JP6364736B2 - Lens barrel and optical equipment - Google Patents

Description

  The present invention relates to a lens barrel and an optical apparatus.

  There is a lens barrel provided with an aperture operation unit for opening and closing an aperture member by an operation from a camera body. Conventionally, the drawing operation unit is manufactured by punching a metal flat plate and bending it (see Patent Document 1).

JP 2005-266476 A

  However, since the conventional diaphragm operating unit is manufactured by punching a metal flat plate, there is no degree of freedom in shape, and an additional member is required for measures against light leakage and ghost, which increases costs. .

  An object of the present invention is to provide a lens barrel and an optical apparatus having an aperture operation unit that can be designed more freely.

The present invention has an annular shape centered on the optical axis, and is made of a resin-made annular portion that is rotatable, and is integrated with the annular portion so as to extend from the annular portion to the subject side along the optical axis direction. A molded first extending portion made of resin, a second extending portion made of resin integrally formed with the annular portion so as to extend from the annular portion toward the image side along the optical axis direction, and a diaphragm A throttle part that has blades, engages with the first extension part, and opens and closes the diaphragm blades by rotation of the first extension part, and includes the first extension part and the second extension part. The extending portion relates to a lens barrel characterized by being formed continuously along the optical axis direction.
The present invention also relates to an optical apparatus including the lens barrel.

  According to the present invention, it is possible to provide a lens barrel and an optical apparatus having a diaphragm operation unit that can be designed more freely.

It is sectional drawing which shows the camera in this embodiment typically. It is a conceptual sectional view at the telephoto end of the lens barrel. It is a conceptual sectional view at the wide-angle end of the lens barrel. The diaphragm operating member is shown, (a) is a perspective view seen from the back side (Z minus side), (b) is a sectional view taken along the line BB of (a), and (c) is a comparative example corresponding to (b). FIG. It is a perspective view of the aperture operation member as a comparative example. It is a conceptual sectional view in the wide angle end of a lens barrel as a comparative example.

  Embodiments of the present invention will be described below with reference to the drawings. Each figure shown below is provided with an XYZ orthogonal coordinate system for ease of explanation and understanding. In this coordinate system, when the photographer shoots a horizontally long image with the optical axis A horizontal, the direction toward the left as viewed from the photographer at the position of the camera on which the lens barrel 10 is mounted (hereinafter referred to as a normal position). Is the X plus direction, the upward direction at the positive position is the Y plus direction, and the direction toward the subject at the positive position is the Z plus direction. The Z plus side is also referred to as the front side, and the Z minus side is also referred to as the back side.

FIG. 1 is a cross-sectional view schematically showing a camera 1 in the present embodiment. FIG. 2 is a conceptual cross-sectional view of the lens barrel 10 at the telephoto end. FIG. 3 is a conceptual cross-sectional view of the lens barrel 10 at the wide angle end.
The camera 1 includes a camera body 100 and a lens barrel 10 that can be attached to and detached from the camera body 100. In the present embodiment, the camera body 100 having the interchangeable lens barrel 10 will be described. However, the present invention is not limited to this, and a camera having a lens barrel integrated with the camera body may be used.

  The camera body 100 is a so-called single-lens reflex digital camera body, and detailed description is omitted, but a quick return mirror 101, a finder optical system 102, and an image sensor 103 that converts an optical image of a subject into an electrical signal. And a camera side interlocking unit 104 for setting the aperture, and a camera side mount 105 to which the lens barrel 10 is coupled.

  The quick return mirror 101 bends the optical path of the subject image collected by the lens barrel 10 toward the viewfinder optical system 102. In response to the release operation, the quick return mirror 101 moves to a retracted position (indicated by a two-dot chain line in FIG. 1) that does not prevent the subject light from entering the image sensor 103.

The imaging element 103 is a photoelectric conversion element such as a CCD or a CMOS that converts an object image formed by the lens barrel 100 into an electric signal.
The camera-side interlocking unit 104 narrows down a diaphragm operation member 40 of the diaphragm mechanism 20 in the lens barrel 10 to be described later at the time of shooting and a narrowing operation by a user.
The camera side mount 105 is engaged with a bayonet mount 15 </ b> A of a mount cylinder portion 15 of the lens barrel 10 to be described later, whereby the lens barrel 10 is attached to the camera body 100.

