E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Platen,
among printers, is the power or weight which presses on the tympan (q.v.), to cause the impression of the letters to be given off and transferred to the sheet. (French, plat, flat.)
1
In type-writing machines, the platen is the feeding roller on which the paper rests to receive the proper impressions.