JP2016112805A - Liquid jetting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jetting device capable of reducing down-time of jetting operation of liquid caused in response to execution of agitation operation of the liquid.SOLUTION: A control part of a liquid jetting device executes agitation operation when a sedimentation degree Sd is a first threshold value Th1 or more (S21 : YES, S23), and executes jetting operation when the sedimentation degree Sd is less than a second threshold value Th2 larger than the first threshold value Th1 (S19 : YES, S20). The control part preferentially executes the jetting operation when the sedimentation degree Sd is the first threshold value Th1 or more and less than the second threshold value Th2 (S20).SELECTED DRAWING: Figure 4

Description

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

  2. Description of the Related Art Conventionally, as an example of a liquid ejecting apparatus, an ink jet printer that performs a printing operation for printing characters and images on a medium such as paper by ejecting ink as an example of a liquid contained in a liquid container onto a medium such as paper It has been known.

  Some printers perform an agitation operation for agitating the ink stored in the liquid storage unit in order to improve the ink density difference caused by the sedimentation of the pigment particles in the ink inside the liquid storage unit. Some have a stirring section (for example, Patent Document 1).

JP 2011-240687 A

  By the way, in the printer as described above, when a predetermined stirring condition is satisfied, for example, when a predetermined period has elapsed since the previous stirring operation, the current stirring operation is performed. For this reason, while the stirring condition is satisfied, the printing operation cannot be performed while the stirring operation is performed. Therefore, in such a printer, a time (downtime) in which the printing operation cannot be performed occurs with the execution of the stirring operation.

  Note that the above situation is not limited to printers that perform printing operations using ink containing pigment particles, but is generally common to liquid ejecting apparatuses that perform ejection operations that eject liquid containing particles that can settle. .

  The present invention has been made in view of the above circumstances. An object of the present invention is to provide a liquid ejecting apparatus capable of reducing the downtime of the liquid ejecting operation that occurs in accordance with the execution of the liquid stirring operation.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A liquid ejecting apparatus that solves the above-described problem performs a liquid ejecting unit that performs an ejecting operation for ejecting a liquid contained in a liquid containing unit toward a medium, and an agitating operation for stirring the liquid contained in the liquid containing unit. The agitation unit, a determination unit that determines a sedimentation degree that increases as the particles contained in the liquid contained in the liquid accommodation part settle, and the agitation operation when the sedimentation degree is equal to or greater than a first threshold value. A control unit that executes the injection operation when the sedimentation degree is less than a second threshold value that is greater than the first threshold value, and the control unit has the sedimentation degree of the first threshold value. When the value is equal to or greater than the threshold value and less than the second threshold value, the injection operation is performed with priority over the stirring operation.

  According to the above configuration, when the sedimentation degree of the liquid stored in the liquid storage unit is less than the first threshold, the particles have settled to such an extent that the liquid stored in the liquid storage unit is not suitable for the ejection operation. If there is no injection, the injection operation is executed. On the other hand, when the sedimentation degree of the liquid stored in the liquid storage unit is equal to or higher than the second threshold, the stirring operation is performed assuming that the particles are settled to such an extent that the liquid stored in the liquid storage unit is not suitable for the ejection operation. Is executed.

  When the sedimentation degree is equal to or higher than the first threshold value and lower than the second threshold value, the injection operation is performed with priority over the stirring operation. For this reason, when the sedimentation degree is equal to or higher than the first threshold value and lower than the second threshold value, when the injection operation needs to be executed, the injection operation is executed without waiting for the execution of the stirring operation. Can do. Therefore, it is possible to reduce a period (down time) during which the liquid ejecting operation that occurs with the execution of the liquid stirring operation cannot be performed.

  In the liquid ejecting apparatus, in the case where the ejecting operation is performed during the execution of the stirring operation, the control unit interrupts the execution of the stirring operation when the sedimentation degree is less than the second threshold value. It is desirable that the agitation operation be continued when the subsidence is equal to or greater than the second threshold.

  According to the above configuration, when the sedimentation degree is equal to or greater than the second threshold value and the injection operation cannot be performed immediately, the stirring operation is first performed. Then, the execution of the stirring operation is interrupted and the injection operation is performed at the timing when the settling degree becomes less than the second threshold value with the execution of the stirring operation. That is, even when the stirring operation is being executed, the injection operation can be interrupted and executed at the timing when the injection operation can be executed. For this reason, since the injection operation can be executed without waiting for the completion of the stirring operation until the settling degree becomes less than the first threshold value, the injection operation is performed even when the settling degree is equal to or more than the second threshold value. Downtime can be reduced.

  In the liquid ejecting apparatus, when the execution of the stirring operation is interrupted in order to execute the ejecting operation, the control unit restarts the execution of the stirring operation after the execution of the ejecting operation is completed. It is desirable to change the stirring intensity in the restarted stirring operation according to the execution content of the injection operation.

  For example, depending on the liquid ejection mode of the liquid ejection unit and the liquid supply mode from the liquid storage unit to the liquid ejection unit, the liquid in the liquid storage unit may flow strongly or weakly during the ejection operation. That is, the liquid ejecting operation may affect the sedimentation degree of the liquid container.

  According to the above configuration, the stirring intensity when resuming the suspended stirring operation is changed based on the influence of the liquid jetting operation on the sedimentation degree of the liquid container. For this reason, even when the injection operation is interrupted during the stirring operation, the liquid container is settled even if the restarted stirring operation is performed with a stirring intensity more than necessary or the restarted stirring operation is performed. It can be suppressed that the degree cannot be improved.

  In the liquid ejecting apparatus, when the execution of the stirring operation is interrupted in order to execute the ejecting operation, the control unit restarts the execution of the stirring operation after the execution of the ejecting operation is completed. It is desirable to change according to the execution content of the stirring operation in which the stirring intensity in the restarted stirring operation is interrupted.

  In the case where the injection operation is interrupted immediately after execution of the stirring operation and the case where the injection operation is executed immediately before the end of execution of the stirring operation, which of the stirring operations is resumed after the execution of the injection operation is completed. It is different whether it should be executed with a stirring intensity of a degree.

  According to the said structure, the stirring intensity | strength when restarting the suspended stirring operation is changed according to the execution content of the suspended stirring operation. For this reason, even when the injection operation is interrupted during the stirring operation, the liquid container is settled even if the restarted stirring operation is performed with a stirring intensity more than necessary or the restarted stirring operation is performed. It can be suppressed that the degree cannot be improved.

  In the liquid ejecting apparatus, when the settling degree is equal to or higher than a second threshold during the ejection operation, the control unit interrupts the performance of the ejection operation and performs the agitation operation. It is desirable to make it.

  According to the above configuration, since the stirring operation is interrupted even during the execution of the injection operation, the execution of the injection operation is continued in a state where the sedimentation degree is equal to or higher than the second threshold value. Can be suppressed. For this reason, it is possible to prevent the ejection operation from being performed in a state where the particles are settled to such an extent that they are not suitable for the liquid ejection in the liquid storage portion.

In the liquid ejecting apparatus, it is preferable that the determination unit determines the sedimentation degree based on a type of liquid stored in the liquid storage unit.
For example, when the viscosity of a liquid (a solvent of the same liquid) stored in the liquid storage unit is high, particles contained in the liquid are less likely to settle than when the viscosity is low. In addition, when the size (particle diameter) of the particles contained in the liquid contained in the liquid containing portion is small, the particles contained in the liquid are less likely to settle than when the size of the particles is large. That is, depending on the type of liquid, the sedimentation degree may change in a different manner.

