JPH1068860A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel capable of shortening the length of a zoom cam ring as much as possible while securing strength in the structure of a zoom cam ring and the positional accuracy of each cam groove, capable of being made small in size and light in weight as a whole. SOLUTION: A cam groove 5a is formed on the outside peripheral part γof the zoom cam ring 5, and the cam grooves 5b and 5c are formed on the inside peripheral part α of the ring 5. The cam grooves 5a, 5b and 5c are formed in a superposed or an adjacent state in the radial direction of the ring 5. Consequently, the grooves 5a, 5b and 5c can be freely laid out on the parts αand γwhile keeping the strength of the ring 5, so that the length Q of the ring 5 is shortened and the lens barrel 1 is made compact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel having a structure in which a lens group is moved by a predetermined amount using a cam barrel during zooming and / or focusing.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing an example of a conventional zoom lens barrel. FIG. 4 is a development view showing a state where a zoom cam ring of a conventional zoom lens barrel is developed in a range of 360 degrees. In FIG. 4, the pins 9, 10, 1
2, two pins 1 are provided at 180-degree symmetrical positions. In FIG. 3, the illustration of one of the pins 9, 10, 11 is omitted.

The zoom lens barrel 1 includes a first lens group G
1, a second lens group G2, a third lens group G3,
A fourth lens group G4, a lens supporting frame 12, supporting cylinders 7, 8, a sliding cylinder 6, which respectively support them, and an inner cylindrical portion 2c
A fixed cylinder 2 composed of an outer cylinder 2b and a zoom cam ring 5 rotatably fitted between the inner cylinder 2c and the outer cylinder 2b.
And a zoom operation ring 4 for rotating the zoom cam ring 5 and a focus operation ring 3 for driving the lens support frame 12. At the rear end of the fixed barrel 2, a mount 2a for mounting the zoom lens barrel 1 on a flange portion of a camera body (not shown) is provided.

The outer cylinder portion 2b is a portion for supporting a focus operation ring 3 and a zoom operation ring 4 to be described later so as to be rotatable about the optical axis I. An engagement portion 21a for rotatably attaching the focus ring 3 is formed on the inner peripheral surface of the outer cylindrical portion 2b. An engaging portion 21b for rotatably attaching the zoom operation ring 4 is provided on an outer peripheral surface of the outer cylindrical portion 2b, and the engaging portion 21 is provided so that the zoom operation ring 4 is rotatable.
b, and a relief peripheral groove 2g formed around the engaging portion 21b. Mount part 2 of outer cylinder part 2b
The end on the side a is bent at a substantially right angle toward the inner cylinder 2c,
It is connected to the outer peripheral surface of the inner cylindrical portion 2c.

[0005] The focus operation ring 3 is a member that is operated when performing focus adjustment for forming an image of a subject on an imaging surface (not shown). The engaging portion 2 is provided on the outer peripheral surface of the focus operation ring 3.
An engagement portion 31a that slidably engages with the lens 1a is formed. A key groove 31b that engages with a key protrusion 12b described later is formed on the inner peripheral surface of the focus operation ring 3 in parallel with the optical axis I. Is formed.

[0006] The zoom operation ring 4 is a member that is operated when photographing while continuously changing the focal length. An engaging portion 41b that slidably engages with the engaging portion 21b is provided on the inner peripheral surface of the zoom operation ring 4, and the escape peripheral groove 2 protrudes from the inner peripheral surface.
g, and a projection 41a that engages with the notch 5d of the zoom cam ring 5 is provided.

The inner cylinder portion 2c is a portion for supporting a zoom cam ring 5 to be described later rotatably about the optical axis I and for holding a sliding cylinder 6 to be described later movably in the optical axis I direction. . Engaging portions 22a and 22b for rotatably supporting the zoom cam ring 5 are formed on the outer peripheral surface of the inner cylindrical portion 2c. In addition, as shown in FIG.
Straight running groove 2 for guiding pins 9, 10, 11 described below
d, 2e, and 2f penetrate through the inner cylindrical portion 2c, and the optical axis I
And are formed in parallel. The outer peripheral surface of the inner cylindrical portion 2c is in contact with the inner peripheral surface of the zoom cam ring 5, and
The inner peripheral surface of the inner cylindrical portion 2c is
In a state of contact with the outer peripheral surface of the sliding cylinder 6 described later, the sliding cylinder 6
Is fitted.

