LIQUID EJECT HEAD AND LIQUID EJECT APPARATUS

Abstract

To efficiently heat a head chip by a heater.SOLUTION: A liquid jetting head supported by a support body includes: a first head chip for jetting a liquid; a holder including a holding part for holding the first head chip and a flange part making contact with the support body in a position separated from the holding part; and a heater for heating the holding part. In the liquid jetting head, the holding part has a heat receiving part for receiving heat from the heater, and the shortest route of the heat transmitted through the holder from the heat receiving part to the flange part is bent or curved at two or more parts.SELECTED DRAWING: Figure 11

Description

[Technical field]

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

[0002] A liquid ejection apparatus, such as an inkjet printer, is generally provided with a liquid ejection head that ejects liquid such as ink in the form of droplets. The liquid ejection head is supported by a support, such as a head unit described in Patent Document 1.

[0003] The head unit described in Patent Document 1 has a plurality of drive units each having a nozzle for ejecting ink, and a holder that holds the plurality of drive units, which are made of a conductive material such as metal for the purpose of grounding.

[0004] Incidentally, the liquid jet head may be provided with a heater for heating the liquid, as in the ink jet recording head described in Patent Document 2, for example. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-185739 A [Patent Document 1] JP 2010-214879 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a configuration in which the heater of Patent Document 2 is applied to the head unit described in Patent Document 1, heat from the heater is easily dissipated to the support via the holder, resulting in the problem that the heater cannot efficiently heat the drive unit. [Means for solving the problem]

[0007] In order to solve the above problems, a liquid ejection head according to a preferred embodiment of the present invention is a liquid ejection head supported on a support, and comprises a holder having a first head chip that ejects liquid, a holding portion that holds the first head chip, and a flange portion that contacts the support at a position away from the holding portion, and a heater that heats the holding portion, wherein the holding portion has a heat receiving portion that receives heat from the heater, and the shortest path for heat to be transmitted through the holder from the heat receiving portion to the flange portion is bent or curved in two or more places.

[0008] Another preferred aspect of the present invention provides a liquid jet head supported by a support, the liquid jet head comprising: a head chip having a nozzle surface on which nozzles are provided for jetting liquid in a jet direction; a holding portion for holding the head chip; a flange portion contacting the support at a position away from the holding portion; an outer wall portion connected to the flange portion and surrounding the holding portion when viewed in the jet direction; and a connection portion connecting the holding portion and the outer wall portion, the holder in which the holding portion protrudes from the connection portion in a direction opposite to the jet direction and the outer wall portion extends from the connection portion toward the flange portion in a direction opposite to the jet direction; and a heater for heating the holding portion.

[0009] A liquid ejection apparatus according to a preferred aspect of the present invention includes: A support body that supports the liquid ejection head. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of a liquid ejecting apparatus according to a first embodiment. [Diagram 2] 1 is a perspective view of a liquid jet head and a support according to a first embodiment. [Diagram 3] 1 is an exploded perspective view of a liquid jet head according to a first embodiment. FIG. [Figure 4] 3 is a cross-sectional view taken along line AA in FIG. 2. [Diagram 5] FIG. 3 is a cross-sectional view taken along line BB in FIG. [Figure 6] FIG. 2 is a cross-sectional view showing an example of a head chip. [Figure 7] FIG. 4 is a bottom view of the holder in the first embodiment. [Figure 8] FIG. 2 is a top view of the holder in the first embodiment. [Figure 9] FIG. 2 is a diagram for explaining the shape of a holding portion of the holder in the first embodiment. [Figure 10] FIG. 2 is a diagram for explaining the shapes of a heater and a heat transfer member in the first embodiment. [Figure 11] FIG. 4 is a diagram for explaining a heat transfer path from a heater in the first embodiment. [Figure 12] FIG. 11 is an exploded perspective view of a liquid jet head according to a second embodiment. [Figure 13] FIG. 11 is a diagram for explaining a heat transfer path from a heater in a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Note that the dimensions and scale of each part in the drawings may differ from the actual dimensions and some parts are shown diagrammatically to facilitate understanding. Furthermore, the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited thereto.

[0012] For convenience, the following description will be made using the mutually intersecting X-axis, Y-axis, and Z-axis as appropriate. In the following description, one direction along the X-axis is the X1 direction, and the direction opposite to the X1 direction is the X2 direction. Similarly, the opposite directions along the Y-axis are the Y1 direction and the Y2 direction. Also, the opposite directions along the Z-axis are the Z1 direction and the Z2 direction. Also, viewing in the Z-axis direction may simply be referred to as "planar view." Note that the Y direction or the Y2 direction is an example of the "first direction." The X1 direction or the X2 direction is an example of the "second direction."

[0013] Typically, the Z axis is a vertical axis, and the Z2 direction corresponds to the downward direction in the vertical direction. However, the Z axis does not have to be a vertical axis. Also, the X axis, the Y axis, and the Z axis are typically perpendicular to each other, but are not limited to this, and may intersect at an angle within a range of 80° to 100°, for example.

[0014] 1. First embodiment 1-1. Schematic configuration of the liquid ejection device 1 is a schematic diagram showing an example of the configuration of a liquid ejection device 100 according to a first embodiment. The liquid ejection device 100 is an inkjet printing device that ejects ink, which is an example of a "liquid," as droplets onto a medium M. The medium M is typically printing paper. Note that the medium M is not limited to printing paper, and may be a printing target made of any material, such as a resin film or fabric.

[0015] * Corresponding to claim 17 of J0207333 and claim 14 of J0207437 As shown in FIG. 1, the liquid ejection device 100 includes a liquid storage section 10, a control unit 20, a transport mechanism 30, a moving mechanism 40, and a liquid ejection head 50. The liquid ejection head 50 includes a liquid storage section 10 and a control unit 20.

[0016] The liquid storage unit 10 is a container that stores ink. Specific examples of the liquid storage unit 10 include a cartridge that is detachable from the liquid ejection device 100, a bag-shaped ink pack made of a flexible film, and a container such as an ink tank that can be refilled with ink.

[0017] Although not shown, the liquid storage section 10 has a plurality of containers for storing different types of ink. The inks stored in the plurality of containers are not particularly limited, but include, for example, cyan ink, magenta ink, yellow ink, black ink, clear ink, white ink, and treatment liquid, and a combination of two or more of these is used. The composition of the ink is not particularly limited, and may be, for example, a water-based ink in which a coloring material such as a dye or pigment is dissolved in a water-based solvent, a solvent-based ink in which a coloring material is dissolved in an organic solvent, or an ultraviolet-curable ink.

[0018] In this embodiment, a configuration is exemplified in which four different types of ink are used, the four types of ink being inks of different colors, such as cyan ink, magenta ink, yellow ink, and black ink.

[0019] The control unit 20 controls the operation of each element of the liquid ejection device 100. For example, the control unit 20 includes a processing circuit such as a central processing unit (CPU) or a field programmable gate array (FPGA), and a storage circuit such as a semiconductor memory. The control unit 20 outputs a drive signal D and a control signal S to the liquid ejection head 50. The drive signal D is a signal including a drive pulse that drives a drive element of the liquid ejection head 50. The control signal S is a signal that specifies whether or not to supply the drive signal D to the drive element.

[0020] *Description corresponding to claim 13 of J0207369 The transport mechanism 30 transports the medium M in a transport direction DM, which is the Y1 direction, under the control of the control unit 20. The movement mechanism 40 reciprocates the liquid ejection head 50 in the X1 direction and the X2 direction under the control of the control unit 20. In the example shown in FIG. 1, the movement mechanism 40 has a substantially box-shaped support 41, called a carriage, that houses the liquid ejection head 50, and a transport belt 42 to which the support 41 is fixed. Note that, in addition to the liquid ejection head 50, the support 41 may also be equipped with the above-mentioned liquid storage unit 10.

[0021] The liquid jet head 50 has a plurality of head chips 54 as described below, and under the control of the control unit 20, ink supplied from the liquid storage section 10 is jetted from each of a plurality of nozzles of each head chip 54 in the Z2 direction, which is the jetting direction, towards the medium M. This jetting is performed in parallel with the transport of the medium M by the transport mechanism 30 and the reciprocating movement of the liquid jet head 50 by the movement mechanism 40, so that a predetermined image is formed on the surface of the medium M with ink.

[0022] The liquid storage unit 10 may be connected to the liquid jet head 50 via a circulation mechanism. The circulation mechanism is a mechanism that supplies ink to the liquid jet head 50 and collects ink discharged from the liquid jet head 50 for resupply to the liquid jet head 50. The operation of the circulation mechanism can suppress an increase in the viscosity of the ink and reduce the retention of air bubbles in the ink.

[0023] 1-2. Liquid jet head installation status FIG. 2 is a perspective view of the liquid jet head 50 and the support 41 according to the first embodiment. As shown in FIG. 2, the liquid jet head 50 is supported by the support 41. The support 41 is a member that supports the liquid jet head 50, and as described above, in this embodiment, it is a substantially box-shaped carriage. The constituent material of the support 41 is not particularly limited, but it is preferable to use a metal material such as stainless steel, aluminum, titanium, or a magnesium alloy. When the support 41 is made of a metal material, it is easy to increase the rigidity of the support 41, so that the liquid jet head 50 can be stably supported by the support 41. In addition, in this case, since the support 41 has conductivity, a reference potential can be supplied to the liquid jet head 50 via the support 41.

[0024] Here, the support 41 is provided with an opening 41a and a plurality of screw holes 41b. In this embodiment, the support 41 is substantially box-shaped with a plate-shaped bottom, and, for example, the opening 41a and the plurality of screw holes 41b are provided in the bottom. The liquid jet head 50 is inserted into the opening 41a and fixed to the support 41 by screws using the plurality of screw holes 41b. As described above, the liquid jet head 50 is attached to the support 41.

[0025] 2, the number of liquid ejection heads 50 attached to the support 41 is one. The number of liquid ejection heads 50 attached to the support 41 may be two or more. In this case, the support 41 is appropriately provided with openings 41a having a number or shape corresponding to the number of liquid ejection heads 50.

[0026] 1. First embodiment 1-1. Schematic configuration of the liquid ejection device 1 is a schematic diagram showing an example of the configuration of a liquid ejection device 100 according to a first embodiment. The liquid ejection device 100 is an inkjet printing device that ejects ink, which is an example of a "liquid," as droplets onto a medium M. The medium M is typically printing paper. Note that the medium M is not limited to printing paper, and may be a printing target made of any material, such as a resin film or fabric.

[0027] As shown in FIG. 1, the liquid ejection device 100 includes a liquid storage section 10, a control unit 20, a transport mechanism 30, a moving mechanism 40, and a liquid ejection head 50. The liquid ejection head 50 includes a liquid storage section 10 and a control unit 20.

[0028] The liquid storage unit 10 is a container that stores ink. Specific examples of the liquid storage unit 10 include a cartridge that is detachable from the liquid ejection device 100, a bag-shaped ink pack made of a flexible film, and a container such as an ink tank that can be refilled with ink.

[0029] Although not shown, the liquid storage section 10 has a plurality of containers for storing different types of ink. The inks stored in the plurality of containers are not particularly limited, but include, for example, cyan ink, magenta ink, yellow ink, black ink, clear ink, white ink, and treatment liquid, and a combination of two or more of these is used. The composition of the ink is not particularly limited, and may be, for example, a water-based ink in which a coloring material such as a dye or pigment is dissolved in a water-based solvent, a solvent-based ink in which a coloring material is dissolved in an organic solvent, or an ultraviolet-curable ink.

[0030] In this embodiment, a configuration is exemplified in which four different types of ink are used, the four types of ink being inks of different colors, such as cyan ink, magenta ink, yellow ink, and black ink.

