JPH10119310A - Ink jet recorder and method for maintaining the recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and surely discharge ink to the outside by opening an atmospheric release valve which communicates with the atmosphere in a sub-tank so as to make a state that an ink channel is not closed, and sucking the ink in the sub-tank. SOLUTION: When a cap member 205 is brought into close contact with a nozzle opening of a recording head, a solenoid valve 227 is opened, and a pressurizing pump 229 is driven to pressurize in a maintenance storage container, maintenance liquid is charged in a sub-tank 209 via ink channels 224, 219, 212. After the sub-tank 209 is bulged and a sensor detects full ink, the pump 229 is stopped, and the valve 227 is controlled to close a channel shutting-off mechanism. These operations are repeated many times so that the sub-tank 209, head and channel 212 are sufficiently replaced from ink with the maintenance liquid, the member 205 is brought into close contact with the nozzle opening of the head, thereby finishing the maintenance operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an ink jet recording head and a subtank mounted on a carriage,
The present invention relates to an ink jet recording apparatus in which an ink storage unit is mounted on a housing and supplies ink from the ink storage unit to a recording head via an ink supply path, and a maintenance method thereof.

[0002]

2. Description of the Related Art An ink jet recording apparatus is an apparatus which derives ink from an ink storage means, supplies the ink to a recording head, and directly discharges ink from a fine nozzle of the recording head onto a recording medium to perform recording. Therefore, solidification of the ink, evaporation of the ink solvent, and an increase in the viscosity of the ink accompanying the solidification are factors that hinder the flow of the ink. As a result, the ink ejection behavior from the nozzle becomes unstable, and further,
A phenomenon that ink droplets are not discharged occurs. Also, recently, in order to ensure high print quality for all types of paper, attempts have been made to increase the concentration of the colored solids in the ink or to add a resin component. The decrease in reliability becomes more significant.

As one method for solving such a problem, there is a method of circulating ink by connecting a recording head, a subtank, and an ink storage means endlessly. In a configuration in which ink is circulated in such an endless form, the ink path becomes complicated and large, which leads to an increase in the size of the entire apparatus and, consequently, an increase in cost. In order to solve such a problem, the present applicant has proposed an ink jet recording head including two common ink chambers communicating with both sides of a pressure generating chamber, and an ink supply port connected to the outside of each common ink chamber. And a sub-tank mounted on a carriage, and an ink storage means outside the carriage, and an ink supply means for intermittently feeding the ink of the ink storage means to the printhead are provided, and the printhead is used as a relay point. An ink jet recording apparatus has been proposed in which ink is reciprocated between an ink storage means and a sub tank.

[0004]

According to this, thickening of the ink in the recording head and the sub tank can be prevented as much as possible without complicating the structure. The supply is of a pressurized type, and it is difficult to efficiently replace the ink in the sub-tank at the end of the flow path. This does not contain solid components, even if the water component evaporates, it is shipped with a highly fluid maintenance liquid,
This is an issue in realizing the transport mode.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and an object of the present invention is to provide a maintenance method for efficiently replacing ink and maintenance liquid in an ink jet recording apparatus having a configuration in which ink is reciprocated and circulated. .

[0006]

According to a first aspect of the present invention, there is provided a maintenance method for an ink jet recording apparatus, wherein a sub tank and an ink jet recording head are mounted on a carriage;
An ink storage unit that communicates with the recording head by an ink supply path outside the carriage; an ink supply unit that pressure-feeds the ink from the ink storage unit to the recording head; and the recording head outside a print area of the carriage. A maintenance method for an ink jet recording apparatus, comprising: a capping means for sealing a nozzle opening of the ink jet recording apparatus, wherein the recording head has two common ink chambers communicating with both sides of a pressure generating chamber; A plurality of ink supply ports into which ink flows in from outside, and one of the ink supply ports is connected to the sub-tank, and the other ink supply port is connected to the ink storage means. Means for replenishing ink in the sub tank by passing the recording head by means A preparative recording apparatus, wherein comprises the air release valve for opening and closing the sub-tank, in a state in which opening the air release valve, and open the injection of the recording head,
A first step of sucking and discharging ink in the sub tank and the print head via an ink flow path connecting the print head and the ink storage unit by an external suction device, and an operation of the suction device. Stopping, sealing the nozzle portion of the recording head by the capping means, and filling the sub-tank with the maintenance liquid via an ink flow path connecting the recording head and the ink storage means with an external supply device. It is characterized in that the second step and the first and second steps are repeated a plurality of times.

