Measuring apparatus for the ink-level in ink-jet printing unit.

摘要

In an ink-jet printing unit comprising a printing head (24) mounted on the reservoir, a measuring circuit comprising a pair of electrodes (40,41) which substantially enclose the volume of ink within the reservoir, allows hysteresis-free linear mode measurement of variations in the ink volume within the reservoir and the signalling of at least one of the ends of the variation interval to indicate the most suitable moment for recharging ink in the reservoir by means of a cartridge (20) inserted into the reservoir.