Liquid discharge head, head module, and liquid discharge device

Abstract

To provide a liquid discharge head capable of reducing differences in discharge velocity caused by differences in response speed among piezoelectric elements within a nozzle row, without relying on control of a drive waveform.SOLUTION: A liquid discharge head 100 includes: a nozzle plate 1 having a nozzle row 4a in which a plurality of nozzles 4 are arranged; a plurality of liquid chambers 6 respectively communicating with the nozzles 4; a diaphragm 3 forming part of a wall surface of the liquid chamber 6; a piezoelectric element 12 which is formed on a rear surface of a surface opposite to the liquid chambers 6 of the diaphragm 3 and expands and contracts in accordance with an applied voltage to pressurize liquid inside the liquid chambers; and a base member 13 which fixes the piezoelectric element 12. The pressurized liquid is discharged from the nozzles 4. The thickness and / or rigidity of the base member 13 differ between a central portion and both end portions in a nozzle arrangement direction of the nozzle row 4a.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head, a head module, and a liquid ejection apparatus. [Background technology]

[0002] A known liquid ejection head uses a piezoelectric element as a pressure generating means (actuator means) and is configured to eject droplets from a nozzle by applying a predetermined drive voltage to the piezoelectric element. It is also known that the ejection speed of droplets from a liquid ejection head has a variable characteristic.

[0003] Here, in a liquid ejection head equipped with a nozzle plate in which a plurality of nozzles are arranged in the main scanning direction of the ejection receiving medium, there is a problem in that the droplet ejection speed differs between the nozzles in the center and the nozzles at the ends within the same nozzle row. In a mode in which liquid is ejected while the liquid ejection head or the ejection receiving medium is moved, if the liquid ejection speed changes, the landing position will shift, which will lead to a decrease in image quality in an inkjet printer, for example.

[0004] In response to this, Patent Document 1 discloses a technology that includes an ejection force generating means that uses a drive waveform to generate an ejection force that ejects droplets corresponding to each of a plurality of nozzles, and a drive waveform application unit that selectively applies to the nozzles a drive waveform composed of a first drive signal and a second drive signal to generate the ejection force from the ejection force generating means, and in which the drive waveform application unit applies the first drive signal to the center of the nozzle row and the second drive signal to the end of the nozzle row, thereby reducing the difference in ejection speed in the nozzle row. Summary of the Invention [Problem to be solved by the invention]

[0005] However, a configuration in which a plurality of drive waveforms are generated and selected in order to reduce the difference in ejection speed between nozzle rows, as in Patent Document 1, has the problem of making the control system complex. On the other hand, although the ejection speed of the liquid from the nozzle is correlated with the response speed of the piezoelectric element, there is no disclosure of eliminating the difference in ejection speed caused by the difference in response speed of the piezoelectric element.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a liquid ejection head that can reduce differences in ejection speed caused by differences in response speed of piezoelectric elements within a nozzle row, without relying on control of drive waveforms. [Means for solving the problem]

[0007] In order to solve the above problems, the liquid ejection head of the present invention comprises a nozzle plate having a nozzle row in which a plurality of nozzles are arranged, a plurality of liquid chambers each connected to the plurality of nozzles, a vibration plate forming part of the wall surface of the liquid chamber, a piezoelectric element formed on the back surface of the vibration plate opposite the liquid chamber, which expands and contracts in response to the application of voltage and pressurizes the liquid inside the liquid chamber, and a base member for fixing the piezoelectric element, and is characterized in that the thickness and / or rigidity of the base member differs between the center and both end sides in the nozzle arrangement direction of the nozzle row. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a liquid ejection head that can reduce differences in ejection speed caused by differences in response speed of piezoelectric elements within a nozzle row without relying on control of drive waveforms. [Brief explanation of the drawings]

[0009] [Figure 1] 1A is a schematic perspective view of an example of a liquid ejection head, and FIG. 1B is an explanatory diagram of a nozzle surface. [Figure 2] FIG. 1 is a schematic cross-sectional view illustrating an example of a liquid ejection head. [Figure 3] FIG. 1 is a schematic cross-sectional view illustrating an example of a liquid ejection head. [Figure 4] FIG. 1 is a schematic explanatory diagram of a piezoelectric actuator. [Figure 5]10 is a graph showing an example of the relationship between the response time of a piezoelectric element and the ejection speed. [Figure 6] FIG. 2 is an exploded perspective view illustrating an example of a head module. [Figure 7] FIG. 2 is an exploded perspective view illustrating an example of a head module. [Figure 8] FIG. 10 is a schematic perspective view showing another example of a liquid ejection head. [Figure 9] FIG. 10 is a schematic cross-sectional view showing another example of a liquid ejection head. [Figure 10] FIG. 1 is a schematic explanatory diagram of a printing apparatus as an example of a liquid ejection apparatus. [Figure 11] FIG. 2 is a schematic diagram illustrating an example of a head unit. [Figure 12] FIG. 10 is a schematic diagram of another example of a liquid ejection device; [Figure 13] FIG. 10 is a schematic diagram of another example of the liquid ejection device. [Figure 14] FIG. 2 is a schematic diagram illustrating an example of a liquid ejection unit. [Figure 15] FIG. 10 is a schematic diagram illustrating another example of the liquid ejection unit. [Figure 16] 1 is an explanatory diagram showing a configuration of a main part of an electrode manufacturing apparatus as an example of a liquid ejection apparatus; DETAILED DESCRIPTION OF THE INVENTION

[0010] The liquid ejection head, head module, and liquid ejection device according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following embodiments, and other modifications, additions, corrections, deletions, and other changes can be made within the scope of what a person skilled in the art can conceive. Any aspect that achieves the functions and effects of the present invention is included in the scope of the present invention.

