Abstract: In order to make it less likely for the accuracy of determination of the ejection state of a liquid ejection head to be low, a liquid ejection apparatus sets a determination threshold for determining an ejection state of the liquid ejection head using first energy, the determination threshold being set based on a first output value outputted from the output unit in an event where the heat generating resistance element is driven with the first energy in an ejection state in which the liquid is ejected from an ejection port and a second output value estimated to be outputted from the output unit assuming the heat generating resistance element is driven with the first energy in a non-ejection state in which the liquid is not ejected.

Abstract: A liquid ejecting apparatus with a recording element substrate including an ejection port that ejects liquid, and a heating element that heats the liquid in order to eject the liquid from the ejection port; and at least a first temperature detecting element and a second temperature detecting element. The first temperature detecting element and the second temperature detecting element are formed at target positions centered on the center of the heating element when the recording element substrate is viewed in plan view.

Abstract: A liquid discharge head, comprising an insulating member arranged on a substrate, a resistive heating element arranged in the insulating member and configured to generate thermal energy used to discharge a liquid, a bubble chamber provided above the insulating member and configured to generate bubbles of the liquid based on the thermal energy, and a temperature detection element capable of detecting a temperature in the bubble chamber, wherein the temperature detection element is arranged between the resistive heating element and the bubble chamber and in a conductive layer closest to the bubble chamber in a plurality of conductive layers provided with respect to the insulating member.

Abstract: 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.

Abstract: 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.

Abstract: A liquid discharge head, comprising an insulating member arranged on a substrate, a resistive heating element arranged in the insulating member and configured to generate thermal energy used to discharge a liquid, a bubble chamber provided above the insulating member and configured to generate bubbles of the liquid based on the thermal energy, and a temperature detection element capable of detecting a temperature in the bubble chamber, wherein the temperature detection element is arranged between the resistive heating element and the bubble chamber and in a conductive layer closest to the bubble chamber in a plurality of conductive layers provided with respect to the insulating member.

Abstract: A print element substrate, comprising a base, a heater provided on the base and configured to generate heat used to discharge ink, a flow path member, which forms an ink flow path, configured to form, together with the base, a bubbling chamber in which the ink is bubbled by the heat of the heater provided in a bottom surface of the bubbling chamber, and a temperature sensor capable of detecting a temperature of the bubbling chamber, the temperature sensor being formed of the same material as the heater and provided in the same layer as the heater on the base.

Abstract: A printing apparatus measures a temperature of an electrothermal transducer by a corresponding temperature detection element, detects, based on the measured temperature, a peak voltage which indicates a point of change, from a state where ink is discharged normally from a printhead to a state where the ink is not discharged from the printhead, and compares the peak voltage with a threshold value. The measurement, detection, and comparison are repeated until the peal voltage becomes equal to or more than the threshold value. Energy supplied to the electrothermal transducer at a time in which the peak voltage is determined to be equal to or more than the threshold is determined to be minimum discharge energy.

Abstract: An element substrate provided in a printhead includes a heater configured to heat ink and discharge the ink from a nozzle, a temperature sensor provided in correspondence with the heater, an electric current source configured to energize the temperature sensor with an electric current based on an electric current value specified by an externally input first signal, and a determination circuit configured to determine an ink discharge status of the nozzle based on a voltage output from the temperature sensor energized with the electric current and a threshold voltage specified by an externally input second signal, and output a determination result signal.

Abstract: A printing apparatus measures a temperature of an electrothermal transducer by a corresponding temperature detection element, detects, based on the measured temperature, a peak voltage which indicates a point of change, from a state where ink is discharged normally from a printhead to a state where the ink is not discharged from the printhead, and compares the peak voltage with a threshold value. The measurement, detection, and comparison are repeated until the peal voltage becomes equal to or more than the threshold value. Energy supplied to the electrothermal transducer at a time in which the peak voltage is determined to be equal to or more than the threshold is determined to be minimum discharge energy.

Abstract: A print element substrate, comprises: a first generating unit that selects a first sensor, and in a first period and a second period that follows the first period, generates a first temperature signal; a second generating unit that selects a second sensor, and in the second period and a third period that follows the second period, generates a second temperature signal; a processing unit that receives the first and second temperature signals, and based on values of the received signals, outputs a signal indicating a discharge; and a switching unit that outputs to the processing unit the first temperature signal from the start of the second period until a predetermined timing of the second period, and at the predetermined timing, switches a signal outputted from the first temperature signal to the second temperature signal.

