Inkjet recording apparatus and method for diagnosing abnormalities in inkjet recording apparatus

Abstract

The present invention provides an inkjet recording device and an inkjet recording method that are capable of not only quickly detecting at least leakage of ink to the outside but also detecting whether ink control mechanism parts related to ink circulation are operating normally.　A control unit 20 executes a printing mode for executing printing on a printing target and a standby mode for avoiding printing on the printing target. The standby mode includes an ink circulation processing sequence for driving ink control mechanism parts 117, 207 to supply ink from an ink container 201 to an ink path for recollection, and a standby processing sequence for avoiding driving the ink control mechanism parts. The control unit is characterized by: determining that there is an abnormal state, where the ink control mechanism parts are not operating normally, if no increase is detected in the liquid level by a liquid level sensor 204 in the ink circulation processing sequence; determining that there is an abnormal state, where ink leakage has occurred in the ink path, if a decrease is detected in the liquid level by the liquid level sensor in the standby processing sequence; and issuing an alarm to a notification means 105 if the control unit determines that there is an abnormal state.

Description

[Technical Field]

[0001] The present invention relates to an inkjet recording apparatus and a method for diagnosing abnormalities in an inkjet recording apparatus, and more particularly to a continuous-jet charge-controlled inkjet recording apparatus and a method for diagnosing abnormalities in an inkjet recording apparatus. [Background technology]

[0002] A typical continuous-jet, charge-controlled inkjet recording device has an ink container in the main body that stores ink, and the ink from that container is supplied to the print head by an ink supply pump. The ink supplied to the print head is continuously ejected from the ink nozzles and turned into ink droplets. Of the ink droplets used for printing, those that are charged and deflected are then propelled to the desired printing position on the print target to form characters and symbols. Ink droplets that are not used for printing are not charged or deflected, but are collected in a gutter and returned to the ink container by an ink recovery pump.

[0003] In such inkjet recording devices, ink or solvent leaks (leaks) may occur from the ink path, solvent path, liquid container, etc. for some reason. Since it is difficult to completely prevent this, it is necessary to detect these leaks (detect abnormalities) and issue an alarm. As a method for leak detection, for example, an abnormality detection device described in Japanese Patent Laid-Open No. 2015-189229 (Patent Document 1) is known.

[0004] The abnormality detection device described in Patent Document 1 comprises a liquid container for storing ink or solvent, a liquid level detection means provided in the liquid container for detecting the liquid level, a control unit, and a display unit, and is configured such that if the time period over which the liquid level detected by the liquid level detection means by the control unit changes is longer than the time period over which the liquid level changes under the set printing conditions, it is determined that a leak has occurred and an abnormality warning is displayed on the display unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-189229 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the leak detection in the abnormality detection device of Patent Document 1 has the problem that it takes time to confirm the change in the liquid level in the liquid container depending on the printing conditions and the liquid level detection method. In other words, leaks cannot be detected until a predetermined liquid level is reached, making it difficult to detect leaks quickly.

[0007] Furthermore, the leak detection in the abnormality detection device of Patent Document 1 focuses on ink or solvent leaks from the ink path, solvent path, container, etc. However, particularly in the ink circulation operation that circulates ink, if a solenoid valve provided in the ink path does not open at the timing when it should open, a "closed fault" occurs, and it is also necessary to detect the failure of ink or solvent to flow into the liquid container, but Patent Document 1 does not take this into consideration. The same is true for the reverse case. Note that this is not limited to solenoid valve faults, but also applies to pump stoppage faults, etc. These components will be described below as ink control mechanism parts related to the ink circulation operation.

