PRINTING APPARATUS

PURPOSE:To reduce printing paper consumption and to facilitate reading out by alternatively printing onto both front and back surfaces by equipping printing types and their mirrored characters in parallel for a printing mean, and further equipping an ink ribbon feeding mechanism on the back side of the printing paper. CONSTITUTION:Ordinary printing types and the mirrored characters thereof are alternately lined up on the surface of a printing type drum 17. Printing masks 15-1, 15-2 are formed into a thin film with such as Mylar, in which holes 16-1, 16-2 through which a printing hammer 5 passes are respectively made in such manner that both holes are not overlapped each other during printing operation. For example, each frame in which the printing mask is extendedly equipped are altenatively oscillated like a seesaw so as to be caused to correspond the head of the hammer 5 and the hole 16-1 at printing onto the front surface of paper 2, as well as the above head of hammer and the hole 16-2 at printing onto the back surface.