A liquid ejection head includes a substrate; an energy generator that is provided on the substrate; an electrode portion that is provided on the substrate; a liquid ejection face that is provided near a surface of the substrate having the electrode portion; and flexible printed circuits including a conductive pattern and a base material having a first surface and a second surface, the first surface having the conductive pattern, the second surface being provided on the opposite side from the first surface. The base material of the flexible printed circuits has a leading region from the terminal end of a region having the conductive pattern to an end of the base material near the energy generator, without formation of the conductive pattern in the leading region, and at least a part of the second surface of the leading region inclines toward the substrate.

There is provided a liquid discharge head including: a pressure chamber plate including a plurality of pressure chambers and a vibration film, a piezoelectric actuator, and a protective plate covering the plurality of piezoelectric elements. The plurality of piezoelectric elements include a piezoelectric layer that is common to the plurality of pressure chambers. A circular recess and an island-like piezoelectric layer residual part enclosed by the circular recess are provided in a portion of the piezoelectric layer overlapping with partition walls of the pressure chamber plate. A residual overlapping part of the protective plate overlaps in a thickness direction with the island-like residual part, and is pressed on the island-like residual part of the piezoelectric actuator.

A fluid ejection apparatus executes a cleaning process and an ejection operation of ejecting fluid from ejection ports while causing the fluid to flow from a supply port to a fluid collection port of a flow channel provided in a fluid ejection head. Moreover, the fluid ejection apparatus adjusts a flow rate of the fluid flowing in the flow channel to a first flow rate during the ejection operation and adjusts the flow rate of the fluid flowing in the flow channel to a second flow rate higher than the first flow rate at least during the cleaning process.

There is provided a piezoelectric actuator including a vibration plate; first and second piezoelectric layers; individual electrodes; a first common electrode arranged between the vibration plate and the first piezoelectric layer; a second common electrode arranged between the first piezoelectric layer and the second piezoelectric layer; a first surface electrode which is arranged on the second piezoelectric layer and which is in conduction with the first common electrode; and a second surface electrode which is arranged on the second piezoelectric layer and which is in conduction with the second common electrode. The piezoelectric actuator further comprises an inspection electrode which is arranged on the second piezoelectric layer at an end portion of the second piezoelectric layer, which is overlapped with the one of the first and second common electrodes, and which is not in conduction with any of the individual electrodes, and the first and second common electrodes.

There is provided piezoelectric actuator including: vibration plate; first and second piezoelectric layers; a plurality of individual electrodes arranged on actuator surface, of the second piezoelectric layer, on first side in first direction of the second piezoelectric layer; first and second common electrodes; first surface electrode arranged on the actuator surface at an end portion in second direction orthogonal to the first direction; second surface electrode arranged on the actuator surface; and non-conductive electrodes arranged at end portions in the second direction of at least two of the actuator surface, and the first and second boundary surfaces, and which are not in conduction with any of the individual electrodes, and the first and second common electrodes. The non-conductive electrodes are arranged at least in an area of an end portion in the second direction of a stack of the vibration plate, and the first and second piezoelectric layers.

Ink is circulated through a circulation flow path between a print head and an ink tank. Detection operation for detecting an ink ejection state in an ejection opening in the print head is performed. The ink circulation and the detection operation are simultaneously performed by performing the detection operation in response to a start of the ink circulation.

A piezoelectric printing device includes a piezoelectric plate and a substrate with at least one row of drop ejectors. Each drop ejector includes a pressure chamber on a first side of the substrate and a nozzle on a second side of the substrate. The piezoelectric plate is attached to the substrate by a bonding layer. A first electrode layer is disposed on a first surface of the piezoelectric plate proximate to the first side of the substrate. The first electrode layer includes signal lines and ground traces corresponding to each pressure chamber. A second electrode layer including signal input pads and ground return pads is disposed on an outer second side of the piezoelectric plate. Signal lines and ground traces in the first electrode layer are electrically connected to signal input pads and ground return pads respectively on the second electrode layer through conductive vias.

A bifurcation path and a flow path which communicates with the head main body through the bifurcation path are provided. The bifurcation path includes an upstream-side path and a downstream-side path. In a plan view of a flow-path forming surface including the bifurcation path and the flow path, the flow path is disposed in a state where an angle between a flowing direction in the flow path and a flowing direction in the downstream-side path is an acute angle. In addition, an angle between a first wall surface of the flow path, which is the wall surface located downstream from the upstream-side path, and a second wall surface of the upstream-side path, which is the wall surface connected to the first wall surface, is equal to or less than 90°. Furthermore, the second wall surface of the upstream-side path has an R shape.

A printing apparatus for printing using a printhead including a plurality of nozzles each configured to discharge ink and a plurality of sensors, corresponding to the plurality of nozzles, for detecting a discharge state of ink from the plurality of nozzles, judges a discharge state. More specifically, the apparatus prints, based on print data, an image by driving the printhead under a first drive condition to discharge the ink from the printhead to a first area, discharges ink to a second area different from the first area by driving the printhead, based on inspection data, under a second drive condition different from the first drive condition, and judges a discharge state of each nozzle by monitoring an output from each sensor at a timing of driving the printhead under the second drive condition.

A liquid ejection head includes an ejection orifice for ejecting a liquid; a substrate on which an energy-generating element and an insulating layer are formed on a first surface; a liquid inflow path which penetrates the substrate and makes a liquid flow in a flow path disposed between the ejection orifice and the element; and a liquid outflow path which penetrates the substrate and makes the liquid flow out of the flow path. The liquid inflow path and the liquid outflow path have a first opening and a second opening penetrating the insulating layer on the first surface of the substrate, the ejection orifice is disposed between the liquid inflow path and the liquid outflow path, and an ejection orifice side end of the second opening is formed closer to the ejection orifice than an ejection orifice side end of the first opening.