A liquid discharge head includes an element substrate including a plurality of discharge ports configured to discharge liquid in a discharge direction onto a recording medium, and a heating element configured to heat the liquid, and a flow path member including a supply flow path configured to supply the liquid to the element substrate and a collection flow path configured to collect the liquid from the element substrate. The supply flow path and the collection flow path extend in a longitudinal direction of the flow path member and at least a part of the supply flow path and at least a part of the collection flow path overlap each other when being viewed in the direction parallel to the discharge direction.

An inkjet recording apparatus includes a recording unit, a head unit, a frame, and an angle adjustment mechanism. The angle adjustment mechanism includes an angle adjustment member, a biasing member, and an operation member. The angle adjustment member is in contact with the head unit and is rotatable about an adjustment rotation shaft extending parallel to the unit rotation shaft of the head unit. The biasing member biases the angle adjustment member in a direction of rotating the angle adjustment member in a first direction. The operation member contacts the angle adjustment member and rotates the angle adjustment member in a second direction opposite to the first direction against a biasing force of the biasing member. The angle adjustment member is configured by of a plurality of shaft members.

A liquid discharge head includes multiple nozzles arrayed in two-dimensional matrix, the multiple nozzles configured to discharge a liquid, multiple pressure chambers respectively communicating with the multiple nozzles, multiple common-supply branch channels, each communicating with the multiple pressure chambers, multiple common-collection branch channels, each communicating with the multiple pressure chambers, the multiple common-collection branch channels respectively communicating with the multiple common-supply branch channels through the multiple pressure chambers, a common-supply main channel communicating with each of the multiple common-supply branch channels, a common-collection main channel communicating with each of the multiple common-collection branch channels, and two or more bypass channels communicating with the multiple common-supply branch channels and the multiple common-collection branch channels.

A liquid ejection head includes: head units arranged in a first direction; first individual heat dissipators each corresponding to one of the head units and disposed on a first side of the head unit in a second direction; and a first common heat dissipator disposed on the first side of the head units in the second direction. The first common heat dissipator extends in the first direction and shared among the head units. Each head unit includes: a unit body including an actuator; and a first driver integrated circuit disposed on the first side of the unit body in the second direction. Each of the first individual heat dissipators is disposed between the first driver integrated circuit and the first common heat dissipator of the head unit so as to be in thermal contact with the first driver integrated circuit and the first common heat dissipator.

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.

A method of printing an image from a printhead module having a plurality of horizontal nozzle rows. The method includes the steps of: allocating first dot data for an image line of the image to nozzles in a main row portion of a first nozzle row; allocating second dot data for the image line to nozzles in a dropped row portion of the first nozzle row; sending the first and second dot data to the printhead module and firing respective droplets. Some bits of the first dot data correspond to pixels of the image line aligned with the dropped row portion, and some bits of the second dot data correspond to pixels of the image line aligned with the main row portion.

An ink heating device, which is incorporated in an inkjet printing apparatus, includes: a planar heating member bonded in a state where one surface of the planar heating member is thermally bonded to an outer surface of an ink tank storing ink; an elastic member, having a heat insulation property, is provided on the other surface of the planar heating member and presses the planar heating member against the ink tank; and a hardware processor that performs heating control on the planar heating member in a stepwise manner according to a stop time of a main body of the printing apparatus at a time of starting the main body of the printing apparatus.

A recording device includes a recording head including a first nozzle group that ejects a first ink and a second nozzle group that ejects a second ink having a color different from that of the first ink, a moving unit that relatively moves the recording head and a medium in a moving direction intersecting with a nozzle alignment direction, and a control unit. The recording head includes a first nozzle range in which a distance between the first nozzle group and the second nozzle group in the moving direction is a first distance and a second nozzle range in which the distance is a second distance greater than the first distance. In a case in which recording is performed on a medium using nozzles belonging to the second nozzle range, when recording is performed with a secondary color through ejection of the first ink and the second ink.

A liquid circulation device includes a circulation passage, a liquid feeding device, a pressure sensor, and control circuitry. Through the circulation passage, liquid circulates to be supplied to and collected from a circulatory liquid discharge head. The liquid feeding device is configured to circulate the liquid through the circulation passage. The pressure sensor is configured to detect a pressure of the circulation passage. The control circuitry configured to acquire a characteristic indicating a relationship among a drive amount of the liquid feeding device, discharge information of the liquid discharged from the liquid discharge head, and a pressure detection value of the circulation passage; and change, based on the characteristic acquired, at least one of a control parameter and a calculation expression used to control the liquid feeding device.

A liquid ejecting apparatus includes: an acquisition unit that acquires first vibration information on an inspection target ejecting portion out of the ejecting portions concerning a vibration generated in a first detection period included in a first period in which the liquid ejecting apparatus forms a first printed image on the medium, and acquires second vibration information on the inspection target ejecting portion concerning a vibration generated in a second detection period corresponding to the first detection period, the second detection period being included in a second period that starts after completion of the first period, in which the liquid ejecting apparatus forms a second printed image related to the first printed image on the medium. The liquid ejecting apparatus also includes an inspection unit that inspects a ejection state of the liquid from the inspection target ejecting portion based on the first vibration information and the second vibration information.