JP2017202678A - Liquid discharge unit and device for discharging liquid and method for controlling liquid discharge unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform cleaning of a cap of a maintenance recovery mechanism.SOLUTION: A liquid discharge unit includes: a liquid discharge head which discharges a liquid from a nozzle; and a cap which recovers the liquid discharge head. The liquid discharge head has: an introduction port which supplies the liquid to the liquid discharge head; and a discharge port which discharges the liquid which is not discharged from the nozzle in the liquid discharge head to the outside of the liquid discharge head. The cap has: a drainage introduction port connected with the discharge port of the liquid discharge head; and a drainage discharge port which is connected with suction means and discharges drainage in the cap.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a liquid discharge unit including a liquid discharge head for discharging liquid, an apparatus for discharging liquid by driving the liquid discharge head, and a method for controlling the liquid discharge unit.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, a plotter, or a multi-function machine having these functions, for example, a liquid ejection recording type image formation using a recording head (liquid ejection head) that ejects ink droplets (liquid droplets) is used. An apparatus (ink jet recording apparatus) is known. In the recording head of an ink jet recording apparatus, due to its structure, the ink viscosity rises due to the evaporation of the solvent from the nozzle, the ink solidifies, the dust adheres, and the air bubbles are mixed, resulting in a defective discharge, resulting in a recording failure. Have the problem of causing Therefore, in the conventional ink jet recording apparatus, a maintenance recovery operation (maintenance operation in normal use) is performed for eliminating and recovering factors that may cause recording failure and maintaining and recovering the ejection performance of the recording head.

  However, even if a maintenance operation in normal use is performed, there is a problem that ink adheres to the cap over time, resulting in poor suction and head (nozzle) protection performance. Therefore, the fixing ink is removed from the cap by supplying a cleaning liquid dedicated to the cap and cleaning the cap (for example, Patent Document 1).

  Such cleaning prevents thickened ink from remaining and accumulating in the cap. However, it is necessary to prepare a cleaning liquid dedicated to the cap, which causes a problem in terms of cost.

  Accordingly, it is an object of the present invention to simply clean the cap of the maintenance / recovery mechanism.

  The subject includes a liquid discharge head that discharges liquid from a nozzle and a cap that recovers the liquid discharge head, and the liquid discharge head supplies the liquid to the liquid discharge head, and the liquid discharge head A discharge port that discharges the liquid that has not been discharged from the nozzle in the head to the outside of the liquid discharge head, and the drain is a suction port that is connected to the discharge port of the liquid discharge head; This is solved by a liquid discharge unit connected to the means and having a drainage discharge port for draining the drainage liquid in the cap.

  According to the present invention, when the cleaning liquid is replaced in the liquid discharge head, the drainage introduction port of the cap constituting the maintenance recovery mechanism is connected to the discharge port of the liquid ejection head, and the drainage discharge port of the cap is maintained. Since it is connected to the suction means constituting the recovery mechanism, the cap can be easily cleaned.

1 is a conceptual front view of a main part of an image forming unit of an ink jet recording apparatus according to an embodiment of the present invention. It is a schematic sectional drawing explaining the structure of the liquid chamber inside of a liquid discharge head. It is a conceptual diagram showing the connection state at the time of the head maintenance by the normal use in the liquid discharge unit which concerns on one Embodiment of this invention. It is a conceptual diagram showing the connection state at the time of ink / cleaning-liquid replacement | exchange in the liquid discharge unit which concerns on one Embodiment of this invention. It is a conceptual diagram showing the connection state at the time of the head maintenance by the normal use in the liquid discharge unit which concerns on another embodiment of this invention. It is a conceptual diagram showing the connection state at the time of ink / cleaning-liquid replacement | exchange in the liquid discharge unit which concerns on another embodiment of this invention. FIG. 6 is a flowchart for explaining the flow of ink / cleaning liquid replacement work. It is a timing chart which shows an example of the work timing in the replacement work of an ink / cleaning liquid.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The overall mechanism of the ink jet recording apparatus provided with the maintenance / recovery mechanism is basically the same as that in the past, and this apparatus configured for color printing supplies paper for loading paper into the apparatus main body. A tray and a paper discharge tray for stocking paper on which images have been recorded (formed) are provided, and an operation / display unit such as operation buttons and a display is provided on the upper surface of the apparatus main body. The operation is sufficiently known without any explanation, and the overall explanation is omitted. In the following, the portions particularly relevant to the present invention will be described.

