Article, shutter, optical device, and method for manufacturing article

Abstract

To provide a shutter capable of long-term stable high-speed operation even when the light shielding blades, which are thin plates, undergo dynamic elastic deformation (bending) during the opening and closing operation, and the light shielding blades contact or slide against each other while suppressing the generation of stray light.SOLUTION: An article includes: a base material; a DLC layer covering at least a portion of the base material; and an antireflection layer covering at least a portion of the DLC layer. The manufacturing method of the article includes: a step of forming a DLC layer on at least part of the base material; and a step of forming an antireflection layer on at least a portion of the DLC layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an article, for example, to a light-shielding blade that constitutes a shutter used in an optical device such as a digital camera. [Background technology]

[0002] Conventionally, a focal plane shutter used in an optical device such as a camera has a blade mechanism as shown in FIG. The blade mechanism 51 is composed of blade arms 53a and 53b that drive the light-shielding blades 52, and a caulking pin 54 that fixes the light-shielding blades 52. The multiple light-shielding blades 52 reciprocate at high speed to open and close the light path, i.e., to control the exposure time.

[0003] In addition to the example shown in Figure 5, various other blade mechanisms can be configured. However, regardless of the structure adopted, the light-shielding blades must be lightweight to enable high-speed shutter operation. For this reason, light-shielding blades are generally constructed from thin, lightweight plates. These light-shielding blades are assembled so that they are spaced apart when stationary to prevent friction caused by contact with each other. However, with high-speed opening and closing operations, the thin light-shielding blades undergo dynamic elastic deformation (flexure), which can cause them to come into contact with or slide against each other.

[0004] Patent Document 1 describes a focal plane shutter that has a structure in which blades are sandwiched between a base plate and a plate member, and in which the surface of the plate member facing the blades is coated with DLC or diamond. It also describes that a DLC or diamond coating may be applied to an intermediate plate facing the blades. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-200448 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 addresses the issue of blade wear due to friction between the blades and the plate member, or between the blades and the intermediate plate, and describes applying a coating of DLC, diamond, or the like to the blade-facing surface of the plate member or intermediate plate. However, Patent Document 1 does not consider the problem of contact or sliding between the light-shielding blades due to dynamic elastic deformation (deflection) occurring in the thin plate light-shielding blades. Repeated contact or sliding between the light-shielding blades may deteriorate the surface condition of the light-shielding blades, hindering high-speed shutter operation, or generate wear particles that may adhere to the surfaces of optical components such as optical filters inside the camera.

[0007] To address this problem, the inventors attempted to accurately identify which parts of the light-shielding blade's light-shielding surface would come into contact or slide. However, in actual shutter devices, there are manufacturing errors in the individual light-shielding blades and assembly errors in the individual blade mechanisms. For this reason, there is variation in the dynamic elastic deformation (deflection) during the shutter opening and closing operation, and the inventors found that it is difficult to accurately identify in advance the parts of each light-shielding blade where contact or sliding occurs.

[0008] Furthermore, the light-shielding blades are required not only to block light but also to prevent light from being reflected from the light-shielding surface (the main surface of the blades).If light is reflected from the light-shielding surface (the main surface of the blades), stray light will be generated inside the camera body, which may cause ghosts in the captured image.

[0009] Therefore, there was a need for a shutter that could operate stably at high speeds for a long period of time and that suppressed the generation of stray light, even when the thin light-shielding blades undergo dynamic elastic deformation (flexion) during opening and closing operations, causing the blades to come into contact or slide against each other. [Means for solving the problem]

[0010] A first aspect of the present invention is a substrate, a DLC layer covering at least a portion of the substrate, and an anti-reflection layer covering at least a portion of the DLC layer. It is an item , the substrate has an uneven surface, the DLC layer is provided on the uneven surface, the antireflection layer is provided following the shape of the surface of the substrate on which the DLC layer is provided, and the antireflection layer has a portion provided only in a recess of the DLC layer; The article is characterized by the above.

[0011] In addition, a second aspect of the present invention is Has an uneven surface forming a DLC layer on at least a portion of a substrate; and forming an anti-reflection layer on at least a portion of the DLC layer. a removing step of removing a portion of the antireflection layer; Equipped with In the step of forming the DLC layer, the DLC layer is provided on the uneven surface; in the step of forming the antireflection layer, the antireflection layer is formed following the shape of the surface of the base material on which the DLC layer is provided; and in the removal step, a portion where the antireflection layer is provided only in the recesses of the DLC layer is formed. The present invention relates to a method for manufacturing an article. A third aspect of the present invention is a method for manufacturing an article, comprising the steps of forming a DLC layer on at least a portion of a substrate and forming an antireflection layer on at least a portion of the DLC layer, wherein the substrate has a textured surface, in the step of forming the DLC layer, the DLC layer is formed so as to follow the shape of the textured surface, and in the step of forming the antireflection layer, the antireflection layer is formed only in recesses of the textured surface of the substrate. [Effects of the Invention]

[0012] According to the present invention, even when the thin light-shielding blades undergo dynamic elastic deformation (flexure) during opening and closing operations, causing them to come into contact or slide against each other, it is possible to realize a shutter that can operate stably at high speeds for a long period of time and that suppresses the generation of stray light. [Brief explanation of the drawings]

[0013] [Figure 1] (a) A schematic cross-sectional view of the light-shielding component according to embodiment 1. (b) A schematic cross-sectional view for explaining a state in which a break-in operation has been performed on the light-shielding component according to embodiment 1. (c) A schematic plan view for explaining a state in which a break-in operation has been performed on the light-shielding component according to embodiment 1. [Figure 2] Ternary phase diagram showing the film quality of carbon film. [Figure 3] FIG. 1 is a perspective view showing the configuration of a focal plane shutter according to an embodiment. [Figure 4] FIG. 1 is a schematic diagram showing a schematic configuration of a camera according to an embodiment. [Figure 5] FIG. 3 is a diagram showing the configuration of a blade mechanism section. [Figure 6](a) A schematic cross-sectional view of a light-shielding component according to embodiment 2. (b) A schematic cross-sectional view for explaining a state in which a break-in operation has been performed on the light-shielding component according to embodiment 2. (c) A schematic plan view for explaining a state in which a break-in operation has been performed on the light-shielding component according to embodiment 2. [Figure 7] 1 is a graph showing the relationship between the refractive index of an anti-reflection material and Fresnel reflection. [Figure 8] 10(a) is a schematic cross-sectional view of a light-shielding component according to Embodiment 3. FIG. 10(b) is a schematic enlarged cross-sectional view of a part of the light-shielding component according to Embodiment 3. DETAILED DESCRIPTION OF THE INVENTION

[0014] A focal plane shutter according to an embodiment of the present invention will now be described with reference to the drawings. In the drawings referred to in the following description of the embodiments, elements denoted by the same reference numerals have the same functions unless otherwise specified.

[0015] Several embodiments are shown below, and in each embodiment, a different surface treatment is applied to the light-shielding surface of the light-shielding component, resulting in a different surface structure at a microscopic level. The light-shielding component of each embodiment can be used, for example, as the light-shielding blade of the blade mechanism shown in Fig. 5, but can also be used as a light-shielding blade of a blade mechanism having a different structure, or as a light-shielding component of another device.

[0016] [Embodiment 1] A first embodiment of the present invention will be described with reference to Fig. 1(a) to Fig. 1(c). Fig. 1(a) is a schematic cross-sectional view showing a state in which a surface coating treatment specific to this embodiment has been applied to the surface of a light-shielding component (light-shielding blade) as an article. Fig. 1(b) is a schematic cross-sectional view illustrating the state of the light-shielding component (light-shielding blade) at the stage when the light-shielding component of this embodiment has been incorporated into a shutter device and a break-in operation has been performed. Fig. 1(c) is a schematic plan view illustrating the state of the light-shielding component (light-shielding blade) at the stage when a break-in operation of the shutter device has also been performed.

[0017] As shown in FIG. 1(a), the light-shielding component 11 of this embodiment has a DLC film 13 (DLC layer) and an anti-reflection film 14 (anti-reflection layer) laminated on a thin plate-like base 12 (substrate).

[0018] A plate material obtained by rolling a magnesium alloy into a thin plate is preferably used for the base 12. By rolling, it is possible to process the plate material into a thickness of about 0.03 to 1.2 mm, and in this embodiment, taking into consideration the balance between strength and weight, a thickness of 0.1 mm was adopted for the base 12. However, the thickness of the base 12 can be changed as appropriate between 0.03 and 1.2 mm depending on the specifications of the shutter device.

[0019] Next, we will explain the DLC film 13 laminated on the base 12. In this embodiment, the DLC film 13 is laminated on the base 12 in order to suppress wear of the base 12 due to repeated use of the shutter device. As mentioned above, it is difficult to accurately identify in advance the areas where adjacent light-shielding blades dynamically come into contact or slide against each other, so in this embodiment, the DLC film 13 is coated over substantially the entire main surface (light-shielding surface) of the light-shielding blade.

[0020] The DLC film 13 is preferably 1 μm or thicker to ensure sufficient wear suppression (function to protect the base). However, if the thickness is 10 μm or thicker, there is a high possibility that cracks will occur during film formation or when the shutter is used after film formation (when dynamic bending occurs). For this reason, in this embodiment, the thickness of the DLC film 13 is set to 8 μm, but this can be changed as appropriate within the range of 1 μm or thicker and less than 10 μm.

[0021] The DLC film 13 can be formed, for example, by plasma CVD. An example of the film formation conditions is an argon gas flow rate of 50 sccm, a toluene gas flow rate of 2.5 sccm, a pressure of 5 Pa, an RF power of 300 W / 13.56 MHz, and a film formation time of 9.6 hours. The refractive index of the formed DLC film 13 was measured by ellipsometry, and found to be 1.9. Furthermore, the hardness was measured by nanoindentation, and found to be approximately 7 GPa.

[0022] The DLC film 13 is a so-called diamond-like carbon film. The ternary phase diagram shown in FIG. 2 represents the film quality of a carbon film using the hydrogen content and the ratio of sp2 bonds to sp3 bonds. Generally, ta-C, ta-C:H, aC, and aC:H are collectively referred to as diamond-like carbon (DLC). The DLC film 13 of this embodiment is a film formed by stacking diamond-like carbon (DLC) films that conform to this general definition. ta-C (tetrahedral amorphous carbon) is a carbon film with a high content of sp3 structures that form a regular tetrahedron, which is the crystal structure of diamond. ta-C:H (hydrogenated tetrahedral amorphous carbon) is a ta-C film containing hydrogen. aC (amorphous carbon) is a carbon film containing sp3 structures but with a higher proportion of sp2 structures (graphite) than ta-C. aC:H (hydrogenated amorphous carbon) is an a-C film containing hydrogen.

[0023] DLC films have a refractive index of 1.9 to 2.4, and films with a refractive index of about 2.1 have excellent wear-resistance properties. Because DLC films have such a high refractive index, if DLC film 13 is laminated over the entire light-shielding surface of base 12, Fresnel reflection will occur at the interface between DLC film 13 and air, causing stray light when used as a shutter device. However, according to this embodiment, by forming the anti-reflection film 14 on the DLC film 13, it is possible to significantly reduce Fresnel reflection occurring at the interface between the DLC film 13 and air.

[0024] The antireflection coating 14 according to this embodiment is a multilayer film in which high-refractive index materials and low-refractive index materials are alternately stacked to a predetermined thickness, and although a two-layer film is shown in the example of FIG. 1, the number of layers in the multilayer film is not limited to two. The high-refractive index material and the low-refractive index material referred to here are materials that have smaller refractive indices than the DLC film 13, but have different refractive indices.

[0025] In the example shown in FIG. 1(a), an anti-reflection coating 14 is formed by sputtering, with a first layer being a 30 nm alumina film (refractive index 1.77) and a second layer being an 85 nm silicon oxide film (refractive index 1.457), stacked in this order from the DLC film 13 side. The alumina film can be formed using an aluminum target under deposition conditions of, for example, an argon gas flow rate of 8 sccm, an oxygen flow rate of 2 sccm, a pressure of 0.3 Pa, an RF power of 200 watts / 13.56 MHz, and a deposition time of 33 minutes. The silicon oxide film can be formed using a silicon target under deposition conditions of, for example, an argon gas flow rate of 8 sccm, an oxygen flow rate of 2 sccm, a pressure of 0.5 Pa, an RF power of 200 watts / 13.56 MHz, and a deposition time of 24 minutes.

[0026] The reflectance of the light-shielding component 11 of this embodiment, coated with the anti-reflection coating 14, was measured using a spectrophotometer (V-7300DS manufactured by JASCO Corporation). The reflectance of the light-shielding component 11 of embodiment 1 was 0.8%. For comparison, when a light-shielding component having only the DLC film 13 formed thereon was measured, the average reflectance at wavelengths of 400 to 700 nm was as high as 12.8%. This is thought to be due to Fresnel reflection occurring at the interface between the DLC film 13 and air. It was confirmed that, according to this embodiment, by forming the anti-reflection coating 14 made of a multilayer film, a reflectance reduction effect of approximately 12% was obtained for the average reflectance at wavelengths of 400 to 700 nm.

[0027] When the configuration of the anti-reflection coating 14 was changed to a three-layer configuration in which, from the DLC film 13 side, a 50 nm TiO2 film (refractive index 2.49), a 30 nm alumina film, and a 75 nm silicon oxide film were stacked, the reflectance was 0.9%. When the anti-reflection coating 14 was changed to a two-layer configuration in which, from the DLC film 13 side, a 30 nm alumina film and a 75 nm silicon oxide film were stacked, the reflectance was 0.6%. In both cases, the reflectance was significantly reduced compared to when only the DLC film 13 was formed.

[0028] Next, a suitable method for mounting the light-shielding component 11 (optical component) of this embodiment in, for example, a camera (optical device) will be described. First, the light-shielding component 11 of this embodiment shown in Fig. 1(a) is used to assemble, for example, the blade mechanism shown in Fig. 5. Then, before mounting it in the optical device, a predetermined number of shutter opening and closing operations are performed as a break-in operation.

[0029] When the light-shielding components are brought into partial contact or sliding contact with each other due to dynamic elastic deformation (flexure) that occurs in the light-shielding components during the shutter opening and closing operation, the anti-reflection film 14 in that area is worn away, exposing the DLC film 13. To explain the state of the light-shielding component 11 upon completion of the break-in operation, Fig. 1(b) shows a schematic cross-sectional view, and Fig. 1(c) shows a schematic plan view. In the figure, EX indicates a portion where the anti-reflection film 14 has worn away due to contact or sliding contact between the light-shielding components, exposing the DLC film 13, and AR indicates a portion where no contact or sliding contact occurred and the anti-reflection film 14 remains covered.

[0030] When the break-in operation is complete, powder generated by abrasion of the anti-reflection film 14 is removed by, for example, air blowing, if necessary, and then the blade mechanism is attached to the camera.

[0031] Due to manufacturing errors in the light-shielding blades and assembly errors in the blade mechanisms, there are variations in the dynamic elastic deformation (flexure) of the light-shielding blades when the shutter is opened and closed, and so the position and size of the EX and AR may differ for each individual blade mechanism. However, according to this embodiment, in areas where actual contact or sliding occurs in each blade mechanism, the base 12 is protected by the exposed DLC film 13, making it possible to provide a shutter with extremely excellent durability. On the other hand, in areas where actual contact or sliding does not occur in each blade mechanism, the DLC film 13 is covered with the anti-reflection film 14, thereby suppressing reflections that are a source of stray light.

[0032] According to this embodiment, even when the thin light-shielding blades undergo dynamic elastic deformation (flexure) during opening and closing operations, causing them to come into contact or slide against each other, it is possible to provide a shutter that can operate stably at high speeds for a long period of time and that suppresses the generation of stray light.

[0033] FIG. 3 is a perspective view showing the configuration of a focal plane shutter 100 according to an embodiment. The focal plane shutter 100 has a base plate 101a and a cover plate 101b that face each other with a gap between them and have an exposure window 102, and a blade mechanism unit 51 (FIG. 5) disposed between the base plate 101a and the cover plate 101b. In FIG. 3, part of the light-shielding blades 52 of the blade mechanism unit can be seen through the exposure window 102 of the base plate 101a. The base plate 101a is provided with a blade drive mechanism 104a for driving the blade arm 53a shown in FIG. 5, and a blade drive mechanism 104b for driving the blade arm 53b shown in FIG. 5. The blade drive mechanism 104a is connected to the blade arm 3a shown in FIG. 5 via a blade drive pin 103a, and can rotate the blade arm 3a in conjunction with the movement of the blade drive mechanism 104a. 5 via a blade drive pin 103b, and can rotate the blade arm 3b in conjunction with the movement of the blade drive mechanism 104b. The rotation of the blade arms 3a and 3b causes the light-shielding blades 52 to open and close the exposure window 102.

[0034] 4 is a schematic diagram showing the general configuration of an optical device according to an embodiment. The optical device is, for example, a digital single-lens reflex camera system, and includes a camera body 700, which is an imaging device body, and an interchangeable lens 800 (lens barrel) that is detachable from the camera body 700. In FIG. 4, the interchangeable lens 800 is attached to the camera body 700.

[0035] The camera body 700 includes a housing 701, a shutter 702 according to the embodiment, and an image sensor 703. The interchangeable lens 800 has a housing 801 which is an interchangeable lens housing, and an imaging optical system 802 which is arranged inside the housing 801 and forms an optical image on the light receiving surface of the imaging element 732 when the housing 801 (interchangeable lens 800) is attached to the housing 701. The housing 801 has a lens-side mount 801a with an opening formed therein, and the housing 701 has a camera-side mount 701a with an opening formed therein. The interchangeable lens 800 (housing 801) is attached to the camera body 700 (housing 701) by fitting the lens-side mount 801a and the camera-side mount 701a together.

[0036] The condition of the shutter 702 was inspected every 25,000, 50,000, and 100,000 releases of the shutter 702. In this embodiment, it was confirmed that wear on the light-shielding blades 52 was suppressed even after many releases, and that light reflection on the light-shielding blades 52 was also suppressed by the anti-reflection coating 14. As a result, compared to a conventional shutter equipped with light-shielding blades that were not coated with the DLC film 13 and anti-reflection coating 14, this embodiment was able to improve the durability and image quality (stray light suppression) of the camera.

[0037] [Embodiment 2] A second embodiment of the present invention will be described. Note that the description of matters common to the first embodiment will be simplified or omitted. 6(a) is a schematic cross-sectional view showing the structure of a light-shielding component (light-shielding blade) according to this embodiment. The light-shielding component 21 of this embodiment has a thin plate-like base 22 (substrate) on which a DLC film 23 (DLC layer) and an anti-reflection film 24 (anti-reflection layer) are laminated.

[0038] As in the first embodiment, the base 22 can be, for example, a magnesium alloy plate with a thickness of 0.8 mm. However, whereas the first embodiment used a thin plate with a flat main surface on the side where the imaging light is incident, the present embodiment uses a thin plate with an uneven main surface on the side where the imaging light is incident. Specifically, a plate material formed by a rolling method was subjected to a blasting process to perform a surface roughening process to form an uneven surface with an arithmetic mean roughness Ra of approximately 0.1 μm. By using such a roughened base 22, the light-shielding parts (light-shielding blades) come into contact with each other only at the apexes of the convex parts when the shutter is opened and closed, and the sliding area is reduced, thereby reducing the driving force required to open and close the shutter.

[0039] In this embodiment, the DLC film 23 is coated on the roughened base 22. In this embodiment, the DLC film 23 can also be coated by, for example, plasma CVD. However, the deposition conditions were set to form a harder film than in the first embodiment due to the small contact area and to ensure reliable coating of the convex portions of the roughened surface. Specifically, the DLC film 23 was formed to a thickness of 1 μm under the following conditions: argon gas flow rate of 50 sccm, toluene gas flow rate of 2.5 sccm, pressure of 5 Pa, RF power of 500 W / 13.56 MHz, and deposition time of 2 hours. The DLC film 23 was deposited so that its surface had an uneven shape that conformed to the uneven surface of the base 22 (substrate). While a uniform thickness of the DLC film 23 is desirable, the thickness of the film covering the top surfaces of the convex portions and the bottom surfaces of the concave portions may be greater than the thickness of the film covering the slopes of the unevenness of the base 22. That is, the surface shape of the DLC film 23 does not need to exactly match the uneven shape of the base 22, as long as it is coated so as to roughly follow the shape. When the DLC film 23 was measured by the ellipsometry method, the refractive index was 2.1. When measured by the nanoindenter method, the hardness was approximately 15 GPa.

[0040] Next, the anti-reflection coating 24 will be described. The anti-reflection coating 24 according to this embodiment is made of a low-refractive index material with a predetermined thickness; for example, a 90-nm silicon oxide film is preferably used. Such a silicon oxide film can be formed by sputtering, for example, using a silicon target under the following film formation conditions: argon gas flow rate of 8 sccm, oxygen flow rate of 2 sccm, pressure of 0.5 Pa, RF power of 200 watts / 13.56 MHz, and film formation time of 25 minutes. The refractive index of the formed silicon oxide film was 1.457. While a uniform thickness of the anti-reflection coating 24 is desirable, the thickness covering the bottoms of recesses and the apexes of protrusions may be greater than the thickness covering the slopes of the DLC film 23. In other words, the surface shape of the anti-reflection coating 24 does not need to precisely match the contours of the DLC film 23; it is sufficient for the coating to roughly follow the shape.

[0041] Here, we will verify the effect of reducing Fresnel reflection by providing an anti-reflection film 24 with a refractive index smaller than that of the DLC film 23 on the surface of the DLC film 23, which has a refractive index of, for example, 2.1. The reflectance of the surface can be calculated using the following equation 1. R={(N0-N1) / (N0+N1)} 2 +{(N1-N2) / (N1+N2)} 2 (Equation 1) R:Reflectance N0: Refractive index of air N1: Refractive index of the anti-reflective material N2: Refractive index of DLC film

[0042] FIG. 7 shows a graph of reflectance when N0 = 1 and N2 = 2.1 are substituted into Equation 1, with N1 being a variable. The vertical axis in FIG. 7 represents reflectance at normal incidence. From FIG. 7, it can be seen that the value of N1 (refractive index of the anti-reflection material) that has the greatest reflectance reduction effect is approximately 1.45. In this embodiment, a significant reflectance reduction effect is achieved by coating the DLC film with a silicon oxide film having a refractive index of 1.457, as described above.

[0043] The total reflectance of the light-shielding component 21 of this embodiment, coated with the anti-reflection coating 24, was measured using a spectrophotometer (Konica Minolta CM-26d). It was confirmed that, compared to when only the DLC film 23 was formed, the formation of the anti-reflection coating 24 reduced the total reflectance by 3.5% in the average reflectance at wavelengths from 400 to 700 nm. Furthermore, because the sliding contact area was reduced by the roughening, the force required to drive the light-shielding component could be reduced.

[0044] As in the first embodiment, it is preferable that the light-shielding component 21 of this embodiment also be subjected to a break-in operation (a predetermined number of shutter opening and closing operations) after assembling the blade mechanism, and then be mounted in an optical device (camera system).

[0045] To explain the state of the light-shielding component 21 upon completion of the break-in operation, a schematic cross-sectional view is shown in FIG. 6(b), and a schematic plan view is shown in FIG. 6(c). In the figure, EXP denotes a region where contact and sliding between the light-shielding components has worn away part of the anti-reflection coating 24, exposing part of the DLC film 23. AR denotes a region where no contact or sliding occurred, leaving the anti-reflection coating 24 coated on the surface. In this embodiment, at the EXP region, the anti-reflection coating 24 has worn away near the peaks of the roughened surface, exposing the DLC film 23, while the anti-reflection coating 24 remains near the valleys of the roughened surface. Therefore, microscopically, the DLC film 23 is exposed only in the regions where contact occurs, while the other regions are covered with the anti-reflection coating 24.

[0046] It was confirmed that the light-shielding component 21 of this embodiment is protected from wear even after being mounted on a camera and subjected to numerous release operations, and that light reflection is suppressed by the anti-reflection film 24. As a result, compared to a case where a conventional shutter is attached that is made up of light-shielding blades that are not coated with the DLC film 23 and anti-reflection film 24, this embodiment has been able to improve the durability and image quality (stray light suppression) of the camera.

[0047] [Embodiment 3] The third embodiment of the present invention will be described below. Note that the description of matters common to the first and second embodiments will be simplified or omitted. This embodiment is similar to embodiment 2 in that the base surface of the light-blocking member is roughened, but the degree of roughening (depth of recesses, height of protrusions) is greater than in embodiment 2. A DLC film is formed on the roughened base surface, and a low refractive index material (anti-reflection coating) is applied only to the recesses of the DLC film's uneven surface, which reflects the roughened surface shape of the base. In a preferred embodiment, the low refractive index material (anti-reflection coating) is applied using a liquid-phase coating technique, and a porous low refractive index layer (anti-reflection coating) composed primarily of silicon oxide is formed in the recesses of the DLC film.

[0048] Fig. 8(a) is a schematic cross-sectional view showing the structure of a light-shielding component (light-shielding blade) according to this embodiment, and Fig. 8(b) is a schematic cross-sectional view enlarging a portion of Fig. 8(a). The light-shielding component 31 of this embodiment has a DLC film 33 (DLC layer) and an anti-reflection film 34 (anti-reflection layer) laminated on a thin plate-like base 32 (substrate).

[0049] The base 32 can be made of a lightweight material, as in the first and second embodiments. For example, a magnesium alloy plate having a thickness of 1.0 mm is used, and the surface is roughened by blasting, as in the second embodiment, but the degree of roughening is greater than in the second embodiment, with the arithmetic mean roughness Ra being 0.8 μm. In other words, deeper recesses than those in the second embodiment are formed in the base 32.

[0050] In this embodiment, a roughened base 32 is coated with a DLC film 33. The DLC film 33 can be coated using the same film-forming method as in Embodiments 1 and 2. However, the film-forming conditions were set in consideration of forming a harder film than in Embodiment 1 because the sliding contact area is small, and ensuring that the convex portions of the roughened surface are coated reliably. The deposited DLC film 33 was measured by ellipsometry and found to have a refractive index of 2.1. Furthermore, its hardness was measured by nanoindentation and found to be approximately 15 GPa. While it is desirable for the DLC film 33 to have a uniform thickness, the thickness covering the top surfaces of the convex portions and the bottom surfaces of the concave portions may be greater than the thickness covering the slopes of the unevenness of the base 32. In other words, the surface shape of the DLC film 33 does not need to strictly match the uneven shape of the base 32, as long as it is coated so as to roughly follow the shape.

[0051] Next, the anti-reflection film 34 will be described. As shown in Fig. 8, the anti-reflection film 34 according to this embodiment is formed in the recess of the base 32 covered with the DLC film 33. The anti-reflection film 34 is preferably made of a porous material in which inorganic particles are bound with a binder, and has a refractive index of 1.19 or more and 1.30 or less. The porosity of the porous material is preferably 30% or more and 50% or less. If the porosity is less than 30%, the refractive index will be high and a high anti-reflection effect may not be achieved. If the porosity is more than 50%, the mechanical strength of the anti-reflection film 34 will decrease, and the mechanical resistance to dynamic elastic deformation (deflection) during shutter opening and closing operations will be low. The shape of the inorganic particles may be any of circular, elliptical, discoid, rod-like, needle-like, chain-like, and angular, and may also be hollow particles with voids inside the particles. Materials constituting the inorganic particles are preferably those with a low refractive index, and examples include organic resins such as SiO2, MgF2, fluorine, and silicone. However, SiO2 is particularly preferred because of its ease of particle production.

[0052] The average particle diameter of the inorganic particles is preferably 10 nm or more and 100 nm or less, and more preferably 15 nm or more and 60 nm or less. Here, the average particle diameter of the inorganic particles refers to the average Feret diameter. This average Feret diameter can be measured by image processing of an image observed with a transmission electron microscope. Image processing can be performed using image processing software such as Image Pro PLUS (manufactured by Media Cybernetics). In a predetermined image area, the contrast can be adjusted appropriately if necessary, and the average Feret diameter of each particle can be measured by particle measurement, and the average value can be calculated.

[0053] The binder that binds the particles can be appropriately selected depending on the mechanical strength, adhesion, environmental reliability, etc. that the anti-reflection coating 34 should have. When silicon oxide particles are used as the inorganic particles, it is preferable to use a silicon oxide binder that has high affinity with the silicon oxide particles and can ensure the mechanical strength of the porous film. Among silicon oxide binders, it is preferable to use a silicate hydrolysis condensate.

[0054] The anti-reflection coating 34 is formed by applying a liquid coating containing at least inorganic particles, a binder, and a solvent. The coating is adjusted so that the inorganic particle content is 50 wt% to 85 wt% and the binder content is 15 wt% to 40 wt% of the total solid content.

[0055] After the coating material is applied to the substrate, it is dried. The coating method is not particularly limited, and any common coating method for a liquid coating solution, such as dip coating, spin coating, spray coating, or roll coating, can be used. For example, it is preferable to form a coating material by spin coating, from the viewpoint of being able to form a uniform film even on a substrate having a curved surface such as a lens, and from the viewpoint of being able to easily apply the coating material only to the minute recesses in the DLC film. Drying can be carried out using a dryer, hot plate, electric furnace, etc. Drying conditions are set at a temperature and time that will not affect the substrate and will allow the organic solvent contained in the coating to evaporate. In general, it is preferable to use a temperature of 300°C or less.

[0056] Specifically, for example, the anti-reflection coating 34 can be formed by spray coating a coating liquid containing 5 wt% inorganic particles made of silicon oxide under conditions of a liquid supply rate of 10 g / min, a spray gun movement speed of 20 m / min, and an atomization pressure of 0.1 MPa. When the refractive index of the formed porous anti-reflection coating 34, which is mainly composed of silicon oxide, was measured by the ellipsometry method, it was found to be 1.25.

[0057] The total reflectance of the light-shielding component 31 according to this embodiment was measured using a spectrophotometer (CM-26d manufactured by Konica Minolta). It was confirmed that, compared to the case where only the DLC film 33 is formed, the formation of the anti-reflection film 34 reduces the total reflectance by 4.5% in the average reflectance in the wavelength range from 400 to 700 nm.

[0058] 8(b), in this embodiment, the anti-reflection coating 34 is formed in the recesses (valleys) of the DLC film 33, but is not formed near the apexes of the protrusions (mountains) of the DLC film 33. Therefore, when the light-shielding component dynamically and elastically deforms (bends) during the shutter opening and closing operation, the DLC film 33 is exposed in the areas where contact or sliding contact with other light-shielding components occurs, i.e., near the apexes of the protrusions (mountains). Therefore, in this embodiment, it is not necessarily necessary to perform a break-in operation for the purpose of removing and cleaning the anti-reflection coating covering the areas where contact or sliding contact occurs.

[0059] It was confirmed that the light-shielding component 31 of this embodiment is protected from wear even after being mounted on a camera and subjected to numerous release operations, and that light reflection is suppressed by the anti-reflection film 34. As a result, compared to a case where a conventional shutter is attached that is made up of light-shielding blades that are not coated with the DLC film 33 and anti-reflection film 34, this embodiment has been able to improve the durability and image quality (stray light suppression) of the camera.

[0060] [Other embodiments] The present invention is not limited to the above-described embodiments and examples, and many modifications are possible within the technical concept of the present invention. For example, in the above-described embodiment, the DLC film and anti-reflection film are coated on the main surface of the blade member on the side where imaging light (photography light) is incident, but the DLC film may also be coated on the main surface of the blade member on the side where imaging light is not incident, or both the DLC film and anti-reflection film may be coated on the main surface on the side where imaging light is not incident.

[0061] Although a magnesium alloy thin plate is used for the base of the light-blocking component, other materials may also be used, such as super duralumin (which may be black anodized), composite materials containing carbon fiber, or lightweight materials such as mylar. [Explanation of symbols]

[0062] 11···Light-shielding part / 12···Base / 13···DLC film / 14···Anti-reflection film / 21···Light-shielding part / 22···Base / 23···DLC film / 24···Anti-reflection film / 31···Light-shielding part / 32···Base / 33···DLC film / 34···Anti-reflection film / 51···Blade mechanism / 52···Light-shielding blade / 53a, 53b···Blade arm / 54···Caulking pin / 100···Focal plate Lane shutter / 101a···Base plate / 101b···Cover plate / 102···Exposure window / 700···Camera body / 701···Housing / 701a···Camera side mount / 702···Shutter / 732···Image sensor / 800···Interchangeable lens / 801a···Lens side mount / AR···Areas where the anti-reflection coating remains on the surface / EX, EXP···Areas where the DLC coating is exposed

Claims

1. A substrate; a DLC layer covering at least a portion of the substrate; an anti-reflective layer covering at least a portion of the DLC layer, the substrate has an uneven surface, and the DLC layer is provided on the uneven surface; the anti-reflection layer is provided to follow the shape of the surface of the base material on which the DLC layer is provided, The anti-reflection layer has a portion provided only in the recessed portion of the DLC layer. An article characterized by:

2. the anti-reflection layer contains a material having a refractive index smaller than that of the DLC layer; 2. The article of claim 1.

3. the anti-reflection layer includes a first layer made of a material having a refractive index smaller than that of the DLC layer, and a second layer made of a material having a refractive index smaller than that of the first layer; 3. The article according to claim 1 or 2.

4. The article has a portion where the anti-reflection layer covering the DLC layer is exposed, and a portion where the DLC layer is exposed.

4. The article according to claim 1.

5. The antireflection layer is provided only in the recessed portions of the substrate.

5. The article according to any one of claims 1 to 4.

6. The article according to any one of claims 1 to 5 is provided as a blade member. A shutter characterized by:

7. The blade member has the DLC layer at least in a portion that comes into contact with another blade member.

7. The shutter of claim 6.

8. A shutter according to claim 6 or 7, An optical device characterized by:

9. The blade member has the anti-reflection layer at least on a surface on the side where image light is incident.

9. The optical device according to claim 8.

10. A step of forming a DLC layer on at least a portion of a substrate having an uneven surface; forming an anti-reflective layer on at least a portion of the DLC layer; a removal step of removing a portion of the antireflection layer, In the step of forming the DLC layer, the DLC layer is provided on the uneven surface, In the step of forming the anti-reflection layer, the anti-reflection layer is formed to follow the shape of the surface of the base material on which the DLC layer is provided; In the removing step, a portion in which the anti-reflection layer is provided only in the recessed portion of the DLC layer is formed. A method for manufacturing an article.

11. The step of forming the anti-reflection layer includes a step of laminating a material having a refractive index smaller than that of the DLC layer. The method for manufacturing an article according to claim 10.

12. the step of forming the anti-reflection layer includes the steps of forming a first layer made of a material having a refractive index smaller than that of the DLC layer, and forming a second layer made of a material having a refractive index smaller than that of the first layer. The method for manufacturing an article according to claim 10 or 11.

13. Furthermore, in the removing step, a portion of the anti-reflection layer is removed to expose a portion of the DLC layer. A method for manufacturing an article according to any one of claims 10 to 12.

14. In the step of forming the DLC layer, the DLC layer is formed so as to conform to the shape of the uneven surface. A method for manufacturing an article according to any one of claims 10 to 13.

15. In the step of forming the antireflection layer, the antireflection layer is formed so as to conform to the shape of the surface of the base material on which the DLC layer is provided.

15. A method for manufacturing an article according to claim 14.

16. A step of forming a DLC layer on at least a portion of a substrate; forming an anti-reflection layer on at least a portion of the DLC layer; the substrate has an uneven surface, and in the step of forming the DLC layer, the DLC layer is formed so as to follow the shape of the uneven surface; In the step of forming the antireflection layer, the antireflection layer is formed only on the recesses of the uneven surface of the base material. A method for manufacturing an article.

17. In the step of forming the antireflection layer, a porous low refractive index layer is formed by a liquid phase coating technique.

17. The method of claim 16, wherein the article is made of a material selected from the group consisting of:

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