Braille Display
A braille display is a device which is typically attached to a computer
keyboard, that converts ordinary print or symbols on a computer screen
into an exact "tactile" replica in braille characters
[1]. Each braille
character is made up of six or eight metal or nylon pins in a rectangular
array. The pins on the device rise and fall depending on the electrical
signals they recieve. This simulates the effect of braille characters on
paper [6].
Braille displays are "refreshable", which means that when the
user finishes reading one line of text and moves on to the next, the device
automatically displays the new line in braille
[7]. The size of braille
displays depend mainly on the number of cells they contain. Most commonly,
braille displays have 40 cells, however they can have anywhere from 12 to
84 cells. Braille displays which can be used with mobile devices tend to
have between 12 and 18 cells. Desktop computer braille displays contain 80
to 84 cells, which coincides with the typical length of a microsoft word document
[7].