JPH1020176A - Collapsible mount type interchangeable lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collapsible mount type interchangeable lens barrel excellent in operability and attaching/detaching performance while preventing a situation that only an operation ring is rotated in the case of attaching or detaching the lens barrel to/from a camera body. SOLUTION: A projected part 2e having a 1st contact surface 2d at its edge is formed on the outer surface of a fixed barrel 2 so that the rotational resistance of a zoom ring (operation ring) 5 may be made larger in a collapsing operation area θ2 than in a zooming operation area (main operation area) θ1 . Furthermore. a projected part 5c having a 2nd contact surface 5b coming in contact with the 1st contact surface 2d only in the area θ1 at its edge is formed on the inner surface of the ring 5, so that rotating operational force in the area θ2 is made stringer than the rotating operational force for attaching or detaching the lens barrel 1 to/from the camera body 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retractable interchangeable lens barrel in which the entire length in the optical axis direction can be in a retracted state shorter than the shortest state during photographing.

[0002]

2. Description of the Related Art A retractable interchangeable zoom lens barrel has conventionally been provided as an interchangeable lens barrel for a single-lens reflex camera which is excellent in portability and storage when not in use (for example,
See JP-A-2-25815). The retractable zoom lens barrel is configured to rotate the zoom ring in one direction during non-photographing so that at least a part of the photographing lens (front lens) and its holding frame are retracted toward the camera body in the optical axis direction. The entire length in the direction can be set to a state (retracted state) shorter than the shortest state at the time of photographing.

[0003]

The retractable zoom lens barrel has a short overall length in the retracted state.
The zoom ring often takes time to attach to or remove from the camera body. In this case, if the user attaches or removes the lens barrel to or from the camera body with only the zoom ring, the zoom ring may rotate only while trying to rotate the entire lens barrel. Can be In such a case, there is a possibility that the operational feeling is poor and the lens barrel is not completely attached or detached, but only changes between the photographing state and the retracted state. Such a problem is not limited to a zoom lens barrel that performs a collapsing operation with a zoom ring, but includes an operation ring,
This may occur in a lens barrel in which the retracting operation is performed by the operation ring.

Accordingly, a technical problem to be solved by the present invention is that when the lens barrel is attached to or detached from the camera body, only the operating ring does not rotate, and the retractable replacement is excellent in operability and detachability. The object is to provide a lens barrel.

[0005]

The retractable interchangeable lens barrel according to the present invention can assume a retracted state in which the entire length in the optical axis direction is shorter than the shortest state during photographing by turning the operation ring. Is a retractable interchangeable lens barrel that is configured to be detachable with respect to the camera body,
In order to solve the above-mentioned technical problem, a resistance means for increasing the rotation resistance of the operation ring in the retracted operation area from the main operation area is provided, and the rotational operation force in the retracted operation area is controlled by the lens barrel with respect to the camera body. It is characterized in that it is set to be larger than the rotational operation force for attaching and detaching.
As the operation ring, for example, a zoom ring for a zoom operation, a focus ring for focusing, or a ring for performing various other operations can be used.

In the above configuration, since the rotational operation force in the collapsible operation area is larger than the rotational operation force for attaching and detaching the lens barrel, the operation of attaching the lens barrel to the camera body with only the operation ring is required. When performing the operation, the operation ring alone does not rotate, and the entire lens barrel can be rotated. Therefore, at this time, the lens barrel does not change from the retracted state to the photographing state, and the lens barrel can be completely mounted. Also, if you further rotate the operation ring,
This time, since the lens barrel itself does not rotate, only the operation ring rotates, and the lens barrel changes to a shooting state.

On the other hand, the camera body is generally provided with a lock mechanism for holding the lens barrel mounted, and a lock button for releasing the lock mechanism. The lens barrel does not come off. For this reason, when removing the lens barrel from the camera body, turn the operation ring to the full position without pressing the lock button to change the lens barrel to the collapsed state, and then press the lock button and move the lens barrel in the same direction. With a continuous operation of turning, the lens barrel can be removed and simultaneously retracted. As described above, according to the above-described configuration, it is possible to solve the problems related to operability and detachability of the retractable interchangeable lens barrel.

