Ink jet recording device and program

Abstract

To provide an ink jet recording device capable of forming a high precision image on a recording medium conveyed in a roll-to-roll manner.SOLUTION: An ink jet recording device 1 comprises: a conveyance unit 10 that conveys a recording medium M having water absorbency in a conveyance direction in a roll-to-roll manner; an image forming unit 40 that forms an image by ejecting ink onto the recording medium M; and a pretreatment liquid applying unit 20 that applies a pretreatment liquid to the recording medium M. The pretreatment liquid applying unit 20 applies pretreatment liquid equal to 50% or more of the basis weight of the recording medium M onto the recording medium M before image formation by the image forming unit 40.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inkjet printing apparatus and a program. [Background technology]

[0002] Inkjet recording devices are known that record images by ejecting ink from nozzles on a nozzle face of a head and causing the ink to land at a desired position on a recording medium. In general, inkjet recording devices transport a recording medium fixed on a ring-shaped belt with an adhesive by rotating rollers provided inside the belt in the transport direction.

[0003] However, such a belt conveying mechanism makes the inkjet recording device larger and heavier. Furthermore, the adhesive agent uses organic solvents, which are environmentally undesirable. Therefore, for example, Patent Document 1 describes an inkjet recording device that conveys a recording medium using a so-called roll-to-roll method, in which a rolled recording medium is directly drawn and conveyed by another roller, without using a conveying belt. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4333969 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the recording medium is made of absorbent fibers, the recording medium may expand and contract as it absorbs the ink while the ink is being applied to form an image, which may result in misalignment of the ink droplets.

[0006] Figure 6 is a graph summarizing the relationship between the print position in the width direction and the line width when four ink ejection units arranged parallel to the transport direction print lines or dots extending in the transport direction on a recording medium, fabric, measuring 50 cm in the transport direction and 100 cm in the width direction. In the graph in Figure 6, the horizontal axis represents the position from the edge of the recording medium in the width direction. Also, in the graph in Figure 6, the vertical axis represents the line width, i.e., the amount of ink landing deviation. When printing lines, the recording medium absorbs more water than when printing dots, resulting in a greater amount of expansion and contraction. As shown in Figure 6, landing deviation occurs particularly at the edge of the recording medium in the width direction, resulting in a significantly thicker line width.

[0007] The present invention has been made in view of the above circumstances, and its object is to provide an inkjet recording apparatus and a program that are capable of forming a high-precision image on a recording medium transported by a roll-to-roll method. [Means for solving the problem]

[0008] The invention described in claim 1 is an inkjet recording apparatus, a conveying unit that conveys a water-absorbent recording medium in a conveying direction by a roll-to-roll method; an image forming unit that forms an image by ejecting ink onto the recording medium, The image forming unit forms an image on the recording medium on which the pretreatment liquid is applied in an amount of 50% or more by basis weight.

[0009] The invention described in claim 2 is the inkjet recording apparatus described in claim 1, The image forming unit forms an image on the recording medium to which the pretreatment liquid is applied in an amount of 300% or less of basis weight.

[0010] The invention described in claim 3 is the inkjet recording apparatus described in claim 1, The pretreatment liquid contains water as a component.

[0011] The invention described in claim 4 is the inkjet recording apparatus described in claim 1, a wrinkle reduction unit that reduces wrinkles in the recording medium, The wrinkle reduction unit reduces wrinkles on the recording medium before the image formation by the image forming unit.

[0012] The invention described in claim 5 is the inkjet recording apparatus described in claim 1, The pretreatment liquid contains a flocculant.

[0013] The invention described in claim 6 is the inkjet recording apparatus described in claim 1, The pretreatment liquid contains a white pigment.

[0014] The invention described in claim 7 is the inkjet recording apparatus described in claim 1, The pretreatment liquid contains resin particles.

[0015] The invention described in claim 8 is the inkjet recording apparatus described in claim 1, The pretreatment liquid contains a softener.

[0016] The invention described in claim 9 is the inkjet recording apparatus described in claim 1, The recording medium is a fabric.

