A drive circuit (100) for driving actuators of a printhead (97) from a common drive waveform has a switching circuit (32) for coupling the common drive waveform to an actuator (1,2), and a timing circuit (10) to control the switching circuit to form a drive pulse from the common drive waveform. The drive pulse is trimmed by controlling a duration (TTRIM) of a step at an intermediate level (VHOLD) in the drive pulse. This can improve the trade-off between available range of trimming and thermal efficiency because the voltage drop across the switching circuit can be reduced, compared to trimming only the height. Decoupling during a flat portion of the common drive waveform can enable the timing of the decoupling to be more relaxed compared to decoupling during a slope. Such relaxing can enable costs, complexity and thermal loading to be reduced.

A liquid ejecting head includes: a piezoelectric element driven with a drive signal; a switch circuit which is provided on a circuit substrate; a pressure chamber which is filled with liquid and changes pressure inside in accordance with the drive by the piezoelectric element; and a reserve chamber which reserves the liquid to be supplied to the pressure chamber. The piezoelectric element is provided in a sealed space defined by a plurality of members including the circuit substrate. The reserve chamber includes a first flow channel and a second flow channel. A first end of the first flow channel communicates with a first end of the second flow channel. A second end of the first flow channel communicates with a second end of the second flow channel. The circuit substrate and switch circuit are provided between the first flow channel and the second flow channel.

A cooling efficiency is increased. An inkjet head is provided with a head main body for jetting ink, a cooling pipe which has corrosion resistance to the ink, and through which the ink for cooling a drive circuit passes, and a cooling member which has higher thermal conductivity than that of the cooling pipe, in which at least a part of the cooling pipe is embedded, and which has recessed parts in at least a part of a portion surrounding the cooling pipe.

There is provided a liquid discharge apparatus, in which a substrate unit includes a first drive circuit that has a first coil, a second drive circuit that has a second coil, a cooling fan that generates an air flow, a wiring substrate having a plurality of rigid members and a flexible member, and a plate-shaped opening member having a first opening and a second opening, the cooling fan generates an air flow in a space where a first front surface of a first rigid member on which the first coil is provided and a second front surface of a second rigid member on which the second coil is provided, and when viewed along a normal direction of the opening member, the first opening overlaps with at least a part of the first coil, and the second opening overlaps with at least a part of the second coil.

A liquid ejecting apparatus includes a head that includes an ejecting portion that, upon receiving a drive signal, ejects liquid; a controller that performs control on circulation of liquid through the first flow passage, wherein the controller performs first control of circulating liquid through the first thermal conductive member and the second thermal conductive member in this order in the first flow passage when an amount of heat generated at the first portion is larger than an amount of heat generated at the second portion, and performs second control of circulating liquid through the second thermal conductive member and the first thermal conductive member in this order in the first flow passage when an amount of heat generated at the second portion is larger than an amount of heat generated at the first portion.

A drive unit is configured to generate a drive signal for driving a liquid ejecting head unit. The drive unit includes a drive board on which a drive circuit configured to generate the drive signal is mounted; a thermal conductive material that is in contact with the drive circuit on an opposite side in relation to the drive board; a water cooling mechanism that is in contact with the thermal conductive material on an opposite side in relation to the drive circuit; a pump that causes liquid in the water cooling mechanism to flow; and a control circuit that controls operation of the pump. The control circuit switches a direction in which the pump causes the liquid to flow between a forward direction and a reverse direction that is an opposite of the forward direction.

There is provided a head module including: a head which has an inlet, a plurality of nozzles, and a plurality of driving elements, and in which the nozzles are aligned in rows in a longitudinal direction of a nozzle surface orthogonal to a attaching/detaching direction of the head module; a plurality of driver ICs; a heat spreader; a flexible substrate; and a rigid substrate. In the attaching/detaching direction, the driver ICs are arranged between the head and the heat spreader; the rigid substrate and the head are arranged side by side in the attaching/detaching direction; the rigid substrate and the heat spreader are arranged side by side in a short direction of the nozzle surface; and the rigid substrate has a thickness along the short direction of the nozzle surface.

A liquid discharging apparatus includes a print head that has a driving element and discharges a liquid, a drive signal generation circuit that generates the drive signal based on a drive signal generation control signal for controlling generation of the drive signal, and a drive circuit substrate on which the drive signal generation circuit is provided. The drive circuit substrate has an input connector that inputs the drive signal generation control signal into the drive circuit substrate and an output connector that outputs the drive signal from the drive circuit substrate. A distance between the input connector and the output connector is shorter than a distance between the drive signal generation circuit and the input connector. The distance between the input connector and the output connector is shorter than a distance between the drive signal generation circuit and the output connector.

A piezoelectric print head includes a piezoelectric element; a nozzle that ejects liquid when the piezoelectric element is driven; a transmission gate that switches between supply and non-supply of a driving signal for driving the piezoelectric element to the piezoelectric element; a history-information memory that holds history information indicating history of ON or OFF of the transmission gate; and a switch-operation stop controller that stops a switch operation that causes the transmission gate to be turned OFF from ON or to be turned ON from OFF, in accordance with the history information.

Various embodiments disclose a method for operating a printer apparatus. The method comprising monitoring a utilization rate of each heating element in a first set of heating elements defined by a print head arrangement. Further, the method comprises generating a utilization dataset based upon monitoring of the utilization rate of each heating element in the first set of heating elements print head arrangement. Furthermore, the method includes analyzing the utilization dataset to identify one or more overutilized heating elements of the first set of heating elements. Additionally, the method includes identifying a second set of heating elements defined by the print head arrangement. The second set of heating elements comprises a portion of the first set of heating elements exclusive of the one or more overutilized heating elements. The method further includes processing a print job. The processed print job utilized the second set of heating elements during printing.