  In FIG. 1, the main part of an image forming unit of an ink jet recording apparatus provided with a maintenance recovery mechanism according to an embodiment of the present invention is viewed from the front side, and the ink jet recording apparatus reciprocates in the forward direction 21 and the backward direction 22. A carriage 4 for (bidirectional scanning) and a transport stage 1 for transporting a sheet 2 as a recording material are provided. The carriage 4 has a plurality of nozzles for ejecting ink droplets of black (K), cyan (C), magenta (M), and yellow (Y) downward in the drawing in a direction perpendicular to the main scanning direction. Liquid ejection heads 5k, 5c, 5m, and 5y (no color distinction are referred to as “liquid ejection heads 5”) serving as nozzle arrays are scanned to form an image by scanning in a direction orthogonal to the paper 2 transport direction. The liquid discharge head 5 includes a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of ink using an electrothermal transducer such as a heating resistor, and a shape memory alloy that uses a metal phase change caused by a temperature change. An actuator, an electrostatic actuator using an electrostatic force, or the like provided as energy generating means for discharging droplets can be used. A driver IC is mounted on the liquid ejection head 5 and is connected to the control unit of the recording apparatus main body via a harness.

  Further, the carriage 4 is equipped with sub tanks 6k, 6c, 6m, 6y (referred to as sub tanks 6 when colors are not distinguished) for supplying ink (liquid) of each color to the liquid discharge head 5. The main tanks 3k, 3c, 3m, which are attached to the main tank loading unit 10 and can be exchanged at any time via the ink supply tubes 17k, 17c, 17m, 17y of the respective colors (the ink supply tubes 17 are referred to when the colors are not distinguished). The ink of each color is supplemented and supplied from 3y (referred to as main tank 3 when colors are not distinguished). Air pumps 7k, 7c, 7m, and 7y (referred to as air pump 7 when colors are not distinguished) are provided above the sub tank 6 as negative pressure forming means for ensuring discharge stability by keeping the pressure inside the sub tank at a negative pressure. The main tank loading unit 10 is provided with supply pumps 8k, 8c, 8m, and 8y for feeding ink in the main tank (referred to as supply pump 8 when colors are not distinguished). The main tank loading unit 10 is also equipped with a cleaning liquid tank 14 containing a cleaning liquid for cleaning the inside of the liquid discharge head 5. The main tank loading unit 10 is connected to the liquid discharge head 5 via the cleaning liquid supply tube 15, the cleaning liquid pump 16 and the sub tank 6. It is connected.

  If the liquid discharge head 5 is further demonstrated, as shown in FIG. 2, the liquid discharge head 5 is provided with the plurality (two in this example) provided on both sides of the frame portion 51 (corresponding to both ends of the nozzle row). Liquid flow path ports 52a and 52b and a common liquid chamber 53 communicating with these liquid flow path ports. Under the common liquid chamber 53 which is a head liquid chamber, an actuator 54 which is a pressure generating means is provided, and individual liquid chambers 55a, Is generated by the actuator 54 so that the ink in the individual liquid chambers 55a, 55b,... Is ejected from the nozzles 56a, 56b,. Of the two liquid flow path ports, one liquid flow path port 52a is connected to the sub tank 6 and is an introduction port for supplying ink to the liquid discharge head 5, and the other liquid flow path port 52b is a common liquid chamber. This is a maintenance discharge port that is used when air bubbles generated in the ink are discharged or when ink and cleaning liquid are replaced.

