Printing apparatus and method for controlling the printing apparatus

Abstract

In a printing device that selectively switches between ink-supplying cartridges from among multiple cartridges, the invention prevents ink from solidifying in the ink flow path. [Solution] In the printing apparatus 100, the ejection head 40 ejects ink. The damper 30 supplies ink to the ejection head 40. The supply path R1 supplies ink to the damper 30 from a plurality of cartridges 11. The control unit 81 selectively switches which cartridge 11 supplies ink to the supply path R1 from among the plurality of cartridges 11. If a predetermined period of time has elapsed with any of the plurality of cartridges 11 unusable, the control unit 81 outputs a warning.

Description

Technical Field

[0001] The present disclosure relates to a printing apparatus and a method for controlling the printing apparatus.

Background Art

[0002] There is known a printing apparatus having a function of selectively switching a cartridge that supplies ink from among a plurality of cartridges. For example, Patent Document 1 discloses an ink supply mechanism that detects when the remaining amount of ink in one of a plurality of cartridges reaches zero or near zero and continues to supply ink from the next cartridge. This enables continuous supply of ink to the ink jet head over a long period of time.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a printing apparatus as described above, even if there are cartridges in a state where they cannot be used among a plurality of cartridges, ink can be supplied from other cartridges, so printing can be performed normally. On the other hand, if some cartridges are left unused, there is a risk that the ink will stick in the ink flow path and prevent normal ink flow. Therefore, it is required to prevent the ink from sticking in the ink flow path.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a printing apparatus and a method for controlling the printing apparatus that prevent ink from sticking in an ink flow path in a printing apparatus that selectively switches a cartridge that supplies ink from among a plurality of cartridges. [Means for solving the problem]

[0006] To achieve the above objective, a printing apparatus according to the first aspect of this disclosure includes an ink ejection head, a damper that supplies the ink to the ejection head, a supply path that supplies the ink to the damper from a plurality of cartridges, and a control unit that selectively switches which cartridge supplies the ink to the supply path from among the plurality of cartridges, wherein the control unit outputs a warning if any of the plurality of cartridges remains unusable for a predetermined period of time.

[0007] With the above configuration, in a printing device that selectively switches between ink-supplying cartridges from among multiple cartridges, it is possible to prevent ink from solidifying in the ink flow path.

[0008] The control unit may stop accepting online print requests if any of the plurality of cartridges remain unusable for a predetermined period of time.

[0009] With the above configuration, it is possible to avoid printing becoming impossible midway through if any of the cartridges become unusable.

[0010] The control unit may perform anti-sticking maintenance to prevent the ink from solidifying in the supply path, and in the anti-sticking maintenance, it may supply the ink to the supply path from cartridges other than the cartridge that is unusable among the plurality of cartridges.

[0011] With the above configuration, ink is supplied from cartridges other than those that are unusable during anti-sticking maintenance, thereby more effectively preventing ink from sticking in the ink flow path.

[0012] The control unit may perform the anti-sticking maintenance if it detects that the unusable cartridge has been replaced with a usable cartridge.

[0013] With the above configuration, ink can be allowed to flow into the ink channels that were previously empty due to the cartridge being unusable, thereby more effectively preventing ink from solidifying in the ink channels.

[0014] If the control unit detects that the unusable cartridge has been replaced with the usable cartridge, it may increase the time during the anti-sticking maintenance for supplying ink from the usable cartridge to the supply path, the longer the time that has elapsed since the unusable cartridge became unusable.

[0015] With the above configuration, the longer the time that ink has not flowed due to the cartridge being unusable, the longer the time that ink is supplied from the cartridge during the anti-sticking maintenance, thereby more effectively preventing ink from sticking in the ink flow path.

[0016] If the control unit detects that the remaining ink level of a cartridge supplying ink to the supply path falls below a threshold, it may continue supplying ink to that cartridge while simultaneously starting to supply ink to the supply path from one of the plurality of cartridges whose remaining ink level is equal to or greater than the threshold.

[0017] With the above configuration, even if the ink level in the ink-supplying cartridge falls below a threshold, ink supply to the cartridge continues, thereby reducing waste ink.

[0018] To achieve the above object, a method for controlling a printing apparatus according to a second aspect of the present disclosure is a method for controlling a printing apparatus including a discharge head that discharges ink, a damper that supplies the ink to the discharge head, and a supply path that supplies the ink from a plurality of cartridges to the damper, the method including: a step of selectively switching a cartridge that supplies the ink to the supply path from among the plurality of cartridges; and a step of outputting a warning when a predetermined period has elapsed in a state where any one of the plurality of cartridges is unusable.

Advantages of the Invention

[0019] According to the present disclosure, in a printing apparatus that selectively switches a cartridge that supplies ink from among a plurality of cartridges, it is possible to prevent the ink from sticking in the ink flow path.

