EP4667223A1

EP4667223A1 - Image forming apparatus, method for controlling image forming apparatus, and program

Info

Publication number: EP4667223A1
Application number: EP25182533.7A
Authority: EP
Inventors: Takeshi Yamazaki
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 2024-06-17
Filing date: 2025-06-13
Publication date: 2025-12-24
Also published as: JP2026000074A

Abstract

Disclosed is an image forming apparatus including: a recording head that performs a print operation on a recording medium while scanning; a maintenance unit that performs a maintenance operation on the recording head with a maintenance member; and a hardware processor that controls the recording head and the maintenance unit. The hardware processor interrupts the print operation during a print job to cause the maintenance unit to perform the maintenance operation. The maintenance unit performs divided maintenance in which the recording head is divided into multiple unit regions, and the maintenance operation includes multiple divided maintenance operations performed respectively on the unit regions. The maintenance unit performs one of the divided maintenance operations at a time of a scan in which an ejection amount of nozzles of the recording head in one scan is small, the nozzles ejecting an ink onto the recording medium in the print operation.

Description

BACKGROUND OF THE INVENTION

TECHNICAL FIELD

The present invention relates to an image forming apparatus, a method for controlling an image forming apparatus, and a program.

DESCRIPTION OF RELATED ART

In an image forming apparatus that forms an image by ejecting ink, a portion of the ejected ink becomes a mist which attaches to a nozzle surface or the like, causing a nozzle to become clogged or the like. Therefore, it is necessary to periodically perform a maintenance operation on a head. However, there is a possibility that the ink that has already been ejected onto a recording medium spreads during maintenance to cause density unevenness, thereby reducing the quality of a printed image.
In this regard, for example, Japanese Patent No. 6491976 and JP 2015-74130A disclose an image forming apparatus that performs maintenance while suppressing the occurrence of density unevenness by dividing maintenance operations.

SUMMARY OF THE INVENTION

However, the apparatuses described in Japanese Patent No. 6491976 and JP 2015-74130A do not perform the maintenance operations at appropriate times according to the situations of the print operation and the divided maintenance.
The present invention has been made in consideration of the above-described problem and is intended to reduce the amount of ink that spreads during a maintenance operation in an image forming apparatus. Thus, it is an object of the present invention to suppress the occurrence of density unevenness in a standby time due to a maintenance operation performed between print jobs and reduce the influence on print quality.
To achieve at least one of the abovementioned objects, an image forming apparatus reflecting one aspect of the present invention comprises: a recording head that performs a print operation on a recording medium while scanning; a maintenance unit that performs a maintenance operation on the recording head with a maintenance member; and a hardware processor that controls the recording head and the maintenance unit, wherein: the hardware processor interrupts the print operation of the recording head during a print job to cause the maintenance unit to perform the maintenance operation, thereby executing the print job while repeating the print operation and the maintenance operation; the maintenance unit performs divided maintenance in which the recording head is divided into a plurality of unit regions, and the maintenance operation includes a plurality of divided maintenance operations that is performed respectively on the plurality of unit regions; and the hardware processor causes the maintenance unit to perform one of the plurality of divided maintenance operations in the divided maintenance at a time of a scan in which an ejection amount of nozzles of the recording head in one scan is small, the nozzles ejecting an ink onto the recording medium in the print operation.
To achieve at least one of the abovementioned objects, in the image forming apparatus described above, the maintenance unit includes a cleaning unit that cleans the maintenance member, the hardware processor causes the cleaning unit to perform a cleaning operation on the maintenance member each time the one of the plurality of divided maintenance operations is performed in the divided maintenance by the maintenance unit, and the cleaning unit includes an absorber, and cleans the maintenance member by pressing the absorber against the maintenance member.
To achieve at least one of the abovementioned objects, in the image forming apparatus described above, the maintenance unit includes a cleaning unit that cleans the maintenance member, the hardware processor causes the cleaning unit to perform a cleaning operation on the maintenance member each time the one of the plurality of divided maintenance operations is performed in the divided maintenance by the maintenance unit, and the cleaning unit includes a motor that rotates the maintenance member, and cleans the maintenance member using a centrifugal force generated by rotating the maintenance member.
To achieve at least one of the abovementioned objects, in the image forming apparatus described above, the maintenance unit includes a cleaning unit that cleans the maintenance member, the hardware processor causes the cleaning unit to perform a cleaning operation on the maintenance member each time the one of the plurality of divided maintenance operations is performed in the divided maintenance by the maintenance unit, the cleaning unit includes: a motor that rotates the maintenance member; and a liquid reservoir that stores a cleaning liquid, and the cleaning unit cleans the maintenance member by rotating the maintenance member to pass the maintenance member through the cleaning liquid in the liquid reservoir.
To achieve at least one of the abovementioned objects, a method reflecting another aspect of the present invention controls an image forming apparatus that includes: a recording head that performs a print operation on a recording medium while scanning; and a maintenance unit that performs a maintenance operation on the recording head with a maintenance member, and comprises interrupting the print operation of the recording head during a print job to cause the maintenance unit to perform the maintenance operation, thereby executing the print job while repeating the print operation and the maintenance operation, wherein: the maintenance unit performs divided maintenance in which the recording head is divided into a plurality of unit regions, and the maintenance operation includes a plurality of divided maintenance operations that is performed respectively on the plurality of unit regions; and the maintenance unit performs one of the plurality of divided maintenance operations in the divided maintenance at a time of a scan in which an ejection amount of nozzles of the recording head in one scan is small, the nozzles ejecting an ink onto the recording medium in the print operation.
To achieve at least one of the abovementioned objects, a program reflecting still another aspect of the present invention causes a computer of an image forming apparatus that includes: a recording head that performs a print operation on a recording medium while scanning; and a maintenance unit that performs a maintenance operation on the recording head with a maintenance member to execute interrupting the print operation of the recording head during a print job to cause the maintenance unit to perform the maintenance operation, thereby executing the print job while repeating the print operation and the maintenance operation, wherein: the maintenance unit performs divided maintenance in which the recording head is divided into a plurality of unit regions, and the maintenance operation includes a plurality of divided maintenance operations that is performed respectively on the plurality of unit regions; and in the interrupting the maintenance unit performs one of the plurality of divided maintenance operations in the divided maintenance at a time of a scan in which an ejection amount of nozzles of the recording head in one scan is small, the nozzles ejecting an ink onto the recording medium in the print operation.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features provided by one or more embodiments of the invention will become more fully understood from the detailed description given hereinbelow and the appended drawings which are given by way of illustration only, and thus are not intended as a definition of the limits of the present invention, wherein:

FIG. 1 is a perspective view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating a carriage according to the embodiment of the present invention and a recording head mounted on the carriage when the carriage is viewed from a bottom surface;
FIG. 3 is a plan view of the recording head according to the embodiment of the present invention when viewed from a side facing a recording medium;
FIG. 4 is a perspective view of a main portion of a cleaning section according to the embodiment;
FIG. 5 is a perspective view of a main portion of a maintenance unit of the cleaning section illustrated in FIG. 4;
FIG. 6 is a schematic diagram illustrating settings of unit regions of the recording head when divided maintenance is performed;
FIG. 7 is a schematic diagram illustrating a case where the divided maintenance is performed on the recording head illustrated in FIG. 6 with a maintenance member;
FIG. 8 is a block diagram illustrating a configuration of a control system of the image forming apparatus according to the embodiment of the present invention;
FIG. 9 is a schematic explanatory diagram illustrating a flow of a print job when the divided maintenance according to the embodiment is performed;
FIG. 10 is a schematic explanatory diagram illustrating a process of performing the divided maintenance according to the embodiment at times of scans in which an ejection amount of nozzles in one scan is small;
FIG. 11 is a schematic explanatory diagram illustrating a process of performing the divided maintenance according to the embodiment at times of scans in which the ejection amount of nozzles in one scan is small;
FIG. 12 is a schematic explanatory diagram illustrating a process of performing the divided maintenance according to the present embodiment at times of scans in which the ejection amount of nozzles in one scan is small;
FIG. 13 is a schematic diagram illustrating a case where divided maintenance is performed on a recording head with a maintenance member according to one modification example; and
FIG. 14 is a schematic diagram illustrating a case where divided maintenance is performed on a recording head with a maintenance member according to another modification example.

