JP2007203562A - Liquid ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejector in which the lifetime of a pump is ensured and waste liquid does not leak to the pressurization system by performing the pressurization operation of a liquid cartridge and the suction operation of an ejection head using the same pump thereby shortening the operating time of the pump. <P>SOLUTION: The liquid ejector comprises a recording head 30 which ejects ink toward a recording sheet, an ink cartridge 9 containing an ink pack 24 filled with ink being supplied to the recording head 30, a pump 27 for sucking the internal space of a cap member 11a capping the nozzle surface of the recording head 30, a passage 13 connecting the discharge side of the pump 27 to the ink cartridge so that the pump 27 functions as a pressurization means in the ink cartridge 9, and a switching valve 14 for introducing waste liquid discharged from the pump 27 through the suction operation into a waste liquid collection tank 22, and introducing pressurization air discharged from the pump 27 in order to pressurize the ink cartridge 9 toward the downstream side of the connection passage 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus that is used as an ink jet recording apparatus that forms dots on a recording medium by ejecting ink droplets from nozzles corresponding to print data, and more specifically, pressurization that applies air pressure to a liquid cartridge. The present invention relates to a liquid ejecting apparatus in which an operation and a suction operation for sucking and discharging liquid from an ejecting head are performed by the same pump.

  As a liquid ejecting apparatus that ejects liquid onto a target, an ink jet recording apparatus that ejects ink onto a recording medium is known. Such an ink jet recording apparatus is generally mounted on a carriage and moved in the width direction of the recording paper, and the recording paper moves relatively in a direction perpendicular to the moving direction of the recording head. Paper feeding means is provided, and printing is performed on the recording paper by ejecting ink droplets from the recording head based on the print data.

  On the other hand, in this type of recording apparatus provided for office use or business use, for example, a large-capacity ink cartridge needs to be provided in order to cope with a relatively large amount of printing. For example, a recording apparatus of a type that is loaded in a cartridge holder disposed on the apparatus main body side is provided. A sub tank is disposed on the carriage on which the recording head is mounted, ink is supplied from each ink cartridge to each sub tank via an ink supply tube, and ink is supplied from each sub tank to the recording head. Is configured to supply.

  In recent years, there has been a demand for a large recording apparatus having a long carriage scanning distance capable of printing on a larger paper surface. In such a recording apparatus, in order to improve the throughput, the number of nozzles is increasingly increased in the recording head. Furthermore, in order to improve the throughput, it is possible to replenish ink sequentially from the ink cartridge to each sub tank mounted on the carriage while printing is performed, so that the ink is stabilized from each sub tank to the recording head. And a recording apparatus that can be supplied.

  In such a recording apparatus, it is necessary to connect an ink supply tube corresponding to each ink from the ink cartridge to the sub tank, and the scanning distance of the carriage is inevitably increased, so that the drawing distance of the tube is inevitably increased. To do. In addition, as described above, since the recording head has a large number of nozzles, the amount of ink consumed is large, and the dynamic pressure (pressure loss) of ink in each ink supply tube connected from the ink cartridge to the sub tank is high. Increasingly, there is a technical problem that the amount of ink replenished to the sub tank is insufficient.

  As one means for solving such a problem, for example, by applying air pressure to the ink cartridge side and generating a forced ink flow from the ink cartridge to the sub tank by air pressure, it is necessary and sufficient for the sub tank. A configuration for replenishing fresh ink is employed.

  As an ink cartridge used in the recording apparatus having the above-described configuration, an ink pack formed of a flexible material in which ink is encapsulated is molded so that the case constituting the outer shell is airtight. The configured configuration can be suitably employed. The ink pack in the ink cartridge having such a configuration acts so that the ink is pushed out by the pressurized air applied in the case, and the ink is sent to the recording head mounted on the carriage.

  On the other hand, in an ink jet recording apparatus, in order to eliminate defective ink ejection, forcibly ejected thickened ink or the like from the recording head, or forcibly ejects bubbles remaining in the recording head, resulting in defective ejection. A so-called cleaning operation is appropriately performed in order to prevent the occurrence of the above. In this cleaning, the nozzle forming surface of the recording head is capped with a capping member, and a negative pressure is applied to the internal space of the capping member with a suction pump, whereby ink is forcibly sucked and discharged from the nozzle opening. is there.

  In the conventional ink jet recording apparatus as described above, at least two pumps that perform the pressurizing operation and pumps that collect the waste ink discharged from the recording head are necessary to perform ink supply and recovery operations. is there.

Therefore, an ink jet recording in which the pressurizing operation for pressurizing and deforming the ink bag to push the ink to the recording head and the ink collecting operation for collecting the waste ink pushed away from the recording head are performed by the same pump. An apparatus has been proposed (for example, Patent Document 1 below).
JP 2001-162838 A

  However, the recording apparatus of Patent Document 1 uses a pump for both suction and pressurization, and the pump must always be driven to rotate at the time of pressurization. In particular, as a pump of an ink jet recording apparatus, a type using a volume change using an elastic member such as rubber, such as a tube pump, is often used, and since it is severe in terms of life, it is always used at the time of pressurization. Pump consumption due to rotation is a problem. In addition, since the waste liquid sucked from the recording head goes to the pressurization system of the cartridge, the path of the waste liquid becomes complicated, the reliability against waste liquid leakage is reduced, and countermeasures are required. A new problem arises that life prediction becomes difficult.

  The present invention has been made in view of such circumstances. The pressurization operation for applying air pressure to the liquid cartridge and the suction operation for sucking and discharging the liquid from the ejection head are performed by the same pump, and the operation time of the pump is greatly increased. An object of the present invention is to provide a liquid ejecting apparatus that ensures the life of the pump by shortening the length of the liquid and does not turn the waste liquid into the pressurizing system.

  In order to achieve the above object, a liquid ejecting apparatus of the present invention includes a liquid containing an ejecting head that ejects liquid toward an ejecting target and a flexible liquid pack in which the liquid supplied to the ejecting head is sealed. A cartridge, a pump that sucks an internal space of a cap member that caps the nozzle surface of the ejection head, and a connection path that connects a discharge side of the pump to the liquid cartridge so that the pump functions as a pressurizing unit in the liquid cartridge. A switching valve for introducing the waste liquid discharged from the pump by the suction operation into the waste liquid collecting means and introducing the pressurized air discharged from the pump toward the downstream side of the connection path in order to pressurize the liquid cartridge; The main point is that

  According to the liquid ejecting apparatus of the present invention, the pressurizing operation for applying air pressure to the liquid cartridge and the suction operation for sucking and discharging the liquid from the ejecting head are performed using the same pump. In addition to reducing costs, the installation space for the pump can be reduced, and the device can be downsized. Further, a switching valve for introducing the waste liquid discharged from the pump by the suction operation into the waste liquid collecting means and introducing the pressurized air discharged from the pump toward the downstream side of the connection path in order to pressurize the liquid cartridge Since the waste liquid sucked from the ejection head does not go to the pressurization system of the liquid cartridge but is introduced only to the waste liquid recovery means, the path of the waste liquid is not complicated, and the waste liquid leaks. In addition to ensuring reliability, it is possible to reliably predict the life of waste liquid tanks.

  In the present invention, it further comprises a pressure storage tank provided in the connection path for storing pressurized air for pressurizing the liquid cartridge, and the switching valve introduces waste liquid discharged from the pump during the suction into the waste liquid collecting means. However, when switching to introduce the pressurized air discharged from the pump when the pressure is stored in the pressure tank into the pressure tank, it is only necessary to operate the pump when suctioning the injection head and when pressure is stored in the pressure tank. Therefore, the pump operating time can be greatly shortened to ensure the pump life.

  In the present invention, there is provided a pressure regulating valve that allows the liquid cartridge to be pressurized from the pressure storage tank by opening and closing the communication state of the pressure storage tank and the liquid cartridge, regardless of the operating state of the pump. Since the pressurization of the liquid cartridge can be performed without operating the pump, the operating time of the pump can be greatly shortened to ensure the pump life. In addition, since the liquid cartridge can be pressurized only by opening and closing the pressure regulating valve without operating the pump, the liquid cartridge can be pressurized when necessary regardless of whether the pump is operated or not. The operating time can be greatly shortened to ensure the pump life.

  In the present invention, a first pressure sensor for detecting the pressure of the pressure storage tank is provided, and when the pressure detected by the first pressure sensor is lower than a predetermined pressure, the pressure adjusting valve is closed and the switching valve is set to the pressure storage tank side. When storing the pressure storage tank by switching, it is only necessary to operate the pump when the pressure in the pressure storage tank is required, and the pump operating time can be reliably shortened to ensure the pump life.

  A second pressure sensor for detecting the pressure of the liquid cartridge; when the pressure detected by the second pressure sensor is lower than a predetermined pressure and the pressure adjustment valve is opened to pressurize the liquid cartridge, Since the liquid cartridge can be pressurized without operating the pump when pressure is required, the operating time of the pump can be reliably shortened and the pump life can be ensured.

  In the present invention, the pressure operation of the liquid cartridge is performed at least one of when the power is turned on, when the liquid injection operation to the injection target is started, and when the suction operation is started. When the pressure storage operation is performed when the pressure drops, the pump can be operated when the storage tank needs to store pressure during the pressurizing operation of the liquid cartridge, and the pump operation time is ensured. The pump life can be ensured by shortening to

  In the present invention, when the pressure storage operation to the pressure storage tank is started, when the injection operation to the injection target is being performed, when the pressure storage operation is performed after the injection operation is finished, the injection operation is being performed. Since the liquid may be accumulated in the cap member, the ink can be prevented from being introduced into the pressure storage tank during the pressure storage operation.

  In the present invention, when the pressure storage operation to the pressure storage tank is started, when the cleaning operation is being performed, when the pressure storage operation is executed after the cleaning operation is completed, the liquid is removed by the cap member during the cleaning operation. Therefore, it is possible to prevent the ink from being introduced into the pressure storage tank during the pressure storage operation.

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

  Hereinafter, an embodiment of an ink jet recording apparatus as a liquid ejecting apparatus embodying the present invention will be described.

  FIG. 1 is a plan view showing the basic configuration of the recording apparatus. Reference numeral 1 denotes a carriage 1, which is guided by a scanning guide member 4 through a timing belt 3 driven by a carriage motor 2, in the longitudinal direction of the paper feeding member 5, that is, a recording paper as an ejection target. It is configured to reciprocate in the main scanning direction which is the width direction. Although not shown in the drawing, the carriage 1 is mounted with an ink jet recording head 30 described later on the surface facing the paper feeding member 5.

  The carriage 1 is equipped with pressure adjusting units 7 a to 7 d for reducing and adjusting the pressure of the ink when supplying ink to the recording head 30. In this embodiment, four pressure adjusting portions 7a to 7d are provided corresponding to each ink in order to temporarily store each ink therein. The pressure adjusting units 7a to 7d are respectively connected to the ink cartridges 9a to 9d mounted on the cartridge holder 8 serving as a cartridge mounting unit disposed in the apparatus main body via the flexible ink supply tube 10. , Black, yellow, magenta and cyan inks are supplied.

