Ink jetting device having metal electrodes with minimal electrical connections
AssigneeBrother Kogyo Kabushiki Kaisha
InventorQiming Zhang
Life of this patent
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Abstract
An ink jetting device includes a wall that constitutes at least a part of an ink channel and is formed of piezoelectric ceramic material polarized in one direction. A first electrode is formed wholly over one surface of the wall, a second electrode is formed partially on the other surface of the wall, and a third electrode is formed at a position that is spaced from the second electrode on the other surface of the wall. A controller is connected to the second and third electrodes but is not connected to the first electrode. The controller induces a potential difference between the second and third electrodes to deform the wall with a piezoelectric effect, so that the ink in the ink channel is pressurized to jet an ink droplet from the ink channel.
Claims26
An ink jetting device having an ink channel, comprising:
- an actuator member formed of piezoelectric ceramic material and defining at least part of the ink channel, the actuator member having a first surface and a second surface that is opposite said first surface, the piezoelectric ceramic material having a polarization direction parallel to the first surface;
- a first conductive member in contact with the first surface of the actuator member;
- a second conductive member formed partially on the second surface of the actuator member;
- a third conductive member formed partially on the second surface of the actuator member and spaced from the second conductive member so as to leave a portion of the second surface free of any conductive member;
- and
- a controller electrically connected to the second conductive member and the third conductive member, wherein the controller induces a potential difference between the second conductive member and the third conductive member producing a first electric field through a first portion of said piezoelectric ceramic material polarized in said polarization direction, said first electric field passing between a portion of the first conductive member opposed to the second conductive member and the second conductive member and said first electric field being in a direction perpendicular to said polarization direction and said first electric field produces a second electric field through a second portion of said piezoelectric ceramic material polarized in said polarization direction, said second electric field passing between a portion of the first conductive member opposed to the third conductive member and the third conductive member and said second electric field being in a direction opposite to said first electric field to deform the actuator member with a piezoelectric effect, whereby ink in the ink channel is pressurized and an ink droplet is jetted from the ink channel.
A piezoelectric ink jetting device for ejecting ink droplets, comprising:
- channel means for defining an ink channel including a deformable wall having two opposed sides and one polarization direction parallel with the deformable wall;
- a pair of spaced electrodes being disposed on one side of two opposed sides of the deformable wall and an opposing electrode being disposed on an other side of the two opposed sides of the deformable wall;
- and
- electric field inducing means for inducing a first electric field and a second electric field and inducing a potential difference between an upper area and a lower area of the deformable wall to deform the deformable wall, the electric field including means further including power means for supplying voltage to only one of the two opposed sides of the deformable wall, wherein the first electric field is produced between one electrode of said pair of spaced electrodes and the opposing electrode through said upper area of the deformable wall polarized in said one polarization direction, said first electric field being in a direction perpendicular to said one polarization direction and the second electric field is produced between an other electrode of the pair of spaced electrodes and the opposing electrode through said lower area of said deformable wall polarized in said one polarization direction, said second electric field being in a direction opposite to the first electric field.
A method of ejecting ink droplets from an ink jetting device having an ink channel defined therein by a piezoelectric wall having a polarization direction parallel to the piezoelectric wall, comprising the steps of:
- providing a first conductive member within the ink channel in contact with the piezoelectric wall;
- providing a second conductive member in contact with the piezoelectric wall on an edge of a side outside of the ink channel;
- providing a third conductive member in contact with the piezoelectric wall on the edge of a side outside of the ink channel spaced from the second conductive member;
- and
- applying voltage only to the second conductive member and grounding the third conductive member to thereby induce a potential difference between the second conductive member and the third conductive member and create opposing first electric field and second electric field in directions perpendicular to the polarization direction of the piezoelectric wall and thereby deforming the piezoelectric wall, the first electric field being formed through a first portion of the piezoelectric wall polarized in said polarization direction, said first electric field passing between the second conductive member and the first conductive member in a first direction and the second electric field being formed through a second portion of the piezoelectric wall polarized in said polarization direction, said second electric field passing between the third conductive member and the first conductive member in a second direction opposite the first direction.
Dependencies are inferred from the claim text.