Ink jet head, method for manufacturing ink jet head and ink jet recorder

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of depositing a lower electrode on a first base material;
• a step of depositing a piezoelectric element containing a defective portion on the lower electrode;
• a step of depositing an upper electrode on the piezoelectric element;
• a step of applying a predetermined voltage between the upper electrode and the lower electrode so as to cause dielectric breakdown and remove, through the dielectric breakdown, a portion of the upper electrode corresponding to the defective portion of the piezoelectric element;
• and
• a step of covering a removed portion of the upper electrode by an insulator.

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of depositing a lower electrode on a first base material;
• a step of depositing a piezoelectric element containing a defective portion on the lower electrode;
• a step of depositing an upper electrode on the piezoelectric element;
• a step of applying a predetermined voltage between the upper electrode and the lower electrode so as to cause dielectric breakdown and remove, through the dielectric breakdown, a portion of the upper electrode corresponding to the defective portion of the piezoelectric element;
• an insulative layer formation step of depositing an insulative layer on the upper electrode;
• a vibration plate deposition step of depositing a vibration plate on the insulative layer;
• a step of attaching a second base material, which has been provided with a plurality of pressure chamber depressions and nozzles, to the vibration plate so that the pressure chamber depressions are covered by the vibration plate, whereby a plurality of pressure chambers are defined by the pressure chamber depressions and the vibration plate;
• a step of removing the first base material;
• and
• a step of patterning the lower electrode and the piezoelectric element so as to correspond to the plurality of pressure chambers.

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of depositing a lower electrode on a first base material;
• a step of depositing a piezoelectric element containing a defective portion on the lower electrode;
• a step of depositing an upper electrode on the piezoelectric element;
• a step of applying a predetermined voltage between the upper electrode and the lower electrode so as to cause dielectric breakdown and remove, through the dielectric breakdown, a portion of the upper electrode corresponding to the defective portion of the piezoelectric element;
• an insulative layer formation step of depositing an insulative layer on the upper electrode;
• a vibration plate deposition step of depositing a vibration plate on the insulative layer;
• a step of providing a plurality of pressure chambers and nozzles in the first base material;
• and
• a step of patterning the vibration plate so as to correspond to the plurality of pressure chambers.

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of depositing a lower electrode on a first base material;
• a step of depositing a piezoelectric element containing a defective portion on the lower electrode;
• a step of depositing an upper electrode on the piezoelectric element;
• and
• a step of applying a predetermined voltage between the upper electrode and the lower electrode so as to cause dielectric breakdown and remove, through the dielectric breakdown, a portion of the upper electrode corresponding to the defective portion of the piezoelectric element;
• wherein the predetermined voltage is a pulse voltage having a larger voltage value and a shorter application duration than a normal pulse voltage, which is applied for deforming the vibration plate for discharging ink.

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of depositing a lower electrode on a first base material;
• a step of depositing a piezoelectric element containing a defective portion on the lower electrode;
• a step of depositing a conductive vibration plate on the piezoelectric element;
• a dielectric breakdown step of applying a predetermined voltage between the conductive vibration plate and the lower electrode so as to cause dielectric breakdown and remove, through the dielectric breakdown, a portion of the conductive vibration plate corresponding to the defective portion of the piezoelectric element;
• a step of depositing an insulative layer on the conductive vibration plate;
• a step of attaching a second base material, which has been provided with a plurality of pressure chamber depressions and nozzles, to the insulative layer so that the pressure chamber depressions are covered by the insulative layer, whereby a plurality of pressure chambers are defined by the pressure chamber depressions and the insulative layer;
• a step of removing the first base material;
• and
• a step of patterning the lower electrode and the piezoelectric element so as to correspond to the plurality of pressure chambers.

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of depositing a lower electrode on a first base material;
• a step of depositing a piezoelectric element containing a defective portion on the lower electrode;
• a step of depositing a conductive vibration plate on the piezoelectric element;
• a dielectric breakdown step of applying a predetermined voltage between the conductive vibration plate and the lower electrode so as to cause dielectric breakdown and remove, through the dielectric breakdown, a portion of the conductive vibration plate corresponding to the defective portion of the piezoelectric element;
• a step of depositing an insulative layer on the conductive vibration plate;
• a step of providing a plurality of pressure chambers and nozzles in the first base material;
• and
• a step of patterning the conductive vibration plate and the insulative layer so as to correspond to the plurality of pressure chambers.

An ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, wherein:
• a first electrode and a second electrode for applying a voltage through the piezoelectric element are provided respectively on opposite sides of the piezoelectric element;
• and
• a discontinuity portion is formed through dielectric breakdown in at least one of the first and second electrodes;
• wherein an insulator is embedded in the discontinuity portion of the first or second electrode.

An ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element and a vibration plate for applying a pressure on the ink -in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, wherein:
• a first electrode and a second electrode for applying a voltage through the piezoelectric element are provided respectively on opposite sides of the piezoelectric element;
• and
• a discontinuity portion is formed through dielectric breakdown in at least one of the first and second electrodes;
• wherein the discontinuity portion of the first or second electrode is covered by an insulator.

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element, an upper electrode and a lower electrode for applying a voltage through the piezoelectric element, and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of forming a lower electrode, a piezoelectric element, and an upper electrode;
• a step of applying a predetermined voltage between the upper electrode and the lower electrode;
• a step of detecting a temperature distribution of at least one of the upper electrode and the lower electrode by using a radiation thermometer;
• and
• a step of detecting a defective portion of the piezoelectric element based on the temperature distribution, wherein:
• the temperature distribution is measured by the radiation thermometer for periodically detecting a temperature;
• and
• a plurality of pulse voltages are applied, as the predetermined voltage, at a cycle less than or equal to a detection cycle of the radiation thermometer.

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element, an upper electrode and a lower electrode for applying a voltage through the piezoelectric element, and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of forming a lower electrode, a piezoelectric element, containing a defective portion and an upper electrode;
• a step of applying a predetermined voltage between the upper electrode and the lower electrode;
• a step of detecting a temperature distribution of at least one of the upper electrode and the lower electrode by using a radiation thermometer for detecting a temperature of a plurality of elements of the upper electrode or the lower electrode, the plurality of elements each having a predetermined size;
• a step of identifying as an extreme value element, for which the detected temperature is maximum or minimum among the plurality of elements,
• a step of identifying a peak temperature portion within the extreme value element based on a temperature distribution among the plurality of elements which are adjacent to the extreme value element, and
• a step of detecting the defective portion of the piezoelectric element based on the step of identifying the peak temperature portion.

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element, an upper electrode and a lower electrode for applying a voltage through the piezoelectric element, and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of forming a lower electrode, a piezoelectric element containing a defective portion, and an upper electrode;
• a step of applying a predetermined voltage between the upper electrode and the lower electrode;
• a step of detecting a temperature distribution of at least one of the upper electrode and the lower electrode by using a radiation thermometer;
• a step of detecting the defective portion of the piezoelectric element based on the temperature distribution;
• and
• a step of removing a portion of the upper electrode or the lower electrode corresponding to a surrounding portion around the defective portion.

A method for producing an ink jet head, the ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element, an upper electrode and a lower electrode for applying a voltage through the piezoelectric element, and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, the method comprising:
• a step of forming a lower electrode, a piezoelectric element containing a deflective portion, and an upper electrode;
• a step of applying a predetermined voltage between the upper electrode and the lower electrode so as to cause dielectric breakdown;
• a step of detecting a dielectric breakdown portion in the upper electrode or the lower electrode;
• a step of identifying the defective portion of the piezoelectric portion based on the step of detecting the dielectric breakdown portion;
• and
• a step of removing a portion of the upper electrode or the lower electrode corresponding to a surrounding portion around the defective portion.

An ink jet head comprising:

• a head body which is provided with a plurality of pressure chambers containing ink and a plurality of nozzles communicated to the plurality of pressure chambers, respectively;
• and
• a plurality of actuators each having a piezoelectric element containing a defective portion thereof and a vibration plate for applying a pressure on the ink in each of the plurality of pressure chambers so as to discharge the ink through each of the nozzles, wherein:
• a first electrode and a second electrode for applying a voltage through the piezoelectric element are provided respectively on opposite sides of the piezoelectric element;
• and
• a discontinuity portion is formed in at least one of the first and second electrodes, the discontinuity portion being provided by removing a portion corresponding to a surrounding portion around the defective portion of the piezoelectric element.