JP6613840B2 - Inspection method of liquid discharge head and liquid discharge apparatus - Google Patents

Description

  The present invention relates to a method for inspecting a liquid discharge head such as an ink jet recording head, and a liquid discharge apparatus, and in particular, discharges liquid from a nozzle by generating pressure vibration by driving an actuator in a liquid in a pressure chamber communicating with the nozzle. The present invention relates to a method for inspecting a liquid discharge head and a liquid discharge apparatus.

  The liquid ejection apparatus is an apparatus that includes a liquid ejection head capable of ejecting liquid as droplets from a nozzle and ejects various liquids from the liquid ejection head. As a typical example of this liquid ejection apparatus, for example, an inkjet recording head that includes an ink jet recording head (hereinafter referred to as a recording head) and performs recording by ejecting liquid ink as ink droplets from the nozzles of the recording head. An image recording apparatus such as an apparatus (printer) can be given. In addition, liquid discharge devices for discharging various types of liquids such as color materials used for color filters such as liquid crystal displays, organic materials used for organic EL (Electro Luminescence) displays, electrode materials used for electrode formation, etc. Is used. The recording head for the image recording apparatus ejects liquid ink, and the color material ejection head for the display manufacturing apparatus ejects a solution of each color material of R (Red), G (Green), and B (Blue). The electrode material discharge head for the electrode forming apparatus discharges a liquid electrode material, and the bioorganic discharge head for the chip manufacturing apparatus discharges a bioorganic solution.

  The liquid discharge head is formed by laminating a plurality of members such as a nozzle plate having nozzles, a substrate on which a pressure chamber is formed, an elastic film that partitions a part of the pressure chamber, and an actuator that generates pressure vibration in the pressure chamber. (For example, refer to Patent Document 1). For example, constituent members such as the substrate on which the nozzle plate and the pressure chamber are formed are bonded with an adhesive. When this adhesive deteriorates and peeling between members occurs, especially when peeling occurs above and below the partition walls that define the pressure chamber, when liquid leaks from this peeled portion or when liquid is discharged There is a risk that a pressure loss may occur and liquid may not be ejected normally from the nozzle. For this reason, in the structure of patent document 1, the structure which suppresses that a nozzle plate peels from a flow-path formation board | substrate is proposed.

JP 2011-201170 A

  However, conventionally, it is possible to detect a malfunction of liquid discharge due to liquid thickening or bubbles, but when separation or the like occurs due to secular change or the like, the above-described liquid thickening discharge There is a problem that it is difficult to detect the separation in distinction from the above-mentioned defects.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid ejection head inspection method capable of detecting separation of partition walls that define pressure chambers and constituent members bonded thereto. And providing a liquid ejecting apparatus.

The liquid ejection device of the present invention has been proposed to achieve the above-described object, and includes a plurality of nozzles arranged in parallel, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed with a partition wall therebetween, And a liquid discharge head that discharges liquid from the nozzle by driving the actuator, and a detection that detects vibration of the liquid in the pressure chamber generated by driving the actuator. A liquid discharge head inspection method comprising a circuit,
A first driving step of driving a first actuator corresponding to the nozzle to be inspected;
A first detection step of detecting vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by driving in the first driving step;
A second driving step of driving both the first actuator and a second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle;
A second detection step of detecting vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by driving in the second driving step;
A peeling detection step for detecting peeling of a member bonded to the partition wall based on a difference between a detection result in the first detection step and a detection result in the second detection step;
An inspection process including the above is executed.

According to the above configuration, the first driving process for driving the first actuator corresponding to the inspection target nozzle, and the vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by the driving in the first driving process are detected. A first detection step, a second drive step of driving together the first actuator and a second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle, and a second drive Based on the difference between the second detection step for detecting the vibration generated in the liquid in the pressure chamber corresponding to the nozzle to be inspected by driving in the step, and the detection result in the first detection step and the detection result in the second detection step. Since the separation of the member bonded to the partition wall is detected, it is difficult to detect the separation of the member that has been conventionally distinguished from the discharge failure due to thickening. It is possible to detect the release more reliably.
In the above configuration, it is preferable that the inspection process is executed when a cumulative load related to the occurrence of peeling exceeds a predetermined determination value.

  According to this configuration, when the cumulative load related to the occurrence of peeling exceeds a predetermined determination value, the inspection process is performed, so that the possibility of occurrence of peeling is relatively low. In this stage, the inspection process can be prevented from being executed, and the processing time can be reduced accordingly. Further, when the liquid is ejected from the nozzle in the inspection process, wasteful consumption of the liquid can be reduced.

  In the above configuration, it is desirable that the greater the cumulative load, the greater the number of second actuators that are driven together with the first actuator of the nozzle to be inspected in the second driving step.

  According to this configuration, when the liquid is ejected from the nozzle in the inspection process, it is possible to efficiently detect the separation while suppressing wasteful consumption of the liquid. That is, as the cumulative load is smaller, the possibility of occurrence of peeling is smaller. Therefore, in the second driving process, the number of second actuators that are driven together with the first actuators of the nozzles to be inspected is reduced, so that the inspection processing is accordingly performed. The amount of liquid consumed can be reduced. On the other hand, the greater the cumulative load, the greater the possibility that peeling has occurred. Therefore, the pressure chamber corresponding to the inspection target nozzle when the first actuator is driven by increasing the number of second actuators driven together with the first actuator of the inspection target nozzle in the second driving step. Since it is possible to further suppress the bending of the partition walls partitioning the film, it is possible to improve the detection accuracy of peeling.

  In the above configuration, as the cumulative load is smaller, the tolerance for determination of separation in the separation detection step is relatively larger, and as the cumulative load is larger, the tolerance for determination of separation in the separation detection step is relatively smaller. Is desirable.

  According to this configuration, the smaller the accumulated load is, the lower the possibility that peeling occurs. Therefore, the detection error in the peeling detection step is set to be relatively large, so that erroneous detection is suppressed. On the other hand, since the possibility that peeling has occurred increases as the cumulative load increases, it is possible to improve the detection accuracy of peeling by setting the tolerance for peeling determination in the peeling detection step to be relatively small.

  In each of the above-described configurations, it is desirable to include a warning step for warning a user when peeling is detected in the peeling detection step.

  According to this configuration, the user can quickly grasp that peeling has occurred, and it is possible to deal with quicker repairs and replacements.

  In each of the above configurations, it is desirable that when the actuator is driven in the first driving step and the second driving step, liquid is ejected from the corresponding nozzle.

  According to this configuration, when the actuator is driven in the first driving process and the second driving process, the liquid is ejected from the corresponding nozzle, so that a larger vibration is applied to the liquid in the pressure chamber. Detection accuracy is improved.

