JP2002328409A - Focal-plane shutter for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focal-plane shutter for a direct type camera, where a driving member can be surely stopped at an exposure operation start position in the initial stage of photographing and the exposure operation start position is prevented from being fluctuated. SOLUTION: When a set member is restored to an initial position in the initial stage of photographing, the driving member 10 follows up to the exposure operation start position by the energizing force of a driving spring, and stops in a state where its mount part 10d abuts on the head part 12c of an iron core member 12. At such a time, the member 10 happens to start exposure operation earlier than specified timing by separating the member 12 attracted to the iron core 7 of an electromagnet. However, since a cushioning member 16 is provided, a shock at the abutting time is softened before. Since the member 16 is embedded in the recessed part of the mount part 10d and the mount part 10d directly comes into contact with the head part 12c at the time of stopping after abutting, the exposure operation start position is not fluctuated even when the member 16 is elastically changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focal plane shutter for a camera which can be used for both a camera using a film and a digital camera.

[0002]

2. Description of the Related Art Recent focal plane shutters have two shutter blades (a front blade (group) and a rear blade (group)), which are called a shutter base plate, an intermediate plate and an auxiliary base plate. They are separately arranged in two blade chambers composed of three plate members. Some focal plane shutters for digital cameras have only one shutter blade. In such a case, one of the above-mentioned two main plates may constitute one blade chamber. I have to. And in each case, each shutter blade is
For two arms, one end of which is pivotally attached to the shutter base plate,
By pivotally supporting one or more blades, a configuration using a parallelogram link mechanism is adopted.

A support plate is attached to the shutter base plate at a predetermined interval in one side area of the exposure opening, and a driving member and a support member are provided between the shutter base plate and the support plate. A rotating member such as a set member is arranged. Among them, the driving member causes the shutter blade to open and close the exposure opening by reciprocating one of the two arms described above, and when the holding force at the exposure operation start position is released by the electromagnet. The shutter blades are rapidly rotated by the urging force of a drive spring to cause the shutter blades to perform an exposure operation. Accordingly, in the case of a shutter having two shutter blades, two such driving members are provided. The set member is operated by a member on the camera body side, and rotates the drive member to the set position against the urging force of the drive spring.

[0004] By the way, as a structure for holding the driving member at the exposure operation start position, there are a structure called a locking type and a structure called a direct type. The present invention relates to a direct type focal plane shutter. As is well known, in the direct type configuration, an iron piece member is attached to a driving member, and immediately before the exposure operation, the electromagnet holds the driving member at the exposure operation start position by attracting the iron piece member. It is like that. Therefore, the number of components is small, which is advantageous for cost reduction and compactness. On the other hand, various special countermeasures are taken for manufacturing reasons.

Therefore, first, a well-known but essential configuration of the countermeasures will be described. As mentioned above,
At the time of setting, the set member rotates from the initial position to rotate the drive member to the set position, and the rotation of the set member is preferably performed by the attracted surface of the iron piece member provided on the drive member and the attraction surface of the electromagnet. It is extremely difficult to manufacture so as to stop at the moment when a great contact relationship is obtained. Further, when the set member rotates the two drive members to the set position, the attracted surfaces of the two iron pieces and the attracted surfaces of the respective electromagnets are brought into contact at the same time, and the set member is stopped at that moment. It is very difficult to produce Therefore, the spring is interposed between the drive member and the iron piece member, and after the appropriate contact relationship between the iron piece member and the electromagnet is reliably obtained, the set member is stopped at the position where the spring is tensioned. ing.

[0006] Since such a configuration is employed, another problem arises when power is saved by reducing the current supplied to the electromagnet. That is, the exposure operation start position of the drive member is the position at the moment when the iron piece member and the electromagnet are preferably in contact in the set operation. However, when the set member stops at the set position as described above, the drive member exceeds the exposure operation start position, tensions the spring interposed between the set member and the iron piece member, and overcharges the drive spring. Position. On the other hand,
The current is supplied to the electromagnet when the release button is pressed during photographing. Therefore, the set member does not return to the initial position and remains at the set position until the next photographing is performed.

