阅读说明：本技术 头芯片、液体喷射头以及液体喷射记录装置 (Head chip, liquid ejecting head, and liquid ejecting recording apparatus ) 是由 蓝知季 山村祐树 平田雅一 铃木研治 于 2020-11-27 设计创作，主要内容包括：本发明提供能够使印刷画质提高的头芯片等。本公开的一个实施方式所涉及的头芯片具备：促动器板,其具有多个吐出槽；以及喷嘴板,其具有与多个吐出槽单独地连通的多个喷嘴孔。上述多个吐出槽以它们的至少一部分沿既定方向相互重合的方式并列配置。另外,上述多个喷嘴孔之中的沿上述既定方向邻接的喷嘴孔彼此在喷嘴板内沿吐出槽的延伸方向相互偏离地配置。(The invention provides a head chip and the like capable of improving printing image quality. A head chip according to an embodiment of the present disclosure includes: an actuator plate having a plurality of discharge grooves; and a nozzle plate having a plurality of nozzle holes individually communicating with the plurality of discharge grooves. The plurality of discharge grooves are arranged in parallel so that at least a part of the discharge grooves overlap each other in a predetermined direction. Further, among the plurality of nozzle holes, nozzle holes adjacent to each other in the predetermined direction are arranged to be offset from each other in the extending direction of the discharge groove in the nozzle plate.)

1. A head chip for ejecting liquid, comprising:

an actuator plate having a plurality of discharge grooves; and

a nozzle plate having a plurality of nozzle holes individually communicating with the plurality of discharge grooves;

the plurality of discharge grooves are arranged in parallel so that at least a part of the discharge grooves overlap each other in a predetermined direction,

among the plurality of nozzle holes, nozzle holes adjacent to each other in the predetermined direction are arranged in the nozzle plate so as to be offset from each other in the extending direction of the discharge groove.

2. The head chip according to claim 1,

the discharge grooves are arranged so as to be entirely overlapped with each other in the predetermined direction,

the discharge grooves are arranged in a row in the predetermined direction as a whole.

3. The head chip according to claim 2,

further provided is a cover plate having: a first through-hole for allowing the liquid to flow into the discharge groove, a second through-hole for allowing the liquid to flow out of the discharge groove, and a wall portion covering the discharge groove,

the through hole pairs of the first through hole and the second through hole of each discharge groove are arranged in parallel in the extending direction of the discharge groove,

the length of the wall portion along the extending direction of the discharge groove, which corresponds to the distance between the first through-hole and the second through-hole in the pair of through-holes, is the same in all the pairs of through-holes, and

the size relationship between a first opening length that is a length of the first through-hole in the extending direction of the discharge groove and a second opening length that is a length of the second through-hole in the extending direction of the discharge groove is alternately changed between the pairs of through-holes adjacent to each other in the predetermined direction.

4. The head chip according to claim 3,

the cover plate further has:

a first common flow path extending in the predetermined direction while communicating with each of the first through holes of each of the pair of through holes; and

a second common flow path extending in the predetermined direction and communicating with each of the second through-holes of each of the through-hole pairs,

a first channel width that is a length of the first common channel in a direction orthogonal to the predetermined direction is constant in the predetermined direction, and

a second channel width that is a length of the second common channel in a direction orthogonal to the predetermined direction is constant in the predetermined direction.

5. The head chip according to claim 3,

the cover plate further has:

a first common flow path extending in the predetermined direction while communicating with each of the first through holes of each of the pair of through holes; and

a second common flow path extending in the predetermined direction and communicating with each of the second through-holes of each of the through-hole pairs,

a first flow path width that is a length of the first common flow path in a direction orthogonal to the predetermined direction, varies in the predetermined direction in correspondence with an alternate variation in the first opening length of the through hole pair adjacent to each other in the predetermined direction, and

a second flow path width, which is a length of the second common flow path in a direction orthogonal to the predetermined direction, changes in the predetermined direction in accordance with an alternate change in the length of the second opening in the pair of through holes adjacent to each other in the predetermined direction.

6. The head chip according to claim 1,

a part of the plurality of discharge grooves are arranged so as to overlap each other in the predetermined direction,

the discharge grooves are arranged in a staggered manner in the predetermined direction as a whole.

7. The head chip according to claim 6,

further provided is a cover plate having: a first through-hole for allowing the liquid to flow into the discharge groove, a second through-hole for allowing the liquid to flow out of the discharge groove, and a wall portion covering the discharge groove,

the through hole pairs of the first through hole and the second through hole of each discharge groove are arranged in parallel in the extending direction of the discharge groove,

the length of the wall portion along the extending direction of the discharge groove, which corresponds to the distance between the first through-hole and the second through-hole in the pair of through-holes, is the same in all the pairs of through-holes, and

a first opening length that is a length of the first through-hole in the extending direction of the discharge groove and a second opening length that is a length of the second through-hole in the extending direction of the discharge groove are identical to each other,

the first through holes and the second through holes are respectively arranged in a staggered manner along the predetermined direction.

8. The head chip according to any one of claim 1 to claim 7,

the actuator plate further has a plurality of non-discharge grooves arranged in parallel in the predetermined direction, and

the discharge grooves and the non-discharge grooves are alternately arranged in the predetermined direction,

one side of the non-discharge groove along the extending direction of the non-discharge groove is a curved side surface in which the cross-sectional area of the non-discharge groove gradually decreases toward the nozzle plate side, and

the other side of the non-discharge groove along the extending direction of the non-discharge groove is open to an end of the actuator plate along the extending direction of the non-discharge groove.

9. A liquid ejecting head comprising the head chip according to any one of claims 1 to 8.

10. A liquid ejecting recording apparatus comprising the liquid ejecting head according to claim 9.

Technical Field

The present disclosure relates to a head chip, a liquid ejection head, and a liquid ejection recording apparatus.

Background

Liquid ejecting recording apparatuses including liquid ejecting heads are used in various fields, and various types of liquid ejecting heads have been developed as the liquid ejecting heads (for example, see patent document 1). In addition, the liquid ejecting head is provided with a head chip that ejects ink (liquid).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2004-174857.

Disclosure of Invention

Problems to be solved by the invention

In such a head chip, generally, it is required to improve the print image quality. It is desirable to provide a head chip, a liquid ejecting head, and a liquid ejecting recording apparatus capable of improving print image quality.

Means for solving the problems

A head chip according to an embodiment of the present disclosure includes: an actuator plate having a plurality of discharge grooves; and a nozzle plate having a plurality of nozzle holes individually communicating with the plurality of discharge grooves. The plurality of discharge grooves are arranged in parallel so that at least a part of the discharge grooves overlap each other in a predetermined direction. Further, among the plurality of nozzle holes, nozzle holes adjacent to each other in the predetermined direction are arranged to be offset from each other in the extending direction of the discharge groove in the nozzle plate.

A liquid ejecting head according to an embodiment of the present disclosure includes a head chip according to an embodiment of the present disclosure.

A liquid ejecting recording apparatus according to an embodiment of the present disclosure includes the liquid ejecting head according to the embodiment of the present disclosure.

Effects of the invention

According to the head chip, the liquid ejecting head, and the liquid ejecting recording apparatus according to the embodiment of the present disclosure, the print image quality can be improved.

Drawings

Fig. 1 is a schematic perspective view showing an example of a schematic configuration of a liquid jet recording apparatus according to an embodiment of the present disclosure.

Fig. 2 is a schematic bottom view showing a configuration example of the liquid ejecting head in a state where the nozzle plate is detached.

Fig. 3 is a schematic diagram showing an example of a cross-sectional structure along the line III-III shown in fig. 2.

Fig. 4 is a schematic diagram showing an example of a cross-sectional structure along the line IV-IV shown in fig. 2.

Fig. 5 is a schematic diagram showing a top-view configuration example of the liquid ejecting head on the upper surface side of the cap plate shown in fig. 3 and 4.

Fig. 6 is a schematic diagram showing a top view configuration example of the vicinity of the end portion of the actuator plate shown in fig. 3 and 4.

Fig. 7 is a schematic bottom view showing a configuration example of a state in which the nozzle plate is detached in the liquid jet head according to the comparative example.

Fig. 8 is a schematic diagram showing an example of a cross-sectional structure taken along line VIII-VIII shown in fig. 7.

Fig. 9 is a schematic diagram showing a configuration example in a plan view of the upper surface side of the cap plate in the liquid jet head according to modification 1.

Fig. 10 is a schematic diagram showing an example of a cross-sectional configuration of the liquid jet head according to modification 1.

Fig. 11 is a schematic diagram showing another example of the cross-sectional configuration of the liquid jet head according to modification 1.

Fig. 12 is a schematic diagram showing a configuration example in a plan view of the upper surface side of the cap plate in the liquid jet head according to modification 2.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description is made in the following order.

1. Embodiment (example of configuration in which nozzle holes are arranged alternately and discharge grooves are arranged in a row)

2. Modification example

Modification 1 (example of a configuration in which the flow channel width of the common flow channel changes in accordance with the opening length of the through-hole)

Modification 2 (example of a configuration in which nozzle holes and discharge grooves are arranged alternately)

3. Other modifications are possible.

<1 > embodiment >

[ A. integral Structure of Printer 1]

Fig. 1 schematically shows a schematic configuration example of a printer 1 as a liquid jet recording apparatus according to an embodiment of the present disclosure in a perspective view. The printer 1 is an ink jet printer that records (prints) an image, characters, and the like on a recording paper P as a recording medium with ink 9 described later. The recording medium is not limited to paper, and may be made of a material capable of being recorded, such as ceramic or glass.

