JPH10319473A - Focal-plane shutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a strong focal-plane shutter for a camera having simple constitution and capable of detecting the abnormal operation of a rear blade driving member. SOLUTION: A front blade driving member 8 has the operation pin 8e of a front blade group. A rear blade operating member 11 pressed and operated by the rear blade driving member 12 has the operation pin 11c of a rear blade group. The respective driving members 8 and 12 are held at exposure operation starting positions against their driving springs by the magnetic force of their electromagnets. A mediate member 15 is energized counterclockwise. When the holding power of the member 12 by the electromagnet is not obtained, the member 12 rotates, its projecting part 12d presses the bent part 15a of the member 15, and d bent part 15d presses the member 8. The member 8 is separated from the electromagnet and travels by the force of two driving springs, then a switch is operated by a pressing pin 8c so as to give the warning of the abnormal operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focal plane for a camera in which a group of front blades and a group of rear blades are sequentially operated upon photographing, and a film is exposed by slits formed by the slit forming blades. Related to the shutter.

[0002]

2. Description of the Related Art Recent focal plane shutters include:
Broadly speaking, there are a so-called direct type focal plane shutter and a locking type focal plane shutter. In each case, each blade group is operated by each driving member, and the operation of those driving members is performed. The starting time is controlled by each electromagnet. Then, when photographing, when the camera is released, power is supplied to both electromagnets in the initial stage, and then, when the mirror-up and the operation of the AF device are completed, the power supply to each electromagnet is sequentially cut off. The driving members can perform the exposure operation by respective driving springs.

Therefore, in such a focal plane shutter, the coil of the electromagnet is not energized due to disconnection or the like, the battery is exhausted, the attracting surface of the electromagnet has dust or dirt, and the assembly accuracy is poor. The required electromagnet adsorption action cannot be obtained,
Each drive member may be activated without waiting for a proper operation timing. Therefore, conventionally, various measures have been taken to ensure that such abnormal operation can be detected not only when the camera is used but also when the camera is manufactured. One example is disclosed in JP-A-8-304.
No. 876 discloses this.

According to this conventional example, when the attraction action of the electromagnet for the front blade is not sufficient and the driving member for the front blade is operated early, the flash switch is operated earlier than a predetermined timing. Is used to detect abnormal operation.If the attracting action of the electromagnets for the rear blade is not sufficient and the driving member for the rear blade operates early, multiple rear blades are pivoted. A part of the arm that is pushing pushes a part (opening lever pin) of the leading blade drive member and forcibly activates the leading blade drive member, thereby detecting abnormal operation in the same manner as described above. I have.

[0005]

However, in the above-mentioned conventional example, there is no problem when detecting an abnormal operation of the driving member for the front blade, but there is a problem when detecting an abnormal operation of the driving member for the rear blade. is there. That is, the arm supporting the plurality of blades is usually made of a very thin flexible material in order to reduce the load and enable high-speed operation, and to prevent light leakage and space. Have been. Therefore, it is almost impossible to operate the entire arm on a predetermined plane. In fact, to date more or less products,
Arms are known to bend. Therefore, when the arm is provided with a long protruding engaging portion as in the above-described conventional example, the engaging portion collides with the blades or arms of the front blade group in normal operation. Although it is impossible, even if the arm can be manufactured so as to operate on a predetermined plane, a thin flexible engaging portion is a part of a rigid front blade driving member. Therefore, there is a high possibility that the arm is destroyed or the pivot of the blade is destroyed.

The present invention has been made in order to solve such a problem, and an object of the present invention is to use an arm made of a thin material as in the above-described conventional example. An object of the present invention is to provide a focal plane shutter capable of detecting an abnormal operation without any trouble when a rear blade drive member operates earlier than a normal timing.

[0007]

