JP2016055545A - Liquid spray head and liquid spray device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid spray head excellent in printing stability and a liquid spray device.SOLUTION: The liquid spray head comprises: an actuator plate having a channel row in which discharge channels are arrayed parallely in a X-direction; a cover plate which has an inlet-side common ink chamber collectively to be communicated with the discharge channels at one end part in a Y-direction and an outlet-side common ink chamber that is collectively communicated with the discharge channels at the other end part in the Y-direction and is laminated on the actuator plate; and a flow path member 54 that is laminated on the cover plate and is long in the X-direction. The flow-path member 54 has an inlet-side pressure buffering portion 93 that is communicated with the inside of the inlet-side common ink chamber and can be bent and deformed, and an outlet-side pressure buffering portion 99 that is communicated with the inside of the outlet-side common ink chamber and can be bent and deformed, where the respective pressure buffering portions 93 and 99 are arrayed parallely in the X-direction.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus.

2. Description of the Related Art Conventionally, an ink jet printer (liquid ejecting apparatus) provided with an ink jet head (liquid ejecting head) is an apparatus that ejects droplet-shaped ink onto recording paper (recording medium) and records images and characters on the recording paper. is there.
In general, an inkjet head includes a nozzle plate having a nozzle row composed of a plurality of nozzle holes, an actuator plate having a plurality of channels communicating with the nozzle holes, and a cover plate having a common ink chamber communicated collectively with each channel; It has. According to this configuration, the inside of the channel is contracted to increase the pressure in the channel, so that the ink in the channel is ejected from the nozzle holes, and the ink is adhered to the recording paper.

  However, in the above-described inkjet head, for example, pressure fluctuations in the channels that occur during ink ejection or the like propagate as pressure waves to the other channels or the like via the common ink chamber or the common ink chamber, and the ejection performance ( There is a problem that printing stability is affected. Specifically, the pressure wave generated when the channel is driven propagates to the common ink chamber and affects the ejection as a frequency component other than the resonance frequency of the pressure wave generated for ejection in the other channels, There are effects such as a decrease or increase in speed. At the same time, the droplet size also decreases or increases, which affects the image quality of the recording paper. Further, the pressure fluctuation described above increases as the discharge amount per unit time increases or the droplet size increases.

  Therefore, for example, in Patent Document 1 below, a nozzle hole is disposed at one end portion in the extending direction of the channel, and ink is supplied into the channel from a common ink chamber disposed at the other end portion in the extending direction. In the so-called edge shoot type head chip, a configuration is disclosed in which a thin pressure fluctuation buffer portion is formed in the common ink chamber in order to buffer the pressure fluctuation in the common ink chamber.

Japanese Patent Laid-Open No. 2005-14618

By the way, in the above-described inkjet head, in the so-called side shoot type inkjet head in which the nozzle hole is communicated with the intermediate portion in the channel extending direction, both ends of the channel in the extending direction communicate with the common ink chamber. Become.
However, in the configuration of Patent Document 1 described above, the pressure fluctuation buffer portion is disposed only at the other end of the channel. It is difficult to effectively suppress pressure fluctuations generated in

  In this case, the pressure balance (ratio of pressure loss) between the one end side and the other end side with respect to the nozzle hole becomes uneven, and it is difficult to maintain the inside of the liquid jet head at a desired pressure. Therefore, for example, it is difficult to stably hold the meniscus in the nozzle hole, and there is a possibility that the printing stability is lowered.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid ejecting head and a liquid ejecting apparatus having excellent printing stability.

The present invention provides the following means in order to solve the above problems.
The liquid ejecting head according to the aspect of the invention includes an actuator plate having a channel row in which channels extending along the first direction are arranged in parallel in a second direction orthogonal to the first direction, and one end of the first direction in the plurality of channels. A cover plate stacked on the actuator plate, the first common liquid chamber communicated collectively at a portion, and the second common liquid chamber communicated collectively at the other end in the first direction to the plurality of channels; A flow path member that is stacked on the cover plate and that is long in the second direction, and the flow path member communicates with the first common liquid chamber and is deformable and deformable. A second pressure buffering portion that communicates with the second common liquid chamber and that can be deformed flexibly, and the first pressure buffering portion and the second pressure buffering portion are arranged side by side in the second direction. ing And wherein the door.

According to this configuration, the pressure fluctuation can be buffered by the pressure buffer portion being bent and deformed according to the pressure fluctuation generated in the liquid ejecting head or the like. In this case, since the pressure buffer portion communicates with each common liquid chamber, the pressure fluctuation in the liquid ejecting head can be effectively buffered.
And since the 1st pressure buffer part and the 2nd pressure buffer part are arranged along with the 2nd direction, compared with the case where a pressure buffer part is arranged along with the 1st direction temporarily, in each pressure buffer part The width in the first direction can be ensured. Thereby, it becomes easy to bend and deform a pressure buffer part, and it becomes possible to raise a pressure buffer effect more. As a result, the pressure balance (ratio of pressure loss) on the first pressure buffer portion side and the second pressure buffer portion side with respect to the channel can be uniformly maintained, and the inside of the liquid ejecting head is maintained at a desired pressure. It becomes easy. In this case, the pressure center in the liquid ejecting head can be set in the vicinity of the ejection hole communicating with the central portion in the first direction of the channel, so that the meniscus can be stably held and the liquid can be ejected stably. Can do.

The first pressure buffering portion communicates with the central portion in the second direction in the first common liquid chamber through the first communication passage, and the second pressure buffering portion communicates with the second common liquid through the second communication passage. You may communicate in the center part of the 2nd direction in a chamber.
According to this configuration, since the first communication path and the second communication path communicate with each other at the central portion in the second direction in each common liquid chamber, for example, each communication path has each common liquid chamber on one side in the second direction. Compared to the configuration communicating with the channel, the distance in the second direction between the channel farthest from each communication path and the communication path among the channels can be shortened (halved). Thereby, the pressure difference between all the channels can be reduced (halved).

The first communication path and the second communication path may have the same opening area.
According to this configuration, the difference in pressure loss when passing through the communication path can be reduced, and the liquid can be circulated smoothly in the flow path member.

Further, the first pressure buffer portion and the second pressure buffer portion may have the same volume.
According to this structure, since the volume in each pressure buffer part is equivalent, both pressure buffer effects can be made equivalent. As a result, the pressure balance on the first pressure buffer side and the second pressure buffer side can be more evenly maintained with respect to the channel.

In addition, liquid may flow into the channel through the first pressure buffer and the first common liquid chamber, and liquid may be discharged through the second common liquid chamber and the second pressure buffer.
According to this configuration, the positive pressure on the upstream side (first common liquid chamber side) and the negative pressure on the downstream side (second common liquid chamber side) with respect to the channel are employed by adopting the circulation type liquid jet head. The pressure balance can be kept even.

