Liquid dispensing device

Abstract

To reduce wasteful consumption of liquid.SOLUTION: When an ink level R exceeds a first ink level (S301) in all of ink cartridges storing four colors of inks upon reception of an inspection instruction signal commanding an inspection of as to whether nozzles are abnormal, post-inspection ink level Rc representing an ink level after performing inspection processing is calculated for each ink cartridge (S302). When the post-inspection ink level Rc exceeds the first ink level R1 for all the four ink cartridges (S303), inspection processing for performing inspection driving to check whether the nozzles are abnormal is executed for all of the nozzles 10 which discharge the four colors of inks (S306).SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a liquid ejection device that ejects liquid from a nozzle. [Background technology]

[0002] As an example of a liquid ejection device that ejects liquid from a nozzle, Patent Document 1 describes an inkjet printer that ejects ink droplets from a nozzle. The printer described in Patent Document 1 executes a nozzle inspection process to check whether ink droplets are ejected normally from the nozzle, and when an abnormal nozzle is found, determines the type of cleaning. Then, the remaining amount of ink is compared with the amount of ink consumed in cleaning, and if the remaining amount of ink is sufficient, cleaning is executed. On the other hand, if the remaining amount of ink is insufficient, the type of cleaning is changed to reduce the amount of ink consumed in cleaning, or cleaning is not executed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-58463 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, as described above, after the nozzle inspection process is performed, the remaining ink amount is compared with the amount of ink consumed in cleaning to determine whether or not the remaining ink amount is insufficient, but the nozzle inspection process also consumes ink. If the ink consumption in the nozzle inspection reduces the remaining ink amount to an amount that makes it impossible to print, the ink consumption in the nozzle inspection process will be wasted.

[0005] An object of the present invention is to provide a liquid ejection device capable of minimizing wasteful consumption of liquid. [Means for solving the problem]

[0006] The liquid ejection device of the present invention comprises a liquid ejection head having a nozzle for ejecting liquid, a liquid tank for storing liquid to be supplied to the liquid ejection head, remaining amount information acquisition means for acquiring remaining amount information indicating the remaining amount of liquid in the liquid tank, and a signal output section for outputting a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to determine whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid. A recovery means for performing a recovery operation to discharge liquid from the nozzle; a control device, wherein the control device receives an inspection instruction signal instructing to inspect whether the nozzle is the abnormal nozzle, and when the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds a threshold value, calculates a post-inspection remaining amount, which is the remaining amount of liquid in the liquid tank after the inspection drive is performed by the liquid ejection head, based on the remaining amount information, and when the post-inspection remaining amount exceeds the threshold value, causes the liquid ejection head to perform the inspection drive, and when the post-inspection remaining amount is equal to or less than the threshold value, causes the liquid ejection head to perform the inspection drive. and when the determination signal output from the signal output unit indicates the presence of the abnormal nozzle, the control unit calculates a post-recovery remaining amount, which is the remaining amount of liquid in the liquid tank after the recovery operation is performed by the recovery means, and when the post-recovery remaining amount exceeds the threshold value, the control unit causes the recovery means to perform the recovery operation, and when the post-recovery remaining amount is equal to or less than the threshold value, the control unit does not cause the recovery means to perform the recovery operation. . The liquid ejection device of the present invention further comprises a liquid ejection head having, as nozzles for ejecting liquid, a first nozzle for ejecting a first liquid, and a second nozzle, separate from the first nozzle, for ejecting a second liquid of a different type from the first liquid, a first liquid tank for storing the first liquid to be supplied to the liquid ejection head, a second liquid tank, separate from the first liquid tank, for storing the second liquid to be supplied to the liquid ejection head, remaining amount information acquisition means for acquiring first remaining amount information indicating the remaining amount of the first liquid in the first liquid tank and second remaining amount information indicating the remaining amount of the second liquid in the second liquid tank, and a detection means for confirming whether the nozzle is an abnormal nozzle having an abnormality in ejecting liquid. a control device; and a signal output unit that outputs a determination signal indicating whether or not the nozzle is the abnormal nozzle when the liquid ejection head is driven for inspection, wherein the control device receives an inspection instruction signal that instructs to inspect whether or not the nozzle is the abnormal nozzle, and when the remaining amount of the first liquid in the liquid tank indicated by the first remaining amount information exceeds a first threshold value and the remaining amount of the second liquid in the other liquid tank indicated by the second remaining amount information exceeds a second threshold value, calculates a first post-inspection remaining amount, which is the remaining amount of the first liquid in the first liquid tank after the inspection drive is performed by the liquid ejection head, based on the first remaining amount information, A second post-inspection remaining amount, which is the remaining amount of the second liquid in the second liquid tank after the inspection drive is performed by the liquid ejection head based on the second remaining amount information, is calculated, and if the first post-inspection remaining amount exceeds the first threshold value and the second post-inspection remaining amount exceeds the second threshold value, the liquid ejection head is caused to perform the inspection drive for each of the first nozzle and the second nozzle, and if the first post-inspection remaining amount is equal to or less than the first threshold value or the second post-inspection remaining amount is equal to or less than the second threshold value, the liquid ejection head is not caused to perform the inspection drive for either the first nozzle or the second nozzle. Further, a liquid ejection device of the present invention comprises a liquid ejection head having a nozzle for ejecting liquid, a liquid tank for storing liquid to be supplied to the liquid ejection head, remaining amount information acquisition means for acquiring remaining amount information indicating the remaining amount of liquid in the liquid tank, a signal output unit for outputting a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is caused to perform an inspection drive for checking whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, and a control device, wherein the control device receives an inspection instruction signal instructing to inspect whether or not the nozzle is the abnormal nozzle, and detects whether or not the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds a threshold value. If it exceeds the threshold value, a post-inspection remaining amount, which is the remaining amount of liquid in the liquid tank after the inspection drive is performed by the liquid ejection head, is calculated based on the remaining amount information, and if the post-inspection remaining amount exceeds the threshold value, the liquid ejection head is caused to perform the inspection drive, and if the post-inspection remaining amount is equal to or less than the threshold value, the liquid ejection head is not caused to perform the inspection drive, and when the determination signal is received in a sleep state, if the post-inspection remaining amount exceeds the threshold value, the sleep state is canceled and the liquid ejection head is caused to perform the inspection drive, and if the post-inspection remaining amount is equal to or less than the threshold value, the sleep state is not canceled. Further, a liquid ejection device of the present invention comprises a liquid ejection head having a nozzle for ejecting liquid, a liquid tank for storing liquid to be supplied to the liquid ejection head, a remaining amount information acquisition means for acquiring remaining amount information indicating the remaining amount of liquid in the liquid tank, a signal output section for outputting a determination signal indicating whether the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, and a control device, the control device receiving an inspection instruction signal instructing to inspect whether the nozzle is an abnormal nozzle, and acquiring the remaining amount information indicating the remaining amount of liquid in the liquid tank, if the remaining amount of liquid in the liquid tank exceeds a threshold value, a post-inspection remaining amount, which is the remaining amount of liquid in the liquid tank after the inspection drive is performed by the liquid ejection head, is calculated based on the remaining amount information, and if the post-inspection remaining amount exceeds the threshold value, the liquid ejection head is caused to perform the inspection drive, and if the post-inspection remaining amount is equal to or less than the threshold value, the liquid ejection head is not caused to perform the inspection drive, and when the remaining amount of liquid in the liquid tank becomes equal to or less than a first remaining amount, a notification signal is output to notify that the liquid ejection head can no longer eject liquid from the nozzle to the ejected medium, and the threshold value is the first remaining amount. Further, a liquid ejection device of the present invention comprises a liquid ejection head having a nozzle for ejecting liquid, a liquid tank for storing liquid to be supplied to the liquid ejection head, a remaining amount information acquisition means for acquiring remaining amount information indicating the remaining amount of liquid in the liquid tank, a signal output section for outputting a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is caused to perform an inspection drive for checking whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, and a control device, wherein the control device receives an inspection instruction signal instructing to inspect whether or not the nozzle is the abnormal nozzle, and when the remaining amount information indicates that the remaining amount of liquid in the liquid tank exceeds a threshold Based on the remaining amount information, a post-test remaining amount, which is the remaining amount of liquid in the liquid tank after the test drive is performed by the liquid ejection head, is calculated, and if the post-test remaining amount exceeds the threshold value, the liquid ejection head is caused to perform the test drive, and if the post-test remaining amount is equal to or less than the threshold value, the liquid ejection head is not caused to perform the test drive, and when the remaining amount of liquid in the liquid tank becomes equal to or less than a second remaining amount that is greater than a first remaining amount at which the liquid ejection head is no longer able to eject liquid from the nozzles to the ejected medium, an alarm signal is output to alarm that the remaining amount of liquid in the liquid tank is low, and the threshold value is the second remaining amount. Further, a liquid ejection device of the present invention includes a liquid ejection head having a nozzle for ejecting liquid, a liquid tank for storing liquid to be supplied to the liquid ejection head, a remaining amount information acquisition means for acquiring remaining amount information indicating the remaining amount of liquid in the liquid tank, a signal output section for outputting a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is caused to perform an inspection drive for checking whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, and a control device, wherein the control device receives an inspection instruction signal instructing to inspect whether or not the nozzle is the abnormal nozzle, and when the remaining amount information indicates that the remaining amount of liquid in the liquid tank exceeds a threshold value, the control device Based on the information, a post-test remaining amount, which is the remaining amount of liquid in the liquid tank after the test drive is performed by the liquid ejection head, is calculated, and if the post-test remaining amount exceeds the threshold, the liquid ejection head is caused to perform the test drive, and if the post-test remaining amount is equal to or less than the threshold, the liquid ejection head is not caused to perform the test drive, and when the remaining amount of liquid in the liquid tank becomes equal to or less than a second remaining amount that is greater than a first remaining amount at which the liquid ejection head is no longer able to eject liquid from the nozzles to the ejected medium, an alarm signal is output to alarm that the remaining amount of liquid in the liquid tank is low, and the threshold is a third remaining amount that is greater than the second remaining amount.

