JP6962115B2 - Liquid discharge device - Google Patents

Description

The present invention relates to a liquid discharge device.

Patent Document 1 discloses an inkjet printer including a head having a nozzle for ejecting ink (liquid) as an example of a liquid ejection device. In this type of inkjet printer, when the ink in the nozzle is thickened, for example, the desired amount of ink is not ejected or the ink does not land at the desired landing position, resulting in a decrease in nozzle ejection performance. do. Therefore, in the inkjet printer of Patent Document 1, a purge process (discharge process) for discharging ink from a nozzle is periodically executed. Further, in the inkjet printer of Patent Document 1, in order to surely restore the ejection property of the nozzle, the higher the viscosity of the ink ejected from the nozzle, the larger the amount of ink ejected during the purge process. ..

Japanese Unexamined Patent Publication No. 2016-190468

By the way, in this type of liquid discharge device, as the discharge process, a pre-print discharge process executed immediately before a print process of discharging a liquid to a recording medium and printing an image, or a periodical execution process is performed periodically. Those capable of executing a plurality of types of discharge treatment such as discharge treatment are known. As a result of diligent studies, the inventor of the present application has found that among such a plurality of types of discharge treatments, there is a discharge treatment that only needs to suppress a decrease in nozzle discharge performance and does not necessarily require recovery of nozzle discharge performance. I found. For example, when the pre-printing discharge process and the periodic discharge process are configured to be executable, the nozzle ejection property must be restored at the start of the printing process. Therefore, in the pre-printing ejection process, the nozzle ejection property is improved. It needs to be recovered. However, with regard to the periodic ejection process, since the ejection property of the nozzle is restored by the pre-printing ejection process at the start of the printing process, it is not necessary to completely restore the nozzle ejection property by the periodic ejection process.

Even in such a discharge process in which it is not necessary to restore the discharge property, if the discharge conditions such as increasing the discharge amount of the liquid are changed when the viscosity of the liquid becomes high, the process related to the change of the discharge conditions. Problems such as increased burden and increased liquid consumption arise.

Therefore, an object of the present invention is to provide a liquid discharge device capable of reducing the processing load related to the discharge treatment and suppressing an increase in the consumption of the liquid.

In order to solve the above problems, the liquid discharge device of the present invention includes a head having a nozzle for discharging the liquid, a liquid discharge unit, and a control unit, and the control unit discharges the liquid from the nozzle. The first discharge process for controlling the liquid discharge unit and the liquid from the nozzle are discharged under the first discharge condition such that the discharge amount is equal to or larger than the minimum discharge amount required for the recovery of the discharge property of the nozzle. The second discharge process for controlling the liquid discharge unit is executed under the second discharge condition such that the discharge amount is smaller than the minimum discharge amount required for the recovery of the discharge property of the nozzle at the time of discharge. Further, the control unit can obtain the viscosity information acquisition process for acquiring the viscosity information regarding the viscosity of the liquid in the head, and the first discharge condition according to the viscosity information acquired by the viscosity information acquisition process. And the condition change process of changing only the first discharge condition among the second discharge conditions while satisfying the discharge amount equal to or more than the minimum discharge amount required for the recovery of the discharge property of the nozzle can be executed. ..

In the present invention, the second discharge condition, which is the discharge condition of the second discharge treatment, is such that when the liquid is discharged from the nozzle, the liquid is discharged with a discharge amount smaller than the minimum discharge amount required to restore the discharge property of the nozzle. Does not change according to the viscosity information. As a result, it is possible to suppress an increase in liquid consumption while reducing the processing load related to the second discharge treatment.
On the other hand, the discharge condition of the first discharge treatment, that is, the first discharge condition that discharges the liquid from the nozzle with a discharge amount equal to or more than the above minimum discharge amount, is changed according to the viscosity information. Therefore, when the first discharge process is executed, the discharge property of the nozzle can be reliably restored.

It is a schematic block diagram of the inkjet printer which concerns on this embodiment. It is a vertical cross-sectional view which shows typically the inkjet head, the ink cartridge, and the cartridge holder. (A) is a plan view of the head body, (b) is an enlarged view of part A of (a), and (c) is a sectional view taken along line BB of (b). It is a block diagram which shows typically the electric structure of an inkjet printer. It is a flowchart explaining the processing operation of the inkjet printer concerning the viscosity estimation process in a cartridge. It is a figure explaining the discharge process. It is a flowchart explaining the processing operation of the inkjet printer concerning the discharge processing.

A schematic configuration of the inkjet printer 1 according to a preferred embodiment of the present invention will be described. As shown in FIG. 1, the printer 1 includes a platen 2, a carriage 3, an inkjet head 5 (hereinafter, also simply referred to as a head 5), a holder 6, a paper feed roller 7, a paper discharge roller 8, a purge device 9, and a flushing receiver 10. , A temperature sensor 160, a touch panel 161 (see FIG. 4), a control device 100, and the like. In the following, the front side of the paper surface of FIG. 1 is defined as "upper side" of the printer 1, and the other side of the paper surface is defined as "lower side" of the printer 1. Further, the front-back direction and the left-right direction shown in FIG. 1 are defined as the "front-back direction" and the "left-right direction" of the printer 1. Hereinafter, the front-back, left-right, and up-down directional words will be described as appropriate.

Paper P, which is a recording medium, is placed on the upper surface of the platen 2. Further, above the platen 2, two guide rails 15 and 16 extending in parallel in the left-right direction (scanning direction) are provided.

The carriage 3 is attached to the two guide rails 15 and 16 and can move in the left-right direction along the two guide rails 15 and 16 in the area facing the platen 2. A drive belt 17 is attached to the carriage 3. The drive belt 17 is an endless belt wound around two pulleys 18 and 19. One pulley 18 is connected to a carriage drive motor 20 (see FIG. 4). The drive belt 17 travels by rotationally driving the pulley 18 by the carriage drive motor 20, whereby the carriage 3 reciprocates in the left-right direction. Further, at this time, the head 5 mounted on the carriage 3 reciprocates in the left-right direction together with the carriage 3.