Abstract: According to an embodiment of this invention, an element substrate which is included in a printhead, comprises: a heater configured to heat ink and discharge ink from a nozzle; a temperature sensor provided in correspondence with the heater; an electric current source configured to energize the temperature sensor with an electric current based on an electric current value specified by an externally input first signal; and a determination circuit configured to determine an ink discharge status of the nozzle based on a voltage output from the temperature sensor energized with the electric current and a threshold voltage specified by an externally input second signal, and output a determination result signal.

Abstract: A print element substrate that includes a plurality of heaters and a plurality of temperature sensors provided in correspondence with a plurality of nozzles, comprises: a selecting unit that selects one temperature sensor from the plurality of temperature sensors and output a temperature signal; a determining unit that determines a discharge state of the nozzle based on the temperature signal output by the selecting unit; an outputting unit that, based on a determination result output from the determining unit, externally outputs a signal indicating the discharge state of the nozzle corresponding to the selected temperature sensor; and a masking unit that, in accordance with a change in selection of the temperature sensor by the selecting unit, masks the determination result output from the determining unit to the outputting unit during a predetermined time from a timing of the change.

Abstract: A print element substrate that includes a plurality of heaters and a plurality of temperature sensors provided in correspondence with a plurality of nozzles, comprises: a selecting unit that selects one temperature sensor from the plurality of temperature sensors and output a temperature signal; a determining unit that determines a discharge state of the nozzle based on the temperature signal output by the selecting unit; an outputting unit that, based on a determination result output from the determining unit, externally outputs a signal indicating the discharge state of the nozzle corresponding to the selected temperature sensor; and a masking unit that, in accordance with a change in selection of the temperature sensor by the selecting unit, masks the determination result output from the determining unit to the outputting unit during a predetermined time from a timing of the change.

Abstract: A print element substrate, comprises: a first generating unit that selects a first sensor, and in a first period and a second period that follows the first period, generates a first temperature signal; a second generating unit that selects a second sensor, and in the second period and a third period that follows the second period, generates a second temperature signal; a processing unit that receives the first and second temperature signals, and based on values of the received signals, outputs a signal indicating a discharge; and a switching unit that outputs to the processing unit the first temperature signal from the start of the second period until a predetermined timing of the second period, and at the predetermined timing, switches a signal outputted from the first temperature signal to the second temperature signal.

Abstract: A temperature rise of a head due to a printing operation with a higher speed and a higher density is suppressed. To realize this, an inkjet printing head is provided in which a plurality of printing element substrates having an ejection opening array consisting of a plurality of ejection openings for ejecting ink are arranged on a support plate in a direction of the ejection opening array. The support plate includes therein a heat pipe and a flow path through which cooling liquid is flowed.

Abstract: In order to prevent, in an operation for circulating liquid, an ejection port from sucking air or the ejection port from pushing out liquid, the subtank for temporally storing ink to be supplied to the ink jet head includes the air communication passage opened or closed by the air communication valve. The ink jet head is communicated with the subtank by the first passage and the second passage to constitute one circulation passage. In order to circulate the ink in the subtank into the common liquid chamber, the main pump is energized while the air communication valve is being closed. When the circulation operation is stopped, the air communication valve is opened immediately after the stoppage of the main pump, thereby eliminating the differential pressure between the common liquid chamber and the subtank within a short period of time.

Abstract: An ink jet recording head includes a flow passage for a liquid for cooling a recording element substrate. The flow passage is provided inside a support plate that supports the recording element substrate along a recording element array of the recording element substrate. The shortest distance between a recording element and the flow passage at the end of the support plate is larger than the shortest distance between a recording element and the flow passage in the middle of the support plate.

Abstract: An ink jet recording head includes recording element substrates each including at least one nozzle array and heat generating resistors, a common liquid chamber having introducing and discharging ports, and a supporting member mounting the recording element substrates and in which a plurality of individual liquid chambers for supplying the ink to respective recording element substrates and a plurality of ink inlet ports for supplying the ink from the common liquid chamber to respective individual liquid chambers are formed. The individual liquid chambers are arranged in a direction of flow of the ink from the ink introducing port toward the discharging port. At least in a most upstream individual liquid chamber with respect to the direction, a center line of an associated inlet port with respect to the direction is located downstream of a center line of the upstream individual liquid chamber with respect to the direction.

Abstract: There is provided an inkjet printing apparatus having a printhead equipped with printing element row that includes printing elements having a plurality of heat-producing resistance elements. The apparatus includes a temperature sensing unit which senses the temperature of the printhead, a temperature distribution storage unit in which a temperature distribution along the printing element row, a temperature gradient calculating unit which calculates the temperature gradient of the printing element row from the temperature of the printhead sensed by the temperature sensing units, a predicting unit which predicts the temperature of each printing element using the temperature gradient and the temperature distribution along the printing element row, and a control unit which applies discharge pulses, which are decided based upon the predicted temperature from the predicting unit, to each of the printing elements.