JPS5916255B2 - Manual aperture device for single-lens reflex cameras with instant automatic aperture determination - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a single-lens reflex camera with automatic aperture determination, in which the aperture is manually reduced to an appropriate aperture for the set shutter speed and film sensitivity, and the image is observed and then photographed. The present invention relates to a manual narrowing device that can perform the following operations.

After setting the aperture of the interchangeable lens so that it can be narrowed down to the minimum aperture, the aperture re-preset member installed on the camera body is operated to narrow down the aperture, and the subject light passing through the aperture that is being narrowed down is captured by TTL. Measure the light,
When the aperture is narrowed down to the appropriate aperture for the shutter speed and film sensitivity set on the camera body side, the aperture control circuit that receives the photometry output operates the electromagnet, and the aperture 15 re-preset member narrows down the aperture. A single-lens reflex camera with an automatic aperture determination type that automatically determines the aperture by stopping the operation is known from Japanese Patent Laid-Open No. 48-3929. With such a single-lens reflex camera 20 camera with automatic aperture determination, any interchangeable lens already on the market can be attached to the camera body, and the aperture of the interchangeable lens can be set to the minimum aperture. It has an excellent feature that allows automatic exposure control with just a single touch, but since the aperture resetting member is used to stop down the aperture to 25, it is performed in conjunction with the release operation, so the shutter speed set on the camera body is It has the disadvantage that the image cannot be observed through an aperture that is narrowed down to an appropriate aperture for the film sensitivity and film sensitivity.

However, since the aperture affects the resolution of the image and the 30-point depth of focus, photographers have always desired to be able to observe the image after the aperture has been apertured prior to the release operation. SUMMARY OF THE INVENTION The present invention aims to provide a manual diaphragm device for a single-lens reflex camera with an automatic 35-dynamic aperture determination type as described above, which satisfies this demand. In order to provide a manual operating member that manually operates the aperture re-setting member independently of the release operation, and to operate the aperture control circuit even when the aperture pre-setting member is manually operated, the above-mentioned device that is closed by the release operation is provided. in parallel with the first power switch of the circuit,
The present invention is characterized in that a second power switch is provided which is closed by operating the manual operation member.

One embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a camera according to the above embodiment, and shows an interchangeable lens 2 that can be attached to a camera body 1.
A light-receiving element 10, such as a silicon photodiode with quick photoresponse, is arranged on the roof of the pentaprism 11 of the camera body so that TTL photometry of the light beam passing through the photographing lens 3 and diaphragm 5 can be performed. .

The diaphragm preset member 7 is controlled by operating the electromagnet 20 by the diaphragm control circuit shown in FIG. 2 which receives the output of the light receiving element 10 as an input.

When the shutter button 12 is pressed down, this aperture preset member 7 is released from its lock at the charge position and moves, and the aperture interlocking pin 6 follows this aperture re-preset member 7 to move the aperture 5.
is narrowed down. After the aperture 5 is closed, the mirror 8 is unlocked and rotated upward to release the shutter 9. As shown in FIG. 2, the aperture control circuit includes a photometric calculation circuit B including a light receiving element 10, a differential switching circuit C including an electromagnet 20, and a variable resistor set by a shutter speed dial 13 (see FIG. 1). 13a, a power supply 15, a first power switch 16 that is closed in connection with the release operation, a second switch 65 that is parallel to the power switch 16, and both switches 16, 65. and an aperture holding switch 66 inserted in series between the electromagnet 20 and the electromagnet 20.

The photometric calculation circuit B includes an operational amplifier 17 that amplifies the output of the light receiving element 10 without applying a voltage between both ends thereof;
A diode 18 is provided for photographically processing the output of the light-receiving element 10, and is configured to logarithmically compress changes in subject brightness to generate a potential difference X. A variable resistor 14a whose resistance value is determined according to the setting position of the film sensitivity setting member 14 shown in FIG. The potential of photometry calculation circuit B
occurs as the output of On the other hand, the manual setting circuit D has a variable resistor 13a in series with a diode and a current source whose resistance value is determined according to the setting position of the shutter speed dial 13,
It is configured to create a potential difference z.

The potentials x+y and z generated in these two circuits B and D are input to the differential switching circuit 19 of circuit C.

