JP2020034712A - Focal plane shutter, and imaging apparatus - Google Patents

Abstract

To provide a focal-plane shutter having a configuration capable of reducing dust generation and scattering by reducing the friction during shutter blade operation.SOLUTION: The focal plane shutter includes: a base plate and an auxiliary base plate each having an aperture; an intermediate plate having an aperture, which is arranged between the base plate and the auxiliary base plate; a first blade arranged between the base plate and the intermediate plate; and a second blade arranged between the auxiliary base plate and the intermediate plate. The intermediate plate formed in a movement area of the first blade is configured to have a first convex portion in contact with the first blade, and a second convex portion in contact with the second blade formed in a movement area of the second blade.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 a focal plane shutter that exposes an image sensor by opening and closing an opening (image frame) by a group of blades, a driving mechanism drives a group of blades arranged in a blade chamber formed between a main plate, an intermediate plate, and an auxiliary main plate. The exposure is performed by changing the open / closed state of the opening by driving. In such a focal plane shutter, when the blade group slides on the main plate, the auxiliary main plate, and the intermediate plate during operation, friction occurs, and dust such as abrasion powder is generated from these components. When these dusts adhere to the image sensor, the image quality of the captured image is degraded, and if they accumulate in the blade chamber, they may hinder the operation of the blade group. Therefore, in order to reduce such dust, various configurations for reducing the friction between the blade group and the ground plate, the auxiliary ground plate, and the intermediate plate have been adopted. For example, in Patent Literature 1, the head 9a of the swaging shaft 9 of the arms 3 and 4 can slide with the ridge 1k on the blade chamber side of the shutter base plate 1 formed along the operating path of the head 9a. Such a configuration is disclosed. Patent Document 2 discloses a configuration in which a convex portion 2c is provided on the aperture blade 2.

JP 2001-281728 A JP 2003-177444 A

  In recent years, the resolution of an image sensor has been increased, and an image pickup apparatus that takes an image with excellent image quality has been demanded. To further reduce a decrease in image quality caused by dust generated by friction adhering to the image sensor. Is required. In addition, there is a demand for an imaging device with higher durability than before. On the other hand, the conventional structure for reducing dust may not be sufficient.

  The present invention employs 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 to facilitate understanding of the invention, but each component of the present invention is not limited to those added, and the present invention is not limited thereto. It should be widely interpreted to a technically understandable range by a trader.

The first means of the present invention is:
A base plate (1) and an auxiliary base plate (2) each having an opening (1a, 2a);
An intermediate plate (3) having an opening disposed between the base plate and the auxiliary base plate;
A first blade (5) disposed between the main plate and the intermediate plate;
A second blade (4) disposed between the auxiliary base plate and the intermediate plate,
The intermediate plate (3)
A first protrusion (3d) formed in a moving area of the first blade (5) and in contact with the first blade;
A second convex portion (3b, 3c) formed in a moving area of the second blade (4) and in contact with the second blade.
It is a focal plane shutter.

  According to the focal plane shutter having the above configuration, the first blade and the second blade operate while sliding on the first convex portion and the second convex portion, so that the friction between the blade and the intermediate plate can be reduced. Accordingly, it is possible to suppress the generation of dust such as abrasion powder, and to suppress the abrasion powder from scattering and adhering to the imaging element or accumulating in the blade chamber or the like. As a result, it is possible to configure a shutter that prevents deterioration in image quality and improves durability. Further, since the first convex portion and the second convex portion can limit the fluttering range of the blade in the thickness direction, it is possible to effectively reduce friction and reduce noise during operation.

  Also, since both the first convex portion and the second convex portion are formed on the intermediate plate, the manufacturing cost of the shutter can be reduced as compared with a configuration in which the convex portions are formed on the base plate and the auxiliary base plate, for example. .

In the focal plane shutter, preferably,
A lubricant is disposed on the first convex portion and the second convex portion.

