JP2024122132A - LIQUID SUPPLY SYSTEM, CONTROL METHOD, CONTROL PROGRAM, AND LIQUID SUPPLY APPARATUS - Google Patents

Abstract

[Problem] To provide a liquid supply system, a control method, a control program, and a liquid supply device that contribute to bringing the actual remaining amount of liquid in a tank after circulation closer to the actual remaining amount of liquid in the tank before circulation. [Solution] The liquid supply system includes a pipe connecting a printer tank and a server tank, a liquid delivery mechanism that delivers liquid between the printer tank and the server tank via the pipe, and a control unit. The control unit obtains the remaining amount from a remaining amount sensor that detects the remaining amount of liquid in the printer tank or the server tank (S21). The control unit controls the liquid delivery mechanism to deliver liquid from a first tank, either the printer tank or the server tank, to a second tank, either the printer tank or the server tank (S23). The control unit obtains the remaining amount from the remaining amount sensor (S31). The control unit calculates a calculation time based on the remaining amounts obtained in S21 and S31 (S33). The control unit controls the liquid delivery mechanism based on the calculated time to deliver liquid from the second tank to the first tank. [Selected Figure] FIG.

Description

The present invention relates to a liquid supply system, a control method, a control program, and a liquid supply device.

A liquid supply system that supplies liquid to a printer is known. The liquid supply system described in Patent Document 1 includes a main tank and a printer. The main tank contains ink as a type of liquid. The printer includes a sub-tank. The sub-tank is connected to the main tank via a main tank tube. The liquid supply system supplies ink from the main tank to the sub-tank via the main tank tube. The sub-tank is provided with a sub-tank remaining amount sensor for detecting the amount of ink remaining in the sub-tank.

JP 2004-314392 A

In the above liquid supply system, in order to prevent the ink from becoming uneven in temperature distribution, concentration distribution, etc., it is possible to circulate the ink between the main tank and the sub tank via a main tank tube. In this case, due to detection errors of the sub tank remaining amount sensor, etc., the actual amount of ink remaining in the main tank after circulation may change from the actual amount of ink remaining in the main tank before circulation, and the actual amount of ink remaining in the sub tank after circulation may change from the actual amount of ink remaining in the sub tank before circulation. Similarly, when a remaining amount sensor is provided in the main tank, the actual amount of ink remaining in the main tank and the sub tank may change before and after circulation.

The object of the present invention is to provide a liquid supply system, a control method, a control program, and a liquid supply device that contribute to bringing the actual amount of liquid remaining in a tank after circulation closer to the actual amount of liquid remaining in the tank before circulation.

The liquid supply system according to a first aspect of the present invention is a liquid supply system that supplies liquid to a printer tank, which is a tank provided in a printer, and includes a pipe connecting the printer tank and a server tank that contains the liquid, a liquid delivery mechanism that delivers the liquid between the printer tank and the server tank via the pipe, and a control unit, and the control unit performs a first acquisition process to acquire the remaining amount based on a signal from a remaining amount sensor that detects the remaining amount of the liquid in the printer tank or the server tank, and after the first acquisition process has been performed, controls the liquid delivery mechanism to deliver liquid from a first tank, which is one of the printer tank and the server tank. The method is characterized by performing a first liquid delivery process to deliver the liquid through the pipe to a second tank, which is different from the first tank, among the printer tank and the server tank; a second acquisition process to acquire the remaining amount based on a signal from the remaining amount sensor after the first liquid delivery process is performed; a calculation process to calculate a calculation time based on a first remaining amount, which is the remaining amount acquired by the first acquisition process, and a second remaining amount, which is the remaining amount acquired by the second acquisition process; and a second liquid delivery process to control the liquid delivery mechanism based on the calculation time calculated by the calculation process and deliver the liquid from the second tank to the first tank through the pipe.

According to the first aspect, the first liquid transfer process and the second liquid transfer process are performed, and liquid is circulated between the printer tank and the server tank via a pipe. In the second liquid transfer process, the liquid transfer mechanism is controlled based on the calculated time. Thus, the liquid supply system contributes to bringing the actual amount of liquid remaining in the tank after circulation closer to the actual amount of liquid remaining in the tank before circulation, compared to a case in which liquid is transferred from the second tank to the first tank via a pipe not based on the calculated time.

In the second liquid transfer process, the control unit may transfer the liquid from the second tank to the first tank through the pipe, and after the remaining amount indicated by the signal from the remaining amount sensor becomes the first remaining amount, transfer the liquid from the second tank to the first tank through the pipe for an additional time based on the calculated time.

For example, suppose that when the remaining amount indicated by the signal from the remaining amount sensor reaches a first remaining amount, there is a specific difference between the remaining amount indicated by the signal from the remaining amount sensor and the actual remaining amount. In the second liquid transfer process, liquid is transferred from the second tank to the first tank via a tube for an addition time based on the calculation time from the time when the remaining amount indicated by the signal from the remaining amount sensor reaches the first remaining amount. This makes the difference between the actual remaining amount of liquid in the tank after circulation and the remaining amount of liquid in the tank before circulation smaller than the specific amount. Therefore, the liquid supply system further contributes to bringing the actual remaining amount of liquid in the tank after circulation closer to the actual remaining amount of liquid in the tank before circulation.

The control unit may, in the second liquid transfer process, transfer the liquid from the second tank to the first tank through the pipe, and from the time when the remaining amount indicated by the signal from the remaining amount sensor becomes the first remaining amount, transfer the liquid from the second tank to the first tank through the pipe for the added time based on the calculated time without stopping the liquid transfer mechanism.

In this case, the liquid delivery mechanism does not stop when the remaining amount indicated by the signal from the remaining amount sensor reaches the first remaining amount. Therefore, the liquid supply system contributes to preventing the time required for the second liquid delivery process from becoming longer.

The printer tank may include a printer sensor that detects the remaining amount of the liquid in the printer tank, and a server sensor that detects the remaining amount of the liquid in the server tank, and the remaining amount sensor may be the one of the printer sensor and the server sensor that is less susceptible to changes in the external environment.

In this case, the liquid supply system contributes to bringing the actual amount of liquid remaining in the tank after circulation closer to the actual amount of liquid remaining in the tank before circulation, even if the external environment changes.

The control unit may perform the calculation process each time a circulation process including the first liquid delivery process and the second liquid delivery process is performed, and may perform a judgment process to determine whether the circulation process is the first one since the liquid supply system is powered on or the first one since the server tank is replaced. If the judgment process determines that the circulation process is the first one since the liquid supply system is powered on or the first one since the server tank is replaced, in the second liquid delivery process, the control unit may control the liquid delivery mechanism based on the calculated time calculated by the current calculation process to deliver the liquid from the second tank to the first tank via the pipe.

The calculated time for the first circulation process after the liquid supply system is powered on, or the first circulation process after the server tank is replaced, is relatively likely to vary significantly from the calculated time for the previous circulation process. In the liquid supply system, when the calculated time is relatively likely to vary significantly from the previous time, the liquid delivery mechanism is controlled based on the current calculated time. Thus, when the calculated time is relatively likely to vary significantly from the previous time, the liquid supply system contributes to more reliably bringing the actual amount of liquid remaining in the tank after circulation closer to the actual amount of liquid remaining in the tank before circulation.

The control unit may perform the calculation process each time a circulation process including the first liquid delivery process and the second liquid delivery process is performed, and may perform a judgment process to determine whether the circulation process is the first one since the liquid supply system is powered on or the first one since the server tank is replaced. If the judgment process determines that the circulation process is not the first one since the liquid supply system is powered on or if the judgment process determines that the circulation process is not the first one since the server tank is replaced, in the second liquid delivery process, the control unit may control the liquid delivery mechanism based on a specific time based on the calculation time calculated by the previous calculation process to deliver the liquid from the second tank to the first tank via the tube.

The calculated time for the second or subsequent circulation process after the liquid supply system is powered on, or for the second or subsequent circulation process after the server tank is replaced, is relatively unlikely to change significantly from the calculated time for the previous circulation process. In this case, the liquid delivery mechanism is controlled based on the specific time. The specific time is based on the previous calculated time that has already been proven. Thus, when the calculated time is relatively unlikely to change significantly from the previous time, the liquid supply system contributes to more reliably bringing the actual amount of liquid remaining in the tank after circulation closer to the actual amount of liquid remaining in the tank before circulation.

The control unit may perform the calculation process each time a circulation process including the first liquid transfer process and the second liquid transfer process is performed, and perform a judgment process to judge whether a difference between a specific time based on a first calculation time, which is the calculation time calculated by the previous calculation process, and a second calculation time, which is the calculation time calculated by the current calculation process, is equal to or greater than a predetermined value, and if the judgment process judges that the difference is equal to or greater than the predetermined value, in the second liquid transfer process, the liquid transfer mechanism may be controlled based on the second calculation time to transfer the liquid from the second tank to the first tank via the tube.

When the configuration of the pipes is changed, for example, the difference between the specific time and the second calculated time may exceed a predetermined value. In this case, the liquid delivery mechanism is controlled based on the second calculated time according to the current configuration of the pipes, etc. Thus, when the difference between the specific time and the second calculated time is equal to or greater than a predetermined value, the liquid supply system contributes to ensuring that the actual amount of liquid remaining in the tank after circulation is closer to the actual amount of liquid remaining in the tank before circulation.

The control unit may perform the calculation process each time a circulation process including the first liquid transfer process and the second liquid transfer process is performed, and perform a judgment process to judge whether a difference between a specific time based on a first calculation time, which is the calculation time calculated by the previous calculation process, and a second calculation time, which is the calculation time calculated by the current calculation process, is equal to or greater than a predetermined value, and if the judgment process judges that the difference is not equal to or greater than the predetermined value, in the second liquid transfer process, the liquid transfer mechanism may be controlled based on the specific time to transfer the liquid from the second tank to the first tank via the tube.

In cases where the pipe configuration has not been changed, for example, the difference between the specific time and the second calculated time may be less than a predetermined value. In this case, the liquid delivery mechanism is controlled based on the specific time. The specific time is a time that has already been proven to work. Thus, when the difference between the specific time and the second calculated time is equal to or greater than a predetermined value, the liquid supply system contributes to more reliably bringing the actual amount of liquid remaining in the tank after circulation closer to the actual amount of liquid remaining in the tank before circulation.

