Liquid ejection head and liquid ejection device

Abstract

The present application discloses a liquid ejection head and a liquid ejection device for miniaturizing a liquid ejection head. The liquid ejection head (10) includes a plurality of head chips (20) elongated in a first direction V and has an ejection surface (30) for ejecting liquid. In the liquid ejection head (10), inside a hypothetical parallelogram (120) having a first hypothetical side (121) and a second hypothetical side (122) along the first direction (V) and in contact with at least one of the plurality of head chips (20), and a third hypothetical side (123) and a fourth hypothetical side (124) along a second direction (U) intersecting the first direction (V) and in contact with at least one of the plurality of head chips (20), a plurality of head chips (20) are arranged. When observing the ejection surface (30) from the normal direction (Z) of the ejection surface (30), the ejection surface (30) does not overlap with the acute angle portion (131) of the hypothetical parallelogram (120).

Description

Technical Field

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

[0002] Conventionally, a liquid ejection device having a liquid ejection head that ejects a liquid such as ink, represented by an inkjet printer, has been known. For example, in Patent Document 1, a plurality of head chips having nozzle rows that are inclined with respect to the conveyance direction of a medium such as printing paper are disclosed. Such a liquid ejection head having a plurality of head chips is arranged along the width direction of the medium to form a line head.

[0003] When the area of the region on the ejection surface of the liquid ejection head where no head chip is arranged increases, the liquid ejection head becomes large. In addition, when a plurality of such liquid ejection heads are arranged to form a line head, the problem of the line head becoming large occurs.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-55476 Summary of the Invention

[0005] One aspect of the liquid ejection head of the present disclosure includes a plurality of head chips that are long and narrow in a first direction, and has a liquid ejection head having an ejection surface for ejecting a liquid. In the liquid ejection head, the plurality of head chips are arranged and provided inside a hypothetical parallelogram having a first hypothetical side and a second hypothetical side that are along the first direction and are in contact with at least one of the plurality of head chips, and a third hypothetical side and a fourth hypothetical side that are along a second direction intersecting the first direction and are in contact with at least one of the plurality of head chips. When the ejection surface is observed from the normal direction of the ejection surface, the ejection surface does not overlap with the acute angle portion of the hypothetical parallelogram.

[0006] One aspect of the liquid ejection device of the present disclosure includes the above-described liquid ejection head and a liquid storage unit that stores the liquid supplied to the liquid ejection head. Brief Description of the Drawings

[0007] Figure 1 It is a schematic diagram showing an outline of a configuration example of the liquid ejection device according to the first embodiment.

[0008] Figure 2 It is a perspective view of the liquid ejection head.

[0009] Figure 3 It is an exploded perspective view of the liquid ejection head.

[0010] Figure 4 It is a side view of the liquid ejection head.

[0011] Figure 5 A perspective view showing the ejection surface of a liquid ejection head.

[0012] Figure 6 A bottom view showing the ejection surface of a liquid ejection head and a view showing a plurality of head chip groups.

[0013] Figure 7 A bottom view showing the ejection surface of a liquid ejection head and a view showing a hypothetical parallelogram corresponding to the arrangement of a plurality of head chips.

[0014] Figure 8 A bottom view showing a part of the ejection surface and a view showing an acute angle portion of a hypothetical parallelogram.

[0015] Figure 9 A bottom view showing a part of the ejection surface and a view showing an obtuse angle portion of a hypothetical parallelogram.

[0016] Figure 10 A bottom view showing the ejection surfaces of a plurality of liquid ejection heads arranged in the X-axis direction.

[0017] Figure 11 A top view showing the upper surface of a liquid ejection head.

[0018] Figure 12 A perspective view showing a wiring substrate and a relay substrate of a liquid ejection head.

[0019] Figure 13 A schematic view showing the positional relationship between a hypothetical parallelogram corresponding to the outer shape of the upper surface and an electrical connection portion.

[0020] Figure 14 A bottom view showing the ejection surface of a liquid ejection head and a view showing a hypothetical parallelogram corresponding to the outer shape of the liquid ejection head when observed in the normal direction of the ejection surface.

[0021] Figure 15 A bottom view showing a part of the ejection surface and a view showing an acute angle portion of a hypothetical parallelogram.

[0022] Figure 16 A schematic view showing a liquid ejection device according to a second embodiment.

[0023] Figure 17 A view showing a liquid ejection device as observed in the central axis direction of a supply reel.

[0024] Figure 18 A bottom view showing a plurality of line heads separately arranged in the conveyance direction of a medium.

[0025] Figure 19 An upward view of the ejection surface of the liquid ejection head according to the first modification example.

[0026] Figure 20 An upward view of the ejection surface of the liquid ejection head according to the second modification example.

[0027] Figure 21 An upward view of the ejection surface of the liquid ejection head according to the third modification example.

[0028] Figure 22 A schematic diagram of the liquid ejection device according to the third embodiment. Detailed implementation mode

[0029] Hereinafter, modes for implementing the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and scales of the respective parts are appropriately different from the actual situation. In addition, although various technically preferable limitations are added to the following embodiments because they are preferable specific examples of the present invention, the scope of the present invention is not limited to these modes as long as there is no description specifically limiting the present invention in the following description.

[0030] In the following description, three mutually intersecting directions will be described as the X-axis direction, the Y-axis direction, and the Z-axis direction. The X-axis direction includes the X1 direction and the X2 direction, which are opposite directions to each other. The X-axis direction is an example of the third direction. The Y-axis direction includes the Y1 direction and the Y2 direction, which are opposite directions to each other. The Y-axis direction is an example of the fourth direction. The Z-axis direction includes the Z1 direction and the Z2 direction, which are opposite directions to each other. The Z1 direction is the downward direction, and the Z2 direction is the upward direction. In addition, in this specification, "up" and "down" are used. "Up" and "down" correspond to "up" and "down" in the normal use state of the liquid ejection device 1A.

[0031] The Z-axis direction is the direction along the up-and-down direction. Although the X-axis direction, the Y-axis direction, and the Z-axis direction are typically orthogonal to each other, this is not limited thereto. For example, they may intersect at an angle within the range of 80° or more and 100° or less. The Z-axis direction may also not be the direction along the up-and-down direction.

[0032] Figure 1This is a schematic diagram showing a configuration example of the liquid ejection device 1A according to the first embodiment. The liquid ejection device 1A is an inkjet printing device that ejects ink, which is an example of "liquid", as droplets onto the medium PP. The liquid ejection device 1A of the present embodiment is a so-called line printer in which a plurality of nozzles for ejecting ink are distributed over the entire width direction of the medium PP. The medium PP is typically printing paper. In addition, the medium PP is not limited to printing paper, and can be, for example, a printing object made of any material such as a resin film or cloth.

[0033] As Figure 1 shown, the liquid ejection device 1A includes a liquid container 2 for storing ink. As a specific form of the liquid container 2, for example, a cartridge that is detachable from the liquid ejection device 1A, a bag-shaped ink bag formed of a flexible film, and an ink tank that can replenish ink are listed. In addition, the type of ink stored in the liquid container 2 is arbitrary. The liquid container 2 is an example of a liquid storage unit.

[0034] Although not shown in the figure, the liquid container 2 includes a first liquid container and a second liquid container. The first ink is stored in the first liquid container. The second ink, which is different in type from the first ink, is stored in the second liquid container. For example, the first ink and the second ink are inks of different colors. In addition, the first ink and the second ink may be inks of the same type.

[0035] The liquid ejection device 1A has a control unit 3, a medium conveyance mechanism 4, a circulation mechanism 5, and a plurality of liquid ejection heads 10. The control unit 3 controls the operation of each element of the liquid ejection device 1A. The control unit 3 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage circuit such as a semiconductor memory. Various programs and various data are stored in this storage circuit. The processing circuit realizes various controls by executing this program and appropriately using this data.

[0036] The medium conveyance mechanism 4 is controlled by the control unit 3 to convey the medium PP in the conveyance direction DM. The conveyance direction DM is, for example, the Y1 direction. The conveyance direction DM is not limited to the Y1 direction, and can be the Y2 direction or other directions. The medium conveyance mechanism 4 includes a conveyance roller that is long and narrow in the X-axis direction, and a motor that rotates the conveyance roller. In addition, the medium conveyance mechanism 4 is not limited to a structure using a conveyance roller, and can be, for example, a structure using a reel or a seamless belt that conveys the medium PP in a state where the medium PP is adsorbed on the outer peripheral surface by electrostatic force or the like.

[0037] The liquid ejection head 10 is controlled by the control unit 3, and ink supplied from the liquid container 2 via the circulation mechanism 5 is ejected from a plurality of nozzles toward the medium PP, respectively. The plurality of liquid ejection heads 10 are arranged along the X-axis direction to constitute a line head 50.

[0038] The ink stored in the liquid container 2 is supplied to the liquid ejection head 10 via the circulation mechanism 5. The circulation mechanism 5 supplies ink to the liquid ejection head 10 and recovers the ink discharged from the liquid ejection head 10. The circulation mechanism 5 supplies the recovered ink to the liquid ejection head 10 again. The circulation mechanism 5 includes a flow path for supplying ink to the liquid ejection head 10, a flow path for recovering the ink discharged from the liquid ejection head 10, a sub-tank for storing the recovered ink, a pump for transferring the ink, and the like.

[0039] Next, the liquid ejection head 10 will be described with reference to Figures 2 to 6 FIGs. Figure 2 FIG. 12 is a perspective view of the liquid ejection head 10. Figure 3 FIG. 13 is an exploded perspective view of the liquid ejection head 10. Figure 4 FIG. 14 is a side view of the liquid ejection head 10. Figure 5 FIG. 15 is a perspective view showing the ejection surface 30 of the liquid ejection head 10. Figure 6 FIG. 16 is a bottom view showing the ejection surface 30 of the liquid ejection head 10. In Figure 5 FIG. 17, the liquid ejection head 10 is shown from obliquely below. As Figure 2 shown in FIG. 18, the liquid ejection head 10 includes a flow path structure body 11 and a bracket 13. As Figure 3 shown in FIG. 19, the liquid ejection head 10 has a plurality of head chips 20.

[0040] In Figure 2 and Figure 3 shown, a flow path through which ink flows is formed inside the flow path structure body 11. This flow path communicates with the circulation mechanism 5 and the plurality of head chips 20. Inside the liquid ejection head 10, a flow path for supplying ink to the plurality of head chips 20 and a flow path for recovering the ink discharged from the head chips 20 are formed. The flow path structure body 11 includes a plurality of flow path substrates as plate-like members.

[0041] On this flow path substrate, at least one of a recess or an opening for forming a flow path and a tube protruding from the flow path substrate in the Z-axis direction is formed. The uppermost flow path substrate in the Z2 direction among the plurality of flow path substrates of the flow path structure body 11, that is, the top plate 17, has an upper surface 170 as a surface facing the side opposite to the ejection surface 30. A flow path tube 14 is provided on the top plate 17. The flow path tube 14 protrudes from the upper surface 170 in the Z2 direction and is connected to a flow path outside the liquid ejection head 10.

[0042] As Figure 3 and Figure 4 shown, the liquid ejection head 10 includes a wiring substrate 12. The wiring substrate 12 is a mounting member for electrically connecting a plurality of head chips 20 to a relay substrate 16 described later. The wiring substrate 12 is, for example, a rigid wiring substrate. The wiring substrate 12 is arranged in the Z2 direction with respect to the bracket 13. In addition, in the present embodiment, the wiring substrate 12 is arranged between a plurality of flow channel substrates constituting the flow channel structure body 11 laminated along the Z-axis direction.

[0043] A connector 12b is provided on the upper surface 12a which is the surface of the wiring substrate 12 facing the Z2 direction. The connector 12b is a connecting member for connecting to the relay substrate 16. The wiring substrate 12 is connected to a wiring member 28 which is electrically connected to a driving element of the head chip 20. The wiring member 28 is, for example, an FPC (Flexible Printed Circuits) or a COF (Chip On Film).

[0044] The relay substrate 16 extends in the Z2 direction from the connector 12b. The relay substrate 16 passes through a part of the flow channel structure body 11 in the Z2 direction and projects upward. The thickness direction of the relay substrate 16 is along the Y-axis direction. A plurality of connectors 18 are provided at the end portion of the relay substrate 16 in the Z2 direction. The connectors 18 are arranged on both sides in the Y-axis direction. Each connector 18 internally has a plurality of connection terminals (not shown). The connection terminal is a terminal for electrically connecting to the outside of the liquid ejection head 10. The plurality of connection terminals are arranged in the X-axis direction.

