JP2019064058A - Ink jet recording apparatus, viscosity estimation method, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately estimate the viscosity of a pigment ink flowing out from an outlet of a second tank. An inkjet recording device is a first tank for storing pigment ink, and has a mounting portion on which a first tank having a supply port is mounted at a lower portion and an inflow port communicating with a supply port of the first tank. A second tank having an outlet located below the inlet and an inkjet head connected to the outlet are provided. The inkjet recording apparatus has a first viscosity distribution, which is a viscosity distribution of the pigment ink in the height direction in the first tank mounted on the mounting portion, and a viscosity distribution of the pigment ink in the height direction in the second tank. 2 Viscosity distributions are acquired respectively, and based on the acquired viscosity information of the first tank or less in the first viscosity distribution and the viscosity information of the second tank or less in the second viscosity distribution, Estimate the viscosity of the pigment ink flowing out of the outlet. [Selection diagram] FIG. 4

Description

  The present invention relates to an inkjet recording apparatus, a viscosity estimation method, and a storage medium.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus provided with a head for discharging ink supplied from a tank for storing ink is known. In this type of inkjet recording apparatus, when the ink in the tank runs out, there is a problem that air in the tank intrudes into the ink supply path to the head. As a countermeasure against this problem, Patent Document 1 discloses a configuration in which a sub tank (second tank) is interposed between a main tank (first tank) for storing ink and a head. In this configuration, the outlet of the sub tank that discharges the ink to the head is disposed below the inlet of the sub tank that the ink from the main tank flows. Therefore, even if the ink in the main tank runs out, the ink remains in the area below the inlet in the sub tank, preventing air from entering the ink supply path to the head. can do.

JP 2008-238530 A

  A pigment ink may be employed as an ink used for the inkjet recording apparatus. The pigment ink has the advantage of improving the clarity and the like of the printed image, but on the other hand, there is a problem that the pigment settles when it is in a stationary state for a long time. Therefore, in the tank for storing the pigment ink, when it is in the standing state for a long time, the pigment settles, thereby generating a viscosity distribution in which the viscosity of the pigment ink locally increases at the bottom of the tank.

  In addition, since the ejection characteristics of the head and the like largely depend on the viscosity of the ink, it is important to estimate the viscosity of the ink supplied to the head.

  Here, as described in Patent Document 1, in the configuration in which the second tank is interposed between the first tank and the head, when the pigment ink is employed as the used ink, the pigment which has flowed out from the lower portion of the first tank The ink mixes with the pigment ink in the second tank and is eventually supplied to the head. Therefore, it can not be said that the viscosity of the pigment ink supplied from the second tank to the head is accurately estimated only by the viscosity estimation of the pigment ink flowing out from the inside of the first tank in which the ink is stored.

  Therefore, an object of the present invention is to provide an ink jet recording apparatus, a viscosity estimation method, and a storage medium capable of accurately estimating the viscosity of pigment ink flowing out from the outlet of the second tank.

  In order to solve the above problems, an inkjet recording apparatus according to the present invention is a first tank for storing pigment ink, and a mounting unit to which a first tank having a supply port at the lower part is mounted, and the first tank A second tank having an inlet communicating with the supply port and an outlet disposed below the inlet, an ink jet head connected to the outlet, and a control unit; The control unit is a first viscosity distribution that is a viscosity distribution of pigment ink in the height direction in the first tank mounted to the mounting unit, and a viscosity distribution of the pigment ink in the height direction in the second tank. Each second viscosity distribution is acquired, and viscosity information less than or equal to the first height of the first tank in the acquired first viscosity distribution, and less than or equal to the second height of the second tank in the second viscosity distribution Based on viscosity information Estimating the viscosity of the pigment ink is discharged from the serial outlet.

  The viscosity estimation method of the present invention is a first tank for storing pigment ink, and a mounting portion to which a first tank having a supply port is mounted at the lower part, and a flow communicating with the supply port of the first tank Viscosity of pigment ink discharged from the outlet in an ink jet recording apparatus having a second tank having an inlet and an outlet disposed below the inlet, and an inkjet head connected to the outlet The first viscosity distribution, which is the viscosity distribution of pigment ink in the height direction in the first tank mounted to the mounting portion, and the height direction in the second tank. A viscosity distribution acquisition step of acquiring a second viscosity distribution which is a viscosity distribution of the pigment ink, and a second of the first tank in the first viscosity distribution acquired by the viscosity distribution acquisition step A viscosity estimation step of estimating the viscosity of the pigment ink flowing out from the outlet based on the viscosity information not higher than the height and the viscosity information lower than the second height of the second tank in the second viscosity distribution; including.

  Further, the storage medium of the present invention is a first tank for storing pigment ink, and a mounting portion to which a first tank having a supply port at the lower part is mounted, and a flow communicating with the supply port of the first tank. Viscosity of pigment ink discharged from the outlet in an ink jet recording apparatus having a second tank having an inlet and an outlet disposed below the inlet, and an inkjet head connected to the outlet Storage medium for storing a program to be executed by an estimation device for estimating the viscosity, wherein the program is a viscosity distribution of pigment ink in the height direction in the first tank attached to the attachment unit in the estimation device. Viscosity distribution acquisition processing for acquiring a first viscosity distribution and a second viscosity distribution which is a viscosity distribution of pigment ink in the height direction in the second tank, and the viscosity distribution acquisition processing Based on the viscosity information obtained by the first viscosity distribution and below the first height of the first tank in the first viscosity distribution and the viscosity information below the second height of the second tank in the second viscosity distribution, And a viscosity estimation process for estimating the viscosity of the pigment ink flowing out of the outlet.

The first viscosity distribution, which is the viscosity distribution of the pigment ink in the height direction in the first tank, and the second viscosity distribution, which is the viscosity distribution of the pigment ink in the height direction in the second tank, are, for example, the following aspects: It is inferred from this that the viscosity distributions differ from one another. That is, with regard to the viscosity change of the ink in the tank caused by the sedimentation of the pigment, it is easy to settle the pigment in the tank (is it easy to accumulate)? When the ink is consumed by the head, The tendency of the ink to flow out greatly affects it. Here, with respect to the ease of settling of the pigment, the shape of the tank etc. is a major factor. In addition, the flow path shape and the like in the vicinity of the opening through which the ink in the tank flows out influences which portion in the tank the ink tends to flow out. For this reason, the first tank and the second tank having different applications are different from each other in any of the shape of the tank and the flow path shape around the opening where the ink flows out. It is assumed that the viscosity distributions will also be different from one another. Therefore, the viscosity distribution of the pigment ink in the first tank and the viscosity distribution of the pigment ink in the second tank are respectively acquired, and flow out from the outlet of the second tank based on the viscosity distribution of both of them. It is preferable to estimate the viscosity of the pigment ink.
In addition, the inventor of the present application has found that the viscosity of the pigment ink flowing out from the outlet of the second tank is the pigment ink existing in a region below a predetermined height in the first tank before the outflow, and the second tank It has been found that it is influenced by the viscosity of the pigment ink present in the area below the predetermined height.
Therefore, in the present invention, as in the above-described configuration, the first viscosity distribution and the second viscosity distribution are acquired, and the acquired viscosity information of the first tank in the first viscosity distribution or less and the second viscosity and the second viscosity The estimation accuracy can be enhanced by estimating the viscosity of the pigment ink flowing out from the outlet based on the viscosity information of the second tank or lower in the distribution.
Also, the viscosity of the pigment ink discharged from the outlet of the second tank is higher than the pigment ink present in the region above the first height in the first tank and the second height in the second tank. Hardly affected by the pigment ink present in the region of For this reason, it is possible to estimate the viscosity by estimating the viscosity based on the viscosity information of the first tank below the first height in the first viscosity distribution and the viscosity information of the second tank below the second height in the second viscosity distribution. The viscosity estimation can be simplified as compared to the case of estimating the viscosity using all of the viscosity information of each of the 1 viscosity distribution and the second viscosity distribution.

It is a schematic block diagram of the ink jet printer concerning this embodiment. FIG. 2 is a block diagram schematically showing the electrical configuration of the inkjet printer. FIG. 2 is a vertical cross-sectional view schematically showing an inkjet head, a main tank, and a sub tank. It is a figure explaining each field in viscosity distribution of each of a main tank and a subtank, and the 1st height and the 2nd height. It is a figure explaining each field in viscosity distribution of each of a main tank and a subtank, and the 1st height and the 2nd height. (A) is a figure explaining a main tank viscosity table, (b) is a figure explaining a sub tank viscosity table, (c) and (d) explain the ink composition of each field in each of a main tank and a sub tank (E) is a figure explaining the ink composition of the ink which flowed out from the outlet. It is a flowchart explaining a viscosity estimation process. 5 is a flowchart illustrating processing operation of the inkjet printer.

  A schematic configuration of an inkjet printer 1 according to a preferred embodiment of the present invention will be described. The printer 1 is used in the attitude shown in FIG. The printer 1 includes a platen 2, a carriage 3, an inkjet head 4 (hereinafter simply referred to as a head 4), four tank mounting units 5, four sub tanks 6, a paper feed roller 7, a paper discharge roller 8, and a purge device 9. , A flushing receiver 10, a temperature sensor 160, a touch panel 161 (see FIG. 2), and a control device 100. In the following, the front side of the paper surface of FIG. 1 is defined as “upper” of the printer 1 and the rear side of the paper surface is defined as “lower” of the printer 1. Further, the front-rear direction and the left-right direction shown in FIG. 1 are defined as “front-rear direction” and “left-right direction” of the printer 1. The following description will be made using front, rear, left, right, upper and lower direction words as appropriate.