  According to the focal plane shutter having the above configuration, the friction between the blade and the intermediate plate can be further reduced, and the generation of dust such as abrasion powder can be more effectively suppressed. In addition, since it is sufficient to arrange the lubricant only in the first convex portion and the second convex portion, the amount of the lubricant used can be reduced. In addition, it is possible to improve maintainability.

In the focal plane shutter, preferably,
A first blade holding plate (34) arranged so as to overlap an end of the first blade;
The first blade holding plate is formed along a movement trajectory of the first blade and has a third convex portion (34a) in contact with the first blade.

  According to the focal plane shutter having the above configuration, the sliding portion between the first blade holding plate and the first blade during operation is limited to the third convex portion, so that the first blade and the first blade holding plate are operated. Can be reduced. Thereby, the generation of dust such as abrasion powder can be more effectively suppressed. Further, since the third convex portion can restrict the fluttering range of the blade in the thickness direction, it is possible to effectively reduce friction and reduce noise during operation.

In the focal plane shutter, preferably,
A second blade holding plate (33) arranged so as to overlap an end of the second blade;
The second blade holding plate is formed along a movement trajectory of the second blade, and has a fourth convex portion (33a, 33b) in contact with the second blade.

  According to the focal plane shutter having the above configuration, the sliding portion between the second blade holding plate and the second blade at the time of operation is limited to the portion of the fourth convex portion, so that the second blade and the second blade holding plate are operated. Can be reduced. Thereby, the generation of dust such as abrasion powder can be more effectively suppressed. In addition, since the fourth convex portion can limit the fluttering range of the blade in the thickness direction, it is possible to effectively reduce friction and reduce noise during operation.

  Any of the focal plane shutters is suitably applied to an imaging device such as a camera.

  According to the above-described imaging apparatus, it is possible to adopt a configuration in which dust such as abrasion powder is prevented from accumulating on the blade chamber or the driving unit or adhering to the imaging element. As a result, it is possible to prevent a deterioration in the quality of an image captured by the imaging device while preventing an operation failure caused by the wear powder.

FIG. 1 is a plan view of a focal plane shutter before a blade travels in the first embodiment. FIG. 2 is a plan view of the focal plane shutter after the blade travels in the first embodiment. FIG. 3 is a sectional view of the focal plane shutter according to the first embodiment. FIG. 4 is a plan view of the focal plane shutter before the blade travels in the second embodiment. FIG. 5 is a plan view of the focal plane shutter after the blade travels in the second embodiment. FIG. 6 is a sectional view of the focal plane shutter according to the second embodiment.

  The focal plane shutter of the present invention is used for an imaging device such as a digital camera, and reduces the friction at the time of operating the blades of the focal plane shutter and suppresses the generation of dust such as abrasion powder. One of the features is that a projection is provided on at least one of the plate and the blade holding plate.

An embodiment 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 do not limit the technical scope of the present invention. In the drawings, the same components are denoted by the same reference numerals, and description thereof may be omitted.
1. Embodiment 1
2. Embodiment 2
3. 3. Features of the present invention Supplementary information

<1. First Embodiment>
First, Embodiment 1 of the present invention will be specifically described. The main feature of this embodiment is that the intermediate plate has a convex portion. 1 and 2 are plan views of the focal plane shutter according to the present embodiment. FIG. 1 shows a state before the blade travels, and FIG. 2 shows a state after the blade travels. FIG. 3 is a cross-sectional view of the vicinity of the blade chamber of the focal plane shutter according to the present embodiment.

  As shown in FIGS. 1 and 2, the focal plane shutter according to the present embodiment includes a base plate 1, an auxiliary base plate 2, an intermediate plate 3, a blade holding plate 31 for a front blade, a blade holding plate 32 for a rear blade, and a front blade group. 4, a rear blade group 5, a front blade main arm 61, a front blade sub arm 62, a rear blade main arm 71, a rear blade sub arm 72, and a drive unit 8. As shown in the cross-sectional view of FIG. 3, these configurations include the auxiliary base plate 2, the blade holding plate 31 for the front blade, the front blade group 4, the intermediate plate 3, the rear blade group 5, and the blade holding plate 32 for the rear blade. , And the base plate 1 are stacked and arranged in this order. In the present specification, the leading blade group 4 and the trailing blade group 5 may be collectively referred to as a “wing group” or a “wing”. The main arm 61 for the front blade and the main arm 71 for the rear blade may be collectively referred to as a “main arm”. The leading arm 62 for the leading blade and the trailing arm 72 for the trailing blade may be collectively referred to as a "slave arm". Further, the main arm and the slave arm may be collectively referred to as “arm”. The blade holding plate 31 for the front blade and the blade holding plate 32 for the rear blade may be collectively referred to as a “blade holding plate”.

<Main 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 FIGS. 1 and 2, a driving unit 8 (shown in FIG. 1) that drives the leading blade group 4 and the trailing blade group 5 is provided outside a blade chamber (described later) on the side (left side of the drawing) of the opening 1 a of the main plate 1. (Omitted). The drive unit 8 has the same configuration as that of the related art including a motor or an electromagnetic actuator. The drive section 8 has drive pins 81 and 82 that output power and are connected to the main arm 61 for the front blade and the main arm 71 for the rear blade, and transmit power to the blades via these main arms. The description of the specific configuration of the driving unit 8 is omitted.

  The main plate 1 rotatably supports the main arm 61 for the front blade and the sub arm 62 for the front blade in the blade chamber formed between the auxiliary main plate 2 and the main arm 61 for the front blade and the sub arm for the front blade. It has a rotation axis serving as the center of rotation of 62. The main plate 1 rotatably supports the main arm 71 for the rear blade and the slave arm 72 for the rear blade in the blade chamber, and rotates as the center of the rotation of the main arm 71 for the rear blade and the slave arm 72 for the rear blade. Has an axis. These rotating shafts have, for example, a shaft-like configuration erected on the main plate 1. Through holes are formed in the base plate 1 along the movement trajectories of the drive pins 81 and 82 that output the drive force from the drive unit 8. Each of these through holes is a long hole extending in an arc shape around the rotation axis, and penetrates through the main plate 1. A drive pin 81 for the front blade group 4 and a drive pin 82 for the rear blade group 5 are inserted into the through holes, respectively.

<Auxiliary base plate 2>
The auxiliary base plate 2 is attached to the base plate 1 at a position facing the base plate 1 with a predetermined space therebetween. The space formed between the auxiliary main plate 2 and the main plate 1 serves as a blade chamber for accommodating the front blade group 4 and the rear blade group 5. A space formed by the main plate 1 and the auxiliary main plate 2, or a space formed by the main plate 1, the auxiliary main plate 2, and the intermediate plate 3 may be referred to as a "blade chamber".

  In the blade chamber between the main plate 1 and the auxiliary main plate 2, the intermediate plate 3, the front blade group 4, the rear blade group 5, the main arm 61 for the front blade, the slave arm 62 for the front blade, the main arm 71 for the rear blade, A trailing arm 72 for the rear blade, a blade holding plate 31 for the front blade, a blade holding plate 32 for the rear blade, and the like are arranged.

  The auxiliary base plate 2 has an opening 2 a formed at a position facing the opening 1 a of the base plate 1. The opening 2a has a rectangular shape similar to the opening 1a, but does not have to be a perfect rectangle, and may have any shape other than a rectangle.

  The auxiliary base plate 2 is arranged at a position close to an image pickup device (not shown) in an image pickup apparatus equipped with a focal plane shutter. However, the orientations of the base plate 1 and the auxiliary base plate 2 with respect to the position of the image sensor can be arbitrarily changed. Note that the auxiliary base plate 2 may be referred to as a “cover plate”.

<Intermediate plate 3>
The intermediate plate 3 is arranged between the main plate 1 and the auxiliary main plate 2. The intermediate plate 3 is formed of metal or resin. The rear blade group 5, the main arm 71 for the rear blade, and the slave arm 72 for the rear blade are accommodated between the intermediate plate 3 and the main plate 1. The front blade group 4, the main arm 61 for the front blade, and the slave arm 62 for the front blade are accommodated between the intermediate plate 3 and the auxiliary base plate 2. The intermediate plate 3 has a rectangular opening 3a at a position facing the opening 1a of the base plate 1 and the opening 2a of the auxiliary base plate 2. Like the openings 1a and 2a, the opening 3a of the intermediate plate 3 may have any shape other than a rectangular shape.

  As shown mainly in FIGS. 1 and 2, the intermediate plate 3 has convex portions 3 b and 3 c formed along an operation trajectory in the movement region of the front blade group 4 and a movement region of the rear blade group 5. Has a convex portion 3d formed along the operation locus. As shown in FIG. 3, the protrusion 3 b is a protrusion protruding from the intermediate plate 3 toward the front blade group 4 side. The protrusion 3c is the same as the protrusion 3b. The protrusion 3d is a protrusion that protrudes from the intermediate plate 3 toward the rear blade group 5 side. The projections 3b to 3d function as rails that come into contact with the front blade group 4 and the rear blade group 5 when the front blade group 4 and the rear blade group 5 are operated with the operation of the shutter. The protrusions 3b to 3d may be always in contact with each other when the front blade group 4 and the rear blade group 5 are operated, or may be arranged so as to be in contact with or separate from each other.

  In the present embodiment, the convex portions 3b to 3d illustrate a configuration formed in a rail shape along the operation locus of each of the blade groups 4 and 5, but the top portions of the convex portions 3b to 3d and each The interval between the blade groups 4 and 5 is formed such that the center portion is narrower than both end portions in the operating direction of each blade group 4 and 5. Thus, when the blade groups 4 and 5 are operated, the blade members 41 to 44 and the blade members 51 to 54 can smoothly come into contact with the protrusions 3b to 3d.

  The lubricating agent is arranged on at least the protruding portions 3 b to 3 d at positions where they contact the front blade group 4 and the rear blade group 5. The lubricant is, for example, a fluorine-based, epoxy-based, phenol-based, or graphite-based lubricant, and is disposed, for example, by painting. It is preferable that the lubricant be disposed only on the protrusions 3b to 3d because the amount of the lubricant used is limited. On the other hand, when the lubricant is applied to the entire intermediate plate 3 including the protrusions 3b to 3d, it is preferable in that the man-hour for lubricant application may be reduced.

  In the present embodiment, the intermediate plate 3 has two protrusions 3b and 3c protruding toward the front blade group 4, but the number of protrusions may be one. The intermediate plate 3 has one convex portion 3d protruding toward the rear blade group 5, but the number of convex portions may be two or more. In other words, the number of these convex portions is arbitrary as long as they are formed along the operation trajectory in the movement area of the front blade group 4 and the rear blade group 5.

  Further, the convex portions 3b to 3d are formed along the operation trajectory of the end of each blade group on the side opposite to the side connected to the arm. However, the present invention is not limited to this. A convex portion may be formed at an arbitrary position in the operation area of the group.

  Further, the shape of the protrusions 3b to 3d is a rail-like configuration, but is not limited to this, and the protrusions may be conical. Further, in this case, the distance between the top of each of the plurality of conical convex portions and each of the blade groups 4 and 5 is more than that of the plurality of convex portions at both end regions in the operation direction of each of the blade groups 4 and 5 in the central region. The protrusion may be formed so as to be narrower. With such a configuration, when the blade groups 4 and 5 are operated, the blade members 41 to 44 and the blade members 51 to 54 can smoothly contact the plurality of convex portions.

<First wing group 4>
The front blade group 4 is disposed in the blade chamber between the auxiliary main plate 2 and the intermediate plate 3 as described above. The front blade group 4 is composed of a plurality of plate-shaped blade members 41 to 44, and is connected to the drive unit 8 by a connecting tool such as a rivet, as is well known, at a position (left side in the drawing) where the driving unit 8 is disposed. It is connected to the main arm 61 and the slave arm 62 for the front blade. The front blade group 4 is driven by a front blade drive pin (not shown) via the front blade main arm 61, and covers the exposure opening formed by the openings 1a, 2a, and 3a, and opens the exposure opening. (Open / closed state). The blade members 41 to 44 constituting the front blade group 4 are each formed of a material such as metal such as aluminum, carbon fiber, or resin, but are not limited to these materials.

<Back Wing Group 5>
The rear blade group 5 is disposed in the blade chamber between the main plate 1 and the intermediate plate 3 as described above. The rear blade group 5 is composed of a plurality of plate-shaped blade members 51 to 54, and is connected to the rear blade (at the left side in the drawing) at a position where the driving unit 8 is disposed by a connecting tool such as a rivet, as is well known. It is connected to the main arm 71 and the slave arm 72 for the rear blade. The rear blade group 5 is driven by a rear blade drive pin (not shown) via the rear blade main arm 71, and covers the exposure opening formed by the openings 1a, 2a and 3a, and opens the exposure opening. (Open / closed state). The blade members 51 to 54 constituting the rear blade group 5 are each formed of a material such as metal such as aluminum, carbon fiber, or resin, but are not limited to these materials.

<Arms 61, 62, 71, and 72>
The main arm 61 for the front blade is arranged between the driving pin 81 for the front blade and the front blade group 4, and the driving pin 81 for the front blade is inserted into the hole of the main arm 61 for the front blade to be connected to the front blade group 4. Be linked. The leading blade main arm 61 drives the leading blade group 4 by transmitting the driving force generated by the driving unit 8 to the leading blade group 4 via the leading blade drive pin 81. The leading blade slave arm 62 is connected to the leading blade group 4 as described above. The leading blade slave arm 62 is rotatably connected to the shaft of the main plate 1 on the blade chamber side, similarly to the leading blade main arm 61. The front arm 62 for the front blade receives no driving force directly from the drive unit 8 and operates in accordance with the operation of the main arm 61 for the front blade.

  The rear blade main arm 71 is disposed between the rear blade drive pin 82 and the rear blade group 5, and the rear blade drive pin 82 is inserted into the hole of the rear blade main arm 71 and Be linked. The rear blade main arm 71 drives the rear blade group 5 by transmitting the driving force generated by the driving unit 8 to the rear blade group 5 via the rear blade drive pin 82. The rear arm 72 for the rear blade is connected to the rear blade group 5 as described above. The rear arm 72 for the rear blade is rotatably connected to a shaft of the main plate 1 on the blade chamber side, similarly to the main arm 71 for the rear blade. The rear arm 72 for the rear blade receives no driving force directly from the driving unit 8 and operates in accordance with the operation of the main arm 71 for the rear blade.

<Drive pin>
The front blade drive pin 81 and the rear blade drive pin 82 are respectively connected to the drive unit 8 including an electromagnetic actuator and the like. The driving unit 8 is operated by electric power supplied from the outside, and transmits power to the front blade driving pin and the rear blade driving pin. The front blade drive pin and the rear blade drive pin drive the front blade group 4 and the rear blade group 5 via the front arm main arm 61 and the rear blade main arm 71, respectively, to open and close the opening 1a. Switch. The running operation of the front blade group 4 and the rear blade group 5 is the same as the conventional configuration.

  The drive unit 8 includes, for example, a permanent magnet, a yoke, a coil, a coil spring, and the like, in addition to the front blade drive pin 81 and the rear blade drive pin 82, and is operated by applied power. The drive unit 8 includes a conventionally known electromagnetic actuator or motor.

<Front holding plate 31 for front blade>
The blade holding plate 31 for the front blade is arranged between the front blade group 4 and the auxiliary base plate 2 (see FIG. 3). The front blade holding plate 31 is disposed so as to overlap the movement trajectory of the end of the front blade group 4 opposite to the side connected to the arm (see FIGS. 1 and 2). The blade holding plate 31 for the front blade acts to suppress the flutter of the front blade group 4 in the thickness direction.

<Back blade holding plate 32 for rear blade>
The rear blade holding plate 32 is arranged between the rear blade group 5 and the main plate 1 (see FIG. 3). The rear blade holding plate 32 is disposed so as to overlap the movement trajectory of the end of the rear blade group 5 opposite to the side connected to the arm (see FIGS. 1 and 2). The blade holding plate 32 for the rear blade acts to suppress fluttering of the rear blade group 5 in the thickness direction.

  When the focal plane shutter according to the present embodiment is incorporated in an imaging apparatus, an imaging element is arranged at a position corresponding to the openings 1a to 3a. The imaging element is arranged so as to overlap with the openings 1a to 3a and cover the openings 1a to 3a in plan view as viewed from the optical axis direction. The imaging apparatus including the focal plane shutter of the present embodiment includes a lens barrel holding a lens, a substrate on which an imaging element is mounted, a lens barrel, a focal plane shutter, a case covering the substrate, and the like. .

<2. Embodiment 2>
Next, a second embodiment of the present invention will be specifically described with reference to FIGS. The configuration of this embodiment is different from the configuration of the first embodiment in that instead of providing the intermediate plate 3 with a convex portion, the first blade pressing plate 33 and the rear blade pressing plate 34 are provided with convex portions. And the other configuration is common. Here, only differences from the first embodiment will be described, and description of common points will be omitted.

  4 and 5 are plan views of the focal plane shutter of the present embodiment. FIG. 4 shows a state before the blade travels, and FIG. 5 shows a state after the blade travels. FIG. 6 is a cross-sectional view of the vicinity of the blade chamber of the focal plane shutter according to the present embodiment. 4 to 6 correspond to FIGS. 1 to 3 of the first embodiment.

<Front holding plate 33 for front blade>
The blade holding plate 33 for the front blade is disposed between the front blade group 4 and the auxiliary base plate 2 (see FIG. 6). The blade holding plate 33 for the front blade is arranged so as to overlap the movement trajectory of the end of the front blade group 4 on the side opposite to the side connected to the arm (see FIGS. 4 and 5). The blade holding plate 33 for the front blade acts to suppress the flutter of the front blade group 4 in the thickness direction.

  The blade holding plate 33 for the front blade has protrusions 33a and 33b formed along an operation locus in the movement area of the front blade group 4. As shown in FIG. 6, the protrusion 33 a is a protrusion that protrudes from the blade holding plate 33 for the front blade toward the front blade group 4 side. The protrusion 33b is similar to the protrusion 33a. The protruding portions 33a and 33b function as rails that come into contact with the front blade group 4 when the front blade group 4 operates according to the operation of the shutter. The protrusions 33a and 33b may be always in contact with each other when the front blade group 4 is operated, or may be arranged so as to be in contact with or separate from the other.

  Further, the convex portions 33a and 33b of the present embodiment are formed in a rail shape along the operation locus of the front blade group 4, but the distance between the top of each of the convex portions 33a and 33b and the front blade group 4 is The central portion is formed to be narrower than both ends in the operating direction of the leading blade group 4. Thereby, when the front blade group 4 is operated, the blade members 41 to 44 can smoothly come into contact with the convex portions 33a and 33b.

<Back blade holding plate 34>
The rear blade holding plate 34 has a convex portion 34 a formed along an operation locus in the movement area of the rear blade group 5. As shown in FIG. 6, the convex portion 34 a is a convex portion that protrudes from the rear blade holding plate 34 toward the rear blade group 5. The convex portion 34a functions as a rail that comes into contact with the rear blade group 5 when the rear blade group 5 operates according to the operation of the shutter. In addition, the convex portion 34a may be always in contact when the rear blade group 5 is operated, or may be arranged so as to be in contact with or separate from the rear blade group 5.

The convex portion 34a of the present embodiment is formed in a rail shape along the operation locus of the rear blade group 5, but the distance between the top of the convex portion 34a and the rear blade group 5 is The central portion is formed to be narrower than both end portions in the operation direction. Thereby, when the rear blade group 4 is operated, the blade members 51 to 54 can smoothly come into contact with the convex portions 34a.

  The lubricating agent is disposed on at least the protrusions 33a, 33b, and 34a at positions where they contact the front blade group 4 and the rear blade group 5. The lubricant is, for example, a fluorine-based, epoxy-based, phenol-based, or graphite-based lubricant, and is disposed, for example, by painting. It is preferable that the lubricant be disposed only on the protrusions 33a, 33b, and 34a because the amount of the lubricant used is limited. On the other hand, when applying the lubricant to the entirety of the front blade holding plate 33 and the rear blade holding plate 34 including the protrusions 33a, 33b, and 34a, the number of steps of lubricant application may be reduced. It is preferred in that respect.

  In the present embodiment, the blade holding plate 33 for the front blade has two protrusions 33a and 33b projecting toward the front blade group 4, but the number of protrusions may be one. In addition, the rear blade holding plate 34 has one convex portion 34a protruding toward the rear blade group 5, but the number of the convex portions may be two or more. That is, if formed along the operation trajectory in the movement area of the leading blade group 4 and the trailing blade group 5, the number of protrusions respectively formed on the leading blade pressing plate 33 and the trailing blade pressing plate 34 is increased. Is optional.

  In addition, the protrusions 33a, 33b, and 34a are formed along the operation trajectory of the end of each blade group on the side opposite to the side connected to the arm of each blade group, but the present invention is not limited to this. However, the location where these convex portions are formed may be arbitrarily determined as long as it is within the operating region of each blade group in each of the blade holding plates 33 and 34.

  In addition, the protrusions 33a, 33b, and 34a have a rail-like configuration. However, the present invention is not limited to this, and each protrusion may have another shape such as a conical shape. Further, in this case, the interval between the top of each convex portion such as a plurality of cones and each of the blade groups 4 and 5 is more than the number of the convex portions at both end regions in the operation direction of each of the blade groups 4 and 5 in the central region. Is preferably formed so that the convex portion of the substrate becomes narrower. Thus, when the blade groups 4 and 5 are operated, the blade members 41 to 44 and the blade members 51 to 54 can smoothly contact the plurality of convex portions.

<3. Features of the present invention>
The present invention whose specific examples have been described as the first and second embodiments have the following features. Note that the first embodiment and the second embodiment can be configured to be partially or wholly combined.

  The focal plane shutter according to the first embodiment is configured such that the intermediate plate 3 has the convex portions 3b and 3c protruding toward the front blade group 4 side and the convex portion 3d protruding toward the rear blade group 5 side. Therefore, at the time of operation, the front blade group 4 slides on the convex portions 3b and 3c, and the rear blade group 5 slides on the convex portion 3d, so that the friction between the blade and the intermediate plate 3 can be reduced. Thus, it is possible to suppress the generation of dust such as abrasion powder due to friction, and to prevent the abrasion powder from scattering and adhering to the image sensor or being deposited on the blade chamber or the like. As a result, it is possible to configure a shutter that prevents deterioration in image quality and improves durability. In addition, the convex portions 3b to 3d can limit the fluttering range of the blade in the thickness direction, so that it is possible to effectively reduce friction, reduce noise during operation, and the like.

  Further, since both the first convex portion and the second convex portion are formed on the intermediate plate, the manufacturing cost of the shutter can be reduced as compared with a configuration in which the convex portions are formed on the base plate and the auxiliary base plate, for example. Become.

  In the above configuration, it is preferable that the protrusions 3b to 3d have a configuration in which a lubricant is disposed. With such a configuration, the friction between the blade and the intermediate plate 3 can be further reduced, and the generation of dust such as abrasion powder can be more effectively suppressed. Further, when the lubricant is arranged only on the protrusions 3b to 3d, the amount of the lubricant used can be reduced. In addition, it is possible to improve maintainability.

  In the configuration in which the focal plane shutter according to the second embodiment is combined with the focal plane shutter according to the first embodiment, the projection 33a, 33b, and 34a are provided on the front blade pressing plate 33 and the rear blade pressing plate 34. I have. In this configuration, this reduces the friction between the blade and the blade holding plate. Thereby, the generation of dust such as abrasion powder can be more effectively suppressed. In addition, since the convex portions 33a, 33b, and 34a can limit the range of fluttering of the blade in the thickness direction, it is possible to effectively reduce friction, reduce noise during operation, and the like.

  In addition, even if the convex portions 33a, 33b, and 34a are arranged on only one of the front blade holding plate 33 and the rear blade holding plate 34, a certain effect can be obtained in reducing friction. In particular, if any one of the protrusions 33a, 33b, and 34a is arranged on the side of the front blade group 4 and the rear blade group 5 that is close to the image sensor, it is possible to effectively prevent abrasion powder from adhering to the image sensor. It is preferable in that it can be effectively suppressed.

  In the imaging device including the focal plane shutter according to any one of the embodiments of the present invention, it is possible to prevent dust such as abrasion powder from accumulating on the blade chamber or the driving unit or adhering to the imaging element. It can be configured as follows. Accordingly, a configuration is possible in which a deterioration in the quality of an image captured by the imaging device can be suppressed while preventing an operation failure due to the abrasion powder.

<4. Supplementary items>
The specific description of the embodiment of the present invention has been given above. The above description is merely a specific example, and the scope of the present invention is not limited to this embodiment but is widely interpreted to a range that can be understood by those skilled in the art.

  Further, in the embodiment, the front blade group 4 and the rear blade group 5 provided in the focal plane shutter have been described as being configured to have a plurality of blade members, respectively. However, the front blade group 4 and the rear blade group 5 each include one sheet. May be provided.

  Further, in the embodiment, the focal plane shutter including the front blade group 4 and the rear blade group 5 has been described. However, a configuration including only one of the front blade group 4 and the rear blade group 5 may be adopted. In this case, in the focal plane shutter of the embodiment, the configuration example including the intermediate plate 3 has been described, but a configuration not including the intermediate plate 3 may be adopted.

  INDUSTRIAL APPLICABILITY The present invention is suitably applied as a focal plane shutter of an imaging device such as a digital camera.

DESCRIPTION OF SYMBOLS 1 ... Ground plate 1a ... Opening part 2 ... Auxiliary base plate 2a ... Opening part 3 ... Intermediate plate 3a ... Opening parts 3b-3d ... Convex part 31, 33 ... Blade holding plate 33a, 33b ... Convex part 32, 34 ... Rear Blade holding plate 34a: convex portion 4: front blade group 41-44: blade member 5: rear blade group 51-54: blade member 61: main arm for front blade 62: slave arm 71 for front blade: rear blade Main arm 72: Rear arm for trailing blade 8: Drive unit 81, 82: Drive pin

Claims (5)

A base plate and an auxiliary base plate each having an opening,
An intermediate plate having an opening disposed between the main plate and the auxiliary main plate,
A first blade disposed between the main plate and the intermediate plate;
A second blade disposed between the auxiliary base plate and the intermediate plate,
The intermediate plate,
A first convex portion formed in a moving area of the first blade and in contact with the first blade;
A second convex portion formed in a moving area of the second blade and in contact with the second blade.
Focal plane shutter. A lubricant is disposed on the first convex portion and the second convex portion.
The focal plane shutter according to claim 1. A first blade holding plate disposed so as to overlap an end of the first blade;
The first blade holding plate is formed along a movement trajectory of the first blade, and has a third convex portion in contact with the first blade.
The focal plane shutter according to claim 1. A second blade holding plate disposed so as to overlap an end of the second blade;
The second blade holding plate is formed along a movement trajectory of the second blade, and has a fourth convex portion in contact with the second blade.
The focal plane shutter according to claim 3.   An imaging apparatus comprising the focal plane shutter according to any one of claims 1 to 4.

Images