Brief Description of the Drawings

[0020] [Figure 1] Functional block diagram schematically showing a configuration example of a printing apparatus according to an embodiment [Figure 2] Block diagram showing a configuration example of a control unit of a printing apparatus according to an embodiment [Figure 3] Flowchart showing the flow of an ink supply process executed by a printing apparatus according to an embodiment [Figure 4] Diagram showing an example in which ink is supplied from one of a plurality of cartridges in a printing apparatus according to an embodiment [Figure 5] Diagram showing an example in which a cartridge from which ink is supplied is switched in a printing apparatus according to an embodiment [Figure 6] Flowchart showing the flow of a warning process executed by a printing apparatus according to an embodiment [Figure 7] Diagram showing an example of a warning screen output by a printing apparatus according to an embodiment [Figure 8] Diagram showing an example of replacing a cartridge in a printing apparatus according to an embodiment [Figure 9]Flowchart showing the process of anti-fixation maintenance executed by the printing apparatus according to the embodiment [Figure 10] Diagram showing an example in which a cartridge to which ink is supplied is switched in the printing apparatus according to the modification

Embodiment for Carrying out the Invention

[0021] Hereinafter, the embodiment will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

[0022] The printing apparatus 100 according to the present embodiment is an apparatus that prints an image on a medium M by an inkjet method. The medium M is a sheet-like member such as paper or fabric. As shown in FIG. 1, the printing apparatus 100 includes an ink supply unit 10, a damper 30, a discharge head 40, a circulation valve 50, a circulation pump 60, a feed mechanism 70, and a control unit 80. Further, the printing apparatus 100 includes a supply path R1 and a circulation path R2 which are ink flow paths. In FIG. 1, the ink flow paths are shown by solid lines, and the signal lines of the control signals by the control unit 80 are shown by broken lines.

[0023] The ink supply unit 10 is an ink supply source that supplies ink to the discharge head 40 via the supply path R1 and the damper 30. The ink supply unit 10 has a plurality of slots 12 and a plurality of supply valves 20. Each of the plurality of slots 12 is an attachment portion to which the cartridge 11 is detachably attached.

[0024] Cartridge 11 is a storage component that contains printing ink. The printing ink is, for example, an ultraviolet-curing ink, and is either CMYK (cyan, magenta, yellow, black) ink or white ink. Alternatively, the printing ink may be a metallic pigment ink such as silver. One cartridge 11 is used by being installed in one slot 12. When one cartridge 11 is installed in one slot 12, and the supply valve 20 corresponding to that cartridge 11, that is, the supply valve 20 located downstream of the slot 12 in which the cartridge 11 is installed, is opened, the ink stored in the cartridge 11 is supplied to the supply path R1.

[0025] More specifically, cartridge 11, although not shown in the illustration, includes an ink pack for storing printing ink and an information storage medium such as an IC (Integrated Circuit). The information storage medium is a non-volatile memory capable of storing information about cartridge 11. The information storage medium stores information such as the current ink level of cartridge 11, its expiration date, and its usage history.

[0026] Each of the multiple supply valves 20 is located downstream of the multiple slots 12 in the supply path R1 and opens and closes the supply path R1. The multiple supply valves 20 correspond one-to-one with the multiple slots 12. Each supply valve 20 switches the supply and stop of ink stored in the cartridge 11 installed in the corresponding slot 12 of the multiple slots 12. When the supply valve 20 is open, ink flows from the corresponding cartridge 11 into the supply path R1, and when the supply valve 20 is closed, ink does not flow from the corresponding cartridge 11 into the supply path R1. The opening and closing operation of each supply valve 20 is controlled by the control unit 80.

[0027] In Figure 1, there are two of each of the multiple cartridges 11, multiple slots 12, and multiple supply valves 20, and the following explanation will also use the case where there are two of each part as an example. However, this is just one example, and the number of each of the multiple cartridges 11, multiple slots 12, and multiple supply valves 20 in a single ink supply unit 10 that supplies ink of the same color may be three or more.

[0028] The supply path R1 is an ink flow path that connects the ink supply unit 10 and the damper 30. The downstream side of the supply path R1 is connected to the damper 30. The upstream side of the supply path R1 branches off at position P1 in the middle of the flow path and connects to multiple slots 12 in the ink supply unit 10. The supply path R1 supplies ink from multiple cartridges 11 installed in the multiple slots 12 to the ejection head 40 via the damper 30.

[0029] More specifically, the supply path R1 has multiple branch paths R11 and R12 and one common path R10. Each of the multiple branch paths R11 and R12 corresponds one-to-one with one of the multiple cartridges 11, and is a flow path that supplies ink from the corresponding cartridge 11 to position P1, which is the confluence point of the multiple branch paths R11 and R12. The common path R10 is a flow path through which the ink supplied from each of the multiple branch paths R11 and R12 passes in common, and supplies the ink supplied from each of the multiple branch paths R11 and R12 to the damper 30 from position P1.

[0030] The damper 30 is attached to the discharge head 40 and is a component that supplies ink supplied from the supply passage R1 to the discharge head 40. As an example, the damper 30 is a head-difference type damper that supplies ink supplied from the cartridge 11 by head difference to the discharge head 40. More specifically, the damper 30 has an ink chamber 31 that stores the ink supplied from the supply passage R1, and supplies the ink stored in the ink chamber 31 to the discharge head 40. The damper 30 supplies ink to the discharge head 40 while adjusting the internal pressure of the discharge head 40 to a predetermined slight negative pressure that is slightly lower than atmospheric pressure. As a result, the damper 30 forms an ink meniscus surface at the tip of each nozzle of the discharge head 40, such that it is a curved surface that is convex upward.

[0031] The ejection head 40 has multiple nozzles and ejects ink stored in the ink chamber 31 of the damper 30 from the multiple nozzles. The ejection head 40 ejects ink using an inkjet method such as a piezo method or a thermal head method. The ejection head 40 is provided so as to be movable in the main scanning direction. The operation of the ejection head 40 is controlled by the control unit 80.

