JP7806553B2 - Liquid jet head and liquid jet apparatus - Google Patents

Description

This disclosure relates to a liquid ejection head and a liquid ejection device.

Patent Document 1 discloses a liquid ejection head in which four pressure chambers are provided on both sides of a nozzle, and the flow paths leading from each of the four pressure chambers to the nozzle merge near the nozzle.

Japanese Patent Application Laid-Open No. 2019-155768

However, with the above-mentioned conventional technology, the flow paths from the four pressure chambers to the nozzle were narrow, resulting in high flow path resistance and poor ejection efficiency.

A liquid jet head according to a first aspect of the present disclosure includes a nozzle plate in which a first nozzle for ejecting liquid is formed, first and second pressure chambers arranged side by side in a first direction, third and fourth pressure chambers arranged side by side in the first direction, a first communication flow path that is a flow path extending along the nozzle plate, the first communication flow path being connected to the first nozzle and communicating with the first to fourth pressure chambers, a first common liquid chamber communicating with the first and second pressure chambers, and a second common liquid chamber communicating with the third and fourth pressure chambers. The set of first and second pressure chambers and the set of third and fourth pressure chambers are arranged at different positions in a second direction orthogonal to the first direction. When a width in the first direction of the first communication flow path at a position overlapping with the first nozzle in a plan view looking toward the nozzle plate is defined as a first width, and a width in the first direction of the first pressure chamber is defined as a pressure chamber width, the first width is equal to or greater than the pressure chamber width.

A liquid jet head according to a second aspect of the present disclosure includes a nozzle plate in which nozzles for ejecting liquid are formed, N pressure chambers A arranged side by side in a first direction, where N is an integer of 3 or greater, N pressure chambers B arranged side by side in the first direction, wherein groups of the N pressure chambers A are arranged at different positions in a second direction orthogonal to the first direction, a communication flow path extending along the nozzle plate, the communication flow path being connected to the nozzle and communicating with the N pressure chambers A and the N pressure chambers B, a first common liquid chamber communicating with the N pressure chambers A, and a second common liquid chamber communicating with the N pressure chambers B. When a width in the first direction of the communication flow path at a position overlapping with the nozzle in a plan view looking toward the nozzle plate is defined as a first width, and a width in the first direction of the pressure chamber A is defined as a pressure chamber width, the first width is equal to or greater than the pressure chamber width.

A liquid ejection device according to a third aspect of the present disclosure includes the liquid ejection head and a liquid storage section that stores liquid to be supplied to the liquid ejection head.

FIG. 1 is an explanatory diagram illustrating a configuration of a liquid ejecting apparatus according to an embodiment. FIG. FIG. 3 is a cross-sectional view showing the III-III cross section of FIG. 2 . 4 is a diagram showing a part of the flow paths for three nozzles and the first and second common liquid chambers as viewed from the bottom of FIG. 3; FIG. FIG. 4 is a diagram showing a part of a flow path for one nozzle as seen from the bottom of FIG. 3 . FIG. 6 is an enlarged view of the flow path of FIG. 5 . FIG. 4 is an explanatory diagram showing the relationship between the pressure chamber width and the wall thickness. FIG. 4 is an explanatory diagram showing the relationship between the pressure chamber width and the wall thickness. FIG. 10 is a diagram showing the shape of a nozzle-specific flow path in the second embodiment. FIG. 11 is a diagram showing the shape of a nozzle-specific flow path in the third embodiment. FIG. 10 is a diagram showing the shape of a nozzle-specific flow path in the fourth embodiment. FIG. 13 is a diagram showing the shape of a nozzle-specific flow path in the fifth embodiment. FIG. 20 is a diagram showing the shape of a nozzle-specific flow path in the sixth embodiment. FIG. 23 is a diagram showing the shape of a nozzle-specific flow path in the seventh embodiment. FIG. 20 is a diagram showing the shape of a nozzle-specific flow path in the eighth embodiment.

A. First Embodiment FIG. 1 is an explanatory diagram showing the configuration of a liquid ejection device 400 according to an embodiment. The liquid ejection device 400 is an inkjet printing device that ejects ink, an example of a liquid, onto a medium PM. The composition of the ink is not particularly limited. For example, the ink may be an aqueous ink in which a colorant such as a dye or pigment is dissolved in an aqueous solvent, a solvent-based ink in which a colorant is dissolved in an organic solvent, or an ultraviolet-curable ink. The liquid ejection device 400 may also eject paint as a liquid instead of ink. The liquid ejection device 400 may be equipped with a liquid storage unit 420 that stores ink. The liquid ejection device 400 performs printing by ejecting the ink in the liquid storage unit 420 toward the medium PM. The liquid ejection device 400 includes a liquid ejection head 100, a movement mechanism 430, a transport mechanism 440, a control unit 450, and a circulation mechanism 60.

The liquid jet head 100 has multiple nozzles 200 as shown in FIG. 2, and jets liquid ink supplied from a liquid storage section 420 from the multiple nozzles 200. Specific examples of the liquid storage section 420 include a cartridge that can be attached to and detached from the liquid jet device 400, a bag-shaped ink pack made of flexible film, and a container such as an ink tank that can be refilled with ink. The ink jetted from the nozzles 200 lands on a medium PM, which is typically printing paper. Note that the medium M is not limited to printing paper and may be a printing target made of any material, such as a resin film or fabric.

The movement mechanism 430 includes a loop-shaped belt 432 and a carriage 434 fixed to the belt 432. The carriage 434 holds the liquid jet head 100. The movement mechanism 430 can move the liquid jet head 100 back and forth along the X direction by rotating the loop-shaped belt 432 in both directions.

The transport mechanism 440 transports the medium PM along the Y direction between movements of the liquid jet head 100 by the movement mechanism 430. The Y direction is a direction perpendicular to the X direction. In this embodiment, the X and Y directions are horizontal. The Z direction is a direction intersecting the X and Y directions. In this embodiment, the Z direction is vertically downward. The liquid jet head 100 ejects ink along the Z direction while being transported along the X direction. The Z direction is also referred to as the "ejection direction Z." In the following description, the tip side of the arrow indicating the X direction in the figure is referred to as the +X side, and the base end side is referred to as the -X side. The tip side of the arrow indicating the Y direction in the figure is referred to as the +Y side and the base end side is referred to as the -Y side. The tip side of the arrow indicating the Z direction in the figure is referred to as the +Z side and the base end side is referred to as the -Z side.

The control unit 450 controls the ink ejection operation from the liquid ejection head 100. The control unit 450 controls the transport mechanism 440, the movement mechanism 430, and the liquid ejection head 100 to form an image on the medium PM.

Figure 2 is a bottom view of the liquid jet head 100. The liquid jet head 100 has a plurality of nozzles 200. The plurality of nozzles 200 are formed to penetrate a nozzle plate 240 arranged parallel to the XY plane. The plurality of nozzles 200 are arranged linearly along the Y direction to form a nozzle row NL. The nozzle plate 240 is manufactured, for example, by processing a silicon single crystal substrate using semiconductor processing technology. A silicon single crystal substrate with a (100) plane as its main surface is preferably used as the silicon single crystal substrate. The nozzle plate 240 may also be formed from a material such as stainless steel (SUS) or titanium.

