JP7087303B2 - Cap device and liquid injection device - Google Patents

Description

The present invention relates to a cap device and a liquid injection device.

As an example of the liquid injection device, there is a fluid injection device including a moisturizing cap for moisturizing a nozzle for injecting a fluid and a moisturizing liquid supply device for supplying the moisturizing liquid to the moisturizing cap (for example, Patent Document 1). ).

Japanese Unexamined Patent Publication No. 2009-101634

When the inside of the moisturizing cap covering the nozzle is sealed, the pressure changes with environmental changes such as an increase in temperature, and the gas-liquid interface (meniscus) formed in the nozzle may be broken. An object of the present invention is to provide a cap device and a liquid injection device capable of reducing pressure fluctuations in a space for moisturizing a nozzle.

The cap device for solving the above problems is a cap device capable of forming a space surrounding the opening of the nozzle when it comes into contact with a liquid injection head having a nozzle for injecting a liquid, and has a recess forming the space and a recess. A humidifying chamber to which a humidifying fluid for humidifying the space is supplied, and a partition wall having gas permeability for partitioning the recess and the humidifying chamber are provided, and a part of the wall of the recess is inside the nozzle. It consists of a flexible part that deforms at a pressure smaller than the pressure at which the gas-liquid interface formed in the water breaks.

According to this configuration, the partition wall allows the humidifying fluid in the humidifying chamber to permeate into the space where the nozzle opens, so that the humidifying fluid can moisturize the nozzle. When the pressure fluctuates in the space where the nozzle opens, the flexible portion constituting the wall of the recess bends and displaces, so that the destruction of the gas-liquid interface formed in the nozzle is suppressed. In this way, the displacement of the flexible portion can reduce the pressure fluctuation in the space for moisturizing the nozzle.

In the cap device, it is preferable that the partition wall has higher gas permeability than other walls constituting the humidifying chamber.
According to this configuration, the humidifying fluid in the humidifying chamber can be introduced into the recess through the partition wall, and the permeation of the humidifying fluid from other walls constituting the humidifying chamber to the external space can be suppressed.

In the cap device, it is preferable that the partition wall functions as the flexible portion.
According to this configuration, the pressure fluctuation in the space for moisturizing the nozzle can be reduced due to the deflection displacement of the partition wall.

In the cap device, it is preferable that the inner bottom surface of the recess is flat.
According to this configuration, it is easy to clean the inside of the recess.
In the liquid injection device, it is preferable that the humidifying chamber has an atmospheric communication portion that communicates with the atmosphere on a wall different from the partition wall.

According to this configuration, the pressure fluctuation in the humidifying chamber can be reduced by allowing the gas to flow through the atmospheric communication portion. As a result, the deflection displacement of the partition wall due to the pressure fluctuation in the humidifying chamber is suppressed. As a result, it is possible to suppress pressure fluctuations in the recess due to the deflection displacement of the partition wall.

In the liquid injection device, the humidifying chamber has an introduction portion for introducing the humidifying fluid, and a connection flow path connected to the introduction portion and a moisturizing liquid as the humidifying fluid through the connection flow path. It is preferable that the supply mechanism includes a supply mechanism capable of supplying the moisturizing liquid so that a space in which the partition wall is bent and displaced is secured in the humidifying chamber.

According to this configuration, the pressure fluctuation in the humidifying chamber can be reduced due to the bending and displacement of the partition wall. As a result, the deflection displacement of the partition wall due to the pressure fluctuation in the humidifying chamber is suppressed. As a result, it is possible to suppress pressure fluctuations in the recess due to the deflection displacement of the partition wall.

The liquid injection device includes a capillary member having a capillary force arranged so as to extend from the connection flow path into the humidifying chamber, and the supply mechanism has a liquid level of the moisturizing liquid located in the capillary member. As described above, it is preferable to supply the moisturizing liquid.

According to this configuration, foaming of the moisturizer can be suppressed by infiltrating the moisturizer into the capillary member.
In the liquid injection device, the supply mechanism has a moisturizing liquid storage unit capable of storing the moisturizing liquid and a moisturizing liquid accommodating unit capable of accommodating the moisturizing liquid supplied to the moisturizing liquid storage unit. The moisturizing liquid storage unit includes an outlet to which the connection flow path is connected, an introduction port for introducing the moisturizing liquid supplied from the moisturizing liquid storage unit, and a liquid of the moisturizing liquid in the moisturizing liquid storage unit. It is preferable to have a float valve that opens and closes the introduction port according to the change in position.

According to this configuration, by keeping the liquid level of the moisturizer in the moisturizer storage portion constant by the float valve, the liquid level of the moisturizer supplied through the connection flow path can be kept constant.
The liquid injection device for solving the above problems includes a liquid injection head having a nozzle for injecting a liquid, and a cap device capable of forming a space surrounding the opening of the nozzle when in contact with the liquid injection head. The cap device has a recess forming the space, a humidifying chamber to which a humidifying fluid for humidifying the space is supplied, and a partition wall having gas permeability for partitioning the recess and the humidifying chamber. However, a part of the wall of the recess is composed of a flexible portion that is deformed by a pressure smaller than the pressure at which the gas-liquid interface formed in the nozzle is broken.

According to this configuration, the same effect as that of the cap device can be obtained.

The schematic diagram which shows the 1st Embodiment of a liquid injection apparatus. FIG. 3 is a plan view schematically showing the arrangement of the components of the liquid injection device of FIG. The bottom view of the head unit provided in the liquid injection device of FIG. An exploded perspective view of the head unit of FIG. FIG. 3 is a cross-sectional view taken along the line AA'in FIG. The exploded perspective view of the liquid injection head provided in the liquid injection device of FIG. The plan view of the liquid injection head of FIG. FIG. 7 is a cross-sectional view taken along the line BB'in FIG. The enlarged view in the one-dot chain line frame on the right side in FIG. The enlarged view in the one-dot chain line frame on the left side in FIG. The block diagram which shows the electric structure of the liquid injection device of FIG. The plan view of the maintenance unit provided in the liquid injection device of FIG. FIG. 3 is a plan view of a cap device included in the liquid injection device of FIG. FIG. 6 is a cross-sectional view schematically showing the configuration of the cap device of FIG. FIG. 4 is a perspective view of a cap included in the cap device of FIG. Top view of the cap of FIG. An exploded perspective view of the cap of FIG. FIG. 16 is a cross-sectional view taken along the line 18-18. FIG. 16 is a cross-sectional view taken along the line 19-19. The plan view of the cap device provided in the liquid injection device of the second embodiment. FIG. 2 is a perspective view of a cap unit constituting the cap device of FIG. 20. FIG. 2 is a perspective view of a cap and a cap cover constituting the cap device of FIG. 20. A partially enlarged view of a cap holding portion constituting the cap device of FIG. 20. FIG. 20 is a cross-sectional view taken along the line 24-24. FIG. 22 is a cross-sectional view when the cap cover of FIG. 22 is in the cover position. FIG. 6 is a cross-sectional view taken along the line 26-26 of FIG. 20 when the cap cover is in the cover position. FIG. 2 is a cross-sectional view taken along the line 27-27 of FIG. 20 when the cap cover is in the cover position. The perspective view which shows the 1st modification example of a cap device. An exploded perspective view of the cap device of FIG. 28. FIG. 2 is a cross-sectional view showing a second modification of the cap device.

Hereinafter, embodiments of the liquid injection device will be described with reference to the drawings. The liquid injection device of the present embodiment is an inkjet printer that prints on a medium such as recording paper by injecting ink, which is an example of a liquid.

(First Embodiment)
As shown in FIG. 1, the liquid injection device 700 includes a support base 712, a transfer unit 713, a printing unit 720, a drying unit 719, guide shafts 721 and 722, and a housing 701 for accommodating these components. , Equipped with. The support base 712 and the guide shafts 721 and 722 extend in the X-axis direction, which is the width direction of the medium ST. The housing 701 has an operation panel 703 for performing an operation and displaying an operating state.

The transport unit 713 transports the sheet-shaped medium ST. The printing unit 720 ejects droplets toward the conveyed medium ST at the printing position set on the support base 712. The Y-axis direction is the transport direction of the medium ST at the printing position. The drying unit 719 promotes the drying of the liquid attached to the medium ST. The X-axis and the Y-axis intersect the Z-axis. The Z-axis direction of the present embodiment is the gravity direction, which is the liquid injection direction.

The transfer unit 713 includes a transfer roller pair 714a, a guide plate 715a and a supply reel 716a arranged upstream from the support base 712, and a transfer roller pair 714b, a guide plate 715b and arranged downstream from the support base 712 in the transfer direction. The take-up reel 716b and the like are provided. The transfer unit 713 includes a transfer motor 794 that rotates the transfer roller pairs 714a and 714b.

The medium ST is unwound from the roll sheet RS wound in a roll shape on the supply reel 716a. When the transfer roller pairs 714a and 714b rotate while sandwiching the medium ST, the medium ST is conveyed along the surfaces of the guide plate 715a, the support base 712, and the guide plate 715b. The printed medium ST is wound on the take-up reel 716b.

The printing unit 720 includes a carriage 723 supported by guide shafts 721 and 722, and a carriage motor 748. Driven by the carriage motor 748, the carriage 723 reciprocates above the support base 712 along the guide shafts 721 and 722.

The liquid injection device 700 includes a plurality of supply tubes 726 that can be deformed following the reciprocating carriage 723, and a connection portion 726a attached to the carriage 723. The upstream end of the supply tube 726 is connected to the liquid supply source 702 and the downstream end of the supply tube 726 is connected to the connection 726a. The liquid supply source 702 may be, for example, a tank for storing the liquid, or may be a cartridge that can be attached to and detached from the housing 701.

The printing unit 720 has two liquid injection heads 1 (1A, 1B), a liquid supply path 727, a storage unit 730, and a storage unit holding body 725 that holds the storage unit 730 as components held by the carriage 723. And a flow path adapter 728 connected to the storage unit 730. The liquid injection heads 1A and 1B are held in the lower part of the carriage 723, and the storage portion 730 is held in the upper part of the carriage 723. The liquid supply path 727 supplies the liquid supplied from the liquid supply source 702 to the liquid injection heads 1A and 1B.

The storage unit 730 temporarily stores the liquid between the liquid supply path 727 and the liquid injection head 1. The storage unit 730 is provided at least for each type of liquid. When the liquid injection device 700 includes a plurality of storage units 730 and stores color inks having different colors in the plurality of storage units 730, color printing becomes possible.

The ink colors include, for example, cyan, magenta, yellow, black, and white. Color printing may be performed with four colors of cyan, magenta, yellow, and black, or may be performed with three colors of cyan, magenta, and yellow. Further, at least one of light cyan, light magenta, light yellow, orange, green, and gray may be further added to the three colors of cyan, magenta, and yellow. These inks may contain preservatives.

The white ink can be used for underprint printing (also referred to as solid printing or fill printing) before color printing when printing on a medium ST which is a transparent or translucent film or a dark color medium ST.

The storage unit 730 includes a differential pressure valve 731 provided in the middle of the liquid supply path 727. The differential pressure valve 731 is a so-called pressure reducing valve. That is, the differential pressure valve 731 opens when the liquid is consumed by the liquid injection head 1 and the hydraulic pressure of the liquid supply path 727 between the differential pressure valve 731 and the liquid injection head 1 falls below a predetermined negative pressure lower than the atmospheric pressure. Allows the flow of liquid from the reservoir 730 toward the liquid injection head 1. The differential pressure valve 731 closes when the liquid pressure in the liquid supply path 727 between the differential pressure valve 731 and the liquid injection head 1 returns to the predetermined negative pressure due to the flow of the liquid, and stops the flow of the liquid. The differential pressure valve 731 does not open even if the liquid pressure in the liquid supply path 727 between the differential pressure valve 731 and the liquid injection head 1 becomes high. Therefore, the differential pressure valve 731 functions as a one-way valve (check valve) that allows the liquid to flow from the storage unit 730 to the liquid injection head 1 and suppresses the flow of the liquid in the opposite direction.

The liquid supply path 727 has a supply tube 727a to which the upstream end is connected to the connection portion 726a. The downstream end of the supply tube 727a is connected to the flow path adapter 728 at a position above the reservoir 730. The liquid is supplied to the storage unit 730 through the supply tube 726, the supply tube 727a, and the flow path adapter 728 in this order.

The drying unit 719 includes a heat generating mechanism 717 and a blowing mechanism 718. The heat generating mechanism 717 is arranged above the carriage 723. The liquid injection head 1 ejects droplets onto the medium ST stopped on the support 712 while the carriage 723 is reciprocating between the heat generation mechanism 717 and the support 712.

The heat generation mechanism 717 includes a heat generation member 717a extending in the X-axis direction and a reflector 717b. The heat generating member 717a is, for example, an infrared heater. The heat generation mechanism 717 emits heat such as infrared rays (for example, radiant heat) from the heat generation member 717a to heat the medium ST in the area indicated by the arrow of the alternate long and short dash line in FIG. The blower mechanism 718 blows air into the area heated by the heat generation mechanism 717 to promote the drying of the medium ST.

The carriage 723 includes a heat shield member 729 that shields heat transfer from the heat generation mechanism 717 between the storage unit 730 and the heat generation mechanism 717. The heat shield member 729 is made of a metal material having good thermal conductivity, such as stainless steel or aluminum. The heat shield member 729 preferably covers at least the upper surface of the storage portion 730.

As shown in FIG. 2, the liquid injection heads 1A and 1B are arranged at the lower part of the carriage 723 so as to be separated by a predetermined distance in the X-axis direction and by a predetermined distance in the Y-axis direction. The carriage 723 holds the temperature sensor 711 at a position between the liquid injection heads 1A and 1B in the X-axis direction.

The moving region in which the liquid injection heads 1A and 1B can move in the X-axis direction includes an injection region PA in which printing is performed on the medium ST, and maintenance regions RA and LA outside the injection region PA. The maintenance areas RA and LA are located on both outer sides of the injection area PA in the X-axis direction. The injection region PA is a region in which the liquid injection heads 1A and 1B can inject droplets with respect to the medium ST having the maximum width. When the print unit 720 has a borderless printing function, the injection region PA is slightly wider in the X-axis direction than the medium ST having the maximum width. The heating region in which the heat generation mechanism 717 (see FIG. 1) heats the medium ST overlaps with the injection region PA.

The liquid injection device 700 includes a maintenance unit 710 for maintaining the liquid injection head 1. The maintenance unit 710 includes a cap device 800 arranged in the maintenance area LA, a wiping mechanism 750 arranged in the maintenance area RA, a liquid receiving mechanism 751 and a cap mechanism 752. Above the cap mechanism 752 is the home position HP of the liquid injection heads 1A and 1B. The home position HP is the starting point of the outward movement of the liquid injection heads 1A and 1B.

