JP2012131148A - Liquid ejecting head, liquid ejecting unit, and liquid ejecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid ejecting head including a circulation path which has a more uniform ejection property, and a liquid ejecting apparatus.SOLUTION: The liquid ejecting head comprises: a plurality of nozzle openings that eject liquid; a first flow path that is communicated with the plurality of nozzle openings and in which the liquid is circulated; a supply path that supplies the liquid to the first flow path from an outside; a recovery path that recovers the liquid from the first flow path to the outside; a first filter 132 that is provided in the supply path; a second filter 134 that is provided in the recovery path; and a second flow path that connects the supply path provided in an upstream side of the first filter 132 and the recovery path provided in a downstream side of the second filter 134, wherein a recovery side flow path 171 between the first flow path and the second flow path of the recovery path has a flow path resistance which is lower than flow path resistance of a supply side flow path 161 between the first flow path and the second flow path of the supply path.

Description

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

Conventionally, in an ink jet recording apparatus which is an example of a liquid ejecting apparatus, an ink tank is provided separately from an ink jet recording head, and a circulation type ink jet recording apparatus that circulates ink between the ink tank and the ink jet recording head is provided. Are known. (For example, refer to Patent Document 1).

In the ink jet recording apparatus described in Patent Document 1, an ink tank is provided with one forward pipe and one backward pipe, and the forward pipe and the backward pipe are branched to supply ink to each recording head. . In each recording head, a circulation path on the upstream side of the filter and a circulation path on the downstream side of the filter are formed, and by including these two circulation paths,
While improving the discharge | emission property of a bubble, sedimentation of a liquid component is suppressed.

JP 2009-23289 A (refer to FIG. 3 etc.)

However, in the ink jet recording head described in Patent Document 1, it is difficult for ink to be introduced into the downstream circulation path, and hence the problem is that the discharge of bubbles is low and the sedimentation of liquid components cannot be suppressed. There is. Furthermore, such an ink jet recording head has a problem that ink is not ejected uniformly from all the nozzles when ink is ejected. Such a problem exists not only in a liquid ejecting apparatus using an ink jet recording head but also in a liquid ejecting apparatus using a liquid ejecting head that ejects liquid other than ink.

Accordingly, an object of the present invention is to solve the above-described problems of the prior art, and a liquid ejecting head having a circulation path having more uniform ejecting characteristics, a liquid ejecting unit including the liquid ejecting head, and a liquid ejecting The device is to be provided.

The liquid ejecting head of the present invention includes a plurality of nozzle openings for ejecting liquid, a first flow path through which the liquid flows in communication with the plurality of nozzle openings, and a supply for supplying liquid from the outside to the first flow path A path, a recovery path for recovering liquid from the first flow path to the outside, a first filter provided in the supply path, a second filter provided in the recovery path, and an upstream side of the first filter A second flow path connecting the supply path on the side and the recovery path downstream of the second filter, and a recovery between the first flow path and the second flow path of the recovery path The side flow path has a flow path resistance lower than that of the supply side flow path between the first flow path and the second flow path of the supply path. In the present invention, the collection-side flow path has a lower flow resistance than the supply-side flow path, thereby increasing the amount of ink supplied to the nozzle openings in the vicinity of the collection-side flow path at the time of liquid ejection. The injection amount can be sufficiently maintained. Thereby, the liquid ejection characteristics can be made substantially uniform. The supply-side flow path includes a first filter provided in the supply path, and the recovery-side flow path includes a second filter provided in the recovery path.

Here, the cross-sectional area of the recovery side flow path is larger than the cross-sectional area of the supply side flow path, or the total area of the opening of the second filter provided in the recovery path is provided in the supply path. It is preferable that the total area of the opening of the first filter is larger. With this configuration, it is possible to reduce the flow path resistance of the collection side flow path. The cross-sectional area refers to a cross-sectional area of a surface perpendicular to the liquid flow direction in the head-side recovery path or the head-side supply path.

