JP2026000074A - Image forming apparatus, control method and program for image forming apparatus - Google Patents

Abstract

[Problem] The amount of ink that spreads during maintenance operations is reduced. This prevents uneven density during standby times due to maintenance operations performed between print jobs, reducing the impact on print quality. [Solution] An inkjet recording device (100) includes a recording head (3), a maintenance unit (70), and a control unit (9) that controls the operation of the recording head (3) and the maintenance unit (70). The control unit (9) interrupts the printing operation of the recording head (3) in the middle of a series of print jobs to perform a maintenance operation. This allows the print job to be executed while repeating the printing operation and the maintenance operation. The maintenance operation is divided maintenance that is performed for each unit area of the recording head (3). The control unit (9) causes the maintenance means to perform divided maintenance at the timing of a scan in which the nozzles ejecting the smallest amount of ink per scan onto the fabric during the printing operation. [Selected Figure] Figure 9

Description

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

In image forming devices that form images by ejecting ink, some of the ejected ink turns into a mist and adheres to the nozzle surface, causing nozzle clogging and other problems. This requires periodic head maintenance. However, ink that has already been ejected onto the recording medium can spread during maintenance, causing uneven density and potentially degrading the quality of printed images.
In this regard, for example, Japanese Patent Application Laid-Open No. 2003-144999 and Japanese Patent Application Laid-Open No. 2003-144999 disclose image forming apparatuses in which maintenance operations are dispersed and performed while suppressing the occurrence of density unevenness.

Patent No. 6491976 JP 2015-74130 A

However, the devices described in Patent Documents 1 and 2 do not perform maintenance operations at appropriate times depending on the status of printing operations or split maintenance.

The present invention was made in consideration of the above-mentioned problems, and aims to reduce the amount of ink that spreads during maintenance operations in an image forming device. This prevents uneven density during the waiting time caused by maintenance operations between print jobs, thereby reducing the impact on print quality.

In order to solve the above problems, an image forming apparatus according to the present invention comprises:
an image forming apparatus comprising: a recording head that performs a printing operation on a recording medium while scanning; a maintenance unit that performs a maintenance operation on the recording head using a maintenance member; and a control unit that controls the operation of the recording head and the maintenance unit, wherein the control unit interrupts the printing operation of the recording head in the middle of a series of print jobs and causes the maintenance unit to perform the maintenance operation, thereby executing the print jobs while repeating the printing operation and the maintenance operation;
the maintenance operation by the maintenance unit is divided maintenance in which the recording head is divided into a plurality of unit areas and is performed for each of the unit areas,
The control unit is characterized in that it causes the maintenance unit to perform divided maintenance at the timing of a scan in which the nozzles ejecting ink onto the recording medium in one scan during the printing operation have a small ejection volume.

A method for controlling an image forming apparatus according to another aspect of the present invention includes:
In an image forming apparatus including a recording head that performs a printing operation on a recording medium while scanning and a maintenance unit that performs a maintenance operation on the recording head using a maintenance member, a control method for the image forming apparatus is provided, the control method comprising: interrupting the printing operation of the recording head in the middle of a series of print jobs and causing the maintenance unit to perform the maintenance operation, thereby executing the print jobs while repeating the printing operation and the maintenance operation;
the maintenance operation by the maintenance unit is divided maintenance in which the recording head is divided into a plurality of unit areas and is performed for each of the unit areas,
The maintenance unit is characterized in that divided maintenance is performed on the maintenance unit at the timing of a scan in which the nozzles discharging a small amount of ink onto the recording medium in one scan during the printing operation.

A program according to another aspect of the present invention includes:
A computer of an image forming apparatus including a recording head that performs a printing operation on a recording medium while scanning and a maintenance unit that performs a maintenance operation on the recording head using a maintenance member,
an operation control function is realized that interrupts the printing operation of the recording head in the middle of a series of print jobs and causes the maintenance unit to perform the maintenance operation;
the maintenance operation by the maintenance unit is divided maintenance in which the recording head is divided into a plurality of unit areas and is performed for each of the unit areas,
The operation control function is characterized in that it causes the maintenance unit to perform divided maintenance at the timing of a scan in which the nozzle discharging the smallest amount of ink onto the recording medium in one scan during the printing operation.

This invention reduces the amount of ink that spreads during maintenance operations. This prevents uneven density during the waiting time caused by maintenance operations between print jobs, reducing the impact on print quality.

1 is a perspective view showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention; 1 is a schematic diagram of a carriage and a recording head mounted on the carriage when the carriage according to an embodiment of the present invention is viewed from the bottom side. FIG. 1 is a plan view showing a state in which a recording head according to an embodiment of the present invention is viewed from the recording medium side. FIG. 2 is a perspective view of a main part of a cleaning unit according to the embodiment. FIG. 5 is a perspective view of a main part of a maintenance unit of the cleaning section shown in FIG. 4 . 10A and 10B are schematic diagrams showing examples of setting unit areas of a print head when performing divided maintenance. 7 is a schematic diagram of the recording head and maintenance members showing an example of a case where divided maintenance is performed on the recording head shown in FIG. 6. FIG. FIG. 2 is a block diagram showing an example of the configuration of a control system of the image forming apparatus according to the embodiment of the present invention. FIG. 10 is a schematic explanatory diagram showing an example of the flow of a print job in which divided maintenance is performed in the embodiment. 10A and 10B are schematic explanatory diagrams showing an example of processing in which divided maintenance is performed at the timing of a scan in which the ejection volume of a nozzle ejecting ink in one scan is small in an embodiment; 10A and 10B are schematic explanatory diagrams showing an example of processing in which divided maintenance is performed at the timing of a scan in which the ejection volume of a nozzle ejecting ink in one scan is small in an embodiment; 10A and 10B are schematic explanatory diagrams showing an example of processing in which divided maintenance is performed at the timing of a scan in which the ejection volume of a nozzle ejecting ink in one scan is small in an embodiment; 10A and 10B are schematic diagrams of a recording head and a maintenance member showing an example of a case where divided maintenance is performed using a maintenance member according to a modified example. 10A and 10B are schematic diagrams of a recording head and a maintenance member showing an example of a case where divided maintenance is performed using a maintenance member according to a modified example.

An embodiment of an image forming apparatus, an image forming apparatus control method, and a program according to the present invention will be described below with reference to the drawings. In the following embodiment, an example is shown in which the image forming apparatus is an inkjet recording apparatus that forms images using an inkjet system. Note that the following embodiment is subject to various limitations that are technically preferable for implementing the present invention, but the scope of the present invention is not limited to the following embodiment and illustrated example.

<General Configuration of Inkjet Recording Apparatus>
Fig. 1 is a perspective view showing a schematic configuration of an inkjet recording apparatus 100, which is one embodiment of an image forming apparatus according to the present invention. In the embodiment, the X-axis direction, the Y-axis direction, and the Z-axis direction refer to the directions shown in Fig. 1. As shown in Fig. 1, the inkjet recording apparatus 100 includes a transport device 1, a carriage 2, and a main scanning device 4. The inkjet recording apparatus 100 also includes a moisturizing device 5, a cleaning unit 7, and a flushing receiving unit 8.

