WO2018116833A1

WO2018116833A1 - Liquid ejection head and liquid ejection device

Info

Publication number: WO2018116833A1
Application number: PCT/JP2017/043810
Authority: WO
Inventors: 克智塚原; 祐馬福澤
Original assignee: セイコーエプソン株式会社
Priority date: 2016-12-22
Filing date: 2017-12-06
Publication date: 2018-06-28

Abstract

The present invention efficiently circulates a liquid in the vicinity of a nozzle. This liquid ejection head is provided with: a flow path formation part including a nozzle plate to which a first nozzle and a second nozzle are provided, a first pressure chamber and a second pressure chamber to which a liquid is supplied, a first connection path which connects the first nozzle and the first pressure chamber to each other, a second connection path which connects the second nozzle and the second pressure chamber to each other, and a circulation liquid chamber which is located between the first connection path and the second connection path; and a pressure generation part which causes a pressure change in each of the first pressure chamber and the second pressure chamber, wherein the nozzle plate includes a first circulation path which connects the first connection path and the circulation liquid chamber to each other, and a second circulation path which connects the second connection path and the circulation liquid chamber to each other.

Description

Liquid jet head and liquid jet apparatus

The present invention relates to a technique for ejecting a liquid such as ink.

Conventionally, a liquid jet head has been proposed in which liquid such as ink is jetted from a plurality of nozzles. For example, Patent Document 1 discloses a liquid jet head having a laminated structure in which a flow path forming substrate is installed on the surface on one side of a communication plate and a nozzle plate is installed on the surface on the other side. In the flow path forming substrate, a pressure generating chamber filled with the liquid supplied from the common liquid chamber (reservoir) is formed, and a nozzle is formed in the nozzle plate. The pressure generating chamber and the nozzle communicate with each other through the communication passage formed in the communication plate. On the surface of the communication plate on which the nozzle plate is installed, a circulation flow passage communicating with the common liquid chamber and a groove-like circulation communication passage communicating the communication passage with the circulation flow passage are formed. According to the above configuration, it is possible to circulate the liquid inside the communication passage to the common liquid chamber through the circulation communication passage and the circulation passage.

JP, 2012-143948, A

In the technique of Patent Document 1, a circulation communication passage is formed on the surface of the communication plate to which the nozzle plate is joined. In the above configuration, it is practically difficult to efficiently circulate the liquid located in the vicinity of the nozzle with respect to the circulation channel. In consideration of the above circumstances, a preferred embodiment of the present invention has an object to efficiently circulate the liquid in the vicinity of the nozzle.

