Ink jet printing head

摘要

One or more printing elements in tube form with a capillary nozzle at one end are mounted in aligned and mutually parallel relationship with a cavity in a support. The printing elements have piezoelectric sleeves thereon and are embedded in a filling of polymerised resin which fills the cavity. They are disposed in such a way that the nozzles project externally from the support while the other ends communicate with a common ink reservoir. The upper wall of the reservoir at each tube is arched with the highest region aligned with the corresponding tube in such a way that any bubbles in the ink can be easily expelled by way of the nozzles. A capillary filter separates the chamber of the reservoir from an ink feed conduit to prevent impurities or air bubbles from passing therethrough. In another embodiment, the reservoir is partitioned into a plurality of separate chambers to ensure that emptying of one tube does not affect operation of the adjacent tubes.