An ink jet recording apparatus including: a head that ejects droplets of ink; a flow passage portion; and a temperature adjustment unit. The flow passage portion supplies the ink to the head. The flow passage portion includes, in a part thereof, a reservoir unit that reserves the ink. The temperature adjustment unit is capable of adjusting temperatures of the flow passage portion and the head independently of each other. The temperature adjustment unit controls the temperatures of the flow passage portion and the head so that the ink in the head becomes liquid from solid after ink in the flow passage portion is turned to liquid from solid.

A print head die may include a substrate, an electrical connector and at least three liquid feed slots. The electrical connector is on a first side of the substrate and extends along the major dimension of the substrate. The electrical connector is connectable directly to an electrical interconnect to connect the print head die to a controller. The at least three liquid feed slots are formed in the substrate and extend along the major dimension of the substrate. Wherein at least one and less than all of the at least three liquid feed slots has an associated temperature sensor connected to the electrical connector.

A drive signal may be determined to drive a printhead to a series of target temperatures during respective portions of a print pass by the printhead. Each of the target temperatures may be the greater of a temperature of the printhead caused by printing a quantity of printing fluid to be printed during the respective portion and a predetermined threshold temperature. A drive signal may be provided to warm the printhead to the series of target temperatures during the respective portions of the print pass.

A printing element substrate is provided that can provide an accurate temperature detection of a printing element substrate and that can suppress the printing element substrate from having a larger size. In order to realize this, sensors are arranged along the heating resistor elements arranged in the printing element substrate so that more diode sensors are arranged at a higher density in a part having a higher temperature change of the printing element substrate during the liquid ejection operation from the ejection openings.

An embodiment of this invention is directed to determining a discharge status of liquid discharged from a liquid discharge head capable of accurately determining the discharge status of each nozzle at high speed with a simple arrangement. According to the embodiment, a base includes an electrothermal transducer configured to supply heat to liquid, a first temperature detection element configured to detect the temperature of the electrothermal transducer, and a second temperature detection element configured to detect the temperature of the same electrothermal transducer. In this case, the first and the second temperature detection elements are arranged so that at least part of each of the first and second temperature detection elements is included immediately above or below a region where the electrothermal transducer is arranged in the base.

A technology capable of accurately obtaining a calibration value for calibrating a detected temperature from a temperature sensor installed in a print head is to be provided. A printing apparatus includes: a printing unit configured to perform printing onto a print medium; a supply unit configured to supply ink to the printing unit; a first detection unit configured to detect a temperature of the ink to be supplied to the printing unit; a second detection unit configured to detect a temperature of the printing unit; and an obtainment unit configured to obtain a calibration value based on a value obtained by subtracting a second detected temperature from the second detection unit from a first detected temperature from the first detection unit of the ink upstream of the printing unit, the calibration value being obtained for calibrating the second detected temperature.

A print head die may include a substrate, an electrical connector and at least three liquid feed slots. The electrical connector is on a first side of the substrate and extends along the major dimension of the substrate. The electrical connector is connectable directly to an electrical interconnect to connect the print head die to a controller. The at least three liquid feed slots are formed in the substrate and extend along the major dimension of the substrate. Wherein at least one and less than all of the at least three liquid feed slots has an associated temperature sensor connected to the electrical connector.

When the head temperature Tfinish, which is the head temperature at the time of completion of a preceding scan, is higher than the stable ejection temperature Tstable, the target temperature is made a temperature that is only a temperature value T lower than the head temperature Tfinish. On the other hand, when Tfinish, the head temperature at the time of print completion, is lower than the stable ejection temperature Tstable, the target temperature is made a temperature that is only a temperature value T higher than the head temperature Tfinish. Because of this it is possible to inhibit head temperature rise in the case where an image with a high print density is printed.

An inkjet printer configures the printheads in a printhead module in an orientation that attenuates a temperature differential between the ink drops ejected by adjacent printheads at a stitch area between the adjacent printheads. The reduced temperature differential helps ensure that the contrasts between the two inks ejected by the adjacent printheads is sufficiently similar that image quality is not adversely impacted.

A printing apparatus comprises a print head including a plurality of nozzles, a first detection unit for detecting a predetermined parameter for each nozzle, a determination unit for comparing a signal based on a detection result of the first detection unit with a threshold to determine an ink ejection status of a target nozzle, and a threshold generation unit for generating the threshold, and includes, as an operation mode, a first mode where the threshold is variable and a second mode where the threshold is fixed, wherein, in the first mode, the determination unit performs the determination for each nozzle for a predetermined number of times, the threshold generation unit changes the threshold for each time, and the threshold for the second mode is determined based on a result of the determination of the predetermined number of times.