JP6988825B2 - Inkjet recording device and ink ejection control method for inkjet recording device - Google Patents

Description

The present invention relates to an inkjet recording device and an ink ejection control method for an inkjet recording device.

Conventionally, there is an inkjet recording device that ejects ink to a recording medium from an opening of a nozzle provided on the ink ejection surface of an ink ejection unit and records an image. In such an inkjet recording device, foreign matter may flow into the nozzle from the nozzle opening or ink may solidify at the nozzle opening, resulting in a defective nozzle that does not eject ink normally. Examples of the ink ejection failure in the defective nozzle include an abnormality in the ink ejection amount and the ejection direction. Further, in the defective nozzle, a small amount of mist-like ink (ink mist) may be generated more than the normal nozzle due to the ink ejection operation.

Such a defective nozzle leads to deterioration of the image quality of the recorded image. For this reason, conventionally, ink ejection (ink ejection) that is not based on the image data of the image to be recorded is performed at a predetermined timing or based on the user's instruction to prevent the inflow of foreign matter and the solidification of ink. There is a technique for suppressing the occurrence of defective nozzles or eliminating clogging of nozzles to restore the defective nozzles to a normal state (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-149629

However, depending on the opening state of the nozzle opening of the defective nozzle, there is a problem that the ink or ink mist abnormally ejected from the defective nozzle adheres to the ink ejection surface and the ink ejection surface is contaminated. When the ink ejection surface is contaminated in this way, the ink or ink mist adhering to the ink ejection surface falls on the recording medium and stains the recording medium, or solidifies in a state where a part of the nozzle opening is closed. It may cause a new defective nozzle.

An object of the present invention is to provide an ink jet recording apparatus and an ink ejection control method for an inkjet recording apparatus, which can suppress contamination of an ink ejection surface due to ejection.

In order to achieve the above object, the invention of the inkjet recording apparatus according to claim 1 is
An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
Equipped with
The discharge control means is used in the discharge control.
Ri selectable der whether ink is ejected from a nozzle which is identified as a defective nozzle by the defective nozzle information of the nozzle,
When a predetermined condition is satisfied, ink is not ejected from the nozzle specified as the defective nozzle by the defective nozzle information among the nozzles, and the nozzle is specified as the defective nozzle among the nozzles. Ink is ejected from each nozzle except the existing nozzle.
When the predetermined condition is not satisfied, ink is ejected from all the nozzles provided in the ink ejection unit .

The invention according to claim 2 is the inkjet recording apparatus according to claim 1.
An ejection state detection unit that detects the ejection state of ink from the nozzle,
A defective nozzle identification means for identifying a defective nozzle from the detection result by the discharge state detection unit and storing the defective nozzle information in the storage unit based on the specific result of the defective nozzle.
To prepare for.

In order to achieve the above object, the invention of the inkjet recording apparatus according to claim 3 is
An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
Equipped with
The discharge control means is
In the discharge control, it is possible to select whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is used. Of these, select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
When the image is recorded continuously after the ink ejection by the ejection disposal control, it is determined that the predetermined condition is satisfied.

In order to achieve the above object, the invention of the inkjet recording apparatus according to claim 4 is
An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
A cleaning unit that cleans the ink ejection surface and
A cleaning control means for cleaning the ink ejection surface by the cleaning unit, and a cleaning control means.
Equipped with
The discharge control means is
In the discharge control, it is possible to select whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is used. Of these, select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
When the image is recorded after the ink is ejected by the ejection disposal control and before the cleaning operation is performed, it is determined that the predetermined condition is satisfied.

In order to achieve the above object, the invention of the inkjet recording apparatus according to claim 5 is
An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
Equipped with
The discharge control means is
In the discharge control, it is possible to select whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is used. Of these, select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
In the ejection disposal control, it is determined that the predetermined condition is satisfied when the ink is ejected from the nozzle to the outside of the recording area of the image on the recording medium.

The invention of the inkjet recording apparatus according to claim 6 is to achieve the above object.
An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
Equipped with
The discharge control means is
In the discharge control, it is possible to select whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is used. Of these, select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
It is possible to perform the discharge control of a plurality of different types, and it is determined that the predetermined condition is satisfied when the predetermined discharge control is performed among the plurality of types of discharge control.

The invention according to claim 7 is the inkjet recording apparatus according to any one of claims 1 to 6.
The defective nozzle information includes initial defective nozzle information related to an initial defective nozzle associated with an initial defect of the ink ejection portion.
The storage unit has an initial defective nozzle information storage unit that stores the initial defective nozzle information.
The initial defective nozzle information storage unit is provided integrally with the ink ejection unit.

The invention according to claim 8 is the inkjet recording apparatus according to any one of claims 1 to 7.
The defective nozzle information includes initial defective nozzle information related to an initial defective nozzle associated with an initial defect of the ink ejection portion.
The ejection disposal control means selects not to eject ink from a nozzle specified as an initial defective nozzle by the initial defective nozzle information in the ejection disposal control.

Further, in order to achieve the above object, the invention of the ink ejection control method for the inkjet recording apparatus according to claim 9 is described.
An inkjet having an ink ejection surface having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles. It is an ink ejection control method of a recording device and includes a ejection disposal step of ejecting ink from the nozzle without being based on the image data of the image to be recorded.
In the dumping step
Select whether or not to eject ink from the nozzle specified as the defective nozzle by the defective nozzle information among the nozzles .
When a predetermined condition is satisfied, ink is not ejected from the nozzle specified as the defective nozzle by the defective nozzle information among the nozzles, and the nozzle is specified as the defective nozzle among the nozzles. Ink is ejected from each nozzle except the existing nozzle.
When the predetermined condition is not satisfied, ink is ejected from all the nozzles provided in the ink ejection unit .
In order to achieve the above object, the invention of the ink ejection control method of the inkjet recording apparatus according to claim 10 is described.
An inkjet having an ink ejection surface having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles. It is an ink ejection control method for recording devices.
Including a discharge step of ejecting ink from the nozzle without being based on the image data of the image to be recorded.
In the ejection step, it is selected whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is among the nozzles. Select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
It is determined that the predetermined condition is satisfied when the image is recorded continuously after the ink ejection in the ejection disposal step.
In order to achieve the above object, the invention of the ink ejection control method of the inkjet recording apparatus according to claim 11 is described.
An ink ejection unit having an ink ejection surface provided with an opening of a nozzle for ejecting ink, a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles, and the ink ejection surface. It is an ink ejection control method of an inkjet recording device equipped with a cleaning unit for cleaning.
A discharge step of ejecting ink from the nozzle without being based on the image data of the image to be recorded, and a discharge step.
A cleaning step in which the cleaning unit performs a cleaning operation on the ink ejection surface,
Including
In the ejection step, it is selected whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is among the nozzles. Select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
When the image is recorded after the ink is ejected in the ejection disposal step and before the cleaning operation is performed, it is determined that the predetermined condition is satisfied.
In order to achieve the above object, the invention of the ink ejection control method of the inkjet recording apparatus according to claim 12 is described.
An inkjet having an ink ejection surface having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles. It is an ink ejection control method for recording devices.
Including a discharge step of ejecting ink from the nozzle without being based on the image data of the image to be recorded.
In the ejection step, it is selected whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is among the nozzles. Select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
In the ejection disposal step, it is determined that the predetermined condition is satisfied when the ink is ejected from the nozzle to the outside of the recording area of the image on the recording medium.
In order to achieve the above object, the invention of the ink ejection control method of the inkjet recording apparatus according to claim 13 is described.
An inkjet having an ink ejection surface having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles. It is an ink ejection control method for recording devices.
Including a discharge step of ejecting ink from the nozzle without being based on the image data of the image to be recorded.
In the ejection step, it is selected whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is among the nozzles. Select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
It is possible to perform the discharge step of a plurality of different types, and it is determined that the predetermined condition is satisfied when the predetermined discharge step is performed among the plurality of types of the discharge step.

According to the present invention, there is an effect that contamination of the ink ejection surface due to ejection can be suppressed.

It is a figure which shows the schematic structure of the inkjet recording apparatus which is an embodiment of this invention. It is a block diagram which shows the main functional composition of an inkjet recording apparatus. It is a schematic diagram which shows the structure of a cleaning roller. It is a schematic diagram which shows the structure of an inspection part. It is a figure explaining the detection operation of a defective nozzle. It is a figure explaining the discharge area where ink is discharged in a recording medium. It is a block diagram which shows the functional structure which concerns on the control of a dumping in a head control part. It is a flowchart which shows the control procedure of an image recording process. It is a flowchart which shows the control procedure of the image recording process which concerns on modification 1.

