Abstract: A liquid ejection head includes: individual passages each having a nozzle; supply liquid passages each communicating with an individual inlet of a corresponding one of the individual passages; return liquid passages each communicating with an individual outlet of a corresponding one of the individual passages; a first supply coupling liquid passage coupling the supply liquid passages to each other and communicating with a first inlet of each of the supply liquid passages; and a second supply coupling liquid passage coupling the supply liquid passages to each other and communicating with a second inlet of each of the supply liquid passages. In each of the supply liquid passages, the individual inlet of the corresponding one of the individual passages is located between the first inlet and the second inlet.

Abstract: A liquid ejection head includes: a plurality of individual passages each having a nozzle; a first supply liquid passage communicating with a first inlet of each of the plurality of individual passages; a second supply liquid passage communicating with a second inlet of each of the plurality of individual passages; a first return liquid passage communicating with a first outlet of each of the plurality of individual passages; and a second return liquid passage communicating with a second outlet of each of the plurality of individual passages.

Abstract: A liquid discharge head includes: individual channels including nozzles respectively; first supply channels through which liquid is supplied to the individual channels; first discharge channels through which the liquid is discharged from the individual channels; a second supply channel through which the liquid is supplied to the first supply channels; a second discharge channel to which the liquid is discharged from the first discharge channels; supply connection openings positioned between the first supply channels and the second supply channel and connecting the first supply channels and the second supply channel; discharge connection openings positioned between the first discharge channels and the second discharge channel and connecting the first discharge channels and the second discharge channel; a supply opening through which the liquid is supplied to the second supply channel; and a discharge opening to which the liquid is discharged from the second discharge channel.

Abstract: A piezoelectric actuator includes a substrate, a first electrode arranged on the substrate, a piezoelectric body stacked on the first electrode, a second electrode superimposed on a surface of the piezoelectric body on a side opposite to the first electrode, and a wiring connected to the first electrode. The first electrode has a connecting portion which is arranged to protrude from an end portion of the piezoelectric body and to which the wiring is connected, and a first conductive portion is provided so that the first conductive portion overlaps with the first electrode while extending over from an area overlapped with the end portion of the piezoelectric body up to the connecting portion of the first electrode.

Abstract: A liquid ejection head includes: individual passages; supply liquid passages; return liquid passages; a supply coupling liquid passage; and a return coupling liquid passage. The supply liquid passages and the return liquid passages extend in an extending direction and are arranged in an arrangement direction. The supply coupling liquid passage and the return coupling liquid passage extend in the arrangement direction, are located on one side of the supply liquid passages and the return liquid passages in the extending direction, and include an overlapping portion at which the supply coupling liquid passage and the return coupling liquid passage overlap each other when viewed in an orthogonal direction. A damper film is provided between the supply coupling liquid passage and the return coupling liquid passage in the orthogonal direction at at least a portion of the overlapping portion.

Abstract: A liquid ejection head, including: first supply passages and first discharge passages extending in a first direction and arranged in a second direction intersecting the first direction; and a second supply passage extending in the second direction and communicating with the first supply passages to supply the liquid thereto and a second discharge passage extending in the second direction and communicating with the first discharge passages to discharge the liquid therefrom, wherein (A) a cross-sectional area of the second supply passage on a plane orthogonal to the second direction at a first portion thereof differs from that at a second portion thereof spaced apart from the first portion in the second direction and/or (B) a cross-sectional area of the second discharge passage on the plane at a first portion thereof differs from that at a second portion thereof spaced apart from the first portion in the second direction.

Abstract: A liquid discharge head includes: individual channels including nozzles respectively; first supply channels through which liquid is supplied to the individual channels; first discharge channels through which the liquid is discharged from the individual channels; a second supply channel through which the liquid is supplied to the first supply channels; a second discharge channel to which the liquid is discharged from the first discharge channels; supply connection openings positioned between the first supply channels and the second supply channel and connecting the first supply channels and the second supply channel; discharge connection openings positioned between the first discharge channels and the second discharge channel and connecting the first discharge channels and the second discharge channel; a supply opening through which the liquid is supplied to the second supply channel; and a discharge opening to which the liquid is discharged from the second discharge channel.

Abstract: A liquid ejection head, including: first supply passages and first discharge passages extending in a first direction and arranged in a second direction intersecting the first direction; and a second supply passage extending in the second direction and communicating with the first supply passages to supply the liquid thereto and a second discharge passage extending in the second direction and communicating with the first discharge passages to discharge the liquid therefrom, wherein (A) a cross-sectional area of the second supply passage on a plane orthogonal to the second direction at a first portion thereof differs from that at a second portion thereof spaced apart from the first portion in the second direction and/or (B) a cross-sectional area of the second discharge passage on the plane at a first portion thereof differs from that at a second portion thereof spaced apart from the first portion in the second direction.

Abstract: A liquid ejection head includes: individual passages each having a nozzle; supply liquid passages each communicating with an individual inlet of a corresponding one of the individual passages; return liquid passages each communicating with an individual outlet of a corresponding one of the individual passages; a first supply coupling liquid passage coupling the supply liquid passages to each other and communicating with a first inlet of each of the supply liquid passages; and a second supply coupling liquid passage coupling the supply liquid passages to each other and communicating with a second inlet of each of the supply liquid passages. In each of the supply liquid passages, the individual inlet of the corresponding one of the individual passages is located between the first inlet and the second inlet.

Abstract: A liquid ejection head includes: a plurality of individual passages each having a nozzle; a first supply liquid passage communicating with a first inlet of each of the plurality of individual passages; a second supply liquid passage communicating with a second inlet of each of the plurality of individual passages; a first return liquid passage communicating with a first outlet of each of the plurality of individual passages; and a second return liquid passage communicating with a second outlet of each of the plurality of individual passages.

