Definition of platens:
(n) :
(printing) The part of a printing press which presses the paper against the type and by which the impression is made.
(n) :
The part of a typewriter or printer on which the paper rests to receive an impression.
(n) :
The flat glass surface of a scanner or photocopier on which operators place items to be scanned.
(n) :
The movable table of a planer or other machine tool, on which the work is fastened, and presented to the action of the tool.