Ink supply device, image forming apparatus, and image forming method

Abstract

To provide an ink supply device for forming an image with ink supply on a recording medium conveyed in one direction by a conveyance device, comprising: an ink head which has a plurality of nozzle openings arrayed along the conveyance direction of the recording medium and jets ink from each nozzle opening; a processing head which has a plurality of nozzle openings arrayed along the conveyance direction of the recording medium and jets processing liquid from each nozzle opening; and a carriage which integrally holds the ink head and the processing head and reciprocally moves in a conveyance width direction vertical to the conveyance direction along the front surface of the recording medium, the carriage holding the ink head and the processing head in a state of being deviated in a superimposed manner with respect to the conveyance direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ink supply device, an image forming apparatus, and an image forming method.

Background Art

[0002] An image forming apparatus that forms an image on a recording medium by supplying ink includes a conveyance device that conveys the recording medium and an ink supply device for supplying ink to the recording medium. Some ink supply devices have a processing liquid head for supplying a pretreatment liquid or a post-treatment liquid for aggregation or fixation of coloring materials contained in the ink to the recording medium. As a technology related to an ink supply device having such a processing liquid head, Patent Document 1 below describes a configuration in which heads for Y, M, C, and K inks are arranged in the head scanning direction, and a protection ink head for discharging a protection ink (post-treatment liquid) is disposed at a position shifted in the conveyance direction of the recording medium. Patent Document 2 also describes a configuration including a first head row having a recording head to which a pretreatment liquid is supplied and a second head row having a recording head to which aqueous ink is supplied on the downstream side in the conveyance direction of the recording medium with respect to the first head row. In the ink supply device having the above configuration, it is said that the supply order of the pretreatment liquid and the ink, or the ink and the post-treatment liquid to the recording medium can be ensured.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in such an ink supply device, since a head for a post-treatment liquid or a head for a pre-treatment is provided without overlapping the ink head in the conveyance direction of the recording medium, it has become a factor in the enlargement of the ink supply device and the enlargement of the image forming apparatus provided with the ink supply device.

[0005] Therefore, an object of the present invention is to provide an ink supply device that can be miniaturized while having a head for a processing liquid supplied on top of the ink, and an image forming apparatus that can be miniaturized by including this ink supply device.

Means for Solving the Problems

[0006] The present invention for achieving such an object is an ink supply device for forming an image by ink supply on a recording medium conveyed in one direction by a conveyance device, the ink supply device including an ink head having a plurality of nozzle openings arranged along the conveyance direction of the recording medium and ejecting ink from each nozzle opening, a processing head having a plurality of nozzle openings arranged along the conveyance direction of the recording medium and ejecting a processing liquid from each nozzle opening, and a carriage that integrally holds the ink head and the processing head and reciprocates in a conveyance width direction perpendicular to the conveyance direction along the surface of the recording medium, wherein the carriage holds the ink head and the processing head in a state where they are shifted with an overlap in the conveyance direction.

Effects of the Invention

[0007] According to the present invention, it is possible to provide an ink supply device that can be miniaturized while having a head for a processing liquid supplied on top of the ink, and an image forming apparatus that can be miniaturized by including this ink supply device.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0009] Hereinafter, each embodiment to which the present invention is applied will be described with reference to the drawings. In each embodiment, the same components are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] ≪First Embodiment≫ First, the first embodiment will be described in the order of an image forming apparatus having an ink supply device and an image forming method.

[0011] <Image Forming Apparatus> FIG. 1 is a configuration diagram of the image forming apparatus 1 of the first embodiment. The image forming apparatus 1 shown in this figure is an apparatus for forming an ink image on the main surface of a recording medium [M]. The recording medium [M] is in the form of a sheet, and may be a single - sheet or a continuous sheet. Also, the recording medium [M] can be made of various materials such as cloth materials like cloth, plain paper, cardboard, thin paper, Japanese paper, special paper, corrugated paper, resin film, building materials, etc. Such an image forming apparatus 1 includes a conveyance device 10 for the recording medium [M], an ink supply device 20, and a control device 30. Hereinafter, the details of these components of the image forming apparatus 1 will be described.

