JP2023103780A - Liquid discharge head - Google Patents

Abstract

To provide a liquid discharge head which enables downsizing and simplification of a cooling structure of heating parts.SOLUTION: A liquid discharge head according to an embodiment includes: a liquid discharge part; multiple heating parts; and a cooling passage part. The liquid discharge part has multiple nozzle arrays. The heating parts respectively correspond to the multiple nozzle arrays. The cooling passage part has a fewer number of passage parts, in which a coolant flows and which respectively contact with the heating parts, than a number of the nozzle arrays.SELECTED DRAWING: Figure 5

Description

TECHNICAL FIELD Embodiments of the present invention relate to liquid ejection heads.

Depending on the component configuration of the liquid ejection head, the driver IC may have to face outward. When such a liquid ejection head has a structure of a plurality of nozzle rows, a water-cooling circulation path is provided on the rear surface of the driver IC facing each other, and a heat transfer plate is attached from the outside to radiate heat.

Recently, however, there is a demand for high-speed printing with high productivity, and the amount of heat generated by the driver IC tends to increase when the driver IC is driven. For this reason, there is a concern that it is difficult to obtain an appropriate cooling effect with the conventional heat dissipation structure. Improving the cooling effect increases the volume of the cooling structure, which may increase the size of the liquid ejection head, complicate the cooling structure, and increase the cost. Since these burden the printer device, it is desired to simplify them as much as possible.

Japanese Patent Application Laid-Open No. 2021-20451

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid ejection head capable of downsizing and simplifying the cooling structure of the heat generating portion.

A liquid ejection head according to an embodiment includes a liquid ejection portion, a plurality of heat generating portions, and a cooling channel portion. The liquid ejection section has a plurality of nozzle rows. A heat generating portion corresponds to the plurality of nozzle rows. The cooling channel section has a plurality of channel sections through which cooling water flows and which are in contact with the plurality of heat generating sections, respectively, the number of which is smaller than the number of the nozzle rows.

1 is a perspective view showing the configuration of a liquid ejection head according to an embodiment; FIG. 1 is an exploded perspective view showing the configuration of a liquid ejection head according to an embodiment; FIG. 1 is a side view showing the configuration of a liquid ejection head according to an embodiment; FIG. 1 is a cross-sectional view showing the configuration of a liquid ejection head according to an embodiment; FIG. FIG. 2 is a view showing the configuration of the liquid ejection head according to the embodiment from the nozzle plate side; FIG. 2 is a perspective view showing, in partial cross section, the configuration of a head body and a manifold unit of the liquid ejection head according to the embodiment; FIG. 2 is a cross-sectional view showing the configuration of a head body and a manifold unit according to the embodiment; FIG. 2 is a cross-sectional view showing the configuration of a head body and a manifold unit according to the embodiment; FIG. 2 is a diagram showing a partly omitted configuration of a head body according to the embodiment; FIG. 2 is an exploded perspective view showing the configuration of the cooling channel unit according to the embodiment; FIG. 5 is an explanatory diagram showing the results of analytical simulations of the liquid ejection head according to the embodiment and the liquid ejection head according to the comparative example; FIG. 5 is an explanatory diagram showing the results of analytical simulations of the liquid ejection head according to the embodiment and the liquid ejection head according to the comparative example; 1 is an explanatory diagram showing the configuration of a liquid ejection device according to an embodiment; FIG.

A liquid ejection head 1 according to an embodiment and a liquid ejection apparatus 2 using the liquid ejection head 1 will be described below with reference to FIGS. 1 to 13. FIG. FIG. 1 is a perspective view showing the configuration of the liquid ejection head 1 according to the embodiment with the cover 15 omitted. 2 is an exploded perspective view showing the configuration of the liquid ejection head 1 with the cover 15 omitted, FIG. 3 is a side view showing the configuration of the liquid ejection head 1, and FIG. 2 is a cross-sectional view showing the configuration of , omitting a cover 15. FIG.

FIG. 5 is a diagram showing the configuration of the liquid ejection head 1 from the nozzle plate 114 side. 6 is a perspective view showing the configuration of the head main body 11 and the manifold unit 12 of the liquid ejection head 1 in a partial cross section, FIG. 7 is a cross-sectional view showing the configuration of the head main body 11 and the manifold unit 12, and FIG. 3 is an enlarged cross-sectional view showing the configuration of the main body 11 and the manifold unit 12. FIG.

FIG. 9 is a diagram showing the structure of the head body 11 with a part thereof omitted. FIG. 10 is an exploded perspective view showing the configuration of the cooling channel unit 13. As shown in FIG. 11 and 12 are explanatory diagrams showing the temperature of the driver IC 142 after cooling as results of analytical simulations of the liquid ejection head 1 according to the embodiment and the liquid ejection head according to the comparative example. FIG. 13 is an explanatory diagram showing the configuration of the liquid ejection device 2 according to the embodiment. In FIG. 2, an example of the flow of cooling water is indicated by dashed arrows.

X-axis, Y-axis, and Z-axis orthogonal to each other are shown in FIGS. 1 to 10 . In the following description, the direction along the X-axis is defined as a first direction X, the direction along the Y-axis is defined as a second direction Y, and the direction along the Z-axis is defined as a third direction Z. Also, in each drawing, for the sake of explanation, the configuration is shown enlarged, reduced, or omitted as appropriate.

