platen vs roller

platen and roller both are nouns.

Word	Noun	Adjective	Verb	Adverb
platen	Yes	No	No	No
roller	Yes	No	No	No

As nouns, roller is a hypernym of platen; that is, roller is a word with a broader meaning than platen:

platen (noun)	roller (noun)
the roller on a typewriter against which the keys strike	a grounder that rolls along the infield
the flat plate of a printing press that presses the paper against the type	Old World bird that tumbles or rolls in flight; related to kingfishers
work table of a machine tool	pigeon that executes backward somersaults in flight or on the ground
	a cylinder that revolves
	a mechanical device consisting of a cylindrical tube around which the hair is wound to curl it
	a small wheel without spokes (as on a roller skate)
	a long heavy sea wave as it advances towards the shore