JPWO2017002658A1 - Inkjet recording device - Google Patents

Abstract

An ink jet recording apparatus capable of managing defective nozzles more efficiently is provided. The ink jet recording apparatus includes a recording unit provided with a plurality of nozzles for ejecting ink, and a defective nozzle that does not normally eject ink among the plurality of nozzles and is associated with an initial defective nozzle associated with an initial failure of the recording unit. A first storage unit that stores the defective nozzle information of the second, and a second storage unit that stores the second defective nozzle information related to the subsequent defective nozzle that is not specified as the initial defective nozzle by the first defective nozzle information among the defective nozzles And a storage unit.

Description

  The present invention relates to an ink jet recording apparatus.

  2. Description of the Related Art Conventionally, there is an ink jet recording apparatus that records an image by ejecting ink to a recording medium from a plurality of nozzles provided in a recording unit. In such an ink jet recording apparatus, there is a case where defective nozzles (defective nozzles) are included such that ink is not discharged to the plurality of nozzles or the ink discharge amount and discharge direction are not correct (for example, Patent Document 1). ).

  Such a defective nozzle leads to deterioration in the image quality of the recorded image. Conventionally, ink is ejected from each nozzle to detect a defective nozzle, and when a defective nozzle is detected, a pressure purge that pressurizes the ink and forcibly ejects the ink from the nozzle or wipes the nozzle surface of the recording head. There is a technology for recovering a defective nozzle to a normal state by performing a maintenance operation such as wiping to remove foreign matters and dirt. In addition, when there are many defective nozzles that do not recover to a normal state by the maintenance operation, the recording unit is replaced as a recording unit that has deteriorated.

JP 2005-7613 A

  However, the defective nozzle may include an initial defective nozzle related to the initial defect of the recording unit. Since such initial defective nozzles are not usually recovered by the above-described maintenance operation, they are the same as later defective nozzles that are caused by nozzle clogging or nozzle openings being covered with dirt or the like due to the use of the recording unit. In addition, when the maintenance operation or the replacement of the recording unit is performed, there is a problem that the efficiency of management of defective nozzles is lowered.

  An object of the present invention is to provide an ink jet recording apparatus capable of managing defective nozzles more efficiently.

In order to achieve the above object, the invention of the ink jet recording apparatus according to claim 1 comprises:
A recording unit provided with a plurality of nozzles for ejecting ink;
A first storage unit that stores first defective nozzle information related to an initial defective nozzle associated with an initial defect of the recording unit, which is a defective nozzle that does not normally discharge ink among the plurality of nozzles;
A second storage unit that stores second defective nozzle information related to a subsequent defective nozzle that is not specified as the initial defective nozzle by the first defective nozzle information among the defective nozzles;
It is characterized by having.

According to a second aspect of the present invention, in the ink jet recording apparatus of the first aspect,
The first storage unit is provided integrally with the recording unit.

The invention according to claim 3 is the ink jet recording apparatus according to claim 1 or 2,
A measurement unit that measures a physical quantity reflecting the ejection state of ink from each of the plurality of nozzles;
Detecting means for detecting the defective nozzle from the result of the measurement by the measuring unit and storing the second defective nozzle information in the second storage unit based on the detection result of the defective nozzle;
It is characterized by having.

According to a fourth aspect of the present invention, in the ink jet recording apparatus according to the third aspect,
The detecting means causes the measuring unit to measure a physical quantity reflecting an ink ejection state from a nozzle that is not specified as the initial defective nozzle by the first defective nozzle information among the plurality of nozzles, and the subsequent defective. It is characterized by detecting a nozzle.

The invention according to claim 5 is the ink jet recording apparatus according to any one of claims 1 to 4,
The first defective nozzle information is information relating to the initial defective nozzle detected by an external inspection device.

The invention according to claim 6 is the ink jet recording apparatus according to claim 3 or 4,
The first defective nozzle information is information related to the initial defective nozzle detected by an external inspection apparatus, and has higher detection accuracy than detection by the detection unit from a measurement result by the measurement unit. Yes.

The invention according to claim 7 is the inkjet recording apparatus according to any one of claims 1 to 6,
Recovery means for performing a recovery operation for recovering a normal state in which ink is normally ejected from the defective nozzles to a normal state;
Recovery control for starting the recovery operation by the recovery means based on at least one of the number of nozzles identified as the subsequent defective nozzles by the second defective nozzle information among the plurality of nozzles and the arrangement in the recording unit Means,
It is characterized by having.

The invention according to claim 8 is the ink jet recording apparatus according to any one of claims 1 to 7, wherein
The image processing apparatus includes correction means for correcting image data of an image recorded on a recording medium based on at least one of the first defective nozzle information and the second defective nozzle information.

The invention according to claim 9 is the ink jet recording apparatus according to claim 8,
The correction unit corrects image data of an image recorded on a recording medium based on the first defective nozzle information and the second defective nozzle information, and uses the first defective nozzle information among the image data. The correction for the portion corresponding to the specified initial defective nozzle and the correction for the portion corresponding to the subsequent defective nozzle specified by the second defective nozzle information are performed based on different algorithms. .

The invention according to claim 10 is the ink jet recording apparatus according to any one of claims 1 to 9,
Notification means;
The notification means that prompts replacement of the recording unit based on at least one of the number of nozzles specified as the subsequent defective nozzle by the second defective nozzle information among the plurality of nozzles and the arrangement in the recording unit Notification control means to be performed by,
It is characterized by having.

  According to the present invention, there is an effect that defective nozzles can be managed more efficiently.

1 is a diagram illustrating a schematic configuration of an ink jet recording apparatus according to an embodiment of the present invention. It is a block diagram which shows the main function structures of an inkjet recording device. It is a schematic diagram which shows the structure of a cleaning roller. It is a schematic diagram which shows the structure of a test | inspection part. It is a figure explaining the detection operation of a late defective nozzle. It is a flowchart which shows the control procedure of an image recording process. 10 is a flowchart showing a control procedure of image recording processing according to Modification 2.

  Hereinafter, embodiments of the ink jet 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 ink jet recording apparatus 1 according to an embodiment of the present invention.
FIG. 2 is a block diagram showing the main functional configuration of the inkjet recording apparatus 1.

  The inkjet recording apparatus 1 includes a transport unit 11, a connection unit 120, a head unit 12 (recording unit), a head unit lifting unit 13, a maintenance unit 14 (recovery unit), an inspection unit 15 (measurement unit), An operation display unit 16 (notification unit), an interface 17, a bus 18, a control unit 20, and the like are provided.

