JPH02210428A - Focal plane shutter - Google Patents

Abstract

PURPOSE:To reduce installation space for a brake mechanism by using a single spring for a driving power source for a shutter blade running until the time in the running operation of the shutter blade and using the blade as a power source for braking from such time. CONSTITUTION:The spring 19 for driving the charged 1st blade is opened, the 1st blade group which is closing an apperture 7a for exposure is permitted to run in the direction that opens the apperture 7a and exposing operation is started. The spring 29, which is used for a second blade driving and is charged by the timing later than the timing that the spring 19 for the 1st blade driving is opened by the desired time, is opened. Therefore, the 2nd blade group, which is opening the aperture 7a for the exposure, is permitted to run in the direction that the apperture 7a is closed and the exposing operation is completed, and the brake member runs in the advancing direction by the energizing power of the driving spring. Thus, an impact absorbing mechanism which is less affected by temperature difference is obtained without the installation space and increasing the charging amount.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a focal plane shutter for a camera, and more particularly to a focal plane shutter equipped with a novel shock absorbing mechanism that effectively absorbs the shock at the end of shutter operation so as to be optimal for high-speed shutters with high shutter speeds.

[Conventional technology]

Focal plane shutters for modern cameras, especially reflex cameras, stabilize the accuracy of high-speed exposures.
Alternatively, in order to increase the strobe synchronization speed, the curtain speed of the shutter blades has been increased.2For example, taking the shutter for vertical movement 2, a few years ago, the image frame length of 24wm was reduced to about 7wm.
While it was common for vehicles to run at around 3 ms, in recent years they have started to run at around 3 ms. By the way, it is well known that the higher the curtain speed of a nuclide focal plane shutter, the greater the impact at the end of the shutter blade's travel, and that the above-mentioned impact increases operating noise and degrades durability. As such, focal plane shutters with high shutter speeds are generally equipped with a shock absorption mechanism to absorb shock, reduce operating noise, and improve durability. As a conventional shock absorbing mechanism, a brake lever that is pressed by a friction plate and a leaf spring is arranged on the passage path of the blade drive member, and the brake lever is rotated by the rear collision of the two blade drive members, and the nine blade drive members and shutter are rotated. It is generally known that the shutter blade absorbs the shock at the end of its travel by converting the kinetic energy of the blade into thermal energy generated by the friction between the friction plate and the brake lever.

[Problems to be solved by the invention]

However, such a friction-based shock absorption mechanism has
Since the friction coefficient of the friction plate is affected by temperature fluctuations, the shock absorption performance itself is also easily affected by temperature, and in addition to the shutter drive mechanism, there is insufficient space to install a brake lever and friction mechanism for shock absorption. Further, when charging the shutter, it is necessary to charge the shock absorbing mechanism in addition to the shutter driving mechanism, which causes problems such as an increase in the amount of charge.

[Means to solve the problem]

The present invention was made in view of these problems, and
It is an object of the present invention to provide a focal plane shutter equipped with a shock absorbing mechanism that is hardly affected by temperature fluctuations, does not particularly require installation space, and does not require an increase in the amount of shock absorber. In summary, the focal plane shutter of the present invention is:
By releasing the charged leading blade driving spring, the leading blade group which is in a state of shielding the exposing aperture is caused to run in the direction of opening the exposing aperture, and the leading blade driving spring is By releasing the charged rear blade drive spring at a desired time lag from the opening timing, the rear blade group which is in the state of opening the exposure aperture is moved to open the exposure aperture. This is based on a focal plane shutter that runs in the direction of shielding: each blade group is swingably supported at a fixed location relative to the camera body, and the swinging motion is an actuating member connected to each of the corresponding blade groups so as to operate the corresponding blade group in the forward direction and the backward direction; a drive member formed with an engaging portion that engages each of the corresponding actuation members from the backward direction to the forward direction; a braking member having an actuation arm that engages the member from the forward direction to the backward direction; and each of the driving springs has one end engaged with a fixed location with respect to the camera body, and the other end engaged with a fixed location with respect to the camera body. one end of which is oriented in a direction in which the actuating arm engages each of the corresponding actuating members from the forward direction to the backward direction with a source arm formed to face the actuating arm of each of the corresponding braking members; They are engaged to provide rotational force. More preferably, in the focal plane shutter of the present invention, the forward limit of each of the driving members is regulated so that the forward movement of each of the driving members ends before each of the corresponding actuating members reaches its forward limit. More preferably, in the focal plane shutter of the present invention, each of the actuating members and each of the corresponding blade groups are activated by each of the corresponding driving members after each of the corresponding driving members stops at its forward limit. It has an inertial force that allows it to run at least to its own forward limit against the rotational force applied from the spring to each of the corresponding braking members. More preferably, in the focal plane shutter of the present invention, the retraction limit of each of the drive members is formed at a position further back than the retraction limit of each of the corresponding actuation members. More preferably, the focal plane shutter of the present invention is further provided with an engaging member that engages the actuating member connected to the leading blade group at its forward movement limit.

