Light-shielding material

Abstract

To provide a light-shielding material that excels in weight reduction. [Solution] The light-shielding member 1 comprises a metal core layer 2 and a low-reflection layer 4 covering the core layer 2. The area of ​​the core layer 2 in plan view is 85% or less of the area of ​​the light-shielding member 1 in plan view. The 5° specular reflectance of the low-reflection layer 4 is lower than the 5° specular reflectance of the core layer 2.

Description

Technical Field

[0001] The present invention relates to a light-shielding member.

Background Art

[0002] Conventionally, as a light-shielding member, a light-shielding member provided with an optical multilayer film on the surface of a base material is known (see, for example, Patent Document 1 below).

[0003] The base material is made of resin. The optical multilayer film is composed of a light absorption layer and a dielectric layer. The light absorption layer and the dielectric layer are made of metal or metal oxide.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] On the other hand, further weight reduction is required for the light-shielding member.

[0006] The present invention provides a light-shielding member excellent in weight reduction.

Means for Solving the Problems

[0007] The light-shielding member of the present invention [1] includes a metal core layer and a low-reflection layer covering the core layer, wherein the area of the core layer in a plan view is 85% or less of the area of the light-shielding member in a plan view, and the 5° normal reflectance of the low-reflection layer is lower than the 5° normal reflectance of the core layer.

[0008] According to such a configuration, the weight of the light-shielding member can be reduced.

[0009] The present invention [2] includes the light-shielding member described in [1] above, wherein the external shape of the core layer is dissimilar to the external shape of the light-shielding member.

[0010] This configuration allows for significant weight reduction of the light-shielding component while also enabling free design of its external shape.

[0011] The present invention [3] provides that the light-shielding member has through holes that penetrate in the thickness direction, The core layer includes the light-shielding member described in [1] or [2] above, which comprises a peripheral portion of the through-hole that is arranged around the through-hole when viewed in the thickness direction.

[0012] This configuration allows for improved mechanical strength around the through-hole.

[0013] The present invention [4] includes the light-shielding member described in [3] above, wherein the core layer comprises a main rib portion extending from the periphery of the through hole to the opposite side of the through hole with respect to the periphery of the through hole.

[0014] With this configuration, the main frame can improve mechanical strength.

[0015] The present invention [5] includes the light-shielding member described in [4] above, wherein the core layer comprises a secondary bone portion extending from the main bone portion in a direction intersecting the direction in which the main bone portion extends.

[0016] With this configuration, the mechanical strength can be improved by the auxiliary frame.

[0017] The present invention [6] includes the light-shielding member described in [5] above, wherein the auxiliary bone portion is arranged in a plurality at intervals in the direction in which the main bone portion extends.

[0018] With this configuration, the mechanical strength can be further improved by the auxiliary frame.

[0019] The present invention [7] includes the light-shielding member described in [3] above, wherein the core layer has a plurality of core sub-through holes penetrating in the thickness direction.

[0020] According to such a configuration, the light-shielding member can be surely lightened.

[0021] The present invention [8] includes the light-shielding member described in [7] above, wherein the plurality of core sub-through holes are regularly arranged.

[0022] According to such a configuration, while achieving weight reduction, it is possible to suppress an irregular decrease in mechanical strength.

[0023] The present invention [9] further includes a resin layer disposed between the core layer and the low-reflection layer, and includes the light-shielding member according to any one of [1] to [8] above.

[0024] According to such a configuration, durability can be improved.

Effects of the Invention

[0025] According to the light-shielding member of the present invention, weight reduction can be achieved.

Brief Description of the Drawings

[0026] [Figure 1] FIG. 1 is a plan view of a light-shielding member as an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line A-A of the light-shielding member shown in FIG. 1. [Figure 3] FIG. 3 is a plan view of the core layer in the light-shielding member shown in FIG. 1. [Figure 4]Figures 4A to 4F show one embodiment of the manufacturing method for the light-shielding member shown in Figure 1. Figure 4A shows the first step of preparing the resin layer. Figure 4B shows the second step of forming a seed layer on one side in the thickness direction of the resin layer. Figure 4C shows the second step of placing a core layer on one side in the thickness direction of the seed layer. Figure 4D shows the third step of covering the core layer with the resin layer. Figure 4E shows the fourth step of covering the resin layer with a metal layer. Figure 4F shows the fourth step of covering the resin layer with a low-reflection layer via the metal layer. [Figure 5] Figures 5A to 5F show modified examples of the light-shielding member of the present invention. Figure 5A shows the first modified example. Figure 5B shows the second modified example. Figure 5C shows the third modified example. Figure 5D shows the fourth modified example. Figure 5E shows the fifth modified example. Figure 5F shows the sixth modified example. [Figure 6] Figures 6A to 6D show modified examples of the manufacturing method of the light-shielding member shown in Figure 1. Figure 6A shows the first step of preparing a substrate made of the core layer material. Figure 6B shows the first step of preparing the core layer by removing the substrate by etching. Figure 6C shows the sixth step of covering the core layer with a resin layer. Figure 6D shows the seventh step of covering the resin layer with a low-reflection layer. [Figure 7] Figures 7A and 7B are plan views of modified examples of the light-shielding member of the present invention (light-shielding member with guide grooves). Figure 7A shows a light-shielding member with guide grooves. Figure 7B shows a light-shielding member in which the core layer comprises a portion around the through-hole and a portion around the guide grooves. [Modes for carrying out the invention]

[0027] 1. One Embodiment An embodiment of the light-shielding member of the present invention will be described with reference to Figures 1 and 2.

