JP2817051B2 - Focal plane shutter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a focal plane shutter for a camera, and more particularly to a focal plane shutter capable of reducing a charging force of a shutter driving mechanism.

TECHNICAL BACKGROUND OF THE INVENTION

In recent years, cameras with built-in motors have become popular in order to automate film winding. Particularly in single-lens reflex cameras with built-in motors that use a focal plane shutter, besides film winding and shutter charging, Charging of the mirror mechanism, the automatic aperture mechanism, and the like is also performed by using the motor as a drive source. Therefore, in this type of camera with a built-in motor,
In order to reduce the load on the motor and the driving power supply, it is required to reduce the charging power of various mechanisms. For this reason, in the focal plane shutter,
The charge force is reduced by reducing the moment of inertia of the driven member by reducing the weight of the blades. However, today, when a higher curtain speed is required, the reduction of the charge force by reducing the weight of the blades is not possible. You are already at the limit.

[Means for solving the problems]

The present invention has been made in view of such circumstances,
The aim is to reduce the amount of charging force by improving the transmission efficiency of the charging force. In summary, the focal plane shutter according to the present invention is: By releasing the charged front blade driving spring, the front blade group, which is in the state of blocking the exposure aperture, is directed in the direction of opening the exposure aperture. And releasing the charged rear blade driving spring at a timing that is a desired time difference from the timing at which the leading blade driving spring is released, thereby opening the exposure aperture. The present invention presupposes a focal plane shutter that causes a certain rear blade group to travel in a direction that shields the exposure aperture: for each of the blade groups: connected to each of the blade groups; By the reciprocating operation, the corresponding blade group is operated in the forward and backward directions. And a drive member having an engagement portion formed to be engaged by the respective drive springs and to engage the corresponding respective operation members from the backward direction to the forward direction. The driving members of
The forward limit is regulated so that the forward movement ends before each corresponding operating member reaches the forward limit.

[Action]

In other words, the focal plane shutter of the present invention basically releases the charged front blade driving spring, thereby opening the front blade group that is in a state of blocking the exposure aperture to open the exposure aperture. By starting the exposure operation by running in the direction, the charged rear blade driving spring is released at a timing having a desired time difference from the timing at which the leading blade driving spring is released, whereby The exposure operation is completed by moving the rear blade group in a state where the exposure aperture is opened in a forward direction in which the exposure aperture is shielded. The driving spring provided for each blade group urges the corresponding driving member in the forward direction, and the corresponding operating member is engaged with the corresponding driving member and travels in the forward direction. After each drive member travels to the forward limit and is defined to advance, the corresponding operating member coasts to its forward limit by inertia, so that the operating angle of the drive member is smaller than the operating angle of the operating member. And the transmission efficiency of the charging force at the time of initial charging can be improved.

