JP2013237209A - Maintenance method for liquid ejecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a maintenance method for a liquid ejecting apparatus, capable of quickly washing away sediment in a liquid flow passage supplying liquid to an ejecting mechanism.SOLUTION: A maintenance method for a liquid ejecting apparatus includes: a step, while ink (15) of a supply source supplied to an ink supply tube 31 is switched to washing liquid (35), of causing the switched washing liquid to flow into the ink supply tube by discharging the ink by the suction of a liquid suction mechanism 27 to replace at least some of the ink in a circulation flow passage JF with the washing liquid; a step of circulating the replacement washing liquid in the circulation flow passage together with the ink by the operation of a tube pump 40 to mix it with the ink; and a step of sucking the mixed liquid in which the washing liquid and the ink are mixed by the circulation from a nozzle 21a by the liquid suction mechanism to discharge it from a liquid ejecting head 21.

Description

  The present invention relates to a maintenance method for a liquid ejecting apparatus, and more particularly to a maintenance method for a liquid flow path for supplying a liquid to a liquid ejecting head.

  In general, inkjet printers are widely known as a type of liquid ejecting apparatus that ejects liquid onto a medium. This printer performs printing by ejecting ink (liquid) supplied from an ink cartridge (liquid container) to a medium (for example, paper) from a nozzle formed in a liquid ejecting head. In such a printer, pigment ink may be used in recent years in order to realize high-quality printing.

  The pigment ink has a problem that, as time passes, pigment particles settle in the ink solvent, and the density of the pigment ink is biased to change its color. In particular, when the liquid flow path from the ink cartridge to the liquid ejecting head is long, the pigment particles tend to settle in the liquid flow path. Accordingly, even if the ink stirred from the ink cartridge is supplied to the liquid flow path, the color tone of the pigment ink is not corrected unless the deviation in the concentration of the pigment ink is suppressed in the liquid flow path between the ink cartridge and the liquid ejecting head. It becomes difficult to suppress changes in

  Therefore, for example, Patent Document 1 proposes a technique for stirring ink in a liquid flow path. That is, another liquid flow path (ink) whose both ends are connected via a three-way valve to a liquid flow path (ink supply tube) that connects the ink cartridge (main tank) and the liquid ejection head (ink head). A circulation tube is formed by providing a reflux tube. In this technique, a circulation pump is provided in the other liquid flow path, and the ink is stirred by causing the ink to flow in the circulation flow path by the operation of the provided circulation pump.

JP 2009-279932 A

  However, in a printer that uses pigment ink, even if the ink is stirred using the technique disclosed in Patent Document 1, pigment particles settle in the liquid flow path when the printer is used for a long period of time. It may accumulate in a step or a depression formed at a joint between liquid flow paths. Therefore, as a method of washing the pigment particles (precipitate) accumulated in the liquid flow path and maintaining the liquid flow path, it is conceivable to wash the precipitate by flowing a washing liquid into the liquid flow path. As a method of flowing the cleaning liquid into the liquid flow path in this way, the cleaning liquid is supplied from the liquid supply source side with respect to the liquid flow path, and the ink already supplied in the liquid flow path is sucked out from the nozzle of the liquid ejecting head. A method of using the flow of the cleaning liquid when the amount of ink sucked out by the cleaning liquid is replaced with the cleaning liquid is conceivable.

  By the way, in a printer using pigment ink, a nozzle formed in a liquid ejecting head may be miniaturized in order to realize high quality printing. In such a case, the amount of ink sucked out from the miniaturized nozzle is reduced. As a result, since the flow rate of the cleaning liquid flowing in the liquid flow path is also reduced, the flow rate necessary for washing the precipitate cannot be obtained. Therefore, the amount of cleaning liquid used is increased because the time until the precipitate is washed away, and the pump driving time is shortened because the driving time of the suction pump for sucking out the liquid from the nozzle is increased.

  This situation is not limited to ink jet printers, but is generally common in liquid ejecting apparatuses that supply liquid to an ejecting mechanism via a liquid flow path and eject the liquid through nozzles provided in the ejecting mechanism. It was.

  The present invention has been made in view of the above circumstances, and mainly provides a maintenance method for a liquid ejecting apparatus that can wash away deposits in a liquid flow path for supplying liquid to an ejecting mechanism in a short time. Objective.

  In order to achieve the above object, a maintenance method for a liquid ejecting apparatus according to the present invention includes a liquid ejecting mechanism having a nozzle for ejecting liquid, and discharging the liquid from the liquid ejecting mechanism by suction of the liquid from the nozzle. A liquid suction mechanism, a first liquid channel for supplying the liquid to the liquid ejecting mechanism from the upstream side, which is the liquid supply source side, to the downstream side; and the first liquid channel, A second liquid channel that forms a circulation channel through which the liquid circulates between the liquid channel and one liquid channel; A liquid ejecting apparatus comprising: a circulation pump for flowing in a maintenance method for a liquid ejecting apparatus in which the inside of the first liquid flow path is washed away with a cleaning liquid, wherein the first liquid flow path is supplied to the first liquid flow path Before source In a state where the liquid is switched to the cleaning liquid, the switched cleaning liquid is caused to flow into the first liquid channel by discharging the liquid by suction by the liquid suction mechanism, and the liquid in the circulation channel A step of replacing at least a part of the liquid with the cleaning liquid, and the cleaning liquid replaced in the circulation channel is circulated in the circulation channel together with the liquid by the operation of the circulation pump and mixed with the liquid. And a step of sucking the liquid mixture, in which the cleaning liquid and the liquid are mixed by the circulation, from the nozzle by the liquid suction mechanism and discharging the liquid from the liquid ejection mechanism.

  According to this method, the cleaning liquid that has flowed into the circulation channel is quickly circulated in the circulation channel to be mixed with the liquid, and the sediment that has settled and accumulated in the first liquid channel is diffused into the mixture. Can be made. Then, by discharging the mixed liquid in which the precipitate is diffused from the nozzle, the inside of the liquid flow path for supplying the liquid to the liquid ejecting mechanism can be washed out in a short time.

  In the maintenance method for the liquid ejecting apparatus according to the aspect of the invention, the circulation pump starts the operation after the cleaning liquid flows in more than a liquid amount corresponding to half the volume of the circulation channel.

  According to this method, since about half of the flow path is filled with the cleaning liquid in the circulation flow path, the cleaning liquid can be quickly moved to the entire circulation flow path. Accordingly, it is possible to reduce the operation time of the circulation pump until the precipitate is diffused in the mixed liquid in which the cleaning liquid and the liquid are mixed.