The transport unit 11 includes a ring-shaped transport belt 113 that is supported on the inside by two transport rollers 111 and 112 that rotate about a rotation axis that extends in the X direction in FIG. The transport unit 11 transports the recording medium M when the transport rollers 111 and 112 are rotated by a motor (not shown) and the transport belt 113 is moved while the recording medium M is placed on the transport surface of the transport belt 113. The belt 113 is conveyed in the moving direction (conveying direction; Y direction in FIG. 1). Here, the recording medium M is pulled out from the roll around which the recording medium M is wound, supplied onto the conveying belt 113, and after the image is recorded, the recording medium M is taken up by another roll. The recording medium M may be a sheet cut to a certain size. In this case, after the recording medium M is supplied onto the transport belt 113 by the paper feeding device and an image is recorded. The paper is discharged from the transport belt 113 to a predetermined paper discharge unit by the paper discharge device.
As the recording medium M, various media capable of fixing the ink ejected on the surface, such as paper, fabric, or sheet-like resin, can be used.

  The head unit 12 records an image on the recording medium M conveyed by the conveying unit 11 by ejecting ink from the nozzles based on the image data. In the ink jet recording apparatus 1 of the present embodiment, as shown in FIG. 1, four head units respectively corresponding to four colors of ink of yellow (Y), magenta (M), cyan (C), and black (K). 12 are arranged at predetermined intervals in the order of colors Y, M, C, and K from the upstream side in the transport direction of the recording medium M.

  Each head unit 12 has a plurality (seven in this embodiment) in which a plurality of recording elements are arranged in a direction intersecting the transport direction of the recording medium M (in this embodiment, a direction orthogonal to the transport direction, ie, the X direction). ) And a recording head drive unit 121 that drives the recording head 122. Each head unit 12 is provided with a first storage unit 124 integrally with the head unit 12. Each head unit 12 performs a recording operation in a state where it is attached to the connection portion 120. The connection unit 120 transmits and receives data between the head unit 12 and the control unit 20. Four connecting portions 120 are provided corresponding to the four head units 12 respectively.

Each of the recording elements included in the recording head 122 includes a pressure chamber for storing ink, a piezoelectric element provided on a wall surface of the pressure chamber, and a nozzle. When a voltage signal having a driving waveform for deforming the piezoelectric element is applied to the piezoelectric element from the recording head driving unit 121, the pressure in the pressure chamber changes according to the voltage signal, and ink is ejected from the nozzle communicating with the pressure chamber. Discharged.
The arrangement range of the recording elements included in the head unit 12 in the X direction covers the width in the X direction of an area where an image can be recorded in the recording medium M conveyed by the conveying unit 11. When recording an image, the position is fixed with respect to the transport unit 11. That is, the inkjet recording apparatus 1 is a single-pass inkjet recording apparatus.

In this head unit 12, due to processing variations at the time of nozzle formation and variations in characteristics of piezoelectric elements, some of the nozzles are defective nozzles that do not normally eject ink when the head unit 12 is manufactured. There is a case. Further, as a result of the use of the head unit 12 in the ink jet recording apparatus 1, the nozzle may become clogged or the nozzle opening may be covered with dirt or the like, resulting in a defective nozzle later.
In the present embodiment, the head unit 12 is used in which a defective nozzle (initial defective nozzle) related to an initial defect is detected after manufacturing. In this embodiment, a defective nozzle that is detected for the first time after this initial defective nozzle is referred to as a late defective nozzle.

  Detection of the initial defective nozzle is performed by an external inspection device (separate from the ink jet recording apparatus 1). For example, ink (or inspection droplets) is ejected from each nozzle of the head unit 12, and the ejected ink is photographed by the inspection apparatus from the side in the ink ejection direction to determine the ink ejection state. When ink is not detected in the shooting data, it is determined that ink is not ejected. When the ink ejection direction is bent, it is determined that the ink ejection direction is abnormal. When the ink flying speed is not normal, ink ejection is performed. It is determined that the amount is abnormal, and the nozzle for which these determinations are made is detected as an initial defective nozzle. Here, that the ink discharge direction is bent means that the ink is discharged in a direction bent with respect to the original discharge direction. As an inspection apparatus for detecting an initial defective nozzle, an apparatus capable of detecting an initial defective nozzle in which an abnormality that is difficult to detect from a measurement result by an inspection unit 15 described later is used. For example, an apparatus that can detect a minute bend in the ink discharge direction, the degree of the bend, and the degree of abnormality in the ink discharge amount is used.

  The recording head drive unit 121 includes a drive circuit that supplies a voltage signal having a drive waveform corresponding to image data to each print head 122, and a drive control circuit that supplies image data to the drive circuit at an appropriate timing. . The recording head drive unit 121 causes the recording head 122 to eject ink based on the control signal and image data supplied from the CPU 21. Specifically, when a control signal and image data are supplied from the CPU 21, the drive control circuit of the recording head drive unit 121 causes the drive circuit to output a voltage signal having a drive waveform to the piezoelectric element of the recording element of the recording head 122, An ejection operation in which an amount of ink corresponding to the gradation value of the image data is ejected from the nozzles of the recording element, or when the image data corresponds to non-ejection of ink or in an interval of a plurality of image recording operations. The recording head 122 is caused to perform a non-ejection operation that is not ejected.

  The first storage unit 124 includes a nonvolatile memory such as a flash memory or an EEPROM (Electrically Erasable Programmable Read Only Memory), and stores initial defective nozzle data D1 (first defective nozzle information) related to the initial defective nozzle. Is done. In the initial defective nozzle data D1, the initial defective nozzle is specified by the nozzle array number in the head unit 12. The initial defective nozzle data D1 indicates the degree of bending of the initial defective nozzle in the ink discharge direction and the degree of abnormality in the ink discharge amount (a fluctuation amount from a normal value). The first storage unit 124 may be configured by a ROM (Read Only Memory).

  The head unit elevating unit 13 moves a mounting member (not shown) to which the head unit 12 is mounted in a direction (Z direction in FIG. 1) perpendicular to the transport surface of the transport belt 113 according to the operation of the motor. 12 is raised or lowered in the Z direction. Four head unit elevating units 13 are provided corresponding to the four head units 12 respectively.

The maintenance unit 14 performs a maintenance operation (recovery operation) for recovering, to the normal state, nozzles that can be recovered to a normal state in which ink is normally ejected among defective nozzles of the head unit 12. The maintenance operation includes a pressure purge that forcibly ejects ink from the nozzles of the head unit 12 to eliminate clogging of the nozzles, and a wiping that wipes and cleans the nozzle surface on which the nozzles of the head unit 12 are formed. Is included.
The maintenance unit 14 has a pressure pump (not shown) that pressurizes ink at a predetermined pressure position in an ink supply path communicating with the pressure chamber of the recording element when pressure purge is performed.
Moreover, the maintenance part 14 has the cleaning roller which wipes a nozzle surface.

