JP2007199557A - Lens barrel, interchangeable lens and camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel having constitution equipped with a second barrel member provided on an inner periphery side of a first barrel member, and a member to be supported provided on the inner periphery side of the second barrel member and supported on the outer circumferential side of the second barrel member, wherein the rotatable angle of the second barrel member is large and the member to be supported is stably supported, and to provide an interchangeable lens and a camera system. <P>SOLUTION: A machine screw 21 passing through a first through-hole 2c provided on a cam barrel 2 and supporting a diaphragm unit 20, and a diaphragm engaging plate 22 passing through a second through-hole 2d provided on the cam barrel 2 and supporting the diaphragm unit 20 are provided. The second through-hole 2d is provided at a different position in the optical axis direction of a photographic optical system from the first through-hole 2c. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens barrel, an interchangeable lens, and a camera system in which a rotatable barrel is provided inside a fixed barrel.

In an autofocus operation, a lens barrel, an interchangeable lens, and a camera system that use an ultrasonic motor as an actuator for driving a lens group are widely used. As an ultrasonic motor used for such a lens barrel or the like, an annular ultrasonic motor formed in an annular shape around a lens group is often used. When such an ultrasonic motor is arranged in the lens barrel, the use efficiency of the space can often be increased by arranging the ultrasonic motor around a fixed cylinder that is not driven by the focusing operation.
Patent Document 1 shows an example in which an ultrasonic motor is arranged around a fixed cylinder. In the lens barrel described in Patent Document 1, since the ultrasonic motor is arranged on the outer peripheral side of the fixed cylinder, the cam cylinder is arranged on the inner peripheral side of the fixed cylinder, and the cam is formed on the fixed cylinder. The lens group is engaged with and supported by a groove, a linear guide groove, and the like and a cam groove formed in the cam cylinder.
The cam cylinder described in Patent Document 1 has a rotation angle smaller than 120 degrees during zooming, and can be formed without overlapping even if three cam grooves for zooming are arranged in the circumferential direction. The focusing cam is formed over an angle range of 120 degrees or more. However, the three cam grooves can be broken by arranging the portions extending in the optical axis direction so as to overlap with each other. It is formed without.

By the way, an optical system in which a member (for example, a diaphragm unit or a lens group, hereinafter referred to as a non-movable member) whose position in the optical axis direction does not move with the rotation of the cam cylinder is also conceivable.
However, when a lens barrel having such an optical system is configured such that a cam barrel is disposed on the inner diameter side of the fixed barrel, as in Patent Document 1, it is intended to support the non-movable member at three locations. The cam cylinder has a problem that the cam cylinder cannot be rotated by 120 degrees or more because three grooves for escaping the support portion are arranged in the circumferential direction.
On the other hand, when the cam cylinder is rotated by 120 degrees or more, there is a problem that three support portions for supporting the non-movable member cannot be provided.

Even a non-movable member that does not move is preferably supported at three locations in order to stably support its position and posture. If the support is made at two places, there is a possibility that the non-movable member may tilt with respect to the optical axis.
On the other hand, for example, in a micro lens barrel that can perform close-up photography and magnified photography, the focus operation ring is rotated as much as possible so that fine focus adjustment can be performed. There is a demand to reduce the amount of extension of the focus lens group with respect to the rotation angle. Therefore, in such a lens barrel, a configuration in which the cam barrel is rotated by 120 degrees or more is desirable.
Japanese Patent Laid-Open No. 10-39188

  The subject of this invention is the 2nd cylinder member provided in the inner peripheral side rather than the 1st cylinder member, and the outer peripheral side rather than the 2nd cylinder member provided in the inner peripheral side rather than the 2nd cylinder member. By providing a lens barrel, an interchangeable lens, and a camera system in which the second cylinder member has a large rotatable angle and can stably support the supported member in the configuration including the supported member to be supported. is there.

