| 摘要 |
PURPOSE: To provide a display board whose view is changed depending on a viewing direction. CONSTITUTION: This display board is provided with at least two pieces of optical sheets 1 and 2 constituted of a transparent sheet composed by forming many parallel prism shapes on one surface for totally reflecting or transmitting incident light depending on the incident angle of the incident light made incident on the prism formation surface or the surface on the opposite side of the prism formation surface. The at least two pieces of the optical sheets 1 and 2 are arranged side by side or piled up while turning the prism formation surfaces in mutually opposite directions and a pattern to be displayed is formed by at least one piece of the optical sheet 1 of at least two pieces of the optical sheets 1 and 2.
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