Liquid ejection head and liquid ejection device

Abstract

The present invention provides a liquid ejection head and a liquid ejection device that suppress the increase of the flow channel resistance of the nozzle flow channel while reducing the occurrence of structural crosstalk. The liquid ejection head comprises: a first pressure chamber, which extends in a first direction and applies pressure to the liquid; a second pressure chamber, which extends in the first direction and applies pressure to the liquid; a first nozzle flow channel, which extends in the first direction and is provided with a first nozzle for ejecting liquid; a first connecting flow channel, which extends in a second direction intersecting the first direction and is connected to the first pressure chamber and the first nozzle flow channel; a second connecting flow channel, which extends in a second direction and is connected to the second pressure chamber and the first nozzle flow channel, the first nozzle flow channel having a first part and a second part, the first part including one end of the first nozzle flow channel, the second part including the other end of the first nozzle flow channel, and the width of the second part in the second direction is greater than the width of the first part in the second direction.

Description

Technical Field

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

[0002] A liquid ejection head for ejecting liquid such as ink from a plurality of nozzles has been proposed. For example, Patent Document 1 discloses a liquid ejection head for ejecting liquid from a nozzle by changing the pressure of liquid in a pressure chamber using a piezoelectric element. The liquid ejection head has a plurality of nozzle flow channels provided with nozzles, and the plurality of nozzle flow channels are arranged along a predetermined direction.

[0003] In existing liquid ejection heads, so-called structural crosstalk may occur, in which vibration in one nozzle channel is transmitted to another nozzle channel between two adjacent nozzle channels, thereby reducing the ejection characteristics of ink ejected from the nozzle in the other nozzle channel.

[0004] On the other hand, when the flow channel resistance of the nozzle flow channel increases, it takes time to supply the liquid, which may cause ejection failure or increase the recording time.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-184372 Summary of the invention

[0006] In view of the above circumstances, an object of the present invention is to reduce the occurrence of structural crosstalk while suppressing an increase in the flow channel resistance of the nozzle flow channel.

[0007] In order to solve the above problems, a preferred embodiment of the present invention involves a liquid ejection head comprising: a first pressure chamber, which extends in a first direction and applies pressure to the liquid; a second pressure chamber, which extends in the first direction and applies pressure to the liquid; a first nozzle flow channel, which extends in the first direction and is provided with a first nozzle for ejecting liquid; a first connecting flow channel, which extends in a second direction intersecting the first direction and is connected to the first pressure chamber and the first nozzle flow channel; a second connecting flow channel, which extends in the second direction and is connected to the second pressure chamber and the first nozzle flow channel, the first nozzle flow channel having a first part and a second part, the first part including one end of the first nozzle flow channel, the second part including the other end of the first nozzle flow channel, the width of the second part in the second direction being greater than the width of the first part in the second direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram showing a partial configuration example of the liquid ejecting device according to the first embodiment.

[0009] Figure 2 A schematic diagram showing the flow path structure in a liquid ejection head.

[0010] Figure 3 for Figure 2 Cross-sectional view of line aa.

[0011] Figure 4 for Figure 2 Cross-sectional view of line bb.

[0012] Figure 5 It is a side view showing a structural example of an independent flow channel.

[0013] Figure 6 It is a side view showing a structural example of an independent flow channel.

[0014] Figure 7 for Figure 5 as well as Figure 6 Cross-sectional view of line dd.

[0015] Figure 8 for Figure 5 as well as Figure 6 Cross-sectional view of the cc line.

[0016] Fig. 9 The comparative example of the present invention involves Figure 5 as well as Figure 6 Cross-sectional view of line dd.

[0017] Fig.10 The above comparative example involves Figure 5 as well as Figure 6 Cross-sectional view of the cc line.

[0018] Fig.11 Other comparative examples of the present invention Figure 5 as well as Figure 6 Cross-sectional view of line dd.

[0019] Fig.12 The above comparative example involves Figure 5 as well as Figure 6 Cross-sectional view of the cc line.

[0020] Fig.13 It is a schematic diagram showing a flow path structure in a liquid ejection head according to a second embodiment.

[0021] Fig.14 It is a schematic diagram showing a flow path structure in a liquid ejection head according to a third embodiment.

[0022] Fig.15 The third embodiment involves Fig.14 Cross-sectional view of line aa.

[0023] Fig.16 The third embodiment involves Fig.14 Cross-sectional view of line bb.

[0024] Fig.17 The fourth embodiment involves Fig.14 Cross-sectional view of line aa.

[0025] Fig.18 The fourth embodiment involves Fig.14 Cross-sectional view of line bb.

[0026] Fig.19 The fifth embodiment involves Fig.14 Cross-sectional view of line aa.

[0027] Fig. 20 The fifth embodiment involves Fig.14 Cross-sectional view of line bb.

[0028] Fig.21 It is a schematic diagram showing a flow path structure in a liquid ejection head according to a sixth embodiment.

[0029] Fig. 22 for Fig.21 Cross-sectional view of line aa.

[0030] Fig.23 for Fig.21 Cross-sectional view of line bb.

[0031] Fig.24 It is a schematic diagram showing a flow path structure in a liquid ejection head according to a seventh embodiment.

[0032] Fig.25 for Fig.24 Cross-sectional view of line aa.

[0033] Fig.26 for Fig.24 Cross-sectional view of line bb.

[0034] Fig. 27 This is an enlarged cross-sectional view of an arbitrary nozzle.

[0035] Fig.28 It is a schematic diagram showing a flow path structure in a liquid ejection head according to a modified example.

[0036] Fig.29 for Fig.28 Cross-sectional view of line aa.

[0037] Fig.30 for Fig.28 Cross-sectional view of line bb. DETAILED DESCRIPTION

[0038] 1. First Implementation

[0039] In the following description, it is assumed that the X-axis, Y-axis, and Z-axis intersect each other. The X-axis, Y-axis, and Z-axis are common to all the drawings illustrated in the following description. Figure 1 As illustrated, a direction along the X-axis when observed from an arbitrary location is recorded as the X1 direction, and the direction opposite to the X1 direction is recorded as the X2 direction. The X1 direction is equivalent to the "first direction". Similarly, directions opposite to each other along the Y-axis from an arbitrary location are recorded as the Y1 direction and the Y2 direction. The Y2 direction is equivalent to the "third direction". In addition, directions opposite to each other along the Z-axis from an arbitrary location are recorded as the Z1 direction and the Z2 direction. The Z1 direction is equivalent to the "second direction". In addition, the XY plane including the X-axis and the Y-axis is equivalent to the horizontal plane. The Z-axis is an axis along the vertical direction, and the Z2 direction is equivalent to the downward direction in the vertical direction.

[0040] Figure 1 1 is a schematic diagram showing a partial structural example of a liquid ejection device 100 according to the present embodiment. The liquid ejection device 100 is an inkjet printing device that ejects droplets of a liquid such as ink onto a medium 11. The medium 11 is, for example, printing paper. The medium 11 may also be a printing object made of any material such as a resin film or cloth.

[0041] The liquid ejection device 100 is provided with a liquid container 12. The liquid container 12 stores ink. The liquid container 12 may be, for example, a box that can be attached to and detached from the liquid ejection device 100, a bag-shaped ink bag formed of a flexible film, or an ink tank that can be replenished with ink. In addition, the type of ink stored in the liquid container 12 is arbitrary.

[0042] like Figure 1 As shown, the liquid ejection device 100 includes a control unit 21, a conveying mechanism 22, a moving mechanism 23, and a liquid ejection head 24. The control unit 21 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, and controls the ejection action of the liquid ejection head 24 and other elements of the liquid ejection device 100. The control unit 21 is an example of a "control unit".

[0043] The conveying mechanism 22 conveys the medium 11 along the Y axis based on the control of the control unit 21. The moving mechanism 23 moves the liquid ejection head 24 back and forth along the X axis based on the control of the control unit 21. The moving mechanism 23 includes a substantially box-shaped conveying body 231 for accommodating the liquid ejection head 24, and an endless conveying belt 232 to which the conveying body 231 is fixed. In addition, in the present embodiment, a structure in which a plurality of liquid ejection heads 24 are mounted on the conveying body 231 and a structure in which the liquid container 12 and the liquid ejection head 24 are mounted on the conveying body 231 together can be adopted.

[0044] The liquid ejection head 24 ejects ink supplied from the liquid container 12 toward the medium 11 from each of the plurality of nozzles based on the control of the control unit 21. The liquid ejection head 24 ejects ink toward the medium 11 by making the conveyance of the medium 11 by the conveyance mechanism 22 and the repeated reciprocating movement of the conveyance body 231 parallel, thereby forming an image on the surface of the medium 11.

[0045] Figure 2 Schematic diagram showing the flow path structure in the liquid ejection head 24 when the liquid ejection head 24 is observed along the Z-axis direction. Figure 2 As shown, a plurality of nozzles Na and a plurality of nozzles Nb are formed on the surface of the liquid ejection head 24 that is opposite to the medium 11. The plurality of nozzles Na and the plurality of nozzles Nb are arranged along the Y axis. The plurality of nozzles Na and the plurality of nozzles Nb eject ink in the Z axis direction, respectively. Therefore, the Z axis direction corresponds to the direction in which the ink is ejected from each of the plurality of nozzles Na and the plurality of nozzles Nb. The nozzle Na is an example of a "first nozzle", and the nozzle Nb is an example of a "second nozzle".

[0046] like Figure 2 As shown in FIG. 1 , a plurality of nozzles Na constitute a first nozzle array La, and a plurality of nozzles Nb constitute a second nozzle array Lb. The first nozzle array La is a collection of a plurality of nozzles Na arranged in a straight line along the Y axis. Similarly, the second nozzle array Lb is a collection of a plurality of nozzles Nb arranged in a straight line along the Y axis. Figure 2 As shown, the first nozzle array La and the second nozzle array Lb are arranged in a manner separated by a predetermined interval in the X-axis direction. In addition, the position of each nozzle Na in the Y-axis direction is different from the position of each nozzle Nb in the Y-axis direction. Figure 2As shown in FIG. 1 , a plurality of nozzles N including nozzles Na and nozzles Nb are arranged at a pitch (period) θ. The pitch θ is the distance between the center of nozzle Na and the center of nozzle Nb in the Y-axis direction. In the following description, the element symbol associated with the nozzle Na of the first nozzle array La is suffixed with a, and the element symbol associated with the nozzle Nb of the second nozzle array Lb is suffixed with a b. In addition, when there is no need to distinguish between the nozzle Na of the first nozzle array La and the nozzle Nb of the second nozzle array Lb, they are simply described as "nozzle N".

[0047] like Figure 2 As shown, an independent flow channel array 25 is provided on the liquid ejection head 24. The independent flow channel array 25 is a collection of multiple independent flow channels Pa and multiple independent flow channels Pb. Each of the multiple independent flow channels Pa extends in the X1 direction and corresponds to a different nozzle Na. Each of the multiple independent flow channels Pa is connected to the nozzle Na. Similarly, each of the multiple independent flow channels Pb extends in the X1 direction and corresponds to a different nozzle Nb. Each of the multiple independent flow channels Pb is connected to the nozzle Nb. The detailed structure of the independent flow channels Pa and the independent flow channels Pb will be described below. In addition, in the subsequent description, when there is no need to specifically distinguish between the independent flow channels Pa and the independent flow channels Pb, they are only recorded as "independent flow channels P".

[0048] The independent flow channel Pa and the independent flow channel Pb that are opposite to each other in the Y-axis direction are in a reverse relationship with the Z-axis as the center. Specifically, the independent flow channel Pa has the same configuration as the independent flow channel Pb when it is rotated 180° around the Z-axis, and the independent flow channel Pb has the same configuration as the independent flow channel Pa when it is rotated 180° around the Z-axis.

[0049] like Figure 2 As shown, the independent flow channel Pa has a pressure chamber Ca1 and a pressure chamber Ca2. The pressure chamber Ca1 and the pressure chamber Ca2 in the independent flow channel Pa extend in the X1 direction. Ink ejected from the nozzle Na connected to the independent flow channel Pa is stored in the pressure chamber Ca1 and the pressure chamber Ca2. When the pressure in the pressure chamber Ca1 and the pressure chamber Ca2 changes, the ink is ejected from the nozzle Na. The pressure chamber Ca1 is an example of a "first pressure chamber", and the pressure chamber Ca2 is an example of a "second pressure chamber".

