Piezoelectric inkjet printing device with outer surface electrode layer

Abstract

A piezoelectric inkjet printing device includes a substrate and a piezoelectric plate. A pair of staggered droplet ejector rows are arranged on the substrate along the row direction. Each droplet ejector includes a nozzle connected to a pressure chamber fluid, and the pressure chamber is bounded by a side wall. The first surface of the piezoelectric plate is adjacent to the pressure chamber. An electrode layer is arranged on a second outer surface opposite the piezoelectric plate. The electrode layer includes a signal line corresponding to each droplet ejector in the staggered row, and at least one common total ground line, which is connected to a ground line aligned along the side wall above each pressure chamber. Each signal line leads to a corresponding signal input pad arranged between the staggered rows. The common total ground line extends along the row direction and leads to a return ground pad.

Description

Technical Field

[0001] The present invention belongs to the field of piezoelectric inkjet printing, and more particularly, to the structure of a piezoelectric inkjet printing device. Background Art

[0002] Inkjet printing is usually done with drop-on-demand or continuous inkjet printing. In drop-on-demand printing, droplets are ejected onto a recording medium using a droplet ejector with a booster (e.g., thermal or piezoelectric) driver. The driver is selectively activated to form and eject a flying droplet of ink that passes through the space between the print head and the recording medium and impacts the recording medium. The formation of the printed image is achieved by controlling the formation of each droplet as required to print the desired image. The desired image may include any dot pattern corresponding to the image data. It may include a graphic or text image. If appropriate ink is used, it may also include a dot pattern or a three-dimensional structure for printing a practical functional device. The ink may include a colored ink, such as cyan, magenta, yellow, or black. Alternatively, the ink may include a conductive material, a dielectric material, a magnetic material, or a semiconductor material for functional printing. The ink may also include biological, chemical, or medical materials.

[0003] During droplet ejection, the motion of the recording medium relative to the printhead can be: keeping the printhead stationary while the recording medium advances past the printhead during droplet ejection; or keeping the recording medium stationary while the printhead moves. The former motion configuration is suitable if the array of droplet ejectors on the printhead can cover the entire print area of ​​interest across the width of the recording medium. Such printheads are sometimes referred to as page width printheads. The second type of printer configuration is a carriage printer, in which the printhead droplet ejector array is smaller than the extent of the print area of ​​interest on the recording medium, and the printhead is mounted on a carriage. In a carriage printer, the recording medium advances a given distance in the direction of media advance and then stops. While the recording medium stops, the carriage carries the printhead whose nozzles are ejecting droplets in a carriage scanning direction that is substantially perpendicular to the media advance direction. After the printhead mounted on the carriage traverses the print medium while printing a strip of image, the recording medium is advanced; the direction of motion of the carriage is then reversed; the printed image is thus formed strip by strip.

[0004] The drop ejector in a drop-on-demand inkjet printhead includes a pressure chamber with an ink inlet to supply ink to the pressure chamber and a nozzle orifice for ejecting ink droplets out of the pressure chamber. In a piezoelectric inkjet printing device, one wall of the pressure chamber includes a piezoelectric element, which, when a voltage pulse is applied, causes the wall to deflect and deform into the pressure chamber filled with ink, thereby forcing the ink through the nozzle orifice. Piezoelectric inkjets have significant advantages in chemical compatibility and ink jettability with a wide variety of inks (including aqueous inks, solvent-based inks, and UV-curable inks), and the ability to eject ink droplets of different sizes by modifying the electrical pulse.

[0005] There are still technical challenges to be solved for piezoelectric inkjet printing devices. Because the amount of piezoelectric displacement per volt of voltage is small, the piezoelectric chamber wall area must be much larger than the nozzle area in order to eject a useful amount of droplets, so each droplet ejector is relatively large. The width of each droplet ejector in a row of droplet ejectors is limited by the spacing between the nozzles in that row. As a result, the length dimension of the pressure chamber is usually much larger than the width dimension. Printing applications that require high resolution and high-volume printing require a large number of droplet ejector arrays with closely arranged nozzles. By properly timing the ejection of each row of droplet ejectors, the staggered rows of nozzles can produce close-range dots on the recording medium. However, for many staggered rows, the size of the piezoelectric inkjet printing device becomes very large.