Hereinafter, embodiments of the inkjet recording apparatus and the ink ejection control method of the inkjet recording apparatus of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an inkjet recording device 1 according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a main functional configuration of the inkjet recording device 1.

The inkjet recording device 1 includes a transport unit 10, a head unit 20 (ink ejection unit), a control unit 30 (defective nozzle identification means, cleaning control means), a head unit moving unit 41, a maintenance unit 42, and an inspection unit. It includes a 43 (discharge state detection unit), an operation display unit 44, an input / output interface 45, a bus 46, and the like.

The transport unit 10 includes a drive roller 11, a driven roller 12, a transport belt 13, and the like.
The drive roller 11 rotates about a rotation axis by driving a transfer motor (not shown). The transport belt 13 is a ring-shaped belt whose inside is supported by the drive roller 11 and the driven roller 12, and rotates orbits as the drive roller 11 rotates. The driven roller 12 rotates about a rotation axis parallel to the rotation axis of the drive roller 11 as the conveyor belt 13 orbits moves. As the transport belt 13, a material that flexibly bends at the contact surface with the drive roller 11 and the driven roller 12 and reliably supports the recording medium M is used. For example, a resin belt such as rubber or a belt made of resin such as rubber is used. A steel belt or the like can be used. Since the transport belt 13 has a material and / or a configuration in which the recording medium M is adsorbed, the recording medium M can be more stably mounted on the transport belt 13. The transport unit 10 transports the recording medium M by rotating the transport belt 13 at a speed corresponding to the rotation speed of the drive roller 11 in a state where the recording medium M is placed on the transport surface of the transport belt 13. A transport operation for transporting in the moving direction of 13 (transportation direction: Y direction in FIG. 1) is performed. An encoder (rotary encoder) (not shown) is provided on the drive shaft of the drive roller 11 so that the circumferential movement distance of the conveyor belt 13 can be measured.
The recording medium M may be conveyed intermittently, for example, by suspending the ink ejection unit 10 for a period of time. The transport operation by the transport unit 10 shall include an operation of suspending the transport as described above.

In this embodiment, a cloth is used as the recording medium M. The recording medium M is unwound (unrolled) from the roll on which the recording medium M is wound and supplied onto the transport belt 13. The recording medium M has a rectangular shape having a width of about 2 [m] in the width direction (X direction in FIG. 1) orthogonal to the transport direction and a length of about 4000 [m] in the transport direction. The recording medium M having a width smaller than 2 [m] in the width direction may be conveyed by the conveying unit 10. Further, the transport unit 10 may be configured to be capable of transporting the recording medium M having a width larger than 2 [m] (for example, about 4 [m]) in the width direction, and the transportable recording medium M may be configured. The maximum width in the width direction may be smaller than 2 [m].
The recording medium M is not limited to the above-mentioned cloth, and various media such as paper and sheet-shaped resin capable of fixing the ejected ink to the surface can be used.

The head unit 20 ejects ink from a nozzle to the recording medium M conveyed by the conveying unit 10 based on the image data, and records an image on the recording medium M. In the inkjet recording apparatus 1 of the present embodiment, four head units 20 corresponding to four colors of ink of yellow (Y), magenta (M), cyan (C), and black (K) are in the transport direction of the recording medium M. They are arranged so as to be arranged at predetermined intervals in the order of Y, M, C, and K colors from the upstream side.

Each head unit 20 has a plurality of recording elements arranged in a direction intersecting the transport direction of the recording medium M (in the present embodiment, a width direction orthogonal to the transport direction, that is, the X direction) (7 in the present embodiment). The recording head 22 is provided with a head control unit 21 for controlling the ink ejection operation by the recording head 22. Each recording head 22 has an ink ejection surface provided with an opening of a nozzle, and the ink ejection surface is arranged at a position facing the conveying surface of the conveying belt 13. Further, each head unit 20 is provided with a first storage unit 23 (storage unit, initial defective nozzle information storage unit) integrally with the head unit 20.

Each of the recording elements included in the recording head 22 includes a pressure chamber for storing ink, a piezoelectric element provided on the wall surface of the pressure chamber, and a nozzle for ejecting ink. When a drive signal is applied to the piezoelectric element from the drive circuit in the recording head 22, the piezoelectric element is deformed in response to this drive signal to change the pressure in the pressure chamber, and ink is ejected from a nozzle communicating with the pressure chamber. To. In the following, the operation related to ink ejection from the nozzle in response to the drive signal is also referred to as ink ejection operation. It should be noted that the operation when the nozzle is a defective nozzle, which will be described later, and the ink is not ejected according to the drive signal is also included in the ink ejection operation.
The arrangement range of the recording element included in the head unit 20 in the X direction covers the width of the recording medium M conveyed by the conveying unit 10 in the X direction of the region where an image can be recorded. Is used with its position fixed with respect to the transport unit 10 when recording an image. That is, the inkjet recording device 1 records an image by a single pass method.

In the head unit 20, when the head unit 20 is manufactured, a part of the nozzle is a defective nozzle that does not eject ink normally due to processing variation at the time of nozzle formation, characteristic variation of the piezoelectric element, and the like. There is. Further, as a result of using the head unit 20 in the inkjet recording device 1, foreign matter flows into the nozzle from the nozzle opening and becomes clogged, or ink solidifies at the nozzle opening, resulting in a defective nozzle later. In some cases. Examples of poor ink ejection in the defective nozzle include non-ejection of ink and abnormalities in the amount of ink ejected and the ejection direction. Further, in a defective nozzle having an abnormality in the ink ejection amount or the ejection direction, minute mist-like ink (ink mist) may be generated more than the normal nozzle as the ink is ejected.
In the present embodiment, as the head unit 20, a head unit 20 in which a defective nozzle (initial defective nozzle) related to an initial defect is detected after manufacturing is used. Further, in the present embodiment, the defective nozzle detected for the first time after the detection of the initial defective nozzle is referred to as a late defect nozzle.

The detection of the initial defective nozzle is performed by an external inspection device (separate from the inkjet recording device 1). For example, ink (or droplets for inspection) is ejected from each nozzle of the head unit 20, and the ejected ink is photographed by the inspection device from the side in the ink ejection direction to determine the ink ejection state. If no ink is detected in the shooting data, it is determined that the ink is not ejected, if the ink ejection direction is bent, it is determined that the ink ejection direction is abnormal, and if the ink flying speed is not normal, the ink ejection is determined. It is determined that the amount is abnormal, and the ink obtained by these determinations is detected as an initial defective nozzle. Here, the fact that the ink ejection direction is bent means that the ink is ejected in a bent direction with respect to the original ejection direction.

The head control unit 21 refers to the head drive unit of the recording head 22 at an appropriate timing according to the count number of the control signal from the control unit 30 and the pulse signal input from the rotary encoder attached to the drive roller. Outputs various control signals and image data. The head drive unit of the recording head 22 supplies a drive signal for deforming the piezoelectric element to the recording element of the recording head 22 according to the control signal and image data input from the head control unit 21, and the head drive unit of each nozzle. Ink is ejected from the opening. In the present embodiment, the discharge control means is configured by the control unit 30 and the head control unit 21.

The first storage unit 23 is composed of a non-volatile memory such as a flash memory or an EEPROM (Electrically Erasable Programmable Read Only Memory), and stores initial defective nozzle data D1 (initial defective nozzle information) related to the above-mentioned initial defective nozzle. .. In the initial defective nozzle data D1, the initial defective nozzle is specified by the array number of the nozzles in the head unit 20. The first storage unit 23 may be configured by a ROM (Read Only Memory).

The head unit moving unit 41 raises or lowers the head unit 20 in the Z direction (distance direction) perpendicular to the transport surface of the transport belt 13. Further, the head unit moving unit 41 moves the head unit 20 that has risen to a predetermined position in the Z direction to a position facing the ink receiving unit of the maintenance unit 42, which will be described later, in the X direction. Among the head unit moving portions 41, the mechanism for raising and lowering the head unit 20 in the Z direction is, for example, a strut portion extending in the Z direction and a strut portion to which the head unit 20 is fixed and movable in the Z direction along the strut portion by rotation of the stepping motor. It can be configured by a moving part. Further, the mechanism for moving the head unit 20 in the X direction among the head unit moving portions 41 is composed of, for example, a guide rail extending in the X direction and a slide member to which the head unit 20 is fixed and moves along the guide rail. be able to.
Four head unit moving portions 41 are provided corresponding to each of the four head units 20.

