JP2020101627A - Focal plane shutter and imaging apparatus - Google Patents

Abstract

To provide a configuration capable of performing travelling not only in one direction, but also in both directions with respect to an opening in a balanced manner, in a focal plane shutter.SOLUTION: The focal plane shutter includes a base plate (1) which has the opening, two first arms (41 and 42) which are attached to the base plate, a first blade (2) which is attached to the first arms and reciprocally travels, so as to open/close the opening, a first energizing member (41b) which energizes one of the first arms in one travelling direction, and a second energizing member (42b) which energizes the other of the first arms in the other travelling direction.SELECTED DRAWING: Figure 1

Description

One embodiment of the present invention relates to a focal plane shutter used for an imaging device such as a camera.

In some focal plane shutters, sectors (blades) open and close an aperture (opening) to expose an image sensor. In such a focal plane shutter, a sector urging spring may be provided that acts to push back a gap (play) generated in the drive transmission means and the sector unit or the connecting portion between the sector unit arm and the sector to one side. is there. Patent Document 1 discloses a sector drive device having a sector urging spring 16 that engages with and urges the first sector arm 13.

JP, 2004-317663, A

Although the conventional configuration including the configuration described in Patent Document 1 can deal with only when the blade travels in one direction with respect to the opening, it does not work when the blade travels in the opposite direction with respect to the opening. There were enough cases. That is, the urging force of the spring during traveling of the blade may differ between traveling in one direction and traveling in the opposite direction, and the load of the drive source may differ in one direction and in the opposite direction. It was

The present invention adopts the following means in order to solve the above problems. In the following description, reference numerals and the like in the drawings are added in parentheses in order to facilitate understanding of the invention, but each constituent element of the present invention is not limited to these additions. It should be broadly interpreted to the extent that a person can technically understand it.

The first means of the present invention is
A main plate (1) having an opening,
Two first arms (41, 42) attached to the main plate,
A first blade (2) attached to the first arm to open and close the opening by reciprocating;
A first urging member (41b) for urging one of the first arms in one traveling direction;
A second urging member (42b) for urging the other of the first arms in the other traveling direction;
With
It is a focal plane shutter.

According to the focal plane shutter having the above-described configuration, the two arms of the first blade are provided with the biasing members that apply biasing forces in directions opposite to the traveling direction of the first blade. Therefore, when the blade travels in one direction and the opposite direction with respect to the opening, the blade can be rattled with an appropriate biasing force. Further, when the blade travels in one direction and the other direction, it is possible to adjust the biasing force applied to the blade by the biasing member to an appropriate balance. can do. Further, by adjusting the urging force of each urging member, it is possible to change the traveling speed when the blade travels in one direction and when traveling in the opposite direction.

In the above focal plane shutter, preferably,
The biasing force of the first biasing member (41b) and the biasing force of the second biasing member (42b) are substantially the same at a substantially intermediate position in the region where the first blade (2) travels.

According to the focal plane shutter having the above-described configuration, it is possible to perform the backlash with substantially the same strength when the first blade travels in one direction and in the opposite direction. As a result, the first blade can travel in a well-balanced manner in the one direction and the opposite direction.

In the above focal plane shutter, preferably,
At least one arm portion of at least one of the first biasing member (41b) and the second biasing member (42b) is hooked at one end to an eccentric pin (54) arranged on the base plate.

According to the focal plane shutter having the above structure, the eccentric pin is rotated by providing the same structure as the eccentric pin (54) near the first urging member (41b) or the second urging member (42b). The biasing force applied by the biasing member can be adjusted relatively easily.

In the above focal plane shutter, preferably,
Two second arms (51, 52) attached to the main plate,
A second blade (3) attached to the second arm to open and close the opening of the main plate by reciprocating;
A third urging member (51b) for urging one of the second arms in one traveling direction,
A fourth urging member (52b) for urging the other arm of the second arm in the other traveling direction.

According to the focal plane shutter having the above-described configuration, the two arms of the second blade are provided with the biasing members that apply biasing forces in directions opposite to the traveling direction of the second blade. Therefore, when the blade travels in one direction and the opposite direction with respect to the opening, the blade can be rattled with an appropriate biasing force. Further, when the blade travels in one direction and the other direction, it is possible to adjust the biasing force applied to the blade by the biasing member to an appropriate balance. can do. Further, by adjusting the urging force of each urging member, it is possible to change the traveling speed when the blade travels in one direction and when traveling in the opposite direction.

In the above focal plane shutter, preferably,
The biasing force of the third biasing member (51b) and the biasing force of the fourth biasing member (52b) are substantially the same at a substantially intermediate position of the region where the second blade (3) travels.

According to the focal plane shutter having the above-described configuration, it is possible to perform the backlash with substantially the same strength when the second blade travels in one direction and in the opposite direction. As a result, the first blade can travel in a well-balanced manner in the one direction and the opposite direction.

In the above focal plane shutter, preferably,
At least one arm of at least one of the third urging member (51b) and the fourth urging member (52b) is hooked at one end to an eccentric pin (54) arranged on the main plate.

