Liquid discharge device

Abstract

To provide a liquid discharge device, which is configured to reduce nozzles, for which it cannot be determined whether an abnormality occurs therein or not, as much as possible.SOLUTION: A liquid discharge device can execute a first inspection process of obtaining inspection signals that are outputted from an inspection-signal output part in a first order, for a plurality of nozzles of an inkjet head, so as to inspect whether the nozzles are abnormal nozzles or not, and a second inspection process of obtaining inspection signals that are outputted from the inspection-signal output part in a second order different from the first order, for the plurality of nozzles of the inkjet head, so as to inspect whether the nozzles are abnormal nozzles or not. When the first inspecting process is executed in the previous inspecting process (S101:YES) and when DC leak occurs in the previous inspecting process (S102: YES), the second inspecting process is executed (S104).SELECTED DRAWING: Figure 8

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 nozzles, Patent Document 1 describes a printer that performs recording by ejecting ink from nozzles. In the printer described in Patent Document 1, multiple nozzles of an inkjet head are opposed to electrodes arranged in a cap, and the inkjet head is driven to eject ink from each of the multiple nozzles toward the electrode, thereby determining whether or not a nozzle is abnormal. If a leak occurs between the inkjet head and the electrode while determining whether or not a nozzle is abnormal, the determination of whether or not a nozzle is abnormal is stopped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-16023 Summary of the Invention [Problem to be solved by the invention]

[0004] In the printer of Patent Document 1, if a leak occurs while a determination is being made as to whether a nozzle is abnormal, the nozzle that was scheduled to be subsequently determined as abnormal will not be determined as abnormal.

[0005] An object of the present invention is to provide a liquid ejection device that can minimize the number of nozzles for which it is not possible to determine whether or not there is an abnormality. [Means for solving the problem]

[0006] The liquid ejection device of the present invention comprises a head having a plurality of nozzles, an inspection signal output unit having an electrode and outputting an inspection signal corresponding to an electrical change in the electrode when the head is driven to eject liquid from the nozzle toward the electrode, and a control unit, wherein the control unit drives the head to eject liquid from each of the plurality of nozzles in turn toward the electrode, acquires the inspection signal output from the inspection signal output unit, and performs an inspection process to inspect whether there is an abnormality in the ejection of liquid from the nozzle based on the acquired inspection signal, and in the inspection process, is capable of performing a first inspection process to acquire the inspection signal for each of the plurality of nozzles in a first order, and a second inspection process to acquire the inspection signal for each of the plurality of nozzles in a second order different from the first order. [Effects of the Invention]

[0007] According to the present invention, the test process can be performed by executing a first test process that acquires test signals for each of the plurality of nozzles in a first order, and a second test process that acquires test signals for each of the plurality of nozzles in a second order. By executing either the first test process or the second test process depending on the conditions in the test process, the test signals for each of the plurality of nozzles can be acquired in different orders. As a result, when the test process is repeated, test signals can be acquired evenly for the plurality of nozzles, minimizing the number of nozzles from which test signals are not acquired. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. [Figure 2] 4A and 4B are diagrams for explaining electrodes and the like arranged inside the cap. [Figure 3] FIG. 2 is a block diagram showing the electrical configuration of the printer. [Figure 4] FIG. 2 is a block diagram showing the configuration of an inspection circuit. [Figure 5]FIG. 10A is a diagram for explaining the test signal when ink is ejected from the nozzle by ejection driving, and FIG. 10B is a diagram for explaining the test signal when ink is not ejected from the nozzle by ejection driving. [Figure 6] FIG. 10 is a diagram for explaining a DC leak signal. [Figure 7] FIG. 1(a) is a diagram illustrating a signal received by a latch circuit when no AC leakage occurs, FIG. 1(b) is a diagram illustrating a signal received by a latch circuit when AC leakage occurs, and FIG. 1(c) is a diagram illustrating an AC leakage signal. [Figure 8] 10 is a flowchart showing a process flow when an inspection instruction signal is received. [Figure 9] 10A is a diagram for explaining the nozzle numbers, FIG. 10B is a diagram for explaining the first order, and FIG. 10C is a diagram for explaining the second order. [Figure 10] 10 is a diagram for explaining a second order in which inspection signals are acquired in order from nozzles with the least number of leaks. FIG. [Figure 11] FIG. 10 is a diagram illustrating an example of a second order in which test signals are first acquired for nozzles other than the nozzle in which a leak occurred during the previous test process. [Figure 12] FIG. 10 is a diagram illustrating an example of a second order in which a test signal is first acquired from a nozzle that was scheduled to acquire a test signal a predetermined number of times after a nozzle that experienced a leak during the previous test process. [Figure 13] FIG. 10 is a diagram for explaining the total number of leaks for each nozzle row. [Figure 14] (a) is a diagram for explaining an example of a divided area, (b) is a diagram for explaining another example of a divided area, and (c) is a diagram for explaining yet another example of a divided area. [Figure 15] FIG. 10 is a diagram illustrating an example of a second order in which test signals are acquired in order from the nozzles farthest from the nozzle in which a leak occurred during the previous test process. [Figure 16]FIG. 10 is a schematic diagram illustrating the configuration of a printer in which nozzles that eject black ink and nozzles that eject color inks are individually capped. [Figure 17] (a) is a diagram for explaining an example of a second sequence when a leak occurs in a nozzle that ejects black ink during the previous inspection process in the printer of Figure 16, and (b) is a diagram for explaining an example of a second sequence when a leak occurs in a nozzle that ejects color ink during the previous inspection process in the printer of Figure 16. [Figure 18] 10 is a flowchart showing the flow of processing when an inspection instruction signal is received in an example in which first inspection processing and second inspection processing are performed alternately regardless of the occurrence of a leak. [Figure 19] (a) is a flowchart showing the processing flow when a purge instruction signal is received, (b) is a flowchart showing the processing flow when an inspection instruction signal is received in an example in which it is determined whether the inspection signal for the nozzle closest to the lip portion or the nozzle farthest from the lip portion will be acquired first depending on the time elapsed since the purge, and (c) is a diagram for explaining the first nozzle and the second nozzle in an example in which it is determined whether the inspection signal for the nozzle closest to the lip portion or the nozzle farthest from the lip portion will be acquired first depending on the time elapsed since the purge. [Figure 20] FIG. 10 is a diagram for explaining the first and second nozzles in an example in which it is determined whether to acquire an inspection signal first from a nozzle closer to the outlet or from a nozzle farther from the outlet, depending on the time elapsed since purging. [Figure 21] (a) is a diagram for explaining the Zth order, and (b) is a flowchart showing the processing flow when an inspection instruction signal is received in an example in which the order in which the inspection signals are acquired, from the 1st to Zth orders, is determined depending on the conditions. [Figure 22] 10 is a flowchart showing a process flow when an inspection instruction signal is received in another example in which the order in which inspection signals are acquired from the first to Zth orders is determined depending on conditions. [Figure 23](a) is a flowchart showing the flow of processing performed in a printer in an example where variable Z is reset at every predetermined time, and (b) is a flowchart showing the flow of processing performed in a printer in an example where variable Z is reset every time a predetermined number of pages are printed. [Figure 24] 10A and 10B are diagrams for explaining an example of excluding nozzles with a high number of leak occurrences from targets for obtaining inspection signals. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present invention will now be described.

[0010] <Overall printer configuration> As shown in FIG. 1, the printer 1 according to this embodiment includes a carriage 2, an inkjet head 4, a platen 5, transport rollers 6 and 7, and a maintenance unit 8. In this embodiment, the printer 1 corresponds to the "liquid ejection device" of the present invention. In this embodiment, the inkjet head 4 corresponds to the "liquid ejection head" of the present invention. In this embodiment, the maintenance unit 8 corresponds to the "purge section" of the present invention.

[0011] The carriage 2 is supported by two guide rails 11 and 12 extending in the scanning direction. The carriage 2 is connected to a carriage motor 36 shown in FIG. 3 via a belt or the like (not shown). When the carriage motor 36 is driven, the carriage 2 moves in the scanning direction along the guide rails 11 and 12. In the following description, the right and left sides of the scanning direction are defined as shown in FIG. 1.

[0012] The inkjet head 4 is mounted on the carriage 2. The inkjet head 4 ejects ink from a plurality of nozzles 10 formed on its lower surface, the nozzle surface 4a. More specifically, the plurality of nozzles 10 are arranged in a transport direction perpendicular to the scanning direction to form nozzle rows 9, and on the nozzle surface 4a, four nozzle rows 9 are aligned in the scanning direction. The plurality of nozzles 10 eject black, yellow, cyan, and magenta inks, starting from the nozzles constituting the nozzle row 9 on the right side in the scanning direction. The inkjet head 4 is connected to four ink cartridges (not shown) via tubes (not shown) or the like. The four ink cartridges supply the above four colors of ink to the inkjet head 4.

[0013] The platen 5 is disposed below the inkjet head 4 and faces the multiple nozzles 10. The platen 5 extends across the entire length of the recording paper S in the scanning direction and supports the recording paper S 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 37 shown in FIG. 3 via gears (not shown). When the transport motor 37 is driven, the transport rollers 6 and 7 rotate and the recording paper S is transported in the transport direction.

[0014] The maintenance unit 8 includes a cap 21, a suction pump 22, and a waste liquid tank 23. The cap 21 is disposed to the right of the platen 5 in the scanning direction. The cap 21 has a lip portion 29. The lip portion 29 protrudes upward and extends around the entire outer edge of the cap 21. In addition, a discharge port 28 for discharging ink is provided at the downstream end in the transport direction of the portion of the cap 21 surrounded by the lip portion 29. When the carriage 2 is positioned at the maintenance position to the right of the platen 5 in the scanning direction, the multiple nozzles 10 face the portion of the cap 21 surrounded by the lip portion 29.

[0015] The cap 21 can be raised and lowered by a cap lifting mechanism 38 shown in FIG. 3. When the carriage 2 is positioned at the maintenance position so that the plurality of nozzles 10 and the cap 21 face each other, and the cap 21 is raised by the cap lifting mechanism 38, the lip portion 29 comes into close contact with the nozzle surface 4a, and the plurality of nozzles 10 are covered by the cap 21. When the cap 21 is lowered by the cap lifting mechanism 38, the plurality of nozzles 10 are uncovered by the cap 21 and are in an uncapped state. Note that the cap 21 is not limited to a configuration in which the lip portion 29 comes into close contact with the nozzle surface 4a to cover the plurality of nozzles 10. For example, the cap 21 may cover the plurality of nozzles 10 by having the lip portion 29 come into close contact with a frame (not shown) or the like that is disposed around the nozzle surface 4a of the inkjet head 4.

[0016] The suction pump 22 is a tube pump or the like, and is connected to the outlet 28 of the cap 21 and the waste liquid tank 23. In the maintenance unit 8, when the suction pump 22 is driven in the above-mentioned capped state, it is possible to perform a so-called suction purge, which discharges ink from inside the inkjet head 4 through the multiple nozzles 10. The ink discharged by the suction purge is stored in the waste liquid tank 23.

[0017] For convenience, the cap 21 has been described as covering all of the nozzles 10 collectively, and ink in the inkjet head 4 is discharged from all of the nozzles 10 during suction purging. However, this is not limiting. For example, the cap 21 may have separate portions covering the nozzles 10 constituting the rightmost nozzle row 9 that ejects black ink and the nozzles 10 constituting the three leftmost nozzle rows 9 that eject color inks, yellow, cyan, and magenta, so that either the black ink or the color ink in the inkjet head 4 can be selectively discharged during suction purging. Alternatively, for example, a separate cap 21 may be provided for each nozzle row 9, and ink can be discharged from the nozzles 10 for each nozzle row 9 individually during suction purging.

[0018] Furthermore, in the maintenance unit 8, when the suction pump 22 is driven in the uncapped state, ink accumulated in the cap 21 can be discharged from the discharge port 28 by suction purging, discharge driving (described later), or the like, thereby performing so-called idle suction. The ink discharged from the cap 21 by idle suction is also stored in the waste liquid tank 23.

[0019] 2, an electrode 26 having a rectangular planar shape is disposed within the cap 21. The electrode 26 constitutes an inspection circuit 27 shown in FIGS. 3 and 4. The inspection circuit 27 is controlled by a control unit 30 shown in FIGS. 3 and 4. In this embodiment, with the cap in the above-described state and a potential difference generated between the inkjet head 4 and the electrode 26 as described below, the inkjet head 4 is driven to eject ink from the nozzles 10. Based on the change in voltage of the electrode 26, it is possible to inspect whether ink has been ejected normally from the nozzles 10.

[0020] <Printer electrical configuration> Next, we will explain the electrical configuration of the printer 1. As shown in Figure 3, the printer 1 has a control unit 30. The control unit 30 has a CPU 31, ROM 32, RAM 33, memory 34, ASIC 35, etc. The control unit 30 controls the operations of a carriage motor 36, inkjet head 4, transport motor 37, cap lifting mechanism 38, suction pump 22, inspection circuit 27, etc. The control unit 30 also receives signals from the inspection circuit 27.

[0021] The control unit 30 may be configured such that only the CPU 31 performs various processes, or such that only the ASIC 35 performs various processes, or such that the CPU 31 and the ASIC 35 work together to perform various processes. The control unit 30 may be configured such that one CPU 31 performs processes independently, or such that multiple CPUs 31 share the processes. The control unit 30 may be configured such that one ASIC 35 performs processes independently, or such that multiple ASICs 35 share the processes.

[0022] <Inspection circuit> Next, a description will be given of the inspection circuit 27. As shown in Fig. 4, the inspection circuit 27 includes the above-mentioned electrodes 26, a voltage supply circuit 51, a high-pass filter 52, an amplifier circuit 53, a low-pass filter 54, and a latch circuit 55.

[0023] The voltage supply circuit 51 is controlled by the control unit 30 to apply a voltage to the electrode 26 , thereby generating a potential difference between the inkjet head 4 and the electrode 26 .

[0024] One end of high-pass filter 52 is connected between power supply circuit 51 and electrode 26. Amplification circuit 53 is connected to the other end of high-pass filter 52. When a voltage fluctuation occurs at electrode 26, which is located upstream of high-pass filter 52 in the voltage supply, the DC component of the voltage is removed by high-pass filter 52 downstream of high-pass filter 52 in the voltage supply. The voltage that has passed through high-pass filter 52 is amplified by amplifier circuit 53 and output as an inspection signal. As a result, the inspection signal is a signal in which the high-frequency component of the voltage of electrode 26 has been amplified.

[0025] Here, the voltage of the electrode 26 will be described when the inkjet head 4 is driven to eject ink from the nozzle 10 while in the capped state and a voltage is applied to the electrode 26 by the voltage supply circuit 51 to generate a potential difference between the inkjet head 4 and the electrode 26. When ink is ejected normally from the nozzle 10 by the ejection drive, the voltage of the electrode 26 changes. This change in voltage of the electrode 26 is rapid. On the other hand, when the amount of ink ejected from the nozzle 10 by the ejection drive is less than normal, the change in voltage of the electrode 26 is smaller than normal. Here, a less than normal amount of ink ejected from the nozzle 10 by the ejection drive also includes the case where ink is not ejected from the nozzle 10 by the ejection drive. When ink is not ejected from the nozzle 10 by the ejection drive, the voltage of the electrode 26 barely changes. For these reasons, the high-frequency component of the voltage of the electrode 26 differs depending on whether ink is ejected normally from the nozzle 10 by the ejection drive.

[0026] When ink is normally ejected from the nozzle 10 by the ejection drive, the voltage of the test signal output from the amplifier circuit 53 changes relative to V0, as shown in FIG. 5(a). V0 is, for example, a voltage close to ground potential. However, the amount of change in the voltage of the electrode 26 when ink is ejected from the nozzle 10 by the ejection drive is smaller than the amount of change in the voltage of the electrode 26 when an AC leak occurs, in which a current greater than or equal to a predetermined value temporarily flows between the inkjet head 4 and the electrode 26, as will be described later. For this reason, in this embodiment, the signal output from the high-pass filter 52 is amplified by the amplifier circuit 53 and output as the test signal.

[0027] On the other hand, when the amount of ink ejected from the nozzle 10 due to ejection drive is less than normal, as shown in Figure 5(b), the change in the voltage of the test signal output from the amplifier circuit 53 relative to V0 is smaller than when ink is ejected normally from the nozzle 10 due to ejection drive.

[0028] In this way, the test signal is a signal that indicates whether or not ink has been ejected normally from the nozzles 10 by the ejection drive.

[0029] One end of low-pass filter 54 is connected between voltage supply circuit 51 and electrode 26. Low-pass filter 54 outputs, from the other end, a signal from which high-frequency components have been removed in response to fluctuations in the voltage of electrode 26, as a DC leak signal. In other words, the DC leak signal is a signal that is mainly the direct-current component of the voltage of electrode 26.

[0030] Here, for example, if the inkjet head 4 and the electrode 26 are connected via the ink in the cap 21, a DC leak may occur, in which a current greater than or equal to a predetermined value continuously flows between the inkjet head 4 and the electrode 26. When a DC leak occurs between the inkjet head 4 and the electrode 26, the current continues to flow between the inkjet head 4 and the electrode 26, causing the voltage of the electrode 26 to decrease.

[0031] Therefore, as shown in FIG. 6, when there is no DC leak between the inkjet head 4 and the electrode 26, the magnitude |V2| of the voltage V2 of the DC leak signal output from the low-pass filter 54 is about the voltage V2a (V2a>0). When a DC leak occurs between the inkjet head 4 and the electrode 26, the magnitude |V2| of the voltage V2 of the DC leak signal output from the low-pass filter 54 becomes smaller than the voltage V2b (<V2a). Note that FIG. 6 shows a case where there is no DC leak between the inkjet head 4 and the electrode 26 until time T1, and a DC leak occurs between the inkjet head 4 and the electrode 26 from time T1.

[0032] Thus, the DC leak signal is a signal indicating whether a DC leak has occurred between the inkjet head 4 and the electrode 26.

[0033] The latch circuit 55 is connected in parallel with the amplifier circuit 53 to the other end of the high-pass filter 52. The latch circuit 55 receives, from the voltage of the electrode 26, a signal from which the DC component, that is, the high voltage component applied by the voltage supply circuit 51, has been removed by the high-pass filter 52. The latch circuit 55 is configured to output a signal when a voltage of a predetermined voltage or higher is input, and not to output a signal when a voltage lower than the predetermined voltage is input. Also, the latch circuit 55 maintains its output once it has output a signal. The output of the latch circuit 55 continues until it receives a release signal instructing the release of the output from the control unit 30.

[0034] Here, if an AC leak occurs, in which a current of a predetermined value or more temporarily flows between the inkjet head 4 and the electrode 26, for example, due to a temporary discharge occurring in the gap between the ink in the cap 21 and the nozzle surface 4a, a temporary voltage change occurs in the electrode 26. Furthermore, when an AC leak occurs between the inkjet head 4 and the electrode 26, the temporary voltage change in the electrode 26 is sudden. Therefore, the high-frequency component of the voltage of the electrode 26 differs depending on whether or not an AC leak has occurred between the inkjet head 4 and the electrode 26. Furthermore, the amount of change in the voltage of the electrode 26 at this time is greater than the amount of change in the voltage of the electrode 26 when ink is ejected from the nozzle 10 by ejection driving.

[0035] Therefore, when no AC leakage occurs between the inkjet head 4 and the electrode 26, the voltage of the signal output from the high-pass filter 52 and received by the latch circuit 55 changes very little, as shown in FIG. 7(a). Therefore, the latch circuit 55 does not output a signal. On the other hand, when AC leakage occurs between the inkjet head 4 and the electrode 26, the voltage of the signal received by the latch circuit 55 changes temporarily, as shown in FIG. 7(b). However, this voltage change lasts only a short time.

[0036] When a voltage change occurs in the signal received by the latch circuit 55 due to AC leakage between the inkjet head 4 and the electrode 26, the latch circuit 55 outputs a signal and maintains that state. As a result, the AC leakage signal output from the latch circuit 55 has a voltage of V0 when there is no AC leakage between the inkjet head 4 and the electrode 26, as shown in Fig. 7(c), for example, and a voltage of V3a (>V0) when AC leakage occurs between the inkjet head 4 and the electrode 26, and the output of that signal is maintained.

[0037] 7(b) and (c) show the case where AC leakage occurs between the inkjet head 4 and the electrode 26 at time T2. Furthermore, if AC leakage continues to occur between the inkjet head 4 and the electrode 26, the signal output from the latch circuit 55 will maintain the voltage V3a. The control unit 30 outputs a release signal when it determines that it is no longer necessary to maintain the output from the latch circuit 55, and the latch circuit 55 receives the release signal from the control unit 30. Upon receiving the release signal, the latch circuit 55 stops outputting the latch signal. Note that FIG. 7(c) shows the case where the latch circuit 55 receives the release signal at time T3, which is later than time T2.

[0038] In this way, the AC leak signal output from the latch circuit 55 is a signal that indicates whether or not AC leak has occurred between the inkjet head 4 and the electrode 26.

[0039] In this embodiment, a portion of inspection circuit 27 including electrode 26, voltage supply circuit 51, high-pass filter 52, and amplifier circuit 53 corresponds to the "inspection signal output unit" of the present invention. In this embodiment, a portion of inspection circuit 27 including electrode 26, voltage supply circuit 51, low-pass filter 54, high-pass filter 52, and latch circuit 55 corresponds to the "leak signal output unit" of the present invention. In addition, a portion of the leak signal output unit of inspection circuit 27 including electrode 26, voltage supply circuit 51, and low-pass filter 54 corresponds to the "DC leak signal output unit" of the present invention. In addition, a portion of the leak signal output unit of inspection circuit 27 including electrode 26, voltage supply circuit 51, high-pass filter 52, and latch circuit 55 corresponds to the "AC leak signal output unit" of the present invention.

[0040] <Processing when receiving an inspection instruction signal> Next, a description will be given of the flow of processing by the control unit 30 when an inspection instruction signal is received instructing to inspect the plurality of nozzles 10 of the inkjet head 4. For example, when a user operates an operation unit (not shown) of the printer 1 or a PC connected to the printer to instruct to inspect the nozzles 10, an inspection instruction signal is sent from the operation unit or PC of the printer 1, and the control unit 30 receives this inspection instruction signal. Then, when the control unit 30 receives the inspection instruction signal, it performs processing in accordance with the flowchart of FIG.

[0041] In this embodiment, the control unit 30 executes either a first inspection process or a second inspection process as the inspection process when performing processing according to the flowchart of Fig. 8. In the inspection process, the control unit 30 causes the voltage supply circuit 51 to apply a predetermined voltage to the electrodes 26, causes the inkjet head 4 to perform an ejection drive for ejecting ink from the nozzles 10 for each of the multiple nozzles 10 of the inkjet head 4, acquires an inspection signal output from the amplifier circuit 53 when the ejection drive is performed, and inspects whether or not there is an abnormality in the ejection of liquid from the nozzles 10 based on the acquired inspection signal. The difference between the first inspection process and the second inspection process will be explained in detail later.

[0042] 8 will be described in detail. First, the control unit 30 determines whether or not a first test process was executed during the previous test process (S101). If the first test process was executed during the previous test process (S101: YES), the control unit 30 determines whether or not a DC leak occurred during the previous test process (S102). If a DC leak did not occur during the previous test process (S102: NO), the control unit 30 starts the first test process (S103). If a DC leak occurred during the previous test process (S102: YES), the control unit 30 starts the second test process (S104).

[0043] If the second test process was performed during the previous test process (S101: NO), the control unit 30 determines whether or not a DC leak occurred during the previous test process (S105). If a DC leak did not occur during the previous test process (S105: NO), the control unit 30 starts the second test process (S106). If a DC leak occurred during the previous test process (S105: YES), the control unit 30 starts the first test process (S107).

[0044] After starting any of the inspection processes in S103 to S107, if neither DC leakage nor AC leakage occurs (S108: NO) and the inspection process is completed (S109: YES), the process ends. Furthermore, after starting any of the inspection processes in S103 to S107, if either DC leakage or AC leakage occurs (S108: YES) before the inspection process is completed (S109: NO), the control unit 30 stops the inspection process (S110), and the process ends. Here, stopping the inspection process means causing the voltage supply circuit 51 to stop applying a predetermined voltage to the electrode 26 and stopping subsequent ejection drive at this inspection timing.

[0045] <First inspection process and second inspection process> Next, the first and second test processes will be described. In the first and second test processes, the control unit 30 causes the voltage supply circuit 51 to apply a predetermined voltage to the electrodes 26, causes the inkjet head 4 to perform an ejection drive for ejecting ink from the nozzles 10 for each of the multiple nozzles 10 of the inkjet head 4, acquires a test signal output from the amplifier circuit 53 when the ejection drive is performed, and inspects whether or not there is an abnormality in the ejection of liquid from the nozzles 10 based on the acquired test signal. In the first test process, the test signal is acquired for each of the multiple nozzles in a first order. In the second test process, the test signal is acquired for each of the multiple nozzles in a second order different from the first order.

[0046] The first and second orders will be described. To explain the first and second orders, as shown in FIG. 9A, the inkjet head 4 has N nozzles 10, and these N nozzles 10 are assigned individual nozzle numbers "1" to "N." Specifically, the nozzles 10 constituting the nozzle row 9 on the far right side in the scanning direction are assigned nozzle numbers "1," "5," "9," ..., "N-3" in order of downstream position in the transport direction. Furthermore, the nozzles 10 constituting the nozzle row 9 second from the right in the scanning direction are assigned nozzle numbers "2," "6," "10," ..., "N-2" in order of downstream position in the transport direction. Furthermore, the nozzles 10 constituting the nozzle row 9 third from the right in the scanning direction are assigned nozzle numbers "3," "7," "11," ..., "N-1" in order of downstream position in the transport direction. Furthermore, the nozzles 10 constituting the leftmost nozzle row 9 in the scanning direction are assigned nozzle numbers "4", "8", "12", . . . "N" in order from the nozzles located downstream in the transport direction.

[0047] 9(b), the first order is the order of the nozzle numbers, i.e., the first order is an order in which the test signal is first acquired for the nozzle 10 with the nozzle number "1", and then the test signals are acquired in order for the nozzles 10 with the nozzle numbers "2", "3", ..., "N-1", and "N".

[0048] In this embodiment, as shown in FIG. 9(c), information on the number of times DC leaks have occurred is stored in the memory 34 for each nozzle 10 of the inkjet head 4. Here, among the nozzles 10 for which the number of times DC leaks have occurred is equal to or less than the first number, the nozzle 10 with the smallest nozzle number is designated as "Aa." The second order is an order in which test signals are acquired for the nozzles 10 with nozzle numbers "Aa" to "N" in the order of the nozzle numbers, and then test signals are acquired for the nozzles 10 with nozzle numbers "1" to "Aa-1" in the order of the nozzle numbers. FIG. 9(c) shows a case in which the first number is 2 and Aa is 6. In this example, the second order is an order in which test signals are acquired for the nozzles 10 with nozzle numbers "6" to "N" in the order of the nozzle numbers, and then test signals are acquired for the nozzles 10 with nozzle numbers "1" to "5" in the order of the nozzle numbers.

[0049] <Effects> In this embodiment, the inspection process can be performed in a first inspection process in which inspection signals are acquired for each of the multiple nozzles 10 in a first order, and a second inspection process in which inspection signals are acquired for each of the multiple nozzles 10 in a second order. Furthermore, in this embodiment, if a leak occurs during the first inspection process, the first inspection process is stopped, and therefore inspection signals are not acquired for nozzles 10 from which inspection signals were scheduled to be acquired thereafter. Furthermore, since there is a high possibility that a leak will occur in the same nozzles 10 in the next inspection process, performing the first inspection process in the next inspection process will result in a bias in the nozzles 10 from which inspection signals are not acquired.

[0050] Therefore, in this embodiment, if a DC leak occurs during the first test process, the second test process is executed in the next test process, changing the order of the nozzles 10 from which the test signal is acquired. This makes it possible to reduce bias in the number of nozzles 10 from which the test signal is not acquired, even if a DC leak occurs in the same nozzle 10, and minimize the number of nozzles 10 from which the test signal is not acquired.

[0051] Furthermore, if the inspection signal is always acquired for each of the multiple nozzles 10 in the same order during the inspection process, the nozzles 10 in which DC leakage occurs will be concentrated in specific nozzles, which is likely to result in significant damage to those nozzles 10.

[0052] In this embodiment, as described above, if a DC leak occurs during the first test process, the second test process is executed in the next test process, and the order of the nozzles 10 from which the test signals are acquired is changed. This makes it less likely that a specific nozzle 10 will experience a DC leak.

[0053] Furthermore, DC leaks are likely to occur due to factors in the environment surrounding the inkjet head 4. Therefore, if a DC leak occurs at a certain nozzle in the first test process, changing the order of nozzles from which test signals are acquired in the next test process increases the likelihood that a leak will occur at a nozzle that is close to the certain nozzle 10 and from which test signals are acquired before the certain nozzle 10 in the next test process. Therefore, in this embodiment, as described above, if a DC leak occurs during the first test process, the second test process is performed in the next test process, and by changing the order of nozzles 10 from which test signals are acquired, it is possible to prevent nozzles 10 from experiencing DC leaks from concentrating at a specific nozzle 10.

[0054] Furthermore, AC leaks are more likely to occur due to factors in the nozzles 10 themselves than DC leaks. Therefore, when an AC leak occurs, even if the order of the nozzles 10 from which inspection signals are acquired in the next inspection process is changed, there is a high possibility that an AC leak will occur in the same nozzles 10. In other words, even if the order of the nozzles 10 from which inspection signals are acquired in the next inspection process is changed, there is a low possibility that the effect of preventing leaks from concentrating on a specific nozzle 10 will be achieved.

[0055] Therefore, in this embodiment, even if an AC leak occurs during the first test process, if no DC leak occurs, the first test process is also executed in the next test process, and the order of the nozzles 10 from which the test signals are acquired is not changed, thereby simplifying the process.

[0056] Furthermore, in this embodiment, in the second test process, test signals are acquired for each of the multiple nozzles 10 in a second order such that test signals are acquired first for nozzles 10 that have experienced a leak a first number of times or less, other than the nozzle 10 from which a test signal was acquired first in the first test process. This increases the likelihood that a large number of nozzles 10 will be able to acquire test signals before a leak occurs in the second test process.

[0057] <Modification> Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims.

[0058] For example, the order in which the inspection signals are acquired for each of the plurality of nozzles 10 in the inspection process is not limited to that described in the above embodiment.

[0059] For example, in the above-described embodiment, the second order may be an order in which, among the nozzles 10 in which the number of occurrences of DC leaks is the first number or less, the inspection signals for the nozzles 10 other than the nozzle 10 with the smallest nozzle number are first acquired. Also, in the second order, the order in which the inspection signals for any of the nozzles 10 in which the number of occurrences of DC leaks is the first number or less and then the inspection signals for the remaining nozzles 10 are acquired may be different from the order described in the above-described embodiment.

[0060] In the first modification, the second order is an order in which the test signals are acquired in order from the nozzle 10 with the fewest number of times that a DC leak has occurred, as shown in Fig. 10. Specifically, first, the test signals are acquired for the nozzle 10 with zero number of times that a DC leak has occurred, then the test signals are acquired for the nozzle 10 with one number of times that a DC leak has occurred, and so on, and so on, for the nozzles 10 with two, three, ... number of times that a DC leak has occurred. Note that in the example of Fig. 10, for multiple nozzles 10 with the same number of times that a DC leak has occurred, the test signals are acquired in order from the nozzle 10 with the smallest nozzle number, but the test signals for these nozzles 10 may be acquired in a different order. Here, in B of Fig. 10 H (H=0, 1, 2, 3, 4, 5) is the number of nozzles 10 where the number of occurrences of DC leakage is H or less.

[0061] <Effects> In the first modification, in the second inspection process, the inspection signals are acquired for each of the plurality of nozzles 10 in a second order, such that the inspection signals are acquired in order from the nozzles 10 with the fewest leaks. This increases the likelihood that the number of nozzles 10 from which inspection signals can be acquired before a leak occurs in the second inspection process will be large.

[0062] In the second modification, as shown in Fig. 11, the second order is an order in which, assuming that the nozzle number of the nozzle 10 in which a DC leak occurred during the previous first inspection process is "Ab," inspection signals are acquired for the nozzles 10 with nozzle numbers "Ab+1" to "N" in the order of the nozzle numbers, and then inspection signals are acquired for the nozzles 10 with nozzle numbers "1" to "Ab" in the order of the nozzle numbers. Here, in Fig. 11, "◯" indicates a nozzle 10 in which a DC leak occurred during the previous first inspection process, and this shows the case where "Ab" is "8."

[0063] A nozzle 10 in which a leak has occurred is likely to have a DC leak in the next inspection process as well. In Modification 2, in the second inspection process, inspection signals are acquired for each of the multiple nozzles 10 in a second order such that inspection signals for nozzles 10 other than the nozzle 10 in which a DC leak has occurred in the first inspection process are acquired first. This increases the likelihood that inspection signals will be acquired for a large number of nozzles 10 before a leak occurs in the second inspection process.

[0064] In the second modification, the nozzle 10 in which a DC leak occurred during the previous first inspection process was designated as having the nozzle number "Ab," and the inspection signal was acquired first for the nozzle 10 with the nozzle number "Ab+1." However, inspection signals may be acquired first for nozzles 10 with nozzle numbers other than "Ab" and "Ab+1." Furthermore, the order in which the second and subsequent nozzles 10 are acquired for inspection signals may be different from that described in the second modification.

[0065] In Modification 3, as shown in FIG. 12, the second order is such that, with "Ac" representing the nozzle number of the nozzle 10 in which a DC leak occurred during the previous first inspection process, inspection signals are acquired for the nozzles 10 with nozzle numbers "Ac+5" to "N" in the order of the nozzle numbers, and then inspection signals are acquired for the nozzles 10 with nozzle numbers "1" to "Ac+4" in the order of the nozzle numbers. That is, the second order in Modification 3 is such that, with the predetermined number being 5, inspection signals are first acquired for the nozzles 10 for which inspection signals were scheduled to be acquired a predetermined number of times after the nozzles 10 in which a DC leak occurred during the first inspection process. Here, in FIG. 12, "◯" represents the nozzle 10 in which a DC leak occurred during the previous first inspection process, and "Ac" represents "4."

[0066] There is a high possibility that a leak will occur in the next inspection process for the nozzle 10 in which a DC leak has occurred and for the nozzles 10 nearby. In Variation 3, in the second inspection process, inspection signals are acquired for each of the multiple nozzles 10 in a second order such that inspection signals for the nozzles 10 that were scheduled to acquire inspection signals after a predetermined number of nozzles, two or more in the first order, of the nozzles 10 in which a DC leak has occurred in the first inspection process are acquired first. This allows inspection signals for nozzles 10 that are distant from the nozzle 10 in which a leak has occurred in the first inspection process to be acquired first in the second inspection process, increasing the possibility that inspection signals will be acquired for a large number of nozzles 10 before a leak occurs.

[0067] In Modification 3, the predetermined number is set to 5, but in Modification 3 the predetermined number may be set to 2, 3, 4, or an integer equal to or greater than 6. In addition, the order of the nozzles 10 from which the second and subsequent inspection signals are obtained may be different from the order of the nozzle numbers.

[0068] In the fourth modification, as shown in FIG. 13, the total number of times that leakage occurred during the inspection process in the nozzles 10 constituting the nozzle row 9 is calculated for each nozzle row 9, that is, for each color of ink ejected. K , D Y , D C , D M is stored in the memory 34. The total number of times D K , D Y , D C , D M may be the sum of the total number of times that DC leakage occurred and the total number of times that AC leakage occurred, or may be the sum of the number of times that DC leakage occurred, or may be the sum of the number of times that AC leakage occurred.

[0069] The second order in the fourth modification is D K , D Y , D C , D M The order is such that the nozzle row 9 corresponding to the smallest total number of times is first to acquire test signals for the plurality of nozzles 10 that make up the nozzle row 9.

[0070] Here, of any two nozzle rows 9 of the four nozzle rows 9, the plurality of nozzles 10 constituting one nozzle row 9 corresponds to the "plurality of first nozzles" of the present invention, and the plurality of nozzles 10 constituting the other nozzle row 9 corresponds to the "plurality of second nozzles" of the present invention. If the first total number of times that leakage has occurred in each of the plurality of first nozzles is less than the second total number of times that leakage has occurred in each of the plurality of second nozzles, the second order is an order in which a test signal for each of the plurality of first nozzles is acquired first, and then a test signal for each of the plurality of second nozzles is acquired. On the other hand, if the second total number is less than the first total number, the second order is an order in which a test signal for each of the plurality of second nozzles is acquired first, and then a test signal for each of the plurality of first nozzles is acquired.

[0071] Furthermore, in the second order, the order in which the test signals are acquired for the plurality of nozzles 10 constituting each nozzle row 9 may be arbitrary. For example, the test signals may be acquired for the plurality of nozzles 10 constituting each nozzle row 9 in order starting from the nozzle 10 on the downstream side in the transport direction.

[0072] Nozzles 10 that eject ink of the same color as the nozzle 10 in which the DC leak occurred are more likely to experience a leak in the next test process than nozzles 10 that eject ink of a different color. In Variation 4, in the second test process, test signals are acquired for each of the multiple nozzles 10 in a second order such that, of any two nozzle rows 9, the test signal for the nozzle 10 with the fewer total number of times is acquired first. This increases the likelihood that a large number of nozzles 10 will have test signals acquired before a leak occurs in the second test process.

[0073] In variants 5 to 7, for each of a plurality of divided regions E into which the nozzle surface 4a is divided, the total number of times that a leak occurred during the inspection process in the nozzles 10 located within the divided region E is stored in the memory 34. The total number may be the sum of the total number of times that a DC leak occurred and the total number of times that an AC leak occurred, or it may be the total number of times that a DC leak occurred, or it may be the total number of times that an AC leak occurred.

[0074] In Modification 5, as shown in FIG. 14(a), the nozzle surface 4a is divided into a total of four divided regions E, two of which are arranged in each of the scanning direction and the transport direction. In Modification 6, as shown in FIG. 14(b), the nozzle surface 4a is divided into a total of 16 divided regions E, four of which are arranged in each of the scanning direction and the transport direction. In Modification 7, as shown in FIG. 14(c), the nozzle surface 4a is divided into four divided regions E, which are arranged in the transport direction. However, the manner in which the nozzle surface 4a is divided into the multiple divided regions E may differ from that shown in FIGS. 14(a) to 14(c). Furthermore, in the examples of FIGS. 14(a) to 14(c), the number of nozzles 10 located within each divided region E is the same between the divided regions E, but the number of nozzles 10 located within each divided region E may differ between the divided regions E.

[0075] The second order in Modifications 5 to 7 is an order in which, among the multiple divided regions E, the test signals are acquired for each of the nozzles 10 located in the divided region E in order from the divided region E with the smallest total number of times. As a result, the second order in Modifications 5 to 7 is an order in which, among the multiple divided regions E, the test signals are acquired first for each of the nozzles 10 located in the divided region E with the smallest total number of times.

[0076] A nozzle 10 located in the same divided region E as the nozzle 10 in which a DC leak has occurred is more likely to experience a DC leak in the next inspection process than a nozzle 10 located in a different divided region E. In variations 5 to 7, in the second inspection process, the inspection signals for each of the multiple nozzles are acquired in an order such that the inspection signal for the nozzle located in the divided region E with the fewest total number of leaks is acquired first. This increases the likelihood that inspection signals will be acquired for a larger number of nozzles before a leak occurs in the second inspection process.

[0077] In Modifications 5 to 7, the second order is an order in which the test signals are acquired for each of the nozzles 10 located in the divided area E in order from the divided area E with the smallest total number of times among the multiple divided areas E, but this is not limited to this. The second order is an order in which the test signals are acquired first for each of the nozzles 10 located in the divided area E with the smallest total number of times among the multiple divided areas E, and the order of the nozzles 10 from which the test signals are acquired thereafter may be an order different from that in Modifications 5 to 7.

[0078] In the eighth modification, the second order is an order in which test signals are acquired from nozzles 10 that are farther away from the nozzle 10 in which a DC leak occurred during the previous first test process. For example, as shown in Fig. 15, if a DC leak occurred in the nozzle 10 with nozzle number "2" during the previous first test process, the second order is to acquire test signals from the nozzles 10 with nozzle numbers "N," "N-1," ..., "4," and "3" in that order, followed by the test signal from the nozzle 10 with nozzle number "1," and finally the test signal from the nozzle 10 with nozzle number "2."

[0079] Here, any two nozzles 10 of the multiple nozzles 10 of the inkjet head 4 are designated as the first nozzle and the second nozzle, and any nozzle 10 that is farther from the first nozzle than the second nozzle is designated as the third nozzle. In this case, the second order in Modification 8 is an order in which, if the nozzle 10 in which a DC leak occurred in the previous first inspection process is the first nozzle, an inspection signal for the third nozzle is acquired before an inspection signal for the second nozzle is acquired.

[0080] If a leak occurs in a certain nozzle 10 during a test process, the closer the nozzle is to the certain nozzle 10, the more likely it is that a leak will occur in the next test process. Therefore, in Modification 8, if a DC leak occurs in a first nozzle during a first test process, in the next second test process, test signals are acquired for each of the multiple nozzles 10 in a second order, such that a test signal for a third nozzle that is farther from the first nozzle than the second nozzle is acquired before a test signal for the second nozzle is acquired. This increases the likelihood that a large number of nozzles 10 will have test signals acquired before a leak occurs in the second test process.

[0081] 16, the printer 100 according to the ninth modification is configured by replacing the maintenance unit 8 of the printer 1 according to the above-described embodiment with a maintenance unit 101. The maintenance unit 101 includes a cap 111, a switching unit 112, a suction pump 113, and a waste liquid tank 114.

[0082] The cap 111 is a combination of a first cap 111a and a second cap 111b. The first cap 111a and the second cap 111b are aligned in the scanning direction. When the carriage 2 is positioned at the maintenance position, the multiple nozzles 10 that eject black ink and that make up the rightmost nozzle row 9 face the first cap 111a, and the multiple nozzles 10 that eject color inks and that make up the three leftmost nozzle rows 9 face the second cap 111b. Here, color ink refers to yellow, cyan, and magenta ink.

[0083] In this state, when the cap 111 is raised by the cap lifting mechanism 38, the nozzles 10 constituting the rightmost nozzle row 9 are covered by the first cap 111a, and the nozzles 10 constituting the three leftmost nozzle rows 9 are covered by the second cap, resulting in a capped state. Furthermore, when the cap 111 is lowered by the cap lifting mechanism 38, the nozzles 10 are in an uncapped state where they are not covered by the caps 21. Furthermore, the first cap 111a and the second cap 111b are provided with outlets 115a and 115b, respectively.

[0084] Each of the discharge ports 115a and 115b is connected to a suction pump 113 via a switching unit 112. The switching unit 112 selectively connects either of the discharge ports 115a and 115b to the suction pump 113. The suction pump 113 is also connected to a waste liquid tank 114. The suction pump 113 is similar to the suction pump 22 in the above-described embodiment, and the waste liquid tank 114 is similar to the waste liquid tank 23 in the above-described embodiment.

[0085] In the ninth modification, when the suction pump 113 is driven in the capped state with the outlet 115a connected to the suction pump 113 by the switching unit 112, a black purge can be performed to discharge black ink from the inkjet head 4 through the nozzles 10 constituting the rightmost nozzle row 9. When the suction pump 113 is driven in the capped state with the outlet 115b connected to the suction pump 113 by the switching unit 112, a color purge can be performed to discharge color ink from the inkjet head 4 through the nozzles 10 constituting the three leftmost nozzle rows 9.

[0086] Although not shown, in Modification 9, electrodes 26 are arranged on each of first cap 111a and second cap 111b. The connection relationship between each electrode 26 and other components of inspection circuit 27 is similar to the connection relationship between electrodes 26 and other components of inspection circuit 27 in the above-described embodiment.

[0087] In the ninth modification, when the control unit 30 receives an inspection instruction signal, it also performs the process in accordance with the flowchart of Fig. 8. However, in the ninth modification, the second sequence is different from that of the above-described embodiment.

[0088] In more detail, in variant example 9, as shown in Figures 17(a) and (b), if a DC leak occurs during the inspection process, information indicating which nozzle 10 the DC leak occurred in is stored in memory 34.

[0089] As shown in Figure 17(a), if a DC leak occurs in any of the nozzles 10 constituting the rightmost nozzle row 9, i.e., the nozzle 10 that ejects black ink, during the previous first test process, the second order is an order in which test signals are obtained for each of the multiple nozzles 10 that eject colored inks constituting the three leftmost nozzle rows 9, and then test signals are obtained for each of the multiple nozzles 10 that eject black ink constituting the rightmost nozzle row 9.

[0090] As shown in Figure 17(b), if a DC leak occurs in any of the nozzles 10 constituting the three left-hand nozzle rows 9, i.e., in a nozzle 10 that ejects colored ink, during the previous first test process, the second order is an order in which test signals are obtained for each of the multiple nozzles 10 that eject black ink constituting the rightmost nozzle row 9, and then test signals are obtained for each of the multiple nozzles 10 that eject colored ink constituting the three left-hand nozzle rows 9.

[0091] 17(a) and 17(b), in Modification 9, when acquiring test signals for each of the plurality of nozzles 10 that eject black ink, and when acquiring test signals for each of the nozzles 10 that eject color ink, the second order is set to an order in which test signals are acquired in order from the nozzle 10 with the smallest nozzle number. However, the order in which test signals are acquired for each of the plurality of nozzles 10 that eject black ink in the second order may be different. The order in which test signals are acquired for each of the plurality of nozzles 10 that eject color ink in the second order may be different.

[0092] If a leak occurs in a nozzle 10 that ejects black ink, it may be caused by ink adhering to the first cap 111a. Therefore, in Modification 9, in a first test process in which a test signal is acquired for each of the multiple nozzles 10 covered by the first cap 111a and then a test signal is acquired for each of the multiple nozzles 10 covered by the second cap 111b, if a leak occurs in a nozzle 10 covered by the first cap 111a, in the subsequent second test process, the test signals for each of the multiple nozzles are acquired in a second order such that a test signal is acquired for each of the multiple nozzles 10 covered by the second cap 111b and then a test signal is acquired for each of the first nozzles covered by the first cap 111a. This increases the likelihood that a large number of nozzles will acquire test signals before a leak occurs in the second test process.

[0093] In Modification 10, when an inspection instruction signal is received, the control unit 30 performs processing according to the flowchart of Fig. 18. In more detail, the control unit 30 first determines whether or not the first inspection process was performed during the previous inspection process (S201). If the first inspection process was performed during the previous inspection process (S201: YES), the control unit 30 starts the second inspection process (S202). If the second inspection process was performed during the previous inspection process (S201: NO), the control unit 30 starts the first inspection process (S203).

[0094] If the test process is stopped due to a leak or other reason during the test process, the test signal for the nozzle 10 from which the test signal was scheduled to be acquired will not be acquired. In Modification 10, when the test process is performed after the first test process, the second test process is performed in the next test process regardless of whether a leak occurred during the first test process. This makes it possible to reduce the bias toward nozzles from which test signals are not acquired, and minimize the number of nozzles from which test signals are not acquired. Furthermore, the process can be simplified compared to when whether the first test process or the second test process is performed in the test process following the first test process is changed depending on whether a leak occurred during the first test process.

[0095] In Modification 11, when the control unit 30 receives a purge instruction signal instructing that purging be performed, the control unit 30 performs processing in accordance with the flowchart of FIG. 19(a). Describing the flowchart of FIG. 19(a) in more detail, when the control unit 30 receives the purge instruction signal, the control unit 30 first executes a purge process (S301). In the purge process, the control unit 30 controls the carriage motor 36, the cap lifting mechanism 38, the suction pump 22, etc. to perform the above-mentioned suction purge. Next, the control unit 30 executes an empty suction process (S302). In the empty suction process, the control unit 30 controls the carriage motor 36, the cap lifting mechanism 38, the suction pump 22, etc. to perform the above-mentioned empty suction.

[0096] In Modification 11, when an inspection instruction signal is received, the control unit 30 performs processing according to the flowchart of Fig. 19(b). More specifically, the control unit 30 first determines whether or not a predetermined time has passed since the last suction purge was performed (S401). If the predetermined time has passed since the last suction purge was performed (S401: YES), the control unit 30 executes a first inspection process (S402). If the predetermined time has passed since the last suction purge was performed (S401: NO), the control unit 30 executes a second inspection process (S403).

[0097] 19(c), the control unit 30 acquires a test signal for each of the plurality of nozzles 10 of the inkjet head 4 in a first order such that the control unit 30 first acquires a test signal for each of the plurality of nozzles 10a located within an area F1 on the outer edge of the nozzle surface 4a, and then acquires a test signal for each of the plurality of nozzles 10b located within an area F2 of the nozzle surface 4a that is farther from the lip portion 29 than the area F1 in the capped state. Note that in Modification 11, the nozzles 10a located within the area F1 correspond to the "first nozzle" of the present invention, and the nozzles 10b located within the area F2 correspond to the "second nozzle" of the present invention.

[0098] In the second inspection process, the control unit 30 acquires an inspection signal for each of the plurality of nozzles 10 of the inkjet head 4 in a second order, such as acquiring an inspection signal for each of the plurality of nozzles 10b located in region F2, and then acquiring an inspection signal for each of the plurality of nozzles 10a located in region F1.

[0099] In the first and second inspection processes, the order in which the inspection signals are acquired for each of the multiple nozzles 10a located in region F1 and the order in which the inspection signals are acquired for each of the multiple nozzles 10b located in region F2 can be arbitrary. For example, the inspection signals may be acquired for each of the multiple nozzles 10a located in region F1 in the order of their nozzle numbers. Also, for example, the inspection signals may be acquired for each of the multiple nozzles 10b located in region F2 in the order of their nozzle numbers.

[0100] After purging, ink may remain on the lip portion 29, and ink adhering to the lip portion 29 is likely to cause leakage in nozzles 10 close to the lip portion 29. Therefore, in Modification 11, when the inspection process is performed after a predetermined time has passed since the last purging, a first inspection process is performed to acquire inspection signals for each of the plurality of nozzles 10 in a first order, such as acquiring inspection signals for the plurality of nozzles 10a, and then acquiring inspection signals for the plurality of nozzles 10b that are farther from the lip portion 29 than the plurality of nozzles 10a. On the other hand, when the inspection process is performed before a predetermined time has passed since the last purging, a second inspection process is performed to acquire inspection signals for each of the plurality of nozzles in a second order, such as acquiring inspection signals for the plurality of nozzles 10b, and then acquiring inspection signals for the plurality of nozzles 10a that are closer to the lip portion 29 than the plurality of nozzles 10b. This maximizes the number of nozzles 10 from which inspection signals are acquired before leakage occurs, and minimizes the number of nozzles 10 from which inspection signals are not acquired during the inspection process.

[0101] In Modification 12, similar to Modification 11, when a purge instruction signal instructing to perform purging is received, the control unit 30 performs processing in accordance with the flowchart of Fig. 19(a). Also, in Modification 12, similar to Modification 11, when an inspection instruction signal is received, the control unit 30 performs processing in accordance with the flowchart of Fig. 19(b).

[0102] However, in Modification 12, the first order in the first testing process and the second order in the second testing process differ from those in Modification 11. More specifically, in Modification 12, in the first testing process, the control unit 30 acquires testing signals for each of the plurality of nozzles 10 of the inkjet head 4 in a first order such that, after acquiring testing signals for each of the plurality of nozzles 10c located in a region G1 on the downstream side of the nozzle surface 4a in the transport direction as shown in Fig. 20 , the control unit 30 acquires testing signals for each of the plurality of nozzles 10d located in a region G2 on the nozzle surface 4a that is farther from the discharge outlet 28 than the region G1 in the capped state. In Modification 12, the nozzles 10c located in the region G1 correspond to the "first nozzle" of the present invention, and the nozzles 10d located in the region G2 correspond to the "second nozzle" of the present invention.

[0103] In the second inspection process, the control unit 30 acquires an inspection signal for each of the multiple nozzles 10 of the inkjet head 4 in a second order, such as acquiring an inspection signal for each of the multiple nozzles 10d located in region G2, and then acquiring an inspection signal for each of the multiple nozzles 10c located in region G1.

[0104] In the first and second inspection processes, the order in which the inspection signals are acquired for each of the plurality of nozzles 10c located in region G1 and the order in which the inspection signals are acquired for each of the plurality of nozzles 10d located in region G2 may be arbitrary. For example, the inspection signals may be acquired for each of the plurality of nozzles 10c located in region G1 in the order of their nozzle numbers. Also, for example, the inspection signals may be acquired for each of the plurality of nozzles 10d located in region G2 in the order of their nozzle numbers.

[0105] When idle suction is performed after purging, ink may adhere to the area near the outlet 28 of the cap 21, and the nozzles 10 close to the outlet 28 are prone to leaks due to the ink adhered to the area near the outlet 28 of the cap 21. Therefore, in Modification 12, when the inspection process is performed after a predetermined time has passed since the last purging, a first inspection process is performed to acquire inspection signals for each of the plurality of nozzles 10 in a first order, such as acquiring inspection signals for the plurality of nozzles 10c, and then acquiring inspection signals for the plurality of nozzles 10d that are farther from the outlet 28 than the plurality of nozzles 10c. On the other hand, when the inspection process is performed before a predetermined time has passed since the last purging, a second inspection process is performed to acquire inspection signals for each of the plurality of nozzles 10 in a second order, such as acquiring inspection signals for the plurality of nozzles 10d, and then acquiring inspection signals for the plurality of nozzles 10c that are closer to the outlet 28 than the plurality of nozzles 10d. This allows the number of nozzles 10 from which inspection signals are acquired before a leak occurs to be as large as possible, and the number of nozzles 10 from which inspection signals are not acquired during the inspection process to be as small as possible.

[0106] In Modifications 11 and 12, the inspection signal for which of the multiple first nozzles or the multiple second nozzles 10 is acquired is determined depending on whether the time elapsed since the last purge is equal to or greater than a predetermined time. In Modification 11, the multiple nozzles 10a are defined as the first nozzles, and the multiple nozzles 10b, which are farther from the lip portion 29 than the multiple nozzles 10a, are defined as the second nozzles. In Modification 12, the multiple nozzles 10c are defined as the first nozzles, and the multiple nozzles 10d, which are farther from the outlet 28 than the multiple nozzles 10c, are defined as the second nozzles. However, the first nozzles and the second nozzles may be different.

[0107] For example, if there is a difference in the amount of ink adhering to the nozzle surface 4a between regions thereof after purging, the nozzle 10 located in the region of the nozzle surface 4a where a large amount of ink has adhered thereto after purging may be designated as the first nozzle, and the nozzle 10 located in the region of the nozzle surface 4a where a small amount of ink has adhered thereto after purging may be designated as the second nozzle.

[0108] In the thirteenth modification, the control unit 30 can execute X types of inspection processes, 1st to Xth inspection processes, where X is an integer greater than or equal to 2 and less than or equal to N. In the Zth inspection process, where Z is a variable greater than or equal to 1 and less than or equal to X, inspection signals are acquired for each of the multiple nozzles 10 of the inkjet head 4 in the Zth order.

[0109] The first order when Z is 1 is the same as the first order in the above embodiment, in which the test signals are acquired for each of the multiple nozzles 10 of the inkjet head 4 in the order of the nozzle numbers.

[0110] When Z is 2 or more, the Zth order is an order in which, as shown in Figure 21(a), Y is an integer greater than or equal to 1 and satisfies the relationship [(X-1) x Y+1] ≦ N, test signals are acquired for each of the nozzles 10 with nozzle numbers [(Z-1) x Y+1] to N in the order of the nozzle numbers, and then test signals are acquired for each of the nozzles 10 with nozzle numbers 1 to [(Z-1) x Y] in the order of the nozzle numbers.

[0111] However, when X=N, Y, which is 1 or greater and satisfies the relationship [(X-1)×Y+1]≦N, is 1 only, and [(X-1)×Y+1] becomes N. In this case, the Nth order, which is the Zth order when Z=N, is an order in which a test signal is acquired for the nozzle 10 with nozzle number "N" among the nozzles 10 with nozzle numbers [(Z-1)×Y+1] to N, and then a test signal is acquired for each of the nozzles with nozzle numbers "1" to "N-1" among the nozzles 10 with nozzle numbers 1 to [(Z-1)×Y] in the order of the nozzle numbers.

[0112] In addition, in Modification 13, when the control unit 30 receives an inspection instruction signal, it performs processing according to the flowchart in Fig. 21(b). Here, in Modification 13, for example, when the printer 1 is started for the first time, the variable Z is set to 1.

[0113] 21(b) in detail, the control unit 30 first determines whether or not a DC leak occurred during the previous test process (S501). If a DC leak did not occur during the previous test process (S501: NO), the control unit 30 executes the Zth test process without changing the variable Z (S505).

[0114] If a DC leak occurred during the previous inspection process (S501: YES), the control unit 30 then determines whether or not the variable Z is equal to X (S502). If the variable Z is not equal to X (S502: NO), the control unit 30 increments the value of the variable Z by 1 (S503) and executes the Zth inspection process (S505). If the variable Z is equal to X (S502: YES), the control unit 30 sets the value of the variable Z to 1 (S504) and executes the Zth inspection process (S505). That is, the control unit 30 executes the first inspection process.

[0115] In the modification 14, X types of inspection processes, 1st to Xth inspection processes, can be executed similarly to the modification 13. In the modification 13, the control unit 30 executes the process according to the flowchart of Fig. 22(b) when it receives an inspection instruction signal. Here, in the modification 14, for example, the variable Z is set to 1 when the printer 1 is started for the first time.

[0116] 21 will be described in detail. The control unit 30 determines whether the variable Z is equal to X (S601). If the variable Z is not equal to X (S601: NO), the control unit 30 increments the value of the variable Z by 1 (S602) and executes the Zth inspection process (S604). If the variable Z is equal to X (S601: YES), the control unit 30 sets the value of the variable Z to 1 (S603) and executes the Zth inspection process (S604). That is, the control unit 30 executes the first inspection process.

[0117] <Effects> In variations 13 and 14, the order of nozzles from which test signals are acquired is shifted by Y between the first through Xth test processes. As a result, by executing one of the first through Xth test processes depending on the conditions in the test process, it is possible to change the order and acquire test signals for each of the multiple nozzles 10. As a result, when the test process is repeated, test signals can be acquired evenly for the multiple nozzles 10, and it is possible to minimize the number of nozzles 10 from which test signals are not acquired.

[0118] In the modified example 15, it is also possible to execute X types of inspection processes, 1st to Xth inspection processes, similar to the modified example 13. Furthermore, in the modified example 15, when the control unit 30 receives an inspection instruction signal, it performs processing according to the flowchart of Fig. 21(b) similar to the modified example 13, or the flowchart of Fig. 22 similar to the modified example 14.

[0119] In addition, in Modification 15, while power is being supplied to the printer 1, the control unit 30 performs processing in accordance with the flowchart in Fig. 23(a). More specifically, the control unit 30 waits until the predetermined time has arrived (S701: NO). Then, when the predetermined time arrives (S701: YES), the control unit 30 resets the value of the variable Z to 1 (S702), and the process returns to S701.

[0120] As a result, in variant 15, variable Z is reset to 1 at each predetermined time, and the first inspection process is executed when the inspection process is executed for the first time in the cycle from a predetermined time to the next predetermined time, the second inspection process is executed when the inspection process is executed for the second time in the cycle, and so on, so that the Zth inspection process is executed when the inspection process is executed for the Zth time in the cycle.

[0121] In Modification 15, the period from a predetermined time to the next predetermined time is considered to be one cycle, and by changing the order of nozzles from which inspection signals are acquired in the first inspection process and the second inspection process in this cycle, it is possible to evenly acquire inspection signals for the multiple nozzles 10. Furthermore, the order of nozzles 10 from which inspection signals are acquired can be reset for each cycle.

[0122] In the modified example 16, X types of inspection processes, 1st to Xth inspection processes, can be executed similarly to the modified example 13. Furthermore, in the modified example 16, when the control unit 30 receives an inspection instruction signal, it executes processing according to the flowchart of Fig. 21(b) similar to the modified example 13, or the flowchart of Fig. 22 similar to the modified example 14.

[0123] In addition, in Modification 16, the control unit 30 performs processing according to the flowchart in Fig. 23(b) while power is being supplied to the printer 1. In addition, in Modification 16, for example, when the printer 1 is started for the first time, a variable H, which will be described later, is set to 0.

[0124] 23(b) in detail, the control unit 30 waits while recording on one sheet of recording paper S is not completed (S801: NO). Then, when recording on one sheet of recording paper S is completed (S801: YES), the control unit 30 increments the value of the variable H by 1 (S802) and determines whether the value of the variable H is equal to or greater than a predetermined value H1 (S803). If the value of the variable H is less than the predetermined value H1 (S803: NO), the process returns to S801. If the value of the variable H is equal to or greater than the predetermined value H1 (S803: YES), the control unit 30 resets the variable Z to 1 (S804) and resets the variable H to 0 (S805), and the process returns to S801.

[0125] As a result, in variant 16, variable Z is reset to 1 every time recording is made on H1 sheets of recording paper S, and the period during which recording is made on H1 sheets of recording paper S is considered to be one cycle, and when the inspection process is performed for the first time in this cycle, the first inspection process is performed, when the inspection process is performed for the second time in the cycle, the second inspection process is performed, and so on, when the inspection process is performed for the Zth time in the cycle, the Zth inspection process is performed.

[0126] In Modification 16, by changing the order of nozzles that acquire test signals between the first test process and the second test process in a cycle in which recording is performed on H sheets of recording paper S, it is possible to acquire test signals evenly for the multiple nozzles 10. Also, the order of nozzles 10 that acquire test signals can be reset for each cycle.

[0127] In addition, in a configuration in which the first inspection process is performed in one cycle, and the second inspection process is performed when the inspection process is performed for the second time in the cycle, in variant example 16, the period from a predetermined time to the next predetermined time is considered to be one cycle, and in variant example 17, the period in which recording is made on H1 sheets of recording paper S is considered to be one cycle, but a period other than these may also be considered to be one cycle.

[0128] In Modification 17, as shown in Fig. 24, information on the number of times DC leaks have occurred is stored for each of the multiple nozzles 10 of the inkjet head 4. In Modification 7, in the first inspection process and the second inspection process, inspection signals are acquired for each of the multiple nozzles 10 of the inkjet head 4 in the first and second orders, respectively, similar to, for example, any of the examples described above. However, in Modification 17, inspection signals are acquired for each of the nozzles 10 excluding nozzles 10 for which DC leaks have occurred the second number of times or more. Fig. 24 shows the case where the second number of times is 5, and inspection signals are acquired for each of the nozzles 10 excluding nozzles 10 with nozzle numbers marked with an x, i.e., nozzles 10 with nozzle numbers marked with a circle.

[0129] Nozzles 10 that have experienced a large number of leaks are more likely to experience leaks in subsequent inspection processes. Therefore, in Modification 17, inspection signals are acquired sequentially for each nozzle 10, excluding nozzles 10 that have experienced leaks the second or greater number of times. This makes it less likely that leaks will occur in the inspection process.

[0130] Furthermore, in the above-described embodiments and variants 1 to 9, 15, etc., when a DC leak occurs during the execution of a first test process, a second test process is executed in the next test process, whereas when an AC leak occurs during the execution of a first test process, the same first test process as the previous test process is executed in the next test process, but this is not limited to this.

[0131] For example, if either a DC leak or an AC leak occurs during the execution of the first test process, the second test process may be executed in the next test process.

[0132] Alternatively, for example, when an AC leak occurs during the execution of the first test process, a second test process is executed in the next test process, whereas when a DC leak occurs during the execution of the first test process, the same first test process as the previous test process is executed in the next test process, but this is not limited to this.

[0133] In the above example, the printer 1 performs suction purging as a purge, but this is not limiting. For example, a pressure pump that pressurizes the ink in the inkjet head 4 may be provided in a flow path between the ink cartridge and the inkjet head 4. Then, a pressure purge that discharges the ink from the inkjet head 4 may be performed by driving the pressure pump with the multiple nozzles 10 covered with the cap 21. In this case, the combination of the cap 21 and the pressure pump corresponds to the "purge unit" of the present invention.

[0134] In addition, both suction purging by driving the suction pump 22 and pressure purging by driving the pressure pump may be performed. In this case, the maintenance unit 8 and the pressure pump together correspond to the "purging section" of the present invention.

[0135] 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 in the scanning direction.

[0136] Although the above description has been given of an example in which the present invention is applied to a printer that ejects ink from nozzles to perform recording on recording paper S, the present invention is not limited to this. The present invention can also be applied to recording devices that record images on recording media other than recording paper, such as T-shirts, outdoor advertising sheets, cases for mobile devices such as smartphones, cardboard, and resin materials. The present invention can also be applied to liquid ejection devices that eject liquids other than ink droplets, such as liquid resin or metal liquids. [Explanation of symbols]

[0137] 1: Printer 4: Inkjet head 8: Maintenance unit 10: Nozzle 21: Cap 26: Electrode 27: Inspection circuit 30: Control unit 51: Voltage supply circuit 52: High-pass filter 53: Amplification circuit 54: Low-pass filter 55: Latch circuit 100: Printer 101: Maintenance unit 111a: 1st Cap 111b: 2nd Cap

Claims

1. A head having a plurality of nozzles; an inspection signal output unit having an electrode, the inspection signal output unit outputting an inspection signal corresponding to an electrical change in the electrode when the head is driven to eject liquid from the nozzle toward the electrode; A control unit, The control unit is driving the head in sequence for each of the plurality of nozzles to eject liquid from the nozzle toward the electrode, acquiring the inspection signal output from the inspection signal output unit, and executing an inspection process to inspect whether or not there is an abnormality in the ejection of liquid from the nozzle based on the acquired inspection signal; In the inspection process, a first inspection process for acquiring the inspection signals in a first order for each of the plurality of nozzles; a second inspection process for acquiring the inspection signals for each of the plurality of nozzles in a second order different from the first order.

2. a leak signal output unit that outputs a leak signal according to whether or not a leak occurs between the head and the electrode, the leak signal output unit being equal to or greater than a predetermined value; The control unit is When the leak signal output unit outputs the leak signal indicating the occurrence of the leak during the execution of the inspection process, the inspection process is stopped; A liquid ejection device as described in claim 1, characterized in that when the leak signal indicating that the leak has occurred is output from the leak signal output section during execution of the first inspection process, the second inspection process is executed in the inspection process following the first inspection process.

3. a leak signal output unit that outputs a leak signal according to whether or not a leak occurs between the head and the electrode, the leak signal output unit being equal to or greater than a predetermined value; The control unit is When the leak signal output unit outputs the leak signal indicating the occurrence of the leak during the execution of the inspection process, the inspection process is stopped; A liquid ejection device as described in claim 1, characterized in that the second inspection process is executed in the inspection process following the first inspection process, regardless of whether the leak signal indicating that the leak has occurred is output from the leak signal output section during execution of the first inspection process.