[0032] The circulation path R2 is a flow path that recirculates the ink supplied to the damper 30 back to the supply path R1. The circulation path R2 connects the ink chamber 31 of the damper 30 to a position P2 downstream of position P1, which is the confluence point of multiple branch paths R11 and R12 in the supply path R1. In the damper 30, the ink stored in the ink chamber 31 can flow into the circulation path R2.

[0033] The circulation valve 50 is a valve that opens and closes the circulation path R2. When the circulation valve 50 is open, ink can flow from the ink chamber 31 of the damper 30 into the circulation path R2, and when the circulation valve 50 is closed, ink cannot flow from the ink chamber 31 of the damper 30 into the circulation path R2. The opening and closing operation of the circulation valve 50 is controlled by the control unit 80.

[0034] The circulation pump 60 is located downstream of the circulation valve 50 in the circulation path R2. The circulation pump 60 moves ink from the damper 30 to the supply path R1 by generating a pressure difference. By operating the circulation pump 60 with the circulation valve 50 open, ink flows from the ink chamber 31 of the damper 30 into the circulation path R2. The incoming ink flows through the circulation path R2 in the direction of the solid arrow shown in Figure 1, passes through the circulation valve 50 and the circulation pump 60, and flows into the common path R10 of the supply path R1 at position P2. As a result, the ink in the damper 30 is returned to the supply path R1 and circulates through the supply path R1 and the circulation path R2.

[0035] A filter may be provided between the circulation valve 50 and the circulation pump 60 to filter the ink flowing through the circulation path R2 and remove foreign matter from the ink. In addition, although not shown in the figures, check valves are provided in the supply valve 20, damper 30, circulation valve 50, and circulation pump 60. The check valves prevent the ink from flowing back in the respective designated flow directions.

[0036] This ink circulation process using the circulation path R2 is performed as needed when the printing device 100 is in a state where it can operate normally. In other words, regardless of whether the printing process and the anti-sticking maintenance process described later are in progress, the control unit 81 opens the circulation valve 50 and operates the circulation pump 60 at an appropriate timing to circulate the ink. By performing this circulation process, the flow rate of ink in the supply path R1 increases, making it possible to more effectively prevent ink from sticking in the supply path R1.

[0037] The printing apparatus 100 is equipped with the following components for each ink color, as shown in Figure 1: an ink supply unit 10, a damper 30, an ejection head 40, a circulation valve 50, a circulation pump 60, a supply path R1, and a circulation path R2. The ink colors include, for example, CMYK (cyan, magenta, yellow, black) or white. In other words, Figure 1 shows a configuration for printing on media M using one color of ink. Multiple cartridges 11 containing ink of the same color are installed and used in multiple slots 12 of a single ink supply unit 10.

[0038] Thus, the printing device 100 has a configuration that allows a single ink supply unit 10 to supply ink of the same color from multiple cartridges 11, and it has a function to automatically switch which cartridge 11 supplies ink from among the multiple cartridges 11. This makes it possible to prevent printing from stopping due to running out of ink. Therefore, it is possible to suppress the possibility of printing stopping in the middle of continuous printing, for example, during unattended printing at night. The configuration of the control of such a printing device 100 will be described below.

[0039] The control unit 80 is a unit that comprehensively controls the operation of the printing device 100. As shown in Figure 2, the control unit 80 comprises a control unit 81, a storage unit 82, an operation unit 83, a display unit 84, and a communication unit 85.

[0040] The control unit 81 includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and RTC (Real Time Clock). The CPU is a central processing unit that includes a microprocessor and performs various processes and calculations. In the control unit 81, the CPU reads the control program stored in the ROM and controls the operation of the entire printing device 100 using the RAM as work memory. Specifically, the control unit 81 sends control signals to each of the multiple supply valves 20, discharge heads 40, circulation valves 50, circulation pumps 60, and feeding mechanisms 70 to control the operation of each of these parts. Note that the control unit 81 may also include a dedicated control circuit such as an ASIC (Application Specific Integrated Circuit) instead of a CPU.

[0041] The storage unit 82 is a non-volatile memory such as an HDD (Hard Disk Drive) or SSD (Solid State Drive). The storage unit 82 stores programs and data executed by the control unit 81, as well as data generated by the control unit 81.

[0042] The operation unit 83 and the display unit 84 are the user interface of the printing device 100. The operation unit 83 is equipped with input devices such as physical buttons and a touch panel, receives operation input from the user, and supplies control signals corresponding to the operation input to the control unit 81. The display unit 84 is equipped with a display device such as a liquid crystal display and displays an image according to the image data supplied from the control unit 81. The operation unit 83 and the display unit 84 may be implemented, for example, by a touch screen.

[0043] The communication unit 85 is equipped with a communication interface for wired or wireless communication with external devices. For example, the communication unit 85 communicates with external devices in accordance with well-known communication standards such as LAN (Local Area Network) and USB (Universal Serial Bus). The communication unit 85 acquires image data to be printed from external devices and stores it in the storage unit 82.

[0044] Functionally, the control unit 81 comprises a remaining quantity determination unit 110, a print execution unit 120, a warning output unit 130, and a maintenance execution unit 140. In the control unit 81, the CPU functions by reading a program stored in ROM into RAM, executing that program, and controlling these units.

