Image forming system, identification method, computer program, and recording medium

Abstract

This invention provides a technology for identifying the causes of anomalies that occur in image forming systems. [Solution] In the image forming system, the controller is configured to input a control variable to the motor driver to move the carriage at a target speed in the main scanning direction, based on the carriage's movement speed detected from the encoder signal. The motor driver is configured to drive the motor by applying drive power based on the control variable. The rotational motion of the motor is converted into the translational motion of the carriage. The controller is configured to detect abnormalities in the movement speed, physical quantities related to the movement speed, or the control variable as observed quantities observed by the carriage's movement control, and to identify the cause of the abnormality based on the area or time period in the carriage's movement path where the abnormality in the observed quantity was detected.

Description

Technical Field

[0001] The present disclosure relates to an image forming system and a specifying method.

Background Art

[0002] Conventionally, an image forming system in which a plurality of devices in a system are controlled based on a master signal is known (see, for example, Patent Document 1). As a technique related to this image forming system, there is known a technique for performing failure diagnosis of each device by performing frequency analysis in real time on the amount of variation in the rotational speed calculated from the comparison between the master signal and the feedback signal of each device.

[0003] Also, an image forming system that forms an image on a recording medium such as paper or clothing by discharging ink from a recording head is known. In this image forming system, operational abnormalities occur due to various factors such as deterioration of the motor, ink contamination, and wear of movable parts. Conventionally, for continuous use of this type of image forming system, system maintenance such as component replacement and cleaning has been performed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As mentioned above, conventional technology identifies the location of a failure through frequency analysis. However, some causes of failure cannot be detected by frequency analysis. For example, in a system that forms an image on a recording medium using ink droplets, ink droplets adhering to the encoder scale can cause abnormal detection of the carriage's position and velocity. Conventional technology using frequency analysis cannot identify the cause of such anomalies. In environments where identifying the cause of an anomaly takes time, system downtime is prolonged.

[0006] Therefore, according to one aspect of this disclosure, it is desirable to provide a novel technology for identifying the cause of abnormalities that occur in an image forming system configured to form an image by ejecting ink onto a recording medium. [Means for solving the problem]

[0007] According to one aspect of this disclosure, an image forming system is provided. The image forming system comprises a recording head, a carriage movement mechanism, a motor driver, an encoder, and a controller. The recording head is configured to eject ink onto a recording medium.

[0008] The carriage movement mechanism comprises a carriage on which the recording head is mounted, a motor, and a power conversion system that moves the carriage in the main scanning direction by converting the rotational motion of the motor into translational motion of the carriage.

[0009] The motor driver is configured to drive the motor. The encoder is configured to output an encoder signal in response to the change in position of the carriage in the main scanning direction.

[0010] The controller is configured to control the movement of the carriage by inputting an input variable to the motor driver, based on the carriage's movement speed detected from the encoder signal, to move the carriage in the main scanning direction at a target speed.

[0011] The motor driver is configured to drive the motor by applying drive power based on the manipulated variable. The controller is configured to detect anomalies in the moving speed, physical quantities related to the moving speed, or manipulated variable as observed quantities observed by the movement control of the carriage, and to identify the cause of the anomaly based on the area in the carriage's movement path where the anomaly in the observed quantity was detected or the time period in the carriage's movement process where the anomaly in the observed quantity was detected.

[0012] This image forming system makes it possible to appropriately identify the cause of abnormalities that occur in a configuration in which ink is ejected onto a recording medium to form an image.

[0013] According to another aspect of this disclosure, a method for identifying the cause of an anomaly in an image forming system may be provided. The image forming system comprises a recording head, a carriage movement mechanism, a motor driver, an encoder, and a controller.

[0014] The recording head is configured to eject ink onto the recording medium. The carriage movement mechanism includes a carriage on which the recording head is mounted, a motor, and a power conversion system that moves the carriage in the main scanning direction by converting the rotational motion of the motor into translational motion of the carriage.

[0015] The motor driver is configured to drive the motor. The encoder is configured to output an encoder signal in response to the change in position of the carriage in the main scanning direction.

[0016] The controller is configured to control the movement of the carriage by inputting a manipulated variable to the motor driver, based on the carriage's movement speed detected from the encoder signal, to move the carriage at a target speed in the main scanning direction. The motor driver is configured to drive the motor by applying drive power based on the manipulated variable.

[0017] The specific method includes detecting an abnormality in an observed quantity based on a moving speed as an observed quantity observed by controlling the movement of a carriage, a physical quantity related to the moving speed, or an operation quantity. The specific method further includes specifying the cause of the abnormality based on an area where an abnormality in the observed quantity is detected in the moving path of the carriage or a time period in which an abnormality in the observed quantity is detected during the movement process of the carriage.

[0018] According to this specific method, it is possible to appropriately specify the cause of an abnormality occurring in an image forming system configured to form an image by discharging ink onto a recording medium.

[0019] According to another aspect of the present disclosure, there may be provided a computer program for causing a computer to execute the above-described specific method. There may be provided a computer-readable recording medium on which the computer program is recorded.

Brief Description of the Drawings

[0020] [Figure 1] It is a diagram showing the mechanical configuration of an image forming system. [Figure 2] It is a diagram showing the electrical configuration of an image forming system. [Figure 3] It is a flowchart showing job-related processing executed by a main control unit. [Figure 4] It is a flowchart showing maintenance-related processing executed by a main control unit. [Figure 5] It is a flowchart showing cause-specifying processing executed by a main control unit. [Figure 6] It is a graph of time vs. index value showing the transition of an index value. [Figure 7] FIGS. 7A and 7B are graphs for explaining changes in speed or voltage command values according to different causes of abnormalities. <X [Figure 8] FIG. 8A is a graph for explaining the change in time vs. peak observed value when the peak observed value changes gently, and FIG, 8B is a graph for explaining the change in time vs. peak observed value when the peak observed value changes steeply. [Figure 9]It is an explanatory diagram regarding the determination of remaining life and the identification of the cause of abnormality using a server device. [Figure 10] It is a diagram for explaining a method for identifying the cause of abnormality in a modified example.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. The image forming system 1 of the present embodiment shown in FIG. 1 is an inkjet printer that forms an image on an object P as a recording medium placed on a platen 10 by ejecting ink. Specifically, the object P is clothing. That is, the image forming system 1 is configured as a garment printer.

[0022] The image forming system 1 includes, in addition to the platen 10, a recording head 20, an ink tank 21, an ink supply tube (hereinafter simply referred to as "tube") 25, a carriage movement mechanism 30, a linear encoder 40, and a controller 50.

[0023] The recording head 20 is an inkjet head and is configured to eject ink onto the object P arranged opposite. A plurality of nozzles for ejecting ink droplets are arranged in the recording head 20. The recording head 20 is connected via the ink tank 21 and the tube 25. The ink tank 21 is configured to supply ink to the recording head 20 via the tube 25.

[0024] The carriage movement mechanism 30 includes a carriage 31, a belt mechanism 33, a shaft 35, a guide rail 37, and a carriage (CR) motor 39. The belt mechanism 33, the shaft 35, and the guide rail 37 correspond to a power conversion system.

