Slate and stylus
Overview
 
The slate and stylus are tools used by blind
Blindness
Blindness is the condition of lacking visual perception due to physiological or neurological factors.Various scales have been developed to describe the extent of vision loss and define blindness...

 persons to write text that they can read without assistance. Invented by Charles Barbier
Charles Barbier
Charles Barbier de la Serre was the creator of night writing.Charles Barbier de la Serre was a Captain in the French Army during the early 19th century. "Ecriture Nocturne" was invented in response to Napoleon's demand for a code that soldiers could use to communicate silently and without light at...

 and Louis Braille
Louis Braille
Louis Braille was the inventor of braille, a system of reading and writing used by people who are blind or visually impaired...

 as the tool for "writing" Braille
Braille
The Braille system is a method that is widely used by blind people to read and write, and was the first digital form of writing.Braille was devised in 1825 by Louis Braille, a blind Frenchman. Each Braille character, or cell, is made up of six dot positions, arranged in a rectangle containing two...

, the slate and stylus allow for a quick, easy, convenient and constant method of making embossed printing for Braille character encoding
Character encoding
A character encoding system consists of a code that pairs each character from a given repertoire with something else, such as a sequence of natural numbers, octets or electrical pulses, in order to facilitate the transmission of data through telecommunication networks or storage of text in...

. Prior methods of making raised printing for the blind required a movable type printing press.
The basic design of the slate consists of two pieces of metal, plastic or wood fastened together with a hinge at one side.

The back of the slate is solid with slight depressions spaced in braille cells of six raised dots arranged in a grid of two dots horizontally by three dots vertically.
 
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