Liquid ejecting head and liquid ejecting apparatus

Abstract

To provide a liquid ejecting head and a liquid ejecting apparatus in which a cover can be used in common in accordance with the specification of the liquid ejecting head.SOLUTION: The liquid jet head includes a liquid jetting part Hc for jetting a liquid, a flow channel member 150 communicating with the liquid jetting part Hc, a relay substrate 160 electrically connected to the liquid jetting part Hc, and a cover 170 which houses at least one of the flow channel member 150 and the relay substrate 160 inside and can expand and contract in a height direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head and a liquid ejection apparatus that eject liquid from nozzles, and more particularly to an ink jet recording head and an ink jet recording apparatus that eject ink as the liquid. [Background technology]

[0002] Liquid ejection devices, typified by inkjet recording devices such as inkjet printers and plotters, are equipped with a liquid ejection head capable of ejecting liquid such as ink stored in a cartridge, a tank, etc. Some such liquid ejection heads include a liquid ejection unit that ejects the liquid, a base member that houses the liquid ejection unit, a flow path member that communicates with the liquid ejection unit, an interconnection board that is electrically connected to the liquid ejection unit, and a cover that houses the flow path member and the interconnection board between the base member and the cover (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-92733 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the height of the components housed inside the cover changes depending on the specifications of the liquid jet head, the number of components housed changes, the arrangement of the components housed inside changes, etc., and the height of the cover required to house the components inside changes, it is necessary to prepare different covers for each specification, which causes problems such as complicated cover management, high costs, and an increased environmental load. [Means for solving the problem]

[0005] An aspect of the present invention that solves the above problem is a liquid jet head comprising: a liquid jet unit that jets liquid; a flow path member that communicates with the liquid jet unit; a relay board that is electrically connected to the liquid jet unit; and a cover that houses at least one of the flow path member and the relay board and is expandable and contractible in the vertical direction.

[0006] Another aspect is a liquid ejection apparatus including the liquid ejection head according to the above aspect, and a liquid storage section that stores liquid to be supplied to the liquid ejection head. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic configuration diagram of a liquid ejecting device according to a first embodiment. [Figure 2] 1 is an exploded perspective view of a liquid jet head according to a first embodiment. [Figure 3] 1 is a plan view of a liquid jet head according to a first embodiment. [Figure 4] 1 is a cross-sectional view of a liquid jet head according to a first embodiment. [Figure 5] 1 is a cross-sectional view of a liquid jet head according to a first embodiment. [Figure 6] 1 is an enlarged cross-sectional view of a main part of a liquid jet head according to a first embodiment. [Figure 7] 1 is an enlarged cross-sectional view of a main part of a liquid jet head according to a first embodiment. [Figure 8] 1 is an enlarged cross-sectional view of a main part of a liquid jet head according to a first embodiment. [Figure 9] FIG. 10 is an enlarged cross-sectional view of a main part of a liquid jet head according to a second embodiment. [Figure 10] FIG. 10 is an enlarged cross-sectional view of a main part of a liquid jet head according to a second embodiment. [Figure 11] FIG. 10 is an enlarged cross-sectional view of a main part of a liquid jet head according to a third embodiment. [Figure 12] FIG. 10 is an enlarged cross-sectional view of a main part of a liquid jet head according to a third embodiment. [Figure 13] FIG. 11 is an enlarged cross-sectional view of a main portion of a modified example of the liquid jet head according to the third embodiment. [Figure 14] FIG. 11 is an enlarged cross-sectional view of a main portion of a modified example of the liquid jet head according to the third embodiment. [Figure 15] FIG. 11 is an enlarged cross-sectional view of a main portion of a modified example of the liquid jet head according to the third embodiment. [Figure 16] FIG. 10 is an enlarged cross-sectional view of a main part of a liquid jet head according to another embodiment. [Figure 17] FIG. 10 is an enlarged cross-sectional view of a main part of a liquid jet head according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will be described in detail below based on embodiments. However, the following description illustrates one aspect of the present invention and can be modified as desired within the scope of the present invention. In each drawing, the same reference numerals indicate the same components, and their description will be omitted as appropriate. In each drawing, X, Y, and Z represent three spatial axes that are orthogonal to each other. In this specification, the directions along these axes are referred to as the X direction, Y direction, and Z direction. In each drawing, the direction indicated by the arrow is the positive (+) direction, and the direction opposite the arrow is the negative (-) direction. The Z direction indicates the vertical direction, the +Z direction indicates a vertically downward direction, and the -Z direction indicates a vertically upward direction. The -Z direction is an example of a "height direction." Furthermore, the directions of the three spatial axes, which are not limited to positive and negative directions, will be described as the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0009] (Embodiment 1) FIG. 1 is a diagram showing a schematic configuration of a liquid ejecting apparatus 1 of the present invention.

[0010] As shown in the figure, the liquid ejection device 1 is a so-called serial printer that includes a liquid ejection head H and prints by conveying a medium S in the X-axis direction while moving the liquid ejection head H back and forth in the Y-axis direction and ejecting (also called discharging) liquid from the liquid ejection head H toward the medium S in the +Z direction. Note that the medium S can be made of any material, such as recording paper, resin film, cloth, etc.

[0011] The liquid ejecting device 1 includes a liquid ejecting head H, a liquid storage unit 3, a control unit 4, a transport mechanism 5 that feeds out the medium S, and a moving mechanism 6.

[0012] The liquid jet head H jets the liquid supplied from the liquid storage section 3 in the form of droplets in the +Z direction.

[0013] The liquid storage unit 3 individually stores multiple types of ink with different colors and ingredients to be ejected from the liquid ejection head H. Examples of the liquid storage unit 3 include a cartridge that is detachable from the liquid ejection device 1, a bag-shaped ink pack made of flexible film, and an ink tank that can be refilled with ink. FIG. 1 illustrates a single liquid storage unit 3. The liquid storage unit 3 may be a liquid storage unit 3 having separate chambers that individually store multiple types of ink, or may be multiple liquid storage units 3 that are individually provided corresponding to the multiple types of ink. The liquid storage unit 3 may also be divided into a main tank and a sub-tank. A configuration may be adopted in which the sub-tank is connected to the liquid ejection head H, and ink consumed when ink is ejected from the liquid ejection head H is replenished from the main tank to the sub-tank.

[0014] A supply tube Tin and a discharge tube Tout are connected to the liquid storage unit 3. Although one supply tube Tin and one discharge tube Tout are illustrated in Fig. 1, a supply tube Tin and a discharge tube Tout are provided for each different type of ink.

[0015] The supply tube Tin is a tube that supplies ink in the liquid storage unit 3, which has been pressurized to a predetermined pressure by the pump 7, to the liquid jet head H. The discharge tube Tout is a tube that recovers ink from the liquid jet head H into the liquid storage unit 3.

[0016] The control unit 4 includes, for example, a control device such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage device such as a semiconductor memory. The control unit 4 also includes a power supply device that supplies power from an external power source such as a commercial power source to each element of the liquid ejection device 1. The control unit 4 is electrically connected to the liquid ejection head H via external wiring (not shown). The control unit 4 comprehensively controls each element of the liquid ejection device 1 by the control device executing a program stored in the storage device.

[0017] The transport mechanism 5 transports the medium S in the X-axis direction, and includes, for example, a transport roller 5a that is rotated by a transport motor that is driven under the control of the control unit 4.

[0018] The movement mechanism 6 is a mechanism for reciprocating the liquid jet head H in the Y-axis direction, and includes a holder 6a that holds the liquid jet head H, and a conveyor belt 6b that is an endless belt that is installed along the Y-axis direction. The control unit 4 controls the driving of a conveyor motor (not shown), thereby rotating the conveyor belt 6b, and moves the liquid jet head H back and forth in the Y-axis direction together with the holder 6a fixed to the conveyor belt 6b. Note that the liquid storage unit 3 can also be mounted on the holder 6a together with the liquid jet head H. The holder 6a holds one liquid jet head H, but the holder 6a may hold two or more liquid jet heads H.

[0019] The liquid jet head H performs a jetting operation in which ink supplied from the liquid storage unit 3 is jetted as ink droplets in the +Z direction from each of the multiple nozzles N (see FIG. 3) under the control of the control unit 4. The control unit 4 functions as a jetting control unit that controls the jetting of ink by the liquid jet head H. This jetting operation by the liquid jet head H is performed in parallel with the transport of the medium S in the X-axis direction by the transport mechanism 5 and the reciprocating movement of the liquid jet head H in the Y-axis direction by the movement mechanism 6, thereby applying ink to the medium S, i.e., performing so-called printing.

