Blade drive device and imaging device equipped with same

Abstract

To provide a blade driving device that can suppress dispersion of worn powders generated in the connecting part of a blade and an arm to the outside.SOLUTION: A blade driving device 1 includes: a ground plane 10 with an opening S for guiding light from an object into an imaging element; at least blades 31 to 34 movable to open or close the opening S on an XY plane; and arms 41 and 42 connected to the blades 31 to 34. The arms 41 and 42 each include: plate parts 100 and 200 extending along the XY plane; and shielding walls 110 and 120 extending from edge parts of the plate parts 100, 200 into a +Z direction perpendicular to the plate parts 100, 200.SELECTED DRAWING: Figure 3

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 the shutter blades of a digital camera or the like. [Background technology]

[0002] In digital cameras and the like, shutter blades are moved at high speed to open and close an exposure aperture, thereby exposing an image sensor to light. In a blade drive device that drives such shutter blades, wear powder and dust may be generated inside the device due to friction between the arm attached to the blade or the blade and the base plate. If such wear powder and dust adheres to the image sensor of the camera, the quality of the image captured by the image sensor decreases, so various mechanisms have been devised to prevent the generated wear powder and dust from adhering to the image sensor (see, for example, Patent Document 1).

[0003] In recent years, with the increase in the number of pixels in the image sensor of digital cameras, the impact of the above-mentioned wear powder and dust on image quality has become greater. Also, the faster the shutter speed, the greater the degree of wear between components, making it easier for wear powder and dust to be generated. For this reason, there is a demand for technology that can effectively suppress the diffusion of wear powder and dust generated within the device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-280066 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 aims to provide a blade drive device that can prevent wear powder and dust generated at the connection between the blade and the arm from diffusing to the outside of the arm. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a blade drive device capable of suppressing the diffusion of wear powder and dust generated at the joint between the blade and the arm to the outside of the arm. This blade drive device includes a base plate having an opening formed therein for directing light from a subject to an image sensor, at least one blade movable on a moving plane so as to open and close the opening, and a blade drive mechanism for the at least one blade. Rotatable via joint and at least one arm connected to the at least one arm, the at least one arm extending along the plane of movement. The connecting portion is attached and a plate portion that is perpendicular to the edge of the plate portion. Surrounding the joint and an extending shielding wall. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a front view showing a schematic diagram of a blade drive device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a front view showing a schematic state in which a cover plate of the blade drive device shown in FIG. 1 is removed. [Diagram 3] FIG. 3 is a perspective view showing a leading blade arm of the blade drive device shown in FIG. [Figure 4A] FIG. 4A is a vertical sectional view of the leading blade arm shown in FIG. [Figure 4B] FIG. 4B is a vertical sectional view of the leading blade arm shown in FIG. 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 4B. In Figs. 1 to 4B, identical or corresponding components are denoted with the same reference numerals, and duplicated descriptions will be omitted. In addition, in Figs. 1 to 4B, 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 according to an embodiment of the present invention. The blade drive device 1 according to 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. In this embodiment, for convenience, the front side of the paper in FIG. 1 will be referred to as the "front" or "forward" and the back side of the paper will be referred to as the "rear" or "rearward".

[0010] As shown in FIG. 1, the blade drive device 1 in this embodiment includes a base plate 10 with a rectangular opening, a cover plate 20 with an opening of substantially the same shape as the opening of the base plate 10, and eight blades 31 to 38 accommodated in a space formed between the base plate 10 and the cover plate 20. An exposure opening S is formed by the opening of the base plate 10 and the opening of the cover plate 20. This blade drive device 1 is incorporated into an imaging device equipped with an imaging element (not shown) such as a CCD or CMOS sensor. The imaging element is located in front of the blade drive device 1 in FIG. 1, and light from a subject passes through the exposure opening S of the base plate 10 and the cover plate 20 to enter the imaging element in front.

