摘要 |
A triangular-pyramidal cube-corner retroreflective sheeting characterized in that a lateral face (prism face) (face c) using a base edge (x) of triangular-pyramidal reflective elements faced each other and arranged in the closest-packed state by sharing the base edge (x) on a base plane (X-X') as one side is hexagonal or triangular, two other faces (faces a and b) sharing one ridge line starting with an apex (H) of the triangular-pyramidal reflective elements is quadrangular and when assuming the height from the apex (H) up to the base plane (X-X') as (h) and the height up to a substantially horizontal plane (Z-Z') including base edges (z and w) of other two faces (faces a and b) as (h0), and the angle formed between the optical axis of the triangular-pyramidal reflective elements and a plane (Y-Y') including the base edge (x) and vertical to the base plane (X-X') as (theta), h and h0 are not substantially equal to each other but h/h0 and theta meet a specific relational expression.
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