<Aspect 1>
In order to solve the above problems, a liquid jet head according to a preferred aspect (aspect 1) of the present invention includes a nozzle plate provided with a first nozzle and a second nozzle, and a first pressure chamber to which liquid is supplied. And a second communication passage connecting the first nozzle and the first pressure chamber, a second communication passage connecting the second nozzle and the second pressure chamber, and A flow passage forming portion provided with a circulating fluid chamber positioned between a communication passage and the second communication passage, and a pressure generation unit generating pressure change in each of the first pressure chamber and the second pressure chamber A first circulation passage connecting the first communication passage and the circulating fluid chamber, and a second circulation passage connecting the second communication passage and the circulating fluid chamber. Is provided. According to the above aspect, since the first circulation passage connecting the first communication passage and the circulating fluid chamber is formed in the nozzle plate, the configuration of Patent Document 1 in which the circulation communication passage is formed in the communication plate is compared. Thus, it is possible to efficiently supply the liquid in the vicinity of the nozzle to the circulating liquid chamber. Further, since the first circulation passage and the second circulation passage are commonly communicated with the circulation fluid chamber positioned between the first communication passage and the second communication passage, the circulation fluid chamber and the first communication passage are communicated with each other. There is also an advantage that the configuration of the liquid jet head is simplified as compared with the configuration in which the circulating fluid chamber communicating with the two circulation paths is separately provided. In the following description, of the liquid flowing through the first communication passage, the amount of the liquid flowing into the circulating fluid chamber through the first circulation passage is referred to as the “circulation amount”, and the liquid flowing through the first communication passage The amount of the liquid jetted through the first nozzle is expressed as “jetting amount”.
<Aspect 2>
In the preferable example (aspect 2) of aspect 1, the first nozzle has a first section and a second section having a larger diameter than the first section and located on the flow path forming portion side with respect to the first section. And. In the above aspect, since the first nozzle includes the first section and the second section having different inner diameters, there is an advantage that the flow path resistance of the first nozzle can be easily set to a desired characteristic.
<Aspect 3>
In the preferable example (aspect 3) of aspect 2, the said 1st circuit is the same depth as the said 2nd area. In the above aspect, since the first circulation path and the second section of the first nozzle have the same depth, the first circulation is compared with a configuration in which the depths of the first circulation path and the second section are different. There is an advantage that it is easy to form the road and the second section.
<Aspect 4>
In a preferred example of the second aspect (Aspect 4), the first circulation path is deeper than the second section. In the above aspect, since the first circulation passage is deeper than the second section of the first nozzle, the flow resistance of the first circulation passage is smaller compared to the configuration in which the first circulation passage is shallower than the second section. Therefore, it is possible to increase the amount of circulation as compared with the configuration in which the first circulation passage is shallower than the second section.
<Aspect 5>
In the preferable example (aspect 5) of aspect 2, the said 1st circuit is shallower than the said 2nd area. In the above aspect, since the first circulation passage is shallower than the second section of the first nozzle, the flow resistance of the first circulation passage is larger compared to the configuration in which the first circulation passage is deeper than the second section. Therefore, it is possible to increase the injection amount as compared with the configuration in which the first circulation path is deeper than the second section.
<Aspect 6>
In the preferred embodiment (Aspect 6) according to any one of Aspects 2 to 5, the second section is continuous with the first circulation path. In the above aspect, the second section of the first nozzle and the first circulation path are continuous. Therefore, the above-mentioned effect that the liquid in the vicinity of the nozzle can be efficiently circulated to the circulating liquid chamber is particularly remarkable.
<Aspect 7>
In the preferred embodiment (Aspect 7) according to any of Aspects 1 to 5, the first nozzle and the first circulation path are mutually separated in the plane of the nozzle plate. In the above aspect, the first nozzle and the first circulation path are separated from each other. Therefore, there is an advantage that it is easy to achieve both of securing the circulation amount and securing the injection amount.
<Aspect 8>
In the preferable example (aspect 8) of the aspect 7, the flow path length La of the portion of the first circulation path overlapping the circulating fluid chamber and the flow path of the portion overlapping the first communication path of the first circulation path The length Lb satisfies La> Lb. According to the above aspect, there is an advantage that the liquid in the first communication passage is easily supplied to the circulating fluid chamber via the first circulation passage.
<Aspect 9>
In the preferable example (aspect 9) of aspect 8, the flow path length Lc of the portion of the first circulation path overlapping the partition portion between the first communication passage and the circulating fluid chamber in the flow passage forming portion is the channel length Lc , La>Lb> Lc is satisfied. According to the above aspect, there is an advantage that the liquid in the first communication passage is easily supplied to the circulating fluid chamber via the first circulation passage.
<Aspect 10>
In the preferable example (aspect 10) of the aspect 6 or the aspect 7, the flow path length La of a portion overlapping the circulating fluid chamber in the first circulation path, and the flow path forming portion in the flow path formation portion of the first circulation path The flow path length Lc of the portion overlapping the partition wall portion between the first communication path and the circulating fluid chamber satisfies La> Lc. According to the above aspect, there is an advantage that the liquid in the first communication passage is easily supplied to the circulating fluid chamber via the first circulation passage.
<Aspect 11>
In the preferred embodiment (embodiment 11) according to any of embodiments 1 to 10, the flow passage width of the first circulation passage is smaller than the maximum diameter of the first nozzle. In the above aspect, since the flow passage width of the first circulation passage is smaller than the maximum diameter of the first nozzle, the flow passage width of the first circulation passage is larger than the maximum diameter of the first nozzle. (1) The flow path resistance of the circulation path is large. Therefore, it is possible to increase the injection amount.
<Aspect 12>
In the preferred embodiment (embodiment 12) according to any one of embodiments 1 to 11, the channel width of the first circulation channel is smaller than the channel width of the first pressure chamber. In the above aspect, since the flow passage width of the first circulation passage is smaller than the flow passage width of the first pressure chamber, the flow passage width of the first circulation passage is compared with the configuration larger than the flow passage width of the first pressure chamber The flow resistance of the first circulation path is large. Therefore, it is possible to increase the injection amount.
<Aspect 13>
In the preferred embodiment (embodiment 13) according to any one of embodiments 1 to 12, the channel width of the portion on the circulating fluid chamber side of the first circulation channel is greater than the channel width of the portion on the first nozzle side wide. In the above aspect, since the flow passage width of the portion on the circulating fluid chamber side of the first circulation passage is wider than the flow passage width of the portion on the first nozzle side, the liquid in the first communication passage runs the first circulation passage. It is easy to be supplied to the circulating fluid chamber via Therefore, there is an advantage that it is easy to secure the amount of circulation.
<Aspect 14>
In the preferable example (Aspect 14) according to any one of Aspects 1 to 12, the flow path width of the middle portion of the first circulation path is the flow path width of the portion on the circulating fluid chamber side as viewed from the middle portion It is narrower than the channel width of the portion on the first nozzle side. In the above aspect, the flow passage width of the first circulation passage is constant because the flow passage width of the middle portion of the first circulation passage is narrower than the circulation liquid chamber side and the first nozzle side. In comparison, the flow path resistance of the first circulation path is large. Therefore, it is possible to increase the injection amount.
<Aspect 15>
In the preferred embodiment (embodiment 15) according to any one of embodiments 1 to 12, the channel width of the middle portion of the first circulation channel is the channel width of the portion on the circulating fluid chamber side as viewed from the middle portion and the channel width It is wider than the flow passage width of the portion on the first nozzle side. In the above aspect, the flow passage width of the first circulation passage is constant because the flow passage width of the middle part of the first circulation passage is wider than the circulation liquid chamber side and the first nozzle side. In comparison, the flow resistance of the first circulation path is small. Therefore, it is possible to increase the amount of circulation.
<Aspect 16>
In the preferred embodiment (Aspect 16) according to any one of Aspects 1 to 15, the central axis of the first nozzle is located on the opposite side of the circulating fluid chamber with respect to the central axis of the first communication passage. In the above aspect, since the central axis of the first nozzle is located on the opposite side to the circulating fluid chamber when viewed from the central axis of the first communication passage, the central axis of the first nozzle is circulated when viewed from the central axis of the first communication passage. Compared with the configuration located on the liquid chamber side, it is possible to reduce the circulation amount and to increase the injection amount.
<Aspect 17>
In a preferred embodiment (aspect 17) according to any one of the aspects 1 to 15, the central axis of the first nozzle is at the same position as the central axis of the first communication passage. In the above aspect, since the central axis of the first nozzle and the central axis of the first communication passage are at the same position, the central axis of the first nozzle and the central axis of the first communication passage are at different positions. In comparison, there is an advantage that it is easy to achieve both securing of the injection amount and securing of the circulating amount.
<Aspect 18>
In the preferable example (Aspect 18) in any one of Aspects 1 to 15, the central axis of the first nozzle is located on the circulating fluid chamber side as viewed from the central axis of the first communication passage. In the above aspect, since the central axis of the first nozzle is located on the circulating fluid chamber side as viewed from the central axis of the first communication passage, the central axis of the first nozzle is the circulating fluid chamber as viewed from the central axis of the first communication passage. It is possible to increase the amount of circulation and to reduce the amount of injection compared to the configuration on the opposite side.
<Aspect 19>
In the preferable example (Aspect 19) according to any one of Aspects 1 to 18, an intermediate portion of the first circulation path is closer to the circulating fluid chamber side and the portion on the first nozzle side as viewed from the intermediate portion. deep. In the above aspect, since the middle portion of the first circulation path is deeper than the portion on the circulating fluid chamber side and the portion on the first nozzle side, the first circulation path has a constant depth over the entire length as compared to the configuration 1 The flow path resistance of the circulation path is small. Therefore, it is possible to increase the amount of circulation.
<Aspect 20>
In a preferred embodiment (aspect 20) according to any one of the aspects 1 to 19, when a pressure change is generated in the first pressure chamber, the amount of liquid supplied to the circulating fluid chamber through the first circulation path. Is larger than the amount of liquid ejected from the first nozzle. In the above aspect, the circulation amount is larger than the injection amount. That is, it is possible to effectively circulate the liquid in the vicinity of the nozzle to the circulating liquid chamber while securing the injection amount.
<Aspect 21>
In the preferable example (Aspect 21) according to any one of Aspects 1 to 20, the first circulation path and the circulating fluid chamber overlap each other, and the first circulation path and the first pressure chamber overlap each other, The circulating fluid chamber and the first pressure chamber do not overlap with each other. In the above aspect, while the first circulation passage overlaps the circulating fluid chamber and the first pressure chamber, the circulating fluid chamber and the first pressure chamber do not overlap with each other. Therefore, there is an advantage that the liquid jet head can be easily miniaturized as compared with, for example, a configuration in which the first circulation passage and the first pressure chamber do not overlap with each other.
<Aspect 22>
In the preferable example (Aspect 22) according to any one of Aspects 1 to 20, the first circulation path and the circulating fluid chamber overlap each other, and the first circulation path and the pressure generating portion overlap each other, The circulating fluid chamber and the pressure generator do not overlap with each other. In the above aspect, while the first circulation passage overlaps the circulating fluid chamber and the pressure generating portion, the circulating fluid chamber and the pressure generating portion do not overlap each other. Therefore, there is an advantage that the liquid jet head can be easily miniaturized as compared with, for example, a configuration in which the first circulation path and the pressure generating unit do not overlap with each other.
<Aspect 23>
In the preferable example (Aspect 23) according to any one of Aspects 1 to 20, the end face of the first pressure chamber on the side of the first communication passage is an inclined surface inclined with respect to the upper surface of the first pressure chamber The first circuit and the upper surface of the first pressure chamber do not overlap with each other.
<Aspect 24>
In the preferable example (Aspect 24) according to any one of Aspects 1 to 23, the first pressure chamber and the circulating fluid chamber communicate with each other through the first communication passage and the first circulation passage. In the above aspect, the first pressure chamber and the circulating fluid chamber are in articulated communication via the first communication passage and the first circulation passage. Therefore, compared with the configuration in which the first pressure chamber and the circulating fluid chamber are in direct communication, it is possible to supply the liquid to the circulating fluid chamber while appropriately securing the injection amount.
<Aspect 25>
In the preferable embodiment (embodiment 25) according to any one of the embodiments 1 to 24, each of the nozzle plate and the flow path forming portion includes a substrate formed of silicon. In the above aspect, since each of the nozzle plate and the flow path forming portion includes the silicon substrate, the flow path can be formed with high accuracy for the nozzle plate and the flow path forming portion by using, for example, a semiconductor manufacturing technology It has the advantage of
<Aspect 26>
In the preferred embodiment (Aspect 26) according to any one of Aspects 1 to 25, the nozzle plate is provided with a common circuit that is continuous with the first circuit and the second circuit. In the above aspect, since the common circulation path continuous to the first circulation path and the second circulation path is formed in the nozzle plate, the flow path area of the liquid is increased as compared with the configuration in which the common circulation path is not formed. Is possible.
<Aspect 27>
A liquid ejecting apparatus according to a preferred aspect of the present invention includes the liquid ejecting head according to each aspect exemplified above. A good example of the liquid ejecting apparatus is a printing apparatus that ejects ink, but the application of the liquid ejecting apparatus according to the present invention is not limited to printing.

It is a block diagram of the liquid injection device in 1st Embodiment of this invention. FIG. 2 is a cross-sectional view of a liquid jet head. FIG. 2 is a partial exploded perspective view of a liquid jet head. It is sectional drawing of a piezoelectric element. FIG. 6 is an explanatory view of circulation of ink in the liquid jet head. FIG. 7A is a plan view and a cross-sectional view of the vicinity of the circulating fluid chamber in the liquid jet head. FIG. 7 is a partial exploded perspective view of a liquid jet head according to a second embodiment. It is the top view and sectional drawing of the vicinity of the circulating fluid chamber in 2nd Embodiment. It is the top view and sectional drawing of the vicinity of the circulating fluid chamber in 3rd Embodiment. FIG. 13 is a cross-sectional view of the vicinity of a circulating fluid chamber in a liquid jet head of a modified example. FIG. 13 is a cross-sectional view of the vicinity of a circulating fluid chamber in a liquid jet head of a modified example. FIG. 13 is a cross-sectional view of the vicinity of a circulating fluid chamber in a liquid jet head of a modified example. FIG. 14 is a plan view of the vicinity of a circulating fluid chamber in a liquid jet head of a modified example. FIG. 14 is a plan view of the vicinity of a circulating fluid chamber in a liquid jet head of a modified example. FIG. 14 is a plan view of the vicinity of a circulating fluid chamber in a liquid jet head of a modified example. FIG. 14 is a plan view and a cross-sectional view of the vicinity of the circulating fluid chamber in the liquid jet head of the modified example. FIG. 14 is a plan view and a cross-sectional view of the vicinity of the circulating fluid chamber in the liquid jet head of the modified example. FIG. 13 is a cross-sectional view of the vicinity of a circulating fluid chamber in a liquid jet head of a modified example. FIG. 13 is a cross-sectional view of the vicinity of a circulating fluid chamber in a liquid jet head of a modified example. FIG. 13 is a plan view and a cross-sectional view of the vicinity of a circulating fluid chamber in a liquid jet head of a modified example.