[0011] FIG. 2 is a front view showing a state in which the cover plate 20 is removed. As shown in FIG. 2, each of the blades 31 to 38 is a thin plate-like member extending in the X direction as a whole. In this embodiment, the blades 31 to 34 of the blades 31 to 38 that are stacked in order become leading blades that constitute the leading curtain of the focal plane shutter, and the blades 35 to 38 that are stacked in order become trailing blades that constitute the trailing curtain. An intermediate plate (not shown) is disposed between the base plate 10 and the cover plate 20, and the leading blades 31 to 34 are housed in a space formed between the intermediate plate and the cover plate 20, and the trailing blades 35 to 38 are formed in a space formed between the intermediate plate and the base plate 10.

[0012] 2, the blade drive device 1 includes leading blade arms 41, 42 connected to leading blades 31-34, and trailing blade arms 43, 44 connected to trailing blades 35-38. The leading blade 31 is connected to the leading blade arms 41, 42 by connecting portions 51, 52, respectively, the leading blade 32 is connected to the leading blade arms 41, 42 by connecting portions 53, 54, respectively, the leading blade 33 is connected to the leading blade arms 41, 42 by connecting portions 55, 56, respectively, and the leading blade 34 is connected to the leading blade arms 41, 42 by connecting portions 57, 58, respectively. These connecting portions 51-58 are formed by rivets made of, for example, relatively soft steel. The leading blades 31-34 and the leading blade arms 41, 42 are rotatably connected to each other by fastening these connecting portions 51-58 to rivet holes formed in the leading blade arms 41, 42. In this manner, the leading blades 31-34 and the leading blade arms 41, 42 form a link mechanism.

[0013] Further, the rear blade 35 is connected to the rear blade arms 43, 44 by the connecting parts 61, 62, the rear blade 36 is connected to the rear blade arms 43, 44 by the connecting parts 63, 64, the rear blade 37 is connected to the rear blade arms 43, 44 by the connecting parts 65, 66, and the rear blade 38 is connected to the rear blade arms 43, 44 by the connecting parts 67, 68. These connecting parts 61-68 are formed by rivets made of relatively soft steel, for example. By crimping these connecting parts 61-68 into rivet holes formed in the rear blades 35-38, the rear blades 35-38 and the rear blade arms 43, 44 are connected to each other rotatably. In this manner, the rear blades 35-38 and the rear blade arms 43, 44 form a link mechanism.

[0014] The leading blade arm 41 is configured to be rotatable around a support shaft 71, and the leading blade arm 42 is configured to be rotatable around a support shaft 72. A drive pin 73 connected to a drive lever (not shown) is inserted into the leading blade arm 41. A drive mechanism (not shown) known in the art is provided behind the base plate 10, and the leading blade arm 41 rotates around the support shaft 71 by using this drive mechanism. When the leading blade arm 41 rotates around the support shaft 71, the leading blade arm 42 also rotates around the support shaft 72 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.

[0015] Further, the rear blade arm 43 is configured to be rotatable around a support shaft 81, and the rear blade arm 44 is configured to be rotatable around a support shaft 82. Further, a drive pin 83 connected to a drive lever (not shown) is inserted into the rear blade arm 43. A drive mechanism (not shown) known in the art is provided behind the base plate 10, and the drive lever is rotated around the support shaft 81 using this drive mechanism, so that the rear blade arm 43 rotates around the support shaft 81. When the rear blade arm 43 rotates around the support shaft 81, the above-mentioned link mechanism causes the rear blade arm 44 to also rotate around the support shaft 82, and the rear blades 35 to 38 move mainly in the Y direction on the XY plane (movement plane) while changing the overlapping areas of the rear blades 35 to 38.

[0016] Fig. 3 is a perspective view showing the leading blade arms 41 and 42. As shown in Fig. 3, the leading blade arm 41 is formed, for example, by drawing or forging a metal, and includes a plate portion 100 extending along the XY plane, and a shielding wall 110 extending forward (in the +Z direction) from an edge of the plate portion 100. The plate portion 100 is formed with rivet holes 120 into which the above-mentioned connecting portions 51, 53, 55, and 57 (rivets) are respectively crimped, a shaft hole 130 into which the support shaft 71 is inserted, and a shaft hole 140 into which the drive pin 73 is inserted.

