Liquid ejection head

Abstract

To efficiently cool a drive element.SOLUTION: A liquid discharge head includes a liquid discharge unit having a discharge element substrate which has multiple discharge elements, a first wiring substrate and a second wiring substrate which are connected to the discharge element substrate and are arranged opposing each other so as to sandwich the discharge element substrate from the opposite directions, a first drive element which is installed on the first wiring substrate and is used to drive the discharge elements, a second drive element which is installed on the second wiring substrate and is used to drive the discharge elements, a first cooling member which cools the first drive element, and a second cooling member which cools the second drive element. In the opposite directions, the first cooling member, the first drive element, the second drive element and the second cooling member are arranged in this order.SELECTED DRAWING: Figure 22

Description

[Technical field]

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

[0002] High-speed recording is required for liquid ejection devices used for business, commercial, or industrial purposes. In order to achieve high-speed recording, a liquid ejection head equipped with a plurality of ejection modules and having a large ejection width in one pass has been proposed. The ejection modules of such liquid ejection heads may be equipped with driving elements for driving the ejection elements. In order to achieve high-speed recording, heat generation from the driving elements becomes an issue. Patent Document 1 describes a technology for dissipating heat from a driving element by attaching a heat sink for cooling the driving element held on a substrate in contact with the driving element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-105377 A Summary of the Invention [Problem to be solved by the invention]

[0004] In order to achieve efficient cooling, it is required to reduce the thermal resistance between the driving element and the cooling member, and to reduce the thermal resistance, it is required to reliably bring the driving element and the cooling member into close contact with each other. On the other hand, if the number of ejection elements is increased to achieve high-speed recording, the driving element will be enlarged or the number of driving elements will be increased. In the method of Patent Document 1, when the driving element is enlarged or the number of driving elements is increased, there is a risk that the cooling member cannot be properly fixed in close contact. In addition, when a flexible wiring board that is flexible and has a high degree of layout freedom is used as the board on which the driving element is mounted, a support member for fixing the cooling member and the driving element in close contact is required, which may lead to an increase in head size.

[0005] The present disclosure aims to efficiently cool a driving element. [Means for solving the problem]

[0006] A liquid ejection head according to one aspect of the present disclosure is a liquid ejection head comprising: an ejection element substrate having a plurality of ejection ports for ejecting liquid arranged in an arrangement direction, and a plurality of ejection elements configured to generate energy for ejecting liquid from the ejection ports; a first wiring substrate and a second wiring substrate connected to the ejection element substrate and arranged opposite each other so as to sandwich the ejection element substrate from an opposing direction substantially perpendicular to the arrangement direction; a first driving element provided on the first wiring substrate for driving the ejection elements, a second driving element provided on the second wiring substrate for driving the ejection elements, a first cooling member for cooling the first driving element, and a second cooling member for cooling the second driving element, wherein the first cooling member, the first driving element, the second driving element, and the second cooling member are arranged in this order in the opposing direction. Effect of the Invention

[0007] According to the present disclosure, the driving element can be cooled efficiently. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating an example of a liquid ejection device. [Diagram 2] FIG. 2 is a perspective view of a liquid ejection head. [Diagram 3] FIG. 2 is a perspective view of a liquid ejection head. [Figure 4] FIG. 2 is an exploded perspective view of the liquid ejection head. [Diagram 5] FIG. 2 is a diagram showing an electrical connection configuration of the liquid ejection head. [Figure 6] FIG. 2 is a perspective view of a liquid ejection unit. [Figure 7] FIG. 2 is a perspective view of a liquid ejection unit. [Figure 8] FIG. 2 is an exploded perspective view of the liquid ejection unit. [Figure 9] FIG. 4 is an enlarged view of an electrode portion of the liquid ejection unit. [Figure 10] FIG. [Figure 11] 4 is a plan view of the liquid ejection head assembled to the support unit, as viewed from the ejection surface side. FIG. [Figure 12] 12 is a cross-sectional view taken along the line XII-XII in FIG. [Figure 13] 13 is a cross-sectional view taken along the line XIII-XIII in FIG. [Figure 14] 14 is a cross-sectional view taken along the line XIV-XIV in FIG. [Figure 15] 5A and 5B are diagrams illustrating a connection configuration of a liquid member between a supporting unit and a liquid supply unit. [Figure 16] 4 is a cross-sectional view of a fluid connection between a liquid supply unit and a liquid supply member. FIG. [Figure 17] 11A and 11B are diagrams illustrating a connection configuration of a liquid member of the supporting unit. [Figure 18] 5A and 5B are diagrams illustrating a connection configuration of a liquid member of the liquid ejection unit. [Figure 19] 4A and 4B are diagrams showing a fluid connection configuration within the ejection element substrate. [Figure 20] FIG. [Figure 21] FIG. [Figure 22]22 is a cross-sectional view taken along line XXII-XXII in FIG. 20. [Figure 23] 5 is a cross-sectional view of an electrical connection between a liquid ejection device main body and a liquid ejection head. FIG. [Figure 24] FIG. [Diagram 25] FIG. 2 is a cross-sectional view of the cooling unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an example of an embodiment of the present disclosure will be described with reference to the drawings. However, the following description does not limit the scope of the present disclosure. As an example, the present embodiment will be described using a method of ejecting liquid by driving a piezoelectric element, but liquid ejection heads employing a thermal method of ejecting liquid by bubbles generated by a heater element and various other liquid ejection methods are also within the scope of application of the present disclosure. In other words, the liquid ejection head can be a head having any energy generating element configured to generate energy for ejecting liquid.