<About the configuration of the head unit>
Next, the configuration of the head unit 2 will be described in detail.
One liquid injection head 1 has a plurality of (four in this embodiment) head units 2 (see FIG. 6). The head unit 2 is provided for each type of liquid.

As shown in FIG. 3, one head unit 2 has a plurality of nozzles 21 for ejecting droplets. A large number (for example, 180) of nozzles 21 arranged at regular intervals in one direction (Y-axis direction in this embodiment) constitute a nozzle row NL. In the present embodiment, one liquid injection head 1 is provided with two rows of nozzle rows NL arranged in the X-axis direction. Two nozzle rows NL that are lined up close to each other are called a nozzle group.

In one liquid injection head 1, four nozzle groups (a total of eight rows of nozzle rows NL) are arranged at regular intervals in the X-axis direction. When the positions of the nozzles 21 are projected in the X-axis direction, the two liquid injection heads 1 have the same distance between the nozzles 21 at the end of each nozzle row NL as the nozzles 21 constituting one nozzle row NL. The position in the Y-axis direction is adjusted so as to line up with.

As shown in FIG. 4, the head unit 2 includes a head main body 11 and a flow path forming member 40 fixed to the upper surface side of the head main body 11. The head main body 11 includes a protective substrate 30, a flow path forming substrate 10, a communication plate 15, a nozzle plate 20, and a compliance substrate 45, which are stacked in order from the side closest to the flow path forming member 40. The communication plate 15 is provided on the lower surface side of the flow path forming substrate 10. The protective substrate 30 is provided on the upper side of the flow path forming substrate 10. The nozzle plate 20 is provided on the lower surface side of the communication plate 15. The compliance board 45 is provided on the surface side of the communication plate 15 where the nozzle plate 20 is provided.

As the flow path forming substrate 10, a metal such as stainless steel or Ni, a ceramic material typified by ZrO ₂ or Al ₂ O ₃ , a glass ceramic material, an oxide such as MgO or LaAlO ₃ can be used. In the present embodiment, the flow path forming substrate 10 is made of a silicon single crystal substrate.

As shown in FIG. 5, a plurality of pressure chambers 12 partitioned by partition walls are formed on the flow path forming substrate 10. The pressure chamber 12 is arranged above the nozzle 21. The flow path forming substrate 10 is provided with a supply path or the like at one end of the pressure chamber 12 in the Y-axis direction, which has a narrower opening area than the pressure chamber 12 and imparts flow path resistance of the liquid flowing into the pressure chamber 12. May be.

As shown in FIGS. 4 and 5, the nozzle plate 20 has holes constituting the nozzle 21. The downstream end of the nozzle 21 opens in the nozzle surface 20a, which is the lower surface of the nozzle plate 20.

The communication plate 15 is provided with a nozzle communication passage 16 that communicates the pressure chamber 12 and the nozzle 21. The communication plate 15 has a larger flat area than the flow path forming substrate 10, and the nozzle plate 20 has a smaller flat area than the flow path forming substrate 10. By providing the communication plate 15, the nozzle 21 of the nozzle plate 20 and the pressure chamber 12 can be separated from each other. Therefore, the liquid in the pressure chamber 12 is less likely to thicken due to the evaporation of water in the liquid from the nozzle 21. Become. Further, since the nozzle plate 20 only needs to cover the opening of the nozzle communication passage 16 that communicates the pressure chamber 12 and the nozzle 21, the area of the nozzle plate 20 can be made relatively small, and the cost can be reduced. can.

As shown in FIG. 5, the communication plate 15 is provided with a first manifold portion 17 constituting a common liquid chamber 100 and a second manifold portion 18 (throttle flow path, orifice flow path). The first manifold portion 17 penetrates the communication plate 15 in the thickness direction (the Z-axis direction which is the stacking direction between the communication plate 15 and the flow path forming substrate 10). The second manifold portion 18 opens to the nozzle plate 20 side of the communication plate 15 without penetrating the communication plate 15 in the thickness direction.

The communication plate 15 is provided with a supply communication passage 19 that communicates with one end of the pressure chamber 12 in the Y-axis direction independently for each pressure chamber 12. The supply communication passage 19 communicates the second manifold portion 18 and the pressure chamber 12.

A metal such as stainless steel or nickel (Ni), ceramics such as zirconium (Zr), or the like can be used to form the communication plate 15. The communication plate 15 is preferably made of a material having the same coefficient of linear expansion as that of the flow path forming substrate 10. When a material having a coefficient of linear expansion significantly different from that of the flow path forming substrate 10 is used as the communication plate 15, the flow path forming substrate 10 and the communication plate 15 may be warped by being heated or cooled. In the present embodiment, the same material as the flow path forming substrate 10, that is, a silicon single crystal substrate, is used as the communication plate 15, and warpage due to heat, cracking or peeling due to heat, etc. are suppressed.

For forming the nozzle plate 20, for example, a metal such as stainless steel (SUS), an organic substance such as a polyimide resin, a silicon single crystal substrate, or the like can be used. When a silicon single crystal substrate is used as the nozzle plate 20, the linear expansion coefficients of the nozzle plate 20 and the communication plate 15 become the same. This makes it possible to suppress warpage due to heat, cracks or peeling due to heat, and the like.

The diaphragm 50 is arranged on the side of the flow path forming substrate 10 opposite to the communication plate 15. In the present embodiment, as the diaphragm 50, an elastic film 51 made of silicon oxide provided on the flow path forming substrate 10 side and an insulator film 52 made of zirconium oxide provided on the elastic film 51 are provided. There is. The liquid flow path of the pressure chamber 12 or the like is formed by anisotropic etching the flow path forming substrate 10 from one side (the side to which the nozzle plate 20 is joined), and the liquid flow of the pressure chamber 12 or the like. The other side of the path is defined by an elastic film 51.

An actuator 130, which is a pressure generating means of the present embodiment, is provided on the diaphragm 50 of the flow path forming substrate 10. The actuator 130 is, for example, a piezoelectric actuator. The actuator 130 has a first electrode 60, a piezoelectric layer 70, and a second electrode 80.

Generally, one of the electrodes of the actuator 130 is used as a common electrode, and the other electrode is patterned for each pressure chamber 12. In the present embodiment, the first electrode 60 is continuously provided over a plurality of actuators 130 to be a common electrode, and the second electrode 80 is independently provided for each actuator 130 to be an individual electrode. Of course, there is no problem even if this is reversed due to the convenience of the drive circuit or wiring.

In the above-mentioned example, the diaphragm 50 is exemplified by the elastic film 51 and the insulator film 52, but the diaphragm 50 is not limited to this, of course. For example, either the elastic film 51 or the insulator film 52 may be provided as the diaphragm 50, or the first electrode may be provided without the elastic film 51 and the insulator film 52 as the diaphragm 50. Only 60 may act as a diaphragm. Further, the actuator 130 itself may substantially serve as a diaphragm.

The piezoelectric layer 70 is made of a piezoelectric material of an oxide having a polarized structure, and can be made of, for example, a perovskite-type oxide represented by the general formula ABO ₃ , a lead-based piezoelectric material containing lead or a non-lead-free material. A lead-based piezoelectric material or the like can be used.

The tip of the lead electrode 90 is connected to the second electrode 80, which is an individual electrode of the actuator 130. The lead electrode 90 is pulled out from the vicinity of the end opposite to the supply passage 19 and extends onto the diaphragm 50. The lead electrode 90 is made of, for example, gold (Au) or the like.

A wiring board 121 is connected to the other end of the lead electrode 90. As the wiring board 121, a flexible sheet-like one, for example, a COF substrate or the like can be used. The wiring board 121 is provided with a drive circuit 120 for driving the actuator 130.

As shown in FIG. 6, a second terminal row 123 is formed on one surface of the wiring board 121. The second terminal row 123 is composed of a plurality of second terminals (wiring terminals) 122 arranged in the Y-axis direction. The wiring board 121 is not limited to the COF board, and may be FFC, FPC, or the like.

As shown in FIG. 5, a protective substrate 30 having substantially the same size as the flow path forming substrate 10 is bonded to the surface of the flow path forming substrate 10 on the actuator 130 side. The protective substrate 30 has a holding portion 31 which is a space for protecting the actuator 130.

The holding portion 31 has a concave shape that opens toward the flow path forming substrate 10 without penetrating the protective substrate 30 in the Z-axis direction, which is the thickness direction. The holding portion 31 is independently provided for each row composed of the actuators 130 arranged side by side in the X-axis direction. That is, the holding portion 31 is provided so as to accommodate rows of the actuators 130 arranged side by side in the X-axis direction, and each row of the actuators 130, that is, two are arranged side by side in the Y-axis direction. Such a holding portion 31 may have a space that does not hinder the movement of the actuator 130, and the space may or may not be sealed.

The protective substrate 30 has a through hole 32 penetrating in the Z-axis direction, which is the thickness direction. The through hole 32 is provided between the two holding portions 31 juxtaposed in the Y-axis direction over the X-axis direction, which is the juxtaposed direction of the plurality of actuators 130. That is, the through hole 32 is an opening having long sides in the juxtaposed direction of the plurality of actuators 130. The base end of the lead electrode 90 is extended so as to be exposed in the through hole 32, and the lead electrode 90 and the wiring board 121 are electrically connected in the through hole 32.

As the protective substrate 30, it is preferable to use a material having substantially the same coefficient of thermal expansion as that of the flow path forming substrate 10, such as glass or ceramic material. In this embodiment, it is formed by using a silicon single crystal substrate made of the same material as the flow path forming substrate 10. The method of joining the flow path forming substrate 10 and the protective substrate 30 is not particularly limited. For example, in the present embodiment, the flow path forming substrate 10 and the protective substrate 30 are joined via an adhesive (not shown). There is.

The head unit 2 includes a flow path forming member 40. The flow path forming member 40 defines a common liquid chamber 100 communicating with a plurality of pressure chambers 12 together with the head main body 11. The flow path forming member 40 has substantially the same shape as the above-mentioned communication plate 15 in a plan view, and is joined to the protective substrate 30 and also to the above-mentioned communication plate 15.

Specifically, the flow path forming member 40 has a recess 41 having a depth for accommodating the flow path forming substrate 10 and the protective substrate 30 on the protective substrate 30 side. The recess 41 has a wider opening area than the surface of the protective substrate 30 joined to the flow path forming substrate 10. Then, the opening surface of the recess 41 on the nozzle plate 20 side is sealed by the communication plate 15 in a state where the flow path forming substrate 10 and the like are housed in the recess 41. As a result, a third manifold portion 42 is defined on the outer peripheral portion of the flow path forming substrate 10 by the flow path forming member 40 and the head main body 11. The first manifold portion 17 and the second manifold portion 18 provided in the communication plate 15, and the third manifold portion 42 defined by the flow path forming member 40 and the head main body 11 are common to this embodiment. The liquid chamber 100 is configured.

That is, the common liquid chamber 100 includes a first manifold portion 17, a second manifold portion 18, and a third manifold portion 42. Further, the common liquid chamber 100 of the present embodiment is arranged on both outer sides of the two rows of pressure chambers 12 in the Y-axis direction, and two common liquid chambers provided on both outer sides of the two rows of pressure chambers 12. The 100s are independently provided in the head unit 2 so as not to communicate with each other. That is, one common liquid chamber 100 is provided in communication with each row of the pressure chambers 12 of the present embodiment (rows arranged side by side in the X-axis direction). In other words, a common liquid chamber 100 is provided for each nozzle row NL. Of course, the two common liquid chambers 100 may communicate with each other.

As described above, the flow path forming member 40 is a member that forms the common liquid chamber 100, and has an introduction port 44 that communicates with the common liquid chamber 100. That is, the introduction port 44 is an opening that serves as an inlet for introducing the liquid supplied to the head main body 11 into the common liquid chamber 100. As the material of the flow path forming member 40, for example, resin, metal, or the like can be used. If the material of the flow path forming member 40 is a resin material, mass production can be performed at low cost.

The flow path forming member 40 is provided with a connection port 43 that communicates with the through hole 32 of the protective substrate 30. A wiring board 121 is inserted through the connection port 43. The upper end portion of the wiring board 121 extends in the penetration direction of the through hole 32 and the connection port 43, that is, in the Z-axis direction, on the side opposite to the droplet injection direction.

A compliance board 45 is provided on the surface of the communication plate 15 where the first manifold portion 17 and the second manifold portion 18 open. The compliance substrate 45 has substantially the same size as the communication plate 15 described above in a plan view, and is provided with a first exposed opening 45a that exposes the nozzle plate 20. Then, with the compliance board 45 exposing the nozzle plate 20 by the first exposed opening 45a, the openings of the first manifold portion 17 and the second manifold portion 18 on the nozzle surface 20a side are sealed. That is, the compliance board 45 defines a part of the common liquid chamber 100.

The compliance substrate 45 includes a sealing film 46 and a fixed substrate 47. The sealing film 46 is made of a flexible film-like thin film (for example, a thin film having a thickness of 20 μm or less formed of polyphenylene sulfide (PPS) or the like). The fixed substrate 47 is formed of a hard material such as a metal such as stainless steel (SUS). Since the region of the fixed substrate 47 facing the common liquid chamber 100 is an opening 48 completely removed in the thickness direction, only one surface of the common liquid chamber 100 is a flexible sealing film 46. It is a compliance part 49 which is a flexible part sealed with. In the present embodiment, one compliance unit 49 is provided corresponding to one common liquid chamber 100. That is, in the present embodiment, since two common liquid chambers 100 are provided, two compliance portions 49 are provided on both sides in the Y-axis direction with the nozzle plate 20 interposed therebetween.

In the head unit 2, when the droplet is ejected, the liquid is taken in through the introduction port 44, and the inside of the flow path from the common liquid chamber 100 to the nozzle 21 is filled with the liquid. Then, according to the signal from the drive circuit 120, a voltage is applied to the actuator 130 corresponding to the pressure chamber 12, so that the diaphragm 50 is flexed and deformed together with the actuator 130. As a result, the pressure in the pressure chamber 12 increases, and the droplets are ejected from the nozzle 21 communicating with the pressure chamber 12.

<About the configuration of the liquid injection head>
Next, the liquid injection head 1 will be described in detail.
As shown in FIG. 6, the liquid injection head 1 includes four head units 2, a flow path member 200 that holds the head unit 2, a head substrate 300 that is held by the flow path member 200, and a flexible wiring board. A wiring board 121, which is an example, is provided. The flow path member 200 includes a holder member that supplies a liquid to the head unit 2.

FIG. 7 shows a plan view of the liquid injection head 1 in which the seal member 230 and the upstream flow path member 210 are not shown.
As shown in FIG. 8, the flow path member 200 is arranged between the upstream flow path member 210, the downstream flow path member 220 which is an example of the holder member, and the upstream flow path member 210 and the downstream flow path member 220. The seal member 230 is provided.