  Returning to FIG. 1, a maintenance / recovery mechanism 20 for maintaining and recovering the stable ejection state of the liquid ejection head 5 is disposed in the non-printing area on one side of the carriage 4 in the scanning direction. The maintenance / recovery mechanism 20 is provided with caps 9a, 9b, 9c, 9d (cap 9 when not distinguished) for capping a nozzle surface having a plurality of nozzles (nozzle rows) of each liquid ejection head 5. ing. A plurality of (two in this example) liquid flow path ports 92a and 92b are also provided on the cap 9 that contacts and separates from the nozzle surface of the liquid discharge head 5 by the lifting operation. One liquid flow path port 92a is a drainage discharge port connected to the suction pumps 11a, 11b, 11c, and 11d (referred to as the suction pump 11 when not distinguished), and the other liquid flow path port 92b is the liquid discharge head 5 This is a drainage introduction port connected to the drainage port 52b. A drainage tank 12 is installed at the tip of the suction pump 11. The drainage introduction port 92b of the cap 9 and the discharge port 52b of the liquid discharge head 5 are connected by a tube. However, when the inkjet recording apparatus is large, the movement path of the carriage 4 is long. The tube ends of the port 92b and the discharge port 52b of the liquid discharge head 5 are provided with joints 13a, 13b, 13c, and 13d (referred to as joints 13 when not distinguished), and caps only during the ink / cleaning liquid replacement operation. Nine drainage introduction ports 92b and the discharge port 52b of the liquid discharge head 5 may be connected. Even if it is not a large-sized ink jet recording apparatus, the joint 13 may be provided so that the connection between the drainage introduction port 92b of the cap 9 and the discharge port 52b of the liquid discharge head 5 can be disconnected during normal head maintenance.

  An assembly of components related to liquid ejection in which other functional components and mechanisms are integrated with the liquid ejection head 5 is a liquid ejection unit, and an ink supply mechanism including, for example, a carriage 4, a head tank (sub tank 6), and a supply pump 8. , Including at least one of the maintenance and recovery mechanism 20. An apparatus for ejecting liquid by driving the liquid ejection head 5 is an apparatus for ejecting liquid.

  The liquid discharge head 5 of the ink jet recording apparatus performs capping, ink suction, and cap opening in order to cope with a decrease in ink discharge stability caused by repeated image forming operations and an increase in ink viscosity due to non-use over time. The head maintenance is periodically performed in a sequence of discharging the ink in the cap. In addition, the cleaning liquid is introduced into the ink supply path, and the ink and the cleaning liquid are replaced to clean the inside of the flow path and the periphery of the nozzle. FIG. 3 shows the connection state of the ink supply path and maintenance / recovery mechanism during normal head maintenance, and FIG. 4 shows the connection state during ink / cleaning liquid replacement.

  As shown in FIG. 3, during normal head maintenance, the cap 9 is capped on the liquid discharge head 5 and the middle portion of the tube connecting the discharge port 52b of the liquid discharge head 5 and the drain introduction port 92b of the cap 9 is connected. For example, a cam mechanism composed of a cam 102 and a motor 100 is crushed to substantially disconnect the connection between both ports, and the suction pump 11 is driven to generate a negative pressure inside the cap 9. Ink is sucked from the nozzles to restore the ejection state of the liquid ejection head 5. The ink discharged from the cap 9 is discharged and stored in the drainage tank 12 which is a drainage storage unit. Instead of crushing by a cam mechanism or the like, as described above, a joint is provided at each tube end of the drainage introduction port 92b of the cap 9 and the discharge port 52b of the liquid discharge head 5, so that the ink / cleaning liquid Only during the replacement work, the drainage introduction port 92b of the cap 9 and the discharge port 52b of the liquid discharge head 5 may be connected, and the connection may be disconnected during normal head maintenance. The joint is preferably a non-spill type. The non-spill type joint is provided with a liquid dripping prevention valve called a non-spill valve as a double-sided valve, and can suppress liquid leakage at the time of attachment / detachment to zero as much as possible. With such a configuration, unnecessary movement of the redundant tube can be avoided when the carriage 4 scans left and right during printing or during normal head maintenance. When discharging bubbles generated in the liquid chamber of the liquid discharge head 5, the suction pump 11 is driven after connecting the discharge port 52 b of the liquid discharge head 5 and the drain introduction port 92 b of the cap 9. The pressure in the head liquid chamber is reduced, and bubbles are discharged through the liquid flow path port 52 b, the drainage introduction port 92 b, and the cap 9.

