Inkjet printer, control method of inkjet printer, and non-transitory computer-readable medium storing computer-readable instructions

The inkjet printer includes a head, a circulation flow path, a cap, a first pump, and a control unit. The head has a nozzle surface having nozzles to eject ink. The circulation flow path circulates ink. The cap can contact the nozzle surface. The first pump is connected to an exhaust hole formed in the cap. In a soaking processing, the processor drives the first pump and causes the nozzle surface to be soaked in liquid, in a capping state in which the cap is in contact with the nozzle surface. In a circulation processing, the processor causes the ink to circulate in the circulation flow path in a state in which the nozzle surface is soaked in the liquid, after the soaking processing.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No. 2017-252031 filed Dec. 27, 2017. The contents of the foregoing application are hereby incorporated herein by reference.

BACKGROUND

The present disclosure relates to an inkjet printer, a control method of an inkjet printer, and a non-transitory computer-readable medium storing computer-readable instructions.

An inkjet printer is known that circulates ink in order to remove air bubbles and eliminate sedimentation of ink components in a head or in a flow path from an ink storage portion to the head. For example, Japanese Laid-Open Patent Publication No. 2017-87708 discloses an inkjet printer including a plurality of pressure generation chambers, a supply liquid chamber, a plurality of supply paths, a circulation liquid chamber, a plurality of circulation paths, and a circulation tank. The pressure generation chambers respectively lead to a plurality of nozzles and apply pressure to the ink. The supply liquid chamber stores the ink to be supplied to the pressure generation chambers. The supply paths supply the ink from the supply liquid chamber to the presser generation chambers. The circulation paths cause the pressure generation chambers and the circulation liquid chamber to be communicated with each other, and cause the ink in the pressure generation chambers to be stored in the circulation liquid chamber. The ink in the circulation liquid chamber is fed to the circulation tank. Thus, together with the air bubbles, the ink is collected from the circulation liquid chamber to the circulation tank via the circulation paths. Further, the sedimentation of the ink components is eliminated by the circulation of the ink.

SUMMARY

In the inkjet printer described in the above-described publication, when a circulation speed of the ink is increased in order to further remove the air bubbles and eliminate the sedimentation of the ink components, there is a possibility that the nozzle meniscus may be damaged. In this case, there is a possibility that the air bubbles may be introduced from the nozzles to the head or the ink may flow out from the nozzles.

Embodiments of the broad principles derived herein provide an inkjet printer, a control method of an inkjet printer, and a non-transitory computer-readable medium storing computer-readable instructions which reduce a possibility of air bubbles being introduced from nozzles into a head when an ink is circulated, or a possibility of flow-out of the ink from the nozzles.

The embodiments herein provide an inkjet printer including: a head provided with a nozzle surface having nozzles configured to eject an ink; a circulation flow path configured to circulate the ink; a cap capable of coming into contact with the nozzle surface; a first pump connected to an exhaust hole formed in the cap; a processor; and a memory storing computer-readable instructions which, when executed by the processor, perform processes including: a soaking processing that drives the first pump and causes the nozzle surface to be soaked in liquid, in a capping state in which the cap is in contact with the nozzle surface; and a circulation processing that causes the ink to circulate in the circulation flow path in a state in which the nozzle surface is soaked in the liquid, after the soaking processing.

The embodiments herein also provide a control method of an inkjet printer that includes a head provided with a nozzle surface having inkjet nozzles configured to eject an ink, a circulation flow path configured to circulate the ink, a cap capable of coming into contact with the nozzle surface, and a first pump connected to an exhaust hole formed in the cap. The control method includes: a soaking step of driving the first pump and causing the nozzle surface to be soaked in liquid, in a capping state in which the cap is in contact with the nozzle surface; and a circulation step of causing the ink to circulate in the circulation flow path in a state in which the nozzle surface is soaked in the liquid, after the soaking step.

The embodiments herein also provide a non-transitory computer-readable medium storing computer-readable instructions causes a processor of an inkjet printer comprising a head provided with a nozzle surface having inkjet nozzles configured to eject an ink, a circulation flow path configured to circulate the ink, a cap capable of coming into contact with the nozzle surface, a first pump connected to an exhaust hole formed in the cap, and the processor, to perform: a soaking processing that drives the first pump and causes the nozzle surface to be soaked in liquid, in a capping state in which the cap is in contact with the nozzle surface, and a circulation processing that causes the ink to circulate in the circulation flow path in a state in which the nozzle surface is soaked in the liquid, after the soaking processing.

DETAILED DESCRIPTION

Hereinafter, a print device1of a first embodiment of the present invention will be explained with reference to the drawings. An overview of the print device1will be explained with reference toFIG. 1. The upward direction, the downward direction, the left downward direction, the right upward direction, the right downward direction and the left upward direction inFIG. 1respectively correspond to an upward direction, a downward direction, a front direction, a rear direction, a right direction and a left direction of the print device1.

The print device1is an inkjet printer that performs printing on a fabric such as a T-shirt, or a recording medium such as paper, by ejecting an ink68(refer toFIG. 3) from nozzles of a head portion67(refer toFIG. 3). The print device1prints a color image on the recording medium by downwardly ejecting, for example, five different types (white (W), black (K), yellow (Y), cyan (C) and magenta (M)) of the ink68. In the following explanation, of the five types of the ink68, the white ink68is referred to as white ink. When the four colors of the ink68, i.e., the black, cyan, yellow and magenta inks, are collectively referred to, they are referred to as color inks. The white ink is an ink having higher settleability than the color inks.