[0045] The ink level determination unit 110 determines the remaining ink level in each of the multiple cartridges 11. For example, the ink level determination unit 110 determines the remaining ink level based on the amount of ink used for each process performed by the printing device 100. Specifically, the ink level determination unit 110 sets the amount of ink used for each color for each of the multiple processes that the printing device 100 can perform. Then, each time the printing device 100 performs some process, the ink level determination unit 110 determines the remaining ink level by subtracting the amount of ink used for each color specified for the performed process from the amount of ink remaining in the corresponding color cartridge 11 before the process was performed.

[0046] Alternatively, the ink level determination unit 110 may determine the remaining ink level of a cartridge 11 based on its weight. Furthermore, a sensor installed in the ink pack of the cartridge 11 may detect the remaining ink level in the ink pack in real time. In this way, the ink level determination unit 110 determines the remaining usable ink level in each of the multiple cartridges 11 installed in the multiple slots 12.

[0047] The current ink level information for cartridge 11 is stored on an information storage medium installed in cartridge 11. The ink level determination unit 110 can read the current ink level of cartridge 11 from the information storage medium. Furthermore, when the ink level determination unit 110 determines the ink level again, it updates the ink level information stored on the information storage medium with the new ink level information. This allows for accurate determination of the ink level of the changed cartridge 11, even if the cartridge 11 installed in slot 12 is changed.

[0048] The print execution unit 120 performs printing using an inkjet method. The user can input a print command for the desired image data to be printed, for example, by operating the operation unit 83 or remotely via online connection. Once a print command is input by the user, the print execution unit 120 prints the image based on the instructed image data onto the media M.

[0049] More specifically, the print execution unit 120 drives a head movement mechanism (not shown) to move the ejection head 40 in the main scanning direction, and ejects ink from the ejection head 40 at timings based on the image data, thereby executing one line of printing. The head movement mechanism, although not shown in the illustration, is a mechanism that moves the ejection head 40 along the main scanning direction according to the control of the print execution unit 120. Subsequently, the print execution unit 120 drives a feed mechanism 70 to move the media M by a predetermined distance in the sub-scanning direction. The feed mechanism 70 is a mechanism that moves the media M along the sub-scanning direction according to the control of the print execution unit 120. The print execution unit 120 prints an image based on the image data onto the media M by repeating this process of printing one line and moving the media M.

[0050] In this printing process, the printing execution unit 120 performs an ink supply process in which it supplies the ink necessary for printing from multiple cartridges 11 attached to multiple slots 12 to the damper 30 and the ejection head 40 via the supply path R1. This ink supply process will be explained with reference to Figure 3.

[0051] In the ink supply process shown in Figure 3, the print execution unit 120 selects a cartridge 11 to supply ink to the supply path R1 from among the multiple cartridges 11 installed in the multiple slots 12, based on predetermined selection conditions (step S11). As an example, the print execution unit 120 refers to the remaining ink levels of each cartridge 11 determined by the remaining ink level determination unit 110 and prioritizes selecting the cartridge 11 with the lowest remaining ink level among the cartridges 11.

[0052] Alternatively, the printing execution unit 120 may prioritize selecting a cartridge 11 by referring to the expiration date or usage history of each cartridge 11. For example, the printing execution unit 120 may prioritize selecting the cartridge 11 with the closest expiration date, or the cartridge 11 with the most frequent past usage, or the cartridge 11 with the closest last usage date.

[0053] Here, information such as the expiration date and usage history of cartridge 11 is stored, for example, on an information storage medium installed in cartridge 11. The print execution unit 120 reads this information from the information storage medium of cartridge 11 installed in slot 12. After printing, the print execution unit 120 updates the usage history information of the cartridge 11 used for printing, which is stored on the information storage medium.

[0054] When cartridge 11 is selected, the print execution unit 120 supplies ink from the selected cartridge 11 (step S12). Specifically, the print execution unit 120 opens the supply valve 20 corresponding to the cartridge 11 selected in step S11 from among the multiple supply valves 20. Then, the print execution unit 120 closes the other supply valves 20 that do not correspond to the selected cartridge 11. As a result, the print execution unit 120 starts supplying ink only from the selected cartridge 11 among the multiple cartridges 11.

[0055] For example, Figure 4 shows an example where cartridge 1 and cartridge 2, which contain two cartridges 11 of the same color ink, are installed in slot 1 and slot 2, respectively, of the two slots 12 of the ink supply unit 10. When the print execution unit 120 selects cartridge 1, it opens the supply valve 20 located downstream of cartridge 1 and closes the supply valve 20 located downstream of cartridge 2. As a result, the print execution unit 120 supplies ink to the supply path R1 from only cartridge 1 of the two cartridges 11. At this time, cartridge 2 remains unused, even if it is new and in usable condition.

[0056] Returning to Figure 3, when ink supply begins from the selected cartridge 11, the printing execution unit 120 determines whether the switching condition for the cartridge 11 supplying ink to the supply path R1 has been met (step S13). Here, the switching condition is met, for example, when the remaining ink level of the cartridge 11 currently supplying ink falls below the threshold TH1, or when the expiration date set for cartridge 11 has passed. The threshold TH1 is pre-set to a value greater than 0.

[0057] The printing execution unit 120 refers to the remaining ink level determined by the remaining ink level determination unit 110 and determines whether the ink level of the cartridge 11 currently supplying ink has decreased and fallen below the threshold TH1. The printing execution unit 120 also reads the expiration date information from the information storage medium installed in the cartridge 11 currently supplying ink and determines whether the expiration date has passed.

