Liquid ejecting head and liquid ejecting device

Abstract

The present invention provides a liquid ejection head and a liquid ejection device capable of precisely managing the temperature of a head chip. The liquid ejection head comprises: a plurality of head chips, each having a nozzle face on which nozzles for ejecting liquid are disposed; a thermally conductive holder for retaining the plurality of head chips; a thermally conductive flow channel structure provided with flow channels for supplying liquid to the plurality of head chips; and a planar heater disposed between the holder and the flow channel structure and extending parallel to the nozzle face. The heater overlaps the plurality of head chips when viewed from above.

Description

Technical Field

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

[0002] Liquid ejecting devices such as inkjet printers generally include a liquid ejecting head that ejects liquid such as ink as droplets. The liquid ejecting head may include a heater that heats the liquid, as in the inkjet head described in Patent Document 1.

[0003] The print head described in Patent Document 1 includes a flow channel body with a liquid flow channel; a head body that ejects the liquid from the flow channel body; and two thin-sheet heaters. The flow channel body is interposed between the head body and the heaters, and heat from the heaters is transferred to the head body via the flow channel body.

[0004] In the print head described in Patent Document 1, since the flow path body is interposed between the head body and the heater, the distance between the head body and the heater becomes longer depending on the thickness of the flow path body. Consequently, in the print head described in Patent Document 1, a temperature gradient is likely to develop between the heater and the head body, making it difficult to accurately manage the temperature of the head body.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-76176 Summary of the Invention

[0006] In order to solve the above problems, the liquid injection head involved in the preferred embodiment of the present invention comprises: a plurality of head chips, each of the head chips having a nozzle surface, and a nozzle for spraying liquid is arranged on the nozzle surface; a heat-conductive retainer, which holds the plurality of head chips; a heat-conductive flow channel structure, which is provided with a flow channel for supplying liquid to the plurality of head chips; a planar heater, which is arranged between the retainer and the flow channel structure, and along a direction parallel to the nozzle surface, the heater overlaps with the plurality of head chips when viewed from above.

[0007] A liquid ejecting apparatus according to a preferred embodiment of the present invention includes the liquid ejecting head according to the aforementioned embodiment and a liquid reservoir for storing liquid supplied to the liquid ejecting head. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram showing a configuration example of the liquid ejecting apparatus according to the first embodiment.

[0009] Figure 2 It is a perspective view of the liquid jet head and the support body according to the first embodiment.

[0010] Figure 3 It is an exploded perspective view of the liquid ejecting head according to the first embodiment.

[0011] Figure 4 for Figure 2 AA line section view in.

[0012] Figure 5 for Figure 2 BB line section view in.

[0013] Figure 6 is a cross-sectional view showing an example of a head chip.

[0014] Figure 7 It is a bottom view of the retainer in the first embodiment.

[0015] Figure 8 3 is a top view of the retainer in the first embodiment.

[0016] Figure 9 It is a diagram for explaining the shape of the holding portion of the holder in the first embodiment.

[0017] Figure 10 It is a diagram for explaining the shapes of the heater and the heat transfer member in the first embodiment.

[0018] Figure 11 This is a diagram for explaining a heat transfer path from a heater in the first embodiment.

[0019] Figure 12 It is an exploded perspective view of a liquid ejecting head according to a second embodiment.

[0020] Figure 13 This is a diagram for explaining a heat transfer path from a heater in the third embodiment. DETAILED DESCRIPTION

[0021] Preferred embodiments of the present invention are described below with reference to the accompanying drawings. In the drawings, the dimensions and scales of various components may differ from actual dimensions as appropriate, and some components are shown schematically for ease of understanding. The scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

[0022] For convenience, the following description will be made using the intersecting X-axis, Y-axis, and Z-axis as appropriate. Furthermore, in the following description, a direction along the X-axis is referred to as the X1 direction, and the direction opposite to the X1 direction is referred to as the X2 direction. Similarly, directions opposite to each other along the Y-axis are referred to as the Y1 direction and the Y2 direction. Furthermore, directions opposite to each other along the Z-axis are referred to as the Z1 direction and the Z2 direction. Furthermore, viewing along the Z-axis is sometimes referred to as "viewing from above." Furthermore, the Y-direction or the Y2-direction is an example of a "first direction." The X1-direction or the X2-direction is an example of a "second direction."

[0023] 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 necessarily need to be a vertical axis. Furthermore, while the X axis, Y axis, and Z axis are typically orthogonal to each other, this is not limited to the above. For example, they may intersect at an angle within a range of 80° to 100°.

[0024] 1. First Implementation

[0025] 1-1. Schematic Structure of Liquid Ejecting Device

[0026] Figure 1 This is a schematic diagram showing an example configuration of a liquid ejecting device 100 according to the first embodiment. The liquid ejecting device 100 is an inkjet printing device that ejects ink, an example of "liquid," as droplets onto a medium M. The medium M is typically printing paper. However, the medium M is not limited to printing paper and may be any other printing material, such as a resin film or fabric.

[0027] like Figure 1 As shown, the liquid ejecting apparatus 100 includes a liquid storage portion 10 , a control unit 20 , a transport mechanism 30 , a moving mechanism 40 , and a liquid ejecting head 50 .

[0028] The liquid storage unit 10 is a container for storing ink. Specific examples of the liquid storage unit 10 include a cartridge that can be attached to and detached from the liquid ejecting device 100, an ink bag formed of a flexible film, and an ink tank capable of refilling ink.

[0029] Although not shown, the liquid storage unit 10 includes multiple containers for storing different types of inks. The inks stored in these containers are not particularly limited, but examples thereof include cyan ink, magenta ink, yellow ink, black ink, transparent ink, white ink, and treatment liquid, and combinations of two or more of these can be used. Furthermore, the composition of the inks is not particularly limited; for example, they can be water-based inks in which a colorant such as a dye or pigment is dissolved in an aqueous solvent, solvent-based inks in which a colorant is dissolved in an organic solvent, or UV-curable inks.

[0030] In this embodiment, a configuration using four different inks is exemplified. The four inks are, for example, cyan ink, magenta ink, yellow ink, and black ink, each of different colors.

[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 CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) 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 containing drive pulses that drive the drive elements of the liquid ejection head 50. The control signal S is a signal that specifies whether to supply the drive signal D to the drive elements.

[0032] The transport mechanism 30 transports the medium M in the transport direction DM, which is the Y1 direction, under the control of the control unit 20. The moving mechanism 40 reciprocates the liquid ejecting head 50 in the X1 direction and the X2 direction under the control of the control unit 20. Figure 1 In the example shown, the moving mechanism 40 includes a substantially box-shaped support body 41 called a carriage that accommodates the liquid ejecting head 50, and a conveyor belt 42 that secures the support body 41. Furthermore, the support body 41 may also be equipped with the aforementioned liquid reservoir 10 in addition to the liquid ejecting head 50.

[0033] As described later, the liquid ejecting head 50 includes a plurality of head chips 54. Under the control of the control unit 20, the liquid ejecting head 50 ejects ink supplied from the liquid reservoir 10 from each of the plurality of nozzles of each head chip 54 toward the medium M in the Z2 direction, which is the ejection direction. This ejection is performed in parallel with the transport of the medium M by the transport mechanism 30 and the reciprocating movement of the liquid ejecting head 50 by the movement mechanism 40, thereby forming a predetermined image made of the ink on the surface of the medium M.

[0034] The liquid storage unit 10 may also be connected to the liquid ejecting head 50 via a circulation mechanism. The circulation mechanism supplies ink to the liquid ejecting head 50 and recovers ink discharged from the liquid ejecting head 50 for resupply to the liquid ejecting head 50. The operation of the circulation mechanism can suppress an increase in ink viscosity and reduce the accumulation of bubbles in the ink.

[0035] 1-2. Liquid Ejecting Head Installation

[0036] Figure 2 FIG is a perspective view of the liquid ejecting head 50 and the support body 41 according to the first embodiment. Figure 2 As shown, the liquid ejecting head 50 is supported on the supporting body 41. The supporting body 41 is a component that supports the liquid ejecting head 50. As mentioned above, in the present embodiment, it is a roughly box-shaped slide. Although the constituent material of the supporting body 41 is not particularly limited, it is preferable to use a metal material such as stainless steel, aluminum, titanium or magnesium alloy. In the case where the supporting body 41 is composed of a metal material, it is easy to increase the rigidity of the supporting body 41, so that the liquid ejecting head 50 can be stably supported relative to the supporting body 41. In addition, in this case, since the supporting body 41 is conductive, a reference potential can be supplied to the liquid ejecting head 50 via the supporting body 41.

[0037] Here, the support body 41 is provided with an opening 41a and a plurality of threaded holes 41b. In this embodiment, the support body 41 is roughly box-shaped with a plate-shaped bottom, for example, and the opening 41a and the plurality of threaded holes 41b are provided at the bottom. The liquid ejecting head 50 is inserted into the opening 41a and fixed to the support body 41 by screwing using the plurality of threaded holes 41b. In this manner, the liquid ejecting head 50 is attached to the support body 41.

[0038] exist Figure 2 In the illustrated example, one liquid ejecting head 50 is mounted on the support 41. Alternatively, two or more liquid ejecting heads 50 may be mounted on the support 41. In this case, the support 41 is provided with, for example, openings 41a of a number or shape corresponding to the number of openings.

[0039] 1-3. Structure of Liquid Jet Head

[0040] Figure 3 It is an exploded perspective view of the liquid jet head 50 according to the first embodiment. Figure 4 for Figure 2 AA line section view in. Figure 5 for Figure 2In the BB line section view. Figures 3 to 5 For convenience, the various parts of the liquid ejecting head 50 are appropriately and briefly shown. Figure 11 As shown, a gap of interval d2 is provided between the outer wall portion 5b and the flow channel structure 51, but Figure 4 as well as Figure 5 In the figure, the gap is omitted for the convenience of drawing.

[0041] like Figure 3 As shown, the liquid ejecting head 50 includes a flow channel structure 51, a substrate unit 52, a holder 53, four head chips 54_1 to 54_4, a fixing plate 55, a heater 56, a heat conducting member 57, and a cover 58. These components are arranged such that the cover 58, substrate unit 52, flow channel structure 51, heat conducting member 57, heater 56, holder 53, four head chips 54, and fixing plate 55 are arranged in sequence in the Z2 direction. Below, each component of the liquid ejecting head 50 is described in sequence.

[0042] The heat conducting member 57 is an example of a "second heat conducting member". Figure 1 The head chip 54 shown is shown. 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 distinguished, each of these chips is referred to as a head chip 54.

[0043] The flow channel structure 51 is a structure having a flow channel provided therein for supplying the ink stored in the aforementioned liquid storage portion 10 to the four head chips 54. The flow channel structure 51 includes a flow channel member 51a and eight connecting tubes 51b.

[0044] Although not shown, the flow channel component 51a is provided with four supply channels, one for each of the four ink types, and four discharge channels, one for each of the four ink types. Each of the four supply channels has an inlet for receiving ink and two outlets for discharging ink. Each of the four discharge channels has two inlets for receiving ink and one outlet for discharging ink. The inlet of each supply channel and the outlet of each outlet channel are respectively provided on the surface of the flow channel component 51a facing the Z1 direction. Conversely, the outlet of each supply channel and the inlet of each outlet channel are respectively provided on the surface of the flow channel component 51a facing the Z2 direction.

[0045] In addition, a plurality of wiring holes 51c are provided in the flow channel component 51a. Each of the plurality of wiring holes 51c is a hole through which the wiring substrate 54i, described later, of the head chip 54 passes toward the substrate unit 52. Furthermore, on the side surface of the flow channel component 51a, cutout portions are provided at two locations in the circumferential direction. Within the space formed by these portions, for example, components such as wiring (not shown) that connect the heater 56 to the substrate unit 52 are arranged. Furthermore, a hole (not shown) is provided in the flow channel component 51a, and the retainer 53 is secured thereto by screwing the retainer 53 using the screws provided in the hole.

[0046] Although not shown in the figure, the flow channel component 51a is composed of a laminate in which multiple substrates are laminated in the direction along the Z axis. In each of the multiple substrates, grooves and holes for the aforementioned supply flow channel and exhaust flow channel are appropriately provided. The multiple substrates are joined to each other by, for example, adhesives, brazing, welding or screw fixation. In addition, thin sheet-shaped sealing components made of rubber materials, etc. can be appropriately arranged between the multiple substrates as needed. In addition, the number or thickness of the substrates constituting the flow channel component 51a is determined according to the shape of the supply flow channel and the exhaust flow channel, and is not particularly limited and is arbitrary.

[0047] Each of the plurality of substrates is preferably formed of a material having good thermal conductivity. For example, a metal material such as stainless steel, titanium, or a magnesium alloy, or a ceramic material such as silicon carbide, aluminum nitride, sapphire, aluminum oxide, silicon nitride, cermet, or yttrium oxide, having a thermal conductivity of 10.0 W / m·K or higher at room temperature (20°C) is preferably used. By forming the flow path member 51a from such a metal or ceramic material, the heat from the heater 56 can be used to effectively heat the ink within the flow path member 51a.

[0048] Each of the eight connecting tubes 51b is a tubular body protruding from the surface of the flow channel component 51a facing the Z1 direction. The eight connecting tubes 51b correspond to the four supply flow channels and the four discharge flow channels described above, and are connected to the corresponding supply flow channel inlet or discharge flow channel outlet. The materials constituting each connecting tube 51b are not particularly limited, but are preferably made of metal materials such as stainless steel, titanium, and magnesium alloys, or ceramic materials such as silicon carbide, aluminum nitride, sapphire, aluminum oxide, silicon nitride, cermets, and yttrium oxide.

[0049] Of the eight connecting tubes 51b, the four connecting tubes 51b corresponding to the four supply channels are connected to the liquid reservoir 10 to receive different types of ink. Meanwhile, the four connecting tubes 51b corresponding to the four discharge channels are used to connect to a discharge container for discharging ink at predetermined times, such as during initial filling of the liquid ejecting head 50, or to a sub-tank positioned between the liquid reservoir 10 and the liquid ejecting head 50 and capable of retaining liquid. During normal operation, such as printing, the four connecting tubes 51b corresponding to the four discharge channels are sealed with a sealing member, such as a cap. Furthermore, when the liquid reservoir 10 is connected to the liquid ejecting head 50 via a circulation mechanism, the four connecting tubes 51b corresponding to the four discharge channels are normally connected to the ink recovery channel of the circulation mechanism.

[0050] The substrate unit 52 is a component including mounting parts for electrically connecting the liquid ejecting head 50 and the control unit 20. The substrate unit 52 includes a circuit substrate 52a, a connector 52b, and a support plate 52c.

[0051] The circuit board 52a is a printed wiring board such as a rigid wiring board having wiring for electrically connecting each head chip 54 to the connector 52b. The circuit board 52a is arranged on the flow channel structure 51 via a support plate 52c, and the connector 52b is provided on the surface of the circuit board 52a facing the Z1 direction.

[0052] The connector 52b is a connecting component for electrically connecting the liquid ejecting head 50 and the control unit 20. The support plate 52c is a plate-shaped component used to mount the circuit substrate 52a relative to the flow channel structure 51. The circuit substrate 52a is placed on one surface of the support plate 52c and is secured to the support plate 52c by screws or other means. Furthermore, the other surface of the support plate 52c is in contact with the flow channel structure 51. In this state, the support plate 52c is secured to the flow channel structure 51 by screws or other means.

[0053] Here, the support plate 52c not only supports the circuit substrate 52a as described above, but also ensures electrical insulation between the circuit substrate 52a and the flow channel structure 51 and thermally isolates the heater 56 from the circuit substrate 52a. To properly perform these functions, the supporting plate 52c is preferably made of a material with excellent insulating and thermal insulation properties. Specifically, for example, a resin material such as a modified polyphenylene ether resin such as Zylon, polyphenylene sulfide resin, or polypropylene resin is preferred. Zylon is a registered trademark. Furthermore, the supporting plate 52c may include, in addition to the resin material, a fiber substrate such as glass fiber or a filler such as alumina particles.

[0054] The holder 53 is a structure that houses and supports the four head chips 54. The holder 53 is preferably constructed of a material with good thermal conductivity. For example, metal materials such as stainless steel, titanium, and magnesium alloys, or ceramic materials such as silicon carbide, aluminum nitride, sapphire, aluminum oxide, silicon nitride, cermets, and yttrium oxide, with a thermal conductivity of 10.0 W / m·K or higher at room temperature (20°C), are preferably used. Using such metal or ceramic materials for the holder 53 allows heat from the heater 56 to be efficiently transferred to each head chip 54 via the holder 53.

[0055] The retainer 53 is roughly tray-shaped and includes a recess 53a, multiple ink holes 53b, multiple wiring holes 53c, multiple recesses 53d, multiple threaded holes 53i, and multiple threaded holes 53k. The recess 53a opens in the Z1 direction and is a space for arranging the laminated body of the aforementioned flow channel component 51a, heater 56, and heat conductive component 57. Each of the multiple ink holes 53b is a flow channel that allows ink to flow between the head chip 54 and the flow channel structure 51. Each of the multiple wiring holes 53c is a hole through which the wiring substrate 54i of the head chip 54 passes toward the substrate unit 52. Each of the multiple recesses 53d opens in the Z2 direction and is a space for arranging the head chip 54. The multiple threaded holes 53i are threaded holes for threading the retainer 53 to the support body 41. The multiple threaded holes 53k are threaded holes for threading the cover 58 to the retainer 53. In addition, the details of the retainer 53 will be described later. Figure 7 of Figure 9 And explain.

[0056] Each head chip 54 ejects ink. Each head chip 54 has a plurality of nozzles for ejecting a first ink, and a plurality of nozzles for ejecting a second ink of a type different from the first ink. Here, the first ink and the second ink are two inks among the four inks mentioned above. For example, in each of the head chip 54_1 and the head chip 54_2, two inks among the four inks are used as the first ink and the second ink. Moreover, in each of the head chip 54_3 and the head chip 54_4, the remaining two inks among the four inks are used. In each head chip 54, a wiring substrate 54i is provided. In addition, Figure 3 In FIG. 5 , the structure of each head chip 54 is simplified and illustrated. The structure of the head chip 54 will be described later. Figure 6 And describe in detail.

[0057] The fixing plate 55 is a plate-shaped member to which the four head chips 54 and the holder 53 are fixed. Specifically, the fixing plate 55 is arranged to sandwich the four head chips 54 with the holder 53, and each head chip 54 and the holder 53 are fixed by adhesive or the like.

[0058] The fixing plate 55 is provided with a plurality of openings 55a for exposing the nozzle faces FN of the four head chips 54. Figure 3 In the illustrated example, the plurality of openings 55a are provided independently for each head chip 54. The fixing plate 55 is made of a metal material such as stainless steel, titanium, or a magnesium alloy, and has the function of transferring heat from the holder 53 to each head chip 54. Furthermore, the fixing plate 55 is electrically conductive. Therefore, the fixing plate 55 is grounded via the holder 53 and the support body 41, and also functions as an electrostatic shield to prevent the effects of static electricity, etc., from the medium M. Alternatively, the fixing plate 55 can be constructed by laminating a plurality of plate-like members made of metal materials.

[0059] The outer shape of the above-mentioned fixing plate 55 is rectangular or roughly rectangular when viewed from above. Here, "roughly rectangular" refers to a concept that includes shapes that can be essentially called rectangles and shapes similar to rectangles. A shape that can be essentially called a rectangle is, for example, a shape obtained by chamfering the four corners of a rectangle by 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. In addition, the opening 55a can also be shared by more than two head chips 54. However, in the case where the opening 55a is independently provided 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 effectively transferred from the retainer 53 to each head chip 54.

[0060] The heater 56 is a planar heater arranged between the flow channel structure 51 and the retainer 53. The heater 56 is, for example, a thin film heater having an insulating film and a thin film heating resistor. The film is made of, for example, a resin material such as polyimide or PET (polyethylene terephthalate). The heating resistor is patterned on the film and is made of, for example, a metal material such as stainless steel, copper, or a nickel alloy. In addition, the heater 56 can also be a planar heater such as a silicone rubber heater or a ceramic heater in which a heating element is sandwiched between silicone rubber containing glass fiber.

