Droplet discharge head, droplet discharge unit, and droplet discharge apparatus

Abstract

To provide a droplet discharge head which can inhibit occurrences of chips and cracks caused by external force and inhibit protruding of an adhesive.SOLUTION: A droplet discharge head 1 includes: a nozzle plate 10 having nozzles 11 for discharging droplets; a channel substrate 23 to which the nozzle plate 10 is joined and which is provided with individual channels 21 partitioned by partition walls 23a and communicating with the respective nozzles 11; and a piezoelectric element holding substrate 50 joined to a side, which is opposite to the nozzle plate 10, of the channel substrate 23. An outer wall of an end partition wall 23b which is the partition wall located at one end of the channel substrate 23 is located at the inner side relative to an outer wall of one end of the piezoelectric element holding substrate 50.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a droplet discharge head, a droplet discharge unit, and a droplet discharge device.

Background Art

[0002] Conventionally, a droplet discharge head employed in an inkjet type image forming apparatus is known. This droplet discharge head includes a flow path substrate that forms individual liquid chambers communicating with nozzles, a piezoelectric element holding substrate that is joined to the flow path substrate on the side opposite to the nozzle plate provided with the nozzles and has a recess in which a piezoelectric element is housed, a damper that dissipates vibration energy to reduce the amplitude of impact or vibration, and a damper holding substrate that has a space in which the damper can vibrate. Each member is joined by an adhesive or the like.

[0003] In the above-described droplet discharge head, when a head in which nozzles are arranged at a high density is arranged adjacent to form a droplet discharge unit, it is necessary to make the gap between the heads as narrow as possible from the viewpoint of suppressing the occurrence of density unevenness, and the nozzles, liquid chambers, etc. may be located near the end of the head. In such a configuration, when a chip or crack occurs in the head due to an external force acting from the outer periphery of the member, fluid leakage, disconnection of wiring, or a change in the flow path volume is likely to occur, and it becomes difficult to obtain a desired function. Further, since the outer peripheral partition walls of the flow path substrate and the piezoelectric element holding substrate are also thin, there is a risk that the protruding adhesive at the joining interface may interfere with other adjacent heads.

[0004] Therefore, a technique for providing a laminated structure of a thin plate-like member that can efficiently release adhesives and air bubbles while ensuring the rigidity of the thin plate-like member and reducing warpage is known (see, for example, "Patent Document 1"). In this technique, in a laminated structure in which a plurality of thin plate-like members are joined by an adhesive, at least one groove is formed in the short side direction of the joining surface of the thin plate-like member with another thin plate-like member, and this groove is formed to have a length such that at least one of its both ends does not reach the edge of the thin plate-like member. With this configuration, it is said that excess adhesives and residual air bubbles between the thin plate-like members can be efficiently released, and warpage can be prevented and the rigidity of the thin plate-like member can be ensured.

[0005] Also, a droplet discharge head is known in which a pressure liquid chamber pattern is formed on the pressure liquid chamber forming surface of a pressure liquid chamber forming member, and a dummy pattern is formed on the opposing surface parallel to the longitudinal direction of the pressure liquid chamber pattern and in a staggered pattern with respect to the dummy pattern adjacent to it in the short side direction of the pressure liquid chamber pattern (see, for example, "Patent Document 2"). According to this configuration, a framework structure is formed on the nozzle surface to increase the rigidity of the pressure liquid chamber, and warpage generated in the pressure liquid chamber forming member due to the processing difference between the front and back of the pressure liquid chamber forming member and the internal stress of the liquid-resistant film can be reduced, and the assembly accuracy of the droplet discharge head can be improved to obtain a highly reliable droplet discharge head.

[0006] Also, a droplet discharge device is known in which a reinforcing layer is provided at a position corresponding to a flow path partition wall on a diaphragm, and the width of the lower surface of the reinforcing layer on the diaphragm side is formed wider than the width of the upper part of the reinforcing layer (see, for example, "Patent Document 3"). According to this configuration, in view of the problem of suppressing variations in discharge performance and achieving high image quality by optimizing the structure in the droplet discharge device, it is said that the occurrence of ink droplet discharge failure due to poor diaphragm driving can be prevented and stable ink discharge characteristics can be obtained, and the image quality can be improved.

Summary of the Invention

Problems to be Solved by the Invention

[0007] Conventional droplet ejection heads have problems such as fluid leakage, wiring breakage, and changes in flow path volume due to external forces acting from the outer periphery of the component, and if the adhesive at the bonding interface overflows, the overflowing adhesive may interfere with adjacent heads. Therefore, it is desirable to minimize shape changes due to external forces and to prevent the overflow of adhesive. However, the above-mentioned conventional technology does not solve the problems of chipping, cracking, etc. due to the load of external forces acting on the outer periphery of the component, and the problem of adhesive overflowing to the outer periphery of the component. SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a droplet ejection head that can solve the above-mentioned problems, and that can suppress the occurrence of chipping and cracking due to external forces and can also suppress the overflow of adhesive. [Means for solving the problem]