In addition, a partition wall is provided between the first pressure buffer portion and the second pressure buffer portion, and the partition wall communicates with the first pressure buffer portion and the second pressure buffer portion. In addition, the flow passage cross-sectional area is larger than the first communication path that connects the first pressure buffering section and the first common liquid chamber, and the second communication path that connects the second pressure buffering section and the second common liquid chamber. A small bypass path may be formed.
According to this configuration, it is possible to circulate bubbles between the respective pressure buffering portions while suppressing the flow of the liquid through the bypass passage. In this case, the bubbles in the first pressure buffering part bypass the channel and are discharged into the second pressure buffering part. Thereby, it is possible to suppress the retention of bubbles in the channel and to suppress the occurrence of injection failure.

The liquid ejecting apparatus according to the present invention includes the liquid ejecting head according to the present invention, and a moving mechanism that relatively moves the liquid ejecting head and the recording medium.
According to this configuration, since the liquid ejecting head according to the invention is provided, a liquid ejecting apparatus having excellent printing stability can be provided.

  According to the present invention, it is possible to provide a liquid ejecting head and a liquid ejecting apparatus having excellent printing stability.

It is a schematic block diagram of an inkjet printer. It is a schematic block diagram of an inkjet head and an ink circulation means. It is a disassembled perspective view of an inkjet head. It is a bottom view of the inkjet head in the state where the nozzle plate was removed. FIG. 5 is a cross-sectional view corresponding to the line VV in FIG. 4. It is sectional drawing equivalent to the VI-VI line of FIG. It is the top view which looked at the channel member from the one end side of the Z direction. It is the top view which looked at the channel member from the other end side of the Z direction. It is the perspective view which looked at the channel member from the one end side of the Z direction. It is the perspective view which looked at the channel member from the other end side of the Z direction. It is the top view which looked at the channel member which shows other composition of an embodiment from the other end side of the Z direction.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following embodiments, as an example of a liquid ejecting apparatus including the liquid ejecting head of the present invention, an ink jet printer (hereinafter simply referred to as a printer) that performs recording on recording paper using ink (liquid) is taken as an example. explain. In the drawings used for the following description, the scale of each member is appropriately changed in order to make each member a recognizable size.

(First embodiment)
[Printer]
FIG. 1 is a schematic configuration diagram of the printer 1.
As shown in FIG. 1, a printer 1 according to the present embodiment includes a pair of conveying means (moving mechanisms) 2 and 3 that convey recording paper (recording medium) P such as paper, and an ink tank 4 that contains ink. An ink jet head (liquid ejecting head) 5 that ejects droplet-like ink onto the recording paper P, an ink circulating means 6 that circulates ink between the ink tank 4 and the ink jet head 5, and the ink jet head 5. A scanning unit (moving mechanism) 7 that scans in a direction (width direction of the recording paper P, hereinafter referred to as Y direction) orthogonal to the conveyance direction (hereinafter referred to as X direction) of the paper P is provided. In the figure, the Z direction indicates a height direction orthogonal to the X direction and the Y direction.

  The conveying means 2 includes a grid roller 11 extending in the Y direction, a pinch roller 12 extending in parallel to the grid roller 11, a drive mechanism (not shown) such as a motor for rotating the grid roller 11, and the like. It has. Similarly, the conveying means 3 includes a grid roller 13 extending in the Y direction, a pinch roller 14 extending in parallel to the grid roller 13, a drive mechanism (not shown) that rotates the grid roller 13 in an axis, It has.

  The ink tank 4 is provided with, for example, ink tanks 4Y, 4M, 4C, and 4B of four colors of yellow, magenta, cyan, and black arranged in the X direction.

FIG. 2 is a schematic configuration diagram of the inkjet head 5 and the ink circulation means 6.
As shown in FIGS. 1 and 2, the ink circulation means 6 includes an ink supply pipe 21 that supplies ink to the inkjet head 5, and a circulation flow path 23 that has an ink discharge pipe 22 that discharges ink from the inkjet head 5; A pressurizing pump 24 connected to the ink supply pipe 21 and a suction pump 25 connected to the ink discharge pipe 22 are provided. The ink supply pipe 21 and the ink discharge pipe 22 are made of a flexible hose having flexibility that can cope with the operation of the scanning means 7 that supports the inkjet head 5.

The pressurizing pump 24 pressurizes the inside of the ink supply pipe 21, and sends out ink to an inlet-side common ink chamber 90 (see FIG. 3), which will be described later, of the inkjet head 5 through the ink supply pipe 21. Thereby, the ink supply pipe 21 side has a positive pressure with respect to the inkjet head 5.
The suction pump 25 depressurizes the inside of the ink discharge pipe 22 and sucks ink from outlet side common ink chambers 91a and 91b (see FIG. 3) described later of the inkjet head 5. Thereby, the ink discharge pipe 22 side has a negative pressure with respect to the inkjet head 5. The ink can be circulated between the inkjet head 5 and the ink tank 4 through the circulation flow path 23 by driving the pressurizing pump 24 and the suction pump 25.

  As shown in FIG. 1, the scanning means 7 includes a pair of guide rails 31 and 32 extending in the Y direction, a carriage 33 movably supported by the pair of guide rails 31 and 32, and the carriage 33 as a Y-axis. And a drive mechanism 34 that moves in the direction. The drive mechanism 34 rotates a pair of pulleys 35, 36 disposed between the pair of guide rails 31, 32, an endless belt 37 wound between the pair of pulleys 35, 36, and one pulley 35. And a drive motor 38 to be driven.

  The pair of pulleys 35 and 36 are respectively disposed between both ends of the pair of guide rails 31 and 32. The endless belt 37 is disposed between the pair of guide rails 31 and 32, and the carriage 33 is connected to the endless belt 37. On the carriage 33, as a plurality of ink-jet heads 5, ink-jet heads 5Y, 5M, 5C, and 5B of four colors of yellow, magenta, cyan, and black are mounted side by side in the Y direction. The transporting means 2 and 3 and the scanning means 7 constitute a moving mechanism that relatively moves the inkjet head 5 and the recording paper P.

<Inkjet head>
Next, the above-described inkjet head 5 will be described in detail. The ink jet heads 5Y, 5M, 5C, and 5B have the same configuration except for the color of the supplied ink. Therefore, in the following description, the ink jet heads 5 will be collectively described.
3 is an exploded perspective view of the inkjet head 5, and FIG. 4 is a bottom view of the inkjet head 5 with the nozzle plate 51 removed.
As shown in FIGS. 3 and 4, each inkjet head 5 is a so-called side chute type that ejects ink from a central portion in an extending direction (Y direction (first direction)) of an ejection channel 71 described later. This is a circulation type inkjet head 5 that circulates ink between the ink tank 4. In addition, the inkjet head 5 of the present embodiment is a two-row type inkjet head 5 in which nozzle rows 87 and 88 including a plurality of nozzle holes (ejection holes) 85 and 86 are formed in two rows.