In order to solve the above-mentioned problem, the invention of claim 1 is provided with an imaging optical system, a first cylindrical member provided around the imaging optical system, and an inner peripheral side of the first cylindrical member. The second cylindrical member, a supported member provided on the inner peripheral side of the second cylindrical member and supported on the outer peripheral side of the second cylindrical member, and provided on the second cylindrical member A first support portion that supports the supported member through the formed first through hole, and a second through hole provided in the second cylindrical member to support the supported member. A lens having a second support portion, wherein the second through hole is provided at a position different from the first through hole in the optical axis direction of the photographing optical system. It is a lens barrel.
According to a second aspect of the present invention, in the lens barrel according to the first aspect, the first through hole is provided at a plurality of positions in the circumferential direction, and the first support portion is a plurality of positions in the circumferential direction. The lens barrel is characterized in that it supports the supported member.
A third aspect of the present invention is the lens barrel according to the first or second aspect, wherein the supported member is supported by the first cylindrical member.
According to a fourth aspect of the present invention, in the lens barrel according to any one of the first to third aspects, the second support portion is located at a position different from the first support portion in the circumferential direction. A lens barrel is provided.
According to a fifth aspect of the present invention, in the lens barrel according to any one of the first to fourth aspects, the second support portion is formed of a plate-shaped member. It is a lens barrel.
According to a sixth aspect of the present invention, in the lens barrel according to any one of the first to fifth aspects, the optical axis of the second cylindrical member is provided on the incident side with respect to the supported member. An incident-side movable portion that is driven in a direction along the optical axis by a rotational movement around, and provided on an emission side from the supported member, and the rotational movement of the second cylindrical member around the optical axis The lens barrel includes an exit-side movable unit that is driven in a direction along the optical axis.
According to a seventh aspect of the present invention, in the lens barrel according to the sixth aspect, when the incident side movable member and the emission side movable member are driven, the angle at which the second cylindrical member can be rotated is 120 degrees. This is the lens barrel characterized by the above.
The invention according to claim 8 is the lens barrel according to claim 6 or 7, wherein the incident side movable portion and the exit side movable portion are moved in a direction along the optical axis to move the photographing optical. The lens barrel is a focus lens group in which the focal position of the system moves.
According to a ninth aspect of the present invention, in the lens barrel according to any one of the first to eighth aspects, the second cylindrical member is rotationally driven closer to the outer peripheral side than the first cylindrical member. The lens barrel is provided with a driving unit that performs the above operation.
A tenth aspect of the present invention is the lens barrel according to any one of the first to ninth aspects, wherein the supported member is a diaphragm unit that adjusts the amount of light passing through the photographing optical system. This is a lens barrel characterized by the following.
An eleventh aspect of the present invention is the lens barrel according to any one of the first to tenth aspects, further comprising a mount portion that engages with a camera that captures an image by the photographing optical system. It is an interchangeable lens.
The invention of claim 12 is a camera system including the lens barrel according to any one of claims 1 to 10 or the interchangeable lens according to claim 11.

  According to the present invention, the rotatable angle of the second cylindrical member can be increased, and the supported member can be stably supported.

  The first through hole through which the first support part and the second support part penetrate and the second purpose are provided for the purpose of stably supporting the supported member with a large rotatable angle of the second cylindrical member. This was realized by arranging the through holes at different positions in the optical axis direction of the photographing optical system.

FIG. 1 is a cross-sectional view showing the lens barrel of this embodiment. FIG. 1 shows a state in which the focus is adjusted to the infinity position.
The lens barrel of this embodiment is an interchangeable lens of a micro (macro) lens barrel that includes a single-focus imaging optical system including lens groups L1, L2, L3, and L4 and can perform close-up photography and enlargement photography. .
The fixed cylinder 1 is a first cylinder member provided around the photographing optical system without moving with respect to the mount portion 13 even when the cam cylinder 2 described later is rotated.
An ultrasonic motor 4 is provided on the outer periphery of the fixed cylinder 1 as a drive unit that rotationally drives a cam cylinder 2 described later. A focus drive lever 3 that transmits the rotational drive force of the ultrasonic motor 4 is engaged with the output portion 4 a of the ultrasonic motor 4. A focus ring interlocking member 4c is attached to the stator 4b side of the ultrasonic motor 4. A roller 8 is attached to the focus ring interlocking member 4c.

