Optical body with suppressed change in color tone and window member, fitting, and solar shading including the optical body
An optical body includes a first optical layer having a concave-convex surface, a wavelength-selective reflecting layer formed on the concave-convex surface, and a second optical layer formed on the wavelength-selective reflecting layer to embed the concave-convex surface, the wavelength-selective reflecting layer having a multilayer structure formed by successively stacking at least a first high refractive index layer, a metal layer, and a second high refractive index layer, wherein, given that optical film thicknesses of the first high refractive index layer and the second high refractive index layer are x and y, respectively, and a geometrical film thickness of the metal layer is z, x, y and z satisfy the following formula (1): z ≤ 12.1 exp { - 1 2 ( x - 120 145.17 ) 2 - 1 2 ( y - 120 123.14 ) 2 } ( 1 )
1. An optical body comprising:
a first optical layer having a concave-convex surface;
a wavelength-selective reflecting layer formed on the concave-convex surface; and
a second optical layer formed on the wavelength-selective reflecting layer to embed the concave-convex surface,
the wavelength-selective reflecting layer having a multilayer structure formed by successively stacking a first high refractive index layer, a metal layer, and a second high refractive index layer,
wherein, given that optical film thicknesses of the first high refractive index layer and the second high refractive index layer are x (nm) and y (nm), respectively, and a geometrical film thickness of the metal layer is z, x, y and z satisfy formula (1) when the refractive indices of the first high refractive index layer and of the second high refractive index layer are measured at a wavelength of 550 nm:
z
≤
12.1
exp
{
-
1
2
(
x
-
120
145.17
)
2
-
1
2
(
y
-
120
123.14
)
2
}
(
1
)
where x and y are each 10 nm or more and 120 nm or less.
2. An optical body comprising:
a first optical layer having a concave-convex surface;
a wavelength-selective reflecting layer formed on the concave-convex surface; and
a second optical layer formed on the wavelength-selective reflecting layer to embed the concave-convex surface,
the wavelength-selective reflecting layer having a multilayer structure formed by successively stacking a first high refractive index layer, a metal layer, and a second high refractive index layer,
wherein, given that optical film thicknesses of the first high refractive index layer and the second high refractive index layer are x (nm) and y (nm), respectively, and a geometrical film thickness of the metal layer is z, x, y and z satisfy formula (2) when the refractive indices of the first high refractive index layer and of the second high refractive index layer are measured at a wavelength of 550 nm:
z
≤
12.2
exp
{
-
1
4
(
x
-
y
62.71
)
2
-
1
2
(
0.70
(
x
+
y
)
-
120
99.41
)
2
}
(
2
)
where x and y each are 10 nm or more and 120 nm or less.
3. The optical body according to claim 1 , wherein x, y and z further satisfy formula (3) when the refractive indices of the first high refractive index layer and of the second high refractive index layer are measured at a wavelength of 550 nm:
z
≤
12.1
exp
{
-
1
2
(
x
-
120
121.57
)
2
-
1
2
(
y
-
120
107.57
)
2
}
(
3
)
where x and y each are 10 nm or more and 120 nm or less.
4. The optical body according to claim 2 , wherein x, y and z further satisfy formula (4) when the refractive indices of the first high refractive index layer and of the second high refractive index layer are measured at a wavelength of 550 nm:
z
≤
11.8
exp
{
-
1
4
(
x
-
y
61.22
)
2
-
1
2
(
0.70
(
x
+
y
)
-
110
97.89
)
2
}
(
4
)
where x and y each are 10 run or more and 120 nm or less.
5. The optical body according to claim 3 , wherein x, y and z further satisfy formula (5) when the refractive indices of the first high refractive index layer and of the second high refractive index layer are measured at a wavelength of 550 nm:
z
≤
9.70
exp
{
-
1
2
(
x
-
120
147.139
)
2
-
1
2
(
y
-
120
121.942
)
2
}
(
5
)
where x and y each are 10 nm or more and 120 nm or less.
6. The optical body according to claim 4 , wherein x, y and z further satisfy formula (6) when the refractive indices of the first high refractive index layer and of the second high refractive index layer are measured at a wavelength of 550 nm:
z
≤
9.72
exp
{
-
1
2
(
0.7
(
x
-
y
)
+
5
50.00
)
2
-
1
2
(
0.70
(
x
+
y
)
-
110
134.16
)
2
}
(
6
)
where x and y each are 10 nm or more and 120 nm or less.
7. An optical body comprising:
a first optical layer having a concave-convex surface;
a wavelength-selective reflecting layer formed on the concave-convex surface; and
a second optical layer formed on the wavelength-selective reflecting layer to embed the concave-convex surface,
the wavelength-selective reflecting layer having a multilayer structure formed by successively stacking a first high refractive index layer, a metal layer, and a second high refractive index layer,
wherein, given that optical film thicknesses of the first high refractive index layer and the second high refractive index layer are x (nm) and y (nm), respectively, and a geometrical film thickness of the metal layer is z, x, y and z satisfy the formulae (1) and (2) when the refractive indices of the first high refractive index layer and of the second high refractive index layer are measured at a wavelength of 550 nm:
z
≤
12.1
exp
{
-
1
2
(
x
-
120
145.17
)
2
-
1
2
(
y
-
120
123.14
)
2
}
(
1
)
z
≤
12.2
exp
{
-
1
4
(
x
-
y
62.71
)
2
-
1
2
(
0.70
(
x
+
y
)
-
120
99.41
)
2
}
(
2
)
where x and y each are 10 nm or more and 120 nm or less.
8. The optical body according to claim 1 , wherein x, y and z satisfy relational expressions of 19.36 nm <x, y <135 nm, 7 nm <z<12 nm.
9. The optical body according to claim 1 , wherein the high refractive index layer contains at least one selected from among a group including niobium oxide, zinc oxide, titanium oxide, and tantalum oxide, and
the metal layer contains a silver alloy.
10. The optical body according to claim 1 , wherein the high refractive index layer has a refractive index of 1.7 or more and 2.6 or less.
11. The optical body according to claim 1 , wherein the wavelength-selective reflecting layer selectively directionally reflects light in a specific wavelength band while transmitting light other than the specific wavelength band therethrough, and
a value of transmission image clarity for the light at wavelengths transmitting through the optical body is 50 or larger when measured in conformity with JIS K-7105 by using an optical comb with a comb width of 0.5 mm.
12. The optical body according to claim 1 , wherein a total value of transmission image clarity for light at wavelengths transmitting through the optical body is 230 or larger when measured in conformity with JIS K-7105 by using optical combs with comb widths of 0.125 mm, 0.5 mm, 1.0 mm and 2.0 mm.
13. The optical body according to claim 1 , wherein the concave-convex surface of the first optical layer is formed by arraying many structures in a one-dimensional pattern or a two-dimensional pattern, and
the structures have a prism-like shape, a lenticular shape, a semispherical shape, or a corner cube shape.
14. The optical body according to claim 1 , wherein the structures are arrayed at a pitch of 5μm or more and 5 mm or less.
15. The optical body according to claim 1 , wherein a difference in refractive index between the first optical layer and the second optical layer is 0.010 or less.
16. The optical body according to claim 1 , wherein the first optical layer and the second optical layer are made of a same resin having transparency in a visible range, and the second optical layer contains one or more additives.
17. The optical body according to claim 1 , further comprising a water-repellent or hydrophilic layer on an incident surface of the optical body.
18. The optical body according to claim 1 , wherein the optical body directionally reflects light in a specific wavelength band to prevent the light in the specific wavelength band from entering a predetermined space, while transmitting light other than the specific wavelength band therethrough to be taken into the predetermined space.
19. A window member comprising the optical body according to claim 1 affixed to a rigid member having transparency.
20. A fitting comprising a lighting portion provided with the optical body according to claim 1 and a frame member that is disposed in a peripheral portion of the optical body.
21. A solar shading device capable of adjusting a degree at which a solar shading member cuts off incident light, by winding or unwinding the solar shading member, or capable of adjusting a degree at which a group made up of plural solar shading members cuts off the incident light, by changing an angle of the solar shading member group,
wherein the solar shading member comprises the optical body according to claim 1 .
22. The optical body according to claim 1 , further comprising a compound containing phosphoric acid in at least one of the first optical layer and the second optical layer.
23. The optical body according to claim 2 , further comprising a compound containing phosphoric acid in at least one of the first optical layer and the second optical layer.
24. The optical body according to claim 7 , further comprising a compound containing phosphoric acid in at least one of the first optical layer and the second optical layer.
25. The optical body according to claim 1 , wherein the wavelength-selective reflecting layer having a multilayer structure formed by successively stacking only a first high refractive index layer, a metal layer, and a second high refractive index layer.