According to the focal plane shutter having the above configuration, the biasing force applied by the biasing member can be adjusted relatively easily by rotating the eccentric pin.

In the above focal plane shutter, preferably,
At least one of the first blade (2) and the second blade (3) is driven by an electromagnetic actuator (61, 62) arranged on the main plate.

According to the focal plane shutter having the above configuration, in a configuration in which at least one of the first blade and the second blade is driven by the electromagnetic actuator, the biasing force applied to the first blade and the second blade by the biasing member is appropriate. It can be a good balance.

In the above focal plane shutter, preferably,
At least one of the first blade (2) and the second blade (3) is driven by a spring of a drive mechanism (6) arranged on the main plate.

According to the focal plane shutter having the above configuration, in the configuration in which at least one of the first blade and the second blade is driven by the spring, the biasing force applied to the first blade and the second blade by the biasing member is appropriate. Can be balanced.

Any one of the focal plane shutters described above is preferably applied to an image pickup device such as a camera.

According to the image pickup apparatus as described above, since the focal plane shutter is configured to be capable of traveling at a stable speed not only in one direction but also in two directions with respect to the opening, high-speed continuous shooting is possible. It can be used as a device.

FIG. 1 is a plan view of the auxiliary ground plate side with the auxiliary ground plate and the intermediate plate removed, with the first blade retracting from the opening and the second blade covering the opening. FIG. FIG. 2 is an enlarged view of the state shown in FIG. FIG. 3 is a plan view as seen from the side of the auxiliary base plate with the auxiliary base plate and the intermediate plate removed, and the focal point during exposure operation in which imaging is performed by the slit formed by the first blade and the second blade. It is a top view of a plain shutter. FIG. 4 is an enlarged view of the state shown in FIG. FIG. 5 is a plan view from the side of the auxiliary ground plate with the auxiliary ground plate and the intermediate plate removed, showing a plan view of the focal plane shutter with the first blade covering the opening and the second blade retracting from the opening. It is a figure. FIG. 6 is an enlarged view of the state shown in FIG. FIG. 7 is a plan view seen from the side opposite to FIGS. 1 to 6, and is a plan view of the focal plane shutter showing the drive mechanism in a state where the opening is opened. FIG. 8 is an enlarged view around the eccentric pin of the focal plane shutter. FIG. 9 is an enlarged view of a state in which the eccentric pin shown in FIG. 8 is rotated. FIG. 10 is an enlarged cross-sectional view of the eccentric pin of the focal plane shutter.

In the focal plane shutter of the present invention, in a configuration in which the blade is reciprocally driven in one direction and the opposite direction with respect to the opening, each of the two arms connected to the blade is biased in one direction and the opposite direction. One of the features is that it is provided with a biasing member.

Embodiments according to the present invention will be specifically described with reference to the drawings according to the following configurations. However, the embodiments described below are merely examples of the present invention, and do not limit the technical scope of the present invention. In addition, in each drawing, the same components are denoted by the same reference numerals, and the description thereof may be omitted.
1. Embodiment 2. Features of the present invention 3. Supplementary information

<1. Embodiment>
In the focal-plane shutter of the present embodiment, the first blade and the second blade are driven by the drive mechanism in one direction and the opposite direction with respect to the opening portion while traveling to expose the image sensor, and thus the first blade is When the leading blade (or the leading curtain) becomes the second blade or the trailing blade (or the trailing curtain), and when the second blade becomes the leading blade (or the leading curtain) and the first blade becomes the trailing blade (or the trailing curtain). There is.

1 to 6 are plan views of the focal plane shutter of this embodiment. FIG. 1 is a plan view of the auxiliary ground plate side with the auxiliary ground plate and the intermediate plate removed, with the first blade retracting from the opening and the second blade covering the opening. FIG. FIG. 2 is an enlarged view of the state shown in FIG. FIG. 3 is a plan view as seen from the side of the auxiliary base plate with the auxiliary base plate and the intermediate plate removed, and the focal point during exposure operation in which imaging is performed by the slit formed by the first blade and the second blade. It is a top view of a plain shutter. FIG. 4 is an enlarged view of the state shown in FIG. FIG. 5 is a plan view from the side of the auxiliary ground plate with the auxiliary ground plate and the intermediate plate removed, showing a plan view of the focal plane shutter with the first blade covering the opening and the second blade retracting from the opening. It is a figure. FIG. 6 is an enlarged view of a state where the opening shown in FIG. 5 is opened. FIG. 7 is a plan view seen from the opposite side of FIGS. 1 to 6, and is a plan view of the focal plane shutter showing the drive mechanism in a state where the opening is opened.