[0058] If the switching condition is not met (step S13; YES), the print execution unit 120 stops processing at step S13 and waits until the switching condition is met. If printing is completed before the switching condition is met, the print execution unit 120 terminates the ink supply process shown in Figure 3 without switching cartridge 11.

[0059] In response to this, if the switching condition is met (step S13; YES), the printing execution unit 120 switches the ink supply cartridge 11 (step S14). Specifically, the printing execution unit 120 opens the supply valves 20 other than the supply valve 20 that is currently open, and closes the supply valve 20 that is currently open. As a result, the printing execution unit 120 supplies ink to the supply path R1 from the other cartridge 11.

[0060] As an example, Figure 5 shows a situation where, while ink is being supplied from cartridge 1 as shown in Figure 4, the switching condition is met due to a decrease in the ink level in cartridge 1 or the expiration of its use-by date. In this case, the printing execution unit 120 opens the supply valve 20 located downstream of cartridge 2 and closes the supply valve 20 located downstream of cartridge 1. As a result, the printing execution unit 120 stops the ink supply from cartridge 1 and supplies ink from cartridge 2 to the supply path R1. In this way, even if ink can no longer be supplied from cartridge 1 due to a decrease in the ink level or the expiration of its use-by date, the ink supply can be continued by switching the ink source to cartridge 2. This prevents the printing from stopping midway.

[0061] Returning to Figure 2, the warning output unit 130 outputs a warning if any of the multiple cartridges 11 remain unusable for a predetermined period of time. Here, "unusable" means that it is impossible to supply ink normally from the cartridge 11. Specifically, a cartridge 11 becomes unusable when the ink level in the cartridge 11 falls below the threshold TH2, or when the expiration date set for the cartridge 11 has passed.

[0062] As described above, the printing device 100 has a function to selectively switch which cartridge 11 supplies ink from among the multiple cartridges 11. Therefore, even if some of the multiple cartridges 11 are unusable, ink can be supplied from the other cartridges 11, and printing can be performed normally. For this reason, the warning output unit 130 does not output a warning until a predetermined period of time has elapsed since any of the cartridges 11 became unusable.

[0063] On the other hand, as ink flows through the supply path R1, components of the ink separate, settle, and adhere to the inner wall of the supply path R1. If the ink adhering to the inner wall of the supply path R1 is left for a long period of time, it hardens and causes ink to stagnate, hindering the smooth flow of ink within the supply path R1. Therefore, if some cartridges 11 are left without ink supply, it causes ink to harden in the branch path R11 or branch path R12 corresponding to those cartridges 11, leading to deterioration or failure of the printing device 100. To prevent such ink hardening, the warning output unit 130 outputs a warning when a predetermined period of time has elapsed in an unusable state, notifying the user that there are cartridges 11 that have been left unusable.

[0064] Here, the predetermined period is a period of a fixed length, such as one week, several days, or several weeks. The predetermined period is set to be shorter than the time required for the ink to harden, in order to prevent the ink from hardening.

[0065] Furthermore, the threshold TH2 is pre-set to, for example, 0 or a value greater than 0. Note that the threshold TH2 (second threshold) may be the same value as the threshold TH1 (first threshold) used for the switching conditions of the cartridge 11 in the printing process by the printing execution unit 120, or it may be a different value. For example, since the amount of ink required for the anti-sticking maintenance described later is less than the amount of ink used in normal printing, the threshold TH2 can be set to a value smaller than the threshold TH1, taking this into consideration.

[0066] The warning process performed by the warning output unit 130 will be explained in detail with reference to Figure 6. The warning output unit 130 repeatedly performs the warning process shown in Figure 6 while the printing device 100 is in a state where it can operate normally. In other words, the warning output unit 130 performs the warning process shown in Figure 6 both when the printing execution unit 120 is performing the printing process, including the ink supply process shown in Figure 3, and when it is not performing the printing process.

[0067] In the warning process shown in Figure 6, the warning output unit 130 determines whether any of the cartridges 11 installed in the multiple slots 12 have become unusable (step S21). Specifically, the warning output unit 130 determines whether any of the multiple cartridges 11 have an ink level that has fallen below the threshold TH2 or have expired.

[0068] If all cartridges 11 are usable (step S21; NO), the warning output unit 130 stops processing at step S21. On the other hand, if any of the cartridges 11 become unusable (step S21; YES), the warning output unit 130 starts measuring time (step S22). The warning output unit 130 then determines whether a predetermined period has elapsed with any of the cartridges 11 in an unusable state (step S23). At this time, the warning output unit 130 stores information about the branch line R11 or branch line R12 located downstream of the slot 12 in which the unusable cartridge 11 is installed in the storage unit 82.

[0069] If a predetermined period of time elapses while any of the cartridges 11 are unusable (step S23; YES), the warning output unit 130 outputs a warning (step S24). Then, the print execution unit 120 stops accepting online print requests (step S25).

[0070] In contrast, if the unusable state of any cartridge 11 is resolved before a predetermined period has elapsed since it became unusable (step S23; NO), the warning output unit 130 skips steps S24 and S25. This corresponds to the case where any cartridge 11 becomes unusable and is replaced with a usable cartridge 11 (for example, a cartridge 11 with sufficient ink remaining) before a predetermined period has elapsed since it became unusable.

