JPH0258609B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blade support structure for a focal plane shutter, and more particularly to an improvement in a support structure for a slit-forming blade which is pivotally held on a rotating auxiliary blade.

For example, a blade actuating device for a focal plane shutter is generally known in which a plurality of divided shutter blades are rotated or rotated in parallel by a pair of parallel rods in order to cover an aperture.

The slit-forming blades are supported at the tips of two rotating parallel rods by means of a mechanism, and the rotation of the parallel rods causes the slit-forming blades to rotate and move in parallel. The rotation simultaneously rotates the auxiliary blades.

However, such a parallel rod type is undesirable because the parallel rods are essential and the structure is complicated.

Therefore, the applicant first devised a new type of vane actuator that took this drawback into consideration, and
Application for utility model registration dated September 20, 1954.
No. 130844; Utility Model No. 56-47523).

The content of this invention is that the slit forming blade is supported by an auxiliary blade, and when the auxiliary blade is rotated by an operating member, the slit forming blade is activated.

By adopting the above-mentioned structure, the parallel rods can be omitted, so the structure is simplified, but there is an inconvenience that it is difficult to obtain parallelism of the slit-forming blades.

The present invention has been made to improve this disadvantage, and provides a blade support structure that allows the slit-forming blades to always maintain parallel running.

The above-mentioned conventional example will be briefly explained below.

First, FIG. 1 is a plan view showing only the configuration of the leading blade group. In the figure, 1 is a lower shutter plate in which an aperture 1a is formed. 2 is a slit forming blade having a slit forming surface 2a;
Reference numerals 3, 4, 5, and 6 are auxiliary blades, which constitute a leading blade group.

The auxiliary blades 3, 4, 5, and 6 have cam slots 3a, 4a, 5a, and 6a formed therein, respectively, and are rotatably supported by a shaft 7 set on the shutter plate 1. In addition, the cam slots 3a, 4a
The shape is such that when the auxiliary blades 3 and 4 are rotated by a slot pin 8a, which will be described later, the slit forming blade 2 can move parallel to the edge of the aperture 1a.

The slit forming blade 2 is connected to the auxiliary blade 4 on the one hand.
The tip 4b of the auxiliary blade 3 is supported by a pin 3b which is set up at the tip of the auxiliary blade 3, and the groove 2b is fitted into the pin 3b.

8 is a leading blade operating lever, which is connected to the cam slot 3.
A slot pin 8a is installed at the tip so as to fit into the shutter plate 1.
It is rotatably supported on a shaft 9 which is installed on the shaft.

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

First, in the shutter set state shown in FIG. 1, when the operating lever 8 is rotated to the left by a drive device (not shown) in conjunction with the operation of the release button on the camera side, the slot pin 8a moves into the cam slot 3a, 4a, 5a,
Each auxiliary blade 3, 4, 5, 6 is rotated to the left while sliding on 6a. Although the operating angle of each of the auxiliary blades 3, 4, 5, and 6 differs depending on the shape of each cam slot, the auxiliary blades 3 and 4 are arranged so that the slit forming surface 2a of the slit forming blade 2 is parallel to the edge of the aperture 1a. Turn in such a way that you can maintain the The auxiliary blades 3, 4,
5 and 6, and in particular, the auxiliary blades 3 and 4, the slit-forming blade 2 opens the aperture 1a while making a parallel-rotational movement in conjunction. Then, the rotation of the actuating lever 8 is stopped in a state in which the leading blade group is folded above the aperture 1a as shown in FIG.

Next, the structure and operation of the conventional example including the rear blade group will be explained based on FIG.

Although FIG. 1 shows only the leading blade group for convenience to simplify the drawing, the shutter is actually constructed including the trailing blade group as shown in FIG. 2.

The configuration of the rear blade group is the same as that of the front blade group and is arranged symmetrically, so a detailed explanation will be omitted, but 12 is a slit forming blade, and the slit forming surface 12a is It is formed. 13, 14, 15, 16 are auxiliary blades,
13a, 14a, 15a, 16a are cam slots, 13b, 14b are support pins for the slit forming blade 12, 17 is a shaft, 18 is an operating lever, 18a is a slot pin, and 19 is a shaft. Furthermore, a partition plate 20 separates the leading blade group and the trailing blade group, and a window 20a corresponding to the aperture 1a is formed. Therefore, the leading blade group operates between the lower shutter plate 1 and the partition plate 20, and the trailing blade group operates between the partition plate 20.
Collision between the leading blade group and the trailing blade group can be avoided by operating between the leading blade group and the upper shutter plate (cover plate) (not shown).

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

FIG. 2 shows the state before the shutter is set, with the leading blade group folded above the aperture 1a, and the trailing blade group expanded to cover the aperture 1a.

When the shutter setting operation is performed in this state, the leading blade group is expanded by right rotation of the operating lever 8, and covers the aperture 1a (FIG. 1). At the same time, the rear blade group is folded under the aperture by turning the operating lever 18 to the right.

When the release button is operated from the shutter set state, the leading blade group is folded above the aperture 1a, opening the aperture 1a, and after a proper time has elapsed, the trailing blade group is opened as shown in Fig. 2. It is expanded to cover the aperture 1a, and one shooting session is completed.

The above is an explanation of the configuration and operation of the conventional example, but if the slit forming blade is supported at two points on the two auxiliary blades as described above, the slit forming blade is attached to the edge of the aperture. This is undesirable because it has the disadvantage that it cannot run in parallel, resulting in uneven exposure.

That is, if the blade actuator is of a type in which the auxiliary blades are rotated in relation to a pin and a cam slot, the slit forming blades tend to be inclined when the shutter is set. This will be explained with reference to FIG. In addition, in FIG. 3, in order to simplify the drawing, auxiliary blades unnecessary for the explanation are omitted, and
Main parts are slightly exaggerated.

In FIG. 3, when the actuating lever 8 is rotated to the right by a member (not shown) from the overlapping state of the leading blade group at the top of the drawing, the slot pin 8a is inserted into the lower cam surface of the cam slot 3a, 4a of each of the auxiliary blades 3, 4. The operating lever 8 comes into contact with a stopper (not shown) formed on the shutter plate 1 and is stopped.

Cam slot 3a of auxiliary blade 3 and operating lever 8
Generally, a gap with a predetermined tolerance is formed between the lever and the slot pin 8a to enable smooth sliding, or to take into account manufacturing errors and ease of assembly. Due to its own weight, it is pushed downward to close the gap, and the cam surface 3a' of the cam slot 3a of the auxiliary vane 3 comes into contact with the slot pin 8a of the operating lever 8.

On the other hand, the auxiliary blade 4 holds the tip side (the right end side in FIG. 3) of the slit forming blade 2, and the auxiliary blade 3
Similarly, by the setting operation, the slit forming blade 2 is rotated to the right while moving downward in the drawing along the aperture.

Generally, a thin plate is often placed close to the tip of the blade in order to stabilize the movement of the blade, especially during exposure operation.

If this thin plate is in sliding contact with the tip side of the slit-forming blade 2 and the tip side of the auxiliary blade 4, the load tends to be larger than that between the rear end side of the slit-forming blade 2 and the auxiliary blade 3, which is shorter in length. be.

When such a load difference occurs, for example, when a larger load is applied to the tip side, the slot pin 8a of the actuating lever 8 remains pressed against the lower cam surface of the cam slot 4a of the auxiliary blade 4, and After contacting the stopper and stopping clockwise rotation, if the blade stops without closing the gap between the slot 4a and the pin 8a, the auxiliary blade 4 will be deviated from the normal set position, and as shown in the figure. The rear end side of the slit forming blade 2 (the third
The left end (in the figure) is lowered by θ° compared to the tip.

As described above, since there are differences in the load on each blade and the amount of backlash formed in each support part including the shaft support, for example, this results in a difference in the setting position during the setting operation, and the difference also has a certain relationship. It is difficult to determine the value.

As a result, the exposure operation moves to the state shown in FIG. 3, the operating lever 8 turns to the left, the slot pin 8a pushes the cam surface 3a' of the cam slot 3a, and the secondary blade
When the auxiliary blade 3 rotates to the left, the auxiliary blade 3 rotates to the left, and the pin 3b, the groove 2b of the slit forming blade 2,
The auxiliary blade 4 is operated via the pin 4b.

In this state, the slot pin 8a of the operating lever 8 does not come into contact with the cam surface 4a' of the cam slot 4a of the auxiliary blade 4, and the tilted state of the slit forming blade 2 cannot be corrected, and the correct slit cannot be formed. This causes uneven exposure.

The present invention has been made in view of the above-mentioned drawbacks of the conventional example. First, even if the slit forming blades are inclined at the set position, the inclination is corrected at the same time as the start of running, so that parallel running is possible. Another object of the present invention is to provide a blade support structure in which the slit-forming blades are always in a parallel state at the set position, and the parallel state can be maintained even during travel. .

An object of the present invention is to provide a structure in which a load is applied to the slit forming blade in a direction opposite to the running direction at the same time as the slit forming blade starts traveling, so that the cam slot of two auxiliary blades supporting the slit forming blade is This is accomplished by having the cam surface contact the slotted pin.

Another object of the invention is to provide a structure in which, in addition to the above-mentioned structure, a load is applied in advance to the slit-forming blade in a direction opposite to the running direction, so as to absorb the looseness between the cam slot and the slot pin. achieved by.

The present invention will be explained below based on one embodiment shown in the drawings.

First, FIG. 4 is a plan view showing only the configuration of the leading blade group, but as explained in FIG. 2, the shutter is also configured including the omitted trailing blade group. In the case of this embodiment, unlike the configuration of the prior art example, the leading blade group is folded downward, but the present invention can be implemented in either format.

In FIG. 4, numeral 31 is a lower shutter plate in which an aperture 31a is formed. 32 is a slit forming blade having a slit forming surface 32a, and 33, 34, 35, 36, and 37 are each auxiliary blades, which together constitute a leading blade group.

The auxiliary blades 33, 35, and 36 have cam slots 33a, 34a, and 36a formed therein, respectively, and are rotatably supported by a shaft 38 set on the shutter plate 31. In addition, the cam slot 33
The shapes of a and 35a are similar to the slot pin 40 described later.
When the auxiliary blades 33, 35 are rotated by a, the slit forming blade 32 can move in parallel to the edge 31a' of the aperture 31a.

The auxiliary blade 37 also has a cam slot 37a.
, which is rotatably supported by a shaft 39 mounted on the shutter plate 31.

Further, according to a feature of the present invention, the auxiliary blade 34
is rotatably supported by the shaft 38, but a cam slot is not formed, and an escape slot 34a is formed instead.

The slit-forming blade 32 has a pin 34b at the tip of the auxiliary blade 34 near the center.
The grooves 32 are supported by the pins 33b and 35b planted at the tips of the auxiliary blades 33 and 35 near both ends of the pin 34b.
b and 32c are fitted to support the support.

40 is a leading blade operating lever, which is connected to the cam slot 3.
3a, 35a, 36a, and 37a, and the slot pin 4 is fitted loosely into the relief slot 34a.
0a is set up at the tip, and is rotatably supported by a shaft 41 set up on the shutter plate 31. Incidentally, the blade operating lever 40 is biased with a dextrorotary driving force by a spring 42, but is engaged with a locking lever 43 and is restrained.

Next, the operation of the above structure will be explained. Since the outline of the operation is as explained in FIGS. 1 and 2 above, the reason why the slit forming blades can run in parallel will be mainly explained.

First, from the set state shown in FIG. 4, when the shutter button is pressed and the locking lever 43 turns clockwise, the leading blade operating lever 40, which is released from restraint, is rotated clockwise by the spring 42. Therefore, the auxiliary blades 33, 35, 36, 37 are pushed by the slot pin 40a and rotate to the right along with the slit forming blade 32 (however, the auxiliary blade 34
moves to the right as the slit forming blade 32 moves. ), which are folded under the aperture 31a as shown in FIG. As a result, the aperture 31a is opened and exposure is started, and after the proper exposure time has elapsed, the rear blade group (not shown) moves to the aperture 31a.
From the folded state above 1a, it rotates to the right and unfolds, covering the aperture 31a and completing one exposure.

In this case, as explained above with reference to FIG. (This is as described above) As explained above, if we start from this state, the mass of the auxiliary blade 34 acts on the slit forming blade 32 via the pin 34b as an inertial force in the opposite direction to the traveling direction. Therefore, immediately after the slit forming blade 32 starts traveling, the slot pin 40
a contacts the cam surfaces of the cam slots 33a and 35a to simultaneously rotate the auxiliary blades 33 and 35 to the right, causing the slit forming blade 32 to travel in parallel.

That is, in the configuration of this embodiment, when the auxiliary blade 33 starts turning clockwise, the inertia of the auxiliary blade 34 reaches the pin 3.
At point 4b, a force acts on the slit-forming blade 32 in the direction opposite to the traveling direction, so the combination of this force and the force caused by the right-handed rotation of the auxiliary blade 33 causes the slit-forming blade 32 to move in the left-handed direction. The power of is given. As a result, the inclined state of the slit forming blades 32 is corrected and becomes parallel. For this reason, immediately after the actuation lever 40 starts turning left, the cam surface of the cam slot 35a is also aligned with the slot pin 40a.
Thereafter, the auxiliary blades 33 and 35 simultaneously rotate to the right in conjunction with the clockwise rotation of the operating lever 40, causing the slit forming blades 32 to travel in parallel as designed.

Next, another embodiment of the invention for obtaining parallel running of the slit-forming blades will be described.

In addition to the configuration of the previous embodiment, this embodiment has a structure in which a force is applied to the slit forming blades in a direction opposite to the traveling direction even in the set state, so that a parallel state can already be obtained at the set position. It is something.

In FIG. 6, 43 is a spring,
A left turning force is applied to the auxiliary blade 34.
The spring 43 is extremely weak compared to the spring 42, and does not affect the running of the leading blade group.

In this case, the spring 43 acts on the slit forming blade 32 via the auxiliary blade 34, and the auxiliary blade 33, 3
5 imparts levorotatory power. Therefore, not only in the set state but also while driving, the cam slot 33a,
Since the cam surface of 35a is in contact with the slot pin 40a, the parallel state of the slit forming blades 32 is always maintained.

In the case of the above embodiment, the slit forming blade 32 was supported on the auxiliary blade 34 and the spring 43 was mounted on this auxiliary blade 34, but the slit forming blade 32 was supported on the arm and the spring 43 was mounted on the auxiliary blade 34. It is possible to attach the spring 43 to the arm, or it is also possible to attach the spring 43 directly to the slit forming blade.

Since the present invention has the above-described configuration, the inclination of the slit-forming blades is corrected immediately after the start of travel, and the subsequent travel during exposure is performed in a parallel state, so there is an effect that uneven exposure does not occur.

Further, according to another invention in which a spring is mounted, the parallel state of the slit forming blades is maintained, so that
This has the effect of preventing uneven exposure as well as wobbling of the slit forming blades.

[Brief explanation of drawings]

Fig. 1 is a plan view of the conventional example showing only the leading blade group, Fig. 2 is a plan view illustrating the operation of Fig. 1 with the rear blade group added, and Fig. 3 shows the main parts of Fig. 1. An exaggerated plan view, FIG. 4 is a plan view of an embodiment according to the present invention, FIG. 5 is a plan view explaining the operation of FIG. 4, and FIG. 6 is a plan view of an embodiment according to another invention. It is a diagram. 32...Slit forming blades, 32b, 32c...
...Groove, 33, 34, 35, 36, 37...Auxiliary blade, 33a, 35a, 36a, 37a...Cam slot, 34a...Escape slot, 33b, 34
b, 35b... Pin, 40... Actuation lever, 40
a...Slot pin.

Claims (1)

[Scope of Claims] 1. A base plate having an aperture, an actuating member pivotally supported on the base plate and having a slot pin, and a cam slot that engages with the slot pin of the actuating member, and is interlocked with the actuating member. a plurality of first auxiliary blades that rotate as if to rotate; at least one of the first auxiliary blades is pivotally supported by two of the first auxiliary blades at a predetermined interval through a relationship between a pin and a groove; A slit-forming blade that travels by the rotation of the first auxiliary blade via the actuating member, and an escape hole that does not fit with the slot pin are formed and are held by the slit-forming blade between the pivot portions. and a second auxiliary blade that rotates in conjunction with the travel of the slit forming blade, the mass of the second auxiliary blade being opposite to the traveling direction of the slit forming blade. A blade support structure for a focal plane shutter, characterized in that it acts as a directional load. 2. A plurality of plates, each of which has a base plate provided with an aperture, an actuating member rotatably supported on the base plate and provided with a slot pin, and a cam slot that engages with the slot pin of the actuating member, and which rotates in conjunction with the actuating member. a first auxiliary vane, at least one of which is pivotally supported by two of the first auxiliary vanes at a predetermined interval through a relationship between a pin and a groove; A slit-forming blade that travels as the first auxiliary blade rotates, and an escape hole that does not fit with the slot pin are formed and are held by the slit-forming blade between the pivot parts, and the slit-forming blade A second auxiliary blade that rotates in conjunction with the travel of the blade; and a spring that has one end hung on the second auxiliary blade and acts in a direction opposite to the traveling direction of the slit-forming blade. A blade support structure for a focal plane shutter, characterized in that contact between each of the cam slots and the slot pin is always maintained via the auxiliary blade and the slit forming blade.