The holder 6 includes four cartridge mounting portions 41 arranged in the left-right direction. An ink cartridge 42 is detachably mounted on each cartridge mounting portion 41. Black, yellow, cyan, and magenta inks are stored in the four ink cartridges 42 mounted on the four cartridge mounting portions 41, respectively. Further, as shown in FIG. 2, each cartridge mounting portion 41 has an internal flow path 41a formed inside the cartridge mounting portion 41 and a needle 41b made of a cylindrical resin needle connected to one end of the internal flow path 41a. Have. When the ink cartridge 42 is mounted on the cartridge mounting portion 41, the ink in the ink cartridge 42 is supplied to the outside via the needle 41b and the internal flow path 41a. In the present embodiment, the ink stored in each ink cartridge 42 is a pigment ink.

Returning to FIG. 1, the head 5 is mounted on the carriage 3. The head 5 has a head body 13 and a sub tank 14. A tube joint 21 is integrally provided in the sub tank 14. One end of each of the four flexible supply tubes 22 is detachably connected to the tube joint 21. The other ends of each of the four supply tubes 22 are connected to the internal flow paths 41a (see FIG. 2) of the four cartridge mounting portions 41 of the holder 6. The ink in the four ink cartridges 42 mounted on the cartridge mounting portion 41 is supplied to the sub tank 14 via the four supply tubes 22.

The head body 13 is attached to the lower part of the sub tank 14. As shown in FIG. 3A, the head body 13 is formed on a flow path unit 44 in which a plurality of nozzles 46 and a plurality of pressure chambers 83 communicating with the plurality of nozzles 46 are formed, and on the upper surface of the flow path unit 44. It includes an arranged actuator 45.

As shown in FIG. 3C, the flow path unit 44 has a structure in which four plates are laminated. A plurality of nozzles 46 are formed on the lower surface of the flow path unit 44. As shown in FIG. 3A, the plurality of nozzles 46 are arranged in the front-rear direction (the transport direction of the paper P), forming four rows of nozzle rows 47 corresponding to the four colors of ink, respectively. .. Black, yellow, cyan, and magenta inks are ejected from the four nozzle rows 47 in order from the nozzle row 47 located on the right side in the scanning direction. The plurality of pressure chambers 83 are arranged in four rows like the plurality of nozzles 46.

Further, as shown in FIGS. 3A and 3B, the flow path unit 44 is formed with four manifolds 84 extending in the front-rear direction, respectively. The four manifolds 84 supply four colors of ink to each of the four rows of pressure chambers. Further, the four manifolds 84 are connected to four ink supply holes 85 formed on the upper surface of the flow path unit 44. Four colors of ink are supplied from the sub tank 14 to the four ink supply holes 85, respectively. Further, a throttle portion 82 (see FIG. 3C) having a large flow path resistance is provided in the middle of the flow path for supplying ink from the manifold 84 to the pressure chamber 83. From the above configuration, a plurality of individual flow paths are formed in the flow path unit 44, branching from each manifold 84, passing through the throttle portion 82 and the pressure chamber 83, and reaching the nozzle 46.

As shown in FIG. 3C, the actuator 45 includes a diaphragm 87 covering the plurality of pressure chambers 83, a piezoelectric layer 88 arranged on the upper surface of the diaphragm 87, and a plurality of actuators corresponding to the plurality of pressure chambers 83. The individual electrode 89 of the above is provided. The plurality of individual electrodes 89 located on the upper surface of the piezoelectric layer 88 are electrically connected to the driver IC 90 that drives the actuator 45, respectively.

The diaphragm 87 located on the lower surface of the piezoelectric layer 88 is made of a metal material and serves as a common electrode facing a plurality of individual electrodes 89 with the piezoelectric layer 88 interposed therebetween. The diaphragm 87 is connected to the ground wire of the driver IC 90 and is always held at the ground potential.

In the above configuration, when a drive signal having a predetermined drive waveform is input from the driver IC 90 to the individual electrodes 89 in each of the discharge cycles, the volume of the piezoelectric layer 88 corresponding to the drive signals is deformed and the pressure chamber is deformed. Pressure (ejection energy) is applied to the ink in 83, and ink droplets are ejected from the nozzle 46. As described above, a throttle portion 82 is provided between the manifold 84 and the pressure chamber 83. Therefore, the throttle portion 82 suppresses the leakage of the pressure wave generated in the pressure chamber 83 to the manifold 84.

As shown in FIG. 2, the sub tank 14 is a member formed of a synthetic resin, and has a plate-shaped main body portion 60 extending along a horizontal plane and a head extending vertically downward from one end of the main body portion 60. It has a connecting portion 61 connected to the main body 13. The sub tank 14 is formed with a supply flow path 62 for supplying ink to the ink supply holes 85 of the head body 13. In FIG. 2, the sub tank 14 is shown as a vertical cross-sectional view, while the head body 13 is not shown as a cross-sectional view but as a side view.

A tube joint 21 to which the supply tube 22 can be connected is attached to the upper surface of the main body portion 60. By connecting the supply tube 22 to the tube joint 21, the ink stored in the ink cartridge 42 can be supplied to the supply flow path 62.

The supply flow path 62 has a main body flow path 63 formed in the main body portion 60 and a connecting flow path 64 formed in the connecting portion 61 extending in the vertical direction. The main body flow path 63 extends along the horizontal plane. On the other hand, the connecting flow path 64 extends vertically downward from one end (upper end) connected to the main body flow path 63. Further, the connecting flow path 64 is connected to the ink supply hole 85 of the head body 13 at the lower end. The upper end of the connecting flow path 64 is an air storage chamber 65 capable of temporarily storing air. The air storage chamber 65 is the uppermost position in the main body flow path 63 and the connecting flow path 64, like each position of the main body flow path 63. Therefore, the air existing in the supply flow path 62 can be temporarily retained in the air storage chamber 65 without flowing into the head main body 13. In the following, for convenience of explanation, as shown in FIG. 2, the entire flow path from the needle 41b to the plurality of nozzles 46 is collectively referred to as an ink flow path 30.

Further, the main body portion 60 is also formed with an exhaust flow path (not shown) connected to the connecting flow path 64. This exhaust flow path extends to an exhaust portion 23 (see FIG. 1) provided on the right side surface of the sub tank 14. The tip of the exhaust unit 23 is an opening. Further, inside the exhaust unit 23, a valve for switching communication / closing with the outside is installed.

Returning to FIG. 1, the paper feed roller 7 and the paper discharge roller 8 are rotationally driven by the transfer motor 29 (see FIG. 4) in synchronization with each other. The paper feed roller 7 and the paper output roller 8 cooperate with each other to transport the paper P placed on the platen 2 forward (in the transport direction).