First Embodiment
FIG. 1 is a configuration diagram illustrating a liquid ejecting apparatus 100 according to a first embodiment of the present invention. The liquid ejecting apparatus 100 according to the first embodiment is an ink jet printing apparatus that ejects an ink, which is an example of a liquid, to the medium 12. The medium 12 is typically a printing paper, but a print target of any material such as a resin film or fabric may be used as the medium 12. As illustrated in FIG. 1, the liquid ejecting apparatus 100 is provided with a liquid container 14 storing ink. For example, a cartridge removable from the liquid ejecting apparatus 100, a bag-like ink pack formed of a flexible film, or an ink tank capable of refilling ink is used as the liquid container 14. A plurality of types of ink having different colors are stored in the liquid container 14.

As illustrated in FIG. 1, the liquid ejecting apparatus 100 includes a control unit 20, a transport mechanism 22, a moving mechanism 24, and a liquid ejecting head 26. The control unit 20 includes, for example, a processing circuit such as a central processing unit (CPU) or a field programmable gate array (FPGA) and a storage circuit such as a semiconductor memory, and centrally controls each element of the liquid ejecting apparatus 100. The transport mechanism 22 transports the medium 12 in the Y direction under the control of the control unit 20.

The moving mechanism 24 reciprocates the liquid jet head 26 in the X direction under the control of the control unit 20. The X direction is a direction intersecting (typically orthogonal) to the Y direction in which the medium 12 is transported. The moving mechanism 24 according to the first embodiment includes a substantially box-shaped transport body 242 (carriage) accommodating the liquid jet head 26 and a transport belt 244 to which the transport body 242 is fixed. A configuration in which the plurality of liquid jet heads 26 are mounted on the transport body 242 or a configuration in which the liquid container 14 is mounted on the transport body 242 together with the liquid jet heads 26 may be adopted.

The liquid jet head 26 jets the ink supplied from the liquid container 14 from the plurality of nozzles N (jet holes) to the medium 12 under the control of the control unit 20. A desired image is formed on the surface of the medium 12 by the ink jetted onto the medium 12 by each liquid jet head 26 in parallel with the conveyance of the medium 12 by the conveyance mechanism 22 and the repetitive reciprocation of the conveyance body 242. . The direction perpendicular to the XY plane (for example, a plane parallel to the surface of the medium 12) is hereinafter referred to as the Z direction. The jetting direction (typically, the vertical direction) of the ink by each liquid jet head 26 corresponds to the Z direction.

As illustrated in FIG. 1, the plurality of nozzles N of the liquid jet head 26 are arranged in the Y direction. The plurality of nozzles N in the first embodiment are divided into a first row L1 and a second row L2 arranged in parallel at intervals in the X direction. Each of the first row L1 and the second row L2 is a set of a plurality of nozzles N linearly arranged in the Y direction. Although it is possible to make the positions of the nozzles N different in the Y direction between the first row L1 and the second row L2 (that is, staggered or staggered), the first row L1 and the second row L2 are also possible. The configuration in which the positions of the nozzles N in the Y direction are made to coincide with each other will be exemplified below for convenience. In the liquid jet head 26, a plane (YZ plane) O which passes through a central axis parallel to the Y direction and is parallel to the Z direction will be referred to as a "central plane" in the following description.

FIG. 2 is a cross-sectional view of the liquid jet head 26 in a cross section perpendicular to the Y direction, and FIG. 3 is a partial exploded perspective view of the liquid jet head 26. As can be understood from FIGS. 2 and 3, the liquid jet head 26 according to the first embodiment includes an element associated with each nozzle N of the first row L1 (exemplary first nozzle) and each nozzle N of the second row L2. An element related to (an example of the second nozzle) is a structure in which the elements are arranged in plane symmetry with respect to the central plane O. That is, a portion (hereinafter referred to as a “first portion”) P1 on the positive side in the X direction across the central plane O of the liquid jet head 26 and a portion P2 on the negative side (hereinafter referred to as “second portion”) in the X direction. The structure is substantially common. The plurality of nozzles N in the first row L1 are formed in the first portion P1, and the plurality of nozzles N in the second row L2 are formed in the second portion P2. The center plane O corresponds to the interface between the first portion P1 and the second portion P2.

As illustrated in FIGS. 2 and 3, the liquid jet head 26 includes a flow path forming unit 30. The flow path forming unit 30 is a structure forming a flow path for supplying the ink to the plurality of nozzles N. The flow path forming unit 30 according to the first embodiment is configured by stacking the first flow path substrate 32 (communication plate) and the second flow path substrate 34 (pressure chamber formation plate). Each of the first flow path substrate 32 and the second flow path substrate 34 is a plate-like member elongated in the Y direction. The second flow path substrate 34 is installed on the surface Fa on the negative side in the Z direction of the first flow path substrate 32 using, for example, an adhesive.

As illustrated in FIG. 2, on the surface Fa of the first flow path substrate 32, in addition to the second flow path substrate 34, the vibration portion 42, the plurality of piezoelectric elements 44, the protective member 46, and the housing portion 48 are included. And (not shown in FIG. 3). On the other hand, the nozzle plate 52 and the vibration absorber 54 are disposed on the surface Fb of the first flow path substrate 32 on the positive side in the Z direction (ie, the side opposite to the surface Fa). The respective elements of the liquid jet head 26 are generally plate-like members elongated in the Y direction similarly to the first flow path substrate 32 and the second flow path substrate 34, and for example, mutually using an adhesive agent It is joined. The direction in which the first flow path substrate 32 and the second flow path substrate 34 are stacked, or the direction in which the first flow path substrate 32 and the nozzle plate 52 are stacked (or the direction perpendicular to the surface of each plate-like element) It is also possible to grasp it as a Z direction.

The nozzle plate 52 is a plate-like member in which a plurality of nozzles N are formed, and is installed on the surface Fb of the first flow path substrate 32 using, for example, an adhesive. Each of the plurality of nozzles N is a circular through hole through which the ink passes. In the nozzle plate 52 of the first embodiment, a plurality of nozzles N constituting a first row L1 and a plurality of nozzles N constituting a second row L2 are formed. Specifically, a plurality of nozzles N in the first row L1 are formed along the Y direction in the region on the positive side in the X direction with respect to the central plane O of the nozzle plate 52, and in the region on the negative side in the X direction. The plurality of nozzles N in the second row L2 are formed along the Y direction. The nozzle plate 52 of the first embodiment is a single plate-like member that is continuous over a portion in which the plurality of nozzles N in the first row L1 is formed and a portion in which the plurality of nozzles N in the second row L2 is formed. . The nozzle plate 52 of the first embodiment is manufactured by processing a silicon (Si) single crystal substrate using semiconductor manufacturing technology (for example, processing technology such as dry etching or wet etching). However, known materials and manufacturing methods can be arbitrarily adopted for manufacturing the nozzle plate 52.

As illustrated in FIGS. 2 and 3, in the first flow path substrate 32, the space Ra, the plurality of supply paths 61, and the plurality of communication paths 63 are formed for each of the first portion P1 and the second portion P2. Be done. The space Ra is an opening formed in a long shape along the Y direction in plan view (that is, viewed from the Z direction), and the supply passage 61 and the communication passage 63 are through holes formed for each nozzle N. The plurality of communication paths 63 are arranged in the Y direction in plan view, and the plurality of supply paths 61 are arranged in the Y direction between the arrangement of the plurality of communication paths 63 and the space Ra. The plurality of supply paths 61 commonly communicate with the space Ra. In addition, any one communication passage 63 overlaps the nozzle N corresponding to the communication passage 63 in a plan view. Specifically, any one communication passage 63 of the first portion P1 communicates with one nozzle N corresponding to the communication passage 63 in the first row L1. Similarly, any one communication passage 63 of the second portion P2 communicates with one nozzle N corresponding to the communication passage 63 in the second row L2.

As illustrated in FIGS. 2 and 3, the second flow path substrate 34 is a plate-like member in which a plurality of pressure chambers C are formed for each of the first portion P1 and the second portion P2. The plurality of pressure chambers C are arranged in the Y direction. Each pressure chamber C (cavity) is a long space formed for each nozzle N and extending in the X direction in plan view. The first flow path substrate 32 and the second flow path substrate 34 are manufactured by processing a single crystal silicon substrate using, for example, a semiconductor manufacturing technology, as in the case of the nozzle plate 52 described above. However, known materials and manufacturing methods may be arbitrarily adopted for manufacturing the first flow path substrate 32 and the second flow path substrate 34. As described above, the flow path forming portion 30 (the first flow path substrate 32 and the second flow path substrate 34) and the nozzle plate 52 in the first embodiment include a substrate formed of silicon. Therefore, there is an advantage that fine flow paths can be formed in the flow path forming portion 30 and the nozzle plate 52 with high accuracy by utilizing the semiconductor manufacturing technology as exemplified in the above-mentioned example, for example.

