An aqueous ink jet ink composition is for use in an ink jet recording method. The method includes ejecting ink from an ink jet head including nozzles. The nozzles are configured such that a shape of a side wall surface is a scalloped shape in which a scallop width S1 and a notch depth S2 satisfy S1/S2≥4. The aqueous ink jet ink composition includes a pigment and a solvent that contains a specific compound.

A method for manufacturing a device for ejecting a fluid, including the steps of: forming, in a first semiconductor wafer that houses a nozzle of the ejection device, a first structural layer; removing selective portions of the first structural layer to form a first portion of a chamber for containing the fluid; removing, in a second semiconductor wafer that houses an actuator of the ejection device, selective portions of a second structural layer to form a second portion of the chamber; and coupling together the first and second semiconductor wafers so that the first portion directly faces the second portion, thus forming the chamber. The first portion defines a part of volume of the chamber that is larger than a respective part of volume of the chamber defined by the second portion.

An apparatus includes a reservoir and a printhead. The printhead includes a support structure including a deformable portion defining at least a top surface of a pumping chamber, a flow path extending from the reservoir to the pumping chamber to transfer fluid from the reservoir to the pumping chamber, and an actuator disposed on the deformable portion of the support structure. A trench is defined in a top surface of the actuator. Application of a voltage to the actuator causes the actuator to deform along the trench, thereby causing deformation of the deformable portion of the support structure to eject a drop of fluid from the pumping chamber.

An apparatus includes a reservoir and a printhead. The printhead includes a support structure including a deformable portion defining at least a top surface of a pumping chamber, a flow path extending from the reservoir to the pumping chamber to transfer fluid from the reservoir to the pumping chamber, and an actuator disposed on the deformable portion of the support structure. A trench is defined in a top surface of the actuator. Application of a voltage to the actuator causes the actuator to deform along the trench, thereby causing deformation of the deformable portion of the support structure to eject a drop of fluid from the pumping chamber.

A liquid discharge head includes a substrate, a pressure chamber through which a first liquid and a second liquid flow while being in contact with each other, a pressure generating element configured to pressurize the first liquid, and a discharge port configured to discharge the second liquid. The substrate has a first channel and a second channel that each extend through the substrate. The first channel is used to supply the first liquid to the pressure chamber. The second channel is used to supply the second liquid to the pressure chamber. A viscosity of the second liquid is greater than a viscosity of the first liquid. An average cross-section area of the second channel is greater than an average cross-section area of the first channel.

A liquid discharge head includes: a flow passage substrate which is formed with individual flow passages, the individual flow passages including nozzles and pressure chambers communicated with the nozzles respectively; actuators which are fixed to a surface of the flow passage substrate and which overlap with the pressure chambers respectively in an orthogonal direction; and a protective substrate which is fixed to the surface and which covers the actuators. The protective substrate has at least one wall portion for defining actuator accommodating chambers which accommodate the actuators respectively. The wall portion overlaps in the orthogonal direction with a partition wall for partitioning two pressure chambers in the flow passage substrate. The wall portion is adhered to the surface via an adhesive portion. A protective film is formed at portions of the protective substrate and the adhesive portion which define the actuator accommodating chambers.

A liquid discharge head includes a base plate, a cavity plate located on the base plate and including a cavity, and a piezoelectric actuator substrate located on the cavity plate. The cavity plate includes: a first groove located inside a contact region with the piezoelectric actuator substrate and configured to release an adhesive for bonding the cavity plate and the piezoelectric actuator substrate; and a second groove located in a manner to surround the contact region with the piezoelectric actuator substrate and configured to release the adhesive. The base plate includes a third groove configured to open the first groove to the atmosphere. The third groove is configured to communicate between the first groove and the outside through a first hole communicating with the first groove and a second hole located outside the contact region of the cavity plate and the piezoelectric actuator substrate.

A die for a printhead is provided in examples. The die includes a number of fluidic actuator arrays, proximate to a number of fluid feed holes. A number of address lines are disposed proximate to a number of logic circuits on a low-voltage side of the fluid feed holes. An address decoder circuit is coupled to at least a portion of the address lines to select a fluidic actuator in a fluidic actuator array for firing. The address decoder circuit is customized to select a different address for each fluidic actuator in the fluidic actuator array. A logic circuit triggers a driver circuit located in a high-voltage side of the plurality of fluid feed holes opposite the low-voltage side, based, at least in part, on a bit value for the fluidic actuator array, the fluidic actuator selected by the address decoder circuit, and a firing signal.

A liquid discharge head includes: a nozzle plate having a nozzle from which a liquid is to be discharged in a discharge direction, the nozzle having a cylindrical hole having periodical convex portions and concave portions on a sidewall of the nozzle in the discharge direction, a diameter of an outermost portion of the nozzle in the discharge direction being smaller than an average diameter of minimum values and maximum values of diameters of the cylindrical shape. The average diameter is obtained by: Average diameter = (Sum of minimum values + Sum of maximum values) / (Count of minimum values + Count of maximum values).

A liquid discharge head including: a substrate having a liquid supply port; a flow channel forming member that is provided on the substrate and has discharge ports for discharging a liquid and a liquid flow channel that makes the liquid supply port and the discharge ports communicate with each other; and a support member that is provided on the substrate and arranged to be in contact with at least one surface of the flow channel forming member, with the one surface not being in contact with the liquid, wherein the flow channel forming member includes a cured product of a first photosensitive resin composition including a photosensitive resin, the support member includes a cured product of a second photosensitive resin composition including the epoxy resin A having a structure represented by formula (a1) or (a2) below in main chain structure: ##STR00001##
where, n.sub.1 and n.sub.2 represent integers of at least 2.