[0008] The invention described in claim 1 comprises a nozzle plate having a plurality of nozzles for ejecting droplets, a flow path substrate to which the nozzle plate is joined and in which a plurality of individual flow paths are formed, separated by partitions and each communicating with the nozzles individually, and a piezoelectric element holding substrate joined to the side of the flow path substrate opposite the nozzle plate, wherein an outer wall of an end partition, which is the partition located at an end portion on one side of the flow path substrate, is located inside the outer wall of the end portion on the one side of the piezoelectric element holding substrate. Effect of the Invention

[0009] According to the present invention, the outer wall of the flow path substrate is positioned inside the outer wall of the droplet ejection head, preventing the outer wall of the flow path substrate from being directly subjected to external forces, thereby making it possible to provide a droplet ejection head that can suppress the occurrence of chipping or cracking due to external forces and also suppress the overflow of adhesive. [Brief description of the drawings]

[0010]

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Embodiments for Carrying Out the Invention

[0011] FIG. 1 shows a schematic exploded perspective view of a conventionally well-known droplet discharge unit 100 to which an embodiment of the present invention is applicable, and FIG. 2 shows a schematic cross-sectional view along the short side direction of the droplet recording head of the droplet discharge unit 100. In the figure, the droplet discharge unit 100 includes a plurality of droplet discharge heads 101 that discharge droplets, a base member 102 that holds the plurality of droplet discharge heads 101, and a cover member 103 that serves as a nozzle cover for the droplet discharge heads 101. Further, the droplet discharge unit 100 includes a heat dissipation member 104, a manifold 105 that forms a flow path for supplying liquid to the plurality of droplet discharge heads 101, a printed circuit board (PCB) 106 connected to a flexible wiring member 90 including a driver IC (drive circuit) 91, and a module case 107.

[0012] The plurality of droplet discharge heads 101 include a nozzle plate 10 in which a plurality of nozzles 11 are formed, a flow path substrate 20 in which individual liquid chambers 21 and the like, which are pressure chambers communicating with the nozzles 11, are formed, a diaphragm 30 including a piezoelectric element 40, a piezoelectric element holding substrate 50 laminated on the diaphragm 30, a common flow path member (frame member) 70 laminated on the piezoelectric element holding substrate 50, and the like. The nozzle plate 10 uses a single crystal silicon wafer as a substrate material, and the flow path substrate 20 forms a supply side individual flow path 22 communicating with the individual liquid chambers 21 and a recovery side individual flow path 24 communicating with the individual liquid chambers 21, together with the individual liquid chambers 21 which are individual flow paths communicating with the respective nozzles 11. The piezoelectric element holding substrate 50 uses a single crystal silicon wafer as the substrate material, and forms a supply-side intermediate individual flow path 51 that communicates with the supply-side individual flow path 22 through the opening 31 of the diaphragm 30, and a recovery-side intermediate individual flow path 52 that communicates with the recovery-side individual flow path 24 through the opening 32 of the diaphragm 30. Further, as shown in FIG. 3, a recess 50a for accommodating the piezoelectric element 40 is formed in the piezoelectric element holding substrate 50.

[0013] The piezoelectric element holding substrate 50 and the common flow path member 70 form a supply-side common flow path 71 that communicates with the supply-side intermediate individual flow path 51, and a recovery-side common flow path 72 that communicates with the recovery-side intermediate individual flow path 52. The supply-side common flow path 71 communicates with the supply port 81 through the flow path 151 of the manifold 105, and the recovery-side common flow path 72 communicates with the recovery port 82 through the flow path 152 of the manifold 105. The printed circuit board 106 and the piezoelectric element 40 are connected via a flexible wiring member 90, and a driver IC 91 is mounted on the flexible wiring member 90.

[0014] In the present embodiment, the plurality of droplet discharge heads 101 are attached to the base member 102 at predetermined intervals. The attachment of the droplet discharge head 101 to the base member 102 is achieved by inserting the droplet discharge head 101 into the opening 121 provided in the base member 102, and joining and fixing the peripheral edge of the nozzle plate 10 constituting the droplet discharge head 101 to the cover member 103 joined and fixed to the base member 102. In addition, a flange portion (not shown) provided outside the common flow path member 70 of the droplet discharge head 101 is joined and fixed to the base member 102. Note that the fixing structure between the droplet discharge head 101 and the base member 102 is not limited to the above-described configuration, and any configuration such as adhesion, caulking, or screw fixing may be adopted.

[0015] In the present embodiment, it is preferable that the base member 102 is formed of a material having a low coefficient of linear expansion. Examples of the material having a low coefficient of linear expansion include 42alloy (alloy) obtained by adding nickel to iron and invar material. In the present embodiment, an invar material is used. With this configuration, even if the droplet ejection head 101 generates heat and the temperature of the base member 102 rises, the amount of expansion of the base member 102 is small, so that displacement of the nozzle from a predetermined nozzle position hardly occurs, and generation of displacement of the landing position of the droplet can be suppressed. Similarly, the nozzle plate 10, the flow path substrate 20, and the diaphragm 30 are each formed of a single crystal silicon substrate, and the linear expansion coefficient is made substantially the same as that of the base member 102. Thereby, generation of nozzle displacement due to thermal expansion can be reduced.

