Abstract: A liquid ejecting head maintains stable ejecting operations without causing kogation. To achieve such operations, the liquid ejecting head includes, in its liquid chamber, a first electrode placed so as to cover a heating resistor, a second electrode placed at a position different from that of the first electrode, and a third electrode. In a case where the heating resistor is driven, a voltage is applied between the first electrode and the second electrode so that the first electrode has the same polarity as that of a predetermined liquid component, and the second electrode has the opposite polarity. In a case where the heating resistor is not driven, a voltage is applied between the second electrode and the third electrode so that the second electrode has the same polarity as that of the predetermined component, and the third electrode has the opposite polarity.

Abstract: A control method of a liquid ejection head, in which the liquid ejection head having first and second heat generating resistors that generate thermal energy for ejecting liquid, includes first covering portion covers the first heat generating resistor. A second covering portion is electrically connected to the first covering portion and covering the second heat generating resistor. An insulating layer is provided between the first heat generating resistor and the first covering portion and between the second heat generating resistor and the second covering portion. Surface potentials are set of the first and second covering portions to be equal to or less than a ground potential in a state where drive voltage is not applied to the first and second heat generating resistors, is accomplished in accordance with application of drive voltage to at least either the first heat generating resistor or the second heat generating resistor.

Abstract: The liquid ejection head includes a wall member having formed therein a void for communicating between a first liquid chamber and a second liquid chamber; a first energy generation element to eject the liquid in the first liquid chamber; a second energy generation element to eject the liquid in the second liquid chamber; a first electrode arranged in a vicinity of the first energy generation element in the first liquid chamber; a second electrode for forming, between the first electrode and the second electrode, an electric field in liquid inside the first liquid chamber; and a supply port which supplies liquid to the first energy generation element. The wall member includes a channel wall defining a channel through which the second liquid chamber, the void, and the supply port communicate, and the second electrode is arranged between the second liquid chamber and the supply port in the channel.

Abstract: A control method of a liquid ejection head, in which the liquid ejection head having first and second heat generating resistors that generate thermal energy for ejecting liquid, includes first covering portion covers the first heat generating resistor. A second covering portion is electrically connected to the first covering portion and covering the second heat generating resistor. An insulating layer is provided between the first heat generating resistor and the first covering portion and between the second heat generating resistor and the second covering portion. Surface potentials are set of the first and second covering portions to be equal to or less than a ground potential in a state where drive voltage is not applied to the first and second heat generating resistors, is accomplished in accordance with application of drive voltage to at least either the first heat generating resistor or the second heat generating resistor.

Abstract: A liquid ejecting head maintains stable ejecting operations without causing kogation. To achieve such operations, the liquid ejecting head includes, in its liquid chamber, a first electrode placed so as to cover a heating resistor, a second electrode placed at a position different from that of the first electrode, and a third electrode. In a case where the heating resistor is driven, a voltage is applied between the first electrode and the second electrode so that the first electrode has the same polarity as that of a predetermined liquid component, and the second electrode has the opposite polarity. In a case where the heating resistor is not driven, a voltage is applied between the second electrode and the third electrode so that the second electrode has the same polarity as that of the predetermined component, and the third electrode has the opposite polarity.

Abstract: An electric potential difference between both ends of a first fuse portion is increased to more than the electric potential difference that is generated by an electric potential applied to drive print elements in a state where a first print element and a first covering portion are electrically connected to each other.

Abstract: The liquid ejection head includes: a wall member having formed therein a void for communicating between a first liquid chamber and a second liquid chamber; a first energy generation element to eject the liquid in the first liquid chamber; a second energy generation element to eject the liquid in the second liquid chamber; a first electrode is arranged in a vicinity of the first energy generation element in the first liquid chamber; a second electrode for forming, between the first electrode and the second electrode, an electric field in liquid inside the first liquid chamber; and a supply port which supplies liquid to the first energy generation element, wherein the wall member includes a channel wall in which the second liquid chamber, the void, and the supply port communicate, and the second electrode is arranged between the second liquid chamber and the supply port in the channel.

Abstract: A method of cleaning a liquid discharge head, which includes a heat generating resistor that generates thermal energy for discharging a liquid and a covering portion covering the heat generating resistor, includes alternately performing a first voltage application process and a second voltage application process multiple times, and reducing energy applied in the second voltage application process. The first voltage application process includes applying voltage between the covering portion and an electrode through the liquid to dissolve the covering portion in the liquid. The second voltage application process includes reversing relative polarities of the covering portion and the electrode in the first voltage application process and applying voltage between the covering portion and the electrode. Energy applied in the second voltage application process is reduced such that the energy applied is less than energy applied in the first voltage application process of an immediately preceding time.

