Liquid injection head and liquid injection device

Abstract

To minimize a liquid jet head in the jetting direction of liquid even when the number of connectors connected to an external wiring member is reduced.SOLUTION: A liquid jet head comprises: a plurality of head chips which jet liquid in a first direction; a first substrate being a rigid substrate connected to a plurality of flexible substrates provided respectively in the plurality of head chips; and a second substrate being a rigid substrate which is provided on the opposite side to the plurality of head chips with respect to the first substrate and provided with a connector. The first substrate includes first and second substrate-to-substrate connectors. The second substrate includes third and fourth substrate-to-substrate connectors. When the first and second substrate-to-substrate connectors are engaged with the third and fourth substrate-to-substrate connectors, the first substrate-to-substrate connector is connected with the third substrate-to-substrate connector while the second substrate-to-substrate connector is connected with the fourth substrate-to-substrate connector, and the connector is electrically connected with the third and fourth substrate-to-substrate connectors.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a liquid ejection head and a liquid ejection device.

Background Art

[0002] A liquid ejection device typified by an inkjet printer generally includes a liquid ejection head having a plurality of head chips that eject a liquid such as ink. A flexible substrate is provided for each of the plurality of head chips. For example, Patent Document 1 discloses a liquid ejection head having a wiring substrate connected to the flexible substrate provided for each of the plurality of head chips, and an intermediate substrate having a connector that is connected to the wiring substrate and connects to a wiring member outside the liquid ejection head. This wiring substrate and this intermediate substrate are rigid substrates. This intermediate substrate extends substantially parallel to the liquid ejection direction. This liquid ejection head aggregates the flexible substrates provided for each of the plurality of head chips at the connector of the intermediate substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since an intermediate substrate provided with a connector for aggregating the flexible substrates provided for each of the plurality of head chips extends substantially parallel to the liquid ejection direction, there is a problem that the liquid ejection head increases in size in the ejection direction.

Means for Solving the Problems

[0005] To solve the above problems, a liquid spray head according to a preferred embodiment of the present invention comprises: a plurality of head chips that spray liquid in a first direction; a first substrate which is a rigid substrate connected to a plurality of flexible substrates provided on each of the plurality of head chips; and a second substrate which is a rigid substrate provided on the side of the first substrate opposite to the plurality of head chips and provided with a connector for connecting to an external wiring member. The first substrate has a first substrate-to-substrate connector connected to the second substrate and a second substrate-to-substrate connector connected to the second substrate. The second substrate has a third substrate-to-substrate connector connected to the first substrate and a fourth substrate-to-substrate connector connected to the first substrate. The first substrate-to-substrate connector is connected to the third substrate-to-substrate connector by fitting the first substrate-to-substrate connector into the third substrate-to-substrate connector, and the second substrate-to-substrate connector is connected to the fourth substrate-to-substrate connector by fitting the second substrate-to-substrate connector into the fourth substrate-to-substrate connector. The connectors are electrically connected to the third substrate-to-substrate connector and the fourth substrate-to-substrate connector.

[0006] To solve the above problems, a liquid injection device according to a preferred embodiment of the present invention comprises a liquid injection head and an external wiring member disposed outside the liquid injection head and connected to the connector of the liquid injection head. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic diagram illustrating the liquid injection device 100 in the first embodiment. [Figure 2] A perspective view of the liquid injection head 50 and support body 41 according to the first embodiment. [Figure 3] An exploded perspective view of the liquid injection head 50 according to the first embodiment. [Figure 4] Plan view of the wiring board 51 as seen in the Z2 direction. [Figure 5] A cross-sectional view showing an example of a head tip 54. [Figure 6] Plan view of liquid injection head 50. [Figure 7] A schematic diagram illustrating the liquid injection device 100A in the first modified example. [Figure 8] Plan view of liquid injection head 50A. [Figure 9] Plan view of the liquid injection head 50B in the second modified example. [Figure 10] A schematic diagram illustrating the liquid injection device 100C in the third modified example. [Figure 11] Perspective view of the liquid injection head 50C and support body 41C. [Figure 12] Exploded perspective view of the liquid injection head 50C. [Figure 13] Plan view of the liquid injection head 50C. [Figure 14] Plan view of the liquid injection head 50D in the fourth modified example. [Modes for carrying out the invention]

[0008] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and scale of each part have been appropriately changed from those of the actual parts. Furthermore, the embodiments described below are preferred specific examples of the present invention and are subject to various technically preferred limitations, but the scope of the present invention is not limited to these embodiments unless otherwise stated in the following description.

[0009] For convenience, the following explanation will use the X, Y, and Z axes intersecting each other as appropriate. In the following explanation, one direction along the X axis is the X1 direction, and the direction opposite to the X1 direction is the X2 direction. Similarly, opposite directions along the Y axis are the Y1 and Y2 directions. Also, opposite directions along the Z axis are the Z1 and Z2 directions. Furthermore, viewing in the direction of the Z axis is sometimes simply called "planar view." The Z2 direction corresponds to the "first direction."

[0010] 1. First Embodiment 1-1. Schematic Configuration of Liquid Injection System FIG. 1 is a schematic diagram illustrating an inkjet printing apparatus 100 according to the first embodiment. The inkjet printing apparatus 100 is an inkjet printing apparatus that ejects ink, which is an example of "liquid", as droplets onto a medium M. The medium M is typically printing paper. Note that the medium M is not limited to printing paper, and may be a printing target made of any material such as a resin film or a fabric.

[0011] As shown in FIG. 1, the inkjet printing apparatus 100 includes an ink storage unit 10, a control unit 20, a conveyance mechanism 30, a movement mechanism 40, and an inkjet head 50.

[0012] The ink storage unit 10 is a container that stores ink. Specific examples of the ink storage unit 10 include containers such as a cartridge that is detachable from the inkjet printing apparatus 100, a bag-shaped ink pack formed of a flexible film, and an ink tank that can be refilled with ink.

[0013] Although not shown, the ink storage unit 10 has a plurality of containers that store inks of different types. The inks stored in the plurality of containers are not particularly limited, and examples include cyan ink, magenta ink, yellow ink, black ink, clear ink, white ink, and processing liquid. A combination of two or more of these is used. Note that the composition of the ink is not particularly limited, and may be an aqueous ink in which a coloring material such as a dye or a pigment is dissolved in an aqueous solvent, a solvent-based ink in which the coloring material is dissolved in an organic solvent, or an ultraviolet curable ink.

[0014] In this embodiment, a configuration in which four different types of inks are used is illustrated. The four types of inks are inks having different colors from each other, such as cyan ink, magenta ink, yellow ink, and black ink.

[0015] The control unit 20 controls the operations of each element of the liquid injection device 100. For example, the control unit 20 includes a processing circuit such as a CPU or an FPGA and a storage circuit such as a semiconductor memory. The CPU is an abbreviation for Central Processing Unit. The FPGA is an abbreviation for Field Programmable Gate Array. The control unit 20 outputs a drive signal D and a control signal S toward the liquid injection head 50. The drive signal D is a signal including drive pulses for driving the drive elements of the liquid injection head 50. The control signal S is a signal for specifying whether to supply the drive signal D to the drive elements.

[0016] The transport mechanism 30 transports the medium M in the transport direction DM, which is the Y1 direction, under the control of the control unit 20. The moving mechanism 40 reciprocates the liquid injection head 50 in the X1 direction and the X2 direction under the control of the control unit 20. In the example shown in FIG. 1, the moving mechanism 40 includes a substantially box-shaped support 41 called a carriage that houses the liquid injection head 50, and a transport belt 42 to which the support 41 is fixed. In addition to the liquid injection head 50, the aforementioned liquid storage unit 10 may be mounted on the support 41.

[0017] The liquid injection head 50 has a plurality of head chips 54 as will be described later, and under the control of the control unit 20, injects the ink supplied from the liquid storage unit 10 from each of the plurality of nozzles N of each head chip 54 in the injection direction, which is the Z2 direction, toward the medium M. By performing this injection in parallel with the transport of the medium M by the transport mechanism 30 and the reciprocating movement of the liquid injection head 50 by the moving mechanism 40, a predetermined image by ink is formed on the surface of the medium M. In plan view, the liquid injection head 50 is rectangular or substantially rectangular. Here, "substantially rectangular" is a concept including a shape that can be said to be substantially rectangular and a shape similar to a rectangle. A shape that can be said to be substantially rectangular is, for example, a shape obtained by chamfering the four corners of a rectangle, such as C chamfering or R chamfering. A shape similar to a rectangle is, for example, a shape such as an octagon including four sides along the rectangle and four sides shorter than each of the four sides.

[0018] 1-2. Installation status of the liquid spray head Figure 2 is a perspective view of the liquid injection head 50 and support 41 according to the first embodiment. As shown in Figure 2, the liquid injection head 50 is supported by the support 41. The support 41 is a member that supports the liquid injection head 50, and as described above, in this embodiment it is a substantially box-shaped carriage. The constituent material of the support 41 is not particularly limited, but it is preferable to use a metallic material such as stainless steel, aluminum, titanium, or magnesium alloy.

[0019] Here, the support body 41 is provided with an opening 41a and a plurality of screw holes 41b. In this embodiment, the support body 41 is substantially box-shaped with a plate-shaped bottom, for example, the bottom is provided with an opening 41a and a plurality of screw holes 41b. The liquid spray head 50 is inserted into the opening 41a and fixed to the support body 41 by screwing it using the plurality of screw holes 41b. As described above, the liquid spray head 50 is attached to the support body 41.

[0020] In the example shown in Figure 2, there is one liquid spray head 50 attached to the support 41. However, there may be two or more liquid spray heads 50 attached to the support 41. In this case, the support 41 is appropriately provided with, for example, a number or shape of openings 41a corresponding to the number of liquid spray heads 50.

[0021] 1-3. Configuration of the liquid injection head Figure 3 is an exploded perspective view of the liquid injection head 50 according to the first embodiment. As shown in Figure 3, the liquid injection head 50 has a wiring board 51, a relay board 52, a flow channel structure 53, four head chips 54_1 to 54_4, a fixing plate 55, and a cover 58. These are arranged in the order of cover 58, relay board 52, wiring board 51, flow channel structure 53, four head chips 54, and fixing plate 55 in the Z2 direction. The parts of the liquid injection head 50 will be described sequentially below. Note that the wiring board 51 is an example of a "first board". The relay board 52 is an example of a "second board". The head chips 54_1 to 54_4 are examples of "multiple head chips". Head chip 54_1 is an example of a "first head chip", head chip 54_2 is an example of a "second head chip", head chip 54_3 is an example of a "third head chip", and head chip 54_4 is an example of a "fourth head chip".

[0022] The wiring board 51 is a mounting component for electrically connecting the liquid injection head 50 to the control unit 20. The wiring board 51 is a board on which wiring is formed for transmitting various control signals and power supply voltages to the head chips 54_1 to 54_4. The wiring board 51 is a plate-shaped member that extends substantially parallel to the XY plane. In other words, the thickness direction of the wiring board 51 is along the Z axis. The wiring board 51 is a rigid board. Specifically, a rigid board is a lath epoxy board, a glass composite board, a composite board, etc., and is a rigid body. The outer shape of the wiring board 51 is rectangular or substantially rectangular in plan view.