[0008] The zoom cam ring 5 has straight grooves 2d, 2e, 2
The driving force to be driven along f
It is a member to be added to 1. In the zoom cam ring 5,
As shown in FIG. 4, a cam groove 5a penetrating the zoom cam ring 5 and formed linearly in a direction intersecting the optical axis I,
Cam grooves 5b and 5c that penetrate the zoom cam ring 5 and are curved in a direction intersecting the optical axis I, and a notch 5d formed at an end of the zoom cam ring 5 on the mount 2a side.
And engaging portions 51a and 51b that slidably engage with the engaging portions 22a and 22b.

The sliding cylinder 6 is a member for supporting the fourth lens group G4 and for holding the later-described supporting cylinders 7 and 8 so as to be movable in the direction of the optical axis I. Escape grooves 6a, 6b through which pins 10 and 11,
A pin mounting portion 61a for mounting a pin 9 described later on the outer peripheral surface of the sliding cylinder 6, a male helicoid screw portion 6c formed on the outer peripheral surface on the distal end side of the sliding cylinder 6, A lens attachment portion 61b formed on the inner peripheral portion of the cylinder 6 on the mount portion 2a side for attaching the fourth lens group G4 is provided. The sliding cylinders 7 and 8 are fitted with the inner peripheral surface of the sliding cylinder 6 in contact with the outer peripheral surfaces of the sliding cylinders 7 and 8 described below.

The pin 9 is a pin for moving the sliding cylinder 6 in the direction of the optical axis I by moving along the straight groove 2d and the cam groove 5a. The pin 9 protrudes from the outer peripheral surface of the sliding cylinder 6 and is movably fitted along the straight groove 2d and the cam groove 5a.

The lens support frame 12 includes a first lens group G1.
It is a frame for supporting. The lens support frame 12 has a flange portion 12d that protrudes from the inner peripheral portion of the lens support frame 12 and is folded in a direction parallel to the optical axis I, and is formed on the inner peripheral portion of the flange portion 12d. A lens mounting portion 12a for mounting the lens group G1, a key protruding portion 12b formed on the outer peripheral portion of the lens support frame 12 and engaging with the key groove 31b, and a key protruding portion 12b formed on the inner peripheral portion of the lens support frame 12. A female helicoid screw portion 12c meshing with the male helicoid screw portion 6c of the sliding cylinder 6 is provided.

The sliding cylinders 7 and 8 are members for supporting the second lens group G2 and the third lens group G3, respectively. The sliding cylinders 7 and 8 have the same structure except that the supporting lens groups are different. Hereinafter, the sliding cylinder 7 and the pin 10 will be mainly described. A pin mounting portion 71a for mounting a pin 10 described later is formed on the outer peripheral surface of the sliding cylinder 7, and the second lens group G2 is formed on the inner peripheral part of the sliding cylinder 7.
The lens mounting portion 71b for mounting the lens is formed.

The pins 10 and 11 are respectively provided in the straight grooves 2e and 2e.
By moving along 2f and the cam grooves 5b and 5c,
These pins are used to move the support cylinders 7 and 8 in the direction of the optical axis I. The pin 10 protrudes from the outer peripheral surface of the sliding cylinder 7 and is movably fitted along the relief groove 6a, the rectilinear groove 2e, and the cam groove 5b.

Next, the operation of the conventional lens barrel will be described separately for a zooming operation and a focusing operation. (Zooming operation) When the photographer rotates the zoom operation ring 4, the projection 41a protruding from the zoom operation ring 4 pushes the notch 5d of the zoom cam ring 5 in the direction of the arrow shown in FIG. Rotate around I. When the zoom cam ring 5 rotates, the pin 9 is pushed by the side surface of the cam groove 5a while moving in contact with the side surface. The pin 9 receives a driving force at a contact portion with the side surface of the cam groove 5a in a direction substantially orthogonal to the cam groove 5a, so that the pin 9
It moves along the straight groove 2d. As a result, the sliding cylinder 6 to which the pin 9 is attached moves in the optical axis I direction while being in contact with the inner peripheral surface of the inner cylinder portion 2c. Sliding barrel 6 and lens support frame 1
2 is a male helicoid thread 6c and a female helicoid thread 1
Linked together by 2c. For this reason, when the sliding cylinder 6 moves, the lens support frame 12
It is moved in the direction of the optical axis I by being guided by the key groove 31b engaging with b.