[0045] The relay substrate 16 and the connector 18 are included in an electrical connection portion 110 for electrically connecting to the outside of the liquid ejection head 10. A wiring for electrically connecting the connector 18 to the wiring substrate 12 is formed on the relay substrate 16. The relay substrate 16 is, for example, a rigid wiring substrate. The arrangement of the connector 18 when observing the liquid ejection head 10 along the Z-axis direction will be described later.

[0046] As Figure 4 shown, covers 19A and 19B are provided on both sides of the relay substrate 16 in the Y-axis direction. The cover 19A covers the surface of the relay substrate 16 in the Y1 direction. The cover 19B covers the surface of the relay substrate 16 in the Y2 direction. The covers 19A and 19B may also include portions covering the end faces of the relay substrate 16 in the X-axis direction.

[0047] The bracket 13 is located below the wiring substrate 12. The bracket 13 has a predetermined thickness in the Z-axis direction. The bracket 13 holds the fixing plate 15 and the plurality of head chips 20. An opening or recess for accommodating the head chips 20 is formed in the bracket 13. The bracket 13 may also include a plurality of plate-like members. The bracket 13 is formed of, for example, stainless steel. The material of the bracket 13 is not limited to stainless steel and may be other materials such as metal or resin.

[0048] Flange portions 41, 42 extending to both sides in the Y-axis direction are formed on the bracket 13. The flange portions 41, 42 extend to opposite sides. The flange portion 41 extends in the Y1 direction, and the flange portion 42 extends in the Y2 direction. The flange portions 41, 42 will be described below.

[0049] Figure 5 and Figure 6 The fixing plate 15 shown is a plate-like member for fixing the plurality of head chips 20 to the bracket 13. The fixing plate 15 constitutes the bottom surface of the liquid ejection head 10. The lower surface 15a of the fixing plate 15 is a surface opposed to the medium PP and constitutes a part of the ejection surface 30. An opening for exposing the nozzle plate 23 of the head chip 20 is formed in the fixing plate 15. As Figure 6 shown, a plurality of nozzles N are formed on the nozzle plate 23. The arrangement of the plurality of head chips 20 and the shape of the ejection surface 30 will be described below.

[0050] The head chip 20 includes a mechanism (not shown) for ejecting ink from the nozzle. The head chip 20 includes a flow path through which ink flows, a pressure generation chamber communicating with the nozzle, a diaphragm for changing the pressure of the ink in the pressure generation chamber, a piezoelectric element for vibrating the diaphragm, upper and lower electrodes for driving the piezoelectric element, and the aforementioned wiring component 80 electrically connected to the upper and lower electrodes. The outer shape of the head chip 20 is rectangular when viewed in the normal direction of the ejection surface 30. The rectangular shape includes a substantially rectangular shape. The head chip 20 may be a substantially rectangular shape with at least a part of the corners of the rectangle cut off, or may be a substantially rectangular shape with a notch or protrusion formed on at least one side of the rectangle.

[0051] When the liquid ejection head 10 is viewed in the Z2 direction, which is the normal direction of the ejection surface 30, the lower surface 15a of the fixing plate 15, the nozzle plate 23, and the flange portions 41, 42 can be seen. The ejection surface 30 includes the fixing plate 15 and the nozzle plate 23. As Figure 4 shown, the ejection surface 30 and the flange portions 41, 42 are arranged at different positions in the Z-axis direction.

[0052] Next, refer to Figure 6, the configuration of the plurality of head chips 20 when observing the ejection surface 30 in the Z-axis direction will be described. In Figure 6 , the outer shape of the head chip 20 is represented by a dashed line, and the nozzle row Ln is schematically shown in the form of a dotted line. As Figure 6 shown, when observing the ejection surface 30 in the Z-axis direction, the long side direction of the plurality of head chips 20 is the V direction that is inclined with respect to the X-axis direction and the Y-axis direction. The V direction is an example of the first direction.

[0053] The head chip 20 has a nozzle plate 23 in which a plurality of nozzles N are formed. The nozzle N is a through hole that penetrates in the plate thickness direction of the nozzle plate 23. The plate thickness direction of the nozzle plate 23 is along the Z-axis direction. The plurality of nozzles N are arranged along the long side direction of the head chip 20, thereby constituting the nozzle row Ln. The plurality of nozzles N included in the same nozzle row Ln are arranged on the same straight line. The nozzle row Ln extends along the V direction.

[0054] "The long side direction of the head chip 20 is the V direction" may mean that the outer shape of the head chip 20 is long in the V direction, and in addition, it also includes the case where the nozzle row Ln of the head chip 20 extends along the V direction. Further, "the long side direction of the head chip 20 is the V direction" means that when the outer shape of the head chip 20 observed in the normal direction of the ejection surface 30 is a rectangular shape, the long side of the rectangle extends along the V direction.

[0055] The plurality of head chips 20 constitute a plurality of chip groups 25A and 25B. The plurality of chip groups 25A and 25B are arranged in this order in the Y1 direction. In addition, in this specification, when the head chips 21A to 21C and 22A to 22C described later are not distinguished, they are described as the head chip 20.

[0056] The chip group 25A has head chips 21A, 21B, and 21C as the plurality of head chips 20. The head chips 21A, 21B, and 21C are arranged in the X2 direction in this order. When observing from the Y-axis direction, a part of the nozzle rows Ln of the adjacent head chips 20 among the head chips 20 of the chip group 25A overlap each other when observed from the Y-axis direction. Therefore, the printing width in the X-axis direction can be increased.

[0057] In addition, the head chips 21A to 21C of the chip group 25A mostly overlap each other when observed from the X-axis direction. Although in this embodiment, the head chip 21B is slightly offset in the Y2 direction with respect to the adjacent head chip 21A, and the head chip 21C is slightly offset in the Y2 direction with respect to the adjacent head chip 21B, the head chips 21A to 21C of the chip group 25A may not be offset in the Y-axis direction from each other.

[0058] The chipset 25B has head chips 22A, 22B, and 22C as multiple head chips 20. The positional relationship of the head chips 22A, 22B, and 22C included in the chipset 25B is the same as the positional relationship of the head chips 21A, 21B, and 21C included in the chipset 25A.

[0059] The chipset 25A and the chipset 25B almost overlap when viewed from the Y-axis direction. That the chipset 25A and the chipset 25B almost overlap when viewed from the Y-axis direction means that when viewed from the Y-axis direction, the head chip 21A arranged closest to the X1 direction in the chipset 25A and the head chip 22A arranged closest to the X1 direction in the chipset 25B almost overlap, and the head chip 21C arranged closest to the X2 direction in the chipset 25A and the head chip 22C arranged closest to the X2 direction in the chipset 25B almost overlap.

[0060] In addition, that two head chips 20 almost overlap when viewed from the Y-axis direction means that, for example, the nozzle N located closest to the X1 direction of the head chip 21A and the nozzle N located closest to the X1 direction of the head chip 22A are in the same position with respect to the X-axis direction, or the distance between adjacent nozzles N of the head chip 20 in the X-axis direction is less than or equal to half. With such a structure, high image quality can be achieved by making the types of liquids ejected from the chipset 25A the same as those ejected from the chipset 25B, and multi-colorization can be achieved by changing the types of liquids.

[0061] In addition, since a part of the chipset 25A and the chipset 25B overlap each other when viewed from the X direction, the ejection surface 30 can be miniaturized in the Y-axis direction.

[0062] Next, with reference to Figure 7 the positional relationship between the multiple head chips 20 and the imaginary parallelogram 120 when the ejection surface 30 is viewed from the Z-axis direction will be described. In Figure 7 it, the outer shape of the head chip 20 is represented by a dotted line, and the imaginary parallelogram 120 is represented by a double-dotted line. The imaginary parallelogram 120 can be set according to the arrangement of the multiple head chips 20. The imaginary parallelogram 120 is used to explain the shape of the ejection surface 30. After the imaginary parallelogram 120 has been explained, the shape of the ejection surface 30 will be explained.

[0063] The imaginary parallelogram 120 has imaginary sides 121 to 124. The imaginary side 121 is an example of the first imaginary side, and the imaginary side 122 is an example of the second imaginary side. The imaginary side 123 is an example of the third imaginary side, and the imaginary side 124 is an example of the fourth imaginary side. The imaginary sides 121 and 122 are separated from each other in the X-axis direction and along the V direction. The imaginary sides 123 and 124 are separated from each other in the Y-axis direction and along the U direction. When observing the ejection surface 30 from the Z-axis direction, the U direction is inclined with respect to the X-axis direction, the Y-axis direction, and the V direction. When observing the ejection surface 30 from the Z-axis direction, the U direction is inclined with respect to the X-axis direction by, for example, 5°. The U direction is an example of the second direction. In addition, when observing the ejection surface 30 from the Z-axis direction, the U direction may not be inclined with respect to the X-axis direction. In other words, the U direction may be the X-axis direction.

[0064] The imaginary parallelogram 120 has acute-angle portions 131 and 132 and obtuse-angle portions 133 and 134. The imaginary sides 121 and 123 form the acute-angle portion 131. The acute-angle portion 131 is an example of the first acute-angle portion. The imaginary sides 122 and 124 form the acute-angle portion 132. The imaginary sides 122 and 123 form the obtuse-angle portion 133. The imaginary sides 122 and 124 form the obtuse-angle portion 134. When observing from the Z-axis direction, all the head chips 20 are located inside the imaginary parallelogram 120.

[0065] At least one head chip 20 is inscribed in the imaginary side 121. The head chip 20 being inscribed in the imaginary sides 121 to 124 means a case where the head chip 20 disposed inside the imaginary parallelogram 120 is in contact with the imaginary sides 121 to 124. In the present embodiment, only one head chip 20 is inscribed with respect to the imaginary side 121. Only the head chip 21A is inscribed with respect to the imaginary side 121.

[0066] At least one head chip 20 is inscribed with respect to the imaginary side 122. In the present embodiment, only one head chip 20 is inscribed with respect to the imaginary side 122. Only the head chip 22C is inscribed with respect to the imaginary side 122. The head chip 22C inscribed in the imaginary side 122 is different from the head chip 21A inscribed in the imaginary side 121.

[0067] At least one head chip 20 is inscribed with respect to the imaginary side 123. In the present embodiment, a plurality of head chips 20 are inscribed with respect to the imaginary side 123. For example, the three head chips 22A to 22C included in the chip group 25B are inscribed with respect to the imaginary side 123.

[0068] At least one head chip 20 is inscribed with respect to the imaginary side 124. In the present embodiment, a plurality of head chips 20 are inscribed with respect to the imaginary side 124. For example, three head chips 21A to 21C included in the chip group 25A are inscribed with respect to the imaginary side 124.

[0069] In this way, in the present embodiment, when viewed from the Z-axis direction, all the head chips 20 of the liquid ejection head 10 are inscribed in one of the imaginary sides 121 to 124 of the imaginary parallelogram 120.

[0070] Figure 8 It is a bottom view showing a part of the ejection surface 30 and is a view showing the acute angle portion 131 of the imaginary parallelogram 120. In Figure 8 it, the outer shape of the head chip 20 is indicated by a dotted line, the imaginary parallelogram 120 is indicated by a double-dotted line, and the region of the acute angle portion 131 is indicated by a dotted line. As Figure 8 shown, the plurality of head chips 20 include the head chip 21A inscribed in the imaginary side 121 at the closest position to the acute angle portion 131 and the head chip 22A inscribed in the imaginary side 123 at the closest position to the acute angle portion 131. The head chip 21A is an example of the first head chip, and the head chip 22A is an example of the second head chip. The head chip 21A inscribed in the imaginary side 121 at the closest position to the acute angle portion 131 is different from the head chip 22A inscribed in the imaginary side 123 at the closest position to the acute angle portion 131. The head chip 21A inscribed in the imaginary side 121 is not inscribed in the imaginary side 123. The head chip 22A inscribed in the imaginary side 123 is not inscribed in the imaginary side 121.

[0071] The plurality of head chips 20 include the head chip 21C inscribed in the imaginary side 124 at the closest position to the acute angle portion 132 and the head chip 22C inscribed in the imaginary side 122 at the closest position to the acute angle portion 132. The head chip 21C inscribed in the imaginary side 124 at the closest position to the acute angle portion 132 is different from the head chip 22C inscribed in the imaginary side 122 at the closest position to the acute angle portion 132. The head chip 21C inscribed in the imaginary side 124 is not inscribed in the imaginary side 122. The head chip 22C inscribed in the imaginary side 122 is not inscribed in the imaginary side 124.

[0072] The plurality of head chips 20 include the head chip 21A inscribed in both the imaginary sides 121 and 124. The plurality of head chips 20 include the head chip 22C inscribed in both the imaginary sides 122 and 123.

[0073] Next, refer to Figure 7, the outer shape of the ejection surface 30 as viewed from the Z-axis direction will be described. The ejection surface 30 has edge portions 31 to 38. The edge portions 31 to 38 form the outer shape of the ejection surface 30. The edge portion 31 extends along the imaginary side 121 of the imaginary parallelogram 120. The edge portion 32 extends along the imaginary side 122. The edge portions 31 and 32 extend linearly along the V direction.

[0074] The edge portions 33 and 34 respectively form the two end portions of the ejection surface 30 in the Y-axis direction. The edge portions 33 and 34 are separated from each other in the Y-axis direction and extend linearly along the X-axis direction. The edge portion 33 forms the end portion of the ejection surface 30 in the Y1 direction, and the edge portion 34 forms the end portion of the ejection surface 30 in the Y2 direction.

[0075] The edge portion 35 forms the end portion of the ejection surface 30 in the X1 direction. The edge portion 35 connects the edge portion 31 and the edge portion 33 in the Y-axis direction. The edge portion 35 extends linearly along the Y-axis direction between the acute angle portion 131 of the imaginary parallelogram 120 and the head chip 20 closest to the acute angle portion 131 in the X-axis direction. The edge portion 35 intersects the imaginary sides 121 and 123.

[0076] When viewed from the X direction, the edge portion 35 overlaps at least one of the plurality of head chips 20 that do not contact the imaginary side 123. When viewed from the X direction, the edge portion 35 overlaps at least one of the plurality of head chips 20 that contact the imaginary side 124. When viewed from the X direction, the edge portion 35 overlaps with the end portion 20a of the head chip 21A. The head chip 21A contacts the imaginary side 124 and does not contact the imaginary side 123. The end portion 20a is the end portion closer to the edge portion 33 among the two end portions 20a and 20b in the long side direction of the head chip 20.

[0077] The edge portion 36 forms the end portion of the ejection surface 30 in the X2 direction. The edge portion 36 connects the edge portion 32 and the edge portion 34 in the Y-axis direction. The edge portion 36 extends linearly along the Y-axis direction between the acute angle portion 132 of the imaginary parallelogram 120 and the head chip 20 closest to the acute angle portion 132 in the X-axis direction. The edge portion 36 intersects the imaginary sides 122 and 124.

[0078] When viewed from the X direction, the edge portion 36 overlaps at least one of the plurality of head chips 20 that do not contact the imaginary side 124. When viewed from the X direction, the edge portion 36 overlaps at least one of the plurality of head chips 20 that contact the imaginary side 123. When viewed from the X direction, the edge portion 36 overlaps with the end portion 20b of the head chip 22C. The head chip 22C contacts the imaginary side 123 and does not contact the imaginary side 124. The end portion 20b is the end portion closer to the edge portion 34 among the two end portions 20a and 20b in the long side direction of the head chip 20.

[0079] The edge portion 37 is opposed to the edge portion 35 in the X-axis direction and extends in a straight line along the Y-axis direction. The edge portion 37 connects the edge portion 32 and the edge portion 33 in the Y-axis direction. The edge portion 37 is disposed outside the obtuse angle portion 133 in the X-axis direction. The edge portion 37 is located outside the imaginary parallelogram 120 in the X-axis direction so as not to overlap the imaginary parallelogram 120 when viewed from the Z-axis direction.

[0080] The edge portion 38 is opposed to the edge portion 36 in the X-axis direction and extends in a straight line along the Y-axis direction. The edge portion 38 connects the edge portion 31 and the edge portion 34 in the Y-axis direction. The edge portion 38 is disposed outside the obtuse angle portion 133 in the X-axis direction. The edge portion 38 is located outside the imaginary parallelogram 120 in the X-axis direction so as not to overlap the imaginary parallelogram 120 when viewed from the Z-axis direction.

[0081] Next, with reference to Figure 8 the positional relationship between the edge portions 35 and 36 and the acute angle portions 131 and 132 of the imaginary parallelogram 120 will be described. As Figure 8 shown, when viewed from the Z-axis direction, the ejection surface 30 does not overlap with the acute angle portion 131 of the imaginary parallelogram 120. The edge portion 35 exists at a position closer to the center of the imaginary parallelogram 120 than the acute angle portion 131 in the X-axis direction. The center of the imaginary parallelogram 120 is set as the intersection point of the diagonals of the imaginary parallelogram 120. The edge portion 35 is not located outside compared to the acute angle portion 131 in the X-axis direction. The head chip 22A closest to the acute angle portion 131 does not exist within the range of the acute angle portion 131.

[0082] For example Figure 8 as shown by the dotted line, the range of the acute angle portion 131 can be set within a predetermined length L11 starting from the vertex 131a of the acute angle portion 131. This predetermined length L11 can be, for example, 80% of the distance L12 from the vertex 131a to the head chip 22A closest to the vertex 131a. This predetermined length L11 can also be, for example, 50% or more and 90% or less of the distance L12.

[0083] Similarly, the ejection surface 30 does not overlap with the acute-angle portion 132. The edge portion 36 is located in the X-axis direction at a position closer to the center of the imaginary parallelogram 120 than the acute-angle portion 132. The head chip 21C closest to the acute-angle portion 132 does not exist within the range of the acute-angle portion 132.

[0084] Next, with reference to Figure 9 the positional relationship between the edge portions 37 and 38 and the obtuse-angle portions 133 and 134 of the imaginary parallelogram 120 will be described. Figure 9 It is a bottom view showing a part of the ejection surface 30 and is a view showing the obtuse-angle portion 133 of the imaginary parallelogram 120. In Figure 9 it, the outer shape of the head chip 20 is represented by a dashed line, the imaginary parallelogram 120 is represented by a double-dashed line, and the area of the obtuse-angle portion 133 is represented by a dotted line. As Figure 9 shown, the ejection surface 30 overlaps with the entire area of the obtuse-angle portion 133 of the imaginary parallelogram 120. The edge portion 37 is located outside the obtuse-angle portion 133 in the X-axis direction. The edge portion 33 is located outside the obtuse-angle portion 133 in the Y-axis direction. The ejection surface 30 extends to the outside of the obtuse-angle portion 133.

[0085] For example Figure 9 as shown by the dotted line in, the range of the obtuse-angle portion 133 can be set within a predetermined length L21 starting from the vertex 133a of the obtuse-angle portion 133. The case where the ejection surface 30 exists within the entire range of the obtuse-angle portion 133 is regarded as the ejection surface 30 overlapping with the entire area of the obtuse-angle portion 133. The predetermined length L21 representing the range of the obtuse-angle portion 133 can also be, for example, the same length as the width W20 of the head chip 20. This predetermined length L21 can also be 70% or more and 120% or less of the width W20 of the head chip 20. The predetermined length L21 representing the range of the obtuse-angle portion 133 can also be the same length as L11 representing the range of the acute-angle portion 131.

[0086] Similarly, the ejection surface 30 overlaps with the entire area of the obtuse-angle portion 134. The ejection surface 30 extends to the outside of the obtuse-angle portion 134, and the edge portion 38 is located outside the obtuse-angle portion 134 in the X-axis direction. The edge portion 34 is located outside the obtuse-angle portion 134 in the Y-axis direction. The predetermined length representing the range of the obtuse-angle portion 134 is the same as the predetermined length L21 representing the range of the obtuse-angle portion 133. The ejection surface 30 overlaps with the entire areas of both the obtuse-angle portions 133 and 134 of the imaginary parallelogram 120.

[0087] In such a liquid ejection head 10, the acute-angle portions 131 and 132 of the imaginary parallelogram 120 do not overlap with the ejection surface 30. The width W1 of the ejection surface 30 in the X-axis direction is shorter than the width W2 of the imaginary parallelogram 120 in the X-axis direction. The width W1 is the distance between the edge portion 35 and the edge portion 36 in the X-axis direction. The width W2 is the distance between the acute-angle portions 131 and 132 of the imaginary parallelogram 120 in the X-axis direction.

[0088] For example, in the case where an ejection surface having the outer shape of an imaginary parallelogram is set, the outer shape of the ejection surface becomes larger in the X-axis direction. According to the liquid ejection head 10, since the ejection surface does not overlap with the acute-angle portions 131 and 132 of the imaginary parallelogram 120, the area where the head chip 20 is not arranged is reduced. Since such a plurality of liquid ejection heads 10 are arranged in the X-axis direction to form the line head 50, the length of the line head 50 in the long side direction is shortened. As a result, miniaturization of the liquid ejection device 1A can be achieved.

[0089] Next, with reference to Figures 7 to 9 , the length L35 of the edge portion 35 and the length L37 of the edge portion 37 will be described. The length L37 of the edge portion 37 is shorter than the length L35 of the edge portion 35. The length L35 of the edge portion 35 is the distance from the end portion 35a in the Y-axis direction to the end portion 35b. The end portion 35a is the intersection of the edge portion 33 and the edge portion 35. The end portion 35b is the intersection of the edge portion 35 and the edge portion 31. When viewed from the Z-axis direction, the edge portion 35 is arranged at the same position as the edge portion 155 forming the outer shape of the bracket 13.

[0090] The length L37 of the edge portion 37 is the distance from the end portion 37a in the Y-axis direction to the end portion 37b. The end portion 37a is the intersection of the edge portion 33 and the edge portion 37. The end portion 37b is the intersection of the edge portion 37 and the edge portion 32. The end portions 35a and 37a are located at the same position in the Y-axis direction. The end portion 35b is located at a position farther from the edge portion 33 than the end portion 37b in the Y-axis direction. As shown in Figure 5 , when viewed from the Z-axis direction, the edge portion 37 is located closer to the inside than the edge portion 157 forming the outer shape of the bracket 13.

[0091] Figure 10 FIG. is a bottom view showing the ejection surfaces 30 of a plurality of liquid ejection heads 10 arranged in the X-axis direction. As shown in Figure 10As shown, in the adjacent liquid ejection heads 10, the width W11 of the gap between the edge portion 37 of one liquid ejection head 10 and the edge portion 35 of the other liquid ejection head 10 is wider than the width W12 of the gap between the brackets 13. In other words, in the liquid ejection heads 10 adjacent in the X-axis direction, the width W11 between the ejection surfaces 30 is wider than the width W12 between the brackets 13.

[0092] As Figure 5 shown, the wall surface 13a of the specified edge portion 37 is arranged closer to the inner side in the X-axis direction than the wall surface 13b of the edge portion 157 of the specified bracket 13. The wall surface 13c of the specified edge portion 32 is formed to the inner side in the X-axis direction compared to the wall surface 13b. The end portion 37b, which is the intersection of the edge portion 32 and the edge portion 37, is located in the X1 direction of the wall surface 13b.

[0093] According to such a liquid ejection head 10, the wall surface 13a is located closer to the inner side than the outer shape of the bracket 13, so that the width W11 between the ejection surfaces 30 in the Y-axis direction can be ensured to be wider. As a result, the situation where ink is drawn out due to capillary action near the ejection surface 30 in the Z-axis direction is reduced.

[0094] Similarly, in the present embodiment, the length of the edge portion 38 is shorter than the length of the edge portion 36. Therefore, in the adjacent liquid ejection heads 10, the width of the gap between the edge portion 36 of one liquid ejection head 10 and the edge portion 38 of the other liquid ejection head 10 is wider than the width W12 of the gap between the brackets 13.

[0095] Next, with reference to Figure 11 the upper surface 170 of the liquid ejection head 10 will be described. Figure 11 is a plan view showing the outer shape of the upper surface 170 of the liquid ejection head 10. In Figure 11 , the outer shape of the head chip 20 is indicated by a dashed line, the imaginary parallelogram 140 is indicated by a double-dashed line, and the region of the acute angle portion 145 is indicated by a dotted line. In Figure 11 , the electrical connection portion 110 is schematically shown as a rectangular frame. As will be described later in Figure 13 , the electrical connection portion 110 has a substantially rectangular shape when viewed from above. Figure 12 is a perspective view showing the wiring substrate 12 and the relay substrate 16. The liquid ejection head 10 includes an upper surface 170 facing the opposite side to the ejection surface 30 in the Z-axis direction, and an electrical connection portion 110 arranged so as to overlap with the end portion 170a of the upper surface 170.

[0096] When observing the upper surface 170 from the Z-axis direction, the electrical connection portion 110 is disposed at the end portion 170a in the Y-axis direction of the upper surface 170. The end portion 170a is the end portion in the Y2 direction. The electrical connection portion 110 may also include the aforementioned connector 12b, relay substrate 16, and connector 18. The electrical connection portion 110 may also include covers 19A and 19B.

[0097] The electrical connection portion 110 has a rectangular shape when observed from the Z-axis direction. The electrical connection portion 110 has an elongated rectangular shape along the X-axis direction. Having an elongated rectangular shape along the X-axis direction includes a shape in which, when observed from the Z-axis direction, the length along the X-axis direction is longer than the length along the Y-axis direction. The rectangular shape includes a substantially rectangular shape. The substantially rectangular electrical connection portion 110 includes a portion extending in the X-axis direction or a portion extending in the Y-axis direction when observed from the Z-axis direction.

[0098] Next, with reference to Figure 11 the outer shape of the upper surface 170 will be described. The upper surface 170 has edge portions 171 to 178. As described above, the upper surface 170 is the upper surface of the top plate 17. The edge portions 171 and 172 extend in a straight line along the V direction. The edge portions 171 and 172 are separated from each other in the X-axis direction.

[0099] The edge portions 173 and 174 respectively constitute the two end portions in the Y-axis direction of the upper surface 170. The edge portions 173 and 174 extend in a straight line along the X-axis direction. The edge portion 173 constitutes the end portion 170a in the Y2 direction of the upper surface 170. The edge portion 174 constitutes the end portion 170b in the Y1 direction of the upper surface 170.

[0100] The edge portion 175 connects the edge portion 171 and the edge portion 173 in the Y-axis direction. The edge portion 176 connects the edge portion 172 and the edge portion 174 in the Y-axis direction.

[0101] The edge portion 177 is located at the end portion in the X2 direction of the upper surface 170. The edge portion 177 connects the edge portion 172 and the edge portion 173 in the Y-axis direction. The edge portion 178 is located at the end portion in the X1 direction of the upper surface 170. The edge portion 178 connects the edge portion 171 and the edge portion 174 in the Y-axis direction.

[0102] Next, with reference to Figure 11 the imaginary parallelogram 140 corresponding to the outer shape of the upper surface 170 will be described. The imaginary parallelogram 140 is different from the aforementioned imaginary parallelogram 120. The imaginary parallelogram 140 has imaginary sides 141 to 144. The imaginary sides 141 and 142 are the hypotenuses along the V direction. The imaginary sides 141 and 142 are separated from each other in the X-axis direction. The imaginary sides 143 and 144 are along the X direction.

[0103] The imaginary parallelogram 140 has acute-angled portions 145, 146 and obtuse-angled portions 147, 148. The imaginary sides 142, 143 form the acute-angled portion 145. The imaginary side 141 and the imaginary side 144 form the acute-angled portion 146. The imaginary sides 141, 143 form the obtuse-angled portion 147. The imaginary side 142 and the imaginary side 144 form the obtuse-angled portion 148. When viewed from the Z-axis direction, all the head chips 20 are arranged inside the imaginary parallelogram 140. As Figure 4 shown, the upper surface 170 is arranged above the head chip 20.

[0104] The edge portion 175 is arranged outside the obtuse-angled portion 147 of the imaginary parallelogram 140 in the X-axis direction. The edge portion 175 is located in the X1 direction of the obtuse-angled portion 147.

[0105] The edge portion 176 is arranged outside the obtuse-angled portion 148 of the imaginary parallelogram 140 in the X-axis direction. The edge portion 176 is located in the X2 direction of the obtuse-angled portion 148.

[0106] The edge portion 177 extends linearly along the Y-axis direction between the acute-angled portion 145 and the head chip 20 closest to the acute-angled portion 145 in the X-axis direction. The edge portion 177 is located between the acute-angled portion 145 and the head chip 21C in the X-axis direction. The edge portion 177 is located between the acute-angled portion 145 and the head chip 22C in the X-axis direction.

[0107] The edge portion 178 extends linearly along the Y-axis direction between the acute-angled portion 146 and the head chip 20 closest to the acute-angled portion 146 in the X-axis direction. The edge portion 178 is located between the acute-angled portion 146 and the head chips 21A, 22B in the X-axis direction.

[0108] As Figure 11 shown, when viewed from the Z-axis direction, the upper surface 170 includes an end portion 170a, an end portion 170b, and a central portion 170c. The end portion 170a and the end portion 170b are in a rectangular shape that is elongated in the X-axis direction. In addition, the rectangular shape may include a substantially rectangular shape. For example, it also includes cases where the lengths of a pair of short sides are not exactly the same, or the lengths of a pair of long sides are not exactly the same, or there is an R shape at the corner. The end portion 170a is in a rectangular shape with the edge portion 175 and the edge portion 177 as short sides, and a straight line opposite to and parallel to the edge portion 173 and the edge portion 173 as long sides.

[0109] In addition, a straight line that faces the edge portion 173 and is parallel to the edge portion 173, in other words, is a straight line that connects the end edge on the side opposite to the edge portion 173 of the edge portion 175 and the end edge on the side opposite to the edge portion 173 of the edge portion 177. The end portion 170b has a rectangular shape with the edge portions 176 and 178 as short sides and a straight line that faces the edge portion 174 and is parallel to the edge portion 174 and the edge portion 174 as long sides.

[0110] In addition, a straight line that faces the edge portion 174 and is parallel to the edge portion 174, in other words, is a straight line that connects the end edge on the side opposite to the edge portion 174 of the edge portion 176 and the end edge on the side opposite to the edge portion 174 of the edge portion 178. The end portions 170a and 170b are separated from each other in the Y-axis direction. The central portion 170c is arranged between the end portion 170a and the end portion 170b in the Y-axis direction. A plurality of flow path tubes 14 are arranged on the central portion 170c.

[0111] The central portion 170c is a portion having a parallelogram shape when viewed from the Z-axis direction. The edge portions 171 and 172 of the upper surface 170 correspond to the hypotenuses of the parallelogram-shaped central portion 170c. In addition, the parallelogram shape includes a shape that is a substantially parallelogram, for example, a case where the lengths of the opposite hypotenuses are not exactly the same. The end portions 170a, the central portion 170c, and the end portion 170b are arranged in this order in the Y-axis direction. The central portion 170c is adjacent to the end portion 170a in the Y1 direction. That is, the parallelogram that forms the outer shape of the central portion 170c has a long side facing the edge portion 173 of the end portion 170a as one side. The central portion 170c is adjacent to the end portion 170b in the Y2 direction. That is, the parallelogram that forms the outer shape of the central portion 170c has a long side facing the edge portion 174 of the end portion 170b as one side. When the surface 170 is viewed in the Z-axis direction, the electrical connection portion 110 is arranged so as to overlap with the end portion 170a.

[0112] The upper surface 170 does not overlap with the acute angle portions 145 and 146 when viewed from the Z-axis direction. The upper surface 170 overlaps with the obtuse angle portions 147 and 148 when viewed from the Z-axis direction. The upper surface 170 extends outward in the X-axis direction to the outside of the obtuse angle portions 147 and 148. The upper surface 170 extends outward in the X1 direction to a position outside the vertex of the obtuse angle portion 147 and extends outward in the X2 direction to a position outside the vertex of the obtuse angle portion 148.

[0113] The range of the acute angle portion 145 can be set, for example, within a predetermined length L53 starting from the vertex 145a of the acute angle portion 145. The predetermined length L53 representing the range of the acute angle portion 145 can be set to be 10% or more and 50% or less of the maximum length L52 in the Y-axis direction of the electrical connection portion 110 (refer to Figure 13 ). The predetermined length L53 can also be 30% or more and 50% or less of the maximum length L52 in the Y-axis direction of the electrical connection portion 110. The range of the acute angle portion 146 can be set in the same manner as the range of the acute angle portion 145 is set.

[0114] The range of the obtuse angle portion 147 can be set, for example, in the same manner as the obtuse angle portion 133 of the imaginary parallelogram 120. The range of the obtuse angle portion 147 can be set based on the width W20 of the head chip 20. The range of the obtuse angle portion 147 can also be 10% or more and 50% or less of the maximum length L52 in the Y-axis direction of the electrical connection portion 110, similar to the acute angle portion 145. The range of the obtuse angle portion 148 can be set in the same manner as the obtuse angle portion 147.

[0115] Next, with reference to Figure 11 the size and position of the electrical connection portion 110 when observed in the Z-axis direction will be described. The electrical connection portion 110 extends outward in the X-axis direction beyond the vertex of the obtuse angle portion 147. Here, "the electrical connection portion 110 extends outward in the X-axis direction beyond the vertex of the obtuse angle portion 147" means that when observed from the Z-axis direction, a part of the electrical connection portion 110 is located in the X1 direction with respect to the straight line passing through the vertex of the obtuse angle portion 147 and extending along the Y-axis orthogonal to the X-axis. In addition, the electrical connection portion 110 extends outward in the X-axis direction beyond the imaginary side 141.

[0116] The electrical connection portion 110 does not extend outward in the X-axis direction beyond the vertex of the acute angle portion 145. The electrical connection portion 110 does not extend outward in the X-axis direction beyond the imaginary side 142.

[0117] Next, with reference to Figure 13 the relationship between the distance L111 between the points P1 and P2 of the imaginary parallelogram 140 and the maximum length L110 of the electrical connection portion 110 in the X-axis direction will be described. Figure 13 It is a schematic diagram showing the positional relationship between the imaginary parallelogram 140 opposed to the outer shape of the upper surface 170 and the electrical connection portion 110. In Figure 13 the imaginary parallelogram 140 is represented by a double-dashed line, and the area of the acute angle portion 145 is represented by a dotted line.

[0118] The point P1 is the intersection point of the imaginary side 141 and the imaginary side 143. The point P1 is the vertex of the obtuse angle portion 147. The point P2 is the intersection point of the imaginary line parallel to the imaginary side 143 passing through the end portion 110b of the electrical connection portion 110 in the Y-axis direction and the imaginary side 142. The end portion 110b of the electrical connection portion 110 is the end portion farther from the edge portion 174 among the two end portions in the Y-axis direction.

[0119] The maximum length L110 of the electrical connection portion 110 in the X-axis direction is longer than the distance L111 from the point P1 to the point P2 in the X-axis direction.

[0120] Next, with reference to Figure 13 the positional relationship between the center point P3 of the imaginary side 143 in the X-axis direction and the center point P4 of the electrical connection portion 110 in the X-axis direction will be described. The center point P4 of the electrical connection portion 110 in the X-axis direction is arranged at a position closer to the obtuse angle portion 147 in the X-axis direction compared to the center point P3 of the imaginary side 143. The distance L114 from the point P4 to the point P1 which is the vertex of the obtuse angle portion 147 is shorter than the distance L112 from the point P3 to the point P1.

[0121] Next, with reference to Figure 6 and Figure 11 the positional relationship between the ejection surface 30 and the upper surface 170 when viewed from the Z-axis direction will be described. When viewed from the Z-axis direction, the ejection surface 30 and the upper surface 170 have substantially the same outer shape. As Figure 6 shown, the edge portions 37, 38 of the ejection surface 30 are arranged closer to the inside in the X-axis direction compared to the edge portions 175, 176 of the upper surface 170.

[0122] Next, with reference to Figure 7 and Figure 11 the positional relationship between the electrical connection portion 110 and the plurality of nozzles N of the ejection surface 30 will be described. As Figure 7 shown, the ejection surface 30 has a plurality of nozzles N.

[0123] When viewed from the Z-axis direction, the plurality of nozzles N are arranged so as to overlap with the end portion 170a, the central portion 170c, and the end portion 170b of the upper surface 170. As Figure 11 shown, when viewed from the Z-axis direction, a part of the plurality of nozzles N overlaps with the electrical connection portion 110. In addition, when viewed from the Z-axis direction, the electrical connection portion 110 is arranged above the end portion 20b of the head chips 21A, 21B, 21C.

[0124] Next, with reference to Figure 13Next, the symmetry of the electrical connection portion 110 will be described. The electrical connection portion 110 is line-symmetric with respect to an imaginary straight line L41 that passes through the center point P4 of the electrical connection portion 110 in the X-axis direction and extends in the Y-axis direction.

[0125] Next, with reference to Figure 13 Next, the lengths L51 and L52 of the electrical connection portion 110 in the Y-axis direction will be described. The length L51 is the length of the electrical connection portion 110 in the Y-axis direction along the portion passing through the imaginary line L41 of the center point P4. The length L52 is the length of the end portion of the electrical connection portion 110 in the X-axis direction in the Y-axis direction. The length L51 of the central portion of the electrical connection portion 110 in the Y-axis direction is longer than the length L52 of the end portion in the X-axis direction in the Y-axis direction. In addition, as Figure 13 shown, in the present embodiment, in the X-axis direction, the width of the connector 18 is smaller than the width of the relay substrate 16.

[0126] In such a liquid ejection head 10, since in the X-axis direction, the upper surface 170 extends to the outside of the obtuse angle portion 147, the range where the electrical connection portion 110 can be arranged on the upper surface 170 can be expanded. For example, when the upper surface having an outer shape corresponding to the imaginary parallelogram 140 is set, the area where the electrical connection portion 110 can be provided becomes smaller. In the liquid ejection head 10, since the upper surface 170 is widened so as to extend to the outside of the obtuse angle portion 147, a wide-width connector 18 that is wider in the X-axis direction than in the Y-axis direction can be arranged.

[0127] In the liquid ejection head 10, the center point P4 of the electrical connection portion 110 is arranged in the X-axis direction at a position closer to the obtuse angle portion 147 than the center point P3 of the imaginary side 143. Therefore, the distance from the electrical connection portion 110 to the connection portion of the wiring substrate 12 that is connected to the wiring component 80 of the head chip 20 can be shortened.

[0128] In the liquid ejection head 10, when viewed from the Z-axis direction, the electrical connection portion 110 is arranged so as to overlap a part of the plurality of nozzles N. That is, the electrical connection portion 110 is arranged near the head chip 20. In the liquid ejection head 10, the wiring distance from the electrical connection portion 110 to the wiring component 80 provided on the head chip 20 can be shortened. In the liquid ejection head 10, by shortening the distance between the electrical connection portion 110 and the wiring component 80, miniaturization of the liquid ejection head 10 can be achieved.

[0129] In the liquid ejection head 10, the shape of the end portion 170a of the upper surface 170 is a rectangular shape elongated in the X-axis direction. According to such a liquid ejection head 10, when viewed from the Z-axis direction, it is easy to arrange the electrically connecting portion 110 elongated in the X-axis direction to overlap with the end portion 170a of the upper surface 170.

[0130] In the liquid ejection head 10, since the relay substrate 16 is covered by the covers 19A and 19B, the relay substrate 16 can be protected. In the liquid ejection head 10, for example, the situation where ink adheres to the relay substrate 16 is prevented. In addition, the electrically connecting portion 110 may also have a structure without the covers 19A and 19B.

[0131] The electrically connecting portion 110 is not limited to a structure including the relay substrate 16 and the connector 18 connected to the relay substrate 16. For example, it may also be a structure where the electrically connecting portion 110 includes the connector 12b provided on the wiring substrate 12 and does not include the relay substrate 16 and the connector 18. The thickness direction of the relay substrate 16 may not be along the Y-axis direction. For example, it may be along the X-axis direction, the Z-axis direction, or other directions. The electrically connecting portion 110 may also be arranged to pass through the opening formed on the end portion 170a of the upper surface 170.

[0132] Although one electrically connecting portion 110 is provided so as to overlap with the end portion 170a of the upper surface 170 when viewed from the Z-axis direction, it may also be a structure where two electrically connecting portions are provided, and the two electrically connecting portions are arranged to overlap with the end portions 170a and 170b of the upper surface 170 respectively.

[0133] Next, with reference to Figure 2 、 Figure 4 and Figure 6 the positioning portions 45 and 46 of the liquid ejection head 10 will be described. The liquid ejection head 10 includes the positioning portions 45 and 46. The positioning portions 45 and 46 are positioned with respect to the head holding member 53 that holds a plurality of liquid ejection heads 10. In addition, regarding the head holding member 53, reference will be made to Figure 18 and will be described later.

[0134] The positioning portions 45 and 46 are provided on the flange portion 41. The positioning portions 45 and 46 are separated from each other in the X-axis direction. On the flange portion 41, the positioning portion 45 is arranged at the end in the X2 direction, and the positioning portion 46 is arranged at the end in the X1 direction. The positioning portions 45 and 46 have openings penetrating in the Z-axis direction, which is the thickness direction of the flange portion 41. Protrusions on the opposite side, which are the objects to be positioned, are embedded in the positioning portions 45 and 46. The protrusions on the opposite side are, for example, provided on the head holding member 53.

[0135] The convex portion on the other side is, for example, a cylindrical pin. The inner peripheral surfaces of the openings of the positioning portions 45 and 46 are respectively in contact with the convex portion on the other side in a direction intersecting the Z-axis direction. Thereby, the movement of the liquid ejection head 10 in the X-axis direction and the Y-axis direction is restricted and thus positioned.

[0136] The positioning portions 45 and 46 are not limited to the openings, and may also be other concave portions. The positioning portions 45 and 46 may also be convex portions embedded in the concave portions or openings on the other side. When viewed from the Z-axis direction, the shapes of the positioning portions 45 and 46 may be circular, rectangular, or other shapes.

[0137] In addition, the opening shapes of the positioning portions 45 and 46 when viewed from the Z-axis direction may also be different in the Z-axis direction. In the present embodiment, the opening shape of the positioning portion 45 is a substantially square, and the opening shape of the positioning portion 46 is a substantially rectangular shape that is long and narrow in the X-axis direction, which is the direction in which the positioning portions 45 and 46 are arranged. By adopting this method, even if it is offset due to the manufacturing error in the X-axis direction of the convex portions (positioning pins 47 and 48) on the other side, positioning can be performed. In addition, by setting the opening shape of at least one of the positioning portions 45 and 46 to an elliptical shape that is long and narrow in the X-axis direction, which is the direction in which the positioning portions 45 and 46 are arranged, the same effect can also be obtained.

[0138] In addition, when the positioning portions 45 and 46 are provided as convex portions, the convex portions may protrude from the flange portion 41 in the Z1 direction or in the Z2 direction. In addition, the positioning portions 45 and 46 may also be provided on the flange portion 42. The positioning portions 45 and 46 may be provided on other parts of the bracket 13, or may be provided on parts other than the bracket 13 in the liquid ejection head 10.

[0139] Next, with reference to Figure 14 the outer shape 150 of the liquid ejection head 10 when viewed in the Z-axis direction will be described. Figure 14 is a bottom view showing the ejection surface 30 of the liquid ejection head 10. In Figure 14 , the outer shape of the head chip 20 is represented by a dotted line, and the imaginary parallelogram 160 is represented by a double-dot chain line. When viewed from the Z-axis direction, the outer shape 150 of the liquid ejection head 10 is the outer shape of the bracket 13. The bracket 13 has edge portions 151 to 158. The edge portions 151 to 158 constitute the outer shape 150 of the liquid ejection head 10. The edge portions 151 and 152 extend linearly along the V direction. The edge portions 151 and 152 are separated from each other in the X-axis direction.

[0140] The edge portions 153 and 154 are arranged at both end portions of the bracket 13 in the Y-axis direction. The edge portions 153 and 154 are separated from each other in the Y-axis direction and extend in a straight line along the X-axis direction. The edge portion 153 constitutes the end portion of the bracket 13 in the Y1 direction. The edge portion 154 constitutes the end portion of the bracket 13 in the Y2 direction. The edge portion 153 is arranged at the end portion of the flange portion 41 in the Y1 direction. The edge portion 154 is arranged at the end portion of the flange portion 42 in the Y2 direction.

[0141] The edge portion 155 is arranged at the end portion of the bracket 13 in the X1 direction. The edge portion 155 connects the edge portion 151 and the edge portion 153 in the Y-axis direction. The edge portion 155 extends in a straight line along the Y-axis direction. The edge portion 156 is arranged at the end portion of the bracket 13 in the X2 direction. The edge portion 156 connects the edge portion 152 and the edge portion 154 in the Y-axis direction. The edge portion 156 extends in a straight line along the Y-axis direction.

[0142] The edge portion 157 is opposed to the edge portion 155 in the X-axis direction and extends in a straight line along the Y-axis direction. The edge portion 157 connects the edge portion 152 and the edge portion 153 in the Y-axis direction. The edge portion 158 is opposed to the edge portion 156 in the X-axis direction and extends in a straight line along the Y-axis direction. The edge portion 158 connects the edge portion 151 and the edge portion 154 in the Y-axis direction.

[0143] Next, a hypothetical parallelogram 160 corresponding to the outer shape 150 of the liquid ejection head 10 will be described. The hypothetical parallelogram 160 is different from the aforementioned hypothetical parallelograms 120 and 140. The hypothetical parallelogram 160 has hypothetical sides 161 to 164. The hypothetical sides 161 and 162 are hypotenuses along the V direction. The hypothetical side 161 is arranged along the edge portion 151 of the bracket 13. The hypothetical side 162 is arranged along the edge portion 152 of the bracket 13. The hypothetical sides 161 and 162 are separated from each other in the X-axis direction. The hypothetical side 163 is arranged along the edge portion 153 of the bracket 13. The hypothetical side 164 is arranged along the edge portion 154 of the bracket 13. The hypothetical sides 163 and 164 are along the X-axis direction.

[0144] The hypothetical parallelogram 160 has acute angle portions 165 and 166 and obtuse angle portions 167 and 168. The hypothetical sides 161 and 163 constitute the acute angle portion 165. The hypothetical sides 162 and 164 constitute the acute angle portion 166. The hypothetical sides 162 and 163 constitute the obtuse angle portion 167. The hypothetical sides 161 and 164 constitute the obtuse angle portion 168. When viewed from the Z-axis direction, all the head chips 20 are located inside the hypothetical parallelogram 160.

[0145] Next, the positional relationship between the positioning portion 45 and the imaginary parallelogram 160 will be described. When viewed from the Z-axis direction, the positioning portion 45 is arranged at a position not overlapping with the imaginary parallelogram 160. In the X-axis direction, the positioning portion 45 is arranged outside the obtuse angle portion 167 of the imaginary parallelogram 160. The positioning portion 45 is arranged in the X2 direction of the obtuse angle portion 167.

[0146] Next, the positional relationship between the positioning portion 46 and the imaginary parallelogram 160 will be described. As Figure 14 and Figure 15 shown, when viewed from the Z-axis direction, the positioning portion 46 overlaps with the imaginary parallelogram 160. The positioning portion 46 does not overlap with the acute angle portion 165 of the imaginary parallelogram 160.

[0147] The range of the acute angle portion 165 can be set, for example, within a predetermined length L61 starting from the vertex 165a of the acute angle portion 165. The predetermined length L61 can be set, for example, to 80% of the distance L62 from the vertex 165a to the head chip 22A closest to the vertex 165a. The predetermined length L61 can also be, for example, 50% or more and 90% or less of the distance L62.

[0148] Next, with reference to Figure 14 the screw holes 61 to 64 of the liquid ejection head 10 will be described. The screw holes 61 to 64 are an example of a fixing portion for fixing the liquid ejection head 10 to the head holding member 53. The screw holes 61 and 62 are provided on the flange portion 41, and the screw holes 63 and 64 are provided on the flange portion 42. The screw holes 61 and 62 are arranged at both end portions in the long side direction of the flange portion 41. The screw holes 63 and 64 are arranged at both end portions in the long side direction of the flange portion 42.

[0149] The screw hole 61 is adjacent to the positioning portion 45 in the X-axis direction. The screw hole 61 is arranged in the X1 direction of the positioning portion 45. The screw hole 61 is arranged in the Y1 direction of the end portion 20a of the head chip 22C. The screw hole 61 does not overlap with the imaginary parallelogram 160. The screw hole 61 is arranged outside the obtuse angle portion 167. The screw hole 61 is located in the X2 direction of the obtuse angle portion 167. The screw hole 61 is arranged between the obtuse angle portion 167 and the positioning portion 45 in the X-axis direction.

[0150] The screw hole 62 is adjacent to the positioning portion 46 in the X-axis direction. The screw hole 62 is arranged in the X2 direction of the positioning portion 46. The screw hole 62 is arranged in the Y1 direction of the end portion 20a of the head chip 22A. When viewed from the Z-axis direction, the screw hole 62 does not overlap with the acute angle portion 165.

[0151] The screw holes 63 are arranged in the Y2 direction of the end portion 20b of the head chip 21C. When viewed from the Z-axis direction, the screw holes 63 are not arranged at the acute-angle portion 166. The screw holes 64 are arranged in the Y2 direction of the end portion 20b of the head chip 21A. The screw holes 64 do not overlap with the imaginary parallelogram 160. The screw holes 64 are arranged outside the obtuse-angle portion 168. The screw holes 64 are located in the X1 direction of the obtuse-angle portion 168.

[0152] Therefore, in the present embodiment, the distance between the screw holes 61 and 62 in the X direction is longer than the distance between the screw holes 61 and 62 in the X-axis direction when the screw holes 61 and 62 are provided at the portion overlapping with the imaginary parallelogram 160 of the flange portion 41. Therefore, when the flange portion 41 is fixed to the head holding member 53 by the screws inserted through the screw holes 61 and 62, it is possible to reduce the positional deviation such that the liquid ejection head 10 rotates and moves centering around the screw hole 61 or the screw hole 62. The same applies to the screw holes 63 and 64.

[0153] In addition, the screw holes 61 to 64 are arranged outside the ejection surface 30 in the Y-axis direction. At least a part of each of the screw holes 61 to 64 is arranged within the range H of the plurality of nozzles N existing on the ejection surface 30 with respect to the X-axis direction. If specifically described in the present embodiment, all of the screw holes 61, 62, and 64 are arranged within the range H with respect to the X-axis direction, and a part of the screw hole 63 is arranged within the range H with respect to the X-axis direction.

[0154] Alternatively, all of the screw holes 61 to 64 may be arranged within the range H with respect to the X-axis direction. Thus, by arranging the screw holes 61 to 64 near the plurality of nozzles N with respect to the X-axis direction, it is possible to reduce the decrease in the alignment accuracy of the nozzles N caused by the rotational deviation of the ejection surface 30 with the Z-axis as the rotation axis with respect to the head holding member 53.

[0155] Screws are inserted through the screw holes 61 to 64 respectively. By the screws inserted through the screw holes 61 to 64, the flange portions 41 and 42 are tightened with respect to the head holding member 53. Thereby, the liquid ejection head 10 is fixed with respect to the head holding member 53.

[0156] According to the liquid ejection head 10, positioning portions 45 and 46 are provided at both end portions in the long side direction of the flange portion 41. Since the positioning portions 45 and 46 can be arranged so as to be separated from each other in the X-axis direction, the distance between the positioning portions 45 and 46 can be extended. In the liquid ejection head 10, by increasing the distance between the positioning portions 45 and 46, the positioning accuracy is improved.

[0157] In the liquid ejection head 10, the positioning portion 45 is disposed outside the obtuse angle portion 167. In the liquid ejection head 10, the position of the positioning portion 45 can be arranged in the X2 direction as compared with the bracket having an outer shape corresponding to the imaginary parallelogram 160. In the liquid ejection head 10, it is possible to avoid a situation where the positioning portions 45 and 46 are arranged close to each other, thereby suppressing a decrease in positioning accuracy.

[0158] In the liquid ejection head 10, the positioning portion 46 does not overlap with the acute angle portion 165 of the imaginary parallelogram 160. In order to reduce the outer shape of the liquid ejection head 10 in the X-axis direction, even when the outer shape 150 of the liquid ejection head 10 does not overlap with the acute angle portion 165 when viewed from the Z-axis direction, as described above, since the positioning portion 45 is disposed outside the obtuse angle portion 167, it is possible to avoid a situation where the positioning portions 45 and 46 are arranged close to each other, thereby suppressing a decrease in positioning accuracy.

[0159] In the liquid ejection head 10, the positioning portion 46 does not overlap with the acute angle portion 165 of the imaginary parallelogram 160. Further, the flange portion 41 has a rectangular shape that is elongated in the X-axis direction. The rectangular shape also includes a substantially rectangular shape, for example, it also includes a case where the corner portion has an R shape. For example, in the bracket having an outer shape corresponding to the imaginary parallelogram 160, when the positioning portion 46 is arranged at a position overlapping with the acute angle portion 165, an opening is formed at a portion that becomes a tapered shape. In such a case, the strength of the portion near the acute angle portion 165 will decrease, and thus, in the process of repeatedly using the liquid ejection head 10, the portion near the acute angle portion 165 may be damaged.

[0160] However, in the liquid ejection head 10, the positioning portion 46 is not arranged at a position overlapping with the acute angle portion 165. Thereby, a situation where the strength of the portion near the positioning portion 46 decreases is avoided, and thus the possibility of damage to the flange portion 41 is reduced. As a result, an improvement in the reliability of the liquid ejection head 10 is achieved.

[0161] In addition, in the liquid ejection head 10, when viewed from the Z-axis direction, the edge portions 155 and 156 of the bracket 13 do not overlap with the acute angle portions 165 and 166 of the imaginary parallelogram 160. In the X-axis direction, the edge portions 155 and 156 are arranged between the plurality of head chips 20 and the acute angle portions 165 and 166. Thereby, an increase in the size of the bracket 13 in the X-axis direction is avoided, and thus an increase in the size of the liquid ejection head 10 is avoided.

[0162] Next, with reference to Figures 16 to 18 the liquid ejection device 1B according to the second embodiment will be described. Figure 16 FIG. is a schematic diagram showing an outline of the liquid ejection device 1B according to the second embodiment.

[0163] Figure 17 The figure showing the liquid ejecting device 1B when viewed from the direction of the central axis of the supply reel 6.

[0164] Figure 18 The bottom view showing a plurality of line heads 50A, 50B separated in the conveyance direction of the medium PP.

[0165] The difference between the liquid ejecting device 1B according to the second embodiment and the liquid ejecting device 1A according to the first embodiment lies in that the former is provided with a plurality of line heads 50A, 50B. In the description of the liquid ejecting device 1B of the second embodiment, the description same as that of the liquid ejecting device 1A of the first embodiment is omitted.

[0166] The line heads 50A, 50B have the same structure as the line head 50 of the first embodiment. As Figures 16 to 18 shown, the line head 50A is formed by arranging a plurality of liquid ejecting heads 10A. The line head 50B is formed by arranging a plurality of liquid ejecting heads 10B. The liquid ejecting heads 10A, 10B have the same structure as the liquid ejecting head 10 of the liquid ejecting device 1A.

[0167] In Figure 17 it, the X A axis direction, Y A axis direction and Z A axis direction are shown as three directions related to the liquid ejecting head 10A. These X A axis direction, Y A axis direction and Z A axis direction correspond to the X axis direction, Y axis direction and Z axis direction on the liquid ejecting head 10.

[0168] The X B axis direction, Y B axis direction and Z B axis direction are shown as three directions related to the liquid ejecting head 10B. These X B axis direction, Y B axis direction and Z B axis direction correspond to the X axis direction, Y axis direction and Z axis direction on the liquid ejecting head 10.

[0169] In addition, in the following description, when indicating the X axis direction, it means the X A axis direction for the liquid ejecting head 10A and the X B axis direction for the liquid ejecting head 10B. Similarly, when indicating the Y axis direction, it means the Y A axis direction for the liquid ejecting head 10A and the Y BAxis direction. When indicating the Z-axis direction, it refers to the Z A axis direction for the liquid ejection head 10A and the Z B axis direction for the liquid ejection head 10B.

[0170] The line heads 50A and 50B are arranged separately from each other in the conveyance direction DM. The conveyance direction DM is along the circumferential direction of the conveyance drum 6 when viewed from the central axis direction of the conveyance drum 6. The central axis direction of the conveyance drum 6 is along the X-axis direction. The ejection surfaces 30 of the liquid ejection heads 10A and 10B face the outer peripheral surface 6a of the conveyance drum 6. The normal lines L30 A 、L30 B are in the direction along the normal line direction of the outer peripheral surface 6a of the conveyance drum 6. In Figure 17 is shown the normal line L30 A passing through the center in the Y-axis direction of the ejection surface 30 of the liquid ejection head 10A, and is shown the normal line L30 B passing through the center in the Y-axis direction of the ejection surface 30 of the liquid ejection head 10B.

[0171] Flange portions 41A and 42A are provided on the liquid ejection head 10A. Flange portions 41B and 42B are provided on the liquid ejection head 10B. The flange portions 41A and 41B have the same structure as the flange portion 41 of the liquid ejection head 10, and the flange portions 42A and 42B have the same structure as the flange portion 42 of the liquid ejection head 10.

[0172] When viewed in the X-axis direction, the flange portion 41A of the liquid ejection head 10A extends toward the liquid ejection head 10B in the Y-axis direction. The flange portion 41A is arranged in the Y-axis direction at a position closer to the liquid ejection head 10B than the center of the ejection surface 30.

[0173] When viewed in the X-axis direction, the flange portion 42A of the liquid ejection head 10A extends toward the side opposite to the liquid ejection head 10B in the Y-axis direction. The flange portion 42A is arranged in the Y-axis direction at a position farther from the liquid ejection head 10B than the center of the ejection surface 30.

[0174] When viewed in the X-axis direction, the flange portion 41B of the liquid ejection head 10B extends toward the liquid ejection head 10A in the Y-axis direction. The flange portion 41B is arranged in the Y-axis direction at a position closer to the liquid ejection head 10A than the center of the ejection surface 30.

[0175] When observed in the X-axis direction, the flange portion 42B of the liquid ejection head 10B protrudes in the Y-axis direction toward the side opposite to the liquid ejection head 10A. The flange portion 42B is arranged in the Y-axis direction at a position farther from the liquid ejection head 10A than the center of the ejection surface 30.

[0176] Next, the head holding member 53 will be described with reference to Figure 18 The liquid ejection device 1B includes a holding member 53 that holds 50A and 50B. The head holding member 53 is formed of, for example, stainless steel. The material of the head holding member 53 is not limited to stainless steel and may be other materials such as metal or resin.

[0177] The head holding member 53 has fixing surfaces 54 to 57. The fixing surfaces 54 and 55 are used for fixing the liquid ejection head 10A, and the fixing surfaces 56 and 57 are used for fixing the liquid ejection head 10B. The fixing surfaces 54 to 57 extend in the X-axis direction. In Figure 18 the state before the liquid ejection head 10B is installed is partially shown.

[0178] Openings 51A, 51B, 52A, and 52B are formed in the head holding member 53. In the Z-axis direction, the openings 51A and 51B are arranged closer to the supply reel 6, and the openings 52A and 52B are arranged farther from the supply reel 6.

[0179] The opening 51A is an opening for holding the liquid ejection head 10A. The opening 51A is continuous in the X-axis direction between the fixing surfaces 54 and 55. A plurality of liquid ejection heads 10A are inserted into the opening 51A. The opening 51A is formed on the surface of the head holding member 53 that faces the outer peripheral surface 6a of the supply reel 6. On the head holding member 53, the surface closer to the outer peripheral surface 6a of the supply reel 6 becomes the ejection surface of the head holding member 53. A plurality of liquid ejection heads 10A are inserted into the opening 51A from the ejection surface side of the head holding member 53 and are thus fixed to the head holding member 53.

[0180] The opening 51B is an opening for holding the liquid ejection head 10B. The opening 51B is continuous in the X-axis direction between the fixing surfaces 56 and 57. A plurality of liquid ejection heads 10B are inserted into the opening 51B. The opening 51B is formed on the ejection surface of the head holding member 53. A plurality of liquid ejection heads 10B are inserted into the opening 51B from the ejection surface side of the head holding member 53 and are thus fixed to the head holding member 53.

[0181] The opening portion 52A is a separate opening portion corresponding to each liquid ejection head 10A. The electrical connection portion 110 of the liquid ejection head 10A passes through the opening portion 52A and extends outward from the head holding member 53.

[0182] The opening portion 52B is a separate opening portion corresponding to each liquid ejection head 10B. The electrical connection portion 110 of the liquid ejection head 10B passes through the opening portion 52B and extends outward from the head holding member 53.

[0183] The flange portion 41A of the liquid ejection head 10A is fixed on the fixing surface 54, and the flange portion 42A is fixed on the fixing surface 55. The flange portion 41B of the liquid ejection head 10B is fixed on the fixing surface 55, and the flange portion 42B is fixed on the fixing surface 57.

[0184] Positioning pins 47 and 48 are respectively provided on the fixing surfaces 54 and 56. The positioning pins 47 and 48 are, for example, cylindrical. The positioning pin 47 is inserted into the positioning portion 45. The positioning pin 48 is inserted into the positioning portion 46. The outer diameter of the positioning pin 47 is slightly smaller than the inner diameter of the opening portion of the positioning portion 45. The outer diameter of the positioning pin 48 is slightly smaller than the inner diameter of the opening portion of the positioning portion 46. Therefore, when the positioning pin 47 is inserted into the opening portion of the positioning portion 45, the positioning pin 47 is pressed by the inner peripheral surface of the opening portion of the positioning portion 45. The positioning portion 46 and the positioning pin 48 have the same structure.

[0185] The hardness of the positioning pins 47 and 48 is higher than that of the flange portions 41A and 41B. For example, consider the case of using the head holding member 53 as a non-replaceable component fixed to the liquid ejection device 1B and using the liquid ejection head 10A as a replaceable component. If the hardness of the positioning pin 47 of the head holding member 53 as a non-replaceable component is set to be higher than the hardness of the positioning portion 45 of the liquid ejection head 10A as a replaceable component, the positioning pin 47 is less likely to be worn due to positioning, and thus there is no need to replace the head holding member 53, thereby suppressing the maintenance cost of the liquid ejection device 1B.

[0186] Nut portions 65 and 66 are provided on the fixing surfaces 54 and 56, and nut portions 67 and 68 are provided on the fixing surfaces 55 and 57. In Figure 18 The nut portions 65 to 68 before the screws are installed are shown. The nut portion 65 is provided at a position corresponding to the screw hole 61, and the nut portion 66 is provided at a position corresponding to the screw hole 62. The nut portion 67 is provided at a position corresponding to the screw hole 63, and the nut portion 68 is provided at a position corresponding to the screw hole 64. The screws inserted through the screw holes 61 to 64 are respectively installed in the corresponding nut portions 65 to 68. Thus, the liquid ejection heads 10A and 10B are fixed relative to the head holding member 53.

[0187] Next, refer toFigure 17 Next, the arrangement of the electrical connection portions 110 on the liquid ejecting device 1B will be described. In a state where the liquid ejecting heads 10A and 10B are fixed relative to the head holding member 53, the electrical connection portion 110 of the liquid ejecting head 10A is arranged on the side away from the liquid ejecting head 10B with respect to the center of the ejection surface 30 in the Y-axis direction. Similarly, the electrical connection portion 110 of the liquid ejecting head 10B is arranged on the side away from the liquid ejecting head 10A with respect to the center of the ejection surface 30 in the Y-axis direction.

[0188] According to such a liquid ejecting device 1B, flange portions 41A and 41B are provided on the side approaching each other in the conveyance direction DM. Thereby, the positioning portions 45 and 46 arranged on the flange portions 41A and 41B can be arranged close to each other to arrange the line heads 50A and 50B. As a result, positional deviation between the line heads 50A and 50B can be suppressed.

[0189] According to such a liquid ejecting device 1B, the electrical connection portions 110 are arranged on the side away from each other in the conveyance direction DM. Thereby, a distance between the respective connectors 18 of the line heads 50A and 50B can be ensured. For example, when connecting a cable to the connector 18 of the line head 50A, the cable connected to the connector 18 of the line head 50B does not cause interference. In the usage state of the liquid ejecting device 1B, the distance between the cable connected to the connector 18 of the line head 50A and the cable connected to the connector 18 of the line head 50B is appropriately maintained so that the cables do not approach each other too closely.

[0190] The head holding member 53 may also be formed to be point-symmetrical when viewed from the direction normal to the outer peripheral surface 6a of the conveyance reel 6. For example, as Figure 18 shown, the head holding member 53 is formed to be point-symmetrical with respect to the center point P53. The line heads 50A and 50B are arranged to be point-symmetrical with respect to the center point P53.

[0191] Next, with reference to Figure 19 the liquid ejecting head 10C according to the first modification will be described. Figure 19 is a bottom view showing the ejection surface of the liquid ejecting head according to the first modification. In the description of the liquid ejecting head 10C, the same description as that of the aforementioned liquid ejecting head 10 is omitted. In the liquid ejecting head 10C according to the first modification, the number and arrangement of the head chips 20 are different from those of the aforementioned liquid ejecting head 10. The liquid ejecting head 10C has an ejection surface 30 whose shape is different from that of the ejection surface 30 of the liquid ejecting head 10. The shape of the imaginary parallelogram 120 of the liquid ejecting head 10C is different from the shape of the imaginary parallelogram 120 of the liquid ejecting head 10.

[0192] The liquid ejection head 10C includes a plurality of head chips 20 extending along the V direction. The V direction may be different from or the same as the V direction on the liquid ejection head 10. The liquid ejection head 10C includes a plurality of chip sets 225A to 225D. The plurality of chip sets 225A to 225D are arranged in this order in the Y1 direction.

[0193] The chip set 225A includes head chips 221A, 221B, and 221C as the plurality of head chips 20. These head chips 221A, 221B, and 221C are arranged in this order in the X2 direction. The head chip 221A is inscribed in the edge portion 31.

[0194] The chip set 225B includes head chips 222A, 222B, and 222C as the plurality of head chips 20. These head chips 222A, 222B, and 222C are arranged in this order in the X2 direction.

[0195] The chip set 225C includes head chips 223A, 223B, and 223C as the plurality of head chips 20. These head chips 223A, 223B, and 223C are arranged in order in the X2 direction.

[0196] The chip set 225D includes head chips 224A, 224B, and 224C as the plurality of head chips 20. These head chips 224A, 224B, and 224C are arranged in this order in the X2 direction. The head chip 224C is inscribed in the edge portion 32.

[0197] Next, a hypothetical parallelogram 120 corresponding to the arrangement of the head chips 20 of the liquid ejection head 10C will be described. All the head chips 20 are located inside the hypothetical parallelogram 120. The head chip 221A is inscribed with respect to the hypothetical side 121. The head chip 224C is inscribed with respect to the hypothetical side 122. The head chips 224A, 22B, and 224C are inscribed with respect to the hypothetical side 123. The head chips 221A, 221B, and 221C are inscribed with respect to the hypothetical side 124. Among the plurality of head chips 20, there may be a head chip 20 that is not inscribed in the hypothetical parallelogram 120.

[0198] In the liquid ejection head 10C, similar to the liquid ejection head 10, the ejection surface 30 does not overlap with the acute angle portions 131 and 132 either. The ejection surface 30 overlaps with the entire regions of both the obtuse angle portions 133 and 134 of the imaginary parallelogram 120. Only one head chip 221A is inscribed with respect to the imaginary side 121. The plurality of head chips 20 includes the head chip 221A inscribed at the closest position to the acute angle portion 131 with respect to the imaginary side 121, and the head chip 222A inscribed at the closest position to the acute angle portion 131 with respect to the imaginary side 123. The head chip 221A is an example of the first head chip, and the head chip 224A is an example of the second head chip.

[0199] The edge portion 35 of the liquid ejection head 10C extends along the Y-axis direction between the acute angle portion 131 and the head chip 224A in the X-axis direction. The edge portion 35 of the liquid ejection head 10C is an example of the first edge portion. When viewed from the X direction, the edge portion 35 overlaps with the head chips 221A, 222A, and 223A that do not contact the imaginary side 123. When viewed from the X direction, the edge portion 35 overlaps with the head chip 221A that contacts the imaginary side 124.

[0200] Similar to the edge portion 37 of the liquid ejection head 10, the edge portion 37 of the liquid ejection head 10C is arranged outside the obtuse angle portion 133 in the X-axis direction. The edge portion 37 of the liquid ejection head 10C is an example of the second edge portion.

[0201] The liquid ejection head 10C having such an ejection surface 30 exhibits the same effects as the liquid ejection head 10 according to the first embodiment. The length of the ejection surface 30 along the X-axis direction is shorter than the length of the imaginary parallelogram 120 along the X-axis direction. According to such a liquid ejection head 10C, compared with the case of a structure having the same outer shape as the imaginary parallelogram 120, the length in the X-axis direction can be shortened.

[0202] Next, with reference to Figure 20 the liquid ejection head 10D according to the second modification will be described. Figure 20 Fig. is a bottom view showing the ejection surface of the liquid ejection head according to the second modification. In the description of the liquid ejection head 10D, the same description as that of the aforementioned liquid ejection head 10 is omitted. In the liquid ejection head 10D according to the first modification, the number and arrangement of the head chips 20 are different from those of the aforementioned liquid ejection head 10. The liquid ejection head 10D has an ejection surface 30 having a shape different from that of the ejection surface 30 of the liquid ejection head 10. The shape of the imaginary parallelogram 120 of the liquid ejection head 10D is different from the shape of the imaginary parallelogram 120 of the liquid ejection head 10.

[0203] The liquid ejection head 10D includes a plurality of head chips 20 extending along the V direction. The V direction may be different from or the same as the V direction on the liquid ejection head 10. The liquid ejection head 10D includes a plurality of chip sets 325A and 325B. The plurality of chip sets 325A and 325B are arranged in this order in the Y1 direction.

[0204] The chip set 325A includes head chips 321A, 321B, and 321C as the plurality of head chips 20. These head chips 321A, 321B, and 321C are arranged in this order in the X2 direction. The head chip 321A is inscribed in the imaginary side 121. The head chip 321B is inscribed in the imaginary side 122.

[0205] The chip set 325B includes head chips 322A, 322B, and 322C as the plurality of head chips 20. These head chips 322A, 322B, and 322C are arranged in this order in the X2 direction. The head chip 322A is inscribed in the imaginary side 121. The head chip 322C is inscribed in the imaginary side 122.

[0206] The head chips 321A and 322A are arranged along their long side directions. The head chips 321B and 322B are arranged along their long side directions. The head chips 321C and 322C are arranged along their long side directions.

[0207] In the liquid ejection head 10D, similar to the liquid ejection head 10, the ejection surface 30 does not overlap with the acute angle portions 131 and 132. The ejection surface 30 overlaps with the entire regions of both the obtuse angle portions 133 and 134 of the imaginary parallelogram 120. Two head chips 321A and 322A are inscribed in the imaginary side 121. The head chip 322A closest to the acute angle portion 131 is in contact with both the imaginary side 121 and the imaginary side 123.

[0208] The edge portion 35 of the liquid ejection head 10D extends along the Y-axis direction between the acute angle portion 131 and the head chip 322A in the X-axis direction. The edge portion 35 of the liquid ejection head 10D is an example of a first edge portion. The edge portion 35 overlaps with the head chip 322A in contact with the imaginary side 123 when viewed from the X direction. The edge portion 35 does not overlap with the head chip 321A in contact with the imaginary side 124 when viewed from the X direction.

[0209] Similar to the edge portion 37 of the liquid ejection head 10, the edge portion 37 of the liquid ejection head 10D is arranged outside the obtuse angle portion 133 in the X-axis direction. The edge portion 37 of the liquid ejection head 10C is an example of a second edge portion.

[0210] The liquid ejector head 10D having such an ejection surface 30 exhibits the same effects as the liquid ejector head 10 according to the first embodiment. The length of the ejection surface 30 in the X-axis direction is shorter than the length of the imaginary parallelogram 120 in the X-axis direction. With such a liquid ejector head 10D, the length in the X-axis direction can be shortened compared to the case of a structure having the same outer shape as the imaginary parallelogram 120.

[0211] Next, with reference to Figure 21 the liquid ejector head 10E according to the third modification will be described. Figure 21 FIG. is a plan view showing the ejection surface 30 of the liquid ejector head 10E according to the third modification. The liquid ejector head 10E according to the third modification is different from the liquid ejector head 10 according to the first embodiment in that it includes flange portions 41C, 41D, 42C, and 42D having a different structure from the flange portions 41 and 42. In addition, in the description of the liquid ejector head 10E, the same description as that of the liquid ejector head 10 according to the first embodiment is omitted.

[0212] Flange portions 41C, 41D, 42C, and 42D that protrude in the Y-axis direction are formed on the bracket 13 of the liquid ejector head 10E. The flange portions 41C and 41D protrude in the Y1 direction, and the flange portions 42C and 42D protrude in the Y2 direction.

[0213] The flange portions 41C and 41D are separated from each other in the X-axis direction. A cutout portion is formed between the flange portions 41C and 41D in the X-axis direction. The flange portion 41C is located in the X2 direction of the flange portion 41D. A positioning portion 45 and a screw hole 61 are formed on the flange portion 41C. A positioning portion 46 and a screw hole 62 are formed on the flange portion 41D.

[0214] The flange portions 42C and 42D are separated from each other in the X-axis direction. A cutout portion is formed between the flange portions 42C and 42D in the X-axis direction. The flange portion 42C is located in the X1 direction of the flange portion 42D. A positioning portion 45 and a screw hole 61 are formed on the flange portion 42C. A screw hole 63 is formed on the flange portion 42D.

[0215] In such a liquid ejector head 10E, the same effects as those of the liquid ejector head 10 according to the first embodiment are also exhibited.

[0216] Next, with reference to Figure 22 the liquid ejector device 1C according to the third embodiment will be described. Figure 22 FIG. is a schematic diagram showing the outline of the liquid ejector device 1C according to the third embodiment. Figure 22The liquid ejection device 1C according to the third embodiment shown is a serial printing device. The liquid ejection device 1C includes a plurality of liquid ejection heads 10 arranged in the conveyance direction DM of the medium PP. The plurality of liquid ejection heads 10 are arranged along the X-axis direction. In the description of the liquid ejection device 1C according to the third embodiment, the same description as that of the liquid ejection device 1A of the first embodiment is omitted.

[0217] The liquid ejection device 1C includes a head conveyance mechanism 7. The head conveyance mechanism 7 has a carriage 8 and an endless belt 9. The carriage 8 holds the plurality of liquid ejection heads 10. The carriage 8 is connected to the endless belt 9. The carriage 8 is conveyed by the endless belt 9 and reciprocates in the main scanning direction.

[0218] When the liquid ejection device 1C performs a printing process, while conveying the medium PP in the sub-scanning direction intersecting the main scanning direction and causing the liquid ejection head 10 to reciprocate in the main scanning direction, ink is ejected from the liquid ejection head 10. Thereby, dots corresponding to the print data are formed on the medium PP.

[0219] In the liquid ejection device 1C as such a serial printer, the liquid ejection head 10 can also be applied.

[0220] In addition, the foregoing embodiments merely show representative modes of the present invention, and the present invention is not limited to the foregoing embodiments, and various changes and additions can be implemented without departing from the gist of the present invention.

[0221] Although in the liquid ejection device 1A exemplified in the foregoing mode, for example, as Figure 10 shown, in adjacent liquid ejection heads 10, the width W11 of the gap between the edge portion 37 of one liquid ejection head 10 and the edge portion 35 of the other liquid ejection head 10 is greater than the width W12 of the gap between the brackets 13, but the width W11 may also be the same as the width W12. In other words, the length L37 of the edge portion 37 of the liquid ejection head 10 may be set to be the same as the length L35 of the edge portion 35. Similarly, by setting the length of the edge portion 38 of the liquid ejection head 10 to be the same as the length of the edge portion 36, the width of the gap between the edge portion 38 of one liquid ejection head 10 and the edge portion 36 of the other liquid ejection head 10 can be set to be the same as the width W12 of the gap between the brackets 13. In this case, the wall surface 13a defining the edge portion 37 may also be arranged at the same position in the X-axis direction as the wall surface 13b defining the edge portion 157 of the bracket 13. In other words, the wall surface 13a and the wall surface 13b may also be on the same plane.

[0222] In addition to the devices dedicated to printing, the liquid ejection device 1A exemplified in the foregoing manner can also be applied to various devices such as a facsimile device or a copying machine. Of course, the use of the liquid ejection device 1A is not limited to printing. For example, a liquid ejection device that ejects a solution of a color material is used as a manufacturing device for forming a color filter of a display device such as a liquid crystal display panel. In addition, a liquid ejection device that ejects a solution of a conductive material is used as a manufacturing device for forming wirings or electrodes of a wiring substrate. In addition, a liquid ejection device that ejects a solution of an organism-related organic substance is used, for example, as a manufacturing device for manufacturing a biochip.

[0223] Explanation of symbols

[0224] 1A, 1B, 1C... liquid ejection devices; 2... liquid container (liquid storage part), 10, 10A, 10B, 10C, 10D, 10E... liquid ejection heads; 20... head chip; 21A... head chip (first head chip); 22A... head chip (second head chip); 23... nozzle plate; 30... ejection surface; 35... edge part (first edge part of the ejection surface); 37... edge part (second edge part of the ejection surface); 41... flange part; 45... positioning part (first positioning part); 46... positioning part (second positioning part); 50... line head; 50A... line head (first line head); 50B... line head (second line head); 53... head holding member (holding member); 61 to 64... screw holes (fixing parts); 110... electrical connection part; 120... imaginary parallelogram; 121... imaginary side (first imaginary side); 122... imaginary side (second imaginary side); 123... imaginary side (third imaginary side); 124... imaginary side (fourth imaginary side); 131... acute angle part (first acute angle part); 133... obtuse angle part (first obtuse angle part); 150... outer shape of the liquid ejection head; DM... conveyance direction of the medium; N... nozzle; PP... medium; H... range; V... V direction (first direction); U... U direction (second direction); X... X-axis direction (third direction); Y... Y-axis direction (fourth direction); Z... Z-axis direction (normal direction of the ejection surface).

Claims

1. A liquid ejection head includes a plurality of head chips elongated in a first direction and having an ejection surface for ejecting liquid, wherein, inside a hypothetical parallelogram having a first hypothetical side and a second hypothetical side that are along the first direction and in contact with at least one of the plurality of head chips, and a third hypothetical side and a fourth hypothetical side that are along a second direction intersecting the first direction and in contact with at least one of the plurality of head chips, the plurality of head chips are arranged and disposed; the ejection surface has a third edge portion extending along the first direction; when observing the ejection surface in the normal direction of the ejection surface, the ejection surface does not overlap with the acute angle portion of the hypothetical parallelogram; when observing the ejection surface in the normal direction of the ejection surface, the acute angle portion is within a range of 80% of the length of the distance from the vertex of the acute angle portion to the head chip closest to the vertex among the plurality of head chips in the hypothetical parallelogram.

2. The liquid ejection head according to claim 1, wherein, when observing the ejection surface in the normal direction of the ejection surface, the first direction is a direction inclined with respect to the conveyance direction of the medium of the liquid to be ejected.

3. The liquid ejection head according to claim 1 or 2, wherein, the head chip has a nozzle plate provided with a plurality of nozzles; when observing the ejection surface in the normal direction of the ejection surface, the head chip has a rectangular shape.

4. The liquid ejection head according to claim 1, wherein, when observing the ejection surface in the normal direction of the ejection surface, the ejection surface overlaps with the entire regions of the two obtuse angle portions on both sides of the hypothetical parallelogram.

5. The liquid ejection head according to claim 1, wherein, the first hypothetical side is inscribed with only one of the head chips.

6. The liquid ejection head according to claim 1, wherein, the first hypothetical side and the third hypothetical side form a first acute angle portion which is one of the acute angle portions; the plurality of head chips include: a first head chip inscribed with the first hypothetical side at the closest position with respect to the first acute angle portion; a second head chip different from the first head chip and inscribed with the third hypothetical side at the closest position with respect to the first acute angle portion.

7. The liquid ejection head according to claim 1, wherein, the liquid ejection heads are arranged along a third direction to form a line head, when observing the ejection surface in the normal direction of the ejection surface, the first direction is a direction inclined with respect to the third direction.

8. The liquid ejection head according to claim 1, wherein, the liquid ejection head ejects liquid while reciprocatingly moving in a fourth direction as a main scanning direction, when observing the ejection surface in the normal direction of the ejection surface, the first direction is a direction inclined with respect to the fourth direction.

9. The liquid ejection head according to claim 7, wherein, the first hypothetical side and the third hypothetical side form a first acute angle portion which is one of the acute angle portions, The ejection surface has a first edge portion that intersects the first imaginary side and the third imaginary side between the head chip closest to the first acute angle portion and the first acute angle portion in the third direction.

10. The liquid ejection head according to claim 9, wherein the first edge portion extends in a straight line along a fourth direction intersecting the third direction.

11. The liquid ejection head according to claim 10, wherein the ejection surface has a second edge portion that is opposed to the first edge portion in the third direction and extends along the fourth direction, when the ejection surface is viewed from the normal direction of the ejection surface, the second edge portion does not overlap with the imaginary parallelogram.

12. The liquid ejection head according to claim 11, wherein compared with the length of the second edge portion along the fourth direction, the length of the first edge portion along the fourth direction is longer.

13. The liquid ejection head according to any one of claims 9 to 12, wherein when viewed from the third direction, the first edge portion overlaps at least one of the plurality of head chips that does not abut the third imaginary side.

14. The liquid ejection head according to claim 13, wherein when viewed from the third direction, the first edge portion overlaps at least one of the plurality of head chips that abuts the fourth imaginary side.

15. The liquid ejection head according to claim 1, wherein the plurality of head chips are respectively inscribed in the imaginary parallelogram.

16. The liquid ejection head according to claim 1, wherein when the ejection surface is viewed from the normal direction of the ejection surface, the first direction is a direction inclined with respect to the conveyance direction of the medium of the liquid to be ejected, the first imaginary side and the third imaginary side form a first acute angle portion that is one of the acute angle portions, the plurality of head chips include: a first head chip that is inscribed in the first imaginary side at the closest position with respect to the first acute angle portion; a second head chip that is different from the first head chip and is inscribed in the third imaginary side at the closest position with respect to the first acute angle portion, the ejection surface has a first edge portion that intersects the first imaginary side and the third imaginary side between the head chip closest to the first acute angle portion and the first acute angle portion in a third direction orthogonal to the conveyance direction.

17. The liquid ejection head according to claim 16, wherein the plurality of head chips constitute a first chip group in which a part of the plurality of head chips are arranged and configured in the third direction, and a second chip group in which a part of the plurality of head chips are arranged and configured in the third direction, the first chip group and the second chip group are arranged and configured in the conveyance direction.

18. The liquid ejection head according to claim 17, wherein the first chip group and the second chip group substantially overlap when viewed from the conveyance direction.

19. The liquid ejection head according to claim 16, wherein The first edge portion extends in a straight line along a fourth direction intersecting the third direction. The plurality of head chips constitute a first chip group in which a part of the plurality of head chips are arranged and configured in the third direction, and a second chip group in which a part of the plurality of head chips are arranged and configured in the third direction. The first chip group and the second chip group are arranged and configured in the fourth direction.

20. The liquid ejection head according to claim 1, wherein when observing the ejection surface in the normal direction of the ejection surface, the first direction is a direction inclined with respect to the conveyance direction of the medium of the liquid to be ejected. The plurality of head chips constitute a first chip group in which a part of the plurality of head chips are arranged and configured in a third direction orthogonal to the conveyance direction, and a second chip group in which a part of the plurality of head chips are arranged and configured in the third direction. The first chip group and the second chip group are arranged and configured in the conveyance direction. The first imaginary side and the third imaginary side constitute a first acute angle portion which is one of the acute angle portions. The ejection surface has a first edge portion, and the first edge portion is arranged between the head chip closest to the first acute angle portion and the first acute angle portion in the third direction.

21. The liquid ejection head according to claim 20, wherein the first chip group and the second chip group substantially overlap when observed from the conveyance direction.

22. The liquid ejection head according to claim 21, wherein the first edge portion and the third edge portion are in contact with each other.

23. A liquid ejection head, which includes a plurality of head chips that are long and narrow in a first direction and has an ejection surface for ejecting liquid, wherein inside a hypothetical parallelogram having a first imaginary side and a second imaginary side that are along the first direction and in contact with at least one of the plurality of head chips, and a third imaginary side and a fourth imaginary side that are along a second direction intersecting the first direction and in contact with at least one of the plurality of head chips, the plurality of head chips are arranged. when observing the ejection surface in the normal direction of the ejection surface, the first direction is a direction inclined with respect to the conveyance direction of the medium of the liquid to be ejected. The ejection surface has a third edge portion that extends along the first direction. when observing the ejection surface in the normal direction of the ejection surface, the ejection surface does not overlap with the acute angle portion of the hypothetical parallelogram. The first imaginary side and the third imaginary side constitute a first acute angle portion which is one of the acute angle portions. The plurality of head chips include: a first head chip that is inscribed in the first imaginary side at the closest position to the first acute angle portion. a second head chip that is different from the first head chip and is inscribed in the third imaginary side at the closest position to the first acute angle portion. The ejection surface has a first edge portion that intersects the first imaginary side and the third imaginary side between the head chip closest to the first acute angle portion and the first acute angle portion in a third direction orthogonal to the conveyance direction.

24. A liquid ejection device comprising: a liquid ejection head according to any one of claims 1 to 23; and a liquid reservoir that stores the liquid supplied to the liquid ejection head.

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