JPH11258480A - Lens barrel - Google Patents

Abstract

(57) [Problem] To use a U-turn flexible, it is difficult to reduce the size of a lens barrel due to its arrangement space. A flexible printed wiring board (11) for electrically connecting a fixed barrel member (2) and a movable barrel member (8) movable with respect to the fixed barrel member is provided. In a lens barrel provided with a U-turn portion 11d whose bending apex position moves in accordance with the movement, in the U-turn portion (in particular, when the movable barrel member in the U-turn portion is farthest from the fixed barrel member, the optical axis A narrow portion 11b is formed at a position that is the end in the direction.

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 an electric circuit mounted inside, such as an interchangeable lens for a single-lens reflex camera, and more particularly, to an electrical connection between a movable barrel member and a fixed barrel member. The present invention relates to a lens barrel using a flexible printed wiring board connected to a lens barrel.

[0002]

2. Description of the Related Art In recent years, auto-focusing has become the mainstream for single-lens reflex cameras, and even in an interchangeable lens mounted on the camera, a motor for driving a lens group for focusing, an electric circuit for controlling the motor, and an actual aperture of an automatic aperture Electric circuits for performing various controls, such as a motor for changing the power and an electric circuit for controlling the motor, and an electric circuit for exchanging and communicating information between the camera body and the interchangeable lens, are required. I have.

Further, in such a lens, a flexible printed board (hereinafter, referred to as a flexible board) is generally used to connect the above-described motor and the like to a mounting board due to a wiring space. .

[0004] When a motor or the like is attached to the movable lens group, a general method is to take a margin in advance from the motor toward the mounting substrate and absorb the movement of the movable lens group by bending or deforming the flexible. It has been used extensively. In particular, a method of arranging a flexure having a U-turn portion that is folded with a curvature in the optical axis direction and absorbing the movement of the movable lens group by moving the apex portion of the U-turn portion is often used.

FIGS. 6 to 8 show the structure of an interchangeable lens for a single-lens reflex camera. FIG. 6 shows the interchangeable lens cut along a plane parallel to the optical axis. FIGS. 7 and 8 show the flexible lens when the position of the movable lens group is closest to and farthest from the flexible fixing unit. The state of is shown.

In these figures, reference numeral 101 denotes a mount cylinder, and a bayonet claw 10 for attaching to a camera body (not shown) is provided at the rear end of the mount cylinder 101 in the optical axis direction.
1a is formed. Further, an external portion 101b is formed at a front portion of the mount cylinder 101 in the optical axis direction.

A guide cylinder 102 has its right end fixed to the mount cylinder 101 with screws or the like. Guide tube 10
An electric circuit board 103 is fixed between 2 and the mount cylinder 101.

Reference numeral 104 denotes a zoom operation cylinder. The pawl portion 104a of the zoom operation tube 104 is engaged with the bayonet portion 102a of the guide tube 102 in a bayonet manner. This allows
The zoom operation barrel 104 is supported so that it can rotate only around the optical axis. A rectilinear groove 104b extending along the optical axis direction is formed on the inner peripheral surface of the zoom operation barrel 104.

Reference numeral 105 denotes a straight cylinder. This straight moving cylinder 105
Are engaged with the rectilinear grooves 104b, and the rectilinear cylinder 1
A rectilinear key 106 is integrally fixed to the inner periphery of 05. The rectilinear key 106 is engaged with a rectilinear key guide groove provided on the outer diameter side of the guide cylinder 102 and extending parallel to the optical axis direction.
Reference numeral 06 is supported on the guide cylinder 102 so as to be movable only in the optical axis direction. In addition, a convex cam portion 105 b protruding in the inner circumferential direction is provided on the inner circumferential surface of the rectilinear barrel 105.

Reference numeral 107 denotes a first lens barrel for holding the first lens group on the inner peripheral side. The female helicoid provided on the inner peripheral surface of the first lens barrel 107 is connected to the male helicoid provided on the outer peripheral surface of the rectilinear barrel 105.