[0010] The present embodiment can be an inkjet recording device (recording device) in a form in which liquid such as ink is circulated between a tank and a liquid ejection head, but other forms are also possible. For example, instead of circulating the ink, tanks may be provided on the upstream side and downstream side of the liquid ejection head, and ink may flow from one tank to the other tank to cause the ink in the pressure chamber to flow. Furthermore, the device according to the present disclosure is not limited to a recording device that ejects ink, but can be a liquid ejection device that ejects any liquid.

[0011] <<First embodiment>> FIG. 1 is a schematic diagram showing an example of a liquid ejection device 10 of this embodiment. The liquid ejection device 10 includes a so-called one-pass type liquid ejection head 100 that, when recording an image in a predetermined area of ​​a recording medium 20, completes the recording of the image in the predetermined area by moving the recording medium 20 once. The liquid ejection head 100 has ejection openings arranged over a range corresponding to the entire width of the recording medium 20 (X direction in FIG. 1). The recording medium 20 is conveyed in the direction of arrow A by a conveying unit 11, and recording is performed by the liquid ejection head 100. The liquid ejection head 100 of this embodiment is a liquid ejection head 100 corresponding to a total of four colors, cyan, magenta, yellow, and black. More specifically, it has two heads for each color. Specifically, it has cyan heads 100Ca, 100Cb, magenta heads 100Ma, 100Mb, yellow heads 100Ya, 100Yb, and black heads 100Ka, 100Kb. The following description focuses on one of the eight heads. For the sake of simplicity, any one of the heads will be described as the liquid ejection head 100. The liquid ejection head of the present disclosure may be a head of any shape, and is not limited to the example shown in FIG.

[0012] In this embodiment, the direction in which the liquid is ejected (gravity direction) is defined as the +Z direction, the upstream side of the transport direction of the recording medium 20 is defined as the +Y direction, and the arrangement direction in which the ejection ports are arranged in the head is defined as the +X direction.

[0013] Fig. 2 is a perspective view of the liquid ejection head 100 of this embodiment. Fig. 3 is a perspective view of the liquid ejection head 100 of this embodiment as viewed from a different direction than that of Fig. 2. Fig. 4 is an exploded perspective view of the liquid ejection head 100 of this embodiment. The configuration of the liquid ejection head 100 will be described with reference to Figs. 2 to 4. As described above, one of the eight heads shown in Fig. 1 will be described below as the liquid ejection head 100.

[0014] As shown in Fig. 3, the liquid ejection head 100 is a head in which four ejection element substrates 210 capable of ejecting liquid are arranged in a staggered pattern on a support member 310. The liquid ejection head 100 is positioned in the main body of the liquid ejection device by a reference member 340. As shown in Fig. 2, a liquid connection part 501 and a coolant connection part 611 are provided on the upper part of the liquid ejection head 100. The liquid connection part 501 is connected to a liquid supply part 13 on the liquid ejection device main body side, and the coolant connection part 611 is connected to a coolant supply part 14 on the liquid ejection device main body side. In this way, liquid such as ink and coolant are supplied from the liquid ejection device main body to the inside of the liquid ejection head 100.

[0015] The exterior of the liquid ejection head 100 is provided with a cover member 420 and an electrical connection portion cover member 430 for covering and protecting the electric board and the electrical connection portion. As shown in FIG. 4, the liquid ejection head 100 has therein a support unit 300 including a support member 310, an electrical wiring board 400, and an electrical wiring board support member 410 for holding the electrical wiring board 400. The liquid ejection head 100 also has a liquid supply unit 500 for supplying liquid to the liquid ejection unit 200 via the support unit 300, and a cooling unit 600 for cooling the drive circuit. The liquid ejection head 100 has a plurality of liquid ejection units 200, specifically, four liquid ejection units 200. The configuration of each portion of the liquid ejection head 100 will be described in detail below.

