JP3662993B2 - Focal plane shutter for camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a focal plane shutter for a camera in which a leading blade driving member and a trailing blade driving member are attracted and held by respective electromagnets, and the attraction is released in order to cause a shutter blade to perform exposure running. .
[0002]
[Prior art]
Two types of focal plane shutters of this type are known as a method of holding the leading blade driving member and the trailing blade driving member at the set position. One of the types is commonly called a locking type. When the leading blade driving member and the trailing blade driving member are moved to the set position by the setting member, the two driving members are provided separately. The locking member is locked at that position. At the same time, the iron piece member is placed in contact with the electromagnet and held in an attractable state. Therefore, the set member is immediately returned to the original position when the leading blade driving member and the trailing blade driving member are set.
[0003]
The other type is commonly referred to as the direct type, and an iron piece member is attached to each driving member, and the leading blade driving member and the trailing blade driving member are each in the set position. Is simply brought into contact with each electromagnet. Therefore, when the set member is returned to the original position from this state, each drive member is also returned. Therefore, the set member is not returned immediately, and each iron piece member is attracted and held by each electromagnet at the shutter release. It is returned to its original position later and before being released. Accordingly, this type is advantageous in terms of space and cost because it does not require a locking member or the like as compared with the former, and is also advantageous in terms of adjustment work between related parts. It has the characteristics. The present invention relates to such a latter type of shutter.
[0004]
By the way, in shutters that change the timing of release by the electromagnet and control the exposure time, if foreign matter such as dust, water droplets, or oil adheres to the attracting surface of the electromagnet or the attracted surface of the iron piece member, it is released. The timing is shifted, and the regular exposure time cannot be obtained. And, foreign matter adheres in this way is overwhelmingly more after the final inspection of the shutter itself is completed and before it is incorporated into the camera than after the shutter is incorporated into the camera. For this reason, a shutter with a dust cover attached to a single shutter has been proposed, and part of it has been implemented.
[0005]
[Problems to be solved by the invention]
However, the dustproof cover as described above does not completely seal the entire shutter. Nevertheless, in the above-described locking type shutter, if the shutter is set in a set state, there is less possibility of foreign matter adhering between the attracting surface of the electromagnet and the attracted surface of the iron piece member, and the dustproof as described above. If you have a cover, you can prevent it. However, in the direct type shutter, the electromagnet is not energized except during shooting, and the electromagnet attracting surface and the attracted surface of the iron piece member are naturally separated from each other, and both surfaces are exposed to the air. There is. Therefore, the conventional dustproof cover alone is not sufficiently effective.
[0006]
The present invention has been made to solve such problems, and the object of the present invention is to use a so-called direct type shutter in which an electromagnet attracting surface and an iron piece member are attracted before being incorporated into a camera. To provide a focal plane shutter for a camera that prevents foreign matter from adhering to the surface.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention operates by releasing from the respective electromagnets, leading blade driving members and trailing blade driving members that cause the leading blade group and the trailing blade group to perform exposure running, and shutter charging. A set member for setting the both drive members at positions where they can be attracted by the respective electromagnets is rotatably attached to the shutter base plate, and the set members are respectively connected to the respective drive members when the shutter is released. In the focal plane shutter that is returned from the set completion position to the original position after being attracted and held by the electromagnet and released, the shutter base plate and the set member are engaged with one of them. means, other in advance provided engaged means, in the stage before incorporating the focal plane shutter in the camera, the original position the setting member Yuki by al rotated, said at a position rotated further than the set completion position while maintaining the set state of the two drive members, the engagement means and該被engagement means is engaged, the original of the set member The return to the position can be prevented.
[0008]
In the focal plane shutter for a camera according to the present invention, preferably, the engaging means is a hole or a depression, and the engaged means is a protrusion fitted therein.
In the focal plane shutter for a camera according to the present invention, preferably, the protrusion is formed of a separate member and is urged in a direction of fitting into the hole or the recess.
Further, in the focal plane shutter for a camera according to the present invention, preferably, the engaged means is integrally formed with the shutter base plate or the set member with a resin.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to three illustrated examples. FIG. 1 is an exploded perspective view of the first embodiment. 2 to 4 are plan views of the main part of FIG. 1, FIG. 2 shows a locked state of each driving member, FIG. 3 shows a set state, and FIG. 4 shows a state immediately after the exposure operation is finished. FIG. 5 is a cross-sectional view of the main part of FIG. FIGS. 6 to 8 are plan views of main parts of the second embodiment. FIG. 6 shows a locked state of each drive member, FIG. 7 shows a set state, and FIG. 8 shows a state immediately after the exposure operation is finished. FIG. 9 is a cross-sectional view of the main part of FIG. FIG. 10 is a sectional view of an essential part of the third embodiment. Note that, in these examples, different reference numerals are used for different parts and different parts, but the same reference numerals are used for substantially the same parts and the same parts.
[0010]
A first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, an aperture 1a for exposure and arc-shaped slots 1b, 1c are formed on a shutter base plate 1 made of synthetic resin, and shafts 1d, 1e, 1f are erected by integral molding. These shafts 1d, 1e, and 1f are formed with a spacer portion, a large diameter portion, and a small diameter portion from the formation surface side of the aperture 1a, and a screw hole is formed in the axial direction at the tip of the small diameter portion of the shafts 1d and 1e. Is formed. A leading blade driving member 2 and a trailing blade driving member 3 are rotatably attached to the large diameter portions of the shafts 1d and 1e. Each drive member 2 and 3 is made of synthetic resin, and cylindrical portions 2a and 3a, iron piece attachment portions 2b and 3b, and drive pins 2c and 3c are formed by integral molding, and the iron piece attachment portions 2b and 3b have electromagnets. The iron pieces 4 and 5 to be adsorbed on are attached.
[0011]
The drive pins 2c and 3c pass through the slots 1b and 1c, and are connected to a well-known front blade group and rear blade group (not shown) on the back side of the shutter base plate 1, and the front blade drive member 2 and the rear The blade driving member 3 sequentially rotates clockwise to cause each blade group to perform exposure travel. The slots 1b and 1c are fitted with buffer pieces 6 and 7 made of butyl rubber, and the drive pins 2c and 3c are brought into contact with the end of the clockwise rotation to prevent bouncing. .
[0012]
A set lever 8 is rotatably attached to the large-diameter portion of the shaft 1f, and is rotated clockwise in conjunction with the winding of the film, and is accurately shown enlarged in FIGS. As described above, the pushing portions 8a and 8b push the pushed portions 2d and 3d to rotate the leading blade driving member 2 and the trailing blade driving member 3 counterclockwise to the set position. The set lever 8 is provided with a return spring that urges counterclockwise. Further, the set lever 8 has a recess 8c formed on the surface facing the shutter base plate 1, and a projection 1g formed integrally with the shutter base plate 1 can be fitted into the recess 8c. Yes.
[0013]
Ratchet gears 9 and 10 are rotatably attached to the small diameter portions of the shafts 1d and 1e. The drive springs 11 and 12 are loosely fitted in the cylinder portions 2a and 3a of the leading blade driving member 2 and the trailing blade driving member 3 in a non-contact state. 2 and a spring hook (not shown) formed on the rear blade driving member 3, and the other end is hooked on a slit (not shown) formed on the ratchet gears 9 and 10.
[0014]
The electromagnet mounting plate 13 and the printed wiring board 14 are overlapped so that the holes 13a and 14a are the small diameter portion of the shaft 1d, the holes 13b and 14b are the small diameter portion of the shaft 1e, and the holes 13c and 14c are the shafts. It is fitted by screwing screws 15 and 16 into screw holes formed at the tips of the shafts 1d and 1e, after fitting into the small diameter portion of 1f. The mounting plate 13 is made of metal, and ratchet claws 13d and 13e are formed by bending. These ratchet claws 13d and 13e are adapted to mesh with the ratchet gears 9 and 10, so that the force of the drive springs 11 and 12 can be adjusted by rotating the ratchet gears 9 and 10 and changing their meshing relationship. It has become.
[0015]
The leading blade control electromagnet and the trailing blade control electromagnet are respectively substantially U-shaped iron cores 17, 18, bobbins 19, 20 fitted to one leg of the iron cores 17, 18, The coils 21 and 22 are wound around the bobbins 19 and 20, and the pair of terminal pins 21 a and 22 a of the coils 21 and 22 are press-fitted into the bobbins 19 and 20. The pair of holes 14d and 14e are inserted and soldered. Further, the iron cores 17 and 18 are attached to iron core attachment seats 23 and 24 fixed to bent portions of the attachment plate 13 by screws 25 and 26. The cover 27 is attached to the side position of the aperture 1a by fitting the upper and lower convex portions 27a and 27b into the long hole 14f of the printed wiring board 14 and the long hole 1h of the shutter base plate 1.
[0016]
Next, the operation of this embodiment from the shutter set position will be described. The set state in this embodiment is shown in FIG. In this state, the set lever 8 is held in this posture by a member on the camera body side. Therefore, the leading blade driving member 2 and the trailing blade driving member 3 press the respective iron pieces 4 and 5 against the iron cores 17 and 18. However, the coils 21 and 22 are not energized and are not magnetically attracted. In this state, the shaft 1g of the shutter base plate 1 and the recess 8c of the set lever 8 are in a disengaged state. Although not shown because it is well known, the iron pieces 4 and 5 are attached to the iron piece attaching portions 2b and 3b so as to be biased toward the iron cores 17 and 18 by a spring.
[0017]
When the shutter is released, the coils 21 and 22 of both electromagnets are first energized, and the iron cores 17 and 18 attract the iron pieces 4 and 5. Then, the set lever 8 is released from the holding force by the member on the camera body side, performs a return operation, and stops at the position shown in FIG. Since this returning operation is performed in the counterclockwise direction, the disengaged state between the shaft 1g and the recess 8c is maintained. After that, when the coil 21 is de-energized, the leading blade driving member 2 is rotated clockwise by the driving spring 11, and the leading blade (not shown) is driven by the driving pin 2c to open the aperture 1a. Go. Thereafter, when the coil 22 is de-energized at a predetermined timing according to the subject light, the rear blade drive member 3 is rotated clockwise by the drive spring 12, and the rear blade (not shown) is driven by the drive pin 3c. Run and close aperture 1a. FIG. 4 shows the state at that time.
[0018]
When shooting is completed as described above, the set lever 8 is rotated clockwise from the position shown in FIG. 4 in conjunction with the winding of the film. Therefore, the pushing part 8a of the set lever 8, 8b is, the pushing portion 2d, press 3d, each of the driving member 2 is rotated against the drive spring 11 in the counterclockwise direction. The rotation of the set lever 8 stops when the driving members 2 and 3 reach the position shown in FIG. 3 and the iron pieces 4 and 5 are brought into contact with the iron cores 17 and 18. This state is held by a member on the camera body side until the next shutter release is performed.
[0019]
When the shutter having such a configuration is incorporated in the camera, the member on the camera body side regulates the position of the set lever 8 as described above. However, the shutter is manufactured as a single unit and incorporated in the camera. In the state before the operation, there is no member that regulates in such a manner, so that the driving members 2 and 3 on which the strong driving springs 11 and 12 are hung rotate in the clockwise direction, and the state shown in FIG. 4 is obtained. End up. Therefore, in such a state, foreign matters such as dust are very easily attached to the attracted surfaces of the iron pieces 4 and 5 and the attracted surfaces of the iron cores 17 and 18.
[0020]
Therefore, in this embodiment, the outer peripheral surfaces of the pushing portions 8a and 8b of the set lever 8 are formed to be concentric with the shaft 1f as the center. Therefore, the set lever 8 can be further rotated in the clockwise direction from the position shown in FIG. 3 without substantially affecting the contact relationship between the iron pieces 4 and 5 and the iron cores 17 and 18. . Accordingly, FIGS. 2 and 5 show a state in which the set lever 8 is rotated in the clockwise direction and the recess 8c of the set lever 8 is fitted to the shaft 1g of the shutter base plate 1. FIG. As a result of such a configuration, the iron pieces 4 and 5 and the iron cores 17 and 18 can be easily kept in contact with each other even before being incorporated in the camera, and foreign matter can be prevented from adhering.
[0021]
In the above, when the recess 8c is fitted to the shaft 1g, the set lever 8 is slightly shifted upward in FIG. 5 and the both are aligned, and then the set lever 8 is lowered. If a taper surface up to the recess 8c is formed on the lower surface of the set lever 8, the taper surface is gradually pushed up at the tip of the shaft 1g as the set lever 8 rotates, and the recess 8c is positioned at the position of the shaft 1g. When reaching, the set lever 8 can be lowered to be in a fitted state. In that case, it is advantageous to allow the return spring (not shown) hung on the set lever 8 to be urged downward with respect to the set lever 8. When incorporating the camera into the camera, the locking relationship between the two can be solved by slightly lifting the set lever 8.
[0022]
Next, the second embodiment shown in FIGS. 6 to 9 will be described. These drawings show states corresponding to FIGS. 2 to 5 of the first embodiment. In the present embodiment, the arrangement of the shaft 1g and the recess 8c in the first embodiment is reversed, and the other configurations and operations are the same as those in the first embodiment. I will explain only. In this embodiment, a shaft 8d is formed on the set lever 8, and a recess 1i is formed on the shutter base plate 1.
[0023]
In addition, after the shutter is incorporated into the camera, the presence of the shaft 8d becomes an obstacle to the operation of the set lever 8, so that the arc base groove 1j is formed in the shutter base plate 1 for escape. As shown in the first embodiment, in FIG. 6 to FIG. 8, if a tapered portion is formed between the lower end of the groove 1j and the recess 1i so as to gradually become shallower from the depth position of the groove 1j. The fitting state (locked state) between the shaft 8d and the recess 1i can be easily obtained.
[0024]
In addition, you may form said hollow 1i and groove | channel 1j as a hole which penetrated the shutter base plate 1, and this can be said also about the hollow 8c in 1st Example. In this embodiment, the recess 1i locks the shaft 8d. However, the shaft 8d is engaged by forming a flexible hook portion on the shutter base plate 1 or attaching another member instead. It can be stopped. This is also true for the first embodiment, but it is not very preferable to attach a separate member to the set lever 8. Furthermore, the shafts 1g and 8d to be locked are not particularly limited to the shaft shape.
[0025]
Next, a third embodiment will be described. In this embodiment, an independent shaft member having a special shape is attached to the shutter base plate 1 instead of the shaft 1g in the first embodiment. Accordingly, since the other points are the same as those in the first embodiment, the description thereof will be omitted. However, all the description applied to the first embodiment described above also applies to this embodiment. FIG. 10 is a cross-sectional view of the present embodiment shown corresponding to FIG. 5 of the first embodiment. The shape of the set lever 8 is substantially the same as that of the depression 8c having a slightly larger diameter. Have almost the same shape. The shutter base plate 1 is formed with two holes 1m and 1n penetrating from the counterbore 1k on the lower surface to the upper surface.
[0026]
A shaft member 28 is slidably fitted in the hole 1m. The shaft member 28 is configured by screwing a screw component to a plate component, and has a head portion 28a fitted in the recess 8c and a plate portion 28b contained in the counterbore portion 1k. And is biased upward by a spring 29. When the head portion 28a of the shaft member 28 is fitted into or removed from the recess 8c, tweezers or the like is inserted from the hole 1n and the plate portion 28b is pushed downward.
[0027]
However, such a configuration of the shaft member 28 is not necessarily advantageous in terms of the number of parts and the number of processing steps. Therefore, if the shaft member 28 is made of synthetic resin, gives elasticity to the plate portion 28b, and the right end thereof is attached to the shutter base plate 1, the spring 29 can be omitted. Furthermore, since the shutter base plate 1 is made of a synthetic resin, such a synthetic resin member can be manufactured integrally with the shutter base plate 1.
[0028]
【The invention's effect】
As described above, according to the present invention, in the so-called direct type focal plane shutter, the attracting surface of the electromagnet and the attracted surface of the iron piece member can be kept in contact with each other with a simple configuration. In addition, it is possible to prevent foreign matters such as dust from adhering to both surfaces.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a first embodiment of the present invention.
FIG. 2 is a plan view of an essential part of FIG. 1, showing a locked state of each drive member.
FIG. 3 is a plan view of the main part of FIG. 1, showing a set state of each drive member;
4 is a plan view of the main part of FIG. 1, showing a state immediately after the exposure operation of each driving member is completed.
5 is a cross-sectional view of the main part of FIG. 2;
FIG. 6 is a plan view of an essential part of a second embodiment of the present invention, showing a locked state of each drive member.
FIG. 7 is a plan view of an essential part of a second embodiment of the present invention, showing a set state of each drive member.
FIG. 8 is a plan view of an essential part of a second embodiment of the present invention, showing a state immediately after the exposure operation of each drive member is completed.
9 is a cross-sectional view of the main part of FIG.
FIG. 10 is a sectional view of an essential part of a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shutter base plate 1b, 1c Slot 1d, 1e, 1f, 1g, 8d Shaft 1i, 8c Depression 1j Groove 1k Counterbore part 1m, 1n Hole 2 Lead blade drive member 2a, 3a Tube part 2b, 3b Iron piece attaching part 2c, 3c Drive pin 2d, 3d Driven portion 3 Rear blade drive member 4, 5 Iron piece 6, 7 Buffer piece 8 Set lever 8a, 8b Push portion 17, 18 Iron core 28 Shaft member 28a Head portion 28b Plate portion 29 Spring

Claims (4)

A leading blade driving member and a trailing blade driving member that are operated by releasing from the respective electromagnets to cause the leading blade group and the trailing blade group to perform exposure travel, and at the time of shutter charging, the both driving members are placed at positions where they can be attracted by the respective electromagnets. The set members to be set are rotatably attached to the shutter base plate, and the set members are released after the both driving members are attracted and held by the respective electromagnets at the time of shutter release. In the focal plane shutter that is set to return to the original position from the set completion position,
The shutter base plate and the set member are provided with an engaging means on one of them and an engaged means on the other, and the set member is moved to the original position before the focal plane shutter is assembled into the camera. The engaging means and the engaged means are engaged with each other at a position further rotated from the set completion position while maintaining the set state of both the drive members. A focal plane shutter for a camera characterized in that the return to the position can be prevented. 2. The focal plane shutter for a camera according to claim 1 , wherein the engaging means is a hole or a depression, and the engaged means is a protrusion fitted therein . 3. The focal plane shutter for a camera according to claim 2 , wherein the projection is formed of a separate member and is urged in a direction of fitting into the hole or the recess . The focal plane shutter for a camera according to claim 1 or 2 , wherein the engaged means is integrally formed with the shutter base plate or the set member with resin .

Images