JPH09304809A - Focal-plane shutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a direct type focal-plane shutter capable of surely keeping the traveling timing of a driving member and making an attracting force small as well. SOLUTION: When a setting member 14 is returned to an initial position, prior to an exposure operation, after releasing is attained, the driving member 5 is slightly tuned by the force of a press spring 11 and a driving spring 13, the instant a pushing part 14c is separated from the part to be pushed 5d of the following sector driving member 5, so that an attaching part 5c is abutted on an end part 9b1 provided on the iron piece shaft 9b of an iron piece member 9, to try to separate the iron piece member 9 from an electromagnet 17 by the impact force of the abutting. However, the pressing part 19b of a pressing member 19 presses the end part 9b1 of the iron piece shaft 9b, so that the iron piece member 9 can keep an attracting state by the electromagnet 17, without being separated. After that, the pressing part 19b is retreated out of the locus of the actuation of the iron piece member 9, linked with the returning operation of the setting member.

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 in which a group of front blades and a group of rear blades are sequentially moved in the same direction during photographing, and a film is exposed by slits formed by the groups. About.

[0002]

2. Description of the Related Art In a recent focal plane shutter, a group of front blades and a group of rear blades are operated by respective driving members, and the start of the operation of the driving members is performed through electromagnets prepared respectively. It is controlled. The use of the electromagnet for the driving member is roughly classified into two types.
No. 139, etc., which is generally referred to as a locking type.
It is known in, for example, Japanese Patent Application Laid-Open No. 2-22636, and is generally called a direct type.

[0003] Among them, the locking type has been practiced for a long time, and the driving member is locked by a locking lever at the set position. Therefore, even if the driving member is returned to the initial position immediately after the driving member is set at the setting position, the driving member can be securely held at the setting position until the exposure operation. There is an advantage that it is not necessary to expect a time for returning to the normal state, and the risk of missing a photo opportunity can be reduced. Further, when electricity is supplied to the electromagnet at the time of photographing, there is no need to magnetically hold the drive member against the force of the strong drive spring, so-called a so-called provided for releasing the lock of the drive member by the locking lever. Since it is only necessary to attract the iron piece lever, there is an advantage that the holding force by the electromagnet does not need to be increased.

However, on the other hand, in addition to the above-mentioned locking lever and iron lever, the iron lever is moved to a position where the electromagnet can be attracted by interlocking with the setting operation of the set member, and the iron lever is moved before the exposure operation. After being attracted to the iron piece lever, a so-called hold lever or the like that retreats from the operating range of the iron piece lever is required.Moreover, since each of these levers is spring-loaded, the number of parts is large, In addition to the complicated structure, the adjustment of the operation of each part during the manufacturing process is troublesome, which is very disadvantageous in reducing the size and cost of the shutter.

On the other hand, in the direct type, an iron piece attached to a driving member is attracted by an electromagnet. Therefore, the setting member cannot return to the initial position immediately after the driving member is set to the setting position, and the exposure of the blade group is performed after the driving member is magnetically held by the electromagnet prior to the exposure operation. It will be returned to the initial position prior to running. However, although the time for the return operation is required after the release in this way, such time can be made parallel to the time required for the mirror up and the time required for the automatic focus adjustment, etc. Almost no problem. Because of this, the direct type shutter does not require the above-mentioned various levers unlike the locking type, and is extremely advantageous in terms of space and cost. Recently, this type of shutter has increased. There is. The present invention relates to such a direct type focal plane shutter.

By the way, in such a direct type shutter, the driving member is magnetically attracted and held by the electromagnet against the strong force of the driving spring, so that the electromagnet is energized prior to the exposure operation. When this is done, the attracted surface of the iron piece member attached to the drive member is
It is required to be in a proper contact state (close contact state) with the attracting surface of the electromagnet. Therefore, in the actual implementation, even if there are some errors in parts processing and errors in assembly processing, when the drive member is set by the set member, it is not affected by such errors, It is devised so that the above-mentioned appropriate contact state can be obtained.

One example is described in Japanese Patent Application Laid-Open No. 3-231723. According to this example, the spring (absorption spring) is interposed between the driving member (driving lever) and the iron piece member (armature). When the set member (charge lever) operates the drive member to the set position, the spring is compressed after the attracted surface of the iron piece member properly contacts the attracted surface of the electromagnet (yoke). The compression amount absorbs the difference between individual shutters and the difference between the leading blade side and the trailing blade side so that the set operation can be performed without any trouble.

