JPH1031247A - Photometric information transmission device for taking lens - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a photometric information transmitting device for a photographic lens that eliminates variations in the rotational operation force of an aperture setting ring and enables aperture setting with a smooth operation force. An aperture setting ring (cam ring) for performing an automatic aperture stop operation, and an aperture link ring for transmitting aperture setting information of the aperture setting ring to a camera body, and a link leaf spring and fixed. Leaf spring 2
8 and a first engagement groove 26 engaged with each of these leaf springs.
a and a second engagement groove 26b. When the aperture setting ring is rotated to the rotation area of the aperture operation, the rotation of the aperture linkage ring 26 is locked, while the linkage leaf spring 27 is slid with respect to the aperture linkage ring 26, and the aperture setting ring is rotated. 18 can be rotated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photometric information transmitting device for transmitting photometric information on an aperture of a photographic lens having an aperture to a camera body.

[0002]

2. Description of the Related Art In a single-lens reflex camera, a subject is observed through a finder with an aperture of a photographing lens being opened, and photometry is performed in an open aperture state. Have been. This automatic aperture method is effective in brightening the finder field of view. However, on the other hand,
It is preferable that the subject image in the aperture state actually photographed is observed from the finder. For example, there is a case where the depth of focus is confirmed or a case where the soft focus effect of the soft focus photographing lens is confirmed. However, when the aperture is stopped down, the viewfinder field becomes dark when the aperture is small (the aperture diameter is small, the same applies hereinafter), and the subject image becomes difficult to see. For this reason, the present applicant has previously disclosed in Japanese Patent Laid-Open No. 3-157633,
The aperture is actually narrowed down from the opening to the predetermined intermediate aperture,
There has been proposed a photographic lens in which the aperture is not further reduced when the aperture is smaller than the predetermined intermediate aperture. According to this photographing lens, it is possible to confirm the subject image in the actual aperture state by narrowing down the aperture in an aperture area where the influence of the aperture on the finder visual field becomes dark, and more in the aperture area where the finder visual field is dark. It is possible to prevent the finder visual field from being darkened without performing aperture stop.

In such a photographic lens, when the iris setting ring provided on the photographic lens is operated, the iris is actually operated following the iris setting ring on the opening side of the intermediate aperture. On the smaller aperture side than the intermediate aperture, the aperture is not operated regardless of the operation of the aperture premise ring. Therefore, in order to recognize the aperture state of the taking lens on the camera body side, the operation of the aperture linking ring provided for transmitting the aperture information of the taking lens to the camera body is based on the aforementioned intermediate aperture. It is necessary to switch between the open side and the small aperture side. Therefore, the configuration shown in FIG. 8 is adopted by the technique of the above-mentioned publication.

FIG. 8 is a view showing the configuration of the aperture linkage ring in the technique of this publication.
Is interposed between the photographing lens and the camera body, is rotated around its axis according to the aperture setting of the photographing lens, and transmits an aperture value (so-called F-number) to the camera body according to the rotational position. Is what you do. here,
Now, assuming that the aperture of the taking lens is F1.4, the aperture is stopped down to F4 by following the setting of the aperture setting ring,
F value higher than F4, that is, F4 to F22 (minimum aperture)
Until the stop, aperture stop is not performed regardless of the setting of the aperture setting ring. In this case, the aperture link ring 126 does not rotate in the range of F1.4 to F4 regardless of the aperture change, and rotates in the range of F4 to F22 at a rotation angle corresponding to the aperture change. It shall be configured to be located.

In order to realize this function, according to the technique disclosed in the above publication, an arc-shaped groove 126a is formed in a circumferential area corresponding to F1.4 to F4 in an aperture linking ring 126, and an aperture setting ring (here, an aperture setting ring) is used. An aperture interlocking pin 118a provided on the cam ring 118) side is inserted into the arc groove 126a, and a tension spring 128 is mounted between the aperture interlocking pin 118a and a pin 126b provided upright on the aperture linking ring 126. Have been. A stopper projection 1 provided on the aperture linking ring 126 is provided on a camera body (not shown).
A stopper 127 is provided for contacting the stopper 26c and restricting its rotation position. The aperture link ring 12
The rotation position is transmitted to the camera body side by the information transmission piece 126d provided on the camera body 6.