  Ink cartridges 9a to 9d as main tanks, that is, liquid cartridges, are formed so that the outer configuration thereof is flat. In the cartridge holder 8, so-called vertical placement is performed so that the flat surfaces face each other in the vertical direction. It is installed in a state.

  On the other hand, a capping unit 11 capable of sealing the nozzle forming surface of the recording head 30 is disposed in a non-printing area (home position) on the movement path of the carriage 1, and further, an upper surface of the capping unit 11. The cap member 11a formed of a flexible material such as rubber that can seal the nozzle forming surface of the recording head 30 is disposed. When the carriage 1 moves to the home position, the cap member 11a can cap the nozzle forming surface of the recording head 30.

  The cap member 11 a functions as a lid that seals the nozzle formation surface of the recording head 30 and prevents the nozzle opening 25 from drying during the rest period of the recording apparatus. Further, one end of a tube in a pump 27 (tube pump), which will be described later, is connected to the cap member 11a, and a negative pressure by the pump 27 is applied to the recording head 30 so that ink is sucked and discharged from the recording head 30. Is configured to run. A wiping member 12 made of an elastic material such as rubber is disposed adjacent to the printing area side of the capping unit 11 so that the nozzle forming surface of the recording head 30 can be wiped and cleaned as necessary. It is configured.

  2 and 3 show a recording head 30 mounted on the carriage 1 and ejecting ink as a liquid, and pressure adjusting units 7a to 7d mounted on the recording head 30. FIG.

  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 7a to 7d is introduced into the ink supply needle 31 through the ink introduction hole 31a, and the ink communication is performed. The ink is supplied to the head main body 34 through the flow path 35 and ejected from each nozzle opening 25. The nozzle opening 25 forms four nozzle rows corresponding to the four pressure adjusting portions 7a to 7d, that is, the four ink cartridges 9a to 9d, and ink corresponding to the ink cartridges 9a to 9d is supplied from each nozzle row. Spray.

  The ink supply needles 31 are arranged so as to be arranged at a predetermined interval according to the arrangement state of the pressure adjusting units 7a to 7d. 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 7. By the operation of the self-sealing valve 37, the pressure of the ink sent from the ink cartridges 9a to 9d through the ink supply tube 10 and the ink supply needle 31 to the recording head 30 is reduced and adjusted. For example, when pressure fluctuations occur in the ink in the ink supply tube 10 as the carriage 1 is accelerated and decelerated, the ejection of ink droplets becomes unstable, so the pressure adjustment units 7a to 7d suppress ink pressure fluctuations.

  FIG. 4 schematically shows configurations of an ink supply path from the ink cartridge 9 to the recording head 30 of the recording apparatus, a suction path of the pump 27, and a pressure path of the ink cartridge 9.

  The ink cartridge 9 has a cartridge case 20 as an outer case formed in an airtight state, and an ink pack 24 as a liquid pack formed of a flexible material and filled with ink is accommodated therein. ing. A space formed by the cartridge case 20 and the ink pack 24 constitutes a pressure chamber 23, and pressurized air is supplied into the pressure chamber 23.

  With this configuration, the ink packs 24 housed in the ink cartridges 9a to 9d are pressurized by the pressurized air, respectively, and a predetermined pressure is applied from the ink cartridges 9a to 9d to the pressure adjusting units 7a to 7d. Ink flow is generated.

  The ink pressurized in the ink cartridges 9a to 9d is supplied to the pressure adjusting units 7a to 7d (FIG. 4) mounted on the carriage 1 through the ink supply valves 26 and the ink supply tubes 10, respectively. In FIG. 2, the reference numeral 7 is representatively shown, and the following description may be simply given as the reference numeral 7).

  Then, ink is supplied from each pressure adjusting unit 7 to the recording head 30, and nozzle openings 25 formed on the nozzle formation surface of the recording head 30 based on print data supplied to an actuator (not shown) of the recording head 30. Thus, the ink droplets are ejected toward the recording paper as the ejection target.

  The nozzle forming surface of the recording head 30 is capped with the cap member 11a described above, and the ink inside the recording head 30 is sucked and discharged by a pump that sucks the internal space of the cap member 11a.

  In this example, a tube pump is used as the pump 27. A flexible tube communicating with the inside of the cap member 11a is arranged in an arc shape, and a pressing member rolls around the inner periphery of the tube. Are sequentially crushed to create a negative pressure inside the cap member 11a and suck the ink of the recording head 30.

  A connection path 13 for connecting the discharge side of the pump 27 to the ink cartridge 9 is provided so that the pump 27 functions as a pressurizing means in the ink cartridge 9. Further, in the middle of the connection path 13, in order to pressurize the ink cartridge 9 by introducing the waste liquid discharged from the pump 27 by the suction operation of the recording head 30 by the pump 27 into the waste liquid recovery tank 22 as waste liquid recovery means. A switching valve 14 is provided for sending pressurized air discharged from the pump 27 toward the downstream side of the connection path 13.

  That is, the switching valve 14 switches whether the fluid discharged from the pump 27 flows to the waste liquid recovery tank 22 side or to the ink cartridge 9 side. When the cap member 11 a caps the nozzle forming surface of the recording head 30 and the pump 27 performs the suction operation of the recording head 30, the switching valve 14 is switched to the waste liquid recovery tank 22 side, and the ink discharged from the recording head 30 is discharged. It collects in the waste liquid collection tank 22. When the cap member 11a is removed from the nozzle forming surface of the recording head 30 and the pump 27 sends pressurized air to the downstream side, the switching valve 14 is switched to the ink cartridge 9 side to send pressurized air.

