JPS6213067Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a focal plane shutter with a light leakage prevention structure. Specifically, the leading blade opens the aperture, the rear blade covers the aperture, and the shooting ends, and the shutter is set. The present invention relates to a structure for preventing light leakage during the setting operation of a focal plane shutter in which a leading blade covers an aperture and a trailing blade opens the aperture.

For example, in the above-mentioned focal plane shutter, the opening operation of the rear blade and the covering operation of the leading blade are generally performed at the same time during setting.

This is because the aperture must always be covered by one of the blades in order to prevent the film surface from being inadvertently exposed when the shutter is set.

However, in the focal plane shutter, the slit forming surface of the leading blade and the slit forming surface of the trailing blade must be in the same position when the shutter is set completely. This is to equalize the distance from the start position to the edge of the aperture.

On the other hand, from the viewpoint of preventing light leakage during the shutter setting operation, it is preferable that the blades operate with a large amount of overlap between the slit surfaces of the blades.

Therefore, in the conventional example, only the leading blade is moved slightly at the beginning of the shutter setting operation so that it overlaps with the trailing blade, and then the leading blade and the trailing blade are operated simultaneously while maintaining that relationship, and then the leading blade moves the aperture. A method is adopted in which the blade is first stopped in the covered state, and the rear blade is further moved slightly, and the blade is stopped when the slit surfaces become flush with each other.

The conventional configuration described above has the effect of preventing light leakage from the aperture during the shutter setting operation and making it possible to make the starting positions of the leading blade and trailing blade the same. It has the disadvantage that its structure is extremely complicated because it has to be changed in several stages.

In view of the above-mentioned drawbacks, the present invention aims to provide a light leakage prevention structure with an extremely simple configuration.

A feature of the structure of the present invention is that in the shutter setting operation, after the leading blade completely covers the aperture, the trailing blade is retracted to a position where the aperture is opened.

The present invention will be explained below based on the illustrated embodiments.

FIG. 1 shows the state before setting after photographing has been completed, with the rear blade (not shown) covering the aperture, and the leading blade in a position where the aperture is opened.

In the figure, 10 is a shutter plate whose shape is omitted. 11 is the set lever,
The shaft 1 forms a cam surface 11a, has a set pin 11b erected thereon, and is erected on the shutter plate 10.
3, and is applied with a levorotatory driving force by a spring 14, but is restrained by contacting a stopper 15. Reference numeral 16 denotes a lock lever, which has a hook portion 16a and a downwardly bent portion 16b, is supported pivotally on the shaft 13, and is biased with a dextrorotatory driving force by a spring 17. is in contact with the set lever 11 and is restrained.

Reference numeral 18 denotes a leading blade driving arm, which forms a cam surface 18a and a vertically bent portion 18b, a blade support pin 18c is installed vertically downward in the plane of the drawing, a set roller 18d is installed upward, and is installed on the shutter plate 10. The shaft 19 is supported by a shaft 19, and a dextrorotary driving force is applied by a spring 20, but is restrained by contacting a stopper (not shown). Reference numeral 21 denotes a leading blade locking lever, which forms a hook 21a, is supported by a shaft 22 mounted on the shutter plate 10, and is biased with a levorotatory driving force by a spring 23. , is restrained by a member not shown.

25 is the rear blade drive arm (first lever);
Hook 25a, arm part 25 for mirror restoration
b, forming a contact surface 25c and setting roller 25d;
is erected and supported by a shaft 26 erected on the shutter plate 10, and a dextrorotary driving force is applied by a spring 27, but it comes into contact with a stopper (not shown) and is restrained. has been done. Reference numeral 28 denotes a rear blade actuation lever (second lever), which forms a vertically bent portion 28a, through which a blade support pin 28b penetrates in the direction perpendicular to the plane of the paper and is erected, and one end is fixed to the rear blade drive arm 25. Although the levorotatory driving force is applied by a relatively weak spring 29, the blade support pin 28b
c and is restrained. Reference numeral 31 denotes a rear blade locking lever, which forms a vertically bent portion 31a, is pivotally supported by a shaft 32 mounted on the shutter plate 10, and is biased with a dextrorotatory driving force by a spring 33. However, this is suppressed by a member not shown.

Next, the operation of the configuration of the above embodiment will be explained.

When the shutter setting operation is performed from the photographing end state shown in FIG. 1, the set lever 11 is rotated to the right as shown in FIG. 2 via the set pin 11b. At the beginning of this clockwise rotation, the lock lever 16, which has been released from the restraint, similarly rotates to the right, and the hook 16a is attached to the vertically bent 28a of the rear blade operating lever 28.
engage with. By subsequently turning the set lever 11 to the right, the cam surface 11a pushes the set roller 18d to turn the leading blade drive arm 18 to the left, and the blade support pin 18c moves the leading blade to the starting position covering the aperture. Then, the leading blade drive arm 18 pushes the leading blade locking lever 21 by the vertical bending part 18b and rotates it to the right until it reaches the overcharge position shown in FIG. completely covers the aperture and charges the spring 20. Incidentally, the leading blade locking lever 21 is immediately released from its restraint in conjunction with the shutter setting operation, and returns to the state shown in FIG. 2.

On the other hand, the set roller 18d by the cam surface 11a
Simultaneously with the pushing up, the cam surface 18a of the leading blade driving arm 18 pushes the set roller 25d, causing the trailing blade driving arm 25 to rotate to the left. At this time as well, the rear blade locking lever 31, which has already been released from the restraint and rotated to the right, is pushed and rotated to the left until the overcharge position shown in FIG. 2 is reached. Spring 27 and spring 29 are therefore charged.

Subsequently, when the shutter setting force is released, as shown in FIG. 3, the set lever 11 is rotated to the left by the restoring force of the spring 14, first releasing the push up of the set roller 18d by the cam surface 11a. Therefore, the leading blade drive arm 18 is slightly rotated to the right by the amount of overcharge by the spring 20, and is locked by the leading blade locking lever 21. And the leading blade drive arm 1
8, the rear blade drive arm 25, which has been released from being pushed up by the cam surface 18a, also rotates slightly to the right by the amount of overcharge due to the spring 27, and is locked by the rear blade locking lever 31.

On the other hand, at the final stage of the set lever 11 returning to the right rotation, the lock lever 16 is interlocked and rotated to the left.
The restraint of the vertical bending 28a of the rear blade operating lever 28 by the hook 16a is released.

The rear blade operating lever 28 that is released from the restraint is moved by the spring 2
Due to the restoring force of 9, it rotates to the left as shown in Figure 4,
The pin 28b comes into contact with the surface 25c of the rear blade drive arm 25 and stops. By turning the rear blade actuating lever 28 to the left, the rear blade is actuated via the blade support pin 28b to the start position for opening the aperture.

The shutter setting operation is completed by the completion of the above operations, and the shutter is opened and closed by the next shutter release operation.

First, the leading blade locking lever 21 is rotated to the right by the shutter release, and the leading blade drive arm 18, which is released from the restraint, is rotated to the right by the restoring force of the spring 20 to operate the leading blade. Open the aperture.

Thereafter, when the appropriate time has elapsed, the trailing blade locking lever 31 is rotated to the left, and the released trailing blade drive arm 25 is rotated to the right together with the trailing blade operating lever 28 by the restoring force of the spring 27. Then, the rear blade is operated to cover the aperture, and one photographing operation is completed. Then, the system waits in the state shown in FIG. 1 until the next shutter setting operation is performed.

Since the present invention has the above-mentioned configuration, it is possible to sufficiently prevent light leakage during the setting operation of the focal plane shutter, and the configuration is extremely simple as it is only necessary to shift the operating timing of the leading blade and trailing blade. There is an effect. Furthermore, since the locking member is out of the operating trajectory of the trailing blade operating member when the cover is operated, it does not adversely affect the cover operation.

[Brief explanation of the drawing]

Figure 1 is a plan view of an embodiment of the present invention, Figure 2 is a plan view of an embodiment of the present invention;
3, 4 are explanatory diagrams of the operation of FIG. 1. 11... Set lever, 16, 116... Lock lever, 18... Lead blade drive arm, 18c...
...Blade support pin, 25...Rear blade drive arm, 2
8... Rear blade operating lever, 28b... Blade support pin.

Claims (1)

[Claims for Utility Model Registration] A leading blade driving member that operates the leading blade to a position where the aperture is opened and a position where the aperture is covered, and which is given an operating habit in the opening direction, and a trailing blade that is placed in a position that covers the aperture. a rear blade actuating member configured to be actuated to the opening position and the opening position, and to be given an actuation habit in the opening direction; actuation behavior from the second position to the second position, the actuation actuating the rear blade via the rear blade actuating member from the aperture opening position to the aperture covering position, and from the second position to the first position.
A trailing blade driving member that charges the trailing blade driving member with an operating habit by operating toward the position; and a leading blade driving member that is locked at a position where the leading blade covers the aperture, and is interlocked with shutter release operation. a leading blade locking member that releases the lock; a trailing blade locking member that locks the trailing blade drive member in a first position and releases the lock upon generation of a shutter cover signal; The rear blade operating member is provided with a locking member that has an operating behavior in a direction that allows the rear blade to lock at a position where it covers the aperture, and a locking member that is capable of reciprocating movement by setting and releasing the operation. Then, the locking member is released from the restraint, and the locking member is moved forward to a locking position with respect to the trailing blade actuating member according to its operating behavior, and the leading blade driving member is locked with the leading blade locking member by the subsequent forward movement. At the same time, the trailing blade driving member is moved to the first position where it is locked by the trailing blade locking member, and at the end of the return movement, the lock lever is moved to the position where the leading blade covers the aperture. A light leakage prevention structure for a focal plane shutter, comprising: a set member that moves the blade actuating member back and forth against its habit to a position where it cannot be locked;