Anomaly detection method, liquid flow system, recording device

Abstract

Provided is an abnormality detection method, a liquid flow system, and a recording device that can reduce the influence of individual differences in a liquid pump to detect abnormalities. An abnormality detection method for a recording device that includes a liquid ejection head that ejects liquid, a supply flow path through which the liquid flows, a supply pump provided in the supply flow path, a first drive motor that drives the supply pump, and a first measurement unit that measures current flowing in the first drive motor, the abnormality detection method including: setting a maximum value among a plurality of current values output by the first measurement unit in a startup time zone as a startup current value; determining whether the supply pump is abnormal based on whether the startup current value is included in a reference range; performing an arithmetic process on a plurality of current values output by the first measurement unit in an arithmetic time zone after the startup time zone to set a determination value; and determining whether the supply flow path is abnormal by comparing the startup current value and the determination value.

Description

Technical Field

[0001] This invention relates to anomaly detection methods, liquid flow systems, and recording devices. Background Technology

[0002] For example, as in Patent Document 1, there is a recording device that records by ejecting ink, a liquid, from a recording head, which is an example of a liquid ejector. The recording device includes a drive motor, a supply pump, a current detection circuit, a measuring unit, and a main control unit.

[0003] The drive motor drives the supply pump. The supply pump supplies the ink contained in the ink cartridge to the recording head. The current detection circuit detects the current flowing when the drive motor is running. When the current value detected by the current detection circuit reaches a certain value, the control unit considers it an abnormal pressure in the supply pump and stops the drive motor.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2007-105935

[0005] The current flowing in the drive motor varies from person to person. Therefore, as in Patent Document 1, when comparing the detected current value with a fixed threshold, there may be anomalies in the liquid flow path that cannot be detected. Summary of the Invention

[0006] An anomaly detection method for solving the above-mentioned technical problems is an anomaly detection method for a recording device. The recording device includes: a liquid nozzle for spraying liquid into a medium for recording; a liquid flow path for liquid flow; a liquid pump disposed in the liquid flow path; a drive motor for driving the liquid pump; and a measuring unit for measuring the current flowing in the drive motor and outputting a current value. The anomaly detection method includes: setting the maximum value among multiple current values ​​output by the measuring unit within a startup time period as a startup current value; determining whether the liquid pump is abnormal based on whether the startup current value is within a reference range; performing calculations on multiple current values ​​output by the measuring unit within a calculation time period after the startup time period to set a judgment value; and determining whether the liquid flow path is abnormal by comparing the startup current value with the judgment value.

[0007] A liquid flow system for solving the above-mentioned technical problems includes: a liquid flow path for supplying liquid to or discharging liquid from a liquid nozzle, wherein the liquid nozzle sprays liquid into a medium for recording; a liquid pump disposed in the liquid flow path; a drive motor for driving the liquid pump; a measuring unit for measuring the current flowing in the drive motor and outputting a current value; and a control unit that sets the maximum value among multiple current values ​​output by the measuring unit within a start-up time period as a start-up current value, determines whether the liquid pump is malfunctioning based on whether the start-up current value is within a reference range, performs calculations on multiple current values ​​output by the measuring unit within a calculation time period after the start-up time period to set a judgment value, and determines whether the liquid flow path is malfunctioning by comparing the start-up current value with the judgment value.

[0008] A recording device for solving the above-mentioned technical problems includes: a liquid ejector head for spraying liquid into a medium for recording; a liquid flow path for liquid flow; a liquid pump disposed in the liquid flow path; a drive motor for driving the liquid pump; a measuring unit for measuring the current flowing in the drive motor and outputting a current value; and a control unit that sets the maximum value among multiple current values ​​output by the measuring unit within a start-up time period as a start-up current value, determines whether the liquid pump is malfunctioning based on whether the start-up current value is within a reference range, performs calculations on multiple current values ​​output by the measuring unit within a calculation time period after the start-up time period, sets a judgment value, and determines whether the liquid flow path is malfunctioning by comparing the start-up current value with the judgment value.

[0009] An anomaly detection method for solving the above-mentioned technical problems is an anomaly detection method for a recording device. The recording device includes: a liquid ejector head for spraying liquid into a medium for recording; a liquid flow path for liquid flow; a liquid pump disposed in the liquid flow path; a drive motor for driving the liquid pump; and a measuring unit for measuring the current flowing in the drive motor and outputting a current value. The anomaly detection method includes: setting the current value output by the measuring unit at an initial time point as a starting current value; determining whether the liquid pump is abnormal based on whether the starting current value is within a reference range; and determining whether the liquid flow path is abnormal by comparing the starting current value with the current value output by the measuring unit at measurement time points after the initial time point. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of a recording device.

[0011] Figure 2 It is a diagram showing the startup time range and the computation time range.

[0012] Figure 3 This is a flowchart illustrating the first anomaly detection procedure.

[0013] Figure 4 It is a graph showing the initial time point and the measurement time point.

[0014] Figure 5 This is a flowchart illustrating the second anomaly detection procedure.

[0015] Explanation of reference numerals in the attached figures

[0016] 11…Recording device, 12…Liquid nozzle, 13…Supply system as an example of a liquid flow system, 14…Preservation system as an example of a liquid flow system, 16…Nozzle, 17…Medium, 19…Mounting part, 20…Supply flow path as an example of a liquid flow path, 21…First liquid delivery part, 22…Buffer, 23…Pressure regulating valve, 25…Liquid container, 27…First check valve, 28…Supply pump as an example of a liquid pump, 29…Second check valve, 30…First drive motor as an example of a drive motor, 31…First measuring part as an example of a measuring part, 33…cap, 34…discharge flow path as an example of liquid flow path, 35…second liquid delivery section, 36…waste liquid container, 38…suction pump as an example of liquid pump, 39…second drive motor as an example of drive motor, 40…second measuring section as an example of measuring section, 42…notification section, 43…control section, Dd…discharge direction, Ds…supply direction, IR…reference range, td…judgment time point, te…end time point, ti…initial time point, tm…measurement time point, ts…start time point, TRa…start time area, TRo…operation time area. Detailed Implementation

[0017] The following description, with reference to the accompanying drawings, describes one embodiment of the recording device, liquid flow system, and anomaly detection method. The recording device is, for example, an inkjet printer that records data by ejecting ink (a liquid) onto media such as paper, fabric, vinyl, plastic parts, and metal parts.