A control method according to a second aspect of the present invention is a control method by a liquid supply system that supplies liquid to a printer tank, which is a tank provided in a printer, the liquid supply system including a pipe connecting the printer tank and a server tank that contains the liquid, and a liquid delivery mechanism that delivers the liquid between the printer tank and the server tank via the pipe, the control method including a first acquisition process that acquires the remaining amount based on a signal from a remaining amount sensor that detects the remaining amount of the liquid in the printer tank or the server tank, and after the first acquisition process is performed, controlling the liquid delivery mechanism to deliver the remaining amount of the liquid to a first tank that is one of the printer tank and the server tank. The system is characterized by comprising a first liquid delivery process for delivering the liquid from the tank through the pipe to a second tank, different from the first tank, of the printer tank and the server tank; a second acquisition process for acquiring the remaining amount based on a signal from the remaining amount sensor after the first liquid delivery process is performed; a calculation process for calculating a calculation time based on a first remaining amount, which is the remaining amount acquired by the first acquisition process, and a second remaining amount, which is the remaining amount acquired by the second acquisition process; and a second liquid delivery process for controlling the liquid delivery mechanism based on the calculation time calculated by the calculation process, and delivering the liquid from the second tank to the first tank through the pipe.

Like the first aspect, the second aspect contributes to bringing the actual amount of liquid remaining in the tank after circulation closer to the actual amount of liquid remaining in the tank before circulation.

The control program according to a third aspect of the present invention is a control program that causes a computer of a liquid supply system that supplies liquid to a printer tank, which is a tank provided in a printer, to execute the following processes, the liquid supply system comprising a pipe connecting the printer tank and a server tank that contains the liquid, and a liquid delivery mechanism that delivers the liquid between the printer tank and the server tank via the pipe, the control program instructing the computer to carry out a first acquisition process that acquires the remaining amount based on a signal from a remaining amount sensor that detects the remaining amount of the liquid in the printer tank or the server tank, and after the first acquisition process has been carried out, to control the liquid delivery mechanism and deliver the liquid to the printer tank and The method is characterized by executing a first liquid delivery process for delivering the liquid from a first tank, which is one of the server tanks, to a second tank, which is one of the printer tank and the server tank and is different from the first tank, via the pipe; a second acquisition process for acquiring the remaining amount based on a signal from the remaining amount sensor after the first liquid delivery process is performed; a calculation process for calculating a calculation time based on a first remaining amount, which is the remaining amount acquired by the first acquisition process, and a second remaining amount, which is the remaining amount acquired by the second acquisition process; and a second liquid delivery process for controlling the liquid delivery mechanism based on the calculation time calculated by the calculation process and delivering the liquid from the second tank to the first tank via the pipe.

Like the first aspect, the third aspect contributes to bringing the actual amount of liquid remaining in the tank after circulation closer to the actual amount of liquid remaining in the tank before circulation.

The liquid supply device according to a fourth aspect of the present invention is a liquid supply device that supplies liquid to a printer tank, which is a tank provided in a printer, and includes a pipe connecting the printer tank and a server tank that contains the liquid, a liquid delivery mechanism that delivers the liquid between the printer tank and the server tank via the pipe, and a control unit, and the control unit performs a first acquisition process that acquires the remaining amount based on a signal from a remaining amount sensor that detects the remaining amount of the liquid in the printer tank or the server tank, and after the first acquisition process has been performed, controls the liquid delivery mechanism to deliver the previous amount of liquid from a first tank, which is one of the printer tank and the server tank. The method is characterized by performing a first liquid delivery process to deliver the liquid through the pipe to a second tank, which is different from the first tank, among the printer tank and the server tank; a second acquisition process to acquire the remaining amount based on a signal from the remaining amount sensor after the first liquid delivery process is performed; a calculation process to calculate a calculation time based on a first remaining amount, which is the remaining amount acquired by the first acquisition process, and a second remaining amount, which is the remaining amount acquired by the second acquisition process; and a second liquid delivery process to control the liquid delivery mechanism based on the calculation time calculated by the calculation process and deliver the liquid from the second tank to the first tank through the pipe.

Like the first aspect, the fourth aspect contributes to bringing the actual amount of liquid remaining in the tank after circulation closer to the actual amount of liquid remaining in the tank before circulation.

FIG. 2 is a diagram showing the flow path configuration of the liquid supply system 100. FIG. 2 is a block diagram showing the electrical configuration of the printer 1. 2 is a block diagram showing an electrical configuration of the liquid supply device 2. FIG. 1 is a graph showing a change in server remaining capacity V with respect to operating time t. 13 is a flowchart of a main process. 13 is a flowchart of a circulation process. 13 is a flowchart of a circulation process. 11 is a graph showing a change in a reading value m of a server sensor 71 with respect to a drive time t.

<Outline of the liquid supply system 100>

A liquid supply system 100 according to one embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the liquid supply system 100 includes a plurality of printers 1 and a liquid supply device 2. The liquid supply system 100 supplies liquid, such as ink, from the liquid supply device 2 to each of the plurality of printers 1.

The number of printers 1 is not limited to a specific number, but for example, four printers 1A, 1B, 1C, and 1D are connected to one liquid supply device 2. The printer 1 is, for example, an inkjet printer, which ejects ink onto a print medium (not shown) to perform printing. The print medium is cloth, paper, etc., such as a T-shirt.

The inks are, for example, white (W), black (K), yellow (Y), cyan (C), or magenta (M). In the following, the white ink among the five colors of ink will be referred to as "white ink", and when the four colors of ink, black, cyan, yellow, and magenta, are collectively referred to or when one of them is not specified, they will be referred to as "color ink".

White ink is used in printing to represent the white part of an image, or as a base for colored inks. Colored inks are jetted directly onto the print medium, or onto a white ink base, to print color images.

<Mechanical configuration of printer 1>

The printer 1 includes a platen 15, a carriage 13, and a head 14, as shown in FIG. 2. The platen 15 is provided so as to be movable in the sub-scanning direction. A print medium is placed on the platen 15. The carriage 13 is provided so as to be movable in the main scanning direction. The main scanning direction is perpendicular to the sub-scanning direction.

The head 14 is attached to the carriage 13 and moves in the main scanning direction together with the carriage 13. The head 14 includes nozzles and ejects white ink from the nozzles onto the printing medium on the platen 15. In addition to the head 14, the printer 1 also includes one or more heads (hereinafter referred to as "other heads"). In this embodiment, the other heads are not illustrated and their description is simplified. The other heads differ from the head 14 in that they eject color inks, instead of white ink, from the nozzles onto the printing medium on the platen 15.

The printer 1 is equipped with a printer tank 17W. The printer tank 17W receives a supply of white ink from the liquid supply device 2 and stores the supplied white ink. The printer tank 17W is connected to the head 14 shown in FIG. 2 via a tube (not shown).

The printer 1 includes multiple printer tanks (hereinafter referred to as "other printer tanks") in addition to the printer tank 17W. In this embodiment, the other printer tanks are not shown and their description is simplified. The other printer tanks differ from the printer tank 17W in that they receive color ink instead of white ink from the liquid supply device 2. The other printer tanks are connected to other heads via tubes (not shown).

By driving the supply mechanism 184 shown in FIG. 2, white ink is supplied from the printer tank 17W to the head 14 shown in FIG. 2 via a tube (not shown). Similarly, color inks are supplied from the other printer tanks to the other heads. By driving the main scanning motor 181 shown in FIG. 2, the carriage 13 moves in the main scanning direction. By driving the sub-scanning motor 182 shown in FIG. 2, the platen 15 moves in the sub-scanning direction. As a result, the head 14 moves relative to the printing medium on the platen 15 in the main scanning direction and the sub-scanning direction.

While the head 14 moves relative to the print medium on the platen 15 in the main scanning direction and sub-scanning direction, the head driver 183 shown in FIG. 2 drives the head 14 to eject white ink from its nozzles onto the print medium on the platen 15. Similarly, the other heads eject color inks from their nozzles onto the print medium on the platen 15. In this way, the printer 1 performs the print process of printing onto the print medium.

<Mechanical configuration of liquid supply device 2>

The liquid supply device 2 comprises a server tank 6W, a pipe 8, and an agitation mechanism 96. The server tank 6W is located outside the multiple printers 1 and contains white ink. The capacity of the server tank 6W to contain white ink is greater than the capacity of one printer tank 17W to contain white ink, and is greater than the combined capacity of each of the printer tanks 17W of printers 1A, 1B, 1C, and 1D. The pipe 8 forms a flow path for white ink between the server tank 6W and each of the printer tanks 17W of the multiple printers 1.

The stirring mechanism 96 is, for example, a propeller stirrer, and performs a stirring operation to stir the white ink in the server tank 6W by driving the stirring motor 963 shown in FIG. 3. In this embodiment, the white ink contains, as solid components such as pigment particles, components that have a higher sedimentation rate than the components contained in the color inks. The component with a higher sedimentation rate is, for example, titanium oxide. Titanium oxide is a type of inorganic pigment with a relatively high specific gravity. Since the white ink contains components that have a relatively higher sedimentation rate, the solid components such as pigment particles in the white ink tend to settle. Hereinafter, the settling of solid components in the white ink is also referred to as "white ink settling." The stirring mechanism 96 performs a stirring operation to suppress the settling of the white ink in the server tank 6W.

The liquid supply device 2 includes multiple server tanks (hereinafter referred to as "other server tanks") in addition to the server tank 6W, and multiple pipes (hereinafter referred to as "other pipes") in addition to the pipe 8. In this embodiment, the other server tanks and other pipes are not illustrated, and their description is simplified.

The other server tanks differ from server tank 6W in that they contain color inks instead of white ink. The other tubes form flow paths for color inks between the other server tanks and the other printer tanks of each of the multiple printers 1. The other tubes differ from tube 8 in that they do not include tubes 84, 85, and 86, which will be described later. Note that in this embodiment, the other server tanks are not provided with a stirring mechanism 96.

<White ink flow path configuration>

The white ink flow path includes a first white flow path W1 and a second white flow path W2. Note that in FIG. 1, the first white flow path W1 is shown by a solid line, and the second white flow path W2 is shown by a dashed line. The first white flow path W1 connects the server tank 6W to the printer tanks 17W of the printers 1A and 1B. The second white flow path W2 connects the server tank 6W to the printer tanks 17W of the printers 1C and 1D.

