Liquid ejection head and liquid ejection recording apparatus

Abstract

Provided are a liquid ejection head and a liquid ejection recording apparatus capable of obtaining stable ejection performance. An inkjet head (5) includes: a head chip provided with a plurality of ejection channels arranged in order from a +X direction to a -X direction in an X direction, which eject ink inside the ejection channels; a flow path member (44) provided with a guide flow path (104) that guides the ink from the +X direction to the -X direction in the X direction, and the guide flow path (104) is connected to each of the ejection channels; and a substrate unit that encapsulates a plurality of drive ICs (84) arranged in the X direction, and is thermally connected to the flow path member (44), and the flow path member (44) is provided with a cooling flow path (102) that guides the ink from the -X direction to the +X direction in the X direction, and cools the plurality of drive ICs (84).

Description

Technical Field

[0001] This invention relates to a liquid jet head and a liquid jet recording device. Background Technology

[0002] Patent Document 1 discloses a liquid jet head that efficiently cools the driver IC of the circuit section and simplifies the device configuration. The liquid jet head disclosed in Patent Document 1 includes a head, a circuit section, and a cooling section. The head includes a supply path for flowing liquid supplied from the outside, a pressure chamber communicating with the supply path, a drive element for driving the pressure chamber, and a nozzle communicating with the pressure chamber, from which droplets are ejected. The circuit section supplies a drive waveform to the drive element. The cooling section includes a cooling path for flowing liquid and is fixedly connected to the circuit section. Furthermore, in Patent Document 1, the liquid flows in parallel in the supply path and the cooling path.

[0003] Prior art literature Patent documents Patent document 1: Japanese Patent Application Publication No. 2015-171806. Summary of the Invention

[0004] The problem that the invention aims to solve In the liquid injection head disclosed in Patent Document 1, liquid flows to a cooling flow path provided in parallel with the supply flow path, thereby driving the IC to be cooled. Therefore, the liquid flowing in the cooling flow path heats up as it moves downstream. Additionally, due to the heat effect on the drive element that drives the pressure chamber connected to the supply flow path, the liquid flowing in the supply flow path heats up as it moves downstream. In Patent Document 1, the flow direction of the liquid in the cooling flow path is the same as the flow direction of the liquid in the supply flow path. Furthermore, the upstream end of the cooling flow path is connected to the upstream end of the supply flow path, and the downstream end of the cooling flow path is connected to the downstream end of the supply flow path. That is, the liquid heated in the cooling flow path and the liquid heated in the supply flow path merge on one side in the extending direction of the cooling and supply flow paths. Therefore, in the liquid injection head disclosed in Patent Document 1, heat is concentrated on one side in the extending direction of the cooling and supply flow paths, and the temperature difference between the two sides in the extending direction becomes larger in the liquid injection head as a whole.

[0005] In the liquid jet head disclosed in Patent Document 1, the heat distribution deviation throughout the liquid jet head is large. Therefore, if multiple pressure chambers are arranged in a straight line along the extension direction of the cooling flow path and the supply flow path, the temperature difference caused by the position of the pressure chambers becomes large. As a result, there is a possibility of poor discharge, such as differences in liquid viscosity and liquid discharge volume due to the position of the pressure chambers.

[0006] This disclosure is made in view of the aforementioned problems, and its purpose is to provide a liquid jet head and a liquid jet recording device that can achieve stable ejection performance.

[0007] Solution for solving the problem To address the aforementioned issues, this disclosure adopts the following format.

[0008] (1) A liquid injection head according to one aspect of the present disclosure includes: an injection section having a plurality of pressure chambers arranged sequentially from one side to the other in a first direction, for injecting liquid inside the pressure chambers; a flow path member having a guide flow path for guiding liquid from one side to the other in the first direction, and the guide flow path being connected to each of the pressure chambers; and a circuit board having a plurality of drive control units arranged along the first direction and being thermally connected to the flow path member, the flow path member having a cooling flow path for guiding liquid from the other side to the first side in the first direction and cooling the plurality of drive control units.

[0009] The liquid jet head has two main heat sources: a jet section with a pressure chamber for jetting liquid and multiple drive control units. According to this specification, the flow path component includes a guide flow path connected to the pressure chamber of the jet section, which serves as one of these heat sources. Additionally, the flow path component includes a cooling flow path for cooling the multiple drive control units, which serve as one of these heat sources.

[0010] In these guiding flow paths and cooling flow paths, the flow direction of the liquid in the guiding flow path is opposite to the flow direction of the liquid in the cooling flow path that cools the drive control unit. Therefore, in the guiding flow path, the other side of the first direction becomes relatively hot compared to the first side. On the other hand, in the cooling flow path, the one side of the first direction becomes relatively hot compared to the other side.

[0011] As a result, the temperature distribution when viewed as a whole in the liquid injection head is more uniform compared to cases where the flow direction of the liquid in the guide flow path and the flow direction of the liquid in the cooling flow path are the same. This uniform heat distribution throughout the liquid injection head leads to uniform temperature of the liquid supplied to each pressure chamber, and also uniform viscosity of the liquid in each pressure chamber. Consequently, stable ejection performance can be obtained. Furthermore, the uniform heat distribution throughout the liquid injection head reduces the maximum achievable temperature of the drive control unit, enabling stable operation of the drive control unit.

[0012] (2) In the liquid injection head of the above (1) pattern, the flow path component is provided with an inflow flow path for guiding the liquid flowing in from the outside and an outflow flow path for guiding the liquid discharging to the outside, and the guiding flow path and the cooling flow path are arranged in parallel between the inflow flow path and the outflow flow path.

[0013] According to this design, the distance from the inflow path to the pressure chamber is shorter than that in the case where a cooling path is arranged between the inflow path and the guide path. Therefore, the pressure loss up to the pressure chamber can be reduced, insufficient liquid supply to the pressure chamber can be prevented, and liquid can be stably ejected from the pressure chamber.

[0014] (3) In the liquid injection head of the above (2) pattern, the flow path component is provided with: a first connecting flow path disposed between the upstream end of the inflow flow path and the upstream end of the cooling flow path; and a second connecting flow path disposed between the downstream end of the cooling flow path and the discharge flow path, wherein the first connecting flow path and the second connecting flow path guide the liquid from the first direction to the other side.

[0015] According to this design, a meandering flow path is formed, consisting of a first connecting flow path, a cooling flow path, and a second connecting flow path. Therefore, the overall heat distribution of the liquid jet head can be further homogenized.

[0016] (4) In the liquid injection head of the above (1) pattern, the flow path component is provided with an inflow flow path for guiding the liquid flowing in from the outside and an outflow flow path for guiding the liquid discharged to the outside, and the inflow flow path, the guiding flow path, the cooling flow path and the outflow flow path are arranged in series.

[0017] According to this design, the liquid supplied to the pressure chamber flows through the cooling flow path. Therefore, compared to the case where the guide flow path and the cooling flow path are arranged in parallel between the inflow and outlet flow paths, pressure dispersion throughout the liquid flow path can be prevented. Thus, if the pressure at the inlet of the inflow path and the outlet of the outlet flow path are set to the same conditions as in the case where the guide flow path and the cooling flow path are arranged in parallel between the inflow and outlet flow paths, the liquid flow rate increases. Consequently, the cooling efficiency in the cooling flow path can be improved.

[0018] (5) In the liquid spray head of the above (4) pattern, the above inflow path, the above cooling path, the above guiding path, and the above discharge path are arranged in the order of the above inflow path, the above cooling path, the above guiding path, and the above discharge path.

[0019] Generally, the drive control section is at a higher temperature than the injection section. According to this design, the liquid flows into the cooling flow path before flowing into the guide flow path. Therefore, compared to the case where the liquid, whose temperature has already risen while flowing into the guide flow path, flows into the cooling flow path, a lower-temperature liquid can be used for cooling the drive control section. Thus, the cooling efficiency of the drive control section can be improved.

[0020] (6) In the liquid spray head of the above (4) pattern, the above inflow path, the above guide path, the above cooling path, and the above discharge path are arranged in the order of the above inflow path, the above guide path, the above cooling path, and the above discharge path.

[0021] According to this design, the distance from the inflow path to the pressure chamber is shorter than that in the case where a cooling path is arranged between the inflow path and the guide path. Therefore, the pressure loss up to the pressure chamber can be reduced, insufficient liquid supply to the pressure chamber can be prevented, and liquid can be stably ejected from the pressure chamber.

[0022] (7) In the liquid jet head of the above (5) or (6) pattern, the flow path component is provided with: a third connecting flow path that connects the above guiding flow path to the above cooling flow path; and a fourth connecting flow path that connects to the end opposite to the end of the cooling flow path and the end connected to the third connecting flow path, wherein at least one of the third connecting flow path and the fourth connecting flow path guides the liquid from the above one side of the first direction to the other side in at least a portion.

[0023] According to this design, a meandering flow path is formed, consisting of a third connecting flow path, a cooling flow path, and a fourth connecting flow path. Therefore, the overall heat distribution of the liquid jet head can be further homogenized.

[0024] (8) In any of the liquid injection heads of the above (2) to (7), there is an inflow port connected to the upstream end of the inflow path and an outlet port connected to the downstream end of the outlet path, wherein the inflow port and the outlet port are arranged adjacent to each other in the first direction on one side or the other side, which is closer to the center of the flow path component than the center of the flow path component.

[0025] According to this design, the liquid supply pipe connected to the inlet port and the liquid discharge pipe connected to the outlet port can be arranged close together. Therefore, compared with the case where the inlet port and outlet port are arranged separately, the inlet port and outlet port are less likely to obstruct other components.

[0026] Furthermore, the liquid flows from one direction in the cooling flow path and from one direction in the guiding flow path. Therefore, when the guiding flow path and the cooling flow path are arranged in series, the length of the flow path for liquid flow is minimized.

[0027] (9) In the liquid jet head of the above (8) pattern, the inflow path has a separation section that separates from the discharge path as it moves downstream.

[0028] According to this design, the liquid flowing in the inflow path can be prevented from heating up due to the high-temperature liquid flowing in the outlet path. Therefore, compared to the case without a separation section, supplying a low-temperature liquid to the cooling path can improve the cooling efficiency of the drive control unit.

[0029] (10) In any of the above-described (2) to (9) spray heads, the flow path component is provided with a second cooling flow path that allows the liquid to flow from one side of the first direction to the other side, and the second cooling flow path cools the drive control unit located on the other side of the plurality of drive control units.

[0030] According to this specification, the drive control unit located in a position prone to heating due to the high temperature of the liquid flowing through the discharge path can be locally cooled. Therefore, the maximum temperature reached by the drive control unit can be further reduced.

[0031] (11) A liquid jet recording device according to one aspect of the present disclosure has a liquid jet head of any of the aspects of (1) to (10) above.

[0032] According to this specification, a liquid jet head having the above-described specification can thus provide a liquid jet recording device with stable ejection performance.

[0033] The effects of the invention According to this disclosure, stable ejection performance can be obtained. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the printer according to the first embodiment.

[0035] Figure 2 This is a schematic diagram of the inkjet head and ink circulation mechanism according to the first embodiment.

[0036] Figure 3 This is a perspective view of the inkjet head according to the first embodiment.

[0037] Figure 4 This is a perspective view showing a portion of the inkjet head according to the first embodiment.

[0038] Figure 5 It is an enlarged exploded perspective view including the head chip involved in the first embodiment.

[0039] Figure 6 It is a cross-sectional view including the ejection channel in the head chip according to the first embodiment.

[0040] Figure 7 It is a cross-sectional view including the non-ejection channel in the head chip according to the first embodiment.

[0041] Figure 8 This is an exploded perspective view including the first flow path plate and flow path cover according to the first embodiment.

[0042] Figure 9 This is a schematic diagram of an inkjet head including the ink flow path according to the first embodiment.

[0043] Figure 10 This is a schematic diagram of an inkjet head including the ink flow path involved in the variation of the first embodiment.

[0044] Figure 11 This is a schematic diagram of an inkjet head including the ink flow path according to the second embodiment.

[0045] Figure 12 This is a schematic diagram of an inkjet head including the ink flow path involved in the variation of the second embodiment.

[0046] Figure 13 This is a schematic diagram of an inkjet head including the ink flow path involved in the third embodiment.

[0047] Figure 14 This is a schematic diagram of an inkjet head including the ink flow path involved in the variation of the third embodiment.

[0048] Figure 15 This is a schematic diagram of an inkjet head including the ink flow path involved in the fourth embodiment.

[0049] Figure 16 This is a schematic diagram of an inkjet head including the ink flow path involved in the variation of the fourth embodiment. Detailed Implementation

[0050] Hereinafter, embodiments relating to this disclosure will be described with reference to the accompanying drawings. In the embodiments or variations described below, the same reference numerals are sometimes used for corresponding configurations and descriptions are omitted. Furthermore, in the following description, expressions such as "parallel," "orthogonal," "center," and "coaxial," indicating relative or absolute configurations, not only refer to such configurations strictly, but also to states of relative displacement by an angle or distance with tolerance or to the extent that the same function can be obtained. In the following embodiments, an inkjet printer (hereinafter simply referred to as a printer) that uses ink (liquid) to record on a recording medium is illustrated by example. Furthermore, in the accompanying drawings used in the following description, the scale of each component has been appropriately altered to make each component a recognizable size.

[0051] (First Embodiment) [Printer 1] Figure 1 This is a schematic diagram of printer 1.

[0052] Figure 1 The printer (liquid jet recording device) 1 shown in the figure has a pair of conveying mechanisms 2 and 3, an ink tank 4, an inkjet head (liquid jet head) 5, an ink circulation mechanism 6, and a scanning mechanism 7.

[0053] In the following description, an orthogonal coordinate system of X, Y, and Z is used as needed. In this case, the X direction is aligned with the transport direction (sub-scanning direction) of the recording medium P (e.g., paper, etc.). The Y direction is aligned with the scanning direction (main scanning direction) of the scanning mechanism 7. The Z direction shows the height direction (gravity direction) orthogonal to the X and Y directions. In the following description, the X, Y, and Z directions are described with the side of the arrow in the figure as the positive (+) side and the side opposite to the arrow as the negative (-) side. In this specification, the +Z side corresponds to the upper part of the gravity direction, and the -Z side corresponds to the lower part of the gravity direction.

[0054] The conveying mechanisms 2 and 3 convey the recording medium P towards the +X side. The conveying mechanisms 2 and 3 each include, for example, a pair of rollers 11 and 12 extending along the Y direction.

[0055] The ink tank 4 contains, for example, four colors of ink: yellow, magenta, cyan, and black. Each inkjet head 5 is configured to eject one of the four colors of ink—yellow, magenta, cyan, and black—depending on the ink tank 4 it is connected to.

[0056] Figure 2 This is a schematic diagram of the inkjet head 5 and the ink circulation mechanism 6.

[0057] like Figure 2 As shown, the ink circulation mechanism 6 circulates ink between the ink tank 4 and the inkjet head 5. Specifically, the ink circulation mechanism 6 includes: a circulation path 23 having an ink supply pipe 21 and an ink discharge pipe 22; a pressure pump 24 connected to the ink supply pipe 21; and a suction pump 25 connected to the ink discharge pipe 22.

[0058] The pressure pump 24 pressurizes the ink supply tube 21 and delivers ink to the inkjet head 5 through the ink supply tube 21. As a result, the ink supply tube 21 is under positive pressure relative to the inkjet head 5.

[0059] The suction pump 25 depressurizes the ink discharge tube 22, drawing ink from the inkjet head 5 through it. This creates a negative pressure on the ink discharge tube 22 side relative to the inkjet head 5. The ink can then circulate between the inkjet head 5 and the ink tank 4 via the circulation path 23, driven by the pressure pump 24 and the suction pump 25.

[0060] like Figure 1 As shown, the scanning mechanism 7 causes the inkjet head 5 to reciprocate scanning along the Y direction. The scanning mechanism 7 includes: a pair of guide rails 28 and 29 extending along the Y direction; a carriage 30 movably supported by the pair of guide rails 28 and 29; and a drive mechanism 31 that moves the carriage 30 along the Y direction. Furthermore, the transport mechanisms 2 and 3 and the scanning mechanism 7 move the inkjet head 5 and the recording medium P relative to each other.

[0061] The drive mechanism 31 is disposed between guide rails 28 and 29 in the X direction. The drive mechanism 31 includes: a pair of pulleys 32 and 33, which are disposed at intervals along the Y direction; an annular belt 34, which is wound between the pair of pulleys 32 and 33; and a drive motor 35, which drives one of the pulleys 32 to rotate.

[0062] The carriage 30 is connected to the annular belt 34. The carriage 30 is equipped with a plurality of inkjet heads 5. In this embodiment, inkjet heads 5 that emit yellow ink, inkjet heads 5 that emit magenta ink, inkjet heads 5 that emit cyan ink, and inkjet heads 5 that emit black ink are provided. These inkjet heads 5 are arranged side-by-side along the Y direction.

[0063] [Inkjet Head 5] Figure 3 This is a 3D view of inkjet head 5. Figure 4 It is a 3D diagram showing a portion of the inkjet head 5 disassembled.

[0064] like Figure 3 , Figure 4 As shown, the inkjet head 5 includes a base component 40, an ejection module 41, and a nozzle protector 42. The ejection module 41 or the nozzle protector 42 is fixed to the base component 40. The base component 40 is fixed to the carriage 30.

[0065] [Base component 40] The base component 40 is formed as a plate with the Z-direction as its thickness direction and the X-direction as its long side direction. Furthermore, in this embodiment, the base component 40 is integrally formed of a metallic material.

[0066] A module receiving portion 40a is formed in the base member 40. The module receiving portion 40a extends through the base member 40 in the Z direction. The ejection module 41 can be inserted into the module receiving portion 40a. That is, with respect to the ejection module 41, the -Z direction end is inserted into the module receiving portion 40a, thereby holding it in a state of being upright from the base member 40 in the +Z direction. In the base member 40, a method for mounting the base member 40 to the carriage 30 (see reference) is formed. Figure 1 Mounting holes, etc.

[0067] [Ejection Module 41] like Figure 3 , Figure 4 As shown, the ejection module 41 is formed as a plate with its thickness along the Y direction. The ejection module 41 is capable of ejecting ink from the ink tank 4 (see reference 4). Figure 1 The ink supplied is ejected toward the recording medium P. The ejection module 41 includes a head chip 43 (ejection section), a flow path component 44, and a return plate 45 (see reference). Figure 5 ), Nozzle plate 46 (refer to) Figure 5 ) and substrate unit 47 (circuit substrate).

[0068] [Head Chip 43] Figure 5 This is an enlarged exploded perspective view including the head chip 43. Two head chips 43 are provided such that they sandwich the second flow path plate 78 (described later) of the flow path component 44 in the Y direction. That is, in this embodiment, two (a pair) head chips 43 are provided. Furthermore, these head chips 43 have a symmetrical structure that sandwiches the second flow path plate 78. Therefore, the structure of one head chip 43 will be described, and a detailed description of the structure of the other head chip 43 will be omitted.

[0069] The head chip 43 includes an actuator plate 48 and a cover plate 49. Multiple channels 50 and 51 are formed on the actuator plate 48. One channel 50 is filled with ink and is hereinafter referred to as the ejection channel 50 (pressure chamber). Another channel 51 is not filled with ink and is hereinafter referred to as the non-ejection channel 51.

[0070] Figure 6 It is a cross-sectional view including the ejection channel 50 in a head chip 43. Figure 7 It is a cross-sectional view including the non-ejection channel 51 in a head chip 43.

[0071] like Figure 6 As shown, a common electrode 56 is formed on the inner surface of the discharge channel 50. The common electrode 56 is formed integrally on the inner surface of the discharge channel 50.

[0072] like Figure 7As shown, individual electrodes 58 are formed on the inner surface of the non-ejection channel 51. The individual electrodes 58 are formed on the inner surfaces of the non-ejection channel 51 that are opposite each other in the X direction.

[0073] A liquid supply path 62 is formed in the cover plate 49, extending through the cover plate 49 in the Y direction and communicating with the discharge channel 50. The liquid supply path 62 includes a common ink chamber 63 and a plurality of slits 64 communicating with the common ink chamber 63 and arranged at intervals in the X direction. The common ink chamber 63 is connected to each discharge channel 50 through the slits 64. On the other hand, the common ink chamber 63 is not connected to the non-discharge channel 51. Ink flows into the common ink chamber 63 through the flow path component 44.

[0074] The slit 64 is positioned opposite the common ink chamber 63 in the Y direction. The slit 64 communicates with the common ink chamber 63 and the ejection channel 50.

[0075] A common electrode 56 formed on the inner surface of the plurality of ejection channels 50 is electrically connected to the driving substrate 82 of the substrate unit 47, which will be described later. Individual electrodes 58 formed on the inner surface of the plurality of non-ejection channels 51 are electrically connected to the wiring substrate 83 of the substrate unit 47, which will be described later.

[0076] like Figure 5 As shown, the individual head chips 43 are arranged at intervals along the Y direction. The arrangement of the output channels 50 and non-output channels 51 of one head chip 43 relative to the output channels 50 and non-output channels 51 of another head chip 43 is offset by half a pitch along the X direction.

[0077] As described above, in this embodiment, the head chip 43 is provided with a plurality of ejection channels 50 (pressure chambers) arranged sequentially from the +X direction (one side) in the X direction (first direction) to the -X direction (the other side), and ink inside the ejection channels 50 is ejected.

[0078] [Flow path component 44] like Figure 4 As shown, the flow path component 44 includes a first flow path plate 72, a flow path cover 73, an inlet port 74, an outlet port 75, an inlet manifold 76, an outlet manifold 77, a second flow path plate 78, and a heat transfer plate 79.

[0079] Figure 8 This is an exploded perspective view including the first flow path plate 72 and the flow path cover 73. (See attached image.) Figure 8 As shown, the first flow path plate 72 is formed as a rectangular plate with its surface and back facing the Y direction. The first flow path plate 72 is integrally formed from the same component. Viewed from the Y direction, the first flow path plate 72 has a rectangular shape.

[0080] like Figure 8 As shown, two insertion portions 72a are provided at the -Z direction end of the first flow path plate 72. These insertion portions 72a are separated along the X direction and arranged along the X direction. Each insertion portion 72a is formed as a hollow body having an internal space open towards the -Z direction. One insertion portion 72a is disposed at the +X direction end of the first flow path plate 72, as shown in the figure. Figure 3 , Figure 4 As shown, the inlet manifold 76 is inserted from the -Z direction. Another insertion portion 72a is disposed at the end of the first flow path plate 72 in the -X direction, as shown... Figure 3 , Figure 4 As shown in the diagram, the outlet manifold 77 is inserted from the -Z direction.

[0081] Inside the first flow path board 72, such as Figure 8 As shown, a first internal flow path 72b, a second internal flow path 72c, a third internal flow path 72d, and a fourth internal flow path 72e are provided. The first internal flow path 72b extends in the Z direction and is connected to the inflow port 74 from the -Z direction. The second internal flow path 72c extends in the Z direction and is connected to the internal space of the insertion portion 72a into which the inlet manifold 76 is inserted from the +Z direction.