When a shutter button (not shown) included in the camera body 100 is pressed (release operation), the camera 1 moves the quick return mirror 101 to the retracted position, and the image sensor 103 converts subject image light into an electrical signal. The imaging data is recorded (that is, photographed) in a recording unit (not shown).
At the time of this photographing, the camera side interlocking unit 104 performs a diaphragm operation of a diaphragm operation member 40 of the diaphragm mechanism 20 in the lens barrel 10 described later.

Next, the lens barrel 10 will be described.
The lens barrel 10 is a so-called zoom lens capable of variably adjusting the focal length by changing the relative position of the built-in optical system (lens groups L1 to L4).
The lens barrel 10 is disposed between the outer fixed tube 11, the inner fixed tube 12, the cam tube 13 disposed on the inner peripheral side of the outer fixed tube 11, and the inner fixed tube 12 and the cam tube 13. The straight traveling group 14 and a plurality of lens groups (L1 to L4) constituting the imaging optical system are provided.

  In addition, the lens barrel 10 includes a diaphragm mechanism 20. In the present embodiment, the second lens group L2 is a shake correction lens group including the image stabilization unit VU. A diaphragm blade unit 30 in the diaphragm mechanism 20 described later is integrally mounted on the front side (Z-axis direction plus side) of the third lens frame F3 of the third lens unit L3.

The outer fixed cylinder 11 is a cylindrical member that forms the outer surface of the lens barrel 10, and is fixed to the inner fixed cylinder 12 and the mount cylinder portion 15 at the subject side end.
The mount tube portion 15 is provided with a bayonet mount 15A.
The bayonet mount 15A includes an engaging claw that engages with the camera-side mount 105 of the camera body 100 on the outer periphery of the short cylindrical ring portion.
On the front surface side (Z-axis plus side) of the mount cylinder portion 15, an annular portion 41 of a diaphragm operation member 40 in the diaphragm mechanism 20 described later is rotatably mounted by a pressing plate 17.

  The cam cylinder 13 has a rubber cylinder 13A integrally formed on the outer periphery thereof exposed to the outer surface, and can be rotated by a user. Although the detailed description is omitted, the cam cylinder 13 is linked to the rectilinear group 14, the second lens group L2, the third lens group L3, and the fourth lens group L4 through a known linkage mechanism such as a cam groove and a follower pin. These are moved by rotation.

The rectilinear group 14 is disposed between the cam cylinder 13 and the inner fixed cylinder 12. The rectilinear group 14 holds the first lens group L1 through the focus ring 16 at the tip. The rectilinear group 14 is moved and operated in the direction of the optical axis OA by the rotation of the cam cylinder 13.
The first lens unit L1 is moved in the optical axis OA direction (Z-axis direction) by the movement of the rectilinear group 14 by the rotation of the cam cylinder 13, and is also moved in the optical axis OA direction (Z-axis) with respect to the rectilinear group 14 by the focus ring 16. Direction).

  In the lens barrel 10 having the above-described configuration, the rectilinear group 14 (first lens group L1), the second lens group L2, the third lens group L3, and the fourth lens group are obtained by rotating the cam cylinder 13 via the rubber cylinder 13A. L4 moves in a predetermined positional relationship, and the focal length of the entire imaging optical system continuously changes (zooming). The relative positions of the lens groups L1 to L4 change between the telephoto end shown in FIG. 2 and the wide-angle end shown in FIG. Although explanation is omitted, the first lens unit L1 and the second lens unit L2 are moved to perform focus adjustment (focusing).

Next, referring to FIGS. 4 to 6 in addition to FIGS. 1, 2, and 3 described above, the diaphragm mechanism 20 having a characteristic configuration in the present embodiment will be described.
4A and 4B show the diaphragm operating member 40, where FIG. 4A is a perspective view seen from the back side (Z minus side), FIG. 4B is a cross-sectional view taken along line BB in FIG. 4A, and FIG. It is a figure which shows the corresponding comparative example. FIG. 5 is a perspective view of a diaphragm operation member 40 ′ as a comparative example. FIG. 6 is a conceptual cross-sectional view at the wide-angle end of a lens barrel 10 ′ as a comparative example.

  The aperture mechanism 20 includes an aperture blade unit 30 and an aperture operation member 40 that operates the aperture blade unit 30. The aperture mechanism 20 is operated by the camera-side interlocking unit of the camera body 100 when the camera body 100 (not shown) to which the lens barrel 10 is attached is used for the aperture operation and when shooting.