[0017] The invention described in claim 10 is the inkjet recording apparatus according to any one of claims 1 to 9, A pretreatment liquid application unit is provided to apply the pretreatment liquid to the recording medium.

[0018] The invention described in claim 11 is the inkjet recording apparatus described in claim 10, The pretreatment liquid application unit ejects the pretreatment liquid from a nozzle opening onto the recording medium.

[0019] The invention described in claim 12 is the inkjet recording apparatus described in claim 10, An interval of 2 seconds or more exists between the application of the pretreatment liquid to the recording medium by the pretreatment liquid application unit and the landing of ink on the recording medium by the image forming unit.

[0020] The invention described in claim 13 is the inkjet recording apparatus described in claim 10, an information acquisition unit that acquires at least one of the type, basis weight, and thickness of the recording medium as information about the recording medium; an adjusting unit that adjusts the amount of the pretreatment liquid applied by the pretreatment liquid applying unit in accordance with the information.

[0021] The invention described in claim 14 is the inkjet recording apparatus described in claim 10, an image formation control unit that causes the image forming unit to form an evaluation chart; an expansion / contraction rate acquisition unit that acquires an expansion / contraction rate of the recording medium after the evaluation chart is formed as information about the recording medium; an adjusting unit that adjusts the amount of the pretreatment liquid applied by the pretreatment liquid applying unit in accordance with the information.

[0022] The invention described in claim 15 is the inkjet recording apparatus described in claim 10, The pretreatment liquid application unit is provided on the upstream side of the image forming unit in the transport direction.

[0023] The invention described in claim 16 is the inkjet recording apparatus described in claim 10, a carriage that carries both the pretreatment liquid application unit and the image forming unit, the carriage scans in a width direction perpendicular to the transport direction, When the carriage is scanning, the pretreatment liquid is applied from the pretreatment liquid application unit provided in front of the carriage in the scanning direction, and ink is ejected from the image forming unit provided behind the pretreatment liquid application unit in the scanning direction.

[0024] The invention described in claim 17 is a program, a conveying unit that conveys a water-absorbent recording medium in a conveying direction by a roll-to-roll method; a pretreatment liquid application unit that applies a pretreatment liquid to the recording medium; an image forming unit that forms an image by ejecting ink onto the recording medium, The control unit functions as a control unit that causes the pretreatment liquid application unit to apply the pretreatment liquid to the recording medium in an amount that is 50% or more of the basis weight of the recording medium before the image formation by the image forming unit. [Effects of the Invention]

[0025] According to the present invention, a highly accurate image can be formed on a recording medium transported by a roll-to-roll method. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a side view showing a schematic configuration of an inkjet recording apparatus according to an embodiment of the present invention. [Figure 2] 1 is a block diagram showing main operating elements of an inkjet recording apparatus according to an embodiment of the present invention; [Figure 3] FIG. 2 is a bottom view illustrating the configuration of the pretreatment liquid head unit. [Figure 4] 10 is a graph showing the relationship between the application amount of the pretreatment liquid and the stretch rate for each type of fabric. [Figure 5] FIG. 2 is a diagram illustrating a pretreatment liquid application unit and an image forming unit of a multi-pass system. [Figure 6] 10 is a graph showing the difference in the amount of expansion and contraction depending on the position in the width direction when ink is applied to a recording medium. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples. In the following description, components having the same functions and configurations are designated by the same reference numerals, and their description will be omitted.

[0028] [Overall configuration of inkjet recording device] Fig. 1 is a diagram showing a schematic configuration of an inkjet recording apparatus 1 according to an embodiment of the present invention. Fig. 2 is a functional block diagram of the inkjet recording apparatus 1. The inkjet recording apparatus 1 includes a conveying unit 10, a pretreatment liquid application unit 20, a wrinkle reduction unit 30, an image forming unit 40, and a control unit 50. The inkjet recording apparatus 1 is an apparatus that forms an image by ejecting ink onto a recording medium M that is conveyed.