The illuminance of the light-receiving surface of the light-receiving element 10 gradually decreases due to the narrowing operation of the aperture 5 by the aperture preset member 7, and the potential y
When the potential difference between +x and potential z becomes O, the differential switching circuit 19 stops exciting the electromagnet 20 that had been excited up to that point, thereby preventing movement of the diaphragm preset member 7 as described later. That is, as shown in FIG. 1, the interchangeable lens 2 is attached to the camera body 1 by engaging the aperture interlocking pin 6 of the interchangeable lens 2 in a known manner, and the aperture ring 4 of the interchangeable lens 2 is adjusted to the minimum aperture diameter (F in the figure). 16), the aperture of the aperture 5 is not determined by the aperture ring 4 on the interchangeable lens 2 side, but is controlled by the aperture preset member 7 on the camera body side. While closing the power switch 16, the diaphragm preset member 7 is released from its charge position (open position) to close the diaphragm 5, and TTL photometry is performed in the process of closing the diaphragm 5. When the difference between x+y and z becomes O, the excitation of the electromagnet 20 is stopped, the movement of the aperture preset member 7 is stopped, and the aperture 5 is controlled to an appropriate aperture.

Figures 3 to 6 show members arranged on the outer wall of the mirror box in the same embodiment.
The figure is a side view, and FIGS. 4 and 6 are bottom views.

FIG. 7 is a bottom view of the same as above, showing a state in which the aperture is manually operated. FIGS. 3 and 4 show the shutter 1 being charged and set just before the release operation is performed.

In FIG. 4, on the bottom of the mirror box, an aperture preset member 7 is rotatably mounted on a shaft 28, which makes partial contact with the aperture interlocking pin 6 of the attached interchangeable lens. A fan-shaped gear 27 which has a clockwise rotational habit and has a claw portion 27b is pivotally mounted by 29. Here, the aperture preset member 7 has pins 7A, 7.
b is implanted, and the pin 7a engages with the notch of the fan-shaped gear 27 to prevent clockwise rotation thereof. On the other hand, the pin 7b is attached to a U-shaped groove 33 of the connecting lever 33.
It is fitted into the inside of b. The connecting lever 33 has a claw portion 33a that engages with the claw portion 27b, and is linked by a shaft 36a onto another lever 36 rotatably supported by a shaft 35 on the bottom plate of the box. There is. A spring 38 is tensioned between the other arm of the lever 36 and the arm end of the aperture preset member 7 so as to pull both arms together. 36a, lever 36, and spring 38 constitute a loop-shaped moving body. The spring 38 has a load that provides the diaphragm preset member 7 with a force that overcomes the load of the diaphragm interlocking pin 6 in the interchangeable lens. This loop-shaped moving body connects the lever 36 and the connecting lever 3 at the shaft 36a.
Due to the action of the spring 34 applied to the shafts 3 and 3, the shaft 35 has the tendency to rotate counterclockwise around the shafts 35 and 28. On the other hand, another lever 37 is rotatably supported on the shaft 35, and a spring 3 is stretched between it and the bottom plate of the box.
9 gives it counterclockwise and clockwise rotational habits. The bent portion 36b of the lever 36 is the bent portion 37b of the lever 37.
When the lever 37 rotates counterclockwise, the lever 36 rotates following the lever 37.
When the lever 37 rotates clockwise due to the action of a return lever 60, which will be described later, it is pushed by the lever 37 and rotates clockwise. However, in the set state shown in FIG. 4, since the lever 37 stops at a position rotated clockwise as described later, the lever 36 also stops at a corresponding position. The sector gear 27 meshes with a pinion 32 which is integrally supported by a ratchet gear 30 by a shaft.

