Abstract: A liquid discharge head includes a piezoelectric element and a flexible circuit board to supply a driving signal and a common-electrode signal to the piezoelectric element. The piezoelectric element includes multiple drive portions arranged in a first direction; multiple non-drive portions; and multiple dummy drive portions at each portion between the multiple drive portions and the multiple non-drive portions in the first direction; a first electrode configured to supply the driving signal to the multiple drive portions; and a second electrode configured to supply the common-electrode signal to the multiple drive portions. The flexible circuit board includes a third electrode configured to supply the common-electrode signal to the multiple drive portions. Each of the multiple non-drive portions and the multiple dummy drive portions include a common-electrode joint connected to the third electrode of the flexible circuit board.

Abstract: A liquid discharge head includes a plurality of pressure generating elements configured to generate pressure to discharge a liquid, a plurality of wirings configured to transmit a drive signal to the plurality of pressure generating elements, respectively, a plurality of integrated circuits configured to drive the plurality of pressure generating elements, respectively, the plurality of integrated circuits being provided on the plurality of wirings, respectively, and a heat sink configured to contact the plurality of integrated circuits to dissipate heat in the plurality of integrated circuits. The heat sink includes a first dissipation part that directly contacts one of the plurality of integrated circuits, and a second dissipating part that contacts another of the plurality of integrated circuits via one of the plurality of wirings.

Abstract: A liquid discharge head includes a plurality of pressure generating elements configured to generate pressure to discharge a liquid, a plurality of wirings configured to transmit a drive signal to the plurality of pressure generating elements, respectively, a plurality of integrated circuits configured to drive the plurality of pressure generating elements, respectively, the plurality of integrated circuits being provided on the plurality of wirings, respectively, and a heat sink configured to contact the plurality of integrated circuits to dissipate heat in the plurality of integrated circuits. The heat sink includes a first dissipation part that directly contacts one of the plurality of integrated circuits, and a second dissipating part that contacts another of the plurality of integrated circuits via one of the plurality of wirings.

Abstract: A liquid discharge head includes a nozzle plate in which a plurality of nozzles to discharge a liquid is formed in a nozzle array direction, a channel plate including partition walls to form a plurality of individual chambers communicating with the plurality of nozzles, respectively, a diaphragm bonded to the channel plate to form a wall of the plurality of individual chambers, and a plurality of electromechanical transducers bonded to the diaphragm to deform the diaphragm to generate a pressure in the plurality of individual chambers, and a cycle of vibration of natural vibration generated in the liquid in the plurality of individual chambers is equal to or larger than a cycle of a primary mode of lateral vibration of the plurality of electromechanical transducers in the nozzle array direction.

Abstract: A liquid discharge head includes a nozzle plate in which a plurality of nozzles to discharge a liquid is formed in a nozzle array direction, a channel plate including partition walls to form a plurality of individual chambers communicating with the plurality of nozzles, respectively, a diaphragm bonded to the channel plate to form a wall of the plurality of individual chambers, and a plurality of electromechanical transducers bonded to the diaphragm to deform the diaphragm to generate a pressure in the plurality of individual chambers, and a cycle of vibration of natural vibration generated in the liquid in the plurality of individual chambers is equal to or larger than a cycle of a primary mode of lateral vibration of the plurality of electromechanical transducers in the nozzle array direction.

Abstract: A liquid discharge head includes a plurality of nozzles from which liquid is discharged, a plurality of individual-liquid-chambers communicating with the plurality of nozzles, respectively, a plurality of individual-drainage-channels communicating with the plurality of individual-liquid-chambers, respectively, a drainage-side common-liquid-chamber communicating with each of the plurality of individual-drainage-channels, a filter having filter holes and disposed between the plurality of individual-drainage-channels and the drainage-side common-liquid-chamber, and an intermediate-drainage-channel disposed between the filter and the plurality of individual-drainage-channels. The intermediate-drainage-channel faces the filter and communicates with two or more of the plurality of individual-drainage-channels.

Abstract: A liquid-discharging head includes a pressure-generating element configured to be actuated to apply pressure on liquid in a pressure chamber from which the liquid is discharged through a nozzle, an actuation controller configured to control actuation of the pressure-generating element, a heat-releasing member configured to contact the actuation controller, and a cover member configured to cover the actuation controller and part of the heat-releasing member. The heat-releasing member includes a first heat-releasing member and a second heat-releasing member. The first heat-releasing member is arranged outside the cover member and has a surface exposed to external air. The second heat-releasing member is arranged inside the cover member and has a first end portion to contact the actuation controller. The first heat-releasing member and the second heat-releasing member are arranged to contact each other.

Abstract: A liquid discharge head includes a plurality of nozzles from which liquid is discharged, a plurality of individual-liquid-chambers communicating with the plurality of nozzles, respectively, a plurality of individual-drainage-channels communicating with the plurality of individual-liquid-chambers, respectively, a drainage-side common-liquid-chamber communicating with each of the plurality of individual-drainage-channels, a filter having filter holes and disposed between the plurality of individual-drainage-channels and the drainage-side common-liquid-chamber, and an intermediate-drainage-channel disposed between the filter and the plurality of individual-drainage-channels. The intermediate-drainage-channel faces the filter and communicates with two or more of the plurality of individual-drainage-channels.

Abstract: A liquid-discharging head includes a pressure-generating element configured to be actuated to apply pressure on liquid in a pressure chamber from which the liquid is discharged through a nozzle, an actuation controller configured to control actuation of the pressure-generating element, a heat-releasing member configured to contact the actuation controller, and a cover member configured to cover the actuation controller and part of the heat-releasing member. The heat-releasing member includes a first heat-releasing member and a second heat-releasing member. The first heat-releasing member is arranged outside the cover member and has a surface exposed to external air. The second heat-releasing member is arranged inside the cover member and has a first end portion to contact the actuation controller. The first heat-releasing member and the second heat-releasing member are arranged to contact each other.

