Image forming apparatus

Abstract

This invention provides a means for accurately determining the amount of waste liquid held by a waste liquid cartridge. [Solution] The controller 50 performs a purging process to discharge ink from the recording head 34 to the cap 71, a process to determine the amount of waste liquid discharged from the recording head 34 by the purging process, and, after the purging process, at predetermined intervals, adds a partial waste liquid amount, which is a part of the total waste liquid amount, to the amount of waste liquid already discharged to the waste liquid cartridge 74 and writes it to the cartridge memory 75.

Description

Technical Field

[0001] The present disclosure relates to an image forming apparatus having a waste liquid cartridge that absorbs and holds waste liquid.

Background Art

[0002] Patent Document 1 discloses an image forming apparatus. The image forming apparatus has a waste liquid tank. The waste liquid tank has an ink absorber inside. The ink absorber absorbs and holds waste liquid. The waste liquid tank has two ink detection pins. From the change in the electrical resistance between the two ink detection pins, the system control unit determines whether the waste liquid tank is filled with waste liquid. Patent Document 2 discloses a liquid discharge device. The control device of the liquid discharge device causes the waste liquid amount to be stored in a storage unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an image forming apparatus, waste liquid is generated, for example, by purging that forcibly discharges ink from the nozzles of a recording head, or by flushing that continuously discharges ink droplets from the nozzles of the recording head. The waste liquid due to purging is received by a cap. The cap is connected to the waste liquid tank by a tube. The waste liquid flows from the cap through the tube to the waste liquid tank. The waste liquid due to flushing is the same.

[0005] Some image forming apparatuses have replaceable waste liquid tanks. When a waste liquid tank is full of waste liquid, it is replaced with a new one. It is possible for a user to replace the waste liquid tank while waste liquid is flowing through a tube. In this case, the waste liquid in the tube is absorbed into the new waste liquid tank. As with the liquid discharge device described in Patent Document 2, the amount of waste liquid stored in the memory unit does not include the waste liquid in the tube. Therefore, the amount of waste liquid stored in the memory unit does not match the amount of waste liquid actually held by the waste liquid tank before replacement. Furthermore, when the waste liquid in the tube is discharged into the replacement waste liquid tank, the amount of waste liquid stored in the memory unit does not match the amount of waste liquid actually held by the replacement waste liquid tank.

[0006] This disclosure is made in view of the circumstances described above, and its purpose is to provide a means for accurately determining the amount of waste liquid held by a waste liquid cartridge. [Means for solving the problem]

[0007] (1) The image forming apparatus according to the present disclosure comprises a head for discharging liquid, a receiving member for receiving the liquid discharged from the head, a waste liquid cartridge, a tube connecting the receiving member and the waste liquid cartridge so that the liquid can flow through it, a cartridge memory provided in the waste liquid cartridge, and a controller. The controller performs a discharge process for discharging liquid from the head to the receiving member, a waste liquid volume determination process for determining the amount of waste liquid to be discharged from the head by the discharge process, and a first waste liquid volume accumulation process, which, after the discharge process, adds a partial waste liquid volume, which is a part of the waste liquid volume, to the amount of waste liquid already discharged to the waste liquid cartridge and writes it to the cartridge memory at predetermined intervals.

[0008] The waste liquid generated during the discharge process flows from the receiving section through a tube to the waste liquid cartridge. After the discharge process, the controller adds the partial waste liquid amount to the total waste liquid amount at predetermined intervals and writes it to the cartridge memory. The partial waste liquid amount corresponds to the amount of waste liquid that flows from the tube into the waste liquid cartridge after a predetermined time has elapsed since the discharge process. Therefore, if the waste liquid cartridge is removed from the image forming apparatus while waste liquid remains in the tube after the discharge process, the controller cannot perform the waste liquid volume accumulation process thereafter. In other words, the amount of waste liquid remaining in the tube is not written to the cartridge memory of the waste liquid cartridge. As a result, the total waste liquid amount written to the cartridge memory is equivalent to the amount of waste liquid that actually flowed into the waste liquid cartridge.

[0009] (2) The image forming apparatus may further include an apparatus memory. The controller may perform a storage process in which, provided that the waste liquid cartridge has been removed from the image forming apparatus, the remaining waste liquid amount that has not been added to the already discharged waste liquid amount in the first waste liquid amount accumulation process has been stored in the apparatus memory, and a second waste liquid amount accumulation process in which, provided that the waste liquid cartridge has been installed in the image forming apparatus, at predetermined intervals, the partial waste liquid amount, which is a part of the remaining waste liquid amount stored in the apparatus memory, is added to the already discharged waste liquid amount to the waste liquid cartridge and written to the cartridge memory.

[0010] When a waste liquid cartridge is installed in the image forming apparatus, the controller adds a portion of the remaining waste liquid (a partial waste liquid volume) to the total waste liquid volume and writes it to the cartridge memory at predetermined intervals. As a result, the total waste liquid volume written to the cartridge memory of the installed waste liquid cartridge becomes equivalent to the actual amount of waste liquid that flowed into the cartridge.

[0011] (3) The controller may repeatedly perform the second waste liquid volume accumulation process until the accumulated partial waste liquid volume reaches the remaining waste liquid volume.

[0012] (4) The controller may obtain the amount of waste liquid already used from the cartridge memory of the waste liquid cartridge installed in the image forming apparatus.

[0013] When a waste liquid cartridge that has already been used and holds waste liquid is installed in the image forming apparatus, the controller can acquire the amount of waste liquid held in the waste liquid cartridge as the amount of waste liquid already used.

[0014] (5) The controller may repeatedly execute the first waste liquid volume accumulation process until the accumulated partial waste liquid volume reaches the waste liquid volume determined in the waste liquid volume determination process.

[0015] (6) The image forming apparatus may further include a notification unit. The controller may cause the notification unit to notify when the amount of waste liquid exceeds a threshold.

[0016] When the waste liquid cartridge is full of waste liquid, the notification unit alerts the user to the need to replace the waste liquid cartridge. [Effects of the Invention]

[0017] According to this disclosure, the amount of waste liquid held in the waste liquid tank can be determined with high accuracy. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 is a perspective view of printer 10. [Figure 2] Figure 2 is a schematic diagram showing the internal configuration of the printer 10. [Figure 3] Figure 3 is a schematic diagram showing the recording head 34 and the maintenance mechanism 51. [Figure 4] Figure 4 is a block diagram of controller 50. [Figure 5] Figure 5 is a graph showing the wastewater curve. [Figure 6] Figure 6 is a flowchart showing the waste liquid calculation process. [Figure 7]FIG. 7 is a flowchart showing the process when the waste liquid cartridge 74 is installed.

Embodiments for Carrying out the Invention

[0019] Hereinafter, the printer 10 according to the embodiment of the present invention will be described. Note that the embodiments described below are merely examples of the present invention, and it is needless to say that the embodiments can be appropriately changed without changing the gist of the present invention. Further, in the following description, the vertical direction is defined based on the state where the printer 10 is installed for use (the state in FIG. 1), the front-rear direction is defined with the side where the discharge port 13 is provided as the front side, and the left-right direction is defined when the printer 10 is viewed from the front side.

[0020] [External Configuration of Printer 10] As shown in FIG. 1, the printer 10 includes a housing 20, a panel unit 21, a paper feed tray 23, and a paper discharge tray 24. The panel unit 21 includes a display and a plurality of operation switches. The panel unit 21 displays characters, images, etc. on the display. The panel unit 21 receives the user's operation through the operation switches. The printer 10 is an example of an image forming apparatus. The panel unit 21 is an example of a notification unit.

[0021] The paper feed tray 23 is located at the lower part of the housing 20. The paper discharge tray 24 is located above the paper feed tray 23. A cover 22 is located on the side surface of the housing 20. When the cover 22 is opened, the user can access the internal space of the housing 20. The user accesses the internal space of the housing 20, for example, to replace the waste liquid cartridge 74.

[0022] As shown in FIG. 2, the housing 20 holds a printing engine inside. The printing engine mainly includes a recording head 34, a paper feed roller 25, a conveyance roller 26, a discharge roller 27, and a platen 28. The paper feed roller 25 is supported by an arm 25A and rotates about a shaft 25B. When the arm 25A rotates, the paper feed roller 25 abuts on the sheet 6 placed on the paper feed tray 23.

[0023] The feed roller 25 rotates, driven by a motor (not shown). When the feed roller 25 rotates, the sheet 6 enters the transport path 37. The transport path 37 is a space partitioned by guide members (not shown). The transport path 37 curves from the rear end of the paper feed tray 23 to a position above the paper feed tray 23, and then extends forward.

