JP2007230006A - Liquid jetting device, method for switching liquid thereof, and method for cleaning liquid jetting head therein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recorder capable of reducing an amount of ink consumed in replacement of the ink in a recording head. <P>SOLUTION: This liquid jetting device is equipped with opening/closing means 21 and 22 for opening and closing a plurality of supplying flow channels for supplying the ink to the recording head 30, and an atmospheric air ventilation means 20 that opens the inside of the recording head 30 to the atmospheric air when the ink is sucked by applying a negative pressure to a nozzle by means of a suction pump 11. When the ink to be supplied to the recording head 30 is switched from a first ink A to a second ink B, the sucking is carried out in a condition that the first opening/closing means 21 is closed and the second opening/closing means 22 is opened, and then the first ink A filled in the recoding head 30 is diluted with the second ink B. The ink in the recording head 30 is sucked to be discharged in a condition that the second opening/closing means 22 is closed and the atmospheric air ventilation means 20 is opened. The second ink B is sucked to be filled into the recording head 30 in a condition that the atmospheric air ventilation means 20 is closed and the second opening/closing means 22 is opened. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus used as an ink jet recording apparatus that forms dots on a recording medium by ejecting ink droplets from nozzles mainly corresponding to print data, a liquid switching method of the liquid ejecting apparatus, and ejection in the liquid ejecting apparatus. The present invention relates to a head cleaning method.

  As a liquid ejecting apparatus that ejects liquid onto a target, an ink jet recording apparatus that performs printing by ejecting ink onto a recording sheet is known.

  Such an ink jet recording apparatus has a relatively low noise during printing and can form small dots with a high density. Therefore, these ink jet recording apparatuses are used in many printing including color printing in recent years. Such an ink jet recording apparatus includes an ink jet print head that receives supply of ink from an ink cartridge, and a paper feed mechanism that moves a storage medium perpendicular to the scanning direction of the print head, and records the print head on the carriage. Recording is performed by ejecting ink droplets onto the recording medium by generating mechanical pressure and thermal energy to the print head while moving in the width direction (main scanning direction) of the medium. On the carriage, for example, a print head capable of ejecting black ink and each color ink of yellow, cyan, and magenta is installed, and not only text printing with black ink but also full ink printing by changing the ejection ratio of each ink Is possible.

  In addition, in recent years, in order to improve the quality of color printing, a recording device that uses light cyan and light magenta and uses a total of six colors including black ink has also been provided. There is also a need for an ink jet recording apparatus that makes it possible to replace the ink cartridge without replacing the ink cartridge. Along with this, the capacity of the ink cartridge for supplying ink to each print head is inevitably increased. For example, each ink cartridge is not placed on the carriage but in the cartridge holders arranged on the fixing portions on both sides of the apparatus main body. There is also provided a recording apparatus having a configuration in which the ink is removably loaded and ink is supplied from the cartridge holder to the print head via an ink supply path via a flexible tube or the like.

  Such an ink jet recording apparatus can cope with various types of printing with ink droplets ejected from the nozzle openings of the print head, so that the ink cartridge can be replaced according to the printing purpose. That is, when printing is performed with a different type of ink from the currently installed ink cartridge, the currently installed ink cartridge is temporarily removed and replaced with an ink cartridge having a desired type of ink. It can be remounted. In such a situation, it is considered that there may frequently be a demand for printing with different print quality at any time using the same printer using different ink types.

  However, the replacement of the ink cartridge is a cumbersome operation for the user of the recording apparatus, and when the number of cartridges to be replaced increases, the cumbersome operation must be performed many times.

  Therefore, as a printing apparatus capable of changing the ink ejected from each nozzle row without replacing the ink cartridge, a printing apparatus having a switching unit that switches the ink cartridge communicated with the recording head has been proposed ( For example, the following patent document 1). There has also been proposed a printing apparatus provided with a switching unit that can switch between ink and cleaning liquid and introduce it into a recording head (for example, Patent Documents 1 and 2 below).

When switching the ink in these conventional apparatuses, (1) a method of introducing and replacing new ink as it is from the previous ink, and (2) a method of introducing new ink after once discharging the previous ink. Two methods were taken.
JP 2001-219574 A JP 59-127767 A

  However, (1) in the method in which new ink is introduced and replaced as it is from the previous ink, the previous ink and the new ink are mixed during the liquid replacement, so that the amount of ink required for ink replacement In addition, there is a problem that the probability of color mixing increases and the print quality is likely to deteriorate.

  Further, (2) in the method in which the previous ink is once discharged and then the new ink is introduced, when the previous ink is once discharged and the flow path in the recording head is emptied, depending on the type of ink, Then, the ink bubbles, and when new ink is introduced next, the bubbles are not completely discharged, the filling property is liable to deteriorate, and the printing quality such as missing dots is likely to be deteriorated. In particular, in the case of ink that is relatively easy to foam, such as photo black for glossy paper with less antifoaming agent, the tendency is strong, and the method (2) cannot be adopted.

  On the other hand, before the printing apparatus is shipped, after a printing test is performed, the ink in the ejection head is once washed away with a cleaning liquid and a quality retaining liquid is introduced. In this pre-shipping cleaning process, two methods are also used: (1) a method of introducing a cleaning liquid as it is from the previous ink, and (2) a method of discharging the previous ink and then introducing the cleaning liquid. Has been adopted.

  However, in the method of (1) introducing the cleaning liquid from the previous ink as it is and cleaning, the ink and the cleaning liquid are mixed during the liquid replacement, and the amount of the cleaning liquid consumed is very large. In addition, there was a problem that it took a long time for cleaning.

  Further, (2) in the method in which the previous ink is once discharged and the cleaning liquid is introduced, when the previous ink is once discharged and the flow path in the recording head is emptied, depending on the type of ink, There was a problem that the ink bubbled and the bubbles were not easily discharged when the cleaning liquid was introduced next, and the cleaning performance was poor, resulting in an increase in the amount of cleaning liquid consumed and a long cleaning time.

  The present invention has been made in view of such circumstances, and when replacing the liquid in the ejecting head, the liquid in the ejecting head is once diluted with the liquid after replacement, and then discharged, thereby being consumed for replacement. A first object is to provide a liquid ejecting apparatus and a liquid switching method for the liquid ejecting apparatus that reduce the amount of liquid and eliminate filling failure due to foaming.

  In the present invention, when the liquid in the ejection head is replaced and cleaned, the liquid in the ejection head is once diluted with a cleaning liquid and then discharged, thereby reducing the amount of cleaning liquid consumed for replacement and causing foaming. A second object is to provide a method for cleaning an ejection head in a liquid ejecting apparatus that can eliminate defective cleaning and can reduce the cleaning time.

In order to achieve the above object, a liquid ejecting apparatus of the present invention includes an ejection head that ejects liquid from a nozzle to an ejection target, and a suction that sucks and discharges liquid by applying a negative pressure to the nozzle of the ejection head. Means, opening and closing means for opening and closing a plurality of supply passages for supplying liquid to the ejection head, and air release means for opening the inside of the ejection head to the atmosphere when suctioning by the suction means,
When the liquid supplied to the ejection head is switched from the first liquid to the second liquid by the opening / closing operation of the first opening / closing means and the second opening / closing means,
With the first opening / closing means closed and the second opening / closing means opened, the first liquid filled in the ejection head is diluted with the second liquid by suction with the suction means,
With the second opening / closing means closed and the atmosphere opening means opened, the liquid in the ejection head is discharged by suction with the suction means,
The gist is to execute the first switching control in which the ejection head is filled with the second liquid by sucking with the suction means in a state where the atmosphere opening means is closed and the second opening / closing means is opened.