As shown in fig. 1, the printer 1 includes a pair of transport mechanisms 2a and 2b, an ink tank 3, an inkjet head 4, a circulation flow path 50, and a scanning mechanism 6. These components are accommodated in a frame body 10 having a predetermined shape. In the drawings used in the description of the present specification, the scale of each member is appropriately changed so that each member can be recognized.

Here, the printer 1 corresponds to a specific example of the "liquid ejecting recording apparatus" in the present disclosure, and the inkjet heads 4 (the inkjet heads 4Y, 4M, 4C, and 4K described later) correspond to a specific example of the "liquid ejecting head" in the present disclosure. The ink 9 corresponds to a specific example of "liquid" in the present disclosure.

The transport mechanisms 2a and 2b are each a mechanism for transporting the recording paper P in the transport direction d (X-axis direction) as shown in fig. 1. These conveying mechanisms 2a and 2b each include a grid roller 21, a pinch roller 22, and a drive mechanism (not shown). The drive mechanism is a mechanism for rotating the grid roller 21 around the axis (rotating in the Z-X plane), and is constituted by a motor or the like, for example.

(ink tank 3)

The ink tank 3 is a tank that contains ink 9 therein. As shown in fig. 1, in this example, four ink tanks each containing four color inks 9 of yellow (Y), magenta (M), cyan (C), and black (K) are provided as the ink tanks 3. That is, an ink tank 3Y containing yellow ink 9, an ink tank 3M containing magenta ink 9, an ink tank 3C containing cyan ink 9, and an ink tank 3K containing black ink 9 are provided. These ink tanks 3Y, 3M, 3C, and 3K are arranged in parallel along the X-axis direction in the housing 10.

Since the ink tanks 3Y, 3M, 3C, and 3K have the same configuration except for the color of the ink 9 to be contained, they will be collectively referred to as the ink tanks 3 hereinafter.

(ink-jet head 4)

The inkjet head 4 is a head that ejects (discharges) droplet-shaped ink 9 from a plurality of nozzles (nozzle holes H1, H2) described later onto a recording sheet P to record (print) images, characters, and the like. As shown in fig. 1, the ink jet head 4 of this example is also provided with four heads that individually eject the four color inks 9 contained in the ink tanks 3Y, 3M, 3C, and 3K. That is, an ink jet head 4Y that ejects yellow ink 9, an ink jet head 4M that ejects magenta ink 9, an ink jet head 4C that ejects cyan ink 9, and an ink jet head 4K that ejects black ink 9 are provided. These ink jet heads 4Y, 4M, 4C, and 4K are arranged in parallel along the Y axis direction in the housing 10.

Since the inkjet heads 4Y, 4M, 4C, and 4K have the same configuration except for the color of the ink 9 used, they will be collectively described as the inkjet head 4 below. Further, a detailed configuration example of the ink jet head 4 will be described later (fig. 2 to 6).

(circulation flow path 50)

The circulation channel 50 has channels 50a and 50b as shown in fig. 1. The flow path 50a is a portion that reaches the inkjet head 4 from the ink tank 3 via a liquid feed pump (not shown). The flow path 50b is a portion that reaches the ink tank 3 from the inkjet head 4 via a liquid feed pump (not shown). In other words, the flow path 50a is a flow path through which the ink supply water 9 flows from the ink tank 3 toward the inkjet head 4. The flow path 50b is a flow path through which the ink 9 flows from the inkjet head 4 to the ink tank 3.

In this manner, in the present embodiment, the ink 9 circulates between the inside of the ink tank 3 and the inside of the ink jet head 4. The flow paths 50a and 50b (supply pipes for the ink 9) are each formed of, for example, a flexible hose having flexibility.

(scanning mechanism 6)

The scanning mechanism 6 is a mechanism for scanning the inkjet head 4 in the width direction (Y-axis direction) of the recording paper P. As shown in fig. 1, the scanning mechanism 6 includes a pair of guide rails 61a and 61b extending in the Y-axis direction, a carriage 62 movably supported by the guide rails 61a and 61b, and a drive mechanism 63 for moving the carriage 62 in the Y-axis direction.

The drive mechanism 63 includes a pair of pulleys 631a and 631b disposed between the guide rails 61a and 61b, an endless belt 632 wound around the pulleys 631a and 631b, and a drive motor 633 for driving the pulley 631a to rotate. The four ink jet heads 4Y, 4M, 4C, and 4K are arranged in parallel in the Y axis direction on the carriage 62.

The scanning mechanism 6 and the transport mechanisms 2a and 2b constitute a moving mechanism for relatively moving the inkjet head 4 and the recording paper P. The moving mechanism is not limited to this type, and may be, for example, the following type (so-called "single pass type"): the inkjet heads 4 are fixed while only the recording medium (recording paper P) is moved, so that the inkjet heads 4 and the recording medium are moved differently.

[ detailed Structure of ink-jet head 4 ]

Next, a detailed configuration example of the ink jet head 4 (head chip 41) will be described with reference to fig. 2 to 6 in addition to fig. 1.

Fig. 2 schematically shows an example of the structure of the ink-jet head 4 in a state where the nozzle plate 411 is removed (appearing later) in a bottom view (X-Y bottom view). Fig. 3 schematically shows an example of the sectional structure (an example of the Y-Z sectional structure) of the ink-jet head 4 along the line III-III shown in fig. 2. Similarly, fig. 4 schematically shows an example of the cross-sectional structure (an example of the Y-Z cross-sectional structure) of the ink-jet head 4 along the line IV-IV shown in fig. 2. Fig. 5 schematically shows a top view configuration example (X-Y top view configuration example) of the inkjet head 4 on the upper surface side of the cap 413 (appearing later) shown in fig. 3 and 4. Fig. 6 schematically shows an example of a top view configuration (an X-Y top view configuration) of the actuator plate 412 (shown later) shown in fig. 3 and 4 in the vicinity of the end portion along the Y-axis direction.

Note that, in fig. 3 to 6, the discharge channel C1e and the nozzle hole H1, which are disposed corresponding to the nozzle row An1 described later, among the discharge channels C1e and C2e described later and the nozzle holes H1 and H2 described later, are representatively illustrated for convenience. That is, the discharge channel C2e and the nozzle hole H2 arranged corresponding to the nozzle row An2 described later have the same configuration, and therefore, the illustration thereof is omitted.

The ink jet head 4 of the present embodiment is a so-called side-shooter type ink jet head that ejects ink 9 from a central portion in the extending direction (Y axis direction) of a plurality of channels (a plurality of channels C1 and a plurality of channels C2) in a head chip 41 described later. The ink jet head 4 is a circulation type ink jet head that circulates and utilizes the ink 9 between the ink tank 3 and the circulation flow path 50.

As shown in fig. 3 and 4, the inkjet head 4 includes a head chip 41. The ink jet head 4 is provided with a circuit board and a Flexible Printed Circuit (FPC) as a control means (a means for controlling the operation of the head chip 41) which is not shown.

The circuit board is a board on which a drive circuit (electric circuit) for driving the head chip 41 is mounted. The flexible printed board is a board for electrically connecting a drive circuit on the circuit board and a drive electrode Ed to be described later in the head chip 41. In addition, in such a flexible printed circuit board, a plurality of lead electrodes are printed and wired.

As shown in fig. 3 and 4, the head chip 41 is a member for ejecting the ink 9 in the Z-axis direction, and is configured using various kinds of plates. Specifically, as shown in fig. 3 and 4, the head chip 41 mainly includes a nozzle plate (ejection orifice plate) 411, an actuator plate 412, and a cover plate 413. The nozzle plate 411, the actuator plate 412, and the cover plate 413 are bonded to each other using, for example, an adhesive, and are stacked in this order along the Z-axis direction. Hereinafter, the cover 413 side is referred to as an upper side and the nozzle plate 411 side is referred to as a lower side along the Z-axis direction.

(nozzle plate 411)

The nozzle plate 411 is made of a film material such as polyimide having a thickness of, for example, about 50 μm, and is bonded to the lower surface of the actuator plate 412 as shown in fig. 3 and 4. However, the material of the nozzle plate 411 is not limited to a resin material such as polyimide, and may be a metal material, for example.

As shown in fig. 2, two nozzle rows (nozzle rows An1, An2) extending in the X-axis direction are provided in the nozzle plate 411. These nozzle rows An1, An2 are arranged at predetermined intervals along the Y axis direction. As described above, the ink jet head 4 (head chip 41) of the present embodiment is a two-line type ink jet head (head chip).

As will be described in detail later, the nozzle row An1 includes a plurality of nozzle holes H1 formed in parallel at predetermined intervals in the X-axis direction. The nozzle holes H1 each penetrate the nozzle plate 411 in the thickness direction (Z-axis direction), and communicate individually with the inside of a discharge passage C1e in the actuator plate 412 described later, as shown in fig. 3 and 4, for example. The formation pitch of the nozzle holes H1 in the X-axis direction is the same as (the same pitch as) the formation pitch of the discharge channel C1e in the X-axis direction. As will be described later in detail, the ink 9 supplied from the discharge channel C1e is discharged (ejected) from the nozzle hole H1 in such a nozzle row An 1.

As will be described in detail later, the nozzle row An2 similarly has a plurality of nozzle holes H2 formed in parallel at predetermined intervals in the X-axis direction. The nozzle holes H2 each penetrate the nozzle plate 411 in the thickness direction thereof and individually communicate with the inside of a discharge passage C2e in the actuator plate 412, which will be described later. The formation pitch of the nozzle holes H2 in the X axis direction is the same as the formation pitch of the discharge channel C2e in the X axis direction. As will be described in detail later, the ink 9 supplied from the discharge channel C2e is also discharged from the nozzle hole H2 in such a nozzle row An 2.

As shown in fig. 2, the nozzle holes H1 in the nozzle row An1 and the nozzle holes H2 in the nozzle row An2 are arranged so as to be shifted in the X-axis direction. Therefore, in the ink-jet head 4 of the present embodiment, the nozzle holes H1 in the nozzle row An1 and the nozzle holes H2 in the nozzle row An2 are arranged in a staggered shape (staggered arrangement). The nozzle holes H1 and H2 are tapered through-holes each having a diameter that gradually decreases downward (see fig. 3 and 4).

Here, in the nozzle plate 411 of the present embodiment, as shown in fig. 2, among the plurality of nozzle holes H1 in the nozzle row An1, the nozzle holes H1 adjacent in the X-axis direction are arranged offset from each other along the extending direction (Y-axis direction) of the discharge channel C1 e. That is, the nozzle holes H1 in the nozzle row An1 are arranged in a staggered manner in the X-axis direction as a whole. Specifically, as shown in fig. 2, the plurality of nozzle holes H1 in the nozzle row An1 includes a plurality of nozzle holes H11 belonging to a nozzle row An11 extending in the X-axis direction, and a plurality of nozzle holes H12 belonging to a nozzle row An12 extending in the X-axis direction. The nozzle holes H11 are arranged offset toward the positive side in the Y-axis direction (the first supply slit Sin1 side described later) with respect to the center position of the discharge channel C1e in the extending direction (Y-axis direction). On the other hand, the nozzle holes H12 are arranged offset to the negative side in the Y-axis direction (the first discharge slit Sout1 side described later) with respect to the center position of the discharge channel C1e in the extending direction.

Similarly, in the nozzle plate 411, as shown in fig. 2, among the nozzle holes H2 in the nozzle row An2, the nozzle holes H2 adjacent in the X-axis direction are arranged offset from each other along the extending direction (Y-axis direction) of the discharge channel C2 e. That is, the nozzle holes H2 in the nozzle row An2 are arranged in a staggered manner in the X-axis direction as a whole. Specifically, as shown in fig. 2, the plurality of nozzle holes H2 in the nozzle row An2 includes a plurality of nozzle holes H21 belonging to a nozzle row An21 extending in the X-axis direction, and a plurality of nozzle holes H22 belonging to a nozzle row An22 extending in the X-axis direction. The nozzle holes H21 are arranged offset to the negative side in the Y-axis direction (the second supply slit side described later) with respect to the center position of the discharge channel C2e in the extending direction (Y-axis direction). On the other hand, the nozzle holes H22 are arranged offset toward the positive side in the Y-axis direction (the second discharge slit side described later) with respect to the center position of the discharge channel C2e in the extending direction.

Further, details of the arrangement structure of such nozzle holes H1(H11, H12) and H2(H21, H22) will be described later.

(actuator plate 412)

The actuator plate 412 is a plate made of a piezoelectric material such as PZT (lead zirconate titanate). As shown in fig. 3 and 4, the actuator plate 412 is formed by laminating two piezoelectric substrates having different polarization directions along the thickness direction (Z-axis direction) (so-called chevron type). However, the structure of the actuator plate 412 is not limited to the chevron type. That is, the actuator plate 412 (so-called cantilever type) may also be constituted by one (single) piezoelectric substrate in which the polarization direction is set unidirectionally along the thickness direction (Z-axis direction), for example.

As shown in fig. 2, two rows of passage rows (passage rows 421 and 422) extending in the X-axis direction are provided in the actuator plate 412. These channel rows 421 and 422 are arranged at predetermined intervals along the Y-axis direction.

As shown in fig. 2, the actuator plate 412 has a discharge region (ejection region) for the ink 9 in the center portion (formation region of the channel rows 421 and 422) along the X-axis direction. On the other hand, in the actuator plate 412, non-discharge regions (non-ejection regions) of the ink 9 are provided at both end portions (non-formation regions of the channel rows 421, 422) in the X axis direction. The non-discharge region is located outside the discharge region in the X-axis direction. Both ends of the actuator plate 412 in the Y-axis direction constitute tail portions 420 as shown in fig. 2.

The channel row 421 has a plurality of channels C1 as shown in fig. 2. These passages C1 extend in the Y-axis direction within the actuator plate 412 as shown in fig. 2. As shown in fig. 2, the channel rows C1 are arranged in parallel with each other at predetermined intervals in the X-axis direction. Each channel C1 is defined by a drive wall Wd formed of a piezoelectric body (actuator plate 412), and is a concave groove portion in a cross-sectional view taken along the Z-X direction.

The channel row 422 also has a plurality of channels C2 extending in the Y-axis direction, as shown in fig. 2. As shown in fig. 2, the passage rows C2 are arranged in parallel with each other at predetermined intervals in the X-axis direction. Each passage C2 is also delimited by the above-described drive wall Wd and is a concave groove portion in a cross-sectional view taken along the Z-X plane.

Here, as shown in fig. 2 to 6, the channel C1 includes a discharge channel C1e (discharge groove) for discharging the ink 9 and a dummy channel C1d (non-discharge groove) for not discharging the ink 9. Each of the discharge channels C1e communicates with a nozzle hole H1 in the nozzle plate 411 (see fig. 3 and 4), while each of the dummy channels C1d does not communicate with the nozzle hole H1 and is covered from below by the upper surface of the nozzle plate 411.

The plurality of discharge passages C1e are arranged in parallel so that at least a part of them overlap each other in the predetermined direction (X-axis direction), and particularly in the example of fig. 2, the entirety of the plurality of discharge passages C1e is arranged so as to overlap each other in the X-axis direction. Thus, as shown in fig. 2, the discharge passages C1e are arranged in a row in the X-axis direction as a whole. Similarly, the plurality of dummy channels C1d are arranged in parallel in the X-axis direction, and in the example of fig. 2, the plurality of dummy channels C1d are arranged in a row in the X-axis direction as a whole. In the channel row 421, the discharge channels C1e and the dummy channels C1d are alternately arranged in the X-axis direction (see fig. 2).

As shown in fig. 2 to 4, the channel C2 includes a discharge channel C2e (discharge groove) for discharging the ink 9 and a dummy channel C2d (non-discharge groove) for not discharging the ink 9. Each of the discharge channels C2e communicates with the nozzle hole H2 in the nozzle plate 411, while each of the dummy channels C2d does not communicate with the nozzle hole H2 and is covered from below by the upper surface of the nozzle plate 411 (see fig. 3 and 4).

The plurality of discharge passages C2e are arranged in parallel so that at least a part of them overlap each other in the predetermined direction (X-axis direction), and particularly in the example of fig. 2, the entirety of the plurality of discharge passages C2e is arranged so as to overlap each other in the X-axis direction. Thus, as shown in fig. 2, the discharge passages C2e are arranged in a row in the X-axis direction as a whole. Similarly, the plurality of dummy channels C2d are arranged in parallel in the X-axis direction, and in the example of fig. 2, the plurality of dummy channels C2d are arranged in a row in the X-axis direction as a whole. In the channel row 422, the discharge channels C2e and the dummy channels C2d are alternately arranged in the X-axis direction (see fig. 2).

Note that the discharge passages C1e and C2e correspond to a specific example of "discharge grooves" in the present disclosure, and the dummy passages C1d and C2d correspond to a specific example of "non-discharge grooves" in the present disclosure. The X-axis direction corresponds to a specific example of "predetermined direction" in the present disclosure, and the Y-axis direction corresponds to a specific example of "extending direction of discharge groove" in the present disclosure.

Here, as shown in fig. 2 to 4, the discharge passage C1e in the passage row 421 and the dummy passage C2d in the passage row 422 are arranged on a straight line along the extending direction (Y-axis direction) of the discharge passage C1e and the dummy passage C2 d. As shown in fig. 2, the dummy channel C1d in the channel row 421 and the discharge channel C2e in the channel row 422 are arranged on a straight line along the extending direction (Y-axis direction) of the dummy channel C1d and the discharge channel C2 e.

As shown in fig. 4, for example, each discharge passage C1e has an arc-shaped side surface in which the cross-sectional area of each discharge passage C1e gradually decreases from the cover plate 413 side (upper side) toward the nozzle plate 411 side (lower side). Similarly, each discharge passage C2e has an arc-shaped side surface in which the cross-sectional area of each discharge passage C2e gradually decreases from the cover plate 413 side toward the nozzle plate 411 side. The arcuate side surfaces of the discharge passages C1e and C2e are formed by cutting with a cutter, for example.

The detailed structure of the vicinity of the discharge path C1e (and the vicinity of the discharge path C2e) shown in fig. 3 and 4 will be described later.

As shown in fig. 3, 4, and 6, the drive wall Wd is provided with drive electrodes Ed extending in the Y-axis direction on inner surfaces facing each other in the X-axis direction. The drive electrode Ed includes a common electrode (common electrode) Edc provided on an inner surface facing the discharge channels C1e and C2e and a separate electrode (active electrode) Eda provided on an inner surface facing the dummy channels C1d and C2 d. Such drive electrodes Ed (common electrode Edc and individual electrode Eda) are formed on the inner surfaces of the drive walls Wd over the entire depth direction (Z-axis direction) (see fig. 3 and 4).