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

  The carriage 3 is attached to the two guide rails 15 and 16 and is movable in the left-right direction along the two guide rails 15 and 16 in a region facing the platen 2. Further, a driving 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. 2). As the pulley 18 is rotationally driven by the carriage drive motor 20, the drive belt 17 travels, whereby the carriage 3 reciprocates in the left-right direction. At this time, the head 4 mounted on the carriage 3 reciprocates in the left-right direction together with the carriage 3.

  The four tank mounting portions 5 are arranged side by side in the left-right direction in front of the carriage 3 (head 4). The main tank 30 is detachably mounted to each tank mounting portion 5. Black, yellow, cyan, and magenta pigment inks are stored in the four main tanks 30 mounted to the four tank mounting portions 5 respectively. Each of the four tank mounting units 5 is provided with a mounting detection sensor 130 (see FIG. 2) for detecting whether the main tank 30 is mounted on the tank mounting unit 5 or not.

  The four sub tanks 6 are arranged in the left-right direction in front of the carriage 3 and behind the four tank mounting portions 5. The four subtanks 6 correspond to the four tank mounting parts 5. Each sub tank 6 is a tank for gas-liquid separation, and when the main tank 30 is mounted on the corresponding tank mounting portion 5, ink is supplied from the main tank 30 in communication with the main tank 30. ing. Also, the sub tank 6 is connected to the head 4 via a flexible supply tube 22. The configurations of the main tank 30 and the sub tank 6 will be described later.

  The head 4 is mounted on the carriage 3. The head 4 has a head body 13 and a buffer tank 14. A tube joint 21 is integrally provided in the buffer tank 14. Then, one end of each of the four supply tubes 22 is detachably connected to the tube joint 21. The other end of each of the four supply tubes 22 is connected to each of the four sub tanks 6. Ink in the four main tanks 30 mounted to the tank mounting unit 5 is supplied to the buffer tank 14 through the sub tank 6 and the supply tube 22.

  The head main body 13 is attached to the lower part of the buffer tank 14. The head main body 13 has a flow path unit 44 and an actuator 45. The flow passage unit 44 is formed with an internal flow passage including a plurality of nozzles 46 formed on a nozzle surface 44 a (see FIG. 3) which is the lower surface thereof. The internal flow passage communicates with the buffer tank 14, and the plurality of nozzles 46 eject the ink supplied from the buffer tank 14 via the internal flow passage. The plurality of nozzles 46 are arranged in the front-rear direction to form a nozzle row 47, and four nozzle rows 47 are arranged in the left-right direction on the nozzle surface 44a. From the four nozzle rows 47, black, yellow, cyan and magenta inks are ejected in order from the nozzle row 47 located on the right side. The actuator 45 is for applying ejection energy to the ink in each nozzle 46 individually. For example, the actuator 45 changes the volume of a pressure chamber (not shown) communicating with the nozzle 46 to apply pressure to the ink, or generates air bubbles in the pressure chamber by heating to apply pressure to the ink. However, since the configuration itself of the actuator 45 is known, further detailed description is omitted here.

  Further, the head 4 is disposed above the main tank 30 and the sub tank 6 mounted to the tank mounting unit 5. As a result, a head difference occurs between the ink in the nozzle 46 and the liquid surface of the ink in the main tank 30 or the liquid surface of the ink in the sub tank 6, whereby the ink in the nozzle 46 is moved to the main tank 30 side. Negative pressure is applied. As a result, it is possible to prevent the ink from being ejected from the nozzle 46 at times other than printing.

  The paper feed roller 7 and the paper discharge roller 8 are rotationally driven in synchronization with each other by a conveyance motor 29 (see FIG. 2). The sheet feed roller 7 and the sheet discharge roller 8 cooperate to convey the sheet P placed on the platen 2 forward (in the conveyance direction).

  Then, the printer 1 alternately repeats an operation of conveying the sheet P in the conveyance direction by the sheet feeding roller 7 and the sheet discharging roller 8 and an ejection operation of ejecting the ink while moving the head 4 with the carriage 3 in the left and right direction. By doing this, a desired image or the like is printed on the sheet P. That is, the printer 1 of the present embodiment is a serial type ink jet printer.

  The flushing receiver 10 is disposed on the left side of the platen 2. When the carriage 3 is moved to position the head 4 at the flushing position, the plurality of nozzles 46 face the flushing receiver 10 up and down. Then, in the printer 1, in a state where the head 4 is positioned at the flushing position, the actuator 45 of the head 4 is driven to eject and discharge the thickened ink or the like from the nozzle 46 toward the flushing receiver 10. It can be done.

  The purge device 9 is for suppressing the decrease in the dischargeability of the nozzle 46 of the head 4 and performing a maintenance operation for recovering the dischargeability, and includes the cap unit 50, the suction pump 51, the waste liquid tank 52, and the like. Have.

  The cap unit 50 is disposed on the right side of the platen 2. When the carriage 3 moves to the right with respect to the platen 2, the cap unit 50 vertically opposes the cap unit 50. Further, the cap unit 50 is driven by the cap lifting motor 53 (see FIG. 2) and can be lifted and lowered in the vertical direction. The cap unit 50 includes a cap 55 which can be mounted in contact with the head 4. The cap 55 is made of, for example, a rubber material.

  When the head 4 faces the cap unit 50, the cap 55 faces the lower surface of the head body 13. In this state, the cap unit 50 is mounted on the head 4 when the cap unit 50 located at the separated position separated downward from the head 4 is raised to the capping position above the separated position by the cap lift motor 53. Be done. At this time, the cap 55 covers all the nozzles 46 belonging to the four nozzle rows 47 in common. The cap 55 is connected to a suction pump 51 which is a rotary pump.

  In the printer 1, the suction pump 51 is driven under the control of the control device 100 in a state where the cap 55 is attached to the head body 13 and covers the plurality of nozzles 46, thereby reducing the pressure in the cap 55 (suction). Suction purge can be performed in which ink is sucked and discharged from the plurality of nozzles 46, respectively. As a result, the highly viscous ink in the nozzle 46 is forcibly discharged from the nozzle 46, so that the dischargeability of the nozzle 46 can be recovered. The ink discharged by the suction purge is stored in the waste liquid tank 52.

  The temperature sensor 160 is disposed in the vicinity of the tank mounting unit 5 and measures the ambient temperature. The touch panel 161 is a user interface that can receive various operation inputs from the user and can display various setting screens, operation states, and the like to the user.

  As shown in FIG. 2, the control device 100 includes a central processing unit (CPU) 101, a read only memory (ROM) 102, a random access memory (RAM) 103, a non-volatile memory 104, an application specific integrated circuit (ASIC) 105, and the like. including. The ROM 102 stores programs executed by the CPU 101, various fixed data, and the like. The RAM 103 temporarily stores data (such as print data) necessary for program execution. The non-volatile memory 104 stores, for example, total outflow amount count information 121 described later. The ASIC 105 is connected to various devices or drives of the printer 1 such as the head 4 and the carriage drive motor 20. The ASIC 105 is also connected to an external device 200 such as a PC via the communication interface 110. Furthermore, the USB interface 111 is connected to the ASIC 105. The control device 100 is configured to be able to install the program 250 a and the like stored in the USB memory 250 via the USB interface 111.

  The CPU 101 controls the head 4, the carriage drive motor 20, and the like based on the print instruction received from the external device 200, and executes print processing for printing an image or the like on the sheet P. Further, the CPU 101 causes the purge device 9 to perform suction and purge, and causes the actuator 45 of the head 4 to perform flushing, thereby executing a discharge process for discharging ink from the nozzles 46 of the head 4.

  In the above description, the various processes performed by the control device 100 are described as being performed by the CPU 101. However, the various processes may be performed in cooperation with the CPU and an 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, processing may be performed by one ASIC alone.

  Next, configurations of the main tank 30 and the sub tank 6 will be described in order.

  As shown in FIG. 3, the main tank 30 mounted in the tank mounting portion 5 is arranged side by side with the sub tank 6 in the horizontal direction. More specifically, the main tank 30 is disposed adjacent to the sub tank 6 in the front-rear direction in the horizontal direction. The main tank 30 has a substantially rectangular parallelepiped shape, and an internal space 31 for storing ink is formed therein.

  In the main tank 30, a horizontally extending partition plate 32 is provided which divides the internal space 31 into an upper ink chamber 31a and a lower ink passage 31b. In the front end portion of the partition plate 32, a connection hole 32a penetrating vertically is formed. The ink chamber 31a and the ink flow path 31b communicate with each other through the connection hole 32a.

  At a position below the partition plate 32 in the rear wall 30a of the main tank 30, a supply port 33 which penetrates the rear wall 30a in the front-rear direction is formed. That is, the supply port 33 is formed in the ink flow path 31b. The supply port 33 is an opening for supplying the ink stored in the internal space 31 to the outside. In addition, a cylindrical ink supply portion 34 that protrudes rearward is provided in a portion of the rear wall 30 a where the supply port 33 is formed. The internal space of the ink supply unit 34 communicates with the internal space 31 via the supply port 33. The tip of the internal space 31 of the ink supply unit 34 is an insertion hole 34 a into which a needle 65 described later is inserted. The insertion hole 34 a is closed by a valve (not shown) when the main tank 30 is not mounted to the tank mounting portion 5. When the main tank 30 is mounted to the tank mounting portion 5, the insertion hole 34a is opened by a needle 65 described later of the sub tank 6 pushing the valve.

