Ink jet printer having bubble purge mechanism

摘要

An ink jet printer having bubble purging arrangement for discharging bubbles mixed in the ink out of a print head. The print head has a main tank for storing ink, a sub tank for collecting and storing ink, and a manifold fluidly connecting the main tank and the sub tank. The manifold is in fluid communication with the nozzles for supplying ink from the main tank to the nozzles. Three kind of purging modes are provided in accordance with purging position of the print head. Pressurizing pump is selectively connected to the main tank or sub tank or both main tank and the sub tank through a valve arrangement. If the pump is fluidly connected to the main tank only, the ink in the main flows into the sub tank. If the pump is fluidly connected to the sub tank only, the ink in the sub tank flows back into the main tank. By alternating the fluid connection, bubbles mixed in the ink is gradually concentrated at an upper portion of the manifold. If the pump is fluidly connected to both the main tank and the sub tank, the concentrated bubbles is positively discharged outside through the nozzles.