Therefore, when the release button is pressed at the time of the next photographing, the electromagnet sucks and holds the iron piece member.
The set member returns to the initial position. At this time, the drive member is moved between the biasing force of the overcharged drive spring and the spring that has been interposed between the iron piece member and the tension member. Due to the urging force, it rotates to the exposure operation start position, comes into contact with the iron piece member and is stopped. The rotation of the drive member to the exposure operation start position is slight. However, the biasing force of the drive spring acting at this time is increased by the amount of overcharging. In addition, a biasing force of a spring interposed between the iron piece member and the iron piece member also acts. Further, the inertia of the driving member and the shutter blades also works. Therefore, the force applied to the iron piece member is much greater at the moment when the drive member stops at the exposure operation start position as described above than when the drive member is thereafter held at the exposure operation start position.

Therefore, if the current supply to the electromagnet is to be reduced in order to save power, there is no problem if the driving member is merely held at the exposure operation start position.
When the driving member stops at the exposure operation start position, the iron piece member is separated from the electromagnet by the impact at that time, and before the energization of the electromagnet is cut off by a signal from the control circuit,
The driving member may operate with the shutter blade. However, if the urging force of the drive spring is reduced, the exposure operation of the shutter blades is slowed down.
Suitable high-speed shooting cannot be performed. Therefore, in order to solve such problems, various countermeasures have been proposed. One of them is to interpose a cushioning member such as rubber between the driving member and the iron piece member, and to reduce the driving member. Japanese Patent Application Laid-Open No. 2620390 discloses a first example (hereinafter, referred to as a conventional example) that absorbs an impact at the time of contact with an iron piece member.

[0009]

However, in the above-mentioned conventional arrangement, since a buffer member having elasticity such as rubber is disposed between the contact portions of the driving member and the iron piece member, it is certain that the cushioning member is provided. The impact at the time of contact can be reduced, and the iron piece member can be prevented from separating from the electromagnet. However, in such a configuration, it is necessary to consider another problem. That is, a member made of an elastic material such as rubber may cause an elastic change due to an environmental change such as a temperature. In addition, the elasticity may change due to long-term use or severe use.

[0010] Therefore, if the elastic member such as rubber is simply disposed between the contact portions of the driving member and the iron piece member as in the above-described conventional example, the elasticity of the cushion member changes. In such a case, even if the change in the buffer function is allowed, the distance between the contact portion of the driving member and the iron piece member at the exposure operation start position will change. In this case, since the contact relationship between the iron piece member and the electromagnet does not change, the exposure operation start position of the driving member changes, and accordingly, the exposure operation start position of the shutter blade also changes. That
It will cause serious phenomena.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a driving member which contacts an iron piece member at an exposure operation start position before an exposure operation is started. Even if a cushioning member made of an elastic material such as rubber is arranged between the contact portion of the driving member and the iron piece member in order to reduce the impact force, the exposure of the driving member and the shutter blade due to the elastic change of the cushioning member. An object of the present invention is to provide a direct-type focal plane shutter for a camera in which an operation start position is not changed.

[0012]

In order to achieve the above object, a focal plane shutter for a camera according to the present invention comprises:
At least one driving member that is operated with the shutter blades from the exposure operation start position by an urging force of a driving spring during the exposure operation, and at least one driving member that is energized at an initial stage of photographing and is cut off by a signal from a control circuit. Two electromagnets, an iron piece member attached via a first elastic member so as to be capable of changing a relative position with respect to the driving member, and an iron piece member operating from an initial position to move the driving member to the electromagnet. Even after the contact, the first elastic member is compressed to operate to the set position, and when returning to the initial position after energizing the electromagnet, the driving member operates to the exposure operation start position in contact with the iron piece member. A setting member that is arranged between the driving member and the iron piece member, and is located between the contact portions of the driving member and the iron piece member before the setting member returns to the initial position. A second elastic member that is compressed and elastically deformed by the driving member until the driving member directly contacts the iron piece member and is buried in a recess formed in at least one of the contact portions after the contact; To have