[0024] The transport roller 26 is located downstream of the paper feed tray 23 in the direction of sheet 6 transport. The transport roller 26 and the driven roller 35 form a roller pair. The transport roller 26 rotates, driven by a motor (not shown). When the transport roller 26 rotates, the sheet 6, held between the transport roller 26 and the driven roller 35, is transported in the transport direction.

[0025] The discharge roller 27 is located downstream of the transport roller 26 in the transport direction of the sheet 6. The discharge roller 27 and the driven roller 36 form a roller pair. The discharge roller 27 rotates, driven by a motor (not shown). When the discharge roller 27 rotates, the sheet 6, held between the discharge roller 27 and the driven roller 36, is transported in the transport direction and discharged into the paper output tray 24.

[0026] The platen 28 is positioned between the conveying roller 26 and the discharge roller 27 in the front-rear direction. The platen 28 supports the sheet 6 from below.

[0027] The recording head 34 is located between the transport roller 26 and the discharge roller 27. The recording head 34 is driven by a motor (not shown) and is movable along the left-right direction. When in standby mode, the recording head 34 is located in a maintenance position to the left of the platen 28. The recording head 34 is connected to the tank 70 by a tube 31. Through the tube 31, ink stored in the tank 70 is supplied to the recording head 34. The recording head 34 is an example of a head.

[0028] The recording head 34 has a plurality of nozzles 33 that open toward the platen 28. The lower surface of the recording head 34 is the nozzle surface 33A (see Figure 3). When the sheet 6 is supported and stopped by the platen 28, the recording head 34 moves along the left-right direction and selectively ejects ink droplets from the plurality of nozzles 33. The transport of the sheet 6 and the ejection of ink droplets by the recording head 34 are repeated alternately. As a result, an image is recorded on the sheet 6 supported by the platen 28. Note that the recording head 34 may be a line head instead of a serial head.

[0029] [Maintenance mechanism 51] As shown in Figure 3, the maintenance mechanism 51 includes a cap 71, a waste liquid tube 71A, a wiper 72, a pump 73, a waste liquid cartridge 74, a cartridge memory 75, and a joint 76. The cap 71 is an example of a receiving member. The waste liquid tube 71A is an example of a tube.

[0030] The cap 71 is made of an elastic material such as rubber. The cap 71 is located below the recording head 34 in the maintenance position. The cap 71 has a cup shape that opens upwards. The cap 71 is movable in the vertical direction. As shown by the dashed line in Figure 3, the cap 71 is in close contact with the nozzle surface 33A of the recording head 34 in the maintenance position, covering the openings of all the nozzles 33. The cap 71 may be moved by a motor, or by mechanically transmitted movement of the recording head 34.

[0031] A waste ink tube 71A is connected to the cap 71. An outlet is formed at the bottom of the cap 71. One end of the waste ink tube 71A is connected to the outlet. The other end of the waste ink tube 71A is connected to a joint 76. The joint 76 can be connected to a waste ink cartridge 74. Although not shown in the diagram, the joint 76 has a valve. The valve opens when the waste ink cartridge 74 is connected. When the valve is open, ink can flow from the waste ink tube 71A to the waste ink cartridge 74. When the waste ink cartridge 74 is removed from the joint 76, the valve closes. When the valve is closed, ink does not flow out of the joint 76. Therefore, when the valve is closed, the ink remaining in the waste ink tube 71A does not flow out of the joint 76.

[0032] Pump 73 is located in the middle of the waste liquid tube 71A. Pump 73 is schematically shown in Figure 3. Pump 73 is a so-called tube pump. As the rollers of pump 73 rotate while crushing the waste liquid tube 71A, negative pressure is created inside the waste liquid tube 71A. This negative pressure also creates negative pressure inside the cap 71, drawing ink out from the nozzle 33 of the recording head 34. Pump 73 has a valve, and opening and closing the valve releases the internal space of the waste liquid tube 71A to the atmosphere. When the internal space of the waste liquid tube 71A is released to the atmosphere, waste ink flows from the cap 71 to the waste liquid cartridge 74 due to gravity, capillary force, etc.

