braille display
refreshable braille display
refreshable display

    (Or "refreshable braille display", "refreshable
   display") An electromechanical device that renders braille
   with tiny, independently controlled pins used to represent the
   state of dots in braille cells.  Each pin, in its "on" state,
   raises above the top of its hole in the screen; in its "off"
   state, it drops below the top of its hole.  Older systems used
   tiny solenoids to control the state of the pins; modern
   systems are piezoelectric.

   Typical dimensions of a braille display are 1 line of 40
   cells, each cell of two-by-eight dots.

   (1998-10-19)