JP2019162770A - Liquid discharge head, liquid discharge unit, and liquid discharge device - Google Patents

Abstract

To provide a liquid discharge head reduced in variation of discharge characteristics of droplets discharged from a nozzle regardless of a dimensional variation of components forming a flow passage.SOLUTION: A liquid discharge head includes: a nozzle plate 3 in which a plurality of nozzles 3a for discharging droplets are formed; a flow passage plate 2 in which a bulkhead 2d for sectioning a plurality of pressure chambers 2a communicated with at least the plurality of nozzles 3a is formed; a diaphragm 6 which covers a surface opposed to a surface covered with the nozzle plate 3 of the flow passage plate 2 so that the pressure chambers 2a are partitioned; and driving means 5 which vibrates the diaphragm 6 so as to generate pressure for pressurizing liquid in the pressure chamber. The bulkhead 2d for sectioning the pressure chambers 2a has bulging-out of an adhesive 9 used for joining at peripheral edges of a joined section to the nozzle plate 3 and a joined section to the diaphragm 6. Application quantity of the adhesive 9 used for joining the bulkhead 2d, the nozzle plate 3, and the diaphragm 6 is different according to the width of the bulkhead 2d.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a liquid discharge head, a liquid discharge unit, and an apparatus for discharging liquid.

  As an image forming apparatus such as a printer, a facsimile, a copying machine, a plotter, or a complex machine of these, for example, a liquid discharge recording type image forming using a recording head composed of a liquid discharge head (droplet discharge head) that discharges ink droplets. An apparatus (for example, an ink jet recording apparatus) is known.

  In a liquid discharge head (droplet discharge head) that discharges a liquid, a fluid is introduced from a common liquid chamber or a liquid introducing portion that communicates with the common liquid chamber for the purpose of increasing the efficiency of pressurizing the liquid in the pressure chamber (individual liquid chamber). A configuration is known in which a liquid is supplied to a pressure chamber via a resistance portion, such as a narrow fluid resistance portion, a pressure chamber on the downstream side of the fluid resistance portion, and a common liquid chamber or a liquid introduction portion on the upstream side. A flow path plate (flow path member) that forms a flow path is used.

  When the flow path and the fluid resistance portion are configured, dimensional variations may occur when a groove or the like serving as the flow path is formed in the plate-like member. For this reason, there is a problem that variation occurs in the cross-sectional area of the flow path and the fluid resistance (fluid resistance value) varies.

Such a problem is more likely to occur as the shape of the flow path becomes complicated and the number of constituent members increases.
As a result, the liquid ejection characteristics of the liquid ejection head are deteriorated (increase in ejection droplet speed variation), and the ejection characteristics are deteriorated due to variations in the circulation characteristics of the liquid. Furthermore, in the case of a liquid discharge head of a type that discharges while circulating a liquid in the flow path, there is a problem that the neglectable time is shortened due to variations in the circulation characteristics of the liquid.

  On the other hand, in order to obtain high liquid discharge accuracy, in addition to the dimensional accuracy of the constituent members, the bonding strength and reliability between the flow path plate and other members (for example, a nozzle plate and a vibration plate) are also required. In general, an adhesive is used for joining, but the adhesive may protrude, and there is a possibility that the cross-sectional area of the flow path may vary due to the difference in the amount of protrusion.

  In Patent Document 1, the partition walls and the diaphragm that define the side surfaces of the pressure generating chambers in the juxtaposed direction are joined by a columnar member made of an inorganic material provided in a direction that intersects the juxtaposed direction of the pressure generating chambers. In addition, a liquid ejecting head is disclosed in which an adhesive layer made of resin is formed around a columnar member between a partition wall and a diaphragm. In such an aspect, it is possible to improve the displacement characteristics of the diaphragm by reducing the restraint by the diaphragm of the diaphragm. In addition, by joining the diaphragm and the partition wall with the adhesive layer and the columnar member, it is possible to suppress the occurrence of problems such as peeling due to a decrease in the bonding strength between the diaphragm and the partition wall. Furthermore, since the gap between the diaphragm and the partition wall is defined by the columnar member, it is possible to suppress variation in displacement characteristics due to the protrusion or shortage of the resin.

