JP2014076594A - Liquid jet device and maintenance method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jet device and a maintenance method therefor, which enable suppression of extraneous consumption of cleaning liquid in maintaining a cleaning device for suctioning liquid from a liquid jet head capable of jetting the liquid.SOLUTION: A printer includes: a liquid jet head 21 having a nozzle formed thereon, the nozzle capable of jetting ink; a maintenance device 30 enabled to clean the liquid jet head by a suction pump 41 suctioning inside a cap 32 abutting the liquid jet head 21 so as to surround the nozzle; a detection section 40 capable of detecting a flow volume of the liquid and a category thereof, the liquid suctioned by the suction pump; and a control section for controlling the liquid jet head on the basis of the detection result of the detection section. Further, in the case of the suctioned liquid being the ink of a flow volume equal to or less than a threshold flow volume, the control section controls in a manner so as to supply the cap with cleaning liquid, or, in the case of the suctioned liquid being air, supplies the cap with no cleaning liquid.

Description

  The present invention relates to a liquid ejecting apparatus including a cleaning device that forcibly sucks liquid from a liquid ejecting head capable of ejecting liquid, and a maintenance method thereof.

  Conventionally, as a kind of liquid ejecting apparatus, an ink jet printer that performs printing by ejecting ink (liquid) from a liquid ejecting head onto a sheet (target) is known. Some printers include a cleaning device for maintaining the liquid ejecting head. The cleaning device includes a cap that forms a sealed space in contact with the nozzle formation surface of the liquid ejecting head, and a suction device that forcibly sucks ink from the liquid ejecting head via the cap, and the viscosity is increased in the liquid ejecting head. The liquid ejecting head can be cleaned by forcibly sucking ink.

  However, when the cleaning frequency of the liquid ejecting head by the cleaning device decreases, the remaining ink may solidify and become clogged in the cap or the waste liquid tube that connects the cap and the suction device. When the cap or the waste liquid tube is clogged, the sealed space formed by the nozzle forming surface and the cap cannot be normally sucked by the suction device, and there is a possibility that a cleaning failure may occur.

  Therefore, in recent years, the amount of ink flowing in the waste liquid tube is detected, and when the ink amount is less than the threshold value, it is determined that the cap or the waste liquid tube is clogged, and the ink solidified material can be dissolved. A cleaning device that can supply a cleaning liquid into a cap has been developed (for example, Patent Document 1).

JP 2008-80209 A

  By the way, in the cleaning device provided in the liquid ejecting apparatus, when the cap is deformed due to swelling or the like by the ink component, it becomes impossible to form a sealed space between the cap and the nozzle forming surface. A defect (sealing defect) sometimes occurred.

  Therefore, in the above-described cleaning device, when the cap has a sealing failure with respect to the nozzle formation surface of the liquid jet head, the cap and the waste liquid tube flow through the waste liquid tube even though the cap and the waste liquid tube are not clogged. There is a possibility that the ink amount is less than the threshold value and the cleaning liquid is supplied into the cap to dissolve the ink solidified product. In such a case, no matter how much cleaning liquid is supplied, the sealing failure is not improved, and the cleaning liquid is wasted.

  Such a problem is generally common in liquid ejecting apparatuses that can supply cleaning liquid to a cleaning apparatus that forcibly sucks liquid from a liquid ejecting head that can eject liquid.

  The present invention has been made to solve such a problem, and an object of the present invention is to unnecessarily consume cleaning liquid when performing maintenance of a cleaning device that sucks liquid from a liquid ejecting head capable of ejecting liquid. An object of the present invention is to provide a liquid ejecting apparatus and a maintenance method thereof that can suppress this.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
In a liquid ejecting apparatus that solves the above problem, a suction unit sucks a liquid ejecting head in which a nozzle capable of ejecting liquid on a target is formed and a cap that is in contact with the liquid ejecting head so as to surround the nozzle. A cleaning device capable of cleaning the liquid ejecting head, a supply unit capable of supplying cleaning liquid to the cap, a detection unit capable of detecting the flow rate and type of the fluid sucked by the suction unit, and detection of the detection unit And a controller capable of controlling the drive of the supply unit based on a result, and the control unit drives the supply unit to the cap when the fluid is the liquid having a flow rate equal to or lower than a threshold flow rate. While supplying the cleaning liquid, the supply unit is not driven when the fluid is air.

  According to the above configuration, the cap is brought into contact with the liquid ejecting head to form a sealed space, and the suction unit sucks the inside of the cap so that the liquid is forcibly sucked from the nozzle of the liquid ejecting head. It can be performed. Further, when the detection unit detects that the sucked fluid is a liquid having a flow rate equal to or lower than the threshold flow rate at the time of cleaning, the control unit determines that clogging due to solidification of the liquid has occurred. Then, the cleaning liquid is supplied to the cap by driving the supply unit. On the other hand, when the detection unit detects that the sucked fluid is air, the control unit determines that the cap is not properly in contact with the liquid ejecting head and a sealed space cannot be formed, and the supply unit Does not drive. Accordingly, it is possible to suppress unnecessary consumption of the cleaning liquid when performing maintenance of the cleaning device that cleans the liquid ejecting head that can eject the liquid.

  The liquid ejecting apparatus further includes an informing unit capable of informing a state of the cleaning device, and the control unit informs the informing unit when the fluid sucked by the suction unit is air. It is desirable to notify.