  The inkjet head 5 mainly includes a nozzle plate 51, an actuator plate 52, a cover plate 53, and a flow path member 54. The inkjet head 5 has a configuration in which the nozzle plate 51, the actuator plate 52, the cover plate 53, and the flow path member 54 are laminated in this order by an adhesive or the like. In the following description, in the Z direction described above, the nozzle plate 51 side (lower side in FIG. 3) will be described as one end side, and the flow channel member 54 side (upper side in FIG. 3) will be described as the other end side.

<Actuator plate>
5 is a cross-sectional view corresponding to line VV in FIG. 4, and FIG. 6 is a cross-sectional view corresponding to line VI-VI in FIG.
As shown in FIGS. 5 and 6, the actuator plate 52 is formed of a piezoelectric material such as PZT (lead zirconate titanate), and the polarization direction is set in one direction along the thickness direction (Z direction). ing. The actuator plate 52 is provided with two channel rows (first channel row 63 and second channel row 64) each including a plurality of channels 71 and 72 arranged in parallel in the X direction (second direction). It is installed. In the following description, the first channel column 63 will be mainly described, and portions corresponding to the first channel column 63 in the second channel column 64 are denoted by the same reference numerals and description thereof is omitted.

  The first channel row 63 includes a plurality of channels 71 and 72 extending in the Y direction and arranged in parallel to each other with an interval in the X direction. That is, each of the channels 71 and 72 is linearly formed in the Y direction and equally spaced in the X direction, and is defined by the drive wall 65 made of a piezoelectric body (actuator plate 52).

Specifically, the plurality of channels 71 and 72 have an ejection channel (channel) 71 filled with ink and a dummy channel 72 not filled with ink. The discharge channels 71 and the dummy channels 72 are arranged alternately in the X direction.
As shown in FIGS. 3 and 6, the ejection channel 71 has a convex curved shape toward one end side in the Z direction when viewed from the side in the X direction. Specifically, the discharge channel 71 has a rounded-up portion 66 that extends while curving toward one end side in the Z-direction as it goes from both ends in the Y-direction to the central portion, and an intermediate portion 67 positioned between the round-up portions 66. And have. The discharge channel 71 opens on the first main surface 52 a located on one end side in the Z direction in the actuator plate 52 through the intermediate portion 67, and passes through the raised portion 66 and the intermediate portion 67 on the other end side in the Z direction. 2 Open on the main surface 52b. That is, in the actuator plate 52, a portion located at the intermediate portion 67 of the discharge channel 71 penetrates in the Z direction.

  The dummy channel 72 has a convex curved shape toward the other end side in the Z direction when viewed from the side in the X direction. That is, the dummy channel 72 has a shape inverted with respect to the ejection channel 71 in the Z direction. Specifically, the dummy channel 72 includes a rounded-up portion 68 that extends while curving toward the other end side in the Z-direction from both ends in the Y-direction toward the central portion, and an intermediate portion positioned between the round-up portions 68. 69. The dummy channel 72 opens on the first main surface 52 a of the actuator plate 52 through the raised portion 68 and the intermediate portion 69, and opens on the second main surface 52 b of the actuator plate 52 through the intermediate portion 69. That is, in the actuator plate 52, the portion located at the intermediate portion 69 of the dummy channel 72 penetrates in the Z direction.

  Accordingly, the discharge channel 71 and the dummy channel 72 have different opening lengths in the Y direction on both the main surfaces 52a and 52b of the actuator plate 52. As shown in FIG. 4, the first channel row 63 has an opening length of the dummy channel 72 longer than the opening length of the discharge channel 71 on the first main surface 52a. The opening length of the discharge channel 71 is longer than the opening length of the dummy channel 72 on 52b. In this case, as shown in FIG. 4, the dummy channel 72 protrudes on both sides in the Y direction from the discharge channel 71 by the length of the two raised portions 68 on the first main surface 52 a. Further, as shown in FIG. 3, on the second main surface 52 b, the discharge channel 71 protrudes on both sides in the Y direction from the dummy channel 72 by the length of the two raised portions 66.

  As shown in FIG. 6, a shallow groove portion 77 is formed in a portion of the first tail portion 70A, which will be described later, of the actuator plate 52 that is located outside (one end side) in the Y direction with respect to the dummy channel 72. Yes. The shallow groove portion 77 has an inner end portion in the Y direction communicating with the dummy channel 72, and an outer end portion in the Y direction is opened at the outer end surface in the Y direction of the actuator plate 52.

  As shown in FIGS. 3 and 4, the second channel row 64 is formed by alternately arranging discharge channels 71 and dummy channels 72 in the same manner as the first channel row 63 described above. Are arranged at intervals in the Y direction. Specifically, the discharge channels 71 and the dummy channels 72 in the second channel row 64 are arranged with a half-pitch shift from the arrangement pitch of the discharge channels 71 and the dummy channels 72 in the first channel row 63. Therefore, in the inkjet head 5 of this embodiment, the ejection channels 71 of the first channel row 63 and the second channel row 64 and the dummy channels 72 of the first channel row 63 and the second channel row 64 are staggered (staggered). ). That is, between the adjacent channel rows 63 and 64, the discharge channel 71 and the dummy channel 72 are opposed to each other in the Y direction. In the actuator plate 52, both end portions in the Y direction (portions located outside the Y direction with respect to the channel rows 63 and 64 respectively constitute tail portions (first tail portion 70A and second tail portion 70B). .

  Here, as shown in FIG. 3 and FIG. 6, between the adjacent channel rows 63 and 64, the discharge channel 71 and the dummy channel 72 facing each other in the Y direction are positions where inner end portions in the Y direction overlap in the Z direction. Are arranged close to each other. Specifically, in the discharge channel 71 of the first channel row 63 and the dummy channel 72 of the second channel row 64 facing each other in the Y direction, part of the raised portions 66 and 68 located inside the Y direction are in the Z direction. Are overlapping. On the other hand, in the dummy channel 72 of the first channel row 63 and the discharge channel 71 of the second channel row 64 facing each other in the Y direction, part of the raised portions 68 and 66 located inside the Y direction overlap in the Z direction. ing.

  As shown in FIG. 3 to FIG. 6, a common electrode is formed on the inner surface (the surface facing the Y direction among the inner surfaces of the discharge channels 71) of the drive wall 65 of the actuator plate 52 that faces each discharge channel 71. 73 is formed. These common electrodes 73 have a width in the Z direction that is about half that of the discharge channel 71, and are formed on the inner surface of each discharge channel 71 in a range from one end edge in the Z direction to the middle portion. The common electrode 73 has the same length in the Y direction as that of the intermediate portion 67 of the discharge channel 71 (equivalent to the opening length of the discharge channel 71 on the first main surface 52a).

