JPH09203841A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the number of components by providing a lens barrel, equipped with a mount position changing mechanism including a clutch mechanism, with a clutch mechanism equipped with a guide function which moves a lens barrel main body straight along the optical axis at the time of clamping. SOLUTION: On the inner peripheral surface of a mount member which is provided with a lens barrel main body 2 inside coaxially, plural recessed grooves 1b which extend along the optical axis are formed as guide grooves and on the outer peripheral surface of the lens body main body 2, a projection part 2a which selectively engages a recessed groove 1b is slidable in the recessed groove 1b along the optical axis is formed, thus constitute a clutch mechanism 6 equipped with a guide function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel for optical equipment, and more particularly to a lens barrel having a mount position changing mechanism.

[0002]

2. Description of the Related Art For example, in a lens barrel for a video camera, a mounting angle position around an optical axis of a lens barrel main body which is movable in an optical axis direction with respect to a mount member mounted on an optical apparatus main body can be changed. Required to do so.

Therefore, a lens barrel having such a mount position changing mechanism is provided with a clutch mechanism that can be engaged at different rotational positions of the lens barrel body with respect to the mount member. The clutch mechanism is fastened by the elastic force of the elastic member to restrict the rotation of the lens barrel main body with respect to the mount member, and moves the lens barrel main body forward along the optical axis against the elastic force of the elastic member. The fastening operation is released by the operation of moving the lens barrel body so that the lens barrel body can be rotated and the mounting angle position of the lens barrel body with respect to the mount member can be changed.

Therefore, in the conventional lens barrel of this type,
An intermediate member called a joint ring, which is rotatable and movable in the optical axis direction with respect to the mount member and is movable along the optical axis, is interposed between the mount member and the lens barrel body, and the joint ring is provided. The clutch mechanism is provided between the mount member and the mount member, and a guide mechanism (straight-moving key) for linearly moving the lens barrel main body in the optical axis direction in the engaged state of the clutch mechanism is provided between the joint ring and the lens barrel main body. It is provided.

Further, a focus ring for performing a focusing operation by moving the lens barrel main body in the optical axis direction with respect to the mount member is interposed between the joint ring and the lens barrel main body, and the elastic member is a mirror. The joint ring is elastically pressed toward the mount member via the trunk body and the focus ring to engage the clutch mechanism (actually, 4-18).
No. 814).

[0006]

However, in the conventional lens barrel having the mount position changing mechanism as described above, an intermediate member such as a joint ring is interposed between the mount member and the lens barrel body. A clutch mechanism is provided between the ring and the mount member, and a guide mechanism for linearly moving the lens barrel body in the optical axis direction when the clutch mechanism is engaged is provided between the ring and the lens barrel body. Therefore, there is a problem that the structure becomes complicated and the number of parts increases.

Further, since the engaging force of the clutch mechanism is obtained by the elastic force of the elastic member, the required clutch engaging force cannot be obtained when the elastic force of the elastic member is weakened due to long-term use. There was also a problem.

In view of the above circumstances, a first object of the present invention is to provide a lens barrel having a mount position changing mechanism which has a simplified structure and can reduce the number of parts.

A second object of the present invention is to provide a lens barrel which can obtain the fastening force of the clutch mechanism without depending on the elastic force of the elastic member.

[0010]

A lens barrel according to the present invention includes a mount member mounted on an optical apparatus body, and a lens barrel provided so as to be rotatable about an optical axis and movable in the optical axis direction. The main body, an elastic member provided between the mount member and the lens barrel body, can be fastened at each of different rotational positions of the lens barrel body with respect to the mount member, by this fastening, the rotation of the lens barrel body is restricted, And a clutch mechanism that can be disengaged by an operation of moving the lens barrel body forward along the optical axis against the elastic force of the elastic member, wherein the clutch mechanism includes a mount member and the lens barrel. It is characterized in that it is provided between the main body and the main body, and that this clutch mechanism has a guide function for linearly moving the lens barrel main body in the optical axis direction when the clutch mechanism is engaged.

In this case, the lens barrel body is coaxially provided inside the mount member, and the inner peripheral surface of the mount member and the outer peripheral surface of the lens barrel body are engaged with each other to rotate the lens barrel body. By forming the concave portion and the convex portion that regulate and are mutually slidable in the optical axis direction in the engaged state, it is possible to configure a clutch mechanism having a guiding function.

