JP4241817B2 - Inkjet printer head - Google Patents

Description

  The present invention relates to an inkjet printer head, and in particular, a land pattern for inputting a drive signal to a substantially rhomboid drive electrode of a piezoelectric sheet laminated on a cavity plate is continuously formed in an arrow shape from an acute angle portion of the drive electrode. The present invention relates to an ink jet printer head that can secure a wide area of a land pattern and reliably prevent soldering defects and can improve the mounting density of ink pressure chambers.

Conventionally, various ink jet printer heads using stacked piezoelectric actuators have been proposed.
For example, an inkjet printer head described in US Pat. No. 5,402,159 has a drive formed for each pressure chamber on a cavity plate having a plurality of nozzles and a pressure chamber for each nozzle. A plate-type piezoelectric actuator in which the piezoelectric sheets are stacked with a piezoelectric sheet sandwiched between a common electrode common to an electrode and an adjacent pressure chamber is bonded. In addition, in the ink jet print head described in Japanese Patent Publication No. 7-67803, a plurality of rhombus pressure chambers are formed in the cavity plate, and the pressure adjacent to the drive electrode formed for each pressure chamber is A plate-type piezoelectric actuator in which the piezoelectric sheets are laminated with a common electrode common to the chambers is laminated.

  However, in the piezoelectric sheet constituting the ink jet printer head described in US Pat. No. 5,402,159 and the ink jet print head described in Japanese Patent Publication No. 7-67803, In order to connect the drive electrode of the piezoelectric actuator and the power supply unit, the wiring is drawn to a position away from the drive electrode to connect to the power supply unit. In this case, the drive electrode and the power supply unit can be electrically connected, but a certain amount of space is required between the drive electrodes in order to ensure electrical insulation with the wiring to be arranged. Therefore, there is a problem that improvement in the mounting density of the pressure chamber arrangement is hindered. Further, when the land pattern is formed continuously from the drive electrode, a certain amount of space is required for the land pattern, and thus there is a problem that improvement in the mounting density of the pressure chamber arrangement is hindered.

  Therefore, the present invention has been made to solve the above-described problems, and a reliable electrical connection between the drive electrode of the piezoelectric sheet formed corresponding to the arrangement position of the ink pressure chamber and the power supply unit. An object of the present invention is to provide an ink jet printer head capable of improving the mounting density of ink pressure chambers.

In order to achieve the above object, an ink jet printer head according to a first aspect of the present invention includes a cavity plate having a plurality of substantially rhomboid ink pressure chambers having acute angle portions at both ends in a longitudinal direction in plan view, and the ink pressure chambers. A plurality of drive electrodes arranged opposite to each other, and an inkjet printer head including a piezoelectric sheet stacked on the cavity plate, wherein the plurality of ink pressure chambers are arranged corresponding to a print density A plurality of pressure chamber rows, wherein the acute angle portions of the plurality of ink pressure chambers are respectively disposed between the acute angle portions of the adjacent ink pressure chambers in another row, and the drive electrode includes the piezoelectric electrode the upper surface of the sheet, a projection in the shape of the ink pressure chamber and having an outer shape of substantially rhombic substantially similar shape to the projected shape of the ink pressure chamber Is location, the one of the acute angle portion, and the land pattern is formed continuously from the acute angle portion, the land pattern, the projection of the ink pressure chamber in a region corresponding to the acute angle portion of the ink pressure chamber Each of the ink pressure chambers of the adjacent pressure chamber row is further enlarged and formed between the projected shapes of the acute angle portions of the ink pressure chambers of the adjacent pressure chamber row. It is enlarged and formed so that it may enter between the acute angle parts of the said drive electrode corresponding to.

An ink jet printer head according to a second aspect of the present invention includes a cavity plate having a plurality of substantially rhombus-shaped ink pressure chambers having acute angle portions at both ends in the longitudinal direction in plan view, and the ink pressure chambers facing each other. An ink jet printer head having a plurality of drive electrodes to be arranged and a piezoelectric sheet laminated on the cavity plate, wherein the plurality of ink pressure chambers are arranged in accordance with a print density. Forming a chamber row, the acute angle portions of the plurality of ink pressure chambers are respectively disposed between the acute angle portions of adjacent ink pressure chambers in another row, and the drive electrode is formed on the upper surface portion of the piezoelectric sheet. in, while being disposed in the projection in the shape of the ink pressure chamber, the projection of the ink pressure chamber having two acute angle portions corresponding to the acute angle portion of the projected shape Jo to have a substantially rhombic shape of substantially similar shape, the one of the acute angle portion, and the land pattern is formed continuously from the tip of the acute angle portion, the land pattern, the ink pressure chamber in the region corresponding to the acute angle portion, is enlarged outwardly from the tip portion of the acute angle portion of the drive electrodes towards the contour of the projected shape of said ink pressure chambers, opposite the center of the drive electrode from the enlarged portion And formed so as to enter between the projected shapes of the acute angle portions of the adjacent ink pressure chambers of the other row in the direction, and further, the acute angle portion of the drive electrode corresponding to the adjacent ink pressure chamber of the other row. It is characterized by being formed so as to enter between .

An ink jet printer head according to a third aspect is the ink jet printer head according to the second aspect , wherein the land pattern is enlarged outward from the projected shape of the ink pressure chamber.

An ink jet printer head according to a fourth aspect of the invention is the ink jet printer head according to any one of the first to third aspects, wherein the piezoelectric sheet is composed of a laminate in which a plurality of piezoelectric layers are laminated. It is characterized by.

An ink jet printer head according to claim 5 is the ink jet printer head according to claim 4 , wherein the piezoelectric layer inside the laminate has substantially the same shape as the drive electrode and the land pattern, An internal electrode disposed opposite to the ink pressure chamber is formed, and a through hole is formed which is filled with a conductive material and electrically connects the drive electrode and the internal electrode. To do.

An ink jet printer head according to claim 6 is the ink jet printer head according to claim 5 , wherein the through hole is formed in the land pattern.

An ink jet printer head according to claim 7 is the ink jet printer head according to any one of claims 1 to 6 , wherein the cavity plate includes a plurality of nozzles that eject ink in the ink pressure chamber, and An ink manifold for supplying ink to the ink pressure chamber, wherein the ink pressure chamber has one acute angle portion communicating with the nozzle and the other acute angle portion communicating with the ink manifold, the other acute angle portion. The land patterns are arranged opposite to each other.

An ink jet printer head according to claim 8 is the flexible print wiring for supplying a driving voltage for applying pressure to the ink in the ink pressure chamber in the ink jet printer head according to any one of claims 1 to 7. The flexible printed wiring board and the piezoelectric sheet are electrically connected via the land pattern.

An ink jet printer head according to claim 9 is the ink jet printer head according to any one of claims 1 to 8 , wherein the piezoelectric sheet is a plurality of layers stacked over each ink pressure chamber of the cavity plate. It is characterized by comprising the following plate type piezoelectric sheet.
An ink jet printer head according to claim 10 is the ink jet printer head according to any one of claims 1 to 9, wherein the land pattern is tapered in a direction away from a center of the drive electrode. It is characterized by being.