The upstream flow path member 210 has an upstream flow path 500 that serves as a flow path for the liquid. In the present embodiment, the upstream flow path member 210 is configured by stacking a first upstream flow path member 211, a second upstream flow path member 212, and a third upstream flow path member 213 in the Z-axis direction. .. The first upstream flow path member 211, the second upstream flow path member 212, and the third upstream flow path member 213 are provided with a first upstream flow path 501, a second upstream flow path 502, and a third upstream flow path 503, respectively. .. The upstream flow path 500 is configured by connecting the first upstream flow path 501, the second upstream flow path 502, and the third upstream flow path 503.

The upstream flow path member 210 is not limited to such an embodiment, and may be a single member or may be composed of two or more members. Further, the stacking direction of the plurality of members constituting the upstream flow path member 210 is not particularly limited, and may be the X-axis direction or the Y-axis direction.

The first upstream flow path member 211 has a connection portion 214 connected to a liquid container such as a tank or a cartridge for storing the liquid on the side opposite to the downstream flow path member 220. In the present embodiment, the connecting portion 214 is formed to protrude like a needle. A liquid accommodating body such as a cartridge may be directly connected to the connecting portion 214, or a liquid accommodating portion such as a tank may be connected via a supply pipe such as a tube.

The first upstream flow path member 211 is provided with a first upstream flow path 501. The first upstream flow path 501 opens at the top surface of the connection portion 214 and extends in the Z-axis direction or in a direction orthogonal to the Z-axis direction, that is, depending on the position of the second upstream flow path 502 described later. It is composed of a flow path or the like extending in a plane including the X-axis direction and the Y-axis direction. Further, a guide wall 215 (see FIG. 6) for positioning the liquid holding portion is provided around the connecting portion 214 of the first upstream flow path member 211.

The second upstream flow path member 212 has a second upstream flow path 502 that is fixed on the side opposite to the connection portion 214 of the first upstream flow path member 211 and communicates with the first upstream flow path 501. Further, on the downstream side (third upstream flow path member 213 side) of the second upstream flow path 502, a first liquid pool portion 502a having a wider inner diameter than the second upstream flow path 502 is provided.

The third upstream flow path member 213 is provided on the opposite side of the second upstream flow path member 212 from the first upstream flow path member 211. Further, the third upstream flow path member 213 is provided with a third upstream flow path 503. The opening portion of the third upstream flow path 503 on the second upstream flow path 502 side is a second liquid pool portion 503a widened according to the first liquid pool portion 502a. A filter 216 for removing foreign matter such as air bubbles contained in the liquid is provided in the opening portion of the second liquid pool portion 503a (between the first liquid pool portion 502a and the second liquid pool portion 503a). .. As a result, the liquid supplied from the second upstream flow path 502 (first liquid pool portion 502a) is supplied to the third upstream flow path 503 (second liquid pool portion 503a) via the filter 216.

As the filter 216, for example, a mesh-like body such as a wire mesh or a resin mesh, a porous body, or a metal plate having fine through holes can be used. Specific examples of the mesh-like body include a metal mesh filter, a metal fiber, a felt-like thin wire such as SUS, a compression-sintered metal sintered filter, an electroforming metal filter, and an electron beam processed metal. A filter, a laser beam processed metal filter, or the like can be used.

As the property of the filter 216, it is preferable that the bubble point pressure does not fluctuate, and a filter having a high-definition hole diameter is suitable. The "bubble point pressure" refers to the pressure at which the meniscus formed by opening the filter breaks. The filtration particle size of the filter 216 is preferably smaller than the diameter of the nozzle opening, for example, when the nozzle opening is circular, in order to prevent foreign matter in the liquid from reaching the nozzle opening.

When a stainless steel mesh filter is used as the filter 216, it is preferable to prevent foreign matter in the liquid from reaching the nozzle opening. Therefore, the mesh filter is preferably a twill weave (filtration particle size 10 um) whose filtration particle size is smaller than the nozzle opening (for example, when the nozzle opening is circular, the diameter of the nozzle opening is 20 μm). In this case, the bubble point pressure generated by the liquid (surface tension 28 mN / m) is 3 to 5 kPa. Further, the bubble point pressure generated in the liquid when the twill weave (filtration particle size 5 um) is adopted is 0 to 15 kPa.

The third upstream flow path 503 is branched into two on the downstream side (opposite side of the second upstream flow path) from the second liquid pool portion 503a, and the third upstream flow path 503 is the third upstream flow path. The first discharge port 504A and the second discharge port 504B are opened on the surface of the member 213 on the downstream flow path member 220 side. Hereinafter, when the first discharge port 504A and the second discharge port 504B are not distinguished, they are referred to as a discharge port 504.

That is, the upstream flow path 500 corresponding to one connection portion 214 has a first upstream flow path 501, a second upstream flow path 502, and a third upstream flow path 503, and the upstream flow path 500 is a downstream flow path member. It opens as two discharge ports 504 (first discharge port 504A and second discharge port 504B) on the 220 side. In other words, the two discharge ports 504 (first discharge port 504A and second discharge port 504B) are provided so as to communicate with a common flow path.

On the downstream flow path member 220 side of the third upstream flow path member 213, a third protrusion 217 that protrudes toward the downstream flow path member 220 side is provided. The third protrusion 217 is provided for each third upstream flow path 503, and the discharge port 504 is provided at the tip surface of the third protrusion 217.

The first upstream flow path member 211, the second upstream flow path member 212, and the third upstream flow path member 213 provided with such an upstream flow path 500 are integrally laminated by, for example, bonding or welding with an adhesive. Has been done. The first upstream flow path member 211, the second upstream flow path member 212, and the third upstream flow path member 213 can also be fixed with screws, clamps, or the like. However, in order to prevent the liquid from leaking from the connecting portion from the first upstream flow path 501 to the third upstream flow path 503, it is preferable to bond them by adhesion or welding.

In the present embodiment, one upstream flow path member 210 is provided with four connecting portions 214, and one upstream flow path member 210 is provided with four independent upstream flow paths 500. A liquid is supplied to each upstream flow path 500 corresponding to each of the four head units 2. One upstream flow path 500 branches into two, communicates with the downstream flow path 600 described later, and is connected to each of the two introduction ports 44 of the head unit 2.

In the present embodiment, the configuration in which the upstream flow path 500 is branched into two branches downstream of the filter 216 (on the downstream flow path member 220 side) is exemplified, but the present invention is not particularly limited to this, and the upstream flow path 500 is upstream on the downstream side of the filter 216. The flow path 500 may be branched into three or more. Further, one upstream flow path 500 may not be branched downstream of the filter 216.

The downstream flow path member 220 is an example of a holder member having a downstream flow path 600 that is joined to the upstream flow path member 210 and communicates with the upstream flow path 500. The downstream flow path member 220 according to the present embodiment is composed of a first downstream flow path member 240 which is an example of the first member and a second downstream flow path member 250 which is an example of the second member.

The downstream flow path member 220 has a downstream flow path 600 that serves as a flow path for the liquid. The downstream flow path 600 according to the present embodiment is composed of two types of downstream flow paths 600A and downstream flow paths 600B having different shapes.

The first downstream flow path member 240 is a member formed in a substantially flat plate shape. Further, the second downstream flow path member 250 is provided with a first accommodating portion 251 as a recess on the surface on the upstream flow path member 210 side and a second accommodating portion 252 as a recess on the surface opposite to the upstream flow path member 210. It is a member.

The first accommodating portion 251 is sized to accommodate the first downstream flow path member 240. Further, the second accommodating portion 252 is sized to accommodate four head units 2. The second accommodating portion 252 according to the present embodiment can accommodate four head units 2.

The first downstream flow path member 240 is formed with a plurality of first protrusions 241 on the surface on the upstream flow path member 210 side. Each of the first protrusions 241 is provided so as to face the third protrusion 217 provided with the first discharge port 504A among the third protrusions 217 provided on the upstream flow path member 210. In this embodiment, four first protrusions 241 are provided.

The first downstream flow path member 240 is provided with a first flow path 601 that penetrates in the Z-axis direction and opens to the top surface (the surface facing the upstream flow path member 210) of the first protrusion 241. The third protrusion 217 and the first protrusion 241 are joined via a seal member 230, and the first discharge port 504A and the first flow path 601 communicate with each other.

A plurality of second through holes 242 penetrating in the Z-axis direction are formed in the first downstream flow path member 240. Each second through hole 242 is formed at a position through which the second protrusion 253 formed in the second downstream flow path member 250 is inserted. In this embodiment, four second through holes 242 are provided.

The first downstream flow path member 240 is formed with a plurality of first insertion holes 243 through which the wiring board 121 electrically connected to the head unit 2 is inserted. Specifically, each first insertion hole 243 penetrates in the Z-axis direction and communicates with the second insertion hole 255 of the second downstream flow path member 250 and the third insertion hole 302 of the head substrate 300. It is formed. In this embodiment, four first insertion holes 243 are provided corresponding to the wiring boards 121 provided in the four head units 2. Further, the first downstream flow path member 240 is provided with a support portion 245 that protrudes toward the head substrate 300 and has a receiving surface.

The second downstream flow path member 250 is formed with a plurality of second protrusions 253 on the bottom surface of the first accommodating portion 251. Each of the second protrusions 253 is provided so as to face the third protrusion 217 provided with the second discharge port 504B among the third protrusions 217 provided on the upstream flow path member 210. In this embodiment, four second protrusions 253 are provided. Further, the downstream flow path that penetrates the second downstream flow path member 250 in the Z-axis direction and opens to the top surface of the second protrusion 253 and the bottom surface of the second accommodating portion 252 (the surface facing the head unit 2). 600B is provided. The third protrusion 217 and the second protrusion 253 are joined via a seal member 230, and the second discharge port 504B and the downstream flow path 600B communicate with each other.

A plurality of third flow paths 603 penetrating in the Z-axis direction are formed in the second downstream flow path member 250. Each third flow path 603 is open to the bottom surface of the first accommodating portion 251 and the second accommodating portion 252. In this embodiment, four third flow paths 603 are provided.

A plurality of groove portions 254 continuous with the third flow path 603 are formed on the bottom surface of the first accommodating portion 251 of the second downstream flow path member 250. The groove portion 254 is sealed in the first downstream flow path member 240 housed in the first storage section 251 to form the second flow path 602. That is, the second flow path 602 is a flow path defined by the groove portion 254 and the surface of the first downstream flow path member 240 on the side of the second downstream flow path member 250. The second flow path 602 corresponds to the flow path provided between the first member and the second member according to claim.

The second downstream flow path member 250 is formed with a plurality of second insertion holes 255 through which the wiring board 121 electrically connected to the head unit 2 is inserted. Specifically, each of the second insertion holes 255 is formed so as to penetrate in the Z-axis direction and communicate with the first insertion hole 243 of the first downstream flow path member 240 and the connection port 43 of the head unit 2. .. In the present embodiment, four second insertion holes 255 are provided corresponding to the wiring boards 121 provided in the four head units 2.

The downstream flow path 600A is formed by communicating the first flow path 601, the second flow path 602, and the third flow path 603 described above. Here, the second flow path 602 is formed by sealing the groove formed on one surface of the first downstream flow path member 240 with the second downstream flow path member 250. By joining such a first downstream flow path member 240 and a second downstream flow path member 250, the second flow path 602 can be easily formed in the downstream flow path member 220.

The second flow path 602 is an example of a flow path extending in the horizontal direction. The fact that the second flow path 602 extends in the horizontal direction means that a component (vector) in the X-axis direction or the Y-axis direction is included in the extending direction of the second flow path 602. Since the second flow path 602 extends in the horizontal direction, the height of the liquid injection head 1 in the Z-axis direction can be reduced. If the second flow path 602 is tilted with respect to the horizontal direction, the height dimension of the liquid injection head 1 becomes large.

The extending direction of the second flow path 602 is the direction in which the liquid in the second flow path 602 flows. Therefore, the second flow path 602, which is provided in the horizontal direction (direction orthogonal to the Z-axis direction), intersects the gravity direction and the horizontal direction (in-plane direction in the X-axis direction and the Y-axis direction). Including those provided. In the present embodiment, the first flow path 601 and the third flow path 603 are arranged in the Z-axis direction, and the second flow path 602 is arranged in the horizontal direction (Y-axis direction). The first flow path 601 and the third flow path 603 may be arranged in the axial direction intersecting the Z axis.

The downstream flow path 600A is not limited to this, and a flow path other than the first flow path 601, the second flow path 602, and the third flow path 603 may exist. Further, the downstream flow path 600A is not composed of the first flow path 601 and the second flow path 602 and the third flow path 603, but may be composed of one flow path.

As described above, the downstream flow path 600B is formed as a through hole penetrating the second downstream flow path member 250 in the Z-axis direction. Of course, the downstream flow path 600B is not limited to such an embodiment, and may extend in the axial direction intersecting the Z axis, or may be configured by communicating a plurality of flow paths as in the downstream flow path 600A. It may be.

Such a downstream flow path 600A and a downstream flow path 600B are formed one by one for one head unit 2. That is, the downstream flow path member 220 is provided with a total of four sets of the downstream flow path 600A and the downstream flow path 600B.

Of the openings at both ends of the downstream flow path 600A, the opening of the first flow path 601 through which the first discharge port 504A communicates is the first inflow port 610, and the opening of the third flow path 603 that opens into the second accommodating portion 252. Is the first outlet 611.

Of the openings at both ends of the downstream flow path 600B, the opening of the downstream flow path 600B through which the second discharge port 504B communicates is the second inflow port 620, and the opening of the downstream flow path 600B that opens to the second accommodating portion 252 is the first. 2 Outlet 621. Hereinafter, when the downstream flow path 600A and the downstream flow path 600B are not distinguished, they are referred to as the downstream flow path 600.

As shown in FIG. 6, the downstream flow path member 220 (holder member) holds the head unit 2 on the lower side. Specifically, a plurality of (four in this embodiment) head units 2 are accommodated in the second accommodating portion 252 of the downstream flow path member 220.

As shown in FIG. 8, the head unit 2 is provided with two introduction ports 44 each. The first outlet 611 and the second outlet 621 of the downstream flow path 600 (downstream flow path 600A and downstream flow path 600B) are provided in the downstream flow path member 220 according to the opening position of each introduction port 44. ..

Each introduction port 44 of the head unit 2 is aligned so as to communicate with the first outlet 611 and the second outlet 621 of the downstream flow path 600 opened in the bottom surface portion of the second accommodating portion 252. The head unit 2 is fixed to the second accommodating portion 252 by an adhesive 227 provided around each introduction port 44. By fixing the head unit 2 to the second accommodating portion 252 in this way, the first outlet 611 and the second outlet 621 of the downstream flow path 600 and the introduction port 44 communicate with each other, and the liquid flows into the head unit 2. It is supposed to be supplied.