Then, the printer 1 has a transport operation of transporting the paper P in the transport direction by the paper feed roller 7 and the paper discharge roller 8, and a recording path for ejecting ink while moving the head 5 in the left-right direction (scanning direction) together with the carriage 3. By repeating the operation alternately, a desired image or the like is printed on the paper P. That is, the printer 1 of this embodiment is a serial type inkjet printer.

The flushing receiver 10 is arranged on the left side of the platen 2. When the carriage 3 is moved to position the head 5 at the flushing position, the plurality of nozzles 46 face the flushing receiver 10 in the vertical direction. Then, in the printer 1, with the head 5 positioned at the flushing position, the actuator 45 of the head 5 is driven to eject the thickened ink or the like from the nozzle 46 toward the flushing receiver 10 to discharge the flushing. Can be done.

The purge device 9 is for suppressing a decrease in the discharge property of the nozzle 46 of the head 5 and performing a maintenance operation for recovering the discharge property, and is a cap unit 50, a suction pump 51, a switching device 52, and a waste liquid. It is equipped with a tank 53 and the like.

The cap unit 50 is arranged on the right side of the platen 2. When the carriage 3 moves to the right of the platen 2, it faces the cap unit 50 vertically. Further, the cap unit 50 is driven by a cap elevating motor 54 (see FIG. 4) and can be elevated and lowered in the vertical direction. The cap unit 50 includes a cap 55 that can be attached in contact with the head 5. The cap 55 is made of, for example, a rubber material, and includes a nozzle cap 55a and an exhaust cap 55b.

When the head 5 faces the cap unit 50, the nozzle cap 55a faces the lower surface of the head body 13, and the exhaust cap 55b faces the lower surface of the exhaust portion 23 of the sub tank 14. In this state, when the cap unit 50 located at a separated position downward from the head 5 is raised to a capping position above the separated position by the cap elevating motor 54, the cap unit 50 is attached to the head 5. Will be done. At this time, the nozzle caps 55a commonly cover all the nozzles 46 belonging to the four rows of nozzle rows 47, and the exhaust caps 55b are connected to the exhaust unit 23. A rod-shaped opening / closing member 27 for opening / closing a valve in the exhaust portion 23 is attached to the exhaust cap 55b. With the exhaust cap 55b connected to the exhaust unit 23, the rod-shaped opening / closing member 27 is driven up and down by the exhaust motor 28 (see FIG. 4) and inserted into the exhaust unit 23 from below. Drive the valve.

The nozzle cap 55a and the exhaust cap 55b are connected to the suction pump 51 via the switching device 52. The suction pump 51 is a rotary pump. The switching device 52 selectively switches the communication destination of the suction pump 51 between the nozzle cap 55a and the exhaust cap 55b. By switching the communication destination of the switching device 52, a suction purge for forcibly discharging ink from all the nozzles 46 belonging to the nozzle rows 47 in the four rows and an exhaust for exhausting the air in the air storage chamber 65 of the sub tank 14 Purge can be performed selectively.

In the suction purge, first, the suction pump 51 is communicated with the nozzle cap 55a by the switching device 52 in a state where the nozzle cap 55a is attached to the head body 13 and covers the plurality of nozzles 46. By driving the suction pump 51 in this state and applying negative pressure (suction) inside the nozzle cap 55a, ink is sucked and discharged from each of the plurality of nozzles 46 of the head body 13. As a result, the highly viscous ink in the ink flow path 30 is discharged from the nozzle 46, and the ejection property of the nozzle 46 can be restored.

In the exhaust purge, the suction pump 51 is communicated with the exhaust cap 55b by the switching device 52 in a state where the exhaust cap 55b is connected to the exhaust unit 23 and the valve in the exhaust unit 23 is opened by the opening / closing member 27. In this state, the suction pump 51 is driven to apply a negative pressure to the exhaust unit 23. As a result, the air in the air storage chamber 65 of the sub tank 14 can be exhausted to the exhaust cap 55b before flowing into the head body 13, and as a result, it is possible to suppress deterioration of the ejection property of the nozzle 46. can. The ink discharged from the head 5 by the suction purge or the exhaust purge is sent to the waste liquid tank 53 connected to the suction pump 51.

The temperature sensor 160 is arranged near the holder 6 and measures the ambient temperature. The touch panel 161 is a user interface capable of accepting various operation inputs from the user and displaying various setting screens, operating states, and the like to the user.

As shown in FIG. 4, the control device 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a non-volatile memory 104, an ASIC (Application Specific Integrated Circuit) 105, and the like. including. The ROM 102 stores a program executed by the CPU 101, various fixed data, and the like. Data (print data, etc.) required for program execution is temporarily stored in the RAM 103. The non-volatile memory 104 stores total supply amount count information 121 and the like, which will be described later. The ASIC 105 is connected to various devices or drive units of the printer 1, such as a head 5 and a carriage drive motor 20. Further, the ASIC 105 is connected to an external device 200 such as a PC via the communication interface 110.

In the following description, various processes performed by the control device 100 will be described as being performed by the CPU 101, but they may be performed in cooperation with the CPU and the ASIC. Further, the control device 100 may include a plurality of CPUs, and the processing may be shared by the plurality of CPUs. Further, the control device 100 may include a plurality of ASICs, and the processing may be shared by the plurality of ASICs. Alternatively, the processing may be performed by one ASIC alone.

The CPU 101 controls the head 5, the carriage drive motor 20, and the like based on the print instruction received from the external device 200, and executes a printing process for printing an image or the like on the paper P. Further, the CPU 101 executes a discharge process of ejecting ink from the nozzle 46 of the head 5 by causing the purge device 9 to perform suction purging or the actuator 45 of the head 5 to perform flushing.

Here, in the present embodiment, the discharge treatment is roughly classified into five types: pre-print flushing treatment, pre-print purge treatment, sedimentation discharge purge treatment, user purge treatment, and periodic purge treatment. Hereinafter, these discharge treatments will be described. In the following, for convenience of explanation, the discharge treatment related to one of the four color inks will be described with a focus.

The pre-print flushing process is a discharge process in which the actuator 45 is made to perform the flushing after receiving a print command from the external device 200 and immediately before executing the print process. By executing the pre-print flushing process immediately before executing the print process, the ejection property of the nozzle 46 can be made good at the start of the print process. As a result, the quality of the image printed on the paper P by the printing process can be improved.