  An air communication port 35 is formed in the upper portion of the rear wall 30 a of the main tank 30 so as to penetrate the rear wall 30 a in the front-rear direction. The atmosphere communication port 35 communicates with the gas layer on the upper side of the liquid surface of the ink in the ink chamber 31 a and the outside (atmosphere). Although not shown, the air communication port 35 is reverse to restrict the flow of fluid from the ink chamber 31 a to the outside of the main tank 30 while permitting the flow of fluid from the outside of the main tank 30 to the ink chamber 31 a. A stop valve may be provided. In addition, the air communication port 35 may be provided with a gas permeable membrane that allows the passage of gas while blocking the transmission of a liquid such as ink. In addition, a flow path having a labyrinth structure may be provided outside the air communication port 35 so that the ink is unlikely to leak from the air communication port 35 to the outside.

  By the way, when transporting the printer 1 or the like, the printer 1 can be placed in a posture different from the use posture shown in FIG. For example, the posture of the printer 1 may be a posture in which the rear surface of the printer 1 is on the lower side. That is, the rear surface of the printer 1 may be located below the front surface. Then, the liquid level of the ink in the ink chamber 31a in the main tank 30 mounted in the tank mounting portion 5 is positioned above the head 4, and the ink in the nozzle 46 is mainly used as in the use posture. No negative pressure is applied to the tank 30 side. As a result, a large amount of ink in the main tank 30 present above the nozzles 46 of the head 4 may leak from the nozzles 46. However, in the present embodiment, the partition plate 32 is provided in the main tank 30, and the connection hole 32a communicating the ink chamber 31a and the ink flow path 31b is formed at the front end of the partition plate 32. There is. Therefore, when the rear face of the printer 1 is turned downward, the connection hole 32a is positioned at the uppermost position in the ink chamber 31a. As a result, the ink in the ink chamber 31a can be prevented from flowing out to the ink flow path 31b, and a large amount of ink can be prevented from leaking out from the nozzle 46.

  Next, the sub tank 6 will be described. The sub tank 6 mainly includes a rectangular parallelepiped main body portion 61 and a rectangular parallelepiped upper portion 62 extending upward from the upper portion of the main body portion 61. A lower storage chamber 61 a is formed in the main body portion 61, and an upper storage chamber 62 a is formed in the upper portion 62. The lower storage chamber 61a and the upper storage chamber 62a communicate with each other to form an internal space 60. The volume of the internal space 60 of the sub tank 6 is smaller than the volume of the internal space 31 of the main tank 30. The horizontal cross-sectional area of each height of the internal space 60 of the sub tank 6 is smaller than the bottom area of the internal space 60 of the main tank 30 or the horizontal cross-sectional area of each height.

  The upper storage chamber 62 a is located above the partition plate 32 of the main tank 30 when the main tank 30 is mounted to the tank mounting portion 5. The width in the left-right direction of the upper storage chamber 62a is the same as the width in the left-right direction of the lower storage chamber 61a, while the width in the vertical direction of the upper storage chamber 62a is greater than the width in the left-right direction of the lower storage chamber 61a. Too short. Therefore, the horizontal cross-sectional area of each height of the upper storage chamber 62a is smaller than the horizontal cross-sectional area of each height of the lower storage chamber 61a. In addition, the horizontal cross-sectional area of each height of the upper storage chamber 62a is significantly smaller than the horizontal cross-sectional area of each height of the ink chamber 31a of the main tank 30 (for example, the horizontal cross-sectional area of the upper storage chamber 62a is 5% of the horizontal sectional area of the ink chamber 31a of the main tank 30).

  At the top of the front wall 62b of the upper portion 62, an air communication port 63 is formed to penetrate the front wall 62b in the front-rear direction. The atmosphere communication port 63 communicates with the gas layer above the liquid surface of the ink stored in the internal space 60 and the outside (atmosphere). Although not shown, the atmosphere communication port 63 may be provided with a gas permeable membrane that allows the passage of gas while blocking the permeation of a liquid such as ink. Further, a flow path having a labyrinth structure may be provided outside the air communication port 63 so that the ink is unlikely to leak from the air communication port 63 to the outside.

  The front wall 61 b of the main body portion 61 is formed with an inlet 64 penetrating the front wall 61 b in the front-rear direction. That is, the inflow port 64 is formed in the lower storage chamber 61a. The inlet 64 is an opening through which ink from the outside of the subtank 6 flows. Moreover, the cylindrical needle 65 which protrudes ahead is provided in the formation part of the said inflow port 64 in the front wall 61b. The internal space of the needle 65 is in communication with the internal space 60 of the sub tank 6 via the inlet 64. When the main tank 30 is mounted to the tank mounting portion 5, the needle 65 is inserted into the insertion hole 34 a of the main tank 30, whereby the supply port 33 of the main tank 30 and the sub tank 6 via the needle 65. And the inlet 64 of the As a result, the ink stored in the internal space 31 of the main tank 30 can be supplied to the internal space 60 of the sub tank 6 through the supply port 33 and the inflow port 64.

  At the lower part of the rear wall 61c of the main body portion 61, an outlet 66 penetrating the rear wall 61c in the front-rear direction is formed. That is, the outlet 66 is formed in the lower storage chamber 61a. The outlet 66 is an opening for flowing out the ink stored in the internal space 60 of the sub tank 6 to the outside. A supply tube 22 is connected to the outlet 66 so that the ink stored in the main tank 30 and the sub tank 6 can be supplied to the head 4 through the supply tube 22.

  The outlet 66 is disposed below the inlet 64. Further, the outlet 66 is disposed below the internal space 31 of the main tank 30 mounted to the tank mounting portion 5.

  At a position on the front wall 61 b of the main body portion 61 below the needle 65, a convex portion 67 that protrudes forward is provided. Inside the convex portion 67, a detection chamber 67a which constitutes a part of the internal space 60 is formed. Moreover, the convex part 67 is comprised with the resin member which has light transmittance.

  In the lower storage chamber 61a, a float mechanism 69 which is rotatable about a support shaft 68 provided in the main body portion 61 is provided. The float mechanism 69 has an arm portion 69a extending forward from the support shaft 68, a float portion 69b extending rearward from the support shaft 68, and a shielding portion 69c provided at the tip of the arm portion 69a. ing.

  The float portion 69 b is formed in a hollow shape so that the average specific gravity thereof is smaller than the specific gravity of the ink. The arm portion 69a is set such that its weight is smaller than that of the float portion 69b, and the buoyancy exerted by the float portion 69b is smaller when it is immersed in ink.

  In the above configuration, when the liquid level position of the ink stored in the lower storage chamber 61a is at the height position equal to or higher than the predetermined detection position, the float portion 69b is immersed in the ink, and the float portion is floated by buoyancy. The balance of weight between 69 b and the arm 69 a is reversed, and the float mechanism 69 pivots around the support shaft 68 in the direction in which the float 69 b ascends. At this time, the shielding portion 69c moves obliquely downward so as to enter the detection chamber 67a.

  On the other hand, when the liquid surface of the ink stored in the lower storage chamber 61a is at a height position lower than the above detection position, the float mechanism 69 moves the float portion 69b downward with respect to the support shaft 68. At this time, the shielding portion 69c moves so as to withdraw obliquely upward from the detection chamber 67a. As described above, the shielding portion 69c is displaced in accordance with the vertical displacement of the liquid surface of the ink in the lower storage chamber 61a.

  In addition, the printer 1 is provided with a remaining amount detection sensor 120. The remaining amount detection sensor 120 is a transmission type light sensor provided with a light emitting element and a light receiving element (not shown) opposed to each other with the convex portion 67 of the sub tank 6 interposed therebetween. The detection chamber 67a in the convex portion 67 is disposed in the optical path between the light emitting element and the light receiving element of the remaining amount detection sensor 120. Therefore, when the shielding portion 69c of the float mechanism 69 is positioned in the detection chamber 67a, the light receiving element can not receive the light emitted from the light emitting element, and can be received when the shielding portion 69c is displaced and retreats from the detection chamber 67a. . The remaining amount detection sensor 120 controls the information on the position of the shielding portion 69c, that is, the liquid level of the ink stored in the lower storage chamber 61a according to the presence or absence of the light received from the light emitting element of the light receiving element. Output to 100. Thereby, based on the output result from the remaining amount detection sensor 120, the CPU 101 of the control device 100 determines whether the liquid level of the ink in the lower storage chamber 61a is less than the detection position (hereinafter, the near empty state). Can be judged. In this embodiment, the detection position is set higher than the outlet 66 and set lower than the inlet 64.

  As a modification, the convex portion 67 may not be provided on the front wall 61 b of the main body portion 61, and may be protruded upward from the upper wall 61 d of the main body portion 61. In this case, the arm portion 69a of the float mechanism 69 extends upward from the support shaft 68. As a result, the shielding portion 69c provided at the tip of the arm portion 69a is displaced in the left-right direction according to the displacement of the liquid surface in the lower storage chamber 61a in the vertical direction. Even in this configuration, the CPU 101 can determine whether it is near empty based on the output result from the remaining amount detection sensor 120. Further, in the case of this configuration, since the convex portion 67 is not provided on the front wall 61b of the main body portion 61, a space is generated below the connection portion between the needle 65 and the ink supply portion 34. It is possible to arrange an ink receiver or the like that can receive the ink.

