JPH10170806A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel that gives adequate rotational torque without having unevenness to a focusing operation ring, and that realizes comfortable operating feeling. SOLUTION: This lens barrel is provided with a fixed lens barrel 6, a rotating member 7, which is rotatably attached to the fixed lens barrel and whose position in the direction of an optical axis is limited, and an adjusting member 8 provided at either of the rotating member and the fixed lens barrel and adjusting rotational torque necessitated so as to rotate the rotating member by pressing the other of the rotating member or the fixed lens barrel in the direction of the optical axis. The adjusting member 8 is a member having only a specified angle in a circumferential direction around the optical axis and is provided only at either the rotating member 7 or the fixed lens barrel 6.

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 mechanism for adjusting a rotation torque required for rotating a focusing operation ring or the like and having improved operation feeling.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing an example of a conventional lens barrel. In the drawing, a focusing lens group holding member 3 is a member that holds the focusing lens group 1 and has an interlocking pin 3 on its outer peripheral surface.
a is integrally fixed. The fixed lens barrel 4 is a member fixed integrally with the appearance fixed barrel 6, and has a rectilinear groove 4a that engages the interlocking pin 3a and guides in the optical axis direction.

The cam ring 5 is fitted around the outer periphery of the fixed lens barrel 4 so as to be rotatable around the optical axis, and has a plurality of cam grooves 5a and one gear portion 5b. The cam groove 5a is a cam groove for driving the focusing lens group 1 in the optical axis direction, and the tip of the interlocking pin 3a is fitted therein. Gear part 5b
Is a gear provided at the rear end of the cam ring 5 at a predetermined angle in the circumferential direction, and is a portion to which power from the motor is transmitted during automatic focusing. An elastic member 28 is provided at the same position in the optical axis direction as the gear 5b and at the portion of the cam ring 5 where no gear processing is performed. The elastic member 28
The tip 28a is biased against the outer peripheral surface of the fixed lens barrel 4.

The fixed appearance barrel 6 supports the focusing operation ring 7 so as not to move in the optical axis direction but to be rotatable around the optical axis. The focusing operation ring 7 is used when performing a focusing operation.
It is a member that is manually rotated from the outside. A focusing interlocking member 11 is attached to the inner periphery of the focusing operation ring 7. The focusing interlocking member 11 has its distal end 11 a engaged with the cam ring 5. Therefore, the focusing operation ring 7, the focusing interlocking member 11, and the cam ring 5 are integrated around the optical axis.

In the lens barrel shown in FIG. 4, when the focusing operation ring 7 is rotated, the rotational motion is transmitted to the cam ring 5 via the focusing interlocking member 11, and the cam ring 5 is moved. And rotate together. At this time, the elastic member 28 is
Move while being in contact with the outer peripheral surface of the lens unit, frictional resistance is generated between the elastic member 28 and the fixed lens barrel 4, and the focusing operation ring 7 has an operation feeling of an appropriate weight. The rotational movement of the cam ring 5 is
Cam groove 5a, rectilinear groove 4a of fixed barrel 4, and interlocking pin 3a
Is converted into a linear motion in the optical axis direction, and transmitted to the focusing lens group holding member 3. As a result, the focusing lens group holding member 3 and the focusing lens group 1 are moved in the optical axis direction,
A focusing operation is performed.

As described above, in the conventional lens barrel, the cam ring 5 is provided with the elastic member 28, and the fixed barrel 4 is fixed to the optical axis so that an operation feeling of appropriate weight is generated for the focusing operation. It was urging towards.

[0007]

However, in the conventional lens barrel described above, the elastic member 28 urges the fixed barrel 4 toward the optical axis. For this purpose, the fixed lens barrel 4
There is a problem that the roundness is reduced so that the cam cylinder and the focusing operation ring do not rotate smoothly.

