Liquid jet head and liquid jet device

Abstract

To provide a liquid jet head and a liquid jet device which can efficiently heat a liquid in a head chip, can stably jet a liquid, and reduce cost.SOLUTION: A liquid jet head includes one or a plurality of head chips Hc for jetting a liquid in a jet direction, a flow channel member 220 for defining a flow channel for supplying a liquid to the one or plurality of head chips Hc and flowing the liquid therein, a holder 230 for holding the one or plurality of head chips Hc, and a heater 260 for heating the holder 230, wherein the holder 230 does not define the flow channel flowing the liquid therein, and is a heat conductive resin containing a heat conductive filler.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head that ejects liquid from nozzles and a liquid ejection apparatus. [Background technology]

[0002] 2. Description of the Related Art Liquid ejection apparatuses including a liquid ejection head that ejects liquid such as ink, such as ink jet printers, are known in the art.

[0003] A configuration has been disclosed in which the liquid in a head chip is heated by externally heating a liquid ejection head having a holder that holds multiple head chips that eject liquid and forms a flow path that supplies liquid to the head chips (see, for example, Patent Document 1).

[0004] Furthermore, Patent Document 1 discloses a configuration in which the holder is made of metal or ceramics with high thermal conductivity, making it easier to transfer heat from the heater to the head chip via the holder. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-132790 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the holder is made of metal or ceramics with high thermal conductivity, there is a problem in that the manufacturing cost increases. [Means for solving the problem]

[0007] An aspect of the present invention that solves the above problem is a liquid ejection head comprising one or more head chips that eject liquid in a jetting direction, a flow path member that defines a flow path through which liquid flows to supply liquid to the one or more head chips, a holder that holds the one or more head chips, and a heater that heats the holder, wherein the holder does not define a flow path through which liquid flows and is made of a thermally conductive resin that contains a thermally conductive filler.

[0008] Another aspect of the present invention is a liquid ejection apparatus comprising: the liquid ejection head according to the above aspect; and a liquid storage section that stores liquid to be supplied to the liquid ejection head. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing a schematic configuration of a liquid ejecting apparatus according to a first embodiment. [Diagram 2] 1 is an exploded perspective view of a liquid jet head according to a first embodiment. [Diagram 3] 1 is a cross-sectional view of a liquid jet head according to a first embodiment. [Figure 4] FIG. 2 is a plan view of the holder according to the first embodiment. [Diagram 5] 1 is a cross-sectional view of a head chip according to a first embodiment. [Figure 6] FIG. 1 is a cross-sectional view of a heater according to a first embodiment. [Figure 7] FIG. 1 is a plan view of a heater according to a first embodiment. [Figure 8] FIG. 4 is a plan view of a modified example of the heater according to the first embodiment. [Figure 9] FIG. 2 is a schematic diagram showing a heater and an intermediate substrate according to the first embodiment. [Figure 10] 5 is a schematic diagram showing a modified example of the heater and intermediate substrate according to the first embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 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 the X direction, the Y direction, and the Z direction. The direction in which the arrow in each drawing points is the positive (+) direction, and the opposite direction to the arrow is the negative (-) direction. In addition, the directions of the three spatial axes that are not limited to the positive and negative directions are described as the X-axis direction, the Y-axis direction, and the Z-axis direction. In addition, viewing along the Z-axis direction is called "planar view."

[0011] (Embodiment 1) FIG. 1 is a diagram showing a schematic configuration of a liquid ejecting apparatus 1 according to a first embodiment of the present invention.

[0012] 1, the liquid ejecting device 1 is a so-called serial printer that includes a liquid ejecting head H and prints by ejecting liquid from the liquid ejecting head H toward the medium S in the +Z direction while transporting the medium S in the X-axis direction and reciprocating the liquid ejecting head H in the Y-axis direction. Note that the medium S can be made of any material, such as cloth, recording paper, or a resin film.

[0013] Such a liquid ejecting device 1 includes a liquid ejecting head H, a liquid storage section 3, a control unit 4 which is a control section, a transport mechanism 5 which feeds out the medium S, and a moving mechanism 6.

[0014] The liquid ejection head H ejects liquid supplied from a liquid storage unit 3 that stores the liquid as droplets in the +Z direction.

[0015] The liquid storage section 3 individually stores a plurality of types of liquids having different colors and components to be ejected from the liquid ejection head H. Examples of the liquid storage section 3 include a cartridge that can be attached to and detached from the liquid ejection device 1, a bag-shaped ink pack formed of a flexible film, and an ink tank that can be refilled with ink. FIG. 1 illustrates one liquid storage section 3. Incidentally, the liquid storage section 3 may be a liquid storage section 3 having separate chambers that individually store a plurality of types of liquid, or may be a plurality of liquid storage sections 3 that are individually provided according to the plurality of types of liquid. The liquid storage section 3 may be divided into a main tank and a sub-tank. The sub-tank may be connected to the liquid ejection head H, and the liquid consumed by ejecting droplets from the liquid ejection head H may be refilled from the main tank to the sub-tank.

[0016] The control unit 4 comprehensively controls each element of the liquid ejecting device 1, that is, the liquid ejecting head H, the transport mechanism 5, the moving mechanism 6, and the like.

[0017] The transport mechanism 5 transports the medium S in the X-axis direction and has a transport roller 5a. The transport mechanism 5 transports the medium S in the X-axis direction by rotating the transport roller 5a. The transport roller 5a rotates by driving a transport motor (not shown). The control unit 4 controls the transport of the medium S by controlling the driving of the medium transport motor. Note that the transport mechanism 5 that transports the medium S is not limited to one having the transport roller 5a, and may transport the medium S by, for example, a belt or a drum.

[0018] The movement mechanism 6 is a mechanism for reciprocating the liquid ejection head H in the Y-axis direction, and includes a holder 7 and a conveyor belt 8. The holder 7 is a so-called carriage that holds the liquid ejection head H, and is fixed to the conveyor belt 8. The conveyor belt 8 is an endless belt that is installed along the Y-axis direction. The conveyor belt 8 rotates by driving a conveyor motor (not shown). The control unit 4 controls the driving of the conveyor motor to rotate the conveyor belt 8, and moves the liquid ejection head H back and forth together with the holder 7 in the Y-axis direction. The holder 7 may be configured to mount a liquid storage unit 3 together with the liquid ejection head H.

[0019] The liquid ejection head H performs an ejection operation of ejecting the liquid supplied from the liquid storage section 3 as droplets from each of the multiple nozzles 21 (see FIG. 5) in the +Z direction under the control of the control unit 4. This ejection operation by the liquid ejection head H is performed in parallel with the transport of the medium S by the transport mechanism 5 and the reciprocating movement of the liquid ejection head H by the movement mechanism 6, thereby applying the liquid to the medium S, i.e., performing so-called printing.

[0020] Fig. 2 is an exploded perspective view of the liquid jet head H. Fig. 3 is a cross-sectional view of the liquid jet head H. Fig. 4 is a plan view of the holder 230 as viewed in the -Z direction. Note that each direction of the liquid jet head H will be described based on the directions when it is mounted on the liquid jet device 1, that is, the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0021] As shown in the figure, the liquid jet head H includes multiple head chips Hc (two in this embodiment), a first flow path unit 200, a relay substrate 210, a second flow path unit 220, a holder 230, a cover head 240, a sealing member 250, and a heater 260.

[0022] 5 is a cross-sectional view showing an example of the head chip Hc. Note that the directions of the head chip Hc will be described based on the directions when the head chip Hc is mounted on the liquid jet head H, that is, the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0023] As shown in the figure, the head chip Hc comprises a flow path forming substrate 10, a communicating plate 15, a nozzle plate 20 having a plurality of nozzles 21 formed therein, a protective substrate 30, a case member 40, a piezoelectric actuator 300, and a first flexible substrate 110.

[0024] The flow path forming substrate 10 is made of, for example, a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates. In the flow path forming substrate 10, a plurality of pressure chambers 12 are arranged in line along the X-axis direction. The plurality of pressure chambers 12 are arranged on a straight line along the X-axis direction so as to be at the same position in the Y-axis direction. In this embodiment, two pressure chamber rows in which the pressure chambers 12 are arranged in line along the X-axis direction are provided in the Y-axis direction. The pressure chambers 12 constituting these two pressure chamber rows are arranged at the same position in the X-axis direction. The two pressure chamber rows may be arranged with a half pitch of the pressure chambers 12, that is, a so-called half pitch, shifted from each other in the X-axis direction. In other words, all the pressure chambers 12 in the two pressure chamber rows may be arranged in a staggered manner along the X-axis direction.

[0025] A communication plate 15 and a nozzle plate 20 are laminated in this order on a surface of the flow path forming substrate 10 facing the +Z direction. A vibration plate 50 and a piezoelectric actuator 300 are laminated in this order on a surface of the flow path forming substrate 10 facing the -Z direction.