It is preferable that the supply side channel has the same channel resistance as the channel resistance of the channel including the recovery side channel and the second channel. By comprising in this way, it can be made more uniform. In the present invention, “same” includes substantially the same.

A liquid ejecting head unit according to the present invention includes a plurality of any of the liquid ejecting heads described above. By providing such a liquid ejecting head unit with uniform liquid ejecting characteristics, the liquid ejecting head unit of the present invention is excellent in liquid ejecting characteristics when mounted on a liquid ejecting apparatus.

The liquid ejecting apparatus according to the aspect of the invention includes any one or more of the liquid ejecting heads described above. By providing a liquid ejecting head with uniform liquid ejecting characteristics,
The liquid ejecting apparatus of the present invention is excellent in liquid ejecting characteristics.

It is a perspective view which shows schematic structure of a liquid ejecting apparatus. It is a schematic diagram which shows the structure of a liquid flow path. It is a cross-sectional schematic diagram of a head. It is a cross-sectional schematic diagram showing the flow of ink in the head during ejection. It is a disassembled perspective view which shows schematic structure of a head. It is the top view and sectional drawing of a head.

The liquid ejecting apparatus of the present invention will be described with reference to FIGS. The ink jet recording apparatus according to this embodiment fixes a liquid jet head to the ink jet recording apparatus main body, and prints on a recording medium by transporting a recording medium such as recording paper in a direction orthogonal to the nozzle row direction. This is a so-called line type ink jet recording apparatus. An ink jet recording apparatus III shown in FIG. 1 includes a head unit 1, an apparatus main body 2, a paper feed roller 3 that is an example of a moving unit, and a control unit 4.

The head unit 1 has a base plate 18 on which a head group (in FIG. 1, each head group is constituted by four heads 100) composed of a plurality of liquid jet heads (hereinafter referred to as heads) 100 is held. A frame member 19 attached to the
The head unit 1 is fixed to the apparatus main body 2 via the frame member 19.

The apparatus body 2 is provided with a paper feed roller 3. The paper feed roller 3 conveys a recording sheet S (recording medium) such as paper fed to the apparatus main body 2 in the first direction, and the recording sheet S
Is passed through the ink ejection surface side of the head 100. Here, the first direction refers to the relative movement direction of the recording sheet S and the head 100. In this embodiment, since the head unit 1 is fixed to the apparatus main body 2, the recording sheet S is conveyed by the paper feed roller 3.

Based on the print data representing the image printed on the recording sheet S, the control unit 4 transmits a signal to the paper feed roller 3 to convey the recording sheet S, and each head 100 via a wiring (not shown). A drive signal is transmitted to the ink to discharge ink.

Further, the apparatus main body 2 is provided with ink storage means 5 in which ink is stored. In this embodiment, as will be described in detail later, the ink storage unit 5 includes a supply pipe 6 for supplying ink from the ink storage unit 5 to each head 100, and collects ink from each head 100 to the ink storage unit 5. And a recovery pipe 7 for the purpose. That is, in the present embodiment, the ink storage means 5 is provided with the supply pipe 6 and the recovery pipe 7, and the ink flows from the ink storage means 5 through the supply pipe 6 to the ink flow path of each head 100. The ink supplied to the (liquid flow path) and not ejected from the nozzle opening is recovered by the ink storage means 5 via the recovery tube 7. The ink storage means 5 is provided with a heating means (not shown) for heating the stored ink. Thus, in the present embodiment, the supply pipe 6, the recovery pipe 7, and each head 1
An ink circulation path is provided which is composed of 00 ink flow paths and circulates the ink heated from the ink storage means 5.

In such an ink jet recording apparatus III, the recording sheet S is transported in the first direction by the paper feed roller 3, and ink is ejected by the head 100 of the head unit 1 to print an image or the like on the recording sheet S. The

Hereinafter, the ink circulation path will be described in detail with reference to FIGS. 2 and 3. In FIGS. 2 and 3, the ink flow is indicated by arrows. As described above, the ink circulation path includes the supply pipe 6,
An ink flow path formed in each head 100 and a recovery tube 7 are included.