The conveying device 1 is a device that conveys the recording medium in a conveying direction F (along the Y-axis direction in the figure) indicated by the arrow in the figure. The recording medium is assumed to be ink-absorbent. For example, in the following embodiment, the recording medium is illustrated as being fabric. However, the recording medium is not limited to fabric. For example, the recording medium may be made of various materials on which an image can be formed using ink, such as paper, synthetic paper, polyvinyl chloride (PVC), PET material, ceramic, glass, and laminate material.

The conveying device 1 includes a drive roller 11, a driven roller (not shown), a drive motor (not shown), and a conveying belt 13. The drive roller 11 and the driven roller are composed of cylindrical members extending in a direction perpendicular to the conveying direction F of the fabric, and are arranged parallel to each other with a predetermined distance between them. The drive roller 11 is driven to rotate by a drive motor (not shown) that constitutes the conveying drive unit 131 (see Figure 8).

The conveyor belt 13 is endless and is stretched between the drive roller 11 and the driven roller. When the drive roller 11 is driven to rotate by a drive motor, the conveyor belt 13 rotates between the drive roller 11 and the driven roller. This causes the fabric placed on the top surface of the conveyor belt 13 to be conveyed along the conveying direction F. When the drive roller 11 stops rotating, the conveyor belt 13 stops rotating between the two rollers, and the conveyance of the fabric is stopped.

When the recording head 3 has completed one one-way scan along the X-axis direction, the drive motor rotates the drive roller 11 a predetermined amount. This transports the fabric a predetermined distance in the transport direction F, and then stops driving. The recording head 3 then performs a scan in the opposite direction to the main scanning direction X, and when this is complete, the drive motor again rotates the drive roller 11 a predetermined amount. This transports the fabric a predetermined distance in the transport direction F, and then stops driving. By repeating this operation, the transport drive unit 131, which includes the drive motor, transports the fabric intermittently.

The main scanning device 4 is a device that transports the carriage 2 along the X-axis direction, which is perpendicular to the transport direction F. The main scanning device 4 is composed of a hollow rectangular pillar and is arranged along the X-axis direction above the transport device 1 in the vertical direction (Z-axis direction). The length of the main scanning device 4 in the X-axis direction is set longer than the length of the transport belt 13 in the X-axis direction.

A pair of guide rails 41 and 42 are provided on the side of the main scanning device 4 facing the viewer in the figure. These guide rails 41 and 42 are equipped with a stator of a linear motor (not shown). Furthermore, a mover (not shown) supported by the guide rails 41 and 42 is provided on the surface of the carriage 2 facing the main scanning device 4. Current control of the coils on the stator side of the guide rails 41 and 42 causes the carriage 2 to move along the X-axis direction, guided by the guide rails 41 and 42.

The carriage 2, which is transported by the main scanning device 4, is a box-shaped housing with a recording head 3 (see FIG. 2) mounted therein. In this embodiment, the carriage 2 will be described as having a wide opening on the bottom side (the lower side in the Z-axis direction). As the carriage 2 moves back and forth above the transport 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. In this way, an image is formed on the fabric on the transport belt 13.
The bottom surface of the carriage 2 does not have to be completely open. For example, slit-shaped openings along the Y-axis direction may be appropriately provided corresponding to the attachment positions of each unit head 30 (described later) of the recording head 3. In this case, the recording head 3 ejects ink droplets below the carriage 2 through the slit-shaped openings.

Next, the configuration of the recording head 3 will be described with reference to Figures 2 and 3. Figure 2 is a schematic diagram of the carriage 2 and the recording head 3 mounted on the carriage 2, as viewed from the bottom side of the carriage 2. The recording head 3 performs a printing operation on the fabric while moving in a scanning manner while mounted on the carriage 2.

The inkjet recording device 100 according to this embodiment is capable of printing in nine colors: 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 this embodiment is a head unit consisting of unit heads 30Y, 30Lm, 30Or, 30M, 30Bk, 30Bl, 30Lk, 30C, and 30Lc corresponding to these nine colors. In Figure 2, each of the unit heads 30Y to 30Lc mounted within the carriage 2 is indicated by a two-dot chain line. Each of the unit heads 30Y to 30Lc includes multiple inkjet modules 31. In the example shown in Figure 2, each of the unit heads 30Y to 30Lc includes nine inkjet modules 31.

As shown in Figure 2, the unit heads 30Y-30Lc corresponding to each color are arranged in the following order from left to right along the X-axis direction: Y, Lm, Or, M, Bk, Bl, Lk, C, and Lc. The nine inkjet modules 31 in each unit head 30Y-30Lc are arranged in a staggered pattern along the Y-axis direction. By arranging the inkjet modules 31 in a staggered pattern, it is possible to eject ink of each color at any position within a range spanning almost the entire width of the bottom side of the carriage 2 in the Y-axis direction. Note that in the example shown in Figure 2, only the inkjet module 31 of the leftmost unit head 30Y is shown, and the inkjet modules 31 of the other unit heads 30 are not shown. The configuration of each unit head 30Y-30Lc is not limited to the example shown here. Furthermore, the recording head 3 is not limited to one equipped with unit heads 30Y-30Lc corresponding to the nine colors listed above.

3 is a plan view showing the unit head 30 as seen from the fabric side. Note that the unit heads 30Y to 30Lc that make up the recording head 3 as a head unit all have the same configuration. For this reason, in FIG. 3, the unit head 30 is also simply referred to as the recording head 3.
3, each unit head 30 constituting the recording head 3 has a plurality of (18 in this example) inkjet heads 32. As described above, the unit head 30 in this embodiment has nine inkjet modules 31. Each inkjet module 31 is configured with a pair of two inkjet heads 32.

In the following embodiment, the surface of the recording head 3 (unit head 30) that faces the fabric, which is the recording medium, is referred to as the head top plate 35. The inkjet module 31 is provided exposed on the head top plate 35.
Each inkjet head 32 has a plurality of nozzles 33 that eject ink. The nozzles 33 are arranged in a row in each inkjet head 32, constituting a nozzle surface. In Fig. 3, the direction in which the nozzles 33 are arranged is referred to as the nozzle row direction Ln. In this embodiment, the nozzle row direction Ln coincides with the Y-axis direction (see Figs. 1 and 2) that is perpendicular to the X-axis direction, which is the scanning movement direction of the recording head 3. The nozzle surface is substantially flush with the area of the head top plate 35 other than the nozzle surface.
The inkjet head 32 ejects ink from the nozzles 33 toward the fabric, thereby forming an image on the fabric. Note that the number and arrangement of the inkjet modules 31 are not limited to those described above.

Plate-shaped carriage receivers 43, 44 are provided at both ends of the main scanning device 4 in areas that protrude from the transport device 1. The carriage receivers 43, 44 are attached in a position that is approximately parallel to the transport belt 13 of the transport device 1. When not performing printing, the carriage 2 moves onto the top surface of the carriage receiver 43, which is provided at one end of the main scanning device 4 (left side in the figure).

A moisturizing device 5 is detachably mounted below the carriage support 43. The moisturizing device 5 moisturizes the nozzles 33 of each recording head 3 mounted on the carriage 2. For example, rectangular slits are provided in the carriage support 43 at positions corresponding to the nozzles 33 of the inkjet heads 32 in the carriage 2. Water or moisturizing liquid is contained inside the moisturizing device 5. By positioning the carriage 2 opposite the moisturizing device 5 in the Z-axis direction, the nozzle surfaces of the recording heads 3 in the carriage 2 can be moistened by the moisturizing device 5.

A cleaning unit 7 and a flushing receiving unit 8 are provided on the carriage receiving unit 44 located at the other end of the main scanning device 4 (the right side in the figure). The cleaning unit 7 cleans at least the nozzle surface of the recording head 3 (the surface on which the nozzles 33 are arranged). The flushing receiving unit 8 receives ink ejected from the nozzles 33 during the flushing operation. The flushing operation is performed as needed to prevent clogging of the nozzles 33 of the recording head 3.

Here, the configuration of the cleaning unit 7 will be described with reference to FIGS.
4, in this embodiment, the cleaning section 7 includes a maintenance unit 70 that performs maintenance on at least the nozzle surface of the recording head 3. The cleaning section 7 also includes a guide rail 75 extending in the Y-axis direction, and a unit drive motor 76 that moves the maintenance unit 70 along the guide rail 75. The length of the guide rail 75 in the Y-axis direction is set to a length dimension equal to or greater than the length of the nozzle surface of the recording head 3 in the Y-axis direction.

Figure 5 is a perspective view showing the main components of the maintenance unit 70. The maintenance unit 70 performs maintenance operations on the recording head 3 and is the maintenance means in this embodiment. As shown in Figure 5, the maintenance unit 70 includes a moist roller 71, a roller drive motor 72, a wringer 73, and a liquid reservoir 77. As mentioned above, the recording head 3 in this embodiment has a nozzle surface on the surface facing the fabric (the surface of the head top plate 35). The maintenance unit 70 performs maintenance operations over a wide area of the head top plate 35 (see Figure 3), including the nozzle surface.

The wet roller 71 is formed of, for example, a cylindrical sponge. In this embodiment, the wet roller 71 is a maintenance member that performs maintenance operations on the recording head 3 by wiping.
As described above, the nozzles 33 are arranged on the nozzle surface of the recording head 3 along a direction (Y-axis direction in this embodiment) intersecting the scanning movement direction (X-axis direction) of the recording head 3. The wet roller 71 performs a wiping operation on the nozzle surface along the nozzle row direction Ln of the nozzles 33.

It is preferable that a cleaning liquid is stored inside the wet roller 71. The wet roller 71 is rotatable about an axis 711 provided along the X-axis direction. In this embodiment, the maintenance operation performed by the maintenance unit 70 is divided maintenance.
Here, divided maintenance will be described with reference to Fig. 6. Fig. 6 is a schematic diagram of a recording head 3 for explaining divided maintenance according to an embodiment. For ease of explanation, Fig. 6 simply shows a recording head 3 composed of four unit heads 30. Note that the maintenance operation is similar in the case of a recording head 3 composed of nine unit heads 30 as shown in Figs. 2 and 3.

In Figure 6, the range of the head top plate 35 of each unit head 30 that makes up the recording head 3 is defined as a unit area. That is, in the example shown in Figure 4, etc., the recording head 3 is divided into four unit areas Ar1, Ar2, Ar3, and Ar4, corresponding to each unit head 30. Note that it is not necessary for the unit areas to correspond to the unit heads 30. For example, one unit head 30 may be divided into multiple unit areas, or two or more unit heads 30 may be defined as one unit area.

In this embodiment, the maintenance unit 70 performs divided maintenance for each unit area, and 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 area of the nozzle surface of the recording head 3 in the X-axis direction.
However, when performing divided maintenance, it is preferable that the maintenance operation be performed so as to overlap adjacent unit areas. Therefore, in this embodiment, the length of the wet roller 71 in the X-axis direction is longer than the width of one unit area in the X-axis direction, as shown in FIG. 7 . This allows the maintenance operation to be performed so as to overlap a portion of an adjacent unit area. In FIG. 7 , the area to be maintained when performing divided maintenance on unit area Ar1 is shown in white. Ink or dirt wiped by the wet roller 71 may remain in streaks in areas where the end of the wet roller 71 passes. By performing maintenance while overlapping adjacent unit areas, these streaks of remaining dirt can be eliminated.

The wet roller 71 is rotated by the roller drive motor 72 in the same direction as the movement of the maintenance unit 70 in the Y-axis direction. In Figure 5, the direction in which the maintenance unit 70 moves is indicated by the thick arrow "A." Also in Figure 5, the rotation direction of the wet roller 71 is indicated by the arrow "B." As a result, the wet roller 71 comes into contact in the counter direction with the recording head 3, which moves relative to the maintenance unit 70. This allows the wet roller 71 to powerfully wipe the nozzle surface of the recording head 3.

A liquid reservoir 77 is disposed below the wet roller 71 in the Z-axis direction. Cleaning liquid is stored in the liquid reservoir 77. The lower part of the wet roller 71 is immersed in this cleaning liquid, and as the wet roller 71 rotates, the cleaning liquid is scraped up. In this way, the wet roller 71 cleans the nozzle surface of the recording head 3 while supplying cleaning liquid to the nozzle surface of the recording head 3.
In this embodiment, the roller drive motor 72, the liquid storage section 77 that stores the cleaning liquid, and the like constitute a cleaning means that cleans the wet roller 71. That is, the roller drive motor 72 rotates the wet roller 71, and the wet roller 71 is cleaned by passing it through the cleaning liquid in the liquid storage section 77.

The wringing rod 73 has an axis that is approximately parallel to the axis of the wet roller 71. The wringing rod 73 is positioned near the wet roller 71 in a manner that allows it to be pressed against and separated from the wet roller 71. When the wet roller 71 rotates with the wringing rod 73 pressed against it, ink and cleaning liquid adhering to the wet roller 71 are squeezed out and removed from the wet roller 71. In this embodiment, the wringing rod 73 also functions as a cleaning means for cleaning the wet roller 71.

The flushing receiver 8 comprises, 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 when the carriage 2 is positioned above the flushing receiver 8 during non-recording operation. This causes ink to be ejected from the nozzles 33 and absorbed by the belt of the flushing receiver 8.

The belt of the flushing receiving section 8 is wound around, for example, three rollers (not shown), one of which is positioned so that it is immersed in cleaning liquid stored in a tank (not shown). Therefore, as the belt rotates along the three rollers, part of the belt is immersed in the cleaning liquid, and ink adhering to the belt is washed away by the cleaning liquid.

In this embodiment, an example was given in which the flushing receiving section 8 has a tank, but the present invention is not limited to this. For example, a configuration may be adopted in which the tank is not provided and the ink absorbed during the flushing operation is removed using a squeeze roller or the like.