[0061] A plurality of holes 56a and a plurality of holes 56b are provided in the heater 56. Each of the plurality of holes 56a is a hole through which the wiring substrate 54i of the head chip 54 and the flow channel tube 53l formed in the holder 53 pass. The ink hole 53b formed inside the flow channel tube 53l is a part of the flow channel that allows ink to flow between the head chip 54 and the flow channel structure 51. The flow channel tube 53l protrudes in the Z1 direction from the upper surface of the holder 53 facing the Z1 direction (the first surface F1 described later). Moreover, the ink hole 53b and the flow channel inside the flow channel structure 51 are sealed liquid-tightly by bonding the top end of the flow channel tube 53l on the Z1 direction side to the lower surface of the flow channel structure 51 facing the Z2 direction. Each of the plurality of holes 56b is a hole for threadedly fixing the heater 56 relative to the holder 53. In addition, the shape of the heater 56 when viewed from above will be determined based on the following. Figure 10 , give a detailed description.

[0062] The heat conducting member 57 is a plate-shaped member with thermal conductivity and is positioned between the flow channel structure 51 and the heater 56. The heat conducting member 57 has the 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 channel structure 51 via the heat conducting member 57. The surface-directed heat transfer of the heat conducting member 57 reduces uneven heating of the flow channel structure 51 caused by the heat distribution of the heater 56.

[0063] The heat-conducting member 57 is made of, for example, a metal material or a thermally conductive material such as a ceramic such as silicon carbide, aluminum nitride, sapphire, aluminum oxide, silicon nitride, cermet, or yttrium oxide. Examples of such metal materials include stainless steel, aluminum, titanium, and magnesium alloys. The heat-conducting member 57 is preferably made of a material having a high thermal conductivity relative to the flow channel structure 51 or the retainer 53. The presence of such a high thermal conductivity of the heat-conducting member 57 facilitates the transfer of heat from the heater 56 in a direction parallel to the nozzle face FN. Therefore, the heat from the heater 56 can be uniformly and efficiently transferred to the flow channel structure 51, the object to be heated, via the heat-conducting member 57.

[0064] In the heat-conducting component 57, a plurality of holes 57a, a plurality of wiring holes 57b, and a plurality of holes 57c are provided. Each of the plurality of holes 57a is a hole for the aforementioned flow channel tube 53l to be inserted. Each of the plurality of wiring holes 57b is a hole for the wiring substrate 54i of the head chip 54 to pass toward the substrate unit 52. The plurality of holes 57c are holes for threading the heat-conducting component 57 relative to the retainer 53. In this embodiment, two holes 57c of the plurality of holes 57c are used to fix the heater 56 and the heat-conducting component 57 to the retainer 53 by tightening them together. In addition, regarding the shape of the heat-conducting component 57 when viewed from above, the shape will be determined based on the following description. Figure 10 , give a detailed description.

[0065] The cover 58 is a box-shaped member that accommodates the substrate unit 52. The cover 58 is made of a resin material such as modified polyphenylene ether resin, polyphenylene sulfide resin, or polypropylene resin, similarly to the support plate 52c described above.

[0066] The cover 58 is provided with eight through-holes 58a and an opening 58b. The eight through-holes 58a correspond to the eight connecting tubes 51b of the flow channel structure 51, and a corresponding connecting tube 51b is inserted into each through-hole 58a. The aforementioned connector 52b is inserted into the opening 58b from the inside of the cover 58 to the outside.

[0067] 1-4. Head Chip Structure

[0068] Figure 6 FIG is a cross-sectional view showing an example of the head chip 54. Figure 6 As shown, 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, which are arranged side by side with a gap therebetween in the direction along the X axis. The first row L1 and the second row L2 are each a set of the plurality of nozzles N arranged in a straight line in the direction along the Y axis.

[0069] The head chips 54 are substantially symmetrical in the direction along the X-axis. However, the positions of the plurality of nozzles N in the first column L1 and the plurality of nozzles N in the second column L2 along the Y-axis may be identical or different. Figure 6 In FIG. 1 , a structure is illustrated in which the positions of the plurality of nozzles N in the first row L1 and the plurality of nozzles N in the second row L2 along the Y-axis direction coincide with each other.

[0070] like Figure 6 As shown, the head chip 54 includes 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 protection plate 54g, a housing 54h, a wiring substrate 54i, and a drive circuit 54j.

[0071] The flow path substrate 54a and the pressure chamber substrate 54b are laminated in sequence in the Z1 direction to form a flow path for supplying ink to a plurality of nozzles N. In an area located closer to the Z1 direction than the laminate composed of the flow path substrate 54a and the pressure chamber substrate 54b, a vibration plate 54e, a plurality of piezoelectric elements 54f, a protective plate 54g, a housing 54h, a wiring substrate 54i, and a drive circuit 54j are provided. On the other hand, in an area located closer to the Z2 direction than the laminate, a nozzle plate 54c and a vibration absorber 54d are provided. The various elements of the head chip 54 are plate-like components that are roughly elongated in the Y direction and are bonded to each other by, for example, an adhesive. Below, the various elements of the head chip 54 are described in sequence.

[0072] The nozzle plate 54c is a plate-shaped component provided with a plurality of nozzles N in each of the first column L1 and the second column L2. Each of the plurality of nozzles N is a through hole for 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 ejection direction, i.e., the Z2 direction. The nozzle plate 54c is manufactured, for example, by processing a single crystal silicon substrate using semiconductor manufacturing technology such as dry etching or wet etching. However, in the manufacture of the nozzle plate 54c, other well-known methods and materials may also be appropriately used. In addition, although the cross-sectional shape of the nozzle is typically circular, it is not limited to this. For example, it may also be a non-circular shape such as a polygon or an ellipse.

[0073] The flow channel substrate 54a is provided with a space R1, multiple supply flow channels Ra, and multiple communication flow channels Na for each of the first and second rows L1 and L2. Space R1 is an elongated opening extending along the Y axis when viewed from above along the Z axis. The supply flow channels Ra and communication flow channels Na are through-holes formed for each nozzle N. Each supply flow channel Ra communicates with space R1.

[0074] The pressure chamber substrate 54b is a plate-shaped component with a plurality of pressure chambers C, referred to as cavities, provided for each of the first and second rows L1 and L2. The plurality of pressure chambers C are arranged along the Y-axis. Each pressure chamber C is formed for each nozzle N and is a long, strip-shaped space extending along the X-axis when viewed from above. The flow path substrate 54a and the pressure chamber substrate 54b are each manufactured, similar to the aforementioned nozzle plate 54c, by processing a single crystal silicon substrate using semiconductor manufacturing technology, for example. However, other known methods and materials may be used, as appropriate, in the manufacture of the flow path substrate 54a and the pressure chamber substrate 54b.

[0075] The pressure chamber C is located between the flow channel substrate 54a and the vibration plate 54e. Multiple pressure chambers C are arranged along the Y-axis for each of the first row L1 and the second row L2. Furthermore, the pressure chambers C are connected to the communication channel Na and the supply channel Ra, respectively. Therefore, the pressure chambers C communicate with the nozzle N via the communication channel Na and with the space R1 via the supply channel Ra.

[0076] A vibration plate 54e is arranged on the surface of the pressure chamber substrate 54b facing the Z1 direction. The vibration plate 54e is a plate-shaped component that can vibrate elastically. The vibration plate 54e has, for example, a first layer and a second layer, and these layers are laminated in sequence in the Z1 direction. The first layer is, for example, an elastic film composed of silicon oxide (SiO2). The elastic film is formed, for example, by thermally oxidizing one surface of a single crystal silicon substrate. The second layer is, for example, an insulating film composed of zirconium oxide (ZrO2). The insulating film is formed, for example, by forming a zirconium layer by sputtering and thermally oxidizing the layer. In addition, the vibration plate 54e is not limited to a structure formed by laminating the aforementioned first layer and second layer. For example, it can be composed of a single layer or three or more layers.

[0077] On the surface of the vibration plate 54e facing the Z1 direction, multiple piezoelectric elements 54f corresponding to the nozzles N are arranged as driving elements in each of the first column L1 and the second column L2. Each piezoelectric element 54f is a passive element that deforms in response to a driving signal. When viewed from above, each piezoelectric element 54f has a long, strip-like shape extending along the X-axis. The multiple piezoelectric elements 54f are arranged along the Y-axis to correspond to the multiple pressure chambers C. When viewed from above, the piezoelectric elements 54f overlap with the pressure chambers C.

[0078] Although not shown, each piezoelectric element 54f has a first electrode, a piezoelectric layer, and a second electrode, which are stacked sequentially in the Z1 direction. One of the first and second electrodes is an independent electrode configured separately for each piezoelectric element 54f, and a drive signal is applied to this electrode. The other of the first and second electrodes is a common electrode in the form of a strip extending continuously along the Y-axis across multiple piezoelectric elements 54f, and a predetermined reference potential is supplied to this electrode. Examples of metal materials for these electrodes include platinum (Pt), aluminum (Al), nickel (Ni), gold (Au), and copper (Cu), and any of these can be used alone or in combination of two or more 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 is, for example, in the form of a strip extending continuously along the Y-axis across multiple piezoelectric elements 54f. However, the piezoelectric layer may also be formed integrally across multiple piezoelectric elements 54f. In this case, a through-hole extending along the X-axis is provided in the piezoelectric layer in an area corresponding to the gap between adjacent pressure chambers C when viewed from above. When the vibration plate 54e vibrates in conjunction with the deformation of the piezoelectric elements 54f, the pressure within the pressure chambers C fluctuates, causing ink to be ejected from the nozzles N. Alternatively, a heating element that heats the ink within the pressure chambers C may be used as a driving element in place of the piezoelectric elements 54f.

[0079] The protective plate 54g is a plate-shaped member installed on the surface of the vibration plate 54e facing the Z1 direction. It 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.

[0080] The housing 54h is used to store ink supplied to the multiple pressure chambers C. The housing 54h is made of, for example, a resin material. A space R2 is provided in the housing 54h for each of the first and second columns L1 and L2. The space R2 communicates with the aforementioned space R1 and, together with the space R1, functions as a reservoir R for storing ink supplied to the multiple pressure chambers C. The housing 54h is provided with an inlet 10 for supplying ink to each reservoir R. The ink in each reservoir R is supplied to the pressure chambers C via the supply flow channels Ra.

[0081] The vibration absorbing body 54d is also called a plastic substrate, and is a flexible resin film constituting the wall surface of the liquid reservoir R, and absorbs the pressure fluctuation of the ink in the liquid reservoir R. In addition, the vibration absorbing body 54d may also be a thin flexible plate made of metal. The surface of the vibration absorbing body 54d facing the Z1 direction is bonded to the flow channel substrate 54a by an adhesive or the like. On the other hand, a frame 54k is bonded to the surface of the vibration absorbing body 54d facing the Z2 direction by an adhesive or the like. The frame 54k is a frame-shaped component along the outer periphery of the vibration absorbing body 54d, and is in contact with the aforementioned fixing plate 55. Here, the frame 54k is made of a metal material such as stainless steel, aluminum, titanium, and magnesium alloy. By constituting the frame 54k with a metal material in this way, the heat from the heater 56 can be appropriately transferred to the ink in the head chip 54 via the retainer 53 and the fixing plate 55. In addition, in Figure 6 In the figure, the dotted arrows schematically indicate the heat transfer path H1 from the heater 56 to the head chip 54. Although a portion of the transfer path H1 includes a vibration absorber 54d made of a resin material with relatively low thermal conductivity, the vibration absorber 54d is formed in a thin film for flexibility, resulting in a relatively low thermal resistance. Therefore, the vibration absorber 54d has minimal effect on the heat transfer from the frame 54k to the flow path substrate 54a.

[0082] The wiring substrate 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 to the head chip 54. The wiring substrate 54i is, for example, a flexible wiring substrate such as a COF (Chip On Film), an FPC (Flexible Printed Circuit), or an FFC (Flexible Flat Cable). In this embodiment, a drive circuit 54j is mounted on the wiring substrate 54i for supplying a drive voltage to each piezoelectric element 54f. The drive circuit 54j is a circuit that switches, based on a control signal S, whether or not to supply at least a portion of the waveform included in the drive signal D as a drive pulse.

[0083] 1-5. Structure of the retainer

[0084] Figure 7 This is a bottom view of the retainer 53 in the first embodiment as viewed in the Z1 direction. Figure 8 FIG2 is a top view of the retainer 53 in the first embodiment as viewed in the Z2 direction. Figure 7 as well as Figure 8 As shown, the holder 53 having a substantially tray shape as described above has a bottom portion 5a, an outer wall portion 5b and a flange portion 5c.

[0085] The bottom portion 5a is generally plate-shaped and extends in a direction perpendicular to the Z-axis, and forms the bottom surface of the aforementioned recessed portion 53a. The bottom portion 5a is divided into a retaining portion 5a1 and a connecting portion 5a2. The connecting portion 5a2 is arranged so as to surround the outer periphery of the retaining portion 5a1 and is thinner than the retaining portion 5a1.

[0086] The holding portion 5a1 has the aforementioned four recesses 53d and holds the four head chips 54. Each head chip 54 is accommodated in a space surrounded by each recess 53d and the fixing plate 55. Figure 7 As shown, in addition to the four recesses 53d, the retaining portion 5a1 also has two recesses 53h. Each recess 53h is a so-called recess for reducing wall thickness and is located between the four recesses 53d. It has the same depth as the recesses 53d. The retaining portion 5a1 includes a heat receiving portion 5a11 and a side wall portion 5a12.

[0087] The heat receiving portion 5a11 is plate-shaped and has a first surface F1 and a second surface F2 extending in a direction perpendicular to the Z axis. These surfaces form the bottom surfaces of the recesses 53d and 53h. The first surface F1 faces the Z1 direction and receives heat from the heater 56. The flow channel structure 51 is placed on the first surface F1 via the heater 56 and the heat conducting member 57. The second surface F2 faces the Z2 direction and forms the bottom surfaces of the recesses 53d and 53h.

[0088] exist Figure 7 as well as Figure 8 In the illustrated example, the heat receiving portion 5a11 includes a plurality of ink holes 53b and a plurality of wiring holes 53c, each opening on the first surface F1 and the second surface F2. In addition to these openings, the first surface F1 of the heat receiving portion 5a11 also includes a plurality of holes 53e, a plurality of holes 53f, and a plurality of threaded holes 53g.

[0089] The plurality of holes 53e are holes used to position the head chip 54 relative to the holder 53 by inserting protrusions (not shown) provided on the head chip 54. The plurality of holes 53f are holes for inserting positioning pins used to position the flow channel structure 51, the heater 56, and the heat conducting member 57. The plurality of threaded holes 53g are threaded holes used to screw the heat conducting member 57. The plurality of threaded holes 53g are threaded holes used to screw the flow channel structure 51.

[0090] The side wall portion 5a12 protrudes from the heat receiving portion 5a11 in the Z2 direction and forms 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, when viewed along the Z-axis, the shape of the side wall portion 5a12 is the shape obtained by removing the shapes of the multiple recesses 53d and the multiple recesses 53h from the shape of the heat receiving portion 5a11. In other words, when viewed along the Z-axis, the side wall portion 5a12 includes partitions between adjacent multiple recesses 53d, partitions between adjacent recesses 53d and recesses 53h, and an outer peripheral wall surrounding the multiple recesses 53d and the multiple recesses 53h.

[0091] The connecting portion 5a2 is arranged so as to surround the retaining portion 5a1 when viewed along the Z-axis. The connecting portion 5a2 is in the shape 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 across the entire circumference. Furthermore, the connecting portion 5a2 may have a shape with a missing portion or may be composed of multiple portions arranged side by side at intervals in the circumferential direction.

[0092] The outer wall portion 5b has a frame shape extending from the peripheral edge of the bottom portion 5a over the entire circumference in the Z1 direction, and constitutes a side surface of the aforementioned recessed portion 53a.

[0093] The flange portion 5c is in the shape of a plate that projects outward from the end of the outer wall portion 5b in the Z1 direction and in a direction perpendicular to the Z axis. Thus, the outer peripheral edge of the connecting portion 5a2 of the bottom portion 5a is connected to the inner peripheral edge of the flange portion 5c via the outer wall portion 5b. Figure 7 as well as Figure 8 In the example shown, the flange portion 5c is rectangular or substantially rectangular when viewed from above. Therefore, the outer shape of the retainer 53 when viewed from above is rectangular or substantially rectangular. In addition to the aforementioned multiple threaded holes 53i and multiple threaded holes 53k, the flange portion 5c also has multiple holes 53j. These holes 53j are used to position the retainer 53 relative to the support body 41 by inserting protrusions (not shown) provided on the support body 41.

[0094] 1-6. Shape of the Retainer's Retaining Portion

[0095] Figure 9 1 is a diagram for explaining the shape of the holding portion 5a1 of the holder 53 in the first embodiment. Figure 9 In FIG. 1 , for convenience of explanation, the outer shapes of the holding portion 5 a 1 and the plurality of head chips 54 as viewed in the Z2 direction are indicated by solid lines.

[0096] like Figure 9As shown, when viewed from above along the Z-axis, the outer edge OE1 of the retaining portion 5a1 has a shape corresponding to the arrangement of the head chips 54_1, 54_2, 54_3, and 54_4. Specifically, when viewed from above, the outer edge OE1 has a shape that resembles a pair of opposing corners of a rectangle and their surrounding areas cut into a roughly rectangular shape. The following describes in detail the arrangement of the head chips 54_1, 54_2, 54_3, and 54_4 and the shape of the outer edge OE1 of the retaining portion 5a1 when viewed from above.

[0097] like Figure 9 As shown, the head chips 54_1, 54_2, 54_3, and 54_4 are arranged alternately in a plan view. The head chips 54_1 and 54_2 are adjacent to each other, the head chips 54_2 and 54_3 are adjacent to each other, and the head chips 54_3 and 54_4 are adjacent to each other.

[0098] Specifically, the head chip 54_1, the head chip 54_2, the head chip 54_3, and the head chip 54_4 are arranged side by side in the X1 direction. However, the head chip 54_1 and the head chip 54_3 are arranged at positions that are offset in the Y1 direction relative to the head chip 54_2 and the head chip 54_4. Here, the head chip 54_1 and the head chip 54_3 are arranged side by side in the direction along the X-axis so that their positions along the Y-axis are aligned. Similarly, the head chip 54_2 and the head chip 54_4 are arranged side by side in the direction along the X-axis so that their positions along the Y-axis are aligned. In addition, the shape of each head chip 54 when viewed from above is a rectangle or a roughly rectangular shape extending in the direction along the Y-axis.

[0099] exist Figure 9 In FIG, when viewed from above, a double-dashed line indicates an imaginary rectangle VS that is inscribed on the aggregate of the head chips 54_1, 54_2, 54_3, and 54_4 configured as described above. The rectangle VS is the smallest rectangle that contains the aggregate when viewed from above. In addition, in this embodiment, each of the multiple head chips 54_1, 54_2, 54_3, and 54_4 is in contact with the imaginary rectangle VS. Figure 9 In the example shown, the aggregate has a quadratically symmetrical shape when viewed from above.

[0100] The outer edge OE1 of the holding portion 5a1 has a portion located inside and outside the rectangle VS.

[0101] Here, if the four sides of the rectangle VS are defined as the first side E1, the second side E2, the third side E3, and the fourth side E4, the head chip 54_1 is in contact with the first side E1 and the third side E3 when viewed from above. The head chip 54_2 is in contact with the second side E2 when viewed from above. The head chip 54_3 is in contact with the third side E3 when viewed from above. The head chip 54_4 is in contact with the second side E2 and the fourth side E4 when viewed from above.

[0102] The first side E1 is one of the four sides of the rectangle VS. The second side E2 is the side of the rectangle VS that is connected to one end of the first side E1. The third side E3 is the side of the rectangle VS that is connected to the other end of the first side E1. The fourth side E4 is the side of the rectangle VS other than the first side E1, the second side E2, and the third side E3.

[0103] When viewed from above, the first region RE1, which is surrounded by the first side E1, the second side E2, the head chip 54_1, and the head chip 54_2, is divided into a first inner portion RE1a and a first outer portion RE1b by the outer edge OE1. The first inner portion RE1a is the portion of the first region RE1 located inward of the outer edge OE1. The first outer portion RE1b is the portion of the first region RE1 located outward of the outer edge OE1. Furthermore, when viewed from above, the first region RE1 is a rectangular region surrounded by the first side E1, the second side E2, a straight line along the shorter of the two short sides of the head chip 54_1, whichever is closer to the head chip 54_2, and a straight line along the longer of the two long sides of the head chip 54_2, whichever is closer to the head chip 54_1.

[0104] Here, the first side E1 includes a first portion PA1 that defines the first region RE1. The first portion PA1 is the portion of the four sides of the rectangular first region RE1 that belongs to the first side E1. The second side E2 includes a second portion PA2 that defines the first region RE1. The second portion PA2 is the portion of the four sides of the rectangular first region RE1 that belongs to the second side E2. Furthermore, when viewed from above, the outer edge OE1 of the retaining portion 5a1 intersects both the first portion PA1 and the second portion PA2.