  A pressure storage tank 21 for storing pressurized air for pressurizing the ink cartridge 9 is provided on the downstream side of the switching valve 14 in the connection path 13, that is, on the ink cartridge 9 side. Therefore, the switching valve 14 introduces the ink discharged from the pump 27 during the suction into the waste liquid recovery tank 22, and stores the pressurized air discharged from the pump 27 when the pressure storage tank 21 is stored up to a predetermined pressure. It switches so that it may introduce into pressure tank 21.

  Further, the communication path between the pressure storage tank 21 and the ink cartridge 9 is opened and closed downstream of the pressure storage tank 21 in the connection path 13, that is, the ink cartridge 9 side, regardless of the operating state of the pump 27. A pressure regulating valve 15 that enables pressurization of the ink cartridge 9 from the pressure storage tank 21 is provided. That is, if the pressure storage tank 21 is at a pressure higher than a predetermined pressurizable pressure, the ink cartridge 9 can be pressurized by simply opening the pressure adjustment valve 15 without operating the pump 27.

  A first pressure sensor 16 for detecting the pressure in the pressure storage tank 21 is provided between the pressure storage tank 21 and the pressure regulating valve 15 in the connection path 13. When the pressure detected by the first pressure sensor 16 is lower than the predetermined pressure, that is, the pressurizable pressure for pressurizing the ink cartridge 9, the pressure adjustment valve 15 is closed and the switching valve 14 is switched to the pressure storage tank 21 side. Thus, a pressure accumulating operation for accumulating the pressure accumulating tank 21 is executed.

  Further, a second pressure sensor 17 for detecting the pressure of the ink cartridge 9 is provided between the pressure adjustment valve 15 of the connection path 13 and the ink cartridge 9. When the pressure detected by the second pressure sensor 17 is lower than a predetermined pressure, that is, a supplyable pressure for supplying ink to the recording head 30, the pressure adjustment valve 15 is opened to pressurize the ink cartridge 9. The action is to be executed. In this pressurizing operation, the switching valve 14 may be switched to the waste liquid recovery tank 22 side, or the switching valve 14 may be switched to the pressure storage tank 21 side.

  The pressurizing operation is performed at least one of a liquid ejecting operation to the ejecting object, that is, a printing operation, and a sucking operation when the recording apparatus is turned on. The pressure accumulation operation can be executed when the pressure of 21 decreases.

  FIG. 5 is a block diagram showing an example of the system configuration of the recording apparatus.

  The printing control means 46, carriage control means 47, pressure control means 50, head driving means 48, cleaning control means 49, and paper feed control means 52 described here function as control means in the present invention.

  In the figure, a host computer 44 has a built-in printer driver 45, and the size of the recording paper, monochrome / color printing selection, and recording mode are input by an input device (not shown) on the utility of the printer driver 45. Selection, font data, and print commands can be input.

  In response to the input of the print command, the printer driver 45 sends print data that is liquid ejection data to the print control means 46. Further, the print control unit 46 generates bitmap data based on the print data, generates a drive signal by the head drive unit 48 and inputs the drive signal to the piezoelectric vibrator that is an actuator of the recording head 30, and the ink droplets from the recording head 30. Is to be discharged. At this time, the paper feed control means 52 controls the movement of the recording paper in the sub-scanning direction by controlling a paper feed motor (not shown) according to an instruction from the print control means 46. In addition, the carriage control unit 47 controls the carriage motor 2 that is a pulse motor in response to an instruction from the print control unit 46 to control the carriage 1 to reciprocate in the main scanning direction.

  The head drive unit 48 functions as a drive unit, and receives a flushing command signal from a flushing control unit (not shown) in addition to a drive signal based on print data, and outputs a drive signal for flushing to the recording head 30. To do. By this flushing operation, ink that is irrelevant to printing is ejected from the nozzles to the cap member 11a serving as a flushing box, thereby discharging the thickened ink near the nozzles and restoring the ejection characteristics of the recording head 30.

  Here, the mechanism by which the discharge capacity of the nozzles is reduced will be described. During the printing, the nozzle surface of the recording head 30 is released from the cap member 11a, and the carriage 1 is moved back and forth. If the ink is not ejected in such a state, the solvent evaporates from the ink present in the nozzle opening, the viscosity gradually increases, and the ejection capacity decreases. Further, nozzles that frequently eject ink droplets during printing are supplied with new ink one after another, and clogging does not occur so much, but nozzles that have few opportunities to eject ink droplets tend to clog. Therefore, as the nozzle discharge amount is small and the idle time is long, the thickening proceeds, and the degree thereof varies from nozzle to nozzle.

  In this example, the case has been described in which the liquid ejected by the ejection head is ink, and the ejection capability of the nozzle is reduced due to the increased viscosity of the ink. However, the mechanism by which the ejection characteristics are degraded varies depending on the type of liquid to be ejected. In some cases, the present invention is applicable not only to ink but also to an apparatus that ejects various liquids as long as the lowered nozzle ejection characteristics can be recovered by liquid ejection.

  The carriage control unit 47 performs movement control for reciprocating the carriage 1 in the main scanning direction during the printing operation, and also moves the carriage 1 to a flushing position other than the printing area at a predetermined flushing timing, thereby moving the recording head 30 to the cap member. Movement control is performed to move to a position where the flushing operation is performed facing the 11a.

  The carriage control means 47 performs movement control for moving the recording head 30 to the position of the cap member 11a when the apparatus is turned off or when a suction operation is performed.

