Liquid ejection head

Abstract

The present application provides a liquid ejection head capable of realizing miniaturization and simplification of a cooling structure of a heating portion. The liquid ejection head of an embodiment includes a liquid ejection portion, a plurality of heating portions, and a cooling flow path portion. The liquid ejection portion has a plurality of nozzle rows. The heating portions correspond to the plurality of nozzle rows. The cooling flow path portion has a plurality of flow path portions that are less than the number of the nozzle rows and through which cooling water flows and abuts against the plurality of heating portions, respectively.

Description

Technical Field

[0001] Embodiments of the present invention relate to liquid ejection heads. Background Technology

[0002] In some liquid ejector heads, the driver IC must be oriented outwards due to the component structure. When such a liquid ejector head is constructed as a multi-nozzle array, a water-cooling circulation path is provided on the back of the opposing driver IC, and a heat-conducting plate is mounted on the outside for heat dissipation.

[0003] However, the recent demand for high-speed printing with high productivity has led to an increase in the heat generated by the driver IC during operation. Therefore, there are concerns that conventional heat dissipation structures may not achieve adequate cooling. Improving cooling efficiency raises concerns about increasing the size of the cooling system, the liquid nozzle, or making the cooling system more complex and costly. These factors would burden the printer unit, thus requiring simplification as much as possible. Summary of the Invention

[0004] The technical problem that the invention aims to solve

[0005] The technical problem to be solved by the present invention is to provide a liquid nozzle that can achieve a miniaturized and simplified cooling structure for the heating element.

[0006] Solutions for solving technical problems

[0007] The liquid ejector head of this embodiment includes a liquid ejection section, multiple heating sections, and a cooling flow path section. The liquid ejection section has multiple rows of nozzles. The heating sections correspond to the multiple rows of nozzles. The cooling flow path section has multiple flow path sections, fewer in number than the number of nozzle rows, for cooling water to flow through and abutting against the multiple heating sections. Attached Figure Description

[0008] Figure 1 This is a perspective view showing the structure of the liquid ejector head according to the relevant embodiment.

[0009] Figure 2 This is an exploded perspective view showing the structure of the liquid ejector head according to the relevant embodiment.

[0010] Figure 3 This is a side view showing the structure of the liquid ejector head according to the embodiment.

[0011] Figure 4 This is a cross-sectional view showing the structure of the liquid ejector head according to the relevant embodiment.

[0012] Figure 5 This is a diagram showing the structure of the liquid ejector head according to the embodiment from the nozzle plate side.

[0013] Figure 6 This is a perspective view showing the structure of the head body and manifold unit of the liquid ejector head according to a partial cross-section of the embodiment.

[0014] Figure 7 This is a cross-sectional view showing the structure of the head body and manifold unit in the relevant implementation method.

[0015] Figure 8 This is a cross-sectional view showing the structure of the head body and manifold unit in the relevant implementation method.

[0016] Figure 9 This is a diagram showing the structure of the head body of the relevant implementation method, with a portion omitted.

[0017] Figure 10 This is an exploded perspective view showing the structure of the cooling flow path unit according to the relevant implementation method.

[0018] Figure 11 This is an explanatory diagram showing the results of analytical simulation of the liquid nozzle of the relevant embodiment and the liquid nozzle of the relevant comparative example.

[0019] Figure 12 This is an explanatory diagram showing the results of analytical simulation of the liquid nozzle of the relevant embodiment and the liquid nozzle of the relevant comparative example.

[0020] Figure 13 This is an explanatory diagram showing the structure of the liquid ejection device according to the relevant embodiments.

[0021] Explanation of reference numerals in the attached figures

[0022] 1…Liquid nozzle; 2…Liquid ejection device; 11…Head body; 12…Manifold unit; 13…Cooling flow path unit; 14…Circuit board; 15…Cover plate; 111…Base plate; 112…Frame; 113…Actuator; 114…Nozzle plate; 115…Mask plate; 116…Common liquid chamber; 121…Manifold; 122…Top plate; 123…Ink supply pipe; 124…Ink discharge pipe; 125…First cooling water supply pipe; 126…First cooling water discharge pipe; 127…Damper; 128…Bypass flow path; 131…Cooling flow path section; 132…Cooling water top plate; 133…Second cooling water top plate; 134… Second cooling water supply pipe; 141… Wiring film; 142… Driver IC; 143… Printed wiring board; 1111… Supply port; 1112… Discharge port; 1131… Pressure chamber; 1133… Wall; 1141… Nozzle; 1142… Nozzle array; 1151… Window; 1161… First common liquid chamber; 1162… Second common liquid chamber; 1163… Third common liquid chamber; 1211… Supply path; 1212… Discharge path; 1213… First cooling flow path; 1214… First manifold; 1215… Second manifold; 1311… Branch flow path; 1312… …Second cooling flow path; 1313…Merging flow path; 1314…Cooling manifold; 1315…Cover plate; 1316…Cooling block; 2001…Conveying path; 2111…Housing; 2112…Media supply unit; 2113…Image forming unit; 2114…Media discharge unit; 2115…Conveying device; 2116…Cooling device; 2117…Maintenance device; 2118…Control unit; 2120…Support unit; 2130…Head unit; 2132…Supply box; 2134…Pump; 2135…Connecting flow path; 12111…Top section; 13121…Flow path section; 13122…Single row Cooling flow path section; 13123… Multi-row cooling flow path section; 13141… Opening; 13142… Groove; 13151… Opening; 13161… Tube section; 13162… Rib section; 13163… Groove; 21121… Paper feed box; 21141… Paper discharge tray; 21161… Cooling water tank; 21162… Cooling circuit; 21181… CPU; 21201… Conveyor belt; 21202… Support plate; 21203… Belt roller; 21211~21218… Guide plate pair; 21221~21228… Conveyor roller; 131221… Flow path; 131231… Flow path. Detailed Implementation

[0023] Below, refer to Figures 1 to 13 The liquid nozzle 1 and the liquid ejection device 2 using the liquid nozzle 1 will be described in relation to the embodiments. Figure 1 This is a perspective view showing the structure of the liquid nozzle 1 according to the relevant embodiment, omitting the cover plate 15. Figure 2This is an exploded perspective view showing the structure of the liquid ejector head 1, omitting the cover plate 15. Figure 3 This is a side view showing the structure of the liquid ejector head 1. Figure 4 This is a cross-sectional view showing the structure of the liquid ejector head 1, omitting the cover plate 15.