  According to the above configuration, when the suction unit sucks air during cleaning, the control unit notifies the notification unit that the cap is not properly in contact with the liquid ejecting head and seals Notify that it is defective. As a result, it is possible to take cap replacement work and the like based on such notification results.

  The liquid ejecting apparatus includes: a plurality of caps that can contact the liquid ejecting head so as to surround the nozzle; and a plurality of caps that contact the liquid ejecting head so as to surround the nozzle to be cleaned. A switching mechanism that can be switched from among the caps, and when the fluid sucked by the suction unit is air, the control unit drives the switching mechanism to the liquid ejecting head. It is desirable that the cap to be contacted is switched to another cap, and the cap sucked by the suction portion is the other cap.

  According to the above configuration, since the cap is configured to include a plurality of caps, when a certain cap is deformed or the like, it becomes impossible to normally contact the liquid ejecting head so as to surround the nozzle to be cleaned. The nozzle to be cleaned can be cleaned by driving the switching mechanism and using another cap.

In the liquid ejecting apparatus, it is preferable that the plurality of caps are provided so as to partition a nozzle forming surface on which the nozzle is formed in the liquid ejecting head.
According to the above configuration, the plurality of caps can be arranged so as to be within the surface area of the nozzle formation surface in a plan view in a direction intersecting the nozzle formation surface. According to this, even if a plurality of caps are provided, the cleaning device can be configured compactly.

In the liquid ejecting apparatus, it is preferable that the supply unit is a cleaning liquid ejecting nozzle formed in the liquid ejecting head, similarly to the nozzle capable of ejecting the liquid.
According to the above configuration, the cleaning liquid can be ejected from the cleaning liquid ejecting nozzle formed in the same manner as the nozzle that ejects the liquid. Thus, the cleaning liquid can be supplied to the cap and the fluid flow path with a simple and compact configuration.

  In addition, a maintenance method for a liquid ejecting apparatus that solves the above problems includes a liquid ejecting head in which a nozzle capable of ejecting liquid on a target is formed, and a cap that is in contact with the liquid ejecting head so as to surround the nozzle. A maintenance method for a liquid ejecting apparatus, comprising: a cleaning device capable of cleaning the liquid ejecting head by suction by a portion; and a supply unit capable of supplying a cleaning liquid to the cap, wherein the suction is sucked by the suction portion Based on the detection step for detecting the flow rate and type of fluid, and the detection result of the detection step, when it is determined that the fluid is the liquid having a flow rate equal to or lower than a threshold flow rate, the supply unit is driven to While the supply step of supplying the cleaning liquid to the cap is performed, when it is determined that the fluid is air, the supply step is performed. And a determination step not to implement.

  According to the above configuration, it is possible to obtain the same operational effects as the operational effects of the liquid ejecting apparatus described above.

FIG. 2 is a perspective view illustrating a schematic configuration of a printer. FIG. 3 is a front view illustrating a schematic configuration of a liquid ejecting head included in the printer. FIG. 3 is a front view illustrating a schematic configuration of a maintenance device provided in the printer. The top view which shows schematic structure of the cap with which a maintenance apparatus is provided. FIG. 3 is a block diagram illustrating an electrical configuration relating to a cleaning operation of the printer. 6 is a flowchart according to a cleaning operation process performed by a control unit of the printer. FIG. 6 is a front view illustrating a positional relationship between a liquid ejecting head and a cap during cleaning. FIG. 6 is a front view illustrating a positional relationship between a liquid ejecting head and a cap after driving a switching mechanism. FIG. 6 is a front view illustrating a positional relationship between a liquid ejecting head and a cap during cleaning after the cap is switched. The front view which shows schematic structure of the switching mechanism of a modification. FIG. 9 is a front view illustrating a positional relationship between a liquid ejecting head and a cap after driving a switching mechanism according to a modification. It is a figure which shows the modification of a detection part, Comprising: (a) is the schematic of a seal | sticker defect generation state, (b) is the schematic of the clogging generation | occurrence | production state. It is a figure which shows the other modification of a detection part, Comprising: (a) is a schematic diagram of the occurrence state at the time of a seal defect, (b) is a schematic diagram of the clogging occurrence state.

Hereinafter, an embodiment in which a liquid ejecting apparatus is embodied in an ink jet printer will be described with reference to the drawings.
As shown in FIG. 1, a support member 13 for supporting a sheet P as an example of a target at the time of recording extends along the longitudinal direction at the lower part in a frame 12 having a substantially rectangular box shape in the printer 11. Has been. Then, the paper P is fed onto the support member 13 by a paper feed roller 14 provided at the lower back of the frame 12.

  A guide shaft 15 is installed above the support member 13 in the frame 12 along the longitudinal direction of the support member 13. A carriage 16 is supported on the guide shaft 15 so as to be capable of reciprocating along the axial direction. That is, a support hole 16 a is formed in the carriage 16 so as to penetrate in the axial direction of the guide shaft 15, and the guide shaft 15 is inserted into the support hole 16 a, so that the carriage 16 is in the axial direction of the guide shaft 15. It is supported so that it can reciprocate.

