JPS6237216Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a blade type focal plane shutter.

In blade-type focal plane shutters, in order to reduce the setting force or increase the curtain speed, it is effective to reduce the area of each shutter blade and reduce its weight. Since the amount of overlap of the blades is reduced, this is disadvantageous in terms of light blocking performance. For this reason, JP-A-52-
According to Publication No. 96019, after the shutter trailing blade has finished traveling, the leading blade is returned to the picture frame, and the leading blade and trailing blade double cover the picture frame, and the trailing blade also retracts from the picture frame when the shutter is set. Similarly, both the leading and trailing blades cover the image frame twice, and in conjunction with the shutter release, the trailing blade first retreats from the image frame, and then the leading blade starts moving. A shutter has been proposed, but this has a complicated mechanism.

In view of the above-mentioned problems, the present invention aims to provide a focal plane shutter that has a simple mechanism, has the same functions as conventional ones, and has high light-shielding properties even when the amount of overlap between each blade is reduced. However, this will be explained based on the embodiment illustrated below. FIG. 1 is a schematic plan view of the shutter blade opening/closing mechanism of an embodiment of the focal plane shutter according to the present invention, and the shutter travels. This shows the later mirror-down state. FIG. 6 is a left side view of the mirror box in the state shown in FIG. 1, which is disposed on the substrate of the focal plane shutter shown in FIG. 1, and the right side is the photographing lens side.

In FIG. 1, reference numeral 1 denotes a substrate on which an aperture 1a is formed, and 2 forms arm portions 2a and 2b, on which a pin 2c is implanted and a shaft 3 fixed to the substrate 1. This is a leading blade set lever that is rotatably supported by a spring 4 and is given dextrorotation by a spring 4, and its pin 2c is connected to a leading blade set cam 3 of a shutter set gear 36, which will be described later.
6a and is restrained. Numeral 5 forms a hook portion 5a, and is pivoted to a shaft 6 fixed to the base plate 1, and is given left rotation by a spring 7, but is prevented from turning to the left by coming into contact with a stopper pin 8. The lever 9 is a hook portion 9 that can be engaged with the hook portion 5a of the first locking lever 5.
a, a vane pin 9b and a set pin 9c are implanted therein, and it is pivotally connected to a shaft 10 fixed to the base plate 1, and is given levorotation by a spring 11, so that left rotation can be prevented by a stopper pin 12. However, the set pin 9c is in contact with the arm portion 2b of the leading blade set lever 2, thereby preventing left rotation of the leading blade driving lever. The blade pin 9b is connected to a leading blade group (not shown) by well-known means, and in the state shown in FIG. 1, the leading blade group is expanded so as to cover the aperture 1a. Here, the leading blade set cam 36a, the leading blade set lever 2, the leading blade locking lever 5, and the leading blade driving lever 9.
constitutes a leading blade control member. 13 is the arm part 13
a, 13b and a pin 13c on the arm portion 13a.
The spring 1 is pivotally connected to the shaft 3.
4 imparts dextrorotation, but the right rotation is inhibited by contacting the stopper pin 15, and the pin 13c can also contact the rear blade set pin 36b of the shutter set gear 36, which will be described later. The rear blade set lever 16 forms a hook portion 16a, is pivotally connected to a shaft 17 fixed to the base plate 1, and is given left rotation by a spring 18, but left rotation is prevented by contacting a stopper pin 19. After the locking lever,
20 forms a hook portion 20a that can be engaged with the hook portion 16a of the rear locking lever 16, and a feather pin 20b;
The rear blade drive lever has a set pin 20c installed therein, is pivotally connected to a shaft 21 fixed to the base plate 1, and is given left-handed rotation by a spring 22, but the left-handed rotation is prevented by a stopper pin 23. The blade pin 20b is connected to a rear blade group (not shown) by well-known means, and in the state shown in FIG. 1, the rear blade group is expanded so as to cover the aperture 1a. Here, the rear blade set pin 36b, the rear blade set lever 13, the rear lock lever 16, and the rear blade drive lever 20 constitute a rear blade control member. Furthermore, in FIG. 6, 31 is a side plate of the mirror box in which an escape groove 31a is formed, 32 is a bottom plate of the mirror box, 33 is a motor fixed to the lower surface of the bottom plate 32 and rotates a pinion 34, and 35 is fixed to the base plate 31. 36 is an arc-shaped leading blade set cam 36a, which is pivotally connected to each shaft, and whose input side gear is meshed with a pinion 34.
A shutter set gear 38 has a rear blade set pin 36b implanted therein, is pivotally connected to a shaft 37 fixed to the side plate 31, and is meshed with the output side gear of the gear train 35; Connecting pin 38
The shutter set gear 36 and the mirror drive gear 38 have the same number of teeth. Note that the shutter set gear 36 and the mirror drive gear 38 each change to 1/1 when the mirror is up.
The rotation of the motor 33 is controlled so that it rotates twice, rotates 1/2 when the mirror is down, and rotates once during one photographing operation. Further, the motor 33 may be replaced with another driving source. 40 is a connecting plate 41 whose one end is pivotally connected to a connecting pin 38a and the other end is pivotally connected to a connecting pin 41a of a mirror 41, which will be described later.
The connecting pin 41a is installed and the side plate 31
In the state shown in FIG. 6, the mirror 41 is in the down position and reflects the photographing light that passes through the photographic lens and guides it to the viewfinder.

