixed barrel, 11: first rectilinear groove, 13: cam groove, 20: second rotating cylinder, 21: first cam groove , 22: second cam groove, 30: first rotating cylinder, 31: cam follower, 32: protrusion, 33: cam groove, 40: first straight cylinder, 41: first protrusion, 43: cam follower, 45: convex portion 50: second straight cylinder, 51: cam follower, 52: snap fit portion, 52a: first portion, 52b: second portion, 53: first side surface, 54: taper portion, 55: penetration portion, 57: second Side surface, 58: inner peripheral surface, 59: outer peripheral surface, 60: third rotating cylinder, 61: thick portion, 62: thin portion, 63: end surface, 71: side surface, 72: taper portion

Claims (1)

A first tube;
A second cylinder movable in the optical axis direction with respect to the first cylinder;
A third cylinder attached to the second cylinder so as to be rotatable and immovable in the optical axis direction within a predetermined angle range;
The mounting structure for attaching the third cylinder to the second cylinder has a restricting portion that restricts a rotation angle of the third cylinder with respect to the second cylinder within the predetermined angle range.
The first cylinder is an optical apparatus having a reinforcing portion that reinforces the restriction by the restricting portion.

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