[0008] In the above configuration, the resistance means may include:
A first contact surface formed on the outer surface of the fixed barrel of the lens barrel, and a second contact surface formed on the inner surface of the operation ring so as to contact the first contact surface only in the main operation area. The above-mentioned problem can be solved without complicating the configuration by making the two contact surfaces, for example, a surface provided with fine irregularities or using a flocking cloth.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A retractable interchangeable lens barrel according to an embodiment of the present invention will be described below in detail with reference to FIGS. This lens barrel is a zoom lens barrel, and FIGS. 1 and 2 are central sectional views along the optical axis of this zoom lens barrel. FIG. 1 shows a wide (wide-angle) photographing lens.
FIG. 2 shows a state in which the taking lens is in the retracted position.

As shown in FIG.
Is a substantially cylindrical fixed barrel 2 and a front group lens moving frame 3 provided inside the fixed barrel 2 and holding the front group lens L1.
A rear-group lens moving frame 4 provided inside the fixed barrel 2 and holding the rear-group lens L2 behind the front-group lens moving frame 3; and a zoom ring (operation ring) provided on the outer periphery of the fixed barrel 2. ) 5 and a cam ring 6 and a linear guide cylinder 7 provided between the fixed barrel 2 and the front group lens moving frame 3 and the rear group lens moving frame 4. A protective glass 3a is attached to the front of the front lens group moving frame 3, and an aperture mechanism 14 (details of the structure are omitted) is provided to the front of the rear lens group moving frame 4.

The zoom ring 5 is rotatable around the optical axis L with respect to the fixed barrel 2 and is attached so as not to move in the optical axis direction. An engagement groove 5a extending in the optical axis direction is formed in the inner surface of the zoom ring 5, and the engagement groove 5a is provided in the cam ring 6 on the camera body 15 (FIG. 6) side (the right side in FIG. 1). A pin 8 implanted on the outer surface of the end of the slidably engages. In addition, on the outer periphery of the zoom ring 5,
A rubber ring 9 for non-slip is mounted.

As shown in FIG. 3 (FIG. 3 (a) is a retracted position, FIG. 3 (b) is a wide position) which is a cross-sectional view of the fixed cylinder 2 and the zoom ring 5 at right angles to the axis. 2, the cam ring 6 is configured to rotate within a range of the same angle θ as the rotation range of the cam ring 6. One end of the rotation range (A in FIG.
The end on the directional side) is at the retracted position, and the other end (the end on the B direction side in the drawing) is at the tele position. The rotation range θ is a zoom operation area (main operation area) θ from the tele position to the wide position.
₁ and consists of a collapsed manipulating area theta ₂ Metropolitan except for the zoom operation zone theta _1. Then, the rotational resistance of the zoom ring 5 is
As resistance means than zooming range theta ₁ to increase the retraction operation zone theta _2, the outer surface of the fixed tube 2, together with the projecting portion 2e having a first contact surface 2d is formed on the tip, the inner surface of the zoom ring 5 the, in contact with the first contact surface 2d only in the retracted manipulating area theta _2, the second contact surface 5b on the tip
Is protruded.

The contact surfaces 2d and 5b may be formed so as to be smooth and pressed against each other, but it is also possible to adhere a flocking cloth or roughen the surface. Even if taking any of these methods, so that the rotational operation force of the zoom ring 5 in the retracted manipulating area theta ₂ is greater than the rotational operation force of the mounting and removal of the zoom lens barrel 1 to the camera body, both Protrusions 2e and 5c are formed.

On the other hand, a male helicoid screw 6a is engraved on the outer surface of the cam ring 6 on the camera body 15 side. Screwed to the screw 2a. Camera ring 15 side of cam ring 6 (right side in FIG. 1)
The pin 8 implanted on the outer surface of the end portion of the zoom ring 5 penetrates a relief hole 2b provided in the peripheral wall of the fixed cylinder 2 and has a distal end engaged with an engagement groove 5a of the zoom ring 5. In the above configuration, when the zoom ring 5 is rotated, the cam ring 6 is rotated via the pin 8, so that the cam ring 6 is
It moves in the optical axis direction by the action of a and 2a.