[0025] The carriage 31 mounts the recording head 20. The carriage 31 reciprocates in the main scanning direction, powered by a CR motor 39 controlled by a controller 50. The recording head 20 moves in the main scanning direction in conjunction with the movement of the carriage 31.

[0026] The ink tank 21 is not mounted on the carriage 31 but is fixed within the image forming system 1. Therefore, the tube 25 maintains the connection between the recording head 20 and the ink tank 21 while deforming in response to the change in the relative position of the recording head 20 with respect to the ink tank 21 as the carriage 31 moves.

[0027] The belt mechanism 33 is arranged along the main scanning direction. The belt mechanism 33 comprises a drive pulley 331, a driven pulley 333, and an endless belt 335. The belt mechanism 33 moves the carriage 31 in the main scanning direction by using a shaft 35 and a guide rail 37 that restrict the movement of the carriage 31, and by converting the rotational motion of the CR motor 39 into the translational motion of the carriage 31.

[0028] An endless belt 335 is provided in the main scanning direction and is wound between a drive pulley 331 and a driven pulley 333. A shaft 35 and a guide rail 37 are arranged in parallel in the main scanning direction to form a travel path for the carriage 31. The drive pulley 331 is provided on one end of the travel path in the main scanning direction. The driven pulley 333 is provided on the other end of the travel path in the main scanning direction.

[0029] A CR motor 39 is connected to the drive pulley 331. The CR motor 39 is, for example, a DC motor. The drive pulley 331 rotates in conjunction with the rotation of the CR motor 39. The endless belt 335 and the driven pulley 333 rotate in conjunction with the rotation of the drive pulley 331.

[0030] The carriage 31 is fixed to the endless belt 335 and moves in translation in conjunction with the rotation of the endless belt 335. In other words, the carriage 31 moves in translation by receiving power from the CR motor 39 through the endless belt 335.

[0031] The carriage 31 is connected to a shaft 35 and a guide rail 37 that extend in the main scanning direction. The shaft 35 and the guide rail 37 are spaced apart on a plane parallel to the platen 10, in the sub-scanning direction perpendicular to the main scanning direction. That is, the shaft 35 and the guide rail 37 are positioned to support both sides of the carriage 31 in the sub-scanning direction.

[0032] The shaft 35 is positioned to pass through the carriage 31 and restricts the movement of the carriage 31 to the main scanning direction. This allows the carriage 31 to reciprocate along the shaft 35 in the main scanning direction. The guide rail 37 contacts the carriage 31 on the opposite side of the shaft 35 from the sub-scanning direction and restricts the movement of the carriage 31 to the main scanning direction. The carriage 31 is rotatably mounted on the guide rail 37, with rollers 311 running along the guide rail 37.

[0033] When the carriage 31 moves in translation in conjunction with the rotation of the endless belt 335, the roller 311 travels along the guide rail 37 by rolling motion while in contact with the guide rail 37. The carriage 31 moves in a straight line in the main scanning direction under the force acting from the endless belt 335, with its movement restricted by the shaft 35 and the guide rail 37.

[0034] The carriage 31 moves in the positive or negative direction of the main scanning direction, depending on the rotation direction of the endless belt 335. That is, the carriage 31 reciprocates in the main scanning direction in accordance with the switching of the rotation direction of the endless belt 335.

[0035] The linear encoder 40 is equipped with an optical sensor 41 and an encoder scale 45 and functions as an incremental optical linear encoder. The linear encoder 40 is used to observe the position and moving speed (hereinafter simply referred to as "speed") of the carriage 31 in the main scanning direction.

[0036] As shown in the figure, the encoder scale 45 is positioned along the travel path of the carriage 31 in the main scanning direction. The encoder scale 45 has markings arranged at predetermined intervals in the longitudinal direction corresponding to the main scanning direction.

[0037] The optical sensor 41 is fixed to the carriage 31 and moves with the carriage 31 in the main scanning direction. That is, the optical sensor 41 moves relative to the encoder scale 45. When the carriage 31 moves in the main scanning direction, the optical sensor 41 reads the scale of the encoder scale 45 and outputs an encoder signal corresponding to the change in the position of the carriage 31 in the main scanning direction.

[0038] Specifically, the optical sensor 41 outputs a pulse signal as an encoder signal each time the carriage 31 moves a predetermined amount in the main scanning direction. The encoder signal includes, for example, an A-phase signal and a B-phase signal that are 90 degrees apart in phase.

[0039] Based on the position and speed of the carriage 31 in the main scanning direction, which are detected based on this encoder signal, the controller 50 controls the movement of the carriage 31 and the ink ejection operation of the recording head 20.

[0040] As shown in Figure 2, the image forming system 1 includes a signal processing circuit 60, a motor driver 70, a head drive circuit 80, a user interface 90, and a communication interface 95 around the controller 50.

[0041] The signal processing circuit 60 is configured to detect the position and velocity of the carriage 31 in the main scanning direction based on the encoder signal input from the linear encoder 40. Hereinafter, the position and velocity V of the carriage 31 detected by the signal processing circuit 60 will also be referred to as the detected position and detected velocity V.

[0042] The motor driver 70 is configured to drive the CR motor 39 by applying the corresponding drive power to the CR motor 39 based on the voltage command value U input from the controller 50. The head drive circuit 80 is configured to drive the recording head 20 based on the command signal from the controller 50 and cause the recording head 20 to perform an ink ejection operation.

[0043] The user interface 90 includes an operation unit (not shown) for receiving operations from the user, and a display unit (not shown) for displaying various information to the user. The operation unit may be, for example, a touch panel provided on the display screen of the display unit. The display unit may be, for example, a liquid crystal display.

[0044] The communication interface 95 is configured to communicate with an external device. The image forming system 1 is configured to acquire image data from an external source via the communication interface 95 and to form an image on the object P based on the acquired image data.

[0045] As shown in Figure 2, the controller 50 comprises a main control unit 51, a motor control unit 53, and a head control unit 55. The motor control unit 53 is configured to control the position and speed of the carriage 31 in the main scanning direction by controlling the CR motor 39.

[0046] For example, the motor control unit 53 performs motor control to move the carriage 31 at a constant speed at a target speed Vr in the main scanning direction when forming an image on the target object P. This motor control is performed to control the point where the ink lands on the target object P.

[0047] Specifically, the motor control unit 53 is configured to feedback control the speed of the carriage 31 to a target speed Vr based on the detected speed V of the carriage 31 obtained from the signal processing circuit 60. The feedback control may be, for example, PID control.

[0048] The motor control unit 53 is configured to control the movement of the carriage 31 by, for example, calculating a voltage command value U corresponding to the deviation E = Vr - V between the detected speed V of the carriage 31 and the target speed Vr, and inputting the voltage command value U to the motor driver 70. The voltage command value U corresponds to the manipulated amount U for the CR motor 39 to move the carriage 31 in the main scanning direction at the target speed Vr.