[0012] [Conveyor device 10] The conveyor device 10 is a device for conveying the recording medium [M], and for example, it is of a belt conveyor type as shown in the figure. The conveyor device 10 of the belt conveyor type is configured by looping an endless belt around a plurality of rollers (not shown here). Such a conveyor device 10 uses the outer peripheral surface of the endless belt as the placement surface 10a of the recording medium [M], and by rotating the endless belt by the rotation of the rollers, the sheet-like recording medium [M] fixed to the placement surface 10a by suction is conveyed in the rotation direction of the belt. In the illustrated example, the upward-facing surface of the outer peripheral surface of the endless belt is used as the placement surface 10a of the recording medium [M].

[0013] Also, this conveyor device 10 intermittently conveys the recording medium [M] in the conveyance direction [x] at a predetermined conveyance pitch [p] according to an instruction from the control device 30 described later. Here, this image forming apparatus 1 performs image formation in a multi-pass method. Image formation in the multi-pass method is an image formation method in which ink supply is performed a plurality of times on the same area within the image formation region, and enables the formation of a high-definition image. Therefore, this conveyor device 10 conveys the recording medium [M] at the conveyance pitch [p] set under the conditions for performing image formation in the multi-pass method. Note that the conveyance pitch [p] of the recording medium [M] by the conveyor device 10 will be described in detail in the subsequent image formation method.

[0014] [Ink supply device 20] The ink supply device 20 is of an inkjet type, and is a device that supplies ink in a non-contact manner by ejecting ink onto a recording medium [M] conveyed in a predetermined conveyance direction [x] by a conveyance device 10. Further, this ink supply device 20 is of a scanning type that reciprocates in the conveyance width direction [y] and ejects ink onto the recording medium [M] at each position in the conveyance width direction [y]. Thereby, the supply of ink by the ink supply device 20 can be performed over the conveyance width direction [y] of the placement surface 10a in the conveyance device 10. Here, the conveyance width direction [y] is within a plane parallel to the placement surface 10a and is a direction perpendicular to the conveyance direction [x] of the recording medium [M] by the conveyance device 10. This conveyance width direction [y] is also referred to as the main scanning direction.

[0015] Such an ink supply device 20 is configured to hold an ink head 21 and a pre-treatment head 22 in a predetermined state by a carriage 20a that reciprocates in the conveyance width direction [y].

[0016] Among these, the ink head 21 is provided corresponding to each ink color, and for example, is an ink head 21c for cyan ink, an ink head 21m for magenta ink, an ink head 21y for yellow ink, and an ink head 21k for black ink. These ink heads 21 of each color are arranged in an arbitrarily set color arrangement order along the conveyance width direction [y]. Each color ink supplied from such an ink head 21 is, for example, ink containing at least a pigment, but is not limited thereto and may be, for example, ink containing a dye.

[0017] Further, the pretreatment head 22 is disposed outside the array of the ink heads 21. The pretreatment head 22 has an overlap with the ink heads 21 in the conveyance direction [x], and is disposed with a predetermined shift width [d] shifted upstream in the conveyance direction [x] with respect to the ink heads 21. This shift width [d] is set in consideration of the number of passes in image formation by the multi-pass method. Here, the number of passes is the number of times ink is supplied to the same area within the image formation area. As an example, the shift width [d] corresponds to the conveyance pitch [p] of the recording medium [M] by the conveyance device 10 as shown in the figure, and may coincide with the conveyance pitch [p]. In the drawing, the pretreatment head 22 is disposed on the right side of the ink heads 21, but a configuration in which the pretreatment head 22 is disposed on the left side of the ink heads 21 may also be used.

[0018] The pretreatment liquid supplied from such a pretreatment head 22 includes at least a flocculant when each color ink supplied from each ink head 21 contains a pigment. Here, the flocculant may be any component that aggregates the coloring material in the ink on the surface of the recording medium [M] such as cloth and enhances the fixing property, and is not particularly limited.

