US Patent 7344231 Inkjet digital printing device and ink reservoir

The present invention relates to a digital device for printing on “open” or “closed” surface substrates by demand bubble-jet comprising at least one built-in ink reservoir (13) with a system of anti-splash partitions, at least one printhead and one buffer reservoir, the whole located in a print module (1) which moves in relation to the substrate (5). The device comprises a means for creating, during operation of the module, on the one hand, a vacuum in the built-in reservoir, with a method of active regulation of this vacuum by adjustment of the ink level detected by a sensor attached to the built-in reservoir and, on the other hand, the air pressure in the built-in reservoir required for printhead cleaning phases.