As illustrated in FIG. 2, a vibrating portion 42 is provided on the surface of the second flow path substrate 34 opposite to the first flow path substrate 32. The vibrating portion 42 of the first embodiment is a plate-like member (diaphragm) that can elastically vibrate. The second flow path substrate 34 and the vibrating portion 42 are integrally formed by selectively removing a part in the thickness direction of a region corresponding to the pressure chamber C in the plate-like member having a predetermined thickness. It is also possible.

As understood from FIG. 2, the surface Fa of the first flow path substrate 32 and the vibrating portion 42 oppose each other at an interval inside the pressure chambers C. The pressure chamber C is a space located between the surface Fa of the first flow path substrate 32 and the vibrating portion 42, and generates pressure change in the ink filled in the space. Each pressure chamber C is a space whose longitudinal direction is, for example, the X direction, and is formed individually for each nozzle N. A plurality of pressure chambers C are arranged in the Y direction for each of the first row L1 and the second row L2. As illustrated in FIG. 2 and FIG. 3, the end on the central plane O side of any one pressure chamber C overlaps the communication passage 63 in plan view, and the end on the opposite side to the central plane O is a flat It overlaps with the supply path 61 visually. Therefore, in each of the first portion P1 and the second portion P2, the pressure chamber C communicates with the nozzle N through the communication passage 63, and communicates with the space Ra through the supply passage 61. In addition, it is also possible to add predetermined | prescribed flow path resistance by forming the throttling flow path by which the flow path width was narrowed in the pressure chamber C. FIG.

As illustrated in FIG. 2, a plurality of piezoelectric elements corresponding to different nozzles N for each of the first portion P1 and the second portion P2 on the surface of the vibrating portion 42 opposite to the pressure chamber C. 44 are installed. The piezoelectric element 44 is a passive element that is deformed by the supply of a drive signal. The plurality of piezoelectric elements 44 are arranged in the Y direction so as to correspond to the pressure chambers C. The optional one piezoelectric element 44 is a laminate in which a piezoelectric layer 443 is interposed between the first electrode 441 and the second electrode 442 facing each other, as illustrated in FIG. 4. Note that one of the first electrode 441 and the second electrode 442 may be an electrode continuous across the plurality of piezoelectric elements 44 (that is, a common electrode). A portion where the first electrode 441, the second electrode 442, and the piezoelectric layer 443 overlap in a plan view functions as the piezoelectric element 44. It is also possible to define a portion that is deformed by the supply of the drive signal (that is, an active portion that vibrates the vibrating portion 42) as the piezoelectric element 44. As understood from the above description, the liquid jet head 26 according to the first embodiment includes the first piezoelectric element and the second piezoelectric element. For example, the first piezoelectric element is the piezoelectric element 44 on one side (for example, the right side in FIG. 2) of the central plane O in the X direction, and the second piezoelectric element is the other side of the central axis O in the X direction (for example, It is the piezoelectric element 44 of the left side in FIG. When the vibration unit 42 vibrates in conjunction with the deformation of the piezoelectric element 44, the pressure in the pressure chamber C fluctuates, and the ink filled in the pressure chamber C is ejected through the communication passage 63 and the nozzle N. Ru.

The protective member 46 in FIG. 2 is a plate-like member for protecting the plurality of piezoelectric elements 44, and is disposed on the surface of the vibrating portion 42 (or the surface of the second flow path substrate 34). Although the material and manufacturing method of the protection member 46 are arbitrary, the protection member is obtained by processing the single crystal substrate of silicon (Si), for example, by the semiconductor manufacturing technology, like the first flow path substrate 32 and the second flow path substrate 34. 46 may be formed. The plurality of piezoelectric elements 44 are accommodated in the recess formed on the surface of the protective member 46 on the side of the vibrating portion 42.

The end of the wiring board 28 is bonded to the surface of the vibrating portion 42 opposite to the flow path forming portion 30 (or the surface of the flow path forming portion 30). The wiring substrate 28 is a flexible mounting component on which a plurality of wires (not shown) for electrically connecting the control unit 20 and the liquid jet head 26 are formed. An end portion of the wiring substrate 28 which passes through the opening formed in the protective member 46 and the opening formed in the housing 48 and is extended to the outside is connected to the control unit 20. For example, a flexible wiring substrate 28 such as a flexible printed circuit (FPC) or a flexible flat cable (FFC) is preferably employed.

The housing portion 48 is a case for storing the ink supplied to the plurality of pressure chambers C (and further, the plurality of nozzles N). The surface of the housing portion 48 on the positive side in the Z direction is bonded to the surface Fa of the first flow path substrate 32 with, for example, an adhesive. A well-known technique and manufacturing method can be arbitrarily employ | adopted for manufacture of the housing | casing part 48. FIG. For example, the housing 48 can be formed by injection molding of a resin material.

As illustrated in FIG. 2, in the housing unit 48 of the first embodiment, a space Rb is formed for each of the first portion P1 and the second portion P2. The section Rb of the housing portion 48 and the space Ra of the first flow path substrate 32 communicate with each other. A space configured by the space Ra and the space Rb functions as a liquid storage chamber (reservoir) R that stores the ink supplied to the plurality of pressure chambers C. The liquid storage chamber R is a common liquid chamber shared by the plurality of nozzles N. A liquid storage chamber R is formed in each of the first portion P1 and the second portion P2. The liquid storage chamber R of the first portion P1 is located on the positive side in the X direction with respect to the center plane O, and the liquid storage chamber R for the second portion P2 is located on the negative side with respect to the X direction as viewed from the central surface O. An inlet port 482 for introducing the ink supplied from the liquid container 14 into the liquid storage chamber R is formed on the surface of the housing 48 opposite to the first flow path substrate 32.

As illustrated in FIG. 2, vibration absorbers 54 are provided on the surface Fb of the first flow path substrate 32 for each of the first portion P1 and the second portion P2. The vibration absorbing body 54 is a flexible film (compliance substrate) that absorbs pressure fluctuations of the ink in the liquid storage chamber R. As illustrated in FIG. 3, the vibration absorber 54 is installed on the surface Fb of the first flow path substrate 32 so as to close the space Ra of the first flow path substrate 32 and the plurality of supply paths 61, and the liquid storage chamber The wall of R (specifically, the bottom) is configured.

As illustrated in FIG. 2, a space (hereinafter referred to as a “circulating liquid chamber”) 65 is formed on the surface Fb of the first flow path substrate 32 facing the nozzle plate 52. The circulating fluid chamber 65 of the first embodiment fluid is a long-long bottomed hole (groove) extending in the Y direction in plan view. The opening of the circulating fluid chamber 65 is closed by the nozzle plate 52 bonded to the surface Fb of the first flow path substrate 32.

FIG. 5 is a block diagram of the liquid jet head 26 focusing on the circulating liquid chamber 65. As illustrated in FIG. 5, the circulating fluid chamber 65 is continuous across the plurality of nozzles N along the first row L1 and the second row L2. Specifically, the circulating fluid chamber 65 is formed between the arrangement of the plurality of nozzles N in the first row L1 and the arrangement of the plurality of nozzles N in the second row L2. Therefore, as illustrated in FIG. 2, the circulating fluid chamber 65 is located between the communication passage 63 of the first portion P1 and the communication passage 63 of the second portion P2. As understood from the above description, the flow passage forming portion 30 of the first embodiment includes the pressure chamber C (first pressure chamber) and the communication passage 63 (first communication passage) in the first portion P1, and the second portion Circulating fluid chamber 65 located between pressure chamber C (second pressure chamber) and communication passage 63 (second communication passage) at P2, and communication passage 63 of first portion P1 and communication passage 63 of second portion P2. And are formed structures. As illustrated in FIG. 2, the flow path forming unit 30 according to the first embodiment includes a wall-shaped portion (hereinafter, referred to as “partition”) 69 that divides between the circulating fluid chamber 65 and each communication passage 63.

As described above, the plurality of pressure chambers C and the plurality of piezoelectric elements 44 are arranged in the Y direction in each of the first portion P1 and the second portion P2. Therefore, it is also possible that the circulating fluid chamber 65 extends in the Y direction so as to be continuous across the plurality of pressure chambers C or the plurality of piezoelectric elements 44 in each of the first portion P1 and the second portion P2. Further, as can be understood from FIGS. 2 and 3, the circulating fluid chamber 65 and the liquid storage chamber R extend in the Y direction at an interval from each other, and within the interval, the pressure chamber C, the communication passage 63 and the nozzle It is also possible that N is located.

FIG. 6 is an enlarged plan view and a cross-sectional view of a portion of the liquid jet head 26 in the vicinity of the circulating liquid chamber 65. As illustrated in FIG. 6, one nozzle N in the first embodiment includes a first section n1 and a second section n2. The first section n1 and the second section n2 are circular spaces formed coaxially and in communication with each other. The second section n2 is located on the flow path forming portion 30 side as viewed from the first section n1. The inner diameter d2 of the second section n2 is larger than the inner diameter d1 of the first section n1 (d2> d1). As described above, according to the configuration in which each nozzle N is formed in a step shape, there is an advantage that the flow path resistance of each nozzle N can be easily set to a desired characteristic. Further, as illustrated in FIG. 6, the central axis Qa of each nozzle N in the first embodiment is located on the opposite side of the circulating fluid chamber 65 as viewed from the central axis Qb of the communication passage 63.