FIG. 3 is a schematic diagram illustrating the configuration of the cleaning roller 141.
The cleaning roller 141 is arranged such that a wiping cloth containing a predetermined chemical solution is wound around the outer peripheral surface, and the rotation axis is parallel to the Y direction. The maintenance unit 14 includes a rotation motor and a conveyance motor (not shown), and the cleaning roller 141 rotates in accordance with the operation of the rotation motor and is moved in the Z direction and the X direction in accordance with the operation of the conveyance motor. When the above-described wiping is performed, the cleaning roller 141 contacts the nozzle surface of the head unit 12 by being moved in the Z direction by the operation of the transport motor, and is transported while rotating by the operation of the rotary motor in this state. The nozzle surface of the head unit 12 is wiped by moving in the X direction according to the operation of the motor. Four cleaning rollers 141 are provided corresponding to each of the four head units 12.

  The inspection unit 15 performs a predetermined measurement operation for inspecting the ejection state of ink from each nozzle.

FIG. 4 is a schematic diagram illustrating the configuration of the inspection unit 15.
The inspection unit 15 includes a light emitting unit 151, a light receiving unit 152, a moving unit 153, a moving belt 154, rollers 155a and 155b, a motor 156, a linear encoder 157, and the like. The inspecting unit 15 irradiates light to the ink flight path from the nozzle by the light emitting unit 151, and measures the light amount of the light by the light receiving unit 152. By discriminating whether or not the measured light amount is lowered at an appropriate position according to the nozzle by the ink, the ejection state of the ink from each nozzle is inspected. For example, as shown in FIG. 4, the measurement operation by the inspection unit 15 is performed on the head unit 12 moved to the + Z direction side by the head unit elevating unit 13 from the recording operation. Alternatively, the measurement operation may be performed by moving the head unit 12 to the position of the inspection unit 15.

The light emitting unit 151 outputs light (here, visible light) in the optical axis L direction. The light receiving unit 152 detects the light output from the light emitting unit 151. The light output from the light emitting unit 151 has directivity, and most of the output light is detected by the light receiving unit 152 in the state where there is no light-shielding object, that is, ink. On the other hand, the light receiving unit 152 is narrow in a range in which the light reduction amount when the detection target ink enters the light receiving area is equal to or larger than the ratio that can be detected with respect to the total incident light amount. In the case where a positional deviation related to the rotational operation accuracy of 156 occurs, the position of the ink is determined to be wide within a range that does not deviate from the light receiving area.
The moving unit 153 is a plate-like member, and the light emitting unit 151 and the light receiving unit 152 are fixed on the plate surface. One end of the moving unit 153 is fixed to the moving belt 154.
The moving belt 154 has a ring shape and is rotationally driven by rollers 155a and 155b provided on the inner peripheral surface. The moving belt 154 moves the moving unit 153 in the X direction by being driven to rotate.
The motor 156 rotates the roller 155a. The rotational speed of the motor 156 can be appropriately changed based on a control signal from the control unit 20.
The linear encoder 157 outputs a signal indicating the movement of the moving unit 153. The linear encoder 157 is not particularly limited, but for example, a linear encoder that reads a scale with an optical sensor is used.

  The operation display unit 16 includes a display device such as a liquid crystal display and an organic EL display, and operation keys and an input device such as a touch panel disposed on the screen of the display device. The operation display unit 16 displays various information on the display device, converts a user input operation to the input device into an operation signal, and outputs the operation signal to the control unit 20.

  The interface 17 is a means for transmitting and receiving data to and from the external device 2, and is configured by any one of various serial interfaces, various parallel interfaces, or a combination thereof.

  The bus 18 is a path for transmitting and receiving signals between the control unit 20 and other components.

  The control unit 20 includes a CPU 21 (Central Processing Unit) (detection unit, recovery control unit, correction unit, notification control unit), a RAM 22 (Random Access Memory), a ROM 23, and a second storage unit 24.

  The CPU 21 reads various control programs and setting data stored in the ROM 23, stores them in the RAM 22, and executes the programs to perform various arithmetic processes. Thereby, the CPU 21 controls the overall operation of the inkjet recording apparatus 1. For example, the CPU 21 causes the head unit 12 to eject ink from the nozzles to the recording medium M based on the image data stored in the second storage unit 24 while conveying the recording medium M by the conveying unit 11. Record an image.

  The RAM 22 provides a working memory space to the CPU 21 and stores temporary data. The RAM 22 stores a maintenance completion flag that is used to determine the implementation status of the maintenance operation. Here, the maintenance completion flag is binary data represented by 1 bit. The RAM 22 may include a nonvolatile memory.

  The ROM 23 stores various control programs executed by the CPU 21 and setting data. The program includes, for example, a defective nozzle detection program for detecting a defective nozzle by operating the inspection unit 15, a maintenance program for performing a maintenance operation by the maintenance unit 14, and the corrected image data by correcting the image data. An image recording program for recording an image on the recording medium M is included. Further, the setting data includes data relating to a first reference number indicating the number of late defective nozzles serving as a reference for starting the maintenance operation, and a second reference number indicating the number of consecutive defective nozzles. In place of the ROM 23, a rewritable nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used.

  The second storage unit 24 stores subsequent defective nozzle data D2 (second defective nozzle information) related to the subsequent defective nozzles in each head unit 12 detected by the operation of the inspection unit 15. In the later defective nozzle data D <b> 2, the later defective nozzle is specified by the nozzle array number in each head unit 12. The late defective nozzle data D2 is data generated by a later defective nozzle detection operation, which will be described later, and identifies the late defective nozzles related to ink non-ejection and abnormality in the ink ejection direction. Further, the second storage unit 24 stores an image recording command and image data input from the external device 2 via the interface 17 and image data corrected by the CPU 21. As the second storage unit 24, for example, an HDD (Hard Disk Drive) is used, and a DRAM (Dynamic Random Access Memory) or the like may be used in combination.

  The external device 2 is a personal computer, for example, and supplies an image recording command, image data, and the like to the control unit 20 via the interface 17.

  Next, various operations related to management of defective nozzles in the inkjet recording apparatus 1 will be described. Here, the management of defective nozzles includes detection of subsequent defective nozzles, setting of complementary non-ejection of ink from defective nozzles by correcting image data, maintenance operation of the head unit 12, and replacement of the head unit 12. .

First, the operation of detecting a defective nozzle that is subsequently executed in the inkjet recording apparatus 1 will be described.
In the ink jet recording apparatus 1, the subsequent defective nozzle is detected when a predetermined condition is satisfied. Here, the predetermined condition can be, for example, that the recording operation by the head unit 12 is performed a predetermined number of times or more after the last defective nozzle detection operation. Alternatively, a predetermined amount or more of the ink may be consumed after the last performed defective nozzle detection operation. Further, the detection of the late defective nozzle may be started by a user instruction.

FIG. 5 is a diagram for explaining the operation of detecting a late defective nozzle.
In this figure, the position of the nozzle 123 of the recording head 122 is schematically shown in a plan view of the recording head 122 of the head unit 12 and the moving unit 153 of the inspection unit 15 as viewed from the side facing the conveying surface of the conveying belt 113. ing.

When starting the detection of a late defective nozzle, the head unit 12 is moved to the + Z direction side by the head unit elevating unit 13 than in the recording operation, and the inspection unit 15 is disposed between the head unit 12 and the conveyor belt 113. Is done. Alternatively, the head unit 12 may be moved to a position above the inspection unit 15.
Then, as shown in FIG. 5, the moving unit 153 is moved to a position facing the recording head 122 based on a signal related to measurement by the linear encoder 157. That is, the moving unit 153 is moved to a position where the optical axis L of the light output from the light emitting unit 151 and detected by the light receiving unit 152 crosses the ink flight path from the head nozzle 123. Here, the head nozzle 123 is the nozzle 123 located at the + X direction side end (left end in FIG. 5) of the recording head 122 closest to the + X direction. Subsequently, while ejecting ink from the nozzles 123 of the recording head 122 in order for a predetermined time, the light emitting unit 151 and the light receiving unit 152 moved to positions corresponding to the nozzles 123 are operated, and the amount of light by the light receiving unit 152 is reduced. Based on the measurement result, the ink ejection state is inspected. That is, when a decrease in the amount of light due to the ink is not detected at the position corresponding to the nozzle 123, 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 123, Bending in the discharge direction is detected. The nozzles 123 from which ink is ejected are sequentially changed one by one in the −X direction in FIG. 5 and change to the nozzle 123 at the end (right end in FIG. 5) of the print head closest to the −X direction. The change speed at this time is set to be constant, and the moving unit 153 is moved at a constant speed in accordance with the constant change speed.
Here, ink is not ejected from the nozzle 123 specified as the initial defective nozzle by the initial defective nozzle data D1 in the first storage unit 124, and therefore the ink ejection state is not inspected for the nozzle 123. .
In the detection of the late defective nozzle, the above operation is performed on each of the four head units 12.

As described above, the amount of light reflected by the operation of the light emitting unit 151 and the light receiving unit 152 reflects the ejection state of ink from the nozzles 123 that are not specified as the initial defective nozzles in the initial defective nozzle data D1 among the nozzles 123 of each head unit 12. And the discharge state of the ink from the nozzle 123 is inspected based on the result of the measurement. As a result of the inspection, when a non-ejection of ink or a bend in the ejection direction of the ink is detected, the corresponding nozzle is identified as a late defective nozzle. When the succeeding defective nozzle is specified, succeeding defective nozzle data D2 indicating the succeeding defective nozzle is generated based on the array number of the identified nozzle 123 in the head unit 12 and stored in the second storage unit 24.
Here, when the succeeding defective nozzle data D2 is already stored in the second storage unit 24, new succeeding defective nozzle data D2 separate from this is generated and stored. By storing separate late defective nozzle data D2 generated at different timings, it is possible to refer to the history of the occurrence status of late defective nozzles. In addition, when the history of the occurrence status of the late defective nozzle is unnecessary, the new late defective nozzle data D2 may be overwritten on the existing late defective nozzle data D2.

In addition, since it is difficult to detect the flying speed of the ink from the measurement result of the light quantity by the inspection unit 15, the subsequent defective nozzle related to the abnormal ink discharge amount is not detected. Therefore, the late defective nozzle data D2 does not specify a late defective nozzle having an abnormality in the ink ejection amount, and therefore does not include data indicating the degree of abnormality from the normal value of the ink ejection amount. Further, since the degree of ink bending cannot be detected with high accuracy from the measurement result of the light amount by the inspection unit 15, the subsequent defective nozzle data D2 does not include data indicating the degree of bending in the ink ejection direction. .
As described above, the late defective nozzle data D2 does not include information related to the degree of ejection failure, whereas the initial defective nozzle data D1 includes information related to the degree of ejection failure as described above. Yes. In addition, the type of ejection failure (defective mode) identified as a defective nozzle by the initial defective nozzle data D1 is larger than the late defective nozzle data D2. Therefore, the initial defective nozzle data D1 has higher detection accuracy of defective nozzles and a larger amount of information than the later defective nozzle data D2.

Next, correction of image data based on the initial defective nozzle data D1 and the subsequent defective nozzle data D2 will be described.
In the ink jet recording apparatus 1, when a defective nozzle is specified by at least one of the initial defective nozzle data D1 and the subsequent defective nozzle data D2, correction is performed on the image data to suppress the disturbance of the recorded image caused by the defective nozzle. After that, the image is recorded. For example, when the nozzle 123a shown in FIG. 5 is specified as a defective nozzle, the image data is corrected so that ink is not ejected from the nozzle 123a and a nozzle adjacent to the defective nozzle (the nozzle in FIG. 5). 123b) or image data is corrected so that non-ejection of ink from the defective nozzle is complemented by an increase in the amount of ink ejected from the nozzles near the defective nozzle (for example, nozzles 123b and 123c in FIG. 5). Then, ink is ejected from the head unit 12 to the recording medium M based on the corrected image data, whereby an image in which deterioration in image quality due to defective nozzles is suppressed is recorded.

  When the head unit 12 is replaced and an image is recorded by the unused head unit 12, there is no late defective nozzle in the head unit 12, so the late defective nozzle related to the head unit 12. Data D2 is reset. In addition, since the initial defective nozzle in the unused head unit 12 can be specified by the initial defective nozzle data D1 stored in the first storage unit 124 of the head unit 12, it is supplied to the head unit 12. The image data is corrected based on the initial defective nozzle data D1. Therefore, when the head unit 12 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 based on the corrected image data. To be recorded.

Next, the maintenance operation based on the initial defective nozzle data D1 and the subsequent defective nozzle data D2 will be described.
In the inkjet recording apparatus 1, when at least one of the number of succeeding defective nozzles in each head unit 12 indicated by the succeeding defective nozzle data D2 and the arrangement of the succeeding defective nozzles in the head unit 12 satisfy a predetermined condition, the maintenance unit 14 Maintenance operation consisting of pressure purge and wiping is started.
Here, the predetermined condition relating to the number of subsequent defective nozzles may be that the number of subsequent defective nozzles indicated by the subsequent defective nozzle data D2 exceeds a predetermined first reference number. The first reference number is determined by a defective nozzle that can suppress image quality deterioration to such an extent that the defective image quality due to the defective nozzle in the recorded image is hardly recognized by complementing non-ejection of ink from the defective nozzle with the surrounding nozzles. It is preferably set within a range of numbers, and a larger value is preferable in order to reduce the frequency of maintenance operations.
Further, the predetermined condition relating to the arrangement of the subsequent defective nozzles may be that defective nozzles exceeding a predetermined second reference number are continuous, and the defective nozzles are included in these defective nozzles. Here, the second reference number suppresses deterioration in image quality to the extent that image quality defects due to defective nozzles in the recorded image are hardly visually recognized by complementing non-ejection of ink from a plurality of adjacent defective nozzles with surrounding nozzles. Is set within the range of the number of consecutive defective nozzles.

