Abstract: A liquid discharge head includes: a nozzle plate having multiple nozzles on a plane of the nozzle plate in a first direction and a second direction orthogonal to the first direction; and a nozzle plate holder adjacent to the nozzle plate in the first direction and configured to hold the nozzle plate, wherein the multiple nozzles in the nozzle plate are arrayed in a third direction inclined with the first direction to form a nozzle array, multiple nozzle arrays, including the nozzle array, arrayed in the nozzle plate in a fourth direction inclined with respect to the second direction, and the nozzle plate has: a nozzle-plate short side inclined with respect to the second direction; and a nozzle-plate long side intersecting the nozzle-plate short side and along the fourth direction, and the nozzle-plate short side and the nozzle-plate long side form an acute angle ?1.

Abstract: A liquid discharge apparatus includes: a liquid discharge head configured to discharge a liquid from a nozzle, the liquid discharge head including: a liquid chamber communicating with the nozzle; a pressure generator configured to deform the liquid chamber to apply pressure to the liquid in the liquid chamber; and circuitry configured to apply a drive signal to the pressure generator to drive the pressure generator, the drive signal including at least one drive pulse. The drive pulse includes: an expansion element to expand the liquid chamber to a first volume; a holding element to hold the first volume of the liquid chamber expanded by the expansion element for a predetermined time; and a contraction element to contract the liquid chamber from the first volume held by the holding element to a second volume.

Abstract: A liquid discharge apparatus includes a liquid discharge head and circuitry. The liquid discharge head includes a nozzle to discharge liquid. The circuitry is configured to: generate and output a common drive waveform including a drive pulse for discharging liquid from the nozzle of the liquid discharge head; select a waveform portion of the drive pulse to be applied to a pressure generating element of the liquid discharge head; and output a selection signal for designating the waveform portion selected. The drive pulse includes at least an expansion waveform element for expanding a pressure chamber of the liquid discharge head and a holding waveform element for holding a state expanded by the expansion waveform element. The selection signal includes a deselection signal for deselecting at least a part of a waveform portion preceding the expansion waveform element having, as a terminal, a state held by the holding waveform element.

Abstract: A liquid discharge apparatus includes a liquid discharge head and circuitry. The liquid discharge head includes a nozzle to discharge liquid. The circuitry is configured to: generate and output a common drive waveform including a drive pulse for discharging liquid from the nozzle of the liquid discharge head; select a waveform portion of the drive pulse to be applied to a pressure generating element of the liquid discharge head; and output a selection signal for designating the waveform portion selected. The drive pulse includes at least an expansion waveform element for expanding a pressure chamber of the liquid discharge head and a holding waveform element for holding a state expanded by the expansion waveform element. The selection signal includes a deselection signal for deselecting at least a part of a waveform portion preceding the expansion waveform element having, as a terminal, a state held by the holding waveform element.

Abstract: An inkjet recording method includes applying one or more drive pulses to a pressure generating device of a recording head including a nozzle plate, a liquid chamber, and discharging droplets of ink from the nozzle. Also, the following conditions 1 and 2 are satisfied. 1. The ink has a dynamic surface tension 10 mN/m or more greater than the static surface tension of the ink when the surface life length is 15 ms and 3 mN/m or more greater than the static surface tension of the ink when the surface life length is 1,500 ms, as measured by maximum bubble pressure technique at 25 degrees C. 2. At least one of the drive pulses has a voltage changing portion to draw in the ink, the voltage changing portion having a changing time of one third or more of the resonance period of the liquid chamber.

Abstract: An inkjet recording method includes applying one or more drive pulses to a pressure generating device of a recording head including a nozzle plate, a liquid chamber, and discharging droplets of ink from the nozzle. Also, the following conditions 1 and 2 are satisfied. 1. The ink has a dynamic surface tension 10 mN/m or more greater than the static surface tension of the ink when the surface life length is 15 ms and 3 mN/m or more greater than the static surface tension of the ink when the surface life length is 1,500 ms, as measured by maximum bubble pressure technique at 25 degrees C. 2. At least one of the drive pulses has a voltage changing portion to draw in the ink, the voltage changing portion having a changing time of one third or more of the resonance period of the liquid chamber.

Abstract: A device to discharge liquid includes a liquid discharging head to discharge the liquid and a drive waveform generating device to generate and output a drive waveform including continuous multiple drive pulses to discharge the liquid from the liquid discharging head that are continuously arranged in chronological order to form a single droplet. The continuous multiple drive pulses include an inflation waveform element to inflate an individual liquid chamber of the liquid discharging head and a contraction waveform element to contract the inflated individual liquid chamber to discharge the liquid. When the wave element between the continuous multiple drive pulses is determined as the holding wave element between pulses, the voltage held by the holding waveform element is higher than the initial voltage of the inflation waveform element of the first drive pulse and the ending voltage of the contraction waveform element of the last drive pulse.