  Further, in Patent Document 2, the joint surface between the flow path member and the diaphragm is joined by an adhesive, and the diaphragm has a laminated structure in which the number of laminated layers differs depending on the portion, and an opening that can supply liquid to the pressurized liquid chamber The side wall of the flow path member that is in contact with or close to the filter part and the thick part with the largest number of laminated diaphragms do not overlap in the stacking direction. A droplet discharge head is disclosed. With such a configuration, the bonding strength required between the diaphragm and the flow path member is ensured, and the outflow of the adhesive used for bonding is suppressed.

  As described above, when there is a dimensional variation in the members forming the flow channel in the flow channel plate (for example, a variation in partition wall width or partition wall spacing), it is necessary to eliminate variations in the cross-sectional area of the channel. Even in a head that discharges while circulating liquid in the flow path, the ratio of fluid resistance on the liquid supply side and fluid resistance on the liquid discharge side must be kept constant in order to stabilize the amount of liquid circulation. Is effective.

  In the liquid discharge heads described in Patent Document 1 and Patent Document 2, the protrusion of the adhesive used for joining the component members is controlled, but the liquid in the flow channel due to the dimensional variation of the members constituting the flow channel is controlled. It is difficult to suppress the variation in the cross-sectional area (fluid resistance value) in the flow direction, and the variation in the ejection characteristics may not be eliminated.

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid ejection head in which variations in ejection characteristics of droplets ejected from nozzles are reduced regardless of variations in the dimensions of members constituting a flow path.

  In order to solve the above problems, a liquid discharge head according to the present invention includes a nozzle plate on which a plurality of nozzles for discharging droplets are formed, and a partition that partitions at least a plurality of pressure chambers that communicate with the plurality of nozzles. A flow path plate, a vibration plate that covers a surface of the flow path plate that faces the surface covered with the nozzle plate so as to define the pressure chamber, and the vibration plate is vibrated to vibrate the pressure chamber. Drive means for generating a pressure for pressurizing the liquid, and the partition partitioning the pressure chamber is bonded to the periphery of the joint with the nozzle plate and the joint with the diaphragm. The liquid discharge head is characterized in that the amount of adhesive that has a protruding part of the agent and joins the partition wall, the nozzle plate, and the vibration plate varies depending on the width of the partition wall.

  According to the present invention, it is possible to provide a liquid ejection head in which variations in ejection characteristics of droplets ejected from nozzles are reduced regardless of variations in dimensions of members constituting the flow path.

It is sectional drawing along the liquid chamber (pressure generation chamber) longitudinal direction which shows an example of a liquid discharge head. It is a principal part schematic diagram of the cross section along the liquid chamber transversal direction in a liquid discharge head. It is a principal part schematic of the cross section along the liquid chamber plane direction in a liquid discharge head, and is a top view of a pressure chamber part. FIG. 2 is an explanatory side view illustrating the entire configuration of a mechanism unit of an image forming apparatus as an example of an apparatus for ejecting liquid according to the present invention. FIG. 3 is a plan view illustrating a main part of a mechanism unit of an image forming apparatus as an example of an apparatus for ejecting liquid according to the present invention. It is explanatory drawing which shows typically the cross section of the pressure chamber of the liquid discharge head which concerns on this embodiment. It is explanatory drawing which shows typically the cross section of the pressure chamber of the liquid discharge head which concerns on this embodiment. It is explanatory drawing which shows typically the cross section along the pressure chamber plane direction of the liquid discharge head which concerns on this embodiment. It is principal part top explanatory drawing which shows an example of the liquid discharge unit which concerns on this invention. It is front explanatory drawing which shows the other example of the liquid discharge unit which concerns on this invention.

  Hereinafter, a liquid discharge head, a liquid discharge unit, and a device for discharging a liquid according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

The “liquid ejection head” is a functional component that ejects and ejects liquid from a nozzle.
The liquid to be ejected is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, and the viscosity is 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. It is preferable. More specifically, solvents such as water and organic solvents, colorants 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, solutions, suspensions, emulsions, and the like. These include, for example, inkjet inks, surface treatment liquids, components of electronic devices and light emitting devices, and formation of electronic circuit resist patterns. It can be used in applications such as liquids for use, three-dimensional modeling material liquids, and the like.