[0050] Similarly, the independent flow channel Pb has a pressure chamber Cb1 and a pressure chamber Cb2. The pressure chamber Cb1 and the pressure chamber Cb2 of the independent flow channel Pb extend in the X1 direction. Ink ejected from the nozzle Nb connected to the independent flow channel Pb is stored in the pressure chamber Cb1 and the pressure chamber Cb2. When the pressure in the pressure chamber Cb1 and the pressure chamber Cb2 changes, the ink is ejected from the nozzle Nb. The pressure chamber Cb1 is an example of the "third pressure chamber", and the pressure chamber Cb2 is an example of the "fourth pressure chamber".

[0051] In the following description, when there is no need to particularly distinguish between the pressure chambers Ca1 and Ca2 corresponding to the first nozzle row La and the pressure chambers Cb1 and Cb2 corresponding to the second nozzle row Lb, they are simply described as “pressure chambers C”.

[0052] like Figure 2 As shown in FIG. 1 , a first common liquid chamber R1 and a second common liquid chamber R2 are provided in the liquid ejection head 24. The first common liquid chamber R1 and the second common liquid chamber R2 extend in the Y-axis direction across the entire range in which the plurality of nozzles N are distributed. In a plane observation along the Z-axis direction, the independent flow channel array 25 and the plurality of nozzles N are located between the first common liquid chamber R1 and the second common liquid chamber R2. In the following description, the plane observation along the Z-axis direction is simply described as “plane observation”.

[0053] A plurality of independent flow channels P are commonly connected to the first common liquid chamber R1. Specifically, the end E1 of each independent flow channel P located in the X2 direction is connected to the first common liquid chamber R1. Similarly, a plurality of independent flow channels P are commonly connected to the second common liquid chamber R2. Specifically, the end E2 of each independent flow channel P located in the X1 direction is connected to the second common liquid chamber R2. In the liquid ejection head 24, each independent flow channel P enables the first common liquid chamber R1 and the second common liquid chamber R2 to be mutually connected. Thus, the ink supplied from the first common liquid chamber R1 to each independent flow channel P is ejected from the nozzle N. The ink that is not ejected is discharged to the second common liquid chamber R2.

[0054] like Figure 2 As shown in FIG. 1 , the liquid ejection head 24 includes a circulation mechanism 26. The circulation mechanism 26 is a mechanism for returning the ink discharged from each independent flow path P to the second common liquid chamber R2 to the first common liquid chamber R1. The circulation mechanism 26 includes a first supply pump 261, a second supply pump 262, a storage container 263, a circulation flow path 264, and a supply flow path 265.

[0055] The first supply pump 261 is a pump that supplies the ink stored in the liquid container 12 to the storage container 263. The storage container 263 is a sub-tank that temporarily stores the ink supplied from the liquid container 12.

[0056] The circulation channel 264 is a channel that connects the second common liquid chamber R2 and the storage container 263, and discharges ink from the discharge channel Ra2 and the discharge channel Rb2 described later in a common manner through the second common liquid chamber R2. The circulation channel 264 and the second common liquid chamber R2 are an example of a "common discharge channel".

[0057] In addition to the ink stored in the liquid container 12 being supplied from the first supply pump 261 , the storage container 263 is also supplied with the ink discharged from each independent flow path P to the second common liquid chamber R2 via the circulation flow path 264 .

[0058] The second supply pump 262 is a pump that delivers the ink stored in the storage container 263. The ink delivered from the second supply pump 262 is supplied to the first common liquid chamber R1 via the supply flow path 265. The supply flow path 265 supplies liquid to the supply flow path Ra1 and the supply flow path Rb1 described later in a common manner. The supply flow path 265 and the first common liquid chamber R1 are an example of a "common supply flow path".

[0059] The plurality of independent flow channels P of the independent flow channel array 25 include a plurality of independent flow channels Pa and a plurality of independent flow channels Pb. The plurality of independent flow channels Pa are each an independent flow channel P connected to a nozzle Na of the first nozzle array La. The plurality of independent flow channels Pb are each an independent flow channel P connected to a nozzle Nb of the second nozzle array Lb. The independent flow channels Pa and the independent flow channels Pb are arranged alternately along the Y axis. Thus, the independent flow channels Pa and the independent flow channels Pb are arranged to face each other in the Y axis direction.

[0060] like Figure 2 As shown in FIG. 1 , the independent flow channel Pa has a nozzle flow channel Nfa. As shown in the figure, the nozzle flow channel Nfa extends in the X1 direction and is located between the pressure chamber Ca1 and the pressure chamber Ca2 when viewed along the Z2 direction. The nozzle flow channel Nfa communicates with the pressure chamber Ca1 and the pressure chamber Ca2, and is provided with a nozzle Na that ejects the ink supplied from the pressure chamber Ca1. The nozzle flow channel Nfa is an example of a "first nozzle flow channel".

[0061] like Figure 2 As shown in the figure, the independent flow channel Pb has a nozzle flow channel Nfb. As shown in the figure, the nozzle flow channel Nfb extends in the X1 direction and is located between the pressure chamber Cb1 and the pressure chamber Cb2 when viewed along the Z2 direction. The nozzle flow channel Nfb is connected to the pressure chamber Cb1 and the pressure chamber Cb2, and is provided with a nozzle Nb that ejects the ink supplied from the pressure chamber Cb1. The nozzle flow channel Nfb is an example of a "second nozzle flow channel".

[0062] The nozzle flow channel Nfa and the nozzle flow channel Nfb are arranged in a row along the Y-axis direction. The nozzle flow channel Nfa and the nozzle flow channel Nfb are arranged in a manner separated by a predetermined interval in the Y-axis direction. The nozzle flow channel Nfa and the nozzle flow channel Nfb adjacent to each other in the Y-axis direction are in a reverse relationship with the Z-axis as the center. In addition, in the present application, element A and element B are "adjacent" to each other, which means that when element A and element B are observed along a specific direction, at least a part of element A and at least a part of element B are opposite to each other. It is not necessary to make all of element A and all of element B opposite to each other. It is only necessary that at least a part of element A and at least a part of element B are opposite to each other, and it can be interpreted as "element A and element B are adjacent".

[0063] like Figure 2 As shown, in the liquid ejection head 24 of the present embodiment, a plurality of pressure chambers Ca1 corresponding to different nozzles Na of the first nozzle array La and a plurality of pressure chambers Cb1 corresponding to different nozzles Nb of the second nozzle array Lb are arranged in a row along the Y-axis direction. Similarly, a plurality of pressure chambers Ca2 corresponding to different nozzles Na of the first nozzle array La and a plurality of pressure chambers Cb2 corresponding to different nozzles Nb of the second nozzle array Lb are arranged in a row along the Y-axis direction. The arrangement consisting of the plurality of pressure chambers Ca1 and the plurality of pressure chambers Cb1 and the arrangement consisting of the plurality of pressure chambers Ca2 and the plurality of pressure chambers Cb2 are arranged in a manner spaced apart by a predetermined interval in the X-axis direction. Here, although the position of each pressure chamber Ca1 in the Y-axis direction and the position of each pressure chamber Ca2 in the Y-axis direction are the same, they may be different. In addition, although the position of each pressure chamber Cb1 in the Y-axis direction and the position of each pressure chamber Cb2 in the Y-axis direction are also the same, they may be different.

[0064] Next, the detailed structure of the liquid ejection head 24 will be described. Figure 3 for Figure 2 The cross-sectional view of line aa, Figure 4 for Figure 2 The cross-sectional view of the bb line. Figure 3 In FIG. 1 , a cross section through an independent flow channel Pa is shown. Figure 4 , a cross section through the independent flow channel Pb is shown.

[0065] like Figure 3 as well as Figure 4 As shown, the liquid ejection head 24 includes a flow channel structure 30, a plurality of piezoelectric elements 41, a frame portion 42, a protective substrate 43, and a wiring substrate 44. The flow channel structure 30 is a structure that forms a flow channel having a first common liquid chamber R1, a second common liquid chamber R2, a plurality of independent flow channels P, and a plurality of nozzles N.

[0066] The flow channel structure 30 is a structure in which a nozzle plate 31, a connecting plate 33, a pressure chamber substrate 34, and a vibration plate 35 are sequentially laminated in the Z1 direction. These elements constituting the flow channel structure 30 are manufactured by, for example, processing a silicon single crystal substrate using a common processing method for manufacturing semiconductors.

[0067] A plurality of nozzles N are formed on the nozzle plate 31. The plurality of nozzles N are cylindrical through holes through which ink passes. Figure 3 as well as Figure 4 As shown, the nozzle plate 31 is a plate-shaped member having a surface Fa1 facing the Z2 direction and a surface Fa2 facing the Z1 direction. The communication plate 33 is a plate-shaped member having a surface Fc1 facing the Z2 direction and a surface Fc2 facing the Z1 direction.

[0068] Each element constituting the flow channel structure 30 is formed into a rectangular shape that is long and narrow in the Y-axis direction, and is bonded to each other by, for example, an adhesive. For example, the surface Fa2 of the nozzle plate 31 is bonded to the surface Fc1 of the connecting plate 33, and the surface Fc2 of the connecting plate 33 is bonded to the surface Fd1 of the pressure chamber substrate 34. The surface Fd2 of the pressure chamber substrate 34 is bonded to the surface Fe1 of the vibration plate 35.

[0069] A space O12 and a space O22 are formed in the connecting plate 33. The space O12 and the space O22 are respectively long and narrow openings in the Y-axis direction. A vibration absorbing body 361 for blocking the space O12 and a vibration absorbing body 362 for blocking the space O22 are provided on the surface Fc1 of the connecting plate 33. The vibration absorbing body 361 and the vibration absorbing body 362 are layered components formed of an elastic material.

[0070] The frame portion 42 is a shell for storing ink. The frame portion 42 is joined to the surface Fc2 of the connecting plate 33. A space O13 connected to the space O12 and a space O23 connected to the space O22 are formed in the frame portion 42. The space O13 and the space O23 are respectively long and narrow spaces in the Y-axis direction. The space O12 and the space O13 are connected to each other to form the first common liquid chamber R1. Similarly, the space O22 and the space O23 are connected to each other to form the second common liquid chamber R2. The vibration absorbing body 361 constitutes the wall surface of the first common liquid chamber R1 and absorbs the pressure fluctuation of the ink in the first common liquid chamber R1. The vibration absorbing body 362 constitutes the wall surface of the second common liquid chamber R2 and absorbs the pressure fluctuation of the ink in the second common liquid chamber R2.

[0071] The frame portion 42 is formed with a supply port 421 and a discharge port 422. The supply port 421 is a pipe communicating with the first common liquid chamber R1, and is connected to the supply flow path 265 of the circulation mechanism 26. The ink sent from the second supply pump 262 to the supply flow path 265 is supplied to the first common liquid chamber R1 via the supply port 421. On the other hand, the discharge port 422 is a pipe communicating with the second common liquid chamber R2, and is connected to the circulation flow path 264 of the circulation mechanism 26. The ink in the second common liquid chamber R2 is supplied to the circulation flow path 264 via the discharge port 422.

[0072] Pressure chambers Ca1 and Ca2, pressure chambers Cb1 and Cb2 are provided on the pressure chamber substrate 34. Each pressure chamber C is a space between the surface Fc2 of the communication plate 33 and the vibration plate 35. Each pressure chamber C is formed into a strip along the X axis when viewed in a plan view, and extends in the X1 direction.

[0073] The vibration plate 35 is a plate-like member that can vibrate elastically. The vibration plate 35 is formed by laminating, for example, a first layer of silicon oxide (SiO2) and a second layer of zirconium oxide (ZrO2). In addition, the vibration plate 35 and the pressure chamber substrate 34 may be integrally formed by selectively removing a portion in the thickness direction of a region corresponding to the pressure chamber C in a plate-like member of a predetermined thickness. In addition, the vibration plate 35 may be formed in a single layer.