[0006] Another challenge is that, unlike thermal inkjet devices, which often include integrated logic and drive electronics to reduce the number of device pins, piezoelectric inkjet devices typically have multiple individual pins per drop ejector that need to be connected to a driver circuit board. In order to independently apply voltage to the piezoelectric element across each drop ejector to eject a drop when needed, each drop ejector needs to be connected to two electrodes. These two types of electrodes are sometimes referred to as positive and negative electrodes, or as individual and common electrodes.

[0007] Some types of piezoelectric inkjet printing devices are constructed with two types of electrodes on opposite surfaces of the piezoelectric element. In order to electrically interconnect the piezoelectric inkjet printing device to a drive circuit board, it is advantageous to arrange the two types of electrodes on the same outer surface of the piezoelectric element.

[0008] U.S. Patent No. 5,255,016 discloses a piezoelectric inkjet printing device in which positive and negative comb electrodes are formed on the outer surface of a piezoelectric plate. The teeth of the comb extend across the entire width of the drop ejector, at least in certain areas. A portion of the positive electrode extends along one edge of the piezoelectric plate, and a portion of the negative electrode extends along the opposite edge of the piezoelectric plate. Each drop ejector has a separate piezoelectric plate, which makes it difficult to manufacture large arrays of closely spaced drop ejectors.

[0009] U.S. Patent No. 6,243,114 discloses a piezoelectric inkjet printing device, wherein the common electrode on the outer surface of the piezoelectric plate is in a comb shape, one electrode tooth of which extends along each side wall of the pressure chamber, and the central common electrode tooth extends along the length of the pressure chamber. Two single electrodes extend along the length of the pressure chamber on both sides of the central common electrode tooth.

[0010] U.S. Patent No. 5,640,184 discloses a piezoelectric inkjet printing device in which pressure chambers of a row of nozzles extend alternately in opposite directions from the row of nozzles. A common electrode on the surface of a piezoelectric plate extends along the row of nozzles and has electrode teeth extending alternately in opposite directions on the side walls of the pressure chambers. Interlaced between the electrode teeth of the common electrode are spaced arrays of individual electrodes that are located directly above the pressure chambers. When a voltage is applied to the individual electrodes, the piezoelectric plate mechanically deforms in a shear mode to recess into the corresponding pressure chamber, thereby causing the ejection of ink droplets.

[0011] Chinese patent application publication No. 107344453A discloses a piezoelectric inkjet printing device, such as Figure 1 and Figure 2 shown. Figure 1 and 2 Taken from '453, reproduced for clarity in Figure 1 Some additional labels are added. The substrate 100 includes a first side 101, and a row of pressure chambers 110 are distributed on the first side 101. Each pressure chamber 110 is bounded by side walls 161 and 162. A channel 130 leads from the pressure chamber 110 to a nozzle 132 arranged on the second side 102 of the substrate 100. The width of the pressure chamber 110 between the side walls 161 and 162 is W. An ink groove 120 is fluidly connected to one end of each pressure chamber 110 to provide ink to them. A damping structure 140 including a plurality of pillars 141 is arranged in each pressure chamber 110, between the ink groove 120 and the channel 130. The drive cover plate 200 includes a piezoelectric plate 210, which can be made of, for example, lead zirconate titanate (PZT) material. The first surface 211 of the piezoelectric plate 210 is bonded to the first side 101 of the substrate 100. An electrode layer 220 is disposed on the outer second surface 212 of the piezoelectric plate 210. The electrode layer 220 includes a positive electrode 221 disposed along the length of the pressure chamber 110; and a negative electrode 222 disposed along the length of the side walls 161 and 162 between the pressure chambers 110. An ink inlet 230 passes through the piezoelectric plate 210 to introduce ink from an external ink supply source to the ink tank 120 in the substrate 100. The nozzle 132 extends outward from the flow channel 131 in the silicon material layer 310, passes through the oxide layer 320 and the nozzle layer 330 ( Figure 2 ).

