JPS6220826Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of application of the invention) The invention consists of a set of shutter blades made up of a plurality of arms and a plurality of opaque thin plates, each of which constitutes a leading blade group and a trailing blade group. The present invention relates to a mechanism for braking a leading blade group and a trailing blade group immediately after the exposure operation of each of the two sets of shutter blades is completed in a focal plane shutter in which a partition plate is provided between two sets of shutter blades.

(Prior Art) Conventionally, none of these types of focal plane shutters has a stopper for braking (stopping) the leading blade group and for braking (stopping) the trailing blade group. The only ones that were seen were those equipped with a stopper for braking only the blades.

However, as the demand for faster shutter speeds and continuous shooting increases, there is a need for efficient buffering and braking (stopping) of each blade to reduce the impact on each drive member and improve durability. It has become like that.

Under these circumstances, a method of braking at the pivot point of the drive arm has come into use, but it can no longer be said to sufficiently meet the demands for even higher speed and continuous shooting in recent years.

(Purpose of the invention) In view of the above-mentioned disadvantages, the object of the present invention is to provide a mechanism for braking the so-called rear blade group of the two sets of shutter blades immediately after the exposure operation of the rear blade group is completed. .

(Structure of the invention) The object of the invention described above is to brake the leading blade group above or below the window in the gap formed between at least the partition plate and the cover plate, and to vertically extend the blade group in the height direction of the window. The spacer has a convex portion that guides the tip of the rear blade onto the collision surface of the spacer, and the spacer has a convex portion that guides the tip of the rear blade onto the collision surface of the spacer. This is achieved by being configured such that the spacer collides with the spacer.

(Embodiments of the invention) Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

Figure 1 shows a focal plane shutter in a resting state (state at the end of exposure) showing an embodiment of the present invention.
is shown with some parts omitted.

FIG. 2 is an exploded view of some of the constituent parts of the shutter shown in FIG. 1.

1 is the main plate of the shutter, which has a window 1a for mapping.

2 is a partition plate having a window 2a (the upper edge of the window 2a is
The lower edge is formed by a slope. ), and further convex part 2
b, and is formed so as to guide the rear blade to the upper surface of a vertical portion of a spacer, which will be described later, and is set obliquely with respect to the base plate 1.

Reference numeral 3 denotes a cover plate, which has a protrusion 3b that forms a space between the window 3a and the partition plate 2.

4 and 5 are blade holding plates.

Reference numerals 6, 7, 8, and 9 denote leading blade groups, each of which is made of an opaque thin plate, and whose base portion is pivotally connected to two opening operating arms (not shown) whose respective shafts are pivotally connected to the base plate; The free end side thereof is configured to run in the vertical direction in FIG. 1 in the space between the blade holding plate 5 and the partition plate 2.

The pivot point between each of the leading blades and each of the opening actuation arms, and the pivot point of the opening actuation arm to the main plate are as follows:
They are mutually positioned so as to be the four vertices of a parallelogram formed by connecting them, and each leading blade has a slit forming blade 6 forming one side of the slit at the tip end of the opening operating arm. The blades 7 to 9 are stacked on top of the slit forming blade 6 in sequence, and the blades 7 to 9 are stacked in the order in which they are stacked. A pivotally connected shaft is disposed close to the main portion of the opening actuating arm.

Therefore, each of the leading blades 6 to 9 performs a pantograph movement (parallel movement while always maintaining the same posture) with one side fixed.

Reference numerals 10, 11, 12, and 13 denote rear blade groups, each of which is made of an opaque thin plate, and its free end side runs in the space between the partition plate 2 and the blade holding plate 4, which are formed to an appropriate size. has been completed.

The trailing blade group is attached to two closing actuation arms (not shown) in an inverted configuration with respect to the leading blade group, and is therefore driven in the same manner.

In addition, in the rear blade group, the slit forming blade 13
forms the rear edge of the slit.

In addition, the above-mentioned mounting structure between the arm and the blade is as follows.
Although the number of feathers is different,
It is well known from publications such as No. 19175 and No. 54-19259.

14 is a spacer, which is approximately L-shaped.
This spacer is installed between the base plate 1 and the cover plate 3 and is made of a material such as rubber or synthetic resin that has high impact absorption performance and resilience.

14a is a vertical part, 14b is a trailing blade braking surface, which is provided at the tip of the vertical part 14a, and brakes the slit forming blade 13 of the trailing blade which has completed its movement after exposure, and 14c is a leading blade braking surface. It is an L-shaped transversely extending portion that brakes and stops the leading blade group.

In this embodiment, the spacer 14 has a long and thin shape, and is arranged in each mapping window 1a of the main plate 1 and cover plate 3.
and 3a, so as to cover almost the entire width thereof, and regulate the fixing position of the lower end of the partition plate 2. ).