  That is, the liquid ejecting apparatus according to the aspect of the invention, when switching the liquid supplied to the ejecting head from the first liquid to the second liquid, once dilutes the first liquid filled in the ejecting head with the second liquid and then discharges it. Therefore, for example, even if the first liquid is easily foamed, the foaming is suppressed by dilution with the second liquid, and the filling failure and the ejection failure due to the remaining foam do not occur as in the conventional case. Since the second liquid is filled after the flow path is emptied while suppressing foaming, the first liquid and the second liquid do not mix, so only a small amount of liquid is required to replace the liquid. Troubles caused by mixing can be avoided.

In the liquid ejecting apparatus of the present invention, when the liquid supplied to the ejecting head is switched from the second liquid to the first liquid by the opening / closing operation of the first opening / closing means and the second opening / closing means,
With the second opening / closing means closed and the atmosphere opening means opened, the liquid in the ejection head is discharged by suction with the suction means,
When performing the second switching control for filling the first liquid in the ejection head by sucking with the suction means in a state where the air opening means is closed and the first opening / closing means is opened,
For example, when it is not necessary to once dilute the liquid before discharging such as the second liquid is relatively difficult to foam, the amount of liquid consumed for liquid replacement can be saved by omitting the dilution.

In the liquid ejecting apparatus according to the aspect of the invention, in the case of including a selection execution unit that selects and executes the first switching control and the second switching control,
By selecting and executing the first switching control and the second switching control according to the combination of the first liquid and the second liquid, appropriate liquid replacement is always performed, and the amount of liquid consumed for liquid replacement is reduced. In addition, ejection failure and filling failure can be prevented.

  In the liquid ejecting apparatus of the present invention, when information on the type and combination of the first liquid and / or the second liquid is acquired and the first liquid is diluted with the second liquid, an appropriate suction time according to the acquired information If you do not need to dilute too much, you can reduce the ink consumed by dilution by shortening the suction time.If you need to dilute sufficiently, increase the suction time. The effect of dilution can be obtained reliably.

  In the liquid ejecting apparatus of the present invention, when the environmental temperature is detected by the environmental temperature detecting means and the first liquid is diluted with the second liquid, the suction time is controlled to be longer as the detected environmental temperature is higher. In the high temperature environment, the liquid is more likely to foam, so in the high temperature environment, the suction time is lengthened to ensure the effect of dilution, and in the low temperature environment, the ink consumed for dilution is shortened. Can be saved.

In the liquid ejecting apparatus according to the aspect of the invention, when the first liquid and the second liquid are a combination of liquids in which the first liquid is more easily foamed than the second liquid,
By performing the first switching control when switching from the first liquid relatively easy to foam to the second liquid, and executing the second switching control when switching from the second liquid relatively difficult to foam to the first liquid, Appropriate liquid replacement is always performed, and the amount of liquid consumed for liquid replacement can be reduced, and discharge failure and filling failure can be prevented.

In the liquid ejecting apparatus of the present invention, when the second liquid is a cleaning liquid for cleaning the inside of the ejecting head,
When cleaning the ejection head by replacing the first liquid with the cleaning liquid, the first switching control is executed, for example, even if the first liquid is likely to foam, the foaming is suppressed by dilution with the cleaning liquid, As in the conventional case, poor cleaning due to residual foam does not occur. In addition, since the cleaning liquid is filled after emptying the flow path while suppressing foaming, the first liquid and the cleaning liquid do not mix, so the amount of cleaning liquid required to replace the liquid is small and the cleaning time is greatly shortened. be able to.

In the liquid ejecting apparatus according to the aspect of the invention, when the first liquid and the second liquid are a combination of inks that are relatively darker than the second liquid,
When switching from the relatively dark first ink to the second ink, the first switching control is executed, and the dark first ink is diluted with the second ink to lighten the color, and then discharged. Since the second ink is introduced, the remaining of the first ink can be reduced, and troubles due to color mixing can be avoided. In addition, the amount of ink consumed as the ink is switched can be greatly reduced. In addition, when switching from the relatively light second ink to the first ink, since it is not necessary to dilute before discharging, the second switching control is executed to omit the dilution, and the amount of ink consumed for ink switching Can be saved.

In order to achieve the above object, a liquid replacement method for a first liquid ejecting apparatus of the present invention is a liquid switching method for a liquid ejecting apparatus including an ejecting head that ejects liquid from a nozzle onto an ejected object,
When switching the liquid supplied to the ejection head from the first liquid to the second liquid,
In the state where the supply of the first liquid to the ejection head is shut off and the state is switched to the state where the second liquid is supplied, a negative pressure is applied to the nozzle of the ejection head to suck the first liquid filled in the ejection head. Dilute one liquid with a second liquid,
In a state where the supply of the second liquid is shut off and the inside of the ejection head is opened to the atmosphere, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
In a state in which the air release state is stopped and the state in which the second liquid is supplied to the ejection head is switched, a negative pressure is applied to the nozzle of the ejection head to suck the second liquid into the ejection head. The gist is to fill.

  That is, in the liquid replacement method for the first liquid ejecting apparatus of the present invention, when the liquid supplied to the ejecting head is switched from the first liquid to the second liquid, the first liquid filled in the ejecting head is changed to the second liquid. For example, even if the first liquid is likely to foam, the foaming can be suppressed by dilution with the second liquid. No longer occurs. Since the second liquid is filled after the flow path is emptied while suppressing foaming, the first liquid and the second liquid do not mix, so only a small amount of liquid is required to replace the liquid. Troubles caused by mixing can be avoided.

In the liquid replacement method of the first liquid ejecting apparatus of the present invention, when the liquid supplied to the ejecting head is switched from the second liquid to the first liquid,
In a state where the supply of the second liquid is shut off and the inside of the ejection head is opened to the atmosphere, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
In a state where the air release state is stopped and the state in which the first liquid is supplied to the ejection head is switched, a negative pressure is applied to the nozzle of the ejection head to suck the first liquid into the ejection head. When filling
For example, when it is not necessary to once dilute the liquid before discharging such as the second liquid is relatively difficult to foam, the amount of liquid consumed for liquid replacement can be saved by omitting the dilution.

The liquid replacement method of the second liquid ejecting apparatus of the present invention includes an ejecting head that ejects liquid from a nozzle to an ejected object, and a plurality of supply channels for supplying liquid to the ejecting head. A liquid switching method for a liquid ejecting apparatus, comprising: opening / closing means for opening and closing; and air release means for releasing the inside of the ejection head to the atmosphere during suction by the suction means,
When the liquid supplied to the ejection head is switched from the first liquid to the second liquid by the opening / closing operation of the first opening / closing means and the second opening / closing means,
With the first opening / closing means closed and the second opening / closing means opened, the first liquid filled in the ejection head is diluted with the second liquid by applying a negative pressure to the nozzle of the ejection head and sucking it. And
With the second opening / closing means closed and the air release means opened, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
The gist of the invention is to fill the ejection head with the second liquid by applying a negative pressure to the nozzle of the ejection head with the atmosphere opening means closed and the second opening / closing means opened.

  That is, in the liquid replacement method of the second liquid ejecting apparatus of the present invention, when the liquid supplied to the ejecting head is switched from the first liquid to the second liquid, the first liquid filled in the ejecting head is changed to the second liquid. For example, even if the first liquid is likely to foam, the foaming can be suppressed by dilution with the second liquid. No longer occurs. Since the second liquid is filled after the flow path is emptied while suppressing foaming, the first liquid and the second liquid do not mix, so only a small amount of liquid is required to replace the liquid. Troubles caused by mixing can be avoided.

In the liquid replacement method of the second liquid ejecting apparatus of the present invention, when the liquid supplied to the ejecting head is switched from the second liquid to the first liquid by the opening / closing operation of the first opening / closing means and the second opening / closing means,
With the second opening / closing means closed and the air release means opened, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
When filling the first liquid in the ejecting head by applying a negative pressure to the nozzle of the ejecting head with the air opening means closed and the first opening / closing means opened,
For example, when it is not necessary to once dilute the liquid before discharging such as the second liquid is relatively difficult to foam, the amount of liquid consumed for liquid replacement can be saved by omitting the dilution.