[0008] An object of the present invention is to provide an inkjet recording device and an abnormality diagnosis method for an inkjet recording device that can not only quickly detect at least any ink leakage to the outside, but also detect whether ink control mechanism parts related to ink circulation operation are operating normally. [Means for solving the problem]

[0009] The present invention provides An inkjet recording device having a print head for printing, an ink container storing ink, a first ink path for supplying ink for printing from the ink container to the print head and recovering ink not used for printing into the ink container, a second ink path for supplying replenishment solvent and replenishment ink to the ink container, ink control mechanism parts provided midway through the first ink path and the second ink path, and a control unit for controlling the print head and the ink control mechanism parts, The ink container is provided with a liquid level sensor that continuously detects the liquid level of the ink stored in the ink container, The control unit has a print mode in which printing is performed on the printing object and a pause mode in which printing is not performed on the printing object as control modes, The pause mode is a mode in which the ink control mechanism components are driven to supply ink from the ink container to the first ink path and then collect the ink back into the ink container, and an ink circulation process sequence is executed in which the ink container is replenished with replenishment solvent and replenishment ink, and a standby process sequence is executed in which the ink control mechanism components are not driven. The control unit includes at least a diagnostic unit that determines, when the liquid level sensor does not detect an increase in the liquid level during the execution of the ink circulation process sequence, that an abnormal state is occurring in which the ink control mechanism components are not operating normally, and that, when the liquid level sensor detects a decrease in the liquid level during the execution of the standby process sequence, that an abnormal state is occurring in which ink is leaking from the ink container. 、 The diagnostic section of the control section executes abnormality diagnosis by a diagnostic program that is executed at predetermined time intervals. It is characterized by the following. [Effects of the Invention]

[0010] According to the present invention, not only can it be quickly detected whether ink is leaking to the outside, but it can also be detected whether ink control mechanism parts related to ink circulation are operating normally. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration of an inkjet recording apparatus. [Figure 2] FIG. 2 is a schematic diagram illustrating an ink piping system of the inkjet recording apparatus. [Figure 3] FIG. 10 is a schematic diagram illustrating an outline of a liquid level sensor disposed in the main ink container. [Figure 4] 4 is a characteristic diagram illustrating the relationship between the sensor depth and impedance of the detection electrode sensor shown in FIG. 3. FIG. [Figure 5] FIG. 10 is a flowchart illustrating control for detecting an abnormality in an ink piping system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment, and various modifications and application examples within the technical concept of the present invention are also included within its scope.

[0013] Before describing the embodiments of the present invention, a brief description will be given of the structure and operation of an ink jet printing apparatus to which the present invention is applied.

[0014] In FIG. 1, the inkjet recording device has a print head 10 that performs printing, an ink path (see FIG. 2 for details) consisting of piping that supplies ink for printing to the print head 10, collects ink that is not used for printing, and circulates the ink and solvent, an electromagnetic valve (not shown) provided midway along the ink path, a pump 117, and a control unit 20 that controls the print head 10.

[0015] First, we will explain the outline of the configuration of the printing and ink circulation section of print head 10. Ink pillar 110 ejected from nozzle 109 is atomized by the electrostrictive element of nozzle 109 to become ink droplets 113 based on the excitation voltage generated by excitation voltage generation circuit 108. Then, a voltage generated by charging voltage generation circuit 107 is applied to charging electrode 111, and the ink droplets are charged by a voltage corresponding to the character signal.

[0016] The charged ink particles 113 fly in the electric field created by the deflection electrode 112, are deflected according to the amount of charge, and reach the printing target 115 moving on the transport conveyor 116, where they form characters. Ink particles 113 not used for printing are collected by the ink collection gutter 114, and the collected ink is returned to the main ink container and supplied again to the nozzle 109 by the pump 117.

[0017] Next, we will explain the control unit 20. The control unit 20 has an MPU (microprocessing unit) 101 that controls the entire system, a ROM or flash memory 102 that stores control programs and data required for the MPU 101 to operate, and a RAM 103 that temporarily stores data required during program execution.

[0018] The MPU 101 can be connected to an external storage device 120 that stores programs, print data, etc., and a typical external storage device is a USB memory, etc. It can also be connected to an input panel 104 for inputting print content, setting values, etc., and a display device 105 for displaying the input data, print content, etc. A bus line 106 that transmits data signals, address signals, and control signals from the MPU 101 is used for these connections.