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: When cleaning is performed to remove kogation, which is deposited on a heat acting portion, by causing an electrochemical reaction through application of a voltage between an upper electrode and an opposing electrode, a wiring located at a periphery of the opposing electrode occludes hydrogen generated during the cleaning, thereby causing hydrogen embrittlement. A unit configured to heat the wiring connected to the opposing electrode is provided, and is driven during the cleaning or after the cleaning, to thereby force hydrogen out of the wiring. Thus, the hydrogen embrittlement of the wiring is suppressed.

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 liquid discharge head has a chamber wall member forming a liquid chamber and a discharge head substrate containing a laminate of a base substrate having a surface for an element generating energy for discharging liquid. A first and second layer is formed contacting the wall. The second layer has adhesiveness with the chamber wall member higher than adhesiveness of the first layer, forming the liquid chamber with the chamber wall member. The first layer has a portion exposed from the second layer as viewed from a first direction orthogonal to the surface and contacting the chamber wail member at a position distant from the liquid chamber in a second direction orthogonal to the inner surface of the wall relative to a portion where the wall and second layer contact, and the length in the second direction of the portion of the first layer is 0.3 ?m or more.

Abstract: A method of cleaning a liquid discharge head, which includes a heat generating resistor that generates thermal energy for discharging a liquid and a covering portion covering the heat generating resistor, includes alternately performing a first voltage application process and a second voltage application process multiple times, and reducing energy applied in the second voltage application process. The first voltage application process includes applying voltage between the covering portion and an electrode through the liquid to dissolve the covering portion in the liquid. The second voltage application process includes reversing relative polarities of the covering portion and the electrode in the first voltage application process and applying voltage between the covering portion and the electrode. Energy applied in the second voltage application process is reduced such that the energy applied is less than energy applied in the first voltage application process of an immediately preceding time.

Abstract: A method of cleaning a liquid discharge head having a substrate provided with a supply port, a heat-generating resistor covered with a covering layer, a liquid chamber forming member configured to form a liquid chamber, and at least one electrode and being configured to discharge liquid supplied to the liquid chamber from the supply port by causing the heat-generating resistor to generate heat, includes applying a voltage to the covering layer and the electrode to cause an electrochemical reaction between the covering layer and the liquid and dissolve the covering layer into the liquid to remove kogations accumulated on the covering layer, in which the covering layer and the electrode to which the voltage is to be applied are not provided in the same liquid chamber having the same cross-sectional area in a direction from the covering layer toward the electrode.

Abstract: A liquid discharge head has a chamber wall member forming a liquid chamber and a discharge head substrate containing a laminate of a base substrate having a surface for an element generating energy for discharging liquid. A first and second layer is formed contacting the wall. The second layer has adhesiveness with the chamber wall member higher than adhesiveness of the first layer, forming the liquid chamber with the chamber wall member. The first layer has a portion exposed from the second layer as viewed from a first direction orthogonal to the surface and contacting the chamber wail member at a position distant from the liquid chamber in a second direction orthogonal to the inner surface of the wall relative to a portion where the wall and second layer contact, and the length in the second direction of the portion of the first layer is 0.3 ?m or more.

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: When cleaning is performed to remove kogation, which is deposited on a heat acting portion, by causing an electrochemical reaction through application of a voltage between an upper electrode and an opposing electrode, a wiring located at a periphery of the opposing electrode occludes hydrogen generated during the cleaning, thereby causing hydrogen embrittlement. A unit configured to heat the wiring connected to the opposing electrode is provided, and is driven during the cleaning or after the cleaning, to thereby force hydrogen out of the wiring. Thus, the hydrogen embrittlement of the wiring is suppressed.

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: 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 made uniform 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 method of cleaning a liquid discharge head having a substrate provided with a supply port, a heat-generating resistor covered with a covering layer, a liquid chamber forming member configured to form a liquid chamber, and at least one electrode and being configured to discharge liquid supplied to the liquid chamber from the supply port by causing the heat-generating resistor to generate heat, includes applying a voltage to the covering layer and the electrode to cause an electrochemical reaction between the covering layer and the liquid and dissolve the covering layer into the liquid to remove kogations accumulated on the covering layer, in which the covering layer and the electrode to which the voltage is to be applied are not provided in the same liquid chamber having the same cross-sectional area in a direction from the covering layer toward the electrode.