[0082] The third internal flow path 72d extends along the Z direction and is connected in the +Z direction to the internal space of the insertion portion 72a into which the outlet manifold 77 is inserted. The fourth internal flow path 72e extends along the Z direction and is connected in the -Z direction to the internal space of the discharge port 75.

[0083] like Figure 8 As shown, a first groove 72f and a second groove 72g are provided in the first flow path plate 72. Both the first groove 72f and the second groove 72g are exposed on the surface of the first flow path plate 72 in the +Y direction. That is, the first groove 72f and the second groove 72g are open in the -Y direction.

[0084] The first groove 72f connects the first internal flow path 72b and the second internal flow path 72c, guiding ink between the first internal flow path 72b and the second internal flow path 72c. For example... Figure 8As shown, the first groove portion 72f has a first inlet end portion 72h that connects to the first internal flow path 72b in the -Z direction. Additionally, the first groove portion 72f has a first vertical portion 72i extending from the first inlet end portion 72h in the -Z direction. Furthermore, the first groove portion 72f has a first inclined portion 72j, which displaces in the -X direction from the -Z direction end portion of the first vertical portion 72i. Additionally, the first groove portion 72f has a horizontal portion 72k, which extends in the +X direction from the -Z direction end portion of the first inclined portion 72j. Furthermore, the first groove portion 72f has a second vertical portion 72m, which extends in the -Z direction from the +X direction end portion of the horizontal portion 72k. In addition, the first groove 72f has a first outlet end 72n, which is connected from the -Z direction to the end of the second vertical part 72m in the -Z direction and from the +Z direction to the second internal flow path 72c.

[0085] The second groove 72g connects the third internal flow path 72d and the fourth internal flow path 72e, guiding ink between the third internal flow path 72d and the fourth internal flow path 72e. For example... Figure 8 As shown, the second groove portion 72g has a second inlet end portion 72p that connects to the third internal flow path 72d in the +Z direction. Additionally, the second groove portion 72g has a third vertical portion 72q that extends from the second inlet end portion 72p in the +Z direction. Furthermore, the second groove portion 72g has a second inclined portion 72r that displaces in the +X direction from the +Z end portion of the third vertical portion 72q toward the +Z direction. Additionally, the second groove portion 72g has a fourth vertical portion 72s that extends from the +Z end portion of the second inclined portion 72r in the +Z direction. Furthermore, the second groove portion 72g has a second outlet end portion 72t that connects to the +Z end portion of the fourth vertical portion 72s in the +Z direction and connects to the fourth internal flow path 72e in the -Z direction.

[0086] In this embodiment, such as Figure 8 As shown, the first internal flow path 72b and the fourth internal flow path 72e are arranged at the same position in the Z direction. In addition, both the first internal flow path 72b and the fourth internal flow path 72e are arranged further in the -X direction than the central position of the first flow path plate 72 in the X direction.

[0087] Furthermore, the second internal flow path 72c and the third internal flow path 72d are arranged at the same position in the Z direction. The second internal flow path 72c is arranged further in the +X direction than the center position of the first flow path plate 72 in the X direction. The third internal flow path 72d is arranged further in the -X direction than the center position of the first flow path plate 72 in the X direction.

[0088] Furthermore, the first inlet end 72h and the second outlet end 72t are arranged at the same position in the Z direction. In addition, both the first inlet end 72h and the second outlet end 72t are arranged further in the -X direction than the central position of the first flow path plate 72 in the X direction.

[0089] Furthermore, the first vertical portion 72i and the fourth vertical portion 72s are generally positioned at the same location in the Z direction. In addition, both the first vertical portion 72i and the fourth vertical portion 72s are positioned further in the -X direction than the central position of the first flow path plate 72 in the X direction.

[0090] Furthermore, the first inclined portion 72j and the second inclined portion 72r are generally located at the same position in the Z direction. In addition, both the first inclined portion 72j and the second inclined portion 72r are located further in the -X direction than the central position of the first flow path plate 72 in the X direction.

[0091] Furthermore, the -X direction end of the horizontal portion 72k is positioned further in the -X direction than the center position in the X direction of the first flow path plate 72. The +X direction end of the horizontal portion 72k is positioned further in the +X direction than the center position in the X direction of the first flow path plate 72.

[0092] Furthermore, the second vertical portion 72m and the first outlet end 72n are positioned further in the +X direction than the center position of the first flow path plate 72 in the X direction. Additionally, the second inlet end 72p and the third vertical portion 72q are positioned further in the -X direction than the center position of the first flow path plate 72 in the X direction.

[0093] The flow path cover 73 is a plate component that engages with the surface of the first flow path plate 72 in the -Y direction. Viewed from the Y direction, the width of the flow path cover 73 in the X direction is the same as the width of the first flow path plate 72 in the X direction. Furthermore, the end of the flow path cover 73 in the +Z direction is positioned at the same location as the end of the first flow path plate 72 in the +Z direction in the Z direction. The height of the flow path cover 73 in the Z direction is set such that the flow path cover 73 can cover the overall dimensions of the first groove 72f and the second groove 72g.

[0094] The inlet port 74 is provided by protruding in the +Z direction from the surface (upper surface) of the first flow path plate 72 facing the +Z direction. The inlet port 74 and the ink supply tube 21 (see reference) Figure 1 The inlet port 74 is connected to the first internal flow path 72b of the first flow path plate 72 in the +Z direction. The inlet port 74 guides the ink supplied from the ink supply tube 21 to the first internal flow path 72b.

[0095] The discharge port 75 is provided by protruding in the +Z direction from the surface (upper surface) of the first flow path plate 72 facing the +Z direction. The discharge port 75 and the ink discharge tube 22 (see reference) Figure 1The discharge port 75 is connected to the fourth internal flow path 72e of the first flow path plate 72 in the +Z direction. The discharge port 75 guides the ink discharged from the fourth internal flow path 72e to the ink discharge tube 22.

[0096] In this embodiment, both the first internal flow path 72b and the fourth internal flow path 72e are disposed further in the -X direction than the central position of the first flow path plate 72 in the X direction. Therefore, both the inflow port 74 connected to the first internal flow path 72b and the discharge port 75 connected to the fourth internal flow path 72e are disposed further in the -X direction than the central position of the first flow path plate 72 in the X direction.

[0097] Thus, in this embodiment, an inflow port 74 is provided, which is connected to the upstream end (the end in the +Z direction) of the first internal flow path 72b, and an outlet port 75 is connected to the downstream end (the end in the +Z direction) of the fourth internal flow path 72e. In addition, the inflow port 74 and the outlet port 75 are arranged adjacent to each other in the X direction (first direction) further away from the center of the flow path member 44 in the -X direction (one side).

[0098] Furthermore, by changing the positions of the first internal flow path 72b and the fourth internal flow path 72e, or the positions and shapes of the first groove 72f and the second groove 72g, it is also possible to arrange the inflow port 74 and the discharge port 75 adjacent to each other in the X direction (first direction) in a direction closer to the +X direction (the other side) than the center of the flow path component 44.

[0099] Inlet manifold 76 (reference) Figure 5 The inlet manifold 76 is joined together with the two head chips 43 and the second flow path plate 78 at their +X direction ends, and inserted into the +X direction insertion portion 72a of the first flow path plate 72. The inlet manifold 76 has an inlet protrusion 76a that inserts into the insertion portion 72a from the -Z direction. Additionally, the inlet manifold 76 has an inlet base 76b, which is connected to the inlet protrusion 76a from the -Z direction and joined to the two head chips 43 and the +X direction ends of the second flow path plate 78. Furthermore, an internal flow path 76c is provided in the inlet manifold 76. The internal flow path 76c has openings at the +Z direction end of the inlet protrusion 76a and the -X direction surface of the inlet base 76b.

[0100] like Figure 5As shown, the outlet manifold 77 is connected to the -X direction ends of the two head chips 43 and the second flow path plate 78, and is inserted into the -X direction insertion portion 72a of the first flow path plate 72. The outlet manifold 77 has an outlet protrusion 77a that inserts into the insertion portion 72a from the -Z direction. In addition, the outlet manifold 77 has an outlet base 77b, which is connected to the outlet protrusion 77a from the -Z direction and is connected to the -X direction ends of the two head chips 43 and the second flow path plate 78. Furthermore, an internal flow path 77c is provided in the outlet manifold 77. The internal flow path 77c has an opening at the +Z direction end of the outlet protrusion 77a and the +X direction surface of the outlet base 77b.

[0101] The second flow path board 78 is clamped between the two head chips 43 in the Y direction. The second flow path board 78 is integrally formed from a single component. Figure 5 As shown, the second flow path plate 78 is a rectangular plate with a long side along the X direction and a short side along the Z direction. Viewed from the Y direction, the shape of the second flow path plate 78 is substantially the same as that of the cover plate 49.

[0102] A head chip 43 is bonded to the first main surface 78a of the second flow path board 78 facing the +Y direction. Another head chip 43 is bonded to the second main surface 78b of the second flow path board 78 facing the -Y direction.

[0103] The second flow path plate 78 is formed of a material that has insulation properties and a thermal conductivity greater than that of the cover plate 49. For example, if the cover plate 49 is formed of silicon, the second flow path plate 78 is preferably formed of silicon or carbon. This mitigates temperature variations in the cover plate 49 among the individual head chips 43. Consequently, it mitigates temperature variations in the actuator plate 48 among the individual head chips 43, achieving uniform ink temperature. This, in turn, achieves uniform ink ejection speed, improving printing stability.

[0104] The second flow path plate 78 has an inlet flow path 78c that communicates with the common ink chamber 63 and an outlet flow path 78d that communicates with the return plate 45 (described later) circulation path 80. The +X end of each inlet flow path 78c opens at one end face of the second flow path plate 78 in the +X direction. Each inlet flow path 78c extends in a straight line after being inclined such that it is lower towards the -X direction from one end face of the second flow path plate 78 in the +X direction, and then bends towards the other end face of the second flow path plate 78 in the -X direction. The inlet flow path 78c connects to the inlet manifold 76 at the other end face of the second flow path plate 78 in the +X direction. Each inlet flow path 78c is spaced apart along the Y direction between one head chip 43 and another head chip 43.

[0105] like Figure 5As shown, one end of each outlet flow path 78d opens at the other end face of the second flow path plate 78 in the -X direction. Each outlet flow path 78d extends in a straight line in the +X direction after being bent downwards in a crank-like manner from the other end face of the second flow path plate 78 in the -X direction. The outlet flow path 78d connects to the outlet manifold 77 at the other end face of the second flow path plate 78 in the -X direction. Each outlet flow path 78d is arranged spaced apart in the Y direction between one head chip 43 and another head chip 43.

[0106] like Figure 3 and Figure 4 As shown, the heat transfer plate 79 is engaged with the -Y direction surface of the flow path cover 73. The heat transfer plate 79 abuts against the plurality of drive ICs 84 (described later) of the substrate unit 47 from the +Y direction. The heat transfer plate 79 thermally connects the drive ICs 84 relative to the flow path cover 73. Figure 4 As shown, the heat transfer plate 79 is formed as a rectangular plate with the thickness direction in the Y direction and the long side direction in the X direction. Viewed from the Y direction, the heat transfer plate 79 is arranged to overlap with the horizontal portion 72k of the first groove portion 72f.

[0107] In this embodiment, an ink flow path (hereinafter referred to as ink flow path 100) is provided in the flow path component 44. (See reference) Figure 9 The ink flow path 100 is formed including a first internal flow path 72b, a second internal flow path 72c, a third internal flow path 72d, a fourth internal flow path 72e, a first groove 72f, a second groove 72g, an internal flow path 76c, an internal flow path 77c, an inlet flow path 78c, and an outlet flow path 78d. In this embodiment, in the flow direction of ink in the ink flow path 100, the ink is arranged from the upstream side in the following order: first internal flow path 72b, first groove 72f, second internal flow path 72c, internal flow path 76c, inlet flow path 78c, outlet flow path 78d, internal flow path 77c, third internal flow path 72d, second groove 72g, and fourth internal flow path 72e.