[0020] FIG. 2 is an exploded perspective view of the liquid jet head H according to the first embodiment. FIG. 3 is a plan view of the liquid jet head H as viewed in the -Z direction. FIG. 4 is a cross-sectional view of a main portion taken along line AA' in FIG. 3. FIG. 5 is a cross-sectional view of a main portion taken along line BB' in FIG. 3. FIG. 6 is an enlarged cross-sectional view of a main portion of the liquid jet head H, illustrating a second position. FIG. 7 is an enlarged cross-sectional view of a main portion of the liquid jet head H, illustrating a first position. Note that the directions of the liquid jet head H will be described based on the directions when it is mounted on the liquid jet device 1, i.e., the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0021] As shown in the figure, the liquid jet head H includes a plurality of head chips Hc each having a nozzle N for ejecting ink droplets, a base member 130, a fixing plate 140, a flow path member 150, a relay substrate 160, and a cover 170.

[0022] The head chip Hc is an example of a "liquid ejecting unit" and has a plurality of nozzles N that eject ink droplets as a liquid on a surface facing the +Z direction, which is opposite to the surface fixed to the base member 130. The plurality of nozzles N are arranged in a line along the X-axis direction to form a nozzle row. In this embodiment, two nozzle rows are provided spaced apart in the Y-axis direction.

[0023] Inside such a head chip Hc (not shown), there are provided a flow path communicating with the nozzle N and a pressure generating means for generating a pressure change in the ink in the flow path. The pressure generating means may be, for example, a means that changes the volume of the flow path by deforming a piezoelectric actuator having a piezoelectric material that exhibits electromechanical conversion function, thereby generating a pressure change in the ink in the flow path and ejecting ink droplets from the nozzle N. Other pressure generating means that may be used include a means that has a heating element disposed in the flow path, and ejects ink droplets from the nozzle N by bubbles generated by the heat generated by the heating element, or a so-called electrostatic actuator that generates an electrostatic force between a vibration plate and an electrode, which deforms the vibration plate using the electrostatic force and ejects ink droplets from the nozzle N.

[0024] A wiring substrate 110 electrically connected to the internal pressure generating means is drawn out from the surface of the head chip Hc facing the -Z direction. The wiring substrate 110 is a flexible substrate, such as a COF (Chip On Film), an FFC (Flexible Flat Cable), or an FPC (Flexible Printed Circuits).

[0025] Base member 130 has accommodation portion 131 having a recessed shape that opens on a surface facing the +Z direction. Furthermore, fixing plate 140 is fixed to the surface of base member 130 facing the +Z direction. Accommodation portion 131 of base member 130 accommodates multiple head chips Hc fixed to fixing plate 140. The opening of accommodation portion 131 is partially sealed by fixing plate 140. In other words, head chips Hc are accommodated in a space defined by accommodation portion 131 and fixing plate 140. Accommodation portion 131 may be provided for each head chip Hc, or may be provided continuously across multiple head chips Hc. In this embodiment, accommodation portion 131 is provided for each head chip Hc.

[0026] The head chips Hc are arranged in a staggered pattern along the X-axis direction on such base member 130. The number of head chips Hc held by base member 130 is not limited to four, and may be one, or two or more.

[0027] The fixed plate 140 is formed of a plate-like member such as a metal, such as stainless steel. The fixed plate 140 has an exposure opening 141 that exposes, in the +Z direction, the nozzle surface of each head chip Hc, on which multiple nozzles N are formed. In this embodiment, an exposure opening 141 is provided independently for each head chip Hc. The fixed plate 140 is fixed to the surface of the base member 130 facing the +Z direction so as to close the opening of the accommodation portion 131.

[0028] The base member 130 also has a plurality of communicating paths 34 that allow ink to flow between the head chip Hc and the flow path member 150. One end of each communicating path 34 opens to the bottom surface of the storage section 131, i.e., the surface of the storage section 131 facing the -Z direction, and communicates with the flow path of the head chip Hc. In this embodiment, four communicating paths 34 are provided for each head chip Hc. The other end of each communicating path 34 opens to the surface of the base member 130 facing the -Z direction, and communicates with the flow path of the flow path member 150, which will be described in detail later. Inside the head chip Hc, a supply path through which ink is supplied for each nozzle row and a discharge path through which ink not ejected from the nozzles N is discharged are provided. Therefore, a total of four flow paths are provided that communicate with the communicating paths 34 of the head chip Hc. Of course, the flow paths may branch within the head chip Hc. Therefore, the number of communicating paths 34 is not particularly limited to this and may be one or two. It is also possible that the base member 130 is not provided with the communication passage 34, and the flow passage of the flow passage member 150 and the flow passage of the head chip Hc are directly connected.

[0029] Further, the base member 130 is provided with wiring insertion holes 39 for inserting the wiring substrates 110 of the head chips Hc for each accommodation section 131. The wiring insertion holes 39 are provided so as to open to the bottom surface of the accommodation section 131, i.e., the surface on the −Z direction side within the accommodation section 131, and also to open to the surface of the base member 130 on the −Z direction side.

[0030] The flow path member 150 is fixed to a surface of the base member 130 facing the -Z direction. The flow path member 150 is composed of multiple components stacked in the Z-axis direction, six components in this embodiment. Inside the flow path member 150 (not shown), there are provided flow paths that supply ink to each head chip Hc and flow paths that discharge ink from each head chip Hc. In other words, the flow path member 150 is a member having flow paths that communicate with the flow paths of multiple head chips Hc. Furthermore, on the surface of the flow path member 150 facing the -Z direction, there are provided four flow path connectors 151 that communicate with the internal flow paths. The flow path connectors 151 are an example of "flow path pipes" and have a cylindrical shape that protrudes toward the +Z direction. A tube is connected to each of the flow path connectors 151, or the tube can be removed. Ink from the liquid storage portion 3 is supplied from the flow path connection portion 151 via the supply tube Tin, and ink from the liquid jet head H is collected into the liquid storage portion 3 via the discharge tube Tout, so-called circulation is performed.

[0031] As shown in FIGS. 2 and 4, the relay board 160 includes a first relay board 161, a second relay board 162, and a third relay board 163 that connects the first relay board 161 and the second relay board 162 together.

[0032] The first relay substrate 161 is made of a hard, rigid substrate with no flexibility, and has wiring, electronic components, and the like (not shown) mounted thereon. In this embodiment, as an example of an electronic component, an external connector 164 is illustrated, to which external wiring (not shown) provided outside the liquid jet head H is connected. The first relay substrate 161 is fixed to a surface of the flow path member 150 facing the -Z direction.

[0033] The second relay board 162 is made of a hard, rigid board with no flexibility, and is provided with wiring, electronic components, etc. (not shown). The second relay board 162 is connected to the wiring board 110 of the head chip Hc.

[0034] The second relay substrates 162 are fixed to both side surfaces of the flow path member 150 in the Y-axis direction. That is, one liquid jet head H has two second relay substrates 162. The second relay substrate 162 arranged in the +Y direction of the flow path member 150 is commonly connected to the wiring substrates 110 of two head chips Hc located in the +Y direction. Furthermore, the second relay substrate 162 arranged in the -Y direction of the flow path member 150 is commonly connected to the wiring substrates 110 of two head chips Hc located in the -Y direction.

[0035] The first relay board 161 and the two second relay boards 162 are connected via a third relay board 163. The third relay board 163 is made of, for example, a flexible wiring board having flexibility.

[0036] Drive signals, head control signals, and the like for controlling the head chips Hc are input from external wiring to first relay board 161 via external connector 164. The various signals input to first relay board 161 are input to two second relay boards 162 via third relay board 163, and then input to each head chip Hc from second relay board 162. In other words, relay board 160 is a member to which multiple head chips Hc are electrically connected.

[0037] As shown in FIGS. 5 to 7 , the cover 170 is fixed to the surface of the base member 130 facing the −Z direction and houses the flow path member 150 and the relay substrate 160 therein. The cover 170 protects the components housed therein, such as the flow path member 150 and the relay substrate 160 in this embodiment, from external environments, such as mist-like ink generated during ejection, high or low temperatures, and high humidity, thereby improving gas barrier properties. It also protects the components from external impacts and pressure when gripped, and is therefore required to have sufficient rigidity to withstand the external environment and external impacts and stresses. In this embodiment, the cover 170 is primarily made of resin, but may be partially or entirely made of metal. The cover 170 of this embodiment houses both the flow path member 150 and the relay substrate 160 therein. However, it is sufficient to house at least one of the flow path member 150 and the relay substrate 160 therein.