  As energy generation sources for discharging liquid, piezoelectric actuators (laminated piezoelectric elements and thin film piezoelectric elements), thermal actuators using electrothermal transducers such as heating resistors, electrostatic actuators consisting of a diaphragm and counter electrode are used. To be included. In the present embodiment, an example in which a multilayer piezoelectric element is used will be described, but the present invention is not limited to this.

An example of the liquid discharge head will be described with reference to FIGS.
FIG. 1 is a cross-sectional view along the longitudinal direction of a liquid chamber of a liquid discharge head (inkjet head) to which the present invention can be applied.
FIG. 2 is a schematic view of a main part of a cross section along the lateral direction of the liquid chamber in the liquid discharge head, FIG. 2 (A) is a cross section taken along the line AA in FIG. 1, and FIG. Is an example of a cross-sectional view along the longitudinal direction of the liquid chamber of the liquid discharge head having the flow path plate 2 having a different shape (a shape in which the pressure chamber 2a and the fluid resistance portion 2b penetrate the flow path plate 2) It is.
FIG. 3 is a schematic view of a main part of a cross section along the plane of the liquid chamber in the liquid droplet ejection head, and is a top view of the pressure chamber.

  The liquid discharge head includes a frame 1 formed with an engraving serving as an ink supply port 1b and a common liquid chamber 1a, a fluid resistance portion 2b, a engraving serving as a pressure chamber (pressure generating chamber) 2a, and a communication port 2c communicating with the nozzle 3a. The flow path plate 2 formed with the nozzle, the nozzle plate 3 forming the nozzle 3a, the diaphragm 6 having the island-shaped convex portion 6a, the diaphragm portion 6b, and the ink inlet 6c, and the vibration plate joined via the adhesive layer 7 A laminated piezoelectric element 5 serving as the driving means and a base 4 to which the laminated piezoelectric element 5 is fixed are provided.

  The base 4 is made of a barium titanate ceramic, and the laminated piezoelectric elements 5 are arranged in two rows and joined.

  The laminated piezoelectric element 5 is composed of a lead zirconate titanate (PZT) piezoelectric layer having a thickness of 10 to 50 μm / layer and an internal electrode layer made of silver and palladium (AgPd) having a thickness of several μm / layer alternately. Are stacked. The internal electrode layer is connected to the external electrode at both ends.

  The laminated piezoelectric element 5 is divided on comb teeth by half-cut dicing, and is used as a drive unit 5c and a support unit (non-drive unit) 5d one by one. The length of the outside of the external electrode is limited by machining such as notches so that it is divided by half-cut dicing, and these become a plurality of individual electrodes 5b. The other is not divided by dicing but is conductive and becomes the common electrode 5a.

The FPC 8 is soldered to the individual electrode 5b of the driving unit. Further, the common electrode 5a is provided with an electrode layer at the end of the laminated piezoelectric element, and is wound around and joined to the Gnd electrode of the FPC 8.
A driver IC (not shown) is mounted on the FPC 8 to control application of drive voltage to the drive unit 5c.

The diaphragm 6 is joined to the frame 1 and a thin film diaphragm portion 6b, an island-shaped convex portion (island portion) 6a to be joined to the laminated piezoelectric element 5 to be the driving portion 5c formed at the center portion of the diaphragm portion 6b. A thick film portion including a beam and an opening serving as an ink inflow port 6c are formed by stacking two Ni plating films by an electroforming method.
The diaphragm portion 6b has a thickness of 3 μm and a width of 35 mm (one side).

  A thin film portion 6d having a single diaphragm is provided at a location facing the common liquid chamber 1a to provide a function of absorbing the pressure of the common liquid chamber 1a.

  The island-shaped convex part 6a of the diaphragm 6 and the driving part 5c of the laminated piezoelectric element 5, and the coupling of the diaphragm 6 and the frame 1 are bonded by patterning the adhesive layer 7 including a gap material.