[0105] Furthermore, when viewed from above, the intersection IPa of the outer edge OE1 of the holding portion 5a1 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 IPb of the outer edge OE1 of the holding portion 5a1 and the second portion PA2 is located closer to the head chip 54_2 than the midpoint MP2 of the second portion PA2. Figure 9 In the example shown, the intersection point IPb is located very close to the midpoint MP2 but is located in the X1 direction relative to the midpoint MP2.

[0106] 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. Figure 9 In the example shown, although the center CP is located very close to the outer edge OE1 , it is located outside the outer edge OE1 .

[0107] Similar to the first region RE1 described above, the second region RE2, surrounded by the third side E3, the fourth side E4, the head chip 54_3, and the head chip 54_4, is divided into a second inner portion RE2a and a second outer portion RE2b by the outer edge OE1 when viewed from above. The second inner portion RE2a is located inward of the outer edge OE1. The second outer portion RE2b is located outward of the outer edge OE1. Furthermore, when viewed from above, 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 head chip 54_3 (closer to the head chip 54_4), and a straight line along the shorter side of the head chip 54_4 (closer to the head chip 54_3).

[0108] 1-7. Heater shape

[0109] Figure 10 1 is a diagram for explaining the shapes of the heater 56 and the heat conducting member 57 in the first embodiment. Figure 10 In FIG. 1 , for the sake of convenience, the outer shapes of the heater 56 and the plurality of head chips 54 as viewed in the Z2 direction are indicated by solid lines. Figure 10 In FIG, the outer shape of the flow channel structure 51 or the heat conducting member 57 viewed in the Z2 direction is indicated by a dotted line.

[0110] like Figure 10 As shown, when viewed from above 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. Figure 8 As shown, outer edge OE2 has roughly the same shape as outer edge OE1 of retaining portion 5a1 described above. In other words, outer edge OE2 can be said to be shaped along outer edge OE1. The plan view shape of outer edge OE2 of heater 56 will be described in detail below.

[0111] exist Figure 10 The virtual rectangle VS is shown by a two-dot chain line in FIG. The outer edge OE2 of the heater 56 has a portion located inside and outside the rectangle VS, similarly to the outer edge OE1 of the holding portion 5a1 described above.

[0112] When viewed from above, 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 the portion of the first region RE1 located inward of the outer edge OE2. The first outer portion RE1d is the portion of the first region RE1 located outward of the outer edge OE2. In this embodiment, as described above, the outer edge OE2 is substantially the same shape as the outer edge OE1 of the retaining portion 5a1. Therefore, the first inner portion RE1c is substantially equal to the first inner portion RE1a, and the first outer portion RE1d is substantially equal to the first outer portion RE1b.

[0113] Here, when viewed from above, the outer edge OE2 of the heater 56 contains multiple head chips 54 and intersects both the first portion PA1 and the second portion PA2. In addition, when viewed from above, the intersection IPc of 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 of 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. Figure 10 In the example shown, although the intersection point IPd is located very close to the midpoint MP2, it is located in the X1 direction relative to the midpoint MP2.

[0114] 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. Figure 10 In the example shown, although the center CP is located very close to the outer edge OE2, it is located outside the outer edge OE2.

[0115] Similar to 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 when viewed from above. The second inner portion RE2c is located inward of the outer edge OE2. The second outer portion RE2d is located outward of 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.

[0116] In contrast, Figure 10The heat conducting member 57 indicated by the dotted line in FIG not only includes the head chips 54_1, 54_2, 54_3, and 54_4 when viewed from above, but also overlaps at least a portion of each of the first outer portion RE1d and the second outer portion RE2d. Similarly, although not shown in the figure, the heat conducting member 57 is overlapped with the aforementioned heat conducting member 57 when viewed from above. Figure 9 The first outer portion RE1b and the second outer portion RE2b are shown so that at least a portion thereof overlaps.

[0117] Here, the shape of the heat conducting member 57 when viewed from above is substantially the same as the shape of the flow channel structure 51 when viewed from above. Therefore, when viewed from above, the flow channel 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 the figure, the flow channel structure 51 when viewed from above is similar to the shape of the heat conducting member 57 when viewed from above. Figure 9 The first outer portion RE1b and the second outer portion RE2b are shown so that at least a portion thereof overlaps.

[0118] 1-8. Heat transfer path from the heater

[0119] Figure 11 1 is a diagram for explaining the heat transfer path H1 and the heat transfer path H2 from the heater 56 in the first embodiment. Figure 11 , each of the transmission path H1 and the transmission path H2 is schematically shown by a dotted line.

[0120] As described above, the support body 41 is provided with an opening 41a into which the outer wall portion 5b is inserted. Meanwhile, the flange portion 5c has a mounting surface 5c1 oriented in the Z2 direction, which is the normal direction to the nozzle face FN. The retainer 53 is mounted on the support body 41 by inserting the outer wall portion 5b into the opening 41a with a gap d1 between them, and placing the mounting surface 5c1 in contact with the support body 41.

[0121] As described above, the heater 56 transfers heat to each head chip 54 along the transfer path H1 , thereby heating each head chip 54 .

[0122] However, part of the heat from the heater 56 is transferred to the support body 41 via the holder 53. In other words, part of the heat from the heater 56 is not used to heat the head chips 54, but escapes to the support body 41 via the holder 53. This heat escape not only reduces the heating efficiency of the head chips 54 by the heater 56 but also causes variations in temperature distribution within or between the head chips 54.

[0123] Therefore, in order to reduce such heat escape, the retainer 53 has a structure that increases the thermal resistance of the heat transfer path H2 from the heater 56 to the support body 41. Specifically, in the retainer 53, as described above, the heat receiving portion 5a11 and the flange portion 5c are connected via the side wall portion 5a12, the connecting portion 5a2, and the outer wall portion 5b.

[0124] The transfer path H2 is a path that transfers heat in the order of the heat receiving portion 5a11, the side wall portion 5a12, the connecting portion 5a2, the outer wall portion 5b, and the flange portion 5c. As described above, the side wall portion 5a12 and the outer wall portion 5b extend in the direction along the Z axis, while the connecting portion 5a2 and the flange portion 5c extend in the direction intersecting the Z axis. Therefore, the transfer path H2 is formed in the order of Figure 11 When viewed from the cross section shown in FIG. 5 , the heat receiving portion 5a11 to the flange portion 5c is bent or curved at least at two locations. Figure 11 In FIG. 1 , two places where the transmission path H2 bends or curves are shown by areas surrounded by two-dot chain lines.

[0125] Here, the outer circumference of the side wall portion 5a12 is arranged so as to be spaced apart from the inner circumference of the outer wall portion 5b by a distance d3 across the entire area. Therefore, heat transfer from the side wall portion 5a12 to the outer wall portion 5b occurs not directly between them but via the connecting portion 5a2. Furthermore, the flow channel structure 51 is arranged so as to be spaced apart from the outer wall portion 5b by a distance d2. Therefore, heat transfer from the heat receiving portion 5a11 to the outer wall portion 5b does not occur through the flow channel structure 51.

[0126] As described above, the liquid jet head 50 includes a plurality of head chips 54, a thermally conductive holder 53, a thermally conductive flow channel structure 51, and a planar heater 56. The plurality of head chips 54 each have a nozzle face FN provided with nozzles N for ejecting ink, an example of "liquid." The holder 53 holds the plurality of head chips 54. The flow channel structure 51 includes a flow channel for supplying ink to the plurality of head chips 54. The heater 56 is arranged between the holder 53 and the flow channel structure 51 and extends parallel to the nozzle face FN. The heater 56 overlaps with the plurality of head chips 54 when viewed from above.

[0127] In the above liquid jet head 50, the heater 56 is arranged between the retainer 53 and the flow channel structure 51. Therefore, compared with the existing structure in which the flow channel structure 51 is interposed between the heater 56 and the retainer 53, the heat from the heater 56 can be effectively transferred to the retainer 53 and the flow channel structure 51 respectively. As a result, the temperature difference between the retainer 53 and the flow channel structure 51 can be reduced, and further, the temperature difference between the head chip 54 and the flow channel structure 51 can be reduced. In addition, the heater 56 is in the form of a surface parallel to the nozzle surface, and on this basis, the heater 56 overlaps with the multiple head chips 54 when viewed from above. Therefore, compared with a structure in which the heater 56 overlaps only a portion of the multiple head chips 54 when viewed from above, the heat from the heater 56 can be effectively transferred to each of the multiple head chips 54. As a result, the temperature difference between the multiple head chips 54 can also be reduced. Based on the above, the temperature of the head chip 54 can be managed with high precision by controlling the temperature of the heater 56.

[0128] In this embodiment, as described above, the holder 53 includes a holding portion 5a1 for holding a plurality of head chips 54. The holding portion 5a1 encompasses the plurality of head chips 54 when viewed from above. Therefore, heat from the heater 56 can be transferred to the plurality of head chips 54 via the single holding portion 5a1. As a result, it is not necessary to provide a heater 56 for each head chip 54, making installation of the heater 56 easier.

[0129] On this basis, each of the multiple head chips 54 is elongated along the Y-axis. Furthermore, the multiple head chips 54 include a head chip 54_1, an example of a "first head chip," and a head chip 54_2, an example of a "second head chip." The head chips 54_1 and 54_2 are adjacent to each other. Here, "adjacent head chips" refers to the positional relationship between the multiple head chips 54. Structures other than the head chips 54 (for example, the sidewall portion 5a12 of the retainer 53 in this embodiment) may be interposed between the multiple head chips 54. Furthermore, the head chip 54_1 and the head chip 54_3 are arranged at positions offset from each other along the X-axis but identical along the Y-axis, with the Y1-direction end of the head chip 54_2 interposed between them. However, the head chips 54_1 and 54_3 are positioned opposite each other along the X-axis, with a dimension greater than or equal to half the dimension of the head chip 54 along the Y-axis. Therefore, it can be said that the head chip 54_1 and the head chip 54_3 are also adjacent to each other. Furthermore, the head chip 54_1 and the head chip 54_2 are arranged so as to be offset from each other in both the direction along the Y-axis and the direction along the X-axis. Furthermore, when two directions intersecting along the nozzle plane FN are defined as the first direction and the 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."

[0130] Here, the head chip 54_1 is in contact with the first side E1 and the third side E3 of the imaginary rectangle VS when viewed from above, and the head chip 54_2 is in contact with the second side E2 when viewed from above. Furthermore, the first region RE1 surrounded by the first side E1, the second side E2, the head chips 54_1, and the head chips 54_2 when viewed from above includes a first outer portion RE1b located outward of the outer edge OE1 of the retaining portion 5a1. The outer edge OE1 is the outer edge of the sidewall portion 5a12 when viewed from above.

[0131] As described above, the rectangle VS is in contact with the assembly of the plurality of head chips 54 included in the liquid ejecting head 50 when viewed from above. 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.

[0132] Neither the retaining portion 5a1 nor the head chip 54 exists in the first outer portion RE1b. Therefore, the presence of this first outer portion RE1b reduces the amount of unused portions of the retaining portion 5a1 other than those intended for heating. This reduces the amount of heat from the heater 56 escaping into these unused portions, allowing the heater 56 to effectively heat the head chip 54. This also offers the advantage of reducing the size of the heater 56 and reducing power consumption.

[0133] As described above, the holder 53 is provided with a plurality of ink holes 53b, which constitute flow paths for ink supplied to the plurality of head chips 54. Therefore, from the perspective of improving the resistance of the holder 53 to ink or efficiently transferring heat from the heater 56 to the ink in the ink holes 53b via the holder 53, the holder 53 is preferably made of stainless steel or ceramic.

[0134] Furthermore, in a plan view, the first region RE1 includes a first outer portion RE1d that does not overlap with the heater 56. Therefore, the area of the heater 56 can be reduced. Since the head chip 54_1 and the head chip 54_2 are not present in the first outer portion RE1d, wasteful heat generation by the heater 56 can be reduced. As a result, the heater 56 can effectively heat the head chip 54.

[0135] Moreover, as mentioned above, the liquid jet head 50 also includes a heat-conducting component 57 as an example of a "second heat-conducting component". The heat-conducting component 57 is a component that is arranged between the heater 56 and the flow channel structure 51 and has a higher thermal conductivity than the flow channel structure 51, for example, aluminum. Moreover, when viewed from above, the heat-conducting component 57 and the flow channel structure 51 overlap with the first outer portion RE1b respectively. The presence of the flow channel structure 51 in the first outer portion RE1b can increase the degree of freedom of distribution of the flow channel in the flow channel structure 51. In addition, since the heat-conducting component 57 is arranged between the heater 56 and the flow channel structure 51, the heat from the heater 56 can be transferred to the flow channel structure 51 after being expanded in the surface direction through the second heat-conducting component. In particular, even if the flow channel structure 51 is located in a portion of the first outer portion RE1b, the heat transfer member 57 is also located in the first outer portion RE1b. Therefore, heat from the heater 56 can be transferred to this portion via the heat transfer member 57. As a result, the deviation in the temperature distribution of the flow channel structure 51 caused by the heater 56 can be reduced.

[0136] Furthermore, as described above, from the perspective of improving the resistance of the flow channel structure 51 to ink or efficiently transferring heat from the heater 56 to the ink in the flow channel structure 51 , the flow channel structure 51 is preferably made of stainless steel or ceramics.

[0137] In this embodiment, the plurality of head chips 54 include a head chip 54_3 as an example of a "third head chip" and a head chip 54_4 as an example of a "fourth head chip." The head chip 54_3 and the head chip 54_4 are arranged so as to be offset from each other in both the direction along the Y axis and the direction along the X axis.

[0138] Here, assuming that the fourth side E4 is the side other than the first side E1, the second side E2, and the third side E3 of the four sides of the imaginary rectangle VS, the head chip 54_3 is in contact with the third side E3 when viewed from above, and the head chip 54_4 is in contact with the second side E2 and the fourth side E4 when viewed from above. Furthermore, the second region RE2 surrounded by the third side E3, the fourth side E4, the head chip 54_3, and the head chip 54_4 when viewed from above includes a second outer portion RE2b located outside the outer edge OE1 of the retaining portion 5a1.

[0139] In the second outer portion RE2b, similar to the first outer portion RE1b, neither the retaining portion 5a1 nor the head chip 54 is present. Therefore, the presence of this second outer portion RE2b reduces the amount of unused portions of the retaining portion 5a1 other than those intended for heating. This reduces the amount of heat from the heater 56 that escapes into these unused portions, allowing the heater 56 to effectively heat the head chip 54. This also offers the advantage of reducing the size of the heater 56 and reducing power consumption.

[0140] The area of the first outer portion RE1b is preferably at least one-quarter the area of the first region RE1, more preferably at least one-half and no more than nine-tenths the area of the first region RE1. When the area of the first outer portion RE1b falls within this range, the previously mentioned unused portion of the retaining portion 5a1 can be reduced. In contrast, if the area of the first outer portion RE1b is too small, the power consumption of the heater 56 increases, or the temperature distribution within each head chip 54 or between multiple head chips 54 tends to vary. On the other hand, if the area of the first outer portion RE1b is too large, it becomes difficult to ensure the required thickness of the retaining portion 5a1. Similarly to the relationship between the area of the first outer portion RE1b and the first region RE1, the area of the second outer portion RE2b is preferably at least one-quarter the area of the second region RE2.

[0141] As described above, the heater 56 overlaps with the plurality of head chips 54 in a plan view. Furthermore, the first region RE1 includes a first outer portion RE1d located outside the outer edge OE2 of the heater 56 in a plan view.

[0142] Neither the heater 56 nor the head chip 54 exists in the first outer portion RE1d. Therefore, the presence of this first outer portion RE1d reduces unnecessary portions of the heater 56. Consequently, variations in temperature distribution within each head chip 54 or between multiple head chips 54 caused by heat generated in this unnecessary portion can be reduced. This also offers the advantage of reducing the area of the heater 56 and reducing power consumption.

[0143] Here, when viewed from above, the aforementioned heat-conducting component 57 and the flow channel structure 51 respectively overlap with the first outer portion RE1d. The presence of the flow channel structure 51 in the first outer portion RE1d allows for greater freedom in the distribution of the flow channels within the flow channel structure 51. Furthermore, even if there is a portion within the first outer portion RE1d where the flow channel structure 51 is present, the presence of the heat-conducting component 57 in the first outer portion RE1d allows heat from the heater 56 to be transferred to that portion via the heat-conducting component 57. As a result, it is possible to reduce deviations in the temperature distribution of the flow channel structure 51 caused by the heater 56. This is particularly useful in a structure where a portion of the flow channel within the flow channel structure 51 overlaps with the first outer portion RE1d when viewed from above.

[0144] Furthermore, as described above, the second region RE2 includes the second outer portion RE2 d located outside the outer edge OE2 of the heater 56 in a plan view.

[0145] In the second outer portion RE2d, as in the first outer portion RE1d described above, neither the heater 56 nor the head chip 54 is present. Therefore, the presence of this second outer portion RE2d reduces unnecessary portions of the heater 56. This reduces variations in temperature distribution within each head chip 54 or between multiple head chips 54 caused by heat generated by this unnecessary portion. This also has the advantage of reducing the size of the heater 56 and reducing power consumption.

[0146] The area of the first outer portion RE1d is preferably at least one-quarter the area of the first region RE1, more preferably at least one-half and no more than nine-tenths the area of the first region RE1. When the area of the first outer portion RE1d falls within this range, unnecessary portions of the heater 56 can be appropriately reduced. In contrast, if the area of the first outer portion RE1d is too small, the power consumption of the heater 56 increases, or the temperature distribution tends to vary within each head chip 54 or between multiple head chips 54. On the other hand, if the area of the first outer portion RE1d is too large, the heat from the heater 56 becomes difficult to uniformly transfer to the holding portion 5a1, depending on the size of the holding portion 5a1. This, too, tends to vary the temperature distribution within each head chip 54 or between multiple head chips 54. Similarly to the relationship between the area of the first outer portion RE1d and the first region RE1, the area of the second outer portion RE2d is preferably at least one-quarter the area of the second region RE2.

[0147] As previously described, the liquid ejecting head 50 is supported by the support 41. The holder 53 includes, in addition to the holding portion 5a1, a flange portion 5c that contacts the support 41 at a position separated from the holding portion 5a1. The heater 56 heats the holding portion 5a1. The holding portion 5a1 includes a heat receiving portion 5a11 that receives heat from the heater 56.

[0148] Furthermore, the shortest path of heat transfer within the retainer 53, from the heat receiving portion 5a11 to the flange portion 5c, in the transfer path H2 is bent or curved at two or more locations. Here, the term "bending" or "curving" refers to a state where, for example, when the heat transfer path H2 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 transfer path H2 (in other words, the length of the side wall portion 5a12 along the Z-axis) and the length of the connecting portion 5a2 along the transfer path H2 (in other words, the length of the connecting portion 5a2 along the Y-axis) are respectively longer than the thickness of the side wall portion 5a12 in the thickness direction (along the Y-axis) and longer than the thickness of the connecting portion 5a2 in the thickness direction (along the Z-axis). This applies even when the heat transfer path H2 is bent or curved between the connecting portion 5a2 and the outer wall portion 5b, and also when the heat transfer path H2 is bent or curved at portions other than these portions. Furthermore, the "shortest path from the heat receiving portion 5a11 to the flange portion 5c" does not include the path of heat that moves within 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 portion of the shortest path through the retainer 53 from any position on the heat receiving portion 5a11 to the contact point between the flange portion 5c and the support body 41 that does not include the path of heat that moves within the heat receiving portion 5a11 and the flange portion 5c. Therefore, compared to a structure in which the shortest path from the heat receiving portion 5a11 to the flange portion 5c is linear, or a structure in which the thickness of the connecting portion 5a2 is increased so that the surface of the connecting portion 5a2 facing the Z1 direction is aligned with the first surface F1, the thermal resistance of the shortest path can be increased. Consequently, it is possible to prevent heat from the heater 56 from being dissipated to the support body 41 via the flange portion 5c. As a result, the head chip 54 can be efficiently heated by the heater 56 .

[0149] As described above, the heater 56 is positioned relative to the retaining portion 5a1 in a direction (Z1 direction) opposite to the normal direction (Z2 direction) of the nozzle face FN. Furthermore, the retaining portion 5a1 has a sidewall portion 5a12 extending from the heat receiving portion 5a11 in the normal direction (Z2 direction). The heat receiving portion 5a11 and the sidewall portion 5a12 form a recessed portion 53d, an example of a "space" for accommodating the head chip 54. This facilitates assembly of the head chip 54, the retaining portion 53, and the heater 56 by sequentially stacking them.

[0150] In addition, the retainer 53 further includes an outer wall portion 5b connected to the flange portion 5c and surrounding the side wall portion 5a12 when viewed in the normal direction, and a connecting portion 5a2 connecting the side wall portion 5a12 and the outer wall portion 5b. Furthermore, the connecting portion 5a2 extends in a direction intersecting the normal direction, and the side wall portion 5a12 and the outer wall portion 5b extend from the connecting portion 5a2 in a direction opposite to the normal direction.

[0151] Thus, the holder 53 includes a holding portion 5a1 for holding the head chip 54, a flange portion 5c that contacts the support body 41 at a position spaced apart from the holding portion 5a1, an outer wall portion 5b connected to the flange portion 5c and surrounding the holding portion 5a1 when viewed in the normal direction of the nozzle face FN, and a connecting portion 5a2 connecting the holding portion 5a1 and the outer wall portion 5b. Furthermore, the holding portion 5a1 protrudes from the connecting portion 5a2 in a direction opposite to the normal direction, and the outer wall portion 5b extends from the connecting portion 5a2 toward the flange portion 5c in a direction opposite to the normal direction.

[0152] By configuring the retainer 53 in this manner, the shortest path in the heat transfer path H2 from the heat receiving portion 5a11 to the flange portion 5c includes a portion bent or curved by the connection between the side wall portion 5a12 and the connecting portion 5a2, and a portion bent or curved by the connection between the outer wall portion 5b and the connecting portion 5a2. In other words, in the shortest path in the heat transfer path H2 from the heat receiving portion 5a11 to the flange portion 5c, the heat transfer direction in the side wall portion 5a12 and the heat transfer direction in the outer wall portion 5b are opposite to each other.

[0153] Furthermore, as described above, the outer wall portion 5b surrounds the holding portion 5a1 with a gap therebetween in a plan view. Therefore, it is easy to realize the transfer path H2 that bends or curves at two or more locations between the heat receiving portion 5a11 and the flange portion 5c as described above.

[0154] Furthermore, as described above, the flange portion 5c is positioned in a direction opposite to the normal direction of the nozzle surface FN relative to the heat receiving portion 5a11. This allows the outer wall portion 5d to be elongated in the direction along the Z axis, thereby increasing the thermal resistance of the transfer path H2.

[0155] Furthermore, as previously described, the heat receiving portion 5a11 has a first surface F1 and a second surface F2 facing opposite directions. Here, the first surface F1 is the heat receiving surface that receives heat from the heater 56. The head chip 54 has a housing 54h provided with a flow path for ink. The housing 54h is fixed to the second surface F2 and is made of a material with a lower thermal conductivity than the retainer 53. Thus, by making the thermal conductivity of the material constituting the housing 54h lower than that of the retainer 53, heat dissipation from the ink within the head chip 54 can be reduced. Here, heat from the heat receiving portion 5a11 is difficult to transfer to the housing 54h, and as a result, is relatively easy to move along the retainer 53 in the direction toward the support body 41. Therefore, when using such a housing 54h, it is particularly useful in situations where heat dissipation from the support body 41 is difficult, as previously described.

[0156] Furthermore, as described above, the flow channel structure 51 is positioned relative to the retaining portion 5a1 in a direction opposite to the normal direction of the nozzle face FN, and the heater 56 is positioned between the retaining portion 5a1 and the flow channel structure 51. Furthermore, the flow channel structure 51 is positioned so as to be spaced apart from the outer wall portion 5b. This reduces direct heat dissipation from the flow channel structure 51 to the outer wall portion 5b.

[0157] Furthermore, 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 across the entire area when viewed in the normal direction of the nozzle surface FN. This reduces direct heat dissipation from the side wall portion 5a12 to the outer wall portion 5b.

[0158] Furthermore, as previously described, the flange portion 5c completely surrounds the outer wall portion 5b when viewed in the direction normal to the nozzle face FN. Therefore, the flange portion 5c prevents mist generated by ink ejection from the head chip 54 from traveling from the nozzle face FN to a position vertically above the support body 41. On the other hand, while the flange portion 5c could potentially dissipate heat from the heater 56 to the support body 41 from the entire circumference of the flange portion 5c surrounding the outer wall portion 5b, as previously described, the outer circumferential surface of the side wall portion 5a12 is spaced apart from the inner circumferential surface of the outer wall portion 5b when viewed in the direction normal to the nozzle face FN. This reduces direct heat dissipation from the side wall portion 5a12 to the outer wall portion 5b.

[0159] 2. Second Implementation

[0160] In the following, a second embodiment of the present invention will be described. In the following exemplary embodiments, elements having the same functions and effects as those of the first embodiment will be assigned the same reference numerals as those used in the first embodiment, and detailed descriptions thereof will be omitted as appropriate.

[0161] Figure 12 1 is an exploded perspective view of a liquid ejecting head 50A according to the second embodiment. The liquid ejecting head 50A is similar to the liquid ejecting head 50 according to the first embodiment except for the arrangement of the heater 56 and the heat conducting member 57 .

[0162] like Figure 12 As shown, in this embodiment, the arrangement order of the heater 56 and the heat-conducting member 57 along the Z-axis is opposite to that of the first embodiment. Specifically, in the liquid ejecting head 50A, the cover 58, substrate unit 52, flow channel structure 51, heater 56, heat-conducting member 57, holder 53, four head chips 54, and fixing plate 55 are arranged side by side in this order, facing the Z2 direction. The heat-conducting member 57 in this embodiment is an example of a "first heat-conducting member."

[0163] According to the second embodiment described above, the temperature of the head chip 54 can be managed with high accuracy, similarly to the first embodiment described above. Figure 13 In the illustrated example, the planar shapes of the flow channel structure 51, heater 56, and heat conductive member 57 are the same as those of the first embodiment described above. Specifically, the heat conductive member 57 overlaps with the first outer portion RE1b when viewed from above. Furthermore, when the heater 56 and flow channel structure 51 overlap with the first outer portion RE1b when viewed from above, heat from the heater 56 can be transferred to the retaining portion 5a1 without wasting heat.

[0164] However, the plan view shape of the heater 56 is not limited to this. For example, it may be the same as the plan view shape of the flow channel structure 51 or the heat conductive member 57. That is, the heater 56 and the flow channel structure 51 may each overlap with the first outer portion RE1b when viewed from above. In this case, even without the heat conductive member 57 between the heater 56 and the flow channel structure 51, the deviation in the temperature distribution of the flow channel structure 51 can be reduced.

[0165] 3. Third Implementation

[0166] In the following examples, elements having the same functions and effects as those of the first embodiment are assigned the same reference numerals as those used in the first embodiment, and detailed descriptions thereof are omitted as appropriate.

[0167] Figure 13This figure illustrates the heat transfer path H1 and the heat transfer path H2 from the heater 56 in the third embodiment. A liquid ejecting head 50B of this embodiment is identical to the liquid ejecting head 50 of the first embodiment, except that it includes a retainer 53B in place of the retainer 53. The retainer 53B is identical to the retainer 53, except that it includes an outer wall portion 5d in place of the outer wall portion 5b.

[0168] The outer wall portion 5d connects the outer periphery of the connection portion 5a2 of the bottom portion 5a to the inner periphery of the flange portion 5c. Here, the outer wall portion 5d includes 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.

[0169] The first wall portion 5d1 is cylindrical and extends from the connecting portion 5a2 in the Z1 direction. The first plate portion 5d2 is plate-shaped and extends from the first wall portion 5d1 in a direction perpendicular to the Z axis, approaching the retaining portion 5a1. The second wall portion 5d3 is cylindrical and extends from the first plate portion 5d2 in the Z1 direction. The second plate portion 5d4 is plate-shaped and extends from the second wall portion 5d3 in a direction perpendicular to the Z axis, moving away from the retaining portion 5a1. The third wall portion 5d5 is cylindrical and extends from the second plate portion 5d4 in the Z1 direction.

[0170] Even according to the third embodiment described above, the temperature of the head chip 54 can be managed with high precision, similar to the first embodiment described above. In this embodiment, since the bottom 5a and the flange 5c are connected via the outer wall 5d as described above, the heat transfer path H2 from the heater 56 to the support body 41 is bent or curved at least in six places. Figure 13 In the figure, the six locations where the transfer path H2 bends or curves are indicated by the areas enclosed by two-dot chain lines. When the number of bends or curves in the transfer path H2 is four or more, the thermal resistance of the transfer path H2 can be easily improved compared to the first embodiment. Furthermore, as in the first embodiment, the "shortest path from the heat receiving portion 5a11 to the flange portion 5c" does not include the path of heat moving within the heat receiving portion 5a11 and the flange portion 5c.

[0171] 4. Modifications

[0172] The above-described embodiments can be modified in various ways. Specific modifications that can be applied to the above-described embodiments are exemplified below. Two or more embodiments arbitrarily selected from the following examples can be appropriately combined within a range that does not conflict with each other.

[0173] 4-1. Modification 1

[0174] In the above embodiment, the plan view shape of the holding portion 5a1 is different from a rectangle depending on the arrangement of the four head chips 54. The plan view shape of the holding portion 5a1 is not limited to the above embodiment, and may be a rectangle or a substantially rectangle, for example.

[0175] 4-2. Modification 2

[0176] In the above embodiment, the plan view shape of the heater 56 is different from a rectangle depending on the arrangement of the four head chips 54. The plan view shape of the heater 56 is not limited to the above embodiment, and may be a rectangle or a substantially rectangle, for example.

[0177] 4-3. Modification 3

[0178] While the above embodiment exemplifies a structure using a single heat conducting member 57, the present invention is not limited to this structure. For example, a combination of the first and second embodiments is also possible. In other words, heat conducting members 57 may be disposed between the heater 56 and the retainer 53, and between the heater 56 and the flow channel structure 51.

