Liquid ejecting head and liquid ejecting apparatus

Abstract

The invention provides a liquid ejecting head and a liquid ejecting apparatus which can realize miniaturization of a heater and can heat liquid through the heater. The liquid ejecting head includes: a nozzle that ejects a liquid; and a planar heater (260) for heating the liquid supplied to the nozzle, the heater having a main surface portion (270) including a temperature detection element (273), an insulating first base material (271) including a first surface (271a) and a second surface (271b) on the opposite side of the first surface, a resistance wire (272), and relay wiring (274), the resistance wire (272) being electrically connected to the first surface (271a), and the relay wiring (274) being electrically connected to the first surface (271a). The resistance wire is disposed on the first surface and heats an object to be heated, which is a part of the liquid ejecting head, and the relay wiring is electrically connected to the temperature detection element and is disposed on the second surface. The resistance wire and the relay wiring overlap when viewed in the thickness direction of the main surface portion.

Description

Technical Field

[0001] The present invention relates to a liquid ejecting head for ejecting liquid from a nozzle and a liquid ejecting device. Background Art

[0002] Conventionally, there has been known a liquid ejecting apparatus including a liquid ejecting head for ejecting liquid such as ink, typified by an inkjet printer.

[0003] A liquid ejecting head having a planar heater for heating ejected liquid is known (see, for example, Patent Document 1). In the planar heater, a resistance wire as a heating wire and a relay wire connected to a temperature sensor for detecting temperature are arranged on the same plane.

[0004] However, when the resistance wire and the relay wiring are provided on the same surface of the heater, a space is required to arrange the relay wiring so as to avoid the resistance wire, which may increase the size of the heater.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 11-10862 Summary of the invention

[0006] The method of the present invention for solving the above-mentioned problems is a liquid injection head, characterized in that it comprises: a nozzle that ejects liquid; a planar heater that is used to heat the liquid supplied to the nozzle, the heater having a main surface, the main surface including a temperature detection element, an insulating first substrate, a resistance wire and a relay wiring, the first substrate including a first surface and a second surface opposite to the first surface, the resistance wire is arranged on the first surface and heats a heating object that is a part of the liquid injection head, the relay wiring is electrically connected to the temperature detection element and is arranged on the second surface, and the resistance wire and the relay wiring overlap when viewed along the thickness direction of the main surface.

[0007] Still another aspect of the present invention is a liquid ejecting device comprising: the liquid ejecting head according to the above aspect; and a liquid storage portion that stores the liquid supplied to the liquid ejecting head. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a diagram showing a schematic configuration of a liquid ejecting device according to Embodiment 1.

[0009] Figure 2 It is an exploded perspective view of the liquid ejecting head according to the first embodiment.

[0010] Figure 3 It is a cross-sectional view of the liquid ejecting head according to Embodiment 1.

[0011] Figure 4 It is a plan view of the retainer involved in Embodiment 1.

[0012] Figure 5 It is a cross-sectional view of the head chip according to the first embodiment.

[0013] Figure 6 It is a cross-sectional view of the heater according to the first embodiment.

[0014] Figure 7 This is a plan view of the heater according to the first embodiment.

[0015] Figure 8 This is a plan view of a modified example of the heater according to the first embodiment.

[0016] Fig. 9 This is a diagram schematically showing the configuration of a heater and a relay substrate according to the first embodiment.

[0017] Fig.10 This is a schematic structural diagram showing a modified example of the heater and relay substrate according to the first embodiment. DETAILED DESCRIPTION

[0018] Hereinafter, the present invention will be described in detail based on the embodiment. However, the following description represents one mode of the present invention and can be arbitrarily changed within the scope of the present invention. The components marked with the same symbols in each figure represent the same components, and the description is appropriately omitted. In addition, in each figure, X, Y, and Z represent three spatial axes that are orthogonal to each other. In this specification, the directions along these axes are set as the X direction, the Y direction, and the Z direction. The direction pointed by the arrow mark in each figure is set as the positive (+) direction, and the opposite direction of the arrow mark is set as the negative (-) direction for description. In addition, the directions of the three spatial axes that are not limited to the positive direction and the negative direction are set as the X-axis direction, the Y-axis direction, and the Z-axis direction for description. In addition, the situation of observing along the Z-axis direction is referred to as "plane observation".

[0019] Implementation Method 1

[0020] Figure 1 It is a diagram showing a schematic configuration of a liquid ejecting device 1 according to Embodiment 1 of the present invention.

[0021] like Figure 1 As shown, the liquid ejection device 1 is a so-called serial printer that includes a liquid ejection head H, and ejects liquid in the +Z direction from the liquid ejection head H toward the medium S while conveying the medium S in the X-axis direction and reciprocating the liquid ejection head H in the Y-axis direction, thereby performing printing. In addition, as the medium S, in addition to cloth, any material such as recording paper or resin film can be used.

[0022] Such a liquid ejecting apparatus 1 includes a liquid ejecting head H, a liquid storage unit 3 , a control unit 4 as a control unit, a transport mechanism 5 for delivering a medium S, and a moving mechanism 6 .

[0023] The liquid ejecting head H ejects the liquid supplied from the liquid storage portion 3 storing the liquid in the form of liquid droplets in the +Z direction.

[0024] The liquid storage unit 3 stores a plurality of types of liquids having different colors or components ejected from the liquid ejecting head H separately. Examples of the liquid storage unit 3 include a cartridge that can be attached to and detached from the liquid ejecting device 1, a bag-shaped ink bag formed of a flexible film, and an ink tank that can replenish ink. Figure 1 , one liquid storage unit 3 is illustrated. Incidentally, the liquid storage unit 3 may be a liquid storage unit 3 having divided small chambers for storing a plurality of types of liquids individually, or may be a plurality of liquid storage units 3 individually provided according to a plurality of types of liquids. In addition, the liquid storage unit 3 may also be divided into a main tank and a sub-tank. The main tank may be connected to the liquid ejecting head H, and the liquid consumed by ejecting liquid droplets from the liquid ejecting head H is replenished from the main tank to the sub-tank.

[0025] The control unit 4 centrally controls the various elements of the liquid ejecting apparatus 1 , namely, the liquid ejecting head H, the transport mechanism 5 , the moving mechanism 6 , and the like.

[0026] The conveying mechanism 5 is a mechanism for conveying the medium S in the X-axis direction, and has a conveying roller 5a. The conveying mechanism 5 conveys the medium S in the X-axis direction by rotating the conveying roller 5a. The conveying roller 5a is rotated by the driving of a conveying motor (not shown). The control unit 4 controls the conveying of the medium S by controlling the driving of the medium conveying motor. In addition, the conveying mechanism 5 for conveying the medium S is not limited to a mechanism having a conveying roller 5a, and may be a mechanism for conveying the medium S by a belt or a roller, for example.

[0027] The moving mechanism 6 is a mechanism for reciprocating the liquid ejecting head H in the Y-axis direction, and includes a holding body 7 and a conveyor belt 8. The holding body 7 is a so-called slide that holds the liquid ejecting head H, and is fixed on the conveyor belt 8. The conveyor belt 8 is an endless belt that is set along the Y-axis direction. The conveyor belt 8 is rotated by the drive of a conveying motor (not shown). The control unit 4 rotates the conveyor belt 8 by controlling the drive of the conveying motor, thereby reciprocating the liquid ejecting head H together with the holding body 7 in the Y-axis direction. In addition, the holding body 7 can also be a structure that carries the liquid ejecting head H and the liquid storage unit 3 together.

[0028] The liquid ejecting head H executes the ejection of liquid supplied from the liquid storage section 3 in the form of liquid droplets from the plurality of nozzles 21 (see FIG. 1 ). Figure 5 ) respectively eject in the +Z direction. By performing the ejection operation performed by the liquid ejecting head H in parallel with the conveyance of the medium S performed by the conveying mechanism 5 and the reciprocating movement of the liquid ejecting head H performed by the moving mechanism 6, so as to implement so-called printing of applying liquid on the medium S.

[0029] Figure 2 It is a perspective exploded view of the liquid ejecting head H. Figure 3 2 is a cross-sectional view of the liquid ejecting head H. Figure 4 It is a plan view of the holder 230 viewed from the -Z direction. In addition, each direction of the liquid ejecting head H will be described based on the directions when mounted on the liquid ejecting apparatus 1, that is, the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0030] As shown in the figure, the liquid ejecting head H includes a plurality of (two in this embodiment) head chips Hc, a first flow channel unit 200 , a relay substrate 210 , a second flow channel unit 220 , a holder 230 , a cover 240 , a sealing member 250 , and a heater 260 .