The first white flow path W1 and the second white flow path W2 differ in whether the connection destination from the liquid supply device 2 is printer 1A, 1B or printer 1C, 1D. Therefore, below, the first white flow path W1 will be described, and the second white flow path W2 will be given the same reference numeral as the first white flow path W1, and the description will be omitted or simplified.

The first white flow path W1 is composed of pipes 81, 82, 83, 84, 85, and 86 as pipe 8. Pipe 81 connects to server tank 6W. Pipe 81 extends from server tank 6W to point P1. Pipe 81 connects to pipes 82 and 83 at point P1.

Pipe 82 extends from point P1 through point P2 toward printer tank 17W of printer 1A and connects to printer tank 17W of printer 1A. Pipe 83 extends from point P1 through point P3 toward printer tank 17W of printer 1B and connects to printer tank 17W of printer 1B.

Pipe 84 connects to pipe 82 at point P2. Pipe 84 extends from point P2 to point P4 and connects to pipe 86 at point P4. Pipe 85 connects to pipe 83 at point P3. Pipe 85 extends from point P3 to point P4 and connects to pipe 86 at point P4. Pipe 86 extends from point P4 towards server tank 6W and connects to server tank 6W.

In the following, the flow path from the server tank 6W through pipes 81 and 82 to the printer tank 17W of printer 1A, and the flow path from the server tank 6W through pipes 81 and 83 to the printer tank 17W of printer 1B are each referred to as the "supply flow path." In the supply flow path, the server tank 6W side is referred to as the "upstream supply flow path," and the printer tank 17W side of printer 1A or printer 1B is referred to as the "downstream supply flow path." For example, at the midpoint of the supply flow path, the server tank 6W side is the upstream supply flow path, and the printer tank 17W side of printer 1A or printer 1B is the downstream supply flow path.

The flow path from printer tank 17W of printer 1A to server tank 6W via pipes 84 and 86, and the flow path from printer tank 17W of printer 1B to server tank 6W via pipes 85 and 86 are each referred to as the "circulation flow path." In the circulation flow path, the printer tank 17W side of printer 1A or printer 1B is referred to as the "upstream circulation flow path," and the server tank 6W side is referred to as the "downstream supply flow path." For example, at the midpoint of the circulation flow path, the printer tank 17W side of printer 1A or printer 1B is the upstream circulation flow path, and the server tank 6W side is the downstream circulation flow path.

Pipe 82 is provided with a supply pump 20, a supply valve 22, and a filter 24. Pipe 83 is provided with a supply pump 21, a supply valve 23, and a filter 25. Supply pump 20 is located upstream of point P2 in the supply flow path. Supply pump 21 is located upstream of point P3 in the supply flow path.

The supply pumps 20 and 21 respectively suck white ink from the server tank 6W through a tube 81 by driving pump motors 201 and 211 shown in FIG. 3. The supply pump 20 sends the sucked white ink through a tube 82 toward the printer tank 17W of the printer 1A by driving pump motor 201 shown in FIG. 3. The supply pump 21 sends the sucked white ink through a tube 83 toward the printer tank 17W of the printer 1B by driving pump motor 211 shown in FIG. 3.

In the following, the state in which the valve is closed is referred to as the "closed state," and the state in which the valve is open is referred to as the "open state." In the closed state, the valve blocks the flow path. In the open state, the valve opens the flow path.

The supply valve 22 is located upstream of the supply pump 20 in the supply flow path. The supply valve 23 is located upstream of the supply pump 21 in the supply flow path. The supply valves 22 and 23 are switched between a closed state and an open state by the drive of the solenoids 221 and 231 shown in FIG. 3, respectively. The supply valve 22 blocks the pipe 82 in the closed state, and opens the pipe 82 in the open state. The supply valve 23 blocks the pipe 83 in the closed state, and opens the pipe 83 in the open state.

Filter 24 is located upstream of supply valve 22 in the supply flow path. Filter 25 is located upstream of supply valve 23 in the supply flow path. Filters 24 and 25 are each made of, for example, nonwoven fabric, woven fabric, resin film, or porous metal piece, and filter the white ink.

A circulation pump 26 and a circulation valve 28 are provided in the pipe 84. A circulation pump 27 and a circulation valve 29 are provided in the pipe 85. The circulation pump 26, driven by the pump motor 261 shown in FIG. 3, draws white ink from the printer tank 17W of the printer 1A through a portion of the pipe 82 downstream of the supply flow path from point P2. The circulation pump 27, driven by the pump motor 271 shown in FIG. 3, draws white ink from the printer tank 17W of the printer 1B through a portion of the pipe 83 downstream of the supply flow path from point P3. The circulation pumps 26 and 27, driven by the pump motors 261 and 271 shown in FIG. 3, respectively, send the drawn white ink through the pipe 86 toward the server tank 6W.

Circulation valve 28 is located downstream of circulation pump 26 in the circulation flow path. Circulation valve 29 is located downstream of circulation pump 27 in the circulation flow path. Circulation valves 28, 29 are switched between a closed state and an open state by the drive of solenoids 281, 291 shown in FIG. 3, respectively. Circulation valve 28 blocks pipe 84 in the closed state, and opens pipe 84 in the open state. Circulation valve 29 blocks pipe 85 in the closed state, and opens pipe 85 in the open state.

In the above configuration, the liquid supply system 100 supplies white ink from the server tank 6W to the printer tank 17W via the tube 8 by driving the supply pump 20 or the supply pump 21 that corresponds to the valve that is open while one or both of the supply valves 22 and 23 are open.

Hereinafter, the operation of the liquid supply system 100 to supply white ink from the server tank 6W to the printer tank 17W via the pipe 8 is referred to as the "supply operation." In the supply operation of this embodiment, the liquid supply system 100 can supply white ink from the server tank 6W via the pipe 8 to each of the printer tanks 17W of the multiple printers 1 in parallel or to each of the multiple printers 1 one by one. In other words, the multiple server tanks 6W are each located upstream of each of the multiple printers 1 in the supply flow path to each of the multiple printers 1.

As an example of the flow of white ink when a supply operation is performed, the flow of white ink in the first white flow path W1 from the server tank 6W through tube 8 toward the printer tank 17W of each of printers 1A and 1B will be described. When white ink is supplied from the server tank 6W to the printer tank 17W of printer 1A, the white ink flows from inside the server tank 6W through tubes 81 and 82 toward the printer tank 17W of printer 1A (see arrow A1). When white ink is supplied from the server tank 6W to the printer tank 17W of printer 1B, the white ink flows from inside the server tank 6W through tubes 81 and 83 toward the printer tank 17W of printer 1B (see arrow A2).

The liquid supply system 100 returns white ink from the printer tank 17W to the server tank 6W via the pipe 8 by driving the circulation pump 26 or the circulation pump 27, whichever corresponds to the open valve, while one or both of the circulation valves 28 and 29 are open.

Hereinafter, the operation of the liquid supply system 100 returning white ink from the printer tank 17W to the server tank 6W via the pipe 8 is referred to as the "return operation." In the return operation of this embodiment, the liquid supply system 100 can return white ink from each of the printer tanks 17W of multiple printers 1 to the server tank 6W via the pipe 8 in parallel or one printer at a time.

As an example of the flow of white ink when a return operation is performed, the flow of white ink from the printer tank 17W of each of printers 1A and 1B toward the server tank 6W through tube 8 in the first white flow path W1 will be described. When white ink is returned from the printer tank 17W of printer 1A to the server tank 6W, the white ink flows from inside the printer tank 17W of printer 1A toward the server tank 6W through tube 82, point P2, tube 84, and tube 86 (see arrow B1). When white ink is returned from the printer tank 17W of printer 1B to the server tank 6W, the white ink flows from inside the printer tank 17W of printer 1B toward the server tank 6W through tube 83, point P3, tube 85, and tube 86 (see arrow B2).

White ink flows through the portion of pipe 82 downstream of point P2 in both cases where white ink is supplied from the server tank 6W to the printer tank 17W of printer 1A and where white ink is returned from the printer tank 17W of printer 1A to the server tank 6W. White ink flows through the portion of pipe 83 downstream of point P3 in both cases where white ink is supplied from the server tank 6W to the printer tank 17W of printer 1B and where white ink is returned from the printer tank 17W of printer 1B to the server tank 6W.

The liquid supply system 100 can circulate white ink through the tube 8 between the server tank 6W and each printer tank 17W of the multiple printers 1 by performing one of the supply operation and the return operation and then the other. The liquid supply system 100 can circulate white ink through the tube 8 between the server tank 6W and each printer tank 17W of the multiple printers 1 by alternately repeating the supply operation and the return operation.

Hereinafter, the operation of the liquid supply system 100 to circulate white ink between the server tank 6W and the printer tank 17W via the tube 8 is referred to as the "circulation operation." The liquid supply system 100 performs the circulation operation, for example, in the first white flow path W1. In this way, the liquid supply system 100 suppresses the settling of white ink in the server tank 6W, the first white flow path W1, and the printer tanks 17W of each of the printers 1A and 1B.

<Printer 1 electrical configuration>

As shown in FIG. 2, the printer 1 includes a control device 40. The control device 40 includes a CPU 41, a ROM 42, a RAM 43, a flash memory 44, and a communication unit 45. The CPU 41 controls the printer 1 and functions as a processor. The CPU 41 controls, for example, the printing process. The CPU 41 is electrically connected to the ROM 42, the RAM 43, the flash memory 44, and the communication unit 45.

The ROM 42 stores the control program for the CPU 41 to control the operation of the printer 1, and information required by the CPU 41 when executing various programs. The RAM 43 temporarily stores various data used in the control program. The flash memory 44 is non-volatile, and stores calibration data for the printer sensor 185 described below. The communication unit 45 is a controller for communicating with external devices via wired or wireless communication. The CPU 41 communicates with, for example, the liquid supply device 2 via the communication unit 45.

The main scanning motor 181, the sub-scanning motor 182, the head driver 183, the supply mechanism 184, the printer sensor 185, and the operation unit 186 are electrically connected to the CPU 41. The main scanning motor 181, the sub-scanning motor 182, the head driver 183, and the supply mechanism 184 are driven under the control of the CPU 41.

The printer sensor 185 is provided in the printer tank 17W shown in FIG. 1. The printer sensor 185 is, for example, a pressure sensor. The printer sensor 185 detects the pressure inside the printer tank 17W to detect the printer remaining amount. The printer remaining amount is the remaining amount of white ink inside the printer tank 17W. The printer sensor 185 outputs a signal indicating the detected printer remaining amount to the CPU 41.

The operation unit 186 is a touch panel display or the like that displays various information and outputs information to the CPU 41 according to operations by the user. By operating the operation unit 186, the user can input print instructions to the printer 1 to start printing by the printer 1, etc.

<Electrical configuration of liquid supply device 2>

As shown in FIG. 3, the liquid supply device 2 includes a control device 50. The control device 50 includes a CPU 51, a ROM 52, a RAM 53, a flash memory 54, and a communication unit 55. The CPU 51 controls the liquid supply device 2 and functions as a processor. The CPU 51 is electrically connected to the ROM 52, the RAM 53, the flash memory 54, and the communication unit 55.

The ROM 52 stores the control program for the CPU 51 to control the operation of the liquid supply device 2, and information required by the CPU 51 when executing various programs. The RAM 53 temporarily stores various data used in the control program. The flash memory 54 is non-volatile and stores calibration data for the server sensor 71, etc. The communication unit 55 is a controller for communicating with external devices via wired or wireless communication. The CPU 51 communicates with, for example, each of the printers 1A, 1B, 1C, and 1D via the communication unit 55.

The CPU 51 is electrically connected to the agitator motor 963, pump motors 201, 211, 261, 271, solenoids 221, 231, 281, 291, server sensor 71, display 56, and operation unit 57.

The stirring motor 963, pump motors 201, 211, 261, 271, solenoids 221, 231, 281, 291, and display 56 are driven under the control of the CPU 51. The server sensor 71 is a weight sensor using, for example, a load cell, and detects the server remaining amount by weight. The server remaining amount is the remaining amount of white ink in the server tank 6W. The server sensor 71 outputs a signal indicating the detected server remaining amount to the CPU 51.

＜Changes in the external environment＞

The values indicated by the signals output by the server sensor 71 and the printer sensor 185 may fluctuate depending on the effect that changes in the external environment have on the server sensor 71 and the printer sensor 185. For example, the smaller the effect that changes in the external environment have on the server sensor 71 and the printer sensor 185, the smaller the amount of fluctuation in the values indicated by the signals output by the server sensor 71 and the printer sensor 185. Changes in the external environment that the server sensor 71 and the printer sensor 185 are subjected to include, for example, changes in air pressure, changes in temperature, or changes in the amount of remaining white ink.

For example, when the air pressure or temperature changes, the smaller of the amount of fluctuation in the value indicated by the signal output from the server sensor 71 and the amount of fluctuation in the value indicated by the signal output from the printer sensor 185 is less affected by changes in the external environment. Because the printer sensor 185 is a pressure sensor and the server sensor 71 is a weight sensor, the server sensor 71 is less affected by changes in air pressure than the printer sensor 185.

Specifically, the printer sensor 185 includes a detection tube that is open at one end and connected to a detection element at the other end, and detects the air pressure inside the detection tube that is blocked by the ink level that has entered through the opening. For this reason, the printer sensor 185 is susceptible to the effects of gas contraction or expansion due to temperature changes. Therefore, the server sensor 71 is less susceptible to changes in temperature than the printer sensor 185.

The printer remaining amount decreases when a printing process using white ink is performed. The printer remaining amount changes due to the circulation of white ink between the printer tank 17W and the head 14. On the other hand, the server remaining amount changes due to a circulation operation or a supply operation. In this case, the printer remaining amount changes in the same way as the server remaining amount. For this reason, the frequency with which the remaining amount of white ink changes is lower for the server remaining amount than for the printer remaining amount. Therefore, the server sensor 71 is less affected by changes in the remaining amount of white ink than the printer sensor 185.

As a result of the above, the server sensor 71 is less affected by changes in the external environment than the printer sensor 185 is affected by changes in the external environment. Therefore, the CPU 51 obtains the server remaining capacity based on the signal from the server sensor 71, and controls the circulation operation based on the obtained server remaining capacity.

＜Changes in remaining amount due to circulation＞

Below, we will explain the change in the server remaining amount during the circulation operation with reference to Figure 4, but the change in the printer remaining amount can also be said to be similar to the change in the server remaining amount, with the increase and decrease in the remaining amount simply reversing, provided that the total amount of the server remaining amount and the printer remaining amount does not change during the circulation operation. In Figure 4, the horizontal axis indicates the operating time t of the supply pump 20 or supply pump 21, and the vertical axis indicates the server remaining amount V. The server remaining amount at the start of the circulation operation is called the "pre-circulation remaining amount," and the server remaining amount at the end of the circulation operation is called the "post-circulation remaining amount." The server remaining amount indicated by the signal from the server sensor 71 shown in Figure 3 is also called the "server remaining amount based on the server sensor 71."

In this embodiment, the resolution of the A/D converter (not shown) provided between the CPU 41 and the printer sensor 185 is the same as that of the A/D converter (not shown) provided between the CPU 51 and the server sensor 71. Furthermore, as described above, the capacity of the server tank 6W is larger than the capacity of the printer tank 17W, so the server tank 6W detects a wider remaining amount range than the printer sensor 185. For this reason, in this embodiment, the resolution of the server sensor 71 is lower than that of the printer sensor 185. For example, the lower the resolution of the server sensor 71, the greater the deviation of the server remaining amount based on the server sensor 71 from the actual server remaining amount. In particular, at the start of the circulation operation, the pre-circulation remaining amount based on the server sensor 71 may deviate from the actual pre-circulation remaining amount. If the pre-circulation remaining amount based on the server sensor 71 deviates from the actual pre-circulation remaining amount, the post-circulation remaining amount may change from the actual pre-circulation remaining amount even if the circulation operation is controlled so that the post-circulation remaining amount is the pre-circulation remaining amount based on the server sensor 71.

For example, if the amount of ink remaining after circulation decreases from the actual amount of ink remaining before circulation, the amount of ink remaining in the printer increases by the amount of ink remaining each time the circulation operation is repeated. In this case, there is a possibility that white ink may overflow from the printer tank 17W.

In the circulation operation of this embodiment, a return operation is performed after a supply operation. Therefore, when the circulation operation starts at time T0, the server remaining amount V is reduced from the actual remaining amount before circulation Vs by the supply operation. The supply operation is performed for a supply time Ts until the drive time t reaches time T3. When the supply time Ts has elapsed from the start of the circulation operation (time T0) and the drive time t reaches time T3, the supply operation is stopped and the return operation is performed.

In the following, the server remaining amount V at the end of the supply operation is referred to as the "post-supply remaining amount Vb." The server remaining amount V increases from the post-supply remaining amount Vb by the return operation. For example, if the pre-circulation remaining amount Va based on the server sensor 71 is less than the actual pre-circulation remaining amount Vs due to the resolution of the server sensor 71, at time T4 when the server remaining amount V based on the server sensor 71 reaches the pre-circulation remaining amount Va based on the server sensor 71, the actual server remaining amount V may be less than the actual pre-circulation remaining amount Vs.

In this embodiment, the details will be described later, but the added time Tc is calculated based on the pre-circulation remaining amount Va based on the server sensor 71 and the post-supply remaining amount Vb based on the server sensor 71. Furthermore, in the return operation, after the server remaining amount V based on the server sensor 71 becomes the pre-circulation remaining amount Va based on the server sensor 71, an additional return operation for the added time Tc is performed from time T4 to time T5. When the added time Tc has elapsed from time T4 and the drive time t reaches time T5, the return operation is stopped and the circulation operation ends. As a result, the actual server remaining amount V increases from the server remaining amount Va to the server remaining amount Ve according to the added time Tc. Therefore, the liquid supply system 100 contributes to bringing the actual post-circulation remaining amount Ve closer to the actual pre-circulation remaining amount Vs.

＜Main processing＞

For example, when the liquid supplying device 2 is powered on, or when the server tank 6W shown in FIG. 1 is replaced, the CPU 51 executes the main processing shown in FIG. 5 by reading and running a control program from the ROM 52. For example, when the CPU 51 detects that the power button (not shown) has been operated by the user via the operation unit 186 shown in FIG. 2, it determines that the liquid supplying device 2 is powered on.

In this embodiment, replacing the server tank 6W includes refilling the server tank 6W with white ink and replacing the old server tank 6W with a new server tank 6W. When the user replaces the server tank 6W, for example, the user operates the operation unit 186 shown in FIG. 2 to input information indicating that the server tank 6W has been replaced to the liquid supplying device 2. When the CPU 51 detects, for example, information indicating that the server tank 6W has been replaced via the operation unit 186, it determines that the server tank 6W has been replaced.

In the main processing, the CPU 51 controls the supply and return operations. In the main processing, the supply and return operations of the second white flow path W2 are controlled in the same manner as the first white flow path W1. In this embodiment, the control of the first white flow path W1 in the main processing is described, and the description of the control of the second white flow path W2 is omitted.

In the main process, a circulation flag is used. The circulation flag is stored in RAM 53 and indicates whether or not the first circulation operation has been performed after the liquid supplying device 2 has been powered on or the server tank 6W has been replaced. In this embodiment, if the first circulation operation has not been performed after the liquid supplying device 2 has been powered on or the server tank 6W has been replaced, the circulation flag is set to "0". If the first circulation operation has been performed after the liquid supplying device 2 has been powered on or the server tank 6W has been replaced, the circulation flag is set to "1".

As shown in FIG. 5, when the main process starts, the CPU 51 performs an initial process (S11). In the initial process, the CPU 51 controls the solenoids 221, 231, 281, and 291 shown in FIG. 3 to close all of the supply valves 22 and 23 and the circulation valves 28 and 29 shown in FIG. 1. The CPU 51 sets the circulation flag to "0".

The CPU 51 determines (S12) whether or not a supply request for performing a supply process (S13) described below has been acquired from the printer 1A or the printer 1B. For example, when the printer 1A performs a printing process using white ink, the white ink in the printer tank 17W of the printer 1A is consumed, and the printer remaining amount of ink in the printer 1A decreases. For example, in the printer 1A, when the printer remaining amount falls below a predetermined supply start remaining amount, the CPU 41 sends a supply request to the liquid supply device 2. The supply start remaining amount is stored in advance in, for example, the flash memory 44.

If a supply request has not been received from either printer 1A or 1B (S12: NO), the CPU 51 proceeds to S14. If a supply request has been received from printer 1A or printer 1B (S12: YES), the CPU 51 performs the supply process (S13).

In the supply process (S13), the CPU 51 controls the supply operation for the printer tank 17W of the printer 1 from which the supply request was acquired. For example, when a supply request is acquired from the printer 1A, the CPU 51 controls the solenoid 221 shown in FIG. 3 in the supply operation to open the supply valve 22 shown in FIG. 1. In this state, the CPU 51 controls the pump motor 201 shown in FIG. 3 to start driving the supply pump 20 shown in FIG. 1. As a result, white ink is supplied from the server tank 6W through the tube 8 to the printer tank 17W of the printer 1A.

For example, when the printer remaining amount reaches a predetermined supply stop remaining amount due to the supply operation, the CPU 41 sends a supply stop request to the liquid supply device 2. The supply stop remaining amount is stored in advance, for example, in the flash memory 44. The supply stop remaining amount is, for example, greater than the supply start remaining amount. For example, when a supply stop request is received from the printer 1A, the CPU 51 stops driving the pump motor 201 shown in FIG. 3 and stops driving the supply pump 20 shown in FIG. 1. The CPU 51 controls the solenoid 221 shown in FIG. 3 to close the supply valve 22 shown in FIG. 1. This causes the CPU 51 to stop the supply operation and end the supply process.

The CPU 51 refers to the timer counter in the RAM 53 and determines whether the circulation interval has elapsed for each of the printers 1A and 1B (S14). In this embodiment, a circulation process (S15) described below is performed periodically for the printer tank 17W of each of the printers 1A and 1B. A first circulation process and a second circulation process are defined. The first circulation process is one of the circulation processes that are performed periodically. The second circulation process is one of the circulation processes that is performed periodically and follows the first circulation process. The circulation interval is the time between the first circulation process and the second circulation process, and is stored in advance in the flash memory 54, for example. The circulation interval is not limited to a specific length, but is, for example, four hours.

If the circulation interval has not elapsed for either printer 1A or 1B (S14: NO), the CPU 51 returns the process to S12. Hereinafter, the printer 1 for which the circulation interval has elapsed is referred to as the "target printer." If the circulation interval has elapsed for printer 1A or printer 1B (S14: YES), the CPU 51 performs circulation processing for the target printer (S15). In the circulation processing, the CPU 51 controls the circulation operation for the printer tank 17W of the target printer. The CPU 51 returns the process to S12.

The circulation process (S15) will be described in detail with reference to Figures 6 and 7. As shown in Figure 6, when the circulation process is started, the CPU 51 acquires the server remaining amount V from the server sensor 71 shown in Figure 3 (S21). The CPU 51 stores the server remaining amount V acquired in the process of S21 in the RAM 53 as the pre-circulation remaining amount Va (see Figure 4) (S22).

The CPU 51 starts the supply operation for the printer tank 17W of the target printer (S23, time T0 shown in FIG. 4). For example, if the target printer is printer 1A, in the process of S23, the CPU 51 controls the solenoid 221 shown in FIG. 3 to open the supply valve 22 shown in FIG. 1. In this state, the CPU 51 controls the pump motor 201 shown in FIG. 3 to start driving the supply pump 20 shown in FIG. 1. As a result, white ink is supplied from the server tank 6W through the tube 8 to the printer tank 17W of printer 1A (target printer).

The CPU 51 refers to the timer counter in the RAM 53 and determines whether the supply time Ts shown in FIG. 4 has elapsed (S24). The supply time Ts is the time from the start to the end of the supply operation, and is stored in advance in, for example, the flash memory 54.

If the supply time Ts has not elapsed (S24: NO), the CPU 51 repeats the process of S24 until the supply time Ts has elapsed. If the supply time Ts has elapsed (S24: YES, time point T3 shown in FIG. 4), the CPU 51 stops the supply operation for the printer tank 17W of the target printer (S25). In the process of S25, the CPU 51 stops the drive of the pump motor 201 shown in FIG. 3, for example, and stops the drive of the supply pump 20 shown in FIG. 1. The CPU 51 controls the solenoid 221 shown in FIG. 3 to close the supply valve 22 shown in FIG. 1. This stops the supply of white ink from the server tank 6W to the printer tank 17W of the printer 1A (target printer) via the pipe 8.

The CPU 51 acquires the server remaining amount V from the server sensor 71 shown in FIG. 3 (S31). The CPU 51 stores the server remaining amount V acquired in the process of S31 in the RAM 53 as the post-supply remaining amount Vb (S32). The CPU 51 calculates the calculation time Tb shown in FIG. 8 by a predetermined calculation formula based on the pre-circulation remaining amount Va stored in the process of S22 and the post-supply remaining amount Vb stored in the process of S32 (S33). The calculation formula is stored in advance in, for example, the flash memory 54. The calculation time Tb is the time for calculating the addition time Tc shown in FIG. 4. The CPU 51 stores the calculated calculation time Tb in the RAM 53. Hereinafter, the latest calculation time Tb stored in the RAM 53 is also referred to as the "current calculation time Tb".

The calculation formula used in the process of S33 will be described with reference to FIG. 8. In FIG. 8, the horizontal axis indicates the drive time t of the supply pump 20 or supply pump 21, and the vertical axis indicates the reading value m of the server sensor 71. The reading value m corresponds to the server remaining amount V based on the server sensor 71. Therefore, the difference in the reading value m between two different points (e.g., M1-M2) corresponds to the amount of white ink supplied from the server tank 6W to the printer tank 17W of the target printer through the tube 8 by the supply pump 20 or supply pump 21. More specifically, the reading value m is a value that the CPU 51 reads from the signal output from the server sensor 71 to the CPU 51. The reading value m decreases by one in the order of M1, M1-1, ..., M2+1, M2.

Time T0 is the start point of the supply operation (processing S23). Reading M1 is reading m at time T0 and corresponds to the pre-circulation remaining amount Va based on the server sensor 71 (see FIG. 4). Reading M2 is reading m at time T3 and corresponds to the server remaining amount Vb based on the server sensor 71 (see FIG. 4). FIG. 8 shows a case where reading m changes from reading M1 to reading M2 within supply time Ts due to the supply operation.

In this embodiment, the supply pump 20 or the supply pump 21 rotates at a constant speed for a predetermined supply time Ts from when the supply operation is started in the process of S23 until the supply operation is stopped in the process of S25. When the supply pump 20 or the supply pump 21 rotates at a constant speed, the amount of white ink supplied by the supply pump 20 or the supply pump 21 from the server tank 6W to the printer tank 17W of the target printer through the tube 8 is proportional to the drive time t of the supply pump 20 or the supply pump 21. Therefore, the time Ta required for the reading value m of the server sensor 71 to change by "1" is represented by the following formula (1) or formula (2). The CPU 51 may use either formula (1) or formula (2) in the process of S23.
Ta=Ts/(M1-M2)...Formula (1)
Ta=(T2-T1)/[(M1-1)-(M2+1)]...Formula (2)

For example, since the reading value M1 is the reading value m at time T0, it is difficult to determine the deviation between the server remaining capacity V corresponding to the reading value M1 and the actual server remaining capacity V. In contrast, the reading value (M1-1) corresponds to the server remaining capacity V at the time when the reading value m switches from the reading value M1 to the reading value (M1-1), regardless of the drive time t. For this reason, the deviation between the server remaining capacity V corresponding to the reading value (M1-1) and the actual server remaining capacity V is likely to be determined to a constant value. Therefore, the deviation between the actual server remaining capacity V and the reading value (M1-1) varies less than the reading value M1.

For example, since the reading value M2 is the reading value m at the time T3 when the supply time Ts has elapsed, the deviation between the server remaining capacity V corresponding to the reading value M2 and the actual server remaining capacity V is difficult to determine. In contrast, the reading value (M2+1) corresponds to the server remaining capacity V at the time when the reading value m switches from the reading value (M2+2) to the reading value (M2+1), regardless of the drive time t. For this reason, the deviation between the server remaining capacity V corresponding to the reading value (M2+1) and the actual server remaining capacity V is likely to be determined to a constant value. Therefore, the deviation between the actual server remaining capacity V and the reading value (M2+1) varies less than the reading value M2.

In formula (1), the readings M1 and M2 are used. In formula (2), the readings (M1-1) and (M2+1) are used instead of the readings M1 and M2. As described above, the readings (M1-1) and (M2+1) have smaller variations in the deviation from the actual server remaining capacity V than the readings M1 and M2, so the variation in time Ta is smaller in formula (2) than in formula (1). On the other hand, in formula (1), the readings M1 and M2 are used as is. Furthermore, in formula (2), the CPU 51 must determine the drive time t when the reading m becomes the reading (M1-1) as time T1, and the drive time t when the reading m becomes the reading (M2+1) as time T2, and specify the times T1 and T2. For this reason, the CPU 51 can calculate the time Ta more easily using formula (1) than using formula (2).

In the process of S33, the CPU 51 calculates the calculation time Tb by the following formula (3) based on the time Ta calculated by formula (1) or (2).
Tb=α×Ta...Formula (3)
The coefficient α is not limited to a specific value, but is, for example, less than 1, and in this embodiment, is 1/2. That is, in this embodiment, half of the time Ta is the calculation time Tb. As described above, the time Ta is the time it takes for the reading value m of the server sensor 71 to change by "1". Therefore, the calculation time Tb is the time it takes for the reading value m of the server sensor 71 to change by the coefficient α.

Returning to the explanation of FIG. 6, the CPU 51 judges whether the circulation operation being performed is the first circulation operation after the power supply device 2 is turned on or the first circulation operation after the server tank 6W is replaced based on the state of the circulation flag (S41). If the circulation flag is set to "0", the CPU 51 judges that the circulation operation being performed is the first circulation operation after the power supply device 2 is turned on or the first circulation operation after the server tank 6W is replaced (S41: YES). In this case, it is relatively likely that the current calculated time Tb has changed significantly from the previous added time Tc. Therefore, the CPU 51 stores the current calculated time Tb as the added time Tc in the RAM 53 (S44). The previous added time Tc is a time based on the calculated time Tb calculated in the previous processing of S33, and is the latest added time Tc stored in the RAM 53 at the time before the processing of S44 and S46 is performed. The CPU 51 proceeds to the processing of S51 shown in FIG. 7.

If the circulation flag is set to "1", the CPU 51 determines that the ongoing circulation operation is neither the first circulation operation after the liquid supply device 2 is powered on nor the first circulation operation after the server tank 6W is replaced (S41: NO). In this case, it is relatively unlikely that the current calculated time Tb has changed significantly from the previous added time Tc. The CPU 51 calculates the difference between the current calculated time Tb and the previous added time Tc (S42). The added time Tc is stored in the RAM 53 in the process of S44 or the process of S46 described below.

For example, if the configuration of the pipe 8 (length, diameter) is changed, if the supply pumps 20 and 21 are changed, if the vertical positional relationship between the printer tank 17W and the server tank 6W is changed, or if the configuration related to the flow path between the printer tank 17W and the server tank 6W (hereinafter simply referred to as the "flow path configuration") is changed, the difference between the previous added time Tc and the current calculated time Tb may become large. On the other hand, if the difference between the previous added time Tc and the current calculated time Tb is small, it is highly likely that the flow path configuration has not changed. For this reason, the CPU 51 determines whether the difference between the previous added time Tc and the current calculated time Tb is equal to or greater than a predetermined value (S43). The predetermined value is a value for determining the possibility that the flow path configuration has been changed, and is stored in advance in the flash memory 54.

If the difference between the previous added time Tc and the current calculated time Tb is equal to or greater than a predetermined value (S43: YES), there is a relatively high possibility that the flow path configuration has been changed. In this case, it is preferable to set the added time Tc to a time corresponding to the changed flow path configuration. In other words, it is preferable to set the calculated time Tb calculated in the processing of S33 when the flow path configuration has been changed as the added time Tc. Therefore, the CPU 51 stores the current calculated time Tb as the added time Tc in the RAM 53 (S44). The CPU 51 proceeds to the processing of S51 shown in FIG. 7.

If the difference between the previous added time Tc and the current calculated time Tb is less than a predetermined value (S43: NO), the possibility that the flow path configuration has been changed is relatively low. In this case, the previous added time Tc is taken into account as the added time Tc, thereby increasing the accuracy of the added time Tc. For this reason, the CPU 51 stores the time based on the previous added time Tc and the current calculated time Tb as the added time Tc in the RAM 53 (S46). The time based on the previous added time Tc and the current calculated time Tb is, for example, the average of the previous added time Tc and the current calculated time Tb. The time based on the previous added time Tc and the current calculated time Tb may be calculated by weighting the previous added time Tc and the current calculated time Tb. The CPU 51 proceeds to the process of S51 shown in FIG. 7.

As shown in FIG. 7, the CPU 51 starts the return operation for the printer tank 17W of the target printer (S51, time point T3 shown in FIG. 4). For example, if the target printer is printer 1A, in the process of S51, the CPU 51 controls the solenoid 281 shown in FIG. 3 to open the circulation valve 28 shown in FIG. 1. In this state, the CPU 51 controls the pump motor 261 shown in FIG. 3 to start driving the circulation pump 26 shown in FIG. 1. This causes white ink to be returned from the printer tank 17W of printer 1A (target printer) to the server tank 6W via the pipe 8.

The CPU 51 acquires the server remaining amount V from the server sensor 71 shown in FIG. 3 (S52). The CPU 51 determines whether the server remaining amount V acquired in the process of S52 has reached the pre-circulation remaining amount Va (see FIG. 4) stored in the process of S22 (S53). If the server remaining amount V is less than the pre-circulation remaining amount Va (S53: NO), the CPU 51 returns the process to the process of S52.

When the server remaining amount V reaches the pre-circulation remaining amount Va (S53: YES, time point T4 shown in FIG. 4), the CPU 51 starts timing the current added time Tc (see FIG. 4) (S54). The current added time Tc is the time stored in the RAM 53 in the processing of S44 or S46, and is the latest added time Tc stored in the RAM 53 at the time of processing S54. After processing S53, the CPU 51 performs processing S53 without stopping the return operation for the printer tank 17W of the target printer. In other words, after the server remaining amount V reaches the pre-circulation remaining amount Va in the return operation started in processing S51, the return operation for the current added time Tc is continued.

The CPU 51 determines whether the current additional time Tc has elapsed (S55). If the current additional time Tc has not elapsed (S55: NO), the CPU 51 repeats the process of S55. If the current additional time Tc has elapsed (S55: YES, time point T5 shown in FIG. 4), the CPU 51 stops the return operation for the printer tank 17W of the target printer (S56). This causes the actual server remaining amount V to increase from the server remaining amount Va to the server remaining amount Ve that corresponds to the current additional time Tc (see FIG. 4).

In the process of S56, for example, the CPU 51 stops driving the pump motor 261 shown in FIG. 3 and stops driving the circulation pump 26 shown in FIG. 1. The CPU 51 controls the solenoid 281 shown in FIG. 3 and closes the circulation valve 28 shown in FIG. 1. This stops the return of white ink from the printer tank 17W of the printer 1A (target printer) to the server tank 6W via the pipe 8. The CPU 51 sets the circulation flag to "1" (S57). The CPU 51 returns the process to the main process shown in FIG. 5.

<Effects of the embodiment>

The CPU 51 acquires the pre-circulation remaining amount Va based on the server sensor 71 (S21). After the process of S21, the CPU 51 performs a supply operation (S23 to S25). After the process of S23, the CPU 51 acquires the post-supply remaining amount Vb based on the server sensor 71 (S31). The CPU 51 calculates the calculated time Tb based on the pre-circulation remaining amount Va based on the server sensor 71 and the post-supply remaining amount Vb based on the server sensor 71 (S33). The CPU 51 performs a return operation based on the calculated time Tb (S51 to S56). According to this, by performing the processes of S23 to S25 and S51 to S56, the white ink circulates between the printer tank 17W and the server tank 6W via the tube 8. In the processes of S51 to S56, the return operation is performed based on the calculated time Tb. Therefore, the liquid supply system 100 contributes to bringing the actual post-circulation remaining amount Ve closer to the actual pre-circulation remaining amount Vs than when the return operation is performed not based on the calculated time Tb.

In the above embodiment, the return operation is performed based on the added time Tc. The added time Tc is a time based on the current calculated time Tb, or a time based on the previous added time Tc and the current calculated time Tb. In either case, the added time Tc is a time based on the calculated time Tb. Therefore, performing the return operation based on the added time Tc can be said to be performing the return operation based on the calculated time Tb.

For example, suppose that at time T4 when the server remaining amount V based on the server sensor 71 becomes the pre-circulation remaining amount Va based on the server sensor 71, there is a difference of a specific amount (Vs-Va) between the server remaining amount V based on the server sensor 71 and the actual pre-circulation remaining amount Vs. In the above embodiment, the CPU 51 performs a return operation in the processing of S51, and performs the return operation for an addition time Tc based on the calculation time Tb after the server remaining amount V based on the server sensor 71 becomes the pre-circulation remaining amount Va based on the server sensor 71. As a result, the difference between the actual post-circulation remaining amount Ve and the actual pre-circulation remaining amount Vs becomes smaller than the specific amount (Vs-Va). Therefore, the liquid supply system 100 further contributes to bringing the actual post-circulation remaining amount Ve closer to the actual pre-circulation remaining amount Vs.

If the ongoing return operation is stopped at time T4 when the server remaining amount V based on the server sensor 71 becomes the pre-circulation remaining amount Va based on the server sensor 71, the time taken from processing S51 to processing S56 may become longer. In the above embodiment, the CPU 51 performs the return operation in processing S51, and performs the return operation for the added time Tc based on the calculated time Tb from time T4 when the server remaining amount V based on the server sensor 71 becomes the pre-circulation remaining amount Va based on the server sensor 71, without stopping the ongoing return operation. Thus, the liquid supply system 100 contributes to preventing the time taken from processing S51 to processing S56 from becoming longer.

In the above embodiment, the server remaining amount V is obtained based on the server sensor 71. The server sensor 71 is less affected by changes in the external environment than the printer sensor 185. Therefore, the liquid supply system 100 contributes to bringing the actual post-circulation remaining amount Ve closer to the actual pre-circulation remaining amount Vs even if the external environment changes, compared to when the printer remaining amount is obtained from the printer sensor 185.

In the above embodiment, in the case of the first circulation operation after the liquid supply device 2 is powered on, or in the case of the first circulation operation after the server tank 6W is replaced (S41: YES), the CPU 51 performs the return operation based on the current calculated time Tb, not on the previous added time Tc. In other words, when there is a relatively high possibility that the calculated time Tb will change significantly from the previous time, the return operation is performed based on the current calculated time Tb. Thus, when there is a relatively high possibility that the calculated time Tb will change significantly from the previous time, the liquid supply system 100 contributes to more reliably bringing the actual post-circulation remaining amount Ve closer to the actual pre-circulation remaining amount Vs.

In the above embodiment, the CPU 51 performs the return operation based on the previous added time Tc when it is the second or subsequent circulation operation after the liquid supply device 2 is powered on, or when it is the second or subsequent circulation operation after the server tank 6W is replaced (S41: NO). The previous added time Tc is a time that has already been used in the previous return operation and has a proven track record. Therefore, when the calculated time Tb is relatively unlikely to change significantly from the previous time, the liquid supply system 100 contributes to more reliably bringing the actual post-circulation remaining amount Ve closer to the actual pre-circulation remaining amount Vs.

In the above embodiment, if the difference between the previous added time Tc and the current calculated time Tb is equal to or greater than a predetermined value (S43: YES), the CPU 51 controls the return operation based on the current calculated time Tb, not on the previous added time Tc (S44, S51, S56). Thus, the liquid supply system 100 contributes to more reliably bringing the actual post-circulation remaining amount Ve closer to the actual pre-circulation remaining amount Vs when there is a relatively high possibility that the flow path configuration has been changed.

In the above embodiment, if the difference between the previous added time Tc and the current calculated time Tb is not equal to or greater than a predetermined value (S43: NO), the CPU 51 controls the return operation based on the previous added time Tc (S46, S51, S56). The previous added time Tc is a time that has already been used in the previous return operation in an unchanged flow path configuration and has a proven track record. Therefore, the liquid supply system 100 contributes to more reliably bringing the actual post-circulation remaining amount Ve closer to the actual pre-circulation remaining amount Vs when there is a relatively high possibility that the flow path configuration has not been changed.

＜Correspondence＞

In the above embodiment, the printer 1 corresponds to the "printer" of the present invention. The printer tank 17W corresponds to the "printer tank" and the "second tank" of the present invention. The white ink corresponds to the "liquid" of the present invention. The liquid supply system 100 corresponds to the "liquid supply system" of the present invention. The server tank 6W corresponds to the "server tank" and the "first tank" of the present invention. The pipe 8 corresponds to the "pipe" of the present invention. The supply pumps 20, 21, the supply valves 22, 23, the circulation pumps 26, 27, and the circulation valves 28, 29 correspond to the "liquid delivery mechanism" of the present invention. The CPU 51 corresponds to the "control unit" and the "computer" of the present invention. The server sensor 71 corresponds to the "server sensor" of the present invention. The printer sensor 185 corresponds to the "printer sensor" of the present invention. The server sensor 71 corresponds to the "remaining amount sensor" of the present invention. The liquid supply device 2 corresponds to the "liquid supply device" of the present invention.

The process of S21 shown in FIG. 6 corresponds to the "first acquisition process" of the present invention. The process of S23 shown in FIG. 6 corresponds to the "first liquid transfer process" of the present invention. The process of S31 shown in FIG. 6 corresponds to the "second acquisition process" of the present invention. The remaining amount Va before circulation corresponds to the "first remaining amount" of the present invention. The remaining amount Vb after supply corresponds to the "second remaining amount" of the present invention. The calculation time Tb corresponds to the "calculation time" of the present invention. The process of S33 shown in FIG. 6 corresponds to the "calculation process" of the present invention. The process of S51 shown in FIG. 7 corresponds to the "second liquid transfer process" of the present invention.

The process of S15 shown in FIG. 5 corresponds to the "circulation process" of the present invention. The process of S41 shown in FIG. 6 or the process of S43 shown in FIG. 6 corresponds to the "judgment process" of the present invention. The previous added time Tc corresponds to the "specific time" of the present invention. The calculated time Tb calculated in the previous process of S33 corresponds to the "first calculated time" of the present invention. The calculated time Tb this time corresponds to the "second calculated time" of the present invention.

<Modification>

The present invention may be modified from the above embodiment. The modifications described below may be combined with each other as appropriate to the extent that no contradictions arise.

In the cyclic processing, the CPU 51 may change the execution order of the supply operation and the return operation. For example, the CPU 51 may start the return operation in the processing of S23, stop the return operation in the processing of S25, start the supply operation in the processing of S51, and stop the supply operation in the processing of S56.

In the above embodiment, when the supply time Ts has elapsed (S24: YES), the CPU 51 stops the supply operation (S25). In contrast, the CPU 51 may stop the supply operation when the cumulative number of rotations of the supply pumps 20, 21 since the supply operation was started in the processing of S23 reaches a predetermined cumulative number, when the amount of change in the server remaining amount V since the supply operation was started in the processing of S23 reaches a predetermined amount of change, etc.

In the above embodiment, when the server remaining amount V reaches the pre-circulation remaining amount Va (S53: YES), the CPU 51 starts counting the additional time Tc (S54). In contrast, the CPU 51 may start counting the additional time Tc when the cumulative number of rotations of the circulation pumps 26, 27 since the return operation was started in the processing of S51 reaches a predetermined cumulative number, when the amount of change in the server remaining amount V since the return operation was started in the processing of S51 reaches a predetermined amount of change, etc. The CPU 51 may control the supply operation and the circulation operation based on the printer remaining amount.

In the above embodiment, when the server remaining amount V reaches the pre-circulation remaining amount Va during the return operation (S53: YES), the CPU 51 starts timing the additional time Tc without stopping the return operation in progress. In contrast, when the server remaining amount V reaches the pre-circulation remaining amount Va during the return operation (S53: YES), the CPU 51 may temporarily stop the return operation in progress. Thereafter, the CPU 51 may resume the return operation and start timing the additional time Tc.

In the above embodiment, the CPU 51 acquires the server remaining amount V based on the server sensor 71, and controls the supply operation and return operation based on the acquired server remaining amount V. In contrast, the CPU 51 may acquire the printer remaining amount based on a signal from the printer sensor 185 in the processes of S21, S31, and S52, for example, and control the supply operation and return operation based on the acquired printer remaining amount.

The resolution of the server sensor 71 may be the same as the resolution of the printer sensor 185, or may be higher than the resolution of the printer sensor 185. The effect of the server sensor 71 on changes in the external environment may be the same as the effect of the printer sensor 185 on changes in the external environment, or may be greater than the effect of the printer sensor 185 on changes in the external environment.

The CPU 51 may omit the process of S41. In this case, the CPU 51 may perform the process of S42 after the process of S33. The CPU 51 may omit the processes of S42 and S43. In this case, if the circulation operation being performed is neither the first circulation operation after the power supply device 2 is turned on nor the first circulation operation after the server tank 6W is replaced (S41: NO), the CPU 51 may perform the process of S46.

The CPU 51 may omit the processes of S41, S42, and S43. In this case, the CPU 41 may perform the process of S44 after the process of S33. The CPU 51 may perform the process of S46 after the process of S33. The CPU 51 may store the added time Tc in the flash memory 44 in the process of S44 or S46. In this case, even if the power of the liquid supply device 2 is turned off, the flash memory 44 holds the previous added time Tc.

In the above embodiment, the CPU 51 may store the previous added time Tc as the added time Tc in the process of S46 without basing it on the current calculated time Tb. The calculation formula for calculating the calculated time Tb is not limited to the above embodiment. The calculation formula may be changed as appropriate based on, for example, the changes in the rotational speeds of the supply pumps 20, 21 and the circulation pumps 26, 27, the relationship between the respective rotational speeds, etc. The CPU 51 may calculate the time from time T3 to time T5 as the added time Tc based on the calculated time Tb.

In the above embodiment, in the process of S41, the CPU 51 determines whether the ongoing circulation operation is the first circulation operation after the liquid supplying device 2 is powered on, and does not have to determine whether it is the first circulation operation after the server tank 6W is replaced. The CPU 51 determines whether the ongoing circulation operation is the first circulation operation after the server tank 6W is replaced, and does not have to determine whether it is the first circulation operation after the liquid supplying device 2 is powered on. The CPU 51 may determine whether the ongoing circulation operation is the first circulation operation after the printer 1 is powered on.

For example, in the first white flow path W1, the liquid supply device 2 may omit one or both of the supply pumps 20, 21. For example, if both of the supply pumps 20, 21 are omitted, the CPU 51 controls one or both of the supply valves 22, 23 to an open state or a closed state. In this way, the CPU 51 may control the supply of white ink from the server tank 6W to each of the printer tanks 17W of the printers 1A, 1B by utilizing the head difference between the server tank 6W and each of the printer tanks 17W of the printers 1A, 1B.

For example, in the first white flow path W1, the liquid supply device 2 may omit one or both of the circulation pumps 26, 27. For example, if both of the circulation pumps 26, 27 are omitted, the CPU 51 controls one or both of the circulation valves 28, 29 to an open state or a closed state. In this way, the CPU 51 may control the return of white ink from the printer tanks 17W of each of the printers 1A and 1B to the server tank 6W by utilizing the head difference between the server tank 6W and the printer tanks 17W of each of the printers 1A and 1B.

For example, in the first white flow path W1, the liquid supply device 2 may omit one or both of the supply valves 22 and 23. In the first white flow path W1, the liquid supply device 2 may omit one or both of the circulation valves 28 and 29. In the first white flow path W1, the liquid supply device 2 may omit one or both of the filters 24 and 25.

The liquid supply device 2 may appropriately change the positional relationship of the supply pump 20, the supply valve 22, and the filter 24 upstream or downstream of the supply flow path, for example, in the pipe 82. Similarly, the liquid supply device 2 may appropriately change the positional relationship of the supply pump 21, the supply valve 23, and the filter 25 upstream or downstream of the supply flow path, for example, in the pipe 83.

The liquid supply device 2 may appropriately change the positional relationship between the circulation pump 26 and the circulation valve 28 upstream or downstream of the circulation flow path, for example, in the pipe 84. Similarly, the liquid supply device 2 may appropriately change the positional relationship between the circulation pump 27 and the circulation valve 29 upstream or downstream of the circulation flow path, for example, in the pipe 85.

One printer 1 may be connected to one liquid supply device 2 via a tube 8, or two or three printers 1 may be connected, or five or more printers 1 may be connected. The liquid supply device 2 may have only one of the multiple server tanks, for example server tank 6W, and the other server tanks may be omitted. In this case, the printer 1 may have only one of the multiple printer tanks, for example printer tank 17W, and the other printer tanks may be omitted. The printer 1 may omit the other heads.

The liquid supply system 100 may supply, for example, a pre-treatment agent, a post-treatment agent, or water as a liquid from the liquid supply device 2 to each of the multiple printers 1. For example, water may be used to humidify the atmosphere inside the printer 1. In this case, each of the multiple printers 1 may be equipped with a humidifier. The humidifier is provided inside the printer 1 and humidifies the atmosphere inside the printer 1. The tube 8 may connect the server tank containing water to the humidifier tank. The main process may be applied to the water flow path instead of or in addition to the first white flow path W1 and the second white flow path W2. Similarly, the main process may be applied to the flow paths of, for example, color ink, pre-treatment agent, or post-treatment agent.

The configuration of the printer 1 is not limited to the above embodiment. For example, in the above embodiment, the printer 1 may be a type other than an inkjet printer, and may be a laser printer, a tape printer, or the like. The multiple heads 14 are not limited to inkjet heads, and may be thermal heads, or the like. The head 14 and other heads may be line heads. For example, even if the printer 1 does not use liquid ink, it may be provided with a humidifier. In this case, the liquid supply system 100 supplies water from the liquid supply device 2 to the humidifier of the printer 1 via the tube 8.

The server sensor 71 may be an optical sensor or an electrode-type level sensor. In this case, the server sensor 71 may detect the remaining amount of server liquid by detecting the height of the liquid level in the server tank 6W. The server sensor 71 may be a pressure sensor. In this case, the server sensor 71 may detect the remaining amount of server liquid by detecting the pressure in the server tank 6W.

The printer sensor 185 may be a weight sensor. In this case, the printer sensor 185 may detect the remaining amount of ink in the printer by detecting the weight of the remaining amount of ink. The printer sensor 185 may be an optical sensor or an electrode-type level sensor. In this case, the printer sensor 185 may detect the remaining amount of ink in the printer by detecting the height of the liquid level in the printer tank 17W.