[0108] Figure 9 This is a schematic diagram of an inkjet head 5 including an ink flow path 100. In this embodiment, the ink flow path 100 includes an inflow path 101, a cooling path 102, a connecting path 103, a guiding path 104, and an outflow path 105. Furthermore, in... Figure 9 In the following figures, the flow of ink will be represented by the reference symbol L.

[0109] The inflow path 101 guides ink flowing into the flow path component 44 from outside the flow path component 44 (ink supply pipe 21) via the inflow port 74. The inflow path 101 connects the inflow port 74 to the cooling flow path 102. The upstream end of the inflow path 101 is connected to the inflow port 74. The downstream end of the inflow path 101 is connected to the cooling flow path 102. In this embodiment, the inflow path 101 includes a first internal flow path 72b (see reference 102). Figure 8 ), the first inlet end 72h of the first groove 72f (refer to) Figure 8 ), the first vertical part 72i of the first groove 72f (refer to) Figure 8 ) and the first inclined portion 72j of the first groove 72f (refer to Figure 8 It is formed by ).

[0110] Cooling flow path 102 guides ink from the -X direction (the other side) in the X direction (first direction) to the +X direction (one side), cooling multiple driver ICs 84. Cooling flow path 102 connects inflow flow path 101 to connecting flow path 103. The upstream end of cooling flow path 102 is connected to inflow flow path 101. The downstream end of cooling flow path 102 is connected to connecting flow path 103. Cooling flow path 102 includes a horizontal portion 72k of the first groove portion 72f (refer to...). Figure 8 This is formed by [the following]. In this embodiment, viewed from the Y direction, the cooling flow path 102 is configured to overlap with a plurality of drive ICs 84 and heat transfer plates 79.

[0111] The connecting flow path 103 guides ink between the cooling flow path 102 and the guiding flow path 104. The connecting flow path 103 connects the cooling flow path 102 and the guiding flow path 104. The upstream end of the connecting flow path 103 is connected to the cooling flow path 102. The downstream end of the connecting flow path 103 is connected to the guiding flow path 104. The connecting flow path 103 includes a second vertical portion 72m (see reference) of the first groove portion 72f. Figure 8 ), the first outlet end 72n of the first groove 72f (refer to) Figure 8 It is formed by the second internal flow path 72c and the internal flow path 76c.

[0112] The guide flow path 104 guides ink from the +X direction (one side) in the X direction to the -X direction (the other side). The guide flow path 104 is connected to multiple ejection channels 50 (pressure chambers) of the head chip 43. The guide flow path 104 connects the connecting flow path 103 to the discharge flow path 105. The upstream end of the guide flow path 104 is connected to the connecting flow path 103. The downstream end of the guide flow path 104 is connected to the discharge flow path 105. The guide flow path 104 includes an inlet flow path 78c (see reference). Figure 5 ) and outlet flow path 78d (refer to) Figure 5 It is formed by ).

[0113] Furthermore, as described above, in the inlet flow path 78c, there is a portion that slopes downwards from one end face of the second flow path plate 78 in the +X direction, becoming increasingly lower towards the -X direction. In this portion, ink flows at an angle relative to the horizontal direction, becoming increasingly lower towards the -X direction. Additionally, in the outlet flow path 78d, there is a portion that bends downwards in a crank-like shape from the other end face of the second flow path plate 78 in the -X direction. In this portion, ink flows upwards from the bottom. However, these portions are only a small part of the inlet flow path 78c and the outlet flow path 78d. Therefore, the ink in the inlet flow path 78c and the outlet flow path 78d primarily flows from the +X direction to the -X direction.

[0114] Furthermore, regarding the guiding flow path 104, the +X direction end of the inlet flow path 78c is connected to the connecting flow path 103, and the -X direction end of the outlet flow path 78d is connected to the discharge flow path 105. Moreover, a head chip 43 is disposed between the inlet flow path 78c and the outlet flow path 78d. That is, the guiding flow path 104 is primarily a flow path that guides ink from the +X direction to the -X direction, but in its actual construction, it is not a simply straight flow path. However, in... Figure 9 For ease of explanation, the guide flow path 104 is schematically shown as a flow path diagram, with the +X direction end connected to the connecting flow path 103 and the -X direction end connected to the discharge flow path 105. Furthermore, in... Figure 9 In the accompanying diagrams, the guiding flow path is also schematically shown as a flow path.

[0115] That is, the ink flow in the guiding flow path 104, which includes the inlet flow path 78c and the outlet flow path 78d, is mainly from the +X direction to the -X direction. Furthermore, the guiding flow path 104 may also partially include ink flow in a direction different from the main flow direction. Similarly, the cooling flow path 102 may also partially include ink flow in a direction different from the main flow direction (from the -X direction to the +X direction).

[0116] The discharge path 105 guides ink discharged through the discharge port 75 to the outside of the flow path component 44 (ink discharge tube 22). The discharge path 105 connects the guide path 104 to the discharge port 75. The upstream end of the discharge path 105 is connected to the guide path 104. The downstream end of the discharge path 105 is connected to the discharge port 75. In this embodiment, the discharge path 105 includes an internal flow path 77c (see...). Figure 8 ), the third internal flow path 72d (refer to Figure 8 ), 72g of the second groove (refer to) Figure 8 ) and the fourth internal flow path 72e (refer to Figure 8 It is formed by ).

[0117] Thus, in this embodiment, the ink flow path 100 is provided with an inflow path 101, a guide path 104, a cooling path 102, and an outflow path 105 arranged in series. Furthermore, in the ink flow direction, they are arranged in the order of inflow path 101, cooling path 102, guide path 104, and outflow path 105.

[0118] Ink flowing in ink flow path 100 is guided from inlet port 74 to inlet flow path 101 and supplied to cooling flow path 102. In cooling flow path 102, the ink is guided horizontally from the -X direction towards the +X direction. The ink flowing in cooling flow path 102 heats up as it moves downstream (i.e., in the +X direction) through heat exchange with drive IC 84. Ink discharged from cooling flow path 102 is supplied to guide flow path 104 via connecting flow path 103. In guide flow path 104, the ink is guided horizontally from the +X direction towards the -X direction.

[0119] The head chip 43 is heated by the heat generated by the actuator plate 48. Therefore, the ink flowing in the guide flow path 104 is heated as it moves downstream (i.e., in the -X direction) through heat exchange with the head chip 43. Ink discharged from the guide flow path 104 is guided to the discharge port 75 via the discharge flow path 105.

[0120] Thus, the ink heats up in the cooling flow path 102 and the guiding flow path 104. In this embodiment, the ink flows in opposite directions in these cooling flow paths 102 and guiding flow paths 104. That is, the ink flows from the -X direction to the +X direction in the cooling flow path 102, and the ink flows from the +X direction to the -X direction in the guiding flow path 104.

[0121] [Return to board 45] A return plate 45 is disposed at the opening end of the ejection channel 50 in the head chip 43. The return plate 45 is a spacer plate between the opening ends of the ejection channels 50 in one head chip 43 and another head chip 43 and the upper end of the nozzle plate 46. In the return plate 45, a plurality of circulation paths 80 are formed connecting the ejection channels 50 of each head chip 43 to the outlet flow path 78d.

[0122] [Nozzle Plate 46] The nozzle plate 46 is attached to the lower end face of the return plate 45. Multiple nozzle holes 81 are arranged on the nozzle plate 46, extending through the nozzle plate 46 in the Z direction. Each nozzle hole 81 is connected to a corresponding ejection channel 50 of the head chip 43 via a circulation path 80.

[0123] On the other hand, each non-discharge channel 51 is not connected to the nozzle orifice 81, but is covered from below by the return plate 45.

[0124] [Substrate Unit 47] like Figure 3 As shown, the substrate unit 47 is supported on the surface of the flow path cover 73 in the -Y direction. The substrate unit 47 includes a driving substrate 82, a wiring substrate 83, and a driving IC 84 (driving control unit). The driving substrate 82 and the wiring substrate 83 are each flexible printed circuit boards, which are formed with wiring patterns on a base film.

[0125] The driver substrate 82 has a package portion 82a and a chip connection portion 82b. Alternatively, a rigid substrate or the like can be used for the package portion 82a. The package portion 82a is supported by a flow path cover 73. Multiple driver ICs 84 are packaged on the +Y direction surface of the package portion 82a. Furthermore, the package portion 82a is connected to an interface (not shown). This interface may, for example, supply power from the outside of the inkjet head 5 to the substrate unit 47 or transmit and receive control signals.

[0126] like Figure 4 As shown, the chip connection portion 82b extends from the package portion 82a in the -Z direction. Figure 6 , Figure 7 As shown, the -Z direction end of the chip connection portion 82b is connected to a head chip 43.

[0127] like Figure 6 , Figure 7 As shown, the wiring substrate 83 connects the package portion 82a to another header chip 43. Specifically, the +Z direction end of the wiring substrate 83 is connected to the package portion 82a, and the -Z direction end is connected to the other header chip 43.

[0128] In this embodiment, five driver ICs 84 are provided. Alternatively, the number of driver ICs 84 can be two to four. Furthermore, there can be six or more driver ICs 84. Figure 4 As shown in the diagram, these driver ICs 84 are arranged in a straight line along the X direction.

[0129] These are driver ICs 84 and driver head chips 43. Furthermore, in this embodiment, a configuration in which all driver ICs 84 are packaged together on a single driver substrate 82 will be described. However, for example, driver substrates may be provided corresponding to each individual driver IC 84.

[0130] Furthermore, in the following description, the multiple driver ICs 84 arranged in a straight line along the X direction from the -X direction toward the +X direction will be referred to as the first driver IC 84a, the second driver IC 84b, the third driver IC 84c, the fourth driver IC 84d, and the fifth driver IC 84e. That is, the driver IC 84 located closest to the -X direction is the first driver IC 84a, and the driver IC 84 located closest to the +X direction is the fifth driver IC 84e.

[0131] These first driver ICs 84a, 84b, 84c, 84d, and 84e abut against the heat transfer plate 79 from the -Y direction and are thermally connected to the flow path component 44. That is, in this embodiment, the substrate unit 47 encapsulates a plurality of driver ICs 84 arranged along the X direction and is thermally connected to the flow path component 44.

[0132] [Nozzle Protector 42] like Figure 4 As shown, the nozzle protector 42 is connected to the base member 40 in the -Z direction and covers the base member 40 in the -Z direction. An exposure hole 42a is formed in the nozzle protector 42, exposing the nozzle plate 46 to the outside. The nozzle hole 81 communicates with the outside of the inkjet head 5 through the exposure hole 42a. Alternatively, the nozzle protector 42 may be equipped with a cap that, when filling with ink or when the printing operation stops, seals against the nozzle protector 42 in the -Z direction, closing the nozzle hole 81.

[0133] [Printer operation methods] Next, the operation method of printer 1 when using printer 1 to record text or graphics on the recording medium P will be described.

[0134] Furthermore, as the initial state, in Figure 1 The four ink tanks 4 shown are each fully filled with ink of a different color. In addition, the ink in the ink tanks 4 is filled into the inkjet head 5 via the ink circulation mechanism 6.

[0135] like Figure 1 As shown, in the initial state, if printer 1 is operated, the rollers 11 and 12 of the conveying mechanisms 2 and 3 rotate, thereby conveying the recording medium P between these rollers 11 and 12 in the conveying direction (X direction). Simultaneously with the conveying of the recording medium P, drive motor 35 rotates pulley 32, causing the annular belt 34 to move. Thus, carriage 30 is guided by guide rails 28 and 29 and simultaneously reciprocates along the Y direction.