[0008]

As described above, the direct type shutter is extremely advantageous in space and cost as compared with the locking type shutter, but is resistant to the strong force of the drive spring. Since it is necessary to magnetically hold the driving member, there remains a problem in terms of power consumption. Therefore, the advent of an improvement measure that can securely hold the drive member by suction and that consumes as little power as possible is desired. However,
When considering the improvement measures,
If it is set to a minimum value that exceeds the urging force of the drive spring, that does not mean that there is no problem.

That is, in the above-mentioned Japanese Patent Laid-Open No. 3-231723, when the setting member is returned to the initial position prior to the exposure operation, the setting member releases the pressing of the driving member in the returning process. At this time, the drive member is slightly rotated by the combined force of the spring interposed between the iron piece member and the drive member and the drive spring, abuts on the iron piece member and separates from the electromagnet with respect to the iron piece member. It will give such a shock. Therefore, the attraction force of the electromagnet with respect to the iron piece member must be sufficient to withstand the impact force generated by the above contact.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a direct type focal-plane shutter.
When the driving member slightly moves to the exposure operation start position by releasing the pressing force of the setting member when the setting member returns to the initial position prior to the exposure traveling, the force of contacting the iron piece member by the operation is generated. To provide a focal-plane shutter for a camera, in which the lens is kept away from the electromagnet.

[0011]

To achieve the above object, a focal plane shutter for a camera according to the present invention has a pushed portion and is biased by a drive spring to expose and travel to a blade group. A driving member for performing the operation, an iron piece member that has an attracted surface that can be attracted to the attracting surface of the electromagnet, and is attached to the driving member so that the relative positional relationship can be changed; When a set is made, the pushing portion pushes the pushed portion to actuate the driving member against the driving spring to actuate the driving member. A set member that returns to the initial position prior to exposure traveling, and in the set state, the iron piece member is pressed so that the attracted surface contacts the attracted surface, and the set member returns to the initial position. In case of Dynamic portion is so and a pressing member so as to retract the actuation trajectory outside of the iron piece member after leaving from the object pushing portion. Further, in the focal plane shutter for a camera according to the present invention, preferably, a pressing spring that is tensioned between the drive member and the iron piece member by pressing the attracted surface against the attracted surface in a set state. To intervene. Further, in the focal plane shutter for a camera according to the present invention, preferably, the pushed portion is
It is provided on a swing member attached to the drive member, and the drive spring biases the drive member via the swing member. Further, in the focal plane shutter for a camera according to the present invention, preferably, the pressing member is operated in conjunction with the operation of the setting member.

Further, in the focal plane shutter for a camera according to the present invention, preferably, the pressing member has an elastic portion, and the elasticity acts on the pressing of the iron piece member. Further, in the focal plane shutter for a camera according to the present invention, preferably, the shape of the surface of the pressing member that presses the iron piece member is a convex spherical surface or an arc surface with respect to the iron piece member. . Further, in the focal plane shutter for a camera according to the present invention, preferably, the shape of the surface on which the iron piece member is pressed by the pressing member is a convex spherical surface or an arc surface with respect to the pressing member. .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the examples shown in FIGS. FIG. 1 is a plan view of the present embodiment and shows a state where the exposure traveling by the front blade group and the rear blade group is completed. FIG. 2 is a plan view for explaining the support structure of each blade group in this embodiment. 3 to 1
Reference numerals 0 are plan views of this embodiment, respectively, for explaining the operating state from the state of FIG. Note that FIG.
12A and 12B are drawings for explaining a modification of the iron piece member shown in the present embodiment, and FIGS.
(B) is an explanatory view showing a part of a known shutter configuration to which the present invention can be applied.

First, the configuration of this embodiment will be described mainly with reference to FIGS. 1 and 2. Incidentally, FIG. 1 shows a part of the configuration in a cross section similarly to the other FIGS. 4 to 10, and FIG.
1 shows a state in which the respective parts attached to the front surface side (the lens side of the camera) of the shutter base plate 1 in FIG. 1 are removed. The shutter base plate 1 has two arc-shaped holes 1b and 1c and a hole 1d in addition to the opening 1a for exposure. Well-known buffer members 2 and 3 made of an elastic material such as butyl rubber are fitted into the lower ends of the arc-shaped holes 1b and 1c.

