JPS623787Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a camera aperture device, and in particular, after the aperture blades are narrowed from a fully open position to a predetermined position by a member that moves back and forth in conjunction with the camera release operation, they are fully opened again. This invention relates to an automatic diaphragm mechanism that returns to its original position.

Conventional aperture devices of this type generally have a complicated structure, and it takes time to fix the aperture diameter after the above-mentioned member starts forward movement, resulting in problems such as a narrow setting range of the aperture diameter. It was hot.

The present invention has been made for the purpose of providing a diaphragm mechanism with a novel configuration suitable for automatic control, which does not have the above-mentioned drawbacks.

The present invention will be explained below with reference to drawings showing an embodiment of the present invention implemented in a single-lens reflex camera.

Fig. 1 is a plan view of a single-lens reflex camera in which the present invention is implemented, in which 1 is the camera body, 2 is the photographing lens system, 3 is the right side wall of the mirror box, and M ₁
is a diaphragm mechanism provided on the outer surface of the right side wall of the mirror box, and _M2 is provided in a direction perpendicular to the diaphragm mechanism _M1 , and is operationally related to this (as will be described later). This is an aperture adjustment mechanism.

FIG. 2 shows the aperture stop mechanism _M1 viewed from the direction of arrow A in FIG. 1 in a state where the camera release button (not shown) has not been pressed (inactive state). 4 is connected to the wall surface 3 by the shaft 5.
With the set lever pivoted on the top, the two arms 4a,
4b, and a fixing pin 4c.

The set lever 4 is biased counterclockwise by a spring 6, and the tip of the arm 4a is pressed against the set pin 7. The set pin 7 is directly or indirectly related to the operation of the camera's release button, starts from the position shown in the figure, moves forward a certain distance in the direction of the arrow, and then reverses and returns in response to a shutter close signal or a mirror up signal. It is designed to move and stop at the position shown. 8 is an aperture lever pivotally supported on the wall surface 3 by a shaft 9;
a, a spring hook (pin) 8b, and a connecting pin 8c. The spring 10 biases the aperture lever 8 in a counterclockwise direction.

Reference numeral 11 denotes an aperture opening lever pivotally supported on the shaft 9, which includes a bent portion 11a and two arms 11b and 11.
It has c. The arm 11 of the aperture opening lever 11
A spring 12, which is stronger than the spring 10, is stretched between the aperture lever 8 and the aperture lever 8.

Reference numeral 13 designates a stopper for regulating the clockwise rotation position of the aperture lever 8, and reference numeral 14 designates an operating stick for the aperture ring which is biased in the direction of the arrow by a spring (not shown). The spring biases the aperture blades (not shown) in the direction of closing.

In the illustrated non-operating state, the tension of the springs 10 and 12 causes the aperture opening lever 11 to
The arm 11b is pressed against the pin 4c of the set lever 4, and the aperture lever 8 is pressed against the pin 13. At this time, aperture lever 8 and aperture release lever 1
There is a gap d between the aperture ring and the bent portion 11a of the aperture ring, and the operating rod 14 of the aperture ring is pressed against the upright portion 8a of the aperture lever 8 by the tension of the spring 12.

FIG. 3 shows the diaphragm adjustment mechanism M ₂ in the same state as in FIG.
It is a figure seen from the direction of.

Reference numeral 21 denotes a fan-shaped gear pivotally supported on a fixed part (not shown) by a shaft 22, which is connected to the connecting pin 8c of the aperture lever 8.
It has two prongs 21a that sandwich the two. (The aperture lever 8 and the sector gear 21 are always connected.) A first gear 23 is designed to mesh with the sector gear 21, and has a brush 23a fixed to its back surface.

The brush 23a slides on the resistor 24 provided on the fixed part by the rotation of the sector gear 21.

25 is a ratchet gear. The ratchet gear 25 connects to the sector gear 24 via a connecting gear.
It is connected to and rotates in conjunction with it. 26 is an electromagnet provided in the fixed part. The electromagnet 26 is controlled by a control circuit (not shown) including a variable resistance made up of the brush 23a and the resistor 24.

Reference numeral 27 denotes a locking lever that is pivotally supported on the fixed portion by a shaft 28, and has a pawl 27a for locking the ratchet gear 25 and an engaging portion 27b. Reference numeral 29 denotes an iron piece provided on the locking lever 27 so as to face the electromagnet 26. 30 is a spring that biases the locking lever 27 in a counterclockwise direction. 31
is a crimping lever pivotally supported on the fixing part by the shaft 28, and has a convex part 31a that comes into contact with the set lever 4. A spring 32 stronger than the spring 30 is stretched between the pressure lever 31 and the locking lever 27. A release lever 33 is pivotally supported on the crimp lever 31 by a shaft 34, and has an arm portion 33a and a convex portion 33b. The release lever 33 is biased clockwise by a spring 35. The force of the spring 35 is weaker than the force of the spring 30 and the force of the spring 32. Reference numeral 36 denotes a fixing pin that restricts the (clockwise) position of the release lever 33.

As shown in the figure, in the non-actuated state, the crimp lever 31 is pushed down by the arm 4b of the set lever 4, creating a gap d' between the engaging portion 27b of the locking lever 27 and the crimp lever 31. Also, since the tension of the spring 32 is greater than that of the spring 30, the claw portion 27a of the locking lever 27 is in a position where it does not engage with the ratchet gear 25.

Next, the movements of the above-mentioned parts in the operating state will be explained.

As mentioned above, when the release button of the camera is operated, the set pin 7 moves in the direction of the arrow, and the set lever 4 starts to turn left accordingly, but at the same time, the electromagnet 26 is energized by the control circuit and the iron piece 2
9 is held by suction.

The first left rotation of the set lever 4 (the arm 4b of the set lever 4 moves in the direction of the arrow in FIG. 3) causes the locking lever 2 to move (by the action of the spring 32).
When the gap d' between 7 and the crimp lever 31 disappears, the arm 4b separates from the protrusion 31a of the crimp lever 31, and when the electromagnet 26 is demagnetized, the locking lever 27 immediately rotates to the left due to the tension of the spring 30. The ratchet gear 25 is now ready to be locked. Also, in parallel with the above, in the same manner as above, the gap d between the aperture lever 8 and the aperture release lever 11 in FIG. 2 is first eliminated (because the force that pushes the aperture lever 8 upward in the figure is lost) Thereafter, the aperture lever 8 and the aperture opening lever 11 are integrally rotated to the left by the tension of the spring 10. Due to this left rotation, the vertical portion 8a of the aperture lever 8 moves upward in FIG.
follows the vertical portion and moves integrally, and the aperture blades close.

The movement of the aperture lever 8 (therefore, the connecting pin 8c) rotates the first gear 23 via the fan-shaped gear 21, thereby causing the brush 23a to slide on the resistor 24. That is, the aperture diameter of the aperture and the change in resistance value of the variable resistor correspond to each other in a 1:1 ratio. When the resistance value reaches a predetermined value (this predetermined value may be preset by the photographer or automatically determined depending on the brightness of the subject), the control circuit When the electromagnet 26 is de-energized, the locking lever 27 is released and rotated to the left by the spring 30 to lock the ratchet gear 25.

Due to the above locking, each gear and lever 8 and 11
The operating rod 14 of the aperture ring stops and the aperture diameter is determined (according to the movement of the set pin 7), but the set lever 4 continues to rotate to the left, and at the end of the left rotation, its arm 4b touches the convex portion 33b of the release lever 33. The release lever 33 is only rotated to the left against the biasing force of the spring 35, and the locking lever 27 continues to lock the ratchet gear 25. . Normally, the mirror rises at the same time as the aperture blades start narrowing down, and the shutter blades begin to open immediately thereafter.

When the shutter blade further closes, the set pin 7 moves in the opposite direction in response to the signal received by a mechanism (not shown). As a result of this movement, when the set lever 4 rotates to the right, its arm 4b immediately contacts the convex portion 33b of the release lever 33 and pushes the release lever 33.
The arm 33a of the release lever 33 is blocked by a fixing pin and cannot be rotated clockwise, so the crimping lever 31 and the locking lever 27 are
It is rotated to the right against tensions of 0 and 32, and the locking of the ratchet gear 25 by the locking lever 27 is released. The arm 4b of the set lever continues to hold the surface 33 of the convex portion 33b of the release lever 33 for a while.
b', but just before the set pin 7 reaches the position in Fig. 2, the arm 33a contacts the fixing pin 36 and rotates to the left, so the arm 4b comes off the surface 33b' (Fig. 6). , the pressure lever 31 rotates to the left due to the tension of the spring 32. During the counterclockwise rotation, the arm 4b of the set lever 4 has already reached the third illustrated position, so that the locking lever 27 and the ratchet gear 25 do not engage with each other.

On the other hand, when the set lever 4 is rotated to the right, the arm 11b is pushed by the pin 4c, so that the aperture opening lever 11 is rotated to the right, and the opening lever 11 and the spring 1
The aperture lever 8 connected by 2 also rotates to the right integrally with this. Of course, the locking of the ratchet gear 25 by the locking lever 27 is released before the right turning force acts on the aperture lever 8. By turning the aperture lever 8 to the right, the operating rod 14 of the aperture ring is pushed in the opposite direction, and the aperture blades are opened.

Even after the right rotation of the aperture lever 8 is prevented by the stopper 13 and the opening of the aperture blades is completed, the set lever 4 is pushed a little further and the set pin 7 returns to its original position (Figs. 2 and 3). , one aperture driving operation is completed.

As explained above, the mechanism of the present invention is capable of automatically setting the aperture aperture at a predetermined position by a member that reciprocates over a certain range in relation to the operation of the camera's release button. Of course, the aperture operation can be performed automatically, but in addition to its relatively simple structure, the latch gear 25 can be locked immediately after the set lever 4 starts moving, so the aperture value can be adjusted. This has many advantages, such as a wide setting range and a small load force required to move the set pin 7 backward.

It goes without saying that the technical scope of the present invention is not limited to the embodiments.

For example, the aperture lever 8 and the aperture release lever 11
can be made into a single lever if the maximum aperture aperture does not differ depending on the photographic lens system, or the function of the spring 10 can be replaced by the aforementioned spring (not shown) that biases the operating rod 14 of the aperture ring. It is also possible to serve as both.

This also applies to the shape of each lever, etc. For example, FIG. 7 shows the aperture lever 8.
This shows another embodiment of the connection between the connecting pin 8c and the two-pronged portion 21a of the sector-shaped gear 21; Top part 21 of the vertical part of the part
a', the rate of change in resistance value with respect to the aperture diameter is smoothed, and mutual adjustments can be made effectively.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the schematic arrangement when the present invention is implemented in a single-lens reflex camera, Fig. 2 is a front view of the aperture mechanism M1 in the embodiment shown in Fig. ₁ in an inoperative state, and Fig. 3 is a front view of the diaphragm adjustment mechanism M ₂ in the embodiment shown in FIG. 1 in an inoperative state; FIGS. 4 and 6 are explanatory views showing each operating state of the diaphragm adjustment mechanism M ₂ with some parts omitted; FIG. 5 is a front view of the diaphragm mechanism M ₁ after its operation, and FIG. 7 is an explanatory view showing an example of a different configuration of a part of the above embodiment. 1...Camera body, 2...Photography lens system,
3... Right wall of the mirror box, M ₁ (see 4 below)
~14)...Filtering mechanism, M ₂ (21~
36)...Aperture adjustment mechanism, 4...Set lever (aperture drive member), 5...Shaft, 6...Spring, 7...
Set pin (aperture driving member), 8... Aperture lever (aperture regulating member), 9... Shaft, 10... Spring, 11
...Aperture opening lever, 12...Spring, 13...Stopper, 14...Aperture operating rod, 21...Sector gear (connection member), 22...Shaft, 23...First gear, 23a...Brush, 24...Resistor, 25...
... Ratchet gear (locked member), 26 ... Electromagnet (holding means), 27 ... Locking lever (locking member), 28 ... Shaft, 29 ... Iron piece, 30 ... Spring, 31 ... Crimp lever (Release member), 32...
Spring, 33...Release lever (release member), 34...
...Shaft, 35...Spring, 36...Fixing pin.

Claims (1)

[Claims for Utility Model Registration] (1) A setting member 7 that moves forward over a certain period in connection with a camera release operation and moves back in that period in connection with the generation of a shutter closing signal; and said setting member 7. A diaphragm operating member 4 that engages with the diaphragm operating member 4 and reciprocates over a certain period of time; Aperture drive members 8, 11, and 14 are biased in a direction to close the aperture blades that are displaced following the forward motion; A locking member 21 to 25 provided with a displacement output stage; a locking member 27 capable of locking the locking members 21 to 25 and biased in a direction to lock the locking member 27; a holding member 26 that holds the member 27 in a non-latching position during operation; and the aperture operating member 4 restricts the movement of the locking member 27 in the locking direction at the beginning of the forward movement, and during the backward movement. It is provided with an operating part 4b that sometimes moves the locking member 27 to a non-locking position, and when the set member 7 moves forward, the aperture operating member 4 and the aperture drive member 8, 11, 1
4 moves and the aperture blades are narrowed down to a predetermined aperture value, the holding member 26 is deactivated by the signal from the displacement amount output means, and as a result, the locking member 27 moves to the locking position. The aperture value is fixed by stopping the displacement of the non-locking members 21 to 25, and the aperture operation member 4 is moved back by the return movement of the setting member 7, and the aperture value is fixed by the return movement of the setting member 7.
moves the locking member 27 to the non-locking position, and moves the aperture drive member 8, 11, 14.
An aperture mechanism for a camera, characterized in that the aperture blades are opened by returning the aperture blades to the opposite direction. (2) The aperture drive members 8, 11, and 14 have a pin 8c, and the non-locking members 21 to 25 are rotatably supported and have two prongs 21a that sandwich the pin 8c. , and the two prongs 21a are formed so that the portion that contacts the pin 8c is always the same within the movable range of the aperture drive members 8, 11, and 14. An aperture mechanism for a camera according to claim 1.