Blade drive device and imaging device equipped with same

Abstract

To provide a blade driving device that can be operated at high speed while reducing the influence of partition plates partitioning a front blade chamber and a rear blade chamber from each other on blades.SOLUTION: A blade driving device 1 comprises: a pair of bottom boards 10, 12 in which an opening S is formed; front blades 31-34 that are movable between a first closing position for closing the opening S and a first retracted position located on a -Y direction side of the opening S; rear blades 35-38 that are movable between a second retracted position located on a +Y direction side of the opening S and a second closing position for closing the opening S; and a pair of partition plates 51, 52 that partition a space formed between the bottom boards 10, 12 into a front blade chamber R1 accommodating the front blades 31-34 and a rear blade chamber R2 accommodating the rear blades 35-38. The pair of partition plates 51, 52 include the first partition plate 51 that extends on the periphery of a first area S1 located on the -Y direction side of the opening S, and a second partition plate 52 that extends on the periphery of a second area S2 located on the +Y direction side of the opening S. The first partition plate 51 and the second partition plate 52 are different in at least one of material and thickness.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a blade drive device and an imaging device equipped with the same, and more particularly to a blade drive device for driving shutter blades in an imaging device such as a camera. [Background technology]

[0002] In an imaging device such as a camera, an exposure aperture is opened and closed by moving a shutter blade at high speed to expose an imaging element. Conventionally, a focal plane shutter is known as a blade driving device that drives a shutter blade at high speed, in which the shutter blades, which are composed of a leading blade and a trailing blade, are moved in the same direction by an actuator. In such a focal plane shutter, a space formed between two base plates is often divided into a leading blade chamber and a trailing blade chamber by a partition plate, and the leading blade is often housed in the leading blade chamber and the trailing blade is often housed in the trailing blade chamber (for example, see Patent Document 1).

[0003] If such a partition plate is deformed or damaged, it is considered that it will have a negative effect on the operation of the leading and trailing blades, so it is preferable that the rigidity of the partition plate is as high as possible. On the other hand, when a blade moving at high speed stops, the blade may vibrate in the thickness direction. For this reason, if the rigidity of the partition plate is made high, it is considered that the vibrating blade may come into contact with the partition plate and be damaged. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-281732 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the problems of the conventional technology, and has an object to provide a blade drive device that is capable of high-speed operation while reducing the influence on the blades of a partition plate that separates a leading blade chamber from a trailing blade chamber. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a blade drive device capable of high-speed operation while reducing the influence of a partition plate separating a leading blade chamber and a trailing blade chamber on the blades. This blade drive device includes a pair of base plates having an opening, at least one leading blade movable between a first closing position that closes the opening and a first retracted position located on the blade running direction side of the opening, at least one trailing blade movable between a second retracted position that is located on the opposite side of the opening in the blade running direction and a second closing position that closes the opening, and a space formed between the pair of base plates is divided into a leading blade chamber that houses the leading blade and a trailing blade chamber that houses the trailing blade. Work Cut Department It is equipped with. Recording Cut Department includes a first partition plate extending around a first region of the opening that is located on the blade travel direction side, and a second partition plate extending around a second region of the opening that is located on the opposite side to the blade travel direction. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a front view showing a blade drive device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view showing a part of the blade drive device shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. [Figure 4] FIG. 4 is a front view showing a state when the blade drive device shown in FIG. 1 has completed an exposure operation. [Diagram 5] 5 is a front view showing the relationship between a partition plate and a base plate in the blade drive device shown in FIG. [Figure 6]FIG. 6 is a schematic diagram showing the relationship between the rear blade and the partition plate when the exposure operation shown in FIG. 4 is completed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of a blade drive device according to the present invention will be described in detail with reference to Figs. 1 to 6. In Figs. 1 to 6, identical or corresponding components are denoted with the same reference numerals, and duplicated explanations will be omitted. In addition, in Figs. 1 to 6, the scale and dimensions of each component may be exaggerated, or some components may be omitted. In the following description, unless otherwise specified, terms such as "first" and "second" are used only to distinguish components from each other, and do not indicate a specific order or sequence.

[0009] Fig. 1 is a front view showing a blade drive device 1 in one embodiment of the present invention. The blade drive device 1 in this embodiment will be described as a focal plane shutter incorporated in an optical device such as a camera, but this is merely an example, and the blade drive device according to the present invention is not limited to such shutter applications. Fig. 1 shows the state when the setting operation by the camera is completed.

[0010] As shown in FIG. 1, the blade drive device 1 in this embodiment includes a first base plate 10 with a rectangular opening, a second base plate 12 (cover plate) with an opening of substantially the same shape as the opening of the first base plate 10, and eight blades 31 to 38 housed in a space formed between the pair of base plates 10 and 12. An exposure opening S is formed by the openings of the base plates 10 and 12. This blade drive device 1 is incorporated in an imaging device equipped with an imaging element (not shown) such as a CCD or CMOS sensor. The imaging element is located on the front side of the blade drive device 1 in FIG. 1, and light from a subject passes through the exposure opening S of the base plates 10 and 12 and enters the imaging element.

[0011] Fig. 2 is an exploded perspective view showing a part of the blade drive device 1, and Fig. 3 is a cross-sectional view taken along line AA in Fig. 1. In Fig. 3, in order to facilitate understanding, the thickness of some elements is exaggerated and the elements on the +Z direction side of the first base plate 10 are omitted from the illustration, for overall simplification. As shown in Fig. 2, each of the blades 31-38 is a thin plate-like member extending in the X direction as a whole. In this embodiment, of the blades 31-38, the blades 31-34 that are stacked in order become the leading blades that make up the leading curtain of the focal plane shutter, and the blades 35-38 that are stacked in order become the trailing blades that make up the trailing curtain.

[0012] A first partition plate 51 and a second partition plate 52 are disposed between the first base plate 10 and the second base plate 12 (not shown in FIG. 2). These partition plates 51, 52 are both disposed between the leading blades 31-34 and the trailing blades 35-38, and as shown in FIG. 3, a leading blade chamber R1 that houses the leading blades 31-34 is formed between the partition plates 51, 52 and the second base plate 12, and a trailing blade chamber R2 that houses the trailing blades 35-38 is formed between the partition plates 51, 52 and the first base plate 10.

[0013] The blade drive device 1 also includes leading blade arms 41, 42 connected to the leading blades 31-34, and trailing blade arms 43, 44 connected to the trailing blades 35-38. The leading blades 31-34 are connected to the leading blade arms 41, 42 by rivets or the like, respectively, and the leading blades 31-34 and the leading blade arms 41, 42 are rotatable relative to each other. Thus, the leading blades 31-34 and the leading blade arms 41, 42 form a link mechanism. The trailing blades 35-38 are connected to the trailing blade arms 43, 44 by rivets or the like, respectively, and the trailing blades 35-38 and the trailing blade arms 43, 44 are rotatable relative to each other. Thus, the trailing blades 35-38 and the trailing blade arms 43, 44 form a link mechanism.

[0014] The leading blade arm 41 is configured to be rotatable around the rotation shaft 21, and the leading blade arm 42 is configured to be rotatable around the rotation shaft 22. As shown in Fig. 2, a leading blade drive lever 61 is disposed on the +Z direction side of the first base plate 10. This leading blade drive lever 61 is configured to be rotatable around the rotation shaft 21, and a connecting portion 45 is provided at the tip of the leading blade drive lever 61. An arc hole 11 is formed in the first base plate 10 along an arc centered on the rotation shaft 21, and the connecting portion 45 of the leading blade drive lever 61 is connected to the connecting hole 41A of the leading blade arm 41 through this arc hole 11.

[0015] Further, the rear blade arm 43 is configured to be rotatable around the rotation shaft 23, and the rear blade arm 44 is configured to be rotatable around the rotation shaft 24. As shown in Fig. 2, a rear blade drive lever 62 is disposed on the +Z direction side of the first base plate 10. This rear blade drive lever 62 is configured to be rotatable around the rotation shaft 23, and a connecting portion 46 is provided at the tip of the rear blade drive lever 62. An arc hole 13 along an arc centered on the rotation shaft 23 is formed in the first base plate 10, and the connecting portion 46 of the rear blade drive lever 62 is connected to the connecting hole 43A of the rear blade arm 43 through this arc hole 13.

[0016] In this configuration, when the leading blade drive lever 61 is rotated around the rotation shaft 21 by a drive mechanism (not shown), the connecting portion 45 of the leading blade drive lever 61 moves along the arc hole 11, and the leading blade arm 41 connected to this connecting portion 45 rotates around the rotation shaft 21. When the leading blade arm 41 rotates around the rotation shaft 21, the leading blade arm 42 also rotates around the rotation shaft 22 due to the above-mentioned link mechanism, and the leading blades 31 to 34 move mainly in the Y direction on the XY plane (movement plane) while changing the overlapping areas.

