LIQUID DISCHARGE HEAD AND LIQUID DISCHARGE APPARATUS USING LIQUID DISCHARGE HEAD

Abstract

In order to provide a compact and highly reliable recording head enabling precise detection of temperature information on each nozzle and rapid as well as highly accurate detection on nozzles with a discharge defect, a liquid discharge head including a liquid discharge head with a plurality of electrothermal transducing members provided on a substrate to generate heat energy for discharging liquid from a discharge port includes a temperature detecting element formed immediately under each of the plurality of electrothermal transducing members to sandwich insulating film and a temperature detecting circuit for detecting temperature information from each of the temperature detecting elements.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a recording head mounted on a recording apparatus being a first embodiment of the present invention.

FIG. 2 is a plan view of the recording head mounted on the recording apparatus being the first embodiment of the present invention.

FIG. 3 is a condition chart illustrating temperature profiles on an ink interface of cavitation-resistant film in the recording head mounted on the recording apparatus being the first embodiment of the present invention.

FIG. 4 is a condition chart illustrating temperature profiles in a temperature detecting element of the recording head mounted on the recording apparatus being the first embodiment of the present invention.

FIGS. 5A and 5B are condition charts illustrating temperature profiles as simulations on an arrangement position of a temperature detecting element.

FIG. 6 is a block diagram illustrating a schematic configuration of a heater control circuit and the temperature detecting circuit applied to the recording head illustrated in FIG. 1 and FIG. 2.

FIG. 7 is a timing chart illustrating operations of the heater control circuit illustrated in FIG. 6.

FIG. 8 is a block diagram illustrating a configuration of a circuit, to which the temperature of detecting circuit illustrated in FIG. 6, outputting a determination signal notifying non-discharge.

FIG. 9 is a plan view illustrating another shape of the temperature of detecting element used in the recording head mounted on the recording apparatus being the first embodiment of the present invention.

FIG. 10 is a plan view of a recording head mounted on a recording apparatus being a second embodiment of the present invention.

FIG. 11 is a block diagram illustrating a schematic configuration of a control circuit and a temperature detecting circuit applied to the recording head illustrated in FIG. 10.

FIG. 12 is a timing chart illustrating operations of the control circuit illustrated in FIG. 11.

FIG. 13 is a block diagram illustrating a configuration of a circuit, to which the temperature detecting circuit illustrated in FIG. 11 is applied, for outputting determination signals.

FIG. 14 is a plan view illustrating another shape of the temperature of detecting element used in the recording head mounted on the recording apparatus being the second embodiment of the present invention.

FIG. 15 is a block diagram illustrating a configuration of a circuit applied to the recording apparatus being the second embodiment of the present invention for transducing temperature information to digital values.

FIG. 16 is a perspective view illustrating major portions of a recording apparatus of a prior art.

Claims

1. A liquid discharge head comprising a plurality of electrothermal transducing members provided on a substrate to generate heat energy for discharging liquid from a discharge port, including: a temperature detecting element formed immediately under each of the plurality of electrothermal transducing members to sandwich insulating film; anda temperature detecting circuit for detecting temperature information from each of the temperature detecting elements.

2. The liquid discharge head according to claim 1, wherein the temperature detecting element is arranged above a heat accumulating layer formed on a head substrate surface.

3. The liquid discharge head according to claim 1, wherein the temperature detecting element is arranged so as to come into a stack with the electrothermal transducing member on a direction perpendicular to the head substrate surface.

4. The liquid discharge head according to claim 1, wherein the temperature detecting circuit comprises: a constant current circuit having one terminal connected to one of each of the plurality of temperature detecting elements via switching elements and the other terminal commonly connected to the other terminal of each of the plurality of temperature detecting elements; anda voltage detection circuit for detecting voltage between both terminals of a temperature detecting element brought into an on state and supplied with constant current from the constant current circuit.

5. The liquid discharge head according to claim 1, wherein the temperature detecting circuit outputs temperature information from the plurality of temperature detecting elements in a time-division basis.

6. The liquid discharge head according to claim 4, wherein the temperature detecting circuit further comprises a controlling circuit controlling on and off of the plurality of switching elements.

7. The liquid discharge head according to claim 6, wherein the temperature detecting circuit further comprises switching elements provided to each of the plurality of electrothermal transducing members, for controlling voltage supply to the electrothermal transducing members, and the controlling circuit controls on and off of the another switching element.

8. The liquid discharge head according to claim 5, wherein the temperature detecting circuit further comprises a comparison circuit outputting a determination signal in the case where a voltage value detected by the voltage detection circuit exceeds a reference voltage value.

9. The liquid discharge head according to claim 8, wherein the reference voltage value is larger than a voltage value corresponding with a maximum reach temperature to reach within a predetermined period in a normal discharge state discharging the liquid from the discharge port and not more than a voltage value corresponding with a maximum reach temperature to reach within a predetermined period in a non-discharge state not discharging the liquid from the discharge port.

10. The liquid discharge head according to claim 1, wherein the temperature detecting elements are rectangular thin film resistor members respectively.

11. The liquid discharge head according to claim 1, wherein the temperature detecting elements respectively are thin film resistor members provided with a plurality of folds to present a linear pattern.

12. A liquid discharge apparatus comprising: a liquid discharge head provided with a plurality of electrothermal transducing members on a substrate to generate heat energy for discharging liquid from a discharge port so that the liquid discharge head has a temperature detecting element immediately under each of the plurality of electrothermal transducing members to sandwich insulating film between layers and a temperature detecting circuit for detecting temperature information from each of the temperature detecting element; anda controlling portion for controlling a drive of the liquid discharge head so that the controlling portion outputs a determination signal in the case where temperature information detected by the temperature detecting circuit exceeds a reference value.

13. The liquid discharge apparatus according to claim 12, wherein the determination signal stops voltage supply to an electrothermal transducing member.

14. The liquid discharge apparatus according to claim 12, wherein the reference voltage value is larger than a voltage value corresponding with a maximum reach temperature to reach within a predetermined period in a normal discharge state discharging the liquid from the discharge port and not more than a voltage value corresponding with a maximum reach temperature to reach within a predetermined period in a non-discharge state not discharging the liquid from the discharge port.