  In this regard, according to the above configuration, since the sedimentation degree is determined based on the type of liquid, each of the liquid ejecting apparatuses may include a plurality of liquid storage units that store different types of liquid. The stirring operation can be executed at an appropriate timing with respect to the liquid container.

In the liquid ejecting apparatus, it is preferable that the determination unit determines that the settling degree is larger when the period during which the stirring operation is not performed is longer than when the period of synchronization is short.
For example, the longer the period of time during which the stirring operation is not performed, such as when the elapsed time since the liquid storage portion was manufactured is longer, or when the elapsed time since the most recent stirring operation was performed is longer, Many particles are expected to settle in the area. According to the above configuration, since the settling degree is determined to be larger as the period during which the stirring operation is not performed is longer, the stirring operation is more easily performed as the period during which the stirring operation is not performed is longer. Therefore, it is possible to prevent the ejection operation from being performed in a state where the particles are settled to such an extent that they are not suitable for liquid ejection in the liquid container.

  In the liquid ejecting apparatus, the liquid ejecting apparatus may further include a mounting unit that mounts the liquid storage unit in a detachable and replaceable manner, and the determination unit does not perform the stirring operation after the replacement of the liquid storage unit. It is preferable to determine the degree of sedimentation larger than when the stirring operation is performed.

  A storage state such as a storage environment or a storage posture of the liquid storage unit may affect the sedimentation degree of the liquid storage unit. Here, the storage state of the liquid storage unit is clear when the liquid storage unit is mounted, whereas the storage state of the liquid storage unit is unclear when the liquid storage unit is not mounted. .

  According to the above configuration, when the stirring operation has not been executed even after replacement of the liquid container, the degree of sedimentation is determined to be greater than when the stirring operation has been executed even once. For this reason, when there is a possibility that the sedimentation degree is increased depending on the storage state of the liquid container, such as immediately after the replacement of the liquid container, the stirring operation is easily performed. Therefore, it is possible to prevent the ejection operation from being performed in a state where the particles are settled to such an extent that the liquid accommodation unit is not suitable for ejecting the liquid due to the storage state of the liquid accommodation unit.

In the liquid ejecting apparatus, it is desirable that the control unit increase the stirring strength in the stirring operation when the settling degree is large, compared to when the settling degree is small.
According to the above configuration, since the stirring strength in the stirring operation is determined according to the sedimentation degree, the stirring operation can be executed with an appropriate stirring strength according to the sedimentation degree.

  In the liquid ejecting apparatus, it is preferable that the control unit increases the stirring intensity in the stirring operation when the remaining amount of the liquid stored in the liquid storing unit is large than when the remaining amount is small.

  In order to improve the sedimentation degree of the liquid container, it is necessary to cause the liquid to flow more strongly in the liquid container as the remaining amount of liquid in the liquid container is larger. In this regard, according to the above configuration, when the remaining amount of the liquid storage unit is large, the stirring operation is performed with a stronger stirring strength than when the remaining amount is small, and thus appropriate stirring according to the remaining amount of liquid is performed. The stirring operation can be executed with high strength.

  In the liquid ejecting apparatus, the ejecting operation is a printing operation in which a liquid is ejected onto the medium to perform printing on the medium, and the control unit performs the second operation based on the content of printing on the medium. It is desirable to change at least one of the threshold value and the stirring intensity in the stirring operation.

  For example, when printing characters, the effect of changes in the sedimentation degree of the liquid container on the print quality (such as the appearance of the printed matter) is likely to be small. The effect of changes on print quality tends to be large. As described above, depending on the printing contents, the influence of the change in the sedimentation degree on the print quality may be different.

  In this regard, in the above configuration, at least one of the second threshold value, which is a threshold value indicating whether or not the printing operation can be performed, and the stirring intensity in the stirring operation are changed. For this reason, if the printing content is such that the settling degree does not easily affect the print quality, the second threshold value is increased to facilitate the printing operation, or the stirring strength in the stirring operation is weakened. Execution time is shortened. In this way, it is possible to reduce the downtime of the printing operation according to the printing content.

The schematic diagram which shows schematic structure of a liquid ejecting apparatus. The perspective view which shows schematic structure of a liquid storage bag. FIG. 3 is a block diagram illustrating an electrical configuration of the liquid ejecting apparatus. The flowchart which shows the process routine which a control part implements in order to perform either printing operation and stirring operation. The flowchart which shows the subroutine which a control part implements in order to judge whether a stirring operation is interrupted during printing operation. The flowchart which shows the subroutine which a control part implements in order to judge whether a printing operation interrupts during a stirring operation. It is a timing chart which shows a mode that printing operation is interrupted, (a) shows transition of a sedimentation degree, (b) shows the execution state of printing operation, (c) shows the execution state of stirring operation. Show. It is a timing chart which shows a mode that stirring operation is interrupted, (a) shows transition of a sedimentation degree, (b) shows the execution state of printing operation, (c) shows the execution state of stirring operation. Show.

Hereinafter, an embodiment in which a liquid ejecting apparatus is embodied in an ink jet printer (hereinafter also simply referred to as “printer”) will be described with reference to the drawings.
As shown in FIG. 1, the liquid ejecting apparatus 11 includes a main body case 12 having a substantially rectangular box shape. A support member 13 that supports the medium M is provided along the longitudinal direction (left and right direction in FIG. 1) of the main body case 12 in the main scanning direction X at the lower front portion in the main body case 12.

  A guide shaft 14 extending in the main scanning direction X is provided above the rear portion of the support member 13 in the main body case 12. The guide shaft 14 supports a carriage 15 that reciprocates in the main scanning direction X. A driving pulley 16 is rotatably supported at a position corresponding to one end (right end in the figure) of both ends of the guide shaft 14 on the rear side surface in the main body case 12, and corresponds to the other end (left end in the figure). A driven pulley 17 is rotatably supported at the position.

  A carriage motor 18 is connected to the drive pulley 16. An endless timing belt 19 is hung between the driving pulley 16 and the driven pulley 17. Then, the driving force of the carriage motor 18 is transmitted to the carriage 15 through the timing belt 19 so that the carriage 15 reciprocates in the main scanning direction X.

  A liquid ejecting unit 21 having a plurality of nozzles (not shown) for ejecting ink as an example of liquid is attached to the lower surface side of the carriage 15. In addition, a home position HP serving as a retracted position of the liquid ejecting unit 21 is provided in the movement range of the carriage 15 in the main scanning direction X. A maintenance device 22 that performs various maintenance processes is provided below the home position HP.

  As shown in FIG. 1, the carriage 15 is provided with a valve unit 23 that adjusts the pressure of ink supplied to the liquid ejecting unit 21. The ink stored in the liquid storage unit 30 is supplied to the valve unit 23 through the supply channel 24.

  In addition, the liquid ejecting apparatus 11 includes a mounting unit 25 on which the liquid storage unit 30 is mounted in a certain posture. The mounting unit 25 is electrically connected to a substrate provided in the mounted liquid storage unit 30 and reads information such as the type of ink and the remaining amount of ink in the liquid storage unit 30.

  Here, in FIG. 1, the first liquid storage portion 301 that stores the first ink, the first mounting portion 251 to which the first liquid storage portion 301 is mounted, and the first valve unit 231 are first connected. Only the first supply channel 241 for supplying the ink is shown. The other ink storage section, mounting section, and supply flow path have the same configurations as those of the first ink configuration, and thus illustration and description thereof will be omitted.

  Then, the liquid ejecting apparatus 11 prints characters and images on the medium M by ejecting ink toward the medium M from the liquid ejecting unit 21 supported by the carriage 15 that reciprocates in the main scanning direction X. Print operation ". In the present embodiment, this printing operation corresponds to an example of an “ejection operation” for ejecting ink. The printing operation is executed when a print job is generated, for example, according to a print instruction from a computer (not shown) connected to the liquid ejecting apparatus 11 via a wired or wireless connection.