[0038] The cover 170 is extendable in the Z-axis direction. Specifically, the cover 170 includes a first member 180 and a second member 190.

[0039] The first member 180 includes a first peripheral wall portion 181 that is annular when viewed in the Z-axis direction, and a bottom wall portion 182 that closes the opening of the first peripheral wall portion in the -Z direction. The first member 180 has a recess 183 that opens on a surface facing the +Z direction defined by the first peripheral wall portion 181 and the bottom wall portion 182.

[0040] The second member 190 includes a second peripheral wall portion 191 that is annular when viewed in the Z-axis direction. The second member 190 has a first through portion 192 that is a through hole that penetrates the second member 190 along the Z-axis direction defined by the second peripheral wall portion 191.

[0041] The second member 190 also has flange portions 193 at its end in the +Z direction that protrude in the +X direction and the -X direction. Each of the flange portions 193 is provided with a first cover fixing hole 194 that penetrates in the Z-axis direction, and the second member 190 has male cover fixing screws 195 that are inserted into the first cover fixing holes 194 of the flange portions 193 and screwed into second cover fixing holes 138 that are provided in the base member 130 and have female threads, thereby detachably fixing the cover 170 to the base member 130. Note that the method of fixing the cover 170 to the base member 130 is not limited to fixing with screws, and may be, for example, fixing by clamping the cover 170 and the base member 130 together using a clamp or the like, fixing by the elastic force of a spring, or the like. However, the cover 170 is fixed to the base member 130 with a fixing structure that allows it to be easily attached and detached, so that the cover 170 can be easily attached and detached from the base member 130 when changing the specifications of the liquid ejection head H, as will be described in detail later.

[0042] The recess 183 of the first member 180 is slightly larger than the second circumferential wall portion 191 of the second member 190 when viewed in the Z-axis direction, so that the second circumferential wall portion 191 of the second member 190 can be inserted into the recess 183 of the first member 180. In other words, the first member 180 is disposed outside the second member 190, and the second member 190 is disposed inside the first member 180. Note that the relationship of "inside" and "outside" between the first member 180 and the second member 190 referred to here refers to the positional relationship between the first circumferential wall portion 181 and the second circumferential wall portion 191 when viewed in the Z-axis direction. With the second circumferential wall portion 191 of the second member 190 inserted into the recess 183 of the first member 180 in this way, the first member 180 is movable in the Z-axis direction relative to the second member 190. That is, the inner peripheral surface of the first peripheral wall portion 181 is guided by the outer peripheral surface of the second peripheral wall portion 191, so that the first member 180 can move in the Z axis direction along the outer peripheral surface of the second peripheral wall portion 191 of the second member 190. The position of the cover 170 in the Z axis direction relative to the second member 190 can be adjusted, so that the cover 170 can expand and contract in the Z axis direction. In this embodiment, the position of the first member 180 in the Z axis direction relative to the second member 190 can be moved between a first position shown in FIG. 7 and a second position shown in FIG. 6. The position of the first member 180 in the Z axis direction relative to the second member 190 at the second position is located in the negative Z direction relative to the position of the first member 180 in the Z axis direction relative to the second member 190 at the first position. That is, the dimension L2 in the Z axis direction of the cover 170 at the second position is greater than the dimension L1 in the Z axis direction of the cover 170 at the first position. That is, the relationship L2>L1 is satisfied. Incidentally, the above-described flow path member 150 is accommodated within the cover 170 at the second position. In contrast to this, a flow path member 150A, which is different from the above-described flow path member 150, is accommodated within the cover 170 at the first position. Here, the fact that the flow path member 150 and the flow path member 150A are different means that, for example, the number of layers of the flow path members 150 and 150A in the Z-axis direction or the number of parts of the flow path members 150 and 150A are different. In this embodiment, the flow path member 150 is composed of six members stacked in the Z-axis direction, and the flow path member 150A is composed of three members stacked in the Z-axis direction. Incidentally, the flow path member 150 and the flow path member 150A differ in the number of internal flow paths and the number of flow path connecting portions 151.For example, flow path member 150A has two flow path connecting portions 151, one at each end in the X-axis direction. Factors that may change the height in the Z-axis direction of the internal components housed in cover 170 include factors other than the number of layers of components constituting flow path member 150. Examples of other factors include when the thickness of each component is different even if the number of layers of components constituting flow path member 150 is the same. Examples of other factors include when the dimension in the Z-axis direction of first relay board 161 varies depending on the number of layers in the Z-axis direction of first relay board 161 housed inside cover 170 other than flow path member 150, or the arrangement of first relay board 161. For example, whether the mounting surface of electronic components on first relay board 161 is arranged along an XY plane defined by the X-axis and Y-axis as in this embodiment, or whether the mounting surface is arranged along the Z-axis, etc. Another factor is the presence of an intermediate member between the flow path member 150 and the base member 130 within the cover 170, such as a member having a pressure adjustment valve that opens when the downstream flow path becomes negative pressure, a member having a filter that captures foreign matter such as air bubbles contained in the ink, or a member provided with a heater that heats the ink in the flow path. Incidentally, the dimension of the cover 170 in the Z-axis direction needs to be expanded or contracted by accommodating other members within the cover 170. Incidentally, the connection portion connecting the flow path member 150 to the base member 130 and the connection portion connecting the flow path member 150A to the base member 130 share a common structure. Furthermore, the connection portion of the intermediate member with the base member 130 shares a common structure with the connection portions of the flow path members 150 and 150A, and the connection portions between the intermediate member and the flow path member 150 and the flow path member 150A also share a common structure. This makes it easy to replace the flow path member 150 with the flow path member 150A and to provide an intermediate member in accordance with the specifications of the liquid jet head H.

[0043] The cover 170 has a fixing means capable of fixing the first member 180 to prevent it from moving relative to the second member 190 at each of the first and second positions. In this embodiment, the fixing means includes a male thread 200 and a female thread 201 formed on the second member 190 and capable of threadably engaging with the male thread 200. That is, the first member 180 and the second member 190 are fixed to each other by so-called screw fixing. Specifically, the second peripheral wall portion 191 of the second member 190 is provided with a female thread 201 having a concave shape that opens on the outer peripheral surface but not on the inner peripheral surface. That is, the female thread 201 has a threaded hole with a helical thread groove provided along the inner peripheral surface of the concave portion that opens on the outer peripheral surface of the second peripheral wall portion 191. The female thread 201 has a first female thread 201A and a second female thread 201B that is positioned in the -Z direction relative to the first female thread 201A. The first female screw 201A and the second female screw 201B are positioned so as to overlap when viewed in the Z-axis direction. As a result, when the first member 180 moves relative to the second member 190 in the Z-axis direction, the first through-hole 184 provided in the first member 180 and through which the male screw 200 is inserted can be used in common for both the first male screw 201A and the second female screw 201B. Therefore, by providing multiple through-holes, it is possible to prevent the first member 180 from having a through-hole that is not blocked by the male screw 200, thereby preventing ink from entering the inside of the cover 170 through a through-hole that is not blocked by the male screw 200. Hereinafter, when there is no need to distinguish between the first female screw 201A and the second female screw 201B, they will be referred to as female screws 201. Incidentally, two sets of the first female screw 201A and the second female screw 201B are provided, one set at each end of the cover 170 in the X-axis direction. Of course, the number of pairs of the first female thread 201A and the second female thread 201B is not particularly limited, and may be one pair, or three or more pairs.

[0044] The first through-holes 184 penetrate the first circumferential wall portion 181 in the thickness direction. Two first through-holes 184 are provided in total, one at each end of the first member 180 in the X-axis direction.

[0045] 7, the male screw 200 inserted through the first through-hole 184 of the first member 180 is screwed into the first female screw 201A, thereby positioning and fixing the first member 180 and the second member 190 at the first position. At this time, the male screw 200 is not screwed into the second female screw 201B.

[0046] 6, the first member 180 and the second member 190 are positioned and fixed at the second position by threading the male screw 200, which is inserted through the same first through-hole 184, into the second female screw 201B. At this time, the male screw 200 is not threaded into the first female screw 201A. Therefore, the first female screw 201A is not covered by the first member 180 and is exposed to the outside. However, because the first female screw 201A has a concave shape that does not penetrate the second circumferential wall portion 191 in the thickness direction, even if the screw hole of the first female screw 201A is exposed to the outside, it is possible to prevent ink adhering to the outside of the cover 170 or mist-like ink from entering the inside of the cover 170 via the first female screw 201A.