On the surface side of the shutter base plate 1, the shaft 1
e, 1f, 1g, 1h, 1i, 1j, 1k, 1m, 1
n and 1p are provided upright, and a front blade driving member 4 and a rear blade driving member 5 made of synthetic resin are rotatably attached to the shafts 1e and 1f, respectively. Then, the cylindrical portions 4a, 5 which are rotatably fitted to the shafts 1e, 1f are respectively attached to the respective driving members 4, 5.
a, drive pins 4b and 5b, mounting portions 4c and 5c, and pushed portions 4d and 5d are integrally formed. this house,
The drive pins 4b and 5b penetrate through the holes 1b and 1c and are fitted into holes 6a and 7a formed in the main arms 6 and 7 of the leading blade group and the trailing blade group on the rear side of the shutter base plate 1 as is well known. are doing.

Iron piece members 8 and 9 are attached to the attachment portions 4c and 5c. The iron piece members 8 and 9 are
It is composed of iron pieces 8a, 9a to be attracted to an electromagnet, which will be described later, and iron piece shafts 8b, 9b, and the iron piece shafts 8b, 9b are loosely fitted in the holes formed in the mounting portions 4c, 5c. The iron pieces 8a and 9a have a shape elongated in the vertical direction of the drawing, and are integrated with one end of the iron piece shafts 8b and 9b at a substantially intermediate position. The other end 8 of the iron piece shaft 8b, 9b
The b ₁ and 9 b ₁ have a brim shape so that the iron piece members 8 and 9 do not fall off from the mounting portions 4 c and 5 c.
The iron piece members 8 and 9 are urged upward in FIG. 1 by the pressing springs 10 and 11 built in the mounting portions 4c and 5c. Further, the edges of the pushed portions 4d and 5d are formed in a cam shape.

As is well known, drive springs 12 and 13 are loosely wound around the cylindrical portions 4a and 5a of the drive members 4 and 5, respectively, and one end thereof is attached to the shafts 1k and 1m and the other end thereof is attached to a mounting portion. Four
The drive members 4 and 5 are urged so as to rotate clockwise by being hung on c and 5c. A synthetic resin set member 14 is rotatably attached to the shaft 1g. The set member 14 includes a cylindrical portion 14a that is rotatably fitted to the shaft 1g, two pushing portions 14b and 14c, a front surface side protrusion 14d, a rear side protrusion 14e, and a pin 1.
4f is provided by integral molding.

Of these, the pushing portion 14b can come into contact with the pushed portion 4d of the leading blade driving member 4, and the pushing portion 14c can come into contact with the pushed portion 5d of the trailing blade driving member 5. Each edge is formed in a cam shape. The protrusion 14d is operated by a member on the camera body side. Further, the protrusion 14e is fitted into the hole 1d of the shutter base plate 1, and the rotation of the setting member 14 is restricted by the upper and lower ends of the hole 1d in the drawing. The setting member 14 is urged counterclockwise by the spring 15 hung on the shaft 1j and the protrusion 14d, but in FIG. 1, its counterclockwise rotation is restricted by the lower end of the hole 1d. ing.

Although not shown because it is well known, a mounting plate (also referred to as an upper plate) is fixed to the shutter base plate 1 so as to be substantially parallel to the base plate. Two electromagnets 16 and 17 are attached to this attachment plate by a well-known appropriate method, as indicated by a chain line. The electromagnets 16 and 17 are substantially U-shaped and have two magnetic pole portions (the shutter base plate 1 in FIG. 1).
The two magnetic pole portions are attached so as to be vertically arranged with respect to the iron core members 16a, 17
a, a coil bobbin 16b fitted to one magnetic pole portion,
17b, and the tip end faces (end faces on the lower right side in the figure) of the respective magnetic pole portions serve as attraction faces for attracting the respective iron piece members 8 and 9.

