Liquid ejection head and liquid ejection apparatus

Abstract

To provide a liquid jet head which can supply a liquid sufficiently heated by a heater to a head chip and eliminates a need of heating the head chip by using a holder formed of a material having high heat conductivity to simplify a structure, and to provide a liquid jet device.SOLUTION: A liquid jet head includes: a plurality of head chips 10 having a nozzle plate having a plurality of nozzles which jet a liquid in a first direction +Z and a case 13 formed with one or more first passages communicating with at least part of the plurality of nozzles; a holder 40 to which the plurality of head chips 10 are fixed and which is formed including a metal or a ceramic and has a plurality of second passages 50 communicating with at least one of the plurality of first passages; and a heater 70 which heats the holder 40.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head and a liquid ejection apparatus that eject liquid from nozzles, and more particularly to an ink jet recording head and an ink jet recording apparatus that eject ink as the liquid. [Background technology]

[0002] 2. Description of the Related Art A liquid ejecting apparatus, typified by an ink jet recording apparatus such as an ink jet printer or a plotter, includes a liquid ejecting head capable of ejecting liquid such as ink stored in a cartridge, a tank or the like in the form of droplets.

[0003] The liquid ejecting head includes a head chip provided with nozzles for ejecting liquid, and a holder for holding a plurality of head chips.

[0004] The liquid ejected from such a liquid ejection head has a suitable viscosity depending on the type of liquid. The viscosity of a liquid is correlated with temperature, so that the lower the viscosity, the higher the viscosity, and the higher the temperature, the lower the viscosity. Therefore, when a liquid ejection head designed to suit the viscosity of a liquid that is normally used is placed in a low-temperature environment or when ejecting a highly viscous liquid, it is necessary to heat the liquid. Configurations in which a heater is provided in a liquid ejection head to heat the liquid have been disclosed (see, for example, Patent Documents 1 and 2).

[0005] Specifically, Patent Document 1 discloses a configuration having a first heater provided in a frame that holds multiple flow path modules, a second heater provided in a second tank that supplies liquid, and a connection portion that connects the flow path modules and the second tank.

[0006] Moreover, Patent Document 2 discloses a configuration in which heaters are provided for heating each of the head chip cases. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2016-97568 A [Patent Document 2] JP 2019-155839 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, in Patent Document 1, because the periphery of the connection part is in contact with the outside, when ink in the second tank heated by the second heater is supplied to the flow path module via the connection part, the temperature of the ink supplied to the flow path module drops due to heat dissipation from the connection part. To compensate for this, the flow path module is heated by the first heater via the frame and nozzle plate, but because the frame and nozzle plate are in contact with the outside air, heat from the first heater is also dissipated therefrom, and there is a risk that the ink in the flow path module will not be heated sufficiently.

[0009] Also, as in Patent Document 2, a configuration in which a heater is provided for each head chip to heat the inside of the head chip is conceivable, but providing the heater near the nozzles creates a problem of complicating the configuration. Specifically, the closer the heater is to the nozzle, the longer the wiring connected to the heater becomes, and the more wiring needs to be routed, complicating the configuration.

[0010] It should be noted that such problems are not limited to ink-jet recording heads that eject ink, but also exist in liquid ejection heads that eject liquids other than ink.

[0011] In view of the above circumstances, the present invention aims to provide a liquid ejection head and a liquid ejection device that can supply liquid that has been sufficiently heated by a heater to a head chip, and that does not require the head chip to be heated by a holder made of a material with high thermal conductivity, thereby simplifying the structure. [Means for solving the problem]

[0012] An aspect of the present invention that solves the above problem is a liquid ejection head comprising: a plurality of head chips having a nozzle plate having a plurality of nozzles that eject liquid in a first direction and a case in which one or more first flow paths are formed that communicate with at least some of the plurality of nozzles; a holder to which the plurality of head chips are fixed and which is composed of a metal or ceramic and has a plurality of second flow paths that communicate with at least one of the plurality of first flow paths; and a heater that heats the holder.

[0013] Another aspect of this embodiment is a liquid ejection device comprising the liquid ejection head of the above aspect and a holding member made of metal that holds the liquid ejection head, wherein a portion of the holding member is positioned so as to sandwich the outer wall of the head between itself and the heater.

[0014] Another aspect of the present invention is a liquid ejection device comprising the liquid ejection head of the above aspect and a holding member made of resin that holds the liquid ejection head, wherein a portion of the holding member is positioned so as to sandwich the outer wall of the head between itself and the heater.

[0015] Another aspect of the present invention is a liquid ejection device comprising the liquid ejection head of the above aspect and a holding member made of resin that holds the liquid ejection head, wherein a portion of the holding member is positioned so as to sandwich the heater between the holder.

[0016] Another aspect of the present invention is a liquid ejecting apparatus comprising the liquid ejecting head according to the above aspect, and a control means for controlling the heater.

[0017] Another aspect of the present invention is a liquid ejecting apparatus comprising: the liquid ejecting head according to the above aspect; and a liquid container that stores liquid to be ejected from the liquid ejecting head. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is an exploded perspective view of the recording head according to the first embodiment. [Diagram 2] FIG. 2 is a top view of the head chip according to the first embodiment. [Diagram 3] 1 is a cross-sectional view of a head chip according to a first embodiment. [Figure 4] FIG. 2 is a top view of the recording head according to the first embodiment. [Diagram 5] 1 is a cross-sectional view of a recording head according to a first embodiment. [Figure 6] 1 is a cross-sectional view of a recording head according to a first embodiment. [Figure 7] FIG. 2 is a perspective view of a holder and a heater according to the first embodiment. [Figure 8] FIG. 2 is a side view of the holder and heater according to the first embodiment. [Figure 9] FIG. 2 is a side view of the holder and heater according to the first embodiment. [Figure 10] FIG. 2 is a side view of the holder and heater according to the first embodiment. [Figure 11] FIG. 11 is a top view showing a modified example of the holder and heater according to the first embodiment. [Figure 12] FIG. 1 is a diagram showing a schematic configuration of a recording apparatus according to a first embodiment. [Figure 13] 2 is a cross-sectional view of a main part of a recording head and a holding member according to the first embodiment. FIG. [Figure 14] 2 is a cross-sectional view of a main part of a recording head and a holding member according to the first embodiment. FIG. [Figure 15] FIG. 11 is a cross-sectional view of a recording head according to a second embodiment. [Figure 16] FIG. 11 is a perspective view of a holder and a heater according to a second embodiment. [Figure 17] FIG. 11 is a cross-sectional view of a recording head according to a second embodiment. [Figure 18] FIG. 11 is a cross-sectional view showing a modified example of the recording head according to the second embodiment. [Figure 19]FIG. 11 is a perspective view showing a modified example of the holder and heater according to the second embodiment. [Figure 20] FIG. 11 is a bottom view of a recording head according to another embodiment. [Figure 21] FIG. 11 is a bottom view of a recording head according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The present invention will be described in detail below based on an embodiment. However, the following description shows one aspect of the present invention and can be arbitrarily modified within the scope of the present invention. In each drawing, the same reference numerals indicate the same members, and the description is omitted as appropriate. In each drawing, X, Y, and Z represent three spatial axes that are mutually orthogonal. In this specification, the directions along these axes are defined as the X direction, the Y direction, and the Z direction. The direction in which the arrow in each drawing points is defined as the positive (+) direction, and the opposite direction to the arrow is defined as the negative (-) direction. The Z direction indicates the vertical direction, the +Z direction indicates the vertical downward direction, and the -Z direction indicates the vertical upward direction. Furthermore, the three spatial axes that are not limited to the positive and negative directions are defined as the ±X direction, the ±Y direction, and the ±Z direction.

[0020] (Embodiment 1) FIG. 1 is an exploded perspective view of an ink jet recording head 1, which is an example of a "liquid jet head" according to a first embodiment of the present invention.

[0021] As shown in the figure, an ink jet recording head 1 (hereinafter, simply referred to as a recording head 1), which is an example of a "liquid jet head" of this embodiment, has a plurality of head chips 10 and a holder 40 that holds the plurality of head chips 10. In this embodiment, four head chips 10 are arranged in one holder 40 in a line in a +Y direction perpendicular to the +Z direction. In this embodiment, the +Z direction is an example of a "first direction", and the +Y direction is an example of a "third direction". Note that the number of head chips 10 held by the holder 40 is not limited to four, and may be two or more. The arrangement of the plurality of head chips 10 is also not limited to this.

[0022] Here, an example of head chip 10 will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a plan view of head chip 10 as viewed in the +Z direction, and Fig. 3 is a cross-sectional view taken along line AA' in Fig. 2. In this embodiment, each direction of head chip 10 will be described based on the direction when it is mounted on recording head 1.

[0023] 2 and 3, head chip 10 includes a nozzle plate 12 provided with a plurality of nozzles 11 that eject ink in the +Z direction, and a case 13 in which an inlet 32 ​​(described below) and an introduced liquid chamber 31 are formed, which are an example of a "first flow path" that communicates with the plurality of nozzles 11. Head chip 10 of this embodiment further includes a communication plate 14, a pressure chamber forming substrate 15, a vibration plate 16, a compliance substrate 17, a piezoelectric actuator 18, and the like. The plurality of components that make up head chip 10 are stacked and bonded with an adhesive or the like to form a unit.

[0024] The pressure chamber forming substrate 15 of this embodiment has a plurality of pressure chambers 19 communicating with each of the nozzles 11 formed in the nozzle plate 12. A plurality of piezoelectric actuators 18 are provided corresponding to each pressure chamber 19. The piezoelectric actuator 18 is an energy generating element that generates a pressure fluctuation in the ink in the corresponding pressure chamber 19, that is, energy required for ejecting the ink from the nozzle 11 communicating with the pressure chamber 19, and is also a pressure generating element. A vibration plate 16 is provided between the pressure chamber 19 and the piezoelectric actuator 18, and the opening on the -Z direction side of the pressure chamber 19 is sealed by this vibration plate 16 to partition a part of the pressure chamber 19. The pressure chamber forming substrate 15 and the vibration plate 16 may be integrally formed. Then, the piezoelectric actuators 18 are laminated in the areas on the vibration plate 16 corresponding to each pressure chamber 19. The piezoelectric actuator 18 of this embodiment is formed by sequentially laminating a first electrode 20, a piezoelectric layer 21, and a second electrode 22 on the vibration plate 16. The piezoelectric actuator 18 thus configured is deflected and deformed when an electric field corresponding to the potential difference between the first electrode 20 and the second electrode 22 is applied between the two electrodes.

[0025] A flexible wiring board 23 is connected to the piezoelectric actuator 18. In this embodiment, the electrodes of the piezoelectric actuator 18 are connected to the wiring board 23 via lead-out wiring 24 that is led out from the piezoelectric actuator 18 to above the diaphragm 16. A driving circuit 25, such as a circuit board having switching elements such as a transmission gate for driving the piezoelectric actuator 18 and a semiconductor integrated circuit (IC), is mounted on the wiring board 23. Such a wiring board 23 is led out in the -Z direction of the pressure chamber forming substrate 15.

[0026] A communication plate 14 having a larger area than the pressure chamber forming substrate 15 in a plan view in the +Z direction is bonded to the surface of the pressure chamber forming substrate 15 on the +Z direction side. In the communication plate 14 of this embodiment, a nozzle communication port 26 that communicates the pressure chamber 19 with the nozzle 11, a common liquid chamber 27 provided in common to each pressure chamber 19, and an individual communication port 28 that communicates the common liquid chamber 27 with the pressure chamber 19 are formed. The common liquid chamber 27 is a space extending along the ±X direction in which the nozzles 11 are arranged side by side. In this embodiment, two common liquid chambers 27 are formed corresponding to the two rows of nozzles 11 provided in the nozzle plate 12, respectively. A plurality of individual communication ports 28 are formed along the ±X direction, which is the nozzle row direction, corresponding to each pressure chamber 19. The individual communication port 28 communicates with an end of the pressure chamber 19 on the opposite side to the part that communicates with the nozzle communication port 26.

