Abstract: There is provided a piezoelectric ceramics, including a perovskite compound of a non-stoichiometric composition represented by a composition formula (KxNa1-x)y(Nb1-zTaz)O3 (0<x?1, 0<y<1, 0?z?0.5); and a sintering aid which includes an oxide containing K, Co, and Ta.

Abstract: There is provided a piezoelectric ceramics, including a perovskite compound of a non-stoichiometric composition represented by a composition formula (KxNa1-x)y(Nb1-zTaz)O3 (0<x<1?1, 0<y<1, 0?z?0.5); and a sintering aid which includes an oxide containing K, Co, and Ta.

Abstract: A piezoelectric actuator includes piezoelectric layers. Individual electrodes are formed on an outermost piezoelectric layer and arranged in a row extending along a first direction. Through holes are formed in the outermost piezoelectric layer and arranged substantially in a row extending in the first direction to contact with first end portions of the individual electrodes. The individual electrodes include at least one first individual electrode and at least one second individual electrode. The first individual electrode comprises a first electrode terminal provided at the first end portion, and the second individual electrode comprises a second electrode terminal provided at a second end portion opposite to the first end portion with respect to a second direction perpendicular to the first direction. The second individual electrode has a thickened portion extending from the second electrode terminal towards the first end portion.

Abstract: A piezoelectric actuator includes a first ceramic sheet having individual inner-electrodes formed thereon, a second ceramic sheet having a common inner-electrode formed thereon, a third ceramic sheet having individual surface-electrodes formed thereon, and a fourth ceramic sheet having a plurality of connection electrodes connecting the individual surface-electrodes and the individual inner-electrodes respectively. The connection electrodes have first portions, second portions and third portions respectively, the first portions facing the individual surface-electrodes and arranged at a pitch in a row in a row-direction, the second portions facing the individual inner-electrodes and being arranged in the row-direction to be shifted with respect to the first portions by half the pitch respectively; and the third portions connecting the first portions and the second portions respectively.

Abstract: A piezoelectric actuator includes piezoelectric layers. Individual electrodes are formed on an outermost piezoelectric layer and arranged in a row extending along a first direction. Through holes are formed in the outermost piezoelectric layer and arranged substantially in a row extending in the first direction to contact with first end portions of the individual electrodes. The individual electrodes include at least one first individual electrode and at least one second individual electrode. The first individual electrode comprises a first electrode terminal provided at the first end portion, and the second individual electrode comprises a second electrode terminal provided at a second end portion opposite to the first end portion with respect to a second direction perpendicular to the first direction. The second individual electrode has a thickened portion extending from the second electrode terminal towards the first end portion.

Abstract: An inkjet printhead is disclosed which includes nozzles for ejecting ink droplets; a cavity unit incorporating pressure chambers; and an actuator in the form of a laminate of sheets. The actuator includes individual electrodes and a top sheet having bonding terminations. The inkjet printhead is bonded at the bonding terminations to a flexible flat cable. The bonding terminations include surface electrodes formed on the top sheet. The top sheet includes through holes, each of which is filled with a conductive material locally communicated with a corresponding one of the surface electrodes at a communication portion thereof. The top sheet includes external conductive areas, each formed on a surface of a corresponding one of the surface electrodes, and each having a thickness larger than that of the corresponding surface electrode. Each of the external conductive areas overlays an open end of the corresponding through hole located in the communication portion.

Abstract: A piezoelectric actuator includes a first ceramic sheet having an individual electrode formed thereon, a second ceramic sheet having a common electrode formed thereon, a top ceramic sheet having a surface electrode for the individual electrode and a surface electrode for the common electrode formed thereon, wherein the surface electrode for the common electrode is divided by a plurality of slits into a plurality of electrode-portions each having a area of not more than a predetermined area. Accordingly, when these ceramic sheets are calcinated to be integrated together, this construction makes it possible to lower the affect due to difference in the amount of thermal shrinkage between the surface electrode for the common electrode and the top ceramic sheet, thereby suppressing the arching deformation of the top ceramic sheet.

Abstract: A piezoelectric actuator includes individual inner-electrodes arranged between stacked ceramic sheets, individual surface-electrodes arranged in a row in a row-direction on a top surface of the stacked ceramic sheets, and connection electrodes connecting the individual inner-electrodes and the individual surface-electrodes respectively. The connection electrodes each have a size enough to cover one of the individual surface-electrodes respectively. The individual surface-electrodes and the connection electrodes are connected to each other via inner conduction electrodes filled through holes which are located at mutually different positions in a direction orthogonal to the row-direction of the individual surface-electrodes. With this, it is possible to make the contour of the piezoelectric actuator to be small, and to suppress the arching deformation or warpage of the piezoelectric actuator.