On the inner surface of the cam ring 6, a front group lens moving frame 3 is provided.
The cam groove 12 with which the front group pin 10 implanted on the outer surface of the end on the camera body 15 side (the right side in FIG. 1) is slidably engaged.
A cam groove 13 is formed on the outer surface of the end of the rear lens moving frame 4 on the subject side (the left side in FIG. 1) so that the rear group pin 11 slidably engages with the rear group pin 11. The cam grooves 12, 1
The shape of No. 3 will be described later.

A guide hole 7a through which the front group pin 10 penetrates and is slidably engaged with the straight guide cylinder 7,
A guide hole 7b through which the rear group pin 11 penetrates and slidably engages with the rear group pin 11 is formed on a straight line along the optical axis (only 7a is shown in FIG. 1). Straight guide cylinder 7
An engaging portion 7c protruding radially outward is formed on the outer surface of the end portion on the camera body 15 side, and the engaging portion 7c is slidably formed on the inner surface of the peripheral wall of the fixed cylinder 2. An engaging groove 2c to be engaged is engraved along the optical axis, and serves as a guide for movement of the straight guide tube. A convex portion 7d extending in the circumferential direction is formed on the outer surface of the rectilinear guide cylinder 7 at a position slightly forward of the engaging portion 7c toward the subject, and the convex portion 7d slides on the inner surface of the cam ring 6. A circumferentially extending engaging groove 6b that movably engages is formed.

FIG. 4 is a view showing the cam grooves 12 and 13, the guide holes 7a and 7b, the front group pin 10, and the rear group pin 11 in a state where the cam ring 6 and the straight guide cylinder 7 are expanded. A portion between the wide (wide-angle) position and the tele (telephoto) position of the cam groove 12 is formed in an arc shape bulging toward the camera body 15 side,
The portion between the wide position and the retracted position is formed in a shape obliquely moving from the wide position toward the camera body 15 side. On the other hand, a portion between the wide position and the tele position of the cam groove 13 is formed in a shape inclined from the wide position toward the subject, and a portion between the wide position and the retracted position is the cam ring 6.
Are formed in parallel with the rotation direction.

When the pins 10 and 11 are in the wide positions, the lens barrel 1 is in the state shown in FIG. 1 and its appearance is as shown in FIG. The frame 3 slightly projects. From this state, further rotate the zoom ring 5 (rubber ring 9) to rotate the cam ring 6
Is rotated in the direction of arrow A (FIG. 4), the front group pin 1
0, when the rear group pin 11 moves in the cam grooves 12 and 13 toward the retracted position and reaches the retracted position,
Is in the state shown in FIG. 2, and its appearance is in the state shown in FIG. 5 (c). When the zoom ring 5 is turned in the opposite direction from the wide position to rotate the cam ring 6 in the direction of arrow B,
The front group pin 10 and the rear group pin 11 move inside the cam grooves 12 and 13 toward the tele position, and the cam ring 6 and the front group lens moving frame 3 further protrude.
Is in the state shown in FIG. The operation will be described below in detail.

When the zoom ring 5 is turned in the direction of arrow B in FIG. 4 with the pins 10 and 11 in the wide position, the cam ring 6 also moves in the direction of the optical axis while rotating in the direction B, and the straight guide tube 7 is moved. Moves together with the cam ring 6 to the subject side in the optical axis direction without rotating. Therefore, since the cam ring 6 rotates relative to the straight guide cylinder 7, the front group pin 10 and the rear group pin 11 move toward the tele position in the cam grooves 12 and 13. Since the movement of the front group pin 10 is restricted only in the optical axis direction with respect to the rectilinear guide cylinder 7 by the guide hole 7a, the front group pin 10 moves in the optical axis direction with respect to the rectilinear guide cylinder 7. Therefore, the front lens group moving frame 3 and the front lens group L1 also move in the optical axis direction with respect to the straight guide tube 7.

On the other hand, since the movement of the rear group pin 11 is restricted only in the optical axis direction by the guide hole 7b with respect to the straight guide cylinder 7, the rear group pin 11 also moves toward the subject in the optical axis direction with respect to the straight guide cylinder 7. I do. Therefore, the rear lens group moving frame 4 and the rear lens group L2 also move toward the subject in the optical axis direction with respect to the straight guide tube 7. In addition, since the straight guide tube 7 moves toward the subject in the optical axis direction with respect to the fixed tube 2, the front group lens moving frame 3 and the rear group lens moving frame 4 move toward the subject in the optical axis direction with respect to the fixed tube 2. You will travel at different speeds. By moving the front lens group moving frame 3 and the rear lens group moving frame 4 as described above, the overall length of the lens barrel 1 in the optical axis direction becomes longer as the pins 10 and 11 approach the telephoto position. It reaches the longest when it reaches (see FIG. 5A). Also,
By moving the front lens group moving frame 3 and the rear lens group moving frame 4 as described above, the front lens group L1 and the rear lens group L1 are moved.
The relative distance in the optical axis direction between the two changes continuously, and a zooming operation is performed.

Conversely, when the zoom ring 5 is rotated in the direction of arrow A in FIG. 4 with the pins 10 and 11 in the wide position, the cam ring 6 rotates in the same direction A and moves toward the camera body 15 in the optical axis direction. Moving. At this time, the rectilinear guide cylinder 7 does not rotate, but together with the cam ring 6, the optical axis direction camera body 1
Move to side 5. As the cam ring 6 rotates relative to the straight guide cylinder 7, the front group pin 10 and the rear group pin 11
It moves inside the cam grooves 12 and 13 toward the retracted position. Since the movement of the front group pin 10 is restricted only in the optical axis direction by the guide hole 7a with respect to the rectilinear guide cylinder 7, the front group pin 10 moves toward the camera body 15 in the optical axis direction with respect to the rectilinear guide cylinder 7.
Therefore, the front lens group moving frame 3 also moves toward the camera body 15 in the optical axis direction with respect to the straight guide cylinder 7. Further, since the rectilinear guide tube 7 retreats toward the camera body 15 along the optical axis with respect to the fixed tube 2, the front group lens moving frame 3 is fixed to the fixed tube 2.
Is moved toward the camera body 15 in the optical axis direction, and is stored at a position where the front surface is aligned with the fixed cylinder 2.

On the other hand, the rear group pin 11 is restricted by the guide hole 7b and the cam groove 13 from moving backward in the optical axis direction with respect to the rectilinear guide cylinder 7 and does not retreat from the wide position. It does not move relative to it. Therefore, the rear lens group moving frame 4 does not move with respect to the rectilinear guide tube 7. Therefore, the front group lens moving frame 3 and the rear group lens moving frame 4 relatively approach each other.

Front group lens moving frame 3 and rear group lens moving frame 4
1 moves as described above, so that the entire length of the lens barrel 1 in the optical axis direction is the shortest state at the time of shooting (FIG. 1).
(B) Further shortening from the wide state of FIG.
When 0 and the rear group pin 11 reach the retracted position, the retracted state is such that the total length in the optical axis direction is the shortest as shown in FIGS.

The attachment / detachment method of the zoom lens barrel 1 to / from the camera body 15 is a bayonet mount method, which is a standard method of a conventional lens mount mechanism, and is performed after the lens-side mount surface is brought into contact with the body-side mount surface. The mounting is performed by turning the lens barrel 1, and the mounting is performed by performing the reverse operation. A lock mechanism for holding the lens barrel 1 in the mounted state is provided on the lens barrel and the camera body 15.
5 is provided with a lock release button for releasing this lock.

