JP4087089B2 - Manual aperture device for interchangeable lens barrel and shared manual aperture device - Google Patents

Description

[0001]
【Technical field】
The present invention relates to a manual diaphragm device that can be mounted in common with a plurality of interchangeable lenses having different specifications, and in particular, when the aperture of each interchangeable lens is open, the diaphragm blades do not protrude inside the photographing aperture of each interchangeable lens. The present invention relates to a manual aperture device for an interchangeable lens barrel and a shared manual aperture device that can fully open a photographing aperture.
[0002]
[Prior art and its problems]
As an example of a manual diaphragm device mounted on an interchangeable lens, an aperture setting ring that is rotated around an optical axis that is fitted around a lens barrel of the interchangeable lens, and a manual cam plate that rotates integrally with the aperture setting ring And a diaphragm opening / closing plate that is driven to rotate around the optical axis by a diaphragm member on the camera body side, and changes the size of the diaphragm aperture by the plurality of diaphragm blades from the open state to the diaphragm direction, and in conjunction with the rotation of the diaphragm opening / closing plate. An intermediate lever having a center of rotation outside the optical axis, and a cam formed on the manual cam plate for limiting the rotation range of the intermediate lever according to the aperture value set by the aperture setting ring. Some have a surface.
[0003]
When mounting this manual diaphragm device in common to multiple interchangeable lenses with different specifications, due to the difference in the specifications of each interchangeable lens, even if the aperture setting ring of each interchangeable lens is set to the open aperture value, The aperture diameter of each interchangeable lens may be slightly different. With certain interchangeable lenses, the aperture blades completely open the shooting aperture provided in the interchangeable lens, while other interchangeable lenses In the lens, part of the diaphragm blades may protrude inside the photographing aperture, and the photographing aperture may not be fully opened.
[0004]
In order to solve such a problem, the above-described manual cam plate is replaced with a manual cam plate having a cam surface having a shape different from that of the above-described cam surface, and the rotation range of the intermediate lever is reduced by this cam surface. When the aperture is widened, the aperture blades may be rotated to a position where the photographing aperture is fully opened.
[0005]
However, when replacing the manual cam plate with another manual cam plate in this way, the replacement operation of the manual cam plate is troublesome and the replacement cost of the manual cam plate becomes a heavy burden.
[0006]
OBJECT OF THE INVENTION
In the present invention, a manual diaphragm device can be commonly mounted on a plurality of interchangeable lenses having different specifications, and the photographing aperture of the interchangeable lens can be completely opened at the open aperture regardless of which interchangeable lens is mounted. To provide a manual diaphragm device and a common manual diaphragm device for an interchangeable lens barrel that do not require a large-scale component replacement work and can minimize the cost of component replacement when mounted on an interchangeable lens. Objective.
[0007]
SUMMARY OF THE INVENTION
The lens barrel of the present invention is a manual aperture device that is commonly used for a plurality of interchangeable lens barrels having different open diameters. An aperture setting ring that is rotated around the optical axis, and the aperture setting ring are integrated. A rotating cam member, a diaphragm opening / closing plate that is driven to rotate around the optical axis by a diaphragm member on the camera body side, and that changes the size of the diaphragm aperture by the plurality of diaphragm blades from the open state to the diaphragm direction. An intermediate lever that rotates in conjunction with the rotation and has a rotation center outside the optical axis, and the cam member that limits the rotation range of the intermediate lever according to the aperture value set by the aperture setting ring. The rotation range of the intermediate lever when the aperture setting ring is at the open F value, which is selectively mounted on the cam member according to the cam surface and the open diameter of the plurality of interchangeable lens barrels, By cam face It is characterized by having an open F value setting member to expand the aperture by diaphragm blades spread than the dynamic range, the.
[0013]
An engagement pin projecting from the intermediate lever can be brought into contact with the cam surface to limit the rotation range of the intermediate lever.
[0014]
The open F value setting member may be an adjustment cam that abuts the engagement pin and separates the engagement pin from the cam surface.
[0015]
Furthermore, the adjustment cam can be a plurality of cylindrical shaft members that are selectively attached to the cam member and have different diameters.
[0016]
The adjusting cam may include a columnar shaft member and an eccentric pin attached to the cam member and protruding from the shaft member.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the manual diaphragm device of the present invention is mounted on two types of interchangeable lenses A and B having different specifications will be described with reference to the accompanying drawings.
[0018]
1 to 5 show an example in which a manual diaphragm device is attached to the interchangeable lens A of the first specification.