In order to solve the above problem, there has been a case where a so-called wave washer (wave type washer) is used to adjust the operational feeling of the focusing operation. More specifically, a wave washer is inserted between the focusing operation ring 7 and the fixed lens barrel 4, and a rotational torque is applied to the focusing operation ring by frictional force generated in the wave washer to perform an operation during the focusing operation. Adjust the feeling. In this method, since the wave washer urges the focusing operation ring and the fixed lens barrel in the optical axis direction, deformation that hinders rotation of the focusing operation ring is less likely to occur in the fixed barrel. However, when a wave washer is used, it is necessary to provide an end face between the focusing operation ring and the fixed lens barrel for bringing the wave washer into contact over the entire circumference around the optical axis. Moreover, this end face must not have irregularities. This is because, when there is unevenness, unevenness occurs in the rotational torque generated by the wave washer. However, since the lens barrel is a complex assembly of a plurality of parts, depending on its type, it is impossible to provide an end face without unevenness over the entire circumference around the optical axis, such as a fixed barrel, There was a problem that the wave washer could not be attached in some cases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens barrel which applies a proper rotation torque to a focusing operation ring without unevenness and realizes a comfortable operation feeling.

[0010]

According to a first aspect of the present invention, a fixed lens barrel and a position in an optical axis direction rotatably mounted on the fixed lens barrel are limited. A rotating member, provided on one of the rotating member or the fixed barrel, for urging the other of the rotating member or the fixed barrel in the direction of the optical axis to rotate the rotating member An adjusting member for adjusting a required rotating torque, wherein the adjusting member is a member having only a predetermined angle in a circumferential direction around the optical axis, and is provided on one of the rotating member and the fixed lens barrel. It is characterized by having been done.

According to a second aspect of the present invention, in the lens barrel according to the first aspect, the adjusting member includes a fixed portion fixed to one of the rotating member and the fixed barrel, and a single piece attached to the fixed portion. And a leaf spring portion having a shape which is held and supported and extends from the fixing portion along the circumferential direction, and has a spring property in the direction of the optical axis. According to a third aspect of the present invention, in the lens barrel according to the second aspect, the adjusting member extends from the fixing portion in a clockwise direction around the optical axis and in a counterclockwise direction. The above-mentioned leaf spring part is provided.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a lens barrel according to the present invention will be described in more detail with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of a lens barrel according to the present invention. The lens barrel of the present embodiment has the same basic configuration as the conventional lens barrel described with reference to FIG. Therefore, in the following description, for the portion that performs the same function as in the conventional lens barrel,
The same reference numerals are given to omit duplicate explanations as appropriate, and only different points will be described.

The lens barrel according to the present embodiment includes an elastic member 28.
Instead, an elastic member 8 is fixed to the inner periphery of the focusing operation ring 7 by a fixing screw 9 and a nut member 10, and a part of the elastic member 8 is brought into frictional contact with the appearance fixed lens barrel 6, so that the focusing operation ring can be appropriately adjusted. This is different from the conventional lens barrel in that a large rotational torque is applied.

FIG. 2 is a two-sided view of the elastic member 8 and FIG. 3 is a perspective view of the elastic member 8. Elastic member 8
Is composed of a mounting portion 8b and a contact portion 8a. The attachment portion 8b is a plate-like portion attached to the inner peripheral surface of the focusing operation ring 7. The mounting portion 8 b has a surface parallel to the optical axis and has a shape bent along the inner peripheral surface of the focusing operation ring 8. The mounting portion 8b has two mounting holes 8c. The mounting hole 8c is a hole for passing the screw 9 when fixing the elastic member 8 to the focusing operation ring 7, and has a larger diameter than the screw 9.

The contact portion 8a is provided on the end face 6a of the externally fixed lens barrel 6.
This is a plate-shaped portion that contacts the optical axis and urges the optical axis rearward. The elastic member 8 applies an appropriate rotational torque to the focusing operation ring by bringing the contact portion 8a into contact with the fixed appearance barrel 6 and generating a circumferential frictional force. Here end face 6a
Is a surface perpendicular to the optical axis provided at the front end of the optical axis of the external appearance fixed lens barrel 6. The contact portion 8a is a cantilever whose one end is supported at the center of the mounting portion 8b and extends from there along a circumference around the optical axis. The reason why the contact portion 8a is a cantilever is to provide the contact portion 8a with an appropriate spring property. Further, the contact portion 8a is formed to extend along the circumference around the optical axis because the width of the contact portion 8a in the radial direction of the lens barrel is suppressed, and the provision of the contact portion 8a allows the lens barrel to be formed. This is to prevent the size from increasing in the radial direction.