  The above-described suction operation of the recording head 30 is an initial filling operation in which, when the printer main body is used for the first time, when the cartridge 9 is mounted for the first time, the ink is first filled in the flow path of the recording head 30 and the pressure adjusting unit 7. It is executed at the time of. Also, when the ink cartridge 9 is replaced or when the used ink cartridge 9 is once removed and reloaded, air is mixed into the flow path of the recording head 30 along with the replacement or reloading, and normal ejection is performed. This is executed to forcibly suck out the mixed bubbles from the recording head 30 and remove them.

  In the above suction operation, when the printer main body is left without being used, even if the nozzle forming surface is sealed with the cap member 11a, the leaving time measured by a not shown timer (not shown) When the power is turned on for a long time, the solvent gradually evaporates from the ink present in the nozzle openings, increasing its viscosity and reducing its discharge capacity. At the time of ON, suction in the cleaning mode is executed by the control by the cleaning control means 49. In addition, if the printing operation is continued, bubbles remaining in the flow path may gradually accumulate in the upstream part of the internal filter, so cleaning control is performed for cleaning that periodically removes the bubbles by forced suction. The suction by the cleaning mode may be executed under the control of the means 49.

  In each of the above suction operations, the suction conditions may vary depending on the situation, such as the initial filling, the replacement of the ink cartridge 9, and the suction at the time of cleaning. Therefore, the rotation speed and operating time of the pump 27 are controlled by the cleaning control means 49. By controlling the above, suction in a predetermined suction mode is executed.

  The suction operation is controlled by the cleaning control means 49 as follows. That is, the carriage 1 is moved to a position where the carriage 1 faces the cap member 11a, and the cap member 11a is raised by, for example, a cam mechanism by an operation of a maintenance motor (not shown) to seal the nozzle forming surface of the recording head 30 with the cap member 11a. To do. Further, the switching valve 14 is switched to the waste liquid recovery tank 22 side, and the inside of the cap member 11a is sucked by the action of the pump 27 driven by the maintenance motor to forcibly discharge ink and the like from the nozzles. The sucked ink is collected in the waste liquid collection tank 22 through the switching valve 14.

  After performing suction for a predetermined time, the pump 27 is driven in a state where the cap member 11a is opened to the atmosphere by a valve mechanism (not shown), and empty suction is performed to discharge ink remaining in the space in the cap member 11a. Thereafter, when the cap member 11a is lowered, the ink is adhered to the nozzle forming surface in this state, and therefore the wiping member 12 is raised to a position where the tip of the wiping member 12 can contact the nozzle forming surface by driving the maintenance motor. After that, by controlling the movement of the carriage 1, the ink attached to the nozzle forming surface is wiped off by the wiping member 12.

  On the other hand, when the pressure in the pressure storage tank 21 detected by the first pressure sensor 16 is lower than the pressurizable pressure for pressurizing the ink cartridge 9, the pressure storage operation to the pressure storage tank 21 is performed. By removing the recording head 30 from the nozzle forming surface, closing the pressure adjusting valve 15 and switching the switching valve 14 to the pressure storage tank 21 side, and driving the pump 27, only air is sucked from the cap member 11a and the pressure is stored. It is sent to the tank 21 to store pressure. The pump 27 is stopped when the pressure in the pressure storage tank 21 detected by the first pressure sensor 16 exceeds the pressurizable pressure.

  The pressurization operation from the pressure storage tank 21 to the ink cartridge 9 is performed when the pressure of the ink cartridge 9 detected by the second pressure sensor 17 is lower than the supplyable pressure for supplying ink to the recording head 30. The pressure adjustment valve 15 is opened, the switching valve 14 is switched to the pressure tank 21 side, and the pressurized air in the pressure tank 21 is introduced into the ink cartridge 9 and pressurized. When the pressure of the ink cartridge 9 detected by the second pressure sensor 17 exceeds the supplyable pressure, the pressure adjustment valve 15 is closed.

  Reading of the pressure value detected by the first pressure sensor 16 in the pressure accumulating operation, and operations of the pump 27, the capping unit 11, the switching valve 14, and the pressure adjusting valve 15 are controlled by the pressurizing control unit 50. Further, the reading of the pressure value detected by the second pressure sensor 17 in the pressurizing operation and the operations of the switching valve 14 and the pressure adjusting valve 15 are controlled by the pressurizing control means 50.

  FIG. 6 is a flowchart showing an example of a processing operation when the ink cartridge 9 is pressurized when the power is turned on in the recording apparatus.

  First, in the initial state when the power is turned on, the switching valve 14 is set to close the pressure storage tank 21 side, the waste liquid recovery tank 22 side is set to open, and the pressure adjustment valve 15 is closed. Then, the pressure value detected by the second pressure sensor 17 is read to determine whether the pressure in the ink cartridge 9 is higher or lower than a predetermined threshold (S1). In S1, if the pressure value in the ink cartridge 9 is higher than the predetermined threshold value, this sequence is terminated. If the pressure value in the ink cartridge 9 is lower than the predetermined threshold value, the process proceeds to S2, and the ink described later The pressurizing operation of the cartridge 9 is executed.

  FIG. 7 is a flowchart showing details of the pressurizing operation of the ink cartridge 9, and FIG. 8 is a flowchart showing details of the pressure storing operation of the pressure storage tank 21. The pressurizing operation and the pressure accumulating operation are executed in S2.

  7 starts when the pressure in the ink cartridge 9 detected by the second pressure sensor 17 is lower than a predetermined threshold (S1 in FIG. 6, S42 and S45 in FIG. 9). First, the pressure value detected by the first pressure sensor 16 is read to determine whether the pressure in the pressure storage tank 21 is higher or lower than a predetermined threshold (S11). In S11, when the pressure value in the pressure storage tank 21 is higher than the predetermined threshold value, the process proceeds to S13 and subsequent steps to pressurize the ink cartridge 9, and the pressure value in the pressure storage tank 21 is lower than the predetermined threshold value. Advances to S12 and executes a pressure accumulation operation.

  If the pressure value in the pressure storage tank 21 is higher than the predetermined threshold value in S11, the pressure adjustment valve 15 is opened and the pressurized air in the pressure storage tank 21 is introduced into the ink cartridge 9 to pressurize the ink cartridge 9. Is started (S13). Next, in S14, the pressure value in the ink cartridge 9 is detected by the second pressure sensor 17, and as long as the pressure value in the ink cartridge 9 is lower than a predetermined threshold, the pressurization is continued as it is. When the pressure value becomes higher than the predetermined threshold value, the pressure regulating valve 15 is closed in S15, and this sequence is finished.

  On the other hand, when the pressure value in the pressure storage tank 21 is lower than the predetermined threshold value in S11, a pressure storage operation described later is executed.

  The pressure accumulation operation in FIG. 8 is started when the pressure in the pressure accumulation tank 21 detected by the first pressure sensor 16 is lower than a predetermined threshold (S11 in FIG. 7). First, printing is performed in S21. Whether printing is in progress or not is determined. If printing is in progress, the process waits for printing to end. If printing has ended, the process proceeds to S22. Since the flushing operation and the cleaning operation are periodically performed during printing, ink may be accumulated in the cap member 11a. If the pressure accumulation operation is performed as it is, the ink is introduced into the pressure accumulation tank 21. Because there is a fear.

  In S22, it is determined whether or not a cleaning operation is being performed. If the cleaning operation is being performed, the end of the cleaning operation is awaited. If the cleaning operation has been completed, the process proceeds to S23. This is because, during cleaning, the cap member 11 a caps the recording head 30 to perform suction, and ink is introduced into the pressure storage tank 21.

  If printing and cleaning have been completed, the pressure regulating valve 15 is closed in S23, and then in S24, the switching valve 14 is switched to the pressure storage tank 21 side and the waste liquid recovery tank 22 side is closed. Next, the cap member 11a is released from the cap state of the recording head 30 in S25, and the pump 27 is operated in S26. As a result, the inside of the cap member 11a opened in the air is sucked, so that only air is introduced into the pressure storage tank 21 and the pressurized air is stored.

  Next, in S27, the pressure value in the storage tank 21 is detected by the first pressure sensor 16, and if the pressure value does not reach the predetermined threshold value, the suction is continued, and the pressure value in the storage tank 21 reaches the predetermined value. When the threshold value is reached, the process proceeds to S28, and the switching valve 14 is switched to close the pressure storage tank 21 side and open the waste liquid recovery tank 22 side. Next, in step S29, the cap member 11a is put into the cap state of the recording head 30, and this sequence is completed.

  FIG. 9 is a flowchart illustrating an example of a processing operation when the pressure operation of the ink cartridge 9 is performed at the start of the printing operation in the recording apparatus.

  First, in the initial state at the start of printing, the switching valve 14 is set to close the pressure storage tank 21 side, the waste liquid recovery tank 22 side is set to open, and the pressure adjustment valve 15 is closed. When the print data is received in S41, it is determined whether the pressure value in the ink cartridge 9 detected by the second pressure sensor 17 is higher or lower than a predetermined threshold (S42). When the pressure value in the ink cartridge 9 is lower than the predetermined threshold value in S42, the process proceeds to S43, and the pressurizing operation and the pressure accumulating operation described in FIGS. 7 and 8 are executed.

  On the other hand, if the pressure value in the ink cartridge 9 is higher than the predetermined threshold value in S42, the printing operation is started (S44). Even during the printing operation, it is determined whether the pressure value in the ink cartridge 9 detected by the second pressure sensor 17 is higher or lower than a predetermined threshold value (S45). When the pressure value in the ink cartridge 9 becomes lower than the predetermined threshold value, the process proceeds to S46, and the pressurizing operation and the pressure accumulating operation described with reference to FIGS. 7 and 8 are executed. In this case, when the pressure accumulating operation is performed, the printing is temporarily interrupted, and after the cap member 11a is removed from the nozzle surface and the switching valve 14 is switched to the waste liquid recovery tank 22 side, idle suction for operating the pump 27 is performed. It is preferable to start the pressure accumulating operation. By doing so, the ink that has been discharged into the cap member 11a by flushing or the like can be stored after the ink is recovered to the waste liquid recovery tank 22 by idle suction, so that the ink does not flow to the pressure storage tank 21 side. On the other hand, if the pressure value in the ink cartridge 9 remains higher than the predetermined threshold, the printing operation is continued, the printing operation is terminated (S47), and this sequence is terminated.

  FIG. 10 is a flowchart illustrating an example of a processing operation when the ink cartridge 9 is pressurized at the start of the cleaning operation in the recording apparatus.

  First, in the initial state at the start of the cleaning operation, the switching valve 14 is set to close the pressure storage tank 21 side, the waste liquid recovery tank 22 side is set to open, and the pressure adjustment valve 15 is closed. In S51, it is determined whether the pressure value in the ink cartridge 9 detected by the second pressure sensor 17 is higher or lower than a predetermined threshold value. If the pressure value in the ink cartridge 9 is lower than the predetermined threshold value in S51, the process proceeds to S52, and the pressurizing operation and the pressure accumulating operation described in FIGS. 7 and 8 are executed.

  On the other hand, if the pressure value in the ink cartridge 9 is higher than the predetermined threshold value in S51, a cleaning operation is executed (S53). After the cleaning operation is completed, it is determined whether the pressure value in the ink cartridge 9 detected by the second pressure sensor 17 is higher or lower than a predetermined threshold (S54). When the pressure value in the ink cartridge 9 becomes lower than the predetermined threshold value, the process proceeds to S55, and the pressurizing operation and the pressure accumulating operation described with reference to FIGS. 7 and 8 are executed. On the other hand, if the pressure value in the ink cartridge 9 remains higher than the predetermined threshold after the cleaning operation, this sequence is terminated.

  As described above, through the above-described operations, the first pressure sensor 16 detects the air pressure introduced into the pressure storage tank 21 by the pump 27 and controls the opening / closing of the switching valve 14 and the operation of the pump 27. That is, when it is detected that the pressure in the pressure storage tank 21 has reached a predetermined pressure value, the switching valve 14 is switched to the waste liquid recovery tank 22 side so that the pressure in the pressure storage tank 21 is equal to or lower than a predetermined pressure. When it is detected that, the switching valve 14 is switched to the pressure storage tank 21 side and the pump 27 is controlled to operate. Therefore, the air pressure in the pressure storage tank 21 described above is maintained in a predetermined range by repeating this.

  In addition, by the above-described operations, the second pressure sensor 17 detects the air pressure introduced into the ink cartridge 9 by the pressure storage tank 21 and controls the opening / closing of the pressure adjustment valve 15. That is, when it is detected that the pressure in the ink cartridge 9 has reached a predetermined pressure value, the pressure control valve 15 is closed, and the pressure in the ink cartridge 9 is equal to or lower than a predetermined pressure. If detected, the pressure control valve 15 is controlled to open. Therefore, the air pressure applied to each of the ink cartridges 9a to 9d described above is maintained in a predetermined range by repeating this process.

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

  That is, since the pressurization operation for applying air pressure to the ink cartridge 9 and the suction operation for sucking and discharging ink from the recording head 30 are performed by using the same pump 27, the number of pumps 27 can be reduced and the apparatus cost can be reduced. In addition, the installation space for the pump 27 can be reduced, and the apparatus can be miniaturized. Also, the waste liquid discharged from the pump 27 by the suction operation is introduced into the waste liquid collection tank 22, and the pressurized air discharged from the pump 27 is introduced toward the downstream side of the connection path 13 in order to pressurize the ink cartridge 9. Therefore, the waste liquid sucked from the recording head 30 is introduced only into the waste liquid recovery tank 22 without going to the pressurizing system of the ink cartridge 9, so that the path of the waste liquid is complicated. Therefore, the reliability with respect to the leakage of the waste liquid is ensured, and the life prediction of the waste liquid recovery tank 22 can be reliably performed.

  In addition, a pressure storage tank 21 provided in the connection path 13 for storing pressurized air for pressurizing the ink cartridge 9 is further provided, and the switching valve 14 collects waste liquid discharged from the pump 27 during the suction. Since the pressure air introduced into the tank 22 and switched to introduce the pressurized air discharged from the pump 27 when the pressure storage tank 21 is stored into the pressure storage tank 21, the recording head 30 is sucked and the pressure storage tank 21 is stored. Since it is only necessary to operate the pump 27, the operating time of the pump 27 can be greatly shortened and the life of the pump 27 can be ensured.

  In addition, a pressure regulating valve 15 is provided that allows the ink cartridge 9 to be pressurized from the pressure tank 21 by opening and closing the communication state of the pressure tank 21 and the ink cartridge 9 regardless of the operating state of the pump 27. Therefore, since the ink cartridge 9 can be pressurized without operating the pump 27, the operating time of the pump 27 can be greatly shortened and the life of the pump 27 can be ensured. Further, since the ink cartridge 9 can be pressurized only by opening / closing the pressure regulating valve 15 without operating the pump 27, the ink cartridge 9 is pressurized when necessary regardless of whether the pump 27 is operated. The operating time of the pump 27 can be greatly shortened, and the life of the pump 27 can be ensured.

  Further, a first pressure sensor 16 for detecting the pressure of the pressure storage tank 21 is provided, and when the pressure detected by the first pressure sensor 16 is lower than a predetermined pressure, the pressure adjustment valve 15 is closed and the switching valve 14 is stored. Since the pressure storage tank 21 is stored by switching to the tank 21 side, it is only necessary to operate the pump 27 when the pressure in the pressure storage tank 21 is required. The operating time of the pump 27 is reliably shortened and the life of the pump 27 is extended. Can be secured.

  A second pressure sensor 17 for detecting the pressure of the ink cartridge 9 is provided, and the pressure adjustment valve 15 is opened to pressurize the ink cartridge 9 when the pressure detected by the second pressure sensor 17 is lower than a predetermined pressure. Since it is possible to pressurize the ink cartridge 9 without operating the pump 27 when it is necessary to pressurize the cartridge 9, it is possible to reliably shorten the operating time of the pump 27 and ensure the life of the pump 27.

  The ink cartridge 9 is pressurized during at least one of the following operations: when the power is turned on, when the ink ejection operation to the ejection target is started, that is, when printing is started, and when the suction operation, that is, when the cleaning operation is started. Since the pressure storage operation is executed when the pressure of the pressure storage tank 21 drops, the pump 27 can be operated when the pressure storage tank 21 needs to store pressure during the pressurizing operation of the ink cartridge 9. Well, the operating time of the pump 27 can be reliably shortened and the life of the pump 27 can be ensured.

  Further, when the pressure accumulation operation to the pressure accumulation tank 21 is started, if the printing operation is being performed, the pressure accumulation operation is executed after the printing operation is completed. Therefore, during the printing operation, ink is stored in the cap member 11a. Since there is a case where the ink has accumulated, it is possible to prevent ink from being introduced into the pressure storage tank 21 during the pressure storage operation.

  Further, when the pressure accumulation operation to the pressure accumulation tank 21 is started, if the cleaning operation is being performed, the pressure accumulation operation is executed after the cleaning operation is completed. Therefore, the ink is sucked by the cap member 11a during the cleaning operation. Therefore, it is possible to prevent ink from being introduced into the pressure storage tank 21 during the pressure storage operation.

  In addition, this invention is not limited to said each embodiment, It is the meaning including the following modifications.

  In each of the embodiments described above, the recording head 30 can be applied to a liquid ejecting apparatus that uses a piezoelectric vibrator as a pressure generating element that is a driving element that ejects liquid, or a liquid ejecting type that uses a heating element. It can also be applied to a device.

  In addition, a program for causing a computer device to execute the pressure operation method of the present invention can be provided by being recorded on a recording medium, or can be 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 plan view showing an example of an ink jet recording apparatus according to the present invention. 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. FIG. 2 is a schematic diagram illustrating an ink supply path in the recording apparatus. It is a functional block diagram which shows the system configuration | structure of the said recording device. It is a flowchart which shows the 1st example of a cartridge pressurization operation | movement. It is a flowchart which shows the detail of cartridge pressurization operation | movement. It is a flowchart which shows the detail of a pressure accumulation operation | movement. It is a flowchart which shows the 2nd example of cartridge pressurization operation | movement. It is a flowchart which shows the 3rd example of cartridge pressurization operation | movement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carriage, 2 Carriage motor, 3 Timing belt, 4 Scanning guide member, 5 Paper feed member, 7 Pressure adjustment part, 7a-7d Pressure adjustment part, 8 Cartridge holder, 9 Ink cartridge, 9a-9d Ink cartridge, 10 Ink supply Tube, 11 Capping means, 11a Cap member, 12 Wiping member, 13 Connection path, 14 Switching valve, 15 Pressure regulating valve, 16 First pressure sensor, 17 Second pressure sensor, 20 Cartridge case, 21 Pressure storage tank, 22 Waste liquid Collection tank, 23 pressure chamber, 24 ink pack, 25 nozzle opening, 26 ink supply valve, 27 pump, 30 recording head, 31 ink supply needle, 31a ink introduction hole 32 filter 33 filter case, 34 head body, 35 ink communication flow , 37 self-sealing valve, 44 a host computer, 45 a printer driver, 46 printing control means, 47 a carriage control unit, 48 a head driving means 49 cleaning control means 50 pressurized control unit, 52 paper feed control means,

Claims (8)

An ejection head that ejects liquid toward the ejection target; a liquid cartridge that contains a flexible liquid pack in which the liquid to be supplied to the ejection head is enclosed;
A pump for sucking the internal space of the cap member that caps the nozzle surface of the ejection head;
A connection path for connecting the discharge side of the pump to the liquid cartridge so that the pump functions as a pressurizing means in the liquid cartridge;
A switching valve for introducing the waste liquid discharged from the pump by the suction operation into the waste liquid collecting means and introducing the pressurized air discharged from the pump toward the downstream side of the connection path in order to pressurize the liquid cartridge; A liquid ejecting apparatus comprising the liquid ejecting apparatus.   A pressure storage tank for storing pressurized air for pressurizing the liquid cartridge provided in the connection path, wherein the switching valve introduces waste liquid discharged from the pump at the time of suction into the waste liquid recovery means, The liquid ejecting apparatus according to claim 1, wherein the pressurized air discharged from the pump during storage of the tank is switched to be introduced into the storage tank.   3. A pressure regulating valve is provided that enables the liquid cartridge to be pressurized from the pressure storage tank by opening and closing a communication state between the pressure storage tank and the liquid cartridge regardless of the operating state of the pump. Liquid ejector.   A first pressure sensor for detecting the pressure of the pressure storage tank; when the pressure detected by the first pressure sensor is lower than a predetermined pressure, the pressure control valve is closed and the switching valve is switched to the pressure storage tank side to store pressure The liquid ejecting apparatus according to claim 3, wherein the tank is pressurized.   5. The liquid according to claim 3, further comprising a second pressure sensor configured to detect a pressure of the liquid cartridge, wherein when the pressure detected by the second pressure sensor is lower than a predetermined pressure, the pressure adjustment valve is opened to pressurize the liquid cartridge. Injection device.   When pressure is applied to the liquid cartridge when the power is turned on, at the time of starting the liquid injection operation to the injection target, or at the time of starting the suction operation, and the pressure in the pressure storage tank drops during this pressure operation The liquid ejecting apparatus according to claim 2, wherein a pressure accumulation operation is performed on the liquid ejecting apparatus.   The pressure accumulation operation is executed after the end of the injection operation when the pressure accumulation operation to the pressure accumulation tank is started and the injection operation to the injection target is in progress. The liquid ejecting apparatus described.   The liquid ejecting apparatus according to any one of claims 2 to 7, wherein when the pressure accumulation operation to the pressure accumulation tank is started and the cleaning operation is being performed, the pressure accumulation operation is executed after the cleaning operation is completed. .

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