[0027] A nozzle plate 12 having a plurality of nozzles 11 formed therein is bonded to the approximate center of the surface of the communicating plate 14 on the +Z direction side. The nozzle plate 12 in this embodiment is a plate material having an outer shape smaller than that of the communicating plate 14 in a plan view in the -Z direction. The nozzle plate 12 is bonded to the surface of the communicating plate 14 on the +Z direction side at a position away from the opening of the common liquid chamber 27, in an area where the nozzle communication openings 26 are open, with an adhesive or the like in a state in which the nozzle communication openings 26 communicate with the plurality of nozzles 11. The nozzle plate 12 in this embodiment has a total of two nozzle rows (not shown) formed therein, each of which has a plurality of nozzles 11 arranged in the +X direction, which is the nozzle row direction described above. The two nozzle rows are arranged in the +Y direction.

[0028] Further, a compliance substrate 17 is bonded to the surface of the communicating plate 14 on the +Z direction side at a position away from the nozzle plate 12. This compliance substrate 17, in a state where it is positioned and bonded to the surface of the communicating plate 14 on the +Z direction side, seals the opening of the common liquid chamber 27 on the surface of the communicating plate 14 on the +Z direction side.

[0029] In this embodiment, the compliance substrate 17 includes a sealing film 17a made of a flexible thin film such as resin, and a fixed substrate 17b made of a hard material such as a metal such as stainless steel. The area of ​​the fixed substrate 17b facing the common liquid chamber 27 is a fixed substrate opening 17c that is completely removed in the thickness direction, so that one side of the common liquid chamber 27 is a compliance portion 17d that is a flexible portion sealed only by the flexible sealing film 17a. The compliance portion 17d flexibly deforms to reduce pressure fluctuations in the ink flow paths, particularly in the common liquid chamber 27.

[0030] In addition, a protection substrate 29 having approximately the same size as the pressure chamber forming substrate 15 is bonded to the pressure chamber forming substrate 15 in the -Z direction. The protection substrate 29 has a holding portion 30 which is a space for protecting the piezoelectric actuator 18.

[0031] The pressure chamber forming substrate 15, the protective substrate 29, and the communication plate 14 are fixed to the case 13. Inside the case 13, on both sides of the pressure chamber forming substrate 15, there are formed introduction liquid chambers 31 communicating with the common liquid chamber 27 of the communication plate 14. In addition, on the surface on the -Z direction side of the case 13, introduction ports 32 communicating with each introduction liquid chamber 31 are opened. The introduction ports 32 communicate with a second flow path 50 provided in the holder 40, which will be described in detail later. Therefore, ink sent from the holder 40 is introduced into the introduction port 32, the introduction liquid chamber 31, and the common liquid chamber 27, and is supplied to each pressure chamber 19 from the common liquid chamber 27 through the individual communication port 28. In this embodiment, the introduction port 32 and the introduction liquid chamber 31 provided in the case 13 correspond to the "first flow path" described in the claims. In addition, the protective substrate 29 and the case 13 are provided with a wiring insertion hole 33 through which the wiring board 23 is inserted. The wiring board 23 drawn out in the −Z direction from the pressure chamber forming substrate 15 passes through the protective board 29 and the wiring insertion hole 33 of the case 13, and is drawn out to the −Z direction side of the case 13.

[0032] In this embodiment, the case 13 is made of resin. The resin constituting the case 13 may be, for example, a thermoplastic resin or a thermosetting resin. Examples of the thermoplastic resin include polyphenylene ether resin (PPE), modified polyphenylene ether resin (m-PPE), polyethylene resin (PE), polystyrene resin (PS), polyamide resin (PA), PPS, PP, LCP, ABS resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl chloride resin, and mixtures thereof. Examples of the thermosetting resin include phenolic resin such as Bakelite, epoxy resin such as epoxy glass, urethane resin, melamine resin, and ester resin. It is preferable to use a thermosetting resin with excellent temperature stability, liquid resistance, and high rigidity for the case 13. By forming the case 13 from resin in this way, the thermal conductivity can be reduced compared to metal and the like. Therefore, it is possible to suppress a drop in the temperature of the ink flowing through the inlet 32 ​​and the introduction liquid chamber 31, which are the first flow path provided in the case 13, and to guide the ink with the temperature drop suppressed to the nozzle 11. Furthermore, by forming the case 13 from resin, it is possible to reduce costs compared to when the case 13 is formed from metal or ceramics. In particular, since one recording head 1 is provided with a plurality of head chips 10, by forming the case 13 from resin, it is possible to reduce the number of metal parts or ceramic parts used in the head chips 10, and to reduce costs relatively significantly. Of course, the case 13 may be formed from a material other than resin, for example, metal or ceramics.

[0033] In the head chip 10 having the above configuration, when the flow path from the introduction liquid chamber 31 through the common liquid chamber 27 and the pressure chamber 19 to the nozzle 11 is filled with ink, a pressure fluctuation occurs in the ink in the pressure chamber 19 when the piezoelectric actuator 18 is driven, and this pressure fluctuation causes ink to be ejected from a specified nozzle 11.

[0034] In addition, the case 13 of the head chip 10 of this embodiment has two "first flow paths", and the nozzle plate 12 of this embodiment has a plurality of nozzles 11 constituting two nozzle rows, and the plurality of nozzles 11 constituting one nozzle row communicates with one "first flow path", and the plurality of nozzles 11 constituting the other nozzle row communicates with the other "first flow path", but is not limited to this aspect. The case 13 of the head chip 10 only needs to have one or more "first flow paths", and the "first flow path" only needs to communicate with at least a portion of the plurality of nozzles 11 provided in the nozzle plate 12. The "first flow path" communicating with at least a portion of the plurality of nozzles 11 provided in the nozzle plate 12 may include a configuration in which the "first flow path" communicates with all of the plurality of nozzles 11 provided in the nozzle plate 12, and also includes a configuration in which the "first flow path" communicates with two or more of the plurality of nozzles 11 provided in the nozzle plate 12.

[0035] 1, in this embodiment, the four head chips 10 are held by holder 40 at a predetermined interval along the +Y direction with the nozzle row direction aligned along the +X direction and with the head chips 10 at the same position in the +X direction. The +Y direction is an example of the "third direction".

[0036] Holder 40 has multiple head chips 10, four in this embodiment, fixed to a surface in the +Z direction, and is provided with an inlet 32, which is a "first flow path" provided in case 13 of head chip 10, and a second flow path 50 which communicates with introduction liquid chamber 31.

[0037] Here, the holder 40 will be further described with reference to Figs. 4 to 10. Fig. 4 is a top view of the recording head 1. Fig. 5 is a cross-sectional view taken along line BB' in Fig. 4. Fig. 6 is a cross-sectional view taken along line CC' in Fig. 4. Fig. 7 is a perspective view of the holder 40 and the heater 70, in which only two second flow paths 50 for one head chip 10 are indicated by dotted lines. Figs. 8 to 10 are side views of the holder 40 and the heater 70.

[0038] As shown in the figure, the holder 40 of this embodiment is made up of a first member 41, a second member 42, and a third member 43 stacked in this order in the +Z direction and bonded together with an adhesive or the like. The method of fixing the members constituting the holder 40 is not limited to bonding with an adhesive, and they may be fastened with screws, bolts, or the like. A sealant or the like may be provided between the members constituting the holder 40 to suppress leakage of ink from the second flow path 50.

[0039] The holder 40 is configured to include a metal or ceramics. Here, the statement that the holder 40 is configured to include a metal or ceramics includes that at least one member among the multiple members that configure the holder 40 is configured to include a metal or ceramics. In other words, as long as at least one member among the multiple members that configure the holder 40 is configured to include a metal or ceramics, the other members may be configured to include a material other than metal and ceramics, such as a resin.

[0040] In addition, the holder 40 being configured to include metal or ceramics includes at least a part of the members that configure the holder being configured to include metal or ceramics. In other words, it includes that all or a part of one of the multiple members that configure the holder 40 is configured to include metal or ceramics. In other words, as long as at least a part of one of the multiple members that configure the holder 40 is configured to include metal or ceramics, the other parts may be configured to include materials other than metal and ceramics, such as resin. Note that members configured to include metal or ceramics and other materials such as resin can be integrally manufactured by, for example, insert molding or the like.

[0041] Moreover, the holder 40 being configured to contain metal or ceramics includes the holder 40 having 80% or more of its volume configured to be made of metal or ceramics.

[0042] Furthermore, the holder 40 being configured to contain metal or ceramic includes that at least a portion of the outer peripheral wall 46 on which the heater 70 described in detail below is provided, to a portion forming at least a portion of the inner wall surface of the second flow passage 50, is made of metal or ceramic. In this manner, by forming at least a portion of the outer peripheral wall 46 on which the heater 70 of the holder 40 is provided, to at least a portion of the inner wall surface of the second flow passage 50, from metal or ceramic, the heat of the heater 70 can be efficiently transferred to the ink flowing through the second flow passage 50.

[0043] In this embodiment, the first member 41, the second member 42, and the third member 43 constituting the holder 40 are all formed of the same metal or ceramic. Here, examples of the metal constituting the holder 40 include materials with high liquid resistance, such as stainless steel and titanium. Examples of the ceramics constituting the holder 40 include ceramics with good thermal conductivity, such as aluminum nitride, silicon carbide, alumina, and silicon nitride. The thermal conductivity of ceramics is 150 W / m·k for aluminum nitride, 60 W / m·k for silicon carbide, 32 W / m·k for alumina, and 20 W / m·k for silicon nitride. Therefore, by forming the holder 40 from the above-mentioned ceramics, the thermal conductivity can be made higher than that of metals, and the heat of the heater 70, which will be described in detail later, can be easily conducted to the ink in the second flow path 50. Furthermore, by forming the holder 40 from a metal, although the thermal conductivity is lower than that of ceramics, the thermal conductivity can be made higher than that of resin, and the metal can be relatively easily processed and has high rigidity. It is preferable that the first member 41, the second member 42, and the third member 43 are made of materials having the same linear expansion coefficient. By using the same material for the first member 41, the second member 42, and the third member 43 in this way, it is possible to suppress damage such as peeling and cracking due to warping caused by differences in linear expansion coefficients. In particular, since the holder 40 is heated by the heater 70, which will be described in detail later, damage such as peeling and cracking due to warping is likely to occur due to differences in linear expansion coefficients of the members constituting the holder 40. By using the same material for the members constituting the holder 40, it is possible to suppress damage such as peeling and cracking due to warping caused by differences in linear expansion coefficients even when the holder 40 is heated by the heater 70.

[0044] The first member 41 and the second member 42 have substantially the same outer shape in a plan view in the +Z direction. In this embodiment, the first member 41 and the second member 42 have a substantially rectangular shape in a plan view in the +Z direction. The shapes of the first member 41 and the second member 42 in a plan view in the +Z direction are not limited to a rectangular shape, and may be a polygonal shape, a circular shape, an elliptical shape, or the like.

[0045] Moreover, the third member 43 is formed with an outer shape in the +Z direction side that is approximately the same size as the first member 41 and the second member 42 in a plan view seen in the +Z direction. Moreover, a protrusion 43a is provided on the +Z direction side of the third member 43, protruding outward from the first member 41 and the second member 42 in a plan view seen in the +Z direction, i.e., protruding in the ±X and ±Y directions. By providing the protrusion 43a in this manner, the heater 70, which will be described in detail later, can be positioned by abutting against the surface on the -Z direction side of the protrusion 43a, so that the heater 70 can be easily positioned relative to the holder 40 in the ±Z directions.

[0046] In this embodiment, an outer wall having a surface in the -Z direction, which is the opposite direction to the +Z direction of holder 40, is referred to as upper wall 44, an outer wall having a surface in the +Z direction, which is the "first direction", is referred to as lower wall 45, and an outer wall having a side surface connecting upper wall 44 and lower wall 45, i.e., a side surface along the ±Z directions and including either the ±X direction or the ±Y direction and the ±Z direction, is referred to as outer peripheral wall 46. The -Z direction is an example of the "second direction".

[0047] The bottom wall 45 of the third member 43 has a plurality of recesses 47 that accommodate the head chips 10. The recesses 47 are formed to open on the bottom wall 45, that is, on the surface of the holder 40 in the +Z direction, and have approximately the same opening area toward the -Z direction. In this embodiment, the recesses 47 that accommodate the head chips 10 are provided, and therefore a partition wall 48 made of a part of the third member 43 is provided between the head chips 10 adjacent to each other in the +Y direction. In this way, by providing the holder 40 with the recesses 47 that accommodate the head chips 10, the rigidity of the holder 40 can be improved, and the landing position deviation of the ink droplets ejected from each head chip 10 can be suppressed. Each head chip 10 is fixed to the bottom surface of each recess 47 of the holder 40 with an adhesive or the like so as to leave a gap on the inner peripheral surface of each recess 47. The bottom surface of the recess 47 refers to the surface of the recess 47 on the -Z direction side. In addition, although details will be described later, a common fixing plate 60 is fixed to the nozzle plate 12 side of the multiple head chips 10. A part of this fixing plate 60 is fixed to the partition wall 48 between the adjacent recesses 47. By fixing the fixing plate 60 by the partition wall 48 in this manner, the rigidity of the fixing plate 60 can be further improved, and the occurrence of relative positional deviation of the multiple head chips 10 due to deformation of the fixing plate 60 can be suppressed. Of course, the recesses 47 that accommodate the head chips 10 of the holder 40 are not limited to this, and two or more multiple head chips 10 may be accommodated in one recess 47.

[0048] In addition, a fixing plate 60 is fixed to the lower wall 45 including the partition wall 48 of the holder 40. The fixing plate 60 is made of a metal such as stainless steel or titanium. This fixing plate 60 is provided with a plurality of exposure openings 61 for exposing the nozzle plate 12 of the head chip 10. The exposure openings 61 of this embodiment are slightly larger than the nozzle plate 12 and smaller than the outer shape of the compliance substrate 17. For this reason, the exposure openings 61 are provided independently for each nozzle plate 12. The fixing plate 60 is also bonded to the compliance substrate 17 of the head chip 10. Of course, the exposure openings 61 may be provided with a size that exposes two or more nozzle plates 12.

[0049] Since the fixing plate 60 made of such a metal is fixed to the lower wall 45, the heat of the heater 70 fixed to the holder 40 can be transferred to the "first flow path" in the head chip 10 via the lower wall 45, the fixing plate 60, and the compliance substrate 17. Furthermore, in this embodiment, since the partition wall 48 is provided between the head chips 10 adjacent to each other in the +Y direction as described above, the heat of the heater 70 can be transferred to the "first flow path" in the head chip 10 via the partition wall 48, the fixing plate 60, and the compliance substrate 17 even for the head chip 10 arranged away from the heater 70. Therefore, the heater 70 can efficiently heat the multiple head chips 10 via the fixing plate 60. Furthermore, by fixing the fixing plate 60 to the partition wall 48, the heat of the heater 70 can be transferred to the central side in the plane including the ±X direction and the ±Y direction of the holder 40 via the lower wall 45, the fixing plate 60, and the partition wall 48, and the entire holder 40 can be heated by the heater 70 with reduced bias, and the occurrence of variation in the heating temperature of the ink passing through the multiple second flow paths 50 can be suppressed.

[0050] The holder 40 is provided with a second flow path 50 that communicates with the inlet 32 ​​and the introduction liquid chamber 31, which are the "first flow path" provided in the case 13 of the head chip 10. In this embodiment, four head chips 10 each having two independent "first flow paths" are fixed to the holder 40, so that the holder 40 is provided with a total of eight second flow paths 50. The second flow paths 50 are provided with one end opening to the +Z direction surface of the holder 40, which in this embodiment is the bottom surface of the recess 47, and the other end opening to the -Z direction surface of the holder 40. One end of the second flow path 50 that opens to the bottom surface of the recess 47 is connected to the inlet 32, which is a part of the "first flow path" provided in the case 13 of the head chip 10.

[0051] Here, each second flow path 50 in this embodiment includes a first portion 51, a second portion 52, and a third portion 53. The first portion 51 is provided penetrating the first member 41 in the Z direction. The -Z direction end of the first portion 51 is provided in a protruding portion 41a that protrudes in the -Z direction further than the upper wall 44 of the holder 40. In other words, the -Z direction end of the second flow path 50 is provided protruding in the -Z direction from the upper wall 44. In this embodiment, the portion provided in the protruding portion 41a that protrudes in the -Z direction from the upper wall 44 of the first portion 51 is referred to as a connection portion 51a. Note that, in this embodiment, the protruding portion 41a is provided integrally and continuously with the first member 41. Of course, the protruding portion 41a may be fixed to the first member 41 as a separate body from the first member 41.

[0052] The second portion 52 is provided between the first member 41 and the second member 42 along a plane including a direction intersecting the +Z direction, which in this embodiment is a plane including the ±X direction and the ±Y direction perpendicular to the +Z direction. That is, in this embodiment, the second portion 52 is an "intersection portion" extending in a direction intersecting the +Z direction, which is the "first direction". The second portion 52 is arranged by being routed along a plane including the ±X direction and the ±Y direction so that one end of the second portion 52 is connected to the end of the first portion 51 in the +Z direction and the other end of the second portion 52 is connected to the end of the third portion 53 in the -Z direction. In addition, the second portion 52 in this embodiment is formed by providing a recess on the surface of the first member 41 in the +Z direction and covering the opening of the recess with the second member 42. Of course, the second portion 52 may be formed by providing a recess on the surface of the second member 42 in the -Z direction and covering the opening of the recess of the second member 42 with the first member 41, or by providing recesses in both the first member 41 and the second member 42 and matching the openings of the two recesses. In the present embodiment, the second portion 52, which is the "intersection portion", is provided between the first member 41 and the second member 42, but is not particularly limited thereto, and the "intersection portion" may be provided between the second member 42 and the third member 43.

[0053] The third portion 53 is provided penetrating the second member 42 and the third member 43 in the +Z direction. The third portion 53 is provided such that its -Z end is connected to the end of the second portion 52. The +Z end of the third portion 53 is provided to open to the +Z face of the holder 40, i.e., the bottom face of the recess 47. In this embodiment, the third portion 53 is a "communicating portion" that communicates with the inlet 32, which is the "first flow path" provided in the case 13 of the head chip 10.

[0054] That is, the first portion 51 and the third portion 53 constituting the second flow path 50 in this embodiment extend along the +Z direction, which is the "first direction", and the second portion 52 constituting the second flow path 50 extends along a direction intersecting the +Z direction, which in this embodiment is a plane including the ±X direction and the ±Y direction perpendicular to the +Z direction. By providing the second portion 52, which is an "intersection portion", in the second flow path 50 in this manner, the second flow path 50 can be routed in a direction intersecting the +Z direction, and the second flow paths 50 can be prevented from interfering with each other in the holder 40, and can also be prevented from interfering with other openings, other members, and the like. By preventing interference of the second flow paths 50, the size of the holder 40 can be prevented from increasing.

[0055] The holder 40 is provided with a plurality of such second flow paths 50, eight in this embodiment, and is provided with a heater 70 for heating the ink flowing through the plurality of second flow paths 50. Here, the heater 70 is not particularly limited, but in this embodiment, it is made of a flexible film heater. The heater 70 made of a film heater has a heat generating portion 71 and a film member 72 covering the heat generating portion 71, as shown in FIG. 8. Specifically, the film member 72 has a base film as a substrate and a protective film as an insulator, and the film heater is configured by laminating the base film, the heat generating portion 71, and the protective film in this order. The heat generating portion 71 of the heater 70 is a heat generating resistor, for example, stainless steel, copper, tungsten, nickel alloy, aluminum foil, or the like. In this embodiment, stainless steel, which has high ink resistance, is used as the heat generating resistor of the heat generating portion 71. The base film and the protective film are preferably insulating, and for example, polyimide, polyethylene terephthalate, polyethylene naphthalate, or the like can be used. Note that a film-like solder resist having insulating properties may be used instead of the protective film of the film member 72. As shown in FIG. 8, the heater 70, which is a film heater, does not have a heat generating portion 71 at its end portion, and only the film member 72 exists.

[0056] Moreover, the heater 70 being provided on the holder 40 means that the heater 70 is in direct contact with the holder 40. For example, another member made of a material with high thermal conductivity may be provided between the holder 40 and the heater 70, but this would reduce the heating efficiency of the heater 70 and increase the size of the holder 40 in which the heater 70 is provided, resulting in an increase in the size of the recording head 1. For this reason, it is preferable that the holder 40 and the heater 70 are in direct contact with each other.

[0057] The heater 70 of the present embodiment is provided so as to surround the plurality of second flow paths 50 in a plan view seen in the +Z direction, and to overlap at least a portion of the second flow paths 50 when viewed in a direction perpendicular to the +Z direction, i.e., in an in-plane direction including the ±X direction and the ±Y direction. That is, the heater 70 may be provided at a position where at least a portion of the heater 70 overlaps at least one of the first portion 51, the second portion 52, and the third portion 53 constituting the second flow path 50 when viewed in an in-plane direction including the ±X direction and the ±Y direction. In this way, the heater 70 is provided so as to surround the plurality of second flow paths 50, so that the second flow paths 50 disposed away from the outer peripheral wall 46 of the holder 40 can be effectively heated by the heater 70. That is, the second flow paths 50 on the center side in the ±Y direction among the plurality of second flow paths 50 are separated from the heater 70 provided on the outer peripheral wall 46 on both sides in the ±Y direction of the holder 40. However, by providing the heater 70 so as to surround the multiple second flow paths 50, that is, by providing the heater 70 on the outer peripheral walls 46 on both sides in the ±X directions of the holder 40, the second flow paths 50 disposed away from the outer peripheral walls 46 on both sides in the ±Y directions can be heated by the heater 70 provided on the outer peripheral walls 46 on both sides in the ±X directions. Furthermore, by providing the heater 70 so as to surround the multiple second flow paths 50, heat radiation from the holder 40 can be suppressed.

[0058] Moreover, the heater 70 is preferably disposed so as to overlap across the second portion 52, which is the "intersection portion," and the third portion 53, which is the "communication portion," when viewed in a direction perpendicular to the +Z direction, i.e., an in-plane direction including the ±X and ±Y directions. In other words, it is sufficient that the heater 70 is disposed so as to overlap across at least a part of the second portion 52 on a side that communicates with the third portion 53, and at least a part of the third portion 53 on a side that communicates with the second portion 52.

[0059] The second flow path 50 has a longer flow path length due to the provision of the second portion 52, and the heater 70 heats the second portion 52 which increases the flow path length, thereby effectively heating the ink passing through the second portion 52. In addition, since the heater 70 extends in the +Z direction across the second portion 52 and the third portion 53, the length in the +Z direction over which the heater 70 heats the ink can be increased, and the ink can be effectively heated.

[0060] In other words, the heater 70 is preferably positioned at a position overlapping the second portion 52 when viewed in a direction perpendicular to the +Z direction, and is preferably positioned so that the length of overlap with the second flow path 50 in the +Z direction is as long as possible.

[0061] The position of the heater 70 in the +Z direction relative to the holder 40 in this embodiment is such that the heater 70 overlaps the first portion 51, the second portion 52, and the third portion 53 of the second flow path 50 of the holder 40. In other words, the heater in this embodiment is arranged so as to completely overlap the second portion 52 when viewed in an in-plane direction including the ±X and ±Y directions, and to overlap the first portion 51 and a portion of the third portion 53 on the side communicating with the second portion 52. As a result, the heater 70 can heat the ink flowing in the first portion 51 in addition to the second portion 52 and the third portion 53, and therefore can effectively heat the ink flowing in the second flow path 50.

[0062] Moreover, the heater 70, which is a film heater, is wrapped around the outer peripheral wall 46 of the holder 40 in a plan view seen in the +Z direction, and is fixed to the outer peripheral wall 46. That is, the heater 70 includes a first portion 73 extending in the "third direction" in which the head chips 10 are arranged side by side, that is, the +Y direction, and a second portion 74 extending in a direction intersecting the +Z direction and the +Y direction, in this embodiment, in the +X direction perpendicular to the +Z direction and the +Y direction. The first portion 73 is provided on the outer peripheral wall 46 on both sides in the ±X direction. The second portion 74 is provided on the outer peripheral wall 46 on both sides in the ±Y direction. In this way, the heater 70 can be easily attached to the holder 40 by simply wrapping the flexible, long heater 70 around the outer peripheral wall 46 of the holder 40. Furthermore, by wrapping the heater 70 around the entire outer peripheral wall 46 of the holder 40 , heat radiation from the holder 40 is suppressed, and the holder 40 can be efficiently heated by the heater 70 .

[0063] Furthermore, the method of fixing the heater 70 to the outer peripheral wall 46 is not particularly limited, and the heater 70 may simply be wound around the outer peripheral wall 46, or ends of the heater 70 may be bonded together in a state where the heater 70 is wound around the outer peripheral wall 46. The heater 70 may also be bonded to the outer peripheral wall 46 with an adhesive, or a part of the heater 70 may be welded to the outer peripheral wall 46. Furthermore, the heater 70 may be fixed to the outer peripheral wall 46 with screws, bolts, or the like.

[0064] Here, as shown in FIG. 8, both ends of the heater 70 wrapped around the outer peripheral wall 46 of the holder 40 are arranged with a gap between them so that they do not overlap each other. That is, one end 72a and the other end 72b of the film member 72 of the heater 70 are arranged with a gap between them so that they do not overlap each other. In this way, by arranging both ends of the heater 70 with a gap between them so that they do not overlap each other on the outer peripheral wall 46 of the holder 40, it is possible to suppress an increase in thickness due to the overlap of both ends of the heater 70, and to suppress an increase in size of the holder 40 around which the heater 70 is wrapped. In other words, the heater 70 being wrapped around the outer peripheral wall 46 of the holder 40 in a plan view seen in the +Z direction is not limited to the heater 70 being provided continuously around the entire circumference of the outer peripheral wall 46 in a plan view seen in the +Z direction, but also includes the heater 70 being wrapped around the holder 40 so that a part of the outer peripheral wall 46 of the holder 40 is exposed. For example, the phrase "the heater 70 is wrapped around so as to cover the outer peripheral wall 46 of the holder 40" means that the heater 70 covers 75% or more of the entire circumference of the outer peripheral wall 46. Furthermore, the phrase "the heater 70 surrounds the second flow paths 50" means that the heater 70 surrounds the second flow paths 50 in three or more of the four directions, that is, the +X direction, the -X direction, the +Y direction, and the -Y direction, which surround the second flow paths 50 in a plan view seen in the +Z direction.

[0065] 9, one end 71a and the other end 71b of the heat generating portion 71 may overlap each other at both ends of the heater 70 wrapped around the outer peripheral wall 46 of the holder 40. This allows the heat generating portion 71 to cover the entire outer peripheral wall 46 of the holder 40 when viewed in a plan view in the +Z direction, and the holder 40 can be effectively heated.

[0066] 10, one end 71a and the other end 71b of the heat generating portion 71 may not overlap each other at both ends of the heater 70 wrapped around the outer peripheral wall 46 of the holder 40, and one end 72a and the other end 72b of the film member 72 may be arranged to overlap each other. This makes it possible to increase the area that the heat generating portion 71 covers over the outer peripheral wall 46 of the holder 40 when viewed in a plan view from the +Z direction, thereby improving the heating efficiency of the holder 40 and preventing the outer periphery of the holder 40 around which the heater 70 is wrapped from becoming larger.

[0067] By providing the heater 70 in the holder 40 in which the second flow paths 50 are provided in this manner, the ink passing through the second flow paths 50 can be heated by the heater 70. In particular, in this embodiment, the heater 70 surrounds the multiple second flow paths 50 and is disposed so as to overlap at least a portion of the second flow paths 50 when viewed in an in-plane direction including the ±X directions and the ±Y directions, so that the ink passing through the multiple second flow paths 50 can be effectively heated by the heater 70.

[0068] Moreover, the holder 40 is provided with first wiring insertion holes 49 for drawing out the wiring board 23 of the head chip 10 fixed on the +Z direction side to the -Z direction side of the holder 40. The first wiring insertion holes 49 are provided independently for each of the wiring boards 23. That is, the first wiring insertion holes 49 are provided with one end opening to the bottom surface of the recess 47 and the other end opening to the surface of the holder 40 in the +Z direction. Therefore, the holder 40 is provided with a total of four first wiring insertion holes 49.

[0069] The holder 40 with the heater 70 wound around the outer peripheral wall 46 is covered with a holder cover 80 .

[0070] The holder cover 80 has a concave-shaped accommodation section 81 that opens on the surface on the +Z direction side, and the holder 40 around which the heater 70 is wound is accommodated in this accommodation section. The opening on the surface on the +Z direction side of the accommodation section 81 is provided to be slightly larger than the outer shape of the holder 40 around which the heater 70 is wound, and is smaller than the convex portion 43a of the third member 43 of the holder 40. Therefore, when the -Z direction side of the holder 40 is accommodated in the accommodation section 81 of the holder cover 80, the +Z direction surface where the accommodation section 81 of the holder cover 80 opens and the -Z direction surface of the convex portion 43a of the holder 40 are fixed to each other in a state of abutting against each other when the holder cover 80 and the holder 40 are fixed to each other in a fixing manner. The fixing method of the holder cover 80 and the holder 40 is not particularly limited, and may be adhesion by an adhesive, or may be fixing by screws, bolts, or the like. In addition, although not particularly shown, the holder cover 80 has an opening for drawing out the wiring connected to the heater 70 to the outside. This opening may be provided on the surface of the holder cover 80 on the -Z direction side, or on a side surface intersecting the +Z direction. Of course, the wiring of the heater 70 may be drawn out to the outside from the opening of the housing part 81 on the +Z direction side.

[0071] Further, the holder cover 80 is provided with a first through hole 82 penetrating in the +Z direction, into which the protrusion 41a of the holder 40 is inserted. That is, the first through hole 82 is provided penetrating through the bottom surface of the accommodation portion 81 and the surface of the holder cover 80 on the +Z direction side. When the holder 40 is accommodated in the accommodation portion 81 of the holder cover 80, the protrusion 41a of the holder 40 passes through the first through hole 82 and protrudes toward the -Z direction side.

[0072] Further, a second wiring insertion hole 83 communicating with the first wiring insertion hole 49 of the holder 40 is provided penetrating the holder cover 80 in the +Z direction. Therefore, the wiring board 23 of the head chip 10 fixed to the surface of the holder 40 in the +Z direction is drawn out to the -Z direction side of the holder cover 80 via the first wiring insertion hole 49 of the holder 40 and the second wiring insertion hole 83 of the holder cover 80.

[0073] Further, a relay board 90 common to the multiple wiring boards 23 is held on the surface of the holder cover 80 in the -Z direction. The relay board 90 is provided with a third wiring insertion hole 91 communicating with the second wiring insertion hole 83 of the holder cover 80. Therefore, the wiring board 23 of the head chip 10 is drawn out to the -Z direction side of the relay board 90 via the first wiring insertion hole 49 of the holder 40, the second wiring insertion hole 83 of the holder cover 80, and the third wiring insertion hole 91 of the relay board 90, and is connected to the relay board 90 on the surface of the relay board 90 in the -Z direction.

[0074] Further, the relay substrate 90 is provided with a second through hole 92 that is in communication with the first through hole 82 of the holder cover 80 and penetrates in the +Z direction. Therefore, the protrusion 41a of the holder 40 is provided to protrude in the -Z direction from the relay substrate 90 via the first through hole 82 of the holder cover 80 and the second through hole 92 of the relay substrate 90. Ink is supplied from the outside to the opening of the second flow path 50 of the protrusion 41a provided to protrude in the -Z direction from the relay substrate 90, that is, to the opening of the connection portion 51a. The protrusion 41a in this embodiment is a flow path pipe in which a part of the second flow path 50 (connection portion 51a) is formed inside, but may be a flow path needle with a pointed tip on the -Z direction side.

[0075] Such a holder cover 80 includes a head outer wall 84 arranged so as to sandwich the heater 70 between the holder 40 and the head outer wall 84. That is, the head outer wall 84 is a portion outside the housing portion 81 that defines the inner side surface of the housing portion 81 in a direction perpendicular to the +Z direction. The head outer wall 84 is made of a material having a lower thermal conductivity than the holder 40, for example, a resin. In this embodiment, the entire holder cover 80 is made of a material having a lower thermal conductivity than the holder 40, for example, a resin. Of course, this is not limited to this, and at least the head outer wall 84 of the holder cover 80 may be formed of a material having a lower thermal conductivity than the holder 40, and other portions may be formed of different materials. Note that, for example, the same resin as the case 13 may be used as the resin used for the head outer wall 84 of the holder cover 80. In this way, by forming the head outer wall 84 from a material having a lower thermal conductivity than the holder 40, it is possible to suppress the heat of the heater 70 and the heat of the holder 40 heated by the heater 70 from being dissipated through the head outer wall 84. Furthermore, in this embodiment, by forming the entire holder cover 80 from a material having a lower thermal conductivity than the holder 40, it is possible to further suppress the dissipation of heat from the heater 70 and the holder 40. Therefore, there is no need to heat the heater 70 excessively, and the temperature of the ink flowing through the second flow path 50 can be easily managed by controlling the temperature of the heater 70.

[0076] On the other hand, if the thermal conductivity of the head outer wall 84 is the same as or higher than that of the holder 40, the heat of the heater 70 and the heat of the holder 40 heated by the heater 70 will be dissipated from the head outer wall 84. In other words, the temperature of the outside opposite the housing section 81 of the head outer wall 84, for example, the temperature of a holding member such as a carriage that holds the holder cover 80 and the outside air temperature, is likely to affect the heater 70 and the holder 40, which can easily cause problems such as excessive heating of the heater 70 or frequent temperature control of the heater 70.

[0077] As described above, the recording head 1, which is a liquid ejection head of this embodiment, includes a nozzle plate 12 having a plurality of nozzles 11 that eject ink, which is a liquid, in the +Z direction, which is the "first direction", a case 13 in which an inlet 32 ​​and an introduction liquid chamber 31, which are one or more "first flow paths" that communicate with at least a part of the plurality of nozzles 11, are formed, a holder 40 to which the plurality of head chips 10 are fixed and which is configured to include metal or ceramics, and which has a plurality of second flow paths 50 that communicate with at least one of the plurality of inlets 32 and the introduction liquid chamber 31, and a heater 70 that heats the holder 40. In this embodiment, the case 13 is formed with two inlets 32 and introduction liquid chambers 31, which are "first flow paths" that communicate with the plurality of nozzles 11. In addition, the holder 40 is provided with second flow paths 50 that communicate with each of the plurality of inlets 32 and the introduction liquid chamber 31.

[0078] In this way, the second flow paths 50 arranged near the head chip 10 can be heated by the heater 70, so that the head chip 10 can be supplied with sufficiently heated ink. In addition, since the holder 40 heated by the heater 70 is made of metal or ceramics with high thermal conductivity, the heater 70 can sufficiently heat the ink flowing through the second flow paths 50, and sufficiently heated ink can be supplied to the head chip 10 arranged at a position away from the heater 70. Therefore, the viscosity of the ink ejected from the head chip 10 can be reduced, and the ink ejection characteristics can be prevented from deteriorating. Furthermore, since the heater 70 is not configured to heat the head chip 10 itself, the wiring connected to the heater 70 and the configuration of the recording head 1 can be simplified.

