Liquid dispensing device

Abstract

To suppress consumption of an unnecessary liquid after test pattern formation processing has been performed.SOLUTION: A control part of a printer receives a test pattern recording command signal for forming a test pattern on recording paper, executes test pattern printing processing, and determines whether to execute recovery processing on the basis of a user determination signal according to the test pattern formed on the recording paper. The control part performs inspection processing after an abnormal state occurs in a printer after the number of cumulative printed sheets reaches a predetermined number of sheets after a predetermined time, and executes automatic recovery processing when it is determined that the number of abnormal nozzles is equal to or larger than a threshold. The control part does not execute the automatic recovery processing until at least a predetermined condition is satisfied, after the test pattern printing processing has been performed.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device that ejects liquid from a nozzle. [Background technology]

[0002] Patent document 1 describes an image recording device that includes an inspection unit that periodically inspects the recording elements provided in the print head for abnormalities, a judgment unit that determines whether the recording elements can be used based on the inspection results of the inspection unit, and a completion unit that disables recording elements that are determined to be unusable by the judgment unit and complements image defects caused by the disabled recording elements. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-49631 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, some liquid ejection devices that eject liquid from multiple nozzles to form images on an ejection-receiving medium automatically execute a recovery process to discharge liquid from the nozzles and restore the ejection performance of abnormal nozzles, depending on the number of nozzles determined to be abnormal in ejection performance through periodic nozzle ejection tests. Some liquid ejection devices form a test pattern on the ejection-receiving medium in response to a user inputting, into an input unit, an instruction to form a test pattern on the ejection-receiving medium to verify whether or not an abnormality has occurred in the nozzles. The liquid ejection device then executes the recovery process when the user checks the test pattern formed on the ejection-receiving medium and inputs a recovery execution instruction from the user into the input unit.

[0005] In the above-described liquid ejection device, if the recovery process is automatically performed in response to a periodic ejection inspection after the user has decided whether to perform the recovery process, liquid will be consumed unnecessarily. In other words, if the recovery process is performed at the user's discretion, the nozzles are in a recovered state, and if the recovery process is not performed at the user's discretion, the user is in a state where there is no need to recover the nozzles. Therefore, if the automatic recovery process is performed after the user has decided whether to perform the recovery process, a recovery process that the user does not want will be performed, resulting in unnecessarily consuming liquid.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a liquid ejection apparatus that is capable of suppressing unnecessary consumption of liquid after a test pattern formation process has been performed. [Means for solving the problem]

[0007] In a first aspect, the liquid ejection device of the present invention comprises a liquid ejection head having a plurality of nozzles for ejecting liquid, a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for testing to check whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means that performs recovery operation to discharge liquid from the nozzle, an input unit for a user to input predetermined instructions, and a control unit. When a user inputs a test pattern formation instruction into the input unit to form a test pattern on the ejection-receiving medium to confirm whether the nozzle is the abnormal nozzle, the control unit executes a test pattern formation process to form the test pattern on the ejection-receiving medium by ejecting liquid from the multiple nozzles, and when a user inputs a user judgment instruction into the input unit as to whether or not to perform the recovery operation corresponding to the test pattern formed on the ejection-receiving medium by the test pattern formation process, the control unit determines whether or not to cause the recovery means to perform the recovery operation based on the user judgment instruction, causes the test drive to be performed after a first condition is satisfied, and if it is determined that the number of abnormal nozzles is equal to or greater than a threshold based on the judgment signal output from the signal output unit during the test drive, causes the recovery means to execute an automatic recovery process to perform the recovery operation, and after the test pattern formation process has been performed, the control unit does not execute the automatic recovery process until at least a second condition different from the first condition is satisfied, regardless of whether or not the recovery operation based on the user judgment instruction has been performed. In a second aspect, the liquid ejection device of the present invention comprises a liquid ejection head having a plurality of nozzles for ejecting liquid, a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to check whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means that performs recovery operation to discharge liquid from the nozzle, an input unit for a user to input predetermined instructions, and a control unit. When a user inputs a test pattern formation instruction into the input unit to form a test pattern on the ejection-receiving medium to confirm whether the nozzle is the abnormal nozzle, the control unit executes a test pattern formation process to form the test pattern on the ejection-receiving medium by ejecting liquid from the multiple nozzles, and when a user inputs a user judgment instruction into the input unit as to whether or not to perform the recovery operation corresponding to the test pattern formed on the ejection-receiving medium by the test pattern formation process, the control unit determines whether or not to cause the recovery means to perform the recovery operation based on the user judgment instruction, causes the test drive to be performed after a first condition is satisfied, and if it is determined that the number of abnormal nozzles is equal to or greater than a threshold based on the judgment signal output from the signal output unit during the test drive, causes the recovery means to execute an automatic recovery process to perform the recovery operation, and after the test pattern formation process has been performed, the control unit does not execute the automatic recovery process until at least a second condition different from the first condition is satisfied, regardless of whether or not the recovery operation based on the user judgment instruction has been performed. The device further includes a clock unit that outputs a time signal indicating a time, and the first condition is that the time signal indicating a predetermined time is output from the clock unit. Ta That is the thing. In a third aspect, the liquid ejection device of the present invention comprises a liquid ejection head having a plurality of nozzles for ejecting liquid, a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to check whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means that performs recovery operation to discharge liquid from the nozzle, an input unit for a user to input predetermined instructions, and a control unit. When a user inputs a test pattern formation instruction into the input unit to form a test pattern on the ejection-receiving medium to confirm whether the nozzle is the abnormal nozzle, the control unit executes a test pattern formation process to form the test pattern on the ejection-receiving medium by ejecting liquid from the multiple nozzles, and when a user inputs a user judgment instruction into the input unit as to whether or not to perform the recovery operation corresponding to the test pattern formed on the ejection-receiving medium by the test pattern formation process, the control unit determines whether or not to cause the recovery means to perform the recovery operation based on the user judgment instruction, causes the test drive to be performed after a first condition is satisfied, and if it is determined that the number of abnormal nozzles is equal to or greater than a threshold based on the judgment signal output from the signal output unit during the test drive, causes the recovery means to execute an automatic recovery process to perform the recovery operation, and after the test pattern formation process has been performed, the control unit does not execute the automatic recovery process until at least a second condition different from the first condition is satisfied, regardless of whether or not the recovery operation based on the user judgment instruction has been performed. The apparatus further includes a memory unit, and the control unit stores in the memory unit the cumulative number of sheets of ejection medium on which an image is formed by an ejection operation that causes the liquid ejection head to eject liquid from the multiple nozzles toward the ejection medium, and the first condition is that the cumulative number of sheets stored in the memory unit reaches a predetermined number. In a fourth aspect, the liquid ejection device of the present invention comprises a liquid ejection head having a plurality of nozzles for ejecting liquid, a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to check whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means that performs recovery operation to discharge liquid from the nozzle, an input unit for a user to input predetermined instructions, and a control unit. The control unit, when a user inputs to the input unit a test pattern formation instruction for forming a test pattern on a discharge-receiving medium to confirm whether the nozzle is the abnormal nozzle, executes a test pattern formation process for forming the test pattern on the discharge-receiving medium by ejecting liquid from the plurality of nozzles, and when a user inputs to the input unit a user determination instruction as to whether or not to execute the recovery operation corresponding to the test pattern formed on the discharge-receiving medium by the test pattern formation process, determines whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction, causes the control unit to perform the test drive after a first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold based on the determination signal output from the signal output unit during the test drive, causes the control unit to execute an automatic recovery process for causing the recovery means to execute the recovery operation, and does not execute the automatic recovery process until at least a second condition is satisfied after the test pattern formation process has been performed. The liquid discharge device further includes an apparatus abnormality output unit that outputs an apparatus abnormality signal when an apparatus abnormality other than the abnormal nozzle occurs in the liquid discharge device, and the first condition is Ta That is the thing. In a fifth aspect, the liquid ejection device of the present invention comprises a liquid ejection head having a plurality of nozzles for ejecting liquid, a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to check whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means that performs recovery operation to discharge liquid from the nozzle, an input unit for a user to input predetermined instructions, and a control unit. When a user inputs a test pattern formation instruction into the input unit to form a test pattern on the ejection-receiving medium to confirm whether the nozzle is the abnormal nozzle, the control unit executes a test pattern formation process to form the test pattern on the ejection-receiving medium by ejecting liquid from the multiple nozzles, and when a user inputs a user judgment instruction into the input unit as to whether or not to perform the recovery operation corresponding to the test pattern formed on the ejection-receiving medium by the test pattern formation process, the control unit determines whether or not to cause the recovery means to perform the recovery operation based on the user judgment instruction, causes the test drive to be performed after a first condition is satisfied, and if it is determined that the number of abnormal nozzles is equal to or greater than a threshold based on the judgment signal output from the signal output unit during the test drive, causes the recovery means to execute an automatic recovery process to perform the recovery operation, and does not execute the automatic recovery process after the test pattern formation process has been performed until at least a second condition is satisfied. Furthermore, when performing an ejection operation in which the liquid ejection head ejects liquid from the multiple nozzles toward the ejection medium, if the number of abnormal nozzles based on the judgment signal output from the signal output unit during the inspection drive performed after the first condition is satisfied is equal to or greater than a threshold value, the control unit executes the automatic recovery process prior to the ejection operation. In a sixth aspect, the liquid ejection device of the present invention comprises a liquid ejection head having a plurality of nozzles for ejecting liquid, a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for testing to check whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means that performs recovery operation to discharge liquid from the nozzle, an input unit for a user to input predetermined instructions, and a control unit. The control unit, when a user inputs a test pattern formation instruction to the input unit to form a test pattern on the ejection receiving medium to determine whether the nozzle is the abnormal nozzle, executes a test pattern formation process to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles, and when a user inputs a user determination instruction to the input unit to determine whether to perform the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determines whether to cause the recovery unit to perform the recovery operation based on the user determination instruction, causes the test drive to be performed after a first condition is satisfied, and if it is determined that the number of abnormal nozzles is equal to or greater than a threshold based on the determination signal output from the signal output unit during the test drive, causes the recovery unit to perform an automatic recovery process to perform the recovery operation, and does not execute the automatic recovery process after the test pattern formation process has been performed until at least a second condition is satisfied. Furthermore, the control unit, when the test pattern formation process has been performed, does not execute the test drive after the first condition is satisfied until at least the second condition is satisfied. In a seventh aspect, the liquid ejection device of the present invention comprises a liquid ejection head having a plurality of nozzles for ejecting liquid, a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to check whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means that performs recovery operation to discharge liquid from the nozzle, an input unit for a user to input predetermined instructions, and a control unit. The control unit, when a user inputs a test pattern formation instruction to the input unit to form a test pattern on the ejection receiving medium to check whether the nozzle is the abnormal nozzle, executes a test pattern formation process to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles, and when the user inputs a user determination instruction to the input unit as to whether to perform the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determines whether to cause the recovery unit to perform the recovery operation based on the user determination instruction, causes the control unit to perform the test drive after a first condition is satisfied, and if it is determined that the number of abnormal nozzles is equal to or greater than a threshold based on the determination signal output from the signal output unit during the test drive, causes the control unit to perform an automatic recovery process to cause the recovery unit to perform the recovery operation, and does not execute the automatic recovery process after the test pattern formation process has been performed until a second condition is satisfied, wherein the second condition is that the automatic recovery process is not executed a predetermined number of times after the test pattern formation process has been performed. In an eighth aspect, the liquid ejection device of the present invention comprises a liquid ejection head having a plurality of nozzles for ejecting liquid, a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for testing to check whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means that performs recovery operation to discharge liquid from the nozzle, an input unit for a user to input predetermined instructions, and a control unit. The control unit, when a user inputs a test pattern formation instruction to the input unit to form a test pattern on the ejection receiving medium to check whether the nozzle is the abnormal nozzle, executes a test pattern formation process to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles, and when the user inputs a user determination instruction to the input unit as to whether to perform the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determines whether to cause the recovery unit to perform the recovery operation based on the user determination instruction, causes the control unit to perform the test drive after a first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold based on the determination signal output from the signal output unit during the test drive, causes the control unit to perform an automatic recovery process to cause the recovery unit to perform the recovery operation, and does not execute the automatic recovery process after the test pattern formation process has been performed until at least a second condition is satisfied, which is that a predetermined period of time has elapsed since the test pattern formation process was performed. In a ninth aspect, the liquid ejection device of the present invention comprises a liquid ejection head having a plurality of nozzles for ejecting liquid, a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to check whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid, recovery means that performs recovery operation to discharge liquid from the nozzle, an input unit for a user to input predetermined instructions, and a control unit. When a user inputs a test pattern formation instruction into the input unit to form a test pattern on the ejection-receiving medium to confirm whether the nozzle is the abnormal nozzle, the control unit executes a test pattern formation process to form the test pattern on the ejection-receiving medium by ejecting liquid from the multiple nozzles, and when a user inputs a user judgment instruction into the input unit as to whether or not to perform the recovery operation corresponding to the test pattern formed on the ejection-receiving medium by the test pattern formation process, the control unit determines whether or not to cause the recovery means to perform the recovery operation based on the user judgment instruction, causes the test drive to be performed after a first condition is satisfied, and if it is determined that the number of abnormal nozzles is equal to or greater than a threshold based on the judgment signal output from the signal output unit during the test drive, causes the recovery means to execute an automatic recovery process to perform the recovery operation, and does not execute the automatic recovery process after the test pattern formation process has been performed until at least a second condition is satisfied. The control unit further includes a memory unit, and when the user inputs the test pattern formation instruction to the input unit, the control unit performs the inspection drive before or after executing the test pattern formation process, and stores the abnormal nozzles based on the judgment signal output from the signal output unit during the inspection drive as abnormal nozzles for the test pattern in the memory unit, and the second condition is that the number of abnormal nozzles based on the judgment signal output from the signal output unit during the inspection drive performed after the first condition is satisfied is greater than the number of abnormal nozzles for the test pattern when the recovery means is not caused to perform the recovery operation based on the user judgment instruction. [Effects of the Invention]

[0008] According to the liquid ejection device of the present invention, regardless of whether or not a recovery operation is performed based on the user's decision in response to the results of the test pattern formed on the ejection receiving medium by the test pattern formation process, after the test pattern formation process has been performed, the automatic recovery process is not executed until the second condition is satisfied, thereby making it possible to reduce unnecessary liquid consumption. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a printer according to a first embodiment of the present invention. [Figure 2] 10A and 10B are diagrams for explaining detection electrodes arranged in a cap, and the connection relationship between the detection electrodes and a high-voltage power supply circuit and a signal processing circuit. [Figure 3] FIG. 1(a) is a diagram showing the change in voltage value of the detection electrode when ink is ejected from the nozzle, and FIG. 1(b) is a diagram showing the change in voltage value of the detection electrode when ink is not ejected from the nozzle. [Figure 4] FIG. 2 is a block diagram showing the electrical configuration of the printer. [Figure 5] 10 is a flowchart showing an operation when an abnormality in the printer is detected. [Figure 6] 10 is a flowchart showing the operation of the printer when it is on standby. [Figure 7] 10 is a flowchart showing the operation of the printer when printing a test pattern. [Figure 8] 10 is a flowchart showing the operation of the printer during normal printing. [Figure 9] 10 is a flowchart showing an operation when the inhibition of the recovery process of the printer is lifted. [Figure 10] 10 is a flowchart showing standby operation of a printer according to a second embodiment of the present invention. [Figure 11] 10 is a flowchart showing an operation when the inhibition of recovery processing of a printer according to a second embodiment of the present invention is lifted. [Figure 12]10 is a flowchart showing an operation when the inhibition of recovery processing of a printer according to a third embodiment of the present invention is lifted. [Figure 13] 10 is a flowchart showing standby operation of a printer according to a fourth embodiment of the present invention. [Figure 14] 10 is a flowchart showing the operation of a printer according to a fourth embodiment of the present invention during normal printing. [Figure 15] 10 is a flowchart showing an operation when the inhibition of recovery processing of a printer according to a fourth embodiment of the present invention is lifted. [Figure 16] 10 is a flowchart showing the operation of a printer according to a fifth embodiment of the present invention when printing a test pattern. [Figure 17] 13 is a flowchart showing an operation when the inhibition of recovery processing of a printer according to a fifth embodiment of the present invention is lifted. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present invention will now be described.

[0011] <Overall printer configuration> As shown in FIG. 1, the printer 1 (the "liquid ejection device" of the present invention) according to the first embodiment includes a carriage 2, a subtank 3, an inkjet head 4 (the "liquid ejection head" of the present invention), a platen 5, conveying rollers 6 and 7, a maintenance unit 8, etc.

[0012] The carriage 2 is supported by two guide rails 11 and 12 extending in the scanning direction. The carriage 2 is connected to a carriage motor 86 (see FIG. 4) via a belt or the like (not shown), and when the carriage motor 86 is driven, the carriage 2 moves in the scanning direction along the guide rails 11 and 12. In the following description, the right and left sides of the scanning direction are defined as shown in FIG.

[0013] The subtank 3 is mounted on the carriage 2. The printer 1 includes a cartridge holder 13, in which four ink cartridges 14 are removably attached. The four ink cartridges 14 are aligned in the scanning direction, and from the right side in the scanning direction, they store black, yellow, cyan, and magenta ink. The subtank 3 is connected to the four ink cartridges 14 attached to the cartridge holder 13 via four tubes 15. This allows the four colors of ink to be supplied from the four ink cartridges 14 to the subtank 3.

[0014] The inkjet head 4 is mounted on the carriage 2 and connected to the lower end of the subtank 3. The inkjet head 4 is supplied with the four colors of ink from the subtank 3. The inkjet head 4 ejects ink from a plurality of nozzles 10 formed on its lower surface, the nozzle face 4a. More specifically, the plurality of nozzles 10 are arranged in a transport direction perpendicular to the scanning direction to form nozzle rows 9, and on the nozzle face 4a, four nozzle rows 9 are aligned in the scanning direction. From the plurality of nozzles 10, black, yellow, cyan, and magenta inks are ejected, starting with the nozzles constituting the nozzle row 9 on the right side in the scanning direction.

[0015] The platen 5 is disposed below the inkjet head 4 and faces the multiple nozzles 10. The platen 5 extends over the entire length of the recording paper P (the "ejection receiving medium" of the present invention) in the scanning direction and supports the recording paper P from below. The transport roller 6 is disposed upstream of the inkjet head 4 and the platen 5 in the transport direction. The transport roller 7 is disposed downstream of the inkjet head 4 and the platen 5 in the transport direction. The transport rollers 6 and 7 are connected to a transport motor 87 (see FIG. 4) via gears and the like (not shown). When the transport motor 87 is driven, the transport rollers 6 and 7 rotate and the recording paper P is transported in the transport direction.

[0016] The maintenance unit 8 includes a cap 71, a suction pump 72, and a waste liquid tank 73. The cap 71 is disposed to the right of the platen 5 in the scanning direction. When the carriage 2 is positioned at a maintenance position to the right of the platen 5 in the scanning direction, the multiple nozzles 10 face the cap 71.

[0017] The cap 71 can be raised and lowered by a cap lifting mechanism 88 (see FIG. 4). When the carriage 2 is positioned at the maintenance position so that the plurality of nozzles 10 and the cap 71 face each other, and the cap lifting mechanism 88 raises the cap 71 from the uncapped position, which is lower than the capped position, to the capped position, the upper end of the cap 71 comes into close contact with the nozzle surface 4a, and the plurality of nozzles 10 are covered by the cap 71. Note that the cap 71 is not limited to covering the plurality of nozzles 10 by coming into close contact with the nozzle surface 4a. The cap 71 may also cover the plurality of nozzles 10 by coming into close contact with a frame (not shown) or the like that is arranged around the nozzle surface 4a of the inkjet head 4, for example.

[0018] The suction pump 72 is a tube pump or the like, and is connected to the cap 71 and the waste liquid tank 73. In the maintenance unit 8, when the suction pump 72 is driven with the plurality of nozzles 10 covered by the cap 71 as described above, it is possible to perform a so-called suction purge (recovery operation) in which ink is discharged from the inkjet head 4 through the plurality of nozzles 10. The ink discharged by the suction purge is stored in the waste liquid tank 73.

[0019] For convenience, the cap 71 has been described as covering all of the nozzles 10 together, and ink in the inkjet head 4 is discharged from all of the nozzles 10 during suction purging. However, this is not limiting. For example, the cap 71 may have separate portions covering the nozzles 10 constituting the rightmost nozzle row 9 that ejects black ink and the nozzles 10 constituting the three leftmost nozzle rows 9 that eject color inks (yellow, cyan, and magenta ink), so that either the black ink or the color ink in the inkjet head 4 can be selectively discharged during suction purging. Alternatively, for example, a cap 71 may be provided for each nozzle row 9, and ink can be discharged from the nozzles 10 for each nozzle row 9 individually during suction purging.

[0020] As shown in FIG. 2, a detection electrode 76 having a rectangular planar shape is disposed within the cap 71. The detection electrode 76 is connected to a high-voltage power supply circuit 77 via a resistor 79. A predetermined positive potential (e.g., approximately 600 V) is applied to the detection electrode 76 by the high-voltage power supply circuit 77 during inspection driving, which will be described later. Meanwhile, the inkjet head 4 is held at ground potential. This generates a predetermined potential difference between the inkjet head 4 and the detection electrode 76. A signal processing circuit 78 is connected to the detection electrode 76. The signal processing circuit 78 includes a differentiation circuit and the like, and outputs a signal obtained by performing processing, including differentiation, on the potential signal output from the detection electrode 76. In other words, the signal output from the signal processing circuit 78 is a voltage signal corresponding to the voltage of the detection electrode 76. However, the signal output from the signal processing circuit 78 may also be a current signal. In this embodiment, the combination of the detection electrode 76, the high-voltage power supply circuit 77, the signal processing circuit 78, and the resistor 79 corresponds to the "signal output section" of the present invention.

[0021] After the carriage 2 is positioned at the maintenance position, a voltage is applied to the detection electrode 76 by the high-voltage power supply circuit 77. At this time, when the inspection drive described below is not being performed, the voltage of the signal output from the signal processing circuit 78 becomes voltage V0 shown in Figures 3(a) and 3(b).

[0022] In this embodiment, the carriage 2 is positioned at the maintenance position, and while a voltage is applied to the detection electrode 76 by the high-voltage power supply circuit 77, an inspection drive is performed in which the inkjet head 4 is driven to eject ink from the nozzle 10 toward the detection electrode 76.

[0023] If the nozzle 10 is not an abnormal nozzle having an abnormality in ink ejection, charged ink is ejected from the nozzle 10 when the test drive is performed. This causes the charged ink to approach the detection electrode 76, and the potential of the detection electrode 76 changes until the ink lands on the detection electrode 76. Then, after the charged ink lands on the detection electrode 76, the potential of the detection electrode 76 attenuates and returns to the potential before the ink was ejected.

[0024] 3(a), the signal output from the signal processing circuit 78 (the "determination signal" of the present invention) rises from voltage V0 to voltage V1, which is greater than voltage V0, then drops to voltage V2, which is less than voltage V0, and then repeats rising and falling while attenuating, before returning to voltage V0. As a result, the signal output from the signal processing circuit 78 becomes a signal whose maximum value is voltage V1 and whose minimum value is voltage V2.

[0025] On the other hand, if the nozzle 10 is an abnormal nozzle, even if the test drive is performed, ink will not be ejected from the nozzle 10. Therefore, the signal output from the signal processing circuit 78 does not change from voltage V0, as shown in FIG.

[0026] In this manner, in this embodiment, the signal output from the signal processing circuit 78 when the test drive is performed differs depending on whether the nozzle 10 is an abnormal nozzle. This fact is then utilized in this embodiment to determine whether the nozzle 10 is an abnormal nozzle, as will be described later.

[0027] <Printer electrical configuration> Next, the electrical configuration of the printer 1 will be described. As shown in FIG. 4, the printer 1 has a control unit 80. The control unit 80 includes a central processing unit (CPU) 81, a read-only memory (ROM) 82, a random access memory (RAM) 83, a flash memory (referred to as a "storage unit" in this specification) 84, and an application-specific integrated circuit (ASIC) 85. The control unit 80 controls the operation of a carriage motor 86, inkjet head 4, a transport motor 87, a cap lifting mechanism 88, a suction pump 72, a high-voltage power supply circuit 77, a driver IC 89, and the like. In this embodiment, the control unit 80 controls the inkjet head 4 by controlling the driver IC 89. A determination signal is also input to the control unit 80 from the signal processing circuit 78.

[0028] In addition to the components described above, the printer 1 also has a clock unit 68, a display unit 69, an input unit 70, and a paper sensor 90. The clock unit 68 keeps time, and the control unit 80 receives a time signal indicating the time from the clock unit 68.

[0029] The display unit 69 is, for example, a liquid crystal display provided on the housing of the printer 1. The control unit 80 controls the display unit 69 to display information necessary for the operation of the printer 1. The input unit 70 is, for example, a button provided on the housing of the printer 1, a touch panel provided on the display unit 69, etc. The user can input signals to the control unit 80 by operating the input unit 70.

[0030] The paper sensor 90 is positioned between the inkjet head 4 and the transport roller 6 in the transport direction, detects the recording paper P being transported by the transport roller 6, and outputs a signal to the control unit 80 indicating that the recording paper P has been transported.

