Inkjet recording apparatus and method of controlling the same

An inkjet recording apparatus comprises:

• a recording head which discharges an ink to perform a recording operation;
• an ink tank which stores the ink to be supplied to the recording head;
• a supply channel through which the ink is supplied from the ink tank to the recording head;
• a supply pump provided in the supply channel;
• a collection channel through which the ink is collected from the recording head to the ink tank;
• a collection pump provided in the collection channel;
• and
• a buffer chamber provided in the recording head or the collection channel and having a volume which is changed according to a pressure,
• wherein the recording head includes a discharge opening through which the ink is discharged, a common channel connected with the supply channel and the collection channel, and a pressure control unit which changes, according to a pressure, between an opened state in which the ink is passed through the common channel and a closed state in which the ink is not passed through the common channel,
• wherein the inkjet recording apparatus forms a circulation state in which the ink is circulated between the recording head and the ink tank by driving the supply pump and the collection pump, whereas the inkjet recording apparatus stops the driving of the supply pump and the collection pump and forms a pause state in which the ink is not circulated, and
• wherein before the inkjet recording apparatus is to be changed from the circulation state to the pause state, the inkjet recording apparatus stops the driving of the supply pump and the collection pump and forms a waiting state for a predetermined time in which the negative pressure in the collection channel is larger than that in the pause state by the buffer chamber.