[0031] The control unit 20 controls the operation of each element of the liquid ejection device 100. For example, the control unit 20 includes a processing circuit such as a central processing unit (CPU) or a field programmable gate array (FPGA), and a storage circuit such as a semiconductor memory. The control unit 20 outputs a drive signal D and a control signal S to the liquid ejection head 50. The drive signal D is a signal including a drive pulse that drives a drive element of the liquid ejection head 50. The control signal S is a signal that specifies whether or not to supply the drive signal D to the drive element.

[0032] The transport mechanism 30 transports the medium M in a transport direction DM, which is the Y1 direction, under the control of the control unit 20. The movement mechanism 40 reciprocates the liquid ejection head 50 in the X1 direction and the X2 direction under the control of the control unit 20. In the example shown in FIG. 1, the movement mechanism 40 has a substantially box-shaped support 41, called a carriage, that houses the liquid ejection head 50, and a transport belt 42 to which the support 41 is fixed. Note that, in addition to the liquid ejection head 50, the support 41 may also be equipped with the above-mentioned liquid storage unit 10.

[0033] The liquid jet head 50 has a plurality of head chips 54 as described below, and under the control of the control unit 20, ink supplied from the liquid storage section 10 is jetted from each of a plurality of nozzles of each head chip 54 in the Z2 direction, which is the jetting direction, towards the medium M. This jetting is performed in parallel with the transport of the medium M by the transport mechanism 30 and the reciprocating movement of the liquid jet head 50 by the movement mechanism 40, so that a predetermined image is formed on the surface of the medium M with ink.

[0034] The liquid storage unit 10 may be connected to the liquid jet head 50 via a circulation mechanism. The circulation mechanism is a mechanism that supplies ink to the liquid jet head 50 and collects ink discharged from the liquid jet head 50 for resupply to the liquid jet head 50. The operation of the circulation mechanism can suppress an increase in the viscosity of the ink and reduce the retention of air bubbles in the ink.

[0035] 1-2. Liquid jet head installation status FIG. 2 is a perspective view of the liquid jet head 50 and the support 41 according to the first embodiment. As shown in FIG. 2, the liquid jet head 50 is supported by the support 41. The support 41 is a member that supports the liquid jet head 50, and as described above, in this embodiment, it is a substantially box-shaped carriage. The constituent material of the support 41 is not particularly limited, but it is preferable to use a metal material such as stainless steel, aluminum, titanium, or a magnesium alloy. When the support 41 is made of a metal material, it is easy to increase the rigidity of the support 41, so that the liquid jet head 50 can be stably supported by the support 41. In addition, in this case, since the support 41 has conductivity, a reference potential can be supplied to the liquid jet head 50 via the support 41.

[0036] Here, the support 41 is provided with an opening 41a and a plurality of screw holes 41b. In this embodiment, the support 41 is substantially box-shaped with a plate-shaped bottom, and, for example, the opening 41a and the plurality of screw holes 41b are provided in the bottom. The liquid jet head 50 is inserted into the opening 41a and fixed to the support 41 by screws using the plurality of screw holes 41b. As described above, the liquid jet head 50 is attached to the support 41.

[0037] 2, the number of liquid ejection heads 50 attached to the support 41 is one. The number of liquid ejection heads 50 attached to the support 41 may be two or more. In this case, the support 41 is appropriately provided with openings 41a having a number or shape corresponding to the number of liquid ejection heads 50.

[0038] 1-3. Configuration of liquid ejection head Fig. 3 is an exploded perspective view of the liquid jet head 50 according to the first embodiment. Fig. 4 is a cross-sectional view taken along line AA in Fig. 2. Fig. 5 is a cross-sectional view taken along line BB in Fig. 2. Note that, for convenience, each part of the liquid jet head 50 is shown in a simplified manner as appropriate in Figs. 3 to 5. For example, as shown in Fig. 11 described later, a gap of distance d2 is provided between the outer wall portion 5b and the flow path structure 51, but in Figs. 4 and 5, the gap is omitted for convenience of drawing.

[0039] 3, the liquid jet head 50 includes a flow path structure 51, a substrate unit 52, a holder 53, four head chips 54_1 to 54_4, a fixed plate 55, a heater 56, a heat transfer member 57, and a cover 58. These are arranged in the Z2 direction in the following order: cover 58, substrate unit 52, flow path structure 51, heat transfer member 57, heater 56, holder 53, four head chips 54, and fixed plate 55. Each part of the liquid jet head 50 will be described below in order.

[0040] Heat transfer member 57 is an example of a "second heat transfer member." Moreover, each of head chips 54_1 to 54_4 is head chip 54 shown in FIG. 1. Here, head chip 54_1 is an example of a "first head chip." Head chip 54_2 is an example of a "second head chip." Head chip 54_3 is an example of a "third head chip." Head chip 54_4 is an example of a "fourth head chip." Hereinafter, when head chips 54_1 to 54_4 are not to be distinguished from one another, each of these chips will be referred to as head chip 54.

[0041] The flow path structure 51 is a structure in which a flow path is provided therein for supplying the ink stored in the above-mentioned liquid storage portion 10 to four head chips 54. The flow path structure 51 has a flow path member 51a and eight connection pipes 51b.

[0042] Although not shown, the flow path member 51a is provided with four supply flow paths provided for each of the four types of ink, and four discharge flow paths provided for each of the four types of ink. Each of the four supply flow paths has one inlet for receiving the supply of ink and two outlets for discharging the ink. Each of the four discharge flow paths has two inlets for receiving the supply of ink and one outlet for discharging the ink. The inlets of each supply flow path and the outlets of each discharge flow path are provided on a surface of the flow path member 51a facing the Z1 direction. In contrast, the outlets of each supply flow path and the inlets of each discharge flow path are provided on a surface of the flow path member 51a facing the Z2 direction.

[0043] Furthermore, the flow path member 51a is provided with a plurality of wiring holes 51c. Each of the plurality of wiring holes 51c is a hole through which a wiring board 54i (described later) of the head chip 54 is passed toward the substrate unit 52. The side surface of the flow path member 51a is provided with two cutout portions in the circumferential direction. In the space formed by the cutout portions, for example, components such as wiring (not shown) that connect the heater 56 and the substrate unit 52 are disposed. Furthermore, the flow path member 51a is provided with holes (not shown), and the flow path member 51a is fixed to the holder 53 by screwing using the holes.

[0044] Although not shown, the flow path member 51a is composed of a laminate in which a plurality of substrates are laminated in a direction along the Z axis. Each of the plurality of substrates is appropriately provided with grooves and holes for the above-mentioned supply flow path and discharge flow path. The plurality of substrates are joined to each other, for example, by adhesive, brazing, welding, screwing, or the like. Note that, if necessary, a sheet-like seal member made of a rubber material or the like may be appropriately disposed between the plurality of substrates. In addition, the number or thickness of the substrates constituting the flow path member 51a is determined according to the shape and other aspects of the supply flow path and the discharge flow path, and is not particularly limited and is arbitrary.

[0045] The constituent material of each of the plurality of substrates is preferably a material with good thermal conductivity, for example, a metal material such as stainless steel, titanium, or magnesium alloy, or a ceramic material such as silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, or yttria, each of which has a thermal conductivity of 10.0 W / m·K or more at room temperature (20° C.). By forming flow path member 51a using such a metal material or ceramic material, the ink in flow path member 51a can be efficiently heated by heat from heater 56.

[0046] Each of the eight connecting pipes 51b is a pipe protruding from the surface of the flow path member 51a facing the Z1 direction. The eight connecting pipes 51b correspond to the four supply flow paths and the four discharge flow paths described above, and are connected to the inlets of the corresponding supply flow paths or the discharge ports of the corresponding discharge flow paths. The constituent material of each connecting pipe 51b is not particularly limited, but it is preferable to use, for example, metal materials such as stainless steel, titanium, and magnesium alloy, or ceramic materials such as silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, and yttria.

[0047] Of the eight connection tubes 51b, the four connection tubes 51b corresponding to the four supply flow paths are connected to the liquid storage unit 10 so as to receive different types of ink. On the other hand, of the eight connection tubes 51b, the four connection tubes 51b corresponding to the four discharge flow paths are used by connecting them to a discharge container for discharging ink at a predetermined time such as when the liquid ejection head 50 is initially filled with ink or a sub-tank that is disposed between the liquid storage unit 10 and the liquid ejection head 50 and can hold liquid. During normal times such as printing, the four connection tubes 51b corresponding to the four discharge flow paths are blocked by a seal such as a cap. When the liquid storage unit 10 is connected to the liquid ejection head 50 via a circulation mechanism, the four connection tubes 51b corresponding to the four discharge flow paths are normally connected to a flow path for recovering ink in the circulation mechanism.

[0048] The board unit 52 is an assembly having mounted components for electrically connecting the liquid ejection head 50 to the control unit 20. The board unit 52 has a circuit board 52a, a connector 52b, and a support plate 52c.

[0049] The circuit board 52a is a printed wiring board such as a rigid wiring board having wiring for electrically connecting each head chip 54 and the connector 52b. The circuit board 52a is disposed on the flow path structure 51 via a support plate 52c, and the connector 52b is disposed on the surface of the circuit board 52a facing the Z1 direction.

[0050] The connector 52b is a connection part for electrically connecting the liquid ejection head 50 and the control unit 20. The support plate 52c is a plate-shaped member for attaching the circuit board 52a to the flow path structure 51. The circuit board 52a is placed on one surface of the support plate 52c, and the circuit board 52a is fixed to the support plate 52c by screwing or the like. The other surface of the support plate 52c is in contact with the flow path structure 51, and in this state, the support plate 52c is fixed to the flow path structure 51 by screwing or the like.

[0051] Here, the support plate 52c not only has the function of supporting the circuit board 52a as described above, but also has the function of ensuring electrical insulation between the circuit board 52a and the flow path structure 51, and of insulating between the heater 56 and the circuit board 52a. From the viewpoint of suitably exerting these functions, the constituent material of the support plate 52c is preferably a material having excellent insulating and heat insulating properties, and specifically, for example, a resin material such as a modified polyphenylene ether resin such as Zylon, a polyphenylene sulfide resin, or a polypropylene resin. Zylon is a registered trademark. The constituent material of the support plate 52c may include a fiber base material such as glass fiber, or a filler such as alumina particles, in addition to the resin material.

[0052] The holder 53 is a structure that houses and supports the four head chips 54. It is preferable to use a material with good thermal conductivity as a constituent material of the holder 53, for example, a metal material such as stainless steel, titanium, or magnesium alloy, or a ceramic material such as silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, or yttria, which has a thermal conductivity of 10.0 W / m·K or more at room temperature (20° C.). By forming the holder 53 using such a metal material or ceramic material, the heat from the heater 56 can be efficiently transferred to each head chip 54 via the holder 53.

[0053] The holder 53 is substantially tray-shaped and has a recess 53a, a plurality of ink holes 53b, a plurality of wiring holes 53c, a plurality of recesses 53d, a plurality of screw holes 53i, and a plurality of screw holes 53k. The recess 53a opens toward the Z1 direction and is a space in which the laminate of the flow path member 51a, the heater 56, and the heat transfer member 57 is disposed. Each of the ink holes 53b is a flow path that distributes ink between the head chip 54 and the flow path structure 51. Each of the wiring holes 53c is a hole through which the wiring board 54i of the head chip 54 is passed toward the board unit 52. Each of the recesses 53d is open toward the Z2 direction and is a space in which the head chip 54 is disposed. The plurality of screw holes 53i are screw holes for screwing the holder 53 to the support 41. The plurality of screw holes 53k are screw holes for screwing the cover 58 to the holder 53. The holder 53 will be described in detail later with reference to FIGS.