<Configuration of the control system of the inkjet recording apparatus>
Next, the configuration of a control system of the inkjet recording apparatus 100 according to this embodiment will be described with reference to FIG. 8. FIG. 8 is a block diagram showing an example of the control configuration of the inkjet recording apparatus 100. As shown in FIG. 8, the inkjet recording apparatus 100 includes a control unit 9 and a storage unit 93. The inkjet recording apparatus 100 also includes an operation display unit 96 and an input/output interface 97. The inkjet recording apparatus 100 also includes a head drive unit 301, a transport drive unit 131, and a main scanning device drive unit 401. These units, including the control unit 9, are connected via a bus, for example.

The control unit 9 is a computer including a processor 91 such as a CPU (Central Processing Unit), a memory 92 such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and the like.
The storage unit 93 is configured with a nonvolatile memory or the like, and includes a program storage unit 94 that stores various programs and the like, and a data storage unit 95. The storage unit 93 may be configured with a hard disk drive or the like as a large-capacity storage device. The data storage unit 95 may be a nonvolatile memory such as a flash memory, or a removable portable storage medium such as a memory card.

The control unit 9 has a processor 91 that reads necessary programs, such as system programs, stored in the program storage unit 94 and expands them in the working area of the memory 92. In cooperation with the programs expanded in the memory 92, the control unit 9 controls the operation of each unit and executes various processes. The control unit 9 controls at least the operation of the recording head 3 and the maintenance unit 70. That is, the control unit 9 interrupts the printing operation of the recording head 3 in the middle of a series of print jobs and causes a maintenance operation to be performed. In this way, the control unit 9 causes the inkjet recording device 100 to execute a series of print jobs while repeating the printing operation and maintenance operation.

The operation display unit 96 is configured, for example, by a liquid crystal display (LCD). The operation display unit 96 may also be configured by an organic electroluminescence display (OLED) or other flat display. The operation display unit 96 displays a setting screen or the like for configuring various settings related to printing by the inkjet recording device 100 in response to display instructions from the control unit 9. The operation display unit 96 also has an integrated touch panel. The operation display unit 96 has multiple keys and also functions as an input unit that accepts key operations based on the user's touch operation. The operation display unit 96 accepts input of various user instructions, characters, numbers, and other data. The information accepted by the operation display unit 96 is output to the control unit 9.

The input/output interface 97 is connected to an external device 200 such as a PC (personal computer). The input/output interface 97 receives jobs from the external device 200 and outputs the jobs to the control unit 9.

The head drive unit 301 drives each inkjet head 32 of the recording head 3 mounted inside the carriage 2. This causes ink to be ejected from each nozzle 33, forming an image on the fabric on the conveyor belt 13. The head drive unit 301 and inkjet head 32 make up the recording head 3.

The conveyor drive unit 131 includes a drive motor (not shown). Under the control of the control unit 9, the drive motor of the conveyor drive unit 131 operates, causing the drive roller 11 to rotate and the fabric to be conveyed by the conveyor belt 13.

The main scanning device drive unit 401 controls the current of the stator coils provided on the guide rails 41 and 42, thereby moving the carriage 2 held by the guide rails 41 and 42 along the X-axis direction.

In this embodiment, the control unit 9 also controls the maintenance operation of the nozzle surface of the recording head 3 by the cleaning unit 7. Normally, maintenance operations on the recording head 3 are performed periodically at predetermined time intervals. The control unit 9 starts the maintenance operation by the cleaning unit 7 in accordance with a predetermined periodic maintenance interval MD. Then, it controls the maintenance operation on the recording head 3 by the maintenance unit 70. In this embodiment, the control unit 9 also performs maintenance operations as appropriate at times other than those according to the periodic maintenance interval MD. Here, the control of the maintenance operation by the cleaning unit 7 (maintenance unit 70) by the control unit 9 will be described in detail.

The data storage unit 95 stores, for example, a table that defines the maintenance interval MD. The control unit 9 refers to the information stored in the data storage unit 95 and determines the interval at which to perform the maintenance operation.
Furthermore, normally, when a print job is started, divided maintenance operations m1, m2, ... are performed on the recording head 3 at predetermined time intervals, starting from the unit area located at the very edge. For example, FIG. 9 is a schematic diagram illustrating a normal maintenance operation performed at a predetermined maintenance interval MD. FIG. 9 shows an example in which the unit areas constituting the recording head 3 are unit areas α, β, and γ, starting from the edge. In this case, divided maintenance operation m1 is performed on unit area α, divided maintenance m2 is performed on unit area β, and divided maintenance m3 is performed on unit area γ. After that, after a unit maintenance interval md, the process returns to unit area α and divided maintenance m4 is performed.

9, divided maintenance operations m1, m2, and m3 are performed on three unit areas α, β, and γ during one maintenance interval MD. Here, each unit area α, β, and γ corresponds to a unit head 30. For example, the unit areas α, β, and γ correspond to unit heads 30 that eject Y (yellow), M (magenta), and C (cyan) ink, respectively.
When divided maintenance is performed on a set of unit areas α, β, and γ shown in Figure 9, the maintenance interval MD is the interval from the end of maintenance operation on unit area α to the next maintenance operation on unit area α.

The control unit 9 may change the interval for performing maintenance operations depending on the type of ink ejected by the recording head 3. Examples of types of ink include "reactive dye ink," "disperse dye ink," and "acid ink." "Reactive dye ink" is an ink suitable for fabrics such as cotton and rayon. "Disperse dye ink" is an ink suitable for fabrics such as polyester and acetate. "Acid ink" is an ink suitable for fabrics such as silk. The data storage unit 95 stores a data table or the like that specifies the maintenance interval MD for each type of ink. For example, "acid ink" is relatively less likely to stain the recording head 3 than other inks. For this reason, a longer maintenance interval MD is specified when using "acid ink."

The maintenance interval MD may also be changed depending on the type of fabric used as the recording medium. Examples of types of fabric include polyester, cotton, blends (blends of synthetic and natural fibers, blends of natural and natural fibers, etc.), and silk. The recording medium is not limited to fabric, and may be various types of paper or film. When various types of recording media are used, the maintenance interval MD may be changed depending on the type of recording media. In either case, the data storage unit 95 stores a table or the like that specifies an appropriate maintenance interval MD corresponding to each condition. The control unit 9 references the information stored in the data storage unit 95 and sets the maintenance interval MD as appropriate.

In this embodiment, the control unit 9 causes the maintenance unit 70 to perform divided maintenance at the timing of a scan in which the nozzles ejecting ink in one scan onto the fabric during the printing operation have a small ejection volume. Whether the ejection volume is small or not is determined relatively by the control unit 9.
During maintenance, the printer stops printing and enters a standby state. Because maintenance is performed in the middle of a print job, ink has already been ejected onto the fabric. During standby, this ink spreads on the fabric, causing uneven density, which can lead to a decline in print quality. This uneven density becomes more pronounced if a large amount of ink has been ejected onto the fabric immediately before the maintenance.

In this regard, if the amount of ink ejected onto the fabric is small at the time, the amount of ink ejected onto the fabric will also be small. Therefore, it is thought that the ink will spread relatively little during the waiting time during maintenance operations, and uneven density will be less likely to occur. Note that the control unit 9 determines whether the amount of ink ejected is small, for example, from print job data, etc.

