Abstract: A method for cleaning a liquid ejection head which includes applying a voltage to a coating layer of the liquid ejection head to cause the coating layer to be eluted in a liquid so that kogation deposited on a coating layer is removed. When removing kogation deposited on the coating layer, temperatures of the liquids in the liquid chambers are selectively changed among a plurality of liquid chambers.

Abstract: Cleaning under appropriate cleaning conditions is performed by disposing an electrode pair for measuring conductivity in the same liquid chamber as that of a material layer (i.e., an upper electrode) of a surface of a thermal action portion to be eluted, and measuring conductivity of a liquid using the electrode pair before kogation is removed.

Abstract: A method for cleaning a liquid ejection head, including a flow path forming member forming a liquid flow path, a heat generating resistive element, and a coating layer covering the heat generating resistive element and in contact with the liquid, in which the heat generating resistive element is made to generate heat and the liquid is made to be ejected from ejection ports, the method including: applying a voltage to the coating layer to produce an electrochemical reaction between the coating layer and the liquid, and causing the coating layer to be eluted into the liquid, thereby removing kogation deposited on the coating layer; and causing the heat generating resistive element to generate heat and causing the liquid to be ejected from the ejection ports while a voltage is applied to the coating layer continuously or intermittently, thereby eliminating air bubbles generated due to the electrochemical reaction.

Abstract: A print head includes upper protective members located at positions corresponding to heat generating resistor elements to protect the heat generating resistor elements, and further, a part of the protective member can be eluted into ink when a current flows inside in a state in which the ink is stored in the pressure chambers. The print head includes a drive element and a logic circuit capable of allowing a current to independently flow in each of the upper protective layers so as to elute a part of the upper protective layer, in which the current flows, into the ink.

Abstract: A liquid discharge device includes a liquid discharge head including a discharge port surface on which discharge ports for discharging liquid are formed, an electrothermal conversion element configured to generate energy for discharging liquid from the discharge ports, and a protection film configured to cover at least the electrothermal conversion element, and a cap configured to cover the discharge port surface, wherein the cap is arranged along the discharge port surface at a position opposite to the protection film via the discharge ports in a state where the cap covers the discharge port surface, and wherein the cap includes an electrode configured to be used to apply voltage between the protection film and the electrode.

Abstract: In a liquid ejection head for ejecting liquid by using thermal energy, reduction of film thickness caused by elution of a protective layer when kogation on the protective layer is removed is uniformized and decrease in liquid ejection performance is suppressed. More specifically, a counter electrode is provided around a portion on which an ejection port of a flow path forming member is formed.

Abstract: A substrate for a liquid discharge head includes an upper protection film that covers at least a region corresponding to each of thermal energy generation elements. The upper protection film and at least one of the upper protection films adjacent to the upper protection film within a liquid chamber are respectively connected to different external electrodes, and a voltage can be applied therebetween via the different external electrodes.

Abstract: A print head includes upper protective members located at positions corresponding to heat generating resistor elements to protect the heat generating resistor elements, and further, a part of the protective member being eluted to ink when a current flows inside in a state in which the ink is reserved in the pressure chambers. The print head includes a drive element and a logic circuit capable of allowing a current to independently flow in each of the upper protective layers so as to elute a part of the upper protective layer, in which the current flows, to the ink.

Abstract: A liquid ejection head substrate includes a substrate, an element disposed on the substrate that generates thermal energy used for ejecting liquid, and a protective layer disposed at least at a position corresponding to the element. The protective layer contains iridium and has a density in the range of 21.0 g/cm3 to 22.7 g/cm3.

Abstract: A reproduction method of a liquid ejecting head including: a process of filling the flow path with an electrolyte solution containing metal, and filling a space between an electrode capable of applying a voltage to between itself and the upper protective film and the upper protective film with the electrolyte solution; and a process of applying a voltage to between the upper protective film and the electrode to make the metal contained in the electrolyte solution deposit on the surface of the upper protective film.

Abstract: A substrate for a liquid discharge head includes an upper protection film that covers at least a region corresponding to each of thermal energy generation elements. The upper protection film and at least one of the upper protection films adjacent to the upper protection film within a liquid chamber are respectively connected to different external electrodes, and a voltage can be applied therebetween via the different external electrodes.

Abstract: A liquid discharge device includes a liquid discharge head including a discharge port surface on which discharge ports for discharging liquid are formed, an electrothermal conversion element configured to generate energy for discharging liquid from the discharge ports, and a protection film configured to cover at least the electrothermal conversion element, and a cap configured to cover the discharge port surface, wherein the cap is arranged along the discharge port surface at a position opposite to the protection film via the discharge ports in a state where the cap covers the discharge port surface, and wherein the cap includes an electrode configured to be used to apply voltage between the protection film and the electrode.