[0026] The communication plate 15 is made of a plate-like member bonded to the surface of the flow passage forming substrate 10 facing the +Z direction. The communication plate 15 is provided with a nozzle communication passage 16 that communicates between the pressure chambers 12 and the nozzles 21. The communication plate 15 is also provided with a first manifold portion 17 and a second manifold portion 18 that constitute a part of a manifold 100 that serves as a common liquid chamber to which the multiple pressure chambers 12 are commonly communicated. The first manifold portion 17 is provided penetrating the communication plate 15 in the Z-axis direction. The second manifold portion 18 is provided opening on the surface facing the +Z direction without penetrating the communication plate 15 in the Z-axis direction. The communication plate 15 is also provided with supply communication passages 19 that communicate with the pressure chambers 12, independently of each other, in the communication plate 15. The supply communication passages 19 communicate between the second manifold portion 18 and the pressure chambers 12, and supply the ink in the manifold 100 to the pressure chambers 12. As such a communication plate 15, a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, a metal substrate such as a stainless steel substrate, or the like can be used.

[0027] The nozzle plate 20 is bonded to the side of the communication plate 15 opposite to the flow passage forming substrate 10, that is, the surface facing the +Z direction. In the nozzle plate 20, a plurality of nozzles 21 are formed to communicate with each pressure chamber 12 via the nozzle communication passage 16. In this embodiment, a plurality of nozzles 21 are arranged in a line along the X-axis direction for each pressure chamber row. That is, in this embodiment, two nozzle rows in which the nozzles 21 are arranged in parallel along the X-axis direction are provided at a distance in the Y-axis direction. The nozzles 21 constituting these two nozzle rows are arranged so as to be at the same position in the X-axis direction. Of course, when the two pressure chamber rows are arranged at positions shifted from each other by a half pitch of the pressure chambers 12 in the X-axis direction, the two nozzle rows may also be similarly arranged to be shifted from each other by a half pitch of the nozzles 21 in the X-axis direction. That is, all the nozzles 21 in the two nozzle rows may be arranged in a staggered manner along the X-axis direction.

[0028] A silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, a metal substrate such as a stainless steel substrate, an organic substrate such as a polyimide resin, etc. are used as the nozzle plate 20. The surface of the nozzle plate 20 facing the +Z direction constitutes a part of the ejection surface of the liquid ejection head H.

[0029] In this embodiment, the vibration plate 50 has an elastic film 51 made of silicon oxide provided on the flow path forming substrate 10 side, and an insulating film 52 made of zirconium oxide provided on the surface facing the -Z direction of the elastic film 51. The vibration plate 50 may be composed of only the elastic film 51, or may be composed of only the insulating film 52, or may have a configuration including other films in addition to the elastic film 51 and the insulating film 52.

[0030] The piezoelectric actuator 300 includes a first electrode 60, a piezoelectric layer 70, and a second electrode 80, which are sequentially stacked on the vibration plate 50 toward the -Z direction. Such a piezoelectric actuator 300 is also called a piezoelectric element, and refers to a portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. In addition, a portion where a piezoelectric strain occurs in the piezoelectric layer 70 when a voltage is applied between the first electrode 60 and the second electrode 80 is called an active portion 310. That is, the active portion 310 refers to a portion where the piezoelectric layer 70 is sandwiched between the first electrode 60 and the second electrode 80. In this embodiment, an active portion 310 is formed for each pressure chamber 12. The multiple active portions 310 are "driving elements" that cause a pressure change in the ink in the pressure chamber 12. In general, one of the electrodes of the active portion 310 is an individual electrode independent of each active portion 310, and the other electrode is configured as a common electrode common to the multiple active portions 310. In this embodiment, the first electrode 60 is separated for each active portion 310 to form an individual electrode for the active portion 310, and the second electrode 80 is provided continuously across the multiple active portions 310 to form a common electrode for the multiple active portions 310. Of course, the first electrode 60 may form a common electrode, and the second electrode 80 may form an individual electrode.

[0031] The piezoelectric layer 70 is formed, for example, using a piezoelectric material made of a complex oxide having a perovskite structure represented by the general formula ABO3.

[0032] Further, an individual lead electrode 91, which is a lead wiring, is drawn out from the first electrode 60. Further, a common lead electrode, which is a lead wiring (not shown), is drawn out from the second electrode 80. A first flexible substrate 110 having flexibility is connected to the ends of the individual lead electrode 91 and the common lead electrode opposite to the ends connected to the piezoelectric actuator 300. The first flexible substrate 110 is mounted with a drive signal selection circuit 111 having a plurality of switching elements for selecting whether or not to supply a drive signal COM for driving each of the active parts 310 to each of the active parts 310. That is, the first flexible substrate 110 in this embodiment is a COF (Chip On Film). It is not necessary to provide the drive signal selection circuit 111 on the first flexible substrate 110. That is, the first flexible substrate 110 may be an FFC (Flexible Flat Cable), an FPC (Flexible Printed Circuits), or the like.

[0033] A protective substrate 30 having approximately the same size as the flow path forming substrate 10 is bonded to the surface of the flow path forming substrate 10 facing the -Z direction. The protective substrate 30 has a storage section 31 which is a space for protecting the piezoelectric actuator 300. The storage section 31 is provided independently for each row of the piezoelectric actuators 300 arranged in the X-axis direction, and two storage sections 31 are formed side by side in the Y-axis direction. In addition, the protective substrate 30 is provided with a through hole 32 penetrating in the Z-axis direction between the two storage sections 31 arranged side by side in the Y-axis direction. The ends of the individual lead electrodes 91 and the common lead electrode (not shown) drawn from the electrodes of the piezoelectric actuators 300 extend so as to be exposed in the through hole 32, and the individual lead electrodes 91 and the common lead electrode are electrically connected to the first flexible substrate 110 in the through hole 32. As the protective substrate 30, for example, a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, etc. are used as in the flow path forming substrate 10.

[0034] Moreover, a case member 40 is fixed on the protective substrate 30, which defines a part of a manifold 100 communicating with the multiple pressure chambers 12. The case member 40 has substantially the same shape as the above-mentioned communicating plate 15 in a plan view, and is joined to the protective substrate 30 and also to the above-mentioned communicating plate 15. Such a case member 40 has a recess 41 on the protective substrate 30 side, the recess 41 having a depth for accommodating the flow passage forming substrate 10 and the protective substrate 30. The case member 40 is also provided with a third manifold portion 42 communicating with the first manifold portion 17 of the communicating plate 15. The first manifold portion 17 and the second manifold portion 18 provided on the communicating plate 15 and the third manifold portion 42 provided on the case member 40 constitute the manifold 100 of this embodiment. The manifold 100 is provided for each nozzle row. That is, different types of ink can be ejected for each nozzle row. The case member 40 is also provided with an inlet 44 that communicates with the manifolds 100 and supplies ink to each manifold 100. The case member 40 is also provided with a connection port 43 that communicates with the through-hole 32 of the protective substrate 30 and through which the first flexible substrate 110 is inserted, and the first flexible substrate 110 is led out to the surface side facing the -Z direction of the liquid jet head H via the connection port 43. The case member 40 can be made of, for example, a metal material, a resin material, or the like.

[0035] A compliance substrate 45 is provided on the surface of the communication plate 15 on the +Z direction side where the first manifold portion 17 and the second manifold portion 18 open. This compliance substrate 45 seals the openings on the +Z direction side of the first manifold portion 17 and the second manifold portion 18. In this embodiment, such a compliance substrate 45 includes a sealing film 46 made of a flexible thin film and a fixed substrate 47 made of a hard material such as metal. An opening 48 that is completely removed in the thickness direction is provided in an area of ​​the fixed substrate 47 facing the manifold 100, and one side of the manifold 100 is a compliance portion 49 that is a flexible portion sealed only by the sealing film 46 that has flexibility. The surface of the fixed substrate 47 facing the +Z direction is fixed to the surface of the cover head 240 facing the -Z direction with an adhesive or the like, so that the head chip Hc is fixed to the cover head 240. The cover head 240 is a common member fixed to each of the fixed substrates 47 of a plurality of head chips Hc, two in this embodiment. Therefore, the two head chips Hc are integrated by the cover head 240. The surface of the cover head 240 facing the +Z direction constitutes a part of the ejection surface.

[0036] In such a head chip Hc, liquid is taken in from the inlet 44, and the inside of the flow path from the manifold 100 to the nozzles 21 is filled with ink. Then, in accordance with a signal from the drive signal selection circuit 111, a voltage is applied to each active portion 310 corresponding to the pressure chamber 12, thereby deflecting and deforming the vibration plate 50 together with the piezoelectric actuator 300. This increases the pressure of the liquid in the pressure chamber 12, and droplets are ejected from the specified nozzles 21.

