Printing apparatus and maintenance method for the printing apparatus

Abstract

In a printing device that selectively switches between ink cartridges from among multiple cartridges, maintenance is performed at a low cost to reliably prevent ink from solidifying in the supply 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 the cartridge 11 that supplies ink to the supply path R1 from among the plurality of cartridges 11. If there is a cartridge 11 among the plurality of cartridges 11 that is capable of supplying ink but has been left unused for a predetermined period of time or longer, the control unit 80 performs an anti-sticking maintenance to prevent ink from sticking in the supply path R1 by supplying ink from the unused cartridge 11 to the supply path R1.

Description

Technical Field

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

Background Art

[0002] There is known a printing apparatus having a function of selectively switching a cartridge that supplies ink from 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 makes it possible to continuously supply ink to the inkjet 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, in order to maintain print quality, it is necessary to periodically perform maintenance on the ink supply path from the cartridge to the head. During maintenance, ink is supplied from the cartridge to the supply path and ejected from the head. This can remove deposits of ink components in the supply path with the supplied ink and prevent the ink from sticking in the supply path.

[0005] When performing maintenance on the supply path in the printing apparatus described in Patent Document 1, ink will be supplied from the cartridge currently selected as the ink source. Therefore, in the printing apparatus described in Patent Document 1, during maintenance, ink will not be supplied from cartridges that are not currently selected as the ink source. As a result, there is a risk that the removal of sediment and other contaminants from the ink supply path from those cartridges will be insufficient, and ink solidification may not be prevented. It is also conceivable to perform maintenance on the supply path by supplying ink from all cartridges, but this would increase the amount of ink used for maintenance, thus increasing the maintenance cost.

[0006] This invention has been made in view of the above circumstances, and aims to provide a printing apparatus that selectively switches the cartridge supplying ink from among a plurality of cartridges, and that can perform maintenance to reliably prevent ink from solidifying in the supply path at low cost, as well as a method for maintaining the printing apparatus. [Means for solving the problem]

[0007] To achieve the above objectives, the printing apparatus relating to the first aspect of this disclosure is: 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, if there is a cartridge among the plurality of cartridges that is capable of supplying ink but has been left unused for a predetermined period of time or longer, performs ink retention maintenance to prevent ink from solidifying in the supply path by supplying ink from the unused cartridge to the supply path.

[0008] With the above configuration, the control unit only supplies ink from an unused cartridge to the supply path to perform maintenance to prevent ink from solidifying if such a cartridge is present. This allows for low-cost maintenance that reliably prevents ink from solidifying in the supply path.

[0009] The supply path includes a common path shared by the plurality of cartridges, and a plurality of branch paths that branch off from the common path and connect to each cartridge. The control unit may increase the amount of ink supplied from the neglected cartridge during the anti-sticking maintenance as the path length of the branch line connected to the neglected cartridge increases.

[0010] With the above configuration, it becomes possible to perform anti-sticking maintenance by flowing an appropriate amount of ink into the supply line based on the length of the branch line.

[0011] The control unit may increase the amount of ink supplied from the unused cartridge during the anti-sticking maintenance as the period of time the unused cartridge has been left unused increases.

[0012] With the above configuration, it becomes possible to perform anti-sticking maintenance by flowing an appropriate amount of ink into the supply line based on the period of inactivity.

[0013] Each of the aforementioned multiple cartridges is fitted with an information storage medium that stores information about the ink in the cartridge. The control unit may identify the neglected cartridge based on the information stored in the information storage medium.

[0014] With the above configuration, it is possible to easily identify the cartridge that has been left unused among multiple cartridges.

[0015] To achieve the above objective, the maintenance method for a printing apparatus relating to the second aspect of this disclosure is: The ejection head that ejects ink, A damper that supplies the ink to the ejection head, A supply path that supplies the ink from a plurality of cartridges to the damper, A control unit that selectively switches a cartridge that supplies the ink to the supply path from among the plurality of cartridges, A maintenance method for a printing apparatus including: Determining whether there is a dormant cartridge that can supply ink and has been left unused for a predetermined period or more among the plurality of cartridges, When there is the dormant cartridge, performing anti-fixation maintenance for preventing ink from sticking in the supply path by causing the dormant cartridge to supply ink to the supply path.