[0018] Recording device

[0019] like Figure 1 As shown, the recording device 11 may include a liquid ejector head 12, a supply system 13 as an example of a liquid flow system, and a preservation system 14 as an example of a liquid flow system.

[0020] The liquid ejector head 12 has one or more nozzles 16. The liquid ejector head 12 is capable of ejecting liquid from the nozzles 16. The liquid ejector head 12 ejects liquid to the medium 17 for recording.

[0021] Supply system

[0022] The supply system 13 may include an installation part 19, a supply flow path 20 as an example of a liquid flow path, a first liquid delivery part 21, a buffer 22, and a pressure regulating valve 23.

[0023] The supply system 13 supplies liquid to the liquid nozzle 12. The supply system 13 can supply liquid to the liquid nozzle 12 from the liquid receiving section 25 installed on the mounting section 19. The liquid flows in the supply flow path 20 in the supply direction Ds.

[0024] The mounting section 19 can be detachably mounted with a liquid container 25. The liquid container 25 contains liquid.

[0025] The upstream end of the supply flow path 20 in the supply direction Ds is connected to the liquid container 25. The upstream end of the supply flow path 20 may be provided in the mounting portion 19. By connecting to the liquid container 25 mounted in the mounting portion 19, the supply flow path 20 can discharge the liquid contained in the liquid container 25. The downstream end of the supply flow path 20 in the supply direction Ds is connected to the liquid nozzle 12. The supply flow path 20 supplies liquid to the liquid nozzle 12.

[0026] The first liquid delivery unit 21 delivers liquid in the supply direction Ds. The first liquid delivery unit 21 pressurizes and supplies liquid to the liquid nozzle 12. The first liquid delivery unit 21 may include a first check valve 27, a supply pump 28 (an example of a liquid pump), a second check valve 29, a first drive motor 30 (an example of a drive motor), and a first measuring unit 31 (an example of a measuring unit).

[0027] The first check valve 27 is located upstream of the supply pump 28. The second check valve 29 is located downstream of the supply pump 28. The first check valve 27 and the second check valve 29 allow liquid to flow downstream in the supply direction Ds and restrict liquid flow upstream in the supply direction Ds.

[0028] A supply pump 28 is located in the supply flow path 20. The supply pump 28 may be located between the first check valve 27 and the second check valve 29. The supply pump 28 is, for example, a diaphragm pump.

[0029] The first drive motor 30 drives the supply pump 28.

[0030] The first measuring unit 31 measures the current flowing in the first drive motor 30 and outputs the current value. The first measuring unit 31 can also indirectly measure the current flowing in the first drive motor 30. For example, the first measuring unit 31 can measure the current flowing in a circuit connected to the first drive motor 30. The first measuring unit 31 can also measure the voltage of the circuit connected to the first drive motor 30 and calculate the current value based on the measured voltage.

[0031] A buffer 22 is located downstream of the first liquid delivery section 21. The buffer 22 stores liquid. One side of the buffer 22 is formed of a flexible membrane, for example. The volume of liquid stored in the buffer 22 is variable. The buffer 22 stabilizes the pressure of the liquid flowing in the supply path 20.

[0032] The pressure regulating valve 23 stabilizes the pressure of the liquid supplied to the nozzle 16 by adjusting the pressure of the pressurized liquid. The pressure regulating valve 23 can adjust the pressure of the liquid within the liquid nozzle 12 to the pressure required to form a meniscus in the nozzle 16. The pressure regulating valve 23 can also open the supply flow path 20 when the downstream pressure is lower than a predetermined pressure.

[0033] Security system

[0034] The maintenance system 14 may include a cover 33, a discharge path 34 as an example of a liquid flow path, and a second liquid delivery section 35. The maintenance system 14 maintains the liquid nozzle 12. The maintenance system 14 can perform suction cleaning to discharge liquid from the nozzle 16. The maintenance system 14 transports the liquid discharged from the liquid nozzle 12 to the waste liquid container 36. The waste liquid container 36 may be detachably installed relative to the recording device 11. The liquid flows in the discharge direction Dd on the discharge path 34.

[0035] The cap 33, by contacting the liquid nozzle 12, can form a sealed space covering the nozzle 16. Forming a sealed space can also be referred to as sealing the liquid nozzle 12.

[0036] The upstream end of the discharge direction Dd in the discharge flow path 34 is connected to the cover 33, and the downstream end of the discharge direction Dd is connected to the waste liquid container 36. The discharge flow path 34 may be composed of a component (e.g., a pipe) that can deform as the cover 33 moves.

[0037] The second liquid delivery unit 35 may include a suction pump 38 (e.g., a liquid pump), a second drive motor 39 (e.g., a drive motor), and a second measuring unit 40 (e.g., a measuring unit). The second liquid delivery unit 35 discharges liquid from the liquid nozzle 12 by creating a negative pressure inside a cover 33 that seals the liquid nozzle 12. The cover 33 can receive liquid discharged from the nozzle 16. A discharge flow path 34 allows the liquid discharged from the liquid nozzle 12 to flow.

[0038] A suction pump 38 is located in the discharge flow path 34. The suction pump 38 is, for example, a tubular pump.

[0039] The second drive motor 39 drives the suction pump 38.