The aperture blade unit 30 includes an aperture portion 31 mounted on the front surface (Z-axis plus side surface) of the third lens frame F3 that holds the third lens unit L3, and an aperture operation arm 32 that operates the aperture blades. Yes.
Although the detailed description is omitted, the diaphragm unit 31 includes a plurality of diaphragm blades that form diaphragm openings inside the diaphragm case. The aperture blade is opened and closed by an aperture cam plate so that the aperture diameter of the aperture changes, and is biased to the open side by a biasing means such as a spring.

The aperture operation arm 32 is a thin plate having a rectangular cross section, and extends to the back side (Z-axis minus side). An engagement portion 33 having a U-shaped cross section is formed at the distal end of the diaphragm operation arm 32 to be engaged on the front side in the operation direction by the operation lever 42.
The diaphragm operation arm 32 is operated in a direction to squeeze the diaphragm blades against the urging force of the urging means by an operation lever 42 of the diaphragm operation member 40 described later. In this embodiment, the operation direction of the aperture operation arm 32 by the operation lever 42 is counterclockwise when viewed from the back side (Z-axis minus side).

As shown in FIG. 4A, the aperture operation member 40 is integrally provided with an operation lever 42 for operating the aperture blade unit 30 in an annular portion 41 having an annular shape.
The aperture operation member 40 in the present embodiment is formed by injection molding using a mold with resin. For example, a sliding grade is used as the resin material, and a fitting surface is provided to reduce the contact area.

  The annular portion 41 is formed in an annular shape by a thin plate. A lens-side interlocking unit 43 (shown in FIG. 1) that is operated by the camera-side interlocking unit 104 of the camera body 100 protrudes from the Z-axis minus side surface.

Moreover, according to this embodiment, since the annular part 41 is manufactured with resin, there exists a freedom degree of a shape compared with the case where it manufactures with metal materials, such as a press. As shown in FIG. 4B, the inner peripheral end surface 41B of the annular portion 41 is tapered at a predetermined angle in a direction that expands toward the front side (Z-axis plus side). Is formed. Thereby, as shown by a broken line and a two-dot chain line in FIG. 4B, the light reflected by the inner peripheral end face 41B does not enter the third lens unit L3.
As a result, it is possible to suppress the occurrence of flare due to the reflected light on the inner peripheral end face 41B. Further, the antireflection treatment is not necessary. If the inner peripheral end face 41B ′ of the annular portion 41 ′ is parallel to the optical axis OA as in the comparative example shown in FIG. 4C, the reflected light may enter the third lens unit L3. The taper direction of the inner peripheral end face 41B may be reversed.

The operation lever 42 is a thin plate with a rectangular cross section that engages with the engagement portion 33 of the aperture operation arm 32 in the aperture blade unit 30, and is provided integrally with the inner periphery of the annular portion 41.
And according to this embodiment, since it is resin and is easy to shape | mold, the operation lever 42 is light-transmitted to both the front side (Z-axis plus side) and back side (Z-axis minus side) of the annular part 41. It extends in parallel with the axis OA (Z axis). The length of the operation lever 42 in the optical axis OA direction (Z-axis direction) and the position with respect to the annular portion 41 in the direction will be described in detail later.

Further, since the operation lever 42 is made of resin and can be easily molded, a light shielding structure (light shielding line) 43 that prevents stray light due to reflection is formed on the inner peripheral surface of the operation lever 42. The light shielding structure 44 is formed in a triangular wave shape in which concave portions and convex portions extending in a direction orthogonal to the optical axis OA are alternately arranged and the traveling direction is the optical axis OA direction (Z-axis direction).
As described above, since the light shielding structure 44 is formed on the inner peripheral surface of the operation lever 42, a separate light shielding sheet and an operation of attaching the light shielding sheet become unnecessary, and the cost can be reduced by reducing the material cost and the number of man-hours. It becomes possible.
In the diaphragm operating member 40 as described above, the shape in which the operation lever 42 protrudes on both sides of the annular portion 41 and the shape of the light shielding structure 44 can be easily formed by injection molding with resin.