  Next, the flow of ink after the main tank 30 is mounted to the tank mounting portion 5 will be described. When the main tank 30 is mounted to the tank mounting portion 5, the needle 65 of the sub tank 6 is inserted into the insertion hole 34a of the main tank 30, and the supply port 33 of the main tank 30 and the inlet 64 of the sub tank 6 mutually It communicates. Thus, the ink in the internal space 31 of the main tank 30 is supplied to the internal space 60 of the sub tank 6.

  Here, the internal space 31 of the main tank 30 is open to the atmosphere by the atmosphere communication port 35. Further, the internal space 60 of the subtank 6 is open to the atmosphere by the atmosphere communication port 63. Therefore, the supply of the ink from the main tank 30 to the sub tank 6 is performed until the liquid level of the ink in the main tank 30 and the liquid level of the ink in the sub tank 6 become equal to each other by the water head pressure. . Thereafter, when the ink is supplied from the sub tank 6 to the head 4 through the outlet 66 by discharging or discharging the ink from the nozzle 46 by printing processing, discharging processing, or the like, the liquid of the ink in the main tank 30 The surface and the liquid surface of the ink in the sub tank 6 are lowered while maintaining the same height.

  By the way, in the case where the supply port 33 of the main tank 30 is directly connected to the supply tube 22, if the ink is discharged or discharged from the nozzle 46 even after the ink in the main tank 30 is exhausted, Air intrudes into the supply tube 22. As a result, there arises a problem that the dischargeability of the nozzle 46 is deteriorated by the air. As a countermeasure against this problem, in order to prevent air from entering the supply tube 22, when the remaining amount of ink in the main tank 30 becomes less than a predetermined amount which is larger than zero, the main screen on the touch panel 161 It is also conceivable to display a replacement screen or the like prompting replacement of the tank 30, and allow the user to replace the main tank 30. However, in this case, the ink is replaced in a state where the ink remains in the main tank 30 mounted to the tank mounting portion 5.

  On the other hand, in the present embodiment, since the sub-tank 6 for gas-liquid separation is interposed between the main tank 30 and the supply tube 22, the above problem is solved.

  As described above, the outlet 66 of the subtank 6 is disposed below the inlet 64. That is, it is disposed below the main tank 30 mounted to the tank mounting portion 5. Therefore, even when the ink in the main tank 30 runs out, the ink is stored in the lower storage chamber 61a of the sub tank 6 (above the outlet 66). As a result, even if the ink in the main tank 30 runs out, air does not immediately enter the supply tube 22.

  Thereafter, when the CPU 101 determines that the liquid level of the ink in the sub tank 6 has become less than the detection position based on the output result from the remaining amount detection sensor 120, the touch panel 161 is used for the main tank 30. Display a replacement screen prompting for replacement. In addition, since the said detection position is a position above the outflow port 66, at this time, the air has not penetrated into the supply tube 22. Therefore, in the present embodiment, the ink in the main tank 30 can be effectively used while suppressing air from entering the supply tube 22.

  By the way, when performing discharge processing such as suction purge and flushing, in order to recover the dischargeability of the nozzle 46, the discharge amount etc. of the ink to be discharged from the nozzle 46 is changed according to the viscosity of the ink in the nozzle 46 There is a need to. Therefore, for example, in the suction purge, it is necessary to change the driving conditions such as the rotation time and the rotation speed of the suction pump 51 so that the discharge amount increases as the viscosity of the ink in the nozzle 46 increases. In addition, in the flushing, as the viscosity of the ink in the nozzle 46 is higher, the drive condition of the actuator 45 is changed so that the number of times of discharging ink is increased, or the discharge amount per one discharge is increased. Need to change or Therefore, it is necessary to estimate the viscosity of the ink in the nozzle 46 with high accuracy.

  Here, the viscosity of the ink in the nozzle 46 changes depending on the viscosity of the ink as it flows out from the outlet 66 of the sub tank 6. The viscosity of the ink discharged from the outlet 66 is not always constant but changes. For this reason, in order to accurately estimate the viscosity of the ink in the nozzle 46, it is necessary to accurately estimate the viscosity of the ink flowing out of the outlet 66. Hereinafter, the reason why the viscosity of the ink flowing out from the outlet 66 changes will be described.

  As described above, the ink stored in the main tank 30 is a pigment ink. The pigment ink is present in a state in which the pigment is dispersed in a solvent, and when standing for a long time, the pigment having a large specific gravity settles to the bottom of the main tank 30. For this reason, in the main tank 30, a large amount of pigment settles on the bottom of the main tank 30 when it is in a stationary state for a long time. As a result, the pigment concentration of the pigment ink locally increases at the bottom of the main tank 30, and the viscosity also locally increases very much. On the other hand, in the main tank 30, the pigment ink in the vicinity of the liquid surface has a lower viscosity because the amount of the pigment decreases. Therefore, in the main tank 30, a viscosity distribution in which the viscosity of the ink is the highest at the bottom and the viscosity decreases as it goes upward is generated.

  As described above, the viscosity of the ink at the bottom of the main tank 30 increases because the amount of sedimentation of the pigment increases with time unless the ink is discharged from the supply port 33 to the sub tank 6. On the other hand, when the ink flows out from the supply port 33, the thickened ink in the bottom of the main tank 30 flows out. Therefore, as the ink flows out from the supply port 33, the viscosity of the ink at the bottom of the main tank 30 drops. Moreover, since the viscosity of the pigment ink decreases as the temperature in the main tank 30 increases, sedimentation of the pigment is promoted. Therefore, the viscosity distribution of the ink in the main tank 30 changes depending on the outflow amount of the ink flowing out from the supply port 33, the temperature in the main tank 30, the elapsed time from the mounting time mounted on the tank mounting portion 5, etc. It will be. As a result, the viscosity of the ink flowing out of the main tank 30 into the sub tank 6 via the supply port 33 changes.

  Further, in the sub tank 6 as well as in the main tank 30, a viscosity distribution in which the viscosity of the ink is the highest at the bottom and decreases as going upward is generated. Here, the larger the volume of the tank, the larger the amount of sedimentation of the pigment settled per unit time in a certain tank, and the larger the horizontal cross-sectional area of each height of the tank. As described above, the capacity of the internal space 60 of the sub tank 6 is smaller than the capacity of the internal space 31 of the main tank 30. Further, the horizontal cross-sectional area of each height of the internal space 60 of the sub tank 6 is smaller than the bottom area of the main tank 30 or the horizontal cross-sectional area of each height. For this reason, in the subtank 6, the sedimentation amount of the pigment settling per unit time is smaller than the sedimentation amount of the pigment settling per unit time in the main tank 30. As described above, since the sub tank 6 has a tank shape different from that of the main tank 30, the viscosity distribution in the sub tank 6 is different from the viscosity distribution of the main tank 30.

  Further, the ink supplied from the supply port 33 of the main tank 30 into the sub tank 6 mixes with the ink in the sub tank 6, and after its viscosity is reduced, finally, from the outlet 66 of the sub tank 6 to the head 4 And will be drained. More specifically, when a predetermined amount of ink flows out from the outlet 66 during a predetermined period, the predetermined amount of ink that has flowed out is the ink that was present in the main tank 30 at the start of the predetermined period. And the ink present in the sub tank 6 are mixed.

  As described above, the viscosity of the ink flowing out of the outlet 66 changes depending on various factors such as the outflow amount of ink flowing out of the outlet 66, the temperature in the main tank 30, and the elapsed time after the mounting time. become.

  Therefore, in the present embodiment, the CPU 101 estimates the viscosity of the ink flowing out from the outlet 66 each time a predetermined period (one month in the present embodiment) elapses, according to the viscosity estimation program 102a stored in the ROM 102. Execute viscosity estimation processing. In each of the viscosity estimation processes, the CPU 101 first acquires the viscosity distribution of the ink in the height direction in the main tank 30 attached to the tank attachment unit 5 and the viscosity distribution of the ink in the height direction in the sub tank 6. Then, the viscosity of the ink flowing out from the outlet 66 is estimated based on the acquired viscosity distribution. Hereinafter, matters to be premised on the viscosity estimation process will be described.

  In the present embodiment, as shown in FIGS. 4 and 5, the area below the liquid level of the ink in the main tank 30 is equally divided into five areas M1 to M5 in the height direction. The regions M1 to M5 are regions which are lower in the order of the region M1, the region M2, the region M3, the region M4, and the region M5. Further, the area below the liquid level of the ink in the sub tank 6 is also equally divided into five areas S1 to S5 in the height direction. The areas S1 to S5 are areas which are lower in the order of the area S1, the area S2, the area S3, the area S4, and the area S5. These areas M1 to M5 and S1 to S5 are areas obtained by equally dividing the areas below the liquid level of the ink in the main tank 30 and the sub tank 6, respectively. The area width in the direction becomes shorter. That is, the amount of ink present in each of the regions M1 to M5 and S1 to S5 decreases as the liquid level of the ink decreases.