[0049] The motor driver 70 is configured to drive the CR motor 39 by applying a drive current (in other words, drive power) corresponding to the voltage command value U input from the motor control unit 53, for example, by PWM (Pulse Width Modulation) drive. As a result, the speed of the carriage 31 is controlled to the target speed Vr. The voltage command value U corresponds to the PWM value.

[0050] The head control unit 55 inputs a control signal to the head drive circuit 80 to control the ink ejection operation of the recording head 20, based on the detected position of the carriage 31 obtained through the signal processing circuit 60.

[0051] In addition, the main control unit 51 is configured to receive commands from the user input through the user interface 90, monitor the status of the image forming system 1, and, if necessary, display information explaining the status of the image forming system 1 to the user through the user interface 90.

[0052] A distinctive feature of this embodiment is that the main control unit 51 is configured to determine the remaining lifespan, which is the remaining time until the image forming system 1 fails. Furthermore, based on the remaining lifespan, the main control unit 51 is configured to provide the user with maintenance-related information, such as information prompting maintenance such as parts replacement and cleaning, through the user interface 90 before the image forming system 1 fails.

[0053] Prior to providing this information, the main control unit 51 is configured to identify the cause of the abnormality and, based on the results of that identification, provide the user with maintenance-related information, specifically information regarding the parts to be maintained.

[0054] The main control unit 51 is configured to record the maximum value of the carriage speed V or voltage command value U, which are observed quantities related to the movement control of the carriage 31, for each printing job, and to predict the timing at which the maximum value reaches a threshold based on the time change of the maximum value. The main control unit 51 is configured to determine the predicted timing as the lifespan of the image forming system 1, and to determine the time from the present to the predicted timing as the remaining lifespan.

[0055] The main control unit 51 is configured to identify the cause of an abnormality when the remaining lifespan falls below a set value, inform the user of the remaining lifespan through the user interface 90, and prompt maintenance of the part corresponding to the cause of the abnormality. The details of the processes related to this remaining lifespan determination and identification of the cause of the abnormality will be described below.

[0056] As shown in Figure 2, the main control unit 51 includes a processor 511 and a memory 513. The processor 511 performs various functions, including determining the remaining lifespan, by executing processing according to the computer program recorded in the memory 513. The memory 513 may include RAM and NVRAM.

[0057] The job-related processing (Figure 3), maintenance-related processing (Figure 4), and cause identification processing (Figure 5) performed by the main control unit 51, as described below, can be understood as processes performed by the processor 511 in accordance with the computer program stored in memory 513.

[0058] When the start conditions for a print job are met, the main control unit 51 executes the job-related processing shown in Figure 3. For example, when a print job execution command is input through the user interface 90, the main control unit 51 executes the job-related processing.

[0059] When job-related processing is initiated, the main control unit 51 starts the print job (S110). In the print job, the main control unit 51, in cooperation with the motor control unit 53 and the head control unit 55, controls the movement of the carriage 31 and the ink ejection operation of the recording head 20 to form an image on the target object P based on the specified image data.

[0060] In a printing job, the motor control unit 53 controls the CR motor 39 to reciprocate the carriage 31 in the main scanning direction. The motor control unit 53 calculates a voltage command value U so that the carriage 31 moves at a constant speed at a target speed Vr in the region of the carriage 31's movement path where ink ejection occurs, which is located between the acceleration region and the deceleration region.

[0061] Specifically, the motor control unit 53 sequentially calculates a voltage command value U corresponding to the deviation E = Vr - V between the target speed Vr of the carriage 31 and the detected speed V of the carriage 31. The motor control unit 53 sequentially inputs the calculated voltage command value U to the motor driver 70, causing the motor driver 70 to drive the CR motor 39 based on the voltage command value U. This enables movement control of the carriage 31, and the speed of the carriage 31 is controlled to the target speed Vr.

[0062] The main control unit 51 generates observation data (S120) by sequentially recording the carriage speed V detected by the linear encoder 40 and / or the voltage command value U, which is the manipulated variable U input to the motor driver 70, in the memory 513 during the constant speed period, which is the period during which the carriage speed 31 is controlled to the target speed Vr.

[0063] The observational data consists of the observed velocity V and / or voltage command value U of the carriage 31, arranged in a time series. This observational data can contain information that allows for the identification of the position of the carriage 31 in the main scanning direction at the time each velocity V and / or voltage command value U was observed.

[0064] When the print job is completed (Yes in S130), the main control unit 51 identifies the peak of the speed V or voltage command value U during the constant-speed period indicated by the observation data as the index value Z used for determining the remaining lifespan (S140). The index value Z corresponds to the health indicator of the image forming system 1.

[0065] In S140, the main control unit 51 can identify the maximum value of the speed V during the constant-speed period in the print job as the index value Z. Alternatively, the main control unit 51 can identify the maximum value of the voltage command value U during the constant-speed period as the index value Z.

[0066] The main control unit 51 further analyzes the velocity V or voltage command value U during the constant-speed period indicated by the observation data and identifies the peaks of velocity V or voltage command value U for each of the multiple areas in the carriage 31's movement path (S150). The peaks of velocity V or voltage command value U identified here will be referred to as peak observation value Y below.

[0067] The designer of the image forming system 1 can arbitrarily determine whether to use velocity V or voltage command value U as the peak observed value Y. If velocity V is applied as the index value Z, velocity V can be applied to the peak observed value Y. If voltage command value U is applied as the index value Z, voltage command value U can be applied to the peak observed value Y.

[0068] Each of the above-mentioned areas corresponds to a portion of the movement path R0 within the carriage 31, when the movement path is viewed as a one-dimensional space parallel to the main scanning direction (see Figure 7A). The multiple areas may be defined to be continuously aligned in the main scanning direction, or to be defined to be discretely aligned. Multiple areas R0 within the movement path where abnormal peaks in velocity V or voltage command value U may occur are defined as multiple areas.

[0069] In a print job, the carriage 31 repeatedly reciprocates in the main scanning direction. In S150, the main control unit 51 can identify the maximum value of the speed V observed in the print job for each area as the peak observed value Y. Alternatively, the main control unit 51 can identify the maximum value of the voltage command value U observed in the print job for each area as the peak observed value Y.

[0070] In the subsequent S160, the main control unit 51 records the index value Z and the peak observed value Y for each area in a recording table. After that, the main control unit 51 terminates the job-related processing.

[0071] The main control unit 51, for each print job execution, adds the index value Z and the peak observed value Y for each area to the table in S160, thereby storing time-series data of the index value Z and time-series data of the peak observed value Y for each area in the table. The table also records the date and time of recording along with the index value Z and the peak observed value Y for each area.

[0072] Each time the main control unit 51 executes a job-related process, it executes the maintenance-related process shown in Figure 4 following the job-related process. In the maintenance-related process, the remaining lifespan of the image forming system 1 is determined based on the trend of the index value Z shown in the table (S250), and if the remaining lifespan is short, the user is notified of the remaining lifespan and the need for maintenance (S290).