As illustrated in FIG. 6, a plurality of circulation paths 72 are formed on each of the first portion P1 and the second portion P2 on the surface of the nozzle plate 52 facing the flow path forming portion 30. The plurality of circulation paths 72 (example of the first circulation path) of the first portion P1 correspond to the plurality of nozzles N (or the plurality of communication paths 63 corresponding to the first line L1) of the first row L1 one to one. Do. Further, the plurality of circulation paths 72 (example of the second circulation path) of the second portion P2 is in one-to-one correspondence with the plurality of nozzles N in the second row L2 (or the plurality of communication passages 63 corresponding to the second row L2). Corresponds to

Each circulation path 72 is a groove (that is, a long bottomed hole) extending in the X direction, and functions as a flow path through which the ink flows. The circulation passage 72 in the first embodiment is formed at a position separated from the nozzle N (specifically, on the side of the circulating fluid chamber 65 as viewed from the nozzle N corresponding to the circulation passage 72). For example, the plurality of nozzles N (particularly, the second section n2) and the plurality of circulation paths 72 are collectively formed in a common step by semiconductor manufacturing technology (for example, processing technology such as dry etching or wet etching).

As illustrated in FIG. 6, each circulation path 72 is formed in a straight line with a flow passage width Wa equivalent to the inner diameter d2 of the second section n2 of the nozzle N. Further, the flow passage width (dimension in the Y direction) Wa of the circulation passage 72 in the first embodiment is smaller than the flow passage width (dimension in the Y direction) Wb of the pressure chamber C. Therefore, as compared with a configuration in which the flow passage width Wa of the circulation passage 72 is larger than the flow passage width Wb of the pressure chamber C, it is possible to increase the flow passage resistance of the circulation passage 72. On the other hand, the depth Da of the circulation path 72 with respect to the surface of the nozzle plate 52 is constant over the entire length. Specifically, each circulation path 72 is formed to the same depth as the second section n2 of the nozzle N. According to the above configuration, there is an advantage that it is easy to form the circulation passage 72 and the second section n2 as compared with the configuration in which the circulation path 72 and the second section n2 are formed in different depths. The “depth” of the flow path means the depth of the flow path in the Z direction (for example, the height difference between the formation surface of the flow path and the bottom surface of the flow path).

One arbitrary circulation path 72 in the first portion P1 is located on the side of the circulating fluid chamber 65 as viewed from the nozzle N corresponding to the circulation path 72 in the first row L1. Further, any one circulation passage 72 in the second portion P2 is located on the side of the circulating fluid chamber 65 as viewed from the nozzle N corresponding to the circulation passage 72 in the second row L2. The end of each circulation passage 72 on the opposite side (the communication passage 63 side) from the center plane O overlaps one communication passage 63 corresponding to the circulation passage 72 in a plan view. That is, the circulation passage 72 communicates with the communication passage 63. On the other hand, an end of the circulation path 72 on the side of the center plane O (on the side of the circulating fluid chamber 65) overlaps the circulating fluid chamber 65 in plan view. That is, the circulation path 72 communicates with the circulating fluid chamber 65. As understood from the above description, each of the plurality of communication paths 63 communicates with the circulating fluid chamber 65 via the circulation path 72. Therefore, the ink in each communication passage 63 is supplied to the circulating fluid chamber 65 through the circulation passage 72 as illustrated by a broken arrow in FIG. That is, in the first embodiment, the plurality of communication passages 63 corresponding to the first row L1 and the plurality of communication passages 63 corresponding to the second row L2 communicate with one circulating fluid chamber 65 in common.

In FIG. 6, the flow path length La of a portion overlapping the circulating fluid chamber 65 of any one circulation path 72 and the flow path length (dimension in the X direction) of a portion overlapping the communication path 63 of the circulation path 72 Lb and a flow path length (dimension in the X direction) Lc of a portion of the circulation path 72 overlapping the partition portion 69 of the flow path forming portion 30 are illustrated. The flow path length Lc corresponds to the thickness of the partition 69. The partition portion 69 functions as a throttling portion of the circulation passage 72. Therefore, the flow path resistance of the circulation path 72 increases as the flow path length Lc corresponding to the thickness of the partition portion 69 is longer. In the first embodiment, the flow path length La is longer than the flow path length Lb (La> Lb), and the flow path length La is longer than the flow path length Lc (La> Lc). Furthermore, in the first embodiment, the relationship that the flow path length Lb is longer than the flow path length Lc (Lb> Lc) is established (La> Lb> Lc). According to the above configuration, the ink easily flows from the communication passage 63 into the circulating liquid chamber 65 through the circulation passage 72, as compared with the configuration in which the flow passage length La and the flow passage length Lb are shorter than the flow passage length Lc. It has the advantage of

As exemplified above, in the first embodiment, the pressure chamber C indirectly communicates with the circulating fluid chamber 65 via the communication passage 63 and the circulation passage 72. That is, the pressure chamber C and the circulating fluid chamber 65 do not communicate directly. In the above configuration, when the pressure in the pressure chamber C fluctuates due to the operation of the piezoelectric element 44, a part of the ink flowing in the communication passage 63 is ejected from the nozzle N to the outside, and the remaining part is the communication passage It flows into the circulating fluid chamber 65 from 63 via the circulation passage 72. In the first embodiment, the amount of ink ejected through the nozzle N (hereinafter referred to as “ejection amount”) out of the ink flowing through the communication passage 63 by one drive of the piezoelectric element 44 corresponds to the communication passage 63. Inertances of the communication passage 63, the nozzle, and the circulation passage 72 are selected so as to exceed the amount of ink flowing into the circulating liquid chamber 65 through the circulation passage 72 (hereinafter referred to as "circulation amount") among the circulating ink. . Assuming that all the piezoelectric elements 44 are simultaneously driven, the total of the circulating amounts flowing into the circulating fluid chamber 65 from the plurality of communication passages 63 (for example, the circulating fluid chamber 65) than the total of the jetting amounts by the plurality of nozzles N It is also possible to say that the flow rate within the unit time is higher.

Specifically, of the ink flowing through the communication passage 63, the ratio of the circulation amount is 70% or more (the injection amount ratio is 30% or less). Each flow path resistance is determined. According to the above configuration, it is possible to effectively circulate the ink in the vicinity of the nozzle to the circulating liquid chamber 65 while securing the ejection amount of the ink. Generally speaking, the larger the flow path resistance of the circulation path 72, the smaller the circulation amount, while the injection amount increases, and the smaller the flow path resistance of the circulation path 72, the circulation amount increases, but the injection amount is smaller. There is a tendency to decrease.

As illustrated in FIG. 5, the liquid ejecting apparatus 100 according to the first embodiment includes a circulation mechanism 75. The circulation mechanism 75 is a mechanism for supplying (i.e., circulating) the ink in the circulation liquid chamber 65 to the liquid storage chamber R. The circulation mechanism 75 according to the first embodiment includes, for example, a suction mechanism (for example, a pump) for sucking the ink from the circulation liquid chamber 65, a filter mechanism for collecting air bubbles and foreign substances mixed in the ink, and thickening of the ink by heating. And a heating mechanism (not shown). The ink in which bubbles and foreign substances are removed by the circulation mechanism 75 and the viscosity is reduced is supplied from the circulation mechanism 75 to the liquid storage chamber R via the inlet port 482. As understood from the above description, in the first embodiment, the liquid storage chamber R → supply passage 61 → pressure chamber C → communication passage 63 → circulation passage 72 → circulating liquid chamber 65 → circulation mechanism 75 → liquid storage chamber R The ink circulates along the path.

As understood from FIG. 5, the circulation mechanism 75 of the first embodiment sucks the ink from both sides of the circulation liquid chamber 65 in the Y direction. That is, the circulation mechanism 75 sucks the ink from the vicinity of the end on the negative side in the Y direction of the circulating liquid chamber 65 and the vicinity of the end on the positive side in the Y direction of the circulating liquid chamber 65. In the configuration in which the ink is sucked from only one end of the circulating fluid chamber 65 in the Y direction, a difference occurs in the pressure of the ink between both ends of the circulating fluid chamber 65, and the pressure difference in the circulating fluid chamber 65 As a result, the pressure of the ink in the communication passage 63 may differ depending on the position in the Y direction. Therefore, the ejection characteristics (for example, the ejection amount and the ejection speed) of the ink from each nozzle may differ depending on the position in the Y direction. In contrast to the above configuration, in the first embodiment, since the ink is sucked from both sides of the circulating fluid chamber 65, the pressure difference inside the circulating fluid chamber 65 is reduced. Therefore, it is possible to approximate the ejection characteristics of the ink with high accuracy over a plurality of nozzles arranged in the Y direction. However, when the pressure difference in the Y direction in the circulating fluid chamber 65 does not pose a particular problem, a configuration in which ink is sucked from one end of the circulating fluid chamber 65 may also be employed.