Abstract: A device to discharge liquid includes a liquid discharging head to discharge the liquid and a drive waveform generating device to generate and output a drive waveform including continuous multiple drive pulses to discharge the liquid from the liquid discharging head that are continuously arranged in chronological order to form a single droplet. The continuous multiple drive pulses include an inflation waveform element to inflate an individual liquid chamber of the liquid discharging head and a contraction waveform element to contract the inflated individual liquid chamber to discharge the liquid. When the wave element between the continuous multiple drive pulses is determined as the holding wave element between pulses, the voltage held by the holding waveform element is higher than the initial voltage of the inflation waveform element of the first drive pulse and the ending voltage of the contraction waveform element of the last drive pulse.

Abstract: An inkjet recording method includes supplying ink to a recording head and applying at least one drive pulse to a pressure generating device in the recording head to generate a pressure in a liquid chamber in the recording head to discharge one or more droplets of the ink in the liquid chamber through a nozzle of a nozzle plate in the recording head, wherein the following two conditions are satisfied. The ink has a static surface tension of from 18.0 to 27.0 mN/m at 25 degrees C. Condition 1 The at least one drive pulse has a voltage changing portion for drawing in the ink, the voltage changing portion having a voltage changing time of one third or more of a resonance period of the liquid chamber Condition 2.

Abstract: A liquid discharge apparatus comprises: a liquid discharge head that discharge a liquid by varying a volume of a pressure chamber with an actuator; a control unit that generates a drive signal that varies the volume of the pressure chamber; and an actuator driving unit that drives the actuator with the drive signal, wherein the drive signal includes a plurality of discharge pulses and a non-discharge pulse, the non-discharge pulse is applied at a time point at which a vibration velocity of a composite residual vibration that is of a liquid near a nozzle and that is generated by the discharge pulses peaks in a direction toward an inside or outside of the nozzle, the time point being synchronized with an intermediate time point between a fall time point and a rise time point of the non-discharge pulse.

Abstract: An image forming apparatus includes: a liquid ejecting head including a nozzle that ejects a droplet and a pressure producing unit that produces pressure to pressurize a pressure chamber communicating with the nozzle; and a head drive controlling unit that provides a driving signal to the pressure producing unit. The head drive controlling unit outputs the driving signal including at least a first driving pulse and a second driving pulse to eject droplets and a residual vibration suppressing pulse to suppress residual vibration in the pressure chamber without ejecting a droplet. The residual vibration suppressing pulse is output at such a timing that the residual vibration suppressing pulse has an opposite phase to a composite vibration Vab that is formed by superposition of a meniscus vibration Va generated by droplet ejection with the first driving pulse and a meniscus vibration Vb generated by droplet ejection with the second driving pulse.

Abstract: An image forming apparatus includes a liquid discharge head including plural nozzles to discharge droplets; a plurality of individual liquid chambers; a pressure generator, and a head drive controller. A meniscus oscillation generated in the individual liquid chamber applied with the pressure by the pressure generator has a phase reverse to a phase of a meniscus oscillation generated in the adjacent individual liquid chamber not applied with the pressure by the pressure generator, the common drive waveform generated by the head drive controller includes a common discharge pulse used for forming droplets having at least two sizes and an noncommon discharge pulse used for forming one of the droplets having two sizes, and a pulse interval between the common discharge pulse and the noncommon discharge pulse located right before the common discharge pulse is a time area having a phase reverse to resonance.

Abstract: An image forming apparatus includes a liquid discharge head including plural nozzles to discharge droplets; a plurality of individual liquid chambers; a pressure generator, and a head drive controller. A meniscus oscillation generated in the individual liquid chamber applied with the pressure by the pressure generator has a phase reverse to a phase of a meniscus oscillation generated in the adjacent individual liquid chamber not applied with the pressure by the pressure generator, the common drive waveform generated by the head drive controller includes a common discharge pulse used for forming droplets having at least two sizes and an noncommon discharge pulse used for forming one of the droplets having two sizes, and a pulse interval between the common discharge pulse and the noncommon discharge pulse located right before the common discharge pulse is a time area having a phase reverse to resonance.

Abstract: A liquid discharge apparatus comprises: a liquid discharge head that discharge a liquid by varying a volume of a pressure chamber with an actuator; a control unit that generates a drive signal that varies the volume of the pressure chamber; and an actuator driving unit that drives the actuator with the drive signal, wherein the drive signal includes a plurality of discharge pulses and a non-discharge pulse, the non-discharge pulse is applied at a time point at which a vibration velocity of a composite residual vibration that is of a liquid near a nozzle and that is generated by the discharge pulses peaks in a direction toward an inside or outside of the nozzle, the time point being synchronized with an intermediate time point between a fall time point and a rise time point of the non-discharge pulse.

Abstract: An image forming apparatus includes: a liquid ejecting head including a nozzle that ejects a droplet and a pressure producing unit that produces pressure to pressurize a pressure chamber communicating with the nozzle; and a head drive controlling unit that provides a driving signal to the pressure producing unit. The head drive controlling unit outputs the driving signal including at least a first driving pulse and a second driving pulse to eject droplets and a residual vibration suppressing pulse to suppress residual vibration in the pressure chamber without ejecting a droplet. The residual vibration suppressing pulse is output at such a timing that the residual vibration suppressing pulse has an opposite phase to a composite vibration Vab that is formed by superposition of a meniscus vibration Va generated by droplet ejection with the first driving pulse and a meniscus vibration Vb generated by droplet ejection with the second driving pulse.