US 7,125,107 B2Granted

Method for driving piezoelectric ink jet head

AssigneeKYOCERA Corporation

InventorsKenichi Satake, Hisamitsu Sakai

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Abstract

The present invention is directed to a method for driving a piezoelectric ink jet head comprising a piezoelectric actuator AC that includes two piezoelectric ceramic layers 7a, 7b having such a size that covers the plurality of pressure chambers 2, wherein an electric field of opposite sense to the polarizing direction is applied to the second piezoelectric ceramic layer 7b by using the common electrodes 8a, 8b and, (1) for the pressure chambers 2 from which the ink is discharged, an electric field of the same sense as the polarizing direction of the layer is applied to the first piezoelectric ceramic layer 7a by using the individual electrode 10 and the first common electrode 8a, thereby causing the region of the piezoelectric actuator AC to deflect toward the pressure chamber 2, while (2) for the pressure chambers 2 from which the ink should not be discharged, an electric field of the opposite sense to the polarizing direction is applied to the first piezoelectric ceramic layer 7a by using the electrodes 10, 8a, thereby to maintain the region of the piezoelectric actuator AC in the initial state, so as to discharge an ink droplet selectively through the nozzle 3 that communicates with the pressure chamber 2 described in (1) and form a dot.

Claims5

Dependent claims

A method for driving a piezoelectric ink jet head that comprises a plate-shaped substrate having a plurality of recesses that would become pressure chambers to be filled with an ink being formed on one side of the substrate in the direction of substrate surface, with a nozzle that discharges the ink filling the pressure chamber as ink droplet to communicate with each recess, and a piezoelectric actuator having a first piezoelectric ceramic layer of transverse vibration mode, a first common electrode, a second piezoelectric ceramic layer of transverse vibration mode and a second common electrode, all having such a size that covers the plurality of pressure chambers, are stacked in this order from a position far from the substrate on the surface of the substrate where the recesses are formed, and having a plurality of individual electrodes formed thereon in correspondence to the pressure chambers is disposed on the first piezoelectric ceramic layer, characterized that

the piezoelectric actuator is put in the initial state by removing the electric fields applied to both of the piezoelectric ceramic layers in the period of standby, while an electric field of opposite sense to the polarizing direction is applied to the second piezoelectric ceramic layer by using the first and second common electrodes when forming a dot, and in synchronization thereof,
(1) for the pressure chambers from which ink droplet should be discharged through the nozzle, an electric field of the same sense to the polarizing direction of the layer is applied to a region of the first piezoelectric ceramic layer disposed between the individual electrode corresponding to the pressure chamber and the first common electrode by using the electrodes, thereby causing the corresponding region of the piezoelectric actuator to deflect and protrude toward the pressure chamber, while
(2) for the pressure chambers from which ink droplet should not be discharged through the nozzle, an electric field of the opposite sense to the polarizing direction of the layer is applied to a region of the first piezoelectric ceramic layer disposed between the individual electrode corresponding to the pressure chamber and the first common electrode by using the electrodes, thereby maintaining the corresponding region of the piezoelectric actuator in the initial state,
so as to discharge an ink droplet selectively through the nozzle that communicates with the pressure chamber described in (1) and form a dot.

1 more element

in the standby period, an electric field of the same sense as the polarizing direction of the layer is applied to the entire region of the first piezoelectric ceramic layer disposed between all of the individual electrodes and the first common electrode by using the electrodes, and an electric field of the opposite sense to the polarizing direction of the layer having substantially the same intensity as that applied to the first piezoelectric ceramic layer is applied to the second piezoelectric ceramic layer by using the first common electrode and the second common electrode, thereby causing the region of the piezoelectric actuator that corresponds to all the pressure chambers to deflect so as to protrude toward the pressure chamber and, when forming a dot, the electric field applied to the second piezoelectric ceramic layer is once removed and, after a predetermined period of time, the same electric field as that of the standby period is applied again and the following processes are carried out so as to discharge an ink droplet selectively through the nozzle that communicates with the pressure chamber described in (i) and form a dot:
(i) for the pressure chamber from which an ink droplet should be discharged through the nozzle, in synchronization with the removal of the electric field applied to the second piezoelectric ceramic layer, the electric field applied to a region of the first piezoelectric ceramic layer disposed between the individual electrode that corresponds to the pressure chamber and the first common electrode by means of the electrodes is also removed so as to put the region of the piezoelectric actuator in the initial state, then in synchronization with the re-application of the electric field to the second piezoelectric ceramic layer, an electric field of the same sense to the polarizing direction of the layer having an intensity about twice that of the standby period is applied to the region of the first piezoelectric ceramic layer so as to cause the region of the piezoelectric actuator to deflect and protrude toward the pressure chamber more than during the standby period and, after a predetermined period of time, intensity of the electric field applied to the region is changed to the level of standby period so as to return the region of the piezoelectric actuator to the standby state, and
(ii) for the pressure chamber from which the ink droplet should not be discharged through the nozzle, in synchronization with the removal of the electric field applied to the second piezoelectric ceramic layer, an electric field of the same sense as the polarizing direction of the layer having an intensity about twice that of standby period is applied to a region of the first piezoelectric ceramic layer disposed between the individual electrode that corresponds to the pressure chamber and the first common electrode by means of the electrodes, so as to maintain the amount of deflection of the region of the piezoelectric actuator toward the pressure chamber at the same level as that of the standby period and, thereafter, in synchronization with the re-application of the electric field to the second piezoelectric ceramic layer, intensity of the electric field applied to the region is changed to the level of the standby period so as to return the region of the piezoelectric actuator to the standby state.

Dependencies are inferred from the claim text.

Facts

Application: 10/880,364Filed 28 Jun 2004
Priority: JP 2003-18795630 Jun 2003
Published: US 2005/0024400 A13 Feb 2005
Granted: 24 Oct 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

B41J 2/04581
Control methods or devices therefor, e.g. driver circuits, control circuits: controlling heads based on piezoelectric elements
B41J 2/04588
Control methods or devices therefor, e.g. driver circuits, control circuits: using a specific waveform
B41J 2/04596
Control methods or devices therefor, e.g. driver circuits, control circuits: non-ejecting pulses
B41J
Typewriters