[0019] The control unit 20 also has an excitation voltage generating circuit 108 for generating a voltage to atomize the ink connected to the nozzles 109, and a charging voltage generating circuit 107 for generating a voltage to the ink droplets according to a character signal. Furthermore, the control unit 20 is provided with a rotary encoder 119, which generates a pulse signal according to the conveyor movement speed. Note that the rotary encoder is not built into the inkjet recording apparatus, but is installed on the conveyor.

[0020] The inkjet recording device also includes a sensor 122 that detects the object to be printed. The sensor 122 is often a photoelectric sensor, and generally uses a system that outputs a signal only while the object to be printed blocks light, thereby detecting that the object to be printed is approaching the inkjet recording device.

[0021] Next, the configuration of the ink piping system of the inkjet recording device will be described with reference to Fig. 2. Ink control mechanism components including a pump 117 and an electromagnetic valve 207 are arranged in this ink piping system. These components are well known and well-known.

[0022] The main components of the ink piping system include a main ink container 201, an ink refill container 202, a solvent refill container 203, and ink paths connected to these. The main ink container 201 and the ink refill container 202 are provided with liquid level sensors 204 that detect the liquid levels of ink etc. stored in the containers. The solvent refill container 203 may also be provided with a liquid level sensor 204 as needed.

[0023] In the present embodiment described below, an abnormality detection method using the liquid level sensor 204 provided in the main ink container 201 will be described.

[0024] Each pipe constituting the ink path is provided with a viscometer 205 for measuring the viscosity of the ink, pumps 117 for delivering or sucking the ink or solvent, solenoid valves 206 and 207 for circulating or sealing the ink or solvent, a nozzle 109 for spraying ink, and a gutter 114 for collecting the ink sprayed from the nozzle.

[0025] Next, the ink flow in such an ink jet recording apparatus when the pause processing mode is performed will be explained, while the explanation of the print processing mode will be omitted.

[0026] The pause processing mode executes an ink circulation processing sequence in which ink is circulated, and a standby processing sequence in which ink is not circulated. The ink circulation processing sequence is a process in which the pump and solenoid valves are driven to circulate ink through the piping system. The standby processing sequence is a process in which the pump and solenoid valves are not driven to prevent ink from circulating through the piping system. The ink circulation processing sequence and the standby processing sequence are configured to be executed alternately at predetermined time intervals.

[0027] Here, since the ink circulation processing sequence uses most of the piping and ink control mechanism parts, it is possible to estimate at least operational abnormalities of the ink control mechanism parts from the detection signal of the liquid level sensor 204. Of course, this estimation requires the use of a special diagnostic program, and this diagnostic program is a major feature of this embodiment.

[0028] Next, the ink flow in the ink circulation processing sequence will be described. During the ink circulation operation, ink is supplied from the main ink container 201 to each pipe by the operation of a pump and solenoid valve, and is also collected from each pipe back into the main ink container 201, where it is further replenished with ink and solvent. Therefore, by monitoring the liquid level in the main ink container 201, it is possible to indirectly detect abnormalities in the solenoid valve 207, pump 117, etc.

[0029] 2, the electromagnetic valve (for supply) 207A is energized to open the flow path, and the switching valve 206 is energized to connect the ink path to the nozzle 109. By operating the pump (for supply) 117A, the ink stored in the main ink container 201 is supplied to the nozzle 109 of the print head and is ejected from the nozzle 109 as ink droplets.

[0030] Furthermore, when solenoid valve (for recovery) 207B is energized to open the flow path and operate pump (for recovery) 117B, ink particles and air around the print head are sucked through gutter 114 and pressure-fed to main ink container 201. Note that because the ink and air flow in a gas-liquid mixture, the ink's solvent component dissolves in the air, and the air becomes solvent gas and flows into main ink container 201. The ink that flows into main ink container 201 is collected at the bottom of the container, and the air with the solvent dissolved in it is discharged to the outside of the main body as solvent gas.