[0079] Moreover, in the recording head 1 of this embodiment, it is preferable that the case 13 is made of resin. In this way, by making the case 13 of a resin with low thermal conductivity, it is possible to suppress a decrease in temperature of the ink in the inlet 32 ​​and the liquid introduction chamber 31, which are the "first flow path" of the case 13 arranged in the vicinity of the nozzle 11. Therefore, the ink whose temperature decrease has been suppressed by the inlet 32 ​​and the liquid introduction chamber 31 can be guided to the nozzle 11, and ink whose viscosity has been reduced can be ejected from the nozzle 11.

[0080] Moreover, in the recording head 1 of the present embodiment, it is preferable that the heater 70 surrounds the second flow paths 50 in a plan view seen in the +Z direction, which is the "first direction", and overlaps at least a portion of the second flow paths 50 when seen in an in-plane direction including the ±X direction and the ±Y direction, which are directions perpendicular to the +Z direction. According to this, since the heater 70 is disposed so as to surround the second flow paths 50, the second flow paths 50 disposed away from the outer peripheral wall 46 of the holder 40 can also be efficiently heated by the heater 70. Furthermore, by disposing the heater 70 so as to surround the second flow paths 50, heat radiation from the holder 40 can be suppressed.

[0081] In the recording head 1 of the present embodiment, the second flow path 50 has a second portion 52, which is an "intersection portion" extending in a direction intersecting the +Z direction, which is the "first direction", and a third portion 53, which is a "communication portion" extending in the +Z direction and communicating the second portion 52 with the inlet 32 ​​and the introduction liquid chamber 31, which are the "first flow path" of the case 13, and it is preferable that the heater 70 is arranged to overlap the second portion 52 and the third portion 53 when viewed in a direction perpendicular to the +Z direction. By providing the second portion 52, which is an intersection portion, in the second flow path 50 in this manner, the flow path length of the second flow path 50 can be increased, and the ink flowing through the second flow path 50 can be effectively heated by the heater 70. In addition, since the heater 70 extends in the +Z direction from the second flow path 50, which is the "intersection portion", to the third portion 53, which is the "communication portion", the ink flowing through the second flow path 50 can be effectively heated by the heater 70.

[0082] In this embodiment, each of the multiple second flow paths 50 is provided with one second portion 52, which is an "intersection portion," and one third portion 53, which is a "communication portion." However, the present invention is not limited to this, and the second flow path 50 may be connected to two or more "first flow paths" by providing multiple second portions 52, which are "intersection portions," in the second flow path 50. In other words, the second flow path 50 may be a branch flow path for distributing liquid to two or more "first flow paths." In other words, the number of second flow paths 50 does not necessarily have to correspond one-to-one to the number of "first flow paths" as in this embodiment, and the holder 40 may be configured to have multiple second flow paths 50 that communicate with at least one "first flow path" among the multiple "first flow paths" of the multiple head chips 10 fixed to the holder 40.

[0083] In addition, in the recording head 1 of the present embodiment, the holder 40 has an outer peripheral wall 46 surrounding the multiple second flow paths 50 in a plan view seen in the +Z direction, which is the "first direction," and the heater 70 is a flexible film heater that is preferably wrapped around the entire circumference of the outer peripheral wall 46 in a plan view seen in the +Z direction and fixed to the outer peripheral wall 46. In this way, the heater 70 can be easily attached to the holder 40 by simply wrapping the flexible, long heater 70 around the outer peripheral wall 46 of the holder 40. In addition, since the heater 70 is wrapped around the entire circumference of the outer peripheral wall 46, the heat dissipation of the holder 40 can be suppressed and the holder 40 can be efficiently heated by the heater 70. Note that the heater 70 may be provided so as to cover the outer peripheral wall 46 over the +Z direction, or may be provided so as to cover only a part of the outer peripheral wall 46 in the +Z direction.

[0084] In addition, the recording head 1 of this embodiment has a plurality of exposure openings 61 that are openings for exposing the plurality of nozzles 11 of the head chip 10, and includes a fixed plate 60 made of metal, and the holder 40 has a lower wall 45 to which the plurality of head chips 10 and the fixed plate 60 are fixed, and the lower wall 45 preferably has a plurality of recesses 47 that accommodate each of the head chips 10. That is, the holder 40 is provided with recesses 47 corresponding to each of the plurality of head chips 10, and the partition walls 48 of the holder 40 are provided between the adjacent head chips 10. For this reason, the rigidity of the holder 40 can be improved and the deformation of the fixed plate 60 can be suppressed. In addition, by making the fixed plate 60 out of metal, the heat of the heater 70 can be transmitted through the lower wall 45 including the partition walls 48 to which the fixed plate 60 is fixed, and the holder 40 can be efficiently heated, thereby efficiently heating the plurality of head chips 10.

[0085] In this manner, in this embodiment, since the ink supplied to the head chip 10 can be heated by the heater 70 in the second flow path 50, ultraviolet curable ink or solvent-based ink can be used as the ink used in the recording head 1. In other words, ultraviolet curable ink and solvent-based ink have a relatively high viscosity at room temperature, but the viscosity of the highly viscous ink can be reduced by heating it with the heater 70, so that the deterioration of the ejection characteristics of the ink droplets can be suppressed.

[0086] The solvent-based ink is an ink whose main component is an organic solvent, and is also called a solvent ink or a non-aqueous ink. The solvent-based ink is an ink containing at least one of glycol ethers, glycol ether esters, dibasic acid esters, ester-based solvents, hydrocarbon-based solvents, and alcohol-based solvents. The ultraviolet-curable ink is, for example, a UV ink containing a monomer or oligomer that undergoes a polymerization reaction and hardens when irradiated with ultraviolet light. Examples of the ultraviolet-curable ink composition include inks containing any of (meth)acrylates, (meth)acrylamides, and N-vinyl compounds as polymerizable compounds.

[0087] Furthermore, the recording head 1 of this embodiment includes a head outer wall 84 disposed so as to sandwich the heater 70 between the head outer wall 84 and the holder 40, and the head outer wall 84 preferably has a lower thermal conductivity than the holder 40. According to this, by forming the head outer wall 84 from a material having a lower thermal conductivity than the holder 40, it is possible to suppress the heat of the heater 70 and the heat of the holder 40 heated by the heater 70 from being dissipated through the head outer wall 84. Therefore, there is no need to heat the heater 70 excessively, and it is possible to suppress a decrease in the life span of the components constituting the recording head 1, and it is also possible to easily manage the temperature of the ink flowing through the second flow path 50 by controlling the temperature of the heater 70.

[0088] In the above-described first embodiment, the amount of heat generated by the heater 70 is the same throughout the circumferential direction of the outer peripheral wall 46, but the present invention is not limited thereto. For example, the amount of heat generated per unit area of ​​the first portion 73 of the heater 70 may be greater than the amount of heat generated per unit area of ​​the second portion 74. The amount of heat generated per unit area in the first portion 73 and the second portion 74 of the heater 70 can be adjusted by changing, for example, the width of the heater pattern (wiring) of the heating resistor of the heating section 71 or the density per unit area where the heating resistor is provided. Specifically, the narrower the width of the heater pattern of the heating resistor of the heating section 71, the greater the amount of heat generated per unit area, and the higher the density of the heating resistor, the greater the amount of heat generated per unit area.

[0089] That is, the head chips 10 are arranged in a line in the +Y direction, which is a "third direction" perpendicular to the +Z direction, which is the "first direction", and the heater 70 has a first portion 73 extending in the +Y direction and a second portion 74 extending in a direction perpendicular to the +Z direction and intersecting the +Y direction, and the heat generation amount per unit area of ​​the first portion 73 is greater than the heat generation amount per unit area of ​​the second portion 74. Here, it is preferable that the juxtaposition direction of the second flow paths 50 coincides with the juxtaposition direction of the head chips 10. This makes it possible to easily handle the second flow paths 50, simplify the structure, and suppress the occurrence of variations in the flow path lengths of the second flow paths 50, thereby suppressing the occurrence of variations in the ejection characteristics of ink droplets between the head chips 10. In this way, when the second flow paths 50 are arranged in a line in the +Y direction, there is a variation in the distance from the outer peripheral wall 46 on both sides of the holder 40 in the ±Y direction between the second flow paths 50. On the other hand, when the second flow paths 50 are arranged in parallel in the +Y direction, the variation in the distance from the outer peripheral wall 46 on both sides of the holder 40 in the ±X direction is relatively small. That is, the variation in the distance from the second portion 74 of the heater 70 in the +Y direction is large for the second flow paths 50, and the variation in the distance from the first portion 73 in the +X direction is small. Therefore, by making the heat generation amount of the first portion 73 larger than that of the second portion 74, the variation in the temperature at which the second flow paths 50 in the holder 40 are heated can be reduced, and the variation in the heated temperature of the ink flowing through the second flow paths 50 can be reduced. That is, in the ±Y direction in which the head chips 10 are arranged in parallel, the ink in the second flow paths 50 that supplies ink to the head chip 10 arranged in the center is difficult to heat, but by increasing the heat generation amount of the first portion 73 extending in the +Y direction, the ink in the second flow paths 50 that supplies ink to the head chip 10 arranged in the center can be easily heated. Therefore, it is possible to reduce variations in the temperature to which the multiple second flow paths 50 in the holder 40 are heated.

[0090] In other words, the second flow paths 50 are arranged in a line in the +Y direction, which is a "third direction" perpendicular to the +Z direction, which is the "first direction", and the heater 70 has a first portion 73 extending in the +Y direction and a second portion 74 extending in a direction perpendicular to the +Z direction and intersecting the +Y direction, and the heat generation amount per unit area of ​​the first portion 73 is greater than the heat generation amount per unit area of ​​the second portion 74. This can reduce the variation in the temperature at which the second flow paths 50 in the holder 40 are heated. In this embodiment, the second flow paths 50 are arranged in a total of eight, with four second flow paths 50 arranged in the +Y direction and two second flow paths 50 arranged in the +Y direction, but the direction in which the second flow paths 50 are arranged in a line is the direction in which the number of second flow paths 50 is greater, that is, the +Y direction in this embodiment. This makes it possible to make the amount of heat generated in the first portion 73 extending in the direction in which the number of second flow paths 50 is greater than the amount of heat generated in the second portion 74 extending in the direction in which the number of second flow paths 50 is fewer, thereby reducing the variation in the heated temperature of the ink flowing through the multiple second flow paths 50.

[0091] In this embodiment, the holder 40 has a rectangular shape in plan view in the +Z direction, but is not particularly limited to this, and the holder 40 may have a shape with rounded corners based on a rectangular shape in plan view in the +Z direction. A modified example of the holder 40 is shown in Fig. 11. Fig. 11 is a top view showing a modified example of the holder 40 and the heater 70.

[0092] As shown in FIG. 11, when viewed in a plane in the +Z direction, three of the four corners 40a-40d of the holder 40 are chamfered to form rounded curved surfaces with curvature, known as R surfaces, and one corner 40d is a right angle that is not chamfered.

[0093] In order to wind the heater 70 around the outer peripheral wall 46 of the holder 40, both ends of the heater 70 may be joined at the corners 40d that are not chamfered. As a result, the heater 70 is curved along the curved surface at the corners 40a to 40c, so that bending is suppressed, and disconnection of the heat generating part 71 and peeling off from the outer peripheral wall 46 of the holder 40 can be suppressed. In addition, by making both ends of the heater 70 join at the corners 40d, the heater 70 can be arranged around the entire outer peripheral wall 46 of the heater 70, and the stress applied to both ends of the heater 70 in the direction in which they are peeled off from the holder 40 can be reduced, so that peeling off of the heater 70 from the holder 40 can be suppressed. Incidentally, if both ends of the heater 70 are joined on the sides of the outer peripheral wall 46 along the ±X direction or ±Y direction, the distance from the part bent by the corners 40a to 40d of the heater 70 to both ends of the heater 70 is shortened. For this reason, a force resisting bending of the heater 70 is applied to both ends of the heater 70 as a reaction force that pulls the heater 70 from the holder 40, making the both ends of the heater 70 more likely to peel off from the holder 40. Also, by arranging both ends of the heater 70 at the corners 40d, the both ends of the heater 70 can be placed farther away from the second flow paths 50 than when the both ends of the heater 70 are aligned on sides of the outer circumferential wall 46 along the ±X directions or ±Y directions, and therefore the heater 70 can effectively heat the multiple second flow paths 50.