  A driving pulley 17 and a driven pulley 18 are rotatably supported at positions corresponding to both end portions of the guide shaft 15 on the inner surface of the wall portion on the back side of the frame 12. An output shaft of a carriage motor 19 serving as a drive source when the carriage 16 is reciprocally moved is connected to the drive pulley 17, and an endless shape in which a part is connected to the carriage 16 between the pair of pulleys 17 and 18. The timing belt 20 is hung. Accordingly, the carriage 16 is moved in the axial direction of the guide shaft 15 via the endless timing belt 20 by the driving force of the carriage motor 19 while being guided by the guide shaft 15.

  As shown in FIGS. 1 and 2, a liquid ejecting head 21 having a nozzle forming surface 21 a on which a nozzle 22 capable of ejecting ink is formed is provided on the lower surface side of the carriage 16. On the other hand, an ink cartridge 23 for supplying ink to the liquid ejecting head 21 is detachably mounted on the carriage 16.

  As shown in FIG. 2, in this embodiment, ink cartridges 23 (23C, 23M, 23Y, and 23K (23C to 23K)) for four colors are provided, and the liquid ejecting head 21 has a number corresponding to the ink cartridges 23. Nozzle 22 (22C-22K) is formed. Further, the ink in the ink cartridge 23 is transferred from the ink cartridge 23 to the liquid ejecting head 21 via the first flow path 24 (24C to 24K) as a piezoelectric element (not shown) provided in the liquid ejecting head 21 is driven. Supplied to. The supplied ink flows through the switching valve 25 (25C to 25K) and the second flow path 26 (26C to 26K) and is fed from the nozzles 22 of the liquid ejecting head 21 onto the support member 13. Printing is performed by being ejected onto the paper P.

  Further, as shown in FIG. 2, the switching valve 25 connecting the first flow path 24 and the second flow path 26 is thickened or solidified via the third flow path 27 (27C to 27K). A cleaning liquid storage tank 28 for storing a cleaning liquid for dissolving and cleaning the ink is connected. The switching valve 25 can select any one of the first flow path 24 and the third flow path 27 and connect the flow path to the second flow path 26 communicating with the nozzle 22. It is said. Thus, in the printer 11 of the present embodiment, by switching the switching valve 25, it is possible to eject ink from the nozzles 22 of the liquid ejecting head 21 or eject cleaning liquid. That is, in the present embodiment, the nozzle 22 is an example of a supply unit that supplies the cleaning liquid into the cap 32 and also an example of the cleaning liquid injection nozzle.

  As shown in FIG. 1, in the movement area of the carriage 16, the outer position of the printing area that ejects ink onto the paper P is a home position HP where the carriage 16 waits during non-printing. The home position HP is provided with a maintenance device 30 (an example of a cleaning device) for performing maintenance such as cleaning of the liquid jet head 21.

  In addition, a notification unit 29 that displays an error message when an abnormality occurs in the printer 11 is provided on the frame 12 on the home position HP side in the movement direction of the carriage 16 and on the conveyance direction side of the paper P. . For example, the notification unit 29 can display information indicating whether or not the liquid jet head 21 is normally cleaned.

  Next, the maintenance device 30 will be described. In FIG. 3 showing the schematic configuration of the maintenance device 30, only a part of the configuration is shown in a cross-sectional view for the sake of simplicity. Further, in the drawings after FIG. 3, in order to simplify the drawing, comprehensive symbols may be omitted for members having a plurality of similar configurations such as the nozzles 22 (22 </ b> C to 22 </ b> K).

  As shown in FIGS. 3 and 4, the maintenance device 30 has a substantially rectangular plate-like cap support portion 31 in plan view, and a substantially square box shape with a bottom that is open on the cap support portion 31 from above. A plurality (four in this embodiment) of caps 32 (32C to 32K) are provided. That is, on the cap support portion 31, the number of caps 32 (32 </ b> C to 32 </ b> K) corresponding to the number of rows of nozzles 22 corresponds to the rows of nozzles 22 formed on the nozzle formation surface 21 a. It is provided in parallel so as to partition. The cap 32 is made of an elastomer such as elastically deformable rubber or resin. The cap 32 is a sealed space between the nozzle forming surface 21 a of the liquid ejecting head 21 and the nozzle forming surface 21 a based on driving of an elevating mechanism 34 provided on the side of the cap support portion 31. It is possible to move between the abutting position that abuts so as to form and the retracted position that is retracted downward from the nozzle forming surface 21a.

  In the cap support portion 31, communication holes 35 (35 </ b> C to 35 </ b> K) that allow the inside of the cap 32 to communicate with the lower portion of the cap support portion 31 are formed at the center position of each cap 32 in plan view. The communication hole 35 is provided for discharging ink or the like ejected from the nozzle 22 of the liquid ejecting head 21 to the outside of the cap 32. Further, the upstream end of a branch tube 37 (37C to 37K) for connecting the inside of the cap 32 and the waste liquid tank 36 installed below the home position HP is connected to the communication hole 35. Here, the upstream side and the downstream side are distinguished according to the flow of fluid including ink flowing through the branch tube 37.

  As shown in FIG. 3, the branch tube 37 is allowed or restricted to flow a fluid such as ink or air through the branch tube 37 at a position downstream from the upstream end connected to the communication hole 35. A gate valve 38 (38C to 38K) is provided. Each gate valve 38 can be opened / closed independently by electrical control, and the ink flow in the branch tube 37 can be individually controlled by this opening / closing operation. That is, while the gate valve 38 is open, fluid such as ink or air is allowed to flow, while when the gate valve 38 is closed, fluid is restricted. Further, in each branch tube 37, a junction tube 39 is configured by joining each branch tube 37 at a position downstream from the gate valve 38.