As shown in the drawing, the focal plane shutter of the present embodiment includes a base plate 1, a first blade 2, a second blade 3, a first blade main arm 41, a first blade sub arm 42, and a second blade main arm. 51 and a secondary arm 52 for the second blade. Further, the focal plane shutter of the present embodiment includes the first blade drive pin 43, the first blade bias spring 41b, the first blade bias spring 42b, the second blade drive pin 53, and the second blade bias pin. It includes a biasing spring 51b and a second blade biasing spring 52b. Further, the focal plane shutter of this embodiment includes a first electromagnetic actuator 61, a second electromagnetic actuator 62, and a rotation stop 56 for the eccentric pin 54, as shown in FIG. 7. In the present specification, the first blade and the second blade may be collectively referred to as “blades”. Further, the first blade main arm 41 and the first blade sub arm 42 may be collectively referred to as a “first blade arm”. The second blade main arm 51 and the second blade sub arm 52 may be collectively referred to as a "second blade arm". In addition, the arm for the first blade and the arm for the second blade may be collectively referred to as “arm”. Further, the configuration for driving the blade via the arm may be collectively referred to as a "driving mechanism".

<ground plate 1>
The base plate 1 is a substrate portion of the focal plane shutter and has a substantially rectangular opening 1a. The opening 1a may have any shape other than a rectangle. As shown in FIG. 7, a drive mechanism 6 that drives the first blade 2 and the second blade 3 is mounted on the side of the opening 1 a of the main plate 1 (on the right side of the drawing). Therefore, the drive mechanism 6 in FIGS. 1 to 6 is mounted on the rear surface side on the left side of the drawings.

As shown in FIGS. 1 to 6, shafts 41a, 42a, 51a and 52a are erected in a blade chamber of the main plate 1 described later. The first blade main arm 41 is connected to the shaft 41a. The shaft 41a serves as a central axis of rotation of the first blade main arm 41. A first blade biasing spring 41b is arranged on the shaft 41a. The first blade secondary arm 42 is connected to the shaft 42a. The shaft 42a serves as a central axis of rotation of the first blade slave arm 42. A first blade biasing spring 42b is arranged on the shaft 42a. The second blade main arm 51 is connected to the shaft 51a. The shaft 51a serves as a central axis of rotation of the second blade main arm 51. A second blade biasing spring 51b is arranged on the shaft 51a. The second blade slave arm 52 is connected to the shaft 52a. The shaft 52a serves as the central axis of rotation of the second blade slave arm 52. A second blade biasing spring 52b is arranged on the shaft 52a.

Shafts 44, 45, and 55 and an eccentric pin 54 are erected in a blade chamber of the main plate 1 which will be described later. The first arm portion 41b1 of the first blade biasing spring 41b is hooked on the shaft 44. The shaft 44 fixes the position of the first arm portion 41b1 of the first blade biasing spring 41b. The first arm portion 42b1 of the first blade biasing spring 42b is hooked on the shaft 45. The shaft 45 fixes the position of the first arm portion 42b1 of the first blade biasing spring 42b. The first arm portion 52b1 of the second blade biasing spring 52b is hooked on the shaft 55. The shaft 55 fixes the position of the first arm portion 52b1 of the second blade biasing spring 52b. The first arm portion 51b1 of the second blade biasing spring 51b is hooked on the eccentric pin 54. The eccentric pin 54 adjustably fixes the position of the first arm portion 51b1 of the second blade biasing spring 51b.

The base plate 1 is formed with an elongated hole-shaped through hole 11 that extends in an arc shape around a shaft 41a and an elongated hole-shaped through hole 12 that extends in an arc shape around a shaft 51a. The first blade drive pin 43 is inserted into the through hole 11. The second blade drive pin 53 is inserted into the through hole 12.
The first blade drive pin 43 and the second blade drive pin 53 are one member constituting the drive mechanism 6.

An image sensor (not shown) is arranged at a position opposite to the subject side of the opening 1a of the main plate 1. The image pickup device is an image sensor such as a CCD or a CMOS, and is a photoelectric conversion device that converts the emitted light into an electric signal. The image pickup element may be arranged on the side of the main plate 1 or may be arranged on the side of the auxiliary main plate (not shown) depending on the layout in the camera.

<Auxiliary ground plate, intermediate plate>
The focal plane shutter of the present embodiment has an auxiliary base plate and an intermediate plate (not shown) because they are well known. The auxiliary ground plate has an opening at a position facing the opening 1a of the ground plate 1, and is arranged so as to face the ground plate 1 with a predetermined gap from the ground plate 1. The intermediate plate has an opening at a position facing the opening 1a of the main plate 1, and is arranged between the main plate 1 and the auxiliary main plate with a predetermined space between the main plate 1 and the auxiliary main plate. .. A blade chamber in which the first blade and the second blade are arranged is formed between the base plate 1 and the intermediate plate and between the auxiliary base plate and the intermediate plate, respectively.

<Second blade 3>
The second blade 3 is composed of a plurality of plate-shaped blade members 31 to 34. As is well known, the second blade 3 is connected to the second blade main arm 51 and the second blade sub arm 52 by using a plurality of rivets 51d and 52d as a connecting tool. The second blade 3 is arranged in the blade chamber as described above. The second blade 3 is driven by the second blade drive pin 53 via the second blade main arm 51 to cover the exposure opening formed by the opening 1a and open it (open/closed state). Switch. The blade members 31 to 34 forming the second blade 3 are each made of a material such as metal such as aluminum, carbon fiber, or resin, but are not limited to these materials.

<First blade 2>
The first blade 2 is composed of a plurality of plate-shaped blade members 21-24. As is well known, the first blade 2 is connected to the first blade main arm 41 and the first blade sub arm 42 by a connecting tool similar to the plurality of rivets 51d and 52d. The first blade 2 is arranged in the blade chamber as described above. The first blade 2 is driven by the first blade drive pin 43 via the first blade main arm 41 to cover the exposure opening formed by the opening 1a and the open state (opening/closing state). Switch. The blade members 21 to 24 forming the first blade 2 are each formed of a material such as a metal such as aluminum, carbon fiber, or a resin, but are not limited to these materials.

When an image is captured by exposure of the image sensor, the first blade 2 and the second blade 3 run toward the upper side and the lower side with respect to the opening 1a shown in FIGS. At this time, the image pickup device receives and images the light that has passed through the slit formed by the first blade 2 and the second blade 3. When the first blade 2 and the second blade 3 travel upward with respect to the opening 1a, the states change in the order of FIG. 1, FIG. 3, and FIG. In this case, the second blade 3 is the leading blade (first curtain) and the first blade 2 is the trailing blade (second curtain). On the other hand, when the first blade 2 and the second blade 3 travel downward with respect to the opening 1a, the state changes in the order of FIG. 5, FIG. 3, and FIG. In this case, the first blade 2 is the leading blade (first curtain) and the second blade 3 is the trailing blade (second curtain).

<Main arm 41 for the first blade>
The first blade main arm 41 is connected to the first blade drive pin 43 and the first blade 2 of the drive mechanism. The first blade main arm 41 is rotatably connected to the shaft 41a of the main plate 1 and rotates about the shaft 41a. A connection hole into which the first blade drive pin 43 is inserted is formed in the first blade main arm 41. The first blade main arm 41 transmits the driving force generated by the operation of the first electromagnetic actuator 61 to the first blade 2 via the first blade drive pin 43. The first blade main arm 41 has a through hole 41c to which the second arm portion 41b2 of the first blade biasing spring 41b is hooked.

<First blade secondary arm 42>
The first blade secondary arm 42 is connected to the first blade 2. The first blade secondary arm 42 is rotatably connected to the shaft 42a of the main plate 1 and rotates about the shaft 42a. A driving force is not directly applied to the first blade slave arm 42, and the first blade slave arm 42 operates the first blade master arm 41 via the blade members 21 to 24 of the first blade 2. It works together. The first blade slave arm 42 has a through hole 42c into which the second arm portion 42b2 of the first blade biasing spring 42b is hooked.

<Second blade main arm 51>
The second blade main arm 51 is connected to the second blade drive pin 53 and the second blade 3. The second blade main arm 51 is rotatably connected to the shaft 51a of the main plate 1 and rotates about the shaft 51a. The second blade main arm 51 is formed with a connection hole into which the second blade drive pin 53 is inserted. The second blade main arm 51 transmits the driving force generated by the operation of the second electromagnetic actuator 62 to the second blade 3 via the second blade drive pin 53. The second blade main arm 51 has a through hole 51c to which the second arm portion 51b2 of the second blade biasing spring 51b is hooked.

<Second blade secondary arm 52>
The second blade slave arm 52 is connected to the second blade 3. The second blade slave arm 52 is rotatably connected to the shaft 52a of the main plate 1 and rotates about the shaft 52a. No driving force is directly applied to the second blade slave arm 52, and the second blade slave arm 52 operates to operate the second blade master arm 51 via the blade members 31 to 34 of the second blade 3. It works together. The second blade slave arm 52 has a through hole 52c to which the second arm portion 52b2 of the second blade biasing spring 52b is hooked.

<First blade drive pin 43>
The first blade drive pin 43 is connected to the first blade main arm 41 and inserted into the through hole 11. The first blade drive pin 43 is driven by the first electromagnetic actuator 61 and moves in an arc shape in the area of the through hole 11 around the shaft 41a.

<Second blade drive pin 53>
The second blade drive pin 53 is connected to the second blade main arm 51 and inserted into the through hole 12. The second blade drive pin 53 is driven by the second electromagnetic actuator 62 and moves in a circular arc shape in the region of the through hole 12 about the shaft 51a.

<First electromagnetic actuator 61>
The first electromagnetic actuator 61 includes a permanent magnet, a coil, and a yoke. When the coil is excited by energization, a magnetic pole is generated in the yoke, and a magnetic force is generated between the magnetic pole of the yoke and the magnetic pole made of a permanent magnet that is the rotor. The rotor of the first electromagnetic actuator 61 is connected to the first blade drive pin 43 and drives the first blade 2.