[0031] Figure 5 2 is a cross-sectional view showing an example of the head chip Hc. In addition, each direction of the head chip Hc will be described based on the direction when it is mounted on the liquid ejecting head H, that is, the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0032] As shown in the figure, the head chip Hc includes a flow channel forming substrate 10 , a communication plate 15 , a nozzle plate 20 having a plurality of nozzles 21 formed thereon, a protection substrate 30 , a housing member 40 , a piezoelectric actuator 300 , and a first flexible substrate 110 .

[0033] The flow channel forming substrate 10 is composed of, for example, a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates. On the flow channel forming substrate 10, a plurality of pressure chambers 12 are arranged side by side along the X-axis direction. The plurality of pressure chambers 12 are arranged on a straight line along the X-axis direction in such a manner that they are at the same position in the Y-axis direction. In the present embodiment, two pressure chamber rows formed by arranging the pressure chambers 12 side by side along the X-axis direction are arranged in the Y-axis direction. The pressure chambers 12 constituting the two pressure chamber rows are arranged at the same position in the X-axis direction. In addition, the two pressure chamber rows may be arranged in such a manner that they are staggered from each other by half of the spacing of the pressure chambers 12 in the X-axis direction, i.e., the so-called half spacing. In other words, all the pressure chambers 12 in the two pressure chamber rows may also be arranged in a staggered manner along the X-axis direction.

[0034] The communication plate 15 and the nozzle plate 20 are sequentially stacked on the surface of the flow path forming substrate 10 facing the +Z direction. The vibration plate 50 and the piezoelectric actuator 300 are sequentially stacked on the surface of the flow path forming substrate 10 facing the -Z direction.

[0035] The connecting plate 15 is composed of a plate-shaped member bonded to the surface of the flow channel forming substrate 10 facing the +Z direction. The connecting plate 15 is provided with a nozzle connecting channel 16 that connects the pressure chamber 12 and the nozzle 21. In addition, the connecting plate 15 is provided with a first manifold portion 17 and a second manifold portion 18 that constitute a part of the manifold 100 that becomes a common liquid chamber that is commonly connected to a plurality of pressure chambers 12. The first manifold portion 17 is provided in a manner that penetrates the connecting plate 15 in the Z-axis direction. In addition, the second manifold portion 18 is provided in a manner that does not penetrate the connecting plate 15 in the Z-axis direction but opens on the surface facing the +Z direction. Moreover, the connecting plate 15 is independently provided with a supply connecting channel 19 that communicates with the pressure chamber 12 for each pressure chamber 12. The supply connecting channel 19 connects the second manifold portion 18 with the pressure chamber 12, thereby supplying the ink in the manifold 100 to the pressure chamber 12. As such a connecting plate 15, a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, a metal substrate such as a stainless steel substrate, etc. can be used.

[0036] The nozzle plate 20 is bonded to the side of the connecting plate 15 opposite to the flow channel forming substrate 10, that is, the surface facing the +Z direction. On the nozzle plate 20, a plurality of nozzles 21 are formed that are connected to each pressure chamber 12 via the nozzle connecting channel 16. In the present embodiment, for each pressure chamber column, a plurality of nozzles 21 are arranged side by side in a row along the X-axis direction. That is, in the present embodiment, the nozzle column formed by arranging the nozzles 21 side by side along the X-axis direction is arranged in two columns separated in the Y-axis direction. The nozzles 21 constituting the two nozzle columns are arranged in the same position in the X-axis direction. Of course, in the case where the two pressure chamber columns are arranged at positions that are offset from each other by half the pitch of the pressure chamber 12 in the X-axis direction, the two nozzle columns can also be arranged in a manner that is staggered from each other by half the pitch of the nozzles 21 in the X-axis direction. That is, all the nozzles 21 of the two nozzle columns can also be arranged in a staggered manner along the X-axis direction.

[0037] As such nozzle plate 20, silicon substrate, glass substrate, SOI substrate, various ceramic substrates, metal substrates such as stainless steel substrates, organic materials such as polyimide resin, etc. can be used. The surface of nozzle plate 20 facing the +Z direction constitutes a part of the ejection surface of liquid ejecting head H.

[0038] In the present embodiment, the vibration plate 50 includes 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 of the elastic film 51 facing the -Z direction. In addition, the vibration plate 50 may be composed of only the elastic film 51, or only the insulating film 52, or may have a structure including other films in addition to the elastic film 51 and the insulating film 52.

[0039] The piezoelectric actuator 300 includes a first electrode 60, a piezoelectric layer 70, and a second electrode 80 which are stacked in sequence on a vibration plate 50 in the -Z direction. Such a piezoelectric actuator 300 is also referred to as a piezoelectric element, which refers to a portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. In addition, when a voltage is applied between the first electrode 60 and the second electrode 80, the portion in which piezoelectric deformation occurs on the piezoelectric layer 70 is referred to as 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 plurality of active portions 310 are referred to as "driving elements" that cause pressure changes in the ink in the pressure chamber 12. In general, one electrode of the active portion 310 is configured as an independent electrode independent of each active portion 310, and the other electrode is configured as a common electrode shared by a plurality of active portions 310. In this embodiment, the first electrode 60 is divided for each active portion 310 and constitutes an independent electrode of the active portion 310, and the second electrode 80 is continuously provided across a plurality of active portions 310 and constitutes a common electrode of the plurality of active portions 310. Of course, the first electrode 60 may constitute a common electrode, and the second electrode 80 may constitute an independent electrode.

[0040] The piezoelectric layer 70 is formed using, for example, a piezoelectric material composed of a composite oxide having a perovskite structure represented by the general formula ABO 3 .

[0041] In addition, an independent lead electrode 91 as a lead wiring is led out from the first electrode 60. In addition, a common lead electrode as a lead wiring (not shown) is led out from the second electrode 80. A first flexible substrate 110 having flexibility is connected to the ends of these independent lead electrodes 91 and the common lead electrode on the opposite side of the ends connected to the piezoelectric actuator 300. A drive signal selection circuit 111 is mounted on the first flexible substrate 110, and the drive signal selection circuit 111 has a plurality of switch elements for selecting whether to supply a drive signal COM for driving each active portion 310 to each active portion 310. That is, the first flexible substrate 110 in this embodiment is a COF (Chip On Film). In addition, the drive signal selection circuit 111 may not be provided on the first flexible substrate 110. That is, the first flexible substrate 110 may also be an FFC (Flexible Flat Cable), an FPC (Flexible Printed Circuits), or the like.

[0042] A protective substrate 30 having substantially the same size as the flow channel forming substrate 10 is bonded to the surface of the flow channel forming substrate 10 facing the -Z direction. The protective substrate 30 has a housing portion 31 as a space for protecting the piezoelectric actuator 300. The housing portion 31 is a portion independently provided for each column of the piezoelectric actuators 300 arranged side by side in the X-axis direction, and two are formed side by side in the Y-axis direction. In addition, a through hole 32 penetrating in the Z-axis direction is provided between the two housing portions 31 arranged side by side in the Y-axis direction on the protective substrate 30. The ends of the independent lead electrodes 91 and the common lead electrodes (not shown) drawn from the electrodes of the piezoelectric actuators 300 extend in a manner exposed in the through hole 32, and the independent lead electrodes 91 and the common lead electrodes are electrically connected to the first flexible substrate 110 in the through hole 32. As such a protective substrate 30, for example, a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, etc. can be used in the same manner as the flow channel forming substrate 10.

[0043] In addition, a shell member 40 is fixed to the protective substrate 30, which defines a part of the manifold 100 connected to the plurality of pressure chambers 12. The shell member 40 has a shape substantially the same as the above-mentioned connecting plate 15 when viewed from a plane, is joined to the protective substrate 30, and is also joined to the above-mentioned connecting plate 15. Such a shell member 40 has a recess 41 of a depth for accommodating the flow channel forming substrate 10 and the protective substrate 30 on the protective substrate 30 side. In addition, a third manifold portion 42 connected to the first manifold portion 17 of the connecting plate 15 is provided on the shell member 40. Moreover, the manifold 100 of the present embodiment is constituted by the first manifold portion 17 and the second manifold portion 18 provided on the connecting plate 15 and the third manifold portion 42 provided on the shell member 40. The manifold 100 is provided for each nozzle column. That is, different types of ink can be ejected for each nozzle column. In addition, the housing member 40 is provided with an inlet 44 that communicates with the manifold 100 and is used to supply ink to each manifold 100. In addition, the housing member 40 is 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 of the liquid ejecting head H facing the -Z direction through the connection port 43. As the housing member 40, for example, a metal material, a resin material, or the like can be used.

[0044] In addition, a plastic substrate 45 is provided on the surface of the +Z direction side where the first manifold portion 17 and the second manifold portion 18 of the communication plate 15 are opened. The plastic substrate 45 seals the openings of the first manifold portion 17 and the second manifold portion 18 on the +Z direction side. In the present embodiment, such a plastic 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 completely removed in the thickness direction is provided in the region of the fixed substrate 47 facing the manifold 100, and one surface of the manifold 100 becomes a flexible portion, that is, a plastic portion 49 sealed only by the flexible sealing film 46. The surface of the fixed substrate 47 facing the +Z direction is fixed to the surface of the cover 240 facing the -Z direction by adhesive or the like, so that the head chip Hc is fixed to the cover 240. The cover 240 is a common component fixed to each of the fixed substrates 47 of a plurality of (two in the present embodiment) head chips Hc. Therefore, the two head chips Hc are integrated by the cover cap 240. The surface of the cover cap 240 facing the +Z direction constitutes a part of the ejection surface.

[0045] In such a head chip Hc, liquid is introduced from the inlet 44, and the flow channel is filled with ink from the manifold 100 to the nozzle 21. Then, a voltage is applied to each active portion 310 corresponding to the pressure chamber 12 according to a signal from the drive signal selection circuit 111, so that the vibration plate 50 is flexed and deformed together with the piezoelectric actuator 300. As a result, the pressure of the liquid in the pressure chamber 12 increases, and droplets are ejected from the predetermined nozzle 21.

[0046] The first flow channel unit 200 and the second flow channel unit 220 supply the ink from the liquid storage portion 3 to the head chip Hc.

[0047] Here, if Figures 2 to 4 As shown, in the first flow channel unit 200, the first flow channel component 201, the second flow channel component 202, and the third flow channel component 203 are stacked in this order toward the +Z direction.

[0048] The first flow channel component 201 has a first connection portion 204 connected to a liquid storage portion 3 storing liquid. In the present embodiment, the first connection portion 204 is provided in a cylindrical shape on the surface of the first flow channel component 201 facing the -Z direction and protruding in the -Z direction. The liquid storage portion 3 can be directly connected to the first connection portion 204, or the liquid storage portion 3 can be connected via a supply pipe such as a tube. Inside the first connection portion 204, a first flow channel 401 for supplying liquid from the liquid storage portion 3 is provided. In addition, the first flow channel 401 is extended along the stacking interface between the first flow channel component 201 and the second flow channel component 202. That is, the first flow channel 401 has a portion formed along the Z-axis direction and a portion formed along a direction orthogonal to the Z-axis direction.

[0049] The second flow channel member 202 has a second flow channel 402 communicating with the first flow channel 401. The second flow channel 402 is provided along the Z-axis direction. In addition, a first liquid reservoir 402a having an inner diameter greatly expanded compared to other regions is provided at the end of the second flow channel 402 in the +Z direction.

[0050] The third flow channel component 203 has a third flow channel 403 connected to the second flow channel 402. The third flow channel 403 is arranged along the Z-axis direction. In addition, a second liquid storage portion 403a having an inner diameter greatly widened compared to other areas is provided at one end portion of the third flow channel 403 in the -Z direction. Moreover, a filter F is provided on the stacking interface between the second flow channel component 202 and the third flow channel component 203 so as to divide the first liquid storage portion 402a and the second liquid storage portion 403a. The filter F captures foreign matter such as dust and bubbles contained in the ink.

[0051] The other end of the third flow channel 403 opens on the surface of the third flow channel member 203 facing the +Z direction, and is connected to the fifth flow channel 405 of the second flow channel unit 220 in a liquid-tight state via the sealing member 250. The sealing member 250 is formed of an elastic member such as rubber, and a flow channel communication channel 251 penetrating in the Z-axis direction is provided on the sealing member 250. The third flow channel 403 and the fourth flow channel 404 are communicated via the flow channel communication channel 251.

[0052] The second flow channel unit 220 is configured by stacking a fourth flow channel member 221 and a fifth flow channel member 222 in the +Z direction.

[0053] On the fourth flow channel component 221, on the surface facing the -Z direction, there is a cylindrical second connection portion 223 protruding in the -Z direction. Inside the second connection portion 223, a fourth flow channel 404 for supplying liquid from the third flow channel 403 is provided. In addition, the fourth flow channel 404 is extended along the stacking interface between the fourth flow channel component 221 and the fifth flow channel component 222. In other words, the fourth flow channel 404 has a portion formed along the Z-axis direction and a portion formed along a direction orthogonal to the Z-axis direction. The end of the second connection portion 223 in the -Z direction is inserted into the first connection portion insertion hole 214 provided on the relay substrate 210, the details of which will be described later, and the fourth flow channel 404 is connected to the third flow channel 403 of the third flow channel component 203 in the -Z direction of the relay substrate 210 via the flow channel connecting channel 251 of the sealing component 250 in a liquid-tight manner.

[0054] The fifth flow channel component 222 has a cylindrical third connection portion 224 protruding in the +Z direction on the surface facing the +Z direction. A fifth flow channel 405 is provided inside the third connection portion 224. The end of the fifth flow channel 405 in the -Z direction is connected to the fourth flow channel 404, and the end of the fifth flow channel 405 in the +Z direction is inserted into the second connection portion insertion hole 235 of the retainer 230, which will be described in detail later, and is connected to the introduction port 44 of the head chip Hc in the storage space 233 of the retainer 230. In other words, the end surface of the second connection portion 223 in the +Z direction is fixed to the surface of the housing component 40 of the head chip Hc facing the -Z direction. The fixing of the second connection portion 223 to the head chip Hc can be listed as bonding via an adhesive, heat welding, ultrasonic welding, etc. Preferably, the second flow channel unit 220 and the head chip Hc are bonded via an adhesive. By bonding the two with an adhesive in this manner, the fifth flow channel 405 and the introduction port 44 of the head chip Hc are connected liquid-tightly, and leakage of ink can be suppressed.

[0055] In addition, the second flow channel unit 220 is provided with a first wiring insertion hole 225 penetrating in the Z-axis direction. The first wiring insertion holes 225 will be described in detail later, and the first flexible substrate 110 of the head chip Hc and the lead wiring portion of the heater 260 are respectively inserted through the first wiring insertion holes 225. Therefore, in this embodiment, four first wiring insertion holes 225 are provided.

[0056] In this embodiment, the second flow channel unit 220 is an example of a “flow channel component”, and the fourth flow channel 404 and the fifth flow channel 405 are an example of a “flow channel”. Figure 3 As shown in the figure, the second flow channel unit 220 as an example of the "flow channel member" includes four "flow channels" corresponding to the four nozzle columns, respectively, and composed of the fourth flow channel 404 and the fifth flow channel 405. However, the second flow channel unit 220 as an example of the "flow channel member" may also be a structure including a single "flow channel" for distributing and supplying liquid to the four nozzle columns.

[0057] The relay substrate 210 is arranged between the sealing member 250 and the second flow channel unit 220. The first flexible substrates 110 of the plurality of head chips Hc are electrically connected to the relay substrate 210 in common. In addition, the relay substrate 210 is electrically connected to the heater 260. The relay substrate 210 is composed of a hard rigid substrate that is not flexible, and is installed with wiring, electronic components, etc. shown in the figure. In this embodiment, as an example of an electronic component, a connector 211 connected to an external wiring (not shown) provided outside the liquid jet head H is shown. Moreover, a printing signal for controlling the head chip Hc is input from the external wiring via the connector 211 to the relay substrate 210, and is supplied from the relay substrate 210 to each head chip Hc. In addition, on the side wall of the holder 230, which will be described in detail later and is opposite to the connector 211, an external wiring opening 238 for inserting the external wiring connected to the connector 211 is provided. The external wiring is connected to the connector 211 of the relay substrate 210 provided inside the holder 230 through the external wiring opening 238 .

[0058] Furthermore, the relay substrate 210 has a first through hole 212 for leading the first flexible substrate 110 of the head chip Hc to the surface side facing the -Z direction. One first through hole 212 is provided for each head chip Hc, and two first through holes 212 are provided in total.

[0059] The relay substrate 210 has second through holes 213 for leading out the lead wiring portion 280 of the heater 260, which will be described in detail later, to the surface side facing the -Z direction. One second through hole 213 is provided for each heater 260, and two second through holes 213 are provided in total.

[0060] In addition, when viewed along the Z-axis direction, the opening areas of the first through hole 212 and the second through hole 213 are substantially the same. Here, “substantially the same” means that the difference between the opening areas of the two is within 20%. The size of the second through hole 213 is such that the first flexible substrate 110 can be inserted therethrough.

[0061] In addition, the relay substrate 210 of the present embodiment can use a substrate having substantially the same shape as a relay substrate used in a liquid ejecting head that holds four head chips Hc in the storage space 233. That is, a part of the four first through holes 212 formed on the relay substrate of the liquid ejecting head that holds the four head chips Hc and through which the four first flexible substrates 110 are respectively inserted can be used as the second through holes 213 through which the heater 260 is inserted.

[0062] In addition, a first connection portion insertion hole 214 is provided on the relay substrate 210 and is provided in the Z-axis direction. The second connection portion 223 of the second flow channel unit 220 is inserted to the -Z direction side of the relay substrate 210 via the first connection portion insertion hole 214, and is connected to the third flow channel 403 of the first flow channel unit 200 via the flow channel communication passage 251 of the sealing member 250. That is, two first connection portion insertion holes 214 are provided for each head chip Hc, and a total of four are provided.

[0063] The holder 230 has a first recess 231 opened on the surface facing the +Z direction. The first recess 231 is defined by the outer peripheral wall 232. The holder 230 defines a storage space 233 inside by the first recess 231 and the cover 240 by fixing the cover 240 on the end surface in the +Z direction, that is, the end surface of the outer peripheral wall 232. The storage 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 divided by the partition 234. In the present embodiment, when viewed along the Z-axis direction, the first space 233a is sandwiched by two second spaces 233b in a plan view. That is, in a plan view, the second spaces 233b are respectively arranged on both sides of the first space 233a in the Y-axis direction. In the present embodiment, the first space 233a is arranged in a manner sandwiched between the two second spaces 233b in the Y-axis direction. That is, the partition wall 234 is arranged at a position closer to the head chip Hc than the portion 232a of the peripheral wall 232 in the Y-axis direction in which the portion 232a of the peripheral wall 232, the second space 233b, and the plurality of head chips Hc are arranged. Incidentally, the portion 232a of the peripheral wall 232 refers to the portions on both sides of the peripheral wall 232 in the Y-axis direction. By arranging the partition wall 234 at a position closer to the head chip Hc than the portion 232a of the peripheral wall 232, the heat conducted to the holder 230 from the heater 260, which will be described in detail later, can be effectively conducted to the head chip Hc via the partition wall 234.

[0064] In addition, if Figure 3 as well as Figure 4 As shown, the peripheral wall portion 232 has a plurality of ribs 232b protruding toward the next wall portion 234. The ribs 232b protrude from the peripheral wall portion 232 toward the next wall portion 234 along the Y-axis direction, and are continuously arranged across the Z-axis direction of the storage space 233. A plurality of ribs 232b are arranged in the Y-axis direction at predetermined intervals. By arranging the ribs 232b in this way, the rigidity of the peripheral wall portion 232 can be improved, and the deformation or damage of the retainer 230 can be suppressed. In addition, although the ribs 232b are arranged on the peripheral wall portion 232 in the present embodiment, it is not particularly limited thereto, and the ribs 232b can also be arranged on the next wall portion 234, and the ribs 232b can also be arranged on both the peripheral wall portion 232 and the next wall portion 234.

[0065] A head chip Hc is stored in the first space 233a of such a storage space 233. In the present embodiment, two head chips Hc are stored in one first space 233a. A second connection portion insertion hole 235 that penetrates the retainer 230 is provided on the surface of the inner surface of the first space 233a located in the -Z direction, that is, on the bottom surface of the first recess 231. Since two head chips Hc are stored in the first space 233a, two second connection portion insertion holes 235 are provided for each head chip Hc, and a total of four are provided. The third connection portion 224 inserted through the second connection portion insertion hole 235 is bonded to the head chip Hc in the first space 233a via an adhesive not shown in the figure. The adhesive for bonding the head chip Hc and the third connection portion 224 can use an adhesive with high corrosion resistance to ink, for example, an epoxy adhesive can be used.

[0066] In addition, each head chip Hc is bonded to the bottom surface of the first recess 231 via an adhesive not shown. The adhesive for bonding the holder 230 and the head chip Hc is, for example, composed of an ultraviolet curing adhesive, and temporarily fixes the holder 230 and the head chip Hc. That is, after the holder 230 and the head chip Hc are temporarily fixed and positioned by the ultraviolet curing adhesive, the third connecting portion 224 of the second flow channel unit 220 and the head chip Hc are formally fixed by the adhesive, thereby suppressing the relative positional deviation of the holder 230 and the second flow channel unit 220 and the head chip Hc, and further suppressing the leakage of ink at the connecting portion of the flow channel.

[0067] In addition, although the head chip Hc and the bottom surface of the first recessed portion 231 of the holder 230 are bonded together in the present embodiment, the present invention is not particularly limited thereto, and the head chip Hc and the holder 230 may not be directly bonded together.

[0068] In addition, the holder 230 has a through hole that communicates the storage space 233 with the -Z direction of the holder 230, that is, a second wiring insertion hole 236. The second wiring insertion hole 236 allows the first flexible substrate 110 of the head chip Hc stored in the storage space 233 to be inserted, 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, a total of two second wiring insertion holes 236 are provided, and the two second wiring insertion holes 236 are arranged at a position that communicates with the first space 233a, that is, overlaps with the first space 233a for storing the head chip Hc when viewed along the Z-axis direction. In addition, the holder 230 of the present embodiment is formed by providing the partition wall portion 234 and the rib portion 232b for the holder that holds four head chips Hc in the storage space 233. Therefore, the second wiring insertion hole 236 is also provided at a position communicating with the second space 233b, that is, at a position overlapping with each second space 233b when viewed along the Z-axis direction. Of course, the second wiring insertion hole 236 communicating with the second space 233b may not be provided.

[0069] In addition, although in this embodiment, the second wiring insertion hole 236 and the second connection portion insertion hole 235 communicating with the first space 233a are provided independently of each other, this is not particularly limited to this, and the second wiring insertion hole 236 and the second connection portion insertion hole 235 may also be provided in a partially continuous manner.

[0070] In such a liquid ejecting head H, the 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. That is, the holder 230 does not define a flow path through which the ink flows.

[0071] In addition, the materials of the second flow channel unit 220 and the retainer 230 will be described later.

[0072] A cover 240 is fixed to the surface of the retainer 230 facing the +Z direction, that is, the end surface of the outer peripheral wall portion 232 in the +Z direction and the end surface of the partition portion 234 in the +Z direction. The cover 240 is made of a metal plate such as stainless steel, and has a size that blocks the opening of the first recess 231 of the retainer 230. The storage space 233 is defined in the first recess 231 of the retainer 230 by the cover 240. The cover 240 is a common component fixed to the surfaces of the two head chips Hc facing the +Z direction. In addition, an exposure opening 241 is provided on the cover 240 to expose the nozzle 21 of the head chip Hc in the +Z direction. The exposure opening 241 is independently provided for each head chip Hc. The ink is ejected in the form of droplets from the nozzle 21 exposed in the exposure opening 241 toward the +Z direction.

[0073] In addition, as described above, in the present embodiment, the bottom surface of the first recess 231 of the retainer 230 is fixed to the head chip Hc, but the bottom surface of the first recess 231 of the retainer 230 may not be fixed to the head chip Hc. Even if the bottom surface of the first recess 231 of the retainer 230 is not fixed to the head chip Hc, the retainer 230 retains the head chip Hc via the cover 240. In other words, "the retainer 230 retains the head chip Hc" includes a case where the retainer 230 is directly fixed to and retains the head chip Hc, a case where the retainer 230 indirectly retains the head chip Hc via the cover 240 and the second flow channel unit 220 although the retainer 230 is not directly fixed to the head chip Hc, and the like.

[0074] In the present embodiment, the cover 240 is an example of a “fixed plate.” Alternatively, a reinforcing plate thicker than the cover 240 may be provided between the cover 240 and the retainer 230. In this case, the cover 240 and the reinforcing plate are examples of a “fixed plate.”

[0075] The holder 230 has a second recess 237 opened in the -Z direction on the surface facing the -Z direction. The second recess 237 has substantially the same size as the first recess 231 when viewed in the Z-axis direction, and is disposed at a position substantially overlapping the first recess 231. A heater 260 is provided on the bottom surface of the second recess 237 facing the -Z direction to heat the ink in the head chip Hc via the holder 230.

[0076] The heater 260 of the present embodiment is constituted by a thin film heater. The heater 260 is arranged on the bottom surface of the second recess 237 of the retainer 230 at a position overlapping with the second space 233b when viewed along the Z-axis direction. In the present embodiment, a total of two heaters 260 are provided at positions overlapping with the two second spaces 233b, respectively. In addition, in the present embodiment, as described above, the first space 233a is arranged at a position sandwiched by the two second spaces 233b when viewed along the Z-axis direction. Therefore, by arranging the heater 260 at a position overlapping with the second space 233b, the first space 233a is arranged at a position sandwiched by the two heaters 260. That is, the head chip Hc accommodated in the first space 233a is arranged at a position sandwiched by the two heaters 260. Therefore, the head chip Hc can be efficiently heated by the two heaters 260.

[0077] Furthermore, the two heaters 260 are arranged line-symmetrically about the axis along the X-axis direction when viewed in the Z-axis direction. Thus, there is no need to separately manufacture two types of heaters 260, and one type of heater 260 can be used to reduce costs.

[0078] Figure 6 is a cross-sectional view of the heater 260 . Figure 7 This is a plan view of the main surface portion 270 and the lead wiring portion 280 of the heater 260 before being bent. Figure 8 It is a plan view showing a modification of the heater before the main surface portion 270 and the lead wiring portion 280 are bent. Fig. 9 2 is a diagram schematically showing the wiring of the heater 260 and the relay substrate 210 . Fig.10 1 is a schematic diagram showing a modified example of wiring between the heater 260 and the relay substrate 210 .

[0079] like Figure 6 as well as Figure 7 As shown, the heater 260 includes a main surface portion 270 and a lead wiring portion 280 .

[0080] The main surface portion 270 includes a first base material 271 , a resistance wire 272 , a temperature detection element 273 , and relay wiring 274 .

[0081] 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.

[0082] The first base material 271 has a communicating hole 275 communicating with the second wiring insertion hole 236 of the holder 230 , and is provided in a ring shape when viewed in the Z-axis direction.

[0083] Preferably, the resistance wire 272 has a resistivity of 1.00×10 -6 The heating wire 272 is formed of a metal with a resistance of Ω·m. For example, the heating wire is a nickel-chromium alloy wire, a Kanthal wire formed of an iron-chromium-aluminum alloy, etc. In addition, the resistance wire 272 can also be made of stainless steel (SUS) with a slightly lower resistivity than the heating wire or copper (Cu) with a lower resistivity than the heating wire. Such a resistance wire 272 is set on the first surface 271a of the first substrate 271. Figure 7 As shown in FIG. 1 , the resistance wire 272 is arranged to meander across the circumference of the annular first substrate 271 when viewed along the Z-axis direction. Figure 8 As shown, the resistance wire 272 can also be arranged in a straight line along the circumferential direction. Figure 7 as well as Figure 8 In any case, the resistance wire 272 is formed in a ring shape spanning the circumference of the communicating hole 275 .

[0084] The cross-sectional area of ​​the resistance wire 272 is determined by its width and thickness so as to obtain a resistivity that provides the best heat to the holder 230. For example, when the resistance wire 272 is made of copper (Cu), since the resistivity is lower than that of the heating wire, it only needs to be formed thin and long. The thickness of the resistance wire 272 is, for example, 12 μm.

[0085] The temperature detection element 273 is composed of, for example, a thermistor or a temperature measuring resistor, and is disposed on the second surface 271b side of the first substrate 271. In addition, the temperature detection element 273 is disposed at a position that does not overlap with the resistance wire 272 when viewed along the thickness direction of the first substrate 271, i.e., the Z-axis direction. In the present embodiment, the temperature detection element 273 is disposed at the end of the first substrate 271, and the resistance wire 272 is not disposed at the end of the first substrate 271. Thus, the temperature detection element 273 and the resistance wire 272 do not overlap each other in the Z-axis direction. By disposing the temperature detection element 273 at a position that does not overlap with the resistance wire 272 when viewed along the Z-axis direction, the temperature detection element 273 will not detect the instantaneous temperature rise of the resistance wire 272, and the temperature detection element 273 will detect the temperature of the retainer 230 as the heat transfer object, so that the temperature detection element 273 can measure the temperature of the retainer 230 more accurately.

[0086] In addition, the temperature detection element 273 is arranged outside the resistance wire 272 arranged in a ring shape, that is, arranged on the side of the resistance wire 272 opposite to the connecting hole 275. In this way, even if the temperature detection element 273 is arranged outside the resistance wire 272 in order to detect the temperature of the head chip Hc with high accuracy by using the temperature detection element 273, and thus arranged near the head chip Hc of the holder 230, the resistance wire 272 and the relay wiring 274 can be arranged in an overlapping manner when viewed along the Z-axis direction, thereby avoiding enlargement of the main surface 270.

[0087] The relay wiring 274 is disposed on the second surface 271b of the first substrate 271, and is electrically connected to the temperature detection element 273. In addition, the relay wiring 274 overlaps with the resistance wire 272 when viewed along the Z-axis direction. Here, "the relay wiring 274 overlaps with the resistance wire 272 when viewed along the Z-axis direction" means that they at least partially overlap with each other. By disposing the relay wiring 274 and the resistance wire 272 on different surfaces of the first substrate 271 in this way, the main surface 270 of the heater 260 can be miniaturized compared to the case where they are disposed on the same surface. In addition, by arranging the relay wiring 274 and the resistance wire 272 at positions where they overlap when viewed along the Z-axis direction, the main surface 270 of the heater 260 can be further miniaturized. In addition, as Figure 7As shown, it is preferred that the extension directions of the relay wiring 274 and the resistance wire 272 are different from each other when viewed along the Z-axis direction. By setting the extension directions of the relay wiring 274 and the resistance wire 272 to different directions and making them cross, it is possible to suppress the relay wiring 274 from being affected by noise generated by the switch control of the resistance wire 272, the so-called PWM control of power control using semiconductors, etc., thereby improving the measurement accuracy of the temperature detection element 273. In addition, as Figure 8 As shown, when viewed along the Z-axis direction, the extension direction of the relay wiring 274 and the resistance wire 272 may also be the same direction. By setting the extension direction of the relay wiring 274 and the resistance wire 272 to the same direction, the resistance wire 272 can be extended in the planar direction, so that it is easy to transfer heat in the planar direction through the resistance wire 272. In other words, the heat generated by the resistance wire 272 can be transferred in the planar direction through the first substrate 271 and the resistance wire 272 itself, so that the retainer 230 can be heated in a larger area with less temperature deviation. The thickness of such a relay wiring 274 is, for example, 12 μm.

[0088] The lead wiring section 280 is connected to the main surface 270 through the connection section 261. The lead wiring section 280 is bent approximately 90 degrees from the main surface 270. In addition, the lead wiring section 280 has an insulating second substrate 281 that is continuous with the first substrate 271. That is, the first substrate 271 and the second substrate 281 are formed by bending a continuous substrate approximately 90 degrees. Here, the second substrate 281 has a third surface 281a continuous with the first surface 271a of the first substrate 271 and a fourth surface 281b continuous with the second surface 271b of the first substrate 271.

[0089] Furthermore, the lead wiring section 280 includes a first lead wiring 282 and a second lead wiring 283 .

[0090] The first lead wiring 282 is electrically connected to the resistance wire 272. The first lead wiring 282 is provided on the third surface 281a of the second substrate 281. The first lead wiring 282 extends in a direction intersecting the first substrate 271. Here, the "direction intersecting the first substrate 271" refers to a direction intersecting the surface direction of the first substrate 271, including a direction perpendicular to the first substrate 271 and a direction inclined relative to the perpendicular direction.

[0091] The second lead wiring 283 is electrically connected to the relay wiring 274. The second lead wiring 283 extends in a direction intersecting the first base material 271 similarly to the first lead wiring 282.

[0092] The second lead-out wiring 283 includes a first portion 283a disposed on the third surface 281a, and a second portion 283b electrically connected to the first portion 283a via a through hole 281c penetrating the second substrate 281 and disposed on the fourth surface 281b. That is, the first portion 283a disposed on the third surface 281a is electrically connected to the second portion 283b disposed on the fourth surface 281b via a through hole 281c penetrating the second substrate 281. In the structure in which the second lead-out wiring 283 and the resistance wire 272 are led to the same fourth surface 281b, a portion of the second lead-out wiring 283 is led to the fourth surface 281b via a through hole 281c disposed on the second substrate 281, thereby eliminating the need to lead the resistance wire 272 to the fourth surface 281b via a through hole, and a larger current can be passed through the resistance wire 272 to efficiently heat the resistance wire 272.

[0093] Preferably, the first lead wiring 282, the second lead wiring 283 and the relay wiring 274 use materials with lower resistivity as much as possible. As such a material, for example, one selected from silver (Ag), copper (Cu), gold (Au), aluminum (Al), platinum (Pt), tin (Sn) or a combination of two or more can be used. In addition, the first lead wiring 282, the second lead wiring 283 and the relay wiring 274 do not have a winding part compared with the resistance wire 272. In addition, although it is impossible to set circuit elements in the middle of the resistance wire 272, it is possible to set circuit elements in the middle of the first lead wiring 282, the second lead wiring 283 and the relay wiring 274. Moreover, compared with the resistance wire 272, the cross-sectional area of ​​the first lead wiring 282, the second lead wiring 283 and the relay wiring 274 is smaller.

[0094] At the end of the lead wiring portion 280 on the opposite side from the connection portion 261, a portion of the first lead wiring 282 and the second lead wiring 283 that is not covered by the cover layer 262 described later and exposed to the outside, that is, a connection terminal portion 284 is provided. The connection terminal portion 284 is inserted through the second through hole 213 of the relay substrate 210, and is led out to the -Z direction side of the relay substrate 210, and is 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 portion 280 can be achieved by welding such as soldering or brazing, welding, bonding via a conductive adhesive, etc.

[0095] In addition, if Fig. 9As shown, the two heaters 260 may be independently wired on the relay substrate 210. In addition, the temperature detection elements 273 of the two heaters 260 are used separately. That is, the relay wiring 274 of the temperature detection elements 273 of the two heaters 260 are respectively wired to the connector 211. By independently wiring the two heaters 260 on the relay substrate 210 in this way, the two heaters 260 can be independently controlled, and the deviation of the temperature distribution of the holder 230 can be suppressed, thereby implementing high-precision temperature control.

[0096] In addition, if Fig.10 As shown, the two heaters 260 may also be wired in series on the relay substrate 210. The resistance wire 272 of one heater 260 and the resistance wire 272 of another heater 260 may be connected in series on the relay substrate 210. In this case, the temperature detection element 273 of one heater 260 may be used without using the temperature detection element 273 of the other heater 260. That is, the relay wiring 274 of the temperature detection element 273 of one heater 260 may be wired to the connector 211 without wiring the relay wiring 274 of the temperature detection element 273 of the other heater 260 to the connector 211. By connecting the two heaters 260 in series on the relay substrate 210 in this way, it is not necessary to implement independent control of the two heaters 260, and the control of the heaters 260 can be easily implemented.

[0097] In addition, the resistance wire 272 is arranged between the connection portion 261 of the main surface portion 270 and the lead wiring portion 280 and the temperature detection element 273 when viewed along the Z-axis direction. Even in such a structure in which the resistance wire 272 is arranged between the connection portion 261 and the temperature detection element 273, the resistance wire 272 and the relay wiring 274 can be arranged so as to overlap with each other when viewed along the Z-axis direction to avoid enlarging the main surface portion 270.

[0098] In addition, the temperature detection element 273 is arranged at a position closer to the nozzle 21 than the connection portion 261. By providing the temperature detection element 273 at a position close to the nozzle 21, the temperature of the nozzle 21 side can be detected with high accuracy by the temperature detection element 273. In addition, by arranging the connection portion 261 at a position far from the nozzle 21, although the heater 260 is relatively easy to be enlarged, by wiring the resistance wire 272 and the relay wiring 274 on different surfaces, there is no need for a space for wiring the resistance wire 272 and the relay wiring 274 on the same surface, and the enlargement of the heater 260 can be suppressed.

[0099] In addition, a cover layer 262 is provided on each of the surfaces facing the first surface 271a and the third surface 281a, and the surfaces facing the second surface 271b and the fourth surface 281b of the main surface 270 and the lead wiring portion 280. The cover layer 262 is composed of an insulating sheet such as polyimide, for example. The thickness of the cover layer 262 is, for example, 30 μm.

[0100] The main surface 270 of such a heater 260 is fixed to the holder 230 as the heating object on the surface facing the same direction as the direction facing the first surface 271a. By fixing the surface facing the first surface 271a of the main surface 270 provided with the resistance wire 272 to the holder 230 in this way, the heat of the resistance wire 272 can be efficiently conducted to the holder 230. Of course, the surface facing the second surface 271b of the main surface 270 can also be fixed to the holder 230, but the heat of the resistance wire 272 will be conducted to the holder 230 through the first substrate 271, so the efficiency of heat conduction will be reduced. In addition, the fixing method of fixing the heater 260 to the holder 230 is not particularly limited, and examples include bonding via an adhesive, double-sided tape, etc. In the present embodiment, the heater 260 is fixed to the holder 230 by a double-sided tape 263. The thickness of the double-sided tape 263 is, for example, 50μm.

[0101] In addition, if Figure 4 As shown, the heater 260 is arranged at a position where the area S1 of the portion of the heater 260 that overlaps with the storage space 233 but does not overlap with the head chip Hc when viewed along the Z-axis direction is larger than the area S2 of the region of the heater 260 that overlaps with the head chip Hc. The area S2 is the area of ​​the heater 260. Figure 4 The area indicated by the single-dot chain line in FIG. 2 is an area other than the area S1 in the portion where the heater 260 overlaps with the storage space 233. In this way, when the heater 260 is arranged at a position where the area S1 is larger than the area S2, that is, when there is a virtual second space 233b in which the head chip Hc is not arranged in the storage space 233, the heater 260 can be easily installed by arranging the heater 260 using the second space 233b. In addition, the heater 260 may be arranged at a position that does not overlap with the head chip Hc at all when viewed in the Z-axis direction.

[0102] The ink in the head chip Hc is heated by the heater 260 through the holder 230. Here, the heat of the heater 260 is conducted to the cover 240 through the peripheral wall portion 232 and the partition wall portion 234 of the holder 230. The heat conducted to the cover 240 is conducted to the connecting plate 15 through the plastic substrate 45, and the heat conducted to the connecting plate 15 is conducted to the nozzle plate 20, the flow channel forming substrate 10, and the housing member 40. In addition, since the cover 240 is formed of a metal with high thermal conductivity, the heat of the holder 230 is easily conducted to the head chip Hc through the cover 240.

[0103] In addition, in the present embodiment, since the housing member 40 of the head chip Hc is directly fixed to the holder 230, heat is directly transferred from the holder 230 to the housing member 40 of the head chip Hc. Moreover, the head chip Hc is stored in the storage space 233 of the holder 230, and the outer periphery except the +Z direction is covered by the holder 230. Therefore, the heat of the holder 230 heated by the heater 260 is transferred to the entire head chip Hc via the atmosphere in the storage space 233. In this way, the heater 260 heats the head chip Hc via the holder 230, thereby heating the ink in the head chip Hc.

[0104] In addition, 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 the present embodiment, as described above, the temperature detection element 273 is arranged at a position that does not overlap with the resistance wire 272 when viewed along the Z-axis direction, so that when the temperature of the resistance wire 272 rises instantaneously, it will not be detected by the temperature detection element 273, and the temperature detection element 273 can detect the temperature of the holder 230 as the heat transfer object. Therefore, the temperature detection element 273 can measure the temperature of the holder 230 more accurately, and can heat the holder 230 to the target temperature with high precision through the heater 260.

[0105] In addition, in this embodiment, the lead wiring portion is an example of a “second flexible substrate”.

[0106] Here, when a liquid having a high viscosity is to be ejected from the liquid ejection head H in a low temperature environment such as ultraviolet curing ink, it is difficult to eject the liquid from the nozzle 21 when the viscosity of the liquid is high. Therefore, it is necessary to heat the liquid in the liquid ejection head H by the aforementioned heater 260 to reduce the viscosity. Therefore, it is desirable to form the retainer 230, which is the heating object of the heater 260, from a material such as metal or ceramic having a high thermal conductivity. However, it is very expensive to form the retainer 230 having a complex shape from a material such as metal or ceramic. Therefore, it is desirable to form it from a resin material at a low price. However, since the retainer 230 formed of resin has a low thermal conductivity, there is a problem that the liquid in the liquid ejection head H cannot be sufficiently heated by the heater 260.

[0107] Therefore, the retainer 230 of the present embodiment is made of a thermally conductive resin. A thermally conductive resin refers to a resin that has thermal conductivity by making a resin matrix contain a thermally conductive filler. By forming the retainer 230 from a thermally conductive resin, it is easier to manufacture and reduce costs compared to the case where it is formed from metal or ceramics, and the ink in the head chip Hc can be effectively heated through the retainer 230 by the heater 260. In addition, since the retainer 230 does not define the flow channel, even if the retainer 230 is made of a thermally conductive resin, it is possible to prevent the thermally conductive filler from falling off from the resin material and mixing into the ink in the flow channel. Therefore, the possibility of the nozzle 21 being clogged by the falling thermally conductive filler, thereby causing poor ejection, can be reduced.

[0108] In addition, as a resin matrix used in the thermally conductive resin, for example, any resin can be appropriately selected from known thermoplastic resins for use. As examples of such thermoplastic resins, polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon 6, nylon 66, nylon 11, nylon 12, aromatic polyamides, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polycyclohexyl terephthalate, ABS resin, polycarbonate resin, modified polyphenylene ether resin, polyacetal resin, polyphenylene sulfide resin, fully aromatic polyester resin, polyetheretherketone resin, polyethersulfone resin, polysulfone resin, polyamideimide resin, and copolymer resins composed of two or more structural components of these resins can be cited. These thermoplastic resins can be used alone or in combination of two or more. In addition, as a resin matrix used in the thermally conductive resin, any resin can be appropriately selected from known thermosetting resins for use. Examples of such thermosetting resins include phenol resins, polyurethane, epoxy resins, and melamine resins.

[0109] As the thermally conductive filler contained in such a resin matrix, there is no particular limitation as long as the thermal conductivity is high, and various types of fillers can be used. Examples of such thermally conductive fillers include oxide powders such as aluminum oxide (also known as aluminum oxide), 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. High thermal conductive fillers can be used alone or in combination of two or more.

[0110] When the particle size of the above-mentioned high thermal conductivity filler becomes smaller, the viscosity of the admixture increases significantly during filling, and there is a tendency to be difficult to fill, and as a result, it is sometimes impossible to obtain a resin material with high thermal conductivity. In addition, when the particle size becomes larger, since the intervals between the thermally conductive fillers become narrower and they become easier to contact each other, heat becomes easier to transfer and there is a tendency for the thermal conductivity to become relatively high. In particular, in the present embodiment, since the retainer 230 does not define the flow channel, even if it is assumed that the particle size of the thermally conductive filler is larger and the thermally conductive filler is easy to peel off from the resin material, the peeled thermally conductive filler is difficult to mix into the ink. Therefore, the average particle size of the thermally conductive filler used in the thermally conductive resin is preferably greater than 80μm, more preferably greater than 90μm, and further preferably greater than 100μm. By forming the retainer 230 with such a thermally conductive resin containing a thermally conductive filler having an average particle size larger than the diameter of the nozzle 21, the thermal conductivity of the retainer becomes higher and the thermally conductive filler is not mixed into the ink, thereby suppressing the occurrence of problems such as clogging of the nozzle 21.

[0111] In addition, for example, when the thermally conductive filler is not spherical, 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 value. In addition, the measurement of the thermally conductive filler is carried out by directly photographing the thermally conductive filler or photographing a cross section of the thermally conductive filler in a state of being included in the thermally conductive resin.

[0112] In addition, it is preferred that the content of the thermally conductive filler is greater than 70% by volume relative to the total volume of the retainer 230. By forming the retainer 230 in which the content of the thermally conductive filler is greater than 70% by volume, the thermal conductivity of the retainer 230 can be improved. Of course, the content of the thermally conductive filler may be less than 70% by volume relative to the total volume of the retainer 230. Thus, the moldability can be improved. However, if the content of the thermally conductive filler is small, the thermal conductivity of the retainer 230 decreases. Therefore, the content of the thermally conductive filler is preferably greater than 30% by volume, and more preferably greater than 50% by volume relative to the total volume of the retainer 230.

[0113] In addition, in the thermally conductive resin material, other fillers, flame retardants, heat resistance improvers, weather resistance improvers and other additives can be mixed as needed. As the above-mentioned other fillers, mica or talc, or carbon fiber, silicon fiber and other fibers or whiskers and other fillers with great reinforcing effects can be listed. Here, as specific examples of whiskers, non-oxide whiskers composed of silicon carbide, silicon nitride, etc., metal oxide whiskers composed of ZnO, MgO, TiO2, SnO2, Al2O3, etc., double oxide whiskers composed of potassium titanate, aluminum borate, basic magnesium sulfate, etc. can be listed, and among these whiskers, double oxide whiskers are preferably used in view of the ease of compounding with plastics.

[0114] In addition, the first thermal conductivity of the holder 230 in the thickness direction of the heater 260, i.e., the Z-axis direction, is greater than the second thermal conductivity in the direction along the surface direction of the heater 260, i.e., along the XY plane. In addition, the first thermal conductivity is preferably three times or more of the second thermal conductivity.

[0115] In other words, the first thermal conductivity is the thermal conductivity in the direction in which the heater 260, a portion of the holder 230 sandwiched by the heater 260 and the head chips Hc, and the head chips Hc are arranged.

[0116] In other words, the first thermal conductivity is the thermal conductivity in the direction perpendicular to the surface of the holder 230 facing the opposite side to the surface fixed to the cover 240, that is, the surface of the holder 230 on which the heater 260 is arranged, that is, the Z-axis direction. In addition, the second thermal conductivity is the thermal conductivity in the direction parallel to the surface of the holder 230 on which the heater 260 is arranged.

[0117] That is, the heat of the heater 260 easily moves in the holder 230 along the Z-axis direction, and thus easily heats the cover cap 240. As a result, the ink in the head chip Hc is easily heated by heat transfer from the cover cap 240 to the head chip Hc.

[0118] The thermally conductive resin involved in this embodiment is characterized in that at least one of the thermal conductivity in the Z-axis direction and the thermal conductivity 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 further preferably 20 W / m·K or more.

[0119] The thermal conductivity of the present embodiment can be measured by a method in accordance with JIS-A-1412. As a specific measuring device, for example, a thermal property measuring device TPA-501 (manufactured by Kyoto Electronics Co., Ltd.) using a hot plate method can be cited. Alternatively, the thermal conductivity can be measured using a flash method.

[0120] Furthermore, as the thermally conductive resin, an electrically conductive resin material is preferable.

[0121] In contrast, the second flow channel unit 220 is formed of a resin that does not contain a thermally conductive filler. Here, in the present embodiment, "does not contain a thermally conductive filler" means that it includes a case where a thermally conductive filler is not contained at all, and also includes a case where a thermally conductive filler is contained when the thermal conductivity is less than 1.0 W / m·K. That is, in the present embodiment, if the thermal conductivity is less than 1.0 W / m·K, it is considered to contain no thermally conductive filler. In this way, by using a resin material that does not contain a thermally conductive filler as the second flow channel unit 220 that defines the flow channel, it is possible to suppress the thermally conductive filler from peeling off from the second flow channel unit 220 and mixing into the ink, and it is possible to suppress the occurrence of deviations in the ejection state of the ink droplets, thereby enabling stable ejection.

[0122] In addition, the first flow channel unit 200 is made of a material that does not contain a thermally conductive filler, similarly to the second flow channel unit 220 .

[0123] In this way, the first flow channel unit 200 and the second flow channel unit 220 are made of a resin material that does not contain a thermally conductive filler, thereby preventing the thermally conductive filler from falling out of the flow channel.

[0124] Other Implementations

[0125] Although one embodiment of the present invention has been described above, the basic structure of the present invention is not limited to the above-described embodiment.

[0126] For example, in the above-described first embodiment, the liquid ejecting head H is configured to include two head chips Hc. However, the present invention is not particularly limited thereto, and the number of head chips Hc retained by the liquid ejecting head H may be one or three or more.

[0127] In addition, although two heaters 260 are provided in the above-mentioned Embodiment 1, it is not particularly limited thereto, and a heater composed of a continuous substrate 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, a heater may be provided that is continuous there. In addition, in the case where 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 and continuous along the wall surface of the second recess 237.

[0128] In addition, although the retainer 230 is illustrated as having the second space 233b in the above-mentioned embodiment 1, it is not particularly limited thereto, and the second space 233b may also be filled with resin. However, in general, when the thick wall portion of a resin product is formed, it is easy to produce a depression on the surface due to shrinkage when the resin is cooled and solidified, that is, it is easy to produce a so-called "shrinkage cavity". Therefore, by providing the second space 233b in the retainer 230, it is possible to suppress the shrinkage cavity during forming, thereby manufacturing a high-precision product.

[0129] In addition, although in the above-mentioned embodiment 1, the lead wiring portion 280 is set as a part of the heater 260, it is not particularly limited to this, and the lead wiring portion 280 may not be a part of the heater 260. That is, although in the above-mentioned embodiment 1, the first substrate 271 of the main surface 270 and the second substrate 281 of the lead wiring portion 280 are integrally formed by bending the same substrate, it is not particularly limited to this, and it may also be a structure in which the main surface and the lead wiring portion, which are separated, are electrically connected and integrated. In other words, the heater may also be a structure consisting only of the main surface and the lead wiring portion does not constitute a part of the heater. The electrical connection between the main surface and the lead wiring portion may be an electrical connection using soldering or a conductive adhesive (ACP), etc., or it may be an electrical connection via a connector.

[0130] Furthermore, although the holder 230 is made of thermally conductive resin in the above-mentioned first embodiment, the present invention is not particularly limited thereto, and the holder 230 may be made of metal or ceramic having high thermal conductivity.

[0131] Notes

[0132] According to the above-exemplified embodiment, for example, the following configurations can be understood.

[0133] The liquid jet head of the preferred method 1 comprises: a nozzle, which ejects liquid; a planar heater, which is used to heat the liquid supplied to the nozzle, the heater having a main surface, the main surface including a temperature detection element, an insulating first substrate, a resistance wire and a relay wiring, the first substrate including a first surface and a second surface opposite to the first surface, the resistance wire is arranged on the first surface and heats the heating object as a part of the liquid jet head, the relay wiring is electrically connected to the temperature detection element and arranged on the second surface, and the resistance wire and the relay wiring overlap when viewed in the thickness direction of the main surface. Thus, by arranging the resistance wire and the relay wiring on different surfaces, the heater can be miniaturized compared to the case where they are arranged on the same surface. In addition, by arranging the resistance wire and the relay wiring at a position where they overlap when viewed in the thickness direction, the heater can be further miniaturized.

[0134] In the embodiment 2 as a specific example of the embodiment 1, the temperature detection element does not overlap with the resistance wire when viewed along the thickness direction. Thus, the temperature detection element is arranged at a position that does not overlap with the resistance wire when viewed along the Z-axis direction, so that when the temperature of the resistance wire rises instantaneously, it will not be detected by the temperature detection element, but the temperature detection element detects the temperature of the heat transfer object, thereby the temperature detection element can measure the temperature of the heat transfer object more accurately.

[0135] In mode 3 as a specific example of mode 1, there is a lead wiring section, the lead wiring section includes a first lead wiring and a second lead wiring, the first lead wiring is electrically connected to the resistance wire and extends in a direction intersecting the first substrate, the second lead wiring is electrically connected to the relay wiring and extends in a direction intersecting the first substrate, and when viewed along the thickness direction, the resistance wire is arranged between the connection between the main surface and the lead wiring section and the temperature detection element. Thus, even in a structure where the resistance wire is arranged between the connection section and the temperature detection element, the resistance wire and the relay wiring can be arranged so that the resistance wire and the relay wiring overlap when viewed along the thickness direction to avoid enlarging the main surface.

[0136] In mode 4 as a specific example of mode 3, the lead wiring portion is a portion of the heater bent from the main surface portion and includes an insulating second substrate continuous with the first substrate, the second substrate includes a third surface continuous with the first surface and a fourth surface continuous with the second surface, and the second lead wiring includes a first portion provided on the third surface together with the first lead wiring and a second portion provided on the fourth surface and electrically connected to the first portion via a through hole penetrating the second substrate. Thus, in a structure in which the second lead wiring and the resistance wire are led to the same fourth surface, by leading a portion of the second lead wiring to the fourth surface via a through hole provided on the second substrate, it is not necessary to lead the resistance wire to the fourth surface via the through hole, so that a larger current can flow through the resistance wire and efficiently heat the resistance wire.

[0137] In mode 5 as a specific example of mode 3, the temperature detection element is arranged closer to the nozzle than the connecting portion when viewed along the thickness direction. Thus, the temperature on the nozzle side can be detected by arranging the temperature detection element near the nozzle. In addition, although the heater is relatively large-scaled by arranging the connecting portion at a position far from the nozzle, the resistance wire and the relay wiring are wired on different surfaces, thereby eliminating the need for space for wiring the resistance wire and the relay wiring on the same surface, and thus the large-scale heater can be suppressed.

[0138] In mode 6 as a specific example of mode 1, the temperature detection element is arranged outside the resistance wire when viewed along the thickness direction. Therefore, even if the temperature detection element is arranged outside the resistance wire in order to detect the temperature of the head chip with high accuracy using the temperature detection element and the temperature detection element is arranged near the head chip of the holder, the main surface can be prevented from being enlarged by arranging it so that the resistance wire overlaps with the relay wiring when viewed along the thickness direction.

[0139] In mode 7 as a specific example of mode 1, the main surface portion is fixed to the heating object on a surface facing the same direction as the direction facing the first surface. Thus, by fixing the surface facing the first surface provided with the resistance wire to the heat transfer object, the heat transfer object can be efficiently heated by the resistance wire.

[0140] A liquid ejecting apparatus according to an eighth aspect as a preferred embodiment includes: the liquid ejecting head according to the first aspect; and a liquid storage portion that stores the liquid supplied to the liquid ejecting head.

[0141] Thus, the liquid in the liquid ejecting head can be heated by the heater and the heater can be miniaturized, thereby miniaturizing the liquid ejecting head and the liquid ejecting apparatus.

[0142] Explanation of symbols

[0143] H…liquid ejection head; Hc…head chip; S…medium; 1…liquid ejection device; 3…liquid storage portion; 4…control unit; 5…conveying mechanism; 6…moving mechanism; 7…holding body; 8…conveying belt; 10…channel forming substrate; 12…pressure chamber; 15…connecting plate; 19…supply connecting channel; 20…nozzle plate; 21…nozzle; 30…protective substrate; 40…housing member; 45…plastic substrate; 46…sealing film; 47…fixed substrate; 49…plastic portion; 50…vibrating plate; 51…elastic film; 52…insulating film; 60…first electrode; 70…piezoelectric layer; 80…second electrode; 91…independent lead wire Electrode; 100…manifold; 110…first flexible substrate; 111…driving signal selection circuit; 200…first flow channel unit; 201…first flow channel component; 202…second flow channel component; 203…third flow channel component; 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 channel unit; 221…fourth flow channel component; 222…fifth flow channel component; 223…second connection portion; 224…third connection portion; 225…first wiring insertion hole; 230…holder; 231…first recess ; 232…peripheral wall portion; 232a…a portion of the peripheral wall portion; 232b…rib portion; 233…storage space; 233a…first space; 233b…second space; 234…partition wall portion; 235…second connection portion insertion hole; 236…second wiring insertion hole; 237…second recessed portion; 238…opening portion for external wiring; 240…cover; 241…exposed opening portion; 250…sealing member; 251…flow channel connecting passage; 260…heater; 261…connection portion; 262…cover layer; 263…double-sided tape; 270…main surface portion; 271…first substrate; 271a…first surface; 271b…second surface ; 272…resistance wire; 273…temperature detection element; 274…relay wiring; 275…connecting hole; 280…lead-out wiring portion; 281…second substrate; 281a…third surface; 281b…fourth surface; 281c…through hole; 282…first lead-out wiring; 283…second lead-out wiring; 283a…first portion; 283b…second portion; 300…piezoelectric actuator; 310…active portion; 401…first flow channel; 402…second flow channel; 402a…first liquid storage portion; 403…third flow channel; 403a…second liquid storage portion; 404…fourth flow channel; 405…fifth flow channel; F…filter.

Claims

1. A liquid ejecting head, characterized in that: have: a nozzle, which ejects the liquid; a planar heater for heating the liquid supplied to the nozzle, The heater has a main surface, the main surface includes a temperature detection element, an insulating first substrate, a resistance wire and a relay wiring, the first substrate includes a first surface and a second surface opposite to the first surface, the resistance wire is arranged on the first surface and heats a heating object as a part of the liquid ejecting head, and the relay wiring is electrically connected to the temperature detection element and arranged on the second surface. The resistance wire and the relay wiring overlap each other when viewed in the thickness direction of the main surface portion.

2. The liquid ejecting head according to claim 1, wherein: The temperature detection element does not overlap with the resistance wire when viewed along the thickness direction.

3. The liquid ejecting head according to claim 1, wherein: A lead wiring portion is provided, wherein the lead wiring portion includes a first lead wiring and a second lead wiring, wherein the first lead wiring is electrically connected to the resistance wire and extends in a direction intersecting the first substrate, and the second lead wiring is electrically connected to the relay wiring and extends in a direction intersecting the first substrate, The resistance wire is arranged between the temperature detection element and a connection portion between the main surface portion and the lead wiring portion when viewed in the thickness direction.

4. The liquid ejecting head according to claim 3, wherein: The lead wiring portion is a portion of the heater bent from the main surface portion and includes an insulating second substrate continuous with the first substrate. The second substrate comprises a third surface continuous with the first surface and a fourth surface continuous with the second surface, The second lead wiring includes a first portion provided on the third surface together with the first lead wiring, and a second portion provided on the fourth surface and electrically connected to the first portion via a through hole penetrating the second base material.

5. The liquid ejecting head according to claim 3, wherein: The temperature detection element is arranged closer to the nozzle than the connecting portion when viewed in the thickness direction.

6. The liquid ejecting head according to claim 1, wherein: The temperature detection element is arranged outside the resistance wire when viewed along the thickness direction.

7. The liquid ejecting head according to claim 1, wherein: The main surface portion is fixed to the heating target on a surface facing the same direction as the direction facing the first surface.

8. A liquid injection device, characterized in that: have: The liquid ejecting head according to claim 1; The liquid storage portion stores the liquid supplied to the liquid ejecting head.

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