The pair of common electrodes Edc facing each other in the same discharge channel C1e (or the discharge channel C2e) are electrically connected to each other at a common terminal (common wiring) not shown. In addition, the pair of individual electrodes Eda facing each other in the same dummy channel C1d (or dummy channel C2d) are electrically isolated from each other. On the other hand, the pair of individual electrodes Eda facing each other through the discharge channel C1e (or the discharge channel C2e) are electrically connected to each other at individual terminals (individual wires) not shown.

Here, the flexible printed board for electrically connecting the driving electrodes Ed and the circuit board is attached to the tail portion 420 (the vicinity of the end portion of the actuator plate 412 in the Y-axis direction). A wiring pattern (not shown) formed on the flexible printed circuit board is electrically connected to the common wiring and the individual wiring. Thus, a drive voltage is applied to each drive electrode Ed from the drive circuit on the circuit board via the flexible printed board.

In the tail portion 420 of the actuator plate 412, the end portions of the dummy channels C1d and C2d in the extending direction (Y-axis direction) are configured as follows.

That is, first, in the dummy passages C1d and C2d, one side thereof in the extending direction is an arc-shaped side surface in which the cross-sectional area of each dummy passage C1d and C2d gradually decreases toward the nozzle plate 411 (see fig. 3 and 4). The arc-shaped side surfaces of the dummy channels C1d and C2d are also formed by cutting with a cutter, for example, in the same manner as the arc-shaped side surfaces of the discharge channels C1e and C2 e. On the other hand, in the dummy channels C1d and C2d, the other sides (tail 420 sides) thereof in the extending direction open up to the end of the actuator plate 412 in the Y-axis direction (see the symbol P2 indicated by the broken line in fig. 3, 4, and 6). As shown in fig. 3, 4, and 6, for example, the individual electrodes Eda disposed facing each other on both side surfaces in the X axis direction in the dummy channels C1d and C2d also extend up to the end of the actuator plate 412 in the Y axis direction.

In addition, as described in detail later, the machining slits SL shown in fig. 6 are respectively formed in the Y-axis direction so as to isolate the individual electrodes Eda and the common electrode Edc on the surface of the actuator plate 412 from each other, for example, as follows. That is, the processing slits SL are formed by, for example, predetermined laser processing when the actuator plate 412 is formed. The individual electrode Eda and the common electrode Edc include an individual electrode pad Pda and a common electrode pad Pdc, respectively, which are pad portions electrically connected to these electrodes and to the flexible printed board (see fig. 6). Further, a groove D (see fig. 6) for separating the common electrode pad Pdc from the individual electrode pad Pda is formed by cutting with a cutter after the predetermined laser processing.

(cover 413)

As shown in fig. 3 to 5, the cover 413 is arranged to close the passages C1 and C2 (passage rows 421 and 422) of the actuator plate 412. Specifically, the cover plate 413 is bonded to the upper surface of the actuator plate 412, being of a plate-like configuration.

As shown in fig. 3 to 5, the cover 413 is formed with a pair of inlet-side common flow paths Rin1 and Rin2 and a pair of outlet-side common flow paths Rout1 and Rout2, and wall portions W1 and W2, respectively.

The wall portion W1 is disposed so as to cover the discharge channel C1e and the dummy channel C1d, and the wall portion W2 is disposed so as to cover the discharge channel C2e and the dummy channel C2d (see fig. 3 and 4).

The inlet-side common flow paths Rin1 and Rin2 and the outlet-side common flow paths Rout1 and Rout2 extend in the X-axis direction, as shown in fig. 5, for example, and are arranged in parallel with each other at predetermined intervals in the X-axis direction. The inlet-side common flow path Rin1 and the outlet-side common flow path Rout1 are formed in regions corresponding to the channel row 421 (the plurality of channels C1) of the actuator plate 412 (see fig. 3 to 5). On the other hand, the inlet-side common flow path Rin2 and the outlet-side common flow path Rout2 are formed in regions corresponding to the passage row 422 (the plurality of passages C2) of the actuator plate 412 (see fig. 3 and 4).

Note that each of the inlet-side common flow paths Rin1 and Rin2 corresponds to one specific example of the "first common flow path" in the present disclosure. In addition, the outlet-side common flow paths Rout1, Rout2 correspond to one specific example of the "second common flow path" in the present disclosure, respectively.

The inlet-side common flow path Rin1 is formed as a concave groove portion in the vicinity of the inner end of each channel C1 in the Y-axis direction (see fig. 3 to 5). In the inlet-side common flow path Rin1, a first supply slit Sin1 (see fig. 3 and 5) for penetrating the cover 413 in the thickness direction (Z-axis direction) is formed in a region corresponding to each discharge passage C1 e. Similarly, the inlet-side common flow path Rin2 is formed as a concave groove portion in the vicinity of the inner end of each channel C2 in the Y-axis direction (see fig. 3 and 4). In the inlet-side common flow path Rin2, second supply slits (not shown) that penetrate the cover 413 in the thickness direction are also formed in regions corresponding to the discharge passages C2 e.

The first supply slit Sin1 and the second supply slit correspond to one specific example of the "first through hole" of the present disclosure.

The outlet-side common flow path Rout1 is formed as a concave groove portion in the vicinity of the outer end portion of each channel C1 in the Y-axis direction (see fig. 3 to 5). In the outlet-side common flow path Rout1, a first discharge slit Sout1 (see fig. 3 to 5) for penetrating the cap 413 in the thickness direction is formed in a region corresponding to each discharge channel C1 e. Similarly, the outlet-side common flow path Rout2 is formed as a concave groove portion in the vicinity of the outer end portion of each channel C2 in the Y-axis direction (see fig. 3 and 4). In the outlet-side common flow path Rout2, second discharge slits (not shown) that penetrate the cover 413 in the thickness direction are also formed in regions corresponding to the discharge channels C2 e.

Note that each of the first discharge slit Sout1 and the second discharge slit corresponds to one specific example of the "second through-hole" of the present disclosure.

Here, as shown in fig. 5, for example, the first supply slit Sin1 and the first discharge slit Sout1 of each of the discharge channels C1e form a first slit pair Sp 1. In the first slit pair Sp1, the first supply slit Sin1 and the first discharge slit Sout1 are arranged in parallel along the extending direction (Y-axis direction) of the discharge channel C1 e. Similarly, a second slit pair (not shown) is formed by the second supply slit and the second discharge slit of each discharge passage C2 e. In the second slit pair, the second supply slit and the second discharge slit are arranged in parallel along the extending direction (Y-axis direction) of the discharge path C2 e.

In addition, such a first slit pair Sp1 and a second slit pair correspond to one embodiment of the "through hole pair" of the present disclosure, respectively.

In this way, the inlet-side common flow path Rin1 and the outlet-side common flow path Rout1 communicate with the discharge channels C1e via the first supply slit Sin1 and the first discharge slit Sout1, respectively (see fig. 3 to 5). That is, the inlet-side common flow path Rin1 is a common flow path communicating with each of the first supply slits Sin1 of each of the first slit pairs Sp1 described above, and the outlet-side common flow path Rout1 is a common flow path communicating with each of the first discharge slits Sout1 of each of the first slit pairs Sp1 (see fig. 5). The first supply slit Sin1 and the first discharge slit Sout1 are through holes through which the ink 9 flows between the discharge channel C1e and the supply slit Sin1, respectively. Specifically, as shown by the broken line arrows in fig. 3 and 4, the first supply slit Sin1 is a through-hole for allowing the ink 9 to flow into the discharge channel C1e, and the first discharge slit Sout1 is a through-hole for allowing the ink 9 to flow out of the discharge channel C1 e. On the other hand, neither the inlet-side common flow path Rin1 nor the outlet-side common flow path Rout1 communicates with each dummy channel C1 d. Specifically, the dummy channels C1d are closed by the bottoms of the inlet-side common flow path Rin1 and the outlet-side common flow path Rout 1.

Similarly, the inlet-side common flow path Rin2 and the outlet-side common flow path Rout2 communicate with the discharge passages C2e through the second supply slit and the second discharge slit, respectively. That is, the inlet-side common flow path Rin2 is a common flow path communicating with each of the second supply slits of each of the above-described second slit pairs, and the outlet-side common flow path Rout2 is a common flow path communicating with each of the second discharge slits of each of the second slit pairs. The second supply slit and the second discharge slit are through-holes through which the ink 9 flows between the discharge channel C2e and the supply slit. Specifically, the second supply slit is a through-hole for allowing the ink 9 to flow into the discharge channel C2e, and the second discharge slit is a through-hole for allowing the ink 9 to flow out of the discharge channel C2 e. On the other hand, neither the inlet-side common flow path Rin2 nor the outlet-side common flow path Rout2 communicates with each dummy passage C2d (see fig. 3 and 4). Specifically, the dummy channels C2d are closed by the bottoms of the inlet-side common flow path Rin2 and the outlet-side common flow path Rout 2.

[ detailed structures of the discharge channels C1e and C2e in the vicinity thereof ]

Further, the detailed structure of the nozzle holes H1 and H2 and the cap plate 413 in the vicinity of the discharge channels C1e and C2e will be described with reference to fig. 2 to 5.

First, in the head chip 41 of the present embodiment, as described above, the plurality of nozzle holes H1 include two kinds of nozzle holes H11 and H12, and the plurality of nozzle holes H2 also include two kinds of nozzle holes H21 and H22 (see fig. 2).

Here, the center position Pn11 of each nozzle hole H11 is offset toward the positive side in the Y axis direction (the side of the first supply slit Sin 1) with respect to the center position Pc1 of the discharge channel C1e in the extending direction (Y axis direction) (i.e., the center position of the wall portion W1 in the Y axis direction) (see fig. 3 and 5). Similarly, the center position of each nozzle hole H21 is offset toward the negative side (second supply slit side) in the Y-axis direction with respect to the center position of the discharge channel C2e in the extending direction (Y-axis direction) (i.e., the center position of the wall portion W2 in the Y-axis direction) (see fig. 2).