The liquid ejection apparatus of the present invention generates pressure vibrations in a plurality of nozzles arranged in parallel, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed with a partition wall therebetween, and a liquid in the pressure chamber A liquid discharge head having an actuator;
A detection circuit for detecting the vibration of the liquid in the pressure chamber generated by driving the actuator;
A control circuit for controlling the ejection of liquid from the nozzle by driving the actuator;
A liquid ejection device comprising:
The control circuit includes:
Driving the first actuator corresponding to the inspection target nozzle to detect the vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle as a first detection result;
The first actuator and the second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle are driven together to cause vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle. Detected as the detection result of 2,
Separation of a member bonded to the partition wall is detected based on a difference between the first detection result and the second detection result.
Moreover, the inspection method of the liquid discharge head of the present invention proposed for achieving the above object may be performed through the following steps.
That is, a plurality of nozzles arranged side by side, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed across a partition wall, and an actuator that generates pressure vibrations in the liquid in the pressure chamber, An inspection method of a liquid discharge head comprising: a liquid discharge head that discharges liquid from the nozzle by driving; and a detection circuit that detects vibration of the liquid in the pressure chamber generated by driving the actuator,
A first driving step of driving a first actuator corresponding to the nozzle to be inspected;
A first detection step of detecting vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by driving in the first driving step;
A second driving step of driving both the first actuator and a second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle;
A second detection step of detecting vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by driving in the second driving step;
A peeling detection step for detecting peeling of a member bonded to the partition wall based on a difference between a detection result in the first detection step and a detection result in the second detection step;
When the cumulative load related to the occurrence of peeling exceeds a predetermined determination value,
The smaller the cumulative load is, the relatively large tolerance for determination of peeling in the peeling detection step is,
The larger the cumulative load is, the smaller the permissible error of the peeling determination in the peeling detection step is.
According to this configuration, the first driving process for driving the first actuator corresponding to the inspection target nozzle, and the vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by the driving in the first driving process are detected. A first detection step, a second drive step of driving together the first actuator and a second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle, and a second drive Based on the difference between the second detection step for detecting the vibration generated in the liquid in the pressure chamber corresponding to the nozzle to be inspected by driving in the step, and the detection result in the first detection step and the detection result in the second detection step. Since the separation of the member bonded to the partition wall is detected, it is difficult to detect the separation of the member that has been conventionally distinguished from the discharge failure due to thickening. It is possible to detect the release more reliably.
In addition, in the initial stage where the possibility of occurrence of peeling is relatively low by configuring the inspection process when the cumulative load related to occurrence of peeling exceeds a predetermined determination value. The inspection process can be prevented from being executed, and the processing time can be reduced accordingly. Further, when the liquid is ejected from the nozzle in the inspection process, wasteful consumption of the liquid can be reduced.
Furthermore, since the possibility that peeling has occurred is lower as the cumulative load is smaller, the detection error in the peeling detection process is set to be relatively large, so that erroneous detection is suppressed. On the other hand, since the possibility that peeling has occurred increases as the cumulative load increases, it is possible to improve the detection accuracy of peeling by setting the tolerance for peeling determination in the peeling detection step to be relatively small.
Moreover, the inspection method of the liquid ejection head of the present invention may be performed through the following steps.
That is, a plurality of nozzles arranged side by side, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed across a partition wall, and an actuator that generates pressure vibrations in the liquid in the pressure chamber, An inspection method of a liquid discharge head comprising: a liquid discharge head that discharges liquid from the nozzle by driving; and a detection circuit that detects vibration of the liquid in the pressure chamber generated by driving the actuator,
A first driving step of driving a first actuator corresponding to the nozzle to be inspected;
A first detection step of detecting vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by driving in the first driving step;
A second driving step of driving both the first actuator and a second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle;
A second detection step of detecting vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by driving in the second driving step;
A peeling detection step for detecting peeling of a member bonded to the partition wall based on a difference between a detection result in the first detection step and a detection result in the second detection step;
When the cumulative load related to the occurrence of peeling exceeds a predetermined determination value,
The larger the cumulative load is, the more the number of second actuators that are driven together with the first actuators of the nozzles to be inspected is increased in the second driving step.
According to this configuration, the first driving process for driving the first actuator corresponding to the inspection target nozzle, and the vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by the driving in the first driving process are detected. A first detection step, a second drive step of driving together the first actuator and a second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle, and a second drive Based on the difference between the second detection step for detecting the vibration generated in the liquid in the pressure chamber corresponding to the nozzle to be inspected by driving in the step, and the detection result in the first detection step and the detection result in the second detection step. Since the separation of the member bonded to the partition wall is detected, it is difficult to detect the separation of the member that has been conventionally distinguished from the discharge failure due to thickening. It is possible to detect the release more reliably.
In addition, in the initial stage where the possibility of occurrence of peeling is relatively low by configuring the inspection process when the cumulative load related to occurrence of peeling exceeds a predetermined determination value. The inspection process can be prevented from being executed, and the processing time can be reduced accordingly. Further, when the liquid is ejected from the nozzle in the inspection process, wasteful consumption of the liquid can be reduced.
Furthermore, when the liquid is ejected from the nozzle in the inspection process, it is possible to efficiently detect the separation while suppressing wasteful consumption of the liquid. That is, as the cumulative load is smaller, the possibility of occurrence of peeling is smaller. Therefore, in the second driving process, the number of second actuators that are driven together with the first actuators of the nozzles to be inspected is reduced, so that the inspection processing is accordingly performed. The amount of liquid consumed can be reduced. On the other hand, the greater the cumulative load, the greater the possibility that peeling has occurred. Therefore, the pressure chamber corresponding to the inspection target nozzle when the first actuator is driven by increasing the number of second actuators driven together with the first actuator of the inspection target nozzle in the second driving step. Since it is possible to further suppress the bending of the partition walls partitioning the film, it is possible to improve the detection accuracy of peeling.
In the above configuration, as the cumulative load is smaller, the tolerance for determination of separation in the separation detection step is relatively larger, and as the cumulative load is larger, the tolerance for determination of separation in the separation detection step is relatively smaller. Is desirable.
According to this configuration, the smaller the accumulated load is, the lower the possibility that peeling occurs. Therefore, the detection error in the peeling detection step is set to be relatively large, so that erroneous detection is suppressed. On the other hand, since the possibility that peeling has occurred increases as the cumulative load increases, it is possible to improve the detection accuracy of peeling by setting the tolerance for peeling determination in the peeling detection step to be relatively small.
Moreover, in each said structure, it is desirable to include the warning process of warning to a user, when peeling is detected in the said peeling detection process.
According to this configuration, the user can quickly grasp that peeling has occurred, and it is possible to deal with quicker repairs and replacements.
Furthermore, in each of the above-described configurations, it is desirable that liquid is ejected from the corresponding nozzle when the actuator is driven in the first driving step and the second driving step.
According to this configuration, when the actuator is driven in the first driving process and the second driving process, the liquid is ejected from the corresponding nozzle, so that a larger vibration is applied to the liquid in the pressure chamber. Detection accuracy is improved.
Moreover, the liquid ejection apparatus of the present invention may have the following configuration.
That is, a liquid discharge head having a plurality of nozzles arranged side by side, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed across a partition wall, and an actuator that generates pressure vibrations in the liquid in the pressure chambers;
A detection circuit for detecting the vibration of the liquid in the pressure chamber generated by driving the actuator;
A control circuit for controlling the ejection of liquid from the nozzle by driving the actuator;
A liquid ejection device comprising:
The control circuit includes:
Driving the first actuator corresponding to the inspection target nozzle to detect the vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle as a first detection result;
The first actuator and the second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle are driven together to cause vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle. Detected as the detection result of 2,
Based on the difference between the first detection result and the second detection result, an inspection process for detecting the separation of the member joined to the partition wall is performed with a determination value in which the cumulative load related to the occurrence of the separation is predetermined. Execute if exceeded,
The smaller the cumulative load, the larger the permissible error in the judgment of peeling, and the larger the cumulative load, the smaller the permissible error in the judgment of peeling.
Furthermore, the liquid ejection apparatus of the present invention may have the following configuration.
That is, a liquid discharge head having a plurality of nozzles arranged side by side, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed across a partition wall, and an actuator that generates pressure vibrations in the liquid in the pressure chambers;
A detection circuit for detecting the vibration of the liquid in the pressure chamber generated by driving the actuator;
A control circuit for controlling the ejection of liquid from the nozzle by driving the actuator;
A liquid ejection device comprising:
The control circuit includes:
Driving the first actuator corresponding to the inspection target nozzle to detect the vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle as a first detection result;
The first actuator and the second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle are driven together, and vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle is first detected. Detected as the detection result of 2,
Based on the difference between the first detection result and the second detection result, an inspection process for detecting the separation of the member bonded to the partition wall is performed using a determination value in which the cumulative load related to the occurrence of the separation is predetermined. Execute if exceeded,
The number of second actuators driven together with the first actuator of the nozzle to be inspected is increased as the cumulative load increases.

2 is a perspective view illustrating an internal configuration of the printer. FIG. FIG. 3 is a diagram illustrating a configuration of a recording head. 2 is a block diagram illustrating an electrical configuration of a printer. FIG. It is a wave form diagram explaining the structure of the drive pulse for a test | inspection. FIG. 3 is a diagram illustrating a circuit configuration for detecting a recording head failure. FIG. 3 is a diagram illustrating a circuit configuration for detecting a recording head failure. It is a flowchart explaining an inspection process. It is the graph which showed the waveform of the back electromotive force signal. It is an image figure explaining the inspection process in the 2nd Embodiment of this invention. It is a table | surface which shows the specific example of the test | inspection process in 2nd Embodiment. It is the graph which showed the waveform of the 1st counter electromotive force signal output from a vibration detection circuit, and the 2nd counter electromotive force signal. It is a wave form diagram which shows an example of the waveform of a micro vibration drive pulse. It is a wave form diagram which shows an example of the waveform of a small dot drive pulse.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the following, an ink jet recording apparatus (hereinafter referred to as a printer) will be described as an example of the liquid ejection apparatus of the present invention.

  FIG. 1 is a perspective view showing the configuration of the printer 1. The printer 1 is provided with a recording head 2 that is a kind of liquid ejection head and a carriage 4 to which an ink cartridge 3 that is a kind of liquid supply source is detachably attached, and below the recording head 2 during a recording operation. The arranged platen 5, the carriage 4 that moves the carriage 4 back and forth in the paper width direction of the recording paper 6 (recording medium and landing target), that is, the main scanning direction, and the sub-scanning orthogonal to the main scanning direction And a paper feed mechanism 8 that conveys the recording paper 6 in the direction. A configuration in which the ink cartridge 3 is disposed on the main body side of the printer 1 and is supplied from the ink cartridge 7 to the recording head 2 through an ink supply tube may be employed.

  The carriage 4 is attached while being supported by a guide rod 9 installed in the main scanning direction, and is configured to move in the main scanning direction along the guide rod 9 by the operation of the carriage moving mechanism 7. ing. The position of the carriage 4 in the main scanning direction is detected by the linear encoder 10, and the detection signal is transmitted to the CPU 35 (see FIG. 3) of the printer controller 31. The linear encoder 10 outputs an encoder pulse corresponding to the scanning position of the recording head 2 as position information in the main scanning direction. For this reason, the CPU 35 can recognize the scanning position of the recording head 2 mounted on the carriage 4 based on the received encoder pulse. Thereby, the CPU 35 can control the recording operation by the recording head 2 while recognizing the scanning position of the carriage 4 (recording head 2) based on the encoder pulse from the linear encoder 10. The printer 1 is bi-directional between when the carriage 4 moves from the home position toward the opposite end and when the carriage 4 returns from the opposite end to the home position. So-called bidirectional recording in which characters, images, etc. are recorded on the recording paper 6 is possible.