In order to achieve the above object, a cleaning method for an ejection head in a first liquid ejecting apparatus of the present invention is a cleaning method for an ejection head in a liquid ejecting apparatus including an ejection head that ejects liquid from a nozzle onto an ejection target. There,
When cleaning the inside of the jet head by discharging the liquid filled in the jet head,
The liquid filled in the ejection head is diluted with the cleaning liquid by applying a negative pressure to the nozzle of the ejection head and sucking in the state where the liquid supply to the ejection head is shut off and the cleaning liquid is supplied. And
In a state where the supply of the cleaning liquid is shut off and the inside of the jet head is opened to the atmosphere, the liquid in the jet head is discharged by applying a negative pressure to the nozzle of the jet head and sucking it,
The cleaning liquid is introduced into the ejection head by applying a negative pressure to the nozzle of the ejection head and sucking the nozzle while the air release state is stopped and the cleaning liquid is supplied to the ejection head. Is the gist.

  That is, in the first liquid ejecting apparatus of the present invention, the cleaning method for the ejecting head discharges the liquid filled in the ejecting head and cleans the ejecting head with the cleaning liquid. Since the liquid is once diluted and then discharged, for example, even if the liquid is liable to foam, the foaming is suppressed by dilution with the cleaning liquid, and the conventional defective cleaning due to the remaining foam does not occur. And since the cleaning liquid is filled after emptying the flow path while suppressing foaming, the liquid and cleaning liquid do not mix, so the amount of cleaning liquid required to replace the liquid can be reduced and the cleaning time can be greatly shortened. it can.

The method for cleaning an ejection head in the second liquid ejection apparatus of the present invention includes an ejection head that ejects liquid from a nozzle onto an ejection target, and a plurality of supply flows for supplying liquid to the ejection head. An ejecting head cleaning method in a liquid ejecting apparatus, comprising: an opening / closing means for opening and closing a path; and an air opening means for opening the inside of the ejecting head to the atmosphere at the time of suction by the suction means,
When cleaning the inside of the jet head by discharging the liquid filled in the jet head,
With the first opening / closing means closed and the second opening / closing means opened, the liquid filled in the ejection head is diluted with a cleaning liquid by applying a negative pressure to the nozzles of the ejection head and sucking them.
With the second opening / closing means closed and the air release means opened, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
The gist is to introduce the cleaning liquid into the ejecting head by applying a negative pressure to the nozzle of the ejecting head and sucking it with the air opening means closed and the second opening / closing means opened.

  That is, in the second liquid ejecting apparatus of the present invention, the cleaning method of the ejecting head discharges the liquid filled in the ejecting head and cleans the ejecting head with the cleaning liquid. Since the liquid is once diluted and then discharged, for example, even if the liquid is liable to foam, the foaming is suppressed by dilution with the cleaning liquid, and the conventional defective cleaning due to the remaining foam does not occur. And since the cleaning liquid is filled after emptying the flow path while suppressing foaming, the liquid and cleaning liquid do not mix, so the amount of cleaning liquid required to replace the liquid can be reduced and the cleaning time can be greatly shortened. it can.

  Next, embodiments of the present invention will be described in detail.

  Hereinafter, an embodiment of an ink jet printer as a liquid ejecting apparatus embodying the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic plan view of an ink jet printer main body 1 provided in a case (not shown) of an ink jet printer.

  The printer main body 1 includes a recording head 30 (see FIG. 2) as an ejection head that ejects liquid ink from nozzles onto a recording paper (not shown) that is an ejection target. On the other hand, a plurality of cartridges 2a to 2h for supplying liquid are mounted. Each of the cartridges 2a to 2h is provided with a holder and a guide plate (not shown) and is disposed in the non-printing area.

  In the following description, when referring to each of a plurality of cartridges, description will be made by using a combination of numerals and alphabetical characters such as “cartridge 2a” and “cartridge 2b”, but not individual cartridges. In this case, the description will be made using “cartridge 2” and a reference numeral only. The same applies to other members.

  The cartridges 2a to 2h correspond to the number of inks used, and in this embodiment, eight cartridges 2a to 2h are mounted. An ink pack (not shown) in which ink is stored is provided inside the cartridges 2a to 2h, and the ink in the ink pack passes through pressure adjusting units 5a to 5d having self-sealing valves (pressure reducing valves). Thus, the recording head 30 is configured to be supplied.

  The pressure adjusting units 5 a to 5 d are provided on the carriage 3 in accordance with the number of ink ejected from the recording head 30. In the present embodiment, a total of four pressure adjustment units 5 a to 5 d are mounted on the carriage 3. The pressure adjusters 5 a to 5 d are configured to be able to supply liquid such as ink supplied through the replenishment tubes 4 a to 4 d to the recording head 30 mounted on the lower surface of the carriage 3.

  In this example, basically four types of inks of yellow, magenta, cyan, and black are ejected, and four supply tubes 4a to 4d and four pressure adjusting portions 5a to 5d are provided corresponding to each ink. It has been. The pressure adjusting units 5a to 5d supply ink or the like corresponding to the four nozzle rows 25a to 25d (see FIG. 2) formed on the nozzle forming surface of the recording head 30.

  The carriage 3 on which the pressure adjusting units 5a to 5d are mounted is driven by the carriage motor 6 and guided by the scanning guide member 8 through the timing belt 7 to the longitudinal direction of the paper feeding member 9, that is, the recording paper. It is configured to reciprocate in the main scanning direction which is the width direction.

  On the other hand, a cap member 10 as a sealing means, a suction pump 11 (see FIG. 2), and a waste liquid tank 12 are arranged in a non-printing area on the movement path of the carriage 3. The cap member 10 is made of a flexible material such as rubber. When the carriage 3 moves to the non-printing area, the nozzle forming surface of the recording head 30 is sealed by the cap member 10. For this reason, the cap member 10 functions as a lid that prevents drying of the nozzle openings of the recording head 30 during the pause period of the printer main body 1.

  The bottom surface of the cap member 10 is connected to the suction pump 11 via a tube 13 (see FIG. 2). The suction pump 11 functions as a suction unit that sucks the space in the cap member 10 to apply the negative pressure generated by the suction pump 11 to the nozzles of the recording head 30 and sucks and discharges liquid from the recording head 30 side. . The ink sucked by the suction pump 11 is collected in the waste liquid tank 12. Further, a wiping member 14 made of an elastic material such as rubber is disposed on the printing region side of the cap member 10 so that the nozzle forming surface of the recording head 30 can be wiped and cleaned as necessary. .

  In this example, the eight cartridges 2a to 2h are ink cartridges for supplying ink to the recording head 30. Specifically, the cartridge 2a is a first yellow ink (Y1) ink cartridge, and the cartridge 2b is a cartridge 2b. The second yellow ink (Y2) ink cartridge, the cartridge 2c is the first magenta ink (M1) ink cartridge, the cartridge 2d is the second magenta ink (M2) ink cartridge, and the cartridge 2e is the first cyan ink (C1). The ink cartridge, the cartridge 2f may be an ink cartridge of the second cyan ink (C2), the cartridge 2g may be an ink cartridge of the first black ink (B1), and the cartridge 2h may be an ink cartridge of the second black ink (B2). .

  In this example, for example, for yellow, cyan, and magenta color inks, dye ink and pigment ink can be switched and used according to the type and purpose of the recording paper to be used. For black ink, the first ink is a photo black ink for glossy paper, the second ink is a mat black ink for mat paper, and is switched according to the type of recording paper using the photo black ink and the mat black ink. Can be used.