[0016] FIG. 5 is a diagram showing the electrical connection configuration of the liquid ejection head 100 of this embodiment. The liquid ejection device main body and the ejection element substrate 210 are electrically connected via a flexible wiring substrate 250 and an electrical wiring substrate 400. The electrical wiring substrate 400 is electrically connected to a control unit (not shown) on the liquid ejection device main body side by an electrical connection terminal 402. An ejection drive signal and power required for ejection are supplied to the electrical wiring substrate 400 via the electrical connection terminal 402. The electrical wiring substrate 400 and the flexible wiring substrate 250 are electrically connected by an electrical connection portion 401. By consolidating the wiring by the electrical circuit in the electrical wiring substrate 400, the number of terminals of the electrical connection terminal 402 can be made smaller than the number of terminals of the ejection element substrate 210. This reduces the number of electrical connections that need to be removed when assembling the liquid ejection head 100 to the liquid ejection device or when replacing the liquid ejection head 100. The flexible wiring substrate 250 is provided with a drive circuit substrate 251 for driving the ejection elements of the ejection element substrate 210. The drive circuit board 251 is provided with a drive element for driving the discharge element. The discharge drive signal supplied to the electric wiring board 400 is input to the drive circuit board 251. The drive circuit board 251 performs drive control for driving each recording element according to the discharge drive signal. As shown in FIG. 5, in this embodiment, two flexible wiring boards 250, a first flexible wiring board 250a and a second flexible wiring board 250b, are provided for one liquid discharge unit 200. In the following, when describing an individual flexible wiring board, it is referred to as the first flexible wiring board 250a or the second flexible wiring board 250b, and when describing matters common to both, it is simply described as the flexible wiring board 250. In addition, the drive circuit board 251 provided on the first flexible wiring board 250a is referred to as the first drive circuit board 251a provided with the first drive element. The drive circuit board 251 provided on the second flexible wiring board 250b is referred to as the second drive circuit board 251b provided with the second drive element.In the following, when describing an individual drive circuit board, it will be referred to as the first drive circuit board 251a or the second drive circuit board 251b, and when describing matters common to both, it will be simply referred to as the drive circuit board 251.

[0017] Fig. 6 is a perspective view of the liquid ejection unit 200. Fig. 7 is a perspective view of the liquid ejection unit 200. Fig. 8 is an exploded perspective view of the liquid ejection unit 200. Fig. 9 is an enlarged view of an electrode portion of the liquid ejection unit 200. The configuration of the liquid ejection unit 200 will be described below with reference to Figs. 6 to 9.

[0018] 6 to 8, the liquid ejection unit 200 has an ejection element substrate 210 that ejects liquid, an ejection element substrate flow path member 220 that supplies liquid to the ejection element substrate 210, and a flow path member 240 that supplies liquid to the ejection element substrate flow path member 220. The liquid ejection unit 200 also has a flexible wiring substrate 250 that is electrically connected to the ejection element substrate 210, and an ejection element substrate support member 230 that is joined to the ejection surface side of the ejection element substrate 210.

[0019] As shown in FIG. 9, electrode sections 212 are provided on the thin plate sections 211 at both ends of the discharge element substrate 210. FIG. 9 is an enlarged view of one end of the discharge element substrate 210. Note that this end refers to an end in a direction intersecting the arrangement direction in which the discharge elements (or discharge ports) are arranged on the discharge element substrate 210. As shown in FIG. 9, the discharge element substrate 210 and the flexible wiring substrate 250 are electrically connected by contacting the electrodes of the electrode section 212 and the first electrical connection section 252 of the flexible wiring substrate 250. In order to prevent liquid from penetrating into this electrical connection section and to reinforce the thin plate section 211 of the discharge element substrate 210, as shown in FIG. 6 to FIG. 8, a discharge element substrate support member 230 is joined to the discharge surface side of the thin plate section 211. The flexible wiring substrate 250 is provided with a drive circuit board 251 for driving the discharge elements of the discharge element substrate 210 (see FIG. 5). As shown in Figures 7 and 8, the first flexible wiring board 250a and the second flexible wiring board 250b are arranged opposite each other so as to sandwich the ejection element substrate 210 from an opposing direction that is approximately perpendicular to the arrangement direction in which the ejection elements are arranged.

[0020] FIG. 10 is a perspective view of the support unit 300 that supports the liquid ejection unit 200. The support unit 300 has a support member 310 to which the liquid ejection unit 200 is joined, and a frame member 320 that surrounds the liquid ejection unit 200. The support unit 300 also has a liquid supply member 330 in which a flow path is formed to supply liquid to each liquid ejection unit 200 (four liquid ejection units 200 in this embodiment) via the support member 310. The support unit 300 also has a reference member 340 that has a positioning function with respect to the liquid ejection device main body, and a reference fixing member 350 for fixing the reference member 340 to the support member 310. It is preferable to select the same material for the support member 310, the frame member 320, and the liquid supply member 330, taking into consideration the influence of thermal expansion due to, for example, ink heating temperature control or environmental fluctuations. Alternatively, when different materials are used for the support member 310, the frame member 320, and the liquid supply member 330, it is preferable to select materials having linear expansion coefficients as close as possible. This makes it possible to suppress deformation of the entire support unit during thermal expansion and the associated deterioration in the positional accuracy of the ejection element substrate 210.

