Ink jet head drive apparatus and drive method, and a printer using these

A printing apparatus comprising:

• an ink jet head having a nozzle, an ink path in communication with said nozzle, an actuator comprising a diaphragm provided at one part of said ink path and an electrode provided in opposition to said diaphragm;
• and
• drive means for deforming said diaphragm to thereby eject ink droplets from said nozzle for recording, said drive means comprising:
• a voltage applying means for applying a first voltage to said actuator to deform said diaphragm during recording, and
• a residual charge elimination means for applying to said actuator a second voltage having a polarity opposite to a polarity of the first voltage and having a magnitude of at least a voltage that causes said diaphragm to come into contact with said electrode.

An ink jet printer provided with an ink jet print head comprising:

• a nozzle;
• an ink channel in communication with said nozzle;
• an electrostatic actuator comprising a diaphragm which is provided in a part of said ink channel and an electrode arranged outside of said ink channel opposite to said diaphragm;
• and
• voltage application means for applying:
• a first voltage to said electrostatic actuator to deform diaphragm during recording, and
• a second voltage to said electrostatic actuator a second voltage having a polarity opposite to a polarity of the first voltage and having a magnitude of at least a voltage that causes said diaphragm to come into contact with said electrode.

A method for recording on a sheet comprising the steps of:

• providing a marking fluid jet head formed in a semiconductor substrate having a nozzle, a pathway in communication with the nozzle, and an actuator comprising a diaphragm provided at one part of the pathway, a first electrode provided in opposition to the diaphragm and a second electrode provided on a portion of the diaphragm, the first and second electrodes forming a capacitor;
• applying a first driving voltage signal having a first polarity to the first and second electrodes to electrostatically attract the diaphragm towards the first electrode in a first direction to fill the pathway with marking fluid;
• and
• applying a second driving voltage signal having a polarity opposite to the first polarity to the first electrode and having a magnitude of at least a voltage that causes the diaphragm to come into contact with the electrode to stabilize displacement of the diaphragm at a predetermined time.

A method for recording on a sheet comprising the steps off

• providing a marking fluid jet head formed in a semiconductor substrate having a nozzle, a pathway in communication with the nozzle and a diaphragm provided at one part of the pathway;
• forming a capacitor having a first electrode arranged on one of the semiconductor substrate and diaphragm and a second electrode disposed outside the pathway in opposition to the diaphragm with a gap arranged therebetween;
• applying a first voltage signal having first polarity, to the capacitor to cause the pathway to fill with marking fluid;
• discharging the capacitor having the first voltage applied in the previous step to thereby eject marking fluid from the nozzle, and
• applying a second voltage signal having a second polarity opposite to the first polarity to the capacitor having a magnitude of at least a voltage that causes the diaphragm to come into contact with the electrode to stabilize displacement of the diaphragm at a predetermined time.

A method for recording on a sheet comprising the steps of:

• (a) providing a marking fluid jet head formed in a semiconductor substrate having an array of nozzles, corresponding pathways in communication with respective ones of the nozzles and corresponding diaphragms provided at one part of each the pathways;
• (b) forming a plurality of capacitors, each corresponding to respective ones of the pathways, each one of the capacitors having a first electrode and a second electrode disposed on a corresponding diaphragm;
• (c) selecting at least one of the nozzles for printing a pattern by:
• applying a first voltage signal having a first polarity to charge at least a selected one of the capacitors to fill a respective one of the pathways with marking fluid, and
• discharging the capacitor charged in the previous step to thereby eject marking fluid droplets from the selected nozzle,
• applying a second voltage signal having a second polarity opposite to the first polarity to the selected ones of the capacitors charged and discharged in the previous steps having a magnitude of at least a voltage that causes the diaphragm to come into contact with the electrode to stabilizing displacement of the diaphragm at a predetermined time;
• and
• (d) repeating step (c) to print successive patterns.

A recording apparatus comprising:

• a marking fluid head comprising:
• a nozzle,
• a pathway in communication with said nozzle, and
• an actuator comprising:
• a diaphragm provided at one part of said pathway,
• a first electrode provided in opposition to said diaphragm, and
• a second electrode provided on a portion of said diaphraghm;
• and
• a driving circuit for selectively:
• applying a first driving voltage signal having a first polarity to said first and second electrodes to electrostatically attract said diaphragm towards said first electrode in a first direction to fill said pathway with marking fluid, and
• discharging the static electricity between the diaphragm and the first electrode, and causing said diaphragm to move in the opposite direction away from said first electrode to thereby eject said marking fluid from said nozzle,
• applying a second driving voltage signal having a second polarity opposite to the first polarity to said first electrode and said second electrode having a magnitude at least a voltage that causes the diaphragm to come into contact with the electrode to stabilize displacement of said diaphragm at a predetermined time.

A drive method for a printing apparatus comprising an ink jet head having a nozzle, an ink path in communication with the nozzle, an actuator consisting of a diaphragm provided at one part of the ink path and an electrode provided in opposition to the diaphragm, and a drive means which deforms the diaphragm, thereby ejecting ink droplets from the nozzle to record, said drive method comprising the steps of:

• applying a first electrical pulse having a first polarity to deform the diaphragm during a recording operation;
• and
• applying a second electrical pulse having second opposite to the first polarity to stabilize displacement of the diaphragm at a predetermined time,
• wherein a trailing edge of the second electrical pulse has a predetermined slope suppressing a displacement speed of the diaphragm to a level at which prohibits ink droplets from being ejected from the nozzle.

A printing apparatus comprising:

• an ink jet head having a nozzle, an ink path in communication with said nozzle, an actuator comprising a diaphragm provided at one part of said path and an electrode provided in opposition to said diaphragm;
• and
• drive means for deforming said diaphragm to thereby eject ink droplets from said nozzle for recording, said drive means comprising:
• a voltage applying means for applying a first electrical pulse having a first polarity to said actuator to deform the diaphragm during recording, and
• a residual charge elimination means for applying to the actuator a second electrical pulse having a second polarity opposite to the first polarity and having a trailing edge thereof having a predetermined slope for suppressing a displacement speed of said diaphragm to a level at which prohibits ink droplets from being ejected from said nozzle.

A printing apparatus comprising:

• an ink jet head having a nozzle, an ink path in communication with said nozzle, an actuator comprising a diaphragm provided at one part of said ink path and an electrode provided in opposition to said diaphragm;
• and
• drive means for deforming said diaphragm to thereby eject ink droplets from said nozzle to record, said drive means comprising a power supply voltage means for:
• applying a first electrical pulse having a first polarity to deform said diaphragm during recording operation;
• and
• applying the second electrical pulse having a second polarity opposite to the first polarity to stabilize displacement of said diaphragm at a predetermined time,
• wherein a trailing edge of the second electrical pulse has a predetermined slope for suppressing a displacement speed of the diaphragm to a level at which prohibits ink droplets from being ejected from the nozzle.

An ink jet printer provided with an ink jet print head comprising:

• a nozzle;
• an ink channel in communication with said nozzle;
• an electrostatic actuator comprising a diaphragm which is provided in a part of said ink channel and an electrode arranged outside of said ink channel opposite to said diaphragm;
• and
• voltage applying means for applying a first electrical pulse having a second polarity opposite to the first polarity and having a trailing edge thereof having a predetermined slope for suppressing a displacement speed of said diaphragm to a level at which prohibits ink droplets from being ejected from said nozzle.

A method for recording on a sheet comprising the steps of:

• providing a marking fluid jet head formed in a semiconductor substrate having a nozzle, a pathway in communication with the nozzle, and an actuator comprising a diaphragm provided at one part of the pathway, a first electrode provided in opposition to the diaphragm and a second electrode provided on a portion of the diaphragm, the first and second electrodes forming a capacitor;
• applying a first driving voltage signal having a first polarity to the first and second electrodes to electrostatically attract the diaphragm towards the first electrode in a first direction to the pathway with marking fluid;
• and
• discharging the actuator applied the first voltage in the previous step and causing the diaphragm to move in the opposite direction away from the first electrode to thereby eject the marking fluid from the nozzle,
• applying a second driving voltage signal having a second polarity opposite to the first polarity to the first and second electrodes, the second driving voltage signal being different than the first driving voltage signal,
• wherein a trailing edge of the second electrical pulse has a predetermined slope for suppressing a displacement speed of the diaphragm to a level at which prohibits ink droplets from being ejected from the nozzle.

A method for recording on a sheet comprising the steps of:

• providing a marking fluid jet head formed in a semiconductor substrate having a nozzle, a pathway in communication with the nozzle, and a diaphragm provided at one part of the pathway,
• forming a capacitor having a first electrode and a second electrode arranged on the diaphragm;
• applying a first voltage signal to the capacitor to cause the pathway to fill with marking fluid;
• and
• discharging the capacitor charged in the previous step to thereby eject the marking fluid from the nozzle,
• applying a second voltage signal to the capacitor to stabilize the capacitor, the first voltage signal being different than the second voltage signal,
• wherein a trailing edge of the second electrical signal has a predetermined slope for suppressing a displacement speed of the diaphragm to a level at which prohibits ink droplets from being ejected from the nozzle.

A method for recording on a sheet comprising the steps of:

• (a) providing a marking fluid jet head formed in a semiconductor substrate having an array of nozzles, corresponding pathways in communication with respective ones of the nozzles and corresponding diaphragm provided at one part of the pathways,
• (b) forming a plurality of capacitors each corresponding to respective ones of the pathways, each one of the capacitors having a first electrode and a second electrode disposed on a corresponding diaphragm;
• (c) selecting at least one of the nozzles for printing a pattern by:
• applying a first voltage signal to charge at least a selected one of the capacitors to fill a respective one of the pathways to fill with marking fluid, and
• discharging the capacitors charged in the previous step to thereby eject marking fluid droplets from the selected nozzles,
• applying a second voltage signal to the selected ones of the capacitors charged and discharged in the previous steps for stabilizing the selected ones of the capacitors, the first voltage signal being different than the second voltage signal,
• wherein a trailing edge of the second electrical signal has a predetermined slope for suppressing a displacement speed of the diaphragm to a level at which prohibits ink droplets from being ejected from the nozzle, and
• (d) repeating step (c) to print successive patterns.

A recording apparatus comprising:

• a marking fluid head comprising:
• a nozzle,
• a pathway in communication with said nozzle, and
• an actuator comprising:
• a diaphragm provided at one part of said pathway,
• a first electrode provided in opposition to said diaphragm, and
• a second electrode provided on a portion of said diaphragm;
• and
• a driving circuit for selectively:
• applying a first driving voltage signal having a first and second electrodes to electrostatically attract said diaphragm towards said first electrode in a first direction to fill said pathway with marking fluid, and
• discharging the static electricity between the diaphragm and the first electrode, and causing said diaphragm to move in the opposite direction away from said first electrode to thereby eject the marking fluid from said nozzle,
• applying a second driving voltage signal to said first electrode and said second electrode, the second driving voltage signal being different than the first driving voltage signal,
• wherein a trailing edge of the second electrical signal has a predetermined slope from suppressing a displacement speed of the diaphragm to a level at which prohibits ink droplets from being ejected from the nozzle.

A driving apparatus for an ink jet head having a nozzle, an ink path in communication with said nozzle, an actuator comprising a diaphragm 5 provided at one part of said ink path and an electrode provided in opposition to said diaphragm, said driving apparatus comprising:

• drive means for deforming said diaphragm to thereby eject ink droplets from said nozzle for recording, said drive means comprising:
• a voltage applying means for applying a first electrical pulse having a first polarity to said actuator to deform the diaphragm during recording, and
• a residual charge elimination means for applying to the actuator a second electrical pulse having
• (1) a first portion of an increasing voltage,
• (2) a second portion and
• (3) a third portion of a decreasing voltage for suppressing a displacement speed of said diaphragm to a level which prohibits ink droplets.

A printing apparatus comprising:

• an ink jet head having a nozzle, an ink path in communication with said nozzle, an actuator comprising a diaphragm provided at one part of said ink path and an electrode provided in opposition to said diaphragm wherein a first capacitance is formed between said diaphragm and sail electrode;
• and
• drive means for deforming said diaphragm to thereby eject ink droplets from said nozzle for recording, said drive means comprising:
• voltage applying means for applying a first electrical pulse having a first polarity to said actuator to deform said diaphragm during recording;
• first switch means for applying a first electrical pulse to said actuator to deform said diaphragm during recording;
• second switch means for applying a second electrical pulse having an opposite polarity from said first electrical pulse to said actuator when said nozzle is in a first operating state;
• a second capacitance having a value greater than the first capacitance resistance;
• and
• third switch means for applying a refreshing voltage pulse to said actuator having a trailing edge decaying at a time constant formed by the second capacitance and the resistance when said nozzle is in second operating state.

A printing apparatus comprising:

• an ink jet head having a nozzle, an ink path in communication with said nozzle, an actuator comprising a diaphragm provided at one part of said ink path and an electrode provided in opposition to said diaphragm;
• and
• drive means for deforming said diaphragm to thereby eject ink droplets from said nozzle for recording, said drive means comprising:
• voltage applying means for applying a first voltage having a first magnitude to said actuator to deform said diaphragm during recording, and
• residual charge elimination means for applying to said actuator a second voltage having a second magnitude and polarity opposite to a polarity of the first voltage and a magnitude of one of the first and second voltages being at least a voltage that causes the diaphragm to come into contact with the electrode.