[0016] FIG. 3 shows a schematic cross-sectional view between the flow path substrate 20 and the common flow path member 70 in a conventional droplet ejection head 101. In FIG. 3, the common flow path member 70 has a damper 74 for attenuating liquid impact and vibration below it. The damper 74 is preferably made of a metal thin film or an inorganic thin film that is resistant to organic solvents, and its thickness is preferably 10 μm or less. One surface of the damper 74 is joined to a damper holding substrate 73 made of a single crystal silicon wafer as a substrate material via an adhesive 76, and the other surface is joined to a piezoelectric element holding substrate 50 via an adhesive 75. As the adhesive 75, an adhesive optimal for joining the damper 74 and the piezoelectric element holding substrate 50, and as the adhesive 76, an adhesive optimal for joining the damper 74 and the damper holding substrate 73 are respectively selected. As the adhesives 75 and 76, for example, those made of a thermosetting resin are used. Note that the damper holding substrate 73 and the damper 74 may be manufactured using a semiconductor process. In this case, a material for the damper 74 is formed on a wafer serving as a base material, and the film formation surface is joined to a damper holding substrate 73 in which a space where the damper 74 can vibrate is patterned.

[0017] The piezoelectric element holding substrate 50 has a partition wall 59 as a first partition wall that separates and forms a supply side common flow path 71 and a recovery side common flow path 72 as spaces on the other side where the damper 74 can vibrate. The piezoelectric element holding substrate 50 also has side walls 55 formed at both end portions in FIG. 3 with the same width as the partition wall 59. The damper holding substrate 73 has a partition wall 69 as a second partition wall that forms a space 67 where the damper 74 can vibrate, formed to face the supply-side common flow path 71, and a space 68 where the damper 74 can vibrate, formed to face the recovery-side common flow path 72, and isolates them. Further, the damper holding substrate 73 has side walls 65 formed at both side ends in FIG. 3 with the same width as the partition wall 69, respectively. One surface of the damper 74 is joined to each of the side walls 65 and the partition wall 69 by an adhesive 76, and the other surface of the damper 74 is joined to each of the side walls 55 and the partition wall 59 by an adhesive 75.

[0018] FIG. 4(a) shows a schematic perspective view of the droplet discharge head 101 with the nozzle plate 10 on the lower side, FIG. 4(b) shows a schematic plan view of the nozzle plate 10 as viewed from the lower surface side, and FIG. 4(c) shows a schematic plan view of the flow path substrate 20 as viewed from the lower surface side. In the configuration shown in FIG. 4, a plurality of nozzles 11 are regularly arranged on the nozzle plate 10, and a plurality of individual liquid chambers 21 are respectively formed at positions corresponding to the nozzles 11 of the flow path substrate 20. In the conventional configuration shown in FIG. 4, an adhesive 77 is applied to the hatched portion of the flow path substrate 20, and the flow path substrate 20 and the nozzle plate 10 are adhesively fixed.

[0019] FIG. 5 shows a cross-sectional view taken along the line A-A in FIG. 4(b). As shown in FIG. 5, since the outer walls of the nozzle plate 10 and the flow path substrate 20 located outside the droplet discharge head 101 form the same plane, when an external force acts, the flow path substrate 20 may be deformed or damaged, resulting in problems such as fluid leakage, disconnection of wiring, and change in flow path volume, and the desired function cannot be obtained. Further, when joining the nozzle plate 10 and the flow path substrate 20, as described above, an adhesive 77 is applied between the members, and the adhesive 77 is heated and cured while pressing the members from above and below. However, there is a problem that the adhesive 77 oozes out to the outside between the nozzle plate 10 and the flow path substrate 20 during pressurization, and the oozed adhesive 77 interferes with other adjacent droplet discharge heads. Hereinafter, the configuration of the present invention for preventing the occurrence of this problem will be described.

[0020] Fig. 6(a) is a schematic perspective view of the nozzle plate 10 of the droplet discharge head 1 according to the first embodiment of the present invention with the lower side, Fig. 6(b) is a schematic plan view of the nozzle plate 10 seen from the lower surface side, Fig. 6(c) is a schematic plan view of the flow path substrate 23 seen from the lower surface side, and Fig. 7 is a cross-sectional view taken along the line B-B in Fig. 6(b). The droplet discharge head 1 is different only in that it has a flow path substrate 23 instead of the flow path substrate 20 compared with the above-described droplet discharge head 101, and other configurations are the same.

[0021] As shown in Fig. 7, the flow path substrate 23 has a plurality of partition walls that form a plurality of individual liquid chambers 21 that are individual flow paths. Each partition wall has a partition wall 23a located other than one end in the longitudinal direction in Fig. 6(a) and an end partition wall 23b located at one end. The end partition wall 23b is formed such that its outer wall is located inside the outer wall at one end of the piezoelectric element holding substrate 50, and a recess 25 is formed between the nozzle plate 10 and the piezoelectric element holding substrate 50 together with the diaphragm 30.