The diaphragm operating member 40 is provided such that the annular portion 41 is held on the front surface side (Z-axis plus side) of the mount cylinder portion 15 so as not to fall off by the pressing plate 17 and is rotatable about the optical axis OA. .
The operation lever 42 is engaged with the engaging portion 33 of the aperture operation arm 32 in the aperture blade unit 30. Accordingly, when the aperture operation member 40 is rotated by the camera side interlocking unit 104 of the camera body 100, the aperture operation unit 40 performs the aperture operation of the aperture blade unit 30.

In the diaphragm mechanism 20 as described above, the diaphragm blade unit 30 attached to the third lens frame F3 that holds the third lens unit L3 moves in the direction of the optical axis OA by zooming and is supported by the mount cylinder 15. The distance from the diaphragm operating member 40 changes.
When the diaphragm blade unit 30 is moved relative to the diaphragm operation member 40 (change in distance), the engaging portion 33 of the diaphragm operation arm 32 in the diaphragm blade unit 30 is engaged along the operation lever 42 in the diaphragm operation member 40. Slide while maintaining the same state.
That is, the lengths of the aperture operation arm 32 in the aperture blade unit 30 and the operation lever 42 in the aperture operation member 40 are set to a length that can absorb the moving distance of the aperture blade unit 30.

Here, the length of the operation lever 42 in the aperture operation member 40 in the optical axis OA direction (Z-axis direction) and the position in the direction relative to the annular portion 41 will be described.
The operation lever 42 is engaged with the diaphragm operation arm 32 of the diaphragm blade unit 30 in the entire movement range (that is, the movement range of the third lens unit L3) in the optical axis OA direction (Z-axis direction) of the diaphragm blade unit 30. Need to be.
Accordingly, the length of the operation lever 42 in the optical axis OA direction (Z-axis direction) is a dimension obtained by adding the engaging portion 33 to the moving distance of the diaphragm blade unit 30 (the moving amount of the third lens unit L3).

  The position of the operation lever 42 in the optical axis OA direction (Z-axis direction) with respect to the annular portion 41 is such that the tip (back end) on the back side (Z-axis minus side) of the operation lever 42 is a component on the camera body 100 side. In a range not interfering with (quick return mirror 101 or the like), it is set so as to protrude to the back side (Z-axis minus side) from the annular portion 41 (back side extending portion 42R). In the present embodiment, as shown in FIGS. 2 and 3, the rear end of the rear side extending portion 42 </ b> R is positioned in the vicinity of the outer claw in the short cylindrical ring portion in the cylindrical bayonet mount 15 </ b> A in the mount cylindrical portion 15. doing.

  The operation lever 42 is extended from the back end of the back side extension 42R to the front side (Z-axis plus side) necessary length (front side extension 42F). That is, the operation lever 42 is a combination of the front side extending portion 42F that protrudes from the annular portion 41 to the front side and the rear side extending portion 42R that protrudes from the annular portion 41 to the back side. It is formed to have the required length.

  On the other hand, the aperture operation arm 32 in the aperture blade unit 30 has the engaging portion 33 at the operating lever 42 (front side extending portion 42F) at the telephoto end shown in FIG. Is set to a length that engages with an end on the front surface side (plus Z-axis side).

  As described above, the operation lever 42 in the aperture operation member 40 extends from the annular portion 41 to the required length from the back side (Z-axis minus side) to the front side (Z-axis plus side). For this reason, the amount of protrusion of the operation lever 42 from the annular portion 41 to the front side (Z-axis plus side) (the length of the front side extending portion 42F) is shorter than the total length of the operation lever 42. Thereby, the restriction | limiting with respect to the position and shape of the component (2nd lens group L2) located in the front side (Z-axis plus side) of the 3rd lens group L3 resulting from the operation lever 42 can be reduced.

That is, as shown in FIG. 5, which is a comparative example, in the drawing operation member 40 ′ formed by press working with metal, the operation lever 42 ′ is moved from the annular portion 41 ′ to the front surface from the viewpoint of manufacturing process, accuracy, cost, and the like. The required length is extended on the side (Z-axis plus side).
As a result, as shown in FIG. 6 which is a conceptual cross-sectional view of a lens barrel 10 ′ to which such a diaphragm operation member 40 ′ is applied, when the second lens group L2 approaches the third lens group L3, the operation lever 42 ′. Interfere with.
Therefore, a space 19 that avoids the operation lever 42 'is formed in the second lens frame F2' of the second lens group L2, and the position of the second lens group L2 is not set to the front side (Z-axis plus side). There is a configuration restriction such that it is not possible.