  When cleaning the liquid discharge head 5, the cap 9, and the ink path, as shown in FIG. 4, the discharge port 52b of the liquid discharge head 5 and the drain introduction port 92b of the cap 9 are connected and then the liquid discharge head. 5 is driven to send the cleaning liquid from the cleaning liquid tank 14 to the liquid discharge head 5, and the suction pump 11 is driven to generate a negative pressure inside the cap 9, so that the cleaning liquid is discharged from the liquid discharge head 5. By sucking, the ink remaining in the liquid discharge head 5 and the cap 9 is discharged to the drainage tank 12. As a result, a circuit capable of supplying the cleaning liquid used for cleaning the inside of the head with the cleaning liquid and replacing it with ink into the cap is created, and a cleaning liquid supply mechanism dedicated to the cap can be omitted. When replacing the ink and the cleaning liquid, the liquid discharge head 5 may be capped with the cap 9, but the replacement may be performed with the two being separated from each other, and the ink inside the liquid discharge head is discharged from the head. The liquid is discharged from the port 52a to the drainage tank 12 through the inside of the cap 9. The replacement operation in the separated state will be described later.

  In this example, four suction pumps 11 are provided in accordance with the number of liquid discharge heads of each color, but a configuration may be adopted in which the four heads are sequentially sucked by only one suction pump. In this case, the suction cap is only 9a, and the remaining caps 9b, 9c, and 9d function as protective caps for preventing the nozzles of the liquid discharge head 5 from drying and adhering foreign matter during non-printing.

  Industrial inkjet recording apparatuses have a large print target medium, and therefore the distance that the carriage carrying the liquid discharge head moves is large. For this reason, if the discharge port 52b of the liquid discharge head 5 and the drainage introduction port 92b of the cap 9 are always connected, the connection tube becomes long and a large amount of liquid is required for ink / cleaning liquid replacement. Therefore, as shown in FIG. 5, the joints 13 provided at the tube ends of the drainage introduction port 92b of the cap 9 and the discharge port 52b of the liquid discharge head 5 are connected to each other during printing or a normal head. At the time of maintenance, a predetermined operation is performed in a state where they are separated from each other and in a state where the ends of the joints 13 are sealed.

  When replacing the ink / cleaning liquid in the liquid discharge head or the like to clean the liquid discharge head 5 or the like, the drain carrying port 92b of the cap 9 is connected to the carriage carrying the liquid discharge head and the liquid discharge head 5 is discharged. After moving to the position where it is the shortest distance with respect to the port 52b, the respective joints 13 of the cap 9 and the liquid discharge head 5 are connected as shown in FIG. The discharge port 52b of the head 5 is connected (connection process). The position where the discharge port 52b of the liquid discharge head 5 on the carriage and the discharge introduction port 92b of the cap 9 are the shortest distance is a position where the liquid discharge head carried by the carriage, particularly the nozzle surface thereof can contact the cap. is there. The joint 13 is connected to the discharge port 52b of the liquid discharge head 5 and the drain introduction port 92b of the cap 9 by a flexible tube, and is sealed during printing or normal head maintenance as described above. is there. It is desirable to use a non-spill type one-touch joint in order to improve the workability by minimizing ink leakage and air contamination from the joint 13 during removal.

  After connecting the drain introduction port 92b of the cap 9 and the discharge port 52b of the liquid discharge head 5, the cleaning liquid pump 16 is driven to send the cleaning liquid to the liquid discharge head 5, and the suction pump 11 is driven to drive the liquid discharge head 5 Then, the cleaning liquid is sucked into the cap 9 (cleaning liquid supply step), and the ink remaining in the liquid discharge head 5 and the cap 9 is discharged to the liquid discharge tank 12. Since the drainage introduction port 92b of the cap 9 and the discharge port 52b of the liquid discharge head 5 are connected using the joint 13 only at the time of replacement work, the length of the connecting tube can be minimized and necessary for the replacement work. The amount of liquid used can be minimized.

  The replacement work is assumed to be performed by the user or maintenance personnel.For example, in addition to replacing the ink with the cleaning liquid for the purpose of cleaning the inside of the liquid discharge head, the cleaning liquid is changed from the cleaning liquid to the ink in order to resume printing. In the case of re-replacement, the operation for newly filling the liquid discharge head with ink when the liquid discharge head is replaced with a new one is also included. Further, after completion of the replacement work, it is necessary to keep the pressure inside the liquid discharge head constant during printing by cutting off the joint 13 and sealing the joint end.