[0054] Each head chip 54 ejects ink. Each head chip 54 has a plurality of nozzles that eject a first ink and a plurality of nozzles that eject a second ink different from the first ink. Here, the first ink and the second ink are two of the four types of ink described above. For example, two of the four types of ink are used as the first ink and the second ink in each of the head chips 54_1 and 54_2. The remaining two of the four types of ink are used in each of the head chips 54_3 and 54_4. A wiring board 54i is provided in each head chip 54. Note that the configuration of each head chip 54 is illustrated in a simplified manner in FIG. 3. The configuration of the head chip 54 will be described in detail with reference to FIG. 6 described later.

[0055] Fixed plate 55 is a plate-like member to which four head chips 54 and holder 53 are fixed. Specifically, fixed plate 55 is disposed in a state in which four head chips 54 are sandwiched between fixed plate 55 and holder 53, and each head chip 54 and holder 53 are fixed by an adhesive or the like.

[0056] The fixed plate 55 is provided with a plurality of openings 55a that expose the nozzle surfaces FN of the four head chips 54. In the example shown in FIG. 3, the plurality of openings 55a are provided for each head chip 54. The fixed plate 55 is made of a metal material such as stainless steel, titanium, or magnesium alloy, and has a function of transferring heat from the holder 53 to each head chip 54. The fixed plate 55 is conductive. Therefore, the fixed plate 55 is grounded via the holder 53 and the support 41, and also functions as an electrostatic shield to prevent the influence of static electricity from the medium M. The fixed plate 55 may be formed by stacking plate-shaped members made of a plurality of metal materials.

[0057] The outer shape of the fixing plate 55 described above is rectangular or approximately rectangular in plan view. Here, the term "approximately rectangular" is a concept including a shape that can be said to be substantially rectangular and a shape similar to a rectangle. A shape that can be said to be substantially rectangular is, for example, a shape obtained by chamfering the four corners of a rectangle with C-chamfering or R-chamfering. A shape similar to a rectangle is, for example, a shape such as an octagon that includes four sides along the rectangle and four sides that are shorter than each of the four sides. The opening 55a may be shared by two or more head chips 54. However, when the opening 55a is provided individually for each head chip 54, it is easy to increase the contact area between the fixing plate 55 and each head chip 54, so that heat can be efficiently transferred from the holder 53 to each head chip 54.

[0058] The heater 56 is a planar heater disposed between the flow path structure 51 and the holder 53. The heater 56 is, for example, a film heater having an insulating film and a thin-film heating resistor. The film is made of a resin material such as polyimide or PET (polyethylene terephthalate). The heating resistor is patterned on the film and made of a metal material such as stainless steel, copper, or nickel alloy. The heater 56 may also be a planar heater such as a silicone rubber heater having a heating element sandwiched between glass fiber-reinforced silicone rubber or a ceramic heater.

[0059] The heater 56 is provided with a plurality of holes 56a and a plurality of holes 56b. Each of the plurality of holes 56a is a hole through which the wiring board 54i of the head chip 54 and the flow path pipe 53l formed in the holder 53 pass. The ink hole 53b formed inside the flow path pipe 53l is a part of a flow path that distributes ink between the head chip 54 and the flow path structure 51. For example, the flow path pipe 53l protrudes in the Z1 direction from an upper surface (a first surface F1 described later) of the holder 53 facing the Z1 direction. Then, the tip of the flow path pipe 53l on the Z1 direction side is bonded to a lower surface of the flow path structure 51 facing the Z2 direction, so that the ink hole 53b is liquid-tightly sealed with the flow path inside the flow path structure 51. Each of the plurality of holes 56b is a hole for screwing the heater 56 to the holder 53. The shape of the heater 56 in a plan view will be described in detail with reference to FIG. 10 described later.

[0060] The heat transfer member 57 is a plate-like member having thermal conductivity and disposed between the flow path structure 51 and the heater 56. The heat transfer member 57 has a function of transferring heat in both the thickness direction and the surface direction. Due to this function, heat from the heater 56 is efficiently transferred to the flow path structure 51 via the heat transfer member 57. Here, due to the heat transfer in the surface direction of the heat transfer member 57, uneven heating of the flow path structure 51 caused by the heat generation distribution of the heater 56 is reduced.

[0061] The heat transfer member 57 is made of a thermally conductive material such as a metal material or a ceramic such as silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, and yttria. Examples of the metal material include stainless steel, aluminum, titanium, and magnesium alloy. The heat transfer member 57 is preferably made of a material having high thermal conductivity with respect to the flow path structure 51 and the holder 53. By providing such a heat transfer member 57 having high thermal conductivity, the heat from the heater 56 can be easily transferred in a direction parallel to the nozzle surface FN, so that the heat from the heater 56 can be uniformly and efficiently transferred to the flow path structure 51, which is the object to be heated, via the heat transfer member 57.

[0062] The heat transfer member 57 is provided with a plurality of holes 57a, a plurality of wiring holes 57b, and a plurality of holes 57c. Each of the plurality of holes 57a is a hole through which the above-mentioned flow path pipe 53l is inserted. Each of the plurality of wiring holes 57b is a hole through which the wiring board 54i of the head chip 54 is passed toward the board unit 52. The plurality of holes 57c are holes for screwing the heat transfer member 57 to the holder 53. In this embodiment, two of the plurality of holes 57c are used to fix the heater 56 and the heat transfer member 57 to the holder 53 by tightening them together. The planar shape of the heat transfer member 57 will be described in detail with reference to FIG. 10 described later.

[0063] The cover 58 is a box-shaped member that houses the board unit 52. The cover 58 is made of a resin material such as modified polyphenylene ether resin, polyphenylene sulfide resin, or polypropylene resin, similar to the above-mentioned support plate 52c.

[0064] Eight through holes 58a and an opening 58b are provided in the cover 58. The eight through holes 58a correspond to the eight connecting pipes 51b of the flow path structure 51, and the corresponding connecting pipes 51b are inserted into each through hole 58a. The aforementioned connector 52b is passed through the opening 58b from the inside to the outside of the cover 58.

[0065] 1-4.Head chip configuration Fig. 6 is a cross-sectional view showing an example of the head chip 54. As shown in Fig. 6, the head chip 54 has a plurality of nozzles N arranged in the direction along the Y axis. The plurality of nozzles N are divided into a first row L1 and a second row L2 arranged at intervals in the direction along the X axis. Each of the first row L1 and the second row L2 is a collection of a plurality of nozzles N arranged linearly in the direction along the Y axis.

[0066] The head chips 54 are configured to be substantially symmetrical to each other in the direction along the X-axis. However, the positions of the multiple nozzles N in the first row L1 and the multiple nozzles N in the second row L2 in the direction along the Y-axis may be the same or different. Fig. 6 illustrates a configuration in which the positions of the multiple nozzles N in the first row L1 and the multiple nozzles N in the second row L2 in the direction along the Y-axis are the same.

[0067] As shown in FIG. 6, the head chip 54 has a flow path substrate 54a, a pressure chamber substrate 54b, a nozzle plate 54c, a vibration absorber 54d, a vibration plate 54e, a plurality of piezoelectric elements 54f, a protective plate 54g, a case 54h, a wiring board 54i, and a drive circuit 54j.

[0068] The flow path substrate 54a and the pressure chamber substrate 54b are laminated in this order in the Z1 direction to form a flow path for supplying ink to the multiple nozzles N. In an area located in the Z1 direction from the laminate consisting of the flow path substrate 54a and the pressure chamber substrate 54b, a vibration plate 54e, multiple piezoelectric elements 54f, a protective plate 54g, a case 54h, a wiring substrate 54i, and a drive circuit 54j are installed. On the other hand, in an area located in the Z2 direction from the laminate, a nozzle plate 54c and a vibration absorber 54d are installed. Each element of the head chip 54 is roughly a plate-like member elongated in the Y direction, and is joined to each other by, for example, an adhesive. Each element of the head chip 54 will be described in order below.

[0069] The nozzle plate 54c is a plate-like member in which a plurality of nozzles N are provided in each of the first row L1 and the second row L2. Each of the plurality of nozzles N is a through hole that allows ink to pass through. Here, the surface of the nozzle plate 54c facing the Z2 direction is the nozzle surface FN. That is, the normal direction of the nozzle surface FN is the direction of the normal vector of the nozzle surface FN, which is the Z2 direction that is the ejection direction. The nozzle plate 54c is manufactured by processing a silicon single crystal substrate by a semiconductor manufacturing technique that uses a processing technique such as dry etching or wet etching. However, other known methods and materials may be appropriately used to manufacture the nozzle plate 54c. In addition, the cross-sectional shape of the nozzle is typically circular, but is not limited thereto, and may be non-circular, such as polygonal or elliptical.

[0070] The flow path substrate 54a is provided with a space R1, a plurality of supply flow paths Ra, and a plurality of communication flow paths Na for each of the first row L1 and the second row L2. The space R1 is an elongated opening extending in the direction along the Y axis in a plan view seen in the direction along the Z axis. Each of the supply flow paths Ra and the communication flow paths Na is a through hole formed for each nozzle N. Each supply flow path Ra communicates with the space R1.

[0071] The pressure chamber substrate 54b is a plate-like member in which a plurality of pressure chambers C called cavities are provided for each of the first row L1 and the second row L2. The plurality of pressure chambers C are arranged in a direction along the Y axis. Each pressure chamber C is formed for each nozzle N and is an elongated space extending in a direction along the X axis in a plan view. Similarly to the nozzle plate 54c described above, each of the flow path substrate 54a and the pressure chamber substrate 54b is manufactured by processing a silicon single crystal substrate by, for example, a semiconductor manufacturing technique. However, other known methods and materials may be appropriately used for manufacturing each of the flow path substrate 54a and the pressure chamber substrate 54b.

[0072] The pressure chambers C are spaces located between the flow path substrate 54a and the vibration plate 54e. A plurality of pressure chambers C are arranged in the direction along the Y axis in each of the first row L1 and the second row L2. The pressure chambers C are also connected to the communication flow path Na and the supply flow path Ra. Therefore, the pressure chambers C are connected to the nozzle N via the communication flow path Na, and are connected to the space R1 via the supply flow path Ra.

[0073] A vibration plate 54e is disposed on the surface of the pressure chamber substrate 54b facing the Z1 direction. The vibration plate 54e is a plate-shaped member that can vibrate elastically. The vibration plate 54e has, for example, a first layer and a second layer, which are laminated in this order in the Z1 direction. The first layer is, for example, an elastic film made of silicon oxide (SiO2). The elastic film is formed, for example, by thermally oxidizing one surface of a silicon single crystal substrate. The second layer is, for example, an insulating film made of zirconium oxide (ZrO2). The insulating film is formed, for example, by forming a layer of zirconium by a sputtering method and thermally oxidizing the layer. Note that the vibration plate 54e is not limited to the configuration of the laminate of the first layer and the second layer described above, and may be, for example, a single layer or three or more layers.

[0074] On the surface of the vibration plate 54e facing the Z1 direction, a plurality of piezoelectric elements 54f corresponding to the nozzles N are arranged as drive elements in each of the first row L1 and the second row L2. Each piezoelectric element 54f is a passive element that deforms when a drive signal is supplied. Each piezoelectric element 54f has an elongated shape extending in the direction along the X-axis in a plan view. The plurality of piezoelectric elements 54f are arranged in the direction along the Y-axis so as to correspond to the plurality of pressure chambers C. The piezoelectric elements 54f overlap the pressure chambers C in a plan view.

[0075] Although not shown, each piezoelectric element 54f has a first electrode, a piezoelectric layer, and a second electrode, which are laminated in this order in the Z1 direction. One of the first electrode and the second electrode is an individual electrode that is spaced apart from each other for each piezoelectric element 54f, and a drive signal is applied to the one electrode. The other of the first electrode and the second electrode is a band-shaped common electrode that extends in the direction along the Y axis so as to be continuous across the multiple piezoelectric elements 54f, and a predetermined reference potential is supplied to the other electrode. Examples of metal materials for these electrodes include metal materials such as platinum (Pt), aluminum (Al), nickel (Ni), gold (Au), and copper (Cu), and among these, one type can be used alone or two or more types can be used in combination in the form of an alloy or laminate. The piezoelectric layer is made of a piezoelectric material such as lead zirconate titanate (Pb(Zr,Ti)O3) and has a strip shape extending in the direction along the Y axis so as to be continuous across the piezoelectric elements 54f. However, the piezoelectric layer may be integral across the piezoelectric elements 54f. In this case, the piezoelectric layer is provided with through holes extending in the direction along the X axis in areas corresponding to the gaps between the adjacent pressure chambers C in a plan view. When the vibration plate 54e vibrates in conjunction with the deformation of the piezoelectric elements 54f, the pressure in the pressure chambers C fluctuates, and ink is ejected from the nozzles N. Note that a heating element for heating the ink in the pressure chambers C may be used as the driving element instead of the piezoelectric elements 54f.

[0076] The protective plate 54g is a plate-like member installed on the surface of the vibration plate 54e facing the Z1 direction, and protects the multiple piezoelectric elements 54f and reinforces the mechanical strength of the vibration plate 54e. The multiple piezoelectric elements 54f are housed between the protective plate 54g and the vibration plate 54e. The protective plate 54g is made of, for example, a resin material.

[0077] The case 54h is a case for storing ink to be supplied to the multiple pressure chambers C. The case 54h is made of, for example, a resin material. The case 54h is provided with a space R2 for each of the first row L1 and the second row L2. The space R2 is a space that communicates with the above-mentioned space R1, and functions as a reservoir R that stores ink to be supplied to the multiple pressure chambers C together with the space R1. The case 54h is provided with an inlet IO for supplying ink to each reservoir R. The ink in each reservoir R is supplied to the pressure chamber C via each supply flow path Ra.

[0078] The vibration absorber 54d is also called a compliance substrate, and is a flexible resin film that constitutes the wall surface of the reservoir R, and absorbs pressure fluctuations of the ink in the reservoir R. The vibration absorber 54d may be a flexible thin plate made of metal. The surface of the vibration absorber 54d facing the Z1 direction is bonded to the flow path substrate 54a with an adhesive or the like. On the other hand, the frame body 54k is bonded to the surface of the vibration absorber 54d facing the Z2 direction with an adhesive or the like. The frame body 54k is a frame-shaped member that follows the outer periphery of the vibration absorber 54d and contacts the above-mentioned fixed plate 55. Here, the frame body 54k is made of a metal material such as stainless steel, aluminum, titanium, and magnesium alloy. By making the frame body 54k out of a metal material in this way, heat from the heater 56 can be suitably transferred to the ink in the head chip 54 via the holder 53 and the fixed plate 55. 6, the heat transfer path H1 from the heater 56 to the head chip 54 is shown by a dashed arrow. A part of the transfer path H1 includes a vibration absorber 54d made of resin, which is a material with a relatively low thermal conductivity. However, the vibration absorber 54d is flexible and formed in a film shape, so it is thin and has very low thermal resistance. Therefore, the vibration absorber 54d does not have much effect of inhibiting the transfer of heat from the frame 54k to the flow path substrate 54a.

[0079] The wiring board 54i is mounted on the surface of the vibration plate 54e facing the Z1 direction, and is a mounting component for electrically connecting the control unit 20 and the head chip 54. The wiring board 54i is a flexible wiring board such as a COF (Chip On Film), an FPC (Flexible Printed Circuit), or an FFC (Flexible Flat Cable). A drive circuit 54j for supplying a drive voltage to each piezoelectric element 54f is mounted on the wiring board 54i of this embodiment. The drive circuit 54j is a circuit that switches whether or not to supply at least a part of the waveform included in the drive signal D as a drive pulse based on the control signal S.

[0080] 1-5.Holder configuration Fig. 7 is a bottom view of holder 53 in the first embodiment as seen in the Z1 direction. Fig. 8 is a top view of holder 53 in the first embodiment as seen in the Z2 direction. As described above, holder 53, which is substantially tray-shaped, has a bottom portion 5a, an outer wall portion 5b, and a flange portion 5c as shown in Figs. 7 and 8.

[0081] The bottom portion 5a is generally plate-shaped and extends in a direction perpendicular to the Z axis, and constitutes the bottom surface of the recess 53a. Here, the bottom portion 5a is divided into a holding portion 5a1 and a connecting portion 5a2 that is disposed around the outer periphery of the holding portion 5a1 and is thinner than the holding portion 5a1.

[0082] The holding portion 5a1 has the four recesses 53d described above and holds four head chips 54. Each head chip 54 is accommodated in a space surrounded by each recess 53d and a fixing plate 55. As shown in FIG. 7, the holding portion 5a1 is provided with two recesses 53h in addition to the four recesses 53d. Each recess 53h is a recess for so-called weight reduction, and is disposed between the four recesses 53d and has a depth similar to that of the recesses 53d. The holding portion 5a1 has a heat receiving portion 5a11 and a side wall portion 5a12.

[0083] The heat receiving portion 5a11 is in the form of a plate having a first surface F1 and a second surface F2 extending in a direction perpendicular to the Z axis, and constitutes the bottom surfaces of the recesses 53d and 53h. The first surface F1 faces the Z1 direction and is a heat receiving surface that receives heat from the heater 56. The flow path structure 51 is placed on the first surface F1 via the heater 56 and the heat transfer member 57 described above. The second surface F2 faces the Z2 direction and constitutes the bottom surfaces of the recesses 53d and 53h.

[0084] 7 and 8, the heat receiving portion 5a11 is provided with a plurality of ink holes 53b and a plurality of wiring holes 53c opening on the first surface F1 and the second surface F2, respectively. In addition to these, the first surface F1 of the heat receiving portion 5a11 is provided with a plurality of holes 53e, a plurality of holes 53f, and a plurality of screw holes 53g.

[0085] The plurality of holes 53e are holes into which protrusions (not shown) provided on the head chip 54 are inserted, thereby positioning the head chip 54 relative to the holder 53. The plurality of holes 53f are holes into which positioning pins are inserted, which are used to position the flow path structure 51, the heater 56, and the heat transfer member 57. The plurality of screw holes 53g are screw holes used to screw the heat transfer member 57. The plurality of screw holes 53g are screw holes used to screw the flow path structure 51.

[0086] The side wall portion 5a12 protrudes from the heat receiving portion 5a11 in the Z2 direction and constitutes the side surfaces of the recesses 53d and the recesses 53h. The connecting portion 5a2 is connected to the end of the side wall portion 5a12 in the Z2 direction. Here, the shape of the side wall portion 5a12 is a shape obtained by removing the shapes of the recesses 53d and the recesses 53h from the shape of the heat receiving portion 5a11 when viewed in the direction along the Z axis. That is, the side wall portion 5a12 includes, when viewed in the direction along the Z axis, a partition wall between the adjacent recesses 53d, a partition wall between the adjacent recesses 53d and the recesses 53h, and an outer peripheral wall surrounding the recesses 53d and the recesses 53h.

[0087] The connecting portion 5a2 is disposed to surround the holding portion 5a1 when viewed in the direction along the Z axis. The connecting portion 5a2 is in the form of a plate extending from the side wall portion 5a12 in a direction perpendicular to the Z axis, and connects the side wall portion 5a12 and the outer wall portion 5b over the entire circumference. The connecting portion 5a2 may have a shape having a missing portion, or may be composed of a plurality of portions arranged at intervals in the circumferential direction.

[0088] The outer wall portion 5b has a frame shape extending in the Z1 direction from the peripheral edge of the bottom portion 5a over the entire periphery, and constitutes the side surface of the recess 53a described above.

[0089] The flange portion 5c is a plate-like member protruding outward from the end of the outer wall portion 5b in the Z1 direction in a direction perpendicular to the Z axis. In this manner, the inner peripheral edge of the flange portion 5c is connected to the outer peripheral edge of the connection portion 5a2 of the bottom portion 5a via the outer wall portion 5b. In the example shown in FIG. 7 and FIG. 8, the flange portion 5c is rectangular or substantially rectangular in plan view. Therefore, the outer shape of the holder 53 in plan view is rectangular or substantially rectangular. In addition to the above-mentioned multiple screw holes 53i and multiple screw holes 53k, multiple holes 53j are provided in the flange portion 5c. The multiple holes 53j are holes into which protrusions (not shown) provided on the support 41 are inserted to position the holder 53 relative to the support 41.

[0090] 1-6. Shape of the holder's holding part Fig. 9 is a diagram for explaining the shape of holding portion 5a1 of holder 53 in the first embodiment. For convenience of explanation, in Fig. 9, the respective outlines of holding portion 5a1 and a plurality of head chips 54 as viewed in the Z2 direction are shown by solid lines.

[0091] 9, in a plan view seen in the direction along the Z axis, outer edge OE1 of holding portion 5a1 has a shape corresponding to the arrangement of head chips 54_1, 54_2, 54_3, and 54_4. That is, outer edge OE1 has a shape in which a pair of diagonal corners of the four corners of a rectangle and their neighboring parts are cut out into a substantially rectangular shape in a plan view. The arrangement of head chips 54_1, 54_2, 54_3, and 54_4 and the plan view shape of outer edge OE1 of holding portion 5a1 will be described in detail below.

[0092] 9, head chip 54_1, head chip 54_2, head chip 54_3 and head chip 54_4 are arranged in a staggered manner in a plan view. Head chip 54_1 and head chip 54_2 are adjacent to each other, head chip 54_2 and head chip 54_3 are adjacent to each other, and head chip 54_3 and head chip 54_4 are adjacent to each other.

[0093] Specifically, head chip 54_1, head chip 54_2, head chip 54_3, and head chip 54_4 are arranged in this order in the X1 direction. However, head chip 54_1 and head chip 54_3 are arranged at positions shifted in the Y1 direction with respect to head chip 54_2 and head chip 54_4. Here, head chip 54_1 and head chip 54_3 are arranged side by side in the direction along the X axis so as to align their positions with each other in the direction along the Y axis. Similarly, head chip 54_2 and head chip 54_4 are arranged side by side in the direction along the X axis so as to align their positions with each other in the direction along the Y axis. In addition, the planar shape of each head chip 54 is a rectangle or a substantially rectangle extending in the direction along the Y axis.

[0094] In Fig. 9, a virtual rectangle VS circumscribing the assembly of head chips 54_1, 54_2, 54_3, and 54_4 arranged as described above is indicated by a two-dot chain line in a plan view. Rectangle VS is the smallest rectangle that contains the assembly in a plan view. In this embodiment, each of the multiple head chips 54_1, 54_2, 54_3, and 54_4 contacts the virtual rectangle VS. In the example shown in Fig. 9, the assembly has a two-fold symmetric shape in a plan view.

[0095] The outer edge OE1 of the holding portion 5a1 has a portion located inside the rectangle VS and a portion located outside the rectangle VS.

[0096] Here, assuming that the four sides of rectangle VS are first side E1, second side E2, third side E3, and fourth side E4, head chip 54_1 contacts first side E1 and third side E3 in a plan view. Head chip 54_2 contacts second side E2 in a plan view. Head chip 54_3 contacts third side E3 in a plan view. Head chip 54_4 contacts second side E2 and fourth side E4 in a plan view.

[0097] However, the first side E1 is one of the four sides of the rectangle VS. The second side E2 is a side connected to one end of the first side E1 of the four sides of the rectangle VS. The third side E3 is a side connected to the other end of the first side E1 of the four sides of the rectangle VS. The fourth side E4 is a side other than the first side E1, the second side E2, and the third side E3 of the four sides of the rectangle VS.

[0098] A first region RE1 surrounded by a first side E1, a second side E2, head chip 54_1, and head chip 54_2 in a plan view is divided into a first inner portion RE1a and a first outer portion RE1b by an outer edge OE1. The first inner portion RE1a is a portion of the first region RE1 located inside the outer edge OE1. The first outer portion RE1b is a portion of the first region RE1 located outside the outer edge OE1. In addition, the first region RE1 is a rectangular region surrounded by the first side E1, the second side E2, a straight line along the shorter side of the two short sides of head chip 54_1 that is closer to head chip 54_2, and a straight line along the longer side of the two long sides of head chip 54_2 that is closer to head chip 54_1 in a plan view.

[0099] Here, the first side E1 has a first portion PA1 that defines the first region RE1. The first portion PA1 is a side that belongs to the first side E1 among the four sides of the rectangular first region RE1. The second side E2 has a second portion PA2 that defines the first region RE1. The second portion PA2 is a side that belongs to the second side E2 among the four sides of the rectangular first region RE1. In addition, in a plan view, the outer edge OE1 of the retaining portion 5a1 intersects with both the first portion PA1 and the second portion PA2.

[0100] In plan view, an intersection IPa between the outer edge OE1 of the holding portion 5a1 and the first portion PA1 is located closer to the head chip 54_1 than a midpoint MP1 of the first portion PA1, and an intersection IPb between the outer edge OE1 of the holding portion 5a1 and the second portion PA2 is located closer to the head chip 54_2 than a midpoint MP2 of the second portion PA2. In the example shown in Fig. 9, the intersection IPb is located very close to the midpoint MP2, but is located in the X1 direction with respect to the midpoint MP2.

[0101] Furthermore, the center CP of the first region RE1 is located outside the outer edge OE1 of the holding portion 5a1 in a plan view. That is, the center CP of the first region RE1 is not included inside the outer edge OE1 of the holding portion 5a1. Note that in the example shown in FIG. 9, the center CP is located very close to the outer edge OE1, but outside the outer edge OE1.

[0102] As with the first region RE1 described above, the second region RE2 is surrounded by the third side E3, the fourth side E4, the head chip 54_3, and the head chip 54_4 in a plan view, and is divided into a second inner portion RE2a and a second outer portion RE2b by the outer edge OE1. The second inner portion RE2a is located inside the outer edge OE1. The second outer portion RE2b is located outside the outer edge OE1. The second region RE2 is a rectangular region surrounded by the third side E3, the fourth side E4, a straight line along the longer side of the two longer sides of the head chip 54_3 that is closer to the head chip 54_4, and a straight line along the shorter side of the two shorter sides of the head chip 54_4 that is closer to the head chip 54_3 in a plan view.

[0103] 1-7.Heater shape Fig. 10 is a diagram for explaining the shapes of the heater 56 and the heat transfer member 57 in the first embodiment. For convenience of explanation, the outlines of the heater 56 and the head chips 54 as viewed in the Z2 direction are shown by solid lines in Fig. 10. Also, in Fig. 10, the outlines of the flow path structure 51 or the heat transfer member 57 as viewed in the Z2 direction are shown by dashed lines.

[0104] As shown in Fig. 10, in plan view in the direction along the Z axis, the outer edge OE2 of the heater 56 has a shape corresponding to the arrangement of the head chips 54_1, 54_2, 54_3, and 54_4. In this embodiment, the outer edge OE2 has roughly the same shape as the outer edge OE1 of the holding portion 5a1 described above, as shown in Fig. 8 described above. In other words, it can be said that the outer edge OE2 has a shape that follows the outer edge OE1. Below, the plan view shape of the outer edge OE2 of the heater 56 will be described in detail one by one.

[0105] 10, the imaginary rectangle VS described above is indicated by a two-dot chain line. The outer edge OE2 of the heater 56 has a portion located inside and a portion located outside the rectangle VS, similar to the outer edge OE1 of the holding portion 5a1 described above.

[0106] In a plan view, the first region RE1 is divided into a first inner portion RE1c and a first outer portion RE1d by the outer edge OE2. The first inner portion RE1c is a portion of the first region RE1 located on the inside of the outer edge OE2. The first outer portion RE1d is a portion of the first region RE1 located on the outside of the outer edge OE2. In this embodiment, since the outer edge OE2 has roughly the same shape as the outer edge OE1 of the retaining portion 5a1 as described above, the first inner portion RE1c is approximately equal to the first inner portion RE1a described above, and the first outer portion RE1d is approximately equal to the first outer portion RE1b.

[0107] Here, in plan view, the outer edge OE2 of the heater 56 includes multiple head chips 54 and intersects with both the first portion PA1 and the second portion PA2. In addition, in plan view, the intersection IPc between the outer edge OE2 of the heater 56 and the first portion PA1 is located closer to the head chip 54_1 than the midpoint MP1 of the first portion PA1, and the intersection IPd between the outer edge OE2 of the heater 56 and the second portion PA2 is located closer to the head chip 54_2 than the midpoint MP2 of the second portion PA2. In the example shown in FIG. 10, the intersection IPd is located very close to the midpoint MP2, but is located in the X1 direction with respect to the midpoint MP2.

[0108] The center CP of the first region RE1 is located outside the outer edge OE2 in a plan view. That is, the center CP of the first region RE1 is not included inside the outer edge OE2 of the heater 56. Note that in the example shown in FIG. 10, the center CP is located very close to the outer edge OE2, but outside the outer edge OE2.

[0109] As with the first region RE1 described above, the second region RE2 is divided into a second inner portion RE2c and a second outer portion RE2d by the outer edge OE2 in a plan view. The second inner portion RE2c is located inside the outer edge OE2. The second outer portion RE2d is located outside the outer edge OE2. In this embodiment, the second inner portion RE2c is approximately equal to the second inner portion RE2a described above, and the second outer portion RE2d is approximately equal to the second outer portion RE2b.

[0110] 10 includes head chips 54_1, 54_2, 54_3, and 54_4, and also overlaps at least a portion of each of first outer portion RE1d and second outer portion RE2d in a plan view. Similarly, although not shown, heat transfer member 57 overlaps at least a portion of each of first outer portion RE1b and second outer portion RE2b shown in FIG. 9 in a plan view.

[0111] Here, the shape of the heat transfer member 57 in a plan view is substantially equal to the shape of the flow path structure 51 in a plan view. Therefore, in a plan view, the flow path structure 51 overlaps at least a portion of each of the first outer portion RE1d and the second outer portion RE2d. Similarly, although not shown, in a plan view, the flow path structure 51 overlaps at least a portion of each of the first outer portion RE1b and the second outer portion RE2b shown in FIG. 9 described above.

[0112] 1-8.Heat transfer path from heater Fig. 11 is a diagram for explaining the heat transfer path H1 and the heat transfer path H2 from the heater 56 in the first embodiment. In Fig. 11, the heat transfer path H1 and the heat transfer path H2 are each diagrammatically indicated by a dashed line.

[0113] As described above, the support 41 is provided with an opening 41a into which the outer wall portion 5b is inserted. Meanwhile, the flange portion 5c has an attachment surface 5c1 facing the Z2 direction, which is the normal direction of the nozzle surface FN. The holder 53 is attached to the support 41 with the outer wall portion 5b inserted into the opening 41a with a gap d1 between the outer wall portion 5b and the support 41, and with the attachment surface 5c1 in contact with the support 41.

[0114] As described above, the heater 56 heats each head chip 54 by transmitting heat to each head chip 54 through the transmission path H1.

[0115] However, some of the heat from heater 56 is transferred to support 41 via holder 53. That is, some of the heat from heater 56 is not used to heat each head chip 54, and escapes to support 41 via holder 53. Such escape of heat not only reduces the heating efficiency of each head chip 54 by heater 56, but also causes variations in temperature distribution within each head chip 54 or between head chips 54.

[0116] In order to reduce such heat loss, the holder 53 has a configuration that enhances thermal resistance in the heat transfer path H2 from the heater 56 to the support 41. Specifically, in the holder 53, as described above, the heat receiving portion 5a11 and the flange portion 5c are connected via the side wall portion 5a12, the connection portion 5a2, and the outer wall portion 5b.

[0117] The heat transfer path H2 is a path through which heat is transferred to the heat receiving portion 5a11, the side wall portion 5a12, the connection portion 5a2, the outer wall portion 5b, and the flange portion 5c in this order. As described above, the side wall portion 5a12 and the outer wall portion 5b each extend in a direction along the Z axis, while the connection portion 5a2 and the flange portion 5c each extend in a direction intersecting the Z axis. Therefore, when viewed in a cross section as shown in FIG. 11, the heat transfer path H2 is bent or curved at least at two points between the heat receiving portion 5a11 and the flange portion 5c. In FIG. 11, the two bent or curved points of the heat transfer path H2 are indicated by the areas surrounded by two-dot chain lines.

[0118] Here, the outer peripheral surface of the side wall portion 5a12 is disposed at a distance d3 from the inner peripheral surface of the outer wall portion 5b over the entire area. Therefore, heat is not transferred directly from the side wall portion 5a12 to the outer wall portion 5b but via the connection portion 5a2. Moreover, the flow path structure 51 is disposed at a distance d2 from the outer wall portion 5b. Therefore, heat is not transferred from the heat receiving portion 5a11 to the outer wall portion 5b via the flow path structure 51.

[0119] As described above, the liquid ejection head 50 includes a plurality of head chips 54, a thermally conductive holder 53, a thermally conductive flow path structure 51, and a planar heater 56. Each of the plurality of head chips 54 has a nozzle surface FN on which a nozzle N for ejecting ink, which is an example of a "liquid", is provided. The holder 53 holds the plurality of head chips 54. The flow path structure 51 is provided with a flow path for ink to be supplied to the plurality of head chips 54. The heater 56 is disposed between the holder 53 and the flow path structure 51, and is aligned in a direction parallel to the nozzle surface FN. In addition, the heater 56 overlaps the plurality of head chips 54 in a planar view.

[0120] In the above liquid jet head 50, the heater 56 is disposed between the holder 53 and the flow path structure 51. Therefore, compared to a conventional configuration in which the flow path structure 51 is interposed between the heater 56 and the holder 53, the heat from the heater 56 can be transferred more efficiently to each of the holder 53 and the flow path structure 51. As a result, the temperature difference between the holder 53 and the flow path structure 51 can be reduced, and further, the temperature difference between the head chip 54 and the flow path structure 51 can be reduced. In addition, the heater 56 has a planar shape that is parallel to the nozzle surface, and the heater 56 overlaps with the multiple head chips 54 in a planar view. Therefore, compared to a configuration in which the heater 56 overlaps only a portion of the multiple head chips 54 in a planar view, the heat from the heater 56 can be transferred more efficiently to each of the multiple head chips 54. As a result, the temperature difference between the multiple head chips 54 can also be reduced. From the above, the temperature of the head chip 54 can be managed with high precision by controlling the temperature of the heater 56.

[0121] In this embodiment, as described above, holder 53 has holding portion 5a1 that holds multiple head chips 54. Holding portion 5a1 contains multiple head chips 54 in a plan view. Therefore, heat from heater 56 can be transferred to multiple head chips 54 via one holding portion 5a1. As a result, there is no need to provide a heater 56 for each head chip 54, and heater 56 can be easily installed.

[0122] In addition, each of the multiple head chips 54 is elongated along the direction along the Y axis. The multiple head chips 54 include head chip 54_1, which is an example of the "first head chip", and head chip 54_2, which is an example of the "second head chip". Head chip 54_1 and head chip 54_2 are adjacent to each other. Here, "the multiple head chips are adjacent" refers to the positional relationship between the multiple head chips 54, and a configuration other than head chip 54 (for example, corresponding to the 5a12 side wall portion of holder 53 in this embodiment) may be interposed between the multiple head chips 54. In addition, head chip 54_1 and head chip 54_3 are arranged at the same position in the direction along the Y axis while being shifted from each other in the direction along the X axis, with the end of head chip 54_2 in the Y1 direction interposed therebetween. However, head chip 54_1 and head chip 54_3 are positioned opposite each other in the direction along the X-axis at more than half the dimension of head chip 54 in the direction along the Y-axis. Therefore, it can be said that head chip 54_1 and head chip 54_3 are also adjacent to each other. Head chip 54_1 and head chip 54_2 are arranged shifted from each other in both the direction along the Y-axis and the direction along the X-axis. When two directions that intersect with each other along nozzle surface FN are defined as a first direction and a second direction, the direction along the Y-axis is an example of the "first direction," and the direction along the X-axis is an example of the "second direction."