In order to achieve the above object, a focal plane shutter according to the present invention comprises a driving spring for a front blade at the time of exposing operation, the group of front blades comprising a plurality of blades supported by a plurality of arms. A driving member for the front blade to be actuated by being biased to the front, an electromagnet for the front blade to enable the driving member for the front blade at the exposure operation start position to be activated at a predetermined time, and a plurality of arms for the plurality of blades. The rear blade drive member actuated by being urged by the rear blade drive spring at the time of exposure operation, and the rear blade drive member at the exposure operation start position at a predetermined time A rear blade electromagnet for enabling operation, a first engagement portion and a second engagement portion, wherein the first engagement portion is pushed by the front blade drive member at the end stage of the set operation, and the second engagement portion is pushed.
An intermediary member for causing the engaging portion to face an operation locus of the rear blade drive member; and a detection unit capable of detecting an exposure operation of the front blade group or the front blade drive member, wherein the front blade drive member is provided. When the rear blade driving member is actuated by the rear blade driving spring when the is at the exposure operation start position, the front blade driving member is forcibly activated via the intermediary member. In order to achieve the above object, the focal plane shutter according to the present invention is configured such that a front blade group formed by supporting a plurality of blades with a plurality of arms is biased by a driving blade driving spring during an exposure operation. A front blade driving member to be operated, a front blade electromagnet for enabling the front blade driving member at the exposure operation start position to be operable at a predetermined time, and a rear blade formed by supporting a plurality of blades with a plurality of arms. A rear blade operating member for operating the group, a rear blade driving member biased by a rear blade driving spring during an exposure operation to push the front blade operating member, and the rear blade at an exposure operation start position A rear blade electromagnet for enabling the driving member for operation at a predetermined time; a spring stretched between the rear blade operating member and the rear blade driving member; and Blade drive A first engaging portion and a second engaging portion for preventing the following member from following the material, and when the first engaging portion is pushed by the leading blade driving member at the end of setting, (2) an intermediary member for causing the engaging portion to face the operation trajectory of the rear blade drive member and releasing the suppression of the rear blade operation member, and operating each drive member from the initial position to drive each of the drive members A set which is operated to a set position against a spring, and in the end stage of the set, the actuating member for the rear blade is suppressed in place of the suppressing portion, and the restraint is released in an initial stage of a photographing operation to return to the initial position. Member, and a detecting means capable of detecting an exposure operation of the front blade group or the front blade drive member, wherein the rear blade drive member is connected to the rear blade drive member when the front blade drive member is at the exposure operation start position. Operated by blade drive spring Kiniwa, so as forcibly operating the leading blade driving member via the intermediary member. Furthermore,
In each of the focal plane shutters described above, preferably, the intermediate member is urged to rotate in one direction by a spring, and is rotated against the urging force of the spring at the time of setting. When the driving member starts the exposure operation, the driving member returns by the urging force of the spring.

[0008]

1 to 6 show an embodiment of the present invention.
This will be described with reference to the embodiment shown in FIG. In this embodiment, the present invention is applied to a focal plane shutter having a double light shielding function, and is configured as a direct type shutter among the above two types. FIG. 1 is a plan view showing a main configuration in a state immediately after the end of the exposure operation. 2 to 6 show the operation states of some of the components shown in FIG. 1, FIG. 2 shows a state immediately after the end of the exposure operation, and FIG. 3 shows a set state. 4 shows a state immediately before the start of the exposure operation, FIG. 5 shows a state in which the driving member for the rear blade has started to operate before the start of the exposure operation of the driving member for the front blade, and FIG. 6 shows a driving state for the front blade by the driving member for the rear blade. Each state immediately after the member was operated is shown.

First, the configuration of this embodiment will be described. An opening 1a is formed substantially at the center of the shutter base plate 1, and each drawing shows a substantially left half thereof. On the back side of the shutter base plate 1, an intermediate plate and an auxiliary base plate (not shown) are sequentially attached at a predetermined interval, as is well known. An opening having a shape similar to that of the opening 1a is also formed in the intermediate plate and the auxiliary base plate, and a rectangular exposure opening as a shutter unit is determined by combining these three openings. Has become. In the case of this embodiment, a front blade group is arranged between the shutter base plate 1 and the intermediate plate, and a rear blade group is arranged between the intermediate plate and the auxiliary base plate.

On the front side of the shutter base plate 1, shafts 1b, 1
c, 1d are erected. Of which axes 1b and 1c
It also protrudes to the back side of the shutter base plate 1, and the portion is formed thin. In FIG. 1, the portion is shown by a broken line. On the back side of the shutter base plate 1, shafts 1e and 1f are erected. Further, as shown in FIG. 2, the shutter base plate 1 has circular holes 1g, 1h, and 1i.
And a circular hole 1j are formed. Although not shown because it is well known, a cushioning member made of an elastic material such as butyl rubber having a C-shaped planar shape is attached to the upper end positions of the arc-shaped holes 1g and 1h.

The front blade group is disposed on the rear side of the shutter base plate 1 as described above, and includes two arms 2 and 3 shown in FIG. Although it is composed of blades, FIG. 1 shows only the slit forming blades 4 among those blades. And
The arms 2 and 3 are pivotally attached to the shafts 1b and 1e, and the arm 2 has a long hole 2a. On the other hand,
The rear blade group has a similar configuration, and is composed of two arms 5, 6 pivotally attached to the shafts 1c, 1f and a plurality of blades pivotally supported by them. 1, only the slit forming blades 7 are shown. The arm 5 has a long hole 5a.