The head substrate 300 is placed on the upper side of the downstream flow path member 220. Specifically, the head substrate 300 is placed on the surface of the downstream flow path member 220 on the upstream flow path member 210 side. The head substrate 300 is a member to which a wiring board 121 is connected and an electrical component such as a circuit or a resistor for controlling the injection operation of the liquid injection head 1 is mounted via the wiring board 121.

As shown in FIG. 6, a plurality of first terminals (electrode terminals) 311 to which the second terminal row 123 of the wiring board 121 is electrically connected are arranged on the surface of the head substrate 300 on the upstream flow path member 210 side. The first terminal row 310 provided is formed. In the present embodiment, the first terminal row 310 is an example of a mounting area electrically connected to the wiring board 121.

The head board 300 is formed with a plurality of third insertion holes 302 through which the wiring board 121 electrically connected to the head unit 2 is inserted. Specifically, each third insertion hole 302 is formed so as to penetrate in the Z-axis direction and communicate with the first insertion hole 243 of the first downstream flow path member 240. In the present embodiment, four third insertion holes 302 are provided corresponding to the wiring boards 121 provided in the four head units 2.

The head substrate 300 is provided with a third through hole 301 penetrating in the Z-axis direction. The third through hole 301 is inserted through the first protrusion 241 of the first downstream flow path member 240 and the second protrusion 253 of the second downstream flow path member 250. In the present embodiment, a total of eight third through holes 301 are provided so as to face the first protrusion 241 and the second protrusion 253.

The shape of the third through hole 301 formed in the head substrate 300 is not limited to the above-described embodiment. For example, a common through hole through which the first protrusion 241 and the second protrusion 253 are inserted may be used as the insertion hole. That is, the head substrate 300 is formed with an insertion hole, a notch, or the like so as not to interfere with the connection between the downstream flow path 600 of the downstream flow path member 220 and the upstream flow path 500 of the upstream flow path member 210. Just do it.

As shown in FIGS. 8, 9 and 10, a seal member 230 is provided between the head substrate 300 and the upstream flow path member 210. As the material of the sealing member 230, a material (elastic material) having liquid resistance to a liquid such as ink used for the liquid injection head 1 and elastically deformable (elastic material), for example, rubber or elastomer may be used. can.

The seal member 230 is a plate-shaped member in which a continuous passage 232 penetrating in the Z-axis direction and a fourth protrusion 231 protruding toward the downstream flow path member 220 are formed. In the present embodiment, eight communication passages 232 and the fourth protrusion 231 are formed corresponding to each upstream flow path 500 and downstream flow path 600.

An annular first recess 233 into which the third protrusion 217 is inserted is provided on the upstream flow path member 210 side of the seal member 230. The first recess 233 is provided at a position facing the fourth protrusion 231.

The fourth protrusion 231 projects toward the downstream flow path member 220, and is provided at a position facing the first protrusion 241 and the second protrusion 253 of the downstream flow path member 220. The top surface of the fourth protrusion 231 (the surface facing the downstream flow path member 220) is provided with a second recess 234 into which the first protrusion 241 and the second protrusion 253 are inserted.

The communication passage 232 penetrates the seal member 230 in the Z-axis direction, and one end thereof opens in the first recess 233 and the other end opens in the second recess 234. Then, between the tip surface of the third protrusion 217 inserted into the first recess 233 and the tip surfaces of the first protrusion 241 and the second protrusion 253 inserted into the second recess 234, the fourth protrusion The portion 231 is held in a state where a predetermined pressure is applied in the Z-axis direction. Therefore, the upstream flow path 500 and the downstream flow path 600 are communicated with each other in a sealed state via the communication passage 232.

A cover head 400 is attached to the second accommodating portion 252 side (lower side) of the downstream flow path member 220. The cover head 400 is a member to which the liquid injection head 1 is fixed and is fixed to the downstream flow path member 220, and is provided with a second exposed opening 401 that exposes the nozzle 21. In the present embodiment, the second exposed opening 401 has a size that exposes the nozzle plate 20, that is, has substantially the same opening as the first exposed opening 45a of the compliance substrate 45.

The cover head 400 is joined to the side of the compliance board 45 opposite to the communication plate 15, and seals the space on the side opposite to the flow path (common liquid chamber 100) of the compliance unit 49. By covering the compliance unit 49 with the cover head 400 in this way, it is possible to prevent the compliance unit 49 from being destroyed even if it comes into contact with the medium ST. Further, it is possible to suppress the liquid from adhering to the compliance unit 49, wipe off the liquid adhering to the surface of the cover head 400 with, for example, a wiper blade, and contaminate the medium ST with the liquid or the like adhering to the cover head 400. Can be suppressed. Although not shown in particular, the space between the cover head 400 and the compliance unit 49 is open to the atmosphere. The cover head 400 may be provided independently for each liquid injection head 1.

<About the electrical configuration of the liquid injection device>
Next, the electrical configuration of the liquid injection device 700 will be described.
As shown in FIG. 11, the liquid injection device 700 includes a control unit 22 that comprehensively controls the components of the liquid injection device 700, and a detector group 150 that monitors the situation inside the liquid injection device 700.

The control unit 22 includes an interface unit 151, a CPU 152, a memory 153, a unit control circuit 154, and a drive circuit 120. The interface unit 151 transmits / receives data between the computer 157, which is an external device, and the liquid injection device 700. The drive circuit 120 generates a drive signal to drive the actuator 130.

The CPU 152 is an arithmetic processing device. The memory 153 is a storage device for securing an area or a work area for storing the program of the CPU 152, and has a storage element such as RAM and EEPROM. The CPU 152 controls the drying unit 719, the transport unit 713, the maintenance unit 710, and the printing unit 720 via the unit control circuit 154 according to the program stored in the memory 153.

The detector group 150 includes, for example, a linear encoder (not shown) for detecting the movement status of the carriage 723, a medium detection sensor (not shown) for detecting the medium ST, and a detection circuit for detecting the residual vibration of the pressure chamber 12. Includes part 156. The detector group 150 outputs the detection result to the CPU 152. The control unit 22 detects the clogging of the nozzle 21 based on the detection result of the detection unit 156. The detection unit 156 may include a piezoelectric element constituting the actuator 130.

<Maintenance unit configuration>
Next, the configuration of the maintenance unit 710 will be described.
As shown in FIG. 12, the maintenance region RA includes a receiving region FA provided with the liquid receiving mechanism 751, a wiping region WA provided with the wiping mechanism 750, and a suction region MA provided with the cap mechanism 752. .. In the maintenance region RA, the receiving region FA is arranged at the position closest to the injection region PA, and the suction region MA is arranged at the position farthest from the injection region PA.

The wiping mechanism 750 includes a wiping member 750a for wiping the liquid injection head 1 and a wiping motor 753. The wiping member 750a of the present embodiment is movable, and the liquid injection head 1 is wiped by the power of the wiping motor 753. Maintenance by wiping like this is called wiping.

The wiping mechanism 750 includes a pair of rails 758 extending in the Y-axis direction by the power of the wiping motor 753, and a movable case 759 supported by the rails 758. The power of the wiping motor 753 is transmitted to the case 759 by a power transmission mechanism (for example, a rack and pinion mechanism) (not shown), and the power reciprocates on the rail 758.

The case 759 rotatably supports a feeding shaft 760, a feeding shaft 760, a pressing roller 765, and a winding shaft 761 arranged at predetermined intervals in the Y-axis direction. The case 759 has an opening (not shown) above the pressing roller 765.

The feeding shaft 760 supports a feeding roll 763 in which an unused cloth sheet 762 is wound in a cylindrical shape, and a winding shaft 761 supports a winding roll 764 formed by a used cloth sheet 762. The pressing roller 765 pushes up the cloth sheet 762 between the feeding roll 763 and the winding roll 764 and projects it from the opening.

The case 759 moves outward from the retracted position shown in FIG. 12 in the Y-axis direction due to the normal rotation of the wiping motor 753, and reaches the wiping position. After that, the case 759 moves back from the wiping position to the evacuation position due to the reversal of the wiping motor 753. In the process of moving the case 759 on the outward path, the wiping member 750a wipes the liquid injection head 1. The case 759 may move in the outward direction in the direction opposite to the Y-axis direction and move in the return path in the Y-axis direction with the position shown in FIG. 12 as the folding position.

When the outward movement of the case 759 is completed, the power transmission mechanism switches the output destination of the driving force of the wiping motor 753 to the take-up shaft 761, and the power when the wiping motor 753 reversely drives the case 759 with the return movement of the case 759. It is advisable to wind up the cloth sheet 762. In the case 759, one liquid injection head 1 is wiped by one reciprocating movement, and the wiping of two liquid injection heads 1A and 1B is completed by two reciprocating movements.

The liquid receiving mechanism 751 has a liquid receiving unit 751a for receiving the droplets ejected by the liquid injection head 1 and a flushing motor 754. Flushing refers to maintenance in which the liquid injection head 1 injects liquid as waste liquid for the purpose of preventing and eliminating clogging of the nozzle 21. The liquid receiving portion 751a of the present embodiment is a belt, and the belt is moved by the power of the flushing motor 754 at a time when the amount of ink stain due to flushing of the belt can be considered to exceed the specified amount.

The liquid receiving mechanism 751 includes a driving roller 766, a driven roller 767, and an annular belt 768 wound around both rollers 766 and 767. The outer peripheral surface of the belt 768 is a liquid receiving surface 769 that receives the liquid. The rollers 766 and 767 are arranged apart from each other in the Y-axis direction with the X-axis direction being the axial direction. The belt 768 has a width dimension (length in the X-axis direction) capable of receiving the waste liquid simultaneously ejected by all the nozzles 21 of one liquid injection head 1.

The liquid receiving mechanism 751 scrapes off a moisturizing liquid supply unit (not shown) capable of supplying a moisturizing liquid to the liquid receiving surface 769 and waste liquid or the like adhering to the liquid receiving surface 769 in a moisturized state below the belt 768. It is provided with a liquid scraping unit (not shown). When the belt 768 is moved by the rotation of the drive roller 766, the waste liquid received by the liquid receiving surface 769 is scraped from the belt 768 by the liquid scraping portion. As a result, the liquid receiving surface 769 that next receives the droplet is updated to the portion without the waste liquid.

The cap mechanism 752 includes two cap portions 752a and a capping motor 755. The two cap portions 752a are powered by the capping motor 755 and move between the capping position and the separated position. The capping position is the position where the cap portion 752a is in contact with the liquid injection heads 1A and 1B, and the separation position is the position where the cap portion 752a is separated from the liquid injection heads 1A and 1B. When the liquid injection heads 1A and 1B are stopped at the home position HP as shown by the alternate long and short dash line in FIG. 12, when the cap portion 752a moves from the separated position to the capping position, the cap portion 752a surrounds the opening of the nozzle 21. In contact with the liquid injection heads 1A and 1B. The maintenance in which the cap portion 752a surrounds the opening of the nozzle 21 is referred to as capping, and the state in which the cap portion 752a is in contact with the liquid injection heads 1A and 1B is referred to as a capping state.

One cap portion 752a includes four suction caps 770. The suction cap 770 contacts the liquid injection head 1 and forms a space surrounding the nozzle group (two rows of nozzle rows NL shown in FIG. 3). The suction cap 770 is connected to the suction pump 773 via a tube 772. When the suction pump 773 is driven during capping, a negative pressure is generated in the suction cap 770, and the inside of the liquid injection head 1 is sucked. By this suction, the thickened liquid and air bubbles in the liquid injection head 1 are discharged. Such maintenance for discharging the liquid from the nozzle 21 by suction is called suction cleaning.

When the suction cleaning is performed, the liquid discharged from the nozzle 21 adheres to the liquid injection head 1. Therefore, after suction cleaning, it is preferable to remove the adhered droplets and the like by wiping. Further, with wiping, foreign matter and air bubbles adhering to the liquid injection head 1 may be pushed into the nozzle 21 or the meniscus (gas-liquid interface in the nozzle 21) may be destroyed, resulting in injection failure. be. Therefore, it is advisable to perform flushing after wiping to discharge the mixed foreign matter and to prepare the meniscus.

As shown in FIG. 13, the cap device 800 includes cap units 801 and 802 for moisturizing, a connection flow path 808, and a supply mechanism 804 capable of supplying moisturizing liquid to the cap units 801 and 802 through the connection flow path 808. To prepare for. In FIG. 13, one connection flow path 808 is shown for each of the cap units 801, 802, but in reality, four connection channels are provided so as to correspond to the number of caps 803, for a total of eight connections. The flow path 808 extends from the moisturizer reservoir 805.

When the liquid injection heads 1A and 1B stop in the maintenance area LA, the cap units 801 and 802 come into contact with the liquid injection heads 1A and 1B so as to surround the opening of the nozzle 21. The maintenance in which the cap units 801 and 802 form a space surrounding the opening of the nozzle 21 in this way is called moisturizing capping. Moisturizing capping is a type of capping. Moisturizing capping suppresses the drying of the nozzle 21. The cap units 801, 802 include four moisturizing caps 803 each. The four caps 803 are arranged in the X-axis direction corresponding to the four nozzle groups of the liquid injection head 1.

As shown in FIG. 14, the supply mechanism 804 includes a moisturizer storage unit 805 capable of storing a moisturizer, a moisturizer storage unit 806 capable of storing a moisturizer to be supplied to the moisturizer storage unit 805, and a moisturizer storage unit. A supply flow path 807 that connects the 805 and the moisturizer accommodating portion 806 is provided. When the moisturizer storage unit 806 is arranged above the moisturizer storage unit 805, the moisturizer can flow down from the moisturizer storage unit 806 toward the moisturizer storage unit 805 through the supply flow path 807.

The cap device 800 includes a holding body 809 for holding the cap units 801, 802 and the moisturizing liquid storage unit 805, and a moisturizing motor 811 (see FIG. 13) for moving the holding body 809 up and down. The cap 803 and the moisturizer storage unit 805 move up and down together with the holding body 809. By this vertical movement, the cap 803 moves to a capping position in contact with the liquid injection head 1 and a separation position away from the liquid injection head 1. That is, the cap 803 can have a capping state in which the cap 803 forms a space CK in which the nozzle 21 opens in contact with the liquid injection head 1 and a non-capping state in which the cap 803 is separated from the liquid injection head 1.

The supply mechanism 804 supplies the moisturizer to the cap 803. The moisturizer is an example of a humidifying fluid for humidifying the space CK. The supply flow path 807 is a flow path for supplying the moisturizer from the moisturizer accommodating section 806 toward the moisturizer storage section 805. The upstream end of the supply flow path 807 is connected to the moisturizer storage unit 806, and the downstream end is housed in the moisturizer storage unit 805. A hole 813 for passing the supply flow path 807 is provided in the upper part of the moisturizer storage unit 805. A pump 812 may be arranged in the middle of the supply flow path 807 to send out the moisturizing liquid in the moisturizing liquid accommodating unit 806 toward the moisturizing liquid storage unit 805. The pump 812 continues to deliver the moisturizer at a constant pressure while the power of the liquid injection device 700 is turned on.

The supply mechanism 804 can replace the moisturizer storage unit 806 by forming the moisturizer storage unit 805, the moisturizer storage unit 806, and the supply flow path 807 separately. In this case, the moisturizer can be replenished by replacing the moisturizer accommodating portion 806. In the supply mechanism 804, the moisturizer storage unit 805, the moisturizer storage unit 806, and the supply flow path 807 may be integrally formed. In this case, it is advisable to provide a replenishment port for replenishing the moisturizer in the moisturizer accommodating portion 806.

The moisturizer storage unit 805 has an outlet 814 to which the upstream end of the connection flow path 808 is connected, an introduction port 805a for introducing the moisturizer supplied from the moisturizer storage unit 806, and the inside of the moisturizer storage unit 805. It has a float valve 815 that opens and closes the introduction port 805a according to the fluctuation of the liquid level of the moisturizer. In the present embodiment, the introduction port 805a is the downstream end of the supply flow path 807.

The float valve 815 has a buoyant body 816 that floats on the moisturizer, a shaft member 817 to which the buoyant body 816 is fixed to the tip, a shaft 818 that rotatably holds the base end of the shaft member 817, and an upper portion of the buoyant body 816. Has a valve portion 819 attached to the. The buoyant body 816 moves in the moisturizer storage unit 805 in an arc around the axis 818 as the liquid level of the moisturizer changes.

When the liquid level of the moisturizer rises in the moisturizer storage portion 805 and reaches the first position h1 shown by the alternate long and short dash line in FIG. 14, the valve portion 819 is pressed against the introduction port 805a by the buoyancy of the buoyant body 816. As a result, the valve portion 819 closes the supply flow path 807, and the supply of the moisturizing liquid from the moisturizing liquid accommodating portion 806 is stopped.

When the liquid level of the moisturizer drops below the first position h1, the valve portion 819 separates from the introduction port 805a and opens the introduction port 805a. In this way, the supply mechanism 804 supplies the moisturizer from the moisturizer accommodating unit 806 so that the liquid level of the moisturizer stored in the moisturizer storage unit 805 is maintained at the first position h1. The first position h1 is preferably a position lower than the nozzle 21 of the liquid injection head 1.

At the upper part of the moisturizer storage unit 805, a communication unit 820 that communicates the inside of the moisturizer storage unit 805 with the atmosphere is provided. The communication portion 820 has an elongated hole extended to meander, for example. Such a communication unit 820 opens the inside of the moisturizer storage unit 805 to the atmosphere while suppressing the evaporation of the evaporated moisturizer in the moisturizer storage unit 805 to the outside.

The upstream end of the connection flow path 808 is connected to the outlet 814, and the downstream end is connected to the cap 803. The moisturizer stored in the moisturizer storage unit 805 is supplied into the cap 803 via the connection flow path 808 by the head difference.

The cap device 800 preferably includes a capillary member 824 arranged to extend from within the connecting flow path 808 into the cap 803. The capillary member 824 is a thin string-shaped member having a capillary force. In this case, it is preferable that the supply mechanism 804 supplies the moisturizer so that the liquid level of the moisturizer is located in the capillary member 824.

The capillary member 824 is, for example, a sponge-like member having open cells of several μm to several hundred μm. As the material of the capillary member 824, for example, polyolefin such as EVA or polyethylene is preferable. The capillary member 824 supplies a moisturizing liquid that passes through the inside of the capillary member 824 by the capillary force toward the cap 803. When the capillary member 824 is made of a highly liquid-repellent substance, the capillary force generated in the gap between the surface of the capillary member 824 and the inner surface of the connecting flow path 808 is used to pass through the outside of the capillary member 824. It is also possible to supply the moisturizing liquid toward the cap 803. In this case, the air (air bubbles) in the connection flow path 808 is discharged to the cap 803 side via the inside of the capillary member 824. When such a capillary member 824 is arranged in the connection flow path 808, the moisturizing liquid can be easily guided toward the cap 803, so that the moisturizing effect in the space CK is enhanced.

The moisturizer stored in the moisturizer storage unit 805 is supplied toward the cap 803 by the head difference through the connection flow path 808. Therefore, the connection flow path 808 is filled with the moisturizer to the same height as the liquid level of the moisturizer in the moisturizer storage unit 805. That is, the moisturizer flows into the connection flow path 808 up to the first position h1. The first position h1 may be set so that the lower end portion of the capillary member 824 is immersed in the inflowing moisturizer in the connection flow path 808.

The first position h1 may be set to a position lower than the space CK. As a result, the moisturizer that has flowed into the first position h1 in the connection flow path 808 evaporates, and the evaporated moisturizer suppresses the drying of the nozzle 21. When the liquid level of the moisturizing liquid drops due to evaporation, the supply mechanism 804 supplies the moisturizing liquid, so that the moisturizing effect in the space CK is maintained.

The moisturizing liquid used in the cap device 800 is preferably the same as the main solvent of the liquid used in the liquid spraying device 700. For example, when the liquid is a water-based resin ink, since the solvent is water, pure water may be used as the moisturizing liquid. When the solvent of the ink is a solvent, it is preferable to use the same solvent as the ink as the moisturizing liquid. Further, as the moisturizing liquid, a liquid containing a preservative in pure water may be used.

The preservative contained in the moisturizer is preferably the same as the preservative contained in the ink. -Benzisothiazolin-3-one (eg, PROXELGXL) and the like can be mentioned. When PROXEL is used as the preservative from the viewpoint of difficulty in foaming, the content in the moisturizer is preferably 0.05% by mass or less.

<About the moisturizing cap>
As shown in FIG. 14, the moisturizing cap 803 includes a recess 851 that forms a space CK surrounding the opening of the nozzle 21 when in contact with the liquid injection head 1.

The moisturizing cap 803 includes a humidifying chamber 852 to which a humidifying fluid for humidifying the space CK is supplied, and a partition wall 853 for partitioning the recess 851 and the humidifying chamber 852. The partition wall 853 is a part of the wall constituting the recess 851 and the humidifying chamber 852, and has gas permeability (particularly water vapor permeability). The partition wall 853 may be a gas permeable portion having at least a part thereof having gas permeability.

The tip of the capillary member 824 extending from the connection flow path 808 is arranged in the humidifying chamber 852. The moisturizing liquid supplied through the connection flow path 808 permeates the capillary member 824 and evaporates, and the humidifying fluid which is the evaporated vapor fills the humidifying chamber 852. The humidifying fluid thus supplied to the humidifying chamber 852 passes through the partition wall 853 and moves into the recess 851 to humidify the space CK. As a result, drying of the nozzle 21 is suppressed during moisturizing capping.

It is preferable that the partition wall 853 has higher gas permeability than the other walls constituting the humidifying chamber 852. For example, when the partition wall 853 constitutes the ceiling of the humidifying chamber 852, the wall constituting the side wall or the bottom wall of the humidifying chamber 852 is made of a material having a lower gas permeability than the partition wall 853 (for example, polypropylene resin, polybutylene terephthalate resin, or the like. It is preferable to use a modified polyphenylene ether resin or the like) or to thicken the wall. Then, it becomes difficult for the humidifying fluid in the humidifying chamber 852 to escape to the outside of the cap 803.

It is preferable that a part of the wall of the recess 851 is composed of a flexible portion 853a that deforms at a pressure smaller than the pressure at which the gas-liquid interface (meniscus) formed in the nozzle 21 breaks. In this embodiment, the partition wall 853 functions as the flexible portion 853a. A part of the partition wall 853 may be a flexible portion 853a that is more easily deflected and displaced than the other portions. For example, the central portion of the partition wall 853 may be a corrugated flexible portion 853a having a cross-sectional waveform that is more easily deflected and displaced than the outer edge portion thereof.

When the partition wall 853 (flexible portion 853a) is deflected and displaced, pressure fluctuation is unlikely to occur in the space CK even when the temperature fluctuates. In particular, when the flexible portion 853a is deformed at a pressure smaller than the pressure at which the meniscus breaks, the breakage of the meniscus due to the pressure fluctuation is suppressed.

The humidifying chamber 852 preferably has an atmospheric communication portion 823 that communicates with the atmosphere on a wall (for example, a bottom wall) different from the partition wall 853. The air communication portion 823 has, for example, an air communication pipe 823a extending downward from the bottom of the cap 803, and an air communication hole 823b formed in the air communication pipe 823a and opened to the humidifying chamber 852. The air communication unit 823 may be provided on the side wall of the humidifying chamber 852.

The humidifying chamber 852 may have an introduction portion 821 for introducing a humidifying fluid below the partition wall 853. The introduction portion 821 has, for example, an introduction pipe 821a extending downward from the bottom of the cap 803, and an introduction hole 821b formed in the introduction pipe 821a and opening to the humidifying chamber 852.

The connection flow path 808 is connected to the introduction unit 821, and the supply mechanism 804 supplies the moisturizing liquid to be the humidifying fluid to the humidification chamber 852 through the connection flow path 808. The supply mechanism 804 preferably supplies the moisturizing liquid so that a space in which the partition wall 853 is flexed and displaced is secured in the humidifying chamber 852. When the humidifying chamber 852 is filled with the moisturizing liquid, the partition wall 853 is less likely to bend and displace. Therefore, it is preferable that the humidifying chamber 852 is not filled with the moisturizing liquid, and gas is present at least in the space in contact with the partition wall 853 constituting the ceiling.

As shown in FIG. 15, the moisturizing cap 803 is engaged with a lip body 856 having a recess 851, a first member 860 for holding the lip body 856, and a second member 870 combined with the first member 860. It comprises a body 880. The locking body 880 has an arm 881 that holds the first member 860 and the second member 870 in a vertically combined state, and a locking claw 882 provided at the tip of the arm 881.

As shown in FIG. 16, the inner bottom surface of the recess 851 (the upper surface of the partition wall 853) may be a flat surface. If the inner bottom surface of the recess 851 is made flat, it is easy to clean the inside of the recess 851 when the inside of the recess 851 becomes dirty due to dripping of droplets or the like.

As shown in FIG. 17, the lip body 856 has an annular contact portion 857 extending upward from the outer edge of the partition wall 853. The contact portion 857 and the partition wall 853 form the wall of the recess 851. The contact portion 857 comes into contact with the nozzle surface 20a (see FIG. 14) when forming the space CK (see FIG. 14). The lip body 856 has a characteristic as a contact portion 857 and is made of an elastomer resin (for example, a styrene-based elastomer resin) having gas permeability as a partition wall 853.

The first member 860 has an engaging recess 861 on which the locking claw 882 is hooked, an annular wall 862 that supports the lip body 856, and an engaging leg portion 863 that engages with the second member 870.
The second member 870 has an annular engaging wall 871 that engages with the engaging leg portion 863, an atmospheric communication portion 823, an introduction portion 821, and an inner wall 872 that projects upward from the inside of the annular engaging wall 871. ..

As shown in FIG. 18, when the tip of the inner wall 872 is arranged below the partition wall 853, the partition wall 853 can be supported by the inner wall 872 when the upper surface of the partition wall 853 is cleaned.
The engaging leg portion 863 may have a recess 863a that opens downward so that the annular engaging wall 871 can be inserted into the recess 863a. The first member 860 and the second member 870 surround and form the humidifying chamber 852. A sealing member 885 made of an annular elastic body may be interposed between the recess 863a and the annular engaging wall 871 so that no gap is formed between the first member 860 and the second member 870.

As shown in FIG. 19, the holding member 886 for holding the capillary member 824 may be housed in the humidifying chamber 852. The holding member 886 has, for example, a plurality of through holes 887 through which the capillary member 824 is passed. In this case, if the capillary member 824 is passed through the through hole 887, the tip of the capillary member 824 can be fixed in the humidifying chamber 852. When the through hole 887 is arranged at a position upward away from the atmospheric communication hole 823b, the capillary member 824 can be separated from the atmospheric communication hole 823b and the outflow of the humidified fluid from the atmospheric communication hole 823b can be suppressed. When arranging the holding member 886, it is preferable to provide a locking protrusion 873 for locking the holding member 886 on the inner wall 872.

Next, the operation of the cap device 800 and the liquid injection device 700 of the present embodiment will be described.
When the space CK is sealed during moisturizing capping, the pressure in the space CK fluctuates when the environmental temperature fluctuates, and the gas-liquid interface in the nozzle 21 may be broken. In that respect, since the cap 803 has a flexible partition wall 853, the partition wall 853 bends and displaces according to the pressure fluctuation, so that the destruction of the gas-liquid interface in the nozzle 21 is suppressed.

According to the cap device 800 and the liquid injection device 700 of the present embodiment, the following effects can be obtained.
(1-1) Since the partition wall 853 allows the humidifying fluid in the humidifying chamber 852 to permeate into the space CK, the nozzle 21 that opens into the space CK can be moistened by the humidifying fluid. When the pressure fluctuates in the space CK where the nozzle 21 opens, the flexible portion 853a constituting the wall of the recess 851 bends and displaces, so that the destruction of the gas-liquid interface formed in the nozzle 21 is suppressed. In this way, the displacement of the flexible portion 853a can reduce the pressure fluctuation of the space CK for moisturizing the nozzle 21.

(1-2) When the gas permeability of the partition wall 853 is made higher than that of the other walls constituting the humidifying chamber 852, the humidifying fluid in the humidifying chamber 852 can be introduced into the recess 851 through the partition wall 853. In addition, it is possible to suppress the permeation of the humidifying fluid from the other walls constituting the humidifying chamber 852 into the external space.

(1-3) Due to the deflection displacement of the partition wall 853, the pressure fluctuation in the space CK for moisturizing the nozzle 21 can be reduced.
(1-4) When the inner bottom surface of the recess 851 is made flat, it is easy to clean the inside of the recess 851.

(1-5) When the air communication unit 823 is provided in the humidification chamber 852, the pressure fluctuation in the humidification chamber 852 can be reduced by the gas flowing through the air communication unit 823. As a result, the deflection displacement of the partition wall 853 due to the pressure fluctuation in the humidifying chamber 852 is suppressed. As a result, the pressure fluctuation in the recess 851 due to the deflection displacement of the partition wall 853 can be suppressed.

(1-6) The pressure fluctuation in the humidifying chamber 852 can be reduced by the bending displacement of the partition wall 853.
(1-7) By infiltrating the moisturizer into the capillary member 824, foaming of the moisturizer can be suppressed.

(1-8) By keeping the liquid level of the moisturizer in the moisturizer storage unit 805 constant by the float valve 815, the liquid level of the moisturizer supplied through the connection flow path 808 can be kept constant.

