(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.