[0023] The wiring board 51 has four openings 51c and two BtoB connectors 51d. A board-to-board connector is also called a BtoB connector. BtoB is an abbreviation for Board to Board. For simplicity of explanation, below, a board-to-board connector will be referred to as a BtoB connector. A BtoB connector is a connector that directly connects two boards without using cables. The BtoB connector in this embodiment is a so-called straight type, in which the mating surface of the connector and the surface of the board to which the connector is attached are substantially parallel. The BtoB connectors 51d are provided on the surface 51S1 of the wiring board 51 facing the Z1 direction. The wiring board 51 will be described in detail with reference to Figure 4.

[0024] Figure 4 is a plan view of the wiring board 51 as seen in the Z2 direction. The wiring board 51 has four openings 51c: opening 51c1, opening 51c2, opening 51c3, and opening 51c4. Along the X-axis, openings 51c1, 51c2, 51c3, and 51c4 are arranged in this order. The directions along the X-axis, i.e., the X1 and X2 directions, are examples of "second directions". Each of the four openings 51c extends in the direction along the Y-axis. Openings 51c1 and 51c3 are located at approximately the same position with respect to the direction along the Y-axis. Openings 51c2 and 51c4 are located at approximately the same position with respect to the direction along the Y-axis. Approximately the same includes not only cases where they are completely identical, but also cases where they can be considered approximately identical considering manufacturing tolerances. The directions along the Y-axis, namely the Y1 and Y2 directions, are examples of the "third direction".

[0025] The wiring board 51 has two BtoB connectors 51d: a first BtoB connector 51d1 and a second BtoB connector 51d2. In a plan view, the two BtoB connectors 51d extend in the direction along the Y axis. The first BtoB connector 51d1 is positioned between openings 51c1 and 51c3. The second BtoB connector 51d2 is positioned between openings 51c2 and 51c4. The first BtoB connector 51d1 is an example of a "first board-to-board connector," and the second BtoB connector 51d2 is an example of a "second board-to-board connector."

[0026] On the surface 51S1 of the wiring board 51, there are terminal rows Lf1 composed of a plurality of terminals 51f1, terminal row Lf2 composed of a plurality of terminals 51f2, terminal row Lf3 composed of a plurality of terminals 51f3, and terminal row Lf4 composed of a plurality of terminals 51f4. Terminal row Lf1 is provided between the opening 51c1 and the first BtoB connector 51d1, more specifically on the X1 direction edge of the opening 51c. Terminal row Lf2 is provided between the opening 51c2 and the second BtoB connector 51d2, more specifically on the X1 direction edge of the opening 51c2. Terminal row Lf3 is provided between the opening 51c3 and the first BtoB connector 51d1, more specifically on the X2 direction edge of the opening 51c3. The terminal row Lf4 is provided between the opening 51c4 and the second BtoB connector 51d2, more specifically, on the edge of the opening 51c4 in the X2 direction.

[0027] The first BtoB connector 51d1 has a terminal row Lg1 composed of multiple terminals 51g1 and a terminal row Lg3 composed of multiple terminals 51g3. In plan view, terminal row Lg1 is provided at the X2 end of the first BtoB connector 51d1, and terminal row Lg3 is provided at the X1 end of the first BtoB connector 51d1. One end of each of the multiple terminals 51g1 is drawn out from the housing of the first BtoB connector 51d1 onto the surface 51S1 of the wiring board 51 and fixed, and the other end is connected to multiple terminals (not shown) provided on the third BtoB connector 52d3. Each of these multiple terminals 51g1 and each of the multiple terminals 51f1 are connected by multiple wirings (not shown) provided on the wiring board 51. That is, each of the multiple terminals 51g1 is electrically connected to each of the multiple terminals 51f1. Similarly, each of the multiple terminals 51g3 is electrically connected at one end to each of the multiple terminals 51f3 via multiple wirings (not shown) provided on the wiring board 51, and at the other end to multiple terminals (not shown) provided on the third BtoB connector 52d3.

[0028] The second BtoB connector 51d2 has a terminal row Lg2 composed of multiple terminals 51g2 and a terminal row Lg4 composed of multiple terminals 51g4. In a plan view, the terminal row Lg2 is provided at the X2 end of the second BtoB connector 51d2, and the terminal row Lg4 is provided at the X1 end of the second BtoB connector 51d2. Each of the multiple terminals 51g2 is electrically connected at one end to each of the multiple terminals 51f2 via multiple wirings (not shown) provided on the wiring board 51, and at the other end to multiple terminals (not shown) provided on the fourth BtoB connector 52d4. Similarly, each of the multiple terminals 51g4 is electrically connected at one end to each of the multiple terminals 51f4 via multiple wirings (not shown) provided on the wiring board 51, and at the other end to multiple terminals (not shown) provided on the fourth BtoB connector 52d4.

[0029] The widths of terminal rows Lf1, Lf2, Lf3, and Lf4 along the Y-axis are approximately the same, and are width dy1. The widths of terminal rows Lg1, Lg2, Lg3, and Lg4 along the Y-axis are approximately the same, and are width dy2.

[0030] Let's return to the explanation in Figure 3. The flow channel structure 53 is a structure that supplies the ink stored in the liquid reservoir 10 to the four head chips 54. The flow channel structure 53 is positioned between the four head chips 54 and the wiring board 51. The flow channel structure 53 has a flow channel member 53a, four first flow channel connections 53b, four second flow channel connections 53c, and four openings 53d. The four first flow channel connections 53b and the four second flow channel connections 53c are positioned apart from each other in the direction along the Y axis. The direction along the Y axis is an example of a "direction perpendicular to the first direction". The four first channel connection sections 53b and the four second channel connection sections 53c are examples of "multiple channel connection sections". The four first channel connection sections 53b are examples of "multiple first channel connection sections", and the four second channel connection sections 53c are examples of "multiple second channel connection sections".

[0031] The four first flow path connections 53b are supply pipes for supplying ink to the four head chips 54. The four first flow path connections 53b are connected to the aforementioned liquid storage unit 10 so that they receive different types of ink from each other. The four second flow path connections 53c are discharge pipes used to discharge ink at predetermined times, such as during the initial filling of ink into the liquid spray head 50, and are connected to a discharge container or a sub-tank capable of holding liquid, which is placed between the liquid storage unit 10 and the liquid spray head 50. During normal operation, such as printing, the four second flow path connections 53c are sealed by a cap or other sealing body. When the liquid storage unit 10 is connected to the liquid spray head 50 via a circulation mechanism, the four second flow path connections 53c are normally connected to the ink recovery flow path of the circulation mechanism.

[0032] The flow channel member 53a is provided with four supply channels, each connected to one of the four first flow channel connection sections 53b and corresponding to one of the four types of ink, and four discharge channels, each connected to one of the four second flow channel connection sections 53c and corresponding to one of the four types of ink. The discharge port of each supply channel and the inlet port of each discharge channel are provided on the surface of the flow channel member 53a facing the Z2 direction.

[0033] The flow channel member 53a, although not shown in the figure, is composed of a laminate formed by stacking multiple substrates in a direction along the Z-axis. In this specification, the expression "element A and element B are stacked" is not limited to a configuration in which element A and element B are in direct contact. That is, a configuration in which another element C is interposed between element A and element B is also included in the concept of "element A and element B are stacked." Similarly, the expression "element B is formed on the surface of element A" is not limited to a configuration in which element A and element B are in direct contact. That is, even in a configuration in which element C is formed on the surface of element A and element B is formed on the surface of element C, if at least a part of element A and element B overlap in a plan view, it is included in the concept of "element B is formed on the surface of element A."

[0034] Each of the multiple substrates is appropriately provided with grooves and holes for the aforementioned supply and discharge channels. The multiple substrates are joined to each other by means of, for example, adhesive, brazing, welding, or screwing. In the following description, the multiple substrates will be described as being joined to each other by adhesive. When joined by adhesive, the multiple components are pressed after the adhesive is applied until the adhesive hardens. In addition, a sheet-like sealing member made of rubber or the like may be appropriately placed between the multiple substrates as needed. Furthermore, the number or thickness of the substrates constituting the flow channel member 53a is determined according to the shape of the supply and discharge channels and other characteristics, and is not particularly limited and is arbitrary.

[0035] The flow channel structure 53 is also a structure that houses and supports four head chips 54. The flow channel member 53a has a recess 53e that is recessed in the Z1 direction, and a plurality of screw holes 53i and a plurality of screw holes 53k. The recess 53e is the space in which the four head chips 54 are arranged. The plurality of screw holes 53i are screw holes for screwing the flow channel structure 53 to the support 41. The plurality of screw holes 53k are screw holes for screwing the cover 58 to the flow channel structure 53.

[0036] The relay board 52 is a rigid board having wiring for electrically connecting each head chip 54 and the connector 52b. The relay board 52 is a plate-shaped member that extends substantially parallel to the XY plane. In other words, the thickness direction of the relay board 52 is along the Z axis. In plan view, the outer shape of the relay board 52 is rectangular or substantially rectangular. A connector 52b is provided on the surface 52S1 of the relay board 52 facing the Z1 direction. Two BtoB connectors 52d are provided on the surface 52S2 of the relay board 52 facing the Z2 direction. The two BtoB connectors 52d extend along the Y axis. The relay board 52 has a third BtoB connector 52d3 and a fourth BtoB connector 52d4 as the two BtoB connectors 52d. The third BtoB connector 52d3 is connected to the first BtoB connector 51d1 by mating with it. The fourth BtoB connector 52d4 is connected to the second BtoB connector 51d2 by mating with it. The third BtoB connector 52d3 is an example of a "third board-to-board connector," and the fourth BtoB connector 52d4 is an example of a "fourth board-to-board connector."

[0037] Connector 52b is a connecting component for electrically connecting the liquid injection head 50 and the control unit 20. Connector 52b is electrically connected to the third BtoB connector 52d3 and the fourth BtoB connector 52d4. Connector 52b is any type of connector, for example, a BtoB connector. Connector 52b is electrically connected to a wiring member 59 for transmitting various signals such as control signals S and drive signals D from the control unit 20 to the liquid injection head 50. The wiring member 59 includes a flexible substrate 60 such as an FPC (Flexible Printed Circuits) or FFC (Flexible Flat Cable) that is directly or indirectly connected to the control unit 20, a rigid substrate 61, a connector 61a provided at one end of the rigid substrate 61, and a BtoB connector 61b provided at the other end of the rigid substrate 61. The flexible substrate 60 is connected to connector 61a. Connector 61b is connected to connector 52b. The wiring member 59 is an example of an "external wiring member." However, the connector 52b is not limited to a BtoB connector; for example, it may be a connector into which the flexible circuit board 60 connected to the control unit 20 is directly inserted, or it may be a connector connected to a connector provided at one end of the flexible circuit board 60 on the liquid spray head 50 side.

[0038] Each head tip 54 ejects ink. Each head tip 54 has a plurality of nozzles N for ejecting a first ink and a plurality of nozzles N for ejecting a second ink of a different type from the first ink. Here, the first ink and the second ink are two of the four types of ink mentioned above. For example, head tip 54_1 and head tip 54_2 each use two of the four types of ink as the first and second inks. Then, head tip 54_3 and head tip 54_4 each use the remaining two types of ink from the four types of ink. Note that the configuration of each head tip 54 is shown in a simplified manner in Figure 3. The configuration of the head tip 54 will be described in detail later based on Figure 5.