Reference numeral 108 denotes a second lens barrel for holding the second lens group on the inner peripheral side. The second lens barrel 108 is radially fitted to the inner peripheral surface of the guide cylinder 102 on the outer peripheral side. Also, the second lens barrel 1
A plurality of rollers 109 are fixed to the outer peripheral surface of the device 08 in the radial direction around the optical axis with screws or the like. Roller 10
9 is fitted in the first cam groove 102b provided in the guide cylinder 102 and the convex cam portion 105b provided in the rectilinear cylinder 105.

Reference numeral 110 denotes an electromagnetic diaphragm unit, which comprises a diaphragm 110a and a motor 110b.
One end of an electric wiring flexible 111 for feeding and controlling the motor 110b is bonded and soldered to the motor 110b.

Reference numeral 112 denotes a flexible holding plate for guiding and fixing the folded portion of the flexible 111 in the middle. The flexible holding plate 112 is fixed to a part of the guide cylinder 102 and adhesively holds a part of the flexible 111.
The other end of the flexible 111 is electrically connected to the electric circuit board 103.

The arrangement of the flexible member 111 will be described in detail. As shown in FIGS.
One end 111a of the first unit 111 is fixed to the motor unit 110b of the electromagnetic diaphragm unit 110 attached to the second lens barrel 108, and the electric terminals of the motor unit 110b and the wiring pattern in the flexible 111 are connected by soldering or the like. .
The flexible member 111 is attached along the wall of the second lens barrel 105 and extends from the second lens barrel 108 to the rear in the optical axis direction.
An attaching portion 111c of the flexible 111 is attached along the turn guide portion 108a.

The flex 111 thus attached to the second lens barrel 108 is U-turned forward in the optical axis direction at an appropriate curvature in the U-turn section 111d, the intermediate section 111e is extended forward in the optical axis direction, and the bent section 111g is extended. At the rear side in the optical axis direction, and is further attached to the surface 112b of the flexible holding plate 112 at the attaching portion 111h. After that, the drawer 111i of the flexible 111 is pulled out to the mount side, and its terminal end is connected to a connector or the like arranged on the electric circuit board 103.

The flexible holding plate 112 is attached to the mounting portion 1.
The plate bending member 12a is fixed to the guide cylinder 102 with screws or the like and extends forward in the optical axis direction, and has a sandwiching portion 112c that is bent rearward at the front end. The sandwiching portion 112c sandwiches and holds the bent portion 111g of the flexible 111, and presses the pressing portion 111f in the vicinity of the bent portion 111g, thereby suppressing the rebound of the flexible 111 due to the bending.

Next, the operation of the interchangeable lens configured as described above will be described. When the photographer rotates the zoom operation tube 104, a cam groove 104b provided on the inner periphery of the zoom operation tube 104 and a convex portion 105 provided on the rectilinear movement tube 105
a and the straight key 106 fixed to the straight barrel 105 and the straight key guide groove provided on the outer periphery of the guide barrel 102, the straight barrel 105 is moved in the optical axis direction (left side in the figure). Go to Along with this, the first lens barrel 107
And the first lens group also moves.

The movement of the rectilinear barrel 105 in the direction of the optical axis causes
The roller 109 located at the intersection of the convex cam portion 105b provided on the inner peripheral portion of the rectilinear cylinder 105 and the cam groove 102b provided on the guide cylinder 102 rotates around the optical axis with the movement of the cam intersection. While moving in the optical axis direction. Accordingly, the second lens barrel 108 and the second lens group / electromagnetic diaphragm unit 110 to which the rollers 109 are attached also move in the optical axis direction while rotating around the optical axis. As described above, the positions of the first lens group and the second lens group in the optical axis direction change, and the focal length of the lens changes.

When the zoom operation of the interchangeable lens is performed, the flexible lens 111 is deformed to absorb the extension amount of the second lens barrel 108. Specifically, as shown in FIGS. 7 and 8, the part from the one end 111 a of the flexible 111 to the attaching part 111 c moves together with the second lens barrel 108, and the part from the holding part 111 f and the bending part 111 g to the drawing part 111 i. Is fixed to the guide cylinder 102 by a flexible holding plate 112. And the U-turn part 111d
The portion from to the holding portion 111f absorbs the extension amount of the second lens barrel 108 while changing the vertex position of the U-turn portion.

[0020]

In recent years, there has been a demand for electronic and miniaturized interchangeable lenses used in single-lens reflex cameras as well as electronic and miniaturized cameras. For this reason, an electric element, a driving device, and the like are often held by the movable portion of the interchangeable lens. Therefore, the electric connection method using the U-turn flexible as described above is an effective technique.

However, in order to reduce the size using the U-turn flexible, it is necessary to make the space for arranging the U-turn flexible as small as possible.

As shown in FIG. 6, a flexible holding plate 112 conventionally formed by punching or bending metal is used.
Is used, the number of parts is increased, and problems such as an increase in cost and an increase in the complexity of the assembling process are caused. For this reason, the flexible holding plate 112 is formed by molding the resin into a guide cylinder 10.
It is conceivable to integrally mold it with 2.

However, when integrally molded with the guide cylinder 102, it is difficult to mold the sandwiching portion 112c.
For this reason, it is not possible to prevent the portion from the bent portion 111g of the flexible 111 to the U-turn portion 111d from moving in a direction in which the flexible 111 rebounds greatly, and the U-turn portion of the flexible 111 due to zooming is initially prevented. 9 and 10, there is a possibility that the guide tube 102 of the flexible cable 111 may be caught or jammed during zooming, as shown in FIGS.

[0024]

According to a first aspect of the present invention, a fixed barrel member and a movable barrel member movable with respect to the fixed barrel member are electrically connected. In a lens barrel having a flexible printed wiring board, the flexible printed wiring board is provided with a U-turn portion in which a bending apex position is moved according to the movement of the movable barrel member,
A narrow portion is formed in the U-turn portion (particularly, in the U-turn portion, a position where the movable barrel member is located at the end in the optical axis direction when the movable barrel member is farthest from the fixed barrel member).

Thus, the curvature of the narrow portion of the flexible printed wiring board can be made smaller than that of the other portions, and the spread of the entire U-turn portion can be suppressed. For this reason, it is possible to prevent interference between the flexible printed wiring board and the lens barrel member or the like with a simple configuration. In addition, since a portion for holding the flexible printed wiring board can be integrally formed with the fixed lens barrel member without the need for the flexible holding plate, the number of components is reduced, thereby simplifying assembly and reducing costs.

Further, according to the invention, the portion of the flexible printed wiring board adjacent to the U-turn portion is held by, for example, attaching to the wiring board holding portion formed on the movable barrel member so as to extend in the optical axis direction. In such a case, even if the flexible holding plate is abolished or the length of the wiring board holding portion is shortened, it is possible to prevent the U-turn portion from spreading beyond the wiring board holding portion. If the length of the wiring board holding portion is reduced, the entire length of the flexible printed wiring board can be reduced while securing a sufficiently long U-turn portion. As a result, the size of the lens barrel can be reduced.

A reinforcing pattern for suppressing bending may be formed in a portion other than the narrow portion in the U-turn portion.

Further, in the second invention of the present application, a flexible printed wiring board for electrically connecting a fixed lens barrel and a movable lens barrel movable with respect to the fixed lens barrel is provided. In a lens barrel in which the flexible printed wiring board is twisted in accordance with the movement, a narrow portion is formed in the flexible printed wiring board where the twist occurs.

Thus, the deformation of the flexible printed wiring board due to the torsion can be largely absorbed by the narrow portion, so that it is easy to predict the deformation of the entire flexible printed wiring board due to the torsion force. For this reason, it is possible to facilitate the method of holding the flexible printed wiring board.

Note that a reinforcing pattern for suppressing twisting may be formed in a portion other than the narrow portion.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 to 4 show an interchangeable lens for a single-lens reflex camera provided with a flexible printed wiring board (hereinafter referred to as "flexible") according to a first embodiment of the present invention. Is shown. FIG. 1 shows the interchangeable lens cut along a plane parallel to the optical axis, and FIG. 2 shows the shape of the flexible lens. 3 and 4
Indicates a flexible state when the position of the movable lens group is closest to the flexible fixed portion (wide) and farthest (tele).

In these figures, reference numeral 1 denotes a mount cylinder, and a bayonet claw 1a for attachment to a camera body (not shown) is formed at the rear end of the mount cylinder 1 in the optical axis direction. Further, an outer appearance portion 1b is formed at a front portion of the mount cylinder 1 in the optical axis direction.

Reference numeral 2 denotes a guide cylinder, the right end of which is fixed to the mount cylinder 1 with screws or the like. An electric circuit board 3 is fixed between the guide cylinder 2 and the mount cylinder 1. In addition,
The guide tube 2 and the mount tube 1 to which the electric circuit board 3 is fixed correspond to a fixed lens barrel member described in claims.

Reference numeral 4 denotes a zoom operation cylinder. The pawl portion 4a of the zoom operation tube 4 is in bayonet engagement with the bayonet portion 2a of the guide tube 2. Thereby, the zoom operation barrel 4 is supported so as to be rotatable only around the optical axis. A rectilinear groove 4b extending along the optical axis direction is formed on the inner peripheral surface of the zoom operation barrel 4.

Reference numeral 5 denotes a straight cylinder. The projecting portion 5a of the rectilinear cylinder 5 is engaged with the rectilinear groove 4b, and a linear key 6 is integrally fixed to the inner periphery of the rectilinear cylinder 5. And the straight key 6 is
The linear cylinder 5 is engaged with a linear key guide groove provided on the outer diameter side of the guide cylinder 2 and extending parallel to the optical axis direction.
The straight key 6 is supported so as to be movable only in the optical axis direction with respect to the guide cylinder 2. In addition, a convex cam portion 5b protruding in the inner circumferential direction is provided on the inner circumferential surface of the rectilinear barrel 5.

Reference numeral 7 denotes a lens holding the first lens group on the inner peripheral side.
It is a group lens barrel. The female helicoid provided on the inner peripheral surface of the first lens barrel 7 is connected to the male helicoid provided on the outer peripheral surface of the rectilinear barrel 5.

Numeral 8 denotes a lens holding the second lens group on the inner peripheral side.
It is a group lens barrel. The second lens barrel 8 is radially fitted to the inner peripheral surface of the guide cylinder 2 on the outer peripheral side. A plurality of rollers 9 are fixed to the outer peripheral surface of the second lens barrel 8 in a radial direction about the optical axis by screws or the like. The roller 9 has a first cam groove 2b provided in the guide cylinder 2 and a convex cam portion 5b provided in the straight-moving cylinder 5.
And is fitted with.

Numeral 10 denotes an electromagnetic diaphragm unit fixed to the second lens barrel 8, which is composed of a diaphragm 10a and a motor 10b. One end of a flexible cable 11 for electric wiring for supplying power to and controlling the motor unit 10b is bonded and soldered to the motor unit 10b. The second group barrel 8 to which the electromagnetic diaphragm unit 10 is fixed corresponds to a movable barrel member described in claims.

Reference numeral 2c denotes a first flexible guide portion (a second wiring board holding portion in the claims) for guiding and fixing the halfway folded portion of the flexible 11. The first flexible guide portion 2c is formed integrally with the guide tube 2 and extends in the optical axis direction, and adhesively holds a part of the flexible 11. Note that the other end of the flexible 11 is electrically connected to the electric circuit board 3.

Here, as shown in FIG. 2, the flexible 11 has a wide portion 11a and a narrow portion 11b formed in the middle of the wide portion 11a in the longitudinal direction. 11c is a conductor pattern part, and 11p is a reinforcement pattern part. The width of the narrow portion 11b is the minimum width required for the conductor pattern portion 11c.

When the same bending force is applied to the wide portion 11a and the narrow portion 11b, the bending amount of the narrow portion 11b becomes large.
The width difference is larger than the bending amount of “a”. Also, since the wide portion 11a has the reinforcing pattern portion 11p, the narrow portion 1
1b has a larger bending amount than the wide portion 11a. For this reason, the bent shape of the U-turn portion can be controlled by providing the narrow portion 11b having a low bending strength at an arbitrary position of the U-turn portion of the flexible 11 described later.

One end 1 of the flexible 11 thus formed
1e is fixed to the motor unit 10b of the electromagnetic diaphragm unit 10 attached to the second lens barrel 8, and the motor unit 10b
And the wiring pattern portion 11c of the flexible 11 are connected by soldering or the like. The sticking portion 11f of the flexible 11 is attached along the wall of the second lens barrel 8, and further provided on the second lens barrel 8 so as to extend in the optical axis direction. 2a, and extends rearward in the optical axis direction.

The U-turn portion 11d of the flexible 11 is U-turned forward in the optical axis direction with an appropriate curvature, and the bent portion 1
1 g of the guide tube 2 which is bent rearward in the optical axis direction at 1 g.
Affixed to the flexible guide 2c. After that, the drawer 11i of the flexible 11 is drawn out to the mount side, and its terminal end is connected to a connector or the like arranged on the electric circuit board 3.

Next, the operation of the interchangeable lens configured as described above will be described. When the photographer rotates the zoom operation tube 4, a cam groove 4 provided on the inner periphery of the zoom operation tube 4
b and the convex cam portion 5a provided on the rectilinear cylinder 5, and the linear key 6 and the guide cylinder 2 fixed to the rectilinear cylinder 5.
By engaging with the straight key guide groove provided on the outer circumference of
The rectilinear barrel 5 moves in the optical axis direction. Accordingly, the first lens barrel 7 and the first lens group also move in the optical axis direction.

By the movement of the rectilinear barrel 5 in the optical axis direction, the roller 9 located at the intersection of the convex cam portion 5b provided on the inner peripheral portion of the rectilinear barrel 5 and the cam groove 2b provided on the guide cylinder 2 is formed. In accordance with the movement of the cam intersection, it moves in the optical axis direction while rotating around the optical axis. Accordingly, the second lens barrel 8 and the second lens group / electromagnetic diaphragm unit 10 to which the rollers 9 are attached also move in the optical axis direction while rotating around the optical axis. From the above, the first
The positions of the lens group and the second lens group in the optical axis direction change, and the focal length of the lens changes.

In the interchangeable lens that performs the zoom operation as described above, the flexible lens 11 is deformed to absorb the extension amount of the second lens barrel 8. More specifically, as shown in FIGS. 3 and 4, the portion from the one end 11e of the flexible member 11 to the attaching portion 11f moves together with the second lens barrel 8, and the portion from the bent portion 11g to the drawer portion 11i is the first flexible member. Guide part 2c
(Guide tube 2). And U-turn part 1
The portion between 1d and the bent portion 11g absorbs the extension amount of the second lens barrel 8 while changing the position of the U-turn apex.

Here, the dotted line (A) shown in FIGS. 3 and 4 shows the shape of a conventional U-turn flexible having no narrow portion. The solid line (B) shows the narrow portion 11b as the U-turn portion 11.
Position 1 of d which is the end in the optical axis direction at the time of telephoto shown in FIG.
The shape of the flexible 11 of the present embodiment when provided at 1 s is shown. Further, the two-dot chain line (C) shows the U-turn part 11d.
Of the narrow flexible portion 11 near the second flexible guide portion 8a.
The figure shows the shape of the flexible 11 when b is provided.

As is apparent from these figures, in particular, FIG.
(B) <(A) <(C) the manner in which the U-turn portion 11d of the flexible 11 at the time of telephoto spreads. this is,
The flex 11 is due to the smallest radius of curvature in the narrow portion 11d.

Therefore, by adopting this embodiment (B), it is possible to prevent interference between the flexible 11 and the guide cylinder 2 and to minimize the space occupied by the U-turn portion 11d.

Further, in the present embodiment, (A) and (C) can be achieved without attaching a flexible holding plate to the guide cylinder 2 or increasing the length of the second flexible guide portion 8a as in the related art.
As described above, it is possible to prevent the U-turn portion 11d from expanding so as to protrude from the second flexible guide portion 8d. For this reason, the number of parts can be reduced and the assembling can be simplified and the cost can be reduced because the flexible holding plate is not provided. In addition, the length of the second flexible guide portion 8a is shortened so that a sufficient U-turn portion 1 is provided.
Since the entire length of the flexible 11 can be shortened while securing 1d, the space for arranging the flexible 11 can be reduced, and the interchangeable lens can be reduced in size.

In this embodiment, the case where the narrow portion 11b is formed in the U-turn portion 11d of the flexible 11 and the reinforcing pattern portion 11p is provided in a portion other than the narrow portion 11b has been described. It is also possible to provide only the portion and not provide the reinforcing pattern portion.

As a method of changing the flexural strength of the flexure, a method based only on the presence or absence of the reinforcing pattern can be considered. However, the amount of change in the bending strength due to the presence or absence of the reinforcing pattern is large, and it is difficult to finely adjust the bending shape. On the other hand, in the method of changing the width of the flexible member, the bending strength is gradually changed, so that the shape of the U-turn portion can be finely adjusted.

In this embodiment, the case where the flexible member 11 is disposed between the guide tube 2 and the second lens barrel 8 has been described. The present invention can be applied to a lens barrel in which a flexible member is arranged between members.

(Second Embodiment) Even if the narrow portion described in the first embodiment is provided at a position where the torsion of the flex occurs, it is an effective means for suppressing the spread of the flex.

FIG. 5 shows a state in which the flexible 12 is twisted. In FIG. 3A, a narrow portion 12a is formed in the U-turn portion of the flexible 12, and the narrow portion 1a is formed.
2a shows a state in which the flexible 12 is folded in the 180-degree direction. (B) shows a case where one end of the flexible 12 moves in a direction orthogonal to the folding direction.

As can be seen from the figure, the U-turn portion of the flexible 12 is twisted, but the deformation of the flexible 12 due to the twisting can be absorbed by the narrow portion 12a. For this reason, almost no deformation due to torsional bending is observed in portions other than the vicinity of the narrow portion 12a.

Therefore, even if a torsional bending force acts on the flexible 12, deformation of the entire flexible 12 can be easily predicted,
The method of pressing the flexible 12 becomes easy.

A reinforcing pattern portion for suppressing twisting may be formed in a portion of the flexible 12 other than the narrow portion 12a.

[0059]

As described above, according to the first aspect of the present invention, when the movable lens barrel member is farthest from the fixed lens barrel member in the U-turn portion of the flexible printed wiring board. Since the narrow portion is formed at the end portion in the optical axis direction), the curvature of the narrow portion of the flexible printed wiring board can be made smaller than that of other portions, and the entire U-turn portion can be widened. Can be suppressed. For this reason, it is possible to prevent interference between the flexible member and the lens barrel member and to prevent the flexible member from being caught with a simple configuration. In addition, since a flexible holding plate is not required and a portion for holding the flexible printed wiring board on the fixed lens barrel member can be integrally formed,
The reduction in the number of parts enables simplification of assembly and cost reduction.

Further, according to the present invention, the portion of the flexible printed wiring board adjacent to the U-turn portion is held by a wiring board holding portion formed on the movable lens barrel member so as to extend in the optical axis direction, for example, by being attached. In such a case, even if the flexible holding plate is abolished or the length of the wiring board holding portion is shortened, it is possible to prevent the U-turn portion from spreading beyond the wiring board holding portion. If the length of the wiring board holding portion is reduced, the entire length of the flexible printed wiring board can be reduced while securing a sufficiently long U-turn portion. Therefore, the arrangement space for the flexible printed wiring board can be reduced, and as a result, the lens barrel can be downsized.

