Design
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. In the shape of an inverted braille dot of approximately 1.5 mm (0.059 in) diameter; .75 mm (0.030 in) depth or height; the horizontal and vertical spacing between dot centers within a braille cell is approximately 2.5 mm (0.098 in) cell to cell (dot 1 center to dot 1 center horizontally) 6.5 mm (0.26 in).
The front of the slate has a corresponding rectangular cells with indentations in the side of the cell, over the depressions in the back so the blind user can properly position the stylus and press to form a dot.
There are pins or posts in the back of the slate positioned in non-cell areas to hold the paper in place and keep the top properly positioned over the back. The pins align with matching depressions on the opposite side of the slate. A slate as designed for a normal 8.5 inch piece of paper has 28 cells. It can have any number of rows, usually at least four.
The stylus is a short blunted awl with a handle to comfortably fit the hand of the user.
Read more about this topic: Slate And Stylus
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