Abstract: A liquid ejection head includes: individual passages; supply liquid passages; return liquid passages; a supply coupling liquid passage; and a return coupling liquid passage. The supply liquid passages and the return liquid passages extend in an extending direction and are arranged in an arrangement direction. The supply coupling liquid passage and the return coupling liquid passage extend in the arrangement direction, are located on one side of the supply liquid passages and the return liquid passages in the extending direction, and include an overlapping portion at which the supply coupling liquid passage and the return coupling liquid passage overlap each other when viewed in an orthogonal direction. A damper film is provided between the supply coupling liquid passage and the return coupling liquid passage in the orthogonal direction at at least a portion of the overlapping portion.

Abstract: A method for producing a liquid discharge apparatus includes: forming a first electrode on a film formed on a substrate, forming a piezoelectric part on the first electrode, forming a second electrode on the piezoelectric part, forming a metal part on the film by a metal material except for gold, and forming a gold trace on the metal part to connect to the first electrode.

Abstract: A piezoelectric actuator includes a substrate, a first electrode arranged on the substrate, a piezoelectric body stacked on the first electrode, a second electrode superimposed on a surface of the piezoelectric body on a side opposite to the first electrode, and a wiring connected to the first electrode. The first electrode has a connecting portion which is arranged to protrude from an end portion of the piezoelectric body and to which the wiring is connected, and a first conductive portion is provided so that the first conductive portion overlaps with the first electrode while extending over from an area overlapped with the end portion of the piezoelectric body up to the connecting portion of the first electrode.

Abstract: A piezoelectric actuator includes a substrate, a first electrode arranged on the substrate, a piezoelectric body stacked on the first electrode, a second electrode superimposed on a surface of the piezoelectric body on a side opposite to the first electrode, and a wiring connected to the first electrode. The first electrode has a connecting portion which is arranged to protrude from an end portion of the piezoelectric body and to which the wiring is connected, and a first conductive portion is provided so that the first conductive portion overlaps with the first electrode while extending over from an area overlapped with the end portion of the piezoelectric body up to the connecting portion of the first electrode.

Abstract: A liquid discharge apparatus includes: a pressure chamber; a film covering the pressure chamber; a piezoelectric element disposed on the film and including a piezoelectric part, a first electrode, and a second electrode, wherein the first electrode is disposed on a first side of the piezoelectric part facing the pressure chamber, and the second electrode is disposed on a second side of the piezoelectric part opposite the first side; a gold trace connected to the first electrode or the second electrode; and a first metal part made of a metal material except for gold and positioned between the film and the gold trace. The first metal part is laminated with the gold trace.

Abstract: A liquid discharge apparatus includes: a pressure chamber; a film covering the pressure chamber; a piezoelectric element disposed on the film and including a piezoelectric part, a first electrode, and a second electrode, wherein the first electrode is disposed on a first side of the piezoelectric part facing the pressure chamber, and the second electrode is disposed on a second side of the piezoelectric part opposite the first side; a gold trace connected to the first electrode or the second electrode; and a first metal part made of a metal material except for gold and positioned between the film and the gold trace. The first metal part is laminated with the gold trace.

Abstract: A liquid discharge apparatus includes: a pressure chamber; a film covering the pressure chamber; a piezoelectric element disposed on the film and including a piezoelectric part, a first electrode, and a second electrode, wherein the first electrode is disposed on a first side of the piezoelectric part facing the pressure chamber, and the second electrode is disposed on a second side of the piezoelectric part opposite the first side; a gold trace connected to the first electrode or the second electrode; and a first metal part made of a metal material except for gold and positioned between the film and the gold trace. The first metal part is laminated with the gold trace.

Abstract: There is provided a method for producing a liquid discharge apparatus including a piezoelectric actuator configured to apply pressure to liquid in pressure chambers formed in a channel forming substrate. The producing method includes: forming a stacked body of an ink separation layer, piezoelectric layers, a first electrode, and second electrodes on a base member having a part to be the channel formation substrate; forming a liquid repellent layer which covers the piezoelectric layers and the second electrodes from a side opposite to the ink separation layer; and forming the pressure chambers on the base member. The liquid repellent layer is formed to have residual stress generated in the liquid repellent layer in a state that the pressure chambers are formed, the residual stress having intensity which is smaller than intensity to bend parts of the piezoelectric actuator overlapping with the pressure chambers toward the pressure chambers by 200 nm.

Abstract: A piezoelectric actuator includes a substrate, a first electrode arranged on the substrate, a piezoelectric body stacked on the first electrode, a second electrode superimposed on a surface of the piezoelectric body on a side opposite to the first electrode, and a wiring connected to the first electrode. The first electrode has a connecting portion which is arranged to protrude from an end portion of the piezoelectric body and to which the wiring is connected, and a first conductive portion is provided so that the first conductive portion overlaps with the first electrode while extending over from an area overlapped with the end portion of the piezoelectric body up to the connecting portion of the first electrode.

Abstract: There is provided a method for producing a liquid discharge apparatus including a piezoelectric actuator configured to apply pressure to liquid in pressure chambers formed in a channel forming substrate. The producing method includes: forming a stacked body of an ink separation layer, piezoelectric layers, a first electrode, and second electrodes on a base member having a part to be the channel formation substrate; forming a liquid repellent layer which covers the piezoelectric layers and the second electrodes from a side opposite to the ink separation layer; and forming the pressure chambers on the base member. The liquid repellent layer is formed to have residual stress generated in the liquid repellent layer in a state that the pressure chambers are formed, the residual stress having intensity which is smaller than intensity to bend parts of the piezoelectric actuator overlapping with the pressure chambers toward the pressure chambers by 200 nm.