DETAILED DESCRIPTION

Hereinafter, an embodiment of an image forming apparatus, a method for controlling an image forming apparatus, and a program according to the present invention will be described with reference to the drawings. In the following embodiment, a case where the image forming apparatus is an inkjet recording apparatus that forms an image by an inkjet method is illustrated as an example. It should be noted that the following embodiment is provided with various limitations that are technically preferable for carrying out the present invention, but the scope of the present invention is not limited to the following embodiment and illustrated examples.

< Schematic Configuration of Inkjet Recording Apparatus >

FIG. 1 is a perspective view illustrating a schematic configuration of an inkjet recording apparatus 100, which is an embodiment of the image forming apparatus according to the present invention. An X-axis direction, a Y-axis direction, and a Z-axis direction in the present embodiment refer to directions illustrated in FIG. 1. As illustrated in FIG. 1, the inkjet recording apparatus 100 includes a conveyance device 1, a carriage 2, and a main scanning device 4. In addition, the inkjet recording apparatus 100 includes a moisturizing device 5, a cleaning section 7, and a flushing receiving section 8.
The conveyance device 1 is a device that conveys a recording medium in a conveyance direction F indicated by an arrow in FIG. 1 (a direction along the Y-axis direction in FIG. 1). As the recording medium, a recording medium having ink absorbency is assumed. For example, in the following embodiment, a case where the recording medium is a textile will be illustrated. Note that the recording medium is not limited to a textile. For example, the recording medium may be formed of various materials capable of forming an image using ink, such as paper, synthetic paper, polyvinyl chloride (PVC), a PET material, ceramic, glass, and a laminate material.
The conveyance device 1 includes a drive roller 11, a driven roller (not illustrated), a drive motor (not illustrated), and a conveyance belt 13. The drive roller 11 and the driven roller are formed of cylindrical members extending in a direction orthogonal to the conveyance direction F of the textile and are disposed in parallel to each other with a predetermined gap therebetween. The drive roller 11 is rotationally driven by the drive motor (not illustrated) constituting a conveyance drive section 131 (see FIG. 8).
The conveyance belt 13 is formed in an endless shape and is bridged between the drive roller 11 and the driven roller. When the drive roller 11 is rotationally driven by the drive motor, the conveyance belt 13 circulates between the drive roller 11 and the driven roller. Thus, the textile placed on the upper surface of the conveyance belt 13 is conveyed in the conveyance direction F. When the rotation of the drive roller 11 is stopped, the conveyance belt 13 stops circulating between the rollers, and the conveyance of the textile is stopped.
When a recording head 3 completes one-way scan in the X-axis direction, the drive motor rotates the drive roller 11 by a predetermined amount. As a result, the textile is conveyed in the conveyance direction F by a predetermined distance, and then the conveyance is stopped. Then, the recording head 3 performs a scan in a direction opposite to the main scanning direction X, and when this is completed, the drive motor rotates the drive roller 11 again by a predetermined amount. As a result, the textile is conveyed in the conveyance direction F by a predetermined distance, and then the conveyance is stopped. By repeating this operation, the conveyance drive section 131 including the drive motor performs so-called intermittent conveyance of the textile.
The main scanning device 4 is a device that conveys the carriage 2 in the X-axis direction orthogonal to the conveyance direction F. The main scanning device 4 is formed of a hollow quadrangular prism and is disposed along the X-axis direction and above the conveyance device 1 in the vertical direction (the Z-axis direction). The length of the main scanning device 4 in the X-axis direction is set to be longer than the length of the conveyance belt 13 in the X-axis direction.
A pair of guide rails 41 and 42 are disposed on one side of the main scanning device 4, a front side in FIG. 1. The guide rails 41 and 42 include a stator of a linear motor (not illustrated). A movable element (not illustrated) supported by the guide rails 41 and 42 is disposed on a surface of the carriage 2 facing the main scanning device 4. Then, by controlling a current of a coil on the stator side of the guide rails 41 and 42, the carriage 2 moves in the X-axis direction while being guided by the guide rails 41 and 42.
The carriage 2 conveyed by the main scanning device 4 is a box-shaped housing in which the recording head 3 (see FIG. 2) is mounted. In the present embodiment, it is assumed that the bottom surface (lower side in the Z-axis direction) of the carriage 2 is widely open. While the carriage 2 reciprocates over the conveyance belt 13 in the scanning (X-axis) direction, desired ink is ejected from the recording head 3. The ejected ink is dropped below the carriage 2 through the opening. As a result, an image is formed on the textile on the conveyance belt 13.
The bottom surface of the carriage 2 may not necessarily be entirely opened. For example, a slit-shaped opening having slits along the Y-axis direction at positions corresponding to the attachment positions of respective unit heads 30, which will be described later, of the recording head 3 may be appropriately provided. In this case, the recording head 3 ejects ink droplets below the carriage 2 through the slit-shaped opening.
Next, a configuration of the recording head 3 will be described with reference to FIGs. 2 and 3. FIG. 2 is a schematic diagram illustrating the carriage 2 and the recording head 3 mounted on the carriage 2 when the carriage 2 is viewed from the bottom surface. Mounted on the carriage 2, the recording head 3 performs a print operation on the textile while scanning.
The inkjet recording apparatus 100 according to the present embodiment can perform printing with nine colors of Y (yellow), Lm (light magenta), Or (orange), M (magenta), Bk (black), Bl (blue), Lk (light black), C (cyan), and Lc (light cyan). The recording head 3 according to the present embodiment is a head unit including unit heads 30Y, 30Lm, 30Or, 30M, 30Bk, 30Bl, 30Lk, 30C, and 30Lc corresponding to these nine colors. In FIG. 2, the unit heads 30Y to 30Lc mounted on the carriage 2 are indicated by two-dot chain lines. Each of the unit heads 30Y to 30Lc includes a plurality of inkjet modules 31. In the example illustrated in FIG. 2, each of the unit heads 30Y to 30Lc includes nine inkjet modules 31.
As illustrated in FIG. 2, the unit heads 30Y to 30Lc corresponding to the respective colors are aligned in the order of Y, Lm, Or, M, Bk, Bl, Lk, C, and Lc from the left in the X-axis direction. Furthermore, the nine inkjet modules 31 in each of the unit heads 30Y to 30Lc are aligned in a staggered manner in the Y-axis direction. By aligning the inkjet modules 31 in a staggered manner, ink of each color can be ejected at any position in a region covering substantially the entire width in the Y-axis direction on a side facing the bottom surface of the carriage 2. Note that in the example illustrated in FIG. 2, only the inkjet modules 31 of the leftmost unit head 30Y is illustrated, and the inkjet modules 31 of the other unit heads 30 are not illustrated. Note that the configuration of each of the unit heads 30Y to 30Lc is not limited to the example illustrated here. The recording head 3 is not limited to the one including the unit heads 30Y to 30Lc corresponding to the nine colors.
FIG. 3 is a plan view of the unit head 30 when viewed from a side facing the textile. Note that the unit heads 30Y to 30Lc constituting the recording head 3 as a head unit all have the same configuration. Therefore, in FIG. 3, the unit head 30 is also simply referred to as the recording head 3.
As illustrated in FIG. 3, each unit head 30 constituting the recording head 3 includes a plurality of inkjet heads 32 (in this embodiment, 18 inkjet heads 32). As described above, the unit head 30 according to the present embodiment includes nine inkjet modules 31. Each of the inkjet modules 31 includes two inkjet heads 32 as one set.
In the following embodiment, a surface of the recording head 3 (unit head 30) facing the textile, which is the recording medium, is referred to as a head top plate 35. The ink jet module 31 is exposed on the head top plate 35.
Each of the inkjet heads 32 has a plurality of nozzles 33 for ejecting ink. The nozzles 33 are aligned in rows in each inkjet head 32 and form a nozzle surface. In FIG. 3, the arrangement direction of the nozzles 33 is defined as a nozzle row direction Ln. In the present embodiment, the nozzle row direction Ln corresponds to the Y-axis direction (refer to FIGs. 1 and 2) orthogonal to the X-axis direction, which is the scanning movement direction of the recording head 3. The nozzle surface is substantially flush with the entire portion of the head top plate 35 other than the nozzle surface.
The inkjet head 32 ejects ink toward the textile from the nozzles 33. Thus, an image is formed on the textile. Note that the number and arrangement of the inkjet modules 31 are not limited to those described above.
