A printhead control circuit outputs a first signal to a second wire while a first wire coupled to a first terminal is being supplied with a first voltage signal; outputs a second signal to the second wire coupled to a second terminal while the first wire is being supplied with a second voltage signal; outputs a third signal to the second wire while a third wire coupled to a third terminal is being supplied with a third voltage signal; outputs a fourth signal to the second wire while the third wire is being supplied with a fourth voltage signal; and thereby causes the printhead to perform abnormality detection in response to the first to fourth signals and the first to fourth voltage signals.

A print head ejecting a liquid with respect to a medium and assembled to a liquid ejecting apparatus includes: an ejecting portion ejecting the liquid by receiving a drive signal; an electrically erasable non-volatile memory; and a wireless communication module, in which history information changing in accordance with an operation state of the print head is stored in the non-volatile memory, and the wireless communication module transmits the history information in accordance with a request from an outside.

A liquid discharge apparatus includes a print head discharging a liquid and a control circuit controlling an operation of the print head. the print head includes a connector having a first terminal, a second terminal, a third terminal, and a fourth terminal, a first integrated circuit, a circuit substrate on which the connector and the first integrated circuit are provided and which has first wiring, second wiring, third wiring, fourth wiring, fifth wiring, and sixth wiring, and a first wiring substrate, in which the first wiring electrically couples the first terminal and the first integrated circuit to each other, the fifth wiring electrically couples the first terminal and the first integrated circuit to each other, and the sixth wiring electrically couples the first integrated circuit and the first wiring substrate to each other.

A liquid ejection head unit includes an ejection unit that ejects a liquid, a first wire configured to supply a fixed potential used for driving the ejection unit, a second wire configured to transmit a pulse signal that defines an ejection timing of the liquid in the ejection unit, a first counter whose count value changes based on a potential change in the first wire, a second counter whose count value changes based on a potential change in the second wire, and an ejection restriction unit that restricts an ejection operation of the liquid in the ejection unit according to a count value of the first counter and a count value of the second counter.

A printing system comprises an intermediate transfer member, an image-forming station comprising a print bar disposed over a surface of the ITM, a conveyer for driving rotation of the ITM, a detection system configured to detect foreign matter transported at a detection location upstream of the image-forming station, and a response system operatively coupled to the detection system to respond to the detection of foreign matter by performing at least one collision-prevention action to prevent a potential collision between foreign matter and the print bar.

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.

Systems and methods are provided for. One embodiment is a system that includes an interface configured to receive an image of media printed on with print data, and memory configured to store defect reference data of nozzles belonging to printheads of a printer. The system also includes a print defect controller configured to detect a nozzle defect in the image based on a comparison of the image with the print data, and to determine a type of the nozzle defect based on a comparison of the nozzle defect with the defect reference data.

A method of printing, the method comprising: monitoring operation of first nozzles of a first nozzle array, and if malfunction of a number of first nozzles of the first nozzle array is detected, setting a number of second nozzles of a second nozzle array to a compensation mode. Monitoring operation of the number of second nozzles in the compensation mode and, in response to detecting that a printing parameter of the number of second nozzles differs from a reference printing parameter, adjusting an operation mode parameter of a subset of second nozzles.

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.

A fluidic die including fluid chambers, each including an electrode exposed to an interior of the fluid chamber and each having a corresponding fluid actuator operating at a first voltage level. Monitoring circuitry, operating at a second voltage level lower than the first voltage level, includes a select transistor and a pulldown transistor for each fluid chamber to selectively couple to the electrode, at least the select transistor being a high voltage tolerant transistor to operate at the second voltage in a normal operating condition and having a breakdown voltage level greater than the first voltage level to prevent a fault current from flowing into the select transistor from the electrode in a fault condition if the fluid actuator short-circuits to the electrode.