In the maintenance method for the liquid ejecting apparatus according to the aspect of the invention, the circulation pump starts the operation after the cleaning liquid that has flowed into the first liquid flow path reaches the nozzle.
According to this method, since the cleaning liquid flows into the liquid flow path leading to the liquid ejecting mechanism located downstream from the circulation flow path, the first liquid flow path in which the cleaning liquid flows by the operation of the circulation pump. In the downstream flow channel other than the flow channel range of the circulation flow channel, the precipitate in the first liquid flow channel can be diffused into the cleaning liquid.

  In the maintenance method of the liquid ejecting apparatus according to the aspect of the invention, the circulation pump may be configured so that when the liquid is supplied to the liquid ejecting mechanism, the cleaning liquid is disposed in a direction opposite to a flow direction of the liquid flowing through the first liquid channel. To flow in the circulation channel together with the liquid.

  According to this method, the precipitate that has settled at a specific location by the flow at the time of supplying the liquid in the first liquid channel is caused to flow into the flowing cleaning liquid and liquid by flowing the liquid together with the cleaning liquid from the opposite direction. The probability that it can be diffused can be increased.

In the maintenance method for the liquid ejecting apparatus according to the aspect of the invention, the circulation channel is provided with at least one liquid storage section capable of storing the liquid.
According to this method, for example, when pulsation occurs in the liquid and the cleaning liquid flowing in the circulation flow path by the operation of the circulation pump, the pulsation can be suppressed by storing the flowing liquid and the cleaning liquid in the liquid storage unit. it can. As a result, the liquid and the cleaning liquid can be made to flow at a stable flow rate in the circulation channel.

  In the maintenance method for the liquid ejecting apparatus according to the aspect of the invention, the circulation pump may supply the cleaning liquid that has flowed into the circulation channel at a flow rate different from the flow rate of the liquid when the liquid flows in the circulation channel. It is made to flow with the liquid in the circulation channel.

  According to this method, for example, the circulation pump is operated so that the flow rates of the solutes contained in the liquid differ depending on the difference between the dispersibility of the solute in the liquid and the dispersibility of the mixed liquid (cleaning liquid). By this, the sediment which the solute settled and collected can be efficiently disperse | distributed in a liquid mixture.

1 is a schematic configuration diagram of a printer that is an embodiment of a liquid ejecting apparatus according to the invention. FIG. FIG. 4 is a schematic diagram illustrating a configuration related to a cleaning operation of an ink supply tube in the printer of the present embodiment. 7 is a flowchart showing a cleaning process of an ink supply tube with a cleaning liquid. FIG. 5 is a schematic diagram illustrating an operation state of the cleaning process of the ink supply tube, where (a) illustrates a state in which the cleaning liquid flows into the circulation channel, and (b) illustrates a state in which the cleaning liquid circulates in the circulation channel together with the ink. FIG. (A) is a schematic diagram showing a circulation flow path that does not have a liquid reservoir in the ink supply tube of the present embodiment, and (b) shows ink and cleaning liquid instead of the liquid body reservoir in the ink supply tube of the present embodiment. The schematic diagram which shows the circulation flow path provided with the subtank to store. The schematic diagram which shows the other structure of a circulation channel in a modification. The schematic diagram which shows the other structure of a circulation channel in a modification.

  Hereinafter, an embodiment in which a liquid ejecting apparatus according to the invention is embodied in an ink jet printer (hereinafter also referred to as “printer”) will be described with reference to the drawings. The printer according to this embodiment forms an image including characters and figures by ejecting liquid supplied from a liquid supply source via a liquid flow path to a medium conveyed in one direction from a liquid ejecting mechanism.

  As shown in FIG. 1, a sheet S which is an example of a medium along the longitudinal direction X is formed in a lower portion on the gravity direction side in a frame 12 having a substantially rectangular box shape in a printer 11 as an example of a liquid ejecting apparatus. A support member 13 is extended to support the image during image formation, that is, during printing. Then, a paper feed mechanism (not shown) is driven based on the drive of a paper feed motor (not shown) provided in the lower part of the rear of the frame 12 in the direction opposite to the conveyance direction Y of the paper S. By the mechanism, the short direction (front direction) intersecting the longitudinal direction X of the support member 13 is transported on the support member 13 as the transport direction Y.

  The cartridge holder 14 disposed on one end side in the longitudinal direction X of the frame 12 (right end side when viewed from the front side in the transport direction Y in this embodiment) stores liquid as an example of liquid. A plurality (four in this case) of ink cartridges 15 as an example of a body are detachably mounted as liquid supply sources. In the present embodiment, each ink cartridge 15 contains different colors of ink and is mounted on the cartridge holder 14. Each ink cartridge 15 contains pigment ink.

  A guide shaft 19 extending along the longitudinal direction X is installed in the frame 12, and a carriage 20 is slidably supported on the guide shaft 19. The carriage 20 is fixed to a part of an endless timing belt 17 that is rotationally driven by a carriage motor 16 provided on the upstream side (rear side) in the conveyance direction of the frame 12. Accordingly, the carriage 20 is reciprocated along the guide shaft 19 with the longitudinal direction X as the scanning direction by driving the timing belt 17 by driving the carriage motor 16. The carriage 20 is provided with a liquid ejecting head 21 as a liquid ejecting mechanism provided with a plurality of nozzles 21 a (see FIG. 2) for ejecting ink on the lower surface side, and the liquid ejecting head provided corresponding to each ink cartridge 15. A plurality of valve units 25 that control the supply of ink to the head 21 are mounted.

  One end side (the cartridge holder 14 side in the present embodiment) in the movement range along the scanning direction of the carriage 20 in the frame 12 is a non-medium ejection area other than the medium ejection area, and a home position HP is provided in this area. Yes. A maintenance device 22 for performing various maintenance processes on the liquid ejecting head 21 is disposed at the home position HP.

  The maintenance device 22 raises the cap 27a from below and makes contact with the liquid jet head 21 moved to the home position HP, and the suction pump 29 brings the closed space formed by the contact into a negative pressure state. Thus, a liquid suction mechanism 27 for sucking ink from the nozzles 21a is provided. Alternatively, a receiving portion (not shown) that receives the ejected ink is provided, and the ink is forcibly ejected from the nozzle 21a to the receiving portion. By doing so, the maintenance device 22 discharges, for example, thickened ink from the nozzle 21a and performs maintenance for stabilizing the ink ejection operation from the nozzle 21a. The discharged ink is stored in a waste liquid tank (not shown).

  In the present embodiment, one end is connected to the ink cartridge 15 serving as a liquid supply source, and the other end is connected to the liquid ejecting head 21 via the valve unit 25 located on the downstream side with the ink cartridge 15 as the upstream side. The ink supply tube 31 connected to the is provided as a first liquid flow path. Accordingly, the ink is supplied from each ink cartridge 15 to the liquid ejecting head 21 via each ink supply tube 31.

  The valve unit 25 is a so-called self-sealing valve that opens and supplies ink from the upstream side to the liquid ejecting head 21 (nozzle 21a) when ink is ejected from the ejecting nozzle and the ink pressure drops. A functioning pressure control valve 24 is provided. The ink supply tube 31 is connected to the upstream side of the pressure control valve 24.

  The ink supply tube 31 is provided with a check valve 23 provided with an on-off valve 23a (see FIG. 2) on the upstream side of the pressure control valve 24. The check valve 23 opens the on-off valve 23a when ink flows from the upstream ink cartridge 15 side toward the downstream pressure control valve 24 side, while the downstream side pressure control valve 24 side upstream. When the ink is about to flow toward the ink cartridge 15 side, the on-off valve 23a is closed to prevent the flow.

  The ink supply tube 31 is provided with a switching valve 36 between the check valve 23 and the ink cartridge 15, and the cleaning liquid cartridge 35 containing the cleaning liquid is connected to the switching valve 36 via the cleaning liquid supply tube 31S. Yes. The switching valve 36 has, for example, a three-way valve structure, and includes a state in which ink is supplied from the ink cartridge 15 and a state in which cleaning liquid is supplied from the cleaning liquid cartridge 35 downstream of the switching valve 36 in the ink supply tube 31. Switching to either state is possible. In FIG. 1, only one cleaning liquid cartridge 35 is shown for simplification of description, but four cleaning liquid cartridges 35 are respectively supplied to the four ink cartridges 15 by the switching valves 36 respectively. Connected to the tube 31.

  Further, although the ink supply tube 31 is shown as a block in FIG. 1 between the pressure control valve 24 and the check valve 23, another liquid flow path whose both ends are connected to the ink supply tube 31. And a circulation flow path JF is formed through which ink circulates between the ink supply tube 31 and the ink supply tube 31. The configuration of each liquid flow path including the circulation flow path JF and extending from the ink cartridge 15 and the cleaning liquid cartridge 35 to the liquid ejecting head 21 will be described with reference to FIG.

  In the present embodiment, all the liquid channels have the same configuration. Therefore, in FIG. 2, the components of the liquid flow path including one circulation flow path JF are schematically illustrated for the sake of simplicity of explanation. In FIG. 2, each component constituting the liquid flow path is illustrated as a continuous member, but in actuality, it is formed by a plurality of members connected to each other.

  As shown in FIG. 2, an ink circulation tube 32 is provided as a second liquid flow path having both ends connected to the ink supply tube 31 by connecting portions C1 and C2, and the ink circulation tube 32 and the ink supply are provided. A circulation channel JF in which ink circulates between the tube 31 is formed. The ink circulation tube 32 is provided with a tube pump 40 that performs a pumping operation for causing ink to flow in the circulation flow path JF. Further, the ink supply tube 31 is provided in a flow path portion 31c between both connection portions C1 and C2 to which the ink circulation tube 32 is connected, and functions as a buffer for temporarily storing the ink in a pressurized state. A liquid reservoir 50 is provided. In the present embodiment, the connecting portion C1 is a connecting portion on the side close to the check valve 23 among the connecting portions C1 and C2.

  The tube pump 40 includes a roller 42 movably provided on a rotating body 41 in a curved portion 32R in which a flexible tube (here, a part of the ink circulation tube 32) is formed in an arc shape. The ink is forced to flow in one direction in the circulation flow path JF by pushing the ink in the rotation direction in accordance with the rotation in one direction of the rotating body 41 rotated by the rotation. That is, when the roller 42 enters the curved portion 32 </ b> R, the roller 42 moves along the guide hole 43 so as to move away from the rotation center of the rotating body 41 and crushes the ink circulation tube 32. By this crushing, the ink in the ink circulation tube 32 is in a pressurized state. Then, the roller 42 rotates (revolves) together with the rotator 41 while crushing the ink circulation tube 32, whereby the ink in the ink circulation tube 32 is pushed out in the rotation direction of the roller 42 while being pressurized and circulated. It is allowed to flow in one direction in the road JF.

  In the tube pump 40, the ink in the ink circulation tube 32 is in a pressurized state and a depressurized state in order to repeat the state in which the ink circulation tube 32 is crushed by the roller 42 and the state in which it is not crushed as the roller 42 rotates. repeat. Therefore, the tube pump 40 is a circulation pump that causes pressure fluctuation (pulsation) between the pressurized state and the decompressed state for the ink in the ink circulation tube 32 during operation.

  The liquid storage section 50 includes a container body 51 formed with a communication section 55 that communicates the ink supply tube 31 and the ink flow path, and a displacement plate 53 that is displaced so as to change the volume in the container body 51. have. In the present embodiment, the displacement plate 53 is formed of a flat plate member, and moves away from the communication portion 55 side with the ink circulation tube 32 while closely contacting the periphery of the inner wall 51a of the container body 51. The internal volume of the container body 51 is increased, and the amount of ink that can be stored in the liquid storage unit 50 is increased.

  Further, as indicated by an arrow G in FIG. 2, the displacement plate 53 is urged so as to move in a direction in which the internal volume is changed to be small by a pressurizing unit 54 configured by, for example, a coil spring. Therefore, when the displacement plate 53 moves against the urging force of the pressurizing unit 54, the liquid can be temporarily stored in the liquid storage unit 50 while being pressurized by the pressurizing unit 54. Increase fluid volume. Therefore, the liquid reservoir 50 absorbs ink pressure fluctuations in the circulation flow path that occur during operation of the tube pump 40 by increasing or decreasing the amount of ink stored. In the present embodiment, the inner wall 51a of the container body 51 is formed with a protrusion 52 that protrudes in a bowl shape toward the center so as to engage with the displacement plate 53 when viewed from above. However, the state in which the movement of the pressurizing unit 54 in the urging direction is restricted by the protrusion 52 is a state in which the amount of liquid stored in the liquid storage unit 50 is zero.

  In the case where an image is formed (printed) on the paper S in the flow path portion 31a on the upstream side of the connection portion C1 in the ink supply tube 31 in which the circulation flow path JF is formed in this way, FIG. As shown, ink is supplied from the ink cartridge 15 through the check valve 23 by the switching operation of the switching valve 36. That is, when ink is ejected from the liquid ejecting head 21 (nozzle 21a) onto the paper S and consumed, the pressure of the liquid ejecting head 21 is reduced, and the pressure control valve 24 is opened and connected to the pressure control valve 24. The ink in the flow path portion 31b on the downstream side of the connection portion C2 in the ink supply tube 31 is supplied to the liquid ejecting head 21 via the pressure control valve 24. As a result, as indicated by a solid arrow Fs in the drawing, ink flows from the flow passage portion 31a to the flow passage portion 31b through the flow passage portion 31c in the ink supply tube 31. As shown, the on-off valve 23a is opened and ink is supplied from the ink cartridge 15 to the flow path portion 31a.