【Example】

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Before describing a specific embodiment, the basic principle of the present invention will be described with reference to FIG. _{First, A (A 1 · A 2} · A 3) in FIG. 1 is a target charge member which is pivotally supported on the shaft B, and the swinging range of the angle theta _1. Cam follower P is, for example, the distal end portion of the charge member _{A (P 1 · P 2 ·} P 3) is provided, in the case where the position of the travel upon completion of the cam follower and a point P _1, the cam follower P is the charge member A of the length passes through the point P ₂ on the arc C whose radius, returning to the initial set position P _{3. Then, D (D 1 · D 2} · D 3) is set a cam for charging to be charge member A, it is pivotally supported on the axis E. When the set cam D to the right-handed toward the position of the D ₃ from the position of D _1, set cam D cam follower P and the point P ₁ · P ₂ ·
While abutting successively at the positions of P _3, is left-handed toward the position of A ₃ to be set member A from the position of A _1. That is, the rotational force of the set cam D becomes a charge driving force for charging the charged member A. Now, when the cam follower P is in the position of the point P ₁ · P ₂ · P _3, the turning locus of the set cam D of the charge driving force F each point P ₁ · P ₂ · P ₃ is the rotational force of the set cam D Facing the tangent direction of. On the other hand, when the cam follower P is in the position of the point P ₁ · P ₂ · P _3, charging force f is the charge member at each point P ₁ · P ₂ · P ₃ transmitted from the set cam D to be charge member A A
In the tangent direction of the turning trajectory. The magnitude of the charge force f at each point P ₁ · P ₂ · P ₃ is tangent to the turning locus of the tangent and the set cam D of the turning locus of the charge member A at each point P ₁ · P ₂ · P ₃ the angle at which the bets are formed when defined as theta _2, represented by f = Fcosθ _2. That is, the maximum is when there from charge driving force F set cam D is generated in the position of the point P ₂ on the line segment transmission efficiency to the charge force f of the charge member A is the cam follower P is connecting axis B and axis E in transmission efficiency as the position of the cam P leaves the position of the above P ₂ decreases. Accordingly, the improved overall transmission efficiency of if you can makes it narrow the set angle theta ₁ of the charge member A, the charge driving force F to the charge force f. However, in the conventional shutter mechanism to be charge member A is connected to the closing mechanism of directly shutter blade, set angle theta ₁ of the charge member A were to correspond one-to-one with operating angle of the opening and closing mechanism of the shutter blade so it means that makes it narrower also operating angle of the opening and closing mechanism of the shutter blade when tighten become narrow the set angle theta ₁ of the charge member a, increasing the operation amount of the amplification factor of the opening and closing mechanism of the shutter blade Therefore, the improvement in the transmission efficiency from the charge driving force F to the charge force f is offset by the increase in the amplification factor of the operation amount in the opening / closing mechanism of the shutter blade, and as a result, the charge amount cannot be reduced. . According to the present invention, the charged member is separated from the shutter blade opening / closing mechanism, and the turning of the charged member is already stopped when the shutter blade opening / closing mechanism is in the middle of traveling.
Thereafter, the shutter blade opening / closing mechanism is caused to coast by the inertial force, so that the operating angle of the shutter blade opening / closing mechanism is maintained while the set angle θ of the charged member is maintained.
By narrowing ₁ , the transmission efficiency from the charge driving force F to the charging force f is improved, and the amount of charging force is reduced. Next, FIG. 2 shows a blade group constituting the front blade 1 and the rear blade 2 of the focal plane shutter according to one embodiment of the present invention, and connecting levers 3 and 4 for running the front blade 1.
FIG. 4 is a plan view showing an initial state of connecting levers 5 and 6 for running rear blade 2, and an aperture 7 a for exposure formed in a central portion of main plate 7 is shielded by front blade 1 in an initial state. . First, the connection lever 3 is supported by a shaft 8 and the connection lever 4 is supported by a base plate 7 by a shaft 9 so as to be swingable. Each of the blades 1a, 1b, 1c, and 1d constituting the leading blade 1 has a screw.
The connecting lever 3 is rotatably caulked to the connecting lever 3 by 3a, 3b, 3c, 3d, and is rotatably caulked to the connecting lever 4 by screws 4a, 4b, 4c, 4d. Further, the leading blade driving pin 10 penetrating through the 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 causes the shaft 8 to move. Turn clockwise to the center and link lever 4
Also, the blade 1a, 1b, 1c, 1d constituting the leading blade 1 travels downward to open the aperture 7a. Similarly, the connecting lever 5 is connected to the connecting lever 6 by the shaft 11.
Are supported by the shaft 12 so as to be swingable on the base plate 7, respectively. The blades 2a, 2b, 2c, 2d constituting the rear blade 2 are 5a
The connecting lever 5 is swaged by the connecting levers 5b, 5c, and 5d, and the connecting lever 6 is screwed by screws 6a, 6b, 6c, and 6d, respectively.
Is swiveled. Further, the rear blade drive pin 13 penetrating the slot 7c formed in the base plate 7 is engaged with the connection lever 5, and when the rear blade drive pin 13 is lowered along the slot 7c, the connection lever 5 causes the shaft 11 to move. Turn clockwise to the center and move the connecting lever 6