Figure 3 is a cross-sectional view taken along the line III-III in Figure 2. Figure 4 is a diagram showing the flow paths for three nozzles, the first common liquid chamber 110, and a portion of the second common liquid chamber 120, as viewed from the bottom of Figure 3. Figure 5 is a diagram showing the flow paths for one nozzle, and a portion of the common liquid chambers 110 and 120, as viewed from the bottom of Figure 3. Figure 6 is an enlarged view of the flow paths in Figure 5. Note that Figure 4 only shows three nozzle-specific flow paths 130, the first common liquid chamber 110, and the second common liquid chamber 120. Note that for ease of illustration, in Figure 5, the communicating flow path 350 is drawn with a solid line, the pressure chamber 330 with a dotted line, the drive element 300 with a dashed line, and the common liquid chambers 110 and 120 with a dashed line. In Figure 6, the connecting flow paths 321-324 and the drive elements 301-304 are omitted from the illustration. Also, Figure 4 illustrates three nozzles 200, including nozzles 200a and 200b. When nozzle 200a, which is any one of the multiple nozzles 200, is defined as the "first nozzle," nozzle 200b is an example of the "second nozzle." The nozzle 200 illustrated in Figures 3, 5, and 5 is nozzle 200a.

In Figure 3 and subsequent figures, the first direction Dr1, the second direction Dr2, and the third direction Dr3 are also shown. The first direction Dr1 is the direction in which the pressure chambers 331, 332 are aligned, and the pressure chambers 333, 334 are aligned. The second direction Dr2 is a direction perpendicular to the first direction Dr1. The first direction Dr1 and the second direction Dr2 are parallel to the surface of the nozzle plate 240. The third direction Dr3 is the thickness direction of the nozzle plate 240. The thickness direction of the nozzle plate 240 refers to the direction along the shortest of the three sides of the nozzle plate 240. In this embodiment, the first direction Dr1 is parallel to the Y direction, the second direction Dr2 is parallel to the X direction, and the third direction Dr3 is parallel to the Z direction. However, the three directions Dr1 to Dr3 may be set in directions different from this example.

As shown in FIG. 4, the spacing Pt1 between adjacent nozzles 200, i.e., the distance between the centers of the nozzles 200 in the Y direction, is constant. Furthermore, the spacing Pt2 between adjacent pressure chambers 330_L1 among the multiple pressure chambers 330_L1 that make up row L1, i.e., the distance between the centers of the pressure chambers 330_L1 in the Y direction, is constant. A similar relationship applies to row L2. Furthermore, the spacing Pt2 in row L1 and the spacing Pt2 in row L2 are the same, and spacing Pt2 is half of spacing Pt1. Furthermore, spacing Pt2 between pressure chambers 330 is the same as the spacing between communication holes 340, and is also the same as the spacing between the centers of the nozzles 200 in the Y direction.

As shown in FIG. 3, the liquid jet head 100 has a first common liquid chamber 110 to which ink is supplied, a second common liquid chamber 120 to which ink is discharged, and nozzle-specific flow paths 130 that connect the first common liquid chamber 110 and the second common liquid chamber 120. The first common liquid chamber 110 and the second common liquid chamber 120 are provided in common to multiple nozzles 200, and the nozzle-specific flow paths 130 are provided individually for each nozzle 200. Each of the common liquid chambers 110, 120 extends in the Y direction, which is the direction along the nozzle row NL. In other words, the longitudinal direction of the common liquid chambers 110, 120 is parallel to the direction in which the multiple nozzles 200 are arranged.

The liquid jet head 100 has a row L1 of multiple pressure chambers 330 that communicate with the first common liquid chamber 110, and a row L2 of multiple pressure chambers 330 that communicate with the second common liquid chamber 120. Row L1 is composed of multiple pressure chambers 330 lined up in the Y direction, and row L2 is composed of multiple pressure chambers 330 lined up in the Y direction. Row L1 is arranged on the -X side of the nozzle row NL, and row L2 is arranged on the +X side of the nozzle row NL. Hereinafter, the multiple pressure chambers 330 that make up row L1 will be referred to as pressure chambers 330_L1, and the multiple pressure chambers 330 that make up row L2 will be referred to as pressure chambers 330_L2. Regarding the driving elements 300, connection channels 320, and communication holes 340 described in detail below, the driving elements 300 corresponding to row L1 will be referred to as driving elements 300_L1, the driving elements 300 corresponding to row L2 will be referred to as driving elements 300_L2, the connection channels 320 corresponding to row L1 will be referred to as connection channels 320_L1, the connection channels 320 corresponding to row L2 will be referred to as connection channels 320_L2, the communication holes 340 corresponding to row L1 will be referred to as communication holes 340_L1, and the communication holes 340 corresponding to row L2 will be referred to as communication holes 340_L2.

In this embodiment, the nozzle-specific flow path 130 corresponding to one nozzle 200 includes two pressure chambers 330_L1 in row L1, two pressure chambers 330_L2 in row L2, two connecting flow paths 320_L1 corresponding to each of the two pressure chambers 330_L1, two connecting flow paths 320_L2 corresponding to each of the two pressure chambers 330_L2, two communication holes 340_L1 corresponding to each of the two pressure chambers 330_L1, two communication holes 340_L2 corresponding to each of the two pressure chambers 330_L2, and a communication flow path 350. Here, the two pressure chambers 330_L1 in this row L1 are referred to as pressure chambers 331 and 332, the two pressure chambers 330_L2 in this row L2 are referred to as pressure chambers 333 and 334, the two connection flow paths 320_L1 are referred to as connection flow paths 321 and 322, the two connection flow paths 320_L2 are referred to as connection flow paths 323 and 324, the two communication holes 340_L1 are referred to as communication holes 341 and 342, and the two communication holes 340_L2 are referred to as communication holes 343 and 344. Furthermore, the four drive elements 300 corresponding to the pressure chambers 331 to 334, respectively, are referred to as drive elements 301 to 304.

Each of the common liquid chambers 110, 120 can be considered to extend in the Y direction or the direction in which adjacent pressure chambers 331, 332 are aligned, in other words, the extension direction of the row L1 of the pressure chambers 330. In this embodiment, the direction in which adjacent pressure chambers 331, 332 are aligned is an example of the "first direction." Furthermore, the multiple nozzle-specific flow paths 130 are aligned in the Y direction along the nozzle row NL.

The lower portions of the common liquid chambers 110, 120 and the multiple nozzle-specific flow paths 130 are primarily formed by the communication plate 140. The communication plate 140 may be constructed by stacking multiple plate-shaped members. The housing 160 and pressure chamber substrate 250 are mounted on the upper surface of the communication plate 140, i.e., the surface facing the -Z side of the communication plate 140. The pressure chamber substrate 250 is located inside the housing 160 in a plan view looking in the Z direction. The vibration plate 310 is located on the upper surface of the pressure chamber substrate 250, i.e., the surface facing the -Z side of the pressure chamber substrate 250. The pressure chamber substrate 250 has multiple pressure chambers 330. Each pressure chamber 330 is a space defined by the communication plate 140, the vibration plate 310, and the pressure chamber substrate 250. The pressure chamber substrate 250 is manufactured, for example, by processing a silicon single crystal substrate using semiconductor processing technology. As the silicon single crystal substrate, for example, a (110) substrate, i.e., a silicon single crystal substrate whose main surface is a (110) plane, is preferably used.

The diaphragm 310 is a plate-like member capable of elastically vibrating. The diaphragm 310 is a laminate including, for example, a first layer made of silicon oxide (SiO ₂ ) and a second layer made of zirconium oxide (ZrO ₂ ). Another layer, such as a metal oxide, may be interposed between the first and second layers. Part or all of the diaphragm 310 may be integrally formed with the pressure chamber substrate 250 using the same material. For example, the diaphragm 310 and the pressure chamber substrate 250 can be integrally formed by selectively removing a portion of a plate-like member of a predetermined thickness in the thickness direction in a region corresponding to the pressure chamber 330 by etching or the like. Alternatively, the diaphragm 310 may be formed from a layer of a single material.

A nozzle plate 240 is installed on the underside of the communication plate 140, i.e., the surface of the communication plate 140 facing the +Z side, and the lower ends of the first common liquid chamber 110 and the second common liquid chamber 120, i.e., the +Z side ends of the first common liquid chamber 110 and the second common liquid chamber 120, are sealed with a flexible sealing film 150 made of a resin film, thin metal film, or the like.