Plate-shaped carriage receiving sections 43 and 44 are disposed at respective ends of the main scanning device 4 and in respective regions protruding from the conveyance device 1. The carriage receiving sections 43 and 44 are mounted so as to be substantially parallel to the conveyance belt 13 of the conveyance device 1. In a non-recording operation, the carriage 2 moves onto an upper surface of the carriage receiving section 43 disposed at one end (left side in FIG. 1) of the main scanning device 4.
The moisturizing device 5 is detachably mounted below the carriage receiving section 43. The moisturizing device 5 is a device that moisturizes the nozzles 33 of each recording head 3 mounted on the carriage 2. For example, rectangular slits are provided in the carriage receiving section 43 at positions corresponding to the nozzles 33 of the inkjet heads 32 in the carriage 2. Water or a moisturizing liquid is contained inside the moisturizing device 5. Then, when the carriage 2 is moved to a position facing the moisturizing device 5 in the Z-axis direction, the nozzle surface of the recording head 3 in the carriage 2 can be moisturized by the moisturizing device 5.
The carriage receiving section 44 disposed at the other end (right side in FIG. 1) of the main scanning device 4 is provided with the cleaning section 7 and the flushing receiving section 8. The cleaning section 7 cleans at least the nozzle surface (the surface on which ejection ports of the nozzles 33 are disposed) of the recording head 3. The flushing receiving section 8 receives ink ejected from the nozzles 33 by a flushing operation. The flushing operation is appropriately performed for the purpose of preventing clogging of the nozzles 33 of the recording head 3.
Here, a configuration of the cleaning section 7 will be described with reference to FIGs. 4 and 5.
As illustrated in FIG. 4, the cleaning section 7 includes a maintenance unit 70 that performs maintenance on at least the nozzle surface of the recording head 3 in the present embodiment. The cleaning section 7 further includes a guide rail 75 extending in the Y-axis direction, a unit drive motor 76 that moves the maintenance unit 70 along the guide rail 75, and the like. The length of the guide rail 75 in the Y-axis direction is set to be equal to or larger than the length of the nozzle surface of the recording head 3 in the Y-axis direction.
FIG. 5 is a perspective view illustrating a configuration of a main portion of the maintenance unit 70. The maintenance unit 70 performs a maintenance operation on the recording head 3 and serves as a maintenance means in the present embodiment. As illustrated in FIG. 5, the maintenance unit 70 includes a wet roller 71, a roller drive motor 72, a squeeze rod 73, and a liquid reservoir 77. As described above, the recording head 3 according to the present embodiment has a nozzle surface on the surface facing the textile (the surface of the head top plate 35). The maintenance unit 70 performs a maintenance operation on a wide region of the head top plate 35 (see FIG. 3) including the nozzle surface.
The wet roller 71 is formed of, for example, a cylindrical sponge. In the present embodiment, the wet roller 71 is a maintenance member that performs a maintenance operation on the recording head 3 by wiping.
As described above, on the nozzle surface of the recording head 3, the nozzles 33 are aligned in a direction (the Y-axis direction in the present embodiment) intersecting the scanning movement direction (the X-axis direction) of the recording head 3. The wet roller 71 performs a wiping operation on the nozzle surface in the nozzle row direction Ln of the nozzles 33.
A cleaning liquid is preferably stored inside the wet roller 71. The wet roller 71 is rotatable about a shaft 711 disposed along the X-axis direction. In the present embodiment, the maintenance operation of the maintenance unit 70 is divided maintenance.
Here, the divided maintenance will be described with reference to FIG. 6. FIG. 6 is a schematic diagram illustrating the recording head 3 for explaining the divided maintenance according to the present embodiment. In FIG. 6, for illustrative purposes, the recording head 3 including four unit heads 30 is schematically illustrated for simplicity. Note that the maintenance operation is the same for the recording head 3 including the nine unit heads 30 illustrated in FIGs. 2 and 3.
In FIG. 6, a region of each unit head 30 constituting the recording head 3 on the head top plate 35 is defined as a unit region. That is, in the example illustrated in FIG. 6 and the like, the recording head 3 is divided into four unit regions Ar1, Ar2, Ar3, and Ar4 corresponding to the respective unit heads 30. Note that it is not essential that one unit region corresponds to one unit head 30. For example, one unit head 30 may be divided into a plurality of unit regions, or two or more unit heads 30 may be defined as one unit region.
In the present embodiment, the maintenance unit 70 performs divided maintenance in which a divided maintenance operation is performed on each unit region. Therefore, the length of the wet roller 71 in the X-axis direction is set to a length that can cover at least the width of one unit region of the nozzle surface of the recording head 3 in the X-axis direction.
However, in the divided maintenance, it is preferable that the divided maintenance operation is performed so that the maintenance area overlaps the adjacent unit region. Therefore, as illustrated in FIG. 7, the length of the wet roller 71 according to the present embodiment in the X-axis direction is longer than the width of one unit region in the X-axis direction. Thus, the divided maintenance operation can be performed so that the maintenance area overlaps a portion of the adjacent unit region. In FIG. 7, the maintenance area is shown in white when the divided maintenance operation is performed on the unit region Ar1. Ink or dirt wiped by the wet roller 71 may remain in a streak in a region where the end portion of the wet roller 71 passes. By performing the divided maintenance operation with the maintenance area overlapping the adjacent unit region, it is possible to eliminate such a streaky stain residue.
The wet roller 71 is rotated by the roller drive motor 72 in the same direction as the movement direction of the maintenance unit 70 in the Y-axis direction. In FIG. 5, a direction in which the maintenance unit 70 moves is defined as a direction A" indicated by a thick arrow. Furthermore, in FIG. 5, a rotation direction of the wet roller 71 is defined as a direction "B". As a result, the wet roller 71 comes into contact with the recording head 3, which relatively moves with respect to the maintenance unit 70, in the counter direction. Therefore, the wet roller 71 can strongly wipe the nozzle surface of the recording head 3.
The liquid reservoir 77 is disposed below the wet roller 71 in the Z-axis direction. A cleaning liquid is stored in the liquid reservoir 77. The lower portion of the wet roller 71 is immersed in this cleaning liquid, and when the wet roller 71 is rotated, the cleaning liquid is scraped up by the wet roller 71 Thus, the wet roller 71 cleans the nozzle surface of the recording head 3 while supplying the cleaning liquid to the nozzle surface of the recording head 3.
The roller drive motor 72, the liquid reservoir 77 that stores the cleaning liquid, and the like constitute a cleaning means (cleaning unit) that cleans the wet roller 71 in the present embodiment. That is, the roller drive motor 72 rotates the wet roller 71 to pass the wet roller 71 through the cleaning liquid in the liquid reservoir 77, thereby cleaning the wet roller 71.
The squeeze rod 73 includes an axis substantially parallel to the axis of the wet roller 71. The squeeze rod 73 is disposed adjacent to the wet roller 71 in such a manner as to be able to be pressed against and separated from the wet roller 71. When the wet roller 71 is rotated while the squeeze rod 73 is pressed against the wet roller 71, ink and the cleaning liquid attached to the wet roller 71 are squeezed out and removed from the wet roller 71. In the present embodiment, the squeeze rod 73 also functions as a cleaning means (cleaning unit) that cleans the wet roller 71.
The flushing receiving section 8 includes, for example, an endless belt made of a material capable of absorbing ink ejected from the nozzles 33 of the inkjet head 32 of the recording head 3. The flushing operation is performed while the carriage 2 is positioned above the flushing receiving section 8 during a non-recording operation. Thus, ink can be ejected from the nozzles 33 to be absorbed by the belt of the flushing receiving section 8.
The belt of the flushing receiving section 8 is wound around, for example, three rollers (not illustrated). One of the rollers is disposed at a position where the roller is immersed in a cleaning liquid stored in a tank (not illustrated). Therefore, as the belt rotates along the three rollers, a portion of the belt is immersed in the cleaning liquid, and the ink attached to the belt is cleaned by the cleaning liquid.
In the present embodiment, an example in which the flushing receiving section 8 includes a tank has been described, but the present invention is not limited thereto. For example, a configuration may be adopted in which the tank is not provided and the ink absorbed during the flushing operation is removed by a squeezing roller or the like.

< Configuration of Control System of Inkjet Recording Apparatus >

Next, a configuration of a control system of the inkjet recording apparatus 100 according to the present embodiment is described with reference to FIG. 8. FIG. 8 is a block diagram illustrating a control configuration of the inkjet recording apparatus 100. As illustrated in FIG. 8, the inkjet recording apparatus 100 includes a controller (hardware processor) 9 and a storage section 93. The inkjet recording apparatus 100 further includes an operation and display part 96 and an input/output interface 97. In addition, the inkjet recording apparatus 100 includes a head drive section 301, a conveyance drive section 131, and a main scanning device drive section 401. These components such as the controller 9 are connected to each other via, for example, a bus.
The controller 9 includes a computer including a processor 91 such as a central processing unit (CPU) and a memory 92 such as a read only memory (ROM) and a random-access memory (RAM).
The storage section 93 includes a nonvolatile memory or the like and includes a program storage section 94 that stores various programs and the like, and a data storage section 95. The storage section 93 may include a hard disk drive or the like as a mass storage device. The data storage section 95 may include a nonvolatile memory such as a flash memory, a removable portable storage medium such as a memory card, or the like.
In the controller 9, the processor 91 reads a necessary program such as a system program stored in the program storage section 94, develops the program in an operating area of the memory 92, controls the operation of each component in cooperation with the program developed in the memory 92, and executes various processes. The controller 9 controls at least the operation of the recording head 3 and the operation of the maintenance unit 70. That is, the controller 9 interrupts a print operation of the recording head 3 in the middle of a series of print jobs to cause a maintenance operation to be performed. Thus, the controller 9 causes the inkjet recording apparatus 100 to execute a series of print jobs while repeating the print operation and the maintenance operation.
The operation and display part 96 includes, for example, a liquid crystal display (LCD). The operation and display part 96 may include an organic electroluminescence display (organic ELD), another flat display, or the like. The operation and display part 96 displays a setting screen or the like for performing various settings related to printing of the inkjet recording apparatus 100 in response to a display instruction from the controller 9. In addition, a touch screen is integrally formed in the operation and display part 96. The operation and display part 96 includes a plurality of keys and also functions as an input section that receives a key operation based on a user's touch operation. The operation and display part 96 receives a user's input of various instructions and data such as characters and numbers. Information received by the operation and display part 96 is output to the controller 9.
The input/output interface 97 is connected to an external device 200 such as a personal computer (PC). The interface 97 receives a job from the external device 200 and outputs the job to the controller 9.
The head drive section 301 drives each inkjet head 32 of the recording head 3 mounted in the carriage 2. As a result, ink is ejected from each nozzle 33, and an image is formed on the textile on the conveyance belt 13. The head drive section 301 and the inkjet heads 32 constitute the recording head 3.
The conveyance drive section 131 includes a drive motor (not illustrated). When the drive motor of the conveyance drive section 131 operates under the control of the controller 9, the drive roller 11 is rotated, and the textile is conveyed by the conveyance belt 13.
The main scanning device drive section 401 moves the carriage 2 held by the guide rails 41 and 42 in the X-axis direction by controlling the current of the coil provided on the stator side of the guide rails 41 and 42.
Further, in the present embodiment, the controller 9 controls the maintenance operation for the nozzle surface of the recording head 3 by the cleaning section 7. Normally, the maintenance operation for the recording head 3 is performed periodically at a predetermined time interval. The controller 9 causes the cleaning section 7 to start the maintenance operation in accordance with the predetermined periodic maintenance interval MD. Then, the controller 9 controls the maintenance operation for the recording head 3 by the maintenance unit 70. Furthermore, in the present embodiment, the controller 9 causes the maintenance operation to be performed as appropriate, not only at times corresponding to the periodic maintenance interval MD. Here, the control of the maintenance operation of the cleaning section 7 (maintenance unit 70) by the controller 9 will be described in detail.
The data storage section 95 stores, for example, a table defining the maintenance interval MD. The controller 9 determines the execution interval of the maintenance operation and the like with reference to these pieces of information stored in the storage section 95.
In addition, normally, when a print job is started, divided maintenance operations m1 and m2 ... are performed in this order from the unit region located at the end of the recording head 3 at a predetermined time interval. For example, FIG. 9 is a schematic explanatory diagram for explaining a normal maintenance operation performed at the predetermined maintenance interval MD. FIG. 9 illustrates an example in which the unit regions constituting the recording head 3 are unit regions α, β, and γ in this order from the end. In this case, the divided maintenance operation m1 is performed on the unit region α, and the divided maintenance operation m2 is performed on the unit region β. Then, the divided maintenance operation m3 is performed on the unit region γ. Then, after a unit maintenance interval md, returning to the unit region α, the divided maintenance operation m4 is performed.
For example, in the example illustrated in FIG. 9, the divided maintenance operations m1, m2, and m3 are performed on the three unit regions α, β, and γ during one maintenance interval MD. Here, it is assumed that the unit regions α, β, and γ respectively correspond to the unit heads 30. Further, for example, it is assumed that the unit regions α, β, and γ are regions corresponding to the unit heads 30 that respectively eject Y (yellow), M (magenta), and C (cyan) ink.
When the divided maintenance operations are respectively performed on the unit regions α, β, and γ illustrated in FIG. 9 as one set, the maintenance interval MD is an interval from the end of the maintenance operation for the unit region α to the start of the next maintenance operation for the unit region α.
Note that the controller 9 may change the interval at which the maintenance operation is performed according to the type of ink ejected from the recording head 3. Examples of the type of ink include "reactive dye ink," "disperse dye ink," and "acidic ink." The "reactive dye ink" is ink suitable for fabric such as cotton and rayon. The "disperse dye ink" is ink suitable for fabric such as polyester and acetate. The "acidic ink" is ink suitable for fabric such as silk. The storage section 95 stores, for example, a data table that defines the maintenance interval MD for each type of ink. For example, the "acidic ink" is relatively less likely to contaminate the recording head 3 than the other inks. For this reason, when the "acidic ink" is used, the maintenance interval MD is defined to be long.
The maintenance interval MD may be changed according to, for example, the type of textile used as the recording medium. Examples of the type of textile include polyester, cotton, blended fabrics (blended fabrics of chemical fibers and natural fibers, blended fabrics of natural fibers and natural fibers, and the like), and silk. In addition, the recording medium is not limited to textiles, and may be various types of paper, film, or the like. When various types of recording medium are used, the maintenance interval MD may be changed according to the type of recording medium or the like. In any case, the data storage section 95 stores a table or the like that defines a suitable maintenance interval MD corresponding to each condition. The controller 9 refers to the information stored in the storage section 95 to suitably set the maintenance interval MD.