Abstract: A structure for connecting an inkjet recording head, including an actuator on which connecting terminals are disposed to apply therethrough drive voltage to respective channels formed in the head for ejecting an ink droplet onto a recording medium, to a circuit element through which control signals for controlling an operation of the head are supplied, is disclosed. The circuit element is disposed on a wiring board having bump electrodes formed thereon. The connecting terminals are superposed on and connected to the bump electrodes. Each connecting terminal comprises a surface electrode having a small thickness, and an external electrode having a large thickness and formed on the surface electrode. A part of the surface electrode has a width larger than that of the other part, and the external electrode is disposed such that a margin thereof is positioned on an inside of a periphery of the wide part.

Abstract: A piezoelectric actuator includes a first ceramic sheet having individual inner-electrodes formed thereon, a second ceramic sheet having a common inner-electrode formed thereon, a third ceramic sheet having individual surface-electrodes formed thereon, and a fourth ceramic sheet having a plurality of connection electrodes connecting the individual surface-electrodes and the individual inner-electrodes respectively. The connection electrodes have first portions, second portions and third portions respectively, the first portions facing the individual surface-electrodes and arranged at a pitch in a row in a row-direction, the second portions facing the individual inner-electrodes and being arranged in the row-direction to be shifted with respect to the first portions by half the pitch respectively; and the third portions connecting the first portions and the second portions respectively.

Abstract: A piezoelectric actuator includes a first ceramic sheet having an individual electrode formed thereon, a second ceramic sheet having a common electrode formed thereon, a top ceramic sheet having a surface electrode for the individual electrode and a surface electrode for the common electrode formed thereon, wherein the surface electrode for the common electrode is divided by a plurality of slits into a plurality of electrode-portions each having a area of not more than a predetermined area. Accordingly, when these ceramic sheets are calcinated to be integrated together, this construction makes it possible to lower the affect due to difference in the amount of thermal shrinkage between the surface electrode for the common electrode and the top ceramic sheet, thereby suppressing the arching deformation of the top ceramic sheet.

Abstract: A piezoelectric actuator includes individual inner-electrodes arranged between stacked ceramic sheets, individual surface-electrodes arranged in a row in a row-direction on a top surface of the stacked ceramic sheets, and connection electrodes connecting the individual inner-electrodes and the individual surface-electrodes respectively. The connection electrodes each have a size enough to cover one of the individual surface-electrodes respectively. The individual surface-electrodes and the connection electrodes are connected to each other via inner conduction electrodes filled through holes which are located at mutually different positions in a direction orthogonal to the row-direction of the individual surface-electrodes. With this, it is possible to make the contour of the piezoelectric actuator to be small, and to suppress the arching deformation or warpage of the piezoelectric actuator.

Abstract: An ink jet printer head includes a cavity unit and a piezoelectric actuator that is bonded to the cavity unit. The piezoelectric actuator includes a top sheet on which external pads are formed in arrays, at an appropriate pitch in each array, in a direction parallel to a direction in which nozzles are formed in arrays in the cavity unit. The external pads are electrically connected to respective individual electrodes via respective internal leads, and also to a flat cable. Each of the external pads is formed at a position right above a partition wall that separates two pressure chambers from each other in the cavity unit. Therefore, when the piezoelectric actuator is bonded to the cavity unit, the external pads of the actuator can be strongly pressed against the partition walls of the cavity unit, so that the actuator can be strongly bonded to the cavity unit and the amount of leakage of ink from the pressure chambers can be minimized.

Abstract: An ink jet print head includes a cavity plate having a plurality of nozzles and a plurality of pressure chambers communicating with the respective nozzles, and a plate-like piezoelectric actuator, in which piezoelectric sheets having a plurality of electrodes formed at positions with respect to the pressure chambers are stacked one after another. The piezoelectric actuator is bonded to the cavity plate so as to close the pressure chambers in the cavity plate. Each of the piezoelectric sheets has a thickness of between 5-40 ?m, preferably between 15-30 ?m. Surface electrodes, which electrically connect one of the electrodes, are provided at both end portions of a surface of the piezoelectric actuator, which is opposed to a surface to be bonded to the cavity plate. Protrusions having a thickness of the surface electrodes are provided between the surface electrodes on the surface of the piezoelectric actuator.

Abstract: An inkjet printhead is disclosed which includes nozzles for ejecting ink droplets; a cavity unit incorporating pressure chambers; and an actuator in the form of a laminate of sheets. The actuator includes individual electrodes and a top sheet having bonding terminations. The inkjet printhead is bonded at the bonding terminations to a flexible flat cable. The bonding terminations include surface electrodes formed on the top sheet. The top sheet includes through holes, each of which is filled with a conductive material locally communicated with a corresponding one of the surface electrodes at a communication portion thereof. The top sheet includes external conductive areas, each formed on a surface of a corresponding one of the surface electrodes, and each having a thickness larger than that of the corresponding surface electrode. Each of the external conductive areas overlays an open end of the corresponding through hole located in the communication portion.

Abstract: A structure for connecting an inkjet recording head, including an actuator on which connecting terminals are disposed to apply therethrough drive voltage to respective channels formed in the head for ejecting an ink droplet onto a recording medium, to a circuit element through which control signals for controlling an operation of the head are supplied, is disclosed. The circuit element is disposed on a wiring board having bump electrodes formed thereon. The connecting terminals are superposed on and connected to the bump electrodes. Each connecting terminal comprises a surface electrode having a small thickness, and an external electrode having a large thickness and formed on the surface electrode. A part of the surface electrode has a width larger than that of the other part, and the external electrode is disposed such that a margin thereof is positioned on an inside of a periphery of the wide part.

Abstract: An ink jet printer head includes a cavity unit and a piezoelectric actuator that is bonded to the cavity unit. The piezoelectric actuator includes a top sheet on which external pads are formed in arrays, at an appropriate pitch in each array, in a direction parallel to a direction in which nozzles are formed in arrays in the cavity unit. The external pads are electrically connected to respective individual electrodes via respective internal leads, and also to a flat cable. Each of the external pads is formed at a position right above a partition wall that separates two pressure chambers from each other in the cavity unit. Therefore, when the piezoelectric actuator is bonded to the cavity unit, the external pads of the actuator can be strongly pressed against the partition walls of the cavity unit, so that the actuator can be strongly bonded to the cavity unit and the amount of leakage of ink from the pressure chambers can be minimized.

Abstract: An ink jet print head includes a cavity plate having a plurality of nozzles and a plurality of pressure chambers communicating with the respective nozzles, and a plate-like piezoelectric actuator, in which piezoelectric sheets having a plurality of electrodes formed at positions with respect to the pressure chambers are stacked one after another. The piezoelectric actuator is bonded to the cavity plate so as to close the pressure chambers in the cavity plate. Each of the piezoelectric sheets has a thickness of between 5-40 &mgr;m, preferably between 15-30 &mgr;m. Surface electrodes, which electrically connect one of the electrodes, are provided at both end portions of a surface of the piezoelectric actuator, which is opposed to a surface to be bonded to the cavity plate. Protrusions having a thickness of the surface electrodes are provided between the surface electrodes on the surface of the piezoelectric actuator.

Abstract: An inkjet print head includes a piezoelectric actuator configured of stacked piezoelectric sheets with individual electrodes formed on the piezoelectric sheets. Positioning marks formed of the same material as the individual electrodes are formed one in each of the four corners of the piezoelectric sheets. A beam of light is radiated on the positioning marks in the stacked direction of the piezoelectric sheets, forming shadows of the positioning marks in each corner. The shadows are detected, and the center of gravity is determined for each shadow. Diagonal lines are drawn between the centers of gravity in opposing corners. The intersecting point of the diagonal lines serves as a reference point for bonding the piezoelectric actuator to the stacked cavity unit.

Abstract: A piezoelectric actuator is formed by laminating a piezoelectric sheet having individual electrodes and a piezoelectric sheet having a common electrode alternately. Through-holes are formed in the laminated piezoelectric sheets and coated with a conductive material to electrically connect the individual electrodes as well as the common electrodes in the laminating direction of the piezoelectric sheets. The maximum diameter (&phgr;) of each through-hole is not less than about 20 &mgr;m and not more than about 200 &mgr;m (20 &mgr;m≦&phgr;≦200 &mgr;m). In addition, the through-holes are provided in a staggered configuration in the laminating direction. In this arrangement, the piezoelectric actuator is less prone to warpage or waving and remains flat enough to offer high performance.