Printing apparatus having an integral speed pickup wheel

A printing apparatus comprising a first shaft, a printing head integral in rotation with the first shaft, a counter-roller defining with the printing head a gap for a film, a second shaft parallel to the first shaft, an inking roller fixed for rotation with the second shaft, means for rotating the second shaft when the first shaft turns, an electric motor having an output shaft and means for driving the first shaft, a third shaft parallel to the first shaft and located in a plane defined by the first shaft and the second shaft, a speed pickup wheel mounted freely on the third shaft and in contact at its periphery with the film, a fourth shaft parallel to the first shaft, a tachometer mounted on the fourth shaft, and a coupling between the speed pickup wheel and the tachometer, whereby the tachometer detects the speed of rotation of the speed pickup wheel.