When operating an ink jet print head with a large number of openings, which an improved cleaning - and has output performance

摘要

An improved ink jet print head includes tapered manifolds (222) , ports (234), and inlet channels (214) all leading elevationally upward to sweep bubbles from the head, aided by their buoyancy. The ports opening to the inlet channels are distributed at staggered locations throughout the manifolds with at least some of the ports located adjacent to the elevationally highest edge of each manifold. This aspect of the invention reduces bubble entrapment and improves jetting performance by reducing acoustic cross-talk among ink pressure chambers (204) of the head. Moreover, tapering the ink supply manifolds and other features causes more uniform ink flow rates and reduces flow rate stagnation regions within the head. Purging cycles therefore require smaller volumes of ink than with prior designs.