Abstract: A liquid ejection head includes a liquid ejection head substrate having ejection elements that generate liquid ejecting energy, an ejection port formation member having ejection ports, and liquid chambers between the liquid ejection head substrate and the ejection port formation member to house liquid to be ejected through the ejection ports. The liquid ejection head substrate includes a substrate, an insulating film stacked on the substrate to insulate the ejection elements, communication ports in the substrate and the insulating film to communicate with the liquid chambers, and a liquid-resistant insulating film adherent to the ejection port formation member. The liquid-resistant insulating film covers the insulating film at its ejection port formation member side and includes a first portion partially contacting the ejection port formation member and a second portion covering the inner surfaces of the communication ports in the insulating film, the first and second portions being continuous.

Abstract: A technique capable of appropriately detecting a timing for replacement of a liquid ejection head is to be provided. A liquid ejection head including: a first electrode configured to protect an electrothermal conversion element that ejects a liquid from an ejection port and to be capable of eluting into the liquid by an electrochemical reaction with the liquid; and a second electrode installed so as to be electrically connectable to the first electrode via the liquid, wherein a voltage is applied to cause the second electrode to generate the electrochemical reaction with the first electrode, so that the first electrode is eluted into the liquid, wherein polarities can be reversed between the first electrode and the second electrode for applying the voltage, and wherein wiring resistance in a circuit including a plurality of second electrodes as a part of wiring can be measured.

Abstract: A liquid discharge apparatus includes a substrate, a discharge port configured to discharge ink, a flow path forming member formed on the substrate and in which a flow path configured to supply liquid to the discharge port is formed, a detection unit arranged between the substrate and the flow path forming member and formed of a material of which an electrical resistance value changes by contacting the liquid, and a measurement unit configured to measure the electrical resistance value of the detection unit.

Abstract: An object is to provide a liquid ejection apparatus and a method of controlling a liquid ejection apparatus capable of preventing bubbles generated by kogation removal from interfering with the kogation removal. To this end, in a long liquid ejection head with a liquid circulated therethough, a pressure chamber is pressurized and a voltage is applied to a heat applying portion and an electrode to perform kogation removing cleaning.

Abstract: An element substrate of multi-layer structure, comprising an electrothermal transducing element formed in a first layer, a protective film covering the electrothermal transducing element, an anti-cavitation film formed on the protective film, a first electrical wire formed in the same layer as the anti-cavitation film, arranged to be separated from the electrothermal transducing element, and electrically connected to at least one end of the electrothermal transducing element, a second electrical wire on an opposite side, in relation to the electrothermal transducing element, to the protective film, and formed in a second layer, and a first connection member that extends between the first and second layers, and that electrically connects the first and second electrical wires.

Abstract: An electrode pad portion of a liquid ejection head substrate includes a layer containing one of an iridium metal and an iridium alloy, and at least a portion of a cavitation resistant layer is provided in the same layer with the same material as the layer containing one of the iridium metal and the iridium alloy.

Abstract: An object is to provide a liquid ejection apparatus and a method of controlling a liquid ejection apparatus capable of preventing bubbles generated by kogation removal from interfering with the kogation removal. To this end, in a long liquid ejection head with a liquid circulated therethough, a pressure chamber is pressurized and a voltage is applied to a heat applying portion and an electrode to perform kogation removing cleaning.

Abstract: A liquid ejection head includes a liquid ejection head substrate having ejection elements that generate liquid ejecting energy, an ejection port formation member having ejection ports, and liquid chambers between the liquid ejection head substrate and the ejection port formation member to house liquid to be ejected through the ejection ports. The liquid ejection head substrate includes a substrate, an insulating film stacked on the substrate to insulate the ejection elements, communication ports in the substrate and the insulating film to communicate with the liquid chambers, and a liquid-resistant insulating film adherent to the ejection port formation member. The liquid-resistant insulating film covers the insulating film at its ejection port formation member side and includes a first portion partially contacting the ejection port formation member and a second portion covering the inner surfaces of the communication ports in the insulating film, the first and second portions being continuous.

Abstract: An element substrate of multi-layer structure, comprising an electrothermal transducing element formed in a first layer, a protective film covering the electrothermal transducing element, an anti-cavitation film formed on the protective film, a first electrical wire formed in the same layer as the anti-cavitation film, arranged to be separated from the electrothermal transducing element, and electrically connected to at least one end of the electrothermal transducing element, a second electrical wire on an opposite side, in relation to the electrothermal transducing element, to the protective film, and formed in a second layer, and a first connection member that extends between the first and second layers, and that electrically connects the first and second electrical wires.

Abstract: A liquid discharge head includes a flow passage forming member, an element substrate including a liquid discharge element and a surface on which a conductive member made from a metallic material is disposed, and an intermediate layer made from a resin material and configured to join the flow passage forming member and the surface of the element substrate to each other. The intermediate layer is disposed in a state, separated from the conductive member, where the conductive member is exposed from the intermediate layer. The conductive member is covered with the flow passage forming member.

Abstract: A method of cleaning a liquid discharge head includes first eluting a first electrode and second eluting a second electrode. In the cleaning method, the first eluting and the second eluting are executed such that a ratio between a first electric power amount used in the first eluting and a second electric power amount used in the second eluting is a ratio based on a ratio between an area of a first face of the first electrode and an area of a second face of the second electrode.

Abstract: In a layer including print elements and a layer below the layer including the print elements in a lamination direction of a print element substrate, the print elements and drive circuits are arranged point-symmetrically about the center of the substrate viewed from a side where discharge ports that allow the liquid to be discharged are open, and in an upper layer over the layer including the print elements in the lamination direction, functional elements are arranged in a direction of liquid flow in which the liquid flows from supply ports to collection ports while passing above the print elements.

Abstract: A liquid ejection apparatus, an ejection control method, and a liquid ejection head are capable of suppressing shortening of the life of the liquid ejection head and maintaining stable ejection operation. For this purpose, voltage is applied to upper electrodes and counter electrodes so as to make the voltage at the upper electrodes lower than the voltage at the counter electrodes before heat generating resistive elements are driven, and voltage is applied to the upper electrodes and the counter electrodes so as to make the voltage at the upper electrodes higher than the voltage at the counter electrodes at the same time as or after the start of driving of the heat generating resistive elements.

Abstract: A liquid ejection head substrate including a base including a surface having a first and second heat generation elements, a conductive first covering portion, a conductive second covering portion, an insulating layer disposed between the first heat generation element and the first covering portion, and between the second heat generation element and the second covering portion, a fuse portion, first wiring electrically connected to the first covering portion through the fuse portion, the first wiring electrically connecting the first covering portion to the second covering portion, a terminal electrically connected to the first covering portion and the second covering portion through the first wiring, second wiring, and electric connection portions provided between the fuse portion and the terminal in a current path passing through the first wiring, the electric connection portions parallelly connecting the first and second wiring to each other.

Abstract: A liquid discharge apparatus includes a plurality of anti-cavitation layers formed to cover heat generating elements at positions where the anti-cavitation layers contact the liquid, a monitoring unit that detects a current flowing through the anti-cavitation layers, and a plurality of switching units that switch whether to apply, to the heat generating elements, a voltage for driving the heat generating elements. If the monitoring unit detects that a current greater than a predetermined value has flowed through one of the anti-cavitation layers while the voltage is applied to the heat generating elements, a control unit sequentially switches the plurality of switching units, and specifies the heat generating element corresponding to the anti-cavitation layer through which the current has flowed, among the heat generating elements.

Abstract: The liquid discharge head substrate includes a first covering portion that covers the first heat generation element and that has conductivity, a second covering portion that covers the second heat generation element and that has conductivity, an insulative layer disposed between the first heat generation element and the first covering portion and between the second heat generation element and the second covering portion, a fuse portion provided on the substrate on a side on which the first covering portion is provided, common wiring for electrically coupling the first covering portion and the second covering portion, the common wiring coupled with the first covering portion via the fuse portion, and a cover layer including at least silicon and carbon and covering the fuse portion.

Abstract: A method of cleaning a liquid discharge head includes first eluting a first electrode and second eluting a second electrode. In the cleaning method, the first eluting and the second eluting are executed such that a ratio between a first electric power amount used in the first eluting and a second electric power amount used in the second eluting is a ratio based on a ratio between an area of a first face of the first electrode and an area of a second face of the second electrode.

Abstract: An electrode pad portion of a liquid ejection head substrate includes a layer containing one of an iridium metal and an iridium alloy, and at least a portion of a cavitation resistant layer is provided in the same layer with the same material as the layer containing one of the iridium metal and the iridium alloy.

Abstract: A liquid discharge head includes a flow passage forming member, an element substrate including a liquid discharge element and a surface on which a conductive member made from a metallic material is disposed, and an intermediate layer made from a resin material and configured to join the flow passage forming member and the surface of the element substrate to each other. The intermediate layer is disposed in a state, separated from the conductive member, where the conductive member is exposed from the intermediate layer. The conductive member is covered with the flow passage forming member.

Abstract: A liquid-discharge-head substrate includes a first covering portion covering a first heating resistance element and having electrical conductivity, a second covering portion covering a second heating resistance element and having electrical conductivity, a fuse, and a common wiring line for electrically connecting the first and second covering portions. The common wiring line is electrically connected with the first covering portion via the fuse. The common wiring line and the fuse each have a multilayer structure including a stack of a plurality of conductive layers including a first conductive layer and a second conductive layer that is less oxidizable than the first conductive layer.