Patent ID: 8205973
Filing Date: 2012-06-26
Classification: B41J

Abstract:
1. An ink jet recording apparatus comprising: an ink jet head having a pressure chamber facing a nozzle, and an upstream port and a downstream port connected to the pressure chamber; a main tank connected to the ink jet head via the upstream port and capable of storing ink therein; and a sub-tank connected to the ink jet head via the downstream port and capable of storing ink therein; wherein at least when printing by ejecting ink from the nozzle, the relation between ph, r, R and Q is held to satisfy ph−{QR×(1/(1+r))}=Pn (Pn being a constant representing a proper pressure in the nozzle), where ph represents a potential pressure in the main tank as viewed from a surface of an orifice plate where the nozzle of the ink jet head is formed, R represents a total flow path resistance from the main tank to the sub-tank via the ink jet head, a ratio of a flow path resistance from the main tank to the nozzle and a flow path resistance from the nozzle to the sub-tank is expressed by 1:r, and Q represents a flow rate of ink that circulates in a circulation path formed by connecting the ink jet head, the main tank and the sub-tank.