Optical body, display device, and method for manufacturing optical body

A method for manufacturing an optical body, comprising:

• a step of forming a second concave-convex structure whose average concave-convex period is less than or equal to a wavelength in a visible light region on a surface of a base material;
• a step of forming a resist layer on the surface of the base material on which the second concave-convex structure is formed;
• a step of forming a first concave-convex structure on a surface of the resist layer;
• and
• a step of superimposing the first concave-convex structure and the second concave-convex structure on the surface of the base material by etching with perpendicular anisotropy.

An optical body comprising:

• a first concave-convex structure formed on a surface of a base material;
• and
• a second concave-convex structure superimposed on the first concave-convex structure, wherein
• an average concave-convex period of the first concave-convex structure is larger than a wavelength in a visible light region,
• an average concave-convex period of the second concave-convex structure is less than or equal to the wavelength in the visible light region, and
• projecting parts of the second concave-convex structure extend in a direction normal to a flat plane of the base material,
• wherein the projecting parts of the second concave-convex structure include
• a peak-side projecting part in a peak part of the first concave-convex structure,
• a valley side projecting part in a valley part of the first concave-convex structure, and
• an intermediate projecting part in a slope part between the peak part and the valley part of the first concave-convex structure, and
• wherein a height of the intermediate projecting part is smaller than a height of the peak-side projecting part and the valley-side projecting part.