[0024] Figure 5 This is a diagram showing the structure of the liquid ejector head 1 from the nozzle plate 114 side. Figure 6 This is a perspective view showing the structure of the head body 11 and manifold unit 12 of the liquid ejector head 1 in partial cross-section. Figure 7 This is a cross-sectional view showing the structure of the head body 11 and the manifold unit 12. Figure 8 It is a cross-sectional view showing the enlarged structure of the head body 11 and the manifold unit 12.

[0025] Figure 9 This is a diagram that omits a portion of the structure of the head body 11. Figure 10 This is an exploded perspective view showing the structure of the cooling flow path unit 13. Figure 11 and Figure 12 This is an explanatory diagram showing the temperature of the cooled driver IC142 as the result of an analytical simulation of the liquid nozzle 1 of the relevant embodiment and the liquid nozzle of the relevant comparative example. Figure 13 This is an explanatory diagram showing the structure of the liquid ejection device 2 according to the relevant embodiment. Figure 2 In the image, a dashed arrow represents an example of cooling water flow.

[0026] exist Figures 1 to 10 The figure shows the mutually orthogonal X-axis, Y-axis, and Z-axis. In the following description, the direction along the X-axis is referred to as the first direction X, the direction along the Y-axis as the second direction Y, and the direction along the Z-axis as the third direction Z. Furthermore, for ease of explanation, the structures are appropriately enlarged, reduced, or omitted in the figures.

[0027] Liquid ejector head 1 is, for example, set in Figure 13 The inkjet head of the liquid ejection device 2, such as the inkjet recording device, is shown. The liquid ejection head 1 is provided in the head unit 2130, which includes a supply box 2132, which serves as a liquid collection section, provided in the liquid ejection device 2.

[0028] The liquid nozzle 1 is supplied with liquid ink stored in the supply tank 2132. The liquid nozzle 1 can be either a non-circulating type (where the ink does not circulate) or a circulating type (where the ink circulates). In this embodiment, a non-circulating type is used as an example for explanation. Furthermore, the liquid nozzle 1 is connected to a cooling device 2116 provided in the liquid dispensing device 2, and is supplied with cooling liquid (cooling water) for temperature control of the heating element and the ink. The liquid nozzle 1 and the cooling device 2116 together constitute a water-cooled circulation structure.

[0029] like Figures 1 to 4 As shown, the liquid ejector head 1 includes a head body 11, a manifold unit 12, a cooling flow path unit 13, a circuit board 14, and a cover plate 15. For example, the liquid ejector head 1 is a side-firing, four-row integrated head with two sets of head bodies 11, and each head body 11 has a pair of actuators 113.

[0030] The head body 11 ejects liquid. (Example) Figures 3 to 9 As shown, the head body 11 includes a base plate 111, a frame 112, an actuator 113, a nozzle plate 114, and a mask plate 115. Furthermore, the head body 11 has a common liquid chamber 116. In this embodiment, an example with two actuators 113 in one head body 11 will be described.

[0031] like Figures 7 to 9 As shown, the base plate 111 is formed into a rectangular plate shape, for example, from a ceramic material. The base plate 111 is, for example, formed into a rectangle that is longer in one direction (first direction X). Figure 9 As shown, the base plate 111 has a single supply port 1111 and one or more discharge ports 1112. A pair of actuators 113 are provided on the base plate 111, and wiring patterns for driving the actuators 113 are formed. The supply port 1111 and the discharge port 1112 are through holes that pass through the two main surfaces of the base plate 111.

[0032] A single supply port 1111 is provided, for example, in the common liquid chamber 116 opposite to the first common liquid chamber 1161 described later. The supply port 1111 is, for example, an elongated hole along the length direction (first direction X) of the first common liquid chamber 1161. The supply port 1111 is, for example, a rectangular shape along one direction, or an elongated hole with semi-circular ends and the same width. The width of the supply port 1111 along its length is, for example, greater than or less than the width (length) of the actuator 113 along its length, and is set to be the same length as the range (full nozzle range) of the pressure chamber 1131 formed by the actuator 113 that drives the ink during normal ink ejection.

[0033] The discharge outlet 1112 is provided in two locations, for example, opposite to at least one of the two third common liquid chambers 1163 described later, in the common liquid chamber 116. For example, as Figure 9 As shown, the outlet 1112 is disposed on the base plate 111 in such a way that it is located adjacent to the end of one of the third common liquid chambers 1163 in the longitudinal direction of the pair of actuators 113. Alternatively, the outlet 1112 may be provided in two of each of the two third common liquid chambers 1163 of the common liquid chamber 116.

[0034] like Figure 9 As shown, the frame 112 is fixed to one main surface of the base plate 111 by adhesive or the like. The frame 112 surrounds the supply port 1111, multiple discharge ports 1112, and actuator 113 provided on the base plate 111.

[0035] For example, the frame 112 is formed as a rectangular frame that is longer in one direction (first direction X), thereby forming an opening that is longer in one direction along the length of the frame 112. A pair of actuators 113, a supply port 1111 and two discharge ports 1112 are arranged in the opening of the frame 112.