(Second Embodiment)
As shown in FIG. 20, the liquid injection device 700 of the present embodiment includes eight liquid injection heads 1 held by the carriage 723. The eight liquid injection heads 1 are arranged in the X-axis direction. Of the eight liquid injection heads 1, the liquid injection head 1 located closest to the home position HP (see FIG. 2) injects a treatment liquid (curing agent) for accelerating the curing of the ink, and the remaining seven liquid injection heads 1. The liquid injection head 1 ejects ink. The liquid injection head 1 for injecting the processing liquid is arranged at a position shifted in the Y-axis direction from the other liquid injection heads 1.

Similar to the first embodiment, the liquid injection head 1 has a nozzle surface 20a through which the nozzle 21 opens, and has an injection region PA (see FIG. 2) for injecting liquid to the medium ST (see FIG. 1). , The cap 803 reciprocates between the maintenance area LA and the maintenance area LA in contact with the liquid injection head 1.

The liquid injection head 1 has four nozzle groups arranged in a staggered manner. Two of the four nozzle groups are arranged in the Y-axis direction, and two are arranged in the X-axis direction. The nozzle groups arranged in the X-axis direction are displaced in the Y-axis direction. One nozzle group consists of one or more nozzle rows NL.

The cap device 800 of the present embodiment has a plurality of cap units 810 arranged at positions individually corresponding to the plurality of liquid injection heads 1, a support plate 830 for supporting the plurality of cap units 810, and a lower portion of the support plate 830. It is provided with a support base 831 (see FIG. 24) arranged in the above and a moving mechanism 832 for moving the support plate 830 up and down.

As shown in FIG. 21, the cap unit 810 holds a plurality of caps 803 (four in this embodiment), a cap cover 840, and a plurality of caps 803 and a cap cover 840 individually corresponding to a plurality of nozzle groups. A cap holding portion 833 and an opening / closing mechanism 834 for opening / closing the cap cover 840 are provided.

As shown in FIG. 22, the cap cover 840 has a first cover 840F and a second cover 840S that rotate in opposite directions to each other. It is preferable that the first cover 840F and the second cover 840S have the same shape.

As shown in FIG. 23, the cap holding portion 833 has two rotation shafts 833a protruding in the Y-axis direction. As shown in FIG. 22, the cap cover 840 has an engaging arm 840a that engages with the rotation shaft 833a and a gear 840b that is arranged around the rotation shaft 833a. The rotation shaft 833a extends in a direction along the nozzle surface 20a (see FIG. 20) and intersects the reciprocating movement path (X-axis) of the liquid injection head 1 (see FIG. 20).

As shown in FIG. 22, the gear 840b of the first cover 840F and the gear 840b of the second cover 840S mesh with each other. The first cover 840F and the second cover 840S rotate in opposite directions with respect to the rotation shaft 833a.

As shown in FIG. 24, the first cover 840F has a pinion 840c located on the inner peripheral side of the gear 840b.
The position of the cap 803 when it comes into contact with the liquid injection head 1 to form the space CK (see FIG. 19) is called the capping position (position shown in FIG. 24), and the position where the cap 803 separates from the liquid injection head 1 is the separation position. (Position shown in FIG. 25). The cap 803 moves from the separation position to the capping position as the cap holding portion 833 moves upward, and moves from the capping position to the separation position as the cap holding portion 833 moves downward. The cap holding portion 833 moves up and down as the support plate 830 moves up and down.

The cap cover 840 is placed in the retracted position (positions shown in FIGS. 21 and 25) when the cap 803 is in the capping position, and in the cover position (shown in FIGS. 22 and 24) when the cap 803 is in the separated position. Position). The cap cover 840 covers the recess 851 at the cover position when the cap 803 is at a distance away from the liquid injection head 1. The retracted position is the position where the cap cover 840 retracts from above the cap 803. The cap holding portion 833 movably supports the cap cover 840 between the cover position and the retracted position.

When the cap holding portion 833 moves downward from the position shown in FIG. 24, the cap 803 moves from the capping position to the separated position, and the cap cover 840 moves from the retracted position to the cover position.

When the cap holding portion 833 moves upward from the position shown in FIG. 25, the cap 803 moves from the separated position to the capping position, and the cap cover 840 moves from the cover position to the retracted position.

As shown in FIG. 25, the opening / closing mechanism 834 is engaged with a movable member 835 having a tooth portion 835a that meshes with the pinion 840c, a guide portion 839 that guides the movable member 835, an urging member 836, and an elastic member 837. It has a toothed member 838 and. The guide portion 839 is fixed to the support plate 830. The elastic member 837 is arranged between the support base 831 and the engaging member 838. The engaging member 838 is supported by the support base 831 so as to be movable up and down via the elastic member 837. At the lower end of the movable member 835, an engaging portion 835b arranged at a position overlapping the engaging member 838 in a plan view is provided.

The support plate 830 supports the cap holding portion 833, and the support base 831 supports the cap holding portion 833 via the support plate 830 so as to be vertically movable. While the cap holding portion 833 is moving downward together with the support plate 830, the engaging member 838 engages with the engaging portion 835b of the movable member 835.

In the movable member 835, the tooth portion 835a meshes with the pinion 840c of the first cover 840F, and functions as a rack of a rack and pinion mechanism. When the pinion 840c of the first cover 840F meshes with the upper portion of the tooth portion 835a as shown in FIG. 24, the cap cover 840 is in the retracted position. The cap cover 840 is in the cover position when the pinion 840c of the first cover 840F meshes with the lower portion of the tooth portion 835a as shown in FIG.

The movable member 835 is held so as to be vertically movable with respect to the support plate 830 by restricting the lateral movement by the guide portion 839. The movable member 835 moves downward together with the cap holding portion 833 when the support plate 830 moves downward.

The upper end of the urging member 836 is locked to the support plate 830, and the lower end is locked to the movable member 835. The urging member 836 is, for example, a coil spring, which urges the movable member 835 downward with respect to the support plate 830. In this way, the urging member 836 urges the cap cover 840 toward the retracted position shown in FIG. 24 via the movable member 835.

The upper end of the elastic member 837 is locked to the engaging member 838, and the lower end is locked to the support base 831. The elastic member 837 is, for example, a coil spring, and supports the engaging member 838 on the support base 831. When both the urging member 836 and the elastic member 837 are coil springs, when they are pressed against each other, the urging member 836 contracts before the elastic member 837.

When the cap holding portion 833 and the movable member 835 move downward together with the support plate 830, the engaging portion 835b of the movable member 835 engages with the engaging member 838 during the movement. Then, the movable member 835 moves relative to the cap holding portion 833 by receiving a reaction force from the engaging member 838. That is, the cap holding portion 833 is lowered while the movement of the movable member 835 is restricted.

In this way, the movable member 835 moves relative to the cap holding portion 833 when engaged with the engaging member 838. When the movable member 835 moves upward relative to the support plate 830 from the position shown in FIG. 24, the cap cover 840 rotates together with the pinion 840c, and the cap cover 840 moves from the retracted position to the cover position. In this way, the movable member 835 moves the cap cover 840 when it moves relative to the cap holding portion 833.

The elastic member 837 is elastically deformed when the force received by the engaging member 838 from the movable member 835 becomes larger than the set value. This set value is larger than the urging force of the urging member 836. When the opening / closing mechanism 834 does not include the elastic member 837, the movable member 835 can be brought into contact with the support base 831 to elastically deform the urging member 836. However, if the movement of the movable member 835 is restricted via the elastic member 837, even if there is a manufacturing error in the size or arrangement of the movable member 835 or the engaging member 838, the error is caused by the elastic deformation of the elastic member 837. It can absorb and move the cap cover 840 accurately.

When the cap holding portion 833 and the movable member 835 start to move upward together with the support plate 830 from the position shown in FIG. 25, the movable member 835 moves downward relative to the support plate 830. Then, the cap cover 840 rotates together with the pinion 840c, and the cap cover 840 moves from the cover position to the retracted position.

As shown in FIG. 26, when in the cover position, the cap cover 840 extends downward from the cover portion 841 located above the recess 851 and from the cover portion 841 so as to surround the upper end of the contact portion 857 of the cap 803. It has an enclosure 842 and. As described above, the lower end of the cap cover 840 is preferably located below the upper end of the cap cover 840.

The cap cover 840 at the cover position is arranged above the recess 851 with a gap between the cover portion 841 and the contact portion 857. The cover portion 841 included in the first cover 840F and the second cover 840S is located above the recess 851 and in contact with each other when in the cover position.

In FIG. 26, the lower end of the enclosure 842 is above the upper end of the cap holding portion 833, but the tip of the enclosure 842 is extended downward and the lower end of the enclosure 842 is located below the upper end of the cap holding portion 833. You may. When the cap 803 is covered with the cap cover 840 to a lower position, the cap 803 is prevented from drying even if the cap cover 840 is separated from the cap 803.

In particular, when water vapor lighter than air is used as the humidifying fluid, the water vapor diffused from the humidifying chamber 852 into the cap holding portion 833 moves upward from the gap between the cap holding portion 833 and the cap 803. If the water vapor is retained in the inner space of the cap cover 840 above the lower end of the enclosure 842, the outer space of the cap 803 can also be humidified. Then, the drying of the cap 803 can be effectively suppressed.

As shown in FIG. 27, the lower end of the cap cover 840 is located above the lower end side opening of the air communication portion 823, but the tip of the enclosure 842 is extended downward and the lower end of the enclosure 842 is the lower end of the atmosphere communication portion 823. It may be placed below the lower end. Alternatively, as shown in FIG. 27, the lower end of the atmospheric communication portion 823 may be surrounded by the side wall of the cap holding portion 833. In this way, the humidifying fluid is less likely to flow out from the humidifying chamber 852 through the atmospheric communication portion 823.

In particular, when water vapor lighter than air is used as the humidifying fluid, when the water vapor diffused from the humidifying chamber 852 into the external space stays in the inner space of the cap holding portion 833 above the lower end of the side wall of the cap holding portion 833, it communicates with the atmosphere. The space including the lower end of the portion 823 can also be humidified. Therefore, it becomes difficult for the humidifying fluid to diffuse from the humidifying chamber 852 through the atmospheric communication portion 823.

Next, the operation of the cap device 800 and the liquid injection device 700 of the present embodiment will be described.
When the moisturizing cap 803 is separated from the liquid injection head 1, the recess 851 is open upward. Therefore, foreign matter such as droplets or dust may enter the recess 851 or adhere to the contact portion 857. As described above, when foreign matter adheres to the cap 803, a gap may be formed between the cap 803 and the liquid injection head 1 during capping, and the nozzle 21 may not be properly moisturized.

When the moisturizing is insufficient and the nozzle 21 dries, the nozzle 21 is clogged and injection defects occur, or cleaning is performed to eliminate the injection defects, resulting in an increase in liquid consumption. In that respect, if the cap 803 is covered with the cap cover 840 when the cap 803 is separated from the liquid injection head 1, the adhesion of foreign matter to the cap 803 is suppressed.

According to the cap device 800 and the liquid injection device 700 of the present embodiment, the following effects can be obtained.
(2-1) When the cap 803 is separated from the liquid injection head 1, the cap cover 840 covers the recess 851 of the cap 803, so that foreign matter is less likely to adhere to the cap 803. Therefore, when the cap 803 comes into contact with the liquid injection head 1, the nozzle 21 can be efficiently moisturized.

(2-2) When the cap cover 840 comes into contact with the cap 803, foreign matter attached to the cap 803 may adhere to the cap cover 840. If foreign matter adheres to the cap cover 840, the foreign matter may reattach to the cap 803 and stain the cap 803. According to the above embodiment, since the cap cover 840 covers the cap 803 without contacting the cap 803, foreign matter attached to the cap 803 is unlikely to adhere to the cap cover 840. Therefore, foreign matter attached to the cap cover 840 is unlikely to reattach to the cap 803.

(2-3) The space CK in which the nozzle 21 opens can be humidified by the humidifying fluid supplied from the supply mechanism 804. Thereby, the drying of the nozzle 21 can be suppressed.

(2-4) In the cap cover 840, the covering portion 841 can suppress foreign matter from entering the recess 851, and the surrounding portion 842 can suppress the diffusion of the moisturizing component from the inside of the recess 851.

(2-5) Since the cap holding portion 833 holds the cap 803 and the cap cover 840, the cap cover 840 can be moved together with the cap 803.
(2-6) The cap cover 840 can be stably arranged at the retracted position by the urging force of the urging member 836.

(2-7) When the cap 803 is moved from the capping position to the separated position in conjunction with the downward movement of the cap holding portion 833, the cap cover 840 can be moved from the retracted position to the cover position. As a result, the cap 803 can be immediately covered with the cap cover 840 after the capping is released.

(2-8) The movable member 835 moves the cap cover 840 by receiving the urging force of the elastic member 837 via the engaging member 838. Therefore, even if there is a manufacturing error in the size or arrangement of the movable member 835 or the engaging member 838, the error can be absorbed by the elastic deformation of the elastic member 837, and the cap cover 840 can be moved accurately.

(2-9) Since the cap cover 840 rotates about the rotation shaft 833a that intersects the reciprocating movement path of the liquid injection head 1, it is easy to move to the retracted position even if it comes into contact with the liquid injection head 1. Therefore, damage to the cap cover 840 and the liquid injection head 1 due to contact can be reduced.

(2-10) Since the cap cover 840 has a configuration divided into a first cover 840F and a second cover 840S, the moving distance of the cap cover 840 can be shortened.
(Change example)
The above embodiment may be modified as in the modification shown below. The configuration included in the above embodiment can be arbitrarily combined with the configuration included in the following modification example. The configurations included in the following modification examples can be arbitrarily combined.

The cap device 800 may include the cap 803 of the first modification shown in FIGS. 28 and 29. The cap cover 840 can cover the cap 803 of the first modification. The cap 803 of the first modification example does not have a partition wall 853 and a humidifying chamber 852, and has an inner bottom surface 822 of the cap 803 facing the nozzle 21 during moisturizing capping, an introduction portion 821 opening to the inner bottom surface 822, and an atmospheric communication portion. 823 and. The inner bottom surface 822 and the contact portion 857 form a recess 851. The downstream end of the connection flow path 808 (see FIG. 14) is connected to the introduction section 821. The air communication portion 823 is provided on the inner bottom surface 822 of the cap 803, and opens the space CK formed by the moisturizing capping to the atmosphere.

The capillary member 824 may be bent on the inner bottom surface 822 of the cap 803 to the side opposite to the side where the atmospheric communication portion 823 is provided. In this case, it is preferable that the cap 803 is provided with a plate member 825 that presses the capillary member 824 from above along the inner bottom surface 822. By pressing the capillary member 824 with the plate member 825, the capillary member 824 can be aligned with the inner bottom surface 822 of the cap 803.

The atmospheric communication portion 823 may be composed of a through hole 826 penetrating the inner bottom surface 822 and a pin 827 press-fitted into the through hole 826. A narrow groove 828 extending spirally may be formed on the outer periphery of the pin 827.