Pressing members 18 and 19 are rotatably attached to the shafts 1h and 1i of the shutter base plate 1, respectively.
The pressing members 18 and 19 and the shafts 1n and 1p are urged in the counterclockwise direction by the respective springs 20 and 21 hung on the shafts 1n and 1p, and the rotation thereof is restricted by the shafts 1n and 1p. Bending portions 18a and 19a having elasticity (spring property) are formed on the pressing members 18 and 19, respectively, and pressing portions 18b and 19b are provided at respective tips. Then, the pressing member 18 is formed with two end surfaces 18c and 18d which are in sliding contact with the pin 14f of the setting member 14, and the pressing member 19 is formed with an elongated hole 19c. A transmission member 22 is rotatably attached to the shaft 1j of the shutter base plate 1, and one arm has a pin 22 fitted into the long hole 19c.
a is erected, and on the other arm, two end faces 22b and 22c that are in sliding contact with the pin 14f of the setting member 14 are formed.

Next, the operation of this embodiment will be described. FIG. 1 and FIG. 2 show a completed state of exposure traveling by the front blade group and the rear blade group. Therefore, in this state, the four blades forming the front blade group are superposed and stored in the lower position of the opening 1a, and the four blades forming the rear blade group are expanded to cover the opening 1a. ing. When the photographing is performed and the exposure traveling is completed, the setting operation of the shutter is performed in association with the film winding. And
For the setting operation, the member on the camera body side has the protrusion 14d.
By pushing and rotating the setting member 14 clockwise against the force of the spring 15.

When the set member 14 rotates in the clockwise direction, the pushing portion 14b first pushes the pushed portion 4d to rotate the leading blade driving member 4 counterclockwise. Then, after the slit forming blades of the front blade group overlap with the slit forming blades of the rear blade group by a predetermined amount, the pushing portion 14c pushes the pushed portion 5d to rotate the rear blade driving member 5 counterclockwise, After that, both drive members 4 and 5 are simultaneously rotated to expand the front blade group and superimpose the rear blade group. After that, the pin 14f of the setting member 14 comes into contact with the end surface 18c of the pressing member 18. Since the shape of the end face 18c is formed so as to be oblique with respect to the moving direction of the pin 14f at the time of this contact, after this contact, the pin 14f slides on the end face 18c and the pressing member 18 is spring-loaded. It will rotate clockwise against 20. Its starting position is shown in FIG. It should be noted that FIG. 3 does not show the mounting structure of the iron piece members 8 and 9 without a cross section.

After that, when the setting member 14 further rotates, the pin 14f comes into contact with the convex surface 22b of the transmission member 22 as well. The state at that time is shown in FIG. As can be seen from FIG. 4, the shape of the vicinity of the leading blade driving member 4 in which the pushed portion 4d is formed is such that a part thereof has two steps in the thickness direction. 4d is formed in a step on the shutter base plate 1 side. When the setting member 14 further rotates from such a state, the transmission member 22 moves the end surface 2
2b is pressed by the pin 14f and rotated in the counterclockwise direction, and the pressing member 19 is rotated in the clockwise direction against the spring 21 due to the connection relationship between the pin 22a and the elongated hole 19c. Therefore, after that, the two pressing members 18 and 19 simultaneously rotate in the clockwise direction.

Further, the setting member 14 rotates, the attracted surface of the iron piece member 8 attached to the leading blade driving member 4 contacts the attracting surface of the electromagnet 16, and the iron piece still attached to the trailing blade driving member 5. A state in which the attracted surface of the member 9 is not in contact with the attracted surface of the electromagnet 17 is shown in FIG. Then, in this state, the pressing portion 1 of the pressing member 18 has already been
8b is press end 8b ₁ of the iron piece shaft 8b, while the pin 14f is the end of the sliding contact with the end face 18c, is about to enter the sliding contact relation between the end surface 18d. If the timings of the two do not match, the pressing portion 18b is not attached to the iron piece shaft 8
A situation in which it cannot contact b occurs or the rotation of the set member 14 is hindered. Therefore, in the embodiment, the bent portion 18a has elasticity so that the timing deviation can be absorbed. Therefore, in the state shown in FIG. 5, the bent portion 18a is slightly bent. However, if there is no concern about the timing deviation, it is not necessary to impart elasticity in this way, and even in the case of imparting elasticity, it is conceivable to impart elasticity on the sliding contact side with the pin 14f. Further, in the embodiment, FIG.
In this state, the pressing direction of the pressing member 18 is the electromagnet 1
6 is set so as to be substantially orthogonal to the suction surface.

From the state shown in FIG. 5, the setting member 14 is slightly
The state of being rotated in the clockwise direction is shown in FIG. this
In this state, the attracted surface of the iron piece member 9 is also attached to the electromagnet 17.
It is in contact with the adsorption surface. Then, the pressing portion 1 of the pressing member 19
9b is an end 9b of the iron piece shaft 9b. ₁While holding down,
14f ends sliding contact with the end surface 22b, and ends with the end surface 22c.
Is about to enter the sliding relationship. Thailand of both at this time
The bent portion 19a has elasticity to absorb the misalignment.
It has a very slight bend in this state.
Is the same as above, and
The statements made above also apply in this case. Also, this
In this state, the pressing direction of the pressing member 19 is the electromagnet 1
Set so that it will be in a direction substantially orthogonal to the suction surface of 7.
It is also the same. Then, in the state of FIG.
In addition, the front blade group is already in the expanded state and the opening 1
a, and the rear blade group is superposed on the opening 1a.
It is stored in one direction.

By the way, the pushing portion 14 of the setting member 14
b, 14c and the driven parts 4d, 5d of the drive members 4, 5
The relationship between the state of FIG. 5 and the state of FIG.
The drive member 4 is prevented from rotating and is shown in FIG.
As described above, the attracted surface of the iron piece member 9 is the attracted surface of the electromagnet 17.
Stop the trailing blade drive member 5
Is ideal. But that kind of thing
Above all, it is not an exaggeration to say that it is impossible. Therefore, in FIG.
From the state, further rotate the setting member 14 to the position shown in FIG.
So that each drive member is rotated slightly counterclockwise.
However, the contact with each electromagnet should be ensured. So
In the meantime, the pin 14f keeps the end face 18 of the pressing member 18
d with respect to the end surface 22c of the transmission member 22,
As a rule, do not move the pressing members 18 and 19
You. Therefore, in the state of FIG. 7, the pressing spring 10,
11 is compressed and tensioned, and the end 8 of each iron piece shaft 8b, 9b
b₁, 9b ₁Are separated from the mounting portions 4c and 5c.
In this way, the shutter setting operation is completed,
The member 14 remains pressed by the member on the camera side,
It remains in the position of FIG.

In such a state of FIG. 7, when the shutter button of the camera is pressed, the electromagnets 16 and 17 are firstly pressed.
To the iron core members 16a and 17a.
It is magnetically attracted to and held by. After that, when the pressing of the protrusion 14d by the member on the camera body side is released, the set member 14 immediately follows by the force of the spring 15 and rotates counterclockwise. At this time, the pushing portion 14 of the setting member 14
Although b and 14c move away from the pushed parts 4d and 5d, first, the pushing part 14c moves away from the pushed part 5d. The state at the moment of attempting to leave is shown in FIG. Further, FIG. 9 shows the moment when the pushing portion 14c is separated from the pushed portion 5d, and the moment when the pushing portion 14b is about to separate from the pushed portion 4d. At the moment shown in FIG. 9, the driving member 5 is slightly rotated in the clockwise direction by the force of the strong driving spring 13 and the pressing spring 11, and its mounting portion 5c abuts on the end portion 9b ₁ of the iron piece shaft 9b. It is also the moment I did it.

Therefore, at this moment, due to the impact of the above-mentioned abutment, the force for separating the iron piece member 9 from the electromagnet largely works, but even if the timing is shifted, the pushing portion 14 is moved.
Even if c is separated from the pushed portion 5d, the pushing portion 19b of the pushing member 19 pushes the iron piece shaft 9b, so that it is not separated. As can be seen from this, the attraction force of the electromagnet 17 is not required to be able to withstand the impact force as described above, and the separation force applied by the drive spring 13 can be applied without applying the impact force. It will be good as long as it can withstand. Therefore, the power consumption can be saved, and the drive member 5 can be reliably held until the predetermined operation start time. After that, when the setting member 14 further rotates counterclockwise from the state of FIG. 9, at the next moment, the pushing portion 14b separates from the pushed portion 4d, and the leading blade driving member 4 becomes a strong driving spring. A slight clockwise rotation is caused by the force of 12 and the pressing spring 10.
Since the operation at this time and the effect thereof are the same as those of the trailing blade drive member 5 described above, the description thereof will be omitted.

On the other hand, as can be seen from FIG. 9, at this time,
The pin 14f of the setting member 14 is the end surface 1 of the pressing member 18.
8d and the end surface 22c of the transmission member 22 are completed, and the sliding contact relationship between the end surface 18c and the end surface 22b is reached, so that the pushing portions 14c and 14b of the setting member 14 are moved as described above. After being separated from the driven parts 5d, 4d of the drive members 5, 4, the pressing members 18, 19 are allowed to rotate in the counterclockwise direction by the urging force of the springs 20, 21. Thereby, the pressing portions 18b, 19b
The pressing of the iron piece members 8 and 9 by the
b and 19b are moved out of the operation loci of the iron piece members 8 and 9. However, the mounting portions 4c and 5c of the driving members 4 and 5 have already been attached to the end portions 8b ₁ and 9 of the iron piece members 8 and 9, respectively.
Since it is in contact with b ₁ , the above-mentioned shocking force is not generated, and the drive members 4 and 5 are reliably held at the initial position at which exposure travel starts. In this way, the setting member 14
FIG. 10 shows a state in which is returned to the initial position shown in FIG.

After that, when the power supply to the electromagnet 16 for the leading blade is cut off by the signal from the control circuit, the leading blade driving member 4 is rapidly rotated clockwise by the driving force of the strong driving spring 12. Therefore, the leading blade group that has expanded and covered the opening 1a is actuated by the drive pin 4b to open the opening 1a while deepening the overlap between the blades,
Drive downwards. Then, finally, the drive pin 4b collides with the cushioning member 2 to prevent the leading blade group from bouncing into the opening 1a, and then stops. When a predetermined time elapses after the leading blade driving member 4 starts the exposure traveling in this way, the power supply to the trailing blade electromagnet 17 is cut off. As a result, the trailing blade drive member 5 is driven by the drive spring 1
The rear blade group rotated clockwise by 3 and stored in the position above the opening 1a is actuated by the drive pin 5b and expands to close the opening 1a. Then, finally, the drive pin 5b collides with the buffer member 3 to prevent the rear blade group from bouncing and stop. FIG.
Indicates the state at this time.

In the structure of the above embodiment, the pressing member 19 is provided with the spring 21, but it may be provided with the transmission member 22. Further, the transmission member 22 is not essential depending on the arrangement, and the transmission member may be provided on the pressing member 18 side. Further, the bending portions 18a and 19a of the pressing members 18 and 19 are provided with elasticity.
The entire material 8 and 19 may be made of an elastic material. In that case, the springs 20 and 21 can be omitted. Further, in the embodiment, the shape of each pressing portion 18b, 19b is formed as a circular arc surface having a convex shape on the iron piece members 8, 9 side, but it may be a flat surface. However, from the standpoint of concentration of force, and the point of enabling smooth retreat prior to the exposure operation (the pressing part is in contact with the iron piece member for a long time while the camera is not in use, so depending on environmental conditions Since it may have adhesiveness), it is preferable to use an arc surface or a spherical surface. In that case, it is not necessary to directly form the arcuate surface or the spherical surface on the pressing member, and it may be manufactured as a separate component and integrated with the pressing member.

FIG. 11 is for explaining a modification of the iron piece member 9 described above. Of course, the same can be said for the iron piece member 8. However, it is not necessary that both iron piece members 8 and 9 have the same shape. Further, in FIG. 11, since there is no possibility of causing confusion, the components and parts used in the above-described embodiment are used as they are. As shown in this figure, the iron piece 9a of the iron piece member 9
The shape of the iron core member 17a of the electromagnet 17 is the same as that of the above-mentioned embodiment. The difference is that the end 9b ₁ of the iron piece shaft 9b
In the shape of. In the above embodiment, the pressing member 19
The surface pressed by the pressing portion 19b is a flat surface, but in the case of FIG. 11, it is a spherical surface having a center point on the center line L of the suction portion. This surface has a certain meaning even if it is an arc surface. With such a surface, the pressing portion 18
In addition to the same effects as those described above with respect to the shapes of b and 19b, the iron core member 17a, the iron piece member 9, and the pressing member 1 are obtained.
Even if the contact relationship of 9 is slightly deviated, it is possible to make a smooth contact.

Next, according to the present invention, which is the same direct type, the pressing spring 1 is provided between the driving member and the iron piece member.
It will be described that the present invention can also be applied to a shutter in which 0 and 11 are not interposed. FIG. 12 (a) shows an example of Japanese Unexamined Patent Publication No. 4-62529.
This is substantially the same as FIG. 9 described in the publication. The shutter having this structure is described in detail in the above publication, but a brief description will be given here. However, the usage of terms and symbols should be done in a unique way.

A trailing blade driving member B is rotatably attached to an axis A provided upright on the shutter base plate. The driving member B has a hole B ₁ and a bent portion B _2, and a bending portion (driving pin) B ₃ for operating the rear blade group arranged at the back of the shutter base plate. An oscillating member C is rotatably attached to a shaft B ₄ erected on the back surface of the drive member B. A roller C ₁ is attached to the back side of the swing member C, and a bent portion C ₂ projects from the hole B ₁ to the front side of the drive member B. And roller C
Reference numeral ₁ is inserted in a long hole D formed in the shutter base plate. The drive spring E is hooked on a shaft F provided upright on the shutter base plate and a bent portion C ₂ , and directly applies an urging force to the swing member C. A shaft G is fixed to the bent portion B ₂ and an iron piece member H is attached thereto. The attracted surface of the iron piece member H is the upper left end surface.

FIG. 12A shows the set state of the shutter. Therefore, in this state, the attracted surface of the iron piece member H is in contact with the attracted surface of the electromagnet (not shown). Further, the driving member B is rotated counterclockwise via the swinging member C when a set member (not shown) pushes the roller C _1, and the attracted surface of the iron piece member H is of an electromagnet (not shown). While in contact with the suction surface,
The rotation is stopped. The setting member is slightly rotated even after the driving member B is stopped, and the relative position between the driving member B and the swinging member C is changed to the state shown in the figure. As can be seen from this, it can be said that in the structure of this shutter, the drive spring E fulfills the function of the pressing spring 11 in the above embodiment by providing the swing member C. Since this shutter is a direct type, this state is maintained by the setting member until the shutter is released.

By the way, such a shutter has been implemented by the applicant and is already known. In carrying out the implementation, the following configuration is adopted, although there is no detailed description in the publication because it has nothing to do with the invention described in the above publication. This point will be described with reference to FIG.
The reference numerals used are the same as those in FIG. That is, the iron piece member H shown in FIG.
It has a shape as shown in (b) and is rotatably attached to the shaft G. Therefore, the two bent portions B ₅ and B ₆ further bent from the bent portion B ₂ serve as a rotation stopper for the iron piece member H.

As described above, the reason why the iron piece member H is not fixed to the shaft G but is rotatable is that if the iron piece member H can rotate, the attracted surface of the electromagnet is attracted to the attracted surface even if there is an error in assembly. This is because the surface can be properly contacted. However, if the rotation is simply enabled, the position adjustment in the rotation direction is possible, but the adjustment in other directions, for example, the direction orthogonal to the rotation direction is impossible. Therefore, in the actual product, the iron piece member H is
In order to allow displacement in either direction, a gap S of about 0.1 mm is provided between the diameter of the hole of the iron piece member H and the diameter of the shaft G.

As described above, when the gap S is large, when the holding force of the electromagnet is small, the same problem as described above occurs. That is, when the electromagnet is energized by the shutter release and the setting member is retracted from the roller C ₁ , the swinging member C is rotated counterclockwise by the drive spring E, and the bent portion C ₂ hits the edge of the hole B _1. The driving member B slightly rotates clockwise, and the shaft G abuts against the inner wall of the hole of the iron piece member H (the wall opposite to the wall which has been pushed toward the electromagnet), and the impact force is applied to the iron piece member H. Will be given. The influence of such an impact force can be prevented by providing a pressing member that presses the iron piece member H in the electromagnet direction until after the setting member retracts. Therefore, the present invention can be applied to such a shutter. As will be understood from this description, in the present invention, a roller may be used as each pushing portion or each pushed portion, if necessary.

[0039]

As described above, according to the present invention, in the direct type focal plane shutter, when the set member is returned to the initial position prior to exposure traveling, the driving member is released by releasing the pressing force of the set member. When the actuator slightly moves to the exposure operation start position, the force that contacts the iron piece member does not separate the iron piece member from the electromagnet due to the operation, so the traveling timing of the drive member is properly maintained. It is possible to save power consumption.

[Brief description of drawings]

FIG. 1 is a plan view of an example, showing an exposure traveling completed state of each blade group.

FIG. 2 is a plan view for explaining a supporting structure of each blade group in the present embodiment.

FIG. 3 is a plan view of the embodiment, showing a movement start state of the front side pressing member.

FIG. 4 is a plan view of the embodiment, showing a movement start state of the rear side pressing member.

FIG. 5 is a plan view of the embodiment, showing a state where the leading blade driving member has been set.

FIG. 6 is a plan view of the embodiment, showing a state in which setting of the trailing blade drive member is completed.

FIG. 7 is a plan view of the embodiment, showing a completed state of the set operation.

FIG. 8 is a plan view of the embodiment, showing the moment when the set member is about to separate from the trailing blade drive member in the returning operation of the set member.

FIG. 9 is a plan view of the embodiment, showing the moment when the set member is about to separate from the leading blade drive member in the returning operation of the set member.

FIG. 10 is a plan view of the embodiment, showing a state where the setting member has completely returned to the initial position.

11A and 11B are drawings for explaining a modification of the iron piece member shown in the present embodiment, in which FIG. 11A is a plan view and FIG.
1 (b) is a bottom view of FIG. 11 (a).

12A and 12B are drawings for explaining a known shutter configuration to which the present invention can be applied, in which FIG. 12A is a plan view and FIG. 12B is a perspective view of a main part of FIG. 12A. It is a figure.

[Explanation of symbols]

1 shutter base plate 4 leading blade driving member 4b, 5b driving pin 4c, 5c mounting portion 4d, 5d pushed portion 5 trailing blade driving member 8, 9 iron piece member 8a, 9a iron piece 8b, 9b iron piece shaft 8b ₁ , 9b ₁ end Parts 10, 11 Holding springs 12, 13 Drive springs 14 Set members 14b, 14c Pushing parts 14d Projections 14f, 22a Pins 16, 17 Electromagnets 16a, 17a Iron core members 18, 19 Pressing members 18a, 19a Bending parts 18b, 19b Pressing part 18c, 18d, 22b, 22c End surface 19c Long hole 22 Transmission member

Claims (7)

[Claims] 1. A drive member having a pushed portion for urging a drive spring to perform exposure traveling of a blade group, and an attracted surface capable of being attracted to an attracting surface of an electromagnet. It has an iron piece member attached to the drive member so that the relative positional relationship can be changed, and a pushing portion capable of engaging with the pushed portion, and the pushing portion pushes the pushed portion at the time of setting. A set member configured to return to the initial position prior to the exposure traveling of the blade group after energizing the electromagnet after release by operating the drive member against the drive spring, and the attracted object in the set state. The iron piece member is pressed so that its surface is in contact with the attracting surface, and when the setting member returns to the initial position, the pushing portion moves away from the pushed portion and then retreats from the operating trajectory of the iron piece member. And a pressing member adapted to A focal-plane shutter that features 2. Between the drive member and the iron piece member,
The focal plane shutter according to claim 1, further comprising a pressing spring that is tensioned by pressing the attracted surface against the attracted surface in a set state. 3. The driven member is provided on a swing member attached to the drive member, and the drive spring biases the drive member via the swing member. The focal plane shutter according to claim 1. 4. The focal plane shutter according to claim 1, wherein the pressing member is operated in conjunction with the operation of the setting member. 5. The focal plane according to claim 1, wherein the pressing member has an elastic portion, and the elasticity acts on the pressing of the iron piece member. Shutter. 6. The surface of the pressing member for pressing the iron piece member is formed into a convex spherical surface or an arc surface with respect to the iron piece member. The focal-plane shutter described in Crab. 7. The surface of the iron piece member to be pressed by the pressing member is formed into a convex spherical surface or an arc surface with respect to the pressing member. The focal-plane shutter described in Crab.