[0012] Although prior art piezoelectric inkjet printing devices having two types of electrodes on the outer surface of the piezoelectric plate are disclosed, they require improvements in wiring arrangement configurations to facilitate electrical interconnection of the piezoelectric inkjet printing device. In addition, there is also a need to improve the arrangement configuration of droplet ejectors on the piezoelectric inkjet printing device in a space-saving manner to achieve high-resolution and high-throughput printing. Summary of the invention

[0013] According to one aspect of the present invention, a piezoelectric inkjet printing device includes a substrate and a piezoelectric plate. At least two rows of droplet ejectors are staggered on the substrate so that each row is aligned along the row direction. Each droplet ejector includes a pressure chamber having a width W along the row direction. The pressure chamber is disposed on a first surface of the substrate and is bounded by a first side wall and a second side wall along the row direction. Each droplet ejector also includes a nozzle, which is in fluid communication with the pressure chamber. The nozzle is disposed in a nozzle layer on a second surface of the substrate. The piezoelectric plate has a thickness of T between a first surface adjacent to the pressure chamber and an outer second surface opposite to the first surface. An electrode layer is disposed on the second surface of the piezoelectric plate. The electrode layer includes a one-to-one signal line corresponding to each droplet ejector in at least two staggered rows, and at least one common general ground line connected to each sub-ground line, each sub-ground line being disposed and aligned along the first side wall and the second side wall of each pressure chamber. Each signal line leads to a corresponding signal input pad, which is disposed between the staggered rows, wherein there is at least one pair of staggered rows. At least one common ground line extends along the row direction and leads to at least one ground return pad.

[0014] The present invention has the advantage that the wires of the piezoelectric inkjet printing device and their corresponding connection pad structure are configured to facilitate compact and reliable electrical interconnection to the printhead package. Another advantage is that the piezoelectric drop ejector is configured in a space-saving manner and can achieve high printing resolution and high printing output. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 An exploded schematic diagram showing a prior art piezoelectric droplet ejector array configuration;

[0016] Figure 2 Shows Figure 1 A cross section of a single droplet ejector of the type shown;

[0017] Figure 3 a cross section showing a portion of a piezoelectric plate and a corresponding portion of a substrate;

[0018] Figure 4A A top view of three droplet ejectors in a substrate is shown;

[0019] Figure 4B Shows the Figure 4AA top view of the wires on the piezoelectric plate corresponding to the drop ejector shown in FIG.

[0020] Figure 5 A top view of a single droplet ejector and its corresponding wires is shown;

[0021] Figure 6 A top view of a portion of a piezoelectric inkjet printing device in one embodiment is shown;

[0022] Figure 7 A top view of the masking layer with windows is shown;

[0023] Figure 8 A top view of a portion of a piezoelectric inkjet printing device in another embodiment is shown.

[0024] The purpose of the drawings should be understood to be for illustrating the concepts of the present invention and may not be drawn to scale. Wherever possible, the same reference numerals are used to designate the same features that are common to the drawings. DETAILED DESCRIPTION

[0025] The present invention includes various combinations of the embodiments described herein. References to "a particular embodiment" and the like refer to features present in at least one embodiment of the present invention. Separate references to "one embodiment" or "a particular embodiment" and the like do not necessarily refer to the same one or more embodiments; however, unless explicitly stated or obvious to one skilled in the art, these embodiments are not mutually exclusive. When referring to "a method" or "multiple methods" and similar terms, the use of the singular or plural is non-restrictive. It is specifically noted that the use of "or" in this article has no exclusive meaning unless otherwise explicitly stated or required by the context. Words such as "above...", "below...", "above..." or "below..." are intended to describe the positional relationship between features located in different planes, but it should be understood that in one device orientation, a feature of one device is located "above" another feature, and if the device is turned upside down, the feature of the device will be located "below" another feature.