[0017] Similarly, when the rear blade drive lever 62 is rotated around the rotation shaft 23 by a drive mechanism (not shown), the connecting portion 46 of the rear blade drive lever 62 moves along the arc hole 13, and the rear blade arm 43 connected to this connecting portion 46 rotates around the rotation shaft 23. When the rear blade arm 43 rotates around the rotation shaft 23, the above-mentioned link mechanism causes the rear blade arm 44 to also rotate around the rotation shaft 24, and the rear blades 35 to 38 move mainly in the Y direction on the XY plane (movement plane) while changing the overlapping areas.

[0018] In the completed state of the setting operation shown in FIG. 1, the leading blades 31-34 close the opening S, and the trailing blades 35-38 retreat to a position on the +Y direction side from the opening S. When the leading blade drive lever 61 and the trailing blade drive lever 62 are driven by the drive mechanism from this state, the leading blades 31-34 and the trailing blades 35-38 move mainly in the -Y direction (blade running direction) on the XY plane. At this time, the trailing blade 35 moves in the -Y direction while being separated from the leading blade 34 in the Y direction. Therefore, a slit for exposure is formed between the leading blade 34 and the trailing blade 35. This slit moves in the -Y direction together with the movement of the leading blades 31-34 and the trailing blades 35-38, and exposure of the imaging surface is performed. FIG. 4 shows the state when this exposure operation is completed.

[0019] In the completed state of the exposure operation shown in Fig. 4, the rear blades 35-38 close the opening S, and the leading blades 31-34 are retracted to a position on the -Y side of the opening S. In this manner, the leading blades 31-34 are movable between a closing position (first closing position (Fig. 1)) where they close the opening S and a retracted position (first retracted position (Fig. 4)) located on the -Y side (blade travel direction) of the opening S, and the rear blades 35-38 are movable between a retracted position (second retracted position (Fig. 1)) located on the +Y side of the opening S and a closing position (second closing position (Fig. 4)) where they close the opening.

[0020] 5 is a front view showing the relationship between the partition plates 51, 52 and the base plates 10, 12. As shown in FIG. 5, the first partition plate 51 extends around the first region S1 located on the -Y direction (blade running direction) side of the exposure opening S, and has a base 511 extending in the X direction and arm portions 512 extending from both sides of the base 511 toward the +Y direction. The second partition plate 52 extends around the second region S2 located on the +Y direction side of the exposure opening S, and has a base 521 extending in the X direction and arm portions 522 extending from both sides of the base 521 toward the -Y direction. The arm portions 512 of the first partition plate 51 and the arm portions 522 of the second partition plate 52 are arranged to face each other in the Y direction with a small gap therebetween.

[0021] Generally, in a focal plane shutter that drives the blades at high speed, the vibration and impact that the blades receive are greatest when the exposure operation is completed and the blades stop. Therefore, when the exposure operation is completed, the blades on the -Y direction (blade travel direction) side along which the blades 31 to 38 move will vibrate significantly. As described above, if the rigidity of the partition plate located near the blade that vibrates significantly is high, the vibrating blade may come into contact with the partition plate and be damaged. On the other hand, it is preferable to increase the rigidity of the partition plate in the opposite +Y direction to increase reliability.

[0022] From this viewpoint, in this embodiment, the partition plate separating the leading blade chamber R1 and the trailing blade chamber R2 is divided into two in the blade running direction, thereby reducing the influence of the partition plate on the blades 31 to 38 and enabling the blades 31 to 38 to move at high speed. That is, the material and thickness of the first partition plate 51 located in the -Y direction side area and the second partition plate 52 located in the +Y direction side area can be changed according to the characteristics of the blades passing nearby. For example, the first partition plate 51 located in the -Y direction side area where the blades are expected to swing significantly when the exposure operation is completed can be made of resin, and when the nearby blades swing in the thickness direction (Z direction), the partition plate 51 can bend to reduce damage to the blades, while the second partition plate 52 located in the +Y direction side area can be made of a highly rigid metal.

[0023] In this way, in order to effectively respond to the swaying of the blades on the -Y direction side and ensure the rigidity of the partition plate on the +Y direction side, it is preferable that the first area S1 surrounded by the first partition plate 51 is smaller than half of the total area of ​​the opening S, and that the second area S2 surrounded by the second partition plate 52 is larger than half of the total area of ​​the opening S.

[0024] In addition, the inventor discovered in the process of developing the present invention that the second rear blade (rear blade 36) swings the most in the thickness direction when the exposure operation is completed, and found that a good balance between dealing with the swing of the blades and ensuring the rigidity of the blades is achieved when the dividing position G of the partition plate 51 and the partition plate 52 is set near the area W (shaded area) where the rear blade 35 (first rear blade) and the rear blade 36 (second rear blade) overlap when the exposure operation is completed, as shown in Fig. 6. Therefore, it is preferable that the first partition plate 51 and the second partition plate 52 are disposed so as to face each other in the Y direction near the area W where the rear blade 35 and the rear blade 36 overlap when the rear blades 35 to 38 move to a position (second closing position) where they close the opening S.