[0039] The fixing plate 55 is a plate-shaped member to which the four head tips 54 and the flow channel structure 53 are fixed. Specifically, the fixing plate 55 is positioned so that the four head tips 54 are sandwiched between it and the flow channel structure 53, and each head tip 54 and the flow channel structure 53 are fixed with adhesive or the like. Since each head tip 54 is fixed to the fixing plate 55, it is fixed in approximately the same position with respect to the direction along the Z axis. The fixing plate 55 is provided with a plurality of openings 55a that expose the nozzle surfaces FN of the four head tips 54. In the example shown in Figure 3, the plurality of openings 55a are provided individually for each head tip 54. The fixing plate 55 is made of a metal material such as stainless steel, titanium and magnesium alloy, for example.

[0040] The cover 58 is a box-shaped component that houses the relay substrate 52. The cover 58 is made of a resin material such as modified polyphenylene ether resin, polyphenylene sulfide resin, or polypropylene resin.

[0041] The cover 58 is provided with an opening 58a, four through holes 58b, and four through holes 58c. The aforementioned connector 52b is passed through the opening 58a from the inside to the outside of the cover 58. Each of the four through holes 58b corresponds to each of the four first flow path connection parts 53b, and the corresponding first flow path connection part 53b is inserted into each of them. Each of the four through holes 58c corresponds to each of the four second flow path connection parts 53c, and the corresponding second flow path connection part 53c is inserted into each of them.

[0042] 1-4. Head Tip Configuration Figure 5 is a cross-sectional view showing an example of a head tip 54. The head tip 54 has a plurality of nozzles N arranged in the direction along the Y axis. These plurality of nozzles N are divided into a first row L1 and a second row L2, which are spaced apart from each other in the direction along the X axis. Each of the first row L1 and the second row L2 is a collection of a plurality of nozzles N arranged linearly in the direction along the Y axis.

[0043] The head tip 54 has a configuration that is approximately symmetrical with respect to the X-axis. However, the positions of the multiple nozzles N in the first row L1 and the multiple nozzles N in the second row L2 along the Y-axis may coincide or differ. Figure 5 illustrates a configuration in which the positions of the multiple nozzles N in the first row L1 and the multiple nozzles N in the second row L2 along the Y-axis coincide.

[0044] As shown in Figure 5, the head chip 54 includes a communication plate 54a, a pressure chamber substrate 54b, a nozzle plate 54c, a vibration absorber 54d, a diaphragm 54e, a plurality of piezoelectric elements 54f, a protective substrate 54g, a case 54h, a wiring member 54i, and a drive circuit 54j.

[0045] The communication plate 54a and the pressure chamber substrate 54b are stacked in this order in the Z1 direction, forming a flow path for supplying ink to multiple nozzles N. A diaphragm 54e, multiple piezoelectric elements 54f, a protective substrate 54g, a case 54h, a wiring member 54i, and a drive circuit 54j are installed in the region located in the Z1 direction from the stacked structure consisting of the communication plate 54a and the pressure chamber substrate 54b. On the other hand, a nozzle plate 54c and a vibration absorber 54d are installed in the region located in the Z2 direction from the said stacked structure. Each element of the head chip 54 is generally a plate-shaped member that is elongated in the Y direction, and is joined to each other, for example, by adhesive. The elements of the head chip 54 will be described in order below.

[0046] The nozzle plate 54c is a plate-shaped member provided with a plurality of nozzles N in the first row L1 and the second row L2, respectively. The nozzle plate 54c extends substantially parallel to the XY plane. Each of the plurality of nozzles N is a through hole through which ink passes. Here, the surface of the nozzle plate 54c facing the Z2 direction is the nozzle surface FN. That is, the normal direction of the nozzle surface FN is the direction of the normal vector of the nozzle surface FN, which is the Z2 direction, the spray direction. The nozzle plate 54c is manufactured, for example, by processing a silicon single crystal substrate using semiconductor manufacturing technology that employs processing techniques such as dry etching or wet etching. However, other known methods and materials may be used in the manufacture of the nozzle plate 54c as appropriate. In addition, the cross-sectional shape of the nozzle N is typically circular, but is not limited to this, and may be non-circular, for example, polygonal or elliptical.

[0047] The communication plate 54a is provided with a space R1, multiple supply channels Ra, and multiple communication channels Na for each of the first row L1 and second row L2. Space R1 is a long opening extending in the direction along the Y axis when viewed in a plan view along the Z axis. Each of the supply channels Ra and communication channels Na is a through hole formed for each nozzle N. Each supply channel Ra communicates with space R1.

[0048] The pressure chamber substrate 54b is a plate-shaped member in which a plurality of pressure chambers C, referred to as cavities, are provided for each of the first row L1 and the second row L2. The plurality of pressure chambers C are arranged in the direction along the Y axis. Each pressure chamber C is formed for each nozzle N and is a long space extending in the direction along the X axis in a plan view. The communication plate 54a and the pressure chamber substrate 54b are manufactured, for example, by processing a silicon single crystal substrate using semiconductor manufacturing technology, similar to the nozzle plate 54c described above. However, other known methods and materials may be used as appropriate for the manufacture of the communication plate 54a and the pressure chamber substrate 54b.

[0049] The pressure chamber C is the space located between the communication plate 54a and the diaphragm 54e. Multiple pressure chambers C are arranged in the direction along the Y axis for each of the first row L1 and the second row L2. The pressure chamber C also communicates with the communication channel Na and the supply channel Ra, respectively. Therefore, the pressure chamber C communicates with the nozzle N via the communication channel Na and with the space R1 via the supply channel Ra.

[0050] A diaphragm 54e is positioned on the surface of the pressure chamber substrate 54b facing the Z1 direction. The diaphragm 54e is an elastically vibrating plate-shaped member. The diaphragm 54e has, for example, a first layer and a second layer, which are stacked in this order in the Z1 direction. The first layer is, for example, an elastic film composed of silicon oxide (SiO2). This elastic film is formed, for example, by thermal oxidation of one surface of a silicon single crystal substrate. The second layer is, for example, an insulating film composed of zirconium oxide (ZrO2). This insulating film is formed, for example, by forming a zirconium layer by sputtering and then thermally oxidizing the layer. Note that the diaphragm 54e is not limited to the stacked configuration of the first and second layers described above, and may be composed of a single layer or three or more layers.

[0051] On the surface of the diaphragm 54e facing the Z1 direction, multiple piezoelectric elements 54f corresponding to nozzles N are arranged as driving elements in the first row L1 and the second row L2, respectively. Each piezoelectric element 54f is a passive element that deforms in response to the supply of a driving signal D. Each piezoelectric element 54f has an elongated shape extending in the direction along the X axis in a plan view. Multiple piezoelectric elements 54f are arranged in the direction along the Y axis to correspond to multiple pressure chambers C. The piezoelectric elements 54f overlap the pressure chambers C in a plan view.

[0052] Each piezoelectric element 54f, although not shown in the figures, has a first electrode, a piezoelectric layer, and a second electrode, and these are stacked in this order in the Z1 direction. One of the first and second electrodes is an individual electrode that is spaced apart from each other for each piezoelectric element 54f, and a drive signal D is applied to this electrode. The other electrode is a common strip-shaped electrode that extends along the Y-axis so as to be continuous across the plurality of piezoelectric elements 54f, and a predetermined reference potential is supplied to this other electrode. Examples of metallic materials for these electrodes include platinum (Pt), aluminum (Al), nickel (Ni), gold (Au), and copper (Cu), and one of these can be used alone or two or more can be used in combination in the form of an alloy or stacking. The piezoelectric layer is made of a piezoelectric material such as lead zirconate titanate (Pb(Zr,Ti)O3), and for example, it is a strip-shaped layer that extends along the Y-axis so as to be continuous across the plurality of piezoelectric elements 54f. However, the piezoelectric layer may be a single unit spanning multiple piezoelectric elements 54f. In this case, the piezoelectric layer is provided with through holes extending along the X-axis in regions corresponding to the gaps between adjacent pressure chambers C in a plan view. When the diaphragm 54e vibrates in conjunction with the deformation of the piezoelectric elements 54f, the pressure in the pressure chamber C fluctuates, causing ink to be ejected from the nozzle N. Alternatively, instead of the piezoelectric elements 54f, a heating element that heats the ink in the pressure chamber C may be used as the driving element.

[0053] The protective substrate 54g is a plate-shaped member installed on the surface of the diaphragm 54e facing the Z1 direction, protecting the multiple piezoelectric elements 54f and reinforcing the mechanical strength of the diaphragm 54e. Here, the multiple piezoelectric elements 54f are housed between the protective substrate 54g and the diaphragm 54e. The protective substrate 54g is made of, for example, a resin material.

[0054] Case 54h is a case for storing ink supplied to multiple pressure chambers C. Case 54h is made of, for example, a resin material. Each of the first row L1 and second row L2 of Case 54h is provided with a space R2. Space R2 is in communication with the aforementioned space R1 and, together with space R1, functions as a reservoir R for storing ink supplied to the multiple pressure chambers C. Case 54h is provided with inlets IO for supplying ink to each reservoir R. The ink in each reservoir R is supplied to the pressure chamber C via each supply channel Ra.

[0055] The vibration absorber 54d, also called the compliance substrate, is a flexible resin film that forms the wall surface of the reservoir R and absorbs pressure fluctuations of the ink in the reservoir R. The vibration absorber 54d may also be a flexible thin plate made of metal. The surface of the vibration absorber 54d facing the Z1 direction is joined to the communication plate 54a with an adhesive or the like. On the other hand, the frame 54k is joined to the surface of the vibration absorber 54d facing the Z2 direction with an adhesive or the like. The frame 54k is a frame-shaped member that runs along the outer circumference of the vibration absorber 54d and contacts the aforementioned fixing plate 55. Here, the frame 54k is made of a metal material such as stainless steel, aluminum, titanium, and magnesium alloy.

[0056] The wiring member 54i is mounted on the surface of the diaphragm 54e facing the Z1 direction and is a flexible substrate for electrically connecting the control unit 20 and the head chip 54. The wiring member 54i is electrically connected to each piezoelectric element 54f and is a flexible wiring substrate such as COF (Chip On Film), FPC or FFC. In this embodiment, a drive circuit 54j for supplying a drive voltage to each piezoelectric element 54f is mounted on the wiring member 54i. The drive circuit 54j is a circuit that switches whether or not to supply at least a part of the waveform included in the drive signal D as a drive pulse based on the control signal S. Each head chip 54 has a wiring member 54i.

[0057] Note that the wiring member 54i_1 on the head chip 54_1 is an example of the "first flexible substrate". The wiring member 54i_2 on the head chip 54_2 is an example of the "second flexible substrate". The wiring member 54i_3 on the head chip 54_3 is an example of the "third flexible substrate". The wiring member 54i_4 on the head chip 54_4 is an example of the "fourth flexible substrate".

[0058] 1-5. Positional relationship between the wiring board 51, the relay board 52, and the head chip 54 The positional relationship between the wiring board 51, the intermediate board 52, and the head chip 54 will be explained using Figure 6. Figure 6 is a plan view of the liquid injection head 50. However, in Figure 6, in order to show the positional relationship between the wiring board 51, the intermediate board 52, and the four head chips 54, the cover 58 is omitted and the outlines of the intermediate board 52 and the head chips 54_1 to 54_4 are shown. The outlines of the head chips 54_1 to 54_4 are the outlines of the outer shapes of their respective cases 54h.

