Abstract: A liquid discharge head includes a nozzle from which a liquid is to be discharged; a pressure chamber communicating with the nozzle; a substrate defining a side wall the pressure chamber; a diaphragm having a surface on the substrate, the diaphragm defining a part of a wall of the pressure chamber and a part of the nozzle; and a piezoelectric element on another surface of the diaphragm opposite to the surface of the diaphragm on the substrate, the piezoelectric element including: a piezoelectric portion configured to vibrate; and a pair of electrodes sandwiching the piezoelectric portion between the pair of electrodes, and an area of at least one of the pair of electrodes of the piezoelectric element is larger than an area of the pressure chamber in a plane of the diaphragm.

Abstract: A liquid discharge head includes a nozzle member. The nozzle member includes a nozzle, a deformable laminar member, and an electromechanical transducer. The nozzle discharges liquid. The deformable laminar member has an opening forming the nozzle. The electromechanical transducer is disposed around the opening. The nozzle member is warped with respect to a discharge-side plane of the nozzle member in a surrounding area of the nozzle when no voltage is applied to the electromechanical transducer.

Abstract: An actuator includes a deformable thin-film member having an opening, an electromechanical conversion element disposed at a periphery of the opening of the deformable thin-film member, an insulating film covering the electromechanical conversion element, a protective film over a surface of the insulating film, the protective film covering the surface of the insulating film and a surface of an electrode wiring connected to the electromechanical conversion element, and an adhesion improving film disposed between the electrode wiring and the protective film.

Abstract: A liquid discharge head includes a channel member including a common chamber configured to store a liquid; a nozzle plate on one surface of the channel member, and multiple tubular partition walls on another surface of the channel member. The nozzle plate includes multiple nozzles from each of which the liquid is dischargeable in a discharge direction, the multiple tubular partition walls are disposed at positions corresponding to the multiple nozzles, the multiple tubular partition walls define multiple individual chambers respectively communicating with the multiple nozzles in the common chamber, and each of the multiple tubular partition walls includes communication channel through which the liquid is supplied from the common chamber to the multiple individual chambers.

Abstract: An inkjet recording method performed by inkjet recording device including nozzle plate with nozzle to eject droplets of ink; recording head including liquid chamber with which the nozzle is in communication, and pressure-generating unit configured to generate pressure in the liquid chamber; and signal-generating unit configured to generate signal applied to the pressure-generating unit, and allowing the droplets of the ink to eject by the pressure generated by the pressure-generating unit according to the signal, wherein the ink has static surface tension of 18.0 mN/m to 27.0 mN/m at 25° C., the ink has receding contact angle on the nozzle plate of less than 50°, the signal has two-step pull pulse for pulling the ink into the nozzle in two-step manner within one printing unit cycle, and the method includes pulling the ink located in proximity to nozzle outlet into the nozzle of the two-step pull pulse, to form meniscus at predetermined position.

Abstract: An image forming apparatus includes a liquid discharging head unit including multiple nozzles to discharge liquid droplets, individual liquid chambers communicated to the multiple nozzles, and pressure generating units to generate pressure applied to a liquid in the individual liquid chambers; and a head drive control unit to generate a common driving waveform including multiple discharging pulses arranged in time series within one driving cycle of discharging liquid droplets of the liquid, to select at least one of the multiple discharging pulses from the common driving waveform, and to apply the selected at least one of the discharging pulses to the pressure generating units. The common driving waveform, generated by the head drive control unit, include at least a first discharging pulse and a second discharging pulse for discharging liquid droplets of same size.

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: An inkjet recording method performed by inkjet recording device including nozzle plate with nozzle to eject droplets of ink; recording head including liquid chamber with which the nozzle is in communication, and pressure-generating unit configured to generate pressure in the liquid chamber; and signal-generating unit configured to generate signal applied to the pressure-generating unit, and allowing the droplets of ink to eject by pressure generated by the pressure-generating unit according to the signal, wherein the ink has static surface tension of 18.0 mN/m to 27.0 mN/m at 25° C., the ink has receding contact angle on the nozzle plate of 50° or more, the signal has two-step pull pulse for pulling the ink into the nozzle in two-step manner within one printing unit cycle, and the method includes pulling the ink located in proximity to nozzle outlet into the nozzle of the two-step pull pulse, to form meniscus at predetermined position.

Abstract: An inkjet recording method performed by inkjet recording device including nozzle plate with nozzle to eject droplets of ink; recording head including liquid chamber with which the nozzle is in communication, and pressure-generating unit configured to generate pressure in the liquid chamber; and signal-generating unit configured to generate signal applied to the pressure-generating unit, and allowing the droplets of the ink to eject by the pressure generated by the pressure-generating unit according to the signal, wherein the ink has static surface tension of 18.0 mN/m to 27.0 mN/m at 25° C., the ink has receding contact angle on the nozzle plate of less than 50°, the signal has two-step pull pulse for pulling the ink into the nozzle in two-step manner within one printing unit cycle, and the method includes pulling the ink located in proximity to nozzle outlet into the nozzle of the two-step pull pulse, to form meniscus at predetermined position.

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: An image forming apparatus includes a liquid discharging head unit including multiple nozzles to discharge liquid droplets, individual liquid chambers communicated to the multiple nozzles, and pressure generating units to generate pressure applied to a liquid in the individual liquid chambers; and a head drive control unit to generate a common driving waveform including multiple discharging pulses arranged in time series within one driving cycle of discharging liquid droplets of the liquid, to select at least one of the multiple discharging pulses from the common driving waveform, and to apply the selected at least one of the discharging pulses to the pressure generating units. The common driving waveform, generated by the head drive control unit, include at least a first discharging pulse and a second discharging pulse for discharging liquid droplets of same size.