[0179] 4-4. Modification 4

[0180] An elastic sheet may also be arranged between the retainer 53 and the flow channel structure 51, both of which are rigid bodies. As such an elastic sheet, an elastomer or the like can be used. For example, it is preferable to select a heat-conducting sheet having a higher thermal conductivity than the resin material constituting the housing 54h of the head chip 54. As such an elastic heat-conducting sheet having a higher thermal conductivity than the resin material, it is preferable to use a material having a thermal conductivity of 1.0 W / m·K or more. Specifically, as the heat-conducting sheet, it is preferable to use an acrylic or silicon sheet, or 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 an elastic material such as an elastomer contains a filler such as carbon fiber, a ceramic oxide such as silicon dioxide or aluminum oxide, or a ceramic nitride such as silicon nitride or boron nitride. By filling the gap between the retainer 53 and the flow channel structure 51 with elastic material in this way, even if a manufacturing error occurs in the thickness dimension of the retainer 53 or the flow channel structure 51 along the Z-axis, the close contact between the heat-conducting component 57 or the heater 56 and the heating object such as the retainer 53 or the flow channel structure 51 can be improved, thereby effectively transferring the heat from the heater 56 to the heating object.

[0181] 4-5. Modification 5

[0182] The “outer edge OE2 of the heater 56 ” in the aforementioned embodiment may be referred to as the outer edge of the region where the heating resistor included in the heater 56 is formed.

[0183] 4-6. Modification 6

[0184] The heater 56 does not need to overlap with the first outer portion RE1b when viewed from above. This configuration allows the heater 56 to be smaller in area. Furthermore, since the head chip 54_1, the head chip 54_2, and the retaining portion 5a1 are not present in the first outer portion RE1b, unnecessary heat generation by the heater 56 can be further reduced by not overlapping with the first outer portion RE1b when viewed from above.

[0185] 4-7. Modification 7

[0186] Although the aforementioned embodiment illustrates a configuration in which the liquid ejecting head 50 includes four head chips 54, the invention is not limited to this configuration and may include two, three, or five or more head chips. Furthermore, although the aforementioned embodiment illustrates a plurality of head chips 54 arranged in a staggered pattern along the longitudinal direction of the head chips 54, the invention is not limited to this configuration and may include a plurality of head chips 54 arranged in a staggered pattern along the transverse direction of the head chips 54.

[0187] 4-8. Modification 8

[0188] While the aforementioned embodiment illustrates a serial-type liquid ejecting apparatus 100 in which the support body 41 supporting the liquid ejecting heads 50 reciprocates, the present invention can also be applied to a line-type liquid ejecting apparatus in which multiple nozzles N are distributed across the entire width of the medium M. That is, the support body supporting the liquid ejecting heads 50 is not limited to a serial-type carriage and may also be a structure that supports the liquid ejecting heads 50 in a line-type manner. In this case, for example, multiple liquid ejecting heads 50 are arranged side by side in the width direction of the medium M, and the multiple liquid ejecting heads 50 are collectively supported by a single support body.

[0189] 4-9. Modification 9

[0190] The liquid ejection device exemplified in the above embodiment can be used in various devices, including fax machines and copiers, in addition to being used in printing-specific devices. Of course, the applications of liquid ejection devices are not limited to printing. For example, a liquid ejection device that ejects a solution of a color material is used as a device for manufacturing color filters for display devices such as liquid crystal display panels. Furthermore, a liquid ejection device that ejects a solution of a conductive material is used as a device for manufacturing wiring or electrodes for wiring substrates. Furthermore, a liquid ejection device that ejects a solution of an organic substance related to a living organism is used as a device for manufacturing, for example, biochips.

[0191] Explanation of symbols

[0192] 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…conveying mechanism; 40…moving mechanism; 41…support body; 41a…opening; 41b…threaded hole; 42…conveying belt; 50…liquid ejecting head; 50A…liquid ejecting head; 50B…liquid ejecting head; 51…flow path structure; 51a…flow path component; 51b…connecting pipe; 51c…wiring hole; 52…substrate unit; 52 a…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…threaded hole; 53h…recess; 53i…threaded hole; 53j…hole; 53k…threaded hole; 53l…flow channel 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 channel substrate; 54b…pressure chamber substrate; 54c…nozzle plate; 54d…vibration absorber; 54e…vibration plate; 54f…piezoelectric element; 5 4g…protective plate; 54h…housing; 54i…wiring board; 54j…driving circuit; 54k…frame; 55…fixing plate; 55a…opening; 56…heater; 56a…hole; 56b…hole; 57…heat conducting member; 57a…hole; 57b…wiring hole; 57c…hole; 58…cover; 58a…through hole; 58b…opening; 100…liquid ejecting device; C…pressure chamber; CP…center; D…driving signal; DM…transmission 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…introduction port; IPa…intersection; IPb… Intersection point; IPc…intersection point; IPd…intersection point; L1…first column; L2…second column; M…medium; MP1…midpoint; MP2…midpoint; N…nozzle; Na…connecting channel; OE1…outer edge; OE2…outer edge; PA1…first part; PA2…second part; R…reservoir; R1…space; R2…space; RE1…first region; RE1a…first inner part; RE1b…first outer part; RE1c…first inner part; RE1d…first outer part; RE2…second region; RE2a…second inner part; RE2b…second outer part; RE2c…second inner part; RE2d…second outer part; Ra…supply channel; S…control signal; VS…rectangle.

Claims

1. A liquid ejecting head, characterized in that: have: a plurality of head chips, each of the head chips having a nozzle surface, and a plurality of nozzles for spraying liquid are provided on the nozzle surface; a thermally conductive holder for holding the plurality of head chips; a heat-conductive flow channel structure provided with a flow channel for a liquid supplied to the plurality of head chips; A planar heater is arranged between the retainer and the flow channel structure and in a direction parallel to the nozzle surface. The heater overlaps with the plurality of head chips in a plan view.

2. The liquid ejecting head according to claim 1, wherein Each of the plurality of head chips includes a nozzle plate, and each of the nozzle plates includes the nozzle surface.

3. The liquid ejecting head according to claim 1 or 2, wherein: The flow channel structure overlaps with the plurality of head chips in the plan view.

4. The liquid ejecting head according to claim 1, wherein The heater includes a first main surface and a second main surface, the first main surface facing the holder, and the second main surface facing the opposite side of the first main surface and facing the flow channel structure. The first main surface and the second main surface are respectively arranged parallel to the nozzle surface so as to overlap with the plurality of head chips in the plan view.

5. The liquid ejecting head according to claim 4, wherein The heater includes a side surface connecting the first main surface and the second main surface, and is arranged so that the side surface is orthogonal to the nozzle surface. The surface areas of the side surfaces are respectively smaller than the surface areas of the first main surface and the second main surface.

6. The liquid ejecting head according to claim 4 or 5, wherein: The nozzle surface, the first main surface, and the second main surface are surfaces perpendicular to a stacking direction in which the plurality of head chips, the holder, the heater, and the flow channel structure are stacked.

7. The liquid ejecting head according to claim 1, wherein The holder has a holding portion, and the holding portion contains the plurality of head chips when viewed from above. When two directions intersecting each other along the nozzle surface are defined as a first direction and a second direction, Each of the plurality of head chips is in a strip shape along the first direction. The plurality of head chips include a first head chip and a second head chip, The first head chip and the second head chip are arranged so as to be offset from each other in both the first direction and the second direction. When one of the four sides of the imaginary rectangle circumscribing the assembly of the plurality of head chips in the plan view is set as a first side, a side connected to one end of the first side is set as a second side, and a side connected to the other end of the first side is set as a third side, The first head chip is in contact with the first side and the third side when viewed from above. The second head chip is in contact with the second side when viewed from above. A first region surrounded by the first side, the second side, the first head chip, and the second head chip in the plan view includes a first outer portion located outside the outer edge of the holding portion.

8. The liquid ejecting head according to claim 7, wherein The first side has a first portion that delimits the first area. The second side has a second portion that delimits the first area, In the plan view, the outer edge of the holding portion intersects both the first portion and the second portion.

9. The liquid ejecting head according to claim 8, wherein When viewed from above, the intersection of the outer edge of the retaining portion and the first part is located closer to the first head chip than the midpoint of the first part, and the intersection of the outer edge of the retaining portion and the second part is located closer to the second head chip than the midpoint of the second part.

10. The liquid ejecting head according to any one of claims 7 to 9, wherein The outer shape of the retainer in the plan view is rectangular or substantially rectangular.

11. The liquid ejecting head according to any one of claims 7 to 9, wherein A fixing plate is further provided for fixing the plurality of head chips relative to the holder. The fixing plate has an opening for exposing the nozzle surface. The fixing plate has a rectangular or substantially rectangular shape when viewed from above.

12. The liquid ejecting head according to any one of claims 7 to 9, wherein In the plan view, the heater and the flow channel structure respectively overlap with the first outer portion.

13. The liquid ejecting head according to any one of claims 7 to 9, wherein The device further comprises a first heat conducting member, the first heat conducting member being arranged between the holding portion and the heater and having a higher thermal conductivity than the holder, In the plan view, the first heat conducting component overlaps with the first outer portion.

14. The liquid ejecting head according to claim 13, wherein The holder is provided with a flow channel for supplying liquid to the plurality of head chips. The holder is made of metal or ceramic.

15. The liquid ejecting head according to any one of claims 7 to 9, wherein In the plan view, the first region includes a portion that does not overlap with the heater.

16. The liquid ejecting head according to claim 15, wherein A second heat conducting member is further provided, the second heat conducting member being arranged between the heater and the flow channel structure and having a higher heat conductivity than the flow channel structure, In the plan view, the second heat conduction member and the flow channel structure respectively overlap with the first outer portion.

17. The liquid ejecting head according to claim 16, wherein The flow channel structure is made of stainless steel or ceramics.

18. The liquid ejecting head according to any one of claims 7 to 9, wherein The plurality of head chips include a third head chip and a fourth head chip, The third head chip and the fourth head chip are arranged so as to be offset from each other in both the first direction and the second direction. When the side other than the first side, the second side, and the third side among the four sides of the imaginary rectangle is set as the fourth side, The third head chip is in contact with the third side when viewed from above. The fourth head chip is in contact with the second side and the fourth side when viewed from above. A second region surrounded by the third side, the fourth side, the third head chip, and the fourth head chip in the plan view includes a second outer portion located outside the outer edge of the holding portion.

19. The liquid ejecting head according to any one of claims 7 to 9, wherein The center of the first region is located outside the outer edge of the holding portion.

20. The liquid ejecting head according to any one of claims 7 to 9, wherein The area of the first outer portion is greater than or equal to one quarter of the area of the first region.

21. The liquid ejecting head according to any one of claims 7 to 9, wherein The holder includes an outer wall portion that surrounds the holding portion with a gap therebetween in the plan view.

22. A liquid ejecting device comprising: The liquid ejecting head according to any one of claims 1 to 21; The liquid storage portion stores the liquid supplied to the liquid ejecting head.

Images