With this configuration, when the aperture setting ring 118 is set in the range of F1.4 to F4, FIG.
As shown in (a), the aperture link pin 118a is moved only inside the arc-shaped groove 126a of the aperture link ring 126, so that the aperture link ring 126 is not rotated integrally with the aperture setting ring 118. At this time, the aperture linking ring 126 is held at the rotation position where the stopper protrusion 126 c is locked by the stopper 127 by the spring force of the tension spring 128. When the aperture setting ring 118 is set in a range exceeding F4 as shown in FIG. 8B, the aperture interlocking pin 118a comes into contact with the end of the circular arc groove 126a of the aperture link ring 126. By pressing this end, the aperture link ring 126 is rotated integrally with the aperture link pin 118a. From the above results, the aperture setting ring 1
18 in response to the operation of F1.
In the range of F4 to F4, the stopper 127 stops at the turning position of F4, and in the range of F4 to F22 exceeding F4, the stop position corresponds to the set turning position of the aperture setting ring.

[0007]

With the above-mentioned proposed aperture information transmission configuration, although the intended purpose is achieved, in the range of F1.4 to F4, the aperture interlocking pin 1 is used.
18a against the spring force of the tension spring 128 and the arc groove 1
This spring force is applied to the aperture interlocking pin 118a, that is, the aperture setting ring 118, for movement within the aperture 26a. On the other hand, in the region beyond F4, the aperture interlocking pin 118a directly presses and rotates the aperture link ring 126, so that the spring force of the tension spring 128 is not applied to the aperture setting ring 118. For this reason, the photographer rotates the aperture setting ring 118 against the spring force in the range of F1.4 to F4 or with the assistance of the spring force in the reverse case. In the region beyond the range, the aperture setting ring 118 is operated to rotate regardless of the spring force. As a result, it has been found that there is a difference in the rotational operation force of the aperture setting ring 118 at F4, and the operability varies, thereby reducing the operational feeling.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photometric information transmitting device for a photographic lens which eliminates such variation in the rotational operation force of the aperture setting ring and enables aperture setting with a smooth operation force. is there.

[0009]

According to the present invention, there is provided an aperture setting ring for setting an aperture of a photographic lens in which an aperture operation and an automatic aperture operation are performed, and aperture setting information of the aperture setting ring is transmitted to a camera body. And a stop link ring for locking the stop ring at a predetermined rotation position during the stop-down operation, and rotating together with the stop setting ring during the automatic stop-down operation. In the above, friction engagement means is provided between the aperture setting ring and the aperture linking ring, and the friction engagement means is provided when the aperture setting ring is rotated to the rotation area of the automatic aperture operation. The two rings are connected in the rotational direction with a large frictional engagement force with the linking ring, and the aperture setting ring is rotated to the rotation area of the aperture operation. The Rutoki characterized in that it is configured to operate sliding both rings in the rotational direction of the frictional engagement force as a small state. In this case, the aperture setting ring is provided with a cam ring that is rotated integrally therewith,
Switching between the narrowing-down operation and the automatic narrowing-down operation is performed according to the rotation position of the cam ring, and the aperture linking ring is frictionally engaged with the cam ring.