  The ink flowing through the ink supply tube 31 at the time of printing such an image flows at the amount of liquid consumed by printing, so the flow rate is slow, and therefore the pigment component (solute) in the ink tends to settle in the flow path. Become. As a result, the sediment 38 may be formed by accumulation of the settled pigment component (solute). In FIG. 2, the precipitate 38 is illustrated as being formed at the position of the liquid reservoir 50 in the flow path portion 31 c for simplification of description. Of course, as described above, precipitates are likely to be formed in steps or depressions in the flow path.

  Therefore, in the printer 11, in order to disperse the precipitate 38 in the ink solvent, a stirring operation is performed in which the tube pump 40 is operated to circulate and flow the ink in the circulation flow path. At this time, in this embodiment, as indicated by a broken-line arrow Fk in the drawing, in the flow path portion 31c of the ink supply tube 31, the ink flows in a direction opposite to the ink flow direction when the ink is supplied to the liquid ejecting head 21. The tube pump 40 (rotating body 41) is rotated in one direction indicated by an arrow R in the figure so as to flow.

  Furthermore, in the printer 11 of the present embodiment, for example, a washing operation is performed in which the precipitate 38 that remains without being dispersed by the stirring operation is washed away with the washing liquid. The cleaning operation is performed by the control unit 60 provided in the printer 11. In the present embodiment, the stirring operation is also performed by the control unit 60.

  The control unit 60 rotates the carriage motor 16 by the control signal 61 to move the carriage. Further, the cap 27 a is moved up and down by the control signal 62, and the suction pump 29 is operated by the control signal 69 while the cap 27 a is in contact with the liquid jet head 21. Further, the control unit 60 displaces the valve body 36a in the switching valve 36 by the control signal 63 as indicated by a solid line and a two-dot chain line in the drawing, and the ink and the upstream of the check valve 23 in the ink supply tube 31 are discharged. Supply one of the cleaning solutions. Further, the tube pump 40 is operated by the control signal 64. Further, the control unit 60 determines the diffusion state of the precipitate 38 in the ink supply tube 31 based on the detection signal 65 output from the detection sensor 56 provided in the circulation flow path JF. The detection sensor 56 is an optical sensor, for example, and outputs a signal indicating a level value indicating the transparency of the liquid (cleaning liquid and ink) in at least a light-transmitting flow path portion.

  Next, the cleaning operation (action) performed by the control unit 60 will be described with reference to the processing flow shown in FIG. 3 and FIGS. 4 (a) and 4 (b). This cleaning operation is performed in a state where the liquid jet head 21 has moved to the home position HP. Alternatively, for example, the state in which ink is supplied from the ink cartridge 15 to the liquid ejecting head 21 in the printer 11 is automatically performed every time a predetermined time elapses, or the detection signal 65 output from the detection sensor 56 is, for example, a precipitate This is sometimes done when a level value is output indicating that the amount of the object needs to be diffused.

  As shown in FIG. 3, when the cleaning operation is started, the control unit 60 determines whether or not the ink stirring operation is stopped in step S1. Here, the control part 60 determines by the presence or absence of the output of the control signal 64 with respect to the tube pump 40. FIG. The tube pump 40 is in a state in which a flow path where the roller 42 does not crush the ink circulation tube 32 is opened in a state where the stirring operation is stopped.

  If the stirring operation is stopped as a result of the determination process in step S1 (S1 = YES), the process proceeds to step S2 to perform a process of switching the supply source liquid from ink to cleaning liquid. That is, the control unit 60 outputs the control signal 63 to the switching valve 36 to displace the valve body 36a, thereby shutting off the ink supply and supplying the cleaning liquid from the cleaning liquid cartridge 35 to the upstream side of the check valve 23. Like that.

  Subsequently, in step S3, a process of sucking the liquid from the nozzle of the liquid jet head is performed. Here, the control unit 60 outputs a control signal 62 to raise the cap 27a to contact the liquid ejecting head 21, and a space formed between the liquid ejecting head 21 and the cap 27a formed by the contact. The control signal 69 is output to drive the suction pump 29 to reduce the pressure, and the ink as a liquid is sucked from the nozzle 21a.

  Subsequently, in step S5, it is determined whether or not a set amount of liquid has been discharged from the nozzle. As a result of the determination process in step S5, when it is determined that the liquid is not discharged from the nozzle (S5 = NO), the process returns to step S3 and the liquid suction from the nozzle of the liquid ejecting head is continued. Here, the control unit 60 calculates the total amount of ink discharged from the nozzles 21a of the liquid ejecting head 21 based on the drive time of the suction pump 29, and determines whether the calculated value exceeds the set amount. judge. In the present embodiment, the set amount is a liquid amount in which the cleaning liquid that has been replaced with the ink in the ink supply tube 31 and has entered at least a part of the circulation flow path JF.

  An example of the inflow state of the cleaning liquid into the circulation flow path JF by the processing in step S3 and step S5 is illustrated in FIG. As shown in FIG. 4A, the cleaning liquid supplied from the cleaning liquid cartridge 35 flows through the ink supply tube 31 via the check valve 23 as the ink is sucked from the liquid ejecting head 21 (nozzle 21a). It flows into the road part 31a.

  The cleaning liquid that has flowed into the flow path portion 31a from the ink cartridge 15 is caused by the crushing of the ink circulation tube 32 by the curved portion 32R and the roller 42 constituting the tube pump 40 toward the ink circulation tube 32 side in the circulation flow path JF. The flow resistance makes it difficult to flow. For this reason, most of the cleaning liquid flows toward the flow path portion 31c side where the flow path resistance is lower than the ink circulation tube 32 side by providing the liquid storage section 50. Then, as indicated by the solid arrow Fs in the figure, the cleaning liquid further moves the flow path part 31c toward the flow path part 31b so as to replace at least part of the ink in the circulation flow path JF in the ink supply tube 31. To flow. Incidentally, FIG. 4A shows a state in which the cleaning liquid flows into the connection portion C2.

  Returning to FIG. 3, when it is determined that the set amount of liquid is discharged from the nozzle as a result of the determination process in step S <b> 5 (S <b> 5 = YES), the suction of the liquid from the nozzle of the liquid ejecting head is terminated in subsequent step S <b> 6. Then, the circulating pump is driven for a predetermined time. Here, the control unit 60 outputs a control signal 64 to drive the tube pump 40 as a circulation pump for a predetermined time (for example, 1 minute), and the ink that has flowed in the circulation channel JF remains in the circulation channel JF. And circulate together. At this time, the flow rate of the liquid (ink and cleaning liquid) flowing by the tube pump 40 is the same as the flow rate of the ink in the ink stirring operation.

  Further, in the present embodiment, a process for reciprocating the carriage is performed in the next step S7. The control unit 60 outputs a control signal 61 to rotate the carriage motor 16 to reciprocate the carriage 20 in the longitudinal direction X (scanning direction). That is, by reciprocating the carriage 20, the precipitate is diffused in a portion other than the circulation flow path JF, particularly in the flow path portion 31b where the cleaning liquid hardly flows because it is farthest from the supply source of the cleaning liquid in the ink supply tube 31. . In this process, the control unit 60 outputs a control signal 62 as necessary to lower the cap 27a, and the cap 27a is separated from the liquid ejecting head 21, so that the movement of the carriage 20 is not suppressed by the cap 27a. To.

  The flow state of the cleaning liquid in the processing in step S6 and step S7 is illustrated in FIG. As shown in FIG. 4B, in the tube pump 40, in the operation state of the pump in which the roller 42 rotates while crushing the curved portion 32R of the ink circulation tube 32, as shown by the solid line arrow Fa in the drawing, the curved portion 32R. The ink that has been pressurized and pushed out from the ink flows in the circulation flow path JF in one direction and circulates and flows. At this time, since the cleaning liquid that has flowed into the flow path portion 31c of the ink supply tube 31 is circulated and flowed together with the ink, the cleaning liquid is mixed with the ink and becomes a mixed liquid as shown by thin shading in the figure, and the circulation flow path Flow JF. When the liquid mixture flows in the circulation flow path JF in this way, the precipitate 38 formed in the flow path portion 31c is wound up by the liquid mixture flowing and dispersed in the liquid mixture. As a result, the amount of the precipitate 38 decreases.

  In other words, the tube pump 40 causes the mixed liquid to flow at a flow rate (flow rate per unit time) at which the sediment can be dispersed in the circulation flow path JF. In this embodiment, the flow rate when circulating in the circulation channel JF is sucked from the nozzle 21a in the speed at which the cleaning liquid flows into the circulation channel JF via the check valve 23, that is, in the process of step S3. Compared to the amount of ink per unit time, the flow rate is twice or more.

  As described above, in the ink circulation tube 32 whose flow path resistance is increased due to the tube pump 40 provided by the processing in step S6, the cleaning liquid flowing from the upstream side through the check valve 23 is used as the ink. At the same time, it can be circulated in the circulation flow path JF. As a result, even if a precipitate is generated in the ink circulation tube 32 in which the cleaning liquid is not flowing in when the cleaning liquid is replaced with the ink, the flowing cleaning liquid or the mixed liquid of the cleaning liquid and the ink causes the precipitation. The precipitate can be dispersed.

  When the liquid reservoir 50 is provided in the circulation flow path JF, a part of the ink flowing through the ink supply tube 31 by the operation of the tube pump 40 is communicated as shown by the solid arrow Fe in FIG. The liquid flows into the liquid storage part 50 from the part 55 and is stored. At this time, the liquid reservoir 50 is displaced by moving the displacement plate 53 away from the ink supply tube 31 as shown by the two-dot chain line and the solid line in FIG. The change in flow rate accompanying the pulsation of the liquid mixture is absorbed by this volume change. As a result, the mixed solution flows through the circulation channel JF at a stable flow rate, and the precipitate is stably diffused into the mixed solution by the flow rate.

  In the operation state of the tube pump 40, the pressure on the downstream side with respect to the check valve 23 increases, so that the on-off valve 23a is closed and ink flows from the cleaning liquid cartridge 35 side to the circulation flow path JF side. Absent. Also, the closed state of the pressure control valve 24 is maintained also on the liquid ejecting head 21 side, and the circulating liquid mixture does not flow from the ink supply tube 31 side.

  Returning to FIG. 3, in step S8, a process of sucking a predetermined amount of liquid from the nozzles of the liquid jet head is performed. Here, when the cap 27 a is lowered, the control unit 60 first outputs the control signal 62 to raise the cap 27 a to contact the liquid ejecting head 21. Thereafter, the control signal 69 is output to drive the suction pump 29 for a predetermined time, thereby sucking the liquid, that is, the mixed liquid in which the precipitate 38 is diffused, from the nozzle 21a.

  In the present embodiment, as the predetermined amount of the liquid mixture sucked from the nozzle 21a in the process of step S8, the liquid corresponding to the added volume of the volume of the flow path part 31b and the volume of the flow path part 31c in the ink supply tube 31 More than the amount. In this way, the mixed liquid in which the precipitate is diffused is discharged by suction from the flow path part 31 c and the flow path part 31 b in the ink supply tube 31, and a new cleaning liquid flows in through the check valve 23. To replace.

  Next, in step S10, it is determined whether or not the transparency of the liquid is equal to or greater than a threshold value. The control unit 60 determines whether or not the level value of the signal indicating the transparency, that is, the transparency output from the detection sensor 56, is equal to or greater than a predetermined threshold value. The threshold value is, for example, a level value output from the detection sensor in the state where the precipitate 38 is not formed in the circulation flow path JF.

  As a result of the determination process in step S10, if the transparency of the liquid is lower than the threshold value (S10 = N0), it is estimated that the precipitate 38 still remains because a large amount of solute is dispersed in the mixed liquid. Therefore, it returns to step S3 and repeats the process from step S3 to step S10. In the present embodiment, when the predetermined amount of liquid sucked from the nozzle 21a exceeds the set amount determined in step S5 in the process of step S8, the process is performed in parallel with the process of step S3. In step S5 (S5 = YES), the process proceeds to step S6 without actually executing step S3.

  If the result of determination in step S10 is that the transparency of the liquid is greater than or equal to a threshold value (S10 = YES), the process proceeds to step S12 to perform processing for switching the supply source liquid from cleaning liquid to ink. That is, the control unit 60 outputs the control signal 63 to displace the valve body 36a of the switching valve 36, thereby shutting off the cleaning liquid and supplying the ink from the ink cartridge 15 to the upstream side of the check valve 23. To do.

  Subsequently, in step S13, the liquid is sucked from the nozzle of the liquid jet head. The control unit 60 outputs a control signal 69 and drives the suction pump 29 to depressurize the space formed between the liquid ejecting head 21 and the cap 27a, so that the liquid mixture or cleaning liquid as a liquid is nozzleed. Aspirate from 21a.

  Subsequently, in step S15, it is determined whether or not a set amount of liquid has been discharged from the nozzle. Then, as a result of the determination process in step S15, when it is determined that the liquid is not discharged from the nozzle (S15 = NO), the process returns to step S13 and the liquid suction from the nozzle of the liquid ejecting head is continued. Here, the control unit 60 calculates the total liquid amount of the mixed liquid or the cleaning liquid discharged from the nozzle 21a of the liquid jet head 21 based on the driving time of the suction pump 29, and whether the calculated value exceeds the set amount Judge by no. In the present embodiment, this set amount is the amount of ink that flows into the circulation flow path JF at least after the ink that has been replaced with the mixed liquid or the cleaning liquid in the ink supply tube 31 flows, and preferably up to the connection portion C2. It is the amount of liquid that enters the state.

