JP7367522B2 - Liquid ejection head, head module, head unit, liquid ejection unit, device that ejects liquid - Google Patents

Description

The present invention relates to a liquid ejection head, a head module, a head unit, a liquid ejection unit, and an apparatus for ejecting liquid.

In a liquid ejection head that ejects liquid, it is necessary to suppress crosstalk in which pressure fluctuations associated with liquid ejection affect the ejection characteristics of other pressure chambers (individual liquid chambers) via a common flow path.

BACKGROUND ART Conventionally, there has been known a pressure chamber circulation type head having a common flow path main stream and a common flow path tributary, which includes a damper forming a part of the wall surface of the common flow path tributary (Patent Document 1).

JP 2019-155683 Publication

By the way, although crosstalk can be suppressed in the configuration disclosed in Patent Document 1, further improvement is required in suppressing pressure fluctuations in the common flow path within the head.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress pressure fluctuations in a common flow path.

In order to solve the above problems, a liquid ejection head according to the present invention includes:
a plurality of pressure chambers each communicating with a plurality of nozzles that discharge liquid;
a plurality of individual flow paths each communicating with the plurality of pressure chambers;
a plurality of common flow channel tributaries each communicating with the two or more individual flow channels;
a common flow channel main stream communicating with the plurality of common flow channel tributaries;
a damper member forming a displaceable wall surface of each of the plurality of common flow channel tributaries,
A partition portion is provided on the opposite side of the partition wall portion between the common flow path tributaries of the damper member,
A concave portion is provided on a joint surface of the partition portion with the damper member.

According to the present invention, pressure fluctuations in the common flow path can be suppressed.

FIG. 1 is an exploded perspective explanatory view of a liquid ejection head according to a first embodiment of the present invention. It is an exploded perspective explanatory view similarly excluding a frame member. FIG. 4 is a cross-sectional perspective view of the flow path portion. Similarly, it is a plan explanatory view of a flow path portion. 5 is a cross-sectional explanatory diagram corresponding to the line AA in FIG. 4. FIG. FIG. 6 is a cross-sectional explanatory view similar to FIG. 5 of a liquid ejection head according to a second embodiment of the present invention. FIG. 1 is an exploded perspective view of an example of a head module according to the present invention. It is an exploded perspective explanatory view of the same head module seen from the nozzle surface side. FIG. 1 is a schematic explanatory diagram of an example of a device for discharging liquid according to the present invention. FIG. 2 is an explanatory plan view of an example of a head unit of the apparatus.

Embodiments of the present invention will be described below with reference to the accompanying drawings. A first embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is an exploded perspective view of a liquid ejection head according to the same embodiment, FIG. 2 is an exploded perspective view of the liquid ejection head excluding a frame member, and FIG. 3 is a cross-sectional perspective view of a flow path portion. 4 is an explanatory plan view of the flow path portion, and FIG. 5 is an explanatory cross-sectional view corresponding to the line AA in FIG. 4.

The liquid ejection head 1 includes a nozzle plate 10, a channel plate (individual channel member) 20, a diaphragm member 30, a common channel member 50, a damper member 60, a damper frame member 70, and a frame member 80. and a wiring board 45 on which a drive circuit 46 is mounted.

The nozzle plate 10 has a plurality of nozzles 11 that eject liquid. The plurality of nozzles 11 are arranged in a two-dimensional matrix and constitute a nozzle group NG (NG1, NG2: FIG. 1).

The individual channel member 20 forms a plurality of pressure chambers (individual liquid chambers) 21, an individual supply channel 22, and an individual recovery channel 23. The plurality of pressure chambers 21 communicate with the plurality of nozzles 11, respectively. The plurality of individual supply channels 22 communicate with the plurality of pressure chambers 21, respectively. The plurality of individual recovery channels 23 communicate with the plurality of pressure chambers 21, respectively. The individual supply channel 22 and the individual recovery channel 23 are individual channels.