The pre-print purge process is a discharge process in which the purge device 9 is made to perform suction purge after receiving a print command from the external device 200 and before executing the print process. This pre-printing purge process is executed when the thickened ink in the head 5 cannot be discharged only by the pre-printing flushing process due to the high viscosity of the ink in the nozzle 46 and the like. That is, when the viscosity of the ink in the nozzle 46 is equal to or higher than a predetermined threshold value (hereinafter referred to as the first threshold value), the pre-printing purge process is executed. By executing this pre-printing purge process, the ejection property of the nozzle 46 can be more reliably restored, and as a result, the quality of the image printed on the paper P by the printing process can be improved. After executing the pre-printing purge process, it is necessary to lower the cap unit 50 from the capping position to the separated position before starting the printing process. Therefore, even if the pre-printing purge process is executed, the ink in the nozzle 46 is thickened by drying during the period until the start of the printing process. Therefore, in the present embodiment, the CPU 101 is configured to execute the pre-print flushing process immediately before executing the print process even when the pre-print purge process is executed.

Next, before explaining the sedimentation discharge purge process, the premise items will be described. As described above, the ink stored in the ink cartridge 42 is a pigment ink. The pigment ink exists in a state in which the pigment is dispersed in a solvent, and when the pigment is left in a standing state for a long time, a pigment having a large specific density is settled on the bottom of the ink cartridge 42. Therefore, in the ink cartridge 42, if the ink cartridge 42 is left to stand for a long time, a large amount of pigment will settle on the bottom of the ink cartridge 42. As a result, the pigment concentration of the pigment ink is locally increased at the bottom of the ink cartridge 42, and the viscosity thereof is also locally increased. When the pigment ink having a high viscosity due to the precipitation of the pigment is supplied into the nozzle 46, the ejection property of the nozzle 46 cannot be restored even if the pre-printing purge treatment is executed. Therefore, when the CPU 101 receives a print command from the external device 200 and the viscosity of the pigment ink in the nozzle 46 is greater than or equal to the second threshold value due to the sedimentation of the pigment, the CPU 101 sediments and discharges. Perform the purge process instead of the pre-print purge process. In this sedimentation discharge purge treatment, in order to reliably discharge the pigment ink thickened due to the sedimentation of the pigment, the suction pump 51 so as to discharge a large amount of the discharged ink as compared with the pre-printing purge treatment. Driving conditions are set. For example, in the sedimentation / discharge purge process, the rotation time of the suction pump 51 is set to be longer than that in the pre-print purge process. By executing this sedimentation discharge purge process, the discharge property of the nozzle 46 can be recovered more reliably.

The user purge process is a discharge process in which the purge device 9 performs suction purge in response to an operation input by the user via the touch panel 161. For example, the CPU 101 controls the head 5 and the carriage drive motor 20 based on an operation input by the user via the touch panel 161 and a print command received from the external device 200 to check for non-ejection nozzles (for checking for missing nozzles). The test pattern of is printed on paper P. After that, the CPU 101 receives the user's evaluation of the print result of the test pattern via the touch panel 161. Then, when the user's evaluation is an evaluation indicating that the number of non-ejection nozzles is a predetermined number or more, the CPU 101 executes the user purge process with the evaluation as a user purge execution command. In the present embodiment, in this user purge process, the purge device 9 is made to perform a suction purge in which the rotation speed of the suction pump 51 is faster and the rotation time of the suction pump 51 is longer than that in the pre-printing purge process. By executing this user purge process, the ejection property of the nozzle 46 can be reliably restored.

The periodic purge process is a discharge process in which the purge device 9 performs suction purging every time a predetermined period elapses (every one month elapses in this embodiment). Here, when the ink is not ejected from the nozzle 46 for a long period of time, the ink in the nozzle 46 becomes thickened by drying. Even if the ink is not ejected for a long period of time as described above, it is possible to restore the ejection property of the nozzle 46 by executing the pre-print flushing process or the pre-print purge process before the printing process. However, when the ink in the nozzle 46 becomes extremely viscous due to drying, a large amount of ink is discharged from the nozzle 46 in order to restore the ejection property of the nozzle 46 in the pre-print flushing process and the pre-print purge process. There is a need to. Therefore, the CPU 101 executes a periodic purge process every one month to periodically suppress the deterioration of the ejection property of the nozzle 46. As a result, it is possible to prevent the ink in the nozzle 46 from becoming extremely viscous due to drying, and it is possible to suppress the total consumption of ink as compared with a configuration in which the periodic purge treatment is not performed.

Further, in the present embodiment, it is also an object of the periodic purge process to move the air A existing in the supply tube 22 to the air storage chamber 65 of the sub tank 14. Hereinafter, a specific description will be given. When a minute amount of air contained in the ink, air generated by evaporation of water from the ink in the supply tube 22 over time, and an ink cartridge 42 are mounted on the cartridge mounting portion 41 in the supply tube 22. There is biting air or the like that has flowed in from the needle 41b. The air A in these supply tubes 22 gradually moves to the air storage chamber 65 side when ink is ejected or ejected from the nozzle 46 by the printing process or the ejection process. Then, the air A is discharged to the outside together with the ink by the exhaust purge executed when the air A reaches the air storage chamber 65 side.

By the way, unlike the sub tank 14 and the like, the supply tube 22 is a flow path member having high gas permeability (low gas barrier property). Therefore, the air A in the supply tube 22 grows with the passage of time as the atmosphere permeates through the outer wall of the supply tube 22. Therefore, when the air A stays in the supply tube 22 for a long time, the volume of the air A when it reaches the air storage chamber 65 becomes very large. As a result, when the air A is to be discharged by the exhaust purge, it is necessary to increase the discharge amount, which causes problems such as an increase in the discharge amount of the ink discharged at that time.

Therefore, in the present embodiment, the amount of ink discharged by the periodic purge process is set as follows in order to shorten the time that the air A stays in the supply tube 22. That is, the amount of ink discharged by each periodic purge process is set so that the volume when various types of air in the supply tube 22 reach the air storage chamber 65 is less than the capacity of the air storage chamber 65. There is. For example, the volume of the bitten air when flowing into the supply tube 22 is higher than that of other air, and the volume can be estimated in advance by experiments or the like. Therefore, after the biting air has flowed into the supply tube 22, the volume of the biting air when the biting air moves in the supply tube 22 and reaches the air storage chamber 65 only by the periodic purge process is the air storage chamber 65. The amount of ink discharged in each periodic purge process is set so as to be less than the capacity of. By setting the ink discharge amount of each periodic purge process in this way, it is possible to suppress an increase in the ink discharge amount discharged by the exhaust purge.

