Powdered magnetic ink printing devices

Abstract

The invention relates to a printing device comprising: a travelling surface, for example the surface of a drum, driven in rotation by the action of first motor means, said travelling surface supporting a thin magnetic layer; a scanning support driven with a step-by-step reciprocal movement, perpendicular to the movement of the travelling surface of said drum, by the action of second motor means, said scanning support supporting at least one group of integrated magnetic induction heads, this group of heads being connected to sequential control means; powdered magnetic ink supply means; ordinary paper supply means; said scanning support having an annular shape surrounding the travelling surface of the drum over a considerable part at least of its circumferential extent; said scanning support comprising two lateral parts surrounding a central part; said lateral parts being arranged to create a seal between themselves and said travelling surface of said drum; said central part supporting one, or preferably more, groups of integrated magnetic induction heads; a compressed gas supply device connected to said central part; said powdered magnetic ink supply means being connected to the outside of said scanning support.

Dependencies are inferred from the claim text.