In the focal plane shutter for a camera according to the present invention, the first elastic member and the second elastic member may be integrally formed of rubber.
It is very advantageous in terms of cost if they are made integrally with a spring.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to three illustrated embodiments. FIG. 1 is a plan view of the first embodiment showing an approximately left half when viewed from a subject side in a state where it is incorporated in a camera, and shows a state immediately after the end of an exposure operation. FIG. 2 is a plan view of the first embodiment viewed in the same manner as FIG. 1 and shows a set state, and FIG. 3 is a sectional view of a main part of FIG. FIG. 4 is a plan view of the first embodiment viewed in the same manner as FIG. 1 and shows a state immediately before the start of the exposure operation.
FIG. 5 is a sectional view of a main part of FIG. FIG. 6 is a cross-sectional view showing a main part of the second embodiment in the set state in the same manner as FIG. 3, and FIG. 7 is a main part of the second embodiment just before the start of the exposure operation, which is the same as FIG. FIG. 4 is a cross-sectional view shown as above. FIG. 8 is a perspective view showing the cushioning member,
FIG. 8A shows a cushioning member of the second embodiment, and FIG. 8B shows a modification thereof. FIG. 9 is a cross-sectional view of the third embodiment viewed in the same manner as in FIGS. 3 and 6.

[First Embodiment] First, the configuration of this embodiment is
The description will be made mainly with reference to FIGS. 1 and 3. In the description, the subject side is referred to as the front side, and the opposite side is referred to as the back side. In FIG. 1, a shutter base plate 1 is
An opening 1a in which a rectangle is horizontally elongated is formed at a substantially central portion thereof. However, since FIG. 1 shows only about the left half as viewed from the subject side, only a part of the opening 1a is shown. Have been. As shown in FIG. 3, the intermediate plate 2 and the auxiliary base plate 3 are provided on the back side of the shutter base plate 1 at a predetermined interval.
Are mounted in order, and a shutter base plate 1 and an intermediate plate 2
To form a blade chamber of the front blade, and a blade chamber of the rear blade between the intermediate plate 2 and the auxiliary base plate 3. An opening similar to the opening 1a is also formed in the intermediate plate 2 and the auxiliary base plate 3, and the three openings are usually overlapped to regulate the exposure opening. In the present embodiment, description will be made assuming that the shape of the opening 1a regulates the exposure opening.

In FIG. 1, two arc-shaped long holes 1b and 1c are formed on the left side of the opening 1a, and the lower end thereof has a substantially C-shaped plan view. A well-known cushioning member is attached. The shafts 1d and 1e erected on the shutter base plate 1 have the same shape, and can be seen from the shaft 1e shown in FIG. Also has a shaft. A shaft 1f is provided upright on the front side of the shutter base plate 1, and the support plate 4 and the printed wiring board 5 are attached to the ends of the two shafts 1d and 1e in an overlapping manner. (See FIG. 3). However, in FIG. 1, the illustration of the support plate 4 and the printed wiring board 5 is omitted. Further, on the rear side of the shutter base plate 1, a shaft 1 is provided.
g, 1h are erected.

The support plate 4 is made of a relatively thin metal plate. Although not shown, the support plate 4 is provided with many bent portions bent toward the shutter base plate 1 side.
Some of these bent portions are disclosed in Japanese Patent Laid-Open No. 9-133.
An electromagnet for the leading blade and an electromagnet for the trailing blade are attached according to the method described in Japanese Patent No. 944, FIG.
In FIG. 2, only the iron cores 6 and 7 of those electromagnets are shown by dashed lines for easy viewing of the drawing. The electromagnets for the front blade and the rear blade have exactly the same configuration, and as can be seen from the electromagnets for the rear blade shown in FIG. 3, the iron cores 6 and 7 are each formed in a U-shape. In this case, a bobbin around which a coil is wound is fitted to one of the magnetic pole portions.

Further, well-known ratchet members are rotatably mounted on the shafts 1d and 1e, respectively, in exactly the same manner. The mounting structure thereof is shown in a ratchet wheel shown in FIG. 8 will be described. A small-diameter portion is provided on the tip end side of the shaft 1e.
Is rotatable at its small diameter portion. Also,
The ratchet member 8 has ratchet teeth formed on an outer peripheral surface thereof, and is engaged with a flexible bent portion (not shown) provided on the support plate 4 to prevent rotation.
Further, a concave portion for receiving a part of a drive spring, which will be described later, is formed in an annular shape on the surface on the side of the shutter base plate 1, and one end of the drive spring is supported therein as is well known, although not shown. A spring hook portion is formed.