The liquid ejection head 1 is, for example, an inkjet head provided in a liquid ejection apparatus 2 such as the inkjet recording apparatus shown in FIG. The liquid ejection head 1 is provided in a head unit 2130 including a supply tank 2132 as a liquid container provided in the liquid ejection device 2 .

The liquid ejection head 1 is supplied with ink as liquid stored in the supply tank 2132 . The liquid ejection head 1 may be a non-circulating head that does not circulate ink, or a circulating head that circulates ink. In this embodiment, the liquid ejection head 1 will be described using an example of a non-circulating head. The liquid ejection head 1 is also connected to a cooling device 2116 provided in the liquid ejection device 2, and is supplied with a cooling liquid (cooling water) for controlling the temperature of the heat generating portion and the ink. The liquid ejection head 1 constitutes a water cooling circulation structure together with the cooling device 2116 .

As shown in FIGS. 1 to 4, the liquid ejection head 1 includes a head body 11, a manifold unit 12, a cooling channel unit 13, a circuit board 14, and a cover 15. For example, the liquid ejection head 1 is a side shooter type four-row integral structure head having two sets of head bodies 11 each having a pair of actuators 113 .

The head body 11 ejects liquid. As shown in FIGS. 3 to 9, the head body 11 includes a base plate 111, a frame 112, an actuator 113, a nozzle plate 114, and a mask plate 115. As shown in FIGS. The head body 11 also has a common liquid chamber 116 . In the example of this embodiment, an example in which one head body 11 has two actuators 113 will be described.

As shown in FIGS. 7 to 9, the base plate 111 is made of, for example, a ceramic material and has a rectangular shape. The base plate 111 is formed, for example, in a rectangular shape elongated in one direction (first direction X). As shown in FIG. 9, the base plate 111 has a single supply port 1111 and a single or multiple 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 penetrating between the main surfaces of the base plate 111 .

A single supply port 1111 is provided, for example, at a position of the common liquid chamber 116 facing a first common liquid chamber 1161 described later. The supply port 1111 is, for example, an elongated hole elongated in one direction along the longitudinal direction (first direction X) of the first common liquid chamber 1161 . The supply port 1111 is, for example, a rectangular shape elongated in one direction, or an elongated hole with semicircular ends and a uniform width. The width of the supply port 1111 in the longitudinal direction is, for example, greater than or equal to the width (length) of the actuator 113 in the longitudinal direction, or is smaller than the length of the actuator 113, and the normal ink discharge formed in the actuator 113. The length is set to be approximately the same as the range (the entire nozzle range) in which the pressure chambers 1131 to be driven are provided.

Two discharge ports 1112 are provided, for example, at positions facing at least one third common liquid chamber 1163 of two third common liquid chambers 1163 (to be described later) of the common liquid chamber 116 . For example, as shown in FIG. 9, the outlet 1112 is provided in the base plate 111 so as to be arranged in one of the third common liquid chambers 1163 adjacent to one end in the longitudinal direction of the pair of actuators 113 . . Note that, for example, two discharge ports 1112 may be provided in each of the two third common liquid chambers 1163 of the common liquid chamber 116 .

As shown in FIG. 9, the frame 112 is fixed to one main surface of the base plate 111 with an adhesive or the like. The frame 112 surrounds the supply port 1111 , the plurality of discharge ports 1112 provided on the base plate 111 , and the actuator 113 .

For example, the frame 112 is formed in a rectangular frame shape that is long in one direction (first direction X), thereby forming an opening that is long in one direction along the longitudinal direction 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 .

The actuator 113 is formed in a plate shape elongated in one direction (first direction X). A pair of actuators 113 are adhered to the mounting surface of the base plate 111 . As shown in FIG. 9, the pair of actuators 113 are arranged in two rows on the base plate 111 with the supply port 1111 interposed therebetween in the lateral direction (second direction Y) orthogonal to the longitudinal direction of the actuators 113 . The actuator 113 is arranged in the opening of the frame 112 and adhered to the main surface of the base plate 111 . As a specific example, the actuator 113 is formed by adhering two rectangular plates of piezoelectric material that are long in one direction so that their polarization directions are opposite to each other. Here, the piezoelectric material is, for example, PZT (lead zirconate titanate). The actuator 113 is adhered to the mounting surface of the base plate 111 with, for example, a thermosetting epoxy adhesive.

The actuator 113 has, for example, a plurality of pressure chambers 1131 arranged at equal intervals in the longitudinal direction (first direction X). A plurality of grooves are formed in the longitudinal direction of the actuator 113 on the principal surface side opposite to the base plate 111 side of the actuator 113 , and pressure chambers 1131 are formed by these grooves. In other words, the actuator 113 has a plurality of longitudinally equally spaced walls 1133 forming grooves therebetween. A plurality of walls 1133 form a plurality of pressure chambers 1131 between adjacent walls. That is, the plurality of walls 1133 are partition walls that separate the plurality of pressure chambers 1131 . Also, the wall 1133 is a piezoelectric body as a drive element that changes the volume of the pressure chamber 1131 by applying a drive voltage.

A surface of the actuator 113 opposite to the base plate 111 is adhered to the nozzle plate 114 . Also, the actuator 113 is formed with wiring patterns for driving the plurality of pressure chambers 1131 .