In each of the ejection processes described above, in order to restore the ejection property of the nozzle 46, it is necessary to change the ejection conditions according to the viscosity of the ink in the nozzle 46. For example, it is necessary to change the discharge conditions so that the higher the viscosity of the ink in the nozzle 46, the larger the amount of ink discharged in the discharge process. Therefore, it is necessary to accurately estimate the viscosity of the ink in the nozzle 46. The discharge condition is a drive condition of the suction pump 51 such as the rotation time, the rotation speed, and the torque of the suction pump 51 in the case of the discharge process in which the purge device 9 performs purging. On the other hand, in the case of the discharge process in which the actuator 45 is flushed, the discharge conditions are the shape of the drive waveform of the drive signal output to the individual electrode 89 and the number of drive signals output to the individual electrode 89. It is a driving condition of the actuator 45 such as (number of flushing occurrences).

Therefore, the CPU 101 executes the following in-nozzle viscosity estimation process for estimating the viscosity of the ink in the nozzle 46. In this in-nozzle viscosity estimation process, an in-cartridge viscosity estimation process for estimating the viscosity of the ink supplied from the ink cartridge 42 is executed every time a predetermined period elapses (in this embodiment, every month), and this cartridge is used. The viscosity of the ink in the nozzle 46 is estimated using the estimation result of the internal viscosity estimation process. Hereinafter, first, the viscosity estimation process in the cartridge will be described in detail.

As described above, in the ink cartridge 42, if the ink cartridge 42 is left to stand for a long time, a large amount of pigment will settle on the bottom of the ink cartridge 42. As a result, the pigment concentration of the pigment ink is locally increased at the bottom of the ink cartridge 42, and the viscosity thereof is also locally increased. Therefore, the viscosity of the ink supplied from the ink cartridge 42 is not always constant but changes. In the in-cartridge viscosity estimation process, the viscosity of the ink supplied from the ink cartridge 42 is estimated.

Here, the amount of pigment settling in the ink cartridge 42 increases as the period in which the ink cartridge 42 is left in a stationary state increases. Further, the amount of pigment settling in the ink cartridge 42 increases as the frequency of ink supply from the ink cartridge 42 decreases. In addition, the higher the temperature in the ink cartridge 42, the lower the viscosity of the pigment ink, so that the precipitation of the pigment is promoted.

Therefore, as shown in FIG. 4, the non-volatile memory 104 has total supply amount count information 121, elapsed time information 122, and temperature history information 123.

The total supply amount count information 121 is count information indicating the total supply amount of ink supplied from the ink cartridge 42 from the time when the ink cartridge 42 is mounted on the cartridge mounting portion 41. The CPU 101 calculates the supply amount each time ink is supplied from the ink cartridge 42 by executing the printing process, the ejection process, and the like, and adds the ink to the count value of the total supply amount count information 121. The amount of ink ejected from the nozzle 46 of the head 5 during the printing process or flushing can be calculated from the driving mode of the actuator 45 or the like. Further, the amount of ink discharged from the nozzle 46 during suction purging can be calculated from driving conditions such as the rotation speed and rotation time of the suction pump 51.

The elapsed time information 122 is information indicating the elapsed time from the time of wearing, and is sequentially updated by the internal clock of the control device 100 after the time of wearing. The temperature history information 123 is the history information of the temperature measured by the temperature sensor 160 from the time of mounting. Every time the CPU 101 measures a certain time by the internal clock, the CPU 101 adds the temperature measured by the temperature sensor 160 to the temperature history information 123.

In the in-cartridge viscosity estimation process, the CPU 101 estimates and acquires sedimentation information regarding the sedimentation amount of the pigment based on the total supply amount count information 121, elapsed time information 122, and temperature history information 123, and uses this sedimentation information as the sedimentation information. Based on this, the viscosity of the ink supplied from the ink cartridge 42 is estimated. The ink viscosity estimated by this in-cartridge viscosity estimation process is stored in the in-cartridge viscosity table 124 of the non-volatile memory 104 as the in-cartridge viscosity information in association with the count value of the total supply amount count information 121. The history of the viscosity information in the cartridge is stored in the viscosity table 124 in the cartridge. Hereinafter, the processing operation of the inkjet printer related to the viscosity estimation process in the cartridge will be described with reference to FIG.

First, the CPU 101 determines whether or not one month has passed from the time of the previous execution of the viscosity estimation process in the cartridge (A1). When it is determined that one month has passed since the previous execution (A1: YES), the ink is supplied from the ink cartridge 42 based on the total supply amount count information 121, the elapsed time information 122, and the temperature history information 123. The in-cartridge viscosity estimation process for estimating the viscosity of the ink is executed (A2). Then, the CPU 101 associates the estimated viscosity of the ink with the current count value of the total supply amount count information 121 and stores it in the cartridge internal viscosity table 124 as the cartridge internal viscosity information (A3). When the processing of A3 is completed, the process returns to the processing of A1.

As described above, the estimated viscosity of the ink supplied from the ink cartridge 42 is stored in the cartridge internal viscosity table 124 in association with the count value of the total supply amount count information 121. In the in-nozzle viscosity estimation process, the ink currently in the nozzle 46 is transferred from the ink cartridge 42 into the ink flow path 30 based on the current count values of the in-cartridge viscosity table 124 and the total supply amount count information 121. The viscosity at the time of inflow (hereinafter referred to as the viscosity at the time of inflow) is estimated. Specifically, first, a subtraction count value obtained by subtracting a count corresponding to the flow path capacity of the ink flow path 30 from the current count value of the total supply amount count information 121 is calculated. Then, in the viscosity table 124 in the cartridge, the viscosity associated with the count value closest to the subtraction count value is estimated as the viscosity at the time of inflow.

After that, the value obtained by adding the amount of increase in viscosity due to drying to the estimated viscosity at the time of inflow is estimated as the viscosity of the ink in the current nozzle 46. The amount of increase in viscosity due to drying is calculated based on the elapsed time from the previous execution time when the ink was ejected or ejected from the nozzle 46 by the printing process or the ejection process. From the above, the viscosity of the ink in the current nozzle 46 can be estimated accurately.