  As shown in FIGS. 4 and 6, the tail portions 70A and 70B on the first main surface 52a of the actuator plate 52 are electrically connected to a common electrode 73 and flexible printed boards 80 and 81 to be described later. Common wiring 74 is formed. The common wiring 74 has a belt-like shape extending in parallel with each other along the Y direction, and an inner end portion in the Y direction is connected to the common electrode 73 of the discharge channel 71 and is connected to the discharge channel 71 in the Y direction. It is pulled out to the outside.

As shown in FIGS. 3, 5, and 6, individual electrodes 75 are formed on the inner surface of each of the drive walls 65 of the actuator plate 52 facing each dummy channel 72. These individual electrodes 75 have a width in the Z direction that is about half that of the dummy channels 72, and are formed on the inner surface of each dummy channel 72 in a range from one end edge in the Z direction to the middle portion. In this case, among the individual electrodes 75, the individual electrodes 75 facing each other in the same dummy channel 72 are electrically separated from each other. The individual electrode 75 is also connected to the inner side surface of the shallow groove portion 77.
On the other hand, the individual electrodes 75 facing each other with the ejection channel 71 interposed therebetween are electrically connected to each other at the tail portions 70A and 70B via the individual wiring 76 positioned outside the common wiring 74 in the Y direction.

  As shown in FIG. 4, on the first main surface 52a of the actuator plate 52, the first flexible printed circuit board 80 connected to the respective wirings 74 and 76 on the first channel row 63 side is pressure-bonded to the first tail portion 70A. Has been. On the other hand, a second flexible printed circuit board 81 connected to each wiring 74, 76 on the second channel row 64 side is pressure-bonded to the second tail portion 70B.

<Nozzle plate>
As shown in FIG. 3, the nozzle plate 51 is made of a film material such as polyimide having a thickness of about 50 μm, and is bonded onto the first main surface 52 a of the actuator plate 52. The nozzle plate 51 is narrower in the Y direction than the actuator plate 52 and exposes the outer end portions (tail portions 70A and 70B) of the actuator plate 52 in the Y direction. And the flexible printed circuit boards 80 and 81 mentioned above are crimped | bonded by the part exposed from the nozzle plate 51 among the actuator plates 52, respectively.

  The nozzle plate 51 includes a plurality of nozzle holes (first nozzle holes 85 and second nozzle holes 86) arranged in parallel at intervals in the X direction (first nozzle array 87 and second nozzle array 88). ) Are arranged in two rows.

The first nozzle row 87 has a plurality of first nozzle holes 85 penetrating the nozzle plate 51 in the Z direction, and these first nozzle holes 85 are arranged in a straight line at intervals in the X direction. . These first nozzle holes 85 communicate with the discharge channels 71 of the first channel row 63 described above.
The second nozzle row 88 has a plurality of second nozzle holes 86 that penetrate the nozzle plate 51 in the Z direction, and is arranged in parallel with the first nozzle row 87 described above. Each second nozzle hole 86 communicates with the discharge channel 71 of the second channel row 64 described above. Therefore, each dummy channel 72 does not communicate with the nozzle holes 85 and 86 but is covered by the nozzle plate 51 from one end side in the Z direction.

<Cover plate>
As shown in FIG. 3, the cover plate 53 has a plate shape that is bonded onto the second main surface 52 b of the actuator plate 52 so as to close the channel rows 63 and 64.
As shown in FIGS. 3 and 6, the cover plate 53 is formed with an inlet-side common ink chamber 90 and an outlet-side common ink chamber (a first outlet-side common ink chamber 91 a and a second outlet-side common ink chamber 91 b). Has been.

  The entrance-side common ink chamber 90 is a slit that extends through the cover plate 53 in the X direction. The inlet-side common ink chamber 90 is opposed to the inner ends in the Y direction of the discharge channels 71 of the channel rows 63 and 64 in the Z direction, and communicates together in the discharge channels 71.

The first outlet side common ink chamber 91a is a slit that extends through the cover plate 53 along the X direction. The first outlet-side common ink chamber 91 a faces the outer end in the Y direction of the discharge channel 71 of the first channel row 63 in the Z direction, and communicates together in the discharge channel 71 of the first channel row 63. .
The second outlet-side common ink chamber 91 b faces the outer end portion in the Y direction of the discharge channel 71 of the second channel row 64 in the Z direction, and communicates together in the discharge channel 71 of the second channel row 64. .
Therefore, the inlet-side common ink chamber 90 and the outlet-side common ink chambers 91 a and 91 b communicate with the respective ejection channels 71, but do not communicate with the dummy channel 72.

<Flow channel member>
7 is a plan view of the flow path member 54 as viewed from one end side in the Z direction, and FIG. 8 is a plan view of the flow path member 54 as viewed from the other end side in the Z direction. FIG. 9 is a perspective view of the flow path member 54 as viewed from one end side in the Z direction, and FIG. 10 is a perspective view of the flow path member 54 as viewed from the other end side in the Z direction.
As shown in FIGS. 6 to 10, the flow path member 54 includes a plate-shaped flow path plate 92 bonded on the cover plate 53 so as to close the common ink chambers 90, 91 a, 91 b, and the flow path plate. And a film 94 which is bonded onto 92 and defines the inlet side pressure buffering portion 93 and the outlet side pressure buffering portion 99 in cooperation with the flow path plate 92. The flow path plate 92 has a rectangular shape that is long in the X direction in a plan view as viewed from the Z direction.

  The flow path plate 92 is connected to the introduction port 95 to which the ink supply pipe 21 described above is connected, the lead-out port 96 to which the ink discharge pipe 22 is connected, and the ink supply that connects the introduction port 95 and the common ink chamber 90 on the inlet side. And a discharge port 98 for connecting the outlet port 96 and the outlet-side common ink chambers 91a and 91b.

The introduction port 95 is located at the center in the Y direction at one end in the X direction of the flow path plate 92 and extends in the Z direction. In the introduction port 95, the upstream opening along the ink flow direction is opened toward the other end in the Z direction, and the downstream opening is opened toward the inside in the X direction at one end in the Z direction. Has been.
The derivation port 96 is located in the center portion in the Y direction at the other end portion in the X direction of the flow path plate 92 and extends in the Z direction. Of the outlet port 96, the upstream opening is opened toward the inside in the X direction at one end in the Z direction, and the downstream opening is opened toward the other end in the Z direction.

  The ink supply unit 97 includes an inlet-side communication chamber 100 that communicates with the inlet-side common ink chamber 90, an inlet-side storage unit 101 that is located upstream of the inlet-side communication chamber 100, and the inlet-side storage unit 101 and the inlet side. A communication path 102 that connects between the communication chambers 100 and an introduction path 103 that connects between the inlet-side accommodation portion 101 and the introduction port 95 are provided.