  The joining tube 39 can detect the flow rate of the fluid flowing through the joining tube 39 and whether the fluid is ink or air at a position downstream from the upstream end connected to the branch tube 37. A detection unit 40 is provided. Specific examples of the detection unit 40 include a mass flow meter that measures the mass flow rate of the fluid, and a transmission laser sensor that estimates the type of fluid from the turbidity of the fluid. Further, in the merging tube 39, a suction pump 41 as an example of a suction unit capable of sucking the cap 32 through the branch tube 37 and the merging tube 39 is provided at a position downstream from the detection unit 40. In the present embodiment, any one or all caps 32 can be sucked by one suction pump 41 and four gate valves 38. That is, it is possible to select the cap 32 that the suction pump 41 sucks from among the caps 32.

  Further, the most downstream end of the merging tube 39 is drawn into a waste liquid tank 36 installed at a position below the home position HP. In addition, on the bottom surface of the waste liquid tank 36, for example, an ink absorbing material 42 that suppresses leakage of stored waste liquid from the waste liquid tank 36 when the printer 11 is tilted is disposed.

  Thus, in the present embodiment, a maintenance device (cleaning device) 30 capable of cleaning the liquid ejecting head 21 is configured by the suction pump 41 sucking the cap 32 in contact with the nozzle forming surface 21a of the liquid ejecting head 21. Has been.

  As shown in FIGS. 3 and 4, the cap support portion 31 has a substantially central position in a plan view of the cap support portion 31, with an axis extending in a direction orthogonal to the nozzle forming surface 21 a of the liquid ejecting head 21 as a rotation axis. A switching mechanism 43 is provided that can rotate 31 in both forward and reverse directions. That is, the switching mechanism 43 of the present embodiment rotates the cap support portion 31 in the direction of the arrow indicated by the two-dot chain line in FIG. It is possible to switch to 32. As an example, the switching mechanism 43 can switch the cap 32K facing the nozzle 22K to another cap 32C. In this case, the elevating mechanism 34 is also configured to rotate together with the cap support portion 31 that supports each cap 32.

Next, the electrical configuration of the printer 11 will be described.
As shown in FIG. 5, the printer 11 includes a control unit 44 that performs overall control of the entire apparatus. The liquid jet head 21, the switching valve 25, the notification unit 29, the lifting mechanism 34, the gate valve 38, the detection unit 40, the suction pump 41, and the switching mechanism 43 are connected to the interface provided in the control unit 44. And the control part 44 can be communicated unidirectionally or bidirectionally with respect to each of these components.

  Next, a process flow of the cleaning operation of the liquid ejecting head 21 performed by the control unit 44 of the printer 11 will be described. Here, the following description will be made assuming that the carriage 16 is already in the home position HP. For simplification of description, a processing flow of the control unit 44 in the case where cleaning is performed using the nozzle 22K of the liquid jet head 21 as a cleaning target will be described. In the process shown in FIG. 6, for steps S100 to S117 to be processed after passing through steps S116 to S121 (driving the switching mechanism 43), the cap 32K in the description of steps S100 to S117 is replaced with the cap 32C. Shall.

  As shown in FIG. 6, in step S100, the control unit 44 initializes a variable FLG to 0. The variable FLG being 0 means that the switching mechanism 43 of the cap 32 has not been driven yet in the processing flow shown in FIG. Then, when the initialization of the variable FLG is finished, the control unit 44 proceeds to step S101.

  In step S <b> 101, the control unit 44 drives the elevating mechanism 34 to raise the cap 32, thereby bringing the cap 32 into contact with the nozzle forming surface 21 a of the liquid ejecting head 21. Then, as shown in FIG. 7, when the cap 32 has moved to the contact position, the control unit 44 proceeds to step S102.

  In step S <b> 102, the control unit 44 drives the suction pump 41 in order to suck ink from the nozzles 22 </ b> K of the liquid ejecting head 21. At this time, when the gate valve 38K of the branch tube 37K corresponding to the nozzle 22K to be cleaned is in the closed state, the gate valve 38K is opened before the suction pump 41 is driven. Thus, the gate valve 38K is operated by the control unit 44. When the suction pump 41 is driven, the control unit 44 proceeds to step S103.

  In step S <b> 103 (detection step), the control unit 44 causes the detection unit 40 to detect the flow rate and type of fluid flowing through the merging tube 39 by driving the suction pump 41. When the detection by the detection unit 40 ends, the control unit 44 proceeds to step S104.

  In step S104 (determination step), the control unit 44 determines whether or not the fluid flowing through the merging tube 39 is ink from the detection result of the detection unit 40 in step S103. If the fluid flowing through the merging tube 39 is ink (step S104 = YES), the control unit 44 proceeds to step S105.