[0026] Figure 3 The piezoelectric plate 210 and the corresponding portion of the substrate 100 are shown along Figure 6 The piezoelectric plate 210 has a thickness of T. The substrate 100 includes a pair of pressure chambers 111 and 112, and the pressure chambers extend outward from a central region. Each of the pressure chambers 111 and 112 includes a channel 130 leading to a nozzle 132 disposed in the nozzle layer 330. A bonding layer 270 is disposed on the first surface 211 of the piezoelectric plate 210. The bonding layer 270, for example, can be a polymer adhesive. In the assembled piezoelectric printing device 10 ( Figure 6), the bonding layer 270 bonds the piezoelectric plate 210 to the first side 101 of the substrate 100. The electrode layer 220 is disposed on the outer second surface 212 of the piezoelectric plate 210. The electrode layer 220 includes a signal line 251 on the outer second surface 212 of the piezoelectric plate 210, and the signal line 251 extends over the pressure chambers 111 and 112 in the assembled device. The signal line 251 leads to a corresponding signal input pad 255. The electrode layer 220 also includes at least one common total ground line 264.

[0027] Overlooking Figure 4A It is shown that on the substrate 100 ( Figure 3 ) are formed in a row of three droplet ejectors 150, each droplet ejector 150 including a pressure chamber 110 and a nozzle 132. The nozzles 132 (and the droplet ejectors 150) are aligned along the row direction 51, and adjacent nozzles are separated by a center spacing p. The pressure chamber 110 has a width W along the row direction 51 and is bounded by side walls 161 and 162, each of which has a wall width s, such that W+s=p. In order to provide a sufficiently large area of ​​the pressure chamber 110, it is advantageous in many embodiments for W to be greater than 0.8p. In other words, s is typically less than 0.2p. The nozzle 132 is disposed near the first end 115 of the pressure chamber 110. At Figure 4A In the example shown, ink is drawn from ink tank 120 (eg Figure 1 and Figure 2 The ink tank 120 provides ink to the plurality of pressure chambers 110. In other examples described below, the ink enters the ink inlet 121 directly from the edge of the substrate 100. The filter 146 may include a column similar to the first end 115. Figure 1 The restrictor 145 provides flow resistance (same as the filter 146), and when a drop of ink is ejected from the pressure chamber 110, the restrictor 145 helps to limit the flow of ink to the ink inlet channel 121, thereby directing more of the pressure generated by the deformation of the piezoelectric plate to push the ink drop.

[0028] Overlooking Figure 4B Shows the Figure 4A The wires are arranged on the piezoelectric plate 210 ( Figure 3 ) A portion of the electrode layer 220 on the outer second surface 212. The configuration of the wire width and spacing is to effectively drive the piezoelectric plate 210. To show the spatial relationship, the top view Figure 5A single drop ejector 150 (shown in dashed lines) disposed in the substrate 100 is shown below a corresponding wire disposed on the piezoelectric plate 210. A signal wire 251 is disposed above each corresponding pressure chamber 110 and extends in a direction 52 perpendicular to the row direction 51. Figure 5 As shown in the example, the signal line 251 is arranged above the center of the corresponding pressure chamber 110. Each signal line leads to a corresponding signal input pad 255. The nozzle 132 is close to the first end 115 of the pressure chamber 110 and is close to the signal input pad 255. Figure 4A and Figure 4B , the width b of the signal line 251 is greater than 0.1 times the width W of the pressure chamber 110. The width b of the signal line is also greater than the width W of the piezoelectric plate 210 ( Figure 3 ) is 0.2 times the thickness T of the sidewall 161. The ground line 261 is above the first sidewall 161 and the second sidewall 162 and is aligned with the sidewalls. The ground line is usually arranged on the center line between the corresponding pressure chambers 110 and extends in the direction 52 perpendicular to the row direction 51. The width of the ground line 261 is c, and in many embodiments, c is greater than the width s of the sidewalls 161 and 162. The distance d between the signal line 251 and the adjacent ground line 261 is usually greater than 0.1W. The distance d between the signal line 251 and the adjacent ground line 261 is usually greater than 0.5T and less than 2T.

[0029] Overlooking Figure 6 1 shows a portion of a piezoelectric inkjet printing device 10 according to an embodiment of the present invention. A pair of staggered rows 181 and 182 of drop ejectors 150 (similar to those described above with reference to FIG. Figure 4A , 4B and 5 described droplet ejector row) is arranged on the substrate 100 ( Figure 3 ). Each row of droplet ejectors 150 is aligned along the row direction 51. The first row 181 and the second row 182 are spaced apart from each other along a direction 52 perpendicular to the row direction 51. Each droplet ejector 150 in the first row 181 includes a pressure chamber 111, and each droplet ejector in the second row 182 includes a pressure chamber 112, and these pressure chambers are disposed on the first surface 101 of the substrate 100. Figure 6 In the example shown, ink is directly input to the ink inlet 121 of each drop ejector 150 from the edge of the substrate 100 extending along the row direction 51. The pressure chambers 111 and 112 are bounded by a first side wall 161 and a second side wall 162 along the row direction 51. Each drop ejector further includes a nozzle 132 fluidically connected to the corresponding pressure chamber 111 or 112. The nozzle 132 is disposed in the nozzle layer 330 on the second side 102 of the substrate 100. The piezoelectric plate 210 ( Figure 3) includes a signal line 251, and each droplet ejector 150 in each staggered row 181 and 182 has a corresponding signal line 251. Each signal line 251 leads to a corresponding signal input pad 255, and its pad 255 is arranged between the staggered rows 181 and 182 of the droplet ejectors 150. The electrode layer 220 also includes at least one common total ground line 264, which is connected to the ground line 261 above the first and second side walls 161 and 162 of each pressure chamber. The common total ground line 264 extends along the row direction 51 and leads to the return ground pad 265. Figure 6 For example, a common ground line 264 is disposed between the signal input pad 255 of the first staggered row 181 of the drop ejectors 150 and the signal input pad 255 of the second staggered row 182 of the drop ejectors 150. This arrangement of the signal input pad 255 and the ground return pad 265 is very advantageous in providing electrical interconnection from the piezoelectric inkjet printing device 10 to a print head package (not shown) in a compact area.

[0030] The orifices 132 in row 181 are spaced apart by a pitch p, and the orifices 132 in row 182 are also spaced apart by a pitch p. The two rows are offset along row direction 51 by a distance p / 2. As a result, if a recording medium (not shown) is moved relative to the piezoelectric inkjet printing device 10 along direction 52, a row of composite print dots with a dot pitch of p / 2 can be printed on the recording medium by properly timing the ejection of ink drops from the drop ejectors in row 181 relative to row 182. It is preferred that the piezoelectric inkjet printing device 10 have a smaller print area, i.e., the distance along direction 52 between the orifices 132 in row 181 and the orifices 132 in row 182 is relatively short. To accomplish this, drop ejectors 150 in rows 181 and 182 are oriented in opposite directions such that orifices 132 in first staggered row 181 are proximate to orifices 132 in second row 182, and such that pressure chambers 111 in first row 181 and pressure chambers 112 in second row 182 extend from their respective orifices 132 in opposite directions in direction 52. Figure 8 In the illustrated embodiment, the printing area of ​​the piezoelectric inkjet printing device 11 can be further reduced.

[0031] As if looking down Figure 7 As shown, in order to provide a more reliable, short-circuit-free electrical interconnection, an electrically insulating masking layer 280 can be set above the electrode layer 220, and the masking layer 280 includes a window 281 above the signal input pad 255 and a window 282 above the return pad 265 to expose the pads for electrical interconnection.

