| 摘要 |
<p>For displaying graphic information, in particular for braille reading, the invention employs small magnetizable balls (38) which are very rapidly patterned on an indented or perforated support (20) so as to partly project therefrom underneath a foil (70) holding the balls against falling out, whereupon the support is moved to a reading plane. Preferably, a lower feeding station (40) distributes balls into all perforations (22) of the support; the balls not required for the desired display are then sucked off in an upper removal station (50) by electromagnets (52) set off in an array aligned with staggered apertures in an upper plate (62). Short-time actuation of selected electromagnets is coordinated with the support motion under electronic control which may provide for time-multiplexed interleaving. A preferred embodiment includes two drums (30, 32) with sprocket wheels (28) arranged to pull a web-like endless belt band (20) with its foil (70) across frame plate (14, 16) of the device (10).</p> |