[0123] Here, head chip 54_1 contacts first side E1 and third side E3 of imaginary rectangle VS in plan view, and head chip 54_2 contacts second side E2 in plan view. A first region RE1 surrounded by first side E1, second side E2, head chip 54_1, and head chip 54_2 in plan view includes a first outer portion RE1b located outside outer edge OE1 of holding portion 5a1. Outer edge OE1 is the outer edge of side wall portion 5a12 in plan view.

[0124] As described above, the rectangle VS circumscribes the assembly of the multiple head chips 54 of the liquid ejection head 50 in a plan view. The first side E1 is one of the four sides of the rectangle VS. The second side E2 is one of the four sides of the rectangle VS that is connected to one end of the first side E1. The third side E3 is one of the four sides of the rectangle VS that is connected to the other end of the first side E1.

[0125] In the first outer portion RE1b, neither the holding portion 5a1 nor the head chip 54 exists. Therefore, the presence of such a first outer portion RE1b means that the unnecessary portions other than the portions of the holding portion 5a1 to be heated are reduced. This reduces the amount of heat from the heater 56 escaping to the unnecessary portions, and as a result, the head chip 54 can be efficiently heated by the heater 56. Another advantage is that the area of ​​the heater 56 can be reduced or the power consumption can be reduced.

[0126] As described above, the holder 53 is provided with a plurality of ink holes 53b, and the plurality of ink holes 53b form a flow path for ink to be supplied to the plurality of head chips 54. Therefore, from the viewpoints of increasing the resistance of the holder 53 to ink and efficiently transmitting heat from the heater 56 to the ink in the ink holes 53b via the holder 53, it is preferable that the holder 53 be made of stainless steel or ceramics.

[0127] Moreover, in plan view, first region RE1 includes first outer portion RE1d that does not overlap heater 56. This allows heater 56 to have a small area. Since head chip 54_1 and head chip 54_2 are not present in first outer portion RE1d, unnecessary heat generation by heater 56 can be reduced. As a result, head chip 54 can be efficiently heated by heater 56.

[0128] Furthermore, as described above, the liquid jet head 50 further includes a heat transfer member 57 which is an example of the "second heat transfer member". The heat transfer member 57 is disposed between the heater 56 and the flow path structure 51, and is a member having a higher thermal conductivity than the flow path structure 51, for example, aluminum. In a plan view, the heat transfer member 57 and the flow path structure 51 overlap with the first outer portion RE1b. The flow path structure 51 is present in the first outer portion RE1b, so that the degree of freedom of layout of the flow paths in the flow path structure 51 can be increased. In addition, since the heat transfer member 57 is disposed between the heater 56 and the flow path structure 51, the heat from the heater 56 can be transferred to the flow path structure 51 after being spread in the planar direction by the second heat transfer member. In particular, even if the first outer portion RE1b has a portion where the flow path structure 51 is present, the heat transfer member 57 is also present in the first outer portion RE1b, so that the heat from the heater 56 can be transferred to the portion via the heat transfer member 57. As a result, the variation in temperature distribution of the flow path structure 51 caused by the heater 56 can be reduced.

[0129] Furthermore, as described above, from the viewpoints of increasing the resistance of the flow path structure 51 to ink and efficiently transferring heat from the heater 56 to the ink in the flow path structure 51, it is preferable that the flow path structure 51 be made of stainless steel or ceramics.

[0130] In the present embodiment, the multiple head chips 54 include head chip 54_3, which is an example of a “third head chip,” and head chip 54_4, which is an example of a “fourth head chip.” Head chip 54_3 and head chip 54_4 are arranged to be shifted from each other in both the direction along the Y axis and the direction along the X axis.

[0131] Here, when the side other than first side E1, second side E2, and third side E3 among the four sides of the imaginary rectangle VS is defined as a fourth side E4, head chip 54_3 contacts third side E3 in a plan view, and head chip 54_4 contacts second side E2 and fourth side E4 in a plan view. Then, second region RE2 surrounded by third side E3, fourth side E4, head chip 54_3, and head chip 54_4 in a plan view includes a second outer portion RE2b located outside outer edge OE1 of holding portion 5a1.

[0132] In the second outer portion RE2b, like the first outer portion RE1b described above, the holding portion 5a1 does not exist, and neither does the head chip 54 exist. Therefore, the presence of such a second outer portion RE2b means that the unnecessary portions other than the portions of the holding portion 5a1 to be heated are reduced. This makes it possible to reduce the amount of heat from the heater 56 escaping to the unnecessary portions, and as a result, the head chip 54 can be efficiently heated by the heater 56. Another advantage is that the area of ​​the heater 56 can be reduced or power consumption can be reduced.

[0133] The area of ​​the first outer portion RE1b is preferably 1 / 4 or more of the area of ​​the first region RE1, and more preferably 1 / 2 or more and 9 / 10 or less of the area of ​​the first region RE1. When the area of ​​the first outer portion RE1b is within such a range, the above-mentioned unnecessary portion of the holding portion 5a1 can be suitably reduced. On the other hand, if the area of ​​the first outer portion RE1b is too small, the power consumption of the heater 56 tends to increase, and the temperature distribution in each head chip 54 or among multiple head chips 54 tends to be easily varied. On the other hand, if the area of ​​the first outer portion RE1b is too large, it is difficult to ensure the necessary thickness for the holding portion 5a1. The area of ​​the second outer portion RE2b is also preferably 1 / 4 or more of the area of ​​the second region RE2, similar to the relationship between the area of ​​the first outer portion RE1b and the first region RE1.

[0134] As described above, the heater 56 overlaps with the multiple head chips 54 in plan view. The first region RE1 described above includes a first outer portion RE1d located outside the outer edge OE2 of the heater 56 in plan view.

[0135] In the first outer portion RE1d, neither heater 56 nor head chip 54 exists. Therefore, the presence of such a first outer portion RE1d means that unnecessary portions of the heater 56 are reduced. This makes it possible to reduce the variation in temperature distribution within each head chip 54 or among multiple head chips 54, which is caused by heat generation in the unnecessary portions. Another advantage is that the area of ​​the heater 56 can be reduced or power consumption can be reduced.

[0136] Here, in a plan view, the heat transfer member 57 and the flow path structure 51 overlap with the first outer portion RE1d. The presence of the flow path structure 51 in the first outer portion RE1d can increase the degree of freedom of layout of the flow paths in the flow path structure 51. Even if the first outer portion RE1d has a portion where the flow path structure 51 exists, the heat transfer member 57 also exists in the first outer portion RE1d, so that heat from the heater 56 can be transferred to the portion via the heat transfer member 57. As a result, it is possible to reduce variation in the temperature distribution of the flow path structure 51 due to the heater 56. Note that this is particularly useful in a configuration where a part of the flow path in the flow path structure 51 overlaps with the first outer portion RE1d in a plan view.

[0137] As described above, the second region RE2 includes the second outer portion RE2d located outside the outer edge OE2 of the heater 56 in a plan view.

[0138] In the second outer portion RE2d, similar to the first outer portion RE1d described above, there is no heater 56 and no head chip 54. Therefore, the presence of such a second outer portion RE2d means that unnecessary portions of the heater 56 are reduced. This makes it possible to reduce the variation in temperature distribution within each head chip 54 or among multiple head chips 54, which is caused by heat generation in the unnecessary portions. Another advantage is that the area of ​​the heater 56 can be reduced or power consumption can be reduced.

[0139] The area of ​​the first outer portion RE1d is preferably 1 / 4 or more of the area of ​​the first region RE1, and more preferably 1 / 2 or more and 9 / 10 or less of the area of ​​the first region RE1. When the area of ​​the first outer portion RE1d is within such a range, unnecessary parts of the heater 56 can be suitably reduced. On the other hand, if the area of ​​the first outer portion RE1d is too small, the power consumption of the heater 56 increases, and the temperature distribution within each head chip 54 or among multiple head chips 54 tends to be easily varied. On the other hand, if the area of ​​the first outer portion RE1d is too large, depending on the size of the holding portion 5a1, it is difficult to uniformly transfer heat from the heater 56 to the holding portion 5a1, and in this respect, the temperature distribution within each head chip 54 or among multiple head chips 54 tends to be easily varied. In addition, the area of ​​the second outer portion RE2d is preferably 1 / 4 or more of the area of ​​the second region RE2, similar to the relationship between the area of ​​the first outer portion RE1d and the first region RE1.

[0140] As described above, the liquid jet head 50 is supported by the support 41. Here, the holder 53 has, in addition to the holding portion 5a1, a flange portion 5c that contacts the support 41 at a position away from the holding portion 5a1. The heater 56 heats the holding portion 5a1. The holding portion 5a1 has a heat receiving portion 5a11 that receives heat from the heater 56.

[0141] In addition, the shortest path of heat transmission from the heat receiving portion 5a11 to the flange portion 5c in the holder 53 among the transmission paths H2 is bent or curved at two or more points. Here, the bent or curved path refers to a state in which, for example, when the side wall portion 5a12 is bent or curved between the side wall portion 5a12 and the connecting portion 5a2 as in this embodiment, the length of the side wall portion 5a12 along the transmission path H2 (in other words, the length of the side wall portion 5a12 in the direction along the Z axis) and the length of the connecting portion 5a2 along the transmission path H2 (in other words, the length of the connecting portion 5a2 in the direction along the Y axis) are longer than the thickness of the side wall portion 5a12 in the thickness direction (direction along the Y axis) and longer than the thickness of the connecting portion 5a2 in the thickness direction (direction along the Z axis). This is the same when the side wall portion 5a12 is bent or curved between the connecting portion 5a2 and the outer wall portion 5b, and when the side wall portion 5a12 is bent or curved at a portion other than these portions. The "shortest path from the heat receiving portion 5a11 to the flange portion 5c" does not include the path of heat moving inside the heat receiving portion 5a11 and the flange portion 5c. More specifically, the "shortest path from the heat receiving portion 5a11 to the flange portion 5c" is the shortest path from an arbitrary position of the heat receiving portion 5a11 to the contact position between the flange portion 5c and the support 41 that passes through the holder 53, not including the path of heat moving inside the heat receiving portion 5a11 and the flange portion 5c. Therefore, the thermal resistance of the shortest path can be increased compared to a configuration in which the shortest path from the heat receiving portion 5a11 to the flange portion 5c is linear, or a configuration in which the thickness of the connection portion 5a2 is increased so that the surface of the connection portion 5a2 facing the Z1 direction coincides with the first surface F1. Therefore, it is possible to make it difficult for heat from the heater 56 to be dissipated to the support 41 via the flange portion 5c. As a result, the head chip 54 can be efficiently heated by the heater 56.

[0142] As described above, the heater 56 is disposed at a position opposite (Z1 direction) to the normal direction (Z2 direction) of the nozzle surface FN with respect to the holding portion 5a1. The holding portion 5a1 further has a side wall portion 5a12 extending from the heat receiving portion 5a11 in the normal direction (Z2 direction). The heat receiving portion 5a11 and the side wall portion 5a12 form a recess 53d, which is an example of a "space" that accommodates the head chip 54. For this reason, the head chip 54, the holder 53, and the heater 56 can be easily assembled by stacking them in this order.

[0143] In addition, the holder 53 further includes an outer wall portion 5b that is connected to the flange portion 5c and surrounds the side wall portion 5a12 when viewed in the normal direction, and a connection portion 5a2 that connects the side wall portion 5a12 and the outer wall portion 5b. The connection portion 5a2 extends in a direction intersecting the normal direction, and the side wall portion 5a12 and the outer wall portion 5b each extend from the connection portion 5a2 in a direction opposite to the normal direction.

[0144] Thus, the holder 53 has a holding portion 5a1 that holds the head chip 54, a flange portion 5c that contacts the support 41 at a position away from the holding portion 5a1, an outer wall portion 5b that is connected to the flange portion 5c and surrounds the holding portion 5a1 when viewed in the normal direction of the nozzle surface FN, and a connection portion 5a2 that connects the holding portion 5a1 and the outer wall portion 5b. The holding portion 5a1 protrudes from the connection portion 5a2 in the direction opposite to the normal direction, and the outer wall portion 5b extends from the connection portion 5a2 toward the flange portion 5c in the direction opposite to the normal direction.

[0145] By configuring the holder 53 in this way, the shortest path of the transfer path H2 from the heat receiving portion 5a11 to the flange portion 5c has a portion that is bent or curved due to the connection between the side wall portion 5a12 and the connection portion 5a2, and a portion that is bent or curved due to the connection between the outer wall portion 5b and the connection portion 5a2. In other words, in the shortest path of the transfer path H2 from the heat receiving portion 5a11 to the flange portion 5c, the heat transfer direction at the side wall portion 5a12 and the heat transfer direction at the outer wall portion 5b are opposite to each other.

[0146] As described above, the outer wall portion 5b surrounds the holding portion 5a1 with a gap therebetween in a plan view, so that the transmission path H2 that bends or curves at two or more points as described above can be easily realized between the heat receiving portion 5a11 and the flange portion 5c.

[0147] Furthermore, as described above, the flange portion 5c is disposed at a position opposite to the normal direction of the nozzle surface FN from the heat receiving portion 5a11. Therefore, the outer wall portion 5d can be elongated in the direction along the Z axis, and the thermal resistance of the transfer path H2 can be increased.

[0148] As described above, the heat receiving portion 5a11 has a first surface F1 and a second surface F2 facing in opposite directions. Here, the first surface F1 is a heat receiving surface that receives heat from the heater 56. The head chip 54 has a case 54h in which an ink flow path is provided. The case 54h is fixed to the second surface F2 and is made of a material having a lower thermal conductivity than the holder 53. In this way, by making the thermal conductivity of the material of the case 54h lower than that of the holder 53, it is possible to reduce heat dissipation from the ink in the head chip 54. Here, the heat from the heat receiving portion 5a11 is difficult to transfer to the case 54h, and as a result, it becomes easier to move through the holder 53 in a direction relatively toward the support 41. Therefore, when such a case 54h is used, it is particularly useful to make it difficult to dissipate heat from the support 41 as described above.

[0149] Furthermore, as described above, the flow path structure 51 is disposed at a position opposite to the normal direction of the nozzle surface FN with respect to the holding portion 5a1, and the heater 56 is disposed between the holding portion 5a1 and the flow path structure 51. The flow path structure 51 is disposed at a distance from the outer wall portion 5b. This makes it possible to reduce direct heat dissipation from the flow path structure 51 to the outer wall portion 5b.

[0150] As described above, the outer circumferential surface of the side wall portion 5a12 is spaced apart from the inner circumferential surface of the outer wall portion 5b over the entire area when viewed in the normal direction of the nozzle surface FN, thereby reducing direct heat dissipation from the side wall portion 5a12 to the outer wall portion 5b.

[0151] Furthermore, as described above, the flange portion 5c surrounds the entire outer wall portion 5b when viewed in the normal direction of the nozzle surface FN. Therefore, the flange portion 5c can prevent mist generated by the ejection of ink from the head chip 54 from flowing from the nozzle surface FN to a position vertically above the support body 41. On the other hand, the flange portion 5c may cause heat from the heater 56 to be dissipated to the support body 41 from the entire circumference of the flange portion 5c surrounding the outer wall portion 5b. However, as described above, the outer peripheral surface of the side wall portion 5a12 is spaced apart from the inner peripheral surface of the outer wall portion 5b when viewed in the normal direction of the nozzle surface FN, so that direct heat dissipation from the side wall portion 5a12 to the outer wall portion 5b can be reduced.

[0152] 2. Second embodiment A second embodiment of the present invention will be described below. In the following example, for elements having the same actions and functions as those in the first embodiment, the reference numerals used in the description of the first embodiment will be used and detailed descriptions of each will be omitted as appropriate.

[0153] 12 is an exploded perspective view of a liquid jet head 50A according to the second embodiment. The liquid jet head 50A is similar to the liquid jet head 50 according to the first embodiment described above, except that the arrangement of the heater 56 and the heat transfer member 57 is different.

[0154] 12, in this embodiment, the arrangement order of the heater 56 and the heat transfer member 57 in the direction along the Z axis is reversed from that of the first embodiment described above. That is, in the liquid jet head 50A, the cover 58, the substrate unit 52, the flow path structure 51, the heater 56, the heat transfer member 57, the holder 53, the four head chips 54, and the fixed plate 55 are arranged in this order along the Z2 direction. The heat transfer member 57 in this embodiment is an example of a "first heat transfer member."

[0155] According to the second embodiment described above, the temperature of the head chip 54 can be controlled with high precision, as in the first embodiment described above. In the example shown in Fig. 13, the shapes of the flow path structure 51, the heater 56, and the heat transfer member 57 in plan view are the same as those in the first embodiment described above. That is, the heat transfer member 57 overlaps the first outer portion RE1b in plan view. Furthermore, when the heater 56 and the flow path structure 51 each overlap the first outer portion RE1b in plan view, the heat from the heater 56 can be transferred to the holding portion 5a1 without waste.

[0156] However, the shape of the heater 56 in a plan view is not limited thereto, and may be the same as the shape of the flow path structure 51 or the heat transfer member 57 in a plan view, for example. That is, in a plan view, each of the heater 56 and the flow path structure 51 may overlap the first outer portion RE1b. In this case, even if the heat transfer member 57 does not exist between the heater 56 and the flow path structure 51, the variation in temperature distribution of the flow path structure 51 can be reduced.

[0157] Furthermore, the shape of the heat transfer member 57 in a plan view may be, for example, substantially the same as the shape of the heater 56 in a plan view. That is, the heat transfer member 57 may not substantially overlap the first outer portion RE1b in a plan view. Here, "the heat transfer member 57 does not substantially overlap the first outer portion RE1b" includes a case where a portion of the first region RE1 outside the outer edge of the heat transfer member 57 does not overlap with the first outer portion RE1b by 1 / 2 or more of the area of ​​the first outer portion RE1b. More preferably, "the heat transfer member 57 does not substantially overlap the first outer portion RE1b" refers to a case where a portion of the first region RE1 outside the outer edge of the heat transfer member 57 does not overlap with the first outer portion RE1b by 3 / 4 or more of the area of ​​the first outer portion RE1b.

[0158] Since a heat transfer member 57 is interposed between the heater 56 and the holder 53, the heat transfer member 57 makes it easier for the heat from the heater 56 to move in a direction parallel to the nozzle surface FN, thereby reducing variations in the temperature distribution of the holding portion 5a1.

[0159] 3. Third embodiment The third embodiment of the present invention will be described below. In the following exemplary embodiment, for elements having the same actions and functions as those in the first embodiment, the reference numerals used in the description of the first embodiment will be used and detailed descriptions of each will be omitted as appropriate.

[0160] 13 is a diagram for explaining a heat transfer path H1 and a heat transfer path H2 from a heater 56 in the third embodiment. A liquid jet head 50B in this embodiment is similar to the liquid jet head 50 in the first embodiment described above, except that it has a holder 53B instead of the holder 53. The holder 53B is similar to the holder 53, except that it has an outer wall portion 5d instead of the outer wall portion 5b.

[0161] The outer wall portion 5d connects the outer peripheral edge of the connection portion 5a2 of the bottom portion 5a to the inner peripheral edge of the flange portion 5c. Here, the outer wall portion 5d has a first wall portion 5d1, a first plate portion 5d2, a second wall portion 5d3, a second plate portion 5d4, and a third wall portion 5d5.

[0162] The first wall portion 5d1 is tubular and extends in the Z1 direction from the connecting portion 5a2. The first plate portion 5d2 is plate-shaped and extends from the first wall portion 5d1 in a direction perpendicular to the Z axis so as to approach the holding portion 5a1. The second wall portion 5d3 is tubular and extends in the Z1 direction from the first plate portion 5d2. The second plate portion 5d4 is plate-shaped and extends from the second wall portion 5d3 in a direction perpendicular to the Z axis so as to move away from the holding portion 5a1. The third wall portion 5d5 is tubular and extends in the Z1 direction from the second plate portion 5d4.

[0163] The third embodiment described above can also control the temperature of the head chip 54 with high accuracy, as in the first embodiment described above. In this embodiment, the bottom 5a and the flange 5c are connected via the outer wall 5d as described above, so that the heat transfer path H2 from the heater 56 to the support 41 is bent or curved at at least six points. In FIG. 13, the six bent or curved points of the transfer path H2 are shown as areas surrounded by two-dot chain lines. When the number of bent or curved points of the transfer path H2 is four or more, it is advantageous in that the thermal resistance of the transfer path H2 is easily increased compared to the first embodiment described above. Note that, as in the first embodiment described above, the "shortest path from the heat receiving portion 5a11 to the flange 5c" does not include the path of heat moving inside the heat receiving portion 5a11 and the flange 5c.

[0164] 4. Variations The above-mentioned exemplary embodiments may be modified in various ways. Specific modified embodiments that may be applied to the above-mentioned embodiments are exemplified below. Two or more embodiments selected from the following examples may be appropriately combined as long as they are not mutually contradictory.

[0165] 4-1. Variation 1 In the above-described embodiment, the shape of holding portion 5a1 in a plan view is a shape other than a rectangle depending on the arrangement of four head chips 54. The shape of holding portion 5a1 in a plan view is not limited to the above-described embodiment and may be, for example, a rectangle or a substantially rectangle.

[0166] 4-2. Variation 2 In the above-mentioned embodiment, the shape of the heater 56 in plan view is a shape other than a rectangle depending on the arrangement of the four head chips 54. The shape of the heater 56 in plan view is not limited to the above-mentioned embodiment, and may be, for example, a rectangle or a substantially rectangular shape. In addition, in the above-mentioned embodiment, the heater 56 is arranged between the flow path structure 51 and the holder 53, but this is not limited, and the flow path structure 51 may be interposed between the heater 56 and the holder 53. Furthermore, the installation posture of the heater 56 is not limited to a posture along the nozzle surface FN, and may be, for example, perpendicular or inclined with respect to the nozzle surface FN. In addition, the heater 56 is not limited to a planar shape, and may be, for example, a block shape.

[0167] 4-3. Variation 3 In the above-described embodiment, a configuration using one heat transfer member 57 is exemplified, but the present invention is not limited to this configuration, and may be, for example, a configuration in which the first embodiment and the second embodiment are combined. That is, the heat transfer members 57 may be disposed between the heater 56 and the holder 53 and between the heater 56 and the flow path structure 51, respectively.

[0168] 4-4. Variation 4 An elastic sheet may be disposed between the holder 53 and the flow path structure 51, both of which are rigid bodies. As such an elastic sheet, elastomers or the like can be used, and it is desirable to select a thermally conductive sheet having a higher thermal conductivity than the resin material constituting the case 54h of the head chip 54, for example. As such an elastic thermally conductive sheet having a higher thermal conductivity than the resin material, it is preferable to use a material having a thermal conductivity of 1.0 or more W / m·K or more. Specifically, as the thermally conductive sheet, an acrylic or silicon-based sheet, a material in which a metal material such as silicon, stainless steel, aluminum, titanium, or magnesium alloy is dispersed in an elastomer, or a composite material in which a filler such as a carbon-based material such as carbon fiber, a ceramic oxide such as silica or alumina, or a ceramic nitride such as silicon nitride or boron nitride is contained in an elastic material such as an elastomer, etc. are suitable. By filling the gap between the holder 53 and the flow path structure 51 with an elastic material in this manner, even if manufacturing errors occur in the thickness dimensions of the holder 53 or the flow path structure 51 in the direction along the Z axis, the adhesion between the heat transfer member 57 or the heater 56 and the object to be heated, such as the holder 53 or the flow path structure 51, can be increased, and heat from the heater 56 can be efficiently transferred to the object to be heated.

[0169] 4-5. Variation 5 The "outer edge OE2 of the heater 56" in the above embodiment may be interpreted as the outer edge of the region in which the heating resistor of the heater 56 is formed.

[0170] 4-6. Variation 6 In plan view, heater 56 does not have to overlap first outer portion RE1b. In this configuration, it is possible to reduce the area of ​​heater 56. Also, since head chip 54_1, head chip 54_2, and holding portion 5a1 are not present in first outer portion RE1b, heater 56 does not overlap first outer portion RE1b in plan view, and therefore unnecessary heat generation of heater 56 can be further reduced.

[0171] 4-7. Variation 7 In the above-described embodiment, a configuration in which the number of head chips 54 of the liquid ejection head 50 is four is exemplified, but the present invention is not limited to this configuration, and the number may be three or less, or five or more. In addition, in the above-described embodiment, the multiple head chips 54 are arranged in a staggered pattern along the longitudinal direction of the head chip 54, but the present invention is not limited to this configuration, and the multiple head chips 54 may be arranged in a staggered pattern along the lateral direction of the head chip 54.

[0172] 4-8. Variation 8 In the above embodiment, a serial type liquid ejection device 100 that reciprocates the support 41 supporting the liquid ejection head 50 is exemplified, but the present invention can also be applied to a line type liquid ejection device in which a plurality of nozzles N are distributed across the entire width of the medium M. In other words, the support that supports the liquid ejection head 50 is not limited to a serial type carriage, and may be a structure that supports the liquid ejection head 50 in the line type. In this case, for example, a plurality of liquid ejection heads 50 are arranged side by side in the width direction of the medium M, and the plurality of liquid ejection heads 50 are collectively supported by one support.

[0173] 4-9. Variation 9 The liquid ejection apparatus exemplified in the above-mentioned embodiment can be adopted in various devices such as facsimile machines and copy machines, in addition to devices dedicated to printing. However, the use of the liquid ejection apparatus is not limited to printing. For example, a liquid ejection apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus for forming a color filter of a display device such as a liquid crystal display panel. A liquid ejection apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming wiring and electrodes of a wiring board. A liquid ejection apparatus that ejects a solution of an organic substance related to a living body is used as a manufacturing apparatus for manufacturing a biochip, for example. [Explanation of symbols]

[0174] 5a...bottom, 5a1...holding portion, 5a11...heat receiving portion, 5a12...side wall portion, 5a2...connecting portion, 5b...outer wall portion, 5c...flange portion, 5c1...mounting surface, 5d...outer wall portion, 5d1...first wall portion, 5d2...first plate portion, 5d3...second wall portion, 5d4...second plate portion, 5d5...third wall portion, 10...liquid storage portion, 20...control unit, 30...transport mechanism, 40...movement mechanism, 41...support, 41a...opening, 41b...screw hole, 42...transport belt, 50...liquid jet head, 50A...liquid jet head, 50B...liquid jet head, 51...flow path structure, 51a...flow path member, 51b...connecting pipe, 51c...distribution Wire hole, 52... board unit, 52a... circuit board, 52b... connector, 52c... support plate, 53... holder, 53B... holder, 53a... recess, 53b... ink hole, 53c... wiring hole, 53d... recess, 53e... hole, 53f... hole, 53g... screw hole, 53h... recess, 53i... screw hole, 53j... hole, 53k... screw hole, 53l... flow path tube, 54... head chip, 54_1... head chip (first head chip), 54_2... head chip (second head chip), 54_3... head chip (third head chip), 54_4... head chip (fourth head chip), 54a... flow path Circuit board, 54b...pressure chamber board, 54c...nozzle plate, 54d...vibration absorber, 54e...vibration plate, 54f...piezoelectric element, 54g...protective plate, 54h...case, 54i...wiring board, 54j...drive circuit, 54k...frame, 55...fixed plate, 55a...opening, 56...heater, 56a...hole, 56b...hole, 57...heat transfer member, 57a...hole, 57b...wiring hole, 57c...hole, 58...cover, 58a...through hole, 58b...opening, 100...liquid ejection device, C...pressure chamber, CP...center, D...drive signal, DM...transport direction, E1...first side, E2...second side, E3...third side, E4...fourth side, F1...first surface, F2...second surface, FN...nozzle surface, H1...transmission path, H2...transmission path (shortest path), IO...inlet, IPa...intersection, IPb...intersection, IPc...intersection, IPd...intersection, L1...first row, L2...second row, M...medium, MP1...midpoint, MP2...midpoint, N...nozzle, Na...communicating flow path, OE1...outer edge, OE2...outer edge, PA1...first portion, PA2...second portion, R...reservoir, R1...space, R2...space, RE1...first region, RE1a...first inner portion, RE1b...first outer portion, RE1c...first inner portion, RE1d...first outer portion, RE2...second region, RE2a...second inner portion,RE2b... the second outer part, RE2c... the second inner part, RE2d... the second outer part, Ra... the supply flow path, S... the control signal, VS... the rectangle.

Claims

1. A liquid jet head supported by a support, a first head chip for ejecting liquid; a holder having a holding portion for holding the first head chip and a flange portion for contacting the support at a position separated from the holding portion; A heater that heats the holding portion, the holding portion has a heat receiving portion that receives heat from the heater, the heat receiving portion is disposed between the first head chip and the heater, The shortest path for heat to be transmitted through the holder from the heat receiving portion to the flange portion is bent or curved at two or more points. A liquid jet head comprising:

2. A liquid ejection head supported by a support, comprising: a first head chip for ejecting liquid; a holder having a holding portion for holding the first head chip and a flange portion for contacting the support at a position separated from the holding portion; A heater that heats the holding portion, the holding portion has a heat receiving portion that receives heat from the heater, The shortest path for heat to be transmitted through the holder from the heat receiving portion to the flange portion is bent or curved at two or more points, the first head chip has a nozzle surface on which nozzles for ejecting liquid in an ejection direction are provided; the heater is disposed at a position opposite to the ejection direction with respect to the holding portion, The holding portion further includes a side wall portion extending in the ejection direction from the heat receiving portion, the heat receiving portion and the side wall portion form a space for accommodating the first head chip, the holder has an outer wall portion connected to the flange portion and surrounding the side wall portion when viewed in the ejection direction, and a connection portion connecting the side wall portion and the outer wall portion, The connection portion extends in a direction intersecting the ejection direction, Each of the side wall portion and the outer wall portion extends from the connection portion in a direction opposite to the jetting direction. A liquid jet head comprising:

3. The flange portion is disposed at a position opposite to the ejection direction from the heat receiving portion. The liquid jet head according to claim 2 .

4. The heat receiving portion has a first surface and a second surface facing in opposite directions, the first surface is a heat-receiving surface that receives heat from the heater, the first head chip has a case in which a liquid flow path is provided, The case is fixed to the second surface and is made of a material having a lower thermal conductivity than the holder.

4. The liquid jet head according to claim 2, wherein the first and second electrodes are arranged in a first direction.

5. a flow path structure disposed in a position opposite to the ejection direction with respect to the holding portion, the flow path structure including a flow path for liquid supplied to the first head chip; the heater is disposed between the holding portion and the flow path structure, The flow path structure is disposed at an interval between the flow path structure and the outer wall portion. The liquid jet head according to claim 2 .

6. When viewed in the ejection direction, an outer circumferential surface of the side wall portion is disposed at a distance from an inner circumferential surface of the outer wall portion over the entire area. The liquid jet head according to claim 2 .

7. The flange portion surrounds the outer wall portion over the entire periphery as viewed in the injection direction. The liquid jet head according to claim 6 .

8. Further comprising a second head chip for ejecting liquid; The holding portion further holds the second head chip. The liquid jet head according to claim 2 .

9. The ink jet head further includes a third head chip and a fourth head chip that eject liquid and are adjacent to each other, the first head chip and the second head chip are adjacent to each other, When two directions that intersect with each other along the nozzle surface are defined as a first direction and a second direction, the first head chip and the second head chip are arranged to be shifted from each other in both the first direction and the second direction, the third head chip and the fourth head chip are arranged to be shifted from each other in both the first direction and the second direction, When viewed in the first direction, one of four sides of a virtual rectangle circumscribing an assembly of the first head chip, the second head chip, the third head chip, and the fourth head chip is defined as a first side, a side connected to one end of the first side is defined as a second side, a side connected to the other end of the first side is defined as a third side, and a side other than the first side, the second side, and the third side is defined as a fourth side, the first head chip is in contact with the first side and the third side when viewed in the first direction; the second head chip is in contact with the second side when viewed in the first direction, the third head chip is in contact with the third side when viewed in the first direction, the fourth head chip is in contact with the second side and the fourth side when viewed in the first direction; a first region surrounded by the first side, the second side, the first head chip, and the second head chip when viewed in the first direction, and a second region surrounded by the third side, the fourth side, the third head chip, and the fourth head chip when viewed in the first direction each include a portion located outside an outer edge of the sidewall portion; The liquid jet head according to claim 8 .

10. The support body is provided with an opening into which the outer wall portion is inserted, The flange portion has a mounting surface facing the ejection direction, The holder is attached to the support in a state in which the outer wall portion is inserted into the opening with a gap between the outer wall portion and the support, and the mounting surface is in contact with the support. The liquid jet head according to claim 2 .

11. A liquid ejection head supported by a support, comprising: a first head chip for ejecting liquid; a holder having a holding portion for holding the first head chip and a flange portion for contacting the support at a position separated from the holding portion; A heater that heats the holding portion, the holding portion has a heat receiving portion that receives heat from the heater, The shortest path for heat to be transmitted through the holder from the heat receiving portion to the flange portion is bent or curved at two or more points, The number of bends or curves in the shortest path is 4 or more. Liquid injection head.

12. In the shortest path of heat transmitted through the holder from the heat receiving portion to the flange portion, a direction of heat transmission in a portion of the holder and a direction of heat transmission in a portion of the holder other than the portion are opposite to each other. The liquid jet head according to claim 1 .

13. the first head chip has a nozzle surface that ejects liquid in an ejection direction; The flange portion is disposed on the outer side of the heat receiving portion when viewed in the jetting direction. The liquid jet head according to claim 1 .

14. A liquid ejection head supported by a support, comprising: a first head chip for ejecting liquid; a holder having a holding portion for holding the first head chip and a flange portion for contacting the support at a position separated from the holding portion; A heater that heats the holding portion, the holding portion has a heat receiving portion that receives heat from the heater, The shortest path for heat to be transmitted through the holder from the heat receiving portion to the flange portion is bent or curved at two or more points, the holder has an upper surface and a lower surface facing in opposite directions, the lower surface directly facing the first head chip, the heater is disposed on an upper surface of the holder, the heat receiving portion is disposed between the first head chip and the heater, The flange portion protrudes outward toward the support. A liquid jet head comprising:

15. The heater and the support are spaced apart from each other.

15. The liquid jet head according to claim 1,

16. The heater is disposed inside the liquid ejection head. The liquid jet head according to claim 1 .

17. the holding section further holds a second head chip that ejects liquid together with the first head chip, the heat receiving portion is disposed between the first head chip and the second head chip and the heater; The liquid jet head according to claim 1 .

18. The liquid jet head according to claim 1 , A support for supporting the liquid ejection head. A liquid ejection apparatus comprising:

Images