The flow path plate 2 is formed by using a silicon single crystal substrate and patterning the engraving that becomes the fluid resistance portion 2b and the pressure chamber 2a, and the through-hole that becomes the communication port 2c at a position relative to the nozzle 3a by an etching method.
The portion left by etching becomes the partition 2d of the pressure chamber 2a. Further, in this head, a portion for narrowing the etching width is provided, and this is used as the fluid resistance portion 2b.

  The nozzle plate 3 is formed of a metal material, for example, an Ni plating film by an electroforming method, and has a large number of nozzles 3a that are fine discharge ports for causing ink droplets to fly. The inner shape (inner shape) of the nozzle 3a is formed in a horn shape (may be a substantially cylindrical shape or a substantially frustum shape). The diameter of the nozzle 3a is approximately 20 to 35 μm as the diameter on the ink droplet outlet side. The nozzle pitch of each row was 150 dpi.

  The ink ejection surface (nozzle surface side) of the nozzle plate 3 is provided with a water repellent treatment layer that has been subjected to a water repellent surface treatment (not shown). Ink physical properties such as PTFE-Ni eutectoid plating, electrodeposition coating of fluororesin, vapor-deposited fluororesin (for example, fluorinated pitch), baking after solvent application of silicon resin / fluorine resin, etc. A water-repellent treatment film selected according to the above is provided to stabilize the ink droplet shape and flight characteristics so that high-quality image quality can be obtained.

  The frame 1 that forms the engraving that becomes the ink supply port 1b and the common liquid chamber 1a is made by resin molding.

  In the liquid ejection head configured as described above, a drive waveform (pulse voltage of 10 to 50 V) is applied to the drive unit 5c according to the recording signal, thereby causing a displacement in the stacking direction in the drive unit 5c and the diaphragm. The pressure chamber 2a is pressurized through 6 to increase the pressure, and ink droplets are ejected from the nozzle 3a.

  Thereafter, with the completion of ink droplet ejection, the ink pressure in the pressure chamber 2a is reduced, and a negative pressure is generated in the pressure chamber 2a due to the inertia of the ink flow and the discharge process of the drive pulse, and the process proceeds to the ink filling process. . At this time, the ink supplied from the ink tank flows into the common liquid chamber 1a, passes from the common liquid chamber 1a through the ink inlet 6c, passes through the fluid resistance portion 2b, and is filled into the pressure chamber 2a.

  The fluid resistance portion 2b has an effect on the attenuation of the residual pressure vibration after discharge, but becomes resistant to the refilling due to the surface tension. By appropriately selecting the fluid resistance portion, it is possible to balance the attenuation of the residual pressure and the refill time, and to shorten the time (drive cycle) until the transition to the next ink droplet ejection operation.

The liquid discharge head according to the present embodiment will be described with reference to FIGS.
6 and 7 show a cross section perpendicular to the liquid flow direction in the pressure chamber 2a, and FIG. 8 shows a cross section in a direction horizontal to the liquid flow direction in the pressure chamber 2a.
The cross section perpendicular to the liquid flow direction in FIG. 8A corresponds to FIG. 6, and the cross section perpendicular to the liquid flow direction in FIG. 8B corresponds to FIG.

  In the liquid discharge head according to the present embodiment, a nozzle plate 3 on which a plurality of nozzles 3a for discharging droplets are formed, and a partition wall 2d that partitions at least a plurality of pressure chambers 2a communicating with the plurality of nozzles 3a are formed. The flow path plate 2, the vibration plate 6 that covers the surface of the flow path plate 2 that faces the surface covered with the nozzle plate 3 so as to define the pressure chamber 2 a, and the vibration plate 6 are vibrated to vibrate the liquid in the pressure chamber. Drive means (multilayer piezoelectric element) 5 for generating pressure to pressurize the partition wall 2d partitioning the pressure chamber 2a is provided at the periphery of the joint with the nozzle plate 3 and the joint with the diaphragm 6 The amount of the adhesive 9 that joins the partition wall 2d with the nozzle plate 3 and the vibration plate 6 (hereinafter referred to as the coating amount) has a protrusion that protrudes from the adhesive 9 used for joining, and varies depending on the width of the partition wall 2d. It is a discharge head.