The diaphragm member 30 forms a diaphragm 31 that is a deformable wall surface of the pressure chamber 21 . A piezoelectric element 40 is integrally provided on the diaphragm 31. The diaphragm member 30 is formed with a supply side opening 32 communicating with the individual supply channel 22 and a recovery side opening 33 communicating with the individual recovery channel 23. The piezoelectric element 40 is a pressure generating means that deforms the diaphragm 31 and pressurizes the liquid in the pressure chamber 21.

The common flow path member 50 is formed such that common supply flow path tributaries 52 and common recovery flow path tributaries 53, which are common flow path tributaries, are alternately adjacent to each other. The common supply channel tributary 52 communicates with two or more individual supply channels 22 . The common recovery channel tributary 53 communicates with two or more individual recovery channels 23 . The common supply channel branch 52 and the common recovery channel branch 53, which are the common channel branches, are separated by a partition wall 58.

The common channel member 50 includes a through hole that serves as a supply port 54 that communicates with the supply side opening 32 of the individual supply channel 22 and the common supply channel tributary 52, and a through hole that connects the recovery side opening 33 of the individual recovery channel 23 with the common recovery channel. A through hole is formed to serve as a recovery port 55 through which the tributary stream 53 passes. The supply port 54 is an opening that communicates the common supply channel tributary 52 to the pressure chamber 21 . The recovery port 55 is an opening that communicates the common recovery channel tributary 53 to the pressure chamber 21 .

The common channel member 50 is a member that forms a main stream of the common channel, and communicates with one or more main streams 56 of common supply channels that communicate with the tributaries 52 of the common supply channels, and tributaries 53 of the common recovery channels. One or more common main recovery channels 57 are formed.

The damper member 60 is a member that forms a displaceable wall surface (hereinafter referred to as a "damper") of the common flow path tributaries (the common supply flow path tributary 52 and the common recovery flow path tributary 53). The damper member 60 has a supply side damper 62 that is a wall surface that faces (opposes) the supply port 54 of the common supply channel tributary 52, and a wall surface that faces (opposes) the recovery port 55 of the common recovery channel tributary 53. A recovery side damper 63 is formed.

Here, the common supply flow path tributary 52 and the common recovery flow path tributary 53 connect a plurality of grooves arranged alternately in the common flow path member 50, which is the same member, to the supply side damper 62 or the recovery side damper of the damper member 60. It is configured by sealing with 63. Note that as the damper material (flexible material) of the damper member 60, it is preferable to use a metal thin film or an inorganic thin film that is resistant to organic solvents. The thickness of the supply side damper 62 and recovery side damper 63 portions of the damper member 60 is preferably 10 μm or less.

Portions of the damper member 60 corresponding to the main stream 56 of the common supply channel and the main stream 57 of the common recovery channel are filter portions 66 (FIG. 5) and 67 (FIG. 2).

The damper member 60 is held by a damper frame member 70 that is a support member (holding member). The damper frame member 70 forms a partition portion 78 disposed on the opposite side from the partition wall portion 58 between the common flow channel tributaries of the damper member 60 .

The partition portion 78 is provided at a position facing the partition wall portion 58 between the common supply channel branch 52 and the common recovery channel branch 53 with the damper member 60 interposed therebetween. A joint surface 78a of the partition portion 78 is joined to the damper member 60 with an adhesive 77.

A recessed portion 79 is provided on the joint surface 78a of the partition portion 78 with the damper member 60. A space is formed between the partition portion 78 and the damper member 60 by providing the recessed portion 79 . Further, since the partition portion 78 is provided with the recessed portion 79, the thickness h of the recessed portion 79 is smaller than that of the other portion (the portion joined to the damper member 60).

Here, a damper serving as a displaceable wall surface is formed with the common flow path member 50 forming the common supply flow path tributary 52 and the common recovery flow path tributary 53 and the damper frame member 70 forming the partition portion 78. The coefficient of linear expansion is different from that of the damper member 60.

The partition portion 78 of the damper frame member 70, the damper member 60, and the partition wall portion 58 of the common flow path member 50 are bonded by applying an adhesive 77 to the joint surfaces and heating under pressure. 77 is cured and joined.

At this time, a gap (space) is created between the partition part 78 of the damper frame member 70 and the damper member 60 due to the recessed part 79. Therefore, even if the partition portion 78 and the partition wall portion 58 are pressurized via the damper member 60, the damper member 60 is not pressurized at the recessed portion 79 of the partition portion 78.