[0036] The actuator 113 is formed as a plate that is longer in one direction (first direction X). A pair of actuators 113 are bonded to the mounting surface of the base plate 111. Figure 9 As shown, a pair of actuators 113 are arranged in two rows on the base plate 111, separated by a supply port 1111, along a short side direction (second direction Y) orthogonal to the length direction of the actuators 113. The actuators 113 are disposed within the opening of the frame 112 and are bonded to the main surface of the base plate 111. As a specific example, the actuators 113 are formed by bonding two rectangular plates of piezoelectric material, which are longer in one direction, opposite each other with opposite polarization directions. Here, the piezoelectric material is, for example, PZT (lead zirconate titanate). The actuators 113 are bonded to the mounting surface of the base plate 111, for example, using a thermosetting epoxy resin adhesive.

[0037] The actuator 113, for example, has a plurality of pressure chambers 1131 arranged at equal intervals along its length (first direction X). On the main surface side of the actuator 113 opposite to the base plate 111 side, a plurality of grooves are formed along the length of the actuator 113, and these grooves form the pressure chambers 1131. In other words, the actuator 113 has a plurality of walls 1133 arranged at equal intervals along its length, with grooves formed therebetween. The plurality of walls 1133 form the plurality of pressure chambers 1131 between adjacent walls. That is, the plurality of walls 1133 are partitions that separate the plurality of pressure chambers 1131. Furthermore, the walls 1133 are piezoelectric elements that change the volume of the pressure chambers 1131 by applying a driving voltage.

[0038] The side of the actuator 113 opposite to the base plate 111 is bonded to the nozzle plate 114. Furthermore, the actuator 113 is formed with a wiring pattern for driving multiple pressure chambers 1131.

[0039] The pressure chamber 1131 is used to eject ink from the nozzle 1141 during operations such as printing performed by the liquid ejector head 1. In addition, this embodiment describes an example where the actuator 113 has multiple pressure chambers 1131, but it may also have a structure that has, for example, an air chamber that does not eject ink, arranged alternately with the multiple pressure chambers 1131.

[0040] like Figure 4 , Figure 5 , Figure 7 and Figure 8 As shown, the nozzle plate 114 is formed in a plate shape. The nozzle plate 114 is fixed to the main surface of the frame 112 opposite to the base plate 111 by an adhesive or the like. The nozzle plate 114 has a plurality of nozzles 1141 formed at positions opposite to the plurality of pressure chambers 1131. In this embodiment, the nozzle plate 114 has two rows of nozzles 1142 arranged in one direction (first direction X). In this embodiment, the liquid ejector head 1 has two sets of head bodies 11, so as... Figure 5 As shown, the liquid ejector head 1 has four rows of nozzles 1142.

[0041] The multiple nozzles 1141 opposite the multiple pressure chambers 1131 are holes for ejecting ink when the liquid ejector head 1 performs actions such as printing.

[0042] The mask 115 covers, for example, the main surface of the outer surface of the nozzle plate 114, the outer peripheral surface of the nozzle plate 114, the outer peripheral surface of the frame 112, and the outer peripheral surface of the base plate 111. Furthermore, the mask 115 covers the first manifold 1214 of the manifold unit 12, which will be described later.

[0043] like Figure 5 As shown, the mask 115 has a pair of windows 1151 that expose the nozzle array 1142, which is composed of a plurality of nozzles 1141 of a pair of nozzle plates 114 for ejecting liquid.

[0044] like Figure 9 As shown, the common liquid chamber 116 is connected to the supply port 1111. The common liquid chamber 116 is disposed around a pair of actuators 113. Specifically, the common liquid chamber 116 is connected to the primary and secondary sides of the plurality of pressure chambers 1131 of each actuator 113. Furthermore, the common liquid chamber 116 is connected to the discharge port 1112.

[0045] As a specific example, such as Figure 9As shown, the common liquid chamber 116 has a first common liquid chamber 1161 that is longer in one direction (first direction X), two second common liquid chambers 1162 that are longer in one direction (first direction X), and a third common liquid chamber 1163 that connects the two ends of the first common liquid chamber 1161 and the two ends of the two second common liquid chambers 1162. Furthermore, the common liquid chamber 116 connects the supply port 1111 and one side of the plurality of pressure chambers 1131 of the actuator 113 through the first common liquid chamber 1161, and connects the third common liquid chamber 1163 and the other side of the plurality of pressure chambers 1131 through the second common liquid chambers 1162.

[0046] A first common liquid chamber 1161 is formed between a pair of actuators 113. The first common liquid chamber 1161 forms a flow path for ink from the supply port 1111 to an opening on one side of one of the plurality of pressure chambers 1131 of each actuator 113. Furthermore, the first common liquid chamber 1161 forms a flow path for ink from the supply port 1111 to two third common liquid chambers 1163 at both ends along the length direction (first direction X) of the first common liquid chamber 1161 (actuator 113).

[0047] The second common liquid chamber 1162 is formed between each actuator 113 and the frame 112. The second common liquid chamber 1162 forms a flow path for ink from the third common liquid chamber 1163 to the opening on the other side of the plurality of pressure chambers 1131.

[0048] The third common liquid chamber 1163 is adjacent to both ends of the actuator 113 along its length. The third common liquid chamber 1163 connects to the first common liquid chamber 1161 and two second common liquid chambers 1162 at both ends of the pair of actuators 113 along their length. The third common liquid chamber 1163 forms a flow path for ink from the first common liquid chamber 1161 to a portion of the second common liquid chamber 1162 without passing through the multiple pressure chambers 1131 of each actuator 113. Furthermore, the third common liquid chamber 1163 forms a flow path for ink from the first common liquid chamber 1161 and the two second common liquid chambers 1162 to the discharge port 1112.

[0049] like Figures 1 to 8 As shown, the manifold unit 12 includes a manifold 121, a top plate 122, an ink supply pipe 123, an ink discharge pipe 124, a first cooling water supply pipe 125, a first cooling water discharge pipe 126, a damper 127, and a bypass flow path 128. The number of ink supply pipes 123 and ink discharge pipes 124 can be appropriately set. The number of ink supply pipes 123, ink discharge pipes 124, first cooling water supply pipes 125, and first cooling water discharge pipes 126 can also be appropriately set.