[0047] Such a fixing means using the male screw 200 and the female screw 201 can release the fixed state between the first member 180 and the second member 190 by releasing the engagement between the male screw 200 and the female screw 201. Therefore, the male screw 200 and the female screw 201 of this embodiment also function as a "releasing means."

[0048] As described above, by making the cover 170 expandable in the Z-axis direction, the cover 170 can be expanded or contracted in the Z-axis direction to match the specifications of the liquid jet head H, that is, to match changes in the configuration and arrangement of the internal components housed within the cover 170, thereby making the cover 170 standardizable. In other words, there is no need to prepare multiple types of covers with different dimensions in the Z-axis direction to match the specifications of the internal components housed in the cover 170. Therefore, even if the specifications of the liquid jet head H are changed not only at the time of shipment from the factory but also at the customer's site that provides the liquid jet head H, there is no need for the customer to store multiple covers with different dimensions in the Z-axis direction, and there is no need to supply multiple covers with different dimensions in the Z-axis direction to the customer, thereby reducing the environmental impact.

[0049] The first member 180 of the cover 170 has an electrical connection opening 185 that penetrates the bottom wall portion 182 in the Z-axis direction. The external connector 164 of the relay board 160 housed inside the cover 170 is led out to the outside of the surface facing the -Z direction through the electrical connection opening 185.

[0050] The first member 180 also has four flow path connection openings 186 that penetrate the bottom wall portion 182 in the Z-axis direction. The flow path connection portions 151 of the flow path member 150 housed inside the cover 170 are inserted into the flow path connection openings 186, and their tips are led out to the outside of the surface facing the -Z direction. As shown in Fig. 8, the flow path connection openings 186 also have a first seal member 210 and a second seal member 220 inside. The first seal member 210 and the second seal member 220 are formed of an elastic material such as an elastomer.

[0051] The second seal member 220 is disposed in the flow path connecting opening 186 in the −Z direction relative to the first seal member 210. In other words, the second seal member 220 is disposed closer to the outer surface of the cover 170 in the Z axis direction than the first seal member 210.

[0052] The first seal member 210 has an annular shape and is provided with a flow path connection portion insertion hole 211 that penetrates along the Z-axis direction. The flow path connection portion insertion hole 211 has an inner diameter that is slightly smaller than the outer diameter of the flow path connection portion 151. In an inserted state in which the flow path connection portion 151 is inserted into the flow path connection opening 186, the flow path connection portion 151 is inserted into the flow path connection portion insertion hole 211 of the first seal member 210 and blocks the gap between the outer peripheral surface of the flow path connection portion 151 and the inner peripheral surface of the flow path connection opening 186. In an uninserted state in which the flow path connection portion 151 is not inserted into the flow path connection opening 186, the first seal member 210 does not block the flow path connection opening 186 because the flow path connection portion insertion hole 211 remains open.

[0053] The second seal member 220 has a disk shape with multiple slits 221 penetrating the second seal member 220 in the Z-axis direction. The slits 221 are arranged radially from the center of the second seal member 220 as viewed in the Z-axis direction. That is, the multiple slits 221 define multiple triangular protrusions 222 in the circumferential direction of the second seal member 220 from the periphery toward the center as viewed in the Z-axis direction. The second seal member 220 closes the flow path connection opening 186 in an uninserted state in which the flow path connection portion 151 is not inserted into the flow path connection opening 186. That is, in the uninserted state, the multiple protrusions 222 abut against each other, thereby not opening the slits 221. Furthermore, in an inserted state in which the flow path connection portion 151 is inserted into the flow path connection opening 186, the protrusions 222 elastically deform to widen the slits 221, thereby allowing the flow path connection portion 151 to be inserted therein.

[0054] By providing the first seal member 210 in this manner, even if ink drips when connecting or disconnecting the flow path connecting portion 151 and the tube in an inserted state in which the flow path connecting portion 151 is inserted into the flow path connecting opening 186, it is possible to prevent the ink from entering the inside of the cover 170. Therefore, the first seal member 210 can prevent ink that has entered the cover 170 from adhering to the relay board 160 or the like, and can prevent short circuits in the wiring, failures of mounted electronic components, and the like.

[0055] 8, even when the flow path connecting portion 151 is not inserted into the flow path connecting opening 186, the second sealing member 220 closes the flow path connecting opening 186, thereby preventing ink dripping when the flow path connecting portion 151 is connected to or disconnected from the tube, and mist-like ink generated when ink is ejected from the nozzle N, from entering the inside of the cover 170. Therefore, one cover 170 can be used for flow path members 150, 150A having different numbers of flow path connecting portions 151.

[0056] Furthermore, by positioning the second sealing member 220 closer to the outer surface of the cover 170 in the Z-axis direction than the first sealing member 210, ink can be prevented from entering the inside of the first sealing member 210 when the second sealing member 220 is not inserted, and ink adhering to the first sealing member 210 can be prevented from entering the inside of the cover 170 when the second sealing member 220 is inserted.

[0057] In this embodiment, both the first seal member 210 and the second seal member 220 are provided in each flow path connecting opening 186, but only one of them may be provided.

[0058] 7 and 8, the flow path connection opening 186 into which the flow path connection part 151 is inserted is an example of a "first opening," and the flow path connection opening 186 into which the flow path connection part 151 is not inserted is an example of a "second opening." In other words, the liquid jet head H shown in FIGS. 7 and 8 is equipped with both a first opening and a second opening.

[0059] In the present embodiment, two female threads 201, a first female thread 201A and a second female thread 201B, are provided. The position of the first member 180 when the first female thread 201A is threadedly engaged with the male thread 200 is referred to as the first position, and the position of the first member 180 when the second female thread 201B is threadedly engaged with the male thread 200 is referred to as the second position. However, this is not particularly limited. For example, three female threads 201 may be provided, each positioned at a different position in the Z-axis direction. For example, a third female thread may be provided that is positioned further in the −Z direction than the second female thread 201B. The position of the first member 180 relative to the second member 190 when the third female thread is threadedly engaged with the male thread 200 is referred to as the third position. In other words, the cover 170 can fix the first member 180 and the second member 190 by threading the male thread 200 with the third female thread at the third position. The dimension in the Z axis direction of the cover 170 when the first member 180 is located at the third position is larger than the dimension L2 in the Z axis direction of the cover 170 when the first member 180 is located at the second position. In this way, by making the cover 170 extendable and retractable in three stages in the Z axis direction, the cover 170 can accommodate various changes in specifications of the liquid jet head H. Note that the number of stages in which the cover 170 can extend and retract in the Z axis direction and be fixed is not limited to three stages, and may be four stages or more.

[0060] Furthermore, in the present embodiment, the first member 180 and the second member 190 are arranged so that the first member 180 is on the outside and the second member 190 is on the inside, but this is not particularly limited, and the first member 180 may be arranged so that the first member 180 is on the inside and the second member 190 is on the outside. In this case, the first through hole 184 is formed in the second circumferential wall portion 191 of the second member 190, and the female thread 201 is formed in the first circumferential wall portion 181 of the first member 180. However, when the first member 180 is arranged inside the second member 190, a gap between the first circumferential wall portion 181 of the first member 180 and the second circumferential wall portion 191 of the second member 190 opens in the −Z direction. Furthermore, ink leaking when the flow path connecting portion 151 and the tube are attached or detached tends to adhere to the surface of the bottom wall portion 182 of the first member 180 facing the -Z direction, and the ink attached to the bottom wall portion 182 of the first member 180 tends to flow along the outer peripheral surface of the first circumferential wall portion 181 and enter the inside of the cover 170 through a gap between the first member 180 and the second member 190. By disposing the first member 180 on the outside of the second member 190 as in the present embodiment, the gap between the first circumferential wall portion 181 and the second circumferential wall portion 191 opens in the +Z direction. Therefore, even if ink attached to the bottom wall portion 182 drips down along the outer peripheral surface of the first circumferential wall portion 181, the ink is less likely to enter the inside of the cover 170 through this gap. Of course, such an effect is effective when the liquid ejection head H is disposed so that the +Z direction is oriented downward due to gravity.

[0061] (Embodiment 2) Fig. 9 is a cross-sectional view of a main part of a liquid jet head H according to a second embodiment of the present invention, showing a second position. Fig. 10 is a cross-sectional view of a main part of a liquid jet head H according to the second embodiment, showing a first position. Note that the same reference numerals are used to designate the same members as those in the above-described embodiments, and redundant explanations will be omitted.

[0062] As shown in Figures 9 and 10, the liquid jet head H of this embodiment, similar to the above-mentioned embodiment 1, comprises a plurality of head chips Hc each provided with a nozzle N for ejecting ink droplets, a base member 130, a fixing plate 140, a flow path member 150, a relay substrate 160, and a cover 170.

[0063] The cover 170 of this embodiment includes a first member 180 and a second member 190. Furthermore, the cover 170 of this embodiment is similar to the above-described first embodiment except that the fixing means for fixing the first member 180 and the second member 190 is different from that of the first embodiment, and therefore a duplicated description will be omitted.

[0064] In this embodiment, the fixing means for fixing the first member 180 and the second member 190 includes a male screw 200 and a nut 202 that is fixed to the second member 190 and into which the male screw 200 is screwed.

[0065] Similar to the first embodiment described above, the first member 180 has first through holes 184 that penetrate the first peripheral wall portion 181 in the thickness direction. Two first through holes 184 are provided in total, one at each end of the first member 180 in the X-axis direction.

[0066] The second member 190 has second through holes 196 that penetrate the second circumferential wall portion 191 in the thickness direction. Two second through holes 196 are provided at overlapping positions when viewed in the Z-axis direction. The second through hole 196 located in the +Z direction is referred to as second through hole 196A, and the second through hole 196 located in the -Z direction is referred to as second through hole 196B. Such second through holes 196 have an inner diameter slightly larger than that of the male thread 200.

[0067] Nuts 202 are fixed to the inner circumferential surface of the second circumferential wall portion 191 at positions corresponding to the second through holes 196. The nuts 202 are female-threaded and have threaded holes with internal thread grooves. The method for fixing the nuts 202 to the second circumferential wall portion 191 is not particularly limited, and examples include adhesion with an adhesive, and welding using heat or ultrasound. In this embodiment, the nut 202 corresponding to the second through hole 196A is referred to as the first nut 202A, and the nut 202 corresponding to the second through hole 196B is referred to as the second nut 202B. Two sets of the two second through holes 196 and two nuts 202 are provided, one at each end of the cover 170 in the X-axis direction.

[0068] 10, the male screw 200 inserted through the first through hole 184 of the first member 180 is inserted through the second through hole 196A of the second member 190 and screwed into the first nut 202A, thereby positioning and fixing the first member 180 and the second member 190 at the first position. At this time, the male screw 200 is not inserted through the second through hole 196B.

[0069] 9, the male screw 200, which has passed through the same first through hole 184, is inserted into the second through hole 196B of the second member 190 and screwed onto the second nut 202B, thereby positioning and fixing the first member 180 and the second member 190 at the second position. At this time, the male screw 200 is not screwed into the second through hole 196A. In this second position, the second through hole 196A is positioned so as to be covered by the first circumferential wall portion 181. As a result, when the first member 180 is fixed to the second member 190 at the second position, the screw hole of the first nut 202A and the second through hole 196A are not exposed to the outside, and ink adhering to the outside of the cover 170 or mist-like ink can be prevented from entering the inside of the cover 170 via the second through hole 196A.

[0070] Although the nut 202 is provided in this embodiment, the present invention is not limited to this. Instead of the nut 202, a spiral thread groove may be provided on the inner peripheral surface of the second through hole 196, and the second through hole 196 of the second peripheral wall portion 191 may be a female-threaded hole. That is, the second through hole 196A may correspond to the "first female thread," and the second through hole 196B may correspond to the "second female thread." Furthermore, the second through hole 196A is an example of the "second through hole A," and the second through hole 196B is an example of the "second through hole B." However, in this embodiment, providing the nut 202 makes it less likely for the thread groove of the nut 202 to be crushed, even when the male screw 200 and the nut 202 are repeatedly attached and detached, thereby improving durability.

[0071] Furthermore, in the present embodiment, nuts 202A and 202B are provided corresponding to second through holes 196A and 196B, respectively, and are fixed to the inner circumferential surface of second member 190, but this is not limiting. By making nut 202 detachable rather than fixed to second member 190, one nut 202 may be used for both second through holes 196A and 196B. In other words, by arranging nut 202 at a position on the inner circumferential surface of second circumferential wall portion 191 corresponding to second through hole 196A, it becomes possible to insert male thread 200 into second through hole 196A to threadably engage with nut 202, and first member 180 can be fixed to second member 190 at the first position. If nut 202 is disposed at a position on the inner circumferential surface of second circumferential wall portion 191 corresponding to second through hole 196B, male screw 200 can be inserted into second through hole 196B to threadably engage with nut 202, thereby fixing first member 180 to second member 190 at the second position. In this case, second through hole 196A is an example of "second through hole A," and second through hole 196B is an example of "second through hole B."

[0072] In this embodiment, when the second member 190 is disposed outside the first member 180, the first through hole 184 is formed in the second member 190, and the second through hole 196 is formed in the first member 180.

[0073] (Embodiment 3) Fig. 11 is a cross-sectional view of a main part of a liquid jet head H according to a third embodiment of the present invention, showing the second position. Fig. 12 is a cross-sectional view of a main part of a liquid jet head H according to the third embodiment, showing the first position. Note that the same reference numerals are used to designate the same members as those in the above-described embodiments, and redundant description will be omitted.

[0074] As shown in Figures 11 and 12, the liquid jet head H of this embodiment, similar to the above-mentioned embodiment 1, comprises a plurality of head chips Hc each having a nozzle N for ejecting ink droplets, a base member 130, a fixing plate 140, a flow path member 150, a relay substrate 160, and a cover 170.

[0075] The cover 170 of this embodiment includes a first member 180 and a second member 190. Furthermore, the cover 170 of this embodiment is similar to the above-described first embodiment except that the fixing means for fixing the first member 180 and the second member 190 is different from those of the first and second embodiments, and therefore a duplicated description will be omitted.

[0076] In this embodiment, the fixing means for fixing the first member 180 and the second member 190 includes a hook 205 provided on the first member 180 and an engaging recess 206 provided on the second member 190.

[0077] Hook 205 is provided at the +Z direction end of first circumferential wall portion 181, protruding inward from the inner circumferential surface of recess 183. The surface of hook 205 facing the -Z direction is engagement surface 205a along the XY plane defined by the X-axis and Y-axis, and the surface of hook 205 facing the +Z direction is inclined surface 205b that is inclined so that the thickness gradually decreases toward the +Z direction.

[0078] The engaging recess 206 has a concave shape that opens to the outer peripheral surface of the second peripheral wall portion 191 of the second member 190. The inner surface of the engaging recess 206 located in the -Z direction is an engaged surface 206a along the XY plane, and the inner surface of the engaging recess 206 located in the +Z direction is an engaged inclined surface 206b that is inclined so that the depth of the engaging recess 206 gradually increases in the +Z direction.

[0079] Three such engagement recesses 206 are provided at different positions in the Z-axis direction. In this embodiment, the three engagement recesses 206 are referred to as a first engagement recess 206A, a second engagement recess 206B, and a third engagement recess 206C in order in the -Z direction. The first engagement recess 206A, the second engagement recess 206B, and the third engagement recess 206C are arranged at positions that overlap one another when viewed in the Z-axis direction. Furthermore, a set of these three engagement recesses 206 is provided at each end of the second member 190 in the X-axis direction.

[0080] When engaging surface 205a of hook 205 catches on engaged surface 206a of engaging recess 206, movement of first member 180 in the -Z direction relative to second member 190 is restricted. Furthermore, when inclined surface 205b of hook 205 abuts on engaged inclined surface 206b of engaging recess 206, movement of first member 180 in the +Z direction relative to second member 190 is restricted. Furthermore, since inclined surface 205b and engaged inclined surface 206b are inclined surfaces that are inclined with respect to the XY plane, by pressing first member 180 against second member 190 in the +Z direction, inclined surface 205b and engaged inclined surface 206b slide against each other, and hook 205 can be moved to the outside of second circumferential wall portion 191. Therefore, by simply pushing the first member 180 in the +Z direction from a state in which the hook 205 is engaged with the third engagement recess 206C, the hook 205 can be moved to a position in which it engages with the second engagement recess 206B, and can also be moved to a position in which it engages with the first engagement recess 206A.