The rotation of the zoom cam ring 5 causes the side surfaces of the cam grooves 5b and 5c to be brought into contact with the pins 10 and 1 respectively.
By pressing 1, the pins 10, 11 move along the straight grooves 2e, 2f by the driving force at the contact portions between the side surfaces of the cam grooves 5b, 5c and the pins 10, 11 respectively. as a result,
Support cylinders 7, 8 with pins 10, 11 respectively attached
Moves in the direction of the optical axis I while contacting the inner peripheral surface of the sliding cylinder 6 by the same operation. By the above operation, the first lens group G1, the second lens group G2, and the third lens group G
The zooming operation is performed by moving the third and fourth lens groups G4 in the direction of the optical axis I. The focal length can be adjusted by adjusting the rotation direction and the rotation angle of the zoom operation ring 4.

(Focusing operation) When the photographer rotates the focus operation ring 3, the side surface along the longitudinal direction of the key groove 31b pushes the key projection 12b, and the lens support frame 12
Attempts to rotate about the optical axis I. Lens support frame 1
2 is a male helicoid thread 6c and a female helicoid thread 1
Although connected to the sliding cylinder 6 by 2c, the pin 9 provided on the sliding cylinder 6 allows only movement along the straight groove 2d. For this reason, the sliding cylinder 6 cannot rotate, and the lens support frame 12 has the female helicoid screw portion 12c.
While rotating with the male helicoid screw portion 6c of the sliding cylinder 6, it rotates in the direction of the optical axis I. By the above operation, the first lens group G1 moves in the optical axis I direction,
A focusing operation is performed. The focus adjustment can be performed by adjusting the rotation direction and the rotation angle of the focus operation ring 3.

[0017]

The cam grooves 5a, 5b, 5 are formed in the zoom cam ring 5 of the conventional zoom lens barrel 1 described above.
When forming c, it was necessary to consider whether or not the formed zoom cam ring 5 had sufficient structural strength. For this reason, in the conventional zoom cam ring 5, the cam grooves 5a and 5a do not cross each other and are sufficiently spaced from each other.
b, 5c were formed. However, if the cam grooves 5a, 5b, 5c spaced apart from each other are formed in the zoom cam ring 5, as shown in FIGS. 3 and 4, the length P of the zoom cam ring 5 in the direction of the optical axis I becomes longer. As a result, the length of the lens barrel 1 increases, and the zoom lens barrel 1 cannot be made compact and lightweight.

Therefore, it is desirable to shorten the length P of the zoom cam ring 5 by arranging the cam grooves 5a, 5b, 5c as close as possible while maintaining the structural strength of the zoom cam ring 5. However, as shown in FIG. 4, the cam grooves 5a,
5b and 5c are provided to be inclined with respect to the direction of the optical axis I of the zoom cam ring 5, and the cam grooves 5b and 5c are arranged close to each other because they are curved cam grooves. Was difficult. Further, the pins 9, 10, and 11 need to be sufficiently spaced from each other due to the structural limitation of the zoom lens barrel 1. There were limits to placement.

On the other hand, the cam grooves 5a, 5b and 5c may be formed entirely or partially in different members, so that the degree of freedom in layout can be ensured. However, if the cam grooves 5a, 5b, 5c are formed in different members, the positional accuracy between the respective cam grooves 5a, 5b, 5c cannot be maintained at a high processing and assembling level, and the members may not be able to be maintained between the members. Causes a shift in the focal point or the like. Therefore,
The positional accuracy between the cam grooves 5a, 5b, 5c and the like are desired to be solved by forming them in one zoom cam ring 5. However, due to the above-mentioned limitation of the layout of the cam grooves 5a, 5b, 5c, the zoom cam ring is limited. 5 had become longer.

An object of the present invention is to reduce the length of the zoom cam ring as much as possible while ensuring the structural strength of the zoom cam ring and the positioning accuracy of each cam groove, and to reduce the size and weight of the entire lens barrel. An object of the present invention is to provide a lens barrel capable of achieving the following.

[0021]

The present invention solves the above-mentioned problems by the following means. In addition, in order to make it easy to understand, description is given with reference numerals corresponding to the embodiment of the present invention, but the present invention is not limited to this. That is, the first aspect of the present invention provides a photographing optical system (G1, G1
2, G3, G4) to move at least a part (G1, G2) in the direction of the optical axis (I).
b, 5c), the lens barrel (1) including a cam barrel (5) provided with an outer peripheral cam (5a) provided on an outer circumference (γ) and an inner circumference (α). The inner peripheral cams (5b, 5c) provided on the cam cylinder and the outer peripheral cam and the inner peripheral cam are not penetrated at least at positions where they are arranged so as to overlap or approach at least in the radial direction of the cam cylinder. And an intermediate separating portion (β) provided for the purpose.