[0094] Furthermore, by making the corners 40a to 40c of the holder 40 rounded, the overall length of the heater 70 wound around the outer peripheral wall 46 can be shortened, leading to cost reduction.

[0095] Here, the recording head 1 of the present embodiment described above is mounted on an inkjet recording apparatus I. The inkjet recording apparatus I, which is an example of a liquid ejecting apparatus of the present embodiment, will be described with reference to Figs. 12 and 13. Fig. 12 is a diagram showing a schematic configuration of the inkjet recording apparatus I, and Fig. 13 is a cross-sectional view of the main parts of the recording head 1 and a holding member 7.

[0096] As shown in FIG. 12, the ink jet recording apparatus I includes a recording head 1, a liquid container 3, a transport mechanism 4 that feeds out the medium S, a control unit 5 that is a control means, and a movement mechanism 6.

[0097] The liquid container 3 stores ink to be ejected from the recording head 1. Examples of the liquid container 3 include a cartridge that is detachable from the inkjet recording device I, a bag-shaped ink pack made of a flexible film, and an ink tank that can be refilled with ink. In this embodiment, a cartridge that is detachably provided on the recording head 1 is used as the liquid container 3. Furthermore, the liquid container 3 stores a plurality of different types of ink with different colors and types individually. In this embodiment, the liquid container 3 stores four colors of ink, namely cyan (C), fluorescent yellow (FY), fluorescent pink (FP), and black (K), individually.

[0098] Although not specifically shown, the control unit 5 includes, for example, a control device such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and a storage device such as a semiconductor memory. The control unit 5 comprehensively controls each element of the inkjet recording apparatus I, i.e., the transport mechanism 4, the movement mechanism 6, the recording head 1, etc., by the control device executing a program stored in the storage device.

[0099] The control unit 5 also controls the heater 70 to control the temperature of the ink flowing through the second flow path 50. The control unit 5 of this embodiment also controls the heater 70 based on the temperature measured by a temperature sensor (not shown) provided in the recording head 1. The temperature sensor is preferably provided in the holder 40 in which the second flow path 50 is provided so as to detect the temperature of the holder 40, in which the second flow path 50 is provided, although not particularly shown. For example, a recess may be provided in the central portion of the in-plane direction including the ±X direction and ±Y direction of the upper wall 44 of the holder 40, and the temperature sensor may be disposed in this recess. This makes it easy to obtain the temperature of the ink flowing through the second flow path 50 by the temperature sensor, and the temperature of the ink flowing through the second flow path 50 can be controlled with relatively high accuracy by the heater 70. Of course, the temperature sensor may be provided on the lower wall 45 side of the holder 40, but since the head chip 10 is fixed to the lower wall 45 side, there is a risk that the structure will become complicated and that it will be difficult to handle the wiring of the temperature sensor, so it is preferable to provide the temperature sensor on the upper wall 44 side. The temperature sensor may be provided on the relay board 90, on the holder cover 80, or on the fixed plate 60. The temperature sensor is not limited to a contact type, and may be a non-contact type.

[0100] In this embodiment, the control unit 5 that controls printing also controls the heater 70, but this is not particularly limited, and for example, a control means that controls the heater 70 may be provided separately from the control unit 5 that controls printing. Also, for example, by providing a temperature detection means such as a thermistor in the recording head 1, the temperature of the target may be detected and the control unit 5 may control the heater 70 so that the target is kept at a constant temperature.

[0101] The transport mechanism 4 is controlled by the control unit 5 to transport the medium S in the +X direction, and has, for example, a transport roller 4a. Note that the transport mechanism 4 that transports the medium S is not limited to the transport roller 4a, and may transport the medium S by a belt or a drum.

[0102] The movement mechanism 6 reciprocates the recording head 1 in the ±Y direction under the control of the control unit 5. The ±Y direction in which the recording head 1 is reciprocated by the movement mechanism 6 intersects with the +X direction in which the medium S is transported.

[0103] Specifically, the moving mechanism 6 of this embodiment includes a holding member 7 that holds the recording head 1, a conveyor belt 8, and a guide rail 9. The holding member 7 is a substantially box-shaped structure, a so-called carriage, that houses the recording head 1, and is fixed to the conveyor belt 8. The conveyor belt 8 is an endless belt that is stretched along the ±Y direction. Under the control of the control unit 5, the driving force of the drive motor 8a is transmitted to the conveyor belt 8, and the conveyor belt 8 rotates, so that the recording head 1 moves back and forth along the guide rail 9 in the ±Y direction together with the holding member 7. It is also possible to place the liquid container 3 in the device body 2 separately from the recording head 1.

[0104] 13, the holding member 7 is disposed with the head outer wall 84 sandwiched between it and the heater 70. The holding member 7 may be made of a metal such as stainless steel or titanium, or may be made of a resin. The resin constituting the holding member 7 may be, for example, the same material as that of the case 13 described above.

[0105] Here, the relationship between the temperatures of the second flow passage 50, the head outer wall 84, and the holding member 7 due to differences in the material of the holding member 7 will be described.

[0106] When the holding member 7 is made of a metal material, the thermal conductivity is higher than that of a resin material, so the temperature of the head outer wall 84 is more susceptible to the outside air temperature and is more likely to drop. On the other hand, when the holding member 7 is made of a resin material, the thermal conductivity is lower than that of a metal material, so the temperature of the head outer wall 84 is less susceptible to the outside air temperature and is less likely to drop. However, in this embodiment, regardless of the material of the holding member 7, the heater 70 surrounds the second flow paths 50, so the temperature of the ink flowing through the second flow paths 50 remains almost the same. However, since a metal material has a higher rigidity than that of a resin material, forming the holding member 7 from a metal material suppresses deformation of the holding member 7 and makes it less likely that the ink droplets will be ejected in a different direction due to deformation of the holding member 7. On the other hand, since a resin material has a lower thermal conductivity than that of a metal material, forming the holding member 7 from a resin material suppresses heat dissipation from the heater 70 and the holder 40, and allows the heater 70 to efficiently heat the holder 40. Furthermore, since resin materials are less expensive than metal materials, forming the holding member 7 from a resin material can reduce costs.

[0107] In this embodiment, a common heater 70 is provided for the multiple second flow paths 50 provided in the holder 40, and it is not necessary to provide a heater 70 for each second flow path 50, so that it is possible to suppress an increase in the number of parts and reduce costs, and also to simplify the structure and the routing of the wiring connected to the heater 70. Also, the recording head 1 can be made smaller.

[0108] As described above, the inkjet recording device I, which is an example of a liquid ejection device of this embodiment, comprises a recording head 1, which is the above-mentioned "liquid ejection head", and a holding member 7 made of metal that holds the recording head 1, and a portion of the holding member 7 is arranged so as to sandwich the head outer wall 84 between it and the heater 70.

[0109] In this way, by making the holding member 7 out of metal, the rigidity of the holding member 7 can be improved compared to when it is made of resin, and deformation of the holding member 7 can be suppressed. Therefore, it is possible to suppress the occurrence of deviation in the ejection direction of ink droplets due to deformation of the holding member 7. Furthermore, even if the holding member 7 is made of a metal with high thermal conductivity, the heater 70 can heat the second flow path 50 of the holder 40 provided on the opposite side to the holding member 7, so that it is possible to suppress the occurrence of insufficient heating of the ink flowing through the second flow path 50 and the occurrence of variation in temperature of the ink flowing through the multiple second flow paths 50.

[0110] Furthermore, an inkjet recording device I, which is an example of a liquid ejection device of this embodiment, is provided with a recording head 1, which is the above-mentioned "liquid ejection head", and a holding member 7 made of resin that holds the recording head 1, and a portion of the holding member 7 may be positioned so as to sandwich the head outer wall 84 between it and the heater 70.

[0111] In this way, by making the holding member 7 out of resin, the thermal conductivity of the holding member 7 can be made lower than when it is made out of metal, so heat dissipation from the heater 70 and the holder 40 can be suppressed and the holder 40 can be efficiently heated by the heater 70. Furthermore, by making the holding member 7 out of resin, costs can be reduced compared to when it is made out of metal.

[0112] The ink jet recording apparatus I of this embodiment includes the recording head 1, which is the above-mentioned "liquid ejection head," and a control unit 5, which is a control means for controlling the heater 70. The control unit 5 controls the heating temperature of the heater 70, thereby controlling the temperature of the ink in the second flow path 50 by the heater 70, and ink at an optimal temperature can be supplied to the head chip 10.

[0113] The inkjet recording apparatus I of this embodiment includes a recording head 1, which is the above-mentioned "liquid jet head," and a liquid container 3 that stores ink, which is the liquid to be jetted from the recording head 1. The ink, which is the liquid supplied from the liquid container 3, can be jetted from the recording head 1 to print on a medium S.

[0114] In this embodiment, the holding member 7 is arranged so that the head outer wall 84 is sandwiched between the heater 70, but this is not particularly limited. A modified example of the holding member 7 is shown in Fig. 14. Fig. 14 is a cross-sectional view showing the main parts of the recording head 1 and the holding member 7A.

[0115] 14, the holding member 7A is made of resin, and a part of the holding member 7A is disposed so as to sandwich the heater 70 between itself and the holder 40. Note that the resin constituting the holding member 7A may be, for example, the same material as that of the case 13 described above.

[0116] In this way, by making the holding member 7A out of resin and disposing a part of the holding member 7A so as to sandwich the heater 70 between it and the holder 40, the heater 70 can be covered with the holding member 7A, which has low thermal conductivity, and heat dissipation from the heater 70 and the holder 40 can be suppressed, allowing the heater 70 to efficiently heat the holder 40. Furthermore, by making the holding member 7A out of resin, costs can be reduced compared to when it is made out of metal.

[0117] (Embodiment 2) Fig. 15 is a cross-sectional view taken along line BB' of an ink jet recording head 1, which is an example of a "liquid jet head" according to a second embodiment of the present invention. Fig. 16 is a perspective view of a holder 40 and a heater 70 according to the second embodiment. Fig. 17 is a cross-sectional view taken along line CC' of the recording head 1. Note that the same members as those in the above-mentioned embodiments are given the same reference numerals and redundant explanations will be omitted.

[0118] As shown in FIG. 15, the recording head 1 of this embodiment includes a head chip 10, a holder 40, a fixing plate 60, a heater 70, a holder cover 80, and a relay board 90. As shown in FIG.

[0119] The holder 40 is provided with a second flow path 50. The second flow path 50 includes a first portion 51, a second portion 52, and a third portion 53, similar to the first embodiment described above.

[0120] In this embodiment, second portion 52 is disposed closer to upper wall 44 than head chip 10. Here, "second portion 52 is disposed closer to upper wall 44 than head chip 10" means that, in the +Z direction, center C1 of second portion 52 is disposed closer to upper wall 44 than center C2 between the bottom surface of recess 47 to which head chip 10 is fixed and the surface of upper wall 44 on the -Z direction side, as shown in Fig. 17. Also, it is more preferable that the minimum thickness h1 in the ±Z direction of the portion of upper wall 44 of first member 41 that defines second portion 52 is smaller than the maximum height h2 in the ±Z direction of second portion 52.

[0121] The heater 70 is disposed at a position overlapping the multiple second portions 52 in a plan view seen in the +Z direction. The heater 70 is also disposed on the upper wall 44 of the holder 40. That is, the heater 70 is disposed on the surface on the -Z direction side, which is the upper wall 44 of the holder 40, at a position overlapping the second portions 52 in a plan view seen in the +Z direction.

[0122] In this embodiment, the heater 70 is disposed so as to cover substantially the entire surface of the upper wall 44 of the holder 40 on the -Z direction side.