[0022] According to the droplet discharge head 1 of the present invention with this configuration, since it has the recess 25, the outer wall of the flow path substrate 23 is located inside the outer wall of the droplet discharge head 1, and the outer wall of the flow path substrate 23 is prevented from directly receiving an external force. Thereby, it is possible to prevent problems such as deformation or breakage of the flow path substrate 23, resulting in fluid leakage, disconnection of wiring, change in flow path volume, etc., and inability to obtain a desired function. Further, when the flow path substrate 23 and the piezoelectric element holding substrate 50 are pressure-bonded via the diaphragm 30, the adhesive 77 that has oozed out during pressurization stays in the recess 25, so that it is possible to prevent the problem that the oozed adhesive 77 interferes with other adjacent droplet discharge heads.

[0023] In the droplet ejection head 1, as shown in FIG. 7, the flow path substrate 23 is formed such that the width D of the end partition wall 23b is larger than the width C of the partition wall 23a. By configuring in this way, it is possible to suppress the occurrence of crosstalk during droplet ejection, suppress variations in ejection performance, and achieve high image quality. Also, in the droplet ejection head 1, the distance E between the outer wall at one end of the piezoelectric element holding substrate 50 and the outer wall of the end outer wall 23b is formed to be equal to or greater than the width D of the end partition wall 23b. By configuring in this way, it is possible to secure the distance to the individual liquid chambers 21 which are individual flow paths, and suppress the risk of fluid leakage when chips or cracks occur in the end partition wall 23b due to external force.

[0024] FIG. 8(a) shows a schematic perspective view of the nozzle plate 10 of the droplet ejection head 2 according to the second embodiment of the present invention with the lower side, FIG. 8(b) shows a schematic plan view of the nozzle plate 10 viewed from the lower surface side, and FIG. 8(c) shows a schematic plan view of the flow path substrate 26 viewed from the lower surface side. The droplet ejection head 2 is different from the droplet ejection head 1 in that the flow path substrate 26 is used instead of the flow path substrate 23, and other configurations are the same. The flow path substrate 26 has, similarly to the flow path substrate 23, a partition wall located other than one end and an end partition wall located at one end. The end partition wall is formed such that its outer wall is located inside the outer wall at one end of the piezoelectric element holding substrate 50, and forms a recess 27 between the nozzle plate 10 and the piezoelectric element holding substrate 50 together with the diaphragm 30.

[0025] The recess 27 is formed between the nozzle plate 10 and the piezoelectric element holding substrate 50 together with the diaphragm 30, similarly to the recess 25, and is not formed near both ends on the other side which is the short side direction of the flow path substrate 26 and intersects the one side described above. Also, the adhesive 77 is not applied to the portions near both ends on the other side of the flow path substrate 26. In this second embodiment, the outer wall of one end portion of the flow path substrate 26 is located at the same position as the outer wall of one end portion of the piezoelectric element holding substrate 50 at a portion other than the end partition wall. In other words, the recess 27 is formed only at a portion corresponding to this outer wall on the outer wall of one end portion of the flow path substrate 26. With this configuration, by forming the recess, it is possible to limit the portion where the thickness of the outer periphery is reduced and the structure becomes weak, and it is possible to suppress the progress of chipping and cracking to the individual liquid chambers 21 while maintaining the strength, and it is possible to suppress the protrusion of the adhesive 77 applied around the individual liquid chambers 21.

[0026] Next, a comparative test of each of the above-described droplet discharge heads 1, 2, and 101 was performed. The comparative test was conducted for evaluating chipping and cracking of the flow path and for evaluating the protrusion of the adhesive. In the evaluation of chipping and cracking of the flow path, when the assembly process of the droplet discharge head including the outer periphery abutment was performed with the configuration of each droplet discharge head, it was evaluated whether chipping and cracking reached the flow path from the outer periphery. The state of reaching of chipping and cracking to the flow path was confirmed by observing with an IR microscope. The evaluation results are shown in FIG. 9. The occurrence rate of chipping and cracking of the flow path was lower for the droplet discharge heads 1 and 2 than for the droplet discharge head 101. This is because in the conventional droplet discharge head 101, chipping occurred on the outer periphery due to a load applied from the outer periphery, and the generated chipping extended to the inside of the substrate, whereas in the droplet discharge heads 1 and 2, since the recesses 25 and 27 were provided, an external force hardly acts on the outer periphery, and even when chipping occurred on the outer periphery, the extension of the chipping stopped and the chipping did not reach the flow path.

[0027] In the evaluation of the protrusion of the adhesive, when the assembly process of the droplet discharge head including the bonding process using the adhesive was performed with the configuration of each droplet discharge head, it was evaluated whether the adhesive protruded from the outer periphery of the substrate. The evaluation results are shown in FIG. 9. The occurrence rate of the adhesive oozing out to the outer periphery of the substrate was lower for the droplet discharge heads 1 and 2 than for the droplet discharge head 101. This is because, with the conventional droplet discharge head 101, the adhesive was applied up to the outer periphery of the substrate, so the adhesive oozed out due to the pressure during bonding. In contrast, with the droplet discharge heads 1 and 2, the recesses 25 and 27 were provided, so the oozed adhesive remained in the recesses 25 and 27 and did not ooze out to the outer periphery of the substrate.