[Effect]

Specifically, the focal plane shutter of the present invention basically releases a charged leading blade driving spring to move the leading blade group that is in a state of shielding the exposure aperture in the forward direction of opening the exposure aperture. The exposing operation is started by driving the vehicle toward the front blade, and the charged trailing blade driving spring is released at a timing with a desired time difference from the timing when the leading blade driving spring is released. The exposure operation is completed by causing the rear blade group, which is in the state of opening the exposure aperture, to travel in a forward direction that blocks the exposure aperture. Each driving spring applies a rotational force to the corresponding braking member in a direction such that its operating arm engages the corresponding operating member from the forward direction to the backward direction. The braking member is engaged from the backward direction to the forward direction by the engaging portion of the brake member, and the braking member is swingably supported on the corresponding drive member. The actuating member, the corresponding driving member, and the corresponding braking member maintain a relative position in which the one actuating member is held between the engaging portion of the driving member and the actuating arm of the brake portion +1. It travels in the forward direction due to the urging force of the driving spring. Furthermore, when the drive member travels to the forward limit, the forward movement of the drive member stops, so that the rotation applied from the drive spring to the braking member in the direction of engaging the corresponding actuating member from the forward direction to the backward direction. The actuating member receives a braking force due to the force, and the shock at the end of travel is alleviated, and the two actuating members resist the braking force by their own inertia force or the inertia force of the connected blade group, and at least limit their own forward movement. Proceed until. Furthermore, when the actuating member connected to the leading blade group advances to its forward limit, the actuating member is engaged. The leading blade is prevented from retreating due to the rotational force. Furthermore, since the retraction limit of each drive member is formed at a position that is more retracted than the retraction limit of each corresponding actuating member, each actuating member and each blade group connected thereto can be moved to the retracting limit. After returning, it is also possible to overcharge each drive member.