  At this time, the photo black ink that is the first ink A as the first liquid of the present invention is an ink that is relatively easier to foam than the mat black ink that is the second ink B as the second liquid of the present invention, Hereinafter, in the description of the first embodiment, a description will be mainly given of a combination of the first ink A and the second liquid B that are relatively easy to foam and the second ink B that is relatively difficult to foam.

  The printer main body 1 selects ink to be supplied to the recording head 30 by selecting a supply channel that communicates with the recording head 30 among supply channels for supplying ink from the cartridges 2a to 2h to the recording head 30. Switching means 16a to 16d for selectively switching between. Here, the supply flow paths are the cartridge tubes 15a to 15h.

  Four switching means 16 a to 16 d are provided corresponding to the four nozzle rows 25 a to 25 d and the pressure adjusting units 5 a to 5 d provided in the recording head 30. One switching means 16a to 16d is connected to the pressure adjusting portions 5a to 5d via one supply tube 4a to 4d, and connected to two cartridges 2a to 2h via two cartridge tubes 15a to 15h. Has been.

  Therefore, the switching means 16a to 16d are for selecting ink to be used from two types of ink. Specifically, the switching means 16a communicates with the cartridge 2a for the first yellow ink (Y1) and the cartridge 2b for the second yellow ink (Y2) to switch the ink to be used from these two types of ink. The switching means 16b communicates with the cartridge 2c of the first magenta ink (M1) and the cartridge 2d of the second magenta ink (M2) and switches the ink to be used from these two types of ink. The switching means 16c communicates with the cartridge 2e for the first cyan ink (C1) and the cartridge 2f for the second cyan ink (C2) to switch the ink to be used from these two types of ink. The switching means 16d communicates with the cartridge 2g of the first black ink (B1) and the cartridge 2h of the second black ink (B2) and switches the ink to be used from these two types of ink.

  2 and 3 show a recording head 30 which is mounted on the carriage 3 and ejects ink as a liquid onto a recording paper which is an ejection target, and pressure adjusting units 5a to 5d mounted on the recording head 30. FIG. It is a thing.

  The recording head 30 includes a filter case 33 having a filter 32 for filtering the liquid to be ejected, and a head body 34 attached to the lower surface of the filter case 33.

  Four hollow ink supply needles 31 are arranged in an upright state on the upper surface of the filter case 33, and each ink communication channel 35 formed in the filter case 33 is connected to each ink supply needle. 31 communicates with the ink flow path. An ink introduction hole 31a is formed at the top of each ink supply needle 31, and ink from the pressure adjusting portions 5a to 5d is introduced into the ink supply needle 31 through the ink introduction hole 31a, and the ink communication is performed. It is supplied to the head main body 34 via the flow path 35 and ejected from the nozzle openings of the nozzle rows 25a to 25d. Accordingly, the pressure adjusting units 5a to 5d, the ink supply needle 31, and the ink communication channel 35 correspond to the nozzle rows 25a to 25d.

  The ink supply needles 31 are arranged so as to be arranged at a predetermined interval in accordance with the arrangement state of the pressure adjusting units 5a to 5d. On the other hand, since the width dimension of the head body 34 to which ink is supplied is smaller than that, the ink communication channel 35 arranged outside the ink communication channel 35 arranged inside is the inclination angle of the channel. Is getting bigger.

  A self-sealing valve (pressure reducing valve) 37 is accommodated in the pressure adjusting unit 5. By the operation of the self-sealing valve 37, the pressure of ink sent from the cartridges 2a to 2h to the recording head 30 side through the ink supply needle 31 through the cartridge tubes 15a to 15h is reduced and adjusted. For example, when pressure fluctuations occur in the ink in the cartridge tubes 15a to 15h as the carriage 3 is accelerated and decelerated, the ejection of ink droplets becomes unstable, so the pressure adjustment unit 5 suppresses ink pressure fluctuations. .

  FIG. 4 shows an example of a switching valve that can be used as the switching means 16.

  4A is a cross-sectional view, and FIG. 4B is a front view. 201 is a switching valve housing, 202 is an inlet / outlet plate, 200 is a valve packing holder, 210 is a rubber valve packing, and 220 is a spring. The valve packing holder 200 holds the valve packing 210. A spring 220 mounted in the switching valve housing 201 presses the valve packing holder 200. Accordingly, the valve packing 210 is held between the valve packing holder 200 and the inlet / outlet plate 202. The entrance / exit plate 202 is provided with an opening 230 connected to the recording head 30 via the supply tube 4 at the center thereof. Around the opening 230, openings 240 and 260 connected to the cartridges 2 of different types of liquids via the cartridge tube 15 and an opening 250 opened to the atmosphere are provided.

  In the state shown in the figure, the opening 240 and the opening 230 communicate with each other through the flow path 280, and the other three openings 250 and 260 and the opening 230 do not communicate with each other. When the tail portion 290 of the valve packing holder 200 is rotated from this state, the position of the flow path 280 is changed, the opening communicating with the opening 230 connected to the recording head 30 is moved from the opening 240 to the opening 250, and the tail portion 290 is further moved. When rotated 90 degrees, the opening communicating with the opening 230 moves from the opening 250 to the opening 260. When the tail 290 is further rotated 180 degrees, the opening communicating with the opening 230 moves from the opening 260 to the original opening 240. As described above, the opening communicating with the recording head 30 by the rotation of the tail 290 can be switched to the opening 240, the opening 250, and the opening 260.

  In the present embodiment, the switching means 16 includes four corresponding to the ink colors to be ejected. The openings 230 of the four switching means 16 are connected to the four supply tubes 4 respectively.

  The following description will focus on one system among the four ink supply paths (ink cartridge 2 to cartridge tube 15 to switching means 16 to recording head 30) provided according to the ink color. The same applies to these three systems.

  In the switching means 16, the opening 240 communicates with the ink cartridge A that supplies the first ink A, and the opening 260 communicates with the ink cartridge B that supplies the second ink B. The opening 250 is opened to the atmosphere via an atmosphere opening tube.

  That is, the switching unit 16 functions as an opening / closing unit that opens and closes the cartridge tube 15 that is a plurality of supply passages for supplying liquid to the recording head 30, and the suction unit 11 performs the above-described operation when suction is performed. It functions as an air release means for releasing the inside of the recording head 30 to the atmosphere.

  Therefore, the portion of the switching unit 16 that opens and closes the opening 240 functions as a first opening / closing unit that opens and closes the first supply flow path for supplying the first ink A to the recording head 30. The portion that opens and closes the opening 260 functions as a second opening / closing means that opens and closes the second supply channel for supplying the second ink B to the recording head 30. A portion of the switching unit 16 that opens and closes the opening 250 functions as an air release unit that opens the recording head 30 to the atmosphere.

  FIG. 5 schematically shows the configuration of the ink supply path (ink cartridge 2 to cartridge tube 15 to switching means 16 to recording head 30). The first opening / closing means 21 opens and closes the cartridge tube 15 that supplies the first ink A, and the second opening / closing means 22 opens and closes the cartridge tube 15 that supplies the second ink B. The atmosphere release means 20 opens the recording head 30 to the atmosphere.

  Thus, the ink supplied to the recording head 30 is switched from the first ink A to the second ink B or the second ink B is changed to the first ink A by the opening / closing operation of the first opening / closing means 21 and the second opening / closing means 22. Can be switched.

  Further, by closing the first opening / closing means 21 and the second opening / closing means 22 and opening the atmosphere opening means 20, the nozzle surface of the recording head 30 is sealed with the cap member 10 and the suction pump 11 is driven. The ink filled in the recording head 30 can be discharged to empty the recording head 30.

  The switching means 16 may be an electromagnetic valve using electromagnetics. In the printer body 1, the switching unit 16 is arranged independently for easy understanding, but it is not always necessary to arrange the switching means 16 independently, and it may be arranged in the recording head 30.