[0074] A plurality of piezoelectric elements 41 corresponding to different pressure chambers C are provided on the surface Fe2 of the vibration plate 35. The piezoelectric element 41 corresponding to each pressure chamber C overlaps with the pressure chamber C when viewed in a planar manner. Specifically, each piezoelectric element 41 is constructed by laminating a first electrode and a second electrode that are opposed to each other, and a piezoelectric layer formed between the two electrodes. Each piezoelectric element 41 is an energy generating element that generates energy to change the pressure of the ink in the pressure chamber C, thereby causing the ink in the pressure chamber C to be ejected from the nozzle N. The piezoelectric element 41 deforms itself by receiving a driving signal, thereby vibrating the vibration plate 35. When the vibration plate 35 vibrates, the pressure chamber C will expand and contract. The pressure chamber C expands and contracts, thereby applying pressure to the ink from the pressure chamber C. As a result, the ink is ejected from the nozzle N.

[0075] The protective substrate 43 is a plate-shaped component provided on the surface Fe2 of the vibration plate 35, which protects the plurality of piezoelectric elements 41 and strengthens the mechanical strength of the vibration plate 35. A plurality of piezoelectric elements 41 are accommodated between the protective substrate 43 and the vibration plate 35. In addition, a wiring substrate 44 is mounted on the surface Fe2 of the vibration plate 35. The wiring substrate 44 is a mounting component for electrically connecting the control unit 21 and the liquid ejection head 24. For example, a flexible wiring substrate 44 such as an FPC (Flexible Printed Circuit) or an FFC (Flexible Flat Cable) is preferably used. A driving circuit 45 for supplying a driving signal to each piezoelectric element 41 is mounted on the wiring substrate 44.

[0076] Next, the detailed structure of the independent flow passage P will be described. Figure 5 1 is a side view showing a structural example of the independent flow channel Pa, and is a diagram showing a state where the independent flow channel Pa and the independent flow channel Pb are relative to each other. Figure 5 and the following Figure 6 As shown, the shape of the independent flow channel Pa and the shape of the independent flow channel Pb are in a rotationally symmetric relationship around a symmetry axis parallel to the Z axis when viewed in a plan view.

[0077] like Figure 5 As shown, the independent flow channel Pa has a supply flow channel Ra1, a pressure chamber Ca1, a first communication flow channel Na1, a nozzle flow channel Nfa, a second communication flow channel Na2, a pressure chamber Ca2 and a discharge flow channel Ra2. The independent flow channel Pa is a flow channel in which these elements are integrally constituted, and is a flow channel in which the aforementioned elements are connected in the aforementioned order. Figure 5 As shown in the figure, the first portion Pa1 of the nozzle flow channel Nfa described later overlaps at least partially with the third portion Pb1 of the nozzle flow channel Nfb in the X1 direction. As shown in the figure, the third portion Pb1 completely overlaps with the first portion Pa1 in the X1 direction.

[0078] The supply flow channel Ra1 is a space formed on the connecting plate 33. Specifically, Figure 3 As shown, the supply flow channel Ra1 extends along the Z axis from the space O12 constituting the first common liquid chamber R1 to the surface Fc2 of the connecting plate 33. The end of the supply flow channel Ra1 connected to the space O12 is the end E1 of the independent flow channel Pa. The supply flow channel Ra1 is a flow channel that is connected to the pressure chamber Ca1 and guides the ink supplied from the first common liquid chamber R1 to the pressure chamber Ca1. The supply flow channel Ra1 is an example of a "first independent supply flow channel".

[0079] like Figure 3As shown, the first communication channel Na1 is a space that penetrates the communication plate 33. The first communication channel Na1 is a narrow and long channel along the Z axis. The first communication channel Na1 extends in the Z1 direction and is connected to the pressure chamber Ca1 and the nozzle channel Nfa. The first communication channel Na1 is a channel that guides the ink pressed out from the pressure chamber Ca1 to the nozzle channel Nfa.

[0080] The nozzle flow channel Nfa is a flow channel provided on the connecting plate 33 and extending in the X-axis direction. Figure 3 As shown, the nozzle flow channel Nfa is divided into a first part Pa1 and a second part Pa2. In the present embodiment, when observing from the nozzle flow channel Nfa, the side where the pressure chamber Ca1 and the pressure chamber Ca2 are located in the Z1 direction is set as the first side, and the side where the nozzle Na is located in the Z2 direction is set as the second side. The flow channel wall surface Sa1 on the first side of the first part Pa1 and the flow channel wall surface Sa2 on the first side of the second part Pa2 are located at different positions in the Z1 direction. In addition, the flow channel wall surface Sa3 on the second side of the first part Pa1 and the flow channel wall surface Sa4 on the second side of the second part Pa2 are located at the same position in the Z2 direction.

[0081] In other words, the first portion Pa1 has a flow channel wall surface Sa1 and a flow channel wall surface Sa3. In the Z1 direction, the flow channel wall surface Sa3 is located between the surface of the nozzle Na from which the ink is ejected and the flow channel wall surface Sa1. Similarly, the second portion Pa2 has a flow channel wall surface Sa2 and a flow channel wall surface Sa4. In the Z1 direction, the flow channel wall surface Sa4 is located between the surface of the nozzle Na from which the ink is ejected and the flow channel wall surface Sa2.

[0082] The first portion Pa1 is a flow channel that is located between the first connecting flow channel Na1 and the second portion Pa2 in the X-axis direction and extends in the X-axis direction. The first portion Pa1 is connected to the first connecting flow channel Na1 and the second portion Pa2 and is provided with a nozzle Na. The first portion Pa1 has an end E3 located in the X2 direction and an end E4 located in the X1 direction. The end of the nozzle flow channel Nfa connected to the first connecting flow channel Na1 is the end E3 of the first portion Pa1. That is, the first portion Pa1 includes the end of the nozzle flow channel Nfa located in the X2 direction. The first portion Pa1 is a flow channel that guides the ink supplied from the first connecting flow channel Na1 and not ejected from the nozzle Na to the second portion Pa2. As Figure 3 As shown, the width W1 of the first portion Pa1 in the X1 direction is greater than the width W3 of the second portion Pa2 in the X1 direction.

[0083] The second portion Pa2 is a flow channel that is located between the first portion Pa1 and the second connecting flow channel Na2 in the X-axis direction and extends a predetermined amount in the X-axis direction and the Z-axis direction. The second portion Pa2 is connected to the first portion Pa1 and the second connecting flow channel Na2, and has an end E5 located in the X2 direction and an end E6 located in the X1 direction. The end of the nozzle flow channel Nfa connected to the second connecting flow channel Na2 is the end E6 of the second portion Pa2, and the end E4 of the first portion Pa1 connected to the second portion Pa2 is the end E5 of the second portion Pa2. That is, the second portion Pa2 includes the end of the nozzle flow channel Nfa located in the X1 direction. The second portion Pa2 is a flow channel that guides the ink supplied from the first portion Pa1 to the second connecting flow channel Na2.

[0084] like Figure 3 As shown, the width W3 of the second portion Pa2 in the X1 direction is smaller than the width W1 of the first portion Pa1 in the X1 direction. Figure 3 As shown, the width W10 of the second part Pa2 in the Z1 direction is greater than the width W9 of the first part Pa1 in the Z1 direction. As a result, structural crosstalk can be reduced. The details will be described below. In addition, the aforementioned "structural crosstalk" refers to the phenomenon that the vibration caused by the change in the internal pressure of an independent flow channel on one side is transmitted to the independent flow channel on the other side, thereby reducing the ejection characteristics of the nozzle connected to the independent flow channel. The definition of the structural crosstalk is the same in the following description.

[0085] The second communication channel Na2 is a space that penetrates the communication plate 33. The second communication channel Na2 is a long and narrow channel along the Z axis. The second communication channel Na2 extends in the Z1 direction and communicates with the pressure chamber Ca2 and the nozzle channel Nfa. The second communication channel Na2 is a channel that guides the ink supplied from the second portion Pa2 to the pressure chamber Ca2.

[0086] The discharge flow channel Ra2 is a space formed on the connecting plate 33. Specifically, the discharge flow channel Ra2 extends along the Z axis from the space O22 constituting the second common liquid chamber R2 to the surface Fc2 of the connecting plate 33. The end of the discharge flow channel Ra2 connected to the space O22 is the end E2 of the independent flow channel Pa. The discharge flow channel Ra2 is a flow channel that is connected to the pressure chamber Ca2 and guides the ink pressed out of the pressure chamber Ca2 to the second common liquid chamber R2. The discharge flow channel Ra2 is an example of a "first independent discharge flow channel".

[0087] In the above structure, when the liquid ejection device 100 is working, the liquid ejection head 24 circulates the ink and ejects the ink at the same time. Specifically, the ink from the liquid container 12 is supplied to the first common liquid chamber R1 via the supply flow path 265. Then, the driving unit including the drive circuit 45 outputs the driving signal for driving the piezoelectric element 41 to the piezoelectric element 41 on the pressure chamber Ca1 side and the piezoelectric element 41 on the pressure chamber Ca2 side, thereby driving the piezoelectric element 41 on the pressure chamber Ca1 side and the piezoelectric element 41 on the pressure chamber Ca2 side at the same time. As a result, the ink supplied to the first common liquid chamber R1 is ejected from the nozzle Na. In addition, the ink supplied to the first part Pa1 that is not ejected from the nozzle Na is supplied to the second common liquid chamber R2 via the discharge flow path Ra2. As understood from the above description, the first part Pa1 is the flow path on the upstream side of the nozzle flow path Nfa, and the second part Pa2 is the flow path on the downstream side of the nozzle flow path Nfb. The piezoelectric element 41 on the pressure chamber Ca1 side described above is an example of a “first energy generating element”, and the piezoelectric element 41 on the pressure chamber Ca2 side is an example of a “second energy generating element”.

[0088] Figure 6 FIG. 1 is a side view showing an example of the structure of the independent flow channel Pb, and is a diagram showing the relative state of the independent flow channel Pa and the independent flow channel Pb. The independent flow channel Pb is a structure obtained by inverting the independent flow channel Pa by 180 degrees. Figure 4 As shown, the width W9 of the fourth portion Pb2 in the Z1 direction is smaller than the width W10 of the third portion Pb1 in the Z1 direction. In addition, the width W7 of the fourth portion Pb2 in the X1 direction is larger than the width W5 of the third portion Pb1 in the X1 direction. In addition, the width W9 of the fourth portion Pb2 in the Z1 direction is the same as the width W9 of the first portion Pa1 in the Z1 direction, and the width W10 of the third portion Pb1 in the Z1 direction is the same as the width W10 of the second portion Pa2 in the Z1 direction. In addition, the width W5 of the third portion Pb1 in the X1 direction is the same as the width W3 of the second portion Pa2 in the X1 direction, and the width W7 of the fourth portion Pb2 in the X1 direction is the same as the width W1 of the first portion Pa1 in the X1 direction. Specifically, as Figure 6 As shown, the independent flow channel Pb has a supply flow channel Rb1, a pressure chamber Cb1, a third communication flow channel Nb1, a nozzle flow channel Nfb, a fourth communication flow channel Nb2, a pressure chamber Cb2, and a discharge flow channel Rb2. The nozzle flow channel Nfb has a third part Pb1 and a fourth part Pb2. The independent flow channel Pb is a flow channel in which these elements are integrally formed, and is a flow channel in which the aforementioned elements are connected in the aforementioned order. Figure 6As shown in FIG. 1 , the second portion Pa2 and the fourth portion Pb2 at least partially overlap in the X1 direction. As shown in the figure, the second portion Pa2 completely overlaps with the fourth portion Pb2 in the X1 direction.

[0089] The description of the structure of the independent flow channel Pa is also valid as the description of the elements constituting the independent flow channel Pb by replacing the suffix a of the symbols of the elements constituting the independent flow channel Pa with the suffix b. In addition, the supply flow channel Rb1 is an example of the "second independent supply flow channel", and the discharge flow channel Rb2 is an example of the "second independent discharge flow channel".

[0090] In the above structure, the liquid ejection head 24 supplies the ink from the liquid container 12 to the first common liquid chamber R1 via the supply flow path 265. Then, the driving unit including the drive circuit 45 outputs a driving signal for driving the piezoelectric element 41 to the piezoelectric element 41 on the pressure chamber Cb1 side and the piezoelectric element 41 on the pressure chamber Cb2 side, thereby driving the piezoelectric element 41 on the pressure chamber Cb1 side and the piezoelectric element 41 on the pressure chamber Cb2 side at the same time. As a result, the ink supplied to the first common liquid chamber R1 is ejected from the nozzle Nb. In addition, the ink supplied to the third part Pb1 that is not ejected from the nozzle Nb is supplied to the second common liquid chamber R2 via the discharge flow path Rb2. As understood from the above description, the third part Pb1 is a flow path on the upstream side of the nozzle flow path Nfb, and the fourth part Pb2 is a flow path on the downstream side of the nozzle flow path Nfb.

