The platen is the cylinder in an impact printer (such as a dot-matrix or |daisy wheel printer|) around which the paper wraps. As the cylinder turns, the paper is brought past the print head. The print head strikes the ribbon against the paper, using the platen as a backstop. The platen usually is covered by a semi-soft rubbery material to minimize risk of damage to the print head mechanism or the paper. The platen may be advanced manually by turning a platen roller. This is a knob on the end of the cylinder.