[0028] In Figure 1, the vertical direction of the paper corresponds to the minor axis direction. The top of the paper corresponds to one side of the minor axis direction, and the bottom of the paper corresponds to the other side of the minor axis direction. The horizontal direction of the paper corresponds to the major axis direction, which is perpendicular to the minor axis direction. Specifically, this corresponds to the direction arrows in each figure.

[0029] As shown in Figure 1, the light-shielding member 1 has a substantially elliptical shape in plan view.

[0030] As shown in Figure 2, the light-shielding member 1 has a first main surface 11, a second main surface 12, an outer peripheral surface 13, and a through hole 14.

[0031] The first main surface 11 is a flat surface.

[0032] The second main surface 12 is positioned opposite the first main surface 11 on the other side in the thickness direction, separated by a gap. The second main surface 12 is parallel to the first main surface 11. The second main surface 12 is a flat surface.

[0033] A flat surface is a surface that appears flat at first glance; for example, minute irregularities or undulations of less than 15 μm are acceptable (the same applies hereafter).

[0034] The outer circumferential surface 13 is continuous with the peripheral edge of the first main surface 11 and the peripheral edge of the second main surface 12. The outer circumferential surface 13 extends in the thickness direction. The outer circumferential surface 13 is a flat surface.

[0035] The through-hole 14 penetrates the light-shielding member 1 in the thickness direction. By inserting a fixing member (not shown) through the through-hole 14, the light-shielding member 1 can be rotated around the fixing member as its central axis. By rotating the light-shielding member 1, it can assume a light-shielding position or a light-entering position with respect to the object to be shielded (not shown).

[0036] The through hole 14 has an inner circumferential surface 15.

[0037] The through hole 14 is a round hole. If the through hole 14 is a round hole, rotational performance can be improved. The inner diameter of the through hole 14 is, for example, 50 μm to 1000 μm, preferably 100 μm to 500 μm.

[0038] The light-shielding member 1 blocks at least visible light.

[0039] The visible light transmittance (JIS7375) in the thickness direction of the light-shielding member 1 is, for example, 1.0% or less, preferably 0.01% or less, and more preferably 0%.

[0040] The 5° specular reflectance of visible light on the first main surface 11, second main surface 12, outer peripheral surface 13, and inner peripheral surface 15 of the light-shielding member 1 is, for example, 1.0% or less, preferably 0.5% or less, and also, for example, 0% or more.

[0041] The specular reflectance mentioned above is measured by the average value of the reflectance of visible light with wavelengths of 500 nm to 600 nm.

[0042] The bending modulus of elasticity (JIS7171) of the light-shielding member 1 is, for example, 10 GPa to 250 GPa, preferably 50 GPa to 200 GPa.

[0043] The thickness T of the light-shielding member 1 is, for example, 10 μm to 150 μm, preferably 20 μm to 100 μm, and more preferably 30 μm to 90 μm.

[0044] More specifically, the thickness T of the light-shielding member 1 is, for example, 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more, and also, for example, 150 μm or less, preferably 100 μm or less, more preferably 90 μm or less.

[0045] The length of the long axis of the light-shielding member 1 is, for example, 1.0 μm to 30.0 μm, preferably 3.0 μm to 10.0 μm.

[0046] The length of the short axis of the light-shielding member 1 is, for example, 0.5 μm to 15.0 μm, preferably 1.0 μm to 7.0 μm.

[0047] The light-shielding member 1 comprises a core layer 2, a resin layer 3, and a low-reflection layer 4.

[0048] <Core Layer> As shown in Figures 2 and 3, the core layer 2 is positioned approximately in the center of the light-shielding member 1 in the thickness direction. The core layer 2 extends in an orthogonal direction. In plan view, the core layer 2 has a roughly key shape.

[0049] The core layer 2 has a first core main surface 21, a second core main surface 22, a core outer peripheral surface 23, and a core main through hole 24.

[0050] The first main surface 21 of the core is a flat surface.

[0051] The second core surface 22 is positioned opposite the first core surface 21 on the other side in the thickness direction, separated by a gap. The second core surface 22 is parallel to the first core surface 21. The second core surface 22 is a flat surface.

[0052] The core outer circumferential surface 23 is continuous with the peripheral edge of the core first main surface 21 and the peripheral edge of the core second main surface 22. The core outer circumferential surface 23 is a flat surface.

[0053] The core main through-hole 24, when viewed from the thickness direction of the light-shielding member 1, includes the through-hole 14 and the resin through-hole 34 (described later), and penetrates in the thickness direction. The core main through-hole 24 has a similar shape to the through-hole 14. The core main through-hole 24 shares a center with the through-hole 14.

[0054] The main through-hole 24 of the core has an inner circumferential surface 25 of the core.

[0055] The inner diameter of the main through-hole 24 of the core is, for example, 50 μm to 1000 μm, preferably 100 μm to 500 μm.

[0056] The ratio of the inner diameter of the through-hole 14 to the inner diameter of the main through-hole 24 of the core is, for example, 0.5 to 1.0, preferably 0.8 to 1.0.

[0057] Furthermore, as shown in Figure 3, the core layer 2 comprises, when viewed in the thickness direction, a through-hole peripheral portion 26 arranged around the through-hole 14, and a main bone portion 27A extending from the through-hole peripheral portion 26 to the opposite side of the through-hole 14 from the through-hole peripheral portion 26 (one side in the longitudinal axis direction of the light-shielding member 1).

[0058] The peripheral portion 26 of the through-hole has a roughly ring shape in plan view. More specifically, the peripheral portion 26 of the through-hole shares a center with the through-hole 14 and has a similar shape to the through-hole 14.

[0059] The through-hole periphery portion 26 improves the mechanical strength of the through-hole periphery portion 26. In particular, when a fixing member (not shown) is inserted through the through-hole 14 and the light-shielding member 1 is rotated around the fixing member as its central axis, mechanical strength is required around the through-hole 14. On the other hand, the through-hole periphery portion 26 improves the mechanical strength of the through-hole periphery portion 26, thereby improving the mechanical strength around the through-hole 14.

[0060] The peripheral portion 26 of the through hole has a larger inner diameter than the through hole 14.

[0061] The inner diameter of the peripheral portion 26 of the through hole is the same as the inner diameter of the main core through hole 24.

[0062] The ratio of the inner diameter of the through hole 14 to the inner diameter of the peripheral portion 26 of the through hole is, for example, 0.5 to 1.0, preferably 0.8 to 1.0.

[0063] The main bone portion 27 has a roughly rectangular (straight) shape when viewed from above.

[0064] The length of the main bone portion 27 in the longitudinal direction is, for example, 1 mm to 28 mm, preferably 3 mm to 8 mm.

[0065] The outer shape of the core layer 2 consists of the outer shape of the through-hole peripheral portion 26 (approximately ring-shaped in plan view) and the outer shape of the main frame portion 27 (approximately rectangular in plan view). In other words, the outer shape of the core layer 2 is dissimilar to the outer shape of the light-shielding member 1 (approximately elliptical in plan view).

[0066] If the external shape of the core layer 2 is dissimilar to the external shape of the light-shielding member 1, the light-shielding member 1 can be reliably made lighter while allowing for free design of its external shape.

[0067] Furthermore, the area of ​​the core layer 2 in plan view is 85% or less, preferably 60% or less, more preferably 40% or less, and for example, 2% or more, relative to the area of ​​the light-shielding member 1 in plan view.

[0068] If the area of ​​the core layer 2 in plan view is less than or equal to the above upper limit relative to the area of ​​the light-shielding member 1 in plan view, then weight reduction is superior.

[0069] If the area of ​​the core layer 2 in plan view exceeds the above upper limit relative to the area of ​​the light-shielding member 1 in plan view, the weight reduction is insufficient.

[0070] Furthermore, if the area of ​​the core layer 2 in plan view is greater than or equal to the lower limit mentioned above relative to the area of ​​the light-shielding member 1 in plan view, the mechanical strength can be improved.

[0071] The thickness T1 of the core layer 2 is, for example, 5 μm to 70 μm, preferably 10 μm to 30 μm.

[0072] More specifically, the thickness T1 of the core layer 2 is, from the viewpoint of improving rigidity, for example, 5 μm or more, preferably 10 μm or more, and for example, 70 μm or less, preferably 30 μm or less.

[0073] When the thickness T of the light-shielding member 1 is set to 100%, the thickness T1 of the core layer 2 is, for example, 10% to 99%, preferably 15% to 97%.

[0074] More specifically, when the thickness T of the light-shielding member 1 is set to 100%, the thickness T1 of the core layer 2 is, for example, 10% or more, preferably 15% or more, from the viewpoint of improving rigidity, and for example, 99% or less, preferably 97% or less, from the viewpoint of reducing weight.

[0075] The core layer 2 is made of metal. Examples of materials for the core layer 2 include copper, copper alloys, stainless steel, aluminum, titanium, nickel, tantalum, and magnesium. Preferably, the materials for the core layer 2 are copper and stainless steel.

[0076] The 5° specular reflectance of visible light in core layer 2 is, for example, 10% to 80%.

[0077] <Resin layer> The resin layer 3 is placed between the core layer 2 and the low-reflection layer 4.

[0078] The resin layer 3 has an elliptical shape in plan view and a shape similar to that of the light-shielding member 1.

[0079] The resin layer 3 covers the core layer 2. The resin layer 3 covers the first main surface 21 of the core, the second main surface 22 of the core, the outer surface 23 of the core, and the inner surface 25 of the core. The resin layer 3 improves durability.

[0080] The resin layer 3 has a first resin main surface 31, a second resin main surface 32, a resin outer peripheral surface 33, and resin through holes 34.

[0081] The first main surface 31 of the resin is a flat surface. The first main surface 31 of the resin covers the first main surface 21 of the core.

[0082] The second resin main surface 32 is positioned opposite the first resin main surface 31 on the other side in the thickness direction, separated by a gap. The second resin main surface 32 is parallel to the second resin main surface 32. The second resin main surface 32 is a flat surface. The second resin main surface 32 covers the second core main surface 22.

[0083] The resin outer circumferential surface 33 is continuous with the peripheral edge of the first resin main surface 31 and the peripheral edge of the second resin main surface 32. The resin outer circumferential surface 33 has a similar shape to the outer circumferential surface 13. The resin outer circumferential surface 33 covers the core outer circumferential surface 23.

[0084] The resin through-hole 34, when viewed from the thickness direction of the light-shielding member 1, includes the through-hole 14 and is included in the core main through-hole 24, and penetrates in the thickness direction. The resin through-hole 34 has a similar shape to the through-hole 14. The resin through-hole 34 shares a center with the through-hole 14.

[0085] The resin through-hole 34 has a resin inner circumferential surface 35. The resin inner circumferential surface 35 covers the core inner circumferential surface 25.

[0086] The thickness T2 of the resin layer 3 is, for example, 3 μm to 50 μm, preferably 5 μm to 20 μm.

[0087] More specifically, the thickness T2 of the resin layer 3 is, from the viewpoint of improving durability, for example, 3 μm or more, preferably 5 μm or more, and for example, 500 μm or less, preferably 20 μm or less.

[0088] The thickness T2 of the resin layer 3 is thinner than the thickness T1 of the core layer 2. If the thickness T1 of the core layer 2 is taken as 100%, the thickness T2 of the resin layer 3 is, for example, 40% to 90%, preferably 50% to 70%.

[0089] When the thickness T of the light-shielding member 1 is set to 100%, the thickness T2 of the resin layer 3 is, for example, 5% to 40%, preferably 10% to 30%.

[0090] More specifically, when the thickness T of the light-shielding member 1 is set to 100%, the thickness T2 of the resin layer 3 is, for example, 5% or more, preferably 10% or more, and also, for example, 40% or less, preferably 30% or less, from the viewpoint of improving durability.

[0091] Examples of materials for the resin layer 3 include resins. Examples of resins include acrylic resins, epoxy resins, polyimides (e.g., photosensitive polyimides), and silicone-based resins. Polyimides are preferred as the resin. In other words, the resin layer 3 preferably contains polyimides. If the resin layer 3 contains polyimides, it will have excellent dimensional accuracy.

[0092] The 5° specular reflectance of the resin layer 3 in visible light is, for example, 5% to 20%.

[0093] <Low reflective layer> The low-reflection layer 4 covers the core layer 2 and the resin layer 3. More specifically, the low-reflection layer 4 covers the first main resin surface 31, the second main resin surface 32, the outer resin surface 33, and the inner resin surface 35. More specifically, as described above, the light-shielding member 1 has a first main surface 11, a second main surface 12, an outer peripheral surface 13, and a through hole 14 having an inner peripheral surface 15. In other words, the low-reflection layer 4 has a first main surface 11, a second main surface 12, an outer peripheral surface 13, and an inner peripheral surface 15. The first main surface 11 covers the first resin main surface 31. The second main surface 12 covers the second resin main surface 32. The outer peripheral surface 13 covers the outer resin peripheral surface 33. The inner peripheral surface 15 covers the inner resin peripheral surface 35.

[0094] The 5° specular reflectance of visible light in the low-reflection layer 4 is lower than the 5° specular reflectance of visible light in the core layer 2. The 5° specular reflectance of visible light in the low-reflection layer 4 is, for example, 1.0% or less, preferably 0.5% or less, for example 0% or more.

[0095] The thickness T3 of the low-reflection layer 4 is, for example, 0.01 μm to 30 μm, preferably 0.05 μm to 20 μm.

[0096] More specifically, the thickness T3 of the low-reflection layer 4 is, from the viewpoint of improving light shielding, for example, 0.01 μm or more, preferably 0.05 μm or more, for example 30 μm or less, preferably 20 μm or less.

[0097] When the thickness T1 of the core layer 2 is set to 100%, the thickness T3 of the low-reflection layer 4 is, for example, 0.1% to 150%, preferably 0.3% to 140%.

[0098] When the thickness T of the light-shielding member 1 is set to 100%, the thickness T3 of the low-reflection layer 4 is, for example, 0.05% to 40%, preferably 0.1% to 30%.

[0099] More specifically, when the thickness T of the light-shielding member 1 is set to 100%, the thickness T3 of the low-reflection layer 4 is, for example, 0.05% or more, preferably 0.1% or more, from the viewpoint of improving light-shielding performance, and for example, 40% or less, preferably 30% or less, from the viewpoint of weight reduction.

[0100] The surface roughness Ra (arithmetic mean surface roughness according to JIS B 0601-2001) of the low-reflection layer 4 is, for example, 1.0 nm to 15000 nm, preferably 100 nm to 5000 nm.

[0101] Examples of materials for the low-reflection layer 4 include resin compositions, metals, and their oxides.

[0102] The resin composition contains a resin, a dye, and a filler. In other words, if the material of the low-reflection layer 4 is a resin composition, then the low-reflection layer 4 contains a resin, a dye, and a filler.

[0103] Examples of resins include acrylic resins, epoxy resins, polyimides, and polyamides. Preferably, the resin is an acrylic resin.

[0104] The resin content in the resin composition is, for example, 20% to 80% by mass, preferably 30% to 70% by mass.

[0105] Examples of pigments include black pigments and gray pigments. Preferably, black pigments are used as pigments. Examples of black pigments include black pigments and black dyes. Examples of black pigments include carbon black and titanium-based pigments. Examples of black dyes include mixtures of dyes such as phthalocyanine blue, phthalocyanine green, monoazo yellow, disazo yellow, benzimidazolon yellow, quinacridone red, monoazo red, boriazo red, and beryllene red. More preferably, black pigments are used as pigments. Even more preferably, carbon black is used as a pigment.

[0106] The pigment content in the resin composition is, for example, 0.1% to 20% by mass, preferably 0.5% to 10% by mass.

[0107] Furthermore, the pigment content is, for example, 1 to 50 parts by mass, preferably 5 to 30 parts by mass, per 100 parts by mass of resin.

[0108] Examples of fillers include acrylic microgels and silica. Preferably, acrylic microgels are used as fillers.

[0109] The average particle size of the filler is measured by laser diffraction scattering and is, for example, 1.0 μm or larger, preferably 5.0 μm or larger, and for example, 20.0 μm or smaller.

[0110] The filler content in the resin composition is, for example, 1% to 50% by mass, preferably 5% to 30% by mass.

[0111] The proportion of the filler is, for example, 5 to 50 parts by mass, preferably 10 to 40 parts by mass, per 100 parts by mass of resin.

[0112] Furthermore, as will be explained in more detail later, in the fourth step, when the low-reflectance layer 4 is placed by electrodeposition coating, the low-reflectance layer 4 includes the material of the metal layer M3.

[0113] Examples of metals and their oxides include titanium, nickel, chromium, niobium, and their oxides.

[0114] <Manufacturing method for light-shielding material> An embodiment of a method for manufacturing a light-shielding member will be described with reference to Figures 4A to 4F.

[0115] The method for manufacturing the light-shielding member 1 comprises a first step of preparing a resin layer 3, a second step of arranging a core layer 2 on one side of the resin layer 3 in the thickness direction, a third step of covering the core layer 2 with the resin layer 3, and a fourth step of covering the resin layer 3 with a low-reflection layer 4.

[0116] [1st step] In the first step, the resin layer 3 is prepared as shown in Figure 4A. Specifically, in order to prepare the resin layer 3, the base material M1 is prepared first.

[0117] The substrate M1 is made of a metal that can be removed by etching. Examples of materials for the substrate M1 include stainless steel.

[0118] Next, a resin layer 3 is placed on one side of the substrate M1 in the thickness direction. If the material of the resin layer 3 is a photosensitive resin, a solution (varnish) of the material of the resin layer 3 is applied to one side of the substrate M1 in the thickness direction to obtain a coating film, and then the coating film is exposed to light and developed. This places a resin layer 3 on one side of the substrate M1 in the thickness direction. If the material of the resin layer 3 is not a photosensitive resin (i.e., a non-photosensitive resin), the resin layer 3 is placed by printing a solution (varnish) of the material of the resin layer 3.

[0119] [Second process] In the second step, as shown in Figure 4B, the core layer 2 is placed on one side of the resin layer 3 in the thickness direction. Specifically, first, a seed layer M2 is formed on one side of the resin layer 3 in the thickness direction by sputtering. Examples of materials for the seed layer M2 include chromium, copper, nickel, titanium, and alloys thereof. The seed layer M2 can be a single layer or multiple layers.

[0120] Next, as shown in Figure 4C, first, a resist R with an opening for the formation of the core layer 2 is placed on one side in the thickness direction of the substrate M1. The core layer 2 is then placed on one side in the thickness direction of the seed layer M2 exposed from the resist R by electroplating. The plating method ensures that the core layer 2 is reliably placed.

[0121] [3rd step] In the third step, as shown in Figure 4D, the core layer 2 is covered with a resin layer 3. Specifically, the first main surface 21 of the core, the second main surface 22 of the core, the outer circumferential surface 23 of the core, and the inner circumferential surface 25 of the core are covered with the resin layer 3. The method for covering the first main surface 21 of the core, the second main surface 22 of the core, the outer circumferential surface 23 of the core, and the inner circumferential surface 25 of the core with the resin layer 3 is the same as in the first step described above.

[0122] Subsequently, the substrate M1 is removed by etching. In Figure 4D, the core layer 2 and the seed layer M2 are integrated to form the core layer 2.

[0123] [4th step] In the fourth step, as shown in Figure 4E, the resin layer 3 is covered with a low-reflection layer 4. Specifically, the first main surface 31 of the resin, the second main surface 32 of the resin, the outer surface 33 of the resin, and the inner surface 35 of the resin are covered with the low-reflection layer 4.

[0124] Methods for coating the first resin main surface 31, the second resin main surface 32, the resin outer peripheral surface 33, and the resin inner peripheral surface 35 with a low-reflectance layer 4 include, for example, electrodeposition coating, physical vapor deposition, and plating (for example, electroplating).

[0125] When the material of the low-reflection layer 4 is a resin composition, electrodeposition coating is preferably selected as the coating method. When the material of the low-reflection layer 4 is a metal or its oxide, physical vapor deposition is preferably selected as the coating method.

[0126] In the electrodeposition coating method, the resin layer 3 is first coated with a metal layer M3. Specifically, the first main surface 31 of the resin, the second main surface 32 of the resin, the outer surface 33 of the resin, and the inner surface 35 of the resin are coated with the metal layer M3.

[0127] Examples of materials for the metal layer M3 include chromium, nickel, titanium, copper, nickel-chromium, tungsten, cobalt, and alloys thereof.

[0128] The metal layer M3 material can be used alone or in combination of two or more types.

[0129] Methods for coating the metal layer M3 include, for example, physical vapor deposition and electroless plating.

[0130] Examples of physical vapor deposition methods include vacuum deposition, sputtering, and ion plating. Sputtering is preferred as the physical vapor deposition method.

[0131] The metal layer M3 is, for example, 1 nm to 1000 nm, preferably 10 nm to 500 nm. If the thickness of the metal layer M3 is greater than or equal to the lower limit mentioned above, the adhesion between the resin layer 3 and the low-reflection layer 4 can be improved.

[0132] The metal layer M3 can be a single layer or a multilayer.

[0133] Next, as shown in Figure 4F, the resin layer 3 is coated with a low-reflectance layer 4 via a metal layer M3 by electrodeposition coating. Specifically, the first main surface 31 of the resin, the second main surface 32 of the resin, the outer surface 33 of the resin, and the inner surface 35 of the resin are coated with the low-reflectance layer 4 via the metal layer M3. In Figure 4F, the metal layer M3 is included and referred to as the low-reflectance layer 4.

[0134] The light-shielding member 1 is manufactured as described above.

[0135] In addition, in the physical vapor deposition method (preferably the sputtering method), the material for the low-reflection layer 4 is used as a vapor deposition source to form the low-reflection layer 4 that covers the resin layer 3.

[0136] The light-shielding member 1 is manufactured as described above.

[0137] 2. Effects In the light-shielding member 1, the area of ​​the core layer 2 in a plan view is 85% or less of the area of ​​the light-shielding member 1 in a plan view. Therefore, weight reduction can be achieved.

[0138] 3. Variant In the modified examples, components and processes similar to those in one embodiment are given the same reference numerals, and their detailed descriptions are omitted. Furthermore, the modified examples can achieve the same effects and advantages as the first embodiment, unless otherwise specified. Moreover, the first embodiment and the modified examples can be combined as appropriate.

[0139] (Example of light-shielding member 1) In the above description, the core layer 2 comprises a through-hole peripheral portion 26 and a main bone portion 27A. However, as shown in Figure 5A, the core layer 2 may also further comprise a secondary bone portion 28A extending from the main bone portion 27A in a direction intersecting the direction in which the main bone portion 27A extends (short axis direction). Specifically, the secondary bone portion 28A extends from the main bone portion 27A in one direction along the short axis and in the other direction along the short axis.

[0140] The auxiliary bone portion 28A can improve mechanical strength.

[0141] (Second modified example of the light-shielding member) As shown in Figure 5B, the auxiliary bone portions 28A may be arranged in multiples at intervals in the direction in which the main bone portion 27A extends.

[0142] This configuration allows for further improvement of mechanical strength.

[0143] (Third modified example of the light-shielding material) As shown in Figure 5C, the core layer 2 may further include a main bone portion 27B extending from the perforated portion 26 of the through hole to the opposite side of the through hole 14 relative to the perforated portion 26 (the other side in the long axis direction of the light-shielding member 1 (i.e., the opposite side of the main bone portion 27A)), a secondary bone portion 28B extending from the main bone portion 27B in a direction intersecting the direction in which the main bone portion 27B extends (one side in the short axis direction and the other side in the short axis direction), and a main bone portion 27C extending from the perforated portion 26 of the through hole to the opposite side of the through hole 14 relative to the perforated portion 26 (one side in the short axis direction and the other side in the short axis direction of the light-shielding member 1).

[0144] This configuration allows for even greater improvement in mechanical strength.

[0145] (Fourth modified example of the light-shielding material) As shown in Figure 5D, the core layer 2 may further include a frame portion 29 that is continuous with the ends of the main bone portion 27A, the ends of the main bone portion 27B, the ends of the main bone portion 27C, the ends of the secondary bone portion 28A, and the ends of the secondary bone portion 28B. The frame portion 29 has a substantially elliptical ring shape in plan view.

[0146] This configuration allows for a particularly significant improvement in mechanical strength.

[0147] (Fifth modified example of the light-shielding material) As shown in Figure 5E, the core layer 2 may also have a similar shape to the light-shielding member 1 and have a plurality of core sub-through holes 30 that penetrate in the thickness direction.

[0148] The core sub-through hole 30 allows for a reduction in the weight of the light-shielding member 1.

[0149] The inner diameter of the core sub-through hole 30 is smaller than that of the core main through hole 24.

[0150] The inner diameter of the core sub-through hole 30 is, for example, 1 μm to 500 μm, preferably 10 μm to 100 μm.

[0151] The ratio of the inner diameter of the main core through-hole 24 to the inner diameter of the sub-core through-hole 30 is, for example, 0.01 to 0.5, preferably 0.01 to 0.1.

[0152] The number of core sub-through holes 30 is not limited and can range from, for example, 10 to 1,000,000.

[0153] The arrangement of the core sub-through holes 30 is not particularly limited, but is preferably arranged regularly (for example, in a straight line or staggered pattern).

[0154] This configuration allows for weight reduction while suppressing the irregular decrease in mechanical strength.

[0155] (Sixth modification of the light-shielding material) In the above description, the core layer 2 comprises a through-hole peripheral portion 26 and a main frame portion 27A. However, as shown in Figure 5F, the core layer 2 may also consist only of the through-hole peripheral portion 26 without the main frame portion 27A.

[0156] This configuration allows for even greater weight reduction.

[0157] (Variations in the manufacturing method of light-shielding material) A modified example of the method for manufacturing the light-shielding member will be explained with reference to Figures 6A to 6D.

[0158] The method for manufacturing the light-shielding member 1 comprises a fifth step of preparing a core layer 2, a sixth step of covering the core layer 2 with a resin layer 3, and a seventh step of covering the resin layer 3 with a low-reflection layer 4.

[0159] [5th ​​step] In the fifth step, as shown in Figure 6A, the core layer 2 is prepared. To prepare the core layer 2, first, a substrate M made of the material for the core layer 2 described above is prepared. Next, as shown in Figure 6B, the substrate M is etched to prepare the core layer 2. Specifically, the area where the core layer 2 will be formed is covered with an etching resist, and the substrate M exposed from the etching resist is removed by etching. This prepares the core layer 2.

[0160] [6th step] In the sixth step, as shown in Figure 6C, the core layer 2 is covered with the resin layer 3. Specifically, the first main surface 21 of the core, the second main surface 22 of the core, the outer circumferential surface 23 of the core, and the inner circumferential surface 25 of the core are covered with the resin layer 3. The method for covering the core layer 2 with the resin layer 3 is the same as in the first step described above.

[0161] [Step 7] In the seventh step, as shown in Figure 6D, the resin layer 3 is covered with a low-reflection layer 4. Specifically, the first main surface 31 of the resin, the second main surface 32 of the resin, the outer surface 33 of the resin, and the inner surface 35 of the resin are covered with the low-reflection layer 4. The method for covering the resin layer 3 with the low-reflection layer 4 is the same as in the fourth step described above.

[0162] The light-shielding member 1 is manufactured as described above.

[0163] Furthermore, in the above explanation, the core layer 2 is prepared by etching the substrate M, which is made of the material for the core layer 2. However, the core layer 2 can also be prepared by placing the core layer 2 on the substrate M according to the same procedure as in the second step above, and then removing the substrate M by etching.

[0164] As shown in Figure 7A, the light-shielding member 1 may also be provided with a guide groove 40 that penetrates in the thickness direction. The guide groove 40 is a through hole that penetrates in the thickness direction. The guide groove 40 ensures accurate rotational movement of the light-shielding member 1. The shape of the guide groove 40 is appropriately selected based on the rotational direction of the light-shielding member 1. In Figure 7, the guide groove 40 is positioned away from the through hole 14 in the longitudinal direction. The guide groove 40 has a circular arc shape in plan view that shares the center of the through hole 14.

[0165] Furthermore, as shown in Figure 7B, if the light-shielding member 1 includes a guide groove 40, the core layer 2 may also include a through-hole peripheral portion 26 arranged around the through-hole 14 when viewed from the thickness direction, and a guide groove peripheral portion 41 (through-hole peripheral portion arranged around the through-hole) arranged around the guide groove 40. The guide groove peripheral portion 41 has a circular arc shape in plan view that shares the center of the through-hole 14.

[0166] The guide groove periphery 41 improves the mechanical strength of the guide groove periphery 41. In particular, when the guide groove 40 ensures the rotational movement of the light-shielding member 1, mechanical strength is required around the guide groove 40. On the other hand, by improving the mechanical strength of the guide groove periphery 41, the mechanical strength around the guide groove 40 can be improved.

[0167] In Figure 7B, the core layer 2 includes a through-hole peripheral portion 26 and a guide groove peripheral portion 41, but either the through-hole peripheral portion 26 or the guide groove peripheral portion 41 may be included.

[0168] In the above description, the light-shielding member 1 is composed of a core layer 2, a resin layer 3, and a low-reflection layer 4, but the configuration of the light-shielding member 1 is not limited to the above embodiment. The light-shielding member 1 may include components other than the core layer 2, the resin layer 3, and the low-reflection layer 4. For example, the light-shielding member 1 may have an adhesion layer disposed between the core layer 2 and the resin layer 3 and / or between the resin layer 3 and the low-reflection layer 4.

[0169] Furthermore, in the above description, the resin layer 3 covers the first main surface 21 of the core, the second main surface 22 of the core, the outer circumferential surface 23 of the core, and the inner circumferential surface 25 of the core, and the low-reflection layer 4 covers the first main surface 31 of the resin, the second main surface 32 of the resin, the outer circumferential surface 33 of the resin, and the inner circumferential surface 35 of the resin. However, at a minimum, the resin layer 3 should cover the first main surface 21 of the core, the second main surface 22 of the core, and the outer circumferential surface 23 of the core, and the low-reflection layer 4 should cover the first main surface 31 of the resin, the second main surface 32 of the resin, and the outer circumferential surface 33 of the resin. In other words, the resin layer 3 does not have to cover the inner circumferential surface 25 of the core, and the low-reflection layer 4 does not have to cover the inner circumferential surface 35 of the resin layer 3, or the resin layer 3 does not have to cover the inner circumferential surface 25 of the core, and the low-reflection layer 4 does have to cover the inner circumferential surface 25 of the core, and neither the resin layer 3 nor the low-reflection layer 4 has to cover the inner circumferential surface 25 of the core.

[0170] Furthermore, the light-shielding member 1 may not include the resin layer 3, but may be composed of a core layer 2 and a low-reflection layer 4.

[0171] Furthermore, although the light-shielding member 1 has a substantially elliptical shape in plan view as described above, the shape of the light-shielding member 1 is not particularly limited and can be changed as appropriate depending on the application and purpose. [Explanation of symbols]

[0172] 1. Light-shielding member 2 Core Layers 3. Resin layer 4 Low reflective layer 14 Through holes 26 Periphery of the through hole 27A, 27B, 27C Main bone part 28A, 28B accessory bones 30 Core secondary through holes

Claims

1. A light-shielding member comprising a metal core layer and a low-reflection layer covering the core layer, The area of ​​the core layer in plan view is 85% or less of the area of ​​the light-shielding member in plan view. A light-shielding member wherein the 5° specular reflectance of the low-reflectance layer is lower than the 5° specular reflectance of the core layer.

2. The light-shielding member according to claim 1, wherein the external shape of the core layer is dissimilar to the external shape of the light-shielding member.

3. The light-shielding member has a through hole that penetrates in the thickness direction, The light-shielding member according to claim 1, wherein the core layer comprises a peripheral portion of the through-hole that is arranged around the through-hole when viewed in the thickness direction.

4. The light-shielding member according to claim 3, wherein the core layer comprises a main rib portion extending from the periphery of the through-hole to the opposite side of the through-hole with respect to the periphery of the through-hole.

5. The light-shielding member according to claim 4, wherein the core layer comprises a secondary bone portion extending from the main bone portion in a direction intersecting the direction in which the main bone portion extends.

6. The light-shielding member according to claim 5, wherein the auxiliary bone portions are arranged in a plurality at intervals in the direction in which the main bone portion extends.

7. The light-shielding member according to claim 3, wherein the core layer has a plurality of core sub-through holes penetrating in the thickness direction.

8. The light-shielding member according to claim 7, wherein a plurality of the core sub-through holes are arranged regularly.

9. Furthermore, the light-shielding member according to any one of claims 1 to 8, comprising a resin layer disposed between the core layer and the low-reflection layer.

Images