[0011] [Liquid ejection head] An example of the basic configuration of a liquid ejection head will be described below with reference to the accompanying drawings. FIG. 1A is a schematic diagram showing the appearance of a liquid ejection head, and FIG. 1B is a schematic plan view showing an example of a nozzle surface.

[0012] The bottom surface of the liquid ejection head 100 is a nozzle plate 1, and liquid is ejected from nozzles 4 provided in the nozzle plate 1. The liquid is supplied from supply ports 70. The arrangement and number of the supply ports 70 are not limited to those shown in the figure. Furthermore, the liquid ejection head 100 may be provided with a holding member 103 for holding the head, and a cover 29, as shown in FIG.

[0013] The nozzle plate 1 has a nozzle row 4a in which a plurality of nozzles 4 are arranged. The nozzle row may be a single row, or multiple rows as shown in Fig. 1(B). Furthermore, when multiple nozzle rows are provided, the nozzle rows may be shifted so that the nozzles 4 are arranged in a staggered pattern.

[0014] FIG. 2 is a cross-sectional explanatory view taken along a direction (longitudinal direction of the pressure chambers) perpendicular to the nozzle arrangement direction of the liquid ejection head, and FIG. 3 is a cross-sectional explanatory view taken along the nozzle arrangement direction.

[0015] The liquid ejection head 100 is formed by laminating and joining a nozzle plate 1, a flow path plate 2 which is an individual flow path member, and a vibration plate (hereinafter also referred to as a vibration plate member) 3 which serves as a wall member. It is also equipped with a piezoelectric actuator 11 (actuator) which displaces a vibration region (vibration plate) 30 of the vibration plate member 3, and a common flow path member 20 which also serves as a frame member for the head. The nozzle plate 1 has a nozzle row in which a plurality of nozzles 4 which eject liquid are arranged.

[0016] The flow path plate 2 has formed therein a plurality of liquid chambers (also called individual liquid chambers, pressure chambers, etc.) 6 that communicate with a plurality of nozzles 4, individual supply flow paths 7 that are individual flow paths that communicate with each of the liquid chambers 6, and an intermediate supply flow path 8 that serves as a liquid introduction section that communicates with one or more (one in this embodiment) individual supply flow paths 7.

[0017] The vibration plate member 3 has a plurality of displaceable vibration plates (vibration regions) 30 that form the wall surfaces of the liquid chamber 6 of the flow path plate 2. Here, the vibration plate member 3 has a two-layer structure (not limited to this) and is composed of a first layer 3A that forms a thin portion from the flow path plate 2 side and a second layer 3B that forms a thick portion.

[0018] A deformable vibration region 30 is formed in the first layer 3A, which is a thin portion, in a portion corresponding to the liquid chamber 6. Within the vibration region 30, a convex portion 30a, which is a thick portion that is bonded to the piezoelectric actuator 11, is formed in the second layer 3B.

[0019] A piezoelectric actuator 11 including an electromechanical conversion element is arranged on the opposite side (back surface) of the vibration plate member 3 from the liquid chamber 6, as a driving means (actuator means, pressure generating means) for deforming the vibration region 30 of the vibration plate member 3.

[0020] This piezoelectric actuator 11 is formed by forming grooves by half-cut dicing in a piezoelectric member bonded to a base member 13, and forming a required number of columnar piezoelectric elements 12 in a comb-like shape at specified intervals in the nozzle arrangement direction. The piezoelectric elements 12 are then bonded to protrusions 30a, which are thick portions formed in the vibration region 30 of the vibration plate member 3.

[0021] This piezoelectric element 12 is formed by alternately laminating piezoelectric layers and internal electrodes, and the internal electrodes are drawn out to the end surfaces and connected to external electrodes (end surface electrodes), and flexible wiring member 15 is connected to the external electrodes. The piezoelectric element 12 expands and contracts in response to the application of a voltage.

[0022] The common flow path member 20 forms a common supply flow path 10 that communicates with the multiple liquid chambers 6. The common supply flow path 10 communicates with an intermediate supply flow path 8, which serves as a liquid introduction section, via an opening 9 provided in the vibration plate member 3, and communicates with the individual supply flow paths 7 via the intermediate supply flow path 8.

[0023] In this liquid ejection head 100, for example, by lowering the voltage applied to the piezoelectric element 12 from a reference potential (intermediate potential), the piezoelectric element 12 contracts, the vibration area 30 of the vibration plate member 3 is pulled, and the volume of the liquid chamber 6 expands, causing liquid to flow into the liquid chamber 6.

[0024] Thereafter, the voltage applied to the piezoelectric element 12 is increased to expand the piezoelectric element 12 in the stacking direction, and the vibration region 30 of the vibration plate member 3 is deformed in the direction toward the nozzle 4, thereby contracting the volume of the liquid chamber 6, thereby pressurizing the liquid in the liquid chamber 6 and ejecting the liquid from the nozzle 4.