As shown in FIG. 6, the zoom lens barrel 1 rotates the zoom ring in the retracted state from the photographable state (a state between the telephoto position to the wide position) (retracted direction). And the rotation direction when removing the zoom lens barrel from the camera body 15 is the same, and
The rotation direction (projection direction) of the zoom ring when the zoom lens barrel is changed from the collapsed state to the photographable state and the rotation direction when the zoom lens barrel is attached to the camera body 15 are configured to be the same. I have.

In the above configuration, the zoom lens barrel 1
When the camera is removed from the camera body 15, the zoom ring is turned in the direction A as shown in FIG. 7 to change the zoom lens barrel 1 from the photographable state in FIG. 7A to the collapsed state in FIG. When the release button is pressed, there is no need to separately perform the operation of removing the lens barrel 1 from the camera body 15 and retracting the lens barrel 1 as a separate operation.
As shown in FIG. 7 (c). Further, since the user can determine whether or not the photographing is possible based on the magnitude of the rotation resistance of the zoom ring, it is possible to prevent the photographing operation from being performed accidentally in the photographing disabled state.

On the other hand, in the above configuration, the retracting operation area θ
_Since the rotation operation force in ₂ is larger than the rotation operation force for attaching and detaching the zoom lens barrel 1, the operation of attaching the lens barrel 1 to the camera body 15 with only the zoom ring 5 at the time of mounting is required. Even in such a case, only the zoom ring 5 does not rotate, and the entire lens barrel 1 can be rotated. Therefore, the lens barrel 1 does not unnecessarily change from the retracted state to the photographing state, and the mounting can be performed completely. After mounting, the lens barrel 1 itself does not rotate even if the zoom ring 5 is further rotated.
Only the zoom ring 5 rotates, and the lens barrel changes to a shooting state. In this way, the lens barrel can be mounted and the operation for shooting can be performed by rotating the zoom ring in the same direction, so the feeling of use when attaching and detaching is natural, and the chance of taking a photo is missed due to the operation when mounting. There is little fear.

Next, a modification of the above embodiment will be described with reference to FIG.
This will be described with reference to FIG. FIG. 8 is an expanded view of the cam ring 6 and the straight guide cylinder 7 as in FIG.
13, guide holes 7a and 7b, a front group pin 10, and a rear group pin 11 are shown. In this example, the relationship between the tele position and the wide position within the range of the photographable state is reversed from the example of FIG. The cam groove 12 is formed in an arc shape in which a portion between the tele position and the wide position is expanded toward the camera body 15, and a portion between the tele position and the retracted position is skewed from the tele position toward the camera body 15. It is formed in the shape which did. On the other hand, the cam groove 13 has the telephoto position closest to the subject, and the portion between the retracted position and the wide position is formed in a shape obliquely inclined from the telephoto position toward the camera body 15.

Also in this example, as in the case shown in FIGS. 1 to 7, the rotation direction of the zoom ring when changing from the photographable state (the state between the tele position to the wide position) to the collapsed state, and the camera The rotation direction of the zoom ring when removing the zoom lens barrel from the body 15 is the same, and the rotation direction of the zoom ring when the zoom lens barrel is changed from the retracted state to the photographable state, and the camera body 15
The rotation direction of the zoom ring when the zoom lens barrel is attached to the camera is configured to be the same.

In the above configuration, the cam ring 6 is moved to the position A in the figure with the lens barrel attached to the camera body 15.
When turned in the direction, the front group pin 10 and the rear group pin 11 move toward the wide position to the tele position to the retracted position, respectively.
The lens barrel changes from a photographable state to a collapsed state. Therefore, if the lock of the bayonet mount mechanism is released after the lens barrel is in the collapsed state, the collapse operation after removing the lens barrel is unnecessary. On the other hand, when the cam ring 6 is rotated in the direction B while the lens-side mounting surface is aligned with the body-side mounting surface, the front group pin 10
The rear group pin 11 moves from the retracted position to the telephoto position to the wide position, and the lens barrel changes from the retracted state to the photographable state. Therefore, the lens barrel can be brought into a photographable state without any special operation after the lens barrel is mounted.