On the other hand, the center position Pn12 of each nozzle hole H12 is offset toward the negative side in the Y axis direction (the side of the first discharge slit Sout 1) with respect to the center position Pc1 of the discharge channel C1e in the extending direction (see fig. 4 and 5). Similarly, the center position of each nozzle hole H22 is offset toward the positive side (second discharge slit side) in the Y-axis direction with respect to the center position of the discharge channel C2e in the extending direction (Y-axis direction) (see fig. 2).

Therefore, in the discharge channel C1e (C1e1) communicating with each nozzle hole H11, the cross-sectional area of the flow path of the ink 9 in the portion communicating with the first supply slit Sin1 (first inlet side flow path cross-sectional area Sfin1) is smaller than the cross-sectional area of the flow path of the ink 9 in the portion communicating with the first discharge slit Sout1 (first outlet side flow path cross-sectional area Sfout1) (Sfin1 < Sfout 1: refer to FIG. 3). Similarly, in the discharge channel C2e communicating with each nozzle hole H21, the cross-sectional area of the flow path of the ink 9 in the portion communicating with the second supply slit (second inlet side flow path cross-sectional area) is smaller than the cross-sectional area of the flow path of the ink 9 in the portion communicating with the second discharge slit (second outlet side flow path cross-sectional area) (Sfin2 < Sfout 2).

On the other hand, in the discharge channel C1e (C1e2) communicating with each nozzle hole H12, the first outlet-side flow path cross-sectional area Sfout1 is smaller than the first inlet-side flow path cross-sectional area Sfin1 (Sfout1 < Sfin 1: refer to FIG. 4). Similarly, in the discharge channel C2e communicating with each nozzle hole H22, the second outlet-side cross-sectional area Sfout2 is smaller than the second inlet-side cross-sectional area Sfin2 (Sfout2 < Sfin 2).

In the head chip 41, the length (first pump length Lw 1: see fig. 3 and 4) of the discharge channel C1e in the extending direction (Y axis direction) corresponding to the distance between the first supply slit Sin1 and the first discharge slit Sout1 of the first slit pair Sp1 is the same for all the first slit pairs Sp1 (see fig. 5). Similarly, the length (second pump length) of the discharge passage C2e in the extending direction (Y-axis direction) corresponding to the distance between the second supply slit and the second discharge slit in the second slit pair is the same for all the second slit pairs.

In the head chip 41, the length of the first supply slit Sin1 in the Y axis direction (first supply slit length Lin1) and the length of the first discharge slit Sout1 in the Y axis direction (first discharge slit length Lout1) are alternately reversed between the first slit pairs Sp1 adjacent to each other in the X axis direction (see fig. 5). That is, for example, in the case where the first slit pair Sp1 has a magnitude relationship of (Lin1 > Lout1), the first slit pair Sp1 positioned on the two adjacent sides of the first slit pair Sp1 has a magnitude relationship of (Lin1 < Lout1) in reverse. For example, in the case where the first slit pair Sp1 has a magnitude relationship of (Lin1 < Lout1), the first slit pair Sp1 positioned on the two adjacent sides of the first slit pair Sp1 has a magnitude relationship of (Lin1 > Lout1) in reverse.

Similarly, the magnitude relationship between the Y-axis direction length of the second supply slit (second supply slit length) and the Y-axis direction length of the second discharge slit (second discharge slit length) is also alternately changed between the pairs of second slits adjacent in the X-axis direction as described above.

In the head chip 41, the length of the inlet-side common flow path Rin1 in the Y axis direction (first inlet-side flow path width Win1) is constant along the extending direction (X axis direction) of the inlet-side common flow path Rin1 (see fig. 5). The length of the outlet-side common flow path Rout1 in the Y-axis direction (first outlet-side flow path width Wout1) is also constant along the extending direction (X-axis direction) of the outlet-side common flow path Rout1 (see fig. 5).

Similarly, the length of the inlet-side common flow path Rin2 in the Y-axis direction (second inlet-side flow path width 1) is also constant along the extending direction (X-axis direction) of the inlet-side common flow path Rin 2. The length of the outlet-side common flow path Rout2 in the Y-axis direction (second outlet-side flow path width) is also constant along the extending direction (X-axis direction) of the outlet-side common flow path Rout 2.

The first pump length Lw1 and the second pump length described above correspond to one specific example of "the length of the wall portion" in the present disclosure. The first supply slit length Lin1 and the second supply slit length each correspond to a specific example of "first opening length" in the present disclosure, and the first discharge slit length Lout1 and the second discharge slit length each correspond to a specific example of "second opening length" in the present disclosure. The first inlet-side flow channel width Win1 and the second inlet-side flow channel width correspond to a specific example of the "first flow channel width" in the present disclosure, and the first outlet-side flow channel width Wout1 and the second outlet-side flow channel width correspond to a specific example of the "second flow channel width" in the present disclosure.

[ actions and effects ]

(A. basic operation of Printer 1)

In the printer 1, a recording operation (printing operation) of an image, characters, and the like on the recording paper P is performed as follows. In addition, as an initial state, the inks 9 of the respective corresponding colors (four colors) are sufficiently sealed in the four ink tanks 3(3Y, 3M, 3C, 3K) shown in fig. 1. The ink 9 in the ink tank 3 is filled into the ink jet head 4 through the circulation flow path 50.

When the printer 1 is operated in such an initial state, the raster rollers 21 of the transport mechanisms 2a and 2b are rotated, respectively, and the recording paper P is transported in the transport direction d (X-axis direction) between the raster rollers 21 and the pinch rollers 22. Simultaneously with this conveyance operation, the drive motor 633 of the drive mechanism 63 rotates the pulleys 631a and 631b, respectively, thereby operating the endless belt 632. Thereby, the carriage 62 reciprocates along the width direction (Y-axis direction) of the recording paper P while being guided by the guide rails 61a, 61 b. At this time, the four-color ink 9 is appropriately discharged onto the recording paper P by the inkjet heads 4(4Y, 4M, 4C, 4K), and the recording operation of the image, characters, and the like on the recording paper P is performed.

(B details of the operation of the ink-jet head 4)

Next, the detailed operation of the ink jet head 4 (the ejection operation of the ink 9) will be described. That is, in the ink jet head 4 (side-shooter type), the ejection operation using the ink 9 in the shear (shear) mode is performed as follows.

First, when the reciprocation of the carriage 62 (see fig. 1) is started, the drive circuit on the circuit board applies a drive voltage to the drive electrodes Ed (the common electrode Edc and the individual electrode Eda) in the ink jet head 4 via the flexible printed circuit board. Specifically, the drive circuit applies a drive voltage to each of the drive electrodes Ed disposed on a pair of drive walls Wd that demarcate the discharge channels C1e and C2 e. Thereby, the pair of driving walls Wd are deformed so as to protrude toward the dummy channels C1d and C2d adjacent to the discharge channels C1e and C2e, respectively.

Here, since the actuator plate 412 is of the chevron type as described above, the drive wall Wd is bent and deformed in a V shape around the middle position in the depth direction of the drive wall Wd by the drive voltage applied by the drive circuit described above. By the bending deformation of the driving wall Wd, the discharge passages C1e and C2e are deformed to bulge as if they were.

Incidentally, in the case where the structure of the actuator plate 412 is not of such a chevron type, but of the aforementioned cantilever type, the drive wall Wd is bent into a V-shape as follows. That is, in the case of the cantilever type, the driving electrode Ed is fitted up to the upper half portion in the depth direction by oblique vapor deposition, and thus the driving force reaches only the portion where the driving electrode Ed is formed, and the driving wall Wd (at the end portion in the depth direction of the driving electrode Ed) is bent and deformed. As a result, in this case, the drive wall Wd is also deformed in a V shape by bending, and hence the discharge passages C1e and C2e are deformed so as to bulge.

Thus, the volumes of the discharge channels C1e, C2e increase due to bending deformation based on the piezoelectric thickness shear effect at the pair of drive walls Wd. Further, the volumes of the discharge paths C1e and C2e increase, and the ink 9 stored in the inlet-side common flow paths Rin1 and Rin2 is guided into the discharge paths C1e and C2 e.

Then, the ink 9 thus induced into the discharge channels C1e, C2e becomes a pressure wave and propagates into the discharge channels C1e, C2 e. Then, at the timing (or the timing in the vicinity thereof) when the pressure wave reaches the nozzle holes H1, H2 of the nozzle plate 411, the driving voltage applied to the driving electrode Ed becomes 0 (zero) V. As a result, the driving wall Wd is restored from the state of the bending deformation, and as a result, the temporarily increased volumes of the discharge passages C1e and C2e are restored to original volumes again.

In this way, in the process of returning the volumes of the discharge channels C1e, C2e to their original volumes, the pressures inside the discharge channels C1e, C2e increase, and the ink 9 inside the discharge channels C1e, C2e is pressurized. As a result, the droplet-shaped ink 9 is discharged to the outside (toward the recording paper P) through the nozzle holes H1 and H2 (see fig. 3 and 4). In this way, the ejection operation (discharge operation) of the ink 9 from the ink jet head 4 is performed, and as a result, the recording operation of the image, characters, and the like on the recording paper P is performed.

(C, circulation action of ink 9)

Next, the circulation operation of the ink 9 through the circulation flow path 50 will be described in detail with reference to fig. 1, 3, and 4.

In the printer 1, the ink 9 is fed from the ink tank 3 into the flow path 50a by the above-described liquid feeding pump. The ink 9 flowing through the flow path 50b is sent into the ink tank 3 by the liquid sending pump.

At this time, in the inkjet head 4, the ink 9 flowing from the inside of the ink tank 3 through the flow path 50a flows into the inlet-side common flow paths Rin1 and Rin 2. The ink 9 supplied to the inlet-side common flow paths Rin1 and Rin2 is supplied into the discharge channels C1e and C2e of the actuator plate 412 through the first supply slit Sin1 or the second supply slit (see fig. 3 and 4).

The ink 9 in the discharge channels C1e and C2e flows into the outlet-side common channels Rout1 and Rout2 through the first discharge slit Sout1 or the second discharge slit (see fig. 3 and 4). The ink 9 supplied to the outlet-side common flow paths Rout1 and Rout2 is discharged to the flow path 50b and flows out of the ink jet head 4. Then, the ink 9 discharged to the flow path 50b is returned to the ink tank 3. In this way, the circulation operation of the ink 9 through the circulation flow path 50 is performed.

Here, when an ink having high drying performance is used in the non-circulating type ink jet head, there is a risk that: the ink is locally highly viscous and solidified due to drying of the ink in the vicinity of the nozzle hole, and as a result, a failure occurs in which the ink is not discharged. On the other hand, in the ink jet head 4 (circulation type ink jet head) of the present embodiment, since the fresh ink 9 is always supplied to the vicinity of the nozzle holes H1 and H2, the failure that the ink is not discharged as described above is avoided.

(D. action and Effect)

Next, the operation and effect of the ink jet head 4 of the present embodiment will be described in detail in comparison with the comparative example.

(D-1. comparative example)

Fig. 7 schematically shows, in a bottom view (X-Y bottom view), a configuration example of a state in which the nozzle plate 101 according to the comparative example is removed (appearing later) in the inkjet head 104 according to the comparative example. Fig. 8 schematically shows an example of the cross-sectional configuration (an example of the Y-Z cross-sectional configuration) of the ink jet head 104 according to the comparative example, taken along the line VIII-VIII shown in fig. 7.

As shown in fig. 7 and 8, the inkjet head 104 (head chip 100) of this comparative example corresponds to an example in which the arrangement structure of the nozzle holes H1, H2 is changed in the inkjet head 4 (head chip 41) of the present embodiment.

Specifically, in the nozzle plate 101 of this comparative example, unlike the nozzle plate 411 of the present embodiment, the nozzle holes H1, H2 in the nozzle rows An101, 102 are arranged in a row along the extending direction (X-axis direction) of the nozzle rows An101, 102, respectively (see fig. 7). That is, unlike the case of the present embodiment described above, in this comparative example, the center position Pn1 of each nozzle hole H1 coincides with the center position Pc1 of the discharge channel C1e along the extending direction (Y axis direction) (i.e., the center position of the wall portion W1 along the Y axis direction) (see fig. 8). Similarly, in this comparative example, the center position of each nozzle hole H2 coincides with the center position of the discharge channel C2e along the extending direction (Y-axis direction) (i.e., the center position of the wall portion W2 along the Y-axis direction).

In such a comparative example, since the nozzle holes H1 and H2 are arranged in a row in the X axis direction as described above, for example, when the distance between the adjacent nozzle holes H1 and the distance between the adjacent nozzle holes H2 become smaller with an increase in resolution of a printed pixel, for example, there is a risk as follows. That is, in this case, the distance between the droplets ejected in the same period and flying toward the recording medium (recording paper P or the like) decreases, and thus there is a case where the droplets flying from the nozzle holes H1, H2 to the recording medium are locally concentrated. As a result, the influence (generation of air flow) on each flying droplet increases, and as a result, uneven density of the texture occurs on the recording medium, and the print image quality may deteriorate.

(D-2. this embodiment mode)

In contrast, in the inkjet head 4 (head chip 41) according to the present embodiment, among the plurality of nozzle holes H1, H2, the nozzle holes H1 adjacent to each other in the X-axis direction (and the nozzle holes H2 adjacent to each other in the X-axis direction) are arranged so as to be offset from each other along the extending direction (Y-axis direction) of the discharge channels C1e, C2 e.

Thus, in the present embodiment, the distance between the adjacent nozzle holes H1 (and the distance between the adjacent nozzle holes H2) is larger than that in the case where the nozzle holes H1 and H2 are arranged in a row in the X-axis direction (the above comparative example). Therefore, the distance between the droplets ejected in the same period and flying toward the recording medium (recording paper P or the like) increases, and thus it is possible to alleviate the local concentration of the droplets flying from the nozzle holes H1, H2 to the recording medium. As a result, in the present embodiment, the influence (generation of air flow) on each flying liquid droplet is suppressed, and as a result, the generation of the uneven density of the texture on the recording medium (recording paper P or the like) as described above is suppressed as compared with the comparative example. For the above reasons, the ink jet head 4 (head chip 41) of the present embodiment can improve the print image quality as compared with, for example, the ink jet head 104 (head chip 100) of the comparative example described above.

In particular, in the present embodiment, the entire plurality of discharge passages C1e (the entire plurality of discharge passages C2e) are arranged in a row in the X axis direction in the actuator plate 412, and therefore, the following is provided. That is, the existing structure is maintained in the entirety of the plurality of discharge passages C1e (the entirety of the plurality of discharge passages C2 e). Therefore, the print image quality can be improved while maintaining (without increasing) the size of the entire head chip 41 (chip size).

Further, in the present embodiment, as described above, in the structure in which the entire plurality of discharge channels C1e (and the entire plurality of discharge channels C2e) are arranged with the nozzle holes H1 adjacent to each other in the X-axis direction (and the nozzle holes H2 adjacent to each other) offset from each other in the Y-axis direction, the following can be made as in the conventional structure. That is, the first pump length Lw1 and the second pump length can be made the same (common) in all the first slit pairs Sp1 and all the second slit pairs, respectively. Thus, in the present embodiment, variation in discharge characteristics between the adjacent nozzle holes H1 (and between the adjacent nozzle holes H2) is suppressed, and as a result, the print image quality can be further improved. In this embodiment, the following is compared with the case of modification 2 (the case where the first and second supply slits Sin1 and Sout1 and the second discharge slits are arranged alternately in the X-axis direction: see fig. 12 described later). That is, in the case of modification 2, the entire plurality of discharge passages C1e (and the entire plurality of discharge passages C2e) are also arranged in a staggered manner in the X-axis direction (see fig. 12). On the other hand, in the present embodiment, as in the conventional structure, since the entire plurality of discharge channels C1e (the entire plurality of discharge channels C2e) can be formed (processed) without being staggered (see fig. 5), the workability of the head chip 41 is good (the head chip can be processed while maintaining the conventional manufacturing process). Thus, in the present embodiment, the manufacturing process of the head chip 41 can be simplified.

In the present embodiment, the channel widths (the first inlet side channel width Win1 and the second inlet side channel width) of the inlet side common channels Rin1 and Rin2 and the channel widths (the first outlet side channel width Wout1 and the second outlet side channel width) of the outlet side common channels Rout1 and Rout2 are constant along the extending direction (the X-axis direction) of the common channels, respectively, and therefore, the following is provided. That is, the structures of the inlet-side common flow paths Rin1 and Rin2 and the outlet-side common flow paths Rout1 and Rout2 can be maintained as conventional structures.

In the present embodiment, one side of each of the dummy channels C1d and C2d along the extending direction (Y-axis direction) is the side surface described above, and the other side along the extending direction is open to the end of the actuator plate 412 along the Y-axis direction, and therefore, the following is provided. That is, as described above, in the configuration in which the nozzle holes H1 adjacent in the X-axis direction are arranged offset from each other (and the nozzle holes H2 adjacent to each other) in the Y-axis direction, high-density arrangement of the nozzle holes H1, H2 in the nozzle plate 411 can be achieved without changing the size (chip size) of the entire head chip 41. Further, since the other side of each of the dummy channels C1d and C2d is open up to the end, the individual electrode Eda individually disposed in each of the dummy channels C1d and C2d can be formed separately (in an electrically insulated state) from the common electrode Edc disposed in each of the discharge channels C1e and C2e (see fig. 6). For these reasons, in the present embodiment, the chip size of the head chip 41 can be reduced, and the manufacturing process of the head chip 41 can be simplified.

<2. modification >

Next, modifications (modifications 1 and 2) of the above embodiment will be described. Note that the same reference numerals are given to the same components as those in the embodiment, and the description thereof is omitted as appropriate.

[ modification 1]

(Structure)

Fig. 9 schematically shows an example of a top-view configuration (an X-Y top-view configuration example) of the top surface side of the cap 413a according to modification 1 in the inkjet head 4a according to modification 1. Fig. 10 and 11 schematically show a cross-sectional configuration example (a cross-sectional Y-Z configuration example) of the ink jet head 4a according to modification 1. Specifically, fig. 10 is a sectional configuration example corresponding to fig. 3 in the embodiment, and fig. 11 is a sectional configuration example corresponding to fig. 4 in the embodiment.

As shown in fig. 10 and 11, the inkjet head 4a of modification 1 corresponds to an example in which the head chip 41a is provided in place of the head chip 41 in the inkjet head 4 (see fig. 3 and 4) of the embodiment. The head chip 41a of modification 1 corresponds to an example in which a cap 413a described below is provided in place of the cap 413 on the head chip 41, and the other configurations are basically the same (see fig. 10 and 11). Further, such an ink-jet head 4a corresponds to one specific example of the "liquid-jet head" in the present disclosure.

For example, as shown in fig. 9, in the cover 413a of modification example 1, unlike the cover 413 (see fig. 5) of the embodiment, the flow path widths (the first inlet side flow path width Win1 and the second inlet side flow path width) of the inlet side common flow paths Rin1 and Rin2 are changed for each of the first slit pair Sp1 and the second slit pair along the X-axis direction. Specifically, the first inlet-side flow channel width Win1 and the second inlet-side flow channel width respectively vary in the X-axis direction in accordance with the alternating variation of the first supply slit length Lin1 and the second supply slit length (the variation in the size of each of the first slit pair Sp1 and the second slit pair) among the first slit pair Sp1 (and the adjacent second slit pair) adjacent to each other in the X-axis direction (see fig. 9).

Similarly, in the cover 413a, the flow path widths (the first outlet side flow path width Wout1 and the second outlet side flow path width) of the outlet-side common flow paths Rout1 and Rout2 are changed for each of the first slit pair Sp1 and the second slit pair along the X-axis direction (see fig. 9). Specifically, the first outlet-side flow channel width Wout1 and the second outlet-side flow channel width respectively vary in the X-axis direction in accordance with the alternating variation of the first discharge slit length Lout1 and the second discharge slit length (the variation in the size of each of the first slit pair Sp1 and the second slit pair) in the first slit pair Sp1 (and the adjacent second slit pair) adjacent to each other in the X-axis direction (see fig. 9).

With such a configuration, for example, as indicated by the broken line arrows in fig. 10 and 11, in the cover 413a, the thickness of one side surface portion of the wall portions W1 and W2 is larger than that of the cover 413 (see fig. 3 and 4) of the embodiment. Specifically, for example, as shown in fig. 10, in the vicinity of the ejection channels C1e and C2e communicating with the nozzle holes H11 and H21, the thickness of the side surface portions on the first supply slit Sin1 and the second supply slit side in the wall portions W1 and W2 is larger than that in the embodiment (see fig. 3). On the other hand, as shown in fig. 11, for example, in the vicinity of the discharge channels C1e and C2e communicating with the nozzle holes H12 and H22, the thickness of the side surface portions on the first discharge slit Sout1 and the second discharge slit side in the wall portions W1 and W2 is larger than that in the embodiment (see fig. 4).

(action and Effect)

The same effects can be obtained by the same operation as that of the ink jet head 4 (head chip 41) of the embodiment also in the ink jet head 4a (head chip 41a) of modification 1 having such a configuration.

In particular, in modification 1, as described above, the first inlet-side flow path width Win1 and the second inlet-side flow path width change in the X-axis direction in accordance with the alternating change in the first supply slit length Lin1 and the second supply slit length, respectively, and the first outlet-side flow path width Wout1 and the second outlet-side flow path width change in the X-axis direction in accordance with the alternating change in the first discharge slit length Lout1 and the second discharge slit length, respectively. Thus, in modification 1, the first inlet side channel width Win1 and the second inlet side channel width and the first outlet side channel width Wout1 and the second outlet side channel width are fixed in the X axis direction as follows, for example, as in the embodiment (see fig. 5). That is, the occurrence of the thinned portion (the side surface portion on the one side of the wall portions W1 and W2 described above) in the cover 413a is suppressed to the minimum as the inlet-side common flow paths Rin1 and Rin2 and the outlet-side common flow paths Rout1 and Rout2 are formed. As a result, in modification 1, compared with the case of the embodiment (see the cover 413 shown in fig. 3 and 4), the inlet-side common flow paths Rin1 and Rin2 and the outlet-side common flow paths Rout1 and Rout2 have improved mechanical strength, and the occurrence of cracks can be suppressed. Therefore, in modification 1, the reliability of the head chip 41a can be improved as compared with the above embodiment.

[ modification 2]

(Structure)

Fig. 12 schematically shows an example of a top-view configuration (an X-Y top-view configuration example) of the top surface side of the cap 413b according to modification 2 in the inkjet head 4b according to modification 2.

As shown in fig. 12, the inkjet head 4b of modification 2 corresponds to an example in which a head chip 41b is provided in place of the head chip 41 in the inkjet head 4 (see fig. 3 and 4) of the embodiment. The head chip 41b of modification 2 corresponds to an example in which an actuator plate 412b and a cover plate 413b described below are provided in the head chip 41 instead of the actuator plate 412 and the cover plate 413, respectively, and the other configurations are basically the same (see fig. 12). Further, such an ink-jet head 4b corresponds to one specific example of the "liquid-jet head" in the present disclosure.

For example, as shown in fig. 12, in the actuator plate 412b of modification 2, unlike the actuator plate 412 of embodiment and modification 1 (see fig. 5 and 9), the discharge passages C1e and C2e are arranged as follows. That is, in the actuator plate 412b, unlike the actuator plate 412, a part (not the whole) of the plurality of discharge passages C1e, C2e is arranged so as to overlap each other in the X-axis direction. Thus, in the actuator plate 421b, the entire plurality of discharge passages C1e (the entire plurality of discharge passages C2e) are arranged in a staggered manner in the X-axis direction (arranged so as to be alternately offset in the Y-axis direction) (see fig. 12).

In the cover 413b of modification 2, the first pump length Lw1 and the second pump length are the same for all the first slit pair Sp1 and the second slit pair (see fig. 12), as in the covers 413 and 413a of embodiment 1 (see fig. 5 and 9).

On the other hand, in the cover 413b, unlike the covers 413 and 413a, the first supply slit length Lin1 and the second supply slit length are the same as the first discharge slit length Lout1 and the second discharge slit length (Lin1 is Lout1, and the second supply slit length is the second discharge slit length). In the cover 413b, unlike the covers 413 and 413a, the first supply slit Sin1 and the second supply slit and the first discharge slit Sout1 and the second discharge slit are arranged alternately in the extending direction (X-axis direction) of the inlet-side common flow paths Rin1 and Rin2 and the outlet-side common flow paths Rout1 and Rout2, respectively (see fig. 12).

(action and Effect)

In the ink jet head 4b (head chip 41b) of modification 2 having such a configuration, the same effects can be obtained basically by the same operation as the ink jet head 4 (head chip 41) of the embodiment.

In particular, in modification 2, as described above, the nozzle holes H1 adjacent to each other in the X-axis direction (the adjacent nozzle holes H2) are arranged offset from each other in the Y-axis direction, and the entire plurality of discharge channels C1e (the entire plurality of discharge channels C2e) are also arranged in a staggered manner in the X-axis direction, and hence the following is provided. That is, as compared with the case where the entire plurality of discharge channels C1e (the entire plurality of discharge channels C2e) are arranged in a line in the X-axis direction as in embodiment and modification 1, for example, the relative positional deviation along the extending direction (Y-axis direction) of the discharge channels C1e and C2e between the nozzle holes H1 and H2 corresponding to the discharge channels C1e and C2e is reduced. That is, if the example of the discharge channel C1e (C1e1, C1e2) shown in fig. 12 is used for description, the Y-axis direction position of the nozzle hole H11 with respect to the discharge channel C1e1 and the Y-axis direction position of the nozzle hole H12 with respect to the discharge channel C1e2 are less likely to be displaced between the discharge channels C1e adjacent in the X-axis direction. In other words, the nozzle holes H1(H11, H12) can be positioned near the center of the discharge channel C1e (C1e1, C1e2) in the extending direction (Y axis direction), and the discharge characteristics at the nozzle holes H1 can be approximated. The same applies to the discharge channel C2e and the nozzle hole H2. Thus, in modification 2, as compared with the case of the embodiment and modification 1, for example, variations in the discharge characteristics between the nozzle holes H1 adjacent to each other in the X-axis direction (and between the adjacent nozzle holes H2) are suppressed, and as a result, the print image quality can be further improved.

In modification 2, since the first and second supply slit lengths Lin1 and Lout1 and the second discharge slit length are the same as described above, for example, the following is compared with the case of embodiment and modification 1. That is, in the case of the embodiment and the modification 1 (see fig. 5 and 9), as described above, the first and second supply slit lengths Lin1 and Lout1 and the second discharge slit length have a magnitude relationship between them that is alternately exchanged between the first and second slit pairs Sp1 and Sp1 adjacent to each other in the X-axis direction. On the other hand, in modification 2, since the first supply slit length Lin1 and the second supply slit length are equal to the first discharge slit length Lout1 and the second discharge slit length, a pressure difference between the nozzle holes H1 adjacent to each other in the X-axis direction (between the adjacent nozzle holes H2) is less likely to occur, and the nonuniformity of the discharge speed of the ink 9 is reduced. As a result, in modification 2, the print image quality can be further improved.

<3 > another modification

The present disclosure has been described above by way of the embodiments and the modifications, but the present disclosure is not limited to these embodiments and the like, and various modifications are possible.

For example, although the above embodiments and the like have been described with specific reference to examples of the configuration (shape, arrangement, number, and the like) of each member in the printer and the inkjet head, the present invention is not limited to the examples described in the above embodiments and the like, and other shapes, arrangements, numbers, and the like may be used. The values, ranges, size relationships, and the like of the various parameters described in the above embodiments and the like are not limited to the examples described in the above embodiments and the like, and other values, ranges, size relationships, and the like may be used.

Specifically, for example, in the above-described embodiment and the like, the description has been made by taking the inkjet head 4 of two-row type (having two nozzle rows An1, An2), but the present embodiment is not limited thereto. That is, for example, a one-line type (having one nozzle line) ink jet head, and a multi-line type (having three or more nozzle lines) ink jet head of three or more lines (for example, three or more lines, four or more lines) may be used.