[0007] Also, a liquid ejection apparatus of the present invention comprises a liquid ejection head having a nozzle for ejecting liquid, a liquid tank for storing liquid to be supplied to the liquid ejection head, remaining amount information acquisition means for acquiring remaining amount information indicating the remaining amount of liquid in the liquid tank, a signal output section for outputting a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is caused to perform an inspection drive for checking whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means for performing a recovery operation to discharge liquid from the nozzle, and a control device, wherein the control device receives an inspection instruction signal instructing to inspect whether or not the nozzle is the abnormal nozzle. and if the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds a threshold value, the liquid ejection head is caused to perform the inspection drive, and further, a post-recovery remaining amount, which is the remaining amount of liquid in the liquid tank after the recovery operation when the recovery means is caused to perform the recovery operation, is calculated, and if the post-recovery remaining amount exceeds the threshold value, the liquid ejection head is caused to perform the inspection drive, and further, if the determination signal output from the signal output unit indicates the presence of an abnormal nozzle, the recovery means is caused to perform the recovery operation, and if the post-recovery remaining amount is equal to or less than the threshold value, the liquid ejection head is not caused to perform the inspection drive. Effect of the Invention

[0009] According to the present invention, it is possible to reduce wasteful consumption of liquid. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a printer according to a first embodiment. [Diagram 2] 4A and 4B are diagrams for explaining detection electrodes disposed in a cap, and the connection relationship between the detection electrodes and a high-voltage power supply circuit and a determination circuit. [Diagram 3] FIG. 2A is a diagram showing the change in potential of the detection electrode when ink is ejected from the nozzle, and FIG. 2B is a diagram showing the change in potential of the detection electrode when ink is not ejected from the nozzle. [Figure 4]FIG. 2 is a block diagram showing the electrical configuration of the printer. [Diagram 5] FIG. 10A is a flowchart showing the process for detecting when the amount of ink remaining in an ink cartridge is low, and FIG. 10B is a flowchart showing the process for transitioning the printer to a sleep state. [Figure 6] 10 is a flowchart showing a process flow when an inspection instruction signal is input. [Figure 7] 10 is a flowchart showing a process for performing regular maintenance in the second embodiment. [Figure 8] 13 is a flowchart showing a process flow when an inspection instruction signal is input in the first modification. [Figure 9] 13 is a flowchart showing a process flow when an inspection instruction signal is input in Modification 2. [Figure 10] 13 is a flowchart showing a process flow when an inspection instruction signal is input in Modification 3. [Figure 11] 13 is a flowchart showing a process flow when an inspection instruction signal is input in the fourth modification example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [First embodiment] A first preferred embodiment of the present invention will now be described.

[0012] <Overall printer configuration> As shown in FIG. 1, the printer 1 (the "liquid ejection device" of the present invention) according to the first embodiment includes a carriage 2, a subtank 3, an inkjet head 4 (the "liquid ejection head" of the present invention), a platen 5, transport rollers 6 and 7, a maintenance unit 8, etc.

[0013] The carriage 2 is supported by two guide rails 11, 12 extending in the scanning direction. The carriage 2 is connected to a carriage motor 86 (see FIG. 4) via a belt (not shown) or the like, and when the carriage motor 86 is driven, the carriage 2 moves in the scanning direction along the guide rails 11, 12. In the following description, the right and left sides of the scanning direction are defined as shown in FIG. 1.

[0014] The subtank 3 is mounted on the carriage 2. Here, the printer 1 is equipped with a cartridge holder 13, in which four ink cartridges 14 are removably attached. The four ink cartridges 14 are lined up in the scanning direction, and from the one arranged on the right side in the scanning direction, they store black, yellow, cyan, and magenta ink. The subtank 3 is connected to the four ink cartridges 14 attached to the cartridge holder 13 via four tubes 15. In this way, the four colors of ink are supplied to the subtank 3 from the four ink cartridges 14.

[0015] The inkjet head 4 is mounted on the carriage 2 and connected to the lower end of the subtank 3. The inkjet head 4 is supplied with the four colors of ink from the subtank 3. The inkjet head 4 ejects ink from a plurality of nozzles 10 formed on its lower surface, a nozzle face 4a. More specifically, the nozzles 10 are arranged in a transport direction perpendicular to the scanning direction to form a nozzle row 9, and on the nozzle face 4a, four nozzle rows 9 are lined up in the scanning direction. From the nozzles 10, black, yellow, cyan, and magenta inks are ejected starting from the nozzle row 9 on the right side of the scanning direction.

[0016] The platen 5 is disposed below the inkjet head 4 and faces the multiple nozzles 10. The platen 5 extends over the entire length of the recording paper P (the "ejection receiving medium" of the present invention) in the scanning direction and supports the recording paper P from below. The transport roller 6 is disposed upstream of the inkjet head 4 and the platen 5 in the transport direction. The transport roller 7 is disposed downstream of the inkjet head 4 and the platen 5 in the transport direction. The transport rollers 6 and 7 are connected to a transport motor 87 (see FIG. 4) via gears and the like (not shown). When the transport motor 87 is driven, the transport rollers 6 and 7 rotate and the recording paper P is transported in the transport direction.

[0017] The maintenance unit 8 includes a cap 71, a suction pump 72, and a waste liquid tank 73. The cap 71 is disposed to the right of the platen 5 in the scanning direction. When the carriage 2 is positioned at a maintenance position to the right of the platen 5 in the scanning direction, the multiple nozzles 10 face the cap 71.

[0018] The cap 71 can be raised and lowered by a cap lifting mechanism 88 (see FIG. 4). When the carriage 2 is positioned at the maintenance position so that the plurality of nozzles 10 and the cap 71 face each other, the cap 71 is raised by the cap lifting mechanism 88, whereby the upper end of the cap 71 comes into close contact with the nozzle surface 4a, and the plurality of nozzles 10 are covered by the cap 71. Note that the cap 71 is not limited to covering the plurality of nozzles 10 by coming into close contact with the nozzle surface 4a. The cap 71 may cover the plurality of nozzles 10 by coming into close contact with a frame (not shown) or the like that is arranged around the nozzle surface 4a of the inkjet head 4, for example.

[0019] The suction pump 72 is a tube pump or the like, and is connected to the cap 71 and the waste liquid tank 73. In the maintenance unit 8, when the suction pump 72 is driven with the plurality of nozzles 10 covered with the cap 71 as described above, it is possible to perform a so-called suction purge, in which ink is discharged from inside the inkjet head 4 through the plurality of nozzles 10. The ink discharged by the suction purge is stored in the waste liquid tank 73.