[0025] FIG. 5 shows the relationship between the response time of the piezoelectric elements 12 in the nozzle row and the ejection speed of the liquid from the nozzles 4. The response time of the piezoelectric element 12 contributes to the timing at which the liquid is ejected from the nozzle 4. As shown in FIG. 5, there is a correlation between the response time (dashed line) and the ejection speed (solid line) of the piezoelectric element 12, with the response time of the piezoelectric element 12 being slower and the ejection speed being lower at the center of the nozzle row than at both ends.

[0026] If there is a difference in ejection speed within the same nozzle row, in a liquid ejection device in which liquid is ejected while the liquid ejection head or the ejection receiving medium is moved, it can lead to the problem that droplets cannot be landed at the desired position in the desired amount.

[0027] In contrast to this, the liquid ejection head according to the present invention has a configuration that eliminates the difference in ejection speed within the same nozzle row.

[0028] The liquid ejection head 100 according to the present invention comprises a nozzle plate 1 having a nozzle row 4a in which a plurality of nozzles 4 are arranged, a plurality of liquid chambers 6 each communicating with the plurality of nozzles 4, a vibration plate (vibration plate member) 3 forming part of the wall of the liquid chamber 6, a piezoelectric element 12 formed on the back surface of the vibration plate 3 opposite the liquid chamber 6, which expands and contracts in response to the application of voltage and pressurizes the liquid inside the liquid chamber, and a base member 13 for fixing the piezoelectric element 12, and the pressurized liquid is ejected from the nozzles 4, and the thickness and / or rigidity of the base member 13 differs between the center and both end sides in the nozzle arrangement direction of the nozzle row 4a.

[0029] The magnitude of the difference in thickness and / or rigidity of the base member 13 in the nozzle arrangement direction is a magnitude required to offset the difference in response time of the piezoelectric elements 12 in the nozzle arrangement direction.

[0030] Furthermore, the magnitude of the difference in thickness and / or rigidity of the base member 13 in the nozzle arrangement direction is a magnitude required to offset the difference in the liquid ejection speed in the nozzle arrangement direction.

[0031] In this embodiment, the expansion and contraction efficiency of the piezoelectric elements 12 at the center in the nozzle arrangement direction is higher than the expansion and contraction efficiency at both end sides in the nozzle arrangement direction. Here, "expansion efficiency" means the displacement rate (driving efficiency) per unit input. Specifically, by increasing the expansion / contraction efficiency, the efficiency of expanding / contracting the volume of the liquid chamber 6 can be increased, and the speed at which the liquid is ejected from the nozzle 4 can be increased. As a result, delays in the ejection timing can be eliminated. On the other hand, by decreasing the expansion / contraction efficiency, the efficiency of expanding / contracting the volume of the liquid chamber 6 can be decreased, and the speed at which the liquid is ejected from the nozzle 4 can be decreased.

[0032] It is preferable to adjust the expansion / contraction efficiency of the piezoelectric elements 12 in the nozzle arrangement direction so that the expansion / contraction efficiency of the piezoelectric elements 12 at both ends in the nozzle arrangement direction is reduced and the expansion / contraction efficiency of the piezoelectric elements 12 in the center in the nozzle arrangement direction is improved.

[0033] 4 is a schematic side view showing the base member 13 that constitutes the piezoelectric actuator 11 and the piezoelectric element 12 bonded onto the base member 13. Only a portion of the piezoelectric element 12 in the thickness direction (near the bonding area with the base member 13) is shown. 4(A) shows a conventional example of piezoelectric actuator 11, and Figures 4(B) and (C) show examples according to the present invention. In each figure, the thickness of one end of base member 13 in the nozzle direction is indicated by T1, the thickness of the central portion by T2, and the thickness of the other end by T3.

[0034] As shown in Figures 4(B) and 4(C), the liquid ejection head 100 of this embodiment has a structure in which the thickness T2 at the center of the base member 13 in the nozzle arrangement direction is thicker than the thicknesses T1 and T3 at both ends in the nozzle arrangement direction. Furthermore, the thicknesses T1 and T3 in the examples of FIGS. 4(B) and 4(C) are set to be thinner than the thicknesses T1 and T3 in the conventional example shown in FIG. 4(A).

[0035] The thicknesses of T1 and T3 are approximately the same. The difference in thickness between T1 and T2 and the difference in thickness between T2 and T3 are preferably set based on a magnitude required to offset the difference in response time of the piezoelectric elements 12 in the nozzle arrangement direction. Furthermore, the difference in thickness between T1 and T2 and the difference in thickness between T2 and T3 are preferably set based on the magnitude required to offset the difference in ejection speed in the nozzle arrangement direction.

[0036] As shown in Fig. 5, the response time and ejection speed of the piezoelectric element 12 gradually change from the end side to the center. Therefore, it is preferable that the difference in thickness be set so that it gradually increases from the end side to the center, as in the example shown in Fig. 4(C). Note that the shape is not limited to the example shown in Fig. 4(C).

[0037] The rigidity of the base member 13 also changes depending on the thickness. As shown in Figures 4(B) and 4(C), the liquid ejection head 100 of this embodiment has a structure in which the thickness T2 at the center of the base member 13 in the nozzle arrangement direction is thicker than the thicknesses T1 and T3 at both ends in the nozzle arrangement direction, so that the rigidity at the center in the nozzle arrangement direction is higher than the rigidity at both ends in the nozzle arrangement direction. Moreover, the rigidity of both end sides in the examples of FIGS. 4(B) and (C) is lower because the thicknesses are set thinner than the thicknesses T1 and T3 in the example shown in FIG. 4(A).