The ink jet printer head according to claim 1 1, a cavity plate of the plurality of ink pressure chambers are formed in the surface a rectangular shape as viewed in plan, it is stacked adjacent to each other on the surface of the cavity plate a plurality of plate type piezoelectric An ink jet printer head including a sheet, wherein the plurality of ink pressure chambers have a substantially rhombus shape having two acute angle portions facing each other, and the plurality of pressure chambers arranged in a longitudinal direction of the cavity plate An acute angle portion of the plurality of ink pressure chambers is arranged so as to enter between the acute angle portions of adjacent ink pressure chambers in another row, and the plate-type piezoelectric sheet has a trapezoidal shape in plan view Alternatively, it is formed in a parallelogram shape in plan view, and the upper surface of the plate-type piezoelectric sheet is opposed to the ink pressure chamber. A plurality of drive electrodes are formed, each of which has a substantially rhombus shape that is substantially similar to the projected shape of the ink pressure chamber and is smaller than the projected shape of the ink pressure chamber on the upper surface of the piezoelectric sheet. Formed in an outer shape, a land pattern is continuously formed at one of the acute angle portions from the tip of the acute angle portion, and the land pattern is in a region corresponding to the acute angle portion of the ink pressure chamber . in outer portion than the projection shape of the ink pressure chamber, and Rutotomoni formed by expanding between the projection shape of the sharp portion of the ink pressure chamber of the pressure chamber row adjacent, away from the center of the driving electrodes And is further enlarged from the tip of the acute angle portion of the drive electrode to the outside of the projected shape of the ink pressure chamber, and the drive from the enlarged portion. Outside each acute angle portion of the drive electrode that enters between the projected shapes of the adjacent ink pressure chambers of the other row in the direction away from the center of the pole and is opposed to the adjacent ink pressure chamber of the other row It is formed so as to face the edge portion .

The ink jet printer head according to claim 1 2, in the ink jet printer head according to claim 1 1, wherein the ink pressure chamber, characterized that you have a plan view parallelogram outer shape.

The ink jet printer head according to claim 1 3, a plan view rectangular cavity plate having a plurality of ink pressure chambers having a substantially rhombic shape is formed to have an acute angle portion at both ends of the plan view longitudinal direction, and the ink pressure chamber A plurality of drive electrodes respectively disposed opposite to each other, and a piezoelectric sheet stacked on the cavity plate, wherein the plurality of ink pressure chambers correspond to a print density. A plurality of pressure chamber rows are arranged, and the acute angle portions of the plurality of ink pressure chambers are arranged so as to enter between the acute angle portions of adjacent ink pressure chambers in other rows, respectively, In the upper surface portion of the piezoelectric sheet, the projection shape of the ink pressure chamber is substantially similar to the projection shape of the ink pressure chamber, and is disposed in the projection shape of the ink pressure chamber. It has a substantially rhombus shape having two acute angle portions corresponding to the acute angle portions, and one of the acute angle portions intersects the direction away from the center in the direction away from the center of the ink pressure chamber with respect to the acute angle portion. A land pattern that is continuous from a tip portion whose direction width is narrowed and narrowed is formed, and the land pattern has a projected contour of the ink pressure chamber from the tip portion in a region corresponding to an acute angle portion of the ink pressure chamber. expanding outward toward the line, it is formed so as to enter between the ink pressure chambers other columns in a direction away from the center of the two adjacent ink pressure chambers of the sharp corners of the projected shape with respect to the distal portion Rutotomoni , is formed so as to taper in a direction away from the center of the drive electrode, further, the other column said driving electrodes corresponding to two adjacent ink pressure chambers Characterized in that it is formed so as to enter between the corners.

In the ink jet printer head according to the first aspect, the plurality of ink pressure chambers provided in the cavity plate are formed in a substantially rhombus shape having acute angle portions at both ends in the longitudinal direction in plan view. Further, the plurality of ink pressure chambers constitute a plurality of pressure chamber rows arranged corresponding to the print density, and the acute angle portions of the plurality of ink pressure chambers are adjacent to the acute angle portions of the adjacent ink pressure chambers in other rows. They are arranged with high density so as to enter each other. In addition, the piezoelectric sheet laminated on the cavity plate has a drive electrode disposed in the projected shape of the ink pressure chamber on the upper surface thereof so as to face each ink pressure chamber. Each drive electrode has a substantially rhombus-like outer shape that is substantially similar to the projected shape of the ink pressure chamber , and a land pattern is continuously formed from any one of the acute angle portions of the drive electrode. Is formed. In addition, this land pattern is a portion outside the projected shape of the ink pressure chamber in a region corresponding to the acute angle portion of the ink pressure chamber , and the projected shape of the acute angle portion of each ink pressure chamber in the adjacent pressure chamber row It is formed so as to be enlarged in between, and further enlarged so as to enter between the acute angle portions of the drive electrodes corresponding to the respective ink pressure chambers of the adjacent pressure chamber rows .
As a result, the drive electrode formed facing each ink pressure chamber is formed with a substantially rhombus-shaped outer shape within the projected shape of the ink pressure chamber, and further, at one acute angle portion of this drive electrode. The land pattern formed continuously is a portion outside the projected shape of the ink pressure chamber in a region corresponding to the acute angle portion of the ink pressure chamber , and the acute angle portion of each ink pressure chamber in the adjacent pressure chamber row Are enlarged between the projected shapes. For this reason, the land pattern can be enlarged between the projected shapes of the acute angle portions of the ink pressure chambers in the other rows in the portion where the acute angle portions of the ink pressure chambers enter between the ink pressure chambers in the other rows. Thus, a large area of the land pattern can be secured and soldering to the land pattern can be reliably performed. In addition, since the space between the sharp corners of each ink pressure chamber is effectively utilized to ensure a large land pattern area, the mounting density of the ink pressure chambers can be improved. Furthermore, since the land pattern is formed in the vicinity of the drive electrode, an increase in capacitance can be prevented.

Also, La-end pattern, it is possible to further so as to enter between the acute angle portion of the drive electrodes corresponding to the respective ink pressure chambers of adjacent pressure chamber rows expansion, to ensure a larger area of the land pattern Soldering to the land pattern can be performed reliably.
In addition, since the drive electrode is formed in a substantially rhombus outer shape similar to the ink pressure chamber, a wider area of the drive electrode is ensured in the projected shape of the ink pressure chamber to improve drive efficiency. Is possible.