[0136] Furthermore, during the reciprocating movement of the carriage 30, by appropriately ejecting four colors of ink from each inkjet head 5 to the recording medium P, it is possible to record text or images on the recording medium P.

[0137] Here, the activities of each inkjet head 5 will be explained.

[0138] In the longitudinally circulating inkjet head 5 of the side-shot type as in this embodiment, firstly, by making Figure 2The pressurizing pump 24 and suction pump 25 shown operate to allow ink to flow within the circulation path 23. In this case, ink flowing through the ink supply pipe 21 flows into the first flow path plate 72 through the inlet port 74. Ink guided inside the first flow path plate 72 flows into the respective inlet flow paths 78c of the second flow path plate 78 through the inlet manifold 76. The ink flowing into each inlet flow path 78c, after passing through each common ink chamber 63, is supplied to each ejection channel 50 through the slit 64. The ink flowing into each ejection channel 50 collects in the outlet flow path 78d through the circulation path 80 of the return plate 45, and is then supplied back to the first flow path plate 72 through the outlet manifold 77. The ink resupplying to the first flow path plate 72 is discharged into the ink discharge pipe 22 through the discharge port 75. The ink discharged into the ink discharge pipe 22 returns to the ink tank 4 and is then supplied back to the ink supply pipe 21. This causes the ink to circulate between the inkjet head 5 and the ink tank 4.

[0139] Then, if via carriage 30 (refer to) Figure 1 When the actuator plate 48 of this embodiment begins to reciprocate, a driving voltage is applied to the common electrode 56 and the individual electrode 58 via the substrate unit 47. At this time, the driving voltage is applied with the individual electrode 58 at the driving potential Vdd and the common electrode 56 at the reference potential GND. As a result, thickness slip deformation occurs in the two driving walls that define the ejection channel 50, and these two driving walls deform in a way that protrudes towards the non-ejection channel 51 side. That is, in this embodiment, the actuator plate 48 has two polarized piezoelectric substrates stacked along the thickness direction (Y direction), and therefore, by applying a driving voltage, it bends and deforms in a V-shape with the middle position in the Y direction of the driving wall as the center. As a result, the ejection channel 50 deforms as if bulging.

[0140] If the volume of the ejection channel 50 increases due to the deformation of the two drive walls, the ink in the common ink chamber 63 is guided into the ejection channel 50 through the slit 64. The ink guided into the ejection channel 50 then becomes a pressure wave and propagates inside the ejection channel 50. When this pressure wave reaches the nozzle orifice 81, the drive voltage applied between the common electrode 56 and the individual electrode 58 is zero.

[0141] As a result, the drive wall returns to its original state, and the temporarily enlarged volume of the ejection channel 50 returns to its original volume. This action increases the internal pressure of the ejection channel 50, pressurizing the ink. Consequently, ink can be ejected from the nozzle orifice 81. At this time, the ink is ejected as droplets as it passes through the nozzle orifice 81. Thus, text or images can be recorded on the recording medium P as described above.

[0142] Furthermore, the operation of the inkjet head 5 is not limited to the above-described methods. For example, it can be configured such that the drive wall, in its normal state, deforms inward toward the ejection channel 50, making the ejection channel 50 appear concave inward. In this case, this can be achieved by making the voltage applied between the common electrode 56 and the individual electrode 58 a voltage opposite in sign to the voltage described above, or by reversing the polarization direction of the actuator plate 48 without changing the sign of the voltage. Alternatively, the ejection channel 50 can be deformed in a way that first bulges outward, and then concave inward, thereby increasing the pressure of the ink during ejection.

[0143] The inkjet head 5 of this embodiment, as described above, includes a head chip 43, a flow path component 44, and a substrate unit 47. The head chip 43 has a plurality of ejection channels 50 arranged sequentially from the +X direction in the X direction to the -X direction, ejecting ink from inside the ejection channels 50. The flow path component 44 has a guide flow path 104 that guides the ink from the +X direction in the X direction to the -X direction, and the guide flow path 104 is connected to each ejection channel 50. The substrate unit 47 encapsulates a plurality of driver ICs 84 arranged along the X direction and is thermally connected to the flow path component 44. Furthermore, the flow path component 44 has a cooling flow path 102 that guides the ink from the -X direction in the X direction to the +X direction and cools the plurality of driver ICs 84.

[0144] The inkjet head 5 has two main heat sources: a head chip 43 with an ejection channel 50 for ink ejection, and multiple driver ICs 84. According to this embodiment, the inkjet head 5 has a guide flow path 104 in the flow path component 44 that connects to the ejection channel 50 of the head chip 43, which is one of these heat sources. Additionally, the flow path component 44 has a cooling flow path 102 that cools the multiple driver ICs 84, which are one of these heat sources.

[0145] In these guiding flow paths 104 and cooling flow paths 102, the ink flow direction in the guiding flow path 104 is opposite to the ink flow direction in the cooling flow path 102, which cools the driver IC 84. Therefore, in the guiding flow path 104, the -X direction side in the X direction becomes relatively hot compared to the +X direction side. On the other hand, in the cooling flow path 102, the +X direction side in the X direction becomes relatively hot compared to the -X direction side.

[0146] As a result, the temperature distribution of the inkjet head 5 is more uniform when observed as a whole, compared to the case where the ink flow direction in the guide flow path 104 and the ink flow direction in the cooling flow path 102 are the same. This uniform heat distribution throughout the inkjet head 5 leads to uniform temperature of the ink supplied to each ejection channel 50, and also uniform viscosity of the ink in each ejection channel 50. Therefore, stable ejection performance can be obtained. Furthermore, the uniform heat distribution throughout the inkjet head 5 reduces the maximum achievable temperature of the driver IC 84, enabling stable operation of the driver IC 84.

[0147] Furthermore, in the inkjet head 5 of this embodiment, the flow path component 44 is provided with an inflow flow path 101 and an outflow flow path 105. The inflow flow path 101 guides ink flowing in from the outside. The outflow flow path 105 guides ink being discharged to the outside. In addition, the inflow flow path 101, the guide flow path 104, the cooling flow path 102, and the outflow flow path 105 are arranged in series.

[0148] According to the inkjet head 5 of this embodiment, the ink supplied to the ejection channel 50 flows through the cooling flow path 102. Therefore, compared to the case where the guide flow path 104 and the cooling flow path 102 are arranged in parallel between the inflow flow path 101 and the outlet flow path 105, pressure dispersion throughout the ink flow path can be prevented. Therefore, if the pressure at the inlet of the inflow flow path 101 and the outlet of the outlet flow path 105 is set to the same conditions as in the case where the guide flow path 104 and the cooling flow path 102 are arranged in parallel between the inflow flow path 101 and the outlet flow path 105, the ink flow rate increases. Consequently, the cooling efficiency in the cooling flow path 102 can be improved.

[0149] Furthermore, in the inkjet head 5 of this embodiment, the ink is arranged in the order of inflow path 101, cooling path 102, guide path 104, and discharge path 105. Generally, the driver IC 84 is at a higher temperature than the head chip 43. According to the inkjet head 5 of this embodiment, the ink flows into the cooling path 102 before flowing into the guide path 104. Therefore, compared to the case where the ink, whose temperature has risen while flowing into the guide path 104, flows into the cooling path 102, ink at a lower temperature can be used to cool the driver IC 84. Therefore, the cooling efficiency of the driver IC 84 can be improved.

[0150] Furthermore, the inkjet head 5 of this embodiment includes an inlet port 74 and an outlet port 75. The inlet port 74 is connected to the upstream end of the inlet flow path 101. The outlet port 75 is connected to the downstream end of the outlet flow path 105. The inlet port 74 and the outlet port 75 are arranged adjacent to each other in the X direction on the -X direction side, which is closer to the center of the flow path component 44.

[0151] According to the inkjet head 5 of this embodiment, the ink supply tube 21 connected to the inlet port 74 and the ink discharge tube 22 connected to the outlet port 75 can be arranged close together. Therefore, compared with the case where the inlet port 74 and the outlet port 75 are arranged separately, the inlet port 74 and the outlet port 75 are less likely to obstruct other components.

[0152] Furthermore, ink flows from one direction in the cooling flow path 102 and from one direction in the guiding flow path 104. Therefore, when the guiding flow path 104 and the cooling flow path 102 are arranged in series, the length of the flow path for ink flow can be minimized.

[0153] Furthermore, the printer 1 of this embodiment includes the inkjet head 5 described above. Therefore, it becomes a printer with stable output performance.

[0154] (A variation of the first embodiment) Figure 10 This is a schematic diagram of an ink flow path 100 including a modified example of the inkjet head 5 of this first embodiment. In this modified example, the flow of ink in the ink flow path 100 is reversed compared to the example described above. That is, in this modified example, the inflow path 101 is used as the discharge path, and the discharge path 105 is used as the inflow path. In addition, the inflow port 74 is used as the discharge port, and the discharge port 75 is used as the inflow port.

[0155] Furthermore, in the following description, the discharge flow path 105 used as an inflow flow path in this modified example will be referred to as the inflow flow path 106, and the inflow flow path 101 used as a discharge flow path in this modified example will be referred to as the discharge flow path 107. In addition, the discharge port 75 used as an inflow port in this modified example will be referred to as the inflow port 85, and the inflow port 74 used as a discharge port in this modified example will be referred to as the discharge port 86.

[0156] The inflow path 106 guides ink flowing into the flow path component 44 from outside (ink supply tube 21) via the inflow port 85. The inflow path 106 connects the inflow port 85 to the guide path 104. The upstream end of the inflow path 106 is connected to the inflow port 85. The downstream end of the inflow path 106 is connected to the guide path 104.

[0157] The guide flow path 104 guides ink from the -X direction (one side) to the +X direction (the other side) in the X direction. The guide flow path 104 connects the inflow flow path 106 to the connecting flow path 103. The upstream end of the guide flow path 104 is connected to the inflow flow path 106. The downstream end of the guide flow path 104 is connected to the connecting flow path 103.

[0158] Connecting flow path 103 guides ink between guiding flow path 104 and cooling flow path 102. Connecting flow path 103 connects cooling flow path 102 and guiding flow path 104. The upstream end of connecting flow path 103 is connected to guiding flow path 104. The downstream end of connecting flow path 103 is connected to cooling flow path 102.

[0159] Cooling path 102 guides ink from the +X direction (the other side) to the -X direction (one side) in the X direction, cooling multiple driver ICs 84. Cooling path 102 connects connecting path 103 to discharge path 107. The upstream end of cooling path 102 is connected to connecting path 103. The downstream end of cooling path 102 is connected to discharge path 107.

[0160] The discharge path 107 guides ink discharged through the discharge port 86 to the outside of the flow path component 44 (ink discharge tube 22). The discharge path 107 connects the cooling path 102 to the discharge port 86. The upstream end of the discharge path 107 is connected to the cooling path 102. The downstream end of the discharge path 107 is connected to the discharge port 86.

[0161] Thus, in this embodiment, the ink flow path 100 includes an inflow path 106, a guide path 104, a cooling path 102, and an outflow path 107 arranged in series. Furthermore, in the ink flow direction, they are arranged in the order of inflow path 106, guide path 104, cooling path 102, and outflow path 107.

[0162] According to this modified example, the distance from the inflow path 106 to the ejection channel 50 is shorter than that in the case where a cooling path 102 is arranged between the inflow path 106 and the guide path 104. Therefore, the pressure loss up to the ejection channel 50 can be reduced, insufficient ink supply to the ejection channel 50 can be suppressed, and ink can be stably ejected from the ejection channel 50.