In the maintenance operation, the pressure purge is performed by pressurizing the ink by the pressure pump of the maintenance unit 14 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 discharged from the nozzle 123 of the recording element, and the clogging of the nozzle 123 is eliminated. The pressure purge is performed in a state where a predetermined ink receiving portion is located below the nozzle surface of the head unit 12.
Further, when wiping is performed during the maintenance operation, the head unit 12 is moved to a predetermined cleaning position where the cleaning roller 141 is disposed, and the cleaning roller 141 is brought into contact with the nozzle surface of the head unit 12. The cleaning roller 141 is moved. From this state, the cleaning roller 141 moves in the X direction while rotating in contact with the nozzle surface according to the operation of the rotation motor and the conveyance motor of the maintenance unit 14, so that the entire nozzle surface is moved to the outer peripheral surface of the cleaning roller 141. Ink and foreign matter adhered to the nozzle surface and the opening of the nozzle 123 by being wiped by the wound wiping cloth are removed.

  Since the maintenance operation of the present embodiment is to eliminate the clogging of the nozzle opening due to nozzle clogging or dirt that occurred later, there is a possibility that the maintenance operation usually recovers to a normal state. This is a late defective nozzle, and the initial defective nozzle rarely recovers to a normal state.

Next, display of head unit replacement information that prompts replacement of the head unit 12 will be described.
In the ink jet recording apparatus 1, after the above-described maintenance operation is performed and before the next image recording is performed, the subsequent defective nozzle is detected based on the inspection result by the inspection unit 15. The late defective nozzle detected as a result is a late defective nozzle that does not recover to a normal state depending on the maintenance operation (hereinafter referred to as a late defective fixed nozzle). In the inkjet recording apparatus 1, at least one of the number of subsequent defective fixed nozzles in each head unit 12 and the arrangement of the subsequent defective fixed nozzles in the head unit 12 satisfy the same predetermined condition as the condition for starting the maintenance operation. In such a case, the operation display unit 16 displays head unit replacement information indicating that it is time to replace the head unit 12, and prompts the user to replace the head unit 12.
It may be determined whether or not the head unit 12 needs to be replaced based on a condition in which the number and arrangement of the initial defective nozzles are added to the number and arrangement of the late defective fixed nozzles.

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

FIG. 6 is a flowchart showing the control procedure of the image recording process.
In this image recording process, image data of an image to be recorded on the recording medium M and an image recording command for instructing recording of the image are supplied from the external device 2 via the interface 17 and stored in the second storage unit 24. Will be started.

  When the image recording process is started, the CPU 21 determines whether or not an unexecuted image recording command is stored in the second storage unit 24 (step S1). When it is determined that an unexecuted image recording command is not stored in the second storage unit 24 (“NO” in step S1), the CPU 21 ends the image recording process.

  If it is determined that an unexecuted image recording command is stored in the second storage unit 24 (“YES” in step S1), the CPU 21 satisfies the condition for starting the detection of the subsequent defective nozzle. Is determined (step S2). Here, the CPU 21 satisfies the condition for starting the detection of the subsequent defective nozzle when the image recording operation by the head unit 12 has been performed a predetermined number of times or more after the last defective nozzle detection (step S3). Is determined.

  When it is determined that the condition for starting the detection of the subsequent defective nozzle is satisfied (“YES” in step S2), the CPU 21 detects the subsequent defective nozzle (step S3). That is, the CPU 21 operates the motor of the head unit elevating unit 13 to move the head unit 12 in the + Z direction, and moves the inspection unit 15 between the head unit 12 and the conveyance belt 113. Then, the CPU 21 refers to the initial defective nozzle data D1 to supply a control signal to the recording head driving unit 121, and causes the recording head driving unit 121 to output a voltage signal having a driving waveform to the recording head 122. Ink is ejected from the nozzles 123 other than the initial defective nozzle. Further, the CPU 21 operates the light emitting unit 151 and the light receiving unit 152 in synchronization with the ink discharge timing while operating the motor 156 of the inspection unit 15 to move the moving unit 153 in accordance with the ink discharge. The light detection signal output from the light receiving unit 152 is acquired. The CPU 21 detects the subsequent defective nozzle based on the acquired detection signal, generates the subsequent defective nozzle data D <b> 2, and stores it in the second storage unit 24.

  The CPU 21 determines whether or not the number of late defective nozzles detected in each head unit 12 or the arrangement in the head unit 12 satisfies a predetermined condition (step S4). Here, the CPU 21 determines that the condition relating to the number of succeeding defective nozzles is satisfied when the number of succeeding defective nozzles indicated by the succeeding defective nozzle data D <b> 2 is greater than the first reference number stored in the ROM 23. In addition, the CPU 21 indicates that the number of defective nozzles exceeding the second reference number stored in the ROM 23 is indicated by the initial defective nozzle data D1 and the subsequent defective nozzle data D2, and the subsequent defective nozzles are indicated by these defective nozzles. When the nozzle is included, it is determined that the condition relating to the arrangement of the defective nozzle is satisfied.

  When it is determined that the number and arrangement of subsequent defective nozzles do not satisfy the predetermined condition (“NO” in step S4), or when it is determined in step S2 that the conditions for starting detection of the subsequent defective nozzle are not satisfied (“NO” in step S2), the CPU 21 determines whether any head unit 12 has a defective nozzle (step S5). That is, the CPU 21 determines whether or not a defective nozzle is specified by at least one of the initial defective nozzle data D1 and the subsequent defective nozzle data D2 related to each head unit 12.

  When it is determined that any of the head units 12 has a defective nozzle (“YES” in step S5), the CPU 21 corrects the image data based on the initial defective nozzle data D1 and the subsequent defective nozzle data D2 ( Step S6). That is, the CPU 21 refers to the initial defective nozzle data D1 and the subsequent defective nozzle data D2, and outputs an image recording command so that ink is not ejected from the defective nozzle and non-ejection of ink by the defective nozzle is complemented. Such image data is corrected and stored in the second storage unit 24.

The CPU 21 records an image based on the image data corrected in step S6 (step S7). That is, the CPU 21 supplies a control signal to a motor that drives the transport rollers 111 and 112 of the transport unit 11 and moves the transport belt 113 to transport the recording medium M. Then, the CPU 21 supplies the corrected image data and control signal to the recording head driving unit 121, and the recording head driving unit 121 outputs a voltage signal having a driving waveform at an appropriate timing according to the movement of the conveyance belt 113. By outputting to 122, ink is ejected from the nozzles of the head unit 12 onto the recording medium M conveyed by the conveying unit 11, and an image is recorded on the recording medium M.
If it is determined in step S5 that all the head units 12 do not have a defective nozzle (“NO” in step S5), the CPU 21 converts the image data related to the image recording command to the image data without correcting it. Based on this, an image is recorded.
When the process of step S7 ends, the CPU 21 shifts the process to step S1.

  When it is determined in step S4 that the number or arrangement of subsequently failed nozzles satisfies the predetermined condition (“YES” in step S4), the CPU 21 determines whether or not the maintenance completion flag is set to OFF ( Step S8).

  When it is determined that the maintenance completion flag is set to OFF (“YES” in step S8), the CPU 21 causes the maintenance unit 14 to perform a maintenance operation (step S9). That is, the CPU 21 positions a predetermined ink receiving portion below the nozzle surface of the head unit 12 and operates the pressurizing pump by the maintenance unit 14 to pressurize the ink, so that the ink is discharged from the nozzle 123 of each head unit 12. A pressure purge is performed to force the discharge. When the pressure purge is completed, the CPU 21 moves the head unit 12 to a predetermined cleaning position, operates the rotation motor and the transport motor of the maintenance unit 14, and causes the cleaning roller 141 to perform wiping.

  When the process of step S9 ends, the CPU 21 sets the maintenance completed flag to ON (step S10). When the process of step S10 ends, the CPU 21 shifts the process to step S3.

If it is determined in step S8 that the maintenance completion flag is set to ON (“NO” in step S8), the CPU 21 causes the operation display unit 16 to display the head unit replacement information (step S11). . As described above, when it is determined in step S8 that the maintenance completion flag is set to ON, the first reference number is set in any head unit 12 in step S3 even though the maintenance operation is performed in step S9. Since the number of late defective fixed nozzles exceeding the second reference number is detected, or the number of defective nozzles exceeding the second reference number is continuous and the defective nozzle includes the subsequent defective fixed nozzles, In order to prompt the replacement of the head unit 12, the operation unit 16 displays the head unit replacement information.
When the process of step S11 ends, the CPU 21 ends the image recording process.

  As described above, the inkjet recording apparatus 1 according to the present embodiment is a head unit 12 provided with a plurality of nozzles 123 that eject ink, and a defective nozzle that does not normally eject ink among the plurality of nozzles 123. A first storage unit 124 that stores initial defective nozzle data D1 related to an initial defective nozzle that accompanies an initial defect of the head unit 12, and subsequent defectives that are not identified as initial defective nozzles by the initial defective nozzle data D1 among the defective nozzles And a second storage unit 24 that stores late defective nozzle data D2 related to the nozzles. According to such a configuration, the initial defective nozzle and the subsequent defective nozzle of the head unit 12 can be easily specified by the initial defective nozzle data D1 and the subsequent defective nozzle data D2, respectively. Therefore, more efficient management of defective nozzles can be performed based on the information related to the initial defective nozzle and / or the subsequent defective nozzle or for the subsequent defective nozzle.

  Further, the first storage unit 124 is provided integrally with the head unit 12. Thereby, when the head unit 12 is replaced, a defective nozzle (that is, an initial defective nozzle) of the head unit 12 can be specified without detecting a defective nozzle of the head unit 12.

  In addition, the inkjet recording apparatus 1 includes an inspection unit 15 that measures the amount of light that reflects the ejection state of ink from each of the plurality of nozzles 123, and the CPU 21 detects a defective nozzle from the result of measurement by the inspection unit 15, Based on the detection result of the defective nozzle, the subsequent defective nozzle data D2 is stored in the second storage unit 24 (detecting means). According to such a configuration, it is possible to detect and identify the later defective nozzle in the inkjet recording apparatus 1.

  Further, the CPU 21 detects the later defective nozzle by causing the inspection unit 15 to measure the amount of light reflecting the ink ejection state from the nozzle 123 that is not specified as the initial defective nozzle by the initial defective nozzle data D1 among the plurality of nozzles 123. To do. According to such a configuration, the amount of ink consumed to detect a defective nozzle can be reduced.

  The initial defective nozzle data D1 is information related to the initial defective nozzle detected by the external inspection apparatus. According to such a configuration, it is possible to more efficiently manage defective nozzles with reference to the initial defective nozzle data D1 based on the highly accurate detection result of defective nozzles by an inspection apparatus separate from the inkjet recording apparatus 1. it can.

  The initial defective nozzle data D1 is information related to the initial defective nozzle detected by an external inspection device, and has a detection accuracy higher than that detected by the CPU 21 as a detection unit based on the measurement result by the inspection unit 25 in ink ejection. high. As a result, it is possible to identify an initial defective nozzle related to an abnormality in the ejection direction that is difficult to detect in the inkjet recording apparatus 1, and it is possible to more appropriately manage defective nozzles.

  In addition, the inkjet recording apparatus 1 includes a maintenance unit 14 that performs a maintenance operation to restore a normal state in which ink is normally ejected among defective nozzles, and the CPU 21 includes a plurality of nozzles. A maintenance operation by the maintenance unit 14 is started based on at least one of the number of nozzles 123 specified as the late defective nozzles by the late defective nozzle data D2 in 123 and the arrangement in the head unit 12 (recovery control means). As a result, the maintenance operation can be started at an appropriate timing based on at least one of the number and arrangement of the subsequent defective nozzles that may be restored to the normal state by the maintenance operation. It can be carried out.

  Further, the CPU 21 corrects the image data of the image recorded on the recording medium M based on at least one of the initial defective nozzle data D1 and the subsequent defective nozzle data D2 (correcting means). As a result, it is possible to suppress deterioration in image quality due to defective nozzles in the recorded image. Immediately after the head unit 12 is replaced, the image data is corrected based on the initial defective nozzle information stored in the first storage unit 124 without detecting a defective nozzle in the replaced head unit 12. be able to. Even when there is a defective nozzle in a defective mode (for example, bending in the ejection direction or abnormal discharge amount) that is difficult to detect in the inkjet recording apparatus 1, the inspection apparatus separate from the inkjet recording apparatus 1 When the defective nozzle in the defective mode is specified and the initial defective nozzle data D1 is generated, the image data is corrected based on the initial defective nozzle data D1, thereby corresponding to the initial defective nozzle in the image data. The portion can be corrected more appropriately. Therefore, it is possible to more effectively suppress the deterioration in image quality caused by the defective nozzle in the recorded image.

  In addition, the inkjet recording apparatus 1 includes the operation display unit 16, and the CPU 21 has at least the number of nozzles 123 specified as the succeeding defective nozzle data D <b> 2 among the plurality of nozzles 123 and the arrangement in the head unit 12. On the basis of one of them, a display prompting replacement of the head unit 12 is performed by the operation display unit 16 (notification control means). Thereby, replacement of the head unit 12 can be urged at an appropriate timing based on at least one of the number and arrangement of late defective nozzles.

(Modification 1)
Next, Modification 1 of the above embodiment will be described. The first modification differs from the above embodiment in the algorithm for correcting image data in step S6 of the image recording process shown in FIG. Other points are the same as in the above embodiment.

In the first modification, the portion corresponding to the initial defective nozzle indicated by the initial defective nozzle data D1 in the image data and the portion corresponding to the subsequent defective nozzle indicated by the subsequent defective nozzle data D2 are corrected based on different algorithms. Is done.
That is, among the initial defective nozzles, with respect to the initial defective nozzles with abnormal ejection amounts that are identified as ejection failures related to the abnormal ink ejection amounts in the initial defective nozzle data D1, the ink from the nozzles is not ejected. Instead of the correction, correction is performed to increase or decrease the ink discharge amount from the nozzle according to the shortage or excess of the discharge amount. As for the initial defective nozzles related to ink non-ejection and bending of the ink ejection direction, the ink from the initial defective nozzles is not ejected as in the above embodiment, and the amount of ink ejected from the neighboring nozzles 123 is increased. Thus, the image data is corrected so that the non-ejection is complemented. As described above, the correction for the initial defective nozzle is performed based on an algorithm that changes the correction method according to the type of discharge failure (failure mode) of each nozzle 123.
On the other hand, for late defective nozzles, based on the same algorithm as in the above embodiment, the ink from all subsequent defective nozzles is not ejected, and the amount of ink ejected from nearby nozzles is increased so that this non-ejection is complemented. Correction is performed.

  It should be noted that the correction related to the initial defective nozzle of the ejection amount abnormality is previously performed on the image data, and after the detection of the subsequent defective nozzle, the correction related to the other initial defective nozzle and the subsequent defective nozzle is added. You may make it do.

  As described above, in the inkjet recording apparatus 1 according to the first modification, the CPU 21 corrects the image data of the image recorded on the recording medium M based on the initial defective nozzle data D1 and the subsequent defective nozzle data D2, and the image Of the data, correction for the portion corresponding to the initial defective nozzle specified by the initial defective nozzle data D1 and correction for the portion corresponding to the subsequent defective nozzle data D2 are performed based on different algorithms. (Correction means). Accordingly, since it is possible to perform appropriate correction on the image data according to the difference in information amount related to the ejection failure between the initial defective nozzle data D1 and the subsequent defective nozzle data D2, the defective nozzle in the recorded image can be corrected. The resulting deterioration in image quality can be more effectively suppressed.

(Modification 2)
Next, a second modification of the above embodiment will be described. The second modification is different from the above-described embodiment in that the detection of the late defective nozzle is performed only immediately after the maintenance operation. Other points are the same as in the above embodiment.

  FIG. 7 is a flowchart showing a control procedure of image recording processing according to the second modification. The image recording process shown in FIG. 7 is changed so that step S2 is changed to step S2a and step S9 is executed before step S3 in the image recording process of the above-described embodiment shown in FIG. And step S10 is deleted. Below, it demonstrates centering on difference with the image recording process shown by FIG.

  When the process of step S1 ends, the CPU 21 determines whether or not a condition for starting the maintenance operation is satisfied (step S2a). Here, the CPU 21 determines that the condition for starting the maintenance operation is satisfied when the head unit 12 consumes a predetermined amount or more of ink by recording an image after the last maintenance operation (step S9). When it is determined that the condition for starting the maintenance operation is not satisfied (“NO” in step S2a), the CPU 21 shifts the process to step S5.

  When it is determined that the condition for starting the maintenance operation is satisfied (“YES” in step S2a), the CPU 21 causes the maintenance unit 14 to perform the maintenance operation (step S9). When the process in step S9 is completed, the CPU 21 detects a later defective nozzle (step S3). In step S4 performed after step S3, when it is determined that the number or arrangement of subsequently defective nozzles satisfies the predetermined condition (“YES” in step S4), the CPU 21 displays the head unit on the operation display unit 16. The exchange information is displayed (step S11).

  According to such an image recording process according to the second modified example, since the detection of the subsequent defective nozzle is performed only immediately after the maintenance operation, the frequency of the detection of the subsequent defective nozzle can be suppressed.

Note that the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made.
For example, in the above-described embodiment and each modification, the first storage unit 124 is provided for each head unit 12 as the recording unit, and the initial defective nozzle data D1 for the initial defective nozzles included in the recording head 122 of the head unit 12. However, instead of this, the first storage unit is provided for each recording head 122, and the initial defective nozzle included in the recording head 122 is initialized. The defective nozzle data may be stored in the first storage unit. In this case, the recording unit is configured by the recording head 122 integrally provided with the first storage unit. According to such a configuration, when some of the recording heads 122 are replaced in the head unit 12, it is possible to specify the initial defective nozzles of the replaced recording head 122 without detecting defective nozzles. .

Further, in the above-described embodiment and each modification, the second storage unit 24 has been described using an example in which the subsequent defective nozzle data D2 is stored. However, the second storage unit 24 further includes the initial defective nozzle data D1. May be stored. For example, when the head unit 12 is connected to the connection unit 120, the initial defective nozzle data D <b> 1 may be read from the first storage unit 124 by the CPU 21 and written to the second storage unit 24. Further, the initial defective nozzle data D1 may be directly written in the second storage unit 24 based on the detection result of the initial defective nozzle of the head unit 12 by an inspection device separate from the ink jet recording apparatus 1. When the initial defective nozzle data D1 and the subsequent defective nozzle data D2 are stored in the second storage unit 24 without being distinguished from each other, the initial defective nozzle data D1 and the subsequent defective nozzle data D1 stored in the second storage unit 24 are stored. By excluding the initial defective nozzle specified by the initial defective nozzle data D1 stored in the first storage unit 124 from the defective nozzle specified by the defective nozzle data D2, it is possible to specify the subsequent defective nozzle. Therefore, in step S4 of the image recording process shown in FIG. 6 and FIG. 7, the determination may be made based on the nozzle that has been identified in this way.
According to such a configuration, the image data can be corrected without accessing the first storage unit 124 in step S6 of the image recording process shown in FIGS. In this case, the second storage unit 24 constitutes a first storage unit and a second storage unit.
When the initial defective nozzle data D1 and the subsequent defective nozzle data D2 are stored in the second storage unit 24, the first storage unit that stores the initial defective nozzle data D1 in the head unit 12 or the recording head 122 is provided. It is good also as not providing.

  Further, in the above-described embodiment and each modified example, the inspection unit 15 measures the amount of light as a physical quantity that reflects the ejection state of the ink from the nozzle 123, and uses an example in which a subsequent defective nozzle is identified from the measurement result. However, it is not intended to be limited to this. For example, detection of a late defective nozzle is performed by recording a predetermined inspection image on the recording medium M, and analyzing image data obtained by imaging the inspection image by an image reading unit such as a line sensor or an area sensor. May be. Here, the predetermined inspection image may be a line pattern including a plurality of lines recorded by ink ejected from each of the plurality of nozzles 123 included in the head unit 12, for example. In the imaging data obtained by imaging this line pattern, if there is a missing line or a line that is not recorded at an appropriate position corresponding to the nozzle 123, the nozzle 123 corresponding to the line is identified as a defective nozzle. can do. In this case, the amount of light reflected by each line in the inspection image corresponds to a physical quantity reflecting the ink ejection state, and the measurement unit is configured by the image reading unit that measures the amount of light.

  Further, in the above-described embodiment and each modification, the description has been given using the example in which the maintenance operation is performed on the entire head unit 12, but instead, a part of the nozzle 123 included in each head unit 12 is used. On the other hand, a maintenance operation may be performed on the single nozzle 123. For example, flushing may be performed so that ink is ejected only from the nozzle 123 that is specified as the subsequent defective nozzle data D2 (or the subsequent defective nozzle data D2 and the initial defective nozzle data D1). In this way, a more efficient maintenance operation can be performed.

  In the above embodiment and each modified example, in the detection of the subsequent defective nozzle using the inspection unit 15, the description has been given using the example in which the ink is not ejected from the initial defective nozzle. Ink may be ejected from all the included nozzles 123 to detect defective nozzles, and the detection result obtained by removing the initial defective nozzles indicated by the initial defective nozzle data D1 may be specified as the subsequent defective nozzles.

  In the above-described embodiment and each modification, the example in which the initial defective nozzle is detected by an inspection device separate from the ink jet recording apparatus 1 has been described. However, the head unit 12 is connected to the connection portion 120 of the ink jet recording apparatus 1. After the connection, the initial defective nozzle may be detected using the inspection unit 15.

  Further, in the above-described embodiment and each modification, the description has been given using the example in which it is time to replace the head unit 12 by displaying on the operation display unit 16, but instead the head unit It is time to replace the head unit 12 to the user by turning on a lamp indicating that it is time to replace the head unit, generating a predetermined alarm sound, or sending an e-mail to a preset address. May be notified.

  In the above-described embodiment and each modification, the example in which the recording medium M is transported by the transport unit 11 including the transport belt 113 has been described. However, the present invention is not limited to this, and the transport unit 11 rotates, for example. The recording medium M may be held and transported on the outer peripheral surface of the transport drum.

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

  Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, and includes the scope of the invention described in the claims and equivalents thereof. .

  The present invention can be used in an ink jet recording apparatus.

DESCRIPTION OF SYMBOLS 1 Inkjet recording apparatus 2 External apparatus 11 Conveyance part 111,112 Conveyance roller 113 Conveyor belt 12 Head unit 120 Connection part 121 Recording head drive part 122 Recording head 123 Nozzle 124 First memory | storage part 13 Head unit raising / lowering part 14 Maintenance part 141 Cleaning Roller 15 Inspection unit 151 Light emitting unit 152 Light receiving unit 153 Moving unit 154 Moving belts 155a and 255b Roller 156 Motor 157 Linear encoder 16 Operation display unit 17 Interface 18 Bus 20 Control unit 21 CPU
22 RAM
23 ROM
24 Second storage unit D1 Initial defective nozzle data D2 Subsequent defective nozzle data L Optical axis M Recording medium

Claims (10)

A recording unit provided with a plurality of nozzles for ejecting ink;
A first storage unit that stores first defective nozzle information related to an initial defective nozzle associated with an initial defect of the recording unit, which is a defective nozzle that does not normally discharge ink among the plurality of nozzles;
A second storage unit that stores second defective nozzle information related to a subsequent defective nozzle that is not specified as the initial defective nozzle by the first defective nozzle information among the defective nozzles;
An ink jet recording apparatus comprising:   The inkjet recording apparatus according to claim 1, wherein the first storage unit is provided integrally with the recording unit. A measurement unit that measures a physical quantity reflecting the ejection state of ink from each of the plurality of nozzles;
Detecting means for detecting the defective nozzle from the result of the measurement by the measuring unit and storing the second defective nozzle information in the second storage unit based on the detection result of the defective nozzle;
The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is provided.   The detecting means causes the measuring unit to measure a physical quantity reflecting an ink ejection state from a nozzle that is not specified as the initial defective nozzle by the first defective nozzle information among the plurality of nozzles, and the subsequent defective. The inkjet recording apparatus according to claim 3, wherein a nozzle is detected.   The inkjet recording apparatus according to claim 1, wherein the first defective nozzle information is information relating to the initial defective nozzle detected by an external inspection apparatus.   The first defective nozzle information is information related to the initial defective nozzle detected by an external inspection apparatus, and has higher detection accuracy than detection by the detection unit from a measurement result by the measurement unit. The ink jet recording apparatus according to claim 3 or 4. Recovery means for performing a recovery operation for recovering a normal state in which ink is normally ejected from the defective nozzles to a normal state;
Recovery control for starting the recovery operation by the recovery means based on at least one of the number of nozzles identified as the subsequent defective nozzles by the second defective nozzle information among the plurality of nozzles and the arrangement in the recording unit Means,
An ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is provided.   8. A correction unit that corrects image data of an image recorded on a recording medium based on at least one of the first defective nozzle information and the second defective nozzle information. An ink jet recording apparatus according to claim 1.   The correction unit corrects image data of an image recorded on a recording medium based on the first defective nozzle information and the second defective nozzle information, and uses the first defective nozzle information among the image data. The correction for the portion corresponding to the specified initial defective nozzle and the correction for the portion corresponding to the subsequent defective nozzle specified by the second defective nozzle information are performed based on different algorithms. The ink jet recording apparatus according to claim 8. Notification means;
The notification means that prompts replacement of the recording unit based on at least one of the number of nozzles specified as the subsequent defective nozzle by the second defective nozzle information among the plurality of nozzles and the arrangement in the recording unit Notification control means to be performed by,
An ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is provided.

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