A focus operation ring 10 is rotatably provided on the outermost periphery of the lens barrel. On the inner peripheral side of the focus operation ring 10, an MF interlocking ring 12 is rotatably provided independently of the focus operation ring 10. A wave washer 11 is charged between the focus operation ring 10 and the MF interlocking ring 12. The wave washer 11, the MF interlocking ring 12, and the roller 8 are disposed between the focus operation ring 10 and the lens barrel outer frame 9, and the urging force of the wave washer 11 is transmitted to the MF interlocking ring 12 and the roller 8.
When the focus operation ring 10 rotates, the MF interlocking ring 12 rotates by the same rotation angle as the focus operation ring 10 due to the frictional force generated by the urging force of the wave washer 11. At this time, the roller 8 rotates together with the focus ring interlocking member 4c while rotating. Since the roller 8 is interposed, the rotation angle of the focus ring interlocking member 4 c is half of the rotation angle of the focus operation ring 10. Accordingly, when the focus operation ring 10 rotates, the entire ultrasonic motor 4 rotates by a rotation angle that is half the rotation angle of the focus operation ring 10, and this rotation is transmitted to the focus drive lever 3.

The cam cylinder 2 is a second cylinder member that is rotatably provided on the inner peripheral side of the fixed cylinder 1. The cam cylinder 2 is provided with three cam grooves 2a and 2b (see FIG. 3).
Cam followers L2a (two pairs of cam followers L2a formed at one place) are engaged with the cam groove 2a. The cam follower L <b> 2 a is engaged with a rectilinear groove 1 a provided in the fixed cylinder 1. Therefore, the lens group L2 is an incident side movable portion that moves along the optical axis when the cam cylinder 2 rotates.

A cam follower L3a provided in the lens unit L3 is engaged with the cam groove 2b. The cam follower L3a is engaged with a rectilinear groove 1b provided in the fixed cylinder 1. Therefore, the lens unit L3 is an exit side movable portion that moves along the optical axis when the cam cylinder 2 rotates.
The photographic optical system of the present embodiment has a configuration in which the lens group L2 and the lens group L3 are used as a focus lens group, and focus adjustment is performed by moving the lens group L2 and the lens group L3 in the optical axis direction.
The aperture unit 20 is a supported member having an aperture blade 20a that adjusts the amount of light passing through the photographing optical system, and is provided at a position sandwiched between the lens group L2 and the lens group L3. The support structure of the aperture unit 20 will be described later.

FIG. 2 is a diagram illustrating a configuration for transmitting a driving force to the cam cylinder 2. 2A is a cross-sectional view cut along a plane along the optical axis, and FIG. 2B is a cross-sectional view cut along a plane perpendicular to the optical axis in the vicinity of the screw 7, FIG. ) Is a view of the focus drive lever 3 as viewed from the direction of arrow A. FIG.
FIG. 3 is a view of the fixed cylinder 1 and the focus drive ring 5 as seen from the outside.
A focus drive ring 5 is disposed on the outer periphery of the fixed cylinder 1. The focus drive ring 5 is fixed so as to be integrated with the cam cylinder 2 by a screw 7 that penetrates the circumferential groove 1 c of the fixed cylinder 1. Two screws 7 are provided at substantially opposing positions (positions separated by approximately 180 degrees in the circumferential direction). A bearing 6 is provided between the screw 7 and the circumferential groove 1 c of the fixed cylinder 1. Therefore, the focus drive ring 5 can rotate integrally with the cam cylinder 2 on the outer periphery of the fixed cylinder 1.
A focus drive lever 3 is fixed to the focus drive ring 5. The position at which the focus drive lever 3 is fixed is a position that is approximately 90 degrees away from the screw 7 in the circumferential direction.

With the above configuration, the rotational driving force of the focus operation ring 10 at the time of manual focusing or the rotational driving force of the ultrasonic motor 4 at the time of autofocusing is applied to the cam cylinder 2 provided on the inner peripheral side of the fixed cylinder 1. Thus, the cam cylinder 2 is rotated and transmitted from the outside of the fixed cylinder 1.
FIG. 4 is a cross-sectional view showing a state in which the lens barrel of the present embodiment is focused on the closest position.
By performing the focusing operation described above, the lens unit L2 and the lens unit L3 can move from the infinity position to the closest position shown in FIG.

Here, as can be seen from FIG. 1 and FIG. 4, the aperture unit 20 does not move relative to the fixed cylinder 1 depending on the focusing operation. A support structure for the aperture unit 20 will be described.
FIG. 5 is a view for explaining the support structure of the aperture unit 20. Fig.5 (a) is sectional drawing cut | disconnected by the surface along an optical axis, FIG.5 (b) is the figure seen from the output side.
FIG. 6 is a view of the fixed cylinder 1 and the cam cylinder 2 in a state where the focus is adjusted to an infinite position, as viewed from the outside.
FIG. 7 is a view of the fixed cylinder 1 and the cam cylinder 2 in a state in which the focus is adjusted to the closest position, as viewed from the outside.
The aperture unit 20 is fixed to the fixed cylinder 1 by a screw 21 that is a first support portion. The screws 21 are provided at two locations at positions that are substantially opposed (positions that are approximately 180 degrees apart in the circumferential direction). In addition, the cam cylinder 2 is provided with two first through holes 2 c that are open so that the screws 21 do not come into contact with the cam cylinders 2.

  As described above, the lens barrel of the present embodiment is a microlens barrel. In the microlens barrel, it is desirable to increase the rotation angle of the focus operation ring as much as possible to reduce the amount of extension of the focus lens group with respect to the rotation angle of the focus operation ring so that fine focus adjustment can be performed. Therefore, the cam cylinder 2 of the present embodiment is configured to rotate by 120 degrees or more by the focus adjustment operation from the infinite position to the closest position so that the rotation angle can be increased as much as possible.

The cam grooves 2a and 2b formed in the cam cylinder 2 are cams for moving the position of the lens group, and the cam cylinder 2 is arranged by overlapping the portions extending in the optical axis direction in the optical axis direction. Even in the case of the present embodiment that rotates 120 degrees or more, the three cam grooves can be formed without sacrificing the strength of the cam barrel 2. However, the first through-hole 2c is a groove that is opened so that the screw 21 that fixes the diaphragm unit 20 that does not move in the optical axis direction with respect to the fixed cylinder 1 does not hit even when the cam cylinder 2 rotates. , Formed in a straight line (in a developed view) in the circumferential direction. Therefore, when the cam cylinder 2 rotates 120 degrees or more, the first through hole 2c can be provided only in two places. If there are only two screws 21 for fixing the diaphragm unit 20, the diaphragm unit 20 may be inclined with respect to the optical axis with the screw 21 as a fulcrum.
A lens group L2 and a lens group L3 are arranged on the entrance side and the exit side of the aperture unit, respectively. The lens group L2 and the lens group L3 move along the optical axis direction by the rotation of the cam cylinder 2. Therefore, the diaphragm unit 20 cannot be supported from the incident side or the emission side of the diaphragm unit 20 without penetrating the cam cylinder 2.

In order to prevent the throttle unit 20 from tilting, in the present embodiment, a diaphragm engaging plate 22 is fixed to the outer periphery of the fixed cylinder 1 with a screw 23 as a second support portion. The aperture engaging plate 22 is formed by bending a plate-like member approximately 90 degrees, and the tip thereof is inserted into an engaging hole 20 a provided in the aperture unit 20. The fixed cylinder 1 has a through-hole 1d that is opened so that the diaphragm engaging plate 22 does not hit, and the cam cylinder 2 has a second through hole that is opened so that the diaphragm engaging plate 22 does not hit. The hole 2d is provided at a position different from the first through hole 2c in the optical axis direction of the photographing optical system. Specifically, the position where the second through hole 2d is provided is a position where the positional relationship with the first through hole 2c is shifted by approximately 90 degrees in the circumferential direction.
Therefore, even if the cam cylinder 2 rotates 120 degrees or more, even if the second through hole 2d is provided in addition to the two first through holes 2c, the strength of the cam cylinder 2 is not reduced. .
As described above, the diaphragm engaging plate 22 prevents the diaphragm unit 20 from tilting by penetrating through the second through hole 2d and engaging with the diaphragm unit 20.