Next, the liquid storage unit 30 will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the liquid storage unit 30 includes a box-shaped case member 31, a liquid storage bag 40 stored in the case member 31, a first compression mechanism 32 and a first compression mechanism 32 that compress the liquid storage bag 40. 2 compression mechanisms 33.

  As shown in FIG. 2, the liquid storage bag 40 is formed in a bag shape by thermally welding the edges of its four sides in a state where two substantially rectangular films are overlapped. Thus, the liquid storage bag 40 is formed with a storage portion 41 capable of storing the liquid.

  Further, the liquid storage bag 40 is provided with a partition portion 42 by heat-welding the substantially longitudinal center of the liquid storage bag 40 in the lateral direction. The partition part 42 partitions the storage part 41 of the liquid storage bag 40 into a first storage part 411 and a second storage part 412. Here, a part of the first storage part 411 and the second storage part 412 communicate with each other through the communication part 43. That is, in the short direction of the liquid storage bag 40, the length dimension of the partition portion 42 is shorter than the length dimension of the liquid storage bag 40.

  A supply port 44 that communicates with the first reservoir 411 is provided on one side of the liquid storage bag 40. The supply port 44 is connected to the supply channel 24 when the liquid storage unit 30 is mounted on the mounting unit 25. In addition, a smaller amount of ink is injected into the liquid storage bag 40 than the total capacity of the first storage unit 411 and the second storage unit 412. For this reason, the outer shape of the liquid storage bag 40 can be deformed according to an external force even in a state where the ink is stored.

  In the present embodiment, the ink stored in the liquid storage unit 30 is a liquid in which particles (solid substance) such as pigment particles and resin are dispersed in an ink solvent. For this reason, the particles in the ink may settle vertically below the liquid storage bag 40 of the liquid storage unit 30. In the following description, the degree of sedimentation of the particles in the ink is also referred to as “sedimentation degree”. That is, the larger the sedimentation degree, the more particles are settled in the liquid storage bag 40 (liquid storage unit 30).

  In addition, the sedimentation degree does not simply mean the mass of particles that have settled in the liquid storage bag 40, but how many of the particles contained in the ink stored in the liquid storage bag 40 have settled. Let's say the ratio. That is, even when the ink remaining amount in the liquid containing bag 40 is small, the settling degree may be larger than when the ink remaining amount is large.

  As shown in FIG. 1, the first compression mechanism 32 includes a compression plate 34 that can compress the first reservoir 411 on both sides in the thickness direction of the first reservoir 411 of the liquid containing bag 40. Yes. Further, the second compression mechanism 33 has compression plates 35 that can compress the second storage portion 412 on both sides of the liquid storage bag 40 in the thickness direction of the second storage portion 412.

  Thus, the first compression mechanism 32 compresses the first storage unit 411, the second compression mechanism 33 compresses the second storage unit 412, or the first compression mechanism 32 and the second compression mechanism. 33 compresses the first storage unit 411 and the second storage unit 412, so that the ink stored in the liquid storage bag 40 is pressurized and supplied toward the valve unit 23.

  Moreover, the 1st compression mechanism 32 and the 2nd compression mechanism 33 repeat the compression of the 1st storage part 411 and the compression of the 2nd storage part 412 by turns, and the 1st storage part 411 and the 2nd compression mechanism 33 are repeated. The “stirring operation” is performed to improve the sedimentation degree in the liquid storage bag 40 by causing the ink to flow between the two storage portions 412. In this respect, in the present embodiment, the first compression mechanism 32 and the second compression mechanism correspond to an example of a “stirring unit” that stirs the ink stored in the liquid storage unit 30.

  Specifically, the first compression mechanism 32 compresses the first storage unit 411, thereby causing the ink stored in the first storage unit 411 to flow to the second storage unit 412 via the communication unit 43. . Subsequently, the second compression mechanism 33 compresses the second storage unit 412, thereby causing the ink stored in the second storage unit 412 to flow into the first storage unit 411 via the communication unit 43. . By repeating this, sedimentation of particles in the liquid containing bag 40 is eliminated. In the following description, after one compression mechanism is driven, the other compression mechanism is driven, so that the “one-time” stirring operation is performed.

Next, the electrical configuration of the liquid ejecting apparatus 11 will be described with reference to FIG.
As shown in FIG. 3, the liquid ejecting apparatus 11 includes a control unit 50 that controls the apparatus in an integrated manner. The mounting unit 25 is connected to the input side interface of the control unit 50, and the liquid ejecting unit 21, the carriage motor 18, the first compression mechanism 32, and the second compression mechanism 33 are connected to the output side interface of the control unit 50. ing.

  Then, the control unit 50 controls the driving of the liquid ejecting unit 21 and the carriage motor 18 to execute the printing operation. Further, the control unit 50 controls the driving of the first compression mechanism 32 and the second compression mechanism 33 based on the information on the liquid storage unit 30 mounted on the mounting unit 25 and other information, so that the liquid The stirring operation of the storage unit 30 is performed.

  In the present embodiment, the control unit 50 determines (calculates) the sedimentation degree of the liquid storage unit 30 based on various types of information regarding the liquid storage unit 30. That is, in the present embodiment, the control unit 50 is an example of a “determination unit” that determines the sedimentation degree of the liquid storage unit 30. Further, in the following description, whether or not the degree of sedimentation is determined by the control unit 50 is distinguished depending on whether or not the sign “Sd” is added to the “sedimentation degree”. That is, the sedimentation degree determined by the control unit 50 is set as “sedimentation degree Sd”.

Hereinafter, a method for determining the sedimentation degree Sd in the present embodiment will be described.
First, in the liquid storage unit 30, when the stirring operation is not performed, the number of particles that settles vertically below the liquid storage unit 30 increases with the passage of time. Therefore, in this embodiment, when the period when the stirring operation is not executed is long, the control unit 50 determines the settling degree Sd to be larger than when the synchronization period is short.

  In addition, the period when the stirring operation said here is not performed is the elapsed time after performing stirring operation last time. Further, the period during which the stirring operation is not performed may include an elapsed time after manufacture of the liquid storage unit 30 and an elapsed time after installation of the liquid storage unit 30 with respect to the mounting unit 25.

  In the liquid storage unit 30, the higher the viscosity of the ink solvent stored in the liquid storage bag 40, the more difficult the particles in the ink settle. Also, the smaller the particle size (size) of the particles in the ink, the more difficult it is to settle. Thus, depending on the type of ink, even if the elapsed times are equal, the sedimentation degree may change in a different manner.

  For this reason, in this embodiment, the control unit 50 determines the sedimentation degree Sd based on the type of ink stored in the liquid storage bag 40. For example, the control unit 50 determines that the sedimentation degree Sd is larger when the viscosity of the ink solvent is low than when the viscosity is high. Further, the control unit 50 determines that the sedimentation degree Sd is larger when the particle size of the particles contained in the ink is larger than when the particle size is small.

  Moreover, the liquid storage part 30 may differ in the sedimentation location of particle | grains, or the quantity of the particle | grains settled in the sedimentation location depending on the attitude | position at the time of the storage, and an environment. That is, the liquid storage unit 30 immediately after being mounted on the mounting unit 25 may have a difference in sedimentation depending on the storage state before the mounting.

  For this reason, in the present embodiment, after the replacement of the liquid storage unit 30, the control unit 50 performs the stirring operation of the liquid storage unit 30 when the replacement operation of the liquid storage unit 30 is not performed. The sedimentation degree Sd is determined to be larger than when it is executed. That is, when the liquid storage unit 30 is replaced, the settling degree Sd of the liquid storage unit 30 is determined to be larger than when the liquid storage unit 30 is not replaced.

