摘要 |
A device for forming a tactilely readable message including Braille characters and graphic representations includes a planar display carrier with raised raster dots which are formed by spherical segments protruding selectively through openings in the surface of the display carrier. The display carrier is provided with a multiplicity of recesses arranged in a matrix-like array, the recesses being occupied by respective sensing or reading balls which are selectively movable in the recesses as keying elements for the raster dots. The recesses communicate at a lower end with respective chamber-like enlargements occupied by respective control balls of magnetically soft material which function to alternately position the reading balls in a lowered or in a raised position. The chamber-like enlargements are designed to provide for the control balls a lower stable position and an upper stable position corresponding respectively to the lowered and raised positions of the reading balls. For all the control balls of a matrix row, a resetting device in the form of a comb-liked slide is provided. The placement of the control balls in preselected positions for forming a readable display is accomplished by means of one or more individual magnets acting on the control balls via magnetic bridges designed as pole pieces.
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