Abstract: An image forming apparatus includes a head drive control unit configured to generate a drive waveform including drive pulses in time series, select one or more drive pulses from the drive waveform according to a droplet size, and provide the selected drive pulses to a pressure generation unit configured to generate a pressure for pressurizing a liquid in a liquid chamber. The drive waveform includes a pulling-in waveform element to be selected first. The pulling-in waveform element allows the individual liquid chamber to expand to an expanding state smaller than before start of contraction for droplet ejecting. The drive pulse includes an expanding waveform element that allows the liquid chamber having expanded in the pulling-in waveform element to expand to the expanding state before start of contraction for droplet ejecting, and a contracting waveform element that allows the liquid chamber to contract.

Abstract: An image forming apparatus includes: a liquid droplet discharge head; a pressure generator; and a driving waveform generator configured to generate a driving waveform including a plurality of pulse units for driving the pressure generator for discharging a liquid droplet. The pulse unit includes one or more first pulses, and one or more second pulses arranged after the first pulses for discharging a liquid droplet. The second pulse has a pulse width that is set in advance to generate a resonance with the liquid droplet discharge head. The first pulse has a pulse width different from the pulse width of the second pulse.

Abstract: An inkjet recording method is performed using an inkjet recording device including a recording head provided with a nozzle, a pressure chamber, a pressure generator and a driving signal generator, the method satisfying the following requirements (1) and (2): (1) it is required to use aqueous ink having a dynamic surface tension larger by 10 mN/m or more than a static surface tension when the surface life measured at 25° C. by a maximum foaming pressure method is 15 ms and a dynamic surface tension larger by 5 mN/m or more than a static surface tension when the surface life measured by a maximum foaming pressure method is 1500 ms and (2) it is required that the signals have a drawing pulse in one print period and a meniscus of the aqueous ink is drawn into the nozzle in two stages by the drawing pulse.

Abstract: An image forming apparatus includes: a liquid droplet discharge head; a pressure generator; and a driving waveform generator configured to generate a driving waveform including a plurality of pulse units for driving the pressure generator for discharging a liquid droplet. The pulse unit includes one or more first pulses, and one or more second pulses arranged after the first pulses for discharging a liquid droplet. The second pulse has a pulse width that is set in advance to generate a resonance with the liquid droplet discharge head. The first pulse has a pulse width different from the pulse width of the second pulse.

Abstract: A droplet ejecting apparatus includes a recording head including nozzles, liquid chambers communicating with the respective nozzles and storing ink, and actuators for applying pressure to the respective liquid chambers; and a print control unit configured to generate drive signals for driving the respective actuators to eject droplets from the nozzles. The drive signal includes a first contracting waveform component for ejecting a droplet and a second contracting waveform component for further contracting the liquid chamber after application of the first contracting waveform component but not ejecting a droplet. The second contracting waveform component is output at oscillation-damping timing at which a pressure wave generated by the first contracting waveform component is damped, in a condition where an environmental temperature is high, and is output at resonating timing at which resonance with the generated pressure wave occurs, in a condition where the environmental temperature is low.

Abstract: An inkjet recording method is performed using an inkjet recording device including a recording head provided with a nozzle, a pressure chamber, a pressure generator and a driving signal generator, the method satisfying the following requirements (1) and (2): (1) it is required to use aqueous ink having a dynamic surface tension larger by 10 mN/m or more than a static surface tension when the surface life measured at 25° C. by a maximum foaming pressure method is 15 ms and a dynamic surface tension larger by 5 mN/m or more than a static surface tension when the surface life measured by a maximum foaming pressure method is 1500 ms and (2) it is required that the signals have a drawing pulse in one print period and a meniscus of the aqueous ink is drawn into the nozzle in two stages by the drawing pulse.

Abstract: An image forming apparatus includes a head drive control unit configured to generate a drive waveform including drive pulses in time series, select one or more drive pulses from the drive waveform according to a droplet size, and provide the selected drive pulses to a pressure generation unit configured to generate a pressure for pressurizing a liquid in a liquid chamber. The drive waveform includes a pulling-in waveform element to be selected first. The pulling-in waveform element allows the individual liquid chamber to expand to an expanding state smaller than before start of contraction for droplet ejecting. The drive pulse includes an expanding waveform element that allows the liquid chamber having expanded in the pulling-in waveform element to expand to the expanding state before start of contraction for droplet ejecting, and a contracting waveform element that allows the liquid chamber to contract.

Abstract: A droplet ejecting apparatus includes a recording head including nozzles, liquid chambers communicating with the respective nozzles and storing ink, and actuators for applying pressure to the respective liquid chambers; and a print control unit configured to generate drive signals for driving the respective actuators to eject droplets from the nozzles. The drive signal includes a first contracting waveform component for ejecting a droplet and a second contracting waveform component for further contracting the liquid chamber after application of the first contracting waveform component but not ejecting a droplet. The second contracting waveform component is output at oscillation-damping timing at which a pressure wave generated by the first contracting waveform component is damped, in a condition where an environmental temperature is high, and is output at resonating timing at which resonance with the generated pressure wave occurs, in a condition where the environmental temperature is low.