  Thus, in the present embodiment, the elapsed time since the most recent stirring operation is performed, the type of ink stored in the liquid storage unit 30, and whether the stirring operation is performed after the liquid storage unit 30 is replaced. Thus, the sedimentation degree Sd is determined. Specifically, a map or the like indicating a change in the sedimentation degree Sd according to the elapsed time after the stirring operation is performed may be obtained in advance by experiment, and the sedimentation degree Sd may be determined by referring to the map or the like. .

  As for the type of ink, the ease of change of the sedimentation degree Sd is obtained as a coefficient for each ink, and the coefficient is used for the sedimentation degree Sd calculated according to the elapsed time since the stirring operation was performed. You may consider it by multiplying. As an example of the above coefficient, “1.2” may be used for ink in which particles in ink tend to settle, while “0.8” may be set for ink in which particles in ink are difficult to settle.

  Further, regarding whether or not the stirring operation is performed after the replacement of the liquid storage unit 30, a coefficient is prepared so that the value when the stirring operation is not performed is larger than that when the stirring operation is performed. You may consider by multiplying the sedimentation degree Sd calculated according to the elapsed time after performing operation | movement with the coefficient. As an example of the above coefficient, “1.2” is set when the stirring operation is not executed after the replacement of the liquid storage unit 30, while “1” is set when the stirring operation is executed after the replacement of the liquid storage unit 30. .0 ".

  When the sedimentation degree is large, that is, when the ratio of the sedimented particles among the particles contained in the ink is large in the liquid containing bag 40, good print quality cannot be obtained by executing the printing operation. There is a fear. This is because when the sedimentation degree is large, the content of the pigment particles and the resin in the ink ejected from the liquid ejecting unit 21 is decreased, so that the color of the ink landed on the medium M is deteriorated (thin). Because. In the following description, the deterioration of the color of the ink is also referred to as “decrease in print quality”.

  Therefore, in the present embodiment, one of the printing operation and the stirring operation is executed according to the sedimentation degree Sd. That is, when the sedimentation degree Sd is greater than or equal to a first threshold value (hereinafter also referred to as “first threshold value Th1”), the agitation operation is performed, while the second sedimentation degree Sd is greater than the first threshold value Th1. When it is less than the threshold (hereinafter also referred to as “second threshold Th2”), the printing operation is executed. Furthermore, when the sedimentation degree Sd is equal to or higher than the first threshold Th1 and lower than the second threshold Th2, the printing operation is executed with priority over the stirring operation.

  Here, the first threshold Th1 is a sedimentation degree when the particles are settled to such an extent that the print quality is not affected even if the printing operation is performed, and the second threshold Th2 is the printing operation. Is the degree of sedimentation when the particles are settled to such an extent that printing quality is affected. In other words, the first threshold value Th1 is a threshold value indicating a slight sedimentation state, and the second threshold value Th2 is a threshold value indicating a severe sedimentation state. Note that the first threshold value Th1 and the second threshold value Th2 execute a printing operation under various conditions in advance, and relate the sedimentation degree Sd under various conditions to the evaluation result of the print quality of the printed material under various conditions. It can be decided by.

  Further, when the sedimentation degree Sd is less than the first threshold Th1, it is not necessary to perform the stirring operation, and when the sedimentation degree Sd is equal to or greater than the first threshold Th1 and less than the second threshold Th2. It is desirable to perform the stirring operation, and it can be said that the stirring operation needs to be performed when the sedimentation degree Sd is equal to or greater than the second threshold Th2. Further, it can be said that the printing operation can be performed when the sedimentation degree Sd is less than the second threshold Th2, and the printing operation cannot be performed when the sedimentation degree Sd is greater than or equal to the second threshold Th2.

  Thus, in the present embodiment, even when the sedimentation degree Sd is equal to or higher than the first threshold Th1 and lower than the second threshold Th2, in other words, even when it is desirable to execute the stirring operation, a print job is generated. If it is, the printing operation can be executed.

  In addition, when the sedimentation degree Sd is large, the sedimentation degree Sd of the liquid storage unit 30 is set to the first degree because the ratio of the sedimented particles among the particles contained in the ink is larger than when the sedimentation degree Sd is small. In order to improve to less than the threshold Th1, it is desirable to increase the number of times of stirring in the stirring operation of the first compression mechanism 32 and the second compression mechanism 33. Therefore, in the present embodiment, the control unit 50 increases the number of times of stirring (stirring strength) in the stirring operation when the sedimentation degree Sd is large, compared to when the sedimentation degree Sd is small.

  Here, the agitation strength means how much ink flows inside the liquid storage unit 30. That is, “high stirring strength” means that the ink flows strongly (many) inside the liquid container 30. For this reason, in this embodiment, the stirring intensity is proportional to the number of stirrings in the stirring operation of the first compression mechanism 32 and the second compression mechanism 33.

  Next, a processing routine executed by the control unit 50 of the liquid ejecting apparatus 11 will be described with reference to flowcharts shown in FIGS. This processing routine is a processing routine that is repeatedly executed for each preset control cycle.

  As shown in FIG. 4, the control unit 50 acquires the sedimentation degree Sd (step S11). Here, as described above, the sedimentation degree Sd is determined based on various types of information regarding the liquid storage unit 30 such as an elapsed time since the previous stirring operation was performed. Subsequently, the control unit 50 acquires the first threshold Th1 (Step S12), and acquires the second threshold Th2 (Step S13).

  Then, the control unit 50 determines whether or not the printing operation is being executed (step S14). If the printing operation is being executed (step S14: YES), the first processing routine is executed (step S14). S15). Here, the first processing routine is a subroutine for confirming whether or not the agitation operation is interrupted during the printing operation. After executing the first processing routine, the control unit 50 ends the processing once.

  On the other hand, when the printing operation is not being executed in step S14 (step S14: NO), the control unit 50 determines whether or not the stirring operation is being executed (step S16). If the stirring operation is being executed (step S16: YES), the second processing routine is executed (step S17). Here, the second processing routine is a subroutine for confirming whether or not to interrupt the printing operation during execution of the stirring operation. After executing the second processing routine, the control unit 50 once ends the processing.

  On the other hand, when the stirring operation is not being executed in step S16 (step S16: NO), the control unit 50 determines whether there is a print job (step S18). If there is a print job (step S18: YES), the control unit 50 determines whether or not the sedimentation degree Sd acquired in step S11 is less than the second threshold Th2 acquired in step S13 (step S19).

  When the sedimentation degree Sd is less than the second threshold Th2 (step S19: YES), that is, when the sedimentation degree Sd of the liquid storage unit 30 is the sedimentation degree Sd that allows the execution of the printing operation, the control unit 50 Execution of the printing operation related to the print job is started (step S20). Then, the control part 50 once complete | finishes the process.

  On the other hand, if there is no print job in step S18 (step S18: NO), the control unit 50 determines whether or not the sedimentation degree Sd is equal to or greater than the first threshold Th1 acquired in step S12 (step S21). . In step S19, when the sedimentation degree Sd is equal to or greater than the second threshold Th2 (step S19: NO), that is, there is a print job, but the sedimentation degree Sd of the liquid storage unit 30 cannot allow the printing operation to be performed. When it is degree Sd, the control unit 50 determines whether or not the sedimentation degree Sd is equal to or greater than the acquired first threshold value Th1 (step S21).