By the way, in each ejection process, if the ejection conditions are changed so as to increase the ink ejection amount when the viscosity of the ink in the nozzle 46 increases, there arises a problem that the ink consumption amount increases. In addition, if the discharge conditions of each discharge process are changed each time the viscosity of the ink in the nozzle 46 estimated by the nozzle viscosity estimation process changes, the processing load on the CPU 101 increases.

Therefore, as a result of diligent studies, the inventor of the present application has found that among the above five types of discharge treatments, there is a discharge treatment that only needs to suppress a decrease in the discharge property of the nozzle 46 and does not necessarily need to recover the discharge property of the nozzle 46. I found. Hereinafter, a specific description will be given.

Of the above five types of discharge processing, each of the three types of discharge processing, pre-print flushing treatment, pre-print purge treatment, and sedimentation discharge purge treatment, executes the print processing after receiving a print command from the external device 200. It is a discharge process that is performed before the operation. Here, if the ejection property of the nozzle 46 is not in a good state during the printing process, the quality of the image recorded on the paper P deteriorates. Therefore, in these three types of discharge treatment, it is necessary to restore the discharge property of the nozzle 46 as shown in FIG.

Further, as described above, the user purge process is a discharge process executed in response to an operation input (execution command of the discharge process) from the user. Even after this user purge process, if the ejection property of the nozzle 46 is not restored and the quality of the image recorded on the paper P remains deteriorated, the user feels distrust of the printer 1. There is a risk. Therefore, as shown in FIG. 6, it is necessary to restore the ejection property of the nozzle 46 also in the user purge process.

Based on the above, regarding the discharge conditions for each of the four types of discharge treatment, pre-print flushing treatment, pre-print purge treatment, sedimentation discharge purge treatment, and user purge treatment, the nozzles are used when the liquid is discharged from the nozzle 46 in each discharge treatment. The discharge conditions are set so that the discharge amount is equal to or more than the minimum discharge amount required for the recovery of the discharge property of 46. Then, these ejection conditions need to be changed according to the viscosity of the ink in the nozzle 46 in order to restore the ejection property of the nozzle 46 in the ejection process. The minimum amount of discharge required for recovering the discharge property of the nozzle 46 for each of the above four types of discharge treatment is set based on experiments, simulations, and the like. For example, in the present embodiment, the minimum amount of discharge required for recovering the ejection property of the nozzle 46 in the pre-printing flushing treatment is the flow path of the flow path from the throttle portion 82 to the nozzle 46 via the pressure chamber 83. The amount is set to correspond to the capacity.

On the other hand, the periodic purge process is not a discharge process performed after receiving a print instruction from the external device 200 and before executing the print process. In addition, unlike the user purge process, it is not an discharge process that is executed triggered by an operation input from the user. Therefore, as shown in FIG. 6, if the decrease in the discharge property of the nozzle 46 can be suppressed by this periodic purge discharge process, it is not always necessary to restore the discharge property of the nozzle 46. Therefore, regarding the discharge conditions of the regular purge, when the liquid is discharged from the nozzle 46 in this regular purge discharge process, the discharge amount is smaller than the minimum discharge amount required for the recovery of the discharge property of the nozzle 46. It is set to the discharge condition.

Further, as described above, in the present embodiment, the amount of ink discharged in the periodic purge process is the air when the air A in the supply tube 22 moves only by the periodic purge process and reaches the air storage chamber 65. The volume of A is set to be less than the capacity of the air storage chamber 65. Here, when the viscosity of the ink existing in the ink flow path 30 from the needle 41b to the nozzle 46 increases, the amount of ink actually discharged by each periodic purge process is, strictly speaking, the set ink. It will be less than the amount of emissions. Therefore, it can be assumed that the volume of the air A in the supply tube 22 when it reaches the air storage chamber 65 becomes larger than the capacity of the air storage chamber 65. However, the air A in the supply tube 22 moves to the air storage chamber 65 side even when a discharge process or a print process other than the periodic purge process is executed. Therefore, it is extremely unlikely that the volume of the air A in the supply tube 22 when it reaches the air storage chamber 65 will be equal to or larger than the capacity of the air storage chamber 65.

As described above, it is not necessary to strictly set the discharge conditions of the periodic purge discharge process according to the viscosity of the ink in the nozzle 46.

Therefore, in the present embodiment, the CPU 101 has the four types of discharge processing of the pre-print flushing process, the pre-print purge process, the sedimentation discharge purge process, and the user purge process in the nozzle 46 estimated by the in-nozzle viscosity estimation process. Based on the viscosity information of the ink, a condition change process for changing the discharge condition is executed.

In the present embodiment, the pre-printing flushing process is configured to change only the condition of the number of flushing occurrences according to the viscosity of the ink in the nozzle 46. As a modification, it may be configured to change only the condition regarding the shape of the drive waveform of the drive signal output to the individual electrode 89 according to the viscosity of the ink in the nozzle 46, and the flushing frequency may be changed. It may be configured to change both the conditions and the conditions regarding the shape of the drive waveform.

Further, in the present embodiment, in the pre-printing purge process, the sediment discharge purge process, and the user purge process, the rotation time, rotation speed, and torque of the suction pump 51 are determined according to the viscosity of the ink in the nozzle 46, respectively. It is configured to change three conditions. It is not always necessary to change the three conditions of the suction pump 51, that is, the rotation time, the rotation speed, and the torque, and at least one of these three conditions is changed according to the viscosity of the ink in the nozzle 46. It may be configured as follows.

The non-volatile memory 104 stores the discharge condition change information 125 that is referred to during this condition change process. The discharge condition change information 125 is information indicating the relationship between the discharge conditions of each of the above four types of discharge treatments and the viscosity of the ink in the nozzle 46. Therefore, the CPU 101 can determine the ejection conditions of each of the four types of ejection processing based on the viscosity of the ink in the nozzle 46 estimated by the in-nozzle viscosity estimation processing and the ejection condition change information 125. In the present embodiment, the discharge condition change information 125 has the discharge conditions of each of the four types of discharge treatments so that the higher the viscosity of the ink in the nozzle 46, the larger the discharge amount of the ink discharged from the nozzle 46. It is stipulated.