  2A and 2B are diagrams illustrating a configuration of the recording head 2 according to the present embodiment, in which FIG. 2A is a plan view of the recording head 2, FIG. 2B is a cross-sectional view taken along the line AA ′ in FIG. It is BB 'sectional view taken on the line in (a). In addition, illustration of the protective substrate 19 is abbreviate | omitted in FIG.2 (c). Moreover, although the structure for three nozzles is illustrated in FIG. 2, the structure corresponding to the remaining other nozzles is also the same. The recording head 2 in this embodiment is configured by stacking a pressure chamber substrate 14, a nozzle plate 15, an elastic film 16, an insulating film 17, a piezoelectric element 18, a protective substrate 19, and the like.

  The pressure chamber substrate 14 is a plate material made of, for example, a silicon single crystal substrate. In the pressure chamber substrate 14, a plurality of pressure chambers 20 are arranged in parallel in the width direction (nozzle row direction) with the partition wall 13 interposed therebetween. In the present embodiment, 360 pressure chambers 20 are formed per inch. A communication portion 21 is formed in a region outside the side opposite to the side communicating with the nozzle 23 in the longitudinal direction of the pressure chamber substrate 14 in the longitudinal direction of the pressure chamber 20 (direction perpendicular to the nozzle row direction). Each pressure chamber 20 communicates with each other via an ink supply path 22 provided for each pressure chamber 20. The communication portion 21 constitutes a part of a reservoir 27 that communicates with a reservoir portion 29 of the protective substrate 19 described later and serves as a common ink chamber for the pressure chambers 20. The ink supply path 22 is formed with a width narrower than that of the pressure chamber 20, and imparts flow path resistance to the ink flowing into the pressure chamber 20 from the communication portion 21. Channels such as the pressure chamber 20 and the ink supply channel 22 in the pressure chamber substrate 14 are formed by anisotropic etching.

On the lower surface of the pressure chamber substrate 14, a nozzle plate 15 in which a plurality of nozzles 23 corresponding to each pressure chamber 20 are arranged in a line is joined by an adhesive 12. As a result, the opening on the lower surface side of the pressure chamber 20 is sealed by the nozzle plate 15 to define the bottom of the pressure chamber 20. An elastic film 16 made of, for example, silicon dioxide (SiO ₂ ) is formed on the upper surface of the pressure chamber substrate 14. The portion of the elastic film 16 that seals the opening of the pressure chamber 20 functions as an operating surface. An insulating film 17 made of zirconium oxide (ZrO ₂ ) is formed on the elastic film 16, and a lower electrode 24, a piezoelectric body 25, and an upper electrode 26 are formed on the insulating film 17. These are laminated to form the piezoelectric element 18 (a kind of actuator in the present invention).

  In general, one of the electrodes of the piezoelectric element 18 is a common electrode for the plurality of piezoelectric elements 18, and the other electrode (individual electrode) and the piezoelectric body 25 are patterned for each pressure chamber 20. . And the part which a piezoelectric distortion produces by the application of the voltage to both electrodes functions as a piezoelectric material active part. In this embodiment, the lower electrode 24 is a common electrode of the piezoelectric element 18 and the upper electrode 26 is an individual electrode of the piezoelectric element 18. However, the polarization direction of the piezoelectric body 25, the convenience of the drive circuit and wiring, etc. Therefore, it is possible to adopt a configuration in which these are entirely reversed. In any case, a piezoelectric active part is formed for each pressure chamber 20.

  On the surface of the pressure chamber substrate 14 on the piezoelectric element 18 side, a protective substrate 19 having a piezoelectric element holding portion 28 that is a space having a size that does not hinder the displacement is bonded to a region facing the piezoelectric element 18. Yes. Further, the protective substrate 19 is provided with a reservoir portion 29 in a region corresponding to the communication portion 21 of the pressure chamber substrate 14. The reservoir portion 29 is formed in the protective substrate 19 as a through hole having a rectangular opening shape elongated along the direction in which the pressure chambers 20 are juxtaposed. As described above, the reservoir portion 29 is connected to the communication portion 21 of the pressure chamber substrate 14. The reservoir 27 is defined in communication. The reservoir 27 is provided for each type of ink (for each color), and common ink is stored in the plurality of pressure chambers 20.

  In the recording head 2 configured as described above, ink is taken from the ink cartridge 3 and filled from the reservoir 27 to the nozzle 23 with ink. Then, by supplying a drive signal from the printer main body side, an electric field corresponding to the potential difference between the two electrodes is applied between the lower electrode 24 and the upper electrode 26 corresponding to the pressure chamber 20, and the piezoelectric element 18 and the operation surface. When the (elastic film 16) is bent and deformed, a pressure fluctuation occurs in the pressure chamber 20. By controlling this pressure fluctuation, ink is ejected from the nozzle 23, or the meniscus in the nozzle 23 is vibrated slightly to the extent that ink is not ejected.

  FIG. 3 is a block diagram illustrating an electrical configuration of the printer 1. The printer 1 in this embodiment is schematically configured by a printer controller 31 and a print engine 32. The printer controller 31 includes an external interface (external I / F) 33 that receives print data from an external device such as a host computer, a memory 34 that stores control programs for various controls, various data, and the like. A CPU 35 that performs overall control of each unit in accordance with a control program stored in the memory 34, and a drive signal generation circuit 36 that generates a drive signal to be supplied to the recording head 2 are provided. The print engine 32 includes the recording head 2, the carriage moving mechanism 7, the paper feed mechanism 8, the linear encoder 10, and the vibration detection circuit 38.

  The drive signal generation circuit 36 includes a drive voltage supply source and a constant voltage supply source (both not shown), outputs a drive signal COM from the drive voltage supply source, and generates a DC voltage VBS from the constant voltage supply source. Output. The drive voltage supply source is electrically connected to the upper electrode 26 that is a drive electrode of the piezoelectric element 18 via a pulse selection switch 37 (see FIG. 5 or 6) provided for each piezoelectric element 18. The constant voltage supply source is shared by the piezoelectric elements 18 via a switch 39 provided in common to the piezoelectric elements 18 belonging to the same nozzle row and a detection resistor 40 connected in parallel with the switch 39. It is electrically connected to the lower electrode 24 which is an electrode (see FIG. 5 or FIG. 6).

  The head controller 30 of the recording head 2 performs ejection control of ink (a kind of liquid in the present invention) based on the gradation data SI sent from the printer controller 31. In this embodiment, gradation data SI composed of 2 bits is transmitted in synchronization with a clock signal, and is sequentially input to a shift register and a latch circuit (not shown) of the head controller 30. The latched gradation data SI is output to a decoder (not shown). The decoder generates pulse gradation data for selecting a drive pulse included in the drive signal COM based on the upper bit group and the lower bit group of the recording data.

  Further, the drive signal COM from the drive signal generation circuit 36 is supplied to the head controller 30. This drive signal COM is input to the pulse selection switch 37 of the head controller 30 (see FIG. 5 or FIG. 6). The upper electrode 26 of the piezoelectric element 18 is connected to the output side of the pulse selection switch 37. The pulse selection switch 37 selectively applies a drive pulse included in the drive signal COM to the piezoelectric element 18 based on the pulse gradation data. The pulse selection switch 37 that operates in this manner functions as a kind of selection supply means. The pulse selection switch 37 also functions as a kind of switching mechanism for switching the connection state or the disconnection state of the piezoelectric element 18 with respect to the drive signal generation circuit 36 when an inspection process described later is performed. The operation of the pulse selection switch 37 in the inspection process will be described later.

  A vibration detection circuit 38 is connected to the lower electrode 24 side of the piezoelectric element 18 via a switch 39. The switch 39 is switch-controlled according to a switch signal CS output from the CPU 35. The vibration detection circuit 38 detects a back electromotive force signal of the piezoelectric element 18 based on vibration (residual vibration) generated in the ink in the pressure chamber when the piezoelectric element 18 is driven by the inspection drive pulse Pd (see FIG. 4). Is output to the printer controller 31 side. The CPU 35 of the printer controller 31 inspects the presence or absence of a failure of the recording head 2 based on the back electromotive force signal output from the vibration detection circuit 38. Therefore, the vibration detection circuit 38 and the printer controller 31 function as a detection circuit in the present invention, and detect the vibration of the ink in the pressure chamber using the piezoelectric element 18 as a vibration sensor.