[0037] The first flow path unit 200 and the second flow path unit 220 supply ink from the liquid storage portion 3 to the head chip Hc. As shown in FIGS. 2 to 4, the first flow path unit 200 includes a first flow path member 201, a second flow path member 202, and a third flow path member 203 stacked in this order in the +Z direction.

[0038] The first flow path member 201 has a first connection portion 204 that is connected to the liquid storage portion 3 in which the liquid is stored. In this embodiment, the first connection portion 204 is provided on a surface of the first flow path member 201 facing the -Z direction, protruding in a cylindrical shape in the -Z direction. The liquid storage portion 3 may be directly connected to this first connection portion 204, or may be connected via a supply pipe such as a tube. Inside the first connection portion 204, a first flow path 401 to which the liquid from the liquid storage portion 3 is supplied is provided. In addition, the first flow path 401 is extended along the lamination interface between the first flow path member 201 and the second flow path member 202. That is, the first flow path 401 has a portion formed along the Z-axis direction and a portion formed along a direction perpendicular to the Z-axis direction.

[0039] The second flow path member 202 has a second flow path 402 that communicates with the first flow path 401. The second flow path 402 is provided along the Z-axis direction. In addition, a first liquid reservoir 402a having an inner diameter wider than other regions is provided at the end of the second flow path 402 in the +Z direction.

[0040] The third flow path member 203 has a third flow path 403 that communicates with the second flow path 402. The third flow path 403 is provided along the Z-axis direction. A second liquid reservoir 403a having an inner diameter wider than other regions is provided at one end of the third flow path 403 in the -Z direction. A filter F is provided at the lamination interface between the second flow path member 202 and the third flow path member 203 so as to separate the first liquid reservoir 402a and the second liquid reservoir 403a. The filter F captures foreign matter such as dust and air bubbles contained in the ink.

[0041] The other end of the third flow path 403 is opened in a surface of the third flow path member 203 facing the +Z direction, and is connected in a liquid-tight state to a fifth flow path 405 of the second flow path unit 220 via a seal member 250. The seal member 250 is formed of an elastic member such as rubber, and is provided with a flow path communication passage 251 that penetrates in the Z-axis direction. The third flow path 403 and the fourth flow path 404 communicate with each other via the flow path communication passage 251.

[0042] The second flow path unit 220 is configured by stacking a fourth flow path member 221 and a fifth flow path member 222 in the +Z direction.

[0043] The fourth flow path member 221 has a cylindrical second connection portion 223 protruding toward the -Z direction on a surface facing the -Z direction. A fourth flow path 404 to which liquid from the third flow path 403 is supplied is provided inside the second connection portion 223. The fourth flow path 404 extends along the lamination interface between the fourth flow path member 221 and the fifth flow path member 222. That is, the fourth flow path 404 has a portion formed along the Z-axis direction and a portion formed along a direction perpendicular to the Z-axis direction. The end of the second connection portion 223 in the -Z direction is inserted through a first connection portion insertion hole 214 provided in the relay substrate 210, which will be described later in detail, and the fourth flow path 404 and the third flow path 403 of the third flow path member 203 are liquid-tightly connected through a flow path communication path 251 of the seal member 250 in the -Z direction of the relay substrate 210.

[0044] The fifth flow path member 222 has a cylindrical third connection part 224 that protrudes in the +Z direction on a surface facing the +Z direction. A fifth flow path 405 is provided inside the third connection part 224. The -Z direction end of the fifth flow path 405 communicates with the fourth flow path 404, and the +Z direction end passes through a second connection part insertion hole 235 of the holder 230, which will be described in detail later, and communicates with an inlet 44 of the head chip Hc in the storage space 233 of the holder 230. That is, the end face in the +Z direction of the second connection part 223 is fixed to a surface of the case member 40 of the head chip Hc facing the -Z direction. The second connection part 223 and the head chip Hc can be fixed by bonding via an adhesive, heat welding, ultrasonic welding, or the like. It is preferable that the second flow path unit 220 and the head chip Hc are bonded via an adhesive. By bonding the two together with an adhesive in this manner, the fifth flow path 405 and the inlet 44 of the head chip Hc are liquid-tightly connected, making it possible to prevent leakage of ink.

[0045] Further, the second flow passage unit 220 is provided with first wiring insertion holes 225 penetrating in the Z-axis direction. The first wiring insertion holes 225 are provided for inserting the first flexible substrates 110 of the head chip Hc and the drawn wiring portions of the heater 260, as will be described in detail later. For this reason, four first wiring insertion holes 225 are provided in this embodiment.

[0046] In this embodiment, the second flow path unit 220 is an example of a "flow path member", and the fourth flow path 404 and the fifth flow path 405 are examples of a "flow path". As shown in Fig. 3, the second flow path unit 220, which is an example of a "flow path member", has four "flow paths" consisting of the fourth flow path 404 and the fifth flow path 405 corresponding to the four nozzle rows, respectively. However, the second flow path unit 220, which is an example of a "flow path member", may be configured to have one "flow path" that distributes and supplies liquid to the four nozzle rows.

[0047] The relay substrate 210 is disposed between the seal member 250 and the second flow passage unit 220. The first flexible substrates 110 of the plurality of head chips Hc are commonly and electrically connected to the relay substrate 210. The heater 260 is also electrically connected to the relay substrate 210. The relay substrate 210 is made of a hard rigid substrate that is not flexible, and wiring, electronic components, and the like shown in the figure are mounted on the relay substrate 210. In this embodiment, as an example of an electronic component, a connector 211 to which an external wiring (not shown) provided outside the liquid ejecting head H is connected is illustrated. A print signal, etc. for controlling the head chip Hc is input from the external wiring to the relay substrate 210 via the connector 211, and is supplied from the relay substrate 210 to each head chip Hc. An external wiring opening 238 for inserting an external wiring connected to the connector 211 is provided on a side wall of the holder 230 that faces the connector 211, which will be described in detail later. The external wiring is connected to the connector 211 of the relay board 210 provided inside the holder 230 via the opening 238 for external wiring.

[0048] Furthermore, the relay substrate 210 has a first through hole 212 for leading out the first flexible substrate 110 of the head chip Hc to the surface side facing the -Z direction. A total of two first through holes 212 are provided, one for each head chip Hc.

[0049] The relay substrate 210 also has second through holes 213 for leading out lead wiring sections 280 of the heaters 260, which will be described in detail later, to the surface side facing the -Z direction. Two second through holes 213 are provided in total, one for each heater 260.

[0050] When viewed in the Z-axis direction, the opening areas of first through hole 212 and second through hole 213 are substantially the same. Here, "substantially the same opening area" means that the difference between the two opening areas is within 20%. The size of second through hole 213 is large enough to allow first flexible substrate 110 to be inserted therethrough.

[0051] The relay substrate 210 of this embodiment can have substantially the same shape as a relay substrate used in a liquid jet head that holds four head chips Hc in the accommodation space 233. That is, some of the four first through holes 212, which are formed in the relay substrate of the liquid jet head that holds the four head chips Hc and through which the four first flexible substrates 110 are respectively inserted, can be used as second through holes 213 through which the heater 260 is inserted.

[0052] In addition, the relay substrate 210 is provided with a first connection portion insertion hole 214 penetrating in the Z-axis direction. The second connection portion 223 of the second flow path unit 220 is inserted into the -Z direction side of the relay substrate 210 through the first connection portion insertion hole 214, and is connected to the third flow path 403 of the first flow path unit 200 through the flow path communication path 251 of the seal member 250. That is, a total of four first connection portion insertion holes 214 are provided, two for each head chip Hc.

[0053] The holder 230 has a first recess 231 that opens to a surface facing the +Z direction. The first recess 231 is defined by an outer peripheral wall portion 232. The cover head 240 is fixed to the end face of the holder 230 in the +Z direction, that is, the end face of the outer peripheral wall portion 232, and an accommodation space 233 is defined inside by the first recess 231 and the cover head 240. The accommodation space 233 has a first space 233a in which the head chip Hc is arranged and a second space 233b in which the head chip Hc is not arranged, and the first space 233a and the second space 233b are partitioned by a partition portion 234. In this embodiment, when viewed in the Z axis direction, the first space 233a is sandwiched between two second spaces 233b in a plan view. That is, when viewed in a plan view, the second spaces 233b are arranged on both sides of the first space 233a in the Y axis direction. In this embodiment, the first space 233a is disposed between two second spaces 233b in the Y-axis direction. That is, the partition wall 234 is disposed closer to the head chip Hc than the part 232a of the outer peripheral wall 232 in the Y-axis direction in which the part 232a of the outer peripheral wall 232, the second space 233b, and the plurality of head chips Hc are arranged. Incidentally, the part 232a of the outer peripheral wall 232 refers to the parts of the outer peripheral wall 232 on both sides in the Y-axis direction. By disposing the partition wall 234 closer to the head chip Hc than the part 232a of the outer peripheral wall 232 in this way, the heat conducted to the holder 230 by the heater 260, which will be described later in detail, can be efficiently conducted to the head chip Hc via the partition wall 234.