[0020] In the first embodiment, it is possible to selectively perform one of a number of types of suction purge with different ink discharge amounts. The ink discharge amount differs between the multiple types of suction purge due to, for example, at least one of the driving time of the suction pump 72 and the rotation speed of the suction pump 72 being different.

[0021] For convenience, the cap 71 covers all the nozzles 10 together, and ink in the inkjet head 4 is discharged from all the nozzles 10 during suction purge. However, the present invention is not limited to this. For example, the cap 71 may have a portion covering the nozzles 10 constituting the rightmost nozzle row 9 that ejects black ink and a portion covering the nozzles 10 constituting the three leftmost nozzle rows 9 that eject color inks (yellow, cyan, and magenta inks), and either the black ink or the color ink in the inkjet head 4 may be selectively discharged during suction purge. Alternatively, for example, the cap 71 may be provided for each nozzle row 9, and ink may be discharged from the nozzles 10 for each nozzle row 9 separately during suction purge.

[0022] As shown in FIG. 2, a detection electrode 76 having a rectangular planar shape is disposed within the cap 71. The detection electrode 76 is connected to a high-voltage power supply circuit 77 via a resistor 79. A predetermined positive potential (for example, about 600 V) is applied to the detection electrode 76 by the high-voltage power supply circuit 77 during a determination drive, which will be described later. Meanwhile, the inkjet head 4 is held at the ground potential. This generates a predetermined potential difference between the inkjet head 4 and the detection electrode 76. A determination circuit 78 is connected to the detection electrode 76. The determination circuit 78 compares the potential of the signal output from the detection electrode 76 with a threshold value Vt, and outputs a signal according to the result.

[0023] More specifically, since a potential difference occurs between the inkjet head 4 and the detection electrode 76, the ink ejected from the nozzle 10 is charged. When the carriage 2 is positioned at the maintenance position and ink is ejected from the nozzle 10 toward the detection electrode 76, as shown in FIG. 3(a), the charged ink approaches the detection electrode 76, and the potential of the detection electrode 76 drops from the potential Va when the inkjet head 4 is not driven until the ink lands on the detection electrode 76, and reaches a potential Vb lower than the potential Va. Then, after the charged ink lands on the detection electrode 76, the potential of the detection electrode 76 gradually rises and returns to the potential Va. That is, the potential of the detection electrode 76 changes during the drive period Td of the inkjet head 4.

[0024] On the other hand, when ink is not ejected from the nozzle 10, as shown in FIG. 3(b), during the driving period Td of the inkjet head 4, the potential of the detection electrode 76 hardly changes from the potential Va. Therefore, a threshold value Vt (Vb < Vt < Va) is set in the determination circuit 78 to distinguish between them. Then, during the driving period Td of the inkjet head 4, the determination circuit 78 compares the maximum potential of the voltage signal output from the detection electrode 76 with the threshold value Vt, and outputs a determination signal according to the determination result. In the first embodiment, the combination of the detection electrode 76, the high-voltage power supply circuit 77, the resistor 79, and the determination circuit 78 corresponds to the "signal output unit" of the present invention. And this signal output unit outputs a determination signal according to whether the nozzle 10 is an abnormal nozzle from which ink is not ejected.

[0025] Also, here, a positive potential is applied to the detection electrode 76 by the high-voltage power supply circuit 77, but a negative potential (for example, about -600 V) may be applied to the detection electrode 76 by the high-voltage power supply circuit 77. In this case, conversely to the above, with the carriage 2 positioned at the maintenance position, when ink is ejected from the nozzle 10 toward the detection electrode 76, the charged ink approaches the detection electrode 76, and the potential of the detection electrode 76 rises from the potential Va until the ink lands on the detection electrode 76. After the ink lands on the detection electrode 76, the potential of the detection electrode 76 gradually decreases and returns to the potential Va.

[0026] <Electrical Configuration of Printer> Next, the electrical configuration of the printer 1 will be described. As shown in Fig. 4, the printer 1 is equipped with a control device 80. The control device 80 is made up of a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, a RAM (Random Access Memory) 83, a flash memory 84, an ASIC (Application Specific Integrated Circuit) 85, and the like. The control device 80 controls the operations of a carriage motor 86, an inkjet head 4, a conveying motor 87, a cap lifting mechanism 88, a suction pump 72, a high-voltage power supply circuit 77, and the like. The control device 80 also receives a determination signal from a determination circuit 78.

[0027] In addition to the components described above, the printer 1 also includes a display unit 69, an operation unit 70, and four remaining amount sensors 68 (remaining amount information acquisition means of the present invention). However, for the sake of convenience, only one remaining amount sensor 68 is shown in FIG.

[0028] The display unit 69 is, for example, a liquid crystal display provided on the housing of the printer 1. The control device 80 controls the display unit 69 to display information necessary for the operation of the printer 1. The operation unit 70 is, for example, buttons provided on the housing of the printer 1, a touch panel provided on the display unit 69, etc. A user can input signals to the control device 80 by operating the operation unit 70.

[0029] The remaining amount sensors 68 are provided in the cartridge holder 13 (see FIG. 1) for the four ink cartridges 14, one for each. The remaining amount sensors 68 are for detecting the remaining amount of ink R in the corresponding ink cartridge 14, and output a signal corresponding to the remaining amount of ink R (the "remaining amount information" of the present invention).

[0030] The control device 80 may be one in which only the CPU 81 performs various processes, one in which only the ASIC 85 performs various processes, or one in which the CPU 81 and the ASIC 85 work together to perform various processes. The control device 80 may be one in which one CPU 81 performs processes independently, or one in which multiple CPUs 81 share the processes. The control device 80 may be one in which one ASIC 85 performs processes independently, or one in which multiple ASICs 85 share the processes.

[0031] <Processing based on remaining amount sensor detection results> Next, a description will be given of the process performed by the control device 80 in the printer 1 based on a signal from the remaining amount sensor 68. When power is supplied to the printer 1, the control device 80 performs the process according to the flow in Fig. 5(a) based on a signal from the remaining amount sensor 68. The control device 80 also performs the process according to the flow in Fig. 5(a) for each of the four ink cartridges 14 individually.

[0032] 5(a) in more detail, the control device 80 waits while the remaining ink amount R indicated by the remaining ink amount sensor 68 exceeds both the first remaining amount R1 and the second remaining amount R2 (S101: NO, S102: NO). Here, the first remaining amount R1 is an amount at which recording on the recording paper P becomes impossible. The second remaining amount R2 is an amount slightly more than the first remaining amount R1.

[0033] Then, when the remaining ink amount R is equal to or less than the first remaining amount R1 (S101: YES), the control device 80 outputs an empty notification signal to the display unit 69 (S103). The empty notification signal is a signal for causing the display unit 69 to display a message or the like to notify the user that the remaining amount of ink in the ink cartridge 14 is so low that recording on the recording paper P is no longer possible.

[0034] On the other hand, when the remaining ink amount R exceeds the first remaining amount R1 (S101: NO) and is equal to or less than the second remaining amount R2 (S102: YES), the control device 80 outputs a near empty notification signal to the display unit 69 (S104). The near empty notification signal is a signal for causing the display unit 69 to display a message or the like to notify the user that the remaining amount of ink in the ink cartridge 14 is getting so low that it will soon become impossible to record on the recording paper P.

[0035] <Processing for transitioning to sleep state> Next, a process for shifting the printer 1 from the standby state to the sleep state will be described. Here, the printer 1 can selectively be in either the standby state or the sleep state. The standby state is a state in which power is supplied to each component of the printer 1 so that an operation such as recording can be started immediately. The sleep state is a state in which power supply to components other than some components including the control device 80 and the remaining amount sensor 68 among the components that were supplied with power in the standby state is stopped in order to reduce standby power. In addition, in the sleep state, the clock frequency of some components including the control device 80 and the remaining amount sensor 68 may be lower than that in the standby state. The clock frequency is, for example, a frequency that is set by the control device 80 for devices such as sensors. When the power of the printer 1 is turned on and when the sleep state described later is released, the control device 80 starts the flow of FIG. 5(b) and performs processing.

[0036] More specifically, the control device 80 waits if the time during which the printer 1 has not been operating continuously is less than a predetermined time (S201: NO). If the printer 1 has not been operating continuously for a predetermined time or more (S201: YES), the control device 80 executes sleep processing (S202). In the sleep processing, the control device 80 stops the power supply to components of the printer 1 other than the above-mentioned portion of components, thereby causing the printer 1 to transition from the standby state to the sleep state.

