Patent ID: 8764170

Claim:
An ink-jet head used to form an image on a recording medium by ejecting an ink-jet ink from a nozzle, the ink-jet head comprising: a head tip to eject an ink containing a cationically polymerizable composition containing a cationically polymerizable compound and a cationic polymerization initiator or a radically polymerizable composition containing a radically polymerizable monomer and a photoradical polymerization initiator, a manifold to supply the ink to the head tip, a connection portion provided between the manifold and the head tip and a filter to filter the ink-jet ink, the ink-head tip having an ink supply opening and an ink ejection orifice from which the ink is ejected, wherein the connection portion connects to the ink supply opening of the ink-head tip so that the ink is supplied from the manifold through the connection portion to the ink-head tip, wherein a surface of a metal constituting a liquid contact member in contact with the ink-jet ink inside the ink-jet head is at least partially subjected to a passive treatment or an insulating film treatment, the metal being stainless steel, and wherein the liquid contact member is at least one selected from the manifold, the connection portion and the filter.