In addition, in the present embodiment, the controller 9 causes the maintenance unit 70 to perform the divided maintenance operations at times of scans in which the ejection amount of nozzles in one scan with respect to the textile in a print operation is small. Whether the ejection amount is small is determined relatively by the controller 9.
During the divided maintenance operation, the print operation is stopped and a standby mode is entered. Since the divided maintenance operation is performed in the middle of a print job, ink has already been ejected onto the textile. During the standby time, this ink spreads on the textile, which may cause density unevenness and deteriorate print quality. The density unevenness becomes more noticeable as a large amount of ink is ejected onto the textile immediately before the divided maintenance operation.
In this regard, at a time when the ejection amount of nozzles with respect to the textile is small, the amount of ink ejected onto the textile is also small. Therefore, it is considered that the ink spread in the standby time during the divided maintenance operation is relatively small, and the density unevenness is unlikely to occur. The controller 9 determines whether it is a time when the ejection amount of ink is small based on, for example, print job data.
Furthermore, as described above, the recording head 3 according to the present embodiment forms an image with a plurality of inks respectively having a plurality of colors. It is preferable that the controller 9 causes the maintenance unit 70 to perform the divided maintenance operation for one of the plurality of colors forming the image at a time of a scan in which the ejection amount of the ink corresponding to the color is small. That is, for example, the controller 9 monitors print job data as needed, and when there is a scan in which the ejection amount of ink of a certain color is small, the controller causes a divided maintenance operation to be performed on the unit region that includes the unit head 30 corresponding to the color.
For example, when there is a scan in which the ejection amount of ink of M (magenta) is small, the following control is performed. That is, the controller 9 controls each component of the apparatus so that the divided maintenance operation of the maintenance unit 70 is performed on the unit region β corresponding to the unit head 30M that ejects the ink of M (magenta). Furthermore, for example, when there is a scan in which the ejection amount of ink of C (cyan) is small, the following control is performed. That is, the controller 9 controls each component of the apparatus so that the divided maintenance operation of the maintenance unit 70 is performed on the unit region γ corresponding to the unit head 30C that ejects the ink of C (cyan).
The unit region on which the divided maintenance operation is performed at a time of a scan in which the ejection amount of the ink of M (magenta) is small is not limited to the unit region β corresponding to the unit head 30M that ejects the ink of M (magenta). The unit regions forming one recording head 3 may be sequentially subjected to the maintenance regardless of the color having a small ink ejection amount. For example, when the divided maintenance operations are to be performed in the order of the unit regions α, β, and γ, suppose that the next divided maintenance operation will be performed on the unit region α. In this case, even when the color having a small ink ejection amount is M (magenta), which corresponds to the unit region β, the divided maintenance operation may be performed on the unit region α as in the maintenance order.
In addition, the maintenance operation is not limited to being periodically performed at a constant interval. For example, when the controller 9 determines that there is a scan in which the ejection amount of ink is small, the controller 9 may perform control such that the print operation of the recording head 3 is interrupted to be followed by the maintenance operation of the maintenance unit 70. Also in this case, the controller 9 may determine whether it is a time when the ejection amount of ink is small for a color or for the entire print operation.
Furthermore, when the maintenance operation of the maintenance unit 70 is a periodic maintenance operation performed at a predetermined time interval, the controller 9 may perform control as follows. That is, the controller 9 controls the print operation of the recording head 3 so as to perform printing with a smaller ink ejection amount than the original ink ejection amount in the scan immediately before the periodic maintenance operation is performed. Accordingly, it is possible to perform the maintenance operation with a smaller ink ejection amount than the original amount. Then, after the periodic maintenance operation is completed, the controller 9 causes the recording head 3 to perform a print operation with the remaining ejection amount.
That is, when the total number of ejections in one scan (the ejection amount of the nozzles) is set to 100%, the controller 9 causes the print operation to be performed with, for example, 50% of the total number of ejections in the scan immediately before the periodic maintenance operation. Then, the controller 9 controls the print operation of the recording head 3 so as to perform printing with 50% of the total number of ejections, which corresponds to the difference, after completion of the maintenance operation. In this case, the conveyance of the textile in the conveyance direction (Y-axis direction) is performed after the printing with the difference is performed. Thus, print operations are divided so that the number of ejections (the ejection amount of the nozzles) before and after the maintenance operation is 100%. As a result, the maintenance operation can be performed with a small ink ejection amount. The extent to which the print operations are divided before and after the maintenance operation may be defined as appropriate. It is not necessary that the extent is 50% each before and after the maintenance operation. For example, the print operations may be divided so as to be 30% before the maintenance operation and 70% after the maintenance operation. Note that the print quality decreases when the ink spreads and the density unevenness occurs in the standby time during the maintenance operation. For this reason, when the maintenance operation is performed with the ink ejection amount as small as possible, the ink spreads less and the density unevenness or the like can be suppressed. From this viewpoint, it is preferable that the number of ejections (the ejection amount of the nozzles) before the maintenance operation is set to 50% or less.
In addition, the controller 9 causes the maintenance unit 70 to perform a cleaning operation each time the maintenance operation (divided maintenance operation) is performed on one unit region. The cleaning operation is performed, for example, by the roller drive motor 72 rotating the wet roller 71 to pass the wet roller 71 through the cleaning liquid in the liquid reservoir 77. The cleaning operation is also performed by pressing the squeeze rod 73 against the wet roller 71, and the like.
Upon completion of the maintenance operation of the maintenance unit 70, the controller 9 causes the cleaning operation to be performed on the wet roller 71 in parallel with the print operation. As illustrated in FIG. 1, the maintenance unit 70 is disposed in a region different from a print region of the recording head 3. Therefore, while the print operation is being performed, the cleaning operation on the wet roller 71 can be performed in parallel with the print operation in preparation for the next maintenance operation. Thus, the wet roller 71 can be cleaned before the ink or the like removed from the recording head 3 solidifies, which is preferable.
The controller 9 causes the flushing receiving section 8 to suitably perform the flushing operation on the nozzles 33 of the inkjet head 32. The controller 9 determines that the flushing operation is necessary, for example, when an ejection failure of the nozzle surface of the recording head 3 is not sufficiently recovered even by the maintenance operation of the cleaning section 7.

< Behavior and Controlling Method of Inkjet Recording Apparatus >

Next, control of the print operation of the recording head 3 and the maintenance operation of the maintenance unit 70 performed by the controller 9 will be mainly described with reference to FIGs. 9 to 12.
In the present embodiment, the controller 9 interrupts the print operation of the recording head 3 in the middle of a series of print jobs by the recording head 3 to cause the maintenance unit 70 to perform the maintenance operation. As a result, the print operation and the maintenance operation are repeated.
The maintenance operation of the maintenance unit 70 is, as described above, the divided maintenance in which the recording head 3 is divided into a plurality of unit regions and a divided maintenance operation is performed on each unit region. Normally, when a print job is started and a predetermined print operation is performed by the recording head 3, the maintenance operation is started. FIG. 9 illustrates an example in which the controller 9 determines that it is the time to start the maintenance operation when a print operation of p1 is performed. Note that the p1 may be the duration of the print operation or may be set by the amount of printed letters or images.
First, a basic flow of the maintenance operation will be described with reference to FIG. 9.
At the starting time of the maintenance operation, the controller 9 interrupts the print operation. For regular maintenance performed periodically, the maintenance unit 70 performs the divided maintenance operation m1 on the first unit region α. For example, when the recording head 3 is constituted by the unit regions α, β, and γ, the unit region α is a region positioned at the end During the divided maintenance operation, the controller 9 moves the recording head 3 so that the unit region α comes to a position corresponding to the wet roller 71.
Next, the roller drive motor 72 is operated to rotate the wet roller 71 in the direction B. At the same time, the unit drive motor 76 is operated to move the maintenance unit 70 in the direction A in the Y-axis direction. As a result, the wet roller 71 is pressed against the recording head 3, which relatively moves with respect to the maintenance unit 70, from the counter direction. Then, the nozzle surface of the recording head 3 is wiped by the wet roller 71, and dirt such as ink is removed. In the present embodiment, the wet roller 71 is longer than the width of the unit region α or the like in the X-axis direction. For this reason, as illustrated in FIG. 9, when the divided maintenance operation m1 is performed on the unit region, a region overlapping with a portion of the adjacent unit region is also wiped. The controller 9 performs control such that, for example, the divided maintenance operation m1 ends within 30 seconds.
Upon completion of the divided maintenance operation m1, the controller 9 moves the recording head 3 to the print region and causes the recording head 3 to perform a print operation of p2. The print operation of p2 is performed during a unit maintenance interval md1. The maintenance interval MD is defined as a cycle consisting of performing all the divided maintenance operations on the unit regions α, β, and γ that constitute the recording head 3 and then waiting for the start of the next divided maintenance operations on the unit regions α, β, and γ. In the example illustrated in FIG. 9, a case where the maintenance interval MD is about 30 minutes is illustrated. The divided maintenance operation for each unit region is performed at a time interval obtained by substantially equally dividing the maintenance interval MD. For example, when the maintenance interval MD is about 30 minutes as illustrated in FIG. 9, the unit maintenance interval md1 is about 10 minutes.
While the recording head 3 performs the print operation, the controller 9 performs the cleaning operation on the wet roller 71 to prepare the wet roller 71 for the next maintenance operation. When the unit maintenance interval md1 has elapsed, the controller 9 interrupts the print operation and moves the recording head 3 so that the unit region β comes to a position corresponding to the wet roller 71. Then, the divided maintenance operation m2 is performed on the unit region β. At this time, the overlapping region that has been wiped in the divided maintenance operation m1 is wiped again. As a result, there is no streaky stain due to a residue or the like between the unit region α and the unit region β.
Upon completion of the divided maintenance operation m2, the controller 9 similarly moves the recording head 3 to the print region and causes the recording head 3 to perform a print operation of p3. During this time, the cleaning operation is performed on the wet roller 71 similarly to the case of the divided maintenance operation m1. When a unit maintenance interval md2 has elapsed, the controller 9 interrupts the print operation and moves the recording head 3 so that the unit region γ comes to a position corresponding to the wet roller 71. Then, the divided maintenance operation m3 is performed on the unit region γ. Also in this case, the overlapping region that has been wiped in the divided maintenance operation m2 is wiped again. Thus, no streak due to a residue or the like exists between the unit region β and the unit region γ.
Upon completion of the divided maintenance operation m3, the controller 9 similarly moves the recording head 3 to the print region and causes the recording head 3 to perform a print operation of p4. When a unit maintenance interval md3 has elapsed, the controller 9 moves the recording head 3 so that the unit region α comes to the position corresponding to the wet roller 71 again. Then, the divided maintenance operation m4 is performed on the unit region α. The controller 9 thus causes the print operation and the maintenance operation to be repeatedly performed until the series of print jobs is completed. For example, in the example illustrated in FIG. 9, after the divided maintenance operation m5 for the unit region β, a print operation of p6 is performed, and the series of print jobs is completed.
In the present embodiment, the controller 9 causes the maintenance unit 70 to perform the divided maintenance operations at times of scans in which the amount of ink ejected onto the textile in one scan in a print operation is small. Hereinafter, specific processing in the present embodiment will be described with reference to FIG. 10 to FIG. 12. Note that the basic flow of a series of repeating the print operation and the maintenance operation during a series of print jobs and performing the cleaning operation after the maintenance operation is the same as that illustrated in FIG. 9.
In order to cause the divided maintenance operations to be performed at times of scans with a small ejection amount of ink, the controller 9 may perform, for example, control as illustrated in FIG. 10. That is, when the recording head 3 is constituted by the unit heads 30 that form an image with a plurality of inks respectively having a plurality of colors, the control may be performed as follows. In this case, among the colors that form the image, the controller 9 identifies a unit head 30 responsible for a color with a small ink ejection amount, for example, from the print job data. Then, the unit region corresponding to the nozzle surface of the unit head 30 is determined as the target of the divided maintenance operation.
In the example illustrated in FIG. 10, the controller 9 determines in the print operation of p1 that the ejection amount of the unit head 30 corresponding to the unit region β has decreased before the divided maintenance operation. In this case, the maintenance is performed on the unit region β in the divided maintenance operation m1 after the print operation of p1.
Furthermore, the controller 9 determines in the print operation of p2 that the ejection amount of the unit head 30 corresponding to the unit region α has decreased before the divided maintenance operation. In this case, the maintenance is performed on the unit region α in the divided maintenance operation m2 after the print operation of p2. Similarly, after the divided maintenance operation m3, the unit region including the unit head 30 corresponding to a color for which the ink ejection amount has decreased before the divided maintenance operation is the target of the divided maintenance operation.
In this case, the controller 9 does not particularly need to follow the order of the unit regions constituting the recording head 3, and the unit region corresponding to a color for which the amount of ink ejected in one scan is small is set as the maintenance target. For example, in the example illustrated in FIG. 10, the controller 9 performs the divided maintenance operations on the unit regions β, α, β, γ, and α in this order. Note that when the ejection amount of ink continues to be small for the same color, the following control may be performed. For example, when the maintenance for the same unit region continues, the controller 9 sets the unit region corresponding to a color with the second smallest ink ejection amount as the maintenance target. This may prevent the maintenance region from being lopsided.
In addition, the maintenance operation is not limited to a case where the maintenance operation is periodically performed at a predetermined interval. For example, when the controller 9 determines from print job data or the like that it is a time when the ink ejection amount is small, the controller 9 may cause the maintenance unit 70 to perform the maintenance operation. In this case, as illustrated in FIG. 11, the interval between the maintenance operations may vary. However, since the maintenance is performed as appropriate when the ink ejection amount is small, the nozzle surface can be kept in a condition suitable for printing. In addition, even when the maintenance operation is performed, it is possible to effectively suppress the occurrence of density unevenness due to the ink spread during standby.
Further, the controller 9 may actively create a state in which the ink ejection amount is small for the print operation before the maintenance operation. That is, when the maintenance operation of the maintenance unit 70 is a periodic maintenance operation performed at a predetermined time interval, the control may be performed as follows. In this case, the controller 9 controls the print operation of the recording head 3 so as to perform printing with a smaller ink ejection amount than the original ink ejection amount in the scan immediately before the periodic maintenance operation is performed.
For example, FIG. 12 illustrates an example in which a print operation is performed in the print operation p1 with an ink ejection amount that is substantially half the original ink ejection amount in the scan immediately before the maintenance operation. In this case, the controller 9 causes the recording head 3 to perform printing with the ink ejection amount corresponding to the difference from the original ink ejection amount after the end of the maintenance operation m1. The printing is performed at the same position as the position where printing was performed in the scan immediately before the maintenance operation. As illustrated in FIG. 12, in this case, the controller 9 does not convey the textile at the time when the printing has been performed with about 50% immediately before the maintenance operation. Then, after the maintenance operation, the printing is performed with the ink ejection amount corresponding to the difference, and then the conveyance of the textile in the scan is performed. Thereafter, the controller 9 controls each component of the apparatus so as to start the next print operation p2. Accordingly, it is possible to perform the maintenance operation in a state in which the amount of ink ejected in one scan is small, while keeping the interval of the maintenance operation (the maintenance interval MD of FIG. 9) constant.