[0050] Manifold 121 is formed in a plate-like or block-like shape. For example... Figures 6 to 8As shown, the manifold 121 includes a supply path 1211 that is connected to the supply port 1111 of the base plate 111 to form a liquid supply flow path, a discharge path 1212 that is connected to the discharge port 1112 of the base plate 111 to form a liquid discharge path, and a first cooling flow path 1213 that forms a flow path for cooling fluid. Furthermore, the manifold 121 is connected to a pair of head bodies 11, thus having a pair of supply paths 1211 and a pair of discharge paths 1212.

[0051] One side of the manifold 121 is fixed to the main surface of the base plate 111. Furthermore, a top plate 122 is fixed to the main surface of the manifold 121 opposite to the main surface to which the base plate 111 is fixed. The manifold 121, ink supply pipe 123, ink discharge pipe 124, first cooling water supply pipe 125, and first cooling water discharge pipe 126 are, for example, fixed via the top plate 122.

[0052] Manifold 121 may include, for example, a first manifold 1214 and a second manifold 1215. Manifold 121 is formed by assembling the first manifold 1214 and the second manifold 1215 together.

[0053] The supply path 1211 is a cuboid liquid chamber formed by holes and grooves in the manifold 121, which is longer in one direction (first direction X). The supply path 1211 is fluidly connected to the ink supply pipe 123 and the supply port 1111 of the base plate 111.

[0054] For example, the supply path 1211 is a cuboid liquid chamber extending along the length of the actuator 113 and the supply port 1111. The supply path 1211 is the flow path for the liquid between the ink supply pipe 123 and the supply port 1111. The supply port 1111 is connected to one side of the supply path 1211, and a damper 127 is provided on the top portion 12111 on the other side of the supply path 1211.

[0055] The discharge path 1212 is a flow path formed by holes and grooves in the manifold 121. The discharge path 1212 fluidly connects, for example, the ink discharge pipe 124 and the two discharge ports 1112 of the base plate 111.

[0056] The first cooling flow path 1213 is a flow path formed by holes and grooves in the manifold 121. The first cooling flow path 1213 is fluidly connected to the first cooling water supply pipe 125 and the first cooling water discharge pipe 126. The first cooling flow path 1213 cools the head body 11, which serves as the liquid ejection section.

[0057] The primary and secondary sides of the first cooling flow path 1213 have openings that connect to the first cooling water supply pipe 125 and the first cooling water discharge pipe 126 located on one side of the main surface of the manifold 121. Furthermore, the first cooling flow path 1213 is configured to exchange heat with the base plate 111 fixed to the manifold 121.

[0058] The first manifold 1214 is formed in the shape of a rectangular plate. The first manifold 1214 has, for example, grooves and openings that form part of a pair of supply paths 1211, a pair of discharge paths 1212, and a first cooling flow path 1213. The grooves and openings that form part of the supply paths 1211 and the discharge paths 1212 are appropriately configured and sized according to the shape of the supply paths 1211 and the discharge paths 1212, and the shape of other fluid flow paths.

[0059] The second manifold 1215 is formed in the shape of a rectangular plate. The second manifold 1215, for example, has grooves and openings that form part of a pair of supply paths 1211, a pair of discharge paths 1212, and a first cooling flow path 1213. The grooves and openings that form part of the supply paths 1211 and the discharge paths 1212 are appropriately configured and sized according to the shape of the supply paths 1211 and the discharge paths 1212, and the shape of other fluid flow paths.

[0060] The first manifold 1214 and the second manifold 1215 are connected together to form a supply path 1211, an exhaust path 1212 and a first cooling flow path 1213.

[0061] A top plate 122 is disposed on the surface of the manifold 121 opposite to the surface on which the base plate 111 is disposed. The top plate 122 has an opening that connects the ink supply pipe 123, the ink discharge pipe 124, the first cooling water supply pipe 125, and the first cooling water discharge pipe 126 to the supply path 1211, the discharge path 1212, and the first cooling flow path 1213 of the manifold 121. For example, the top plate 122 is formed of two plate-shaped components. One plate-shaped component is provided with one of the ink supply pipe 123 and the ink discharge pipe 124, and one of the first cooling water supply pipe 125 and the first cooling water discharge pipe 126. The other plate-shaped component is provided with the other of the ink supply pipe 123 and the ink discharge pipe 124, and the other of the first cooling water supply pipe 125 and the first cooling water discharge pipe 126.

[0062] Ink supply pipe 123 is connected to supply path 1211. Ink discharge pipe 124 is connected to discharge path 1212. In this embodiment, the liquid nozzle 1 has a pair of head bodies 11, so a pair of ink supply pipes 123 and ink discharge pipes 124 are respectively provided. The first cooling water supply pipe 125 and the first cooling water discharge pipe 126 are connected to the primary side and the secondary side of the first cooling flow path 1213.

[0063] In this embodiment, a pair of ink supply pipes 123 and a first cooling water discharge pipe 126 are arranged at one end of the manifold 121 along its length, and a pair of ink discharge pipes 124 and a first cooling water supply pipe 125 are arranged at the other end of the manifold 121 along its length.

[0064] like Figures 6 to 8 As shown, the damper 127 is formed as a thin film or sheet capable of elastic deformation. For example... Figure 7 As shown, damper 127 covers the canopy portion 12111 of the supply path 1211 of the second manifold 1215. Damper 127 elastically deforms according to pressure variations in the supply path 1211. One side of damper 127 faces the supply path 1211.

[0065] As a specific example, the damper 127 is formed of a polyimide film. The damper 127 is formed as a rectangle that is longer in the same direction as the length direction (first direction X) of the opening of the canopy portion 12111 of the supply path 1211 which is longer in one direction (first direction X).