  As shown in FIGS. 6, 7, and 9, the inlet side communication chamber 100 is open toward one end side in the Z direction and is a rectangular groove in a sectional view along the Z direction. Among these, in the center part of the Y direction, it extends along the X direction. Further, the inlet side communication chamber 100 covers the entire area of the inlet side common ink chamber 90 from the other end side in the Z direction.

  As shown in FIGS. 6, 8, and 10, the inlet side accommodating portion 101 opens toward the other end side in the Z direction and is a groove having a rectangular cross-sectional shape along the Z direction. 92 is extended to one end portion in the X direction. Specifically, as shown in FIGS. 8 and 10, the inlet side accommodating portion 101 is positioned at one end portion (outer end portion) in the X direction and connected to the upstream guide portion 101 a to which the introduction path 103 is connected, and X A downstream guide portion 101b that is located at the other end portion (inner end portion) in the direction and to which the communication path 102 is connected, and an intermediate flow path 101c that connects the guide portions 101a and 101b. .

The upstream guide part 101a is bifurcated with respect to the intermediate flow path 101c. Specifically, the upstream guide portion 101a has a W shape in plan view as viewed from the Z direction, and the flow path width in the Y direction gradually increases toward the other end side (downstream side) in the X direction. .
The downstream guide portion 101b has a V shape in plan view as viewed from the Z direction, and the flow path width in the Y direction is gradually reduced toward the other end side (downstream side) in the X direction.
The intermediate flow path 101c is formed over almost the entire area of the flow path plate 92 in the Y direction. That is, the intermediate flow path 101 c is formed wider in the Y direction than the inlet side communication chamber 100. In this case, both end portions in the Y direction of the inlet side accommodating portion 101 are extended to positions overlapping with the outlet side common ink chambers 91a and 91b in the Z direction. The intermediate flow path 101c has a uniform flow path width in the Y direction over the entire X direction.

  As shown in FIGS. 6 to 10, the communication path 102 is located at the center of the flow path plate 92 in the X direction and the Y direction, and penetrates the flow path plate 92 in the Z direction. The communication passage 102 has an opening on the one end side in the Z direction that opens at the center in the X direction in the inlet side communication chamber 100. Therefore, the communication path 102 of the present embodiment is located in the center portion in the X direction of the inlet side common ink chamber 90 and the channel rows 63 and 64 in a plan view as viewed from the Z direction. In the example shown in the drawing, the communication passage 102 has an oval shape with the X direction as the major axis direction in a plan view as viewed from the Z direction, and the center thereof is the same as the center in the X direction and the Y direction in the inlet side communication chamber 100. I'm doing it. In addition, the internal diameter of the communicating path 102 is uniform over the whole Z direction.

  On the other hand, in the communication path 102, the other end side opening in the Z direction is opened inside the downstream guide portion 101 b in the inlet side accommodating portion 101. In this case, the communication path 102 is located at the other end portion in the X direction of the downstream guide portion 101b, and is surrounded by the downstream guide portion 101b from the other end side in the X direction.

As shown in FIGS. 7 to 10, the introduction path 103 communicates the introduction groove 110 formed on one end surface of the flow path plate 92 in the Z direction with the inside of the introduction groove 110 and the inlet side pressure buffering portion 93. A pair of introduction holes 111.
As shown in FIGS. 7 and 9, the introduction groove 110 has an upstream end communicating with the downstream end of the introduction port 95, and the downstream side is bifurcated. It extends along the X direction. The introduction groove 110 faces the portion of the actuator plate 52 other than the channel rows 63 and 64 in the Z direction. That is, the introduction groove 110 is closed by the actuator plate 52 and is not in direct communication with the channel rows 63 and 64.

  As shown in FIGS. 7, 8, and 10, each introduction hole 111 penetrates the flow path plate 92 in the Z direction, and has an oval shape with the X direction as the major axis direction when viewed from the Z direction. It is said that. The introduction hole 111 has an upstream end that opens at the downstream end of the introduction groove 110, and a downstream end that opens inside the upstream guide portion 101 a in the inlet side accommodation portion 101. Each introduction hole 111 is positioned at one end portion in the X direction of the upstream guide portion 101a, and is individually surrounded by one end side in the X direction by the upstream guide portion 101a. Further, the inner diameter of each introduction hole 111 is uniform over the entire Z direction.

  As described above, in the inlet side accommodating portion 101, the introduction holes 111 and the communication passages 102 are disposed apart from each other, and each of the introduction holes 111 is located at one end portion in the X direction. Located in the center of the direction. In other words, the communication path 102 is located in an intermediate portion between each introduction hole 111 and the other end portion in the X direction in the channel rows 63 and 64 in a plan view as viewed from the Z direction. In addition, the sum total of the opening area in each introduction hole 111 (for example, the opening area in the inlet side accommodating portion 101) and the opening area in the communication path 102 (for example, the opening area in the inlet side accommodating portion 101) are: It is equivalent. Thereby, the difference in pressure loss when passing through the introduction hole 111 and the communication path 102 can be reduced, and the ink can be circulated smoothly in the flow path member 54.

As shown in FIGS. 6, 7, and 9, the ink discharger 98 includes a pair of outlet side communication chambers 113 that communicate with the respective outlet side common ink chambers 91 a and 91 b, and the outlet side communication chambers 113. The outlet side accommodating portion 115 located on the downstream side, the pair of communication passages 116 connecting the outlet side communication chamber 113 and the outlet side accommodating portion 115, and the outlet path 117 connecting the outlet side accommodating portion 115 and the outlet port 96. And.
Each outlet-side communication chamber 113 opens toward one end side in the Z direction and is a rectangular groove in a cross-sectional view along the Z direction, and in the X direction at both ends of the flow path plate 92 in the Y direction. It extends along. Each outlet-side communication chamber 113 covers each outlet-side common ink chamber 91a, 91b separately from the other end side in the Z direction.

  As shown in FIGS. 8 and 10, the outlet side accommodating portion 115 is a groove having a rectangular cross-sectional shape along the Z direction, like the inlet side accommodating portion 101 described above. While extending to the other end, the length in the X direction is formed to be equal to that of the inlet side accommodating portion 101. Specifically, the outlet side accommodation portion 115 is positioned at one end portion (inner end portion) in the X direction and connected to the communication path 116, and the other end portion (outer end portion) in the X direction. And a downstream guide portion 115b to which the lead-out path 117 is connected, and an intermediate flow path 115c connecting the guide portions 115a and 115b.

The upstream guide portion 115a is bifurcated with respect to the intermediate flow path 115c, and is disposed on both sides in the Y direction with respect to the downstream guide portion 101b of the inlet side accommodating portion 101 described above. That is, the upstream guide portion 115 a of the outlet side accommodation portion 115 is formed to be intricate with respect to the downstream side guide portion 101 b of the inlet side accommodation portion 101 at the center portion in the X direction of the flow path plate 92. The upstream guide portion 115a has a W shape in a plan view as viewed from the Z direction, and the flow path width in the Y direction gradually increases toward the other end side (downstream side) in the X direction.
The downstream guide portion 115b is bifurcated with respect to the intermediate flow path 115c. Specifically, the downstream guide portion 115b has a W shape in a plan view when viewed from the Z direction, and the flow path width in the Y direction gradually decreases toward the other end side (downstream side) in the X direction. .