[0019]
A lens group L is attached to the front end portion inside the lens barrel 1, and an engagement portion engageable with a lens barrel mounting portion of a camera body (not shown) is attached to the rear end portion of the lens barrel 1. 1a is formed.
[0020]
A diaphragm setting ring 3 that is rotatable around the optical axis O is fitted in an annular recess 1 b formed on the outer peripheral surface of the lens barrel 1.
Between the aperture setting ring 3 and the lens barrel 1, there is provided a click stop mechanism (not shown) for positioning the position of the aperture setting ring 3 in the rotational direction in three stages. By this click stop mechanism, the aperture setting is performed. The ring 3 can be positioned at three positions: an open throttle position (see FIG. 3), an intermediate throttle position (see FIG. 4), and a minimum throttle position (see FIG. 5).
[0021]
The lens barrel 1 is provided with a through hole 1c that penetrates the lens barrel 1 in the radial direction and is wider in the circumferential direction than an engagement piece 5a described later. A recess 3a is formed on the surface.
[0022]
Inside the lens barrel 1, a manual cam plate (cam member) 5 having a circular shape in the center and having a circular shape in front view is fitted so as to be rotatable around the optical axis O. The manual cam plate 5 The engaging piece 5a projecting from the outer peripheral portion of the aperture is fitted into the recess 3a of the aperture setting ring 3 through the through hole 1c.
[0023]
The manual cam plate 5 is provided with a screw hole 5b for screwing a screw portion 19a of an adjustment cam 19 to be described later, and an engagement pin 15b to be described later is engaged with the outer peripheral portion of the manual cam plate 5. A cam surface 5c is formed.
[0024]
An annular aperture opening / closing cam plate 7 (aperture opening / closing plate) is fitted inside the lens barrel 1 so as to be rotatable around the optical axis O, and an engagement groove 15a of an intermediate lever 15 described later is provided on the rear surface. A power transmission pin 7a that engages with is projected.
[0025]
On the aperture opening / closing cam plate 7, a rearward power transmission piece 7b in the direction of the optical axis O is projected.
The power transmission piece 7b is loosely fitted in a guide groove 5d formed in the inner peripheral portion of the manual cam plate 5 and wider in the circumferential direction than the power transmission piece 7b, and its rear end portion is in the camera body. It is linked to a provided narrowing member (not shown) that operates in conjunction with a shutter button (not shown).
[0026]
Nine cam grooves 7c are formed in the diaphragm opening / closing cam plate 7 so as to be arranged in the circumferential direction. Each cam groove 7c has a pin 9a projecting from the rear surface of nine diaphragm blades 9, respectively. Match. A support pin 9 b protruding from the front surface of each diaphragm blade 9 is rotatably fitted in a support hole 11 a of an annular support plate 11 fixed to the support plate mounting surface 1 d of the lens barrel 1.
[0027]
A circular photographing opening 11 b centering on the optical axis O is formed in the center of the support plate 11. Three long holes 11c are formed in the support plate 11 in the circumferential direction at intervals of 120 °, and the adjustment screw 13 inserted in each long hole 11c is formed in the screw hole 1e formed in the support plate mounting surface 1d. By screwing, the support plate 11 is fixed to the support plate mounting surface 1d.
[0028]
Between the support plate 11 and the aperture opening / closing cam plate 7 is a storage space S for storing the aperture blades 9. Between the support plate 11 and the aperture opening / closing cam plate 7, the aperture opening / closing cam plate 7 is opposed. A biasing spring (not shown) that biases rotation in the clockwise direction is provided.
[0029]
On the intermediate lever mounting surface 1 f of the lens barrel 1, an intermediate lever 15 having a substantially fan shape in front view is pivotally attached with a pin 17.
The intermediate lever 15 is provided with an engagement groove 15a that engages with the power transmission pin 7a, and an engagement pin 15b that selectively contacts a cam surface 5c and an adjustment cam 19 to be described later projects on the rear surface. It is installed.
[0030]
The above-described aperture setting ring 3, manual cam plate 5, aperture opening cam plate 7, aperture blade 9, support plate 11, and intermediate lever 15 constitute a manual aperture device.
[0031]
Next, the operation of the above-described first specification interchangeable lens A will be described.
[0032]
As shown in FIG. 3, when the aperture setting ring 3 is moved to the open aperture position without pressing the shutter button, the aperture opening / closing cam plate 7 is engaged with the engagement pin 15b of the intermediate lever 15 by the urging force of the urging spring. Is rotated counterclockwise until it comes into contact with the cam surface 5c, and each diaphragm blade 9 opens the photographing opening 11b fully.
[0033]
When the shutter button is pressed in this state, the power transmission piece 7b and the aperture opening / closing cam plate 7 are rotated in the clockwise direction by the aperture member in the camera body, and each aperture blade 9 protrudes to the inside of the imaging aperture 11b to project the imaging aperture 11b. Is fully closed (not shown).
[0034]
As shown in FIG. 4, when the aperture setting ring 3 is moved to the intermediate aperture position without pressing the shutter button, the aperture diameter becomes smaller than that in FIG. 3, and the aperture setting ring 3 is moved as shown in FIG. When moved to the minimum aperture position, the aperture diameter is minimized.
When the shutter button is pressed in the state shown in FIGS. 4 and 5, each diaphragm blade 9 protrudes inside the photographing opening 11b to fully close the photographing opening 11b (not shown).
[0035]
Next, an example in which a manual diaphragm device is mounted on the second specification interchangeable lens B will be described with reference to FIGS.
It should be noted that components having the same functions as the components of the first specification interchangeable lens A but having different specifications are not given the same reference numerals with “′” added to the components of the first specification. Detailed description is omitted.
[0036]
A lens group L ′ and a manual diaphragm device are attached to the lens barrel 1 ′, and, like the interchangeable lens A, the diaphragm diameter can be changed when the shutter button is not operated by rotating the diaphragm setting ring 3. Can do.
[0037]
In this interchangeable lens B, the aperture setting ring 3 has an intermediate aperture position (state shown in FIG. 8) and a minimum aperture position (state shown in FIG. 9) because the focal length of the lens group L ′ is different from that of the lens group L. When the shutter button is not operated, the aperture diameter is set smaller than that of the first specification interchangeable lens A.
The aperture diameter is set by adjusting the positional relationship between the adjustment screw 13 and the long hole 11c.
[0038]
If the aperture diameter when the aperture setting ring 3 is at the intermediate aperture position and the minimum aperture position is made smaller than the interchangeable lens A of the first specification in this way, as shown in FIG. Becomes smaller than the diameter of the photographing aperture 11b, and a part of the diaphragm blade 9 is located inside the photographing aperture 11b, and the photographing aperture 11b cannot be completely opened. Therefore, the adjustment cam 19 is attached to the manual cam plate 5 by screwing the screw portion 19 a of the adjustment cam (open F value setting member) 19 into the screw hole 5 b of the manual cam plate 5.
The adjustment cam 19 is a cylindrical member, and a part of the outer peripheral surface thereof is located outside the cam surface 5c when viewed from the optical axis O, as shown in FIGS.
[0039]
By attaching such an adjustment cam 19 to the manual cam plate 5, as shown in FIG. 7, the open / close cam plate 7 rotated in the clockwise direction by the urging force of the urging spring at the time of the open aperture is interlocked. Since the intermediate lever 15 is rotated until the engagement pin 15b comes into contact with the adjustment cam 19, the clockwise rotation range of the aperture opening / closing cam plate 7 becomes larger than the state shown in FIG.
As a result, each diaphragm blade 9 is pulled up into the storage space S, and the photographing opening 11b is completely opened.
[0040]
According to this embodiment as described above, the same manual diaphragm device is commonly mounted on the plurality of interchangeable lenses A and B having different specifications by simply attaching and detaching the adjustment cam 19 to the screw hole 5b of the manual cam plate 5. In any of the interchangeable lenses A and B, the photographing aperture 11b can be completely opened at the open aperture.
[0041]
At this time, it is not necessary to replace the manual cam plate 5 with a separate manual cam plate as in the prior art, and the adjustment cam 19 can be simply attached and detached. Cost can be kept to a minimum.
[0042]
When a manual diaphragm device is mounted on an interchangeable lens (not shown) having a specification different from the above specification, an adjustment cam (not shown) having a diameter different from that of the adjustment cam 19 is screwed into the screw hole 5b. Then, it is only necessary to adjust the lifting amount of the diaphragm blade 9 when the aperture is fully opened by the adjustment cam.
In addition, instead of using the adjustment cams having different diameters as described above, if one adjustment cam (not shown) having an eccentric screw portion is prepared, a plurality of interchangeable lenses having different specifications can be obtained by one adjustment cam. It is possible to adjust the lifting amount of the diaphragm blades 9 when the aperture is fully opened.
[0043]
【The invention's effect】
According to the present invention, a manual aperture device can be commonly mounted on a plurality of interchangeable lenses having different specifications, and the photographing aperture of the interchangeable lens can be completely opened at the time of the open aperture, regardless of which interchangeable lens is mounted, and When the lens is mounted on another interchangeable lens, a large-scale component replacement operation is not required, and the component replacement cost can be minimized.
[Brief description of the drawings]
FIG. 1 is a schematic view of an essential part of an interchangeable lens A according to an embodiment of the present invention viewed from the side.
FIG. 2 is an exploded perspective view of the main part of the interchangeable lens A, similarly.
3 is an enlarged vertical front view of the interchangeable lens A at the time of an open stop along the line III-III in FIG.
4 is an enlarged longitudinal sectional front view similar to FIG. 3 at the time of an intermediate aperture of the interchangeable lens A. FIG.
FIG. 5 is an enlarged vertical front view similar to FIG. 3 when the interchangeable lens A is at the minimum aperture.
6 is a schematic view similarly seen from the side of the main part of the interchangeable lens B. FIG.
7 is an enlarged longitudinal front view of the interchangeable lens B when the aperture stop is taken along the line VII-VII in FIG.
8 is an enlarged longitudinal sectional front view similar to FIG. 7 when the interchangeable lens B is at an intermediate aperture. FIG.
FIG. 9 is an enlarged vertical front view similar to FIG. 7 when the interchangeable lens B is at the minimum aperture.
10 is an enlarged longitudinal front view similar to FIG. 7 at the time of full aperture when the adjustment cam is removed from the interchangeable lens B. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Lens barrel 1 'Lens barrel 1a Engagement part 1a' Engagement part 1b Annular recessed part 1b 'Annular recessed part 1c Through hole 1c' Through hole 1d Support plate attachment surface 1d 'Support plate attachment surface 1e Screw hole 1e' Screw hole 1f Intermediate lever mounting surface 1f 'Intermediate lever mounting surface 3 Aperture setting ring 3a Recess 5 Manual cam plate (cam member)
5a engagement piece 5b screw hole 5c cam surface 5d guide groove 7 aperture opening / closing cam plate (diaphragm opening / closing plate)
7a Power transmission pin 7b Power transmission piece 7c Cam groove 9 Diaphragm blade 9a Pin 9b Support pin 11 Support plate 11a Support hole 11b Shooting opening 11c Long hole 13 Adjustment screw 15 Intermediate lever 15a Engagement groove 15b Engagement pin 17 Pin 19 Adjustment cam (Open F value setting member)
19a Thread part A Interchangeable lens B Interchangeable lens L Lens group L 'Lens group O Optical axis S Storage space

Claims (5)

A manual diaphragm device commonly used for a plurality of interchangeable lens barrels having different open diameters,
  An aperture setting ring that is rotated around the optical axis;
  A cam member that rotates integrally with the aperture setting ring;
  A diaphragm opening / closing plate that is driven to rotate around the optical axis by a diaphragm member on the camera body side, and changes the size of the diaphragm aperture by a plurality of diaphragm blades from the open state to the diaphragm direction;
  An intermediate lever having a center of rotation outside the optical axis that rotates in conjunction with rotation of the aperture opening and closing plate;
  A cam surface formed on the cam member for limiting the rotation range of the intermediate lever according to the aperture value set by the aperture setting ring;
  The rotation range of the intermediate lever that is selectively mounted on the cam member according to the open diameters of the plurality of interchangeable lens barrels when the aperture setting ring is at the open F value is adjusted by the cam surface of the cam member. An open F-number setting member that expands the diaphragm opening by the diaphragm blades to extend from the moving range;
A common manual diaphragm device for an interchangeable lens barrel, characterized by comprising: 2. The interchangeable lens barrel common manual diaphragm device according to claim 1, wherein an engagement pin protruding from the intermediate lever is brought into contact with the cam surface to limit a rotation range of the intermediate lever. A common manual aperture device for lens barrels. 3. The interchangeable lens barrel shared manual diaphragm device according to claim 2, wherein the open F value setting member is an adjustment cam that abuts the engagement pin and separates the engagement pin from the cam surface. A common manual diaphragm device for lens barrels. 4. The interchangeable lens barrel common manual diaphragm device according to claim 3, wherein the adjustment cam is a plurality of cylindrical shaft members having different diameters, which are selectively attached to the cam member. Common manual throttle device. 4. The interchangeable lens barrel shared manual diaphragm device according to claim 3, wherein the adjustment cam includes a columnar shaft member and an eccentric pin that protrudes from the shaft member and is attached to the cam member. A common manual diaphragm device for lens barrels .

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