According to the second aspect of the present invention, since the narrow portion is formed in the portion of the flexible printed wiring board where the twist occurs, the deformation of the flex due to the torsion is largely absorbed by the narrow portion. Therefore, the deformation of the entire flexible printed wiring board due to the twisting force can be easily predicted. For this reason, the method for holding the flexible printed wiring board can be simplified.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a configuration of an interchangeable lens according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a shape of a flexible printed wiring board in the interchangeable lens.

FIG. 3 is a partially enlarged view showing a state of deformation of a flexible printed wiring board according to a zoom operation (at the time of widening) of the interchangeable lens.

FIG. 4 is a partially enlarged view showing a state of deformation of a flexible printed wiring board according to a zoom operation (telephoto) of the interchangeable lens.

FIG. 5 is an explanatory diagram of a flexible printed wiring board in an interchangeable lens according to a second embodiment of the present invention.

FIG. 6 is a side sectional view showing a configuration of a conventional interchangeable lens.

FIG. 7 is a partially enlarged view showing a state of deformation of a flexible printed wiring board according to a zoom operation (at the time of widening) of the conventional interchangeable lens.

FIG. 8 shows a zoom operation of the conventional interchangeable lens (telephoto mode).
FIG. 6 is a partially enlarged view showing a state of deformation of the flexible printed wiring board according to the above.

FIG. 9 is a partially enlarged view showing a state of deformation of a flexible printed wiring board according to a zoom operation (at the time of widening) when the flexible holding plate is abolished in the conventional interchangeable lens.

FIG. 10 is a partially enlarged view showing a state of deformation of a flexible printed wiring board according to a zoom operation (at the time of telephoto) when a flexible holding plate is abolished in the conventional interchangeable lens.

[Explanation of symbols]

 1, 101: mount cylinder 2, 102: guide cylinder 3, 103: electric circuit board 4, 104: zoom operation cylinder 5, 105: straight advance cylinder 6, 106: straight advance key 7, 107: 1 group barrel 8, 108: 2 group barrel 9, 109: roller 10, 110: electromagnetic diaphragm unit 11, 12, 111: flexible printed wiring board 11b, 12a: narrow portion 11p: reinforcing pattern portion 112: flexible holding plate

Claims (7)

[Claims] A flexible printed wiring board for electrically connecting a fixed barrel member and a movable barrel member movable in an optical axis direction with respect to the fixed barrel member; A lens barrel provided with a U-turn part whose bending apex moves in the optical axis direction in accordance with the movement of the lens barrel member, wherein a narrow part is formed in the U-turn part. 2. The method according to claim 1, wherein the narrow portion is formed at a position in the U-turn portion where the movable barrel member is located at an end in the optical axis direction when the movable barrel member is farthest from the fixed barrel member. The lens barrel according to claim 1. 3. The lens barrel according to claim 1, wherein a reinforcing pattern for suppressing bending is formed in a portion other than the narrow portion in the U-turn portion. 4. The fixed lens barrel member according to claim 1, wherein a first wiring board holding portion for holding a portion of the flexible printed wiring board adjacent to the U-turn portion is integrally formed. The lens barrel according to any one of the above. 5. The movable lens barrel member is provided with a second wiring board holding portion that extends in the optical axis direction and holds a portion of the flexible printed wiring board adjacent to the U-turn portion. Item 5. The lens barrel according to any one of Items 1 to 4. 6. A flexible printed wiring board for electrically connecting a fixed barrel member and a movable barrel member movable with respect to the fixed barrel member, wherein the flexible printed wiring board is moved in accordance with the movement of the movable barrel member. A lens barrel in which a twist is generated in a printed wiring board, wherein a narrow portion is formed in a portion of the flexible printed wiring board where the twist occurs. 7. The lens barrel according to claim 6, wherein a reinforcing pattern for suppressing twisting is formed on a portion other than the narrow portion of the flexible printed wiring board.