A liquid circulation device includes a circulation passage, a liquid feeding device, a pressure sensor, and control circuitry. Through the circulation passage, liquid circulates to be supplied to and collected from a circulatory liquid discharge head. The liquid feeding device is configured to circulate the liquid through the circulation passage. The pressure sensor is configured to detect a pressure of the circulation passage. The control circuitry configured to acquire a characteristic indicating a relationship among a drive amount of the liquid feeding device, discharge information of the liquid discharged from the liquid discharge head, and a pressure detection value of the circulation passage; and change, based on the characteristic acquired, at least one of a control parameter and a calculation expression used to control the liquid feeding device.

A wide array printhead module includes a plurality of printhead die. Each of the printhead die includes a number of sensors to measure properties of a number of elements associated with the printhead die. The wide array printhead module further includes an application specific integrated circuit (ASIC) to command and control each of the printhead die. The ASIC is located off any of the printhead die.

A fluid ejection device including a printhead die having a plurality of layers, including a single metal layer, and having an integrated ink level sensor. The ink level sensor includes an ink chamber above the metal layer, a metal plate of a sense capacitor disposed in the metal layer, and a clearing resistor circuit disposed in the metal layer including four clearing resistors arranged in a surround-4 configuration about the metal plate and electrically connected in parallel between a voltage potential and ground, wherein adjacent ends of at least two clearing resistors are not directly connected to one another so as to leave a gap between the adjacent ends in the metal layer. A metal lead in the metal layer extends through the gap to the metal plate.

In a liquid ejection head, it is possible to suppress generation of a temperature distribution of liquid in a direction in which ejection openings are arranged in a print element board. Specifically, a liquid ejection head, which is provided with an ejection opening row in which a plurality of ejection openings for ejecting a liquid are arranged, includes a pressure chamber that communicates with the ejection openings and includes a pressure generation element, a passage which is provided with an opening and extends along the ejection opening row to supply the liquid flowing into the passage through the opening to the pressure chamber, a heater provided around the opening, and a temperature sensor provided in a region along the ejection opening row.

A printing head for a printing system is disclosed. The printing head comprises a plurality of compartments, each having an outlet port for depositing liquid and an inlet port separately connectable to a separate liquid container. At least two compartments are in controllable fluid communication with each other, and the printing head comprises an arrangement of sensors configured for generating signals indicative of (i) a filling state of each compartment, and (ii) a fluid communication state between the at least two compartments.

Ink is circulated through a circulation flow path between a print head and an ink tank. Detection operation for detecting an ink ejection state in an ejection opening in the print head is performed. The ink circulation and the detection operation are simultaneously performed by performing the detection operation in response to a start of the ink circulation.

A printing apparatus includes a printing unit configured to print an image on a print medium, an acquiring unit configured to acquire temperature information of the printing unit, and a control unit configured to control the printing unit so as to start relative scanning in a case where a temperature that is indicated by the temperature information has reached a print permission temperature. The print permission temperature in a first print mode whose speed at a time of a constant speed in relative scanning is a first speed is a first temperature. The print permission temperature in a second print mode whose speed at the time of the constant speed is a second speed that is faster than the first speed is a second temperature that is lower than the first temperature.

A print element substrate, comprising a plurality of heating elements, a plurality of detection elements, each configured to detect a temperature of a corresponding heating element, a first current generation unit, a second current generation unit, and a signal output unit, wherein one of the first and second current generation units supplies a current to a first detection element, the other supplies a current to a second detection element, and the signal output unit outputs a signal according to a potential difference between one terminal of the first detection element on a side where a potential variation occurs upon supply of the current and one terminal of the second detection element on a side where a potential variation occurs upon supply of the current.

A die for a printhead is described herein. The die includes a number of fluid feed holes disposed in a line parallel to a longitudinal axis of the die. A number of fluidic actuators are disposed in a line parallel to the fluid feed holes. A crack detector trace is routed between each of the plurality of fluid feed holes.

One example provides a fluidic die including a nozzle layer disposed on a substrate, the nozzle layer having an upper surface opposite the substrate and including a plurality of nozzles formed therein, each nozzle including a fluid chamber and a nozzle orifice extending through the nozzle layer from the upper surface to the fluid chamber. A conductive trace is exposed to the upper surface of the nozzle layer and extends proximate to a portion of the nozzle orifices, an impedance of the conductive trace indicative of a surface condition of the upper surface of the nozzle layer.