【Example】

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a group of blades constituting a leading blade 1 and a trailing blade 2 of a focal plane shutter according to an embodiment of the present invention, connection levers 3 and 4 for driving the leading blade 1, and a mechanism for driving the trailing blade 2. FIG. 3 is a plan view showing the initial state of the connecting levers 5 and 6, and an exposure aperture 7a formed in the center of the base plate 7 is shielded by the leading blade 1 in the initial state. First, the connecting lever 3 is supported by a shaft 8 and the connecting lever 4 is supported by a shaft 9 so as to be swingable on the base plate 7. The blades 1a, 1b, 1c-1d constituting the leading blade 1 are rotatably caulked to the connecting lever 3 by screws 3a, 3b, 3c, and 3d, respectively, and screws 4a, 4b, and 4c, respectively.
- It is rotatably caulked to the connecting lever 4 by 4d. Further, a leading blade driving bin 10 passing through a slot 7b formed in the base plate 7 is engaged with the connecting lever 3, and when the leading blade driving pin 10 is lowered along the slot 7b, the connecting lever 3 moves the shaft 8. The connecting lever 4 also rotates to the right around the shaft 9, so the blades 1a, 1b, 1c, and 1d that make up the leading blade 1 travel downward to open the aperture 7a. do. Similarly, the connecting lever 5 is connected to the connecting lever 6 by the shaft 11.
are swingably supported on the base plate 7 by shafts 12, respectively. The blades 2a, 2b, 2c, and 2d constituting the rear blade 2 are rotatably caulked to the connecting lever 5 by screws 5a, 5b, 5c, and 5d, respectively, and screws 6a, 6b, and 6c, respectively.
- It is rotatably caulked to the connecting lever 6 by 6d. Further, a rear blade drive bin 13 passing through a slot 7C formed in the base plate 7 is engaged with the connecting lever 5, and when the rear blade drive bin 13 is lowered along the slot 7c, the connecting lever 5 moves the shaft 11. The connecting lever 6 rotates to the right about the center, and in conjunction with this, the connecting lever 6 also rotates to the right about the shaft 12.
The blades 2a, 2b, 2c, and 2d that make up the aperture 7a run downward and shield the aperture 7a. Now, in the claw-brain shutter shown in Fig. 1, the time difference from when the leading blade 1 starts running until when the trailing blade 2 starts running corresponds to the exposure time, but the high-speed exposure time is stabilized. In addition, in order to increase the strobe synchronization speed, it is necessary to increase the curtain speed of the leading blade 1 and trailing blade 2. However, when the curtain speed is increased, large shocks and vibrations occur at the end of each shutter's operation.1 The focal plane shutter of the present invention uses a novel method to absorb the shock at the end of shutter operation. It is equipped with a shock absorbing mechanism, and its specific structure is shown in FIGS. 2 to 6. In addition, among these drawings, Fig. 2 shows the state immediately after the tail charge is completed, Fig. 3 shows the state immediately before the leading blade starts running, and Fig. 4 shows the state when the leading blade finishes running and the trailing blade starts moving. FIG. 5 shows the state before the vehicle starts traveling, FIG. 5 shows the state where the rear blade has finished traveling, and FIG. 6 shows the state where the shutter has been overcharged. Also, among the mechanical elements shown in FIGS. 2M to 6, there are many elements that are urged by springs, but in order to avoid complicating the drawings, those other than the springs that are important to the present invention are indicated by arrows. simply indicates the biasing force direction. Furthermore, in order to avoid complication of the four drawings, in FIGS. 3 to 6, only the elements referred to in the main text of the specification are provided with reference numerals when explaining each operating state. First, the driving mechanism of the leading blade will be explained. The aforementioned leading blade drive pin 10 is attached to the back side of the shaft 14 on the main plate 7.
A leading blade actuating lever 15 on which is implanted is swingably supported, and a leading blade driving lever 16 is also swingably supported on the shaft 14 on the near side of this leading blade actuating lever 15.
A leading blade braking lever 18 for transmitting braking force to the leading blade 1 while the leading blade 1 is running is swingably supported on a shaft 17 installed on the surface of the leading blade driving lever 16. Next, reference numeral 19 denotes a torsion spring that serves as a source of driving force for the leading blade 1 and also as a source of braking force for the leading blade 1 from the middle of its travel, and the fixed end of the torsion spring 19 is A torsion spring 19 is engaged with a pin 20 fixed to the outer camera body.
The operating end of the straight bending portion 1 formed on the leading blade brake lever 18
8a. Therefore, the leading blade brake lever 18 receives a left turning force about the shaft 17 from the torsion spring 19, but the arm 18b formed at the other end of the leading blade brake lever 18 Since the straight bent portion 15a is engaged with the arm 16a formed on the leading blade driving lever 16, the leading blade braking lever 18 is engaged with the straight bent portion 15a.
The counterclockwise rotation about the axis 17 of the leading blade actuating lever 15. is restricted in the initial state. Lead blade drive lever 1
6 and the leading blade brake lever 18 together receive right turning force about the shaft 14 from the torsion spring 19. However, in the initial state, the leading blade drive lever 1
6 is engaged with a locking lever 22 pivotally supported by a shaft 21 to restrict the clockwise rotation, and the locking lever 22 is prevented from rotating clockwise by an electromagnetic release member (not shown). After the engagement of the straight curved portion 16b is released, the right rotation becomes possible. Next, 23 is a stopper, and the leading blade operating lever 15 and the leading blade driving lever 16 come into contact with the stopper 23 and stop. Therefore, the leading blade operating lever 15 and the leading blade driving lever 1
6 has contact surfaces 15b and 16c that come into contact with the stopper 23.
However, in this embodiment, the characteristic point is that the contact surface 15b formed on the leading blade actuating lever 15 is set back from the contact surface 16c formed on the leading blade driving lever 16 in the initial state. There is a slight time difference between when the contact surface 16c comes into contact with the stopper 23 and when the contact surface 15b comes into contact with the stopper 23. In this embodiment, the force of the torsion spring 19 is applied to the leading blade braking within this time difference. The information is transmitted to the leading blade actuating lever 15 via the lever 18 to activate the leading blade 1.
It is designed to add braking force to the The details of the operation for transmitting the braking force will be described later. Next, the driving mechanism of the rear blade will be explained. The shaft 24 on the main plate 7 has the aforementioned rear blade drive pin 13 on the back side.
A trailing blade operating lever 25 on which a rear blade operating lever 25 is implanted is swingably supported, and a trailing blade driving lever 26 is also swingably supported on a shaft 24 in front of this trailing blade operating lever 25.
A rear blade brake lever 28 for transmitting braking force to the rear blade 2 while the rear blade 2 is running is swingably supported on a shaft 27 installed on the surface of the rear blade drive lever 26. Next, 29 is a torsion spring that serves as a source of driving force for the rear blade 2 and also as a source of braking force for the rear blade 2 from the middle of the travel of the rear blade 2. The fixed end of the torsion spring 29 is not shown. The torsion spring 29 is engaged with a pin 30 fixed to the camera body of
The operating end of the rear blade brake lever 28
8a. Therefore, the rear blade brake lever 28 receives a left turning force about the shaft 27 from the torsion spring 29, but the arm 28b formed at the other end of the rear blade brake lever 28 is attached to the rear blade operating lever 25. Since the pin 25a is engaged with the arm 26a formed on the rear blade drive lever 26, the left rotation of the rear blade brake lever 28 about the shaft 27 is restricted. Therefore, in the initial state, the trailing blade operating lever 25. The rear blade drive lever 26 and the rear blade brake lever 28 are integrally connected to the shaft 2.
A right turning force centered on 4 is received from the torsion spring 29. However, in the initial state, the rear blade drive lever 2
6 is engaged with a locking lever 32 pivotally supported by a shaft 31 to prevent the locking lever 32 from turning clockwise, and the locking lever 32 is rotated counterclockwise by an electromagnetic release member (not shown). After the engagement of the straight curved portion 26b is released, the above-mentioned right rotation becomes possible. Next, 33 is a stopper, and the rear blade operating lever 25 and the rear blade drive lever 26 come into contact with the stopper 33 and are stopped. Therefore, the rear blade operating lever 25 and the rear blade drive lever 2
6 has contact surfaces 25b and 26C that come into contact with the stopper 33.
However, in this embodiment, the characteristic feature is that the contact surface 25b formed on the rear blade actuating lever 25 is set back from the contact surface 26c formed on the rear blade driving lever 16 in the initial state. There is a slight time difference between when the contact surface 26c comes into contact with the stopper 33 and when the contact surface 25b comes into contact with the stopper 33. In this embodiment, the force of the torsion spring 29 is applied to the front blade braking within this time difference. The signal is transmitted to the rear blade operating lever 25 via the lever 28 and the rear blade 2 is
It is designed to add braking force to the The details of the operation for transmitting the braking force will be described later. Next, 34 is a set lever for initially setting the shutter mechanism. The set lever 34 is swingably supported by a shaft 35, and is connected to a set cam 37 via a center link 36.
Rotate to the right around 5. The set cam 37 rotates to the right around a shaft 38. - The cam surface 3' 7a formed on the set cam 37 is in contact with a set roller 16d rotatably supported by the leading blade drive lever 16, and when the center cam 37 rotates clockwise, the leading blade drive lever 16 is rotated counterclockwise. let Further, the cam surface 37b formed on the set cam 37 is in contact with a set roller 26d rotatably supported by the rear blade drive lever 27, and when the set cam 37 rotates clockwise, the rear blade drive lever 26 is rotated counterclockwise. . Further, 39 is a release lever, and the release lever 39
is swingably supported on a shaft 40, and is given left-handed rotation by a spring. The straight bent portion 39a formed on the release lever 39 engages the engagement piece 37c formed on the senodo cam 37 in the collar position, and the set cam 37
Regulates right rotation. Furthermore, 41 is a leading blade bounce which prevents the leading blade 1 from running backwards by engaging the leading blade operating lever 15 during the period after the leading blade 1 finishes running until the trailing blade 2 finishes running. The leading blade bound strike buckle 41, which is a stopper, is rotatably supported by the shaft 38 and is given a right-handed rotation by a spring, but is prevented from turning to the right by coming into contact with a stopper 42. The details of the leading blade bound stopper 41 will be described later. Next, the operation of this embodiment will be explained with reference to the above matters. First, in the initial state, the peripheral mechanism of the shutter blade is
It is in the state shown in the figure, and its drive mechanism is in the state shown in FIG. In this initial state, the biasing force in the counterclockwise direction applied to the set lever 34 by the spring is transmitted as a counterclockwise rotation force to the center cam force member 37 via the seven-stroke link 36; The engagement piece 37c is a straight curved portion 39a formed on the release lever 39.
The left rotation of the set cam 37 is restricted. Now, from this state, when the release lever 39 is rotated to the right against the biasing force of the spring, the straight bent portion 39a formed on the center lever 39 engages with the engagement piece 37c formed on the center cam 37. is released, and the left rotation restriction on the set cam 37 is released. Therefore, the left turning force applied from the spring to the set lever 34 is transmitted to the set cam 37 via the center link 36, and the set cam 37
7 rotates to the left. Due to this counterclockwise rotation of the set cam 37, the cam surface 37a formed on the center cam 37 and the set roller 16d supported by the leading blade drive lever 16 are separated, and at the same time, the cam surface 37b formed on the center cam 37 and the rear blade drive lever 26 are separated from each other.
Since the center roller 26d supported by the center roller 26d is separated, the leading blade drive lever 16 and the trailing blade drive lever 26 can be rotated to the right. The state at this time is the state shown in FIG. In the state shown in FIG. 3, the straight bent portion 16b formed on the leading blade drive lever 16 is engaged with the locking lever 22. Further, since the straight bent portion 26b formed on the trailing blade drive lever 26 is engaged with the locking lever 32, the leading blade 1 and the trailing blade 2 maintain their initial state. Now, after a predetermined timing has elapsed after the release lever 39 rotates to the right (this timing itself is created by an exposure control circuit not shown), the leading blade release magnet (not shown in Figure 2) is activated, and the spring is activated. Resisting the biasing force, the ζ locking lever 22 rotates to the right around the shaft 21,
The engagement of the leading blade drive lever 16 by the locking lever 22 is released. In the initial state, as described above, the leading blade operating lever 15. Leading blade drive lever 16 and leading blade braking lever 1
8 together receive the right turning force about the shaft 14 from the torsion spring 19, so when the engagement of the leading blade drive lever 16 by the locking lever 22 is released, the leading blade actuating lever 15 ．． Leading blade drive lever 16 and leading blade braking lever 1
8 rotate to the right around the shaft 14 as a unit. Therefore, the leading blade driving bin 10 installed on the back side of the leading blade operating lever 15 descends along the slot 7b, so that
The connecting lever 3 rotates to the right around the shaft 8, and in conjunction with this, the connecting lever 4 also rotates to the right around the shaft 9, so that the leading blade 1
The blades 1a, 1b, IC, and 1d that make up the structure travel downward to open the aperture 7a. Now, as mentioned above, the contact surface 15b formed on the leading blade actuating lever 15 is retracted from the contact surface 16c formed on the leading blade driving lever 16 in the initial state, so that the contact surface 16c contacts the stopper 23. Even after the right rotation of the leading blade drive lever 16 stops due to contact, the leading blade 1 and the connecting lever 3