[0163] Furthermore, in this modified example, the ink flow direction in the guide flow path 104 is opposite to the ink flow direction in the cooling flow path 102, which cools the driver IC 84. In the guide flow path 104, the +X direction side in the X direction becomes relatively hot compared to the -X direction side. On the other hand, in the cooling flow path 102, the -X direction side in the X direction becomes relatively hot compared to the +X direction side.

[0164] As a result, the temperature distribution when viewed as a whole in the inkjet head 5 is more uniform compared to the case where the ink flow direction in the guide flow path 104 and the ink flow direction in the cooling flow path 102 are the same. Therefore, stable ejection performance can be obtained. In addition, the driver IC 84 can be driven stably.

[0165] (Second Implementation) Next, the second embodiment of this disclosure will be described. Furthermore, in this embodiment, the descriptions of parts that are the same as in the first embodiment described above will be omitted or simplified.

[0166] Figure 11 This is a schematic diagram of the inkjet head 5A of this embodiment, including the ink flow path 100A. In this embodiment, the ink flow path 100A includes an inflow flow path 111, a partial cooling flow path 112 (second cooling flow path), a cooling flow path 113, a connecting flow path 114, a guiding flow path 115, and an outflow flow path 116.

[0167] Inflow path 111 guides ink flowing into flow path component 44 from outside (ink supply tube 21) via inflow port 74. Inflow path 111 connects inflow port 74 to a portion of cooling flow path 112. The upstream end of inflow path 111 is connected to inflow port 74. The downstream end of inflow path 111 is connected to a portion of cooling flow path 112.

[0168] In this embodiment, such as Figure 11 As shown, the inflow path 111 has a vertical flow path 111a extending from the inflow port 74 in the -Z direction and a separation flow path 111b (separation section) displaced from the downstream end of the vertical flow path 111a in the +X direction along the -Z direction. Figure 11 As shown, the separation flow path 111b is inclined relative to the vertical direction (Z direction) and separates from the discharge flow path 116 as it moves downward (downstream). Such an inflow flow path 111 can be provided, for example, by changing the shape of the first groove 72f in the first embodiment described above and using only a portion of the first groove 72f.

[0169] Partial cooling flow path 112 is a flow path that allows ink to flow from the +X direction in the X direction to the -X direction. This partial cooling flow path 112 cools a portion of the multiple driver ICs 84 located in the -X direction. In this embodiment, as... Figure 11 As shown, a portion of the cooling flow path 112 is arranged to overlap with the first driver IC 84a, the second driver IC 84b, and the third driver IC 84c when viewed from the Y direction, and cools the first driver IC 84a, the second driver IC 84b, and the third driver IC 84c. That is, the portion of the cooling flow path 112 cools the multiple driver ICs 84 sequentially from the driver IC 84 closest to the discharge flow path 116, and at least the driver IC 84 farthest from the discharge flow path 116 is not cooled.

[0170] A portion of the cooling flow path 112 connects the inflow flow path 111 to the cooling flow path 113. The upstream end of the portion of the cooling flow path 112 is connected to the inflow flow path 111. The downstream end of the portion of the cooling flow path 112 is connected to the upstream end of the cooling flow path 113. Such a portion of the cooling flow path 112 can be provided, for example, by changing the shape of the first groove 72f in the first embodiment described above, using only a portion of the first groove 72f.

[0171] Cooling path 113 guides ink from the -X direction to the +X direction in the X direction, cooling multiple driver ICs 84. Cooling path 113 connects a portion of cooling path 112 to connecting path 114. The upstream end of cooling path 113 is connected to a portion of cooling path 112. The downstream end of cooling path 113 is connected to connecting path 114.

[0172] Connecting flow path 114 guides ink between cooling flow path 113 and guiding flow path 115. Connecting flow path 114 connects cooling flow path 113 and guiding flow path 115. The upstream end of connecting flow path 114 is connected to cooling flow path 113. The downstream end of connecting flow path 114 is connected to guiding flow path 115.

[0173] Guide flow path 115 guides ink from the +X direction in the X direction to the -X direction. Guide flow path 115 is connected to multiple ejection channels 50 of head chip 43. Guide flow path 115 connects connection flow path 114 and discharge flow path 116. The upstream end of guide flow path 115 is connected to connection flow path 114. The downstream end of guide flow path 115 is connected to discharge flow path 116.

[0174] The discharge path 116 guides ink discharged through the discharge port 75 to the outside of the flow path component 44 (ink discharge tube 22). The discharge path 116 connects the guide path 115 to the discharge port 75. The upstream end of the discharge path 116 is connected to the guide path 115. The downstream end of the discharge path 116 is connected to the discharge port 75.

[0175] Thus, in the inkjet head 5A of this embodiment, the inflow flow path 111 has a separation flow path 111b that separates from the discharge flow path 116 as it moves downstream. In this inkjet head 5A of this embodiment, it is possible to suppress the ink flowing in the inflow flow path 111 from heating up due to the high temperature of the ink flowing in the discharge flow path 116. Therefore, compared to the case where the separation flow path 111b is not provided, supplying low-temperature ink to the cooling flow path 113 can improve the cooling efficiency of the driver IC 84.

[0176] Furthermore, in the inkjet head 5A of this embodiment, the inflow flow path 111 is provided with a partial cooling flow path 112 that allows ink to flow from the +X direction (one side) in the X direction to the -X direction (the other side). The partial cooling flow path 112 cools a portion of the multiple driver ICs 84 located in the -X direction. According to this inkjet head 5A of this embodiment, driver ICs 84 located at positions that are prone to heating due to the high temperature of ink flowing through the discharge flow path 116 can be locally cooled. Therefore, the maximum temperature reached by the driver ICs 84 can be further reduced.

[0177] (A variation of the second embodiment) Figure 12 This is a schematic diagram showing a modified example of the inkjet head 5A according to the second embodiment, including the ink flow path 100A. In this modified example, the flow of ink in the ink flow path 100A is reversed compared to the example described above. That is, in this modified example, the inflow path 111 is used as the discharge path, and the discharge path 116 is used as the inflow path. Furthermore, the inflow port 74 is used as the discharge port, and the discharge port 75 is used as the inflow port.

[0178] Furthermore, in the following description, the discharge flow path 116 used as an inflow flow path in this modified example will be referred to as the inflow flow path 117, and the inflow flow path 111 used as a discharge flow path in this modified example will be referred to as the discharge flow path 118. In addition, the discharge port 75 used as an inflow port in this modified example will be referred to as the inflow port 85, and the inflow port 74 used as a discharge port in this modified example will be referred to as the discharge port 86.

[0179] The inflow path 117 guides ink flowing into the flow path component 44 from the outside (ink supply tube 21) via the inflow port 85. The inflow path 117 connects the inflow port 85 to the guide path 115. The upstream end of the inflow path 117 is connected to the inflow port 85. The downstream end of the inflow path 117 is connected to the guide path 115.

[0180] The guide flow path 115 guides ink from the -X direction (one side) to the +X direction (the other side) in the X direction. The guide flow path 115 connects the inflow flow path 117 to the connecting flow path 114. The upstream end of the guide flow path 115 is connected to the inflow flow path 117. The downstream end of the guide flow path 115 is connected to the connecting flow path 114.

[0181] Connecting flow path 114 guides ink between guiding flow path 115 and cooling flow path 113. Connecting flow path 114 connects cooling flow path 113 and guiding flow path 115. The upstream end of connecting flow path 114 is connected to guiding flow path 115. The downstream end of connecting flow path 114 is connected to cooling flow path 113.

[0182] Cooling path 113 guides ink from the +X direction (the other side) to the -X direction (one side) in the X direction, cooling multiple driver ICs 84. Cooling path 113 connects connection path 114 to a portion of cooling path 112. The upstream end of cooling path 113 is connected to connection path 114. The downstream end of cooling path 113 is connected to a portion of cooling path 112.

[0183] Part of the cooling path 112 guides the ink from the -X direction to the +X direction in the X direction, cooling a portion of the driver IC 84. Part of the cooling path 112 connects the cooling path 113 to the discharge path 118. The upstream end of the partial cooling path 112 is connected to the cooling path 113. The downstream end of the partial cooling path 112 is connected to the discharge path 118.

[0184] The discharge path 118 guides ink discharged through the discharge port 86 to the outside of the flow path component 44 (ink discharge tube 22). The discharge path 118 connects a portion of the cooling path 112 to the discharge port 86. The upstream end of the discharge path 118 is connected to the portion of the cooling path 112. The downstream end of the discharge path 118 is connected to the discharge port 86.

[0185] Thus, in this embodiment, the ink flow path 100A includes an inflow path 117, a guide path 115, a cooling path 113, and an outflow path 118 arranged in series. Furthermore, in the ink flow direction, they are arranged in the order of inflow path 117, guide path 115, cooling path 113, and outflow path 118.

[0186] According to this variation, the distance from the inflow path 117 to the ejection channel 50 is shorter than in the case where a cooling path 113 or part of a cooling path 112 is arranged between the inflow path 117 and the guide path 115. Therefore, the pressure loss up to the ejection channel 50 can be reduced, insufficient ink supply to the ejection channel 50 can be suppressed, and ink can be stably ejected from the ejection channel 50.

[0187] Furthermore, in this modified example, the ink flow direction in the guide flow path 115 is opposite to the ink flow direction in the cooling flow path 113, which cools the driver IC 84. In the guide flow path 115, the +X direction side in the X direction becomes relatively hot compared to the -X direction side. On the other hand, in the cooling flow path 113, the -X direction side in the X direction becomes relatively hot compared to the +X direction side.

[0188] As a result, the temperature distribution under the overall observation of the inkjet head 5A is more uniform compared to the case where the ink flow direction in the guide flow path 115 and the ink flow direction in the cooling flow path 113 are the same. Therefore, stable ejection performance can be obtained. In addition, the driver IC 84 can be driven stably.

[0189] (Third Implementation) Next, the third embodiment of this disclosure will be described. Furthermore, in this embodiment, the descriptions of parts that are the same as in the first embodiment described above will be omitted or simplified.

[0190] Figure 13 This is a schematic diagram of the inkjet head 5B of this embodiment, including the ink flow path 100B. In the inkjet head 5B of this embodiment, the inlet port 74 is disposed at the end of the flow path component 44 in the +X direction, and the outlet port 75 is disposed at the end of the flow path component 44 in the -X direction.

[0191] In this embodiment, the ink flow path 100B includes an inflow flow path 121, a first connecting flow path 122, a cooling flow path 123, a second connecting flow path 124, a guiding flow path 125, and an outflow flow path 126.

[0192] The inflow path 121 guides ink flowing into the flow path component 44 from the outside (ink supply tube 21) via the inflow port 74. The inflow path 121 connects the inflow port 74 to the first connecting flow path 122 and the guiding flow path 125. The upstream end of the inflow path 121 is connected to the inflow port 74. The downstream end of the inflow path 121 is connected to the guiding flow path 125. Additionally, a portion of the inflow path 121 is connected to the first connecting flow path 122.

[0193] Furthermore, in this embodiment, the inflow path 121 is provided on the +Y direction side of the flow path component 44. Such an inflow path 121 can be formed, for example, by forming a groove on the +Y direction surface of the first flow path plate 72 and covering the groove with a cover.

[0194] The first connecting flow path 122 connects the inflow flow path 121 to the cooling flow path 123. The upstream end of the first connecting flow path 122 is connected to the middle part of the inflow flow path 121. The downstream end of the first connecting flow path 122 is bent and connected to the cooling flow path 123. This first connecting flow path 122 mainly guides the ink from the +X direction to the -X direction.

[0195] Cooling path 123 guides ink from the -X direction to the +X direction in the X direction, cooling multiple driver ICs 84. Cooling path 123 connects the first connection path 122 and the second connection path 124. The upstream end of cooling path 123 is connected to the first connection path 122. The downstream end of cooling path 123 is connected to the second connection path 124.