In this configuration, the restriction range by the operation lever 42 can be reduced. For this reason, the freedom degree of design becomes large and a compact structure is attained. In particular, when the second lens group L2 is a shake correction lens group, the design of the arrangement and the like of the image stabilization unit becomes easy. As a result, a low-cost and high-performance configuration is possible.
In FIG. 5 and FIG. 6, constituent elements having the same functions as those of the above-described embodiment are denoted by the same reference numerals.

As described above, this embodiment has the following effects.
(1) Since the aperture operation member 40 in the present embodiment is formed by injection molding using a mold with resin, it has a degree of freedom in shape as compared with a case of manufacturing with a metal material such as a press.
(2) Since there is a degree of freedom in shape, the operating lever 42 of the diaphragm operating member 40 is provided with a back side extending portion 42R extending on the back side (Z-axis minus side) from the annular portion 41, and the back side thereof. It is easy for the front side extension 42F to extend to the front side so that a necessary length can be obtained from the end of the front side. For this reason, the protrusion length of the front side extending portion 42F can be reduced, interference between the operation lever 42 and other components can be suppressed, and restrictions on the position and shape of the components can be reduced. As a result, the degree of freedom in design is improved, and a compact configuration can be achieved. Moreover, it can comprise at low cost.

(3) Further, since it is formed by injection molding using a mold with resin, it is easy to form the triangular wave-shaped light shielding structure 44 on the inner peripheral surface of the operation lever 42 of the aperture operation member 40. . Thereby, the light shielding sheet of another member and the operation | work which affixes it become unnecessary, and the cost reduction by reduction of material cost and a man-hour becomes possible.

(4) Furthermore, since it is formed by injection molding using a mold with resin, it is easy to form the inner peripheral end face 41B of the annular portion 41 of the aperture operation member 40 in a tapered shape. Thereby, it is possible to prevent the stray light reflected by the inner peripheral end face 41B from being mixed into the image light. As a result, it is possible to suppress the occurrence of flare due to the reflected light of the inner peripheral end face 41B. In addition, anti-reflection treatment or the like is not required, and the cost can be reduced by reducing the number of steps.

(Deformation)
The present invention is not limited to the above-described embodiment, and various modifications and changes as described below are possible, and these are also within the scope of the present invention.
(1) In the present embodiment, the present invention is applied to a digital camera. However, the present embodiment is not limited to this, and may be applied to a so-called silver salt camera using a film.
(2) Further, the configuration and arrangement of the lens group constituting the photographing optical system and the arrangement of the aperture blade unit 30 are not limited to the configuration of the present embodiment, but may be changed as appropriate.
In addition, although embodiment and a deformation | transformation form can also be used combining suitably, detailed description is abbreviate | omitted. Further, the present invention is not limited to the embodiment described above.

  1: camera, 100: camera body, 10: lens barrel, 15: mount tube portion, 15A: bayonet mount, 30: aperture blade unit, 31: aperture portion, 32: aperture operation arm, 33: engagement portion, 40 : Diaphragm operation member, 41: annular portion, 41A: sliding contact surface, 41B: inner peripheral end surface 41B, 42: operation lever, 42F: front side extending portion, 42R: back side extending portion, 43: light shielding structure , OA: Optical axis

Claims (5)

An annular shape centered on the optical axis, and a rotatable resin annular portion,
A first extending portion made of resin integrally formed with the annular portion so as to extend from the annular portion toward the subject along the optical axis direction;
A second extending portion made of resin integrally formed with the annular portion so as to extend from the annular portion toward the image side along the optical axis direction;
A diaphragm portion having a diaphragm blade, engaged with the first extension portion, and opened and closed by the rotation of the first extension portion;
With
The lens barrel, wherein the first extending portion and the second extending portion are formed continuously along the optical axis direction. The lens barrel according to claim 1 ,
Provided with a mounting cylinder part with a mounting part for mounting the camera body,
The second extending portion overlaps the mount cylinder portion in a radial direction;
A lens barrel characterized by The lens barrel according to claim 1 or 2 ,
The second extending portion is provided with a light shielding structure;
A lens barrel characterized by The lens barrel according to any one of claims 1 to 3 ,
The inner peripheral surface of the annular portion is inclined with respect to the optical axis;
A lens barrel characterized by An optical apparatus comprising the lens barrel according to any one of claims 1 to 4 .

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