Also, the wing 2 rotates clockwise about the axis 12, so that the blades 2a, 2b, 2c, and 2d constituting the rear blade 2 travel downward to shield the aperture 7a. Next, FIGS. 3 to 5 are plan views showing one embodiment of a drive mechanism for driving the shutter mechanism shown in FIG. 2. In these drawings, FIG. 3 shows that the shutter is charged. FIG. 4 shows a state in which the leading blade has finished traveling and before the trailing blade has started traveling, and FIG. 5 shows a state in which the trailing blade has terminated traveling. 3 to 5
Although many of the mechanical elements shown in the drawings are biased by springs, only the biasing directions are indicated by arrows except for the springs important to the present invention in order to avoid complication of the drawing. Further, in order to avoid complication of the drawings, in FIGS. 4 and 5, only the elements referred to in the text of the manual when describing the respective operating states are denoted by reference numerals. First, the driving mechanism of the leading blade will be described. A front blade actuating lever 15 having the front blade driving pin 10 described above implanted on the back surface of the shaft 14 on the base plate 7 is swingably supported.
A front blade driving lever 16 (in the present embodiment, the front blade driving lever 16 corresponds to the charged member A shown in FIG. 1) is located on the front side of the front blade operating lever 15 so as to be swingable about the shaft 14. It is supported, and a weak spring 18 is bridged between the lever 15 for operating the front blade and the driving lever 16 for the front blade. Reference numeral 19 denotes a torsion spring which serves as a driving force source for the front blade 1. The fixed end of the torsion spring 19 is engaged with a pin 20 fixed to a camera body (not shown). The working end of 19 is engaged with a pin 17 implanted in the leading blade drive lever 16,
The leading blade drive lever 16 receives a right turning force about the shaft 14 from the torsion spring 19. The bent portion 15a formed on the leading blade operating lever 15
Is engaged with the arm 16a formed on the leading blade driving lever 16, so that the leading blade operating lever 15 is also engaged with the leading blade driving lever 16.
A right turning force about the shaft 14 is received from the torsion spring 19 via 16. However, in the initial state, the front blade drive lever
The bent portion 16b formed on the shaft 16 is engaged with a locking lever 22 supported on a shaft 21 to restrict the clockwise rotation. The locking lever 22 is clockwise rotated by an electromagnetic release member (not shown). Standing
After the engagement of 16b is released, the clockwise rotation becomes possible. Next, reference numeral 23 denotes a stopper, and the leading blade operating lever 15 and the leading blade drive lever 16 come into contact with the stopper 23 and stop. Therefore, the leading blade operating lever 15 and the leading blade driving lever 16
Are provided with contact surfaces 15b and 16c, respectively, which contact the stopper 23. In this embodiment, the contact surface 15b formed on the leading blade operating lever 15 is characterized by
After the contact surface 16c abuts the stopper 23 and the leading blade drive lever 16 stops traveling, the leading blade actuating lever 15 is brought into contact with the contact surface 15b. Coasts by inertial force until abuts against the stopper 23. That is, in this embodiment, the operating angle of the front blade drive lever 16 corresponding to the charged member A in FIG.
Is smaller than the operating angle of the leading blade operating lever 15, which is a member connected to the first blade. Next, the drive mechanism of the rear blade will be described. A rear blade operating lever 25 having the rear blade driving pin 13 described above implanted on the back surface of the shaft 24 on the main plate 7 is swingably supported.
A rear blade drive lever 26 is provided on the front side of the rear blade operation lever 25.
(In this embodiment, the rear blade drive lever 26 also corresponds to the charged member A shown in FIG. 1). The rear blade drive lever 26 is also swingably supported by the shaft 24, and the rear blade operation lever 25 and the rear blade A weak spring 28 spans between the drive levers 26. Next, reference numeral 29 denotes a torsion spring serving as a driving force source of the rear blade 2, and a fixed end of the torsion spring 29 is engaged with a pin 30 fixed to a camera body (not shown). The working end of 29 is engaged with a pin 27 implanted in the rear blade drive lever 26,
The rear blade drive lever 26 receives a right turning force about the shaft 24 from the torsion spring 29. Since the pin 25a implanted in the rear blade operating lever 25 is engaged with an arm 26a formed on the rear blade driving lever 26, the rear blade operating lever 25 also controls the shaft 24 via the rear blade driving lever 26. The right-handed turning force at the center is received from the torsion spring 29. However, in the initial state, the rear blade drive lever
When formed on 26, the bent portion 26b is engaged with the locking lever 32 supported by the shaft 31 to restrict the clockwise rotation. The locking lever 32 is clockwise rotated by an electromagnetic release member (not shown). Standing
After the engagement of 26b is released, the clockwise rotation becomes possible. Next, reference numeral 33 denotes a stopper, and the rear blade operating lever 25 and the rear blade drive lever 26 come into contact with the stopper 33 and stop. Therefore, the rear blade operating lever 25 and the rear blade drive lever 26
Are formed with contact surfaces 25 and 26c, respectively, which contact the stopper 33. In this embodiment, the contact surface 25b formed on the rear blade operating lever 25 is characterized by
