JP2019061127A - Focal plane shutter and imaging device - Google Patents

Abstract

To provide a focal plane shutter capable of effectively braking blades with a relatively simple configuration.SOLUTION: A focal plane shutter includes: a bottom board having an opening for exposure; blades for moving so as to switch an open/closed state of the opening; a driving lever coupled with the blades for driving the blades; a driving spring for biasing the driving lever; a link lever of which one end is coupled with the driving lever; a cam plate coupled with the link lever so as to rotate the other end of the link lever; and a driving unit for rotating the cam plate.SELECTED DRAWING: Figure 1

Description

  One aspect of the present invention relates to a focal plane shutter or the like used for a camera.

  In a focal plane shutter that exposes an image pickup device or a film by opening and closing an opening (also referred to as an exposure opening or an image frame) by a blade, a blade disposed in a blade chamber formed between a base plate and an auxiliary base plate Is driven by a drive mechanism to change the open / close state of the opening and to perform exposure. In such focal plane shutters, it is required to operate the blades at high speed, but when the blades are operated at high speed, members such as the blades may be broken during operation. Therefore, various configurations have been devised as a brake mechanism for relieving the impact at the time of operation of the blades. For example, Patent Document 1 discloses a configuration that uses a cam member having a cam groove to cushion an impact at the time of operation of a blade.

JP, 2017-3628, A

  However, in the conventional configuration including the configuration described in Patent Document 1, the cam having a complicated shape is adopted, and it is difficult to easily manufacture the cam member. In addition, there has been a problem that stable operation can not be performed when the cam groove is worn by continuous use.

  The present invention adopts the following means in order to solve the above problems. In the following description, in order to facilitate understanding of the invention, reference numerals and the like in the drawings are appended in parentheses, but each component of the present invention is not limited to the appended ones. It should be interpreted broadly to the extent that the vendor can understand technically.

One means of the present invention is
A main plate (1) having an opening for exposure;
A blade (2) operable to switch the open / close state of the opening;
A drive lever (7a, 5) connected to the blade and driving the blade;
A drive spring (6a) for biasing the drive lever;
A link lever (7b) having one end (7c) connected to the drive lever;
A cam plate (8) connected to the link lever to turn the other end (7d) of the link lever;
And a drive unit (9) for rotating the cam plate.
It is a focal plane shutter.

  According to the focal plane shutter of the above configuration, by using the cam plate and the link lever, it is possible to perform control such as braking of the blade without using a cam member having a complicated shape. In addition, since the cam groove is not used, it is possible to suppress a change in operation due to wear.

In the above focal plane shutter, preferably
The drive lever (7a, 5) pivots around a rotation shaft (6b) on the base plate,
The drive spring (6a) is a torsion coil spring attached to the rotation shaft,
The torsion coil spring can adjust the biasing force.

  According to the focal plane shutter of the above configuration, by adjusting the biasing force of the torsion coil spring, the braking force applied to the blade can be adjusted. As a result, it is possible to adjust the braking force on the blades by relatively simple processing.

In the above focal plane shutter, preferably
The link lever is connected to the drive lever so that the drive force applied to the blade via the drive lever is weak near the operation end position of the blade.

  According to the focal plane shutter of the above configuration, the link lever can be configured to apply a braking force for suppressing breakage of the blade during blade operation.

In the above focal plane shutter, preferably
The drive unit is a motor.

  According to the focal plane shutter of the above configuration, driving and braking of the blades can be performed by rotating the cam plate with the motor having a relatively simple configuration.

In the above focal plane shutter, preferably
The motor brakes the motion of the blade by a short brake near the operation end position of the blade.

  According to the focal plane shutter of the above configuration, by using the short brake of the motor, it is possible to effectively brake the blade and to suppress breakage of the blade.

In the above focal plane shutter, preferably
The motor brakes the movement of the blade by operating in the opposite direction to that at the time of driving the blade near the operation end position of the blade.

  According to the focal plane shutter of the above configuration, by rotating the motor in the opposite direction to that at the time of driving, it is possible to effectively brake the blades and to suppress breakage of the blades.

  Furthermore, the present invention includes an imaging device such as a camera including any of the above-described focal plane shutters and an imaging device.

  According to the imaging device of the above configuration, it is possible to effectively brake the blade at the operation end position of the blade, and to configure an imaging device capable of suppressing breakage of the blade and noise at the time of driving the blade. Further, by not including the cam groove, it is possible to suppress that the operation of the blade becomes unstable due to wear and the like.

FIG. 1 is a plan view of a focal plane shutter in a state before blade travel. FIG. 2 is a plan view of the focal plane shutter while the blade is traveling. FIG. 3 is a plan view of the focal plane shutter in a state where the blade travel is completed. FIG. 4 is a plan view of the focal plane shutter during blade braking. FIG. 5 is a plan view of the focal plane shutter during blade charging.

Embodiments according to the present invention will be specifically described with reference to the drawings according to the following configuration. However, the embodiments described below are merely examples of the present invention, and the technical scope of the present invention is not to be interpreted in a limited manner. In the drawings, the same components are denoted by the same reference numerals, and the description thereof may be omitted.
1. Embodiment 2. Supplementary items

<1. Embodiment>
In order to operate the blades, the focal plane shutter of this embodiment is configured to transmit the driving force from the motor to the blades through the cam plate, the link lever, the drive lever, and the arm, and is given to the blades by the link levers. One of the features is that the driving force and the braking force are adjusted. Hereinafter, the focal plane shutter of the present embodiment will be specifically described with reference to the drawings.

  FIGS. 1-5 is a top view of the focal plane shutter 10 of this embodiment, Comprising: It is a figure which shows a respectively different state. FIG. 1 shows a state before traveling of the blade, FIG. 2 shows a state during traveling of the blade, FIG. 3 shows a state after traveling of the blade, FIG. 4 shows a state during braking of the blade, and FIG.

  As illustrated, the focal plane shutter 10 according to the present embodiment includes a base plate 1, blades 2, arms 3a and 3b, an actuator 4, a drive pin 5, a ratchet 6, a plate spring 6a, a drive lever 7a, a link lever 7b, The cam plate 8 and the motor 9 are included. In the present embodiment, the configuration in which the focal plane shutter 10 has only the blades 2 is described, but the configuration of the present embodiment is also applicable to a configuration having two sets of blades, a front blade and a rear blade. In this case, the configuration of the present embodiment may be applied to both the leading blade and the trailing blade, or may be adopted to only one of them.

<Ground plate 1>
The ground plane 1 is a substrate portion of the focal plane shutter 10, and a rectangular opening 1a functioning as an exposure opening (image frame) is formed. An actuator 4, a drive pin 5, a ratchet 6, a plate spring 6a, a drive lever 7a, a link lever 7b, a cam plate 8, a drive mechanism for driving the blades 2 on the side of the opening 1a on the ground plate 1 And the motor 9 and the like are arranged. Although not shown in the drawings, a cover plate is disposed at a position facing the main plate 1, and a blade chamber is formed in a space between the main plate 1 and the cover plate. In the blade chamber, the blade 2, the arms 3a and 3b, etc. are disposed. The cover plate has an opening similar to that of the ground plate 1, and the opening 1 a of the ground plate 1 and the opening of the cover plate define the outer edge of the exposure opening. In addition to the base plate 1 and the cover plate, an intermediate plate having an opening may be disposed similarly. In this case, the outer edge of the exposure opening is defined by the overlapping of the openings of the main plate 1, the cover plate, and the intermediate plate.

<Feather 2>
The blade 2 is connected to the drive pin 5 and the drive lever 7a via the arms 3a and 3b. As described above, the blades 2 are disposed in the blade chamber formed between the main plate 1 and the cover plate. The blades 2 are each formed of a plurality of substantially rectangular plate-like blade members, and may be called a blade group. However, the number of blades 2 may be one, or two or more.

<Arms 3a and 3b>
Arms 3a and 3b are connected to blade 2 respectively. One end of the arm 3a is connected to an axis arranged on the ground plane 1 and moves on the basis of this axis. One end of the arm 3 b is connected to the drive pin 5 and moves in accordance with the operation of the drive pin 5. That is, the arms 3 a and 3 b transmit the power given to the drive pin 5 to the blade 2.

<Drive lever 7a, drive pin 5>
The drive lever 7a is a plate-like extended member, and the arm 3b is connected to one end via the drive pin 5 at one end, and the link lever 7b is connected to the other end via the connection pin 7c. The vicinity of the central portion of the drive lever 7 a is connected to the ground plate 1 by a shaft 6 b arranged on the ground plate 1. Thus, the drive lever 7a pivots about the shaft 6b.