  The printer 1 according to the present invention starts an inspection process when a predetermined inspection execution condition is satisfied, and executes an inspection process for the recording head 2. The failure of the recording head 2 specifically refers to the pressure chamber substrate 14 in which the pressure chamber 20 is formed and other members joined to the pressure chamber substrate 14, that is, the nozzle plate 15 or the elasticity in this embodiment. It means a state where peeling from the film 16 has occurred. In addition, the “state where peeling has occurred” includes a state where the adhesive force is remarkably lowered to the extent that ink ejection is affected even if the peeling does not occur completely. In particular, when separation occurs on the upper end surface (opposite to the nozzle plate side) or the lower end surface (nozzle plate side) of the partition wall 13 that separates the pressure chambers 20, the movement is restricted in the state before the separation. Since the upper end surface or the lower end surface of the partition wall 13 is released, when the internal pressure of the pressure chamber 20 changes, the partition wall 13 is easily displaced or easily bent. As a result, a part of the pressure when ink is ejected from the nozzle 23 is used for the displacement of the partition wall 13, and as a result, the amount of ink ejected from the nozzle 23 and the flying speed are significantly reduced with respect to the target value. However, in the worst case, there is a possibility that an ejection failure such as ink not being ejected may occur. Such a state is regarded as a failure.

  The inspection execution condition can be arbitrarily set. Specifically, the accumulated value of the load directly or indirectly related to the occurrence of the above-described peeling (accumulated load in the present invention), more specifically, the usage time of the printer 1 (for example, ejecting ink from the nozzles 23). (The integrated value of the operating time), the number of ejections (for example, the sum of the number of ejections of all the nozzles or the integrated value of the average values), the total number of prints of the recording medium, or the like is a predetermined determination value. It can be a condition that it has been exceeded. These cumulative loads increase the possibility of occurrence of peeling as the value increases. It is desirable to weight these accumulated loads according to the usage environment, that is, the environmental temperature and humidity. For example, when used in an environment where the ambient temperature and humidity are relatively high, weighting the cumulative load such as the actual usage time and the cumulative value of the number of discharges (increase it from the actual value) It is desirable to set so that the inspection process is executed at an early stage. Alternatively, instead of performing weighting, the determination value can be changed according to the use environment. In addition, this type of printer may be inspected for ejection failure due to thickening of ink, but when the inspection result of ejection failure due to thickening results in suspicion of peeling. It can also be set as an execution condition (the ejection failure inspection has been conventionally performed by various methods, and detailed description thereof will be omitted). It is also possible to make a condition when a user gives an instruction to execute inspection processing via a printer driver or the like. Hereinafter, the inspection process of the recording head 2 when the inspection execution condition is satisfied will be described.

  When it is determined that the above-described inspection execution condition is satisfied, that is, the accumulated load exceeds a predetermined determination value, the printer controller 31 proceeds to inspection processing, and the inspection target is selected from all the nozzles 23 of the recording head 2. When a nozzle is selected and the inspection drive pulse shown in FIG. 5 is applied to the piezoelectric element 18 corresponding to the inspection target nozzle, an inspection process is performed based on the back electromotive force generated in the piezoelectric element 18. The nozzles to be inspected may be selected, for example, sequentially from the nozzle located at one end of the nozzle row toward the other end, or as described above, the result of the ejection failure inspection due to thickening Based on the above, a nozzle at a position where peeling is suspected may be selected. As the inspection drive pulse, those having various waveforms can be adopted as long as they can change the pressure of the ink in the pressure chamber 20, but in this embodiment, the inspection shown in FIG. Drive pulse Pd is used.

  FIG. 4 is a waveform diagram of the inspection drive pulse Pd. The inspection drive pulse Pd in this embodiment includes a preliminary expansion element p11, an expansion hold element p12, a contraction element p13, a contraction hold element p14, and a return element p15. The preliminary expansion element p11 is a waveform element whose potential changes from the reference potential VB to the expansion potential VL toward the ground potential GND. The expansion hold element p12 is a waveform element that maintains the expansion potential VL that is the terminal potential of the preliminary expansion element p11 for a predetermined time. The contraction element p13 is a waveform element in which the potential changes from the expansion potential VL to the contraction potential VH beyond the reference potential VB with a relatively steep gradient from the expansion potential VL to the contraction potential VH. In the present embodiment, the potential difference Vd1 from the expansion potential VL to the contraction potential VH and the gradient of the potential change of the contraction element p13 are set so that ink can be ejected from the nozzles 23. The contraction hold element p14 is a waveform element that maintains the contraction potential VH for a predetermined time. The return element p15 is a waveform element that returns the potential from the contraction potential VH to the reference potential VB. As the inspection driving pulse Pd, a printing driving pulse can be used, or a dedicated one for inspection processing can be used.

  When the inspection drive pulse Pd configured as described above is applied to the piezoelectric element 18, first, the piezoelectric element 18 is deflected to the outside of the pressure chamber 20 (side away from the nozzle plate 15) by the preliminary expansion element p 11. As a result, the pressure chamber 20 expands from the reference volume corresponding to the reference potential VB to the expansion volume corresponding to the expansion potential VL. By this expansion, the ink meniscus in the nozzle 23 is drawn from the standby position (the position of the meniscus when the pressure chamber 20 is maintained at the reference volume) to the pressure chamber 20 side along the nozzle axis direction. The expansion state of the pressure chamber 20 is maintained for a certain time by the expansion hold element p12. After the hold by the expansion hold element p12, the piezoelectric element 18 bends inside the pressure chamber 20 (the side close to the nozzle plate 15) by the contraction element p13. Accordingly, the pressure chamber 20 is rapidly contracted from the expansion volume to the contraction volume corresponding to the contraction potential VH. As a result, the ink in the pressure chamber 20 is pressurized and the meniscus that has been drawn into the pressure chamber 20 side exceeds the standby position along the nozzle axis direction on the discharge side opposite to the pressure chamber 20 side. Pushed out. Thereby, an ink droplet is ejected from the nozzle 23. Subsequently, when the return element p15 is applied, the piezoelectric element 18 returns to the steady position corresponding to the reference potential VB. Accordingly, the pressure chamber 20 expands from the contracted volume to the reference volume corresponding to the reference potential VB and returns. As a result, the meniscus is again drawn into the pressure chamber. The inspection drive pulse Pd in the present embodiment is configured to cause a relatively large pressure fluctuation in the ink in the pressure chamber 20, so that ink is ejected from the nozzle 23, but the ink is not necessarily ejected from the nozzle 23. May not be discharged. However, in the driving process in the inspection process described later, when the piezoelectric element 18 is driven by the inspection driving pulse Pd, the ink is ejected from the corresponding nozzle 23, which is larger than the ink in the pressure chamber. Since vibration can be applied, the detection accuracy is improved.

  5 and 6 are diagrams illustrating a circuit configuration for detecting a failure of the recording head 2 based on the back electromotive force signal of the piezoelectric element 18. Note that FIG. 5 shows a case of a single inspection in which only the inspection target nozzle is driven, and FIG. 6 shows a case of an assist inspection in which the inspection target nozzle and a nozzle (assist nozzle) adjacent thereto are driven. 5 and 6 illustrate the configuration of three nozzles, and the configuration corresponding to the other nozzles 23 is omitted for the sake of convenience, but the piezoelectric element 18 and the pulse selection switch 37 configure the same nozzle row. The number of nozzles 23 is provided. In the figure, the central piezoelectric element 18 is a piezoelectric element 18a (first actuator) corresponding to the inspection target nozzle, and both sides thereof are piezoelectric elements 18b (first operation) corresponding to the assist nozzle adjacent to the inspection target nozzle. 2 actuators).

  As described above, the drive voltage supply source of the drive signal generation circuit 36 is connected to the upper electrode 26 of the piezoelectric element 18 via the pulse selection switch 37 for each piezoelectric element 18, and the constant voltage supply source is the switch 39 and It is electrically connected to the lower electrode 24 of the piezoelectric element 18 through a detection resistor 40 connected in parallel with the switch 39. The switch 39 is composed of, for example, a MOS-FET, and is switched on during application of the inspection drive pulse Pd (pressure vibration generation period) (FIGS. 5A and 6A). In this case, a current (high frequency component) flows through the switch 39 side. On the other hand, in the detection section in the period t6 of the period T2, it is switched off (FIGS. 5B and 6B). In this case, the current Id flows through the detection resistor 40 side.

  Here, after the piezoelectric element 18 is driven by the test drive pulse Pd, the working surface (elastic film) that seals the upper surface side opening of the pressure chamber 20 according to the pressure vibration generated in the ink in the pressure chamber 20. 16) vibrates. Along with this, damping vibration (residual vibration) is also generated in the piezoelectric element 18, and a back electromotive force based on this residual vibration is generated. The vibration detection circuit 38 obtains a back electromotive force signal Sc (detection signal) of the piezoelectric element 18 by amplifying and binarizing the potential difference between both ends of the detection resistor 40. In the case of so-called dot missing where ink is not ejected from the nozzle 23, or when the amount of ink and the flying speed are extremely low compared to the normal nozzle 23 even when ink is ejected from the nozzle 23 The periodic component, amplitude component, and phase component of the detection signal are different from those in the normal state. Detection of ejection failure based on the back electromotive force signal Sc is well known in the art and will not be described in detail. However, this detection method can detect ejection failure due to ink thickening or bubbles.

  By the way, when the pressure chamber substrate 14 and other members bonded to the pressure chamber substrate 14, that is, the nozzle plate 15 or the elastic film 16 in this embodiment are peeled off, or until peeling does not occur. Even when the bonding force is significantly reduced, the amount of ink and the flying speed are reduced as compared with the case of the normal nozzle 23, as in the case of thickening the ink or mixing bubbles. However, there is a problem that it is difficult to find the difference between the inspection result when the peeling occurs and the inspection result when the ink is thickened or ejection failure due to bubbles occurs, and it is difficult to detect the peeling. It was. In this regard, the printer 1 according to the present invention includes a detection signal when the piezoelectric element 18a corresponding to the inspection target nozzle is driven alone, and a nozzle adjacent to the inspection target nozzle 23a and at least the inspection target nozzle 23a ( (Assist nozzle) is characterized in that the above-described separation is detected based on a difference from a detection signal when the piezoelectric element 18b corresponding to the assist nozzle 23b is simultaneously driven. Here, the assist nozzle means the nozzle 23b that is driven simultaneously with the inspection target nozzle 23a in the assist inspection described later, that is, driven by applying the inspection drive pulse Pd to the corresponding piezoelectric element 18b. However, this does not necessarily mean only the nozzle adjacent to the inspection target nozzle 23a.

  As described above, in the printer 1 according to the present invention, the single inspection in which only the inspection target nozzle 23a is driven (single driving) and the inspection is performed, and the inspection target nozzle 23a and the assist nozzle 23b are simultaneously driven (assist driving). Assist inspection is performed. When the nozzle 23 located at the end of the nozzle row is selected as the inspection target nozzle 23a, there is only the nozzle 23 adjacent to one of the inspection target nozzles 23a. In this case, this one nozzle 23 Is the assist nozzle 23b. In short, at least one nozzle 23 adjacent to the inspection target nozzle 23a in the nozzle row direction is the assist nozzle 23b. In the following, the inspection is performed by driving a total of three piezoelectric elements 18, that is, the piezoelectric elements 18 corresponding to the nozzles to be inspected and the piezoelectric elements 18 corresponding to the assist nozzles on both sides thereof. In some cases, the nozzle is driven. This point will be described later.

  FIG. 7 is a flowchart for explaining the inspection process. In the inspection process, first, a single inspection is performed (step S1). Here, in FIG. 5, the piezoelectric element 18 at the center is the piezoelectric element 18a corresponding to the inspection target nozzle 23a, and the both sides thereof are the piezoelectric elements 18b corresponding to the assist nozzle 23b. In the single inspection, the switch 39 is turned on by the switching signal, and only the pulse selection switch 37 of the piezoelectric element 18a corresponding to the inspection target nozzle 23a is turned on (FIG. 5A). The pulse selection switch 37 of the piezoelectric element 18 corresponding to a nozzle 23 other than the inspection target nozzle 23a (including the assist nozzle 23b) is turned off.

  Then, the inspection drive pulse Pd is applied to the piezoelectric element 18a corresponding to the inspection target nozzle 23a. Thereby, only the piezoelectric element 18a corresponding to the inspection target nozzle 23a is driven (first driving process (step S2)). Thereby, a pressure fluctuation occurs in the pressure chamber 20 corresponding to the inspection target nozzle. Along with the damping vibration (residual vibration) of the pressure vibration, the working surface of the pressure chamber 20 and the piezoelectric element 18a also vibrate, and a back electromotive force is generated in the piezoelectric element 18a due to this vibration. Immediately after the test drive pulse Pd is applied, the switch 39 is turned off by the switching signal (FIG. 5B). Thereby, the current Id (high frequency component) based on the back electromotive force of the piezoelectric element 18a corresponding to the inspection target nozzle 23a flows through the detection resistor 40. Then, the vibration detection circuit 38 detects the first counter electromotive force signal Sc1 as vibration generated by driving from the potential difference between both ends of the detection resistor 40 (first detection step (step S3)). The first counter electromotive force signal Sc1 is output to the CPU 35 of the printer controller 31. Here, if separation occurs at least one of the upper and lower sides of the partition wall 13 that defines the pressure chamber 20 of the inspection target nozzle 23a, the partition wall 13 is easily bent when the internal pressure of the pressure chamber 20 increases. Because of that, the pressure will escape. As a result, the pressure vibration generated in the pressure chamber 20 corresponding to the nozzle to be inspected is smaller than that in a normal state (when no peeling occurs). As a result, the influence appears in the amplitude component of the first counter electromotive force signal Sc1.

  Next, an assist inspection is performed (step S4). In the assist inspection, first, the switch 39 is turned on, and the pulse selection switch 37 of the piezoelectric element 18a corresponding to the inspection target nozzle 23a and the pulse selection switch 37 of the piezoelectric element 18b corresponding to the assist nozzles 23b on both sides are turned on. (FIG. 6A). The pulse selection switches 37 of other piezoelectric elements 18 other than these piezoelectric elements 18 are turned off. Then, the inspection drive pulse Pd is applied to the piezoelectric element 18a corresponding to the inspection target nozzle 23a. At the same time, the inspection drive pulse Pd is also applied to the piezoelectric element 18b corresponding to the assist nozzle 23b. As a result, the piezoelectric elements 18 are simultaneously driven (second driving step (step S5)), and the pressure chamber 20 corresponding to the inspection target nozzle 23a and the pressure chamber 20 corresponding to the assist nozzle 23b have the same timing. Pressure fluctuation occurs. Here, as described above, the internal pressure of the pressure chamber 20 of the inspection target nozzle 23a is maintained even when peeling occurs in at least one of the upper and lower sides of the partition wall 13 that defines the pressure chamber 20 of the inspection target nozzle. When the pressure changes, the internal pressure also changes in the pressure chamber 20 adjacent to the pressure chamber 20, so that the partition wall 13 is prevented from being bent. Thereby, since it is suppressed that the pressure in the pressure chamber 20 of the test object nozzle 23a falls compared with the case of said single test | inspection, even if peeling should have arisen, the pressure corresponding to the test object nozzle 23a In the chamber 20, pressure vibrations similar to those in the normal state occur.

  Subsequently, in a state where the pulse selection switch 37 on the inspection target nozzle 23a side is kept on, the switch 39 is turned off by the switching signal and the pulse selection switch 37 of the piezoelectric element 18 on the assist nozzle 23b side is turned off. (FIG. 6B). Thereby, only the current Id based on the back electromotive force of the piezoelectric element 18a corresponding to the inspection target nozzle 23a flows through the detection resistor 40. That is, the current based on the counter electromotive force of the piezoelectric element 18b corresponding to the assist nozzle 23b does not flow into the detection resistor 40. Then, the vibration detection circuit 38 detects the second counter electromotive force signal Sc2 as vibration generated by driving from the potential difference between the both ends of the detection resistor 40 (second detection step (step S6)). Is output to the CPU 35 of the printer controller 31. Then, the CPU 35 determines whether or not there is a failure (peeling) of the recording head 2 based on the first counter electromotive force signal Sc1 and the second counter electromotive force signal Sc2 (peeling detection step (step S7)).

  FIG. 8 is a graph showing waveforms of the first counter electromotive force signal Sc1 and the second counter electromotive force signal Sc2 output from the vibration detection circuit 38. FIG. 8 (a) shows a problem caused by ink thickening or bubbles, or when the above-described peeling does not occur, and FIG. 8 (b) shows a case where ejection failure occurs due to ink thickening. FIG. 8C shows a case where a failure due to peeling has occurred. Note that the second counter electromotive force signal Sc2 in FIG. 8 is generated when the nozzles 23 located on both sides of the inspection target nozzle 23a are driven as the assist nozzles 23b during the assist drive (that is, when the three nozzles 23 are driven simultaneously). The waveform is shown. As shown in FIG. 8A, in the normal state, both the first back electromotive force signal Sc1 and the second back electromotive force signal Sc2 have a relatively large amplitude, and the difference between the two is also the same. small. Further, as shown in FIG. 8B, when the ejection failure is caused by the increased viscosity of the ink, the first counter electromotive force signal Sc1 and the second counter electromotive force signal are compared with those in the normal state. Both of the amplitudes of Sc2 are small. However, the difference in amplitude between the two is not much different from that in the normal state. However, as shown in FIG. 8C, when a failure due to peeling occurs, the magnitude of the amplitude of the second counter electromotive force signal Sc2 at the time of assist driving is the first counter electromotive force at the time of ink thickening. The magnitude of the amplitude of the first counter electromotive force signal Sc1 during the single drive is the second counter electromotive force for the reason described above, while the amplitude is approximately the same as the amplitude of the signal Sc1 and the second counter electromotive force signal Sc2. It greatly decreases with respect to the electromotive force signal Sc2.

  Therefore, in step S7, the CPU 35 determines whether or not the recording head 2 has failed based on the difference between the first counter electromotive force signal Sc1 and the second counter electromotive force signal Sc2, that is, the amplitude difference Δa. To do. Specifically, for example, the obtained difference Δa is compared with a preset threshold value. When Δa is equal to or greater than the threshold value, it is determined that a failure, that is, separation between the pressure chamber substrate 14 and another member bonded to the pressure chamber substrate 14 or a decrease in adhesive force has occurred. Yes (Yes). On the other hand, when the difference Δa is less than the threshold value, it is determined that no peeling or the like has occurred (No). Such an inspection process is sequentially performed on each nozzle 23, so that the failure location is roughly specified based on the amplitude difference Δa between the first counter electromotive force signal Sc1 and the second counter electromotive force signal Sc2. It is also possible. The determination is not limited to the amplitude difference Δa between the first counter electromotive force signal Sc1 and the second counter electromotive force signal Sc2, and may be determined by a phase difference, a period difference, or a combination thereof. When peeling is detected in step S7, the CPU 35 displays, for example, that a failure has been detected on a liquid crystal display unit provided in the main body of the printer 1, or a computer connected to the printer 1. A warning is given to the user by displaying it through a printer driver or the like to be executed (warning step (step S8)).

  As described above, in the printer 1 according to the present invention, when the piezoelectric element 18a corresponding to the inspection target nozzle 23a is driven alone, it relates to the vibration generated in the ink in the pressure chamber 20 corresponding to the inspection target nozzle 23a. A detection signal and a detection signal related to vibration generated in the ink in the pressure chamber 20 corresponding to the inspection target nozzle 23a when the piezoelectric elements 18a and 18b corresponding to the inspection target nozzle 23a and the assist nozzle 23b are simultaneously driven. Based on the difference, it is possible to more reliably detect the peeling of the member, which was difficult to detect in the past by distinguishing it from the ejection failure due to thickening.

  FIG. 9 is an image diagram for explaining an inspection process according to the second embodiment of the present invention. In this embodiment, the circuit configuration for detecting a failure and the configuration of the recording head 2 are the same as those in the first embodiment. The present embodiment is characterized in that the detection accuracy is improved as the cumulative load approaches the component life assumed in the specifications of the recording head 2 (particularly, the life of the bonded portion by the adhesive 12). In order to increase the detection accuracy, the pressure generated in the ink in the pressure chamber 20 corresponding to the inspection target nozzle 23a is increased, and the pressure corresponding to the assist nozzle 23b is used to suppress the bending of the partition wall 13 of the inspection target nozzle 23. Increasing the vibration (residual vibration) generated in the ink in the chamber 20, increasing the number of assist nozzles 23b that are driven simultaneously with the inspection target nozzle 23 during assist driving, or a combination thereof. . Note that the vibration generated in the ink in the pressure chamber 20 can be increased by increasing the drive voltage Vd of the test drive pulse or changing the waveform of the test drive pulse itself, as will be described later. be able to.

  However, in the configuration in which ink is ejected from the nozzles 23 at the time of inspection, the number of assist nozzles 23b that are driven at the same time is increased in order to increase detection accuracy, or greater vibration is generated in the ink in the pressure chamber 20. There is a problem that a lot of ink is consumed. For this reason, in the present embodiment, the inspection process is not performed in the initial stage where the cumulative load is relatively small, and after the cumulative load exceeds a predetermined determination value, the detection accuracy in the inspection process depends on the cumulative load. Increased sequentially. More specifically, for example, when the cumulative load is related to time, as shown in FIG. 9, the first determination value is the time when the component lifetime assumed in the specification is 100%, which is 80%. The time when 90% of the component life is reached is set as the second determination value, and the time when 95% of the component life is reached is set as the third determination value. The inspection process is not performed until the first determination value, and the inspection process of the recording head 2 is executed on condition that the accumulated load becomes the above-described determination values. In the case of the first determination value, the inspection process is executed in the first inspection mode in which the detection accuracy is set to the lowest among the inspection modes (detection accuracy: low), and in the case of the third determination value, the detection accuracy is in each inspection mode. The inspection process is executed in the third inspection mode that is set to the highest one of the above. In the case of the second determination value, the inspection process is performed in the second inspection mode set to the detection accuracy between the detection accuracy in the first inspection mode and the detection accuracy in the second inspection mode. In the present embodiment, a total of three determination values from the first determination value to the third determination value are set, and a total of three inspection modes from the first inspection mode to the third inspection mode are set accordingly. However, the present invention is not limited to this, and it is also possible to adopt a configuration in which two or four or more determination values are set and two or four or more inspection modes are provided according to this. Also in this configuration, any configuration may be used as long as the detection accuracy is increased step by step.

  Further, the tolerance of peeling determination based on the difference Δa in the peeling detection step is also different in each inspection mode. The smaller the cumulative load, the larger the allowable error, and the larger the cumulative load, the relatively larger the allowable error. It is getting smaller. Specifically, in each inspection mode, as a difference Δa that is likely to cause a failure (separation) in each inspection mode (a value that is considered to be extremely high if there is more than this) Failure reference values Bf1 to Bf3 are determined in advance based on test results and the like. The threshold Th1 in the first inspection mode is set to a value larger than the failure reference value Bf1 because the detection accuracy is low in this mode, and the difference D1 (= Th1−Bf1) between Th1 and Bf1 is in each inspection mode. Is the largest. Thereby, a certain amount of error is allowed, and false detection detected as a failure even though no failure actually occurs is reduced. On the other hand, in the third inspection mode, the threshold value Th3 is set as close as possible to the failure reference value Bf3, and the difference D3 (= Th3-Bf3) between Th3 and Bf3 is the smallest in each inspection mode. It has become. That is, in the third inspection mode, the allowable error is set to be the smallest among the modes. Thereby, the detection accuracy is further improved. In the second inspection mode, the difference D2 (= Th2−Bf2) between the threshold Th2 and the failure reference value Bf2 is set to a value between the difference D1 in the first inspection mode and the difference D3 in the third inspection mode. Yes.

  FIG. 10 is a table showing a specific example of the inspection processing in the present embodiment. FIG. 11 shows waveforms of the first back electromotive force signal Sc1 (during single inspection / single driving) and the second back electromotive force signal Sc2 (during assist inspection / assist driving) output from the vibration detection circuit 38. It is the shown graph. In the figure, the solid line shows the waveform when the inspection target nozzle 23a is driven alone, and the broken line shows the waveform at the time of assist driving in the first inspection mode. In the figure, the alternate long and short dash line indicates the waveform during assist driving in the second inspection mode, and the alternate long and two short dashes line indicates the waveform during assist driving in the third inspection mode. In addition, about the graph of FIG. 11, the substantially same result is obtained in each example of Examples A to E in FIG.

  In the example indicated by A in FIG. 10, the inspection drive pulse Pd shown in FIG. 4 is used for both the inspection target nozzle 23a and the assist nozzle 23b. This inspection drive pulse Pd is the drive pulse that can cause the largest vibration in the ink in the pressure chamber 20 as compared with other drive pulses described later, and the ink droplet ejected from the nozzle 23 is the largest. In addition, the number of assist nozzles 23b that are driven together with the inspection target nozzles 23a is two in each inspection mode (on both sides of the inspection target nozzles 23a). In Example A, the drive voltage Vd (see FIG. 4) of the test drive pulse Pd applied to the piezoelectric element 18a corresponding to the test target nozzle 23a is different in each test mode. Specifically, in the first inspection mode, the drive voltage Vd is set to the lowest value (small) in each inspection mode, and in the third inspection mode, the drive voltage Vd is set to the highest value (large) in each inspection mode. In the second inspection mode, the drive voltage Vd is set to a value (medium) between the drive voltage Vd in the first inspection mode and the drive voltage Vd in the third inspection mode.

  Thus, in Example A, the drive voltage Vd of the test drive pulse Pd is increased stepwise from the first test mode to the third test mode. Here, when peeling occurs at least one of the upper and lower sides of the partition wall 13 that defines the pressure chamber 20 of the inspection target nozzle 23a, the partition wall 13 is easily bent. For this reason, in the single inspection in which only the inspection target nozzle 23a is driven, the amplitude or the like of the first counter electromotive force signal Sc1 hardly changes regardless of the level of the driving voltage Vd of the inspection driving pulse Pd. On the other hand, in the assist inspection, since the pressure in the pressure chamber 20 of the inspection target nozzle 23a is difficult to escape by driving the assist nozzle 23b, the amplitude of the second counter electromotive force signal Sc2 is the driving of the inspection driving pulse Pd. The first inspection mode, the second inspection mode, and the third inspection mode increase in order according to the voltage Vd. As a result, the difference Δ between the first counter electromotive force signal Sc1 and the second counter electromotive force signal Sc2 also increases in the order of the first inspection mode, the second inspection mode, and the third inspection mode. For this reason, the detection accuracy of failure (peeling) is also improved in the order of the first inspection mode, the second inspection mode, and the third inspection mode.

  When the accumulated load is the first determination value, the inspection process is executed in the first inspection mode in which the detection accuracy is set to the lowest among the inspection modes. In the case of the third determination value, the inspection process is executed in the third inspection mode in which the detection accuracy is set highest among the inspection modes. In the case of the second determination value, the inspection process is performed in the second inspection mode set to a detection accuracy intermediate between the detection accuracy in the first inspection mode and the detection accuracy in the third inspection mode. In Example A, the drive voltage Vd of the test drive pulse Pd applied to the piezoelectric element 18b corresponding to the assist nozzle 23b is constant (for example, medium) in each test mode.

  In the first inspection mode, it is possible to efficiently detect peeling while suppressing wasteful consumption of ink. That is, the smaller the cumulative load, the less the possibility of peeling, so that the detection accuracy can be kept low, so that the amount of ink ejected from each nozzle 23a, 23b can be reduced. Thereby, the amount of ink consumed in the inspection process can be reduced. Further, as described above, since a certain amount of error is allowed for the difference Δ between the first back electromotive force signal Sc1 and the second back electromotive force signal Sc2, erroneous detection is suppressed. On the other hand, the greater the cumulative load, the greater the possibility that peeling has occurred. For this reason, in the second inspection mode and the third inspection mode, the driving voltage Vd of the inspection driving pulse Pd is sequentially increased as compared with the case of the first inspection mode, so that the detection accuracy of peeling can be improved.

  The example indicated by B in FIG. 10 is different from Example A in that the inspection drive pulse is different in each inspection mode. FIG. 12 is a waveform diagram showing an example of the micro-vibration drive pulse Pv used as the inspection drive pulse, and FIG. 13 is a waveform diagram showing an example of the small dot drive pulse Ps also used as the inspection drive pulse. . In the first inspection mode of Example B, the fine vibration drive pulse Pv shown in FIG. 12 is used as an inspection drive pulse for the inspection target nozzle 23a. The fine vibration drive pulse Pv includes a preliminary expansion element p21, an expansion hold element p22, and a return element p23. The preliminary expansion element p21 is a waveform element in which the potential changes from the reference potential VB to the expansion potential VLv toward the ground potential GND. The expansion hold element p22 is a waveform element that maintains the expansion potential VLv, which is the terminal potential of the preliminary expansion element p21, for a predetermined time. The return element p23 is a waveform element whose potential changes to the positive side from the expansion potential VLv to the reference potential VB. The fine vibration drive pulse Pv is a drive pulse in which a waveform and a drive voltage are set so that pressure vibration is generated in the ink in the pressure chamber 20 to such an extent that ink is not ejected from the nozzles 23. That is, the fine vibration drive pulse Pv is the drive pulse in which the vibration generated in the ink in the pressure chamber 20 is the smallest among the drive pulses for inspection.

  In the second inspection mode of Example B, the small dot drive pulse Ps shown in FIG. 13 is used as an inspection drive pulse for the inspection target nozzle 23a. The small dot drive pulse Ps includes a preliminary expansion element p31, an expansion hold element p32, a contraction element p33, a contraction hold element p34, a front stage expansion element p35, an intermediate hold element p36, and a rear stage expansion element p37. Become. The preliminary expansion element p31 is a waveform element in which the potential changes from the reference potential VB to the expansion potential VLs toward the ground potential GND. The expansion hold element p32 is a waveform element that maintains the expansion potential VLs that is the terminal potential of the preliminary expansion element p31 for a certain period of time. The contraction element p33 is a waveform element in which the potential changes from the expansion potential VLs over the reference potential VB to the contraction potential VHs with a relatively steep slope on the positive side. The pre-stage expansion element p35 is a waveform element that changes in potential from the contraction potential VHs to the intermediate potential VM (VB <VM <VHs) toward the ground potential GND. The intermediate hold element p36 is a waveform element that maintains the intermediate potential VM, which is the terminal potential of the upstream expansion element p35, for a certain period of time. The post-stage expansion element p37 is a waveform element that changes in potential from the intermediate potential VM to the reference potential VB toward the ground potential GND. The small dot drive pulse Ps is a drive pulse set such that the amount of ink ejected from the nozzles 23 is smaller than that in the case of the inspection drive pulse Pd. That is, the small dot drive pulse Ps is a drive pulse that is set such that the vibration generated in the ink in the pressure chamber 20 is larger than that of the fine vibration drive pulse Pv and smaller than that of the inspection drive pulse Pd. is there.

  In Example B, the fine vibration drive pulse Pv is used for any assist nozzle 23b. Further, the number of assist nozzles 23b that are driven together with the inspection target nozzles 23a is two (both adjacent to the inspection target nozzles 23a) in each inspection mode, as in Example A. In this example B, as the inspection drive pulse for the inspection target nozzle 23a, the fine vibration drive pulse Pv in the first inspection mode, the small dot drive pulse Ps in the second inspection mode, and the inspection drive pulse Pd in the second inspection mode. However, by using each, the detection accuracy can be increased step by step. In Example B as well, as in Example A, it is possible to efficiently detect peeling according to the accumulated load while suppressing wasteful ink consumption.

  In the example indicated by C in FIG. 10, the inspection drive pulse Pd having a constant drive voltage Vd is used for the inspection target nozzle 23a in any inspection mode. Further, a fine vibration drive pulse Pv is used for the assist nozzle 23b. The number of assist nozzles 23b that are driven together with the inspection target nozzles 23a is two in each inspection mode (on both sides of the inspection target nozzles 23a). In this example C, the driving voltage Vdv (see FIG. 12) of the micro-vibration driving pulse Pv applied to the piezoelectric element 18b corresponding to the assist nozzle 23b is different in each inspection mode. Specifically, in the first inspection mode, the drive voltage Vdv is set to the lowest value (small) in each inspection mode, and in the third inspection mode, the drive voltage Vdv is set to the highest value (large) in each inspection mode. In the second inspection mode, the drive voltage Vdv is set to a value (medium) between the value of the drive voltage Vdv in the first inspection mode and the value of the drive voltage Vdv in the third inspection mode. As described above, the drive voltage Vdv of the fine vibration drive pulse Pv is gradually increased from the first inspection mode to the third inspection mode, so that the partition wall 13 of the pressure chamber 20 of the inspection target nozzle 23a is deformed during the assist inspection. Suppressing (bending) is suppressed, and the detection accuracy is also increased stepwise. In Example C as well, as in Example A, it is possible to efficiently detect peeling according to the accumulated load while suppressing wasteful ink consumption.

  In the example indicated by D in FIG. 10, the inspection drive pulse Pd is used for the inspection target nozzle 23a in any inspection mode, and the inspection drive pulse Pd is used for the assist nozzle 23b. In addition, the number of assist nozzles 23b that are driven together with the inspection target nozzles 23a is two in each inspection mode (on both sides of the inspection target nozzles 23a). In this example D, the drive voltage Vd of the test drive pulse Pd for the test target nozzle 23a and the test drive pulse Pd for the assist nozzle 23b are different in each test mode. Specifically, in the first inspection mode, the drive voltage Vd of the inspection drive pulse Pd for the inspection target nozzle 23a and the drive voltage Vd of the inspection drive pulse Pd for the assist nozzle 23b are the lowest in each inspection mode. Value (small) is set. In the third inspection mode, the drive voltage Vd of the inspection drive pulse Pd for the inspection target nozzle 23a and the drive voltage Vd of the inspection drive pulse Pd for the assist nozzle 23b are the highest values (large) in each inspection mode. ). In the second inspection mode, the drive voltage Vd of the inspection drive pulse Pd for the inspection target nozzle 23a and the drive voltage Vd of the inspection drive pulse Pd for the assist nozzle 23b are the drive voltage Vd in the first inspection mode. And a value (medium) between the value of and the value of the drive voltage Vd in the third inspection mode. In this example D, in response to the drive voltage Vd of the inspection drive pulse Pd for the inspection target nozzle 23a being increased stepwise from the first inspection mode to the third inspection mode, the inspection drive pulse for the assist nozzle 23b. Since the drive voltage Vd of Pd is increased stepwise from the first inspection mode to the third inspection mode, the bending of the partition wall 13 of the pressure chamber 20 of the inspection target nozzle 23a is more reliably suppressed. Therefore, it is possible to detect the peeling more accurately.

  In the example indicated by E in FIG. 10, in any inspection mode, the inspection drive pulse Pd is used for the inspection target nozzle 23a, and the inspection drive pulse Pd is also used for the assist nozzle 23b. Further, the number of assist nozzles 23b driven together with the inspection target nozzle 23a is two in the first inspection mode and the second inspection mode (two in total of the nozzles 23b on both sides of the inspection target nozzle 23a), and is four in the third inspection mode. (A total of four nozzles 23b adjacent to both sides of the inspection target nozzle 23a and nozzles 23b adjacent to these nozzles 23b). Then, regarding the drive voltage Vd of the inspection drive pulse Pd for the inspection target nozzle 23a and the inspection drive pulse Pd for the assist nozzle 23b, the lowest value (small) is set in each inspection mode in the first inspection mode. In the second inspection mode and the third inspection mode, the highest value (large) is set. In this example E, in the second inspection mode, the driving voltage Vd of the inspection driving pulse Pd for the inspection target nozzle 23a and the inspection driving pulse Pd for the assist nozzle 23b is increased compared to the case of the first inspection mode. As a result, the detection accuracy is improved. In the third inspection mode, the number of assist nozzles 23b is increased from 2 in the second inspection mode to 4 in the second inspection mode, so that the detection accuracy of peeling is increased. As described above, also in Example E, it is possible to detect peeling more accurately while suppressing erroneous detection according to the accumulated load.

  In this way, if the drive voltage of the test drive pulse, the waveform of the test drive pulse, or the number of the assist nozzles 23b are changed according to the accumulated load, or a combination of these, failure ( Detection of peeling can be performed efficiently. In other words, the smaller the cumulative load, the less the possibility of peeling, so the pressure generated in the pressure chamber 20 is kept low to reduce the amount of ink ejected from the nozzles 23 during inspection, or not to eject it. It is possible to suppress wasteful consumption of ink. On the other hand, the greater the cumulative load, the greater the possibility that peeling has occurred. For this reason, the drive voltage of the test drive pulse is increased, or the waveform of the test drive pulse itself is changed to one having a higher driving force (a vibration that is generated in the ink in the pressure chamber 20 is larger), By increasing the number of assist nozzles 23b or combining them, it is possible to improve the detection accuracy of peeling. In addition, since the possibility of peeling is lower as the cumulative load is smaller, the detection error in the peeling detection step is set to be relatively large, so that erroneous detection is suppressed. On the other hand, since the possibility that peeling has occurred increases as the cumulative load increases, it is possible to improve the detection accuracy of peeling by setting the tolerance for peeling determination in the peeling detection step to be relatively small.

  In addition, by configuring the inspection process to be performed when the cumulative load related to the occurrence of peeling exceeds a predetermined determination value, the inspection is performed at an initial stage where the possibility of occurrence of peeling is relatively low. Processing can be prevented from being executed, and the processing time can be reduced accordingly. In addition, when ink is ejected from the nozzles 23 in the inspection process, wasteful consumption of ink can be reduced. In addition, when peeling is detected in the peeling detection process, a warning is given to the user so that the user can quickly grasp that the peeling has occurred, so that more prompt repairs and replacements are possible. Is possible.

  This is not limited to the case where the usage time is the cumulative load, and the same applies to the case where the cumulative value of the number of discharges is the cumulative load. In short, as the cumulative load is larger, the driving voltage of the inspection driving pulse is increased, the waveform of the inspection driving pulse itself is changed to a higher driving force, the number of assist nozzles 23b is increased, or a combination thereof. As a result, it is possible to detect peeling more accurately while suppressing wasteful consumption of ink and erroneous detection.

  In the above embodiment, the configuration in which the elastic film 16 and the nozzle plate 15 are joined to the pressure chamber substrate 14, that is, the upper and lower sides of the partition wall 13 of the pressure chamber 20, respectively, is exemplified. The present invention can be similarly applied to a configuration in which members different from those in the above embodiment are joined to the upper and lower sides of the 20 partition walls 13.

  Furthermore, although the piezoelectric element 18 was illustrated as an actuator in the said embodiment, it is not restricted to this, For example, various actuators, such as a heat generating element and an electrostatic actuator, are employable.

  The present invention is not limited to a printer, as long as it is a liquid ejecting apparatus having a configuration in which liquid is ejected from a nozzle by pressure vibration generated in the liquid in the pressure chamber by driving an actuator. The present invention can also be applied to various ink jet recording apparatuses and liquid ejection apparatuses other than the recording apparatus, such as a display manufacturing apparatus, an electrode manufacturing apparatus, and a chip manufacturing apparatus.

DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Recording head, 3 ... Ink cartridge, 4 ... Carriage, 5 ... Platen, 6 ... Recording paper, 7 ... Carriage moving mechanism, 8 ... Paper feed mechanism, 9 ... Guide rod, 10 ... Linear encoder, 12 DESCRIPTION OF SYMBOLS ... Adhesive, 13 ... Partition, 14 ... Pressure chamber board, 15 ... Nozzle plate, 16 ... Elastic film, 17 ... Insulating film, 18 ... Piezoelectric element, 19 ... Protection board, 20 ... Pressure chamber, 21 ... Communication part, 22 Ink supply path, 23 ... Nozzle, 24 ... Lower electrode, 25 ... Piezoelectric body, 26 ... Upper electrode, 27 ... Reservoir, 30 ... Head controller, 31 ... Printer controller, 32 ... Print engine, 33 ... External interface, 34 ... Memory, 35 ... CPU, 36 ... Drive signal generation circuit, 37 ... Pulse selection switch, 38 ... Vibration detection circuit, 39 ... Switch, 40 ... Detection Anti-vessel

Claims (7)

A plurality of nozzles arranged in parallel, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed with a partition wall therebetween, and an actuator for generating pressure vibration in the liquid in the pressure chamber, and by driving the actuator a liquid discharge head for discharging liquid from the nozzle, there is provided an inspection method of a liquid discharge head comprising a detecting circuit, a detecting vibration of the liquid in the pressure chamber caused by the driving of the actuator,
A first driving step of driving a first actuator corresponding to the nozzle to be inspected;
A first detection step of detecting a vibration generated in the liquid in the pressure chamber corresponding to the nozzle to be tested by the driving of the first driving step,
A second driving step of driving both the first actuator and a second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle;
A second detection step of detecting vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by driving in the second driving step;
A peeling detection step for detecting peeling of a member bonded to the partition wall based on a difference between a detection result in the first detection step and a detection result in the second detection step;
When the cumulative load related to the occurrence of peeling exceeds a predetermined determination value ,
The smaller the cumulative load is, the relatively large tolerance for determination of peeling in the peeling detection step is,
An inspection method for a liquid ejection head, wherein an allowable error in determination of peeling in the peeling detection step is relatively small as the cumulative load is large . A plurality of nozzles arranged in parallel, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed with a partition wall therebetween, and an actuator for generating pressure vibration in the liquid in the pressure chamber, and by driving the actuator An inspection method for a liquid discharge head comprising: a liquid discharge head that discharges liquid from the nozzle; and a detection circuit that detects vibration of the liquid in the pressure chamber generated by driving the actuator,
A first driving step of driving a first actuator corresponding to the nozzle to be inspected;
A first detection step of detecting vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by driving in the first driving step;
A second driving step of driving both the first actuator and a second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle;
A second detection step of detecting vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle by driving in the second driving step;
A peeling detection step for detecting peeling of a member bonded to the partition wall based on a difference between a detection result in the first detection step and a detection result in the second detection step;
When the cumulative load related to the occurrence of peeling exceeds a predetermined determination value,
The higher the cumulative load is large, the second first second inspection method of the liquid discharge head you characterized by increasing the number of actuators to be driven with actuator nozzle to be tested in the driving step. As the cumulative load is smaller, the tolerance for determination of separation in the separation detection step is relatively large, and as the cumulative load is larger, the tolerance for determination of separation in the separation detection step is relatively small. The method for inspecting a liquid discharge head according to claim 2. 4. The method for inspecting a liquid ejection head according to claim 1 , further comprising a warning step of giving a warning to a user when peeling is detected in the peeling detection step. 5. . 5. The liquid according to claim 1 , wherein when the actuator is driven in the first driving step and the second driving step, liquid is ejected from a corresponding nozzle. 6. Inspection method for liquid discharge heads. A plurality of nozzles arranged in parallel, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed with a partition wall therebetween, and a liquid ejection head having an actuator that generates pressure vibration in the liquid in the pressure chamber;
A detection circuit for detecting the vibration of the liquid in the pressure chamber generated by driving the actuator;
A control circuit for controlling the ejection of liquid from the nozzle by driving the actuator;
A liquid ejection device comprising:
The control circuit includes:
Driving the first actuator corresponding to the inspection target nozzle to detect the vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle as a first detection result;
The first actuator and the second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle are driven together to cause vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle. Detected as the detection result of 2,
Based on the difference between the first detection result and the second detection result, an inspection process for detecting the separation of the member joined to the partition wall is performed with a determination value in which the cumulative load related to the occurrence of the separation is predetermined. Execute if exceeded,
The liquid ejecting apparatus according to claim 1 , wherein the tolerance for separation determination is relatively large as the cumulative load is small, and the tolerance for separation determination is relatively small as the cumulative load is large . A plurality of nozzles arranged in parallel, a substrate in which a plurality of pressure chambers communicating with each nozzle are formed with a partition wall therebetween, and a liquid ejection head having an actuator that generates pressure vibration in the liquid in the pressure chamber;
A detection circuit for detecting the vibration of the liquid in the pressure chamber generated by driving the actuator;
A control circuit for controlling the ejection of liquid from the nozzle by driving the actuator;
A liquid ejection device comprising:
The control circuit includes:
Driving the first actuator corresponding to the inspection target nozzle to detect the vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle as a first detection result;
The first actuator and the second actuator corresponding to at least one of the nozzles adjacent to the inspection target nozzle are driven together to cause vibration generated in the liquid in the pressure chamber corresponding to the inspection target nozzle. Detected as the detection result of 2,
Based on the difference between the first detection result and the second detection result, an inspection process for detecting the separation of the member joined to the partition wall is performed with a determination value in which the cumulative load related to the occurrence of the separation is predetermined. Execute if exceeded,
The liquid ejecting apparatus according to claim 1, wherein the number of second actuators driven together with the first actuators of the nozzles to be inspected is increased as the cumulative load increases .

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