JPH0136923B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aperture control device for an interchangeable lens, and more particularly, to an aperture control device capable of switching modes of a multi-mode camera.

Single-lens reflex cameras employ automatic exposure control methods such as an aperture priority method, a shutter speed priority method, or a program shutter method. Each of these automatic exposure control methods has its advantages and disadvantages, and the question of which method is more advantageous in use is a question of superiority or inferiority that arises from the combination of the characteristics of each and the situation of the subject. can.

In other words, the shutter speed is selected based on the movement of the subject, and the lens aperture not only controls the amount of light hitting the film in area, but also works to increase the depth of field and resolution.

In recent years, camera bodies and interchangeable lenses have come equipped with a built-in mechanism that allows the photographer to select between aperture priority, shutter speed priority, or program shutter modes that control the appropriate exposure by combining aperture and shutter speed, depending on the shooting situation. , so-called multi-mode cameras have been proposed and have already been implemented.

Next, the operating method of each of the above modes will be explained, and the problems thereof will be mentioned.

FIG. 1 is a diagram for explaining a mode switching operation of a multi-mode camera. When setting aperture priority,
The aperture ring 1 of the lens is set to a manual preset aperture, the shutter dial 22 is set to auto (AE), and the shutter speed is controlled based on the aperture value so that appropriate exposure is achieved. When prioritizing shutter speed, set the lens aperture ring 1 to auto so that it can change from maximum aperture to minimum aperture.
Based on the shutter speed set with the shutter dial 22 on the camera body side, the amount of aperture of the lens is controlled on the camera body side so as to obtain proper exposure. Furthermore, in the program shutter mode, by setting both the aperture ring 1 of the lens and the shutter dial 22 of the camera body to auto, proper exposure can be controlled by a combination of aperture and shutter speed.

When manufacturing a camera capable of switching between modes in this way, especially in the case of a single-lens reflex camera, compatibility with the body or lens of a conventional camera must be taken into consideration. Therefore, the conventional aperture ring 1
In addition to the manual preset range that can be manually operated, an automatic preset position must be newly added.

However, simply providing the automatic preset position in the same mechanism as the minimum aperture value in the manual preset range makes it difficult to distinguish between the two, resulting in poor operability and erroneous operation.

Even if the automatic preset position is set at a position further stopped down from the minimum aperture value, the automatic preset will use the smallest possible aperture for the lens, and when manually controlling the aperture, stop the aperture one or more stops short. This is inconvenient, and the aperture mechanism becomes complicated.

To solve this problem, Japanese Patent Publication No. 53-32703 discloses a system in which when switching to the automatic preset position, the aperture value transmission member is disengaged from the aperture preset adjustment member, and the aperture value is transferred to the camera body. A method of interlocking with a control mechanism has been disclosed, but the operating range is wide and the spring on the lens side inevitably becomes strong, requiring a large force on the aperture control mechanism of the main body. In addition, since the spring must be charged each time the release is released, the camera body must link it to the winding as a driving force source, which puts too much load on the winding torque, and the camera This resulted in a significant deterioration in the feeling of hoisting operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide an aperture control device for an interchangeable lens that solves the above-mentioned problems, allows easy discrimination of each mode position, has a simple mechanism, and has good operability.

In order to achieve the above object, an interchangeable lens aperture control device according to the present invention is an interchangeable lens aperture control device that can select between a manual preset range used in aperture priority mode and an automatic preset position used in shutter priority mode and preset shutter mode. A lens aperture control device includes a preset aperture ring having a signal piece that inputs to a photometry circuit on the camera side that the camera is at an automatic preset position when the aperture moves beyond the maximum aperture value, and a preset aperture ring that is driven to rotate. an aperture value transmission member that engages with the camera side transmission member and inputs the preset aperture value to the camera side photometry circuit;
The aperture value transmission member is biased and supported in the direction of engagement with the preset aperture ring, and when the aperture value transmission member is coupled at the first position, the assembly of the preset aperture ring and the aperture value transmission member is secured to the lens fixing member. , move it from the minimum aperture value to the maximum aperture value,
Only when the aperture value transmission member is at the maximum aperture value or when it has moved beyond the maximum aperture value and is at the automatic preset position, the coupling is released by operating the external operating member from the preset aperture ring and the preset aperture is set. The clutch mechanism includes a clutch mechanism that allows movement of the ring to an automatic preset position or movement of the preset aperture ring to the maximum aperture value and coupling to the aperture value transmission member.

According to the above structure, the object of the present invention can be completely achieved.

Hereinafter, the present invention will be explained in more detail with reference to the drawings and the like.

FIG. 2 is a perspective view showing the overall configuration of a camera using the aperture control device according to the present invention.

In the aperture priority mode, the preset aperture value of the lens 10 is set by always displacing the interlocking member _B1 biased by a spring towards the open side on the camera body 20 side. This displacement is converted into the number of steps to stop the lens from its open position, and is input to the photometry circuit in the camera body 20.

The automatic diaphragm lever 11 is operated by a diaphragm lever 21 that is linked to the quick return mechanism of the mirror of the camera body 20 so that it is always open regardless of the preset aperture value before the shutter is released. . When the shutter is released, the aperture lever 21 of the main body 20 is retracted from the automatic aperture lever 11 of the lens 10 by the mirror's quick return mechanism, and the aperture mechanism of the lens 10 starts to stop down to the preset aperture value. It will be done.

At the same time as the mirror is restored by the shutter exposure end signal, the aperture lever 21 on the camera body 20 acts in the opposite direction to the aperture direction against the spring acting in the aperture direction on the lens 10 side, opening the lens. Make it.

When the preset aperture ring 1 is switched from the manual preset range to the so-called automatic preset position, where the aperture is narrowed down by aperture control based on calculations of the photometric circuit of the camera body 20, information about the switching is transmitted to the camera body 20 by the signal piece 1d. It is input to the photometry circuit from receiving lever _B2 . The receiving lever _B2 automatically returns to its original position when the preset aperture ring 1 is returned to the manual preset range.

Furthermore, in order to input information on how many steps the lens 10 can be stopped down from its maximum aperture to the minimum aperture to the photometric calculation circuit of the main body 20, when switching to the automatic preset position on the lens 10 side,
The aperture value transmission lever 6b is fixed at the preset position of the minimum aperture aperture, and the information is transmitted to the aperture value transmission member _B1 on the main body side. Of course, for this purpose, the aperture opening value must also be input at the same time using a separate member.

3 to 5 are mechanical diagrams showing the first embodiment of the aperture control device according to the present invention, in which FIG. 3 shows the preset aperture ring in its open position, FIG. 4 shows the position at the minimum aperture diameter, and FIG. FIG. 5 shows the automatic preset position. Note that each figure is shown in a two-dimensional view for easy understanding.

The fixed ring 3 holds a mount for attaching the lens to the camera body and other lens barrels, and this fixed ring 3 is cut out between the surface 3a and the surface 3b, A preset aperture ring 1 is rotatably provided around the axis. The preset aperture ring 1 has a plurality of click grooves 1a for setting the preset aperture and a groove 1 in which the clutch pawl 7 engages.
b, 1b are provided. A spring 5 is attached to the fixed ring 3.
A click ball 4 is inserted through the groove 1a, and this click ball 4 applies a click by engaging with the groove 1a. The stopping force by the click ball 4 is set to be greater than the spring provided in the aperture value transmission member _B1 provided on the camera body side. The aperture value transmission ring 6 on the lens side is rotatable about the inner diameter of the fixed ring 3, and the protrusion 6b extends to the rear of the lens and engages with the aperture value transmission member _B1 on the main body side. The protrusion 6a of the aperture value transmitting member 6 extends between the surfaces 3a and 3b of the cutout portion of the fixed ring 3, and controls the rotation of the aperture value transmitting ring 6. A clutch pawl 7 is provided on the protrusion 6a.
The clutch pawl 7 is guided by a pin through an elongated hole 7c, and is biased by a spring (not shown) so that it can slide upward. The protrusion 7a on the upper part of the clutch pawl 7 fits into the groove 1b of the preset aperture ring 1 and functions as a relay for the preset aperture ring 1 and the aperture value transmission ring 3 to rotate together. A button 2 projecting outward from a hole in the preset throttle ring 1 abuts against the upper side of the inclined portion of the clutch pawl 7 inside.
The protrusion 7b below the clutch pawl 7 is in close contact with a fixing plate 8 attached to the fixed ring 3, and prevents the clutch pawl 7 from sliding.

Next, the operation of each member of the first embodiment of the control device according to the present invention will be explained with reference to FIGS. 3 to 5.

First, in Fig. 3, preset aperture ring 1
Since the protrusion 7a of the clutch pawl 7 fits into the groove 1b, it can rotate integrally with the aperture value transmission ring 6, but the protrusion 6a is in contact with the surface 3a in the right direction in the figure. Therefore, it can only move to the left. Even if the button 2 protruding outward from the hole of the preset aperture ring 1 is pushed in the direction of the optical axis, the protrusion 7b is in contact with the fixed plate 8, so the clutch pawl 7 cannot move downward and the button 2 cannot be moved. do not have.

Now, when the preset aperture ring 1 is moved to the left, the click ball 4 rotates while engaging and disengaging from the groove 1a, and the preset aperture value changes moment by moment.
The protrusion 6b is engaged with the aperture value transmitting member _B1 of the camera body, and the aperture value transmitting member _B1 is rotated to the left against the spring on the body side to input the preset aperture value to the camera body. When the preset aperture ring 1 reaches the minimum aperture value, the protrusion 6a comes into contact with the surface 3b,
The rotation in the left direction is stopped and the state shown in FIG. 4 is reached.

FIG. 4 shows a state in which the aperture is preset to the minimum aperture position. In FIG. 4, when the button 2 is pushed in, the protrusion 7b of the clutch pawl 7 is located at the notch 8a of the fixing plate 8, so that the protrusion 7a of the clutch pawl can be removed from the groove 1b. When button 2 is pressed, clutch pawl 7 is pushed down against a spring (not shown), and before projection 7a finishes separating from groove 1b, projection 7b engages with notch 8a, so that the aperture value transmission member _B1 is Even if the aperture value transmission ring 6 receives a force in the right direction due to the spring, or even if it receives force in either the left or right direction from a hand or the like when the lens is alone, the aperture value transmission ring 6 will not move by fitting either of them. It is at the position of the smallest aperture.

Even if you try to move the preset aperture ring 1 to the right (opening direction) while pressing button 2, the protrusion 7
Even if the right end surface of the groove 1b is disengaged from the right end surface of the groove 1b, the respective left end surfaces are in contact with each other, and the projection 7b
Since the cutout portion 8a is engaged with the cutout portion 8a, it cannot be moved.

When the preset aperture ring 1 is further rotated to the left while pressing the button 2, the protrusion 7a is disengaged from the groove 1b, the aperture value transmission ring 6 remains stationary, and only the preset aperture ring 1 and the button 2 move. The button 2 abuts against the right end surface of the protrusion 7a and stops.

The rotation of the preset aperture ring 1 causes the upper slope of the clutch pawl 7 and the lower part of the button 2 to slide, causing the clutch pawl 7 to further slide by the amount of the slope. Instead of the clutch button 2, it may come into contact with the right end surface of another groove 1b.

When you release your hand from the clutch button 2, the clutch pawl 7 slides upward due to the spring, and the protrusion 7a
Since the right groove 1b and the left groove 1b engage shallowly by the upper slope of the clutch pawl 7, the protrusion 7a
The engagement between the notch 8a and the aperture value transmission ring 6 is not released.
does not move from the minimum aperture position, as shown in FIG.

In Fig. 5, even if you try to turn the preset aperture ring 1 to the left or right without pressing the button 2, the protrusion 7
b is engaged with the notch 8a, so it cannot be rotated. Furthermore, although the vertical movement (axial direction) of the clutch pawl 7 is varied by the slope of the surface of the upper part of the clutch pawl 7 that contacts the button 2, the axial depth of the groove 1b on the right side can be made shallower. You can achieve the same effect.

6 to 8 are mechanical diagrams showing a second embodiment of the aperture control device according to the present invention, in which FIG. 6 shows the preset aperture ring in its open position, and FIG. 7 shows the position at the minimum aperture diameter. , FIG. 8 shows the situation at the automatic preset position.

A groove 3c is provided at a position corresponding to when the button 2 comes to the automatic preset position among the surfaces 3a to 3b of the cutout portion of the fixed ring 3.

A plate 9 is screwed inside the button 2 and is provided so as to be movable in the axial direction. Pin 9 on plate 9
a, a bent portion 9b is provided, and a protrusion 9c corresponding to the protrusion 7a of the first embodiment is provided at the lower part. The pin 9a is inserted into a long hole 7c of a clutch lever 7 which is pivotally supported by a protrusion 6a of the aperture value transmission ring 6. The cut portion 9b is the groove 3 of the notch of the fixed ring 3.
It is provided to engage with c.

The clutch lever 7 engages with a notched groove 1b of the preset throttle ring 1. At this time, the button 2 is not in contact with the inner diameter of the preset aperture ring 1, but is positioned by the engagement between the pin 9a and the elongated hole 7c of the clutch lever 7.

Next, the operation of the second embodiment described above will be explained.

In FIG. 6, the preset aperture ring 1 is rotatable only in the left direction (in the aperture direction).

At this time, even if you try to press button 2, the protrusion 9
Since c hits the fixed plate 8, it cannot be pushed.
Move the preset aperture ring 1 to the left and click the ball 4.
When the protrusion 9a is rotated while being engaged with the groove 1a, the protrusion 9a comes into contact with the surface 3b at the minimum aperture stop position in the manual preset range and stops, resulting in the state shown in FIG. 7.

In FIG. 7, since the protrusion 9c is located at the notch 8a of the fixing plate 8, when the button 2 is pressed, the pin 9a is engaged with the elongated hole 7c of the lever 7.
The lever 7 and the plate 9 are in the state shown by the chain line in FIG. 7 because the lever 7 and the plate 9 abut against the protrusion 6a and are limited in their pushing stroke.

In this way, the groove 1b and the pawl 7a of the clutch lever 7
However, since the tip of the lever 7 and the preset aperture ring 1 are still engaged, rotating the preset aperture ring 1 to the right while pressing the button 2 will cause the protrusion 9c on the lower end of the plate 9 to rotate. This is not possible because the and the notch in the fixing plate 8 will hit each other.

When the preset aperture ring 1 is rotated to the left while pressing the button 2, the button 2 and the plate 9 are rotated together with the preset aperture ring 1. The pin 9a of the plate 9 is guided to the elongated hole 7c of the lever 7, and the protrusion 9c is cut. Rotate until it comes into contact with the notch 8a. The notch 8a differs from the first embodiment described above in that the range of the notch portion is wide. If you release button 2 at this point,
It will look like Figure 8.

In FIG. 8, the portion of the preset aperture ring 1 where the tip of the lever 7 engages is deeply cut out, so that the button 2 protrudes further than in the state shown in FIG. Since this portion can move more in the axial direction, the bent portion 9b of the plate 9 and the groove 3c of the fixed ring 3 engage, and the preset aperture ring 1 cannot be rotated unless the button 2 is pressed. Can not. Further, even if the aperture value transmission member 6b on the camera body side is applied with force by a spring or by hand, the notch 1b and the claw 7a of the lever 7 are engaged, so rotation will not occur. Can not.

As explained in detail above, according to the present invention,
In the aperture control device of a multi-mode camera, it is now easier to switch between modes, and it is now easier to determine which mode the device is in from the outside, resulting in significantly improved operability.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the switching operation of each mode of a multi-mode camera, FIG. 2 is a perspective view showing the overall configuration of a camera using an aperture control device according to the present invention, FIGS. 3 and 4 , FIG. 5 is a mechanical diagram showing a first embodiment of the aperture control device according to the present invention, and FIG. 3 shows the preset aperture ring in the open position and the fourth
The figure shows the position of the minimum aperture aperture, Figure 5 shows the state at the automatic preset position, and Figures 6, 7, and 8 show the second position of the aperture control device according to the present invention.
Fig. 6 shows the preset aperture ring in its open position, Fig. 7 shows it in its minimum aperture diameter position, and Fig. 8 shows it in its automatic preset position. 1... Preset aperture ring, 1a... Click groove, 1
b...Engagement groove, 2...Clutch button, 3...Fixing ring,
4...Click ball, 5...Click spring, 6...Aperture value transmission ring, 6a...Protrusion, 7...Clutch pawl, 7a
...Protrusion, 8...Fixing plate, 10...Lens, 11...Automatic aperture lever, 12...Distance ring, 20...Camera body, 21...Aperture lever, 22...Shutter dial, 23...Rewind knob, B ₁ ... Aperture value transmission member, B ₂
...Signal piece.

Claims (1)

[Scope of Claims] 1. An aperture control device for an interchangeable lens capable of selecting a manual preset range used in aperture priority mode and an automatic preset position used in shutter priority mode and preset shutter mode,
a preset aperture ring having a signal piece that inputs to a photometric circuit on the camera side that the camera is at an automatic preset position when the aperture moves beyond the maximum aperture value; and a preset aperture ring that rotates as a result of the aperture ring and engages with a transmission member on the camera side. an aperture value transmission member for inputting a preset aperture value to a photometry circuit on the camera side; and an aperture value transmission member supported by the aperture value transmission member in a direction to engage with the preset aperture ring, and coupled at a first position. Sometimes, the assembly of the preset aperture ring and the aperture value transmission member is moved relative to the fixed member of the lens in the range from the minimum aperture value to the maximum aperture value, and when the aperture value transmission member is at the maximum aperture value and when the aperture value transmission member is at the maximum aperture value, and when the aperture value transmission member is at the maximum aperture value, Only when the preset aperture ring moves beyond the value and is in the automatic preset position, the coupling is released by operation of an external operating member from the preset aperture ring, and the preset aperture ring is moved to the automatic preset position or the preset aperture ring is moved to the maximum position. An aperture control device for an interchangeable lens comprising a clutch mechanism that allows movement to an aperture value and coupling to the aperture value transmission member. 2. The diaphragm control device for an interchangeable lens according to claim 1, wherein the external operating member of the clutch mechanism has different heights between the manual preset range and the automatic preset position.