[0028] From the above results, it can be said that the droplet discharge heads 1 and 2 of the present invention are superior to the conventional droplet discharge head 101 in terms of the occurrence of chipping or roughening of the flow path due to the load of external force from the outer periphery of the substrate and the oozing out of the adhesive. In the droplet discharge head 1, although there were no cracks or chips reaching the flow path, a situation where the outer periphery was chipped at multiple locations was observed. Therefore, considering the influence of the generation of foreign matter due to chipping, it is desirable to have a configuration like the droplet discharge head 2, where a recess 27 is partially provided with respect to the outer periphery of the substrate to prevent accidental chipping and cracking.

[0029] Next, a droplet discharge device equipped with each of the above-described droplet discharge heads 1 and 2 will be described. As shown in FIGS. 10 and 11, a printing device 500, which is a droplet discharge device, includes a loading means 501 for loading a continuous body 510, which is a recording medium, and a guiding and transporting means 503 for guiding and transporting the continuous body 510 loaded by the loading means 501 toward a printing means 505. The printing device 500 also includes a printing means 505 for performing a printing operation of discharging droplets onto the continuous body 510 to form an image, a drying means 507 for drying the continuous body 510 to which droplets have adhered, an unloading means 509 for unloading the continuous body 510, and the like. The continuous medium 510 is sent out from the supply reel roller 511 of the supply means 501, and is guided and conveyed by the rollers respectively provided in the supply means 501, the guiding and conveying means 503, the drying means 507, and the discharging means 509, and is wound around the take-up roller 591 of the discharging means 509. The continuous medium 510 is conveyed on the conveyance guide member 559 in the printing means 505 so as to face the head unit 550 which is a droplet discharge unit, and an image is printed by the droplets discharged from the head unit 550.

[0030] The printing apparatus 500 includes droplet discharge units 100A and 100B similar to the above-described droplet discharge unit 100 in the head unit 550, and each of the droplet discharge units 100A and 100B is provided on a common base member 552. When the arrangement direction of the droplet discharge heads 1 in the direction orthogonal to the continuous medium conveyance direction is defined as the head arrangement direction, each of the droplet discharge units 100A and 100B discharges droplets of the same color in the sets of the head rows 1A1 and 1A2 of the droplet discharge unit 100A. Similarly, droplets of a desired color are discharged in the sets of the head rows 1B1 and 1B2 of the droplet discharge unit 100A, the sets of the head rows 1C1 and 1C2 of the droplet discharge unit 100B, and the sets of the head rows 1D1 and 1D2 of the droplet discharge unit 100B.

[0031] Next, another example of the printing apparatus which is a droplet discharge apparatus according to the present invention will be described with reference to FIGS. 12 and 13. The printing apparatus 400 as a droplet discharge apparatus is a serial type printing apparatus, and the carriage 403 reciprocates in the main scanning direction by the 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, and the like. The guide member 401 is stretched between the left and right side plates 491A and 491B, and holds the carriage 403 movably. The carriage 403 is reciprocated in the main scanning direction by transmitting the driving force of the main scanning motor 405 via a timing belt 408 stretched between a driving pulley 406 and a driven pulley 407.

[0032] The carriage 403 is equipped with a droplet ejection unit 440 that integrally has a droplet ejection head 1 and a head tank 441. Here, the droplet ejection head 1 ejects droplets of each color such as yellow (Y), cyan (C), magenta (M), and black (K). Further, the droplet ejection head 1 is arranged with a nozzle row composed of a plurality of nozzles in a sub-scanning direction orthogonal to the main scanning direction, and is mounted with the droplet ejection direction facing downward. The droplet ejection head 1 is connected to a liquid circulation device (not shown), and a liquid of a desired color is circulated and supplied to the droplet ejection head 1.

[0033] The printing apparatus 400 includes a conveyance mechanism 495 that conveys a sheet 410 which is a recording medium. The conveyance mechanism 495 has a conveyance belt 412 which is a conveyance means, and a sub-scanning motor 416 that drives the conveyance belt 412. The endless conveyance belt 412 is stretched between a conveyance roller 413 and a tension roller 414, and adsorbs the sheet 410 and conveys it to a position facing the droplet ejection head 1. The adsorption is performed by electrostatic adsorption or air suction or the like. The conveyance belt 412 is circulated and moved in the sub-scanning direction by transmitting the driving force of the sub-scanning motor 416 via a timing belt 417 and a timing pulley 418.

[0034] On one side of the carriage 403 in the main scanning direction and on the side of the conveyance belt 412, a maintenance and recovery mechanism 420 for maintaining and recovering the droplet ejection head 1 is arranged. The maintenance and recovery mechanism 420 is composed of, for example, a cap member 421 that caps the nozzle surface of the droplet ejection head 1, a wiper member 422 that wipes the nozzle surface, and the like. Further, the main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the conveyance mechanism 495 are attached to a housing including side plates 491A, 491B, and a back plate 491C. In the printing apparatus 400 having the above-described configuration, the sheet 410 is adsorbed by the conveyance belt 412, and the sheet 410 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 412. At this time, by driving the droplet ejection head 1 in accordance with an image signal while moving the carriage 403 in the main scanning direction, droplets are ejected onto the stopped sheet 410 to form an image.

