Abstract: A liquid ejection head includes a liquid chamber having an element that generates thermal energy, a discharge port for liquid, a nozzle that communicates between the discharge port and the liquid chamber, and a liquid supply path and a liquid collection path in communication with the liquid chamber on opposite sides. The thermal energy forms a bubble in the liquid chamber, and the formed bubble enters the nozzle to eject liquid under pressure of the bubble. In a state where at least a portion of the bubble in the nozzle has a velocity component toward a surface of the liquid chamber that has the element and before liquid to be ejected comes in contact with the surface of the liquid chamber by being drawn into the liquid chamber by contraction of the bubble, the bubble communicates with an atmosphere and the liquid is ejected through the discharge port.

Abstract: An aspect of the present disclosure is a liquid ejection apparatus including: a liquid ejection head including a conversion element that generates energy required to eject liquid, a first protection layer that blocks contact between the conversion element and the liquid, a second protection layer that partially covers the first protection layer and functions as a first electrode, a second electrode that is electrically connected to the first electrode through the liquid, and an ejection port that ejects the liquid, and a control unit configured to control a potential difference between the first electrode and the second electrode in printing to a predetermined value by changing at least one of potentials of the first electrode and the second electrode. The control unit sets the potential difference based on at least one of a condition and a configuration of the liquid ejection head.

Abstract: A liquid ejection head includes an element substrate provided with an ejection port row in which ejection ports are arrayed. The port includes a protruding portion protruding toward a center of the ejection port, an energy generation element configured to generate energy to eject liquid, and a pressure chamber including the energy generation element thereinside. The head has a liquid supply path for supplying liquid to the pressure chamber, and a liquid collecting path for collecting liquid from the pressure chamber. A direction in which the protruding portion protrudes is substantially parallel to a flow direction of liquid in the pressure chamber flowing from the liquid supply path to the liquid collecting path via the pressure chamber. The flow direction is same direction in the pressure chambers, and is same direction as a relative moving direction of a medium that receives liquid ejected from the liquid ejection head.

Abstract: An aspect of the present invention is a liquid ejection apparatus including: a liquid ejection head including a heating element, a first protection layer, a second protection layer that functions as a first electrode, a second electrode that is electrically connected to the first electrode, and an ejection port; and a control unit configured to perform control of setting a potential difference between potentials of the first and second electrodes to a predetermined value by changing at least one of the potentials of the first electrode and the second electrode, in which the control unit sets the potential difference to a first value in a case where printing is performed, and the control unit sets the potential difference to a second value different from the first value and feeds power to at least one of a plurality of the heating elements in a case where printing is not performed.

Abstract: A liquid ejection head includes ejection nozzles, pressure compartments, a supply port, and first pillar structures. The pressure compartments which each communicate with a corresponding ejection nozzle of the ejection nozzles and are each combined with an energy generating element configured to generates ejection energy for ejecting liquid. The supply port supplies the liquid to the pressure compartments. The first pillar structures are arranged between the supply port and the pressure compartments. The pressure compartments is each defined by a flow path walls arranged in line and parallel to each other. A liquid flow path is formed and configured to allow the liquid to flow through the liquid flow path from the at least one supply port via the first pillar structures into the pressure compartments. A longest clearance between the first pillar structures is smaller than a shortest clearance between the flow path walls and the first pillar structures.

Abstract: An aspect of the present invention is a liquid ejection apparatus including: a liquid ejection head including a heating element, a first protection layer, a second protection layer that functions as a first electrode, a second electrode that is electrically connected to the first electrode, and an ejection port; and a control unit configured to perform control of setting a potential difference between potentials of the first and second electrodes to a predetermined value by changing at least one of the potentials of the first electrode and the second electrode, in which the control unit sets the potential difference to a first value in a case where printing is performed, and the control unit sets the potential difference to a second value different from the first value and feeds power to at least one of a plurality of the heating elements in a case where printing is not performed.

Abstract: An aspect of the present disclosure is a liquid ejection apparatus including: a liquid ejection head including a conversion element that generates energy required to eject liquid, a first protection layer that blocks contact between the conversion element and the liquid, a second protection layer that partially covers the first protection layer and functions as a first electrode, a second electrode that is electrically connected to the first electrode through the liquid, and an ejection port that ejects the liquid, and a control unit configured to control a potential difference between the first electrode and the second electrode in printing to a predetermined value by changing at least one of potentials of the first electrode and the second electrode. The control unit sets the potential difference based on at least one of a condition and a configuration of the liquid ejection head.