[0025] In addition, the terms used in this specification, such as "top," "bottom," "upper," "lower," "upper side," "lower side," "bottom," and other terms indicating positional relationships, are used in relation to the illustrated embodiment and may vary depending on the relative positional relationship of the devices.

[0026] As described above, according to the first aspect of the present invention, there is provided a blade drive device capable of high-speed operation while reducing the influence of a partition plate separating a leading blade chamber and a trailing blade chamber on the blades. This blade drive device includes a pair of base plates having an opening, at least one leading blade movable between a first closing position that closes the opening and a first retracted position located on the blade running direction side of the opening, at least one trailing blade movable between a second retracted position that closes the opening and a second closing position that closes the opening, and a pair of partition plates that divide a space formed between the pair of base plates into a leading blade chamber that houses the leading blade and a trailing blade chamber that houses the trailing blade. The pair of partition plates includes a first partition plate extending around a first region located in the blade running direction of the opening, and a second partition plate extending around a second region located on the opposite side of the opening to the blade running direction. It is preferable that at least one of the material and thickness of the first partition plate and the second partition plate is different.

[0027] In this way, by separating the leading blade chamber that houses the leading blade from the rear blade chamber that houses the rear blade with two partition plates separated in the blade running direction, it is possible to change the material and thickness of the partition plate according to the characteristics of the blades passing nearby so as to reduce the influence on the blades. Therefore, the blade drive device according to the present invention makes it possible to operate the blades at high speed while reducing the influence on the blades of the partition plate that separates the leading blade chamber and the rear blade chamber.

[0028] Preferably, said first area of ​​said opening is less than half the total area of ​​said opening and said second area of ​​said opening is greater than half the total area of ​​said opening.

[0029] The at least one rear blade may include a first rear blade that enters the opening first when moving from the second retracted position to the second closing position, and a second rear blade that enters the opening following the first rear blade when moving from the second retracted position to the second closing position. In this case, the first and second partition plates are preferably arranged to face each other in the blade running direction near an overlapping area between the first and second rear blades at the second closing position.

[0030] According to a second aspect of the present invention, there is provided an imaging device comprising the above-mentioned blade drive device and an imaging element arranged on a surface where an image is formed by light that has passed through the openings in the pair of base plates of the blade drive device.

[0031] Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments and may be embodied in various different forms within the scope of the technical concept thereof. [Explanation of symbols]

[0032] 1. Blade drive device 10,12 Main plate 11,13 Arc hole 21~24 Rotation axis 31~34 Leading wing 35~38 Rear wing 41,42 Leading blade arm 43,44 Rear wing arm 45,46 Connection part 51 First Partition 52 Second Partition 61 Leading blade drive lever 62 Rear blade drive lever 511,521 Frame 512,522 Arm G division position R1 Front wing room R2 Rear wing room S opening S1 First Area S2 Second Area

Claims

1. A pair of base plates having openings formed therein; at least one leading blade movable between a first closing position that closes the opening and a first retracted position that is located on the blade running direction side of the opening; at least one rear blade movable between a second retracted position located on the opposite side of the opening in the blade travel direction and a second closing position that closes the opening; a partition portion that divides a space formed between the pair of base plates into a leading blade chamber that houses the leading blade and a trailing blade chamber that houses the trailing blade; Equipped with The partition portion is a first partition plate extending around a periphery of a first region located on the blade travel direction side of the opening; a second partition plate extending around a periphery of a second region located on an opposite side of the opening with respect to the blade travel direction; Including, Blade drive device.

2. The blade drive device according to claim 1 , wherein at least one of the material and the thickness of the first partition plate and the second partition plate is different.

3. the first area of ​​the opening is less than half of a total area of ​​the opening; the second area of ​​the opening is greater than half of the total area of ​​the opening; The blade drive device according to claim 1 or 2.

4. The at least one rear wing is a first rear blade that enters the opening first when moving from the second retracted position to the second closing position; a second rear blade that enters the opening following the first rear blade when moving from the second retracted position to the second closing position; Including, the first partition plate and the second partition plate are disposed to face each other in the blade running direction near a region where the first rear blade and the second rear blade overlap at the second closing position. The blade drive device according to claim 3 .

5. The blade drive device according to any one of claims 1 to 4, an imaging element disposed on a surface on which light transmitted through the openings of the pair of base plates of the blade drive device forms an image; An imaging device comprising:

Images