JP2008242183A - Arm member, shutter device, and arm member manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shutter device having high durability and to provide an arm member manufacturing method. <P>SOLUTION: The shutter device includes: a shutter base plate 30 having an aperture part 36 and a groove 37; a driving pin 40 that moves along the groove 37; the arm members 12 and 22 that relatively move with the shutter base plate 30 through the driving pin 40; and shutter blades 11 and 21 that are attached to the arm members 12 and 22, so as to open/close the aperture part 36. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an arm member, a shutter device, and a method for manufacturing the arm member.

  2. Description of the Related Art Conventionally, a focal plane shutter, which is one of shutter devices, has a main arm and a secondary arm that are rotatably connected to a shutter substrate and a plurality of divided blades to form a parallel link. The main arm and the shutter substrate are pivotally supported by a drive pin that engages with a drive pin hole formed in the main arm so that the main arm can rotate about a rotation axis. Each arm and each divided blade are pivotally supported by a connecting pin. With such a parallel link configuration, shutter release is performed by repeatedly performing an open state where each divided blade is folded outside the exposure window of the shutter substrate and a shielding state covering the exposure window.

  However, the focal plane shutter is also used in digital cameras that have been developed in recent years, and there is a current situation that the user has been released from the problem of film consumption and the number of shutter releases has inevitably increased. As the number of shutter releases increases, the friction between the drive pin and the drive pin hole of the arm progresses, and there is a risk that the shutter accuracy will be reduced or wear powder generated by the friction will accumulate on the image sensor such as a CCD. was there.

Therefore, conventionally, there has been a proposal for improving the wear resistance of the shutter device by defining the material and hardness of the connecting pin (also referred to as a caulking pin) and the arm.
JP 2004-325553 A

  However, the conventional shutter device provided with the arm member has a problem that durability is not sufficient.

  Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide a highly durable arm member, a shutter device, and a method for manufacturing the arm member.

  According to the first aspect of the present invention, in the arm member, the first layer (122) formed by plating on the surface of the base material (121), the hardness is higher than the first layer, and the first layer And a second layer (123) formed by plating on the surface.

  According to the invention described in claim 6, in the shutter device, the shutter substrate (30) having the opening (36) and the groove (37), the drive pin (40) moving along the groove, and the The arm member (12, 13, 22, 23) according to any one of claims 1 to 5, which moves relative to the shutter base via a drive pin, and the opening attached to the arm member. And shutter blades (11, 21) for opening and closing.

  According to invention of Claim 7, in the manufacturing method of an arm member, the process of performing a plating process on the surface of a base material (121) to form the first layer (122), and the surface of the first layer And performing a plating treatment to form a second layer (123) having a higher hardness than the first layer.

  According to the present invention, it is possible to provide a highly durable arm member and a shutter device including the arm member.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a single-lens reflex digital camera according to an embodiment of the present invention. In the single-lens reflex digital camera 1, a photographing lens 3 is attached to the camera body 2 in a replaceable manner. The camera body 2 includes a quick return mirror 4, a pentaprism 5, an eyepiece lens 6, a sub mirror 7, a focus detection device 8, an image sensor 9, and a shutter device 100. The shutter device 100 is called a focal plane shutter, and is disposed in the vicinity of the image sensor 9. The photographing lens 3 has a photographing optical system including a lens, a diaphragm, and the like in its barrel.

  The light beam L from the subject that has passed through the photographing lens 3 is reflected upward in the figure by the quick return mirror 4 and reaches the eyes of the photographer via the pentaprism 5 and the eyepiece 6. On the other hand, a part of the light beam L passes through the quick return mirror 4, is reflected downward in the figure by the sub mirror 7, and is guided to the focus detection device 8. When a release button (not shown) is pressed, the shutter device 100 starts operating, and the quick return mirror 4 and the sub mirror 7 are flipped up and retracted from the photographing optical path. The light beam L that has passed through the photographing lens 3 is guided to the image sensor 9, and a subject image is formed on the light receiving surface of the image sensor 9.

  FIG. 2 is an exploded perspective view of the shutter device 100 according to the embodiment of the present invention. FIG. 3 is a front view of the shutter charged. FIG. 4 is a front view showing a state in which the exposure operation is completed by pressing the release button.

  The shutter device 100 includes a front curtain 10, a rear curtain 20, and a shutter substrate 30. The shutter substrate 30 and the front curtain 10 are connected by a driving pin 40, a rotating shaft 50, and a connecting pin (not shown) described later (see FIGS. 3 and 4). Further, the drive pin 40, the rotation shaft 50, and the connection pin are also used to connect the shutter substrate 30 and the rear curtain 20 (see FIGS. 3 and 4).

  The shutter substrate 30 includes a first substrate 31 located on the photographing lens 3 side and a second substrate 32 located on the imaging element 9 side. In addition, the shutter device 100 includes a light shielding plate 33, an intermediate plate 34, a spacer 35, and the like disposed between the first substrate 31 and the second substrate 32. The shutter substrate 30 is formed in substantially the same shape as the image sensor 9 and has an opening 36 through which the light beam L is transmitted at a substantially central portion. Further, the shutter substrate 30 has two arc grooves 37 penetrating the shutter substrate 30 so as to be arranged vertically on the side of the opening 36. Although the arc groove 37 of the present embodiment penetrates the shutter substrate 30 as long as the drive pin 40 can move along the inside as described later, the arc groove 37 does not penetrate the shutter substrate 30. It may be a thing.

  The front curtain 10 has four light-shielding blades (shutter blades) 11, a front curtain main arm 12, and a front curtain slave arm 13. The front curtain main arm 12 is formed with a bearing hole 14 through which a rotation shaft 50 that rotatably connects the shutter substrate 30 and the front curtain main arm 12 is formed. The front curtain main arm 12 is formed with a drive pin hole 15 through which the drive pin 40 that moves along the circular arc groove 37 while supporting the front curtain main arm 12 is passed. Furthermore, the front curtain main arm 12 is formed with four connection holes 16 for attaching the light shielding blades 11 with connection pins. Similarly, the front curtain slave arm 13 is formed with a bearing hole 14 and four connection holes 16. The front curtain main arm 12 and the front curtain slave arm 13 are connected to the light shielding blade 11 by fitting the coupling pins into the coupling holes 16 and then crimping the connection pins to the four light shielding blades 11. . The connecting pin is also called a caulking pin.

  The rear curtain 20 includes four light shielding blades (shutter blades) 21, a rear curtain main arm 22, and a rear curtain slave arm 23. Similar to the front curtain 10, the rear curtain main arm 22 is formed with a bearing hole 24 through which a rotation shaft 50 that rotatably connects the shutter substrate 30 and the rear curtain main arm 22 is formed. The rear curtain main arm 22 is formed with a drive pin hole 25 through which the drive pin 40 that moves along the arc groove 37 while supporting the rear curtain main arm 22 passes. Further, the rear curtain main arm 22 is formed with four connecting holes 26 for attaching the light shielding blades 21 with connecting pins. Similarly, the rear curtain follower arm 23 is formed with a bearing hole 24 and four connection holes 26. Here, the front curtain main arm 12, the front curtain secondary arm 13, the rear curtain primary arm 22, and the rear curtain secondary arm 23 are collectively referred to as arm members.

  In FIG. 3, the opening 36 formed in the second substrate 32 is covered with the four light shielding blades 11 of the front curtain 10, and the light shielding blade 21 of the rear curtain 20 overlaps above the opening 36. Are in an open state in which the opening 36 is opened. That is, the front curtain 10 is shielded and the rear curtain 20 is open, thereby preventing exposure.

  In FIG. 4, the light shielding blade 11 of the front curtain 10 is in an open state where it overlaps below the opening 36 and opens the opening 36, and is formed on the first substrate 31 by the four light shielding blades 21 of the rear curtain 20. It is in the shielding state which covers the opened opening 36. That is, the front curtain 10 is in the open state and the rear curtain 20 is in the blocked state, thereby preventing exposure.

  The rotation shaft 50 is implanted in the shutter substrate 30 and supports the front curtain main arm 12, the rear curtain main arm 22, the front curtain secondary arm 13 and the rear curtain secondary arm 23 so as to be rotatable, and a parallel link mechanism. Configure. The drive pin 40 is connected to a drive mechanism (not shown), and moves along the arc groove 37 in response to a signal from the release button. When the drive pin 40 moves along the arc groove 37, it moves in an arc around the rotation shaft 50, and according to the movement, the front curtain main arm 12 and the front curtain sub arm 13 or the rear curtain main arm 22 and the rear curtain subordinate. The arm 23 is moved relative to the shutter substrate 30 so that the front curtain 10 or the rear curtain 20 travels (exposure operation).

  The shutter operation from the shutter charge state of FIG. 3 to the exposure operation end state of FIG. 4 is performed in the following order. First, when the release button is pressed, the light-shielding blade 11 travels from the top to the bottom of the opening 36 by the rotation of the leading curtain slave arm 13 and the leading curtain main arm 12 to open the opening 36. When the opening 36 is opened, the light beam L from the photographing lens 3 is guided to the image sensor 9 and exposure is started. When a certain period of time has elapsed after the start of exposure, the light-shielding blade 21 that overlapped above the opening 36 is unfolded while starting to travel and covers the opening 36 due to the rotation of the rear curtain follower arm 23 and the rear curtain main arm 22. To go.

  The light-shielding blade 21 suddenly loses kinetic energy immediately before the end of traveling because the driving pin 40 collides with the brake member 38 and the rotation of the front curtain main arm 12 and the rear curtain main arm 22 stops suddenly. To do. The exposure operation ends when the light shielding blade 21 completely blocks the opening 36.

  FIG. 5 is a partial cross-sectional view schematically showing the front curtain main arm 12 of the shutter device 100 according to the embodiment of the present invention. The front curtain main arm 12 is formed of a base material 121 using titanium, a first layer 122 formed on the surface of the base material 121 by electro nickel plating, and an electroless nickel plating on the surface of the first layer 122. A second layer 123. As shown in the figure, a first layer 122 and a second layer 123 are also formed on the inner peripheral surface of the drive pin hole 15.

  The base material 121 is formed mainly of a metal material with a thickness of about 150 μm. Examples of the metal material include titanium, a titanium alloy, aluminum, and an aluminum alloy, and at least one of them may be a main material. The hardness of the base material 121 is preferably higher from the viewpoint of the durability of the leading curtain main arm 12, but in the present embodiment, the Vickers hardness may be about Hv150.

  The first layer 122 is formed on the entire surface of the substrate 121 with a thickness of about 3 μm (film thickness variation ± 1 μm or less). The hardness of the first layer 122 is higher than the hardness of the base material 121 and is about Hv 150 to 450, improving the toughness of the leading curtain main arm 12. Although there is no restriction | limiting in particular in the material of the 1st layer 122, Nickel is preferable from viewpoints, such as adhesiveness with the base material 121, slidability with the drive pin 40, and the convenience of a blackening process. The method for forming the first layer 122 is not particularly limited, but is preferably formed by electroplating so that the hardness does not change during the heat treatment for forming the second layer 123 described later.

  The second layer 123 is formed on the entire surface of the first layer 122 with a thickness of about 12 μm (thickness variation ± 2 μm or less). There are no particular restrictions on the material of the second layer, but from the standpoint of adhesion to the upper and lower layers (first layer 122 in this embodiment), slidability with the drive pin 40, convenience of the blackening process, and the like. To nickel are preferred. The hardness of the second layer 123 is higher than the hardness of the first layer 122, and if the Hv is about 450 to 800, the strength of the leading curtain main arm 12 can be sufficiently improved. Further, the hardness of the second layer 123 is preferably about Hv 600 to 750 Hv for the reason of improving wearability. The method for forming the second layer 123 is not particularly limited, but when nickel is used as the material, it is formed by performing heat treatment (detailed later) after forming the film by electroless nickel plating in order to improve the hardness. Is preferred.

  Here, the hardness of the first layer 122 and the second layer 123 will be described. The hardness of the second layer 123 is 1.0 to 5.33 times the hardness of the first layer 122. Moreover, 1.5 to 2.0 times are preferable and 1.8 to 2.0 times are more preferable for the reason of abrasion resistance improvement.

  The first layer 122 and the second layer 123 may be formed at least in the periphery of the drive pin hole 15 from the viewpoint of withstanding friction and impact with the drive pin 40, but over the entire area of the front curtain main arm 12. In order to prevent breakage, it is preferable to form over the entire surface of the substrate 121. In addition, an intermediate layer other than the first layer 122 and the second layer 123 may be formed on the surface of the substrate 121. Further, the configuration of the leading curtain main arm 12 has been described, but the same applies to the trailing curtain main arm 22. The front curtain follower arm 13 and the rear curtain follower arm 23 may have the same configuration in order to prevent the arm member from being damaged by friction or impact force generated around the bearing hole 14 or the connection hole 16. Good.

  Further, according to the arm member in the present embodiment, the first layer 122 and the second layer 123 having higher hardness are formed on the surface of the base material 121, so that the toughness of the leading curtain main arm 12 is increased by the first layer 122. In addition, the strength of the leading curtain main arm 12 can be improved by the second layer 123. Therefore, the front curtain main arm 12 can be prevented from being broken and the drive pin hole 15 can be prevented from spreading, and the durability of the shutter device 100 can be made sufficient.

  The manufacturing method of the front curtain main arm 12 of the shutter device 100 according to the present embodiment is that the flat plate sheet made of the material constituting the base material 121 is provided with the bearing hole 14, the drive pin hole 15, the connecting hole 16, and the like. A base plate 121 is prepared by punching a flat sheet so as to have the shape of the leading curtain main arm 12. Thereafter, the base layer 121 is subjected to electro nickel plating to form the first layer 122. When the first layer 122 is formed on the entire surface of the substrate 121, the entire surface of the first layer 122 is subjected to electroless nickel plating. When the electroless nickel plating process was completed, a heat treatment was performed to increase the hardness of the second layer 123. In addition, these film-forming processes were also performed to the inner peripheral part of each hole of the base material 121. Further, although the manufacturing method of the leading curtain main arm 12 has been described, the same applies to the manufacturing methods of other arm members.

  Here, in the series of shutter operations, the driving pin 40 moves along the arc groove 37 to rotate the front curtain main arm 12 or the rear curtain main arm 22, so that the driving pin 40 and the driving pin are each time an exposure operation is performed. Friction due to sliding occurs between the holes 15 and 25. Further, since the arm member is stopped by causing the drive pin 40 to collide with the brake member 38, the arm member receives an impact force at the time of stopping each time the shutter operation is performed. This friction and impact force is repeatedly generated every time the shutter is released between the drive pin 40 and the drive pin holes 15 and 25. Here, conventionally, in a digital camera, since the user does not have to worry about film consumption, the number of shutter releases is inevitably increased as compared with a camera for a silver halide film. Therefore, there has been a problem that the load of friction and impact force has increased in recent shutter devices.

  In the shutter device 100 according to the present embodiment, damage such as deformation (for example, hole expansion) of the drive pin holes 15 and 25 of the arm member or generation of minute cracks in the arm member due to the impact force described above is prevented. Further, it is possible to prevent the drive pin holes 15 and 25 from being worn by impact or sliding, and to suppress the generation of wear powder.

  By preventing the arm member from being damaged, the durability of the shutter device 100 is improved, and the shutter performance of the single-lens reflex digital camera 1 can be prevented from being lowered. Moreover, since generation | occurrence | production of abrasion powder can also be prevented, it can prevent the contamination of the light-receiving surface of the image pick-up element 9 by abrasion powder, and can image | photograph with favorable image quality.

  Conventionally, in order to prevent damage to the arm member and the like, a method of dispersing the pressure received from the drive pin 40 by increasing the thickness of the arm member has been considered. However, according to the present embodiment, the arm member is formed thick. There is no need, and there is no possibility that the shutter speed becomes slow due to an increase in the weight of the arm member.

  Further, the front curtain follower arm 13 and the rear curtain follower arm 23 have the same configuration, so that they can withstand the friction and impact force applied to the bearing holes 14, 24 and the connection holes 16, 26 from the rotation shaft 50 and the connection pins. As a result, the durability of the shutter device 100 can be further improved by preventing the arm member from being damaged.

[Example]
Next, the durability test and the result of the shutter device 100 according to the present embodiment will be described.

  First, a drive pin hole 15, a bearing hole 14, and a connection hole 16 having a diameter of 1.6 mm are formed in a titanium base material 121 having a thickness of 150 μm. Then, after forming a first layer 122 by electro nickel plating with a thickness of 3 μm (film thickness variation ± 1 μm) and a second layer 123 by electroless nickel plating with a thickness of 12 μm (film thickness variation ± 2 μm), 300 ° C. The first curtain main arm 12 was formed by heat treatment for 1 hour. The substrate 121 had a hardness of 150 Hv, the first layer 122 had a hardness of 400 Hv, and the second layer 123 had a hardness of 750 Hv. Similarly, a front curtain slave arm 13, a rear curtain master arm 22 and a rear curtain slave arm 23 were formed.

  The shutter substrate 30 and the light shielding blades 12 to 14 are attached using the front curtain main arm 12, the front curtain slave arm 13, the rotation shaft 50, the drive pin 40, and the connecting pin. Similarly, the shutter substrate 30 and the light shielding blade 21 are attached using the rear curtain main arm 22, the rear curtain follower arm 23, the rotation shaft 50, the drive pin 40, and the connecting pin to form the shutter device 100.

  On the other hand, although it has the same connection structure as the shutter device 100 according to the present embodiment, a nickel layer having a thickness of 15 μm is formed by electroless nickel plating without forming the first layer, and then heat treatment is performed at 300 ° C. for 1 hour. A shutter device using a titanium arm member formed as described above was used as a comparative example of this durability test. The nickel layer had a hardness of 750 Hv. The conditions other than the presence or absence of the first layer are the same as in the example, and the outer dimensions of the arm member are also the same.

  In the durability test, shutter release was repeated 200,000 times at a curtain speed (corresponding to the travel speed of the shutter blades) of 2.9 msec. After the durability test, in the shutter device of the comparative example, the hole spreading and damage of the drive pin hole of the arm frequently occurred, but in the shutter device 100 of the present embodiment, the hole spreading and damage of the drive pin holes 15 and 25 were not recognized. .

  In the present embodiment, the first layer 122 and the second layer 123 are formed of nickel. However, the second layer 123 only needs to have higher hardness, and the material and the forming method can be changed. Moreover, the composition ratio of the metal element in the titanium alloy or the aluminum alloy as the material of the substrate 121 can be changed.

  Further, there is no particular limitation on the mounting method of the arm member, the shutter substrate 30, and the light shielding blades 11 and 21, and the shapes and dimensions of the drive pin 40, the rotation shaft 50, and the connecting pin may be adjusted as appropriate.

  Further, the focal plane shutter using the shutter device 100 and the arm member of the present embodiment can be applied not only to a single-lens reflex digital camera but also to a film type single-lens reflex camera.

It is a schematic block diagram of the single-lens reflex digital camera of this embodiment. It is a disassembled perspective view of the shutter apparatus of this embodiment. It is a front view in the state where the shutter device of this embodiment was charged. It is a front view of the state which the shutter apparatus of this embodiment complete | finished exposure operation | movement. It is a fragmentary sectional view of the arm member of this embodiment.

Explanation of symbols

SLR digital camera 1
Shutter device 100
First curtain 10
Shading blades 11, 21
Front curtain main arm 12
Base material 121
First layer 122
Second layer 123
Front curtain follower arm 13
Bearing holes 14, 24
Drive pin hole 15, 25
Connecting hole 16, 26
Trailer 20
Rear curtain main arm 22
Rear curtain follower arm 23
Shutter substrate 30
Opening 36
Arc groove 37
Drive pin 40
Rotating shaft 50

Claims (7)

A first layer formed by plating on the surface of the substrate;
An arm member comprising: a second layer having a hardness higher than that of the first layer and formed on the surface of the first layer by plating.   The arm member according to claim 1, wherein the first layer is formed by electrolytic nickel plating.   The arm member according to claim 1, wherein the second layer is formed by performing an electroless nickel plating process and then performing a heat treatment. The first layer has a Vickers hardness of 150 or more and 450 or less,
The arm member according to claim 1, wherein the second layer has a Vickers hardness of 450 or more and 800 or less.   The arm member according to any one of claims 1 to 4, wherein the base material is made of at least one of titanium, titanium alloy, aluminum, and aluminum alloy. A shutter substrate having an opening and a groove;
A drive pin that moves along the groove;
The arm member according to any one of claims 1 to 5, which moves relative to the shutter base material via the drive pin,
A shutter device comprising: a shutter blade attached to the arm member to open and close the opening. Forming a first layer by plating the surface of the substrate;
And a step of plating the surface of the first layer to form a second layer having a higher hardness than the first layer.

Images