Next, a modification shown in FIG. 9 will be described. This example, as a resistance means for increasing the zoom ring (control ring) zoom operation region shown in FIG. 3 the operation force of 5 (main operational area) theta retracted manipulating area theta ₂ than _1, the click mechanism 16 This is an example used. The click mechanism 16
Leaf spring 1 fixed to the inner surface of zoom ring 5 with screws 17
8, a V-shaped groove 19 formed on the outer surface of the fixed cylinder 2,
A steel ball 20 pressed against the outer surface of the fixed cylinder 2 by a leaf spring 18 so as to be pressed against the outer surface of the fixed cylinder 2.
₂ , the steel ball 20 is configured to fit into the groove 19.

The steel ball 20 is supported so as to move in the circumferential direction together with the leaf spring 18 when the zoom ring 5 is rotated, and is detached from the groove 19 by turning the zoom ring 5 from the state shown in FIG. It has become. And
The depth of the concave portion 19 and the leaf spring are set so that the rotating operation force of the zoom ring 5 necessary for removing the steel ball 20 from the groove 19 is larger than the rotating operation force of attaching and detaching the zoom lens barrel to and from the camera body. Eighteen strengths are defined.

Even with this configuration, the zoom ring alone does not unnecessarily rotate when the lens barrel is attached to or detached from the camera body, as in the example of FIG. An excellent effect regarding the detachability can be obtained.

It is needless to say that the present invention is also applicable to a single focus lens barrel having a retracted state.

[Brief description of the drawings]

FIG. 1 is a central sectional view along an optical axis of a retractable interchangeable zoom lens barrel according to an embodiment of the present invention, showing a wide (wide-angle) state.

FIG. 2 is a central sectional view showing a collapsed state of the zoom lens barrel in FIG. 1;

FIG. 3 is a cross-sectional view of a fixed cylinder and a zoom ring at right angles to the axis.

FIG. 4 is an exploded view of a cam ring and a straight guide cylinder, showing each cam groove, each guide hole, a front group pin, and a rear group pin.

FIG. 5A, FIG. 5B, and FIG.
FIG. 4 is a diagram illustrating the appearance of a lens barrel during telephoto, wide, and retracted.

FIG. 6 is a perspective view showing a rotation direction when the lens barrel is operated.

FIG. 7 is a diagram illustrating an operation of removing a lens barrel.

FIG. 8 is a development view of a cam ring and a straight guide cylinder, showing a modified example of a cam groove and a guide hole.

FIG. 9 is an enlarged sectional view of a main part showing a modification of the resistance means.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 retractable interchangeable zoom lens barrel 2 fixed barrel 2 d first contact surface (resistance means) 3 front group lens movement frame 4 rear group lens movement frame 5 zoom ring (operation ring) 5 b second contact surface (resistance means) 6 cam Ring 7 Straight guide cylinder 7a, 7b Guide hole 8 Pin 9 Rubber ring 10 Front group pin 11 Rear group pin 12 Cam groove 13 Cam groove 14 Throttle mechanism 15 Camera body 16 Click mechanism (resistance means) 17 Screw 18 Leaf spring 19 Groove 20 wrecking ball

Claims (2)

[Claims] 1. A structure in which the operation ring (5) is turned so that the entire length in the optical axis direction can be in a collapsed state shorter than the shortest state at the time of photographing, and is detachable from the camera body (15). Resistance means (2d, 5b) for increasing the rotational resistance of the operating ring (5) in the retractable operation area (θ ₂ ) than in the main operation area (θ ₁ ). ) (16), and that the rotational operation force in the collapsible operation area (θ ₂ ) is set to be larger than the rotational operation force for attaching and detaching the lens barrel (1) to and from the camera body (15). Features a retractable interchangeable lens barrel. And a first contact surface (2d) formed on an outer surface of a fixed barrel (2) of the lens barrel (1), and a main operating area (θ ₁ ). A second contact surface formed on the inner surface of the operation ring (5) so as to contact only with the first contact surface (2d).
The retractable interchangeable lens barrel according to claim 1, wherein the lens barrel comprises: (5b).