  The intermediate flow path 115c has a flow path width in the Y direction that is the same as the flow path width of the intermediate flow path 101c of the inlet side accommodating portion 101 described above, and is formed over almost the entire area of the flow path plate 92 in the Y direction. Has been.

  As shown in FIGS. 6 to 8, each communication passage 116 is located at the center portion in the X direction and at both ends in the Y direction in the flow path plate 92, and penetrates the flow path plate 92 in the Z direction. ing. Each communication passage 116 has an opening on one end side in the Z direction that is opened separately in the center in the X direction in each outlet side communication chamber 113. Therefore, the communication path 116 of the present embodiment is located at the center in the X direction in the outlet-side common ink chambers 91a and 91b and the channel rows 63 and 64 in a plan view as viewed from the Z direction.

  Each communication passage 116 has a semi-oval shape with the X direction as the major axis direction in a plan view as viewed from the Z direction, and the center thereof coincides with the center of the outlet side communication chamber 113 in the X direction. In this case, the communication path 116 has the same length in the X direction as that of the communication path 102 of the ink supply unit 97, and is on both sides in the Y direction with respect to the communication path 102 of the ink supply unit 97. In the same position. The communication path 116 has an inner diameter that is larger at one end in the Z direction than at the other end.

  On the other hand, the other end side opening in the Z direction of the communication path 116 is opened inside the upstream guide portion 115 a in the outlet side accommodation portion 115. In this case, the communication path 116 is located at one end portion in the X direction of the upstream guide portion 115a, and is surrounded by one end side in the X direction by the upstream guide portion 115a. Note that the opening area of the ink supply unit 97 in the inlet-side accommodating portion 101 of the communication path 102 is equal to the sum of the opening areas of the ink discharge portions 98 in the outlet-side accommodating portions 115 of the communication paths 116. ing. Thereby, the difference in pressure loss when passing through the communication passages 102 and 116 can be reduced, and the ink can be circulated smoothly in the flow path member 54.

As shown in FIGS. 7 to 10, the lead-out path 117 includes a pair of lead-out holes 121 that penetrate the flow path plate 92 in the Z direction, and a lead-out hole 121 and a lead-out port 96 at one end surface of the flow path plate 92 in the Z direction. And a lead-out groove 122 that connects between the two.
Each lead-out hole 121 has an oval shape in which the X direction is the major axis direction in a plan view viewed from the Z direction. Each outlet hole 121 has an upstream end opened inside the downstream guide portion 115 b in the outlet side accommodation portion 115. Each lead-out hole 121 is located at the other end portion in the X direction of the downstream guide portion 115b, and is individually surrounded by the downstream guide portion 115b from the other end side in the X direction. The inner diameter of each outlet hole 121 is uniform over the entire Z direction.

  The lead-out groove 122 is formed at the other end portion in the X direction in the flow path plate 92 and is opened toward one end side in the Z direction. Specifically, the outlet groove 122 is connected to the outlet hole 121 described above after the downstream end communicates with the upstream end of the outlet port 96 and the upstream end branches in two. Note that the lead-out groove 122 faces the portion of the actuator plate 52 other than the channel rows 63 and 64 in the Z direction. That is, the lead-out groove 122 is closed by the actuator plate 52 and is not in direct communication with the channel rows 63 and 64.

  Here, as shown in FIG. 6, the above-described film 94 that closes the accommodating portions 101 and 115 from the other end side in the Z direction is disposed on the other end surface in the Z direction of the flow path plate 92. The film 94 is formed of a resin material such as polyamide, and has a thickness of, for example, about 15 μm and can be deformed flexibly. The space defined by the inlet side accommodating portion 101 and the film 94 communicates with the inlet side common ink chamber 90 on the upstream side, stores the ink, and is partly bent and deformable. 93. On the other hand, the space defined by the outlet side accommodating portion 115 and the film 94 communicates with the outlet side common ink chambers 91a and 91b collectively on the downstream side, and the ink is discharged and part of the space can be bent and deformed. An outlet side pressure buffering portion 99 is configured. That is, the pressure buffering portions 93 and 99 are arranged side by side in the X direction in the flow path member 54. In this case, the volume of each pressure buffer part 93 and 99 is mutually equivalent.

  In the flow path plate 92, adhesive accommodating portions 120 for accommodating adhesives used for bonding the flow path plate 92, the actuator plate 52, and the film 94 are formed on both end faces in the Z direction. .

[How the printer works]
Next, a case where characters, figures, and the like are recorded on the recording paper P using the printer 1 configured as described above will be described below.
As an initial state, it is assumed that inks of different colors are sufficiently sealed in the four ink tanks 4 shown in FIG. Further, the ink in the ink tank 4 is filled in the inkjet head 5 via the ink circulating means 6.

Under such an initial state, when the printer 1 is operated, the grid rollers 11 and 13 of the transport means 2 and 3 are rotated, so that the recording paper P is interposed between the grid rollers 11 and 13 and the pinch rollers 12 and 14. Are transported in the transport direction (X direction). At the same time, the drive motor 38 rotates the pulleys 35 and 36 to move the endless belt 37. Accordingly, the carriage 33 reciprocates in the Y direction while being guided by the guide rails 31 and 32.
During this time, ink of four colors is appropriately ejected from the respective inkjet heads 5 onto the recording paper P, whereby characters, images, and the like can be recorded.

Here, the movement of each inkjet head 5 will be described in detail below.
In the circulation type inkjet head 5 of the side chute type as in the present embodiment, first, the pressure pump 24 and the suction pump 25 shown in FIG. In this case, the ink flowing through the ink supply pipe 21 flows into the flow path member 54 through the introduction port 95. Specifically, the ink that has flowed into the introduction port 95 flows into the inlet side pressure buffer 93 through the introduction path 103, and then flows into the inlet side communication chamber 100 through the communication path 102. The ink that has flowed into the inlet-side communication chamber 100 flows into the inlet-side common ink chamber 90 and is then supplied into the discharge channels 71 of the channel rows 63 and 64.

  At this time, in this embodiment, since the communication path 102 communicates with the inlet side communication chamber 100 (the inlet side common ink chamber 90) at the center in the X direction, it flows into the inlet side common ink chamber 90. The ink flows in the inlet-side common ink chamber 90 toward both sides in the Y direction. Then, the ink is distributed in each ejection channel 71 in the process of flowing through the inlet-side common ink chamber 90.