A wiring board 59 is bonded to the surface of the vibration plate 310 facing the -Z side. The wiring board 59 is a mounting component on which multiple wires are formed for electrically connecting the control unit 450 and the liquid jet head 100. The wiring board 59 is a flexible wiring board such as an FPC (Flexible Printed Circuit) or an FFC (Flexible Flat Cable). A drive circuit 70 for driving the drive elements 300 is mounted on the wiring board 59. The drive circuit 70 supplies drive signals to each drive element 300.

A plurality of drive elements 300 are provided on the upper surface of the vibration plate 310, i.e., the surface facing the -Z side of the vibration plate 310, corresponding to each pressure chamber 330. These drive elements 300 are, for example, piezoelectric elements. A piezoelectric element is, for example, composed of a piezoelectric layer and two electrodes arranged to sandwich the piezoelectric layer. For example, when the drive elements 301 to 304, which are piezoelectric elements, vibrate, the vibrations are transmitted to the pressure chambers 331 to 334, respectively, generating pressure waves in the pressure chambers 331 to 334. Ink is ejected from the nozzles 200 by the pressure generated by the drive elements 301 to 304. Note that instead of piezoelectric elements, heat-generating elements that heat the ink in the pressure chambers 330 may be used as drive elements.

A circulation mechanism 60 is connected to the common liquid chambers 110 and 120. The circulation mechanism 60 supplies ink to the first common liquid chamber 110 and recovers ink discharged from the second common liquid chamber 120 for resupply to the first common liquid chamber 110. The circulation mechanism 60 has a first supply pump 61, a second supply pump 62, a storage container 63, a recovery flow path 64, and a supply flow path 65.

The first supply pump 61 is a pump that supplies ink stored in the liquid storage section 420 to the storage container 63. The storage container 63 is a sub-tank that temporarily stores ink supplied from the liquid storage section 420. The recovery flow path 64 is interposed between the second common liquid chamber 120 and the storage container 63 and is a flow path for recovering ink from the second common liquid chamber 120 to the storage container 63. The ink stored in the liquid storage section 420 is supplied to the storage container 63 from the first supply pump 61. Furthermore, ink that is supplied from the first common liquid chamber 110 to each nozzle-specific flow path 130 but is not ejected from the nozzles 200 and is discharged from each nozzle-specific flow path 130 to the second common liquid chamber 120 is supplied to the storage container 63 via the recovery flow path 64. The second supply pump 62 is a pump that pumps out ink stored in the storage container 63. The supply flow path 65 is located between the first common liquid chamber 110 and the storage container 63, and is a flow path for supplying ink from the storage container 63 to the first common liquid chamber 110.

An opening 161 at the upper end of the first common liquid chamber 110, i.e., the end on the -Z side of the first common liquid chamber 110, is connected to a supply flow path 65 that is external to the liquid jet head 100. In other words, the opening 161 in this embodiment functions as an inlet for introducing liquid from the circulation mechanism 60. An opening 162 at the upper end of the second common liquid chamber 120, i.e., the end on the -Z side of the second common liquid chamber 120, is connected to a recovery flow path 64 of the circulation mechanism 60 that is external to the liquid jet head 100. In other words, the opening 162 in this embodiment functions as an outlet for discharging liquid from the circulation mechanism 60.

The nozzle-specific flow path 130 has the following flow paths and spaces. In the following description, the term "connected" is used to mean directly connected. The term "communicating" is used in a broader sense to include not only direct connection but also indirect connection.
<Connection flow paths 321 to 324>
The connection flow path 321 connects the first common liquid chamber 110 and the pressure chamber 331 .
The connection flow path 322 connects the first common liquid chamber 110 and the pressure chamber 332 .
The connection flow path 323 connects the second common liquid chamber 120 and the pressure chamber 333 .
The connection flow path 324 connects the second common liquid chamber 120 and the pressure chamber 334 .
The connection flow paths 321 to 324 are all flow paths that extend in the Z direction and penetrate the communication plate 140. For convenience of illustration, the connection flow paths 321 to 324 are hatched in Figures 5 and 6. The intersection of the connection flow path 320 and the pressure chamber 330 can be considered to be part of the pressure chamber 330.

<Pressure Chambers 331 to 334>
The pressure chambers 331 to 334 are spaces that are subjected to pressure changes by the drive elements 301 to 304, respectively. The pressure chambers 331 and 332 are arranged side by side in a first direction Dr1, and the pressure chambers 333 and 334 are also arranged side by side in the first direction Dr1. In this embodiment, the first direction Dr1 is parallel to the Y direction. The set of the pressure chambers 331 and 332 and the set of the pressure chambers 333 and 334 are arranged at different positions in a second direction Dr2 that is perpendicular to the first direction Dr1. In this embodiment, the second direction Dr2 is parallel to the X direction. Pressure waves generated in the pressure chambers 331 to 334 reach the nozzles 200 and eject ink from the nozzles 200. It is preferable that the pressure chambers 331 to 334 have the same shape. In this embodiment, the multiple pressure chambers 331 to 334 are arranged in a staggered pattern. Each pressure chamber 330 extends in the second direction Dr2. Here, the pressure chamber 331a communicating with the nozzle 200a is an example of a "first pressure chamber," the pressure chamber 332a communicating with the nozzle 200a is an example of a "second pressure chamber," the pressure chamber 333a communicating with the nozzle 200a is an example of a "third pressure chamber," and the pressure chamber 334a communicating with the nozzle 200a is an example of a "fourth pressure chamber."

<Communication holes 341 to 344>
The communicating holes 341 to 344 each extend in the Z direction and are flow paths connecting the communicating flow path 350 to the pressure chambers 331 to 334, respectively. That is, each pressure chamber 330 is connected at one end to the connecting flow path 320 and at the other end to the communicating hole 340. Note that in FIGS. 5 and 6, the communicating holes 341 to 344 are hatched for ease of illustration. Also, in FIG. 6, the connecting flow paths 321 to 324 and the driving elements 301 to 304 are omitted from illustration. The communicating holes 341 and 342 are arranged side by side in the first direction Dr1, and the communicating holes 343 and 344 are also arranged side by side in the first direction Dr1. The communicating holes 341 to 344 are flow paths extending in the same direction as the connecting flow paths 321 to 324 and penetrate the communicating plate 140. It is preferable that the communication holes 341 to 344 have the same shape. The portion where the communication hole 340 and the pressure chamber 330 intersect can be considered to be part of the pressure chamber 330.

<Communicating flow path 350>
As shown in FIG. 3 , the communication flow path 350 is a flow path connected to the nozzle 200 and communicating the nozzle 200 with the pressure chambers 331 to 334. The communication flow path 350 extends along the nozzle surface of the nozzle plate 240 on which the plurality of nozzles 200 are formed, and the nozzle 200 is provided midway along the communication flow path 350. Specifically, the communication flow path 350 extends along the X direction and is defined by the communication plate 140 and the surface of the nozzle plate 240 facing the -Z side. In other words, the communication flow path 350 is a flow path whose longitudinal direction is the second direction Dr2. The intersections between the communication holes 341 to 344 and the communication flow path 350 can be considered to be part of the communication flow path 350. Here, the communication flow path 350a connected to the nozzle 200a is an example of a "first communication flow path."

For example, a pseudoplastic liquid can be used as the ink. More specifically, the ink preferably has a viscosity of 0.01 Pa·s or more and 0.2 Pa·s or less at a shear rate of 1000 s ⁻¹ at 25°C, and a viscosity of 0.5 Pa·s or more and 50 Pa·s or less at a shear rate of 0.01 ^{s −1} . In this embodiment, the use of four pressure chambers 331-334 reduces the cross-sectional area of each flow channel, increasing the flow rate and reducing the ink viscosity, making it possible to use pseudoplastic liquid ink. However, because it is desirable to efficiently utilize the energy of the drive elements 301-304 from the pressure chambers 331-334 to the nozzle 200, excessively large flow channel resistance is not desirable. Therefore, in this embodiment, the flow channel resistance is reduced by increasing the width W _R1 of the communication flow channel 350 shown in FIG. 6.