<Second electromagnetic actuator 62>
The second electromagnetic actuator 62 includes a permanent magnet, a coil, and a yoke. When the coil is excited by energization, a magnetic pole is generated in the yoke, and a magnetic force is generated between the magnetic pole of the yoke and the magnetic pole made of a permanent magnet that is the rotor. The rotor of the second electromagnetic actuator 62 is connected to the second blade drive pin 53 and drives the second blade 3.

<Biasing spring 41b for the first blade>
The first blade biasing spring 41b is a torsion coil spring and has a first arm portion 41b1, a second arm portion 41b2, and a coil portion 41b3. The coil portion 41b3 is arranged around the shaft 41a. The first arm portion 41b1 is hooked on the shaft 44 of the main plate 1. The second arm portion 41b2 is hooked on the through hole 41c of the first blade main arm 41. Since the shaft 44 is a fixed shaft on the base plate 1, the first blade biasing spring 41b applies a clockwise biasing force to the first blade main arm 41 by the second arm portion 41b2. The first blade 2 is loosened by the biasing force applied from the first blade biasing spring 41b. The first blade biasing spring 41b is a specific example of the "first biasing member" of the present invention.

<Biasing spring 42b for the first blade>
The first blade biasing spring 42b is a torsion coil spring and has a first arm portion 42b1, a second arm portion 42b2, and a coil portion 42b3. The coil part 42b3 is arranged around the shaft 42a. The first arm portion 42b1 is hooked on the shaft 45 of the main plate 1. The second arm portion 42b2 is hooked on the through hole 42c of the first blade slave arm 42. Since the shaft 45 is a fixed shaft on the main plate 1, the first blade biasing spring 42b applies a counterclockwise biasing force to the first blade slave arm 42 by the second arm portion 42b2. The first blade 2 is loosened by the biasing force applied from the first blade biasing spring 42b. The first blade biasing spring 42b is a specific example of the "second biasing member" of the present invention.

<Biasing spring 51b for the second blade>
The second blade biasing spring 51b is a torsion coil spring and has a first arm portion 51b1, a second arm portion 51b2, and a coil portion 51b3. The coil portion 51b3 is arranged around the shaft 51a. The first arm portion 51b1 is hooked on the eccentric pin 54 of the main plate 1. The second arm portion 51b2 is hooked on the through hole 51c of the second blade main arm 51. The eccentric pin 54 functions as a fixed shaft on the main plate 1 during operation of the focal plane shutter, and the second blade biasing spring 51b is counterclockwise with respect to the second blade main arm 51 by the second arm portion 51b2. Provides a biasing force in the rotating direction. The second blade 3 is loosened by the biasing force applied from the second blade biasing spring 51b. The second blade biasing spring 51b is a specific example of the "third biasing member" of the present invention.

<Eccentric pin 54>
8 and 9 are enlarged views of the periphery of the eccentric pin 54. The rotation state of the eccentric pin 54 is different between FIG. 8 and FIG. 9. FIG. 10 is a sectional view of the eccentric pin 54.

The eccentric pin 54 has a rotating shaft 54a, an adjusting shaft 54b, a head portion 54c, a head hole 54d, and a caulking portion 54e. A head hole 54d is formed in the head 54c. The head hole 54d has a shape into which a minus driver can be inserted, and is used when the eccentric pin 54 rotates. The caulking portion 54e is located on the opposite side to the head portion 54c, and the eccentric pin 54 is rotatably connected to the main plate 1 at the portion. The caulking portion 54e further connects the main plate 1 and the rotation stopper 56.

The rotary shaft 54a penetrates the main plate 1, and the eccentric pin 54 rotates with the rotary shaft 54a as a reference. The adjustment shaft 54b is a shaft portion having a center different from that of the rotation shaft 54a. When the eccentric pin 54 rotates, the adjustment shaft 54b rotates, but the position of the adjustment shaft 54b on the outer side in the circumferential direction changes. The adjustment shaft 54b is in contact with the first arm portion 51b1 of the second blade biasing spring 51b (see FIG. 10), and when the eccentric pin 54 rotates, the position of the first arm portion 51b1 changes ( (See FIGS. 8 and 9). When the position of the first arm portion 51b1 changes, the angle between the first arm portion 51b1 and the second arm portion 51b2 changes, and the second blade bias spring 51b moves from the second arm portion 51b2 to the second blade portion 51b2. The biasing force applied to the main arm 51 changes. The eccentric pin 54 is used to adjust the urging force applied from the second blade urging spring 51b. For example, the biasing force applied from the first blade biasing spring 41b to the first blade main arm 41 and the biasing force applied from the second blade biasing spring 51b to the second blade main arm 51. The rotational position of the eccentric pin 54 is adjusted at the time of shipment from the factory in order to achieve the balance with and substantially the same.

The eccentric pin 54 is in contact with a rotation stop 56 arranged on the main plate 1, and the rotation is restricted by the rotation stop 56 (see FIGS. 7 and 10). The rotation stopper 56 has a plurality of plate-shaped members extending in the circumferential direction. Each of these plate-shaped members is a leaf spring. The tip portion of the plate member is engaged with the groove formed in the base plate 1. The rotation stopper 56 rotates with the rotation of the eccentric pin 54, and is fixed at a plurality of predetermined positions in the circumferential direction in which the tip end portion of the plate member and the groove engage with each other. In order to release the engagement between the front end portion of the plate member and the groove and rotate the plate member to the next position, it is necessary to apply a certain force to the front end portion over the groove. The rotation stop 56 is an example of the configuration of the "rotation stop member" of the present invention.

As the rotation stopping member that restricts the rotation of the eccentric pin 54, a leaf spring member that restricts the rotation of the eccentric pin 54 by causing friction between the base plate 1 and the eccentric pin 54 may be used. Alternatively, other members may be used. The position of the eccentric pin 54 may be fixed by an adhesive.

<Biasing spring 52b for second blade>
The first blade biasing spring 52b is a torsion coil spring and has a first arm portion 52b1, a second arm portion 52b2, and a coil portion 52b3. The coil portion 52b3 is arranged centering on the shaft 52a. The first arm portion 52b1 is hooked on the shaft 55 of the main plate 1. The second arm portion 52b2 is hooked on the through hole 52c of the second blade slave arm 52. Since the shaft 55 is a fixed shaft on the main plate 1, the second blade biasing spring 52b applies a clockwise biasing force to the second blade slave arm 52 by the second arm portion 52b2. The second blade 3 is loosened by the biasing force applied from the second blade biasing spring 52b. The second blade biasing spring 52b is a specific example of the "fourth biasing member" of the present invention.

The urging force applied to the first blade 2 by the first blade urging spring 41b via the first blade main arm 41 in the state where the first blade 2 opens the opening 1a is the first blade 2 having the opening 1a. In the closed state, the first blade biasing spring 42b has substantially the same strength as the biasing force applied to the first blade 2 via the first blade slave arm 42. Further, in the state where the second blade 3 opens the opening 1a, the biasing force applied to the second blade 3 by the second blade biasing spring 51b via the second blade main arm 51 causes the second blade 3 to open. The second blade biasing spring 52b has substantially the same strength as the biasing force applied to the second blade 3 via the second blade slave arm 52 when the portion 1a is closed.

Further, the urging force applied to the first blade 2 by the first blade urging spring 41b via the first blade main arm 41 when the first blade 2 opens the opening 1a causes the second blade 3 to open. The second blade biasing spring 51b has substantially the same strength as the biasing force applied to the second blade 3 via the second blade main arm 51 when the portion 1a is opened. Further, when the first blade 2 closes the opening 1a, the biasing force applied to the first blade 2 by the first blade biasing spring 42b via the first blade slave arm 42 causes the second blade 3 to open. The second blade biasing spring 52b has substantially the same strength as the biasing force applied to the second blade 3 via the second blade slave arm 52 when the portion 1a is closed.

Further, in the region where the first blade 2 travels when opening and closing the opening 1a, the biasing force of the first blade biasing member 41b and the first blade biasing member 42b is approximately at an intermediate position of the running region. Is the same. Further, in the region where the second blade 3 travels when opening and closing the opening 1a, the biasing force of the second blade biasing member 51b and the second blade biasing member 52b is approximately at the intermediate position of the running region. Is the same.

The opening amount (angle) between the first arm portion 41b1 and the second arm portion 41b2 of the first blade biasing spring 41b in the state where the first blade 2 opens the opening portion 1a, the second blade 3 is opened. The opening amount (angle) between the first arm portion 51b1 and the second arm portion 51b2 of the second blade biasing spring 51b when the portion 1a is opened is substantially the same. In addition, the opening amount (angle) between the first arm portion 42b1 and the second arm portion 42b2 of the first blade biasing spring 42b in the state where the first blade 2 closes the opening 1a is the second blade 3 Is substantially the same as the opening amount (angle) between the first arm portion 52b1 and the second arm portion 52b2 of the second blade biasing spring 52b in the state where the opening portion 1a is closed.

As described above, the first blade biasing spring 42b and the second blade biasing spring 52b bias the blades in the direction of closing the opening 1a, and the first blade biasing spring 41b and the second blade The blade biasing spring 51b biases each blade in a direction to open the opening 1a. However, the biasing direction is reversed, and the first blade biasing spring 42b and the second blade biasing spring 52b are You may make it urge|bias each blade in the direction which opens an opening, and the 1st blade urging|biasing spring 41b and the spring 51b for 2nd blade urge|bias each blade in the direction which closes an opening.

<2. Features of this embodiment>
The focal-plane shutter of the above embodiment has the following features by adopting the above-mentioned configuration. Each configuration of the embodiments described below is merely an example of the configuration of the present invention, and the present invention is not limited to these specific configurations.

The focal plane shutter of the present embodiment has a structure in which first blade biasing springs 41b and 42b for biasing the first blade main arm 41 and the first blade slave arm 42 in opposite directions are locked. I am trying. Due to this configuration, the biasing force is applied by the respective biasing members in the opening direction and the closing direction of the first blade 2. Therefore, when the blade travels in one direction (for example, the upper side) and in the opposite direction (for example, the lower side) with respect to the opening 1a, the first blade 2 can be rattled with an appropriate biasing force. Further, when the blade travels in one direction and the other direction, it is possible to adjust the biasing force applied to the blade by the biasing member to an appropriate balance. can do.

In the focal plane shutter of the present embodiment, the first blade biasing spring 41b and the first blade biasing spring 41b are disposed at a substantially intermediate position between the position where the first blade 2 opens and the position where the opening 1a is closed. The urging forces of the springs 42b are configured to be substantially the same. As a result, the focal plane shutter of the present invention can be configured to allow the first blade to travel in a well-balanced manner when traveling in one direction and the opposite direction.

In the focal plane shutter of the present embodiment, the first arm portion 51b1 of the second blade biasing spring 51b is hooked on the eccentric pin 54, but the first blade biasing spring 41b has the first arm portion 51b1. An eccentric pin that fixes at least one position of the arm portion 41b1 and the first arm portion 42b1 of the first blade biasing spring 42b may be arranged. Thus, when the eccentric pin is arranged on the biasing spring, the position of one end of the biasing spring can be easily adjusted, and the biasing force of the biasing spring can be adjusted.

Further, the focal plane shutter of the present embodiment includes, in addition to the first blade 2, a second blade 3, a second blade main arm 51, and a second blade slave arm 52, and further, a second blade main arm. The second blade biasing springs 51b and 52b for biasing the arm 51 and the second blade slave arm 52 in opposite directions are locked to each other. Due to this configuration, the biasing force is applied to each of the opening direction and the closing direction of the second blade 3 by the respective biasing members. Therefore, when the blade travels in one direction (for example, the upper side) and in the opposite direction (for example, the lower side) with respect to the opening 1a, the second blade 3 can be rattled with an appropriate biasing force. In addition, since it is possible to adjust the urging force applied to the blade from the urging member when the blade travels in one direction and in the opposite direction, it is possible to stably and stably travel the blade in both directions. can do.

In the focal plane shutter of the present embodiment, the second blade biasing spring 51b and the second blade biasing spring are provided at a substantially intermediate position between the position where the second blade 3 opens and the position where the opening 1a is closed. The biasing force of the spring 52b is configured to be substantially the same. As a result, the focal plane shutter of the present invention can be configured to allow the first blade to travel in a well-balanced manner when traveling in one direction and the opposite direction.

Further, the focal plane shutter of the present embodiment is configured such that the first arm portion 51b1 of the second blade biasing spring 51b is hooked on the eccentric pin 54. However, an eccentric pin that fixes at least one position of the first arm portion 51b1 of the second blade bias spring 51b and the first arm portion 52b1 of the second blade bias spring 52b may be arranged. Thus, when the eccentric pin is arranged on the biasing spring, the position of one end of the biasing spring can be easily adjusted, and the biasing force of the biasing spring can be adjusted.

Further, the focal plane shutter of the present embodiment is configured such that the first blade 2 is driven by the first electromagnetic actuator 61 and the second blade 3 is driven by the second electromagnetic actuator 62. However, even in the configuration in which at least one of the first blade 2 and the second blade 3 is driven by the electromagnetic actuator, the biasing force applied to the first blade 2 and the second blade 3 by the biasing member has an appropriate balance. be able to.

Further, the focal plane shutter of the present embodiment is configured such that the first blade 2 is driven by the first electromagnetic actuator 61 and the second blade 3 is driven by the second electromagnetic actuator 62. However, a configuration in which at least one of the first blade 2 and the second blade 3 is driven by a spring may be adopted. As described above, even in the structure driven by the spring, the urging force applied to the first blade 2 and the second blade 3 by the urging member can be properly balanced.

Further, the image pickup apparatus using the focal-plane shutter of the present embodiment has a focal-plane shutter capable of traveling at a stable speed not only in one direction but in two directions with respect to the opening 1a, The structure enables high-speed continuous shooting.

<3. Supplementary items>
Heretofore, a specific description has been given of the embodiment of the present invention. The above description is merely a specific example, and the scope of the present invention is not limited to this embodiment, and is broadly construed to a range that a person skilled in the art can understand.

For example, in the embodiment, the configuration in which the first blade 2 and the second blade 3 each include four blade members has been described, but the number of blade members forming each blade can be arbitrarily changed.

Further, in the embodiment, the biasing springs 41b, 42b, 51b, and 52b, which are torsion springs (torsion coil springs), are illustrated as an example of the biasing member, but a leaf spring, a compression coil spring, or a tension coil, or Combinations of these springs may be used.

Further, in the embodiment, the configuration including the two blades of the first blade 2 and the second blade 3 has been described, but a configuration including only one blade may be adopted. In this case, it is mounted on a camera that employs an electronic front curtain, in which the front curtain (front blade) is artificially realized by controlling the image sensor and the image is completed by traveling of the rear curtain (rear blade). However, even in this case, the vehicle travels in one direction for imaging, and then travels in the opposite direction to obtain the set state before shooting. Therefore, when the blades travel in the one direction and the opposite direction, the first blade 2 or the second blade 3 can be configured to rattle with an appropriate biasing force. Further, when the blade travels in one direction and the other direction, it is possible to adjust the biasing force applied to the blade by the biasing member to an appropriate balance. can do.