[0038] The thicknesses of T1 and T3 are approximately the same, and the rigidity on both ends in the nozzle arrangement direction is also approximately the same. The magnitude of the difference in stiffness in the nozzle arrangement direction is preferably set based on the magnitude required to offset the difference in response time of the piezoelectric elements 12 in the nozzle arrangement direction. Furthermore, it is preferable that the magnitude of the difference in stiffness in the nozzle arrangement direction is set based on the magnitude required to offset the difference in ejection speed in the nozzle arrangement direction.

[0039] The expansion and contraction efficiency of the piezoelectric element 12 changes depending on the rigidity of the base member 13 to which it is joined. The liquid ejection head 100 of this embodiment is structured so that the thickness (T2) of the base member 13 at the center in the nozzle arrangement direction is thicker than the thicknesses (T1, T3) at both end sides in the nozzle arrangement direction, and by making the rigidity at the center higher than the rigidity at both end sides, the expansion and contraction efficiency of the piezoelectric element 12 at the center in the nozzle arrangement direction can be made higher than the expansion and contraction efficiency at both end sides in the nozzle arrangement direction.

[0040] In the center in the nozzle arrangement direction where the rigidity of the base member 13 is high, the expansion and contraction efficiency of the piezoelectric element 12 is high, which improves the efficiency of expanding and contracting the volume of the liquid chamber 6 and increases the ejection speed. On the other hand, at both ends in the nozzle direction where the rigidity of the base member 13 is low, the expansion and contraction efficiency of the piezoelectric element 12 is low, which decreases the efficiency of expanding and contracting the volume of the liquid chamber 6 and decreases the ejection speed. As a result, the difference in ejection speed in the nozzle arrangement direction is eliminated.

[0041] In the example of FIG. 4, the rigidity of the base member 13 is adjusted by changing the thickness, but the rigidity may be adjusted by changing the material without changing the thickness.

[0042] Fig. 6 is a perspective view of a liquid ejection head according to yet another embodiment, and Fig. 7 is an explanatory cross-sectional view taken along a direction (longitudinal direction of the pressure chambers) perpendicular to the nozzle arrangement direction of the liquid ejection head according to this embodiment. The liquid ejection head 100 according to this embodiment is a circulation-type liquid ejection head, and is formed by laminating and bonding a nozzle plate 1, a flow path plate 2, and a vibration plate member 3 serving as a wall member. It also includes a piezoelectric actuator 11 that displaces the vibration region 30 of the vibration plate member 3, and a common flow path member 20 that also serves as a frame member for the head.

[0043] The flow path plate 2 has formed therein a plurality of liquid chambers 6 each connected to a plurality of nozzles 4 via a nozzle connecting passage 5, a plurality of individual supply flow paths 7 each connected to the plurality of liquid chambers 6 and also serving as fluid resistance sections, and an intermediate supply flow path 8 which serves as one or more liquid introduction sections connected to two or more individual supply flow paths 7.

[0044] As in the above embodiment, the individual supply flow path 7 includes two flow path sections, a first flow path section 7A and a second flow path section 7B, which have higher fluid resistance than the liquid chamber 6, and a third flow path section 7C, which is arranged between the first flow path section 7A and the second flow path section 7B and has lower fluid resistance than the first flow path section 7A and the second flow path section 7B.

[0045] The flow path plate 2 is formed by stacking a plurality of plate-like members 2A to 2E, but is not limited to this.

[0046] In addition, the flow path plate 2 forms a plurality of individual recovery flow paths 57 along the surface direction of the flow path plate 2, each of which is connected to a plurality of liquid chambers 6 via a nozzle connecting passage 5, and an intermediate recovery flow path 58 which serves as one or more liquid discharge sections connected to two or more individual recovery flow paths 57.

[0047] The individual recovery flow path 57 includes two flow path sections, a first flow path section 57A and a second flow path section 57B, which have higher fluid resistance than the liquid chamber 6, and a third flow path section 57C, which is disposed between the first flow path section 57A and the second flow path section 57B and has lower fluid resistance than the first flow path section 57A and the second flow path section 57B. The individual recovery flow path 57 has a flow path section 57D, which is downstream of the second flow path section 57B in the circulation direction, and which has the same flow path width as the third flow path section 57C.

[0048] The common flow path member 20 forms a common supply flow path 10 and a common recovery flow path 50. In this embodiment, the common supply flow path 10 is made up of a flow path portion 10A that is aligned with the common recovery flow path 50 in the nozzle arrangement direction, and a flow path portion 10B that is not aligned with the common recovery flow path 50.

[0049] The common supply flow path 10 communicates with an intermediate supply flow path 8, which serves as a liquid introduction portion, via an opening 9 provided in the vibration plate member 3, and communicates with the individual supply flow paths 7 via the intermediate supply flow path 8. The common recovery flow path 50 communicates with an intermediate recovery flow path 58, which serves as a liquid discharge portion, via an opening 59 provided in the vibration plate member 3, and communicates with the individual recovery flow paths 57 via the intermediate recovery flow path 58.

[0050] In addition, the common supply flow path 10 communicates with a supply port 71 , and the common recovery flow path 50 communicates with a recovery port 72 .

[0051] The other configurations of the diaphragm member 3 and the piezoelectric actuator 11 are the same as those in the above example.