Abstract: A liquid discharging head includes a substrate, at least two heads arranged on the substrate in a longitudinal direction of the liquid discharging head. Each of the at least two heads includes a plurality of nozzles configured to discharge a liquid, and a plurality of pressure generators corresponding to the plurality of nozzles, wherein a drive signal imparted to the pressure generators is supplied to each of the at least two heads from one side (supplying side) in an arrangement direction of the pressure generators, two adjacent heads of the at least two heads are arranged with the far side of each of the two adjacent heads from the one side placed next to each other or the near side thereof placed next to each other, and the far side of each of the two adjacent heads is mutually connected with each other.

Abstract: A control device of controlling a liquid droplet ejection head includes a head substrate; a head controller applying a drive voltage to the head substrate to control the ejection of liquid droplets; a relay substrate connecting the head substrate and the head controller; a main-body controller controlling the head controller; and a voltage conversion circuit disposed in the relay substrate. Further, the voltage conversion circuit converts a resistance value in accordance with a temperature of the head substrate into an output voltage, the relay substrate inputs the output voltage into the main-body controller, and the main-body controller detects the temperature based on the output voltage and determines the drive voltage based on the detected temperature.

Abstract: Disclosed is a driving device of a liquid-jet head having a piezoelectric device arranged for each of nozzles and having mutually facing electrodes. The driving device includes switching devices connected in parallel to each other, one of the electrodes being connected to first ends of the switching devices for selectively ON/OFF controlling the switching devices while the other electrode is connected to a reference potential, a driving signal source to generate a driving signal connected to second ends of the switching devices, and a control unit to switch the driving signal to ON or OFF control the switching devices. At least one of the switching devices has electrically conducting properties for not ejecting a liquid drop from the nozzle with a driving signal being applied to the switching device in an ON-controlled status, and the switching devices are all ON-controlled for causing the nozzles to eject liquid drops.

Abstract: A control device of controlling a liquid droplet ejection head includes a head substrate; a head controller applying a drive voltage to the head substrate to control the ejection of liquid droplets; a relay substrate connecting the head substrate and the head controller; a main-body controller controlling the head controller; and a voltage conversion circuit disposed in the relay substrate. Further, the voltage conversion circuit converts a resistance value in accordance with a temperature of the head substrate into an output voltage, the relay substrate inputs the output voltage into the main-body controller, and the main-body controller detects the temperature based on the output voltage and determines the drive voltage based on the detected temperature.

Abstract: Disclosed is a driving device of a liquid-jet head having a piezoelectric device arranged for each of nozzles and having mutually facing electrodes. The driving device includes switching devices connected in parallel to each other, one of the electrodes being connected to first ends of the switching devices for selectively ON/OFF controlling the switching devices while the other electrode is connected to a reference potential, a driving signal source to generate a driving signal connected to second ends of the switching devices, and a control unit to switch the driving signal to ON or OFF control the switching devices. At least one of the switching devices has electrically conducting properties for not ejecting a liquid drop from the nozzle with a driving signal being applied to the switching device in an ON-controlled status, and the switching devices are all ON-controlled for causing the nozzles to eject liquid drops.

Abstract: A liquid-ejection head unit includes a head, an electric-circuit board, electronic components, and a storage tank. The head includes a frame member and ejects droplets of liquid. The electronic components are mounted on the electric-circuit board and connected to the head. The storage tank stores liquid supplied to the head. The electric-circuit board is disposed between the frame member of the head and the storage tank to form a single multi-layered structure. The electronic components of the electric-circuit board are accommodated in at least one of a first internal space defined by the frame member of the head and the electric-circuit board and a second internal space defined by the electric-circuit board and the storage tank.

Abstract: A liquid-ejection head unit includes a head, an electric-circuit board, electronic components, and a storage tank. The head includes a frame member and ejects droplets of liquid. The electronic components are mounted on the electric-circuit board and connected to the head. The storage tank stores liquid supplied to the head. The electric-circuit board is disposed between the frame member of the head and the storage tank to form a single multi-layered structure. The electronic components of the electric-circuit board are accommodated in at least one of a first internal space defined by the frame member of the head and the electric-circuit board and a second internal space defined by the electric-circuit board and the storage tank.

Abstract: In a dot line printer having a plurality of print hammers which are arranged to print a plurality of dot lines simultaneously when a hammer bank on which the print hammers are mounted performs one scan from one extreme to another, the dot lines originally assigned to the print hammers for printing are changed provided that a particular print hammer is driven an undue number of times when the originally assigned positions of the print hammers are maintained in the subsequent scans of the hammer bank.

Abstract: To prevent effective print speed from being lowered, a counter is provided for each of a plurality of print hammers. A number of times a print hammer is driven during one print phase having a predetermined period of time is counted by the counter. The counted value is compared with a reference value, and when the counted value has reached the reference value during the print phase, driving of the print hammer is halted until the end of the print phase. A reference value is changed based on the number of times the print hammer is driven during a previous print phase immediately before the present print phase. The reference value represents an allowable number the print hammer can be driven during each of successive print phases.

Abstract: To prevent undue elevation of temperature in a hammer assembly but to maintain the maximum printing speed, when a scheduled number of drivings at which print hammers are to be driven during one scan of a manner bank which follows the currently performing scan, exceeds a first reference number, one dot line printing is completed with a plurality of scans of the hammer bank so that dot line print density in each scan of the hammer bank does not exceed, for example, 35%. If, however, high density printing exceeding 25% continues for an extended period of time more than one scan time, the printing operation is temporarily halted.