Further, the amount of the adhesive 9 applied varies depending on the width Wc in the cross section perpendicular to the liquid flow direction of the pressure chamber 2a defined by the partition 2d. The width Wc is defined by the width of the partition wall 2d or the interval (pitch) between the partition walls 2d.
The application amount of the adhesive 9 used to join the partition wall 2d to the nozzle plate 3 and the diaphragm 6 is larger when the partition width value is larger than the predetermined value and smaller than the predetermined value. Is increasing.

When the partition width value is larger than the predetermined value, the adhesive 9 is applied in such a manner that the amount of the adhesive 9 protruding into the pressure chamber space is smaller than when the partition wall width is smaller than the predetermined value. ing.
The protruding amount of the adhesive 9 is represented by the width Wb of the protruding region shown in FIGS.

  The predetermined value is preferably an average value obtained from the values of the plurality of pressure chambers 2a.

  That is, as shown in FIGS. 6 to 8, when the width Wc of the pressure chamber 2a is larger than the average value of the widths Wc of the plurality of pressure chambers 2a (the interval between the partition walls 2d is large, or the width of the partition walls 2d). Is small), the amount of protrusion Wb of the adhesive 9 into the space of the pressure chamber 2a is large, and when it is small (when the interval between the partition walls 2d is small or the width value of the partition walls 2d is large) The amount Wb of the agent 9 protruding into the pressure chamber 2a is small.

In order to realize the above configuration, it is necessary to control the coating amount or the protruding amount Wb of the adhesive 9 according to the width Wc of the pressure chamber 2a (the interval between the partition walls 2d or the width of the partition walls 2d).
As a control method, for example, a digital printing method capable of controlling the application position and the application amount using an inkjet method, a micro dispenser method, or the like can be given.
Examples of the method for measuring the width Wc of the pressure chamber 2a (the interval between the partition walls 2d or the width of the partition walls 2d) include optical observation using a CCD and length measurement using a laser.

  Based on the information obtained by measuring the width Wc of the pressure chamber 2a (the interval between the partition walls 2d or the width of the partition walls 2d) in advance, a reference value (for example, all the pressure chambers 2a on the same flow path plate) It is possible to realize the above-described configuration by calculating the average value of the width Wc) and controlling the amount of adhesive 9 applied to each partition wall 2d and the amount of protrusion Wb in accordance with the reference value. it can.

The reference for the coating amount and the protruding amount Wb of the adhesive 9 is the vertical sectional area of the pressure chamber 2a in the liquid flow direction, and the bonding is performed so that the sectional area is constant regardless of the width of the partition wall 2d. It is preferable to control the amount of the agent 9.
As for the cross-sectional area, for example, a method of calculating from an image obtained by optical observation with a CCD or the like can be used.

  That is, the liquid discharge head of the present embodiment has a plurality of pressure chambers in a cross section in which the cross-sectional area of the space portion excluding the portion where the adhesive 9 protrudes from the pressure chamber 2a is perpendicular to the liquid flow direction. It is almost the same between them.

The flow path plate 2 constituting the liquid discharge head of the present embodiment is further formed with a partition that divides a circulation flow path that communicates with the pressure chamber 2a and collects part of the liquid in the pressure chamber. There may be.
In this case, the flow path plate 2 includes a fluid resistance portion 2b, a pressure chamber 2a, a member in which the supply flow path is formed, and a communication port that communicates the supply flow path and the circulation flow path via the pressure chamber 2a. The structure which laminated | stacked the formed member and the member in which the circulation flow path was formed is mentioned.
As the liquid discharge head in which the circulation channel is formed, for example, the configuration described in Patent Document 3 (Japanese Patent Laid-Open No. 2015-71289) can be employed.