In the ink jet printer head according to claim 2 , the plurality of ink pressure chambers provided in the cavity plate are formed in a substantially rhombus shape having acute angle portions at both ends in the longitudinal direction in plan view, and correspond to the printing density. A plurality of pressure chamber rows are arranged, and the acute angle portions of the plurality of ink pressure chambers are arranged at high density so as to enter between the acute angle portions of adjacent ink pressure chambers in another row, respectively. Further, the piezoelectric sheet laminated on the cavity plate has a projected shape of the ink pressure chamber having two acute angle portions corresponding to the acute angle portion of the projected shape in the projected shape of the ink pressure chamber on the upper surface portion. A substantially rhombic drive electrode having a substantially similar shape is disposed, and a land pattern is continuously formed from one end of the acute angle portion at one of the acute angle portions of the drive electrode. Further, the outer shape of the land pattern is expanded outward from the tip of the acute angle portion of the drive electrode toward the contour line of the projected shape of the ink pressure chamber in a region corresponding to the acute angle portion of the ink pressure chamber. The enlarged portion is formed so as to enter between the projected shapes of the acute angle portions of the adjacent ink pressure chambers in the other row in the direction opposite to the center of the drive electrode, and further, the adjacent ink in the other row It is formed so as to enter between the acute angle portions of the drive electrode corresponding to the pressure chamber .
As a result, the land pattern formed continuously from one acute angle portion of the substantially rhombic drive electrode formed facing each ink pressure chamber is driven in the region corresponding to the acute angle portion of the ink pressure chamber. It is expanded outward from the acute angle portion of the electrode toward the contour line of the projected shape of the ink pressure chamber, and enters between the projected shapes of the acute angle portions of the adjacent ink pressure chambers in other rows from this expanded portion. Is formed. For this reason, the outer peripheral portion of the land pattern can be brought closer to the outer edge of each acute angle portion of the drive electrode formed facing the other ink pressure chambers, and a large area of the land pattern is secured. Soldering to the land pattern can be performed reliably. In addition, since the space between the sharp corners of each ink pressure chamber is effectively utilized to ensure a large land pattern area, the mounting density of the ink pressure chambers can be improved. Furthermore, since the land pattern is formed in the vicinity of the drive electrode, an increase in capacitance can be prevented.

Also, La-end pattern, it is possible to further expand so as to enter between the acute angle portion of the drive electrodes corresponding to the ink pressure chamber adjacent the other columns, to ensure the wider area of the land pattern the Soldering to the land pattern can be performed reliably.
In addition, since the drive electrode is formed in a substantially rhombus outer shape similar to the ink pressure chamber, a wider area of the drive electrode is ensured in the projected shape of the ink pressure chamber to improve drive efficiency. Is possible.

In the ink jet printer head according to claim 3 , since the land pattern is enlarged outside the projected shape of the ink pressure chamber, the area of the land pattern can be further increased. Can be more reliably soldered.

In the ink jet printer head according to claim 4 , since the piezoelectric sheet is composed of a laminated body in which a plurality of piezoelectric layers are laminated, the piezoelectric layer is single by changing the electric field applied to each piezoelectric layer. A large deflection can be generated in the thickness direction as compared with the case of the layer. For this reason, in the piezoelectric sheet, a desired amount of ink can be ejected even if the area occupied by the portion of the piezoelectric sheet that causes the bending in the thickness direction is small, so the mounting density of the ink pressure chamber is further improved. Can be made.

In the ink jet printer head according to claim 5 , the piezoelectric layer in the multilayer body has substantially the same shape as the drive electrode and the land pattern, and an internal electrode disposed to face each ink pressure chamber is formed. Has been. The internal electrode and the drive electrode are electrically connected by a through hole filled with a conductive material.
As a result, the internal electrode and the drive electrode are electrically and reliably connected along the thickness direction by the through hole filled with the conductive material, so that a space for drawing the wiring from the internal electrode is provided between the ink pressure chambers. There is no need to provide it, and the mounting density of the ink pressure chamber can be improved. In addition, since the internal electrode and the drive electrode are electrically connected along the thickness direction by the through hole, a desired amount of ink can be obtained even if the area occupied by the portion of the laminate that causes bending in the thickness direction is small. Since the ink can be ejected, the mounting density of the ink pressure chamber can be reliably improved.

In the ink jet printer head according to claim 6 , since the internal electrode and the land pattern are electrically connected along the thickness direction by the through hole, a space for drawing the wiring from the internal electrode is provided between the ink pressure chambers. There is no need to provide it, and the mounting density of the ink pressure chamber can be improved. In addition, since the internal electrode and the land pattern are electrically connected by the through hole formed in the land pattern, the area of the drive electrode corresponding to the portion that causes the bending in the thickness direction of the stacked body is reduced. Since the hole does not decrease, it is not necessary to increase the apparent occupied area of the drive electrode by supplementing the decreased electrode area in order to discharge a desired amount of ink. Thereby, the high mounting density of the ink pressure chamber can be more reliably maintained.

  The ink pressure chamber formed on the surface of the cavity plate has a nozzle that ejects ink communicated with one acute angle portion, and an ink manifold that supplies ink to the ink pressure chamber communicated with the other acute angle portion. The land pattern is preferably disposed opposite to the other acute angle portion.

In the ink jet printer head according to the eighth aspect , the flexible printed wiring board for supplying a driving voltage for applying pressure to the ink in the ink pressure chamber is electrically connected via the land pattern of the piezoelectric sheet. Thereby, since each land pattern has a large area, soldering to the land pattern can be performed reliably. In addition, since the land pattern is formed in the vicinity of the drive electrode, an increase in capacitance can be prevented.

In the ink jet printer head according to the ninth aspect , the piezoelectric sheet is composed of a plurality of plate-type piezoelectric sheets stacked over the ink pressure chambers of the cavity plate. Thereby, since the upper surface part of a cavity plate is block | closed with a some piezoelectric sheet, the size of each piezoelectric sheet can be reduced and the dimensional accuracy after baking can be improved. Of course, since each drive electrode is also laminated with respect to the corresponding ink pressure chamber in the direction of lamination of the piezoelectric sheet on the cavity plate, the ink jet printer head can be configured while maintaining a high mounting density of the ink pressure chamber. .
In the ink jet printer head according to the tenth aspect, the land pattern is formed so as to taper in a direction away from the center of the drive electrode. Therefore, the outer peripheral portion of the land pattern is projected onto another ink pressure chamber. The outer edge of the shape can be brought closer, and a wider area of the land pattern can be secured and soldering to the land pattern can be performed more reliably.