[0033] The wiper 72 is located to the right of the cap 71. The wiper 72 is movable in the vertical direction. The wiper 72 holds the tip of a wiper blade, which is made of an elastic material such as rubber, facing upward. When the wiper 72 is in the upward position, the tip 72A of the wiper blade comes into contact with the nozzle surface 33A of the recording head 34, which moves along the left-right direction. As a result, the wiper 72 wipes away ink droplets adhering to the nozzle surface 33A of the recording head 34.

[0034] The waste ink cartridge 74 is box-shaped. The internal space of the waste ink cartridge 74 is filled with an ink absorber such as foamed resin. Ink that flows into the waste ink cartridge 74 is absorbed and retained by the ink absorber. The waste ink cartridge 74 has a cartridge memory 75. The cartridge memory 75 stores information such as the amount of waste ink. The cartridge memory is a non-volatile memory such as NVRAM. The waste ink cartridge 74 is detachable from the housing 20. When the waste ink cartridge 74 is installed in the housing 20, the cartridge memory 75 can electrically communicate with the controller 50 via contacts (not shown).

[0035] [Controller 50] As shown in Figure 4, the controller 50 includes a CPU 51, ROM 52, RAM 53, EEPROM 54, and ASIC 55. The CPU 51, ROM 52, RAM 53, EEPROM 54, and ASIC 55 are connected to each other via an internal bus 56. The CPU 51, ROM 52, RAM 53, EEPROM 54, and ASIC 55 are mounted on a circuit board provided inside the enclosure 20.

[0036] ROM 52 stores programs for controlling the operation of the printer 10. The CPU 51 executes the programs using RAM 53 and EEPROM 54. EEPROM 54 stores functions that indicate the amount of waste liquid, thresholds, and waste liquid curves. EEPROM 54 is an example of device memory.

[0037] The ink discharged from the recording head 34 to the cap 71 requires time to circulate through the waste liquid tube 71A before it flows into the waste liquid cartridge 74. In other words, the amount of waste liquid discharged during the purging process does not immediately flow into the waste liquid cartridge 74 after the purging process is performed. The waste liquid curve shows the change in the amount of waste liquid that actually flows into the waste liquid cartridge 74 after the purging process is performed.

[0038] The waste liquid curve is, for example, the curve shown in Figure 5. In Figure 5, the horizontal axis represents the elapsed time since waste ink was generated by the purging process. For example, zero is the point when the purging process is completed and the internal space of the waste liquid tube 71A is opened to the atmosphere. The vertical axis represents the amount of waste liquid flowing into the waste liquid cartridge 74. The amount of waste liquid flowing through the waste liquid tube 71A and into the waste liquid cartridge 74 increases with elapsed time, while changing its slope. A function representing this absorption curve is stored in the EEPROM 54. The function is, for example, y = f(t), where y represents the amount of waste liquid and t represents the elapsed time.

[0039] Furthermore, the waste liquid curve can differ depending on whether the waste liquid cartridge 74 is installed in the housing 20 during the purging process or not. When the purging process is performed without the waste liquid cartridge 74 installed in the housing 20, the waste liquid remains in the waste liquid tube 71A and stays near the joint 76. In this state, when the waste liquid cartridge 74 is connected to the joint 76, the waste liquid remaining in the waste liquid tube 71A immediately flows into the waste liquid cartridge 74. The function in this case can be represented, for example, by g=f(t).

[0040] When the controller 50 receives a job transmitted by an information processing device that can communicate with the printer 10, it controls the various components of the printer 10 in order to record an image based on image data according to the condition information. The controller 50 also performs maintenance processing on the recording head 34.

[0041] The maintenance process is, for example, a purging process in which ink is forcibly discharged from the nozzles 33 while the recording head 34 is covered by the cap 71. Alternatively, the maintenance process may be a flushing process in which ink droplets are continuously discharged from the nozzles 33 of the recording head 34 above the cap 71. In the purging process, the controller 50 drives the pump 73, causing ink to be discharged from the nozzles 33 of the recording head 34, which is covered by the cap 71. The ink discharged from the recording head 34 is received by the cap 71 and flows to the waste ink cartridge 74 via the waste ink tube 71A.

[0042] [Waste liquid volume calculation process] The waste liquid volume calculation process performed by the controller 50 will be explained below with reference to Figure 6. The controller 50 executes a purge process at a predetermined timing (S10). The predetermined timing may be when a predetermined time has elapsed since the power was turned on, when a predetermined number of images have been recorded, when a predetermined amount of ink has been used, or when the user has input to execute a purge process.

[0043] During the purging process, the controller 50 moves the recording head 34 to the maintenance position and moves the cap 71 upward. With the cap 71 covering the nozzle surface 33A of the recording head 34, the controller 50 drives the pump 73. This causes ink to be discharged from the nozzle 33 of the recording head 34 to the cap 71. The purging process is one example of an ink discharge process.

[0044] The amount of waste liquid discharged from the nozzle 33 by the purging process is stored in the EEPROM 54 beforehand. The waste liquid amount is, for example, A milliliters. Here, the amount of waste liquid discharged from the nozzle 33 by the purging process is referred to as waste liquid amount A. After executing the purging process, the controller 50 reads waste liquid amount A from the EEPROM 54 (S11). Note that there may be multiple types of purging processes, not just a single one. In that case, multiple waste liquid amounts corresponding to the types of purging processes are stored in the EEPROM 54 beforehand. The process of obtaining waste liquid amount A from the EEPROM 54 is an example of a waste liquid amount determination process.

[0045] Next, the controller 50 resets t, which is the elapsed time count value, to zero (S12). In this embodiment, t is set as an integer from 0 to 10. The elapsed time required for t to be counted once is predetermined and stored in the EEPROM 54. After that, the controller 50 activates the timer to monitor the elapsed time.

[0046] When the controller 50 determines that a predetermined elapsed time has elapsed (S13: Yes), it increments the count value t by one. In this case, it increments from 0 to 1 (S14).

[0047] Next, the controller 50 determines whether the waste liquid cartridge 74 is installed in the housing 20 (S15). The controller 50 determines whether the waste liquid cartridge 74 is installed in the housing 20 by determining whether the cartridge memory 75 is electrically accessible. Alternatively, a sensor or the like may be provided in the housing 20, and the controller may determine whether the waste liquid cartridge 74 is installed in the housing 20 based on the output of the sensor.

[0048] The controller 50 determines that the waste liquid cartridge 74 is not installed in the housing 20 (S15: No) and writes the amount of waste liquid that has not yet flowed into the waste liquid cartridge 74 to the EEPROM 54 (S19). Here, since t=1, no waste liquid has yet flowed into the waste liquid cartridge 74, so the amount of waste liquid A is written to the EEPROM 54. After that, the controller 50 terminates the waste liquid amount calculation process.

[0049] For example, if t=2, the controller 50 substitutes t=1 and t=10 into the function to calculate y1=f(1) and y10=f(10). Furthermore, the controller 50 calculates the difference between y1 and y10. The calculated difference is the amount of waste liquid that has not flowed into the waste liquid cartridge 74. Step S19 is an example of memory processing.

[0050] In response to determining that the waste liquid cartridge 74 is installed in the housing 20 (S15: Yes), the controller 50 substitutes t=0 and t=1 into the function to calculate y0=f(0) and y1=f(1). Furthermore, the controller 50 calculates the difference between y1 and y0 (S16). The controller 50 writes the calculated difference to the EEPROM 54 and the cartridge memory 75 (S17). The calculated difference is an example of the partial waste liquid amount. The difference written to the cartridge memory 75 is an example of the total waste liquid amount. Steps S16 and S17 are an example of the first waste liquid amount accumulation process.

[0051] The controller 50 determines whether t has reached the upper limit of 10 (S18). Here, t=1, so it is determined that t is not at the upper limit (S18: No). When the controller 50 determines that t is not at the upper limit, it returns to step S13.

[0052] In step S13, the controller 50 increments t by one to t=2 and executes steps S14 to S19. In step S16, the controller 50 substitutes t=1 and t=2 into the function to calculate y1=f(1) and y2=f(2). Furthermore, the controller 50 calculates the difference between y2 and y1. In step S17, the controller 50 adds the calculated difference to the difference stored in the EEPROM 54 and writes it to the EEPROM 54 and the cartridge memory 75.

[0053] The controller 50 executes steps S13 to S18 until t reaches the upper limit of 10. When the controller 50 determines that t has reached the upper limit of 10 (S18: Yes), it terminates the waste liquid volume calculation process. When t reaches the upper limit of 10, the difference written to the EEPROM 54 and the cartridge memory 75 becomes the waste liquid volume A.