On the other hand, regarding the periodic purge process, the discharge conditions are not changed based on the viscosity of the ink in the nozzle 46 estimated by the viscosity estimation process in the nozzle. That is, the three conditions of the rotation time, the rotation speed, and the torque of the suction pump 51 at the time of each periodic purge process do not change depending on the estimated viscosity of the ink in the nozzle 46. As a result, it is possible to suppress an increase in ink consumption while reducing the processing load of the CPU 101 related to the change of the discharge condition. The non-volatile memory 104 stores periodic purge processing setting information 126 that defines discharge conditions for periodic purge processing. The CPU 101 executes each periodic purge process according to the discharge conditions specified in the periodic purge process setting information 126.

(Operation of inkjet printer)
Next, an example of the processing operation related to the ejection process of the printer 1 will be described with reference to FIG. 7.

First, the CPU 101 determines whether or not a print command has been received from the external device 200 (S1). When it is determined that the print command has been received (S1: YES), the CPU 101 determines the current count value of the total supply amount count information 121, the viscosity table 124 in the cartridge, and the time of the previous execution of the print process or the discharge process. The in-nozzle viscosity estimation process for estimating the viscosity of the ink in the nozzle 46 is executed based on the elapsed time from (S2). Next, the CPU 101 determines whether or not the viscosity of the ink estimated by the in-nozzle viscosity estimation process is equal to or higher than the second threshold value (S3). When it is determined that the viscosity of the ink is equal to or higher than the second threshold value (S3: YES), the CPU 101 determines that the sediment discharge purge process is to be executed, and the discharge conditions of the sediment discharge purge process are estimated by the process of S2. It is determined based on the viscosity of the non-volatile memory 104 and the discharge condition change information 125 of the non-volatile memory 104 (S4). After that, the CPU 101 executes a sedimentation discharge purge process in which the purge device 9 performs a suction purge according to the determined discharge conditions (S5).

When it is determined in the process of S3 that the viscosity of the ink estimated in the process of S2 is less than the second threshold value (S3: NO), the CPU 101 determines whether or not the viscosity is equal to or higher than the first threshold value (S6). .. When it is determined that the viscosity is equal to or higher than the first threshold value (S6: YES), the CPU 101 determines that the pre-printing purge process is to be executed, and sets the discharge conditions of the pre-printing purge process to the ink viscosity estimated by the process of S2. , And the determination is made based on the discharge condition change information 125 of the non-volatile memory 104 (S7). After that, the CPU 101 executes a pre-printing purge process for causing the purge device 9 to perform a suction purge according to the determined discharge conditions (S8).

When it is determined in the processing of S6 that the viscosity of the ink estimated in the processing of S2 is less than the first threshold value (S6: NO), the CPU 101 performs after the processing of S5 is completed or after the processing of S8 is completed. The discharge conditions of the pre-print flushing process are determined based on the viscosity of the ink estimated in the process of S2 and the discharge condition change information 125 of the non-volatile memory 104 (S9). After that, the CPU 101 executes a pre-print flushing process in which the actuator 45 of the head 5 performs flushing according to the determined discharge conditions (S10). After that, the CPU 101 controls the carriage drive motor 20, the head 5, and the like, and executes a printing process for printing an image on the paper P in accordance with a printing command received from the external device 200 (S11). After that, the CPU 101 calculates and calculates the amount of ink discharged or ejected from the nozzle 46 between the time when the print command is received in the process of S1 and the time when the print process related to the print command is completed. The amount of consumption is added to the count value of the total supply amount count information 121 (S12). When the process of S12 is completed, the process returns to the process of S1.

When it is determined in the process of S1 that the print command has not been received (S1: NO), the CPU 101 determines whether or not the execution command of the discharge process (user purge process) has been received from the user via the touch panel 161. Judgment (S13). When it is determined that the execution command of the user purge process has been received from the user (S13: YES), the in-nozzle viscosity estimation process similar to the process of S2 is executed (S14). After that, the CPU 101 determines the discharge conditions of the user purge process based on the viscosity of the ink estimated in the process of S14 and the discharge condition change information 125 of the non-volatile memory 104 (S15). After that, the CPU 101 executes a user purge process for causing the purge device 9 to perform a suction purge according to the determined discharge conditions (S16). Then, the CPU 101 adds the amount of ink discharged from the nozzle 46 during this user purge process to the count value of the total supply amount count information 121 (S17), and returns to the process of S1.

When it is determined in the process of S13 that the execution command of the user purge process is not received from the user (S13: NO), the CPU 101 determines whether or not one month has passed from the previous execution time of the periodic purge process. (S18). When it is determined that one month has passed (S18: YES), the CPU 101 executes a periodic purge process for causing the purge device 9 to perform a suction purge in accordance with the discharge conditions predetermined in the periodic purge process setting information 126. (S19). Then, the CPU 101 adds the amount of ink discharged from the nozzle 46 during this periodic purge process to the count value of the total supply amount count information 121 (S20), and returns to the process of S1.

As described above, according to the present embodiment, the discharge conditions of the periodic purge process are not changed according to the viscosity estimated by the in-nozzle viscosity estimation process. As a result, it is possible to suppress an increase in ink consumption while reducing the processing load related to the periodic purge process. On the other hand, the four types of discharge conditions, pre-print flushing treatment, pre-print purge treatment, sedimentation discharge purge treatment, and user purge treatment, can be changed according to the viscosity estimated by the in-nozzle viscosity estimation processing. When the process is executed, the ejection property of the nozzle can be reliably restored.

In the embodiment described above, the purge device 9 and the actuator 45 of the head 5 each correspond to a “liquid discharge unit”. The CPU 101 corresponds to the "control unit". Each of the four types of discharge treatment, pre-print flushing treatment, pre-print purge treatment, sedimentation discharge purge treatment, and user purge treatment, corresponds to the "first discharge treatment", and the discharge conditions of these four types of discharge treatment are "first". Corresponds to "emission conditions". The regular purge process corresponds to the "second discharge process", and the discharge condition of the regular purge process corresponds to the "second discharge condition". The process of determining the discharge conditions according to the estimated viscosities of S4, S7, S9, and S15 corresponds to the "condition change process". The process of receiving a print instruction from the external device 200 of S1 corresponds to the "print instruction reception process". The process of receiving the execution command of the user purge process in S13 from the user corresponds to the "discharge instruction reception process".

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the ink stored in the ink cartridge 42 may be dye ink. In this case, the sedimentation discharge purge process is not performed. Further, when the pre-printing purge process or the settling discharge purging process is executed after receiving the print command and before executing the print process, the pre-print flushing process may be omitted.

