摘要 |
<p>An elementary cell combinable to form dot matrix displays, in which a plurality of plates of non-magnetic insulating material, at least one of which is in contact with a plate of high magnetic permeability, define a seat for housing a polychrome sphere provided internally with a permanent magnet. In the plates of non-magnetic material there are arranged magnetic poles, which can be energized selectively to cause the sphere to rotate into predetermined positions. <IMAGE></p> |