[0081] Furthermore, knobs 187 that protrude outward and can be gripped are provided on the outer peripheral surfaces of both sides in the X-axis direction of first circumferential wall portion 181 of first member 180. By providing knobs 187 on both sides in the X-axis direction, first circumferential wall portions 181 on both sides in the X-axis direction can be easily elastically deformed in directions away from each other. In this way, by using knobs 187 to elastically deform first circumferential wall portions 181 on both sides in the X-axis direction in directions away from each other, engaging surfaces 205a of hooks 205 disengage from engaged surfaces 206a of engaging recesses 206, and first member 180 can be moved in the -Z direction. That is, in this embodiment, knobs 187 are an example of a "release means."

[0082] As described above, the fixing means of this embodiment is a snap fit that positions and fixes the first member 180 and the second member 190 by the engagement between the hook 205 and the engagement recess 206.

[0083] In this embodiment, as shown in Fig. 12, the position of first member 180 relative to second member 190 when hook 205 is engaged with first engagement recess 206A is referred to as the first position. Also, as shown in Fig. 11, the position of first member 180 relative to second member 190 when hook 205 is engaged with second engagement recess 206B is referred to as the second position. Also, although not specifically shown, the position of first member 180 relative to second member 190 when hook 205 is engaged with third engagement recess 206C is referred to as the third position. The dimension of cover 170 in the Z-axis direction at the third position is greater than dimension L2 of cover 170 in the Z-axis direction at the second position, and dimension L2 of cover 170 in the Z-axis direction at the second position is greater than dimension L1 of cover 170 in the Z-axis direction at the first position.

[0084] In this embodiment, three engaging recesses 206 are provided for one hook 205, but the number of engaging recesses 206 may be two, or four or more.

[0085] In addition, in this embodiment, a hook 205 is provided on the first member 180 and an engaging recess 206 is provided on the second member 190, but this is not particularly limited to this, and an engaging recess may be provided on the first member 180 and a hook 205 may be provided on the second member 190.

[0086] In this embodiment, the hook 205 is an example of a "first engaging portion," the first engaging recess 206A is an example of a "first engaged portion," and the second engaging recess 206B is an example of a "second engaged portion."

[0087] Note that, in the present embodiment, a configuration in which the second member 190 is disposed inside the first member 180 has been exemplified, but the present invention is not particularly limited to this, and the first member 180 may be disposed inside the second member 190. Such a modified example of the liquid jet head H of the third embodiment is shown in Fig. 13. Fig. 13 is a cross-sectional view of a main part illustrating a modified example of the liquid jet head H of the third embodiment, and is a view illustrating a first position.

[0088] As shown in FIG. 13, the first penetration portion 192 of the second member 190 is slightly larger than the first circumferential wall portion 181 of the first member 180, and the first member 180 is inserted into the first penetration portion 192.

[0089] A hook 205 is provided on the inside of the -Z direction end of the second circumferential wall portion 191. An engagement recess 206 is provided on the outer circumferential surface of the first circumferential wall portion 181. Three engagement recesses 206 are provided at different positions in the Z axis direction.

[0090] Furthermore, the end of first circumferential wall portion 181 in the -Z direction is formed as thin-walled portion 188 that is thinner than other regions. By providing thin-walled portion 188 in this manner, it becomes easier to deform first circumferential wall portion 181 on both sides in the X-axis direction of first member 180 in directions that bring them closer to each other when releasing the engagement between hook 205 and engagement recess 206. That is, in the example shown in FIG. 13 , thin-walled portion 188 is an example of a "release means."

[0091] In this embodiment, a seal member may be provided between the hook 205 and the engagement recess 206. Such an example is shown in FIGS. 14 and 15. FIGS. 14 and 15 are enlarged cross-sectional views of essential parts illustrating modified examples of the liquid jet head H of this embodiment. As shown in FIG. 14, a seal member 230 formed of an elastic material such as rubber is provided on either or both of the surfaces where the hook 205 and the engagement recess 206 face each other in the Z axis direction, i.e., the engagement surface 205a and the engaged surface 206a. In this embodiment, the seal member 230 is provided on the engaged surface 206a of the engagement recess 206. This allows the seal member 230 to seal the gap between the engagement surface 205a and the engaged surface 206a, thereby preventing ink from entering the cover 170 through this gap.

[0092] 15 , a seal member 231 may be provided on at least one of the surfaces of the first circumferential wall portion 181 and the second circumferential wall portion 191 that face each other in a direction perpendicular to the Z-axis direction. In this embodiment, the seal member 231 is provided on the outer peripheral surface of the second circumferential wall portion 191. This allows the gap between the first circumferential wall portion 181 and the second circumferential wall portion 191 to be sealed by the seal member 231, thereby preventing ink from entering the cover 170 through this gap. Of course, both of these seal members 230 and 231 may be provided. In this way, providing the seal members 230 and 231 prevents ink from entering the inside of the cover 170 from between the first member 180 and the second member 190.

[0093] (Other embodiments) Although the embodiments of the present invention have been described above, the basic configuration of the present invention is not limited to those described above.

[0094] For example, in the first and second embodiments described above, a sealing member made of an elastic material may be provided to prevent ink from entering between the first member 180 and the second member 190.

[0095] Furthermore, in the above-described first and second embodiments, the second member 190 is provided with the female screw 201 or the nut 202, but this is not particularly limited. For example, a spiral thread groove may be formed on the inner circumferential surface of the first through hole 184 provided in the first circumferential wall portion 181 of the first member 180, thereby forming the first through hole 184 as a female screw. The tip of the male screw 200 threaded into the first through hole 184 may be pressed against the outer circumferential surface of the second circumferential wall portion 191 of the second member 190, thereby fixing the first member 180 and the second member 190 together. With this configuration, the first member 180 can be positioned at any position in the Z-axis direction relative to the second member 190, and since the second member 190 does not have the second through hole 196, it is possible to prevent ink from entering the inside of the cover 170 through the second through hole 196.

[0096] Furthermore, in each of the above-described embodiments, the cover 170 is configured from two members, the first member 180 and the second member 190. However, this is not particularly limited, and the cover 170 may be configured from three or more members. Here, an example in which the cover 170 is configured from three members is shown in FIGS. 16 and 17. Note that FIG. 16 is a cross-sectional view of a main portion of a liquid jet head H according to another embodiment, and is a diagram showing a fifth position. Also, FIG. 17 is a cross-sectional view of a main portion of a liquid jet head H according to another embodiment, and is a diagram showing a fourth position. Also, fixing means are omitted in FIGS. 16 and 17.

[0097] As shown in FIGS. 16 and 17, the cover 170 includes a first member 180, a second member 190, and a third member 240.

[0098] The first member 180 is disposed furthest in the −Z direction, and includes a first peripheral wall portion 181 and a bottom wall portion 182, similar to the above-described embodiments.

[0099] The second member 190 is disposed in the +Z direction of the first member 180, and has a second circumferential wall portion 191, similar to the embodiments described above. In this embodiment, the second member 190 is not provided with a flange portion. By inserting the first circumferential wall portion 181 of the first member 180 into the through-hole of the second member 190, the first member 180 can move to a first position and a second position relative to the second member 190.

[0100] The third member 240 is disposed in the +Z direction of the second member 190. The third member 240 has a third circumferential wall portion 241 that is annular when viewed in the Z-axis direction, and a flange portion 193. The third member 240 has a second through portion 242 that penetrates along the Z-axis direction defined by the third circumferential wall portion 241. By inserting the third circumferential wall portion 241 of the third member 240 into the first through portion 192 of the second circumferential wall portion 191 of the second member 190, the second member 190 is able to move in the Z-axis direction relative to the third member 240. The flange portion 193 has a configuration similar to the flange portion 193 provided on the second member 190 in each of the above-described embodiments.

[0101] Here, the second member 190 is movable in the Z-axis direction relative to the third member 240, thereby being movable between a fourth position shown in FIG. 17 and a fifth position shown in FIG. 16. Here, the dimension L5 of the cover 170 in the Z-axis direction when the second member 190 is located at the fifth position is greater than the dimension L4 of the cover 170 in the Z-axis direction when the second member 190 is located at the fourth position. That is, the relationship L5>L4 is satisfied. The comparison of the dimensions L4 and L5 of the cover 170 when located at the fourth and fifth positions is based on the case where the position of the first member 180 relative to the second member 190 is the same. In other words, the dimension of the cover 170 in the Z-axis direction differs when the position of the first member 180 relative to the second member 190 is located at the first position and the second position. Therefore, when comparing the fourth position and the fifth position, if the first position and the second position are mixed, the comparison cannot be performed accurately.

[0102] 16 and 17 do not show the fastening means for fastening the first member 180 and the second member 190 together, but any of the fastening means in each of the above-described embodiments may be used. The same applies to the fastening means for fastening the second member 190 and the third member 240 together.

[0103] By configuring the cover 170 from three members in this way, the dimension of the cover 170 in the Z-axis direction can be further increased, and the dimension of the cover 170 in the Z-axis direction can be changed in multiple stages. Therefore, the cover 170 shown in Figures 16 and 17 can accommodate a greater variety of different specifications of the liquid jet head H.

[0104] 16 and 17, the cover 170 is configured from two members, the first member 180 and the second member 190, or three members, the first member 180, the second member 190, and the third member 240, but is not particularly limited to this. For example, the cover 170 may be configured from only the first member 180, and a portion of the first circumferential wall portion 181 may be formed into a bellows shape that extends in the Z-axis direction. Even with such a cover 170, the dimension in the Z-axis direction can be changed in accordance with changes in the height of the built-in components, and therefore the cover 170 can be commonly used for liquid jet heads H of various specifications.

[0105] In the above-described liquid ejection device 1, an example was given in which the liquid ejection head H is mounted on a holder 6a and moves in the main scanning direction, but this is not particularly limited to this, and the present invention can also be applied to, for example, a so-called line printer in which the liquid ejection head H is fixed and printing is performed simply by moving the medium S in the sub-scanning direction.

[0106] Furthermore, the present invention is broadly applicable to liquid ejection devices in general that include a liquid ejection head. Examples of liquid ejection heads include various inkjet recording heads used in image recording devices such as printers, and colorant ejection heads used in manufacturing color filters for liquid crystal displays and the like. Examples of liquid ejection heads include electrode material ejection heads used in forming electrodes for organic EL displays, FEDs (field emission displays), and the like, and bioorganic material ejection heads used in biochip manufacturing, and the present invention can also be applied to liquid ejection devices that include these liquid ejection heads.

[0107] (Addendum) From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0108] A liquid jet head according to a first preferred embodiment includes a liquid jet unit that jets liquid, a flow path member that communicates with the liquid jet unit, a relay board that is electrically connected to the liquid jet unit, and a cover that accommodates at least one of the flow path member and the relay board and is expandable in the height direction. This allows the height dimension of the cover to be changed in accordance with the specifications of the liquid jet head. This allows the cover to be standardized for liquid jet heads with different specifications. Therefore, even if the specifications of the liquid jet head are changed not only at the time of shipment from the factory but also at the customer's site, the customer does not need to prepare and store multiple types of covers with different height dimensions, and does not need to provide a new cover to the customer, thereby reducing the environmental impact.

[0109] In Aspect 2, which is a specific example of Aspect 1, the cover includes a first member having a recessed shape and a second member including a second peripheral wall portion having an annular shape when viewed in the height direction, and the first member is movable in the height direction relative to the second member to move between a first position and a second position in which the height dimension of the cover is larger than the height dimension of the cover when positioned in the first position. This allows the height dimension of the cover to be changed in two stages between the first position and the second position.

[0110] In Aspect 3, which is a specific example of Aspect 2, the cover includes fixing means capable of fixing the first member so as not to move relative to the second member at each of the first position and the second position, thereby making the cover positionable at the first position and the second position.

[0111] In Aspect 4, which is a specific example of Aspect 3, the first member can move in the height direction relative to the second member to a third position where the height dimension of the cover is greater than the height dimension of the cover when the cover is located at the second position, and the fixing means can fix the first member so that it does not move relative to the second member at the third position. This allows the height dimension of the cover to be changed in three or more stages, making the cover compatible with liquid jet heads of various specifications.

[0112] In Aspect 5, which is a specific example of Aspect 3, the fixing means has a first engaging portion provided on one of the first member and the second member and a first engaged portion and a second engaged portion provided on the other, wherein the first engaging portion and the first engaged portion engage with each other to fix the first member so as to prevent movement relative to the second member at the first position, and the first engaging portion and the second engaged portion engage with each other to fix the first member so as to prevent movement relative to the second member at the second position. This makes it possible to easily fix the first member and the second member at the first position and the second position.

[0113] In Aspect 6, which is a specific example of Aspect 1, the liquid jet head includes a base member that houses the liquid jet unit, and the cover is detachably fixed to the base member. This allows the cover to be easily attached and detached from the base member, facilitating changes to the specifications of the liquid jet head.

[0114] In Aspect 7, which is a specific example of Aspect 2, the cover includes a third member connected to the first member via the second member and including a third circumferential wall portion that is annular when viewed in the height direction, and the second member is movable in the height direction relative to the third member to move between a fourth position and a fifth position in which the height dimension of the cover is greater than the height dimension of the cover when positioned in the fourth position. This increases the variation in the height dimension of the cover, making it possible to accommodate liquid jet heads with a wider variety of specifications.

[0115] In Aspect 8, which is a specific example of Aspect 2, the flow path member has a flow path pipe extending in the height direction, and the first member includes a bottom wall portion having an opening penetrating in the height direction, a first seal member disposed within the opening, and a second seal member disposed within the opening and at a different position in the height direction relative to the first seal member, wherein the first seal member blocks a gap between an outer circumferential surface of the flow path pipe and an inner circumferential surface of the opening when the flow path pipe is inserted into the opening and does not block the opening when the flow path pipe is not inserted into the opening, and the second seal member opens the opening to allow the flow path pipe to be inserted into the opening when the flow path can is inserted and blocks the opening when the flow path can is not inserted. This configuration allows the first seal member to prevent liquid dripping from the flow path pipe or mist-like liquid generated by spraying from entering the cover when the flow path can is inserted. Furthermore, when the flow path can is not inserted, the second seal member prevents liquid dripping from the flow path pipe and adhering to the cover or mist-like liquid from entering the cover.

[0116] In Aspect 9, which is a specific example of Aspect 8, the first member has a first opening that is the opening in the inserted state and a second opening that is the opening in the non-inserted state. The first opening can prevent liquid from entering the interior of the cover by a first sealing member, and the second opening can prevent liquid from entering the interior of the cover by a second sealing member.

[0117] In Aspect 10, which is a specific example of Aspect 8, the second seal member is disposed closer to the outer surface of the cover than the first seal member in the height direction. This prevents liquid from entering the first seal member when the cover is not inserted, and prevents liquid adhering to the first seal member from entering the cover when the cover is inserted.

[0118] In Aspect 11, which is a specific example of Aspect 3, the cover includes a release means for releasing the fixed state of the first member and the second member by the fixing means. By providing the release means for releasing the fixed state by the fixing means, the dimension of the cover in the height direction can be easily changed.

[0119] In Aspect 12, which is a specific example of Aspect 3, the fixing means includes a male screw, a first female screw threadedly engaging with the male screw to fix the first member to the second member at the first position, and a second female screw threadedly engaging with the male screw to fix the first member to the second member at the second position, the first member including a first circumferential wall portion having an annular shape when viewed in the height direction, the first female screw and the second female screw being formed on one of the first circumferential wall portion and the second circumferential wall portion located on the inner side, the first female screw having a concave shape that opens on the outer circumferential surface of the one circumferential wall portion but does not open on the inner circumferential surface of the one circumferential wall portion. This allows the first member and the second member to be easily fixed together by screw fixing.

[0120] In Aspect 13, which is a specific example of Aspect 3, the fixing means includes a male thread, a first nut that is threadedly engaged with the male thread to fix the first member to the second member at the first position, and a second nut that is threadedly engaged with the male thread to fix the first member to the second member at the second position. The first member includes a first peripheral wall portion that is annular when viewed in the height direction. The first nut and the second nut are provided on the inner peripheral surface of one of the first peripheral wall portion and the second peripheral wall portion, which is located on the inner side. When the first member is fixed to the second member at the second position, the screw hole of the first nut is covered by the other peripheral wall portion, which is located on the outer side. This allows for easy screw fixing at the first and second positions. Furthermore, covering the screw hole of the first nut with the other peripheral wall portion, which is located on the outer side, at the second position prevents liquid from entering the cover through the screw hole.

[0121] In aspect 14, which is a specific example of aspect 3, the fixing means has a male screw, a first female screw that can fix the first member to the second member at the first position by threading onto the male screw, and a second female screw that can fix the first member to the second member at the second position by threading onto the male screw, and the first member includes a first circumferential wall portion that is annular when viewed in the height direction, and the threaded hole of the first female screw is formed on the inner surface of a second through hole A formed in one of the first circumferential wall portion and the second circumferential wall portion that is located on the inner side, and the threaded hole of the second female screw is formed on the inner surface of a second through hole B formed in one of the circumferential wall portions, and when the first member is fixed to the second member at the second position, the second through hole A is covered by the other circumferential wall portion that is located on the outer side of the first circumferential wall portion and the second circumferential wall portion. According to this, when the first member is fixed to the second member at the second position, the second through hole A is covered by the other peripheral wall portion located on the outside, thereby preventing liquid from entering the cover through the screw hole.

[0122] In Aspect 15, which is a specific example of Aspect 3, the first member includes a first circumferential wall portion that is annular when viewed in the height direction. One of the first and second circumferential wall portions, which is located on the inside, has a second through hole A and a second through hole B. The fastening means includes a male thread and a nut that can fix the first member to the second member at the first position by threadingly engaging with the male thread inserted into the second through hole A and can fix the first member to the second member at the second position by threadingly engaging with the male thread inserted into the second through hole B. The second through hole A is covered by the other of the first and second circumferential wall portions, which is located on the outside, when the first member is fixed to the second member at the second position. This prevents liquid from entering the cover through the screw hole. Furthermore, the number of nuts can be reduced, thereby reducing costs.

[0123] A liquid ejection device according to a sixteenth preferred aspect includes the liquid ejection head according to any of the above aspects and a liquid storage unit that stores liquid to be supplied to the liquid ejection head. This allows the height dimension of the cover to be changed in accordance with the specifications of the liquid ejection head. This allows the cover to be standardized for liquid ejection heads of different specifications, thereby reducing the environmental impact. [Explanation of symbols]

[0124] H...liquid ejection head, Hc...head chip, N...nozzle, S...medium, 1...liquid ejection device, 3...liquid storage section, 4...control section, 5...transport mechanism, 6...movement mechanism, 7...pump, 110...wiring board, 130...base member, 131...accommodation section, 34...communicating path, 39...wiring insertion hole, 140...fixing plate, 141...exposure opening, 150, 150A...flow path member, 151...flow path connection section, 160...relay board, 161...first relay board, 162...second relay board, 163...third relay board, 164...external connector, 170...cover, 180...first member, 181...first peripheral wall section, 182...bottom wall section, 183...recess, 184...first through hole, 185...electrical connection opening, 186...flow path connection opening, 187...grip section, 188... Thin-walled portion, 190...second member, 191...second peripheral wall portion, 192...first through-hole, 193...flange portion, 194...first cover fixing hole, 195...cover fixing screw, 196, 196A, 196B...second through-hole, 200...male thread, 201...female thread, 201A...first female thread, 201B...second female thread, 202...nut, 202A...first nut, 202B...second nut nut, 205...hook, 206...engagement recess, 206A...first engagement recess, 206B...second engagement recess, 206C...third engagement recess, 210...first seal member, 211...flow path connection portion insertion hole, 220...second seal member, 221...slit portion, 222...protrusion, 230, 231...seal member, 240...third member, 241...third peripheral wall portion, 242...second through portion.

Claims

1. a liquid ejection unit that ejects liquid; a flow path member communicating with the liquid ejection unit; an intermediate substrate electrically connected to the liquid ejection unit; a cover that accommodates at least one of the flow path member and the relay substrate therein and is expandable in a height direction; A liquid jet head comprising:

2. The cover is a first member having a concave shape; a second member including a second peripheral wall portion that is annular when viewed in the height direction; Including, The first member is movable in the height direction relative to the second member, and thereby is movable between a first position and a second position in which the height dimension of the cover is larger than the height dimension of the cover when the first member is located at the first position. The liquid jet head according to claim 1 .

3. the cover includes a fixing means capable of fixing the first member so as not to move relative to the second member at each of the first position and the second position. The liquid jet head according to claim 2 .

4. the first member is movable in the height direction relative to the second member to a third position in which the height dimension of the cover is larger than the height dimension of the cover when the first member is located at the second position, the fixing means is capable of fixing the first member to prevent movement relative to the second member in the third position. The liquid jet head according to claim 3 .

5. The fixing means is a first engagement portion provided on one of the first member and the second member; a first engaged portion and a second engaged portion provided on the other side; and When the first engaging portion and the first engaged portion are engaged with each other, the first member is fixed at the first position so as not to move relative to the second member, When the first engaging portion and the second engaged portion are engaged with each other, the first member is fixed at the second position so as not to move relative to the second member. The liquid jet head according to claim 3 .

6. the liquid jet head includes a base member that houses the liquid jet unit; The cover is removably fixed to the base member. The liquid jet head according to claim 1 .

7. the cover includes a third member that is connected to the first member via the second member and includes a third peripheral wall portion that is annular when viewed in the height direction, The second member is movable in the height direction relative to the third member between a fourth position and a fifth position in which the height dimension of the cover is larger than the height dimension of the cover when the second member is located at the fourth position. The liquid jet head according to claim 2 .

8. the flow path member has a flow path pipe extending in the height direction, The first member is a bottom wall portion having an opening penetrating in the height direction; a first seal member disposed within the opening; a second seal member that is disposed within the opening and that is disposed at a different position in the height direction from the first seal member, the first seal member closes a gap between an outer peripheral surface of the flow path pipe and an inner peripheral surface of the opening when the flow path pipe is inserted into the opening and does not close the opening when the flow path pipe is not inserted into the opening and is not inserted into the opening, The second seal member opens the opening in the inserted state so that the flow path pipe can be inserted into the opening, and closes the opening in the non-inserted state. The liquid jet head according to claim 2 .

9. The first member has a first opening that is the opening in the inserted state and a second opening that is the opening in the non-inserted state. The liquid jet head according to claim 8 .

10. The second seal member is disposed closer to the outer surface of the cover than the first seal member in the height direction. The liquid jet head according to claim 8 .

11. the cover includes a release means for releasing the fixed state of the first member and the second member by the fixing means, The liquid jet head according to claim 3 .

12. The fixing means is A male screw and a first female screw that can fix the first member to the second member at the first position by being threadedly engaged with the male screw; a second female screw that can fix the first member to the second member at the second position by being threadedly engaged with the male screw; and the first member includes a first peripheral wall portion that is annular when viewed in the height direction, the first female thread and the second female thread are formed on one of the first peripheral wall portion and the second peripheral wall portion, the one being located on an inner side; The first female thread has a concave shape that opens to an outer circumferential surface of the one peripheral wall portion and does not open to an inner circumferential surface of the one peripheral wall portion. The liquid jet head according to claim 3 .

13. The fixing means is A male screw and a first nut that is capable of fixing the first member to the second member at the first position by being threadedly engaged with the male thread; a second nut that is threadably engaged with the male thread to fix the first member to the second member at the second position; and the first member includes a first peripheral wall portion that is annular when viewed in the height direction, the first nut and the second nut are provided on an inner circumferential surface of one of the first circumferential wall portion and the second circumferential wall portion, the one being located on an inner side; the screw hole of the first nut is covered by the other peripheral wall portion located on an outer side of the first peripheral wall portion or the second peripheral wall portion when the first member is fixed to the second member at the second position; The liquid jet head according to claim 3 .

14. The fixing means is A male screw and a first female screw that can fix the first member to the second member at the first position by being threadedly engaged with the male screw; a second female screw that can fix the first member to the second member at the second position by being threadedly engaged with the male screw; and the first member includes a first peripheral wall portion that is annular when viewed in the height direction, The threaded hole of the first female screw is formed in an inner circumferential surface of a second through hole A formed in one of the first circumferential wall portion and the second circumferential wall portion, the one being located on the inner side, The threaded hole of the second female screw is formed on an inner circumferential surface of a second through hole B formed in the one circumferential wall portion, the second through hole A is covered by the other peripheral wall portion located on an outer side of the first peripheral wall portion or the second peripheral wall portion when the first member is fixed to the second member at the second position. The liquid jet head according to claim 3 .

15. the first member includes a first peripheral wall portion that is annular when viewed in the height direction, One of the first and second peripheral wall portions, which is located on the inner side, has a second through hole A and a second through hole B, The fixing means is A male screw and a nut that can fix the first member to the second member at the first position by being threadedly engaged with the male screw inserted into the second through hole A, and that can fix the first member to the second member at the second position by being threadedly engaged with the male screw inserted into the second through hole B; and the second through hole A is covered by the other peripheral wall portion located on an outer side of the first peripheral wall portion or the second peripheral wall portion when the first member is fixed to the second member at the second position. The liquid jet head according to claim 3 .

16. A liquid jet head according to any one of claims 1 to 15, a liquid storage section that stores the liquid to be supplied to the liquid jet head; Equipped with A liquid ejection device characterized by:

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