As shown in FIG. 29, when a spiral gap (groove 828) is formed between the inner peripheral surface of the through hole 826 and the outer peripheral surface of the pin 827, the space CK (see FIG. 28) is formed through this gap. It can communicate with the atmosphere. The tip of the pin 827 located on the inner bottom surface 822 may be pressed by the plate member 825. Further, the base end of the pin 327 may be fastened with a washer 829. The air communication unit 823 opens the space CK (see FIG. 28) of the cap 803 to the atmosphere while suppressing the moisturizing liquid evaporated in the space CK from coming out during the moisturizing capping.

The partition wall 853 may be provided on the side wall of the recess 851 as in the second modification shown in FIG. In this case, the recess 851 and the humidifying chamber 852 may be arranged side by side.
-As in the second modification shown in FIG. 30, in the cap 803, the partition wall 853 that allows gas to pass through and the flexible portion 853a may be provided in different portions. In this case, the gas permeability of the partition wall 853 may be higher than that of the other portions.

When the partition wall 853 and the flexible portion 853a are provided in different portions, for example, a pressure damper chamber (not shown) connected from the side wall of the recess 851 by a communication pipe (not shown) is provided, and this pressure damper chamber can be provided. The flexible portion 853a may be used. In this case, the gas permeability of the pressure damper chamber may be low, or the flexibility of the partition wall 853 having gas permeability may be low.

The cap device 800 may include an on-off valve capable of blocking communication with the atmosphere of the air communication unit 823 connected to the humidifying chamber 852 when the cap 803 is not capping.
-As in the second modification shown in FIG. 30, a storage unit 854 for storing the moisturizing liquid may be provided below the humidifying chamber 852 of the cap 803.

The supply mechanism 804 may supply the moisturizer so that the liquid level of the moisturizer stored in the storage unit 854 is located below the air communication unit 823 of the humidification chamber 852.
When the partition wall 853 is integrally formed with the contact portion 857, the lip body 856 can be made of, for example, an elastomer resin.

-The partition wall 853 may be formed as a separate body from the contact portion 857. In this case, the partition wall 853 may be made of an elastic body such as silicone rubber and may be a wall (ceiling portion or the like) of the humidifying chamber 852. Silicone rubber has high gas permeability (particularly water vapor permeability) and has liquid repellency, and is therefore suitable as a material for the partition wall 853. In this case, the partition wall 853 may be detachably covered with the rigid member constituting the side wall of the humidifying chamber 852.

-By allowing the plurality of caps 803 to be individually moved in the vertical direction, the liquid level of the moisturizing liquid may be displaced at the first position h1 and the second position h2. According to this configuration, the position of each cap 803 with respect to the moisturizer storage unit 805 can be changed.

-In the second embodiment, the eight liquid injection heads 1 held by the cap device 800 and the carriage 723 may be arranged to be rotated 180 degrees with the Z axis of FIG. 20 as the rotation axis. In this case, of the eight liquid injection heads 1, the liquid injection head 1 located at the position farthest from the home position HP injects a treatment liquid (hardener) for accelerating the curing of the ink, and the remaining seven liquids. The injection head 1 injects ink. The liquid injection head 1 for injecting the processing liquid is arranged at a position shifted upstream in the transport direction from the other liquid injection heads 1.

In the cap device 800, when the position of the liquid level of the moisturizer stored in the moisturizer storage unit 805 is displaced between the first position h1 and the second position h2, the moisturizer from the moisturizer storage unit 806 The configuration may be such that the moisturizing liquid is not supplied to the storage unit 805. It is possible to displace the liquid level of the moisturizer only by changing the positional relationship between the cap 803 and the moisturizer storage portion 805 in the vertical direction.

The moisturizer storage unit 805 may be configured to be movable in the vertical direction with respect to the cap 803.
-Instead of the float valve 815, a solenoid valve that opens and closes the supply flow path 807 may be provided. In this case, the solenoid valve may be opened and closed so that the liquid level of the moisturizer stored in the moisturizer storage unit 805 is at the first position h1.

-The cap device 800 may be provided with a separate control unit. In this case, the drive of the moisturizing motor 811 and the pump 812 of the cap device 800 is controlled by the control unit included in the cap device 800.

-The capillary member 824 may be provided in the connection flow path 808 over the entire length thereof.
The capillary member 824 does not have to be a cylindrical member as long as it can be arranged in the connection flow path 808. For example, it may be a strip-shaped member having a polygonal cross section, or a circular tubular member.

The supply mechanism 804 may supply the moisturizer from the moisturizer accommodating unit 806 to the moisturizer storage unit 805 only by the head difference.
The supply mechanism 804 may be configured to supply the moisturizer from the moisturizer accommodating portion 806 toward the moisturizer storage portion 805 only by the pressure of the pump 812. In this case, since it is not necessary to consider the head difference between the moisturizer storage unit 805 and the moisturizer storage unit 806, the degree of freedom in arranging the moisturizer storage unit 806 is increased. In this modification, the drive of the pump 812 is controlled so that the liquid level of the moisturizer stored in the moisturizer storage unit 805 is at the first position h1.

The introduction port 805a may be configured to open to the inner wall of the moisturizer storage unit 805.
The atmospheric communication portion 823 may be provided on the side wall portion of the cap 803. According to this modification, the moisturizer is less likely to reach the air communication section 823.

A plurality of supply mechanisms 804 may be provided for each cap 803.
An on-off valve capable of opening and closing the connection flow path 808 may be provided at an intermediate position of the connection flow path 808. According to this modification example, by closing the on-off valve when carrying the cap device 800 or the like, it is possible to reduce the possibility that the moisturizer spills through the cap 803 due to an impact or the like.

The cap 803 may be provided so that all the nozzles 21 of the liquid injection head 1 can be capped together.
The cap mechanism 752 may include a cap cover 840 that covers the suction cap 770.

A wiper for wiping the liquid injection head 1 may be separately provided between the cap device 800 and the injection area PA in the maintenance area LA.
The supply mechanism 804 may supply steam as a humidifying fluid into the cap 803.

When the cap 803 is capping, steam as a humidifying fluid may be supplied to the humidifying chamber 852 to pressurize the space CK. In this case, it is preferable to pressurize the gas-liquid interface formed in the nozzle 21 to the extent that the gas-liquid interface is not broken.

The liquid injection device 700 may be changed to a so-called full-line type liquid injection device in which the carriage 723 is not provided and the long liquid injection head 1 corresponding to the entire width of the medium ST is provided.

The liquid ejected by the liquid injection head 1 is not limited to ink, and may be, for example, a liquid material in which particles of a functional material are dispersed or mixed with the liquid. For example, recording is performed by injecting a liquid substance containing materials such as electrode materials and coloring materials (pixel materials) used in the manufacture of liquid crystal displays, EL (electroluminescence) displays and surface emitting displays in the form of dispersion or dissolution. It may be configured.

-The medium ST is not limited to paper, but may be a plastic film, a thin plate, or the like, or may be a cloth used for a printing device or the like. The medium ST may be clothing of any shape such as a T-shirt, or may be a three-dimensional object of any shape such as tableware or stationery.

<Ink ejected by the liquid injection head>
The ink as a liquid ejected by the liquid injection device 700 contains a resin in composition, and substantially does not contain glycerin having a boiling point of 290 ° C. at 1 atm. If the ink contains substantially glycerin, the dryness of the ink is significantly reduced. As a result, in various media, particularly ink non-absorbent or low-absorbent media, not only the shading unevenness of the image is conspicuous, but also the ink fixability cannot be obtained. Further, it is preferable that the ink does not substantially contain alkyl polyols (excluding the above-mentioned glycerin) having a boiling point of 280 ° C. or higher at 1 atm.

As used herein, "substantially free" means that the amount is not contained in an amount that sufficiently exerts the significance of the addition. Quantitatively speaking, it is preferable that glycerin is not contained in an amount of 1.0% by mass or more, more preferably 0.5% by mass or more, and 0, based on the total mass (100% by mass) of the ink. . It is more preferably not contained in an amount of 1% by mass or more, further preferably not contained in an amount of 0.05% by mass or more, and particularly preferably not contained in an amount of 0.01% by mass or more. Most preferably, it does not contain 0.001% by mass or more of glycerin.

Next, the additives (components) contained or may be contained in the ink will be described.
[1. Color material]
The ink may contain a coloring material. The coloring material is selected from pigments and dyes.

[1-1. Pigment]
By using a pigment as a coloring material, the light resistance of the ink can be improved. As the pigment, either an inorganic pigment or an organic pigment can be used. The inorganic pigment is not particularly limited, and examples thereof include carbon black, iron oxide, titanium oxide, and silica oxide.

The organic pigment is not particularly limited, but for example, quinacridone pigment, quinacridone quinone pigment, dioxazine pigment, phthalocyanine pigment, anthrapyrimidine pigment, anthanthrone pigment, indanslon pigment, flavanthron pigment, Examples thereof include perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments. .. Specific examples of the organic pigment include the following.

Pigments used in cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 15:34, 16, 18, 22, 60, 65, 66, C.I. I. Bat blue 4, 60 can be mentioned. Above all, C.I. I. Pigment Blue 15: 3 or 15: 4 is preferred.

Pigments used in magenta ink include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168 , 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, 254, 264, C.I. I. Pigment Violet 19, 23, 32, 33, 36, 38, 43, 50. Above all, C.I. I. Pigment Red 122, C.I. I. Pigment Red 202, and C.I. I. One or more selected from the group consisting of Pigment Violet 19 is preferable.

Pigments used in yellow ink include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 167, 172, 180, 185, 213 and the like. Above all, C.I. I. One or more selected from the group consisting of Pigment Yellow 74, 155, and 213 is preferable.

Examples of pigments used for inks of colors other than the above, such as green ink and orange ink, include conventionally known pigments.
The average particle size of the pigment is preferably 250 nm or less because clogging in the nozzle 21 can be suppressed and the injection stability is further improved. The average particle size in the present specification is based on the volume. As a measuring method, for example, it can be measured by a particle size distribution measuring device based on a laser diffraction / scattering method. Examples of the particle size distribution measuring device include a particle size distribution meter (for example, Microtrac UPA manufactured by Nikkiso Co., Ltd.) whose measurement principle is a dynamic light scattering method.

[1-2. dye]
A dye can be used as the coloring material. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. The content of the coloring material is preferably 0.4 to 12% by mass, more preferably 2% by mass or more and 5% by mass or less, based on the total mass (100% by mass) of the ink.

[2. resin]
The ink contains a resin. When the ink contains a resin, a resin film is formed on the medium, and as a result, the ink is sufficiently fixed on the medium, and the effect of mainly improving the scratch resistance of the image is exhibited. Therefore, the resin emulsion is preferably a thermoplastic resin. The heat distortion temperature of the resin is preferably 40 ° C. or higher, preferably 60 ° C. or higher, because it is less likely to cause clogging of the nozzle 21 and has an advantageous effect of imparting abrasion resistance to the medium. More preferred.

Here, the "heat distortion temperature" in the present specification is a temperature value represented by a glass transition temperature (Tg) or a minimum film forming temperature (MFT). That is, "heat distortion temperature of 40 ° C. or higher" means that either Tg or MFT may be 40 ° C. or higher. Since it is easier to grasp the superiority or inferiority of the redispersibility of the resin in MFT than in Tg, the heat distortion temperature is preferably a temperature value expressed in MFT. If the ink has excellent redispersibility of the resin, the ink does not stick to the ink, so that the nozzle 21 is less likely to be clogged.

Specific examples of the thermoplastic resin include, but are not limited to, poly (meth) acrylic acid esters or copolymers thereof, polyacrylonitrile or copolymers thereof, polycyanoacrylates, polyacrylamides, poly (meth) acrylic acids and the like. (Meta) acrylic polymers, polyethylene, polypropylene, polybutene, polyisobutylene, and polystyrene, and their copolymers, as well as polyolefin polymers such as petroleum resins, kumaron-inden resins, and terpene resins, polyvinyl acetate. Or a polymer thereof, a vinyl acetate-based or vinyl alcohol-based polymer such as polyvinyl alcohol, polyvinyl acetal, and polyvinyl ether, polyvinyl chloride or a copolymer thereof, polyvinylidene chloride, a fluororesin, and a halogen-containing polymer such as fluororubber. Niene-containing vinyl polymers such as system polymers, polyvinylcarbazole, polyvinylpyrrolidone or copolymers thereof, polyvinylpyridine, and polyvinylimidazole, polybutadienes or copolymers thereof, polychloroprenes, and diene-based polymers such as polyisoprene (butyl rubber). Examples include polymers and other ring-opening polymerized resins, condensation polymerized resins, and natural polymer resins.

The content of the resin is preferably 1 to 30% by mass, more preferably 1 to 5% by mass, based on the total mass (100% by mass) of the ink. When the content is within the above range, the glossiness and scratch resistance of the formed topcoat image can be further improved. Examples of the resin that may be contained in the ink include a resin dispersant, a resin emulsion, and wax.

[2-1. Resin emulsion]
The ink may contain a resin emulsion. When the medium is heated, the resin emulsion preferably forms a resin film together with wax (emulsion), thereby sufficiently fixing the ink on the medium and demonstrating the effect of improving the scratch resistance of the image. When the medium is printed with an ink containing a resin emulsion due to the above effects, the ink becomes excellent in scratch resistance particularly on an ink non-absorbent or low-absorbent medium.

Further, the resin emulsion that functions as a binder is contained in the ink in an emulsion state. By containing a resin that functions as a binder in the ink in an emulsion state, it is easy to adjust the viscosity of the ink to an appropriate range in the inkjet recording method, and it is possible to improve the storage stability and the injection stability of the ink.

Resin emulsions include, but are not limited to, (meth) acrylic acid, (meth) acrylic acid ester, acrylonitrile, cyanoacrylate, acrylamide, olefin, styrene, vinyl acetate, vinyl chloride, vinyl alcohol, vinyl ether, and vinylpyrrolidone. , Vinylpyridine, vinylcarbazole, vinylimidazole, and vinylidene chloride homopolymers or copolymers, fluororesins, and natural resins. Among them, either a methacrylic acid resin or a styrene-methacrylic acid copolymer resin is preferable, and either an acrylic resin or a styrene-acrylic acid copolymer resin is more preferable, and a styrene-acrylic acid copolymer resin is more preferable. Even more preferable. The above-mentioned copolymer may be in any form of a random copolymer, a block copolymer, an alternate copolymer, and a graft copolymer.

The average particle size of the resin emulsion is preferably in the range of 5 nm to 400 nm, and more preferably in the range of 20 nm to 300 nm in order to further improve the storage stability and jet stability of the ink. Among the resins, the content of the resin emulsion is preferably in the range of 0.5 to 7% by mass with respect to the total mass (100% by mass) of the ink. When the content is within the above range, the solid content concentration can be lowered, so that the injection stability can be further improved.

