| 摘要 |
<p>The invention concerns cathode ray tubes with substantially planar front surface, whereof the colour selecting mask is produced by swaging. The mask (9) comprises an active surface (19) enclosed by a solid peripheral edge (28) terminated by a skirt (17) substantially perpendicular to the active surface. In order to rigidify the active surface in a direction parallel to the main axis, the mean radius of curvature (Rse) of said active surface is greater than the mean radius of curvature (Rbp) of the peripheral edge.</p> |