[0066] like Figure 6 As shown, the bypass flow path 128 connects the canopy portion 12111 of the supply path 1211 to the common liquid chamber 116 or the secondary side of the common liquid chamber 116. Furthermore, the common liquid chamber 116 or the secondary side of the common liquid chamber 116 connected to the bypass flow path 128 refers, for example, to the second common liquid chamber 1162 or the third common liquid chamber 1163 of the common liquid chamber 116, the discharge path 1212, or the ink discharge pipe 124. The fluid resistance of the bypass flow path 128 is greater than the fluid resistance of the supply path 1211 and the fluid resistance of the common liquid chamber 116.

[0067] The bypass flow path 128 bypasses the supply path 1211 and the common liquid chamber 116, thereby expelling air bubbles from the supply path 1211 during maintenance and ink filling. The cross-sectional shape of the bypass flow path 128 is formed into a rectangular or circular shape. The shape of the bypass flow path 128 may be, for example, a straight line or a partially bent vent shape.

[0068] like Figure 2 , Figure 4 and Figure 10As shown, the cooling flow path unit 13 includes, for example, a cooling flow path section 131, a cooling water top plate 132, a second cooling water supply pipe 133, and a second cooling water discharge pipe 134. The cooling flow path unit 13 is connected to the cooling device 2116 of the liquid ejection device 2. The cooling flow path unit 13 is a cooling structure that cools the driver IC 142, which is a heat source.

[0069] The cooling flow path 131 is connected to the second cooling water supply pipe 133 and the second cooling water discharge pipe 134 via the cooling water top plate 132. The cooling flow path 131 includes a branch flow path 1311 connected to the second cooling water supply pipe 133, a second cooling flow path 1312 for cooling the multiple driver ICs described later as heat-generating parts, and a confluence flow path 1313.

[0070] Branch flow path 1311 branches the cooling water supplied by the second cooling water supply pipe 133 into two directions. The flow path on one side of the branch flow path 1311 is connected to the first cooling flow path 1213, and the flow path on the other side of the branch flow path 1311 is connected to the second cooling flow path 1312.

[0071] The second cooling flow path 1312 is connected to the flow path that is branched off from the branch flow path 1311. The second cooling flow path 1312 is fewer in number than the multiple driver ICs on the primary side and is branched into multiple flow paths, forming a single flow path on the secondary side. The second cooling flow path 1312 cools the driver IC 142.

[0072] As a specific example, in this embodiment, the nozzle array 1142 is provided in four rows, the actuator 113 is provided in four rows, and the driver IC 142 is provided in four rows. Therefore, as Figure 2 , Figure 4 and Figure 10 As shown, the cooling flow path 131 has three flow path sections 13121 that constitute the second cooling flow path 1312. These three flow path sections 13121 are longer in one direction (first direction X) and are arranged in a direction orthogonal to the length direction of the flow path section 13121 (second direction Y).

[0073] The three flow path sections 13121 consist of a pair (two) single-row cooling flow path sections 13122 and a multi-row cooling flow path section 13123. The pair of single-row cooling flow path sections 13122 are disposed at both ends (outer sides) of the arrangement direction (second direction Y) of the three flow path sections 13121. The pair of single-row cooling flow path sections 13122 respectively cool a driver IC 142 that drives the actuator 113 to eject ink from the single row of nozzles 1142. The outer surface of the single-row cooling flow path section 13122 abuts against the corresponding driver IC 142.

[0074] The multi-row cooling flow path 13123 is disposed on the inner side in the arrangement direction (second direction Y) of the three flow path sections 13121. That is, the multi-row cooling flow path 13123 is disposed between a pair of single-row cooling flow path sections 13122 in the arrangement direction (second direction Y) of the three flow path sections 13121. The multi-row cooling flow path 13123 cools the two driver ICs 142 that drive the two actuators 113 respectively, which cause ink to be ejected from two adjacent rows of nozzles 1142 of the two sets of head bodies 11. The different outer surfaces of the multi-row cooling flow path 13123 abut against the corresponding two driver ICs 142.

[0075] For example, such as Figure 4 and Figure 10 As shown, the width WA of the flow path 131221 formed by the single-row cooling flow path section 13122 is narrower than the width WB of the flow path 131231 formed by the multi-row cooling flow path section 13123. The widths WA and WB of the flow path 131221 refer to... Figure 10 The width in the second direction, Y direction. Furthermore, the cross-sectional area of ​​the flow path 131221 formed by the single-row cooling flow path 13122 is smaller than the cross-sectional area of ​​the flow path of the multi-row cooling flow path 13123. This is because the single-row cooling flow path 13122 cools one driver IC 142, while the multi-row cooling flow path 13123 cools two driver ICs 142. Therefore, the width WB of the flow path 131231 of the multi-row cooling flow path 13123 is greater than the width WA of the flow path 131221 of the single-row cooling flow path 13122, so that the cooling capacity of 13123 is higher than that of the single-row cooling flow path 13122.

[0076] The merging flow path 1313 merges the first cooling flow path 1213 and the second cooling flow path 1312, and is connected to the second cooling water discharge pipe 134.

[0077] Such a cooling flow path 131 includes, for example, a cooling manifold 1314, a cover plate 1315 covering the cooling manifold 1314, and a pair of cooling blocks 1316 disposed on the cover plate 1315.

[0078] The second cooling flow path 1312 is a flow path formed by holes and grooves formed in the cooling manifold 1314, the cover plate 1315 and a pair of cooling blocks 1316.

[0079] The cooling manifold 1314 is formed in the shape of a plate or a block. The cooling manifold 1314 is, for example, fixed to the manifold 121. Two openings 13141 are formed in the cooling manifold 1314 for arranging a portion of the wiring film 141 of the driver IC 142 (described later), which houses the circuit board 14, and the printed wiring board 143. The openings 13141 are along the length direction (first direction X) of the flow path 13121.

[0080] In the cooling manifold 1314, three portions adjacent to the two openings 13141 respectively constitute part of three flow path sections 13121. For example, a groove 13142 is formed in the cooling manifold 13144. The groove 13142 has a shape in which three flow paths—one branching into two single-row cooling flow path sections 13122 forming a flow path 131231 and one multi-row cooling flow path section 131231 forming a flow path 131231—converge.

[0081] The cover plate 1315 is formed in a plate shape. Two openings 13151 are formed in the cover plate 1315 along the length direction (first direction X) of the flow path 13121 for arranging a portion of the wiring film 141 and the printed wiring substrate 143. The cover plate 1315 covers the groove 13142 formed in the cooling manifold 1314 and is liquid-tightly fixed to the cooling manifold 1314. The cover plate 1315 and the cooling manifold 1314 together constitute the second cooling flow path 1312. When the cover plate 1315 is integrally assembled to the cooling manifold 1314, the two openings 13151 of the cover plate 1315 and the openings 13141 of the cooling manifold 1314 are opposite each other. The cover plate 1315, for example, has multiple openings that connect the second cooling flow path 1312 to the branch flow path 1311 and the confluence flow path 1313.

[0082] The cooling block 1316 has grooves and openings that internally form branch flow paths 1311 or confluence flow paths 1313. That is, one of the pair of cooling blocks 1316 forms a branch flow path 1311, and the other forms a confluence flow path 1313. The pair of cooling blocks 1316 are fixed to a cover plate 1315. The pair of cooling blocks 1316 are positioned opposite each other in the first direction X at a distance from the wiring film 141 on which the circuit board 14 can be disposed, to the printed wiring board 143 described later. The cooling block 1316, for example, has a pipe portion 13161 that connects the branch flow path 1311 or the confluence flow path 1313 to the first cooling water supply pipe 125 or the first cooling water discharge pipe 126. Furthermore, the cooling block 1316, for example, the printed wiring board 143 described later, in which four circuit boards 14 are disposed, has a plurality of ribs 13162 and a plurality of grooves 13163 for support.

[0083] A cooling water top plate 132 is disposed on the surface of a pair of cooling blocks 1316 opposite to the surface on which the cover plate 1315 is disposed. For example, a pair of cooling water top plates 132 are provided. Each cooling water top plate 132 has an opening for connecting a second cooling water supply pipe 133 or a second cooling water discharge pipe 134 to a branch flow path 1311 or a confluence flow path 1313 of the cooling block 1316. A printed wiring substrate 143 is disposed, for example, on the cooling water top plate 132, and a plurality of grooves for support are formed therein.

[0084] like Figures 1 to 4 As shown, one end of the circuit board 14 is connected to the wiring pattern of the actuator 113 via the wiring pattern of the base plate 111. The circuit board 14 includes, for example, a wiring film 141, a driver IC 142 mounted on the wiring film, and a printed wiring board 143 mounted on the wiring film.

[0085] The circuit board 14 applies a driving voltage to the actuator 113 via the wiring pattern of the base plate 111 through the driver IC 142, thereby driving the actuator 113 to increase or decrease the volume of the pressure chamber 1131, causing droplets to be ejected from the nozzle 1141.

[0086] The wiring film 141 is formed in a thin film shape and is a thin film substrate on which wiring patterns are formed. For example, multiple wiring films 141 are provided. The wiring film 141 is, for example, a COF (Chip on Film) on which a driver IC 142 is mounted. For example, the number of wiring films 141 is the same as the number of actuators 113 provided in a head body 11, that is, the same number as the number of nozzle rows 1142. Furthermore, one wiring film 141 is connected to one actuator 113. Alternatively, there may be a structure in which multiple wiring films 141 are connected to one actuator 113. In this case, the wiring film rows and driver IC rows composed of multiple wiring films 141 and driver ICs mounted on the wiring films 142 are formed in the same number of rows as the actuators 113.

[0087] In this embodiment, the head body 11 is structured with two rows of nozzles 1142 (two actuators 113), so two wiring films 141 are provided in one head body 11. Furthermore, the liquid ejection head 1 with two sets of head bodies 11 has four wiring films 141. The four wiring films 141 are arranged, for example, extending along a third direction Z, and are arranged in this manner along a second direction Y.

[0088] The driver IC 142 is electrically connected to the wiring pattern formed in the pressure chamber 1131 via the wiring film 141. The driver IC 142 is a heat-generating component. The driver IC 142 is mounted on the outer surface side of the wiring film 141. Here, the outer surface side of the wiring film 141 refers to the side opposite to the side (inner surface) of the two wiring films 141 of one head body 11 when arranged in a configuration extending in the third direction Z. In other words, the outer side of the wiring film 141 refers to the side outside the second direction Y of the head body 11 when the center side of the second direction Y of the head body 11 is taken as the inner side. Therefore, the outer surfaces of the two inner wiring films 141 of the four wiring films 141 of the two sets of head bodies 11 are opposite each other.

[0089] In driver IC 142, the surface opposite to the mounting surface of the wiring film 141 abuts against the outer surface of the flow path 13121. For example, the surface of driver IC 142 directly contacts the outer surface of the flow path 13121. One driver IC 142 is provided for one wiring film 141. Alternatively, multiple driver ICs 142 can be provided to drive one actuator 113, and these multiple driver ICs 142 are provided on one wiring film 141, forming a driver IC row. In this case, multiple driver ICs 142 in the same driver IC row abut against the corresponding flow path 13121.

[0090] A printed wiring board 143 is, for example, a PWA (Printing Wiring Assembly) on which various electronic components and connectors are mounted.

[0091] The cover plate 15 covers or stores a part of the head body 11, a part of the manifold unit 12, and the circuit board 14.

[0092] The liquid ejector head 1 thus configured has a first cooling flow path 1213 that cools the head body 11, which serves as the liquid ejection section, via a manifold unit 12 and a cooling flow path unit 13, and a second cooling flow path 1312 that cools the driver IC 142, which serves as the heat source. Cooling water supplied by the second cooling water supply pipe 133 passes through the first cooling flow path 1213 and the second cooling flow path 1312, and is discharged from the second cooling water discharge pipe 134. Furthermore, the cooling water flowing in the first cooling flow path 1213 cools the head body 11, and the cooling water flowing in the second cooling flow path 1312 cools the driver IC 142.

[0093] Furthermore, the second cooling flow path 1312 has a number of (three-row) flow path sections 13121 fewer than the number of (four-row) nozzle rows 1142 and the number of (four-row) actuators 113. The flow path sections 13121 located at both ends (outer sides) of the arrangement direction (second direction Y) constitute single-row cooling flow path sections 13122 that cool the driver ICs 142 corresponding to each single-row nozzle row 1142 (one actuator 113). Furthermore, the flow path section 13121 between a pair of single-row cooling flow path sections 13122 constitutes a multi-row cooling flow path section 13123 that cools, for example, two driver ICs 142 corresponding to two rows of nozzle rows 1142 (two actuators 113). Therefore, the number of flow path sections 13121 in the second cooling flow path 1312 can be less than the number of nozzle rows 1142 (actuators 113). Thus, it is possible to prevent the liquid ejector head 1 from becoming too large.

[0094] Furthermore, the width WB and cross-sectional area of ​​the flow path 131231 formed in the multi-row cooling flow path section 13123 are greater than the width WA and cross-sectional area of ​​the flow path 131221 formed in the single-row cooling flow path section 13122. Therefore, the multi-row cooling flow path section 13123 provides superior cooling performance even when cooling two driver ICs 142.

[0095] Furthermore, the second cooling flow path 1312 can also be a simple structure in which the driver IC abuts against the outer surface of the multiple flow path sections 13121 through which cooling water passes. Additionally, the second cooling flow path 1312 can also be a simple structure in which the cooling manifold 1314, the cover plate 1315, and a pair of cooling blocks 1316 are assembled into one unit.

[0096] The liquid ejector head 1 can cool the driver IC 142, which is a heat source, through the second cooling flow path 1312, thus preventing damage to surrounding structural components due to heat. Furthermore, the liquid ejector head 1 can cool the head body 11 through the first cooling flow path 1213, thus preventing a decrease in printing accuracy due to heat.

[0097] Figure 11 and Figure 12 The cooling effect is shown in the analysis simulation based on the cooling of the driver IC142 in the liquid nozzle 1 of the embodiment and the liquid nozzle of the comparative example, respectively. Additionally, Figure 11 This indicates the cooled temperature of the outer driver IC 142, which is cooled by the single-row cooling flow path section 13122. Furthermore, Figure 12 This indicates the temperature of the driver IC 142 after cooling, which is cooled by the multi-row cooling flow path section 13123.

[0098] Here, the water-cooled circulation structure used in the liquid nozzle as a comparative example is configured such that cooling flow paths are provided on the back side (inner side) of two rows of driver ICs in each of the four outward-facing rows, and a heat-conducting plate is provided on the surface of the driver IC for the metal component that forms the cooling flow path. The cooling flow path has a structure with two flow path sections. The cooling water supply side is a single line, which is configured to branch in two directions to form two flow path sections and merge at the discharge side.

[0099] like Figure 11 and Figure 12 As shown, compared to the liquid nozzle of the comparative example, the liquid nozzle 1 of the embodiment can reduce the temperature of the driver IC142 to approximately -20°C by both the outer and inner driver IC142. Therefore, it is determined that the liquid nozzle 1 of the embodiment can achieve a higher cooling effect.

[0100] Below, refer to Figure 13 The liquid ejection device 2 having a liquid ejection head 1 will be described. The liquid ejection device 2 includes a housing 2111, a medium supply unit 2112, an image forming unit 2113, a medium discharge unit 2114, a conveying device 2115 as a support device, a cooling device 2116, a maintenance device 2117, and a control unit 2118.

[0101] The liquid ejection device 2 is an inkjet printer that ejects liquid such as ink while conveying a recording medium, such as paper P, which is the object to be ejected, along a predetermined transport path 2001 from the media supply unit 2112 through the image forming unit 2113 to the media discharge unit 2114, thereby performing image forming processing on the paper P.

[0102] The media supply unit 2112 includes multiple paper feed trays 21121. The image forming unit 2113 includes a support unit 2120 for supporting paper and multiple head units 2130 disposed opposite each other above the support unit 2120. The media discharge unit 2114 includes a paper discharge tray 21141.

[0103] The support portion 2120 includes a conveyor belt 21201 arranged in a ring shape in a predetermined area where image formation is performed, a support plate 21202 that supports the conveyor belt 21201 from the back side, and a plurality of belt rollers 21203 arranged on the back side of the conveyor belt 21201.

[0104] The head unit 2130 includes multiple liquid ejector heads 1 that serve as inkjet heads, multiple supply tanks 2132 that serve as liquid tanks mounted on each liquid ejector head 1, a pump 2134 that supplies ink, and a connecting flow path 2135 that connects the liquid ejector head 1 and the supply tank 2132.

[0105] In this embodiment, there are four liquid nozzles 1 of different colors: cyan, magenta, yellow, and black, and four supply boxes 2132 for each color of ink. The supply boxes 2132 are connected to the liquid nozzles 1 via a flow path 2135.

[0106] Pump 2134 is, for example, a liquid delivery pump composed of a piezoelectric pump. Pump 2134 is connected to control unit 2118, and is driven and controlled by control unit 2118.

[0107] The connecting flow path 2135 includes a supply flow path connected to the ink supply pipe 123 of the liquid nozzle 1. Furthermore, the connecting flow path 2135 includes a recovery flow path connected to the ink discharge pipe 124 of the liquid nozzle 1. For example, if the liquid nozzle 1 is non-circulating, the recovery circuit is connected to the maintenance device 2117. Alternatively, if the liquid nozzle 1 is circulating, the recovery flow path is connected to the supply tank 2132.

[0108] The conveying device 2115 conveys paper P along a conveying path 2001 from the paper feed tray 21121 of the media supply unit 2112 through the image forming unit 2113 to the paper discharge tray 21141 of the media discharge unit 2114. The conveying device 2115 includes multiple guide plates 21211 to 21218 arranged along the conveying path 2001 and multiple conveying rollers 21221 to 21228. The conveying device 2115 supports the paper P, which can move relative to the liquid ejector head 1.