According to the liquid discharge head of the above-described embodiment, it is possible to reduce the variation in the cross-sectional area of the flow channel with respect to the variation in the partition wall width of the flow channel. Even if it exists, the dispersion | variation in the fluid resistance value of the flow path comprised can be reduced.
As a result, variations in the discharge characteristics of the liquid droplets discharged from the nozzles can be reduced, the liquid droplet discharge characteristics can be improved, and a high-performance and high-reliability liquid droplet discharge head can be realized. .

An example of a device for ejecting liquid having the above-described liquid ejection head according to the present invention will be described with reference to FIGS.
FIG. 4 is an explanatory side view for explaining the overall configuration of the apparatus for ejecting liquid, and FIG. 5 is an explanatory plan view of the main part of the apparatus.

  The apparatus for discharging the liquid is a serial type ink jet recording apparatus, and the carriage 33 is slid in the main scanning direction by main and sub guide rods 31 and 32 which are guide members horizontally mounted on the left and right side plates 21A and 21B of the apparatus main body 11. It is held freely and moved and scanned in the direction indicated by arrow D1 in FIG. 5 (carriage main scanning direction) via a timing belt by a main scanning motor (not shown).

  The carriage 33 is provided with recording heads 34a and 34b composed of liquid ejection heads for ejecting ink droplets of yellow (Y), cyan (C), magenta (M), and black (K). A nozzle row composed of a plurality of nozzles is arranged in the sub-scanning direction orthogonal to the main scanning direction, and is mounted with the ink droplet ejection direction facing downward.

Each of the recording heads 34 has two nozzle rows. One nozzle row of the recording head 34a has black (K) droplets, the other nozzle row has cyan (C) droplets, and the recording head 34b has one nozzle row. One nozzle row ejects magenta (M) droplets, and the other nozzle row ejects yellow (Y) droplets.
As the recording head 34, a recording head having a nozzle row of each color in which a plurality of nozzles are arranged on one nozzle surface can be used.

Further, the carriage 33 has sub tanks 35a and 35b as sub tanks as second ink supply units for supplying ink of each color corresponding to the nozzle row of the recording head 34 (referred to as "sub tank 35" when not distinguished). It is equipped with.
In the sub tank 35, ink cartridges (main tanks) 10 y, 10 m, 10 c, and 10 k of various colors that are detachably attached to the cartridge loading unit 14 are supplied to the sub tanks 35 through the supply tubes 36 of the respective colors by the supply pump unit 24. The recording liquid is replenished and supplied.

  On the other hand, as a paper feeding unit for feeding the papers 42 stacked on the paper stacking unit (pressure plate) 41 of the paper feeding tray 12, a half-moon roller (feeding) that separates and feeds the papers 42 from the paper stacking unit 41 one by one. A separation pad 44 made of a material having a large friction coefficient is provided facing the paper roller 43) and the paper feed roller 43, and the separation pad 44 is urged toward the paper feed roller 43 side.

  In order to feed the paper 42 fed from the paper feeding unit to the lower side of the recording head 34, a guide member 45 for guiding the paper 42, a counter roller 46, a transport guide member 47, and a tip pressure roller. And a holding belt 48 which is a conveying means for electrostatically attracting the fed paper 42 and conveying it at a position facing the recording head 34.

The transport belt 51 is an endless belt, and is configured to wrap around the transport roller 52 and the tension roller 53 and circulate in the belt transport direction (sub-scanning direction).
Further, a charging roller 56 that is a charging unit for charging the surface of the transport belt 51 is provided.

The charging roller 56 is disposed so as to come into contact with the surface layer of the transport belt 51 and to rotate following the rotation of the transport belt 51.
The conveyance belt 51 rotates in a belt conveyance direction indicated by an arrow D2 in FIG. 5 when the conveyance roller 52 is rotationally driven through a timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 34, a separation claw 61 for separating the paper 42 from the conveying belt 51, a paper discharge roller 62, and a spur 63 that is a paper discharge roller. And a paper discharge tray 13 below the paper discharge roller 62.

A duplex unit 71 is detachably mounted on the back surface of the apparatus body 11.
The duplex unit 71 takes in the paper 42 returned by the reverse rotation of the conveyance belt 51, reverses it, and feeds it again between the counter roller 46 and the conveyance belt 51.
The upper surface of the duplex unit 71 is a manual feed tray 72.
Further, a maintenance / recovery mechanism 81 for maintaining and recovering the nozzle state of the recording head 34 is disposed in the non-printing area on one side of the carriage 33 in the scanning direction.

  The maintenance and recovery mechanism 81 includes a cap member (hereinafter referred to as “cap”) 82a and 82b (hereinafter referred to as “cap 82” when not distinguished) and a nozzle surface for capping each nozzle surface of the recording head 34. A wiper member (wiper blade) 83 for discharging, a blank discharge receiver 84 for receiving droplets when performing blank discharge for discharging droplets that do not contribute to recording in order to discharge the thickened recording liquid, and a carriage 33. And a carriage lock 87 for locking.

  A waste liquid tank 100 for storing waste liquid generated by the maintenance recovery operation is mounted on the lower side of the head recovery mechanism 81 in a replaceable manner with respect to the apparatus main body.

  Further, in the non-printing area on the other side of the carriage 33 in the scanning direction, there is an empty space for receiving liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. A discharge receiver 88 is disposed, and the idle discharge receiver 88 includes an opening 89 along the nozzle row direction of the recording head 34.

  In the apparatus for discharging droplets configured as described above, the paper 42 is separated and fed one by one from the paper feed tray 12, and the paper 42 fed substantially vertically upward is guided by the guide 45, and is conveyed by the conveyor belt. 51 and the counter roller 46 are sandwiched and conveyed, and the leading end is guided by the conveying guide 37 and pressed against the conveying belt 51 by the leading end pressing roller 49, and the conveying direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately repeated with respect to the charging roller 56, that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 51 alternates, that is, in a sub-scanning direction that is a circumferential direction. , Plus and minus are alternately charged in a band shape with a predetermined width.

  When the paper 42 is fed onto the conveyance belt 51 charged alternately with plus and minus, the paper 42 is attracted to the conveyance belt 51, and the paper 42 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 51.

Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped paper 42 to record one line, and after the paper 42 is conveyed by a predetermined amount, Record the next line.
Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 13.

  When performing the maintenance and recovery of the nozzles of the recording head 34, the nozzle 33 performs the suction from the nozzles by moving the carriage 33 to a position facing the maintenance and recovery mechanism 81 which is the home position and performing capping by the cap member 82. By performing a maintenance and recovery operation such as an empty discharge operation for discharging droplets that do not contribute to image formation, it is possible to perform image formation by stable droplet discharge.

In the present application, the “apparatus for discharging liquid” is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

This “apparatus for discharging liquid” may include means for feeding, transporting, and discharging a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

For example, as a “liquid ejecting device”, an image forming device that forms an image on paper by ejecting ink, a powder is formed in layers to form a three-dimensional model (three-dimensional model) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid onto the powder layer.

Further, the “apparatus for ejecting liquid” is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

The above-mentioned “applicable liquid” means that the liquid can be attached at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, unless specifically limited, includes everything that the liquid adheres to.
The material of the above-mentioned “material to which liquid can adhere” is not limited as long as liquid such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics can be adhered even temporarily.

  The “liquid” is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, and the viscosity is 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. Preferably there is. More specifically, solvents such as water and organic solvents, colorants 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, solutions, suspensions, emulsions, and the like. These include, for example, inkjet inks, surface treatment liquids, components of electronic devices and light emitting devices, and formation of electronic circuit resist patterns. It can be used in applications such as liquids for use, three-dimensional modeling material liquids, and the like.

  In addition, the “device for ejecting liquid” includes a device in which the liquid ejection head and the device to which the liquid can adhere move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

In addition to the “device for discharging liquid”, a processing liquid coating apparatus for discharging a processing liquid onto a sheet for applying a processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, or a raw material There is an injection granulator for granulating raw material fine particles by spraying a composition liquid dispersed in a solution through a nozzle.

  Note that the terms “image formation”, “recording”, “printing”, “printing”, “printing”, “modeling” and the like in the terms of the present application are all synonymous.

Next, the liquid discharge unit according to the present invention will be described.
A “liquid ejection unit” is a unit in which functional parts and mechanisms are integrated with a liquid ejection head, and is an assembly of parts related to liquid ejection. For example, the “liquid discharge unit” includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head.

  Here, the term “integrated” refers to, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, etc., and one that is held movably with respect to the other. Including. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

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

  In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  Further, as shown in FIG. 9, the liquid ejection head 404 and the scanning movement mechanism 493 are held as a liquid ejection unit by holding the liquid ejection head 404 movably on a guide member 401 that constitutes a part of the scanning movement mechanism 493. Some are integrated. In some cases, the liquid discharge head 404, the carriage 403, and the main scanning movement mechanism 493 are integrated.

  The liquid discharge unit shown in FIG. 9 includes a casing portion composed of side plates 491A and 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage among the members constituting the liquid discharge device described above. 403 and a liquid discharge head 404.

  Also, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. .

As a liquid discharge unit, as shown in FIG. 10, a tube 456 is connected to a liquid discharge head 404 to which a head tank or flow path component 444 is attached, and the liquid discharge head 404 and the supply mechanism are integrated. There is something. The liquid stored in the liquid storage source is supplied to the liquid discharge head via the tube 456.
The flow path component 444 is disposed inside the cover 442. A head tank may be included instead of the flow path component 444. In addition, a connector 443 that is electrically connected to the liquid ejection head 404 is provided above the flow path component 444.

  The main scanning movement mechanism includes a guide member alone. The supply mechanism includes a single tube and a single loading unit.

1 frame 1
1a Common liquid chamber 1a
1b Ink supply port 1b
2 Channel plate 2
2a Pressure chamber (pressure generation chamber) 2a
2b Fluid resistance part 2b
3 Nozzle plate 3
3a Nozzle 3a
4 Base 4
5 Multilayer piezoelectric element 5
5a Common electrode 5a
5b Individual electrode 5b
5c Drive unit 5c
5d Support part (non-drive part) 5d
6 Diaphragm 6
6a Convex part 6a
6b Diaphragm part 6b
6c Ink inlet 6c
7 Adhesive layer 8 FPC
9 Adhesive 11 Image forming apparatus

JP 2010-221434 A JP 2013-224007 A Japanese Patent Laying-Open No. 2015-71289

Claims (8)

A nozzle plate formed with a plurality of nozzles for discharging droplets;
A flow path plate in which a partition wall defining a plurality of pressure chambers communicating with at least the plurality of nozzles is formed;
A diaphragm that covers a surface of the flow path plate that faces the surface covered with the nozzle plate so as to define the pressure chamber;
Drive means for generating a pressure to pressurize the liquid in the pressure chamber by vibrating the diaphragm,
The partition wall defining the pressure chamber has a protrusion of the adhesive used for bonding at the periphery of the bonded portion with the nozzle plate and the bonded portion with the vibration plate,
The liquid discharge head according to claim 1, wherein an amount of an adhesive for joining the partition, the nozzle plate, and the vibration plate is different depending on a width of the partition.   When the width value of the partition wall is larger than a predetermined value, the adhesive is applied in such a manner that the amount of the adhesive protruding into the pressure chamber space is smaller than when the width is smaller than the predetermined value. The liquid discharge head according to claim 1.   The liquid ejection head according to claim 2, wherein the predetermined value is an average value of the plurality of pressure chambers.   The cross-sectional area of the space portion excluding the protruding portion of the adhesive in the pressure chamber is substantially the same among the plurality of pressure chambers in one cross section in a direction perpendicular to the liquid flow direction. The liquid discharge head according to claim 1.   5. The partition plate according to claim 1, further comprising a partition wall that defines a circulation channel that communicates with the pressure chamber and collects part of the liquid in the pressure chamber. Liquid discharge head.   The liquid discharge head according to claim 1, wherein the flow path plate is made of silicon.   A liquid discharge unit comprising the liquid discharge head according to claim 1.   An apparatus for ejecting liquid, comprising the liquid ejection head according to claim 1.