[0040] The second measuring unit 40 measures the current flowing in the second drive motor 39 and outputs the current value. The second measuring unit 40 can also indirectly measure the current flowing in the second drive motor 39. For example, the second measuring unit 40 can measure the current flowing in a circuit connected to the second drive motor 39. The second measuring unit 40 can also measure the voltage of the circuit connected to the second drive motor 39 and calculate the current value based on the measured voltage.

[0041] The recording device 11 may also include a notification unit 42. The notification unit 42, for example, can notify the user of information. The notification unit 42 can separately notify information related to the supply system 13 and information related to the security system 14. Therefore, it can be said that the supply system 13 and the security system 14 each have a notification unit 42.

[0042] The notification unit 42 can be a monitor that displays images and text, or a touch panel capable of displaying and operating. The notification unit 42 can also be a speaker that emits sounds, or a ringtone. The notification unit 42 can also be a light that emits light or flashes. The notification unit 42 can also be a communication unit that communicates with external devices such as smartphones, personal computers, and servers to notify those external devices of information.

[0043] The recording device 11 includes a control unit 43. The control unit 43 can control various major operations performed in the recording device 11. The control unit 43 uniformly controls the driving of each mechanism in the supply system 13 and the security system 14. Therefore, it can be said that the supply system 13 and the security system 14 each include a control unit 43.

[0044] The control unit 43 is configured to include circuitry comprising: (α) one or more processors that execute various processes according to a computer program; (β) one or more dedicated hardware circuits that execute at least a portion of the various processes; or (γ) combinations thereof. The hardware circuitry may be, for example, an application-specific integrated circuit. The processor includes a CPU and memories such as RAM and ROM, which store program code or instructions configured to cause the CPU to execute processes. Memory is a computer-readable medium, encompassing all readable media accessible by a general-purpose or special-purpose computer.

[0045] First anomaly detection method

[0046] Either or both of the supply system 13 and the maintenance system 14 can execute a first anomaly detection method, which is an example of an anomaly detection method. The first anomaly detection methods of the supply system 13 and the maintenance system 14 are basically the same. That is, if the supply flow path 20, the supply pump 28, the first drive motor 30, and the first measuring unit 31 are replaced with the discharge flow path 34, the suction pump 38, the second drive motor 39, and the second measuring unit 40, then the first anomaly detection method of the supply system 13 becomes the first anomaly detection method of the maintenance system 14. Therefore, in this embodiment, the first anomaly detection method executed by the supply system 13 will be described, and the description of the first anomaly detection method executed by the maintenance system 14 will be omitted.

[0047] Figure 2 This graph shows the change in current value measured by the first measuring unit 31, with the start time of the supply pump 28 being 0. The solid line represents an example of current value measured when the liquid flows normally through the supply path 20. The dashed line represents an example of current value measured when the supply path 20 is bent or blocked, causing an abnormality in the supply path 20.

[0048] The start-up time range TRa, the reference range IR, and the determination time point td can be pre-stored by the control unit 43. The start-up time range TRa, the reference range IR, and the determination time point td can be pre-set based on the current values ​​measured when the supply pump 28 and the supply flow path 20 are in normal conditions.

[0049] The start-up time range TRa is the time period immediately after the supply pump 28 starts, a period during which surge current exceeding the rated current may flow. The reference range IR is set to include the maximum value of the surge current. The judgment time point td is the time point after the pressure in the supply flow path 20 stabilizes. The judgment time point td can also be set to the time point after the buffer 22 is filled with liquid.

[0050] like Figure 3 As shown, the control unit 43 executes the first anomaly detection procedure. For example, the control unit 43 can coordinate with the initialization process after the recording device 11 is started to cause the supply system 13 to execute the first anomaly detection procedure. The control unit 43 can also cause the supply system 13 to execute the first anomaly detection procedure before recording the medium 17.

[0051] In step S101, the control unit 43 sets the starting current value. The control unit 43 sets the maximum value among the multiple current values ​​output by the first measuring unit 31 within the starting time region TRa as the starting current value.

[0052] In steps S102 and S103, the control unit 43 determines whether the starting current value is within the reference range IR. If the starting current value is within the reference range IR, the control unit 43 transfers the processing to step S104. That is, in step S102, the control unit 43 compares the maximum value in the reference range IR (i.e., the reference maximum value) with the starting current value. If the starting current value is below the reference maximum value, then step S102 is true, and the control unit 43 transfers the processing to step S103. In step S103, the control unit 43 compares the minimum value in the reference range IR (i.e., the reference minimum value) with the starting current value. If the starting current value is above the reference minimum value, then step S103 is true, and the control unit 43 transfers the processing to step S104.

[0053] In step S104, the control unit 43 will Figure 2 The start time point ts of the calculation time region TRo shown is set before the determination time point td. The control unit 43 sets the start time point ts after the start time region TRa. The calculation time region TRo is the time region after the start time region TRa. The calculation time region TRo is the time region during which the current flowing in the first drive motor 30 stabilizes.

[0054] In step S105, the control unit 43 will Figure 2 The end time point te of the computation time region TR0 shown is set to the time difference between the determination time point td and the start time point ts, which is later than the determination time point td. That is, the control unit 43 sets the computation time region TR0 with the determination time point td located in the center.

[0055] In step S106, the control unit 43 performs calculations on multiple current values ​​output by the first measurement unit 31 within the calculation time region Tro to set a judgment value. The control unit 43 can set the judgment value by averaging the multiple current values ​​output by the first measurement unit 31 within the calculation time region Tro.

[0056] In step S107, the control unit 43 compares the starting current value with the determination value. If the determination value is less than the starting current value, step S107 is true, and the control unit 43 transfers the processing to step S108.