[0123] Such a heater 70 may be a film heater having flexibility, or may be a heater having no flexibility.

[0124] The heater 70 is provided with an opening 75 through which the protrusion 41a of the holder 40, i.e., the connection portion 51a of the second flow path 50, is inserted. The connection portion 51a is drawn out through the opening 75 to the -Z direction side beyond the heater 70.

[0125] Heater 70 is provided with a communication hole 76 that communicates with first wiring insertion hole 49. Wiring board 23 of head chip 10 is drawn out through communication hole 76 of heater 70 to the -Z side.

[0126] In this way, by providing the heater 70 on the upper wall 44 of the holder 40, the second flow paths 50 arranged in the vicinity of the head chip 10 can be heated by the heater 70, so that the head chip 10 can be supplied with sufficiently heated ink. In addition, since the holder 40 heated by the heater 70 is made of metal or ceramics with high thermal conductivity, the heater 70 can sufficiently heat the ink flowing through the multiple second flow paths 50, and sufficiently heated ink can be supplied to the head chip 10 arranged at a position away from the heater 70. Therefore, the viscosity of the ink ejected from the head chip 10 can be reduced, and the ink ejection characteristics can be suppressed from deteriorating. Furthermore, since the heater 70 is not configured to heat the head chip 10 itself, the configuration of the heater 70 and the configuration of the recording head 1 can be simplified.

[0127] Furthermore, in the recording head 1 of this embodiment, each of the multiple second flow paths 50 has a second portion 52 which is an "intersection portion" extending in a direction intersecting the first direction, the +Z direction, and the heater 70 is positioned at a position overlapping with the multiple second portions 52 when viewed in a plane in the +Z direction.

[0128] In this way, by positioning the heater 70 at a position overlapping with multiple second portions 52, the length of the flow path heated by the heater 70 can be increased, and the ink flowing through the second flow path 50 can be effectively heated.

[0129] In this embodiment, the second portion 52, which is the "intersection portion," is provided between the first member 41 and the second member 42, but this is not particularly limited, and the intersection portion may be provided between the second member 42 and the third member 43.

[0130] In addition, in this embodiment, each of the multiple second flow paths 50 is provided with one second portion 52 which is an "intersection portion" and one third portion 53 which is a "communication portion", but this is not particularly limited, and the second flow path 50 may be connected to two or more "first flow paths" by providing multiple second portions 52 which are "intersection portions" in the second flow path 50, that is, the second flow path 50 may be a branch flow path for distributing liquid to two or more "first flow paths". In other words, it is not necessary that the number of second flow paths 50 corresponds one-to-one to the number of "first flow paths" as in this embodiment, and the holder 40 may be configured to have multiple second flow paths 50 that communicate with at least one "first flow path" among the multiple "first flow paths" of the multiple head chips 10 fixed to the holder 40.

[0131] Furthermore, the heater 70 being disposed at a position overlapping the second portion 52 in a plan view seen in the +Z direction is not limited to the heater 70 being disposed on the upper wall 44 of the holder 40, and the heater 70 may be disposed between the first member 41 and the second member 42 constituting the holder 40, or between the second member 42 and the third member 43. Even if the heater 70 is disposed between the first member 41, the second member 42, and the third member 43, the ink flowing through the second portion 52 can be effectively heated by the heater 70 as long as the heater 70 is disposed at a position overlapping the second portion 52 in a plan view seen in the +Z direction. However, when the heater 70 is disposed on the upper wall 44, it is not necessary to incorporate the heater 70 between the laminated members constituting the holder 40 when assembling the holder 40, compared to when the heater 70 is disposed between the first member 41 and the second member 42, or between the second member 42 and the third member 43. Therefore, providing the heater 70 on the upper wall 44 makes it easier to manufacture the holder 40 and attach the heater 70 to the holder 40, as well as to route the wiring for the heater 70.

[0132] Moreover, in this embodiment, the holder 40 has an upper wall 44 provided on the -Z direction side, which is a second direction that is the opposite direction to the +Z direction, which is the first direction, of the holder 40, and the heater 70 is disposed on the upper wall 44. By disposing the heater 70 on the upper wall 44, the structure for installing the heater 70 is simplified compared to the case where the heater 70 is disposed on the lower wall 45, and the wiring for the heater 70 can be easily routed.

[0133] Furthermore, in this embodiment, second portion 52, which is the "intersection," is disposed closer to top wall 44 than head chip 10. In this manner, since second portion 52, which is the "intersection," is provided closer to top wall 44 on which heater 70 is provided, ink flowing through second portion 52 can be efficiently heated by heater 70. It is more preferable that the minimum thickness h1 in the ±Z directions of the portion of the upper wall 44 of the first member 41 that defines the second portion 52 is smaller than the maximum height h2 in the ±Z directions of the second portion 52. By making the minimum thickness h1 in the ±Z directions of the portion of the upper wall 44 of the first member 41 that defines the second portion 52 smaller than the maximum height h2 in the ±Z directions of the second portion 52 in this manner, the second portion 52 can be brought closer to the heater 70 provided on the surface of the upper wall 44 on the -Z direction side, making it easier for the heater 70 to heat the ink flowing through the second portion 52.

[0134] In this embodiment, the heater 70 is provided only on the upper wall 44, but this is not particularly limited. Modified examples of the heater 70 will now be described with reference to Figs. 18 and 19. Fig. 18 is a cross-sectional view of the recording head 1. Fig. 19 is a perspective view of the holder 40 and the heater 70.

[0135] 18 and 19, the holder 40 has a side wall. The side wall refers to one side of the outer peripheral wall 46.

[0136] The heater 70 is made of a flexible film heater. The heater 70 includes a main body portion 77 provided on the top wall 44, bent portions 78 provided on both side walls in the ±X directions, and bent portions 79 provided on both side walls in the ±Y directions. The bent portions 78, 79 are bent at the ends of the top wall 44 relative to the main body portion 77, and the main body portion 77 and the bent portions 78, 79 are provided integrally.

[0137] In this way, by providing the heater 70 integrally with the top wall 44 and the side wall of the holder 40, it is possible to suppress the occurrence of temperature variations in the entire holder 40 by the heater 70. Therefore, it is possible to suppress the occurrence of temperature variations in the ink flowing through the multiple second flow paths 50 heated by the heater 70.

[0138] In this embodiment, the bent portions 78 are provided on both side surfaces in the ±X directions and on both side surfaces in the ±Y directions, but the present invention is not limited to this, and only one of the bent portions 78 and the bent portions 79 may be provided. Furthermore, among the bent portions 78 provided on the side walls on both sides in the ±X directions, only one of the bent portion 78 provided on the side wall in the +X direction and the bent portion 78 provided on the side wall in the -X direction may be provided. Furthermore, among the bent portions 79 provided on the side walls on both sides in the ±Y directions, only one of the bent portion 79 provided on the side wall in the +Y direction and the bent portion 79 provided on the side wall in the -Y direction may be provided.

[0139] As described above, in the recording head 1 of this embodiment, the holder 40 has side walls, and the heater 70 is a flexible film heater having a main body portion 77 fixed to the top wall 44, and folded portions 78, 79 bent at the end of the top wall 44 relative to the main body portion 77 and fixed to the side walls.

[0140] By providing the heater 70 integrally with the top wall 44 and the side wall of the holder 40 in this manner, it is possible to suppress the occurrence of temperature variations in the entire holder 40 by the heater 70 while heating. Therefore, it is possible to suppress the occurrence of temperature variations in the ink flowing through the multiple second flow paths 50 heated by the heater 70. Also, since it is possible to form bent portions 78, 79 fixed to the side walls simply by bending the end portion of the top wall 44 relative to the main body portion 77 of the heater 70, it is possible to efficiently heat the second flow paths 50 with a simple film heater configuration.

[0141] In the recording head 1 of the present embodiment, each of the second flow paths 50 preferably has a connection portion 51a protruding from the upper wall 44 of the holder 40 in the -Z direction, which is the "second direction" opposite to the +Z direction, and the heater 70 preferably has openings 75, which are a plurality of openings through which the connection portions 51a are inserted. According to this, even if the connection portions 51a protrude from the upper wall 44 of the holder 40 in the -Z direction, the heater 70 can be easily attached to the holder 40 because the heater 70 has the openings 75 corresponding to the connection portions 51a. In addition, by providing the openings 75 in the heater 70, the heater 70 can be disposed near the connection portions 51a and the second flow paths 50 communicating with the connection portions 51a, for example, the first portion 51 or the second portion 52, so that heating by the heater 70 can be performed efficiently. It is also possible to configure the heater 70 without providing the opening 75, and to divide the heater 70 into multiple parts and place them on the upper wall 44 so as to avoid the connection portion 51a. In that case, however, there is a risk that the number of parts such as the heater 70 will increase and the configuration will become complicated.

[0142] (Other embodiments) Although each embodiment of the present invention has been described above, the basic configuration of the present invention is not limited to the above.

[0143] In each of the above-described embodiments, the inlet 32 ​​and the introduction liquid chamber 31 for supplying ink into the head chip 10 are exemplified as the "first flow path" provided in the head case 13, but the present invention is not particularly limited thereto, and the head chip 10 may include, as the "first flow path", a discharge path for discharging ink from the head chip 10 to the outside, a circulation path for circulating ink between the head chip 10 and the liquid container 3, or the like. Similarly, in each of the above-described embodiments, the second flow path 50 of the holder 40 is exemplified as one for supplying ink to the head chip 10, but the present invention is not particularly limited thereto, and the holder 40 may include, as the second flow path 50, a discharge path for further discharging ink discharged from the head chip 10 to the outside, a circulation path for circulating ink between the head chip 10 and the liquid container 3, or the like.

[0144] For example, in each of the above-described embodiments, the holder 40 is exemplified as being composed of three members, the first member 41, the second member 42, and the third member 43, but the present invention is not limited to this, and the holder 40 may be composed of a single member, or may be composed of two or more members. In addition, the stacking direction of the multiple members constituting the holder 40 is not limited to the +Z direction, and the members may be stacked in the +X direction or +Y direction, etc. However, when the second portion 52, which is an "intersection portion", is provided in the second flow path 50, stacking multiple members in the +Z direction is preferable because it is easier to form the second portion 52.

[0145] The energy generating element of the head chip 10 is not limited to the piezoelectric actuator 18, and various known configurations can be used. For example, the energy generating element that generates pressure fluctuations in the ink in the pressure chamber 19 can be, for example, an element that changes the volume of the flow path by deformation of a piezoelectric actuator having a piezoelectric material that exhibits an electromechanical conversion function, thereby causing a pressure change in the ink in the flow path and ejecting ink droplets from the nozzle 11. The energy generating element can also be an element that has a heating element disposed in the flow path and ejects ink droplets from the nozzle 11 by bubbles generated by the heat generated by the heating element. Furthermore, the energy generating element can be, for example, a so-called electrostatic actuator that generates an electrostatic force between a vibration plate and an electrode, deforms the vibration plate by the electrostatic force, and ejects ink droplets from the nozzle 11.

[0146] In addition, in each of the above-described embodiments, a configuration has been exemplified in which the nozzles 11 are arranged in the +X direction, which is the same as the transport direction of the medium S, but is not particularly limited to this. For example, as shown in Fig. 20, the nozzles 11 may be arranged in a slanted manner with respect to the +X direction, which is the transport direction of the medium S.

[0147] In addition, in each of the above-described embodiments, a configuration in which a plurality of head chips 10 are arranged in the +Y direction so that the positions in the +X direction are the same has been exemplified, but the present invention is not particularly limited to this. For example, as shown in FIG. 21, a plurality of head chips 10 may be arranged in a staggered manner along the +X direction. Here, arranging a plurality of head chips 10 in a staggered manner along the +X direction means arranging the head chips 10 arranged in parallel in the +X direction by shifting them alternately in the Y direction. That is, two rows of head chips 10 arranged in parallel in the +X direction are arranged in parallel in the +Y direction, and the two rows of head chips 10 are arranged with a half pitch shift in the +X direction. By arranging the head chips 10 in a staggered manner along the +X direction in this way, the nozzles 11 of the two head chips 10 are partially overlapped to form a row of nozzles 11 that is continuous across the +X direction.

