| 摘要 |
The board, which aims at improving visibility and safety conditions, comprises a viewing surface oriented towards an onlooker (U), said viewing surface being made discontinuous with the presence in it of through openings (7, 9; 7a, 9a) that allow the passage of a current of air incident on the board (1; 1a; 1b; 1c; 1d) and channelled in such a way as to prevent any light from behind passing through to the onlooker (U) positioned in front of the viewing surface. |