In the present embodiment, the rear blade operating lever 25 is retracted after the contact surface 26c abuts the stopper 33 and the blade driving lever 26 stops traveling. It coasts by inertia until the contact surface 25b contacts the stopper 33. That is, in this embodiment, the operation angle of the rear blade drive lever 26 corresponding to the charged member A in FIG. 1 is the rear blade operation lever 25 which is a member connected to the rear blade 2.
Smaller than the operating angle of Next, reference numeral 34 denotes a set lever for initially setting the shutter mechanism. The set lever 34 is swingably supported by a shaft 35, and a set cam 37 (in the present embodiment, this set cam 37 corresponds to the set cam D shown in FIG. 1) via a set link 36. When the set lever 34 is turned clockwise about the shaft 35 against the urging force of the spring, the set cam 37 turns clockwise about the shaft 38. A cam surface 37a formed on the set cam 37 is in contact with a set roller 16d rotatably supported by the leading blade drive lever 16, and rotates the leading blade drive lever 16 counterclockwise when the set cam 37 rotates clockwise. A cam surface 37b formed on the set cam 37 is rotatably supported by the rear blade drive lever 26 and is in contact with the set roller 26d. When the set cam 37 rotates clockwise, the rear blade drive lever 26 rotates left. . Further, reference numeral 41 denotes a front blade bound for preventing the front blade 1 from running backward by engaging the front blade operating lever 15 during the period after the front blade 1 has finished traveling and before the rear blade 2 has finished traveling. Stopper, tip blade bound stopper
The shaft 41 is rotatably supported by the shaft 38, and is provided with a right-turning property by a spring. The details of the front blade bound stopper 41 will be described later. Next, the operation of this embodiment will be described with reference to the above items. First, in the initial setting state, the peripheral mechanism of the shutter blade is in the state shown in FIG. The drive mechanism is the third
In the state shown in FIG. 3, in the state shown in FIG. 3, the leading blade drive lever 16 receives right turning force from the torsion spring 19 and the rear blade drive lever 26 receives right turning force from the torsion spring 29, respectively. A bent portion 16b formed on the leading blade drive lever 16 is engaged with the locking lever 22, and a bent portion 26b formed on the trailing blade drive lever 26 is formed.
Are engaged with the locking lever 32, the leading blade 1 and the trailing blade 2 maintain the initial state. By operating the unillustrated front blade release magnet in conjunction with the shutter release operation, the locking lever 22 rotates clockwise about the shaft 21 against the urging force of the spring, and the locking lever 22 rotates. , The engagement of the leading blade drive lever 16 is released. Therefore, the leading blade drive lever 16 rotates clockwise around the shaft 14 by the biasing force from the torsion spring 19, and the leading blade operating lever 15
Also, the bent portion 15a rotates clockwise about the shaft 14 while being engaged with the arm 16a of the leading blade drive lever 16. Therefore, the leading blade driving pin 10 implanted on the back surface of the leading blade operating lever 15 descends along the slot 7b, so that the connecting lever 3 rotates clockwise about the shaft 8 and moves in conjunction with this. The blade 1a, 1b, 1c, and 1d constituting the leading blade 1 also travels downward to open the aperture 7a. Now, as described above, the contact surface 15b formed on the leading blade operating lever 15 is the contact surface 16c formed on the leading blade driving lever 16.
Than the contact surface 16c
After the abutment with the stopper 23 stops the clockwise rotation of the leading blade drive lever 16, the leading blade 1, the connecting levers 3.4, and the leading blade operating lever 15 extend the spring 18 by their own inertial force (accordingly, The tension of the spring 18 is required to be smaller than the inertial force of the leading blade 1, the connecting levers 3.4, and the leading blade operating lever 15.) The running is continued, and the contact surface 15b formed on the leading blade operating lever 15 is When it comes into contact with the stopper 23, the front blade 1, the connecting levers 3 and 4, and the front blade operating lever 15
The traveling of is ended. The contact surface 15b formed on the leading blade operating lever 15
Until the blade comes into contact with the stopper 23, and the connecting blade 3.
4 and the leading blade operating lever 15 travel, the engaging surface 15c formed on the leading blade operating lever 15 is engaged with the arm 41a of the leading blade bound stopper 41. Of the leading blade operating lever 15 is prevented from being inverted. 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. Subsequently, at the timing when the appropriate exposure time has elapsed (the appropriate exposure time is created by an exposure control circuit (not shown)), the magnet for the rear blade release (not shown) is actuated, and the locking lever 32 is actuated by the spring. The right-handed rotation about the shaft 31 is performed against the urging force, and the engagement of the rear blade drive lever 26 by the locking lever 32 is released. Therefore, the rear blade drive lever 26 rotates clockwise around the shaft 24 by the biasing force from the torsion spring 29, and the rear blade operation lever 25
Also, the pin 25a rotates clockwise about the shaft 24 while the pin 25a is engaged with the arm 26a of the rear blade drive lever 26. Accordingly, the rear blade drive pin 13 implanted on the back surface of the rear blade operating lever 25 descends along the slot 7c, so that the connecting lever 5 turns clockwise around the shaft 11 and interlocks with this. Also, the wing 2 rotates clockwise about the axis 12, so that the blades 2a, 2b, 2c, and 2d constituting the rear blade 2 travel downward to shield the aperture 7a. Now, as described above, the contact surface 25b formed on the rear blade drive lever 25 is the contact surface 26c formed on the rear blade drive lever 26.
Than the contact surface 26c
The rear blade 2, the connecting levers 5 and 6, and the rear blade actuating lever 25 extend the spring 28 by their own inertia force even after the right rotation of the rear blade drive lever 26 stops due to contact with the stopper 33 (accordingly, The tension of the spring 28 is required to be smaller than the inertia force of the rear blade 2, the connecting levers 5 and 6, and the rear blade operating lever 25.) The traveling is continued, and the contact surface 25b formed on the rear blade operating lever 25 is When it comes into contact with the stopper 33, the rear blade 1, the connecting levers 5, 6 and the rear blade operating lever 25
The traveling of is ended. When the rear blade operating lever 25 turns clockwise until the contact surface 25b formed on the rear blade operating lever 25 contacts the stopper 33, the projection 25c formed on the rear blade operating lever 25 Since the engaging portion 41b is engaged and the front blade bound stopper 41 is turned clockwise about the shaft 38, the engagement of the front blade operating lever 15 by the front blade bound stopper 41 is released. FIG. 5 shows a state in which the traveling of the rear blade 2 has been completed in this way. When the leading blade operating lever 15 is disengaged, the leading blade operating lever 15 rotates counterclockwise due to the tension of the spring 18, causing the leading blade 1 to travel in the ascending direction (closing direction). Since it is shielded by, there is no substantial effect. After one exposure operation is completed as described above, when the set lever 34 is turned clockwise around the shaft 35 against the urging force of the spring in conjunction with the film winding operation by the motor, the set link Set cam 37 through 36
Turns clockwise. With the clockwise rotation of the set cam 37, the cam surface 37a formed on the set cam 37 comes into contact with a set roller 16d which is rotatably supported by the front blade drive lever 16 to rotate the front blade drive lever 16 counterclockwise. , And a cam surface formed on the set cam 7
37b comes into contact with a set roller 26d rotatably supported by the rear blade drive lever 26, and rotates the rear blade drive lever 26 counterclockwise. When the leading blade drive lever 16 rotates counterclockwise, the leading blade operating lever
15 also has the bent portion 15a formed by the arm 16a by the tension of the spring 18.
And the connecting levers 3 and 4 also turn left to return the leading blade 1 to the initial position. Similarly, when the rear blade drive lever 26 rotates counterclockwise, the rear blade operating lever 25 also rotates counterclockwise while the pin 25a follows the arm 26a due to the tension of the spring 28, and the connecting levers 5 and 6 also rotate counterclockwise to move the rear blade 2 to the initial position. Return to. As described above, in this embodiment, the contact surface 15 formed on the front blade operating lever 15 which is a member connected to the front blade 1 is provided.
Before the b contacts the stopper 23 and the leading blade operating lever 15 stops traveling, the contact surface 16c formed on the leading blade drive lever 16 as a charged member contacts the stopper 23 to stop traveling. Therefore, the operation angle of the front blade drive lever 16 which is a charged member is smaller than the operation angle of the front blade operation lever 15 which directly corresponds to the operation stroke of the front blade 1. Similarly, in the present embodiment, as described above, the contact surface formed on the rear blade operating lever 25 which is a member connected to the rear blade 2
Before the rear blade actuating lever 25 stops traveling due to the contact of the stopper 25 with the stopper 33, the contact surface 26c formed on the rear blade drive lever 26, which is a charged member, contacts the stopper 33 and stops traveling. Therefore, the rear blade drive lever 26 which is a charged member is smaller than the operation angle of the rear blade operation lever 25 which directly corresponds to the operation stroke of the rear blade 2.
Operating angle is smaller. As already discussed with reference to FIG. 1, if the operating angle of the member A to be charged can be reduced while maintaining the operating angle of the member connected to the blade, it is the rotational force of the set cam D. The transmission efficiency from the charge driving force F to the charging force f which is the rotational force of the charged member A is improved,
The amount of charging power as a whole can be reduced. As described above, in the present embodiment, the operating angle of the front blade driving lever 16 which is a charged member is maintained while maintaining the operating angle of the front blade operating lever 15 which is a member connected to the front blade 1 as before. Can be reduced, the transmission efficiency of transmitting the rotational force of the set cam 37 to the front blade drive lever 16 in the initial charging operation is improved, and similarly, the member connected to the rear blade 2 Since it is possible to narrow the operating angle of the rear blade drive lever 26, which is the charged member, while maintaining the operating angle itself of a certain rear blade operating lever 25 as before, the rotation of the set cam 37 in the initial charging operation is performed. The transmission efficiency when transmitting the force to the rear blade drive lever 26 is also improved, and it is possible to reduce the charging force as a whole.

【effect】

As described above, according to the present invention, the operating angle of the driving member biased by the driving spring is reduced while the operating angle of the operating member directly connected to the shutter blade is secured. Therefore, the transmission efficiency of the charging force in the initial charging operation is improved, and the amount of the charging force can be reduced. The operating member connected to the shutter blade is urged by the driving spring via the driving member in the first half region of the traveling operation, but after the driving member reaches the forward limit, the urging force is changed. , And the vehicle coasts by the inertial force, so that the shock and the operating noise generated at the end of traveling in the forward direction are also reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the basic principle of the present invention, FIG. 2 is a plan view of a blade peripheral mechanism of a focal plane shutter according to one embodiment of the present invention, and FIG. 3 is a drive according to one embodiment of the present invention. FIG. 4 is a plan view showing a state immediately before the start of traveling of the front blade in the mechanism; FIG. 4 is a plan view showing a state before the rear blade starts traveling while the front blade of the mechanism shown in FIG. 3 ends traveling; FIG. 5 is a plan view showing a state in which the rear blade of the mechanism shown in FIGS. 3 and 4 has finished traveling. 1 front blade 1a 1b 1c 1d blade 2 rear blade 2a 2b 2c 2d blade 3, 4, 5, 6 connecting lever 7 main plate, 7a aperture 7b, 7c Slot, 10 Front blade drive pin 13 Rear blade drive pin, 15 Front blade operating lever 15a Vertical section, 15b Contact surface 16 Front blade drive lever 16a … Arm, 16c… Contact surface 18… Front blade braking spring 18b… Arm, 19… Torsion spring 22… Locking lever, 23… Stopper 25… Rear wing operating lever 25a… Pin 25b Contact surface 26 Rear blade drive lever 26a Arm 26c Contact surface 28 Rear blade braking spring 28b Arm 29 Torsion spring 32 Lock lever 33 … Stopper 34 …… Set lever, 36 …… Set link 37 …… Set cam 41 …… Front blade bound stopper

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03B 9/36

Claims (1)

(57) [Claims] 1. A method according to claim 1, further comprising the step of: releasing a charged front blade driving spring to cause the front blade group, which is in a state of blocking the exposure aperture, to travel in a direction in which the exposure aperture is opened; By releasing the charged rear blade driving spring at a desired time difference from the timing at which the blade driving spring is released, the rear blade group in a state where the exposure aperture is opened is released. In a focal plane shutter adapted to run in a direction in which the exposure aperture is shielded, each of the blade groups is connected to each of the blade groups, and each of the corresponding blade groups is moved forward by the reciprocating operation. Operating members for operating in the forward and backward directions, and biased by the respective driving springs, A driving member having an engaging portion for engaging each corresponding operating member from the retreat direction to the forward direction, wherein each of the driving members is such that the corresponding operating member has a forward limit. A focal plane shutter characterized in that its own advance limit is regulated so that the advance operation is completed before the movement reaches.