The number of tubes 8, branching pattern, and other configurations are not limited to the above embodiment. For example, the server tank 6W and the printer tank 17W of one printer 1 may be connected by multiple (e.g., two) unbranched tubes 8. In this case, white ink flows through different tubes 8 during the supply operation and the return operation. For example, tube 84 may be directly connected to the server tank 6W of the printer 1A without being connected to tube 82 at point P2. Tube 85 may be directly connected to the server tank 6W without being connected to tube 84 at point P4. The server tank 6W and the printer tank 17W of one printer 1 may be connected by a single unbranched tube 8. In this case, white ink flows through the same single tube 8 during the supply operation and the return operation.

In the above embodiment, the liquid supply system 100 may change the execution conditions of the supply process and the circulation process. For example, when a user operates the operation unit 186 or the operation unit 57 and inputs an instruction to execute the supply process or the circulation process to the printer 1 or the liquid supply device 2, the CPU 51 may execute the supply process or the circulation process. When a predetermined time arrives, the CPU 51 may execute the circulation process.

The CPU 41 may execute the main processing. In this case, the liquid supply system 100 may omit the CPU 51. The CPU 51 may execute part of the main processing, and the CPU 41 may execute another part of the main processing. The main processing may be executed by a CPU of an external device. The external device is a device other than the printer 1 and the liquid supply device 2, such as a personal computer (PC), a smartphone, etc.

Instead of the CPUs 41 and 51, microcomputers, ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), etc. may be used as processors. The main processing may be distributed among multiple processors. The non-transient storage media, such as the ROMs 42 and 52 and the flash memories 44 and 54, may be storage media capable of retaining information regardless of the period for which the information is stored. The non-transient storage media may not include a temporary storage medium (e.g., a transmitted signal). The control program may be downloaded (i.e., transmitted as a transmission signal) from a server connected to a network not shown, for example, and stored in the ROMs 42 and 52 or the flash memories 44 and 54. In this case, the control program may be stored in a non-transient storage medium, such as a HDD, provided in the server.

1, 1A, 1B, 1C, 1D Printer 2 Liquid supply device 6W Server tank 17W Printer tank 8, 81, 82, 83, 84, 85, 86 Pipes 20, 21 Supply pumps 22, 23 Supply valves 26, 27 Circulation pumps 28, 29 Circulation valves 51 CPU
52 ROM
53 RAM
54 Flash memory 100 Liquid supply system

Claims (11)

A liquid supply system for supplying liquid to a printer tank, which is a tank provided in a printer, comprising:
a pipe connecting the printer tank and a server tank that contains the liquid;
a liquid delivery mechanism for delivering the liquid between the printer tank and the server tank through the pipe;
A control unit and
The control unit is
a first acquisition process for acquiring the remaining amount of the liquid based on a signal from a remaining amount sensor that detects the remaining amount of the liquid in the printer tank or the server tank;
a first liquid sending process for controlling the liquid sending mechanism after the first acquisition process is performed, and sending the liquid from a first tank, which is one of the printer tank and the server tank, to a second tank, which is different from the first tank, of the printer tank and the server tank, via the pipe;
a second acquisition process for acquiring the remaining amount based on a signal from the remaining amount sensor after the first liquid sending process is performed;
a calculation process of calculating a calculation time based on a first remaining amount, which is the remaining amount acquired by the first acquisition process, and a second remaining amount, which is the remaining amount acquired by the second acquisition process;
a second liquid delivery process for controlling the liquid delivery mechanism based on the calculated time calculated by the calculation process, and delivering the liquid from the second tank to the first tank via the pipe. The control unit is
The liquid supply system described in claim 1, characterized in that in the second liquid delivery process, the liquid is delivered from the second tank to the first tank via the pipe, and after the remaining amount indicated by the signal from the remaining amount sensor becomes the first remaining amount, the liquid is delivered from the second tank to the first tank via the pipe for an addition time based on the calculated time. The control unit is
The liquid supply system described in claim 2, characterized in that in the second liquid delivery process, the liquid is delivered from the second tank to the first tank via the pipe, and from the point in time when the remaining amount indicated by the signal from the remaining amount sensor becomes the first remaining amount, the liquid is delivered from the second tank to the first tank via the pipe for the addition time based on the calculated time without stopping the liquid delivery mechanism. a printer sensor for detecting the remaining amount of the liquid in the printer tank;
a server sensor for detecting the remaining amount of the liquid in the server tank,
4. The liquid supply system according to claim 1, wherein the remaining amount sensor is one of the printer sensor and the server sensor, which is less susceptible to changes in the external environment. The control unit is
The calculation process is performed every time a circulation process including the first liquid delivery process and the second liquid delivery process is performed,
performing a determination process of determining whether the circulation process is being performed for the first time since the liquid supply system was powered on, or whether the circulation process is being performed for the first time since the server tank was replaced;
A liquid supply system as described in any one of claims 1 to 3, characterized in that if the judgment process determines that this is the first circulation process since the liquid supply system was powered on, or if it determines that this is the first circulation process since the server tank was replaced, in the second liquid delivery process, the liquid delivery mechanism is controlled based on the calculated time calculated by the current calculation process, and the liquid is delivered from the second tank to the first tank via the pipe. The control unit is
The calculation process is performed every time a circulation process including the first liquid delivery process and the second liquid delivery process is performed,
performing a determination process of determining whether the circulation process is being performed for the first time since the liquid supply system was powered on, or whether the circulation process is being performed for the first time since the server tank was replaced;
A liquid supply system as described in any one of claims 1 to 3, characterized in that if the judgment process determines that this is not the first circulation process since the liquid supply system was powered on, or if the judgment process determines that this is not the first circulation process since the server tank was replaced, in the second liquid delivery process, the liquid delivery mechanism is controlled based on a specific time based on the calculation time calculated by the previous calculation process, and the liquid is delivered from the second tank to the first tank via the pipe. The control unit is
The calculation process is performed every time a circulation process including the first liquid delivery process and the second liquid delivery process is performed,
performing a determination process to determine whether a difference between a specific time based on a first calculation time, which is the calculation time calculated by the previous calculation process, and a second calculation time, which is the calculation time calculated by the current calculation process, is equal to or greater than a predetermined value;
A liquid supply system as described in any one of claims 1 to 3, characterized in that if the judgment process determines that the difference is greater than or equal to the specified value, in the second liquid delivery process, the liquid delivery mechanism is controlled based on the second calculated time to deliver the liquid from the second tank to the first tank via the pipe. The control unit is
The calculation process is performed every time a circulation process including the first liquid delivery process and the second liquid delivery process is performed,
performing a determination process to determine whether a difference between a specific time based on a first calculation time, which is the calculation time calculated by the previous calculation process, and a second calculation time, which is the calculation time calculated by the current calculation process, is equal to or greater than a predetermined value;
A liquid supply system as described in any one of claims 1 to 3, characterized in that if the judgment process determines that the difference is not greater than the specified value, in the second liquid transfer process, the liquid transfer mechanism is controlled based on the specific time to transfer the liquid from the second tank to the first tank via the pipe. A control method for a liquid supply system that supplies liquid to a printer tank, which is a tank provided in a printer, comprising:
The liquid supply system comprises:
a pipe connecting the printer tank and a server tank that contains the liquid;
a liquid delivery mechanism for delivering the liquid between the printer tank and the server tank through the pipe,
The control method includes:
a first acquisition process for acquiring the remaining amount of the liquid based on a signal from a remaining amount sensor that detects the remaining amount of the liquid in the printer tank or the server tank;
a first liquid sending process for controlling the liquid sending mechanism after the first acquisition process is performed, and sending the liquid from a first tank, which is one of the printer tank and the server tank, to a second tank, which is different from the first tank, of the printer tank and the server tank, via the pipe;
a second acquisition process for acquiring the remaining amount based on a signal from the remaining amount sensor after the first liquid sending process is performed;
a calculation process of calculating a calculation time based on a first remaining amount, which is the remaining amount acquired by the first acquisition process, and a second remaining amount, which is the remaining amount acquired by the second acquisition process;
a second liquid delivery process for controlling the liquid delivery mechanism based on the calculated time calculated by the calculation process, and delivering the liquid from the second tank to the first tank via the pipe. A control program for causing a computer of a liquid supply system for supplying liquid to a printer tank, which is a tank provided in a printer, to execute the following processes:
The liquid supply system comprises:
a pipe connecting the printer tank and a server tank that contains the liquid;
a liquid delivery mechanism for delivering the liquid between the printer tank and the server tank through the pipe,
The control program causes the computer to
a first acquisition process for acquiring the remaining amount of the liquid based on a signal from a remaining amount sensor that detects the remaining amount of the liquid in the printer tank or the server tank;
a first liquid sending process for controlling the liquid sending mechanism after the first acquisition process is performed, and sending the liquid from a first tank, which is one of the printer tank and the server tank, to a second tank, which is different from the first tank, of the printer tank and the server tank, via the pipe;
a second acquisition process for acquiring the remaining amount based on a signal from the remaining amount sensor after the first liquid sending process is performed;
a calculation process of calculating a calculation time based on a first remaining amount, which is the remaining amount acquired by the first acquisition process, and a second remaining amount, which is the remaining amount acquired by the second acquisition process;
and a second liquid delivery process for controlling the liquid delivery mechanism based on the calculated time calculated by the calculation process and delivering the liquid from the second tank to the first tank via the pipe. A liquid supplying device that supplies liquid to a printer tank, which is a tank provided in a printer,
a pipe connecting the printer tank and a server tank that contains the liquid;
a liquid delivery mechanism for delivering the liquid between the printer tank and the server tank through the pipe;
A control unit and
The control unit is
a first acquisition process for acquiring the remaining amount of the liquid based on a signal from a remaining amount sensor that detects the remaining amount of the liquid in the printer tank or the server tank;
a first liquid sending process for controlling the liquid sending mechanism after the first acquisition process is performed, and sending the liquid from a first tank, which is one of the printer tank and the server tank, to a second tank, which is different from the first tank, of the printer tank and the server tank, via the pipe;
a second acquisition process for acquiring the remaining amount based on a signal from the remaining amount sensor after the first liquid sending process is performed;
a calculation process of calculating a calculation time based on a first remaining amount, which is the remaining amount acquired by the first acquisition process, and a second remaining amount, which is the remaining amount acquired by the second acquisition process;
a second liquid delivery process for controlling the liquid delivery mechanism based on the calculated time calculated by the calculation process, and delivering the liquid from the second tank to the first tank via the pipe.

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