[0091] The liquid ejection head 24 of this embodiment can suppress the thickening of the ink and the precipitation of the components near the nozzles Na and Nb by circulating the ink when the ink is ejected, thereby preventing the deterioration of the ejection characteristics of the ink. As a result, the ejection characteristics of the ink can be maintained substantially constant, and the deviation of the ejection characteristics can be suppressed, thereby improving the ejection quality of the ink. In addition, the aforementioned "ejection characteristics" refers to, for example, the ejection amount or ejection speed of the ink.

[0092] Figure 7 for Figure 5 as well as Figure 6 The cross-sectional view of the dd line, Figure 8 for Figure 5 as well as Figure 6 The cross-sectional view of the cc line. Figure 5 to Figure 7 As shown in FIG. 1 , in the cross-sectional view of line dd, the first portion Pa1 and the third portion Pb1 are arranged alternately along the Y-axis direction. Figure 5 , Figure 6 as well as Figure 8 As shown, in the cross-sectional view taken along line cc, the second portion Pa2 and the fourth portion Pb2 are alternately arranged along the Y-axis direction.

[0093] like Figure 7 as well as Figure 8 As shown, the width of the first part Pa1 and the fourth part Pb2 in the Y-axis direction is W2, and the width in the Z-axis direction is W9. In addition, the width of the second part Pa2 and the third part Pb1 in the Y-axis direction is W4, and the width in the Z-axis direction is W10. The width W4 is the same as the width W2, and the width W10 is greater than the width W9.

[0094] Here, since the flow channel cross-sectional area when the nozzle flow channel Nfa is observed from the X-axis direction is small at W2×W9 in the first portion Pa1 and large at W4×W10 in the second portion Pa2, the flow channel resistance of the nozzle flow channel Nfa as a whole becomes small. Similarly, since the flow channel cross-sectional area when the nozzle flow channel Nfb is observed from the X-axis direction is small at W2×W9 in the fourth portion Pb2 and large at W4×W10 in the third portion Pb1, the flow channel resistance of the nozzle flow channel Nfb as a whole becomes small.

[0095] In addition, when focusing on Figure 7 In the cross section of the dd line, the first portion Pa1 having a width W9 in the Z-axis direction and the third portion Pb1 having a width W10 larger than W9 in the Z-axis direction are arranged adjacent to each other in the Y-axis direction. Figure 7 As shown, although the third portion Pb1 exists within the range Eb1, the first portion Pa1 does not exist. In other words, although flow channels exist at positions adjacent to each other in the Y-axis direction within the range Eb2 whose width in the Y-axis direction is the difference between W10 and W9, there are no flow channels at positions adjacent to each other in the Y-axis direction within the range Eb1. Therefore, even if vibrations accompanying the flow of ink are generated in the third portion Pb1 within the range Eb1, since the first portion Pa1 does not exist at the overlapping position in the Z-axis direction, the vibrations are difficult to be transmitted to the first portion Pa1, thereby reducing the impact on the ejection of the nozzle Na. In other words, structural crosstalk is difficult to occur. Figure 8 Similarly, in the cross section of the dd line, since the fourth part Pb2 does not exist at a position overlapping with the second part Pa2 in the range Ea1 in the Z-axis direction, the vibration from the second part Pa2 in the range Ea1 is difficult to be transmitted to the fourth part Pb2, and structural crosstalk is difficult to occur.

[0096] As described above, according to the present embodiment, it is possible to reduce structural crosstalk while suppressing an increase in the flow channel resistance of the nozzle flow channel Nfa and the nozzle flow channel Nfb.

[0097] 1-1. Comparative Example 1

[0098] Fig. 9 The comparative example of the present invention involves Figure 5 as well as Figure 6 The cross-sectional view of the dd line, Fig.10 The comparative example involves Figure 5 as well as Figure 6 In Comparative Example 1, the width of the first portion Pa1 and the fourth portion Pb2 in the Z-axis direction is W11, and other than this, the same as the first embodiment. Fig. 9 As shown, the width W11 is the same as the width W10, but is larger than Figure 7 as well as Figure 8 Width W9 shown.

[0099] In Comparative Example 1, Fig. 9 From the cross section of the dd line, it can be seen that the first part Pa1 and the third part Pb1 having a width of W11 in the Z-axis direction are adjacent to each other in the Y-axis direction. That is, unlike the first embodiment, there is no range Eb1 where the flow channel is not provided at positions adjacent to each other in the Y-axis direction. On the other hand, relative to the difference between the width W10 and the width W9 in the first embodiment, the width in the Y-axis direction of the range Eb2 where the flow channel exists at positions adjacent to each other becomes larger as W10 in Comparative Example 1. Therefore, when vibration occurs in the third part Pb1, the influence on the ejection of the nozzle Na provided on the first part Pa1 becomes greater. That is, structural crosstalk becomes more likely to occur. The aforementioned principle of structural crosstalk becoming more likely to occur is explained in detail in the following sections. Fig.10 The same is true for the cross section of the cc line.

[0100] As described above, when the structure according to Comparative Example 1 is adopted in the liquid ejection head 24 , there is a possibility that structural crosstalk may occur significantly.

[0101] 1-2. Comparative Example 2

[0102] Fig.11 Other comparative examples of the present invention Figure 5 as well as Figure 6 The cross-sectional view of the dd line, Fig.12 The comparative example involves Figure 5 as well as Figure 6 In Comparative Example 2, the width of the second portion Pa2 and the third portion Pb1 in the Z-axis direction is W12, and except for this point, the structures are the same as those of the first embodiment. Fig.11 As shown, the width W12 is the same as the width W9 and is greater than Figure 7 as well as Figure 8 Width W10 shown.

[0103] In Comparative Example 2, Fig.11 as well as Fig.12It can be seen that the cross-sectional area of ​​the nozzle flow channel Nfa when viewed from the X-axis direction is W2×W9 in the first portion Pa1, and W4×W12 in the second portion Pa2. Therefore, the cross-sectional areas of the flow channels of the first portion Pa1 and the second portion Pa2 are reduced, and thus the flow channel resistance of the nozzle flow channel Nfa as a whole is increased. The same is true for the nozzle flow channel Nfb due to the aforementioned principle.

[0104] Thus, in Comparative Example 2, it can be seen that the flow channel resistance increases.

[0105] 2. Second Implementation

[0106] Fig.13 Schematic diagram showing the flow path structure in the liquid ejection head 24 according to the second embodiment when the liquid ejection head 24 is viewed from the Z-axis direction. Hereinafter, the same reference numerals are used for the same structures as those in the first embodiment, and detailed description thereof will be omitted or simplified.

[0107] In the second embodiment, the width of the first portion Pa1 and the fourth portion Pb2 in the Y-axis direction is W13, and the width of the second portion Pa2 and the third portion Pb1 in the Y-axis direction is W14. Except for the above two points, the structures are the same as those of the first embodiment. The width W13 is greater than Figure 2 The width W2 shown, the width W14 is less than Figure 2 Width W4 shown.

[0108] In the first embodiment, although the increase in the flow resistance of the nozzle flow channel Nfa as a whole can be suppressed by increasing the flow channel cross-sectional area of ​​the second portion Pa2 to a certain extent, a portion where the flow channel resistance increases may appear when the flow channel cross-sectional area in the first portion Pa1 is observed. Figure 7 As shown, since it is smaller than W2×W9, the local flow path resistance in the first portion Pa1 will be slightly increased, and this portion may become a rate limiting factor and affect the flow path resistance of the entire nozzle flow path Nfa.

[0109] Therefore, in the second embodiment, the width W13 of the first portion Pa1 and the fourth portion Pb2 in the Y-axis direction is made larger than that of the first embodiment. This can reduce the flow channel resistance of the first portion Pa1 and the fourth portion Pb2.

[0110] On the other hand, when only the width of the first part Pa1 and the fourth part Pb2 in the Y-axis direction is increased, for example, the connecting plate 33 between the first part Pa1 and the third part Pb1 will become thinner and structural crosstalk will easily occur. Therefore, in the second embodiment, the width W14 of the second part Pa2 and the third part Pb1 in the Y-axis direction is made smaller than that in the first embodiment. Thus, the thickness of the connecting plate 33 between the first part Pa1 and the third part Pb1 is set to the same degree as that in the first embodiment, so that the occurrence of structural crosstalk can be suppressed. In addition, since the width of the second part Pa2 and the third part Pb1 in the Z-axis direction is W10 and is relatively large, even if the width in the Y-axis direction is set to W14 and slightly reduced, the local flow resistance will not increase much. Therefore, compared with the first embodiment, in the second embodiment, the increase in local flow resistance can also be suppressed.

[0111] 3. Third Implementation

[0112] Fig.14 Schematic diagram of the flow path structure in the liquid ejection head 24 according to the third embodiment when the liquid ejection head 24 is viewed from the Z-axis direction. Fig.15 for Fig.14 The cross-sectional view of line aa, Fig.16 for Fig.14 Hereinafter, the same reference numerals are used for the same structures as those in the first embodiment and the second embodiment, and the detailed description thereof will be omitted or simplified.

[0113] The liquid ejection head 24 of the third embodiment is different from the first embodiment in that the nozzle Na is provided in the second portion Pa2 of the independent flow channel Pa, and the nozzle Nb is provided in the third portion Pb1 of the independent flow channel Pb.

[0114] In the third embodiment, the independent flow channel Pa and the independent flow channel Pb are in a relationship that is reversed by 180° with the Z axis as the center, and the nozzle flow channel Nfa overlaps with the nozzle flow channel Nfb when viewed from the side in the Y-axis direction (hereinafter referred to as the side view). Thus, similarly to the first embodiment, the second portion Pa2 of the independent flow channel Pa has a structure having a portion that completely overlaps with the fourth portion Pb2 when viewed from the side and a portion that does not overlap. In addition, the third portion Pb1 of the independent flow channel Pb has a structure having a portion that completely overlaps with the first portion Pa1 when viewed from the side and a portion that does not overlap. Therefore, in the liquid ejection head 24 of the third embodiment, the same effects as those of the first embodiment are obtained.

[0115] 4. Fourth Implementation

[0116] Fig.17The fourth embodiment involves Fig.14 The cross-sectional view of line aa, Fig.18 The fourth embodiment involves Fig.14 Hereinafter, the same reference numerals are used for the same structures as those in the first to third embodiments, and the description thereof will be omitted or simplified.

[0117] The structures of the second portion Pa2 and the third portion Pb1 of the liquid ejection head 24 of the fourth embodiment are different from those of the first embodiment. Specifically, the second portion Pa2 of the fourth embodiment is composed of a flow channel Pa21 provided on the connecting plate 33 and extending a predetermined amount in the X-axis direction, and a flow channel Pa22 provided on the nozzle plate 31 and extending a predetermined amount in the X-axis direction. The flow channel Pa22 is provided on the nozzle plate 31 between the flow channel Pa21 and the nozzle Na, and communicates with the flow channel Pa21 and the nozzle Na.

[0118] Similarly, the third portion Pb1 of the third embodiment is composed of a flow channel Pb11 provided on the connecting plate 33 and extending a predetermined amount in the X-axis direction, and a flow channel Pb12 provided on the nozzle plate 31 and extending a predetermined amount in the X-axis direction. The flow channel Pb12 is provided on the nozzle plate 31 between the flow channel Pa11 and the nozzle Nb, and communicates with the flow channel Pa11 and the nozzle Nb.

[0119] Here, if Fig.17 As shown, the liquid ejection head 24 of the fourth embodiment is provided with a flow channel Pa22 on the nozzle plate 31. Thus, when the side where the pressure chamber Ca1 and the pressure chamber Ca2 are located in the Z1 direction is set as the first side, and the side where the nozzle Na is located in the Z2 direction is set as the second side when viewed from the nozzle flow channel Nfa, the flow channel wall surface Sa7 on the second side of the first portion Pa1 and the flow channel wall surface Sa8 on the second side of the second portion Pa2 are located at different positions in the Z2 direction, and the flow channel wall surface Sa5 on the first side of the first portion Pa1 and the flow channel wall surface Sa6 on the first side of the second portion Pa2 are located at the same position in the Z1 direction.