[0029] In the following description, the X direction, Y direction, and Z direction are the directions shown in Fig. 1. In addition, in the following description, the X direction, Y direction, and Z direction are also referred to as the width direction, conveyance direction, and height direction, respectively.

[0030] (Recording medium) The recording medium M is a continuous, long roll that has water-absorbing properties for the pretreatment liquid described below. The recording medium M is, for example, a fabric. Specifically, plain woven fabric made of cotton or cupra made of cotton is used. Rayon, Lexel, Tencel, Modal, and the like are also used as the recording medium M.

[0031] (Transportation section) The transport unit 10 transports the recording medium M in the transport direction. The transport unit 10 is provided with a draw-out unit 11 and a wind-up unit 12 on both sides in the transport direction. The draw-out unit 11 holds the recording medium M so that it can rotate freely. The wind-up unit 12 winds up the recording medium M drawn out from the draw-out unit 11 in a roll. With this configuration, the transport unit 10 can transport the recording medium M in a roll-to-roll manner.

[0032] Between the draw-out section 11 and the wind-up section 12, a known transport roller may be provided to form a transport path for the recording medium M and apply a predetermined tension to the recording medium M. Also, between the draw-out section 11 and the wind-up section 12, a known platen may be provided to suppress bending of the recording medium M.

[0033] (Pre-treatment liquid application section) The pretreatment liquid application unit 20 applies a predetermined pretreatment liquid to the recording medium M before image formation, thereby expanding or contracting the recording medium M in advance. The pretreatment liquid application unit 20 includes a pretreatment liquid head unit 21, for example.

[0034] {Pretreatment liquid head unit} The pretreatment liquid head unit 21 includes a plurality of pretreatment liquid heads 211 and a carriage 212. Fig. 3 is a bottom view of the entire pretreatment liquid head unit 21. Each pretreatment liquid head 211 has a nozzle row made up of nozzles N arranged in the width direction on a nozzle surface 211a, which is its bottom surface. Each pretreatment liquid head 211 ejects the pretreatment liquid from the nozzles N.

[0035] The arrangement direction of the nozzles N in each pretreatment liquid head 211 is not limited to the width direction, but may be a direction intersecting the transport direction at an angle other than a right angle. Furthermore, the number of pretreatment liquid heads 211 included in the pretreatment liquid head unit 21 is not limited to 16. The number of pretreatment liquid heads 211 may be changed as appropriate depending on the recording width of the image, etc.

[0036] <Head module> The 16 pre-treatment liquid heads 211 are combined in pairs to form eight head modules 211M. The positions of the nozzle rows in each head module 211M in the width direction are adjusted so that the positions of the nozzles N in the width direction do not overlap.

[0037] Each head module 211M fits into an opening provided in a support plate at the bottom of the carriage 212. Each head module 211M is supported by the support plate with the nozzle surface 211a of the pretreatment liquid head 211 exposed from the bottom surface of the support plate. The eight head modules 211M are arranged in a staggered pattern to form a line head, so that the range in which ink can be ejected from the nozzles N is continuously connected in the width direction.

[0038] The arrangement range in the width direction of the nozzles N included in the pretreatment liquid head unit 21 covers the width direction of the image recording area of ​​the recording medium M. The pretreatment liquid head unit 21 is used in a fixed position when recording an image. The pretreatment liquid head unit 21 records an image by a single pass method by sequentially ejecting ink at predetermined intervals to different positions in the transport direction as the recording medium M is transported.

[0039] The ink ejection mechanism for ejecting ink from each nozzle N is not particularly limited, but a piezo-type mechanism using a piezoelectric element can be used. Known piezo-type ink ejection mechanisms include shear mode and vent mode. A shear mode ink ejection mechanism ejects ink by varying the pressure of the ink in the pressure chamber by generating a shear mode type displacement in the piezoelectric element on the wall of the pressure chamber that communicates with the nozzle N. A vent mode ink ejection mechanism ejects ink by varying the pressure of the ink in the pressure chamber by deforming a piezoelectric element that is fixed to a diaphragm that forms the wall of the pressure chamber.

[0040] (Pretreatment liquid) The pretreatment liquid applied by the pretreatment liquid application unit 20 to the recording medium M is, for example, water. However, the pretreatment liquid is not limited to pure water as long as it contains water as a component, and may also contain other components.

[0041] For example, the pretreatment liquid may contain a flocculant. The flocculant aggregates the coloring material contained in the ink ejected by the image forming unit 40. This prevents inter-dot bleeding and show-through. In this way, the pretreatment liquid may contain a component that assists the image formation process, and is not limited to a flocculant, but may also contain a white pigment, resin particles, a softener, or the like.

[0042] (Amount of pre-treatment liquid applied) The preferred amount of pretreatment liquid to be applied by the pretreatment liquid application unit 20 will now be described. Fig. 4 is a graph showing the deformation ratios of the recording media M obtained by forming 20 cm x 20 cm solid images on various recording media M while changing the amount of pretreatment liquid applied. In Fig. 4, the horizontal axis represents the amount of pretreatment liquid. Also, in Fig. 4, the vertical axis represents the deformation ratio (reduction ratio or expansion ratio) of the recording media M.

[0043] As shown in Figure 4, the basis weight of the fabric is 52 g / m2, which is made of ultra-fine cotton yarn (count: 100 × 100). 2 In the case of plain woven cotton, the fabric begins to shrink from the start of application of the pretreatment liquid, and the application amount is 30 g / m 2 The deformation saturates around this point. Also, the basis weight of the thick cotton yarn (count: 20 × 20) is 138 g / m 2 For plain woven cotton, the amount of pre-treatment liquid applied is approximately 18 g / m 2 It starts to shrink from around this point. Also, the basis weight of the cupra (count: 71 x 53) is 104 g / m 2 For satin, the amount of pre-treatment liquid applied is 18g / m 2 It starts to stretch around this point.

[0044] As shown in FIG. 4, the basis weight of the polyester sheet is 62 g / m 2 Pongee and blended fabrics with a basis weight of 117 g / m 2 Since the (T / C) broadcloth does not absorb water, the deformation rate was extremely small (less than 0.01%) even when the pretreatment liquid was applied.

[0045] In this way, when the amount of pretreatment liquid applied by the pretreatment liquid application unit 20 to the recording medium M is 50% or more of the basis weight of the recording medium M, the recording medium M, which has water absorption, at least begins to deform, and depending on the type of fabric, the deformation may reach saturation. This is preferable because it is possible to prevent the recording medium M from expanding or contracting during image formation by the image forming unit 40, i.e., during ink application, which can cause landing misalignment and reduce image quality.

[0046] On the other hand, it is preferable that the amount of pretreatment liquid applied by the pretreatment liquid application unit 20 to the recording medium M is 300% or less of the basis weight of the recording medium M. If the amount of pretreatment liquid applied by the pretreatment liquid application unit 20 to the recording medium M exceeds 300% of the basis weight of the recording medium M, the ink will easily bleed during image formation by the image forming unit 40, resulting in a deterioration in image quality.

[0047] (Wrinkle reduction department) Returning to FIG. 1 , the wrinkle reduction unit 30 is configured to reduce wrinkles that occur on the recording medium M due to the application of the pretreatment liquid by the pretreatment liquid application unit 20. The wrinkle reduction unit 30 is provided upstream of the image forming unit 40 in the transport direction. More specifically, a known tenter stretching device, roller, or the like is used as the wrinkle reduction unit 30. By providing the inkjet recording apparatus 1 with the wrinkle reduction unit 30, it is possible to suppress degradation in image quality caused by deviation in the ink landing position due to wrinkles.

[0048] (Image forming section) The image forming unit 40 ejects ink onto the recording medium M to which the pretreatment liquid has been applied, thereby forming an image on the recording medium M. The image forming unit 40 includes an ink head unit.

[0049] {Ink head unit} The detailed configuration of the ink head unit is substantially the same as that of the pretreatment liquid head unit 21, except that the liquid ejected is ink of each color, and therefore a detailed description thereof will be omitted. The ink head unit ejects ink from its nozzle surface onto the recording medium M at appropriate timing according to the movement of the transport unit 10 that transports the recording medium M, thereby recording an image. The ink head unit is disposed so that its nozzle surface is separated from the recording medium M by a predetermined distance.

