Device for forming braille tactile display

Abstract

A device for forming a tactilely readable display including Braille characters includes a planar display carrier wherein consisting essentially of a belt of flexible material which forms a closed loop and revolves about two rotating rolls. Circular openings are provided on an outer side of the belt loop, the inner side of the belt being provided with a multiplicity of recesses communicating with respective openings in the outer side of the belt. A steel ball may be lodged in each of the recesses, a portion of each ball protruding through the associated opening to form a spherical raster dot on the outer side of the belt. An upper portion of the belt passes over a contact plate, which forms a reading zone of the Braille display device, while a lower portion of the loop passes through a steel ball container in which all of the recesses become occupied by a respective ball. At a ball selection at an upstream end of the contact plate, as defined by the motion of the belt, an electromagnetically actuated selection device is disposed above the upper end of a guide channel extending downwardly from the selection station to the ball container. The selection device selectively retains steel balls in the recesses of the belt during the passage thereof over the guide channel at the selection station. Unretained steel balls fall back into the container via the guide channel.