| 摘要 |
A panel for a screen, said panel comprising a plurality of groups of perforations, each group comprising six generally equal triangular apertures (513, 514, 515) arranged with their apices facing a central portion (550), wherein the apices of two (514, 515) opposing ones of said triangular apertures are spaced apart further than the apices of opposed ones of the remaining triangular apertures (513, 513; 513, 513). <IMAGE> |