  When the sedimentation degree Sd is less than the first threshold Th1 (step S21: NO), that is, when it is not necessary to execute the stirring operation, the control unit 50 once ends the process. On the other hand, when the sedimentation degree Sd is greater than or equal to the first threshold Th1 (step S21: YES), that is, when it is necessary to execute the agitation operation, the control unit 50 determines the agitation intensity according to the sedimentation degree Sd. (Step S22), execution of the stirring operation is started with the stirring intensity (Step S23). Then, the control part 50 once complete | finishes the process.

  In this way, in the flowchart shown in FIG. 4, the determination whether or not the printing operation can be performed (step S19) is performed before the determination whether or not the stirring operation needs to be performed (step S21). Thus, the execution of the printing operation has priority over the execution of the stirring operation.

  In addition, since the processing routine is repeatedly executed until at least step S21 is negative, in the processing routine, the first processing is repeatedly executed if the printing operation is being performed, and the second processing if the stirring operation is being performed. This process is repeatedly executed.

Next, with reference to FIG. 5, a first processing routine for confirming whether or not the stirring operation is interrupted during the printing operation will be described.
As shown in FIG. 5, the control unit 50 determines whether or not the sedimentation degree Sd acquired in step S11 is greater than or equal to the second threshold Th2 acquired in step S13 (step S31). If it is less than the threshold value Th2 of 2 (step S31: NO), the process is temporarily terminated. That is, in this case (step S31: NO), the sedimentation degree Sd of the liquid storage unit 30 is the sedimentation degree Sd that allows the execution of the printing operation, and there is no need to interrupt the stirring operation. This is the case.

  On the other hand, when the sedimentation degree Sd is greater than or equal to the second threshold Th2 (step S31: YES), that is, when the sedimentation degree Sd of the liquid storage unit 30 is the sedimentation degree Sd that cannot allow the printing operation to be performed, the control unit 50 Interrupts the printing operation (step S32) and determines the stirring intensity according to the sedimentation degree Sd (step S33). Subsequently, the control unit 50 starts the execution of the stirring operation with the determined stirring intensity (step S34). And the control part 50 acquires the sedimentation degree Sd again (step S35), and determines whether the sedimentation degree Sd is less than 2nd threshold value Th2 (step S36).

  When the sedimentation degree Sd is greater than or equal to the second threshold Th2 (step S36: NO), that is, when the sedimentation degree Sd of the liquid storage unit 30 is the sedimentation degree Sd that cannot allow the printing operation to be performed, the control unit 50 The process proceeds to the previous step S35. In this way, the processes of step S35 and step S36 are recursively executed until the settling degree Sd becomes the settling degree Sd that allows the execution of the printing operation.

  When the sedimentation degree Sd is less than the second threshold Th2 (step S36: YES), that is, when the sedimentation degree Sd of the liquid storage unit 30 becomes the sedimentation degree Sd that allows the execution of the printing operation, the control unit 50 The stirring operation that has been interrupted is stopped (finished) (step S37), and the printing operation is resumed (step S38). Thereafter, the control unit 50 ends the process.

  Incidentally, in step S36, the case where the sedimentation degree Sd is less than the second threshold Th2 is the case where the sedimentation degree Sd of the liquid storage unit 30 becomes the sedimentation degree Sd that allows the execution of the printing operation. It is desirable that the agitation operation is not interrupted again because the sedimentation degree Sd becomes equal to or greater than the second threshold value Th2 immediately after the execution of the printing operation is resumed. For this reason, in step S36, it is desirable to determine whether it is less than the second threshold Th2 and less than the third threshold Th3 that is equal to or greater than the first threshold Th1. The same applies to step S42 described later.

Next, a second processing routine for confirming whether or not to interrupt the printing operation during the stirring operation will be described with reference to FIG.
As shown in FIG. 6, the control unit 50 determines whether there is a print job (step S41). If there is no print job (step S41: NO), the control unit 50 once ends the process in order to continue execution of the stirring operation.

  On the other hand, when there is a print job (step S41: YES), the control unit 50 determines whether or not the sedimentation degree Sd acquired in step S11 is less than the second threshold Th2 acquired in step S13 (step S42). ).

  When the sedimentation degree Sd is greater than or equal to the second threshold Th2 (step S42: NO), that is, when the sedimentation degree Sd of the liquid storage unit 30 is the sedimentation degree Sd that cannot allow the printing operation to be performed, the agitation operation is performed. In order to continue, the control part 50 once complete | finishes the process.

  On the other hand, in step S42, when the sedimentation degree Sd is less than the second threshold Th2 (step S42: YES), that is, when the sedimentation degree Sd of the liquid storage unit 30 is the sedimentation degree Sd that allows the execution of the printing operation. The control unit 50 interrupts the stirring operation (step S43) and starts executing the printing operation (step S44).

  Subsequently, the control unit 50 obtains the sedimentation degree Sd again (step S45), and determines whether the sedimentation degree Sd is equal to or greater than the second threshold Th2 (step S46). When the sedimentation degree Sd is greater than or equal to the second threshold Th2 (step S46: YES), the control unit 50 interrupts the printing operation started in step S44, and proceeds to step S48 described later. In this case (step S46: YES), the execution of the printing operation is continued, and the sedimentation degree Sd becomes greater than or equal to the second threshold Th2, and the execution of the printing operation cannot be continued. This is the case.

  On the other hand, when the sedimentation degree Sd is less than the second threshold Th2 (step S46: NO), the control unit 50 determines whether or not the execution of the printing operation is finished (step S47), and the printing operation is finished. If not (step S47: NO), the process proceeds to step S45. That is, the processes in steps S45 to S47 are repeatedly executed until the printing operation is finished.

  In step S47, when the execution of the printing operation is completed (step S47: YES), the control unit 50 re-determines the stirring intensity (step S48) and restarts the execution of the stirring operation with the re-determined stirring intensity ( Step S49).

  Here, when the execution of the printing operation is interrupted in order to interrupt the printing operation, the stirring of the number of times of stirring (stirring intensity) determined in step S22 is not performed, and the liquid container There is room for improving the settling degree Sd of 30. Therefore, in this embodiment, when the execution of the stirring operation is interrupted in order to execute the printing operation, the execution of the stirring operation is resumed after the execution of the printing operation is completed.

  Further, since the stirring operation is executed until the printing operation is interrupted, the stirring intensity of the stirring operation that is resumed may be lower than the stirring strength of the interrupted stirring operation. . For this reason, in this embodiment, it decided to change according to the execution content of the stirring operation which interrupted the stirring intensity | strength in the restarted stirring operation.

  For example, the number of stirrings (stirring intensity) determined in step S22 is “target number Nt”, the number of stirrings performed until the printing operation is interrupted is “execution number Nr”, and the number of stirrings in the restarted stirring operation Is “remaining number of times Nd”. In this case, the remaining number of times Nd corresponding to the stirring intensity re-determined in step S48 may be a difference obtained by subtracting the number of executions Nr from the target number of times Nt.

  Further, when the printing operation is executed, the ink used for the printing operation flows out of the liquid storage unit 30, so that the ink flows in the liquid storage bag 40. That is, the execution of the printing operation may affect the sedimentation degree of the liquid storage unit 30.

  For example, when the amount of ink flowing in the liquid storage bag 40 accompanying the execution of the printing operation is large, the ink stirring effect is large, and the sedimentation degree Sd may gradually decrease by continuing the printing operation. . On the other hand, when the amount of ink flowing in the liquid storage bag 40 accompanying the execution of the printing operation is small, the stirring effect of the ink is small, and the sedimentation degree Sd may gradually increase by continuing the execution of the printing operation. .