The supply pipe 6 includes a single supply main pipe 61 connected to the ink storage means 5 and a supply sub pipe 62 that is provided in the supply main pipe 61 and supplies ink to each head 100. The recovery pipe 7 is provided in one recovery main pipe 71 connected to the ink storage means 5 and the recovery main pipe 71, and each head 1
And a recovery sub-pipe 72 for recovering ink from 00. Collection main pipe 71 and ink storage means 5
Between these, a pump P is interposed. Due to the negative pressure generated by the pump P, each head 100
The ink is recovered from the head 100 to the ink storage means 5 through the recovery tube 7. The collected ink is supplied again from the ink storage means 5 through the supply pipe 6 to the head 100, so that the ink circulates.

As shown in FIG. 3, each head 100 includes a nozzle body 21 and a head body I (details will be described later) in which a reservoir 101 that is a first flow path communicating with the nozzle opening 21 is formed. An ink flow path between the sub pipe 62 and a flow path member II in which an ink flow path between the head main body I and the recovery sub pipe 72 is formed. The flow path member II is an opening provided on an upper surface thereof, and includes an ink introduction port 110 into which ink is introduced, an upper supply path 120 communicating with the ink introduction port 110, and a lower end portion of the upper supply path 120. One end is connected and upper supply path 1
20 and a connection path (second flow path) 130 communicating with 20.

At the other end of the connection path 130, an upper recovery path 140 for discharging the ink accumulated in the connection path 130 is provided. The upper recovery path 140 is provided on the upper surface of the flow path member II and communicates with an ink discharge port 150 through which ink in the head 100 is discharged. A recovery sub-pipe 72 is connected to the ink discharge port 150. The upper supply path 120, the connection path 130, and the upper recovery path 140 constitute an upper side circulation path.

A first filter port 131 that is an opening is provided on the lower surface side of the connection channel 130 so as to face the upper supply channel 120, and the first filter 132 is provided in the first filter port 131.
Is provided. The first filter port 131 is provided with a head side supply path 160 that communicates with the first filter port 131 via the first filter 132 and is connected to the head body I to supply ink to the head body I. ing. The head side supply path 160 is connected to the head main body I via a first opening 44 provided in a compliance substrate (described later) of the head main body I.
The reservoir 101 is communicated. That is, in the present embodiment, the connection path 130 and the reservoir 10
1 is connected to the head-side supply path 160.

Further, the supply-side flow path 161 referred to in the present invention is a supply-side flow path between the connection path 130 and the reservoir 101. That is, the supply-side flow path 161 includes the head-side supply path 160.
The first filter 132 is included.

The reservoir 101 constitutes a part of the liquid channel in the head body I. Reservoir 1
01 is provided in the pressure generation chambers 12 and the pressure generation chambers 12 and communicates with the nozzle openings 21 that eject ink. That is, the reservoir 101 is a common flow path to which the pressure generating chambers 12 as individual flow paths communicating with the nozzle openings 21 are connected in common. Further, the compliance substrate that seals the reservoir 101 is provided with a second opening 45, and the flow path member II includes:
A head-side recovery path 170 that communicates with the reservoir 101 via the second opening 45 is provided. The head-side recovery path 170 communicates with the second filter port 133 that is an opening provided on the lower surface of the connection path 130 via the second filter 134. That is, the head-side recovery path 170
Connects the connection path 130 and the reservoir 101.

Further, the collection-side channel 171 referred to in the present invention is a collection-side channel between the connection path 130 and the reservoir 101. That is, the collection side flow path 171 is composed of the head side collection path 170.
The second filter 134 is included.