  If it is determined in step S15 that the liquid has been discharged from the nozzle by a predetermined amount (S15 = YES), the suction of the liquid from the nozzle of the liquid ejecting head is terminated in step S16, and the circulation pump Is driven for a predetermined time. Here, the control unit 60 stops the output of the control signal 69 while outputting the control signal 64 to drive the tube pump 40 as a circulation pump for a predetermined time (for example, 1 minute), so that the ink that has flowed into the circulation flow path JF. Is circulated and flowed together with the remaining mixed liquid.

  It should be noted that the flow rate of the liquid in step S16 is different from the flow rate of the liquid circulated in step S6. That is, the tube pump 40 is configured to reduce the dispersibility of the ink solute in the mixed liquid, that is, the dispersibility of the ink solute in the solvent in which the cleaning liquid and the ink solvent are mixed, and the ink solute in the solvent containing only the ink. It is driven so that the flow rate varies depending on the difference from the dispersibility. For example, when the ink solute settles quickly in the cleaning liquid, the flow rate is increased. Conversely, when the ink solute settles slowly, the flow rate is decreased.

  Next, in step S18, a process of sucking a predetermined amount of liquid from the nozzle of the liquid jet head is performed. The control unit 60 outputs a control signal 69 and drives the suction pump 29 for a predetermined time, thereby sucking the liquid mixture or ink as a liquid from the nozzle 21a. In the present embodiment, the volume of the flow path part 31b and the volume of the flow path part 31c in the ink supply tube 31 are set as the predetermined amount of the liquid mixture sucked from the nozzle 21a in the process of step S18, as in step S8. The amount of liquid is equal to or larger than the amount of liquid added. By doing so, the mixed liquid is discharged from the flow path part 31 c and the flow path part 31 b in the ink supply tube 31, and ink is allowed to flow through the check valve 23 to be replaced.

  Next, in step S20, it is determined whether or not the transparency of the liquid is equal to or less than a threshold value. The controller 60 determines whether the level value of the signal indicating transparency output from the detection sensor 56 is equal to or less than a predetermined threshold value. The threshold value is, for example, a level value output by the detection sensor in a state where only ink flows in the flow path portion 31c of the ink supply tube 31.

  As a result of the determination process in step S20, when the transparency of the liquid is higher than the threshold value (S20 = N0), the process returns to step S16, and the processes in steps S16 and S18 are repeated. That is, since the mixed liquid (cleaning liquid) still remains in the ink supply tube 31, the control unit 60 outputs the control signal 64 and drives the tube pump 40 for a predetermined time, and then outputs the control signal 69. The suction pump 29 is output for a predetermined time.

  If the result of determination in step S20 is that the transparency of the liquid is less than or equal to the threshold (S20 = YES), the ink cleaning operation ends. That is, in this embodiment, it is estimated that the cleaning liquid is discharged and only the ink flows in the flow path portion 31c of the ink supply tube 31, and therefore, the liquid is supplied to the liquid ejecting head 21 through the flow path portion 31b. Since the ink to be used becomes ink that can be used for printing, the ink cleaning operation is terminated.

According to the embodiment described above, the following effects can be obtained.
(1) The cleaning liquid that has flowed into the circulation flow path JF is quickly circulated in the circulation flow path JF to be mixed with ink, and the sediment 38 that has settled and accumulated in the ink supply tube 31 is diffused into the liquid mixture. Can do. Then, by discharging the mixed liquid in which the precipitate 38 is diffused from the nozzle 21a, the inside of the liquid flow path for supplying ink to the liquid ejecting head 21 can be washed away in a short time. Further, since the cleaning liquid does not flow into the entire ink supply tube 31, the suction time for sucking the liquid (ink) from the nozzle 21a is also shortened. As a result, the driving time of the suction pump 29 can be suppressed, and the amount of cleaning liquid used can be suppressed. Further, in the ink circulation tube 32 provided with the tube pump 40, for example, even in the ink circulation tube 32 in which the cleaning liquid does not easily flow due to the flow path resistance of the tube pump 40 provided, the inside of the circulation flow path is circulated by the operation of the tube pump 40. It is possible to make it. Therefore, even if the precipitate 38 is generated in the ink circulation tube 32, it can be diffused.

  (2) The precipitate that has settled at a specific location by the flow at the time of ink supply in the ink supply tube 31 can be diffused into the flowing cleaning liquid and ink by flowing the ink together with the cleaning liquid from the opposite direction. Probability can be increased.

  (3) For example, when pulsation occurs in the ink and the cleaning liquid flowing through the circulation flow path JF by the operation of the tube pump 40, the pulsation is suppressed by storing the flowing ink and the cleaning liquid in the liquid storage unit 50. it can. As a result, the ink and the cleaning liquid can be flowed at a stable flow rate in the circulation flow path JF.

  (4) For example, by operating the tube pump 40 so that the flow rates of the solutes contained in the ink differ depending on the difference between the dispersibility in the ink and the dispersibility in the mixed liquid (cleaning liquid). The sediment 38 in which the solute settles and can be efficiently dispersed in the mixed solution.

The above embodiment may be changed to another embodiment as described below.
In the processing in step S5 in the cleaning operation in the above embodiment, the set amount that is the discharge amount of the ink discharged from the nozzle 21a is a liquid whose cleaning liquid corresponds to half the total flow path volume of the circulation flow path JF. It may be an amount.

  In other words, in this modification, the total volume of the internal volume of each of the flow path portion 31c of the ink supply tube 31, the ink circulation tube 32, the connection portion C1, and the connection portion C2 and the internal volume of the liquid storage portion 50 is summed. The amount of liquid corresponding to half the volume is set as the set amount. More preferably, the amount of liquid obtained by adding the internal volume of the flow path portion 31a of the ink supply tube 31 to this is set as the set amount.

  As a result, when the lengths of the ink supply tube 31 (flow path portion 31c) and the ink circulation tube 32 are approximately the same, approximately half of the ink in the flow path is replaced with the cleaning liquid in the circulation flow path JF. Accordingly, in the subsequent processing of step S6, the tube pump 40 starts operation after the cleaning liquid has flowed in at least a liquid amount corresponding to half of the total flow path volume of the circulation flow path JF.

According to this modification, in addition to the effects (1) to (4) in the above embodiment, the following effects can be obtained.
(5) Since about half of the flow path in the circulation flow path JF is filled with the cleaning liquid, the cleaning liquid can be quickly moved over the entire circulation flow path JF. Therefore, it is possible to reduce the operation time of the tube pump 40 until the precipitate 38 diffuses into the mixed liquid in which the cleaning liquid and the ink are mixed.

  Alternatively, in the processing step S5 of the cleaning operation in the above-described embodiment, the cleaning liquid that has flowed into the ink supply tube 31 via the check valve 23 at a set amount that is the amount of ink discharged from the nozzle 21a is liquid ejected. The amount of liquid until the nozzle 21a of the head 21 is reached may be used. For example, when the cleaning liquid hardly flows to the ink circulation tube 32 side, the total internal volume of the flow path portions 31 a, 31 c, 31 b in the ink supply tube 31, the internal volume of the liquid reservoir 50, and the pressure control valve 24 The liquid amount corresponding to the total volume of the internal volume of the flow path to the nozzle 21a is set as the set amount.

  Thus, even when the ink supply tube 31 (flow path portion 31c) is a flow path longer than the ink circulation tube 32, the ink is also washed in the flow path portion 31b downstream from the circulation flow path JF. Is replaced by Accordingly, in the subsequent step S6, the tube pump 40 starts operating after the cleaning liquid that has flowed into the ink supply tube 31 reaches the nozzle 21a.

According to this modification, in addition to the effects (1) to (4) in the above embodiment, the following effects can be obtained.
(6) Since the cleaning liquid is in a state of flowing into the liquid flow path from the circulation flow path JF to the liquid jet head 21 located on the downstream side, the cleaning liquid circulates in the ink supply tube 31 in which the cleaning liquid flows by the operation of the tube pump 40. The sediment 38 can be diffused into the cleaning liquid also in the downstream flow path portion 31b other than the flow path range of the flow path.

  In the processing step S5 of the cleaning operation in the above embodiment, a state in which a set amount of ink is discharged from the nozzle 21a may be detected by a detection sensor. For example, when the amount of liquid that the cleaning liquid reaches the nozzle 21a is set as in the modification example, the liquid ejecting head 21 includes a detection sensor (for example, an optical sensor) that can detect the cleaning liquid in the nozzle 21a. You may make it detect with a detection sensor whether the washing | cleaning liquid reached | attained. That is, for example, when a detection signal indicating that the cleaning liquid has reached the liquid jet head 21 is output from the detection sensor, the control unit 60 sets the liquid from the nozzle based on the output detection signal. It is determined whether or not it has been discharged.

  In the cleaning operation of the above embodiment, the liquid supply source connected to the upstream side of the check valve 23 is changed to the ink cartridge by the switching operation of the valve body 36a of the switching valve 36 by the control signal output from the control unit 60. However, the present invention is not limited to this. For example, the user of the printer 11 may remove the ink cartridge 15 and install the cleaning liquid cartridge 35 in the cartridge holder 14, or conversely, remove the cleaning liquid cartridge 35 and install the ink cartridge 15. . In this case, the switching valve 36 is unnecessary, and the control unit 60 detects whether or not these processes have been completed by the user for the processes in steps S2 and S12 in the process flow shown in FIG. The determination process may be performed.

  -The process of step S7 in the washing | cleaning operation | movement in the said embodiment does not necessarily need to be implemented. For example, when the precipitate generated in the flow path portion 31b is washed away when the mixed liquid flows from the circulation flow path JF side to the downstream side, the carriage 20 does not need to reciprocate.

  In the above embodiment, the tube pump 40 causes the cleaning liquid to flow along with the ink in the circulation flow path JF in the same direction as the flow direction of the ink flowing through the ink supply tube 31 when supplying the ink to the liquid ejecting head 21. It may work. When the sediment 38 is diffused into the mixed liquid, the cleaning liquid does not necessarily flow in the reverse direction in the circulation flow path JF.

  In the above embodiment, the tube pump 40 flows the cleaning liquid that has flowed into the circulation flow path JF together with the ink in the circulation flow path JF at the same flow speed as that of the ink when only ink flows in the circulation flow path JF. You may make it make it. For example, when the difference in the diffusibility of the precipitate is small between the cleaning liquid and the ink, the same flow rate may be used.

  In the above embodiment, the configuration of the circulation channel JF that causes the cleaning liquid that diffuses the precipitate to flow at a high speed may be another configuration. A structure in which the cleaning liquid is circulated at a high speed and the cleaning liquid (mixed liquid) does not flow backward to the liquid supply source side, that is, the cleaning liquid, the ink, and the mixed liquid do not flow upstream of the check valve 23. As long as the liquid flow path is, the configuration of the circulation flow path JF may be adopted. Hereinafter, modified examples of the configuration of the circulation flow path JF will be described with reference to FIGS. 5A and 5B and FIGS. In FIGS. 5A, 5B, 6 and 7, the same reference numerals are given to the same components as those in the above embodiment, and the respective components such as the liquid flow paths and valves are simplified. (Symbolized).

  As shown in FIG. 5A, as a modified example of the circulation flow path JF, the ink supply tube 31 may not include the liquid reservoir 50. For example, even if the pulsation accompanying the operation of the tube pump 40 occurs when the liquid (mixed liquid) indicated by the broken line arrow Fk in the figure flows, it is precipitated by the mixed liquid flowing in the circulation flow path JF as in the above embodiment. In the case where an object can be diffused, the liquid reservoir 50 does not necessarily have to be provided in this way.

  Alternatively, as shown in FIG. 5B, the circulation channel JF of the above embodiment may include a sub-tank Ts that stores more liquid than the liquid reservoir 50 instead of the liquid reservoir 50. Good. In this case, the cleaning liquid or ink flowing from the upstream side of the check valve 23 passes through the upstream ink supply tube 31A of the ink supply tubes 31 divided into the upstream side and the downstream side, and is indicated by a solid arrow in the figure. As indicated by Fs, one end is accommodated in the sub tank Ts. Ink is supplied from the sub tank Ts to the liquid ejecting head 21 via the downstream ink supply tube 31B into which one end is inserted.

  Accordingly, the ink circulation tube 32 is formed such that one end of the ink circulation tube 32 is connected to the upstream ink supply tube 31A by the connection portion C1, and the other end is connected to the downstream ink supply tube 31B by the connection portion C2. As a result, the circulation flow path JF is formed by the sub tank Ts, the upstream ink supply tube 31A and the downstream ink supply tube 31B, and the ink circulation tube 32. As a result, along with the operation of the tube pump 40, as shown by a broken line arrow Fk in the figure, the upstream side ink supply tube into which the cleaning liquid and ink stored in the sub tank Ts or a mixed liquid thereof is inserted at one end respectively. 31A, the downstream ink supply tube 31B, and the ink circulation tube 32 can circulate and flow through the sub tank Ts.