[0037] <Processing when receiving an inspection instruction signal> Next, the processing of the control device 80 when it receives an inspection instruction signal instructing to inspect whether the nozzle 10 is an abnormal nozzle will be described. In the first embodiment, for example, when the user inputs an inspection instruction signal by operating the operation unit 70, the control device 80 receives the inspection instruction signal. Alternatively, for example, when the printer 1 has a clock unit that keeps time, and the clock unit outputs a signal indicating that a predetermined time has arrived, the control device 80 receives this signal as an inspection instruction signal. When the control device 80 receives the inspection instruction signal, it starts the flow of FIG. 6 and performs processing.

[0038] For example, when in the sleep state, an inspection instruction signal is received by a user operating the operation unit 70, the sleep state is released based on the user's operation of the operation unit 70, and the flow of Fig. 6 is started. On the other hand, for example, when in the sleep state, a signal from the clock unit is received as an inspection instruction signal, the flow of Fig. 6 is started while remaining in the sleep state.

[0039] 6 in more detail, the control device 80 first determines whether the remaining ink amount R exceeds the first remaining amount R1 in all four color ink cartridges 14 based on the signal from the remaining ink amount sensor 68 (S301). If the remaining ink amount R in any ink cartridge 14 is equal to or less than the first remaining amount R1, the process proceeds to S311.

[0040] If the remaining ink amount R exceeds the first remaining amount R1 in all of the ink cartridges 14 of four colors (S301: YES), the control device 80 then calculates the post-inspection remaining amount Rc for all of the ink cartridges 14 of four colors (S302). The post-inspection remaining amount Rc refers to the remaining ink amount in the ink cartridge 14 after the test drive described below is performed. In S302, for example, the post-inspection remaining amount Rc is calculated by subtracting the corresponding ink discharge amount when ink is normally discharged from all nozzles 10 in the test drive from the remaining ink amount R indicated by the signal from the remaining ink amount sensor 68. Information on the discharge amount of ink of each color when ink is normally discharged from all nozzles 10 in the test drive is stored in advance in the flash memory 84.

[0041] Next, the control device 80 determines whether the post-inspection remaining amount Rc exceeds the first remaining amount R1 in all of the four color ink cartridges 14 (S303). If the post-inspection remaining amount Rc in any of the ink cartridges 14 is equal to or less than the first remaining amount R1, the process proceeds to S311.

[0042] If the post-test remaining amount Rc exceeds the first remaining amount R1 in all of the four color ink cartridges 14 (S303: YES), the control device 80 judges whether or not the device is in the sleep state (S304). For example, if the flow of Fig. 6 is started by receiving a signal from the clock unit as a test instruction signal in the sleep state, the control device 80 judges in S304 that the device is in the sleep state. Also, for example, if the flow of Fig. 6 is started by receiving a test instruction signal in the standby state, or if the flow of Fig. 6 is started by receiving a test instruction signal based on the user's operation of the operation unit 70 in the sleep state, the control device 80 judges in S304 that the device is not in the sleep state, i.e., in the standby state.

[0043] If the printer 1 is in standby mode, i.e., not in sleep mode (S304: NO), the control device 80 proceeds directly to S306, and if the printer 1 is in sleep mode (S304: YES), the control device 80 executes sleep release processing (S305) and then proceeds to S306.

[0044] In the sleep release process in S305, the power supply to each component that was stopped while the printer 1 was in the sleep state is resumed, thereby releasing the printer 1 from the sleep state and transitioning it to the standby state.

[0045] In S306, the control device 80 executes an inspection process to drive the nozzles 10 that eject ink of all colors for inspection. Driving the nozzles 10 that eject ink of all colors for inspection means driving the inkjet head 4 so that ink is ejected from each of all the nozzles 10 of the inkjet head 4 in order toward the detection electrode 76 in order to check whether each nozzle 10 is an abnormal nozzle. At this time, the control device 80 receives a determination signal from the determination circuit 78 to obtain information on whether each nozzle 10 is an abnormal nozzle.

[0046] Next, the control device 80 judges whether or not an abnormal nozzle is present based on the judgment signal output from the judgment circuit 78 during the test drive (S307). If no abnormal nozzle is present (S307: NO), the process ends.

[0047] If an abnormal nozzle is present (S307: YES), the control device 80 then calculates the post-recovery remaining amount Rd for all four color ink cartridges 14 (S308). The post-recovery remaining amount Rd refers to the amount of ink remaining in the ink cartridge 14 after a recovery operation has been performed in a recovery process, which will be described later. In S308, for example, the post-recovery remaining amount Rd is calculated by subtracting the amount of ink of the corresponding color discharged in the recovery operation, which will be described later, from the remaining ink amount R output from the remaining ink amount sensor 68 in the state after the test drive has been performed in S306. Information on the amount of ink discharged for each color in the recovery operation is stored in advance in the flash memory 84.

[0048] Next, the control device 80 determines whether the post-recovery remaining amount Rd exceeds the first remaining amount R1 in all four color ink cartridges 14 (S309). If the post-recovery remaining amount Rd is equal to or less than the first remaining amount R1 in any of the ink cartridges 14, proceed to S311.

[0049] If the post-recovery remaining amount Rd exceeds the first remaining amount R1 in all of the four color ink cartridges 14 (S309: YES), the control device 80 executes a recovery process (S310). In S310, as a recovery operation, the control device 80 controls the carriage motor 86, the cap lifting mechanism 88, the suction pump 72, etc. to perform suction purging, and further causes the inkjet head 4 to perform flushing to discharge ink from the multiple nozzles 10.

[0050] In the first embodiment, the maintenance unit 8 that performs the suction purging and the inkjet head 4 that performs the flushing correspond to the "recovery means" of the present invention.

[0051] In S311, the control device 80 outputs an ink shortage notification signal to the display unit 69. The ink shortage notification signal is a signal for causing the display unit 69 to display a message or the like to notify the user that ink is insufficient.

[0052] In the first embodiment, of any two of the four colors of ink, one of the colors corresponds to the "liquid" and "first liquid" of the present invention, and the other color corresponds to the "second liquid" of the present invention. Furthermore, the nozzle 10 that ejects the ink of one of the colors corresponds to the "nozzle" and "first nozzle" of the present invention, and the nozzle 10 that ejects the ink of the other color corresponds to the "second nozzle" of the present invention. Furthermore, the ink cartridge 14 that stores the ink of one of the colors corresponds to the "liquid tank" and "first liquid tank" of the present invention, and the ink cartridge 14 that stores the ink of the other color corresponds to the "second liquid tank" of the present invention.

[0053] Furthermore, the remaining ink amount R for the first liquid tank corresponds to the "remaining amount information" and "first remaining amount information" of the present invention. Furthermore, the post-inspection remaining amount Rc for the first liquid tank corresponds to the "post-inspection remaining amount" and "first post-inspection remaining amount" of the present invention. Furthermore, the remaining ink amount R and post-inspection remaining amount Rc for the second liquid tank correspond to the "second remaining amount information" and "second post-inspection remaining amount" of the present invention, respectively. Furthermore, in variant 1, the first remaining amount R1 corresponds to the "threshold value," "first threshold value," and "second threshold value" of the present invention.

[0054] <Effects> Unlike the first embodiment, if the test drive is performed when the post-test remaining amount Rc is equal to or less than the first remaining amount R1, it will be impossible to perform recording on the recording paper P, which would have been possible at least once if the test drive had not been performed before the ink remaining amount R was equal to or less than the first remaining amount R1. In this case, there is a risk that the ink consumed by the test drive will be wasted. Therefore, in the first embodiment, the post-test remaining amount Rc is calculated before the test drive, and the test drive is not performed when the post-test remaining amount Rc is equal to or less than the first remaining amount R1. This makes it possible to reduce wasteful consumption of ink.

[0055] Furthermore, in the first embodiment, if the post-test remaining amount Rc of any of the four ink cartridges 14 is equal to or less than the first remaining amount R1, the nozzles 10 corresponding to all of the ink cartridges 14 are not driven for testing. This makes it possible to reduce unnecessary consumption of ink.