[0050] The image forming unit 40 preferably ejects ink so that it lands on the recording medium M at least two seconds after the pretreatment liquid is applied to the recording medium M. This is because it takes about two seconds for the recording medium M to fully expand and contract after the pretreatment liquid is applied to the recording medium M, and if the ink lands in less than two seconds, the effect of suppressing degradation in image quality due to the application of the pretreatment liquid cannot be sufficiently obtained.

[0051] (Control unit) The control unit 50 is a processor that controls the overall operations of the inkjet recording apparatus 1 and the maintenance apparatus 2. The control unit 50 includes a CPU (Central Processing Unit) 51, a RAM (Random Access Memory) 52, a ROM (Read Only Memory) 53, a storage unit 54, and the like.

[0052] {CPU} The CPU 51 reads out various control programs and setting data stored in the ROM 53, stores them in the RAM 52, and executes the programs to perform various arithmetic processing.

[0053] {RAM} The RAM 52 provides a working memory space for the CPU 51 and stores temporary data. The RAM 52 may include a non-volatile memory.

[0054] {ROM} The ROM 53 stores various control programs and setting data executed by the CPU 51. Note that the ROM 53 may be replaced by a rewritable nonvolatile memory such as a flash memory.

[0055] {Storage section} The storage unit 54 stores print jobs input from an external device via the communication unit 64 and image data of images to be recorded related to the print jobs. For example, an HDD (Hard Disk Drive) is used as the storage unit 54. Alternatively, a DRAM (Dynamic Random Access Memory) or the like may be used in combination with the storage unit 54.

[0056] [Effects of this embodiment] As described above, the inkjet recording apparatus 1 according to this embodiment includes a transport unit 10 that transports the water-absorbent recording medium M in a transport direction using a roll-to-roll method. The inkjet recording apparatus 1 also includes an image forming unit 40 that forms an image by ejecting ink onto the recording medium M. The inkjet recording apparatus 1 also includes a pretreatment liquid application unit 20 that applies a pretreatment liquid to the recording medium M. The pretreatment liquid application unit 20 applies the pretreatment liquid to the recording medium M in an amount that is 50% or more of the basis weight of the recording medium M before image formation by the image forming unit 40. This configuration allows the recording medium M to expand and contract in advance using the pretreatment liquid, and then the image can be formed by the image forming unit 40. This makes it possible to prevent the recording medium M from expanding and contracting due to image formation by the image forming unit 40, causing the impact position to shift during image formation and resulting in a deterioration in image quality.

[0057] Furthermore, the inkjet recording apparatus 1 according to this embodiment transports the recording medium M using a roll-to-roll transport unit 10 and does not use a binder, making it more environmentally friendly than inkjet recording apparatuses using a belt transport system. In an inkjet recording apparatus, applying a pretreatment liquid containing a water-soluble polymer as a glue to the recording medium M is another method for preventing the expansion and contraction of the recording medium M due to ink without using a binder. However, this configuration requires applying the glue to the recording medium M in advance and then washing the glue away after image formation, which is time-consuming. On the other hand, the inkjet recording apparatus 1 according to this embodiment is preferable because it only requires applying a specified amount of the pretreatment liquid that is typically applied, thereby achieving the same effect more easily.

[0058] [Other configurations] Although the present invention has been specifically described above based on the embodiments thereof, the present invention is not limited to the above-described embodiments and can be modified in various ways within the scope of the invention as defined in the claims and their equivalents.

[0059] For example, in the above example, the pretreatment liquid application unit 20 applies the pretreatment liquid using an inkjet method, but this is not limiting. For example, the pretreatment liquid application unit 20 may be a tub containing the pretreatment liquid. In this configuration, the pretreatment liquid can be applied by transporting the recording medium M so that the transport unit 10 passes through the tub. Note that in this configuration, the pretreatment liquid application unit 20 preferably has a squeeze roller downstream of the tub in the transport direction, which pressurizes the recording medium M after the pretreatment liquid has been applied. The amount of pretreatment liquid applied to the recording medium M can be adjusted depending on the amount of pressure applied by the squeeze roller.

[0060] Furthermore, although the configuration in which the pretreatment liquid application unit 20 includes only one pretreatment liquid head unit 21 has been exemplified, the present invention is not limited to this. That is, the pretreatment liquid application unit 20 may include multiple pretreatment liquid head units 21. Furthermore, in this configuration, the multiple pretreatment liquid head units 21 may each eject pretreatment liquids with different components. Of course, in this configuration, the application amount of the pretreatment liquid is calculated as the sum of the application amounts of the multiple pretreatment liquid head units 21.

[0061] Furthermore, in the above example, an in-line configuration has been described in which the pretreatment liquid application unit 20 applies the pretreatment liquid to the recording medium M being transported by the transport unit 10, but the present invention is not limited to this. That is, the inkjet recording apparatus 1 may transport the recording medium M, to which the pretreatment liquid has been applied in advance, by the transport unit 10.

[0062] Furthermore, in the above example, the inkjet recording apparatus 1 is configured to include the pretreatment liquid application unit 20 and the image forming unit 40, which are separate units of a single-pass system, but the present invention is not limited to this. That is, the inkjet recording apparatus 1 may be configured to be a multi-pass system. Specifically, as shown in Fig. 5, the pretreatment liquid head unit 21 and the ink head unit may be integrally mounted on a single carriage 212, and the carriage 212 may be scanned in the width direction.

[0063] In this configuration, the pretreatment liquid head unit 21 is disposed outside the ink head unit, at an end in the width direction of the carriage 212. The pretreatment liquid head unit 21 applies the pretreatment liquid only when scanning in the forward direction (to the right in FIG. 5 ), where the pretreatment liquid can be applied before the ink head unit, and does not apply the pretreatment liquid when scanning in the backward direction (to the left in FIG. 5 ), which is opposite to the forward direction. However, if the pretreatment liquid head units 21 are provided at both ends in the width direction of the carriage 212, the pretreatment liquid may be applied from the pretreatment liquid head unit 21 on the front side in the scanning direction, in both the forward direction and the backward direction.

[0064] 4, for fabrics with a large basis weight, the rate of increase in the deformation rate is small, but the amount of application required for the deformation to saturate is large. Therefore, the amount of pretreatment liquid applied by the pretreatment liquid application unit 20 does not need to be uniform. In particular, the control unit 50 may be an information acquisition unit that acquires information about the recording medium M and an adjustment unit that adjusts the amount of pretreatment liquid applied by the pretreatment liquid application unit 20 in accordance with the acquired information. The information about the recording medium M includes, for example, the type, thickness, or basis weight of the recording medium M. For example, when the thickness or basis weight of the recording medium M is relatively large, the control unit 50, which is an adjustment unit, increases the amount of pretreatment liquid applied by the pretreatment liquid application unit 20 accordingly.

[0065] The control unit 50, which is an information acquiring unit, can acquire such information about the recording medium M from print data acquired from, for example, an external device, etc. Alternatively, the control unit 50, which is an information acquiring unit, can acquire such information about the recording medium M from various known sensors provided upstream of the pretreatment liquid application unit 20 in the transport direction.

[0066] Furthermore, the amount of pretreatment liquid to be applied to the recording medium M may be adjusted based on actual data of the expansion / contraction rate acquired in advance. That is, the control unit 50 may be an image formation control unit that causes the image forming unit 40 to form an evaluation chart, an expansion / contraction rate acquisition unit that acquires the expansion / contraction rate of the recording medium M after the evaluation chart has been formed, and an adjustment unit that adjusts the amount of pretreatment liquid applied by the pretreatment liquid application unit 20 in accordance with the acquired information. Specifically, the control unit 50 can acquire the expansion / contraction rate by capturing an image of the formed evaluation chart using a camera sensor or the like provided downstream of the image forming unit 40 and comparing the captured image with image data. [Explanation of symbols]