[0120] In other words, the first portion Pa1 has a flow channel wall surface Sa5 and a flow channel wall surface Sa7. In the Z1 direction, the flow channel wall surface Sa7 is located between the surface of the nozzle Na from which the ink is ejected and the flow channel wall surface Sa5. Similarly, the second portion Pa2 has a flow channel wall surface Sa6 and a flow channel wall surface Sa8. In the Z1 direction, the flow channel wall surface Sa8 is located between the surface of the nozzle Na from which the ink is ejected and the flow channel wall surface Sa6.

[0121] In addition, when observing from the nozzle flow channel Nfb, with the side where the pressure chamber Cb1 and the pressure chamber Cb2 are located in the Z1 direction as the first side, and the side where the nozzle Nb is located in the Z1 direction as the second side, the flow channel wall surface Sb7 on the second side of the third part Pb1 and the flow channel wall surface Sb8 on the second side of the fourth part Pb2 are in different positions in the Z1 direction, and the flow channel wall surface Sb5 on the first side of the third part Pb1 and the flow channel wall surface Sb6 on the first side of the fourth part Pb2 are in the same position in the Z1 direction.

[0122] In other words, the third portion Pb1 has a flow channel wall surface Sb5 and a flow channel wall surface Sb7. In the Z1 direction, the flow channel wall surface Sb7 is located between the surface of the nozzle Nb from which the ink is ejected and the flow channel wall surface Sb5. Similarly, the fourth portion Pb2 has a flow channel wall surface Sb6 and a flow channel wall surface Sb8. In the Z1 direction, the flow channel wall surface Sb8 is located between the surface of the nozzle Nb from which the ink is ejected and the flow channel wall surface Sb6.

[0123] In the fourth embodiment, the independent flow channel Pa and the independent flow channel Pb are mutually reversed by 180° with the Z axis as the center, and the nozzle flow channel Nfa overlaps with the nozzle flow channel Nfb when viewed from the side. According to this configuration, the flow channel Pa21 in the second portion Pa2 of the independent flow channel Pa completely overlaps with the fourth portion Pb2 when viewed from the side, and the flow channel Pa22 does not overlap with the fourth portion Pb2 when viewed from the side, and all of them overlap with the nozzle plate 31. Similarly, the flow channel Pb11 in the third portion Pb1 of the independent flow channel Pb completely overlaps with the first portion Pa1 when viewed from the side, and the flow channel Pb12 does not overlap with the first portion Pa1 when viewed from the side, and all of them overlap with the nozzle plate 31.

[0124] That is, the flow channel Pa22 is covered from three directions, namely, the Z1 direction, the Y1 direction, and the Y2 direction, by the nozzle plate 31, and the flow channel Pb12 is also covered from three directions, namely, the Z1 direction, the Y1 direction, and the Y2 direction, by the nozzle plate 31. Thus, in the liquid ejection head 24 of the fourth embodiment, the same effects as those of the first embodiment are obtained.

[0125] 5. Fifth Implementation

[0126] Fig.19 The fifth embodiment involves Fig.14 The cross-sectional view of line aa, Fig. 20 The fifth embodiment involves Fig.14 Hereinafter, the same reference numerals are used for the same structures as those in the first to fourth embodiments, and the description thereof will be omitted or simplified.

[0127] The structures of the second part Pa2 and the third part Pb1 of the liquid ejection head 24 of the fifth embodiment are different from those of the first embodiment. Specifically, the second part Pa2 of the fifth embodiment is composed of a flow channel Pa23 and a flow channel Pa24. The flow channel Pa23 is a flow channel that is located between the first part Pa1 and the second connecting flow channel Na2 in the X-axis direction and extends a predetermined amount in the X-axis direction and the Z-axis direction. The flow channel Pa23 is a flow channel that is connected to the first part Pa1 and the second connecting flow channel Na2. The flow channel Pa24 is arranged on the nozzle plate 31 and extends a predetermined amount in the X-axis direction. The flow channel Pa24 is arranged on the nozzle plate 31 between the flow channel Pa23 and the nozzle Na, and is connected to the flow channel Pa23 and the nozzle Na.

[0128] Similarly, the third portion Pb1 of the fifth embodiment is composed of a flow channel Pb13 and a flow channel Pb14. The flow channel Pb13 is located between the fourth portion Pb2 and the third communicating flow channel Nb1 in the X-axis direction and extends a predetermined amount in the X-axis direction and the Z-axis direction. The flow channel Pb13 is a flow channel that communicates with the fourth portion Pb2 and the third communicating flow channel Nb1. The flow channel Pb14 is provided on the nozzle plate 31 and extends a predetermined amount in the X-axis direction. The flow channel Pb14 is provided on the nozzle plate 31 between the flow channel Pb13 and the nozzle Nb and communicates with the flow channel Pb13 and the nozzle Nb.

[0129] The width W10 of the second portion Pa2 in the fifth embodiment in the Z1 direction is larger than three times the width W9 of the first portion Pa1 in the Z1 direction. Similarly, the width W10 of the third portion Pb1 in the fifth embodiment is larger than three times the width W9 of the fourth portion Pb2.

[0130] In the fifth embodiment, the independent flow channel Pa and the independent flow channel Pb are mutually reversed by 180° with the Z axis as the center, and the nozzle flow channel Nfa overlaps with the nozzle flow channel Nfb when viewed from the side. As a result, the flow channel Pa23 in the second portion Pa2 of the independent flow channel Pa has a structure having a portion that completely overlaps with the fourth portion Pb2 and a portion that does not overlap when viewed from the side, and the flow channel Pa24 does not overlap with the fourth portion Pb2 when viewed from the side, and all of it overlaps with the nozzle plate 31.

[0131] Similarly, the flow channel Pb13 in the third portion Pb1 of the independent flow channel Pb has a structure having a portion that completely overlaps with the first portion Pa1 when viewed from the side and a portion that does not overlap, and the flow channel Pb14 does not overlap with the first portion Pa1 when viewed from the side, and all of it overlaps with the nozzle plate 31. Thus, in the liquid ejection head 24 of the fifth embodiment, the same effects as those of the first embodiment are obtained.

[0132] 6. Sixth Implementation

[0133] Fig.21 Schematic diagram of the flow path structure in the liquid ejection head 24 according to the sixth embodiment when the liquid ejection head 24 is viewed from the Z-axis direction. Fig. 22 for Fig.21 The cross-sectional view of line aa, Fig.23 for Fig.21 Hereinafter, the same reference numerals are used for the same structures as those in the first to fifth embodiments, and the detailed description thereof will be omitted or simplified.

[0134] The arrangement positions of the nozzles Na and Nb of the liquid ejection head 24 of the sixth embodiment are different from those of the first embodiment. Fig. 22 As shown in FIG. 1 , the nozzle Na of the sixth embodiment is disposed at the center of the nozzle plate 31 in the X-axis direction. As shown in the figure, the nozzle Na is disposed near the end of the first portion Pa1 in the X1 direction. Fig.23 As shown in FIG. 1 , the nozzle Nb of the sixth embodiment is provided at the center in the X-axis direction of the nozzle plate 31. As shown in the figure, the nozzle Nb is provided near the end portion of the fourth portion Pb2 in the X2 direction.

[0135] like Fig.21 As shown in FIG. 1 , the plurality of nozzles Na and the plurality of nozzles Nb of the sixth embodiment are respectively located on the same straight line and constitute a nozzle row L. The nozzle row L is a collection of the plurality of nozzles Na and the plurality of nozzles Nb arranged on a straight line along the Y axis. Fig.21 As shown in FIG. 1 , nozzle Na and nozzle Nb are located at the same position in the X1 direction. Also, as shown in the figure, nozzles N including nozzle Na and nozzle Nb are arranged at a pitch θ. Pitch θ is the distance between the center of nozzle Na and the center of nozzle Nb in the Y-axis direction.

[0136] In the sixth embodiment, the independent flow channel Pa and the independent flow channel Pb are in a relationship that is reversed by 180° with the Z axis as the center, and the nozzle flow channel Nfa overlaps the nozzle flow channel Nfb when viewed from the side. Thus, similarly to the first embodiment, the second portion Pa2 of the independent flow channel Pa has a structure that has a portion that completely overlaps with the fourth portion Pb2 when viewed from the side and a portion that does not overlap. In addition, the third portion Pb1 of the independent flow channel Pb has a structure that has a portion that completely overlaps with the first portion Pa1 when viewed from the side and a portion that does not overlap. Therefore, in the liquid ejection head 24 of the sixth embodiment, the same effects as those of the first embodiment are obtained.

[0137] 7. Seventh Implementation Method

[0138] Fig.24FIG. 2 is a schematic diagram of the flow path structure in the liquid ejection head 24 according to the seventh embodiment when the liquid ejection head 24 is viewed from the Z-axis direction. Fig.24 As shown in the example, a plurality of nozzles N (Na, Nb) are formed on the surface of the liquid ejection head 24 facing the medium 11. The plurality of nozzles N are arranged along the Y axis. Ink is ejected from each of the plurality of nozzles N along the Z axis direction. That is, the Z axis corresponds to the direction in which the ink is ejected from each nozzle N.

[0139] The plurality of nozzles N in the seventh embodiment are divided into a first nozzle column La and a second nozzle column Lb. The first nozzle column La is a collection of a plurality of nozzles Na arranged in a straight line along the Y axis. Similarly, the second nozzle column Lb is a collection of a plurality of nozzles Nb arranged in a straight line along the Y axis. The first nozzle column La and the second nozzle column Lb are arranged at a predetermined interval in the X-axis direction. In addition, the position of each nozzle Na in the Y-axis direction is different from the position of each nozzle Nb in the Y-axis direction. Fig.24 As illustrated, a plurality of nozzles N including nozzles Na and nozzles Nb are arranged at a pitch (period) θ. The pitch θ is the distance between the centers of nozzles Na and nozzles Nb in the Y-axis direction.

[0140] like Fig.24 As shown in the example, an independent flow channel array 25 is provided on the liquid ejection head 24. The independent flow channel array 25 is a collection of multiple independent flow channels P (Pa, Pb) corresponding to different nozzles N. The multiple independent flow channels P are respectively flow channels connected to the nozzles N corresponding to the independent flow channels P. Each independent flow channel P extends along the X axis. The independent flow channel array 25 is composed of multiple independent flow channels P arranged along the Y axis. In addition, although Fig.24 In the figure, each independent flow channel P is illustrated as a simple straight line for convenience of explanation, but the actual shape of each independent flow channel P will be described below.

[0141] Each independent flow channel P includes a pressure chamber C (Ca, Cb). The pressure chamber C in each independent flow channel P is a space for storing ink ejected from the nozzle N connected to the independent flow channel P. That is, the ink is ejected from the nozzle N by the change in the pressure of the ink in the pressure chamber C.

[0142] like Fig.24 As shown in the example, a first common liquid chamber R1 and a second common liquid chamber R2 are provided in the liquid ejection head 24. The first common liquid chamber R1 and the second common liquid chamber R2 extend in the Y-axis direction across the entire area of ​​the range where the plurality of nozzles N are distributed. When viewed in a plan view, the independent flow channel array 25 and the plurality of nozzles N are located between the first common liquid chamber R1 and the second common liquid chamber R2.

[0143] A plurality of independent flow channels P are commonly connected to the first common liquid chamber R1. Specifically, an end E1 of each independent flow channel P located in the X2 direction is connected to the first common liquid chamber R1. In addition, a plurality of independent flow channels P are commonly connected to the second common liquid chamber R2. Specifically, an end E2 of each independent flow channel P located in the X1 direction is connected to the second common liquid chamber R2. As understood from the above description, each independent flow channel P enables the first common liquid chamber R1 and the second common liquid chamber R2 to communicate with each other. The ink supplied from the first common liquid chamber R1 to each independent flow channel P is ejected from the nozzle N corresponding to the independent flow channel P. In addition, the portion of the ink supplied from the first common liquid chamber R1 to each independent flow channel P that is not ejected from the nozzle N is discharged to the second common liquid chamber R2.

[0144] like Fig.24 As illustrated, the liquid ejection device 100 of the seventh embodiment includes a circulation mechanism 26. The circulation mechanism 26 is a mechanism for returning the ink discharged from each independent flow path P to the second common liquid chamber R2 to the first common liquid chamber R1. Specifically, the circulation mechanism 26 includes a first supply pump 261, a second supply pump 262, a storage container 263, a circulation flow path 264, and a supply flow path 265.

[0145] The first supply pump 261 is a pump that supplies the ink stored in the liquid container 12 to the storage container 263. The storage container 263 is a sub-tank that temporarily stores the ink supplied from the liquid container 12. The circulation channel 264 is a channel that connects the second common liquid chamber R2 and the storage container 263. In addition to the ink stored in the liquid container 12 supplied from the first supply pump 261, the storage container 263 is also supplied with the ink discharged from each independent flow channel P to the second common liquid chamber R2 through the circulation channel 264. The second supply pump 262 is a pump that sends out the ink stored in the storage container 263. The ink sent out from the second supply pump 262 is supplied to the first common liquid chamber R1 through the supply channel 265.

[0146] The plurality of independent flow channels P of the independent flow channel array 25 include a plurality of independent flow channels Pa and a plurality of independent flow channels Pb. The plurality of independent flow channels Pa are independent flow channels P that are connected to one nozzle Na of the first nozzle array La. The plurality of independent flow channels Pb are independent flow channels P that are connected to one nozzle Nb of the second nozzle array Lb. The independent flow channels Pa and the independent flow channels Pb are alternately arranged along the Y axis. That is, the independent flow channels Pa and the independent flow channels Pb are adjacent to each other in the Y axis direction.

[0147] As understood from the above description, the plurality of pressure chambers Ca corresponding to the different nozzles Na of the first nozzle array La are arranged in a straight line along the Y axis. Similarly, the plurality of pressure chambers Cb corresponding to the different nozzles Nb of the second nozzle array Lb are arranged in a straight line along the Y axis. The arrangement of the plurality of pressure chambers Ca and the arrangement of the plurality of pressure chambers Cb are arranged in a manner spaced apart by a predetermined interval in the X-axis direction. The position of each pressure chamber Ca in the Y-axis direction is different from the position of each pressure chamber Cb in the Y-axis direction.

[0148] Hereinafter, the specific structure of the liquid ejection head 24 according to the seventh embodiment will be described in detail. Fig.25 for Fig.24 The cross-sectional view of line aa, Fig.26 for Fig.24 The cross section through the independent flow channel Pa is Fig.25 As shown in the figure, the cross section through the independent flow channel Pb is Fig.26 As shown in the figure.

[0149] like Fig.25 as well as Fig.26 As shown in the example, the liquid ejection head 24 includes a flow channel structure 30, a plurality of piezoelectric elements 41, a frame portion 42, a protective substrate 43, and a wiring substrate 44. The flow channel structure 30 is a structure in which a flow channel including a first common liquid chamber R1, a second common liquid chamber R2, a plurality of independent flow channels P, and a plurality of nozzles N is formed.

[0150] The flow channel structure 30 is a structure in which the nozzle plate 31, the connecting plate 33, the pressure chamber substrate 34 and the vibration plate 35 are laminated in the above order in the Z1 direction. The components constituting the flow channel structure 30 are manufactured by processing a silicon single crystal substrate using semiconductor manufacturing technology, for example.

[0151] The nozzle plate 31 has a plurality of nozzles N. Each of the plurality of nozzles N is a circular through hole through which ink passes. The nozzle plate 31 of the first embodiment is a plate-like member including a surface Fa1 located in the Z2 direction and a surface Fa2 located in the Z1 direction.

[0152] Fig. 27 is a cross-sectional view of an arbitrary nozzle N after enlarging it. Fig. 27As shown in the example, one nozzle N includes a first section n1 and a second section n2. The first section n1 is a section including an opening for ejecting ink in the nozzle N. That is, the first section n1 is a section continuous with the surface Fa1 of the nozzle plate 31. On the other hand, the second section n2 is a section between the first section n1 and the independent flow channel P. That is, the second section n2 is a section continuous with the surface Fa2 of the nozzle plate 31. The second section n2 has a larger diameter than the first section n1.

[0153] Fig.25 as well as Fig.26 The connecting plate 33 shown is a plate-shaped member including a surface Fc1 located in the Z2 direction and a surface Fc2 located in the Z1 direction.

[0154] The pressure chamber substrate 34 is a plate-shaped member including a surface Fd1 located in the Z2 direction and a surface Fd2 located in the Z1 direction. The vibration plate 35 is a plate-shaped member including a surface Fe1 located in the Z2 direction and a surface Fe2 located in the Z1 direction.

[0155] Each component constituting the flow channel structure 30 is formed into a rectangular shape that is long and narrow in the Y-axis direction, and is bonded to each other by, for example, an adhesive. For example, the surface Fa2 of the nozzle plate 31 is bonded to the surface Fc1 of the connecting plate 33. In addition, the surface Fc2 of the connecting plate 33 is bonded to the surface Fd1 of the pressure chamber substrate 34, and the surface Fd2 of the pressure chamber substrate 34 is bonded to the surface Fe1 of the vibration plate 35.

[0156] A space O12 and a space O22 are formed on the connecting plate 33. The space O12 and the space O22 are respectively long and narrow openings in the Y-axis direction. A vibration absorbing body 361 for blocking the space O12 and a vibration absorbing body 362 for blocking the space O22 are provided on the surface Fc1 of the connecting plate 33. The vibration absorbing body 361 and the vibration absorbing body 362 are layered components formed of elastic material.

[0157] The frame portion 42 is a frame for storing ink. The frame portion 42 is joined to the surface Fc2 of the connecting plate 33. A space O13 connected to the space O12 and a space O23 connected to the space O22 are formed in the frame portion 42. The space O13 and the space O23 are respectively long and narrow spaces in the Y-axis direction. The space O12 and the space O13 are connected to each other to form the first common liquid chamber R1. Similarly, the space O22 and the space O23 are connected to each other to form the second common liquid chamber R2. The vibration absorbing body 361 constitutes the wall surface of the first common liquid chamber R1 and absorbs the pressure fluctuation of the ink in the first common liquid chamber R1. The vibration absorbing body 362 constitutes the wall surface of the second common liquid chamber R2 and absorbs the pressure fluctuation of the ink in the second common liquid chamber R2.

[0158] The frame portion 42 is formed with a supply port 421 and a discharge port 422. The supply port 421 is a pipe communicating with the first common liquid chamber R1, and is connected to the supply flow path 265 of the circulation mechanism 26. The ink sent from the second supply pump 262 to the supply flow path 265 is supplied to the first common liquid chamber R1 via the supply port 421. On the other hand, the discharge port 422 is a pipe communicating with the second common liquid chamber R2, and is connected to the circulation flow path 264 of the circulation mechanism 26. The ink in the second common liquid chamber R2 is supplied to the circulation flow path 264 via the discharge port 422.

[0159] A plurality of pressure chambers C (Ca, Cb) are formed on the pressure chamber substrate 34. Each pressure chamber C is a gap connecting the surface Fc2 of the plate 33 and the surface Fe1 of the vibration plate 35. Each pressure chamber C is formed in a strip shape along the X axis in plan view.

[0160] The vibration plate 35 is a plate-like member that can vibrate elastically. The vibration plate 35 is formed by laminating, for example, a first layer of silicon oxide (SiO2) and a second layer of zirconium oxide (ZrO2). In addition, the vibration plate 35 and the pressure chamber substrate 34 may be integrally formed by selectively removing a portion in the thickness direction of a region corresponding to the pressure chamber C in a plate-like member of a predetermined thickness. In addition, the vibration plate 35 may be formed in a single layer.

[0161] A plurality of piezoelectric elements 41 corresponding to different pressure chambers C are provided on the surface Fe2 of the vibration plate 35. The piezoelectric element 41 corresponding to each pressure chamber C overlaps with the pressure chamber C when viewed in a planar manner. Specifically, each piezoelectric element 41 is constructed by laminating a first electrode and a second electrode that are opposed to each other, and a piezoelectric layer formed between the two electrodes. Each piezoelectric element 41 is an energy generating element that causes the ink in the pressure chamber C to be ejected from the nozzle N by changing the pressure of the ink in the pressure chamber C. That is, the vibration plate 35 is vibrated by deforming the piezoelectric element 41 by supplying a driving signal, and the pressure chamber C is expanded and contracted by the vibration of the vibration plate 35, so that the ink is ejected from the nozzle N. The pressure chamber C (Ca, Cb) is defined as a range in the independent flow channel P where the vibration plate 35 is vibrated by the deformation of the piezoelectric element 41.

[0162] The protective substrate 43 is a plate-shaped component provided on the surface Fe2 of the vibration plate 35, which protects the plurality of piezoelectric elements 41 and strengthens the mechanical strength of the vibration plate 35. The plurality of piezoelectric elements 41 are accommodated between the protective substrate 43 and the vibration plate 35. In addition, a wiring substrate 44 is mounted on the surface Fe2 of the vibration plate 35. The wiring substrate 44 is a mounting component for electrically connecting the control unit 21 and the liquid ejection head 24. For example, a flexible wiring substrate 44 such as an FPC (Flexible Printed Circuit) or an FFC (Flexible Flat Cable) is preferably used. A drive circuit 45 for supplying a drive signal to each piezoelectric element 41 is mounted on the wiring substrate 44.

[0163] Next, a detailed structure of the independent flow channel P will be described. The shape of the independent flow channel Pa and the shape of the independent flow channel Pb are in a rotationally symmetric relationship around a symmetry axis parallel to the Z axis when viewed in a plan view.

[0164] like Fig.25 As shown, the independent flow channel Pa has a supply flow channel Ra1, a pressure chamber Ca1, a first communication flow channel Na1, a nozzle flow channel Nfa, a second communication flow channel Na2, a lateral communication flow channel Cq1 and a discharge flow channel Ra2. The independent flow channel Pa is a flow channel in which these elements are integrally constituted, and is a flow channel in which the aforementioned elements are connected in the aforementioned order.

[0165] The supply flow channel Ra1 is a space formed on the connecting plate 33. Specifically, Fig.25 As shown, the supply flow channel Ra1 extends along the Z axis from the space O12 constituting the first common liquid chamber R1 to the surface Fc2 of the connecting plate 33. The end of the supply flow channel Ra1 connected to the space O12 is the end E1 of the independent flow channel Pa. The supply flow channel Ra1 is a flow channel that is connected to the pressure chamber Ca1 and guides the ink supplied from the first common liquid chamber R1 to the pressure chamber Ca1. The supply flow channel Ra1 is an example of a "first independent supply flow channel".

[0166] like Fig.25 As shown, the first communication flow channel Na1 is a space that penetrates the communication plate 33. The first communication flow channel Na1 is a flow channel along the Z axis. The first communication flow channel Na1 extends in the Z1 direction and is connected to the pressure chamber Ca1 and the nozzle flow channel Nfa. The first communication flow channel Na1 is a flow channel that guides the ink pressed out from the pressure chamber Ca1 to the nozzle flow channel Nfa.

[0167] The nozzle flow channel Nfa is a flow channel provided on the connecting plate 33 and extending in the X-axis direction. Fig.25As shown, the nozzle flow channel Nfa is divided into a first portion Pa1 and a second portion Pa2. The first portion Pa1 is a flow channel located between the first communication flow channel Na1 and the second portion Pa2 in the X-axis direction and extending in the X-axis direction. The second portion Pa2 is a flow channel located between the first portion Pa1 and the second communication flow channel Na2 in the X-axis direction and extending in the X-axis direction. The nozzle Na is provided on the first portion Pa1.

[0168] Here, the width h1 of the first portion Pa1 in the Z-axis direction is smaller than the width h2 of the second portion Pa2 in the Z-axis direction. Fig.25 As shown, the width W1 of the first portion Pa1 in the X1 direction is greater than the width W3 of the second portion Pa2 in the X1 direction.

[0169] The second communication flow channel Na2 is a space formed on the communication plate 33. The second communication flow channel Na2 is a flow channel along the Z axis. The second communication flow channel Na2 extends in the Z1 direction and communicates with the transverse communication flow channel Cq1 and the nozzle flow channel Nfa. The second communication flow channel Na2 is a flow channel that guides the ink supplied from the second portion Pa2 to the transverse communication flow channel Cq1.

[0170] The transverse communication channel Cq1 is a space formed on the communication plate 33. The transverse communication channel Cq1 is a long and narrow channel along the X axis. The transverse communication channel Cq1 extends in the X1 direction and is connected to the second communication channel Na2 and the discharge channel Ra2. The transverse communication channel Cq1 is a channel that guides the ink led out from the second communication channel Na2 to the discharge channel Ra2.

[0171] The discharge flow channel Ra2 is a space formed on the connecting plate 33. The end of the discharge flow channel Ra2 connected to the space O22 is the end E2 of the independent flow channel Pa. The discharge flow channel Ra2 is a flow channel that is connected to the transverse connecting flow channel Cq1 and guides the ink led out from the transverse connecting flow channel Cq1 to the second common liquid chamber R2. The discharge flow channel Ra2 is an example of a "first independent discharge flow channel".

[0172] like Fig.26 As shown, the independent flow channel Pb has a supply flow channel Rb1, a lateral communication flow channel Cq2, a third communication flow channel Nb1, a nozzle flow channel Nfb, a fourth communication flow channel Nb2, a pressure chamber Cb1 and a discharge flow channel Rb2. The independent flow channel Pb is a flow channel in which these elements are integrally constituted, and is a flow channel in which the aforementioned elements are connected in the aforementioned order.

[0173] The supply flow channel Rb1 is a space formed on the connecting plate 33. The end of the supply flow channel Rb1 connected to the space O12 is the end E1 of the independent flow channel Pb. The supply flow channel Rb1 is a flow channel that communicates with the transverse connecting flow channel Cq2 and guides the ink supplied from the first common liquid chamber R1 to the transverse connecting flow channel Cq2. The supply flow channel Rb1 is an example of a "second independent supply flow channel".

[0174] The transverse communication flow channel Cq2 is a space provided on the communication plate 33. The transverse communication flow channel Cq2 is a long and narrow flow channel along the X axis. The transverse communication flow channel Cq2 extends in the X1 direction and communicates with the supply flow channel Rb1 and the third communication flow channel Nb1. The transverse communication flow channel Cq1 is a flow channel that guides the ink led out from the supply flow channel Rb1 to the third communication flow channel Nb1.

[0175] like Fig.26 As shown, the third communication flow channel Nb1 is a space provided on the communication plate 33. The third communication flow channel Nb1 is a flow channel along the Z axis. The third communication flow channel Nb1 extends in the Z1 direction and is connected to the transverse communication flow channel Cq2 and the nozzle flow channel Nfb. The third communication flow channel Nb1 is a flow channel that guides the ink derived from the transverse communication flow channel Cq2 to the nozzle flow channel Nfb.

[0176] The nozzle flow channel Nfb is a flow channel provided on the connecting plate 33 and extending in the X-axis direction. Fig.26 As shown, the nozzle flow channel Nfb is divided into a third part Pb1 and a fourth part Pb2. The third part Pb1 is a flow channel located between the third communication flow channel Nb1 and the fourth part Pb2 in the X-axis direction and extending in the X-axis direction. The fourth part Pb2 is a flow channel located between the third part Pb1 and the fourth communication flow channel Nb2 in the X-axis direction and extending in the X-axis direction. The nozzle Nb is set on the fourth part Pb2.

[0177] Here, the width h2 of the third portion Pb1 in the Z-axis direction is greater than the width h1 of the fourth portion Pb2 in the Z-axis direction. Fig.26 As shown, the width W5 of the third portion Pb1 in the X1 direction is smaller than the width W7 of the fourth portion Pb2 in the X1 direction.

[0178] The fourth communication flow channel Nb2 is a space penetrating the communication plate 33. The fourth communication flow channel Nb2 is a flow channel along the Z axis. The fourth communication flow channel Nb2 extends in the Z1 direction and communicates with the pressure chamber Cb1 and the nozzle flow channel Nfb. The fourth communication flow channel Nb2 is a flow channel that guides the ink supplied from the nozzle flow channel Nfb to the pressure chamber Cb1.

[0179] The discharge flow channel Rb2 is a space formed on the connecting plate 33. Specifically, Fig.26 As shown, the discharge flow channel Rb2 extends along the Z axis from the space O22 constituting the second common liquid chamber R2 to the surface Fc2 of the connecting plate 33. The end of the discharge flow channel Rb2 connected to the space O22 is the end E2 of the independent flow channel Pb. The discharge flow channel Rb2 is a flow channel that communicates with the pressure chamber Cb1 and guides the ink pressed out of the pressure chamber Cb1 to the second common liquid chamber R2. The discharge flow channel Rb2 is an example of a "second independent discharge flow channel".

[0180] exist Fig.25 , Fig.26 In the embodiment, regarding the independent flow channel Pa and the independent flow channel Pb adjacent to each other, there is no flow channel at the adjacent positions in the Y-axis direction in the pressure chamber Ca1 of the independent flow channel Pa and the lateral connecting flow channel Cq1. In addition, there is no flow channel at the adjacent positions in the Y-axis direction in the pressure chamber Cb1 of the independent flow channel Pb and the lateral connecting flow channel Cq2. Therefore, compared with the sixth embodiment, even if the spacing θ is reduced, structural crosstalk is difficult to occur. Therefore, the spacing θ can be reduced to improve the nozzle resolution in the Z-axis direction, so that high-quality images can be recorded. In addition, although the first connecting flow channel Na1 and the third connecting flow channel Nb1 are located at the same position in the X-axis direction in the present embodiment, they can also be set at different positions in the X-axis direction. The same is true for the second connecting flow channel Na2 and the fourth connecting flow channel Nb2. By making their positions different, it is possible to make it difficult for structural crosstalk between the first connecting flow channel Na1 and the third connecting flow channel Nb1 and between the second connecting flow channel Na2 and the fourth connecting flow channel Nb2 to occur, so the spacing θ can be further reduced.

[0181] Here, as described above, in the present embodiment, the nozzle flow channel Nfa is provided with a first portion Pa1 having a smaller width in the Z-axis direction and a second portion Pa2 having a larger width. In addition, the nozzle flow channel Nfb is also provided with a third portion Pb1 having a larger width in the Z-axis direction and a fourth portion Pb2 having a smaller width. Moreover, the nozzle flow channel Nfa and the nozzle flow channel Nfb are provided in such a manner that the first portion Pa1 and the third portion Pb1 do not overlap at least partially in the X-axis direction. Thus, in the same manner as in the above-mentioned embodiments, the occurrence of structural crosstalk can be reduced while suppressing an increase in flow channel resistance.

[0182] 8. Other Implementation Methods

[0183] The liquid ejection head 24 is not limited to the structures illustrated in the first to seventh embodiments. The liquid ejection head 24 may be a structure in which two or more structures arbitrarily selected from the structures illustrated in the first to seventh embodiments are combined within a range that does not contradict each other.

[0184] 9. Modifications

[0185] Although the embodiments of the present disclosure are described above, the present disclosure is not limited to the above embodiments, and various changes can be made. In the following, specific deformation modes that can be given to the above-mentioned modes are illustrated. The modes that can be arbitrarily selected from the following examples can also be appropriately combined within the scope of non-contradiction.

[0186] (1) Fig.28 Schematic diagram showing the flow path structure in the liquid ejection head 24 according to the modification when the liquid ejection head 24 is viewed from the Z-axis direction. Fig.29 for Fig.28 The cross-sectional view of line aa, Fig.30 for Fig.28 Cross-sectional view of line bb.

[0187] The liquid ejection head 24 is not limited to the structures shown in the above-mentioned embodiments, and for example, the first portion Pa1 of the nozzle flow channel Nfa is connected to the second communication flow channel Na2, and the second portion Pa2 is connected to the first communication flow channel Na1. Similarly, the third portion Pb1 of the nozzle flow channel Nfb is connected to the second communication flow channel Na2, and the fourth portion Pb2 is connected to the first communication flow channel Na1.

[0188] (2) The energy generating element that changes the pressure of the ink in the pressure chamber C is not limited to the piezoelectric element 41 exemplified in the above-mentioned embodiment. For example, a heating element that generates bubbles in the pressure chamber C by heating to change the pressure of the ink may be used as the energy generating element. In the structure in which the heating element is used as the energy generating element, the range in the independent flow channel P where bubbles are generated by heating by the heating element is defined as the pressure chamber C.

[0189] (3) Although the above embodiment illustrates a serial liquid ejection device 100 in which the transport body 231 carrying the liquid ejection head 24 moves back and forth, the present invention can also be applied to a line liquid ejection device in which a plurality of nozzles N are distributed across the entire width of the medium 11.

[0190] (4) Although the above-mentioned method describes the case where the width W1 of the first part Pa1 in the X1 direction is greater than the width W3 of the second part Pa2 in the X1 direction, the present invention is not limited to the above-mentioned case. As a modified example, the width W1 of the first part Pa1 in the X1 direction may be smaller than the width W3 of the second part Pa2 in the X1 direction. In addition, the width W7 of the fourth part Pb2 in the X1 direction may be smaller than the width W5 of the third part Pb1 in the X1 direction. In this case, W1=W7 and W3=W5 may also be satisfied. As in the above-mentioned method, if W1>W3 and W7>W5, there is no overlap between the first part Pa1 and the fourth part Pb2 in the X-axis direction, so the influence of structural crosstalk can be greatly reduced. In contrast, in this modification, when W1<W3 and W7<W5, since the first portion Pa1 and the fourth portion Pb2 partially overlap in the X-axis direction in the X-axis center area of ​​the nozzle flow channel Nfa and the nozzle flow channel Nfb, the influence of structural crosstalk may be generated compared with the above-mentioned method. However, the second portion Pa2 and the third portion Pb1 are provided, which is different from the method using Fig. 9 as well as Fig.10 In comparison with the described system, the influence of structural crosstalk can be reduced. In addition, in this modification, since the distance between the first portion Pa1 and the fourth portion Pb2 in the X-axis direction can be extended compared with the above-described embodiment, the flow path resistance can be reduced compared with the above-described embodiment.

[0191] 10. Supplement

[0192] The liquid ejection device 100 is not limited to the structure shown in the above-mentioned embodiment, for example, it can also be a general liquid ejection device that circulates ink other than the structure illustrated in the above-mentioned embodiments. In addition, the liquid ejection device 100 illustrated in the above-mentioned embodiments can be used in various devices such as fax machines or copiers in addition to devices dedicated to printing, and the use of the present invention is not particularly limited. Originally, the use of liquid ejection devices 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 wiring and electrodes of a wiring substrate. In addition, a liquid ejection device that ejects a solution of an organic substance related to a living body is used as a manufacturing device for manufacturing, for example, a biochip.

[0193] In addition, the effects described in this specification are merely illustrative or exemplary, and are not limiting. That is, the present invention can achieve other effects that are obvious to those skilled in the art based on the description of this specification in addition to or in place of the above-mentioned effects.

[0194] Although the preferred embodiments of the present invention are described in detail with reference to the accompanying drawings, the present invention is not limited to the relevant examples. Obviously, if a person has common knowledge in the technical field of the present invention, various variations or modifications can be thought of within the scope of the technical ideas recorded in the technical solution. Of course, it should be understood that the above content also belongs to the technical scope of the present invention.

[0195] 11. Notes

[0196] According to the above-exemplified embodiment, for example, the following configurations can be understood.

[0197] In addition, in the present application, when element A and element B are viewed along a specific direction, "overlapping" means that when viewed along the direction, at least a portion of element A and at least a portion of element B overlap each other. It is not necessary for all of element A and all of element B to overlap each other, as long as at least a portion of element A overlaps at least a portion of element B, it can be interpreted as "element A and element B overlap".

[0198] A liquid ejection head according to one embodiment of the present disclosure (method 1) includes: a first pressure chamber extending in a first direction and applying pressure to a liquid; a second pressure chamber extending in the first direction and applying pressure to a liquid; a first nozzle flow channel extending in the first direction and provided with a first nozzle for ejecting liquid; a first connecting flow channel extending in a second direction intersecting the first direction and communicating with the first pressure chamber and the first nozzle flow channel; a second connecting flow channel extending in the second direction and communicating with the second pressure chamber and the first nozzle flow channel, the first nozzle flow channel having a first portion and a second portion, the first portion including one end of the first nozzle flow channel, the second portion including the other end of the first nozzle flow channel, the width of the second portion in the second direction being greater than the width of the first portion in the second direction. According to this embodiment, it is possible to reduce structural crosstalk while suppressing an increase in the flow channel resistance of the first nozzle flow channel.

[0199] According to a specific example of the first embodiment (the second embodiment), it is further provided with: a third pressure chamber extending in the first direction and applying pressure to the liquid; a fourth pressure chamber extending in the first direction and applying pressure to the liquid; a second nozzle flow channel extending in the first direction and provided with a second nozzle for ejecting liquid; a third connecting flow channel extending in the second direction and communicating with the third pressure chamber and the second nozzle flow channel; a fourth connecting flow channel extending in the second direction and communicating with the fourth pressure chamber and the second nozzle flow channel, the second nozzle flow channel having a third portion and a fourth portion, the third portion including one end of the second nozzle flow channel, the fourth portion including the other end of the second nozzle flow channel, the width of the fourth portion in the second direction being smaller than the width of the third portion in the second direction. According to this embodiment, it is possible to reduce structural crosstalk while suppressing the increase in the flow channel resistance of the first nozzle flow channel and the second nozzle flow channel.

[0200] According to a specific example of the second aspect (a third aspect), the first nozzle and the second nozzle are located at the same position in the first direction.

[0201] According to a specific example of the third aspect (a fourth aspect), the first nozzle flow channel and the second nozzle flow channel are adjacent to each other in a third direction intersecting the first direction and the second direction.

[0202] According to a specific example of any one of the methods 2 to 4 (method 5), the first part and the third part at least partially overlap in the first direction, and the second part and the fourth part at least partially overlap in the first direction. According to this method, even if vibrations accompanying the flow of ink are generated in the third part, since the first part does not exist at a position overlapping with the third part in the third direction, the vibrations are difficult to be transmitted to the first part, thereby reducing the impact on the ejection of the first nozzle. In other words, structural crosstalk is difficult to occur. Similarly, since the fourth part Pb2 does not exist at a position overlapping with the second part Pa2 in the third direction, the vibrations from the second part Pa2 are difficult to be transmitted to the fourth part Pb2, thereby making structural crosstalk difficult to occur.

[0203] According to a specific example of the fifth aspect (the sixth aspect), the third portion entirely overlaps with the first portion in the first direction, and the second portion entirely overlaps with the fourth portion in the first direction.

[0204] According to a specific example (aspect seven) of any one of aspects two to six, a width of the fourth portion in the second direction is equal to a width of the first portion in the second direction.

[0205] According to a specific example (aspect eight) of any one of aspects two to seven, a width of the third portion in the second direction is equal to a width of the second portion in the second direction.

[0206] According to a specific example of any one of Methods 2 to 8 (Method 9), the width of the third part in the first direction is the same as the width of the second part in the first direction, and the width of the fourth part in the first direction is the same as the width of the first part in the first direction.

[0207] According to a specific example (method 10) of any one of methods 2 to 9, it also comprises: a first independent supply channel, which is connected to the first pressure chamber and supplies liquid to the first pressure chamber; a second independent supply channel, which is connected to the third pressure chamber and supplies liquid to the third pressure chamber; a common supply channel, which supplies liquid to the first independent supply channel and the second independent supply channel in a common manner; a first independent discharge channel, which is connected to the second pressure chamber and discharges liquid from the second pressure chamber; a second independent discharge channel, which is connected to the fourth pressure chamber and discharges liquid from the fourth pressure chamber; and a common discharge channel, which discharges liquid from the first independent discharge channel and the second independent discharge channel in a common manner.

[0208] According to a specific example of the tenth aspect (the eleventh aspect), the first portion is communicated with the first communicating flow channel, and the second portion is communicated with the second communicating flow channel.

[0209] According to a specific example of the tenth aspect (a twelfth aspect), the first portion is communicated with the second communication channel, and the second portion is communicated with the first communication channel.

[0210] According to a specific example (aspect thirteen) of any one of aspects 1 to twelfth, the width of the second portion in the second direction is larger than three times the width of the first portion in the second direction.

[0211] According to a specific example (aspect fourteen) of any one of aspects one to thirteen, a width of the second portion in a third direction intersecting the first direction and the second direction is smaller than a width of the first portion in the third direction.

[0212] According to a specific example (method fifteen) of any one of methods one to fourteen, when observing from the first nozzle flow channel, the side where the first pressure chamber and the second pressure chamber are located in the second direction is set as the first side, and the side where the first nozzle is located in the second direction is set as the second side, the flow channel wall surface on the second side of the first part and the flow channel wall surface on the second side of the second part are in the same position in the second direction, and the flow channel wall surface on the first side of the first part and the flow channel wall surface on the first side of the second part are in different positions in the second direction.

[0213] According to a specific example of any one of Methods 1 to 14 (Method 16), when the side where the first pressure chamber and the second pressure chamber are located in the second direction is set as the first side, and the side where the first nozzle is located in the second direction is set as the second side when observed from the first nozzle flow channel, the flow channel wall surface on the second side of the first part and the flow channel wall surface on the second side of the second part are at different positions in the second direction, and the flow channel wall surface on the first side of the first part and the flow channel wall surface on the first side of the second part are at the same position in the second direction.

[0214] According to a specific example (aspect seventeen) of any one of aspects one to sixteen, a width of the second portion in the first direction is smaller than a width of the first portion in the first direction.

[0215] According to a specific example (aspect 18) of any one of aspects 1 to 16, a width of the second portion in the first direction is greater than a width of the first portion in the first direction.

[0216] According to a specific example (aspect 19) of any one of aspects 1 to 18, the first nozzle is provided on the first portion.

[0217] According to a specific example (aspect 20) of any one of aspects 1 to 18, the first nozzle is provided on the second portion.

[0218] According to a specific example (method twenty-one) of any one of methods one to twenty, it also comprises: a first energy generating element, which generates energy for applying pressure to the liquid in the first pressure chamber by applying a driving voltage; and a second energy generating element, which generates energy for applying pressure to the liquid in the second pressure chamber by applying a driving voltage.

[0219] A liquid ejection device according to one aspect (aspect twenty-two) of the present disclosure includes: the liquid ejection head described in any one of aspects one to twenty-one; and a control unit that controls the ejection operation of the liquid ejection head.

[0220] Explanation of symbols

[0221] 41…piezoelectric element; 264…circulation flow channel; 265…supply flow channel; C, Ca, Cb, Ca1, Ca2, Cb1, Cb2…pressure chamber; Na1…first connecting flow channel; Na2…second connecting flow channel; Nb1…third connecting flow channel; Nb2…fourth connecting flow channel; Nfa, Nfb…nozzle flow channel; Pa1…first part; Pa2…second part; Pb1…third part; Pb2…fourth part; Ra1…first supply flow channel; Ra2…first discharge flow channel; Rb1…second supply flow channel; Rb2…second discharge flow channel.

Claims

1. A liquid ejection head, characterized in that: have: a first pressure chamber extending in a first direction and applying pressure to the liquid; a second pressure chamber extending in the first direction and applying pressure to the liquid; a third pressure chamber extending in the first direction and applying pressure to the liquid; a fourth pressure chamber extending in the first direction and applying pressure to the liquid; a first nozzle flow channel extending in the first direction and provided with a first nozzle for spraying liquid; a second nozzle flow channel extending in the first direction and provided with a second nozzle for spraying liquid; a first communication channel extending in a second direction intersecting the first direction and communicating with the first pressure chamber and the first nozzle channel; a second communication channel extending in the second direction and communicating with the second pressure chamber and the first nozzle channel; a third communication flow channel extending in the second direction and communicating with the third pressure chamber and the second nozzle flow channel; a fourth communication channel extending in the second direction and communicating with the fourth pressure chamber and the second nozzle channel, The first nozzle channel has a first portion and a second portion, the first portion includes one end of the first nozzle channel, and the second portion includes the other end of the first nozzle channel. The second nozzle flow channel has a third portion and a fourth portion, the third portion includes one end portion of the second nozzle flow channel, and the fourth portion includes the other end portion of the second nozzle flow channel. The width of the second portion in the second direction is greater than the width of the first portion in the second direction, The width of the fourth portion in the second direction is smaller than the width of the third portion in the second direction, The first portion and the third portion at least partially overlap in the first direction, The second portion and the fourth portion at least partially overlap in the first direction.

2. The liquid ejection head according to claim 1, wherein: The first nozzle and the second nozzle are located at the same position in the first direction.

3. The liquid ejection head according to claim 2, wherein: The first nozzle flow channel and the second nozzle flow channel are adjacent to each other in a third direction intersecting the first direction and the second direction.

4. The liquid ejection head according to claim 1, wherein: The third portion completely overlaps the first portion in the first direction, The second portion entirely overlaps the fourth portion in the first direction.

5. The liquid ejection head according to claim 1, wherein: A width of the fourth portion in the second direction is the same as a width of the first portion in the second direction.

6. The liquid ejection head according to claim 1, wherein: A width of the third portion in the second direction is the same as a width of the second portion in the second direction.

7. The liquid ejection head according to claim 1, wherein: The width of the third portion in the first direction is the same as the width of the second portion in the first direction, A width of the fourth portion in the first direction is the same as a width of the first portion in the first direction.

8. The liquid ejection head according to claim 1, wherein: Also available: a first independent supply channel, which is in communication with the first pressure chamber and supplies liquid to the first pressure chamber; a second independent supply channel, which is in communication with the third pressure chamber and supplies liquid to the third pressure chamber; a common supply flow channel that supplies liquid to the first independent supply flow channel and the second independent supply flow channel in a common manner; a first independent discharge flow channel, which is in communication with the second pressure chamber and discharges liquid from the second pressure chamber; a second independent discharge flow channel, which is in communication with the fourth pressure chamber and discharges liquid from the fourth pressure chamber; A common discharge flow channel discharges liquid from the first independent discharge flow channel and the second independent discharge flow channel in a common manner.

9. The liquid ejection head according to claim 8, wherein: The first portion is in communication with the first communication channel, The second portion is in communication with the second communication flow channel.

10. The liquid ejection head according to claim 8, wherein The first portion is in communication with the second communication channel, The second portion is in communication with the first communication channel.

11. The liquid ejection head according to claim 1, wherein A width of the second portion in the second direction is greater than three times a width of the first portion in the second direction.

12. The liquid ejection head according to claim 1, wherein A width of the second portion in a third direction intersecting the first direction and the second direction is smaller than a width of the first portion in the third direction.

13. The liquid ejection head according to claim 1, wherein: When the first nozzle flow channel is viewed from the first nozzle flow channel, the first side is defined as the first side, and the second side is defined as the second side. The flow channel wall surface on the second side of the first portion and the flow channel wall surface on the second side of the second portion are located at the same position in the second direction, The flow channel wall surface on the first side of the first portion and the flow channel wall surface on the first side of the second portion are located at different positions in the second direction.

14. The liquid ejection head according to claim 1, wherein When the first nozzle flow channel is viewed from the first nozzle flow channel, the first side is defined as the first side, and the second side is defined as the second side. The flow channel wall surface on the second side of the first portion and the flow channel wall surface on the second side of the second portion are located at different positions in the second direction, The flow channel wall surface on the first side of the first portion and the flow channel wall surface on the first side of the second portion are located at the same position in the second direction.

15. The liquid ejection head according to claim 1, wherein A width of the second portion in the first direction is smaller than a width of the first portion in the first direction.

16. The liquid ejection head according to claim 1, wherein A width of the second portion in the first direction is greater than a width of the first portion in the first direction.

17. The liquid ejection head according to claim 1, wherein The first nozzle is disposed on the first portion.

18. The liquid ejection head according to claim 1, wherein The first nozzle is disposed on the second portion.

19. The liquid ejection head according to claim 1, wherein: Also available: A first energy generating element that generates energy for applying pressure to the liquid in the first pressure chamber by applying a driving voltage thereto; The second energy generating element generates energy for applying pressure to the liquid in the second pressure chamber by applying a driving voltage.

20. A liquid ejection device, characterized in that: have: The liquid ejection head according to any one of claims 1 to 19; A control unit controls the ejection operation of the liquid ejection head.

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