Further, in the ink jet printer head according to claim 1 1, on the surface of a rectangular shape as viewed in plan of the cavity plate, a plurality of ink pressure chambers having a substantially rhombic shape having two acute angle portions opposing each are formed. The plurality of ink pressure chambers constitute a plurality of pressure chamber rows arranged in the longitudinal direction of the cavity plate, and the acute angle portions of the plurality of ink pressure chambers are the acute angle portions of adjacent ink pressure chambers in other rows. It is arranged with high density so as to enter between each. A plurality of plate-type piezoelectric sheets formed in a trapezoidal shape in plan view or a parallelogram shape in plan view are stacked adjacent to each other on the surface of the cavity plate. In addition, on the upper surface of the plate-type piezoelectric sheet, drive electrodes formed in a substantially rhombus outer shape that is substantially similar to the projected shape of the ink pressure chamber and smaller than the projected shape of the ink pressure chamber are respectively provided in the ink pressure chamber. Opposed to each other. In addition, a land pattern is continuously formed at the acute angle portion of any one of the drive electrodes from the tip portion of the acute angle portion. In addition, this land pattern is a portion outside the projected shape of the ink pressure chamber in a region corresponding to the acute angle portion of the ink pressure chamber , and the projected shape of the acute angle portion of each ink pressure chamber in the adjacent pressure chamber row Rutotomoni formed to expand between, are formed so as to taper in a direction away from the center of the drive electrodes, further, enlarged in the outer direction of the projection shape of the ink pressure chamber from the tip of the acute angle portion of the driving electrodes In addition, it enters between the projected shapes of the adjacent ink pressure chambers in the other row in a direction away from the center of the drive electrode from the enlarged portion, and is disposed to face the adjacent ink pressure chambers in the other row. It is formed so as to face the outer edge of each acute angle portion of the drive electrode .
Thereby, the drive electrode formed to face each ink pressure chamber is formed in a substantially rhombus outer shape in the projected shape of the ink pressure chamber, and further, the tip of one acute angle portion of this drive electrode The land pattern continuously formed in the portion is a portion outside the projected shape of the ink pressure chamber in a region corresponding to the acute angle portion of the ink pressure chamber , and of each ink pressure chamber in the adjacent pressure chamber row. It is formed to be enlarged between the projected shapes of the acute angle portion. For this reason, the land pattern can be enlarged between the projected shapes of the acute angle portions of the ink pressure chambers in the other rows in the portion where the acute angle portions of the ink pressure chambers enter between the ink pressure chambers in the other rows. Thus, a large area of the land pattern can be secured and soldering to the land pattern can be reliably performed. In addition, since the space between the sharp corners of each ink pressure chamber is effectively utilized to ensure a large land pattern area, the mounting density of the ink pressure chambers can be improved. Furthermore, since the land pattern is formed in the vicinity of the drive electrode, an increase in capacitance can be prevented. Further, since the surface portion of the cavity plate is closed with a plurality of plate-type piezoelectric sheets, the size of each plate-type piezoelectric sheet can be reduced, and the dimensional accuracy after firing can be increased. Of course, since each drive electrode is also laminated to the corresponding ink pressure chamber in the laminating direction of the plate type piezoelectric sheet on the cavity plate, an ink jet printer head can be configured while maintaining a high mounting density of the ink pressure chamber. Can do.
Further, the land pattern is expanded outward from the acute angle portion of the drive electrode toward the contour line of the projected shape of the ink pressure chamber, and the land pattern is separated from the center of the drive electrode from the enlarged portion. Are formed so as to enter between the acute angle portions of the adjacent ink pressure chambers in the row and to face the outer edge of each acute angle portion of each drive electrode. As a result, the outer peripheral portion of the land pattern can be brought closer to the outer edge of each acute angle portion of the drive electrode formed facing the other ink pressure chambers, and a wider area of the land pattern can be secured. Thus, soldering to the land pattern can be performed more reliably.
Further, since the drive electrode is formed in a shape similar to the ink pressure chamber, it is possible to secure a wider area of the drive electrode within the projected shape of the ink pressure chamber and improve the drive efficiency.
Furthermore, since the land pattern is formed so as to taper away from the center of the drive electrode, the outer peripheral portion of the land pattern can be brought closer to the outer edge of the projected shape of another ink pressure chamber. Thus, a wider area of the land pattern can be secured and soldering to the land pattern can be performed more reliably.

Further, in the ink jet printer head according to claim 1 2, the ink pressure chamber, which is formed in plan view a parallelogram external shape, also the driving electrode formed on the upper surface of the plate-type piezoelectric sheets similar shape It is formed in a parallelogram shape in plan view.
Thus, land patterns, Ru is formed continuously from the tip of one of the sharp corners in plan view a parallelogram-shaped drive electrodes which are formed opposite to each ink pressure chamber.

Further, in the ink jet printer head according to claim 1 3, a plurality of ink pressure chambers provided in the cavity plate of a rectangular shape as viewed in plan has a substantially rhombic shape having an acute angle portion at both ends of the plan view longitudinal, printing A plurality of pressure chamber rows arranged in accordance with the density are configured, and the acute angle portions of the plurality of ink pressure chambers are arranged in a high density so as to enter between the acute angle portions of adjacent ink pressure chambers in other rows, respectively. Has been. In addition, the piezoelectric sheet laminated on the cavity plate has two surfaces corresponding to the acute angle portions of the projected shape in the projected shape of the ink pressure chamber, which are substantially similar to the projected shape of the ink pressure chamber on the upper surface portion. A substantially rhombus-shaped drive electrode having an acute angle portion is disposed, and at one of the acute angle portions of the drive electrode, a direction away from the center of the ink pressure chamber with respect to the acute angle portion and a direction crossing the direction away from the center A continuous land pattern is formed from the tip portion where the width of the pattern is narrowed and narrowed. Moreover, the land pattern in a region corresponding to the acute angle portion of the ink pressure chamber, is expanded in outward direction from the portion continuous with the distal end portion to the contour line of the projection shape of the ink pressure chambers, ink with respect to the tip portion Rutotomoni formed so as to enter between the projected shape of the acute angle portions of the two adjacent ink pressure chambers in the other columns in the direction away from the center of the pressure chamber, it is formed to be tapered in a direction away from the center of the driving electrodes Further, it is formed so as to enter between the acute angle portions of the drive electrodes corresponding to the two adjacent ink pressure chambers in the other row .
Thereby, the land pattern formed continuously from one acute angle portion of the substantially rhombic drive electrode formed facing each ink pressure chamber is separated from the center of the ink pressure chamber with respect to the acute angle portion of the drive electrode. direction, the width in the direction orthogonal to the direction away from the center is continuous from thin narrow tip portion projected from a portion continuous to the front end portion of the ink pressure chamber in a region corresponding to the acute angle portion of the ink pressure chamber The shape is expanded outward toward the contour of the shape, and is formed so as to enter between the projected shapes of the acute angle portions of two adjacent ink pressure chambers in another row from the expanded portion. For this reason, the outer peripheral portion of the land pattern can be brought closer to the outer edge of each acute angle portion of the drive electrode formed facing the other ink pressure chambers, and a large area of the land pattern is secured. Soldering to the land pattern can be performed reliably. In addition, since the space between the sharp corners of each ink pressure chamber is effectively utilized to ensure a large land pattern area, the mounting density of the ink pressure chambers can be improved. Furthermore, since the land pattern is formed in the vicinity of the drive electrode, an increase in capacitance can be prevented.

Also, La-end pattern, it is possible to further expand so as to enter between the acute angle portion of the drive electrodes corresponding to two ink pressure chamber adjacent the other columns, and ensuring a wider area of the land pattern Thus, soldering to the land pattern can be performed reliably.

Further, drive dynamic electrode, which is formed in the similar shape as the ink pressure chambers to ensure a wider area of the driving electrode in the projection shape of the ink pressure chamber and it is possible to improve the driving efficiency.

Moreover, La command pattern, since it is formed so as to taper in a direction away from the center of the drive electrodes, the outer peripheral portion of the land pattern, the closer to the outer edge portion of the projection shape of the other ink pressure chambers Therefore, a wider area of the land pattern can be secured and soldering to the land pattern can be performed more reliably.

  Hereinafter, an embodiment embodying an inkjet printer head according to the present invention will be described with reference to the drawings.

