JPH09269525A - Focal plane shutter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the accuracy of a shutter, irrespective of the number of times of driving the shutter by providing a bent part on a shutter driving arm and bending the arm in a direction of separating from an adjacent substrate. SOLUTION: A front curtain follower arm 15 is inserted into a pin X1 , a bent part 15a is installed, the bent part 15a is constituted so that the bent projecting part may face to a 1st substrate 30 and the bent recessed part may face to a front curtain group 10. The other end of the arm 15 with reference to the pin X1 insertion part is bent as long as a distance (d) in the direction of separating from the 1st substrate 30. In the same way, a rear curtain follower arm 25 is provided with a bent part 25a, and the bent projection part faces to a 2nd substrate 31 and the bent recessed part faces to a rear curtain group 20. The other end of the arm 25 with reference to a pin X3 insertion part is bent as long as a distance (d) in a direction of separating from the 2nd substrate 31. Then, the arms 15, 25,... separately provided with bent parts 15a, 25a,... are bent in the direction of separating from the substrates 30 and 31.

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 device used in an image pickup device (for example, a camera or an electronic still camera).

[0002]

2. Description of the Related Art In a conventional focal plane shutter device, all the driving arms for driving the shutter blades have a straight shape.

[0003]

In recent years, in order to meet the demands of users for realizing more precise images and new image expression, improvement in film sensitivity, higher shutter speed and higher accuracy are required. ing. However, when the shutter arm is straight like the conventional shutter device, the change in the curtain speed (moving speed of the shutter blades) increases with the increase in the number of operations, and the decrease in the shutter accuracy due to the number of operations increases. There was a problem of being lost.

[0004]

In order to solve the above problems, according to the present invention, the bending arms (15a, 16b) are attached to the drive arms (16, 26 or 15, 16, 25, 26) for driving the shutter blades. ,twenty five
a, 26b) are provided so that the convex portion (mountain portion) of the bent portion faces the adjacent shutter substrate side (the side facing the side opposite to the blade attached to the drive arm).

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an exploded perspective view of a focal plane shutter device, showing the positional relationship of the respective constituent elements. As shown in FIG. 1, a light blocking plate 41 and an intermediate plate 42 are provided between the first substrate 30 located on the lens side and the second substrate 31 located on the film side, and the light blocking plate 41 is on the first substrate side, respectively. The intermediate plate 42 is arranged on the second substrate 31 side. Further, the front curtain group 10 is accommodated between the light shielding plate 41 and the first substrate 30, and the rear curtain group 20 is accommodated between the intermediate plate 42 and the second substrate.

The first substrate 30 and the second substrate 31 are provided with openings (exposed openings) 30a, 31a for passing light rays for exposing to the film, respectively. The openings 30a, 31 are also formed in the light shield plate 41 and the intermediate plate 42.
Apertures (exposed apertures) 41a and 42a for passing light rays are provided at positions substantially the same as a. The front curtain group 10 includes a plurality of (four) divided blades (light-shielding blades) 11 to 1.
4, including a leading curtain main arm (driving arm, first driving arm) 16 and a leading curtain slave arm (driving arm, second driving arm) 15. The front curtain group 10 has an opening 3
It is movable between an open position (open state) where 0a and 31a are opened to enable exposure to the film and a shield position (shielded state) where the openings 30a and 31a are covered to prevent exposure of the film. is there. As shown in FIG. 2, the front curtain sub-arm 15 and the front curtain main arm 16 are rotatably connected (supported) to pins X ₁ and X ₂ , respectively, which are embedded in the first substrate 30.

The split blades 11 to 14 are rotatably connected to the leading blade slave arm 15 and the leading blade main arm 16 by caulking pins 17a to 17d and 18a to 18d, respectively. A drive shaft 51 is attached to the hole 16a on the front curtain main arm 16, and the drive shaft 51 is a well-known drive mechanism (not shown) attached to the first substrate 30 and the first substrate. A circular arc groove 30b formed in 30 is penetrated and connected. Then, in response to the driving force from this driving mechanism, the driving shaft 51 moves in the circular arc groove 30b. With the movement of the drive shaft 51, the front curtain group 10 is divided into the divided blades 11-14.
The folded state (open state) and the divided blades 11 to 1
4 changes to a developed state (light-shielded state), and the openings 30a and 31a are opened and closed by the change.

The drive shaft 51 is braked by contacting a known brake mechanism (not shown) near the end of its exposure operation. As shown in FIG. 3, the rear curtain group 20 also includes a plurality of (four) divided blades (light shielding blades) 21 to 24. The split blades 21 to 24 have crimp pins 27a to 27d, 28.
a to 28d (shown in FIG. 2) are rotatably connected to the trailing blade slave arm 25 and the trailing blade main arm 26, respectively. The trailing blade follower arm 25 is rotatably connected to the pin X ₃ planted on the shutter first substrate 30, and the trailing curtain main arm 26 is rotatable on the pin X ₄ planted on the first substrate 30. It is connected.

A drive shaft 52 is attached to the hole 26a of the rear curtain main arm 26, and this drive shaft 52 is also an arc groove formed in the drive mechanism (not shown) and the first substrate 30 as is well known. 30c is penetrated and connected. Then, the drive shaft 52 receives the drive force from this drive mechanism, and the arc groove 3
Move in 0c. With the movement of the drive shaft 52, the rear curtain group 20 changes between a state in which the divided blades 21 to 24 are folded (open state) and a state in which the divided blades 11 to 14 are expanded (light shielding state), Due to the change, the openings 30a and 31a
Open and close.

The drive shaft 52 comes into contact with a known brake mechanism (not shown) and is braked near the end of its exposure operation. Further, the circular arc grooves 30b and 30c are also formed on the second substrate 31.
The circular arc grooves 31b and 31c are provided at the same positions as in, to prevent interference with the drive shafts 51 and 52. The operation of the shutter device configured as above will be described.

First, the drive shaft 51 in FIG. 2 is moved downward along the circular arc groove 30b of the first shutter substrate 30 by the above-mentioned drive mechanism. As a result, the first curtain slave arm 1
5. The front curtain main arm 16 moves, and with the movement of the arm, the divided blades 11 to 14 of the front curtain 10 start the traveling operation from the expanded state (light-shielding position) in FIG. As shown in the figure, it is placed under the opening 30a of the first substrate 30 (open position), and the exposure operation is started.

Then, after a certain time has passed after the front curtain group 10 started running,
The drive shaft 52 moves downward along the circular arc groove 30c. As a result, the trailing blade slave arm 25 and the trailing blade main arm 26 move, and along with the movement of the arms, the divided blades 21 of the trailing blade group 20.
3 to 24 start the traveling operation from the state (open position) overlaid on the upper side of the opening 30a to the expanded state (light shielding position) shown in FIG. 3, and the exposure operation ends.

The drive shafts 51 and 52 come into contact with a braking mechanism (not shown) in the vicinity of the end of the exposure operation thereof and are given a braking force to end the traveling. After the end of the exposure operation, a charging operation is performed by a charging mechanism (not shown), and the state returns to the state shown in FIG. FIG. 4 is a sectional view taken along the line AA of FIG.
0 is a line that sequentially connects the pin X ₂ and the crimping pins 18a to 18d, and the rear curtain group 20 is a line that sequentially connects the pin X ₄ and the crimping pins 28a to 28d. The cross section is shown.

In FIG. 4, a collar 19 is attached to the front curtain main arm 16, and this collar 19 is inserted into the pin X ₂ . Further, the front curtain main arm 16 is provided with a bent portion 16b between the mounting portion of the collar 19 and the caulking pin 18a. In this bent portion 16b, the bent convex portion (mountain portion) faces the first substrate 30, and the bent concave portion (valley portion).
Are configured to face the front curtain group 10.

As shown in FIG. 4, the arm 16 includes a collar 1
With respect to the mounting portion of 9, the other end side is away from the first substrate 30 (toward the dividing blades 11 to 14).
It is bent by the length d. Similarly, a collar 29 is attached to the rear curtain main arm 26, and this collar 29 is pin X.
Inserted in ₄ . The rear curtain main arm 26 is provided with a bent portion 26b between the mounting portion of the collar 29 and the caulking pin 28a. The bent portion 26b is configured such that the bent convex portion (mountain portion) faces the second substrate 31 and the bent concave portion (valley portion) faces the rear curtain group 20.

As shown in FIG. 4, the arm 26 includes a collar 2
The other end side is bent by the length d in the direction away from the second substrate 31 (in the direction toward the divided blades 21 to 24) with respect to the 9 mounting portion. 5 is a cross section taken along the line AA of FIG.
Regarding the front curtain group 10, pin X ₁ and caulking pins 17a to ₁
7d sequentially connecting line to the pin X ₃ with respect to the rear curtain group 20, sequentially connecting line caulking pins 27a-27d, shows a cross section of the rear curtain slave arm 25 and Sakimaku従arm 15.

In FIG. 5, the front curtain follower arm 15 is inserted into the pin X ₁ . A bent portion 15a is provided between the pin X ₂ insertion portion and the crimping pin 17a. The bent portion 15 a is configured such that the bent convex portion (mountain portion) faces the first substrate 30 and the bent concave portion (valley portion) faces the front curtain group 10. The arm 15 is bent by the length d in the direction away from the first substrate 30 (toward the dividing blades 11 to 14) with respect to the pin X ₁ insertion portion.

Similarly, the trailing blade follower arm 25 is also inserted into the pin X ₃ . A bent portion 25a is provided between the pin X ₃ insertion portion and the crimping pin 27a. The bent portion 25 a is configured such that the bent convex portion (mountain portion) faces the second substrate 31 and the bent concave portion (valley portion) faces the rear curtain group 20. The arm 25 is bent by the length d in the direction away from the second substrate 31 (in the direction toward the divided blades 21 to 24) with respect to the pin X ₃ insertion portion. In this way, the leading curtain main arm 16 and the leading curtain slave arm 1
5, the rear-curtain main arm 26, and the rear-curtain sub-arm 25 respectively include the bent portions 15a, 16b, 25a, and 2 as described above.
6b is provided, and the arms are bent in a direction away from the first substrate 30 or the second substrate 31, respectively, as described above, so that the caulking pins 17a to 17d and 18a to 1 are formed.
8d, 27a to 27d, 28a to 28d, and the first substrate 3
It is possible to prevent the occurrence of friction between 0 and the second substrate 31, and as a result, it is possible to improve the operational stability of the front curtain group 10 and the rear curtain group 20. As is clear from FIGS. 4 and 5, the above-mentioned bent portions (15a, 16a)
b, 25a, 25b) are drive arms (15, 16, 2).
5, 26) are pivotally supported by the shutter substrate (30, 31) via the pins (X _{1 to} X ₄ ), respectively, and the drive arm (15, 16, 25, 26) has a plurality of divided blades (11).
˜14, 21-24) and the position closest to the position pivotally supported by the shutter substrate (the drive arms are respectively connected to the pins 17a, 18a, 27a, 28a,
It is provided between the blade 14 and the position supporting the blade 24). FIG. 6 shows that the shutter curtain speed (the time from when the front curtain group 10 starts to open the opening portion 30a to when it is completely released, or the rear curtain group 2 is shown) as the number of shutter operations increases.
It is the result of an experiment on how the change amount of 0) from the time when the opening 30a starts to be closed to the time when the opening 30a is completely closed changes.

As a result of this experiment, in the conventional type (when all the blade drive arms have no bent portions and are formed straight), the amount of change in the shutter curtain speed increases as the number of shutter operations increases. There is. On the other hand, when the present invention is applied (arms 15, 16, 2)
It has been found that the amount of change in the shutter curtain speed can be made smaller than that of the conventional type in the case where the bent portions are provided in Nos. 5 and 26).

The amount of change in the curtain speed when the shutter is operated 100,000 times is 60 to 10 when all the arms (the front curtain arm and the rear curtain arm) are straight.
While it was 0 μs, it was 30 to 50 μs in the configuration of this example (the configuration in which the bent portions are provided in all the arms). Here, as the range of d, 0.05 mm to 0.5 m
It was confirmed that m is more effective, and more preferably 0.05 mm to 0.3 mm. FIG. 7 shows a second embodiment of the present invention.
It is a figure which shows a part of embodiment of FIG. The difference from the first embodiment (FIGS. 4 and 5) is that the above-mentioned bent portions 15a and 25a are not provided in the slave arms 15 and 25 (the shape of the slave arms 15 and 25 is a straight shape). ). That is, in the second embodiment, the main arms 16, 26
The structure relating to the slave arms 15 and 25 is the same as that shown in FIG. 4, but the structure relating to the slave arms 15 and 25 is as shown in FIG.

As a result of the experiment, substantially the same operational effect as that of the first embodiment was obtained even with the configuration of the second embodiment (the experimental result diagram of the second embodiment is shown in FIG. 6). Omitted because it was almost equivalent to).

[0022]

As described above, according to the present invention, the shutter drive arm is provided with the bending portion (the bending convex portion faces the substrate side, and the bending concave portion faces the shutter blade side), and the arm is provided. By bending in a direction away from the adjacent substrate, the stability of the blades during traveling is improved, and the change in the curtain speed due to the number of times the shutter is operated can be reduced. As a result, regardless of the number of shutter operations
The shutter accuracy can be stabilized.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of components of a focal plane shutter according to the present invention.

FIG. 2 is a plan view of a focal plane shutter showing a charge completed state.

FIG. 3 is a plan view of a focal plane shutter showing a state at the end of an exposure operation.

FIG. 4 is a cross-sectional view taken along the line AA of FIG. 2 in the first and second embodiments of the present invention.

FIG. 5 is an AA of FIG. 2 in the first embodiment of the present invention.
It is sectional drawing.

FIG. 6 is a diagram showing the relationship between the number of shutter operations and the amount of change in shutter curtain speed.

FIG. 7 is an AA of FIG. 2 in the second embodiment of the present invention.
It is sectional drawing.

[Explanation of symbols]

 10 Leading Curtain Group 11-14 Dividing Blades of Leading Curtain Group 15-16 Leading Curtain Arm 20 Trailing Curtain Group 21-24 Dividing Blades of Trailing Curtain Group 25-26 Trailing Curtain Arm 30 First Substrate 31 Second Substrate 41 Shading Plate 42 Intermediate plate

Claims (4)

[Claims] 1. A shutter blade, a shutter substrate, and a drive arm that supports the shutter blade and is movably provided on the shutter substrate to drive the shutter blade. A focal plane shutter device comprising: a bent portion having a peak portion on a side facing the shutter substrate and a valley portion on a side facing the shutter blade. 2. The focal plane shutter device according to claim 1, wherein the drive arm is bent and provided in a direction away from the shutter substrate on which the drive arm is axially supported. 3. The focal plane shutter device according to claim 1, wherein the bending amount of the arm is 0.05 to 0.5 mm on the other end side with respect to the supporting portion side of the substrate. 4. The shutter blade includes a plurality of divided blades, the drive arm supports the plurality of divided blades at different positions, and the bending portion has the drive arm axially supported by the shutter substrate. 2. The focal point according to claim 1, wherein the focal point is provided between a position where the drive arm supports the split blade and a position which is closest to a position pivotally supported by the shutter substrate. Plain shutter device.