A liquid circulation device includes a liquid discharge head, a circulation channel through which a liquid is circulated via the liquid discharge head, a first liquid feed pump to supply the liquid to the liquid discharge head in a circulation direction, a second liquid feed pump to collect the liquid from the liquid discharge head in the circulation direction, a filter disposed in the circulation channel upstream from the first liquid feed pump and downstream from the second liquid feed pump in the circulation direction, and a decompression-side reverse channel to bypass the second liquid feed pump. One end of the decompression-side reverse channel is connected to the circulation channel upstream from the second liquid feed pump, and another end of the decompression-side reverse channel is connected to the circulation channel downstream from the filter in the circulation direction.

According to one embodiment, a driving device includes a head driver configured to generate and apply a driving signal to an actuator for ejecting a liquid from a pressure chamber connected to a nozzle, the driving signal including a contraction pulse, the contraction pulse causing the actuator to contract a volume of the pressure chamber, and end application of the contraction pulse when a flow rate of the liquid from the nozzle has a negative value in a liquid ejection direction from the nozzle.

An ink-jet recording apparatus includes: an ink-jet head provided with first and second nozzles for jetting a first ink and a second ink respectively, first and second drive elements which apply energy to the first and second inks respectively; a power supply circuit; and a controller. The controller estimates viscosity of the first ink in the first nozzle, controls the power supply circuit to generate a first drive voltage or a second drive voltage higher than the first drive voltage based on the viscosity of the first ink in the first nozzle estimated, drives the first and second drive elements by use of the drive voltage generated in the power supply circuit, and calculates a jetting amount of the first ink to be jetted from the first nozzle and a jetting amount of the second ink to be jetted from the second nozzle.

A head chip, a liquid jet head, a liquid jet recording device, and a method of manufacturing a head chip each capable of suppressing the variation in ejection performance between the ejection channels without changing the shape of a channel (a drive wall) are provided. In the head chip according to an aspect of the present disclosure, when a region in which the first common electrode part and a second common electrode part are opposed in an X direction to each other across the drive wall, and which is configured to generate an electrical field in the drive wall is defined as an opposed region, a dimension in a Z direction in a first upside common part is formed so as to decrease in a direction from the drive wall located at the first side in the X direction toward the drive wall located at the second side in the X direction among the plurality of drive walls, a dimension in the Z direction in a second upside common part is formed so as to decrease in a direction from the drive wall located at the second side in the X direction toward the drive wall located at the first side in the X direction among the plurality of drive walls, and a dimension in a Y direction in the opposed region decreases in directions from the drive walls located at both end sides in the X direction toward the drive wall located in a central portion in the X direction.

There are provided a head chip, a liquid jet head, a liquid jet recording device, and a method of manufacturing a head chip each capable of ensuring an inter-electrode distance of each of channels while achieving narrowing of a pitch of the channels. In the head chip according to an aspect of the present disclosure, an electrical conducting material removal area in which laser irradiation scars are formed throughout an entire area in an X direction of a portion located between a lower end opening of an ejection channel and a lower end opening of a non-ejection channel is disposed in a portion located between the lower end opening of the ejection channel and the lower end opening of the non-ejection channel in a lower surface of an actuator plate.

An inkjet recording device includes an inkjet discharge head including a nozzle through which ink is discharged, a pressure chamber that communicates to the nozzle, and a pressure generator that generates a pressure change in ink in the pressure chamber according to application of a drive signal to cause ink to be discharged from the nozzle; a driver that is disposed outside the ink discharge head and that is provided with a drive circuit that outputs the drive signal; and a wire that electrically connects the driver with the ink discharge head and through which the drive signal output from the drive circuit and applied to the pressure generator. The driver includes a resistance element provided in a transmission path of the drive signal between the drive circuit and the wire. A magnitude of a resistance value of the resistance element corresponds to a length of the wire.

An inkjet head includes a pressure chamber in which ink is stored, a nozzle plate including a nozzle which connects with the pressure chamber, an actuator configured to change a volume of the pressure chamber, and a drive circuit. The drive circuit, before a printing is performed, outputs, to the actuator for a first time period, a first signal for changing the volume of the pressure chamber without ejecting ink from the nozzle. A second signal for changing the volume of the pressure chamber is then output to the actuator for a second time period such that ink is ejected from the nozzle. A third signal for changing the volume of the pressure chamber to the extent that the ink is not ejected from the nozzle is then output to the actuator for a third time period.

A method of driving an inkjet head having a nozzle and a pressure generator, a plurality of droplets of the ink discharged in response to a series of the drive signals being caused to hit a recording medium to form a single pixel. The method includes, applying, to the pressure generator, the series of the drive signals including a first one of the drive signals that has a first voltage amplitude and a second one of the drive signals that has a second voltage amplitude larger than the first voltage amplitude. A last drive signal in the series of the drive signals is the second one of the drive signals. The first voltage amplitude and the second voltage amplitude are determined such that a ratio of (first voltage amplitude)/(second voltage amplitude) has a value corresponding to a specific gravity of the ink to be discharged.

According to one embodiment, a waveform generating device includes a head driver configured to apply a driving signal to an actuator to discharge ink from a pressure chamber connected to a nozzle, the driving signal including a first portion for reducing an ink pressure in the pressure chamber and a second portion for increasing the ink pressure in the pressure chamber. The second portion is increased in potential by a first potential increase when ink pressure in the pressure chamber is at a maxima and the second portion is further increased in potential by a second potential increase when the ink pressure of the pressure chamber is at a negative value after the first potential increase.

An ink jet head includes a pressure chamber, a nozzle plate including a nozzle, an actuator configured to cause an ink to be discharged from the pressure chamber via the nozzle, and a drive circuit configured to supply to the actuator an expansion signal, having a pulse width equal to a natural vibration cycle of the ink in the pressure chamber, that expands the pressure chamber to an expanded state from an initial state, a release signal, having a pulse width longer than the natural vibration cycle and shorter than three times the natural vibration cycle, that returns the pressure chamber to the initial state from the expanded state, and a contraction signal, having a pulse width longer than the natural vibration cycle and shorter than three times the natural vibration cycle, that contracts the pressure chamber to a contracted state from the initial state.