  As shown in FIG. 2, the non-volatile memory 104 stores a main tank viscosity table 123 and a sub tank viscosity table 124. As shown in FIG. 6A, the main tank viscosity table 123 associates the respective regions M1 to M5 of the main tank 30 with viscosity information indicating the viscosity of the ink present in each of the regions M1 to M5. Table. Accordingly, the main tank viscosity table 123 represents the viscosity distribution of ink in the height direction in the main tank 30 (hereinafter, main tank viscosity distribution). Further, in the sub tank viscosity table 124, as shown in FIG. 6B, the respective regions S1 to S5 of the sub tank 6 are associated with viscosity information indicating the viscosity of the ink present in the respective regions S1 to S5. Table. The sub tank viscosity table 124 represents the viscosity distribution of ink in the height direction in the sub tank 6 (hereinafter, sub tank viscosity distribution). At the time of attachment when the main tank 30 is attached to the tank attachment unit 5, viscosity information indicating an initial viscosity of "4.0 cps" is associated and stored in each of the regions M1 to M5 and S1 to S6. Be done.

  The CPU 101 acquires the main tank viscosity distribution and the sub tank viscosity distribution by executing an update process for updating the main tank viscosity table 123 and the sub tank viscosity table 124 in each viscosity estimation process. In the present embodiment, in each of the viscosity estimation processes, the CPU 101 performs two update processes of the main tank viscosity table 123 and the sub tank viscosity table 124, the update process related to settling of the pigment, and the update process related to the flow of ink. Divided into two. Hereinafter, the update process regarding sedimentation of a pigment is demonstrated first.

  The ink is supplied from the outlet 66 from the time of mounting at which the main tank 30 is mounted to the tank mounting portion 5 and the time of the viscosity estimation process last time (hereinafter referred to as a reference time) to the current time. When the ink does not flow out, almost no ink flow occurs in the main tank 30 and the sub tank 6. Therefore, between the reference time point and the current time point, the ink present in each of the regions M1 to M5 and S1 to S5 changes its viscosity mainly due to the sedimentation of the pigment.

  For example, in the main tank 30, among the regions M1 to M5, the viscosity of the ink present in the regions M1 and M2 at the lower position is increased by the increase of the pigment. On the other hand, among the regions M1 to M5, the viscosity of the ink present in the regions M4 and M5 located at the high position decreases due to the decrease of the pigment. Similarly, in the subtank 6, while the viscosity of the ink present in the regions S1 and S2 increases, the viscosity of the ink present in the regions S4 and S5 decreases. However, as described above, the sub tank 6 has a smaller amount of sedimentation of the pigment per unit time as compared to the main tank 30. For this reason, the viscosity change amount of the ink present in each of the regions S1 to S5 of the sub tank 6 is smaller than the viscosity change amount of the ink present in the regions M1 to M5 of the main tank 30. Therefore, the difference between the viscosity of the ink present in the region S1 of the sub tank 6 and the viscosity of the ink present in the region S5 is the viscosity of the ink present in the region M1 of the main tank 30 and the ink present in the region M5. Less than the difference between

  In each of the viscosity estimation processes, the CPU 101 estimates the viscosity change amount of the ink present in each of the regions M1 to M5 and S1 to S5 due to the sedimentation of the pigment from the reference time point to the current time point. Then, the CPU 101 performs an update process of adding the estimated viscosity change amount to the viscosity indicated by the viscosity information associated with each of the areas M1 to M5 and S1 to S5 of the main tank viscosity table 123 and the sub tank viscosity table 124. . In addition, since the sedimentation of the pigment is promoted as the temperature is higher as described above, the estimation of the viscosity change amount is also performed with reference to the temperature information measured by the temperature sensor 160 from the reference time point.

  Next, update processing regarding the flow of ink in the main tank viscosity table 123 and the sub tank viscosity table 124 will be described. In this embodiment, in each of the viscosity estimation processes, the update process related to the ink flow is performed after the update process related to the sedimentation of the pigment. In the present embodiment, the period from the reference time to the current time is one month, and the outflow amount of the ink which has flowed out from the outlet 66 from this reference time to the current time is the outflow amount for one month It is. Hereinafter, the outflow during this one month will be referred to as monthly outflow.

  When the ink flows out from the outlet 66 from the reference time to the current time, a flow of ink occurs in the main tank 30 and the sub tank 6. Due to the flow of the ink, the ink present in each of the regions M1 to M5 and S1 to S5 at the reference time is determined in accordance with the amount of the ink flowing out from the outlet 66 from the reference time to the current time. It moves to other areas M1 to M5 and S1 to S5 at a rate. That is, the ink present in any of the regions M1 to M5 and S1 to S5 at the present time is an ink in which the inks present in the regions M1 to M5 and S1 to S5 at the reference time are mixed at a predetermined mixing ratio . Thus, when the ink flow occurs, the viscosity of the ink present in each of the regions M1 to M5 and S1 to S5 is mixed with the ink present in the other regions M1 to M5 and S1 to S5. Change.

  Here, the relationship between the monthly outflow amount and the flow of ink generated in the main tank 30 and the sub tank 6 can be obtained by experiment, simulation or the like. Therefore, based on the relationship between the monthly flow rate and the flow of ink, the ink present in any area M1 to M5, S1 to S5 at the current time is within the area M1 to M5, S1 to S5 at the reference time, respectively. It is also possible to determine the mixing ratio of the ink present in. However, if the total outflow amount of the ink having flowed out from the outlet 66 until the present time is different, the remaining amount of ink in the main tank 30 changes, and as a result, the main tank in each of the areas M1 to M5 and S1 to S5 The height position and the area width in the height direction in each of 30 and in the sub tank 6 are changed. Therefore, in order to accurately determine the mixing ratio, it is necessary to obtain not only the monthly outflow but also the total outflow.

  So, in this embodiment, as shown in FIG. 2, the total outflow amount count information 121 and the previous outflow amount count information 122 are stored in the non-volatile memory 104.

  The total outflow amount count information 121 is count information indicating the total outflow amount of the ink which has flowed out from the outlet 66 from the mounting point. Every time the ink is discharged from the outlet 66 by executing the printing process, the discharging process, and the like, the CPU 101 calculates the amount of the ink and adds it to the count value of the total outflow amount count information 121. The discharge amount of the ink discharged from the nozzle 46 at the time of print processing and flushing can be calculated based on the drive condition of the actuator 45. Further, at the time of suction purge, the discharge amount of the ink discharged from the nozzle 46 can be calculated from drive conditions such as the rotation speed and rotation time of the suction pump 51. Therefore, it is possible to calculate the outflow amount of the ink which has flowed out from the outlet 66.

  The previous outflow amount count information 122 is information indicating the count value of the total outflow amount count information 121 at the reference time point. Therefore, the CPU 101 can acquire the total outflow amount from the current count value of the total outflow amount count information 121 in each viscosity estimation process. Also, if the count value of the previous outflow amount count information 122 is subtracted from the current count value of the total outflow amount count information 121, the monthly outflow amount can be obtained.

  The viscosity estimation program 102a stored in the ROM 102 causes the CPU 101 to calculate the mixing ratio with respect to the ink present in each of the regions M1 to M5 and S1 to S5 based on the monthly outflow amount and the total outflow amount. It contains a program to calculate the mixing ratio. The CPU 101 obtains monthly outflow and total outflow in each of the viscosity estimation processes. Then, the CPU 101 executes the mixing ratio calculation program, and based on the acquired monthly outflow amount and total outflow amount, the above-mentioned mixing ratio regarding the ink present in each of the regions M1 to M5 and S1 to S5 at the current time point Calculate

  Hereinafter, an example of the calculation result of the mixing ratio regarding the ink present in each of the regions M1 to M5 and S1 to S5 will be described with reference to FIGS. 6 (c) and 6 (d). 6C and 6D respectively show the areas M1 to M5, S1 to S5 at the time of installation of the ink present in the areas M1 to M5 and S1 to S5 when one month has elapsed from the time of installation. It shows the mixing ratio of each of the inks present inside. However, FIG. 6 (c) is an amount corresponding to the approximate outflow when the monthly outflow is 100 sheets per month (hereinafter referred to as "PV"). On the other hand, FIG. 6D shows an amount corresponding to the estimated outflow when the monthly outflow is 500 PVs.

  As can be seen from FIGS. 6B and 6C, each of the areas M1 to M5, S1 at the time of installation of the ink present in each of the areas M1 to M5, S1 to S5 when one month has elapsed from the time of installation. The mixing ratio of each of the inks present in ~ S5 differs depending on the monthly outflow. For example, when the monthly outflow amount of the ink existing in the area M1 at the time when one month has passed from the mounting time is equivalent to 100 PV, the mixing ratio of the ink existing in the area M2 at the mounting time is 60%, the mixing ratio of the ink present in the area M3 is 35%, the mixing ratio of the ink present in the area M4 is 5%, and the mixing ratio of the ink present in the other areas is 0%. On the other hand, when the monthly outflow is equivalent to 500 PV sheets, the mixing ratio of the ink present in the area M2 is 40%, the mixing ratio of the ink present in the area M3 is 35%, and the area at the mounting time The mixing ratio of the ink present in M4 is 25%, and the mixing ratio of the ink present in the other area is 0%.

  The CPU 101 uses the viscosity information associated with the areas M1 to M5 and S1 to S5 of the main tank viscosity table 123 and the sub tank viscosity table 124 based on the calculated mixing ratios for the respective areas M1 to M5 and S1 to S5. Update. Specifically, with regard to viscosity information associated with any of the regions M1 to M5 and S1 to S5, the viscosity information associated with each of the regions M1 to M5 and S1 to S5 before the update is set to the arbitrary region. It calculates | requires by proportionally allocating based on the mixing ratio regarding M1-M5 and S1-S5. For example, the viscosities of the viscosity information associated with the respective regions M1 to M5 and S1 to S5 before update are the values shown in FIG. 6A and FIG. 6B, and the mixing ratio is as shown in FIG. In the case of the indicated value, the viscosity of the viscosity information associated with the region M1 is updated to 4.71 cps (= 5.2 × 0.60 + 4.0 × 0.35 + 3.8 × 0.05).

  As described above, in each of the viscosity estimation processing, the main tank viscosity table 123 and the sub tank viscosity table 124 are subjected to the update processing for the sedimentation of the pigment and the update processing for the flow of the ink twice. It is possible to improve the accuracy of the main tank viscosity distribution and the sub tank viscosity distribution indicated by the tank viscosity table 123 and the sub tank viscosity table 124 respectively.

  The CPU 101 estimates the viscosity of the ink flowing out from the outlet 66 based on the main tank viscosity table 123 and the sub tank viscosity table 124 updated by the above update processing. The details will be described below.

  Here, with regard to the ink flowing out from the outlet 66 from the reference time point to the current time point, the ink present in each of the regions M1 to M5 and S1 to S5 at the reference time point is mixed with the ink mixed at a predetermined mixing ratio is there. However, the inventor of the present application has found that the ink flowing out from the outlet 66 is not the ink in which the ink present in all the regions M1 to M5, S1 to S5 at the reference time is mixed, but a part of the regions M1 to M5, S1. It was found that only the ink present in ~ S5 was a mixed ink. That is, the viscosity of the ink discharged from the outlet 66 is the ink existing at a predetermined height (hereinafter, first height H1) or less in the main tank 30 at the reference time, and the predetermined height in the sub tank 6 It has been found that the ink is affected by the ink existing below the second height H2. In other words, the viscosity of the ink discharged from the outlet 66 is the ink present in the area above the first height H 1 in the main tank 30 and the area above the second height of the sub tank 6. It has been found that the ink is hardly affected by the existing ink. In addition, it has been found that the first height H1 and the second height H2 change according to the monthly outflow. That is, the monthly discharge amount changes the height range of the ink present in the main tank 30 and the height range of the ink present in the subtank 6 that affect the viscosity of the ink discharged from the outlet 66. Found out.

  For example, as shown in FIG. 4, when the monthly outflow is an outflow corresponding to 100 PVs, the first height H1 is lower than the partition plate 32 in the main tank 30, and of the supply port 33. The second height H2 is lower than the inlet 64 of the sub tank 6 and higher than the shielding portion 69c of the float mechanism 69. Therefore, when the reference time point is the mounting time point, the viscosity of the ink flowing out from the outlet 66 is influenced by the ink in the areas M1, S1, and S2, as shown in FIG. 4A. Further, when the reference time point is a time point when the ink remaining amount in the main tank 30 is half, the viscosity of the ink flowing out from the outflow port 66 is, as shown in FIG. 4B, regions M1, M2, S1, S2. , S3 will be affected.

  Further, as shown in FIG. 5, when the monthly outflow is equivalent to 500 PVs, the first height H1 is at the height position above the partition plate 32 in the main tank 30, and the second height H1 The height H2 is a height position at which the monthly outflow is slightly higher than the outflow corresponding to 500 PVs. Therefore, for example, when the reference time point is the mounting time point, the viscosity of the ink flowing out from the outlet 66 is affected by the ink in the regions M1, M2, S1, S2, as shown in FIG. 5A. It will be. Further, when the reference time point is a time point when the ink remaining amount in the main tank 30 is half, the viscosity of the ink flowing out from the outflow port 66 is, as shown in FIG. 5B, regions M1 to M4, S1 to S3. It will be affected by the ink inside.

  So, in this embodiment, CPU101 performs adjustment processing which adjusts the 1st height H1 and the 2nd height H2 based on the acquired monthly outflow amount in each viscosity estimation processing. Specifically, the height of each of the first height H1 and the second height H2 is increased as the acquired monthly outflow amount increases. However, as described above, the horizontal cross-sectional area of each height of the upper storage chamber 62 a of the sub tank 6 is smaller than the horizontal cross-sectional area of the main tank 30 at a position higher than the partition plate 32. In addition, the liquid level of the ink in the sub tank 6 and the liquid level of the ink in the main tank 30 are configured to be maintained at the same height. For this reason, the mixing ratio of the ink flowing out of the outlet 66 from the reference time point to the current time point, which is present in the upper storage chamber 62a of the sub tank 6 at the reference time point, is extremely small. Therefore, in the present embodiment, in order to simplify the estimation of the viscosity, the upper limit of the second height H2 is set in the lower storage chamber 61a, and is configured to be lower than the upper storage chamber 62a. There is. The first height H1 and the second height H2 adjusted by the adjustment process are stored as height information 126 in the non-volatile memory 104.

  Then, based on the first height H1 and the second height H2 of the height information 126 stored in the non-volatile memory 104, the CPU 101 determines the viscosity associated with each of the areas M1 to M5 of the main tank viscosity table 123. Among the information, the viscosity information associated with the regions M1 to M5 having the first height H1 or less and the viscosity information associated with the regions S1 to S5 of the sub tank viscosity table 124, the second height H2 Only viscosity information corresponding to the following regions is extracted. The main tank viscosity table 123 and the sub tank viscosity table 124, which are targets for extracting the viscosity information, are after the update process for pigment ink is completed in the viscosity estimation process and before the update process for ink flow is performed. Table.

  The CPU 101 estimates the viscosity of the ink flowing out of the outlet 66 based on the extracted viscosity information. At the time of this estimation, the mixing ratio of the ink flowing out from the outlet 66 and present in each of the regions M1 to M5 and S1 to S5 at the reference time is calculated. Then, based on the calculated mixing ratio, the viscosity value of the extracted viscosity information is proportionally distributed to estimate the viscosity of the ink flowing out from the outlet 66.

  The mixing ratio of the ink flowing out from the outlet 66 can also be determined if the monthly supply amount and the total supply amount are obtained as in the case of the mixing ratio of the ink in the regions M1 to M5 and S1 to S5. Can. Therefore, the mixing ratio calculation program included in the viscosity estimation program 102 a can also cause the CPU 101 to calculate the mixing ratio regarding the ink flowing out from the outlet 66. Then, the CPU 101 executes the mixing ratio calculation program to calculate the mixing ratio regarding the ink flowing out from the outlet 66 based on the acquired monthly outflow amount and the total outflow amount.

  FIG. 6E shows an example of the calculation result of the mixing ratio of the ink discharged from the outlet 66. In FIG. 6E, the monthly outflow is equivalent to 100 PV sheets and 500 PV sheets when the reference time point is when the mounting time and when the remaining amount of ink in the main tank 30 is half, respectively. The mixing ratio of the ink which flowed out from the outlet 66 at one time and was present in each of the regions M1 to M5 and S1 to S5 at the reference time is illustrated. For example, when the reference time point is when the remaining amount of ink in the main tank 30 is half and the monthly outflow amount is the outflow amount corresponding to 100 PVs, the ink which flows out from the outlet 66 is an area at the attachment time point The mixing ratio of the ink present in M1 is 3%, the mixing ratio of the ink present in area M2 is 2%, the mixing ratio of the ink present in area S1 is 70%, and the ink mixing present in area S2 The ratio is 20%, the mixing ratio of the ink present in the area S3 is 5%, and the mixing ratio of the ink present in the other areas is 0%.

  The CPU 101 calculates the mixing ratio of the ink flowing out from the outlet 66 calculated in this manner, and the viscosity extracted from the main tank viscosity table 123 and the sub tank viscosity table 124 according to the first height H1 and the second height H2. Based on the information, the viscosity of the ink flowing out of the outlet 66 is estimated. For example, in the case where the reference time point is a time point when the remaining amount of ink in the main tank 30 is half and the monthly outflow amount is an outflow amount corresponding to 100 PV sheets, each area M1 to M1 after the update process for the pigment is performed When the viscosity values of M5 and S1 to S5 are the values shown in FIG. 6A and FIG. 6B, the viscosity of the ink discharged from the outlet 66 is 4.36 cps (= 6.0 × 0. 6). It is estimated that (03 + 5.2 x 0.02 + 4.4 x 0.70 + 4.2 x 0.20 + 4.0 x 0.05).

  Next, a series of processing operations of the printer 1 related to the viscosity estimation processing will be described with reference to FIG.

  First, the CPU 101 determines whether one month has passed since the reference time (A1). When it is determined that one month has passed (A1: YES), the CPU 101 refers to the total outflow amount count information 121 and the previous outflow amount count information 122 of the non-volatile memory 104, and outputs the monthly outflow amount, , To obtain the total outflow (A2). Next, the CPU 101 estimates the viscosity change amount of the ink present in each of the regions M1 to M5 and S1 to S5 based on the sedimentation of the pigment with the passage of time from the reference time point to the current time point, and based on the estimation result Then, the main tank viscosity table 123 and the sub tank viscosity table 124 are updated (A3).

  Next, the CPU 101 calculates the mixing ratio of the ink flowing out from the outlet 66 based on the monthly outflow amount and the total outflow amount acquired in the process of A2 (A4). Next, the CPU 101 adjusts the first height H1 and the second height H2 based on the monthly outflow obtained in the process of A2, and stores the first height H1 and the second height H2 in the non-volatile memory 104 as height information 126 (A5). Thereafter, the CPU 101 controls the viscosity information associated with the area of the first height H1 or less indicated by the height information 126 among the areas M1 to M5 of the main tank viscosity table 123, the areas S1 to S5 of the sub tank viscosity table 124. Among them, the viscosity information associated with the area of the second height H2 or less indicated by the height information 126 is extracted respectively, proportionally distributed based on the mixing ratio acquired by the processing of A4, and the outflow from the outlet 66 The viscosity of the ink is estimated (A6).

  After that, the CPU 101 associates the estimated viscosity with the count value of the total outflow amount count information 121, and stores it in the outlet viscosity table 125 of the non-volatile memory 104 (A7). The outlet viscosity table 125 is a table in which the estimated viscosity is associated with the count value of the total outflow amount count information 121 at the time of the estimation. Next, the CPU 101 calculates the mixing ratio of the ink present in each of the areas M1 to M5 and S1 to S5 based on the monthly outflow and the total outflow acquired in the process of A2, and based on the mixing ratio. An update process (update process regarding the flow of ink) for updating the main tank viscosity table 123 and the sub tank viscosity table 124 is executed (A8). When the process of A8 ends, the process returns to the process of A1.

  Next, an example of the processing operation of the printer 1 will be described with reference to FIG. In the following description, an aspect in which the actuator 45 performs flushing as a discharge process after receiving a print command and before performing a print process will be described. However, the present invention is not particularly limited thereto. The apparatus 9 may be configured to perform suction and purge.

  First, the CPU 101 determines whether a print command has been received from the external device 200 (S1). If it is determined that the print command has been received (S1: YES), the CPU 101 uses the ink in the nozzle 46 based on the current total outflow amount indicated by the outflow viscosity table 125 and the total outflow amount count information 121. Estimate the viscosity of (S2). Specifically, from the count value indicated by the total outflow amount count information 121, the subtraction amount is calculated by subtracting the count value corresponding to the flow path volume of the ink flow path from the outlet 66 to the nozzle 46. Then, the viscosity (outflow viscosity) associated with the count value closest to the subtraction amount in the outlet viscosity table 125 is estimated to be the current viscosity in the nozzle 46. The amount of viscosity increase due to drying in the ink flow path from the outlet 66 to the nozzle 46 is also estimated, and the viscosity obtained by adding the amount of viscosity increase to the outflow viscosity is the viscosity of the ink in the nozzle 46 It may be estimated that

  Next, the CPU 101 determines the driving condition (flushing condition) of the actuator 45 at the time of performing the flushing according to the estimated viscosity of the ink in the nozzle 46 (S3). Then, the CPU 101 executes a flushing process for causing the actuator 45 to perform flushing in accordance with the determined flushing condition (S4). Thereafter, the CPU 101 controls the carriage drive motor 20, the head 4 and the like to execute a printing process for printing an image on the sheet P in accordance with the printing instruction received from the external device 200 (S5). Next, the CPU 101 calculates and calculates the consumption amount of the ink ejected or discharged from the nozzle 46 after the printing instruction is received in the process of S1 until the printing process related to the printing instruction is completed. The consumed amount is added to the count value of the total outflow amount count information 121 as the outflow amount of the ink having flowed out from the outlet 66 (S6).

  Next, based on the output result of the remaining amount detection sensor 120, the CPU 101 determines whether or not the liquid level of the ink in the sub tank 6 is less than the detection position (S7). If it is determined that the state is not near empty (S7: NO), the process returns to S1. On the other hand, when it is determined that the near empty state (S7: YES), the CPU 101 displays on the touch panel 161 a replacement screen prompting replacement of the main tank 30 (S8). Thereafter, based on the detection result of the mounting detection sensor 130, when it is determined that the main tank 30 has been replaced by the user and the new main tank 30 has been mounted to the tank mounting portion 5 (S9: YES), The CPU 101 initializes the total outflow amount count information 121, the previous outflow amount count information 122, the main tank viscosity table 123, the sub tank viscosity table 124, the outflow port viscosity table 125, etc. stored in the nonvolatile memory 104 (S10), It returns to the process of S1.

  As described above, according to the present embodiment, the viscosity information associated with the area of the first height H1 or less among the areas M1 to M5 of the main tank viscosity table 123 and the areas S1 to S5 of the sub tank viscosity table 124 The estimation accuracy can be enhanced by estimating the viscosity of the ink flowing out from the outlet 66 based on the viscosity information associated with the area of the second height H2 or less.

  Further, viscosity information associated with the area having the first height H1 or less among the areas M1 to M5, and viscosity information associated with the area having the second height H2 or less among the areas S1 to S5 In order to estimate viscosity based on it, viscosity estimation can be easily performed compared with the case where viscosity is estimated using all the viscosity information matched with field M1-M5 and S1-S5. For example, in the present embodiment, when extracting viscosity information from the main tank viscosity table 123 and the sub tank viscosity table 124, of the regions M1 to M5, only the viscosity information associated with the region equal to or less than the first height H1. Since only the viscosity information associated with the area having the second height H2 or less is extracted out of the areas S1 to S5, it is compared with the case where the viscosities of all the areas M1 to M5 and S1 to S5 are extracted. Thus, the processing load required for the extraction can be reduced.

  In the embodiment described above, the main tank 30 corresponds to the "first tank", and the sub tank 6 corresponds to the "second tank". The tank mounting unit 5 corresponds to the "mounting unit". The main tank viscosity distribution represented by the main tank viscosity table 123 corresponds to the “first viscosity distribution”. The subtank viscosity distribution represented by the subtank viscosity table 124 corresponds to the “second viscosity distribution”. The atmosphere communication port 35 corresponds to the "first atmosphere communication port", and the atmosphere communication port 63 corresponds to the "second atmosphere communication port". The lower storage chamber 61a corresponds to a "first storage chamber", and the upper storage chamber 62a corresponds to a "second storage chamber". The shielding part 69 c corresponds to the “detected part”.

  As mentioned above, although the preferred embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made within the scope of the claims. For example, although the main tank viscosity distribution is viscosity information associated with five regions obtained by evenly dividing the region below the liquid surface of the ink in the main tank 30 into five in the height direction, The viscosity information is not limited to the above, and it may be viscosity information associated with each region equally divided into N (N is a natural number satisfying N> 1) regions below the liquid surface of the ink. Similarly, with regard to the sub-tank viscosity distribution, viscosity information associated with each region equally divided into M (M is a natural number satisfying M> 1) or less regions of the ink surface or less in the sub-tank 6 I hope there is. Further, as in the above-described embodiment, when the N and the M are equal to each other, the main tank viscosity table 123 and the sub tank viscosity table 124 can be made to have the same table structure. There are cases where it is possible to simplify the calculation process referring to. Meanwhile, the N and the M may be different from each other. For example, the main tank 30 has a large sedimentation amount of pigment per unit time as compared to the sub tank 6, and the viscosity difference between the lower and upper portions of the ink stored in the main tank 30 is large. With regard to the distribution, the N may be larger than M in order to further subdivide.

  Further, the shapes of the main tank 30 and the sub tank 6 and the shapes of the flow paths in the respective chambers are not limited to the aspect of the above embodiment. For example, the sub tank may have a rectangular parallelepiped shape as a whole. In this case, if the horizontal cross-sectional area of each height in the sub-tank is different from the bottom area in the main tank or the horizontal cross-sectional area of each height, the sub-tank has a smaller amount of sedimentation of the pigment settling to the bottom compared to the main tank. As in the above-described embodiment, the sub-tank viscosity distribution is a distribution different from the main tank viscosity distribution.

  In addition, in the update processing regarding sedimentation of the pigment in the main tank viscosity table 123 and the sub tank viscosity table 124, the amount of viscosity change due to sedimentation of the pigment from the reference time point to the current time point is estimated. Absent. For example, the amount of viscosity change due to sedimentation of the pigment from the reference time to an intermediate time between the reference time and the current time may be estimated. That is, it may be configured to estimate the average viscosity of the ink present in each of the regions M1 to M5 and S1 to S5 within a predetermined period from the reference time point to the current time point. Further, the viscosity of the ink discharged from the outlet 66 estimated by the viscosity estimation processing does not have to be the viscosity of the ink at the current point in time, and may be an average viscosity from the reference time to the current point.

  Further, the main tank viscosity distribution and the sub tank viscosity distribution may not be estimated and acquired by the CPU 101 but may be estimated by the external device 200 and the CPU 101 may acquire the estimation result. Regarding the mixing ratio of the ink flowing out from the outlet 66, the mixing ratio of the ink present in each of the regions M1 to M5 and S1 to S5, but the ink existing in the sub tank 6 at the reference time, the inside of the main tank 30 It may be a mixing ratio of each of the inks present in.

  The viscosity estimation program 102a described above is stored in the ROM 102 of the control device 100. However, the present invention is not particularly limited to this, and the viscosity estimation program 102a may be stored in a storage medium such as the USB memory 250. In this case, the estimation device for estimating the viscosity of the ink flowing out from the outlet 66 of the control device 100 of the printer 1 or the external device 200 installs the viscosity estimation program stored in the storage medium such as the USB memory 250. Thus, the above-described viscosity estimation process is performed. Further, the viscosity estimation program may be incorporated in a printer driver, and a PC installed with the printer driver may be configured to execute viscosity estimation processing.

  The external device 200 may be configured to execute the viscosity estimation process when simulating the predicted transition of the viscosity of the ink flowing out from the outlet 66. For example, in the case of generating viscosity transition data regarding predicted transition of the viscosity of the ink flowing out from the outlet 66 when the outflow amount per unit time of the ink flowing out from the outlet 66 is a fixed amount, An estimation process may be performed. In this case, the first height H1 and the second height H2 have fixed values. Note that if a plurality of such forecasted transition data are generated by changing the fixed amount and stored in the printer 1, for example, the CPU 101 acquires the outflow amount per unit time that has flowed out from the outflow port 66, It is also possible to estimate the actual viscosity of the ink that has flowed out of the outlet 66 by performing calculations such as interpolation based on the plurality of pieces of predicted transition data and the acquired flow rate per unit time.

  The ink discharge operation performed by the purge device 9 is a suction purge that applies a suction force to the nozzle 46. For example, a pressure pump is provided in the middle of the supply tube 22, and this pressure pump is driven. Alternatively, the ink may be supplied to the head 4 to discharge the ink from the nozzle 46. Also, the purge device may be capable of performing both of the suction purge and the pressure purge.

  In addition, the tank mounting unit to which the main tank is mounted may be configured to be able to accommodate the sub tank as well. That is, the sub tank may be provided in the tank mounting portion.

  The present invention can also be applied to a so-called line-type inkjet printer that prints an image on a sheet transported by the transport mechanism with the inkjet head fixed.

1 Ink jet printer (ink jet recording device)
4 Ink jet head 5 Tank mounting part (mounting part)
6 Sub tank (second tank)
30 Main tank (first tank)
101 CPU (control unit)

Claims (18)

A first tank for storing pigment ink, and a mounting unit to which the first tank having a supply port at the lower part is mounted;
A second tank having an inlet communicating with the supply port of the first tank, and an outlet located below the inlet;
An inkjet head connected to the outlet;
And a control unit,
The control unit
A first viscosity distribution, which is a viscosity distribution of pigment ink in the height direction in the first tank mounted to the mounting portion, and a second viscosity, which is the viscosity distribution of the pigment ink in the height direction in the second tank Get each distribution,
From the outlet based on the acquired viscosity information of the first tank or less in the first viscosity distribution and the viscosity information of the second tank or less in the second viscosity distribution An ink jet recording apparatus characterized in that the viscosity of a pigment ink to be discharged is estimated. The first tank has a first atmosphere communication port for communicating the inside of the first tank with the atmosphere,
The second tank is
The first storage room,
A second storage chamber extending upward from the first storage chamber and having a horizontal cross-sectional area smaller than a horizontal cross-sectional area of the first storage chamber;
A second atmosphere communication port for communicating the second storage chamber with the atmosphere;
Have
The inlet and the outlet are formed in the first storage chamber,
The horizontal cross-sectional area of the second storage chamber is smaller than the horizontal cross-sectional area of the first tank at a position higher than the first storage chamber,
The inkjet recording apparatus according to claim 1, wherein the second height is lower than the second storage chamber. A to-be-detected portion which is accommodated in the first storage chamber and displaced in the vertical direction according to the displacement of the liquid surface of the pigment ink in the first storage chamber in the vertical direction;
And a sensor for outputting information on the liquid level of the pigment ink in the first storage chamber based on the detected portion.
The inkjet recording apparatus according to claim 2, wherein the second height is located above the detection target. The first tank has a first atmosphere communication port for communicating the inside of the first tank with the atmosphere,
2. The ink jet recording apparatus according to claim 1, wherein the second tank has a second atmosphere communication port for communicating the inside of the second tank with the atmosphere. The control unit
As the first viscosity distribution, viscosity information for each of N regions obtained by evenly dividing the region below the liquid surface of the pigment ink in the first tank into N (N> 1) in the height direction is obtained. ,
As the second viscosity distribution, viscosity information for each of M regions obtained by evenly dividing the region below the liquid surface of the pigment ink in the second tank into M (M> 1) in the height direction is obtained. Yes,
When estimating the viscosity of the pigment ink discharged from the outlet,
Among the N pieces of viscosity information as the first viscosity distribution, viscosity information corresponding to a region at the first height or less and the second high value of the M pieces of viscosity information as the second viscosity distribution The viscosity of the pigment ink flowing out of the outlet is estimated based on the viscosity information corresponding to the region below
further,
The viscosity information for each of the N regions is obtained as the first viscosity distribution regardless of the remaining amount of pigment ink in each of the first tank and the second tank, and the M regions are obtained as the second viscosity distribution. The ink jet recording apparatus according to any one of claims 1 to 4, wherein viscosity information for each of the plurality of ink jet recording apparatuses is acquired.   The inkjet recording apparatus according to claim 5, wherein the N and the M are equal. The control unit
A mixture of the pigment ink that was present in the first tank at the start of the predetermined period, and the pigment ink that was present in the second tank at the start of the predetermined period, of the pigment ink that flows out from the outlet within the predetermined period Get the percentage further, and
Acquiring the first viscosity distribution and the second viscosity distribution with respect to the predetermined period;
Regarding the predetermined period, based on the acquired viscosity information of the first viscosity distribution at the first height or less, the viscosity information of the second viscosity distribution or less at the second viscosity distribution, and the acquired mixing ratio The ink jet recording apparatus according to any one of claims 1 to 6, wherein the viscosity of the pigment ink discharged from the outlet is estimated. A first tank for storing pigment ink, and a mounting portion to which a first tank having a supply port is mounted at a lower portion, an inlet communicating with the supply port of the first tank, and a lower side than the inlet A viscosity estimation method for estimating the viscosity of pigment ink flowing out from the outlet, in an ink jet recording apparatus having a second tank having the arranged outlet and an inkjet head connected to the outlet.
A first viscosity distribution, which is a viscosity distribution of pigment ink in the height direction in the first tank mounted to the mounting portion, and a second viscosity, which is the viscosity distribution of the pigment ink in the height direction in the second tank Viscosity distribution acquisition step for acquiring each distribution;
According to the viscosity information acquired in the viscosity distribution acquisition step, the viscosity information of the first viscosity distribution and below the first height in the first viscosity distribution, and the viscosity information and below of the second height of the second tank in the second viscosity distribution A viscosity estimation step of estimating the viscosity of the pigment ink discharged from the outlet based on
A viscosity estimation method characterized by including. An outflow amount acquiring step of acquiring an outflow amount of pigment ink flowing out from the outlet during a predetermined period;
An adjustment step of adjusting the first height and the second height based on the outflow amount acquired by the outflow amount acquisition step;
The viscosity estimation method according to claim 8, further comprising   The viscosity estimation method according to claim 8, wherein a horizontal cross-sectional area of the second tank is smaller than a bottom area of the first tank.   The viscosity estimation method according to any one of claims 8 to 10, wherein a volume of the second tank is smaller than a volume of the first tank. The second tank is
The first storage room,
A second storage chamber extending upward from the first storage chamber and having a horizontal cross-sectional area smaller than a horizontal cross-sectional area of the first storage chamber;
The viscosity estimation method according to any one of claims 8 to 11, characterized in that   The viscosity estimation method according to claim 12, wherein the inlet and the outlet are formed in the first storage chamber. The inkjet recording apparatus is
A to-be-detected portion which is accommodated in the first storage chamber and displaced in the vertical direction according to the displacement of the liquid surface of the pigment ink in the first storage chamber in the vertical direction;
The viscosity estimation method according to claim 12, further comprising: a sensor that outputs information related to the liquid level of the pigment ink in the first storage chamber based on the detection target.   The viscosity estimation method according to any one of claims 8 to 14, wherein the first tank and the second tank are arranged side by side in the horizontal direction. The first tank has a first atmosphere communication port for communicating the inside of the first tank with the atmosphere,
The viscosity estimation method according to any one of claims 8 to 15, wherein the second tank has a second atmosphere communication port for communicating the inside of the second tank with the atmosphere. A mixture of the pigment ink that was present in the first tank at the start of the predetermined period, and the pigment ink that was present in the second tank at the start of the predetermined period, of the pigment ink that flows out from the outlet within the predetermined period Further including a mixing ratio acquisition step of acquiring the ratio;
In the viscosity distribution acquisition step, each of the first viscosity distribution and the second viscosity distribution regarding the predetermined period is acquired,
In the viscosity estimation step, viscosity information of the first viscosity distribution or less obtained in the viscosity distribution acquisition step, and viscosity information of the second viscosity distribution or less in the second viscosity distribution, The viscosity of the pigment ink which flows out from the said outflow port regarding the said predetermined period is estimated based on the said mixing ratio acquired by the said mixing ratio acquisition step, The any one of the Claims 8-16 characterized by the above-mentioned. The viscosity estimation method described in. A first tank for storing pigment ink, the mounting portion being mounted with a first tank having a supply port at a lower portion, an inlet communicating with the supply port of the first tank, and a lower side than the inlet And an ink jet recording apparatus having an ink jet head connected to the outlet, and a program executed by the estimation apparatus for estimating the viscosity of pigment ink discharged from the outlet. A storage medium for storing
The program causes the estimation device to
A first viscosity distribution, which is a viscosity distribution of pigment ink in the height direction in the first tank mounted to the mounting portion, and a second viscosity, which is the viscosity distribution of the pigment ink in the height direction in the second tank Viscosity distribution acquisition processing for acquiring each distribution;
According to the viscosity information acquired by the viscosity distribution acquisition process, the viscosity information of the first tank in the first viscosity distribution that is equal to or less than the first height of the first tank, and the viscosity information of the second tank that is equal to or less than the second height in the second viscosity distribution Viscosity estimation processing for estimating the viscosity of the pigment ink discharged from the outlet based on the
A storage medium characterized by performing.

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