[0017] Similarly, the leading blade arm 42 is also formed by, for example, drawing or forging a metal. As shown in Fig. 3, the leading blade arm 42 includes a plate portion 200 extending along the XY plane, and a shielding wall 210 extending forward (in the +Z direction) from an edge of the plate portion 200. The plate portion 200 is formed with rivet holes 220 into which the above-mentioned connecting portions 52, 54, 56, 58 (rivets) are respectively fastened, and a shaft hole 230 into which the support shaft 72 is inserted.

[0018] 4A and 4B are vertical cross-sectional views of the leading blade arms 42, 42, respectively. As described above, considering that the leading blade arms 41, 42 are formed by drawing or forging, the thickness T2 of the shielding walls 110, 210 of the leading blade arms 41, 42 is preferably, for example, one or more times the thickness T1 of the plate parts 100, 200, and more preferably about three times. For example, the thickness T1 of the plate parts 100, 200 of the leading blade arms 41, 42 is about 0.15 mm, and the thickness T2 of the shielding walls 110, 210 is 0.3 mm to 0.5 mm. In this embodiment, the thickness of the plate part 100 and the shielding wall 110 of the leading blade arm 41 is the same as the thickness of the plate part 200 and the shielding wall 210 of the leading blade arm 42, but these thicknesses may be different from each other.

[0019] As shown in FIG. 4A, an adhesive layer 150 is formed on the front surface (surface on the +Z direction side) of the plate portion 100 of the leading blade arm 41. Similarly, as shown in FIG. 4B, an adhesive layer 250 is formed on the front surface (surface on the +Z direction side) of the plate portion 200 of the leading blade arm 42. These adhesive layers 150, 250 may be formed, for example, by applying a highly viscous liquid adhesive to the plate portions 100, 200 of the leading blade arms 41, 42, or by attaching a double-sided adhesive sheet having the same shape as the plate portions 100, 200 of the leading blade arms 41, 42 to the plate portions 100, 200. As such a liquid adhesive, for example, a silicon-based liquid adhesive containing fluorine, such as Dusttrap (trademark) manufactured by Harves Co., Ltd., may be used.

[0020] When the drive lever is rotated around the support shaft 71 using the above-mentioned drive mechanism, the leading blade arm 41 rotates around the support shaft 71 by the above-mentioned link mechanism, and the leading blades 31 to 34 move in the Y direction while rotating relative to the leading blade arm 41 at the connecting portions 51, 53, 55, and 57. Also, the leading blade arm 42 rotates around the support shaft 72 by the above-mentioned link mechanism, and the leading blades 31 to 34 move in the Y direction while rotating relative to the leading blade arm 42 at the connecting portions 52, 54, 56, and 58. As described above, since the connecting portions 51 to 58 are swaged to the rivet holes 120 and 220 of the leading blade arms 41 and 42, it is considered that wear powder and dust will be generated when the connecting portions 51 to 58 rotate relative to the leading blade arms 41 and 42.

[0021] Here, the leading blade arms 41, 42 in this embodiment have the shielding walls 110, 210 extending from the edges of the plate parts 100, 200 toward the imaging element side (+Z direction side), so that even if wear powder or dust is generated from the connecting parts 51 to 58, the generated wear powder or dust can be kept in the spaces R1, R2 (see Figs. 4A and 4B) inside the shielding walls 110, 210. Therefore, the generated wear powder or dust is prevented from diffusing to the outside of the shielding walls 110, 210 of the leading blade arms 41, 42. As a result, the generated wear powder or dust is prevented from adhering to the imaging element in the camera through the opening of the cover plate 20, and the deterioration of the image quality can be prevented.

[0022] Furthermore, in this embodiment, the adhesive layers 150, 250 are formed on the imaging element side surfaces (surfaces on the +Z direction side) of the plate portions 100, 200 of the leading blade arms 41, 42, respectively, so that wear powder and dust present in the spaces R1, R2 inside the shielding walls 110, 210 are attracted to and captured by the adhesive layers 150, 250. Therefore, the wear powder and dust in the spaces R1, R2 inside the shielding walls 110, 210 are effectively prevented from diffusing to the outside of the shielding walls 110, 210. Note that such adhesive layers 150, 250 may also be formed on the inner circumferential surfaces of the shielding walls 110, 210.