As shown inFIG. 1, the print device1is provided with a housing2, a platen drive mechanism6, a pair of guide rails (not shown in the drawings), a platen5, a tray4, a frame body10, a guide shaft9, a rail7, a carriage20, head units100and200, a drive belt101and a drive motor19. An operation portion (not shown in the drawings) that is used to perform operations of the print device1is provided at a front position on the right side of the housing2. The operation portion is operated when an operator inputs commands relating to various operations of the print device1.

The frame body10has a substantially rectangular frame shape in a plan view, and is installed on an upper portion of the housing2. The front side of the frame body10supports the guide shaft9, and the rear side of the frame body10supports the rail7. The guide shaft9extends in the left-right direction on the inside of the frame body10. The rail7is disposed facing the guide shaft9and extends in the left-right direction.

The carriage20is supported such that it can be conveyed in the left-right direction along the guide shaft9. The head units100and200are mounted on the carriage20such that they are aligned in the front-rear direction. The head unit100is positioned further to the rear than the head unit200. The head portion67(refer toFIG. 2) is provided on a lower portion of each of the head units100and200. The head portion67of the head unit100ejects the white ink. The head portion67of the head unit200ejects the color inks. The head portion67is provided with a surface having a plurality of fine nozzles (not shown in the drawings) that can eject the ink68downward.

As shown inFIG. 1, the drive belt101is stretched along the left-right direction on the inside of the frame body10. The drive motor19is coupled to the carriage20via the drive belt101. When the drive motor19drives the drive belt101, the carriage20is caused to reciprocate in the left-right direction along the guide shaft9.

The platen drive mechanism6is provided with the pair of guide rails (not shown in the drawings) and a platen support base (not shown in the drawings). The pair of guide rails extend in the front-rear direction on the inside of the platen drive mechanism6, and support the platen support base such that the platen support base can move in the front-rear direction. An upper portion of the platen support base supports the platen5. The platen5supports the recording medium. The tray4is provided below the platen5. When the operator places a T-shirt or the like on the platen5, the tray4receives a sleeve or the like of the T-shirt, and thus protects the sleeve or the like such that the sleeve or the like does not come into contact with other components inside the housing2. The platen drive mechanism6is driven by a sub-scanning drive portion (not shown in the drawings), and moves the platen support base and the platen5along the pair of guide rails in the front-rear direction. Printing by the print device1on the recording medium is performed by the platen5conveying the recording medium in the front-rear direction (a sub-scanning direction) and the ink68being ejected from the head portion67that is reciprocating in the left-right direction (a main scanning direction).

As shown inFIG. 2, a maintenance portion141of the print device1is provided with a wiper36, a flushing receiving portion145, a cap66and a cap support portion69. The flushing receiving portion145is provided on a right portion of the maintenance portion141. The flushing receiving portion145is provided with a container portion146and an absorption body147. The flushing receiving portion145receives the ink that is ejected from the head portion67of the head unit100by a flushing operation. The ink is absorbed by the absorption body147.

As shown inFIG. 3, the wiper36is provided to the left of the flushing receiving portion145and below a nozzle surface112of the head unit100. The wiper36can move up and down. The wiper36extends in the front-rear direction.

As shown inFIG. 3, the print device1is provided with an ink supply portion700, a liquid storage device3and a deaeration module60. The ink supply portion700supplies the white ink68to the head portion67. The head portion67is provided with an inkjet head. Ink supply portions (not shown in the drawings) that supply the other four colors of the ink68to the head portion67of the head unit200have the same configuration as that shown inFIG. 3. The liquid storage device3supplies the white ink68to the ink supply portion700and stores the ink68that returns from the ink supply portion700. The deaeration module60removes air bubbles from the ink68that flows through a first supply flow path711to be described later. A shaft40, a first tube53, a second tube54and a remaining amount sensor42are inserted into the inside of a main tank30.

Ink Supply Portion700

The ink supply portion700supplies the ink68to the head portion67. The ink supply portion700is a portion through which the ink68circulates. The ink supply portion700is provided with the first supply flow path711, a second supply flow path712, a first circulation flow path721, a second circulation flow path722, a first connection flow path731, a second connection flow path732, a sub pouch8, the deaeration module60, a pump751, electromagnetic valves761,762,763,764,765and766, and a filter771.

The sub pouch8has a bag shape and stores the ink68supplied from the main tank30. Further, the sub pouch8supplies the ink68to the head portion67. The head portion67ejects the ink68supplied from the sub pouch8and thus performs printing on a print target. A remaining amount sensor899is mounted on the sub pouch8.

The first supply flow path711, the second supply flow path712, the first circulation flow path721, the second circulation flow path722, the first connection flow path731and the second connection flow path732are each formed by a hollow tube, for example. The first supply flow path711connects to the first tube53of the liquid storage device3and to the sub pouch8, and is a flow path that supplies the ink68from the main tank30to the sub pouch8.

The second supply flow path712connects to the sub pouch8and to the head portion67, and is a flow path that supplies the ink68from the sub pouch8to the head portion67. The first supply flow path711and the second supply flow path712converge at a first connection portion791. The first connection flow path731is a flow path between the first connection portion791and the sub pouch8. That is, the first connection flow path731is a part of the first supply flow path711and is also a part of the second supply flow path712.

The first circulation flow path721connects to the second tube54of the liquid storage device3and to the sub pouch8, and is a flow path to circulate the ink68from the sub pouch8to the main tank30. The second circulation flow path722connects to the head portion67and to the sub pouch8, and is a flow path to circulate the ink68from the head portion67to the sub pouch8. The first circulation flow path721and the second circulation flow path722converge at a second connection portion792. The second connection flow path732is a flow path between the second connection portion792and the sub pouch8. That is, the second connection flow path732is a part of the first circulation flow path721and is also a part of the second circulation flow path722.

The electromagnetic valve761is provided in the first supply flow path711. The electromagnetic valve761is positioned closer to the sub pouch8than a deaeration portion601to be described later. The electromagnetic valve761is controlled by a CPU70(refer toFIG. 5) to be described later, and opens and closes the first supply flow path711. The electromagnetic valve762is provided in the first connection flow path731. The electromagnetic valve762is controlled by the CPU70and opens and closes the first connection flow path731. The electromagnetic valve763is provided in the second supply flow path712. The electromagnetic valve763is controlled by the CPU70and opens and closes the second supply flow path712.

The electromagnetic valve764is provided in the first circulation flow path721. The electromagnetic valve764is controlled by the CPU70and opens and closes the first circulation flow path721. The electromagnetic valve765is provided in the second connection flow path732. The electromagnetic valve765is controlled by the CPU70and opens and closes the second connection flow path732. The electromagnetic valve766is provided in the second circulation flow path722. The electromagnetic valve766is controlled by the CPU70and opens and closes the second circulation flow path722.

The filter771is provided in the first supply flow path711. The filter771removes foreign matter contained in the ink68that flows through the first supply flow path711. The pump751is provided in the first supply flow path711. The pump751is provided closer to the sub pouch8than the filter711. The pump51sucks up the ink68from the main tank30and causes the ink68to flow to the sub pouch8side, which is the downstream side.

The deaeration module60is provided in the first supply flow path711. The deaeration module60is provided with the deaeration portion601, a vacuum filter602, a pressure reducing pump603, an electromagnetic valve604, an air intake filter605, a pathway606, a pathway608and a pathway609. The deaeration portion601is provided in the first supply flow path711. The deaeration portion601is positioned between the pump751and the electromagnetic valve761. The vacuum filter602is connected to the deaeration portion601via the pathway606. The pathway606is connected to the pathway608at a connection portion607. The air intake filter605is connected to the pathway608. The electromagnetic valve604is provided in the pathway608. The pressure reducing pump603is connected to the vacuum filter602via the pathway609.

The pressure reducing pump603operates under the control of the CPU70, and depressurizes the pathway606via the vacuum filter602. Therefore, air bubbles contained in the ink68flowing through the deaeration portion601are reduced. When the pathway606is depressurized, the electromagnetic valve604is controlled by the CPU70and closes the pathway608. When the pathway606is not depressurized, the electromagnetic valve604is controlled by the CPU70and opens the pathway608. When the pathway608is opened, ambient air is supplied to the pathway606via the air intake filter605and the pathway606. Thus, the depressurized state of the pathway606is released. The air intake filter605removes foreign matter from the ambient air flowing to the pathway608side.

Further, in the print device1shown inFIG. 3, the second supply flow path712and the second circulation flow path722are connected by a bypass flow path801. The second supply flow path712is connected to the bypass flow path801at a third connection portion795that is provided between the electromagnetic valve763and the head portion67. Further, the second circulation flow path722is connected to the bypass flow path801at a fourth connection portion796that is provided between the electromagnetic valve766and the head portion67. The bypass flow path801is provided with an electromagnetic valve767, a filter772and a pump752, from the third connection portion795toward the fourth connection portion796. The electromagnetic valve767opens and closes the bypass flow path801. The filter772removes foreign matter contained in the ink68that flows through the bypass flow path801.

Configuration of First Nozzle Portion167and Second Nozzle Portion267

As shown inFIG. 4, the head portion67has the first nozzle portion167and the second nozzle portion267. The first nozzle portion167has a plurality of liquid flow paths171to174and a plurality of nozzle arrays L1to L6that are arrayed in a first pattern. The second nozzle portion267has a plurality of liquid flow paths175to177and a plurality of nozzle arrays L7to L12that are arrayed in a second pattern. The liquid flow path171of the first nozzle portion167is communicated with nozzles111included in the nozzle array L1. The liquid flow path172is communicated with the nozzles111included in the nozzle arrays L2and L3. The liquid flow path173is communicated with the nozzles111included in the nozzle arrays L4and L5. The liquid flow path174is communicated with the nozzles111included in the nozzle array L6. Front end portions of the liquid flow paths171,172,173and174are respectively provided with supply ports131,132,133and134. The supply ports131to134can supply the ink68to the liquid flow paths171to174, respectively.

Further, the liquid flow path175of the second nozzle portion267is communicated with the nozzles111included in the nozzle arrays L7and L8. The liquid flow path176is communicated with the nozzles111included in the nozzle arrays L9and L10. The liquid flow path177is communicated with the nozzles111included in the nozzle arrays L11and L12. Front end portions of the liquid flow paths175,176and177are respectively provided with supply ports135,136and137. The supply ports135to137can supply the ink68to the liquid flow paths175to177, respectively.

Rear end portions of the liquid flow paths171to174are provided with a communication path151, and the communication path151connects the rear end portions of the liquid flow paths171to174. Further, rear end portions of the liquid flow paths175to177are provided with a communication path152, and the communication path152connects the rear end portions of the liquid flow paths175to177. The communication path151and the communication path152are connected by a communication path153.

When printing is performed on the recording medium, as described above, the ink68is supplied from the supply ports131to137to the liquid flow paths171to177, respectively, and is ejected from the nozzle arrays L11to L12. Further, when ink circulation (refer to step S14inFIG. 6and step S34inFIG. 10) to be described later is performed, the ink68flows from one side of the first nozzle portion167and the second nozzle portion267to the other side. For example, the ink68flows from the supply ports131to134to the liquid flow paths171to174, respectively, and further, the ink68flows from the communication path151to the communication path152via the communication path153. Then, the ink68flows from the communication path152to the liquid flow paths175to177and returns to the supply ports135to137. Thus, when the ink circulation processing is performed, the liquid flow paths171to174, the communication path151, the communication path153, the communication path152, and the liquid flow paths175to177form a circulation flow path of the ink68inside the head portion67. A flow path resistance outside the head portion67is smaller than a flow path resistance inside the head portion67. For example, a cross-sectional area of each of the liquid flow paths171to174, the communication path151, the communication path153, the communication path152, and the liquid flow paths175to177is smaller than a cross-sectional area of each of the first supply flow path711, the second supply flow path712, the first circulation flow path721, the second circulation flow path722and the bypass flow path801.

From the Hagen-Poiseuille law, the flow path resistance is represented by the following Equation 1.
Flow path resistance=(8×ρ×L)/(π×r4)  Equation 1

r: radius of flow path, ρ: viscosity coefficient of ink68, L: length of flow path

Therefore, as the cross-sectional area (π×r2) becomes smaller, the flow path resistance becomes larger. The cross-sectional area of each of the first supply flow path711, the second supply flow path712, the first circulation flow path721, the second circulation flow path722and the bypass flow path801is larger than the cross-sectional area of each of the liquid flow paths171to174, the communication path151, the communication path153, the communication path152, and the liquid flow paths175to177. Therefore, the flow path resistance of each of the first supply flow path711, the second supply flow path712, the first circulation flow path721, the second circulation flow path722and the bypass flow path801is smaller than the flow path resistance of each of the liquid flow paths171to174, the communication path151, the communication path153, the communication path152and the liquid flow paths175to177. Note that each cross-sectional area is defined by a direction that is perpendicular to the direction in which the ink68flows in each of the flow paths.

Further, the pressure of the ink68that flows in the flow path is represented by the following Equation 2.
PressureP=flow path resistance×flow rate of the ink 68  Equation 2

Further, when the pressure at the entrance of the flow path is denoted by Pin and the pressure at the exit of the flow path is denoted by Pout, a pressure difference ΔP is represented by the following Equation 3.
ΔP=Pin−Pout  Equation 3

When ΔP is a positive value, the meniscus is pushed out from the nozzles111. Further, when ΔP is a negative value, air bubbles are introduced into the nozzles111.

Cleaning Liquid Supply Path90

As shown inFIG. 7, the cleaning liquid supply path90is provided with a cleaning liquid tank32, a supply flow path110, a drainage flow path120, a pump199and a drainage tank33. The cleaning liquid tank32stores a cleaning liquid92. The supply flow path110connects the cleaning liquid tank32and a supply hole661of the cap66, and supplies the cleaning liquid92to the inside of the cap66. Further, the supply flow path110is provided with an atmospheric air opening113, an electromagnetic valve114and an electromagnetic valve115. The electromagnetic valve114opens and closes the atmospheric air opening113. The electromagnetic valve115opens and closes the supply flow path110. The drainage flow path120connects an exhaust hole662of the cap66and the drainage tank33, and discharges the ink68and the cleaning liquid92in an inner portion663of the cap66to the drainage tank33. The drainage flow path120is provided with an electromagnetic valve121and the pump199. The electromagnetic valve121opens and closes the drainage flow path120. The pump199sucks in air and the cleaning liquid92in the supply flow path110. Further, the pump199sucks in air, the ink68and the cleaning liquid92in the inner portion663of the cap66, and air, the ink68and the cleaning liquid92in the drainage flow path120, and discharges them to the drainage tank33.

Electrical Configuration of Print Device1

The electrical configuration of the print device1will be explained with reference toFIG. 5. The print device1is provided with the CPU70that controls the print device1. A ROM56, a RAM57, an EEPROM58, a head drive portion61, a main scanning drive portion62, a sub-scanning drive portion63, a wiper drive portion64, a cap drive portion65, the remaining amount sensor42, the remaining amount sensor899, a pump drive portion21, a pump drive portion22, a pump drive portion26, a pump drive portion27, a pump drive portion28, a display control portion51, an operation processing portion50, a first drive portion23, a second drive portion24and a third drive portion25are electrically connected to the CPU70via a bus55.

The ROM56stores a control program, initial values and the like that are used by the CPU70to control operations of the print device1. The RAM57temporarily stores various data that are used in the control program. The EEPROM58stores a date and time at which the ink circulation processing (step S14, step S34) to be described later is performed. The head drive portion61is electrically connected to the head portion67that ejects the ink68. The head drive portion61drives a piezoelectric element that is provided in each of ejection channels of the head portion67, and causes the ink68to be ejected from the nozzles111.

The main scanning drive portion62includes the drive motor19(refer toFIG. 1) and causes the carriage20to move in the main scanning direction. The sub-scanning drive portion63uses a drive motor (not shown in the drawings) to drive the platen drive mechanism6(refer toFIG. 1), and causes the platen5(refer toFIG. 1) to move in the sub-scanning direction.

The CPU70controls the display control portion51and displays an image on a display511. The operation processing portion50outputs, to the CPU70, a signal that is based on an operation of an operation button501by a user. The remaining amount sensor42outputs, to the CPU70, a signal indicating a remaining amount of the ink68in the main tank30. The remaining amount sensor899outputs, to the CPU70, a signal indicating a remaining amount of the ink68in the sub pouch8.

The CPU70controls the opening and closing of the electromagnetic valves761to767via the first drive portion23, and opens and closes the first supply flow path711, the second supply flow path712, the first circulation flow path721, the second circulation flow path722, the first connection flow path731and the second connection flow path732. The CPU70controls the opening and closing of the electromagnetic valves114,115and121via the second drive portion24, and opens and closes the supply flow path110(refer toFIG. 7). The CPU70controls the pump drive portions21,22,26,27and28and drives the pump199, a pump780, the pressure reducing pump603, the pump751and the pump752, respectively.

Ink Soaking and Ink Circulation Processing

Ink soaking and ink circulation processing will be explained with reference toFIG. 6toFIG. 9. In the print device1, the ink circulation (step S14) is performed at a certain time interval in order to remove air bubbles contained in the ink68in the ink flow paths and to eliminate sedimentation of ink components, such as pigments. In this case, if the ink circulation processing (step S14) is performed by increasing a circulation speed of the ink68in order to further remove the air bubbles and eliminate the sedimentation of the ink components, there is a possibility that the nozzle meniscus may be damaged. If the meniscus is damaged, in some cases, a failure occurs such that the air bubbles infiltrate from the nozzles into the head or the ink flows out from the nozzles. In the present embodiment, the following ink soaking and ink circulation processing is performed in order to perform the ink circulation processing (step S14) by increasing the circulation speed of the ink68while reducing the possibility of the occurrence of the failure. The explanation will be given below.

For example, when a power source of the print device1is turned on, the CPU70reads out, from the ROM56, a program for main processing (not shown in the drawings) that performs main control of a printing operation etc. of the print device1, a program for the ink soaking and ink circulation processing, and the like, and loads the programs to the RAM57. In accordance with the programs, the CPU70performs the main processing and the ink soaking and ink circulation processing. Note that, as shown inFIG. 7A, when the printing operation is not performed by the head portion67ejecting the ink68, processing is performed in which the cap66comes into contact with the nozzle surface112of the head portion67and inhibits the nozzles111from drying up.

As shown inFIG. 6, in the ink soaking and ink circulation processing, first, the CPU70determines whether to perform the ink circulation (step S11). For example, when a certain period of time has elapsed from the date and time of the previous ink circulation processing (step S14) stored in the EEPROM58, the CPU70determines that the ink circulation processing is to be performed (yes at step S11). The certain period of time is seven hours, for example. When the CPU70determines that the ink circulation processing is not to be performed (no at step S11), the CPU70repeats the processing at step S11.

When the CPU70determines that the ink circulation is to be performed (yes at step S11), the CPU70performs nozzle suction (step S12). For example, as shown inFIG. 7B, the CPU70closes the electromagnetic valve115, opens the electromagnetic valve121, and drives the pump199. Note that the electromagnetic valve114may be closed or remain open. Thus, the ink68is sucked in from the nozzles111of the head portion67. Then, the CPU70performs ink soaking (step S13). For example, as shown inFIG. 7C, the CPU70drives the pump199for a certain period of time and fills the inner portion663of the cap66with the ink68. In a state in which the nozzle surface112is soaked in the ink68, the CPU70stops the pump199and closes the electromagnetic valve121.

Next, the CPU70performs the ink circulation (step S14). For example, as shown inFIG. 3, when the circulation is performed between the head portion67and the bypass flow path801, the CPU70opens the electromagnetic valve767and closes the electromagnetic valves763and766. Next, the CPU70drives the pump752. Thus, as shown inFIG. 3, the circulation of the ink68is performed in the second supply flow path712, the head portion67, the second circulation flow path722and the bypass flow path801(refer to arrows491). As shown inFIG. 4, inside the head portion67, the ink68circulates in an order of the liquid flow paths171to174, the communication path151, the communication path153, the communication path152and the liquid flow paths175to177. Thus, in the state in which the nozzle surface112is soaked in the ink68, the circulation of the ink68is performed in the second supply flow path712, the head portion67, the second circulation flow path722and the bypass flow path801(refer to the arrows491). Further, the CPU70stores, in the EEPROM58, the date and time at which the ink circulation is performed.

Next, the CPU70performs ink discharge (step S15). For example, as shown inFIG. 8A, the CPU70opens the electromagnetic valves114and115and opens the atmospheric air opening113, thus causing the inner portion663of the cap66to be in an atmospheric air communication state. Further, the CPU70opens the electromagnetic valve121and drives the pump199. Therefore, the ink68which has been discharged from the nozzles111to the inner portion663of the cap66and which contains dirt from the inner portion663of the cap66is discharged from the exhaust hole662to the drainage tank33via the drainage flow path120.

Next, the CPU70performs nozzle suction (step S16). For example, as shown inFIG. 8B, in a capping state in which the cap66is in contact with the nozzle surface112, the CPU70closes the electromagnetic valve115and causes the inner portion663of the cap66to be in an atmospheric air non-communication state. Then, the CPU70opens the electromagnetic valve121, drives the pump199, and sucks in the ink68from the nozzles111. Note that the electromagnetic valve114may be closed or remain open. Thus, the ink68containing the dirt that has entered into the nozzles111at the time of the ink soaking, is discharged. Next, as shown inFIG. 8C, the CPU70performs ink discharge (step S17). The ink discharge (step S17) is the same processing as the above-described ink discharge (step S15), and an explanation thereof is thus omitted here.

Next, as shown inFIG. 9A, the CPU70performs nozzle cleaning (step S18). For example, the CPU70closes the electromagnetic valve114, opens the electromagnetic valves115and121, and drives the pump199, thus filling the inner portion663of the cap66with the cleaning liquid92in the cleaning liquid tank32via the supply flow path110. At this time, the nozzle surface112is soaked in the cleaning liquid92to clean the nozzle surface112.

Next, the CPU70performs discharge of the cleaning liquid92(step S19). For example, as shown inFIG. 9B, the CPU70opens the electromagnetic valves114and115, opens the atmospheric air opening113, and causes the inner portion663of the cap66to be in the atmospheric air communication state. Further, the CPU70opens the electromagnetic valve121and drives the pump199. Thus, the cleaning liquid92, which is filled in the inner portion663of the cap66and which contains dirt, is discharged from the exhaust hole662to the drainage tank33via the drainage flow path120.

Next, the CPU70performs separation and suction of the cap66(step S20). For example, as shown inFIG. 9C, the CPU70controls the cap drive portion65(refer toFIG. 5) and causes the cap66to separate from the nozzle surface112. At the same time, the CPU70opens the electromagnetic valves114,115and121and drives the pump199. As a result, the cleaning liquid92containing the dirt and remaining in the inner portion663of the cap66and the drainage flow path120is discharged to the drainage tank33.

Next, the CPU70performs wiping and flushing (step S21). First, the CPU70causes the wiper36to come into contact with the nozzle surface112by controlling the wiper drive portion64, and causes the wiper36to wipe off the cleaning liquid92and the ink68remaining on the nozzle surface112. Then, the CPU70performs flushing. For example, the CPU70causes the main scanning drive portion62to move the head portion67onto the flushing receiving portion145(refer toFIG. 2), and causes the flushing receiving portion145(refer toFIG. 2) to eject the ink68from the nozzles111. As a result of performing the flushing, the nozzle meniscus is adjusted and the ink68is appropriately ejected from the nozzles111.

Next, as shown inFIG. 7A, the CPU70performs capping (step S22). For example, the CPU70controls the cap drive portion65(refer toFIG. 5) and causes the cap66to come into contact with the nozzle surface112, thus covering the nozzles111. Then, the CPU70returns the processing to step S11.

Operations and Effects of First Embodiment

As explained above, in the print device1of the first embodiment, in the state in which the nozzle surface112is soaked in the ink68, the circulation of the ink68is performed in the second supply flow path712, the head portion67, the second circulation flow path722and the bypass flow path801(refer to the arrows491). It is therefore possible to reduce the possibility of introducing air bubbles from the nozzles111into the head portion67. Further, it is possible to reduce the possibility of flow out of the ink68from the nozzles111. Therefore, the ink68can be circulated by increasing the circulation speed of the ink68in the circulation flow path of the ink68.

Further, when the ink circulation (step S14) is performed, as shown inFIG. 7C, the nozzle surface112is soaked in the ink68. In this state, inside the head portion67, the ink68circulates in the order of the liquid flow paths171to174, the communication path151, the communication path153, the communication path152and the liquid flow paths175to177. Thus, when the ink68circulates in the circulation flow path inside the head portion67, it is possible to reduce the possibility of introducing air bubbles from the nozzles111into the head portion67. Further, it is possible to reduce the possibility of flow out of the ink68from the nozzles111.

After the ink circulation (step S14), the ink68which has been discharged from the nozzles111to the inner portion663of the cap66and which contains the dirt of the inner portion663of the cap66is discharged from the exhaust hole662by the ink discharge (step S15). It is therefore possible to reduce a possibility that the ink68containing the dirt may infiltrate into the nozzles111.

After the ink discharge (step S15), in the capping state in which the cap66is in contact with the nozzle surface112, the CPU70causes the inner portion663of the cap66to be in the atmospheric air non-communication state. Then, the CPU70opens the electromagnetic valve121, drives the pump199, and performs the nozzle suction (step S16) that sucks in the ink68from the nozzles111. It is therefore possible to discharge the ink68containing the dirt, which has entered into the nozzles111at the time of the ink soaking (step S13). Thus, it is possible to inhibit a deterioration in quality of the ink68in the nozzles111.

After the ink discharge (step S15), the CPU70causes the wiper36to come into contact with the nozzle surface112and causes the wiper36to wipe off the cleaning liquid92and the ink68remaining on the nozzle surface112(step S21). It is thus possible to adjust the meniscus of the nozzles111.

Before the ink soaking (step S13), the CPU70causes the inner portion663of the cap66to be in the atmospheric air non-communication state. Then, the CPU70drives the pump199, and performs the nozzle suction (step S12) in order to discharge the ink68from the nozzles111. Therefore, the ink68precipitated in the head portion67can be discharged from the nozzles111in advance, and the effect of the circulation of the ink68can be enhanced.

In the print device1of the first embodiment, the soaking (step S13) is performed using the ink68. Therefore, even when the ink68infiltrates into the nozzles111, adverse effects are unlikely to occur.

Second Embodiment

Next, a second embodiment will be explained. The second embodiment is the same as the first embodiment in the mechanical configuration and the electrical configuration of the print device1. The second embodiment differs in that cleaning liquid soaking and ink circulation processing is performed instead of the ink soaking and ink circulation processing. The cleaning liquid soaking and ink circulation processing will be explained with reference toFIG. 10andFIG. 11.

For example, when the power source of the print device1is turned on, the CPU70reads out, from the ROM56, the program for the main processing (not shown in the drawings) that performs main control of the printing operation and the like of the print device1, a program for the cleaning liquid soaking and ink circulation processing, and the like, and loads the programs to the RAM57. In accordance with the programs, the CPU70performs the main processing and the cleaning liquid soaking and ink circulation processing. Note that, as shown inFIG. 7A, when the printing operation is not performed by the head portion67ejecting the ink68, the cap66comes into contact with the nozzle surface112of the head portion67and inhibits the nozzles111from drying up.

As shown inFIG. 10, in the cleaning liquid soaking and ink circulation processing, first, the CPU70determines whether to perform ink circulation (step S31). The determination processing at step S31is the same as the determination processing at step S11of the ink soaking and ink circulation processing, and an explanation thereof is thus omitted here.

When the CPU70determines that the ink circulation is to be performed (yes at step S31), the CPU70performs nozzle suction (step S32). The nozzle suction (step S32) is the same processing as the nozzle suction (step S12) of the ink soaking and ink circulation processing shown inFIG. 7B, and an explanation thereof is thus omitted here. Next, the CPU70performs nozzle cleaning and cleaning liquid soaking (step S33). For example, as shown inFIG. 11A, the CPU70closes the electromagnetic valve114, opens the electromagnetic valves115and121, and drives the pump199, thus filling the inner portion663of the cap663with the cleaning liquid92in the cleaning liquid tank32via the supply flow path110. At this time, the nozzle surface112is soaked in the cleaning liquid92to clean the nozzle surface112. Next, as shown inFIG. 11B, the CPU70stops the pump199, closes the electromagnetic valves115and121, and maintains the state in which the nozzle surface112is soaked in the cleaning liquid92.

Next, the CPU70performs ink circulation (step S34). The ink circulation (step S34) is the same processing as the ink circulation (step S14) of the ink soaking and ink circulation processing, and an explanation thereof is thus omitted here. Next, the CPU70performs cleaning liquid discharge (step S35). The cleaning liquid discharge (step S35) is the same processing as the cleaning liquid discharge (step S19) shown inFIG. 9B, and an explanation thereof is thus omitted here. Next, the CPU70performs nozzle suction (step S36), ink discharge (step S37), nozzle cleaning (step S38), cleaning liquid discharge (step S39), cap separation and suction (step S40), wiping and flushing (step S41), and capping (step S42). The processing of the nozzle suction (step S36) to the capping (step S42) is the same as the processing of each of the nozzle suction (step S16), the ink discharge (step S17), the nozzle cleaning (step S18), the cleaning liquid discharge (step S19), the cap separation and suction (step S20), the wiping and flushing (step S21), and the capping (step S22) of the ink soaking and ink circulation processing, and an explanation thereof is thus omitted here.

Operations and Effects of Second Embodiment

As explained above, in the print device1of the second embodiment, in the state in which the nozzle surface112is soaked in the cleaning liquid92, the circulation of the ink68is performed in the second supply flow path712, the head portion67, the second circulation flow path722and the bypass flow path801(refer to the arrows491). It is therefore possible to reduce the possibility of introducing air bubbles from the nozzles111into the head portion67. Further, it is possible to reduce the possibility of flow out of the ink68from the nozzles111. Thus, the ink68can be circulated by increasing the circulation speed of the ink68in the circulation flow path of the ink68.

Further, when the ink circulation (step S34) is performed, as shown inFIG. 11B, the nozzle surface112is soaked in the cleaning liquid92. In this state, inside the head portion67, the ink68circulates in the order of the liquid flow paths171to174, the communication path151, the communication path153, the communication path152and the liquid flow paths175to177. Thus, when the ink68circulates in the circulation flow path inside the head portion67, it is possible to reduce the possibility of introducing air bubbles from the nozzles111into the head portion67. Further, it is possible to reduce the possibility of flow out of the ink68from the nozzles111.

After the ink circulation (step S34), the cleaning liquid92containing the dirt of the inner portion663of the cap66is discharged from the exhaust hole662by the cleaning liquid discharge (step S35). It is therefore possible to reduce the possibility that the cleaning liquid92containing the dirt may infiltrate into the nozzles111.

After the cleaning liquid discharge (step S35), in the capping state in which the cap66is in contact with the nozzle surface112, the CPU70causes the inner portion663of the cap66to be in the atmospheric air non-communication state. Then, the CPU70opens the electromagnetic valve121, drives the pump199, and performs the nozzle suction (step S36) that sucks in the ink68from the nozzles111. It is therefore possible to discharge the cleaning liquid92containing the dirt, which has entered into the nozzles111at the time of the cleaning liquid soaking (step S33). Thus, it is possible to inhibit the deterioration in the quality of the ink68in the nozzles111.

After the cleaning liquid discharge (step S35), the CPU70causes the wiper36to come into contact with the nozzle surface112and causes the wiper36to wipe off the cleaning liquid92and the ink68remaining on the nozzle surface112(step S41). It is therefore possible to adjust the meniscus of the nozzles111.

Before the nozzle cleaning and cleaning liquid soaking (step S33), the CPU70causes the inner portion663of the cap66to be in the atmospheric air non-communication state. Then, the CPU70drives the pump199, and performs the nozzle suction (step S32) that sucks in the ink68from the nozzles111. Therefore, the ink68precipitated in the head portion67can be discharged from the nozzles111in advance, and the effect of the circulation of the ink68can be enhanced.

Further, as described above, the cross-sectional area of each of the liquid flow paths171to174, the communication path151, the communication path153, the communication path152, and the liquid flow paths175to177is smaller than the cross-sectional area of each of the first supply flow path711, the second supply flow path712, the first circulation flow path721and the second circulation flow path722. Therefore, the flow path resistance of each of the first supply flow path711, the second supply flow path712, the first circulation flow path721and the second circulation flow path722is smaller than the flow path resistance of each of the liquid flow paths171to174, the communication path151, the communication path153, the communication path152and the liquid flow paths175to177. It is therefore possible to reduce the possibility that the ink68and the cleaning liquid92containing dirt may infiltrate from the nozzles111.

Next, the flow path resistance of the circulation flow path will be explained with reference toFIG. 12.FIG. 12is a diagram schematically showing the configuration of the circulation flow path of the ink68between the head portion67and the bypass flow path801shown inFIG. 3. In the circulation flow path shown inFIG. 12, the second supply flow path712is referred to as an outward path71. Further, the second circulation flow path722and the bypass flow path801are referred to as a return path72. The outward path71is a flow path extending from the pump752toward the first nozzle portion167of the head portion67. The return path72is a flow path extending from the second nozzle portion267toward the pump752via the second circulation flow path722and the bypass flow path801. The outward path71is provided with the filter772that increases the flow path resistance of the outward path71to be larger than the flow path resistance of the return path72. As a result, the pressure of the ink68flowing through the outward path71becomes smaller than the pressure of the ink68flowing through the return path72. Thus, the pressure of the ink68in the first nozzle portion167and the second nozzle portion267becomes negative. It is thus possible to increase adhesion of the cap66to the nozzle surface112.

Note that the present invention is not limited to the above-described embodiments and various modifications are possible. For example, in the first embodiment and the second embodiment described above, the ink circulation in the processing at step S14and step S34is the circulation between the head portion67and the bypass flow path801. However, the ink circulation is not limited to this example. For example, the ink circulation may be circulation between the head portion67and the main tank30. When the circulation between the head portion67and the main tank30is performed, the CPU70opens the electromagnetic valves761,763,764and766, and closes the electromagnetic valves762and765. Then, the CPU70drives the pump751. Thus, the ink68is sucked up from the main tank30, and flows to the main tank30via the first supply flow path711, the second supply flow path712, the head portion67, the second circulation flow path722and the first circulation flow path721. In this case also, the circulation of the ink68(step S14, step S34) is performed in the state in which the nozzle surface112is soaked in the ink68or the nozzle surface112is soaked in the cleaning liquid92. It is therefore possible to reduce the possibility of introducing air bubbles from the nozzles111into the head portion67. Further, it is possible to reduce the possibility of flow out of the ink68from the nozzles111. Thus, the ink68can be circulated by increasing the circulation speed of the ink68in the circulation between the head portion67and the main tank30.

Further, the ink circulation may be circulation of the ink68between the sub pouch8and the main tank30. For example, the CPU70opens the electromagnetic valves761,762,765and764. Then, the CPU70drives the pump751. Therefore, the ink68is sucked up from the main tank30, and flows to the main tank30via the first supply flow path711, the sub pouch8and the first circulation flow path721. In this case also, the circulation of the ink68(step S14, step S34) is performed in the state in which the nozzle surface112is soaked in the ink68or the nozzle surface112is soaked in the cleaning liquid92. Therefore, even when pressure fluctuations of the ink68that circulates between the sub pouch8and the main tank30are transmitted to the head portion67side via the second supply flow path712and the second circulation flow path722, it is possible to reduce the possibility of introducing air bubbles from the nozzles111into the head portion67. Further, it is possible to reduce the possibility of flow out of the ink68from the nozzles111. Thus, the ink68can be circulated by increasing the circulation speed of the ink68in the circulation between the sub pouch8and the main tank30.

Further, the ink circulation at step S14and step S34may be circulation between the sub pouch8and the bypass flow path801. For example, the CPU70opens the electromagnetic valves762,763,767,766and765, and closes the electromagnetic valves761and764. Then, the CPU70drives the pump752. As a result, the ink68circulates in an order of the sub pouch8, the second supply flow path712, the bypass flow path801, the second circulation flow path722and the sub pouch8. In this case also, the circulation of the ink68(step S14, step S34) is performed in the state in which the nozzle surface112is soaked in the ink68or the nozzle surface112is soaked in the cleaning liquid92. Therefore, even when pressure fluctuations of the ink68that circulates between the sub pouch8and the bypass flow path801are transmitted to the head portion67side via the second supply flow path712and the second circulation flow path722, it is possible to reduce the possibility of introducing air bubbles from the nozzles111into the head portion67. Further, it is possible to reduce the possibility of flow out of the ink68from the nozzles111. Thus, the ink68can be circulated by increasing the circulation speed of the ink68in the circulation between the sub pouch8and the bypass flow path801.

Further, the ink circulation in the processing at step S14and step S34may be circulation of the ink68between the bypass flow path801and the main tank30. For example, the CPU70opens the electromagnetic valves761,763,767,766and764, and closes the electromagnetic valves762and765. Then, the CPU70drives the pumps751and752. As a result, the ink68is sucked up from the main tank30, and flows to the main tank30via the first supply flow path711, the second supply flow path712, the bypass flow path801, the second circulation flow path722and the first circulation flow path721. In this case also, the circulation of the ink68(step S14, step S34) is performed in the state in which the nozzle surface112is soaked in the ink68or the nozzle surface112is soaked in the cleaning liquid92. Therefore, even when pressure fluctuations of the ink68that circulates between the bypass flow path801and the main tank30are transmitted to the head portion67side via the second supply flow path712and the second circulation flow path722, it is possible to reduce the possibility of introducing air bubbles from the nozzles111into the head portion67. Further, it is possible to reduce the possibility of flow out of the ink68from the nozzles111. Thus, the ink68can be circulated by increasing the circulation speed of the ink68in the circulation between the bypass flow path801and the main tank30.

Further, in the cleaning liquid soaking and ink circulation processing shown inFIG. 10, the nozzle suction (step S32) need not necessarily be performed. Further, the configuration of the supply flow path and the circulation flow path of the ink68is not limited to that of the above-described embodiments. The configuration of the supply flow path110and the drainage flow path120of the cleaning liquid92is not limited to that of the above-described embodiments. Further, a cartridge may be used as the storage portion of the ink68, in place of the main tank30. Further, the sub pouch8need not necessarily be provided. Furthermore, the configuration of the ink flow path inside the head portion67is not limited to that shown inFIG. 4. Furthermore, the resistance member is not limited to the filter772, and the flow path resistance may be increased by reducing the cross-sectional area of the flow path.