[0071] In step S24, the warning output unit 130 displays a warning screen, for example, as shown in Figure 7, on the display unit 84. Here, the warning screen shown in Figure 7 is an example of a situation where a predetermined period of time has elapsed since cartridge 1 became unusable due to ink depletion, as shown in Figure 5. Specifically, on the warning screen, the warning output unit 130 notifies the user that cartridge 1 installed in slot 1 is unusable and that the unusable cartridge 1 should be replaced with another usable cartridge 11.

[0072] Furthermore, the warning output unit 130 notifies the user on the warning screen that it will stop accepting online print requests. At the same time, the print execution unit 120 stops accepting online print requests. Here, online printing is printing performed according to a print instruction received from an external device via the communication unit 85. The external device is, for example, a personal computer or tablet terminal operated by the user.

[0073] When online printing is stopped, the print execution unit 120 will not execute printing according to the print instruction even if it receives a print instruction from an external device. In this case, even if some cartridges 11 are unusable, printing itself is possible if other cartridges 11 are usable, but if other cartridges 11 also become unusable, printing will become impossible to complete midway. With online printing, it is difficult for the user to directly check the printing device 100, so the possibility of printing becoming impossible midway is relatively higher compared to printing when the user directly operates the printing device 100. Considering this, stopping online printing can prevent printing from becoming impossible midway.

[0074] Furthermore, the warning output unit 130 may output warnings not only by displaying a warning screen on the display unit 84, but also by outputting warnings by voice from a speaker. Alternatively, the warning output unit 130 may communicate with an external device via the communication unit 85 and output warnings through the display unit or speaker of the external device.

[0075] When a user sees such a warning, they will replace the unusable cartridge 11 as instructed. For example, the user may prepare a new, unused cartridge 11 and replace the unusable cartridge 11 with the new one. In this case, the user will remove the unusable cartridge 11 from slot 12 and install the new, unused cartridge 11 into that slot 12. Alternatively, as another example of cartridge replacement, if the user does not have a new, unused cartridge 11 on hand, they may swap the unusable cartridge 11 with a usable cartridge 11 already installed in another slot 12. Such a swap also prevents the unusable cartridge 11 from remaining installed in the same slot 12 indefinitely.

[0076] Specifically, Figure 8 shows an example of when cartridge 11 is replaced. Figure 8 shows an example of when cartridge 1 and cartridge 2 are replaced after a predetermined period of time has elapsed since cartridge 1 became unusable, as shown in Figure 5. Specifically, the user removes the unusable cartridge 1 and the usable cartridge 2 from slots 1 and 2, respectively, installs cartridge 1 into slot 2, and installs cartridge 2 into slot 1. As a result, the usable cartridge 2 is installed in slot 1 where the unusable cartridge 1 was installed, so ink is supplied to the branch line R11 downstream of slot 1. Therefore, it is possible to prevent the ink from remaining unsupplied in the branch line R11 downstream of slot 1 and consequently solidifying.

[0077] After cartridge 1 and cartridge 2 are swapped in this way, ink can no longer be supplied from cartridge 1, which is newly installed in slot 2. In this case, the warning output unit 130 determines in step S21 of the warning process shown in Figure 6 that cartridge 1, which is newly installed in slot 2, has become unusable, and executes the processes from step S22 onwards. Specifically, after outputting a warning, the warning output unit 130 resumes measuring time when cartridges 1 and 2 are swapped. Then, after a predetermined period of time has elapsed with cartridge 1 installed in slot 2 being unusable, the warning output unit 130 outputs another warning and stops accepting online print requests. By repeatedly outputting warnings and stopping online print requests in this way, the system prompts the user to replace or swap cartridge 1.

[0078] Returning to Figure 2, the maintenance execution unit 140 performs maintenance to maintain the printing device 100 in a state where it can operate normally. Specifically, the maintenance execution unit 140 performs adhesion prevention maintenance. Here, adhesion prevention maintenance is maintenance to prevent ink from solidifying in the supply path R1, and is a process of supplying ink to the supply path R1 as a separate process from the printing process. As mentioned above, if ink adhering to the inner wall of the supply path R1 is left for a long period of time, it may solidify and hinder the smooth flow of ink through the supply path R1. To prevent such ink solidification, the maintenance execution unit 140 performs adhesion prevention maintenance.

[0079] When performing anti-sticking maintenance, the maintenance execution unit 140 supplies ink to the supply path R1 from one of the multiple cartridges 11 installed in the multiple slots 12. More specifically, the maintenance execution unit 140 opens the supply valve 20 corresponding to one of the cartridges 11 for a predetermined time (for example, a short time such as a few seconds), and discharges a small amount of ink from that cartridge 11 into the supply path R1. By supplying ink to the supply path R1 in this way as a process independent of the printing process, the maintenance execution unit 140 avoids the ink from not flowing into the supply path R1 for a long period of time, thereby preventing the ink components from solidifying within the supply path R1.

[0080] The flow of the anti-sticking maintenance process will be explained in detail with reference to Figure 9. The maintenance execution unit 140 performs the anti-sticking maintenance process shown in Figure 9 as needed while the printing device 100 is in a state where it can operate normally.

[0081] In the anti-sticking maintenance process shown in Figure 9, the maintenance execution unit 140 determines whether or not the timing for anti-sticking maintenance has arrived (step S31). The timing for anti-sticking maintenance is a timing that occurs regularly, for example, once a week. The time interval of this regular timing is set in advance to a length that can prevent ink from sticking. This time interval may be the same length as the predetermined period for the warning output unit 130 to output a warning, or it may be different. If the timing for anti-sticking maintenance has not arrived (step S31; NO), the maintenance execution unit 140 stops the process at step S31.

[0082] When it is time for anti-sticking maintenance (step S31; YES), the maintenance execution unit 140 selects a cartridge 11 to supply ink during the anti-sticking maintenance (step S32). First, if there is a cartridge 11 among the multiple cartridges 11 that is unusable, the maintenance execution unit 140 excludes that cartridge 11 from the selection candidates because it cannot supply the ink necessary for maintenance. Then, from among the multiple cartridges 11, the maintenance execution unit 140 selects a cartridge 11 that will supply ink to the supply path R1 during the anti-sticking maintenance from at least one cartridge 11 other than the unusable cartridge 11.

[0083] More specifically, the maintenance execution unit 140 selects a cartridge 11 based on predetermined selection criteria. These criteria may include, for example, the remaining ink level, expiration date, and usage history of the cartridge 11. As an example, the maintenance execution unit 140 may select the cartridge 11 with the least past usage frequency, or the cartridge 11 with the oldest last usage date. The maintenance execution unit 140 reads this information from the information storage medium of each cartridge 11 installed in each slot 12, and selects the cartridge 11 that will supply ink for the anti-sticking maintenance from among at least one cartridge 11 that is in a usable condition.

[0084] When cartridge 11 is selected, the maintenance execution unit 140 supplies ink from the selected cartridge 11 (step S33). Specifically, the maintenance execution unit 140 opens the supply valve 20 located downstream of the slot 12 in which the selected cartridge 11 is installed, and supplies ink from cartridge 11 to the supply path R1. Then, the maintenance execution unit 140 closes the supply valve 20 after a predetermined time has elapsed since opening it. By supplying ink to the supply path R1 periodically in this way, it is possible to avoid a state in which ink does not flow in the supply path R1 for a long period of time. Therefore, it is possible to prevent ink from solidifying in the supply path R1.

[0085] As described above, the printing apparatus 100 according to this embodiment is a device that selectively switches between a plurality of cartridges 11 that supply ink to the ejection head 40 via a supply path R1, and outputs a warning if any of the plurality of cartridges 11 remain unusable for a predetermined period of time. By prompting the user to replace or swap the cartridge 11 with such a warning, it is possible to prevent ink from solidifying in the supply path R1.

[0086] In particular, in a printing device 100 that has a function to selectively switch which cartridge 11 supplies ink from among several cartridges 11, even if some cartridges 11 are unusable, ink can still be supplied from other cartridges 11, allowing normal printing to continue. As a result, some cartridges 11 are likely to be left unusable. In contrast, the printing device 100 according to this embodiment outputs a warning as described above, thus preventing cartridges 11 from being left unused for extended periods. As a result, ink buildup in the supply path R1 can be prevented, leading to the prevention of deterioration and malfunction of the printing device 100.

[0087] Although embodiments have been described above, various modifications and applications are possible. It is arbitrary which parts of the configuration, function, and operation described in the above embodiments are adopted. Furthermore, additional configurations, functions, and operations may be adopted in addition to those described above. Also, the configurations, functions, and operations described in the above embodiments can be freely combined.

[0088] (Variation 1) In the above embodiment, the maintenance execution unit 140 performed sticking prevention maintenance at regularly occurring intervals. However, in addition to or instead of this, the maintenance execution unit 140 may also perform sticking prevention maintenance when it detects that a cartridge 11 that is unusable has been replaced with a cartridge 11 that is usable. When a cartridge 11 is unusable, ink cannot be supplied from that cartridge 11 to the supply path R1, making it more prone to ink sticking. In particular, ink is more likely to stick to the branch path R11 or branch path R12 corresponding to the unusable cartridge 11 because ink is not supplied to that cartridge 11 while it is unusable. To avoid this, the maintenance execution unit 140 may also perform sticking prevention maintenance when it detects that a cartridge 11 that is unusable has been replaced with another cartridge 11 that is usable.

[0089] Specifically, the maintenance execution unit 140 reads the ink level and expiration date information from the information storage medium installed in the cartridges 11 installed in each slot 12, and determines whether each cartridge 11 is in a usable state. The maintenance execution unit 140 then detects the replacement of a cartridge 11 if an unusable cartridge 11 is removed from any of the slots 12 and another usable cartridge 11 is newly installed in that slot 12. Upon detecting such a cartridge replacement, the maintenance execution unit 140 causes ink to be supplied from the newly installed cartridge 11 to the supply path R1. This allows ink to flow to branch paths R11 or R12, which had not been receiving ink while the cartridge 11 was unusable.

[0090] Furthermore, if the maintenance execution unit 140 detects that a cartridge 11 that is unusable has been replaced with a cartridge 11 that is usable, the longer the time elapsed since the unusable cartridge 11 became unusable, the longer the time it may spend supplying ink from the usable cartridge 11 to the supply path R1 during the sticking prevention maintenance. Specifically, the longer the time that the cartridge 11 has been unusable, the greater the degree of ink sticking in the supply path R1, and it is assumed that a large amount of ink will need to be flowed during the sticking prevention maintenance to prevent ink sticking.

[0091] Therefore, the maintenance execution unit 140 measures the elapsed time from when one of the multiple cartridges 11 installed in the multiple slots 12 becomes unusable until that cartridge 11 is replaced with a usable cartridge 11. The longer the measured elapsed time, the longer the time the maintenance execution unit 140 spends opening and closing the supply valve 20 corresponding to the replaced cartridge 11 during the anti-sticking maintenance. This allows the maintenance execution unit 140 to extend the time for which ink is supplied from the replaced cartridge 11 to the supply path R1, and to allow a larger amount of ink to flow from the replaced cartridge 11 into the supply path R1.

[0092] (Modification 2) In the above embodiment, if the switching condition for cartridge 11 is met in step S13, the printing execution unit 120 switches the cartridge 11 supplied with ink in step S14 by opening the supply valves 20 other than the currently open supply valve 20 and closing the currently open supply valve 20. However, if the switching condition is met in step S13 because the ink level falls below the threshold TH1, the printing execution unit 120 may simultaneously open the supply valves 20 of both the cartridge 11 before switching and the cartridge 11 after switching in step S14. In other words, if the ink level of a cartridge 11 supplying ink to the supply path R1 falls below the threshold TH1, the printing execution unit 120 may continue supplying ink to that cartridge 11 while starting to supply ink to the supply path R1 from one of the multiple cartridges 11 whose ink level is equal to or greater than the threshold TH1.

[0093] Specifically, Figure 10 shows the case where, while ink is being supplied from cartridge 1 as shown in Figure 4, the switching condition is met when the ink level in cartridge 1 falls below the threshold TH1. In this case, the printing execution unit 120 starts supplying ink to cartridge 2 by opening the supply valve 20 located downstream of the slot 2 in which cartridge 2 is installed. At this time, the printing execution unit 120 keeps the supply valve 20 located downstream of the slot 1 in which cartridge 1 is installed open without closing it. This allows ink to continue to be supplied from cartridge 1 even though the ink level is low. Subsequently, when the ink level in cartridge 1 drops to 0, the printing device 100 closes the supply valve 20 corresponding to cartridge 1.

[0094] In this way, when the ink level in cartridge 1 falls below the threshold TH1, ink is supplied simultaneously from both cartridges 1 and 2, allowing the ink in cartridge 1 to be used up completely. More specifically, as the ink level in cartridge 1 decreases, the pressure of the ink supply from cartridge 1 decreases, making it difficult for cartridge 1 alone to supply a sufficient amount of ink per unit time. In contrast, by supplying ink together with cartridge 2, which has a sufficient amount of ink remaining, it becomes possible to supply a sufficient amount of ink per unit time while using up the remaining ink in cartridge 1 completely. This leads to a reduction in waste ink.

[0095] This disclosure allows for various embodiments and modifications without departing from the broad spirit and scope of this disclosure. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of this disclosure. In other words, the scope of this disclosure is indicated by the claims, not by the embodiments. Various modifications made within the scope of the claims and the equivalent significance of the disclosure are considered to be within the scope of this disclosure. [Explanation of Symbols]

[0096] 10 Ink supply unit 11 cartridges 12 slots 20 Supply valves 30 dampers 31 Ink Room 40 Discharge heads 50 Circulation valve 60 Circulation pump 70 Feed mechanism 80 Control Unit 81 Control Unit 82 Memory section 83 Operation section 84 Display section 85 Communications Department 100 Printing equipment 110 Remaining amount determination unit 120 Print execution unit 130 Warning output section 140 Maintenance Execution Unit M Media R1 supply path R10 common road Route 11, Route 12 Junction R2 circulation path

Claims

1. The ejection head that ejects ink, A damper that supplies the ink to the discharge head, A supply path that supplies the ink from multiple cartridges to the damper, A control unit that selectively switches the cartridge that supplies the ink to the supply path from among the plurality of cartridges, Equipped with, The control unit outputs a warning if any of the plurality of cartridges remains unusable for a predetermined period of time. Printing device.

2. The control unit stops accepting online print requests if any of the plurality of cartridges remain unusable for a predetermined period of time. The printing apparatus according to claim 1.

3. The control unit, Perform anti-sticking maintenance to prevent the ink from solidifying in the supply path. In the aforementioned anti-sticking maintenance, the ink is supplied to the supply path from one of the plurality of cartridges, excluding the cartridge that is in an unusable state. The printing apparatus according to claim 1 or 2.

4. When the control unit detects that the unusable cartridge has been replaced with a usable cartridge, it performs the anti-sticking maintenance. The printing apparatus according to claim 3.

5. When the control unit detects that the unusable cartridge has been replaced with the usable cartridge, it increases the time during the anti-sticking maintenance for supplying ink from the usable cartridge to the supply path, the longer the time that has elapsed since the unusable cartridge became unusable. The printing apparatus according to claim 4.

6. When the ink level of a cartridge supplying ink to the supply path falls below a threshold, the control unit continues to supply ink to that cartridge while simultaneously starting to supply ink to the supply path from one of the plurality of cartridges whose ink level is equal to or greater than the threshold. The printing apparatus according to claim 1 or 2.

7. The ejection head that ejects ink, A damper that supplies the ink to the discharge head, A supply path that supplies the ink from multiple cartridges to the damper, A control method for a printing apparatus comprising: A step of selectively switching the cartridge that supplies the ink to the supply path from among the plurality of cartridges, The step of outputting a warning if any of the aforementioned multiple cartridges remain unusable for a predetermined period of time, A method for controlling a printing apparatus, including the following:

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