In the above-described embodiments, the example of the offset arrangement (staggered arrangement) of the nozzle holes H1(H11, H12), H2(H21, H22), the example of the structure of the cover plate (structure of the supply slit, the discharge slit, the inlet-side common flow path, the outlet-side common flow path, and the like) and the like are specifically described, but the present invention is not limited to these examples. That is, the offset arrangement of the nozzle holes and the structure of the cover plate may be other structural examples.

In the above-described embodiments and the like, the case where each discharge channel (discharge groove) and each dummy channel (non-discharge groove) extend in the Y-axis direction (direction orthogonal to the direction in which the channels are arranged in parallel) in the actuator plate 412 has been described as an example, but the present invention is not limited to this example. That is, for example, each of the discharge channels and each of the dummy channels may extend in an oblique direction (a direction forming an angle with each of the X-axis direction and the Y-axis direction) in the actuator plate 412.

Further, for example, the cross-sectional shapes of the nozzle holes H1 and H2 are not limited to the circular shapes described in the above embodiments and the like, and may be polygonal shapes such as an elliptical shape and a triangular shape, and star shapes. In addition, the cross-sectional shapes of the discharge channels C1e and C2e and the dummy channels C1d and C2d are also described by taking as an example the case where the channels are formed by cutting with a cutter so as to have an arc-shaped (curved) side surface in the above-described embodiment and the like, but the present invention is not limited to this example. That is, for example, the discharge channels C1e and C2e and the dummy channels C1d and C2d may be formed by a processing method (etching, sandblasting, or the like) other than the cutting processing by the cutter so that the cross-sectional shapes thereof are various side shapes other than the circular arc shape.

In the above-described embodiments and the like, the description has been given by taking as an example a circulation type inkjet head that circulates and uses the ink 9 between the ink tank and the inkjet head, but the present embodiment is not limited thereto. That is, the present disclosure may be applied to an ink jet head of a non-circulation type that is used without circulating the ink 9, depending on the situation.

In addition, various types of structures can be applied to the structure of the inkjet head. That is, for example, in the above-described embodiments, a so-called side-shooter type ink jet head that ejects the ink 9 from the center portion in the extending direction of each ejection channel in the actuator plate is taken as an example. However, the present disclosure is not limited to this example, and may be applied to other types of inkjet heads.

Further, the printer is not limited to the printer described in the above embodiments, and various types such as a MEMS (Micro Electro Mechanical Systems) type printer can be applied.

The series of processing described in the above embodiments and the like may be performed by hardware (circuit) or may be performed by software (program). In the case of software, the software is constituted by a program group for executing each function by a computer. The programs may be, for example, pre-programmed into the computer and used, or may be installed in the computer from a network or a recording medium and used.

Further, in the above-described embodiments and the like, the printer 1 (ink jet printer) has been described as one specific example of the "liquid jet recording apparatus" of the present disclosure, but the present disclosure is not limited to this example, and may be applied to apparatuses other than the ink jet printer. In other words, the "liquid ejecting head" (ink jet head) of the present disclosure may be applied to other apparatuses than an ink jet printer. Specifically, for example, the "liquid ejection head" of the present disclosure can also be applied to a facsimile machine, an on-demand printer, or the like.

In addition, the various examples described above may be applied in any combination.

The effects described in the present specification are merely examples, are not limited, and other effects may be provided.

In addition, the present disclosure can also adopt the following configuration.

(1) A head chip for ejecting liquid, comprising: an actuator plate having a plurality of discharge grooves; and a nozzle plate having a plurality of nozzle holes individually communicating with the plurality of discharge grooves; the plurality of discharge grooves are arranged in parallel so that at least a part of the plurality of discharge grooves overlap each other in a predetermined direction, and nozzle holes adjacent to each other in the predetermined direction among the plurality of nozzle holes are arranged to be offset from each other in the extending direction of the discharge grooves in the nozzle plate.

(2) The head chip according to item (1) above, wherein the entire plurality of discharge grooves are arranged so as to overlap each other in the predetermined direction, and the entire plurality of discharge grooves are arranged in a row in the predetermined direction.

(3) The head chip according to item (2) above, further comprising a cover plate having: a first through hole for allowing the liquid to flow into the discharge groove, a second through hole for allowing the liquid to flow out from the discharge groove, and a wall portion covering the discharge groove, wherein the pair of through holes each formed by the first through hole and the second through hole of each discharge groove are arranged in parallel in the extending direction of the discharge groove, the length of the wall portion along the extending direction of the discharge groove corresponding to the distance between the first through-hole and the second through-hole in the pair of through-holes is the same for all the pairs of through-holes, in addition, the magnitude relationship between a first opening length that is a length of the first through hole in the extending direction of the discharge groove and a second opening length that is a length of the second through hole in the extending direction of the discharge groove is alternately changed between the pairs of through holes adjacent to each other in the predetermined direction.

(4) The head chip according to item (3) above, wherein the cover plate further includes: a first common flow path extending in the predetermined direction and communicating with each of the first through holes of each of the pair of through holes; and a second common flow path extending in the predetermined direction and communicating with each of the second through holes of each of the through hole pairs, wherein a first flow path width, which is a length of the first common flow path in a direction orthogonal to the predetermined direction, is constant in the predetermined direction, and a second flow path width, which is a length of the second common flow path in the direction orthogonal to the predetermined direction, is constant in the predetermined direction.

(5) The head chip according to item (3) above, wherein the cover plate further includes: a first common flow path extending in the predetermined direction and communicating with each of the first through holes of each of the pair of through holes; and a second common flow path extending in the predetermined direction and communicating with each of the second through holes of each of the pairs of through holes, a first flow path width being a length of the first common flow path in a direction orthogonal to the predetermined direction and varying in the predetermined direction in correspondence with an alternate variation in the first opening length of each of the pairs of through holes adjacent in the predetermined direction, and a second flow path width being a length of the second common flow path in the direction orthogonal to the predetermined direction and varying in the predetermined direction in correspondence with an alternate variation in the second opening length of each of the pairs of through holes adjacent in the predetermined direction.

(6) The head chip according to item (1) above, wherein a part of the plurality of ejection grooves are arranged so as to overlap each other in the predetermined direction, and the entirety of the plurality of ejection grooves is arranged so as to intersect each other in the predetermined direction.

(7) The head chip according to item (6) above, further comprising a cover plate having: a first through hole for allowing the liquid to flow into the discharge groove, a second through hole for allowing the liquid to flow out from the discharge groove, and a wall portion covering the discharge groove, wherein the pair of through holes each formed by the first through hole and the second through hole of each discharge groove are arranged in parallel in the extending direction of the discharge groove, the length of the wall portion along the extending direction of the discharge groove corresponding to the distance between the first through-hole and the second through-hole in the pair of through-holes is the same for all the pairs of through-holes, further, a first opening length of the first through hole along the extending direction of the discharge groove and a second opening length of the second through hole along the extending direction of the discharge groove are equal to each other, and the first through hole and the second through hole are arranged in a staggered manner in the predetermined direction.

(8) The head chip according to any one of the above (1) to (7), wherein the actuator plate further includes a plurality of non-ejection grooves arranged in parallel in the predetermined direction, the ejection grooves and the non-ejection grooves are alternately arranged in the predetermined direction, one side of the non-ejection grooves in the extending direction of the non-ejection grooves is a curved side surface in which a cross-sectional area of the non-ejection grooves gradually decreases toward the nozzle plate side, and the other side of the non-ejection grooves in the extending direction of the non-ejection grooves opens up to an end of the actuator plate in the extending direction of the non-ejection grooves.

(9) A liquid ejecting head comprising the head chip according to any one of (1) to (8) above.

(10) A liquid ejecting recording apparatus comprising the liquid ejecting head described in the above (9).

Description of the symbols

1 Printer

10 frame body

2a, 2b conveying mechanism

21 grid roller

22 pinch roll

3(3Y, 3M, 3C, 3K) ink tank

4(4Y, 4M, 4C, 4K), 4a, 4b ink jet head

41. 41a, 41b head chip

411 nozzle plate

412. 412b actuator plate

413. 413a, 413b cover plate

420 tail part

421. 422 channel row

50 circulation flow path

50a, 50b flow path (supply pipe)

6 scanning mechanism

61a, 61b guide rail

62 sliding rack

63 drive mechanism

631a, 631b pulley

632 endless belt

633 driving motor

9 ink

P recording paper

d direction of conveyance

H1, H11, H12, H2, H21, H22 nozzle orifices

Nozzle arrays of An1, An11, An12, An2, An21, An22

C1, C2 channel

C1e (C1e1, C1e2), C2e spitting channel

C1d, C2d dummy channel (non-spitting channel)

Wd driving wall

Ed drive electrode

Eda Individual electrode (active electrode)

Edc common electrode (common electrode)

Pda individual electrode pad

Pdc common electrode pad

D groove

Inlet side common flow path for Rin1 and Rin2

Outlet side common flow path of Rout1 and Rout2

Sin1 first supply slit

Sout1 first discharge slit

Sp1 first slit pair

W1, W2 wall part

Lw1 first pump length

Lin1 first feed slit length

Lout1 first discharge slit length

First inlet side flow channel Width of Win1

First outlet side flow channel Width of Wout1

First inlet side flow passage sectional area of Sfin1

First outlet side flow passage sectional area of Sfout1

Pc1, Pn11, Pn12 center position

SL machining slits.