  First, a schematic configuration of the ink jet printer head according to the present embodiment will be described with reference to FIGS. FIG. 1 is an exploded perspective view of an ink jet printer head according to the present embodiment. FIG. 2 is an exploded perspective view of main parts of the piezoelectric sheet and the cavity plate of the ink jet printer head according to the present embodiment. 3A and 3B are diagrams showing a schematic configuration of the ink pressure chamber and the drive electrode of the ink jet printer head according to the present embodiment, where FIG. 3A is a plan view and FIG. 3B is a longitudinal sectional view. FIG. 4 is an enlarged perspective view of a main part schematically showing the arrangement configuration of the drive electrodes formed on the piezoelectric sheet of the ink jet printer head according to the present embodiment.

  As shown in FIGS. 1 to 4, an ink jet printer head 1 has a plate type having a substantially trapezoidal shape or a substantially parallelogram shape in plan view on a cavity plate 2 having a laminated structure of thin metal plates formed in a substantially rectangular shape. The five piezoelectric sheets 20, 20, 20, 20, 20 are stacked so as to be adjacent to each other. In addition, on the surface of the cavity plate 2, a plurality of rows of ink pressure chambers 19 </ b> A formed in a substantially rhombus shape are arranged corresponding to the required printing density. The plurality of rows of ink pressure chambers 19A are arranged with high density so that the acute angle portions of the ink pressure chambers 19A can enter between the ink pressure chambers 19A of the other rows.

  The cavity plate 2 has a nine-layer structure in which nine sheets of substantially rectangular metal plates are stacked. Specifically, as shown in FIG. 3B, the cavity plate 2 includes a nozzle plate 11, a cover plate 12, a first manifold plate 13, a second manifold plate 14, a third manifold plate 15, and a supply from the lower layer. The plate 16, the aperture plate 17, the spacer plate 18, and the base plate 19 have a structure in which nine thin metal plates are laminated. Further, as shown in FIG. 1, filter holes 19B and 19B to which ink is supplied are formed at both end edges in the longitudinal direction of the cavity plate 2, and the filter holes 19B and 19B are formed in the filter holes 19B and 19B. Filters 21 and 21 in which a large number of fine through holes for preventing dust from entering are formed are stacked.

  Further, as shown in FIG. 3, the nozzle plate 11 is provided with a large number of nozzles 11A for ejecting ink having a small diameter. The cover plate 12 is provided with a large number of through-holes 12A that are passages of minute diameter ink communicating with the nozzles 11A at positions facing the nozzles 11A. One wall surface of a later-described ink manifold passage is formed.

  The first manifold plate 13 is provided with a large number of through-holes 13A, which are passages of minute diameter ink communicating with the through-holes 12A, at positions facing the through-holes 12A. A plurality of rows are formed along each row of each ink pressure chamber 19 </ b> A so that the groove-like hole portions 13 </ b> B constituting the same extend in the longitudinal direction.

  The second manifold plate 14 is provided with a large number of through-holes 14A, which are passages of minute diameter ink communicating with the through-holes 13A, at positions facing the through-holes 13A. A plurality of rows are formed along each row of each ink pressure chamber 19 </ b> A so that the groove-shaped hole portions 14 </ b> B constituting the same extend in the longitudinal direction.

  The third manifold plate 15 is provided with a large number of through-holes 15A, which are passages of minute diameter ink communicating with the through-holes 14A, at positions facing the through-holes 14A. A plurality of rows are formed along each row of each ink pressure chamber 19 </ b> A so that the groove-like hole portions 15 </ b> B constituting the same extend in the longitudinal direction.

  The supply plate 16 is provided with a large number of through-holes 16A, which are passages of minute diameter ink communicating with the through-holes 15A, at positions facing the through-holes 15A. Further, in the diagonal direction opposite to the acute angle portion of the ink pressure chamber 19A with respect to the through hole 16A of the supply plate 16, and in the vicinity of the side edge of the hole portion 15B (in FIG. 3B, A large number of through holes 16B are formed in the vicinity of the right edge) to form an ink supply passage in communication with the ink manifold passage.

  Here, as shown in FIG. 3B, the upper surface portion of the cover plate 12, the groove-shaped hole portions 13B, 14B, and 15B, and the bottom surface portion of the supply plate 16 are configured, and ink is supplied to each ink pressure chamber 19A. A plurality of ink manifold passages serving as a common ink chamber to be supplied to the ink chamber are formed in the longitudinal direction.

  The aperture plate 17 is provided with a large number of through-holes 17A that are passages of minute diameter ink communicating with the through-holes 16A. The aperture plate 17 is provided with a through hole 17B at a position below the acute angle portion on the ink supply side of each ink pressure chamber 19A, and from the lower end of the through hole 17B to the through hole 16B. Aperture portion 17C, which is a groove-like recess, is formed on the bottom surface portion up to the opposing position. The aperture portion 17C is formed in a groove having a depth of about half the thickness of the aperture plate 17.

  The spacer plate 18 is provided with a large number of through holes 18A communicating with the respective through holes 17A. The spacer plate 18 is provided with a number of through holes 18B communicating with the respective through holes 17B.

  In addition, the base plate 19 is formed with a number of approximately rhombus-shaped ink pressure chambers 19A. The through holes 18A and 18B drilled in the spacer plate 18 are arranged so as to face the acute angle portions of the ink pressure chamber 19A. The upper surface portion of each ink pressure chamber 19A is closed by each piezoelectric sheet 20, 20, 20, 20, 20 stacked on the upper side.

  On the upper surface of the piezoelectric sheet 20, drive electrodes 20 </ b> A having a substantially similar rhombus shape that is slightly smaller than the projected shape of the rhombus ink pressure chambers 19 </ b> A are formed at positions corresponding to the ink pressure chambers 19 </ b> A. ing. Further, as shown in FIG. 3A, an arrow-shaped land pattern 20B is formed continuously from the acute angle portion of the drive electrode 20A corresponding to the acute angle portion of the ink pressure chamber 19A on the ink supply side.

Next, a schematic structure of the piezoelectric sheet 20 and an electrical connection structure between the piezoelectric sheet 20 and a flexible printed wiring board (FPC) extended from a power supply circuit unit (not shown) will be described with reference to FIGS. explain. FIG. 5 is an enlarged vertical sectional view of a main part of the piezoelectric sheet 20 of the ink jet printer head 1 according to the present embodiment. FIG. 6 is an exploded perspective view schematically showing an electrical connection structure inside the piezoelectric sheet 20 of the inkjet printer head 1 according to the present embodiment.
As shown in FIGS. 5 and 6, the piezoelectric sheet 20 is formed by laminating five first piezoelectric layers 21, second piezoelectric layers 22, third piezoelectric layers 23, fourth piezoelectric layers 24, and fifth piezoelectric layers 25. It is formed in the structure.
Further, on the upper surface portion of the first piezoelectric layer 21, as described above, a substantially diamond-shaped drive electrode 20A having a substantially similar shape slightly smaller than the projected shape of the ink pressure chamber 19A and a position corresponding to each ink pressure chamber 19A is provided. An arrow-shaped land pattern 20B formed continuously from the acute angle portion of the drive electrode 20A is formed. In addition, a through hole 20C is formed in a substantially central portion of each land pattern 20B.

  The second piezoelectric layer 22 has a large number of through-holes 22A at positions facing the through-holes 20C. A common electrode 22B is formed on the upper surface of the second piezoelectric layer 22 over substantially the entire surface except for the position near the upper edge of each through hole 22A. Further, the end portion of the common electrode 22 </ b> B is formed so as to be exposed at the side surface end portion of the second piezoelectric layer 22.

  A large number of internal electrodes 23A having substantially the same shape as the drive electrodes 20A and land patterns 20B are formed on the top surface of the third piezoelectric layer 23 at positions corresponding to the drive electrodes 20A and land patterns 20B. .

  A common electrode 24A is formed on the upper surface of the fourth piezoelectric layer 24 over almost the entire surface. Further, the end portion of the common electrode 24 </ b> A is formed so as to be exposed at the side surface end portion of the fourth piezoelectric layer 24.

Further, no electrode is formed on the upper surface portion of the fifth piezoelectric layer 25.
Here, each through hole 20C of the first piezoelectric layer 21 and each through hole 22A of the second piezoelectric layer 22 communicate with each other, and each through hole 30 is formed. In each through hole 30, a conductive material (for example, , Tungsten, molybdenum, etc.). Thereby, each land pattern 20 </ b> B and each internal electrode 23 </ b> A are electrically connected via the through hole 30.

As shown in FIG. 5, a flexible printed wiring board (FPC) 32 extending from a power supply circuit unit (not shown) is disposed on the upper surface portion of the piezoelectric sheet 20. The FPC 32 includes a conductor portion 33 made of copper foil wired to a position facing each land pattern 20B, a base film 34 bonded to the upper surface portions of the conductor portions 33, and a lower surface portion of the conductor portions 33. It is comprised from the cover film 35 adhere | attached on. In addition, a large number of through-holes 35 </ b> A are formed at positions facing the land patterns 20 </ b> B of the cover film 35, that is, at the end edges of the conductor portions 33. Further, preliminary solder 36 for connecting to each land pattern 20 </ b> B is formed at a portion corresponding to each through hole 35 </ b> A of the conductor portion 33.
Therefore, by superimposing and soldering each spare solder 36 on each land pattern 20B, each conductor part 33 and land pattern 20B are joined, and each conductor part 33 and each internal part are connected through the through hole 30. The electrode 23A is electrically connected.

  Of the first to fifth piezoelectric layers 21, 22, 23, 24, and 25 configured as described above, the drive electrode 20 </ b> A of the first piezoelectric layer 21 and the internal electrode 23 </ b> A of the third piezoelectric layer 23 via the FPC 32. The first to fifth piezoelectric layers 21, 22, 23, 24, 25 are deformed by applying a driving voltage between the common electrode 22B of the second piezoelectric layer 22 and the common electrode 24A of the fourth piezoelectric layer 24. Thus, pressure can be applied to the ink in the corresponding ink pressure chamber 19 </ b> A of the cavity plate 2.

  Therefore, portions corresponding to the drive electrode 20A and the internal electrode 23A of the first to third piezoelectric layers 21, 22, and 23 constitute an active portion that bends when a voltage is applied. In addition, when the first to fifth piezoelectric layers 21, 22, 23, 24, and 25 are fired, the piezoelectric ceramic and the metal material constituting the electrode have different shrinkage rates when fired, so that the entire sheet is warped or waved. You may hit it. The fourth and fifth piezoelectric layers 24 and 25 prevent the first to fifth piezoelectric layers 21, 22, 23, 24, and 25 from being warped or undulated after firing so that their planarity is not impaired. Therefore, the active portion of the first to third piezoelectric layers 21, 22, and 23 functions as a constraining layer for deforming only in the direction of the ink pressure chamber 19A.

Next, the operation of the inkjet printer head 1 configured as described above will be described with reference to FIG.
As shown in FIG. 3, the ink supplied from the ink manifold passage constituted by the upper surface portion of the cover plate 12, the groove-shaped hole portions 13B, 14B, and 15B and the bottom surface portion of the supply plate 16 passes through the through-hole 16B. Then, the ink flows into the ink pressure chamber 19A through the aperture portion 17C, the through hole 17B, and the through hole 18B. When a driving voltage is applied between the land pattern 20B and the common electrodes 22B and 24A via the FPC 32, the piezoelectric sheet 20 is deformed to the ink pressure chamber 19A side, and the ink in the ink pressure chamber 19A is Extruded and discharged from the nozzle 11A through the through holes 18A, 17A, 16A, 15A, 14A, 13A, 12A.

  As described above in detail, in the inkjet printer head 1 of the present embodiment, the cavity plate 2 has a structure in which the plates 11 to 19 formed of nine thin metal plates are stacked. In addition, the base plate 19 is formed with a number of approximately rhombus-shaped ink pressure chambers 19A. The upper surface portion of each ink pressure chamber 19A is closed by each piezoelectric sheet 20, 20, 20, 20, 20 stacked on the upper side. The piezoelectric sheet 20 has a structure in which five first to fifth piezoelectric layers 21, 22, 23, 24, and 25 are laminated. Further, a substantially rhombic drive electrode 20A having a similar shape is formed at a position corresponding to each ink pressure chamber 19A of the first piezoelectric layer 21. The drive electrode 20A may have an acute angle portion, and a parallelogram is included in the substantially rhombus shape. An arrow-shaped land pattern 20B is formed continuously from the acute angle portion of the drive electrode 20A. A large number of internal electrodes 23A having substantially the same shape are formed at positions corresponding to the drive electrodes 20A and the land patterns 20B of the third piezoelectric layer 23. The land pattern 20B and the internal electrode 23A are electrically joined via the through hole 30 filled with a conductive material. Further, common electrodes 22B and 24A are formed on the upper surface portions of the second and fourth piezoelectric layers 22 and 24, respectively. When a driving voltage is applied to the land pattern 20B via the FPC 32, the active portion formed in the portion corresponding to the driving electrode 20A and the internal electrode 23A of the piezoelectric sheet 20 is deformed, and the inside of the ink pressure chamber 19A is deformed. Ink is ejected.

Accordingly, when the acute angle portions of each of the ink pressure chambers 19A in a plurality of rows are arranged so as to enter between the ink pressure chambers 19A in the other rows, the drive electrode 20A formed to face the one ink pressure chamber 19A. Since the arrow-shaped land pattern 20B is formed continuously from the acute angle portion, each oblique side portion of the arrow-shaped land pattern 20B is set to each acute angle of the drive electrode 20A formed to face the other ink pressure chamber 19A. Since the land pattern 20B has a large area, the solder can be reliably soldered to the land pattern 20B. In addition, since the space necessary for soldering the land pattern 20B can be easily secured by effectively utilizing the space between the acute angle portions of each ink pressure chamber 19A, the mounting density of the ink pressure chamber 19A is improved. Can be achieved. Furthermore, since the land pattern 20B is formed in the vicinity of the drive electrode 20A, an increase in electrostatic capacity can be prevented.
In the inkjet printer head 1 described in the present embodiment, the FPC 32 and the FPC 32 that are electrically connected to the power supply unit are provided outside the region where the electrodes are arranged by temporarily pulling the wiring from the drive electrode 20A or the land pattern 20B. When bonding is attempted, the wiring length to each drive electrode 20A or land pattern 20B increases and becomes longer, so that the capacitance increases unnecessarily at different sizes, resulting in poor response characteristics to ink ejection. At the same time, there arises a problem that variations occur. It is not a good idea to route the wiring for each electrode in this way, it not only adversely affects the drive characteristics of the inkjet printer head 1, but also requires a space for installation, realizing high-density mounting. It is also disadvantageous from the aspect of doing.