  A flow in the replacement work in the flow of FIG. 7 will be described. First, the carriage 4 is moved so that the liquid discharge head 5 and the cap 9 can come into contact with each other (S1). Thereafter, the joints 13 of the discharge port 52b of the liquid discharge head 5 and the drainage introduction port 92b of the cap 9 are connected to each other (S2; connection step). After connecting the joint, the cleaning liquid pump 16 is driven to pressurize the head tank (sub tank 6) (S3), and the suction pump 11 is further driven to suck the cap 9 (S4). By driving both pumps, the inside of the liquid discharge head 5 is replaced with the cleaning liquid and the cap 9 is cleaned (S5; cleaning liquid supply step). Thereafter, the cleaning liquid pump 16 is stopped (S6), and the connected joint 13 is removed (S7). Then, the cap 9 is brought into contact with the liquid discharge head 5 (nozzle surface thereof) (S8), and the suction pump 11 is driven to suck ink from the inside of the liquid discharge head 5, more precisely from the individual liquid chamber (S9). . The replacement work is terminated by stopping the suction pump 11 (S10).

  In the replacement operation related to the flow of FIG. 7, the cleaning liquid pump is driven to pressurize the sub tank while the liquid discharge head 5 and the cap 9 are separated from each other, and the cleaning liquid used when replacing the liquid discharge head is used in the cap. The ink adhering to and staying (thickening) is washed away, and the cap is cleaned with the inside of the cap once stored in the cleaning liquid. This is because it is effective to provide a time for dipping in the cleaning liquid in order to promote re-dispersion of the ink by the cleaning liquid when cleaning the ink fixed to the cap over time. Therefore, only the cleaning liquid pump 16 is driven until the cleaning liquid fills the cap (cleaning liquid supply process), and after the cleaning liquid pump 16 is stopped, only the suction pump 11 is driven to discharge the cleaning liquid in the cap (cleaning liquid). By repeating (discharging process) (replacement process), it is possible to create a state where the cap is filled with the cleaning liquid. The cleaning in such a separated state can reduce the amount of cleaning liquid compared with the case where cleaning is performed with the liquid discharge head 5 capped with the cap 9 (contact state), and dirt in the cap is near the nozzle. Does not cause defects that adhere to the surface. In order to obtain the same effect as the cleaning in the separated state by the cleaning in the contact state, it is necessary to lengthen the suction time, which not only consumes a large amount of cleaning liquid but also in the cap due to the contact state. This is because there is a possibility that the dirt will adhere to the vicinity of the nozzle. As a means for detecting the amount of liquid in the cap, it is also possible to detect the liquid level directly with an optical sensor or the like, but there is a risk that the cleaning liquid may overflow from the cap to the outside of the cap and cause a malfunction. Therefore, as a simpler configuration, the driving time of the pump can be set in accordance with the liquid feeding amount and the cap internal volume of the cleaning liquid pump. FIG. 8 is a timing chart showing driving timings of the cleaning liquid pump and the suction pump.

  In this configuration, the ink in the common liquid chamber of the liquid discharge head is replaced with the cleaning liquid in advance by ink / cleaning liquid replacement. However, in order to finally replace the ink in the individual liquid chamber with the cleaning liquid, the cap and the liquid discharge head are replaced. In the contacted state, the inside of the cap is set to a negative pressure, and the ink is sucked from the nozzle and replaced with the cleaning liquid (S9).

  An ink jet recording apparatus ejects ink droplets from a nozzle of a recording head onto a recording material to form an image (recording, printing, printing, printing is also synonymous, and images having meanings such as characters and figures are used as media. A two-dimensional image that includes not only applying to the medium but also an action of applying an image having no meaning such as a pattern to the medium (simply referred to as droplet ejection or liquid ejection for causing a droplet to land on the medium). 3D image (stereoscopic image) as a target). In addition, a liquid discharge head (droplet discharge head) used as a recording head is a functional component that discharges and ejects liquid from nozzles, and a diaphragm is displaced by a piezoelectric actuator or the like to change the volume in the liquid chamber and thereby apply pressure. There are known piezoelectric heads that discharge and discharge liquid droplets, and thermal heads that provide a heating element that generates heat when energized in the liquid chamber and increase the pressure in the liquid chamber by bubbles generated by the heating element and discharge liquid droplets. Yes.