The pressure chamber 1131 is a pressure chamber for ejecting ink from the nozzle 1141 when the liquid ejection head 1 performs printing or the like. In this embodiment, an example in which the actuator 113 has a plurality of pressure chambers 1131 has been described. good.

As shown in FIGS. 4, 5, 7 and 8, 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 with an adhesive or the like. The nozzle plate 114 has a plurality of nozzles 1141 formed at positions facing the plurality of pressure chambers 1131 . In this embodiment, the nozzle plate 114 has two nozzle rows 1142 in which a plurality of nozzles 1141 are arranged in one direction (first direction X). In the present embodiment, the liquid ejection head 1 has two sets of head main bodies 11, so the liquid ejection head 1 has four nozzle rows 1142 as shown in FIG.

A plurality of nozzles 1141 facing the plurality of pressure chambers 1131 are holes through which ink is ejected during operations such as printing by the liquid ejection head 1 .

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

As shown in FIG. 5, the mask plate 115 has a pair of windows 1151 that expose a nozzle row 1142 composed of a plurality of nozzles 1141 for ejecting liquid from the pair of nozzle plates 114 .

As shown in FIG. 9, the common liquid chamber 116 communicates with the supply port 1111 . A common liquid chamber 116 is provided around the pair of actuators 113 . Specifically, the common liquid chamber 116 communicates with the primary side and secondary side of the plurality of pressure chambers 1131 of each actuator 113 . Also, the common liquid chamber 116 communicates with the outlet 1112 .

As a specific example, as shown in FIG. 9, the common liquid chamber 116 includes a first common liquid chamber 1161 long in one direction (first direction X) and two second common liquid chambers long in one direction (first direction X). It has a liquid chamber 1162 and a third common liquid chamber 1163 connecting both ends of the first common liquid chamber 1161 and both ends of the two second common liquid chambers 1162 . The common liquid chamber 116 communicates the supply port 1111 with one opening of the plurality of pressure chambers 1131 of the actuator 113 through the first common liquid chamber 1161 , and the third common liquid chamber 1163 through the second common liquid chamber 1162 . and the other openings of the plurality of pressure chambers 1131 .

A first common liquid chamber 1161 is formed between the pair of actuators 113 . The first common liquid chamber 1161 constitutes an ink flow path from the supply port 1111 to one opening of the plurality of pressure chambers 1131 of each actuator 113 . In addition, the first common liquid chamber 1161 allows ink to flow from the supply port 1111 to two third common liquid chambers 1163 at both ends in the longitudinal direction (first direction X) of the first common liquid chamber 1161 (actuator 113). Construct the flow path.

A second common liquid chamber 1162 is formed between each actuator 113 and the frame 112 . The second common liquid chamber 1162 forms an ink flow path from the third common liquid chamber 1163 to the other opening of the plurality of pressure chambers 1131 .

The third common liquid chamber 1163 is adjacent to both ends of the actuator 113 in the longitudinal direction, for example. The third common liquid chamber 1163 communicates with the first common liquid chamber 1161 and the two second common liquid chambers 1162 on both longitudinal end sides of the pair of actuators 113 . The third common liquid chamber 1163 forms a partial ink flow path from the first common liquid chamber 1161 to the second common liquid chamber 1162 without passing through the plurality of pressure chambers 1131 of the actuators 113 . Also, the third common liquid chamber 1163 forms an ink flow path from the first common liquid chamber 1161 and the two second common liquid chambers 1162 to the discharge port 1112 .

As shown in FIGS. 1 to 8, 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, and a first cooling water discharge pipe. A tube 126 , a damper 127 and a bypass channel 128 are provided. The number of ink supply pipes 123 and ink discharge pipes 124 can be set appropriately. 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 be set as appropriate.

Manifold 121 is formed in a plate-like or block-like shape. As shown in FIGS. 6 to 8, the manifold 121 is continuous with a supply port 1111 of the base plate 111 to form a liquid supply channel, and is continuous with a discharge port 1112 of the base plate 111 to form a liquid discharge channel. and a first cooling channel 1213 forming a cooling fluid flow channel. Since the manifold 121 is connected to the pair of head main bodies 11 , it has a pair of supply paths 1211 and a pair of discharge paths 1212 .

One major surface of manifold 121 is fixed to the major surface of base plate 111 . 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. In the manifold 121, 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 are fixed via the top plate 122, for example.

Manifold 121 includes, for example, first manifold 1214 and second manifold 1215 . Manifold 121 is formed by assembling first manifold 1214 and second manifold 1215 together.

The supply path 1211 is a parallelepiped liquid chamber elongated in one direction (first direction X) and formed in the manifold 121 by holes and grooves. The supply path 1211 fluidly connects the ink supply pipe 123 and the supply port 1111 of the base plate 111 .

For example, the supply path 1211 is a parallelepiped liquid chamber extending along the longitudinal direction of the actuator 113 and along the longitudinal direction of the supply port 1111 . The supply path 1211 is a liquid flow path between the ink supply pipe 123 and the supply port 1111 . One side of the supply path 1211 is connected to the supply port 1111 , and the other ceiling portion 12111 of the supply path 1211 is provided with a damper 127 .

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

The first cooling channel 1213 is a channel formed in the manifold 121 by holes or grooves. The first cooling flow path 1213 fluidly connects 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 is the liquid ejection portion.