4 and the leading blade actuating lever 15 continue to travel due to their own inertia, and the contact surface 1 formed on the leading blade actuating lever 15
5b comes into contact with the stopper 23, the running of the leading blade 1, the connecting levers 3 and 4, and the leading blade operating lever 15 is completed. By the way, in the right rotation process of the leading blade actuating lever 15 after the right turning of the leading blade driving lever 16 has stopped, the straight curved portion 15a of the leading blade actuating lever 15 separates from the arm 16a formed on the leading blade driving lever 16. At the same time, the straight bent portion 15
a engages the arm 18b formed on the leading blade brake lever 18, causing the leading blade brake lever 18 to rotate to the right while rotating to the right. Since the leading blade brake lever 18 receives a left turning force about the shaft 17 from the torsion spring 19, after the right turning of the leading blade drive lever 16 has stopped, the leading blade actuating lever 15
The leading blade braking lever 1 is torsioned by its own inertia force and the inertia force of the leading blade 1 and the connecting levers 3 and 4.
The vehicle continues to travel while rotating the leading blade braking lever 18 to the right against the left turning force applied to the leading blade actuating lever 15, the leading blade l, and the connecting levers 3 and 4. The braking force is received from the torsion spring 19 via the torsion spring 19, and shock and vibration at the end of running are alleviated. A contact surface 15 formed on the leading blade operating lever 15
When the leading blade l, the connecting levers 3 and 4, and the leading blade actuating lever 15 travel until the tip b contacts the stopper 23, the engaging surface 15c formed on the leading blade actuating lever 15 engages the leading blade bound stopper. 41, the left turning force received from the torsion spring 19 via the leading blade brake lever 18 prevents the leading blade operating lever 15 from being reversed. The state in which the leading blade operating lever 15 is engaged with the leading blade bound stopper 41 as described above is the state shown in FIG. 4. Then, at the timing when the proper exposure time has elapsed (the proper exposure time is created by an exposure control circuit not shown), a rear blade release magnet (not shown) is activated, and the locking lever 32 is activated by the spring. It rotates to the right around the shaft 31 against the biasing force, and the engagement of the rear blade drive lever 26 by the locking lever 32 is released. In the initial state, as described above, the trailing blade operating lever 25. Rear blade drive lever 26 and rear blade brake lever 2
8 integrally receives the right turning force about the shaft 24 from the torsion spring 29, so when the engagement of the rear blade drive lever 26 by the locking lever 32 is released, the rear blade actuation lever 25 ．． Rear blade drive lever 26 and rear blade brake lever 2
8 rotate to the right around the shaft 24 as a unit. Therefore, the rear blade drive pin 13 installed on the back side of the rear blade actuation lever 25 descends along the slot 7c.
The connecting lever 5 rotates to the right around the shaft 11, and in conjunction with this, the connecting lever 6 also rotates to the right around the shaft 12, so the blades 2a, 2b, 2c'2d constituting the rear wing II 2 are rotated downward. The vehicle travels to cover the aperture 7a. Now, as mentioned above, the contact surface 25b formed on the rear blade actuation lever 25 is retracted from the contact surface 26c formed on the rear blade drive lever 26 in the initial state, so that the contact surface 26c contacts the stopper 33. Even after the right rotation of the rear blade drive lever 26 stops due to contact, the rear blade 2 and the connecting lever 5
6 and the rear blade operating lever 25 continue to travel due to their own inertia, and the contact surface 2 formed on the rear blade operating lever 25
When the rear blade 5b comes into contact with the stopper 33, the movement of the rear blade 2, the connecting levers 5 and 6, and the rear blade operating lever 25 is completed. By the way, in the right rotation process of the trailing blade actuating lever 25 after the right turning of the trailing blade driving lever 26 has stopped, the pin 25a of the trailing blade actuating lever 25 moves away from the arm 26a formed on the trailing blade driving lever 26. At the same time, the pin 25a engages the arm 28b formed on the rear blade brake lever 28, causing the rear blade brake lever 28 to rotate clockwise. Since the rear blade brake lever 28 receives a left turning force about the shaft 27 from the torsion spring 29, after the right rotation of the rear blade drive lever 26 has stopped, the rear blade operating lever 25