On the front side of the shutter base plate 1, the shaft 1
A driving member 9 for the front blade and a driving member 10 for the rear blade are rotatably attached to d and 1e. Most of these driving members 9 and 10 are made of synthetic resin.
Only the sleeves 9a and 10a fitted to d and 1e are made of metal. Each of the driving members 9 and 10 includes a pushed portion 9b, 10b, a driving pin 9c, 10c,
d and 10d. Then, the drive pins 9c, 1
0c is provided on the back side, the cross-sectional shape of the base is circular, the cross-sectional shape of the tip is oval, and the foremost portion is formed by a long hole formed in the auxiliary base plate 3. Has been inserted.

FIG. 1 shows a part of the mounting portions 9d and 10d broken away to show the inside easily. Iron pieces 11 and 12 are mounted on these mounting portions 9d and 10d. The iron piece members 11 and 12 are iron pieces 11a and 12a that are sucked and held by the iron cores 6 and 7, shaft parts 11b and 12b that can be slid with respect to the mounting parts 9d and 10d, and flange-shaped stoppers. The heads 11c, 12c are configured to be urged by the compression coil springs 13, 14 arranged inside the mounting portions 9d, 10d so that the iron pieces 11a, 12a protrude from the inside of the mounting portions 9d, 10d. ing.

Further, the mounting portions 9d and 10d are formed with annular concave portions on the surfaces of the iron piece members 11 and 12 facing the head portions 11c and 12c, and these concave portions have rubber (silicon resin). Ring-shaped cushioning members 15 and 16 made of an elastic material such as synthetic rubber (e.g., synthetic rubber). And as can be seen from the case of the one cushioning member 16 shown in FIG.
The cross section is elliptical, and the head 1 of the iron piece members 11 and 12
When 1c and 12c are apart from the mounting portions 9d and 10d, a part of them protrudes out of the concave portion.

As shown in FIG. 3, a drive spring 17 having a strong urging force is fitted on the sleeve 10a of the above-mentioned rear blade drive member 10, and one end thereof is connected to the ratchet as described above. It is hung on the member 8 and the other end is hung on a spring hook (not shown) provided on the rear blade drive member 10. The driving spring 17 biases the rear blade driving member 10 to rotate clockwise in FIG. Therefore, the urging force is applied to the ratchet member 8.
Is rotated in the counterclockwise direction, but the rotation in the counterclockwise direction is prevented by the above-mentioned bent portion (not shown) provided on the support plate 4.
On the other hand, a drive spring (not shown) is also fitted to the sleeve 9a of the drive member 9 for the leading blade, and
In the same manner as in the case of No. 7, it is hung between the leading blade driving member 9 and a ratchet member not shown. Therefore, the drive spring (not shown) urges the leading blade drive member 9 to rotate clockwise in FIG.

A set member 18 made of synthetic resin is rotatably mounted on the shaft 1f of the shutter base plate 1 described above. This set member 18 is, in FIG.
Although it is urged to rotate in the counterclockwise direction by the urging force of a return spring (not shown), the rotation is prevented by a stopper (not shown). Hereinafter, this position of the set member 18 will be referred to as an initial position. Further, the set member 18 is
a, 18b and a pushed portion 18c, and when rotated clockwise in FIG. 1, the pushing portion 18a pushes the pushed portion 9b of the leading blade driving member 9, and the pushing portion Reference numeral 18b presses the driven portion 10b of the rear blade drive member 10.

Next, the structure of the front blade and the rear blade disposed on the back side of the shutter base plate 1 will be described. First, the leading blade is disposed between the shutter base plate 1 and the intermediate plate 2,
It is composed of two arms 19 and 20 and a plurality of blades pivotally supported in the longitudinal direction of the arms. Since these configurations are well known, in order to make the drawing easy to see, the blades are formed. Of these, only the slit forming blade 21 pivotally supported at the tip of the arms 19 and 20 is shown. The arm 19 has a sleeve rotatably fitted to the shaft 1d, and an oval-shaped hole has
The leading end of the drive pin 9c of the leading blade drive member 9 is fitted. The other arm 20 has its sleeve rotatably fitted to the shaft 1g.