[2-2. wax]
The ink may contain wax. When the ink contains wax, the fixing property of the ink on the non-absorbent and low-absorbent medium becomes more excellent. Emulsion type wax is more preferable. Examples of the wax include, but are not limited to, polyethylene wax, paraffin wax, and polyolefin wax, and polyethylene wax, which will be described later, is preferable. In addition, in this specification, a "wax" mainly means a thing in which solid wax particles are dispersed in water by using the surfactant which will be described later.

When the ink contains polyethylene wax, the scratch resistance of the ink can be improved. The average particle size of the polyethylene wax is preferably in the range of 5 nm to 400 nm, and more preferably in the range of 50 nm to 200 nm in order to further improve the storage stability and jet stability of the ink.

The content of the polyethylene wax (in terms of solid content) is preferably in the range of 0.1 to 3% by mass and 0.3 to 3% by mass with respect to the total mass (100% by mass) of the ink independently of each other. It is more preferably in the range of% by mass, and even more preferably in the range of 0.3 to 1.5% by mass. When the content is within the above range, the ink can be satisfactorily solidified or fixed even on a medium having no ink absorption or low absorption, and the storage stability and injection stability of the ink are further excellent. Can be.

[3. Surfactant]
The ink may contain a surfactant. Examples of the surfactant include, but are not limited to, nonionic surfactants. The nonionic surfactant has the effect of spreading the ink uniformly on the medium. Therefore, when printing is performed using an ink containing a nonionic surfactant, a high-definition image with almost no bleeding can be obtained. Such nonionic surfactants are not limited to the following, but are, for example, silicon-based, polyoxyethylene alkyl ether-based, polyoxypropylene alkyl ether-based, polycyclic phenyl ether-based, sorbitan derivatives, and fluorine-based interfaces. Examples thereof include activators, and among them, silicon-based surfactants are preferable.

The content of the surfactant is 0.1% by mass or more and 3% by mass or less with respect to the total mass (100% by mass) of the ink because the storage stability and the injection stability of the ink are further improved. It is preferably in the range.

[4. Organic solvent]
The ink may contain a known volatile water-soluble organic solvent. However, as described above, the ink does not substantially contain glycerin (boiling point at 1 atm is 290 ° C), which is a kind of organic solvent, and alkyl polyols having a boiling point of 280 ° C or higher at 1 atm. It is preferable that (excluding the above-mentioned glycerin) is substantially not contained.

[5. Aprotic polar solvent]
The ink may contain an aprotic polar solvent. By containing the aprotic polar solvent in the ink, the above-mentioned resin particles contained in the ink are dissolved, so that clogging of the nozzle 21 can be effectively suppressed during printing. In addition, since it has the property of dissolving a medium such as vinyl chloride, the adhesion of the image is improved.

The aprotic polar solvent is not particularly limited, but is one or more selected from pyrrolidones, lactones, sulfoxides, imidazolidinones, sulfolanes, urea derivatives, dialkylamides, cyclic ethers, and amide ethers. It is preferable to include. Representative examples of pyrrolidones include 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone, and typical examples of lactones include γ-butyrolactone, γ-valerolactone, and ε-caprolactone. Typical examples of sulfoxides are dimethyl sulfoxide and tetramethylene sulfoxide.

Representative examples of imidazolidinones include 1,3-dimethyl-2-imidazolidinone, representative examples of sulfolanes include sulfolanes and dimethylsulfolanes, and representative examples of urea derivatives include dimethylurea and dimethylurea. There are 1,1,3,3-tetramethylurea. Representative examples of dialkylamides include dimethylformamide and dimethylacetamide, and typical examples of cyclic ethers include 1,4-dioxane and tetrahydrofuran.

Among them, pyrrolidones, lactones, sulfoxides and amide ethers are particularly preferable, and 2-pyrrolidone is most preferable from the viewpoint of the above-mentioned effects. The content of the aprotic and aprotic polar solvent is preferably in the range of 3 to 30% by mass, more preferably in the range of 8 to 20% by mass, based on the total mass (100% by mass) of the ink. preferable.

[6. Other ingredients]
Ink may further contain a fungicide, a rust inhibitor, a chelating agent and the like in addition to the above components.

Next, the components of the surfactant mixed with the moisturizer will be described.
Surfactants include cationic surfactants such as alkylamine salts and quaternary ammonium salts; anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, and fatty acid salts; alkyldimethylamine oxides. , Alkylcarboxybetaine and other amphoteric surfactants; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, and polyoxyethylene / polyoxypropylene block copolymers. Etc. can be used, but among these, anionic surfactants or nonionic surfactants are particularly preferable.

The content of the surfactant is preferably 0.1 to 5.0% by mass with respect to the total mass of the moisturizer. Further, from the viewpoint of foaming property and defoaming property after foaming, the content of the surfactant is preferably 0.5 to 1.5% by mass with respect to the total mass of the moisturizing liquid. The surfactant may be only one kind or two or more kinds. Further, the surfactant contained in the moisturizing liquid is preferably the same as the surfactant contained in the ink (liquid). For example, the surfactant contained in the ink (liquid) has a nonionic surfactant. In the case of the agent, the nonionic surfactant is not limited to the following, and for example, silicon-based, polyoxyethylene alkyl ether-based, polyoxypropylene alkyl ether-based, polycyclic phenyl ether-based, sorbitan derivative, and fluorine-based. Surfactants can be mentioned, with silicon-based surfactants being preferred.

In particular, the foam height immediately after foaming and 5 minutes after foaming using the Rosmiles method is within the above range (the foam height immediately after foaming is 50 mm or more, and the foam height after 5 minutes of foaming is 5 mm or less). In order to achieve this, an adduct in which ethylene oxide (EO) is added to acetylene diol with an addition number of 4 to 30 is used as a surfactant, and the content of the adduct is 0 with respect to the total weight of the washing liquid. It is preferably 1 to 3.0% by weight. Further, the foam height immediately after foaming and 5 minutes after foaming using the Rosmiles method is within the above preferable range (the foam height immediately after foaming is 100 mm or more, and the foam height after 5 minutes of foaming is 5 mm or less). In order to obtain the above value, an adduct in which ethylene oxide (EO) is added to acetylene diol with an addition number of 10 to 20 is used, and the content of the adduct is 0.5 to 1 with respect to the total weight of the washing liquid. It is preferably 5.5% by weight. However, if the content of the ethylene oxide adduct of acetylene diol is too large, the critical micelle concentration may be reached and an emulsion may be formed.

The surfactant has a function of making it easy for the water-based ink to wet and spread on the recording medium. The surfactants that can be used in the present invention are not particularly limited, and are anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, and fatty acid salts; polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyls. Nonionic surfactants such as ethers, acetylene glycols, and polyoxyethylene / polyoxypropylene block copolymers; cationic surfactants such as alkylamine salts and quaternary ammonium salts; silicone-based surfactants; A fluorosurfactant or the like can be used.

The surfactant has the effect of subdividing and dispersing the agglomerates due to the surface-active effect between the moisturizer and the agglomerates. Further, since it has a function of lowering the surface tension of the cleaning liquid, the cleaning liquid easily penetrates between the agglomerate and the nozzle surface 20a, and has an effect of facilitating the separation of the agglomerate from the nozzle surface 20a.

As the surfactant, any compound having a hydrophilic portion and a hydrophobic portion in the same molecule can be preferably used. As a specific example, those represented by the following formulas (I) to (IV) are preferable. That is, the polyoxyethylene alkyl phenyl ether-based surfactant of the following formula (I), the acetylene glycol-based surfactant of the formula (II), the polyoxyethylene alkyl ether-based surfactant of the following formula (III), and the formula (IV). ) Polyoxyethylene polyoxypropylene alkyl ether-based surfactant.

（Ｒは分岐していてもよい炭素数６～１４の炭化水素鎖、ｋ：５～２０）

(R is a hydrocarbon chain having 6 to 14 carbon atoms which may be branched, k: 5 to 20)

（ｍ、ｎ≦２０，０＜ｍ＋ｎ≦４０）

(M, n ≦ 20,0 <m + n ≦ 40)

（Ｒは分岐してもよい炭素数６～１４の炭化水素鎖、ｎは５～２０）

(R is a hydrocarbon chain having 6 to 14 carbon atoms that may be branched, n is 5 to 20)

（Ｒは炭素数６～１４の炭化水素鎖、ｍ、ｎは２０以下の数）
前記式（Ｉ）～（IV）の化合物以外では、例えばジエチレングリコールモノフェニルエーテル、エチレングリコールモノフェニルエーテル、エチレングリコールモノアリルエーテル、ジエチレングリコールモノフェニルエーテル、ジエチレングリコールモノブチルエーテル、プロピレングリコールモノブチルエーテル、テトラエチレングリコールクロロフェニルエーテル等の多価アルコールのアルキル及びアリールエーテル類、ポリオキシエチレンポリオキシプロピレンブロック共重合体等のノニオン系界面活性剤、フッ素系界面活性剤、エタノール、２－プロパノール等の低級アルコール類を用いることができるが、特にジエチレングリコールモノブチルエーテルが好ましい。

(R is a hydrocarbon chain having 6 to 14 carbon atoms, and m and n are numbers of 20 or less)
Other than the compounds of the formulas (I) to (IV), for example, diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, tetraethylene glycol chlorophenyl. Use alkyl and aryl ethers of polyhydric alcohols such as ethers, nonionic surfactants such as polyoxyethylene polyoxypropylene block copolymers, fluorine-based surfactants, and lower alcohols such as ethanol and 2-propanol. However, diethylene glycol monobutyl ether is particularly preferable.

CK ... space, h1 ... first position, LA ... maintenance area, MA ... suction area, PA ... injection area, RA ... maintenance area, ST ... medium, 1,1A, 1B ... liquid injection head, 2 ... head unit, 11 ... Head body, 12 ... Pressure chamber, 20 ... Nozzle plate, 20a ... Nozzle surface, 21 ... Nozzle, 22 ... Control unit, 700 ... Liquid injection device, 701 ... Housing, 702 ... Liquid supply source, 710 ... Maintenance unit , 720 ... printing unit, 723 ... carriage, 750 ... wiping mechanism, 750a ... wiping member, 751 ... liquid receiving mechanism, 751a ... liquid receiving part, 752 ... cap mechanism, 752a ... cap part, 800 ... cap device, 801 ... cap Unit, 802 ... cap unit, 803 ... cap, 804 ... supply mechanism, 805 ... moisturizing liquid storage unit, 805a ... introduction port, 806 ... moisturizing liquid accommodating unit, 807 ... supply flow path, 808 ... connection flow path, 809 ... holding Body, 810 ... cap unit, 811 ... moisturizing motor, 812 ... pump, 813 ... hole, 814 ... outlet, 815 ... float valve, 816 ... buoyant body, 817 ... shaft material, 818 ... shaft, 819 ... valve part, 820 ... communication part, 821 ... introduction part, 821a ... introduction pipe, 821b ... introduction hole, 822 ... inner bottom surface, 823 ... atmosphere communication part, 823a ... atmosphere communication pipe, 823b ... atmosphere communication hole, 824 ... capillary member, 825 ... Plate member, 826 ... Through hole, 827 ... Pin, 828 ... Groove, 829 ... Washer, 830 ... Support plate, 831 ... Support stand, 832 ... Movement mechanism, 833 ... Cap holding part, 833a ... Rotating shaft, 834 ... Opening and closing Mechanism, 835 ... movable member, 835a ... tooth part, 835b ... engaging part, 836 ... urging member, 837 ... elastic member, 838 ... engaging member, 839 ... guide part, 840 ... cap cover, 840a ... engaging arm , 840b ... Gear, 840c ... Pinion, 840F ... First cover, 840S ... Second cover, 841 ... Cover, 842 ... Enclosure, 851 ... Recess, 852 ... Humidity chamber, 853 ... Bulk partition, 853a ... Flexible part, 854 ... Reservoir, 856 ... Lip body, 857 ... Contact part, 860 ... First member, 861 ... Engagement recess, 862 ... Circular wall, 863 ... Engagement leg, 863a ... Recess, 870 ... Second member, 871 ... Circular engagement wall, 872 ... Inner wall, 873 ... Locking protrusion, 880 ... Locking body, 881 ... Arm, 882 ... Locking claw, 885 ... Seal member, 886 ... Holding member, 887 ... Hole.

Claims (7)

A cap device capable of forming a space surrounding the opening of the nozzle when in contact with a liquid injection head having a nozzle for injecting a liquid.
The recesses that form the space and
A humidifying chamber to which a humidifying fluid for humidifying the space is supplied, and
A partition wall having gas permeability that separates the recess and the humidifying chamber,
Equipped with
The partition wall is composed of a flexible portion that deforms at a pressure smaller than the pressure at which the gas-liquid interface formed in the nozzle breaks.
Gas is housed in the humidifying chamber at a position in contact with the partition wall.
A cap device characterized by that. The cap device according to claim 1, wherein the partition wall has higher gas permeability than other walls constituting the humidifying chamber. The cap device according to claim 1 or 2, wherein the humidifying chamber has an atmospheric communication portion that communicates with the atmosphere on a wall different from the partition wall. The humidifying chamber has an introduction portion for introducing the humidifying fluid.
The connection flow path connected to the introduction section and
A supply mechanism capable of supplying a moisturizing liquid as a humidifying fluid through the connecting flow path,
Equipped with
The one according to any one of claims 1 to 3, wherein the supply mechanism supplies the moisturizing liquid so that a space in which the partition wall bends and displaces is secured in the humidifying chamber. Cap device. A capillary member having a capillary force arranged so as to extend from the connection flow path into the humidifying chamber is provided.
The cap device according to claim 4, wherein the supply mechanism supplies the moisturizer so that the liquid level of the moisturizer is located in the capillary member. The supply mechanism has a moisturizer storage unit capable of storing the moisturizer and a moisturizer storage unit capable of accommodating the moisturizer supplied to the moisturizer storage unit.
The moisturizer storage unit includes an outlet to which the connection flow path is connected, an introduction port for introducing the moisturizer supplied from the moisturizer storage unit, and the moisturizer in the moisturizer storage unit. The cap device according to claim 4 or 5, further comprising a float valve that opens and closes the introduction port as the liquid level fluctuates. A liquid injection head with a nozzle that injects liquid,
A cap device capable of forming a space surrounding the nozzle opening when in contact with the liquid injection head.
Equipped with
The cap device is
The recesses that form the space and
A humidifying chamber to which a humidifying fluid for humidifying the space is supplied, and
A partition wall having gas permeability that separates the recess and the humidifying chamber,
Have,
The partition wall is composed of a flexible portion that deforms at a pressure smaller than the pressure at which the gas-liquid interface formed in the nozzle breaks.
Gas is housed in the humidifying chamber at a position in contact with the partition wall.
A liquid injection device characterized by that.

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