The rear blade brake lever 2 is moved from the torsion spring 29 by its own inertia force and the inertia force of the rear blade 2 and the connecting levers 5 and 6.
The vehicle continues to run while rotating the rear blade brake lever 28 to the right against the left turning force applied to the rear blade brake lever 28 . The braking force is received from the torsion spring 29 via the torsion spring 29, and the shock and vibration at the end of running are alleviated. Further, when the rear blade operating lever 25 rotates to the right until the contact surface 25b formed on the rear blade operating lever 25 comes into contact with the stopper 33, the protrusion 2 formed on the rear blade operating lever 25
5c engages the engaging portion 41b of the leading blade bound stopper 41 and rotates the leading blade bound stopper 41 to the right around the shaft 38, so that the leading blade operating lever 15 is not engaged by the leading blade bound stopper 41. It will be canceled. FIG. 5 shows the state in which the trailing blade 2 has finished traveling in this manner. When the leading blade actuating lever 15 is disengaged, the leading blade actuating lever 15 is rotated to the left by the left turning force transmitted from the torsion spring 19 via the leading blade brake lever 18, and the leading blade 1 is rotated to the left.
However, since the aperture 7a is shielded by the rear blade 2 at this point, it is not substantially affected at all. Now, after one exposure operation is completed as described above,
When the set lever 34 rotates to the right about the shaft 35 against the biasing force of the spring in conjunction with the film winding operation by the motor or manually, the centrifuge cam 37 rotates to the right via the centrifugal link 36. As the set cam 37 rotates clockwise, the cam surface 37a formed on the set cam 37 comes into contact with the set roller 16d rotatably supported by the leading blade drive lever 16, causing the leading blade drive lever 16 to rotate counterclockwise. Further, the cam surface 37b formed on the set cam 37 contacts a set roller 26d rotatably supported by the rear blade drive lever 26, thereby causing the rear blade drive lever 26 to rotate to the left. The leading blade braking lever 18, which is pivotally supported on the leading blade driving lever 16, receives a left turning force from the spring 19, so when the leading blade driving lever 16 turns left, the leading blade actuating lever 15 also moves with the straight curved part 15a first. It rotates to the left while being engaged with the arm 18b of the blade brake lever 18, and the connecting levers 3 and 4 also rotate to the left to return the leading blade 1 to its initial position. In this return process, when the leading blade drive pin 10 installed in the leading blade actuating lever 15 comes into contact with the upper end of the slot 7b, the leading blade l, the connecting levers 3 and 4, and the leading blade actuating lever 15 return to their initial state. Although the operation stops, the set cam 37
Since the leading blade drive lever 16 that is in direct contact with the leading blade actuating lever 15 is constructed separately from the leading blade actuating lever 15, the leading blade driving pin 10 comes into contact with the upper end of the thrower 1-7b, and the leading blade 1
Even after the connecting levers 3 and 4 and the leading blade operating lever 15 have stopped, the leading blade driving lever 16 continues to rotate to the left, resulting in overcharging. Similarly, the rear blade brake lever 28, which is pivotally supported on the rear blade drive lever 26, receives a left turning force from the spring 29, so when the rear blade drive lever 26 turns left, the pin 25a of the rear blade actuating lever 25 is rotated. It rotates to the left while being engaged with the arm 28b of the rear blade brake lever 28, and the connecting lever 5.
6 also rotates to the left to return the rear blade 2 to its initial position. In this return process, when the trailing blade drive pin 13 installed in the trailing blade operating lever 25 comes into contact with the upper end of the slot 7C, the trailing blade 2, the connecting levers 5 and 6, and the trailing blade operating lever 25 return to their initial state. However, since the rear blade drive lever 26 that comes into direct contact with the centrifuge cam 37 is constructed separately from the rear blade actuation lever 25, the rear blade drive pin 13 comes into contact with the upper end of the thrower 1-7c. Even after the trailing blade 2, the connecting levers 5 and 6, and the trailing blade operating lever 25 stop, the trailing blade drive lever 26 continues to rotate to the left, resulting in overcharging. The state in which overcharging is completed in this manner is the state shown in FIG. Thereafter, when the right turning force applied to the set lever 34 is released, the set lever 34 turns left by the biasing force of the spring, and in conjunction with this, the set cam 37 also turns left. Then, the engaging piece 37C formed on the bottom cam 37 is engaged with the straight bent part 39a formed on the release lever 39, and all the mechanisms return to the initial state shown in FIG. 2.

【effect】

As explained above, according to the present invention, a single spring is used as a driving force source for the movement of the shutter blade until the middle of the movement of the shutter blade, and from the middle of the movement of the shutter blade. Since it is used as a force source for braking the shack blade, there is no need to separately provide a braking spring, and the installation space for the braking mechanism is reduced. Furthermore, according to the present invention, since there is no member that causes friction to brake the shutter blade, the shutter is not affected by fluctuations in the coefficient of friction due to temperature changes, and the shutter can be opened stably regardless of the environment in which the camera is used. properties, and there is no decrease in shock absorption ability due to wear. Furthermore, as described above, in the present invention, the spring for driving the shutter also serves as a force source for braking the shutter, so there is no need to charge the braking mechanism separately from the shutter driving mechanism, and an increase in the amount of charge can be prevented. Furthermore, according to the present invention, l! +! Since the blades that serve as the power source and the members connected to the shutter blades can be separated, the shutter blades themselves are not overcharged (in other words, the space above and below the shutter blades is expanded due to the overcharging of the shutter blades themselves). ) It is possible to overcharge the springs that are the driving force source, and the 5-charge operation can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a blade peripheral mechanism of a focal plane shutter according to an embodiment of the present invention, FIG. 2 is a plan view showing a shutter charging state of a shutter drive mechanism according to an embodiment of the present invention, and FIG. is a plan view showing the state of the leading blade of the mechanism shown in FIG. 2 just before it starts running, and FIG.
A plan view showing the state before the leading blade of the mechanism shown in the figure finishes running and the trailing blade starts running. Figure 5 shows the state where the trailing blade of the mechanism shown in Figures 2 to 4 has finished running. FIG. 6 is a plan view showing the overcharge state of the mechanism shown in FIGS. 2 to 5; FIG. 1... Leading blades 1a, 1b, IC, 1d... Blades 2... Trailing blades 2a, 2b, 2C, 2d... Blades 3, 4, 5, 6... Connection lever 7... Main plate 7a...Aperture 7
b・7c...Slot 10...Leading blade drive bin 1
3... Rear blade drive bin 15... Lead blade operating lever 15a... Banquet part 15b... Contact surface 16.
...Top blade drive lever 16a...Arm 16c...Contact surface 18.
...Top blade brake lever 18b...Arm 19...Torsion spring 22
...Latching lever 23...Stopper 25...
Rear blade operating lever 25a...Bin 25b...Contact surface 26.
... Rear blade drive lever 26a ... Arm 26c ... Contact surface 28 ...
... Rear blade brake lever 28b ... Arm 29 ... Torsion spring 32
...Latching lever 33...Stopper 34...
Set lever 36... Set link 37... Set cam 41... Leading blade bound stopper Patent applicant Konogu 11 Co., Ltd. Agent Patent attorney Hikaru Murakami

Claims (5)

[Claims] (1) By releasing the charged leading blade driving spring, the leading blade group that is in a state of shielding the exposure aperture is caused to run in the direction of opening the exposure aperture, and the leading blade is By opening the charged rear blade driving spring at a timing with a desired time difference from the timing when the driving spring is released, the rear blade group in the state where the exposure aperture is opened is exposed. In a focal plane shutter configured to run in the direction of blocking the aperture, each of the blade groups is swingably supported at a fixed location relative to the camera body, and responds by swinging motion. an operating member connected to each of the corresponding blade groups to operate the blade group in the forward direction and backward direction; and an actuating member that is swingably supported at a fixed location with respect to the camera body, a driving member formed with an engaging portion that engages each operating member from a backward direction to a forward direction; and a driving member that is swingably supported on each of the driving members and that moves each corresponding operating member forward. a braking member having an actuating arm that engages in a backward direction from the camera body; one end of each of the drive springs is engaged with a fixed location with respect to the camera body, and the other end is engaged with a fixed location with respect to the camera body; Applying a rotational force in a direction in which the actuating arm engages each of the corresponding actuating members from a forward direction to a backward direction to a source arm formed opposite to the actuating arm of each corresponding braking member. A focal plane shutter characterized by being engaged in a similar manner. (2) In the focal plane shutter according to claim 1, each of the drive members has its own forward limit set so that the forward motion is completed before each of the corresponding actuating members reaches its forward limit. A focal plane shutter characterized by being regulated. (3) In the focal plane shutter according to claim 2, each of the actuating members and each of the corresponding blade groups:
After each of the corresponding driving members stops at its forward limit, resisting the rotational force applied from each of the corresponding driving springs to each of the corresponding braking members,
A focal plane shutter characterized by having an inertial force capable of traveling at least to its forward limit. (4) In the focal plane shutter according to claims 1 to 3, the retraction limit of each of the drive members is formed at a position that is more retracted than the retraction limit of each of the corresponding actuating members. A focal plane shutter characterized by: (5) In the focal plane shutter according to claims 1 to 4, an engaging member is provided that engages the actuating member connected to the leading blade group at its forward movement limit. Features a focal plane shutter.