A liquid-droplet ejecting apparatus includes: N nozzles; N driving elements; M power supply circuits that create a driving signal to be selectively supplied to the N driving elements; and N selecting circuits that selectively connect one of the M power supply circuits to a corresponding one of the N driving elements. The N driving elements are connected to the M power supply circuits in a first combination until a particular condition is satisfied. The first combination is a combination between the M power supply circuits and an M driving element groups, into which the N driving elements are divided based on a voltage of the supplied driving signal. The N driving elements are connected to the M power supply circuits in a second combination after the particular condition is satisfied. The second combination is another combination between the M driving element groups and the M power supply circuits.

A printing apparatus that performs printing by using a print head includes a first power supply, a second power supply, and a control unit. The first power supply supplies a first voltage to the print head through a first supply line. The second power supply supplies a second voltage to the print head through a second supply line. The control unit supplies the first voltage from the first power supply without supplying a voltage from the second power supply at the time of an inspection of the print head, and executes a process action concerning a current leakage when a voltage exceeding a predetermined first threshold is generated on the second supply line.

A fluidic die may include a fluid actuator comprising an electrical resistor, a power node to supply electrical current to the resistor to drive the fluid actuator, a low side switch transistor connected to a ground node and having a gate to control the flow of electrical current through the resistor, a voltage regulator to receive electrical power from the power node and to output a predetermined voltage and a level shifter to control to output a low side switch transistor gate drive voltage using the predetermined voltage and based upon control signals to control the gate to control fluid displacement by the fluid actuator. The predetermined voltage is greater than a voltage of the control signals and is independent of a resistance of the ground node.

A printing apparatus includes: power supply circuits including at least first and second power supply circuits; a head including nozzles, the nozzles forming groups arranged in a first direction, each of the groups including nozzle arrays arranged in the first direction, each of the nozzle arrays extending in a second direction intersecting with the first direction, each of the nozzles being associated with any of the power supply circuits; and a memory storing information. The information indicates correspondence relationships between the nozzles and the power supply circuits, between the nozzles and the groups, and between the nozzles and the nozzle arrays. Printing is performed by driving the head based on the information. The groups include a first group and a second group adjacent to each other in the first direction. The first group includes a first nozzle array adjacent to the second group in the first direction.

A print head control circuit controls an operation of a print head that includes a nozzle plate and has a self-diagnosis function performed based on signals input from a first coupling point, a second coupling point, a third coupling point, and a fourth coupling point. The print head control circuit includes a first cable that includes a first power voltage signal propagation wiring for propagating a first power voltage signal, and a second cable that includes a first diagnosis signal propagation wiring for propagating a first diagnosis signal input to the first coupling point. A shortest distance between the nozzle plate and the first cable is longer than a shortest distance between the nozzle plate and the second cable.

A liquid ejecting apparatus includes a liquid discharging head having a nozzle and a piezoelectric element, a driving signal generating circuit, a reference voltage signal generating circuit, a substrate on which the driving signal generating circuit and the reference voltage signal generating circuit are provided, a first wire, a second wire, and a coil, in which the driving signal generating circuit generates a driving signal, the reference voltage signal generating circuit generates a reference voltage signal, the piezoelectric element is driven based on the driving signal supplied to one end of the piezoelectric element and the reference voltage signal supplied to the other end of the piezoelectric element, the first wire propagates the driving signal to the one end, and the second wire propagates the reference voltage signal to the other end through the coil.

A drive circuit for driving a first drive element having a first terminal and a second terminal and driving a second drive element having a third terminal and a fourth terminal, includes a first drive signal output circuit that is electrically coupled to the first terminal and outputs a first drive signal, a second drive signal output circuit that is electrically coupled to the third terminal and outputs a second drive signal, a reference voltage signal output circuit that outputs a reference voltage signal having a constant reference voltage value, and a first switch circuit having one end electrically coupled to an output terminal of the reference voltage signal output circuit and the other end electrically coupled to the second terminal and the fourth terminal. The first switch circuit switches whether or not to supply a second constant voltage signal to the second terminal and the fourth terminal.

A second power is lower than a first power to be supplied during a printing operation. In a case where the second power is supplied to a print head through a cable as a drive power for the nozzles in the print head, the change in voltage of the second power is detected. The nozzles in the nozzle arrays are driven on an array-by-array basis with the second power on the basis of a control signal, and whether there is breakage in the cable is detected on the basis of the result of the detection of the change in voltage of the second power during the driving of the nozzles.

In a print head control circuit, a first diagnostic signal wiring group includes first diagnostic signal propagation wiring that propagates a first diagnostic signal, and second diagnostic signal propagation wiring that propagates a second diagnostic signal, the first drive signal wiring group and the second drive signal wiring group propagate a first drive signal and a second drive signal that cause liquid to be discharged, in a first cable, the first diagnostic signal wiring group is provided between the first drive signal wiring group and the second drive signal wiring group.

A droplet ejecting device includes: a head including N-number drive elements; a driving circuit including N-number waveform signal selectors and N-number power supply circuit selectors; a plurality of power supply circuits connected to the driving circuit; and a control circuit. Each waveform signal selector selects a waveform signal to be outputted to the corresponding drive element from among a plurality of types of waveform signals. Each power supply circuit selectors selects a power supply circuit to be connected to the drive elements from among the plurality of power supply circuits. The control circuit serially transmits, to the driving circuit via a single control line: N-number items of waveform signal designation information each of which designates the waveform signal to be outputted to the corresponding drive element; and N-number items of power supply designation information each of which designates the power supply circuit to be connected to the corresponding drive element.