Further, the user purge process is configured to be executed when the touch panel 161 receives an operation input from the user, but is executed when the communication interface 110 receives the operation input from the user via the external device 200. It may be configured to be.

Further, the "first discharge process" is not limited to four types of pre-print flushing process, pre-print purge process, sedimentation discharge purge process, and user purge process, and the nozzle is used when ink is discharged from the nozzle 46. The process may be such that the purge device 9 and the actuator are controlled under the discharge conditions such that the discharge amount is equal to or larger than the minimum discharge amount required for the recovery of the discharge property of 46. Further, four types of discharge conditions of pre-print flushing treatment, pre-print purge treatment, sedimentation discharge purge treatment, and user purge treatment have been changed so that the higher the viscosity in the nozzle 46, the larger the discharge amount. It is not limited to this. For example, in the pre-printing purge process and the user purge process, the discharge conditions may be changed so that the higher the viscosity of the ink in the nozzle 46, the higher the negative pressure in the nozzle cap 55a.

The "second discharge process" is not limited to the periodic purge process, and when the ink is discharged from the nozzle 46, the ink is discharged with a discharge amount smaller than the minimum discharge amount required to restore the ejection property of the nozzle 46. Any process may be used as long as it is a process of controlling the purge device 9 and the actuator under the discharge conditions. For example, if the ejection process for ejecting ink from the nozzle 46 is performed after receiving the print instruction and before the start of the printing process, the ejection process executed at any other opportunity is referred to as the "second ejection process". May be good. Further, the CPU 101 may be configured to be able to execute a periodic flushing process for flushing the actuator 45 of the head 5 as a "second discharge process" every time a predetermined period elapses. Similar to the periodic purge process, this periodic flushing process is also a discharge process that does not require the ejection property of the nozzle 46 to be restored. Therefore, it is not necessary to change the discharge conditions of the periodic flushing treatment according to the viscosity of the ink in the nozzle 46.

The in-nozzle viscosity estimation process may be any process for estimating the viscosity of the ink existing in the flow path region including at least the nozzle 46. Therefore, for example, the in-nozzle viscosity estimation process may be a process for estimating the viscosity of ink existing in a flow path that affects ink ejection, such as a flow path from the pressure chamber 83 to the inside of the nozzle 46.

The actuator that applies ejection energy to the ink in the nozzle 46 is an actuator that imparts ejection energy to the ink by changing the volume of the pressure chamber 83 communicating with the nozzle 46, but the present invention is not limited to this. For example, an actuator may be used in which bubbles are generated in the pressure chamber by heating to apply ejection energy to the ink.

The ink discharge operation executed by the purging device 9 was a suction purging in which a suction force is applied to the nozzle 46. For example, a pressure pump is provided in the middle of the supply tube 22 and the pressure pump is driven. A pressure purge may be performed in which the ink is discharged from the nozzle 46 by supplying the ink to the head 5. Further, the purging device may be enabled to perform both suction purging and pressure purging.

The present invention can also be applied to a so-called line-type inkjet printer that prints an image on paper conveyed by a conveying mechanism with the inkjet head fixed. Further, in the above, an example in which the present invention is applied to a printer that ejects ink from a nozzle to print on paper P has been described, but the present invention is not limited to this. For example, the present invention can be applied to a liquid ejection device that ejects a liquid other than ink, such as a material for a wiring pattern to be printed on a wiring board, for printing.

1 Inkjet printer (liquid ejection device)
9 Purge device 45 Actuator 51 Suction pump (rotary pump)
101 CPU
110 Communication interface 161 Touch panel

Claims (8)

A head with a nozzle that discharges liquid,
Liquid discharge part and
Equipped with a control unit
The control unit
The first discharge process for controlling the liquid discharge unit under the first discharge condition such that when the liquid is discharged from the nozzle, the liquid is discharged with a discharge amount equal to or larger than the minimum discharge amount required for recovery of the discharge property of the nozzle. When,
A second discharge that controls the liquid discharge unit under a second discharge condition such that when the liquid is discharged from the nozzle, the liquid is discharged with a discharge amount smaller than the minimum discharge amount required for recovering the discharge property of the nozzle. Processing and
Is feasible and
Further, the control unit
Viscosity information acquisition processing for acquiring viscosity information regarding the viscosity of the liquid in the head, and
According to the viscosity information acquired by the viscosity information acquisition process, only the first discharge condition of the first discharge condition and the second discharge condition is discharged to the minimum necessary for recovering the discharge property of the nozzle. Condition change processing to change while satisfying more than the amount of emissions,
A liquid discharge device characterized by being feasible. The liquid discharge unit has a rotary pump for forcibly discharging the liquid in the head from the nozzle.
The first discharge condition includes at least one condition of the rotation time of the rotary pump, the rotation speed of the rotary pump, and the torque of the rotary pump.
The control unit
In the condition change process
The liquid discharge device according to claim 1, wherein at least one condition of the rotation time of the rotary pump, the rotation speed of the rotary pump, and the torque of the rotary pump is changed. The control unit
The liquid discharge device according to claim 1 or 2, further comprising an interface for receiving an instruction from a user to execute the first discharge process. The control unit
A printing process in which a liquid is ejected from the nozzle of the head to print an image on a recording medium based on the print data.
A print instruction reception process for receiving a print instruction instructing execution of the print process, and a print instruction reception process.
Is feasible and
3. The liquid discharge device according to any one item. The control unit
The liquid discharge device according to claim 4, wherein the first discharge process is executed after the print instruction is received by the print instruction reception process and before the print process is executed. The control unit
The liquid discharge device according to any one of claims 1 to 5, wherein the second discharge process is executed every time a predetermined time elapses. The control unit
In the condition change process
Claims 1 to 6 are characterized in that the first discharge condition is changed so that the higher the viscosity indicated by the viscosity information acquired by the viscosity information acquisition process, the larger the amount of liquid discharged from the nozzle. The liquid discharge device according to any one of the above. The head ejects pigment ink supplied from an ink tank that stores pigment ink from the nozzle.
The control unit
In the viscosity information acquisition process,
The liquid according to any one of claims 1 to 7, wherein the sedimentation information regarding the amount of sedimentation of the pigment in the ink tank is acquired, and the viscosity information is calculated and acquired based on the sedimentation information. Discharge device.

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