[0052] In this liquid ejection head 100, the piezoelectric element 12 is stretched in the stacking direction, and the vibration area 30 of the vibration plate member 3 is deformed in the direction toward the nozzle 4, thereby contracting the volume of the liquid chamber 6, thereby pressurizing the liquid in the liquid chamber 6 and ejecting the liquid from the nozzle 4.

[0053] In the liquid ejection head of this embodiment, as in the example shown in Figures 4(B) and (C), the thickness and / or rigidity of the base member 13 differs between the center and both end sides in the nozzle arrangement direction of the nozzle row. The difference in thickness and / or rigidity of the base member 13 in the nozzle arrangement direction is the same as the difference in response time of the piezoelectric element 12 in the nozzle arrangement direction, and is the same as the difference in liquid ejection speed, so that the difference in ejection speed in the nozzle row direction is eliminated.

[0054] Liquid that is not ejected from the nozzles 4 passes through the nozzles 4 and is recovered from the individual recovery flow path 57 to the common recovery flow path 50, and is then supplied again from the common recovery flow path 50 to the common supply flow path 10 via an external circulation path. Also, even when liquid is not being ejected from the nozzles 4, liquid circulates from the common supply flow path 10 to the common recovery flow path 50 via the liquid chamber 6, and is then supplied again to the common supply flow path 10 via an external circulation path.

[0055] [Head module] Next, an example of a head module according to the present invention will be described with reference to Figures 8 and 9. Figure 8 is an exploded perspective view of the head module, and Figure 9 is an exploded perspective view of the head module as seen from the nozzle surface side. The head module according to the present invention has a plurality of liquid ejection heads 100 according to the present invention arranged therein.

[0056] The head module 200 includes a plurality of heads 100 which are liquid ejection heads that eject liquid, a holding member 103 that holds the plurality of heads 100, and a cover member 113 that serves as a nozzle cover for the plurality of heads 100. The head module 200 also includes a heat dissipation member 104, a manifold 105 that forms a flow path for supplying liquid to a plurality of heads, a printed circuit board (PCB) 106 that connects to the flexible wiring member 101, and a module case 107.

[0057] [Liquid ejection device, liquid ejection unit] An example of a liquid ejection device according to the present invention will be described with reference to Figures 10 and 11. Figure 10 is a schematic explanatory diagram of a liquid ejection device, and Figure 11 is a plan explanatory diagram of an example of a head unit provided in the device of Figure 10.

[0058] The liquid ejection device according to the present invention includes the liquid ejection head 100 according to the present invention described above.

[0059] The printing device 500, which is a liquid ejection device, includes an input means 501 for inputting a continuous body 510 such as continuous paper or sheet material, which is a recording medium; a guide and conveying means 503 for guiding and conveying the continuous body 510 inputted from the input means 501 to a printing means 505; the printing means 505 for ejecting liquid onto the continuous body 510 to form an image; a drying means 507 for drying the continuous body 510; and an ejection means 509 for ejecting the continuous body 510.

[0060] The continuous body 510 is fed from the original winding roller 511 of the carrying-in means 501 , guided and conveyed by the rollers of the carrying-in means 501 , the guide and conveying means 503 , the drying means 507 and the carrying-out means 509 , and wound up by the winding roller 591 of the carrying-out means 509 .

[0061] In the printing means 505, this continuum 510 is transported on a transport guide member 559 opposite the head unit 550 and head unit 555, an image is formed by liquid ejected from the head unit 550, and post-processing is performed by processing liquid ejected from the head unit 555.

[0062] The head unit is, for example, a row of head modules each including an array of the liquid ejection heads according to the present invention. Here, in the head unit 550, for example, full line type head arrays 551A, 551B, 551C, and 551D (hereinafter referred to as "head array 551" when no distinction is made between colors) for four colors are arranged from the upstream side in the transport direction.

[0063] Each head array 551 is a liquid ejection means, and ejects liquid of black K, cyan C, magenta M, or yellow Y onto the conveyed continuum 510. Note that the types and numbers of colors are not limited to these.

[0064] The head array 551 is, for example, a liquid ejection head (also simply referred to as a "head") 100 according to the present invention arranged in a staggered pattern on a base 552, but is not limited to this.

[0065] Next, another example of a printing apparatus as a liquid ejection apparatus according to the present invention will be described with reference to Figures 12 and 13. Figure 12 is an explanatory plan view of the main parts of the apparatus, and Figure 13 is an explanatory side view of the main parts of the apparatus.

[0066] The printing device 500 is a serial type device, and a carriage 403 is moved back and forth in the main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is hung between left and right side plates 491A and 491B and movably holds the carriage 403. The main scanning motor 405 then moves the carriage 403 back and forth in the main scanning direction via a timing belt 408 hung between a drive pulley 406 and a driven pulley 407.

[0067] This carriage 403 is equipped with a liquid ejection unit 440 that integrates a liquid ejection head 100 according to the present invention and a head tank 441. The liquid ejection head 100 of the liquid ejection unit 440 ejects liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid ejection head 100 is mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and the ejection direction facing downward.

[0068] This printing apparatus 500 is equipped with a transport mechanism 495 for transporting paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412.

[0069] The conveyor belt 412 attracts the paper 410 and conveys it at a position facing the liquid ejection head 100. The conveyor belt 412 is an endless belt that is stretched between a conveyor roller 413 and a tension roller 414. The paper can be attracted by electrostatic attraction or air suction.

[0070] The conveyor belt 412 moves in a circular motion in the sub-scanning direction when the conveyor roller 413 is rotationally driven by a sub-scanning motor 416 via a timing belt 417 and a timing pulley 418 .

[0071] Furthermore, a maintenance and recovery mechanism 420 for performing maintenance and recovery of the liquid ejection head 100 is disposed on one side of the conveyor belt 412 on one side of the carriage 403 in the main scanning direction.

[0072] The maintenance and recovery mechanism 420 is made up of, for example, a cap member 421 that caps the nozzle surface (the surface on which the nozzles are formed) of the liquid ejection head 100, a wiper member 422 that wipes the nozzle surface, and the like.

[0073] The main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the transport mechanism 495 are attached to a housing including side plates 491A and 491B and a back plate 491C.

[0074] In the printing device 500 configured in this manner, the paper 410 is fed onto the conveyor belt 412 and adsorbed thereon, and the paper 410 is conveyed in the sub-scanning direction by the circular movement of the conveyor belt 412.

[0075] Therefore, by driving the liquid ejection head 100 in accordance with an image signal while moving the carriage 403 in the main scanning direction, liquid is ejected onto the stationary paper 410 to form an image.

[0076] By being equipped with the liquid ejection head according to the present invention, the printing device of this embodiment reduces the difference in ejection speed caused by the difference in response speed of the piezoelectric elements within the nozzle row, and there is no deviation in the ink landing position, making it possible to produce high-quality images.

[0077] An example of a liquid ejection unit will be described with reference to Figures 14 and 15. The liquid ejection unit according to this embodiment includes the liquid ejection head 100 according to the present invention described above.

[0078] Examples of liquid ejection units include a liquid ejection head integrated with at least one of the following: a head tank that stores liquid to be supplied to the liquid ejection head; a carriage that mounts the liquid ejection head; a supply mechanism that supplies liquid to the liquid ejection head; a maintenance and recovery mechanism that maintains and recovers the liquid ejection head; and a main scanning movement mechanism that moves the liquid ejection head in the main scanning direction.

[0079] FIG. 14 is a plan view illustrating a main part of an example of a liquid ejection unit. This liquid ejection unit 440 is composed of the components that make up the liquid ejection device, including a housing portion consisting of side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid ejection head 100.

[0080] It is also possible to configure a liquid discharge unit in which the above-described maintenance and recovery mechanism 420 is further attached to, for example, the side plate 491B of this liquid discharge unit 440.

[0081] FIG. 15 is an explanatory front view showing an example of a liquid ejection unit. This liquid ejection unit 440 is composed of a liquid ejection head 100 to which a flow path part 444 is attached, and a tube 456 connected to the flow path part 444 .

[0082] The flow path part 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path part 444. A connector 443 for electrically connecting with the liquid ejection head 100 is provided on the upper part of the flow path part 444.

[0083] <Electrode manufacturing equipment> The "liquid ejection device" according to the present invention also includes a manufacturing device for electrodes and electrochemical elements. An electrode manufacturing device will be described below.

[0084] 16 is a schematic diagram showing an example of an electrode manufacturing apparatus according to an embodiment of the present invention, which manufactures an electrode including a layer having an electrode material by ejecting a liquid composition using a head module including a liquid ejection head.

[0085] <Means for forming layer containing electrode material, and process for forming layer containing electrode material> The discharge means provided in the electrode manufacturing apparatus shown in FIG. 16 is a head module 200 provided with the liquid discharge head 100 according to the embodiment of the present invention. The liquid composition is applied to a target object by ejecting it from the liquid ejection head 100 of the head module 200, thereby forming a liquid composition layer. The target object (hereinafter sometimes referred to as "ejection target") is not particularly limited as long as it is an object on which a layer containing an electrode material is to be formed, and can be appropriately selected depending on the purpose. For example, the target object may be an electrode substrate (current collector), an active material layer, a layer containing a solid electrode material, etc. The target object may also be an electrode mixture layer containing an active material on an electrode substrate (current collector). The ejection means and ejection process may also be means and processes for forming a layer containing an electrode material by directly ejecting the liquid composition, as long as it is possible to form a layer containing an electrode material on the ejection target object. The ejection means and ejection process may also be means and processes for forming a layer containing an electrode material by indirectly ejecting the liquid composition.

[0086] <Other components and processes> Other components included in the manufacturing apparatus for an electrode mixture layer are not particularly limited as long as they do not impair the effects of the present invention, and can be selected appropriately depending on the purpose. Furthermore, other steps included in the manufacturing method for an electrode mixture layer are also not particularly limited as long as they do not impair the effects of the present invention, and can be selected appropriately depending on the purpose. For example, components and steps included in the manufacturing apparatus and manufacturing method for an electrode mixture layer include a heating means and a heating step.

[0087] <Heating means, heating process> The heating means included in the manufacturing device for the electrode mixture layer is a means for heating the liquid composition ejected by the ejection means. Also, the heating step included in the manufacturing method for the electrode mixture layer is a step of heating the liquid composition ejected in the ejection step. By heating the liquid composition, the liquid composition layer can be dried.

[0088] <Configuration for forming a layer containing an electrode material by directly ejecting a liquid composition> Here, as an example of an electrode manufacturing apparatus, an electrode manufacturing apparatus that forms an electrode mixture layer containing an active material on an electrode substrate (current collector) will be described. As shown in Fig. 16, the electrode manufacturing apparatus includes a discharge process unit 710 that includes a step of applying a liquid composition to a printing substrate 704 having an object to be discharged to form a liquid composition layer, and a heating process unit 730 that includes a heating step of heating the liquid composition layer to obtain an electrode mixture layer.

[0089] The electrode manufacturing apparatus includes a conveying section 705 that conveys a printing substrate 704. The conveying section 705 conveys the printing substrate 704 at a preset speed through a discharge process section 710 and a heating process section 730 in that order. The method for manufacturing the printing substrate 704 having a discharge target such as an active material layer is not particularly limited, and any known method can be appropriately selected. The discharge process section 710 includes a liquid discharge head 100 that performs an application process of applying a liquid composition onto the printing substrate 704, a storage container 281b that stores the liquid composition 707, and a supply tube 281c that supplies the liquid composition 707 stored in the storage container 281b to the liquid discharge head 100.

[0090] In the ejection process unit 710, the liquid composition 707 is ejected from the liquid ejection head 100 and applied to the printing substrate 704, thereby forming a thin film of the liquid composition layer. The storage container 281b may be integrated with the manufacturing apparatus for the electrode mixture layer, or may be detachable from the manufacturing apparatus for the electrode mixture layer. The storage container 281b may be a container used for adding the liquid to a storage container integrated with the manufacturing apparatus for the electrode mixture layer, or a storage container detachable from the manufacturing apparatus for the electrode mixture layer.

[0091] The storage container 281b and the supply tube 281c can be arbitrarily selected as long as they can stably store and supply the liquid composition 707.

[0092] In the heating process section 730, a solvent removal step is carried out in which the solvent remaining in the liquid composition layer is heated and removed. Specifically, the solvent remaining in the liquid composition layer is heated and dried by the heating device 703 in the heating process section 730, thereby removing the solvent from the liquid composition layer. This results in the formation of an electrode mixture layer. The solvent removal step in the heating process section 730 may also be carried out under reduced pressure.

[0093] The heating device 703 is not particularly limited and can be appropriately selected depending on the purpose. For example, the heating device 703 can be a substrate heater, an IR heater, a hot air heater, or the like. The heating device 703 may also be a combination of at least two of the substrate heater, the IR heater, and the hot air heater. The heating temperature and heating time can be appropriately selected depending on the boiling point of the solvent contained in the liquid composition 707 or the thickness of the formed film.

[0094] By using the electrode manufacturing device according to the embodiment of the present invention, it is possible to eject a liquid composition at a targeted location on an object to be ejected. Furthermore, by including the liquid ejection head according to the present invention, the difference in ejection speed caused by the difference in response speed of the piezoelectric elements in the nozzle row is reduced, and deviation in the landing position does not occur, so a high-quality electrode mixture layer can be formed.

[0095] The electrode mixture layer can be suitably used, for example, as a part of the configuration of an electrochemical element. The components other than the electrode mixture layer in the electrochemical element are not particularly limited, and known components can be appropriately selected. For example, components other than the electrode mixture layer include a positive electrode, a negative electrode, a separator, and the like.

[0096] In the present application, the liquid to be ejected may have a viscosity and surface tension that allows it to be ejected from the head, and is not particularly limited, but preferably has a viscosity of 30 mPa·s or less at room temperature and normal pressure, or upon heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, or the like containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a polymerizable compound, a resin, a surfactant, or the like, a biocompatible material such as DNA, amino acids, proteins, or calcium, or an edible material such as a natural colorant, and the like. These liquids can be used, for example, as inkjet inks, surface treatment liquids, liquids for forming components of electronic devices or light-emitting elements, or electronic circuit resist patterns, and material liquids for 3D modeling.

[0097] A head module (liquid ejection unit) is a liquid ejection head integrated with functional parts and mechanisms, and includes a collection of parts related to liquid ejection. For example, a head module (liquid ejection unit) may include a combination of a liquid ejection head and at least one of the following components: a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, and a liquid circulation device.

[0098] The term "liquid ejection device" includes devices that have a liquid ejection head or a liquid ejection unit and eject liquid by driving the liquid ejection head. Liquid ejection devices include not only devices that can eject liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

[0099] This "liquid ejection device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

[0100] For example, examples of "liquid ejection devices" include image forming devices, which are devices that eject ink to form images on paper, and three-dimensional modeling devices (three-dimensional modeling devices), which eject modeling liquid onto a powder layer formed from layers of powder in order to create a three-dimensional object (a three-dimensional model).

[0101] Furthermore, the term "liquid ejection device" is not limited to devices that visualize meaningful images such as letters and figures using ejected liquid. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

[0102] The above-mentioned "object onto which a liquid can adhere" means an object onto which a liquid can adhere at least temporarily, an object onto which the liquid can adhere and stick, an object onto which the liquid can penetrate, etc. Specific examples include media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects onto which a liquid can adhere.

[0103] The material of the "substance to which a liquid can adhere" may be any material to which a liquid can adhere, even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, or ceramics.

[0104] Furthermore, the term "liquid ejection device" includes, but is not limited to, a device in which a liquid ejection head and an object onto which liquid can be attached move relatively. Specific examples include a serial type device in which the liquid ejection head moves, and a line type device in which the liquid ejection head does not move.

[0105] Other examples of "liquid ejection devices" include a treatment liquid application device that ejects a treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and an injection granulation device that sprays a composition liquid in which raw materials are dispersed through a nozzle to granulate fine particles of the raw materials.

[0106] In the present application, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous.

[0107] For example, aspects of the present invention are as follows. <1> a nozzle plate having a nozzle row in which a plurality of nozzles are arranged; a plurality of liquid chambers respectively communicating with the plurality of nozzles; a vibration plate forming a part of the wall surface of the liquid chamber; a piezoelectric element formed on the back surface of the vibration plate opposite to the liquid chamber, the piezoelectric element expanding and contracting in response to application of a voltage to pressurize the liquid inside the liquid chamber; a base member for fixing the piezoelectric element; In a liquid ejection head in which pressurized liquid is ejected from the nozzle, The liquid ejection head is characterized in that the thickness and / or rigidity of the base member differs between the center and both end sides in the nozzle arrangement direction of the nozzle row. <2> The difference in thickness and / or rigidity of the base member in the nozzle arrangement direction is a value necessary to offset the difference in response time of the piezoelectric elements in the nozzle arrangement direction. <1> 1. The liquid ejection head according to claim 1. <3> The difference in thickness and / or rigidity of the base member in the nozzle arrangement direction is a value required to offset the difference in liquid ejection speed in the nozzle arrangement direction. <1> or <2> 1. The liquid ejection head according to claim 1. <4> The expansion and contraction efficiency of the piezoelectric element at the center in the nozzle arrangement direction is higher than the expansion and contraction efficiency at both end sides in the nozzle arrangement direction. <1> from <3> 1. The liquid ejection head according to claim 1, wherein the liquid ejection head is a liquid ejection head having a diameter of 100 mm or less. <5> The thickness of the base member at the center in the nozzle arrangement direction is greater than the thickness at both end sides in the nozzle arrangement direction. <1> from <4> 1. The liquid ejection head according to claim 1, wherein the liquid ejection head is a liquid ejection head having a diameter of 100 mm or less. <6> The rigidity of the base member at the center in the nozzle arrangement direction is higher than the rigidity at both end sides in the nozzle arrangement direction. <1> from <5> 1. The liquid ejection head according to claim 1, wherein the liquid ejection head is a liquid ejection head having a diameter of 100 mm or less. <7> The aforementioned <1> from <6> 1. A head module comprising a plurality of liquid ejection heads according to any one of claims 1 to 8 arranged in an array. <8> The aforementioned <1> from <6> 10. A liquid ejection unit comprising the liquid ejection head according to any one of claims 1 to 9. <9> The aforementioned <1> from <6> 10. A liquid ejection apparatus comprising the liquid ejection head according to any one of claims 1 to 9. <10> The aforementioned <1> from <6> 10. A printing apparatus comprising the liquid ejection head according to any one of claims 1 to 9. <11> The aforementioned <1> from <6> 10. An apparatus for manufacturing an electrode, comprising the liquid ejection head according to any one of claims 1 to 9. [Explanation of symbols]

[0108] 1 nozzle plate 2 Flow path plate 3 Vibration plate 6 4 nozzles 4a Nozzle row 11 Piezoelectric Actuator 12 Piezoelectric element 13 Base material 100 Liquid ejection head 200 Head Module 300 Liquid discharge device (electrode manufacturing device) 500 Liquid ejection device (printing device) [Prior art documents] [Patent documents]

[0109] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-334950

Claims

1. a nozzle plate having a nozzle row in which a plurality of nozzles are arranged; a plurality of liquid chambers respectively communicating with the plurality of nozzles; a vibration plate forming a part of the wall surface of the liquid chamber; a piezoelectric element formed on the back surface of the vibration plate opposite to the liquid chamber, the piezoelectric element expanding and contracting in response to application of a voltage to pressurize the liquid inside the liquid chamber; a base member for fixing the piezoelectric element; In a liquid ejection head in which pressurized liquid is ejected from the nozzle, A liquid ejection head characterized in that the thickness and / or rigidity of the base member differs between a central portion and both end portions in the nozzle arrangement direction of the nozzle row.

2. A liquid ejection head as described in claim 1, characterized in that the difference in thickness and / or rigidity of the base member in the nozzle arrangement direction is a magnitude necessary to offset the difference in response time of the piezoelectric element in the nozzle arrangement direction.

3. 2. A liquid ejection head according to claim 1, wherein the difference in thickness and / or rigidity of the base member in the nozzle arrangement direction is a magnitude necessary to offset the difference in liquid ejection speed in the nozzle arrangement direction.

4. 4. The liquid ejection head according to claim 1, wherein the expansion and contraction efficiency of the piezoelectric element at the center in the nozzle arrangement direction is higher than the expansion and contraction efficiency at both end sides in the nozzle arrangement direction.

5. 4. The liquid ejection head according to claim 1, wherein the thickness of the base member at the center in the nozzle arrangement direction is greater than the thickness at both end sides in the nozzle arrangement direction.

6. 4. The liquid ejection head according to claim 1, wherein the rigidity of the base member at the center in the nozzle arrangement direction is higher than the rigidity at both end sides in the nozzle arrangement direction.

7. A head module comprising a plurality of liquid ejection heads according to any one of claims 1 to 3 arranged in an array.

8. A liquid ejection apparatus comprising the liquid ejection head according to claim 1 .

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