In this embodiment, four pressure chambers 331-334 are provided for one nozzle 200, but five or more pressure chambers may be provided. In either case, a drive element is provided to correspond to each individual pressure chamber.

The nozzle-specific flow paths 130 in this embodiment can be considered to include four individual flow paths corresponding to the four drive elements 301-304, as well as a flow path common to the four drive elements 301-304. An "individual flow path" is a flow path that includes at least a pressure chamber 330, with one individual flow path corresponding to one drive element 300. In this embodiment, the first individual flow path can be considered to include a connection flow path 321, a pressure chamber 331, and a communication hole 341. The second to fourth individual flow paths can be understood in a similar manner. Furthermore, the flow path common to the four drive elements 301-304, in other words, the flow path common to the pressure chambers 331-334, corresponds to the communication flow path 350 connected to the four individual flow paths mentioned above. Furthermore, the multiple nozzle-specific flow paths 130 in this embodiment have approximately the same structure.

The liquid jet head 100 of the first embodiment has the following various features, mainly related to the flow path resistance.
<Feature D1>
As shown in Figure 6, in a plan view looking toward the nozzle plate 240, when the width in the first direction Dr1 of the communicating flow path 350 at the position overlapping with the nozzle 200 is defined as a first width W _R1 and the width in the first direction Dr1 of the pressure chamber 331 is defined as a pressure chamber width W _C1 , W _C1 ≦W _R1 is satisfied.
According to the feature D1, the first width W _R1 of the communication flow passage 350 is wide, so that a decrease in the injection efficiency can be suppressed.

The first width W _R1 of the communicating flow path 350 is preferably larger than the pressure chamber width W _C1 , and more preferably 1.5 times or more the pressure chamber width W _C1 . The first width W _R1 of the communicating flow path 350 is preferably equal to or less than twice the pressure chamber width W _C1 , and particularly preferably equal to twice the pressure chamber width W _C1 .

In this embodiment, the width W _C1 of the pressure chamber 331 is constant regardless of the position along the second direction Dr2. However, if the width W _C1 of the pressure chamber 331 varies along the second direction Dr2, it is preferable that the "pressure chamber width W _C1 " in the above-mentioned feature D1 be set to its maximum value. It is preferable that the widths W _C1 to W _C4 of the four pressure chambers 331 to 334 in the first direction Dr1 are equal to one another, and it is also preferable that the lengths L _C1 in the second direction Dr2 are equal to one another.

In the present disclosure, the first width W _R1 of the communicating flow path 350 refers to the distance between two wall surfaces that directly face each other in the first direction Dr1 among the wall surfaces that define the communicating flow path 350. "Two wall surfaces that directly face each other" means that no other wall surfaces or structures are present between them. The same applies to the widths and lengths of other flow paths, such as the pressure chamber 331.

<Feature D2>
As shown in FIG. 3 , when the height of the communication flow path 350 in the third direction Dr3 at a position overlapping with the nozzle 200 in a plan view is defined as a first height H _R1 , the first width W _R1 of the communication flow path 350 shown in FIG. 6 is equal to or greater than the first height H _R1 .
Here, the "first height H _R1 of the communicating flow path 350 at the position overlapping the nozzle 200" refers to the height of the communicating flow path 350 when it is assumed that the nozzle 200 does not have a recess. In other words, the first height H _R1 of the communicating flow path 350 is the distance between the upper surface of the nozzle plate 240 and the lower surface of the communicating plate 140. In other words, the first height H _R1 is the distance in the third direction Dr3 between the surface of the nozzle plate 240 that defines the communicating flow path 350 and the surface of the communicating plate 140 that faces the nozzle plate 240. This feature D2 makes it possible to ensure the rigidity of the communicating plate 140 while reducing the flow path resistance of the communicating flow path 350. Note that the first width W _R1 is preferably greater than the first height H _R1 .

<Feature D3>
As shown in FIG. 3 , when the thickness of the communicating plate 140 in the third direction Dr3 at a position overlapping the nozzle 200 in a plan view is defined as a first thickness _TR1 , the first thickness _TR1 is greater than the first height _HR1 of the communicating flow path 350.
This feature D3 reduces the flow resistance of the communicating flow passage while ensuring the rigidity of the communicating plate 140. The first thickness _TR1 is preferably at least two times the first height _HR1 , more preferably at least three times, and even more preferably at least four times.

<Feature D4>
When V1 (= 2 × W _S1 ) is twice the width W _S1 in the first direction Dr1 of the partition PW1 that separates the pressure chambers 331 and 332, and W S2 is the width in the first direction Dr1 of the partition PW2 that separates the two communicating flow paths 350 adjacent to each other in the first direction Dr1, the relationship V1 _{≦W S2 ≦} V1+W _C1 is satisfied.
The width W _S1 in the first direction Dr1 of the partition wall PW1 that separates the pressure chamber 331 and the pressure chamber 332 is shown in FIG. 6 . The width W _S2 in the first direction Dr1 of the partition wall PW2 that separates the two communicating flow paths 350 that are adjacent in the first direction Dr1 is shown in FIGS. 6 and 3 . Here, V1 is a "first value," and V1 + W _C1 is a "second value." Note that the "width W _S2 in the first direction Dr1 of the partition wall PW2 that separates the two communicating flow paths 350 that are adjacent in the first direction Dr1" refers to the width W _S2 of the partition wall PW2 when measured at a position where the nozzle 200 is disposed in the second direction Dr2.

7 and 8 are explanatory diagrams showing the relationship between pressure chamber width and wall thickness in relation to features D4 and D1 described above. Figures 7 and 8 schematically show two nozzles 200a and 200b adjacent to each other in the Y direction, a first communication flow path 350a and pressure chambers 331a to 334a associated with nozzle 200a, a second communication flow path 350b and pressure chambers 331b to 334b associated with nozzle 200b, partition wall Pw1, and partition wall Pw2. Here, pressure chamber 331b communicating with nozzle 200b is an example of a "fifth pressure chamber," pressure chamber 332b communicating with nozzle 200b is an example of a "sixth pressure chamber," pressure chamber 333b communicating with nozzle 200b is an example of a "seventh pressure chamber," and pressure chamber 334b communicating with nozzle 200b is an example of an "eighth pressure chamber." The width W _S1 of the partition wall Pw1 that separates two pressure chambers 330 adjacent to each other in the first direction Dr1 is constant, and the pressure chamber width W _C1 of each pressure chamber 330 is also constant. In both of the cases of Figures 7 and 8, the flow paths are arranged so that (2 × W _C1 + 2 × W _S1 ) = (W _R1 + W _S2 ) holds.

The example of Fig. 7 corresponds to the case where W _R1 = 2 x W _C1 in the above-mentioned characteristic D1, and W _S2 = V1 = (2 x W _S1 ) holds in the above-mentioned characteristic D4. On the other hand, the example of Fig. 8 corresponds to the case where W _R1 = W _C1 in the above-mentioned characteristic D1, and W _S2 = (V1 + W _C1 ) = (2 x W _S1 + W _C1 ) holds in the above-mentioned characteristic D4. In this way, when sets of nozzles 200, pressure chambers 330, and communication channels 350 are densely arranged at regular intervals along the first direction Dr1, it is preferable to have the above-mentioned characteristic D4.

As described above, the second direction Dr2 is the longitudinal direction of the communication flow path 350. That is, the distance L _G in the second direction Dr2 between the two pressure chamber rows 330_L1 and 330_L2 shown in FIGS. 4 and 6 is set to be larger than the first width W _R1 in the first direction Dr1 of the communication flow path 350.