[0021] FIG. 11 is a plan view of the liquid ejection head in which the liquid ejection unit 200 is assembled to the support unit 300, as viewed from the ejection surface side. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 11. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 11. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 11, in which the liquid ejection unit 200 is assembled to the support unit 300 and each member is further assembled. As shown in FIGS. 12 to 14, the flow path member 240 and the liquid supply member 330 are joined to the support member 310, and each liquid flow path is fluidly connected. The periphery of the ejection element substrate support member 230 is sealed between the frame member 320 and the frame member 320 by a peripheral sealing member 360 in order to suppress liquid infiltration. The back surface (the surface opposite to the ejection port surface) of the ejection element substrate support member 230 may be sealed by a back surface sealing member 370 for reinforcement. 11, the support member 310 has three holes for inserting the reference fixing member 350. The reference fixing member 350 is fixed to these holes, and the reference member 340 is fixed to the reference fixing member 350. The reference fixing member 350 may be an integral part of the support member 310.

[0022] FIG. 15 is a diagram showing a connection configuration of the liquid member between the support unit 300 and the liquid supply unit 500 of the liquid ejection head 100 according to this embodiment. FIG. 15(a) is a perspective view from above. FIG. 15(b) is a perspective view from below. The liquid supply unit 500 has a liquid connection part 501 and is connected to the liquid supply part 13 (FIG. 2) of the liquid ejection device main body. This allows liquid to be supplied from the supply system of the liquid ejection device main body to the liquid ejection head 100, and liquid that has passed through the liquid ejection head 100 is collected to the supply system of the liquid ejection device main body. In this way, the liquid can be circulated through the path of the liquid ejection device main body and the path of the liquid ejection head 100. Inside the liquid supply unit 500, a filter (not shown) is provided that communicates with each opening of the liquid connection part 501 to remove foreign matter from the ink being supplied.

[0023] Figure 16 is a cross-sectional view of the fluid connection between liquid supply unit 500 and liquid supply member 330. Figure 16 is a cross-sectional view taken along XVI-XVI in Figure 15. Liquid flowing in from the liquid ejection device main body side through liquid connection part 501 passes through communication port 502 and is supplied to liquid supply member 330. The gap between liquid supply unit 500 and liquid supply member 330 is sealed by elastic member 503.

[0024] FIG. 17 is a diagram showing a connection configuration of the liquid flow path of the support unit 300. FIG. 18 is a diagram showing a connection configuration of the liquid flow path of the liquid discharge unit 200. The liquid supply unit 500 and the liquid supply member 330 in the support unit 300 are fluidically connected by a first communication port 331. A flow path for distributing liquid to each liquid discharge unit 200 is formed in the liquid supply member 330. In this example, a flow path for distributing liquid to four liquid discharge units 200 is formed in one liquid supply member 330. The liquid supply member 330 and the support member 310 are fluidically connected by a second communication port 311. The support member 310 and each liquid discharge unit 200 are fluidically connected by a third communication port 241 of the flow path member 240 as shown in FIG. 18. A liquid flow path 242 is formed in the flow path member 240. The flow path member 240 is fluidically connected to the discharge element substrate flow path member 220 via a fourth communication port 221. 19 is a diagram showing a fluid connection configuration in the ejection element substrate 210. The liquid that flows in from each of the fourth communication ports 221 passes through a common flow path 222 and is supplied to the ejection element substrate 210, and is ejected from the ejection port 213 by the piezoelectric element 214, which is an ejection element.

[0025] FIG. 20 is a perspective view of a cooling unit 600 for cooling the drive circuit board 251. FIG. 21 is an exploded view of the cooling unit 600. FIG. 22 is a cross-sectional view taken along the line XXII-XXII in FIG. 20. As described above, the drive circuit board 251 is disposed on the flexible wiring board 250 (see FIG. 5). FIG. 20 is a view showing a state in which the drive circuit board 251 is covered by the cooling unit 600. As shown in FIG. 20, the cooling unit 600 has a refrigerant connection part 611. The refrigerant connection part 611 is connected to the refrigerant supply part 14 (FIG. 2) of the liquid discharger body. This allows the refrigerant to be supplied from the refrigerant supply system of the liquid discharger body to the cooling unit 600, and the refrigerant that has passed through the cooling unit 600 is collected to the refrigerant supply system of the liquid discharger body. In this way, the refrigerant can circulate through the path of the liquid discharger body and the path of the cooling unit 600. The refrigerant flowing in through the refrigerant connection portion 611 branches into a refrigerant flow path formed between the first refrigerant supply member 610 and the second refrigerant supply member 620, as shown in FIG. 21. The second refrigerant supply member 620 and the cooling member 630 are fluidly connected through a seal member 670. The refrigerant branched in the second refrigerant supply member 620 circulates in a refrigerant flow path 631 formed between the cooling member 630 and the cover member 640, and flows into the second refrigerant supply member 620 again. The refrigerant flowing in the second refrigerant supply member 620 again merges into a refrigerant flow path formed between the first refrigerant supply member 610 and the second refrigerant supply member 620, and flows out from the refrigerant connection portion 611. The second refrigerant supply member 620 and the cooling member 630 are fixed by a first fixing member 680. The cooling member 630 and the cover member 640 are fixed by a second fixing member 690.

[0026] The cooling unit 600 of this embodiment has four sets of cooling members 630 and lid members 640. The second refrigerant supply member 620 is separated into two cooling systems in the Y direction. Each cooling system is provided with two sets of cooling members 630 and lid members 640. The two sets are provided so as to face each other in the Y direction. In addition, a heat conduction member 650 is provided between the two sets in the Y direction, in contact with the cooling members 630.

[0027] In the cooling unit 600 of this embodiment, four cooling members 630 are provided. In FIG. 20 and FIG. 21, the cooling members 630 to which the refrigerant is supplied from the second refrigerant supply member 620 branched to the left front side of the paper are referred to as the first cooling member 630a and the second cooling member 630b from the left front side of the paper. In the following, when describing individual cooling members, they are referred to as the first cooling member 630a and the second cooling member 630b, and when describing matters common to both, they are simply described as the cooling member 630. In addition, the heat conduction member 650 in contact with the first cooling member 630a is referred to as the first heat conduction member 650a. The heat conduction member 650 in contact with the second cooling member 630b facing the first cooling member 630a is referred to as the second heat conduction member 650b. In this way, the first cooling member 630a and the second cooling member 630b are arranged facing each other. As shown in Fig. 21, in cooling unit 600, elastic member 660 is disposed between first heat conductive member 650a and second heat conductive member 650b. As shown in Fig. 20, flexible wiring board 250 on which drive circuit board 251 is disposed is provided between heat conductive member 650 and elastic member 660, and heat conductive member 650 abuts against drive circuit board 251 (see Figs. 20 and 22). First cooling member 630a and second cooling member 630b are fixed to second refrigerant supply member 620 by first fixing member 680, respectively, while being pressed thereagainst.

[0028] In this manner, by abutting the cooling member 630 against the drive circuit board 251 with the thermally conductive member 650 sandwiched therebetween, the heat generated during operation of the drive circuit board 251 is transferred to the refrigerant in the cooling member 630. For the cooling member 630, it is preferable to select a material with as high a thermal conductivity as possible, such as aluminum, so as to facilitate the transfer of heat generated in the drive circuit board 251. An elastic member 660 is provided between the two flexible wiring boards 250, which makes it possible to reliably bring the thermally conductive member 650 into close contact with the drive circuit board 251.

[0029] As shown in FIG. 20, two flexible wiring boards 250 each having a drive circuit board 251 are arranged extending in the -Z direction from one ejection element substrate 210. The two flexible wiring boards 250 are arranged to face each other in a direction intersecting the ejection port row direction in which the ejection ports 213 are formed. More specifically, the two flexible wiring boards 250 are arranged so that the drive circuit boards 251 face each other outward. A heat conductive member 650 abuts against the side (outside) of the flexible wiring board 250 on which the drive circuit board 251 is arranged, and an elastic member 660 abuts against the side (inside) opposite to the side on which the drive circuit board 251 is arranged. A cooling member 630 abuts against the heat conductive member 650 from the outside so as to sandwich the heat conductive member 650. That is, as shown in Fig. 22, in the opposing direction in which the two flexible wiring substrates 250 face each other, the first cooling member 630a, the first driving circuit substrate 251a, the elastic member 660, the second driving circuit substrate 251b, and the second cooling member 630b are arranged in this order. This makes it possible to efficiently cool the driving circuit substrate 251. As shown in Fig. 20, in this embodiment, one cooling member 630 is configured to cool the driving circuit substrates 251 of a plurality of ejection element substrates 210.

[0030] The thermal conductive member 650 has a role of transferring heat from the drive circuit board 251 to the cooling member 630. For this reason, it is preferable that the thermal resistance of the thermal conductive member 650 is small, and therefore it is preferable that the thickness of the thermal conductive member 650 is also thin. Furthermore, in order to bring the cooling member 630 and the drive circuit board 251 into close contact with each other, it is preferable that the thermal conductive member 650 has elasticity. It is preferable that the thickness of the thermal conductive member 650 is 8 mm or less. In this embodiment, a heat dissipation sheet with a filler dispersed in an acrylic resin base is arranged as the thermal conductive member 650, and has a thermal conductivity of 2 [W / mK] and a thickness of 1 mm.

[0031] In order to reliably press the drive circuit board 251 against the cooling member 630 even if the drive circuit board 251 is tilted, the thickness of the elastic member 660 is preferably at least greater than that of the heat conduction member 650. In detail, the elastic modulus (compression strength) of the elastic member 660 is preferably 0.01 [N / cm2] or more and approximately 1.0 [N / cm2] or less.

[0032] In this embodiment, the elastic member 660 is made of a foamed material based on ethylene-propylene rubber (EPDM), and has a thickness of about 5 mm and a compressive strength of about 0.18 [N / cm2].

[0033] The material of the elastic member 660 is not limited to the above-mentioned EPDM, but may be, for example, a rubber such as chlorinated butyl rubber or urethane rubber, or a material based on silicone or elastomer.

[0034] The heat conductive member 650 is not limited to the heat conductive sheet as described above. It may be a paste-like heat conductive grease instead of a sheet-like member. Although it is preferable that the heat conductive member 650 is provided as described above, the heat conductive member 650 may not be provided.

[0035] The heat generated by the driving circuit board 251 in this embodiment is about 17 W. Four ejection element boards 210 are mounted on one liquid ejection head 100 (as shown in FIG. 1, eight liquid ejection heads 100 are mounted on the liquid ejection device 10). Two flexible wiring boards 250 are connected to the electric wiring board 400 from one ejection element board 210, and a driving circuit board 251 is mounted on each flexible wiring board 250. Therefore, a total of eight driving circuit boards 251 are mounted on the liquid ejection head 100 in this embodiment. The temperature of the coolant from the cooling unit 600 when it is introduced into the head is 30° C., and the flow rate can be set to about 8 cc / min or more and 30 cc / min or less per driving circuit board 251. That is, the flow rate of the coolant flowing through the coolant connection portion 611 in the entire liquid ejection head 100 is controlled to about 64 cc / min or more and 240 cc / min or less. As a result, the temperature of the drive circuit board 251 is maintained at 80° C. or less, and more preferably at 60° C. or less.

[0036] 23 is a diagram showing a cross-sectional view of the electrical connection portion between the liquid ejection device main body and the liquid ejection head 100. An electrical wiring board 400 in the liquid ejection head 100 is provided with an electrical connection terminal 402. The electrical connection terminal 402 is connected to the liquid ejection device electrical wiring section 12, thereby electrically connecting the liquid ejection device 10 and the liquid ejection head 100. The periphery of the electrical connection terminal 402 is covered with an electrical connection section cover member 430 that can be opened and closed.

[0037] As described above, according to this embodiment, the drive circuit board 251 having the drive elements can be efficiently cooled. That is, in this embodiment, even if the size of the drive circuit board 251 is large, the cooling member 630 can be reliably brought into contact with the drive circuit board 251 and the drive circuit board 251 can be efficiently cooled without increasing the size of the liquid ejection head 100. Also, in this embodiment, the opposing cooling members 630 are fixed by pressing the drive circuit board 251 so as to sandwich it. Therefore, it is possible to ensure thermal contact between the drive circuit board 251 and the cooling member 630 without separately providing a support member for supporting the drive circuit board 251.

[0038] <<Second embodiment>> In the first embodiment, an example was described in which elastic member 660 was disposed between first heat conductive member 650a and second heat conductive member 650b in cooling unit 600. In the present embodiment, an embodiment in which elastic member 660 is not disposed will be described. Since the basic configuration is similar to the example described in the first embodiment, differences will be mainly described.

[0039] In this embodiment, an example will be described in which the cooling member 630 is in close contact with the drive circuit board 251 via the heat conductive member 650 without providing the elastic member 660. This embodiment uses a head of the same size as the liquid ejection head 100 described in the first embodiment. For this reason, In this embodiment, the thickness (width in the Y direction) of the cooling member 630 is configured to be greater than that of the first embodiment. That is, the thickness of the cooling member 630 is configured to be greater in order to fill the space in which the elastic member 660 was arranged in the first embodiment. Also, since the elastic member 660 is not arranged, in this embodiment, the opposing flexible wiring boards 250 abut against each other.

[0040] FIG. 24 is an exploded view of the cooling unit 600. FIG. 24 is a view corresponding to FIG. 21 of the first embodiment. FIG. 25 is a cross-sectional view of the cooling unit 600. FIG. 25 is a view corresponding to FIG. 22 of the first embodiment, and is a view corresponding to the XXII-XXII cross-sectional view of FIG. 20 of the first embodiment. In this embodiment, as shown in FIG. 25, the opposing flexible wiring boards 250 abut against each other. In addition, two opposing cooling members 630 are fixed to the second refrigerant supply member 620 in a structure in which the driving circuit board 251 is sandwiched between them. As shown in FIG. 25, the opposing cooling members 630 are fixed to the second refrigerant supply member 620 in a manner in which the driving circuit boards 251 are pressed against each other. Even in such a configuration, the thermal contact between the driving circuit boards 251 and the cooling member 630 can be ensured without providing a separate support member for supporting the driving circuit boards 251.

[0041] <<Other embodiments>> In the above-described embodiment, an example has been described in which one cooling member 630 cools the drive circuit boards 251 of different liquid discharge units 200. That is, an example has been described in which the drive circuit boards 251 of two liquid discharge units 200 are cooled by two opposing cooling members. However, this is not limited to this example. One cooling member 630 may be configured to cool the drive circuit board 251 of one liquid discharge unit 200. Also, one cooling member 630 may be configured to cool the drive circuit boards 251 of three or more liquid discharge units 200.

[0042] In the above example, a flexible wiring board having a high degree of freedom in layout is used, but a configuration that does not use a flexible wiring board may be used. Even in this case, it is sufficient that the driving element can be cooled by using the cooling member 630 on the driving circuit board 251.

[0043] The disclosure of the present embodiment includes configurations typified by the following liquid ejection head examples and liquid ejection device examples.

[0044] <Configuration 1> a discharge element substrate including a plurality of discharge ports arranged in an arrangement direction for discharging liquid, and a plurality of discharge elements configured to generate energy for discharging liquid from the discharge ports; a first wiring board and a second wiring board connected to the discharge element substrate and disposed opposite to each other so as to sandwich the discharge element substrate from an opposing direction substantially perpendicular to the arrangement direction; a first driving element provided on the first wiring substrate for driving the ejection element; a second drive element provided on the second wiring substrate for driving the ejection element; A first cooling member that cools the first driving element; A second cooling member that cools the second driving element; A liquid ejection head including a liquid ejection unit having A liquid ejection head, characterized in that the first cooling member, the first driving element, the second driving element, and the second cooling member are arranged in this order in the opposing direction.

[0045] <Configuration 2> The liquid ejection head according to configuration 1, wherein the first cooling member is fixed so as to press the first driving element in the opposing direction, and the second cooling member is fixed so as to press the second driving element in the opposing direction.

[0046] <Configuration 3> A liquid ejection head as described in configuration 1 or 2, further comprising a refrigerant supply member configured to supply refrigerant to the first cooling member and the second cooling member, respectively, the first cooling member and the second cooling member being fixed to the refrigerant supply member.

[0047] <Configuration 4> The liquid ejection head according to any one of Configurations 1 to 3, wherein an elastic member is disposed between the first driving element and the second driving element in the opposing direction.

[0048] <Component 5> A liquid ejection head described in any one of configurations 1 to 4, wherein a first heat conduction member is provided between the first cooling member and the first driving element in the opposing direction, and a second heat conduction member is provided between the second cooling member and the second driving element.

[0049] <Component 6> The liquid ejection head according to Configuration 5, wherein an elastic member is disposed between the first driving element and the second driving element in the opposing direction.

[0050] <Component 7> 7. The liquid ejection head according to configuration 6, wherein a thickness of the elastic member in the opposing direction is greater than thicknesses of the first heat conductive member and the second heat conductive member.

[0051] <Component 8> 8. The liquid ejection head according to any one of configurations 1 to 7, comprising a plurality of the liquid ejection units.

[0052] <Component 9> The liquid ejection head according to configuration 8, wherein the first cooling member is in contact with the first driving elements of two or more of the liquid ejection units.

[0053] <Component 10> The liquid ejection head according to configuration 8 or 9, wherein the second cooling member is in contact with the second driving elements of two or more of the liquid ejection units.

[0054] <Component 11> 11. The liquid ejection head according to any one of configurations 8 to 10, wherein the liquid ejection units are arranged in a staggered pattern.

[0055] <Component 12> 12. The liquid ejection head according to claim 11, wherein the first cooling member and the second cooling member cool a plurality of the liquid ejection units in one row among the plurality of the liquid ejection units arranged in the staggered pattern.

[0056] <Component 13> A liquid ejection head described in any one of configurations 1 to 12, wherein the first cooling member and the second cooling member cool the first driving element and the second driving element using a refrigerant supplied from a liquid ejection device in which the liquid ejection head is mounted.

[0057] <Component 14> a discharge element substrate including a plurality of discharge ports arranged in an arrangement direction for discharging liquid, and a plurality of discharge elements configured to generate energy for discharging liquid from the discharge ports; a first wiring board and a second wiring board connected to the discharge element substrate and disposed opposite to each other so as to sandwich the discharge element substrate from an opposing direction substantially perpendicular to the arrangement direction; a first driving element provided on the first wiring substrate for driving the ejection element; a second drive element provided on the second wiring substrate for driving the ejection element; A first cooling member that cools the first driving element; A second cooling member that cools the second driving element; A liquid ejection head including a liquid ejection unit having a liquid ejection head in which the first cooling member, the first driving element, the second driving element, and the second cooling member are arranged in this order in the opposing direction; a liquid supply unit that supplies liquid to the liquid ejection head; a coolant supply unit that supplies a coolant to the liquid ejection head; A liquid ejection device comprising: [Explanation of symbols]

[0058] 100 Liquid ejection head 200 Liquid Dispensing Unit 210 Ejection element substrate 213 Discharge port 214 Piezoelectric element 250a First flexible wiring board 250b Second flexible wiring board 251a First drive circuit board 251b Second drive circuit board 630a First cooling member 630b Second cooling member

Claims

1. a discharge element substrate including a plurality of discharge ports for discharging liquid, the discharge ports being arranged in an arrangement direction that is a first direction, and a plurality of discharge elements configured to generate energy for discharging liquid from the discharge ports; a first wiring substrate and a second wiring substrate connected to the ejection element substrate and arranged opposite to each other so as to sandwich the ejection element substrate from an opposing direction that is a second direction substantially perpendicular to the arrangement direction; a first driving element provided on the first wiring substrate for driving the ejection element; a second driving element provided on the second wiring substrate for driving the ejection element; a first cooling member that cools the first driving element; a second cooling member that cools the second driving element; a refrigerant supply unit configured to supply a refrigerant to each of the first cooling member and the second cooling member; A liquid ejection head including a liquid ejection unit having the first cooling member, the first driving element, the second driving element, and the second cooling member are arranged in this order in the opposing direction, the refrigerant supply unit includes a first refrigerant supply member having a first refrigerant flow path and a second refrigerant supply member having a second refrigerant flow path connected to the first refrigerant flow path, the refrigerant flows through the first refrigerant flow path in a third direction perpendicular to the first direction and the second direction; refrigerant flows from the first refrigerant flow path to the second refrigerant flow path in the second direction, then in the third direction, and then in the second direction; the refrigerant flows from the second refrigerant flow path into each of the first cooling member and the second cooling member in the second direction, and flows within each cooling member in the first direction. A liquid ejection head characterized by:

2. 2. The liquid ejection head according to claim 1, wherein the first cooling member is fixed so as to press the first driving element in the opposing direction, and the second cooling member is fixed so as to press the second driving element in the opposing direction.

3. The liquid ejection head according to claim 1 , wherein the first cooling member and the second cooling member are fixed to the first coolant supply member and the second coolant supply member, respectively.

4. The liquid ejection head according to claim 1 , wherein an elastic member is disposed between the first driving element and the second driving element in the opposing direction.

5. A liquid ejection head as described in claim 1, wherein a first heat conduction member is provided between the first cooling member and the first driving element in the opposing direction, and a second heat conduction member is provided between the second cooling member and the second driving element.

6. The liquid ejection head according to claim 5 , wherein an elastic member is disposed between the first driving element and the second driving element in the opposing direction.

7. The liquid ejection head according to claim 6 , wherein the thickness of the elastic member in the opposing direction is greater than the thicknesses of the first heat conducting member and the second heat conducting member.

8. The liquid ejection head according to claim 1 , comprising a plurality of the liquid ejection units.

9. The liquid ejection head according to claim 8 , wherein the first cooling member is in contact with the first driving elements of two or more of the liquid ejection units.

10. The liquid ejection head according to claim 8 , wherein the second cooling member is in contact with the second driving elements of two or more of the liquid ejection units.

11. 11. The liquid ejection head according to claim 8, wherein the plurality of liquid ejection units are arranged in a staggered pattern.

12. The liquid ejection head according to claim 11 , wherein the first cooling member and the second cooling member cool a plurality of the liquid ejection units in one row among the plurality of the liquid ejection units arranged in the staggered pattern.

13. The liquid ejection head according to claim 1 , wherein the first cooling member and the second cooling member cool the first driving element and the second driving element with a refrigerant supplied from a liquid ejection device on which the liquid ejection head is mounted.

14. a first heat conducting member provided between the first cooling member and the first driving element; a second heat conducting member provided between the second cooling member and the second driving element; and In the second direction, There is no gap between the first cooling member, the first heat conducting member, and the first driving element; or The liquid ejection head according to claim 1 , wherein no gap is formed between the second cooling member, the second heat conducting member, and the second driving element.

15. a first heat conducting member provided between the first cooling member and the first driving element; a second heat conducting member provided between the second cooling member and the second driving element; an elastic member disposed between the first driving element and the second driving element; and In the second direction, 2. The liquid ejection head according to claim 1, wherein no gaps are formed between the first cooling member, the first heat conduction member, the first driving element, the elastic member, the second cooling member, the second heat conduction member, and the second driving element.

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