According to a second aspect of the present invention, in the maintenance method for an ink jet recording apparatus, the recording head and the ink storing means are opened by opening an air release valve and opening a nozzle of the recording head by an external suction device. A first step of sucking and discharging ink in the sub-tank and the print head via an ink flow path connecting the ink jet head, and stopping the operation of the suction device. A second step of sealing and filling the sub-tank with the maintenance liquid via an ink flow path connecting the recording head and the ink storage means with an external supply device, and a plurality of first to second steps. After repeating
The method is characterized by comprising a third step of continuing the supply for the set time t2 by the supply device again and setting the pressure in the sub tank to a supersaturated state.

According to a third aspect of the present invention, in the maintenance method for an ink jet recording apparatus, the recording head and the ink storage unit are opened by opening an air release valve and opening a nozzle of the recording head by an external suction device. A first step of sucking and discharging ink in the sub-tank and the print head via an ink flow path connecting the ink jet head, and stopping the operation of the suction device. A second step of sealing and filling the sub-tank with the maintenance liquid via an ink flow path connecting the recording head and the ink storage means with an external supply device, and a plurality of first to second steps. After repeating
The third step of continuing the supply for the set time t2 with the supply device again to make the pressure in the sub tank supersaturated, and opening the nozzle portion of the recording head by the capping means and allowing the maintenance liquid to flow out from the nozzle. It is characterized by comprising a fourth step.

A maintenance method for an ink jet recording apparatus according to claim 4, wherein the air release valve is opened and the nozzle of the recording head is opened, and the recording head and the ink storage means are opened by an external suction device. A first step of sucking and discharging ink in the sub-tank and the print head via an ink flow path connecting the ink jet head, and stopping the operation of the suction device. A second step of sealing and filling the sub-tank with the maintenance liquid via an ink flow path connecting the recording head and the ink storage means with an external supply device, and a plurality of first to second steps. After repeating
A third step of opening the nozzle portion of the recording head by the capping means and discharging for a set time t4.

A maintenance method for an ink jet recording apparatus according to claim 5, wherein the recording head and the ink storage means are opened by opening an air release valve and opening a nozzle of the recording head by an external suction device. A first step of sucking and discharging ink in the sub-tank and the print head via an ink flow path connecting the ink jet head, and stopping the operation of the suction device. A second step of sealing and filling the sub-tank with the maintenance liquid via an ink flow path connecting the recording head and the ink storage means with an external supply device, and a plurality of first to second steps. After repeating
The third step of continuing the supply for the set time t2 with the supply device again, setting the pressure in the sub tank to a supersaturated state, opening the nozzle portion of the recording head by the capping means, and allowing the maintenance liquid to flow out from the nozzle. A step of opening the nozzle portion of the recording head by the capping means and sealing the nozzle portion of the recording head by the capping means during a third step of performing idle discharge.

The maintenance method for an ink jet recording apparatus according to claim 6, wherein the recording head and the ink storage means are opened by opening an air release valve and opening a nozzle of the recording head by an external suction device. A first step of sucking and discharging ink in the sub-tank and the print head via an ink flow path connecting the ink jet head, and stopping the operation of the suction device. A second step of sealing and filling the sub-tank with the maintenance liquid via an ink flow path connecting the recording head and the ink storage means with an external supply device, and a plurality of first to second steps. After repeating
A third step of opening the air release valve again and opening the nozzle of the recording head, and suctioning and discharging the maintenance liquid in the sub tank and the recording head by the suction device. .

According to a seventh aspect of the present invention, in the maintenance method for an ink jet recording apparatus, the air release valve of the sub tank is electrically opened and closed by using an electromagnetic valve.