  The drive lever 7a is biased in the clockwise direction by a drive spring 6a disposed on the shaft 6b. The drive lever 7a operates by the attraction force generated between the drive pin 5 and the actuator 4 and the biasing force received from the drive spring 6a.

  The drive pin 5 includes an iron piece disposed at a position facing the actuator 4 and is connected to the drive lever 7a and the arm 3b. The drive pin 5 generates an attractive force with the actuator 4 in a state where the coil of the actuator 4 is energized and the actuator 4 is excited. When the drive pin 5 is attracted to the actuator 4, the drive pin 5 is fixed in position against the biasing force of the drive spring 6a. The drive lever 7a and the drive pin 5 may be collectively referred to as a drive lever.

<Actuator 4>
The actuator 4 is configured to have a coil and a permanent magnet, and is excited by energization of the coil to be in a state of having a magnetic force. That is, the actuator 4 is an electromagnetic actuator utilizing an electromagnetic force. When the actuator 4 is excited, the actuator 4 sucks the drive pin 5.

<Ratchet 6>
The ratchet 6 is disposed with the shaft 6b as a rotation axis, and is connected to one arm of the drive spring 6a. The ratchet 6 is rotated by a rotating member (not shown). When the ratchet 6 pivots, the position of one of the arms of the drive spring 6a changes, which changes the biasing force generated by the drive spring 6a.

<Drive spring 6a>
The drive spring 6a is a torsion coil spring disposed on the shaft 6b. The drive spring 6a has a cylindrical main body and two arms, one arm being connected to the ratchet 6 and the other arm biasing the drive lever 7a. The drive spring 6a applies a biasing force in the clockwise direction to the drive lever 7a.

<Link lever 7b>
The link lever 7b is a plate-like extended member, one end of which is connected to the drive lever 7a, and the other end of which is connected to the cam plate 8 by a shaft 7d. The link lever 7b is operated by the rotation of the cam plate 8 and the drive lever 7a. The rotation of the cam plate 8 is transmitted to the drive lever 7a via the link lever 7b, but the drive transmitted to the drive lever 7a according to the amount of rotation of the cam plate 8 depending on the positions of the cam plate 8 and the link lever 7b. Force changes. In particular, in the focal plane shutter 10 of the present embodiment, the link lever 7 b acts to weaken the driving force applied to the blade 2 via the drive lever 7 a at the operation end position of the blade 2.

<Cam plate 8>
The cam plate 8 is a disk-like member rotatably fixed to the shaft of the base plate 1 and has a gear on the outer periphery. The gear on the outer periphery of the cam plate 8 meshes with the gear 9 a of the motor 9, thereby receiving a driving force from the motor 9. The cam plate 8 has a shaft 7d connected to the drive lever 7a. The cam plate 8 basically pivots in one clockwise direction.

<Motor 9>
The motor 9 is disposed on the ground plate 1 and driven by an externally applied power. The motor 9 has a gear 9 a connected to the shaft and meshing with a gear on the outer periphery of the cam plate 8. The power generated by the motor 9 is transmitted to the blade 2 through the cam plate 8, the link lever 7b, the drive lever 7a, the drive pin 5, and the arm 3b.

<Operation>
Next, the operation of the focal plane shutter 10 will be described with reference to the drawings showing each state.

  FIG. 1 shows the focal plane shutter 10 in a state before the blade travels. In this state, the actuator 4 is energized and the drive pin 5 is attracted to the actuator 4. As illustrated, the blade 2 is in a state in which the opening 1 a is opened. From this state, the energization of the actuator 4 is canceled, and the energization of the motor 9 is performed, whereby the blade 2 travels.

  FIG. 2 shows the focal plane shutter 10 during blade travel. In this state, the blade 2 is traveling by the biasing force of the driving spring 6 a and the driving force from the motor 9.

  FIG. 3 shows the focal plane shutter 10 in a state where the blade travel is completed. In this state, depending on the state of the link lever 7b, the driving force given to the drive lever 7a is weak against the rotation of the cam plate 8, and the driving force given to the blade 2 is weak. In other words, the braking force is applied to the blades 2. As a result, the traveling speed of the blades 2 is reduced, and the impact at the end of traveling is mitigated. Further, immediately before this state, a force (a braking force) in the reverse direction to the traveling direction is applied to the blades 2 by the short brake of the motor 9 or the drive in the reverse direction.

  FIG. 4 shows the focal plane shutter 10 during blade braking. In this state, the shaft 7d connecting the cam plate 8 and the link lever 7b passes through the top dead center, and a force in the charge direction is applied to the drive lever 7a. In this state, the biasing force of the drive spring 6 a acts as a braking force on the blade 2.

  FIG. 5 shows the focal plane shutter 10 during blade charging. In this state, the driving pin 5 is moved in the counterclockwise direction by the driving force from the motor 9 to be in the state before traveling of the blade shown in FIG.

  According to the focal plane shutter 10 of the present embodiment having the configuration operable as described above, the configuration including the cam plate 8 and the link lever 7 b allows the blade to be used without using a cam member of a complicated shape. It is possible to perform control such as 2 braking. In addition, since the cam groove is not used, it is possible to suppress a change in operation due to wear.

  Further, in the focal plane shutter 10 of the present embodiment, the drive lever 7a is pivoted about the shaft 6b, and the torsion coil spring 6a capable of adjusting the biasing force is disposed on the shaft 6b. Therefore, by adjusting the biasing force of the torsion coil spring 6a, it is possible to adjust the braking force applied to the blade 2 and the like. As a result, it is possible to adjust the braking force on the blades 2 by relatively simple processing.

  Further, in the focal plane shutter 10 of the present embodiment, the link lever 7 b is arranged in the vicinity of the operation end position of the blade 2 so that the driving force applied to the blade 2 via the drive lever 7 a becomes weak. Therefore, the link lever 7b can be configured to apply a braking force for suppressing breakage of the blade 2 at the time of blade operation.

  Further, in the focal plane shutter 10 of the present embodiment, the motor 9 is provided as a drive unit. As a result, by rotating the cam plate 8 with the motor 9 having a relatively simple configuration, driving and braking of the blades 2 can be performed.

  Further, in the focal plane shutter 10 of the present embodiment, since the blade 2 can be braked using the short brake of the motor 9, the blade 2 can be effectively braked to prevent damage to the blade 2 It is a structure.

  Further, in the focal plane shutter 10 of the present embodiment, the blade 2 can be braked by rotating the motor 9 in the direction opposite to the direction in which the blade 2 is driven. Therefore, the blade 2 can be braked effectively. And the structure which can suppress the failure | damage of the blade | wing 2. FIG.

<2. Additional Notes>
The specific description of the embodiment of the present invention has been described above. The above description is merely an embodiment, and the scope of the present invention is not limited to this embodiment, and can be broadly interpreted to a range that can be grasped by those skilled in the art based on the same technical concept. is there.

  The operation of the focal plane shutter 10 in the above embodiment is merely an example, and may be configured to operate other than the above. For example, in the focal plane shutter 10 of the embodiment, the drive pin 5 has an iron piece, but a configuration in which the drive pin 5 has a permanent magnet may be adopted.

  The focal plane shutter of the present invention is used as a shutter device or the like for an imaging device.

DESCRIPTION OF SYMBOLS 1 ... Ground plate 1a ... Opening part 2 ... Blade 3a, 3b ... Arm 4 ... Actuator 5 ... Drive pin 6 ... Ratchet 6a ... Plate spring 6b ... Axis 7a ... Drive lever 7b ... Link lever 7c ... Connection pin 7d ... Axis 8 ... Cam Plate 9: Motor 9a: Gear 10: Focal plane shutter

Claims (7)

A ground plate having an opening for exposure;
A blade operable to switch the open / close state of the opening;
A drive lever connected to the blade and driving the blade;
A drive spring for biasing the drive lever;
A link lever whose one end is connected to the drive lever;
A cam plate connected to the link lever so as to turn the other end of the link lever;
And a drive unit for rotating the cam plate.
Focal plane shutter. The drive lever pivots about a rotation axis on the base plate,
The drive spring is a torsion coil spring attached to the rotating shaft,
The torsion coil spring is adjustable in biasing force.
The focal plane shutter according to claim 1. The link lever is connected to the drive lever so that the driving force applied to the blade via the drive lever is weak near the operation end position of the blade.
The focal plane shutter according to claim 1. The drive unit is a motor,
The focal plane shutter according to any one of claims 1 to 3. The motor brakes the motion of the blade by a short brake near the operation end position of the blade.
The focal plane shutter according to claim 4. The motor brakes the motion of the blade by operating in the opposite direction to that at the time of driving the blade near the operation end position of the blade.
The focal plane shutter according to claim 4. A focal plane shutter according to any one of claims 1 to 6,
An imaging device;
Imaging device.

Images