As will be described in detail later, the head-side recovery path 170 has a cross-sectional area perpendicular to the ink flow direction (hereinafter simply referred to as a cross-sectional area) larger than the cross-sectional area of the head-side supply path 160. It is configured. A lower-side circulation path is constituted by the head-side supply path 160, the ink flow path in the head main body I, and the head-side recovery path 170. The upper supply path 120 and the head-side supply path 160 constitute a supply path, and the upper recovery path 140 and the head-side recovery path 1
A recovery path is configured from 70.

The first filter 132 and the second filter 134 are provided to remove bubbles or dust in the ink in order to suppress ejection defects such as missing dots due to bubbles or nozzle clogging due to dust in the ink. is there. The first filter 132 and the second filter 134
As long as it has a sheet-like shape having an opening, for example, a sheet-like shape in which a plurality of fine holes are formed by finely knitting a metal or a metal plate in which fine holes are formed may be used. it can.

In the present embodiment, by having the upper side circulation path, the sedimentation of the ink component that has settled in the flow path of the flow path member II is suppressed, and the air bubbles accumulated in the first filter 132 and the second filter 134 are reduced. It can be recovered. In the present embodiment, by further having a lower circulation path, it is possible to suppress sedimentation of the ink component in the head main body I. As a result, in the liquid ejecting apparatus III of the present embodiment, nozzle clogging and the like are suppressed, and ink ejection characteristics are improved.

An ink ejecting operation in the liquid ejecting apparatus III of the present embodiment will be described. First, during the circulation of ink, the ink supplied from the ink storage means 5 is introduced into the head 100 from the ink introduction port 110 of the flow path member II of the head 100 via the supply main pipe 61 and the supply sub pipe 62. . The introduced ink passes through the upper supply path 120 and is connected to the connection path 13.
0 is supplied. Thereafter, the ink is filtered by the first filter 132, passes through the head side supply path 160, and is introduced from the reservoir 101 of the head body I into the pressure generation chamber 12.

In this case, in the present embodiment, the ink is easily introduced into the lower circulation path.
The connection path 130 is set to have a slightly smaller cross-sectional area so that the flow path resistance is higher than the conventional one. By being configured in this manner, when ink is ejected, the ink easily flows to the lower circulation path and is sufficiently supplied, so that a sufficient amount of ink can be supplied to the head body I, thereby suppressing the precipitation of ink components. it can. If the flow path resistance of the connection path 130 is significantly higher than the conventional one, for example, if it is configured to be higher than the flow path resistance of the downstream circulation path, it is supplied to the head side recovery path 170. Since the ink amount is reduced, the effects of the present embodiment as described later cannot be achieved.

The ink in the reservoir 101 is collected by the pump P from the reservoir 101 through the head side collection path 170 and the upper collection path 140, and the ink in the connection path 130 is collected from the connection path 130 through the upper collection path 140. To be recovered. At the same time, new ink is introduced into the head 100 via the supply pipe 6. In this way, the ink circulates in the head 100.

As described above, when ink is circulated in the head 100 and ink is ejected from the nozzle opening 21, the ink flow is changed as shown in FIG. That is, when ink is ejected, ink is also introduced into the pressure generating chamber 12 from the head-side recovery path 170. In the other flow paths, there is no change in the ink flow.

By the way, as described above, since the flow path resistance of the connection path 130 is configured to be slightly higher than the conventional one, the amount of ink may be reduced on the downstream side (upper recovery path 140 side) of the connection path 130. is there. In this case, if the supply-side flow path and the recovery-side flow path are configured to have the same flow path resistance, the connection path is connected to the head-side recovery path via the second filter at the time of injection. It is also conceivable that the amount of ink introduced is reduced. Therefore, in such a case, the amount of ink ejected from the nozzle openings present on the head side collection path side is smaller than the nozzle openings present on the head side supply path side during ink ejection. That is,
If the flow path resistance of the connection path is slightly increased in order to suppress precipitation of the ink component, there is a problem that the ink ejection amount is not uniform in the direction in which the nozzle openings are arranged side by side.

Therefore, in the present embodiment, the cross-sectional area of the head-side recovery path 170 is made larger than the cross-sectional area of the head-side supply path 160 so that the recovery-side flow path 171 has a lower flow path resistance than the supply-side flow path 161. In other words, the head side recovery path 170 is thicker than the head side supply path 160.
Thereby, since ink easily flows from the connection path 130 to the recovery side flow path 171 at the time of ejection, a sufficient amount of ink can be introduced even at the nozzle opening 21 on the recovery side flow path 171 side. An appropriate amount can be ejected from the nozzle opening 21. Accordingly, the ink ejection amount is substantially uniform in the direction in which the nozzle openings 21 are arranged side by side. In particular, the supply-side flow path 161 is configured so that the flow-path resistances of the connection path 130 and the recovery-side flow path 171 are substantially the same, thereby providing the supply-side flow path 16.
The amount of ink that passes through 1 and the amount of ink that passes through the collection-side flow path 171 become substantially uniform, and the amount of ink ejected is made more uniform in the direction in which the nozzle openings 21 are arranged side by side.

That is, in this embodiment, the flow path resistance of the connection path 130 is slightly increased so that a large amount of ink can be circulated in the downstream circulation path in order to suppress sedimentation of the liquid component. Since the characteristics are not uniform, the flow resistance of the recovery-side flow path 171 is further lowered to make the liquid ejection characteristics substantially uniform.

Thus, in order to reduce the flow path resistance in the recovery side flow path 171, the cross sectional area of the head side recovery path 170 is configured to be larger than the cross sectional area of the head side supply path 160 as in this embodiment. It is not limited to. For example, the total area of the openings of the second filter 134 may be made larger than the total area of the openings of the first filter 132. Thus, the second filter 1
34 by making the aperture ratio of 34 higher than the aperture ratio of the first filter 132.
Is lower than the flow path resistance of the supply side flow path 161, so that ink is sufficiently ejected from the nozzle opening 21 on the head side recovery path 170 side during ink ejection, and the ink ejection characteristics are made uniform. The In addition, a plurality of first filters 132 may be provided in the supply side channel 161.

Hereinafter, the liquid jet head main body will be described with reference to FIGS. 5 and 6. FIG. 5 is an exploded perspective view showing a schematic configuration of an ink jet recording head main body which is an example of a liquid ejecting head, and FIG. 6 is a plan view of the ink jet recording head main body and a sectional view taken along line AA ′.

As shown in the drawing, the flow path forming substrate 10 is made of a silicon single crystal substrate, and an elastic film 50 made of, for example, silicon dioxide is formed on one surface thereof. The flow path forming substrate 10 is anisotropically etched from the other side, so that the flow path forming substrate 10 has a plurality of pressure generating chambers 12 partitioned by a plurality of partition walls 11 in the width direction (short side). Direction). In addition, an ink supply path 14 and a communication path 15 are partitioned by a partition wall 11 on one end side in the longitudinal direction of the pressure generating chamber 12 of the flow path forming substrate 10. In addition, a communication portion 13 that forms a part of the reservoir 101 serving as a common ink chamber (liquid chamber) for each pressure generation chamber 12 is formed at one end of the communication passage 15. That is, the flow path forming substrate 10 is provided with a liquid flow path including a pressure generation chamber 12, a communication portion 13, an ink supply path 14, and a communication path 15.

The ink supply path 14 communicates with one end side in the longitudinal direction of the pressure generation chamber 12 and the pressure generation chamber 12.
Has a smaller cross-sectional area. Each communication path 15 is connected to the pressure generation chamber 1 of the ink supply path 14.
2 has a cross-sectional area larger than the width direction (short direction) of the ink supply path 14. In the present embodiment, the communication passage 15 is formed with the same cross-sectional area as the pressure generation chamber 12. That is,
The flow path forming substrate 10 is connected to the pressure generation chamber 12, the ink supply path 14 having a smaller cross-sectional area in the short direction of the pressure generation chamber 12, the ink supply path 14, and the ink supply path 14. A communication passage 15 having a cross-sectional area larger than the cross-sectional area in the short direction and having a cross-sectional area equivalent to that of the pressure generating chamber 12 is defined by a plurality of partition walls 11.