More specifically, a plurality of concave grooves extending in the optical axis direction are formed as guide grooves on one of the inner peripheral surface of the mount member or the outer peripheral surface of the lens barrel body, and the inner peripheral surface of the mount member or A clutch mechanism having a guide function is formed on the other outer peripheral surface of the lens barrel body by forming a convex portion that is selectively engaged with the concave groove and is slidable in the concave groove in the optical axis direction. Can be configured.

Further, a focus ring for performing a focusing operation by moving the lens barrel main body in the optical axis direction with respect to the mount member is rotatably interposed between the mount member and the lens barrel main body. A rotary sliding surface may be formed between the mount member and the elastic member, which are in contact with each other by the elastic force of the elastic member.

[0014]

According to the present invention, the above clutch mechanism is
Since it is provided between the mount member and the lens barrel main body and has a guide function for linearly moving the lens barrel main body in the optical axis direction at the time of fastening the same, there is a conventional gap between the mount member and the lens barrel main body. It is not necessary to interpose an intermediate member such as a joint ring. Therefore, the structure is simplified and the number of parts can be reduced.

Further, the inner peripheral surface of the mount member and the outer peripheral surface of the lens barrel main body are engaged with each other to regulate the rotation of the lens barrel main body, and they can slide in the optical axis direction in the engaged state. Since the concave and convex portions are formed to form the clutch mechanism, the fastening force of the clutch mechanism can be obtained only by the engagement between the convex portion and the concave portion without depending on the elastic force of the elastic member. It is possible to always obtain a strong and stable clutch engagement force.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial vertical sectional view showing an essential part of an embodiment of a lens barrel according to the present invention by cutting along a vertical plane including an optical axis, and FIG. 2 is a line II-II in FIG. FIG.

In the figure, this lens barrel is a mount member 1 which is mounted on a camera body by mount screws 1a.
And a lens barrel body 2 which is provided coaxially inside the mount member 1 and is movable in the optical axis direction and in a rotation direction around the optical axis with respect to the mount member 1, the mount member 1 and the lens barrel body 2. Between the mount member 1 and the lens barrel body 2, which is rotatably interposed between the lens and the focus ring 3 for moving the lens barrel body with respect to the mount member in the optical axis direction to perform a focusing operation. The lens barrel body 2 is placed between the rear side (see FIG. 1).
It is composed of an elastic member 4 urging to the right) and a lens group 5 and the like housed in the lens barrel body 2.

As is clear from FIG. 2, 16 concave grooves 1b extending through the mount member 1 in the optical axis direction are formed on the inner peripheral surface of the mount member 1 at equal angular intervals (22.5 °). And the concave groove 1 is formed on the outer peripheral surface of the lens barrel body 2.
At least four convex portions 2 which are inserted into the groove b from the front end (the left end in FIG. 1) by a predetermined distance and can slide in the concave groove 1b in the optical axis direction.
The a is formed at 90 ° intervals to form a dog clutch type clutch mechanism 6. Therefore, the clutch mechanism 6 can be engaged at any mutual angular position which is an integral multiple of 22.5 °, whereby the mounting angular position of the lens barrel body 2 with respect to the mount member 1 is an integral multiple of 22.5 °. Can be changed to any angular position.

The number of the convex portions 2a provided on the outer peripheral surface of the lens barrel body 2 can be increased to the same number as the number of the concave grooves 1b (16) provided on the inner peripheral surface of the mount member 1.

The clutch mechanism 6 is biased in the fastening direction by the elastic force of the elastic member 4 and is always held at the fastening position to regulate the rotation of the lens barrel body 2 and to prevent the lens barrel body from rotating. It also constitutes a guide mechanism that allows only the linear movement of the second optical axis. Then, the engagement state of the clutch mechanism 6 is released by the operation of moving the lens barrel body 2 forward along the optical axis against the elastic force of the elastic member 4,
The lens barrel body 2 becomes rotatable.

The focus ring 3 is screwed by a helicoid screw 7 formed between the inner peripheral surface of the focus ring 3 and the outer peripheral surface of the lens barrel body 2, and the focus ring 3 is made of an elastic member 4. Elastic force of the elastic member 4 applied via the lens barrel main body 2 and the helicoid screw 7 is pushed rearward toward the mount member 1, and the rear surface of the focus ring 3 and the front surface of the mount member 1 are A rotary sliding surface 8 is formed between the two.

Therefore, the focus ring 3 and the mount member 1 are rotated and slid by the elastic force of the elastic member 4.
The clutch mechanism 6 is held in the engaged state in a state in which the clutch mechanism 6 is in close contact with the clutch mechanism 6.

When the focus ring 3 is rotated, the lens barrel body 2 whose rotation is regulated by the clutch mechanism 6 in the engaged state moves in the optical axis direction to perform a focusing operation. The convex portion 2a of the lens barrel body 2 that constitutes one member of the clutch mechanism 6 is
Groove 1b of the mount member 1 constituting the other member of
The lens barrel body 2 is configured to move straight in the optical axis direction by being slid in the concave groove 1b in the optical axis direction.

The engagement distance of the convex portion 2a of the lens barrel body 2 with respect to the groove 1b of the mount member 1 is sufficient even when the lens barrel body 2 is moved forward as much as possible for focusing. It is set so that a sufficient clutch engagement force can be obtained.

As is clear from the above description, in the present embodiment, the clutch mechanism 6 has a guide function for moving the lens barrel body 2 straight in the optical axis direction. It is not necessary to interpose an intermediate member such as a joint ring between the lens barrel 1 and the lens barrel body 2, and the number of parts can be reduced.

In the present embodiment, the clutch mechanism 6 is biased in the engaging direction by the elastic force of the elastic member 4 and is held at the engaging position. Is not the elastic force of the elastic member 4,
Since the convex portion 2a of the lens barrel body 2 and the concave groove 1b extending in the optical axis direction of the mount member 1 are engaged with each other, a strong and stable clutch engaging force can always be obtained.

Further, since the rotary sliding surface 8 is formed between the focus ring 3 and the mount member 1 so as to come into contact with each other by the elastic force of the elastic member 4, a smoother operation of the focus ring 3 can be achieved. Can be expected.

In this embodiment, a concave groove 1b extending in the optical axis direction is formed as a guide groove on the mount member 1 side, and a convex portion 2a engaged with the concave groove 1b has a lens barrel body 2 formed therein.
Although it is formed on the side, on the contrary, it is also possible to provide a concave groove on the lens barrel body 2 side and a convex portion on the mount member 1 side.

Further, it is possible to extend the convex portion side in the optical axis direction to form a guide ridge, and engage the concave portion having a short length in the optical axis direction.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view showing a main part of an embodiment of a lens barrel according to the present invention by cutting along a vertical plane including an optical axis.

FIG. 2 is a sectional view taken along line II-II in FIG.

[Explanation of symbols]

 1 mount member 1a mount screw 1b concave groove 2 lens barrel body 2a convex portion 3 focus ring 4 elastic member 5 lens group 6 clutch mechanism 7 helicoid screw 8 rotational sliding surface

Claims (4)

[Claims] 1. A mount member mounted on an optical device body, a lens barrel body rotatably around an optical axis and movable in the optical axis direction, the mount member and the lens barrel body. And an elastic member provided between the lens barrel body and the mount member at different rotational positions with respect to the mount member. The fastening restricts the rotation of the lens barrel body, and A lens barrel comprising: a clutch mechanism that can be disengaged by an operation of moving forward along an optical axis against an elastic force of an elastic member, wherein the clutch mechanism includes the mount member and the lens barrel body. And a guide function for linearly moving the lens barrel main body in the optical axis direction when the lens barrel is fastened. 2. The lens barrel body is coaxially provided inside the mount member, and the lens barrel body is engaged with each other between an inner peripheral surface of the mount member and an outer peripheral surface of the lens barrel body. 2. The lens mirror according to claim 1, wherein the clutch mechanism is configured by forming a concave portion and a convex portion that regulate the rotation of the main body and that are mutually slidable in the optical axis direction in the engaged state. Torso 3. A plurality of concave grooves extending in the optical axis direction are formed as guide grooves on one of the inner peripheral surface of the mount member or the outer peripheral surface of the lens barrel body, and the inner peripheral surface of the mount member or the lens barrel body is formed. On the other side of the outer peripheral surface of the clutch mechanism, a convex portion that selectively engages with the concave groove and is slidable in the concave groove in the optical axis direction is formed to constitute the clutch mechanism. The lens barrel according to claim 2. 4. A focus ring that moves the lens barrel body in the optical axis direction with respect to the mount member to perform a focusing operation is rotatably interposed between the mount member and the lens barrel body. 4. The lens according to claim 1, wherein a rotary sliding surface is formed between the focus ring and the mount member, the rotary sliding surfaces being in contact with each other by the elastic force of the elastic member. Lens barrel.