摘要 |
<p>The invention provides a panel (2) of controllable radiation transmissivity, including a plurality of tubular cells (4), in at least some of which cells is rotatably mounted at least one radiation-blocking member (6), at least one portion of at least one surface of which is substantially opaque, and means (8) for rotating the radiation-blocking member (6) inside the tubular cells (4), wherein the radiation-blocking member (6), when rotated, is adapted, in at least one angular position, to substantially block the passage of radiation through the panel (2), and in a plurality of other, selectable, angular positions, to provide a plurality of differing radiation transmissivities.</p> |