An ink set is an ink set including a cyan ink C1 which has a fluorescent brightening intensity of 3.0 or greater and an SP value of 12 to 18 (cal/cm.sup.3).sup.1/2, a magenta ink M1 which has a fluorescent brightening intensity of 3.0 or greater and an SP value of 12 to 18 (cal/cm.sup.3).sup.1/2, a yellow ink Y1 which has a fluorescent brightening intensity of 3.0 or greater and an SP value of 12 to 18 (cal/cm.sup.3).sup.1/2, a cyan ink C2 which has a fluorescent brightening intensity of less than 3.0 and an SP value of 12 to 18 (cal/cm.sup.3).sup.1/2, a magenta ink M2 which has a fluorescent brightening intensity of less than 3.0 and an SP value of 12 to 18 (cal/cm.sup.3).sup.1/2, and a yellow ink Y2 which has a fluorescent brightening intensity of less than 3.0 and an SP value of 12 to 18 (cal/cm.sup.3).sup.1/2, in which the SP values are values obtained by a turbidity titration method using a mixed solution of water and acetone.

The head chip includes an actuator plate having ejection channels and non-ejection channels extending in a Y direction and arranged alternately in an X direction, an intermediate plate overlapped with the actuator plate in a Z direction, and provided with communication holes communicated with the ejection channels and through holes communicated with the non-ejection channels, and a nozzle plate overlapped with the intermediate plate in the Z direction in a state of closing the through holes, and provided with nozzle holes which are communicated with the communication holes, jet liquid contained in the ejection channels, and are formed at positions corresponding to the ejection channels. The non-ejection channels are communicated with an outside of the head chip. The through holes are each disposed at an inner side in the X direction of the inner surfaces extending in the Y direction of the non-ejection channel viewed from the Z direction.

There are provided a method of manufacturing a head chip capable of suppressing the occurrence of the failure in the process of forming the actuator plate to thereby increase the yield ratio, and a method of manufacturing a liquid jet head using the above method of manufacturing a head chip. The method of manufacturing a head chip according to an embodiment of the present disclosure is a method of manufacturing a head chip having an actuator plate adapted to apply pressure to liquid so as to jet the liquid. Forming the actuator plate includes forming a plurality of grooves on a surface of a piezoelectric substrate having one end and the other end so as to extend from the one end side toward the other end side, forming a conductive film on the surface of the piezoelectric substrate provided with the plurality of grooves, forming a laser processing area in the conductive film between the grooves adjacent to each other by performing laser processing from a start point on the one end side of the piezoelectric substrate to an end point on the other end side, and forming a surface removal area in at least a part including the start point and the end point out of the surface of the piezoelectric substrate by performing surface removal processing in a direction crossing the direction in which the laser processing is performed.

In one example in accordance with the present disclosure, a fluidic die assembly is described. The fluidic die assembly includes a rigid substrate having a bend therein. A fluidic die is disposed on the rigid substrate. The fluidic die is to eject fluid from a reservoir fluidly coupled to the fluidic die. The fluidic die includes an array of ejection subassemblies. Each ejection subassembly includes an ejection chamber to hold a volume of fluid, an opening, and a fluid actuator to eject a portion of the volume of fluid through the opening. The fluidic die assembly also includes an electrical interface disposed on the rigid substrate to establish an electrical connection between the fluidic die and a controller. The fluidic die and the electrical interface are disposed on a same surface on opposite sides of the bend.

Isolation between electrodes is ensured to enhance resistance to a liquid. A conductive film is provided to a surface of a piezoelectric substrate, and laser processing is performed in a groove extending direction on the conductive film between a first groove and a second groove provided to the piezoelectric substrate to thereby form a laser processing area where the conductive film is removed to the surface of the piezoelectric substrate between the first groove and the second groove. In forming the laser processing area, an irradiation operation with a laser is performed along a plurality of laser processing lines extending in the groove extending direction. Further, the irradiation operation with the laser is performed a plurality of times for each of the laser processing lines, and the irradiation operations with the laser performed along the same laser processing line of the plurality of laser processing lines are performed at a time interval from when ending a previous irradiation operation with the laser to when starting a subsequent irradiation operation with the laser.

An electric current based on electric charge produced on the piezoelectric body changes by going through a first path, a second path, a third path, and a fourth path in this order. On the first path, the electric current becomes larger as the voltage becomes higher. On the second path, the electric current becomes smaller as the voltage becomes higher. On the third path, the electric current becomes larger as the voltage becomes higher. On the fourth path, the electric current becomes smaller as the voltage becomes higher.

A liquid ejection head that includes ejection orifices and is configured by bonding a silicon substrate and a support substrate, flow passages which penetrate a bonding surface between the silicon substrate and the support substrate and through which different types of liquids flow. An in-partition wall space that is open to the bonding surface between the silicon substrate and the support substrate is formed in a partition wall for separating the flow passages. The internal pressure of the in-partition wall space is set to be lower than pressure of the liquid on each of the flow passages.

A microfluidic device has a chamber; a fluidic access channel in fluidic connection with the chamber; a plurality of nozzle apertures in fluidic connection with the chamber; and an actuator, operatively coupled to the fluid containment chamber and configured to cause ejection of drops of fluid through the nozzle apertures in an operating condition of the microfluidic device. The chamber has an elongated shape, with a length and a maximum width, wherein an aspect ratio between the length and the maximum width of the chamber is at least 3:1. The nozzle apertures are configured to generate, in use, a plurality of drops having a total drop volume, wherein a ratio total drop volume to a chamber volume is at least 15%.

In order to provide an inkjet head using an adhesive containing an epoxy resin as a main agent and an imidazole-based curing agent as a curing agent, capable of securing a time for joining work before curing, and having excellent long-term reliability, and a production method for the inkjet head, constituent members are bonded to each other by an adhesive containing at least an epoxy resin as a main agent, a microencapsulated imidazole-based curing agent as a curing agent, and an alcohol that dissolves the microcapsules at a low temperature, and preferably, a residue of the microcapsules dissolved by the alcohol is dispersed in the cured epoxy resin.

A substrate includes a first substrate which has a first substrate through hole, and a second substrate which has a second substrate through hole and directly or indirectly overlaps the first substrate, the first substrate through hole and the second substrate through hole directly or indirectly communicate with each other to form a liquid supply path and a width D1 of an opening portion of the first substrate through hole on a surface of the first substrate closer to the second substrate, a width D2 of an opening portion of the second substrate through hole on a surface of the second substrate closer to the first substrate, a width D3 of an opening portion of the second substrate through hole on a surface of the second substrate farther from the first substrate have a relationship of D1<D2 and D3<D2.