[0056] Also, unlike the first embodiment, if a recovery operation is performed when the post-recovery remaining amount Rd is equal to or less than the first remaining amount R1, it will be impossible to perform recording on the recording paper P, which would have been possible at least once if the test drive had not been performed before the ink remaining amount R was equal to or less than the first remaining amount R1. In this case, there is a risk that the ink consumed by the recovery operation will be wasted. Therefore, in the first embodiment, the post-recovery remaining amount Rd is calculated before the recovery operation, and the recovery operation is not performed if the post-recovery remaining amount Rd is equal to or less than the first remaining amount R1. This makes it possible to reduce unnecessary ink consumption.

[0057] Furthermore, in the first embodiment, once the post-test remaining amount Rc becomes equal to or less than the first remaining amount, the state in which the post-test remaining amount Rc becomes equal to or less than the first remaining amount R1, i.e., the state in which the test drive is not performed even if the test instruction signal is received, continues unless the ink cartridge 14 is replaced and the ink remaining amount R increases. Therefore, in the first embodiment, if the post-test remaining amount Rc exceeds the threshold value when the test instruction signal is received in the sleep state, the sleep state is released and the test drive is performed. On the other hand, if the post-test remaining amount Rc becomes equal to or less than the threshold value, the sleep state is not released. This makes it possible to prevent the sleep state from being released unnecessarily.

[0058] [Second embodiment] Next, a second preferred embodiment of the present invention will be described. The second embodiment also relates to a printer 1 similar to the first embodiment.

[0059] In the second embodiment, when power is being supplied to the printer 1, the control device 80 executes processing in accordance with the flow of FIG. 7, thereby causing regular maintenance to be performed.

[0060] More specifically, if the remaining ink amount R indicated by the four remaining ink sensors 68 corresponding to the four ink cartridges 14 exceeds a fourth remaining amount R4 (the "threshold amount" of the present invention) (S401: YES), the control device 80 sets the maintenance cycle T to the first cycle T1 (the "first cycle" of the present invention) (S402) and proceeds to S404. Here, the fourth remaining amount R4 is, for example, an amount of remaining ink that is greater than the second remaining amount R2 of the first embodiment.

[0061] On the other hand, if the remaining ink level R indicated by the remaining ink sensor 68 corresponding to any of the ink cartridges 14 is equal to or less than the fourth remaining level R4 (S401: NO), the maintenance cycle T is set to a second cycle T2 (the "second cycle" of the present invention) that is longer than the first cycle T1 (S403), and the process proceeds to S404.

[0062] In S404, it is determined whether or not the maintenance period T has elapsed since the previous inspection drive. If the maintenance period T has not elapsed since the previous inspection drive (S404: NO), the process returns to S401.

[0063] Then, when the maintenance period T has elapsed since the previous test drive (S404: YES), the control device 80 executes a test process to perform test drive on the nozzles 10 that eject ink of all colors, similar to S306 (S405). Then, based on the determination signal output from the determination circuit 78 during the test process of S405, it is determined whether or not there is an abnormal nozzle (S406).

[0064] If no abnormal nozzle is present (S407: NO), the process returns to S401. If an abnormal nozzle is present (S407: YES), the control device 80 executes the same recovery process as in S310 (S408) and returns to S401.

[0065] <Effects> In the second embodiment, when the remaining amount of ink R in the ink cartridge 14 exceeds the fourth remaining amount R4 and there is sufficient ink in the ink cartridge 14, regular maintenance is performed in a relatively short first cycle T1. This makes it possible to recover an abnormal nozzle as quickly as possible when a nozzle 10 becomes abnormal. On the other hand, when the remaining amount of ink in the ink cartridge 14 is equal to or less than the fourth remaining amount R4 and there is not enough ink in the ink cartridge 14, regular maintenance is performed in a second cycle T2 that is longer than the first cycle T1. This makes it possible to reduce the consumption of ink due to regular maintenance.

[0066] [Variations] Although the preferred first and second embodiments of the present invention have been described above, the present invention is not limited to the above-described first and second embodiments, and various modifications are possible within the scope of the claims.

[0067] In the first embodiment, when the post-test remaining amount Rc in all four ink cartridges 14 exceeds the first remaining amount R1, the nozzles 10 that eject ink of each color are driven for testing. Also, when the post-recovery remaining amount Rd in all four ink cartridges 14 exceeds the first remaining amount R1, a recovery operation is performed to discharge ink from the nozzles 10 that eject ink of each color. However, this is not limited to this.

[0068] In the first modified example, although not shown in the drawings, a cap 71 is provided for each nozzle row 9, so that ink can be discharged from the nozzles 10 for each nozzle row 9 individually during suction purge. In addition, a detection electrode 76 (see FIG. 2) is disposed on each cap 71.

[0069] In the first modification, when the control device 80 receives an inspection command signal, it performs processing according to the flow of Fig. 8. More specifically, the control device 80 sets one of the four ink colors as a target color (S501). If the remaining ink amount R in the ink cartridge 14 that stores the ink of the target color is equal to or less than the first remaining amount R1 (S502: NO), the process proceeds to S510.

[0070] On the other hand, if the remaining ink amount R in the ink cartridge 14 that stores the target color ink exceeds the first remaining amount R1 (S502: YES), the control device 80 calculates the post-inspection remaining amount Rc for that ink cartridge 14 (S503). Then, if the post-inspection remaining amount Rc calculated in S503 is equal to or less than the first remaining amount R1 (S504: NO), the process proceeds to S510.

[0071] If the post-test remaining amount Rc calculated in S503 exceeds the first remaining amount R1 (S504: YES), the control device 80 then executes a test process for the nozzles 10 that eject the ink of the target color (S505). In the test process of S505, the control device 80 causes the inkjet head 4 to perform a test drive for the nozzles 10 that eject the ink of the target color. Performing a test drive for the nozzles 10 that eject the ink of the target color means driving the inkjet head 4 so as to eject ink toward the detection electrode 76, in order, from each of the multiple nozzles 10 that eject the ink of the target color.

[0072] Next, based on the determination signal received from the determination circuit 78 when the test drive was performed in S505, it is determined whether or not there is an abnormal nozzle among the nozzles 10 that eject the ink of the target color (S506). If there is no abnormal nozzle (S506: NO), proceed to S511.

[0073] If an abnormal nozzle is present (S506: YES), the control device 80 then calculates the post-recovery remaining amount Rd for the ink cartridge 14 that stores the ink of the target color (S507). If the post-recovery remaining amount Rd calculated in S507 is equal to or less than the first remaining amount R1, the process proceeds to S510. If the post-recovery remaining amount Rd calculated in S507 exceeds the first remaining amount R1 (S508: YES), the control device 80 stores recovery flag information indicating that recovery of the abnormal nozzle is necessary in the flash memory 84 (S509).

[0074] In S510, the control device 80 outputs an ink shortage notification signal, similar to S310. After the process of S509 or S510, the process proceeds to S511.

[0075] In S511, it is determined whether or not the inspection process has been completed for the nozzles 10 that eject ink of all colors (black, yellow, cyan, magenta). If the inspection process has not been completed for the nozzles 10 that eject ink of any color (S511: NO), the control device 80 changes the target color to a color for which the inspection process has not been completed (S512) and returns to S502.

[0076] Then, when the inspection process is completed for the nozzles 10 ejecting ink of all colors (S511: YES), recovery process is executed for the colors whose recovery flag information is stored in the flash memory 84 (S513). More specifically, the control device 80 performs suction purging and flushing to discharge ink from the nozzles 10 ejecting ink of the target color.

[0077] In the first modification, the nozzles 10 corresponding to the ink cartridges 14 whose post-inspection remaining amount Rc is equal to or less than the first remaining amount R1 are not driven for inspection, thereby reducing wasteful consumption of ink. On the other hand, for the nozzles 10 corresponding to the ink cartridges 14 whose post-inspection remaining amount Rc exceeds the first remaining amount R1, the nozzles 10 are driven for inspection, thereby making it possible to obtain information as to whether or not they are abnormal nozzles.

[0078] In the second modification, similarly to the first modification, a cap 71 is provided for each nozzle row 9, so that ink can be discharged from the nozzles 10 for each nozzle row 9 individually during suction purge. In addition, a detection electrode 76 (see FIG. 2) is disposed on each cap 71.

[0079] In Modification 2, when the control device 80 receives an inspection command signal, it performs processing in accordance with the flow in Fig. 9. More specifically, the control device 80 executes the processes of S501 and S502, similar to Modification 1. In Modification 2, if the remaining ink amount R exceeds the first remaining amount R1 (S502: YES), the control device 80 calculates the post-inspection remaining amount Rc and the post-recovery remaining amount Rd for the ink cartridge 14 that stores the ink of the target color (S601).

[0080] Then, if the post-recovery remaining amount Rd calculated in S601 exceeds the first remaining amount R1 (S602: YES), an inspection process similar to S505 in Modification 1 is executed (S603), and it is determined whether or not an abnormal nozzle exists based on the determination signal output from the determination circuit 78 (S604). If no abnormal nozzle exists (S604: NO), the process proceeds to S511 as in Modification 1. If an abnormal nozzle exists (S604: YES), the process proceeds to S509 as in Modification 1. The processes from S509 and S511 onwards are the same as in Modification 1.

[0081] If the post-recovery remaining amount Rd calculated in S601 is equal to or less than the first remaining amount R1 (S602: NO), the control device 80 then determines whether or not the post-inspection remaining amount Rc calculated in S601 exceeds the first remaining amount R1 (S605). If the post-inspection remaining amount Rc calculated in S601 is equal to or less than the first remaining amount R1 (S605: NO), the process proceeds to S510 as in Modification Example 1. If the post-inspection remaining amount Rc calculated in S601 exceeds the first remaining amount R1 (S605: YES), the control device 80 executes an inspection process similar to S603 (S606) and determines whether or not an abnormal nozzle exists based on the determination signal output from the determination circuit 78 (S607).

[0082] If there is no abnormal nozzle (S607: NO), the process proceeds to S511. If there is an abnormal nozzle (S607: YES), the control device 80 outputs an abnormality notification signal (S608) and proceeds to S511. The abnormality notification signal is a signal that causes a message or the like to be displayed on the display unit 69 to notify the user that there is an abnormal nozzle among the nozzles 10 that eject ink corresponding to the target color.

[0083] Unlike the second modification, if the inspection drive and recovery operation are performed when the post-recovery remaining amount Rd is equal to or less than the first remaining amount R1, it will become impossible to perform recording on the recording paper P, which would have been possible at least once if the inspection drive and recovery operation had not been performed before the remaining amount of ink in the ink cartridge 14 became equal to or less than the first remaining amount R1. In this case, there is a risk that the ink consumed by the inspection drive and recovery operation will be wasted.

[0084] Therefore, in the second modification, when the post-recovery remaining amount Rd is equal to or less than the first remaining amount R1, the test drive and the recovery operation are not performed, thereby making it possible to prevent unnecessary consumption of ink.

[0085] However, even if the post-recovery remaining amount Rd is equal to or less than the first remaining amount R1, if the post-test remaining amount Rc exceeds the first remaining amount R1, the test drive is performed and the presence of an abnormal nozzle is notified based on the judgment signal. This allows the user to, for example, determine whether or not there is an abnormal nozzle and select whether or not to perform a recovery operation. In this case, it is possible to prevent the recovery operation from being performed unintentionally by the user, thereby preventing ink from being wasted.

[0086] In addition, in the second modification, even if the post-recovery remaining amount Rd is equal to or less than the first remaining amount R1, if the post-recovery remaining amount Rd exceeds the first remaining amount R1, the inspection process is executed, and if an abnormal nozzle is present, an abnormality notification signal is output, but this is not limited to this. For example, in the second modification, in S601, only the post-recovery remaining amount Rd may be calculated, and if the post-recovery remaining amount Rd is equal to or less than the first remaining amount R1, an ink shortage notification signal may be output in all cases.

[0087] In addition, in the first embodiment, whether or not to perform the inspection process is determined based on whether the post-inspection remaining amount Rc exceeds the first remaining amount R1, and whether or not to perform the recovery process is determined based on whether the post-recovery remaining amount Rd exceeds the first remaining amount R1, but this is not limited to this.

[0088] In the third modification, the control device 80 performs processing according to the flow of Fig. 10 instead of the flow of Fig. 6. In the flow of Fig. 10, S301, S303, and S309 in the flow of Fig. 6 are replaced with S701, S702, and S703, respectively.

[0089] In S701, it is determined whether the remaining ink amount R in the ink cartridge 14 exceeds the second remaining amount R2. In S702, it is determined whether the post-test remaining amount Rc exceeds the second remaining amount R2. In S703, it is determined whether the post-recovery remaining amount Rd exceeds the second remaining amount R2.

[0090] In the third modification, the test drive is not performed if the post-test remaining amount Rc is equal to or less than the second remaining amount R2. This makes it possible to prevent unnecessary consumption of ink due to the test drive in cases where the ink remaining amount R in the ink cartridge 14 would be equal to or less than the second remaining amount R2 if the test drive were performed.

[0091] In the fourth modification, the control device 80 performs processing according to the flow of Fig. 11 instead of the flow of Fig. 6. In the flow of Fig. 11, S301, S303, and S309 in the flow of Fig. 6 are replaced with S801, S802, and S803, respectively.

[0092] In S801, it is determined whether the remaining ink amount R in the ink cartridge 14 exceeds the third remaining amount R3. In S802, it is determined whether the post-inspection remaining amount Rc exceeds the third remaining amount R3. In S803, it is determined whether the post-recovery remaining amount Rd exceeds the third remaining amount R3.

[0093] In the fourth modification, the test drive is not performed if the post-test remaining amount Rc is equal to or less than the third remaining amount R3. This makes it possible to prevent unnecessary consumption of ink due to the test drive in cases where the remaining ink amount R in the ink cartridge 14 would be equal to or less than the third remaining amount R3 if the test drive were performed.

[0094] In the above example, the threshold value for comparing the remaining ink amount R, the post-inspection remaining amount Rc, and the post-recovery remaining amount Rd to determine which is larger is common to all four colors of ink, but this is not limiting. For example, the threshold value for comparing the remaining ink amount R, the post-inspection remaining amount Rc, and the post-recovery remaining amount Rd to determine which is larger may be set individually for each of the four colors of ink.

[0095] Furthermore, in the first embodiment, when the control device 80 receives a determination signal in the sleep state, it calculates the post-inspection remaining amount Rc. Then, if the post-inspection remaining amount Rc exceeds the first remaining amount in all four ink cartridges 14, the sleep state is cancelled. On the other hand, if the post-inspection remaining amount Rc in any of the ink cartridges 14 is equal to or less than the first remaining amount R1, the sleep state is not cancelled. However, this is not limited to the above.

[0096] For example, if the post-test remaining amount Rc of any of the ink cartridges 14 calculated when the determination signal is received while not in the sleep state is equal to or less than the first remaining amount R1, non-cancel flag information indicating that the sleep state should not be cancelled may be stored in the flash memory 84. Then, when the control device 80 receives the determination signal while in the sleep state, if no non-cancel flag information is stored in the flash memory 84, the sleep state may be cancelled and the test drive may be performed. On the other hand, if non-cancel flag information is stored in the flash memory 84, the sleep state may not be cancelled.

[0097] Alternatively, for example, when the determination signal is received while the device is not in the sleep state, the device may cancel the sleep state regardless of the post-test remaining capacity Rc.

[0098] In the first embodiment and the like, the inspection drive is performed when the post-inspection remaining amount Rc exceeds a threshold value, and the recovery process is executed when an abnormal nozzle exists and the post-recovery remaining amount Rd exceeds a threshold value, but this is not limited to the above. For example, the inspection drive may be performed when the post-inspection remaining amount Rc exceeds a threshold value, and the recovery process may be executed even when an abnormal nozzle exists and the post-recovery remaining amount Rd is equal to or less than the threshold value. Alternatively, for example, the inspection drive may be performed when the post-inspection remaining amount Rc exceeds a threshold value, and the user may select whether or not to execute the recovery process when an abnormal nozzle exists and the post-recovery remaining amount Rd is equal to or less than the threshold value.

[0099] In addition, in the second embodiment, whether regular maintenance is performed in the first cycle T1 or the second cycle T2 is switched based on whether the remaining ink amount R exceeds the second remaining ink amount R2, but this is not limited to this.

[0100] For example, when the remaining ink amount R exceeds the second remaining amount R2, regular maintenance may be performed every time the number of sheets recorded since the previous regular maintenance reaches a first number, and when the remaining ink amount R is equal to or less than the second remaining amount R2, regular maintenance may be performed every time the number of sheets recorded since the previous regular maintenance reaches a second number that is greater than the first number. In this case, the period until the number of sheets recorded since the previous regular maintenance reaches the first number corresponds to the "first cycle" of the present invention, and the period until the number of sheets recorded since the previous regular maintenance reaches the second number corresponds to the "second cycle" of the present invention.

[0101] In addition, the threshold value of the remaining ink amount R that serves as the criterion for switching between performing regular maintenance in the first cycle and performing regular maintenance in the second cycle may be a threshold value that is greater than the first remaining amount R1 and less than the second remaining amount R2, or a threshold value that is greater than the second remaining amount R2.

[0102] Also, in the above example, the remaining amount of ink in the ink cartridge 14 is detected based on a signal from the remaining amount sensor 68, but this is not limited to this. For example, information on the initial value of the remaining amount of ink in the ink cartridge 14 may be stored in the flash memory 84, and the amount of ink consumed may be calculated by counting the number of times ink is ejected from each nozzle 10 and the number of times suction purging is performed, and the remaining amount of ink in the ink cartridge 14 may be calculated based on the initial value and the amount of ink consumed. In this case, the control device 80 that calculates the amount of ink consumed also serves as the "remaining amount information acquisition means" of the present invention.

[0103] In the first and second embodiments, the test drive is performed on all the nozzles 10 of the inkjet head 4, but the present invention is not limited to this. For example, the test drive may be performed on only some of the nozzles 10 of the inkjet head 4, such as every other nozzle 10 in each nozzle row 9, and the remaining nozzles 10 may be determined to be abnormal or not based on the determination signal output from the determination circuit 78 during the test drive.

[0104] Similarly, in variants 1, 2, etc., test drive may be performed on only some of the multiple nozzles 10 that eject the target color of ink, and for the other nozzles 10, it may be estimated whether they are abnormal or not based on the judgment signal output from the judgment circuit 78 during the test drive.

[0105] Furthermore, in the first and second embodiments, the judgment circuit 78 outputs a signal indicating whether or not a nozzle is abnormal, depending on the potential of the detection electrode 76 when ink is ejected from the nozzle 10 toward the detection electrode 76, but this is not limited to this.

[0106] For example, a detection electrode extending in the vertical direction may be disposed, and a determination circuit may output a signal indicating whether or not the nozzle is abnormal depending on the potential of the detection electrode when ink is ejected from the nozzle 10 so as to pass through a region facing the detection electrode. Alternatively, an optical sensor (the "signal output unit" of the present invention) may be provided to detect ink ejected from the nozzle 10, and the optical sensor may output a signal indicating whether or not the nozzle is abnormal.

[0107] Alternatively, for example, as described in Patent Gazette No. 4929699, a voltage detection circuit (the "signal output section" of the present invention) that detects the change in voltage when ink is ejected from the nozzles can be connected to a plate on which the nozzles of the inkjet head are formed, and a signal indicating whether or not the nozzle is abnormal can be output from the voltage detection circuit to the control device 80.

[0108] Alternatively, for example, the substrate of the inkjet head may be provided with a temperature detection element (the "signal output unit" of the present invention) as described in Japanese Patent No. 6231759. Then, after applying a first applied voltage to drive the heater for ejecting ink, a second applied voltage is applied to drive the heater so that ink is not ejected, and a signal is output in accordance with whether the nozzle 10 is an abnormal nozzle or not based on the change in temperature detected by the temperature detection element during the period from when the second applied voltage is applied until a predetermined time has elapsed.

[0109] In the above example, the nozzle 10 from which ink is not ejected is determined to be an abnormal nozzle, but this is not limited to the above. For example, a signal output unit may be provided that outputs a signal depending on whether the direction of ink ejection from the nozzle 10 is normal or not, and a nozzle 10 with an abnormality in the ejection direction may be determined to be an abnormal nozzle based on the signal from this signal output unit.

[0110] In the above example, the recovery operation includes suction purging and flushing, but the recovery operation is not limited to this. Only one of the suction purging and flushing may be performed as the recovery operation.

[0111] Furthermore, when purging is performed as a recovery operation, the purging is not limited to a suction purging. For example, a pressure pump may be provided in the middle of the tube 15 that connects the subtank 3 and the ink cartridge 14. Alternatively, a pressure pump connected to the ink cartridge may be provided in the printer. Then, with the nozzles 10 covered with the caps 71, the pressure pump may be driven to pressurize the ink in the inkjet head 4 and discharge the ink in the inkjet head 4 from the nozzles 10, thereby performing a so-called pressure purging.

[0112] Furthermore, in the recovery process, both suction by the suction pump 72 and pressurization by the pressure pump may be performed.

[0113] In the above example, ink is supplied to the inkjet head 4 from the removably mounted ink cartridge 14, but this is not limiting. For example, the printer may have an ink tank (the "liquid tank" of the present invention) that is fixed to the housing and has an ink supply port.

[0114] In the above, an example has been described in which the present invention is applied to a printer equipped with a so-called serial head that ejects ink from multiple nozzles while moving in the scanning direction together with the carriage, but the present invention is not limited to this. For example, the present invention can also be applied to a printer equipped with a so-called line head that extends across the entire length of the recording paper P in the scanning direction.

[0115] In the above, an example of applying the present invention to a printer that ejects ink from nozzles to perform recording on recording paper P has been described, but the present invention is not limited to this. The present invention can also be applied to printers that record images on recording media other than recording paper, such as T-shirts, sheets for outdoor advertising, cases for mobile terminals such as smartphones, cardboard, and resin members. The present invention can also be applied to liquid ejection devices that eject liquids other than ink, such as liquid resins and metals. [Explanation of symbols]

[0116] 1. Printer 4 Inkjet head 8 Maintenance Unit 10 Nozzles 68 Remaining amount sensor 72 Suction Pump 76 Detection electrode 77 High Voltage Power Supply Circuit 78 Judgment circuit 79 Resistance 80 Control device 84 Flash Memory

Claims

1. a liquid ejection head having a nozzle for ejecting liquid; a liquid tank that stores liquid to be supplied to the liquid ejection head; a remaining amount information acquiring means for acquiring remaining amount information indicating a remaining amount of liquid in the liquid tank; a signal output unit that outputs a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; A recovery means for performing a recovery operation to discharge liquid from the nozzle; A control device, The control device includes: receiving an inspection instruction signal instructing to inspect whether the nozzle is an abnormal nozzle, and when the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds a threshold value, calculating a post-inspection remaining amount, which is the remaining amount of liquid in the liquid tank after the inspection drive when the inspection drive is performed on the liquid ejection head, based on the remaining amount information; If the post-inspection remaining amount exceeds the threshold value, the liquid ejection head is driven for inspection; When the post-inspection remaining amount is equal to or less than the threshold value, the liquid ejection head is not driven for inspection, When the determination signal output from the signal output unit indicates that the abnormal nozzle is present, calculating a post-recovery remaining amount, which is the amount of liquid remaining in the liquid tank after the recovery operation is performed by the recovery means; When the remaining amount after recovery exceeds the threshold value, the recovery means is caused to perform the recovery operation; The liquid ejection apparatus is characterized in that, when the post-restoration remaining amount is equal to or less than the threshold value, the recovery unit is not caused to perform the recovery operation.

2. a liquid ejection head having, as nozzles for ejecting liquid, a first nozzle for ejecting a first liquid, and a second nozzle different from the first nozzle for ejecting a second liquid of a different type from the first liquid; a first liquid tank that stores the first liquid to be supplied to the liquid ejection head; and a second liquid tank that is separate from the first liquid tank and stores the second liquid to be supplied to the liquid ejection head; a remaining amount information acquiring means for acquiring first remaining amount information indicating a remaining amount of the first liquid in the first liquid tank and second remaining amount information indicating a remaining amount of the second liquid in the second liquid tank; a signal output unit that outputs a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; A control device, The control device includes: when an inspection instruction signal is received instructing to inspect whether the nozzle is the abnormal nozzle, and the remaining amount of the first liquid in the liquid tank indicated by the first remaining amount information exceeds a first threshold, and the remaining amount of the second liquid in the other liquid tank indicated by the second remaining amount information exceeds a second threshold, calculating a first post-inspection remaining amount, which is the remaining amount of the first liquid in the first liquid tank after the inspection drive in a case where the inspection drive is performed on the liquid ejection head, based on the first remaining amount information; calculating a second post-inspection remaining amount, which is the remaining amount of the second liquid in the second liquid tank after the inspection drive in a case where the inspection drive is performed on the liquid ejection head, based on the second remaining amount information; when the first post-inspection remaining amount exceeds the first threshold value and the second post-inspection remaining amount exceeds the second threshold value, driving the liquid ejection head for inspection for each of the first nozzle and the second nozzle; A liquid ejection device characterized in that when the remaining amount after the first inspection is equal to or less than the first threshold value, or when the remaining amount after the second inspection is equal to or less than the second threshold value, the liquid ejection head is not driven for the inspection for either the first nozzle or the second nozzle.

3. a liquid ejection head having a nozzle for ejecting liquid; a liquid tank that stores liquid to be supplied to the liquid ejection head; a remaining amount information acquiring means for acquiring remaining amount information indicating a remaining amount of liquid in the liquid tank; a signal output unit that outputs a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; A control device, The control device includes: receiving an inspection instruction signal instructing to inspect whether the nozzle is an abnormal nozzle, and when the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds a threshold value, calculating a post-inspection remaining amount, which is the remaining amount of liquid in the liquid tank after the inspection drive when the inspection drive is performed on the liquid ejection head, based on the remaining amount information; If the post-inspection remaining amount exceeds the threshold value, the liquid ejection head is driven for inspection; When the post-inspection remaining amount is equal to or less than the threshold value, the liquid ejection head is not driven for inspection, When the determination signal is received in the sleep state, If the post-inspection remaining amount exceeds the threshold value, canceling the sleep state and causing the liquid ejection head to perform the inspection drive; If the post-inspection remaining amount is equal to or less than the threshold value, The liquid ejection device is characterized in that the sleep state is not cancelled.

4. a liquid ejection head having a nozzle for ejecting liquid; a liquid tank that stores liquid to be supplied to the liquid ejection head; a remaining amount information acquiring means for acquiring remaining amount information indicating a remaining amount of liquid in the liquid tank; a signal output unit that outputs a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; A control device, The control device includes: receiving an inspection instruction signal instructing to inspect whether the nozzle is an abnormal nozzle, and when the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds a threshold value, calculating a post-inspection remaining amount, which is the remaining amount of liquid in the liquid tank after the inspection drive when the inspection drive is performed on the liquid ejection head, based on the remaining amount information; If the post-inspection remaining amount exceeds the threshold value, the liquid ejection head is driven for inspection; When the post-inspection remaining amount is equal to or less than the threshold value, the liquid ejection head is not driven for inspection, outputting a notification signal for notifying that the liquid ejection head is no longer able to eject the liquid from the nozzles onto the ejection receiving medium when the remaining amount of liquid in the liquid tank becomes equal to or less than a first remaining amount; The liquid ejection apparatus according to claim 1, wherein the threshold value is the first remaining amount.

5. a liquid ejection head having a nozzle for ejecting liquid; a liquid tank that stores liquid to be supplied to the liquid ejection head; a remaining amount information acquiring means for acquiring remaining amount information indicating a remaining amount of liquid in the liquid tank; a signal output unit that outputs a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; A control device, The control device includes: receiving an inspection instruction signal instructing to inspect whether the nozzle is an abnormal nozzle, and when the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds a threshold value, calculating a post-inspection remaining amount, which is the remaining amount of liquid in the liquid tank after the inspection drive when the inspection drive is performed on the liquid ejection head, based on the remaining amount information; If the post-inspection remaining amount exceeds the threshold value, the liquid ejection head is driven for inspection; When the post-inspection remaining amount is equal to or less than the threshold value, the liquid ejection head is not driven for inspection, when the remaining amount of liquid in the liquid tank becomes equal to or less than a second remaining amount that is greater than a first remaining amount at which the liquid cannot be ejected from the nozzles in the liquid ejection head to the ejection receiving medium, outputting a notification signal for notifying that the remaining amount of liquid in the liquid tank is low; The liquid ejection apparatus according to claim 1, wherein the threshold value is the second remaining amount.

6. a liquid ejection head having a nozzle for ejecting liquid; a liquid tank that stores liquid to be supplied to the liquid ejection head; a remaining amount information acquiring means for acquiring remaining amount information indicating a remaining amount of liquid in the liquid tank; a signal output unit that outputs a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; A control device, The control device includes: receiving an inspection instruction signal instructing to inspect whether the nozzle is an abnormal nozzle, and when the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds a threshold value, calculating a post-inspection remaining amount, which is the remaining amount of liquid in the liquid tank after the inspection drive when the inspection drive is performed on the liquid ejection head, based on the remaining amount information; If the post-inspection remaining amount exceeds the threshold value, the liquid ejection head is driven for inspection; When the post-inspection remaining amount is equal to or less than the threshold value, the liquid ejection head is not driven for inspection, when the remaining amount of liquid in the liquid tank becomes equal to or less than a second remaining amount that is greater than a first remaining amount at which the liquid cannot be ejected from the nozzles in the liquid ejection head to the ejection receiving medium, outputting a notification signal for notifying that the remaining amount of liquid in the liquid tank is low; The liquid ejection device according to claim 1, wherein the threshold value is a third remaining amount that is greater than the second remaining amount.

7. The liquid ejection head includes: a first nozzle serving as the nozzle and configured to eject a first liquid serving as the liquid; a second nozzle that is different from the first nozzle and that ejects a second liquid that is different from the first liquid; a first liquid tank serving as the liquid tank, which stores the first liquid to be supplied to the liquid ejection head; a second liquid tank separate from the first liquid tank, the second liquid being supplied to the liquid ejection head; The remaining amount information acquisition means a first remaining amount information indicating a remaining amount of the first liquid in the first liquid tank as the remaining amount information; second remaining amount information indicating a remaining amount of the second liquid in the second liquid tank; The control device includes: When the inspection instruction signal is received, when the remaining amount of the first liquid in the liquid tank indicated by the first remaining amount information exceeds a first threshold value as the threshold value, calculate a first post-inspection remaining amount as the post-inspection remaining amount, which is the remaining amount of the first liquid in the first liquid tank after the inspection drive is performed when the liquid ejection head is caused to perform the inspection drive, based on the first remaining amount information; when the remaining amount of the second liquid in the other liquid tank indicated by the second remaining amount information exceeds a second threshold value, calculate a second post-inspection remaining amount, which is the remaining amount of the second liquid in the second liquid tank after the inspection drive is performed when the liquid ejection head is caused to perform the inspection drive, based on the second remaining amount information; When the first post-inspection remaining amount exceeds a first threshold value as the threshold value, the inspection driving is performed for the first nozzle; When the first post-inspection remaining amount is equal to or less than the first threshold value, the inspection driving is not performed for the first nozzle; When the second post-inspection remaining amount exceeds a second threshold value, the inspection driving is performed for the second nozzle; 7. The liquid ejection device according to claim 1, wherein, when the remaining amount after the second inspection is equal to or less than a second threshold value, the inspection driving is not performed for the second nozzle.

8. a liquid ejection head having a nozzle for ejecting liquid; a liquid tank that stores liquid to be supplied to the liquid ejection head; a remaining amount information acquiring means for acquiring remaining amount information indicating a remaining amount of liquid in the liquid tank; a signal output unit that outputs a determination signal indicating whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; A recovery means for performing a recovery operation to discharge liquid from the nozzle; A control device, The control device includes: receiving an inspection instruction signal instructing to inspect whether the nozzle is an abnormal nozzle, and when the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds a threshold value, a post-recovery remaining amount of liquid in the liquid tank after the recovery operation is performed when the liquid ejection head is driven for inspection and the recovery unit is caused to perform the recovery operation; When the remaining amount after recovery exceeds the threshold value, The liquid ejection head is driven for inspection, and when the determination signal output from the signal output unit indicates that the abnormal nozzle is present, the recovery means is caused to perform the recovery operation. When the remaining amount after recovery is equal to or less than the threshold value, A liquid ejection apparatus, wherein the liquid ejection head is not driven for inspection.

9. The control device includes: When the inspection instruction signal is received and the remaining amount of liquid in the liquid tank indicated by the remaining amount information exceeds the threshold value, calculating a post-inspection remaining amount, which is the amount of liquid remaining in the liquid tank after the inspection drive when the inspection drive is performed on the liquid ejection head, and the post-recovery remaining amount; Even if the post-recovery residual amount is equal to or less than the threshold, if the post-inspection residual amount exceeds the threshold, The liquid ejection head is driven for inspection, The liquid ejection device according to claim 8 , wherein a notification signal for notifying information about an abnormal nozzle is output based on the determination signal output from the signal output section.

Images