A liquid ejection head including a base substrate, an ejection port to eject a liquid, a heating element formed above the base substrate that heats the liquid to eject the liquid from the ejection port, a temperature detection element formed above the base substrate that detects a temperature of the liquid, a wiring layer connected to the heating element, a protective layer formed on the base substrate that protects the heating element and the wiring layer from the liquid, and a liquid supply port that penetrates the base substrate and supplies the liquid to the ejection port. When viewed in a direction perpendicular to the base substrate, the temperature detection element is disposed between the heating element and the liquid supply port, and the temperature detection element is formed on the protective layer.

In a head substrate according to an embodiment of the present invention comprises a plurality of nozzles for discharging liquid; a plurality of electrothermal transducers corresponding to the plurality of nozzles; and a plurality of drivers corresponding to the plurality of electrothermal transducers, the substrate has the following configuration. Specifically, it comprises a detection circuit that detects, in a case where one of the plurality of electrothermal transducers is selected, a temperature of the selected transducer to which a first signal is applied to in order to discharge a liquid from a nozzle corresponding to the selected electrothermal transducer, and then a second signal is applied to heat the selected electrothermal transducer.

A cap device includes a cap, an accommodation member, and a cover. The cap covers a nozzle surface of a liquid ejection head. The accommodation member is accommodated in the cap and is fixed to the cap. The accommodation member has a conductivity and receives a voltage that generates a potential difference between the liquid ejection head and the accommodation member. The accommodation member includes a first portion and a second portion connected with each other. The cover covers the second portion of the accommodation member, and has a surface that is co-planar with a surface of the first portion. The cover has a conductivity and receives a voltage that generates a potential difference between the liquid ejection head and the cover.

A recording apparatus includes a carriage equipped with a recording head that ejects ink to a sheet, a drive unit configured to move the carriage in a width direction of the sheet, an encoder configured to detect first information regarding a position or a velocity of the carriage that moves by the drive unit, an acceleration sensor arranged on the carriage and configured to detect second information regarding acceleration of the carriage, and a control unit configured to stop the carriage, based on the first information and the second information.

A liquid ejection head has a nozzle. A controller is configured to: control the liquid ejection head to perform inspection driving, the inspection driving being driving the liquid ejection head to eject liquid from the nozzle for determining whether the nozzle is an abnormal nozzle having an abnormality in ejection of liquid; acquire a determination signal outputted from the signal output device, the determination signal indicating whether the nozzle is the abnormal nozzle; acquire a non-driving signal outputted from the signal output device when the inspection driving is not performed by the liquid ejection head; generate a differential signal by superposing the determination signal and the non-driving signal, the differential signal being a signal indicating a difference between a value of the determination signal and a value of the non-driving signal at each timing; and determine whether the nozzle is the abnormal nozzle based on the differential signal.

According to examples, an apparatus may include fluid chambers that each includes a fluid actuator and an electrode. The fluid actuators may operate at a first voltage level and a monitoring circuitry may operate at a second voltage level that is lower than the first voltage level. The monitoring circuitry may monitor a condition of each fluid chamber based on a selection signal for selecting an electrode associated with a fluid chamber. The monitoring circuitry including an analog multiplexer that includes, for each of the electrodes for the plurality of fluid chambers, a level shifter to receive the selection signal at the second voltage level and to shift a level of the selection signal. The analog multiplexer may also include an analog pass gate to selectively couple the electrode of a respective fluid chamber to the monitoring circuitry based on the level shifted selection signal.

A printing apparatus comprising a printing element substrate, including a substrate including a heating element for heating and discharging liquid and a temperature detecting element for detecting a temperature of the substrate, wherein a detection period, during which a detecting result is obtainable, extends across a plurality of cycles of a latch signal, and a heating enabling signal for discharging the liquid and the latch signal are output such that, in the detection period, an output value of a temperature waveform does not exceed a preset threshold value, the temperature waveform being a temperature waveform of the substrate detected by the temperature detecting element.

A determination signal indicates whether each of a plurality of nozzles of a liquid ejection head is an abnormal nozzle. A controller stores, in a memory, information on a nozzle determined to be the abnormal nozzle among the plurality of nozzles; in response to receiving a particular signal and determining that the memory does not store abnormality flag information and that the number of the abnormal nozzle stored in the memory is larger than a first threshold value, control a recovery device to perform a recovery operation; and in response to receiving the particular signal and determining that the memory stores the abnormality flag information and that the number of the abnormal nozzle is larger than a second threshold value, control the recovery device to perform the recovery operation. The second threshold value is smaller than the first threshold value.

A printing apparatus includes a printing head that includes a plurality of nozzles, each of which ejects an ink pushed out from a pressure chamber by driving of an actuator, a display unit, a detector that generates a residual vibration in the pressure chamber by imparting, to the actuator, a predetermined drive signal that prevents the nozzle from ejecting the ink, and, based on the residual vibration, performs, for each of the plurality of nozzles, defective nozzle detection processing of detecting a defective nozzle having ejection failure, and a display control unit that causes the display unit to display defective nozzle information including a position, in the printing head, of the defective nozzle detected by the detector.

A liquid droplet discharge apparatus includes a discharge head having a nozzle for discharging liquid droplets onto a printing medium and an actuator for applying pressure to liquid in a pressure chamber communicated with the nozzle; a waveform generating circuit for generating driving waveforms of signals for driving the actuator; a surface information acquiring device configured to acquire information about a surface of the printing medium; and a controller. The controller calculates a volume of a recess on the printing medium based on the information acquired by the surface information acquiring device; causes the waveform generating circuit to generate a driving waveform for filling up the recess in accordance with the volume of the recess; and drives the actuator in accordance with the driving waveform generated by the waveform generating circuit such that the liquid droplets are discharged from the nozzle to the recess.