According to a second aspect of the present invention, there is provided a lens barrel including a cam barrel having a plurality of cams formed for moving at least a part of the photographing optical system in the optical axis direction, wherein the cam barrel has a radial shape. An outer diameter side layer (γ), an intermediate layer (β), and an inner diameter side layer (α) in this order from the outer diameter side, and the plurality of cams are provided on the outer diameter side layer and the inner diameter side layer. It is characterized by having.

[0023] The invention of claim 3 is the invention of claim 1 or claim 2.
Wherein the plurality of cams formed in the cam barrel are groove cams, convex cams, or a combination thereof.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, an embodiment of the present invention will be described in more detail with reference to the drawings and the like. FIG. 1 is a sectional view of a zoom lens barrel according to an embodiment of the present invention. FIG. 2 is a developed view showing a state where the zoom cam ring of the zoom lens barrel according to the embodiment of the present invention is developed in a range of 360 degrees. In FIG. 2, the pins 10, 11,
In FIG. 1, two pins 14 and 15 are provided at 180-degree symmetrical positions.
Illustrations of 1 and 15 are omitted. In the following description, the same members as those of the zoom lens barrel 1 described in the related art will be denoted by the same reference numerals, and detailed description of those portions will be omitted.

As shown in FIG. 1, cam grooves 5b and 5c are formed on the inner peripheral surface of the zoom cam ring 5, and a cam groove 5a and pins 10 and 11 are formed on the outer peripheral surface of the zoom cam ring 5. Tool holes 5e and 5f for attaching to the pin attaching portions 71a and 81a, respectively, are provided. Zoom cam ring 5
No cam grooves 5a, 5b, 5c are formed in an intermediate portion (thickness β) between an inner peripheral portion (thickness α) and an outer peripheral portion (thickness γ). In the embodiment of the present invention, the cam grooves 5a,
5b and 5c are concave cam grooves each having a bottom portion that does not penetrate the zoom cam ring 5. The cam groove 5a has the optical axis I
The cam grooves 5b and 5c are formed in a straight line in a direction intersecting the optical axis I. The cam grooves 5b and 5c are cam grooves having a depth .alpha.

The plate member 13 is a member for supporting a pin 14 described later. The plate member 13 includes a zoom cam ring 5.
A pin mounting portion 13b for mounting the pin 14 is formed on a surface on a side facing the outer peripheral surface. Plate member 13
The bent portion bent substantially vertically on the lens support frame 12 side is attached to the side surface of the flange portion of the sliding cylinder 6 where the male helicoid screw portion 6c is formed by screws 13a. The plate member 13 is a plate-shaped member that supports each of the two pins 14 that are arranged to face the zoom cam ring 5.

The pin 14 is a pin for moving the sliding cylinder 6 in the direction of the optical axis I by moving in contact along the cam groove 5a. The pin 14 protrudes from the plate member 13 and is movably fitted along the cam groove 5a.

The pin 15 is a pin for guiding the sliding cylinder 6 in the direction of the optical axis I by moving along the rectilinear groove 2h. The pin 15 is attached to a pin attaching portion 61a of the sliding cylinder 6, protrudes from the outer peripheral surface of the sliding cylinder 6, and is movably fitted along the straight groove 2h.

Next, the zooming operation of the lens barrel according to the first embodiment will be described. When the photographer rotates the zoom operation ring 4, the zoom cam ring 5 rotates around the optical axis I,
The pin 14 moves while contacting the side surface of the cam groove 5a.
The pin 14 is pushed by a side surface of the cam groove 5a in a direction substantially orthogonal to the cam groove 5a, and receives a driving force at a contact portion with the side surface of the cam groove 5a. This driving force is transmitted to the sliding cylinder 6 via the plate member 13, and the pin 15 moves along the straight groove 2h. As a result, the sliding cylinder 6 moves in the optical axis I direction while being in contact with the inner peripheral surface of the inner cylinder portion 2c, and the lens support frame 12 is integrated with the sliding cylinder 6 in the optical axis I direction. Moving. When the zoom cam ring 5 rotates, the support cylinders 7 and 8 to which the pins 10 and 11 are respectively attached move in the optical axis I direction while being in contact with the inner peripheral surface of the slide cylinder 6. By the above operation, the first lens group G1,
The zooming operation is performed by moving the second lens group G2, the third lens group G3, and the fourth lens group G4 in the direction of the optical axis I.

In the first embodiment of the present invention, the cam that moves the sliding cylinder 6 in the optical axis direction has a cam groove 5a formed on the outer periphery of the zoom cam ring 5, and is fitted into the cam groove 5a.
A drive cam comprising a pin 14 receiving a driving force from the cam groove 5a, a rectilinear groove 2h formed in the inner cylindrical portion 2c, and a pin 15 fitted in the rectilinear groove 2h and guided by the rectilinear groove 2h. The guide cam is divided into two parts. In the first embodiment of the present invention, the zoom cam ring 5
Concave cam grooves 5a, 5b, 5 having a bottom that does not penetrate through
“c” is formed on the outer peripheral portion and the inner peripheral portion of the zoom cam ring 5, but is not formed on the intermediate portion.

For this purpose, as shown in FIGS. 1 and 2,
The zoom cam ring 5 which was difficult with the conventional zoom cam ring
Cam groove 5a and cam grooves 5b, 5c in the radial direction of
Overlapping or close arrangement is possible. Zoom cam ring 5
Since the cam groove is not formed in the intermediate portion of, the strength of the zoom cam ring 5 can be sufficiently ensured even in such an arrangement. In addition, each of the cam grooves 5a, 5b, 5
Since there is no need to consider overlapping and proximity of c, the cam grooves 5a, 5b, 5c can be freely laid out on the inner and outer peripheral portions of the zoom cam ring 5. For example, since the cam groove 5a can be moved toward the mount portion 2a (right direction in the figure), the length Q of the zoom cam ring 5 in the optical axis I direction can be reduced.
Can be shorter than the length P of the conventional zoom cam ring 5 in the optical axis I direction. As a result, the zoom lens barrel 1
And the overall length of the zoom lens barrel 1 is shortened, so that the zoom lens barrel 1 is compact and lightweight.

In the first embodiment of the present invention, the cam grooves 5a,
By forming the 5b and 5c on the same zoom cam ring 5 instead of forming them on different members, the cam grooves 5a and 5c are formed.
The degrees of freedom of the layouts b and 5c are ensured. As a result, the positional accuracy between the cam grooves 5a, 5b, and 5c can be maintained at a high processing and assembling level, and the zoom lens barrel 1 having excellent optical performance without focal shift and deterioration can be manufactured. it can.

The cam groove 5 according to the first embodiment of the present invention
Since a, 5b, and 5c are cam grooves that do not penetrate the zoom cam ring 5, the roundness of the zoom cam ring 5 is equal to the cam groove 5.
This can be sufficiently ensured at the time of machining to form a, 5b, and 5c on the zoom cam ring 5. As a result, the zoom cam ring 5 can smoothly engage with the inner cylinder portion 2c and perform rotational sliding. Further, when a zoom lens barrel in which the distance between the lens groups constituting the photographing optical system is narrow is designed, the distance between the pins provided on the sliding cylinder that supports each lens group is reduced, and the zoom lens is formed on the zoom cam ring. The layout of the cam groove is limited. However, in the first embodiment of the present invention, the cam grooves 5a, 5b, 5c in the radial direction of the zoom cam ring 5 are not considered and the cam grooves 5a are formed in the inner peripheral portion and the outer peripheral portion of the zoom cam ring 5. , 5b, 5c can be laid out freely. The cam groove 5 is formed in the inner periphery of the zoom cam ring 5 made of plastic instead of metal.
When forming b and 5c, the cam groove can be easily formed by plastic molding, and the rigidity of the part itself during molding can be increased.

(Other Embodiments) The present invention is not limited to the above-described embodiments. According to the technical concept of the present invention, various modifications or changes are possible, and these are also within the equivalent scope of the present invention. It is. For example, in the first embodiment described above,
Concave cam grooves 5a, 5b, 5c each having a bottom are formed on the inner and outer peripheral portions of the zoom cam ring 5. The pins 10, 11 protrude from the inner peripheral portion and the pins 14 protrude from the outer peripheral portion. Is also good. Then, the cam groove 5 into which the pins 10 and 11 are fitted.
b and 5c are formed in the sliding cylinders 7 and 8, and the cam groove 5a in which the pin 14 is fitted is formed in the plate member 13, and these pins 10 and 1 are formed.
The sliding members 1 and 14 may be sandwiched between the sliding cylinders 7 and 8 and the plate member 13. Pins and cam grooves are arbitrarily formed on the inner and outer peripheral portions of the zoom cam ring 5, and the cam members into which the pins fit or the pins which fit into the cam grooves are fitted to the plate member 13 and the sliding cylinders 7 and 8. May be provided. The zoom cam ring 5 may be provided with both a cam groove penetrating the zoom cam ring 5 and a concave cam groove having a bottom. The present invention is not limited to the cam groove and the pin. For example, the cam groove and the pin may include a convex piece (cam) provided around the zoom cam ring 5 and a follower (cam follower) moving in contact with the convex piece. May be used.

In the embodiment of the present invention, the cam grooves 5a, 5
b and 5c are the outer and inner peripheral portions of the zoom cam ring 5, respectively.
It is formed at two locations that are 0 degrees symmetric,
0, 11, 14, and 15 are the cam grooves 5a, 5b,
5c are fitted one by one, but the number of cam grooves and pins is not limited. Further, the cam grooves 5a, 5b, and 5c are not limited to those relating to the zooming operation as in the embodiment of the present invention, and have the same effect even if they relate to the focusing operation, the focusing operation and the zooming operation, or other operations. Can play. The members for moving the sliding cylinder 6 are divided into a cam groove 5a and a pin 14 fitted in the cam groove 5a, and a rectilinear groove 2h and a pin 15 fitted in the cam groove 5a. May be divided into two as described above.

[0036]

As described above in detail, according to the first aspect of the present invention, at the position where the outer peripheral cam and the inner peripheral cam are arranged so as to overlap or approach at least in the radial direction of the cam cylinder. An intermediate separating portion is provided so as not to penetrate each other. According to the second aspect of the present invention, the cam cylinder has an outer diameter side layer, an intermediate layer, and an inner diameter side layer in order from the outer diameter side in the radial direction, and the outer diameter side layer and the inner diameter side layer have A plurality of cams are provided. Therefore, it is possible to increase the degree of freedom in layout when the cam is provided on the cam barrel while maintaining the structural strength of the cam barrel, and to shorten the length of the cam barrel in the optical axis direction, thereby achieving a lens barrel. Can be made compact.

According to the third aspect of the present invention, the plurality of cams formed on the cam barrel are grooved cams, convex cams, or a combination thereof. Can maintain the structural strength of
The cam can be formed so as to overlap or be adjacent in the radial direction of the cam cylinder.

[Brief description of the drawings]

FIG. 1 is a sectional view of a lens barrel according to an embodiment of the present invention.

FIG. 2 is a development view showing a state in which a zoom cam ring of the lens barrel according to the embodiment of the present invention is developed in a range of 360 degrees.

FIG. 3 is a sectional view showing an example of a conventional lens barrel.

FIG. 4 is a development view showing a state where a zoom cam ring of a conventional lens barrel is developed in a range of 360 degrees.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Zoom lens barrel 2 Fixed cylinder 2b Outer cylinder part 2c Inner cylinder part 2d, 2e, 2f, 2h Straight advance groove 3 Focus operation ring 4 Zoom operation ring 5 Zoom cam ring 5a, 5b, 5c Cam groove 6, 7, 8 Sliding Tube 6c Male helicoid screw part 9, 10, 11, 14, 15 pin 12 Lens support frame 12c Female helicoid screw part 13 Plate member G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth Lens group I Optical axis P, Q Length of zoom cam ring in optical axis direction α Thickness of inner circumference β Thickness of middle part γ Thickness of outer circumference

Claims (3)

[Claims] 1. A lens barrel having a cam barrel provided with a plurality of cams for moving at least a part of a photographing optical system in an optical axis direction, wherein the cam barrel has an outer peripheral portion provided on an outer periphery. A cam, an inner peripheral cam provided on an inner periphery, and a position where the outer peripheral cam and the inner peripheral cam are arranged so as to overlap or approach at least in the radial direction of the cam cylinder, and do not penetrate each other. A lens barrel comprising: an intermediate separating section provided for the following. 2. A lens barrel comprising a cam barrel having a plurality of cams formed therein for moving at least a part of a photographing optical system in an optical axis direction, wherein the cam barrel has an outer diameter side in a radial direction. A lens barrel having an outer diameter side layer, an intermediate layer, and an inner diameter side layer in this order, and wherein the plurality of cams are provided on the outer diameter side layer and the inner diameter side layer. 3. The lens barrel according to claim 1, wherein the plurality of cams formed in the cam barrel are groove cams, convex cams, or a combination thereof. Tube.