WO2018230591A1

WO2018230591A1 - Focal-plane shutter and imaging device

Info

Publication number: WO2018230591A1
Application number: PCT/JP2018/022527
Authority: WO
Inventors: 健太河上
Original assignee: 日本電産コパル株式会社
Priority date: 2017-06-16
Filing date: 2018-06-13
Publication date: 2018-12-20
Also published as: JP6887888B2; JP2019003091A

Abstract

This focal-plane shutter comprises: an abutting part (61a) of a blade reaching a travel end position, the abutting part (61a) abutting one side part on the travel-direction side and extending parallel to the surface of a shutter plate; and a shock-absorbing member (60) formed from rubber. The shock-absorbing member (60) comprises a shock-absorbing member body (61) having through-holes (62) that pass through the shock-absorbing member body (61) in a direction perpendicular to the direction in which the abutting part (61a) extends, and shock-absorbing auxiliary members (72) that are fitted into the through-holes (62) and are formed to have a hardness differing from that of the shock-absorbing member body (61).

Description

Focal plane shutter and imaging device

The present invention relates to a focal plane shutter and an imaging device.

In the focal plane shutter, in order to reduce the impact at the end of travel of the blade, a buffer member is provided at the travel end position of the blade. For example, Patent Document 1 discloses a focal plane shutter that has a sufficient amount of elastic deformation by forming a plurality of through holes in a direction perpendicular to the direction in which the contact portion of the buffer member extends.

JP2015-138259A

The buffer member of the focal plane shutter disclosed in the cited document 1 is composed of one buffer member, and the hardness of the buffer member is uniquely determined by the material used. Depending on the environment in which the focal plane shutter is used and the required durability, there are various conditions for the hardness required of the buffer member, and the buffer member disclosed in Patent Document 1 cannot meet such a requirement.

The present invention has been made in view of the above circumstances, and provides a focal plane shutter and an imaging apparatus including a buffer member having appropriate hardness according to the environment in which the focal plane shutter is used and the required durability. For the purpose.

In order to achieve the above object, a focal plane shutter according to the present invention comprises:
A ground plate in which an exposure opening is formed;
A blade member comprising at least one blade for opening and closing the exposure opening;
A driving member connected to the blade member and driving the blade member so that the blade opens and closes the exposure opening;
The blades that have reached the travel end position, abutting on one side of the traveling direction side, provided with a contact portion extending in parallel with the surface of the base plate, and comprising a buffer member formed of an elastic material,
The buffer member is
A buffer member body having at least one through-hole penetrating in a direction perpendicular to a direction in which the contact portion extends;
A buffering auxiliary member that fits into the through-hole and is formed with a hardness different from that of the buffering member main body.

The through hole may extend in the same direction as the direction in which the contact portion extends.

The through hole includes a first through hole and a second through hole,
The buffering auxiliary member may include a first buffering auxiliary member that fits into the first through hole and a second buffering auxiliary member that fits into the second through hole.

The hardness of the first buffering auxiliary member and the hardness of the second buffering auxiliary member may be different.

The blade member includes a rear blade group including a plurality of blades,
Of the plurality of blades of the rear blade group, a slit forming blade may contact the contact portion.

An image pickup apparatus according to the present invention includes the focal plane shutter.

According to the present invention, it is possible to provide a focal plane shutter and an imaging apparatus including a buffer member having appropriate hardness according to the environment in which the focal plane shutter is used and the required durability.

In the focal plane shutter which concerns on this Embodiment, it is a figure which shows the state which the front blade group closed the exposure opening before the shutter operation | movement start. It is a figure which shows the state which the front blade group drive | worked and the shutter operation | movement was complete | finished. It is a figure which shows the state which the rear-blade group drive | worked and the shutter operation | movement was complete | finished. FIG. 4 is a diagram showing a cut surface taken along line A-A ′ of FIG. 3. FIG. 4 is a diagram showing a cut surface taken along line B-B ′ of FIG. 3. It is the front view which expanded the buffer member. It is the side view to which the buffer member was expanded. It is a figure which shows an example of the combination of the hardness of a buffer member main body and a buffer auxiliary member. It is a figure which shows the other example of the combination of the hardness of a buffer member main body and a buffer auxiliary member. It is a figure which shows the other example of the combination of the hardness of a buffer member main body and a buffer auxiliary member. It is a figure which shows the other example of the combination of the hardness of a buffer member main body and a buffer auxiliary member. It is a figure which shows the other example of the combination of the hardness of a buffer member main body and a buffer auxiliary member.