[0067] 1. Inkjet recording device 10 Conveying section 20 Pre-treatment liquid application section 212 Carriage 30 Wrinkle reduction part 40 Image forming unit 50 control unit (adjustment unit, information acquisition unit, expansion / contraction rate acquisition unit) M Recording medium N Nozzle (nozzle opening)

Claims

1. a conveying unit that conveys a water-absorbent recording medium in a conveying direction by a roll-to-roll method; an image forming unit that forms an image by ejecting ink onto the recording medium, The image forming unit is an inkjet recording apparatus that forms an image on the recording medium on which the pretreatment liquid is applied in an amount of 50% or more by basis weight.

2. The inkjet recording apparatus according to claim 1 , wherein the image forming unit forms an image on the recording medium on which the pretreatment liquid has been applied with a basis weight of 300% or less.

3. The inkjet recording apparatus according to claim 1 , wherein the pretreatment liquid contains water as a component.

4. a wrinkle reduction unit that reduces wrinkles in the recording medium, The inkjet recording apparatus according to claim 1 , wherein the wrinkle reduction unit reduces wrinkles on the recording medium before the image formation by the image forming unit.

5. The inkjet recording apparatus according to claim 1 , wherein the pretreatment liquid contains a coagulant.

6. The inkjet recording apparatus according to claim 1 , wherein the pretreatment liquid contains a white pigment.

7. The inkjet recording apparatus according to claim 1 , wherein the pretreatment liquid contains resin particles.

8. The inkjet recording apparatus according to claim 1 , wherein the pretreatment liquid contains a softening agent.

9. 2. The inkjet recording apparatus according to claim 1, wherein the recording medium is a fabric.

10. The inkjet recording apparatus according to claim 1 , further comprising a pretreatment liquid application unit that applies the pretreatment liquid to the recording medium.

11. The inkjet recording apparatus according to claim 10 , wherein the pretreatment liquid application unit ejects the pretreatment liquid from a nozzle opening onto the recording medium.

12. 11. The inkjet recording apparatus according to claim 10, wherein an interval of 2 seconds or more exists between application of the pretreatment liquid to the recording medium by the pretreatment liquid application unit and impact of ink on the recording medium by the image forming unit.

13. an information acquisition unit that acquires at least one of the type, basis weight, and thickness of the recording medium as information about the recording medium; The inkjet recording apparatus according to claim 10 , further comprising: an adjusting unit that adjusts the amount of the pretreatment liquid applied by the pretreatment liquid applying unit in accordance with the information.

14. an image formation control unit that causes the image forming unit to form an evaluation chart; an expansion / contraction rate acquisition unit that acquires an expansion / contraction rate of the recording medium after the evaluation chart is formed as information about the recording medium; The inkjet recording apparatus according to claim 10 , further comprising: an adjusting unit that adjusts the amount of the pretreatment liquid applied by the pretreatment liquid applying unit in accordance with the information.

15. The inkjet recording apparatus according to claim 10, wherein the pretreatment liquid application unit is provided on the upstream side of the image forming unit in the transport direction.

16. a carriage that carries both the pretreatment liquid application unit and the image forming unit, the carriage scans in a width direction perpendicular to the transport direction, 11. The inkjet recording apparatus according to claim 10, wherein, during scanning of the carriage, the pretreatment liquid is applied from the pretreatment liquid application unit provided in front of the carriage in the scanning direction, and ink is ejected from the image forming unit provided behind the pretreatment liquid application unit in the scanning direction.

17. a conveying unit that conveys a water-absorbent recording medium in a conveying direction by a roll-to-roll method; a pretreatment liquid application unit that applies a pretreatment liquid to the recording medium; an image forming unit that forms an image by ejecting ink onto the recording medium, a program that functions as a control unit to cause the pretreatment liquid application unit to apply the pretreatment liquid to the recording medium in an amount equal to or greater than 50% of the basis weight of the recording medium before the image formation by the image forming unit;

Images