A front blade driving member 8 made of synthetic resin is rotatably mounted on the shaft 1b on the front side of the shutter base plate 1. The driving member 8 for the front blade includes a shaft 1
b, a pressed portion 8b and a pushed portion 8b are formed, and a pushing pin 8c and a mounting portion 8d are formed on the surface side,
An operating pin 8e is formed on the back side. A thin portion 8f is formed near the mounting portion 8d. The operating pin 8e passes through the arc-shaped hole 1g, and
In the hole 2a. Although not shown because it is well known, the leading blade drive member 8 is urged in a counterclockwise direction by a leading blade drive spring. Therefore, when the leading blade driving member 8 is rotated in the counterclockwise direction by the leading blade driving spring, the arms 2 and 3 also rotate in the counterclockwise direction to overlap a plurality of blades, and conversely, the leading blades When the arm is rotated clockwise against the driving spring, the arms 2 and 3 are rotated clockwise to deploy the plurality of blades.

Although shown only in FIG. 2 and omitted in the other drawings, an iron piece member 9 is mounted on the mounting portion 8d of the driving member 8 for the leading blade. FIG.
In order to make the mounting structure easy to understand,
Although only d is shown in cross section, the iron piece member 9 is
a, a shaft portion 9b, and a flange portion 9c, and are attached via a compression spring 10. Therefore, this iron piece member 9
When the iron piece portion 9a is pushed, it is possible to act to the left with respect to the mounting portion 8d against the urging force of the compression spring 10.

On the other hand, a rear blade operating member 11 and a rear blade driving member 12 made of synthetic resin are rotatably mounted on the shaft 1c on the front side of the shutter base plate 1. The rear blade operating member 11 attached to the shutter base plate 1 side is provided with two arms, one end of which has an engaging portion 11a, and the other end of which has an engaging portion 11a. Is formed with a pushed portion 11b and an operating pin 11c.
Of these, the operating pin 11c is provided with the above-described arc-shaped hole 1h.
And fitted into the hole 5 a of the arm 5. Also, the rear blade drive member 12 has a cylindrical portion 12 fitted to the shaft 1c.
a, a pushed portion 12b, a mounting portion 12c, a protruding portion 12d, and a pin 12e. This rear blade drive member 12
The back surface is formed in two parallel planes with the pushed portion 12b as a boundary, and the thickness on the mounting portion 12c side is reduced.

A spring (not shown) is stretched between the rear blade operating member 11 made of a synthetic resin and the rear blade driving member 12, and the rear blade operating member 11 is rotated clockwise. The driving member 12 is urged in a counterclockwise direction. Therefore, in a state where only the urging force is acting on both, the pushed portion 11b of the rear blade operating member 11 and the pin 12e of the rear blade drive member 12 are in contact with each other. Further, as shown in FIG. 2 only, the iron piece member 13 is attached to the attachment portion 12c of the rear blade drive member 12. The iron piece member 13 also has an iron piece portion 13a, a shaft portion 13b,
It is composed of a flange 13c and is attached via a compression spring 14.

Further, the rear blade drive member 12 is urged counterclockwise by a rear blade drive spring (not shown). Therefore, when the rear blade drive member 12 is rotated counterclockwise by the rear blade drive spring, the pin 12e pushes the pushed portion 11b to rotate the rear blade operating member 11 counterclockwise. As a result, the operating pin 11c rotates the arms 5 and 6 counterclockwise to deploy the plurality of blades. On the other hand, when the driving member 12 for the rear blade is rotated clockwise against the driving spring for the rear blade, the spring tensioned between the operating member 11 for the rear blade and the driving member 12 for the rear blade. The biasing force makes the rear blade operating member 11 rotatable clockwise, and when rotated by the biasing force, the operating pin 11c rotates the arms 5 and 6 clockwise to move the plurality of blades. It is designed to be superimposed.

An intermediate member 15 and a set member 16 are attached to the shaft 1d of the shutter base plate 1 from the shutter base plate 1 side. At least the set member 16 is made of synthetic resin. The intermediate member 15 has four bent portions 15a,
15b, 15c, and 15d, which are urged counterclockwise by a spring (not shown).
5c is inserted into a circular hole 1j formed in the shutter base plate 1, and its rotation range is regulated. Also,
The bent portion 15a is configured so as to be able to face within the operation locus of the protrusion 12d of the rear blade drive member 12, and the bent portion 15b
Can be located within the operating locus of the engaging portion 11a of the operating member 11 for the rear blade. Further, the bent portion 15d is
The front lobe drive member 8 is configured to be able to face the operating locus of the tip of the thin portion 8f.

The set member 16 includes a cylindrical portion 16a fitted on the shaft 1d, a pushing portion 16b for pushing the pushed portion 8b of the leading blade driving member 8, and a pushing portion 16b for pushing the trailing blade driving member 12. Part 12
b, a pushing portion 16c, an overhang 16d, and an overhang 16
An overhang 16e thicker than d is formed. On the back side of the set member 16, the rear blade operating member 1 is provided.
Suppressing portion 16f that can be seen within the operating locus of the first engaging portion 11a
And a pin 16g (FIG. 2) inserted into an arc-shaped hole 1i formed in the shutter base plate 1. The set member 16 is urged by a spring (not shown) so as to rotate clockwise, and the rotation is caused by the pin 16g contacting the end face of the hole 1i as shown in FIG. It is to be stopped. This position of the set member 16 is hereinafter referred to as an initial position.

A support plate and a printed wiring board are attached to the ends of the shafts 1b, 1c and 1d so as to be parallel to the shutter base plate 1. Figure 1
In FIG. 2, a support plate 17 arranged on the shutter base plate 1 side is indicated by a dashed line and substantially rectangular. Two flexible contact members 18 and 19 attached to a printed wiring board (not shown) are also indicated by dashed lines. Although these contact members 18 and 19 are not clear from FIG.
The support plate 17 enters the shutter base plate 1 through a notch formed on the edge thereof. And the contact member 19
Are located within the operating locus of the push pin 8c formed on the leading blade drive member 8, contact the contact member 18 by being pushed by the push pin 8c, and emit a signal.

Although not shown because it is well known, the supporting plate 17 is provided with an electromagnet for the front blade and an electromagnet for the rear blade between the shutter base plate 1 and the coil described above. It is electrically connected to the printed wiring board. Each electromagnet is provided with an iron core member, and when the coil is energized, it attracts the iron piece portions 9a and 13a of the iron piece members 9 and 13 provided on the drive members 8 and 12, respectively. , 12 can be held at the exposure operation start position against the force of the drive spring urging the counterclockwise direction.

Next, the operation of this embodiment will be described. First, a case where a normal operation is performed will be described mainly with reference to FIGS. 1 and 2 show the state immediately after the end of the exposure operation. In this state,
The front blade drive member 8 is rotated counterclockwise by the front blade drive spring, and the operating pin 8e abuts on a buffer member (not shown) attached to the upper end of the hole 1g of the shutter base plate 1, Has been stopped. Therefore, the blades of the front blade group are superimposed and stored at a position above the opening 1a, and the contact member 19 is pushed by the pushing pin 8c of the front blade drive member 8 and contacts the contact member 18. doing.

The rear blade drive member 12 is rotated counterclockwise by a rear blade drive spring.
The pushed portion 11b is pushed by 2e to rotate the rear blade operating member 11 counterclockwise. The operating pin 11c of the operating member 11 for the rear blade is in contact with a buffer member (not shown) attached to the upper end of the hole 1h.
Therefore, the blades of the rear blade group are deployed, and the opening 1
a. The intermediate member 15 is at a position rotated counterclockwise by a spring (not shown), and has a bent portion 15b and an engaging portion 11a of the rear blade operating member 11.
To prevent the rear blade operating member 11 from rotating clockwise. Further, the set member 16
Is stopped at the initial position.

When the film is wound in such an exposure operation ending state, the member on the camera body side pushes the projecting portion 16e of the set member 16 upward from the lower side in the figure in conjunction with the winding of the film. Is rotated counterclockwise against a spring (not shown). In this rotation, first, the pushing member 16b pushes the pushed portion 8b, and the set member 16 rotates the leading blade driving member 8 clockwise against the leading blade driving spring (not shown). To go.
Therefore, the operating pin 8e of the leading blade driving member 8 rotates the arm 2 clockwise, and the plurality of blades of the leading blade group are deployed downward with the slit forming blade 4 at the top.

When the overlap between the slit forming blades 4 of the front blade group and the slit forming blades 7 of the rear blade group reaches a predetermined amount,
Further, the pushing portion 16c of the set member 16 starts pushing the pushed portion 12b of the rear blade drive member 12, and at almost the same time, the pushing by the pushing pin 8c is released, and the contact member 1 is released.
8, 19 contacts are released. Thereafter, the rear blade drive member 12 continues to rotate clockwise against a rear blade drive spring (not shown), but the rear blade operating member 11 Since it is engaged with the 15 bent portion 15b, it cannot rotate clockwise, and the blades of the rear blade group remain covering the opening 1a.

At the final stage of clockwise rotation, the leading blade driving member 8 pushes the bent portion 15d of the intermediate member 15 with the tip of the thin portion 8f, and the iron piece portion 9a of the iron piece member 9 is shown. To the iron core member of the electromagnet for the leading blade that has not been made. When the bent portion 15d is pushed, the intermediate member 15 is rotated clockwise against a spring (not shown). Therefore, the locking by the bent portion 15b is released, and the rear blade operating member 11 rotates clockwise by the force of the spring stretched between the rear blade driving member 12 and the rear blade driving member 12, but the rotation is slightly increased. Just by rotating, the engaging portion 11a comes into contact with the restraining portion 16f of the set member 16 and is stopped. Accordingly, in this state, the upper edge of the slit forming blade 7 of the rear blade group, that is, the slit forming edge does not enter the exposure opening.

The driving member 8 for the leading blade can be used for the compression spring 1 even after the iron piece portion 9a of the iron piece member 9 comes into contact with the iron core member of the electromagnet.
Slightly rotated while straining 0. for that reason,
The iron piece portion 13a of the iron piece member 13 provided on the rear blade drive member 12 comes into contact with the iron core member of the rear blade electromagnet. When the compression spring 14 is slightly tensioned, the rotation of the set member 16 is stopped. This state is the setting completion state, and this state is maintained by the member on the camera body side until the next photographing is performed. At this time, since the exposure aperture is covered by the front blade group and the rear blade group, and is in a so-called double light blocking state, it is possible to prevent light leakage between the blades when the camera is not used. Become.

When the release button of the camera is pressed, in the initial stage, first, the coils of the electromagnets for the front blade and the rear blade are energized, and the iron pieces 9a, 13a of the iron members 9, 13 are magnetically attracted. Is done. Iron piece members 9 and 13
Next, when the member on the camera main body side is retreated downward from the overhang portion 16e of the set member 16 at the stage where is completely sucked, the set member 16 follows by a spring (not shown), Rotate in the direction. If the camera has not been used for a long time, the set member 16 may be made of synthetic resin, so that the frictional portion may have an adhesive action and may not immediately follow, but in this case, the camera body side The member pushes the overhang 16d to promote clockwise rotation.

As described above, when the setting member 16 rotates clockwise, in the initial stage, the driving members 8 and 12 are slightly rotated counterclockwise by the driving springs (not shown). Due to this rotation, the tension of the compression springs 10 and 14 is released, and the driving members 8 and 12 have their mounting portions 8d and 12c applied to the flanges 9c and 13c of the iron piece members 9 and 13. Stop by touching. This state is the exposure operation start position of each of the driving members 8 and 12, and also the exposure operation start position for the front blade group. At this time, each electromagnet resists the force of each drive spring,
This state is maintained only by the magnetic force.

By the subsequent rotation of the setting member 16,
The restraining portion 16f of the setting member 16 is the rear blade operating member 11
Of the rear blade actuating member 11
Is rapidly rotated clockwise by a spring (not shown) stretched between the driven member 12 and the driven member 1.
1b stops when it comes into contact with the pin 12e. Further, by such clockwise rotation, the rear blade operating member 11 causes the arm 5 to rotate clockwise by the operating pin 11c so that the blades of the rear blade group are overlapped at a position below the opening 1a and stored. Let it be in a state. Such a storage position of the rear blade group is an exposure operation start position for the rear blade group, whereby all the driving members 8 and 12 and each blade group are placed at the exposure operation start position. become. Thereafter, the setting member 16 returns to the initial position, and all the members are in the state shown in FIG.

Next, when the power to the electromagnet for the front blade is cut off, the electromagnet loses its holding force, and the driving member 8 for the front blade is rotated counterclockwise by the driving spring for the front blade. In the initial stage, the pressing force on the bent portion 15d is released, so that the intermediate member 15 is rotated counterclockwise by a spring (not shown) and returns to the state shown in FIGS. The driving member 8 for the front blade then rapidly rotates in the counterclockwise direction, rotates the arm 2 by the operating pin 8e, superimposes the blades of the front blade group upward, and opens the exposure opening.

Then, immediately before the exposure opening is fully opened,
The push pin 8c pushes the contact member 19 into contact with the contact member 18. At this time, if the camera has been set to the flash mode in advance, the flash device operates in response to the closing signals of the contact members 18 and 19, so that the flash light can be suitably obtained when the exposure opening is fully opened. It has become. Immediately after the leading blade group fully opens the exposure opening, the leading blade driving member 8 causes the impact pin 8e to come into contact with a buffer member (not shown) attached to the upper end of the hole 1g. Power is absorbed and stops.

In the case of this embodiment, since the push pin 8c pushes the contact member 19, the contact member 19
However, it also acts as a braking means for the leading blade drive member 8. Therefore, in order to prevent the leading blade driving member 8 from bouncing, which causes uneven exposure, it is only necessary to provide the above-mentioned buffering member. Since various means are known, such as arranging at a position where the
They can be selectively adopted.

After a predetermined time after the energization of the electromagnet for the front blade is stopped, the energization of the electromagnet for the rear blade is cut off, and the driving member 12 for the rear blade is driven by a driving spring for the rear blade (not shown). Is rapidly rotated counterclockwise. At this time, the rear blade operating member 11 is also pushed by the pin 12e and rotated counterclockwise, and the arm 5 is rotated by the operating pin 11c. Therefore, the blades of the rear blade group are spread upward and cover the exposure opening. After closing the exposure opening, the operating pin 11c comes into contact with a buffer member (not shown) attached to the upper end of the hole 1h, and the elasticity of the operating pin 11c dampens and absorbs the impact force.

On the other hand, as described above, the operating pin 11c
Before and after contact with the cushioning member attached to the upper end of the hole 1h, the engaging portion 11a of the rear blade operating member 11 pushes the bent portion 15b and resists a spring (not shown). The intermediate member 15 is rotated clockwise. Thereafter, the intermediary member 15 returns in the counterclockwise direction and prevents the rear blade operating member 11 from rotating clockwise. For this reason, the rear blade operating member 11 is prevented from bouncing to cause uneven exposure, and is reliably stopped. The state is shown in FIGS.
The state shown in FIG.

In this embodiment, in order to prevent the rear blade operating member 11 from bouncing, both the bent portion 15b of the intermediate member 15 and the cushioning member attached to the upper end of the hole 1h are involved. However, this is because before the intermediary member 15 returns to the engagement position of the engagement portion 11a, the rear blade operating member 11 bounces, and the engagement portion 11a passes through the engagement position. This is to prevent such things from happening. That is, in the case of the configuration as in the present embodiment, the braking by the buffer member delays the bouncing timing of the operating member 11 for the rear wing. And the engaging portion 11a can be securely locked. However, in actual production, various conditions are different depending on the specification, for example, the biasing force of the driving spring for the rear blade is different, so that such a configuration is not always adopted.

Next, a case where the leading blade driving member 8 and the trailing blade driving member 12 perform an abnormal operation will be described. Since all of these abnormal operations are due to poor adsorption by the respective electromagnets, in practice, only the front blade driving member 8 performs the abnormal operation and the rear blade driving member 12
Only the case where only the abnormal operation is performed, and the case where both the front blade driving member 8 and the rear blade driving member 12 perform the abnormal operation, may be understood from the following description in the case of the present embodiment. In the case where both operate abnormally, the detection method is
Since it is substantially the same as the case where only the leading blade drive member 8 performs an abnormal operation, in the following description, the leading blade drive member 8 and the rear blade drive member 12 are each independently operated abnormally. Will be described.

First, a case where only the leading blade drive member 8 performs an abnormal operation will be described mainly with reference to FIG. FIG.
Indicates the set state as described above. In this state, the front blade drive member 8 and the rear blade drive member 12 are prevented from rotating counterclockwise by the pushing portions 16b and 16c of the set member 16. Therefore,
When the release button of the camera is pressed, in the initial stage, if normal, the coils of the electromagnets for the front blade and the rear blade are energized, and the iron piece 9 of the iron pieces 9 and 13 is turned on.
a and 13a are attracted by a sufficiently large magnetic force. However, when the coil of the electromagnet for the leading blade is disconnected, the iron piece 9a is not adsorbed at all,
There is dust between the iron core member of the electromagnet for the leading blade and the iron piece 9a, the contact surface of each is damaged, or the set member 16
If the set amount of the leading blade drive member 8 is insufficient, the magnetic force acting on the iron piece portion 9a is small, and a state where a sufficient attraction force is not obtained.

In this state, when the member on the camera body side retreats downward from the overhang portion 16e of the set member 16 and the set member 16 rotates clockwise following it, In the initial stage, each of the driving members 8 and 12 is slightly rotated counterclockwise by each of the driving springs (not shown) to reach the exposure operation start position. Thereafter, when the set member 16 further rotates clockwise,
Since the magnetic force of the rear-wing electromagnet is sufficiently acting, the rear-wing driving member 12 is held at the exposure start position.

However, since the magnetic force of the electromagnet for the front blade does not act on the iron portion 13a of the iron plate member 13 at all or does not act sufficiently, the front blade rotated by the driving spring for the front blade is used. Drive member 8 cannot be held at the exposure operation start position. Therefore, the leading blade driving member 8 rotates counterclockwise following the clockwise rotation of the set member 16. In the process, as described above, since the restraining portion 16f of the set member 16 releases the restraint of the rear blade operating member 11, the rear blade operating member 11 rotates clockwise, and each blade of the rear blade group is It is superimposed on a position below the opening 1a. On the other hand, the leading blade group is actuated by the leading blade driving member 8, and the respective blades are superimposed on the position above the opening 1a.

The driving member 8 for the leading blade is thus rotated in the counterclockwise direction, and before the set member 16 reaches or reaches the initial position, the contact member 19 is pushed by the pushing pin 8c. 18. However, since this contact signal is issued at a timing earlier than the time when the energization to the coil of the leading blade electromagnet is cut off when the normal exposure operation is performed, the control circuit uses this signal as a synchronization signal of flash emission. Without determining, it is determined that the signal is an abnormal operation signal, and the warning device is activated.

Next, a case where only the rear blade drive member 12 performs an abnormal operation will be described mainly with reference to FIGS. 3, 5, and 6. FIG. In the set state of FIG. 3, as described above, the intermediate member 15 pushes the bent portion 15 d at the tip of the thin portion 8 f of the leading blade drive member 8 and opposes a spring (not shown). It is rotated clockwise. Therefore,
In this state, the bent portion 15a of the intermediate member 15 is
This means that it is present in the operation locus of the protrusion 12d of the rear blade beating member 12. In this setting state, when the release button of the camera is pressed, in the initial stage, the iron piece member 9 of the driving member 8 for the front blade is attracted to the iron core member of the electromagnet for the front blade by a sufficient magnetic force. The iron piece member 13a of the blade driving member 12 is in a state of not being attracted to the iron core member of the rear blade electromagnet at all, or being not attracted by a sufficient force, for the reasons already described.

Thereafter, when the set member 16 rotates clockwise following the member on the camera body side, in the initial stage, the respective drive members 8 and 12 are rotated counterclockwise by respective drive springs (not shown). The exposure operation is started. When the set member 16 is further rotated, the leading blade drive member 8 remains held at the exposure operation start position, but the trailing blade drive member 12 is not held at the exposure operation start position, and is rotated by the trailing blade drive spring. Then, it follows the rotation of the set member 16. In the process, since the inhibiting portion 16f of the set member 16 releases the inhibition of the rear blade operating member 11, the rear blade operating member 11 rotates clockwise, and the respective blades of the rear blade group are superimposed. After the pushed portion 11b comes into contact with the pin 12e of the rear blade drive member 12, it is rotated counterclockwise by the rear blade drive member 12 to expand each blade of the rear blade group upward. Will be.

In the final stage of the counterclockwise rotation, the rear blade drive member 12 pushes the bent portion 15a with the projection 12d, and pushes the intermediate member 15 counterclockwise against a spring (not shown). Rotate. As a result, the bent portion 15d of the intermediate member 15 pushes the tip of the thin portion 8f of the leading blade drive member 8. FIG. 5 shows a state in which the protrusion 12d comes into contact with the bent portion 15a and starts to be pushed. At this time, the leading blade drive member 8 is held by the leading blade electromagnet as described above. However, since the intermediate member 15 has a predetermined rigidity, the force of the rear blade drive spring at this time is reduced by the force of the front blade drive member 8.
Will join.

Therefore, the driving force for the front blade, which urges the driving member 8 for the front blade, cannot overcome the holding force of the electromagnet for the front blade by its own force, but the force of the driving spring for the rear blade is applied. As a result, it is possible to overcome and start to rotate counterclockwise. The state immediately after the start of the rotation is shown in FIG. In the state of FIG. 6, the rear blade drive member 12 has already stopped, and the blades of the rear blade group are in an expanded state and cover the exposure opening. On the other hand, the leading blade group is operated by the subsequent rotation of the leading blade driving member 8, and the respective blades are superimposed upward.

When the rotation of the leading blade driving member 8 is at the final stage, the push pin 8c pushes the contact member 19 to make contact with the contact member 18. However, as described above, since the contact signal is issued at a timing earlier than the time when the energization of the coil of the leading blade electromagnet is cut off when the normal exposure operation is performed, the control circuit abnormally operates the signal. The signal is determined and the warning device is activated. Thereafter, in the same manner as in the case where the normal exposure operation described above is performed, the driving member 8 for the front blade is stopped, and each component is in the state shown in FIG.

In the above embodiment, the intermediate member is biased by a spring so as to rotate in one direction. However, if the intermediate member does not serve as a bounce prevention member, such a spring may be used. Is not necessary. However, in such a case, if the position of the intermediate member is not stable, an appropriate frictional resistance force may be applied to the rotation of the intermediate member by a leaf spring or the like. In the above-described embodiment, in the set state, the exposure opening is covered by both the blades of the front blade group and the rear blade group.
Although the present invention is applied to a so-called double light-blocking focal plane shutter, the present invention is basically constituted by the relationship between each driving member and the intermediate member. Without the rear blade operating member in
It goes without saying that the present invention can also be applied to a standard type focal plane shutter in which the rear blade drive member directly operates the rear blade group.

Further, in the above embodiment, the present invention is applied to a so-called direct-type focal plane shutter in which each driving member is held by the magnetic force of each electromagnet at the exposure operation start position. However, as described above, the present invention is basically configured by each driving member and the mediation member, so that each driving member is moved by the respective locking member at the exposure operation start position. The present invention is also applied to a so-called locking type focal plane shutter in which locking is performed and the locking is sequentially released by two members (referred to as iron piece levers) released by each electromagnet. It is possible to In the case of a locking type focal plane shutter, it is often the case that the set member is immediately returned to the initial position after the setting operation. Some are restored at the stage. Therefore, the above-described configuration for double light shielding can be applied to the case where the present invention is applied to a locking type focal plane shutter, and the same applies to the bounce prevention function.