[0059] As shown in Figure 6, when viewed in the Z2 direction, the intermediate board 52 is smaller than the wiring board 51. Also, when viewed in the Z2 direction, the first BtoB connector 51d1 and the second BtoB connector 51d2 are located inside the smallest rectangle RE that encloses the head chips 54_1 to 54_4. When viewed in the Z2 direction, the intermediate board 52 overlaps with part or all of one or more of the wiring members 54i of the four head chips 54_1 to 54_4. Overlapping of two objects means that part or all of one object overlaps with part or all of the other object. More specifically, when viewed in the Z2 direction, the intermediate board 52 overlaps with part of wiring member 54i_1, all of wiring member 54i_2, all of wiring member 54i_3, and part of wiring member 54i_4.

[0060] Wiring member 54i_1 is inserted through opening 51c1 and connected to multiple terminals 51f1. Wiring member 54i_2 is inserted through opening 51c2 and connected to multiple terminals 51f2. Wiring member 54i_3 is inserted through opening 51c3 and connected to multiple terminals 51f3. Wiring member 54i_4 is inserted through opening 51c4 and connected to multiple terminals 51f4. Head chip 54_1 is an example of "one head chip adjacent to the other via the first board-to-board connector," and head chip 54_3 is an example of "the other head chip adjacent to the other via the first board-to-board connector." Multiple terminals 51f1 are an example of "multiple first terminals." Multiple terminals 51f3 are an example of "multiple second terminals." Aperture 51c1 is an example of a "first aperture." Aperture 51c3 is an example of a "second aperture."

[0061] The first BtoB connector 51d1 is electrically connected to wiring members 54i_1 and 54i_3 and is positioned between wiring members 54i_1 and 54i_3. The second BtoB connector 51d2 is electrically connected to wiring members 54i_2 and 54i_4 and is positioned between wiring members 54i_2 and 54i_4. To avoid complexity in the diagram, the BtoB connector 52d is not shown in Figure 6, but since the third BtoB connector 52d3 is mated with the first BtoB connector 51d1, in plan view the third BtoB connector 52d3 is also positioned between wiring members 54i_1 and 54i_3. Similarly, the fourth BtoB connector 52d4 is also positioned between wiring members 54i_2 and 54i_4.

[0062] Since openings 51c1, 51c2, 51c3, and 51c4 are arranged in this order along the X-axis, head tips 54_1, 54_2, 54_3, and 54_4 are also arranged in this order according to opening 51c. Since openings 51c1 and 51c3 are positioned at approximately the same location along the Y-axis, head tips 54_1 and 54_3 are also positioned at approximately the same location along the Y-axis. Since openings 51c2 and 51c4 are positioned at approximately the same location along the Y-axis, head tips 54_2 and 54_4 are also positioned at approximately the same location along the Y-axis. Head tips 54_1 and 54_2 are positioned offset along the Y-axis so that they partially overlap when viewed along the X-axis. Head tips 54_3 and 54_4 are positioned offset along the Y-axis so that they partially overlap when viewed along the X-axis. In other words, head tips 54_1 to 54_4 are arranged in a staggered pattern.

[0063] The wiring member 54i_1 is connected to the wiring board 51 and has a terminal row Lm1 composed of a plurality of terminals 54m1 arranged along the Y axis. The width of the terminal row Lg1 in the direction along the Y axis is the same as the width of the terminal row Lf1 in the direction along the Y axis, and is width dy1. As can be seen from Figures 4 and 6, the width dy2 of the terminal row Lg1 in the direction along the Y axis is shorter than the width dy1 of the terminal row Lm1 in the direction along the Y axis. Note that wiring member 54i_1 is an example of a "flexible substrate provided on one of the multiple head chips". The Y1 and Y2 directions along the Y axis are an example of a "fourth direction". Multiple terminals 54m1 are an example of "multiple third terminals". Terminal row Lm1 is an example of a "first terminal row". Multiple terminals 51g1 are an example of "multiple fourth terminals". Terminal row Lg1 is an example of a "second terminal row".

[0064] As shown in Figure 6, when viewed in the Z2 direction, connector 52b overlaps with the first BtoB connector 51d1 and the second BtoB connector 51d2. The width dy4 of connector 52b in the direction along the Y axis is longer than the width dy3 of the first BtoB connector 51d1 in the direction along the Y axis shown in Figure 4.

[0065] 1-6. Summary of the First Embodiment The liquid ejection head 50 comprises head chips 54_1 to 54_4 that eject ink in the Z2 direction, a wiring board 51 which is a rigid board connected to wiring members 54i provided on each of the head chips 54_1 to 54_4, and a relay board 52 which is a rigid board provided on the side of the wiring board 51 opposite to the plurality of head chips 54, and is provided with a connector 52b for connecting to an external wiring member. The wiring board 51 has a first BtoB connector 51d1 that connects to the relay board 52 and a second BtoB connector 51d2 that connects to the relay board 52. The relay board 52 has a third BtoB connector 52d3 that connects to the relay board 52 and a fourth BtoB connector 52d4 that connects to the relay board 52. The first BtoB connector 51d1 is connected to the third BtoB connector 52d3 by mating the first BtoB connector 51d1 with the third BtoB connector 52d3. The second BtoB connector 51d2 is mated with the fourth BtoB connector 52d4, thereby connecting the second BtoB connector 51d2 to the fourth BtoB connector 52d4. Connector 52b is electrically connected to the third BtoB connector 52d3 and the fourth BtoB connector 52d4.

[0066] According to the first embodiment, since the relay board 52 combines two BtoB connectors 52d into one connector 52b, the number of connectors connected to the external wiring member can be reduced. Furthermore, the two BtoB connectors 51d and the two BtoB connectors 52d allow the wiring board 51 and the relay board 52 to extend substantially parallel to the XY plane. Therefore, according to the first embodiment, compared to an embodiment in which the relay board 52 extends perpendicular to the wiring board 51, the liquid spray head 50 can be miniaturized in the direction along the Z axis.

[0067] Furthermore, by mating the two BtoB connectors, the relay board 52 can be pushed in the Z2 direction relative to the wiring board 51, thereby connecting the two BtoB connectors. This simplifies the assembly of the liquid spray head 50 compared to the configuration in which the relay board 52 and the wiring board 51 are connected via a flexible board. Additionally, by mating the two BtoB connectors, the wiring board 51 can support the relay board 52. Therefore, the liquid spray head 50 does not need to have a configuration to support the relay board 52, thus simplifying the configuration of the liquid spray head 50.

[0068] Viewed in the Z2 direction, the relay board 52 is smaller than the wiring board 51. According to the first embodiment, compared to the embodiment in which the relay board 52 is larger than the wiring board 51, it becomes possible to miniaturize the liquid spray head 50 in a direction perpendicular to the Z-axis.

[0069] Viewed in the Z2 direction, the first BtoB connector 51d1 and the second BtoB connector 51d2 are located inside the smallest rectangular RE that encloses the head chips 54_1 to 54_4. In the configuration where part or all of the first BtoB connector 51d1 and the second BtoB connector 51d2 are located outside the rectangular RE when viewed in the Z2 direction, the liquid spray head 50 becomes larger in the direction perpendicular to the Z axis due to this externally located portion. Therefore, according to the first embodiment, the liquid spray head 50 can be made smaller in the direction perpendicular to the Z axis compared to the configuration where part or all of the first BtoB connector 51d1 and the second BtoB connector 51d2 are located outside the rectangular RE when viewed in the Z2 direction.

[0070] Viewed in the Z2 direction, the relay board 52 overlaps with part or all of one or more of the wiring members 54i among the multiple wiring members 54i. In the configuration where the relay board 52 does not overlap with all the wiring members 54i when viewed in the Z2 direction, the liquid spray head 50 becomes larger in the direction perpendicular to the Z axis due to the portion of the wiring member 54i that does not overlap with the relay board 52. Therefore, according to the first embodiment, the liquid spray head 50 can be made smaller in the direction perpendicular to the Z axis compared to the configuration where the relay board 52 does not overlap with all the wiring members 54i when viewed in the Z2 direction.

[0071] The liquid injection head 50 is positioned between the head tips 54_1 to 54_4 and the wiring board 51 and includes a flow channel structure 53 that supplies liquid to the multiple head tips. The flow channel structure 53 has multiple openings 53d through which each of the multiple wiring members 54i is inserted. According to the first embodiment, the wiring member 54i, which is a flexible substrate, can be connected to the wiring substrate 51 without having to route the wiring member 54i more than necessary by inserting it through the opening 51c.

[0072] The flow channel structure 53 has a plurality of flow channel connection parts for connecting to an external flow channel member. The plurality of flow channel connection parts include a first flow channel connection part 53b and a second flow channel connection part 53c, which are spaced apart from each other in a direction perpendicular to the Z2 direction. The wiring board 51 is positioned between the first flow channel connection part 53b and the second flow channel connection part 53c in a direction perpendicular to the Z2 direction.

[0073] Head chips 54_1 to 54_4 include head chips 54_1 and 54_3 which are adjacent to each other via a first BtoB connector 51d1. The wiring board 51 has an opening 51c1 through which the wiring member 54i of head chip 54_1 is inserted, an opening 51c3 through which the wiring member 54i of head chip 54_3 is inserted, a plurality of terminals 51f1 provided between the first BtoB connector 51d1 and the opening 51c1, and a plurality of terminals 51f3 provided between the first BtoB connector 51d1 and the opening 51c3. The wiring member 54i_1 of head chip 54_1 is connected to the plurality of terminals 51f1, and the wiring member 54i_3 of head chip 54_3 is connected to the plurality of terminals 51f3.

[0074] In the first embodiment, compared to an embodiment in which the multiple terminals 51f1 are not located between the first BtoB connector 51d1 and the opening 51c1, the distance from the multiple terminals 51f1 to the first BtoB connector 51d1 can be shortened. Therefore, according to the first embodiment, the wiring within the wiring board 51 that connects the multiple terminals 51f1 to the first BtoB connector 51d1 can be shortened, which contributes to miniaturization of the wiring board 51 in the vertical direction of the Z-axis.

[0075] Multiple head tips 54 include head tip 54_1, head tip 54_2, head tip 54_3, and head tip 54_4. Head tip 54_1 has a wiring member 54i_1. Head tip 54_2 has a wiring member 54i_2. Head tip 54_3 has a wiring member 54i_3. Head tip 54_4 has a wiring member 54i_4. Along the X-axis, head tips 54_1, 54_2, 54_3, and 54_4 are arranged in this order. Head tips 54_1 and 54_3 are positioned approximately identically with respect to the Y-axis. Head tips 54_2 and 54_4 are positioned approximately identically with respect to the Y-axis. Head tips 54_1 and 54_2 are positioned offset along the Y-axis so that they partially overlap when viewed along the X-axis. The first BtoB connector 51d1 is electrically connected to wiring member 54i_1 and wiring member 54i_3, and is positioned between wiring member 54i_1 and wiring member 54i_3. The second BtoB connector 51d2 is electrically connected to wiring member 54i_2 and wiring member 54i_4, and is positioned between wiring member 54i_2 and wiring member 54i_4.

[0076] According to the first embodiment, by arranging two BtoB connectors 51d in the empty areas of the staggered-arranged head tips 54_1 to 54_4, specifically between wiring member 54i_1 and wiring member 54i_3, and between wiring member 54i_2 and wiring member 54i_4, the empty areas can be effectively utilized, contributing to miniaturization of the liquid spray head 50 in the direction perpendicular to the Z axis.

[0077] Viewed in the Z2 direction, connector 52b overlaps with the first BtoB connector 51d1 and the second BtoB connector 51d2. According to the first embodiment, compared to an embodiment in which the connector 52b is provided in a position that does not overlap with the first BtoB connector 51d1 and the second BtoB connector 51d2, it is possible to contribute to miniaturizing the relay board 52.

[0078] The wiring member 54i_1 is connected to the wiring board 51 and has a terminal row Lm1 composed of a plurality of terminals 54m1 arranged along the Y axis. The first BtoB connector 51d1 is connected to the wiring board 51 and has a terminal row Lg1 composed of a plurality of terminals 51g1 arranged along the Y axis. As shown in Figures 4 and 6, the width dy2 of the terminal row Lg1 in the direction along the Y axis is shorter than the width dy1 of the terminal row Lm1 in the direction along the Y axis.

[0079] According to the first embodiment, compared to a configuration in which a flexible substrate is used to connect the wiring board 51 and the relay board 52, the width dy2 of the terminal row Lg1 can be reduced by using the first BtoB connector 51d1 and the third BtoB connector 52d3 to connect the wiring board 51 and the relay board 52, thereby contributing to miniaturization of the wiring board 51 in the direction perpendicular to the Z axis. In particular, as shown in Figure 6, the head chips 54_1 and 54_2 are offset in the direction along the Y axis so that they partially overlap when viewed in the direction along the X axis. Compared to a configuration in which the head chips 54_1 and 54_2 do not overlap when viewed in the direction along the X axis, the available space on the wiring board 51 is limited. Therefore, according to the first embodiment, by using the first BtoB connector 51d1 in which the width dy2 of the terminal row Lg1 is narrower than the width dy1 of the terminal row Lm1 of the flexible substrate, the first BtoB connector 51d1 for connecting to the relay board 52 can be provided even in the limited available space on the wiring board 51.

[0080] The width dy4 of connector 52b in the direction along the Y-axis is longer than the width dy3 of the first BtoB connector 51d1 in the direction along the Y-axis.

[0081] The thickness direction of the wiring board 51 and the thickness direction of the intermediate board 52 are along the Z-axis and are substantially the same direction. It can also be said that the thickness direction of the wiring board 51 and the thickness direction of the intermediate board 52 are substantially parallel to the nozzle surface FN of the nozzle plate 54c. According to the first embodiment, since the wiring board 51 and the relay board 52 are stacked and connected, the liquid spray head 50 can be miniaturized in the direction along the Z axis compared to an embodiment in which the thickness direction of the wiring board 51 and the thickness direction of the relay board 52 are different from each other.

[0082] The liquid injection device 100 includes a liquid injection head 50 and an external wiring member 59 that is located outside the liquid injection head 50 and connected to a connector of the liquid injection head 50. According to the first embodiment, compared to an embodiment in which the relay substrate 52 extends in a direction perpendicular to the wiring substrate 51, a liquid injection device 100 can be provided in which the liquid injection head 50 is miniaturized in the direction along the Z axis.

[0083] 2. Variations Each of the forms exemplified above can be modified in various ways. Specific examples of modifications are given below. Two or more forms arbitrarily selected from the following examples can be merged as appropriate, provided they do not contradict each other.

[0084] 2.1. First Variation In the first embodiment, the head tips 54_1 to 54_4 were arranged in a staggered pattern, but this is not limited to the first embodiment.

[0085] Figure 7 is a schematic diagram illustrating the liquid injection device 100A in the first modified example. The liquid injection device 100A differs from the liquid injection device 100 in that it has a liquid injection head 50A instead of the liquid injection head 50. The liquid injection head 50A has multiple head tips 54 arranged along the X axis. The liquid injection head 50A will be explained with reference to Figure 8.

[0086] Figure 8 is a plan view of the liquid injection head 50A. The liquid injection head 50A differs from the liquid injection head 50 in that it has a wiring board 51A instead of the wiring board 51, an intermediate board 52A instead of the intermediate board 52, and head chips 54_1A to 54_4A instead of head chips 54_1 to 54_4. In Figure 8, the cover 58 is omitted to show the positional relationship between the wiring board 51A, the intermediate board 52A, and the head chips 54_1A to 54_4A, and the outlines of the intermediate board 52A and the head chips 54_1A to 54_4A are shown. The outlines of the head chips 54_1A to 54_4A are the outlines of the outer shape of their respective cases 54h.

[0087] The wiring board 51A differs from the wiring board 51 in that it has four openings 51cA instead of four openings 51c, two BtoB connectors 51dA instead of two BtoB connectors 51d, a terminal row Lf1A instead of terminal row Lf1, a terminal row Lf2A instead of terminal row Lf2, a terminal row Lf3A instead of terminal row Lf3, and a terminal row Lf4A instead of terminal row Lf4. The four openings 51cA differ from the four openings 51c in that the positions of each of the four openings 51cA relative to the wiring board 51A are different from the positions of each of the four openings 51c relative to the wiring board 51. The two BtoB connectors 51dA differ from the BtoB connector 51d in that the respective positions of the two BtoB connectors 51d relative to the wiring board 51A are different from the respective positions of the two BtoB connectors 51d relative to the wiring board 51. The head chips 54_1A~54_4A differ from the head chips 54_1~54_4 in that the respective positions of the head chips 54_1A~54_4A relative to the wiring board 51A are different from the respective positions of the head chips 54_1~54_4 relative to the wiring board 51.

[0088] The wiring board 51A has four openings 51cA: opening 51c1A, opening 51c2A, opening 51c3A, and opening 51c4A. Along the X-axis, openings 51c1A, 51c2A, 51c3A, and 51c4A are arranged in this order. In the first modified example, the direction along the X-axis, i.e., the X1 direction and the X2 direction, is an example of the "second direction". Each of the openings 51cA is positioned at approximately the same location with respect to the direction along the Y-axis. A wiring member 54i_1 is inserted through opening 51c1A. A wiring member 54i_2 is inserted through opening 51c2A. A wiring member 54i_3 is inserted through opening 51c3A. A wiring member 54i_4 is inserted through opening 51c4A.

[0089] The wiring board 51A has two BtoB connectors 51dA: a first BtoB connector 51d1A and a second BtoB connector 51d2A. In plan view, the two BtoB connectors 51d extend in the direction along the Y axis. The first BtoB connector 51d1A is positioned between openings 51c1A and 51c2A. The second BtoB connector 51d2A is positioned between openings 51c3A and 51c4A.

[0090] Terminal row Lf1A consists of multiple terminals 51f1A. The multiple terminals 51f1A are located between the opening 51c1A and the first BtoB connector 51d1A, more specifically on the X1-direction edge of the opening 51c1A. Terminal row Lf2A consists of multiple terminals 51f2A. The multiple terminals 51f2A are located between the opening 51c2A and the first BtoB connector 51d1A, more specifically on the X2-direction edge of the opening 51c2A. Terminal row Lf3A consists of multiple terminals 51f3A. The multiple terminals 51f3A are located between the opening 51c3A and the second BtoB connector 51d2A, more specifically on the X1-direction edge of the opening 51c3A. Terminal row Lf4A consists of multiple terminals 51f4A. Multiple terminals 51f4A are provided between the opening 51c4A and the second BtoB connector 51d2A, more specifically, on the edge of the opening 51c4A in the X2 direction.

[0091] The wiring board 51A has multiple wires (not shown) for connecting a terminal (not shown) provided on the first BtoB connector 51d1A to a plurality of terminals 51f1A, and multiple wires (not shown) for connecting a plurality of terminals (not shown) provided on the first BtoB connector 51d1A to a plurality of terminals 51f2A. Similarly, the wiring board 51A also has multiple wires (not shown) for a plurality of terminals 51f3A and a plurality of terminals 51f4A.

[0092] Intermediate board 52A differs from intermediate board 52 in that it has connector 52bA instead of connector 52b, and two BtoB connectors 52dA instead of two BtoB connectors 52d. Connector 52bA differs from connector 52b in that it extends in the direction along the X axis.

[0093] The relay board 52A has two BtoB connectors 52dA: a third BtoB connector 52d3A and a fourth BtoB connector 52d4A. In a plan view, the two BtoB connectors 52dA extend in the direction along the Y axis. The third BtoB connector 52d3A is connected to the first BtoB connector 51d1A by mating with it. The fourth BtoB connector 52d4A is connected to the second BtoB connector 51d2A by mating with it.

[0094] As shown in Figure 8, in a plan view, head chips 54_1A and 54_2A are located adjacent to each other via a first BtoB connector 51d1A. In a plan view, head chips 54_3A and 54_4A are located adjacent to each other via a second BtoB connector 51d2A. Wiring member 54i_1 is connected to a plurality of terminals 51f1A. Wiring member 54i_2 is connected to a plurality of terminals 51f2A.

[0095] Compared to a configuration in which the multiple terminals 51f1A are not located between the first BtoB connector 51d1A and the opening 51c1A, the distance from the multiple terminals 51f1A to the first BtoB connector 51d1A can be shortened. Therefore, according to the first modified example, the wiring within the wiring board 51A that connects the multiple terminals 51f1A to the first BtoB connector 51d1A can be shortened, which contributes to miniaturizing the wiring board 51A in the vertical direction of the Z-axis. In the first modified example, head chip 54_1A is an example of "one head chip adjacent to the other via the first board-to-board connector," and head chip 54_2A is an example of "the other head chip adjacent to the other via the first board-to-board connector." Aperture 51c1A is an example of a "first aperture." Aperture 51c2A is an example of a "second aperture." Multiple terminals 51f1A are an example of "multiple first terminals." Multiple terminals 51f2A are an example of "multiple second terminals."

[0096] As shown in Figure 8, in the Z2 direction, the intermediate board 52A is smaller than the wiring board 51A. In the Z2 direction, the first BtoB connector 51d1A and the second BtoB connector 51d2A are located inside the smallest rectangular REA that encloses the head chips 54_1 to 54_4. In the Z2 direction, the intermediate board 52A overlaps with part or all of one or more of the wiring members 54i of each of the four head chips 54_1A to 54_4A. More specifically, in the Z2 direction, the intermediate board 52A overlaps with part of wiring member 54i_2 and part of wiring member 54i_3. According to the first modified example, similar to the first embodiment, the liquid injection head 50A can be miniaturized in a direction perpendicular to the Z-axis.

[0097] 2.2. Second Variation In the first modified example, connector 52bA extended in the direction along the X-axis, but is not limited to this.

[0098] Figure 9 is a plan view of the liquid injection head 50B in the second modified example. The liquid injection head 50B differs from the liquid injection head 50A in that it has an intermediate substrate 52B instead of an intermediate substrate 52A. The intermediate substrate 52B differs from the intermediate substrate 52A in that it has a connector 52bB instead of a connector 52bA. The connector 52bB differs from the connector 52bA in that it extends along the Y axis.

[0099] As shown in Figure 9, in the Z2 direction, the relay board 52B is smaller than the wiring board 51A. In the Z2 direction, the first BtoB connector 51d1A and the second BtoB connector 51d2A are located inside the smallest rectangular REB that encloses the head chips 54_1 to 54_4. In the Z2 direction, the relay board 52B overlaps with part or all of one or more of the wiring members 54i of each of the four head chips 54_1A to 54_4A. More specifically, in the Z2 direction, the relay board 52B overlaps with all of the wiring member 54i_2 and all of the wiring member 54i_3. According to the second modification, similar to the first embodiment, the liquid injection head 50B can be miniaturized in the direction perpendicular to the Z-axis.

[0100] As shown in Figure 9, when viewed in the Z2 direction, connector 52bB is positioned between the first BtoB connector 51d1A and the second BtoB connector 51d2A. According to the second modified example, compared to the configuration in which the connector 52bB is located at a position other than between the first BtoB connector 51d1A and the second BtoB connector 51d2A, it is possible to miniaturize the relay board 52B.

[0101] 2.3. Third Variation In the first embodiment, the first modified example, and the second modified example, the liquid spray head 50 is rectangular or substantially rectangular in plan view, but is not limited thereto.

[0102] Figure 10 is a schematic diagram illustrating a liquid injection device 100C in a third modified example. The liquid injection device 100C differs from the liquid injection device 100 in that it has a liquid injection head 50C instead of the liquid injection head 50, and a moving mechanism 40C instead of the moving mechanism 40. In plan view, the liquid injection head 50C differs from the liquid injection head 50 in that it has a protrusion 50C1 that protrudes in the Y1 direction and a protrusion 50C2 that protrudes in the Y2 direction. The moving mechanism 40C differs from the moving mechanism 40 in that it has a support 41C instead of the support 41.

[0103] Figure 11 is a perspective view of the liquid injection head 50C and the support body 41C. The support body 41C differs from the support body 41 in that it has an opening 41aC instead of an opening 41a. The opening 41aC differs from the opening 41a in that it has a shape that corresponds to the outer shape of the liquid injection head 50C.

[0104] Figure 12 is an exploded perspective view of the liquid injection head 50C. The liquid injection head 50C differs from the liquid injection head 50 in that it has a wiring board 51C instead of the wiring board 51, a relay board 52C instead of the relay board 52, a flow path structure 53C instead of the flow path structure 53, four head chips 54_1C to 54_4C instead of the four head chips 54_1 to 54_4, a fixing plate 55C instead of the fixing plate 55, and a cover 58C instead of the cover 58.

[0105] The wiring board 51C differs from the wiring board 51C in that it has four openings 51cC instead of four openings 51c, two BtoB connectors 51dC instead of two BtoB connectors 51d, and has a shape that conforms to the outer shape of the liquid spray head 50C. The four openings 51cC differ from the four openings 51c in that the position of each of the four openings 51cC relative to the wiring board 51C is different from the position of each of the four openings 51c relative to the wiring board 51. The wiring board 51C has four openings 51cC: opening 51c1C, opening 51c2C, opening 51c3C, and opening 51c4C. The two BtoB connectors 51dC differ from the two BtoB connectors 51d in that the positions of each of the two BtoB connectors 51dC relative to the wiring board 51C are different from the positions of each of the two BtoB connectors 51d relative to the wiring board 51. The two BtoB connectors 51dC have a first BtoB connector 51d1C and a second BtoB connector 51d2C.

[0106] The relay board 52C differs from the relay board 52C in that it has two BtoB connectors 52dC instead of two BtoB connectors 51d, and its shape is adapted to the outer shape of the liquid injection head 50C. The two BtoB connectors 52dC differ from the two BtoB connectors 52d in that the positions of the two BtoB connectors 52dC relative to the relay board 52C are different from the positions of the two BtoB connectors 52d relative to the relay board 52. The two BtoB connectors 52dC have a third BtoB connector 52d3C and a fourth BtoB connector 52d4C.

[0107] The flow channel structure 53C differs from the flow channel structure 53C in that it has four openings 53dC instead of four openings 53d, has two first flow channel connection parts 53b and two second flow channel connection parts 53c, and has a shape that corresponds to the outer shape of the liquid injection head 50C. The four openings 53dC differ from the four openings 53d in that the position of the four openings 53dC relative to the flow channel structure 53C is different from the position of the four openings 53d relative to the flow channel structure 53.

[0108] The four head chips 54_1C to 54_4C differ from the head chips 54_1 to 54_4 in that the positions of each head chip 54_1C to 54_4C relative to the wiring board 51C are different from the positions of each head chip 54_1 to 54_4 relative to the wiring board 51.

[0109] The fixed plate 55C differs from the fixed plate 55 in that it has four openings 55aC instead of four openings 55a, and its shape is such that it conforms to the outer shape of the liquid injection head 50C. The four openings 55aC differ from the four openings 55a in that the positions of the four openings 55aC relative to the fixed plate 55C are different from the positions of the four openings 55a relative to the fixed plate 55.

[0110] Cover 58C differs from cover 58 in that it has two through holes 58b and its shape is in accordance with the outer shape of the liquid injection head 50C.

[0111] Figure 13 is a plan view of the liquid injection head 50C. However, in Figure 13, in order to show the positional relationship between the wiring board 51C, the relay board 52, and the four head chips 54_1C to 54_4C, the flow path structure 53 and the cover 58C are omitted, and the contours of the relay board 52C and the head chips 54_1C to 54_4C are shown. The contours of the head chips 54_1C to 54_4C are the outlines of the outer shapes of their respective cases 54h.

[0112] As shown in Figure 13, in the Z2 direction, the intermediate board 52C is smaller than the wiring board 51C. In the Z2 direction, the first BtoB connector 51d1C and the second BtoB connector 51d2C are located inside the smallest rectangular REC that encloses the head chips 54_1C to 54_4C. In the Z2 direction, the intermediate board 52 overlaps with part or all of one or more of the wiring members 54i of each of the four head chips 54_1C to 54_4C. More specifically, in the Z2 direction, the intermediate board 52C overlaps with part of wiring member 54i_2 and part of wiring member 54i_3. According to the third modification, similar to the first embodiment, the liquid injection head 50C can be miniaturized in a direction perpendicular to the Z-axis.

[0113] As shown in Figure 13, head tips 54_1C, 54_2C, 54_3C, and 54_4C are arranged along the Y-axis in this order. In the third modified example, the direction along the Y-axis, i.e., the Y1 and Y2 directions, is an example of the "second direction". Head tips 54_1C and 54_3C are positioned at approximately the same location with respect to the direction along the X-axis. The direction along the X-axis, i.e., the X1 and X2 directions, is an example of the "third direction". Head tips 54_2C and 54_4C are positioned at approximately the same location with respect to the direction along the X-axis. Head tips 54_1C and 54_3C are offset from head tips 54_2C and 54_4C in the X-axis direction. Furthermore, head tips 54_1C and 54_2C are positioned offset along the Y-axis so that they partially overlap when viewed along the X-axis. Head tips 54_2C and 54_3C are positioned offset along the Y-axis so that they partially overlap when viewed along the X-axis. Head tips 54_3C and 54_4C are positioned offset along the Y-axis so that they partially overlap when viewed along the X-axis. In other words, head tips 54_1C to 54_4C are arranged in a staggered pattern.

[0114] The first BtoB connector 51d1C is electrically connected to the wiring member 54i_1C of the head chip 54_1C and the wiring member 54i_2C of the head chip 54_2C. More specifically, the wiring board 51C has a terminal row Lf1C consisting of a plurality of terminals 51f1C on the X1 direction of the opening 51c1C, specifically on the edge of the opening 51c1C in the X1 direction. The terminal row Lf1C may be located in the X2 direction of the opening 51c1C. Furthermore, the wiring board 51C has a terminal row Lf2C consisting of a plurality of terminals 51f2C between the opening 51c2C and the first BtoB connector 51d1C, specifically on the edge of the opening 51c2C in the X2 direction. The wiring member 54i_1C is connected to the plurality of terminals 51f1C. The wiring member 54i_2C is connected to the plurality of terminals 51f2C. Furthermore, the first BtoB connector 51d1C has a terminal row Lg1C consisting of a plurality of terminals 51g1C and a terminal row Lg2C consisting of a plurality of terminals 51g2C on the surface facing the Z2 direction. In a plan view, the terminal row Lg1C is provided at the end of the first BtoB connector 51d1C in the X2 direction, and the terminal row Lg2C is provided at the end of the first BtoB connector 51d1C in the X1 direction. Each of the plurality of terminals 51g1C and each of the plurality of terminals 51f1C are connected by a plurality of wirings (not shown) provided on the wiring board 51C. Thus, the first BtoB connector 51d1C is electrically connected to the wiring member 54i_1C. Similarly, each of the plurality of terminals 51g2C and each of the plurality of terminals 51f2C are connected by a plurality of wirings (not shown) provided on the wiring board 51C. Therefore, the first BtoB connector 51d1C is electrically connected to the wiring member 54i_2C. Although not shown in the diagram, similar to the first BtoB connector 51d1C, the second BtoB connector 51d2C is electrically connected to the wiring member 54i_3C of the head chip 54_3C and the wiring member 54i_4C of the head chip 54_4C.

[0115] According to the third modified example, by placing two BtoB connectors 51dC in the empty areas of the staggered-arranged head tips 54_1C to 54_4C, specifically between wiring member 54i_1C and wiring member 54i_3C, and between wiring member 54i_2C and wiring member 54i_4C, the empty areas can be effectively utilized, contributing to the miniaturization of the liquid spray head 50C in the direction perpendicular to the Z axis.

[0116] 2.4. Fourth Variation In each of the embodiments described above, the wiring board 51 had four openings 51c for inserting the wiring member 54i, but some of the four openings 51c may have notches instead.

[0117] Figure 14 is a plan view of the liquid injection head 50D in the fourth modified example. The liquid injection head 50D differs from the liquid injection head 50 in that it has a wiring board 51D instead of a wiring board 51. The wiring board 51D differs from the wiring board 51D in that it has a notch 51h1 instead of an opening 51c1 and a notch 51h4 instead of an opening 51c4.

[0118] The notch 51h1 is provided on the edge of the wiring board 51D in the X2 direction and is recessed in the X1 direction. The wiring member 54i_1 of the head chip 54_1 is inserted through the notch 51h1. Inserting an object into a notch means that the object is inserted into the space formed by the notch. Multiple terminals 51f1 are provided between the first BtoB connector 51d1 and the notch 51h1. The wiring member 54i_1 is connected to the multiple terminals 51f1. In the fourth modified example, head chip 54_3 corresponds to "one head chip adjacent to the other via the first board-to-board connector," and head chip 54_1 corresponds to "the other head chip adjacent to the other via the first board-to-board connector." The opening 51c3 corresponds to "the first opening," and the multiple terminals 51f3 correspond to "the multiple first terminals." The multiple terminals 51f1 correspond to "the multiple second terminals provided between the first board-to-board connector and the notch."

[0119] Similar to the notch 51h1, the notch 51h4 is provided on the edge of the wiring board 51D in the X1 direction and recessed in the X2 direction. The wiring member 54i_1 of the head chip 54_4 is inserted through the notch 51h4. Multiple terminals 51f4 are provided between the second BtoB connector 51d2 and the notch 51h4. The wiring member 54i_4 is connected to the multiple terminals 51f4.

[0120] In the fourth modified example, compared to the embodiment in which the multiple terminals 51f1 are not located between the first BtoB connector 51d1 and the notch 51h1, the distance from the multiple terminals 51f1 to the first BtoB connector 51d1 can be shortened. Therefore, according to the fourth modified example, similar to the first embodiment, the wiring formed on the wiring board 51D connecting the multiple terminals 51f1 and the first BtoB connector 51d1 can be shortened, which contributes to miniaturization of the wiring board 51D in the vertical direction of the Z-axis.

[0121] 2.5. Fifth Variation In each of the embodiments described above, the flow channel structure 53 has a plurality of openings 53d through which each of the plurality of wiring members 54i is inserted, but is not limited thereto. For example, the flow channel structure 53 may have notches through which a portion of the plurality of wiring members 54i is inserted.

[0122] 2.6. Sixth Variation In each of the embodiments described above, the width dy4 of the connector 52b in the direction along the Y-axis is longer than the width dy3 of the first BtoB connector 51d1 in the direction along the Y-axis, but the width dy4 may be less than or equal to the width dy3.

[0123] 2.7. Seventh Variation In each of the embodiments described above, the number of head chips 54 in one liquid spray head 50 was four, but it is sufficient to have two or more. When the number of head chips 54 in the liquid spray head 50 is two, the first BtoB connector 51d1 is electrically connected to the wiring member 54i of one of the two head chips 54, and the second BtoB connector 51d2 is electrically connected to the wiring member 54i of the other head chip 54. Furthermore, the number of head chips 54 electrically connected to the first BtoB connector 51d1 and the number of head chips 54 electrically connected to the second BtoB connector 51d2 may be the same or different.

[0124] 2.8. Eighth Variation In the embodiments described above, a serial-type liquid injection device 100 is exemplified, in which a support 41 that supports the liquid injection head 50 is reciprocated. However, the present invention can also be applied to a line-type liquid injection device in which a plurality of nozzles N are distributed across the entire width of the medium M. That is, the support that supports the liquid injection head 50 is not limited to a serial-type carriage, but may be a structure that supports the liquid injection head 50 in a line-type configuration. In this case, for example, a plurality of liquid injection heads 50 are arranged in a line in the width direction of the medium M, and the plurality of liquid injection heads 50 are supported collectively by a single support.

[0125] 2.9. Variation 9 The liquid spraying devices exemplified in the above-described form can be used in various devices such as facsimile machines and photocopiers, in addition to equipment dedicated to printing. However, the applications of liquid spraying devices are not limited to printing. For example, liquid spraying devices that spray colorant solutions are used as manufacturing equipment for forming color filters in display devices such as liquid crystal display panels. Liquid spraying devices that spray conductive material solutions are used as manufacturing equipment for forming wiring and electrodes on wiring boards. Furthermore, liquid spraying devices that spray solutions of organic substances related to living organisms are used, for example, as manufacturing equipment for producing biochips.

[0126] 3. Addendum From the forms exemplified above, the following configuration can be understood, for example.

[0127] A liquid spray head according to Embodiment 1, which is a preferred embodiment, comprises a plurality of head chips that spray liquid in a first direction, a first substrate which is a rigid substrate connected to a plurality of flexible substrates provided on each of the plurality of head chips, and a second substrate which is a rigid substrate provided on the side of the first substrate opposite to the plurality of head chips and provided with a connector for connecting to an external wiring member, wherein the first substrate has a first substrate-to-substrate connector connected to the second substrate and a second substrate-to-substrate connector connected to the second substrate, the second substrate has a third substrate-to-substrate connector connected to the first substrate and a fourth substrate-to-substrate connector connected to the first substrate, the first substrate-to-substrate connector is connected to the third substrate-to-substrate connector by fitting the first substrate-to-substrate connector into the third substrate-to-substrate connector, the second substrate-to-substrate connector is connected to the fourth substrate-to-substrate connector by fitting the second substrate-to-substrate connector into the fourth substrate-to-substrate connector, and the connectors are electrically connected to the third substrate-to-substrate connector and the fourth substrate-to-substrate connector. According to Embodiment 1, since the second substrate consolidates two substrate-to-substrate connectors into one connector, the number of connectors connected to the external wiring member can be reduced. Furthermore, the four substrate-to-substrate connectors allow the first substrate and the second substrate to extend substantially parallel to each other. Therefore, according to Embodiment 1, the liquid spray head can be miniaturized in the first direction compared to the embodiment in which the second substrate extends perpendicular to the first substrate.

[0128] In Embodiment 2, which is a specific example of Embodiment 1, the second substrate is smaller than the first substrate when viewed in the first direction. According to embodiment 2, compared to the embodiment in which the second substrate is larger than the first substrate, it becomes possible to miniaturize the liquid spray head in a direction perpendicular to the first direction.

[0129] In Embodiment 3, which is a specific example of Embodiment 1 or Embodiment 2, the first board-to-board connector and the second board-to-board connector are located inside the smallest rectangle that encloses the plurality of head chips, when viewed in the first direction. In the configuration where, when viewed in the first direction, part or all of the first board-to-board connector and the second board-to-board connector are positioned outside the rectangle, the liquid spray head becomes larger in the first direction due to this externally positioned portion. Therefore, according to configuration 3, the liquid spray head can be made smaller in the direction perpendicular to the first direction compared to the configuration where, when viewed in the first direction, part or all of the first board-to-board connector and the second board-to-board connector are positioned outside the rectangle.

[0130] In embodiment 4, which is a specific example of any one embodiment from embodiment 1 to embodiment 3, the second substrate overlaps with part or all of one or more of the multiple flexible substrates when viewed in the first direction. In the configuration where the second substrate does not overlap with all the flexible substrates when viewed in the first direction, the liquid spray head becomes larger in the first direction due to the portion of the flexible substrate that does not overlap with the second substrate. Therefore, according to configuration 4, the liquid spray head can be made smaller in the direction perpendicular to the first direction compared to the configuration where the second substrate does not overlap with all the flexible substrates when viewed in the first direction.

[0131] In embodiment 5, which is a specific example of any one embodiment from embodiment 1 to embodiment 4, a flow channel structure is provided which is disposed between the plurality of head chips and the first substrate and supplies liquid to the plurality of head chips, and the flow channel structure has a plurality of openings through which each of the plurality of flexible substrates is inserted. According to embodiment 5, the flexible substrate can be connected to the first substrate without routing the flexible substrate unnecessarily by inserting it through the opening.

[0132] In embodiment 6, which is a specific example of embodiment 5, the flow channel structure has a plurality of flow channel connection parts for connecting to an external flow channel member, the plurality of flow channel connection parts include a first flow channel connection part and a second flow channel connection part that are spaced apart from each other in a direction perpendicular to the first direction, and the first substrate is positioned between the first flow channel connection part and the second flow channel connection part in a direction perpendicular to the first direction.

[0133] In embodiment 7, which is a specific example of any one embodiment from embodiment 1 to embodiment 6, the plurality of head chips, viewed in the first direction, include one head chip and the other head chip adjacent to each other via the first board-to-board connector, the first board has a first opening through which the flexible board of the one head chip is inserted, a second opening through which the flexible board of the other head chip is inserted, a plurality of first terminals provided between the first board-to-board connector and the first opening, and a plurality of second terminals provided between the first board-to-board connector and the second opening, the flexible board of the one head chip is connected to the plurality of first terminals, and the flexible board of the other head chip is connected to the plurality of second terminals. Compared to an embodiment where the plurality of first terminals are not located between the first board-to-board connector and the first opening, embodiment 7 allows for a shorter distance from the plurality of first terminals to the first board-to-board connector. Therefore, according to embodiment 7, the wiring formed on the first board connecting the plurality of first terminals and the first board-to-board connector can be shortened, which contributes to miniaturization of the first board in a direction perpendicular to the first direction.

[0134] In embodiment 8, which is a specific example of any one embodiment from embodiment 1 to embodiment 6, the plurality of head chips, viewed in the first direction, include one head chip and the other head chip adjacent to each other via the first substrate-to-substrate connector, the first substrate has a first opening through which the flexible substrate of the one head chip is inserted, a notch through which the flexible substrate of the other head chip is inserted, a plurality of first terminals provided between the first substrate-to-substrate connector and the first opening, and a plurality of second terminals provided between the first substrate-to-substrate connector and the notch, the flexible substrate of the one head chip is connected to the plurality of first terminals, and the flexible substrate of the other head chip is connected to the plurality of second terminals. Compared to an embodiment in which the plurality of second terminals are not located between the first board-to-board connector and the notch, embodiment 8 allows for a shorter distance from the plurality of second terminals to the first board-to-board connector. Therefore, according to embodiment 8, the wiring formed on the first board connecting the plurality of second terminals and the first board-to-board connector can be shortened, which contributes to miniaturization of the first board in a direction perpendicular to the first direction.

[0135] In embodiment 9, which is a specific example of any one embodiment from embodiment 1 to embodiment 6, the plurality of head chips include a first head chip, a second head chip, a third head chip, and a fourth head chip, wherein the first head chip has a first flexible substrate, the second head chip has a second flexible substrate, the third head chip has a third flexible substrate, and the fourth head chip is arranged in this order along a second direction perpendicular to the first direction. The first head chip and the third head chip are positioned at substantially the same location with respect to a third direction perpendicular to both the first and second directions, the second head chip and the fourth head chip are positioned at substantially the same location with respect to the third direction, the first head chip and the second head chip are positioned offset in the third direction such that they partially overlap when viewed in the second direction, the first board-to-board connector is positioned between the first flexible board and the third flexible board, and the second board-to-board connector is positioned between the second flexible board and the fourth flexible board. According to embodiment 9, by arranging a first board-to-board connector between the first flexible substrate and the third flexible substrate, and a second board-to-board connector between the second flexible substrate and the fourth flexible substrate, the available space can be effectively utilized, contributing to miniaturization of the liquid injection head in a direction perpendicular to the first direction.

[0136] In embodiment 10, which is a specific example of any one embodiment from embodiment 1 to embodiment 6, the plurality of head chips include a first head chip, a second head chip, a third head chip, and a fourth head chip, wherein the first head chip has a first flexible substrate, the second head chip has a second flexible substrate, the third head chip has a third flexible substrate, and the fourth head chip is arranged in this order along a second direction perpendicular to the first direction, the first head chip and the third head chip are arranged in substantially the same position with respect to a third direction perpendicular to both the first and second directions, and the second head chip The first and fourth head chips are positioned substantially the same with respect to the third direction, the first and second head chips are offset from each other in the third direction, the first and second head chips are offset from each other in the second direction so that they partially overlap when viewed in the third direction, the second and third head chips are offset from each other in the second direction so that they partially overlap when viewed in the third direction, the third and fourth head chips are offset from each other in the second direction so that they partially overlap when viewed in the third direction, the first board-to-board connector is positioned between the first flexible board and the third flexible board, and the second board-to-board connector is positioned between the second flexible board and the fourth flexible board. According to embodiment 10, by arranging a first board-to-board connector between the first flexible substrate and the third flexible substrate, and a second board-to-board connector between the second flexible substrate and the fourth flexible substrate, the available space can be effectively utilized, contributing to miniaturization of the liquid injection head in a direction perpendicular to the first direction.

[0137] In embodiment 11, which is a specific example of any one embodiment from embodiment 1 to embodiment 10, the connector is positioned between the first board-to-board connector and the second board-to-board connector, or overlaps with the first board-to-board connector and the second board-to-board connector, when viewed in the first direction. According to embodiment 11, compared to an embodiment in which the connector is provided in a position that does not overlap with the first board-to-board connector and the second board-to-board connector, it contributes to miniaturization of the second board.

[0138] In embodiment 12, which is a specific example of any one embodiment from embodiment 1 to embodiment 11, the flexible substrate provided on one of the plurality of head chips is connected to the first substrate and has a first terminal row composed of a plurality of third terminals arranged along a fourth direction perpendicular to the first direction, the first substrate-to-substrate connector is connected to the first substrate and has a second terminal row composed of a plurality of fourth terminals arranged along the fourth direction, the width of the second terminal row in the fourth direction is shorter than the width of the first terminal row in the fourth direction. According to embodiment 12, compared to the embodiment in which a flexible substrate is used to connect to the second substrate, the width of the terminal row can be reduced by using a substrate-to-substrate connector, thus contributing to miniaturization of the first substrate in the direction perpendicular to the first direction.

[0139] In embodiment 13, which is a specific example of embodiment 12, the width of the connector in the fourth direction is longer than the width of the first board-to-board connector in the fourth direction.

[0140] In embodiment 14, which is a specific example of embodiment 13, the thickness direction of the first substrate and the thickness direction of the second substrate are substantially the same direction. According to embodiment 14, the liquid spray head can be miniaturized in the first direction compared to an embodiment in which the thickness direction of the first substrate and the thickness direction of the second substrate are different from each other.

[0141] A liquid injection device according to embodiment 15, which is a preferred embodiment, comprises a liquid injection head according to any one embodiment from embodiment 1 to embodiment 14, and an external wiring member disposed outside the liquid injection head and connected to the connector of the liquid injection head. According to embodiment 15, compared to an embodiment in which the second substrate extends in a direction perpendicular to the first substrate, a liquid spraying device can be provided in which the liquid spraying head is miniaturized in the first direction. [Explanation of symbols]

[0142] 10...Liquid reservoir, 20...Control unit, 30...Transport mechanism, 40,40C...Moving mechanism, 41,41C...Support, 41a,41aC...Opening, 41b...Screw hole, 42...Transport belt, 50,50A,50B,50C,50D...Liquid injection head, 50C1,50C2...Protrusion, 51,51A,51C,51D...Wiring board, 52S1,52S1,52S2...Surface, 51c,51c1,51c1A,51c1C,51c2,51c2A,51c2C,51c3,51c3A,51c3C,51c4,51c4A,51c4C,51cA,51cC...Opening, 51d1,51d 1A, 51d1C…1st BtoB connector, 51d2, 51d2A, 51d2C…2nd BtoB connector, 51f1, 51f1A, 51f1C, 51f2, 51f2A, 51f2C, 51f3, 51f3A, 51f4, 51f4A, 51g1, 51g1C, 51g2, 51g2C, 51g3, 51g4…Terminal, 51h1, 51h4…Notch, 52, 52A, 52B, 52C…Intermediate board, 52b, 52bA, 52bB…Connector, 52d3, 52d3A, 52d3C…3rd BtoB connector, 52d4, 52d4A, 52d4C…4th BtoB connector 53, 53C…Flow channel structure, 53a…Flow channel member, 53b…First flow channel connection part, 53c…Second flow channel connection part, 53d, 53dC…Opening, 53e…Recess, 53i, 53k…Screw hole, 54, 54_1, 54_1A, 54_1C, 54_2, 54_2A, 54_2C, 54_3, 54_3A, 54_3C, 54_4, 54_4A, 54_4C…Head tip, 54a…Communication plate, 54b…Pressure chamber substrate, 54c…Nozzle plate, 54d…Vibration absorber, 54e…Diaphragm, 54f…Piezoelectric element, 54g…Protective substrate, 54h…Case, 54i_1, 54i_1C, 54i_2, 54i _2C,54i_3,54i_3C,54i_4,54i_4C…Wiring component, 54j…Drive circuit, 54k…Frame, 55,55C…Fixing plate, 55a,55aC…Opening, 58,58C…Cover, 58a…Opening, 58b,58c…Through hole, 59,Wiring component, 100,100A,100C…Liquid injection device, A,B…Element, C…Pressure chamber, C…Element, D…Drive signal, DM…Conveying direction, FN…Nozzle surface, IO…Inlet, L1…First row, L2…Second row, Lf1,Lf1A,Lf1C,Lf2,Lf2A,Lf2C,Lf3,Lf3A,Lf4,Lf4A,Lg1,Lg1C,Lg2, Lg2C, Lg3, Lg4, Lgx…Terminal array, M…Media, N…Nozzle, Na…Communication channel, R…Reservoir, R1, R2…Space, RE, REC…Rectangle, Ra…Supply channel, S…Control signal.

Claims

1. Multiple head tips that spray liquid in a first direction, A first substrate is a rigid substrate connected to a plurality of flexible substrates provided on each of the plurality of head chips, A second substrate is a rigid substrate provided on the side opposite to the plurality of head chips relative to the first substrate, and is provided with a connector for connecting to an external wiring member. Equipped with, The first substrate has a first substrate-to-substrate connector connected to the second substrate, and a second substrate-to-substrate connector connected to the second substrate. The second board has a third board-to-board connector connected to the first board and a fourth board-to-board connector connected to the first board. The first board-to-board connector is mated with the third board-to-board connector, thereby connecting the first board-to-board connector to the third board-to-board connector. The second board-to-board connector is mated with the fourth board-to-board connector, thereby connecting the second board-to-board connector to the fourth board-to-board connector. The connector is electrically connected to the third board-to-board connector and the fourth board-to-board connector. A liquid spray head characterized by the following features.

2. Viewed in the first direction, the second substrate is smaller than the first substrate. The liquid spray head according to feature 1.

3. Viewed in the first direction, the first board-to-board connector and the second board-to-board connector are located inside the smallest rectangle that encloses the plurality of head chips. A liquid spray head according to claim 1 or 2.

4. Viewed in the first direction, the second substrate overlaps with part or all of one or more of the multiple flexible substrates, A liquid spray head according to any one of claims 1 to 3.

5. The system includes a flow channel structure disposed between the plurality of head chips and the first substrate, which supplies liquid to the plurality of head chips. The flow channel structure has multiple openings through which each of the multiple flexible substrates is inserted. A liquid spray head according to any one of claims 1 to 4.

6. The aforementioned flow channel structure has a plurality of flow channel connection parts for connecting to an external flow channel member, The plurality of flow path connection portions include a first flow path connection portion and a second flow path connection portion that are arranged apart from each other in a direction perpendicular to the first direction, The first substrate is positioned between the first channel connection portion and the second channel connection portion in a direction perpendicular to the first direction. The liquid spray head according to feature 5.

7. Viewed in the first direction, the plurality of head chips include one head chip and the other head chip that are adjacent to each other via the first board-to-board connector, The first substrate has a first opening through which the flexible substrate of one head chip is inserted, a second opening through which the flexible substrate of the other head chip is inserted, a plurality of first terminals provided between the first substrate-to-substrate connector and the first opening, and a plurality of second terminals provided between the first substrate-to-substrate connector and the second opening. The flexible substrate of one of the head chips is connected to the plurality of first terminals, The flexible substrate of the other head chip is connected to the plurality of second terminals. A liquid spray head according to any one of claims 1 to 6.

8. Viewed in the first direction, the plurality of head chips include one head chip and the other head chip that are adjacent to each other via the first board-to-board connector, The first substrate has a first opening through which the flexible substrate of one head chip is inserted, a notch through which the flexible substrate of the other head chip is inserted, a plurality of first terminals provided between the first substrate-to-substrate connector and the first opening, and a plurality of second terminals provided between the first substrate-to-substrate connector and the notch. The flexible substrate of one of the head chips is connected to the plurality of first terminals, The flexible substrate of the other head chip is connected to the plurality of second terminals. A liquid spray head according to any one of claims 1 to 6.

9. The aforementioned plurality of head chips include a first head chip, a second head chip, a third head chip, and a fourth head chip. The first head chip has a first flexible substrate, The second head chip has a second flexible substrate, The third head chip has a third flexible substrate, The fourth head chip has a fourth flexible substrate, The first head chip, the second head chip, the third head chip, and the fourth head chip are arranged in this order along a second direction perpendicular to the first direction. The first head tip and the third head tip are positioned substantially identically with respect to a third direction that is perpendicular to both the first and second directions. The second head tip and the fourth head tip are positioned in substantially the same location with respect to the third direction. The first head chip and the second head chip are positioned offset in the third direction such that they partially overlap when viewed in the second direction. The first board-to-board connector is positioned between the first flexible board and the third flexible board. The second board-to-board connector is positioned between the second flexible board and the fourth flexible board. A liquid spray head according to any one of claims 1 to 8.

10. The aforementioned plurality of head chips include a first head chip, a second head chip, a third head chip, and a fourth head chip. The first head chip has a first flexible substrate, The second head chip has a second flexible substrate, The third head chip has a third flexible substrate, The fourth head chip has a fourth flexible substrate, The first head chip, the second head chip, the third head chip, and the fourth head chip are arranged in this order along a second direction perpendicular to the first direction. The first head tip and the third head tip are positioned substantially identically with respect to a third direction that is perpendicular to both the first and second directions. The second head tip and the fourth head tip are positioned in substantially the same location with respect to the third direction. The first head tip and the second head tip are positioned offset from each other in the third direction. The first head chip and the second head chip are positioned offset in the second direction such that they partially overlap when viewed in the third direction. The second head chip and the third head chip are positioned offset in the second direction such that they partially overlap when viewed in the third direction. The third head chip and the fourth head chip are positioned offset in the second direction such that they partially overlap when viewed in the third direction. The first board-to-board connector is positioned between the first flexible board and the third flexible board. The second board-to-board connector is positioned between the second flexible board and the fourth flexible board. A liquid spray head according to any one of claims 1 to 6.

11. Viewed in the first direction, the connector is positioned between the first board-to-board connector and the second board-to-board connector, or overlaps with the first board-to-board connector and the second board-to-board connector. A liquid spray head according to any one of claims 1 to 10.

12. The flexible substrate provided on one of the multiple head chips is connected to the first substrate and has a first terminal row composed of multiple third terminals arranged along a fourth direction perpendicular to the first direction. The first board-to-board connector has a second terminal row connected to the first board and composed of a plurality of fourth terminals arranged along the fourth direction, The width of the second terminal row in the fourth direction is shorter than the width of the first terminal row in the fourth direction. A liquid spray head according to any one of claims 1 to 11.

13. The width of the connector in the fourth direction is longer than the width of the first board-to-board connector in the fourth direction. The liquid spray head according to feature 12.

14. The thickness direction of the first substrate and the thickness direction of the second substrate are substantially the same direction. A liquid spray head according to any one of claims 1 to 13.

15. The number of the aforementioned connectors is less than the number of the first board-to-board connectors and the second board-to-board connectors, and less than the number of the third board-to-board connectors and the fourth board-to-board connectors. A liquid spray head according to any one of claims 1 to 14.

16. The number of connectors is 1. The liquid spray head according to feature 15.

17. The number of the first substrates is equal to the number of the second substrates. A liquid spray head according to any one of claims 1 to 16.

18. A liquid spray head according to any one of claims 1 to 17, The external wiring member is located outside the liquid spray head and is connected to the connector of the liquid spray head, A liquid injection device characterized by being equipped with the following features.

Images