To prevent rotation of the ratchet gear 30, a stop lever 22 is pivotally mounted on the shaft 24 and has a stop pawl 22a engageable with its teeth. This stop lever 2
An armature 21 that is attracted by an electromagnet 20 is disposed at the other end of the diaphragm holding switch 66.
A pin 22c for opening and closing is installed. The stop lever 22 is biased clockwise by a weak spring 26 so that the armature 21 is pressed against the electromagnet 20, and is pivoted on a shaft 24 and rotated counterclockwise by a strong spring 25. The eccentric pin 23a of the other lever 23 is engaged with the arm 22b of the stop lever 22. This lever 23 engages with one end 33c of the connecting lever 33, and in the set state shown in FIG. 4, is held in the illustrated position against the spring 25. At this time, the weak spring 26 mechanically presses the armature 21 onto the electromagnet 20, and the stop pawl 22a is retracted from the ratchet gear 30. In FIG. 3, on the side wall of the mirror box, there are a member for stopping the lever 37 described above in the set state shown in FIG. 4, and a member for slowing down the rotation of the lever 37 when the lever 37 is released. A mechanism for driving the mirror 8 and the like are provided. A pin 37a protruding from the lever 37 engages with a notch 41a of the sliding shaft 41.

The sliding shaft 41 is slidably fitted into guide holes 40a and 40b of a fixed plate 40 fixed to the side wall of the box, and in addition to the notch 41a, a locking pin 41b and an interlocking pin 4 are provided.
1c. The locking lever 42, which is supported on the fixed plate 40 by a shaft 42a, engages with the locking pin 41b in the set state, and when the sliding shaft 41 is moved to the left in FIG. In Figure 4, counterclockwise rotation is prevented.

42b is a bent piece formed on the locking lever 42.

Fork portion 44a into which the interlocking pin 41c engages
A three-pronged slow speed lever 44 is supported by a shaft 43 on the side wall of the box, and one arm of the lever 44 is connected to a cylinder 47 fixed to the side wall by a shaft 48 and a piston 46 fitted into the cylinder 47.
A pin 46a is attached to the piston 46 of the air damper.
are connected.

A mirror drive lever 45 is also pivotally supported on the shaft 43, and is provided with clockwise rotational behavior by a spring 49.
The claw 45b engages with the mirror 8.

This mirror drive lever 45 engages with the pin 41b of the slow speed lever, and the half-moon pin 45a is attached to the mirror locking lever 51 which is given a counterclockwise rotational habit around a shaft 50 by a spring 52. It is engaged in the set state. The mirror locking lever 51 has a release arm 51a with which the pin 44b engages when the slow speed lever 44 reaches the final stroke of clockwise rotation, and this engagement causes it to rebound against the spring 52. It is rotated clockwise to release the lock of the mirror drive lever 45. At this time, the lever 37 is also in its final stroke of rotation in the counterclockwise direction, and if the aperture resetting member 7 is not stopped by the stop lever 22 during rotation, the aperture 5 of the interchangeable lens has already reached its minimum aperture diameter. It has been narrowed down to The shutter release lever 53 is pivotally supported by a shaft 54, and is rotated counterclockwise by engaging the mirror drive lever 45 at the final end of clockwise rotation, thereby engaging the locking member 9a. to release the locking of the shutter 9.

The lever 56 is pivotally supported on the side wall of the box by a shaft 57, and is given a clockwise rotational tendency by a spring 58 stretched between one arm of the lever 56 and the locking lever 42.

The other arm of the lever 56 engages with the shutter button 12 and the movable contact piece of the first power switch 16, and in the set state shown in FIG. 3, the power switch 16 is open. When the release button 12 is pressed down, the spring 58
The first power switch 16 is closed by rotating it counterclockwise against the pressure. The operating lever 55, which is pivotally attached to one arm of the lever 56 by a shaft 55a, is given the habit of rotating counterclockwise with respect to the lever 56 by a spring 55b, and has a fishing portion 55d formed on its side wall. is engaged with the bent piece 42b of the locking lever 42.

The bottom surface 55c is connected to the sliding shaft 41 which moves to the left when the operating lever 55 is pushed up by the counterclockwise rotation of the lever 56 and the locking lever 42 is rotated counterclockwise.
is engaged with the locking pin 41b to hold the operating lever 55 in its raised position. A strong spring 60 is supported on the shaft 35.
When the shutter is charged, the restoring lever 60, which has a clockwise rotational habit according to a, locks the restoring lever 61.
It is locked in the position shown by one of its arms.