  In step S105 (determination step), the control unit 44 determines whether or not the flow rate of the ink (fluid) flowing through the merging tube 39 from the detection result of the detection unit 40 in step S103 is larger than a preset threshold flow rate. Make a decision. When the threshold flow rate is set to “0 (zero)”, it is determined that clogging has occurred only when no ink flows through the merge tube 39, and thus a value larger than “0 (zero)” is used. It is desirable. Further, since the threshold flow rate depends on the output of the suction pump 41, the flow path cross-sectional area of the merging tube 39, and the like, it is desirable that the threshold flow rate be determined in advance through experiments. When the flow rate of the ink flowing through the merge tube 39 is equal to or higher than the threshold flow rate (step S105 = YES), the control unit 44 shifts the process to step S106.

  In step S106, based on the determination results in steps S104 and S105, the control unit 44 determines that the cleaning operation is normally performed because the ink that exceeds the threshold flow rate flows in the merging tube 39. Then, it waits for a predetermined time t1 (for example, several seconds) determined to suck (clean) an appropriate amount of ink from the nozzle 22K of the liquid jet head 21. As a result, even if there is ink or bubbles thickened in the nozzle 22K, the first flow path 24K, and the second flow path 26K of the liquid ejecting head 21, the ink or bubbles are forcibly sucked from the nozzle 22K. It becomes possible to do. Then, when the predetermined time t1 for cleaning has elapsed, the control unit 44 proceeds to step S107.

  In step S107, the control unit 44 stops the suction pump 41 when the cleaning operation is completed. When the suction pump 41 is stopped, the control unit 44 proceeds to step S108.

  In step S108, the control unit 44 opens the space to the atmosphere in order to make the inside of the cap 32K, which is in a negative pressure, atmospheric pressure. When the inside of the cap 32K returns to the atmospheric pressure, the control unit 44 proceeds to step S109.

  In step S109, the control unit 44 drives the lifting mechanism 34 to retract (lower) the cap 32. As shown in FIG. 3, when the cap 32 moves to the retracted position, the control unit 44 ends the process.

  On the other hand, when the flow rate of the ink (fluid) flowing through the merging tube 39 is not equal to or higher than the threshold flow rate in the previous step S105 (step S105 = NO), the control unit 44 shifts the process to step S110.

  In step S110, the controller 44 determines that somewhere in the flow path from the cap 32K to the suction pump 41 because only the amount of ink that is less than the threshold flow rate flows in the merge tube 39 based on the determination results in steps S104 and S105. Thus, it is determined that clogging due to the solidified ink has occurred. Then, the controller 44 performs the following steps in order to derive a cleaning liquid in order to remove the ink solidified product. First, in step S110, the control unit 44 stops the suction pump 41. When the suction pump 41 is stopped, the control unit 44 proceeds to step S111.

  In step S111, the control unit 44 opens the space to the atmosphere in order to make the inside of the cap 32K in a negative pressure atmospheric pressure. When the inside of the cap 32K returns to the atmospheric pressure, the control unit 44 proceeds to step S112.

  In step S112, the control unit 44 informs the notification unit 29 that clogging has occurred somewhere in the flow path from the cap 32K to the suction pump 41. If the alerting | reporting part 29 is made to alert | report, the control part 44 will transfer the process to step S113.

  In step S113 (supply step), the control unit 44 operates the switching valve 25K to set the flow path communicating with the nozzle 22K and the second flow path 26K in order to eject the cleaning liquid from the nozzle 22K of the liquid jet head 21. The first flow path 24K is switched to the third flow path 27K. Thus, the control unit 44 drives the piezoelectric element to spray the cleaning liquid into the cap 32K in a state where the cleaning liquid storage tank 28 and the nozzle 22K are in communication. Note that the spray of the cleaning liquid may be performed on the cap positioned at the retracted position illustrated in FIG. When the cleaning liquid is sprayed onto the cap 32K, the control unit 44 proceeds to step S114.

  In step S <b> 114, the control unit 44 waits for a predetermined time t <b> 2 (for example, 30 seconds) necessary for the ink solidified product to be dissolved by the cleaning liquid discharged to the cap 32. It is desirable that the predetermined time t2 is determined in advance by performing an experiment or the like to determine how much time the solidified ink can be removed. Further, during the elapse of the predetermined time t2, the control unit 44 operates the switching valve 25K to change the flow path communicating with the nozzle 22K and the second flow path 26K from the third flow path 27K to the first flow path 24K. Switch. And if it waits for predetermined time t2, the control part 44 will transfer the process to step S115.

  In step S115, the control unit 44 drives the suction pump 41 to suck ink from the nozzles 22K of the liquid jet head 21. When the suction pump 41 is driven, the control unit 44 proceeds to step S106.

  By the way, when the fluid flowing through the merging tube 39 is not ink in the previous step S104 (step S104 = NO), that is, when it is air, the control unit 44 shifts the process to step S116.

  In step S116, based on the determination result in step S104, the control unit 44 does not flow ink into the merging tube 39, that is, air flows, so the cap 32K is connected to the nozzle forming surface 21a of the liquid ejecting head 21. It is determined that a seal failure has occurred. As a cause of the sealing failure, in this embodiment, it is considered that the cap 32K itself has a problem because the cap 32K is swollen or deformed by the solvent in the ink. For this reason, the control unit 44 performs the following steps in order to perform cleaning by replacing the cap 32K provided corresponding to the target nozzle 22K with another one. First, in step S116, as a result, the suction pump 41 performing the idle suction is stopped. If the suction pump 41 is stopped, the control unit 44 proceeds to step S117.

  In step S117, the control unit 44 determines whether or not the value of the variable FLG is zero. If the value of the variable FLG is 0 (step S117 = YES), the control unit 44 shifts the process to step S118.

  In step S <b> 118, the control unit 44 notifies the notification unit 29 that a seal failure has occurred when the cap 32 is brought into contact with the nozzle formation surface 21 a of the liquid jet head 21. If the alerting | reporting part 29 is made to alert | report, the control part 44 will transfer the process to step S119.

  In step S119, the control unit 44 drives the elevating mechanism 34 to retract the cap 32. As shown in FIG. 3, when the cap 32 moves to the retracted position, the control unit 44 proceeds to step S120.

  In step S120, the control unit 44 drives the switching mechanism 43 to rotate the cap support unit 31 by an arbitrary angle (180 degrees in the present embodiment) as indicated by an arrow line in FIG. For example, when the cap support portion 31 is rotated 180 degrees, the cap 32 supported by the cap support portion 31 is arranged as shown in FIG. 8 with respect to the nozzle forming surface 21 a of the liquid jet head 21. That is, it is not the cap 32K that has caused the sealing failure but the other cap 32C that faces the nozzle 22K to be cleaned. Thus, if the cap support part 31 is rotated, the control part 44 will transfer the process to step S121.

  In step S121, the control unit 44 substitutes 1 for the variable FLG. The variable FLG being 1 means that the switching mechanism 43 is driven to rotate the cap support portion 31 in the flowchart shown in FIG. When the assignment of the value to the variable FLG is finished, the control unit 44 proceeds to step S101.

  By the way, in the previous step S117, when the value of the variable FLG is 1 (step S117 = NO), the control unit 44 shifts the process to step S122. In step S122, the control unit 44 makes the following determination based on the determination results in steps S104 and S117. That is, in order to clean the nozzle 22K, the cap 32K is positioned at the contact position and the suction pump 41 is driven, but a sealing failure has occurred. For this reason, the switching mechanism 43 is driven to switch the cap 32K that has caused the sealing failure to the normal cap 32C (FLG = 1), but the sealing failure has occurred in the cap 32C after the switching. Therefore, when the switching mechanism 43 is driven again and the cap 32C is switched to the cap 32K, it is predicted that the sealing failure will not be improved, and it is determined that the nozzle 22K cannot be cleaned. For this reason, in step S122, the control unit 44 notifies the notification unit 29 that cleaning cannot be performed and that the cap 32 is urged to be replaced. Note that the variable FLG is initialized in the flowchart shown in FIG. 6 because the deformation of the cap 32 can be recovered over time due to the viscoelastic characteristics of the cap 32 when the next cleaning operation is performed. It is because there is sex. If the alerting | reporting part 29 is made to alert | report, the control part 44 will transfer the process to step S109.

  Next, the operation of the printer 11 will be described by focusing on the cleaning operation performed by the maintenance device 30. In the following description, as in the description of the flowchart shown in FIG. 6, the cleaning operation of the nozzle 22 </ b> K will be described for the sake of simplification, but the same operation is performed for the other nozzles 22 </ b> C, 22 </ b> M, and 22 </ b> Y. It is possible to obtain

When cleaning the liquid jet head 21, the carriage 16 is moved to the home position HP facing the maintenance device 30 as shown in FIG. 3.
As shown in FIG. 7, the elevating mechanism 34 is driven to bring the cap 32 into contact with the nozzle forming surface 21a of the liquid ejecting head 21, and the suction pump 41 is driven to drive ink from the nozzle 22K to be cleaned. The suction is forcibly performed (step S106). Thereby, it is possible to remove the thickened ink and bubbles from the nozzle 22K and the first flow path 24K and the second flow path 26K communicating with the nozzle 22K. Then, when the ink suction is finished, the suction pump 41 is stopped, the lifting mechanism 34 is driven, and the cap 32 is lowered. Thus, the cleaning operation of the liquid jet head 21 by the maintenance device 30 is completed.

  On the other hand, even if the suction pump 41 is driven, the flow from the cap 32K to the suction pump 41 when the sucked ink amount is small or the ink does not flow in the merging tube 39 (step S105 = NO). In order to eliminate clogging caused by the ink solidified material occurring somewhere in the path, the cleaning liquid is discharged from the nozzle 22K into the cap 32K. The discharge of the cleaning liquid is temporarily switched from the first flow path 24K communicating with the ink cartridge 23K to the third flow path 27K communicating with the cleaning liquid storage tank 28 from the flow path where the switching valve 25K communicates with the nozzle 22K. Done in When the clogging is eliminated, the target nozzle 22K is cleaned again (step S106). Thus, even if clogging occurs anywhere in the flow path from the cap 32K to the suction pump 41, the cleaning operation is appropriately performed by eliminating the clogging with the cleaning liquid.

  Further, when the suction pump 41 is driven and the ink cannot be sucked and the air is flowing (step S104 = NO), the cap 32K is switched in order to eliminate the sealing failure due to the deformation of the cap 32K. Is done. In switching the cap 32K, first, the elevating mechanism 34 is driven to move the cap 32 from the contact position shown in FIG. 7 to the retracted position shown in FIG.

  Then, as shown in FIGS. 8 and 9, the switching mechanism 43 is driven to rotate the cap support 31 by 180 degrees, and the elevating mechanism 34 is driven again to move the cap 32 to the contact position. When the cap 32 is located at the contact position, the suction pump 41 is driven to forcibly suck ink from the nozzles 22K to be cleaned. Thus, even when a defect such as deformation of the cap 32K occurs and a seal failure occurs, the cleaning operation is appropriately performed by switching the cap 32K to another cap 32C.

According to the above embodiment, the following effects can be obtained.
(1) The cap 32 is brought into contact with the liquid ejecting head 21 to form a sealed space, and the suction pump 41 sucks the cap 32 to forcibly suck ink from the nozzles 22 of the liquid ejecting head 21. So-called cleaning can be performed. In addition, when the detection unit 40 detects that the sucked fluid is an ink having a flow rate equal to or lower than the threshold flow rate at the time of cleaning, the control unit 44 indicates that clogging due to ink solidification has occurred. After the determination, the cleaning liquid is supplied from the nozzle 22 to the cap 32. On the other hand, when the detection unit 40 detects that the sucked fluid is air, the control unit 44 determines that the cap 32 is not normally in contact with the liquid ejecting head 21 and a sealed space cannot be formed. Thus, the cleaning liquid is not supplied into the cap 32. Accordingly, it is possible to suppress unnecessary consumption of the cleaning liquid when performing maintenance of the maintenance device 30 that cleans the liquid ejecting head 21 that can eject ink.

  (2) When performing the cleaning, if the suction pump 41 sucks air, the control unit 44 can notify the notification unit 29, that is, the cap 32 can normally contact the liquid jet head 21. Notify that the seal is defective. As a result, the user of the printer 11 can take a cap 32 replacement operation or the like based on the notification result.

  (3) Since the configuration includes a plurality of caps 32, when a certain cap 32 is deformed or the like and cannot normally contact the liquid ejecting head 21, the switching mechanism 43 is driven and the other caps 32 are driven. The liquid jet head 21 can be cleaned by using.

  (4) Since the plurality of caps 32 are arranged so as to be within the surface area of the nozzle forming surface 21a in a plan view in the direction intersecting the nozzle forming surface 21a, the maintenance device 30 is compact even if a plurality of caps 32 are provided. Can be configured.

  (5) Since the cleaning liquid can be ejected from the nozzle 22 that ejects the ink, for example, compared with a case where a supply device for newly supplying the cleaning liquid is provided, the cleaning liquid is capped with a simple and compact configuration. Can be supplied to.

In addition, you may change the said embodiment into the modification shown below. Moreover, you may combine each modification with each other.
In the above embodiment, the switching mechanism 43 may be a switching mechanism 50 that moves the cap support portion 31 in a direction along the nozzle forming surface 21a, as shown in FIGS. Specifically, as shown in FIGS. 10 and 11, the switching mechanism 50 has a pinion 52 pivotally supported on a rotation shaft 51 a of a motor 51 that can rotate forward and reverse, and the pinion 52 is connected to a side portion of the cap support portion 31. You may comprise by engaging with the rack 53 formed in this. According to this, the cap 32 supported by the cap support part 31 can be reciprocated in the direction along the nozzle forming surface 21a by driving the motor 51 forward and reverse. That is, by driving the switching mechanism 50 and moving the cap support portion 31 to the position of the two-dot chain line shown in FIG. 10, the cap 32M facing the nozzle 22M can be used as the cap 32K as shown in FIG. .

  Further, by providing the rack 53 long in the moving direction of the cap support portion 31, it is possible to make a configuration in which a plurality of caps 32 can be brought into contact with a certain nozzle 22. For example, a configuration in which a plurality of caps 32C, 32M, 32Y, and 32K can be brought into contact with the nozzle 22K can be employed.

  In the above embodiment, as shown in FIGS. 12 and 13, the detection unit 40 detects the deformation amount and the deflection amount of the merging tube 39, so that the normal cleaning state and the deformation of the cap 32 at the time of cleaning are performed. It is also possible to detect the state of occurrence of a sealing failure due to, for example, and the state of occurrence of clogging due to solidified ink.

  First, as shown in FIG. 12 (a), a flow path portion 39A having a lower elastic modulus than that of the merge tube 39 is provided in a part of the merge tube 39, and according to the fluid flowing through the flow path portion 39A and the flow rate. Alternatively, the flow rate and type of the fluid may be detected from the deformation amounts of the different flow path portions 39A. According to this, in the seal failure occurrence state, since the pressure change in the merging tube 39 is small compared to the non-suction state, the deformation amount of the flow path portion 39A is small as shown in FIG. On the other hand, in the clogged state, a negative pressure is generated in the merge tube 39, so that the flow path portion 39A is greatly compressed and deformed as shown in FIG. In the normal cleaning state, ink is sucked before the negative pressure in the clogging state is reached, so the negative pressure at that time is lower than that in the clogging state, and the amount of compressive deformation of the flow path portion 39A is as shown in FIG. The deformation amount is intermediate between the deformation amount shown in a) and the deformation amount shown in FIG. And each state can be distinguished and detected by detecting the deformation | transformation amount of the flow-path part 39A which changes according to each state at the time of a cleaning with a strain sensor or a laser displacement meter. In the modification of the detection unit 40 described above, each state at the time of cleaning may be detected by detecting the deformation amount of the joining tube 39 itself without providing the flow path portion 39A.

  Further, as shown in FIGS. 13A and 13B, the merging tube 39 is provided with a deflection in advance, and each state is determined based on the deflection amount of the merging tube 39 which varies depending on each state during cleaning. It may be detected separately. According to this, as in the modified example shown in FIG. 12, the amount of deflection of the merging tube 39 is small as shown in FIG. 13 (a) in the state of poor seal occurrence, and as shown in FIG. 13 (b) in the state of clogging. The amount of deflection of the junction tube 39 increases. The reason why the deflection is given in advance is to make it easy to make a difference in the deflection amount of the merging tube 39 that differs depending on each state.

  Thus, by detecting each state at the time of cleaning based on the deformation amount and the deflection amount of the merging tube 39 and the flow path portion 39A, the detection unit 40 can be configured at a lower cost.

  In the above embodiment, the nozzles 22 that eject ink and the nozzles that eject cleaning liquid may be provided separately. Further, the cleaning liquid may be introduced into the cap 32 from the side wall portion of the cap 32 or the like instead of being ejected from the liquid ejecting head 21.

  In the above embodiment, the cap 32 may not be provided so as to partition the nozzle forming surface 21a. That is, the plurality of caps 32 may not be arranged so as to be within the surface area of the nozzle forming surface 21a in a plan view in the direction intersecting with the nozzle forming surface 21a.

-In above-mentioned embodiment, when it judges that the control part 44 is a seal | sticker defect (step S104 = NO), you may notify only that without switching the cap 32. FIG.
In the above embodiment, the maintenance device 30 may include the detection unit 40 and the suction pump 41 for each branch tube 37. In this case, the junction tube 39 and the gate valve 38 may be omitted.

-In above-mentioned embodiment, you may alert | report the alerting | reporting part 29 by an error sound. Further, the notification unit 29 may be omitted.
In the above embodiment, the shape of the nozzle forming surface 21a of the liquid jet head 21 may not be a square such as a rectangle. In this case, it is desirable that the cap 32 and the cap support portion 31 have a shape corresponding to the shape of the nozzle forming surface 21a.

  In the above embodiment, the control unit 44 may move the process to step S103 after driving the suction pump in step S115. According to this, even if the ink solidified product cannot be completely removed by ejecting the cleaning liquid once, the possibility of removing the ink solidified by ejecting the cleaning liquid a plurality of times can be increased.

  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, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil 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 (an example of a liquid ejecting apparatus), 22 (22C-22K) ... Nozzle (an example of a washing | cleaning liquid ejection nozzle, an example of a supply part), 21 ... Liquid ejecting head, 21a ... Nozzle formation surface, 29 ... Notification part, 30 ... maintenance device (cleaning device), 32 (32C to 32K) ... cap, 40 ... detection unit, 41 ... suction pump (an example of suction unit), 43, 50 ... switching mechanism, 44 ... control unit, P ... paper (target) ), S103 ... detection step, S104, S105 ... determination step, S113 ... supply step.

Claims (6)

A liquid ejecting head in which a nozzle capable of ejecting liquid to a target is formed;
A cleaning device capable of cleaning the liquid ejecting head by sucking the inside of the cap in contact with the liquid ejecting head so as to surround the nozzle;
A supply unit capable of supplying a cleaning liquid to the cap;
A detection unit capable of detecting the flow rate and type of fluid sucked by the suction unit;
A control unit capable of controlling the drive of the supply unit based on the detection result of the detection unit,
The control unit drives the supply unit to supply the cleaning liquid to the cap when the fluid is the liquid having a flow rate equal to or lower than a threshold flow rate, while the supply unit supplies the cleaning liquid to the cap. The liquid ejecting apparatus is characterized by not driving. A notification unit capable of notifying the state of the cleaning device;
The liquid ejecting apparatus according to claim 1, wherein when the fluid sucked by the suction unit is air, the control unit causes the notification unit to notify that effect. A plurality of caps capable of contacting the liquid jet head so as to surround the nozzle;
A switching mechanism capable of switching a cap to be brought into contact with the liquid jet head so as to surround the nozzle to be cleaned from the plurality of caps,
When the fluid sucked by the suction unit is air, the control unit switches the cap that contacts the liquid ejecting head by driving the switching mechanism, and the suction unit performs suction. The liquid ejecting apparatus according to claim 1, wherein the cap to be used is the another cap.   The liquid ejecting apparatus according to claim 3, wherein the plurality of caps are provided so as to partition a nozzle forming surface on which the nozzle is formed in the liquid ejecting head.   The said supply part is the washing | cleaning liquid injection nozzle formed in the said liquid jet head similarly to the said nozzle which can eject the said liquid, The Claim 1 characterized by the above-mentioned. Liquid ejector. A liquid ejecting head in which a nozzle capable of ejecting liquid to a target is formed;
A cleaning device capable of cleaning the liquid ejecting head by sucking the inside of the cap in contact with the liquid ejecting head so as to surround the nozzle;
A supply unit capable of supplying a cleaning liquid to the cap, and a maintenance method for a liquid ejecting apparatus comprising:
A detection step of detecting the flow rate and type of the fluid sucked by the suction part;
Based on the detection result of the detection step, when it is determined that the fluid is the liquid having a flow rate equal to or lower than a threshold flow rate, the supply unit is driven to supply the cleaning liquid to the cap. And a determination step of not performing the supply step when it is determined that the fluid is air. A maintenance method for a liquid ejecting apparatus, comprising: