Apparatus for and a method of driving an ink jet head having an electrostatic actuator

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

• providing a marking fluid jet head having a nozzle and formed in a semiconductor substrate, 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 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 to the first electrode to the second electrode, causing the diaphragm to stabilize and to move in the opposite direction away from the first electrode to thereby eject the marking fluid from the nozzle.

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

• providing a marking fluid jet head having a nozzle and formed in a semiconductor substrate, 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 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;
• electrically coupling the first electrode to the second electrode causing the diaphragm to move in the opposite direction away from the first electrode to thereby eject the marking fluid from the nozzle;
• and
• providing a waiting period after applying the first driving voltage and before electrically coupling the first electrode to the second electrode.

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

• providing a marking fluid jet head having a nozzle formed in a semiconductor substrate, 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 charging voltage signal with a first circuit to the capacitor to cause the pathway to fill with marking fluid;
• and
• discharging the capacitor with a second circuit to thereby eject the marking fluid from the nozzle.

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

• providing a marking fluid jet head having a nozzle and formed in a semiconductor substrate, 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 charging voltage signal to the capacitor to cause the pathway to fill with marking fluid;
• discharging the capacitor to thereby eject the marking fluid from the nozzle;
• and
• providing a waiting period after applying the charging voltage and before discharging the capacitor.

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

• (a) providing a marking fluid jet head having an array of nozzles and formed in a semiconductor substrate, 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 charging voltage signal with a first circuit to at least a selected one of the capacitors to fill a respective one of the pathways with marking fluid, and
• discharging the selected ones of the capacitors charged in the previous step with a second circuit to thereby eject marking fluid droplets from the selected nozzles;
• 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 comprising
• a first circuit for applying a first driving voltage signal 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
• a second circuit for electrically coupling said first electrode to said second electrode causing said diaphragm to move in the direction away from said first electrode to thereby eject said marking fluid from said nozzle.

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 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
• electrically coupling said first electrode to said second electrode causing said diaphragm to move in the opposite direction away from said first electrode to thereby eject said marking fluid from said nozzle,
• wherein said driving circuit comprises a decoding circuit for receiving a control signal, the control signal including at least one of a charging signal and a discharging signal, and at least one of first switch means for selecting the first driving voltage to be applied to said first and second electrodes in response to the charging signal decoded by said decoding circuit and second switch means coupling said first electrode to said second electrode in response to a discharging signal decoded by said decoding circuit.

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 voltage to said electrostatic actuator to distort the diaphragm to eject ink droplets from said nozzle, said voltage application means comprising:
• charge rate control means for controlling a charge rate in charging said electrostatic actuator, and
• discharge means for discharging the charge at a discharging rate from said electrostatic actuator.

An ink jet printer comprising:

• an ink jet print head having a nozzle, an ink channel in communication with said nozzle, and an electrostatic actuator comprising of 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 voltage to said electrostatic actuator to distort said diaphragm to eject ink droplets from said nozzle, said voltage application comprising:
• charge means for charging said electrostatic actuator,
• discharge means for discharging said electrostatic actuator, and
• a charge/discharge timing control means for controlling
• (1) start and stop charging timing for said charge means, and
• (2) start and stop discharging timing for said discharge means, and said charge/discharge timing control means for stopping the discharging of said electrostatic actuator just before start of succeeding charge.

An ink jet printer control method for an ink jet printer provided with an ink jet print head having a nozzle, an ink channel in communication with the nozzle, and an electrostatic actuator comprising of a diaphragm arranged in a part of the ink channel and an electrode arranged outside of the ink channel opposite to the diaphragm, distorting the diaphragm by means of an electrostatic force generated by applying voltage to the electrostatic actuator thereby performing printing with ink droplets ejected from the nozzle, and further comprising charge rate control means for controlling charge rate in charging said electrostatic actuator, discharge means that discharges the electrostatic actuator and charge/discharge timing control means for controlling following timings;

• start and stop charging timing for the charge rate control means, and stop discharging timing for the discharge means;
• said control method comprising the steps of:
• starting the charging of the electrostatic actuator by means of said charge rate control means;
• stopping the charging of the electrostatic actuator by means of the charge rate control means;
• disabling the charge rate control means and the discharge means for a specified length of time;
• and
• discharging the electrostatic actuator by means of discharge means.

An ink jet printer control method for an ink jet printer comprising an ink jet print head having a nozzle, an ink channel in communication with the nozzle, and an electrostatic actuator comprising a diaphragm arranged in a part of the ink channel and an electrode placed outside of said ink channel opposite to the diaphragm, distorting the diaphragm by means of an electrostatic force generated by applying voltage to said electrostatic actuator thereby performing printing with ink droplets ejected from said nozzle, and further comprising charge means for charging the electrostatic actuator, discharge means for releasing the charge from the electrostatic actuator, and charge/discharge timing control means for controlling following timings;

• start and stop charging timing for the charge means, start and stop discharging timing for the discharge means;
• said control method comprising steps of:
• (a) enabling the charge means to charge the electrostatic actuator;
• (b) disabling the charge means to charge the electrostatic actuator;
• (c) enabling the discharge means to discharge the electrostatic actuator;
• (d) disabling the discharge means to discharge said electrostatic actuator;
• and
• executing step (d) before step (a).

A drive method for a printing apparatus comprising the steps of;

• providing an ink jet head having a nozzle, an ink path in communication with the nozzle, and an actuator consisting of a diaphragm provided at one part of the ink path, an first electrode provided in opposition to the diaphragm and a secondary electrode attached to a semiconductor substrate including the diaphragm,
• deforming the diaphragm by a first circuit in communication with the first and secondary electrodes, thereby filling the ink path with ink,
• repelling the diaphragm by a second circuit for electrically coupling the first and secondary electrodes, thereby ejecting ink droplets from, the nozzle to record,
• applying drive voltage with the first circuit to the secondary electrode as a positive electrode when the substrate is a p-type semiconductor substrate, and as a negative electrode when the substrate is a n-type.

An electrostatic actuator for a marking fluid head having a channel comprising:

• a first electrode;
• an insulating layer arranged on said first electrode;
• a film having a first side facing said insulating layer, a gap separating said film and said insulating layer;
• a diaphragm having a first side arranged on a second side of the said film;
• and
• a second electrode arranged between a second side of the diaphragm and a bottom wall of the channel,
• wherein when a charging signal is applied to said first and second electrodes, said diaphragm and said film are attracted to said insulating layer to fill the channel with a marking fluid, and wherein when a discharging signal is applied to said first and second electrodes, said diaphragm and said film are repelled from said insulating layer to eject the marking fluid from said marking fluid head.