  In addition, since the piezoelectric sheet 20 has a structure in which five first to fifth piezoelectric layers 21, 22, 23, 24, 25 are laminated, the first to third piezoelectric layers 21, 22, 23, that is, By changing the electric field of the piezoelectric layer, which is about half of the center line in the thickness direction, a large deflection can be generated in the thickness direction. For this reason, in the piezoelectric sheet 20, a desired ink amount can be ejected even if the area occupied by the active portion that causes the bending in the thickness direction is small, so that the mounting density of the ink pressure chambers 19A is further improved. be able to. Further, by laminating the thin film first to fifth piezoelectric layers 21, 22, 23, 24, and 25, it becomes possible to increase the deformation efficiency of the piezoelectric element with respect to the unit capacitance, thereby reducing the size and cost of the driving power supply circuit. Can also be achieved.

  Further, by laminating the piezoelectric sheets 20 having a predetermined shape over the ink pressure chambers 19A of the cavity plate 2, it is possible to individually apply pressure to the ink in the ink pressure chambers 19A of the cavity plate 2. Man-hours can be reduced and manufacturing costs can be reduced. Further, since the upper surface portion of the substantially rectangular cavity plate 2 is closed by the five piezoelectric sheets 20, 20, 20, 20, 20, 20, the dimensions of each piezoelectric sheet 20 can be reduced, and the dimensional accuracy after firing Can be made highly accurate. Of course, since each drive electrode 20A is also laminated to the corresponding ink pressure chamber 19A in the direction of lamination of the piezoelectric sheet 20 on the cavity plate 2, the ink jet printer head 1 is maintained while maintaining a high mounting density of the ink pressure chamber 19A. Can be configured.

  Further, since the internal electrode 23A and the land pattern 20B are electrically connected in the thickness direction by the through hole 30, it is not necessary to provide a space for drawing the wiring from the internal electrode 23A between the ink pressure chambers 19A. The mounting density of the ink pressure chamber 19A can be improved. Further, since the internal electrode 23A and the land pattern 20B are electrically connected through the through hole 30, an unnecessary increase in capacitance can be prevented. The through hole 30 is not necessarily provided at the position of the land pattern 20B, and the drive electrode 20A and the internal electrode 23A disposed corresponding to the position of the ink pressure chamber 19A are electrically connected. It may be provided. Moreover, since only the land pattern 20B can be electrically connected to the flexible printed wiring board (FPC) 32, the influence on the deformation of the piezoelectric sheet 20 can be prevented. In particular, when the through hole 30 is provided in the land pattern 20B, the area of the drive electrode 20A that forms the active portion does not decrease due to the through hole 30, and therefore it is not necessary to compensate for this decrease and increase the apparent electrode area. . As a result, the high mounting density of the ink pressure chamber 19A is not impaired.

  Furthermore, since the through hole 30 electrically connected to the internal electrode 23A is filled with a conductive material, the internal electrode 23A and the land pattern 20B are reliably electrically connected, and a flexible printed wiring board (FPC) ) The internal electrode 23A can be reliably electrically connected to the 32 preliminary solders 36.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, in the above-described embodiment, the drive electrode 20A and the land pattern 20B are substantially formed within the projected shape of the ink pressure chamber 19A (see FIG. 5). However, as shown in FIG. The land pattern 41 having a shape may be formed on the outer side of the projected shape of the ink pressure chamber 19A and within the projected shape of the acute angle portion of each ink pressure chamber 19A. Thereby, the electrical connection between the preliminary solder portion of the FPC 32 and each land pattern 41 can be more reliably performed.
Here, FIG. 7 is an essential part enlarged perspective view schematically showing the arrangement configuration of the drive electrodes 20A formed on the piezoelectric sheet 20 of the ink jet printer head according to another embodiment. In FIG. 7, the same reference numerals as those of the ink jet printer head 1 according to the present embodiment denote the same or corresponding parts as those of the ink jet printer head 1.

It is a disassembled perspective view of the inkjet printer head which concerns on this embodiment. It is a principal part disassembled perspective view of the piezoelectric sheet and cavity plate of the inkjet printer head which concerns on this embodiment. 2A and 2B are diagrams illustrating a schematic configuration of an ink pressure chamber and drive electrodes of an ink jet printer head according to the present embodiment, in which FIG. 1A is a plan view and FIG. 1B is a longitudinal sectional view. It is a principal part expansion perspective view which shows typically the arrangement configuration of the drive electrode formed on the piezoelectric sheet of the inkjet printer head which concerns on this embodiment. It is a principal part expanded longitudinal cross-sectional view of the piezoelectric sheet of the inkjet printer head which concerns on this embodiment. It is a disassembled perspective view which shows typically the electrical connection structure inside the piezoelectric sheet of the inkjet printer head which concerns on this embodiment. It is a principal part expansion perspective view which shows typically the arrangement configuration of the drive electrode formed on the piezoelectric sheet of the inkjet printer head which concerns on other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer head 2 Cavity plate 11 Nozzle plate 12 Cover plate 13 1st manifold plate 14 2nd manifold plate 15 3rd manifold plate 16 Supply plate 17 Aperture plate 18 Spacer plate 19 Base plate 19A Ink pressure chamber 20 Piezoelectric sheet 20A Drive electrode 20B Land pattern 20C, 22A Through hole 21 First piezoelectric layer 22 Second piezoelectric layer 22B, 24A Common electrode 23 Third piezoelectric layer 23A Internal electrode 24 Fourth piezoelectric layer 25 Fifth piezoelectric layer 30 Through hole 32 FPC
33 Conductor 36 Preliminary solder

Claims (13)