  According to this embodiment, it is possible to stably support the aperture unit 20 while securing a rotatable angle of the cam cylinder 2 as large as 120 degrees or more.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the equivalent scope of the present invention.
(1) In the present embodiment, the example in which the aperture unit 20 is a supported member has been described. However, the present invention is not limited thereto, and other members such as a lens shutter unit and a lens group may be used as the supported member.

(2) In the present embodiment, the example of the interchangeable lens has been described. However, the present invention is not limited to this. For example, a camera system in which the lens cannot be replaced may be used.

(3) In the present embodiment, the example in which the rotatable angle of the cam cylinder 2 is 120 degrees or more has been described. However, the present invention is not limited to this, and for example, the rotatable angle of the cam cylinder 2 satisfies 120 degrees. There may be no lens barrel.

It is sectional drawing which shows the lens barrel of a present Example. 4 is a diagram illustrating a configuration for transmitting a driving force to a cam cylinder 2. FIG. It is the figure which unfolded the fixed cylinder 1 and the focus drive ring 5, and was seen from the outer side. It is sectional drawing which shows the state by which the lens-barrel of the present Example was focus-adjusted to the nearest position. FIG. 6 is a diagram for explaining a support structure of the aperture unit 20. It is the figure which unfolded the fixed cylinder 1 and the cam cylinder 2 of the state adjusted to the infinite position, and was seen from the outer side. It is the figure which unfolded the fixed cylinder 1 and the cam cylinder 2 in the state in which the focus was adjusted to the close position, and was seen from the outer side.

Explanation of symbols

1: fixed cylinder, 2: cam cylinder, 2c: first through hole, 2d: second through hole, 21: screw, 22: diaphragm engagement plate, 20: diaphragm unit

Claims (12)

Photographic optics,
A first cylindrical member provided around the photographing optical system;
A second cylinder member provided on the inner peripheral side of the first cylinder member;
A supported member that is provided on the inner peripheral side of the second cylindrical member and supported on the outer peripheral side of the second cylindrical member;
A first support portion that supports the supported member through a first through hole provided in the second cylindrical member;
A second support part that supports the supported member through a second through hole provided in the second cylindrical member;
The lens barrel, wherein the second through-hole is provided at a position different from the first through-hole in the optical axis direction of the photographing optical system. The lens barrel according to claim 1,
The first through holes are provided at a plurality of positions in the circumferential direction,
The lens barrel according to claim 1, wherein the first support portion supports the supported member at a plurality of positions in the circumferential direction. In the lens barrel according to claim 1 or 2,
The lens barrel, wherein the supported member is supported by the first tube member. The lens barrel according to any one of claims 1 to 3, wherein
The lens barrel, wherein the second support part is provided at a position different from the first support part in the circumferential direction. In the lens barrel according to any one of claims 1 to 4,
The lens barrel, wherein the second support portion is formed of a plate-like member. In the lens barrel according to any one of claims 1 to 5,
An incident-side movable portion that is provided closer to the incident side than the supported member and is driven in a direction along the optical axis by rotational movement of the second cylindrical member around the optical axis;
A lens provided on the exit side of the supported member and driven in the direction along the optical axis by the rotational movement of the second cylindrical member around the optical axis. A lens barrel. The lens barrel according to claim 6, wherein
The lens barrel characterized in that an angle at which the second cylindrical member can be rotated when the incident side movable member and the emission side movable member are driven is 120 degrees or more. In the lens barrel according to claim 6 or 7,
The lens barrel according to claim 1, wherein the incident side movable unit and the emission side movable unit are a focus lens group in which a focal position of the photographing optical system is moved by moving in a direction along the optical axis. In the lens barrel according to any one of claims 1 to 8,
A lens barrel characterized in that a drive unit for rotationally driving the second cylindrical member is provided on the outer peripheral side of the first cylindrical member. In the lens barrel according to any one of claims 1 to 9,
The lens barrel according to claim 1, wherein the supported member is a diaphragm unit that adjusts an amount of light passing through the photographing optical system. The lens barrel according to any one of claims 1 to 10,
An interchangeable lens comprising: a mount unit that engages with a camera that captures an image by the imaging optical system. A camera system comprising the lens barrel according to claim 1 or the interchangeable lens according to claim 11.

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