< Effects >

As described above, in the inkjet recording apparatus 100, which is the image forming apparatus according to the present embodiment, the controller 9 controls the operations of the recording head 3 and the maintenance unit 70 to interrupt the print operation of the recording head 3 in the middle of a series of print jobs and perform the maintenance operation. As a result, the series of print jobs is executed while the print operation and the maintenance operation are repeated. The maintenance operation according to the present embodiment is the divided maintenance in which the recording head 3 is divided into a plurality of unit regions and a divided maintenance operation is performed on each of the plurality of unit regions. Thus, it is possible to shorten the time for one (divided) maintenance operation. During the divided maintenance operation, the print operation is stopped and a standby mode is entered. When the ink already ejected onto the recording medium spreads during the standby time, the density unevenness occurs, and the print quality deteriorates. A portion of the recording medium that has already been printed may be sent to a dryer. In this case, the density unevenness is more likely to occur due to a difference in the degree of drying. In this respect, in the present embodiment, the controller 9 causes the maintenance unit 70 to perform the divided maintenance operations at times of scans in which the amount of ink ejected onto the textile in one scan in a print operation is small. This reduces the amount of ink ejected onto the textile before the divided maintenance operation. As a result, since the amount of ink that spreads in the standby time during the divided maintenance operation is small and unnoticeable, it is possible to effectively prevent the quality of a printed image from deteriorating.
For example, when the recording head 3 forms an image with a plurality of inks respectively having a plurality of colors, the controller 9 causes the maintenance unit 70 to perform the divided maintenance operation for one of the plurality of colors forming the image at a time of a scan in which the ejection amount of the ink corresponding to the color in one scan is small.
As a result, the amount of ink of the color spread in the standby time during the divided maintenance operation can be reduced, thereby reducing the density unevenness.
Further, for example, when the maintenance operation of the maintenance unit 70 is a periodic maintenance operation performed at a predetermined time interval, the control is performed as follows. That is, the controller 9 controls the print operation of the recording head 3 so as to perform printing with a smaller ink ejection amount than the original ink ejection amount in the scan immediately before the periodic maintenance operation is performed. Then, after the periodic maintenance operation is completed, the controller 9 causes the recording head 3 to perform printing with the ink ejection amount corresponding to the difference from the original ink ejection amount. The textile is conveyed after the printing with difference is performed.
Compared with the original amount of ink, how much less amount of ink is to be ejected in the scan immediately before the maintenance operation is appropriately set. For example, the controller 9 controls the recording head 3 so as to perform printing with an ink ejection amount of 50% of the original ink ejection amount in the scan immediately before the maintenance operation is performed, and causes the recording head 3 to perform printing with an ink ejection amount of 50% of the original ink ejection amount after the periodic maintenance operation is completed.
Thus, the amount of ink ejected from the recording head 3 can be divided before and after the maintenance operation, so that the ink ejection amount before the maintenance operation can be reduced. As a result, since the amount of ink that spreads in the standby time during the maintenance operation becomes small and unnoticeable, it is possible to prevent the quality of a printed image from deteriorating.
The maintenance unit 70 according to the present embodiment includes the wet roller 71 formed of a sponge or the like as a maintenance member. In this case, the maintenance operation is performed by wiping with the wet roller 71.
By wiping the nozzle surface with the wet roller 71, it is possible to suitably remove ink or the like attached to the recording head 3.
In addition, the recording head 3 according to the present embodiment has a nozzle surface on the head top plate 35 that faces the textile, which is a recording medium. The nozzle surface is formed by the nozzles 33 for ejecting ink being aligned in rows. In the present embodiment, the nozzle surface is substantially flush with the head top plate 35 other than the nozzle surface. Ink mist or the like may be attached not only to the nozzle surface but also to the head top plate 35 in the vicinity thereof. In this respect, the maintenance unit 70 according to the present embodiment performs the maintenance operation on a region of the head top plate 35 including the nozzle surface. Therefore, when the nozzle surface is wiped, ink or the like attached to the head top plate 35 can also be removed.
Furthermore, the controller 9 according to the present embodiment causes the maintenance unit 70 to perform the divided maintenance so that the maintenance area overlaps the adjacent unit region.
Ink or dirt wiped by a maintenance member may remain in a streak in a region where an end portion of the maintenance member passes. In this respect, by performing the maintenance so that the maintenance area overlaps a portion of the adjacent unit region, it is possible to repeatedly wipe the end portion of the unit region each time the maintenance is performed. As a result, it is possible to prevent a streaky stain from remaining in the region where the end portion of the maintenance member passes.
The recording head 3 according to the present embodiment has a nozzle surface formed by the nozzles 33 being aligned in rows in a direction (the Y-axis direction) intersecting the scanning movement direction (the X-axis direction) of the recording head 3. Then, the maintenance unit 70 performs a wiping operation on the nozzle surface in the nozzle row direction Ln.
As a result, the maintenance operation can be efficiently performed without leaving an unwiped region.
The maintenance unit 70 includes a cleaning means (cleaning unit) that cleans a maintenance member such as the wet roller 71. The controller 9 causes the cleaning means to perform a cleaning operation on the maintenance member each time a divided maintenance operation for one unit region is performed in the divided maintenance of the maintenance unit 70.
For example, as in the present embodiment, when the unit region is set for each unit head 30 constituting the recording head 3, the color of the ink is different for each unit region. For this reason, when the maintenance member that has wiped a certain unit region wipes another unit region as it is, there is a concern that the ink attached to the maintenance member at the time of maintenance moves to another unit region. In this respect, by performing a cleaning operation each time a divided maintenance operation is performed, it is possible to prevent the recording head from being contaminated by the maintenance.
Furthermore, the cleaning means according to the embodiment includes a roller drive motor that rotates the wet roller 71 and the liquid reservoir 77 that stores a cleaning liquid. Cleaning is performed on the wet roller 71 by rotating the wet roller 71 to pass the wet roller 71 through the cleaning liquid in the liquid reservoir 77.
Thus, the wet roller 71 can be effectively cleaned.
Further, in the present embodiment, upon completion of the maintenance operation of the maintenance unit 70, the controller 9 causes the cleaning means to perform the cleaning operation on the wet roller 71 in parallel with the print operation.
In this way, by performing the print operation of the recording head 3 and the cleaning operation of the maintenance member in parallel, it is possible to clean the maintenance member before the next maintenance operation, and it is possible to efficiently perform the print operation and the maintenance operation.

< Modification Example >

Although an embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and it is needless to say that various modifications can be made without departing from the scope of the present invention.
For example, while the recording medium is formed of a textile in the aforementioned embodiment, the present invention is not limited thereto.
Further, for example, the number of maintenance members included in the maintenance unit 70 is not limited to one. The maintenance unit may include a plurality of maintenance members each having a width smaller than that of the target maintenance region.
Further, for example, as illustrated in FIG. 13, the maintenance member 71a may include one maintenance member that has a width smaller than that of the unit region, for example, approximately half the width of the unit region. In this case, the maintenance member reciprocates a plurality of times in the unit region while changing the position in the X-axis direction, for example. In this case, it is preferable that the maintenance member 71a moves in such a manner that the wiping areas overlap each other when the maintenance member 71a reciprocates.
Furthermore, in the above embodiment, a case where the recording head 3 has a nozzle surface formed by the nozzles 33 being aligned in rows in a direction (the Y-axis direction) intersecting the scanning movement direction (the X-axis direction) of the recording head 3 has been exemplified. However, the nozzle row direction Ln of the nozzles 33 included in the recording head 3 is not limited thereto.
In addition, the maintenance direction of the maintenance unit 70 is not limited to the nozzle row direction Ln. For example, the maintenance unit 70 may perform the wiping operation on the nozzle surface in the scanning movement direction (the X-axis direction) of the recording head 3. FIG. 14 is a schematic diagram illustrating a case where the maintenance unit 70 performs maintenance in the scanning movement direction (X-axis direction) of the recording head 3. As illustrated in FIG. 14, in this case, the maintenance member 71b is preferably formed to be longer than the nozzle surface of the recording head 3 in the Y-axis direction. Note that also in this case, maintenance may be performed on one unit region by reciprocating a maintenance member shorter than the nozzle surface in the Y-axis direction a plurality of times.
The maintenance unit 70 of the cleaning section 7 includes the wet roller 71 as a maintenance member in the aforementioned embodiment, but the present invention is not limited thereto. The cleaning section 7 only needs to have a configuration capable of cleaning the nozzle surface of the recording head 3.
For example, the maintenance unit 70 may include an elastic member as a maintenance member and may perform the maintenance operation by wiping with the elastic member. The elastic member includes, for example, a blade or the like made of silicon rubber.
Also in this case, ink and the like attached to the head top plate 35 such as the nozzle surface can be removed by wiping the nozzle surface of the recording head 3 with the elastic member such as the blade.
Further, the maintenance unit, which is the maintenance means, may perform the maintenance operation by sucking excess liquid with a suction device.
Thus, even when the maintenance unit performs wiping by a vacuum method in which ink or the like attached to the nozzle surface or the like of the recording head 3 is sucked as by a vacuum cleaner, it is possible to suitably perform maintenance on the nozzle surface or the like.
Furthermore, the cleaning means for performing the cleaning operation on the maintenance member is not limited to the example illustrated in the present embodiment. For example, the cleaning means may include an absorber and perform cleaning by pressing the absorber against the wet roller 71 or a maintenance member such as a blade.
In this case, dirt such as ink attached to the maintenance member such as the wet roller 71 is removed by being absorbed or attached to the absorber, and the maintenance member returns to a clean state.
In addition, the cleaning means may include a motor that rotates the maintenance member and performs cleaning on the maintenance member using a centrifugal force generated by rotating the maintenance member. In this case, as the motor for rotating the maintenance member, the cleaning means includes a motor that is powerful enough to generate a centrifugal force through rotation.
Furthermore, when the cleaning means includes the liquid reservoir 77 that stores a cleaning liquid, cleaning may be performed by spraying the cleaning liquid in the liquid reservoir onto the maintenance member such as the wet roller 71.
In the above-described embodiments, the configuration of the image forming apparatus (inkjet recording apparatus) has been described in detail and specifically for the purpose of describing the present invention. The image forming apparatus is not necessarily limited to one including all the described components.
The present invention is not limited to the embodiments described above and illustrated in the drawings, and various modifications can be made without departing from the spirit and scope of the invention described in the claims. Although embodiments of the present invention have been described and shown in detail, the disclosed embodiments are made for purposes of illustration and example only and not limitation. The scope of the present invention should be interpreted by terms of the appended claims.
The entire disclosure of Japanese Patent Application No. 2024-097203 filed on June 17, 2024 , is incorporated herein by reference in its entirety.

