Abstract: A projection curtain is provided in the present invention. The projection curtain at least comprises a reflective layer and one of a colored layer, a diffusion layer, and a Fresnel lens layer. The Fresnel lens layer is a spherical Fresnel lens layer or an aspherical Fresnel lens layer. The Fresnel lens layer comprises a plurality of annular protrusions protruding from a plane, the plurality of annular protrusions are arranged in circular bands. A cross-sectional shape of each annular protrusion along a cross section perpendicular to the plane is a triangular shape or a multi-step shape or a free surface shape. The width of one side of each cross-sectional shape parallel to the plane gradually changes, and gradual change of the cross-sectional shape and the width thereof determines light gathering characteristics of the spherical Fresnel lens layer or the aspherical Fresnel lens layer. A surface of each annular protrusion has scattered microstructures.

Abstract: A preparation method (100) for a three-dimensional micro-nano morphological structure manufactured by a laser direct writing lithography machine, comprising: step 110, providing a three-dimensional model diagram; step 120, dividing the three-dimensional model diagram in a height direction to obtain at least one height interval; and step 130, projecting the three-dimensional model diagram onto a plane to obtain a mapping relationship, wherein the mapping relationship comprises coordinates, on the plane, corresponding to each point on the three-dimensional model diagram, and wherein the height of each point on the three-dimensional model diagram corresponds to a height value in a corresponding height interval; and making the mapping relationship correspond to an exposure dose according to the mapping relationship, and performing lithography on the basis of the exposure dose. Any three-dimensional micro-nano morphological structure can be obtained.