[0148] For example, in a head module having a plurality of recording heads 1 not provided with heaters 70 in the above-mentioned first and second embodiments, and a holding member provided with a flow path, for example, a branch flow path, that holds the plurality of recording heads 1 and supplies ink to the plurality of recording heads, if the recording heads 1 are read as head chips and the holding member as a holder, the present invention can also be applied to the head module. That is, in the head module, a heater may be provided in the holding member that corresponds to the holder.

[0149] In addition, in each of the above-described embodiments, the protrusion 41a is provided so as to protrude from the upper wall 44, but it may be configured so as to protrude from a side wall.

[0150] In addition, in the above-mentioned ink jet recording device I, the recording head 1 is mounted on the holding member 7 and moves in the ±Y direction, which is the main scanning direction, but the present invention is not limited to this. For example, the present invention can be applied to a so-called line-type recording device in which multiple recording heads 1 are arranged in a direction perpendicular to the transport direction of the medium S and fixed to a unit base, and printing is performed by simply moving the medium S in the transport direction. In this case, too, if the recording head 1 is read as a head chip, the flow path structure that distributes liquid to the multiple recording heads 1 is read as a holder, and the unit base is read as a holding member, the present invention can be applied by providing a heater in the flow path structure corresponding to the holder. Of course, if each of the recording heads 1 has a configuration having multiple head chips, the present invention may be applied to each of the recording heads 1.

[0151] In the above embodiment, an ink jet recording head is used as an example of a liquid jet head, and an ink jet recording device is used as an example of a liquid jet device, but the present invention is intended for a wide range of liquid jet heads and liquid jet devices in general, and can of course be applied to liquid jet heads and liquid jet devices that jet liquids other than ink. Other liquid jet heads include, for example, various recording heads used in image recording devices such as printers, color material jet heads used in manufacturing color filters for liquid crystal displays, electrode material jet heads used in forming electrodes for organic EL displays, FEDs (field emission displays), and bioorganic material jet heads used in biochip manufacturing, and can also be applied to liquid jet devices equipped with such liquid jet heads. [Explanation of symbols]

[0152] I...inkjet recording device (liquid ejection device), 1...inkjet recording head (liquid ejection head), 2...device body, 3...liquid container, 4...transport mechanism, 4a...transport roller, 5...control unit, 6...movement mechanism, 7...holding member, 8...transport belt, 8a...driving motor, 9...guide rail, 10...head chip, 11...nozzle, 12...nozzle plate, 13...case, 14...connecting plate, 15...pressure chamber forming substrate, 16...diaphragm, 17...compliance substrate, 17a...sealing film, 17b...fixed substrate, 17c...opening for fixed substrate, 17d...compliance section, 18...piezoelectric actuator, 19...pressure chamber, 20...first electrode, 21...piezoelectric layer, 22...second electrode, 23...wiring substrate, 24...wiring, 25...driving circuit, 26...nozzle connection port, 27...common liquid chamber, 28...individual connection port, 29... Protective substrate, 30...holding portion, 31...introducing liquid chamber, 32...introduction port, 33...wire insertion hole, 40...holder, 40a-40d...corner portion, 41...first member, 41a...projection portion, 42...second member, 43...third member, 43a...convex portion, 44...upper wall, 45...lower wall, 46...outer peripheral wall, 47...recess, 48...partition wall, 49...first wire insertion hole, 50...second flow path, 51...first portion, 51a...connection portion, 52...second portion, 53... Third portion, 60...fixing plate, 61...exposure opening, 70...heater, 71...heat generating portion, 72...film member, 73...first portion, 74...second portion, 75...opening, 76...communication hole, 77...main body portion, 78, 79...bent portion, 80...holder cover, 81...accommodating portion, 82...first through hole, 83...second wiring insertion hole, 84...head outer wall, 90...relay board, 91...third wiring insertion hole, 92...second through hole, S...medium

Claims

1. a nozzle plate having a plurality of nozzles for ejecting liquid in a first direction; and a case in which one or more first flow paths communicating with at least some of the nozzles are formed; a holder to which the plurality of head chips are fixed and which is made of metal or ceramics, the holder having a plurality of second flow paths which are in communication with at least one of the plurality of first flow paths; A heater for heating the holder; Equipped with the holder has an outer circumferential wall surrounding the second flow paths in a plan view, The liquid ejecting head, wherein the heater is fixed to the outer peripheral wall.

2. The liquid jet head according to claim 1 , wherein the heater surrounds all of the second flow paths in a plan view and overlaps with at least a portion of the second flow paths when viewed in a direction perpendicular to the first direction.

3. a nozzle plate having a plurality of nozzles for ejecting liquid in a first direction; and a case in which one or more first flow paths communicating with at least some of the nozzles are formed; a holder to which the plurality of head chips are fixed and which is made of metal or ceramics, the holder having a plurality of second flow paths which are in communication with at least one of the plurality of first flow paths; A heater for heating the holder; Equipped with The liquid jet head, wherein the heater surrounds all of the second flow paths in a plan view and overlaps with at least a portion of the second flow paths when viewed in a direction perpendicular to the first direction.

4. The second flow path is An intersection portion extending in a direction intersecting the first direction; a communication portion extending in the first direction and communicating the intersection portion with the first flow path of the case; having The liquid jet head according to claim 2 , wherein the heater is disposed so as to overlap the intersection portion and the communication portion when viewed in a direction perpendicular to the first direction.

5. The liquid jet head according to claim 1 , wherein the heater is flexible, wrapped around the outer peripheral wall so as to cover the entire periphery of the outer peripheral wall in a plan view, and fixed to the outer peripheral wall.

6. The plurality of head chips are arranged side by side in a third direction perpendicular to the first direction, The heater is A first portion extending in the third direction; a second portion extending in a direction perpendicular to the first direction and intersecting the third direction; having The liquid jet head according to claim 5 , wherein the amount of heat generated per unit area of ​​the first portion is greater than the amount of heat generated per unit area of ​​the second portion.

7. a nozzle plate having a plurality of nozzles for ejecting liquid in a first direction; and a case in which one or more first flow paths communicating with at least some of the nozzles are formed; a holder to which the plurality of head chips are fixed and which is made of metal or ceramics, the holder having a plurality of second flow paths which are in communication with at least one of the plurality of first flow paths; A heater for heating the holder; Equipped with Each of the second flow paths has an intersecting portion extending in a direction intersecting the first direction, the heater is disposed at a position overlapping with the plurality of intersections in a plan view seen in the first direction, the holder has an upper wall provided on a second direction side of the holder, the second direction being opposite to the first direction; The liquid ejecting head is characterized in that the heater is disposed on the upper wall.

8. The liquid jet head according to claim 7 , wherein a minimum thickness in the first direction of a portion of the upper wall that defines the intersection portion is smaller than a maximum height in the first direction of the intersection portion.

9. the second flow passage includes a communication portion that extends in the first direction and communicates the intersection portion with the first flow passage of the case, a length of the communication portion in the first direction is longer than a height of the intersection portion in the first direction; The liquid jet head according to claim 7 , wherein the intersecting portion is disposed closer to the upper wall than the head tip.

10. The holder has a side wall. The heater is It has flexibility, A main body portion fixed to the upper wall; a bent portion bent at an end of the upper wall relative to the main body portion and fixed to the side wall; The liquid jet head according to any one of claims 7 to 9, further comprising:

11. 11. The liquid jet head according to claim 5, wherein the heater is a film heater.

12. Each of the second flow paths has a connection portion protruding from the upper wall of the holder in a second direction opposite to the first direction, 11. The liquid jet head according to claim 7, wherein the heater has a plurality of openings through which the plurality of connection portions are inserted, respectively.

13. a plurality of head chips each having a nozzle plate having a plurality of nozzles that eject liquid in a first direction and a case in which one or more first flow paths communicating with at least some of the plurality of nozzles are formed; a holder to which the plurality of head chips are fixed and which is made of metal or ceramics, the holder having a plurality of second flow paths which are in communication with at least one of the plurality of first flow paths; A heater for heating the holder; Equipped with the holder has an upper wall provided on a second direction side of the holder, the second direction being opposite to the first direction; The heater covers substantially the entire surface of the upper wall.

14. The liquid jet head according to claim 13 , wherein the heater covers all of the plurality of head chips.

15. A plurality of head chips each having a nozzle plate having a plurality of nozzles for spraying liquid in a first direction, and a case in which one or more first flow paths communicating with at least a portion of the plurality of nozzles are formed; a holder to which the plurality of head chips are fixed and which is made of metal or ceramics, the holder having a plurality of second flow paths which are in communication with at least one of the plurality of first flow paths; A heater for heating the holder; Equipped with The liquid ejecting head is characterized in that the heater covers all of the plurality of head chips.

16. The holder is configured by stacking a plurality of members in the first direction, Each of the second flow paths has an intersecting portion extending in a direction intersecting the first direction, the heater is disposed at a position overlapping with the plurality of intersections in a plan view seen in the first direction.

16. The liquid jet head according to claim 13, wherein the liquid jet head is a liquid jet head.

17. A plurality of head chips each having a nozzle plate having a plurality of nozzles for spraying liquid in a first direction, and a case in which one or more first flow paths communicating with at least a portion of the plurality of nozzles are formed; a holder to which the plurality of head chips are fixed and which is made of metal or ceramics, the holder having a plurality of second flow paths which are in communication with at least one of the plurality of first flow paths; A heater for heating the holder; Equipped with The holder is configured by stacking a plurality of members in the first direction, Each of the second flow paths has an intersecting portion extending in a direction intersecting the first direction, the heater is disposed at a position overlapping with the plurality of intersections in a plan view seen in the first direction. A liquid jet head comprising:

18. the heater is provided between two adjacent members among the plurality of members stacked in the first direction to configure the holder; The liquid jet head according to claim 16 or 17, without citing claim 13.

19. A plurality of head chips each having a nozzle plate having a plurality of nozzles for spraying liquid in a first direction, and a case in which one or more first flow paths communicating with at least a portion of the plurality of nozzles are formed; a holder to which the plurality of head chips are fixed and which is made of metal or ceramics, the holder having a plurality of second flow paths which are in communication with at least one of the plurality of first flow paths; A heater for heating the holder; Equipped with The liquid ejecting head, wherein the heater overlaps with all of the head chips when viewed in the first direction.

20. a fixing plate having a plurality of openings for exposing the plurality of nozzles of the head chip and made of metal; the holder has a bottom wall to which the head chips and the fixing plate are fixed, 20. The liquid jet head according to claim 1, wherein the lower wall has a plurality of recesses for accommodating the plurality of head chips, respectively.

21. 21. The liquid jet head according to claim 1, wherein the case is made of resin.

22. a head outer wall disposed so as to sandwich the heater between the head outer wall and the holder, 22. The liquid jet head according to claim 1, wherein the head outer wall has a lower thermal conductivity than the holder.

23. The liquid jet head according to claim 22, a holding member made of metal and holding the liquid ejection head; Equipped with A liquid ejecting apparatus, comprising: a portion of the holding member disposed so as to sandwich the head outer wall between the portion and the heater.

24. The liquid jet head according to claim 22, a holding member made of resin and holding the liquid ejection head; Equipped with A liquid ejecting apparatus, comprising: a portion of the holding member disposed so as to sandwich the head outer wall between the portion and the heater.

25. A liquid jet head according to any one of claims 1 to 21, a holding member made of resin and holding the liquid ejection head; Equipped with A liquid ejecting apparatus, comprising: a part of the holding member disposed so as to sandwich the heater between the part and the holder.

26. A liquid jet head according to any one of claims 1 to 22, A control means for controlling the heater; A liquid ejection apparatus comprising:

27. A liquid jet head according to any one of claims 1 to 22, a liquid container that stores a liquid to be ejected from the liquid ejection head; A liquid ejection apparatus comprising:

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