Advantages of the Invention

[0016] According to the present disclosure, in a printing apparatus that selectively switches a cartridge that supplies ink from among a plurality of cartridges, maintenance for reliably preventing ink from sticking in the supply path can be performed at low cost.

Brief Description of the Drawings

[0017] [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 anti-fixation maintenance processing executed by a printing apparatus according to an embodiment [Figure 4] Diagram showing a configuration example of a table defining the relationship between a branch path and the ink supply time [Figure 5] Diagram showing a configuration example of a table defining the relationship between a branch path and the opening degree of a supply valve [Figure 6] Functional block diagram schematically showing a configuration example of a printing apparatus according to an embodiment

Embodiments of the Invention

[0018] The embodiments will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

[0019] The printing apparatus 100 according to this embodiment is a device that prints an image onto media M using an inkjet method. Media M is a sheet-like material such as paper or cloth. As shown in Figure 1, the printing apparatus 100 includes an ink supply unit 10, a damper 30, an ejection head 40, a circulation valve 50, a circulation pump 60, a feeding mechanism 70, and a control unit 80. The printing apparatus 100 also includes an ink flow path R1 and a circulation path R2. In Figure 1, the ink flow path is shown by a solid line, and the signal line of the control signal from the control unit 80 is shown by a dashed line.

[0020] The ink supply unit 10 is an ink supply source that supplies ink to the ejection head 40 via the supply path R1 and the damper 30. The ink supply unit 10 has three slots 12A, 12B, and 12C, and three supply valves 20A, 20B, and 20C provided corresponding to these slots. Each of the slots 12A, 12B, and 12C is a mounting part into which cartridges 11A, 11B, and 11C are detachably attached. In the following description, slots 12A, 12B, and 12C will also be referred to as slot 12 if they are not distinguished. Similarly, the supply valves 20A, 20B, and 20C and cartridges 11A, 11B, and 11C will also be referred to as supply valve 20 and cartridge 11.

[0021] 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. Specifically, cartridges 11A, 11B, and 11C are used by being installed in slots 12A, 12B, and 12C, respectively. 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 that cartridge 11 is supplied to the supply path R1.

[0022] More specifically, each of the cartridges 11A, 11B, and 11C includes an ink pack for storing printing ink and an information storage medium 13A, 13B, and 13C such as an IC (Integrated Circuit). In the following description, when the information storage mediums 13A, 13B, and 13C are not distinguished, they will also be referred to as information storage medium 13. Information storage medium 13 is a non-volatile memory capable of storing information related to cartridge 11. For example, information storage medium 13 stores information related to cartridge 11, such as the remaining ink level, expiration date, and usage history.

[0023] 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.

[0024] In Figure 1, there are three 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 three 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 two or more.

[0025] 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.

[0026] More specifically, the supply path R1 has three branch paths R11A, R11B, and R11C, and one common path R10. Each of the branch paths R11A, R11B, and R11C is provided in a one-to-one correspondence with each of the cartridges 11A, 11B, and 11C. Branch path R11A is a flow path that supplies ink supplied from cartridge 11A to position P1, which is the junction point with the other branch paths R11B and R11C. Branch path R11B is a flow path that supplies ink supplied from cartridge 11B to position P1, which is the junction point with the other branch paths R11A and R11C. Branch path R11C is a flow path that supplies ink supplied from cartridge 11C to position P1, which is the junction point with the other branch paths R11A and R11B. As is clear from Figure 1, the length of the branch paths increases in the order of branch path R11A, branch path R11B, and branch path R11C. Furthermore, the common path R10 is a common flow path through which the ink supplied from each of the branch paths R11A, R11B, and R11C passes. The common path R10 supplies the ink supplied from each of the branch paths R11A, R11B, and R11C to the damper 30 from position P1. In the following explanation, when branch paths R11A, R11B, and R11C are not distinguished, they will also be referred to as branch path R11.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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. The circulation valve 50 and the circulation pump 60 are a circulation mechanism that performs a circulation operation to return the ink supplied to the downstream of the supply path or to the damper back to the upstream of the supply path.

[0034] The printing apparatus 100 actually includes 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. Therefore, multiple cartridges 11 containing the same color of ink are installed and used in multiple slots 12 of a single ink supply unit 10.

[0035] 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.

[0036] 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.

[0037] 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, ejection heads 40, circulation valves 50, circulation pumps 60, and feeding mechanisms 70 to control the operation of each of these parts. The control unit 81 also acquires information about ink from the information storage medium 13 of each cartridge. 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.

[0038] 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.

[0039] 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.

[0040] The control unit 81 functionally comprises a remaining quantity determination unit 110, a print execution unit 120, and a maintenance execution unit 130. In the control unit 81, the CPU functions by reading a program stored in ROM into RAM, executing that program, and controlling these units.

[0041] 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.

[0042] 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.

[0043] The current ink level information for cartridge 11 is stored in the information storage medium 13 installed in cartridge 11. The ink level determination unit 110 can read the current ink level of cartridge 11 from the information storage medium 13. Furthermore, when the ink level determination unit 110 determines the ink level again, it updates the ink level information stored in the information storage medium 13 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.

[0044] 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.

[0045] 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.

[0046] In this printing process, the printing execution unit 120 performs an ink supply process in which it supplies the ink necessary for printing from one of the multiple cartridges 11 installed in the multiple slots 12 to the damper 30 and the ejection head 40 via the supply path R1. In the ink supply process, the printing execution unit 120 can selectively switch the cartridge 11 from which to supply ink among the multiple cartridges 11 based on predetermined criteria. For example, if the ink level of the cartridge currently supplying ink runs out during printing, or if the cartridge's expiration date has passed, the printing execution unit 120 switches the cartridge 11 from which to supply ink by controlling the opening and closing of the supply valve 20. The ink level and expiration date information of the cartridge 11 can be obtained by reading the information stored in the information storage medium 13 attached to the cartridge 11. This prevents the printing from being terminated midway.

[0047] The maintenance execution unit 130 performs maintenance to maintain the printing device 100 in a state where it can operate normally. Specifically, the maintenance execution unit 130 performs adhesion prevention maintenance. Adhesion prevention maintenance is maintenance to prevent ink from adhering 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. If ink adhering to the inner wall of the supply path R1 is left for a long period of time, it may harden and hinder the smooth flow of ink through the supply path R1. To prevent such ink hardening, the maintenance execution unit 130 performs adhesion prevention maintenance.

[0048] When performing anti-sticking maintenance, the maintenance execution unit 130 supplies ink to the supply path R1 from cartridges 11 that have been left unused for a predetermined period of time among the multiple cartridges 11 installed in the multiple slots 12. More specifically, the maintenance execution unit 130 opens the supply valve 20 of the cartridge 11 that has been left unused for a predetermined period of 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 130 prevents ink from flowing into the supply path R1 for a long period of time, thereby preventing ink components from solidifying within the supply path R1.

[0049] The flow of the anti-sticking maintenance process will be explained in detail with reference to Figure 3. The maintenance execution unit 130 performs the anti-sticking maintenance process as needed while the printing device 100 is in a state where it can operate normally.

[0050] In the anti-sticking maintenance process shown in Figure 3, the maintenance execution unit 130 first refers to the ink usage history, ink level, and expiration date information stored in the information storage medium 13 of each cartridge 11 to determine whether there is a cartridge 11 among the multiple cartridges 11 that is capable of supplying ink but has been left unused for a predetermined period of time or longer (step S11). Hereinafter, such a cartridge will also be referred to as an unused cartridge 11. This predetermined period is set in advance to a time length that can prevent ink from sticking, for example, one week. For example, the maintenance execution unit 130 can determine whether or not an unused cartridge 11 exists if it has not supplied ink for more than one week since being set in the slot 12, the ink level is above a threshold, and the expiration date has not passed. If there are no unused cartridges 11 (step S11; NO), the maintenance execution unit 130 stops the process at step S11.

[0051] On the other hand, if there is an unused cartridge 11 (step S11; YES), the maintenance execution unit 130 determines the supply time for the ink to be supplied from the unused cartridge 11 to the supply path during the anti-sticking maintenance (step S12). In this case, the maintenance execution unit 130 determines the supply time such that the longer the path length of the branch path R11 connected to the unused cartridge 11, the longer the supply time.

[0052] For example, a table defining the relationship between each branch path R11A, R11B, R11C and the ink supply time, as shown in Figure 4, is stored in the storage unit 82. As mentioned above, the path length increases in the order of branch paths R11A, R11B, and R11C, so in this table, the supply times are set so that the time increases in the order of branch paths R11A, R11B, and R11C. Then, the maintenance execution unit 130 can refer to this table to determine the ink supply time for the neglected cartridge 11. For example, if the neglected cartridge 11 is cartridge 11C, it is connected to branch path R11C, so the maintenance execution unit 130 refers to this table and determines the supply time to be 3 seconds.

[0053] There are various methods for determining the ink supply time in step S12. For example, the maintenance execution unit 130 stores the previously measured path lengths of each of the branch paths R11A, R11B, and R11C in the storage unit 82. The maintenance execution unit 130 may then determine the ink supply time by multiplying the path length of the branch path R11 connected to the neglected cartridge 11 by a predetermined coefficient.

[0054] Returning to Figure 3, after determining the ink supply time, the maintenance execution unit 130 starts supplying ink from the neglected cartridge 11 (step S13). Specifically, the maintenance execution unit 130 opens the supply valve 20 located downstream of the slot 12 in which the neglected cartridge 11 is installed, allowing ink to be supplied from the neglected cartridge 11 to the supply path R1. In the following description, the supply valve 20 located downstream of the slot 12 in which the neglected cartridge 11 is installed will also be referred to as the supply valve 20 of the neglected cartridge 11.

[0055] After starting the ink supply in step S13, the maintenance execution unit 130 remains in step S14 until the supply time determined in step S12 has elapsed (step S14; NO). On the other hand, after starting the ink supply in step S13 and once the supply time determined in step S12 has elapsed (step S14; YES), the maintenance execution unit 130 closes the supply valve 20 of the neglected cartridge 11 and stops the supply of ink from the neglected cartridge 11 (step S15). This completes the anti-sticking maintenance process.

[0056] Furthermore, during the execution of the above-mentioned anti-sticking maintenance process, it is desirable for the maintenance execution unit 130 to circulate the ink by opening the circulation valve 50 and operating the circulation pump 60. By circulating the ink, the flow rate of ink in the supply passage R1 increases, making it easier to remove ink component precipitates and other debris in the supply passage R1, thereby enhancing the effectiveness of the anti-sticking maintenance.

[0057] As described above, the printing apparatus 100 according to this embodiment is a device that selectively switches between cartridges 11 from among a plurality of cartridges 11 that supply ink to the ejection head 40 via a supply path R1. When there is a neglected cartridge 11 among the plurality of cartridges 11 that is capable of supplying ink but has been left unused for a predetermined period of time or longer, the device performs maintenance to prevent ink from solidifying in the supply path R1 by supplying ink from the neglected cartridge 11 to the supply path. As a result, the printing apparatus 100 performs maintenance by focusing the ink flow on the supply path, including the branch path from the neglected cartridge 11, where ink has accumulated due to being left unused for a long period and is prone to solidification, thus reliably preventing ink from solidifying in the supply path. Furthermore, since ink is supplied only from the neglected cartridge 11 among the plurality of cartridges 11, such maintenance can be performed at a low cost.

[0058] Furthermore, in the printing apparatus 100 according to this embodiment, the supply time for the ink supplied from the neglected cartridge 11 during the anti-sticking maintenance is determined to be longer as the path length of the branch path R11 connected to the neglected cartridge 11 increases. Specifically, the printing apparatus 100 increases the amount of ink supplied from the neglected cartridge 11 during the anti-sticking maintenance as the path length of the branch path R11 connected to the neglected cartridge 11 increases. As the path length of the branch path R11 increases, more ink needs to be flowed to prevent ink from sticking. By doing so, it becomes possible to perform anti-sticking maintenance by flowing an appropriate amount of ink into the supply path R1 based on the path length of the branch path R11.

[0059] 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.