Since the focal plane shutter according to the present invention is constructed as described above, first of all, it is shown in Fig. 1 (Fig. 6).
When the shutter button is pressed in the state shown in FIG. The shutter set gear 36 is then turned to the right and the mirror drive gear 38 is turned to the left. Then, the rear blade set pin 36b is displaced upward by the clockwise rotation of the shutter set gear 36 and pushes up the pin 13c of the rear blade set lever 13, so that the rear blade set lever 13 is rotated counterclockwise against the spring 14. Then, by turning the rear blade set lever 13 to the left, the arm portion 13b is moved to the rear blade drive lever 2.
0 set pin 20c is pushed, the rear blade drive lever 20 is rotated to the right against the tension of the spring 22, and its hook portion 20a engages the rear locking lever 16.
climb over the hook portion 16a. On the other hand, as the mirror drive gear 38 turns left, the connecting pin 38a is displaced upward and pushes up the connecting plate 40, so the connecting plate 40 pushes up the connecting pin 41a of the mirror 41, causing the mirror 41 to turn left and bring it into the up state ( Figure 7). FIG. 7 shows a state in which the rear blade set pin 36b has been displaced to the top dead center, and the mirror 41
has not yet completed its rise, but the trailing blade drive lever 20 is already in the overset state (second
figure). Further, the motor 33 continues to rotate, and the shutter set gear 36 and the mirror drive gear 38 stop rotating after 1/2 rotation from the state shown in FIG. 8
figure). Also, in Fig. 8, the leading blade set cam 3
6a is displaced to the right, the restraint of the pin 2c of the leading blade set lever 2 is released, and the leading blade set lever 2 rotates to the right due to the tension of the spring 4 and returns to the opposite end of the leading blade set cam 36a. They come into contact with each other and are restrained. Therefore, the leading blade set lever 2
Since the restraint of the leading blade drive lever 9 by the arm portion 2b is released, the leading blade driving lever 9 is rotated to the left by the restoring force of the spring 11, but the hook portion 9
a is locked by the hook portion 5a of the first locking lever 5. Further, since the rear blade set pin 36b has also been displaced to the right from the top dead center, the restraint of the pin 13c of the rear blade set lever 13 is released, and the rear blade set lever 13 rotates to the right due to the tension of the spring 14 and returns to the stopper pin. 15 and is restrained. Therefore, the arm portion 13 of the rear blade set lever 13
Since the restraint of the rear blade drive lever 20 by b is released, the rear blade drive lever 20 is rotated to the left by the restoring force of the spring 22, but its hook portion 20a
is locked by the hook portion 16a of the rear locking lever 16 (FIG. 3). At this time, only the leading blade group covers the aperture 1a, and the trailing blade group is displaced to the start position.

Thereafter, when the tip locking lever 5 is turned to the right by a well-known means, the engagement between the hook portion 5a and the hook portion 9a of the tip blade drive lever 9 is released, and the disengaged tip blade drive lever 9 is released. is rotated to the left by the restoring force of the spring 11, and is stopped by coming into contact with the stopper pin 12. Therefore, the leading blade group is folded above the aperture 1a to open the aperture 1a and exposure is started (Fig. 4), but at this time, the trailing blade group is restrained at the starting position (Fig. 4).
figure).