  Further, as shown in FIG. 6, as another modification example of the circulation flow path JF, with respect to the downstream ink supply tube 31 </ b> B having one end inserted into the sub tank Ts and the other end connected to the pressure control valve 24. The other end of the ink circulation tube 32 having one end inserted into the sub tank Ts may be connected to the downstream ink supply tube 31B by the connection portion C2. That is, the circulation flow path JF includes a sub tank Ts that stores ink or cleaning liquid flowing in from the upstream ink supply tube 31A, and a downstream side that supplies ink from the sub tank Ts to the liquid ejecting head 21 as indicated by a solid arrow Fs in the figure. The ink supply tube 31B and the ink circulation tube 32 are formed. As a result, along with the operation of the tube pump 40 provided in the ink circulation tube 32, as shown by the broken line arrow Fk in the figure, the cleaning liquid and the ink stored in the sub tank Ts, or the mixed liquid thereof is supplied to the sub tank Ts. Circulate and flow through. In the present modification, the upstream ink supply tube 31A, the sub tank Ts, and the downstream ink supply tube 31B correspond to the first liquid flow path, and the sub tank Ts corresponds to the connection portion C1 in the above embodiment. To do.

  Alternatively, as shown in FIG. 7, as another modified example of the circulation flow path JF, an ink circulation tube 32 may be connected to the ink supply tube 31 by connection portions C1 and C2 inside the carriage 20. Good. That is, the circulation flow path JF is formed by the ink supply tube 31 and the ink circulation tube 32. As a result, in accordance with the operation of the tube pump 40 provided in the ink circulation tube 32, the flow direction of the ink supplied to the liquid ejecting head 21 (solid arrow Fs in the figure) and the flow direction as shown by the broken arrow Fk in the figure. Can circulate and flow cleaning liquid, ink, or a mixture thereof in the opposite direction.

  In the above embodiment, a plurality of liquid reservoirs 50 may be provided in the circulation flow path JF. In the above modification, one or more liquid reservoirs 50 may be provided in the circulation flow path JF shown in FIGS. 5B, 6, and 7. In the case where a plurality of liquid storage portions 50 are provided in the circulation flow path JF, they may be provided in both the ink supply tube 31 and the ink circulation tube 32.

  In the above embodiment, the circulation pump is not necessarily limited to the tube pump 40. For example, a diaphragm pump using a diaphragm and two check valves may be a circulation pump.

  In the above-described embodiment, the liquid storage unit 50 may be formed of a diaphragm in which the periphery of the displacement plate 53 is hermetically fixed. In this case, the diaphragm may be directly pressurized using air as a medium as the pressurizing unit 54 or may be pressurized via a pressure plate.

  In the above embodiment, the number of ink cartridges 15 is not limited to four, and may be more or less than four. In the printer 11, the liquid ejecting head 21 may not necessarily move in the scanning direction but may eject ink onto the paper S at a fixed position.

  In the above embodiment, the liquid ejecting apparatus may be a liquid ejecting apparatus that ejects or discharges liquid other than ink. Note that the state of the liquid ejected as a minute amount of liquid droplets from the liquid ejecting apparatus includes a granular shape, a tear shape, and a thread-like shape. The liquid here may be any material that can be ejected from the liquid ejecting apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ). Further, not only a liquid as one state of a substance but also a substance in which particles of a functional material made of a solid such as a pigment or a metal particle are dissolved, dispersed or mixed in a solvent is included. Typical examples of the liquid include ink and liquid crystal as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, or a color filter in a dispersed or dissolved form. There is a liquid ejecting apparatus for ejecting the liquid. Further, it may be a liquid ejecting apparatus that ejects a bio-organic matter used for biochip manufacturing, a liquid ejecting apparatus that ejects liquid as a sample that is used as a precision pipette, a printing apparatus, a micro dispenser, or the like. In addition, a transparent resin liquid such as UV curable resin is used to form a liquid injection device that injects lubricating oil pinpoint onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. May be a liquid ejecting apparatus that ejects the liquid onto the substrate. Further, it may be a liquid ejecting apparatus that ejects an etching solution such as acid or alkali in order to etch a substrate or the like.

  DESCRIPTION OF SYMBOLS 11 ... Printer as an example of a liquid ejecting apparatus, 21 ... Liquid ejecting head, 21a ... Nozzle, 23 ... Check valve, 24 ... Pressure control valve, 27 ... Liquid suction mechanism, 40 ... Tube pump as circulation pump, 50 ... Liquid reservoir, JF ... circulation channel.

Claims (6)

A liquid ejecting mechanism having a nozzle for ejecting liquid;
A liquid suction mechanism for discharging the liquid from the liquid ejection mechanism by suction of the liquid from the nozzle;
A first liquid flow path for supplying the liquid from the upstream side serving as the liquid supply source side to the liquid ejecting mechanism on the downstream side;
A second liquid channel connected to the first liquid channel and forming a circulation channel through which the liquid circulates with the first liquid channel;
A circulation pump that is provided in the second liquid flow path and operates to flow the liquid in the circulation flow path;
A liquid ejecting apparatus comprising: a liquid ejecting apparatus maintenance method for flushing the inside of the first liquid channel with a cleaning liquid,
In the state where the liquid of the supply source supplied to the first liquid channel is switched to the cleaning liquid, the switched cleaning liquid is discharged by suction by the liquid suction mechanism. Flowing into one liquid flow path and replacing at least a part of the liquid in the circulation flow path with the cleaning liquid;
Circulating the cleaning liquid replaced in the circulation channel in the circulation channel together with the liquid by the operation of the circulation pump, and mixing the liquid with the liquid;
A step of sucking the liquid mixture, in which the cleaning liquid and the liquid are mixed by the circulation, from the nozzle by the liquid suction mechanism and discharging the liquid from the liquid ejection mechanism;
A maintenance method for a liquid ejecting apparatus comprising: The maintenance method of the liquid ejecting apparatus according to claim 1,
A maintenance method for a liquid ejecting apparatus according to claim 1, wherein the circulation pump starts an operation after the cleaning liquid flows in more than a liquid amount corresponding to a half of a volume of the circulation flow path. In the maintenance method of the liquid ejecting device according to any one of claims 1 to 2,
A maintenance method for a liquid ejecting apparatus, wherein the circulation pump starts an operation after the cleaning liquid flowing into the first liquid flow path reaches the nozzle. In the maintenance method of the liquid ejecting device according to any one of claims 1 to 3,
The circulation pump flows the cleaning liquid together with the liquid in the circulation channel in a direction opposite to the flow direction of the liquid flowing in the first liquid channel when supplying the liquid to the liquid ejecting mechanism. A maintenance method for a liquid ejecting apparatus, characterized in that the liquid ejecting apparatus operates. In the maintenance method of the liquid ejecting apparatus according to any one of claims 1 to 4,
A maintenance method of a liquid ejecting apparatus, wherein the circulation channel is provided with at least one liquid storage part capable of storing the liquid. In the maintenance method of the liquid ejecting device according to any one of claims 1 to 5,
The circulation pump causes the cleaning liquid that has flowed into the circulation flow path to flow in the circulation flow path together with the liquid at a flow rate different from the flow speed of the liquid when the liquid flows in the circulation flow path. A maintenance method for a liquid ejecting apparatus.