[0035] Next, the droplet discharge unit 440 described above will be described with reference to FIG. 14. The droplet discharge unit 440 includes a housing portion composed of side plates 491A and 491B and a back plate 491C among the members constituting the printing apparatus 400 which is a droplet discharge apparatus, and a main scanning movement mechanism 493, a carriage 403, a droplet discharge head 1, and the like. Note that it is also possible to configure a droplet discharge unit in which the maintenance and recovery mechanism 420 described above is further attached to, for example, the side plate 491B of the droplet discharge unit 440.

[0036] Next, another example of the droplet discharge unit according to an embodiment of the present invention will be described with reference to FIG. 15. The droplet discharge unit 450 shown in FIG. 15 includes a droplet discharge head 1 to which a flow path component 444 is attached, and a tube 456 connected to the flow path component 444. The flow path component 444 is disposed inside a cover 442, and a connector 443 for making an electrical connection with the droplet discharge head 1 is provided above the flow path component 444. Note that a configuration including a head tank 441 instead of the flow path component 444 is also possible.

[0037] In the droplet discharge units 100, 100A, 100B, 440, 450, 550, and the printing apparatuses 400 and 500 which are droplet discharge apparatuses, including the droplet discharge head 1 described above, the same effects as those of the droplet discharge head 1 described above can be obtained. In addition, although the configuration using the droplet discharge head 1 as the droplet discharge head is shown in each of the above configurations, it is also possible to use the droplet discharge head 2 instead of the droplet discharge head 1. In this case, the same effects as those of each droplet discharge head 2 can be obtained.

[0038] In the present invention, the liquid to be used may be any liquid having a viscosity and surface tension that can be discharged from the droplet discharge head, and its properties are not particularly limited. However, it is preferably a liquid that has a viscosity of 30 mPa·s or less at normal temperature and pressure, or by heating or cooling. More specifically, examples include solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functional additive materials such as surfactants, biocompatible materials such as DNA, amino acids, proteins, and calcium, edible materials such as natural pigments, and solutions, suspensions, emulsions, etc. containing these. These can be used, for example, in applications such as inkjet inks, surface treatment liquids, and material liquids for three-dimensional modeling. As the energy generation source for discharging droplets, those using piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators using electrothermal conversion elements such as heating resistors, electrostatic actuators composed of a diaphragm and a counter electrode, etc. are included.

[0039] The "droplet discharge head" is not limited by the pressure generation means used. For example, in addition to the piezoelectric actuators as described above (which may use laminated piezoelectric elements), those using thermal actuators with electrothermal conversion elements such as heating resistors, electrostatic actuators composed of a diaphragm and a counter electrode, etc. may also be used. The "droplet discharge unit" is an integrated unit of a droplet discharge head with functional components and mechanisms, and includes an assembly of components related to droplet discharge. For example, the "droplet discharge unit" includes combinations of at least one of the configurations of a head tank, carriage, supply mechanism, maintenance and recovery mechanism, main scanning movement mechanism, and liquid circulation device with the droplet discharge head. Here, integration includes, for example, cases where the droplet discharge head and functional components or mechanisms are fixed to each other by fastening, adhesion, engagement, etc., and cases where one is movably held with respect to the other. Also, the droplet discharge head and functional components or mechanisms may be detachable from each other.

[0040] As the droplet ejection unit, there is one in which a droplet ejection head and a head tank are integrated, and there is one in which both are connected to each other by a tube or the like and integrated. Here, it is also possible to add a unit including a filter between the droplet ejection head and the head tank of these droplet ejection units. Also, as the droplet ejection unit, there is one in which a droplet ejection head and a carriage are integrated, and there is one in which a droplet ejection head, a carriage, and a main scanning movement mechanism are integrated. Also, as the droplet ejection unit, there is one in which a droplet ejection head is movably held by a guide member that constitutes a part of the scanning movement mechanism, and the droplet ejection head and the scanning movement mechanism are integrated.

[0041] As the droplet ejection unit, there is one in which a cap member that is a part of the maintenance and recovery mechanism is fixed to a carriage to which a droplet ejection head is attached, and the droplet ejection head, the carriage, and the maintenance and recovery mechanism are integrated. Also, as the droplet ejection unit, there is one in which a tube is connected to a droplet ejection head to which a head tank or a flow path component is attached, and the droplet ejection head and the supply mechanism are integrated. Through this tube, the liquid from the liquid storage source is supplied to the droplet ejection head. The main scanning movement mechanism shall include a single guide member. The supply mechanism shall include a single tube and a single loading unit.

[0042] In the present invention, the droplet ejection unit is described in combination with the droplet ejection head. However, the droplet ejection unit includes not only a head module or a head unit including the above-described droplet ejection head but also those in which the above-described functional components and mechanisms are integrated. The droplet ejection device includes a droplet ejection head, a droplet ejection unit, a head module, a head unit, etc., and includes a droplet ejection device that drives the droplet ejection head to eject droplets. The droplet ejection device includes not only a device capable of ejecting droplets onto an object to which droplets can adhere but also a device capable of ejecting droplets into the air or into a liquid.

[0043] The droplet ejection device can also include means related to the feeding, conveying, and paper discharging of objects to which droplets can adhere, as well as other pretreatment devices, post-treatment devices, etc. For example, as droplet ejection devices, there are image forming devices that eject ink to form an image on a recording medium, and three-dimensional modeling devices (3D modeling devices) that eject a modeling liquid onto a powder layer formed by layering powder in order to model a three-dimensional object (3D object). Also, the droplet ejection device is not limited to those in which a meaningful image such as characters or figures is visualized by the ejected droplets. For example, those that form a pattern that has no meaning by itself, and those that model a three-dimensional image are also included.

[0044] The objects to which the above-mentioned droplets can adhere mean those to which droplets can adhere at least temporarily, such as those that adhere and stick, those that adhere and penetrate, etc. Specific examples include recording media such as paper, film, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, media such as test cells, and all objects to which droplets adhere are included unless otherwise particularly limited. The material of the object to which droplets can adhere can be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc., as long as droplets can adhere even temporarily, it can be of any material.

[0045] The droplet ejection device includes a configuration in which the droplet ejection head and the object to which droplets can adhere move relative to each other, but the object to move is not limited to either one. Specific examples include both serial type devices that move the droplet ejection head and line type devices that do not move the droplet ejection head. Also, as other droplet ejection devices, there are treatment liquid coating devices that eject a treatment liquid onto the surface of paper in order to coat the surface of the paper for the purpose of modifying the surface of the paper, and injection granulation devices that inject a composition liquid in which raw materials are dispersed in a solution through a nozzle to granulate fine particles of the raw materials.

[0046] The droplet ejection device of the present invention also includes a manufacturing device for electrodes and electrochemical elements. Hereinafter, the manufacturing device for electrodes will be described. FIG. 16 is a schematic diagram showing an example of a manufacturing device for electrodes according to an embodiment of the present invention. The electrode manufacturing device 700 is a device that manufactures an electrode including a layer having an electrode material by ejecting a liquid composition using a droplet ejection unit including a droplet ejection head. First, the forming means and forming process of the layer containing the electrode material will be described. The droplet ejection means included in the electrode manufacturing device 700 shown in FIG. 16 is the above-described droplet ejection unit of the present invention. By ejecting the liquid composition from the droplet ejection head included in the droplet ejection unit, the liquid composition is applied onto the object, and a liquid composition layer is formed. The object (hereinafter, may be referred to as the "ejection object") is not particularly limited as long as it is an object on which a layer containing the electrode material is to be formed, and can be appropriately selected according to the purpose. For example, examples of the object include an electrode substrate (current collector), an active material layer, a layer containing a solid electrode material, etc. Further, the object may be an electrode composite layer containing an active material on the electrode substrate. Also, as long as the ejection means and ejection process can form a layer having an electrode material with respect to the ejection object, the means and process for forming a layer having an electrode material by directly ejecting the liquid composition may be used. Furthermore, the ejection means and ejection process may be means and processes for forming a layer having an electrode material by indirectly ejecting the liquid composition.

[0047] Next, other configurations and processes will be described. The other configurations included in the manufacturing device for the electrode composite layer are not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. Also, the other processes included in the manufacturing method for the electrode composite layer are not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. For example, examples of the configurations and processes included in the manufacturing device and manufacturing method for the electrode composite layer include heating means and heating processes.

[0048] Next, the heating means and heating process will be described. The heating means included in the manufacturing apparatus for the electrode composite material layer is a means for heating the liquid composition discharged by the discharging means. Further, the heating step included in the manufacturing method of the electrode composite material layer is a step for heating the liquid composition discharged in the discharging step. By heating the liquid composition, the liquid composition can be dried.

[0049] Next, a configuration for forming a layer containing an electrode material by directly discharging a liquid composition will be described. Here, as an example of an electrode manufacturing apparatus having a configuration for forming a layer containing an electrode material, an electrode manufacturing apparatus for forming an electrode composite material layer containing an active material on an electrode substrate (current collector) will be described. As shown in FIG. 16, the electrode manufacturing apparatus 700 includes a discharge process section 110 including a step of applying a liquid composition onto a printing substrate 704 having a discharge object to form a liquid composition layer, and a heating process section 130 including a heating step of heating the liquid composition to obtain an electrode composite material layer.

[0050] The electrode manufacturing apparatus 700 includes a transport means 705 for transporting the printing substrate 704, and the transport means 705 transports the printing substrate 704 at a preset speed in the order of the discharge process section 110 and the heating process section 130. There is no particular limitation on the manufacturing method of the printing substrate 704 having a discharge object such as an active material layer, and a well-known method can be appropriately selected. The discharge process section 110 includes a droplet discharge head 281a for realizing a step of applying a liquid composition onto the printing substrate 704, a storage container 281b for storing the liquid composition 707, a supply tube 281c for supplying the liquid composition 707 in the storage container 281b to the droplet discharge head 281a, and the like.

[0051] In the discharge process section 110, the liquid composition 707 is discharged from the droplet discharge head 281a, and the liquid composition 707 is applied onto the printing substrate 704 to form a liquid composition layer in a thin film shape. Note that the storage container 281b may be configured to be integrated with the manufacturing apparatus for the electrode composite material layer, or may be configured to be removable from the manufacturing apparatus for the electrode composite material layer. Further, the storage container 281b may be a storage container integrated with the manufacturing apparatus for the electrode composite material layer, or a container used for adding to a storage container that is removable from the manufacturing apparatus for the electrode composite material layer. 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.

[0052] In the heating engineering section 130, a solvent removal step is performed to heat and remove the solvent remaining in the liquid composition layer. Specifically, the solvent remaining in the liquid composition layer is dried by heating with the heating device 703 provided in the heating engineering section 130 and removed from the liquid composition layer, thereby forming the electrode binder layer. Further, the solvent removal step in the heating engineering section 130 may be performed under reduced pressure. There is no particular limitation on the heating device 703, and it can be appropriately selected according to the purpose. For example, the heating device 703 includes substrate heating, an IR heater, a hot air heater, etc. Further, the heating device 703 may be a combination of at least two of substrate heating, an IR heater, and a hot air heater. Regarding the heating temperature and heating time, they can be appropriately selected according to the boiling point of the solvent contained in the liquid composition 707 or the formed film thickness.

[0053] In the electrode manufacturing apparatus 700, the same droplet discharge head 1 or droplet discharge head 2 as described above is used as the droplet discharge head 281a. By using the electrode manufacturing apparatus 700 according to the embodiment of the present invention, the liquid composition can be discharged to the target position of the discharge object. The electrode binder layer can be suitably used, for example, as a part of the configuration of an electrochemical element. There is no particular limitation on the configuration other than the electrode binder layer in the electrochemical element, and well-known ones can be appropriately selected. Examples of the configuration other than the electrode binder layer include a positive electrode, a negative electrode, a separator, etc.

[0054] Aspects of the present invention are as follows, for example. [1] A nozzle plate having a plurality of nozzles for discharging droplets, a flow path substrate to which the nozzle plate is joined and in which a plurality of individual flow paths are formed, which are partitioned by partition walls and communicate individually with the nozzles, and a piezoelectric element holding substrate joined to the opposite side of the flow path substrate from the nozzle plate. The outer wall of the end partition wall, which is the partition wall located at one end of the flow path substrate, is a droplet discharge head located inside the outer wall of one end of the piezoelectric element holding substrate. [2] The droplet discharge head according to [1], wherein the width of the end partition wall is equal to or greater than the width of the other partition walls of the flow path substrate that form the plurality of individual flow paths. [3] The droplet discharge head according to [1] or [2], wherein the distance between the outer wall of one end of the piezoelectric element holding substrate and the outer wall of the end partition wall is equal to or greater than the width of the end partition wall. [4] The droplet discharge head according to any one of [1] to [3], wherein the outer wall of one end of the flow path substrate has other parts located at the same position as the outer wall of one end of the piezoelectric element holding substrate except for the end partition wall. [5] A droplet discharge unit having the droplet discharge head according to any one of [1] to [4]. [6] A droplet discharge device having the droplet discharge unit according to [5]. [7] A droplet discharge device having the droplet discharge head according to any one of [1] to [4].

[0055] As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims, unless otherwise particularly limited in the above description. The effects described in the embodiments of the present invention are merely examples of the most suitable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention.

Explanation of reference numerals

[0056] 1,2 Droplet ejection head 10 Nozzle plate 11 Nozzle 21 Individual flow paths (individual liquid chambers) 23,26 Flow path substrate 23a Partition wall 23b End partition wall 50 Piezoelectric element holding substrate 100A, 100B, 440, 450, 550 Droplet ejection unit 400, 500 Droplet ejection device (printing device) 700 Droplet ejection device (electrode manufacturing device)

Prior art documents

Patent documents

[0057]

Patent Document 1

Patent Document 2

Patent Document 3

Claims

1. A nozzle plate having a plurality of nozzles for discharging droplets, a flow path substrate to which the nozzle plate is joined and in which a plurality of individual flow paths are formed, which are partitioned by partition walls and communicate individually with the nozzles, and a piezoelectric element holding substrate joined to the side of the flow path substrate opposite to the nozzle plate, wherein an outer wall of an end partition wall, which is the partition wall located at one end of the flow path substrate, is located inside an outer wall of one end of the piezoelectric element holding substrate, and the droplet discharge head is provided.

2. In the droplet discharge head according to Claim 1, the width of the end partition wall is equal to or greater than the width of the other partition walls of the flow path substrate that form the plurality of individual flow paths, and the droplet discharge head is characterized by this.

3. In the droplet discharge head according to Claim 1, the distance between the outer wall of one end of the piezoelectric element holding substrate and the outer wall of the end partition wall is equal to or greater than the width of the end partition wall, and the droplet discharge head is characterized by this.

4. In the droplet discharge head according to Claim 1, the outer wall of one end of the flow path substrate is located at the same position as the outer wall of one end of the piezoelectric element holding substrate in a part other than the end partition wall, and the droplet discharge head is characterized by this.

5. A droplet discharge unit, characterized by having the droplet discharge head according to any one of Claims 1 to 4.

6. A droplet discharge device, characterized by having the droplet discharge unit according to Claim 5.

7. A droplet discharge device, characterized by having the droplet discharge head according to any one of Claims 1 to 4.

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