Claims

An image forming apparatus (100) comprising:
a recording head (3) that performs a print operation on a recording medium while scanning;

a maintenance unit (70) that performs a maintenance operation on the recording head (3) with a maintenance member (71); and

a hardware processor (9) that controls the recording head (3) and the maintenance unit (70), wherein:
the hardware processor (9) interrupts the print operation of the recording head (3) during a print job to cause the maintenance unit (70) to perform the maintenance operation, thereby executing the print job while repeating the print operation and the maintenance operation;

the maintenance unit (70) performs divided maintenance in which the recording head (3) is divided into a plurality of unit regions, and the maintenance operation includes a plurality of divided maintenance operations that is performed respectively on the plurality of unit regions; and

the hardware processor (9) causes the maintenance unit (70) to perform one of the plurality of divided maintenance operations in the divided maintenance at a time of a scan in which an ejection amount of nozzles (33) of the recording head (3) in one scan is small, the nozzles (33) ejecting an ink onto the recording medium in the print operation.
The image forming apparatus (100) according to claim 1, wherein
the ink includes a plurality of inks respectively having a plurality of colors,

the recording head (3) forms an image with the plurality of colors, and

the hardware processor (9) causes the maintenance unit (70) to perform the one of the plurality of divided maintenance operations in the divided maintenance for one of the plurality of colors forming the image at a time of a scan in which the ejection amount of the nozzles (33) corresponding to the one of the plurality of colors in one scan is small.
The image forming apparatus (100) according to claim 1, wherein when the maintenance operation of the maintenance unit (70) is a periodic maintenance operation performed at a predetermined time interval, the hardware processor (9):
controls the print operation of the recording head (3) such that the recording head (3)
performs printing with an ink ejection amount smaller than an original ink ejection amount in a scan immediately before the periodic maintenance operation, and

performs printing with an ink ejection amount corresponding to a difference from the original ink ejection amount in a scan immediately after the periodic maintenance operation; and

causes the recording medium to be conveyed after the printing with the ink ejection amount corresponding to the difference has been performed.
The image forming apparatus (100) according to claim 3, wherein the hardware processor (9) controls the print operation of the recording head (3) such that the recording head (3)
performs printing with an ink ejection amount that is 50% of the original ink ejection amount in the scan immediately before the periodic maintenance operation, and

performs printing with the ink ejection amount that is 50% of the original ink ejection amount in the scan immediately after the periodic maintenance operation.
The image forming apparatus (100) according to claim 1, wherein
the maintenance member (71) includes a wet sponge, and

the maintenance unit (70) performs the maintenance operation by wiping with the wet sponge.
The image forming apparatus (100) according to claim 1, wherein
the maintenance member (71) includes an elastic member, and

the maintenance unit (70) performs the maintenance operation by wiping with the elastic member.
The image forming apparatus (100) according to claim 1, wherein the maintenance unit (70) performs the maintenance operation by sucking excess liquid with a suction device.
The image forming apparatus (100) according to claim 1, wherein
the nozzles (33) for ejecting the ink are aligned in a row to form a nozzle surface on a head top plate (35) facing the recording medium, and

the maintenance unit (70) performs the maintenance operation on a region of the head top plate (35), the region containing the nozzle surface.
The image forming apparatus (100) according to claim 1, wherein the hardware processor (9) causes the maintenance unit (70) to perform the divided maintenance in such a manner that an maintenance area of the one of the plurality of divided maintenance operations performed on one of the plurality of unit regions overlaps another of the plurality of the unit regions adjacent to the one of the plurality of unit regions.
The image forming apparatus (100) according to claim 1, wherein
the recording head (3) has a nozzle surface formed by the nozzles (33) being aligned in a row in a direction intersecting a scanning movement direction of the recording head (3), and

the maintenance unit (70) performs a wiping operation on the nozzle surface in the direction in which the nozzles (33) are aligned.
The image forming apparatus (100) according to claim 1, wherein
the recording head (3) has a nozzle surface formed by the nozzles (33) being aligned in a row in a direction intersecting a scanning movement direction of the recording head (3), and

the maintenance unit (70) performs a wiping operation on the nozzle surface in the scanning movement direction of the recording head (3).
The image forming apparatus (100) according to claim 1, wherein
the maintenance unit (70) includes a cleaning unit that cleans the maintenance member (71), and

the hardware processor (9) causes the cleaning unit to perform a cleaning operation on the maintenance member (71) each time the one of the plurality of divided maintenance operations is performed in the divided maintenance by the maintenance unit (70).
The image forming apparatus (100) according to claim 1, wherein
the maintenance unit (70) includes a cleaning unit that cleans the maintenance member (71), and

when the one of the plurality of divided maintenance operations is completed by the maintenance unit (70), the hardware processor (9) causes the cleaning unit to perform a cleaning operation on the maintenance member (71) in parallel with the print operation of the recording head (3).
A method for controlling an image forming apparatus (100) that includes:
a recording head (3) that performs a print operation on a recording medium while scanning; and

a maintenance unit (70) that performs a maintenance operation on the recording head (3) with a maintenance member (71),

the method comprising interrupting the print operation of the recording head (3) during a print job to cause the maintenance unit (70) to perform the maintenance operation, thereby executing the print job while repeating the print operation and the maintenance operation, wherein:
the maintenance unit (70) performs divided maintenance in which the recording head (3) is divided into a plurality of unit regions, and the maintenance operation includes a plurality of divided maintenance operations that is performed respectively on the plurality of unit regions; and

the maintenance unit (70) performs one of the plurality of divided maintenance operations in the divided maintenance at a time of a scan in which an ejection amount of nozzles (33) of the recording head (3) in one scan is small, the nozzles (33) ejecting an ink onto the recording medium in the print operation.
A program causing a computer of an image forming apparatus (100) that includes:
a recording head (3) that performs a print operation on a recording medium while scanning; and

a maintenance unit (70) that performs a maintenance operation on the recording head (3) with a maintenance member (71)

to execute interrupting the print operation of the recording head (3) during a print job to cause the maintenance unit (70) to perform the maintenance operation, thereby executing the print job while repeating the print operation and the maintenance operation, wherein:
the maintenance unit (70) performs divided maintenance in which the recording head (3) is divided into a plurality of unit regions, and the maintenance operation includes a plurality of divided maintenance operations that is performed respectively on the plurality of unit regions; and

in the interrupting the maintenance unit (70) performs one of the plurality of divided maintenance operations in the divided maintenance at a time of a scan in which an ejection amount of nozzles (33) of the recording head (3) in one scan is small, the nozzles (33) ejecting an ink onto the recording medium in the print operation.