  Further, in the present application, the material of the “recording material” is not limited to paper, and includes a fabric, leather, metal, plastic, glass, wood, ceramics, etc. The term “recording material” is used as a general term including what is called recording paper or the like. The “liquid” discharged from the liquid discharge head is not particularly limited as long as it has a viscosity and surface tension that can be discharged from the head, but the viscosity is 30 mPa · s under normal temperature and normal pressure, or by heating and cooling. The following is preferable. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, solutions, suspensions, emulsions, etc., which include, for example, inkjet inks, surface treatment liquids, components of electronic elements and light emitting elements, and electronic circuit resist patterns It can be used in applications such as forming liquids and three-dimensional modeling material liquids. “Liquid ejection unit” is a collection of parts related to liquid ejection, in which other functional parts and mechanisms are integrated with the liquid ejection head, for example, at least one of a carriage, a head tank, a liquid supply mechanism, and a maintenance / recovery mechanism It is comprised including. The “device for discharging liquid” is a device for driving the liquid discharge head to discharge the liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can be attached, but also an apparatus for ejecting liquid toward air or liquid, and an image forming apparatus In addition to these, there are a three-dimensional modeling apparatus, a treatment liquid coating apparatus, a jet granulating apparatus, and the like.

5 Liquid discharge head 6 Sub tank (head tank)
7 Air pump 9 Cap 11 Suction pump 12 Drain tank 16 Cleaning liquid pump 52a Liquid flow path port (introduction port)
52b Liquid channel port (discharge port)
92a Liquid flow path port (drainage discharge port)
92b Liquid channel port (drainage introduction port)

JP 2000-62213 A

Claims (7)

A liquid discharge head for discharging liquid from a nozzle;
A cap for recovering the liquid discharge head,
The liquid discharge head is
An introduction port for supplying liquid to the liquid discharge head;
A discharge port for discharging the liquid that has not been discharged from the nozzle in the liquid discharge head to the outside of the liquid discharge head;
Have
The cap is
A drainage introduction port connected to a discharge port of the liquid ejection head;
A drainage discharge port connected to suction means for draining the drainage liquid in the cap;
A liquid discharge unit comprising:   The liquid discharge unit according to claim 1, wherein the drainage introduction port of the cap and the discharge port of the liquid discharge head can be connected to and disconnected from each other.   The liquid discharge unit according to claim 2, further comprising a joint that allows the drainage introduction port of the cap and the discharge port of the liquid discharge head to be connected to and disconnected from each other.   The apparatus which discharges the liquid which has the liquid discharge unit as described in any one of Claims 1-3. A method for controlling a liquid discharge unit having a liquid discharge head for discharging liquid from a nozzle,
The liquid discharge unit is
The liquid discharge head having an introduction port for supplying liquid to the liquid discharge head; and a discharge port for discharging liquid that has not been discharged from the nozzle in the liquid discharge head to the outside of the liquid discharge head;
A cap for recovering the liquid discharge head, comprising: a drainage introduction port connected to the discharge port of the liquid discharge head; and a drainage discharge port connected to suction means for discharging the drainage liquid in the cap. When,
With
A connecting step of connecting the discharge port of the liquid discharge head and the drainage introduction port of the cap;
A cleaning liquid supply step of supplying a cleaning liquid into the liquid discharge head with a cleaning liquid pump connected to the introduction port of the liquid discharge head in a state where the discharge port and the liquid discharge port are connected by the connection step;
With the suction means connected to the drainage discharge port of the cap, the cleaning liquid that has passed through the liquid discharge head in the cleaning liquid supply process is passed through the cap via the drainage introduction port. A cleaning liquid discharging step of discharging from the liquid discharging port;
A replacement step of replacing the liquid in the liquid discharge head with the cleaning liquid by repeating the cleaning liquid supply step and the cleaning liquid discharge step;
A method comprising the steps of:   The connection step is performed after the liquid discharge head is moved to a position where the drainage introduction port of the cap is the shortest distance from the discharge port of the liquid discharge head. 5. The method according to 5.   The position at which the discharge port of the liquid discharge head and the drainage introduction port of the cap are at the shortest distance is a position where the liquid discharge head can contact the cap. The method described.

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