[0032] Figure 8 A top view of a portion of a piezoelectric inkjet printing device 10 according to another embodiment of the present invention is shown. Figure 8The configuration shown in Figure 6 Similar to that shown, except for the location of the common main ground line 264 and the return pad 265. Figure 8 In the embodiment shown, the first common general ground line 264 is disposed proximate to the second end 116 of the corresponding pressure chamber 110 in the first row 181, and the second common general ground line 266 is disposed proximate to the second end 116 of the corresponding pressure chamber 110 in the second row 182. The signal input pad 255 is disposed proximate to the first end 115 of the pressure chamber 110 in rows 181 and 182, as in the embodiment shown in FIG6. The first common general ground line 264 leads to a first return ground pad 265, and the second common general ground line 266 leads to a second return ground pad 267. The signal input pad 255 may be used as shown in FIG6. Figure 7 The same electrically insulating masking layer 280 is shown to expose the pads for electrical interconnection. In other embodiments (not shown), the return pads 265 and 267 can be further extended toward the center so that they are merged into a single return pad.

[0033] Reference above Figure 3 , 4A The drop ejector 150 and the wire arrangement described in 4B, 5, 6 and 8 are well suited for locally deflectable deformable piezoelectric plates 210, which, when a voltage pulse is applied to electrodes corresponding to the pressure chambers 110, cause the piezoelectric plates 210 to be locally deflected into one or more pressure chambers 110, thereby ejecting ink drops. For such applications, the piezoelectric plates 210 are polarized in a direction perpendicular to the first surface 211. In order for the piezoelectric plates 210 having a thickness T to be effectively deflected into the pressure chambers 110 having a width W, it is advantageous that T is less than 0.5W, and in some embodiments, T may be less than 0.3W.

[0034] In an exemplary embodiment, the pitch p of each row is 0.01 inches, so that the nozzles 132 in each row are arranged at 100 nozzles per inch, and the two rows of drop ejectors can print a composite dot row of 200 dots per inch. For the pitch p = 0.01 inches = 254 microns, the pressure chamber width W can be 224 microns, and the sidewall width s can be 30 microns, so as mentioned above Figure 4A As mentioned above, s is less than 0.2p. The piezoelectric plate 210 itself is about 50 microns thick, which is beneficial for it to be less fragile. In such an example, from Figure 4A and 4BIt can be seen that the nozzle pitch p is equal to the width b of the signal line 251 plus the width c of the ground line 261 plus twice the distance d between the signal line 251 and the ground line 261, that is, p=b+c+2d. In one example, the width b of the signal line 251 is 90 microns, the width c of the ground line 261 is 90 microns, and the distance d is 37 microns. In the example where W=224 microns and d=37 microns, the distance d between the signal line 251 and the adjacent ground line 261 is greater than 0.1W. In addition, in this example, the width b of the signal line 251 is greater than 0.1W. In addition, for the piezoelectric plate 210 with a thickness T of 50 microns, the distance d=37 microns between the signal line 251 and the adjacent ground line 261 is greater than 0.5T and less than 2T, and the width b of the signal line 251 is greater than 0.2T.

[0035] In the above-described embodiment, there is only a single pair of staggered rows 181 and 182 of drop ejectors 150. In other embodiments (not shown), there may be more pairs of staggered rows of drop ejectors to provide higher print resolution or increased ink coverage, or each pair of staggered rows may be used to eject different types of ink (e.g., different colors of ink), or each pair of staggered rows may be used to eject ink drops of a different size range.

[0036] The invention has been described in detail herein with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications are encompassed within the spirit and scope of the invention.