As described above, the circulation passage 72 and the communication passage 63 overlap in plan view, and the communication passage 63 and the pressure chamber C overlap in plan view. Therefore, the circulation passage 72 and the pressure chamber C overlap each other in plan view. On the other hand, as understood from FIGS. 5 and 6, the circulating fluid chamber 65 and the pressure chamber C do not overlap each other in plan view. Further, since the piezoelectric element 44 is formed along the X direction over the entire pressure chamber C, the circulation path 72 and the piezoelectric element 44 overlap each other in plan view, while the circulating liquid chamber 65 and the piezoelectric element 44 They do not overlap each other in plan view. As understood from the above description, the pressure chamber C or the piezoelectric element 44 overlaps the circulation passage 72 in plan view, but does not overlap the circulating fluid chamber 65 in plan view. Therefore, as compared with a configuration in which the pressure chamber C or the piezoelectric element 44 does not overlap the circulation path 72 in plan view, for example, the liquid jet head 26 can be easily miniaturized.

As described above, in the first embodiment, the circulation passage 72 for connecting the communication passage 63 and the circulation liquid chamber 65 is formed in the nozzle plate 52. Therefore, it is possible to efficiently circulate the ink in the vicinity of the nozzle N to the circulating liquid chamber 65 as compared with the configuration of Patent Document 1 in which the circulation communication passage is formed in the communication plate. Further, in the first embodiment, the communication passage 63 corresponding to the first row L1 and the communication passage 63 corresponding to the second row L2 are in common communication with the circulating fluid chamber 65 between them. Therefore, as compared with a configuration in which the circulating fluid chamber in communication with the circulation passages 72 corresponding to the first row L1 and the circulating fluid chamber in communication with the circulation passages 72 corresponding to the second row L2 are separately provided, There is also an advantage that the configuration of the ejection head 26 is simplified (and, consequently, miniaturization is realized).

Second Embodiment
A second embodiment of the present invention will be described. In addition, about the element which an operation | movement and a function are the same as 1st Embodiment in each form illustrated below, the code | symbol used by description of 1st Embodiment is diverted and detailed description of each is abbreviate | omitted suitably.

FIG. 7 is a partial exploded perspective view of the liquid jet head 26 in the second embodiment, and corresponds to FIG. 3 referred to in the first embodiment. FIG. 8 is an enlarged plan view and a sectional view of a portion in the vicinity of the circulating fluid chamber 65 in the liquid jet head 26, and corresponds to FIG. 6 referred to in the first embodiment.

In the first embodiment, the configuration in which the circulation path 72 and the nozzle N are separated from each other is illustrated. In the second embodiment, as understood from FIGS. 7 and 8, the circulation passage 72 and the nozzle N are continuous with each other. That is, one circulation path 72 of the first portion P1 is continued to one nozzle N of the first row L1, and one circulation path 72 of the second portion P2 is one nozzle N of the second row L2. To be continuous. Specifically, as illustrated in FIG. 8, the second section n2 of each nozzle N is continuous with the circulation path 72. That is, the circulation path 72 and the second section n2 are formed to have the same depth, and the inner circumferential surface of the circulation path 72 and the inner circumferential surface of the second section n2 are continuous with each other. In other words, the nozzle N (first section n1) may be formed at the bottom of one circulation path 72 extending in the X direction. Specifically, a first section n1 of the nozzle N is formed in the vicinity of the end of the bottom surface of the circulation path 72 opposite to the central plane O. The other configuration is the same as that of the first embodiment. For example, also in the second embodiment, the flow path length La of a portion overlapping the circulating fluid chamber 65 in the circulation path 72 is the flow path length Lc of a portion overlapping the partition portion 69 of the flow path forming portion 30 in the circulation path 72. Longer than (La> Lc).

Also in the second embodiment, the same effect as that of the first embodiment is realized. In the second embodiment, the second section n2 of each nozzle N and the circulation path 72 are continuous with each other. Therefore, as compared with the configuration of the first embodiment in which the circulation path 72 and the nozzle N are separated from each other, the effect that ink in the vicinity of the nozzle N can be efficiently circulated in the circulating liquid chamber 65 is outstanding. It is remarkable.

Third Embodiment
FIG. 9 is an enlarged plan view and a sectional view of a portion in the vicinity of the circulating liquid chamber 65 in the liquid jet head 26 in the third embodiment. As illustrated in FIG. 9, in the surface Fb of the first flow path substrate 32 in the third embodiment, in addition to the circulating fluid chamber 65 similar to the first embodiment described above, the first portion P1 and the second portion P2 A circulating fluid chamber 67 corresponding to each is formed. The circulating fluid chamber 67 is an elongated bottomed hole (groove) formed on the opposite side of the communicating passage 63 and the nozzle N to the circulating fluid chamber 65 and extending in the Y direction. The openings of the circulating fluid chamber 65 and the circulating fluid chamber 67 are closed by the nozzle plate 52 joined to the surface Fb of the first flow path substrate 32.

The circulation path 72 of the third embodiment is a groove extending in the X direction so as to extend between the circulating fluid chamber 65 and the circulating fluid chamber 67 in each of the first portion P1 and the second portion P2. Specifically, the end of the circulation path 72 on the side of the center plane O (on the side of the circulation fluid chamber 65) overlaps the circulation fluid chamber 65 in plan view, and the side opposite to the center plane O of the circulation pathway 72 (circulation fluid The end of the chamber 67 side overlaps the circulating fluid chamber 67 in plan view. Further, the circulation passage 72 overlaps the communication passage 63 in plan view. That is, each communication passage 63 communicates with both the circulating fluid chamber 65 and the circulating fluid chamber 67 via the circulation passage 72.

A nozzle N (first section n1) is formed at the bottom of the circulation passage 72. Specifically, a first section n1 of the nozzle N is formed on the bottom surface of a portion of the circulation path 72 overlapping the communication path 63 in a plan view. As in the second embodiment, it is also possible to express that the circulation path 72 and the nozzle N (second section n2) are continuous with each other in the third embodiment. As understood from the above description, in the first and second embodiments, the communication passage 63 and the nozzle N are located at the end of the circulation passage 72, whereas in the third embodiment, the communication passage 63 and the nozzle N extend in the X direction. The communication passage 63 and the nozzle N are located in the middle of the circulation passage 72.

As understood from the above description, in the third embodiment, when the pressure in the pressure chamber C fluctuates, part of the ink flowing in the communication passage 63 is ejected from the nozzle N to the outside, and the remaining part is discharged. The fluid is supplied from the communication passage 63 to both the circulating fluid chamber 65 and the circulating fluid chamber 67 via the circulation passage 72. The ink in the circulating fluid chamber 67 is sucked by the circulating mechanism 75 together with the ink in the circulating fluid chamber 65, and bubbles and foreign substances are removed by the circulating mechanism 75 and thickening is reduced before being supplied to the liquid storage chamber R. Ru.

Also in the third embodiment, the same effect as that of the first embodiment is realized. Further, in the third embodiment, since the circulating fluid chamber 67 is formed in addition to the circulating fluid chamber 65, there is an advantage that the circulating amount can be sufficiently secured as compared with the first embodiment. Although FIG. 9 illustrates the configuration in which the circulation passage 72 and the nozzle N are continuous as in the second embodiment, the circulation passage 72 and the nozzle N are similar to the first embodiment in the third embodiment. Can also be spaced apart from one another.

<Modification>
Each form illustrated above can be variously deformed. The aspect of the specific deformation | transformation which may be applied to each above-mentioned form is illustrated below. Two or more aspects arbitrarily selected from the following exemplifications may be combined appropriately as long as they do not contradict each other.

(1) In each of the above-described embodiments, the configuration in which the depths of the circulation passage 72 and the second section n2 of the nozzle N are equal is exemplified, but the relationship between the depth of the circulation path 72 and the depth of the second section n2 is It is not limited to the above examples. For example, a configuration in which the circulation path 72 deeper than the second section n2 is formed as illustrated in FIG. 10 or a configuration in which a circulation path 72 shallower than the second section n2 is formed as illustrated in FIG. According to the configuration of FIG. 10, since the flow path resistance of the circulation path 72 is smaller than that of the configuration of FIG. 11, it is possible to increase the amount of circulation compared to the configuration of FIG. On the other hand, according to the configuration of FIG. 11, since the flow path resistance of the circulation path 72 is large compared to the configuration of FIG. 10, it is possible to increase the injection amount compared to the configuration of FIG.

(2) In each of the above-described embodiments, the configuration in which the depth Da of the circulation passage 72 is constant is illustrated, but it is also possible to change the depth of the circulation passage 72 according to the position in the X direction. For example, as illustrated in FIG. 12, the middle part of the circulation path 72 (for example, the part overlapping the partition 69 in plan view) is the part on the circulating fluid chamber 65 side and the part on the nozzle N side A deeper configuration is assumed. According to the configuration of FIG. 12, the flow path resistance of the circulation path 72 is smaller as compared with the configuration in which the depth Da of the circulation path 72 is constant over the entire length. Therefore, there is an advantage that securing of circulation amount is easy.

(3) In each of the above-described embodiments, the flow path width Wa of the circulation path 72 is exemplified to be equal to the maximum diameter of the nozzle N (inner diameter d2 of the second section n2). It is not limited to. For example, a configuration in which the flow passage width Wa of the circulation passage 72 is smaller than the maximum diameter of the nozzle N (for example, the inner diameter d2 of the second section n2) may be employed. According to the above configuration, the flow path resistance of the circulation path 72 is large as compared with the structure in which the circulation path 72 is larger than the maximum diameter of the nozzle N. Therefore, it is possible to increase the injection amount. Also, a configuration in which the flow passage width Wa of the circulation passage 72 is larger than the inner diameter d1 of the first section n1 may be employed. According to the above configuration, it is possible to achieve both the securing of the circulation amount and the securing of the injection amount.

(4) In the above-described embodiments, the flow passage width Wa of the circulation passage 72 is constant, but it is also possible to change the flow passage width of the circulation passage 72 according to the position in the X direction. For example, as illustrated in FIG. 13, a configuration may be employed in which the channel width of the portion on the circulating fluid chamber 65 side of the circulation channel 72 is wider than the channel width on the nozzle N side. Specifically, the circulation passage 72 is formed so that the flow passage width of the circulation passage 72 has a planar shape that monotonously increases from the end on the nozzle side to the end on the circulating fluid chamber 65 side. According to the configuration of FIG. 13, the ink easily flows in the circulation passage 72 from the communication passage 63 toward the circulating liquid chamber 65. Therefore, there is an advantage that securing of circulation amount is easy.

Further, as illustrated in FIG. 14, the flow passage width of the middle portion (for example, the portion overlapping the partition portion 69 in plan view) of the circulation passage 72 is the flow passage width of the portion on the circulating liquid chamber 65 side as viewed from the middle portion. A configuration narrower than the channel width of the portion on the side of the nozzle N and the nozzle N may also be employed. That is, the flow passage width monotonously decreases from both ends of the circulation passage 72 to the middle portion so that the flow passage width becomes minimum at a part in the middle of the circulation passage 72 (for example, a part overlapping the partition 69 in plan view). . According to the configuration of FIG. 14, the flow path resistance of the circulation path 72 is large as compared with the configuration in which the flow path width of the circulation path 72 is constant. Therefore, it is possible to increase the injection amount.

As illustrated in FIG. 15, the flow passage width of the middle portion (for example, the portion overlapping the partition portion 69 in plan view) of the circulation path 72 is the flow passage width of the portion on the circulation liquid chamber 65 side and the nozzle A configuration wider than the channel width of the N-side portion may also be employed. That is, the flow passage width monotonously increases from both ends of the circulation passage 72 to the middle portion so that the flow passage width becomes maximum at a middle portion of the circulation passage 72 (for example, a portion overlapping the partition 69 in plan view). . According to the configuration of FIG. 15, the flow path resistance of the circulation path 72 is smaller as compared with the configuration in which the flow path width of the circulation path 72 is constant. Therefore, it is possible to increase the amount of circulation.

In order to secure mechanical strength of the partition portion 69 of the first flow path substrate 32, the partition portion 69 needs to be formed thick. However, the flow path resistance of the circulation path 72 increases as the partition portion 69 is thicker (the flow path length Lc is larger). According to the configuration of FIG. 15, even when the thickness of the partition portion 69 is secured to a degree that a sufficient strength is realized, the flow path resistance of the circulation path 72 can be reduced by widening the middle portion of the circulation path 72. It has the advantage of That is, it is possible to achieve both the securing of the strength of the partition portion 69 and the reduction of the flow path resistance of the circulation path 72.

(5) In each embodiment described above, the central axis Qa of the nozzle N is located on the opposite side of the circulating fluid chamber 65 when viewed from the central axis Qb of the communication passage 63. The relationship between the passage 63 and the central axis Qb is not limited to the above example. For example, as illustrated in FIG. 16, the central axis Qa of the nozzle N and the central axis Qb of the communication passage 63 may be at the same position. According to the configuration of FIG. 16, there is an advantage that it is easy to achieve both securing of the injection amount and securing of the circulating amount, as compared with the configuration in which the central axis Qa and the central axis Qb are at different positions.

Further, as exemplified in FIG. 17, a configuration in which the central axis Qa of the nozzle N is located on the circulating fluid chamber 65 side (central plane O side) with respect to the central axis Qb of the communication passage 63 may be employed. According to the configuration of FIG. 17, compared to the configuration (for example, the first embodiment) in which the central axis Qa of the nozzle N is located on the opposite side to the circulating fluid chamber 65 when viewed from the central axis Qb of the communication passage 63 It is possible to reduce the injection amount while increasing the On the other hand, according to the configuration in which the central axis Qa of the nozzle N is located on the opposite side of the circulating fluid chamber 65 when viewed from the central axis Qb of the communication passage 63 as in each of the embodiments described above, compared with the configuration of FIG. It is possible to reduce the amount of circulation and to increase the amount of injection.

(6) In each of the above-described embodiments, the circulating fluid chamber 65 having a shape defined by the side surface parallel to the YZ plane and the upper surface (ceiling surface) parallel to the XY plane has been illustrated. The shape of is not limited to the above examples. For example, as illustrated in FIG. 18, it is also possible to form in the first flow path substrate 32 a circulating fluid chamber 65 whose side surface is inclined with respect to the upper surface parallel to the XY plane. Specifically, the side surface of the circulating fluid chamber 65 is inclined with respect to the upper surface such that the channel width (dimension in the X direction) of the circulating fluid chamber 65 increases as the position on the positive side in the Z direction.

According to the configuration of FIG. 18, the partition 69 is formed thicker than in the above-described configurations in which the side surface of the circulating fluid chamber 65 is parallel to the YZ plane. There is an advantage that sufficient strength can be secured. The configuration of FIG. 18 which can ensure the mechanical strength of the partition portion 69 is the same as that of the first flow path substrate 32, considering that the first flow path substrate 32 is pressed in the Z direction when the wiring substrate 28 is mounted. It is effective from the viewpoint of preventing damage and the like. Further, according to the configuration in which the side surface of the circulating fluid chamber 65 is inclined as illustrated in FIG. 18, there is also an advantage that the ink can easily flow in the circulating fluid chamber 65. In the above description, attention was paid to the circulating fluid chamber 65, but similarly for the circulating fluid chamber 67 exemplified in the third embodiment, a shape in which the side surface is inclined with respect to the upper surface parallel to the XY plane is adopted. It is possible. In FIG. 18, the flow path length Lc of the portion of the circulation path 72 overlapping the partition portion 69 of the flow path forming portion 30 is the length of the portion of the circulation path 72 overlapping the surface Fb of the partition portion 69.

(7) As illustrated in FIG. 19, an end face of the pressure chamber C on the communication passage 63 side (central plane O side) is inclined with respect to the upper surface of the pressure chamber C (lower surface of the vibrating portion 42). The configuration is also suitable. As understood from FIG. 19, the area (area not covered by the inclined surface 342) 344 of the vibrating portion 42 exposed from the second flow path substrate 34 does not overlap with the circulation path 72 in a plan view. A region 344 in FIG. 19 constitutes the upper surface (ceiling surface) of the pressure chamber C.

(8) As exemplified in FIG. 20, a flow path (hereinafter referred to as “common to be continuous with the circulation path 72 (first circulation path) of the first portion P1 and the circulation path 72 (second circulation path) of the second portion P2. It is also possible to form the circulation path 73) in the nozzle plate 52. The common circulation passage 73 is a recess formed on the surface of the nozzle plate 52 facing the flow passage forming portion 30. The common circulation passage 73 is formed at the same depth as each circulation passage 72. The common circulation path 73 illustrated in FIG. 20 extends in the Y direction so as to overlap the circulating fluid chamber 65 in plan view (specifically, the peripheral edge of the common circulating channel 73 is included in the peripheral edge of the circulating fluid chamber 65) Exist. The width (dimension in the X direction) of the common circulation path 73 is narrower than the width (dimension in the X direction) of the circulating fluid chamber 65.

As illustrated in FIG. 20, the X-direction negative end of each of the plurality of circulation paths 72 of the first portion P1 is continuous with the X-direction positive circumference of the common circulation path 73. Similarly, the end on the positive side in the X direction of each of the plurality of circulation paths 72 of the second portion P2 is continuous with the peripheral edge on the negative side in the X direction of the common circulation path 73. That is, the common circulation passage 73 is formed between the arrangement of the plurality of circulation passages 72 in the first portion P1 and the arrangement of the plurality of circulation passages 72 in the second portion P2. A plurality of circulation paths 72 of the first portion P1 extend from the peripheral edge on the positive side in the X direction in the common circulation path 73 to the positive side in the X direction, and from the peripheral edge on the negative side in the X direction in the common circulation path 73 In other words, the plurality of circulation paths 72 of the two-part P2 extend on the negative side in the X direction.

As exemplified above, according to the configuration of FIG. 20 in which the common circulation passage 73 is formed in the nozzle plate 52, each circulation passage 72 is compared with a configuration in which the common circulation passage 73 is not formed (for example, each form described above). It is possible to increase the flow area of the ink supplied to the circulating liquid chamber 65 (thereby reducing the flow resistance). The configuration in which the common circulation path 73 is formed in the nozzle plate 52 is similarly applied to any of the above-described embodiments (the first to third embodiments and each modification).

(9) In each of the above-described embodiments, the elements related to the first row L1 and the elements related to the second row L2 are arranged symmetrically with respect to the center plane O. Is not required. For example, a configuration in which elements corresponding to only the first row L1 are arranged in the same manner as in the above-described embodiments may be employed. Further, although the configuration in which the circulation path 72 is formed in the nozzle plate 52 is illustrated in the above-described embodiments, the flow path forming portion 30 (for example, the first flow path substrate) It is also possible to form on the 32 surfaces Fb).

(10) The element (pressure generating unit) for applying pressure to the inside of the pressure chamber C is not limited to the piezoelectric element 44 exemplified in the above-described embodiments. For example, it is also possible to use a heating element that generates air bubbles inside the pressure chamber C by heating to change the pressure as a pressure generation unit. The heat generating element is a portion where the heat generating element generates heat by the supply of the drive signal (specifically, a region where air bubbles are generated in the pressure chamber C). As understood from the above examples, the pressure generating portion is comprehensively expressed as an element which causes the liquid in the pressure chamber C to be jetted from the nozzle N (typically, an element which applies a pressure to the inside of the pressure chamber C). The operation method (piezoelectric method / thermal method) and the specific configuration are irrelevant.

(11) In each of the above-described embodiments, the serial type liquid ejecting apparatus 100 for reciprocating the transport body 242 having the liquid ejecting head 26 mounted is illustrated, but a line type liquid in which a plurality of nozzles N are distributed over the entire width of the medium 12 It is possible to apply the present invention to an injector.

(12) The liquid ejecting apparatus 100 exemplified in each of the above-described embodiments may be adopted to various apparatuses such as a facsimile machine and a copier other than the apparatus dedicated to printing. However, the application of the liquid ejecting apparatus of the present invention is not limited to printing. For example, a liquid ejecting apparatus that ejects a color material solution is used as a manufacturing apparatus that forms a color filter of a liquid crystal display device. In addition, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus that forms wiring and electrodes of a wiring board.

DESCRIPTION OF SYMBOLS 100 ... Liquid ejection apparatus, 12 ... Medium, 14 ... Liquid container, 20 ... Control unit, 22 ... Transport mechanism, 24 ... Movement mechanism, 242 ... Transport body, 244 ... Transport belt, 26 ... Liquid ejection head, 28 ... Wiring board , 30: flow passage forming portion, 32: first flow passage substrate, 34: second flow passage substrate, 42: vibration portion, 44: piezoelectric element, 46: protection member, 48: housing portion, 482: introduction port, 52: nozzle plate, 54: vibration absorber, 61: supply passage, 63: communication passage, 65, 67: circulating fluid chamber, 67: circulating fluid chamber, 69: partition wall, n1: first section, n2: second section , 72 ... circulation path, 75 ... circulation mechanism.

Claims

A nozzle plate provided with a first nozzle and a second nozzle;
The first pressure chamber and the second pressure chamber to which the liquid is supplied, the first communication passage connecting the first nozzle and the first pressure chamber, the second nozzle and the second pressure chamber are communicated. A flow passage forming portion provided with a second communication passage, and a circulating fluid chamber positioned between the first communication passage and the second communication passage;
A pressure generating unit for generating a pressure change in each of the first pressure chamber and the second pressure chamber;
The nozzle plate is provided with a first circulation passage connecting the first communication passage and the circulating fluid chamber, and a second circulation passage connecting the second communication passage and the circulating fluid chamber. head.
2. The liquid jet head according to claim 1, wherein the first nozzle includes a first section, and a second section which is larger in diameter than the first section and located on the flow path forming portion side with respect to the first section.
The liquid jet head according to claim 2, wherein the first circulation path has the same depth as the second section.
The liquid jet head according to claim 2, wherein the first circulation path is deeper than the second section.
The liquid jet head according to claim 2, wherein the first circulation path is shallower than the second section.
The liquid jet head according to any one of claims 2 to 5, wherein the second section is continuous with the first circulation path.
The liquid jet head according to any one of claims 1 to 5, wherein the first nozzle and the first circulation path are separated from each other in a plane of the nozzle plate.
A flow path length La of a portion overlapping the circulating fluid chamber in the first circulation path and a flow path length Lb of a portion overlapping the first communication path in the first circulation path satisfy La> Lb. 8. A liquid jet head according to item 7.
A flow path length Lc of a portion of the first circulation path that overlaps the partition wall portion between the first communication path and the circulating fluid chamber in the flow path formation portion satisfies La>Lb> Lc. Liquid jet head.
A flow path length La of a portion of the first circulation path overlapping the circulation liquid chamber, and a partition between the first communication path and the circulation liquid chamber in the flow path formation portion of the first circulation path The liquid jet head according to claim 6, wherein a flow path length Lc of a portion overlapping the portion satisfies La> Lc.
The liquid jet head according to any one of claims 1 to 10, wherein a flow passage width of the first circulation passage is smaller than a maximum diameter of the first nozzle.
The liquid jet head according to any one of claims 1 to 11, wherein a flow passage width of the first circulation passage is smaller than a flow passage width of the first pressure chamber.
The liquid jet head according to any one of claims 1 to 12, wherein a flow passage width of a portion on the circulation liquid chamber side of the first circulation passage is wider than a flow passage width of a portion on the first nozzle side.
The flow passage width of the middle portion of the first circulation passage is narrower than the flow passage width of the portion on the circulating fluid chamber side and the flow passage width of the portion on the first nozzle side as viewed from the middle portion. The liquid jet head according to claim 12.
The flow passage width of the middle portion of the first circulation passage is wider than the flow passage width of the portion on the circulating fluid chamber side and the flow passage width of the portion on the first nozzle side as viewed from the middle portion. The liquid jet head according to claim 12.
The liquid jet head according to any one of claims 1 to 15, wherein a central axis of the first nozzle is located on the opposite side of the circulating liquid chamber when viewed from a central axis of the first communication passage.
The liquid jet head according to any one of claims 1 to 15, wherein a central axis of the first nozzle is at the same position as a central axis of the first communication passage.
The liquid jet head according to any one of claims 1 to 15, wherein a central axis of the first nozzle is located on the circulating liquid chamber side with respect to a central axis of the first communication passage.
The liquid jet head according to any one of claims 1 to 18, wherein an intermediate portion of the first circulation path is deeper than a portion on the circulating fluid chamber side and a portion on the first nozzle side as viewed from the intermediate portion.
When a pressure change occurs in the first pressure chamber, the amount of liquid supplied to the circulating fluid chamber through the first circulation path is larger than the amount of liquid injected from the first nozzle. 20. A liquid jet head according to any one of claims 1 to 19.
The first circulation path and the circulating fluid chamber overlap each other,
The first circulation passage and the first pressure chamber overlap each other,
The liquid jet head according to any one of claims 1 to 20, wherein the circulating fluid chamber and the first pressure chamber do not overlap with each other.
The first circulation path and the circulating fluid chamber overlap each other,
The first circulation passage and the pressure generating portion overlap each other,
The liquid jet head according to any one of claims 1 to 20, wherein the circulating fluid chamber and the pressure generator do not overlap with each other.
The end face of the first pressure chamber on the side of the first communication passage is an inclined surface inclined with respect to the upper surface of the first pressure chamber,
The liquid jet head according to any one of claims 1 to 20, wherein the first circulation path and the upper surface of the first pressure chamber do not overlap with each other.
The liquid jet head according to any one of claims 1 to 23, wherein the first pressure chamber and the circulating fluid chamber communicate with each other through the first communication passage and the first circulation passage.
The liquid jet head according to any one of claims 1 to 24, wherein each of the nozzle plate and the flow path forming portion includes a substrate formed of silicon.
The liquid jet head according to any one of claims 1 to 25, wherein the nozzle plate is provided with a common circulation passage which is continuous with the first circulation passage and the second circulation passage.
A liquid ejecting apparatus comprising the liquid ejecting head according to any one of claims 1 to 26.