[0073] When maintenance-related processing is initiated, the main control unit 51 determines whether a predetermined number of records or more have been accumulated in the table (S210). The records referred to here are records with index value Z. If job-related processing is executed a predetermined number of times or more, and as a result a predetermined number or more of index value Z are accumulated in the table, the main control unit 51 makes a positive determination in S210 and executes the process in S220. If the number of index value Z is less than the predetermined number (No in S210), the main control unit 51 considers there is insufficient information and terminates the maintenance-related processing.

[0074] In S220, the main control unit 51 determines whether the change in the index value is above a certain threshold. Specifically, the main control unit 51 determines whether the latest value of the index value Z has decreased by a certain threshold compared to the previous value. If the main control unit 51 determines that it has decreased by a certain threshold (Yes in S220), it executes the process in S300. The index value Z improves rapidly due to the maintenance. The determination in S220 is made to detect the improvement in the index value Z due to the maintenance.

[0075] If the main control unit 51 determines in S220 that the change in the index value is below the standard (No in S220), it executes the process in S230. In S230, the main control unit 51 generates smoothed time series data of the index value Z by performing a smoothing process on the time series data of the index value Z registered in the table. Specifically, the smoothing process may be a moving average process. The moving average process smooths the time series data of the index value Z in the time direction.

[0076] Subsequently, the main control unit 51 calculates an approximate curve of the index value Z by function fitting using a predetermined function to the time series data of the smoothed index value Z (S240). The graph shown in Figure 6 is a graph plotting the index value Z for each print job based on the time series data of the smoothed index value Z, and has time T on the horizontal axis and the index value Z on the vertical axis.

[0077] In the graph, time T can be understood as the number of times the print job has been executed. In Figure 6, the white dots correspond to the plotted points of the index value Z. When each index value Z corresponds to the maximum value of speed V in each print job, the group of plotted points represents the time progression of the maximum value of speed V.

[0078] Figure 6 illustrates an example in which an exponential function approximation curve corresponding to a group of plotted points is calculated using function fitting with an exponential function. In Figure 6, the approximation curve is represented by a solid line. Function fitting is performed, for example, to search for an approximation curve that minimizes the sum of squared errors with respect to the errors from the plotted points.

[0079] In the subsequent S250, the main control unit 51 determines the remaining time until point TD, when the index value Z in the approximation curve reaches the threshold Z_TH, as the remaining lifespan. That is, the time from the present to a future point TD (for example, the number of print job executions) is determined as the remaining lifespan.

[0080] For example, the time from the latest plotted point (the plotted point located at the end of the time axis) to time TD in Figure 6 corresponds to the remaining lifetime. The threshold Z_TH corresponds to the value at which the image forming system 1 is considered to have failed when the index value Z exceeds the threshold Z_TH. The threshold Z_TH is set in advance through operational tests of the image forming system 1, etc.

[0081] When the index value Z corresponds to the maximum speed V of the carriage 31 in the print job, the threshold Z_TH may correspond to the maximum speed V at which normal speed control is possible. When the index value Z corresponds to the maximum voltage command value U in the print job, the threshold Z_TH may correspond to the voltage command value at which the maximum drive current that can be applied to the CR motor 39 is possible.

[0082] For example, if dirt adheres to the encoder scale 45 and the optical sensor 41 cannot read the scale correctly, a deviation of the speed V from the target speed Vr is likely to occur, and as the dirt progresses, the index value Z corresponding to the maximum value of speed V may reach the threshold Z_TH. For example, if the reaction force acting on the carriage 31 increases due to a malfunction of the carriage movement mechanism 30 due to mechanical wear, the index value Z corresponding to the maximum value of the voltage command value U may reach the threshold Z_TH.

[0083] In the following S260, the main control unit 51 determines whether the remaining lifespan is less than a set value. The set value is determined so that information prompting maintenance can be output at an appropriate time before the image forming system 1 reaches the end of its lifespan.

[0084] If the main control unit 51 determines that the remaining lifespan is less than the set value (Yes in S260), it sets an abnormality flag (S270). When the remaining lifespan is less than the set value, the observed quantities related to the movement control of the carriage 31, such as the carriage speed V or the voltage command value U, are deviating from normal values. The main control unit 51 detects an abnormality in the observed quantities related to the movement control of the carriage 31 by comparing the remaining lifespan with the set value in S260.

[0085] In the subsequent S280, the main control unit 51 identifies the area where an anomaly in the observed quantity was detected along the carriage 31's movement path, based on the time-series data of the peak observed value Y for each area recorded in the table by the processing in S150 (see Figure 3), and thereby identifies the cause of the anomaly. In this way, the main control unit 51 identifies the part of the image forming system 1 that has reached the end of its lifespan (S280).

[0086] Specifically, in S280, the main control unit 51 executes the cause identification process shown in Figure 5. When the cause identification process is started, the main control unit 51 refers to the peak observation value Y recorded in the table and determines whether a peak exceeding the threshold Y_TH has occurred in only one area out of multiple areas (S281). Here, the area where a peak exceeding the threshold Y_TH has occurred is identified as the area where an anomaly in the observed quantity has been detected.

[0087] The main control unit 51 can, for each of several areas, refer to the peak observed value Y observed in multiple print jobs executed in the past predetermined period, and determine for each area whether the peak observed value Y has exceeded the threshold Y_TH at any point in the past predetermined period. In another example, the main control unit 51 can refer to the latest peak observed value Y recorded in the table and determine whether the said peak observed value Y exceeds a predetermined threshold Y_TH.

[0088] The threshold Y_TH may be defined as a single threshold common to multiple areas, or it may be defined individually for each area. The threshold Y_TH may be set to a value smaller than the threshold Z_TH, based on the threshold Z_TH of the index value Z and the remaining lifespan. For example, the threshold Y_TH may be set within a range less than or equal to the index value Z when a positive judgment is made in S260.

[0089] If a large peak observation value Y exceeding the threshold Y_TH is observed in two or more areas, the main control unit 51 makes a negative determination in S281. If the decision in S281 is negative (No in S281), the main control unit 51 executes the process in S282.

[0090] For example, as shown in Figure 7A, if the peak observed value Y fluctuates significantly throughout the entire movement process of the carriage 31 (specifically, the constant speed control process), and the area where the peak observed value Y exceeds the threshold Y_TH extends to multiple areas, the main control unit 51 makes a negative judgment in S281.

[0091] Figures 7A and 7B are graphs showing the change in velocity V or voltage command value U during the movement of the carriage 31, with the horizontal axis representing the position of the carriage 31 and the vertical axis representing the velocity V or voltage command value U corresponding to the peak observed value Y.

[0092] In S282, the main control unit 51 identifies the cause of the abnormality as the first part. The first part is the part that generates the cause of the abnormality in speed V or voltage command value U occurring over a wide range in the main scanning direction of the carriage 31's movement path.

[0093] In this embodiment, the main control unit 51 identifies in S282 that the cause of the abnormality lies in the shaft 35. Thus, the main control unit 51 identifies the cause of the abnormality. In the image forming system 1, which forms an image by ejecting ink onto an object P, the accumulation of ink mist adhering to the shaft 35 causes the carriage speed V to increase.

[0094] Because the ink mist adheres to the entire shaft 35, the increase in velocity V is not limited to a single area but occurs in two or more areas. For this reason, in S282, the main control unit 51 identifies the cause of the abnormality as being in the shaft 35. After identifying the cause of the abnormality in S282, the main control unit 51 terminates the cause identification process.

[0095] If the peak observed value Y, which exceeds the threshold Y_TH, is observed in only one area, the main control unit 51 makes a positive determination in S281. If the positive determination is made in S281 (Yes in S281), the main control unit 51 executes the process in S283.

[0096] For example, as shown in Figure 7B, if, during the movement of the carriage 31, the velocity V or voltage command value U changes significantly in a single area and a peak observed value Y exceeding the threshold Y_TH is observed, the main control unit 51 makes a positive determination in S281 and executes the process in S283.

[0097] In S283, the main control unit 51 calculates the slope of the peak observed value Y in a single area (hereinafter referred to as the "abnormal area") where a peak exceeding the threshold Y_TH occurs. For example, the main control unit 51 can obtain the peak observed value Y of the abnormal area in multiple print jobs executed in a predetermined past period ending with the present, as time-series data of the most recent peak observed value Y from a table.

[0098] The main control unit 51 can calculate the slope as the average or maximum value of the rate of change per unit time of the peak observed value Y over a predetermined period in the past, based on the acquired time-series data. The rate of change per unit time may be the difference in the peak observed value Y between print jobs. That is, the rate of change per unit time may be the difference between the peak observed value Y of the abnormal area observed in one print job and the peak observed value Y of the abnormal area observed in the print job immediately preceding it.

[0099] In the subsequent S285, the main control unit 51 determines whether the peak has changed sharply based on the calculated slope. The main control unit 51 can determine that the peak has changed sharply if the slope calculated in S283 is greater than or equal to the reference value, and that the peak has not changed sharply if the slope is less than the reference value.

[0100] In the example shown in Figure 8A, the peak observed value Y changes gradually. On the other hand, in the example shown in Figure 8B, the peak observed value Y changes sharply. The main control unit 51 can make an affirmative judgment in S285 when the peak observed value Y changes sharply (in other words, discontinuously), as shown in Figure 8B, for example, and a negative judgment in S285 when the peak observed value Y changes gradually (in other words, continuously), as shown in Figure 8A, for example.

[0101] If the main control unit 51 makes an affirmative judgment in S285 (Yes in S285), it identifies the cause of the abnormality as the second part (S286). The second part is the part that generates the cause of an abnormality in speed V or voltage command value U occurring suddenly rather than gradually.

[0102] According to this embodiment, in S286, the main control unit 51 identifies that the cause of the abnormality lies in the linear encoder 40. Thus, the main control unit 51 identifies the cause of the abnormality.

[0103] In the image forming system 1, which forms an image by ejecting ink onto an object P, if ink adheres to the encoder scale 45, the normal reading of the scale by the optical sensor 41 is hindered, and from a certain point in time, an abnormality in the speed V or voltage command value U, as illustrated in Figure 7B, is suddenly observed. Once this abnormality occurs due to ink contamination, as shown in Figure 8B, a peak observation value Y exceeding the threshold Y_TH is continuously observed in the area corresponding to the ink contamination, and the location of the peak does not shift. Basically, a peak observation value Y exceeding the threshold Y_TH is observed in a single area.

[0104] For these reasons, in S286, the main control unit 51 identifies the cause of the abnormality as being in the linear encoder 40. After identifying the cause of the abnormality in S286, the main control unit 51 terminates the cause identification process.

[0105] If the main control unit 51 determines in S285 that the cause of the abnormality is a third part (S287), then the third part is a part that generates the cause of an abnormality in speed V or voltage command value U that occurs gradually. The third part may be a part that generates the cause of an abnormality in speed V or voltage command value U that occurs only in one specific, non-random area along the movement path of the carriage 31.

[0106] According to this embodiment, the main control unit 51 identifies in S287 that the cause of the abnormality lies in the tube 25. Thus, the main control unit 51 identifies the cause of the abnormality.

[0107] In the image forming system 1, which forms an image by ejecting ink onto an object P, an abnormality in the velocity V or voltage command value U is observed in the area of ​​the carriage 31's movement path where the reaction force of the tube 25 acting on the carriage 31 is greatest, due to the accumulation of ink mist adhering to the tube 25. This abnormality is observed in a specific area uniquely determined by the mechanical configuration of the image forming system 1, as shown in Figure 7B, for example. This abnormality gradually appears due to a gradual change in the velocity V or voltage command value U.

[0108] For these reasons, in S287, the main control unit 51 identifies the cause of the abnormality as being in tube 25. Alternatively, if there are multiple parts that generate the cause of a gradual abnormality in speed V or voltage command value U, the main control unit 51 can identify the part corresponding to the abnormal area as the cause of the abnormality. After identifying the cause of the abnormality in S287, the main control unit 51 terminates the cause identification process.

[0109] The main control unit 51 executes the processes in S283-S287 to identify the cause of the anomaly based on the time change of the observed quantity observed through multiple movement controls until the anomaly of the observed quantity is detected. According to this embodiment, the time change of the observed quantity is evaluated by the slope. According to this embodiment, whether or not the time change of the observed quantity is steep is evaluated by whether or not the time change of the observed quantity is above a standard, and in particular whether or not the slope is above a standard value.

[0110] After completing the cause identification process (S280), the main control unit 51 executes the process in S290. In S290, the main control unit 51 displays the remaining lifespan determined in S250 to the user via the user interface 90, and also displays information via the user interface 90 prompting maintenance of the part corresponding to the cause of the abnormality identified in S280. After that, the maintenance-related processes shown in Figure 4 are completed.

[0111] By executing this maintenance-related process, the main control unit 51 prompts the user to perform maintenance at an appropriate time before each part of the image forming system 1 reaches the end of its lifespan and the image forming system 1 fails as a result.

[0112] In S290, the main control unit 51 can output an alert sound through the user interface 90, thereby strongly prompting the user to perform maintenance. The user interface 90 may be equipped with a speaker (not shown) for outputting the alert sound.

[0113] On the other hand, if the main control unit 51 determines in S220 that the change in the index value is above the standard (Yes in S220), or if it determines in S260 that the remaining life is above the set value (No in S260), it executes the process in S300. Alternatively, if the main control unit 51 makes a negative determination in S260, it may terminate the maintenance-related processing without executing the processes in S300 and S310. Or, the main control unit 51 may be configured to terminate the maintenance-related processing without executing the processes in S300 and S310 for a predetermined period after the abnormality flag is set.

[0114] In S300, the main control unit 51 determines whether the abnormality flag is set. The abnormality flag is reset in the initial state and is set in the process of S270. If the main control unit 51 determines that the abnormality flag is not set (No in S300), it terminates the maintenance-related processing.

[0115] On the other hand, if the main control unit 51 determines that an abnormality flag is set (Yes in S300), it considers the maintenance to be complete and resets the abnormality flag and the related data (S310). For example, it resets the table that stores the time-series data of the index value Z. After that, the main control unit 51 terminates the maintenance-related processing.

[0116] According to the image forming system 1 of this embodiment described above, the main control unit 51 generates time-series data of the carriage speed V or voltage command value U of the carriage 31 observed by the movement control of the carriage 31 during a corresponding period (particularly a constant speed period) as observation data for each print job execution. Furthermore, for each print job execution, the main control unit 51 identifies an index value Z related to an abnormality in the image forming system 1 and a peak observation value Y for each area based on the observation data.

[0117] The main control unit 51 further determines the remaining lifespan of the image forming system 1 based on the change in the index value Z across multiple print jobs. Specifically, the main control unit 51 calculates an approximation curve relating to the change in the index value Z, determines the future time point TD at which the index value Z reaches the threshold Z_TH in the approximation curve as the lifespan of the image forming system 1, and determines the remaining time until the future time point TD as the remaining lifespan.

[0118] According to this embodiment, by determining the remaining lifespan using the method described above, it is possible to predict with high accuracy when the image forming system 1 will fail before it actually fails, and to prompt the user to perform maintenance on the image forming system 1 before it fails. As a result, the user can perform maintenance on the image forming system 1 at an appropriate time before it fails, thereby reducing the occurrence and prolongation of downtime associated with the failure.

[0119] According to this embodiment, the main control unit 51 specifically identifies the maximum value (i.e., peak) of the detected speed V or voltage command value U of the carriage 31 during the constant speed period as an index value Z. This index value Z corresponds to the characteristic quantity of the corresponding period. The maximum value of the detected speed V corresponds to the carriage's movement speed at the point in the constant speed period when the carriage's movement speed deviates the most from the target speed Vr.

[0120] The main control unit 51 smooths the time-series data of the index value Z in the time direction by moving average processing. Using the smoothed index value Z, it calculates an approximate straight line and determines the remaining life. Therefore, according to this embodiment, the influence of minute fluctuations in the index value Z can be suppressed, the trend of the index value Z can be accurately grasped, and the remaining life can be determined with high accuracy.

[0121] According to this embodiment, the main control unit 51 is further configured to identify the cause of an anomaly in the image forming system 1 from the peak observed value Y for each area and its time change. Specifically, the main control unit 51 identifies the cause of the anomaly from among the power conversion system (shaft 35), linear encoder 40, and tube 25, which are candidates for the cause of the anomaly, according to the area where the anomaly in the observed quantity was detected and the time change. Therefore, according to this embodiment, the cause of an anomaly in the image forming system 1 can be identified accurately and appropriately without relying on frequency analysis.

[0122] When the remaining lifespan falls below a set value, the main control unit 51 identifies the cause of the abnormality using the method described above, based on the peak observed values ​​Y for each area accumulated up to that point. The main control unit 51 further displays information through the user interface 90 prompting the user to perform maintenance according to the cause of the abnormality.

[0123] Therefore, by performing maintenance according to the display from the image forming system 1, the user can appropriately eliminate the cause of failure before a failure is expected to occur in the future. As a result, the image forming system 1 can effectively suppress downtime caused by failures.

[0124] [Other embodiments] This disclosure is not limited to the embodiments described above, and various forms can be adopted. For example, in the first embodiment, the maximum value of the carriage 31's speed V during the constant speed period was identified as the index value Z, but instead of the maximum value, the difference δ (absolute value) from the target speed Vr of the maximum value may be identified as the index value Z.

[0125] In other words, the main control unit 51 can smooth the time-series data of the difference δ and perform function fitting on the smoothed time-series data of the difference δ. The point at which the approximate curve obtained by this function fitting reaches a threshold can be determined as the lifespan of the image forming system 1, and the remaining lifespan can be determined. In this way, the main control unit 51 can determine the lifespan or remaining lifespan of the image forming system 1 based on the time change of the observed quantity (velocity V) observed by multiple carriage movement control operations.

[0126] Similar to the index value Z, the peak observed value Y may be identified and recorded as the difference (absolute value) of the maximum velocity V in the corresponding area from the target velocity Vr.

[0127] In addition, in the above embodiment, the main control unit 51 may perform maintenance-related processing such that it executes the processing of S270-S290 not when the remaining life falls below a set value, but when the indicator value Z becomes equal to or greater than the warning value set to be less than the threshold Z_TH. For example, the processing of S260 may be replaced with processing to determine whether or not the indicator value Z is equal to or greater than the warning value.

[0128] Furthermore, some or all of the job-related processing and maintenance-related processing performed by the image forming system 1 may be performed by an external server device 100 instead of the image forming system 1. For this purpose, a computer program may be prepared and installed on the server device 100 to cause the processor 110 of the server device 100 to execute some or all of the job-related processing and maintenance-related processing.

[0129] The server device 100 shown in Figure 9 is connected to the image forming system 1 via a wide-area network for communication. The server device 100 includes a processor 110 and a memory 120. The processor 110 functions as an acquisition unit 111 and a related processing unit 113 by executing processing according to a computer program stored in the memory 120.

[0130] The acquisition unit 111 acquires observation data generated by the image forming system 1 in S120 for each print job execution from the image forming system 1 through communication with the image forming system 1. The related processing unit 113 executes the job-related processing S140, S150, and S160 shown in Figure 3, as well as the maintenance-related processing shown in Figure 4 and the cause identification processing shown in Figure 5. However, in S290, the related processing unit 113 transmits the information necessary for display to the image forming system 1, causing the user interface 90 of the image forming system 1 to display the corresponding information. The server device 100 may be configured so that the user can check the corresponding information from a browser.

[0131] In addition, in the above embodiment, an index value Z was identified for each print job, time-series data of the index value Z was generated, and the remaining lifespan was determined based on this time-series data. However, the index value Z may be generated at predetermined intervals, such as daily, rather than for each print job. That is, the main control unit 51 can identify, for predetermined intervals not limited to each print job, the peak of the carriage speed V or voltage command value U, or the carriage speed V at the point in the corresponding period when the carriage speed V deviates most from the target speed Vr, or the difference δ of the carriage speed V from the target speed Vr, as a feature quantity for the corresponding period. The main control unit 51 can determine the lifespan or remaining lifespan of the image forming system 1 based on the time changes of the above feature quantities over multiple periods.

[0132] Furthermore, in the above embodiment, the peak observed value Y was identified for each area based on the position of the carriage 31. However, the velocity V or voltage command value U is obtained as time-series data. Abnormal peaks in velocity V or voltage command value U caused by the linear encoder 40 or tube 25 are observed as peaks in velocity V or voltage command value U at specific time points on the time axis, with the start of movement control of the carriage 31 as the origin, when the carriage 31 moves in the main scanning direction. That is, in Figures 7A and 7B, even when the horizontal axis is the time axis, similar waveforms are observed with respect to velocity V or voltage command value U.

[0133] Therefore, the main control unit 51 may record peak observed values ​​Y for each time period corresponding to an area, rather than for each area (S150). The time period referred to here may be a time period on a time axis with the origin being the start time of the movement control of the carriage 31 from the first endpoint to the second endpoint in the carriage 31's movement path. When the movement between endpoints in the carriage 31's movement path is controlled according to a constant velocity profile, each time period corresponds to a specific area in the carriage 31's movement path. In this case, the main control unit 51 can identify the cause of the anomaly using the peak observed values ​​Y for each time period in the cause identification process (S280). That is, the main control unit 51 can identify the cause of the anomaly based on the time period in which the anomaly in the observed quantity was detected during the movement process of the carriage 31.

[0134] Furthermore, the peak observed value Y and / or index value Z may use parameters different from the velocity V or the voltage command value U as the manipulated variable described above. The voltage command value U corresponds to the motor torque and the acceleration of the carriage 31. Therefore, instead of velocity V, the acceleration calculated from velocity V may be used as the peak observed value Y and / or index value Z to identify the lifespan and / or cause of the malfunction. The acceleration is the time derivative of velocity V and is related to velocity V.

[0135] In the above embodiment, peaks in each area were identified due to the cause of the anomaly. However, the main control unit 51 may be configured to store a sample waveform in memory 513 for each cause of anomaly when the corresponding cause occurred, and to identify the cause of the anomaly by comparing the sample waveform for each cause with the observed waveform, which is the waveform of the observed position or time versus the peak observed value Y. In this case, the main control unit 51 can identify the cause of the anomaly based on the similarity between the observed waveform and the sample waveform for each cause of anomaly. Artificial intelligence (AI) can be used to determine the similarity.

[0136] In addition, the cause identification process may be performed regardless of the remaining lifespan, when an event occurs in which the peak observed value Y exceeds the threshold Y_TH, or when such an event occurs continuously for a predetermined period of time. The image forming system 1 of the above embodiment may be applied to inkjet printers other than garment printers.

[0137] In the above embodiment, as shown in Figure 5, the main control unit 51 identifies the area where the peak observed value Y exceeds the threshold Y_TH as the area where an anomaly in the observed quantity has been detected (S281). Based on this area where an anomaly in the observed quantity has been detected and the change in the peak observed value in that area, the main control unit 51 identifies the cause of the anomaly (S282-S287).

[0138] However, depending on the type of anomaly, anomalies in the observed values ​​may also be observed in related areas, as shown in Figure 10. Therefore, the main control unit 51 may identify the area where the peak observed value Y exceeds the threshold Y_TH, and related areas associated with this area, as areas where an anomaly in the observed quantity has been detected, and identify the cause of the anomaly.

[0139] The aforementioned related area can be predefined as an area where changes in the observed quantity (velocity V or voltage command value U) due to the same anomaly cause can be observed, even if the peak observed value Y does not exceed the threshold Y_TH.

[0140] While not limited to this, the relevant area may be defined as the area adjacent to the area where the peak observed value Y exceeds the threshold Y_TH. In this case, the main control unit 51 identifies a broad area including the area where the peak observed value Y exceeds the threshold Y_TH as the area where an anomaly in the observed quantity has been detected. The main control unit 51 can identify the cause of the anomaly based on the observed quantity (velocity V or voltage command value U) in the adjacent area adjacent to the area where the peak observed value Y exceeds the threshold Y_TH.

[0141] As shown in the example in Figure 10, among the multiple areas R1, R2, R3, and R4, a peak in the observed quantity exceeding the threshold Y_TH occurs in area R3. The waveforms shown in Figure 10 show the change in the observed quantity with respect to position (or time). The dashed line waveform shows the waveform before the anomaly was detected, and the solid line waveform shows the waveform after the anomaly was detected. In Figure 10, the change from the dashed line waveform to the solid line waveform should be understood as being caused by an anomaly in the image forming system 1.

[0142] As can be seen from the waveform changes, in the example shown in Figure 10, changes in the observed quantity are also observed in area R2, which is adjacent to area R3. When the peak observed value Y in area R3 exceeds the threshold Y_TH, the main control unit 51 identifies the wide area R2, R3 (or areas R2, R3, R4), which includes area R3 and its adjacent area R2 (or adjacent areas R2, R4), as the area where an anomaly in the observed quantity was detected, and can identify the cause of the anomaly based on the changes in the observed quantity in adjacent area R2 (or adjacent areas R2, R4).

[0143] The function of one component in the above embodiment may be distributed among multiple components. The functions of multiple components may be integrated into one component. Some parts of the configuration of the above embodiment may be omitted. At least some parts of the configuration of the above embodiment may be added to or replaced by the configuration of other above embodiments. Any aspect of the technical concept specified by the wording of the claims constitutes an embodiment of the present disclosure.

[0144] [Technical Concept Disclosed in This Specified Specification] This specification can be understood to disclose the following technical concepts: [Item 1] An image forming system, A recording head configured to eject ink onto a recording medium, A carriage movement mechanism comprising: a carriage on which the recording head is mounted; a motor; and a power conversion system that moves the carriage in the main scanning direction by converting the rotational motion of the motor into translational motion of the carriage; A motor driver configured to drive the motor, An encoder configured to output an encoder signal corresponding to the change in position in the main scanning direction of the carriage, A controller configured to control the movement of the carriage by inputting an operation amount to the motor driver to move the carriage at a target speed in the main scanning direction, based on the carriage's movement speed detected from the encoder signal, Equipped with, The motor driver is configured to drive the motor by applying drive power based on the manipulated amount to the motor. The controller is configured to detect an anomaly in the movement speed, a physical quantity related to the movement speed, or the manipulated quantity as observed quantities observed by the movement control of the carriage, and to identify the cause of the anomaly based on the area in the carriage's movement path where the anomaly in the observed quantity is detected or the time period in the carriage's movement process where the anomaly in the observed quantity is detected. [Item 2] The image forming system described in item 1, The controller is configured to identify the cause of the anomaly based on the area or time period in which the anomaly in the observed quantity was detected, as well as the time change of the observed quantity observed through multiple movement controls up to the time the anomaly in the observed quantity was detected. [Item 3] The image forming system described in item 2, The controller is configured to identify the cause of the anomaly based on whether the time change of the observed quantity is above a certain threshold. [Item 4] An image forming system according to any one of items 1 to 3, The controller is configured to determine the lifespan or remaining lifespan of the image forming system based on the time change of the observed quantity observed through multiple movement controls, and to identify the cause of the abnormality on the condition that the remaining time until the lifespan or the remaining lifespan is less than a threshold. [Item 5] The image forming system described in item 4, The controller is configured to, for each of a plurality of periods, identify the peak of the manipulated amount in the corresponding period, or the carriage's movement speed at the point in the corresponding period when the carriage's movement speed deviates most from the target speed, or the difference between the carriage's movement speed and the target speed, as a feature quantity for the corresponding period, and to determine the lifespan or remaining lifespan of the image forming system based on the time change of the feature quantity over the plurality of periods. [Item 6] An image forming system according to any one of items 1 to 5, The controller is configured to detect a peak in the manipulated variable, a peak in the movement speed, or a peak in the difference of the movement speed from the target speed that is greater than or equal to a standard as an anomaly in the observed variable, and to identify an area in the carriage's movement path where a peak greater than or equal to the standard is observed as an area where an anomaly in the observed variable has been detected. [Item 7] The image forming system described in item 2, The aforementioned recording head is connected to the ink tank via a tube. The candidates for the cause include the tube, the encoder, and the power conversion system. The controller is configured to identify the cause of the abnormality from among the candidates, according to the area and the time change. [Item 8] A method for identifying the cause of an anomaly in an image forming system, The aforementioned image forming system is A recording head configured to eject ink onto a recording medium, A carriage movement mechanism comprising: a carriage on which the recording head is mounted; a motor; and a power conversion system that moves the carriage in the main scanning direction by converting the rotational motion of the motor into translational motion of the carriage; A motor driver configured to drive the motor, An encoder configured to output an encoder signal corresponding to the change in position in the main scanning direction of the carriage, A controller configured to control the movement of the carriage by inputting an operation amount to the motor driver to move the carriage at a target speed in the main scanning direction, based on the carriage's movement speed detected from the encoder signal, Equipped with, The motor driver is configured to drive the motor by applying drive power based on the manipulated amount to the motor. The identification method involves detecting an anomaly in the observed quantity based on the observed quantity, the moving speed, a physical quantity related to the moving speed, or the manipulated quantity, as observed quantities observed by the movement control of the carriage. Based on the area where the abnormality in the observed quantity was detected along the carriage's movement path or the time period during which the abnormality in the observed quantity was detected during the carriage's movement process, the cause of the abnormality is identified. A specific method including [Item 9] The identification method described in item 8, Identifying the cause of the anomaly includes identifying the cause of the anomaly based on the time change of the observed quantity observed by multiple movement controls up to the time the anomaly of the observed quantity was detected, in addition to the area or time period in which the anomaly of the observed quantity was detected. [Item 10] The identification method described in item 9, Identifying the cause of the anomaly includes a method for identifying the cause of the anomaly based on whether or not the time change of the observed quantity is above a certain standard. [Item 11] A computer program that causes a computer to perform one of the specific methods described in any one of items 8 through 10. [Item 12] A computer-readable recording medium for storing the computer program described in item 11. [Explanation of Symbols]

[0145] 1…Image forming system, 20…Recording head, 21…Ink tank, 25…Ink supply tube, 30…Carriage movement mechanism, 31…Carriage, 311…Roller, 33…Belt mechanism, 35…Shaft, 37…Guide rail, 39…CR motor, 40…Linear encoder, 50…Controller, 51…Main control unit, 511…Processor, 513…Memory, 53…Motor control unit, 60…Signal processing circuit, 70…Motor driver, 90…User interface, 95…Communication interface, 100…Server device, 110…Processor, 111…Acquisition unit, 113…Related processing unit, 120…Memory.

Claims

1. An image forming system, A recording head configured to eject ink onto a recording medium, A carriage movement mechanism comprising: a carriage on which the recording head is mounted; a motor; and a power conversion system that moves the carriage in the main scanning direction by converting the rotational motion of the motor into translational motion of the carriage; A motor driver configured to drive the motor, An encoder configured to output an encoder signal corresponding to the change in position in the main scanning direction of the carriage, A controller configured to control the movement of the carriage by inputting an operation amount to the motor driver to move the carriage at a target speed in the main scanning direction, based on the carriage's movement speed detected from the encoder signal, Equipped with, The motor driver is configured to drive the motor by applying drive power based on the manipulated amount to the motor. The controller is configured to detect an anomaly in the movement speed, a physical quantity related to the movement speed, or the manipulated quantity as observed quantities observed by the movement control of the carriage, and to identify the cause of the anomaly based on the area in the carriage's movement path where the anomaly in the observed quantity is detected or the time period in the carriage's movement process where the anomaly in the observed quantity is detected.

2. The image forming system according to claim 1, The controller is configured to identify the cause of the anomaly based on the area or time period in which the anomaly in the observed quantity was detected, as well as the time change of the observed quantity observed through multiple movement controls up to the time the anomaly in the observed quantity was detected.

3. The image forming system according to claim 2, The controller is configured to identify the cause of the anomaly based on whether the time change of the observed quantity is above a certain threshold.

4. The image forming system according to claim 1, The controller is configured to determine the lifespan or remaining lifespan of the image forming system based on the time change of the observed quantity observed through multiple movement controls, and to identify the cause of the abnormality on the condition that the remaining time until the lifespan or the remaining lifespan is less than a threshold.

5. The image forming system according to claim 4, The controller is configured to, for each of a plurality of periods, identify the peak of the manipulated amount in the corresponding period, or the carriage's movement speed at the point in the corresponding period when the carriage's movement speed deviates most from the target speed, or the difference between the carriage's movement speed and the target speed, as a feature quantity for the corresponding period, and to determine the lifespan or remaining lifespan of the image forming system based on the time change of the feature quantity over the plurality of periods.

6. An image forming system according to any one of claims 1 to 5, The controller is configured to detect a peak in the manipulated variable, a peak in the movement speed, or a peak in the difference of the movement speed from the target speed that is greater than or equal to a standard as an anomaly in the observed variable, and to identify an area in the carriage's movement path where a peak greater than or equal to the standard is observed as an area where an anomaly in the observed variable has been detected.

7. The image forming system according to claim 2, The aforementioned recording head is connected to the ink tank via a tube. The candidates for the cause include the tube, the encoder, and the power conversion system. The controller is configured to identify the cause of the abnormality from among the candidates, according to the area and the time change.

8. A method for identifying the cause of an anomaly in an image forming system, The aforementioned image forming system is A recording head configured to eject ink onto a recording medium, A carriage movement mechanism comprising: a carriage on which the recording head is mounted; a motor; and a power conversion system that moves the carriage in the main scanning direction by converting the rotational motion of the motor into translational motion of the carriage; A motor driver configured to drive the motor, An encoder configured to output an encoder signal corresponding to the change in position in the main scanning direction of the carriage, A controller configured to control the movement of the carriage by inputting an operation amount to the motor driver to move the carriage at a target speed in the main scanning direction, based on the carriage's movement speed detected from the encoder signal, Equipped with, The motor driver is configured to drive the motor by applying drive power based on the manipulated amount to the motor. The identification method involves detecting an anomaly in the observed quantity based on the observed quantity, the moving speed, a physical quantity related to the moving speed, or the manipulated quantity, as observed quantities observed by the movement control of the carriage. Based on the area where the abnormality in the observed quantity was detected along the carriage's movement path or the time period during which the abnormality in the observed quantity was detected during the carriage's movement process, the cause of the abnormality is identified. A specific method including

9. A method for specifying according to claim 8, Identifying the cause of the anomaly includes identifying the cause of the anomaly based on the time change of the observed quantity observed by multiple movement controls up to the time the anomaly of the observed quantity was detected, in addition to the area or time period in which the anomaly of the observed quantity was detected.

10. A method of identification according to claim 9, Identifying the cause of the anomaly includes a method for identifying the cause of the anomaly based on whether or not the time change of the observed quantity is above a certain standard.

11. A computer program for causing a computer to perform the identification method described in any one of claims 8 to 10.

12. A computer-readable recording medium for recording the computer program described in claim 11.

Images