[0196] The second connecting flow path 124 connects the cooling flow path 123 to the discharge flow path 126. The upstream end of the second connecting flow path 124 is bent and connected to the cooling flow path 123. The downstream end of the second connecting flow path 124 is connected to the middle part of the discharge flow path 126. This second connecting flow path 124 mainly guides the ink from the +X direction to the -X direction.

[0197] These first connecting flow paths 122, cooling flow paths 123 and second connecting flow paths 124 can be formed, for example, by forming grooves on the surface of the first flow path plate 72 in the -Y direction and covering the grooves with a cover.

[0198] The guide path 125 guides ink from the +X direction in the X direction to the -X direction. The guide path 125 is connected to multiple ejection channels 50 of the head chip 43. The guide path 125 connects the inflow path 121 to the outflow path 126. The upstream end of the guide path 125 is connected to the inflow path 121. The downstream end of the guide path 125 is connected to the outflow path 126.

[0199] The discharge path 126 guides ink discharged through the discharge port 75 to the outside of the flow path component 44 (ink discharge tube 22). The discharge path 126 connects the guide path 125 and the second connecting path 124 to the discharge port 75. The upstream end of the discharge path 126 is connected to the guide path 125. The downstream end of the discharge path 126 is connected to the discharge port 75. Additionally, a portion of the discharge path 126 is connected to the second connecting path 124.

[0200] Furthermore, in this embodiment, the discharge flow path 126 is provided on the +Y direction side of the flow path component 44. Such a discharge flow path 126 can be formed, for example, by forming a groove on the surface of the first flow path plate 72 in the +Y direction and covering the groove with a cover.

[0201] Thus, in the inkjet head 5B of this embodiment, the flow path component 44 is provided with an inflow flow path 121 for guiding ink flowing in from the outside and an outflow flow path 126 for guiding ink discharging to the outside. In addition, a guide flow path 125 and a cooling flow path 123 are arranged in parallel between the inflow flow path 121 and the outflow flow path 126.

[0202] According to this embodiment of the inkjet head 5B, the distance from the inflow path 121 to the ejection channel 50 is shorter than that in the case where a cooling path 123 is arranged between the inflow path 121 and the guide path 125. Therefore, the pressure loss up to the ejection channel 50 can be reduced, insufficient ink supply to the ejection channel 50 can be suppressed, and ink can be stably ejected from the ejection channel 50.

[0203] Furthermore, in the inkjet head 5B of this embodiment, the flow path component 44 is provided with: a first connecting flow path 122, which is disposed between the upstream end of the inflow flow path 121 and the cooling flow path 123; and a second connecting flow path 124, which is disposed between the downstream end of the cooling flow path 123 and the discharge flow path 126. Additionally, the first connecting flow path 122 and the second connecting flow path 124 guide ink from the +X direction in the X direction to the -X direction.

[0204] The inkjet head 5B according to this embodiment has a meandering flow path consisting of a first connecting flow path 122, a cooling flow path 123, and a second connecting flow path 124. Therefore, ink flows over a large area of ​​the flow path component 44, which can further homogenize the overall heat distribution of the inkjet head 5B.

[0205] (A variation of the third embodiment) Figure 13 This is a schematic diagram showing a modified example of the inkjet head 5B according to the third embodiment, including the ink flow path 100B. In this modified example, the flow of ink in the ink flow path 100B is reversed compared to the example described above. That is, in this modified example, the inflow path 121 is used as the discharge path, and the discharge path 126 is used as the inflow path. Furthermore, the inflow port 74 is used as the discharge port, and the discharge port 75 is used as the inflow port.

[0206] Furthermore, in the following description, the discharge flow path 126 used as an inflow flow path in this modified example will be referred to as the inflow flow path 127, and the inflow flow path 121 used as a discharge flow path in this modified example will be referred to as the discharge flow path 128. In addition, the discharge port 75 used as an inflow port in this modified example will be referred to as the inflow port 85, and the inflow port 74 used as a discharge port in this modified example will be referred to as the discharge port 86.

[0207] The inflow path 127 guides ink flowing into the flow path component 44 from the outside (ink supply tube 21) via the inflow port 85. The inflow path 127 connects the guide path 125 and the second connecting path 124 to the inflow port 85. The upstream end of the inflow path 127 is connected to the inflow port 85. The downstream end of the inflow path 127 is connected to the guide path 125. Additionally, a portion of the inflow path 127 is connected to the second connecting path 124.

[0208] The guide path 125 guides the ink from the -X direction to the +X direction in the X direction. The guide path 125 connects the inflow path 127 and the outflow path 128. The upstream end of the guide path 125 is connected to the inflow path 127. The downstream end of the guide path 125 is connected to the outflow path 128.

[0209] The second connecting flow path 124 connects the inflow flow path 127 to the cooling flow path 123. The upstream end of the second connecting flow path 124 is connected to the middle part of the inflow flow path 127. The downstream end of the second connecting flow path 124 is bent and connected to the cooling flow path 123. This second connecting flow path 124 mainly guides the ink from the -X direction to the +X direction.

[0210] Cooling path 123 guides ink from the +X direction to the -X direction in the X direction, cooling multiple driver ICs 84. Cooling path 123 connects the second connection path 124 to the first connection path 122. The upstream end of cooling path 123 is connected to the second connection path 124. The downstream end of cooling path 123 is connected to the first connection path 122.

[0211] The first connecting flow path 122 connects the cooling flow path 123 to the discharge flow path 128. The upstream end of the first connecting flow path 122 is bent and connected to the cooling flow path 123. The downstream end of the first connecting flow path 122 is connected to the middle part of the discharge flow path 128. This first connecting flow path 122 mainly guides the ink from the -X direction to the +X direction.

[0212] The discharge path 128 guides ink discharged through the discharge port 86 to the outside of the flow path component 44 (ink discharge tube 22). The discharge path 128 connects the discharge port 86 to the first connecting path 122 and the guiding path 125. The upstream end of the discharge path 128 is connected to the guiding path 125. The downstream end of the discharge path 128 is connected to the discharge port 86. Additionally, a portion of the discharge path 128 is connected to the first connecting path 122.

[0213] In this modified example, the distance from the inflow path 127 to the ejection channel 50 is also shorter than in the case where a cooling path 123 is arranged between the inflow path 127 and the guide path 125. Therefore, the pressure loss up to the ejection channel 50 can be reduced, insufficient ink supply to the ejection channel 50 can be suppressed, and ink can be stably ejected from the ejection channel 50.

[0214] Furthermore, in this modified example, the ink flow direction in the guide flow path 125 is opposite to the ink flow direction in the cooling flow path 123, which cools the driver IC 84. In the guide flow path 125, the +X direction side in the X direction becomes relatively hot compared to the -X direction side. On the other hand, in the cooling flow path 123, the -X direction side in the X direction becomes relatively hot compared to the +X direction side.

[0215] As a result, the temperature distribution under overall observation of the inkjet head 5B is more uniform compared to the case where the ink flow direction in the guide flow path 125 and the ink flow direction in the cooling flow path 123 are the same. Therefore, stable ejection performance can be obtained. In addition, the driver IC 84 can be driven stably.

[0216] Furthermore, in this modified example, a meandering flow path is formed, consisting of a first connecting flow path 122, a cooling flow path 123, and a second connecting flow path 124. Therefore, the ink flows over a large area of ​​the flow path component 44, which can further homogenize the overall heat distribution of the inkjet head 5B.

[0217] (Fourth implementation) Next, the fourth embodiment of this disclosure will be described. Furthermore, in this embodiment, the descriptions of parts that are the same as in the first embodiment described above will be omitted or simplified.

[0218] Figure 15 This is a schematic diagram of the inkjet head 5C of this embodiment, including the ink flow path 100C. In the inkjet head 5C of this embodiment, the inlet port 74 is disposed at the end of the flow path component 44 in the +X direction, and the outlet port 75 is disposed at the end of the flow path component 44 in the -X direction.

[0219] In this embodiment, the ink flow path 100C includes an inflow flow path 131, an upper connecting flow path 132 (fourth connecting flow path), a cooling flow path 133, a lower connecting flow path 134 (third connecting flow path), a guide flow path 135, and an outflow flow path 136.

[0220] The inflow path 131 guides ink flowing into the flow path component 44 from the outside (ink supply tube 21) via the inflow port 74. The inflow path 131 connects the inflow port 74 to the upper connecting flow path 132. The upstream end of the inflow path 131 is connected to the inflow port 74. The downstream end of the inflow path 131 is connected to the upper connecting flow path 132.

[0221] Furthermore, in this embodiment, the inflow path 131 is provided on the +Y direction side of the flow path component 44. Such an inflow path 131 can be formed, for example, by forming a groove on the +Y direction surface of the first flow path plate 72 and covering the groove with a cover.

[0222] The upper connecting flow path 132 connects the inflow flow path 131 to the cooling flow path 133. The upstream end of the upper connecting flow path 132 is connected to the inflow flow path 131. The downstream end of the upper connecting flow path 132 is bent and connected to the cooling flow path 133. This upper connecting flow path 132 mainly guides the ink from the +X direction to the -X direction.

[0223] Cooling path 133 guides ink from the -X direction to the +X direction in the X direction, cooling multiple driver ICs 84. Cooling path 133 connects the upper connection path 132 and the lower connection path 134. The upstream end of cooling path 133 is connected to the upper connection path 132. The downstream end of cooling path 133 is connected to the lower connection path 134.

[0224] The lower connecting flow path 134 connects the cooling flow path 133 to the guiding flow path 135. The upstream end of the lower connecting flow path 134 is connected to the cooling flow path 133. The downstream end of the lower connecting flow path 134 is connected to the guiding flow path 135. This lower connecting flow path 134 guides the ink from the +Z direction to the -Z direction.

[0225] Furthermore, it is also possible to configure the lower connecting flow path 134 to guide ink from the +X direction to the -X direction in a part or in whole. In such a case, ink can also be guided along the Z direction in the upper connecting flow path 132.

[0226] These upper connecting flow paths 132, cooling flow paths 133, and lower connecting flow paths 134 can be formed, for example, by forming grooves on the surface of the first flow path plate 72 in the -Y direction and covering the grooves with a cover.

[0227] The guide flow path 135 guides ink from the +X direction in the X direction to the -X direction. The guide flow path 135 is connected to multiple ejection channels 50 of the head chip 43. The guide flow path 135 connects the lower connecting flow path 134 to the discharge flow path 136. The upstream end of the guide flow path 135 is connected to the lower connecting flow path 134. The downstream end of the guide flow path 135 is connected to the discharge flow path 136.

[0228] The discharge path 136 guides ink discharged through the discharge port 75 to the outside of the flow path component 44 (ink discharge tube 22). The discharge path 136 connects the guide path 135 to the discharge port 75. The upstream end of the discharge path 136 is connected to the guide path 135. The downstream end of the discharge path 136 is connected to the discharge port 75.

[0229] Furthermore, in this embodiment, the discharge flow path 136 is provided on the +Y direction side of the flow path component 44. Such a discharge flow path 136 can be formed, for example, by forming a groove on the surface of the first flow path plate 72 in the +Y direction and covering the groove with a cover.

[0230] Thus, in the inkjet head 5C of this embodiment, the inflow path 131, the cooling path 133, the guide path 135, and the discharge path 136 are arranged in series. Therefore, compared to the case where the guide path 135 and the cooling path 133 are arranged in parallel between the inflow path 131 and the discharge path 136, pressure dispersion throughout the ink flow path can be prevented. Therefore, if the pressure at the inlet of the inflow path 131 and the outlet of the discharge path 136 is set to the same conditions as when the guide path 135 and the cooling path 133 are arranged in parallel between the inflow path 131 and the discharge path 136, the ink flow rate increases. Consequently, the cooling efficiency in the cooling path 133 can be improved.

