A die for a printhead is described herein. The die includes a number of fluid feed holes disposed in a line parallel to a longitudinal axis of the die, wherein the fluid feed holes are formed through a substrate of the die. A number of fluidic actuators are proximate to the fluid feed holes to eject fluid received from the plurality of fluid feed holes. The die includes logic circuitry to operate the fluidic actuators, wherein the logic circuitry is disposed on a first side of the plurality of fluid feed holes. Power circuitry to power the plurality of fluidic actuators is disposed on an opposite side of the fluid feed holes from the logic circuitry. Activation traces are disposed between each of the fluid feed holes to couple the logic circuitry to the power circuitry.

A channel structure includes a base body having a first surface, a second surface that is opposite from the first surface, and a side surface that extends in a direction intersecting the first surface. The base body includes a first channel having a supply port into which a liquid is supplied, a liquid storing chamber formed in the first surface and storing the liquid, a second channel having a discharge port through which the liquid in the liquid storing chamber is discharged, and a pressure adjusting unit that supplies the liquid from the first channel to the liquid storing chamber according to pressure in the liquid storing chamber and that located between the first surface and the second surface. The supply port is formed in the second surface of the base body or formed in the side surface of the base body.

A piezoelectric printing device includes a substrate and a piezoelectric plate. A pair of staggered rows of drop ejectors is disposed along a row direction on the substrate. Each drop ejector includes a nozzle in fluid communication with a pressure chamber that is bounded by side walls. The piezoelectric plate has a first surface that is proximate to the pressure chambers. An electrode layer is disposed on an opposing outer second surface of the piezoelectric plate. The electrode layer includes a signal line corresponding to each drop ejector in the pair of staggered rows, and at least one common ground bus connected to ground traces that are aligned over the side walls of each pressure chamber. Each signal line leads to a corresponding signal input pad that is disposed between the staggered rows. The common ground bus extends along the row direction and leads to a ground return pad.

A piezoelectric printhead includes a piezoelectric printing device, a manifold, a U-shaped flexible printed wiring element and an interconnection element. The piezoelectric printing device includes a piezoelectric plate and a substrate with at least one row of drop ejectors; an ink inlet port; signal lines leading to corresponding signal input pads; and ground traces leading to at least one ground return pad. The manifold is fluidically connected to the ink inlet port. The U-shaped flexible printed wiring element includes a device connection region and a pair of legs that extend from the device connection region. The pair of legs includes signal connection lines and at least one ground connection line. The interconnection element is disposed between the device connection region of the U-shaped flexible printing wiring element and a contact layer of the piezoelectric printing device that includes the signal input pads and the at least one ground return pad.

A piezoelectric printing device includes a substrate and a piezoelectric plate. At least one row of drop ejectors is disposed along a row direction. Each drop ejector includes a nozzle in fluid communication with a pressure chamber that is bounded by side walls. The piezoelectric plate has a first surface that is disposed proximate to the first side of the substrate. A bonding layer is disposed between the piezoelectric plate and the substrate. An electrode layer is disposed between the first surface of the piezoelectric plate and the bonding layer. The electrode layer includes a signal line corresponding to each pressure chamber. Each signal line leads to a signal input pad. The electrode layer also includes ground traces disposed on both sides of each pressure chamber. The ground traces are electrically connected to at least one common ground bus that is electrically connected to at least one ground return pad.

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 that is 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 the first side of the substrate. Signal lines and ground traces in the first electrode layer are electrically connected to signal input pads and ground return pad(s) respectively on the second electrode layer through solder joints.

A liquid ejection head includes a channel member, a pressurizing part, a cover member, and a sealing member. The channel member includes an ejection hole, a pressurizing chamber, an ejection hole surface, and a pressurizing chamber surface. The pressurizing chamber is connected with the ejection hole. The ejection hole surface is positioned on the ejection hole side. The pressurizing chamber surface is positioned on the pressurizing chamber side. The pressurizing part is positioned in a pressurizing region in the pressurizing chamber surface. The cover member stands on the channel member. The sealing member seals the cover member and the channel member. The channel member includes a groove positioned in the pressurizing chamber surface but outside the pressurizing region. The cover member is positioned in the groove. Further, the sealing member is positioned between a fixing portion in the cover member which is positioned in the groove and the groove.

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 damper unit includes a damper chamber which has a wall partially composed of a flexible membrane with a rubber elasticity and which is configured to store a liquid; a gas chamber partitioned from the damper chamber by the flexible membrane; a communication portion provided for the gas chamber so that the gas chamber is in communication with an outside of the damper unit; and a one-way valve provided in the communication portion to allow a gas to flow into the gas chamber from the outside of the damper unit and to restrict a gas to flow from the gas chamber to an outside thereof.

A liquid discharge apparatus includes an individual flow passage member; and a common flow passage member joined to the individual flow passage member in a first direction. The individual flow passage member has nozzle groups formed on a surface on a side opposite to the common flow passage member and connecting hole groups formed on a surface on a side of the common flow passage member; and the common flow passage member has manifold flow passages corresponding to the connecting hole groups respectively. Each of the nozzle groups includes nozzles aligned in a second direction orthogonal to the first direction; and each of the connecting hole groups includes connecting holes aligned in the second direction and connected to the nozzles respectively. Each of the manifold flow passages extends in the second direction and is connected to the nozzles via the connecting holes.