Therefore, when the adhesive 77 is heated and cured, the supply side damper 62 and the recovery side damper 63 of the damper member 60 are bent due to the difference in linear expansion coefficient between the common flow path member 50 and the damper member 60. It is joined to the partition wall part 58 and the partition part 78.

In this way, the supply-side damper 62 and the recovery-side damper 63 are in a deflected state, so that the compliance of the common supply flow path tributary 52 and the common recovery flow path tributary 53 increases, resulting in a vibration damping or vibration suppression effect. (damper effect) is increased, and pressure fluctuations can be further suppressed. By being able to suppress pressure fluctuations in the common supply channel tributary 52 and the common recovery channel tributary 53, stable liquid supply can be performed.

Note that it is preferable that the bent supply side damper 62 and recovery side damper 63 do not contact the bottom surface of the recessed part 79 of the partition part 78 of the damper frame member 70 so as not to reduce the damper effect.

In addition, a member forming a common flow path tributary (common flow path member 50), a member forming a partition portion 78 (damper frame member 70), and a member forming a damper serving as a displaceable wall surface (damper member 60) has a different coefficient of linear expansion.

This allows the supply side damper 62 and the recovery side damper 63 to be deflected, and also prevents displacement of the bonding position.

In the liquid ejection head 1 described above, the liquid supplied from the external liquid circulation path to the supply port 81 is supplied to the common supply channel main stream 56, the common supply channel tributary 52, the supply port 54, the supply side opening 32, the individual supply It is supplied to the pressure chamber 21 via the flow path 22.

The liquid other than the liquid discharged from the nozzle 11 by driving the piezoelectric element 40 is transferred from the pressure chamber 21 to the individual recovery channel 23, the recovery side opening 33, the recovery port 55, the common recovery channel tributary 53, and the common recovery channel 53. The liquid is returned to the external liquid circulation path via the main recovery channel 57 and the recovery port 82 .

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional explanatory view similar to FIG. 5 of the liquid ejection head according to the same embodiment.

In this embodiment, the recessed portion 79 of the partition portion 78 is locally provided in a portion corresponding to the supply port 54 which is the opening of the common supply channel tributary 52 and the recovery port 55 which is the opening of the common recovery channel tributary 53. ing.

As a result, the portion of the supply side damper 62 facing the supply port 54, which is the outlet of the pressure wave from the pressure chamber 21, can be deflected, and the compliance can be effectively increased. In addition, the joining area between the partition portion 78 and the damper member 60 can be made wider than in the first embodiment, and joint defects can be reduced.

Next, an example of the head module according to the present invention will be described with reference to FIGS. 7 and 8. FIG. 7 is an exploded perspective view of the head module, and FIG. 8 is an exploded perspective view of the head module viewed from the nozzle surface side.

The head module 100 includes a plurality of heads 1 that are liquid ejection heads that eject liquid, a base member 103 that holds the plurality of heads 1, and a cover member 113 that serves as a nozzle cover for the plurality of heads 1.

The head module 100 also includes a heat dissipation member 104, a manifold 105 forming a flow path for supplying liquid to a plurality of heads, a printed circuit board (PCB) 106 connected to the flexible wiring member 101, and a module case. 107.

Next, an example of a device for discharging liquid according to the present invention will be described with reference to FIGS. 9 and 10. FIG. 9 is a schematic explanatory diagram of the same device, and FIG. 10 is a plan explanatory diagram of an example of a head unit of the same device.

The printing device 500 is a device that discharges liquid. The printing device 500 includes a carrying-in means 501, a guiding conveying means 503, a printing means 505, a drying means 507, an unloading means 509, and the like. The carrying means 501 carries in a web-like sheet material P. The guide conveyance means 503 guides and conveys the sheet material P carried in from the carry-in means 501 to the printing means 505. The printing unit 505 performs printing to form an image by discharging liquid onto the sheet material P. The drying means 507 dries the sheet material P. The carrying-out means 509 carries out the sheet material P.

