A determination method of determining a supply signal to be supplied to a first electrode and a second electrode includes an acquisition step of acquiring, when a predetermined condition is satisfied, first information regarding a liquid ejection characteristic when a first constant potential signal of a first potential is supplied to the second electrode, and second information regarding a liquid ejection characteristic when a second constant potential signal of a second potential different from the first potential is supplied to the second electrode, and a determination step of determining, based on the first information and the second information, the supply signal to be supplied to the first electrode and the second electrode after the predetermined condition is satisfied.

A liquid ejecting head includes a nozzle, first and second pressure chambers communicating with the nozzle, a first driving element configured to change a pressure in the first pressure chamber, and a second driving element configured to change a pressure in the second pressure chamber. A first flow path length of a flow path from the first pressure chamber to the nozzle is shorter than a second flow path length of a flow path from the second pressure chamber to the nozzle. In a driving method of a liquid ejecting head, at least the first and second driving elements are driven to eject a liquid from the nozzle, and a driving timing of the second driving element is earlier than a driving timing of the first driving element.

A liquid ejection apparatus includes a head unit that ejects a liquid, and a control unit that controls an operation of the head unit, wherein the head unit includes a drive signal output circuit that outputs a drive signal, a first substrate on which the drive signal output circuit is provided, and a first ejection head including a first drive element driven by the drive signal, and a first nozzle plate including a first nozzle from which a liquid is ejected by driving the first drive element, wherein the first substrate includes a first face and a second face, wherein the drive signal output circuit is provided on the first face, and wherein a shortest distance between the first nozzle plate and the second face is shorter than a shortest distance between the first nozzle plate and the first face.

Printheads and methods of operation. In one embodiment, a printhead includes a plurality of jetting channels comprising first jetting channels configured to jet a first print fluid and second jetting channels configured to jet a second print fluid, and a driver circuit communicatively coupled to actuators of the jetting channels. The driver circuit receives a drive waveform comprising non-jetting pulses and jetting pulses, and gating signals comprising a first active gating signal designated for jetting the first print fluid, and a second active gating signal designated for jetting the second print fluid. The driver circuit selectively applies the non-jetting pulses and the jetting pulses to actuators of the first jetting channels based on the first active gating signal to jet the first print fluid, and selectively applies the jetting pulses to actuators of the second jetting channels based on the second active gating signal to jet the second print fluid.

A drive controller includes circuitry. The circuitry generates multiple types of drive pulses to be applied to a driver of a liquid discharge head including a valve to open and close a discharge port, and applies the multiple types of drive pulses to the driver to cause the driver to move the valve to open and close the discharge port. Each of the multiple types of drive pulses causes the valve to move away from the discharge port at a valve-opening speed to open the discharge port, keep opening the discharge port for an open time, and move toward the discharge port at a valve-closing speed to close the discharge port. Further, the circuitry generates the multiple types of drive pulses, the open time and the valve-closing speed of which are different, and changes the valve-closing speed according to the open time.

A first switching circuit, a second switching circuit, a first bootstrap circuit that is coupled to the first switching circuit and the second switching circuit, and a smoothing circuit and outputs a drive signal are provided, in which the second switching circuit includes a second gate driver that outputs a third gate signal and a fourth gate signal, a third transistor of which the first voltage is supplied, and which is driven based on the third gate signal, a fourth transistor which is driven based on the fourth gate signal, and a second bootstrap circuit that includes a second capacitive element supplying a third voltage to the second gate driver and coupled to a second output point and the second gate driver, and a second diode of which the first voltage is supplied and which is coupled to the second capacitive element.

A liquid ejecting apparatus includes an ejection section that includes a nozzle which ejects a liquid, a pressure chamber which communicates with the nozzle, and a piezoelectric actuator which imparts a pressure fluctuation to the liquid in the pressure chamber, a drive waveform generation section that generates a drive waveform including a non-ejection vibration pulse which, when supplied to the piezoelectric actuator, imparts the pressure fluctuation to the liquid in the pressure chamber such that the liquid is not ejected from the nozzle and a control section that controls supply of the non-ejection vibration pulse to the piezoelectric actuator in accordance with a temperature of the liquid in the pressure chamber.

An image forming apparatus includes a print head including heating elements for applying a thermal energy to an imaging material, an operation unit configured to operate the plurality of heating elements of the print head by using a first pulse for preheating the color developing layers and a second pulse for developing the colors of the color developing layers, and a generation unit configured to, in a case where a spatial frequency of the image to be recorded based on image data for forming an image on the imaging material is lower than a predetermined frequency, generate the first pulse so that a temperature to be applied to the imaging material by the first pulse is lower than a temperature to be applied to the imaging material in a case where the spatial frequency of the image data is equal to or higher than the predetermined frequency.

In a method of controlling a liquid ejecting apparatus, where the liquid ejecting apparatus includes a pressure chamber that communicates with a nozzle that ejects a liquid, a drive element that changes a pressure of the liquid in the pressure chamber, and a drive circuit that supplies the drive element with an ejection pulse that generates a change in the pressure that ejects the liquid from the nozzle, the method includes specifying a viscosity of the liquid in the nozzle and a surface tension of the liquid in the nozzle from a residual vibration when the pressure of the liquid in the pressure chamber is changed, and controlling a waveform of the ejection pulse according to the viscosity and the surface tension.

There is provided an ink jet recording apparatus including an ink jet head and a drive circuit. The ink jet head forms an image on a recording medium in response to a drive signal applied to multiple piezoelectric elements. The drive signal causes multiple pressure chambers corresponding to the multiple piezoelectric elements to expand or to contract in volume and causes ink in the multiple pressure chambers to be discharged from multiple nozzles. The drive circuit generates a drive signal for discharging multiple liquid droplets to one pixel for combining the multiple liquid droplets together and applies the drive signal to each of the multiple piezoelectric elements of the ink jet head. The drive signal includes multiple discharge pulses which make velocities of tips of respective liquid columns substantially same after a predetermined time from starting of ink discharge from the nozzles.