[0057] In step S108, the control unit 43 sets a warning threshold. The control unit 43 can set the warning threshold by multiplying the starting current value by a warning ratio. The warning threshold is a value less than the starting current value.

[0058] In step S109, the control unit 43 compares the determined value with the warning threshold. If the determined value is less than the warning threshold, step S109 is "yes", and the control unit 43 ends the process.

[0059] In steps S102 and S103, if the starting current value is not included in the reference range IR, the control unit 43 transfers the processing to step S110. That is, if the starting current value is greater than the reference maximum value, step S102 is negative, and the control unit 43 transfers the processing to step S110. If the starting current value is less than the reference minimum value, step S103 is negative, and the control unit 43 transfers the processing to step S110. In step S110, the control unit 43 determines that the supply pump 28 has malfunctioned, issues a warning, and terminates the processing.

[0060] In step S107, if the determined value is above the starting current value, then step S107 is negative, and the control unit 43 transfers the processing to step S111. In step S111, the control unit 43 determines that an abnormality has occurred in the supply flow path 20, issues a warning, and terminates the processing.

[0061] In step S109, if the determined value is above the warning threshold, then step S109 is negative, and the control unit 43 transfers the processing to step S112. In step S112, the control unit 43 determines that an abnormality in the supply flow path 20 is predicted, issues a warning, and ends the processing.

[0062] Second anomaly detection method

[0063] Either or both of the supply system 13 and the maintenance system 14 can execute a second anomaly detection method as an example of an anomaly detection method. The second anomaly detection methods of the supply system 13 and the maintenance system 14 are basically the same. In this embodiment, the second anomaly detection method executed by the maintenance system 14 will be described, and the description of the second anomaly detection method executed by the supply system 13 will be omitted. If the discharge flow path 34, the suction pump 38, the second drive motor 39, and the second measuring unit 40 are replaced with the supply flow path 20, the supply pump 28, the first drive motor 30, and the first measuring unit 31, then the second anomaly detection method of the maintenance system 14 becomes the second anomaly detection method of the supply system 13.

[0064] Figure 4 This graph shows the change in current value measured by the second measuring unit 40, with the starting time of the suction pump 38 being 0. The solid line represents an example of current value measured when, for example, the liquid discharged from the nozzle 16 is normally delivered to the waste liquid container 36 via suction cleaning. The dashed line represents an example of current value measured when the liquid delivery of the discharge flow path 34 is abnormal due to a bend or blockage in the discharge flow path 34.

[0065] The initial time point ti, the reference range IR, and one or more measurement time points tm can be stored in advance by the control unit 43. The initial time point ti, the reference range IR, and an abnormal measurement time point tm can be preset based on the current values ​​measured when the suction pump 38 and the discharge flow path 34 are in normal conditions.

[0066] The initial time point ti can be the time point at which the maximum value of the surge current is measured, or the time point at which the surge current is predicted to reach its maximum.

[0067] The reference range IR is set to include the maximum value of the surge current. The reference range IR of the suction pump 38 may be the same as or different from the reference range IR of the supply pump 28.

[0068] The measurement time point tm is a time point after the initial time point ti. The measurement time point tm is set at the time point after the pressure in the discharge flow path 34 has stabilized. Multiple measurement time points tm can be set separately at equal time intervals. The interval between multiple measurement time points tm can be the drive interval of the suction pump 38. For example, in the case where the suction pump 38 is a pipe pump that delivers liquid by squeezing and moving the pipe constituting the discharge flow path 34 through multiple rollers, the time point at which each roller begins to squeeze the pipe can be used as the measurement time point tm.

[0069] like Figure 5 As shown, the control unit 43 can, for example, cause the maintenance system 14 to execute a second abnormality detection procedure during suction cleaning.

[0070] In step S201, the control unit 43 sets the starting current value. The control unit 43 sets the current value output by the second measuring unit 40 at the initial time point ti as the starting current value.

[0071] In steps S202 and S203, the control unit 43 determines whether the starting current value is included within the reference range IR. In step S202, the control unit 43 compares the maximum value (i.e., the reference maximum value) in the reference range IR with the starting current value. In step S203, the control unit 43 compares the minimum value (i.e., the reference minimum value) in the reference range IR with the starting current value.

[0072] In steps S202 and S203, if the starting current value is not included in the reference range IR, the control unit 43 transfers the processing to step S204. That is, if the starting current value is greater than the reference maximum value, step S202 is negative, and the control unit 43 transfers the processing to step S204. If the starting current value is less than the reference minimum value, step S203 is negative, and the control unit 43 transfers the processing to step S204. In step S204, the control unit 43 determines that the suction pump 38 has malfunctioned, issues a warning, and terminates the processing.

[0073] If the starting current value is within the reference range IR, the control unit 43 transfers the processing to step S205. That is, if the starting current value is below the maximum reference value, then step S202 is true, and the control unit 43 transfers the processing to step S203. If the starting current value is above the minimum reference value, then step S203 is true, and the control unit 43 transfers the processing to step S205.

[0074] In step S205, the control unit 43 may also use the initial time point ti and the starting current value, the measurement time point tm and the current value at the measurement time point tm to calculate the slope of the linear function.

[0075] For example, the control unit 43 can average multiple current values ​​output by the second measurement unit 40 at multiple measurement time points tm to obtain a judgment value. The control unit 43 can compare the judgment value and the starting current value to obtain the slope of a linear function. For example, the linear function can be a formula for a straight line passing through the initial time point ti, the starting current value, a measurement time point tm, and the judgment value. A measurement time point tm can be the measurement time point tm located in the middle of the time series among multiple measurement time points tm.

[0076] A linear function can also be obtained by applying the least squares method to the initial time point ti, the starting current value, multiple measurement time points tm, and the current values ​​measured at each measurement time point tm. When using the least squares method, abnormalities in the discharge flow path 34 are easily reflected in the slope. Therefore, even when the change in current value is small when an abnormality occurs in the discharge flow path 34, the accuracy of determining whether an abnormality exists can be improved.

[0077] In step S206, the control unit 43 determines whether the slope of the linear function is less than 0. If the slope is less than 0, then step S206 is true, and the control unit 43 ends the process. That is, if the determined value is less than the starting current value, the control unit 43 ends the process.

[0078] If the slope is greater than or equal to 0, then step S206 is incorrect, and the control unit 43 transfers the processing to step S207. In step S207, the control unit 43 determines that an abnormality has occurred in the discharge flow path 34, issues a warning, and terminates the processing.

[0079] The function of this implementation method

[0080] The function of this embodiment will be explained.

[0081] The control unit 43 determines whether the supply pump 28 or the suction pump 38 is abnormal based on whether the starting current value is included in the reference range IR.

[0082] The control unit 43 determines whether there is an abnormality in the supply flow path 20 by comparing the starting current value with the judgment value. The control unit 43 can also predict abnormalities in the supply flow path 20 by comparing the judgment value of the supply system 13 with a warning threshold. The control unit 43 can determine that the supply flow path 20 is normal if the judgment value is less than the warning threshold. The control unit 43 can determine that an abnormality in the supply flow path 20 is predicted if the judgment value is above the warning threshold and less than the starting current value. A predicted abnormality means, for example, a decrease in the flow of the supply flow path 20 or a high probability of blockage in the supply flow path 20 in the near future. The control unit 43 can determine that an abnormality has occurred in the supply flow path 20 if the judgment value is above the starting current value.

[0083] The control unit 43 determines whether there is an abnormality in the discharge flow path 34 by comparing the starting current value with the current value at the measurement time point tm. The control unit 43 can compare the determination value with the starting current value to determine whether there is an abnormality in the discharge flow path 34; this determination value is obtained by averaging the current values ​​at multiple measurement time points tm. The control unit 43 can determine that the discharge flow path 34 is abnormal if the determination value is above the starting current value. The control unit 43 can determine that the discharge flow path 34 is normal if the determination value is below the starting current value.

[0084] The control unit 43 can also use the initial time point ti, the starting current value, one or more measurement time points tm, and the current value at measurement time point tm to calculate the slope of a linear function. The control unit 43 can determine that the discharge flow path 34 is normal if the calculated slope is less than 0. The control unit 43 can determine that the discharge flow path 34 is abnormal if the calculated slope is greater than 0.

[0085] The control unit 43 can cause the notification unit 42 to issue a warning if it determines that an abnormality has occurred. The control unit 43 can also stop driving the supply pump 28 and the suction pump 38 if it determines that an abnormality has occurred. The control unit 43 can cause the notification unit 42 to issue a warning if it determines that an abnormality is predicted.

[0086] Effects of this implementation method

[0087] The effects of this implementation method will be explained.

[0088] (1-1) The current flowing in the first drive motor 30 exhibits characteristics not only when there is an anomaly in the supply flow path 20, but also when there is an anomaly in the supply pump 28. Regarding this, anomalies in the supply pump 28 can be detected by comparing the starting current value with a reference range IR. Anomaly detection in the supply flow path 20 is performed by comparing the starting current value with a determination value. The determination value is obtained by processing multiple current values ​​within the calculation time region TR0. That is, the determination value is set to account for individual differences in the supply pump 28, thus enabling anomalies to be detected while minimizing the influence of individual differences in the supply pump 28.

[0089] (1-2) The decision value is the average of multiple current values ​​within the operation time region TRo. Therefore, compared to, for example, setting a single current value as the decision value, the impact of noise can be reduced.

[0090] (1-3) By comparing the starting current value with the warning threshold, abnormalities in the supply flow path 20 are predicted. By predicting abnormalities in the supply flow path 20, preparations can be made for the occurrence of abnormalities in the supply flow path 20.

[0091] (1-4) A warning is issued when the judgment value is above the warning threshold. Specifically, if the judgment value is above the warning threshold but below the starting current value, a warning is issued predicting an abnormality in the supply flow path 20. If the judgment value is above the starting current value, a warning is issued that an abnormality has occurred in the supply flow path 20. Therefore, the status of the supply flow path 20 can be notified.

[0092] (1-5) The operation time region TRO has an equal time width before and after the decision time point td. Therefore, the deviation of the current value measured within the operation time region TRO can be reduced. Therefore, the accuracy of the decision value determined based on the current value measured within the operation time region TRO can be improved.

[0093] (1-6) By comparing the starting current value with the reference range IR, abnormalities in the suction pump 38 can be detected. Abnormalities in the discharge path 34 are determined by comparing the current value at the initial time point ti (i.e., the starting current value) with the current value at the measurement time point tm. Since the starting current value and the current value at the measurement time point tm vary due to individual differences in the suction pump 38, abnormalities can be detected while minimizing the impact of these individual differences.

[0094] (1-7) The slope of the linear function is calculated using the initial time point ti, the starting current value, the measurement time point tm, and the current value at measurement time tm. The slope is then used to determine whether there is an abnormality in the discharge flow path 34. Therefore, even if the change in current value is small when an abnormality occurs in the discharge flow path 34, it is possible to determine whether there is an abnormality in the discharge flow path 34.

[0095] (1-8) The decision value is the average of multiple current values ​​output at multiple measurement time points tm. Therefore, compared to, for example, setting a single current value as the decision value, the influence of noise can be reduced.

[0096] (1-9) The current flowing in the second drive motor 39 may sometimes change in conjunction with the drive interval of the suction pump 38. Regarding this, the interval between multiple measurement time points tm is the drive interval of the suction pump 38. Therefore, the deviation of the measured current value can be reduced.

[0097] Change Example

[0098] This embodiment can be modified and implemented in the following ways. This embodiment and the following modifications can be combined and implemented within the scope of technical non-conflict.