One of the two contact portions 8a extends in a clockwise direction, and the other extends in a counterclockwise direction. Therefore, the elastic member 8 has a symmetrical shape when viewed from the optical axis direction. The reason why the shape is symmetrical in this manner is to prevent the rotational torque applied to the focusing operation ring 7 from the elastic member 8 from being varied depending on the rotation direction of the focusing operation ring 7 and to prevent unevenness in operation feeling. is there. The surface of the contact portion 8a is a curved surface that is convex toward the contact end surface 2a. Therefore, the contact portion 8a is in local contact with the end face 2a, and even if the contact portion 8a has a dimensional variation,
The area where the contact portion 8a contacts the end face 2a does not change much. This is because even if the size of the elastic member 8 varies,
This is designed so that a large difference does not occur in the rotational torque applied to the focusing operation ring 7.

In this embodiment, as a preferred example, a plurality of elastic members 8 are attached to the inner periphery of the focusing operation ring. The reason why the plurality of elastic members 8 are attached is to prevent a force in a direction inclining with respect to the optical axis from being applied to the focusing operation ring 7, and to sufficiently increase the rotational torque applied to the focusing operation ring 7. It is to be. The elastic member 8 is basically
It is preferable to provide them at equal intervals in the circumferential direction. However, FIG.
As shown in (2), when there is an obstacle such as the focusing interlocking member 11 at a position where the elastic member 8 is to be attached, the position is shifted in the circumferential direction to avoid the obstacle. Is also good. That is, since the elastic member 8 has a complicated structure, it can be attached to and used in a lens barrel in which a space for inserting an annular member such as a wave washer cannot be secured. Depending on the lens barrel used, only one elastic member 8 may be used.

(Other Embodiments) The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the scope of the claims of the present invention. It is included in the technical scope of the invention.

For example, in the above embodiment, the case where the operation torque of the focusing operation ring is adjusted has been described as an example. However, the technical idea of the present invention is also applied to the case where the operation torque of the zoom operation ring is adjusted. It is possible. Further, in the above embodiment, only an example of the shape of the elastic member 8 is shown, and the portion fixed to the focusing operation ring and the fixed lens barrel are brought into contact with each other, and the appropriate friction is made in the circumferential direction around the optical axis. The elastic member 8 may have another shape as long as it has a portion that generates a force.

[0020]

As described above in detail, according to the first aspect of the present invention, even in a lens barrel having a complicated structure in which a wave washer or the like cannot be used, deformation that hinders smooth rotation can be prevented by a rotating member or the like. It is possible to adjust the rotation torque required to rotate the rotating member without causing the rotation. According to the second aspect of the present invention, by attaching the adjustment member, the lens barrel does not become large in the radial direction. According to the third aspect of the invention, the adjusting member applies a constant rotational torque to the rotating member regardless of the rotating direction of the rotating member.

[Brief description of the drawings]

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

FIG. 2 is a two-sided view showing an elastic member 8;

FIG. 3 is a perspective view of an elastic member 8;

FIG. 4 is a sectional view of a conventional lens barrel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Focusing lens group 2 Fixed lens group 3 Focusing lens group frame 3a Interlocking pin 4 Fixed lens barrel 4a Straight running groove 5 Cam ring 5a Cam groove 5b Gear 6 Appearance fixed lens barrel 7 Focusing operation ring 8 Elastic member 9 Screw 10 Nut 11 Focusing interlocking member 28 Elastic member

Claims (3)

[Claims] A fixed member that is rotatably attached to the fixed lens tube and whose position in the optical axis direction is restricted; provided on one of the rotating member and the fixed lens tube; An adjusting member that adjusts a rotational torque required to rotate the rotating member by urging the other of the rotating member or the fixed barrel in the direction of the optical axis, the adjusting member includes: A lens barrel, which is a member having only a predetermined angle in a circumferential direction around an optical axis, and is provided on one of the rotating member and the fixed barrel. 2. The lens barrel according to claim 1, wherein the adjusting member is fixed to one of the rotating member and the fixed lens barrel, and is cantilevered by the fixing portion, and is fixed. And a leaf spring portion having a shape extending in the circumferential direction from the portion and having a spring property in the direction of the optical axis. 3. The lens barrel according to claim 2, wherein the adjusting member is configured such that the leaf spring portion extends clockwise from the fixing portion around an optical axis, and the leaf spring extends counterclockwise. And a lens barrel.