Abstract: The printer device is fashioned as an independent structural unit and is arranged such that the printer head is situated in front of a cooperating platen that is seated such next to the deflection roller that does not cover the full width of the document in the document processing means that its apex line facing toward the printer head proceeds in alignment with a corresponding apex line of the deflection roller. The structural unit is held in guide elements and is removable from the printing position tangentially relative to the apex line of the cooperating platen along the guide elements. A printer head operating based on the thermo transfer principle and having a thermo-inking ribbon transported synchronously with the document preferably serves as the printer device.

Abstract: A symmetrically constructed inking ribbon cassette is provided that is substantially rectangular in shape and which has two openings symmetrically arranged at the shorter sides of the cassette for receiving capstan drive shaft and a light barrier. The cassette housing is formed of two halves which are held together with catch noses at a joining plane of the housing halves and a viewing slot is provided in each slot adjacent to one of the ribbon winding hubs which are carried in the housing.