  Further, the ink in each ejection channel 71 flows into the respective outlet side common ink chambers 91a and 91b, and then flows into the flow path member 54 from each outlet side communication chamber 113. Specifically, the ink that has flowed into each outlet-side communication chamber 113 flows into the outlet-side pressure buffer 99 through the communication path 116. The ink that has flowed into the outlet pressure buffer 99 flows into the outlet port 96 through the outlet path 117. Thereafter, the ink flowing into the outlet port 96 is returned to the ink tank 4 through the ink discharge pipe 22 and then supplied to the ink supply pipe 21 again. Thereby, the ink is circulated between the inkjet head 5 and the ink tank 4.

  When reciprocation is started by the carriage 33 (see FIG. 1), a voltage is applied between the electrodes 73 and 75 with the common electrode 73 set to the reference potential GND and the individual electrode 75 set to the drive potential Vdd. Then, thickness-slip deformation occurs in the two drive walls 65 that define the discharge channel 71, and the two drive walls 65 are deformed so as to protrude into the discharge channel 71 toward the dummy channel 72. That is, the actuator plate 52 of this embodiment has a single polarization direction, and the electrodes 73 and 75 are formed only up to the middle portion of the drive wall 65 in the Z direction. Therefore, by applying a voltage between the electrodes 73 and 75, the drive wall 65 is bent and deformed into a V shape with the intermediate portion in the Z direction as the center. Thereby, the discharge channel 71 is deformed so as to swell.

Thus, the volume of the discharge channel 71 increases due to the deformation of the two drive walls 65 due to the piezoelectric thickness slip effect. Then, as the volume of the discharge channel 71 increases, the ink stored in the inlet-side common ink chamber 90 is guided into the discharge channel 71. The ink guided to the inside of the discharge channel 71 propagates as a pressure wave to the inside of the discharge channel 71, and is applied between the electrodes 73 and 75 at the timing when the pressure wave reaches the nozzle holes 85 and 86. Set the voltage to zero. As a result, the drive wall 65 is restored, and the volume of the discharge channel 71 once increased returns to the original volume. By this operation, the pressure inside the ejection channel 71 increases and the ink is pressurized. As a result, the ink in the form of droplets is ejected to the outside through the nozzle holes 85 and 86, whereby characters, images, and the like can be recorded on the recording paper P as described above.
The operation of circulating the ink in the discharge channel 71 and the operation of discharging the ink from the discharge channel 71 in the present embodiment may be performed individually or simultaneously.

  Here, in this embodiment, the pressure fluctuation is buffered by the film 94 defining the pressure buffering portions 93 and 99 being bent and deformed according to the pressure fluctuation in the inkjet head 5. First, in the circulation type inkjet head 5 as in the present embodiment, the pressure in the vicinity of the nozzle holes 85 and 86 is always a negative pressure (for example, −) so that a meniscus is formed inside the nozzle holes 85 and 86. The driving of the pressurizing pump 24 and the suction pump 25 is controlled so as to be about 1 kPa. The suction force of the suction pump 25 is set to be higher than the pressurizing force of the pressurizing pump 24.

  In this case, the upstream side (inlet side common ink chamber 90 side) has a positive pressure and the downstream side (outlet side common ink chambers 91a and 91b side) has a negative pressure with respect to the channel rows 63 and 64. Therefore, the film 94 of the inlet side pressure buffering portion 93 is bent and deformed toward the other end side in the Z direction so as to increase the volume of the inlet side pressure buffering portion 93. On the other hand, the film 94 of the outlet side pressure buffer 99 is bent and deformed toward one end in the Z direction so as to reduce the volume of the outlet side pressure buffer 99.

  In this state, when ink is ejected from the nozzle holes 85 and 86 due to a decrease in the volume of the ejection channel 71 as described above, the pressure in the ejection channel 71 is instantaneously reduced. Then, the pressure fluctuation in the discharge channel 71 becomes a pressure wave and propagates through the common ink chambers 90, 91a, 91b into the pressure buffer portions 93, 99, and the film 94 is bent and deformed. That is, the film 94 is bent and deformed toward one end side in the Z direction so as to reduce the volume in each of the pressure buffer portions 93 and 99. Thereby, the pressure fluctuation generated in the discharge channel 71 can be buffered.

In addition, since the discharge channels 71 are collectively connected to the pressure buffer units 93 and 99 via the common ink chambers 90, 91a, and 91b, pressure fluctuations in any of the discharge channels 71 are caused by the pressure buffers. So-called crosstalk that is propagated to other discharge channels 71 via the portions 93 and 99 can also be suppressed.
In the above description, the pressure fluctuation that occurs during ink ejection has been described. However, the present invention is not limited to this. For example, even when the carriage 33 moves or when ink is supplied / discharged, pressure fluctuations generated in the inkjet head 5 due to the oscillation of the circulation flow path 23 can be buffered by the film 94 being bent and deformed. It is.

Here, in this embodiment, it was set as the structure by which the inlet side pressure buffer part 93 and the outlet side pressure buffer part 99 were arrange | positioned along with the X direction.
According to this structure, the width | variety of the Y direction in each pressure buffer part 93 and 99 can be ensured compared with the case where the pressure buffer parts 93 and 99 are arrange | positioned along with the Y direction. Thereby, it becomes easy to bend and deform pressure buffer parts 93 and 99 (film 94), and it becomes possible to raise a pressure buffer effect more. As a result, the pressure balance on the upstream side and the downstream side with respect to the discharge channel 71 can be kept even, and the inside of the inkjet head 5 can be easily maintained at a desired pressure. In this case, since the pressure center in the inkjet head 5 can be set in the vicinity of the nozzle holes 85 and 86, the meniscus can be stably held, and the ink can be stably discharged.

In addition, the communication paths 102 and 116 communicate with each other at the central portion in the X direction in each of the common ink chambers 90, 91a, and 91b.
According to this configuration, for example, the communication passages 102 and 116 are connected to the common ink chambers 90, 91 a, and 91 b at one end in the X direction, and the communication channels 102 and 116 are the most out of the discharge channels 71. The distance in the X direction between the discharge channel 71 and the communication paths 102 and 116 that are separated from each other can be shortened (halved). Thereby, the pressure difference between all the discharge channels 71 can be reduced (halved).

  Moreover, since the volume in each pressure buffer part 93 and 99 is equivalent, both pressure buffer effects can be made equivalent. As a result, the pressure balance on the upstream side and the downstream side with respect to the discharge channel 71 can be maintained more evenly.

  And since the printer 1 of this embodiment is equipped with the inkjet head 5 mentioned above, the printer 1 excellent in printing stability can be provided.

  The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the ink jet printer 1 is described as an example of the liquid ejecting apparatus, but the present invention is not limited to the printer. For example, a fax machine or an on-demand printer may be used.