[0109] The cooling device 2116 includes a cooling water tank 21161, a cooling circuit 21162 for supplying cooling water via piping and hoses, a pump for supplying cooling water, and a cooler for adjusting the temperature of the cooling water. The cooling device 2116 supplies cooling water from the cooling water tank 21161, which has been adjusted to a predetermined temperature by the cooler, to the second cooling water supply pipe 133 via the pump and the cooling circuit 21162. Furthermore, the cooling device 2116 recovers water discharged from the second cooling water discharge pipe 134 through the first cooling flow path 1213 and the second cooling flow path 1312 back into the cooling water tank 21161 via the cooling circuit 21162. The cooler is, for example, a condenser.

[0110] Maintenance device 2117, for example, attracts and recovers ink remaining on the outer surface of nozzle plate 114 during maintenance. Furthermore, in the case where the liquid nozzle 1 is non-circulating, maintenance device 2117 recovers ink from the nozzle 1141 within the head body 11 during maintenance. Such maintenance device 2117 includes a tray, box, or the like for storing the recovered ink.

[0111] The control unit 2118 includes a CPU 21181, which serves as a processor, and memory such as ROM (Read-Only Memory) for storing various programs, RAM (Random Access Memory) for temporarily storing various variable data and image data, and an interface unit for inputting data from the outside and outputting data to the outside.

[0112] In the liquid ejector head 1 and liquid ejection device 2 described above, the number of flow path sections 13121 that cool the driver IC 142, which serves as a heat-generating unit, is less than the number of nozzle rows 1142 and the number of actuators 113. Furthermore, the driver IC 142 abuts against the outer surface of the flow path section 13121. Therefore, the liquid ejector head 1 and liquid ejection device 2 can achieve miniaturization and simplification while ensuring a high cooling function of the second cooling flow path 1312 of the cooling flow path unit 13, which is a cooling structure.

[0113] Furthermore, the embodiments of the present invention are not limited to the structures described above. For example, in the examples described above, a non-circular example was given with respect to the head body 11, but a circular head body is also possible.

[0114] Furthermore, in the above example, the liquid nozzle head 1 is described as having a four-row nozzle array, but it is not limited to this. For example, the liquid nozzle head 1 may also have a structure with three sets of head bodies 11 and a six-row nozzle array. When the liquid nozzle head 1 is configured in this way, it is sufficient to configure it as follows: in the nozzle array arrangement direction (second direction Y), a pair of single-row cooling flow path sections 13122 are provided at both ends, and two (pair) multi-row cooling flow path sections 13123 are provided between the pair of single-row cooling flow path sections 13122.

[0115] Furthermore, the example described above illustrates an instance where the surface of the driver IC142 directly contacts the outer surface of the flow path portion 13121, but this is not a limitation. For example, the driver IC142 may also have a structure in which it contacts the outer surface of the flow path portion 13121 through a sheet-like, strip-like, gel-like, or liquid component formed of a material with high thermal conductivity.

[0116] Furthermore, while the above embodiments illustrate an example of a recording device for ejecting ink as a liquid using the liquid ejector head 1 and liquid ejection device 2, the invention is not limited to this. That is, the liquid ejector head 1 and liquid ejection device 2 can also be applied to, for example, 3D printers, industrial manufacturing machinery, and medical applications.

[0117] According to at least one embodiment described above, multiple flow path sections that abut against the driver IC are provided in a manner that is fewer than the number of nozzle rows, thereby enabling miniaturization and simplification while ensuring high cooling performance of the cooling structure.

[0118] While several embodiments of the invention have been described, these embodiments are merely illustrative and not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and likewise within the scope of the invention as set forth in the claims and its equivalents.

Claims

1. A liquid ejector head, comprising: The liquid ejection section has multiple rows of nozzles; Multiple heating elements, corresponding to the multiple rows of nozzles; and The cooling flow path section has a smaller number of flow paths than the number of nozzle rows, each having a flow path for cooling water and whose outer surface abuts against the plurality of heat-generating parts. The plurality of nozzle rows extend along a first direction, and are arranged in a plurality of configurations along a second direction orthogonal to the first direction. The heating element is a driver IC connected to the liquid ejection part, and multiple such elements are arranged along the second direction. The flow path portions are arranged in a plurality of configurations along the second direction, respectively, and are disposed opposite to each other on one or the other side of the driver IC in the second direction, and extend along the first direction. The plurality of flow path sections include a pair of single-row cooling flow path sections arranged at both ends in the arrangement direction and a plurality of cooling flow path sections arranged between the pair of single-row cooling flow path sections. The multi-row cooling flow path section has the heating element disposed opposite to each other on both sides in the second direction, and the width and cross-sectional area of ​​the flow path in the second direction are greater than the width and cross-sectional area of ​​the flow path in the second direction of the single-row cooling flow path section.

2. The liquid ejector head according to claim 1, wherein, The cooling flow path section has a branch flow path that branches the flow path for cooling the liquid ejection section.

3. The liquid ejector head according to claim 1, wherein, The nozzle array consists of four columns. The cooling flow path has three flow paths, and there are two openings between the three adjacent flow paths in the second direction for the arrangement of the plurality of heat-generating parts.

4. The liquid ejector head according to claim 2, wherein, The nozzle array consists of four columns. The cooling flow path has three flow paths, and there are two openings between the three adjacent flow paths in the second direction for the arrangement of the plurality of heat-generating parts.

5. The liquid ejector head according to claim 1, wherein, The liquid ejector head is an inkjet head installed in the liquid ejection device.

6. The liquid ejector head according to claim 1, wherein, The liquid nozzle is supplied with ink as a liquid.

7. The liquid ejector head according to claim 1, wherein, The liquid ejector head is a non-circulating type.

8. The liquid ejector head according to claim 1, wherein, The liquid ejector head has two head bodies.

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