As described above, according to the first embodiment, the liquid jet head 100 has at least some of the above-described features D1 to D4, and the first width W _R1 of the communication flow path 350 is set wide, so that it is possible to suppress a decrease in jetting efficiency. However, some of the above-described features may be omitted.

It is also possible to reduce the resistance of the communicating flow path 350 by increasing its height H _R1 instead of increasing its width W _R1 . However, increasing the height H _R1 of the communicating flow path 350 may result in an undesirable structure in that the etching depth of the communicating plate 140 increases, reducing rigidity. On the other hand, in the first embodiment described above, there is no need to increase the height H _R1 of the communicating flow path 350, which has the advantage of not excessively reducing the rigidity of the communicating plate 140.

B. Other Embodiments FIG. 9 is a diagram showing the shape of the nozzle-specific flow path 130 in a second embodiment. The main difference from the first embodiment shown in FIG. 6 is the shape of the communication flow path 350; the other configurations are substantially the same as those of the first embodiment. In the second embodiment, the communication flow path 350 includes a first portion 351, a second portion 352, and a third portion 353. The first portion 351 of the communication flow path 350 is disposed at one end of the communication flow path 350 and is connected to the communication holes 341 and 342. The second portion 352 of the communication flow path 350 is disposed at the other end of the communication flow path 350 and is connected to the communication holes 343 and 344. The third portion 353 of the communication flow path 350 is connected between the first portion 351 and the second portion 352. The third portion 353 is connected to the first portion 351 and the second portion 352 by inclined surfaces SP1 to SP4. A first width W _R1 of the third portion 353 in the first direction Dr1 is smaller than the width W _R2 of the first portion 351 and the second portion 352 .

In addition to the features of the first embodiment described above, the second embodiment further has the following features.
<Feature D5>
The communicating flow path 350 includes a portion, in plan view, at a position between the pressure chamber 331 and the pressure chamber 332 and the nozzle 200, where the width of the communicating flow path 350 in the first direction Dr1 is a second width W _R2 that is larger than the first width W _R1 of the communicating flow path 350 at a position that overlaps with the nozzle 200. The portion having the second width W _R2 is part of the first portion 351, and extends a predetermined length in the second direction Dr2.

Similarly, the communicating flow path 350 includes a portion, in plan view, at a position between the pressure chamber 333 and the pressure chamber 334 and the nozzle 200, where the width of the communicating flow path 350 in the first direction Dr1 is a second width W _R2 that is larger than the first width W _R1 of the communicating flow path 350 at a position that overlaps with the nozzle 200. The portion having the second width W _R2 is part of the second portion 352, and extends a predetermined length in the second direction Dr2. It is preferable that the second width W _R2 in the first direction Dr1 of the first portion 351 and the second width W _R2 in the first direction Dr1 of the second portion 352 are equal to each other.

Feature D5 allows the flow rate to be increased near the nozzle 200. When using a pseudoplastic liquid, the advantage of feature D5 is particularly pronounced, since increasing the flow rate can reduce the viscosity of the liquid.

It should be noted that, under the characteristic D5, it is preferable to satisfy the following formula (1), and it is more preferable to satisfy the following formula (2).
0.1×W _C1 ≦(W _R2 −W _R1 )…(1)
0.2×W _C1 ≦(W _R2 −W _R1 )…(2)
That is, the value (W _R2 −W _R1 ) obtained by subtracting the first width W _R1 from the second width W _R2 is preferably 0.1 times or more, and more preferably 0.2 times or more, the pressure chamber width W _C1 .

It is also preferable that both the following formulas (3a) and (3b) be satisfied.
W _R1 <(W _C1 ×1.5) …(3a)
(W _C1 ×1.5)<W _R2 ≦(W _C1 ×2) …(3b)

The first width W _R1 is preferably 1.5 times or less the pressure chamber width W _C1 , more preferably 1.4 times or less, more preferably 1.3 times or less, more preferably 1.2 times or less, and more preferably 1.1 times or less. It is particularly preferable that the first width W _R1 be equal to the pressure chamber width W _C1 . The second width W _R2 is preferably 1.5 times or more the pressure chamber width W _C1 , more preferably 1.6 times or more, more preferably 1.7 times or more, more preferably 1.8 times or more, and more preferably 1.9 times or more. It is particularly preferable that the second width W _R2 be equal to twice the pressure chamber width W _C1 .

The second embodiment preferably further has the following features.
<Feature D6>
The first length L _R1 in the second direction _Dr2 of the portion of the communicating flow path 350 having the first width W R1 is 4% to 30% of the total length L _R of the communicating flow path 350 in the second direction Dr2.
According to this feature D6, it is possible to reduce the viscosity of the pseudoplastic liquid in the vicinity of the nozzle 200 while suppressing a decrease in the ejection efficiency by reducing the flow path resistance up to just before the nozzle.

10 is a diagram showing the shape of the nozzle-specific flow path 130 in the third embodiment. The main difference from the first embodiment shown in FIG. 6 is the shape of the communication flow path 350, and the other configurations are substantially the same as those of the first embodiment. The third embodiment also differs from the second embodiment in that the width W _R1 of the third portion 353 in the first direction Dr1 is larger than the width W _R3 of a portion of the first portion 351 and the width W _R3 of a portion of the second portion 352.

In addition to the features of the first embodiment described above, the third embodiment further has the following features.
<Feature D7>
The communicating flow path 350 includes a portion, in plan view, at a position between the first pressure chamber 331 and the second pressure chamber 332 and the nozzle 200, where the width of the communicating flow path 350 in the first direction Dr1 is a third width W _R3 that is smaller than the first width W _R1 of the communicating flow path 350 at a position that overlaps with the nozzle 200 in plan view. The portion having the third width W _R3 is part of the first portion 351, and extends a predetermined length in the second direction Dr2.

Similarly, the communicating flow path 350 includes a portion, in plan view, at a position between the pressure chamber 333 and the pressure chamber 334 and the nozzle 200, where the width of the communicating flow path 350 in the first direction Dr1 is a third width W _R3 that is smaller than the first width W _R1 of the communicating flow path 350 at a position overlapping with the nozzle 200. The portion having the third width W _R3 is part of the second portion 352, and extends a predetermined length in the second direction Dr2. It is preferable that the third width W _R3 in the first direction Dr1 of the first portion 351 and the third width W _R3 in the first direction Dr1 of the second portion 352 are equal to each other.

It is generally known that the faster the ink flow speed, the more likely variations in the concentration of particles contained in the ink are to occur. Therefore, if the ink flow speed directly above the nozzle 200 is fast, the concentration of particles contained in the ink directly above the nozzle will decrease. According to feature D7, the flow path width increases directly above the nozzle 200, reducing the flow speed directly above the nozzle 200, which has the effect of making it easier to uniformize the concentration of particles contained in the ink near the nozzle 200.

It is preferable that the following formula (4) be satisfied under the characteristic D7, and it is more preferable that the following formula (5) be satisfied.
0.1×W _C1 ≦(W _R1 −W _R3 )…(4)
0.2×W _C1 ≦(W _R1 −W _R3 )…(5)
That is, the value (W _R3 −W _R1 ) obtained by subtracting the first width W _R1 from the third width W _R3 is preferably 0.1 times or more, and more preferably 0.2 times or more, the pressure chamber width W _C1 .

It is also preferable that both of the following formulas (6a) and (6b) be satisfied.
(W _C1 ×1.5)<W _R1 ...(6a)
W _C1 ≦W _R3 <(W _C1 ×1.5) (6b)

The first width W _R1 is more preferably 1.5 times or more, more preferably 1.6 times or more, more preferably 1.7 times or more, more preferably 1.8 times or more, and even more preferably 1.9 times or more, the pressure chamber width W _C1 . Furthermore, it is particularly preferable that the first width W _R1 is equal to twice the pressure chamber width _{W C1} . Furthermore, the third width W _R3 is more preferably 1.5 times or less, more preferably 1.4 times or less, more preferably 1.3 times or less, more preferably 1.2 times or less, and even more preferably 1.1 times or less, the pressure chamber width W _C1 . Furthermore, it is particularly preferable that the third width W _R3 is equal to the pressure chamber width W _C1 .