In the above-described embodiment, the case where the nozzle rows 87 and 88 each extend linearly along the X direction has been described. However, the present invention is not limited thereto, and for example, the nozzle rows 87 and 88 extend obliquely. You may do it.
Further, the shape of the nozzle holes 85 and 86 is not limited to a circle. For example, a polygonal shape such as a triangle, an elliptical shape, or a star shape may be used.
In the above-described embodiment, the configuration in which the ejection channels 71 and the dummy channels 72 are arranged in a staggered manner with a half-pitch shift between the channel rows 63 and 64 has been described, but the present invention is not limited thereto. The discharge channels 71 and the dummy channels 72 may be formed at different positions in the X direction.

  Furthermore, in the above-described embodiment, the two-row type inkjet head 5 in which the nozzle rows 87 and 88 are arranged in two rows has been described. However, the present invention is not limited to this, and the nozzle row may be a single row or a plurality of three or more rows. It does not matter.

In the above-described embodiment, the circulation type in which ink circulates between the inkjet head 5 and the ink tank 4 among the side chute types has been described, but the invention is not limited thereto. For example, in the side chute type, the ink may be supplied from the both ends of the ejection channel 71 toward the nozzle holes 85 and 86.
Further, in the above-described embodiment, the case where the raised portions 66 and 68 are formed in an arc shape has been described. I do not mind.

  Furthermore, in the above-described embodiment, the case where the actuator plate 52 whose polarization direction is one direction in the thickness direction has been described, but the present invention is not limited to this. For example, a so-called chevron actuator plate 52 in which two piezoelectric bodies having different polarization directions are stacked may be used.

  Further, as shown in FIG. 11, a bypass path 130 that bypasses the discharge channel 71 may be formed in the flow path member 54. Specifically, the bypass passage 130 penetrates the partition wall 131 that partitions the accommodating portions 101 and 115 in the passage plate 92 in the X direction. The bypass passage 130 is sufficiently smaller in cross-sectional area than the communication passage 102 described above. Thereby, the circulation of the ink through the bypass path 130 is suppressed, and the bubbles are actively circulated. In the illustrated example, the bypass passage 130 is formed at one end edge of the partition wall 131 in the Z direction and does not communicate with the communication passages 102 and 116.

According to this configuration, as described above, when the ink flows into the inlet side pressure buffering portion 93, the bubbles present in the inlet side pressure buffering portion 93 are pushed out to the ink and pass through the bypass passage 130 to exit the outlet side pressure buffer. It is discharged into the part 99. Thereafter, the bubbles discharged into the outlet side pressure buffer 99 are discharged to the outside of the inkjet head 5 through the outlet port 96. That is, in the present embodiment, bubbles in the inlet side pressure buffering portion 93 bypass the discharge channel 71 and are discharged into the outlet side pressure buffering portion 99. Thereby, it is possible to suppress the retention of bubbles in the ejection channel 71 and to prevent the occurrence of ink ejection failure.
The bypass 130 is preferably disposed on the surface of the flow path plate 92 on the other end side in the Z direction. By disposing in this way, the bubbles accumulated on the upper side in the vertical direction can be positively discharged into the outlet side pressure buffer unit 99 according to the buoyancy.

  In addition, in the flow path plate 92, the bypass path 130 is formed on the opposite side of the introduction path 103 with the communication path 102 therebetween, so that the ink can smoothly flow into the inlet side pressure buffer section 93. At the same time, the inflow of ink into the bypass passage 130 can be suppressed. In the above-described configuration, the inlet side pressure buffering portion 93 and the outlet side pressure buffering portion 99 are connected by the bypass passage 130. However, if the discharge channel 71 is bypassed, the position of the bypass passage 130 is Design changes can be made as appropriate.

  In the above-described embodiment, the configuration in which the communication paths 102 and 116 communicate with each other in the central portion in the X direction in each common ink chamber 90, 91a, and 91b has been described. That is, if the introduction path and the communication path 102 are separated from each other in the inlet side pressure buffering section 93 and the outlet path and the communication path 116 are separated from each other in the outlet side pressure buffering section 99, their layouts can be appropriately changed in design. Is possible.

  In addition, in the range which does not deviate from the meaning of this invention, it is possible to replace suitably the component in the embodiment mentioned above by a known component, and you may combine each modification mentioned above suitably.

1 ... Inkjet printer (liquid ejecting device)
2, 3 ... Conveying means (moving mechanism)
5, 5Y, 5M, 5C, 5B ... Inkjet head (liquid ejecting head)
7. Scanning means (moving mechanism)
52 ... Actuator plate 53 ... Cover plate 54 ... Flow path member 63 ... First channel row (channel row)
64 ... second channel row (channel row)
71: Discharge channel (channel)
90 ... Common ink chamber on the inlet side (first common liquid chamber)
91a: first outlet side common ink chamber (second common liquid chamber)
91b ... second outlet side common ink chamber (second common liquid chamber)
93 ... Inlet side pressure buffer (first pressure buffer)
99 ... Outlet side pressure buffer (second pressure buffer)
102. Communication path (first communication path)
116 ... Communication passage (second communication passage)
130 ... Bypass 131 ... Partition wall

Claims (7)

An actuator plate having a channel row in which channels extending along the first direction are juxtaposed in a second direction orthogonal to the first direction;
A first common liquid chamber that communicates with the plurality of channels at one end in the first direction; and a second common liquid chamber that communicates with the plurality of channels at the other end in the first direction. A cover plate stacked on the actuator plate;
Laminated on the cover plate and provided with a flow path member that is long in the second direction,
The flow path member is
A first pressure buffering portion communicating with the first common liquid chamber and capable of bending deformation;
A second pressure buffering portion that communicates with the second common liquid chamber and is capable of bending deformation.
The liquid ejecting head, wherein the first pressure buffering section and the second pressure buffering section are arranged side by side in a second direction. The first pressure buffering portion communicates with the central portion in the second direction in the first common liquid chamber through the first communication passage,
The liquid ejecting head according to claim 1, wherein the second pressure buffering portion communicates with a central portion in the second direction in the second common liquid chamber through the second communication passage.   The liquid ejecting head according to claim 2, wherein the first communication path and the second communication path have the same opening area.   4. The liquid ejecting head according to claim 1, wherein the first pressure buffering unit and the second pressure buffering unit have the same volume. 5.   The liquid flows into the channel through the first pressure buffer and the first common liquid chamber, and the liquid is discharged through the second common liquid chamber and the second pressure buffer. The liquid jet head according to any one of claims 1 to 4. Between the first pressure buffering portion and the second pressure buffering portion, a partition wall for partitioning both is provided,
The partition wall communicates with the first pressure buffer and the second pressure buffer, and communicates with the first pressure buffer and the first common liquid chamber, and a second pressure buffer. 6. The liquid jet head according to claim 5, wherein a bypass passage having a smaller channel cross-sectional area than a second communication passage that communicates the inside of the section and the second common liquid chamber is formed. The liquid jet head according to any one of claims 1 to 6,
A liquid ejecting apparatus comprising: a moving mechanism that relatively moves the liquid ejecting head and the recording medium.

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