Thereafter, when the rear locking lever 16 is turned to the right by the known means after the appropriate exposure time has elapsed, the hook portion 16a of the rear locking lever 16 and the hook portion 2 of the rear blade drive lever 20 are rotated.
The disengaged rear blade drive lever 20 is rotated to the left by the restoring force of the spring 22, and is stopped by coming into contact with the stopper pin 23. Therefore, the trailing blade group is expanded to a position covering the aperture 1a to complete one exposure (FIG. 4), but at this time the leading blade group remains open to the aperture 1a. The first locking lever 5 and the second locking lever 16 are rotated to the left by the tension of the springs 7 and 18 after being released from the lock, respectively, and return to their original positions.

As mentioned above, when the rear blade group closes the aperture 1a, the motor 33 is energized and the pinion 34 is rotated at the same timing, so that the gear train 35
The shutter set gear 36 is rotated to the right and the mirror drive gear 38 is rotated to the left. Then, as the shutter set gear 36 turns clockwise, the leading blade set cam 36a pushes up the pin 2c of the leading blade set lever 2, so that the leading blade set lever 2 is turned counterclockwise against the spring 4. When the leading blade set lever 2 is rotated counterclockwise, its arm 2b pushes the set pin 9c of the leading blade drive lever 9, so that the leading blade drive lever 9 is rotated clockwise against the tension of the spring 11 (Fig. 5). ). or,
The connecting pin 38a is rotated to the left by the mirror drive gear 38.
is displaced downward and pulls down the connecting plate 40, so
The connecting plate 40 pulls down the connecting pin 41a of the mirror 41 to rotate the mirror 41 to the right and lower it (9th
figure). 5 and 9 show that the shutter set gear 36 and mirror drive gear 38 are in the state shown in FIG. 8.
It is shown after 1/4 turn, the leading blade drive lever 9 is halfway set, and the mirror 41 is also halfway lowered. Further, the motor 33 continues to rotate, and the shutter set gear 36 and mirror drive gear 3
8 stops rotating after a further 1/4 rotation, the leading blade drive lever 9 returns to its original position (FIG. 1), and the mirror 41 returns to its down state (FIG. 6). At this time, both the leading blade group and the trailing blade group cover the aperture 1a.

This completes one shooting operation.

As mentioned above, in the focal plane shutter according to the present invention, both the leading blade group and the trailing blade group always cover the aperture when the mirror is down.
In addition, the up-down operation of the mirror is performed by a mirror drive mechanism equipped with a drive source that rotates in one direction, and this mechanism also causes the spring for driving the trailing blade to retract when the spring for driving the trailing blade returns to its original position. Since the structure is configured to charge the light at different times, it has a simple structure, has the same function as the conventional structure, and has the effect of providing high light-shielding properties.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of the shutter blade opening/closing mechanism of an embodiment of the focal plane shutter according to the present invention, FIGS. 2 to 5 are diagrams showing the operation progress of the shutter of the above embodiment, and FIG. The first example of the above example
Side view of the mirror box in the state shown, No. 7
9 to 9 are diagrams showing the progress of displacement of the mirror in the above embodiment. 1... Board, 2... Lead blade set lever, 5...
...Tip locking lever, 9...Tip blade drive lever, 13
... Rear blade set lever, 16 ... Rear locking lever, 20 ... Rear blade drive lever, 31 ... Mirror box side plate, 32 ... Mirror box bottom plate, 3
3...Motor, 34...Pinion, 35...Gear train, 36...Shutter set gear, 38...Mirror drive gear, 40...Connection plate, 41...Mirror.

Claims (1)

[Claim for Utility Model Registration] The leading and trailing blades of the blade type always cover the image frame except during exposure operation, but in conjunction with the shutter release, the rear blade first retracts to the starting position outside the image frame. Then, exposure is started by moving the leading blade to a position that opens the image frame, and after the proper exposure time has elapsed, the rear blade moves to a position that covers the image frame and ends the exposure. In the lens shaft, a unidirectional rotational drive source and a 1/2 rotation drive source are used.
A mirror drive mechanism comprising a mirror drive gear that rotates one rotation at a time, a connecting plate that connects the eccentric position of the mirror drive gear and the mirror, and a shutter set gear that rotates synchronously in conjunction with the mirror drive gear. a rear blade control member capable of operating a rear blade in conjunction with the shutter set gear when the mirror is in the up position, and charging a spring for operating the rear blade; and a leading blade control member that can operate the leading blade in conjunction with the camera and charge the spring for operating the leading blade, and move the trailing blade to the start position in conjunction with the upward movement of the mirror at the start of the photographing operation. The camera enters a charging state as soon as it is retracted, and enters a charging state at the same time as the leading blade is displaced to a position covering the image frame in conjunction with the downward movement of the mirror upon completion of the photographing operation. Karpurensha ivy.