  Therefore, in this embodiment, the stirring intensity in the restarted stirring operation is changed according to the execution content of the printing operation. Specifically, it is determined in advance whether the execution of the printing operation contributes to the improvement of the sedimentation degree of the liquid storage unit 30 by comparing the transition of the printing quality when the printing operation is continuously executed. It may be determined and the stirring intensity may be changed based on the determination.

  Then, when the sedimentation degree Sd is reduced by the execution of the printing operation, the number of times of subtracting the number of times according to the period during which the execution of the printing operation is continued from the remaining number of times Nd is the number of times of stirring in the stirring operation at the time of restart. And it is sufficient. On the other hand, when the sedimentation degree Sd is increased by the execution of the printing operation, the number of times of the stirring operation at the restart is obtained by adding the number of times corresponding to the period during which the printing operation is continued to the remaining number of times Nd. And it is sufficient.

Then, after resuming the execution of the stirring operation, the control unit 50 once ends the process.
Next, the operation of the liquid ejecting apparatus 11 according to this embodiment will be described with reference to FIGS.

  First, with reference to FIG. 7, when a print job is generated during the execution of the stirring operation, which of the printing operation and the stirring operation is to be executed will be described. In the timing chart shown in FIG. 7, the timing at which the print job is generated is the first timing t11. In the timing chart shown in FIG. 7, in order to facilitate understanding of the explanation, it is assumed that the sedimentation degree does not increase by continuing the execution of the printing operation.

  FIG. 7 shows a printer that performs the printing operation only when the sedimentation degree Sd is less than the first threshold Th1, while executing the stirring operation only when the sedimentation degree Sd is equal to or greater than the first threshold Th1. Are also shown as comparative examples.

  As shown by broken lines in FIGS. 7A, 7B, and 7C, in the case of the comparative example, the settling degree Sd is equal to or higher than the first threshold Th1 at the first timing t11. Execution is restricted, and execution of the stirring operation is started. Then, at the third timing t13 when the sedimentation degree Sd becomes less than the first threshold value Th1, the stirring operation is finished and the printing operation is started. Subsequently, at the fourth timing t14 subsequent to the third timing t13, the execution of the printing operation ends.

  In contrast, as indicated by solid lines in FIGS. 7A, 7B, and 7C, in the case of the present embodiment, the sedimentation degree Sd becomes equal to or greater than the second threshold Th2 at the first timing t11. Therefore, the execution of the printing operation is restricted (step S19: NO), and the execution of the stirring operation is started (step S23). Here, the stirring intensity of the stirring operation that is started from the first timing t11 is determined according to the sedimentation degree Sd at the first timing t11 (step S22).

  Then, at the second timing t12 when the sedimentation degree Sd becomes less than the second threshold Th2, the execution of the stirring operation is interrupted (step S42: YES, step S43), and the execution of the printing operation is started (step S44). . Thus, since the execution of the printing operation can be started at the timing when the settling degree Sd that allows the execution of the printing operation is reached, it is not necessary to wait for the completion of the stirring operation until the settling degree Sd becomes less than the first threshold Th1. . That is, the period (down time) during which the printing operation cannot be executed despite the occurrence of a print job is shortened.

  Subsequently, when the execution of the printing operation is finished at the third timing t13 (step S47: YES), the stirring operation whose execution is interrupted at the second timing t12 is resumed (step S49). Here, at the third timing t13, the stirring intensity of the stirring operation whose execution is resumed is the content of the stirring operation performed during the period from the first timing t11 to the second timing t12, and from the second timing t12. It is determined based on the execution contents of the printing operation in the period up to the third timing t13 (step S48).

  For example, when the number of stirring operations (stirring intensity) is determined to be “20 times” at the first timing t11 and “8 times” stirring operations are executed by the second timing t12, At the timing t13, the number of times of stirring in the stirring operation after resumption is determined to be “12 times (20 times−8 times)”. In addition, when the flow of ink corresponding to the “twice” stirring operation has occurred in the liquid storage bag 40 due to the execution of the printing operation from the second timing t12 to the third timing t13, The number of times of stirring in the stirring operation is determined to be “10 times (12 times−2 times)”. In this way, it is suppressed that the execution of the stirring operation is restarted with an excessive number of stirrings.

  Then, at the fourth timing t14, the execution of the stirring operation ends. Further, at the fourth timing t14, the sedimentation degree Sd becomes less than the first threshold Th1, and the sedimentation degree Sd of the liquid storage unit 30 is improved.

  Thus, when the present embodiment is compared with the comparative example, the execution of the printing operation can be started from the earlier timing (second timing t12) in the present embodiment. For this reason, printing related to the print job can be terminated early after the print job is generated.

  Next, with reference to FIG. 8, when a print job is generated during the execution of the stirring operation, which of the printing operation and the stirring operation is to be executed will be described. In the timing chart shown in FIG. 8, the timing at which the print job is generated is the first timing t21. Further, in the timing chart shown in FIG. 8, for the sake of easy understanding of the explanation, it is assumed that the sedimentation degree is increased by continuing the execution of the printing operation.

  As shown in FIGS. 8A, 8B, and 8C, in the present embodiment, the sedimentation degree Sd is less than the second threshold Th2 at the first timing t21 (step S19: YES), a printing operation is executed (step S20). Then, at the second timing t22 when the sedimentation degree Sd becomes equal to or higher than the second threshold Th2, the execution of the printing operation is interrupted (step S31: YES, step S32), and the execution of the stirring operation is started with a predetermined stirring intensity. (Steps S33 and S34). Thus, even when the printing operation is being executed, if the settling degree Sd is such that the printing operation cannot be executed, the execution of the printing operation is interrupted in order to suppress a decrease in print quality.

  When the settling degree Sd reaches the third timing t23 when the settling degree Sd becomes less than the second threshold value Th2 (less than the third threshold value Th3) (step S36: YES), the execution of the stirring action ends ( In step S37, execution of the printing operation is resumed (step S38). Here, the execution of the printing operation is resumed at the timing when the sedimentation degree Sd becomes less than the third threshold Th3. For this reason, when the execution of the printing operation is resumed at the timing when the sedimentation degree Sd becomes less than the second threshold Th2, the sedimentation degree Sd becomes equal to or higher than the second threshold Th2 immediately after the execution of the printing operation is resumed. Therefore, it is possible to suppress a situation where the execution of the printing operation is interrupted immediately.

  Subsequently, at the fourth timing t24 when execution of the printing operation ends, the next print job is not generated (step S18: NO), and the sedimentation degree Sd is equal to or greater than the first threshold Th1 (step S21). : YES), the stirring operation is executed with a predetermined stirring intensity (steps S22 and S23). Then, the execution of the stirring operation ends at the fifth timing t25 when the sedimentation degree Sd becomes less than the first threshold Th1 by the execution of the stirring operation.

  Thus, in this embodiment, when the settling degree Sd becomes equal to or greater than the second threshold Th2 during execution of the printing operation, the settling degree Sd is improved by interrupting the stirring operation, and then the printing is performed. Execution of the operation is resumed. In addition, the execution of the printing operation is resumed at a timing before the settling degree Sd becomes less than the first threshold value Th1 and specifically, becomes less than the third threshold value Th3. For this reason, the situation in which the printing operation cannot be executed until the sedimentation degree Sd becomes less than the first threshold Th1 due to the stirring operation that has been executed even though the print job has occurred is resolved. Is done. That is, the downtime of the printing operation is reduced.

  Although the execution time of the printing operation and the execution time of the stirring operation in the timing charts shown in FIGS. 7 and 8 are similar to each other, the stirring time is actually compared with the execution time of the printing operation. The execution time of the operation is very short.

According to the embodiment described above, the following effects can be obtained.
(1) When the sedimentation degree Sd is greater than or equal to the first threshold Th1 and less than the second threshold Th2, the printing operation is performed with priority over the stirring operation. For this reason, when the sedimentation degree Sd is equal to or higher than the first threshold Th1 and lower than the second threshold Th2, the printing operation needs to be executed (when the print job is generated), the stirring is performed. The printing operation can be executed without waiting for the execution of the operation. Therefore, it is possible to reduce the downtime of the ink printing operation accompanying the execution of the ink stirring operation.

  (2) When the sedimentation degree Sd is greater than or equal to the second threshold Th2 and the printing operation cannot be performed immediately, the agitation operation is first performed. Then, at the timing when the settling degree Sd becomes less than the second threshold Th2 with the execution of the stirring operation, the execution of the stirring operation is interrupted and the printing operation is executed. For this reason, since the printing operation can be executed without waiting until the sedimentation degree Sd becomes less than the first threshold Th1, the printing operation can be performed even when the sedimentation degree Sd is equal to or greater than the second threshold Th2. Downtime can be reduced.

  (3) Based on the influence of the printing operation on the sedimentation degree of the liquid storage unit 30, the stirring intensity when restarting the suspended stirring operation is changed. For this reason, even if the printing operation is interrupted during the stirring operation, the resumed stirring operation is performed with a stirring intensity more than necessary, or even if the restarted stirring operation is performed, the liquid storage unit 30 It can suppress that a sedimentation degree cannot be improved.

  (4) According to the execution content of the suspended stirring operation, the stirring intensity when restarting the suspended stirring operation is changed. For this reason, even if the printing operation is interrupted during the stirring operation, the resumed stirring operation is performed with a stirring intensity more than necessary, or even if the restarted stirring operation is performed, the liquid storage unit 30 It can suppress that a sedimentation degree cannot be improved.

  (5) Even if the printing operation is being performed, the execution of the printing operation is suppressed from being continued in the state where the sedimentation degree Sd is equal to or higher than the second threshold Th2 by interrupting the stirring operation. be able to. For this reason, it is possible to suppress the printing operation from being performed in a state where the particles are settled to an extent that is not suitable for the liquid ejection in the liquid storage unit 30.

  (6) Since the difference in the ink type such as the viscosity of the solvent of the ink and the size of the particles in the ink may affect the change of the sedimentation degree, the sedimentation degree Sd is based on the ink type. Was decided. According to this, even when the liquid ejecting apparatus 11 includes a plurality of liquid storage units 30 that store different types of ink, the stirring operation is performed on each liquid storage unit 30 at an appropriate timing. be able to.

  (7) The longer the period during which the stirring operation is not performed, the larger the settling degree Sd is determined. For this reason, when the period during which the stirring operation is not performed is long, the settling degree Sd is likely to be larger than the first threshold Th1 and the second threshold Th2, and the stirring operation is performed, compared with the case where the synchronization period is short. It becomes easy to be done. Therefore, it is possible to prevent the printing operation from being performed in a state where the particles are settled to an extent that is not suitable for liquid ejection in the liquid storage unit 30.

  (8) When the stirring operation has never been performed after the replacement of the liquid storage unit 30, the sedimentation degree Sd is determined to be larger than when the stirring operation has been performed even once. For this reason, when there is a possibility that the sedimentation degree Sd may be increased depending on the storage state of the liquid storage unit 30, just after the replacement of the liquid storage unit 30, the stirring operation is easily performed. Therefore, it is possible to prevent the printing operation from being performed in a state where the particles are settled to such an extent that the liquid storage unit 30 is not suitable for ejecting the liquid due to the storage state of the liquid storage unit 30.

(9) Since the stirring strength in the stirring operation is determined according to the sedimentation degree Sd, the stirring operation can be executed with an appropriate stirring strength according to the sedimentation degree Sd.
In addition, you may change the said embodiment as shown below.

  If the remaining amount of liquid in the liquid storage unit 30 is large, for example, even if the “10 times” stirring operation is executed, the sedimentation degree of the liquid storage unit 30 may not be improved. On the other hand, when the remaining amount of liquid in the liquid storage unit 30 is small, for example, the settling degree of the liquid storage unit 30 may be improved only by performing the “five times” stirring operation. That is, in order to improve the sedimentation degree of the liquid storage unit 30, it is necessary to cause the ink to flow more strongly in the liquid storage unit 30 as the remaining amount of liquid in the liquid storage unit 30 increases.

  Therefore, when the remaining amount of ink stored in the liquid storage unit 30 is large, the stirring strength in the stirring operation may be increased as compared with the case where the same remaining amount is small. According to this, since the stirring operation is performed with the stirring intensity corresponding to the remaining amount of the liquid storage unit 30, the sedimentation degree can be improved without being affected by the remaining amount of ink.

  When printing characters or graphs, the influence of the change in the sedimentation degree of the liquid storage unit 30 on the print quality (appearance of the printed matter) tends to be small, and when printing an image, the liquid storage unit 30 The influence of the change in the sedimentation degree on the print quality tends to increase. As described above, depending on the print contents, the influence on the print quality with respect to the change in the sedimentation degree may be small. Therefore, the control unit 50 may change the second threshold Th2 based on the print content on the medium M.

  According to this, if the printing content is such that the sedimentation degree does not easily affect the print quality, the second threshold value Th2 is increased, so that the stirring operation is difficult to be performed, and the downtime of the printing operation is reduced by executing the stirring operation. Can be achieved. In addition, if the printing content is such that the sedimentation degree is likely to affect the print quality, the second threshold value Th2 is lowered, so that the stirring operation is easily performed, and the deterioration of the print quality due to the execution of the printing operation can be suppressed.

  When performing printing using ink with high lightness (for example, yellow ink), the effect of the change in the sedimentation degree of the liquid storage unit 30 on the print quality tends to be small, and ink with low lightness (for example, black ink) ), The influence of the change in the sedimentation degree of the liquid storage unit 30 on the print quality tends to increase. This is because ink with high lightness is already high in lightness when the sedimentation level is low, and even if the lightness is further increased by increasing the sedimentation degree, it is difficult to recognize the difference. Therefore, the second threshold value Th2 may be set larger for the ink with high lightness than the ink with low lightness from the beginning. When printing using the ink with high lightness, the ink with low lightness is used. The second threshold Th2 may be made larger than when printing using is performed. According to this, it is possible to reduce downtime and suppress deterioration in print quality according to the lightness of the ink.

  In addition, when there is ink that is not used for printing as in monochrome printing, the first threshold value Th1 and the second threshold value Th2 may not be compared with the sedimentation degree Sd for the ink. According to this, it is possible to reduce downtime.

  In the case where the printing operation is executed, the ink corresponding to the amount of ink used for the printing operation is supplied from the liquid storage unit 30 to the liquid ejecting unit 21, and the ink is stored in the liquid storage bag 40. Flows. Therefore, when the printing operation is performed after the most recent stirring operation is performed, the second threshold Th2 may be set larger than when no operation is performed. According to this, it is possible to reduce downtime and suppress deterioration in print quality depending on whether or not the printing operation is performed.

  In addition, the second threshold Th2 may be increased as the amount of ink used for the printing operation increases. For example, in the case where a plurality of nozzles that eject ink are formed, the second threshold Th2 may be set larger when the number of nozzles that eject ink is large than when the number of nozzles is small. Specifically, the number of times the same type of ink is ejected for each printing pass is added, and the second threshold Th2 may be changed according to the added number.

  When performing cleaning for discharging ink from the nozzles of the liquid ejecting unit 21 regardless of printing, an amount of ink corresponding to the amount of ink discharged by cleaning is supplied from the liquid storage unit 30 to the liquid ejecting unit 21. As a result, the ink flows in the liquid containing bag 40. Therefore, the second threshold Th2 may be set larger when cleaning is performed after the most recent stirring operation is performed than when cleaning is not performed. According to this, it is possible to reduce downtime and suppress deterioration in print quality depending on whether or not cleaning is performed.