The friction engagement means is, for example, a link plate spring fixed to the cam ring and elastically contacted with the aperture link ring, and a fixed plate fixed to the photographing lens fixing portion and elastically contacted with the aperture link ring. A first spring provided on the throttle linkage ring and engaged with the linkage leaf spring and the fixed leaf spring, respectively;
And the second engaging groove, the frictional force due to the elastic contact of the linking leaf spring is larger than the frictional force due to the elastic contact of the fixed leaf spring, and the engaging force between the fixed leaf spring and the second engaging groove is A configuration in which the engagement force between the linkage leaf spring and the first engagement groove is set larger than the engagement force between the fixed leaf spring and the second engagement groove; Is done. Further, when the cam ring rotates the aperture link ring from the intermediate aperture position to the small aperture side, the engagement leaf spring engages with the first engagement groove to integrally rotate the aperture link ring. Preferably, a projection is provided.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing the entire configuration of a diaphragm of a photographing lens to which the present invention is applied, and is a diagram including the diaphragm configuration described in the above-mentioned publication. In this embodiment, similarly to the above, the open stop is set to F1.4, the minimum stop is set to F22, and the stop is set to F1.4.
An example is shown in which the aperture is stopped down to F4, and the aperture is not stopped when the aperture exceeds F4. In the drawing, dowels 11a and 11b are formed on the front and back of the diaphragm blade 11 which is representatively drawn. The aperture blade 11 is sandwiched by a relatively rotatable aperture support ring 12 and an aperture opening / closing ring 13. The cam grooves 12 a and the support holes 13 a provided in the aperture support ring 12 and the aperture opening / closing ring 13 are provided with the respective dowels. 11a,
11b is fitted. Thus, when the aperture support ring 12 and the aperture opening / closing ring 13 are relatively rotated, the aperture opening defined by the plurality of aperture blades 11 is changed.
Here, the aperture support ring 12 is rotated counterclockwise in the drawing,
Further, the aperture opening / closing ring 13 is relatively rotated clockwise in the opposite direction to change the aperture opening to the small opening side, that is, the aperture is closed.

The diaphragm support ring 12 has its own spring pin 12b and the spring pin 1 of the photographing lens barrel fixing portion.
4 is urged to rotate in a counterclockwise direction by a tension spring 15 stretched between them. The aperture support ring 12 is formed with a rotation range restricting pin 12c and an interlocking projecting piece 12d projecting in a direction parallel to the optical axis. The rotation range restricting pin 12c is fitted in an arcuate rotation range restricting groove 16 provided in the photographing lens barrel fixing portion, and
Regulate the absolute rotation position of. This rotation range regulating groove 16
The aperture support ring 12 is formed so as to be rotatable in a range from F1.4 (open) to F4 and not to rotate in a range exceeding F4. Further, the interlocking projecting piece 12d is inserted through a clearance groove 13b provided in a part of the outer peripheral edge of the aperture opening / closing ring 13 and extends to a cam ring 18 described later. The aperture opening / closing ring 13 has a driven protruding piece 13c extending parallel to an optical axis extending toward a release ring 22 described later.

The release ring 22 has a tension spring 25 extended between a spring hook pin 22e implanted in the release ring 22 and a spring hook pin 24 provided on the photographing lens barrel fixing portion.
Is biased clockwise. The release ring 22 has stopper pins 2 extending parallel to the optical axis.
2a, a body interlocking piece 22b, and an opening / closing ring interlocking piece 22c extending to the opposite side. The driven protruding piece 13c of the aperture opening / closing ring 13 is fitted into the forked tip opening 22d of the opening / closing ring interlocking piece 22c, and is integrated in the circumferential direction. Accordingly, the aperture opening / closing ring 13 is urged to rotate clockwise together with the release ring 22. The end of the body interlocking piece 22b protrudes into the camera body CB, and is brought into contact with the aperture driving lever 17 which is retracted clockwise in the figure in conjunction with the release operation of the camera body. At times other than the release operation, the release ring 22 is locked by the aperture drive lever 17 from rotating clockwise. Further, the stopper pin 22a is engaged with an intermediate lever 21 described later.

