Air bubble collector for printing head ink supply - has filter spaced by capillary distance from adjacent surface

摘要

In a matrix printer the ink supply to the printing head is passed through a capillary filter (13). Latter is a flat disc mounted between axially facing surfaces (19, 18) of a housing, the surfaces having an inlet and an outlet port (16, 10) respectively. At least the surface having the outlet port is spaced from the filter by no more than a capillary distance. The arrangement favours the removal of air bubbles from the ink in a chamber (12) upstream of the inlet port.