4. N is an integer equal to or greater than 2, the plurality of nozzles includes first to Nth nozzles, The control unit is Let X be an integer between 2 and N, In the inspection process, first to Xth inspection processes can be executed, In the first inspection process, the inspection signal is acquired for each of the plurality of nozzles in the first order such that the inspection signal is acquired in order from a first nozzle to an Nth nozzle; Y is an integer equal to or greater than 1 and satisfies the relationship [(X-1) x Y + 1] ≦ N, and Z is an integer equal to or greater than 2 and equal to or less than X, A liquid ejection device as described in claim 1, characterized in that in the Z inspection process, the inspection signals are acquired for each of the multiple nozzles in an order such that the inspection signals are acquired in order from the [(Z-1) x Y+1]th nozzle to the Nth nozzle, and then the inspection signals are acquired in order from the first nozzle to the [(Z-1) x Y]th nozzle.

5. The control unit is When the inspection process is executed for the first time in a predetermined cycle, the first inspection process is executed; The liquid ejection apparatus according to claim 1 , wherein the second inspection process is executed when the inspection process is executed for a second time in the predetermined cycle.

6. a purge unit that performs purging to discharge liquid from the plurality of nozzles; a leak signal output unit that outputs a leak signal according to whether or not a leak occurs between the head and the electrode, in which a current of a predetermined value or more flows; The control unit is When the leak signal output unit outputs the leak signal indicating the occurrence of the leak during the execution of the inspection process, the inspection process is stopped; When the inspection process is to be executed in a state where a predetermined time or more has elapsed since the last purge was performed by the purge unit, the first inspection process is executed; The liquid ejection device according to claim 1 , wherein the second inspection process is executed when the inspection process is executed before the predetermined time has elapsed since the last purge was performed by the purge section.

7. a cap for covering the plurality of nozzles; the cap has a lip portion that is disposed to surround a portion of the cap that faces the plurality of nozzles when the cap covers the plurality of nozzles and that protrudes toward the head; The electrode is contained within the cap; The purge unit performs the purge by discharging liquid from the plurality of nozzles into the cap, the plurality of nozzles includes a first nozzle and a second nozzle that is farther from the lip portion than the first nozzle when the plurality of nozzles are covered by the cap, The control unit is acquiring the test signal for each of the plurality of nozzles in the first order such that, in the first test process, the test signal for the first nozzle is acquired, and then the test signal for the second nozzle is acquired; A liquid ejection device as described in claim 6, characterized in that in the second inspection process, the inspection signal for each of the multiple nozzles is acquired in the second order such that after the inspection signal for the second nozzle is acquired, the inspection signal for the first nozzle is acquired.

8. a cap for covering the plurality of nozzles; The electrode is contained within the cap; the cap has a drain port for draining liquid within the cap, The purge unit has a suction pump connected to the exhaust port, the plurality of nozzles includes a first nozzle and a second nozzle that is farther from the outlet than the first nozzle when the plurality of nozzles are covered by the cap, The control unit is driving the suction pump in a state where the plurality of nozzles are covered with the cap, thereby performing the purging in which liquid is discharged from the plurality of nozzles to the cap; Immediately after the purging, the suction pump is driven in a state in which the plurality of nozzles are not covered with the cap, thereby performing idle suction to discharge the liquid in the cap from the discharge port; acquiring the test signal for each of the plurality of nozzles in the first order such that, in the first test process, the test signal for the first nozzle is acquired, and then the test signal for the second nozzle is acquired; A liquid ejection device as described in claim 6, characterized in that in the second inspection process, the inspection signal for each of the multiple nozzles is acquired in the second order such that after the inspection signal for the second nozzle is acquired, the inspection signal for the first nozzle is acquired.

9. The leak signal output unit is a DC leak signal output unit that outputs a DC leak signal according to whether or not a DC leak occurs, in which a current equal to or greater than the predetermined value continuously flows between the head and the electrode; an AC leak signal output unit that outputs an AC leak signal according to whether or not an AC leak occurs, in which a current of a predetermined value or more temporarily flows between the head and the electrode; The control unit is A liquid ejection device as described in claim 2, characterized in that when the DC leak signal indicating that the DC leak has occurred is output from the DC leak signal output unit during execution of the first inspection process, the second inspection process is executed in the inspection process following the first inspection process.

10. The control unit is The liquid ejection device according to claim 9, characterized in that even if the AC leak signal indicating that the AC leak has occurred is output from the AC leak signal output unit during execution of the first inspection process, if the DC leak signal indicating that the DC leak has occurred is not output from the DC leak signal output unit, the first inspection process is executed in the inspection process next to the first inspection process.

11. A storage unit, The control unit is storing information on the number of occurrences of the leak for each of the plurality of nozzles in the storage unit; A liquid ejection device as described in claim 2, characterized in that in the second inspection process, the inspection signal for each of the multiple nozzles is acquired in the second order such that the inspection signal for a nozzle other than the nozzle from which the inspection signal was first acquired in the first inspection process and for which the number of times the leak has occurred is a first number or less is acquired first.

12. A storage unit, The control unit is storing information on the number of occurrences of the leak for each of the plurality of nozzles in the storage unit; A liquid ejection device as described in claim 2, characterized in that in the second inspection process, the inspection signals for each of the multiple nozzles are obtained in the second order such that the inspection signals are obtained in order from the nozzles with the least number of occurrences of the leak.

13. A storage unit, The control unit is when the leak signal output unit outputs the leak signal indicating that the leak has occurred in the inspection process, information indicating which nozzle the leak has occurred in is stored in the storage unit; A liquid ejection device as described in claim 2, characterized in that in the second inspection process, the inspection signal for each of the multiple nozzles is acquired in the second order such that the inspection signal for any of the nozzles other than the nozzle in which the leak occurred in the first inspection process is acquired first.

14. A storage unit, The control unit is when the leak signal output unit outputs the leak signal indicating that the leak has occurred in the inspection process, information indicating which nozzle the leak has occurred in is stored in the storage unit; A liquid ejection device as described in claim 2, characterized in that in the second inspection process, the inspection signal for each of the multiple nozzles is acquired in the second order such that the inspection signal for the nozzle for which the inspection signal was scheduled to be acquired after a predetermined number of nozzles (2 or more) in the first order from the nozzle in which the leak occurred in the first inspection process is acquired first.

15. A storage unit, The plurality of nozzles are a plurality of first nozzles that eject a first liquid; a plurality of second nozzles for ejecting a second liquid different in type from the first liquid; the control unit stores in the storage unit information on a first total number of times that leakage has occurred in each of the plurality of first nozzles, and information on a second total number of times that leakage has occurred in each of the plurality of second nozzles, In the second inspection process, if the first total number is less than the second total number, acquiring the test signal for each of the plurality of nozzles in the second order such that after acquiring the test signal for each of the plurality of first nozzles, the test signal for each of the plurality of second nozzles is acquired; A liquid ejection device as described in claim 2, characterized in that when the second total number is less than the first total number, the inspection signal for each of the plurality of nozzles is acquired in the second order, such that the inspection signal for each of the plurality of second nozzles is acquired first, and then the inspection signal for each of the plurality of first nozzles is acquired.

16. A storage unit, the head has a nozzle surface on which the plurality of nozzles are arranged, the control unit causes the storage unit to store information on a total number of leak occurrences obtained by adding up the number of times the leak occurred in the nozzles located within each of a plurality of divided regions obtained by dividing the nozzle surface; In the second inspection process, A liquid ejection device as described in claim 2, characterized in that the test signals for each of the plurality of nozzles are acquired in the second order such that the test signals for the nozzles located in the divided area among the plurality of divided areas that has the smallest total number of leaks are acquired first.

17. A storage unit, The control unit is storing information on the number of occurrences of the leak for each of the plurality of nozzles in the storage unit; In the inspection process, When the number of occurrences of the leak is equal to or greater than the second number of times, 3. The liquid ejection device according to claim 2, wherein the inspection signal is acquired in sequence for each of the nozzles, excluding the nozzle in which the leak has occurred the second number of times or more, out of the plurality of nozzles.

18. A storage unit, the plurality of nozzles includes a first nozzle, a second nozzle, and a third nozzle that is farther away from the first nozzle than the second nozzle; The control unit is When the leak signal output unit outputs the leak signal indicating that the leak has occurred in the inspection process, information indicating which nozzle the leak has occurred in is stored in the storage unit; In the first inspection process, when information indicating that the leak has occurred in the first nozzle is stored in the storage unit, A liquid ejection device as described in claim 2, characterized in that in the second inspection process performed in the inspection process following the first inspection process, the inspection signal for each of the multiple nozzles is acquired in the second order such that the inspection signal for the third nozzle is acquired before the inspection signal for the second nozzle.

19. the plurality of nozzles includes a plurality of first nozzles and a plurality of second nozzles; a first cap covering the first nozzles; a second cap covering the second nozzles, the electrodes are housed within the first cap and the second cap, The control unit is acquiring the test signal for each of the plurality of nozzles in the first order such that, in the first test process, after acquiring the test signal for each of the plurality of first nozzles, the test signal for each of the plurality of second nozzles is acquired; The liquid ejection device described in claim 2, characterized in that when the leak signal indicating that the leak has occurred in the first nozzle is output from the leak signal output unit during the first inspection process, in the second inspection process performed in the inspection process following the first inspection process, the inspection signal for each of the plurality of nozzles is acquired in the second order such that the inspection signal for each of the plurality of second nozzles is acquired first, and then the inspection signal for each of the plurality of first nozzles is acquired.

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