[0054] The following describes the process when the waste liquid cartridge 74 is replaced after the purging process has been performed, with reference to Figure 7. In the printer 10, the waste liquid cartridge 74 can be removed by the user at any time. Therefore, it is possible that the waste liquid cartridge 74 may be removed after the purging process has been performed. In that case, some of the waste liquid will flow into the removed waste liquid cartridge 74, but some of the waste liquid may remain in the waste liquid tube 71A. Also, the waste liquid cartridge 74 that the user subsequently installs in the housing 20 may not be new.

[0055] The controller 50 determines whether the waste liquid cartridge 74 is installed in the housing 20 (S20). If the controller 50 determines that the waste liquid cartridge 74 is not installed in the housing 20 (S20: No), it repeats step S20 at a predetermined timing.

[0056] When the controller 50 determines that the waste liquid cartridge 74 has been installed in the housing 20 (S20: Yes), it reads the amount of waste liquid already stored in the cartridge memory 75 (S21). The controller 50 determines that the waste liquid cartridge 74 has been installed in the housing 20, for example, when the state changes from one inaccessible to the cartridge memory 75 to one that is accessible electrically.

[0057] The controller 50 determines that the waste liquid cartridge 74 has been installed in the housing 20 and resets the elapsed time count value t to zero (S22). In this embodiment, t is set as an integer from 0 to 5. The elapsed time required for t to be counted once is predetermined and stored in the EEPROM 54. After that, the controller 50 activates a timer to monitor the elapsed time.

[0058] When the controller 50 determines that a predetermined elapsed time has elapsed (S23: Yes), it increments the count value t by one. In this case, it increments from 0 to 1 (S24).

[0059] The controller 50 substitutes t=0 and t=1 into the function to calculate y0=g(0) and y1=g(1). Furthermore, the controller 50 calculates the difference between y1 and y0 (S25). The controller 50 writes the calculated difference to the EEPROM 54 and the cartridge memory 75 (S26). The calculated difference is an example of partial waste liquid volume. The difference written to the cartridge memory 75 is an example of total waste liquid volume. Steps S25 and S26 are an example of the second waste liquid volume accumulation process.

[0060] The controller 50 determines whether t has reached the upper limit (S27). This upper limit does not have to be 10. Here, 5 is set as the upper limit. If the controller 50 determines that t is not at the upper limit (S27: No), it returns to step S23.

[0061] In step S24, the controller 50 increments t by one to t=2 and executes steps S25 through S27. In step S25, the controller 50 substitutes t=1 and t=2 into the function to calculate y1=g(1) and y2=g(2). Furthermore, the controller 50 calculates the difference between y2 and y1. In step S26, the controller 50 adds the calculated difference to the difference stored in the EEPROM 54 and writes it to the EEPROM 54 and the cartridge memory 75.

[0062] The controller 50 executes steps S23 to S27 until t reaches the upper limit of 5. When the controller 50 determines that t has reached the upper limit of 5 (S27: Yes), it terminates the process. When t reaches the upper limit of 5, the difference written to the EEPROM 54 and the cartridge memory 75 becomes the amount of residual waste liquid remaining in the waste liquid tube 71A.

[0063] The controller 50 reads the amount of waste liquid stored in the EEPROM 54 or cartridge memory 75 at a predetermined timing. If the read amount of waste liquid exceeds a threshold, the controller 50 displays on the panel unit 21's display that the waste liquid cartridge 74 needs to be replaced.

[0064] [Effects of the Embodiment] The waste liquid generated by the purging process flows from the cap 71 through the waste liquid tube 71A to the waste liquid cartridge 74. After the purging process, the controller 50 adds the partial waste liquid amount calculated based on the function y=f(t) to the total waste liquid amount and writes it to the cartridge memory 75 at predetermined intervals. Therefore, if the waste liquid cartridge 74 is removed from the printer 10 while waste liquid remains in the waste liquid tube 71A after the purging process, the controller 50 cannot perform the waste liquid amount accumulation process thereafter. In other words, the amount of waste liquid remaining in the waste liquid tube 71A is not written to the cartridge memory 75 of the waste liquid cartridge 74. As a result, the total waste liquid amount written to the cartridge memory 75 is equivalent to the amount of waste liquid that actually flowed into the waste liquid cartridge 74. This allows for accurate determination of the amount of waste liquid held by the waste liquid cartridge 74.

[0065] Furthermore, when the waste liquid cartridge 74 is installed in the printer 10, the controller 50 adds a portion of the remaining waste liquid, calculated based on the function y=g(t), to the total amount of waste liquid already present at predetermined intervals and writes it to the cartridge memory 75. As a result, the amount of waste liquid already present written to the cartridge memory 75 of the installed waste liquid cartridge 74 becomes equivalent to the amount of waste liquid that actually flowed into the waste liquid cartridge 74.

[0066] Furthermore, the controller 50 can obtain the amount of waste liquid already used from the cartridge memory 75 of the waste liquid cartridge 74 installed in the printer 10.

[0067] Furthermore, the controller 50 displays on the panel unit 21's display that the waste liquid cartridge 74 needs to be replaced when the amount of waste liquid exceeds a threshold, so the user is aware that the waste liquid cartridge 74 needs to be replaced.

[0068] [Differentiation] In the embodiments described above, purging was described as an example of discharge processing. Alternatively, or in addition to this, flushing may be used as discharge processing. In that case, the receiving member does not have to be the cap 71. Furthermore, the purging process does not have to be a method of sucking ink into the cap 71 with negative pressure generated by the pump 73. For example, the inside of the tube 31 connected to the recording head 34 may be pressurized to forcibly discharge ink from the recording head 34.

[0069] Alternatively, the controller 50 calculated the partial waste liquid volume based on a function. Alternatively, a table showing the partial waste liquid volume for predetermined time intervals may be stored in the EEPROM 54 or the like, and the controller 50 may refer to the table at each elapsed time to determine the partial waste liquid volume.

[0070] Furthermore, the controller 50 displayed on the panel unit 21 that the waste liquid cartridge 74 needed to be replaced. Alternatively, the controller 50 may sound a buzzer or display a message on the screen of an information processing device connected to the printer 10 as a notification to the user. [Explanation of symbols]

[0071] 10. Printer (image forming apparatus) 21... Panel Unit (News Department) 34... Recording head (head) 50... Controller 54. EEPROM (Device Memory) 71...Cap (receiving component) 71A...Waste liquid tube (tube) 74...Waste liquid cartridge 75... Cartridge Memory

Claims

1. A head for discharging liquid, A receiving member for receiving the liquid discharged from the head, Waste liquid cartridge and A tube that connects the above-mentioned receiving member and the above-mentioned waste liquid cartridge so that liquid can flow through it, The cartridge memory provided in the above waste liquid cartridge, It is equipped with a controller, The above controller is A discharge process for discharging liquid from the head to the receiving member, A waste liquid volume determination process to determine the amount of waste liquid discharged from the head by the above discharge process, An image forming apparatus that, after the above discharge process, performs a first waste liquid volume accumulation process at predetermined intervals, which adds a portion of the above waste liquid volume, which is a part of the above waste liquid volume, to the amount of waste liquid already discharged to the above waste liquid cartridge and writes it to the cartridge memory.

2. It also has additional device memory, The above controller, on the condition that the waste liquid cartridge has been removed from the image forming apparatus, performs a storage process to store in the device memory the amount of remaining waste liquid that has not been added to the amount of waste liquid already used in the first waste liquid volume accumulation process, The image forming apparatus according to claim 1, wherein, provided that the waste liquid cartridge is installed in the image forming apparatus, a second waste liquid volume accumulation process is performed, at predetermined intervals, which adds a partial waste liquid volume, which is a portion of the remaining waste liquid volume stored in the apparatus memory, to the amount of waste liquid already discharged to the waste liquid cartridge and writes it to the cartridge memory.

3. The image forming apparatus according to claim 2, wherein the controller repeatedly performs the second waste liquid volume accumulation process until the accumulated partial waste liquid volume reaches the remaining waste liquid volume.

4. The image forming apparatus according to claim 2 or 3, wherein the controller acquires the amount of waste liquid already used from the cartridge memory of the waste liquid cartridge installed in the image forming apparatus.

5. The image forming apparatus according to any one of claims 1 to 3, wherein the controller repeatedly performs the first waste liquid volume accumulation process until the accumulated partial waste liquid volume reaches the waste liquid volume determined in the waste liquid volume determination process.

6. It also has a news department, The image forming apparatus according to claim 5, wherein the controller causes the notification unit to notify when the amount of waste liquid exceeds a threshold.

Images