[0048]

As described above, according to the present invention, the rigid intermediary member having the first engagement portion and the second engagement portion is provided, and the first engagement portion is first set at the end stage of the set operation. Since the second engaging portion is made to face the operating locus of the rear blade drive member by being pushed by the blade drive member, the second engagement portion is made of a thin material and is operated in a narrow space. It is possible to detect the abnormal operation of the rear blade drive member without any trouble. In addition, by providing the intervening member and the set member with the restraining portion, it is possible to apply the present invention to a double light-blocking shutter. Further, it is possible to prevent the rear blade group from bouncing by applying an urging force to the intermediate member so as to move the second engagement portion out of the operation locus of the rear blade driving member. Become.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main configuration of an embodiment.

FIG. 2 is a plan view showing some components shown in FIG. 1 and shows a state immediately after an exposure operation is completed.

FIG. 3 is a plan view showing a set state of the embodiment.

FIG. 4 is a plan view showing a state immediately before the start of an exposure operation according to the embodiment.

FIG. 5 is a plan view showing a state in which the rear blade driving member starts operating before the exposure operation of the front blade driving member starts in the embodiment.

FIG. 6 is a plan view showing a state immediately after the driving member for the front blade is operated by the driving member for the rear blade in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shutter base plate 1a Openings 1b, 1c, 1d, 1e, 1f Shafts 1g, 1h, 1i, 2j, 2a, 5a Holes 2, 3, 5, 6 Arms 4, 7 Slit forming blade 8 Front blade driving member 8a, 12a, 16a Cylindrical portion 8b, 11b, 12b Pushed portion 8c Pushing pin 8d, 12c Mounting portion 8e, 11c Operating pin 8f Thin portion 9, 13 Iron piece member 9a, 13a Iron piece 9b, 13b Shaft portion 9c, 13c Flange Unit 10, 14 Compression spring 11 Rear blade operating member 11a Engagement unit 12 Rear blade driving member 12d Projection 12e, 16g Pin 15 Intermediate member 15a, 15b, 15c, 15d Bending unit 16 Set member 16b, 16c Pushing Part 16d, 16e Overhanging part 16f Suppression part 17 Support plate 18, 19 Contact member

Claims (3)

[Claims] A first blade driving member which is actuated by being urged by a first blade driving spring at the time of an exposure operation, the first blade driving member comprising a plurality of blades supported by a plurality of arms; An electromagnet for the front blade, which makes the certain front blade driving member operable at a predetermined time, and a rear blade group including a plurality of blades supported by a plurality of arms are urged by the rear blade drive spring during the exposure operation. , A rear blade electromagnet for activating the rear blade drive member at the exposure start position at a predetermined time, a first engaging portion and a second engaging portion. And an intermediary member having a first engaging portion pushed by the leading blade driving member at the end stage of the set operation and causing the second engaging portion to face the operating locus of the rear blade driving member. Dew of the leading blade group or the leading blade driving member Detecting means capable of detecting light operation, when the rear blade drive member is operated by the rear blade drive spring when the front blade drive member is at the exposure operation start position, via the intermediary member A focal plane shutter, wherein the leading blade driving member is forcibly operated. 2. A front blade driving member which is operated by being urged by a front blade driving spring at the time of an exposure operation to a front blade group comprising a plurality of blades supported by a plurality of arms, and an exposure operation start position. An electromagnet for the front blade that makes the certain driving member for the front blade operable at a predetermined timing, an operating member for the rear blade that operates a rear blade group including a plurality of blades supported by a plurality of arms, and an exposure operation. A rear blade drive member that is urged by a rear blade drive spring to push the front blade operation member, and a rear blade that enables the rear blade drive member at the exposure operation start position to be activated at a predetermined time. An electromagnet, a spring stretched between the rear-blade operating member and the rear-blade drive member, and a suppression unit that prevents the rear-blade operating member from following the rear-blade drive member during setting. It has a first engagement portion and a second engagement portion When the first engaging portion is pressed by the leading blade driving member at the end of the setting, the second engaging portion is positioned within the operating path of the rear blade driving member, and An intermediary member for releasing the restraint, and operating from an initial position to actuate each of the drive members to a set position against each of the drive springs, and at the end of the set, for the rear blade in place of the restraining portion. A set member that suppresses the operation member and returns to the initial position by releasing the suppression at the initial stage of the shooting operation, and a detection unit that can detect an exposure operation of the front blade group or the front blade drive member, When the driving member for the rear blade is operated by the driving spring for the rear blade when the driving member for the front blade is at the exposure operation start position, the driving member for the front blade is forcibly activated via the intermediary member. Focal plane shutter, characterized in that so as to. 3. The intermediate member is urged by a spring so as to rotate in one direction, and is rotated against the urging force of the spring at the time of setting, so that the leading blade driving member starts an exposure operation. 3. The focal plane shutter according to claim 1, wherein the shutter is returned by an urging force of the spring when the shutter is released.