A cavity plate in which a plurality of substantially rhombic ink pressure chambers having acute angle portions at both ends in the longitudinal direction in plan view are formed;
A plurality of drive electrodes respectively disposed facing the ink pressure chamber, and an inkjet printer head comprising a piezoelectric sheet laminated on the cavity plate,
The plurality of ink pressure chambers constitute a plurality of pressure chamber rows arranged corresponding to the print density, and the acute angle portions of the plurality of ink pressure chambers are adjacent to the acute angle portions of adjacent ink pressure chambers in other rows. Placed in between,
The drive electrode has a substantially rhombus outer shape substantially similar to the projected shape of the ink pressure chamber on the upper surface portion of the piezoelectric sheet, and is disposed within the projected shape of the ink pressure chamber. In the part, a land pattern is continuously formed from the acute angle part,
The land pattern is a portion outside the projected shape of the ink pressure chamber in a region corresponding to the acute angle portion of the ink pressure chamber , and the projected shape of the acute angle portion of each ink pressure chamber of the adjacent pressure chamber row It is formed so as to be enlarged in between, and further, is formed so as to be enlarged so as to enter between the acute angle portions of the drive electrodes corresponding to the respective ink pressure chambers of the adjacent pressure chamber rows. Inkjet printer head. A cavity plate in which a plurality of substantially rhombic ink pressure chambers having acute angle portions at both ends in the longitudinal direction in plan view are formed;
A plurality of drive electrodes respectively disposed facing the ink pressure chamber, and an inkjet printer head comprising a piezoelectric sheet laminated on the cavity plate,
The plurality of ink pressure chambers constitute a plurality of pressure chamber rows arranged corresponding to the print density, and the acute angle portions of the plurality of ink pressure chambers are adjacent to the acute angle portions of adjacent ink pressure chambers in other rows. Placed in between,
The drive electrode is disposed within the projected shape of the ink pressure chamber on the upper surface portion of the piezoelectric sheet, and has a projected shape of the ink pressure chamber having two acute angle portions corresponding to the acute angle portion of the projected shape. It has a substantially similar rhomboid shape, and a land pattern is formed continuously from the tip of the acute angle portion at one of the acute angle portions,
The land patterns, in a region corresponding to the acute angle portion of the ink pressure chamber is enlarged outwardly from the tip portion of the acute angle portion of the drive electrodes towards the contour of the projected shape of the ink pressure chamber, is the larger In the direction opposite to the center of the drive electrode, the adjacent ink pressure chambers are formed so as to enter between the projected shapes of the acute angle portions of the adjacent ink pressure chambers in the other row. An ink jet printer head characterized in that the ink jet printer head is formed so as to enter between the acute angle portions of the drive electrode corresponding to . The ink jet printer head according to claim 2 , wherein the land pattern is enlarged outward from a projected shape of the ink pressure chamber. The inkjet printer head according to any one of claims 1 to 3 , wherein the piezoelectric sheet is formed of a laminate in which a plurality of piezoelectric layers are laminated. The piezoelectric layer inside the multilayer body has substantially the same shape as the drive electrode and the land pattern, and an internal electrode disposed opposite to each ink pressure chamber is formed,
The ink jet printer head according to claim 4 , wherein a through hole is formed which is filled with a conductive material and electrically connects the driving electrode and the internal electrode. The ink jet printer head according to claim 5 , wherein the through hole is formed in the land pattern. The cavity plate has a plurality of nozzles that discharge ink in the ink pressure chamber, and an ink manifold that supplies ink to the ink pressure chamber,
The ink pressure chamber has one acute angle portion communicating with the nozzle, the other acute angle portion communicating with the ink manifold, and the land pattern facing the other acute angle portion. inkjet printer head according to any one of claims 1 to 6. A flexible printed wiring board for supplying a driving voltage for applying pressure to the ink in the ink pressure chamber;
Inkjet printer head according to any one of claims 1 to 7, characterized in that said flexible printed circuit board and the piezoelectric sheet is electrically connected through the land pattern. The piezoelectric sheet is an ink jet printer according to any one of claims 1 to 8, characterized in that it is composed of a plurality of plate type piezoelectric sheets which are stacked over the respective ink pressure chambers of the cavity plate head. The land patterns, ink jet printer head according to any one of claims 1 to 9, characterized in that it is formed so as to taper in a direction away from the center of the drive electrodes. A rectangular cavity plate in plan view with a plurality of ink pressure chambers formed on the surface;
An inkjet printer head comprising a plurality of plate-type piezoelectric sheets stacked adjacent to each other on the surface of the cavity plate,
The plurality of ink pressure chambers have a substantially rhombus shape having two acute angle portions opposed to each other, and constitute a plurality of pressure chamber rows arranged in the longitudinal direction of the cavity plate. Are disposed so as to enter between the acute angles of adjacent ink pressure chambers in other rows,
The plate type piezoelectric sheet is formed in a trapezoidal shape in plan view or a parallelogram shape in plan view, and a plurality of drive electrodes respectively disposed on the upper surface portion of the plate type piezoelectric sheet so as to face the ink pressure chamber. Formed,
The drive electrode is formed in a substantially rhombus outer shape substantially similar to the projected shape of the ink pressure chamber on the upper surface portion of the piezoelectric sheet and smaller than the projected shape of the ink pressure chamber. The land pattern is formed continuously from the tip of the acute angle part,
The land pattern is a portion outside the projected shape of the ink pressure chamber in a region corresponding to the acute angle portion of the ink pressure chamber , and the projected shape of the acute angle portion of each ink pressure chamber of the adjacent pressure chamber row is formed to expand during Rutotomoni, are formed so as to taper in a direction away from the center of the drive electrode, further, the outer direction of the projection shape of said ink pressure chambers from the distal end of the acute angle portion of the driving electrode Between the projected shape of the adjacent ink pressure chambers of the other row in a direction away from the center of the drive electrode from the enlarged portion, and opposed to the adjacent ink pressure chambers of the other row. An ink jet printer head characterized by being formed so as to be opposed to the outer edge of each acute angle portion of the drive electrode disposed . The ink pressure chambers, ink jet printer head according to claim 1 1, wherein that you have a plan view parallelogram outer shape. A rectangular cavity plate in plan view in which a plurality of substantially rhombus-shaped ink pressure chambers having acute angle portions at both ends in the longitudinal direction in plan view are formed;
A plurality of drive electrodes respectively disposed facing the ink pressure chamber, and an inkjet printer head comprising a piezoelectric sheet laminated on the cavity plate,
The plurality of ink pressure chambers constitute a plurality of pressure chamber rows arranged corresponding to the print density, and the acute angle portions of the plurality of ink pressure chambers are adjacent to the acute angle portions of adjacent ink pressure chambers in other rows. Placed in between,
The driving electrode is disposed in the projected shape of the ink pressure chamber in the upper surface portion of the piezoelectric sheet and is substantially similar to the projected shape of the ink pressure chamber , and two corresponding to the acute angle portion of the projected shape. It has a substantially rhombus shape having an acute angle portion, and at either one of the acute angle portions, a tip whose width in a direction crossing the direction away from the center is narrowed in a direction away from the center of the ink pressure chamber with respect to the acute angle portion. A continuous land pattern is formed from the part ,
The land patterns, in the region corresponding to the acute angle portion of the ink pressure chamber, the expanded outwardly from the tip portion toward the outline of the projected shape of the ink pressure chamber, the ink pressure chambers with respect to the distal portion center is formed so as to enter between the direction of the other columns of two adjacent ink pressure chambers of the acute angle portion of the projected shape away from Rutotomoni, are formed so as to taper in a direction away from the center of the drive electrode, Furthermore, the inkjet printer head is formed so as to enter between the acute angle portions of the drive electrode corresponding to two adjacent ink pressure chambers in the other row .

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