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Inkjet head preventing erroneous ink ejection from unintended adjacent nozzles

Imported: 24 Feb '17 | Published: 06 Jan '04

Jun Isono, Akira Iriguchi, Atsushi Hirota

USPTO - Utility Patents

Abstract

An actuator

120 is formed from nine piezoelectric sheets stacked in this order to give a laminated configuration. A common electrode

25 is formed on the upper surface of each piezoelectric sheet

122, 121

b,

121

d,

121

f,

121

g. A plurality of drive electrodes

24 are formed the upper surface of each piezoelectric sheet

121

a,

121

c,

121

e,

123. The common electrodes

25, a cavity plate

14, and a cover plate

44 are all maintained at the same potential (

0V). The lowermost piezoelectric sheet

122 formed with the common electrode

25 is located between the cavity plate

14 and the lowermost drive electrodes

24 on the piezoelectric sheet

121

a. In this configuration, an ejection voltage applied to the drive electrodes

24 is reliably prevented from being applied to ink in a pressure chamber and/or the cavity plate

14, whereby reliable ink ejection is possible.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view showing internal configuration of an inkjet printer including inkjet printer heads according to a first embodiment of the present invention;

FIG. 2 is a perspective view showing the bottom of a head unit of the inkjet printer of FIG. 1;

FIG. 3 is an exploded perspective view showing the head unit of FIG. 2;

FIG. 4 is an exploded perspective view showing the upper portion of the head unit of FIG. 2;

FIG. 5 is a cross-sectional partial view of the head unit taken along a line V—V of FIG. 2;

FIG. 6 is an exploded perspective view showing the inkjet printer head;

FIG. 7 is an exploded perspective view showing the inkjet printer head;

FIG. 8 is an exploded perspective view showing a cavity plate of the inkjet printer head;

FIG. 9 is a magnified exploded perspective partial view showing the cavity plate of FIG. 8;

FIG. 10 is a cross-sectional view of the inkjet printer head taken along a line X of FIG. 6;

FIG. 11 is an exploded perspective view of end portion of a piezoelectric actuator of the inkjet printer head;

FIG. 12 is a cross-sectional view of the inkjet printer head;

FIG. 13 is a cross-sectional view of an inkjet printer head according to a first modification of the first embodiment;

FIG. 14 a cross-sectional view of an inkjet printer head according to a second modification of the first embodiment;

FIG. 15 is a cross-sectional view of an inkjet printer head according to a third modification of the first embodiment;

FIG. 16 is an exploded perspective view of end of a piezoelectric actuator of an inkjet printer head according to a second embodiment of the present invention;

FIG. 17 is a cross-sectional view of the inkjet printer head according to the second embodiment of the present invention; and

FIG. 18 is a cross-sectional view of one example of alternative inkjet printer heads according to the present invention.

Claims

1. An inkjet head comprising:

2. The inkjet head according to claim 1, wherein the conductive member electrically connects the common electrodes and the cavity unit to the ground.

3. The inkjet head according to claim 1, wherein plural ones of the driving electrodes located closest to the cavity plate confront the cavity unit with plural ones of the sheet members interposed therebetween.

4. The inkjet head according to claim 3, wherein the sheet members are piezoelectric ceramic sheets and include first sheet members and second sheet members, each first sheet member being provided with some of the driving electrodes on one surface, each second sheet member being provided with one of the common electrodes on one surface.

5. The inkjet head according to claim 1, wherein the conductive member is placed on the cavity unit and on a side surface of the actuator, the side surface extending in the lamination direction.

6. The inkjet head according to claim 5, wherein the conductive member is selected one of a conductive adhesive and a metal.

7. An inkjet head comprising:

8. The inkjet head according to claim 7, wherein the actuator further includes a plurality of common electrodes, and the drive electrodes and the common electrodes are positioned between the corresponding sheets in alternation with respect to a lamination direction in which the plurality of sheets are laminated, and the common electrodes are grounded.

9. The inkjet head according to claim 8, wherein the actuator has a side surface extending in the lamination direction on which the conductive member is provided, the conductive member being a selected one of a conductive adhesive and a metal, and the common electrodes are electrically connected to the conductive member.