[0054] As shown in FIG. 3 and FIG. 4, the outer peripheral wall portion 232 has a plurality of ribs 232b protruding toward the partition wall portion 234. The ribs 232b protrude from the outer peripheral wall portion 232 toward the partition wall portion 234 along the Y-axis direction, and are continuously provided along the Z-axis direction of the accommodation space 233. The plurality of ribs 232b are arranged at predetermined intervals in the Y-axis direction. By providing the ribs 232b in this manner, the rigidity of the outer peripheral wall portion 232 can be improved, and deformation or breakage of the holder 230 can be suppressed. In this embodiment, the ribs 232b are provided on the outer peripheral wall portion 232, but the present invention is not limited thereto. The ribs 232b may be provided on the partition wall portion 234, or the ribs 232b may be provided on both the outer peripheral wall portion 232 and the partition wall portion 234.

[0055] The head chip Hc is accommodated in the first space 233a of the accommodation space 233. In this embodiment, two head chips Hc are accommodated in one first space 233a. A second connection part insertion hole 235 penetrating the holder 230 is provided on a surface located in the -Z direction of the inner surface of the first space 233a, i.e., on the bottom surface of the first recess 231. Since two head chips Hc are accommodated in the first space 233a, a total of four second connection part insertion holes 235 are provided, two for each head chip Hc. The third connection part 224 inserted through the second connection part insertion hole 235 is bonded to the head chip Hc in the first space 233a via an adhesive (not shown). An adhesive having high etching resistance to ink, such as an epoxy adhesive, is used as the adhesive for bonding the head chip Hc to the third connection part 224.

[0056] Also, each head chip Hc is adhered to the bottom surface of first recess 231 via an adhesive (not shown). The adhesive that adheres holder 230 and head chip Hc is, for example, an ultraviolet-curing adhesive, and temporarily fixes holder 230 and head chip Hc. That is, after temporarily fixing holder 230 and head chip Hc with an ultraviolet-curing adhesive to perform positioning, third connection portion 224 of second flow path unit 220 and head chip Hc are permanently fixed with an adhesive, thereby suppressing relative positional deviation between holder 230 and second flow path unit 220 and head chip Hc, and suppressing ink leakage at the connection portion of the flow path.

[0057] In this embodiment, head chip Hc and the bottom surface of first recess 231 of holder 230 are bonded to each other, but this is not particularly limited, and head chip Hc and holder 230 do not have to be directly bonded to each other.

[0058] The holder 230 also has a second wiring insertion hole 236, which is a through hole that communicates between the storage space 233 and the -Z direction of the holder 230. The first flexible substrate 110 of the head chip Hc stored in the storage space 233 is inserted through the second wiring insertion hole 236, and the first flexible substrate 110 is led out in the -Z direction of the holder 230. The second wiring insertion hole 236 is provided for each head chip Hc, that is, two in total, and the two second wiring insertion holes 236 communicate with the first space 233a, that is, are arranged at positions overlapping the first space 233a in which the head chip Hc is stored as viewed in the Z-axis direction. The holder 230 of this embodiment is formed by providing a partition wall portion 234 and a rib 232b to a holder that holds four head chips Hc in the storage space 233. For this reason, the second wiring insertion holes 236 are also provided at positions communicating with the second spaces 233b, that is, at positions overlapping with the second spaces 233b when viewed in the Z-axis direction. Of course, the second wiring insertion holes 236 communicating with the second spaces 233b may not be provided.

[0059] In addition, in this embodiment, the second wiring insertion hole 236 and the second connection portion insertion hole 235, which are connected to the first space 233a, are provided independently of each other, but this is not particularly limited, and the second wiring insertion hole 236 and the second connection portion insertion hole 235 may be provided partially continuous.

[0060] In such a liquid jet head H, ink from the liquid storage portion 3 is supplied to the head chip Hc via the first flow path unit 200 and the second flow path unit 220. In other words, the holder 230 does not define a flow path through which the ink flows.

[0061] The materials of the second flow path unit 220 and the holder 230 will be described later.

[0062] A cover head 240 is fixed to the surface of the holder 230 facing the +Z direction, that is, the end surface of the outer peripheral wall portion 232 facing the +Z direction and the end surface of the partition portion 234 facing the +Z direction. The cover head 240 is made of a metal plate such as stainless steel, and has a size that covers the opening of the first recess 231 of the holder 230. The cover head 240 defines an accommodation space 233 in the first recess 231 of the holder 230. The cover head 240 is a common member fixed to the surfaces facing the +Z direction of the two head chips Hc. In addition, the cover head 240 is provided with an exposure opening 241 that exposes the nozzle 21 of the head chip Hc in the +Z direction. The exposure opening 241 is provided independently for each head chip Hc. Ink is ejected in the form of droplets from the nozzle 21 exposed from the exposure opening 241 in the +Z direction.

[0063] As described above, in this embodiment, the bottom surface of first recess 231 of holder 230 is fixed to head chip Hc, but the bottom surface of first recess 231 of holder 230 does not have to be fixed to head chip Hc. Even if the bottom surface of first recess 231 of holder 230 is not fixed to head chip Hc, holder 230 holds head chip Hc via cover head 240. In other words, "holder 230 holds head chip Hc" includes holder 230 directly fixed to head chip Hc and holds it, and holder 230 indirectly holds head chip Hc via cover head 240 or second flow path unit 220 even if holder 230 is not directly fixed to head chip Hc.

[0064] In this embodiment, the cover head 240 is an example of a "fixed plate". Note that a reinforcing plate that is thicker than the cover head 240 may be provided between the cover head 240 and the holder 230. In this case, the cover head 240 and the reinforcing plate are an example of a "fixed plate".

[0065] Holder 230 has a second recess 237 that opens toward the -Z direction on the surface facing the -Z direction. Second recess 237 has approximately the same size as first recess 231 when viewed in the Z axis direction, and is disposed at a position that approximately overlaps with first recess 231. A heater 260 that heats ink in head chip Hc via holder 230 is provided on the bottom surface of second recess 237 facing the -Z direction.

[0066] The heater 260 in this embodiment is made of a film heater. The heater 260 is disposed at a position overlapping the second space 233b in the bottom surface of the second recess 237 of the holder 230 as viewed in the Z-axis direction. In this embodiment, a total of two heaters 260 are provided at positions overlapping the two second spaces 233b. As described above, in this embodiment, the first space 233a is disposed at a position sandwiched between the two second spaces 233b as viewed in the Z-axis direction. Therefore, by disposing the heater 260 at a position overlapping the second space 233b, the first space 233a is disposed at a position sandwiched between the two heaters 260. That is, the head chip Hc accommodated in the first space 233a is disposed at a position sandwiched between the two heaters 260. Therefore, the head chip Hc can be efficiently heated by the two heaters 260.

[0067] The two heaters 260 are arranged symmetrically about an axis along the X-axis direction when viewed in the Z-axis direction. This eliminates the need to create two different types of heaters 260, and allows the use of one type of heater 260 to reduce costs.

[0068] Fig. 6 is a cross-sectional view of the heater 260. Fig. 7 is a plan view of the heater 260 before the main surface portion 270 and the lead-out wiring portion 280 are folded. Fig. 8 is a plan view of a modified example of the heater before the main surface portion 270 and the lead-out wiring portion 280 are folded. Fig. 9 is a schematic diagram showing the wiring between the heater 260 and the relay substrate 210. Fig. 10 is a schematic diagram showing a modified example of the wiring between the heater 260 and the relay substrate 210.

[0069] As shown in FIGS. 6 and 7, the heater 260 includes a main surface portion 270 and an extraction wiring portion 280. The main surface portion 270 and the extraction wiring portion 280 are made of a material such as aluminum.

[0070] The main surface portion 270 includes a first base material 271 , a resistance wire 272 , a temperature detection element 273 , and a relay wire 274 .

[0071] The first base material 271 is made of an insulating sheet such as polyimide. The first base material 271 has a first surface 271a and a second surface 271b opposite to the first surface 271a. The thickness of the first base material 271 is, for example, 25 μm.

[0072] The first base material 271 has a communication hole 275 that communicates with the second wiring insertion hole 236 of the holder 230, and is provided in an annular shape when viewed in the Z-axis direction.

[0073] Resistance wire 272 has an electrical resistivity of 1.00 x 10 at 20°C. -6 It is preferable that the resistance wire 272 is made of a metal having a resistance of Ω·m. The resistance wire 272 is, for example, a nichrome wire made of a nickel-chromium alloy, or a Kanthal wire made of an iron-chromium-aluminum alloy. The resistance wire 272 may be made of stainless steel (SUS) having a slightly lower electrical resistivity than the heating wire, or copper (Cu) having a lower electrical resistivity than the heating wire. Such a resistance wire 272 is provided on the first surface 271a of the first base material 271. As shown in FIG. 7, the resistance wire 272 is provided in a meandering manner along the circumferential direction of the first base material 271 which is annular when viewed in the Z-axis direction. Also, the resistance wire 272 may be provided by folding back linearly along the circumferential direction as shown in FIG. 8. That is, in both the cases of FIG. 7 and FIG. 8, the resistance wire 272 is formed in an annular shape along the circumferential direction of the communication hole 275.

[0074] The cross-sectional area of ​​such resistance wire 272, which is defined by its width and thickness, is determined so that the resistance wire 272 has an electrical resistivity that provides an optimal amount of heat to the holder 230. For example, when the resistance wire 272 is made of copper (Cu), the resistance wire 272 may be formed long and thin because the resistance wire 272 has a lower electrical resistivity than a heating wire. The thickness of such resistance wire 272 is, for example, 12 μm.

[0075] The temperature detection element 273 is, for example, a thermistor or a resistance temperature detector, and is provided on the second surface 271b side of the first base material 271. The temperature detection element 273 is arranged at a position where it does not overlap with the resistance wire 272 when viewed in the Z-axis direction, which is the thickness direction of the first base material 271. In this embodiment, the temperature detection element 273 is provided at an end of the first base material 271, and the resistance wire 272 is not provided at the end of the first base material 271. As a result, the temperature detection element 273 and the resistance wire 272 do not overlap with each other in the Z-axis direction. By arranging the temperature detection element 273 at a position where it does not overlap with the resistance wire 272 when viewed in the Z-axis direction, when the temperature of the resistance wire 272 rises instantaneously, the temperature detection element 273 is not detected by the temperature detection element 273, and the temperature detection element 273 detects the temperature of the holder 230, which is the heat transfer target, so that the temperature detection element 273 can measure the temperature of the holder 230 more accurately.

[0076] Moreover, the temperature detection element 273 is disposed outside the resistance wire 272 provided in an annular shape, that is, on the opposite side to the communication hole 275 of the resistance wire 272. In this way, by disposing the temperature detection element 273 outside the resistance wire 272 in order to accurately detect the temperature of the head chip Hc with the temperature detection element 273, even if the temperature detection element 273 is disposed near the head chip Hc of the holder 230, the resistance wire 272 and the relay wiring 274 are disposed so as to overlap when viewed in the Z-axis direction, so that the main surface portion 270 does not become large.

[0077] The relay wiring 274 is provided on the second surface 271b of the first base material 271 and is electrically connected to the temperature detection element 273. The relay wiring 274 and the resistance wire 272 overlap when viewed in the Z-axis direction. Here, "the relay wiring 274 and the resistance wire 272 overlap when viewed in the Z-axis direction" means that they at least partially overlap each other. By providing the relay wiring 274 and the resistance wire 272 on different surfaces of the first base material 271 in this way, the main surface portion 270 of the heater 260 can be made smaller than when they are provided on the same surface. By arranging the relay wiring 274 and the resistance wire 272 at positions where they overlap when viewed in the Z-axis direction, the main surface portion 270 of the heater 260 can be made even smaller. In addition, as shown in FIG. 7, it is preferable that the relay wiring 274 and the resistance wire 272 extend in different directions when viewed in the Z-axis direction. By crossing the relay wiring 274 and the resistance wire 272 in different extending directions, the relay wiring 274 is prevented from being affected by noise generated by ON / OFF control of the resistance wire 272, power control using a semiconductor, so-called PWM control, and the like, and the measurement accuracy of the temperature detection element 273 can be improved. Also, as shown in FIG. 8, the relay wiring 274 and the resistance wire 272 may extend in the same direction when viewed in the Z-axis direction. By making the relay wiring 274 and the resistance wire 272 extend in the same direction in this way, the resistance wire 272 can be extended in a planar direction, so that heat is easily transferred in the planar direction via the resistance wire 272. In other words, the heat generated by the resistance wire 272 can be transferred in a planar direction via the first base material 271 and the resistance wire 272 itself, so that the holder 230 can be heated in a wide area with relatively little temperature deviation. The thickness of such relay wiring 274 is, for example, 12 μm.

[0078] The drawn-out wiring section 280 is connected to the main surface section 270 at a connection section 261. The drawn-out wiring section 280 is bent at approximately 90 degrees from the main surface section 270. The drawn-out wiring section 280 also has an insulating second base material 281 continuous with the first base material 271. That is, the first base material 271 and the second base material 281 are formed by bending the continuous base material at approximately 90 degrees. Here, the second base material 281 has a third surface 281a continuous with the first surface 271a of the first base material 271, and a fourth surface 281b continuous with the second surface 271b of the first base material 271.

[0079] The lead-out wiring section 280 includes a first lead-out wiring 282 and a second lead-out wiring 283 .

[0080] The first outgoing wiring 282 is electrically connected to the resistance wire 272. The first outgoing wiring 282 is provided on the third surface 281a of the second base material 281. The first outgoing wiring 282 extends in a direction intersecting with the first base material 271. Here, the "direction intersecting with the first base material 271" refers to a direction intersecting with the surface direction of the first base material 271, and includes a direction perpendicular to the first base material 271 and a direction inclined with respect to the perpendicular direction.

[0081] The second extension wiring 283 is electrically connected to the relay wiring 274. The second extension wiring 283, like the first extension wiring 282, extends in a direction intersecting with the first base material 271.

[0082] The second extraction wiring 283 includes a first portion 283a provided on the third surface 281a, and a second portion 283b provided on the fourth surface 281b and electrically connected to the first portion 283a via a through hole 281c penetrating the second base material 281. That is, the first portion 283a provided on the third surface 281a and the second portion 283b provided on the fourth surface 281b are electrically connected via the through hole 281c penetrating the second base material 281. In a configuration in which the second outgoing wiring 283 and the resistance wire 272 are outgoing to the same fourth surface 281b, by outgoing a portion of the second outgoing wiring 283 to the fourth surface 281b via a through hole 281c provided in the second substrate 281, there is no need to outgo the resistance wire 272 to the fourth surface 281b via a through hole, and the resistance wire 272 can be efficiently heated by passing a relatively large current through the resistance wire 272.

[0083] The first outgoing wiring 282, the second outgoing wiring 283, and the relay wiring 274 are preferably made of a material having as low an electrical resistivity as possible. For example, one or a combination of two or more selected from silver (Ag), copper (Cu), gold (Au), aluminum (Al), platinum (Pt), and tin (Sn) may be used as such a material. Furthermore, the first outgoing wiring 282, the second outgoing wiring 283, and the relay wiring 274 do not have a meandering portion, as compared with the resistance wire 272. Furthermore, although a circuit element or the like cannot be provided in the middle of the resistance wire 272, a circuit element or the like can be provided in the middle of the first outgoing wiring 282, the second outgoing wiring 283, and the relay wiring 274. Furthermore, the cross-sectional areas of the first outgoing wiring 282, the second outgoing wiring 283, and the relay wiring 274 are smaller than that of the resistance wire 272.

[0084] At the end of the lead wiring section 280 opposite to the connection section 261, a connection terminal section 284 is provided, which is a section where the first lead wiring 282 and the second lead wiring 283 are not covered by the cover layer 262 described later and are exposed to the outside. The connection terminal section 284 is inserted through the second through hole 213 of the relay substrate 210, led out to the -Z direction side of the relay substrate 210, and electrically connected to the surface of the relay substrate 210 facing the -Z direction. The connection between the relay substrate 210 and the lead wiring section 280 is made by brazing such as soldering or brazing, welding, adhesion via a conductive adhesive, or the like.

[0085] 9, the two heaters 260 may be wired independently on the relay substrate 210. Furthermore, the temperature detection elements 273 of the two heaters 260 are used, respectively. That is, the relay wiring 274 of the temperature detection elements 273 of the two heaters 260 are wired to the connector 211, respectively. By wiring the two heaters 260 independently on the relay substrate 210 in this way, it is possible to control the two heaters 260 independently, and it is possible to suppress bias in the temperature distribution of the holder 230 and perform highly accurate temperature control.

[0086] 10, the two heaters 260 may be wired in series on the relay board 210. The resistance wire 272 of one heater 260 and the resistance wire 272 of the other heater 260 may be connected in series on the relay board 210. In this case, the temperature detection element 273 of one heater 260 may be used, and the temperature detection element 273 of the other heater 260 may not be used. In other words, the relay wiring 274 of the temperature detection element 273 of one heater 260 may be wired to the connector 211, and the relay wiring 274 of the temperature detection element 273 of the other heater 260 may not be wired to the connector 211. By connecting the two heaters 260 in series on the relay board 210 in this way, it is not necessary to control the two heaters 260 individually, and the heaters 260 can be easily controlled.

[0087] In addition, the resistance wire 272 is disposed between the connection portion 261 between the main surface portion 270 and the drawn-out wiring portion 280 and the temperature detection element 273, as viewed in the Z-axis direction. Even in such a configuration in which the resistance wire 272 is disposed between the connection portion 261 and the temperature detection element 273, the resistance wire 272 and the relay wiring 274 can be routed so as not to increase the size of the main surface portion 270 due to the resistance wire 272 and the relay wiring 274 overlapping each other as viewed in the Z-axis direction.

[0088] Moreover, the temperature detection element 273 is disposed at a position closer to the nozzle 21 than the connection portion 261. By providing the temperature detection element 273 at a position closer to the nozzle 21 in this manner, the temperature on the nozzle 21 side can be detected by the temperature detection element 273 with relatively high accuracy. Furthermore, by disposing the connection portion 261 at a position farther from the nozzle 21, the heater 260 tends to become relatively large, but by routing the resistance wire 272 and the relay wiring 274 on different surfaces, a space for routing the resistance wire 272 and the relay wiring 274 on the same surface is not required, and thus the heater 260 can be prevented from becoming large.

[0089] A cover layer 262 is provided on each of the surfaces of the main surface portion 270 and the lead-out wiring portion 280 facing the first surface 271a, the third surface 281a, the second surface 271b, and the fourth surface 281b. The cover layer 262 is made of an insulating sheet such as polyimide. The thickness of the cover layer 262 is, for example, 30 μm.

[0090] The main surface portion 270 of the heater 260 is fixed to the holder 230, which is the object to be heated, on a surface facing the same direction as the direction in which the first surface 271a faces. By fixing the surface of the main surface portion 270 on which the resistance wire 272 is provided, facing the first surface 271a, to the holder 230 in this manner, the heat of the resistance wire 272 can be efficiently conducted to the holder 230. Of course, the surface of the main surface portion 270 facing the second surface 271b may be fixed to the holder 230, but the heat of the resistance wire 272 will be conducted to the holder 230 via the first base material 271, and the efficiency of heat conduction will decrease. The method of fixing the heater 260 to the holder 230 is not particularly limited, and examples include adhesion via an adhesive, double-sided tape, and the like. In this embodiment, the heater 260 is fixed to the holder 230 by double-sided tape 263. The thickness of the double-sided tape 263 is, for example, 50 μm.

[0091] As shown in FIG. 4, the heater 260 is disposed at a position where the area S1 of the portion of the heater 260 that overlaps with the accommodation space 233 but does not overlap with the head chip Hc is larger than the area S2 of the region of the heater 260 that overlaps with the head chip Hc when viewed in the Z-axis direction. The area S2 is the region of the heater 260 indicated by the dashed line in FIG. 4, and is the region of the heater 260 that overlaps with the accommodation space 233 other than the area S2. In this way, the heater 260 is disposed at a position where the area S1 is larger than the area S2. In other words, when there is a dummy second space 233b in the accommodation space 233 where the head chip Hc is not disposed, the heater 260 can be disposed by utilizing the second space 233b, thereby making it easier to install the heater 260. The heater 260 may be disposed at a position where it does not overlap with the head chip Hc at all when viewed in the Z-axis direction.

[0092] The heater 260 heats the ink in the head chip Hc via the holder 230. Here, the heat of the heater 260 is conducted to the cover head 240 via the outer peripheral wall portion 232 and the partition portion 234 of the holder 230. The heat conducted to the cover head 240 is conducted to the communication plate 15 via the compliance substrate 45, and the heat conducted to the communication plate 15 is conducted to the nozzle plate 20, the flow path forming substrate 10, the case member 40, etc. Note that since the cover head 240 is formed of a metal with high thermal conductivity, the heat of the holder 230 is easily conducted to the head chip Hc via the cover head 240.

[0093] Furthermore, in this embodiment, since case member 40 of head chip Hc is directly fixed to holder 230, heat is directly transferred from holder 230 to case member 40 of head chip Hc. Furthermore, head chip Hc is accommodated in accommodation space 233 of holder 230, and the outer periphery other than in the +Z direction is covered by holder 230. Therefore, heat of holder 230 heated by heater 260 is transferred to the entire head chip Hc via the atmosphere in accommodation space 233. In this way, heater 260 heats head chip Hc via holder 230, and the ink in head chip Hc is heated.

[0094] The heating of the holder 230 by the heater 260 is controlled by the control unit 4 based on the temperature detected by the temperature detection element 273. In this embodiment, as described above, the temperature detection element 273 is disposed at a position that does not overlap with the resistance wire 272 when viewed in the Z-axis direction, so that the temperature detection element 273 can detect the temperature of the holder 230, which is the target of heat transfer, without being detected by the temperature detection element 273 when the resistance wire 272 momentarily rises in temperature. Therefore, the temperature detection element 273 can measure the temperature of the holder 230 more accurately, and the holder 230 can be heated to a target temperature by the heater 260 with high accuracy.

[0095] In this embodiment, the lead-out wiring portion is an example of a "second flexible substrate."

[0096] Here, when attempting to eject a liquid having a high viscosity in a low-temperature environment, such as ultraviolet-curable ink, from the liquid ejection head H, it is difficult to eject the liquid from the nozzle 21 in a state where the viscosity of the liquid is high. Therefore, it is necessary to reduce the viscosity by heating the liquid in the liquid ejection head H with the heater 260 described above. Therefore, it is desirable to form the holder 230, which is the object to be heated by the heater 260, from a material such as metal or ceramics having a high thermal conductivity. However, since it is very expensive to construct the holder 230, which has a complex shape, from a material such as metal or ceramics, it is desirable to construct it inexpensively from a resin material. However, since the thermal conductivity of the holder 230 made of resin is low, there is a problem that the liquid in the liquid ejection head H cannot be sufficiently heated by the heater 260.

[0097] Therefore, the holder 230 of this embodiment is made of a thermally conductive resin. The thermally conductive resin refers to a resin that is made thermally conductive by including a thermally conductive filler in a resin matrix. By making the holder 230 of a thermally conductive resin, it is possible to facilitate manufacturing and reduce costs compared to when the holder 230 is made of metal or ceramics, and it is also possible to efficiently heat the ink in the head chip Hc through the holder 230 by the heater 260. In addition, since the holder 230 does not define a flow path, even if the holder 230 is made of a thermally conductive resin, it is possible to suppress the thermally conductive filler from falling off the resin material and being mixed into the ink in the flow path. Therefore, it is possible to reduce the risk of the nozzle 21 being clogged by the fallen thermally conductive filler, which causes ejection failure.

[0098] In addition, as the resin matrix used for the thermally conductive resin, for example, any one of known thermoplastic resins can be appropriately selected and used. Examples of such thermoplastic resins include polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon 6, nylon 66, nylon 11, nylon 12, and aromatic polyamides, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polycyclohexylmethylene terephthalate, ABS resins, polycarbonate resins, modified polyphenylene ether resins, polyacetal resins, polyphenylene sulfide resins, wholly aromatic polyester resins, polyether ether ketone resins, polyether sulfone resins, polysulfone resins, polyamide imide resins, and copolymer resins consisting of two or more of the constituent components of these resins. Only one of these thermoplastic resins may be used alone, or two or more may be used in combination. In addition, as the resin matrix used for the thermally conductive resin, any one of known thermosetting resins can be appropriately selected and used. Examples of such thermosetting resins include phenolic resins, polyurethanes, epoxy resins, and melamine resins.

[0099] The thermally conductive filler contained in such a resin matrix is ​​not particularly limited as long as it has a high thermal conductivity, and various types of fillers can be used. Examples of such thermally conductive fillers include oxide powders such as aluminum oxide (also known as alumina), zinc oxide, magnesium oxide, and silicon dioxide, nitride powders such as boron nitride, aluminum nitride, and silicon nitride, metal powders such as gold, silver, aluminum, iron, and copper, and silicon carbide powder. The high thermally conductive filler may be used alone or in combination of two or more.

[0100] When the particle size of the high thermal conductive filler is small, the viscosity of the compound increases significantly during filling, making it difficult to fill, and as a result, it may not be possible to obtain a resin material with high thermal conductivity. Also, when the particle size is large, the distance between the thermal conductive fillers becomes narrower and they tend to come into contact with each other, so that heat is easily transmitted and the thermal conductivity tends to be relatively high. In particular, in this embodiment, since the holder 230 does not define a flow path, even if the particle size of the thermal conductive filler is large and the thermal conductive filler is easily peeled off from the resin material, the peeled off thermal conductive filler is unlikely to be mixed into the ink. For this reason, the average particle size of the thermal conductive filler used in the thermal conductive resin is preferably larger than 80 μm, more preferably 90 μm or more, and even more preferably 100 μm or more. By forming the holder 230 from a thermally conductive resin containing thermally conductive filler with an average particle size larger than the diameter of the nozzle 21, the thermal conductivity of the holder is made relatively high and the thermally conductive filler does not mix with the ink, thereby suppressing the occurrence of problems such as clogging of the nozzle 21.

[0101] In addition, the average particle size of the thermally conductive filler is obtained by measuring the longest length of each thermally conductive filler and calculating the average when the thermally conductive filler is not spherical. The thermally conductive filler is measured by directly imaging the thermally conductive filler or by imaging the cross section of the thermally conductive filler contained in the thermally conductive resin.

[0102] Moreover, the content of the thermally conductive filler is preferably greater than 70% by volume with respect to the total volume of the holder 230. By forming the holder 230 with the content of the thermally conductive filler greater than 70% by volume in this manner, the thermal conductivity of the holder 230 can be made relatively high. Of course, the content of the thermally conductive filler may be 70% by volume or less with respect to the total volume of the holder 230. This can improve moldability. However, if the content of the thermally conductive filler is low, the thermal conductivity of the holder 230 decreases. For this reason, the content of the thermally conductive filler is preferably 30% by volume or more with respect to the total volume of the holder 230, and more preferably 50% by volume or more.

[0103] In addition, additives such as other fillers, flame retardants, heat resistance improvers, and weather resistance improvers can be blended into the thermally conductive resin material as necessary. Examples of the other fillers include fillers with a large reinforcing effect, such as mica, talc, or fibers such as carbon fiber and glass fiber, and whiskers. Specific examples of whiskers include non-oxide whiskers made of silicon carbide, silicon nitride, etc., metal oxide whiskers made of ZnO, MgO, TiO2, SnO2, Al2O3, etc., and double oxide whiskers made of potassium titanate, aluminum borate, basic magnesium sulfate, etc., and among these, double oxide whiskers are preferred because they can be easily combined with plastics.

[0104] Moreover, the first thermal conductivity of the holder 230 in the Z-axis direction, which is the thickness direction of the heater 260, is greater than the second thermal conductivity in the direction along the surface direction of the heater 260, i.e., the direction along the XY plane. Note that the first thermal conductivity is preferably three times or more the second thermal conductivity.

[0105] In other words, the first thermal conductivity is the thermal conductivity in the direction in which heater 260, a part of holder 230 sandwiched between heater 260 and head chip Hc, and head chip Hc are arranged. The second thermal conductivity is the thermal conductivity in the direction perpendicular to the above direction.

[0106] In other words, the first thermal conductivity is the thermal conductivity in the Z-axis direction, which is the direction perpendicular to the surface of the holder 230 facing the opposite side to the surface fixed to the cover head 240, i.e., the surface on which the heater 260 of the holder 230 is arranged. The second thermal conductivity is the thermal conductivity in the direction parallel to the surface on which the heater 260 of the holder 230 is arranged.

[0107] That is, the heat of the heater 260 easily moves along the Z-axis direction inside the holder 230, making it easier to heat the cover head 240. As a result, the ink inside the head chip Hc is easily heated by heat transfer from the cover head 240 to the head chip Hc.

[0108] The thermally conductive resin according to this embodiment is characterized in that at least one of the thermal conductivity in the Z-axis direction and the thermal conductivity in the direction along the XY plane is 1.0 W / m·K or more, preferably 2.0 W / m·K or more, more preferably 10 W / m·K or more, and even more preferably 20 W / m·K or more.

[0109] The thermal conductivity according to this embodiment can be measured according to a method conforming to JIS-A-1412, and a specific example of a measuring device is a thermal property measuring device TPA-501 (manufactured by Kyoto Electronics Manufacturing Co., Ltd.) using a hot disk method. Alternatively, the thermal conductivity may be measured using a flash method.

[0110] The thermally conductive resin is preferably a conductive resin material.

[0111] In contrast, the second flow passage unit 220 is formed of a resin that does not contain a thermally conductive filler. Here, in this embodiment, "not containing a thermally conductive filler" includes those that do not contain any thermally conductive filler and those that contain a thermally conductive filler if the thermal conductivity is less than 1.0 W / m·K. In other words, in this embodiment, if the thermal conductivity is less than 1.0 W / m·K, it is considered that the thermally conductive filler is not contained. By using a resin material that does not contain a thermally conductive filler as the second flow passage unit 220 that defines the flow passage in this way, it is possible to prevent the thermally conductive filler from peeling off from the second flow passage unit 220 and mixing into the ink, and it is possible to suppress the occurrence of variations in the ejection state of ink droplets and perform stable ejection.

[0112] Similarly to the second flow path unit 220, the first flow path unit 200 is made of a material that does not contain a thermally conductive filler.

[0113] In this manner, by forming the first flow path unit 200 and the second flow path unit 220 from a resin material that does not contain a thermally conductive filler, it is possible to prevent the thermally conductive filler from falling off into the flow paths.

[0114] (Other embodiments) Although one embodiment of the present invention has been described above, the basic configuration of the present invention is not limited to the above.

[0115] For example, in the above-described embodiment 1, the liquid jet head H has two head chips Hc, but this is not particularly limited, and the number of head chips Hc held by the liquid jet head H may be one, or three or more.

[0116] In the above-described first embodiment, two heaters 260 are provided, but the present invention is not limited to this, and one heater made of a continuous base material may be provided. For example, if there is space on both sides of the second wiring insertion hole 236 of the second recess 237 in the X-axis direction, the heaters may be continuous there. If there is no space on both sides of the second wiring insertion hole 236 of the second recess 237 in the X-axis direction, a part of the heater may be bent along the wall surface of the second recess 237 to be continuous.

[0117] In the above-mentioned first embodiment, the holder 230 has the second space 233b, but the present invention is not limited to this, and the second space 233b may be filled with resin. However, the thick part of a resin product is generally prone to the occurrence of so-called "sink marks", which are depressions on the surface caused by shrinkage when the resin cools and hardens during molding. Therefore, by providing the second space 233b in the holder 230, it is possible to manufacture a high-precision product by suppressing the occurrence of sink marks during molding.

[0118] In addition, in the above-mentioned embodiment 1, the heater 260 is a film heater, but this is not limited to this, and any heater that can be inserted into the space between the holder 230 and the second flow path unit 220, such as a ceramic heater, is also acceptable, and is not limited to this.

[0119] In the above-described first embodiment, the lead-out wiring section 280 is a part of the heater 260, but the present invention is not limited thereto, and the lead-out wiring section 280 may not be a part of the heater 260. In other words, in the above-described first embodiment, the first base material 271 of the main surface section 270 and the second base material 281 of the lead-out wiring section 280 are integrally formed by folding the same base material, but the present invention is not limited thereto, and the main surface section and the lead-out wiring section, which are separate bodies, may be electrically connected and integrated. In other words, the heater may be formed only by the main surface section, and the lead-out wiring section may not be a part of the heater. The electrical connection between the main surface section and the lead-out wiring section may be made by soldering, using a conductive adhesive (ACP), or the like, or via a connector.

[0120] (Additional Note) From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0121] The liquid ejection head of embodiment 1, which is a preferred embodiment, comprises one or more head chips that eject liquid in a ejection direction, a flow path member that defines a flow path through which liquid flows to supply liquid to the one or more head chips, a holder that holds the one or more head chips, and a heater that heats the holder, wherein the holder does not define a flow path through which liquid flows and is made of a thermally conductive resin that contains a thermally conductive filler. According to this, by forming the holder from resin, the cost can be reduced compared to forming the holder from metal or ceramics. Also, by forming the holder from thermally conductive resin, the heater can efficiently heat the head chip through the holder. Also, since the holder does not define a flow path, even if the thermally conductive filler contained in the thermally conductive resin forming the holder falls off, it will not be mixed into the liquid, and poor liquid ejection caused by the thermally conductive filler can be suppressed.

[0122] In Aspect 2, which is a specific example of Aspect 1, the average particle size of the thermally conductive filler is greater than 80 μm. By making the average particle size of the thermally conductive filler greater than 80 μm, the thermal conductivity of the holder is improved, and the head chip can be efficiently heated by the heater through the holder.

[0123] In aspect 3, which is a specific example of aspect 1, the content of the thermally conductive filler relative to the total volume of the holder is greater than 70%. By making the content of the thermally conductive filler greater than 70% relative to the total volume of the holder, the thermal conductivity of the holder is improved, and the head chip can be efficiently heated by the heater through the holder.

[0124] In aspect 4, which is a specific example of aspect 1, the one or more head chips are fixed to a metal fixing plate, the fixing plate is fixed to the holder, the heater is disposed on a surface of the holder facing away from the surface fixed to the fixing plate, and a first thermal conductivity in a direction perpendicular to the surface of the holder is greater than a second thermal conductivity in a direction parallel to the surface of the holder. In this way, the thermal conductivity of the holder is high in the direction from the heater to the fixing plate, and the head chips can be efficiently heated via the holder and the fixing plate.

[0125] In aspect 5, which is a specific example of aspect 1, a first thermal conductivity of the holder in a thickness direction of the heater is greater than a second thermal conductivity in a direction along a surface of the heater, which makes it easier to transfer heat from the heater within the holder.

[0126] In aspect 6, which is a specific example of aspect 1, a first thermal conductivity of the holder in a first direction in which the heater, a part of the holder, and the head chip are arranged is greater than a second thermal conductivity of the holder in a second direction perpendicular to the first direction, which makes it easier to transfer heat from the heater within the holder.

[0127] In aspect 7, which is a specific example of aspects 4 to 6, the first thermal conductivity is at least three times the second thermal conductivity.

[0128] In aspect 8, which is a specific example of aspect 1, the holder defines an accommodation space for accommodating the one or more head chips, and in a plan view seen in the ejection direction, the area of ​​a portion of the heater that overlaps with the accommodation space but does not overlap with the one or more head chips is larger than the area of ​​the portion of the heater that overlaps with the one or more head chips. This makes it easy to install the heater when there is a dummy space in the accommodation space where no head chip is placed, by using that empty space to place the heater.

[0129] In Aspect 9, which is a specific example of Aspect 8, the holder has a partition wall that divides the accommodation space into a first space in which the one or more head chips are arranged and a second space in which the one or more head chips are not arranged. This allows heat from the heater to be conducted to the head chip via the partition wall.

[0130] In aspect 10, which is a specific example of aspect 9, the holder has an outer peripheral wall portion for defining the storage space, and the partition portion is closer to the one or more head chips than the part of the outer peripheral wall portion in a direction in which the part of the outer peripheral wall portion, the second space, the partition portion, and the one or more head chips are arranged. This allows heat from the heater to be efficiently conducted to the head chips via the partition portion.

[0131] In aspect 11, which is a specific example of aspect 9, the first space is sandwiched between the second spaces in the plan view. With this, by arranging the heaters at positions that overlap the second spaces in the plan view, it is possible to arrange the head chip at a position sandwiched between the heaters. Therefore, the head chip can be efficiently heated by the heaters.

[0132] In aspect 12, which is a specific example of aspect 8, each of the one or more head chips has a first flexible substrate, the liquid ejection head includes an intermediate substrate electrically connected to the one or more first flexible substrates, the intermediate substrate has one or more first through holes through which the one or more first flexible substrates are inserted, and a second through hole through which a second flexible substrate electrically connected to the heater is inserted, and an opening area of ​​the first through hole and an opening area of ​​the second through hole are substantially the same in the plan view. This allows the second flexible substrate of the heater to be connected to the intermediate substrate via a second through hole that is not used for the head chip of the intermediate substrate.

[0133] In Aspect 13, which is a specific example of Aspect 1, the flow path member has a thermal conductivity of less than 1.0 W / m K. With this, the flow path member does not contain any thermally conductive filler or contains only a very small amount of the thermally conductive filler, so that the thermally conductive filler is unlikely to fall off the flow path member and the fallen thermally conductive filler can be prevented from mixing with the liquid.

[0134] A liquid jet device according to a fourteenth aspect, which is a preferred aspect, includes the liquid jet head according to the first aspect, and a liquid reservoir that stores liquid to be supplied to the liquid jet head.

[0135] This makes it possible to reduce costs, efficiently heat the liquid inside the head chip, and realize a liquid ejection device with improved liquid ejection stability. [Explanation of symbols]

[0136] H...liquid ejection head, Hc...head chip, S...medium, 1...liquid ejection device, 3...liquid storage section, 4...control unit, 5...transport mechanism, 6...movement mechanism, 7...holding body, 8...transport belt, 10...flow path forming substrate, 12...pressure chamber, 15...communication plate, 19...supply communication path, 20...nozzle plate, 21...nozzle, 30...protective substrate, 40...case member, 45...compliance substrate, 46...sealing film, 47...fixed substrate, 49...compliance section, 50...diaphragm, 51...elastic film, 52...insulating film, 60...first electrode, 70...piezoelectric layer, 80...second electrode, 91...individual lead electrode, 100...manifold, 110...first flexible substrate, 111...drive signal selection circuit, 200...first flow path unit, 201...first flow path member, 202...second flow path member, 203...third flow path member, 204...first connection portion, 210...relay substrate, 211...connector, 212...first through hole, 213...second through hole, 214...first connection portion insertion hole, 220...second flow path unit, 221...fourth flow path member, 222...fifth flow path member, 223...second connection portion, 224...third connection portion, 225...first wiring insertion hole, 230...holder, 231...first recess, 232...outer peripheral wall portion, 232a...part of outer peripheral wall portion, 232b...rib, 233...accommodation space, 233a...first space, 233b...second space, 234...partition wall portion, 235...second connection portion insertion hole, 236...second wiring insertion hole, 237...second recess, 238...external wiring opening, 240...cover head, 241...exposure opening, 250...sealing member, 251...flow path communication passage, 260...heater, 261...connection portion, 262...cover layer, 263...double-sided tape, 270...main surface portion, 271...first base material, 271a...first surface, 271b...second surface, 272...resistance wire, 273...temperature detection element, 274...relay wiring, 275...communication hole, 280...drawing wiring section, 281...second substrate, 281a...third surface, 281b...fourth surface, 281c...through hole, 282...first drawing wiring, 283...second drawing wiring, 283a...first portion, 283b...second portion, 300...piezoelectric actuator, 310...active section, 401...first flow path, 402...second flow path, 402a...first liquid reservoir, 403...third flow path, 403a...second liquid reservoir, 404...fourth flow path, 405...fifth flow path, F...filter

Claims

1. one or more head chips that eject liquid in an ejection direction; a flow path member defining a flow path through which a liquid flows for supplying the liquid to the one or more head chips; A holder for holding the one or more head chips; A heater for heating the holder; Equipped with The holder does not define a flow path through which a liquid flows, and is made of a thermally conductive resin containing a thermally conductive filler. A liquid jet head comprising:

2. The average particle size of the thermally conductive filler is greater than 80 μm; The liquid jet head according to claim 1 .

3. The content of the thermally conductive filler relative to the total volume of the holder is greater than 70%; The liquid jet head according to claim 1 .

4. The one or more head chips are fixed to a metal fixing plate, The fixing plate is fixed to the holder, the heater is disposed on a surface of the holder facing away from a surface fixed to the fixing plate, a first thermal conductivity in a direction perpendicular to the surface of the holder is greater than a second thermal conductivity in a direction parallel to the surface of the holder; The liquid jet head according to claim 1 .

5. a first thermal conductivity of the holder in a thickness direction of the heater is greater than a second thermal conductivity in a direction along a surface of the heater; The liquid jet head according to claim 1 .

6. a first thermal conductivity of the holder in a first direction in which the heater, a part of the holder, and the head chip are arranged is greater than a second thermal conductivity of the holder in a second direction perpendicular to the first direction; The liquid jet head according to claim 1 .

7. The first thermal conductivity is three times or more than the second thermal conductivity.

7. The liquid jet head according to claim 4, wherein the liquid jet head is a liquid jet head.

8. the holder defines an accommodation space for accommodating the one or more head chips; In a plan view seen in the ejection direction, an area of ​​a region of the heater that overlaps with the accommodation space but does not overlap with the one or more head chips is larger than an area of ​​a region of the heater that overlaps with the one or more head chips. The liquid jet head according to claim 1 .

9. the holder has a partition wall that divides the accommodation space into a first space in which the one or more head chips are arranged and a second space in which the one or more head chips are not arranged; The liquid jet head according to claim 8 .

10. The holder has an outer peripheral wall portion for defining the accommodation space, the partition wall is closer to the one or more head chips than the part of the outer peripheral wall portion in a direction in which the part of the outer peripheral wall portion, the second space, the partition wall portion, and the one or more head chips are arranged. The liquid jet head according to claim 9 .

11. The first space is sandwiched between the second space in the plan view. The liquid jet head according to claim 9 .

12. Each of the one or more head chips has a first flexible substrate; the liquid jet head includes an intermediate substrate electrically connected to the one or more first flexible substrates, the relay substrate has one or more first through holes through which the one or more first flexible substrates are inserted, and a second through hole through which a second flexible substrate electrically connected to the heater is inserted, In the plan view, an opening area of ​​the first through hole and an opening area of ​​the second through hole are substantially the same. The liquid jet head according to claim 8 .

13. The flow path member has a thermal conductivity of less than 1.0 W / m K. The liquid jet head according to claim 1 .

14. The liquid jet head according to claim 1 , a liquid storage section configured to store a liquid to be supplied to the liquid jet head; Equipped with A liquid ejection apparatus comprising:

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