On the other hand, the rear blade is arranged between the intermediate plate 2 and the auxiliary base plate 3, and is composed of two arms 22, 23 and a plurality of blades pivotally supported in the longitudinal direction thereof. However, as in the case of the leading blade, only the slit forming blade 24 pivotally supported at the forefront of the arms 22 and 23 is illustrated. The arm 22 has a sleeve rotatably fitted to the shaft 1e, and a hole formed in an oval shape has a driving pin 10c of the driving member 10 for the rear blade.
Are fitted. The other arm 23 has its sleeve rotatably fitted to the shaft 1h.

Next, the operation of this embodiment will be described. FIG.
Indicates a state immediately after the end of the exposure operation. Therefore, the leading blade drive member 9 is urged to rotate clockwise by a drive spring (not shown), but a drive pin 9c is attached to the lower end of the long hole 1b as shown in FIG. This stopped state is maintained by contacting the buffer member that is not in operation. At this time, since the urging force of the compression coil spring 13 is larger than the urging force of the buffer member 15, the iron piece member 11 completely buries the buffer member 15 in the recess of the mounting portion 9d and mounts the head 11c. It is in contact with the portion 9d.
Then, the plurality of blades of the leading blade are overlapped, and the opening 1a is formed.
Is stored in the lower position.

On the other hand, the rear blade drive member 10 is urged to rotate clockwise by a drive spring 17, and a drive pin 10c is attached to the lower end of the elongated hole 1c as shown in a known diagram. This stopped state is maintained by contacting the buffer member that is not in operation. At this time, since the urging force of the compression coil spring 14 is greater than the urging force of the cushioning member 16, the iron piece member 12 attaches the cushioning member 16 to the mounting portion 10d.
Completely buried in the recess, and the head 12c is attached to the mounting portion 10d.
Contact. The rear blades are deployed to cover the opening 1a.

The setting operation of the present embodiment is performed by rotating a setting member 18 clockwise by a member (not shown) on the camera body side. That is, when the member on the camera body side pushes the pushed portion 18c of the set member 18 and rotates clockwise against the urging force of the not-shown return spring, first, the pushing portion 18a of the set member 18 is pressed. Pushes the pushed portion 9b of the leading blade drive member 9 and rotates it counterclockwise against the urging force of a drive spring (not shown). Further, by this rotation, the drive pin 9c of the leading blade drive member 9 rotates the arm 19 in the counterclockwise direction, and moves the leading blade upward while deploying a plurality of blades.

Thereafter, the slit forming blade 21 of the leading blade 21
When the overlapping amount of the rear blade and the slit forming blade 24 reaches a predetermined amount, the pushing portion 18b of the set member 18 pushes the pushed portion 10b, and the rear blade driving member 10 is rotated in the counterclockwise direction. To go. Therefore, the drive pin 10c is
2 is rotated counterclockwise, and the rear blades are moved upward while overlapping a plurality of blades. Then, thereafter, the iron piece members 11 and 12 attached to the respective drive members 9 and 10
Contact the iron cores 6 and 7 of the respective electromagnets.
8, the drive member 9, even after the iron piece members 11, 12 stop,
10 is slightly rotated to stop, and the set operation ends.

The end state of the set operation performed in this manner, that is, the set state is shown in FIG. 2 and FIG. 3, and at this time, the plurality of rear blades are in a superimposed state and the opening portion is formed. It is stored at a position above 1a, and the plurality of blades of the leading blade are in a deployed state and cover the opening 1a. Further, as described above, since the driving members 9 and 10 are slightly rotated even after the iron piece members 11 and 12 are stopped, the compression coil springs 13 and 14 are compressed and the iron piece members 11 and 12 The heads 11c and 12c are attached to the mounting portions 9d and 10
away from d. Therefore, the cushioning members 15 and 16
The force to be compressed is released, and part of the force is
d, protrude outside from the recess formed in 10d. FIG. 3 shows the state at that time so that it can be easily understood. Then, even after such a state is obtained, the set member 18 maintains this state until the next photographing is performed.

