Patent ID: 8500256

Claim:
An inkjet device including an inkjet head provided with a driving electrode in a channel for circulating ink and configured to apply an electric field to the driving electrode to thereby discharge the ink from an ink discharge port, the device comprising: an ink circulating device configured to communicate with the inkjet head to form an ink circulating system; an arithmetic unit configured to calculate, on the basis of pressure detected from the ink circulating system, pressure in a section of the ink discharge port according to an arithmetic expression set in advance; a pressure determining unit configured to determine, with proper nozzle pressure in the ink discharge port not discharging ink set as a reference value, whether a value calculated by the arithmetic unit is positive pressure or negative pressure with respect to the reference value, and to be able to change the reference value to a negative pressure side; and a negative pressure regulator configured to communicate with the ink circulating system and perform, if the pressure determining unit determines that the value is the positive pressure, an ink reducing operation in the ink circulating system and increase a negative pressure value on the ink discharge port.