[0031] For example, if the paper sensor 90 does not detect the recording paper P even after a predetermined time has elapsed since the start of conveyance of the recording paper P during recording, a conveyance error such as a jam has occurred in the recording paper P. In this case, the ink in the multiple nozzles 10 may dry out, or the recording paper P may come into contact with the nozzles 10 and be damaged, resulting in abnormal ink ejection from the nozzles 10. If a conveyance error that causes such ink ejection abnormalities (the "device abnormality" of the present invention) occurs in the printer 1, the signal that the control unit 80 receives from the paper sensor 90 (the signal received a predetermined time after the start of conveyance of the recording paper P) will be a signal other than a signal indicating the detection of the recording paper P, and this signal (the "device abnormality signal" of the present invention) will indicate an apparatus abnormality. The paper sensor 90 in this embodiment corresponds to the "device abnormality output unit" of the present invention.

[0032] The control unit 80 may be configured such that only the CPU 81 performs various processes, or such that only the ASIC 85 performs various processes, or such that the CPU 81 and the ASIC 85 work together to perform various processes. The control unit 80 may be configured such that one CPU 81 performs processes independently, or such that multiple CPUs 81 share the processes. The control unit 80 may be configured such that one ASIC 85 performs processes independently, or such that multiple ASICs 85 share the processes.

[0033] <When a device error is detected> Next, a description will be given of the control by the control unit 80, which indicates the operation when detecting whether an apparatus abnormality has occurred in the printer 1. In the printer 1, when the above detection is made, the control unit 80 performs processing according to the flow of FIG.

[0034] Explaining the flow of FIG. 5 in more detail, the control unit 80 determines whether or not an apparatus abnormality signal has been received (S101). That is, it determines whether or not the paper sensor 90 has fallen into an apparatus abnormality such as that described above and output a signal indicating an apparatus abnormality signal to the control unit 80. If an apparatus abnormality signal has not been received (S101: NO), S101 is repeated. If an apparatus abnormality signal has been received (S101: YES), the control unit 80 stores apparatus abnormality flag information in the flash memory 84 (S102). The apparatus abnormality flag information is flag information indicating that an apparatus abnormality such as that described above has occurred in the printer 1. In this way, the flow of the apparatus abnormality detection process ends.

[0035] <Standby control> Next, a description will be given of the control by the control unit 80 during standby in the printer 1. During standby in the printer 1, the control unit 80 performs processing according to the flow of FIG.

[0036] 6 in more detail, the control unit 80 determines whether the time signal received from the clock unit 68 indicates a predetermined time (the "first condition" of the present invention) (S201). In this embodiment, the predetermined time is set to early morning, such as 6:00 AM, but is not particularly limited to this.

[0037] If the time signal received from the clock unit 68 does not indicate that it is the predetermined time (S201: NO), the control unit 80 determines whether the number of prints on the recording paper P has reached a predetermined cumulative number (the "first condition" of the present invention) (S202). On the other hand, if the time signal received from the clock unit 68 indicates that it is the predetermined time (S201: YES), the process proceeds to S205.

[0038] In S202, if the predetermined cumulative number is reached (S202: YES), the control unit 80 resets the cumulative number stored in the flash memory 84 to 0 (S203) and proceeds to S205. By resetting the cumulative number to 0 in this way, every time the predetermined cumulative number is reached, it becomes an opportunity to proceed to the inspection process of S207.

[0039] On the other hand, if the predetermined cumulative number has not been reached (S202: NO), the control unit 80 determines whether or not device abnormality flag information is stored in the flash memory 84 (the "first condition" of the present invention) (S204). If device abnormality flag information is not stored (S204), the process returns to S201. On the other hand, if device abnormality flag information is stored (S204: YES), the process proceeds to S205.

[0040] In S205, the control unit 80 determines whether or not prohibition flag information is stored in the flash memory 84. The prohibition flag information is flag information indicating that a test pattern printing process for printing a test pattern on recording paper P has been executed, and is flag information that prohibits predetermined operations (such as the inspection process and recovery process described below). If the prohibition flag information is stored (S205: YES), the flow ends. If the prohibition flag information is not stored (S205: NO), the control unit 80 erases the inspection flag information and recovery flag information described below from the flash memory 84 (S206). Next, the control unit 80 executes the inspection process (S207).

[0041] In S207, the control unit 80 places the inkjet head 4 in the maintenance position and transmits a drive signal to the driver IC 89 to perform a test drive, which drives each of the multiple nozzles 10 to eject ink in turn. At this time, the control unit 80 stores test flag information indicating that the test drive has been performed in the flash memory 84. The control unit 80 then determines whether a nozzle 10 is abnormal based on the determination signal output from the signal processing circuit 78 for each nozzle 10 during the test drive. The control unit 80 then stores in the flash memory 84 all of the multiple nozzles 10 that have been determined to be abnormal. In other words, the information stored in the flash memory 84 for the nozzle 10 that was previously abnormal is updated to the information for the nozzle 10 that is currently abnormal. This completes the flow of FIG. 6.

[0042] <Test pattern printing control> Next, we will explain the control by the control unit 80 when printing a test pattern in the printer 1. In the printer 1, when printing the test pattern, the control unit 80 performs processing according to the flow of FIG.

[0043] 7 will be explained in more detail, the control unit 80 determines whether or not a test pattern recording command signal (a "test pattern formation instruction" of the present invention) has been received through a user's operation on the input unit 70. The test pattern recording command signal is a signal for forming a predetermined test pattern on the recording paper P. The test pattern is used by the user to visually check whether or not a nozzle is abnormal.

[0044] If the test pattern recording command signal has not been received (S301: NO), S301 is repeated. If the test pattern recording command signal has been received (S301: YES), the control unit 80 executes the test pattern printing process (S302).

[0045] In S302, the control unit 80 controls the conveying motor 87 based on the test pattern recording command signal to cause the conveying rollers 6 and 7 to convey the recording paper P to a position where an area of ​​the recording paper P on which an image is to be recorded in the first recording pass faces the plurality of nozzles 10 of the inkjet head 4. Then, the control unit 80 controls the carriage motor 86 to move the carriage 2 in the scanning direction, while controlling the driver IC 89 to drive the plurality of drive elements, thereby causing the inkjet head 4 to perform a recording pass in which ink is ejected from the plurality of nozzles 10 toward the recording paper P.

[0046] Thereafter, if recording on one sheet of recording paper P is not complete, the control unit 80 controls the conveyance motor 87 to cause the conveyance rollers 6 and 7 to convey the recording paper P a predetermined distance, and repeats this operation of causing another recording pass until recording is complete on one sheet of recording paper P. If recording of an image on one sheet of recording paper P is complete, the control unit 80 controls the conveyance motor 87 to cause the conveyance rollers 6 and 7 to eject the recording paper P on which recording has been completed. At this time, the control unit 80 stores in the flash memory 84 the cumulative number of prints on which images have been recorded on the recording paper P.

[0047] Next, the control unit 80 determines whether or not a user determination signal (a "user determination instruction" of the present invention) has been received by the user operating the input unit 70 (S303). The user determination signal is a signal indicating the result of the user's confirmation of the test pattern formed on the recording paper P and their determination as to whether or not a recovery operation is necessary. If a user determination signal has not been input (S303: NO), S303 is repeated and an input from the user is awaited. If a user determination signal has been received (S303: YES), the control unit 80 determines whether or not to perform a recovery operation based on the user determination signal (S304).

[0048] If it is determined that a recovery operation should be performed (S304: YES), the control unit 80 executes the recovery process (S305). In the recovery process in this embodiment, the control unit 80 performs suction purging. If it is determined that a recovery operation should not be performed (S304: NO), the process proceeds to S306.

[0049] Next, in S306, the control unit 80 stores the prohibition flag information in the flash memory 84. Then, the flow for printing the test pattern is completed.

[0050] <Control during normal printing> Next, we will explain the control by the control unit 80 during normal printing other than test patterns in the printer 1. When the printer 1 receives a recording command signal to execute normal printing, the control unit 80 performs processing according to the flow in Fig. 8. The recording command signal is a signal that instructs the printer 1 to form an image on recording paper P, and is sent to the control unit 80 from an external device or the like.

[0051] 8 in more detail, the control unit 80 first determines whether or not a recording command signal has been received (S401). If a recording command signal has not been received (S401: NO), S401 is repeated. If a recording command signal has been received (S401: YES), the control unit 80 determines whether or not prohibition flag information is stored in the flash memory 84 (S402).

[0052] If prohibition flag information is stored (S402: YES), the control unit 80 increments the variable M by 1 (S403) and proceeds to S408. The variable M indicates the number of times the printing process is executed since the prohibition flag information was stored. On the other hand, if prohibition flag information is not stored (S402: NO), the control unit 80 determines whether inspection flag information is stored in the flash memory 84 (S404).

[0053] If the check flag information is not stored (S404: NO), S405, which is the same as S207 described above, is executed. On the other hand, if the check flag information is stored (S404: YES), the process proceeds to S406.

[0054] Next, the control unit 80 determines whether the number of abnormal nozzles stored in the flash memory 84 is equal to or greater than a threshold value (S406). The threshold value here refers to a threshold value for executing recovery processing immediately before degradation of image quality becomes noticeable. If the number of abnormal nozzles is less than the threshold value (S406: NO), the process proceeds to S408. On the other hand, if the number of abnormal nozzles is equal to or greater than the threshold value (S406: YES), the control unit 80 executes recovery processing similar to S305 described above (S407). In other words, if the process proceeds from S406 to S407, recovery processing is automatically executed in S407. At this time, the control unit 80 stores recovery flag information in the flash memory 84 indicating that recovery processing has been executed. The recovery flag information is information indicating that recovery processing has been executed. In this embodiment, the automatic recovery processing is executed prior to the printing processing described below.

[0055] Next, the control unit 80 executes the printing process (S408). In S408, the control unit 80 controls the conveyance motor 87, the carriage motor 86, and the driver IC 89 based on the recording command signal, and records an image on one sheet of recording paper P in the same manner as in S302 described above (the "discharge operation" of the present invention). Then, when recording of the image on one sheet of recording paper P is complete, the control unit 80 controls the conveyance motor 87 to cause the conveyance rollers 6 and 7 to eject the recording paper P on which recording has been completed. At this time, the control unit 80 stores the cumulative number of prints on which images have been recorded on the recording paper P in the flash memory 84. This ends the flow for normal printing.

[0056] <Recovery process prohibition release control> Next, a description will be given of recovery process prohibition release control in the printer 1. In the printer 1, when the prohibition is released, the control unit 80 performs the process according to the flow in FIG.

[0057] 9 will be described in more detail, the control unit 80 determines whether or not prohibition flag information is stored in the flash memory 84 (S501). If prohibition flag information is not stored (S501: NO), S501 is repeated. On the other hand, if prohibition flag information is stored (S501: YES), the control unit 80 determines whether or not the variable M is 1 (S502).

[0058] If the variable M is 1 (S502: YES), the control unit 80 determines that the predetermined condition (the "second condition" of the present invention) is satisfied because the printing process of S408 is executed after the prohibition flag information is stored. In this embodiment, the predetermined condition is that the printing process of S407 is executed and completed after the test pattern printing process is executed and the prohibition flag information is stored. As a result, the inspection process of S207 and the recovery process of S407 based on the inspection process of S207 are not executed until the predetermined condition is satisfied after the test pattern printing process is executed. Then, when the control unit 80 determines that the predetermined condition is satisfied, it erases the prohibition flag information from the flash memory 84 (S503). As a result, after the prohibition flag information is erased, the inspection process of S207 and the recovery process of S407 based on the inspection process can be executed. At this time, the control unit 80 also resets the variable M to 0.

[0059] On the other hand, if the variable M is 0 (S502: NO), the control unit 80 determines that the print process of S407 has not been executed after the prohibition flag information was stored, and then ends the flow of FIG.

[0060] As described above, with the printer 1 of this embodiment, regardless of whether or not recovery operation is performed based on the user's decision in response to the results of the test pattern formed on the recording paper P by the test pattern printing process (test pattern forming process), after the test pattern printing process has been performed, the automatic recovery process in S407 is not executed until at least a predetermined condition (second condition) is satisfied. This makes it possible to reduce unnecessary ink consumption.

[0061] Furthermore, if the test pattern printing process in S302 is performed after S207 and before the printing process in S408, the automatic recovery process in S407 prior to the printing process is not executed, which makes it possible to effectively reduce unnecessary ink consumption.

[0062] If S201 is YES, the process proceeds to S207 after a predetermined time and inspection processing becomes possible. Also, if S202 is YES, the process proceeds to S207 and inspection processing becomes possible after the number of printed sheets reaches a predetermined cumulative number. Also, if S204 is YES, the process proceeds to S207 and inspection processing becomes possible after a device abnormality occurs in the printer 1.

[0063] Furthermore, if the process proceeds to S207 from any of S201, S202, and S204, recovery processing can be executed in S407 before executing the print processing in S408. This allows automatic recovery processing to be executed before executing the print processing, thereby increasing the reliability of image quality.

[0064] Furthermore, if it is determined in S402 that prohibition flag information has been stored after receiving a print command signal in S401, the inspection process in S405 before the print process and the automatic recovery process in S407 are not executed. Furthermore, if it is determined that prohibition flag information has been stored when proceeding to S205 from either S201, S202, or S204, the inspection process in S207 is not executed. After the test pattern printing process is thus executed, the inspection process itself is not executed until at least the above-mentioned predetermined condition (second condition) is met. This reduces ink consumption due to the inspection process.

[0065] Next, a printer according to a second embodiment will be described below with reference to Figures 10 and 11. The printer according to this embodiment differs from the printer 1 according to the first embodiment in the prohibition release control, but is otherwise almost the same. Therefore, parts similar to those in the first embodiment are designated by the same reference numerals and will not be described again.

[0066] <Standby control> In the printer of this embodiment, during the standby state, the control unit 80 performs processing according to the flow shown in FIG.

[0067] 10 in more detail, the control unit 80 performs S201 described above and then proceeds to S205. If prohibition flag information is stored in S205 (S205: YES), the control unit 80 increments the variable N by 1 (S208) and ends the flow. The variable N indicates the number of times a predetermined time has passed since the prohibition flag information was stored.

[0068] In S205, if the prohibition flag information is not stored (S205: NO), the process proceeds to S206 and S207 described above, and the flow ends.

[0069] <Recovery process prohibition release control> In the printer of this embodiment, the control unit 80 performs processing according to the flow in Fig. 11. Explaining the flow in Fig. 11 in more detail, the control unit 80 executes S601, which is similar to S501. If prohibition flag information is not stored (S601: NO), S601 is repeated. On the other hand, if prohibition flag information is stored (S601: YES), the control unit 80 determines whether the variable N is 1 (S602).

[0070] If the variable N is 1 (S602: YES), the control unit 80 determines that a predetermined condition (the "second condition" of the present invention) has been satisfied. In this embodiment, the predetermined condition is a condition that prevents S206 from being executed when a predetermined time has elapsed after the test pattern printing process has been executed and the prohibition flag information has been stored, i.e., prevents the inspection process of S207 and the recovery process of S407 based on the inspection process of S207 from being executed. When the control unit 80 determines that the predetermined condition has been satisfied, it erases the prohibition flag information from the flash memory 84 (S603). As a result, after the prohibition flag information has been erased, S206 can be executed and the inspection process of S207 and the recovery process of S407 based on the inspection process of S207 can be executed when a predetermined time has elapsed. At this time, the control unit 80 also resets the variable N to 0.

[0071] On the other hand, if the variable N is 0 (S602: NO), the control unit 80 determines that it is the period from when the test pattern printing process was executed until the first predetermined time arrives, and then ends the flow of FIG.

[0072] As described above, in the printer of this embodiment, the automatic recovery process in S407 is not executed until at least the first predetermined time is reached after the test pattern printing process is executed. This makes it possible to suppress unnecessary ink consumption. Furthermore, the same effect can be obtained with a configuration similar to that of the first embodiment. Note that by setting the variable N in S602 to 2 or more, the number of times the predetermined time is reached can be arbitrarily changed, and the execution of the automatic recovery process in S407 can be prohibited until the predetermined number of times the predetermined time is reached.

[0073] Next, a printer according to a third embodiment will be described below with reference to Fig. 12. The printer according to this embodiment differs from the printer according to the second embodiment in the prohibition release control, but is otherwise substantially the same. Therefore, parts similar to those in the second embodiment are designated by the same reference numerals and will not be described again.

[0074] <Recovery process prohibition release control> In the printer of this embodiment, the control unit 80 performs processing according to the flow shown in FIG. 12. To explain the flow shown in FIG. 12 in more detail, the control unit 80 executes S701, which is similar to S601. If prohibition flag information is not stored (S701: NO), S701 is repeated. On the other hand, if prohibition flag information is stored (S701: YES), the control unit 80 determines whether a predetermined period (e.g., one day) has elapsed since the prohibition flag information was stored in the flash memory 84 (S702). In this embodiment, when the prohibition flag information is stored in S306, the control unit 80 also stores, in the flash memory 84, time information for when the prohibition flag information is stored, based on a time signal from the clock unit 68.

[0075] If the predetermined period has elapsed (S702: YES), the control unit 80 determines that a predetermined condition (the "second condition" of the present invention) has been satisfied, as in the second embodiment. In this embodiment, the predetermined condition is a condition that prevents S206 from being executed when a predetermined time has elapsed for a predetermined period of time after the test pattern printing process is executed and the prohibition flag information is stored. In other words, the control unit 80 does not execute the inspection process of S207 or the recovery process of S407 based on the inspection process of S207. When the control unit 80 determines that the predetermined condition has been satisfied, it erases the prohibition flag information from the flash memory 84 (S703). As a result, after the prohibition flag information is erased, S206 can be executed when a predetermined time has elapsed, and the inspection process of S207 and the recovery process of S407 based on the inspection process of S207 can be executed. At this time, the control unit 80 also erases the time information.

[0076] On the other hand, if the predetermined period has not elapsed (S702: NO), the control unit 80 determines that the predetermined period has not elapsed since the prohibition flag information was stored, and then ends the flow of FIG.

[0077] As described above, in the printer of this embodiment, the automatic recovery process in S407 is not executed until at least a predetermined period of time has elapsed since the test pattern printing process was executed. This makes it possible to reduce unnecessary ink consumption. Furthermore, in a configuration similar to that of the first embodiment, the same effect can be obtained.

[0078] Next, a printer according to a fourth embodiment will be described below with reference to Figures 13 to 15. The printer according to this embodiment is substantially the same as the printer 1 according to the first embodiment, except that it is capable of executing inspection processing but not recovery processing when prohibition flag information is stored in flash memory 84. Therefore, components similar to those in the first embodiment are designated by the same reference numerals and will not be described again.

[0079] <Standby control> In the printer of this embodiment, during the standby state, the control unit 80 performs processing according to the flow in Fig. 13. Explaining the flow in Fig. 13 in more detail, the control unit 80 performs the above-mentioned S201 to S204, and then proceeds to S206. That is, in this embodiment, regardless of whether or not prohibition flag information is stored, if any of S201, S202, and S204 is YES, the process proceeds to S206 and S207. In this way, the inspection process is executed, and the flow ends.

[0080] <Control during normal printing> In the printer of this embodiment, when a recording command signal for executing normal printing is received, the control unit 80 performs processing in accordance with the flow of FIG.

[0081] 14 in more detail, after the above-mentioned S401 is performed, the process proceeds to the above-mentioned S404 to S406. That is, in this embodiment, the above-mentioned S402 and S403 are omitted. Then, if the answer is YES in S406, the control unit 80 determines whether or not prohibition flag information is stored in the flash memory 84 (S409).

[0082] If prohibition flag information is stored (S409: YES), the control unit 80 increments the variable R by 1 (S410) and proceeds to S408. The variable R indicates the number of attempts to proceed from S406 to the recovery process of S407 since the prohibition flag information was stored. On the other hand, if prohibition flag information is not stored (S409: NO), the control unit 80 proceeds to S407 and executes automatic recovery processing. Thereafter, the control unit 80 executes the print processing of S408 and ends the flow for normal printing.

[0083] <Recovery process prohibition release control> In the printer of this embodiment, the control unit 80 performs processing according to the flow in Fig. 15. Explaining the flow in Fig. 15 in more detail, the control unit 80 executes S801, which is similar to S501. If prohibition flag information is not stored (S801: NO), S801 is repeated. On the other hand, if prohibition flag information is stored (S801: YES), the control unit 80 determines whether the variable R is 1 (S802).

[0084] If the variable R is 1 (S802: YES), the control unit 80 determines that a predetermined condition (the "second condition" of the present invention) has been satisfied. In this embodiment, the predetermined condition is a condition in which the recovery process of S407 is not executed once (the "predetermined number of times" of the present invention) after the test pattern printing process is executed and the prohibition flag information is stored, i.e., the recovery process of S407 based on the inspection process of S207 is not executed once. When the control unit 80 determines that the predetermined condition has been satisfied, it erases the prohibition flag information from the flash memory 84 (S803). As a result, after the prohibition flag information has been erased, the recovery process of S407 based on the inspection process of S207 can be executed. At this time, the control unit 80 also resets the variable R to 0.

[0085] On the other hand, if the variable R is 0 (S802: NO), the control unit 80 determines that the process has not proceeded to the recovery process of S407 since the test pattern printing process was executed, and then ends the flow of FIG.

[0086] As described above, in the printer of this embodiment, the automatic recovery process in S407 is not executed at least from the time the test pattern printing process is executed until the printer attempts to proceed to the recovery process in S407. In other words, the automatic recovery process is not executed once (a predetermined number of times) after the test pattern printing process is executed. This makes it possible to effectively suppress unnecessary ink consumption. Furthermore, the same effect can be obtained in a configuration similar to that of the first embodiment.

[0087] Next, a printer according to a fifth embodiment will be described below with reference to Figures 16 and 17. The printer according to this embodiment executes a test pattern inspection process after receiving a test pattern print command signal, and does not execute the recovery process of S407 while the number K of abnormal nozzles in the inspection processes of S207 and S405 is smaller than the number J of abnormal nozzles that would be detected if the recovery process of S305 after the test pattern printing process were not executed. Other than this, the printer is essentially the same as the printer according to the fourth embodiment. Therefore, parts similar to those in the fourth embodiment are designated by the same reference numerals and their description will be omitted.

[0088] <Test pattern printing control> In the printer of this embodiment, when printing the test pattern, the control unit 80 performs processing according to the flow of Fig. 16. Explaining the flow of Fig. 16 in more detail, if the answer to S301 above is YES, the control unit 80 executes inspection processing for the test pattern (S307). Thereafter, the control unit 80 executes S302 to S304 above.

[0089] If the control unit 80 determines in S304 that the recovery operation will not be performed (NO), it stores non-execution flag information indicating that the recovery operation will not be performed in the flash memory 84 (S308). After this, the process proceeds to S306, where the flow for printing the test pattern ends.

[0090] <Recovery process prohibition release control> In the printer of this embodiment, the control unit 80 performs processing according to the flow in Fig. 17. Explaining the flow in Fig. 17 in more detail, the control unit 80 executes S901, which is similar to S801. If prohibition flag information is not stored (S901: NO), S901 is repeated. On the other hand, if prohibition flag information is stored (S901: YES), the control unit 80 determines whether non-execution flag information is stored in the flash memory 84 (S902).

[0091] If no non-execution flag information is stored (S902: NO), the flow ends. On the other hand, if non-execution flag information is stored (S902: YES), the control unit 80 determines whether the number K of abnormal nozzles based on the inspection processes of S207 and S405 is greater than the number J of abnormal nozzles based on the test pattern inspection process of S307 when the recovery process of S305 after the test pattern printing process is not executed (S903).

[0092] If K is greater than J (S903: YES), the control unit 80 determines that a predetermined condition (the "second condition" of the present invention) is satisfied. In this embodiment, the predetermined condition is a condition in which at least recovery processing is not executed while K is equal to or less than J, i.e., recovery processing of S407 based on the inspection processing of S207 and S405 is not executed. When the control unit 80 determines that the predetermined condition is satisfied, it erases the prohibition flag information from the flash memory 84 (S904). As a result, after erasing the prohibition flag information, recovery processing of S407 based on the inspection processing of S207 and S405 can be executed. At this time, the non-execution flag information is also erased from the flash memory 84.

[0093] On the other hand, if K is equal to or less than J (S902: NO), the control unit 80 determines that the user has decided that there is no need to execute the recovery process, and then ends the flow of FIG.

[0094] As described above, in the printer of this embodiment, the automatic recovery process in S407 is not executed until the number K of abnormal nozzles becomes greater than the number J of abnormal nozzles after the test pattern printing process is executed. In other words, it is considered that the user does not need to execute the recovery process until the number J of abnormal nozzles exceeds the number J at which it is determined that the user does not need to execute the recovery process. As a result, it is possible to effectively suppress unnecessary ink consumption in accordance with the user's wishes. Furthermore, the same effect can be obtained with a configuration similar to that of the third embodiment.

[0095] In the above-described embodiments, the inspection flag information is stored in the flash memory 84 by executing the inspection process in S207. However, it is also possible to determine whether an error has occurred during the inspection process and store the inspection flag information only if no error has occurred. For example, before performing the inspection drive in the inspection process, the inkjet head 4 may be placed in the maintenance position and the high-voltage power supply circuit 77 may temporarily apply a voltage to the detection electrodes 76 to detect whether a leak current is flowing from the detection electrodes 76 to the inkjet head 4. If no leak current is flowing, the inspection drive may be performed, as in the above-described inspection process, and a determination may be made as to whether or not the nozzle is abnormal based on the determination signal output from the signal processing circuit 78 for each nozzle 10. The inspection flag information may then be stored. On the other hand, if a leak current is flowing, the inspection drive may not be performed at this time, and the inspection process of S405 may be performed instead. Before performing the test drive, the noise signal output from the signal processing circuit 78 is acquired, and if the noise signal is within a predetermined range, the test process is performed in the same manner as the test process described above. If the noise signal is so large that it exceeds the predetermined range, the test drive is not performed at this time, and the test process of S405 is performed instead.

[0096] In the above-described embodiments, the printer 1 determines whether an abnormality has occurred based on a signal received from the paper sensor 90. However, the printer 1 may also determine whether an abnormality has occurred by detecting that the printer 1 has not been properly powered off based on a signal from an encoder that detects the position of the carriage 2 in the scanning direction or a signal from a position sensor that detects the position of the cap 71. Alternatively, the printer 1 may determine whether an abnormality has occurred based on a signal from the encoder that detects the position of the carriage 2 in the scanning direction, upon detecting that a paper jam has occurred. The printer 1 may also be provided with a battery and a power supply detection circuit that outputs an abnormality signal to the control unit 80 indicating an abnormality when the battery's charge level reaches a minimum. In this case, if the battery runs out, power supply to the clock unit 68 is cut off, causing the clock unit 68 to lose track of time. This may result in an abnormality that prevents the process of S201 from being executed correctly. As a variant, if the printer 1 does not have a battery, the power supply detection circuit may be provided in the path through which power is supplied from the outlet to the control unit 80. The power supply detection circuit may then output a device abnormality signal to the control unit 80 when the power supply from the outlet to the control unit is cut off.

[0097] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. In each of the above-described embodiments, it is sufficient that at least one of the processes of S201, S202, and S204, which trigger the control unit 80 to execute the inspection process of S207, can be executed.

[0098] Furthermore, in the above-described embodiments, the recovery process is performed after the recording command signal is received, but it may be performed after the inspection process and before the recording command signal is received. In this case, the process of S205 may be performed before the inspection process or between the inspection process and the recovery process. In this case, it is also possible to restrict the execution of the recovery process or the inspection process and the recovery process until at least the predetermined condition (second condition) is satisfied.

[0099] Furthermore, in the above-described embodiments, the test drive is performed on all of the nozzles 10 of the inkjet head 4, but this is not limited to this. For example, the test drive may be performed on only some of the nozzles 10 of the inkjet head 4, such as every other nozzle 10 in each nozzle row 9, and the remaining nozzles 10 may be determined to be abnormal based on the determination signal output from the signal processing circuit 78 during the test drive.

[0100] Furthermore, in the above-described embodiment, the signal processing circuit 78 outputs a signal indicating whether or not the nozzle is abnormal, depending on the potential of the detection electrode 76 when ink is ejected from the nozzle 10 toward the detection electrode 76, but this is not limited to this.

[0101] For example, a detection electrode extending in the vertical direction may be disposed, and a signal indicating whether or not the nozzle is abnormal may be output from the signal processing circuit in accordance with the potential of the detection electrode when ink is ejected from the nozzle 10 so as to pass through an area facing the detection electrode. Alternatively, an optical sensor (the "signal output unit" of the present invention) may be provided to detect ink ejected from the nozzle 10, and a signal indicating whether or not the nozzle is abnormal may be output from the optical sensor.

[0102] Alternatively, for example, as described in Patent Publication No. 4929699, a voltage detection circuit (the "signal output unit" of the present invention) that detects changes in voltage when ink is ejected from the nozzles can be connected to the plate on which the nozzles of the inkjet head are formed, and a signal indicating whether or not the nozzle is abnormal can be output from the voltage detection circuit to the control unit 80.

[0103] Alternatively, for example, the substrate of the inkjet head may be provided with a temperature detection element (the "signal output unit" of the present invention), as described in Japanese Patent No. 6231759. Then, after applying a first applied voltage to drive the heater to eject ink, a second applied voltage is applied to drive the heater so that ink is not ejected, and a signal indicating whether or not the nozzle 10 is an abnormal nozzle may be output based on the change in temperature detected by the temperature detection element during the period from when the second applied voltage was applied until a predetermined time has elapsed.

[0104] Furthermore, in the above example, a nozzle 10 that does not eject ink is determined to be an abnormal nozzle, but this is not limited to this. For example, a signal output unit may be provided that outputs a signal depending on whether the ink ejection direction from the nozzle 10 is normal, and a nozzle 10 that has an abnormality in the ejection direction may be determined to be an abnormal nozzle based on the signal from this signal output unit.

[0105] Furthermore, a signal output unit may be provided that outputs a signal corresponding to a state of the abnormal nozzle other than the ink not being ejected, and information regarding the state of the abnormal nozzle may be obtained based on the signal from the signal output unit. An abnormal nozzle state may be, for example, a state in which the direction of ink ejection is abnormal, splashes occur, air bubbles are mixed in, or the nozzle is clogged with paper dust. In this case, the inspection drive may apply pressure to the ink to the extent that ink is not ejected from the nozzle 10, thereby vibrating the ink near the nozzle 10. Then, a signal corresponding to the vibration state of the ink near the nozzle 10 may be output from the signal output unit to obtain information regarding the state of the abnormal nozzle.

[0106] Furthermore, although suction purging is performed in the recovery process, this is not limiting. For example, a pressure pump may be provided midway along the tube 15 connecting the subtank 3 and the ink cartridge 14. Alternatively, a pressure pump connected to the ink cartridge may be provided in the printer. Then, with the plurality of nozzles 10 covered with caps 71, the pressure pump may be driven to pressurize the ink in the inkjet head 4 and discharge the ink from the inkjet head 4 through the nozzles 10, thereby performing so-called pressure purging. When pressure purging is performed for each color, a separate pressure pump may be provided for each color, or a switching mechanism for switching the connection to the pressure pump may be provided.

[0107] Furthermore, in the purging process, both suction by the suction pump 72 and pressurization by the pressure pump may be performed.

[0108] Furthermore, the method of recovering abnormal nozzles is not limited to purging. For example, abnormal nozzles may be recovered by flushing, which causes the inkjet head 4 to discharge ink from the nozzles 10. Alternatively, abnormal nozzles may be recovered by both purging and flushing. Alternatively, abnormal nozzles may be recovered by selectively performing either purging or flushing depending on the number of abnormal nozzles, etc.

[0109] Furthermore, although the present invention has been described as being applied to a printer equipped with a so-called serial head that ejects ink from multiple nozzles while moving in the scanning direction together with the carriage, the present invention is not limited to this. For example, the present invention can also be applied to a printer equipped with a so-called line head that extends across the entire length of the recording paper P in the scanning direction.

[0110] Furthermore, although the present invention has been described as being applied to a printer that ejects ink from nozzles to perform recording on recording paper P, the present invention is not limited to this. The present invention can also be applied to printers that record images on recording media other than recording paper, such as T-shirts, outdoor advertising sheets, cases for mobile devices such as smartphones, cardboard, and resin materials. The present invention can also be applied to liquid ejection devices that eject liquids other than ink, such as liquid resins and metals. [Explanation of symbols]

[0111] 1. Printer (liquid ejection device) 4. Inkjet head (liquid ejection head) 8 Maintenance Unit (Recovery Method) 10 nozzles 68 Clock Section 70 Input section 76 Detection electrode (part of the signal output section) 77 High voltage power supply circuit (part of the signal output section) 78 Signal processing circuit (part of the signal output section) 79 Resistor (part of signal output section) 80 Control Unit 84 Flash memory (storage section) 90 Paper sensor (device abnormality output section)

Claims

1. a liquid ejection head having a plurality of nozzles for ejecting liquid; a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; a recovery means for performing a recovery operation to discharge liquid from the nozzle; an input unit for a user to input a predetermined instruction; a control unit, The control unit when a user inputs a test pattern formation instruction to the input unit to form a test pattern on an ejection receiving medium to confirm whether or not the nozzle is the abnormal nozzle, a test pattern formation process is executed to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles; when a user inputs a user determination instruction to the input unit as to whether or not to execute the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determining whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction; performing the test drive after the first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold value based on the determination signal output from the signal output unit during the test drive, executing an automatic recovery process that causes the recovery means to perform the recovery operation; A liquid ejection device characterized in that after the test pattern formation process is performed, the automatic recovery process is not executed until at least a second condition different from the first condition is met, regardless of whether the recovery operation based on the user's judgment instruction has been executed.

2. a liquid ejection head having a plurality of nozzles for ejecting liquid; a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; a recovery means for performing a recovery operation to discharge liquid from the nozzle; an input unit for a user to input a predetermined instruction; a control unit, The control unit when a user inputs a test pattern formation instruction to the input unit to form a test pattern on an ejection receiving medium to confirm whether or not the nozzle is the abnormal nozzle, a test pattern formation process is executed to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles; when a user inputs a user determination instruction to the input unit as to whether or not to execute the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determining whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction; performing the test drive after the first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold value based on the determination signal output from the signal output unit during the test drive, executing an automatic recovery process that causes the recovery means to perform the recovery operation; after the test pattern forming process has been performed, the automatic recovery process is not executed until at least a second condition different from the first condition is satisfied, regardless of whether the recovery operation based on the user determination instruction has been executed or not; further comprising a clock unit that outputs a time signal indicating the time; The liquid ejection device is characterized in that the first condition is that the time signal indicating a predetermined time is output from the clock unit.

3. a liquid ejection head having a plurality of nozzles for ejecting liquid; a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; a recovery means for performing a recovery operation to discharge liquid from the nozzle; an input unit for a user to input a predetermined instruction; a control unit, The control unit when a user inputs a test pattern formation instruction to the input unit to form a test pattern on an ejection receiving medium to confirm whether or not the nozzle is the abnormal nozzle, a test pattern formation process is executed to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles; when a user inputs a user determination instruction to the input unit as to whether or not to execute the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determining whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction; performing the test drive after the first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold value based on the determination signal output from the signal output unit during the test drive, executing an automatic recovery process that causes the recovery means to perform the recovery operation; after the test pattern forming process has been performed, the automatic recovery process is not executed until at least a second condition different from the first condition is satisfied, regardless of whether the recovery operation based on the user determination instruction has been executed or not; Further comprising a storage unit, The control unit storing in the storage unit a cumulative number of ejection receiving media on which images have been formed by an ejection operation in which liquid is ejected from the plurality of nozzles of the liquid ejection head toward the ejection receiving medium; The liquid ejection apparatus according to claim 1, wherein the first condition is that the cumulative number of sheets stored in the storage unit reaches a predetermined number.

4. a liquid ejection head having a plurality of nozzles for ejecting liquid; a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; a recovery means for performing a recovery operation to discharge liquid from the nozzle; an input unit for a user to input a predetermined instruction; A liquid ejection device including a control unit, The control unit when a user inputs a test pattern formation instruction to the input unit to form a test pattern on an ejection receiving medium to confirm whether or not the nozzle is the abnormal nozzle, a test pattern formation process is executed to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles; when a user inputs a user determination instruction to the input unit as to whether or not to execute the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determining whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction; performing the test drive after the first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold value based on the determination signal output from the signal output unit during the test drive, executing an automatic recovery process that causes the recovery means to perform the recovery operation; After the test pattern forming process is performed, the automatic recovery process is not performed until at least a second condition is satisfied, further comprising an apparatus abnormality output unit that outputs an apparatus abnormality signal when an apparatus abnormality other than the abnormal nozzle occurs in the liquid ejection device; The liquid ejection apparatus is characterized in that the first condition is that the apparatus abnormality signal is output from the apparatus abnormality output section.

5. a liquid ejection head having a plurality of nozzles for ejecting liquid; a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; a recovery means for performing a recovery operation to discharge liquid from the nozzle; an input unit for a user to input a predetermined instruction; a control unit, The control unit when a user inputs a test pattern formation instruction to the input unit to form a test pattern on an ejection receiving medium to confirm whether or not the nozzle is the abnormal nozzle, a test pattern formation process is executed to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles; when a user inputs a user determination instruction to the input unit as to whether or not to execute the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determining whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction; performing the test drive after the first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold value based on the determination signal output from the signal output unit during the test drive, executing an automatic recovery process that causes the recovery means to perform the recovery operation; After the test pattern forming process is performed, the automatic recovery process is not performed until at least a second condition is satisfied, Furthermore, the control unit A liquid ejection device characterized in that, when performing an ejection operation in which the liquid ejection head ejects liquid from the multiple nozzles toward the ejection medium, if the number of abnormal nozzles based on the judgment signal output from the signal output unit during the inspection drive performed after the first condition is satisfied is equal to or greater than a threshold value, the automatic recovery process is executed prior to the ejection operation.

6. The liquid ejection device according to claim 5, characterized in that the second condition is that if the test pattern formation process is performed after the test drive that is performed after the first condition is satisfied and before the ejection operation is performed, the execution of the ejection operation is terminated.

7. a liquid ejection head having a plurality of nozzles for ejecting liquid; a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; a recovery means for performing a recovery operation to discharge liquid from the nozzle; an input unit for a user to input a predetermined instruction; a control unit, The control unit when a user inputs a test pattern formation instruction to the input unit to form a test pattern on an ejection receiving medium to confirm whether or not the nozzle is the abnormal nozzle, a test pattern formation process is executed to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles; when a user inputs a user determination instruction to the input unit as to whether or not to execute the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determining whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction; performing the test drive after the first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold value based on the determination signal output from the signal output unit during the test drive, executing an automatic recovery process that causes the recovery means to perform the recovery operation; After the test pattern forming process is performed, the automatic recovery process is not performed until at least a second condition is satisfied, Furthermore, the control unit The liquid ejection device is characterized in that, after the test pattern forming process has been performed, the test driving after the first condition is satisfied is not executed until at least the second condition is satisfied.

8. a liquid ejection head having a plurality of nozzles for ejecting liquid; a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; a recovery means for performing a recovery operation to discharge liquid from the nozzle; an input unit for a user to input a predetermined instruction; a control unit, The control unit when a user inputs a test pattern formation instruction to the input unit to form a test pattern on an ejection receiving medium to confirm whether or not the nozzle is the abnormal nozzle, a test pattern formation process is executed to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles; when a user inputs a user determination instruction to the input unit as to whether or not to execute the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determining whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction; performing the test drive after the first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold value based on the determination signal output from the signal output unit during the test drive, executing an automatic recovery process that causes the recovery means to perform the recovery operation; After the test pattern forming process is performed, the automatic recovery process is not performed until at least a second condition is satisfied, The liquid ejection apparatus according to claim 1, wherein the second condition is that the automatic recovery process is not executed a predetermined number of times after the test pattern formation process is executed.

9. a liquid ejection head having a plurality of nozzles for ejecting liquid; a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; a recovery means for performing a recovery operation to discharge liquid from the nozzle; an input unit for a user to input a predetermined instruction; a control unit, The control unit when a user inputs a test pattern formation instruction to the input unit to form a test pattern on an ejection receiving medium to confirm whether or not the nozzle is the abnormal nozzle, a test pattern formation process is executed to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles; when a user inputs a user determination instruction to the input unit as to whether or not to execute the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determining whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction; performing the test drive after the first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold value based on the determination signal output from the signal output unit during the test drive, executing an automatic recovery process that causes the recovery means to perform the recovery operation; After the test pattern forming process is performed, the automatic recovery process is not performed until at least a second condition is satisfied, The liquid ejection apparatus is characterized in that the second condition is that a predetermined period of time has elapsed since the test pattern formation process was performed.

10. a liquid ejection head having a plurality of nozzles for ejecting liquid; a signal output unit that outputs a determination signal according to whether or not the nozzle is an abnormal nozzle when the liquid ejection head is driven for inspection to confirm whether or not the nozzle is an abnormal nozzle having an abnormality in ejecting liquid; a recovery means for performing a recovery operation to discharge liquid from the nozzle; an input unit for a user to input a predetermined instruction; a control unit, The control unit when a user inputs a test pattern formation instruction to the input unit to form a test pattern on an ejection receiving medium to confirm whether or not the nozzle is the abnormal nozzle, a test pattern formation process is executed to form the test pattern on the ejection receiving medium by ejecting liquid from the plurality of nozzles; when a user inputs a user determination instruction to the input unit as to whether or not to execute the recovery operation corresponding to the test pattern formed on the ejection receiving medium by the test pattern formation process, determining whether or not to cause the recovery means to execute the recovery operation based on the user determination instruction; performing the test drive after the first condition is satisfied, and when it is determined that the number of abnormal nozzles is equal to or greater than a threshold value based on the determination signal output from the signal output unit during the test drive, executing an automatic recovery process that causes the recovery means to perform the recovery operation; After the test pattern forming process is performed, the automatic recovery process is not performed until at least a second condition is satisfied, Further comprising a storage unit, The control unit when the test pattern formation instruction is input to the input unit by a user, before or after the test pattern formation process is executed, the inspection drive is performed, and the abnormal nozzle based on the determination signal output from the signal output unit during the inspection drive is stored in the storage unit as a test pattern abnormal nozzle, A liquid ejection device characterized in that the second condition is that the number of abnormal nozzles based on the judgment signal output from the signal output unit during the inspection drive performed after the first condition is satisfied is greater than the number of abnormal nozzles for the test pattern when the recovery means is not caused to perform the recovery operation based on the user judgment instruction.

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