At the time of the next photographing, when the release button of the camera is pressed, first, the coil of each electromagnet is energized,
The iron pieces 11 and 12 are attracted and held by the iron cores 6 and 7. Thereafter, when a member on the camera body (not shown) releases the pressing force of the set member 18 against the pushed portion 18c, the set member 18 is moved in a counterclockwise direction by the urging force of a return spring (not shown). It rotates and returns to the initial position. When the setting member 18 returns to the initial position in this manner, the iron members 11 and 12 do not operate, but the driving members 9 and 10 are driven by the heads 11 c and 12 c of the iron members 11 and 12.
It is operated by the biasing force of each overcharged drive spring by the distance between the mounting springs 9d and 10d.

Therefore, as in the present embodiment, the cushioning members 15,
16 is not provided, the mounting portions 9d, 10d
The iron pieces 11 and 12 are separated from the iron cores 6 and 7 by an impact when the abutment comes into contact with the heads 11c and 12c.
Will be operated up to the state of FIG. Therefore, in order to prevent such a problem from occurring, conventionally, the current supplied to the electromagnet is increased so as to withstand the impact, and the suction holding force on the iron piece members 11 and 12 is increased. Mounting part 9d, 1 in set state
The distance between 0d and the heads 11c and 12c was made as small as possible. Therefore, there has been a problem that power consumption is increased and cost is increased in order to increase processing accuracy.

However, in the case of this embodiment, at this time, a part of the cushioning members 15 and 16 is attached to the mounting portions 9d and 10d.
d initially project from head 1
1c, 12c, and is compressed and deformed, and most of the cushioning members 15, 16 are buried in the recesses of the mounting portions 9d, 10d, or after being completely buried, the mounting portions 9d, 1
0d contacts the heads 11c and 12c. Therefore, the impact force at that time is significantly reduced, and the iron piece members 11 and 1 can be provided without increasing the supply current or increasing the manufacturing accuracy.
2 can be reliably sucked and held, and the driving members 9 and 10 can be stopped.

In this embodiment, the cushioning members 15 and
16 is made of rubber, but may be made of a spring material such as a coil spring or a leaf spring. In the present embodiment, the cushioning members 15 and 16 do not contact the heads 11c and 12c of the iron pieces 11 and 12 in the set state. However, the cushioning members 15 and 16 may be in contact. . Furthermore, in the present embodiment, the recesses in which the buffer members 15 and 16 are buried are formed in the mounting portions 9d and 10d of the driving members 9 and 10, however, if the design specifications permit, the iron piece member 11 may be used. , 12 may be formed on the heads 11c, 12c, or may be formed on both the mounting portions 9d, 10d and the heads 11c, 12c.

FIGS. 4 and 5 show the state in which the driving members 9 and 10 are stopped. The position in this state is the exposure operation start position for the driving members 9 and 10 and the front blade and the rear blade, and
5 and 16 are completely buried in the mounting portions 9d and 10d. Therefore, unlike the conventional example disclosed in the above-mentioned Japanese Patent No. 2620390, the mounting portions 9d and 10d and the heads 11c and 12c are always in contact with each other at the exposure operation start position, so that the temperature change and the aging. Even if the functions of the buffer members 15 and 16 are slightly changed due to the change, the exposure operation start positions of the drive members 9 and 10 are never changed, and the desired suitable state is obtained. Operation is assuredly obtained.

After the state shown in FIG. 4 is surely obtained, first, the current supply to the electromagnet for the leading blade is cut off.
After a predetermined time, the power supply to the rear-wing electromagnet is cut off.
Therefore, the driving member 9 for the front blade and the driving member 10 for the rear blade
Are rapidly rotated clockwise one after another by the urging force of each drive spring, and each arm 19, 22 is rotated clockwise by each drive pin 9c, 10c, so that the slit forming blade 21 of the front blade and the rear blade 21 are rotated. Blade slit forming blade 2
Exposure of the image forming surface is performed by the slit formed by step 4 and step 4.

The driving member 9 for the front blade, which has started the exposure operation first, is driven by the driving pin 9c at the end of the operation.
Is brought into contact with the buffer member attached to the lower end of the elongated hole 1b and stopped, and subsequently, the rear blade drive member 10
At the end of the operation, the drive pin 10c
It is stopped by contacting the buffer member attached to the lower end of the long hole 1c. Therefore, in the stopped state, the plurality of blades of the leading blade are superimposed and stored at a position below the opening 1a, and the plurality of blades of the trailing blade are unfolded to cover the opening 1a. The state immediately after the end of the exposure operation is the state shown in FIG.

[Second Embodiment] The structure of this embodiment is different from the first embodiment in that the compression coil springs 13 and 14 and the cushioning member 1 of the first embodiment are used.
5 and 16 are integrally made of the same elastic material such as rubber (including synthetic rubber such as silicone resin), unlike the first embodiment, and other configurations are substantially the same as those of the first embodiment. Is the same as For this reason, in FIGS. 6 and 7, members and portions other than the cushioning member 26 are all given the same reference numerals as in the first embodiment. Further, the cushioning member 26 of the present embodiment
Is shown as an enlarged perspective view in FIG.
As you can see, it has a shape like Tesuzu as a whole. In the center, the shaft 1 of the iron piece 12
A large-diameter portion 26b serving as the compression coil spring 14 in the first embodiment and a role serving as the cushioning member 16 are formed on both axial sides of the hole 26a. Is formed.

FIGS. 6 and 7 show the same states as those in FIGS. 3 and 5 of the first embodiment, but FIG. 6 and FIG. 6, the large diameter portion 26b of the cushioning member 26 is compressed and deformed, and the head 12c of the iron piece member 12 is separated from the mounting portion 10d of the rear blade drive member 10. Then, the small-diameter portion 2 of the buffer member 26 is removed from the recess formed in the mounting portion 10d.
6c protrudes a part thereof, but at this time, the small diameter portion 26c may be brought into contact with the head 12c. Further, as shown in FIG. 7, at the exposure operation start position of the rear blade drive member 10,
The large-diameter portion 26b is released from the compression deformation, and the small-diameter portion 26c is compressed and deformed and buried in the concave portion formed in the mounting portion 10d.
c.

When constructed as in this embodiment, the cushioning member 2
6 is flexible, so that it is deformed and
By allowing c to pass through the hole of the mounting portion 10d, it is possible to easily mount the compression coil spring 14 and the cushioning member 16 in the first embodiment as one component. This is extremely advantageous in terms of cost. FIG. 8B shows a modified example of the cushioning member 26 in the present embodiment. When the large-diameter portion 26b is partially cut away as described above, the large-diameter portion 26b is formed.
Can be deformed so as to penetrate through the hole of the mounting portion 10d. In addition, other things
What has been described in the description of the embodiment also applies to this embodiment.

[Third Embodiment] The structure of the present embodiment is different from that of the first embodiment in that the compression coil springs 13 and 14 and the buffer member 1 are used.
5 and 16 are the same as the second embodiment in that they are manufactured integrally from one material. However, in the case of the second embodiment, the material is made of an elastic material such as rubber, whereas in the case of this embodiment, a coil spring is manufactured using a spring material. Since other structures are substantially the same as those of the first embodiment, in FIG. 9, all members and parts except for the buffer member 36 made of a coil spring in this manner are provided with the first embodiment. The same reference numerals as in the example are used.

As can be inferred from FIG. 9, the cushioning member 36 of the present embodiment has a barrel-like overall shape before mounting. The left half in FIG. 9 functions as the compression coil spring 14 in the first embodiment, and the right half functions as the buffer member 16. Further, in the state of FIG. 9, the buffer member 36 is in contact with the head 12 c of the iron piece member 12, but may not be in contact. However, even in this case, when a part of the cushioning member 36 protrudes from the concave portion of the mounting portion 10d and the rear blade driving member 10 is at the exposure operation start position, it is compressed and deformed and buried in the concave portion. It goes without saying that it is made to be done.

When the cushioning member 36 is mounted, one end of the coil spring is passed through a hole in the mounting portion 10d, and the coil spring is advanced while rotating and mounted in the state shown in the figure. Therefore, since the cushioning member 36 of this embodiment has a barrel shape as described above, it can be mounted from the right side or the left side in FIG. There is an advantage that there is no need to insert. However, as long as the function of solving the problem of the present invention can be obtained, another shape may be used, or a shape that can limit the insertion end may be used. Further, the mounting method of the cushioning member 36 is not the same as that of the present embodiment, but is inserted into the hole of the mounting portion 10d from the axial direction. A slot may be formed and inserted into the hole from the radial direction.

Each of the above embodiments has been described in connection with a shutter provided with two shutter blades, that is, a front blade and a rear blade, and also provided with a driving member for the front blade and a driving member for the rear blade. Such a shutter can be used for a camera using a film, but can also be used for a digital camera. Also, some shutters used in digital cameras have only one shutter blade, and even in this case, some shutters have only one blade. Therefore,
In such a case, it goes without saying that only one drive member is provided, but the present invention can be applied to such a shutter.

[0045]

As described above, according to the present invention, in order to reduce the impact force when the driving member contacts the iron piece member at the exposure operation start position before the exposure operation starts, the driving member and the iron piece member Even if a buffering means is interposed in between, the driving member can be brought into direct contact with the iron piece in the end, so that the exposure operation start position of the driving member or the shutter blade is changed by the elastic change of the buffering means. There is a feature that does not change.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment viewed from a subject side in a state in which the exposure apparatus is incorporated in a camera, and shows a state immediately after an exposure operation is completed.

FIG. 2 is a plan view of the first embodiment viewed in the same manner as in FIG. 1, showing a set state.

FIG. 3 is a sectional view of a main part of FIG. 2;

FIG. 4 is a plan view of the first embodiment viewed in the same manner as in FIG. 1, and shows a state immediately before the start of an exposure operation.

FIG. 5 is a sectional view of a main part of FIG.

FIG. 6 is a sectional view showing a main part of the second embodiment in a set state in the same manner as in FIG. 3;

FIG. 7 is a sectional view showing a main part of the second embodiment immediately before the start of the exposure operation in the same manner as in FIG. 5;

FIG. 8A is a perspective view showing a cushioning member of a second embodiment, and FIG. 8B is a perspective view showing a modification thereof.

FIG. 9 is a sectional view showing a main part of the third embodiment in a set state in the same manner as in FIGS. 3 and 6.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shutter base plate 1a Opening 1b, 1c Slot 1d, 1e, 1f, 1g, 1h Shaft 2 Intermediate plate 3 Auxiliary base plate 4 Support plate 5 Printed wiring board 6, 7 Iron core 8 Ratchet member 9 Tip blade drive member 9a, 10a Sleeve 9b, 10b, 18c Pushed portion 9c, 10c Drive pin 9d, 10d Attachment portion 10 Rear blade drive member 11, 12 Iron piece member 11a, 12a Iron piece portion 11b, 12b Shaft portion 11c, 12c Head portion 13, 14 Compression coil spring 15, 16, 26, 36 Buffer member 17 Drive spring 18 Set member 18a, 18b Pushing portion 19, 20, 22, 23 Arm 21, 24 Slit forming blade 26a Hole 26b Large diameter portion 26c Small diameter portion

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H081 AA28 AA31 BB01 BB11 BB22 BB26 BB39 CC33 5C022 AA00 AB41 AC52 AC74 CA00

Claims (3)

[Claims] At least one driving member that is operated with a shutter blade from an exposure operation start position by an urging force of a driving spring during an exposure operation, and is energized at an initial stage of photographing and is energized by a signal from a control circuit. At least one electromagnet to be cut off, an iron piece member attached via a first elastic member so as to be capable of changing a relative position with respect to the driving member, and an iron piece operated from an initial position to move the driving member to the iron piece. An exposure operation start position in which the driving member is in contact with the iron piece member when the first elastic member is compressed to operate to the set position even after the member comes into contact with the electromagnet and returns to the initial position after the electromagnet is energized. And a set member that is capable of operating up to a maximum position, and a set member that is disposed between abutting portions of the drive member and the iron piece member so that the set member returns to an initial position. When returning, the driving member is compressed and elastically deformed by the driving member until the driving member directly contacts the iron piece member, and after the contact, the driving member is buried in a recess formed in at least one of the contact portions. A focal plane shutter for a camera, comprising: an elastic member. 2. The focal plane shutter for a camera according to claim 1, wherein the first elastic member and the second elastic member are integrally formed of rubber. 3. The focal plane shutter for a camera according to claim 1, wherein the first elastic member and the second elastic member are integrally formed by a spring.