Furthermore, as described above, the recording head 3 of this embodiment forms an image using multiple colors of ink. It is preferable that the control unit 9 executes split maintenance using the maintenance unit 70 for each color forming the image, at the timing of scans in which the amount of ink ejected is small. That is, the control unit 9, for example, monitors print job data at any time, and when there is a scan in which the amount of ink ejected of a certain color is small, executes maintenance operations for the unit area including the unit head 30 corresponding to that color.

For example, when there is a timing for a scan in which the amount of M (magenta) ink ejected is small, control is performed as follows. That is, the control unit 9 controls each part of the device so that the maintenance unit 70 performs divided maintenance on the unit area β corresponding to the unit head 30M that ejects M (magenta). Also, when there is a timing for a scan in which the amount of C (cyan) ink ejected is small, control is performed as follows. That is, the control unit 9 controls each part of the device so that the maintenance unit 70 performs divided maintenance on the unit area γ corresponding to the unit head 30C that ejects C (cyan).

Note that the unit area for which divided maintenance is performed at the timing of a scan with a low amount of M (magenta) ink ejection is not limited to unit area β corresponding to the M (magenta) unit head 30M. Maintenance may be performed on the unit areas that make up a single recording head 3 in order, regardless of the color with a low ink ejection amount. For example, if maintenance is performed on unit areas α, β, and γ in that order, the next order to be maintained is unit area α. In this case, even if the color with a low ink ejection amount is M (magenta) corresponding to unit area β, maintenance may be performed on unit area α in order.

Furthermore, maintenance operations are not limited to those performed periodically at fixed intervals. For example, if the control unit 9 determines that there is a timing for a scan with a low ink ejection volume, it may interrupt the printing operation of the recording head 3 and control the transition to a maintenance operation by the maintenance unit 70. In this case, too, the control unit 9 may determine for each color whether there is a timing for a scan with a low ink ejection volume, or may make this determination by looking at the ink ejection volume for the entire printing operation.

Furthermore, if the maintenance operation performed by the maintenance unit 70 is a periodic maintenance operation performed at predetermined time intervals, the control unit 9 may perform the following control. That is, the control unit 9 controls the printing operation of the recording head 3 so that printing is performed with a lower ink ejection volume than the normal ink ejection volume during the scan immediately prior to performing the periodic maintenance operation. This allows the maintenance operation to be performed with a lower ink ejection volume than normal. Then, after the periodic maintenance operation is completed, the control unit 9 causes the recording head 3 to perform a printing operation using the remaining ejection volume.

In other words, if the number of ejections (nozzle ejection volume) that can be ejected in one scan is 100%, the control unit 9 performs the printing operation at, for example, 50% of the number of ejections in the scan immediately prior to the periodic maintenance operation. Then, the control unit 9 controls the printing operation of the recording head 3 so that the difference of 50% is printed after the maintenance operation is completed. In this case, the fabric is transported in the transport direction (Y-axis direction) after the difference has been printed. In this way, the printing operation is divided so that the number of ejections (nozzle ejection volume) is 100% before and after the maintenance operation. This allows the maintenance operation to be performed with a low ink ejection volume. Note that the amount of printing performed before and after the maintenance operation may be specified as appropriate. It does not necessarily have to be 50% before and after the maintenance operation. For example, it may be divided into 30% before the maintenance operation and 70% after the maintenance operation. Note that if the ink spreads during the waiting time for the maintenance operation, causing uneven density, print quality will be reduced. For this reason, performing maintenance operations with as little ink ejection volume as possible will reduce ink spread and minimize density unevenness. From this perspective, it is preferable to keep the number of ejections (nozzle ejection volume) before maintenance operations at 50% or less.

Furthermore, the control unit 9 causes the maintenance unit 70 to perform a cleaning operation each time a maintenance operation (divided maintenance) is performed for one unit area. The cleaning operation is performed, for example, by the roller drive motor 72 rotating the wet roller 71 and dipping it into the cleaning liquid in the liquid storage unit 77. The cleaning operation can also be performed by pressing a wringer rod 73 against the wet roller 71, for example.

Once the maintenance operation by the maintenance unit 70 is completed, the control unit 9 causes the cleaning operation of the wet roller 71 to be performed in parallel with the printing operation. As shown in FIG. 1, the maintenance unit 70 is provided in an area different from the printing area of the recording head 3. Therefore, while the printing operation is being performed, the cleaning operation of the wet roller 71 can be performed in parallel in preparation for the next maintenance operation. This is preferable because it allows the wet roller 71 to be cleaned before the ink, etc. removed from the recording head solidifies.

The control unit 9 also causes the flushing unit 8 to perform a flushing operation of the nozzles 33 of the inkjet head 32 as appropriate. The control unit 9 determines that a flushing operation is necessary, for example, when the maintenance operation by the cleaning unit 7 does not sufficiently resolve the ejection problems on the nozzle surface of the recording head 3.

<Function and control method of inkjet recording device>
Next, with reference to FIGS. 9 to 12, the control of the printing operation of the recording head 3 performed by the control unit 9 and the control of the maintenance operation by the maintenance unit 70 will be mainly described in detail.
In this embodiment, the control unit 9 interrupts the printing operation of the recording head 3 in the middle of a series of print jobs performed by the recording head 3 and causes the maintenance unit 70 to perform a maintenance operation. This allows the printing operation and the maintenance operation to be repeated.

As mentioned above, the maintenance operation performed by the maintenance unit 70 is divided maintenance, in which the recording head 3 is divided into multiple unit areas and performed for each unit area. Typically, the maintenance operation begins when a print job using the recording head 3 is started and a specified printing operation is performed. Figure 9 shows an example in which the control unit 9 determines that it is time to start the maintenance operation when printing operation p1 is performed. Note that p1 may be the duration of the printing operation, or it may be set based on the amount of characters or images printed.

First, the basic flow of the maintenance operation will be described with reference to FIG.
When it is time to start the maintenance operation, the control unit 9 suspends the printing operation. When performing regular maintenance periodically, the control unit 9 first performs divided maintenance m1 on the first unit area α by the maintenance unit 70. For example, if the recording head 3 is composed of unit areas α, β, and γ, the unit area α is the area located at the very edge. During the maintenance operation, the control unit 9 moves the recording head 3 so that the unit area α is positioned corresponding to the wet roller 71.

Then, the roller drive motor 72 is operated to rotate the wet roller 71 in direction B. At the same time, the unit drive motor 76 is operated to move the maintenance unit 70 in direction A along the Y axis. As a result, the wet roller 71 is pressed against the recording head 3, which is moving relative to the maintenance unit 70, from the counter direction. The nozzle surface of the recording head 3 is then wiped by the wet roller 71, removing stains such as ink. In this embodiment, the wet roller 71 is longer than the width of the unit area α, etc. in the X axis direction. Therefore, as shown in Figure 9, when divided maintenance m1 is performed on a unit area, the area is wiped even to the extent that it overlaps with a portion of an adjacent unit area. The control unit 9 controls this divided maintenance m1 to be completed within 30 seconds, for example.

