JPH08227086A - Lens barrel - Google Patents

Abstract

PURPOSE: To obtain a highly accurate lens barrel in which cam grooves adjacent to each other ate overlapped by providing plural cams having a shared area and an exclusive area, a cam pin, and a cam pin moving means. CONSTITUTION: In the case the cam pin moves in a collapsing direction C, the cam pin is pressed in a directions, so that the cam pin can move in a collapsing direction C as it is, and moves to a position P12 and a position P13. On the other hand, when the cam pin moves in a zooming direction Z, for example, a solenoid is energized to integrate a front group lens with a rear group lens at a position P11. A cam cylinder is driven in the condition, the cam pin moves in the moving direction H of a helicoid which is decided by a male helicoid and a female helicoid. The energizing of the solenoid is released after the cam pin reaches the position P14, then the cam pin moves in the zooming direction Z being the exclusive area which is branched from the shared area along the cam groove through the position P15. Consequently, the solenoid is energized only on an introducing area to the area R1 in the case the cam pin moves in the zooming direction Z.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel used for a camera or the like.

[0002]

2. Description of the Related Art The most commonly used zoom lens at the present time is a zoom lens having a two-group structure including a front lens group and a rear lens group. Since this zoom lens has a small movement amount during focusing, The moving mechanism of can also be downsized.

A schematic diagram of the movement of this zoom lens is shown in FIG. In the figure, FC is a front lens group, RC is a rear lens group, T is a long focal length, W is a short focal length, and C is a state when each lens is retracted. Normally, the front lens group FC is driven by a helicoid and the rear lens group RC is driven by a cam, but the front lens group FC can also be driven by a cam. When the respective lens groups are retracted into the camera body (not shown), the rear group lens RC is located closer to the film surface F, and therefore, the rear group lens RC is arranged before the front group lens FC is retracted. Is retracted first, and the rear lens group RC is kept in the retracted state until the front lens group FC is retracted. This rear lens group RC
Assuming that the collapsing region of D is D, the amount of D becomes a relatively large value.

The front lens group FC and the rear lens group RC
In order to stably drive the first lens group FC, the helicoid of the front lens group FC is formed as a multiple thread, and the cam groove of the cam that drives the rear lens group RC is formed by, for example, three cam grooves.

[0005]

However, the conventional lens barrel as described above has the following problems. That is, in order to operate the cam smoothly, the inclination angle of the cam groove is limited to about 40 ° at the maximum. Therefore, when a lens having a large movement amount is used, the rotation angle of the cam barrel forming the cam groove is also increased. growing. Normally, a plurality of cam grooves are formed in the collapsed region D because a plurality of cam grooves are formed. However, in order to form adjacent cam grooves independently, the number of cam grooves is an ideal number of three.
It is not possible to use two cams, for example, two cam cylinders must be used to obtain a large movement amount with a small rotation angle. However, increasing the outer diameter of the lens barrel increases the weight and is not preferable in all aspects as a product including portability. Further, when the number of cam grooves is two, the rear lens group RC is likely to tilt and the optical axis accuracy is lowered.

In view of the above problems, the present invention proposes a lens barrel in which adjacent cam grooves are overlapped, that is, overlapped.

FIG. 2 is a collapsed area D of the rear group lens RC adjacent to each other.
3 is a development view of a lens barrel in which the cam groove RCC in FIG. The cam groove RCC is orthogonal to the lens optical axis, and a part of the cam groove RCC overlaps. In the figure, the cam groove RCC is shifted to clarify the overlap region OV.
Although it is drawn on the main line, the lines actually overlap. FC
H indicates the locus of the front lens group FC due to the helicoid, and R
CZ indicates the locus of the rear lens group RC due to the cam.

When the cam groove RCC is overlapped, whether the cam pin sliding in the cam groove RCC of FIG. 2 advances in the RCZ direction or the RCC direction at the point P after passing the overlap area OV. Since it is not fixed, it is necessary to introduce the cam pin in a desired direction by some means. Such a configuration in which the cam pin is introduced in a desired direction is also one of the inventions of the present application.

[0009]

In the lens barrel for moving at least one of a predetermined lens group and performing at least one of zooming and focusing in the present invention, a lens frame for holding the lens group and the mirror A lens barrel arranged on the outer periphery of a frame, and a plurality of cams formed in the same shape on either the lens barrel or the lens barrel, the common region using at least two of the plurality of cams in common. A plurality of cams having a dedicated area branched from the common area, and a plurality of cam pins of the same shape that stand upright on either the lens frame or the lens barrel and engage with the plurality of cams, By providing cam pin moving means for moving the cam pin from the common area to the dedicated area, and by moving at least the first lens group and the second lens group, zooming or In a lens barrel that performs at least one of focusing, a first lens barrel holding the first lens group, a first lens barrel arranged on an outer periphery of the first lens frame, the first lens barrel, or A plurality of cams formed in the same shape on one of the first lens barrels; a plurality of cam pins of the same shape set upright on the other of the first lens frame or the first lens barrel; A second lens frame for holding the second lens group; a second lens barrel arranged on the outer periphery of the second lens frame and engaged with the second lens frame by helicoid screwing or cam engagement; A common area that is fixed to any of the second lens frames and that has a connecting means that connects the first lens frame and the second lens frame, and the cam is orthogonal to the optical axis and is used in common with an adjacent area. A dedicated area branched from the common area and the cam pin in a predetermined area of the common area. It is formed from an introduction area which is driven by the second lens frame connected to the first lens frame by the connecting means with the arrangement as a base point and is introduced into the dedicated area or re-introduced into the common area. , Zooming is performed by moving at least the first lens group and the second lens group, and when not in use, the first lens group and the second lens group are most retracted in the direction of the focus surface. In a lens barrel for retracting, a first lens barrel holding the first lens group, a first lens barrel arranged on the outer periphery of the first lens frame, the first lens barrel or the first lens barrel. A plurality of cam grooves formed in the same shape on one of the lens barrels; a plurality of cam pins of the same shape erected on the other of the first lens frame or the first lens barrel; A second lens frame for holding the lens group, and the second lens frame A second lens barrel that is disposed on the outer periphery and is helicoidally screwed or cam-engaged with the second lens frame, and is fixed to either the first lens frame or the second lens frame, and the first lens frame and the second lens frame are fixed. (2) A connecting means for connecting the lens frame, and a collapsible region used at the time of collapsing, which has a common portion for the cam groove which is orthogonal to the optical axis and is used in common with an adjacent cam groove, and a common portion of the collapsible area. A zooming area that is further branched and used for zooming, and the cam pin is driven by the second lens frame connected to the first lens frame by the connecting means with a predetermined position of the retractable area as a base point, and the zooming area is provided. Of the retractable region that can be introduced into the zooming region and an introducing region that moves to the vicinity of the branch portion of the zooming region, and the cam pin is urged toward the side wall side of the retractable region facing the side wall where the branch portion is formed. Equipped with a biasing member Zooming is performed by moving at least the first lens group and the second lens group, and when not in use, the first lens group and the second lens group are most repeatedly moved in the direction of the focus surface. In a lens barrel for retracting and retracting, a first lens barrel holding the first lens group, a first lens barrel arranged on the outer periphery of the first lens frame, the first lens barrel or the first lens barrel. A plurality of cam grooves formed in the same shape on one of the first lens barrels; a plurality of cam pins of the same shape set upright on the other of the first lens frame or the first lens barrel; Second lens frame that holds the second lens frame, a second lens barrel that is arranged on the outer periphery of the second lens frame and is helicoidally screwed or cam-engaged with the second lens frame, and the first lens frame or the first lens frame. It is fixed to either one of the two lens frames, and is connected to connect the first lens frame and the second lens frame. Means, the cam groove is provided with a common portion which is orthogonal to the optical axis and is used in common with an adjacent cam groove, and a collapsible area used for collapsing and a zooming portion branched from the common portion of the collapsible area. And a zooming region used for the above, and the cam pin driven by the second lens frame connected to the first lens frame by the connecting means with the predetermined position of the cam region as a base point, and the re-injection that can be introduced into the collapse region again. And a biasing member that biases the cam pin toward the side wall of the zooming region facing the side wall where the branch portion is formed. , Or a lens barrel that moves a predetermined lens group to perform at least one of zooming and focusing, and a lens frame that holds the lens group and an outer periphery of the lens frame. And a plurality of cams formed on either one of the lens barrel or the lens barrel and having the same center track but different groove widths and groove depths, and either the lens frame or the lens barrel. A plurality of cam pins provided upright on the other side and having different thicknesses and lengths corresponding to the cams are provided, and the plurality of cams have one end orthogonal to the optical axis and overlapped at the same position. It is achieved by having.

[0010]

Embodiments of the present invention will be described in detail with reference to FIGS.

FIG. 3 shows an embodiment of the zoom lens barrel for carrying out the present invention. This drawing is a vertical sectional view of the zoom lens barrel capable of performing zooming and focusing by the same mechanism. The state when the lens is retracted is drawn above the optical axis, and the state when the zoom lens is extended is drawn below the optical axis.

Reference numeral 1 denotes a fixed barrel fixed integrally with the camera body, and a female helicoid 1a is screwed on the inner circumference.
Reference numeral 2 denotes a cam barrel referred to as a first barrel and a second barrel in the claims. A male helicoid 2a and a large gear 2b, which are screwed with the female helicoid 1a, are integrally formed on the outer periphery, and the inner gear is formed on the inner periphery. Female helicoid 2c and cam groove 2d which is an inner cam
And a rib 2e is provided inward of the rear end portion.
The tip circle of the large gear 2b is formed smaller than the root diameter of the male helicoid 2a. Reference numeral 3 denotes a front lens group holding frame, which is called a second lens frame in the claims, and a front lens group frame 4 holding a front lens group FC having a positive combined focal length is attached by screws from the front. For manufacturing dimensional error of lens system parts, change the mounting position of this screw part. Front group holding frame 3
A male helicoid 3a screwed with the female helicoid 2c is provided on the outer periphery of the. Reference numeral 5 denotes a rear group holding frame, which is referred to as a first lens frame in the claims, which holds a rear group lens RC having a negative combined focal length on the inner circumference and a cam pin 7 which engages with the cam groove 2d on the outer circumference. The guide shaft 8 is provided upright and protrudes forward. The guide shaft 8 is made of a magnetic material and passes through the front group holding frame 3 and the solenoid 9 which is a connecting means fixed to the front group holding frame 3.

Reference numeral 11 denotes a straight guide, which is symmetrically at least 2
A guide groove 1 formed on the fixed barrel 1 across the female helicoid 1a in parallel with the optical axis by the protruding portions 11a protruding at various locations.
On the other hand, it is slidably engaged with b, and on the other hand, the front end is slidably engaged with the front group holding frame 3 by an arm portion 11b (not shown) up to the tip. Reference numeral 12 denotes a guide fixing plate that connects the cam barrel 2 and the straight guide 11 to each other,
13 connects the straight guide 11 and the guide fixing plate 12,
A fixed guide shaft for holding the cam barrel 2, 14 is a straight guide 1
1 is a set screw for holding 1 on the fixed guide shaft 13.

Reference numeral 21 denotes the external appearance of the camera, which is a decorative ring 22.
Is attached to the cam barrel 2 and the front barrel 23 is attached to the front group holding frame 3.

Next, the basic operation of the zoom lens barrel will be described.

The zoom lens barrel of this embodiment has a front lens group FC and a rear lens group R by the same mechanism, as will be described later.
Drive C to perform zooming and focusing. When a driving motor (not shown) is driven to rotate during zooming or focusing, the driving force is transmitted through a hole (not shown) cut in the fixed barrel 1 to rotate the cam barrel 2 to move the fixed barrel. The cam barrel 2 screwed with the helicoid 1 is moved in the optical axis direction. At this time, the cam barrel 2 moves forward or backward in the optical axis direction depending on the direction of rotation of the drive motor. The rectilinear guide 11 is integrally attached to the rib 2e of the cam barrel 2 by the guide fixing plate 11, the guide fixing shaft 13, and the set screw 14. The rectilinear guide 11 includes the projecting portion 11a and the guide groove of the fixed barrel 1. Rotation is blocked by engagement with 1b, and only movement in the optical axis direction is performed.
Similarly, the front group holding frame 3 penetrating the arm portion 11b of the straight guide 11 is prevented from rotating. Further, since the guide shaft 8 protruding from the rear group holding frame 5 penetrates through the front group holding frame 3, the rear group holding frame 5 is also movable together with the front group holding frame 3 only in the optical axis direction. . Therefore, when the cam barrel 2 rotationally moves, the front group holding frame 3 helicoidally coupled with the cam barrel 2 and the rear group holding frame 5 cam-coupled with the cam barrel 2.
Only moves forward or backward in the optical axis direction.

The cam groove 2d of the cam barrel 2 is formed by alternately repeating an inclination angle smaller than the lead angle of the female helicoid 2c and a large inclination angle, and the front group holding frame 3 is linearly moved by the helicoid. On the other hand, the rear group holding frame 5 makes a mountain-shaped discontinuous movement. Although details will be described in a later-described zoom diagram, since the zooming region and the focusing region are continuously provided, the focusing drive and the zooming drive can be performed by the same mechanism.

The above-mentioned zoom lens barrel is a so-called step zoom type zoom lens barrel in which the distance between the longest focal length and the shortest focal length is divided into a predetermined number of steps or focal lengths of steps. . This step zoom will be described with reference to the zoom diagram of FIG. In the figure, the horizontal axis represents the change in the focal length, W represents the shortest focal length, M ₁ and M ₂ sequentially increase the focal length, and T the longest focal length. In this way, the focal length can be switched to 4 steps in zooming. The vertical axis represents the amount of movement of the front lens group FC and the rear lens group RC of the zoom lens in the optical axis direction. Since the front lens group FC is screwed into the rotating cam barrel 2 by helicoid, the front lens group FC moves linearly as the cam barrel 2 rotates. On the other hand, the rear lens group RC is driven by a cam carved in the cam barrel 2, and the photographing distance U repeatedly moves in a mountain shape between a focus position of ∞, that is, infinity and a focus position of N, that is, a close distance. So that the cam is formed. For example, when the focal length is set to the position of W, if the focusing is performed, the front lens group FC and the rear lens group RC move between W and the W according to the shooting distance, and one step zooming to the telephoto side is performed. The front lens group FC and the rear lens group RC move to the position of M ₁ via and.
Similarly, if you perform two-step zooming on the telephoto side,
, M ₁ , and move to the position of M ₂ . As described above, since the focusing and zooming are repeated by moving the front lens group FC and the rear lens group RC, the focusing mechanism and the zooming mechanism can be configured by the same mechanism, and inevitably. Since the number of parts is reduced and the configuration is simple, a compact zoom lens barrel can be realized.

Contrary to the above, the cam pin 7 is attached to the cam barrel 2.
May be provided upright and a cam may be formed on the rear group holding frame 5, or the cam barrel 2 and the front group holding frame 3 may be connected by cam instead of by a helicoid.

The front lens group FC and the rear lens group RC may be driven by lens barrels having different helicoids and cam barrels.

Although the above embodiments have been described with respect to the zoom lens having the two-group structure, the same applies to the zoom lens having the three-group structure.

Further, the zoom lens barrel of the present invention is not limited to the above-mentioned constitution, and the front lens group FC and the rear lens group RC are driven by different driving sources, and both lens groups are driven during zooming. The present invention can also be applied to a zooming lens barrel that moves only the front lens group FC or the rear lens group RC during focusing.

Next, an embodiment in which adjacent cams are overlapped will be described, which is the gist of the present invention.

In this embodiment, even if the adjacent cam grooves have the same width and depth and the same shape, the direction in which the cam pin should travel can be reliably determined at the end point P of the overlap area OV shown in FIG. It is configured as follows.

FIG. 5 is an enlarged view of the cam pin moving in the cam groove. In the figure, the cam pin is used in common with the adjacent cam grooves, and moves in a common area including at least P0 to P11 as in the overlap area OV in FIG.
When moving from 0 to P11, it is necessary to decide whether to proceed in the retracting direction C or the zooming direction Z.
As can be easily seen from FIGS. 1 and 2, the front lens group F
When C and the rear lens group RC are both fully retracted and the cam pin starts moving in the retracted area D, it is necessary to move the cam pin along the cam RCC, the overlap area OV ends, and the point P in FIG. When it comes to, it is necessary to move it along the cam RCZ.

In FIG. 5, when the cam pin is moved in the collapsing direction C, since the cam pin is biased in the S direction by a spiral spring or the like, it can be naturally moved in the collapsing direction C if it is driven as it is. Yes, you can move to P12 and P13. On the other hand, when the cam pin is moved in the zooming direction Z, the solenoid 9 shown in FIG. 3 is energized at the point P11 to attract the guide shaft 8 to attract the solenoid 9 and the guide shaft 8, that is, the front lens group FC. And the rear lens group RC are integrated. When the cam barrel 2 of FIG. 3 is driven in this state, the cam pin moves in the helicoid movement direction H determined by the female helicoid 2b and the male helicoid 3a. After the cam pin reaches the position P14, the solenoid 9 is de-energized, and thereafter, the cam pin moves along the cam groove in the zooming direction Z, which is a dedicated region branched from the common region, through P15. Therefore,
When the cam pin is moved in the zooming direction Z, the solenoid 9 is energized only in the introduction region of R1.

FIG. 6 is a view of another embodiment in which the biasing direction S of the cam pin is opposite to that of FIG.
3 and move in the zooming direction Z naturally. On the other hand, P21
When the solenoid 9 is energized in the introduction region of R2 with, the cam pin moves in the moving direction H of the helicoid, and P24, P2
It moves again in the retracting direction C via 5.

FIG. 7 is a block diagram of a camera that performs the above-described operation. The control unit 31 drives the zoom motor 32 by turning on the zoom SW to extend the lens barrel from the retracted area, and the pulse detector 33 detects the number of pulses generated as the zoom motor 32 rotates during the extension. Move the cam pin from the position P11 to the position P14, or P21.
In the introduction area to move from the position of to the position of P24,
The actuator 34 including a solenoid is driven.

Although the above description has been given of an example in which the cam pin is moved from the retracted area to the zooming area, the present invention is not limited to this and can be applied to the case of moving from the zooming area to the focusing area.

8 and 9 show another embodiment in which the front lens group FC and the rear lens group RC are connected to each other. FIG. 8 is a perspective view of the lens barrel and FIG. 9 is an enlarged view showing a locked state.

In FIG. 8, reference numeral 43 denotes an inner cylinder, which holds a front lens group FC (not shown), and is linearly moved by a helicoid drive by a cam cylinder (not shown). A lens holding frame 44 holds the rear lens group RC and is driven by a cam by a cam barrel to move straight. 5
Reference numeral 1 is a solenoid, which is integrally attached to the lens holding frame 44 and, when energized, causes the lock claw 52 to move to the solenoid 51.
More prominent. As described above, the stop position P11 or P21
In order to connect the front lens group FC and the rear lens group RC with each other, when the solenoid 51 is energized at a slightly earlier P0 as shown in FIG. 9, the lock claw 52 projects and the inner cylinder 43 moves due to the movement of the inner cylinder 43. The lens holding frame 4 is engaged with the protrusion 43a provided on the inner circumference to be integrated with the movement of the inner cylinder 43.
4 moves. The spring 45 is biased in the direction in which the lock claw 52 and the protrusion 43a come into contact with each other.

FIG. 10 is a diagram of another embodiment of the cam groove in which the cam grooves overlap and the direction in which the cam pin advances is clear without using the solenoid.

FIG. 10A is a plan view of the cam groove.
10B to 10D are views of the cam groove and the cam pin.
The respective cam grooves RC1, RC2, and RC3 have the same center track, but one end orthogonal to the optical axis is formed at the same position in an overlapping manner. As shown in FIG. 10C, the cam groove RC1 has the largest groove width and the smallest groove depth. As shown in FIG. 10D, the cam groove RC3 has the narrowest groove width and the deepest groove depth. As shown in FIG. 10B, the cam groove RC2 is in the middle between the cam groove RC1 and the cam groove RC3 in terms of groove width and groove depth.

By forming the cam groove in this way, the cam pin P1 moves in the cam groove RC1 and the cam pin P1.
2 moves in the cam groove RC2, and the cam pin P3 moves in the cam groove RC2.
3 can be moved, and even if each cam groove overlaps, the orbit does not go wrong.

[0035]

According to the first aspect of the lens barrel of the present invention,
According to any one of items 1 to 8, since a large number of cam grooves are formed by overlapping, the optical axis accuracy can be maintained without tilting the lens even when a lens having a large movement amount is used. Moreover, since it is not necessary to make the cam barrel double or triple, the lens barrel is not increased.

Further, according to the first or second aspect of the lens barrel of the present invention, even if the adjacent cam grooves are formed in the same shape, the cam pin is surely moved to the dedicated area branched from the common area. As a result, it becomes easy to control the accuracy of the cam and the cam pin.

Further, according to any one of claims 3 to 7 in the lens barrel of the present invention, even if the adjacent cam grooves are formed in the same shape, the cam pin is surely provided in the zooming area branched from the collapsing area. Can be moved to the
The accuracy control of cams and cam pins becomes easy.

According to the eighth aspect of the lens barrel of the present invention, the direction in which the cam pin advances can be clearly defined without using a solenoid.

[Brief description of drawings]

FIG. 1 is a schematic diagram of movement of a zoom lens.

FIG. 2 is a development view of a lens barrel in which cam grooves of adjacent rear group lenses are overlapped with each other.

FIG. 3 is an example of a zoom lens barrel for carrying out the present invention.

FIG. 4 is a zoom diagram of a zoom lens barrel that is an example.

FIG. 5 is an enlarged view of overlapping cam grooves.

FIG. 6 is an enlarged view of another embodiment of overlapping cam grooves.

FIG. 7 is a block diagram for performing the operation of the present invention.

FIG. 8 is a perspective view of another embodiment in which a front lens group and a rear lens group are integrated.

FIG. 9 is an enlarged view of another embodiment in which a front lens group and a rear lens group are integrated.

FIG. 10 is a view of cam grooves that are changed in shape and overlapped.

[Explanation of symbols]

 FC Front group lens RC Rear group lens D Collapse area OV Overlap area R1, R2 Introduction area 1 Fixed barrel 2 Cam barrel 2d Cam groove 3 Front group holding frame 5 Rear group holding frame 7 Cam pin 8 Guide shaft 9,51 Solenoid 11 Straight advance guide

Claims (8)

[Claims] 1. A lens barrel for moving a predetermined lens group to perform at least one of zooming and focusing, a lens frame holding the lens group, and a lens barrel arranged on the outer periphery of the lens frame. A plurality of cams formed in the same shape on one of the lens frame or the lens barrel and having a common area in which at least two of the plurality of cams are commonly used, and a dedicated area branched from the common area. A plurality of cams having the same shape, a plurality of cam pins of the same shape that stand upright on the other of the lens frame or the lens barrel and engage with the plurality of cams, and move the cam pins from the common area to the dedicated area. A lens barrel having cam pin moving means for causing the lens barrel to move. 2. A lens barrel for performing at least one of zooming and focusing by moving at least a first lens group and a second lens group, the first lens frame holding the first lens group. A first lens barrel arranged on the outer periphery of the first lens frame; a plurality of cams formed in the same shape on either the first lens frame or the first lens barrel; A plurality of cam pins of the same shape that are erected on the other side of the frame or the first lens barrel, a second lens frame that holds the second lens group, and a second lens frame that is arranged on the outer periphery of the second lens frame. A second lens barrel that is helicoidally screwed or cam-engaged with the second lens frame, and is fixed to either the first lens frame or the second lens frame, and connects the first lens frame and the second lens frame. A connecting means is provided, and the cams are adjacent to each other in a direction orthogonal to the optical axis. And a common area shared by the common area, a dedicated area branched from the common area, and the cam pin driven by the second lens frame connected to the first lens frame by the connecting means with a predetermined position of the common area as a base point. However, the lens barrel is formed from an introduction region for introducing into the dedicated region or re-introducing into the common region. 3. Zooming is performed by moving at least a first lens group and a second lens group, and the first lens group and the second lens group are brought into a direction of a focus surface when not in use. In a lens barrel that is most retracted into a lens barrel, the first lens barrel holding the first lens group, the first lens barrel arranged on the outer periphery of the first lens frame, and the first lens frame. Alternatively, a plurality of cam grooves formed in the same shape on either one of the first lens barrel, and a plurality of cam pins of the same shape erected on the other of the first lens frame or the first lens barrel, A second lens barrel for holding the second lens group; a second lens barrel arranged on the outer periphery of the second lens frame and engaged with the second lens frame by helicoid screwing or cam engagement; Alternatively, the first lens frame and the second lens frame are fixed to any of the second lens frames. A connecting means for connecting the cam groove is provided, and the cam groove is orthogonal to the optical axis and has a common portion which is used in common with an adjacent cam groove and which is used for collapsing and is branched from the common portion of the collapsing area. A zooming area used for zooming and the cam pin can be introduced into the zooming area by being driven by the second lens frame connected to the first lens frame by the connecting means with a predetermined position of the retractable area as a base point. A retracting region and an introducing region for moving the zooming region to the vicinity of a branching portion, and a biasing member for biasing the cam pin toward the side wall of the collapsing region facing the side wall where the branching portion is formed. A lens barrel characterized by that. 4. Zooming is performed by moving at least a first lens group and a second lens group, and at the time of non-use, the first lens group and the second lens group are directed toward a focus plane. In a lens barrel that is most retracted into a lens barrel, the first lens barrel holding the first lens group, the first lens barrel arranged on the outer periphery of the first lens frame, and the first lens frame. Alternatively, a plurality of cam grooves formed in the same shape on either one of the first lens barrel, and a plurality of cam pins of the same shape erected on the other of the first lens frame or the first lens barrel, A second lens barrel for holding the second lens group; a second lens barrel arranged on the outer periphery of the second lens frame and engaged with the second lens frame by helicoid screwing or cam engagement; Alternatively, the first lens frame and the second lens frame are fixed to any of the second lens frames. A connecting means for connecting the cam groove is provided, and the cam groove is orthogonal to the optical axis and has a common portion which is used in common with an adjacent cam groove and which is used for collapsing and is branched from the common portion of the collapsing area. The zooming area used during zooming and the cam pin can be driven by the second lens frame connected to the first lens frame by the connecting means with a predetermined position of the collapsed area as a base point, and can be introduced into the collapsed area again. A biasing member that is formed from a retracting region and an introduction region that moves to the vicinity of a branch portion of the zooming region, and that biases the cam pin to the side wall side of the zooming region facing the side wall where the branch portion is formed. A lens barrel that is equipped. 5. The lens barrel according to claim 3, wherein the coupling of the coupling means is released after the cam pin is moved to the vicinity of the branch portion. 6. The lens barrel according to claim 2, wherein the first lens barrel and the second lens barrel are integrally formed. 7. The lens barrel according to claim 3, wherein the connecting means is a solenoid, and only the introduction area is energized. 8. A lens barrel that moves a predetermined lens group to perform at least one of zooming and focusing, and a lens frame that holds the lens group, and a lens barrel that is arranged on the outer periphery of the lens frame. A plurality of cams formed on either one of the lens frame or the lens barrel, having the same center track and different groove widths and groove depths, and standing upright on the other of the lens frame or the lens barrel. A plurality of cam pins having different thicknesses and lengths corresponding to the cams are provided, and each of the plurality of cams has an overlapping portion formed at one end orthogonal to the optical axis and overlapping at the same position. A lens barrel characterized by.