The cam ring 18 has a restricting projection 18a and an engagement projection 18b projecting in the radial direction. The engagement projection 18b is engaged with an aperture setting ring (not shown), and is integrally rotated by an aperture value setting operation using the aperture setting ring. The restricting protruding piece 18a protrudes in the axial direction toward the aperture support ring 12, and the tip thereof abuts clockwise on the interlocking protruding piece 12d. The rotation operation is transmitted to the interlocking projection 12d.
Further, on the peripheral surface of the cam ring 18, a cam 20 composed of a narrowed section (F1.4 to 4) 20a and a non-squeezed section (smaller aperture than F4; hereinafter, automatic narrowing section) 20b is formed. ing. Refinement section 20a
Is a portion having a constant diameter, and the automatic narrowing section 20b is a part whose diameter is gradually reduced from the narrowing section 20a.

A follower pin 21b of an intermediate lever 21 pivotally supported by a shaft 21a erected on a fixed portion of the photographing lens barrel contacts the cam 20 of the cam ring 18. The follower pin 21b is implanted in one arm 21c of the V-shaped intermediate lever 21.
The stopper pin 22a of the release ring 22 is in contact with the inner edge of the V-shape on the other arm 21d formed slightly longer than the arm 21c.

FIG. 2 is a partially exploded perspective view of the cam ring 18, as will be described later.
A linking plate spring 27 is provided on a part of the inner peripheral
Is fixed at its proximal end. The linking plate spring 27 is elastically deformable in the optical axis direction, that is, in the direction perpendicular to the surface of the cam ring 18. Touched. At the base end of the linking leaf spring 27, an engaging projection 27b is provided which protrudes toward the throttle linking ring 26 side.

On the other hand, an aperture linking ring 26 is arranged close to the cam ring 18 in the axial direction. The aperture linking ring 26 has a first engaging groove 26a formed by cutting out from the distal end portion 27a of the linking leaf spring 27 of the cam ring 18 to a circumferential angle region including the engaging protrusion 27b.
Further, a second engagement groove 26b is formed by cutting out at a position circumferentially different from the first engagement groove 26a. Then, with respect to the second engagement groove 26b, the cam ring 18 and the throttle link ring 26 are used together with the intermediate throttle (F4).
Is fixed to the fixing portion of the photographic lens barrel (not shown) at the base end portion 28b of the fixing plate spring 28 engaged with the second engaging groove 26b. The fixed leaf spring 28 is configured to be elastically deformable with respect to the back surface of the aperture linkage ring 26, and its tip end portion 28 a is bent and formed in a wedge shape and is in elastic contact with the back surface of the aperture linkage ring 26. Also, the above-mentioned base end portion 28 of the fixed leaf spring 28 is provided.
b is configured as a stopper protruding in the axial direction along the circumference of the aperture linking ring 26. A stopper protruding piece 26c is formed to bend at a part of the circumference of the aperture linking ring 26, and the base end 2 as a stopper of the fixed leaf spring 28 at the rotation position of the aperture linking ring 26 at F4.
8b, and is prevented from rotating further to the open side. Further, a transmission protrusion 26d for transmitting the rotational position of the aperture linkage ring 26 to the camera body CB is provided on a part of the other circumference of the aperture linkage ring 26.

Here, the frictional force caused by the linking leaf spring 27 being elastically contacted with the aperture linking ring 26 is set to be larger than the frictional force caused by the fixed leaf spring 28 being elastically contacted by the aperture linking ring 26. Is done. Further, the engagement force between the fixed leaf spring 28 and the second engagement groove 26b is set to be larger than the frictional force caused by the elastic contact of the linking leaf spring 27. Further, the engaging force between the link leaf spring 27 and the first engaging groove 26a is set to be larger than the engaging force between the fixed leaf spring 28 and the second engaging groove 26b. These settings can be made based on the spring force of each leaf spring, the angle and size of the wedge at each tip, and the like.

The operation of the photometric information transmitting device having the above configuration will be described. First, a description will be given of the aperture-down operation and the automatic aperture-down operation accompanying the aperture setting operation of the aperture setting ring, and the release operation at that time. In FIG. 1, in a state where the aperture setting ring is set to F1.4 (open), the regulating projection piece 18a of the cam ring 18 which is rotated together with the aperture setting ring maximizes the interlocking projection piece 12d of the aperture support ring 12. Press to hold the aperture support ring 12 in the aperture open position. When the aperture setting ring is rotated and set in the range from F1.4 to F4, the setting is performed according to the rotation of the restricting projecting piece 18a.
The aperture support ring 12 is rotated counterclockwise by the spring force of the tension spring 15. At this time, the cam ring 18
The cam 20 of the intermediate lever 2 has the narrowing section 20a in contact with the follower pin 21b of the intermediate lever 21.
As shown in FIG. 3 (a), 1 is held at its maximum clockwise rotation position. For this reason, the stopper pin 22
a is in a state of being restrained by the intermediate lever 21, so that the rotation of the release ring 22 and the aperture opening / closing ring 13 integrated with the release ring 22 is restrained. As a result, relative rotation occurs with respect to the aperture support ring 12, and the aperture is narrowed by the aperture blades 11. The aperture diameter at this time corresponds to the amount of relative rotation of the aperture support ring 12 with respect to the aperture opening / closing ring 13, whereby F1.4 to F1.4
The aperture set by the aperture setting ring in the range of 4 is narrowed down.

In this state, the aperture opening / closing ring 13 is restrained from rotating as described above. Therefore, when a release operation is performed on the camera body side, the aperture driving lever 17 simultaneously rotates the clock. The body interlocking piece 22b of the aperture opening / closing ring 13
Will not be moved.

When the aperture setting ring is used to set the aperture toward F22 which is smaller than the aperture F4, the cam ring 18 is integrally rotated counterclockwise, and the aperture support ring 12 is also rotated. Attempts are made to rotate counterclockwise by the spring force of the extension spring 15. However, since the rotation range restriction pin 12c of the aperture support ring 12 abuts on the end of the rotation range restriction groove 16, the subsequent rotation of the aperture support ring 12 in the counterclockwise direction is restricted. Therefore, only the cam ring 18 is rotated in the counterclockwise direction, whereby the automatic throttle section 20b of the cam 20 comes into contact with the follower pin 21b. Then, the intermediate lever 21 is
0 according to the cam shape of the automatic squeezing section 20b of FIG.
As shown in (b), the arm 21d is rotated in the counterclockwise direction, and the other arm 21d is moved away from the stopper pin 22a.

At this time, in the release ring 22 having the stopper pin 22a, the body interlocking piece 22b of the aperture opening / closing ring 13 integrated with the release pin 22a is rotated clockwise by the aperture drive leg 17 of the camera body. Since the release photographing lens 22 is locked, the release photographing lens 22 is not rotated, and the stopper pin 22a remains stopped at that position. Therefore, the other arm portion 21d of the intermediate lever 21 is moved to a position apart from the stopper pin 22a at intervals according to the aperture setting value due to the cam shape of the automatic aperture stop portion 20b. Also, at this time, since the aperture support ring 12 and the aperture opening / closing ring 13 are not both rotated, the aperture by the aperture blade 11 remains in the state of F4 described above.

In this state, when the release operation is performed on the camera body side, at the same time, the aperture driving lever 17
Is retracted in the clockwise direction, the locked state with respect to the body connecting piece 22b is released, so that the release ring 22 is rotated clockwise by the spring force of the tension spring 25,
The aperture opening / closing ring 13 is rotated clockwise integrally therewith. The rotation of the release ring 22 and the aperture opening / closing ring 13 is performed at a rotation angle at which the stopper pin 22a contacts the other arm 21d of the intermediate lever 21. Therefore, the aperture opening / closing ring 13 is rotated clockwise relative to the aperture support ring 12 whose rotation is locked, and the aperture blade 11
With this, the aperture is narrowed down with the aperture set by the aperture setting ring in the range from F4 to F22.

As described above, in this diaphragm device, F1.4
In the range from F4 to F4, when the cam ring 18 is rotated by the rotation of the aperture setting ring, the aperture performs the aperture operation accordingly. On the smaller aperture side than F4, even when the cam ring 18 is rotated by rotating the aperture setting ring, the aperture is not stopped down, and the aperture is set to the aperture set for the first time by the release operation. Thereby, especially in the case of the soft focus photographing lens, the soft focus effect can be confirmed by the finder without darkening the finder visual field in the range of F1.4 to F4. When the aperture is smaller than F4, the brightness of the finder visual field can be prioritized over the confirmation of the soft focus effect.

The aperture linking ring 26 is used to transmit the information of the aperture and the automatic aperture by the aperture device to the camera body. That is, the aperture linking ring 26 is used to reduce the number of apertures from F1.4 to F4.
Is stopped in the position corresponding to F4. Further, in a range on the smaller aperture side than F4, the aperture link ring 26 is rotated at a rotation angle that follows the aperture setting value of the aperture setting ring. Hereinafter, this operation will be described with reference to the front views of FIGS. 4 to 6 and the corresponding FIGS.
Description will be made with reference to schematic development cross-sectional views of (a) to (c).

When the aperture setting ring is set to the minimum aperture (F22), the cam ring 18 is at the pivot position shown in FIGS.
From 7a, the engagement protrusion 27b at the base end thereof is in a state of being inserted and engaged in the first engagement groove 26a of the throttle linking ring. At this time, the fixed leaf spring 28 has its tip 28a.
Are in elastic contact with the back surface of the aperture link ring 26.
Since the engagement force between the linking leaf spring 27 and the first engagement groove 26a is larger than the frictional force of the fixed leaf spring 28 elastically contacting the aperture linking ring 26, the cam ring 18 is moved toward the open aperture side. When rotated, the aperture linkage ring 26 is integrally rotated by the engagement force between the linkage leaf spring 27 and the first engagement groove 26a. At this time, the fixed leaf spring 28
Will slide on the back surface of the aperture linking ring 26. Therefore, the cam ring 18 and the aperture linkage ring 26 are integrated in the rotation direction, and the rotation of the cam ring 18, that is, the rotation of the aperture setting ring, becomes the rotation of the aperture linkage ring 26 as it is, and the aperture F 22. To F4 are transmitted to the camera body. In FIG. 7A, reference numeral 30 denotes a transmitted lever which is provided on the camera body CB side and to which aperture information due to the rotation operation of the aperture link ring 26 is transmitted. Note that this operation is the same when rotating from F4 to F22.

As shown in FIGS. 5 and 7 (b), the cam ring 18 and the aperture linking ring 26 are intermediate apertures.
When the number reaches 4, the stopper protrusion 26c abuts against the stopper 28b, which is the base end of the fixed leaf spring 28, and the rotation of the aperture linking ring 26 thereafter is prevented. At the same time, the distal end 28a of the fixed leaf spring 28 is fitted into the second engagement groove 26b. Therefore, the cam ring 18 further has
When it is rotated further toward the open stop side, the distal end portion 27a of the linking leaf spring 27 formed in a wedge shape becomes the first engagement groove 26a.
Is projected from the first engagement groove 26a over the inner edge portion of the ring, and thereafter elastically contacts the surface of the aperture linking ring 26, and moves while sliding on the surface with the frictional force associated with this elastic contact force. As a result, only the cam ring 18 is turned to the open stop side. Therefore, the aperture setting ring changes from F4 to F
In the region set to 1.4, the aperture linkage ring 26 is
It will be held in a stopped state at position 4.

On the other hand, when the cam ring 18 is rotated in the small drawing direction in the range from F1.4 to F4, as shown in FIGS. 6 and 7C, the link leaf spring 28 and the second Is set to be larger than the frictional force of the linking leaf spring 27, so that the tip end 27 a of the linking leaf spring 27 is brought into contact with the surface of the throttle linking ring 26 by the rotation of the cam ring 18. Even if a frictional force is generated, the frictional force merely slides on the surface of the aperture linking ring 26, and the aperture linking ring 26 is not rotated. Accordingly, even in this rotation range, the state in which the aperture linking ring 26 is stopped at the position F4 is maintained regardless of the rotation of the aperture setting ring.

Then, when the cam ring 18 is rotated to the position F4, the linking plate spring 27 falls again into the first engagement groove 26a as shown in FIGS. 27 and the first engagement groove 26a are engaged. For this reason, the rotational power of the cam ring 18 is
The light is transmitted to the aperture linking ring 26 via b. And
The engagement force between the linking leaf spring 27 and the first engagement groove 26a is set to be larger than the engagement force between the fixed leaf spring 28 and the second engagement groove 26b. 26, the tip 28a of the wedge-shaped fixed leaf spring 28 is moved to the second engagement groove 26.
It gets over the inner edge of b. Therefore, after that, the fixed leaf spring 28 has the distal end portion 28a which is
6 is only in frictional contact with the back surface of F6
The cam ring 18 and the aperture link ring 26 are integrally rotated in the rotation direction until the rotation reaches 22. This is as described above.

Accordingly, in this configuration, the aperture linking ring 26 is rotated together with the cam ring 18 in the range of the automatic aperture operation (F4 to F22), and is linked with the cam ring 18 in the area of the aperture operation (F1.4 to F4). Although it is released, the relative rotation with respect to the cam ring 18 is restricted by the engagement state of the fixed leaf spring 28 and the second engagement groove 26b at that time. No spring is required for locking in the F4) position, so that no spring force is applied to the cam ring 18. For this reason, there is no difference in the rotational operation force of the cam ring 18, that is, the aperture setting ring between the aperture operation and the automatic aperture operation.
As a result, the turning operation force for setting the aperture is made uniform over the entire aperture range, and the operability is improved.

In the above embodiment, the intermediate aperture, which is the aperture value for switching between the aperture operation and the automatic aperture operation, is F
4, the aperture can be set to another aperture such as F2.8 or F5.6 depending on other requirements such as the aperture of the taking lens. Further, the positions and shapes of the linking leaf spring and the fixed leaf spring, and the positions and shapes of the first and second engagement grooves are not limited to the configuration of the above-described embodiment.
Needless to say, it can be arbitrarily designed and arranged.

[0032]

As described above, according to the present invention, the aperture setting ring of the photographing lens in which the aperture operation is performed in the range from the open aperture to the intermediate aperture, and the automatic aperture operation is performed in the range from the intermediate aperture to the small aperture side. A friction engagement means is provided between the aperture setting ring and an aperture linking ring for transmitting aperture setting information to the camera body. When the aperture setting ring and the aperture linking ring are in a rotational engagement position, the frictional engagement force between the aperture setting ring and the aperture linking ring is increased to connect the two rings in the rotational direction. Since the engagement force is set to be small and the ring is slid in the rotational direction between the two rings, the linkage between the aperture setting ring and the aperture linkage ring is particularly broken. When this is done, it becomes possible to lock the aperture linkage ring at a predetermined aperture position by the aperture setting ring, so that a spring for locking the aperture linkage ring at a predetermined position as in the conventional art is not required, and this spring force is reduced. Eliminating the increase in the rotational operation force of the aperture setting ring, which is the cause, the rotational operation force of the aperture setting ring at the time of aperture setting can be made uniform over the entire aperture range, improving the operability of the aperture setting operation, The effect that a smooth aperture setting operation can be realized is obtained.

[Brief description of the drawings]

FIG. 1 is a partially exploded schematic perspective view showing an entire configuration of an apparatus according to an embodiment of the present invention.

FIG. 2 is a partially exploded perspective view of a main part of the present invention.

FIG. 3 is a front view of a main part for describing an operation of narrowing down and automatic narrowing down.

FIG. 4 is a first view of a front view for explaining a transmission operation at the time of an automatic narrowing-down operation in the present invention.

FIG. 5 is a second front view for explaining the transmission operation during the automatic narrowing-down operation in the present invention.

FIG. 6 is a third view of the front view for explaining the transmission operation during the automatic narrowing-down operation in the present invention.

FIG. 7 is a schematic sectional view at the time of each operation of FIGS. 4 to 6;

FIG. 8 is a front view showing an operation state of an example of a conventional transmission device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 aperture blade 12 aperture support ring 13 aperture opening / closing ring 17 aperture drive lever 18 cam ring 20 cam 21 intermediate lever 22 release ring 26 aperture linkage ring 27 linkage leaf spring 28 fixed leaf spring 30 transmitted lever

Claims (6)

[Claims] In the range from an open aperture to an intermediate aperture, an aperture operation is performed in which the aperture diameter is changed following the set value of an aperture setting ring, and the aperture setting ring is set in a range from the intermediate aperture to a small aperture side. An aperture stop ring for transmitting aperture setting information of the aperture setting ring to a camera body, and a photographing lens that performs an automatic aperture operation in which the aperture diameter is held at the aperture diameter of the intermediate aperture regardless of the value;
The aperture linking ring is locked at a predetermined rotational position during the aperture stop operation, and is rotated together with the aperture setting ring during the automatic aperture stop operation. Friction engagement means is provided between the setting ring and the aperture linkage ring, and the friction engagement means is connected to the aperture setting ring and the aperture linkage when the aperture setting ring is rotated to the rotation area of the automatic aperture operation. When the friction engagement force with the ring is large, the two rings are connected in the rotation direction, and when the aperture setting ring is rotated to the rotation area of the aperture operation, the friction engagement force is reduced and the two rings are rotated in the rotation direction. A photometric information transmitting device for a photographic lens, characterized in that the photometric information transmitting device is configured to make a sliding operation. 2. An aperture setting ring is provided with a cam ring which is rotated integrally therewith. The rotation of the cam ring switches between the aperture operation and the automatic aperture operation. 2. The photometric information transmitting device for a photographing lens according to claim 1, wherein the photometric information transmitting device is frictionally engaged with the cam ring. And a fixed leaf spring fixed to the cam ring and elastically contacting the aperture linking ring, a fixed leaf spring fixed to the photographing lens fixing portion and elastically contacted with the aperture linking ring. And a first and a second engagement groove provided on the aperture linking ring and engaged with the linking leaf spring and the fixed leaf spring, respectively, wherein a frictional force caused by elastic contact of the linking leaf spring is fixed leaf spring. And the engagement force between the fixed leaf spring and the second engagement groove is greater than the friction force due to the elastic contact of the linking leaf spring, and furthermore, the linking leaf spring and the first linking element. 3. The photometric information transmitting device for a photographic lens according to claim 2, wherein the engaging force with the mating groove is set to be larger than the engaging force between the fixed leaf spring and the second engaging groove. 4. The linkage leaf spring engages with the first engagement groove when the cam ring rotates the aperture linkage ring from the intermediate aperture position to the small aperture side, and integrally rotates the aperture linkage ring. 4. The photometric information transmitting device for a photographing lens according to claim 3, further comprising an engaging projection to be moved. 5. The linking and fixed leaf springs each have a base end fixed to the cam ring and a tip end supported to be elastically deformable in the thickness direction of the throttle linking ring. Photometric information transmission device for photographic lens. 6. The photometric information of the photographing lens according to claim 5, wherein a stop means is provided for stopping the aperture linking ring at the intermediate aperture position and locking the aperture link ring from rotating toward the open aperture side. Transmission device.