The third embodiment preferably further has the following features.
<Feature D8>
The first length L _R1 in the second direction _Dr2 of the portion of the communicating flow path 350 having the first width W R1 is 4% to 30% of the total length L _R of the communicating flow path 350 in the second direction Dr2.
This feature D8 makes it possible to more uniformly reduce variations in the concentration of particles contained in the ink.

Considering the above-described first to third embodiments, it is preferable that the communication flow path 350 has the following features.
<Feature D9>
In a plan view, the average width in the first direction Dr1 of the communication flow path 350 from the pressure chambers 331, 332 to the pressure chambers 333, 334 is equal to or greater than the pressure chamber width W _C1 . Note that "communication flow path 350 from the pressure chambers 331, 332 to the pressure chambers 333, 334 in a plan view" refers to the portion of the communication flow path 350 between the pressure chambers 331, 332 and the pressure chambers 333, 334 in a plan view, and does not include the portions of the communication flow path 350 that overlap with the pressure chambers 331, 332 and the pressure chambers 333, 334 in a plan view.
According to this feature D9, the flow resistance of the communication flow path 350 can be sufficiently reduced.

Figures 11 to 13 are diagrams showing the shapes of the individual nozzle flow paths 130 in the fourth to sixth embodiments. The main difference between these fourth to sixth embodiments and the first embodiment shown in Figure 6 is the shape of the communicating flow path 350; the other configurations are substantially the same as those of the first embodiment. In the fourth embodiment shown in Figure 11, the communicating flow path 350 is entirely linear, as in the first embodiment, but extends in a direction tilted from the second direction Dr2. In the fifth embodiment shown in Figure 12 and the sixth embodiment shown in Figure 13, the communicating flow path 350 is bent midway. However, the fourth to sixth embodiments are similar to the first embodiment in that the entire communicating flow path 350 extends in the second direction Dr2. The fourth to sixth embodiments also preferably have features D1 to D4 described in the first embodiment. Furthermore, features D5 to D9 described above may also be applied to the fourth to sixth embodiments.

Fig. 14 is a diagram showing the shape of the nozzle-specific flow path 130 in the seventh embodiment. The main difference between the seventh embodiment and the first embodiment shown in Fig. 6 is the length L _R of the communication flow path 350 along the second direction Dr2, and the other configurations are substantially the same as those of the first embodiment. That is, in the seventh embodiment, the length L _R of the communication flow path 350 is shorter than in the first embodiment.

FIG. 14 also shows the length L _G of the communicating flow path 350 in the second direction Dr2 of the portion between the pressure chamber rows 330_L1 and 330_L2. This length L _G is preferably equal to or less than the first width W _R1 of the communicating flow path 350. Furthermore, this length L _G is preferably equal to or less than the length L _C1 of the pressure chamber 330 in the second direction Dr2. Furthermore, the overall length L _R of the communicating flow path 350 in the second direction Dr2 is preferably equal to or less than the length L _C1 of the pressure chamber 330 in the second direction Dr2. The first width W _R1 of the communicating flow path 350 may be smaller than the width W _C1 of the pressure chamber 330 in the first direction Dr1. That is, the seventh embodiment does not necessarily have the feature D1 described in the first embodiment. However, it is also possible to apply one or more of the features D1 to D9 described above to the seventh embodiment. In the seventh embodiment, the length L _R of the communication flow path 350 is short, so that the flow path resistance can be further reduced.

FIG. 15 is a diagram showing the nozzle-specific flow path 130 in the eighth embodiment. The eighth embodiment has N pressure chambers 330A and N pressure chambers 330B arranged side by side in the first direction Dr1, where N is an integer greater than or equal to 3. The N pressure chambers 330B are arranged at different positions in the second direction Dr2 from the set of N pressure chambers 330A. In the example of FIG. 15 , N is 3, but N may be 4 or greater. The N communication holes 340A connect the communication flow paths 350 to the N pressure chambers 330A, respectively, and the N communication holes 340B connect the communication flow paths 350 to the N pressure chambers 330B, respectively. Here, the pressure chamber 330A is an example of a "pressure chamber A," and the pressure chamber 330B is an example of a "pressure chamber B."

The eighth embodiment has the following features.
<Feature D10>
In a plan view looking toward the nozzle plate 240, when the width in the first direction Dr1 of the communicating flow path 350 at the position overlapping with the nozzle 200 is defined as a first width W _R1 and the width in the first direction Dr1 of the pressure chamber 330A is defined as a pressure chamber width W _C1 , W _C1 ≦W _R1 is satisfied.
This feature D10 corresponds to the feature D1 related to the first embodiment described above.

The eighth embodiment preferably further has the following features.
<Feature D11>
(N-1) x W _C1 ≦W _R1 ≦N x W _C1 is satisfied.
That is, it is preferable that the first width W _R1 is equal to or greater than (N−1) times and equal to or less than N times the pressure chamber width W _C1 .

In the eighth embodiment, similarly to the first embodiment described above, the width W _R1 of the communication flow passage 350 is wide, so that a decrease in injection efficiency can be suppressed. Note that some or all of the above-described features D2 to D9 may be adopted for the eighth embodiment.

Modification 1
In each of the above-described embodiments, a serial-type liquid ejection device 400 in which a carriage 434 holding the liquid ejection head 100 is reciprocated is exemplified, but the present disclosure can also be applied to a line-type liquid ejection device in which a plurality of nozzles 200 are distributed across the entire width of the medium PM. In other words, the carriage holding the liquid ejection head 100 is not limited to a serial-type carriage, and may be a structure that supports the liquid ejection head 100 in a line-type system. In this case, for example, a plurality of liquid ejection heads 100 are arranged side by side in the width direction of the medium PM, and the plurality of liquid ejection heads 100 are collectively held by a single carriage.

Modification 2
In each of the above-described embodiments, the liquid ejecting device 400 is exemplified as being equipped with the circulation mechanism 60, but the liquid ejecting device 400 does not have to be equipped with the circulation mechanism 60. In other words, both of the openings 161, 162 of the housing 160 may be inlets for introducing liquid from the liquid storage section 420, and both the first common liquid chamber 110 and the second common liquid chamber 120 may be used as flow paths for supplying the liquid supplied from the liquid storage section 420 to the nozzles 200.

Modification 3
In the above-described embodiments, one connection flow path 320 is connected to each of the pressure chambers 331 to 334, but a common connection flow path 320 may be provided for the pressure chambers 331 and 332 connected to the same first common liquid chamber 110. In other words, a configuration may be adopted in which one connection flow path 320 is provided corresponding to a plurality of pressure chambers 330. The same applies to the pressure chambers 333 and 334 connected to the same second common liquid chamber 120. When considering four individual flow paths corresponding to the individual pressure chambers 331 to 334 in Modification 3, for example, the first individual flow path does not include the connection flow path 320. The second to fourth individual flow paths can also be understood in a similar manner.

Modification 4
In each of the above-described embodiments, the connection flow path 320 is a flow path extending in the Z direction, but the connection flow path 320 may be a flow path extending in a direction intersecting the Z direction, or may be a flow path that includes both a portion extending in the Z direction and a portion extending in a direction intersecting the Z direction.

Variation 5
The liquid ejection apparatus exemplified in the above-described embodiment can be employed in various devices such as facsimile machines and copiers, as well as devices dedicated to printing. However, the uses of the liquid ejection apparatus are not limited to printing. For example, a liquid ejection apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus for forming color filters for display devices such as liquid crystal display panels. Furthermore, a liquid ejection apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming wiring and electrodes on a wiring board. Furthermore, a liquid ejection apparatus that ejects a solution of an organic substance related to a living body is used as a manufacturing apparatus for manufacturing biochips, for example.

Other forms:
The present disclosure is not limited to the above-described embodiments and can be realized in various forms without departing from the spirit thereof. For example, the present disclosure can also be realized in the following aspects. The technical features in the above embodiments corresponding to the technical features in each aspect described below can be appropriately replaced or combined to solve some or all of the problems of the present disclosure or to achieve some or all of the effects of the present disclosure. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

(1) A liquid jet head according to a first aspect of the present disclosure includes a nozzle plate in which a first nozzle for ejecting liquid is formed, first and second pressure chambers arranged side by side in a first direction, third and fourth pressure chambers arranged side by side in the first direction, flow paths extending along the nozzle plate, the flow paths being connected to the first nozzle and communicating with the first to fourth pressure chambers, a first common liquid chamber in first communication with the first and second pressure chambers, and a second common liquid chamber in communication with the third and fourth pressure chambers. The set of first and second pressure chambers and the set of third and fourth pressure chambers are arranged at different positions in a second direction perpendicular to the first direction. When a width in the first direction of the first communication path at a position overlapping with the first nozzle in a plan view looking toward the nozzle plate is defined as a first width, and a width in the first direction of the first pressure chamber is defined as a pressure chamber width, the first width is equal to or greater than the pressure chamber width.
According to this liquid jet head, since the width of the communication flow path is wide, it is possible to suppress a decrease in jet efficiency.

(2) In the above liquid jet head, the first width may be larger than the pressure chamber width.

(3) The first width may be 1.5 times or more the width of the pressure chamber.

(4) The first width may be less than or equal to twice the width of the pressure chamber.

(5) When the thickness direction of the nozzle plate is defined as a third direction and the height of the first communicating flow path in the third direction at the position where it overlaps with the first nozzle in the plan view is defined as a first height, the first width may be equal to or greater than the first height.
According to this liquid jet head, it is possible to ensure the rigidity of the members that form the communicating flow paths while reducing the flow path resistance of the communicating flow paths.

(6) A communication plate may be provided with the first communication flow path formed on a surface facing the nozzle plate, and when the thickness of the communication plate in the third direction at the position overlapping with the first nozzle in the plan view is defined as a first thickness, the first thickness may be greater than the first height.
According to this liquid jet head, the flow path resistance of the communication flow path can be reduced while ensuring the rigidity of the communication plate.

(7) The first communication flow path may include a portion, in the plan view, between the first and second pressure chambers and the first nozzle, whose width in the first direction is a second width greater than the first width.
According to this liquid jet head, the flow velocity can be increased near the nozzle.

(8) The value obtained by subtracting the first width from the second width may be 0.1 times or more the pressure chamber width.

(9) The liquid may be pseudoplastic.
According to this liquid jet head, it is easy to increase the flow rate near the nozzles and reduce the viscosity, so that ejection failures of pseudoplastic ink can be reduced.

(10) The first length in the second direction of the portion having the first width may be 4% or more and 30% or less of the total length in the second direction of the first communication flow path.
According to this liquid jet head, it is possible to reduce the viscosity of the pseudoplastic liquid in the vicinity of the nozzles while suppressing a decrease in jetting efficiency by reducing the flow path resistance up to just before the nozzles.

(11) The first communication flow path may include a portion, in the plan view, between the first and second pressure chambers and the first nozzle, whose width in the first direction is a third width smaller than the first width.
With this liquid jet head, it is known that the faster the liquid flow velocity, the more likely it is that the concentration of particles contained in the liquid will vary. Therefore, if the liquid flow velocity directly above the nozzle is fast, the concentration of particles contained in the liquid directly above the nozzle will decrease. By widening the flow path directly above the nozzle, the flow velocity directly above the nozzle will decrease, making it easier to homogenize the concentration of particles contained in the liquid near the nozzle.

(12) The value obtained by subtracting the third width from the first width may be 0.1 times or more the pressure chamber width.

(13) The first length in the second direction of the portion having the first width may be 4% or more and 30% or less of the total length in the second direction of the first communication flow path.
According to this liquid jet head, the particles in the liquid can be made uniform.

(14) The first common liquid chamber may be a flow path for supplying liquid to the first and second pressure chambers, and the second common liquid chamber may be a flow path for recovering liquid from the third and fourth pressure chambers.

(15) The average width in the first direction of the first communication flow path from the first and second pressure chambers to the third and fourth pressure chambers in the plan view may be equal to or greater than the width of the pressure chambers.

(16) The first communication flow path may have the second direction as its longitudinal direction.

(17) The first communication flow path may be a flow path common to the first to fourth pressure chambers.

(18) The nozzle plate has a second nozzle formed therein for ejecting liquid, and is equipped with fifth and sixth pressure chambers arranged side by side in the first direction, a set of the fifth and sixth pressure chambers being arranged at different positions in the second direction, seventh and eighth pressure chambers arranged side by side in the first direction, and second communication flow paths extending along the nozzle plate, connected to the second nozzles and communicating with the fifth to eighth pressure chambers. The first common liquid chamber communicates with the fifth and sixth pressure chambers, and the second common liquid chamber communicates with the seventh and eighth pressure chambers. When a first value is defined as twice the width in the first direction of a partition wall separating the first pressure chambers and the second pressure chambers, the width in the first direction of the partition wall separating the first communication flow path and the second communication flow path may be equal to or greater than the first value and equal to or less than a second value obtained by adding the width of the pressure chambers to the first value.

(19) A liquid jet head according to a second aspect of the present disclosure includes a nozzle plate in which nozzles for ejecting liquid are formed, N pressure chambers A arranged side by side in a first direction, where N is an integer equal to or greater than 3, N pressure chambers B arranged side by side in the first direction, wherein groups of the N pressure chambers A are arranged at different positions in a second direction perpendicular to the first direction, a communication flow path extending along the nozzle plate, the communication flow path being connected to the nozzle and communicating with the N pressure chambers A and the N pressure chambers B, a first common liquid chamber communicating with the N pressure chambers A, and a second common liquid chamber communicating with the N pressure chambers B. When a width in the first direction of the communication flow path at a position overlapping with the nozzle in a plan view looking toward the nozzle plate is defined as a first width, and a width in the first direction of the pressure chamber A is defined as a pressure chamber width, the first width is equal to or greater than the pressure chamber width.

(20) In the liquid jet head, the first width (W _R1 ) may be equal to or greater than (N−1) times and equal to or less than N times the pressure chamber width (W _C1 ).

(21) A liquid ejection device according to a third aspect of the present disclosure includes the liquid ejection head and a liquid storage section that stores liquid to be supplied to the liquid ejection head.

The present disclosure can also be realized in various forms other than liquid jet heads and liquid jet devices. For example, it can be realized in the form of a method for manufacturing a liquid jet head and a liquid jet device, a method for controlling a liquid jet head and a liquid jet device, a computer program for implementing that control method, a non-transitory recording medium on which that computer program is recorded, etc.

54...Vibration plate, 59...Wiring substrate, 60...Circulation mechanism, 61...First supply pump, 62...Second supply pump, 63...Storage container, 64...Recovery flow path, 65...Supply flow path, 70...Drive circuit, 100...Liquid jet head, 110...First common liquid chamber, 120...Second common liquid chamber, 130...Nozzle-specific flow path, 140...Communicating plate, 150...Sealing film, 160...Housing portion, 161, 162...Openings, 200...Nozzle, 240...Nozzle plate, 250...Pressure Force chamber substrate, 300, 301-304...drive element, 310...vibration plate, 320, 321-324...connecting flow path, 330, 331-334...pressure chamber, 340, 341-344...communicating hole, 350...communicating flow path, 351...first portion, 352...second portion, 353...third portion, 400...liquid ejection device, 420...liquid storage section, 430...movement mechanism, 432...belt, 434...carriage, 440...transport mechanism, 450...control unit

Claims (24)

a nozzle plate in which a first nozzle for ejecting liquid is formed;
First and second pressure chambers arranged side by side in a first direction;
third and fourth pressure chambers arranged side by side in the first direction;
a first communication flow path that is a flow path extending along the nozzle plate, connected to the first nozzle and communicating with the first to fourth pressure chambers;
a first common liquid chamber communicating with the first and second pressure chambers;
a second common liquid chamber communicating with the third and fourth pressure chambers;
Equipped with
the set of first and second pressure chambers and the set of third and fourth pressure chambers are arranged at different positions in a second direction perpendicular to the first direction,
a width in the first direction of the first communication flow channel at a position overlapping with the first nozzle in a plan view seen toward the nozzle plate is defined as a first width, and a width in the first direction of the first pressure chamber is defined as a pressure chamber width, the first width being equal to or greater than the pressure chamber width.
A liquid jet head characterized by: The first width is larger than the pressure chamber width.
The liquid jet head according to claim 1 . the first width is 1.5 times or more the width of the pressure chamber;
The liquid jet head according to claim 1 or 2. the first width is equal to or less than twice the width of the pressure chamber;
The liquid jet head according to claim 1 . a thickness direction of the nozzle plate is defined as a third direction, and a height of the first communication flow path in the third direction at the position overlapping with the first nozzle in the plan view is defined as a first height, the first width being equal to or greater than the first height.
The liquid jet head according to claim 1 . a communication plate having the first communication flow path formed on a surface facing the nozzle plate;
when a thickness of the communication plate in the third direction at the position overlapping with the first nozzle in the plan view is defined as a first thickness, the first thickness is greater than the first height;
The liquid jet head according to claim 5 . the first communication flow path includes a portion, in the plan view, between the first and second pressure chambers and the first nozzle, and the portion has a second width that is larger than the first width in the first direction;
The liquid jet head according to claim 1 . a value obtained by subtracting the first width from the second width is 0.1 times or more the pressure chamber width;
The liquid jet head according to claim 7 . The liquid has pseudoplastic properties.
The liquid jet head according to claim 7 or 8. a first length in the second direction of the portion having the first width is 4% or more and 30% or less of the entire length in the second direction of the first communication flow path,
The liquid jet head according to claim 7 . the first communication flow path includes a portion, in the plan view, between the first and second pressure chambers and the first nozzle, and the portion has a third width that is smaller than the first width in the first direction;
The liquid jet head according to claim 1 . a value obtained by subtracting the third width from the first width is 0.1 times or more the width of the pressure chamber;
The liquid jet head according to claim 11. a first length in the second direction of the portion having the first width is 4% or more and 30% or less of the entire length in the second direction of the first communication flow path,
The liquid jet head according to claim 11 or 12. the first common liquid chamber is a flow path for supplying liquid to the first and second pressure chambers,
the second common liquid chamber is a flow path for recovering liquid from the third and fourth pressure chambers;
The liquid jet head according to claim 1 . an average value of a width in the first direction of the first communication flow path from the first and second pressure chambers to the third and fourth pressure chambers in the plan view is equal to or greater than a width of the pressure chambers;
The liquid jet head according to claim 1 . The first communication flow path has the second direction as its longitudinal direction.
The liquid jet head according to claim 1 . the first communication flow path is a flow path common to the first to fourth pressure chambers;
The liquid jet head according to claim 1 . a second nozzle for ejecting a liquid is formed in the nozzle plate;
fifth and sixth pressure chambers arranged side by side in the first direction;
seventh and eighth pressure chambers arranged side by side in the first direction and disposed at positions different from the fifth and sixth pressure chamber sets in the second direction;
a second communication flow path that is a flow path extending along the nozzle plate, connected to the second nozzle and communicating with the fifth to eighth pressure chambers;
Equipped with
the first common liquid chamber communicates with the fifth and sixth pressure chambers,
the second common liquid chamber communicates with the seventh and eighth pressure chambers,
when a first value is twice the width in the first direction of a partition wall that separates the first pressure chamber and the second pressure chamber, the width in the first direction of the partition wall that separates the first communication flow path and the second communication flow path is equal to or greater than the first value and is equal to or less than a second value obtained by adding the width of the pressure chamber to the first value,
The liquid jet head according to claim 1 . a nozzle plate in which nozzles for ejecting liquid are formed;
N pressure chambers A arranged side by side in a first direction, where N is an integer of 3 or more;
N pressure chambers B arranged in a line in the first direction and disposed at positions different from the set of N pressure chambers A in a second direction perpendicular to the first direction;
a communication flow path that is a flow path extending along the nozzle plate, connected to the nozzle and communicating with the N pressure chambers A and the N pressure chambers B;
a first common liquid chamber communicating with the N pressure chambers A;
a second common liquid chamber communicating with the N pressure chambers B;
Equipped with
a width of the communication flow channel in the first direction at a position overlapping with the nozzle in a plan view seen toward the nozzle plate is defined as a first width, and a width of the pressure chamber A in the first direction is defined as a pressure chamber width, the first width being equal to or greater than the pressure chamber width.
Liquid injection head. the first width is equal to or greater than (N-1) times and equal to or less than N times the width of the pressure chamber;
The liquid jet head according to claim 19. a nozzle plate in which nozzles for ejecting liquid are formed;
First and second pressure chambers arranged side by side in a first direction;
third and fourth pressure chambers arranged side by side in the first direction;
a communication flow path extending along the nozzle plate, the communication flow path being connected to the nozzle and communicating with the first to fourth pressure chambers;
a first common liquid chamber communicating with the first and second pressure chambers;
a second common liquid chamber communicating with the third and fourth pressure chambers;
Equipped with
the set of first and second pressure chambers and the set of third and fourth pressure chambers are arranged at different positions in a second direction perpendicular to the first direction,
a length in the second direction of a portion of the communication flow path between the first pressure chamber and the third pressure chamber is equal to or less than a length in the second direction of the first pressure chamber;
A liquid jet head characterized by: a nozzle plate in which nozzles for ejecting liquid are formed;
First and second pressure chambers arranged side by side in a first direction;
third and fourth pressure chambers arranged side by side in the first direction;
a communication flow path extending along the nozzle plate, the communication flow path being connected to the nozzle and communicating with the first to fourth pressure chambers;
a first common liquid chamber communicating with the first and second pressure chambers;
a second common liquid chamber communicating with the third and fourth pressure chambers;
Equipped with
the set of first and second pressure chambers and the set of third and fourth pressure chambers are arranged at different positions in a second direction perpendicular to the first direction,
a length in the second direction of a portion of the communication flow path between the first pressure chamber and the third pressure chamber is equal to or less than a width in the first direction of the communication flow path at a position overlapping with the nozzle in a plan view seen toward the nozzle plate;
A liquid jet head characterized by: a nozzle plate in which nozzles for ejecting liquid are formed;
First and second pressure chambers arranged side by side in a first direction;
third and fourth pressure chambers arranged side by side in the first direction;
a communication flow path extending along the nozzle plate, the communication flow path being connected to the nozzle and communicating with the first to fourth pressure chambers;
a first common liquid chamber communicating with the first and second pressure chambers;
a second common liquid chamber communicating with the third and fourth pressure chambers;
Equipped with
the set of first and second pressure chambers and the set of third and fourth pressure chambers are disposed at different positions in a second direction perpendicular to the first direction,
a first pressure chamber that is formed in the second direction and has a first pressure chamber that is formed in the second direction; A liquid jet head according to any one of claims 1 to 23;
a liquid storage section that stores the liquid to be supplied to the liquid jet head;
A liquid ejection device comprising: