Liquid ejecting apparatus

A liquid ejecting apparatus includes a liquid ejecting head having nozzles and an opening surface through which the nozzles are opened, the liquid ejecting head being configured to eject liquid from the nozzles, a supply flow path configured to supply the liquid to the liquid ejecting head, a pressurizing mechanism that can pressurize the inside of the supply flow path, an opening/closing mechanism that can open and close the supply flow path, and a control unit that controls operations of the liquid ejecting head, the pressurizing mechanism, and the opening/closing mechanism.

BACKGROUND

1. Technical Field

The present invention relates to a liquid ejecting apparatus such as a printer.

2. Related Art

As an example of a liquid ejecting apparatus, there is an ink jet type printer configured to start supplying ink after precompressing a buffer tank in advance when supplying ink to a recording head through the buffer tank (for example, JP-A-2006-150745).

SUMMARY

When pressurizing a liquid to be supplied to a recording head, ink may flow out of nozzles and be wasted until the pressure falls. An advantage of some aspects of the invention is to provide a liquid ejecting apparatus that can prevent liquid from unnecessarily flowing out due to pressurization.

The liquid ejecting apparatus includes a liquid ejecting head configured to have nozzles and an opening surface, where the nozzles open, and eject liquid from the nozzles, a supply flow path arranged so as to supply the liquid to the liquid ejecting head, a pressurizing mechanism that can pressurize the inside of the supply flow path, an opening/closing mechanism that can open and close the supply flow path, and a control unit that controls operations of the liquid ejecting head, the pressurizing mechanism, and the opening/closing mechanism.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, embodiments of the liquid ejecting apparatus will be described with reference to the drawings. The liquid ejecting apparatus is, for example, an ink jet type printer that performs recording (printing) by ejecting ink that is an example of liquid to a medium such as a paper sheet.

First Embodiment

As shown inFIG. 1, a liquid ejecting apparatus11of the present embodiment includes a housing12, a liquid ejecting head13that ejects liquid in the housing12, and a maintenance apparatus31that performs maintenance of the liquid ejecting head13. The liquid ejecting head13is configured to have nozzles14and an opening surface13a, where the nozzles14open, and eject liquid from the nozzles14. The liquid ejecting head13is configured to be displaceable to a first posture shown by a solid line inFIG. 1and a second posture shown by a chain double-dashed line inFIG. 1. InFIG. 1, a vertically downward direction is defined as a gravity direction, and two horizontal directions opposite to each other are defined as a first direction X and a second direction Y.

The liquid ejecting head13performs printing by ejecting liquid to a medium S while in the first posture. In the present embodiment, a position where the medium S receives the liquid is referred to as a recording position. The maintenance apparatus31performs maintenance when the liquid ejecting head13is in the second posture. The first posture is, for example, a posture where the opening surface13aof the liquid ejecting head13is inclined with respect to horizontal, and the second posture is a posture where the inclination of the opening surface13awith respect to horizontal is smaller than that of the first posture.

In the present embodiment, when the liquid ejecting head13is in the second posture, the opening surface13ais close to horizontal. However, the opening surface13aneed not necessarily be close to horizontal, but may be closer to horizontal than in the first posture. In other words, “the inclination of the opening surface13awith respect to horizontal is smaller than that of the first posture” includes a case where the inclination of the opening surface13awith respect to horizontal is zero and the opening surface13ais horizontal.

In the present embodiment, a direction in which the medium S advances in the recording position is defined as a transport direction F, and a direction in which the liquid ejecting head13in the first posture ejects liquid is defined as an ejecting direction J. A direction different from both the transport direction F and the ejecting direction J is defined as a width direction W. Further, a length in the width direction W may be referred to as a “width”. The liquid ejecting head13of the present embodiment is a line head having a plurality of nozzles14arranged so that a printing range in the width direction W is greater than or equal to a width of the medium S.

The housing12is provided with a mounting portion20. The mounting portion20is mounted with one or a plurality (four in the present embodiment) of liquid containers19. The liquid container19may be an attachable and detachable cartridge or may be a tank into which liquid is injected.

The liquid ejecting apparatus11includes a supply flow path21arranged so as to supply liquid to the liquid ejecting head13, a pressurizing mechanism22that can pressurize the inside of the supply flow path21, an opening/closing mechanism24that can open and close the supply flow path21on the downstream side of the pressurizing mechanism22. When the opening/closing mechanism24is a first opening/closing mechanism24, the liquid ejecting apparatus11may include an opening/closing mechanism23as a second opening/closing mechanism23that can open and close the supply flow path21on the upstream side of the pressurizing mechanism22. The opening/closing mechanisms23and24are, for example, valves that can forcibly open and close the supply flow path21.

The pressurizing mechanism22includes a liquid chamber22aprovided in the middle of the supply flow path21and a drive mechanism25that pressurizes the liquid chamber22afrom the outside of the supply flow path21. The liquid chamber22aincludes an atmosphere opening valve22b. When the atmosphere opening valve22bis opened, the inside of the liquid chamber22ais opened to the atmosphere. The drive mechanism25is configured to send gas to the inside of the liquid chamber22a. The drive mechanism25is, for example, a pump that sends out gas through a gas sending pipe25a. When the drive mechanism25sends gas to the inside of the liquid chamber22atrough the atmosphere opening valve22b, the liquid inside the liquid chamber22ais pressurized. When the atmosphere opening valve22bis opened, pressure inside the liquid chamber22abecomes the atmospheric pressure and the pressurization of the liquid chamber22ais released.

The liquid ejecting apparatus11includes a moving mechanism34that moves the maintenance apparatus31along the second direction Y and a control unit100. The control unit100controls operations of the liquid ejecting head13, the maintenance apparatus31, and the opening/closing mechanisms23and24.

Next, a configuration of the maintenance apparatus31will be illustrated.

The maintenance apparatus31includes a wiping member32that can wipe the opening surface13aalong with movement relative to the liquid ejecting head13and a cap33that receives liquid discharged from the nozzles14, and a suction mechanism36that sucks the inside of the cap33. The suction mechanism36includes a suction flow path35that connects the cap33and a waste liquid container37. The wiping member32is preferable to be formed of an elastically deformable plate-shaped member such as, for example, a rubber member and an elastomer. However, the wiping member32may be formed of a liquid-absorbable cloth such nonwoven fabric, a porous material, or the like.

Maintenance operations performed by the maintenance apparatus31include flashing, capping, cleaning, and wiping.

The flashing is an operation where the liquid ejecting head13discharges liquid as waste liquid by ejecting liquid from the nozzles14.

The capping is performed when the cap33is located below the liquid ejecting head13as shown by a chain double-dashed line inFIG. 1. When the capping is performed, the cap33moves upward and forms a closed space between the cap33and the opening surface13a. In this way, the cap33is configured so as to form the closed space to which the nozzles14open. A position of the maintenance apparatus31when the capping is performed is referred to as a capping position. The capping is performed to prevent drying of the nozzles14when the liquid ejecting head13stops a liquid ejecting operation as well as when the power is off.

The cleaning is a maintenance operation for discharging foreign objects such as bubbles by outputting liquid from the nozzles14. Types of the cleaning include suction cleaning, choke cleaning, and pressurized cleaning.

When performing the suction cleaning, first, the cap33moves upward and performs the capping. When the suction mechanism36is driven in a state in which the cap33forms a closed space between the cap33and the opening surface13a, foreign objects such as bubbles located inside the liquid ejecting head13are discharged from the nozzles14along with liquid.

The choke cleaning is a kind of suction cleaning. The choke cleaning is an operation that closes the supply flow path21and drives the suction mechanism36as well as performs capping. For example, when the first opening/closing mechanism24is closed and the suction mechanism36is driven, the pressure of a region from the nozzles14to the first opening/closing mechanism24becomes negative pressure and the size of bubbles located in the region increase. Thereafter, when the supply flow path21is opened, the bubbles flow downstream. Therefore, the choke cleaning is suitable for discharging bubbles accumulated in the liquid ejecting head13and the like.

In the pressurized cleaning, liquid is discharged from the nozzles14by pressurizing the inside of the supply flow path21. The cleaning is performed when the cap33is located below the liquid ejecting head13. A position of the maintenance apparatus31when the cleaning is performed is referred to as a receiving position (position shown by a chain double-dashed line inFIG. 1). The cleaning is performed before starting print processing or after performing print processing.

The wiping is a maintenance operation to wipe the opening surface13awhen the wiping member32moves relative to the liquid ejecting head13. In the present embodiment, when the maintenance apparatus31including the wiping member32moves in a direction opposite to the second direction Y from the receiving position, a tip portion of the wiping member32wipes the opening surface13a.

It is preferable that the wiping is performed when liquid, dust, or the like is attached to the liquid ejecting head13. For example, after the cleaning, liquid discharged from the nozzles14is attached to the opening surface13a, so that it is preferable to perform the wiping. Further, when the liquid ejecting head13ejects liquid to the medium S, fine mist is generated following the ejection and the mist attaches to the opening surface13a. Therefore, when the print processing continues for a long time, it is preferable to perform the wiping at predetermined timings during the print processing.

Next, pressurized wiping performed under control of the control unit100will be described.

The pressurized wiping is wiping performed by wetting the opening surface13aby outputting liquid from the nozzles14by pressurization.

First, the pressurizing mechanism22pressurizes the inside of the supply flow path21in a state in which the first opening/closing mechanism24and the second opening/closing mechanism23close the supply flow path21. After the pressurization, the first opening/closing mechanism24opens the supply flow path21. Then, pressurized liquid flows out of the nozzles14.

The first opening/closing mechanism24closes the supply flow path21again after the first opening/closing mechanism24opens the supply flow path21, a predetermined period of time elapses, and the liquid has been outputted. After a predetermined period of time elapses from when the first opening/closing mechanism24opens the supply flow path21, and the liquid has been outputted, the first opening/closing mechanism24closes the supply flow path21again. After the first opening/closing mechanism24closes the supply flow path21in this way, the wiping member32wipes the opening surface13a. When the second opening/closing mechanism23is provided in the supply flow path21and the second opening/closing mechanism23is closed while the pressurizing mechanism22pressurizes the inside of the supply flow path21, the liquid does not flow upstream, so that it is possible to efficiently pressurize the inside of the nozzles14.

Besides the pressurized wiping, it is possible to perform pressurized cleaning when the first opening/closing mechanism24opens the supply flow path21and the first opening/closing mechanism24closes the supply flow path21again after a predetermined period of time elapses and the liquid has been outputted. After the pressurized cleaning, it is preferable to wipe the opening surface13ato which the liquid is attached by using the wiping member32.

It is possible to perform the pressurized cleaning and the pressurized wiping in the same manner. However, to perform in particular the pressurized cleaning, the amount of liquid to be discharged or an execution timing may be changed from those of the pressurized wiping. For example, in the pressurized cleaning, the amount of discharged liquid may be increased by increasing a pressurizing force to grater than that in the pressurized wiping. Alternatively, the execution timing may be varied in such a way that the pressurized cleaning is performed when resuming printing after a long non-operational state and the pressurized wiping is performed after executing printing.

Next, operations and effects of the liquid ejecting apparatus11of the present embodiment will be described.

When the first opening/closing mechanism24is opened after the first opening/closing mechanism24is closed and pressurization is performed, a flowing speed of liquid flowing toward the nozzles14becomes faster than that in a case where the pressurization is performed without closing the first opening/closing mechanism24.

When performing cleaning, if the flowing speed of liquid is increased or a shock is given by rapid pressure fluctuation, bubble dischargeability is improved. Therefore, according to the present embodiment, it is possible to efficiently discharge foreign objects and the like in the nozzles14. When there are a large number of nozzles14, it is possible to evenly apply a pressurizing force to each of the nozzles14by opening the supply flow path21after closing and pressurizing the supply flow path21.

When the opening/closing mechanism24closes the supply flow path21after a predetermined period of time elapses after the liquid is flown out of the nozzles14, the flowing out of the liquid stops. When the wiping is performed in this state, the liquid flown out of the nozzles14is attached to the opening surface13a, so that the opening surface13ais not easily damaged and it is possible to dissolve the solidified foreign objects it in a liquid and remove the foreign objects. Further, during the wiping, the supply flow path21is closed, so that the liquid is not easily flown out unnecessarily even when the wiping member32comes into contact with a liquid surface in the nozzles14.

Second Embodiment

Next, a second embodiment of the liquid ejecting apparatus will be described.

In the following description, components denoted by the same reference numerals have the same functions as those of the components described above, so that the description thereof will be omitted and new components will be mainly described. Portions having similar components in different embodiments can be exchanged and implemented.

As shown inFIG. 2, the pressurizing mechanism22of the present embodiment includes a liquid chamber73provided in the middle of the supply flow path21and a drive mechanism26that pressurizes the liquid chamber73from the outside of the supply flow path21. At least a part of a wall surface of the liquid chamber73includes a flexible film77that can be bent and displaced, and the drive mechanism26is configured to displace the flexible film77by pressing the flexible film77.

The supply flow path21of the present embodiment is provided with a pressure adjusting mechanism70. The pressure adjusting mechanism70is configured to adjust pressure of the liquid supplied to the liquid ejecting head13. It is preferable that the pressure adjusting mechanism70shares some components (at least the liquid chamber73and the flexible film77) with the pressurizing mechanism22. The pressure adjusting mechanism70has a valve body74that opens and closes the supply flow path21by interlocking with displacement of the flexible film77.

The pressure adjusting mechanism70includes a supply chamber71provided in the middle of the supply flow path21, a liquid chamber73that can communicate with the supply chamber71through a communication hole72, and a pressure receiving member75whose proximal end is contained in the supply chamber71and whose distal end is contained in the liquid chamber73. The valve body74is an elastic body that opens and closes the communication hole72according to displacement of the pressure receiving member75. The valve body74is attached to the proximal end portion of the pressure receiving member75which is located in the supply chamber71.

A part of the wall surface of the liquid chamber73is formed of the flexible film77. The pressure adjusting mechanism70includes a first energizing member78contained in the supply chamber71and a second energizing member79contained in the liquid chamber73. The first energizing member78energizes the valve body74in a direction to close the communication hole72through the pressure receiving member75.

The pressure receiving member75is displaced by being pressed by the flexible film77that is bent and displaced in a direction to reduce the volume of the liquid chamber73. The flexible film77is bent and displaced in the direction to reduce the volume of the liquid chamber73when the internal pressure of the liquid chamber73is lowered according to discharge of liquid from the nozzles14. Then, when a pressure (internal pressure) applied to an inner surface of the flexible film77, which is a surface facing the liquid chamber73, becomes lower than a pressure (external pressure) applied to an outer surface of the flexible film77, which is a surface opposite to the liquid chamber73, and when a difference between the pressure applied to the inner surface and the pressure applied to the outer surface becomes greater than or equal to a predetermined value Pn (for example, 1 kPa), the pressure receiving member75is displaced and the valve body74is switched from a valve closed state to a valve open state.

The predetermined value Pn mentioned here is a value determined according to the energizing forces of the first energizing member78and the second energizing member79, a force required to displace the flexible film77, a pressing force (sealing load) required to close the communication hole72by the valve body74, a pressure in the supply chamber71that is applied to the pressure receiving member75in the supply chamber71and a surface of the valve body74, and a pressure in the liquid chamber73. Here, the greater the sum of the energizing forces of the first energizing member78and the second energizing member79, the greater the predetermined value Pn. The energizing forces of the first energizing member78and the second energizing member79are set so that, for example, the pressure in the liquid chamber73becomes a negative pressure (for example, −1 kPa when the pressure applied to the outer surface of the flexible film77is the atmospheric pressure) within a range where a meniscus (a liquid surface curved in a concave shape) can be formed on a gas-liquid interface in the nozzle14.

When the communication hole72is opened and liquid flows into the liquid chamber73from the supply chamber71, the internal pressure of the liquid chamber73rises. When the internal pressure of the liquid chamber73reaches about −1 kPa corresponding to the above-mentioned predetermined value Pn, the valve body74closes the communication hole72. Therefore, the pressure in a region from the liquid chamber73to the nozzles14is maintained at about −1 kPa. In this way, the valve body74autonomously opens and closes the communication hole72according to a differential pressure between the external pressure of the liquid chamber73(the atmospheric pressure) and the internal pressure of the liquid chamber73. Therefore, the pressure adjusting mechanism70is classified into a differential pressure valve (in particular, a pressure reduction valve among differential pressure valves), and the valve body74functions as a pressure adjusting valve that can open and close so as to adjust the pressure of liquid supplied to the liquid ejecting head13.

The drive mechanism26is configured to move the valve body74and forcibly open the communication hole72by pressing the pressure receiving member75from the outside of the liquid chamber73over the flexible film77. When the drive mechanism26displaces the flexible film77to the inside of the liquid chamber73during maintenance by the operation of the drive mechanism26described above, the inside of the supply flow path21is pressurized by the liquid flown out of the liquid chamber73. Thereby, it is possible to eject liquid from the nozzles14and perform the pressurized cleaning or the pressurized wiping.

A filter28provided upstream of the pressurizing mechanism22and a filter chamber29where the filter28is arranged may be provided in the middle of the supply flow path21of the present embodiment. The filter chamber29is divided into a primary side (upstream side) and a secondary side (downstream side) by the filter28. A bubble chamber29ais provided at an upper region of the primary side of the filter chamber29. Bubbles collected by the filter28enter the bubble chamber29aby buoyancy.

A one-way valve27is provided between the pressure adjusting mechanism70and the filter28in the supply flow path21of the present embodiment. The one-way valve27allows liquid to flow downstream and controls liquid to flow upstream. When the filter28and the filter chamber29are not provided, the one-way valve27may be arranged upstream the pressurizing mechanism22in the supply flow path21.

Next, operations and effects of the liquid ejecting apparatus11of the present embodiment will be described.

When there is the pressure adjusting mechanism70in the supply flow path21, while the valve body74is open, a predetermined negative pressure is maintained in a region from the liquid chamber73to the nozzles14. Thereby, liquid dripping from the nozzles14is suppressed and a liquid ejecting operation is stabilized.

When the drive mechanism26presses the flexible film77which is a part of the pressure adjusting mechanism70, the valve body74is forcibly opened and the inside of the nozzles14is pressurized. At this time, if there is the one-way valve27on the upstream side of the pressure adjusting mechanism70, the liquid in the liquid chamber73is prevented from flowing upstream and flows toward the downstream side. Therefore, the inside of the nozzles14is efficiently pressurized.

Liquid is temporarily retained in the supply chamber71and the liquid chamber73, so that bubbles are easily accumulated. If there are bubbles in the liquid, when the flexible film77is displaced to the inside of the liquid chamber73, the bubbles are compressed, so that the liquid becomes less pressurized. In this regard, when the filter28and the bubble chamber29aare arranged on the upstream side of the pressure adjusting mechanism70, bubbles are hardly accumulated in the supply chamber71and the liquid chamber73, so that the pressurizing force is stabilized. Further, when the one-way valve27is arranged between the liquid chamber73and the filter chamber29, the pressurizing force does not reach the bubble chamber29acontaining bubbles, so that it is possible to avoid reduction of the pressurizing force due to the presence of bubbles.

Increase in flow path resistance is suppressed by using the liquid chamber73of the pressure adjusting mechanism70also as the liquid chamber73of the pressurizing mechanism22. Further, upsizing of the apparatus is suppressed by incorporating the pressurizing mechanism22into the pressure adjusting mechanism70.

As a first modified example of the present embodiment, the one-way valve27may be modified to the opening/closing mechanism23(seeFIG. 1) that can be operated to be open and close. In this case, the opening/closing mechanism23closes the supply flow path21, and thereby the choke cleaning can be performed. When the opening/closing mechanism23closes the supply flow path21and the suction mechanism36(seeFIG. 1) is driven, a negative pressure reaches a region from the nozzles14to the opening/closing mechanism23. Therefore, it is possible to discharge the bubbles accumulated in the supply chamber71and the liquid chamber73in addition to the bubbles accumulated in the liquid ejecting head13.

As a second modified example of the present embodiment, the opening/closing mechanism24(seeFIG. 1) that can be operated to be open and close may be provided on the downstream side of the pressurizing mechanism22. In this case, it is possible to perform the choke cleaning, the pressurized cleaning, and the pressurized wiping, which are performed when the opening/closing mechanism24closes the supply flow path21.

As a third modified example of the present embodiment, the first opening/closing mechanism24(seeFIG. 1) may be provided on the downstream side of the pressure adjusting mechanism70and the pressurizing mechanism22, and instead of the one-way valve27, the second opening/closing mechanism23(seeFIG. 1) may be provided on the upstream side of the pressure adjusting mechanism70and the pressurizing mechanism22. In this case, when an elapsed time from the previous cleaning is short, the choke cleaning may be performed by closing the first opening/closing mechanism24, and when the elapsed time from the previous cleaning is long, the choke cleaning may be performed by closing the second opening/closing mechanism23.

Alternatively, after performing first choke cleaning by closing the second opening/closing mechanism23on the upstream side, second choke cleaning may be performed by closing the first opening/closing mechanism24on the downstream side. By doing so, even when bubbles flowing out from the pressure adjusting mechanism70at the first choke cleaning do not reach the outside of the nozzles14, the bubbles can be discharged to the outside of the nozzles14by the second choke cleaning. When combining and performing a plurality of types of cleaning operations in this way, it is possible to effectively discharge foreign objects such as bubbles while reducing the amount of liquid consumed by the cleaning.

As a fourth modified example of the present embodiment, a liquid chamber dedicated for the pressurizing mechanism22may be provided separately in the downstream side of the pressure adjusting mechanism70. In this case, the first opening/closing mechanism24(seeFIG. 1) may be provided on the downstream side of the liquid chamber dedicated for the pressurizing mechanism22, and the one-way valve27or the second opening/closing mechanism23(seeFIG. 1) may be provided between the liquid chamber73of the pressure adjusting mechanism70and the liquid chamber dedicated for the pressurizing mechanism22. Further, in this case, an opening/closing mechanism may be provided on the upstream side of the pressure adjusting mechanism70.

Third Embodiment

Next, a third embodiment of the liquid ejecting apparatus will be described.

As shown inFIG. 3, the liquid ejecting apparatus11of the third embodiment has substantially the same configuration as that of the liquid ejecting apparatus11of the second embodiment. However, they are different in that the liquid ejecting apparatus11of the third embodiment has a valve body76, which is attached to a proximal end of the pressure receiving member75, instead of the one-way valve27. The valve body76is attached to a side of the proximal end of the pressure receiving member75opposite to the valve body74. When the drive mechanism26presses the pressure receiving member75through the flexible film77, the valve body76closes a liquid inflow port71ato the supply chamber71.

Next, operations and effects of the liquid ejecting apparatus11of the present embodiment will be described.

In the present embodiment, the valve body76closes the inflow port71aat a timing at which the drive mechanism26performs pressurization. Therefore, liquid that contributes to the pressurization hardly flows toward the filter chamber29. Further, the valve body76is housed in the supply chamber71, so that it is possible to downsize the apparatus.

Fourth Embodiment

Next, a fourth embodiment of the liquid ejecting apparatus will be described.

As shown inFIG. 4, the liquid ejecting apparatus11of the present embodiment includes the liquid ejecting head13, the supply flow path21, the pressurizing mechanism22that can pressurize the inside of the supply flow path21, the opening/closing mechanism24that can open and close the supply flow path21on the downstream side of the pressurizing mechanism22, the wiping member32, the control100that controls the liquid ejecting head13and the pressurizing mechanism22, and a clocking unit101.

The clocking unit101clocks a time elapsed from when a maintenance operation that causes the liquid ejecting head13to eject liquid is performed. The maintenance operation mentioned here is a maintenance operation effective to discharge bubbles. For example, the maintenance operation is the suction cleaning described in the first embodiment (the choke cleaning is more preferable). In the present embodiment, the maintenance operation is referred to as a “bubble discharging operation”.

The pressurizing mechanism22includes the liquid chamber73provided in the middle of the supply flow path21and the drive mechanism26that pressurizes the liquid chamber73from the outside of the supply flow path21. At least a part of the wall surface of the liquid chamber73includes the flexible film77that can be bent and displaced, and the drive mechanism26is configured to displace the flexible film77. When the drive mechanism26presses the flexible film77from the outside of the liquid chamber73toward the inside of the liquid chamber73, the pressurizing mechanism22pressurizes the inside of the supply flow path21.

An energizing member79that energizes the flexible film77to the outside may be provided in the liquid chamber73. In this case, when the drive mechanism26stops pressing the flexible film77, the energizing force of the second energizing member79can restore the flexible film77to the original position (a position shown by a solid line inFIG. 4) from a position shown by a chain double-dashed line inFIG. 4.

When the opening/closing mechanism24is a first opening/closing mechanism24, it is preferable that the liquid ejecting apparatus11includes a second opening/closing mechanism23that is an opening/closing mechanism23that can open and close the supply flow path21on the upstream side of the pressurizing mechanism22. When the second opening/closing mechanism23closes the supply flow path21while the pressurizing mechanism22pressurizes the inside of the supply flow path21, the liquid hardly flows back upstream. Therefore, a pressurizing force generated in association with the displacement of the flexible film77is concentrated to the nozzles14located in the downstream side.

The liquid ejecting head13has a plurality of (for example, four) nozzle groups, each of which includes a plurality of nozzles14that eject the same type of liquid (for example, ink of the same color). The liquid ejecting head13includes cavities15that respectively communicate with the nozzles14and a common liquid chamber16that communicates with the plurality of cavities15. The common liquid chamber16is provided for each nozzle group.

The pressure in the liquid ejecting head13is also an internal pressure of the cavity15or the common liquid chamber16. In a space where liquid is temporarily accumulated, such as the cavity15or the common liquid chamber16, a region occurs where liquid hardly flows, so that foreign objects such as bubbles are easily accumulated in the region.

Next, the pressurized wiping of the present embodiment will be described with reference toFIGS. 5 and 6.

InFIG. 5, a pressure variation in the liquid ejecting head13is shown as a graph110, a driving state of the pressurizing mechanism22is shown as a graph111, an opening/closing state of the second opening/closing mechanism23is shown as a graph112, an opening/closing state of the first opening/closing mechanism24is shown as a graph113, and an operating state of the wiping member32is shown as a graph114.

When the bubble discharging operation is performed, the clocking unit101starts clocking of an elapsed time Tc. Thereafter, a printing operation and the like are performed and the control unit100performs the pressurized wiping shown inFIG. 6at a predetermined timing.

First, as step S11, the first opening/closing mechanism24and the second opening/closing mechanism23close the supply flow path21. At the same time as step S11or immediately after step S11, as step S12, the drive mechanism26drives and presses the flexible film77, so that the pressurizing mechanism22starts pressurizing the inside of the supply flow path21. At this time, the first opening/closing mechanism24and the second opening/closing mechanism23close the supply flow path21, so that a region between the first opening/closing mechanism24and the second opening/closing mechanism23is pressurized.

Subsequently, as step S13, the first opening/closing mechanism24opens the supply flow path21. Then, the pressurizing force reaches the downstream side of the first opening/closing mechanism24, so that the pressure in the liquid ejecting head13rises. The pressurizing force at this time is set so as to exceed a threshold value Pm (seeFIG. 5). The threshold value Pm is determined so that when the pressure in the nozzle14exceeds the threshold value Pm, the liquid surface protrudes to the outside of the nozzle14and the meniscus is broken. A peak value of the pressure when the meniscus is broken is defined as Pc (seeFIG. 5).

As step S14, the control unit100waits for a predetermined period of time (for example, a waiting time Tp). The waiting time Tp at this time (seeFIG. 5) may be set as a required time within which the pressure in the nozzle14exceeds the threshold value Pm by the pressurization and as shown by a chain double-dashed line inFIG. 4, the meniscus protruding to the outside of the nozzle14is broken and liquid wet-spreads on the opening surface13a. When the meniscus is broken and the liquid is beginning to flow out of the nozzle14, the pressure in the liquid ejecting head13is beginning to fall from a peak value Pc.

Thereafter, as step S15, the first opening/closing mechanism24closes the supply flow path21. Then, the pressurizing force does not reach the liquid ejecting head13and the pressure in the liquid ejecting head13rapidly falls in association with the leakage of liquid from the nozzles14. When the pressure in the liquid ejecting head13becomes close to the atmospheric pressure, liquid does not flow out of the nozzles14.

Subsequently, as step S16, the drive mechanism26stops driving to stop the pressurization. Further, as step S17, the second opening/closing mechanism23opens the supply flow path21. Steps S16and S17may be performed at the same time as step S15.

As step S18, the control unit100waits again (second wait). The length of the waiting time at this time is defined as a waiting time Tw (seeFIG. 5).

Thereafter, as step S19, the wiping member32performs the wiping. When the wiping is completed, the process proceeds to step S20, the first opening/closing mechanism24opens the supply flow path21, and the process is completed.

Here, a case1shown by a solid line inFIG. 5illustrates variation of the pressure in the liquid ejecting head13when the elapsed time Tc from the bubble discharging operation is short and there are little bubbles in the liquid ejecting head13. On the other hand, a case2shown by a dashed line inFIG. 5illustrates variation of the pressure in the liquid ejecting head13when the elapsed time Tc from the bubble discharging operation is longer than that in the case1and there are many bubbles in the liquid ejecting head13.

In the case2, a volume change caused when the bubbles are compressed by the pressurization force is large, so that the pressure in the liquid ejecting head13more hardly rises than in the case1in a period from when the first opening/closing mechanism24opens the supply flow path21in step S13to when the meniscus is broken. Further, in the case2, a volume change is large, which is caused when bubbles expand, which were compressed after the first opening/closing mechanism24closes the supply flow path21in step S15, so that it takes a longer time for the pressure in the liquid ejecting head13falls than in the case1.

When the wiping is performed before the pressure in the liquid ejecting head13falls sufficiently, liquid flows out of the nozzles14even after the wiping is performed, so that liquid is attached to the opening surface13aagain. Therefore, it is preferable to start the wiping after the pressure in the liquid ejecting head13becomes close to the atmospheric pressure.

On the other hand, when it takes a long time from when the pressure in the liquid ejecting head13falls close to the atmospheric pressure to when the wiping is performed, liquids that wet-spread on the opening surface13aare mixed. When it is configured so that a plurality of nozzles14eject different types of liquids, different types of liquids enter a nozzle14. When the liquids are inks of different colors, there is a risk that the inks are mixed in the nozzle14to cause degradation of print quality. It is necessary to discharge liquid containing different types of liquids by a maintenance operation such as flashing, so that when mixing of liquids progresses, a large amount of liquid is consumed to discharge the mixed liquids. Therefore, after the pressure in the liquid ejecting head13becomes lower than a predetermined value, it is preferable to start the wiping as soon as possible.

For example, the nozzle14has a small caliber, so that the flow path resistance is large. Therefore, even when the pressure in the liquid ejecting head13is higher than the atmospheric pressure, if the pressure in the liquid ejecting head13becomes lower than a predetermined threshold value Pb (seeFIG. 5), the liquid hardly flows out of the nozzles14. Thus, the wiping may be started when the pressure in the liquid ejecting head13becomes lower than the threshold value Pb. The threshold value Pb is a value that varies according to the caliber and the length of the nozzle14. When the pressure in the liquid ejecting head13becomes higher than the threshold value Pb, liquid oozes from the nozzle14.

Therefore, the waiting times Tp and Tw may be changed according to the amount of bubbles, that is, the elapsed time Tc that is clocked by the clocking unit101. For example, it is preferable that the shorter the elapsed time Tc, the shorter the waiting times Tp and Tw that are set by the control unit100.

As an essential point of the present embodiment, after the pressurizing mechanism22pressurizes the inside of the supply flow path21, the control unit100may cause the wiping member32to perform the wiping after elapsing a time within which an appropriate amount of liquid flows out of the nozzles14. Therefore, after omitting steps S11, S13, S15, S17, and S20and causing the pressurizing mechanism22to perform pressurization, the control unit100may cause the wiping member32to perform the wiping after waiting for a specified period of time (for example, Tp+Tw). The “specified period of time” is a period of time in consideration of a period of time required to discharge pressurized liquid from the nozzles14(the waiting time Tw) in addition to a predetermined period of time required for the liquid to wet-spread on the opening surface13a(the waiting time Tp).

However, when the pressurizing mechanism22pressurizes the inside of the supply flow path21in a state in which the first opening/closing mechanism24closes the supply flow path21and thereafter the first opening/closing mechanism24opens the supply flow path21, it is possible to cause the pressurizing force to reach downstream in a short period of time. When a rapid pressure change is caused by pressurization, bubble dischargeability is improved.

When the amount of bubbles is small, the pressurizing force reaches the liquid more easily than when the amount of bubbles is large, so that the threshold value Pm can be exceeded by a smaller force. Therefore, the control unit100may change the pressurizing force of the pressurizing mechanism22in accordance with the elapsed time Tc. For example, the control unit100may change the pressurizing force of the pressurizing mechanism22so that the shorter the elapsed time Tc, the smaller the pressurizing force. Alternatively, the control unit100may change at least one of the pressurizing force of the pressurizing mechanism22and the waiting times Tp and Tw in accordance with the elapsed time Tc. In addition, the control unit100may change the pressurizing force or the waiting times Tp and Tw in accordance with the environmental temperature, the viscosity of the liquid, or the like.

The pressurized wiping of the present embodiment can be performed in the liquid ejecting apparatus11of the other embodiments. Further, it is possible to change a relationship between the elapsed time Tc and the pressurizing force of the pressurizing mechanism22or a relationship between the elapsed time Tc and the waiting times Tp and Tw in accordance with types of cleanings. For example, the bubble dischargeability of the choke cleaning is higher than that of normal suction cleaning. Therefore, even when the elapsed time Tc after the choke cleaning is performed is longer than the elapsed time Tc after the normal suction cleaning is performed, the pressurizing force or the waiting times Tp and Tw may be changed by assuming that the amount of bubbles after the choke cleaning is small.

In addition, when the choke cleaning is performed, bubbles are discharged. Therefore, the amount of bubbles may be estimated based on elapsed time from the choke cleaning. Alternatively, the amount of bubbles may be estimated based on a measurement result of a pressure sensor not shown in the drawings.

Fifth Embodiment

Next, a fifth embodiment of the liquid ejecting apparatus will be described.

As shown inFIG. 7, the liquid ejecting apparatus11of the present embodiment includes the liquid ejecting head13, the supply flow path21, the first opening/closing mechanism24and the second opening/closing mechanism23that can open and close the supply flow path21, the pressure adjusting mechanism70provided in the supply flow path21between the first opening/closing mechanism24and the second opening/closing mechanism23, and the pressurizing mechanism22that shares some components with the pressure adjusting mechanism70. In the supply flow path21, at least a portion where the first opening/closing mechanism24is arranged is formed of a flexible tube.

The first opening/closing mechanism24of the present embodiment has a pressing body24athat can squeeze a tube21aand a moving mechanism24bthat moves the pressing body24aalong the tube21a. The pressing body24ais, for example, a pair of rollers. When the pair of rollers pinch and squeeze the tube21a, the supply flow path21is closed. When the pair of rollers stop the squeezing, the supply flow path21is opened. In the first opening/closing mechanism24, the pair of rollers move along the tube21ain a state in which the pair of rollers close the supply flow path21, so that it is possible to move a closed position Cp of the supply flow path21.

Next, the pressurized wiping of the present embodiment will be described with reference toFIGS. 8 and 9.

InFIG. 8, graph1shows variation of the pressure of the liquid in the liquid ejecting head13(the variation is shown by a solid line inFIG. 8), and graph2shows variation of the size of the bubbles in the liquid ejecting head13(the variation is shown by a dashed-dotted line inFIG. 8).FIG. 9shows control performed by the control unit100.

First, in the same manner as in the fourth embodiment, the first opening/closing mechanism24and the second opening/closing mechanism23close the supply flow path21(step S11) and the pressurizing mechanism22starts pressurizing the inside of the supply flow path21(step S12).

Subsequently, when the first opening/closing mechanism24opens the supply flow path21(step S13), the pressure in the liquid ejecting head13rises. The bubbles in the liquid ejecting head13are compressed in accordance with the pressure rise, and the size of the bubbles decreases. While waiting for a predetermined period of time (the waiting time Tp) (step S14), when the pressure in the liquid ejecting head13reaches a peak value Pc, the meniscus of the nozzle14is broken and the liquid wet-spreads on the opening surface13a. When the meniscus of the nozzle14is broken, the liquid flows out of the nozzle14, the pressure in the liquid ejecting head13falls and the size of the babbles in the liquid ejecting head13increases.

Thereafter, when the first opening/closing mechanism24closes the supply flow path21(step S15), the pressure in the liquid ejecting head13further falls as the pressurized liquid flows out of the nozzles14. The size of the bubbles in the liquid ejecting head13further increases as the pressure in the liquid ejecting head13falls. As the size of the bubbles increases, the amount of liquid flowing out from the nozzles14increases. Thereafter, the pressurizing mechanism22stops the pressurization (step S16) and the second opening/closing mechanism23opens the supply flow path21(step S17). Steps S16and S17may be performed at the same time as step S15.

Subsequently, the first opening/closing mechanism24moves the closed position Cp to an upstream region of the supply flow path21(step S19). After the first opening/closing mechanism24moves the closed position Cp, the wiping member32wipes the opening surface13a(step S21). Thereafter, the first opening/closing mechanism24opens the supply flow path21(step S20), and the process is completed.

Next, operations and effects of the present embodiment will be described.

In the pressurized wiping of the present embodiment, the pressurizing mechanism22pressurizes the inside of the supply flow path21in a state in which the opening/closing mechanisms23and24close the supply flow path21, and thereafter, the first opening/closing mechanism24performs an opening/closing operation that temporarily opens the supply flow path21and closes the supply flow path21again, and the first opening/closing mechanism24moves the closed position Cp to an upstream region of the supply flow path21in a state in which the opening/closing mechanism24still closes the supply flow path21. Thereafter, the wiping member32wipes the opening surface13a. Therefore, when the wiping member32wipes the opening surface13a, the liquid flown out of the nozzles14is attached to the opening surface13a, so that it is possible to efficiently clean the opening surface13a. At this time, the first opening/closing mechanism24closes the supply flow path21, so that the liquid is not easily flown out unnecessarily during the wiping and foreign objects such as bubbles are not easily drawn into the nozzles14.

Further, in the present embodiment, the first opening/closing mechanism24moves the closed position Cp to an upstream region of the supply flow path21in step S19, so that the pressure in the liquid ejecting head13quickly falls without liquid flowing out from the nozzles14. Thereby, it is possible to prevent the liquid from unnecessarily flowing out due to pressurization. Further, it is not necessary to wait for falling of the pressure in the liquid ejecting head13before the wiping (the second wait in step S18in the fourth embodiment), and accordingly the maintenance time is shortened.

When the first opening/closing mechanism24does not move the closed position Cp to an upstream region and gradually releases the pressurization in accordance with leakage of the liquid (shown by a chain double-dashed line in graph1), the size of the bubbles that are compressed by the pressurization gradually increases in accordance with the release of the pressurization (shown by a chain double-dashed line in graph2), so that the amount of leaked liquid increases.

As a modified example of the present embodiment, the liquid chamber22a(seeFIG. 1) whose inside can be opened to the atmosphere is arranged between the second opening/closing mechanism23and the first opening/closing mechanism24in the supply flow path21, and the pressurization may be performed by sending gas to the inside of the liquid chamber22aby means of the drive mechanism25.

In the fifth embodiment and the modified example described above, instead of the second opening/closing mechanism23, the one-way valve27(seeFIG. 2) may be arranged on the upstream side of the pressurizing mechanism22.

Sixth Embodiment

Next, a sixth embodiment of the liquid ejecting apparatus will be described.

As shown inFIGS. 10 and 11, the liquid ejecting apparatus11of the present embodiment includes an opening/closing mechanism41that can open and close the supply flow path21. The opening/closing mechanism41has a pressing body42that can squeeze a portion of a flexible tube21aof the supply flow path21and a moving mechanism43that moves the pressing body42along the tube21a.

The pressing body42is, for example, an eccentric cam. The pressing body42has a rotating shaft43athat can rotate the pressing body42, which is an eccentric cam. The pressing body42squeezes the tube21aand thereby the opening/closing mechanism41closes the supply flow path21. A position of the pressing body42shown by a chain double-dashed line inFIGS. 10 and 11is a first closed position that closes the supply flow path21. A position of the pressing body42shown by a solid line inFIG. 11is a second closed position that closes the supply flow path21. The pressing body42that squeezes the supply flow path21rotates in a counterclockwise direction shown by an arrow inFIG. 10between the first closed position and the second closed position or in a clockwise direction (direction shown by an arrow inFIG. 11) opposite to the counterclockwise direction, and thereby the opening/closing mechanism41moves the closed position Cp in a state in which the supply flow path21is closed. The direction in which the pressing body42rotates from the first closed position to the second closed position is a direction toward the downstream side of the supply flow path21.

The tube21ais an elliptical ring and may be arranged so that the pressing body42can rotate to a retreat position where the pressing body42does not squeeze the tube21a(a position shown by a solid line inFIG. 10). When the liquid ejecting head13ejects liquid to the medium S, the pressing body42is disposed at the retreat position and liquid is flown through the supply flow path21.

Next, the pressurized wiping of the present embodiment will be described with reference toFIGS. 10, 11, and12.FIG. 12shows control performed by the control unit100.

First, as step S22, the pressing body42rotates from the retreat position to the first closed position and closes the supply flow path21. Next, as step S23, the pressing body42rotates from the first closed position to the second closed position and thereby moves the closed position Cp to the downstream side of the supply flow path21. Thereby, the inside of the liquid ejecting head13is pressurized.

After the opening/closing mechanism41moves the closed position Cp to the downstream side in this way, as step S19, the pressing body42rotates from the second closed position to the first closed position in the clockwise direction shown by the arrow inFIG. 11, so that the opening/closing mechanism41moves the closed position Cp to the upstream side of the supply flow path21. Thereby, the pressure in the liquid ejecting head13falls without outputting liquid from the nozzles14. Thereafter, as step S21, the wiping member32wipes the opening surface13a. After the wiping member32wipes the opening surface13a, as step S24, the pressing body42rotates from the first closed position to the retreat position and thereby the opening/closing mechanism41opens the supply flow path21, and the process is completed.

According to the liquid ejecting apparatus11of the present embodiment, the opening/closing mechanism41has a function to perform pressurization, so that it is not necessary to have a pressurizing mechanism separately. Accordingly, the configuration can be simplified.

The pressurized wiping of the fourth to the sixth embodiment can be performed as the pressurized cleaning.

Seventh Embodiment

Next, a seventh embodiment of the liquid ejecting apparatus will be described.

In the seventh embodiment, another form of an opening/closing mechanism that can be used for the pressurized wiping and the pressurized cleaning of the fourth to the sixth embodiments will be illustrated.

As shown inFIG. 13, the opening/closing mechanism41of the present embodiment includes a support portion44that supports the tube21athat is a part of the supply flow path21, a roller that is an example of the pressing body42, a holding member45that rotatably holds the pressing body42, and a guide portion46that engages with the holding member45. The guide portion46has an inclined guide46athat obliquely extends with respect to a gravitational direction. The holding member45has an engaging portion45athat engages with the inclined guide46a.

During printing or the like, as shown inFIG. 13, the guide portion46and the holding member45are arranged in a position where the pressing body42does not squeeze the tube21a. When the guide portion46falls from the position shown inFIG. 13, the holding member45engaging with the guide portion46and the pressing body42held by the holding member45also fall.

As shown inFIG. 14, when the pressing body42moves to a position where the pressing body42squeezes the tube21a, the opening/closing mechanism41closes the supply flow path21(step S22inFIG. 12). When the guide portion46further falls from the position shown inFIG. 14, the engaging portion45ais guided by the inclined guide46a, and thereby the holding member45and the pressing body42move in a first direction indicated by an arrow inFIG. 15. In this way, in a state in which the pressing body42still squeezes the tube21a, the pressing body42moves from a first closed position shown by a chain double-dashed line inFIG. 15to a second closed position shown by a solid line inFIG. 15, and thereby the closed position Cp moves downstream (step S23inFIG. 12).

Thereafter, when the guide portion46moves upward from the position shown inFIG. 15to the position shown inFIG. 14, the engaging portion45ais guided by the inclined guide46a, and thereby the holding member45and the pressing body42move in a second direction opposite to the first direction. In this way, in a state in which the pressing body42still squeezes the tube21a, the pressing body42moves from the second closed position shown by the solid line inFIG. 15to the first closed position shown by the chain double-dashed line inFIG. 15, and thereby the closed position Cp moves upstream (step S19inFIG. 12).

Subsequently, when the guide portion46moves upward from the position shown inFIG. 14to the position shown inFIG. 13, the pressing body42stops squeezing the tube21a, so that the supply flow path21is opened (step S24inFIG. 12)

Eighth Embodiment

Next, an eighth embodiment of the liquid ejecting apparatus will be described.

In the eighth embodiment, another form of an opening/closing mechanism that can be used for the pressurized wiping and the pressurized cleaning of the sixth embodiment will be illustrated.

As shown inFIG. 16, the opening/closing mechanism41of the present embodiment includes the support portion44that supports the tube21a, a roller that is an example of the pressing body42, the holding member45that rotatably holds the pressing body42, and a guide shaft47that engages with the holding member45. The support portion44and the guide shaft47are arranged so as to extend along the tube21a.

During printing or the like, as shown by a solid line inFIG. 16, the holding member45is arranged in a position where the pressing body42does not squeeze the tube21a. When the holding member45falls from a position shown by a solid line inFIG. 16to a position shown by a chain double-dashed line inFIG. 16, the pressing body42squeezes the tube21a. Thereby, the opening/closing mechanism41closes the supply flow path21(step S22inFIG. 12). The closed position Cp at this time is referred to as a first closed position.

In a state in which the pressing body42still squeezes the tube21aas shown by a solid line inFIG. 17, when the holding member45moves from the first closed position (a position shown by a solid line inFIG. 17) to a second closed position shown by a chain double-dashed line in a first direction indicated by an arrow inFIG. 17along the guide shaft47, the closed position Cp moves downstream (step S23inFIG. 12).

In a state in which the pressing body42still squeezes the tube21a, when the holding member45moves from the second closed position to the first closed position along the guide shaft47in a second direction opposite to the first direction, the closed position Cp moves upstream (step S19inFIG. 12). Thereafter, when the holding member45rises and the pressing body42stops the squeezing of the tube21a, the supply flow path21is opened (step S24inFIG. 12).

MODIFIED EXAMPLES

In addition, each embodiment described above may be modified to the modified examples described below. Components included in the above embodiments and components included in the modified examples described below may be arbitrarily combined, or components included in the modified examples described below may be arbitrarily combined.

The opening/closing mechanism41of the sixth to the eighth embodiments may be used as the first opening/closing mechanism24for performing the pressurized wiping and the pressurized cleaning of the fifth embodiment. Further, the first opening/closing mechanism24of the fifth embodiment may be used as the opening/closing mechanism41of the sixth to the eighth embodiments.

The liquid ejected from the liquid ejecting head13is not limited to ink. For example, the liquid may be a liquid state material where particles of functional materials are dispersed or mixed in a liquid. For example, a liquid state material, where materials such as an electrode material and color materials (pixel materials) used for manufacturing a liquid crystal display, an EL (electroluminescence) display, and a surface-emitting display are dispersed or dissolved, may be ejected to perform recording.

The medium S is not limited to a paper sheet, but may be a plastic film or a thin plate material, or may be a fabric used by a fabric printing apparatus. Further, the medium S may be clothes of an arbitrary shape such as T-shirt or may be a three-dimensional object of an arbitrary shape such as tableware or stationery.

Hereinafter, technical ideas grasped from the above embodiments and modified examples and the effects thereof will be described.

A liquid ejecting apparatus including a liquid ejecting head having nozzles and an opening surface through which the nozzles are opened, the liquid ejecting head being configured to eject liquid from the nozzles, a supply flow path configured to supply the liquid to the liquid ejecting head, a pressurizing mechanism that can pressurize inside of the supply flow path, an opening/closing mechanism that can open and close the supply flow path, and a control unit that controls operations of the liquid ejecting head, the pressurizing mechanism, and the opening/closing mechanism.

The liquid ejecting apparatus described in the [Idea 1], wherein the opening/closing mechanism is provided on a downstream side from the pressurizing mechanism, and the control unit causes the opening/closing mechanism to close the supply flow path, causes the pressurizing mechanism to pressurize the inside of the supply flow path, and thereafter causes the opening/closing mechanism to open the supply flow path, and then causes the opening/closing mechanism to close the supply flow path after a predetermined period of time elapses.

According to the [Idea 2] described above, when the opening/closing mechanism opens the supply flow path that is pressurized by the pressurizing mechanism, pressurized liquid flows out of the nozzles. Thereby, it is possible to efficiently discharge foreign objects and the like in the nozzles. Since the opening/closing mechanism closes the supply flow path after a predetermined period of time elapses, it is possible to prevent the liquid from unnecessarily flowing out due to pressurization.

The liquid ejecting apparatus described in the [Idea 2], further including a wiping member that can wipe the opening surface. In the liquid ejecting apparatus, after the opening/closing mechanism closes the supply flow path, the wiping member wipes the opening surface.

According to the [Idea 3] described above, when the wiping is performed, the liquid flown out of the nozzles is attached to the opening surface, so that it is possible to efficiently clean the opening surface. At this time, the supply flow path is closed, so that the liquid is not easily flown out unnecessarily during the wiping and foreign objects such as bubbles are not easily drawn into the nozzles.

The liquid ejecting apparatus described in any one of the [Idea 1] to the [Idea 3], in which the pressurizing mechanism includes a liquid chamber provided in the middle of the supply flow path and a drive mechanism that pressurizes the liquid chamber from outside the supply flow path.

According to the [Idea 4] described above, the drive mechanism is located outside the liquid chamber, so that the structure of the supply flow path is less likely to be complicated.

The liquid ejecting apparatus described in the [Idea 4], in which at least a part of a wall surface of the liquid chamber includes a flexible film that can be displaced, and the drive mechanism is configured to displace the flexible film.

According to the [Idea 5] described above, it is possible to pressurize the inside of the supply flow path when the drive mechanism displaces the flexible film to the inside of the liquid chamber.

The liquid ejecting apparatus described in the [Idea 5], further including a valve body that opens and closes the supply flow path by interlocking with displacement of the flexible film.

According to the [Idea 6] described above, it is possible to interlock a pressurizing operation with an opening/closing operation of the supply flow path.

The liquid ejecting apparatus described in the [Idea 4], in which inside of the liquid chamber is configured to be able to be opened to the atmosphere, and the drive mechanism is configured to send gas to the inside of the liquid chamber.

According to the [Idea 7] described above, the drive mechanism sends gas to the inside of the liquid chamber, and thereby the supply flow path is pressurized, and the pressurization is released by opening the inside of the liquid chamber22ato the atmosphere.

The liquid ejecting apparatus described in any one of the [Idea 1] to the [Idea 7], further including a second opening/closing mechanism that can open and close the supply flow path on the upstream side from the pressurizing mechanism when the opening/closing mechanism is used as a first opening/closing mechanism. In the liquid ejecting apparatus, the pressurizing mechanism pressurizes the inside of the supply flow path in a state in which the first opening/closing mechanism and the second opening/closing mechanism close the supply flow path.

According to the [Idea 8] described above, the liquid hardly flows back upstream during pressurization.

The liquid ejecting apparatus described in any one of the [Idea 1] to the [Idea 7], further including a one-way valve which is arranged on the upstream side from the pressurizing mechanism in the supply flow path and which allows a flow of the liquid to a downstream side and restricts a flow of the liquid to an upstream side.

According to the [Idea 9] described above, the liquid hardly flows back upstream during pressurization.

The liquid ejecting apparatus described in any one of the [Idea 1] to the [Idea 7], wherein the pressurizing mechanism includes a liquid chamber provided in the middle of the supply flow path, and the liquid ejecting apparatus further includes a filter arranged upstream from the liquid chamber in the supply flow path, a pressure adjusting valve which is arranged in the supply flow path between the filter and the liquid chamber and which can open and close so as to adjust pressure of the liquid supplied to the liquid ejecting head, and a one-way valve which is arranged in the supply flow path between the pressure adjusting valve and the filter and which allows a flow of the liquid to a downstream side and restricts a flow of the liquid to an upstream side.

According to the [Idea 10] described above, the liquid hardly flows back upstream during pressurization.

A maintenance method of a liquid ejecting apparatus that includes a liquid ejecting head having nozzles and an opening surface through which the nozzles are opened, the liquid ejecting head being configured to eject liquid from the nozzles, a supply flow path configured to supply the liquid to the liquid ejecting head, a pressurizing mechanism that can pressurize the inside of the supply flow path, an opening/closing mechanism that can open and close the supply flow path on a downstream side from the pressurizing mechanism, and a control unit that controls operations of the liquid ejecting head, the pressurizing mechanism, and the opening/closing mechanism, the maintenance method including a first closing step in which the control unit operates the opening/closing mechanism to close the supply flow path, a pressure increasing step in which the control unit operates the pressurizing mechanism to increase pressure in the supply flow path, an opening step in which the control unit operates the opening/closing mechanism to open the supply flow path after the pressure increasing step, and a second closing step in which the control unit closes the supply flow path after a predetermined time elapses from the opening step.

According to the [Idea 11] described above, when the opening/closing mechanism opens the supply flow path that is pressurized by the pressurizing mechanism, pressurized liquid flows out of the nozzles. Thereby, it is possible to efficiently discharge foreign objects and the like in the nozzles. Since the opening/closing mechanism closes the supply flow path after a predetermined period of time elapses, it is possible to prevent the liquid from unnecessarily flowing out due to pressurization.

The entire disclosure of Japanese Patent Application No. 2016-238822, filed Dec. 8, 2016 is expressly incorporated by reference herein.