JPS5843437A - Focal plane shutter - Google Patents

Abstract

PURPOSE:To reduce the time from releasing of a camera till the starting of a front curtain by moving a mirror upward when a rear curtain resets to a start position in succession to the releasing of the camera. CONSTITUTION:When a rear curtain resets to a start position, the detention of a release lever 20 is released, and an arm 31 for operating the rear curtain is turned right by the tension of a spring 33. Therefore the rear curtain is reset to the start position; at the same time, the arm part 38a of the 1st arm 38 interlocking to the mirror is pushed by the arm 31 by which the arm 38 is turned left and its arm part 38b pushes the arm part 58b of the 1st detaining lever 58 to turn the 1st detaining lever 48 right. Thus a control lever 50 is released of detention and its bent part 52 is turned right by the tension of a spring 53 until said part abuts on a charging lever 54. In such a way the surface 50b of the lever 50 pushes a pin 48, and a mirror 48 is turned left and moved upward by overcoming the tension of a spring 46.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a double-return type focal plane shutter in which the picture frame is covered with a leading curtain and a trailing curtain before and after the shutter is set.

It operates using the conventional double-return type focal plane, returning to the leading curtain starting position, and moving the mirror down. However, the first curtain must be started after waiting approximately 70m8 for the bounce when the second curtain returns to its starting position to completely subside.
It was a huge loss of time.

Accordingly, the present invention aims to provide a double-return type focal plane shutter that shortens the time from camera release to the start of the front curtain, and will be described below with reference to embodiments shown in the drawings. FIG. 1 shows the shutter curtain opening/closing mechanism of the focal plane shutter according to the present invention after the shutter is set, and FIG. 2 shows the mirror drive mechanism at this time, where 1 is the substrate, 2 is the image frame, and 3
4 is a pillar, 4 is a front curtain drive arm which is pivotally mounted on a shaft 5, is given left-handed rotation by a gun 6, and has a pin 7 planted therein; 8 is supported on the front curtain drive arm 4 by a shaft 8a. The leading curtain actuating arm locking lever 9 has a pin 10 (not shown) for supporting the leading curtain, and forms an engaging portion 9a, and is provided with left and right rotation by a spring 8b. The leading actuating arm 12 is pivotally connected to a shaft 15 and has left rotation by a spring 19, but the left rotation is prevented by a stopper 18. The leading curtain locking lever 14 which is restrained is an X contact lever 1 which is pivotally connected to a shaft 15 and is given left rotation by a spring 16.
7 is an X contact. A release lever 124 is pivotally connected to a shaft 21 and is given dextrorotation by a spring 26, but its right rotation is prevented by a stopper 22.
A second mirror interlocking lever 27 is pivotally attached to a shaft 28 and is imparted with levorotation by a spring 26, but its left rotation is prevented by the stopper; Pin 30.

The planted rear curtain drive arm 31 supports a rear curtain (not shown) and also supports the rear curtain (not shown). Pin 62 engaging drive arm 27
64 is a rear curtain actuating arm which is pivotally connected to the shaft '28 and given dextrorotation by a spring 36;
5, and is given levorotation by a spring 56, but by a stopper 37. picture! -1) i nM Kawa,
The mouse・t□□kA-1'38 forms arm parts 38a and 38b, and is pivotally connected to a shaft 39 and is υ by a spring 40.
This is a mirror first moving lever which is given dextrorotation but whose right rotation is inhibited by a stopper 41. In FIG. 2, 42 is the number of mirror boxes in which pins 43 and 45 are installed, and 4q is the shaft 4 fixed to the side plate 42.
a mirror 5 which is pivotally mounted on 4 and imparted with dextrorotation via a pin 48 projecting through a hole 47 formed in the side plate by a spring 46 supported on pin 43, 4'5;
0 is pivotally connected to the shaft 51 and the arm portion 50a9 surface 50
A spring 5.3 is tensioned between the control lever 5o and the next-described J-yage lever so as to impart dextrorotation to the control lever. has been done. Reference numeral 54 forms a hook portion 54a, and the charge lever is pivotally connected to the shaft 51 and is provided with left rotation by a spring 6o. Reference numeral 55 indicates the charge lever 5.
4 A bent portion 55a that can suppress the charging lever by engaging with the O-hook portion 54°a: It has a circular shape and is pivotally connected to the shaft 56 so that it can be rotated to the right by the tag 57. The second locking lever 58 is provided with a bending portion 58a, an arm portion 581), and is pivotally connected to a shaft 59, and is engaged with the second mirror interlocking lever 24.
1 is provided with left-handed rotation, but the left-handed rotation is inhibited by the pin 62, and is a first locking lever that can be engaged with the mirror first moving lever 58.

The focal plane shutter according to the present invention configured as described above operates as follows. That is, Figures 1 and 2
After the shutter is set as shown in the figure, the second mirror interlocking lever 24 is given levorotatory properties by the spring 26, so it comes into contact with the stopper 22 and is moved to the second engagement lever on the side of the mirror box. It is away from the stop lever 55. Further, the mirror first moving lever 38 is given dextrorotation by the spring 40, so it is in contact with the stopper 41, and is separated from the first locking lever 58 on the side surface of the mirror box. At this time, the i-locking lever 58 has its bent portion 5B&
is in contact with the arm portion 50a of the control lever 50 and restrains it, so that the surface 50b of the control lever 50 is in contact with the mirror 49.
The pin 48 is in contact with the pin 48 at the position shown in FIG. Therefore, mirror 49 is in the down state.

Next, when returning to the trailing curtain start position shown in FIGS. 6 and 4, the release lever 20 is unlocked and the trailing curtain operating arm 31 is rotated to the right by the tension of the spring 33, as shown in FIG. It is brought to the position. Therefore, the trailing curtain is returned to the starting position. At the same time, the @ section '58a of the mirror first moving arm 58 is pushed by the trailing blade actuating arm 31, causing the mirror first moving arm 38 to rotate to the left, and the arm section 381) of the first locking lever 58 Arm part 58 of ゛
By pushing b, the first locking lever 58 is rotated to the right. The control lever 50 is therefore unlocked and rotated to the right under the tension of the spring 56 until its bent portion 52 abuts the charge lever 54.

In this way, the surface 50b of the control lever 50 pushes the pin 48, causing the mirror 49ri to rotate upward against the tension of the spring 46, which has been selected to have a lower tension than the spring 56.

Thereafter, when the leading curtain locking lever 12 is turned to the right (for example, in conjunction with the up movement of the mirror or controlled by an electromagnet), the leading curtain actuating arm 9, which has been released from the restraint, locks the leading curtain actuating arm. The front curtain is rotated to the left by the tension of the spring 6 via the lever 8, and the front curtain releases the image frame 2, and exposure is started.

After the appropriate exposure time has elapsed, the trailing curtain locking lever 3 is activated by a known means.
4 is rotated to the right, and the trailing curtain drive arm 27, which has been released from restraint, is rotated to the left by the tension of the spring 29 together with the trailing curtain actuating arm 31. The second curtain thus covers the image frame 2 and the exposure is completed. At this time, the second mirror interlocking lever 24 is rotated to the right by the final stage operation of the trailing blade drive arm 27, and in conjunction with this, the second locking lever 55 is rotated to the left.

Therefore, the charge lever 54 whose restraint is released is the spring 60.
The control lever 5 is rotated to the left by the tension of the control lever 5.
0 is rotated to the left, the mirror 4911) is returned to the down state, and the rear curtain drive 7-A27 (i-ri final stage operation 1", 'l', nose,...
7. Since the contact L//14 is rotated to the right and the inhibition of the leading actuating arm 9 is released, the leading actuating arm 9 is rotated to the right.
is independently rotated to the right by the tension of the spring 11, and the leading curtain covers the picture frame 2. In this way, the picture frame is covered by both the front curtain and the rear curtain. The engagement relationship between the leading actuating arm 9 and the leading driving arm is determined by the fact that the leading actuating arm locking lever 8 comes into contact with the pillar 3 and is rotated to the right in the final stage of the counterclockwise rotation movement. It has been canceled. Here, right rotation of the leading actuating arm 9 is inhibited because its engaging portion 9a engages with the bent portion 14aK of the X contact lever 14.

This completes one shooting operation, but when the film is further wound up one more time, the charge lever 54 is rotated to the right, but the control lever 50 has its arm 50a locked in the first position and the bent portion 58a of the bar. Therefore, when the spring 60 is charged, the control lever 50 is in contact with the second locking lever 55.
The state shown in FIG. 2 is reached. In conjunction with the film winding operation, the front curtain drive arm 4. The rear curtain drive arms 27°, .1: are each rotated to the right, and are in the charged state shown in Fig. 1 -t
! 7) 11. -"""... As described above, according to the present invention, the operation process of the camera is as follows: camera release → rear curtain start position return → Mirai up → front curtain start → rear curtain start → front curtain start position return and mirror In order to release the mirror up lock in the final stage when the trailing curtain returns to the starting position, the operating speed at the final stage when the trailing curtain returns to the starting position is reduced. The size becomes smaller.

In addition, in order for the bounce to completely subside during the mirror-up process, it takes about 70 seconds to completely subside the bounce, which was previously required.
The time of m5 becomes unnecessary. This has the effect of greatly shortening the time from camera release to the start of the first curtain.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the shutter curtain opening/closing mechanism after the shutter is set in an embodiment of the focal plane shutter according to the present invention, and FIG. 2 is a diagram showing the embodiment according to FIG. 1. FIG. 3 is a diagram similar to FIG. 1 showing the state after the trailing curtain start position of the embodiment shown in FIG. 1 has been returned;
FIG. 4 is a diagram showing the mirror up-and-down mechanism in the same state as FIG. 3. DESCRIPTION OF SYMBOLS 1... Board, 2... Image frame, 4... Leading curtain drive arm, 8... Leading curtain operating arm locking lever, 9...
... Leading curtain operating arm, 12... Leading curtain locking lever,
14...X contact lever, 17...X contact, 20
...Release lever - 124-@Mirror second interlocking lever, 27...Tear curtain drive arm, 31...Tear curtain operating arm, 34...Tear curtain rear stop lever, 38...
Mirror first moving lever, 42...Mirror box side plate, -49...Mirror, 50...Control lever +, 54-...Change lever, 55...Second locking lever, 58...First locking lever. Agent Yasushi Shinohara Figure 1 Figure 2 Figures 3'3-3'4

Claims (1)

[Claims] In a single-return type focal plane shutter where the front curtain and rear curtain cover the image frame before and after the shutter is set, the mirror is now raised when the camera release is released and the rear curtain returns to the starting position. A focal plane shutter characterized by: