Optical phase difference component, composite optical component, incorporating optical phase difference component, and method for manufacturing optical phase difference component

1. An optical phase difference component, comprising:

a transparent base which has a substrate and a concave-convex structure layer with a concave-convex pattern;

a coating layer which coats surfaces of concave portions and convex portions of the concave-convex structure layer, thereby forming coated convex portions;

a gap defined between adjacent ones of the coated convex portions; and

a closing layer provided on the coating layer to connect the coated convex portions and to close the gap,

wherein the gap has a height higher than a height of each of the coated convex portions and the closing layer has a varying thickness, with thicker portions corresponding to positions of convex portions and thinner portions corresponding to positions of concave portions.

2. The optical phase difference component according to claim 1 , wherein each of the convex portions of the concave-convex structure layer has a trapezoidal cross-sectional shape.

3. The optical phase difference component according to claim 1 , wherein the coating layer has a refractive index which is greater than that of the convex portions of the concave-convex structure layer.

4. The optical phase difference component according to claim 1 , wherein the coating layer and the closing layer are made of same material.

5. The optical phase difference component according to claim 1 , wherein the coating layer and the closing layer are made of mutually different materials.

6. The optical phase difference component according to claim 1 , wherein the coating layer is made of metal, metal oxide, metal nitride, metal sulfide, metal oxynitride, or metal halide.

7. The optical phase difference component according to claim 1 , wherein the closing layer is made of metal, metal oxide, metal nitride, metal sulfide, metal oxynitride, or metal halide.

8. The optical phase difference component according to claim 1 , wherein the concave-convex structure layer is made of a photo-curable resin or a thermo-setting resin.

9. The optical phase difference component according to claim 1 , wherein the concave-convex structure layer is made of a sol-gel material.

10. The optical phase difference component according to claim 1 , wherein the gap contains air.

11. The optical phase difference component according to claim 1 , further comprising a protective component which adheres to the closing layer and/or a surface, of the transparent base, opposite to a surface with the concave-convex pattern.

12. A composite optical component, comprising:

the optical phase difference component as defined in claim 1 ; and

an optical component adhering to the closing layer or a surface, of the transparent base, opposite to a surface with the concave-convex pattern.

13. The composite optical component according to claim 12 , wherein the optical component is a polarization plate.

14. A display device, comprising:

the composite optical component as defined in claim 12 ; and

a display element adhering to the closing layer or a surface, of the transparent base, opposite to a surface with the concave-convex pattern.

15. A method for manufacturing an optical phase difference component, comprising:

preparing a transparent base having a substrate and a concave-convex structure layer which has a concave-convex pattern and is formed on the substrate;

forming a coating layer which coats surfaces of concave portions and convex portions of the concave-convex structure layer, thereby forming coated convex portions;

forming a closing layer on the coating layer to connect the coated convex portions and to close a gap defined between adjacent ones of the coated convex portions,

wherein the gap has a height higher than a height of each of the coated convex portions and the closing layer has a varying thickness, with thicker portions corresponding to positions of convex portions and thinner portions corresponding to positions of concave portions.

16. The method for manufacturing the optical phase difference component according to claim 15 , wherein, in the forming of the closing layer, the closing layer is formed by sputtering, chemical vapor deposition, or evaporation deposition.

17. The optical phase difference component according to claim 1 , wherein the closing layer is to be joined to another component via adhesive.