A printing apparatus includes: power supply circuits including at least a first power supply circuit and a second power supply circuit, the power supply circuits having mutually different output voltages; and a head including nozzles, the nozzles forming groups arranged in a first direction, each of the nozzles being associated with any one of the power supply circuits. The groups include a first group and a second group adjacent to each other in the first direction. The first group is formed by nozzles associated with the first power supply circuit and nozzles associated with the second power supply circuit. The second group is formed by nozzles associated with the first power supply circuit and nozzles associated with the second power supply circuit.

A liquid ejecting apparatus includes an ejecting unit that ejects liquid when a drive signal is supplied to the ejecting unit, a drive signal output unit that outputs the drive signal, a cooling unit that cools the drive signal output unit, and a power supply unit that supplies power to the cooling unit. The liquid ejecting apparatus has a first mode in which the drive signal output unit outputs a first drive signal of a first frequency, and a second mode in which the drive signal output unit outputs a second drive signal of a second frequency lower than the first frequency. An amount of power supplied by the power supply unit to the cooling unit in the first mode is larger than an amount of power supplied by the power supply unit to the cooling unit in the second mode.

A liquid jetting apparatus includes: a first head chip having first nozzles arranged in a nozzle arrangement direction; a second head chip having second nozzles arranged in the nozzle arrangement direction, and being arranged to overlap at least partially with the first head chip in an orthogonal direction orthogonal to the nozzle arrangement direction; a controller configured to control the first head chip and the second head chip to jet liquid from the first nozzles and the second nozzles; and power sources having different voltages, respectively. Each of the first nozzles and the second nozzles is driven by voltage supplied from one of the power sources, and the first head chip has a first overlapping portion and the second head chip has a second overlapping portion overlapping with the first overlapping portion in the orthogonal direction.

A drive circuit that drives a piezoelectric device including a drive signal selection control circuit which controls supply of the drive signal to the piezoelectric element, the drive circuit including a drive signal output circuit that outputs the drive signal, a power supply voltage signal output circuit that outputs a power supply voltage signal, and a power supply voltage control circuit that controls supply of the power supply voltage signal to the drive signal selection control circuit, in which the drive signal output circuit includes a modulation circuit, an amplification circuit, a demodulation circuit, a feedback circuit, and a discharge circuit, a first wiring electrically couples the drive signal selection control circuit and the power supply voltage control circuit to each other, and the discharge circuit is electrically coupled to a second wiring through which the drive signal output from the demodulation circuit propagates, through the feedback circuit.

Methods and apparatus to control a heater associated with a printing nozzle are disclosed. A method comprising controlling a heater associated with a printing nozzle to reduce a heat output of the heater based on a determination that the printing nozzle is outside a print area and printing an image on a substrate using other printing nozzles while the heat output of the heater is reduced.

A firing circuit for a thermal inkjet-printing nozzle includes a heater resistor and a switch. The heater resistor heats ink to cause the ink to be ejected from the nozzle. The heater resistor has a first end and a second end, the second end connected to a ground. The switch controls activation of the heater resistor. The switch has a first end connected to a voltage source and a second end connected to the first end of the heater resistor. The switch operates in a constant current mode, such that an at least substantially constant current flows through the heater resistor upon activation.

A drop ejector array device includes a first plurality and a second plurality of drop ejectors that are alternatingly disposed along an array direction on the substrate surface. A voltage input terminal and a current return terminal are disposed on the substrate surface. A first power bus line connects the first plurality to the voltage input terminal. A second power bus line connects the second plurality to the voltage input terminal. The second power bus line is electrically connected to the first power bus line by a primary power bus connector line. A first current return bus line connects the first plurality to the current return terminal. A second current return bus line connects the second plurality to the current return terminal. The second current return bus line is electrically connected to the first current return bus line by a primary current return bus connector line.

A printhead circuit or driving at least two actuating elements has a trim generating circuit for generating a trim signal using a comparator coupled to receive and compare feedback indicative of a present level of a drive voltage, with a configurable reference voltage value. The trim being based on a drive voltage feedback can give a more direct indication of actuating element output than given by timing references. Hence the trim can be more accurate, can be simpler, without accurate digital timing references, and thus costs can be reduced. It can be combined with a cold switch arrangement.

A liquid ejecting apparatus includes a drive element, and a drive circuit that outputs a drive signal that drives the drive element. The drive circuit includes an integrated circuit that outputs an amplification control signal, an amplifier circuit that output an amplified modulation signal, and a demodulation circuit that output the drive signal. The integrated circuit includes a modulation circuit that modulates the base drive signal to output a modulation signal, a discharge circuit that discharges a charge based on the drive signal, a constant voltage output circuit that outputs a DC voltage signal, and an output terminal from which the DC voltage signal is output. The constant voltage output circuit and the discharge circuit are electrically coupled to the output terminal, and a shortest distance between the output terminal and the constant voltage output circuit is shorter than a shortest distance between the output terminal and the discharge circuit.

In an example, an apparatus is described that a fluid ejection device to dispense fluid. A local service controller controls dispensing of the fluid by the fluid ejection device under a direction of a fluid ejection controller. The local service controller also initiates, autonomously of the fluid ejection controller, capping of the fluid ejection device in response to the detection of a failure condition by the local service controller. Capping mechanics are provided to cap the fluid ejection device under the direction of the local service controller.