Patent ID: 7540580

Claim:
A liquid ejection apparatus, comprising: an ejection head which has a plurality of ejection elements, each of the ejection elements from amongst the plurality of ejection elements including an ejection aperture through which a droplet of liquid is ejected onto an ejection receiving medium, a pressure chamber which is connected to the ejection aperture and accommodates the liquid to be ejected from the ejection aperture, and a pressurizing device which applies an ejection pressure to the liquid accommodated in the pressure chamber; a meniscus vibration drive signal application device which applies to the pressurizing device a meniscus vibration drive signal for suppressing increase in viscosity of the liquid in vicinity of the ejection aperture by causing a meniscus surface of the liquid to vibrate and to eject no droplet from the ejection aperture; a pressure determination device which determines pressure in the pressure chamber when the meniscus surface is vibrated by the meniscus vibration drive signal; and an ejection abnormality judgment device which judges an abnormal state of the ejection element from pressure information of the pressure chamber based on pressure determination information obtained by the pressure determination device wherein the pressure determination device is configured to determine pressure in the pressure chamber when the ejection element is in an idle state during an ejection operation where other ejection elements are ejecting ink during said ejection operation.