[0099] Supply system 13 and maintenance system 14 can execute a first anomaly detection method. Supply system 13 and maintenance system 14 can also execute a second anomaly detection method. Alternatively, supply system 13 can execute the second anomaly detection method, and maintenance system 14 can execute the first anomaly detection method. For example, control unit 43 can set the current value output by first measurement unit 31 at initial time point ti as the starting current value. Control unit 43 can also set a judgment value by averaging multiple current values ​​output by first measurement unit 31 at multiple measurement time points tm. Control unit 43 can also determine whether there is an anomaly in supply flow path 20 based on whether the slope of a linear function passing through initial time point ti, starting current value, measurement time point tm, and judgment value is greater than or equal to 0. For example, control unit 43 can also set the maximum value among multiple current values ​​output by second measurement unit 40 within the starting time region TRa as the starting current value. Control unit 43 can also set a judgment value by averaging multiple current values ​​output by second measurement unit 40 within the operation time region TRo. The control unit 43 can also determine whether there is any abnormality in the discharge flow path 34 based on whether the judgment value is above the starting current value.

[0100] The control unit 43 can store slope warning values. A slope warning value is a value less than 0 and closer to 0 than the normal slope. The control unit 43 can also predict abnormalities in the supply flow path 20 and the discharge flow path 34 by comparing the slope of the calculated linear function with the slope warning value. That is, if the slope is less than 0 and above the slope warning value, it can be determined that an abnormality in the supply flow path 20 or the discharge flow path 34 is predicted. The control unit 43 can also determine that the supply flow path 20 or the discharge flow path 34 is normal if the calculated slope is less than the slope warning value.

[0101] The time intervals between multiple measurement time points tm are not limited to equal intervals; they can also be biased.

[0102] The control unit 43 can pre-store the calculation time region TR0. The control unit 43 can set the determination time point td at, for example, the center of the calculation time region TR0.

[0103] The operation time region TR0 can be the region immediately following the startup time region TRa. TR0 can include a period of unstable current value (i.e., the unstable region). TR0 can also include a period of stable current value (i.e., the stable region). When TR0 includes an unstable region, the stable region should preferably be longer than the unstable region.

[0104] The determination time point td can also be a time point that deviates from the center of the operation time region Tro.

[0105] The control unit 43 may also not set a warning threshold. The control unit 43 may also not predict anomalies in the supply flow path 20.

[0106] The control unit 43 can set a current value output by the first measuring unit 31 or the second measuring unit 40 within the operation time region TRo as a judgment value. The control unit 43 can also set one of a plurality of current values ​​output by the first measuring unit 31 or the second measuring unit 40 within the operation time region TRo as a judgment value.

[0107] The liquid can be colored ink containing colorants, or a protective liquid that protects an image formed by the ink. The liquid can also be a moisturizing liquid, for example, for moisturizing the cover 33. The liquid can also be a wiping liquid used to wet a wiper (not shown) of the wiping liquid nozzle 12. The liquid can also be a cleaning liquid used to clean the wiper, etc. The liquid supply system can supply moisturizing liquid to the cover 33. The liquid supply system can also supply wiping liquid or cleaning liquid to the wiper.

[0108] The recording device 11 can be a liquid jetting device that records by spraying or ejecting liquids other than ink. The state of the liquid ejected from the liquid jetting device in the form of tiny droplets includes granular, teardrop-like, and filamentous tails. The liquid referred to here can be any material that can be ejected from the liquid jetting device. For example, the liquid can be any substance in a liquid phase, including liquids with high or low viscosity, sols, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals, molten metals, and other fluids. Liquids include not only liquids in a physical state but also substances formed by dissolving, dispersing, or mixing functional material particles composed of solids such as pigments and metal particles in a solvent. Representative examples of liquids include inks and liquid crystals described in the above embodiments. Here, inks include general water-based inks and oil-based inks, as well as various liquid compositions such as gel inks and hot-melt inks. Specific examples of liquid jetting devices include those that jet materials such as electrode materials and coloring materials used in the manufacture of liquid crystal displays, electroluminescent displays, surface-emitting displays, and color filters in a dispersed or dissolved form. Liquid jetting devices can also be used to jet bio-organic substances for biochip manufacturing, to jet liquids as samples using precision pipettes, to print and dye, or to dispense microdispensers. Liquid jetting devices can also be used to precisely jet lubricating oil onto precision machinery such as watches and cameras, or to jet transparent resin liquids such as UV-curable resins onto a substrate to form micro-hemispherical lenses and optical lenses for optical communication components. Liquid jetting devices can also be used to jet etching solutions such as acids or alkalis to etch substrates.

[0109] definition

[0110] As used in this specification, the term "at least one" means "one or more" of the desired options. For example, when there are two options, "at least one" means "only one option" or "both options". As another example, when there are three or more options, "at least one" means "only one option", "any combination of two options", or "any combination of three or more options".

[0111] Postscript

[0112] The technical concepts and their effects, as understood based on the above embodiments and variations, are described below.

[0113] [1] The anomaly detection method is an anomaly detection method for a recording device, the recording device comprising: a liquid nozzle for spraying liquid into a medium for recording; a liquid flow path for supplying liquid flow; a liquid pump disposed in the liquid flow path; a drive motor for driving the liquid pump; and a measuring unit for measuring the current flowing in the drive motor and outputting a current value, the anomaly detection method comprising: setting the maximum value among a plurality of current values ​​output by the measuring unit within a startup time period as a startup current value; determining whether the liquid pump is abnormal based on whether the startup current value is included in a reference range; performing calculation processing on a plurality of current values ​​output by the measuring unit within a calculation time period after the startup time period to set a determination value; and determining whether the liquid flow path is abnormal by comparing the startup current value with the determination value.

[0114] The current flowing in the drive motor exhibits characteristics not only when there are abnormalities in the liquid flow path but also when there are abnormalities in the liquid pump. Regarding this, this method allows for the detection of liquid pump abnormalities by comparing the starting current value with a reference range. The determination of liquid flow path abnormalities is performed by comparing the starting current value with a judgment value. The judgment value is obtained by processing multiple current values ​​within the calculation time region. That is, the judgment value is set to account for the individual differences of the liquid pump, thus enabling the detection of abnormalities while minimizing the influence of individual liquid pump variations.

[0115] [2] In the above [1] anomaly detection method, optionally, the calculation time region is the time region in which the current flowing in the drive motor is stable, and the judgment value is set by averaging the multiple current values ​​output by the measuring unit in the calculation time region.

[0116] According to this method, the decision value is the average of multiple current values ​​over the computation time period. Therefore, compared to, for example, setting a single current value as the decision value, the influence of noise can be reduced.

[0117] [3] Optionally, the abnormality detection method of [1] or [2] above includes: multiplying the starting current value by a warning ratio to set a warning threshold; and predicting the abnormality of the liquid flow path by comparing the judgment value with the warning threshold.

[0118] According to this method, anomalies in the liquid flow path are predicted by comparing the starting current value with a warning threshold. By predicting anomalies in the liquid flow path, preparations can be made for their occurrence.

[0119] [4] Optionally, the anomaly detection method of [3] above includes: determining that the liquid flow path is normal when the determination value is less than the warning threshold; determining that the liquid flow path is predicted to be abnormal when the determination value is above the warning threshold and the determination value is less than the starting current value, and issuing a warning; and determining that the liquid flow path is abnormal when the determination value is above the starting current value, and issuing a warning.

[0120] According to this method, a warning is issued when the judgment value exceeds a warning threshold. Specifically, if the judgment value is above the warning threshold but less than the starting current value, a warning is issued predicting an anomaly in the liquid flow path. If the judgment value is above the starting current value, a warning is issued indicating an anomaly in the liquid flow path. Therefore, the status of the liquid flow path can be communicated.

[0121] [5] In any of the above [1] to [4] anomaly detection methods, optionally, the determination time point is the time point after the pressure of the liquid flow path stabilizes, and the anomaly detection method includes: setting the start time point of the calculation time region before the determination time point; and setting the end time point of the calculation time region to a time point later than the determination time point than the time difference between the determination time point and the start time point.

[0122] According to this method, the computation time region has an equal time width before and after the decision time point. Therefore, the deviation of the current value measured within the computation time region can be reduced. Consequently, the accuracy of the decision value determined based on the current value measured within the computation time region can be improved.

[0123] [6] The liquid flow system includes: a liquid flow path for supplying liquid to or discharging from a liquid nozzle, wherein the liquid nozzle sprays liquid into a medium for recording; a liquid pump disposed in the liquid flow path; a drive motor for driving the liquid pump; a measuring unit for measuring the current flowing in the drive motor and outputting a current value; and a control unit that sets the maximum value among multiple current values ​​output by the measuring unit within a start-up time period as a start-up current value, determines whether the liquid pump is malfunctioning based on whether the start-up current value is within a reference range, performs calculations on multiple current values ​​output by the measuring unit within a calculation time period after the start-up time period to set a determination value, and determines whether the liquid flow path is malfunctioning by comparing the start-up current value with the determination value. Based on this configuration, the same effect as the above-described anomaly detection method can be achieved.

[0124] [7] The recording device includes: a liquid ejector head for spraying liquid into a medium for recording; a liquid flow path for supplying liquid flow; a liquid pump disposed in the liquid flow path; a drive motor for driving the liquid pump; a measuring unit for measuring the current flowing in the drive motor and outputting a current value; and a control unit that sets the maximum value among multiple current values ​​output by the measuring unit within a start-up time period as a start-up current value, determines whether the liquid pump is abnormal based on whether the start-up current value is included within a reference range, performs calculation processing on multiple current values ​​output by the measuring unit within an operation time period after the start-up time period, sets a determination value, and determines whether the liquid flow path is abnormal by comparing the start-up current value with the determination value. Based on this configuration, the same effect as the above-described anomaly detection method can be achieved.

[0125] [8] The anomaly detection method is an anomaly detection method for a recording device, the recording device comprising: a liquid nozzle for spraying liquid into a medium for recording; a liquid flow path for liquid flow; a liquid pump disposed in the liquid flow path; a drive motor for driving the liquid pump; and a measuring unit for measuring the current flowing in the drive motor and outputting a current value, the anomaly detection method comprising: setting the current value output by the measuring unit at an initial time point as a starting current value; determining whether the liquid pump is abnormal based on whether the starting current value is included in a reference range; and determining whether the liquid flow path is abnormal by comparing the starting current value with the current value output by the measuring unit at a measurement time point after the initial time point.

[0126] According to this method, abnormalities in the liquid pump can be detected by comparing the starting current value with a reference range. Abnormalities in the liquid flow path are determined by comparing the current value at the initial time point (starting current value) with the current value at the measurement time point. Since the starting current value and the current value at the measurement time point vary due to individual differences in liquid pumps, abnormalities can be detected while minimizing the influence of these individual differences.

[0127] [9] Optionally, the abnormality detection method of [8] above uses the initial time point, the starting current value, the measurement time point, and the current value output by the measuring unit at the measurement time point to calculate the slope of the linear function. If the slope is less than 0, the liquid flow path is determined to be normal. If the slope is greater than 0, the liquid flow path is determined to be abnormal.

[0128] According to this method, the slope of a linear function is calculated using the initial time point, the starting current value, the measurement time point, and the current value at the measurement time point. The slope is then used to determine whether there is an abnormality in the liquid flow path. Therefore, even if the change in current value is small when an abnormality occurs in the liquid flow path, it is possible to determine whether there is an abnormality.