When divided maintenance m1 is completed, the control unit 9 moves the recording head 3 to the printing area and performs the printing operation for p2. The printing operation for p2 is performed during the unit maintenance interval md1. The maintenance interval MD is the period from when maintenance operations for all unit areas α, β, and γ that make up the recording head 3 are performed until the next maintenance of unit areas α, β, and γ begins. The example shown in Figure 9 illustrates a case where the maintenance interval MD is approximately 30 minutes. Divided maintenance for each unit area is performed at time intervals that are approximately equal divisions of the maintenance interval MD. For example, as shown in Figure 9, if the maintenance interval MD is approximately 30 minutes, the unit maintenance interval md1 is approximately 10 minutes.

While the recording head 3 is performing a printing operation, the control unit 9 performs a cleaning operation on the wet roller 71 in preparation for the next maintenance operation. When the unit maintenance interval md1 has elapsed, the control unit 9 interrupts the printing operation and moves the recording head 3 so that unit area β is positioned corresponding to the wet roller 71. Then, divided maintenance m2 is performed on unit area β. At this time, the overlapping area wiped by divided maintenance m1 is wiped again. This results in no streaky stains due to residue or the like between unit area α and unit area β.

Once divided maintenance m2 is completed, the control unit 9 similarly moves the recording head 3 to the printing area and performs the printing operation of p3. During this time, the wet roller 71 is also cleaned, just as in divided maintenance m1. When the unit maintenance interval md2 has elapsed, the control unit 9 interrupts the printing operation and moves the recording head 3 so that unit area γ is positioned corresponding to the wet roller 71. Then, divided maintenance m3 is performed on unit area γ. In this case, the overlapping area wiped by divided maintenance m2 is wiped as well. This results in no streaks of residue or the like between unit area β and unit area γ.

Once split maintenance m3 is complete, the control unit 9 similarly moves the recording head 3 to the printing area and performs the printing operation for p4. After the unit maintenance interval md3 has elapsed, the control unit 9 again moves the recording head 3 so that unit area α is positioned corresponding to the wet roller 71. Then, split maintenance m4 is performed for unit area α. In this manner, the control unit 9 repeatedly performs printing and maintenance operations until the series of print jobs is completed. For example, in the example shown in Figure 9, after split maintenance m5 for unit area β, the printing operation for p6 is performed, completing the series of print jobs.

In this embodiment, the maintenance unit 70 performs split maintenance at the timing of scans during printing operations in which the amount of ink ejected onto the fabric per scan is small. Specific processing in this embodiment will be described below with reference to Figures 10 to 12. Note that the basic flow of the series of operations, in which printing operations and maintenance operations are repeated during a print job and a cleaning operation is performed after the maintenance operation, is the same as that shown in Figure 9.

In order to perform maintenance operations at the timing of scans with low ink ejection volumes, the control unit 9 may, for example, perform control as shown in Figure 10. That is, if the recording head 3 is made up of unit heads 30 that form images with multiple colors of ink, the control may be performed as follows. In this case, the control unit 9 identifies, for each color that forms an image, for example, from the print job data, the unit head 30 responsible for the color that ejects the least amount of ink. Then, it determines the unit area corresponding to the nozzle surface of that unit head 30 as the target for maintenance operations.

10 , in printing operation p1, the control unit 9 determines that the ejection volume of the unit head 30 corresponding to unit area β has decreased before the maintenance operation. In this case, in divided maintenance m1 after printing operation p1, maintenance is performed on unit area β.
Furthermore, in printing operation p2, the control unit 9 determines that the ejection volume of the unit head 30 corresponding to unit area α has decreased before the maintenance operation. In this case, maintenance is performed on unit area α in divided maintenance m2 after printing operation p2. Similarly, in divided maintenance m3 and onwards, the unit areas including the unit heads 30 corresponding to the colors whose ejection volumes have decreased before the maintenance operation are also the targets of divided maintenance.

In this case, the control unit 9 does not need to follow the order of the unit areas that make up the recording head 3, and instead targets the unit area corresponding to the color for which the scan involved the smallest amount of ink ejected per scan. For example, in the example shown in Figure 10, the control unit 9 targets the unit areas β, α, β, γ, α in the order of maintenance operations. Note that if the same color continues to have a low ink ejection volume, the following control may be performed. For example, if maintenance of the same unit area is performed consecutively, the control unit 9 targets the unit area corresponding to the color with the next smallest ink ejection volume for maintenance. This may prevent uneven maintenance of the areas.

Furthermore, maintenance operations are not limited to being performed at regular, fixed intervals. For example, the control unit 9 may have the maintenance unit 70 perform maintenance operations when it determines, based on print job data or other factors, that the amount of ink ejected is low. In this case, as shown in Figure 11, there is a possibility that the intervals between maintenance operations will vary. However, because maintenance is performed appropriately when the amount of ink ejected is low, the nozzle surface can be kept in a state suitable for printing. Furthermore, even when maintenance operations are performed, it is possible to effectively prevent uneven density caused by ink spreading during standby.

Furthermore, the control unit 9 may proactively create a state in which the amount of ink ejected during printing is small prior to the maintenance operation. That is, if the maintenance operation performed by the maintenance unit 70 is a periodic maintenance operation performed at predetermined time intervals, the control may be as follows. In this case, the control unit 9 controls the printing operation of the recording head 3 so that printing is performed with a lower amount of ink ejected than the normal amount during the scan immediately prior to the periodic maintenance operation.

For example, Figure 12 shows an example in which the scan immediately prior to maintenance in printing operation p1 is performed with approximately half the normal ink ejection volume. In this case, the control unit 9 causes the recording head 3 to print the difference from the normal ejection volume after maintenance m1 is completed. This is done in the same position as the print in the scan immediately prior to maintenance. As shown in Figure 12, in this case, the control unit 9 does not cause the fabric to be transported when printing is performed at approximately 50% immediately prior to maintenance. Then, after maintenance, printing is performed with the difference in ejection volume, and then the fabric is transported in that scan. The control unit 9 then controls each part of the device to start the next printing operation p2. This allows maintenance operations to be performed with a small amount of ink ejected per scan while maintaining a constant interval between maintenance operations (maintenance interval MD in Figure 9).

<Effects>
As described above, in the inkjet recording apparatus 100, which is an image forming apparatus according to this embodiment, the control unit 9 controls the operation of the recording head 3 and the maintenance unit 70 to interrupt the printing operation of the recording head 3 during a series of print jobs and perform a maintenance operation. This allows the print job to be executed by repeatedly repeating the printing operation and the maintenance operation. The maintenance operation according to this embodiment divides the recording head 3 into multiple unit areas, and performs split maintenance on each unit area. This shortens the time required for each maintenance operation. During the maintenance operation, the printing operation is stopped and a standby period is imposed. If ink already ejected onto the recording medium spreads during the standby period, density unevenness occurs, resulting in reduced print quality. The portion of the recording medium that has already been printed may be sent to a dryer. In this case, differences in the degree of drying can further increase the likelihood of density unevenness. In this regard, in this embodiment, the control unit 9 causes the maintenance unit 70 to perform split maintenance at the timing of a scan during the printing operation that ejects a small amount of ink onto the fabric per scan. This reduces the amount of ink ejected onto the fabric before the maintenance operation. Therefore, the amount of ink that spreads during the standby time during the maintenance operation is small and inconspicuous, so that a decrease in the quality of the printed image can be effectively prevented.

For example, if the recording head 3 forms an image using multiple colors of ink, the control unit 9 causes the maintenance unit 70 to perform divided maintenance for each color that forms the image, at the timing of a scan in which the amount of ink ejected in one scan is small.
This reduces the amount of ink of the color that spreads during the standby time during the maintenance operation, making it less likely that uneven density will occur.

Furthermore, for example, when the maintenance operation by the maintenance unit is a periodic maintenance operation performed at predetermined time intervals, the control unit 9 performs the following control. That is, the control unit 9 controls the printing operation of the recording head 3 so that printing is performed with a smaller amount of ink ejection than the original amount in the scan immediately before the periodic maintenance operation. Then, after the periodic maintenance operation is completed, the control unit 9 controls the recording head 3 to print the difference from the original amount of ink ejection. Furthermore, after printing the difference, the control unit 9 controls the fabric to be transported.
The amount of ink ejection that is smaller than the original amount of ink to be ejected in the scan immediately before the maintenance operation is set as appropriate. For example, the control unit 9 controls the recording head so that printing is performed with 50% of the original amount of ink ejection in the scan immediately before the maintenance operation, and after the periodic maintenance operation is completed, printing is performed with 50% of the original amount of ink ejection.
This allows the amount of ink ejected from the recording head to be divided before and after the maintenance operation, reducing the amount of ink ejected before the maintenance operation. As a result, the amount of ink that spreads during the standby time during the maintenance operation is reduced and less noticeable, preventing a decrease in the quality of the printed image.

The maintenance unit 70 of the embodiment also includes a 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, ink and other substances adhering to the recording head 3 can be properly removed.

The recording head 3 of the embodiment has a nozzle surface on the head top plate 35 facing the fabric recording medium, where the nozzles 33 that eject ink are arranged in a row. In the embodiment, the nozzle surface and the rest of the head top plate 35 are substantially flush. There is a risk that ink mist and the like will adhere not only to the nozzle surface but also to the surrounding head top plate 35. In this regard, the maintenance unit 70 of the embodiment performs maintenance operations on the area of the head top plate 35 that includes the nozzle surface. Therefore, when wiping the nozzle surface, ink and the like that has adhered to the head top plate 35 can also be removed.

Furthermore, the control unit 9 of this embodiment causes the maintenance unit 70 to perform divided maintenance in an overlapping manner in adjacent unit areas.
Ink and dirt wiped by the maintenance member may remain in streaks in areas where the edge of the maintenance member passes. In this regard, by performing maintenance while covering a portion of an adjacent unit area, the edge of the unit area can be wiped repeatedly each time maintenance is performed. This makes it possible to prevent streaks of dirt from remaining in areas where the edge of the maintenance member passes.

Furthermore, the print head 3 of the embodiment has a nozzle surface on which the nozzles 33 are arranged in a row along a direction (Y-axis direction) that intersects with the scanning movement direction (X-axis direction) of the print head 3. The maintenance unit 70 performs a wiping operation on the nozzle surface along the nozzle row direction Ln.
This allows maintenance operations to be performed efficiently without leaving any areas unwiped.

The maintenance unit 70 includes a cleaning means for cleaning maintenance members such as the wet roller 71. Then, in divided maintenance by the maintenance unit 70, the control unit 9 causes the cleaning means to perform a cleaning operation of the maintenance members every time a maintenance operation for one unit area is performed.
For example, as in this embodiment, when a unit area is set for each unit head 30 that makes up the recording head 3, the ink color differs for each unit area. Therefore, if a maintenance member that has been used to wipe one unit area is then used to wipe another unit area, there is a risk that ink that has adhered to the maintenance member during maintenance will be transferred to the other unit areas. In this regard, by performing a cleaning operation every time a maintenance operation is performed, it is possible to prevent the recording head from becoming soiled by maintenance.

The cleaning unit of the embodiment includes a roller drive motor that rotates the wet roller 71 and a liquid reservoir 77 that stores the cleaning liquid. The wet roller 71 is rotated and passes through the cleaning liquid in the liquid reservoir 77, thereby performing cleaning.
This allows the wet roller 71 to be cleaned effectively.

In addition, in this embodiment, when the maintenance operation by the maintenance unit 70 is completed, the control unit 9 causes the cleaning unit to perform a cleaning operation of the maintenance member in parallel with the printing operation.
In this way, by performing the printing operation by the recording head 3 and the cleaning operation of the maintenance member in parallel, the maintenance member can be kept clean before the next maintenance operation, and the printing operation and maintenance operation can be performed efficiently.

<Modification>
Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments and that various modifications are possible without departing from the spirit of the present invention.

For example, in the above embodiment, the recording medium is made of fabric, but the present invention is not limited to this.

Furthermore, for example, the number of maintenance members provided in the maintenance unit 70 is not limited to one, and multiple maintenance members each having a width narrower than the area to be maintained may be provided.
13, for example, a single maintenance member 71a may be provided, the width of which is smaller than the width of the unit area, such as approximately half the width of the unit area. In this case, the maintenance member travels back and forth across the unit area multiple times, changing its position in the X-axis direction, for example. In this case, it is preferable that the maintenance member 71a move back and forth so that the wiping areas overlap.

Furthermore, in the above embodiment, the recording head 3 has a nozzle surface in which the nozzles 33 are arranged in a row along a direction (Y-axis direction) that intersects with the scanning movement direction (X-axis direction) of the recording head 3. However, the nozzle row direction Ln of the nozzles 33 provided in the recording head 3 is not limited to this.

Furthermore, the maintenance direction performed by the maintenance unit 70 is not limited to the nozzle row direction Ln. For example, the maintenance unit 70 may perform a wiping operation on the nozzle surface along the scanning movement direction (X-axis direction) of the recording head 3. Figure 14 is a schematic explanatory diagram of a case where the maintenance unit 70 performs maintenance along the scanning movement direction (X-axis direction) of the recording head 3. As shown in Figure 14, in this case, it is preferable that the maintenance member 71b is formed to be longer than the length of the nozzle surface of the recording head 3 in the Y-axis direction. Note that even in this case, maintenance of one unit area may be performed by moving a maintenance member that is shorter than the length of the nozzle surface in the Y-axis direction back and forth multiple times.

In the above embodiment, the maintenance unit 70 of the cleaning unit 7 includes the wet roller 71 as a maintenance member, but the present invention is not limited to this. The cleaning unit 7 may have any configuration as long as it can clean the nozzle surface of the recording head 3.
For example, the maintenance unit 70 may include an elastic member as a maintenance member, and perform the maintenance operation by wiping with the elastic member. The elastic member may be, for example, a blade made of silicone rubber.
In this case, too, ink and the like adhering to the nozzle surface and the like of the head top plate 35 can be removed by wiping the nozzle surface of the recording head 3 with an elastic member such as a blade.

Furthermore, the maintenance unit serving as the maintenance means may perform the maintenance operation by sucking up excess liquid with a suction device.
In this way, even if the maintenance unit uses a vacuum system to wipe away ink adhering to the nozzle surface of the recording head 3, like a vacuum cleaner, the nozzle surface can be properly maintained.

Furthermore, the cleaning means for cleaning the maintenance member is not limited to the examples shown in the embodiment. For example, the cleaning means may include an absorbent body and perform cleaning by pressing the absorbent body against a maintenance member such as a wet roller 71 or a blade.
In this case, stains such as ink adhering to the maintenance member such as the wet roller 71 are removed by being absorbed and adsorbed by the absorbent material, and the maintenance member is restored to a clean state.

The cleaning means may also include a motor that rotates the maintenance member, rotating the maintenance member and using centrifugal force to perform cleaning. In this case, the motor that rotates the maintenance member should be powerful enough to generate centrifugal force through rotation.

Furthermore, if the cleaning means includes a liquid reservoir 77 for storing cleaning liquid, cleaning may be performed by spraying the cleaning liquid in the liquid reservoir onto a maintenance member such as a wet roller 71.

The above-described embodiment has been a detailed and specific description of the configuration of an image forming apparatus (inkjet recording apparatus) for the purpose of explaining the present invention, and the image forming apparatus is not necessarily limited to one having all of the configurations described above.
The present invention is not limited to the embodiments described above and shown in the drawings, and various modifications can be made without departing from the spirit of the invention as defined in the claims.

REFERENCE SIGNS LIST 1 Conveying device 2 Carriage 3 Recording head 32 Inkjet head 33 Nozzle 35 Head top plate 4 Main scanning device 7 Cleaning unit 70 Maintenance unit (maintenance means)
71 Wet roller (maintenance member)
77 Liquid storage unit 9 Control unit 100 Inkjet recording device

Claims (18)

an image forming apparatus comprising: a recording head that performs a printing operation on a recording medium while scanning; a maintenance unit that performs a maintenance operation on the recording head using a maintenance member; and a control unit that controls the operation of the recording head and the maintenance unit, wherein the control unit interrupts the printing operation of the recording head in the middle of a series of print jobs and causes the maintenance unit to perform the maintenance operation, thereby executing the print jobs while repeating the printing operation and the maintenance operation;
the maintenance operation by the maintenance unit is divided maintenance in which the recording head is divided into a plurality of unit areas and is performed for each of the unit areas,
the control unit causes the maintenance unit to perform divided maintenance at a timing when a nozzle ejecting a small amount of ink onto the recording medium in one scan during the printing operation is ejected.
An image forming apparatus characterized by: the recording head forms an image using ink of a plurality of colors,
the control unit causes the maintenance unit to perform divided maintenance for each color forming an image at a timing when a nozzle ejecting ink in one scan has a small ejection amount.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. When the maintenance operation by the maintenance means is a periodic maintenance operation performed at predetermined time intervals,
the control unit controls the printing operation of the recording head so that printing is performed with a smaller amount of ink ejection than the original amount in a scan immediately before a periodic maintenance operation is performed, and after the periodic maintenance operation is completed, controls the printing operation of the recording head so that printing is performed with a difference from the original amount of ink ejection, and causes the recording medium to be conveyed after printing the difference.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. the control unit controls the printing operation of the recording head so that printing is performed with 50% of the original ink ejection amount in a scan immediately before the maintenance operation is performed, and controls the printing operation of the recording head so that printing is performed with 50% of the original ink ejection amount after the periodic maintenance operation is completed.
4. The image forming apparatus according to claim 3, wherein the image forming apparatus is a recording medium. the maintenance means includes a wet sponge as the maintenance member, and the maintenance operation is performed by wiping with the wet sponge.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. the maintenance means includes an elastic member as the maintenance member, and performs the maintenance operation by wiping with the elastic member.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. The maintenance means performs the maintenance operation by sucking up excess liquid using a suction device.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. The recording head has a nozzle surface on a head top plate facing a recording medium, on which nozzles for ejecting ink are arranged in a row,
the maintenance unit performs a maintenance operation on a region of the head top plate including the nozzle surface.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. the control unit causes the maintenance unit to perform divided maintenance in an overlapping manner on adjacent unit areas.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. the recording head has a nozzle surface on which nozzles are arranged in a row along a direction intersecting a scanning movement direction of the recording head;
the maintenance unit performs a wiping operation on the nozzle surface along the nozzle row direction.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. the recording head has a nozzle surface on which nozzles are arranged in a row along a direction intersecting a scanning movement direction of the recording head;
the maintenance unit performs a wiping operation on the nozzle surface along the scanning movement direction of the recording head.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. the maintenance means includes cleaning means for cleaning the maintenance member,
the control unit causes the cleaning unit to perform a cleaning operation of the maintenance member every time the maintenance operation of one unit area is performed in the divided maintenance by the maintenance unit.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. the cleaning means includes an absorbent body, and performs cleaning by pressing the absorbent body against the maintenance member.
13. The image forming apparatus according to claim 12. the cleaning means includes a motor that rotates the maintenance member, and performs cleaning by rotating the maintenance member using centrifugal force.
13. The image forming apparatus according to claim 12. the cleaning means includes a motor that rotates the maintenance member and a liquid reservoir that stores a cleaning liquid, and performs cleaning by rotating the maintenance member and passing it through the cleaning liquid in the liquid reservoir.
13. The image forming apparatus according to claim 12. the maintenance means includes cleaning means for cleaning the maintenance member,
When the maintenance operation by the maintenance unit is completed, the control unit controls the cleaning unit to perform a cleaning operation of the maintenance member in parallel with a printing operation by the recording head.
2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium. In an image forming apparatus including a recording head that performs a printing operation on a recording medium while scanning and a maintenance unit that performs a maintenance operation on the recording head using a maintenance member, a control method for the image forming apparatus is provided, the control method comprising: interrupting the printing operation of the recording head in the middle of a series of print jobs and causing the maintenance unit to perform the maintenance operation, thereby executing the print jobs while repeating the printing operation and the maintenance operation;
the maintenance operation by the maintenance unit is divided maintenance in which the recording head is divided into a plurality of unit areas and is performed for each of the unit areas,
the maintenance unit performs divided maintenance on the maintenance unit at a timing when the nozzles ejecting ink onto the recording medium in one scan during the printing operation have a small ejection amount.
2. A method for controlling an image forming apparatus comprising: A computer of an image forming apparatus including a recording head that performs a printing operation on a recording medium while scanning and a maintenance unit that performs a maintenance operation on the recording head using a maintenance member,
an operation control function is realized that interrupts the printing operation of the recording head in the middle of a series of print jobs and causes the maintenance unit to perform the maintenance operation;
the maintenance operation by the maintenance unit is divided maintenance in which the recording head is divided into a plurality of unit areas and is performed for each of the unit areas,
the operation control function causes the maintenance unit to perform divided maintenance at a timing when a nozzle ejecting a small amount of ink onto the recording medium in one scan during the printing operation is ejected.
A program characterized by: