JP2015102589A - Diaphragm blade and diaphragm mechanism having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diaphragm blade that has an excellent antireflection effect and is capable of withstanding high-speed movement.SOLUTION: In a diaphragm blade 1, a plurality of blades are overlapped, an opening is provided in an optical path, and the diaphragm diameter of the opening is variable. Black fine irregularities 13 are provided on at least one of surfaces 11 and 12 of a feather base material 10. Ribs 11a and 12a are set up in at least part of the peripheral part of the surface where the black fine irregularities are provided. Accordingly, the diaphragm blade 1 slides while the ribs 11a and 12a of adjoining diaphragm blades 1 come into contact with each other.

Description

  The present invention relates to an aperture blade for adjusting the amount of light passing through a lens of a camera and an aperture mechanism including the aperture blade.

  Conventionally, a camera such as a video camera or a digital camera with a built-in solid-state image pickup device or a camera using a film has a diaphragm mechanism for controlling the aperture diameter in order to adjust the amount of light of a subject imaged on the solid-state image pickup device or film. Is provided. Such a diaphragm mechanism is composed of a plurality of diaphragm blades arranged in an overlapping manner so as to form an annular shape, a holding ring for holding the diaphragm blades, and a cam member called a chrysanthemum that rotates the diaphragm blades. By rotating the aperture blade in conjunction with the chrysanthemum, it is possible to change the aperture diameter of the aperture formed by the inner diameter side edge of the aperture blade.

  The diaphragm blades constituting the diaphragm mechanism described above include a blade base material for shielding light, a swing shaft that is swingably attached to the holding ring, and a protrusion as an engaging portion that engages with the cam member. These protrusions are provided so as to protrude with respect to the blade base material.

  The blade base material of the diaphragm blades must absorb light efficiently so that the light does not reflect on the surface, so it is preferable that the blade base material is black and has a low surface reflectance. Further, since the diaphragm blades operate at a high speed while being overlapped with each other, it is necessary to have wear resistance capable of withstanding high-speed movement.

  Japanese Patent Application Laid-Open No. 10-312000 (Patent Document 1) discloses that a black pigment is added to a film of a blade material or a black coating mixed with an antireflective agent is applied in order to improve light shielding properties. Yes. However, even if these black treatments are performed, the surface of the aperture blade remains glossy, so that the antireflection effect is insufficient. For this reason, when adjusting the amount of light with the diaphragm blades, there is a problem that the blocked light is reflected and the reflected light hits the lens or the inner wall of the lens barrel and becomes stray light, causing flare and ghost.

  Japanese Patent Laid-Open No. 2002-229095 (Patent Document 2) discloses a plurality of steps in a step shape on an end surface along the opening of a plate member in order to suppress a ghost or the like caused by reflection of incident light on an end surface of a diaphragm blade. A diaphragm blade having a step is disclosed. However, the antireflection effect on the surface of the diaphragm blade is insufficient.

JP-A-10-312000 JP 2002-229095 A

  Accordingly, an object of the present invention is to provide a diaphragm blade that can withstand high-speed motion while having an excellent antireflection effect.

  Another object of the present invention is to provide an aperture mechanism having such aperture blades.

  As a result of earnest research in view of the above problems, the present inventors provide black fine irregularities on at least one surface of the blade base material, and provide ribs on at least a part of the peripheral portion of the surface provided with the black fine irregularities. Thus, it was discovered that a diaphragm blade having an excellent antireflection effect and capable of withstanding high-speed movement was obtained, and the present invention was conceived.

That is, the lens barrel and the manufacturing method thereof according to the present invention have the following features.
(1) A plurality of sheets are overlapped to provide an aperture in the optical path, the aperture blade changing the aperture diameter of the aperture, wherein at least one surface of the blade substrate is provided with black fine irregularities, A rib is provided on at least a part of a peripheral portion of the surface on which the black fine irregularities are provided, and the diaphragm blade slides while the ribs of the adjacent diaphragm blades are in contact with each other. Aperture blade.
(2) The diaphragm blade according to (1), wherein the rib is provided on at least a part of one side or both sides of the surface on which the black fine irregularities are provided.
(3) The diaphragm blade according to (1) or (2), wherein a cross section of the rib has a dome shape.
(4) The diaphragm blade according to any one of (1) to (3), wherein the black fine irregularities are a large number of microprojections having a height of 0.5 to 20 μm, which are randomly formed at a pitch of 0.1 to 30 μm. A diaphragm blade characterized by comprising:
(5) In the diaphragm blade according to any one of (1) to (4) above, the height of the rib is
A diaphragm blade characterized by being 30 to 300 μm.
(6) The diaphragm blade according to any one of (1) to (5), wherein the black fine unevenness is etched after nickel plating, nickel alloy plating, or any one of the plating treatments. A diaphragm blade characterized by
(7) The diaphragm blade according to any one of (1) to (6) above, wherein the black fine unevenness has a reflectance of 0.3% or less with respect to light having a wavelength of 400 nm to 680 nm. Aperture blade.
(8) The diaphragm blade according to any one of the above (1) to (7), wherein the blade base material is made of any metal material of stainless steel, aluminum, titanium, tantalum and magnesium, or an alloy thereof. A diaphragm blade characterized by that.
(9) The diaphragm blade according to any one of (1) to (8), wherein the black fine unevenness is provided on a portion of the surface of the diaphragm blade that is exposed to the optical path. Feathers.
(10) In the diaphragm blade according to any one of (1) to (8), the black fine unevenness is provided on a portion of the surface of the diaphragm blade that is opposed to incident light. Aperture blade.
(11) In the diaphragm blade according to any one of the above (1) to (10), a portion of the blade base material that is not provided with the black fine unevenness is black-dyed for light absorption, black coating, or black A diaphragm blade that is lubricated.
(12) An aperture mechanism characterized in that a plurality of aperture blades according to any one of (1) to (11) above are overlapped to provide an aperture in the optical path, and the aperture diameter of the aperture is variable.

  The diaphragm blade according to the present invention has a black fine unevenness on at least one surface of the blade base material, and a rib is provided on at least a part of the peripheral portion of the surface provided with the black fine unevenness. It is black compared to a blade base material that has been subjected to black processing, the surface reflection of light is suppressed, and it can withstand high-speed movement of the diaphragm blades. Therefore, since the antireflection function is higher than that of the conventional diaphragm blade, it is possible to effectively suppress the generation of ghosts and flares.

It is a figure which shows the aperture blade by one Example of this invention. It is AA sectional drawing which shows the aperture blade of FIG. It is BB sectional drawing which shows the aperture blade of FIG. FIGS. 4A and 4B are diagrams showing a diaphragm mechanism according to an embodiment of the present invention, in which FIGS. 4A and 4B show an open / close state of the diaphragm mechanism, and FIGS. It is a figure which shows the aperture blade by another Example of this invention. It is CC sectional drawing which shows the aperture blade of FIG. FIG. 6 is a DD cross-sectional view showing the diaphragm blade of FIG. 5. FIG. 6 is a diagram showing a diaphragm mechanism according to another embodiment of the present invention, where (a) shows the open / closed state of the diaphragm mechanism and (b) shows the throttle state of the diaphragm mechanism. It is a figure which shows the aperture blade by another Example of this invention. FIG. 10 is a cross-sectional view taken along the line E-E showing the diaphragm blade of FIG. 9. It is a figure which shows the aperture blade by another Example of this invention. (a) is an FF sectional view showing the diaphragm blade of FIG. 11 (a), and (b) is a GG sectional view showing the diaphragm blade of FIG. 11 (b). FIG. 10 is a diagram showing a diaphragm mechanism according to still another embodiment of the present invention, in which (a) shows an open / close state of the diaphragm mechanism, and (b) shows a diaphragm state of the diaphragm mechanism.

[1] Diaphragm Blade FIG. 1 shows a seven-diaphragm diaphragm blade 1 according to an embodiment of the present invention. The diaphragm blade 1 includes a blade base material 10, an engagement portion 14 provided on the surface 11 of the blade base material 10, a swing shaft 15 provided on the surface 12 of the blade base material 10, A rib 11a provided on one side of the surface 11 and a rib 12a provided on one side of the surface 12 of the blade substrate 10 are provided.

  Since the black fine irregularities 13 provided on the surface of the blade base material 10 are fragile, if the black fine irregularities 13 are rubbed by the high-speed opening / closing operation of the diaphragm blade 1, they are easily broken. Therefore, by providing ribs 11a and 12a higher than the black fine irregularities 13 on one side of the surfaces 11 and 12 of the blade base material 10, the diaphragm blades 1 slide while the ribs of the adjacent diaphragm blades 1 are in contact with each other. Therefore, it is possible to prevent the black fine irregularities 13 from being worn.

  On the surface of the blade base material 10, black fine irregularities 13 having antireflection performance are formed. The black fine irregularities 13 may be provided on the entire surface of the blade base material 10, but the black fine irregularities 13 are fragile and take time to form. What is necessary is just to be provided in the part. 2 is a cross-sectional view taken along the line AA of the diaphragm blade 1 of FIG. 1, and FIG. 3 is a cross-sectional view of the diaphragm blade 1 of FIG. In this embodiment, the black fine irregularities 13 are formed at the tip of the blade base material 10 and are not formed around the engaging portion 14 and the swing shaft 15. In addition, as shown in FIG. 2, it is desirable that black fine irregularities 13 are also provided on the side surfaces of the blade base 10. Thereby, reflection of light on the side surface of the blade substrate 10 can be prevented.

  It is preferable that the portion of the aperture blade 1 where the black fine irregularities 13 are not formed is subjected to black treatment such as light-absorbing black dyeing, black coating, and black lubrication treatment having an antireflection effect. Accordingly, a certain degree of antireflection effect can be obtained while maintaining the abrasion resistance and wear resistance of the diaphragm blade 1.

  The black fine irregularities 13 are preferably composed of a large number of fine protrusions having a height of 0.5 to 20 μm, which are randomly formed at a pitch of 0.1 to 30 μm. Thereby, reflection of light on the surface of the blade substrate 10 is suppressed, and the surface becomes black. Therefore, the antireflection function of the diaphragm blade 1 is enhanced, and the generation of ghosts and flares can be effectively suppressed.

  By providing the black fine irregularities 13, an excellent antireflection effect can be obtained not only for light incident perpendicularly to the surface but also for light incident obliquely to the surface. The antireflection effect of the black fine unevenness 13 is, for example, that the total reflectance for light with a wavelength of 430 nm to 760 nm incident perpendicularly to the surface is 0.3% or less, and the wavelength incident obliquely 20 ° with respect to the surface It is preferable that the total reflectance with respect to light of 430 nm to 760 nm is 0.3% or less.

  The shape of the ribs 11a and 12a is not particularly limited, but the cross section is preferably a dome shape. Thereby, the slidability of the blade 1 is improved. The ribs 11a and 12a may be provided on the entire sides of the surfaces 11 and 12 of the blade base 10, respectively. However, adjacent blades 1 always contact each other with the ribs 11a and 12a when the blade 1 is opened and closed. If so, it may be provided on at least a part of one side of the surfaces 11 and 12. Further, the surfaces of the ribs 11a and 12a are preferably subjected to black treatment such as black dyeing for light absorption having an antireflection effect, black coating, and black lubrication treatment.

  The height of the ribs 11a and 12a is not particularly limited as long as the diaphragm blade 1 can be slid so that the black fine unevenness 13 does not contact, but is preferably 0.03 to 0.3 mm. If the height of the ribs 11a and 12a is less than 0.02 mm, the black fine irregularities 13 may come into contact with the diaphragm blade 1 when it slides. If the height of the ribs 11a and 12a exceeds 0.4 mm, the diaphragm blade 1 is too thick.

  The engaging portion 14 and the swing shaft 15 are provided so as to protrude from the surfaces 11 and 12 of the blade base material 10, respectively. Steps may be provided at the ends of the engaging portion 14 and the swing shaft 15. As a result, the stepped portions of the engaging portion 14 and the swing shaft 15 abut against the surface of the adjacent blades 1, thereby reducing the contact area between the blades 1. Since there is a gap between adjacent blades 1 corresponding to the portion, wear of the black fine irregularities 13 can be suppressed.

  4A to 4D show a diaphragm mechanism 100 using seven diaphragm blades 1 according to an embodiment of the present invention. The diaphragm mechanism 100 includes seven diaphragm blades 1, an annular holding ring 101, and an annular chrysanthemum 102. In FIGS. 4B and 4D, the retaining ring 101 is omitted, and in FIG. 4A and FIG. 4C, the chrysanthemum 102 is omitted. The aperture mechanism 100 is arranged so that the aperture blades 1 overlap with each other in a ring shape with the optical axis as the center, with the aperture blades 1 being sandwiched between the holding ring 101 and the chrysanthemum 102.

  The retaining ring 101 has a bearing hole 16 that supports the swing shaft 15 of the diaphragm blade 1 so as to be swingable. The Kikuza 102 has guide grooves 17 with which the engaging portions 14 of the diaphragm blades 1 are respectively engaged. The holding ring 101 and the constellation 102 may be configured so that one of them is fixed to the optical device and the other is rotated around the optical axis by receiving a driving force. This will be described as a configuration in which is rotated.

  4 (a) and 4 (b), the engaging portion 14 comes into contact with one end of the guide groove 17, and the opening formed by the inner edge of the aperture blade 1 is in an open state, which is substantially the same as the opening of the holding ring 101. A case having a diameter is shown. In the open state shown in FIG. 4A, the rib 12a of the diaphragm blade 1 is in contact with 11a of one adjacent diaphragm blade 1 at the contact portion A, and the rib 11a of the diaphragm blade 1 is the other adjacent diaphragm. The rib 12a of the blade 1 is in contact with the contact portion B. As described above, the adjacent diaphragm blades 1 are in contact with each other between the ribs 11a and 12a, thereby preventing the black fine irregularities 13 of the diaphragm blades 1 from coming into contact with the adjacent diaphragm blades 1.

  When the chrysanthemum 102 rotates about the optical axis, the engaging portion 14 moves along the guide groove 17. As a result, the leading end of the diaphragm blade 1 rotates in the direction approaching the optical axis about the swing shaft 15. When the star seat 102 rotates to a position where the other end of the guide groove 17 and the engaging portion 14 come into contact with each other, as shown in FIGS. 4 (c) and 4 (d), the opening portion is in a throttle state. 4 (c), the rib 12a of the diaphragm blade 1 is in contact with the rib 11a of one adjacent diaphragm blade 1 at the contact portion A ', and the rib 11a of the diaphragm blade 1 is the other adjacent one. The diaphragm blade 1 is in contact with 12a at the contact portion B ′.

  When the diaphragm blade 1 transitions from the open state to the diaphragm state, the abutment portion A to A ′ while maintaining a state in which the rib 11a of the diaphragm blade 1 and the rib 12a of one of the diaphragm blades 1 adjacent to each other are always in contact. The abutment portion slides from B to B ′ while maintaining a state in which the rib 12a of the other diaphragm blade 1 and the rib 11a of the other diaphragm blade 1 adjacent to each other are always in contact with each other. Therefore, the aperture blade 1 can be opened and closed without the black fine irregularities 13 of the aperture blade 1 coming into contact with the adjacent aperture blade 1. Further, since the ribs 11a and 12a of the diaphragm blade 1 are provided, it is possible to prevent the black fine unevenness 13 of the diaphragm blade 1 from coming into contact with the holding ring 101 and the seat 102 when the diaphragm blade 1 slides. .

  5 to 7 show a seven-blade diaphragm blade 2 according to another embodiment of the present invention. The diaphragm blade 2 includes a blade base material 20, an engagement portion 24 provided on the surface 21 of the blade base material 20, a swing shaft 25 provided on the surface 22 of the blade base material 20, And a rib 22a provided on one side of the surface 22. The diaphragm blade 2 is different from the diaphragm blade 1 in that the ribs are provided only on one surface of the blade base material, but is otherwise common to the diaphragm blade 1 and the description of common parts is omitted.

  Black fine irregularities 23 are formed on the surface 22 of the blade substrate 20. The black fine irregularities 23 may be provided on the entire surface 22 of the blade base material 20, but may be provided on a portion of the surface 22 of the blade base material 20 that is exposed to the optical path. In the embodiment shown in FIG. 6, the black fine unevenness 23 is not provided on the side surface of the blade base material 20, but the black fine unevenness 23 may be provided on the side surface of the blade base material 20.

  FIGS. 8A and 8B show a diaphragm mechanism 200 using a plurality of diaphragm blades 2 according to another embodiment of the present invention. Except for the use of the aperture blade 2, the configuration is the same as that of the aperture mechanism 100, and the description of the common parts is omitted. In FIGS. 8 (a) and (b), Kikuza is omitted.

  FIG. 8 (a) shows an opening formed by the inner edge of the diaphragm blade 2, and the rib 22a of the diaphragm blade 2 is in contact with the surface of the adjacent diaphragm blade 2 on which the black fine irregularities 23 are not formed. Yes. This prevents the black fine irregularities 23 of the diaphragm blade 2 from coming into contact with the adjacent diaphragm blade 2. In the diaphragm state shown in FIG. 8B, the rib 22a of the diaphragm blade 2 is in contact with the surface of the adjacent diaphragm blade 2 on which the black fine irregularities 23 are not formed. Therefore, when the aperture blade 2 performs the opening / closing operation, the rib 22a of the aperture blade 2 and the surface of the adjacent aperture blade 2 are always in contact with each other while the abutting portion slides, and the black color of the aperture blade 2 is maintained. The opening / closing operation of the diaphragm blade 2 can be performed without the fine irregularities 23 coming into contact with the adjacent diaphragm blade 2.

  Thus, in this embodiment, since the black fine irregularities 23 are provided only on one side 22 of the blade base material 20, if the rib 22a is also provided only on one side 22, the black fine irregularities 23 are in contact with the adjacent diaphragm blade 2. Can be prevented. Further, when the aperture blade 2 performs the opening / closing operation, the rib 22a of the aperture blade 2 and the surface of the adjacent aperture blade 2 slide in a line contact state, so that the operation stability is increased. The surface 22 of the blade substrate 20 on which the black fine irregularities 23 are provided is preferably disposed on the side facing the incident light in the optical path. Thereby, scattering of incident light can be effectively prevented.

  9 and 10 show a seven-blade diaphragm blade 3 according to still another embodiment of the present invention. The diaphragm blade 3 includes a blade base material 30, an engagement portion 34 provided on the surface 31 of the blade base material 30, a swing shaft 35 provided on the surface 32 of the blade base material 30, Ribs 31a provided on both sides of the surface 31 and ribs 32a provided on both sides of the surface 32 of the blade base 30 are provided. Black fine irregularities 33 are formed on the surface of the blade substrate 30.

  The diaphragm blade 3 is different from the diaphragm blade 1 in that the ribs 31a and 32a are provided on both sides of the surface 31 and 32 of the blade base material, but is common to the diaphragm blade 1 in other points. The description of the part is omitted. By providing the ribs 31a and 32a on both sides of the blade base surfaces 31 and 32, the adjacent diaphragm blades 3 are brought into contact with each other by the ribs 31a and 32a on both sides. In addition, the black fine unevenness 33 of the diaphragm blade 3 can be more reliably prevented from coming into contact with the adjacent diaphragm blade 3. Further, it is possible to further prevent the black fine irregularities 33 of the diaphragm blade 3 from coming into contact with the retaining ring or the chrysanthemum when the diaphragm blade 3 slides.

  FIGS. 11 and 12 show two diaphragm blades 4a and 4b according to still another embodiment of the present invention. The diaphragm blade 4a includes a blade base material 40, an engagement portion 44 provided on the surface 41 of the blade base material 40, a swing hole 45 provided in the blade base material 40, and a surface 41 of the blade base material 40. A rib 41a provided on one side and a rib 42a provided on one side of the surface 42 of the blade base 40 are provided. The diaphragm blade 4b includes a blade base material 40, an engagement portion 44 provided on the surface 41 of the blade base material 40, a swing hole 45 provided in the blade base material 40, and a surface 41 of the blade base material 40. A rib 41b provided on one side and a rib 42b provided on one side of the surface 42 of the blade base 40 are provided.

  As shown in FIG. 12, black fine irregularities 43 are formed on the surface of the blade base 40 of the diaphragm blades 4a and 4b. The black fine irregularities 43 may be provided on the entire surface 22 of the blade base material 40, but may be provided on a portion of the surface 42 of the blade base material 40 that is exposed to the optical path. Description of the parts common to the diaphragm blades 1 is omitted.

  13 (a) and 13 (b) show a diaphragm mechanism 400 using two diaphragm blades 4a and 4b according to still another embodiment of the present invention. The diaphragm mechanism 400 includes two diaphragm blades 4a and 4b, an annular holding ring 401, and an annular chrysanthemum (not shown). The aperture mechanism 400 is arranged so that the aperture blades 4a and 4b are sandwiched between the holding ring 401 and the chrysanthemum so that the aperture blades 4a and 4b overlap to form a ring shape centered on the optical axis. Yes. The holding ring 401 has a swing shaft 46 that swings through the swing holes 45 of the diaphragm blades 4a and 4b. The diaphragm blades 4a and 4b are attached to the swing shaft 46 of the holding ring 401 with a space ring 47 interposed therebetween. By providing a gap between the diaphragm blades 4a and 4b by the spacing ring 47, it is possible to prevent the black fine irregularities 43 of the diaphragm blades 4a and 4b from coming into contact with the adjacent diaphragm blades 1. Description of the parts common to the diaphragm mechanism 100 is omitted.

  In the open state shown in FIG. 13 (a), the rib 41a of the diaphragm blade 4a is in contact with 42b of the diaphragm blade 4b. This prevents the black fine irregularities 43 of the diaphragm blades 4a and 4b from coming into contact with the other diaphragm blades 4a and 4b. Further, a spacing ring may be provided around the swinging holes 45 of the diaphragm blades 4a and 4b, and the spacing ring may be interposed between the diaphragm blades 4a and 4b and installed on the swinging shaft 46 of the holding ring 401. By providing a gap between the diaphragm blades 4a and 4b by the spacing ring, it is possible to prevent the black fine irregularities 43 of the diaphragm blades 4a and 4b from coming into contact with the adjacent diaphragm blade 1.

  Also in the throttle state shown in FIG. 13 (b), the rib 41a of the diaphragm blade 4a is in contact with 42b of the diaphragm blade 4b. As described above, when the aperture blades 4a and 4b perform the opening / closing operation, the abutment portion slides while maintaining the state where the rib 41a of the aperture blade 4a and the aperture 42b of the aperture blade 4b are in contact with each other. The aperture blades 4a and 4b can be opened and closed without the black fine irregularities 43 of 4b coming into contact with each other. Further, by providing the diaphragm blades 4a and the ribs 41b of the diaphragm blades 4b, the black fine irregularities 43 of the diaphragm blades 4a and 4b come into contact with the holding ring 401 and the seat when the diaphragm blades 4a and 4b slide. This can also be prevented.

  In the above embodiment, the diaphragm mechanism using the seven-blade and two-blade diaphragm blades is disclosed as an embodiment. However, the present invention is not limited to this, and various diaphragm blades such as a nine-blade diaphragm blade are disclosed. Applicable. The shape of the diaphragm blade is not limited to that of the above embodiment, and a diaphragm blade having a general shape can be used.

  The arrangement of the ribs on the blade base material is not limited to that of the above embodiment, but the peripheral part of the surface of the blade base material on which the black fine irregularities are provided so that the ribs of adjacent diaphragm blades slide while contacting each other. It suffices that at least a part of the rib is provided. Here, the “peripheral portion” indicates a portion in the vicinity of the side edge on the surface of the blade base material. In the said Example, although it provided in a little inner side from the side of a rib and a blade base material, you may provide a rib along the side of a blade base material. It is preferable that a rib is provided on at least a part of one side surface or both side surfaces of the surface provided with the black fine irregularities.

[2] Manufacturing Method of Diaphragm Blade A method of manufacturing the diaphragm blade of the present invention will be described below using the diaphragm blade 1 shown in FIGS. The blade base material 10 used for the diaphragm blade 1 can be formed, for example, by press-molding a thin metal plate. As a material of the metal thin plate, stainless steel, aluminum, copper, brass, phosphor bronze, or the like is used, and stainless steel is particularly preferable.

  The engaging portion 14 and the swing shaft 15 can be formed by integral molding with the blade base material 10, but they may be joined after being molded separately, and they are half-punched so as to protrude from the opposite surface. You may form by.

  The ribs 11a and 12a may be formed by integral molding with the blade base material 10, may be formed separately and then joined, or may each be formed by half-punching. The ribs 11a and 12a may be formed by printing using ink of a material on which nickel plating or nickel alloy plating is not formed. This eliminates the need for masking processing on the ribs 11a and 12a when the black fine irregularities 13 are formed.

  The black fine irregularities 13 are preferably formed by etching the surface of the blade substrate 10 after nickel plating treatment, nickel alloy plating treatment, or any plating treatment. Since the microprotrusions may be randomly arranged, they can be easily formed on the surface of the blade substrate 10. When the blade substrate 10 is made of stainless steel, the plating process is preferably an electroless nickel plating process or an electroless nickel alloy plating process. Before forming the black fine irregularities 13, the surface of the blade substrate 10 may be subjected to black alumite treatment.

  The black fine irregularities 13 are made of a nickel-phosphorus alloy, and are preferably amorphous. The phosphorus content is preferably 7 to 14% by mass when the total mass of the nickel-phosphorus alloy in the black fine irregularities 13 is 100%. Moreover, 2 to 5% of carbon mixed in the manufacturing process may be contained.

  When the black fine irregularities 13 are formed, masking may be applied to portions other than the formation surface of the black fine irregularities 13 of the aperture blade 1. This masking process is performed by, for example, a masking seal (masking tape). Furthermore, a nickel plating process or a nickel alloy plating process is performed on a portion not subjected to masking. This plating process is performed by plating immersion, for example.

  Next, the diaphragm blade 1 is etched. As a result, a large number of minute protrusions are randomly formed on the plating layer formed on the diaphragm blade 1, and the black fine irregularities 13 are formed. The etching process is performed by nitric acid etching, for example. Finally, by removing the masking, the black fine unevenness 13 can be formed in a predetermined portion of the diaphragm blade 1. Further, this etching step may be omitted if the height and pitch of the fine protrusions of the plating layer before the etching treatment are sufficient as the black fine irregularities 13.

  Finally, masking is removed. Further, nickel plating treatment or nickel alloy plating treatment may be performed without masking, and the portion of the plating not provided with the black fine irregularities 13 may be removed using a solvent.

1, 2, 3, 4a, 4b ... diaphragm blades
10, 20, 30, 40 ... blade base material
11a, 12a, 22a, 31a, 32a, 41a, 42a, 41b, 42b ... ribs
13, 23, 33, 43 ... black fine irregularities
14, 24, 34, 44 ... engaging part
15, 24, 35 ... Oscillating shaft
45 ... Oscillating hole
100, 200, 400 ... diaphragm mechanism
101, 401 ... retaining ring
16 ... Bearing hole
46 ... Oscillating shaft
102 ... Kikuza
17 ... Guide groove

Claims (12)

  A diaphragm blade that overlaps a plurality of sheets to provide an opening in the optical path and varies a diaphragm diameter of the opening, and the black fine unevenness is provided on at least one surface of the blade base material. A rib is provided on at least a part of a peripheral portion of the surface on which the diaphragm is provided, and the diaphragm blade slides while the ribs of the adjacent diaphragm blades are in contact with each other.   2. The diaphragm blade according to claim 1, wherein the rib is provided on at least a part of one side or both sides of the surface on which the black fine irregularities are provided.   3. The diaphragm blade according to claim 1, wherein a cross section of the rib has a dome shape.   The diaphragm blade according to any one of claims 1 to 3, wherein the black fine irregularities are formed of a large number of microprojections having a height of 0.5 to 20 µm and randomly formed at a pitch of 0.1 to 30 µm. Aperture blade. The diaphragm blade according to any one of claims 1 to 4, wherein the height of the rib is
A diaphragm blade characterized by being 30 to 300 μm.   The diaphragm blade according to any one of claims 1 to 5, wherein the black fine irregularities are formed by a nickel plating process, a nickel alloy plating process, or an etching process after any one of the plating processes. Aperture blade.   The diaphragm blade according to any one of claims 1 to 6, wherein the black fine unevenness has a reflectance of 0.3% or less with respect to light having a wavelength of 400 nm to 680 nm.   The diaphragm blade according to any one of claims 1 to 7, wherein the blade base material is made of any metal material of stainless steel, aluminum, titanium, tantalum and magnesium, or an alloy thereof. Feathers.   The diaphragm blade according to any one of claims 1 to 8, wherein the black fine irregularities are provided on a portion of the surface of the diaphragm blade that is exposed to the optical path.   The diaphragm blade according to any one of claims 1 to 8, wherein the black fine irregularities are provided on a portion of the surface of the diaphragm blade that opposes incident light.   The diaphragm blade according to any one of claims 1 to 10, wherein a portion of the blade base material that is not provided with the black fine unevenness is subjected to black dyeing for light absorption, black coating, or black lubrication treatment. A diaphragm blade characterized by   12. An aperture mechanism, wherein a plurality of aperture blades according to claim 1 are overlapped to provide an aperture in an optical path, and the aperture diameter of the aperture is varied.

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