Optical element and method for manufacturing optical element
An optical element with an antireflection function is provided with a substrate having a surface and a plurality of structures formed from convex portions or concave portions and arranged in large numbers on the surface of the substrate with a minute pitch less than or equal to the wavelength of the visible light, wherein the modulus of elasticity of the material forming the structures is 1 MPa or more, and 1,200 MPa or less, and the aspect ratio of the structure is 0.6 or more, and 1.5 or less.
1. An optical element with an antireflection function, the optical element comprising:
a substrate having a surface;
a plurality of elongate structures formed from convex portions or concave portions, arranged in large numbers on the surface of the substrate with a minute pitch less than or equal to a wavelength of the visible light, and arranged in offset tracks, each track extending in a first direction corresponding to a direction of elongation of the elongate structures; and
a surface-treated layer disposed on the elongate structures, the surface-treated layer including a compound containing a silicon-based compound and a fluorine-containing compound,
wherein elongate structures in adjacent tracks form lines that extend in a second direction transverse to the first direction,
each of the elongate structures has a first height at a cross-section in the first direction and a second height at a cross-section in the second direction,
the first height is less than the second height,
the modulus of elasticity of the material forming the elongate structures is 1 MPa or more, and 1,200 MPa or less,
an aspect ratio of the elongate structures is 0.6 or more, and 1.5 or less, and
a filling factor of the elongate structures is 65% or more.
2. The optical element according to claim 1 , wherein a contact angle of oleic acid on the surface of the substrate provided with the surface-treated layer is 30 degrees or more.
3. The optical element according to claim 2 , wherein the contact angle of oleic acid on the surface of the substrate provided with the surface-treated layer is 50 degrees or more.
4. The optical element according to claim 1 , wherein the tracks form a hexagonal lattice pattern, a quasi-hexagonal lattice pattern, a tetragonal lattice pattern, or a quasi-tetragonal lattice pattern, and
the elongate structures are in the shape of an elliptical cone or an elliptical truncated cone, which have a major axis direction in an extension direction of the tracks.
5. The optical element according to claim 4 , wherein the tracks have the shape of a straight line or the shape of an arc.
6. The optical element according to claim 4 , wherein the tracks meander.
7. The optical element according to claim 1 , wherein the tracks form a quasi-hexagonal lattice pattern, and
a height or depth of the elongate structures in an extension direction of the tracks is smaller than a height or depth of the elongate structures in a direction of lines of the tracks.
8. The optical element according to claim 1 , wherein the tracks form a tetragonal lattice pattern or a quasi-tetragonal lattice pattern, and
a height or depth of the structures in an arrangement direction slanting with respect to an extension direction of the tracks is smaller than a height or depth of the structures in the extension direction of the tracks.
9. The optical element according to claim 1 , wherein an arrangement pitch PI of the elongate structures in the same track is larger than an arrangement pitch P2 of the elongate structures between adjacent two tracks.
10. The optical element according to claim 1 , wherein the optical element is included in a display device.
11. The optical element according to claim 1 , wherein a ratio of a diameter of bottoms of the elongate structures to an arrangement pitch of the bottoms of the elongate structures is 85% or more.
12. An optical element with an antireflection function, the optical element comprising:
a plurality of elongate structures formed from convex portions, arranged in large numbers with a minute pitch less than or equal to a wavelength of the visible light, and arranged in offset tracks, each track extending in a first direction corresponding to a direction of elongation of the structures; and
a surface-treated layer disposed on the elongate structures, the surface-treated layer including a compound containing a silicon-based compound and a fluorine-containing compound,
wherein elongate structures in adjacent tracks form lines that extend in a second direction transverse to the first direction,
each of the elongate structures has a first height at a cross-section in the first direction and a second height at a cross-section in the second direction,
the first height is less than the second height,
lower portions of adjacent elongate structures are mutually joined,
the modulus of elasticity of the material forming the elongate structures is 1 MPa or more, and 1,200 MPa or less,
an aspect ratio of the elongate structures is 0.6 or more, and 1.5 or less, and
a filling factor of the elongate structures is 65% or more.
13. An optical element with an antireflection function, the optical element comprising:
a substrate having a surface;
a plurality of elongate structures formed from convex portions or concave portions, arranged in large numbers on the surface of the substrate with a minute pitch less than or equal to a wavelength of the visible light, arranged in offset tracks, each track extending in a first direction corresponding to a direction of elongation of the structures; and
a surface-treated layer disposed on the elongate structures, the surface-treated layer including a compound containing a silicon-based compound and a fluorine-containing compound,
wherein elongate structures in adjacent tracks form lines that extend in a second direction transverse to the first direction,
each of the elongate structures has a first height at a cross-section in the first direction and a second height at a cross-section in the second direction,
the first height is less than the second height,
the modulus of elasticity of the material forming the elongate structures is 1 MPa or more, and 1,200 MPa or less,
an aspect ratio of the elongate structures is 0.6 or more, and 5 or less, and
a filling factor of the elongate structures is 65% or more.
14. The optical element according to claim 13 , wherein the modulus of elasticity of the material forming the substrate is 1 MPa or more, and 3,000 MPa or less.
15. The optical element according to claim 14 , wherein the thickness of the substrate is 60 μm or more.
16. The optical element according to claim 13 ,
wherein the substrate has a layer structure composed of at least two layers, and
the modulus of elasticity of a base layer disposed adjoining to the elongate structures is 1 MPa or more, and 3,000 MPa or less, among the layer structure composed of at least two layers.
17. The optical element according to claim 16 , wherein the thickness of the base layer is 60 μm or more.
18. The optical element according to claim 13 , wherein the substrate comprises a base layer disposed adjoining to the elongate structures and a base member disposed adjoining to the base layer, and
the moduli of elasticity of the base layer and the base member are 1 MPa or more, and 3,000 MPa or less.
19. The optical element according to claim 18 , wherein the total thickness of the base layer and the base member is 60 μm or more.
20. The optical element according to claim 13 , wherein an elongation percentage of the material forming the elongate structures is 50% or more.
21. The optical element according to claim 13 , wherein an elongation percentage of the material forming the elongate structures is 20% or more.