The other arm of the restoring locking lever 61 is engaged with a plate 9b fixed to the rear curtain shaft of the shutter 1, and when the shutter shutter 1 is released and the travel of the rear curtain shaft is completed, it engages with the protrusion 9c of the plate 9b. Therefore, the restoration lever 60 is rotated counterclockwise, and the restoration lever 60 is unlocked, and the restoration lever 60 is rotated clockwise, and the lever 37 is rotated.
is rotated clockwise against the spring 39, and the lever 36 is rotated clockwise against the spring 39.
is rotated clockwise against the spring 34 to charge the loop-shaped moving body to return to its original position. In this case, the sliding shaft 41 is also moved back via the lever 36;
The backward movement is stopped when the pin 41b engages with the right end of the guide groove of the fixed plate 40, and thereby the clockwise rotation of the loop-shaped moving body is also stopped. Although not shown, this state is a so-called overcharge state, and in the loop-shaped moving body, the aperture interlocking pin 6 on the interchangeable lens side stops at the fully open aperture position and prevents the aperture preset lever 7 from rotating clockwise. In addition, a slight gap is created between the groove portion 33b of the connecting lever 7 and the pin 7b of the aperture preset lever 7. Note that after this, the restoration lever 60 is rotated counterclockwise by the shutter charging operation, and the restoration lever 37 is rotated counterclockwise.
When the sliding shaft 41 is retracted from the position, the overcharge is released and the sliding shaft 41 moves to the left to the set position shown in FIG. 3, and the pin 41b is locked by the locking lever 42. At the same time, the loop-shaped moving body is also released from overcharging, rotates counterclockwise to the set position shown in FIG.
The groove portion 33b of No. 3 engages with the pin 7b of the aperture preset lever 7. The manual aperture operating rod 67 has a long groove 67d in which a plurality of guide pins 68 installed in the camera body are loosely fitted, and is slidable left and right in FIG. 4 and is supported by a strong spring 69.
One end 67b serves as an operation button that can protrude outside the camera housing.

Furthermore, this manual aperture operating rod 67 includes a pin 67a and a protrusion 67c that engages with the aperture preset member 7 and rotates it counterclockwise when it is pushed in the direction of arrow A against the spring 69. and has. The manual operating lever 70 has a long groove 70c into which a plurality of guide pins 71 provided approximately parallel to the guide pin 68 are loosely fitted, and is slidable left and right in FIG. It is biased to the left by a weak spring 72 so as to engage with the pin 67a.
When the manual aperture operating rod 67 is returned to the position shown in FIG.
is pushed to move the manual operating lever 70 to the right against the spring 72, and at this time, the right end piece 7 of the manual operating lever 70
0a keeps the second power switch 65 open. On the other hand, when the manual operating lever 67 is pushed in the direction of arrow A as shown in FIG. The left end bending piece 70b engages with the arm 22b of the stop lever 22. Next, the operation of this embodiment will be explained.

When the shutter 9 is in the charged state shown in FIGS. 3 and 4, when the shutter button 12 is pressed down, the third
In the figure, the lever 56 is rotated counterclockwise to close the first power switch 16 and put the circuit shown in FIG. 2 into operation. When the shirt button 12 is continuously pressed down, the operating lever 55 rotates the locking lever 42 counterclockwise due to the engagement between the fishing portion 55d and the bent piece 42b, and the locking pin 41b of the sliding shaft 41 is engaged with the operating lever 55. Release the stop.

Therefore, the sliding shaft 41 is slid to the left in FIG. 3 by the spring 39 of the lever 37 shown in FIG. 4 connected thereto. Here, the connecting pin 41c of the sliding shaft 41 is engaged with the fork portion 44a of the slow speed lever 44 on which the air dampers 46 and 47 act, so that the sliding shaft 41 moves while being controlled. However, the speed of the lever 37 and the loop-shaped moving bodies 33, 36, and 38 that follow it are also controlled, and the X-axis 35,
28 in a counterclockwise direction (see Figures 4 and 5). At this time, the claw portion 33a of the connecting lever 33 rotates the fan-shaped gear 27 counterclockwise through the claw portion 27b that engages with the claw portion 27b against the spring 29, and rotates the ratchet gear 30 via the pinion 32. Rotate it clockwise.

At the same time, by moving the end 33c of the connecting lever 33 to the left, the lever 23 tries to rotate the stop lever 22 counterclockwise by its eccentric pin 23a, but the rotation is Since the armature 21 is attracted to the electromagnet 20, this is prevented. On the other hand, the sum x+y of the output voltage x of the light-receiving element 10 that receives the light beam from the subject that has passed through the aperture 5 and the lens 3, and the voltage y generated in the variable resistor 14a set according to the film ASA sensitivity is determined manually in advance. Variable resistor 1 determined by the shutter speed set to
3a, the electromagnet 20 remains excited to maintain the above-mentioned blocking, but as the diaphragm preset member 7 rotates counterclockwise, the diaphragm 5 is gradually narrowed down and the voltage z is increased. When the relationship ζy≦z holds, the electromagnet 2
0 excitation is cut off, the stop lever 22 is rotated counterclockwise by the spring 25, and its stop pawl 22a engages with the latch 30.

As a result, the rotation of the fan-shaped gear 27 and furthermore the rotation of the aperture preset member 7 are stopped, so the narrowing operation of the aperture 5 via the aperture interlocking pin 6 is also stopped, and the aperture is automatically determined to the appropriate aperture diameter. be done. On the other hand, the lever 37, the sliding shaft 41, and the slow speed lever 44 continue to rotate, and in their final movement, the pin 44b of the slow speed lever 44 releases the release arm 51a of the mirror locking lever 51 as shown in FIG. , the mirror lock lever 51 releases the lock of the mirror drive lever 45, so the mirror drive lever 45 is rotated by the spring 49, rotates the mirror 8 to the horizontal position, and then rotates the mirror 8 to the horizontal position. In the final movement, the shutter release lever 53 is rotated counterclockwise to release the locking member 9a of the shutter 9 and release the shutter (see FIG. 5).

In this way, automatic determination of the aperture, subsequent rotation of the movable mirror, and shirt release are performed.

Note that the final movement position of the lever 37, sliding shaft 41, and slow speed lever 44 in this case is a position where the large diameter portion of the sliding shaft 41 engages with the bent portion of the fixed plate 40 having the guide hole 40a. FIG. 6 shows the state just before they reach their final movement position. If you want to take a picture after observing the next selected image, press release button 1.
When the manual diaphragm operating rod 67 is first moved to the left against the spring 69 by pressing its one end 67b without pressing the diaphragm preset member 2, the protrusion 67c comes into contact with the diaphragm preset member and pushes it against the spring 38. Press against tension.

In this way, as shown in FIG.
, 36 is blocked by the locking of the sliding shaft 41 by the locking lever 42, the aperture preset member 7
The pin 7b is rotated counterclockwise from the aperture open position while moving the pin 7b to the left within the U-shaped groove 33b of the connecting lever 33. Following this, the aperture is gradually narrowed down. At this time, the manual operating lever 70 is activated by the spring 72.
moves to the left following the manual diaphragm control rod 67 and closes the second power switch 65, so the first power switch 16 is open but the diaphragm control circuit remains in the operating state. Become. Note that the bending piece 70b comes into contact with the arm 22b of the stop lever 22 because the excited electromagnet 20 is attracting the armature 21, so the stop lever 22 does not rotate at this point. When the difference between the potentials x+y and z becomes 0 as described above by TTL photometry of the light beam that has passed through the aperture that is being narrowed down, the aperture control circuit cuts off the power to the electromagnet 20 and the armature 21 stops attracting the light. When the stop lever 22 is disconnected, the stop lever 22 rotates counterclockwise under the bias of the spring 72 and engages with the ratchet gear 30.

Therefore, the rotation of the diaphragm preset member 7 is stopped, and the appropriate aperture is determined dynamically relative to the diaphragm force, so the image at that diaphragm aperture can be observed, and if this is satisfactory, the release button 12 is pressed. Exposure can be performed by pressing down. The operation at this time is based on the aperture preset member 7.
The operation is the same as when the manual aperture operating rod 67 is not pushed in advance, except that it has already stopped and does not move. When the stop lever 22 is rotated counterclockwise, the pin 22c
opens the aperture holding switch 66 and disconnects the electromagnet 20 from the power source 15.

Therefore, during exposure, when a brightness change occurs in the subject field and the state of x+y>z is reached, the switch 66
The electromagnet 20 is energized again and the armature 21 is attracted to it, and the diaphragm preset member 7 whose ratchet gear is no longer locked by the stop lever 1 starts operating again to prevent the diaphragm aperture from changing. Incidentally, if the image obtained by the automatically determined aperture aperture is unsatisfactory for the photographer, it is sufficient to stop pressing one end 67b of the manual aperture operation rod 67.

As a result, the manual aperture operating rod 67 is returned to its original position by the spring 69, and the pin 67a is moved to the protrusion 70d of the manual lever 70.
The stop lever 22 is rotated clockwise by the spring 26 to move the armature 21 to the right against the spring 72 to the position shown in FIG.
At the same time, the stop pawl 22a is separated from the ratchet gear 30. As a result, the aperture preset member 7
The fan-shaped gear 27 is rotated clockwise by the tension of the spring 38 and the force of the spring 29, and returns to the set state shown in FIG. 4, opening the aperture via the aperture interlocking pin 6. Then, by rotating the shutter speed dial 13 of the camera again, the set shutter speed can be changed, and then the manual aperture operation lever 67 can be pushed in again.

As described above, according to the present invention, in the automatic aperture determination type single-lens reflex camera of the above type, a manual operation member for manually operating the aperture preset member is provided, and
The second power switch, which is closed by the operation of this manual operation member, is provided in parallel with the first power switch of the aperture control circuit, which is closed by the release operation, so that the aperture is automatically adjusted based on the release operation. Not only can the aperture be determined to be the appropriate aperture, but also the aperture can be determined to be the appropriate aperture by operating the manual operation member, and in the latter case, after observing the image through the determined aperture aperture, it is possible to If it is possible, you can immediately take a picture by operating the release; if you are not satisfied, change the set shutter speed and repeat operating the manual operation member until a satisfactory image is observed, and then operate the release. You can take pictures using the following. Further, according to the present invention, whether the diaphragm is automatically determined to the appropriate aperture based on the release operation or the diaphragm is determined to the appropriate aperture based on the operation of the manual operation member, a separate operation is not required. Not only is the operation itself very simple, but the diaphragm control circuit is not energized when the release or manual operation member is not operated, so power is wasted. Furthermore, the inconvenience of forgetting to close the power switch and having to restart the operation, which is the case when a separate power switch is provided, is also eliminated.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing only the main parts of an embodiment of the present invention, FIG. 2 is a circuit diagram of an aperture control circuit of the embodiment, and FIGS. 3 to 7 are a diagram of the aperture control circuit of the embodiment. The configuration arranged in the mirror box is shown, with Fig. 3 being a side view in the set state, Fig. 4 being a top and bottom view of the same, Fig. 5 being a side view of the same with the release operation being performed, and Fig. 6 being the same as the release operation being performed. FIG. 7 is a side view when the aperture is manually operated. 1... Camera body, 2... Interchangeable lens, 4... Aperture ring, 5... Aperture, 6
...Aperture interlocking pin, 7...Aperture preset member, 8...Movable mirror 9...Shutter, 9a...Shutter locking member , 10...
... Light receiving element, 12 ... Shutter button, 13
・・・．・．． Shutter speed setting member, 14...
Film sensitivity setting member, 15...Battery, 16.
...First power switch, 20... Electromagnet, 21... Armature 22... Stop prepper 22a... Stop claw, 27.
... Sector gear 30 ... Ratchet gear, 33 ... Connection lever 41 ... Sliding shaft, 42 ... Locking lever, 65 ...・・・・・・
Second power switch, 66...Aperture holding switch, 67...Manual aperture operating rod, 70...
・Aperture operation lever.

Claims (1)

[Claims] 1 When the aperture preset member disposed on the camera body side performs a stop-down operation in which the aperture is narrowed down from its open position in conjunction with the release operation, the camera performs TTL photometry on the subject light that has passed through the aperture whose aperture changes. When the aperture is narrowed down to an appropriate aperture for the shutter speed set on the main body and the film sensitivity used, the aperture control circuit that receives the photometric value as input operates an electromagnet to cause the aperture preset member to narrow down the aperture. In a single-lens reflex camera with automatic aperture determination that determines the aperture by stopping the aperture, the manual operation member manually operates the aperture presetting member regardless of the release operation, and the aperture control circuit is closed by the release operation. A manual aperture device characterized by comprising: a second power switch that is provided in parallel with the first power switch and is closed by operating the manual operation member for manually operating the aperture preset member. .