[0031] Here, since the solvent component in the ink is discharged outside the device as solvent gas, if the operation time of the inkjet recording device is long, the ratio of the solvent component in the ink decreases, and the ink concentration may become high. Conversely, if the operation time is short, the ink concentration may become low due to solvent that has flowed into the ink container 201 during cleaning or other processes.

[0032] Therefore, in the ink path, the solenoid valve (for viscosity measurement) 207C is energized to open the flow path, and the pump (for circulation) 117C is operated to send the ink in the main ink container 201 to the viscosity measuring device 205, thereby measuring the viscosity of the ink (converted to concentration).

[0033] The detected viscosity value measured is input to the MPU 101. As a result, when the ink concentration is low, the MPU 101 energizes the solenoid valve (for refill) 207D to open the flow path, and energizes the switching valve 206 to connect the ink path to the nozzle 109. At this time, the solenoid valve (for supply) 207A is closed.

[0034] Then, by operating the pump (for supply) 117A, the ink stored in the ink refill container 202 is supplied to the nozzles 109 of the print head and ejected as ink droplets from the nozzles 109. The ejected ink droplets are captured in the gutter 114.

[0035] The refill ink captured in the gutter 114 is pumped toward the main ink container 201 by energizing the solenoid valve (for recovery) 207B to open the flow path and operate the pump (for recovery) 117B, thereby increasing the ink concentration.

[0036] On the other hand, if the ink concentration in the main ink container 201 is high, the electromagnetic valve (for solvent replenishment) 207E is energized to open the flow path, and the pump (for solvent supply) 117E is operated to replenish the solvent in the solvent replenishment container 203 to the main ink container 201. In this way, the inkjet recording apparatus executes control to replenish the ink and solvent so that the viscosity of the ink falls within the range of the control value.

[0037] Furthermore, while ink is being supplied from the main ink container 201 to the nozzles 109, the solenoid valve (for circulation) 207F is energized to open the flow path and the pump (for circulation) 117C is operated, thereby circulating the ink so that at least a portion of the ink supplied to the nozzles 109 is sucked into the pump (for circulation) 117C and returned to the main ink container 201. Furthermore, before the switching valve 206 is energized, the solenoid valves (for main body circulation) 207G and 207H are energized to open the flow path and the pump (for circulation) 117B and the pump (for solvent supply) 117E are operated, thereby circulating the ink and solvent.

[0038] In this way, the ink path is composed of a first ink path that supplies printing ink from the ink container to the print head and collects ink not used for printing back into the ink container, and a second ink path that supplies replenisher solvent and replenisher ink to the ink container. Note that, as mentioned above, the first ink path and the second ink path may be shared in some cases.

[0039] In the ink circulation processing sequence of the inkjet recording device, ink control mechanism parts are operated in most of the ink paths to circulate ink, preventing ink in the paths from drying out and causing solenoid valves and other components to stick. On the other hand, in the standby processing sequence, ink control mechanism parts are not operated so as not to circulate ink in the ink paths, thereby reducing power consumption. Note that this ink circulation processing sequence and standby processing sequence are executed every time a predetermined fixed time has elapsed.

[0040] Next, we will explain the liquid level sensor 204 used in the main ink container 201 used in this embodiment.This liquid level sensor 204 is of a type that outputs a continuous detection signal in response to changes in the ink liquid level.

[0041] The liquid level sensor 204 uses multiple (here, two) detection electrode bars (in the form of plate-like electrodes) with electrical resistance, and continuously detects changes in the liquid level based on the magnitude of their electrical impedance.

[0042] In Figure 3, the main ink container 201 is provided with a liquid level sensor 204. The liquid level sensor 204 is composed of two detection electrode bars 210 immersed in ink and a detection circuit 211 connected to the two detection electrode bars 210. The detection circuit 211 detects the impedance (Z) between the two detection electrode bars 210 immersed in ink, and can continuously estimate changes in the ink level based on changes in the impedance (Z). Note that the ink is conductive.

[0043] Fig. 4 shows the relationship between the depth (L) of the detection electrode bars 210 immersed in the ink in the main ink container 201, which indicates the ink liquid level, and the impedance (Z) between the two detection electrode bars 210. As can be seen from Fig. 4, the impedance (Z) decreases as the depth (L) of the detection electrode bars 210 increases, and conversely, the impedance (Z) increases as the depth (L) of the detection electrode bars 210 decreases.

[0044] The ink level in the main ink container 201 can be determined from this change in impedance (Z), and the detected ink level can be correlated with ink path leaks, abnormalities in ink control mechanism components, etc. Therefore, if a diagnostic program is created based on this, it will not only be possible to quickly detect ink leaks to the outside, but also to estimate whether the ink control mechanism components related to ink circulation are operating normally.

[0045] A specific diagnostic program will be described below. This diagnostic program is started in sleep mode and is also configured to be started at a predetermined time interval. The predetermined time interval can be determined by using a compare match interrupt from a timer in the MPU.

[0046] In addition, in the ink circulation processing sequence, the ink control mechanism components are driven and ink and solvent are replenished into the main ink container 201, and in the standby processing sequence, the driving of the ink control mechanism components is stopped and ink and solvent are not replenished into the main ink container 201.

[0047] 5 is started at a predetermined timing, and the following control steps are executed. Note that the following assumes a state in which ink is leaking from the main ink container 201, and a state in which an abnormality has occurred in the ink control mechanism components 117, 207, preventing ink and solvent from being supplied to the main ink container 201.

[0048] <Step S10> In step S10, it is determined whether the ink circulation process sequence or the standby process sequence is currently being executed, and the process for determining whether the abnormality is an ink leak or an abnormality in the ink control mechanism parts is selected based on this determination.

[0049] If it is determined that the ink circulation process sequence is being executed, the process proceeds to step S11, where a process for an abnormality in the ink control mechanism parts is executed, whereas if it is determined that the standby process sequence is being executed, the process proceeds to step S14, where a process for an ink leak is executed.

[0050] <Step S11> Since it is determined in step S10 that the ink circulation process sequence is in progress, in step S11, the impedance value (Znew) corresponding to the liquid level is measured from the liquid level sensor 204 and stored in a predetermined area of ​​the RAM 102 shown in Fig. 1. The RAM 102 also stores the impedance value (Zold) measured at the previous startup timing before the current startup timing.

[0051] This is to determine whether the direction of change in the impedance value (Z) between the previous startup timing and the current startup timing has changed due to the occurrence of an abnormality. Of course, instead of the previous startup timing, the impedance value (Z) measured at an earlier startup timing can be used, and three or more impedance values ​​(Z) may be stored. Once the impedance value (Z) has been stored, the process proceeds to the next step S12.

[0052] <Step S12> In step S12, the impedance value (Zold) measured at the previous startup timing is compared with the impedance value (Znew) measured at the current startup timing. In this comparison, an abnormal state can be determined based on the difference between the impedance values ​​(Z) at the previous startup timing and the current startup timing and the sign of the difference.

[0053] In this case, since the ink and solvent are being replenished during the ink circulation process sequence, if there is no ink leakage in the ink path and the solenoid valve 207 and pump 117 are operating normally, the ink liquid level in the main ink container 201 should be higher than the ink level at the previous startup timing.

[0054] Therefore, in step S12, if the impedance value (Znew) measured at this startup timing is smaller than the impedance value (Zold) measured at the previous startup timing (the liquid level has not dropped), it is determined that there is no ink leakage in the ink path, the solenoid valve 227 and pump 117 are operating normally, and ink and solvent are being supplied, and the process proceeds to a loop (return) and the same operations (steps S10 to S12) are repeated.

[0055] On the other hand, if the impedance value (Znew) measured at the current startup timing is greater than the impedance value (Zold) measured at the previous startup timing, it is determined that an abnormality has occurred in the solenoid valve 207 or the pump 117 and that ink or solvent is not being supplied to the main ink container 204, and the process proceeds to step S13.

[0056] <Step S13> In step S12, it is determined that an abnormality has occurred in the solenoid valve 207 or the pump 117 and that ink or solvent is not being supplied to the main ink container 204, so in step S13, an abnormal state is determined to have occurred and an alarm such as "Abnormality has occurred in ink control mechanism component" is displayed on the display device 105 shown in Fig. 1. The display device 105 is an alarm means and can issue an alarm not only by "display" but also by "audio" or "audio and display."

[0057] In addition, in the series of abnormality detections, it is not possible to identify the specific location of the abnormality, that is, to identify the ink control mechanism parts such as the solenoid valve 207 and the pump 117. Therefore, the operator can simply inspect and repair the ink control mechanism parts based on the alarm displayed on the display device 105.

[0058] <Step S14> Returning to step S10, if it is determined that the ink circulation process sequence is not being executed, the process proceeds to step S14, regarding it as a standby process sequence. The process from step S14 onwards is for executing processes related to ink leakage. Note that in standby process sequences other than the ink circulation process sequence, the ink circulation operation by the solenoid valve 207 and pump 117, and the ink and solvent replenishment operation are not performed.

[0059] In step S14, an impedance value (Znew) corresponding to the liquid level is measured from the liquid level sensor 204 and stored in a predetermined area of ​​the RAM 102 shown in Fig. 1. The RAM 102 also stores an impedance value (Zold) measured at the previous startup timing before the current startup timing.

[0060] This is to determine whether the direction of change in the impedance value (Z) between the previous startup timing and the current startup timing has changed due to the occurrence of an abnormality. Of course, it is also possible to use the impedance value (Z) measured at an earlier startup timing rather than the previous startup timing. Once the impedance value (Z) has been stored, the process proceeds to the next step S15.

[0061] <Step S15> In step S15, the impedance value (Zold) measured at the previous startup timing is compared with the impedance value (Znew) measured at the current startup timing. In this comparison, an abnormal state can be determined based on the difference between the impedance values ​​(Z) at the previous startup timing and the current startup timing and the sign of the difference.

[0062] In this case, in the standby processing sequence, the main ink container 201 is not replenished with ink or solvent, and the ink circulation operation is not performed, so the ink liquid level in the main ink container 201 should not fluctuate.

[0063] Therefore, in this step S15, if the impedance value (Znew) measured at the current startup timing does not change from the impedance value (Zold) measured at the previous startup timing, it is determined that there is no ink leakage in the main ink container 201, and the process proceeds to a loop (return) and the same operations (step S10, steps S14 to S15) are repeated.

[0064] On the other hand, if the impedance value (Znew) measured at the current startup timing is greater than the impedance value (Zold) measured at the previous startup timing, it is determined that ink is leaking from the main ink container 201, and the process proceeds to step S16. It is assumed that ink leakage occurs mainly at the connection between the main ink container 201 and the piping, and this leakage causes the liquid level in the main ink container 201 to drop.

[0065] <Step S16> In step S15, it is determined that ink is leaking from the main ink container 201, so in step S16, an abnormal condition is detected and an alarm such as "An abnormality has occurred in the ink piping system" is displayed on the display device 105 shown in FIG. 1.

[0066] In this case, when an abnormality is detected, the operator only needs to inspect and repair the main ink container 201 based on the alarm displayed on the display device 105.

[0067] In this way, in this embodiment, a liquid level sensor is used that outputs a continuous detection signal in response to changes in the liquid level, and abnormalities are detected from the detection value of this liquid level sensor at the previous startup timing and the detection value at the current startup timing, so abnormalities can be detected quickly in response to the startup cycle of the diagnostic program.

[0068] Furthermore, since abnormality determination is performed during the ink circulation process sequence in which most of the piping and ink control mechanism parts are used, it becomes possible to easily detect abnormalities in ink control mechanism parts such as solenoid valves and pumps.

[0069] As described above, in the present invention, the control unit executes a print mode in which printing is performed on a print object and a pause mode in which printing is not performed on a print object, and the pause mode executes an ink circulation process sequence in which ink control mechanism components are driven to supply ink from the ink container and collect it back into the ink container, and replenish the ink container with replenisher solvent and replenisher ink, and a standby process sequence in which the ink control mechanism components are not driven, The control unit is characterized by having a diagnostic unit that, if the liquid level sensor does not detect an increase in the liquid level during the execution of the ink circulation processing sequence, determines that an abnormal state has occurred, meaning that the ink control mechanism components are not operating normally, and that, if the liquid level sensor detects a decrease in the liquid level during the execution of the standby processing sequence, determines that an abnormal state has occurred, meaning that ink is leaking from the ink container.

[0070] This not only makes it possible to quickly detect ink leakage to the outside, but also to detect whether ink control mechanism parts related to ink circulation are operating normally.

[0071] The present invention is not limited to the above-described embodiments, but includes various modifications. The above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace other configurations with respect to the configuration of each embodiment. [Explanation of symbols]

[0072] 101...MPU, 102...ROM, 103...RAM, 105...display device, 109...nozzle, 111...charging electrode, 112...deflection electrode, 114...gutter, 117A to 117Cm 117E...pump, 201...main ink container, 202...ink refill container, 203...solvent refill container, 204...liquid level sensor, 206...switching valve, 207A to 207H...solenoid valve, 210...detection electrode bar, 211...detection circuit.

Claims

1. An inkjet recording apparatus comprising: a print head for printing; an ink container storing ink; a first ink path for supplying the ink for printing from the ink container to the print head and recovering the ink not used for printing back into the ink container; a second ink path for supplying replenisher solvent and replenisher ink to the ink container; ink control mechanism components provided midway along the first ink path and the second ink path; and a control unit for controlling the print head and the ink control mechanism components, a liquid level sensor is disposed in the ink container to continuously detect the liquid level of the ink stored in the ink container; the control unit has a print mode in which printing is performed on the print object and a pause mode in which printing is not performed on the print object as a control mode, the pause mode is a mode in which the ink control mechanism components are driven to supply the ink from the ink container to the first ink path and then collect the ink back into the ink container, and an ink circulation process sequence is executed in which the ink container is replenished with the replenisher solvent and the replenisher ink, and a standby process sequence is executed in which the ink control mechanism components are not driven; the control unit includes a diagnostic unit that, when the liquid level sensor does not detect an increase in the liquid level during execution of the ink circulation process sequence, determines that an abnormal state has occurred, meaning that the ink control mechanism components are not operating normally, and that, when the liquid level sensor detects a decrease in the liquid level during execution of the standby process sequence, determines that an abnormal state has occurred, meaning that ink is leaking from the ink container; The diagnostic unit of the control unit executes abnormality diagnosis by a diagnostic program that is executed at predetermined time intervals. An inkjet recording apparatus characterized by:

2. 2. The inkjet recording apparatus according to claim 1, The diagnostic section of the control section issues an alarm to a notification means when determining that an abnormal state has occurred. An inkjet recording apparatus characterized by:

3. In the inkjet recording device according to claim 1, The diagnostic program is started when the sleep mode is executed. An inkjet recording apparatus characterized by:

4. An inkjet recording device having a print head for printing, an ink container storing ink, a first ink path for supplying the ink for printing from the ink container to the print head and recovering the ink not used for printing back into the ink container, a second ink path for supplying replenishment solvent and replenishment ink to the ink container, ink control mechanism parts provided midway through the first ink path and the second ink path, and a control unit for controlling the print head and the ink control mechanism parts, a liquid level sensor is disposed in the ink container to continuously detect the liquid level of the ink stored in the ink container; the control unit has a print mode in which printing is performed on the print object and a pause mode in which printing is not performed on the print object as a control mode, the pause mode is a mode in which the ink control mechanism components are driven to supply the ink from the ink container to the first ink path and then collect the ink back into the ink container, and an ink circulation process sequence is executed in which the ink container is replenished with the replenisher solvent and the replenisher ink, and a standby process sequence is executed in which the ink control mechanism components are not driven; the control unit includes a diagnostic unit that, when the liquid level sensor does not detect an increase in the liquid level during execution of the ink circulation process sequence, determines that an abnormal state has occurred, meaning that the ink control mechanism components are not operating normally, and that, when the liquid level sensor detects a decrease in the liquid level during execution of the standby process sequence, determines that an abnormal state has occurred, meaning that ink is leaking from the ink container; the liquid level sensor comprises two detection electrode bars immersed in the ink container and a detection circuit, and the detection circuit detects the liquid level of the ink from an impedance value between the two detection electrode bars; the liquid level sensor has a characteristic that the impedance value decreases as the liquid level increases, the diagnostic unit of the control unit executes abnormality diagnosis by a diagnostic program that is executed at predetermined time intervals, When the impedance value of the liquid level sensor detected at the current startup timing by the execution of the diagnostic program during the execution of the ink circulation process sequence is greater than the impedance value detected at the previous startup timing, it is determined that the ink control mechanism component is not operating normally and is in an abnormal state, During the execution of the standby process sequence, if the impedance value of the liquid level sensor detected at the current startup timing by the execution of the diagnostic program is greater than the impedance value detected at the previous startup timing, it is determined that an abnormal state has occurred in which ink is leaking from the ink container. An inkjet recording apparatus characterized by:

5. A printing apparatus comprising: a print head for printing; an ink container storing ink; a liquid level sensor for continuously detecting the liquid level of the ink stored in the ink container; a first ink path for supplying the ink for printing from the ink container to the print head and recovering the ink not used for printing into the ink container; a second ink path for supplying replenishment solvent and replenishment ink to the ink container; ink control mechanism parts provided midway through the first ink path and the second ink path; and a control unit for controlling the print head and the ink control mechanism parts; the control unit has a print mode in which printing is performed on a print object and a pause mode in which printing is not performed on the print object as control modes, and the pause mode drives the ink control mechanism components to supply the ink from the ink container to the first ink path and recover it back into the ink container, and also executes an ink circulation process sequence in which the ink container is replenished with the replenisher solvent and the replenisher ink, and a standby process sequence in which the ink control mechanism components are not driven, The control unit If the ink level sensor does not detect an increase in the ink level during the execution of the ink circulation process sequence, the ink control mechanism component is determined to be in an abnormal state, i.e., the ink control mechanism component is not operating normally; When the liquid level sensor detects a drop in the liquid level during execution of the standby process sequence, the liquid level sensor determines that an abnormal state has occurred in which the ink is leaking from the ink container, and The liquid level sensor comprises two detection electrode bars immersed in the ink container and a detection circuit, and the detection circuit detects the liquid level of the ink from an impedance value between the two detection electrode bars, and the liquid level sensor has a characteristic that the impedance value decreases as the liquid level increases, The control unit detecting the impedance value from the liquid level sensor at predetermined time intervals; When the impedance value of the liquid level sensor detected at the current startup timing is greater than the impedance value detected at the previous startup timing during the execution of the ink circulation process sequence, it is determined that the ink control mechanism component is not operating normally and is in an abnormal state, When the standby process sequence is executed, if the impedance value of the liquid level sensor detected at the current startup timing is greater than the impedance value detected at the previous startup timing, it is determined that an abnormal state has occurred in which ink is leaking from the ink container.

10. A method for diagnosing an abnormality in an inkjet recording apparatus, comprising:

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