[0060] (Variation 1) For example, in the above embodiment, in the anti-sticking maintenance process, the maintenance execution unit 130 increased the amount of ink supplied from the unused cartridge 11 by increasing the length of the branch path R11 connected to the unused cartridge 11. However, the amount of ink supplied may also be determined by taking into account the period during which the unused cartridge 11 was left unused. That is, the longer the unused cartridge 11 has been left unused, the longer the ink supply time from that cartridge 11 may be increased, and the amount of ink supplied may be increased. Generally, the longer the unused period, the longer the ink remains in the branch path R11 connected to that unused cartridge 11, and the more sediment accumulates, requiring a larger amount of ink to be supplied during anti-sticking maintenance. By doing so, it becomes possible to perform anti-sticking maintenance by supplying the optimal amount of ink for anti-sticking to the supply path R1.

[0061] (Modification 2) For example, in the above embodiment, in the anti-sticking maintenance process, the maintenance execution unit 130 increased the amount of ink supplied by increasing the ink supply time from the neglected cartridge 11 as the path length of the branch path connected to the neglected cartridge 11 increased. However, the ink supply time could be kept uniform for all branch paths R11, and the amount of ink supplied could be increased by increasing the opening of the supply valve 20 of the neglected cartridge 11 as the path length of the branch path R11 connected to the neglected cartridge 11 increases.

[0062] For example, a table defining the relationship between branch paths R11A, R11B, and R11C and the corresponding opening degree of the supply valve when supplying ink is stored in the memory unit, as shown in Figure 5. In this table, the opening degrees of the corresponding supply valves 20A, 20B, and 20C are set to increase in the order of branch paths R11A, R11B, and R11C, where the path length increases. Then, the maintenance execution unit 130 can refer to this table to determine the opening degree when supplying ink from the neglected cartridge 11. For example, if the neglected cartridge 11 is cartridge 11B, it is connected to branch path R11B, so the maintenance execution unit 130 can refer to this table and set the opening degree of supply valve 20B to 75% to supply ink from cartridge 11B.

[0063] (Modification 4) In the above embodiment, an anti-sticking maintenance process in the supply path R1 of a printing apparatus 100 equipped with an ink circulation mechanism was described. However, the present invention is similarly applicable to an anti-sticking maintenance process for a printing apparatus 200 that is not equipped with an ink circulation mechanism, as shown in Figure 6.

[0064] 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]

[0065] 10 Ink supply unit 11, 11A, 11B, 11C cartridges, unused cartridges 12, 12A, 12B, 12C slots 13,13A,13B,13C Information storage medium 20, 20A, 20B, 20C 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 100,200 Printing equipment 110 Remaining amount determination unit 120 Print execution unit 130 Maintenance Execution Department M Media R1 supply path R10 common road Route 11, Route 11A, Route 11B, Route 11C 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, if there is a cartridge among the plurality of cartridges that is capable of supplying ink but has been left unused for a predetermined period of time or longer, performs ink retention maintenance to prevent ink from solidifying in the supply path by supplying ink from the unused cartridge to the supply path. Printing device.

2. The supply path includes a common path shared by the plurality of cartridges, and a plurality of branch paths that branch off from the common path and connect to each cartridge. The control unit increases the amount of ink supplied from the neglected cartridge during the anti-sticking maintenance as the length of the branch path connected to the neglected cartridge increases. The printing apparatus according to claim 1.

3. The control unit increases the amount of ink supplied from the unused cartridge during the anti-sticking maintenance, the longer the period of time the unused cartridge has been left unused. The printing apparatus according to claim 1.

4. Each of the aforementioned multiple cartridges is fitted with an information storage medium that stores information about the ink in the cartridge. The control unit identifies the abandoned cartridge based on the information stored in the information storage medium. The printing apparatus according to claim 1.

5. 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, A maintenance method for a printing apparatus comprising: It is determined whether any of the aforementioned multiple cartridges contain cartridges that are capable of supplying ink but have been left unused for a predetermined period of time or longer. If there is a cartridge that has been left unused, an anti-sticking maintenance is performed to prevent ink from sticking in the supply path by supplying ink from the unused cartridge to the supply path. Maintenance methods for printing equipment.

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