An alternative to text to speech for computer access. Refreshable braille displays are used by the deafblind or those who do not want an annoying voice droning in their ear for hours on end, and can afford the cost. The average unit is about $4000.
Braille displays consist of one row of cells. Usually there are 40 or 80 cells, but there can be any number. The cells consist of various pins representing the various dots in braille. The pins stick out of small holes on the display to form the dots. Older units used solenoid, but modern units use a piezoelectric system to activate the pins. In addition to the actual display, there are often controls which are used to route the cursor to the current cell, in an effort to make editing easier. Braille displays can be stand alone units that plug into the serial port of a standard computer or included as part of a device such as the BrailleNote.