  In addition, when changing the magnitude | size of 2nd threshold value Th2 mentioned above, you may change the stirring intensity | strength in stirring operation instead of changing 2nd threshold value Th2. As an example, when cleaning is performed after the most recent stirring operation, the stirring intensity in the next stirring operation may be weaker than when cleaning is not performed. In other words, the number of times of stirring in the next stirring operation may be reduced.

-You may change stirring intensity by controlling the time which performs stirring operation. In this case, the longer the execution time of the stirring operation, the stronger the stirring strength.
The stirring operation may be a stirring operation other than a mode in which the liquid storage bag 40 is crushed. For example, the stirring operation may be performed by incorporating a stirring bar (rotor) inside the liquid storage bag 40 and rotating the stirring bar. In this case, the rotation speed of the stirring bar and the rotation time of the stirring bar affect the stirring strength.

  Further, in the liquid ejecting apparatus 11 in which the liquid storage unit 30 is mounted on the carriage 15, the stirring operation may be performed by reciprocating the carriage 15 in the main scanning direction X. In this case, the moving speed of the carriage 15, the number of movements of the carriage 15, and the moving distance of the carriage 15 affect the stirring intensity.

  -You may determine the sedimentation degree of the liquid storage part 30 by another method. For example, the determination may be made by detecting the lightness (density) of the ink stored in the liquid storage unit 30. In this case, since the control unit 50 does not have to determine the sedimentation degree Sd based on various types of information, the determination accuracy of the sedimentation degree can be improved. In this case, a sensor that detects the lightness (density) of the ink corresponds to an example of a determination unit.

In the case where the printing operation is executed while the stirring operation is being executed, the printing operation may not be interrupted when the sedimentation degree Sd is less than the second threshold Th2.
In the case where the execution of the suspended stirring operation is resumed, the stirring intensity in the resumed stirring operation may not be changed according to the execution content of the interrupted printing operation.

In the case where execution of the suspended stirring operation is resumed, the stirring intensity in the resumed stirring operation may not be changed according to the execution content of the suspended stirring operation.
-Execution of the printing operation may be continued when the sedimentation degree Sd becomes equal to or greater than the second threshold Th2 during the execution of the printing operation.

-It is not necessary to provide a difference in the determination of the sedimentation degree Sd according to the type of liquid stored in the liquid storage unit 30.
-It is not necessary to provide a difference in the determination of the sedimentation degree Sd according to the period when the stirring operation is not executed.

It is not necessary to provide a difference in the determination of the sedimentation degree Sd between when the stirring operation is performed and when the stirring operation is not performed after the liquid storage unit 30 is replaced.
-You may consider particles other than pigment particles and resin as particles in ink.

  When determining the sedimentation degree, for example, considering a substance that can settle or a substance that changes the sedimentation state among pH adjusters, surfactants, preservatives, plasticizers, antioxidants, and ultraviolet absorbers. Also good.

  The liquid ejecting apparatus 11 may be a serial printer in which the liquid ejecting unit 21 ejects ink while reciprocating in the width direction of the medium M, or the liquid ejecting unit 21 has a length corresponding to the entire width of the medium M. And a line printer that ejects ink in a fixed arrangement.

  The liquid ejected by the liquid ejecting unit 21 is not limited to ink, and may be, for example, a liquid material in which functional material particles are dispersed or mixed in the liquid. For example, recording is performed by ejecting a liquid material that is dispersed or dissolved in materials such as electrode materials and color materials (pixel materials) used for manufacturing liquid crystal displays, EL (electroluminescence) displays, and surface-emitting displays. It may be configured.

  The medium M is not limited to paper, and may be a plastic film, a thin plate, or the like, or may be a fabric used in a printing apparatus or the like.

  DESCRIPTION OF SYMBOLS 11 ... Liquid injection apparatus, 21 ... Liquid injection part, 25 ... Mounting part, 30 ... Liquid storage part, 32 ... 1st compression mechanism (an example of a stirring part), 33 ... 2nd compression mechanism (an example of an agitation part) , 40 ... Liquid storage bag, 50 ... Control unit (an example of a determination unit), M ... Medium, Sd ... Sedimentation degree, Th1 ... First threshold, Th2 ... Second threshold, Th3 ... Third threshold.

Claims (11)

A liquid ejecting unit that performs an ejection operation of ejecting the liquid contained in the liquid containing unit toward the medium;
An agitation unit that performs an agitation operation of agitating the liquid stored in the liquid storage unit;
A determination unit that determines a sedimentation degree that increases as particles contained in the liquid contained in the liquid storage unit settle;
A control unit that causes the agitation operation to be executed when the sedimentation degree is equal to or greater than a first threshold value, and that performs the injection operation when the sedimentation degree is less than a second threshold value that is greater than the first threshold value. And comprising
The control unit causes the jetting operation to be executed in preference to the stirring operation when the sedimentation degree is equal to or higher than the first threshold value and lower than the second threshold value. Injection device. In performing the injection operation during the execution of the stirring operation,
When the sedimentation degree is less than the second threshold, the control unit interrupts execution of the agitation operation and performs the injection operation, while the sedimentation degree is equal to or greater than the second threshold. The liquid ejecting apparatus according to claim 1, wherein the stirring operation is continuously performed. In a case where the execution of the agitation operation is interrupted in order to execute the injection operation, the control unit resumes the execution of the agitation operation after the execution of the injection operation is completed, and the restarted agitation The liquid ejecting apparatus according to claim 2, wherein the stirring intensity in the operation is changed according to the execution content of the ejecting operation. In a case where the execution of the agitation operation is interrupted in order to execute the injection operation, the control unit resumes the execution of the agitation operation after the execution of the injection operation is completed, and the restarted agitation The liquid ejecting apparatus according to claim 2, wherein the liquid ejecting apparatus is changed according to the execution content of the stirring operation in which the stirring intensity in the operation is interrupted. When the settling degree is equal to or greater than a second threshold during the execution of the injection operation, the control unit interrupts the execution of the injection operation and executes the stirring operation. The liquid ejecting apparatus according to any one of claims 1 to 4. The liquid ejecting apparatus according to claim 1, wherein the determination unit determines the sedimentation degree based on a type of liquid stored in the liquid storage unit. . The said determination part determines the said sedimentation degree largely when the period when the said stirring operation is not performed is long compared with the case where a synchronous period is short. The any one of Claims 1-6 characterized by the above-mentioned. The liquid ejecting apparatus according to one item. A mounting portion for detachably mounting the liquid storage portion;
The said determination part determines the said sedimentation degree larger than the case where the said stirring operation is performed when the said stirring operation is not performed after replacement | exchange of the said liquid storage part. The liquid ejecting apparatus according to claim 1. The said control part makes the stirring intensity | strength in the said stirring operation strong when the said sedimentation degree is large rather than the case where the said sedimentation degree is small. Any one of Claims 1-8 characterized by the above-mentioned. The liquid ejecting apparatus described. The said control part strengthens the stirring intensity | strength in the said stirring operation when the residual amount of the liquid accommodated in the said liquid storage part is large compared with the case where the same residual amount is small. The liquid ejecting apparatus according to any one of Items 9. The ejection operation is a printing operation for performing printing on the medium by ejecting a liquid onto the medium,
11. The control unit according to claim 1, wherein the control unit changes at least one of the second threshold value and the stirring intensity in the stirring operation based on a printing content on the medium. The liquid ejecting apparatus according to the item.