The sheet material P is sent out from the original winding roller 511 of the carry-in means 501, guided and conveyed by each roller of the carry-in means 501, the guide conveyance means 503, the drying means 507, and the carry-out means 509, and then taken up by the winding roller 591 of the carry-out means 509. It is wound up.

In the printing means 505, this sheet material P is conveyed on a conveyance guide member 559 facing the head unit 550, and an image is printed by liquid discharged from the head unit 550.

Here, the head unit 550 includes two head modules 100A and 100B according to the present invention on a common base member 552.

When the direction in which the heads 1 are lined up in the direction perpendicular to the transport direction of the head module 100 is defined as the head arrangement direction, the head rows 1A1 and 1A2 of the head module 100A eject liquid of the same color. Similarly, the head rows 1B1 and 1B2 of the head module 100A are set as a set, the head rows 1C1 and 1C2 of the head module 100B are set as a set, and the head rows 1D1 and 1D2 are set as a set, and liquid of a desired color is ejected, respectively.

In the present application, the liquid to be ejected may have a viscosity and surface tension that can be ejected from the head, and is not particularly limited, but the viscosity becomes 30 mPa・s or less at room temperature and normal pressure, or by heating or cooling. Preferably. More specifically, solvents such as water and organic solvents, coloring agents such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , edible materials such as natural pigments, etc., and these include, for example, inkjet inks, surface treatment liquids, constituent elements of electronic devices and light emitting devices, and formation of electronic circuit resist patterns. It can be used for purposes such as a liquid for use in liquids, a material liquid for three-dimensional modeling, and the like.

Piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators using electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a diaphragm and opposing electrodes are used as energy sources for discharging liquid. Includes things that do.

A "liquid ejection unit" is a liquid ejection head with functional parts and mechanisms integrated, and includes an assembly of parts related to liquid ejection. For example, the "liquid ejection unit" includes a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, a liquid circulation device, and a combination of at least one of the following components with a liquid ejection head.

Here, integration refers to, for example, a liquid ejection head, a functional component, or a mechanism fixed to each other by fastening, adhesion, engagement, etc., or one in which one is held movably relative to the other. include. Further, the liquid ejection head, the functional parts, and the mechanism may be configured to be detachable from each other.

For example, some liquid ejection units have a liquid ejection head and a head tank integrated. In addition, there are devices in which a liquid ejection head and a head tank are integrated by being connected to each other with a tube or the like. Here, a unit including a filter may be added between the head tank and the liquid ejection head of these liquid ejection units.

Further, some liquid ejection units have a liquid ejection head and a carriage integrated.

Further, some liquid ejection units have the liquid ejection head movably held by a guide member that constitutes a part of the scanning movement mechanism, so that the liquid ejection head and the scanning movement mechanism are integrated. Further, there are some in which the liquid ejection head, the carriage, and the main scanning movement mechanism are integrated.

Furthermore, some liquid ejection units have a cap member, which is part of the maintenance recovery mechanism, fixed to the carriage to which the liquid ejection head is attached, so that the liquid ejection head, the carriage, and the maintenance recovery mechanism are integrated. .

Further, some liquid ejection units have a tube connected to a liquid ejection head to which a head tank or a flow path component is attached, so that the liquid ejection head and a supply mechanism are integrated. The liquid from the liquid storage source is supplied to the liquid ejection head through this tube.

The main scanning movement mechanism also includes a single guide member. Further, the supply mechanism includes a single tube and a single loading section.

Note that although the "liquid ejection unit" is explained here in combination with a liquid ejection head, the "liquid ejection unit" includes a head module including the liquid ejection head described above, a head unit, and the functions described above. It also includes parts and mechanisms that are integrated.

The "device for ejecting liquid" includes a device that includes a liquid ejection head, a liquid ejection unit, a head module, a head unit, etc., and drives the liquid ejection head to eject liquid. Devices that eject liquid include not only devices that can eject liquid onto objects to which liquid can adhere, but also devices that eject liquid into the air or into liquid.

The "device for discharging liquid" may include means for feeding, transporting, and discharging objects to which liquid can adhere, as well as pre-processing devices, post-processing devices, and the like.

For example, an image forming device is a device that ejects ink to form an image on paper as a “device that ejects liquid,” and an image forming device that forms layers of powder to form three-dimensional objects (three-dimensional objects). There is a three-dimensional modeling device (three-dimensional modeling device) that discharges a modeling liquid onto a powder layer.

Further, the "device for ejecting liquid" is not limited to a device that can visualize significant images such as characters and figures using ejected liquid. For example, it includes those that form patterns that have no meaning in themselves, and those that form three-dimensional images.

The above-mentioned "something to which a liquid can adhere" refers to something to which a liquid can adhere at least temporarily, such as something that adheres and sticks, something that adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic components such as electronic boards, piezoelectric elements, powder layers, organ models, and test cells. Unless otherwise specified, it includes everything to which liquid adheres.

The material for the above-mentioned "material to which liquid can adhere" may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc., as long as liquid can adhere thereto, even temporarily.

Further, the "device for discharging liquid" includes a device in which a liquid discharging head and an object to which liquid can be attached move relative to each other, but the present invention is not limited to this. Specific examples include a serial type device that moves a liquid ejection head, a line type device that does not move a liquid ejection head, and the like.

In addition, the "device for discharging a liquid" includes a processing liquid coating device that discharges a processing liquid onto paper in order to apply the processing liquid to the surface of the paper for the purpose of modifying the surface of the paper, etc. There is an injection granulation device that granulates fine particles of the raw material by spraying a composition liquid in which the raw material is dispersed in a solution through a nozzle.

In addition, in the terms of this application, image formation, recording, printing, imprinting, printing, modeling, etc. are all synonymous.

1 Liquid discharge head 10 Nozzle plate 11 Nozzle 20 Individual channel member 21 Pressure chamber 22 Individual supply channel 23 Individual recovery channel 30 Vibration plate member 40 Piezoelectric element 50 Common channel member 52 Common supply channel tributary 53 Common recovery channel Tributary stream 54 Supply port 55 Recovery port 56 Common supply channel main stream 57 Common recovery channel main stream 58 Partition wall section 60 Damper member 62 Supply side damper 63 Supply side damper 70 Damper frame member 78 Partition section 79 Recess section 100 Head module 403 Carriage 440 Liquid Discharge unit 500 Printing device (device that discharges liquid)
550 head unit

Claims (9)

a plurality of pressure chambers each communicating with a plurality of nozzles that discharge liquid;
a plurality of individual flow paths each communicating with the plurality of pressure chambers;
a plurality of common flow channel tributaries each communicating with the two or more individual flow channels;
a common flow channel main stream communicating with the plurality of common flow channel tributaries;
a damper member forming a displaceable wall surface of each of the plurality of common flow channel tributaries,
A partition portion is provided on the opposite side of the partition wall portion between the common flow path tributaries of the damper member,
A liquid ejection head characterized in that a recessed portion is provided on a joint surface of the partition portion with the damper member. The two or more individual channels are an individual supply channel and an individual recovery channel,
The common flow path tributary is a common supply flow path tributary that communicates with the individual supply flow path and a common recovery flow path tributary that communicates with the individual recovery flow path,
2. The liquid ejection head according to claim 1, wherein the partition between the common flow path tributaries is a partition between the common supply flow path tributary and the common recovery flow path tributary. 3. The liquid ejection head according to claim 1, wherein the recessed portion of the partition portion is provided in a portion corresponding to an opening of the common flow path tributary that communicates with the pressure chamber. Liquid discharge according to any one of claims 1 to 3, wherein the member forming the common flow channel tributary, the member forming the partition portion, and the damper member have different linear expansion coefficients. head. 5. The liquid ejection head according to claim 1, wherein the displaceable wall surface formed by the damper member has flexure. A head module comprising a plurality of liquid ejection heads according to claim 1 arranged. A head unit comprising the head modules according to claim 6 arranged side by side. A liquid ejection unit comprising the liquid ejection head according to any one of claims 1 to 5, the head module according to claim 6, or the head unit according to claim 7. Comprising at least one of the liquid ejection head according to any one of claims 1 to 5, the head module according to claim 6, the head unit according to claim 7, and the liquid ejection unit according to claim 8. A device for discharging liquid characterized by:

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