Three-dimensional display, authentication medium, and formation method

A three-dimensional display in which a first contour region surrounding a recorded first character, and a second contour region surrounding a recorded second character are arranged on a laminate sheet, wherein

• a plurality of first element cells in which personal identification information is recorded and a plurality of second element cells carrying an authentication medium through which the personal identification information is visible are arranged in the first contour region and in the second contour region to form respective phase shift structures;
• wherein:
• in the first contour region and in the second contour region, the first element cells and the second element cells are arranged in an interleaved manner at a predetermined ratio to form respective three-dimensional structures;
• the first contour region and the second contour region are visible respectively from first and second sides of the laminate sheet;
• a reconstructed image derived from the second contour region is produced on the first side of the laminate sheet, at a position apparently separated from the laminate sheet, due to the phase shift structure formed by the first element cells;
• and
• a reconstructed image derived from the first contour region is produced on the second side of the laminate sheet, at a position apparently separated from the laminate sheet, due to the phase shift structure formed by the second element cells.