Optical body, wall member, fitting, solar shading device, and building
An optical body includes a substrate having a concave-convex surface, a reflecting layer formed on the concave-convex surface, and an optical layer formed on the reflecting layer to embed the concave-convex surface, wherein the reflecting layer directionally reflects light, the concave-convex surface is made up of a plurality of triangular pillars arrayed in a one-dimensional pattern, and the triangular pillar has an apex angle α and a slope angle β, the apex angle α and the slope angle β satisfying a formula (1) or (2) given below: 30≦β≦4.5α−285(70≦α≦80) (1) 30≦β≦−1.5α+195(80≦α≦100) (2).
1. An optical body comprising:
a substrate having a concave-convex surface;
a reflecting layer formed on the concave-convex surface; and
an optical layer formed on the reflecting layer to embed the concave-convex surface,
wherein the reflecting layer directionally reflects all of the incident light regardless of the wavelength band,
the concave-convex surface is made up of a plurality of triangular pillars arrayed in a one-dimensional pattern, and
the triangular pillar has an apex angle α and a slope angle β, the apex angle αand the slope angle β being within an area bounded by lines defined by the following formulae:
β=4.5α−285(where 70≦α≦80)
β=−1.5α+195(where 80≦α≦100) and
β=30.
2. An optical body comprising:
a substrate having a concave-convex surface; and
a reflecting layer formed on the concave-convex surface,
wherein the reflecting layer directionally reflects all of the incident light regardless of the wavelength band,
the concave-convex surface is made up of a plurality of triangular pillars arrayed in a one-dimensional pattern, and
the triangular pillar has an apex angle α and a slope angle β, the apex angle αand the slope angle β being within an area bounded by lines defined by the following formulae:
β=4.5α−285(where 70≦α≦80)
β=−1.5α+195(where 80≦α≦100) and
β=30.
3. The optical body according to claim 1 , wherein the apex angle α and the slope angle β are within an area bounded by lines defined by the following formulae:
β=α−40(where 70≦α≦80)
β≦−α+150(where 80≦α≦100) and
β=30.
4. The optical body according to claim 1 , wherein the triangular pillar has a first sloped surface and a second sloped surface on each of which the reflecting layer is formed, and
film thicknesses of the reflecting layers formed on the first sloped surface and the second sloped surface differ from each other.
5. The optical body according to claim 1 , wherein the triangular pillar has a first sloped surface and a second sloped surface on each of which the reflecting layer is formed, and
film thicknesses of the reflecting layers formed on the first sloped surface and the second sloped surface are substantially equal to each other.
6. The optical body according to claim 1 , wherein the triangular pillars are arrayed at a pitch of 5 μm or larger and 5 mm or smaller.
7. The optical body according to claim 1 , wherein the reflecting layer is a metal layer.
8. The optical body according to claim 7 , wherein the reflecting layer has a reflectance of 30% or more at a wavelength of 1500 nm.
9. The optical body according to claim 1 , further comprising a water-repellent or hydrophilic layer on an incident surface of the optical body.
10. The optical body according to claim 2 , further comprising a protective layer formed on the reflecting layer to follow the concave-convex surface.
11. The optical body according to claim 1 , wherein the optical body has a belt-like or rectangular shape, and
a lengthwise direction of the optical body is orthogonal to a ridgeline direction of the triangular pillar.
12. A wall member including the optical body according to claim 1 .
13. The wall member according to claim 12 , wherein the optical body is arranged such that a ridgeline direction of the triangular pillar is substantially orthogonal to a direction of height of a building.
14. The wall member according to claim 12 , wherein the optical body is arranged such that, in each of the triangular pillars, the slope angle β is positioned above the apex angle α.
15. A fitting including a shading portion provided with the optical body according to claim 1 .
16. A solar shading device comprising one or more solar shading members to cut off sunlight,
wherein the solar shading member includes the optical body according to claim 1 .
17. A building including the optical body according to claim 1 , wherein the optical body is arranged such that, in each of the triangular pillars, the slope angle β is positioned above the apex angle α.