The maintenance unit 42 includes an ink receiving unit (not shown) that receives the ink ejected by the ink ejection (flushing) from the nozzle of the head unit 20. Here, the ejection is to eject ink from the defective nozzles for the purpose of restoring the nozzles that can be restored to the normal state in which the ink is ejected normally to the normal state, or suppressing the generation of new defective nozzles. This is the operation of the head unit 20 for discharging. For this ejection, ink is ejected from the nozzle of the head unit 20 without being based on the image data of the image to be recorded in the inkjet recording apparatus 1 (normal image for which recording is instructed by a print job, various test images, etc.). Includes all actions to be made. For example, in addition to the ejection to the ink receiving portion of the maintenance unit 42 (hereinafter, also referred to as the second ejection), to the outside of the image recording area of the recording medium M during the execution of the print job. There is a vomit that is performed (hereinafter also referred to as the first vomit). The details of throwing away will be described later.

Further, the maintenance unit 42 includes a cleaning roller (cleaning unit) that performs a cleaning operation (hereinafter, also referred to as “wiping”) for wiping and cleaning the ink ejection surface of the head unit 20.

FIG. 3 is a schematic view showing the configuration of the cleaning roller 421.
In the cleaning roller 421, a wiping cloth containing a predetermined chemical solution is wound around the outer peripheral surface, and the rotation axis is arranged so as to be parallel to the Y direction. The maintenance unit 42 has a rotary motor and a transfer motor (not shown), and the cleaning roller 421 rotates according to the operation of the rotary motor and is moved in the Z direction and the X direction according to the operation of the transfer motor. When the above-mentioned wiping is performed, the cleaning roller 421 is moved in the Z direction by the operation of the transfer motor to come into contact with the ink ejection surface of the head unit 20, and in this state, while rotating by the operation of the rotary motor. The ink ejection surface of the head unit 20 is wiped by moving in the X direction according to the operation of the transfer motor. Four cleaning rollers 421 are provided corresponding to each of the four head units 20.

The inspection unit 43 performs a predetermined measurement operation for detecting the ink ejection state from each nozzle.

FIG. 4 is a schematic diagram showing the configuration of the inspection unit 43.
The inspection unit 43 includes a light emitting unit 431, a light receiving unit 432, a moving unit 433, a moving belt 434, rollers 435a and 435b, a motor 436, a linear encoder 437, and the like. The inspection unit 43 irradiates the flight path of the ink from the nozzle with light by the light emitting unit 431, and measures the amount of the light by the light receiving unit 432. By determining whether or not the measured amount of light is reduced by the ink at an appropriate position according to the nozzle, the ejection state of the ink from each nozzle is inspected. The measurement operation by the inspection unit 43 is performed on the head unit 20 that has been moved to the + Z direction side from the recording operation by the head unit moving unit 41, for example, as shown in FIG. Alternatively, the measurement operation may be performed by moving the head unit 20 to the position of the inspection unit 43.

The light emitting unit 431 outputs light (here, visible light) in the L direction of the optical axis. The light receiving unit 432 detects the light output from the light emitting unit 431. The light output from the light emitting unit 431 has directivity, and in the absence of a light-shielding object, that is, ink, most of the output light is detected by the light receiving unit 432. On the other hand, the light receiving unit 432 is narrow within a range in which the amount of dimming when the ink to be detected enters the light receiving area is equal to or more than the detectable ratio to the total amount of incident light, and the mounting accuracy of the inspection unit 43 and the motor. It is determined that the position of the ink is widened within a range that does not deviate from the light receiving area when the position shift related to the rotational operation accuracy of the 436 occurs.
The moving unit 433 is a plate-shaped member, and a light emitting unit 431 and a light receiving unit 432 are fixed on the plate surface. One end of the moving unit 433 is fixed to the moving belt 434.
The moving belt 434 has a ring shape and is rotationally driven by rollers 435a and 435b provided on the inner peripheral surface. The moving belt 434 is rotationally driven to move the moving unit 433 in the X direction.
The motor 436 rotates the roller 435a. The rotation speed of the motor 436 can be appropriately changed based on the control signal from the control unit 30.
The linear encoder 437 outputs a signal indicating the movement of the moving unit 433. The linear encoder 437 is not particularly limited, but for example, a linear encoder having a scale that is read by an optical sensor is used.

The operation display unit 44 includes a display device such as a liquid crystal display or an organic EL display, and an input device such as an operation key and a touch panel arranged on the screen of the display device. The operation display unit 44 displays various information on the display device, converts the user's input operation to the input device into an operation signal, and outputs it to the control unit 30.

The input / output interface 45 is a means for transmitting / receiving data to / from the external device 2, and is composed of, for example, various serial interfaces, various parallel interfaces, or a combination thereof.

The bus 46 is a path for transmitting and receiving signals between the control unit 30 and other configurations.

The control unit 30 includes a CPU 31 (Central Processing Unit), a RAM 32 (Random Access Memory), a ROM 33, and a second storage unit 34 (storage unit).

The CPU 31 reads out various control programs and setting data stored in the ROM 33 and stores them in the RAM 32, and executes the program to perform various arithmetic processes. The CPU 31 controls the overall operation of the inkjet recording device 1 in an integrated manner. For example, the CPU 31 ejects ink from the nozzle to the recording medium M by the head unit 20 based on the image data of the image stored in the second storage unit 34 while the recording medium M is conveyed by the conveying unit 10. Let them record the image.

The RAM 32 provides a working memory space to the CPU 31 and stores temporary data. The RAM 32 stores a maintenance flag used for determining the implementation status of the maintenance operation. Here, the maintenance flag is binary data represented by 1 bit. The RAM 32 may include a non-volatile memory.

The ROM 33 stores various control programs, setting data, and the like executed by the CPU 31. Instead of the ROM 33, a rewritable non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used.

The second storage unit 34 has defective nozzle data D2 relating to the initial defective nozzle indicated by the initial defective nozzle data D1 of the first storage unit 23 and the defective nozzle including the late defect nozzle detected by the operation of the inspection unit 43. (Defective nozzle information) is stored. In the defective nozzle data D2, the defective nozzle is specified by the array number of the nozzles in each head unit 20. The defective nozzle data D2 is data generated in the defective nozzle detection operation described later. The defective nozzle data D2 may include only the data related to the defective nozzle (that is, the late defective nozzle) excluding the initial defective nozzle. In this case, the initial defective nozzle is specified by referring to the initial defective nozzle data D1 of the first storage unit 23.
Further, the second storage unit 34 stores a print job (image recording command) and image data input from the external device 2 via the input / output interface 45, and image data corrected by the CPU 31. As the second storage unit 34, for example, an HDD (Hard Disk Drive) may be used, or a DRAM (Dynamic Random Access Memory) or the like may be used in combination.

The external device 2 is, for example, a personal computer, and supplies print jobs, image data, and the like to the control unit 30 via the input / output interface 45.

Next, various operations related to the management of defective nozzles in the inkjet recording apparatus 1 will be described. Here, in the management of defective nozzles, detection of defective nozzles, setting of complementation of non-ejection of ink from defective nozzles by correction of image data, ejection during execution of a print job, maintenance operation of the head unit 20, and maintenance operation of the head unit 20 are performed. Replacement of the head unit 20 is included.

First, the operation of detecting a defective nozzle executed in the inkjet recording apparatus 1 will be described.
In the inkjet recording device 1, the defective nozzle of the head unit 20 is detected when a predetermined defective nozzle detection start condition is satisfied. Here, the defective nozzle detection start condition can be, for example, that the recording operation by the head unit 20 is performed a predetermined number of times or more after the last defective nozzle detection operation. Alternatively, it may be assumed that the ink is consumed in a predetermined amount or more after the last defective nozzle detection operation. Further, the detection of defective nozzles may be started by a user's instruction.

FIG. 5 is a diagram illustrating a defective nozzle detection operation.
In this figure, the position of the nozzle 221 on the ink ejection surface 222 of the recording head 22 in the plan view of the recording head 22 of the head unit 20 and the moving unit 433 of the inspection unit 43 viewed from the side facing the transport surface of the transport belt 13. Is schematically shown.

When starting the detection of defective nozzles, the head unit 20 is moved by the head unit moving unit 41 to the + Z direction side from the recording operation, and the inspection unit 43 is arranged between the head unit 20 and the transport belt 13. To. Alternatively, the head unit 20 may be moved to a position above the inspection unit 43.
Then, the moving unit 433 is moved to a position facing the recording head 22 based on the signal related to the measurement of the linear encoder 437. That is, the moving unit 433 is moved to a position where the optical axis L of the light output from the light emitting unit 431 and detected by the light receiving unit 432 crosses the ink flight path from the leading nozzle 221. Here, the head nozzle 221 is a nozzle 221 located at the end portion (left end in FIG. 5) on the + X direction side of the recording head 22 on the most + X direction side. Subsequently, while ejecting ink from each nozzle 221 of the recording head 22 in order for a predetermined time, the light emitting unit 431 and the light receiving unit 432 moved to the positions corresponding to the nozzle 221 are operated to measure the amount of light by the light receiving unit 432. Ink ejection status is inspected based on the measurement results. That is, when the decrease in the amount of light due to the ink is not detected at the position corresponding to the nozzle 221, the non-ejection of the ink is detected, and when the position where the decrease in the amount of light is detected deviates from the position corresponding to the nozzle 221 of the ink. Bending in the discharge direction is detected. The nozzle 221 from which ink is ejected is changed one by one in the −X direction of FIG. 5, and changes to the nozzle 221 at the end of the recording head on the most −X direction side (right end in FIG. 5). The change speed at this time is set to be constant, and the moving unit 433 is moved at a constant speed according to the constant change speed.
The defective nozzle detection operation is performed for all nozzles including the nozzle already identified as a defective nozzle by the defective nozzle data D2. Further, the above-mentioned defective nozzle detection operation is performed for each of the four head units 20.

In this way, by the operation of the light emitting unit 431 and the light receiving unit 432, the amount of light reflecting the ink ejection state from the nozzle 221 of each head unit 20 is measured, and the ink ejection state from the nozzle 221 is determined by the measurement result. Be inspected. As a result of the inspection, when non-ejection of ink or bending in the ejection direction of ink is detected, the corresponding nozzle is identified as a defective nozzle. When the defective nozzle is identified, the defective nozzle data D2 indicating the defective nozzle is generated based on the sequence number in the head unit 20 of the identified nozzle 221 and stored in the second storage unit 34.
Here, when the defective nozzle data D2 is already stored in the second storage unit 34, the new defective nozzle data D2 is overwritten with the existing defective nozzle data D2. When it is necessary to refer to the history of the occurrence status of the latecomer defective nozzle, new defective nozzle data D2 different from the existing defective nozzle data may be generated and stored.

Next, the correction of the image data based on the defective nozzle data D2 will be described.
In the inkjet recording apparatus 1, when a defective nozzle is specified by the defective nozzle data D2, the image data of the image specified by the print job is corrected to suppress the distortion of the recorded image due to the defective nozzle. The image is recorded above. For example, when the nozzle 221a shown in FIG. 5 is specified as a defective nozzle, the image data of the image is corrected so that the ink is not ejected from the nozzle 221a, and the nozzle adjacent to the defective nozzle (FIG. 5). The image data of the image is corrected so that the non-ejection of ink from the defective nozzle is complemented by the increase in the amount of ejected ink from the nozzle 221b) or the nozzle near the defective nozzle (for example, the nozzles 221b and 123c in FIG. 5). Will be done. Then, ink is ejected from the head unit 20 to the recording medium M based on the corrected image data, so that an image in which image quality deterioration due to a defective nozzle is suppressed is recorded.

When the head unit 20 is replaced and an image is recorded by the unused head unit 20, the defective nozzle data D2 related to the head unit 20 is reset. That is, since the head unit 20 does not have a latecomer defective nozzle, the defective nozzle data D2 is generated based on the initial defective nozzle data D1 stored in the first storage unit 23 of the head unit 20. It is stored in the second storage unit 34. Then, the image data of the image is corrected based on the new defective nozzle data D2. Therefore, when the head unit 20 is replaced with an unused one, it is possible to correct the image data without performing the defective nozzle detection operation, and the image is displayed based on the corrected image data. Recorded.

Next, the ink ejection (first ejection) performed during the execution of the print job will be described.
In the inkjet recording apparatus 1, when the viscosity of the ink in the vicinity of the opening increases due to the vaporization of the ink solvent in the vicinity of the opening of the nozzle 221, the amount of the ejected ink, the flight direction, the flight speed, and the like are set from the original settings. Defective nozzles with misaligned ink ejection defects occur. In particular, in the present embodiment, since the normal image to be recorded is continuously recorded on the recording medium M as long as 4000 m, when the image recording operation is started, for example, the transport speed is 60 [m / min]. ], The image recording operation is continued for about 1 hour. In this image recording operation, depending on the content of the normal image, a nozzle 221 in which the ink ejection frequency is extremely low or the ink is not ejected is generated, and such a nozzle 221 is the ink described above during the duration of the image recording operation. It is easy to become a defective nozzle due to the thickening of the ink.
Therefore, in the inkjet recording apparatus 1 of the present embodiment, in order to suppress the occurrence of such defective nozzles, ink is ejected from the nozzle 221 to the outside of the recording area of a normal image on the recording medium M being conveyed. 1 is thrown away.

FIG. 6 is a diagram illustrating a discharge area where ink is discharged in the recording medium M.
As shown in FIG. 6, in the present embodiment, the first dumping is performed on the band-shaped dumping region 52 extending in the X direction in the recording medium M. A normal image 51 is recorded on the upstream side and the downstream side of the discharge region 52 in the Y direction. That is, the dumping area 52 is usually set outside the recording area of the image 51. The normal image 51 is a long image in which a plurality of unit images connecting the front end and the rear end in the Y direction are connected in the Y direction, and is recorded so as to be continuous in the recording area of the normal image 51.

The discharge area 52 includes color-coded discharge areas 52Y, 52M, 52C, and 52K in which ink is discharged by the head unit 20 corresponding to Y, M, C, and K, respectively. The color-coded discharge regions 52Y, 52M, 52C, and 52K are strip-shaped regions that are adjacent to each other in the Y direction and extend in the X direction over the recording range of the nozzle 221 in the head unit 20. Further, about 1000 times of ink ejection is continuously performed from each nozzle of the head unit 20 to the color-coded ejection discarding areas 52Y, 52M, 52C, and 52K. The range of the discharge area 52 in the X direction is equal to the recording range of the normal image 51 in the X direction. The reason why the color-specific ejection areas 52Y, 52M, 52C, and 52K do not overlap each other is mainly to suppress the ink ejection amount per unit area and suppress the ink show-through. If it does not occur or does not cause a problem, they may overlap with each other.
In the first ejection, ink is ejected to a strip-shaped (long rectangular) range on the recording medium M in the Y direction according to the position of the nozzle 221 provided in each recording head 22 in the Y direction. The ink ejection timing is adjusted so as to be.

Further, in the present embodiment, when the ink is discharged, it is possible to select whether or not to eject the ink from the nozzle 221 specified as the defective nozzle in the defective nozzle data D2. In the above-mentioned first ejection, the ink is not ejected from the nozzle 221 specified as the defective nozzle in the defective nozzle data D2, and the ink is ejected only from the normal nozzle 221. As a result, the ink and ink mist abnormally ejected from the defective nozzle due to the first ejection adhere to the ink ejection surface 222, the ink ejection surface 222 is contaminated with the ink, and the ink is affected by the air flow and cloth dust. It is possible to suppress the occurrence of problems such as dropping onto the recording medium M at an unintended timing or solidifying with a part of the nozzle opening closed to generate a new defective nozzle. In particular, as shown in FIG. 6, when the ink is discharged to the outside of the recording area of the normal image 51 of the recording medium M, the normal image is immediately after the discharge without cleaning the ink ejection surface 222. Since the recording operation of 51 is performed, contamination of the ink ejection surface 222 caused by ink from the defective nozzle leads to contamination of the recording medium M due to ink dropping, but the ink ejection from the defective nozzle is not performed in the ejection. The occurrence of such problems is effectively suppressed.
As described above, in the present embodiment, the condition that the image is recorded continuously after the ink ejection by the ejection (predetermined condition), and the cleaning operation for cleaning the ink ejection surface 222 after the ink ejection by the ejection disposal. When the condition that the image is recorded before the above (predetermined condition) or the condition that the ink is ejected from the nozzle 221 outside the image recording area on the recording medium M (predetermined condition) is satisfied. In the case of discarding the ink, the ink is not ejected from the nozzle 221 specified as the defective nozzle in the defective nozzle data D2.

Hereinafter, the first discharge control operation in the inkjet recording device 1 will be described.
During the execution of the print job, due to the transfer of the recording medium M by the transfer unit 10, the predetermined position (the tip of the color-coded discharge area 52Y, 52M, 52C, 52K) to be discarded is the ink of the ink by each head unit 20. When the head unit 20 moves to the discharge position, the discharge is started by each head unit 20 (hereinafter, the predetermined position is also referred to as a discharge start position). The fact that the ejection start position has moved to the ink ejection position is determined by the fact that the rotary encoder attached to the drive roller outputs a predetermined number of pulse signals for each head unit 20.

FIG. 7 is a block diagram showing a functional configuration related to the control of dumping in the head control unit 21.
As shown in FIG. 7, the head control unit 21 includes a control circuit 21a, a switching unit 21b, and an image data storage unit 21c. The head control unit 21 can be configured to include, for example, a circuit board and an FPGA (Field Programmable Gate Array) mounted on the circuit board. In the present embodiment, the control circuit 21a, A switching unit 21b and an image data storage unit 21c are provided. The image data storage unit 21c may be provided outside the FPGA. Further, other semiconductor integrated circuits such as ASIC (Application Specific Integrated Circuits) may be used instead of FPGA.

The image data storage unit 21c stores the image data Da of the normal image 51 and the discharge data Db used for discharge. Of these, the discharge data Db is data used to generate a drive signal for causing the nozzle 221 of each head unit 20 to discharge ink, and the gradation values of all the pixels are maximized. It is the same data as the image data.
The image data Da and the discharge data Db are output to the switching unit 21b under the control of the control circuit 21a. From the switching unit 21b, either the image data Da or the discharge data Db is output to the head drive unit 22a of the recording head 22 according to the switching control signal output from the control circuit 21a to the switching unit 21b. ..

The control circuit 21a outputs a control signal for causing the ink ejection operation to be performed at an appropriate timing to the head drive unit 22a. Further, the control circuit 21a outputs a switching control signal to the switching unit 21b, and outputs either the image data Da or the discharge data Db from the switching unit 21b to the head drive unit 22a for each line. Let me. That is, the control circuit 21a causes the head drive unit 22a to output the image data Da from the switching unit 21b at the time of recording the normal image 51. Further, the control circuit 21a switches the switching unit 21b at the start of the discharge, starts supplying the discharge data Db to the head drive unit 22a, and starts supplying the discharge data Db to the end timing of the discharge operation. Continue supply. Further, the control circuit 21a refers to the defective nozzle data D2 stored in the second storage unit 34, and supplies a drive signal from the head drive unit 22a to the recording element having the nozzle 221 specified as the defective nozzle. The control signal is supplied to the head drive unit 22a so as not to be affected.
Since the discharge data Db has the same configuration as all image data composed of the same pixel data, the discharge data Db is read from the image data storage unit 21c and supplied to the switching unit 21b. Alternatively, a predetermined pixel data may be repeatedly supplied to the switching unit 21b under the control of the control circuit 21a.
By performing such control, the normal image 51 is recorded in the recording area of the normal image 51, while the ejection is performed outside the recording area of the normal image 51.

Next, the maintenance operation of the head unit 20 based on the defective nozzle data D2 will be described.
In the inkjet recording apparatus 1, a predetermined maintenance operation is performed when at least one of the number of defective nozzles in each head unit 20 and the arrangement of defective nozzles in the head unit 20 indicated by the defective nozzle data D2 satisfies a predetermined maintenance start condition. Is started. In the maintenance operation of the present embodiment, the second spitting and wiping are continuously performed.
Here, the maintenance start condition relating to the number of defective nozzles can be such that the number of defective nozzles indicated by the defective nozzle data D2 exceeds a predetermined first reference number. This first reference number is a defective nozzle that can suppress the deterioration of image quality to the extent that the image quality defect due to the defective nozzle in the recorded image is hardly visually recognized by supplementing the non-ejection of ink from the defective nozzle with the surrounding nozzles. It is set in the range of the number, and it is preferable to set it to a larger value in order to reduce the frequency of maintenance operations.
Further, the maintenance start condition relating to the arrangement of the defective nozzles is that the defective nozzles exceeding a predetermined second reference number are continuous, and these defective nozzles may include the late defect nozzles. Here, the second reference number is to suppress the deterioration of the image quality to the extent that the image quality defect due to the defective nozzle in the recorded image is hardly visually recognized by complementing the non-ejection of ink from a plurality of adjacent defective nozzles with the surrounding nozzles. It is set within the range of the number of continuous defective nozzles that can be used.

The second ejection of the maintenance operation is performed by ejecting ink from each nozzle 221 in a state where the head unit 20 is moved to a position facing the ink receiving portion of the maintenance unit 42. The number of times of the ink ejection operation in the second ejection is not particularly limited, but can be about 1000 times as in the case of the above-mentioned first ejection.
Here, in the second ejection, ink is ejected from all the nozzles including the defective nozzle. This is because even if the ink ejection surface 222 is contaminated with ink or ink mist due to ink ejection from a defective nozzle that can be ejected from the second ejection, wiping is performed following the second ejection to eject the ink ejection surface 222. This is because it can be cleaned. The second ejection control operation in the inkjet recording apparatus 1 is the same as the first ejection control operation except that a drive signal is supplied to the defective nozzle to eject ink.

In the maintenance operation, wiping is performed when the second discharge is completed. In this wiping, the head unit 20 is moved to a predetermined cleaning position where the cleaning roller 421 is arranged, and the cleaning roller 421 is moved so that the cleaning roller 421 comes into contact with the ink ejection surface 222 of the head unit 20. From this state, the cleaning roller 421 moves in the X direction while rotating while abutting on the ink ejection surface 222 according to the operation of the rotary motor and the transport motor of the maintenance unit 42, so that the entire ink ejection surface 222 is the cleaning roller 421. The ink and foreign matter adhering to the openings of the ink ejection surface 222 and the nozzle 221 are removed by wiping with a wiping cloth wound around the outer peripheral surface of the ink.

Since the maintenance operation of the present embodiment eliminates the blockage of the nozzle opening due to the subsequent clogging or dirt of the nozzle, there is a possibility that the maintenance operation usually restores the normal state. Is a latecomer defective nozzle, and it is rare for the initial defective nozzle to recover to a normal state.

Next, the display of the head unit replacement information prompting the replacement of the head unit 20 will be described.
In the inkjet recording apparatus 1, after the above-mentioned maintenance operation is performed and before the next normal image recording is performed, the inspection unit 43 detects a defective nozzle based on the inspection result. The latecomer defective nozzle detected as a result is a latecomer defective nozzle (hereinafter referred to as a latecomer defective fixed nozzle) that does not recover to a normal state depending on the maintenance operation. In the inkjet recording apparatus 1, at least one of the number of the latecomer defective fixed nozzles in each head unit 20 and the arrangement of the latecomer defective fixed nozzles in the head unit 20 satisfies the same predetermined condition as the condition for starting the above maintenance operation. In this case, the operation display unit 44 displays the head unit replacement information indicating that it is time to replace the head unit 20, and prompts the user to replace the head unit 20.
It should be noted that the necessity of replacing the head unit 20 may be determined based on the condition that the number and arrangement of the late-coming defective fixed nozzles are added to the number and arrangement of the initial defective nozzles.

Next, the image recording process executed in the inkjet recording apparatus 1 will be described.

FIG. 8 is a flowchart showing a control procedure of the image recording process.
In this image recording process, the image data of the normal image recorded on the recording medium M and the print job instructing the recording of the normal image are supplied from the external device 2 via the input / output interface 45 and are supplied from the second storage unit 34. It is started when it is stored in.

When the image recording process is started, the control unit 30 determines whether or not the unexecuted print job is stored in the second storage unit 34 (step S101). If it is determined that the unexecuted print job is not stored in the second storage unit 34 (“NO” in step S101), the control unit 30 ends the image recording process.

If it is determined that the unexecuted print job is stored in the second storage unit 34 (“YES” in step S101), the control unit 30 determines whether or not the defective nozzle detection start condition is satisfied. Is determined (step S102). Here, the control unit 30 satisfies the defective nozzle detection start condition when, for example, the image recording operation by the head unit 20 is performed a predetermined number of times or more after the last detection of the defective nozzle (step S103) is performed. Determine that it is.

When it is determined that the defective nozzle detection start condition is satisfied (“YES” in step S102), the control unit 30 detects the defective nozzle (step S103). That is, the control unit 30 operates the motor of the head unit moving unit 41 to move the head unit 20 in the + Z direction, and moves the inspection unit 43 between the head unit 20 and the transport belt 13. Then, the control unit 30 and the head control unit 21 discharge ink from the nozzle 221 of the recording element by outputting a drive signal from the head drive unit 22a of the recording head 22 to the recording element. Here, the number of times of ink ejection from each nozzle 221 by the control unit 30 and the head control unit 21 is set to about several times or several tens of times, whereby the ink ejection surface is not contaminated or is slightly suppressed. Be done. Further, the control unit 30 operates the motor 436 of the inspection unit 43 to move the moving unit 433 in accordance with the ejection of the ink, and causes the light emitting unit 431 and the light receiving unit 432 to synchronize with the ink ejection timing. It is operated to acquire a detection signal of light output from the light receiving unit 432. The control unit 30 detects a latecomer defective nozzle based on the acquired detection signal, generates defective nozzle data D2 (overwrites if there is already defective nozzle data D2), and stores it in the second storage unit 34. Let me.

The control unit 30 determines whether or not the maintenance start condition is satisfied (step S104). Here, the control unit 30 determines that the maintenance start condition related to the number of defective nozzles is satisfied when the number of defective nozzles indicated by the defective nozzle data D2 is larger than the first reference number. Further, the control unit 30 determines that the maintenance start condition related to the arrangement of the defective nozzles is satisfied when the defective nozzle data D2 indicates that the number of defective nozzles exceeding the second reference number is continuous. ..

When it is determined that the maintenance start condition is not satisfied (“NO” in step S104), or when it is determined in step S102 that the defective nozzle detection start condition is not satisfied (“NO” in step S102). ), The control unit 30 determines whether or not any of the head units 20 has a defective nozzle (step S105).

If it is determined that any of the head units 20 has a defective nozzle (“YES” in step S105), the control unit 30 corrects the image data based on the defective nozzle data D2 (step S106). That is, the control unit 30 refers to the defective nozzle data D2, and the image data of the normal image related to the print job so that the ink is not ejected from the defective nozzle and the non-ejection of the ink by the defective nozzle is complemented. Is corrected and stored in the second storage unit 34.

The control unit 30 starts the image recording operation related to the print job based on the image data corrected in step S106.
That is, the control unit 30 starts the transfer operation of the recording medium M by the transfer unit 10. Further, when the discharge start position of the control unit 30 and the head control unit 21 moves to the ink ejection position of each head unit 20, each nozzle 221 excluding the defective nozzle in each head unit 20 with respect to the ejection region 52. The first spitting is performed (step S107: spitting step). Further, the control unit 30 and the head control unit 21 start ink ejection from the nozzle 221 based on the corrected image data at the timing when the recording area of the normal image 51 moves to the ink ejection position of each head unit 20. The normal image 51 is recorded on the recording medium M (step S108).
If the control unit 30 determines in step S105 that all the head units 20 do not have defective nozzles (“NO” in step S105), the control unit 30 does not correct the image data related to the print job. The normal image 51 is recorded based on the above.
When the recording of one normal image 51 is completed, the control unit 30 determines whether or not the recording of all the normal images 51 instructed by the print job is completed (step S109), and the unrecorded normal image 51 is displayed. If there is, the process is shifted to step S107 (“NO” in step S109), and if the recording of all the normal images 51 is completed, the process is shifted to step S101 (“YES” in step S109). ").

If it is determined in step S104 that the maintenance start condition is satisfied (“YES” in step S104), the control unit 30 determines whether or not the maintenance flag is set to off (step S110). ).

When it is determined that the maintenance completed flag is set to off (“YES” in step S110), the control unit causes a predetermined maintenance operation to be performed. That is, the control unit 30 operates the head unit moving unit 41 to move the head unit 20 to a position facing the ink receiving unit of the maintenance unit 42. Then, the control unit 30 and the head control unit 21 eject ink from all the nozzles including the defective nozzles in the head unit 20 to the ink receiving unit to perform the second ejection (step S111: ejection disposal step). When the second discharge is completed, the control unit 30 moves the head unit 20 to a predetermined cleaning position, operates the rotary motor and the transfer motor of the maintenance unit 42, and causes the cleaning roller 421 to perform wiping (step S112). ).

When the process of step S112 is completed, the control unit 30 sets the maintenance flag to on (step S113). When the process of step S113 is completed, the control unit 30 shifts the process to step S103.

If it is determined in step S110 that the maintenance flag is set to ON (“NO” in step S110), the control unit 30 causes the operation display unit 44 to display the head unit replacement information (step). S114).
When the process of step S114 is completed, the control unit 30 ends the image recording process.

Of the image recording processes, the control for discarding in steps S107 and S111 corresponds to the dumping control by the control unit 30 and the head control unit 21.

(Modification 1)
Subsequently, a modification 1 of the above embodiment will be described. This modification is different from the above embodiment in that the detection of defective nozzles is performed only immediately after the maintenance operation. Other points are the same as those in the above embodiment.

FIG. 9 is a flowchart showing a control procedure of the image recording process according to this modification. The image recording process shown in FIG. 9 is changed so that step S102 is changed to step S115 and steps S111 and S112 are performed before step S103 in the image recording process of the above embodiment shown in FIG. , Step S110 and step S113 have been deleted. Hereinafter, the differences from the image recording process shown in FIG. 8 will be mainly described.

When the process of step S101 is completed, the control unit 30 determines whether or not the initial maintenance start condition is satisfied (step S115). Here, the control unit 30 satisfies the initial maintenance start condition when the ink is consumed by a predetermined amount or more by recording an image in the head unit 20 after the last maintenance operation (step S111 and step S112) is performed. It is determined that it is. If it is determined that the initial maintenance start condition is not satisfied (“NO” in step S115), the control unit 30 shifts the process to step S105.

If it is determined that the initial maintenance start condition is satisfied (“YES” in step S115), the control unit 30 causes the maintenance operation to be performed (step S111 and step S112). When the process of step S112 is completed, the control unit 30 detects a defective nozzle (step S103). If it is determined in step S104 that is performed after step S103 that the maintenance start condition is satisfied (“YES” in step S104), the control unit 30 displays the head unit replacement information on the operation display unit 44. Is displayed (step S114).

According to the image recording process according to the present modification, the detection of defective nozzles is performed only immediately after the maintenance operation, so that the frequency of detecting defective nozzles can be suppressed.

(Modification 2)
Subsequently, a modification 2 of the above embodiment will be described.
This modification is different from the above embodiment in that ink is not ejected from the initial defective nozzle in the second ejection. Since the initial defective nozzle is caused by a defect in the manufacturing process of the recording element, unlike a defective nozzle that occurs later due to clogging of the nozzle opening, etc., there is a possibility that the nozzle will recover to a normal nozzle depending on the ejection. Low. In view of this point, in this modification, the ink is not ejected from the initial defective nozzle in the second ejection, thereby reducing the consumption of ink due to the ejection.
Since the initial defective nozzle is not used in the first ejection and recording operation of various images (ink ejection operation is not performed), the initial defective nozzle of this modification is not always used and is fixed (recovery). Not treated as a defective nozzle. Therefore, in this modification, the initial defective nozzle may be excluded from the detection target of the defective nozzle.

As described above, the inkjet recording device 1 of the present embodiment is based on the image data of the head unit 20 having the ink ejection surface 222 provided with the opening of the nozzle 221 for ejecting ink and the normal image 51 to be recorded. Initial defective nozzle data D1 and the initial defective nozzle data D1 relating to the control unit 30 and the head control unit 21 (discharging control means) that control the ejection of ink from the nozzle 221 without ejecting ink, and the defective nozzle of the nozzle 221 that does not eject ink normally. A first storage unit 23 and a second storage unit 34 (storage unit) for storing defective nozzle data D2, respectively, are provided, and the control unit 30 and the head control unit 21 are defective among the nozzles 221 in the discharge control. It is possible to select whether or not to eject ink from the nozzle 221 specified as a defective nozzle by the nozzle data D2 (discharging control means).
As a result, in the ejection disposal control, the ink is not ejected from the defective nozzle as necessary, so that the ink or ink mist abnormally ejected from the defective nozzle adheres to the ink ejection surface 222 to contaminate the ink ejection surface 222. It can be suppressed. As a result, the ink adhering to the ink ejection surface 222 may fall on the recording medium M or the transport belt 13 to cause stains, or the ink adhering to the ink ejection surface 222 solidifies in a state where a part of the nozzle opening is closed. Therefore, it is possible to suppress the occurrence of defects such as the occurrence of new defective nozzles.

