Abstract: The invention concerns a device for unlocking a compartment of an opening mechanism, comprising a frame, the compartment being designed to receive a paper roll, and being closed with a cover (10). The invention is characterised in that a lever (22) is mounted rotating on the cover (10) and comprises a manoeuvring part (24), the lever (22) comprising stop elements (30) capable of co-operating with the sides of the frame to cause the cover (10) to rotate relative to the frame when the lever (22) is rotated relative to the cover (10). The invention is applicable to opening mechanisms for thermal printing machines.

Abstract: A thermal printing device is capable of being closed by clipping. The device according to the invention includes a printhead 2, a roller 4 integral with a gear assembly, whereon rests the printhead 2 when the device is in the printing position and two orifices 6, 7 on each lateral side of the frame, characterized in that the portion of the orifices 6 and 7 opposite the printhead is so configured as to present a position of unstable equilibrium of the roller when its axis is moving in said orifices 6, 7 when it is subjected to the pressure of the printhead. The invention is applicable to compact devices.

Abstract: The invention concerns a printing mechanism designed for producing an ultra-compact mechanism. The thermal printing mechanism comprises a frame, a motor and a gear assembly driving a roller (7), a thermal printing head (8), a member pressing (9) the head (8) on the roller (7), characterized in that it comprises a member providing at least vertical rigidity (1) to two separate sides of the frame and at least rotational resistance along an axis substantially perpendicular to a third side of the frame, or, at least rotational resistance to two sides of the frame. The invention is useful for printing mechanisms of electronic payment terminals.