Further, on the opening surface side of the flow path forming substrate 10, a nozzle plate 20 having a nozzle opening 21 communicating with the vicinity of the end portion of each pressure generating chamber 12 on the side opposite to the ink supply path 14 is provided with an adhesive or It is fixed by an adhesive layer such as a heat welding film. The nozzle plate 20 is made of glass ceramics, a silicon single crystal substrate, stainless steel, or the like.

On the other hand, the elastic film 50 is formed on the side opposite to the opening surface of the flow path forming substrate 10 as described above, and an insulator made of, for example, zirconium oxide (ZrO ₂ ) or the like is formed on the elastic film 50. A film 55 is laminated. Further, the first electrode 60 and the piezoelectric layer 7 are formed on the insulator film 55.
A piezoelectric element 300 composed of 0 and the second electrode 80 is formed. Here, the piezoelectric element 30
0 refers to a portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In the present embodiment, the first electrode 60 is a common electrode of the piezoelectric element 300, and the second electrode 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In any case, a piezoelectric active part is formed for each pressure generating chamber 12. Here, the piezoelectric element 300 and the piezoelectric element 30 are also shown.
The diaphragm that generates displacement by driving 0 is collectively referred to as an actuator device. In addition,
In the present embodiment, the first electrode 60 is provided across the juxtaposed direction of the plurality of piezoelectric elements 300, and the end of the first electrode 60 in the longitudinal direction of the pressure generation chamber 12 is opposed to the pressure generation chamber 12. It was provided so that. In the above-described example, the elastic film 50, the insulator film 55, and the first electrode 60 function as a diaphragm. However, the present invention is not limited to this. For example, the elastic film 50 and the insulator film 55 are provided. Instead, only the first electrode 60 may act as a diaphragm.

The second electrode 80 of each piezoelectric element 300 is connected to a lead electrode 90 made of, for example, gold (Au) or the like, and the piezoelectric element 300 is connected via the lead electrode 90.
A voltage is selectively applied to the.

Further, the protective substrate 30 is provided with a reservoir portion 31 in a region facing the communication portion 13, and the reservoir portion 31 is communicated with the communication portion 13 of the flow path forming substrate 10 as described above. A reservoir 101 serving as a common ink chamber for the pressure generation chamber 12 is configured. Further, in the region between the piezoelectric element holding portion 32 and the reservoir portion 31 of the protective substrate 30, there is a protective substrate 3.
A through hole 33 that penetrates 0 in the thickness direction is provided, and a part of the first electrode 60 and the leading end of the lead electrode 90 are exposed in the through hole 33, and a conductive wire (not shown) is attached to the leading end. A drive circuit for driving the piezoelectric element 300 is electrically connected to the via.

As the protective substrate 30, it is preferable to use substantially the same material as the coefficient of thermal expansion of the flow path forming substrate 10, for example, glass, ceramic material, etc. In this embodiment, the same material as the flow path forming substrate 10, that is, A silicon single crystal substrate having a (110) plane crystal plane orientation was used.

On the protective substrate 30, a compliance substrate 40 comprising a sealing film 41 and a fixing plate 42.
Are joined. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film), and one surface of the reservoir portion 31 is sealed by the sealing film 41. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS)). Since the region of the fixing plate 42 facing the reservoir 101 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 101 is sealed only with a flexible sealing film 41. Has been.

The compliance substrate 40 is provided with a first opening 44 and a second opening 45 (see FIG. 3). As described above, the head side supply path 160 (see FIG. 3) communicates with the first opening 44. The head opening collection path 170 (see FIG. 3) communicates with the second opening 45. This
As described above, the ink is supplied from the ink storage unit 5 (see FIG. 2) to the reservoir 101, and the ink is discharged to the ink storage unit 5 during the bubble discharging operation.

In the head main body I of this embodiment, after taking in ink from an external ink supply means (not shown) and filling the interior from the reservoir 101 to the nozzle opening 21 by the ink filling operation described above, a drive circuit (not shown) In accordance with the recording signal from, a voltage is applied between each of the first electrode 60 and the second electrode 80 corresponding to the pressure generating chamber 12, and the elastic film 5
0, the insulating film 55, the first electrode 60, and the piezoelectric layer 70 are bent and deformed, so that the pressure in each pressure generating chamber 12 is increased and ink droplets are ejected from the nozzle openings 21.

(Other embodiments)
Furthermore, the embodiment of the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the line type ink jet recording apparatus in which each head is fixed is shown. However, the present invention can be used for a so-called serial type ink jet recording apparatus. Note that the serial ink jet recording apparatus is a device that performs printing while moving the liquid ejecting head in a direction intersecting the transport direction of the recording medium. Further, in the above-described embodiment, the one having four heads is shown, but this number is not limited, and for example, one having one head may be used.

In the present embodiment, the first filter 132 and the second filter 134 are provided on the bottom surface (lower surface) of the connection path 130, respectively, but are not limited thereto. First filter 132
May be provided in the head side supply path 160, and the second filter 134 may be provided in the head side collection path 170.

In the present embodiment, the supply pipe 6 that supplies the ink from the ink storage unit 5 to the head 100 and the recovery pipe 7 that collects the ink from the head 100 to the ink storage unit 5 are shown, but these are not limited to the pipe. For example, the flow path may be formed by removing a part of the silicon substrate by etching or the like.

Furthermore, in the above-described embodiment, the ink jet recording head 100 that ejects ink droplets.
The present invention has been described by exemplifying the above, but the present invention is widely intended for all liquid ejecting heads. Examples of the liquid ejecting head include a recording head used for an image recording apparatus such as a printer, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL display, and an electrode formation such as an FED (field emission display). Electrode material ejecting heads used in manufacturing, bioorganic matter ejecting heads used in biochip production, and the like.

5 Ink storage means, 6 Supply pipe, 7 Recovery pipe, 10 Flow path forming substrate, 12
Pressure generating chamber, 13 communicating portion, 14 ink supply path, 20 nozzle plate, 21
Nozzle opening, 41 sealing film, 61 supply main pipe, 62 supply sub pipe, 71 collection main pipe, 72 collection sub pipe, 100 ink jet recording head (liquid ejecting head),
DESCRIPTION OF SYMBOLS 101 Reservoir, 130 Connection path, 132 1st filter, 134 2nd filter, 160 Head side supply path, 170 Head side collection path, 300 Piezoelectric element

Claims (7)

A plurality of nozzle openings for injecting liquid, and a first liquid in communication with the plurality of nozzle openings.
A flow path;
A supply path for supplying liquid from the outside to the first flow path;
A recovery path for recovering liquid from the first flow path to the outside;
A first filter provided in the supply path;
A second filter provided in the recovery path;
A second flow path connecting the supply path upstream of the first filter and the recovery path downstream of the second filter;
The recovery side flow path between the first flow path and the second flow path of the recovery path is the first flow path of the supply path.
A liquid ejecting head having a flow path resistance lower than that of a supply-side flow path between the flow path and the second flow path. The liquid ejecting head according to claim 1, wherein a cross-sectional area of the recovery-side flow path is larger than a cross-sectional area of the supply-side flow path. The total area of the openings of the second filter provided in the recovery path is the first area provided in the supply path.
The liquid ejecting head according to claim 1, wherein the liquid ejecting head is wider than a total area of openings of the filter. The said supply side flow path has the same flow path resistance as the flow path resistance of the flow path which consists of the said collection | recovery side flow path and the said 2nd flow path, The Claim 1 characterized by the above-mentioned. The liquid jet head described. A liquid ejecting head unit comprising a plurality of liquid ejecting heads according to claim 1. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1. A liquid ejecting apparatus comprising a plurality of liquid ejecting heads according to claim 1.

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