Further, in the embodiment, the configuration in which the blade is driven by the first electromagnetic actuator 61 and the second electromagnetic actuator 62 has been described. However, the blade is driven by a biasing member such as a drive spring shown in Japanese Patent Laid-Open No. 2002-049078. May be driven. In this case, the driving direction of the first blade 2 and the second blade 3 is in the order of FIG. 1, FIG. 3, FIG. 5 or in the order of FIG. 5, FIG. 3, FIG. Either way. However, since it is necessary to return to the set state before the imaging after the imaging, the first blade 2 and the second blade 3 are made to travel in the opposite direction. Therefore, even when the blade is driven by a spring or the like, when the blade travels in one direction and the opposite direction, the same effect as that of the above-described embodiment can be obtained.

Further, even when the blade is driven by the spring, a configuration including one blade may be adopted. Even in that case, it is possible to achieve the same effect as that of the shutter mounted on the camera adopting the electronic front curtain as described above.

Further, even when one blade is driven by a spring, the biasing force can be adjusted by locking one end of one of the two springs that are locked by the two arms to the eccentric pin. It goes without saying that it can be configured.

Further, in the embodiment, the configuration in which the first blade 2 and the second blade 3 are driven by the first electromagnetic actuator 61 and the second electromagnetic actuator 62 has been described. However, one of the first blade 2 and the second blade 3 may be driven by an electromagnetic actuator, and the other may be driven by a biasing member such as a spring. Even with such a configuration, it is possible to achieve the same effect as when the two blades are driven by the same drive source as described above.

INDUSTRIAL APPLICABILITY The present invention is suitably applied as a focal plane shutter of an image pickup apparatus such as a digital camera.

DESCRIPTION OF SYMBOLS 1... Base plate 1a... Opening 11... Through hole 12... Through hole 2... 1st blade|wing 21-24... Blade member 3... 2nd blade 31-34... Blade member 41... Main blade 42 for 1st blade... 1st blade Secondary arm 41a, 42a... Shaft 41b... First blade biasing spring (first biasing member)
41b1... 1st arm part 41b2... 2nd arm part 41b3... Coil part 41c... Through hole 42b... 1st blade|bias bias spring (2nd bias member).
42b1... 1st arm part 42b2... 2nd arm part 42b3... Coil part 42c... Through hole 43... 1st blade drive pin 44, 45... Shaft 51... 2nd blade main arm 52... 2nd blade slave arm 51a , 52a... Shaft 51b... Second blade biasing spring (third biasing member)
51b1... 1st arm part 51b2... 2nd arm part 51b3... Coil part 51c... Through hole 52b... 2nd blade biasing spring (4th biasing member)
52b1... 1st arm part 52b2... 2nd arm part 52b3... Coil part 52c... Through hole 53... 2nd blade drive pin 54... Eccentric pin 54a... Rotating shaft 54b... Adjusting shaft 54c... Head part 54d... Head part hole 54e ... Caulking portion 55... Shaft 56... Rotation stop 6... Drive mechanism

Claims (9)

A main plate having an opening,
Two first arms attached to the main plate,
A first blade attached to the first arm to open and close the opening of the main plate by traveling back and forth;
A first biasing member that biases one of the first arms in one traveling direction;
A second biasing member that biases the other of the first arms in the other traveling direction, the focal plane shutter. At a substantially intermediate position of the region where the first blade travels, the urging forces of the first urging member and the second urging member are substantially the same.
The focal plane shutter according to claim 1. At least one arm portion of at least one of the first biasing member and the second biasing member is hooked at one end to an eccentric pin arranged on the base plate,
The focal plane shutter according to claim 1. Two second arms attached to the main plate,
A second blade attached to the second arm to open and close the opening of the main plate by traveling back and forth;
A third urging member for urging one of the second arms in one traveling direction;
The focal plane shutter according to any one of claims 1 to 3, further comprising: a fourth biasing member that biases the other arm of the second arm in the other traveling direction. At a substantially intermediate position of the region where the second blade travels, the urging forces of the third urging member and the fourth urging member are substantially the same.
The focal plane shutter according to claim 4. At least one arm portion of at least one of the third urging member and the fourth urging member is hooked at one end to an eccentric pin arranged on the base plate,
The focal plane shutter according to claim 4 or 5. At least one of the first blade and the second blade is driven by an electromagnetic actuator arranged on the main plate,
The focal plane shutter according to any one of claims 1 to 6. At least one of the first blade and the second blade is driven by a spring of a drive mechanism arranged on the main plate,
The focal plane shutter according to any one of claims 1 to 6. A focal plane shutter according to any one of claims 1 to 8,
An image sensor,
An imaging device including.