Further, the inkjet recording device 1 includes an inspection unit 43 for detecting the ink ejection state from the nozzle 221. The control unit 30 identifies a defective nozzle from the detection result by the inspection unit 43, and the identification result of the defective nozzle. The defective nozzle data D2 is stored in the second storage unit 34 based on the above (defective nozzle identifying means). With such a configuration, the defective nozzle can be accurately identified based on the ink ejection state from the nozzle 221. Further, by referring to the defective nozzle data D2 based on the detection result of the defective nozzle and determining the defective nozzle in which the ink is not ejected in the ejection discard control, an appropriate ejection reflecting the detection result of the latest defective nozzle is reflected. Discard control can be performed. For example, a nozzle that has been identified as a defective nozzle in the past but is determined to have recovered to a normal nozzle by the detection result of the latest defective nozzle is ejected with ink in the ejection disposal control and becomes a defective nozzle again. Can be suppressed. Further, the ink ejection surface 222 can be reliably suppressed by stopping the ink ejection in the ejection disposal control for the nozzle newly determined to be a defective nozzle in the detection result of the latest defective nozzle.

Further, the control unit 30 and the head control unit 21 eject ink from the nozzle 221 specified as a defective nozzle by the defective nozzle data D2 among the nozzles 221 when a predetermined condition is satisfied in the ejection disposal control. Select not to let it (discard control means). As a result, ink ejection from the defective nozzle is stopped according to predetermined conditions to suppress contamination of the ink ejection surface 222, and both suppression of generation of defective nozzles due to ejection and recovery from defective nozzles. Can be effectively realized.

Further, the control unit 30 and the head control unit 21 determine that the above-mentioned predetermined conditions are satisfied when the normal image 51 is continuously recorded after the ink is ejected by the ejection discard control (discarding control means). .. As a result, the normal image 51 can be recorded by the head unit 20 in which the contamination of the ink ejection surface 222 is suppressed. As a result, it is possible to suppress the occurrence of a problem that the ink adhering to the ink ejection surface 222 drops on the recording medium M during the recording of the normal image 51.

Further, the inkjet recording device 1 includes a cleaning roller 421 that cleans the ink ejection surface 222, and the control unit 30 causes the cleaning roller 421 to perform a cleaning operation of the ink ejection surface 222 (cleaning control means), and the control unit 30 and The head control unit 21 determines that the above-mentioned predetermined conditions are satisfied when the normal image 51 is recorded after the ink is ejected by the ejection control and before the cleaning operation is performed (discarding control means). .. As a result, the normal image 51 can be recorded by the head unit 20 in which the contamination of the ink ejection surface 222 is suppressed. As a result, it is possible to suppress the occurrence of a problem that the ink adhering to the ink ejection surface 222 drops on the recording medium M during the recording of the normal image 51.

Further, the control unit 30 and the head control unit 21 determine that the above-mentioned predetermined conditions are satisfied when the ink is ejected from the nozzle 221 outside the recording area of the normal image 51 on the recording medium M in the ejection disposal control. (Discharge control means). According to this, the ink ejection surface 222 of the head unit 20 can be maintained in a state where contamination is suppressed when the ejection is continuously performed and the normal image 51 is continuously recorded on the same recording medium M. As a result, it is possible to suppress the occurrence of a problem that the ink adhering to the ink ejection surface 222 drops on the recording medium M during the recording of the normal image 51.

Further, the control unit 30 and the head control unit 21 can perform a plurality of different types of discharge control (first and second discharge), and are predetermined among the plurality of types of discharge control. When the discharge control (first discharge) is performed, it is determined that the above-mentioned predetermined conditions are satisfied (discharge control means). As a result, when the ink ejection surface 222 is not contaminated, the ink is ejected from the defective nozzle in the ejection disposal control, and the defective nozzle can be restored to the normal nozzle.

Further, the first storage unit 23 for storing the initial defective nozzle data D1 related to the initial defective nozzle is provided integrally with the head unit 20. Thereby, when the head unit 20 is replaced, the defective nozzle of the head unit 20 (that is, the initial defective nozzle) can be specified without detecting the defective nozzle of the head unit 20.

Further, the defective nozzle data D2 includes information related to the initial defective nozzle due to the initial defect of the head unit 20, and the control unit 30 and the head control unit 21 are based on the information related to the initial defective nozzle in the discharge control. Select not to eject ink from the nozzles specified as (discard control means). As a result, it is possible to suppress ink consumption by omitting ink ejection from an initial defective nozzle, which is unlikely to recover to a normal nozzle.

Further, the ink ejection control method of the inkjet recording apparatus 1 of the above embodiment includes a ejection disposal step of ejecting ink from the nozzle 221 without being based on the image data of the normal image 51 to be recorded, and is predetermined in the ejection disposal step. When the condition is satisfied, it is selected whether or not to eject ink from the nozzle 221 specified as the defective nozzle by the defective nozzle data D2 among the nozzles 221. As a result, in the ejection disposal step, the ink is not ejected from the defective nozzle as necessary, so that the ink or ink mist abnormally ejected from the defective nozzle adheres to the ink ejection surface 222 to contaminate the ink ejection surface 222. It can be suppressed.

The present invention is not limited to the above embodiment and each modification, and various modifications can be made.
For example, in the above-described embodiment and each modification, the second dumping and wiping are performed as the maintenance operation, but in the maintenance operation, instead of the second dumping or the second dumping is performed. In addition, pressure purging may be performed to forcibly eject ink from the nozzle 221. When performing pressure purging, a pressure pump may be provided in the maintenance unit 42, and the ink may be pressurized by the pressure pump at a predetermined pressure position in the ink supply path communicating with the pressure chamber of the recording element. By pressurizing the ink, the ink is forcibly ejected from the nozzle 221 of the recording element, and the clogging of the nozzle 221 is cleared. The pressure purge is performed in a state where the ink ejection surface 222 of the head unit 20 faces the ink receiving portion.
Further, after the pressure purge is followed by the wiping, the discharge may be further performed. In this case, since the ink ejection surface 222 is not normally wiped after the ejection and before the recording operation of the normal image 51, the ejection surface 222 is not contaminated by the ejection surface 222. It is preferable not to eject ink from a defective nozzle.

Further, in the above-described embodiment and each modification, as an example of the ejection disposal control, the ejection disposal control in which the ink is ejected from the normal nozzle to the outside of the recording area of the normal image 51 on the recording medium M is performed. And the second discharge control for ejecting ink from all the nozzles to the ink receiving unit has been described, but the present invention is not limited to these. For example, the discharge control may be such that during recording of the normal image 51, a small amount of ink is discharged into the recording area of the normal image 51 at a frequency that cannot be visually confirmed. .. In this ejection, the ink ejection surface 222 of the head unit 20 faces the recording medium M, so that the ink is prevented from adhering to the ink ejection surface 222 and falling onto the recording medium M. It is preferable not to eject ink from a defective nozzle.
In addition to or in place of these ejection controls, at least a part of the start condition, the number of times ink is ejected from each nozzle 221, the drive signal used for ink ejection, the target to eject ink, and the like are mutually exclusive. A plurality of different types of throw-away control may be performed. Of these multiple types of ejection control, ink is ejected at the timing when the ink ejection surface 222 is not contaminated or slightly contaminated by the ink ejected abnormally from a defective nozzle, and when the ink ejection surface 222 is later cleaned. In the discharge control that ejects ink, ink is ejected from all nozzles 221 and in the other predetermined ejection control, ink is not ejected from defective nozzles, so that contamination of the ink ejection surface 222 can be suppressed. can.

In the above embodiment and each modification, the first storage unit 23 is provided in each head unit 20 to store the initial defective nozzle data D1 related to the initial defective nozzle, but the head unit 20 is the first. The defective nozzle data D2 related to the initial defective nozzle and the late defective nozzle may be stored in the second storage unit 34 of the control unit 30 without providing the storage unit 23. In this case, the defective nozzle data D2 may be updated by detecting the initial defective nozzle when the head unit 20 is replaced. Alternatively, the defective nozzle data D2 may be generated based on the information related to the initial defective nozzle detected in advance by an external detection device and stored in the second storage unit 34.

Further, in the above-described embodiment and each modification, the inspection unit 43 measures the amount of light as a physical quantity reflecting the ejection state of the ink from the nozzle 221 and describes it by using an example of specifying a late-coming defective nozzle from the measurement result. However, it is not limited to this. For example, the defective nozzle is identified by recording a predetermined inspection image on the recording medium M, capturing the inspection image with an image reading unit such as a line sensor or an area sensor, and analyzing the imaging data obtained. Is also good. Here, the predetermined inspection image can be, for example, a line pattern composed of a plurality of lines recorded by ink ejected from each of the plurality of nozzles 221 of the head unit 20. If there is a missing line or a line that is not recorded at an appropriate position corresponding to the nozzle 221 in the imaging data obtained by imaging this line pattern, the nozzle 221 corresponding to the line is specified as a defective nozzle. can do.

Further, prior to the detection of the defective nozzle in the inspection unit 43, the ejection may be performed by each nozzle including the defective nozzle. As a result, it is possible to prevent a nozzle that easily recovers to a normal state from being determined as a defective nozzle. In this case, it is desirable to clean the ink ejection surface 222 by wiping after ejection and before detecting a defective nozzle, but the ink ejection surface 222 is not contaminated when the number of times of ejection of ink in ejection is sufficiently small. Wiping may be omitted if the contamination is slight.

Further, in the above-described embodiment and modification, the cleaning roller 421 has been described as an example of a cleaning unit for cleaning the ink ejection surface 222, but the configuration of the cleaning unit is not limited to this, and for example, foreign matter on the ink ejection surface 222 is described. It may have a blade that scrapes ink or ink.

Further, in the above-described embodiment and modification, an example of recording on a long recording medium M unwound from a roll has been described, but the present invention is not limited to this. For example, the recording medium is not limited to the one unwound from the roll, and may be, for example, the one unwound from the folded state. Further, the recording medium may be a short one such as a sheet of paper.

Further, in the above-described embodiment and each modification, the example in which the recording medium M is transported by the transport unit 10 provided with the transport belt 13 has been described, but the purpose is not limited to this, and the transport unit 10 rotates, for example. The recording medium M may be held and transported on the outer peripheral surface of the transport drum.

Further, in the above-described embodiment and each modification, the single-pass type inkjet recording apparatus 1 has been described as an example, but the present invention may be applied to an inkjet recording apparatus that records an image while scanning a recording head. good.

Although some embodiments of the present invention have been described, the scope of the invention is not limited to the embodiments described above, but includes the scope of the invention described in the claims and the equivalent scope thereof. ..

The present invention can be used for an ink jet recording device and an ink ejection control method for an inkjet recording device.

1 Inkjet recording device 2 External device 10 Transport unit 11 Drive roller 12 Driven roller 13 Transport belt 20 Head unit 21 Head control unit 21a Control circuit 21b Switching unit 21c Image data storage unit 22 Recording head 22a Head drive unit 221 Nozzle 222 Ink ejection surface 23 First storage unit 30 Control unit 31 CPU
32 RAM
33 ROM
34 Second storage unit 41 Head unit moving unit 42 Maintenance unit 421 Cleaning roller 43 Inspection unit 431 Light emitting unit 432 Light receiving unit 433 Moving unit 434 Moving belt 435a, 435b Roller 436 Motor 437 Linear encoder 44 Operation display unit 45 Input / output interface 46 Bus 51 Normal image 52 Discharge area 52Y, 52M, 52C, 52K Discharge image by color D1 Initial defective nozzle data D2 Defective nozzle data Da Normal image image data Db Discharge data L Optical axis M Recording medium

Claims (13)

An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
Equipped with
The discharge control means is used in the discharge control.
Ri selectable der whether ink is ejected from a nozzle which is identified as a defective nozzle by the defective nozzle information of the nozzle,
When a predetermined condition is satisfied, ink is not ejected from the nozzle specified as the defective nozzle by the defective nozzle information among the nozzles, and the nozzle is specified as the defective nozzle among the nozzles. Ink is ejected from each nozzle except the existing nozzle.
An inkjet recording device that ejects ink from all the nozzles provided in the ink ejection unit when the predetermined conditions are not satisfied. An ejection state detection unit that detects the ejection state of ink from the nozzle,
A defective nozzle identification means for identifying a defective nozzle from the detection result by the discharge state detection unit and storing the defective nozzle information in the storage unit based on the specific result of the defective nozzle.
The inkjet recording apparatus according to claim 1. An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
Equipped with
The discharge control means is
In the discharge control, it is possible to select whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is used. Of these, select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
The spitting discarded controlling the predetermined condition is satisfied with the determination to Louis inkjet recording apparatus when the recording of the image is continued after the ink ejection by. An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
A cleaning unit that cleans the ink ejection surface and
A cleaning control means for cleaning the ink ejection surface by the cleaning unit, and a cleaning control means.
Equipped with
The discharge control means is
In the discharge control, it is possible to select whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is used. Of these, select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
After the ink ejection by the spitting discarded control, the cleaning operation is the predetermined condition is satisfied with the determination to Louis inkjet recording apparatus when the recording of the image is performed before that takes place. An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
Equipped with
The discharge control means is
In the discharge control, it is possible to select whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is used. Of these, select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
In the spitting discarded control, the predetermined condition is satisfied with the determination to Louis inkjet recording device when the ink is ejected from the nozzles to the outside of the recording area of the image in the recording medium. An ink ejection part having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and an ink ejection portion.
Discharge control means that controls the ejection of ink from the nozzle without being based on the image data of the image to be recorded, and the ejection control means.
A storage unit that stores defective nozzle information related to defective nozzles that do not eject ink normally among the nozzles.
Equipped with
The discharge control means is
In the discharge control, it is possible to select whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is used. Of these, select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
It is possible to perform the spitting discarded controlling a plurality of different types, Louis be determined that the predetermined condition when performing predetermined spitting abandoned control of the spitting abandoned control of the plurality of types are met Inkjet recording device. The defective nozzle information includes initial defective nozzle information related to an initial defective nozzle associated with an initial defect of the ink ejection portion.
The storage unit has an initial defective nozzle information storage unit that stores the initial defective nozzle information.
The inkjet recording device according to any one of claims 1 to 6 , wherein the initial defective nozzle information storage unit is provided integrally with the ink ejection unit. The defective nozzle information includes initial defective nozzle information related to an initial defective nozzle associated with an initial defect of the ink ejection portion.
The discharge control means according to any one of claims 1 to 7 , wherein in the discharge control, ink is selected not to be ejected from a nozzle specified as an initial defective nozzle by the initial defective nozzle information. Inkjet recording device. An inkjet having an ink ejection surface having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles. It is an ink ejection control method of a recording device and includes a ejection disposal step of ejecting ink from the nozzle without being based on the image data of the image to be recorded.
In the dumping step
Select whether or not to eject ink from the nozzle specified as the defective nozzle by the defective nozzle information among the nozzles .
When a predetermined condition is satisfied, ink is not ejected from the nozzle specified as the defective nozzle by the defective nozzle information among the nozzles, and the nozzle is specified as the defective nozzle among the nozzles. Ink is ejected from each nozzle except the existing nozzle.
An ink ejection control method for an inkjet recording device that ejects ink from all the nozzles provided in the ink ejection unit when the predetermined conditions are not satisfied. An inkjet having an ink ejection surface having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles. It is an ink ejection control method for recording devices.
Including a discharge step of ejecting ink from the nozzle without being based on the image data of the image to be recorded.
In the ejection step, it is selected whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is among the nozzles. Select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
An ink ejection control method for an inkjet recording device that determines that the predetermined condition is satisfied when an image is recorded continuously after the ink ejection in the ejection disposal step. An ink ejection unit having an ink ejection surface provided with an opening of a nozzle for ejecting ink, a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles, and the ink ejection surface. It is an ink ejection control method of an inkjet recording device equipped with a cleaning unit for cleaning.
A discharge step of ejecting ink from the nozzle without being based on the image data of the image to be recorded, and a discharge step.
A cleaning step in which the cleaning unit performs a cleaning operation on the ink ejection surface,
Including
In the ejection step, it is selected whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is among the nozzles. Select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
An ink ejection control method for an inkjet recording device that determines that the predetermined condition is satisfied when an image is recorded after the ink ejection in the ejection disposal step and before the cleaning operation is performed. An inkjet having an ink ejection surface having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles. It is an ink ejection control method for recording devices.
Including a discharge step of ejecting ink from the nozzle without being based on the image data of the image to be recorded.
In the ejection step, it is selected whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is among the nozzles. Select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
An ink ejection control method for an inkjet recording device that determines that the predetermined conditions are satisfied when ink is ejected from a nozzle outside the recording area of an image on a recording medium in the ejection disposal step. An inkjet having an ink ejection surface having an ink ejection surface provided with an opening of a nozzle for ejecting ink, and a storage unit for storing defective nozzle information related to a defective nozzle that does not eject ink normally among the nozzles. It is an ink ejection control method for recording devices.
Including a discharge step of ejecting ink from the nozzle without being based on the image data of the image to be recorded.
In the ejection step, it is selected whether or not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information among the nozzles, and when a predetermined condition is satisfied, the nozzle is among the nozzles. Select not to eject ink from the nozzle specified as a defective nozzle by the defective nozzle information.
It is possible to perform the discharge step of a plurality of different types, and an inkjet recording for determining that the predetermined condition is satisfied when performing a predetermined discharge step among the plurality of types of discharge steps. Ink ejection control method for the device.

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