Claims

1. A piezoelectric inkjet printing device, characterized in that: include: A base plate comprising: a first side; and a second side opposite to the first side; and At least one pair of staggered droplet ejector rows are disposed on the substrate, each row being arranged along a row direction, each droplet ejector comprising: A pressure chamber is provided on the first surface of the substrate and has a width W in the row direction, and the pressure chamber is bounded by a first side wall and a second side wall; and A nozzle hole is in fluid communication with the pressure chamber, and the nozzle hole is disposed in the nozzle hole layer on the second surface of the substrate; a piezoelectric plate having a thickness T between a first surface proximate to the pressure chamber and an outer second surface opposite to the first surface; An electrode layer is disposed on the second surface of the piezoelectric plate, wherein the electrode layer comprises: a signal line corresponding to each drop ejector in at least one pair of staggered drop ejector rows, each signal line leading to a corresponding signal input pad, the signal input pad being located between the at least one pair of staggered drop ejector rows; and At least one common general ground line is connected to the ground line, which is above and aligned with the first and second side walls of each pressure chamber, wherein the at least one common general ground line extends along the row direction and leads to at least one return ground pad.

2. The piezoelectric inkjet printing device according to claim 1, characterized in that: At least one common ground line is disposed between a signal input pad of a first staggered drop ejector row and a signal input pad of a second staggered drop ejector row in at least one pair of staggered drop ejector rows.

3. The piezoelectric inkjet printing device according to claim 1, characterized in that: The signal input pads of at least one pair of staggered drop ejector rows are disposed near a first end of the corresponding pressure chamber, and at least one common ground line is disposed near a second end of the corresponding pressure chamber, the second end being an end opposite to the first end.

4. The piezoelectric inkjet printing device according to claim 1, characterized in that: A first row of the at least one pair of staggered drop ejector rows and a second row of the at least one pair of staggered drop ejector rows are spaced from each other along a first direction perpendicular to the row direction.

5. The piezoelectric inkjet printing device according to claim 1, characterized in that: The spray hole is arranged at the first end of the pressure chamber close to the signal input pad.

6. The piezoelectric inkjet printing device according to claim 5, characterized in that: The drop ejector also includes an ink inlet in fluid communication with the pressure chamber, wherein the ink inlet is located adjacent a second end of the pressure chamber opposite the first end.

7. The piezoelectric inkjet printing device according to claim 1, characterized in that: The piezoelectric plate is polarized in a direction perpendicular to the first surface of the piezoelectric plate.

8. The piezoelectric inkjet printing device according to claim 1, characterized in that: Orifices of a first staggered drop ejector row are adjacent to orifices of a second staggered drop ejector row, wherein pressure chambers of the first staggered drop ejector row and pressure chambers of the second staggered drop ejector row extend in opposite directions from the respective orifices.

9. The piezoelectric inkjet printing device according to claim 1, characterized in that: T is less than 0.5W.

10. The piezoelectric inkjet printing device according to claim 9, characterized in that: T is less than 0.3W.

11. The piezoelectric inkjet printing device according to claim 1, characterized in that: The distance between the signal line and the adjacent ground line is greater than 0.1W.

12. The piezoelectric inkjet printing device according to claim 1, characterized in that: The width of the signal line is greater than 0.1W.

13. The piezoelectric inkjet printing device according to claim 1, characterized in that: The distance between the signal line and the adjacent ground line is greater than 0.5T and less than 2T.

14. The piezoelectric inkjet printing device according to claim 1, characterized in that: The width of the signal line is greater than 0.2T.

15. The piezoelectric inkjet printing device according to claim 1, characterized in that: Each signal line is disposed on a corresponding pressure chamber and extends in a direction perpendicular to the row direction.

16. The piezoelectric inkjet printing device according to claim 15, characterized in that: Each signal line is disposed over the center of a corresponding pressure chamber.

17. The piezoelectric inkjet printing device according to claim 1, characterized in that: The ground line is disposed at a middle position between the corresponding pressure chambers and extends in a direction perpendicular to the row direction.

18. The piezoelectric inkjet printing device according to claim 1, characterized in that: The width of the ground line is greater than the width of the side wall of the pressure chamber.

19. The piezoelectric inkjet printing device according to claim 1, characterized in that: The invention further comprises a shielding layer disposed on the electrode layer, wherein the shielding layer comprises windows on the signal input pad and on at least one ground return pad.

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