The maintenance method for an ink jet recording apparatus according to the present invention is characterized in that the maintenance liquid does not contain a coloring component and has the same physical properties as the ink.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, by opening an air release valve communicating with the atmosphere to the sub-tank, the ink flow path is not closed. Good and reliable discharge of ink to the outside.

An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 are schematic views of an ink jet recording apparatus according to the present invention.

A carriage 102 slidable on both sides on a guide shaft 101 supported by a frame (not shown).
Is provided, and a recording head 103 is provided on the carriage 102.
And a sub-tank unit 104. An ink cartridge 105 having an atmosphere opening means is mounted on the housing, and communicates with the recording head 103 via an ink flow path. Recording head 103 and sub tank unit 1
04 is arranged at a position higher than the ink cartridge 105. The carriage 102 scans along a surface of a platen 106 disposed opposite to a nozzle surface of the recording head 103 by driving means (not shown), and discharges ink from the recording head 103 to perform recording on the recording medium 107. The carriage scannable range in which recording can be performed on the recording medium 107 is between the position of the carriage B and the position of the carriage C. The position of the carriage A is a standby position when the recording head 103 is not recording. A capping unit 108 and a waste ink collecting unit (not shown) are installed at a position facing the standby position of the recording head 103, and maintenance of the recording head is performed in this area.

FIG. 3 is a schematic diagram of an ink supply system of the ink jet recording apparatus of the present invention.

The ink cartridge 105 includes a case 20.
3 is configured to house an ink pack 202 filled with ink, and is connected to a pump 204 via an air flow path 213. The pump operation is controlled by control means (not shown). Recording head 10 mounted on carriage 102
The recording head 1 includes two common ink chambers communicating with both sides of the pressure generating chamber, and a plurality of ink supply chambers into each of which the ink flows from the outside.
03 is connected to the ink pack 202 in the ink cartridge 105 by the ink flow path 212, and the sub tank 209 mounted on the carriage 102 is connected to the other ink supply port of the recording head 103 by the ink flow path 212. It is connected. Sub tank 209
, Sensor units 210 and 211 for detecting the ink filling state in the sub tank are provided. At the top of the sub tank, an atmosphere release valve 217 communicating with the atmosphere is provided.

Next, the configuration of the cap means will be described. Cap member 2 that is in close contact with the nozzle of recording head 103 and covers the nozzle
A wiper 206, which is a member for wiping ink adhered to the nozzle surface of the recording head 103 and the nozzle surface of the recording head 103, is fixed to a cap holder fixing jig 207, and is further attached to an opening / closing frame shaft provided on the cap holder fixing jig 207. The opening / closing frame 208 is fitted. The cap opening / closing frame 208 is configured to be rotatable about a fulcrum 0 (in the direction of arrow D in the figure) by a drive source or a transmission mechanism (not shown), and opens and closes the cap member 205 with respect to the nozzles of the recording head 103. Things. FIG. 3 is a diagram showing a state where the nozzle surface is capped.

FIG. 4 is a schematic view showing a sub-tank portion of the ink jet recording apparatus of the present invention.

The sub-tank 209 is composed of a frame 301 having a boat-shaped top and bottom, a non-breathable flexible film 302 folded back at a folded portion 303, and upper and lower ends of one half thereof adhered to each other. The upper and lower sides and the peripheral edge of the other half of the opening are attached to the frame body 301.

Further, in order to detect a state in which the sub tank 209 is sufficiently filled with ink, that is, a state of ink full, one end is fixed to the frame 301, the other end is extended to the detecting means, and the central portion is always the film 302. A detection piece 304 is provided on the side of the detection piece 304 so as to be elastically contacted. Further, the folded portion 30
An area 305 through which light is transmitted is provided at a lower portion near 3 in order to detect a state in which the ink in the sub tank 209 is depleted, that is, to detect ink empty. When the flexible film 302 is made of a synthetic resin film coated with aluminum or the like in order to ensure non-breathability, the light transmitting region 305 is not coated on the above-described region, and is made of synthetic resin. Only membrane.

In the figure, reference numeral 306 denotes a protective case,
04, the through hole 30 is located at a position facing the light transmitting area 305.
7 and 308, a sensor 309 for detecting the displacement of the detection piece 304 is provided in the through hole 307, and the light transmitting area 3 is provided in the through hole 308.
A sensor 310 for detecting the amount of light passing through the sensor 05 is provided, and constitutes the ink full sensor unit 210 and the ink empty sensor unit 211 in FIG.

