Ink circulation device and inkjet recording device

An inkjet recording device, comprising:

• an ink circulation device;
• an inkjet head comprising nozzles;
• and
• a conveyance section configured to convey an image receiving medium to a print position of the inkjet head, wherein
• the ink circulation device comprising:
• an ink supply for supplying ink to nozzles of an inkjet head;
• an ink return section configured to return ink which is not ejected by the nozzles;
• an ink circulation pump arranged between the ink supply and the ink return section;
• a filter positioned to partition an upstream side ink flow path arranged between an ejection section of the ink circulation pump and the ink supply into a first flow path communicating with the ejection section of the ink circulation pump and a second flow path communicating with the ink supply, and configured to catch bubbles in the ink in the first flow path;
• and
• a bypass section arranged at the upper part of a vertical direction with respect to the filter, and configured to directly communicate the first flow path with a downstream side ink flow path arranged between the ink return section and a suction section of the ink circulation pump.

An ink circulation method, comprising:

• supplying ink to nozzles of an inkjet head;
• returning ink which is not ejected by the nozzles;
• pumping ink with an ink circulation pump arranged between an ink supply and an ink return section;
• filtering bubbles from the ink flowing in a first flow path communicating with an ejection section of the ink circulation pump;
• and
• flowing ink through a bypass section arranged at the upper part of a vertical direction with respect to a filter.