Recording apparatus having a tapered roller platen for exerting a uniform pressing force against recording elements

Claim 1

A recording apparatus comprising: a non-rigid recording head over which a sheet-like recording element means is passed, said recording head having opposite ends adjacent opposite side edges of the recording element means respectively; a roller-form platen in pressing engagement with said recording head, the recording element means passing between said roller-form platen and said recording head, said roller-form platen having an axis of rotation extending perpendicular to the direction in which the recording element means passes over the recording head, said roller-form platen having an axial length as measured along said axis of rotation that is at least as long as the recording element means is wide, and said roller-form platen having opposite ends adjacent the opposite side edges of the recording element means respectively; biasing means connected to said recording head and/or said roller-form platen for pressing said recording head and said roller-form platen against each other by exerting respective biasing forces at said opposite ends of said recording head thereby slightly deforming said non-rigid recording head; and said roller-form platen having an outer diameter that is largest at a median portion thereof that is between said opposite ends of the roller-form platen, said outer diameter of said roller-form platen at said median portion being larger than each of the outer diameters of the roller-form platen at said opposite ends thereof for pressing against and maintaining a uniform pressing force across the entire width of the sheet when the recording head deforms slightly when subjected to the respective biasing forces.