Both ends of the primary side and the secondary side of the first cooling channel 1213 are openings connected to the first cooling water supply pipe 125 and the first cooling water discharge pipe 126 provided on one main surface of the manifold 121. . Also, the first cooling channel 1213 is formed to exchange heat with the base plate 111 fixed to the manifold 121 .

The first manifold 1214 is formed in a rectangular plate shape. The first manifold 1214 has, for example, grooves and openings forming part of the pair of supply channels 1211 , part of the pair of discharge channels 1212 and part of the first cooling channel 1213 . The grooves and openings forming part of the supply channel 1211 and the discharge channel 1212 are appropriately set in arrangement, size, etc. based on the shapes of the supply channel 1211 and the discharge channel 1212 and the shapes of other fluid flow channels. .

The second manifold 1215 is formed in a rectangular plate shape. The second manifold 1215 has, for example, grooves and openings forming part of the pair of supply channels 1211 , part of the pair of discharge channels 1212 , and part of the first cooling channel 1213 . The grooves and openings forming part of the supply channel 1211 and the discharge channel 1212 are appropriately set in arrangement, size, etc. based on the shapes of the supply channel 1211 and the discharge channel 1212 and the shapes of other fluid flow channels. .

The first manifold 1214 and the second manifold 1215 are joined together to form the supply channel 1211 , the discharge channel 1212 and the first cooling channel 1213 .

The top plate 122 is provided on the surface of the manifold 121 opposite to the surface on which the base plate 111 is provided. The top plate 122 communicates 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 with the supply channel 1211, the discharge channel 1212, and the first cooling channel 1213 of the manifold 121. It has an opening that allows For example, the top plate 122 is formed by two plate-like members. 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 are provided on one of the plate-like members. Also, 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 are provided on the other plate member.

The ink supply pipe 123 is connected to the supply path 1211 . The ink discharge pipe 124 is connected to the discharge path 1212 . In this embodiment, the liquid ejection head 1 includes a pair of head main bodies 11, and thus a pair of ink supply pipes 123 and ink discharge pipes 124 are provided. The first cooling water supply pipe 125 and the first cooling water discharge pipe 126 are connected to the primary side and secondary side of the first cooling flow path 1213 .

In this embodiment, a pair of ink supply pipes 123 and a first cooling water discharge pipe 126 are arranged at one end side of the manifold 121 in the longitudinal direction, and a pair of ink discharge pipes 124 and 124 are arranged at the other end side of the manifold 121 in the longitudinal direction. A first cooling water supply pipe 125 is arranged.

As shown in FIGS. 6 to 8, the damper 127 is formed in the shape of an elastically deformable thin film or sheet. As shown in FIG. 7, damper 127 covers ceiling portion 12111 of supply channel 1211 formed in second manifold 1215 . The damper 127 elastically deforms according to pressure fluctuations in the supply path 1211 . One surface of the damper 127 faces the supply path 1211 .

As a specific example, the damper 127 is made of a polyimide film. The damper 127 is formed in a rectangular shape that is long in one direction (first direction X) and is long in the same direction as the longitudinal direction (first direction X) of the opening of the ceiling portion 12111 of the supply path 1211 .

As shown in FIG. 6, the bypass channel 128 connects the ceiling portion 12111 of the supply channel 1211 and the common liquid chamber 116 or the secondary side of the common liquid chamber 116 . The common liquid chamber 116 connected to the bypass channel 128 or the secondary side of the common liquid chamber 116 is, for example, 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 secondary side of the common liquid chamber 116. It is the ink discharge pipe 124 . The fluid resistance of the bypass channel 128 is greater than the fluid resistance of the supply channel 1211 and the fluid resistance of the common liquid chamber 116 .

The bypass channel 128 bypasses the supply channel 1211 and the common liquid chamber 116 to discharge air bubbles in the supply channel 1211 during maintenance and ink filling. The bypass channel 128 is formed to have a rectangular or circular channel cross section. The shape of the bypass channel 128 is formed, for example, in a linear shape, a bent shape in which a part is bent, or the like.

As shown in FIGS. 2, 4, and 10, the cooling channel unit 13 includes, for example, a cooling channel portion 131, a cooling water top plate 132, a second cooling water supply pipe 133, a second cooling water and an exhaust pipe 134 . The cooling channel unit 13 is connected to the cooling device 2116 of the liquid ejection device 2 . The cooling channel unit 13 is a cooling structure that cools the driver IC 142, which is a heating element.
The cooling flow path portion 131 is connected to a second cooling water supply pipe 133 and a second cooling water discharge pipe 134 via a cooling water top plate 132 . The cooling flow path portion 131 includes a branch flow path 1311 connected to the second cooling water supply pipe 133, a second cooling flow path 1312 for cooling a plurality of driver ICs, which are heat generating portions, and a confluence flow path 1313. , provided.

The branch flow path 1311 branches the cooling water supplied from the second cooling water supply pipe 133 into two directions. One of the flow paths branched by the branch flow path 1311 is connected to the first cooling flow path 1213 , and the other flow path branched by the branch flow path 1311 is connected to the second cooling flow path 1312 .

The second cooling channel 1312 is connected to one channel branched by the branch channel 1311 . The number of the second cooling channels 1312 on the primary side is smaller than that of the plurality of driver ICs, and the channels branch into a plurality of channels, and the plurality of channels merge into one on the secondary side. to form The second cooling channel 1312 cools the driver IC 142 .

As a specific example, in this embodiment, there are four nozzle rows 1142, four actuators 113 (four rows), and four driver ICs 142 (four rows). Therefore, as shown in FIGS. 2 , 4 and 10 , the cooling channel portion 131 has three channel portions 13121 forming the second cooling channel 1312 . These three channel portions 13121 are long in one direction (first direction X) and arranged side by side in a direction (second direction Y) orthogonal to the longitudinal direction of the channel portions 13121 .

The three channel portions 13121 are configured by a pair (two) single-row cooling channel portions 13122 and one multiple-row cooling channel portion 13123 . The pair of single-row cooling channel portions 13122 are arranged on both end sides (outside) in the direction in which the three channel portions 13121 are arranged (the second direction Y). Each of the pair of single-row cooling channel portions 13122 cools one driver IC 142 that drives the actuator 113 that ejects ink from the single-row nozzle row 1142 . The corresponding driver IC 142 abuts on the outer surface of the single-row cooling channel portion 13122 .

The multiple-row cooling channel portion 13123 is arranged inside in the direction in which the three channel portions 13121 are arranged (the second direction Y). That is, the multi-row cooling channel portion 13123 is arranged between a pair of single-row cooling channel portions 13122 in the direction in which the three channel portions 13121 are arranged (the second direction Y). The multi-row cooling flow path portion 13123 cools the two driver ICs 142 that respectively drive the two actuators 113 that eject ink from two adjacent nozzle rows 1142 of the two sets of head main bodies 11 . Two corresponding driver ICs 142 abut on different outer surfaces of the multi-row cooling flow path portion 13123 .

For example, as shown in FIGS. 4 and 10, the width WA of the flow channel 131221 formed by the single-row cooling flow channel portion 13122 is larger than the width WB of the flow channel 131231 formed by the multi-row cooling flow channel portion 13123. Narrow dimensions. A width WA of the flow path 131221 and a width WB of the flow path 131231 are widths in the second direction Y direction in FIG. Further, the channel cross-sectional area of the channel 131221 formed by the single-row cooling channel portion 13122 is smaller than the channel cross-sectional area of the multi-row cooling channel portion 13123 . This is because the single-row cooling channel portion 13122 cools one driver IC 142 , whereas the multi-row cooling channel portion 13123 cools two driver ICs 142 . Therefore, in order to make the cooling capacity of the plural-row cooling channel portion 13123 higher than that of the single-row cooling channel portion 13122, the width WB of the channel 131231 of the plural-row cooling channel portion 13123 is set to the single-row cooling capacity. The channel portion 13122 is larger than the width WA of the channel 131221 .

The confluence channel 1313 joins the first cooling channel 1213 and the second cooling channel 1312 and connects to the second cooling water discharge pipe 134 .

Such a cooling channel portion 131 includes, for example, a cooling manifold 1314 , a cover 1315 covering the cooling manifold 1314 , and a pair of cooling blocks 1316 provided on the cover 1315 .

The second cooling channel 1312 is a channel formed by holes and grooves formed in the cooling manifold 1314 , the cover 1315 and the pair of cooling blocks 1316 .

The cooling manifold 1314 is formed in a plate shape or a block shape. Cooling manifold 1314 is fixed to manifold 121, for example. The cooling manifold 1314 is formed with two openings 13141 for arranging a portion of the wiring film 141 on which the driver IC 142 (described later) of the circuit board 14 is mounted and the printed wiring board 143 . The opening 13141 extends along the longitudinal direction (first direction X) of the flow channel portion 13121 .

In the cooling manifold 1314 , three portions adjacent to the two openings 13141 constitute part of the three channel portions 13121 respectively. For example, a groove 13142 is formed in the cooling manifold 1314 . The groove 13142 branches from one flow path into three flow paths, a flow path 131231 formed by two single-row cooling flow path portions 13122 and a flow path 131231 formed by one multiple-row cooling flow path portion 13123. and then merge.

Cover 1315 is formed in a plate shape. Two openings 13151 are formed in the cover 1315 along the longitudinal direction (first direction X) of the flow path part 13121 in which a part of the wiring film 141 and the printed wiring board 143 are arranged. Cover 1315 covers groove 13142 formed in cooling manifold 1314 and is fluid-tightly secured to cooling manifold 1314 . The cover 1315 constitutes the second cooling channel 1312 together with the cooling manifold 1314 . When the cover 1315 is integrally assembled with the cooling manifold 1314, the two openings 13151 of the cover 1315 and the opening 13141 of the cooling manifold 1314 face each other. The cover 1315 is formed with, for example, a plurality of openings that connect the second cooling channel 1312 with the branch channel 1311 and the confluence channel 1313 .

The cooling block 1316 is formed with grooves and openings that form the branch flow path 1311 or the confluence flow path 1313 inside. That is, of the pair of cooling blocks 1316 , one cooling block 1316 forms a branch flow path 1311 and the other cooling block 1316 forms a confluence flow path 1313 . Also, a pair of cooling blocks 1316 are fixed to the cover 1315 . A pair of cooling blocks 1316 face each other in the first direction X with a spacing that allows arrangement of the wiring film 141 of the circuit board 14 and a printed wiring board 143 to be described later. The cooling block 1316 has, for example, 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 . Also, the cooling block 1316 is formed with a plurality of ribs 13162 and a plurality of grooves 13163 for arranging and supporting printed wiring boards 143 (to be described later) of the four circuit boards 14, for example.

The cooling water top plate 132 is provided on the surface opposite to the surface on which the cover 1315 of the pair of cooling blocks 1316 is provided. For example, a pair of cooling water top plates 132 are provided. Each cooling water top plate 132 has an opening that connects the second cooling water supply pipe 133 or the second cooling water discharge pipe 134 to the branch flow path 1311 or the confluence flow path 1313 of the cooling block 1316 . The cooling water top plate 132 is formed with a plurality of grooves in which, for example, the printed wiring board 143 is arranged and supported.

As shown in FIGS. 1 to 4, 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.

The circuit board 14 drives the actuator 113 by applying a drive voltage to the actuator 113 through the wiring pattern of the base plate 111 by the driver IC 142 , increases or decreases the volume of the pressure chamber 1131 , and ejects droplets from the nozzle 1141 . .

The wiring film 141 is a film substrate formed in a so-called film shape and having a wiring pattern formed thereon. For example, a plurality of wiring films 141 are provided. The wiring film 141 is, for example, a COF (Chip on Film) on which the driver IC 142 is mounted. For example, the wiring films 141 are provided in the same number as the actuators 113 provided in one head main body 11 , that is, in the same number as the nozzle rows 1142 . One wiring film 141 is connected to one actuator 113 . A plurality of wiring films 141 may be connected to one actuator 113. In this case, a plurality of wiring films 141 and wiring film rows and The number of driver IC rows is the same as that of actuators 113 .

In this embodiment, the head main body 11 is provided with two nozzle rows 1142 (two actuators 113 ), so two wiring films 141 are provided on one head main body 11 . A liquid ejection head 1 having two sets of head bodies 11 has four wiring films 141 . The four wiring films 141 are arranged, for example, so as to extend in the third direction Z, and are arranged side by side in the second direction Y in this posture.

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 part that generates heat. 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 is the side opposite to the surface (inner surface) on the side where the two wiring films 141 of one head main body 11 face each other when they are arranged so as to extend in the third direction Z. is the aspect of In other words, the outside of the wiring film 141 means the outside of the head body 11 in the second direction Y when the center side of the head body 11 in the second direction Y is defined as the inside. For this reason, the outer surfaces of the inner two wiring films 141 of the four wiring films 141 of the two sets of head bodies 11 face each other.

The surface of the driver IC 142 opposite to the mounting surface mounted on the wiring film 141 abuts the outer surface of the flow path portion 13121 . For example, the surface of the driver IC 142 directly contacts the outer surface of the flow path section 13121 . One driver IC 142 is provided for one wiring film 141 . A plurality of driver ICs 142 may be provided to drive one actuator 113, and these plurality of driver ICs 142 may be provided on one wiring film 141 to form a driver IC array. In this case, the plurality of driver ICs 142 in the same driver IC array abut on the corresponding flow path portion 13121 .

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

The cover 15 covers or houses a portion of the head body 11 , a portion of the manifold unit 12 and the circuit board 14 .

The liquid ejection head 1 configured as described above cools the first cooling channel 1213 for cooling the head main body 11, which is the liquid ejection part, and the driver IC 142, which is the heat generating part, by the manifold unit 12 and the cooling channel unit 13. It has a second cooling channel 1312 . The cooling water supplied from 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 . Cooling water flowing through the first cooling flow path 1213 cools the head body 11 , and cooling water flowing through the second cooling flow path 1312 cools the driver IC 142 .

In addition, the second cooling channel 1312 has a plurality (three rows) of channel portions 13121 which are smaller than the plurality (four rows) of nozzle rows 1142 and the plurality (four rows) of actuators 113 . Among the plurality of flow passage portions 13121, the flow passage portions 13121 positioned on both end sides (outside) in the arrangement direction (second direction Y) are drivers corresponding to the single nozzle row 1142 (one actuator 113). A single-row cooling channel portion 13122 for cooling each IC 142 is configured. Among the plurality of flow passage portions 13121, the flow passage portion 13121 between the pair of single-row cooling flow passage portions 13122 corresponds to two rows of nozzle rows 1142 (two actuators 113), for example, two driver ICs 142. A multi-row cooling channel portion 13123 for cooling is configured. Therefore, the number of flow path portions 13121 of the second cooling flow path 1312 may be less than the number of nozzle rows 1142 (actuators 113). Therefore, the liquid ejection head 1 can be prevented from becoming large.

In addition, the width WB and the flow channel cross-sectional area of the flow channel 131231 formed in the multi-row cooling flow channel portion 13123 are the width WA and flow channel cross-sectional area of the flow channel 131221 formed in the single-row cooling flow channel portion 13122. greater than As a result, the multi-row cooling flow path portion 13123 has a high cooling function even if the two driver ICs 142 are cooled.

In addition, the second cooling channel 1312 may have a simple structure in which the driver IC is brought into contact with the outer surfaces of the plurality of channel portions 13121 through which the cooling water passes. Also, the second cooling flow path 1312 may have a simple structure in which the cooling manifold 1314, the cover 1315 and the pair of cooling blocks 1316 are integrally assembled.

Since the liquid ejection head 1 can cool the driver IC 142 , which is a heat-generating body, by the second cooling flow path 1312 , it is possible to suppress thermal damage to components around the driver IC 142 . Further, since the liquid ejection head 1 can cool the head main body 11 by the first cooling flow path 1213, it is possible to suppress deterioration of printing accuracy due to heat.

FIGS. 11 and 12 show cooling effects obtained by analytical simulation when the driver IC 142 is cooled in each of the liquid ejection head 1 of the embodiment and the liquid ejection head of the comparative example. Note that FIG. 11 shows the temperature after cooling of the outer driver IC 142 cooled by the single-row cooling channel portion 13122 . Also, FIG. 12 shows the temperature after cooling of the inner driver IC 142 cooled by the multi-row cooling channel portion 13123 .

Here, as a water cooling circulation structure used in the liquid ejection head of the comparative example, cooling channels are provided on the rear surface of each two rows of driver ICs among the four rows of outward driver ICs, that is, on the inside of each two rows, A metal heat transfer plate is provided on the surface of the driver IC to be fixed to the channel parts forming the cooling channel. The cooling channel is configured to have two channel portions. The supply side of the cooling water is one, and in order to form two flow passages, it is configured to branch in two directions and merge on the discharge side.

As shown in FIGS. 11 and 12, both the outer driver IC 142 and the inner driver IC 142 of the liquid ejection head 1 of the embodiment lower the temperature of the driver IC 142 by about −20° C. than the liquid ejection head of the comparative example. I understand that it is possible. As a result, it was found that the liquid ejection head 1 of the embodiment can obtain a high cooling effect.

A liquid ejecting apparatus 2 having the liquid ejecting head 1 will be described below with reference to FIG. 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 transport device 2115 as a support device, a cooling device 2116, a maintenance device 2117, and a control unit. 2118;

The liquid ejecting apparatus 2 conveys a recording medium to be ejected, for example, paper P, along a predetermined transport path 2001 from a medium supply unit 2112 to a medium discharge unit 2114 through an image forming unit 2113 while ejecting ink or the like. is an inkjet printer that performs an image forming process on a sheet of paper P by ejecting a liquid of .

The medium supply unit 2112 has a plurality of paper feed cassettes 21121 . The image forming section 2113 includes a support section 2120 that supports a sheet, and a plurality of head units 2130 arranged above the support section 2120 so as to face each other. The medium ejection section 2114 includes a paper ejection tray 21141 .

The support portion 2120 includes a conveying belt 21201 provided in a loop shape in a predetermined area for image formation, a support plate 21202 supporting the conveying belt 21201 from the back side, and a plurality of belt rollers 21203 provided on the back side of the conveying belt 21201 . , provided.

The head unit 2130 includes a plurality of liquid ejection heads 1 that are inkjet heads, a plurality of supply tanks 2132 as liquid tanks mounted on each of the liquid ejection heads 1, a pump 2134 that supplies ink, and the liquid ejection heads. 1 and a connection channel 2135 that connects the supply tank 2132 .

In the present embodiment, the liquid ejection head 1 is provided with four color liquid ejection heads 1 of cyan, magenta, yellow, and black, and four color supply tanks 2132 each containing ink of each color. The supply tank 2132 is connected to the liquid ejection head 1 by a connection channel 2135 .

The pump 2134 is, for example, a liquid feed pump configured by a piezoelectric pump. The pump 2134 is connected to the controller 2118 and driven and controlled by the controller 2118 .

The connection channel 2135 has a supply channel connected to the ink supply pipe 123 of the liquid ejection head 1 . Also, the connection channel 2135 includes a recovery channel connected to the ink discharge pipe 124 of the liquid ejection head 1 . For example, since the liquid ejection head 1 is non-circulating, the recovery circuit is connected to the maintenance device 2117 . Note that, for example, when the liquid ejection head 1 is of a circulation type, the recovery channel is connected to the supply tank 2132 .

The transport device 2115 transports the paper P along the transport path 2001 from the paper feed cassette 21121 of the medium supply unit 2112 to the paper discharge tray 21141 of the medium discharge unit 2114 through the image forming unit 2113 . The conveying device 2115 includes a plurality of guide plate pairs 21211-21218 arranged along the conveying path 2001 and a plurality of conveying rollers 21221-21228. The transport device 2115 supports the paper P so as to be movable relative to the liquid ejection head 1 .

The cooling device 2116 has a cooling water tank 21161, a cooling circuit 21162 such as pipes and tubes for supplying cooling water, a pump for supplying cooling water, a cooler for adjusting the temperature of the cooling water, and the like. The cooling device 2116 supplies the cooling water in the cooling water tank 21161 adjusted to a predetermined temperature by the cooler to the second cooling water supply pipe 133 through the cooling circuit 21162 by the pump. In addition, the cooling device 2116 recovers the water discharged from the second cooling water discharge pipe 134 through the first cooling channel 1213 and the second cooling channel 1312 to the cooling water tank 21161 through the cooling circuit 21162. do. Note that the cooler is, for example, a cooler.

The maintenance device 2117, for example, sucks and collects ink remaining on the outer surface of the nozzle plate 114 during maintenance. Further, when the liquid ejection head 1 is of a non-circulating type, the maintenance device 2117 collects the ink inside the head main body 11 from the nozzles 1141 during maintenance. Such a maintenance device 2117 has a tray, a tank, or the like for storing collected ink.

The control unit 2118 includes a CPU 21181 as an example of a processor, a ROM (Read Only Memory) that stores various programs, and a RAM (Random Access Memory) that temporarily stores various variable data and image data. and an interface unit for inputting data from the outside and outputting data to the outside.

In the liquid ejection head 1 and the liquid ejection device 2 according to the above-described embodiments, the number of the plurality of flow passages 13121 for cooling the driver IC 142, which is a heat generating portion, is smaller than the number of the nozzle rows 1142 and the number of the actuators 113. . Also, the driver IC 142 abuts on the outer surface of the channel portion 13121 . Therefore, the liquid ejection head 1 and the liquid ejection device 2 can be downsized and simplified while ensuring a high cooling function of the second cooling channel 1312 of the cooling channel unit 13, which is a cooling structure.

Note that the embodiments of the present invention are not limited to the configurations described above. For example, in the above-described example, the head body 11 is of a non-circulating type, but may be of a circulating type.

In the above example, the liquid ejection head 1 has four nozzle rows, but the present invention is not limited to this. For example, the liquid ejection head 1 may have three sets of head bodies 11 and six nozzle rows. When such a liquid ejection head 1 is used, a pair of single-row cooling channel portions 13122 are provided on both end sides in the direction in which the nozzle rows are arranged (the second direction Y). A configuration in which two (a pair of) multiple-row cooling channel portions 13123 are provided between 13122 may be adopted.

Also, in the above example, an example in which the surface of the driver IC 142 is in direct contact with the outer surface of the flow path portion 13121 has been described, but the present invention is not limited to this. For example, the driver IC 142 may be configured to contact the outer surface of the flow path portion 13121 via a sheet-like, tape-like, gel-like, or liquid-like member made of a material having high thermal conductivity.

In the above-described embodiment, the liquid ejection head 1 and the liquid ejection device 2 are used in a recording apparatus that ejects ink as liquid, but they are not limited to this. That is, the liquid ejection head 1 and the liquid ejection device 2 can be used for, for example, 3D printers, industrial manufacturing machines, and medical applications.

According to at least one of the embodiments described above, by providing a plurality of flow path portions which are in contact with the driver IC, which is smaller in number than the number of nozzle rows, the cooling structure can be downsized and simplified while ensuring a high cooling function. can be done.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... Liquid ejection head 2... Liquid ejection apparatus 11... Head main body 12... Manifold unit 13... Cooling channel unit 14... Circuit board 15... Cover 111... Base plate 112... Frame body 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 Second 1 cooling water discharge pipe 127 damper 128 bypass passage 131 cooling passage portion 132 cooling water top plate 133 second cooling water supply pipe 134 second cooling water discharge 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 row 1151 Window 1161 Third 1 common liquid chamber 1162 second common liquid chamber 1163 third common liquid chamber 1211 supply channel 1212 discharge channel 1213 first cooling channel 1214 first manifold 1215 second manifold , 1311 branch flow path 1312 second cooling flow path 1313 confluence flow path 1314 cooling manifold 1315 cover 1316 cooling block 2001 transport path 2111 housing 2112 medium Supply unit 2113 Image forming unit 2114 Medium discharge unit 2115 Conveying device 2116 Cooling device 2117 Maintenance device 2118 Control unit 2120 Supporting unit 2130 Head unit 2132 Supply tank DESCRIPTION OF SYMBOLS 2134... Pump 2135... Connection channel 12111... Ceiling part 13121... Channel part 13122... Single row cooling channel part 13123... Multiple row cooling channel part 13141... Opening 13142... Groove 13151 ... Opening 13161 ... Pipe portion 13162 ... Rib 13163 ... Groove 21121 ... Paper feed cassette 21141 ... Paper discharge tray 21161 ... Cooling water tank 21162 ... Cooling circuit 21181 ... CPU 21201 ... Conveyor belt 21202 ... Support plate 21203 ... Belt roller 21211 to 21218 ... Guide plate pair 21221 to 21228 ... Conveying roller 131221 ... Flow path 131231 ... Flow path.

Claims (5)

a liquid ejection section having a plurality of nozzle rows;
a plurality of heat generating portions corresponding to the plurality of nozzle rows;
a cooling channel portion having a plurality of channel portions, the number of which is smaller than the number of the nozzle rows, and which is in contact with the plurality of heat generating portions while the cooling water flows;
A liquid ejection head. The plurality of nozzle rows each extend in a first direction and are arranged side by side in a second direction perpendicular to the first direction,
The heat generating portion is a driver IC connected to the liquid discharge portion, and is arranged in a plurality in the second direction,
2. The flow path part according to claim 1, wherein a plurality of said flow path parts are arranged side by side in said second direction, are arranged to face one side or the other side of said driver IC in said second direction, and extend along said first direction. A liquid ejection head as described. The plurality of flow passage portions include a pair of single-row cooling flow passage portions arranged at both ends in the arrangement direction, and a multi-row cooling flow passage portion arranged between the pair of single-row cooling flow passage portions. and
In the multiple-row cooling channel portion, the heat-generating portions are arranged to face each other on both sides in the second direction, and the width of the channel in the second direction is equal to the width of the single-row cooling channel portion. 3. The liquid ejection head according to claim 2, wherein the width is larger than the width of the flow path in two directions. 4. The liquid ejection head according to claim 2, wherein said cooling channel portion has a branch channel branching into a channel for cooling said liquid ejection portion. The nozzle row is 4 rows,
The cooling channel portion has three channel portions, and has two openings in which the plurality of heating elements are arranged between the three channel portions adjacent to each other in the second direction. 5. The liquid ejection head according to claim 2.