[0129]

[10] In the above-mentioned [8] or [9] abnormality detection method, optionally, the determination value is compared with the starting current value to determine whether there is an abnormality in the liquid flow path, wherein the determination value is obtained by averaging the multiple current values ​​output by the measuring unit at multiple measurement time points.

[0130] According to this method, the decision value is the average of multiple current values ​​output at multiple measurement time points. Therefore, compared to, for example, setting a single current value as the decision value, the influence of noise can be reduced.

[0131]

[11] In the above-mentioned

[10] anomaly detection method, optionally, the interval between the plurality of measurement time points is the driving interval of the liquid pump.

[0132] The current flowing in the drive motor can sometimes vary in conjunction with the drive interval of the liquid pump. Regarding this, according to this method, the interval between multiple measurement time points is the drive interval of the liquid pump. Therefore, the deviation of the measured current value can be reduced.

Claims

1. An anomaly detection method, characterized in that, It is a method for detecting abnormalities in recording devices. The recording device includes: A liquid ejector head sprays liquid into the medium for recording purposes; Liquid flow path, for supplying liquid flow; A liquid pump is installed in the liquid flow path; The drive motor drives the liquid pump; as well as The measuring unit measures the current flowing in the drive motor and outputs the current value. The anomaly detection method includes: The maximum value among the multiple current values ​​output by the measuring unit within the startup time region is set as the startup current value; Determine whether the liquid pump is malfunctioning based on whether the starting current value is within the reference range; A judgment value is set by performing calculations on multiple current values ​​output by the measurement unit within the calculation time period following the start-up time region; and The presence or absence of abnormalities in the liquid flow path is determined by comparing the starting current value with the judgment value.

2. The anomaly detection method according to claim 1, characterized in that, The calculation time region is the time period during which the current flowing in the drive motor is stable. The determination value is set by averaging the multiple current values ​​output by the measurement unit within the calculation time period.

3. The anomaly detection method according to claim 2, characterized in that, The anomaly detection method includes: The warning threshold is set by multiplying the starting current value by the warning ratio; and Anomalies in the liquid flow path are predicted by comparing the determination value with the warning threshold.

4. The anomaly detection method according to claim 3, characterized in that, The anomaly detection method includes: If the judgment value is less than the warning threshold, the liquid flow path is determined to be normal; If the judgment value is above the warning threshold and below the starting current value, it is determined that an abnormality is predicted in the liquid flow path, and a warning is issued; and If the determination value is higher than the starting current value, it is determined that the liquid flow path has malfunctioned, and a warning is issued.

5. The anomaly detection method according to claim 1, characterized in that, The determination time point is the time point after the pressure in the liquid flow path stabilizes. The anomaly detection method includes: The start time point of the computation time region is set before the determination time point; and The end time of the calculation time region is set to the time point that is later than the determination time point, which is the time difference between the determination time point and the start time point.

6. A liquid flow system, characterized in that, have: A liquid flow path is provided for the flow of liquid supplied to or discharged from a liquid nozzle, which sprays liquid onto a medium for recording. A liquid pump is installed in the liquid flow path; The drive motor drives the liquid pump; The measuring unit measures the current flowing in the drive motor and outputs the current value; as well as Control Department The control unit sets the maximum value among the multiple current values ​​output by the measuring unit within the startup time period as the startup current value, and determines whether the liquid pump is malfunctioning based on whether the startup current value is within a reference range. The control unit performs calculations on multiple current values ​​output by the measurement unit during the calculation time period after the start-up time region to set a judgment value, and determines whether there is an abnormality in the liquid flow path by comparing the start-up current value with the judgment value.

7. A recording device, characterized in that, have: A liquid ejector head sprays liquid into the medium for recording purposes; Liquid flow path, for supplying liquid flow; A liquid pump is installed in the liquid flow path; The drive motor drives the liquid pump; The measuring unit measures the current flowing in the drive motor and outputs the current value; as well as Control Department The control unit sets the maximum value among the multiple current values ​​output by the measuring unit within the startup time period as the startup current value, and determines whether the liquid pump is malfunctioning based on whether the startup current value is within a reference range. The control unit performs calculations on multiple current values ​​output by the measurement unit during the calculation time period after the start-up time region to set a judgment value, and determines whether there is an abnormality in the liquid flow path by comparing the start-up current value with the judgment value.

8. An anomaly detection method, characterized in that, It is a method for detecting abnormalities in recording devices. The recording device includes: A liquid ejector head sprays liquid into the medium for recording purposes; Liquid flow path, for supplying liquid flow; A liquid pump is installed in the liquid flow path; The drive motor drives the liquid pump; as well as The measuring unit measures the current flowing in the drive motor and outputs the current value. The anomaly detection method includes: The current value output by the measuring unit at the initial time point is set as the starting current value; The presence or absence of abnormality in the liquid pump is determined by whether the starting current value is within the reference range. By comparing the starting current value with the current value output by the measuring unit at a measurement time point after the initial time point, it is determined whether there is any abnormality in the liquid flow path.

9. The anomaly detection method according to claim 8, characterized in that, Using the initial time point, the starting current value, the measurement time point, and the current value output by the measuring unit at the measurement time point, the slope of a linear function is calculated. If the slope is less than 0, the liquid flow path is determined to be normal; if the slope is greater than 0, the liquid flow path is determined to be abnormal.

10. The anomaly detection method according to claim 8 or 9, characterized in that, The determination value is compared with the starting current value to determine whether there is an abnormality in the liquid flow path. The determination value is obtained by averaging multiple current values ​​output by the measuring unit at multiple measurement time points.

11. The anomaly detection method according to claim 10, characterized in that, The interval between the multiple measurement time points is the driving interval of the liquid pump.

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