Method Of Cleaning Liquid Ejection Head And Liquid Ejection Apparatus

A liquid ejection apparatus comprising:

• a liquid ejection head including a nozzle plate provided with a plurality of nozzles each configured to eject a liquid, a pressure chamber communicating with the nozzle, a diaphragm constituting a part of the pressure chamber, and a first piezoelectric element stacked on the diaphragm;
• a cap disposed to face an ejection surface of the nozzle plate provided with a nozzle opening;
• a second piezoelectric element provided to the cap and configured to transmit an ultrasonic wave to the liquid in the cap;
• a pump configured to suck the liquid in the cap;
• and
• a controller configured to control drive of the liquid ejection apparatus, wherein
• the controller is configured to execute, in this order,
• filling an inside of the cap with the liquid by driving the first piezoelectric element with a first drive signal to eject the liquid from the nozzle,
• introducing air into the nozzle by driving the first piezoelectric element with a second drive signal different from the first drive signal,
• bringing the ejection surface into contact with the liquid in the cap,
• transmitting the ultrasonic wave to the liquid in the cap by driving the second piezoelectric element with a third drive signal, and
• sucking the liquid in the cap by driving the suction pump.