[0023] Although not shown in the figure, the rear blade arms 43, 44 are also provided with a shielding wall and an adhesive layer, similar to the leading blade arms 41, 42. Therefore, even if wear powder or dust is generated from the connecting parts 61-68, the generated wear powder or dust can be kept in the space inside the shielding wall, and can be further adsorbed and captured by the adhesive layer. Therefore, the wear powder or dust generated from the connecting parts 61-68 is effectively prevented from diffusing to the outside of the shielding wall, and the wear powder or dust is prevented from adhering to the imaging element in the camera through the opening of the cover plate 20.

[0024] As described above, according to the first aspect of the present invention, there is provided a blade drive device capable of suppressing the diffusion of wear powder and dust generated at the connection between the blade and the arm to the outside of the arm. This blade drive device includes a base plate having an opening formed therein for guiding light from a subject to an imaging element, at least one blade movable on a moving plane to open and close the opening, and at least one arm connected to the at least one blade. The at least one arm has a plate portion extending along the moving plane, and a shielding wall extending from an edge of the plate portion toward the imaging element perpendicular to the plate portion.

[0025] As a result, even if wear powder or dust is generated at the connection between the blade and the arm, this wear powder or dust can be kept inside the shielding wall extending from the edge of the plate portion of the arm, thereby preventing the wear powder or dust from diffusing outside the arm.

[0026] It is preferable that the at least one arm further has an adhesive layer formed on a surface of the plate portion facing the imaging element. By forming such an adhesive layer, wear powder and dust present in the space inside the shielding wall are adsorbed and captured by the adhesive layer, so that the wear powder and dust in the space inside the shielding wall are effectively prevented from diffusing to the outside of the shielding wall.

[0027] The at least one arm may be made of metal and may be formed by drawing or forging.

[0028] According to a second aspect of the present invention, there is provided an imaging device capable of suppressing adhesion of wear powder generated at a connection between a blade and an arm to an imaging element, the imaging device comprising the above-mentioned blade drive device and an imaging element disposed on a surface on which an image is formed by light transmitted through the opening in the base plate of the blade drive device.

[0029] According to this configuration, the wear powder generated at the connection between the blade and the arm is prevented from diffusing within the blade drive device as described above, and the wear powder is prevented from adhering to the imaging element in the camera, thereby preventing a decrease in the quality of the image captured by the imaging device.

[0030] 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]

[0031] 1. Blade drive device 10 Main plate 20 Cover plate 31~34 Leading wing 35~38 Rear wing 41,42 Leading blade arm 43,44 Rear wing arm 51~58 Connection part 61~68 Connection part 71,72,81,82 Support shaft 73,83 Drive pin 100,200 plate part 110,210 Shielding wall 120,220 Rivet holes 130,140,230 Shaft hole 150,250 Adhesive layer S Exposure aperture

Claims

1. a base plate having an opening formed therein for guiding light from a subject to an image sensor; at least one blade movable in a plane of movement to open and close the opening; At least one arm rotatably connected to the at least one blade via a connector, a plate portion extending along the movement plane and to which the connecting portion is attached; a shielding wall extending from an edge of the plate portion perpendicular to the plate portion so as to surround the connecting portion; At least one arm having A blade drive device comprising:

2. The blade drive device according to claim 1 , wherein the at least one arm further has an adhesive layer formed on a surface of the plate portion on a side on which the shielding wall extends.

3. The blade drive device according to claim 1 or 2, wherein the at least one arm is made of metal.

4. A method for manufacturing an arm, comprising forming at least one arm described in any one of claims 1 to 3 by drawing or forging.

5. The blade drive device according to any one of claims 1 to 3, an imaging element disposed on a surface on which an image is formed by light transmitted through the opening of the base plate of the blade drive device; An imaging device comprising:

Images