Hereinafter, a focal plane shutter according to an example of an embodiment of the present invention will be described with reference to the drawings.

The focal plane shutter according to the present embodiment is provided in an imaging apparatus having an imaging element. The imaging device is, for example, a camera including a digital camera or a surveillance camera. The image sensor is, for example, a CCD (Charge-Couples-Device) or CMOS (Complementary-Metal-Oxide-Semiconductor) image sensor. The focal plane shutter is disposed on the optical axis from the optical system such as a lens to the image sensor.

The focal plane shutter 1 according to the present embodiment will be described with reference to FIGS. 1 to 3 are diagrams showing the shutter structure and operation, FIG. 4A is a diagram showing a cut surface taken along line AA ′ in FIG. 3, and FIG. 4B is a diagram showing BB in FIG. It is a figure which shows the cut surface cut | disconnected by a line. FIG. 5 is an enlarged view of the buffer member, FIG. 5A is a front view, and FIG. 5B is a side view. The front side in FIGS. 1 to 3 is the lens side, and the back side is the image sensor side.

With reference to FIG. 1, FIG. 4A, and B, the structure of the focal plane shutter 1 which concerns on this Embodiment is demonstrated. In FIG. 1, the buffer member is indicated by a solid line. 4A and 4B are cut views of the buffer member, but only the buffer holding member is hatched, and the other members are not hatched.

As shown in FIGS. 1, 4A, and B, the focal plane shutter 1 according to the present embodiment includes a shutter base plate 10, a leading blade group 20, a trailing blade group 30, an intermediate plate 40, and a cover plate 50. The buffer member 60 is provided.

A rear blade group 30, an intermediate plate 40, a front blade group 20, and a cover plate 50 are arranged in this order on the front side of the shutter base plate 10 in FIG. , A trailing blade driving member, a set member, a leading blade electromagnet, and a trailing blade electromagnet are disposed.

The shutter base plate 10 is a plate-like rectangular member formed of resin, and a horizontally long exposure opening 10a is formed at a substantially central portion thereof.

Two arc-shaped

long holes

10b and 10c are formed on the right side of the exposure opening 10a of the shutter base plate 10. Shafts 11a, 11b, 11c, and 11d are erected on the front surface of the shutter base plate 10, that is, on the lens side surface.

On the front side of the shutter base plate 10, as shown in FIGS. 4A and 4B, an intermediate plate 40 and a cover plate 50 are arranged at a predetermined interval. The space formed between the shutter base plate 10 and the intermediate plate 40 is a blade chamber of the rear blade group 30, and the space formed between the intermediate plate 40 and the cover plate 50 is the blade chamber of the leading blade group 20. Become. A buffer member 60 is attached to the front side of the shutter base plate 10.

In the intermediate plate 40 and the cover plate 50,

exposure openings

40a and 50a having the same shape as the exposure opening 10a of the shutter base plate 10 are formed, respectively. The exposure opening 10a, the exposure opening 40a, and the exposure opening 50a are each positioned so as to be aligned in the optical axis direction. Further, in each of the intermediate plate 40 and the cover plate 50, long holes having the same shape as the

long holes

10b and 10c of the shutter base plate 10 are formed and positioned so as to be aligned in the optical axis direction.

A buffer member made of an elastic material such as rubber (not shown) and having a substantially C-shaped planar shape is attached to the lower ends of the long hole 10b and the long hole 10c. This buffer member is a member for alleviating the impact by bringing the drive pin of the drive member into contact when the shutter operation ends.

In addition to this, the focal plane shutter 1 includes a leading blade driving member that drives the leading blade group 20 to perform a shutter operation so as to open the exposure opening 10a, and a trailing blade group that closes the exposure opening 10a. 30 includes a set member that sets the rear blade drive member, the front blade drive member, and the rear blade drive member that cause the shutter operation to 30 to the set position before the shutter operation. Furthermore, a front blade electromagnet for attracting and holding the front blade drive member at the set position and a rear blade electromagnet for attracting and holding the rear blade drive member at the set position are provided.

As shown in FIG. 1, the leading blade driving member includes a driving pin 21 for driving the leading blade group 20, and the trailing blade driving member includes a driving pin 31 for driving the trailing blade group 30. The drive pin 21 extends through the long hole 10 c to the blade chamber that houses the leading blade group 20, and engages with an engagement hole formed in the leading blade group 20. The drive pin 31 passes through the long hole 10 b, extends into a blade chamber that houses the rear blade group 30, and engages with an engagement hole formed in the rear blade group 30. The leading blade driving member drives the leading blade group 20 by driving the driving pin 21 in the long hole 10c. Similarly, the rear blade drive member drives the rear blade group 30 by driving the drive pin 31 in the long hole 10b.

The front blade group 20 is a mechanical front curtain shutter (front blade member) that travels in the blade chamber between the intermediate plate 40 and the cover plate 50. The leading blade group 20 includes four

blades

20a, 20b, 20c, and 20d, and leading

blade arms

20e and 20f that are connected to one end portions of these blades. A blade 20a connected to the leading edge of the

leading blade arms

20e and 20f is a slit forming blade that forms an exposure slit. From the intermediate plate 40 toward the cover plate 50, the blade 20d, the blade 20c, the blade 20b, the blade 20a, and the

leading blade arms

20e and 20f are arranged in this order.

The leading blade arm 20e is rotatably attached to the shaft 11b of the shutter base plate 10, and the leading blade arm 20f is rotatably attached to the shaft 11a of the shutter base plate 10. The driving pin 21 of the leading blade driving member is inserted into the long hole 10c of the shutter base plate 10, and the tip thereof is fitted in the engaging hole 20ff formed in the leading blade arm 20f.

The rear blade group 30 is a rear curtain shutter (rear blade member) that travels in the blade chamber between the shutter base plate 10 and the intermediate plate 40. As shown in FIG. 3, the rear blade group 30 includes four

blades

30 a, 30 b, 30 c, and 30 d and

rear blade arms

30 e and 30 f connected to one end portions of these blades. A blade 30d connected to the forefront of the

rear blade arms

30e and 30f is a slit forming blade that forms an exposure slit. The

rear blade arms

30e and 30f, the blade 30d, the blade 30c, the blade 30b, and the blade 30a are arranged in this order from the shutter base plate 10 toward the intermediate plate 40.

The rear blade arm 30e is rotatably attached to the shaft 11d of the shutter base plate 10, and the rear blade arm 30f is rotatably attached to the shaft 11c of the shutter base plate 10. The drive pin 31 of the rear blade drive member is inserted into the long hole 10b of the shutter base plate 10, and its tip is fitted into an engagement hole 30ee formed in the rear blade arm 30e.

The blades 20a to 20d and the blades 30a to 30d are formed to extend in a certain direction and have a pair of one side portions facing the traveling direction of the blade. One side part of the pair of one side parts of the blade 30d is in contact with a contact part 60a, which will be described later, at the traveling end position of the blade.

When the leading blade drive member is rotated clockwise against the urging force of the leading blade drive spring by the set member, the leading

blade arms

20e and 20f are rotated clockwise by the drive pin 21, and FIG. As shown in FIG. 4, the four blades 20a to 20d of the leading blade group 20 are deployed while reducing the mutual overlap, thereby closing the exposure opening 10a.

When the leading blade driving member is rotated counterclockwise by the biasing force of the leading blade driving spring by the set member, the leading

blade arms

20e and 20f are rotated counterclockwise by the driving pin 21, and FIG. As shown in FIG. 4, the four blades 20a to 20d of the leading blade group 20 are overlapped while increasing the mutual overlap to open the exposure opening 10a.

When the rear blade drive member is rotated clockwise against the urging force of the rear blade drive spring by the set member, the

rear blade arms

30e and 30f are rotated clockwise by the drive pin 31, FIG. As shown in FIG. 4, the four blades 30a to 30d of the rear blade group 30 are overlapped while increasing the mutual overlap to open the exposure opening 10a.

When the trailing blade driving member is rotated counterclockwise by the biasing force of the trailing blade driving spring by the set member, the trailing

blade arms

30e and 30f are rotated counterclockwise by the driving pin 31, and FIG. As shown in FIG. 4, the four blades 30a to 30d of the rear blade group 30 are expanded while reducing the mutual overlap to close the exposure opening 10a.

As shown in FIGS. 1 to 3, the buffer member 60 is a member that is fixed to the lower end portion of the shutter base plate 10 and alleviates the impact of the blades of the rear blade group 30 that has reached the travel end position. FIG. 5 shows an enlarged view of the buffer member 60. 5A is a front view of the buffer member 60, and FIG. 5B is a side view of the buffer member. The buffer member 60 includes a buffer member main body 61 that forms a skeleton of the buffer member 60, and a buffer auxiliary member 72 that is attached to the buffer member main body 61.

The buffer member main body 61 has a certain thickness, is formed in a rectangular shape, and is formed of an elastic material such as rubber or resin. The buffer member main body 61 has an abutting portion 61 a that abuts against one side portion of the blade 30 d when the rear blade group 30 travels. The contact portion 61a extends in parallel with the surface of the shutter base plate 10, and specifically includes a contact surface that is a flat surface that extends in the longitudinal direction of the rectangle and faces one side of the blade 30d.

The through-hole 62 penetrating in the direction perpendicular to the longitudinal direction of the contact portion 61a, that is, the thickness direction is formed in the buffer member body 61. The through hole 62 includes a first through hole 63, a second through hole 64, and a third through hole 65. These through holes extend along the direction in which the contact portion 61a extends and are arranged in parallel to each other.

The buffer member main body 61 includes a pair of fixing members 66 that are formed to face each other in the longitudinal direction. The buffer member main body 61 is fixed to the shutter base plate 10 by the fixing member 66. The fixing member 66 has a shape protruding from one surface of the buffer member main body 61. A hole 10d is formed in the shutter base plate 10 at a position corresponding to the fixing member 66, and the fixing member 66 is inserted into the hole 10d. The structure of the fixing member 66 and the hole 10d is shown in FIG. 4B. The outer periphery of the fixing member 66 and the inner periphery of the hole 10d have substantially the same shape, and the buffer member body 61 is fixed to the shutter base plate 10 by fitting the fixing member 66 into the hole 10d. The fixing member 66 may be fitted into the hole 10d, and an adhesive may be applied between the fixing member 66 and the hole 10d to securely fix the fixing member 66. Further, the shutter base plate 10 is provided with a protruding portion that protrudes from the plate surface of the shutter base plate 10, a hole is provided in the buffer member main body 61, and the protruding portion of the shutter base plate 10 is fitted into the hole of the buffer member main body 61, The member main body 61 may be attached to the shutter base plate 10. Further, the buffer member main body 61 may be attached to the shutter base plate 10 by inserting rivets, screws or the like into the holes of the buffer member main body 61. Further, a plate-like projecting portion projecting from the lower end portion of the shutter base plate 10 toward the front side may be provided, and the buffer member main body 61 may be attached to the surface of the projecting portion.

The buffering auxiliary member 72 is a member fitted in the through hole 62, and the buffering member main body 61 and the buffering auxiliary member 72 are formed of materials having different hardnesses. As an index indicating hardness, durometer hardness is used, and a numerical value of 0 to 100 is used. The numerical value indicated by this index indicates that it is harder as the numerical value is larger.

As shown in FIGS. 5A and 5B, the buffering auxiliary member 72 includes a first buffering auxiliary member 73, a second buffering auxiliary member 74, and a third buffering auxiliary member 75. The first buffering auxiliary member 73, the second buffering auxiliary member 74, and the third buffering auxiliary member 75 are each formed of an elastic material such as rubber or resin. The first buffering auxiliary member 73 is fitted into the first through-hole 63, the second buffering auxiliary member 74 is fitted into the second through-hole 64, and the third buffering auxiliary member 75 is fitted into the third through-hole 65, respectively. Combined.

There are various combinations of the hardness of the buffer member main body 61 and the hardness of the buffer auxiliary member 72 depending on the environment in which the focal plane shutter is used and the required durability. In the present embodiment, the case where the buffer member main body 61 and the buffer auxiliary member 72 are each formed of rubber will be described as an example. As a characteristic of the buffer member 60, it is required to reduce the impact of the blades while maintaining the durability of the buffer member 60. In the case where one buffer member is used, if the durability is emphasized, the hardness of the rubber becomes high and the ability to absorb the impact of the blades decreases. On the other hand, if the emphasis is placed on absorbing the impact of the blades, the hardness of the rubber becomes low, and there is a problem in durability. Further, when the hardness of the rubber is low under a high temperature environment, the buffer member 60 becomes soft due to heat, and there is a problem in durability. If the hardness of the rubber is high under a low temperature environment, the buffer member 60 becomes hard and it is difficult to absorb the impact. In the present embodiment, a combination of rubber used for the buffer member main body 61 and the buffer auxiliary member 72 in the buffer member 60 used in various environments will be described using specific examples.

As examples of rubber combinations, FIG. 6 shows an example of a combination considering impact and durability (hereinafter referred to as “Example 1”), and FIG. 7 shows an example of a combination for increasing durability (hereinafter referred to as “Example”). 2 ”) is shown in FIG. 8 as an example of a combination for reducing impact properties (hereinafter referred to as“ Example 3 ”), and in FIG. FIG. 10 shows an example of a combination for use in a low temperature environment (hereinafter referred to as “Example 5”).

In Example 1 shown in FIG. 6, the buffer member body 61 is made of rubber having a hardness of 60 degrees, the first buffer auxiliary member 73 is made of rubber having a hardness of 30 degrees, and the second buffer auxiliary member 74 is made of rubber having a hardness of 80 degrees. This is an example in which rubber is used as the third buffering auxiliary member 75 with a hardness of 30 degrees.

As the rubber used for the buffer member main body 61 with which the blade 30d directly collides, in order to ensure durability against impact, rubber having a hardness of 60 degrees is used and is located downstream of the buffer member main body 61 in the traveling direction of the blade. As the rubber used for the first buffering auxiliary member 73, rubber having a soft hardness of 30 degrees is used to absorb the impact. Further, the second buffering auxiliary member 74 located downstream of the first buffering auxiliary member 73 is again made of hard rubber having a hardness of 80 degrees, so that the durability is maintained. For the third buffering auxiliary member 75 on the downstream side of 74, a soft rubber having a hardness of 30 degrees is used again to absorb the impact.

By adopting such a combination of rubbers, the first buffering auxiliary member 73 and the third buffering auxiliary member 75 absorb the attack by the blades 30d step by step while maintaining the durability of the buffering member body 61. be able to.

In Example 2 shown in FIG. 7, the buffer member body 61 is made of rubber having a hardness of 80 degrees, the first buffer auxiliary member 73 is made of rubber having a hardness of 70 degrees, and the second buffer auxiliary member 74 is made of rubber having a hardness of 60 degrees. This is an example in which rubber is used as the third buffering auxiliary member 75 with a hardness of 50 degrees.

The rubber combination of Example 2 is a combination with emphasis on the durability of the buffer member 60. The shock-absorbing member main body 61 with which the blades 30d directly collide uses rubber having a hardness of 80 degrees in order to ensure durability against impact, and the first member located downstream of the shock-absorbing member main body 61 in the traveling direction of the blades. For the buffering auxiliary member 73 to the third buffering auxiliary member 75, rubber that gradually decreases in hardness to absorb the shock stepwise is used to absorb the shock.

By adopting such a combination of rubbers, it is possible to absorb an impact while maintaining the durability of the buffer member 60. Such a combination of rubbers is particularly effective for a focal plane shutter having a high blade traveling speed.

Example 3 shown in FIG. 8 is an example of a combination that is applied to a focal plane shutter in which the traveling speed of the blades is relatively slow and focuses on reducing the impact force. The buffer member body 61 is made of rubber having a hardness of 50 degrees, the first buffer auxiliary member 73 is made of rubber having a hardness of 40 degrees, the second buffer auxiliary member 74 is made of rubber having a hardness of 30 degrees, and the third buffer auxiliary member is made of rubber. The member 75 is an example in which rubber having a hardness of 20 degrees is used.

The shock-absorbing member main body 61 with which the blades 30d directly collide uses rubber having a relatively soft hardness of 50 degrees in order to ensure the durability against the low-speed blades, and is positioned downstream of the shock-absorbing member main body 61 in the blade traveling direction. For the first buffering auxiliary member 73, the second buffering auxiliary member 74, and the third buffering auxiliary member 75, soft rubber is used in stages to absorb the impact.

By adopting such a rubber combination, the first buffering auxiliary member 73 and the second buffering auxiliary member are maintained while maintaining the durability of the buffering member main body 61 against the blade 30d traveling at a relatively low speed. 74, the third buffering auxiliary member 75 can be provided with the buffering member 60 with an emphasis on greatly reducing impact by using soft rubber in stages in this order.

Example 4 shown in FIG. 9 is an example of the buffer member 60 used in a high-temperature environment. The buffer member main body 61 has a hardness of 70 degrees, and the first buffer auxiliary member 73 has a hardness of 60 degrees. This is an example in which rubber having a hardness of 50 degrees is used for the second buffering auxiliary member 74 and rubber having a hardness of 60 degrees is used for the third buffering auxiliary member 75.

In consideration of the fact that the hardness decreases in a high temperature environment, rubber having a high hardness of 70 degrees is used for the buffer member body 61 with which the blade 30d directly collides, and is downstream from the buffer member body 61 in the traveling direction of the blade. For the first buffering auxiliary member 73 and the second buffering auxiliary member 74 located on the side, soft rubber is used in this order, and the third buffering auxiliary member 75 is hard again to ensure durability. Rubber is used.

By adopting such a rubber combination, it is possible to mitigate the impact while maintaining the durability of the buffer member body 61 in a high temperature environment.

Example 5 shown in FIG. 10 is an example of the buffer member 60 used in a low temperature environment. The rubber of the buffer member main body 61 is a rubber having a hardness of 50 degrees, and the first buffer auxiliary member 73 is a hardness of 30 degrees. This is an example in which rubber having a hardness of 20 degrees is used for the second buffering auxiliary member 74 and rubber having a hardness of 30 degrees is used for the third buffering auxiliary member 75.

Considering the fact that the hardness of the buffer member body 61 directly colliding with the blade 30d is increased in a low temperature environment, a relatively soft rubber having a hardness of 50 degrees is used, and the downstream side of the blade member 61 in the traveling direction of the blade. Soft rubber is used in this order for the first buffering auxiliary member 73 and the second buffering auxiliary member 74 located in the position, and hard rubber is again applied to the third buffering auxiliary member 75 in order to absorb the impact. I use it.

By adopting such a combination of rubbers, it is possible to reduce the impact while maintaining the durability of the buffer member body 61 in a low temperature environment.

In this way, by changing the combination of rubber hardness used for each of the buffer member main body 61, the first buffer auxiliary member 73, the second buffer auxiliary member 74, and the third buffer auxiliary member 75, various Thus, it is possible to provide the buffer member 60 that can meet the demands of various elastic deformations. Further, since the buffer member main body 61 is interposed in the region between the plurality of buffer auxiliary members 72, the buffer member 60 that can meet various elastic deformation needs can be provided in consideration of the hardness of this region.

Next, the operation of the focal plane shutter 1 will be described with reference to FIGS. FIG. 1 shows an initial state before photographing, FIG. 2 shows a state in which the exposure operation of the leading blade group is finished, and FIG. 3 shows a state in which the exposure operation of the trailing blade group is finished.

FIG. 1 shows an initial state when the setting operation by the setting member is completed. The leading blade drive member is locked by the set member at the set position before the shutter operation. As shown in FIG. 1, the leading blade group 20 covers the exposure opening 10a in a developed state. The rear blade drive member is locked by the set member at the set position before the shutter operation. The rear blade group 30 is positioned above the exposure opening 10a in a superimposed state. The set member locks the leading blade drive member against the biasing force of the leading blade drive spring and locks the trailing blade drive member against the biasing force of the trailing blade drive spring.

When the release button is pressed, the leading blade electromagnet and the trailing blade electromagnet are energized, and the leading blade driving member and trailing blade driving member are attracted and held by the leading blade electromagnet and trailing blade electromagnet.

In a state where the leading blade driving member and the trailing blade driving member are attracted and held by the leading blade electromagnet and the trailing blade electromagnet, the set member is rotated in a predetermined direction by the biasing force of the biasing spring, and is moved from the set position. Return to the retracted position. As a result, although the engagement of the leading blade driving member and the trailing blade driving member is released, the state of being attracted and held by the leading blade electromagnet and the trailing blade electromagnet is maintained, so that it rotates counterclockwise. Is suppressed.

Next, when the energization of the leading blade electromagnet is stopped, the suppression of the counterclockwise rotation of the leading blade driving member is released, and the leading blade driving member rotates counterclockwise to drive pin 21. Is moved from the upper end to the lower end of the long hole 10c. Accordingly, the blades 20a to 20d are folded while moving downward to open the exposure opening 10a, thereby opening the exposure opening 10a. Specifically, the exposure opening 10a is opened at the upper end edge of the blade 20a which is a slit forming blade. The counterclockwise rotation of the leading blade driving member stops when the driving pin 21 of the leading blade driving member comes into contact with a buffer member provided at the lower end of the long hole 10c. Accordingly, the counterclockwise rotation of the leading blade arms 20a to 20d is stopped. By such movement of the leading blade group 20, as shown in FIG. 2, the exposure opening 10a is in an open state (exposure state).

When the energization of the rear blade electromagnet is stopped after a lapse of a predetermined time from the stop of energization of the leading blade electromagnet, the suppression of counterclockwise rotation of the trailing blade drive member is released, and the trailing blade drive member is Rotate counterclockwise to move the drive pin 31 from the upper end to the lower end of the long hole 10b. Accordingly, the blade arms 30a to 30d are deployed while moving downward so as to close the exposure opening 10a, and close the exposure opening 10a. Specifically, the exposure opening 10a is closed at the lower end portion of the blade 30d which is a slit forming blade. The counterclockwise rotation of the trailing blade driving member stops when the driving pin 31 comes into contact with a buffer member provided at the lower end of the long hole 10b. Accordingly, the counterclockwise rotation of the blades 30a to 30d is stopped. By such movement of the rear blade group 30, as shown in FIG. 3, the exposure opening 10a is in a closed state (end of exposure).

When the traveling of the rear blade group 30 is completed, the blade 30d of the rear blade group 30 contacts the contact portion 60a of the buffer member 60, and the shock is reduced by the buffer member 60. By selecting a combination of the hardness of the buffer member main body 61 and the buffer auxiliary member 72, it can be applied to various elastic deformations.

Next, in preparation for the next shooting, the set member performs a set operation of applying a driving force to each of the leading blade driving member and the trailing blade driving member. The set member rotates in a predetermined direction against the biasing force of the biasing spring by a driving force of a driving mechanism (not shown). As the set member rotates, the leading blade drive member rotates clockwise against the biasing force of the leading blade drive spring. Further, the rear blade driving member rotates clockwise against the urging force of the rear blade driving spring. By rotating the rear blade drive member, the rear blade group 30 is folded while moving upward to open the exposure opening 10a, and opens the exposure opening 10a. Further, by the rotation of the leading blade driving member, the leading blade group 20 expands while moving upward so as to cover the exposure opening 10a, and closes the exposure opening 10a.

When the set member is rotated by a predetermined angle by the drive mechanism, the rotation is stopped and held at the set position. Thus, the leading blade driving member and the trailing blade driving member are set at the set position before the shutter operation, and the driving force for causing the leading blade group 20 and the trailing blade group 30 to perform the shutter operation is charged. Then, the focal plane shutter 1 returns to the initial state shown in FIG.

According to the present embodiment, the buffer member main body 61 and the buffer auxiliary member 72 fitted in the through hole 62 are formed of members having different hardnesses. By setting the hardness of the buffer member main body 61 and the buffer auxiliary member 72 to a desired combination, the buffer member 60 suitable for the focal plane shutter used in various environments can be provided.

According to the present embodiment, the first buffering auxiliary member 73 fitted into the first through-hole 63, the second buffering auxiliary member 74 fitted into the second through-hole 64, and the third And a third buffering auxiliary member 75 fitted into the through hole 65 of the first buffering member. Then, by changing the combination of the hardness of the buffer member main body 61 and the first to third buffer auxiliary members 73 to 75, the buffer member 60 having various hardness characteristics can be provided. Therefore, it is possible to provide the buffer member 60 that can be finely adapted to the focal plane shutter used in various environments.

According to the present embodiment, the through hole 62 is formed so as to extend in the same direction as the direction in which the contact portion 61a extends, and the buffer auxiliary member 72 is fitted into the through hole 62. The received impact force can be evenly distributed, and damage to the blade 30d can be reduced.

According to the present embodiment, among the plurality of blades of the rear blade group 30, the slit forming blade 30d contacts the contact portion 61a, so that the impact by the slit forming blade 30d having a high blade traveling speed is effectively prevented. Can be relaxed.

In the above-described embodiment, the through hole 62 is configured by the first to third through holes 63 to 65, but the number of through holes is not limited to three. The number of through holes may be one, or four or more.

In the above-described embodiment, the shape of the through hole 62 has been described as a long hole, but is not limited to a long hole. It can be appropriately selected according to the specifications of the focal plane shutter used, such as a circle or an ellipse.

In the above-described embodiment, the hardnesses of the rubbers used for the first buffering auxiliary member 73, the second buffering auxiliary member 74, and the third buffering auxiliary member 75 are combined differently. As a combination of rubbers, the rubber used for any two buffering auxiliary members may be the same hardness as in Examples 1, 4 and 5, or all of them as in Examples 2 and 3. The cushioning auxiliary member may have a different rubber hardness. Further, all the buffer auxiliary members may have the same hardness.

In the above-described embodiment, the cushioning member main body 61, the first buffering auxiliary member 73, the second buffering auxiliary member 74, and the third buffering auxiliary member 75 have been described using rubber. However, in the present invention, The material used is not limited to rubber. Any elastic material may be used. For example, a resin may be used. When resin is used, all the materials of the buffer member main body 61, the first buffer auxiliary member 73, the second buffer auxiliary member 74, and the third buffer auxiliary member 75 may be used as resin, or rubber and resin. May be used in combination.

In the above-described embodiment, the buffering auxiliary member 72 has been described on the assumption that it is a solid buffering auxiliary member. However, when the buffering auxiliary member 72 is inserted into the through-hole 62, it may not be solid. For example, the buffer auxiliary member 72 may be inserted into the through hole 62 by filling the through hole 62 with the liquid buffer auxiliary member 72 and curing it.

In the above-described embodiment, the buffer member 60 that reduces the impact of the slit forming blade 30d of the rear blade group 30 including a plurality of blades has been described. However, the present invention provides a buffer member that cushions the impact of such blades. It is not limited. A buffer member may be attached to the travel end position of the leading blade group 20. The buffer member of the present invention can also be applied to a focal plane shutter having one leading blade and one trailing blade.

The present invention is capable of various embodiments and modifications without departing from the broad spirit and scope of the present invention. The above-described embodiments are for explaining the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

This application is based on Japanese Patent Application No. 2017-118474 filed on June 16, 2017. The specification, claims and entire drawings of Japanese Patent Application No. 2017-118474 are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 Focal plane shutter 10 Shutter base plate

10a Exposure opening

10b, 10c Long

hole 10d Hole

11a, 11b, 11c, 11d Shaft 20

Lead blade group

20a, 20b, 20c,

20d Blade

20e, 20f Lead blade arm 20ff Engagement hole 21 Drive pin 30

Rear blade group

30a, 30b, 30c,

30d Blade

30e, 30f Rear blade arm 30ee Engagement hole 31 Drive pin 40 Intermediate plate 40a Exposure opening 50 Cover plate 50a Exposure opening 60 Buffer member 61 Buffer member body 61a Contact portion 62 Through Hole 63 First through hole 64 Second through hole 65 Third through hole 66 Fixing member 72 Buffer auxiliary member 73 First buffer auxiliary member 74 Second buffer auxiliary member 75 Third buffer auxiliary member

Claims

A ground plate in which an exposure opening is formed;
A blade member comprising at least one blade for opening and closing the exposure opening;
A driving member connected to the blade member and driving the blade member so that the blade opens and closes the exposure opening;
The blades that have reached the travel end position, abutting on one side of the traveling direction side, provided with a contact portion extending in parallel with the surface of the base plate, and comprising a buffer member formed of an elastic material,
The buffer member is
A buffer member body having at least one through-hole penetrating in a direction perpendicular to a direction in which the contact portion extends;
A buffer auxiliary member that fits into the through-hole and is formed with a hardness different from that of the buffer member body,
Focal plane shutter.
The through hole extends in the same direction as the direction in which the contact portion extends.
The focal plane shutter according to claim 1.
The through hole includes a first through hole and a second through hole,
The buffering auxiliary member includes a first buffering auxiliary member that fits into the first through hole, and a second buffering auxiliary member that fits into the second through hole.
The focal plane shutter according to claim 1 or 2.
The hardness of the first buffering auxiliary member and the hardness of the second buffering auxiliary member are different.
The focal plane shutter according to claim 3.
The blade member includes a rear blade group including a plurality of blades,
Of the plurality of blades of the rear blade group, the slit forming blade contacts the contact portion.
The focal plane shutter according to any one of claims 1 to 4.
An imaging device comprising the focal plane shutter according to any one of claims 1 to 5.