[0231] Furthermore, in the inkjet head 5C of this embodiment, the flow path component 44 is provided with: a lower connecting flow path 134, which connects the guide flow path 135 to the cooling flow path 133; and an upper connecting flow path 132, which connects to the end opposite to the end of the cooling flow path 133 and the end connected to the lower connecting flow path 134. The upper connecting flow path 132 primarily guides ink from the +X direction in the X direction to the -X direction. Based on this, the inkjet head 5C of this embodiment forms a meandering flow path composed of the upper connecting flow path 132, the cooling flow path 133, and the lower connecting flow path 134. Therefore, ink flows over a large area of ​​the flow path component 44, further homogenizing the overall heat distribution of the inkjet head 5C.

[0232] (A variation of the fourth embodiment) Figure 16 This is a schematic diagram showing a modified example of the inkjet head 5C according to the fourth embodiment, including the ink flow path 100C. In this modified example, the flow of ink in the ink flow path 100C is reversed compared to the example described above. That is, in this modified example, the inflow path 131 is used as the discharge path, and the discharge path 136 is used as the inflow path. In addition, the inflow port 74 is used as the discharge port, and the discharge port 75 is used as the inflow port.

[0233] Furthermore, in the following description, the discharge flow path 136 used as an inflow flow path in this modified example will be referred to as the inflow flow path 137, and the inflow flow path 131 used as a discharge flow path in this modified example will be referred to as the discharge flow path 138. In addition, the discharge port 75 used as an inflow port in this modified example will be referred to as the inflow port 85, and the inflow port 74 used as a discharge port in this modified example will be referred to as the discharge port 86.

[0234] The inflow path 137 guides ink flowing into the flow path component 44 from outside (ink supply tube 21) via the inflow port 85. The inflow path 137 connects the inflow port 85 to the guide path 135. The upstream end of the inflow path 137 is connected to the inflow port 85. The downstream end of the inflow path 137 is connected to the guide path 135.

[0235] The guide flow path 135 guides ink from the -X direction to the +X direction in the X direction. The guide flow path 135 is connected to multiple ejection channels 50 of the head chip 43. The guide flow path 135 connects the inflow flow path 137 to the lower connection flow path 134. The upstream end of the guide flow path 135 is connected to the inflow flow path 137. The downstream end of the guide flow path 135 is connected to the lower connection flow path 134.

[0236] The lower connecting flow path 134 connects the guiding flow path 135 to the cooling flow path 133. The upstream end of the lower connecting flow path 134 is connected to the guiding flow path 135. The downstream end of the lower connecting flow path 134 is connected to the cooling flow path 133. This lower connecting flow path 134 guides the ink from the -Z direction to the +Z direction.

[0237] Cooling path 133 guides ink from the +X direction to the -X direction in the X direction, cooling multiple driver ICs 84. Cooling path 133 connects the lower connection path 134 to the upper connection path 132. The upstream end of cooling path 133 is connected to the lower connection path 134. The downstream end of cooling path 133 is connected to the upper connection path 132.

[0238] The upper connecting flow path 132 connects the cooling flow path 133 to the discharge flow path 138. The upstream end of the upper connecting flow path 132 is bent and connected to the cooling flow path 133. The downstream end of the upper connecting flow path 132 is connected to the discharge flow path 138. This upper connecting flow path 132 mainly guides the ink from the -X direction to the +X direction.

[0239] The discharge path 138 guides ink discharged through the discharge port 86 to the outside of the flow path component 44 (ink discharge tube 22). The discharge path 138 connects the discharge port 86 to the upper connecting path 132. The upstream end of the discharge path 138 is connected to the upper connecting path 132. The downstream end of the discharge path 138 is connected to the discharge port 86.

[0240] According to this modified example, the distance from the inflow path 137 to the outlet channel 50 is shorter than in the case where an upper connecting path 132, a cooling path 133, and a lower connecting path 134 are arranged between the inflow path 137 and the guide path 135. Therefore, the pressure loss up to the outlet channel 50 can be reduced, insufficient ink supply to the outlet channel 50 can be suppressed, and ink can be stably ejected from the outlet channel 50.

[0241] Furthermore, in this modified example, the ink flow direction in the guide flow path 135 is opposite to the ink flow direction in the cooling flow path 133, which cools the driver IC 84. In the guide flow path 135, the +X direction side in the X direction becomes relatively hot compared to the -X direction side. On the other hand, in the cooling flow path 133, the -X direction side in the X direction becomes relatively hot compared to the +X direction side.

[0242] As a result, the temperature distribution under overall observation of the inkjet head 5C is more uniform compared to the case where the ink flow direction in the guide flow path 135 and the ink flow direction in the cooling flow path 133 are the same. Therefore, stable ejection performance can be obtained. In addition, the driver IC 84 can be driven stably.

[0243] Furthermore, in this modified example, a meandering flow path is formed, consisting of an upper connecting flow path 132, a cooling flow path 133, and a lower connecting flow path 134. Therefore, the ink flows over a large area of ​​the flow path component 44, which can further homogenize the overall heat distribution of the inkjet head 5C.

[0244] Furthermore, the scope of this disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of this disclosure.

[0245] For example, in the above embodiments, printer 1 is illustrated as an example of a liquid jetting device, but it is not limited to a printer. For example, it could also be a fax machine or an on-demand printer.

[0246] In the above embodiments, a configuration in which the inkjet head moves relative to the recorded medium during printing (a so-called reciprocating print machine) has been described as an example, but it is not limited to this configuration. The configuration involved in this disclosure can also be adopted in a configuration in which the recorded medium moves relative to the inkjet head while the inkjet head is fixed (a so-called fixed-head print machine).

[0247] In the above embodiments, the case where the recording medium P is paper has been described, but the configuration is not limited to this. The recording medium P is not limited to paper, but may also be a metal material, a resin material, or even food, etc.

[0248] In the above embodiments, the configuration of the liquid jet head mounted on the liquid jet recording device has been described, but the configuration is not limited to this. That is, the liquid jetted from the liquid jet head is not limited to the liquid hitting the recording medium, but may also be, for example, a medicine liquid prepared in a dispensing solution, or a food additive such as seasonings or spices added to food, or a fragrance sprayed into the air.

[0249] Furthermore, while the above embodiments have described a side-ejection head chip, the method is not limited thereto. For example, this disclosure can also be applied to so-called side-ejection type head chips that eject ink from the central portion of the ejection channel in an extending direction.

[0250] Alternatively, this disclosure can also be applied to so-called top-ejection type head chips in which the direction of pressure applied to the ink and the direction of ink ejection are the same.

[0251] In the above embodiments, a configuration in which the Z direction is aligned with the direction of gravity has been described, but it is not limited to this configuration; the Z direction may also be aligned with the horizontal direction.

[0252] In the above embodiments, a configuration in which two head chips are mounted on one ejection module has been described, but it is not limited to this configuration. That is, it is also possible to have a configuration in which one head chip is mounted on one ejection module.

[0253] In the above embodiments, a configuration in which a portion of the ink discharged from the ink tank is returned to the ink tank (i.e., the configuration of ink circulation) has been described. However, it is also possible for the ink discharged from the ink tank and supplied to the head chip not to be returned to the ink tank.

[0254] Furthermore, without departing from the spirit of this disclosure, the constituent elements in the above embodiments can be appropriately replaced with well-known constituent elements, and the above variations can also be appropriately combined.

[0255] Symbol Explanation 1. Printer (Liquid Jet Recording Device) 5. Inkjet head (liquid jet head) 5A Inkjet Head (Liquid Jet Head) 5B Inkjet Head (Liquid Jet Head) 5C inkjet head 43-head chip (ejection section) 44 Flow path components 47. Substrate Unit (Circuit Board) 50. Discharge Channel (Pressure Chamber) 74 Inflow Port 75 Discharge Port 84 Driver IC (Drive Control Unit) 85 Inflow Port 86 Discharge Port 100 ink flow paths 100A Ink Flow Path 100B Ink Flow Path 100C Ink Flow Path 101 Inflow path 102 Cooling flow path 103 Connecting Flow Paths 104 Guided Flow Path 105 Discharge flow path 106 Inflow path 107 Discharge flow path 111 Inflow path 111a Vertical flow path 111b Separation Flow Path (Separation Section) 112 Partial cooling flow path (2nd cooling flow path) 113 Cooling flow path 114 Connecting Flow Paths 115 Guided Flow Path 116 Discharge flow path 117 Inflow path 118 Discharge flow path 121 Inflow path 122 First connection path 123 cooling flow path 124 Second connection flow path 125 Guided Flow Path 126 Discharge flow path 127 Inflow path 128 Discharge flow path 131 Inflow path 132 Upper connection flow path (4th connection flow path) 133 cooling flow path 134 Lower connection flow path (3rd connection flow path) 135 Guided Flow Path 136 Discharge flow path 137 Inflow path 138 Drainage flow path.

Claims

1. A liquid injection head, comprising: The jetting section is provided with a plurality of pressure chambers arranged sequentially from one side to the other in a first direction, and the liquid inside the pressure chambers is jetted out. A flow path component, provided with a guide flow path for guiding liquid from one side to the other side in the first direction, and the guide flow path is connected to each of the pressure chambers; and A circuit board, which encapsulates a plurality of drive control units arranged along the first direction and is thermally connected to the flow path component. The flow path component is provided with a cooling flow path that guides the liquid from the other side of the first direction to the first side and cools the plurality of drive control units.

2. The liquid injection head according to claim 1, wherein, The flow path component is provided with an inflow flow path for guiding the liquid flowing in from the outside and an outflow flow path for guiding the liquid discharging out from the outside. The guiding flow path and the cooling flow path are arranged in parallel between the inflow flow path and the discharge flow path.

3. The liquid injection head according to claim 2, wherein, The flow path component includes: a first connecting flow path disposed between the upstream end of the inflow flow path and the upstream end of the cooling flow path; and a second connecting flow path disposed between the downstream end of the cooling flow path and the discharge flow path. The first connecting flow path and the second connecting flow path guide the liquid from one side of the first direction to the other side.

4. The liquid injection head according to claim 1, wherein, The flow path component is provided with an inflow flow path for guiding the liquid flowing in from the outside and an outflow flow path for guiding the liquid discharging out from the outside. The inflow path, the guide path, the cooling path, and the discharge path are arranged in series.

5. The liquid injection head according to claim 4, wherein, The flow paths are arranged in the following order: inflow path, cooling path, guiding path, and discharge path.

6. The liquid injection head according to claim 4, wherein, The flow paths are arranged in the following order: inflow path, guide path, cooling path, and discharge path.

7. The liquid injection head according to claim 5 or 6, wherein, The flow path component includes: a third connecting flow path that connects the guiding flow path to the cooling flow path; and a fourth connecting flow path that connects to the end of the cooling flow path opposite to the end connected to the third connecting flow path. At least one of the third and fourth connecting flow paths guides the liquid from one side of the first direction to the other side in at least a portion.

8. The liquid injection head according to any one of claims 2, 4 to 6, wherein, It has an inflow port connected to the upstream end of the inflow path and an outlet port connected to the downstream end of the outlet path. The inflow port and the outlet port are arranged adjacent to each other on one side or the other side of the flow path component in the first direction, closer to the center than the center of the flow path component.

9. The liquid injection head according to claim 8, wherein, The inflow path has a separation section that separates from the outflow path as it moves downstream.

10. The liquid injection head according to any one of claims 2 to 6, wherein, The flow path component is provided with a second cooling flow path that allows the liquid to flow from one side to the other in the first direction. The second cooling flow path cools a portion of the drive control units located on the other side of the plurality of drive control units.

11. A liquid jet recording device comprising a liquid jet head according to any one of claims 1 to 10.

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