Further, the spacer 14 is arranged so that the rear blade braking surface 14b of the vertical portion 14a is slightly below the lower edge of the window in the vertical relationship in the figure.

With the above structure, in the focal plane shutter of this embodiment, at the end of exposure, the rear blade groups 10 to 13 are deployed from the upper storage position with the slit forming blade 13 at the beginning. Slightly before the downward movement ends, the slit-forming blade 13 touches the rear blade braking surface 1 of the spacer 14.
4b, and the movement slowly stops.

Then, the spacer 14 is connected to the window 1 as in this embodiment.
If the slit forming blade 13 and the spacer 14 are in close contact with each other due to their biasing force and restoring force, the mapping window 2a of the partition plate 2 can be viewed from the front. Unwanted light traveling to the vicinity of the lower edge is always blocked from passing into the film.

Further, the spacer 14 is arranged between the base plate 1 and the partition plate 3, and the vertical portion 14a of the spacer 14 is
Since the trailing blade braking surface 14b is disposed at the tip of the leading blade group 6 to
Not only 9 but also the slit forming blade 13 of the rear blade group
will also be similarly buffered by the spacer 14.

Next, when the shutter charge (winding) operation is performed, the leading blade group expands upward from the first illustrated position with the slit forming blade 6 at the top, reducing the amount of mutual overlap, as if opening a fan, and On the other hand, the hind wings move upward like closing a fan and wait.

When the release operation is performed, the leading blade group converges downward with the blade 9 at the beginning and the slit forming blade 6 at the end, while the trailing blade group with the slit forming blade 13 at the beginning unfolds. Exposure is performed by moving as if chasing after each other, and the state shown in FIG. 1 is reached.

In the above, the role of the diaphragm 2 is to prevent collision between the leading blade and the trailing blade, and the reason why the diaphragm is set obliquely to the main plate 1 is to fulfill the above purpose and at the same time. This is to keep the distance between the two slit-forming blades 6 and 13 constant at all times to prevent light leakage and variations in exposure amount.
By bending the inner slit-forming blades 13 of the moving rear blade groups 10 to 13, the accident of collision with the lower edge of the mapping window 2a is made less likely to occur. In particular, the tip of the slit forming blade 13 must be pressed against the rear blade braking surface 14b of the spacer 14.
It is meant to lead you to the top.

(Other Embodiments) In the above-mentioned embodiments, the direction of travel of the blades is from top to bottom, but it is unnecessary to explain that the blades may travel from bottom to top instead. Probably not.

Further, when the vertical direction is changed by 180 degrees contrary to the embodiment, since the spacer is located above, the film is not exposed to unnecessary incident light from above the shutter, such as the viewfinder.

In addition, in the embodiment, in order to prevent unnecessary light (light leakage) from entering from the lower end of a reflecting mirror (not shown), etc., the mapping window has a length spanning the entire width direction. If the spacer is not particularly required to have the desired effect due to the method or structure described above, the width may be the minimum necessary and the arrangement position may be selected.

(Effects of the Invention) As described above, by implementing and utilizing the present invention, it is possible not only to brake the leading blade group, but also to brake the trailing blade by using the same stopper as the leading blade group. As a result, it is possible to reduce the thickness, change the material (lighten the weight), etc., and provide a focal plane shutter that is sufficiently durable to meet the high speed requirements of such focal plane shutters.

[Brief explanation of the drawing]

FIG. 1 is a side view of a focal plane shutter according to an embodiment of the present invention in a resting state, and FIG. 2 is an exploded perspective view of a portion of the embodiment. 1... Base plate, 2... Partition plate, 2a... Window section, 2b
... Convex part (rear blade guiding slope), 3 ... Covering plate, 4,
5...Blade holding plate, 6-9... Leading blade group (6...
...slit forming blade), 10-13... trailing blade group (13... slit forming blade), 14... spacer, 14a... vertical portion, 14b... trailing blade braking surface, 14c... leading blade braking surface .

Claims (1)

[Claims for Utility Model Registration] A leading blade group and a trailing blade group consisting of a plurality of arms whose main body is pivotally connected to a base plate by respective shafts, and a plurality of opaque plate blades which are pivotally connected to each of the arms. A partition plate having a group of blades and a mapping window between the leading blade group and the rear blade group is further covered on the side opposite to the main plate of the partition plate so as to sandwich the blade group located therebetween. In a focal plane shutter formed by arranging plates, at least a gap formed between the partition plate and the base plate or the cover plate has a surface above or below the window for collision braking of the leading blade, and a surface at the height of the window. A spacer is provided with a vertical portion in the direction and serves as a braking surface for the rear blade, and the partition plate is rearwardly moved onto the collision surface of the spacer so that the rear blade collides with the spacer at the end of exposure. A focal plane ivy characterized by having a convex portion that guides the tip of the blade.