The film 302 expands or returns depending on the amount of ink in the sub-tank 209, and the detection piece 304 is displaced. The amount of displacement is detected by the sensor 309, and the amount of ink in the sub-tank 209 is detected. When a certain amount of displacement is exceeded, it is recognized as an ink full state. Alternatively, the pressure inside the sub tank 209 may be detected using a pressure sensor to detect the amount of ink. In this case, when a certain pressure is exceeded, it is recognized as an ink full state.

In the ink empty state, the light transmitting area 3
05 is detected based on the amount of light passing through. Light transmission area 3
05 is formed in the vicinity of the folded portion 303,
When the sub-tank 209 is in a state close to the ink empty state, the ink is removed by the elastic force of the film 302 in the folded portion 303 and adheres. As a result, ink existing between the films 302 is eliminated, and the amount of transmitted light increases. When a certain transmission amount is exceeded, it is recognized as ink empty.

At the time of printing, the following operation is performed. The ink is
Pressurize the inside of the ink cartridge 105 to set the ink pack 2
By compressing 02, it flows into the sub tank 209 via the recording head 103 via the ink flow path 212. Pressurization is performed by using a diaphragm type air pump.
3 is performed by pressurizing the air layer 214 of the ink cartridge 105 connected to the ink cartridge 105. Continue pressurizing, sub tank 2
When the ink fills 09, the ink full sensor unit 210 outputs a signal, stops the pump 204, opens the air release valve 215, and returns to atmospheric pressure. Atmospheric release valve 2
Reference numeral 15 denotes an electromagnetic valve whose opening and closing control is easy, and which performs an opening and closing operation in accordance with maintenance of the recording head 103. The air release valve 215 is open during the recording of the recording head 103 and during standby, and the ink cartridge 105 is opened.
Are open to the atmosphere through an open air port 216. In this embodiment, the ink cartridge 105 is provided with the air release means, but may be provided with an ink supply means having an air release function.

Thereafter, the ink in the sub-tank flows backward due to the head difference based on the height difference between the sub-tank 209 and the ink cartridge 105. When the amount of ink in the sub-tank decreases, the ink empty sensor unit 211 outputs a signal and the pump 204 Is operated to close the air release valve, and refill the sub tank 209 with ink.

Thereafter, each time the ink in the sub tank 209 flows backward and decreases, the reciprocating circulation between the sub tank 209 and the ink cartridge 105 is repeated.

The ink supply path 212 and the recording head 1
03 and the air present in the sub tank 209 are discharged to the outside by the following maintenance operation. By compressing the ink pack 202 by pressurizing the ink cartridge 105, ink and air flow into the sub tank 209 via the ink flow path 212 and the recording head 103. After the ink full detection, the pressurization is continued, and after the pressure in the sub-tank 209 increases, the air release valve provided in the sub-tank 209 is opened by control means (not shown) 217. The air that has flowed into the sub-tank 209 is located at the upper portion by buoyancy, and is discharged to the atmosphere through the opened air release valve.
Thereafter, the air release valve is closed and pressurization is stopped. This series of operations is used in a recovery operation when a printing failure occurs, an operation for removing air bubbles that have entered the ink flow path when the ink cartridge is replaced, and an initial filling operation that is first performed over the user's hand. Also, in the flow path leading to the atmosphere release valve,
By providing a super-water-repellent micro-diameter film, only gas can be permeated, and it is possible to reliably suppress the outflow of ink from the air release valve.

FIG. 5 is a block diagram showing a maintenance method of the ink jet recording apparatus of the present invention.

After the print inspection is completed in the product inspection, the ink cartridge 105 is removed, and the maintenance liquid exchange cartridge is mounted. Ink channel 212
Is connected to an ink flow path 219 formed in the maintenance liquid exchange cartridge, and further branches into two. One ink flow path 220 is connected to a waste liquid tank 223 via a suction pump 221, and the other ink flow path 224 is connected to a maintenance storage container 225 filled with a maintenance liquid. The two branched ink flow paths 220 and 224 are provided with flow path valves 226 and 227 formed by electromagnetic valves. The maintenance storage container 225 is connected to a pressure pump 229 via an air flow path 228. The suction pump 221, the pressure pump 229, and the flow valves 226 and 227 are controlled by control means (not shown).

FIG. 6 is a flowchart showing a first embodiment of the maintenance method of the ink jet recording apparatus according to the present invention, in which the sub tank 209, the head 103, and the ink flow path 212 are filled with the maintenance liquid. It is.

When a maintenance command is issued (S10)
0), the cap opening / closing frame 209 is driven, the cap member 205 is detached from the recording head 103, and the nozzle is opened (S101). The atmosphere release valve 217 is opened by controlling the solenoid valve (S102). The flow valve 226 is opened by controlling the solenoid valve (S103). The suction pump 221 is driven to start suction, and after suction for the set time t1, the suction pump 221 is stopped (S104 to S104).
6). By controlling the solenoid valve, the flow path valve 226 and the atmosphere release valve 2
17 is closed (S107 to S108). The cap member 205 is brought into close contact with the nozzle opening of the recording head 103, and the flow path valve 227 is opened by controlling the solenoid valve (S10).
9-110). The pressurizing pump 229 is driven to pressurize the inside of the maintenance storage container (S111). Ink channel 22
The maintenance liquid is filled into the sub tank 209 via 4, 219, 212. After the sub tank expands and the sensor detects the ink full state, the pressurizing pump 229 is stopped, and the electromagnetic valve 227 is controlled to close the flow path shutoff mechanism 227 (S112 to 114). Ink full detection
In this flowchart, the detection piece 304 shown in FIG.
Although it is performed by the amount of movement, using a pressure sensor,
The ink full may be detected by detecting the pressure in the sub tank 209. Further, even if the ink full state is not detected by the sensor, a method in which the pump 204 is driven in advance and the time until the liquid amount of the sub tank 209 becomes full may be measured and set as the set time t2.

By repeating S101 to S114 a plurality of times, the sub tank 209, the head 103, the ink flow path 21
No. 2 is sufficiently replaced with the maintenance liquid from the ink. In the present embodiment, the repetition is performed five times or more, which reaches a level at which the reliability of clogging in long-term storage can be ensured.

Next, the cap member 205 is connected to the recording head 1.
A series of maintenance operations is completed by bringing the nozzles into close contact with the nozzle opening 03.

FIG. 7 is a flow chart showing a second embodiment of the maintenance method of the ink jet recording apparatus according to the present invention, in which the maintenance liquid is filled to a supersaturated state in the sub tank.

Steps up to S214 are the same as in the first embodiment.

By repeating S201 to S214 a plurality of times, the sub tank 209, the head 103, the ink flow path 21
No. 2 is sufficiently replaced with the maintenance liquid from the ink. In the present embodiment, the repetition is performed five times or more, which reaches a level at which the reliability of clogging in long-term storage can be ensured. In the present embodiment, by repeating three or more times, the level reaches the level at which the reliability of clogging during long-term storage can be ensured.

Thereafter, the cap member 205 is again brought into close contact with the nozzle opening of the recording head 103, and the solenoid valve is controlled to open the atmosphere release valve 217 and the flow path valve 227 (S2).
16-218). The pressure pump 229 is driven to supply the maintenance liquid under pressure (S219). After the set time t2,
The pressurizing pump 229 is stopped, the flow path valve 227 is closed, and the process ends (S220 to S223). The set time t2 is set so that the maintenance liquid amount in the sub tank 209 exceeds the full state and becomes a supersaturated state. In this embodiment, since the maintenance liquid is in a supersaturated state in terms of pressure, there is no generation and growth of air bubbles in the maintenance liquid, and no interruption by air bubbles in the flow path occurs. Reliability can be improved.

FIG. 8 is a flowchart showing a third embodiment of the maintenance method of the ink jet recording apparatus according to the present invention, in which capping is performed after a process of flowing out of a nozzle after replacement with a maintenance liquid.

Steps up to step S215 of the second embodiment are similar steps.

Thereafter, the cap member 205 is again brought into close contact with the nozzle opening of the recording head 103, and the solenoid valve is controlled to open the atmosphere release valve 217 and the flow path valve 227 (S3).
16-317). The pressure pump 229 is driven to supply the maintenance liquid under pressure (S318). After the set time t3,
The flow valve 227 is closed, and the pressurizing pump 229 is stopped (S319 to 321). The set time t3 is set in the sub tank 2
09 is set so that the maintenance liquid volume in the state 09 exceeds the full state and becomes a supersaturated state.

Thereafter, the cap member 205 is removed from the recording head 103, and the nozzle is opened (S322). At this time, since the pressure in the sub tank is supersaturated, the maintenance liquid flows out of the nozzle (S323). After the set time t5, the cap member 205 is brought into close contact with the nozzle of the recording head 103 (S324). The set time t5 secures a time during which the pressure in the sub-tank decreases and becomes equilibrium with the atmosphere, and the maintenance liquid stops flowing out of the nozzle. Since the maintenance liquid flows out of the nozzle, no ink component remains at the nozzle tip. Thereby, the reliability against clogging of the flow path can be improved over a long period of time.

Further, the set time t5 is set so that the cap is capped while the maintenance liquid is flowing out of the nozzle.
In this case, since the maintenance liquid flows out of the nozzle, no ink component remains at the nozzle tip. Further, since the maintenance liquid is sealed while flowing out from the nozzle, the nozzle is sealed without taking in micro bubbles at the tip of the nozzle.

In the present embodiment, the maintenance liquid in the flow path is supersaturated in terms of pressure, and the nozzle portion is sealed without taking in micro bubbles at the nozzle tip. There is no generation and growth of bubbles, and no interruption of the flow path by the bubbles occurs. As a result, the reliability against clogging of the flow path can be improved for a longer period.

FIG. 9- (1) is a flow chart showing a fourth embodiment of the maintenance method of the ink jet recording apparatus according to the present invention. Is what you do.

The steps up to S215 of the second embodiment are the same.

Thereafter, the cap member 205 is removed from the recording head 103, and the nozzle is opened (S416). The idle discharge is performed toward the cap member 205 for a set time t4 (S417 to 418). The set time t4 is a time during which the ink is discharged in an amount that is balanced by the negative pressure in the sub-tank 209 and the water head value of the ink cartridge in the normal standing state. Thereafter, the idle discharge is stopped, and the cap member 205 is moved to the recording head 1.
The nozzle is brought into close contact with the nozzle No. 03 (S419 to S42).
1).

In this embodiment, since the maintenance liquid is discharged from the nozzle toward the cap member 205, the ink attached to the cap member is washed away. Therefore, the ink component does not re-adhere to the nozzle sufficiently replaced with the maintenance liquid. Further, as shown in FIG. 9- (2), the idle discharge is stopped after the cap member 205 is brought into close contact with the recording head (S428 to 429).
In this case, the nozzle is hermetically closed while discharging in an idle state, so that the nozzle is hermetically sealed without taking in micro bubbles.
As a result, the reliability against clogging of the flow path can be improved over a longer period.

FIG. 10 is a flowchart showing a fifth embodiment of the maintenance method for the ink jet recording apparatus according to the present invention, in which the inside of the flow path is emptied after replacement with the maintenance liquid.

The same steps up to step S215 in the second embodiment are performed.

By repeating S501 to 514 a plurality of times, the sub tank 209, the head 103, the ink flow path 21
2 is sufficiently replaced with the maintenance liquid from the ink (S5).
15). Thereafter, the cap member 205 is removed from the recording head 103 again, and the nozzle is opened (S516). By controlling the solenoid valve, the atmosphere release valve 217, the flow path valve 22
6 is opened (S517 to 518). Suction pump 221
Is driven to start suction, and after suction for the set time t5, the suction pump 221 is stopped (S519 to 521). The solenoid valve is controlled to close the flow path valve 226 and the atmosphere release valve 217 (S522 to 523). The cap member 205 is brought into close contact with the nozzle opening of the recording head 103, and the operation is completed (S
524-525). In this embodiment, by setting the number of repetitions of the step S515 to seven or more, the level reaches the level at which the reliability of clogging in long-term storage can be ensured.

In this embodiment, since the sub tank 209, the head 103, and the ink channel 212 are sufficiently replaced with the maintenance liquid and then emptied, the replacement operation with the ink is efficiently performed after reaching the user's hand. It is possible to do.

The maintenance liquid described in the embodiments is an aqueous solution containing no coloring component and no solid component.
In addition, since the liquid properties of the viscosity and the surface tension are the same as those of the ink, the compatibility with the ink is good, and the replacement by discharging and filling can be performed efficiently. In addition, even when performing idle discharge, the discharge can be performed stably without causing a discharge failure.

[0056]

As described above, according to the ink jet recording apparatus and the maintenance method for the ink jet recording apparatus of the present invention, the ink flow path is closed by opening the air release valve communicating with the air in the sub tank. By sucking the ink in the sub-tank in a state where it is not present, the ink can be efficiently and reliably discharged to the outside. In addition, since the suction is performed while communicating with the atmosphere, the sub tank made of the flexible film is not forcibly damaged by the negative pressure.

Further, the maintenance liquid in the flow path is made to be in a supersaturated state in terms of pressure, and the nozzle is sealed while the maintenance liquid flows out or is discharged from the nozzle, so that the maintenance can be performed without taking in micro bubbles at the nozzle tip. The flow path is not blocked due to the generation and growth of bubbles in the liquid. Thereby, the reliability against clogging of the flow path can be improved over a long period of time.

[Brief description of the drawings]

FIG. 1 is a schematic view of an ink jet recording apparatus used in the present invention.

FIG. 2 is a schematic diagram of an ink supply system of the inkjet recording apparatus.

FIG. 3 is a schematic diagram of an ink supply system of the inkjet recording apparatus of the present invention.

FIG. 4 is a schematic diagram showing a sub-tank section of the ink jet recording apparatus of the present invention.

FIG. 5 is a configuration diagram illustrating a maintenance method of the inkjet recording apparatus of the present invention.

FIG. 6 is a flowchart illustrating a first embodiment of a maintenance method for an inkjet recording apparatus according to the present invention.

FIG. 7 is a flowchart showing a second embodiment of the maintenance method for the inkjet recording apparatus of the present invention.

FIG. 8 is a flowchart illustrating a third embodiment of the maintenance method for the inkjet recording apparatus according to the present invention.

FIG. 9 is a flowchart showing a fourth embodiment of the maintenance method for the inkjet recording apparatus of the present invention.

FIG. 10 is a flowchart showing a fifth embodiment of the maintenance method for the inkjet recording apparatus of the present invention.

[Explanation of symbols]

 102 Carriage 103 Recording head 105 Ink cartridge 204 Pump 205 Cap member 209 Sub tank 217 Air release valve 226, 227 Flow path valve 221 External suction pump 229 External pressurizing pump

Claims (8)

[Claims] 1. An ink storage unit having a sub-tank and an ink jet recording head mounted on a carriage, an ink storage unit communicating with the recording head by an ink supply path outside the carriage, and an ink storage unit for supplying the ink of the ink storage unit to the recording head. A maintenance method for the inkjet recording apparatus, comprising: an ink supply unit for pressure-feeding the recording head; and a capping unit for sealing a nozzle opening of the recording head outside the printing area of the carriage. Two common ink chambers communicating with both sides of the generation chamber, and a plurality of ink supply ports into which ink flows from the outside into each of the common ink chambers, one of which is provided to the sub-tank and the other is provided to the sub-tank The ink supply port is connected to the ink storage means, and the ink supply means An ink jet recording apparatus that replenishes ink in the sub-tank by passing through the recording head, the sub-tank includes an air release valve that opens and closes, opens an air release valve, and closes a nozzle of the recording head. A first step of sucking and discharging ink in the sub-tank and the recording head by an external suction device through an ink flow path connecting the recording head and the ink storage means in an opened state; The operation of the suction device is stopped, the nozzle portion of the recording head is sealed by the capping unit, and maintenance is performed on the sub tank via an ink flow path connecting the recording head and the ink storage unit with an external supply device. Wherein the second step of filling the liquid and the first and second steps are repeated a plurality of times. Nsu way. 2. An air release valve is opened, and a nozzle of the recording head is opened, and an external suction device is used to connect the recording head to the ink storage means via an ink flow path. A first step of sucking and discharging the ink in the sub tank and the print head, stopping the operation of the suction device, sealing the nozzle portion of the print head by the capping means, and using an external supply device to print the print head And a second step of filling the sub-tank with the maintenance liquid via an ink flow path connecting the ink storage means, and after repeating the first to second steps a plurality of times, the setting time is again set in the supply device. 2. The method according to claim 1, further comprising a third step of continuing t2 supply and setting the pressure in the sub-tank to a supersaturated state. 3. An air release valve is opened, and a nozzle of the recording head is opened, and an external suction device is used to connect the recording head to the ink storage unit via an ink flow path. A first step of sucking and discharging the ink in the sub tank and the print head, stopping the operation of the suction device, sealing the nozzle portion of the print head by the capping means, and using an external supply device to print the print head And a second step of filling the sub-tank with the maintenance liquid via an ink flow path connecting the ink storage means, and opening an air release valve and opening a nozzle of the recording head. The first step of sucking and discharging the ink in the sub-tank and the recording head by the suction device and the first and second steps are repeated a plurality of times, and then the setting is again performed by the supply device. A third step of continuing supply for t2 to make the pressure in the sub tank supersaturated, and a fourth step of opening the nozzle portion of the recording head by the capping means and allowing the maintenance liquid to flow out from the nozzle. 3. The maintenance method for an ink jet recording apparatus according to claim 2, wherein: 4. An air release valve is opened, and a nozzle of the recording head is opened, and an external suction device is used to connect the recording head to the ink storage means via an ink flow path. A first step of sucking and discharging the ink in the sub tank and the print head, stopping the operation of the suction device, sealing the nozzle portion of the print head by the capping means, and using an external supply device to print the print head And a second step of filling the sub-tank with the maintenance liquid via an ink flow path connecting the ink storage means and the first to second steps a plurality of times. 2. The maintenance method for an ink jet recording apparatus according to claim 1, comprising a third step of opening the nozzle section and discharging the ink for a set time t4. 5. An air release valve is opened, and a nozzle of the recording head is opened, and an external suction device is used to connect the recording head to the ink storage means via an ink flow path. A first step of sucking and discharging the ink in the sub tank and the print head, stopping the operation of the suction device, sealing the nozzle portion of the print head by the capping means, and using an external supply device to print the print head And a second step of filling the sub-tank with the maintenance liquid via an ink flow path connecting the ink storage means, and after repeating the first to second steps a plurality of times, the setting time is again set in the supply device. The supply of t2 is continued, the pressure in the sub-tank is set in a supersaturated state, and the nozzle portion of the recording head is opened by the capping means, and the maintenance liquid flows out from the nozzle. A third step of opening the nozzle portion of the recording head by the capping means, and sealing the nozzle portion of the recording head by the capping means during the third step of performing idle discharge. 5. The maintenance method for an ink jet recording apparatus according to claim 3, wherein: 6. An air release valve is opened, and a nozzle of the recording head is opened, and an external suction device passes the ink through an ink flow path connecting the recording head and the ink storage means. A first step of sucking and discharging the ink in the sub tank and the print head, stopping the operation of the suction device, sealing the nozzle portion of the print head by the capping means, and using an external supply device to print the print head A second step of filling the sub-tank with the maintenance liquid via the ink flow path connecting the ink storage means, and after repeating the first to second steps a plurality of times, open the air release valve again. And a third step of sucking and discharging the maintenance liquid in the sub tank and the print head by the suction device with the nozzle of the print head opened. The maintenance method for an ink jet recording apparatus according to claim 1, wherein 7. The maintenance method for an ink jet recording apparatus according to claim 1, wherein the air release valve of the sub-tank is electrically opened and closed by using an electromagnetic valve. 8. The maintenance method for an ink jet recording apparatus according to claim 1, wherein the maintenance liquid does not contain a coloring component and has the same physical properties as the ink.