  FIG. 5 shows an example of a control circuit mounted on the recording apparatus described above.

  In the figure, reference numeral 47 denotes a print control means 47. This print control means 47 generates bitmap data based on print data from the host computer, and the carriage control means 44 controls the carriage motor 6 based on this data. A function of driving and reciprocating the carriage 3 and generating a drive signal by the head driving means 51 to eject ink droplets from the recording head 30 are provided. The head drive means 51 is configured to receive a flushing command signal from a flushing control means (not shown) in addition to a drive signal based on the print data and output a drive signal for the flushing operation to the recording head 30. Yes.

  Reference numeral 43 denotes an ink switching control unit 43. The ink switching control unit 43 starts control by operating an ink switching command switch 46 disposed on an operation panel or the like of the recording apparatus, and an ink switching operation is executed. It is comprised so that. The ink switching control means 43 is also configured to start control by an operation with a printer driver provided in the host and to execute an ink switching operation.

  The ink switching control unit 43 outputs control signals to the carriage control unit 44, the valve control unit 49, the lifting device 45, the pump driving unit 50, the wiping control unit 48, and the head driving unit 51, respectively, during the ink switching control. Ink switching control is executed.

  The carriage control unit 44 receives a control signal from the ink switching control unit 43 and drives the carriage motor 6 to control the movement of the carriage 3 so that the recording head 30 faces the cap member 10 (home position). ) To move the carriage 3.

  The valve control unit 49 receives the control signal from the ink switching control unit 43 and performs switching control of the switching unit 16 to control opening / closing of the first opening / closing unit 21, opening / closing control of the second opening / closing unit 22, and release to the atmosphere. The opening / closing control of the means 20 is performed.

  Specifically, the valve packing holder 200 is rotated to change the position of the flow path 280, and the opening 240, the opening 250, and the opening 260 that communicate with the opening 230 that communicates with the recording head 30 are selected. When the opening 230 communicating with the recording head 30, the ink cartridge 2 supplying the first ink A, and the opening 240 are in communication, the first opening / closing means 21 is opened, and the second opening / closing means 22 and the atmosphere opening means 20 are closed. It is a state. When the opening 230 communicating with the recording head 30, the ink cartridge 2 supplying the second ink B, and the opening 260 are in communication, the second opening / closing means 21 is opened, and the first opening / closing means 22 and the atmosphere opening means 20 are closed. It is a state. The state where the opening 230 communicating with the recording head 30 and the opening 250 opened to the atmosphere are in communication is the state where the first opening / closing means 21 and the second opening / closing means 22 are closed and the atmosphere opening means 20 is opened.

  The lifting device 45 receives the control signal from the ink switching control means 43 and moves the cap member 10 up and down to seal the nozzle surface of the recording head 30 so that the ink in the recording head 30 can be sucked. Similarly, when cleaning is performed by a cleaning control unit (not shown), the cap member 10 is moved up and down to seal the nozzle surface of the recording head 30.

  The pump driving unit 50 receives the control signal from the ink switching control unit 43, sucks the inside of the cap member 10 in a state where the nozzle surface of the recording head 30 is sealed, and applies a negative pressure to the nozzle to thereby generate the inside of the recording head 30. Aspirate the ink. Similarly, when cleaning is performed by a cleaning control unit (not shown), the inside of the cap member 10 is sucked to discharge the ink of the recording head 30 by suction.

  The wiping control means 48 receives the control signal from the ink switching control means 43 and controls the movement of the wiping member 14 and the carriage 3 with the cap member 10 lowered and opened after the suction by the suction pump 11. The nozzle surface of the recording head 30 is wiped off. Similarly, when cleaning is performed by a cleaning control unit (not shown), the nozzle surface of the recording head 30 after cleaning is wiped off.

  The ink switching control unit 43 performs the following first switching control when switching the ink supplied to the recording head 30 from the first ink A to the second ink B.

  At this time, the initial state is a state in which the first ink A is supplied and filled in the recording head 30, and the switching means 16 has the first opening / closing means 21 open, the second opening / closing means 22 and the atmosphere opening means 20 being opened. Closed state.

  From this state, first, the first opening / closing means 21 is closed and the second opening / closing means 22 is opened, and suction is performed by the suction pump 11 in this state. By this suction, the ink in the recording head 30 is forcibly sucked and discharged from the nozzle, and the second ink B is introduced into the recording head 30 from the cartridge 2 that supplies the second ink B communicated with the second opening / closing means 22. . By the discharge of the first ink A and the introduction of the second ink B, the first ink A filled in the recording head 30 is replaced to some extent by the second ink B, and the first ink A is largely replaced by the second ink B. It will be in a diluted state.

  At this time, if the first ink A is a combination of an ink that easily foams (for example, photo black) and an ink that the second ink B does not easily foam (for example, matte black), the first ink A that tends to foam is the second ink B that is less likely to foam. As a result of the dilution, the liquid in the recording head 30 is less likely to foam.

  The degree of dilution can be controlled by the suction time in the suction pump 11. If the suction time is lengthened, the degree of dilution increases and the remaining amount of the first ink A decreases. If the suction time is shortened, the degree of dilution decreases and the remaining amount of the first ink A increases.

  The first ink A and the second ink B can be set as appropriate according to the type and combination of the inks. At this time, it is preferable to select and input the type and combination of ink with a printer driver so that the information is acquired and an appropriate suction time is set accordingly. By doing this, if it is not necessary to dilute much, the suction time is shortened to reduce the ink consumed for dilution, and if it is necessary to dilute sufficiently, the suction time is lengthened to effect the dilution. Can be definitely obtained.

  Further, since ink tends to foam more easily in a high temperature environment, the ambient temperature can be detected by an ambient temperature detection unit (not shown), and the suction time can be controlled to increase as the ambient temperature increases accordingly. By doing so, it is possible to reliably obtain the effect of dilution by increasing the suction time in a high temperature environment, and to reduce the ink consumed for dilution by shortening the suction time in a low temperature environment.

  Next, the second opening / closing means 22 is closed and the air release means 20 is opened, and suction is performed by the suction pump 11 in this state. By this suction, the ink in the recording head 30 is forcibly sucked and discharged from the nozzles, and air is introduced into the recording head 30 from the air release means 20 and the ink in the recording head 30 is discharged. At this time, since the first ink A which is easily bubbled and originally filled in the recording head 30 is diluted with the second ink B which does not easily foam, air is introduced into the recording head 30 from the air release means 20 and is emptied. Even in this case, foaming in the flow path can be suppressed.

  Then, the air opening means 20 is closed and the second opening / closing means 22 is opened. In this state, suction is performed by the suction pump 11, thereby applying a negative pressure to the recording head 30 and communicating with the second opening / closing means 22. The second ink B is introduced into the recording head 30 from the cartridge 2 that supplies B, and the second ink B is filled into the recording head 30.

  The ink switching control means 43 executes the following second switching control when switching the ink supplied to the recording head 30 from the second ink B to the first ink A, contrary to the switching described above. .

  At this time, the initial state is a state in which the recording head 30 is supplied and filled with the second ink B, and the switching means 16 has the second opening / closing means 22 open, the first opening / closing means 21 and the atmosphere opening means 20 being open. Closed state.

  From this state, the second opening / closing means 22 is closed and the air release means 20 is opened, and suction is performed by the suction pump 11 in this state. By this suction, the ink in the recording head 30 is forcibly sucked and discharged from the nozzles, and air is introduced into the recording head 30 from the atmosphere release means 20 and the second ink B in the recording head 30 is discharged.

  At this time, since the ink originally filled in the recording head 30 is the second ink B which is hard to foam, even if air is introduced into the recording head 30 from the air release means 20 and becomes empty, There is little bubbling.

  Next, the air opening means 20 is closed and the first opening / closing means 21 is opened, and suction is performed by the suction pump 11 in this state. By this suction, the first ink A is introduced into the recording head 30 from the cartridge 2 that applies a negative pressure to the recording head 30 and supplies the first ink A communicated with the first opening / closing means 21. The first ink A is filled.

  The first switching control executed when switching from the first ink A to the second ink B and the second switching control executed when switching from the second ink B to the first ink A are selected and executed. It is desirable to provide selection execution means. Specifically, the selection execution unit may select and execute the first switching control or the second switching control on the operation screen of the printer driver, or may be performed on the operation panel of the recording apparatus, etc. Two ink switching command switches 46 for executing the first switching control and the ink switching command switch 46 for executing the second switching control may be provided.

  FIG. 6 is a flowchart for explaining a specific example of the first switching control executed when the liquid switching method of the liquid ejecting apparatus of the present invention is applied and the first ink A is switched to the second ink B.

  First, when the ink switch command switch 46 is pressed (S1), the carriage 3 moves to the home position (S2), and the cap member 10 is raised to close the cap (S3). Subsequently, the valve operation of the switching means 16 is performed, the first opening / closing means 21 is closed, and the second opening / closing means is opened (S4). By this valve operation, the supply of the first ink A to the recording head 30 is shut off and the state is switched to the state of supplying the second ink B. At this time, the air release means 20 is in a closed state. Next, the suction pump 11 is driven to suck and discharge the first ink A from the nozzle, and the second ink B is introduced from the second opening / closing means 22 to dilute the first ink A with the second ink B (S5). .

  Then, the valve operation of the switching means 16 is performed, the second opening / closing means 22 is closed, and the atmosphere opening means 20 is opened (S6). By this valve operation, the supply of the second ink B is shut off and the inside of the recording head 30 is switched to a state in which it is opened to the atmosphere. At this time, the first opening / closing means 21 is in a closed state. In this state, the suction pump 11 is driven to suck and discharge the diluted ink from the nozzles, and air is introduced from the atmosphere release means 20 to discharge the ink (S7).

  Subsequently, the valve operation of the switching means 16 is performed, the second opening / closing means 22 is opened, and the atmosphere opening means 20 is closed (S8). By this valve operation, the atmospheric release state is stopped and the second ink B is supplied to the recording head 30. At this time, the first opening / closing means 21 is in a closed state. In this state, the suction pump 11 is driven to apply a negative pressure to the nozzles, and the second ink B is introduced into the recording head 30 via the second opening / closing means 22 and filled (S9).

  When the filling is completed, the cap member 10 is lowered to open the cap (S10), the suction pump 11 is driven to discharge the ink accumulated in the cap member 10 by idle suction (S11), and the wiping member 14 is raised. The nozzle 3 of the recording head 30 is wiped by slightly moving the carriage 3 (S12). Thereafter, flushing discharge is performed, and a series of control is terminated (S13).

  FIG. 7 is a flowchart illustrating a specific example of the second switching control executed when switching from the second ink B to the first ink A.

  First, when the ink switch command switch 46 is pressed (S21), the carriage 3 moves to the home position (S22), and the cap member 10 is raised to close the cap (S23). Subsequently, the valve operation of the switching means 16 is performed, the second opening / closing means 22 is closed, and the atmosphere opening means 20 is opened (S24). By this valve operation, the supply of the second ink B is shut off and the inside of the recording head 30 is switched to a state in which it is opened to the atmosphere. At this time, the first opening / closing means is in a closed state.

  In this state, the suction pump 11 is driven to suck and discharge the second ink B from the nozzle, and air is introduced from the atmosphere release means 20 to discharge the second ink B (S25).

  Subsequently, the valve operation of the switching means 16 is performed, the first opening / closing means 21 is opened, and the atmosphere opening means 20 is closed (S26). By this valve operation, the atmospheric release state is stopped and the state is switched to the state where the first ink A is supplied to the recording head 30. At this time, the second opening / closing means 22 is in a closed state. In this state, the suction pump 11 is driven to apply a negative pressure to the nozzles, and the first ink A is introduced into the recording head 30 via the first opening / closing means 21 and filled (S27).

  When the filling is completed, the cap member 10 is lowered to open the cap (S28), the suction pump 11 is driven to discharge the ink accumulated in the cap member 10 by empty suction (S29), and the wiping member 14 is raised. Then, the carriage 3 is moved slightly while wiping the nozzle surface of the recording head 30 (S30). Thereafter, flushing discharge is performed, and a series of control is finished (S31).

  In the above description, the present invention is applied to the case where the first ink A is an ink that easily foams and the second ink B is an ink that hardly foams. However, the present invention is not limited to this. For example, the present invention can also be applied to the case where dark ink is used as the first ink A and light ink is used as the second ink B. For example, the present invention can be applied to the case where ink is used as the first liquid and a functional liquid such as a cleaning liquid or a moisturizing liquid is used as the second liquid.

  According to the first embodiment, the following effects can be obtained.

  That is, according to the first embodiment, when the ink supplied to the recording head 30 is switched from the first ink A to the second ink B, the first ink A filled in the recording head 30 is changed to the second ink. For example, even if the first ink A is likely to foam, the foaming is suppressed by dilution with the second ink B. No discharge failure occurs. Since the second ink B is filled after the flow path is emptied while suppressing foaming, the first ink A and the second ink B are not mixed, so the amount of ink required for ink replacement is small. Troubles caused by mixing different types of ink can be avoided.

  When the ink supplied to the recording head 30 is switched from the second ink B to the first ink A by opening / closing the first opening / closing means and the second opening / closing means, the second opening / closing means is closed and the atmosphere opening means is opened. In this state, the ink in the recording head 30 is discharged by suctioning with the suction means, and the air opening means is closed and the first opening / closing means is opened. In order to execute the second switching control for filling one ink A, for example, when the second ink B does not need to be diluted once before being discharged, for example, the second ink B is relatively difficult to foam, the ink can be omitted by omitting the dilution. The amount of ink consumed for replacement can be saved.

  In addition, since selection execution means for selecting and executing the first switching control and the second switching control is provided, the first switching control and the second switching are performed according to the combination of the first ink A and the second ink B. By selecting and executing the control, it is possible to always perform appropriate ink replacement and reduce the amount of ink consumed for ink replacement, while preventing ejection failure and filling failure.

  In addition, when information on the type and combination of the first ink A and / or the second ink B is acquired and the first ink A is diluted with the second ink B, an appropriate suction time is set according to the acquired information. If you do not need to dilute much, reduce the ink consumed for dilution by shortening the suction time.If you need to dilute sufficiently, increase the suction time to reduce the dilution. An effect can be obtained reliably.

  Further, when the environmental temperature is detected by the environmental temperature detection means and the first ink A is diluted with the second ink B, the control is performed so that the suction time becomes longer as the detected environmental temperature becomes higher. Since liquid tends to foam more easily, the suction time is lengthened in a high temperature environment to ensure the effect of dilution, and in a low temperature environment, the suction time is shortened to reduce ink consumed for dilution. Can do.

  In addition, when the first ink A and the second ink B are a combination of inks that are more easily foamed than the second ink B, the first ink A and the second ink B are the first ink A to the second ink B that are relatively easy to foam. When switching to 2 ink B, the first switching control is executed, and when switching from the second ink B, which is relatively less likely to foam, to the first ink A, the second switching control is executed to always perform appropriate ink replacement. Further, it is possible to prevent ejection failure and filling failure while reducing the amount of ink consumed for ink replacement.

  Further, when the second liquid is a cleaning liquid for cleaning the inside of the recording head 30, the first switching control is executed when the recording head 30 is cleaned by replacing the ink as the first liquid with the cleaning liquid. For example, even if the ink is liable to foam, the foaming is suppressed by dilution with the cleaning liquid, and there is no occurrence of poor cleaning due to residual foam as in the prior art. And since the cleaning liquid is filled after emptying the flow path while suppressing foaming, the ink and cleaning liquid do not mix, so the amount of cleaning liquid required to replace the liquid is small, and the cleaning time can be greatly shortened. it can.

  The first ink A and the second ink B are relatively dark first ink A when the first ink A is a combination of relatively dark inks than the second ink B. When switching from the second ink B to the second ink B, the first switching control is executed to discharge the dark first ink A after diluting the color by dilution with the second ink B, and then the light second ink B is discharged. Since the introduction of the first ink A is reduced, it is possible to reduce the remaining of the first ink A, and it is possible to avoid a trouble due to color mixing. In addition, the amount of ink consumed as the ink is switched can be greatly reduced. Further, when switching from the relatively light second ink B to the first ink A, since it is not necessary to dilute before discharging, the second switching control is executed to omit the dilution and consume the ink for switching. The amount of ink can be saved.

  FIG. 8 shows a second embodiment of the present invention.

  This embodiment shows a state in which the cleaning method of the present invention is performed using ink as the first liquid and using a cleaning liquid as the second liquid.

  In this example, the cleaning method of the present invention is applied to so-called process cleaning. After a printing test is performed before the printing apparatus is shipped, the ink in the recording head 30 is once washed away with a cleaning liquid and a quality retaining liquid is introduced. The state of the cleaning process performed when performing is shown.

  In the figure, reference numeral 27 denotes a cleaning liquid tank 27 filled with a cleaning liquid, which supplies the cleaning liquid to the recording head 30 via a cleaning cartridge 26 mounted instead of the ink cartridge. Reference numeral 28 denotes a cleaning waste liquid tank 28. A tube connected to the waste liquid tank 12 of the recording apparatus is temporarily disconnected and connected to the cleaning waste liquid tank 28 to recover the cleaning waste liquid. A cleaning pump 29 is driven at the time of discharging the ink, introducing the cleaning liquid, and cleaning, and sucks the inside of the cap member 10 to apply a negative pressure to the nozzles of the recording head 30.

  The cleaning process for discharging the ink filled in the recording head 30 and cleaning the recording head 30 is performed as follows, for example.

  At this time, the initial state is a state in which ink is supplied to the recording head 30 and the switching unit 16 is in a state in which the first opening / closing unit 21 is open and the second opening / closing unit 22 and the air opening unit 20 are closed. It is.

  From this state, first, the first opening / closing means 21 is closed and the second opening / closing means 22 is opened. By this valve operation, the supply of ink to the recording head 30 is shut off and the state is switched to the state of supplying the cleaning liquid. In this state, the ink in the recording head 30 is forcibly sucked and discharged from the nozzles by being sucked by the cleaning pump 29, and the cleaning liquid is introduced into the recording head 30 from the cleaning cartridge 26 communicating with the second opening / closing means 22. Is done. By discharging the ink and introducing the cleaning liquid, the ink filled in the recording head 30 is replaced with the cleaning liquid to some extent, and the ink is greatly diluted with the cleaning liquid.

  Next, the second opening / closing means 22 is closed and the atmosphere opening means 20 is opened. By this valve operation, the supply of the cleaning liquid is shut off and the recording head 30 is switched to a state in which it is opened to the atmosphere. By sucking with the cleaning pump 29 in this state, the liquid in the recording head 30 is forcibly sucked and discharged from the nozzles, and air is introduced into the recording head 30 from the air release means 20 and the inside of the recording head 30 is discharged. Ink is discharged.

  Then, the air opening means 20 is closed and the second opening / closing means 22 is opened. By this valve operation, the air release state is stopped and the state is switched to the state in which the cleaning liquid is supplied to the recording head 30. By sucking with the cleaning pump 29 in this state, a negative pressure is applied to the recording head 30, the cleaning liquid is introduced into the recording head 30 from the cleaning cartridge 26 communicating with the second opening / closing means 22, and cleaning is started. The

  After cleaning for a predetermined time, the second opening / closing means 22 is closed again, the atmosphere opening means 20 is opened, and the liquid in the recording head 30 is forcibly sucked and discharged from the nozzles by suction with the cleaning pump 29 in that state. Then, air is introduced into the recording head 30 from the air release means 20 and the cleaning liquid in the recording head 30 is discharged, and the cleaning process ends.

  In the above-described example, the suction operation in the cleaning process is performed by the cleaning pump 29. However, suction may be performed by the suction pump 11 attached to the recording apparatus.

  The cleaning method of the present invention can also be applied to a recording apparatus without the switching means 16. In this case, switching from the ink to the cleaning liquid can be performed not by valve operation but by replacement from the ink cartridge 2 to the cleaning cartridge 26, and the air release of the recording head 30 is performed not by valve operation but by removal of the cartridge. be able to. It is also possible to prepare and perform a cleaning jig provided with a valve capable of switching such a state.

  According to the second embodiment, the following effects can be obtained.

  That is, according to the second embodiment, when the ink filled in the recording head 30 is discharged and the inside of the recording head 30 is cleaned, the ink filled in the recording head 30 is once diluted with the cleaning liquid. For example, even if the ink is liable to foam, the foaming is suppressed by dilution with the cleaning liquid, and there is no poor cleaning due to residual foam as in the prior art. And since the cleaning liquid is filled after emptying the flow path while suppressing foaming, the ink and cleaning liquid do not mix, so the amount of cleaning liquid required to replace the liquid is small, and the cleaning time can be greatly shortened. it can.

  Other than that, there exists an effect similar to 1st Embodiment.

  In each of the above-described embodiments, the example of application to switching between matte black and photo black or switching between dye ink and pigment ink has been described as an ink type, but the present invention is not limited to this, and other various inks are used. Can be used by switching. In addition to switching between inks, switching between functional liquids such as cleaning liquids and moisturizing liquids other than ink, and switching between ink and functional liquids can also be applied.

  In each of the above-described embodiments, the recording head 30 has shown an example in which a liquid ejecting apparatus using a piezoelectric vibrator is applied as a pressure generating element that is a driving element for ejecting liquid. However, the present invention is not limited to this. The present invention can also be applied to a liquid ejecting apparatus of a type using a heating element.

  Further, the program for causing the computer apparatus to execute the liquid switching processing method and the initial filling method executed by the liquid ejecting apparatus described above can be recorded in a recording medium and provided via a communication network. .

  In addition, as a typical example of the liquid ejecting apparatus, there is an ink jet recording apparatus provided with the above-described ink jet recording head for image recording. However, the present invention is an example of another liquid ejecting apparatus such as a liquid crystal display. Device with color material ejection head used for color filter production, device with electrode material (conductive paste) ejection head used for electrode formation such as organic EL display, surface emitting display (FED), etc., used for biochip production The present invention can be applied to various liquid ejecting apparatuses such as an apparatus having a biological organic matter ejecting head and an apparatus having a sample ejecting head as a precision pipette.

1 is a schematic plan view of a recording apparatus according to a first embodiment. It is a figure which shows the flow-path structure of a recording head. It is a partially broken sectional view showing a recording head and a pressure adjusting unit. It is a figure which shows a switching means, and is a figure explaining the connection state of (A) sectional drawing, (B) top view, (C) flow path. 3 is a functional block diagram illustrating a control circuit of the recording apparatus. FIG. It is a flowchart which shows 1st switching control. It is a flowchart which shows 2nd switching control. It is the schematic which shows the flow-path structure of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer main body, 2 Cartridge, 2a-2h Cartridge, 3 Carriage, 4 Supply tube, 4a-4d Supply tube, 5 Pressure adjustment part, 5a-5d Pressure adjustment part, 6 Carriage motor, 7 Timing belt, 8 Scanning guide Member, 9 paper feeding member, 10 cap member, 11 suction pump, 12 waste liquid tank, 13 tube, 14 wiping member, 15 cartridge tube, 15a to 15h cartridge tube, 16 switching means, 16a to 16d switching means, 20 atmospheric release means 21 First opening / closing means 22 Second opening / closing means 25a to 25d Nozzle row, 26 Cleaning cartridge 27 Cleaning liquid tank 28 Cleaning waste liquid tank 29 Cleaning pump 30 Recording head, 31 Ink supply needle, 31a Ink introduction hole, 32 Filter, 33 Filter case, 34 Head body, 35 Ink communication flow path, 37 Self-sealing valve, 43 Ink switching control means 44 Carriage control means 45 Lifting device 46 Ink switching command switch 47 Print control means 48 Wiping control means 49 Valve control means 50 Pump Drive means 51 Head drive means 200 Valve packing holder, 201 Switching valve housing, 202 Entrance / exit plate, 210 Valve packing, 220 Spring, 230 240 250 260 Open, 280 Flow path, 290 Tail

Claims (14)

An ejection head for ejecting liquid from a nozzle to an ejection target; suction means for applying a negative pressure to the nozzle of the ejection head to suck and discharge the liquid; and for supplying liquid to the ejection head An opening / closing means for opening and closing a plurality of supply channels, and an atmosphere opening means for releasing the inside of the ejection head to the atmosphere at the time of suction by the suction means,
When the liquid supplied to the ejection head is switched from the first liquid to the second liquid by the opening / closing operation of the first opening / closing means and the second opening / closing means,
With the first opening / closing means closed and the second opening / closing means opened, the first liquid filled in the ejection head is diluted with the second liquid by suction with the suction means,
With the second opening / closing means closed and the atmosphere opening means opened, the liquid in the ejection head is discharged by suction with the suction means,
A liquid ejecting apparatus that performs first switching control for filling a second liquid into an ejecting head by sucking with an aspirating means in a state in which the air opening means is closed and the second opening / closing means is opened. When the liquid supplied to the ejection head is switched from the second liquid to the first liquid by the opening / closing operation of the first opening / closing means and the second opening / closing means,
With the second opening / closing means closed and the atmosphere opening means opened, the liquid in the ejection head is discharged by suction with the suction means,
2. The liquid ejecting apparatus according to claim 1, wherein the second switching control is performed to fill the first liquid in the ejection head by suction with the suction means in a state where the air opening means is closed and the first opening / closing means is opened.   The liquid ejecting apparatus according to claim 2, further comprising selection execution means for selecting and executing the first switching control and the second switching control.   The information related to the type and combination of the first liquid and / or the second liquid is acquired, and when the first liquid is diluted with the second liquid, control is performed so as to set an appropriate suction time according to the acquired information. The liquid ejecting apparatus according to any one of 1 to 3.   The environmental temperature is detected by the environmental temperature detection means, and when the first liquid is diluted with the second liquid, the suction time is controlled to be longer as the detected environmental temperature is higher. The liquid ejecting apparatus described.   The liquid ejecting apparatus according to any one of claims 1 to 5, wherein the first liquid and the second liquid are a combination of liquids in which the first liquid is more easily bubbled than the second liquid.   The liquid ejecting apparatus according to claim 1, wherein the second liquid is a cleaning liquid that cleans the inside of the ejecting head.   The liquid ejecting apparatus according to claim 1, wherein the first liquid and the second liquid are a combination of inks in which the first liquid is relatively darker than the second liquid. A liquid switching method of a liquid ejecting apparatus including an ejecting head for ejecting liquid from a nozzle to an ejecting object,
When switching the liquid supplied to the ejection head from the first liquid to the second liquid,
In the state where the supply of the first liquid to the ejection head is shut off and the state is switched to the state where the second liquid is supplied, a negative pressure is applied to the nozzle of the ejection head to suck the first liquid filled in the ejection head. Dilute one liquid with a second liquid,
In a state where the supply of the second liquid is shut off and the inside of the ejection head is opened to the atmosphere, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
In a state in which the air release state is stopped and the state in which the second liquid is supplied to the ejection head is switched, a negative pressure is applied to the nozzle of the ejection head to suck the second liquid into the ejection head. A liquid switching method for a liquid ejecting apparatus, wherein: When switching the liquid supplied to the ejection head from the second liquid to the first liquid,
In a state where the supply of the second liquid is shut off and the inside of the ejection head is opened to the atmosphere, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
In a state where the air release state is stopped and the state in which the first liquid is supplied to the ejection head is switched, a negative pressure is applied to the nozzle of the ejection head to suck the first liquid into the ejection head. The liquid switching method for a liquid ejecting apparatus according to claim 9, wherein the liquid is filled. An ejection head for ejecting liquid from a nozzle to an ejection target; an opening / closing means for opening and closing a plurality of supply channels for supplying liquid to the ejection head; and the ejection at the time of suction by the suction means A liquid switching method of a liquid ejecting apparatus including an air release means for releasing the inside of a head to the atmosphere,
When the liquid supplied to the ejection head is switched from the first liquid to the second liquid by the opening / closing operation of the first opening / closing means and the second opening / closing means,
With the first opening / closing means closed and the second opening / closing means opened, the first liquid filled in the ejection head is diluted with the second liquid by applying a negative pressure to the nozzle of the ejection head and sucking it. And
With the second opening / closing means closed and the air release means opened, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
A liquid jet characterized in that the second liquid is filled in the jet head by applying a negative pressure to the nozzle of the jet head and sucking in a state where the air opening means is closed and the second open / close means is opened. Device liquid switching method. When the liquid supplied to the ejection head is switched from the second liquid to the first liquid by the opening / closing operation of the first opening / closing means and the second opening / closing means,
With the second opening / closing means closed and the air release means opened, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
The liquid ejecting according to claim 11, wherein the first liquid is filled in the ejecting head by applying a negative pressure to the nozzle of the ejecting head and sucking in a state where the air opening means is closed and the first opening / closing means is opened. Device liquid switching method. A method of cleaning an ejection head in a liquid ejection apparatus including an ejection head that ejects liquid from a nozzle onto an ejection object,
When cleaning the inside of the jet head by discharging the liquid filled in the jet head,
The liquid filled in the ejection head is diluted with the cleaning liquid by applying a negative pressure to the nozzle of the ejection head and sucking in the state where the liquid supply to the ejection head is shut off and the cleaning liquid is supplied. And
In a state where the supply of the cleaning liquid is shut off and the inside of the jet head is opened to the atmosphere, the liquid in the jet head is discharged by applying a negative pressure to the nozzle of the jet head and sucking it,
The cleaning liquid is introduced into the ejection head by applying a negative pressure to the nozzle of the ejection head and sucking the nozzle while the air release state is stopped and the cleaning liquid is supplied to the ejection head. A method of cleaning an ejection head in a liquid ejecting apparatus. An ejection head for ejecting liquid from a nozzle to an ejection target; an opening / closing means for opening and closing a plurality of supply channels for supplying liquid to the ejection head; and the ejection at the time of suction by the suction means A cleaning method for an ejection head in a liquid ejection apparatus including an air release means for releasing the inside of the head to the atmosphere,
When cleaning the inside of the jet head by discharging the liquid filled in the jet head,
With the first opening / closing means closed and the second opening / closing means opened, the liquid filled in the ejection head is diluted with a cleaning liquid by applying a negative pressure to the nozzles of the ejection head and sucking them.
With the second opening / closing means closed and the air release means opened, the liquid in the ejection head is discharged by applying a negative pressure to the nozzle of the ejection head and sucking it,
In the liquid ejecting apparatus, the cleaning liquid is introduced into the ejecting head by applying a negative pressure to the nozzle of the ejecting head and sucking the air in a state where the atmosphere opening means is closed and the second opening / closing means is opened. Cleaning method of the jet head.

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