US Patent 7852557 Stereoscopic sheet structure

An object of the present invention is to provide a stereoscopic sheet structure in which a three-dimensional design appears to be changing by changing the angle of observation, the stereoscopic sheet structure being a stereoscopic sheet structure that has: a convex lens assembly which is formed on one surface of a sheet member and in which a plurality of convex lenses are arranged; and a repeating design portion in which a plurality of design units are arranged on a focal plane of the convex lenses at arrangement intervals and/or in arrangement directions different from those of the convex lenses, and which has a continuously deformed design portion in which the arrangement intervals and arrangement directions of the design units regularly change while satisfying the condition of 0.95≦DN˜N+1/DN+1˜N+2≦0.95 and −1≦θ≦+1. It should be noted that the D is an interval between adjacent design elements, and the θ is an intersection angle that is formed between a straight line connecting adjacent design elements and a straight line connecting one of the adjacent design elements to a design element adjacent thereto.