[0019] FIG. 2 is a configuration diagram of each head included in the ink supply device of the first embodiment. Each head is an ink head 21 and a pretreatment head 22. As shown in this figure, the ink head 21 and the pretreatment head 22 are each configured as a head set that holds one or a plurality of head members 200 (here, three head members 200). Each head member 200 has a plurality of rows of nozzle openings 201 on one nozzle surface 200a. The nozzle openings 201 are injection openings for ink or pretreatment liquid, and ink or pretreatment liquid is injected from each nozzle opening 201 at respective timings. The timing of the protrusion of the ink or pretreatment liquid from each nozzle opening 201 is controlled by a control device 30 described below.

[0020] The ink head 21 and the pretreatment head 22 hold a plurality of head members 200 such that the nozzle surfaces 200a of the respective head members 200 are arranged on the same plane. Further, the ink head 21 and the pretreatment head 22 hold the plurality of head members 200 in an alternating arrangement such that a plurality of nozzle openings 201 provided in the nozzle surfaces 200a of the held head members 200 are arranged at a predetermined period (interval) in the conveyance direction [x]. Note that the ink head 21 and the pretreatment head 22 may be the same.

[0021] Referring to FIGS. 1 and 2 here, it is assumed that the deviation width [d] between the ink head 21 and the pretreatment head 22 is set in consideration of the number of ink supplies (hereinafter referred to as the number of passes) to the same area within the image formation area in image formation performed by the multi-pass method.

[0022] Furthermore, it is assumed that the deviation width [d] is set in consideration of, in addition to the number of passes, the lengths of the ink head 21 and the pretreatment head 22 in the conveyance direction [x] and the arrangement period of the nozzle openings 201 in the conveyance direction [x].

[0023] [Control device 30] Returning to FIG. 1, the control device 30 controls the driving of the conveyance device 10 and the ink supply device 20. The control of the conveyance device 10 by the control device 30 is the conveyance pitch [p] and the conveyance timing of the recording medium [M]. Further, the control of the ink supply device 20 by the control device 30 is the timing of the reciprocating movement (scanning) in the conveyance width direction [y] of the ink supply device 20 and the timing of discharging ink and the pretreatment liquid from each nozzle opening 201 (see FIG. 2) of the ink head 21 and the pretreatment head 22.

[0024] Such a control device 30 is configured by a computer. The computer is hardware used as a so-called computer. The computer includes a non-volatile storage unit such as a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory), and controls the driving of the conveyance device 10 and the ink supply device 20 based on a program stored in the storage unit to form an image on the recording medium [M].

[0025] In particular, this control device 30 performs image formation in a multi-pass method by controlling the driving of the conveyance device 10 and the ink supply device 20. In this case, the control device 30 supplies the pretreatment liquid and ink a plurality of times to each region having a size corresponding to the conveyance pitch [p] of the recording medium [M]. The drive control of the conveyance device 10 and the ink supply device 20 by such a control device 30 will be described in detail in the following image formation method.

[0026] <Image Formation Method (Part 1)> FIG. 3 is a process diagram for explaining the image formation method (Part 1) by the image forming apparatus 1 according to the first embodiment, and shows an image formation method in a two-pass multi-pass method in which ink is supplied twice to the same region as an example. For simplicity of explanation, only one ink head 21 is shown, and the ink head 21 and the pretreatment head 22 are simplified by showing only one row of nozzle openings 201. The image formation method described with reference to this figure is an image formation method implemented by an image formation program included in the above-described control device 30 (see FIG. 1). Hereinafter, with reference to FIG. 1 above, an example of the image formation method by the image forming apparatus 1 will be described based on FIG. 3.

[0027] As shown in steps (1) to (4) of FIG. 3, the control device 30 intermittently conveys the recording medium [M] in the conveyance direction [x] at a predetermined conveyance pitch [p] by driving the conveyance device 10. The conveyance pitch [p] coincides with the deviation width [d] in the conveyance direction [x] between the ink head 21 and the pre-treatment head 22. In this case, the deviation width [d] and the conveyance pitch [p] are such that, with respect to half of the value obtained by subtracting half of the arrangement period of the nozzle openings 201 from the lengths in the conveyance direction [x] of the ink head 21 and the pre-treatment head 22, half of the arrangement period of the nozzle openings 201 is added.

[0028] In FIG. 3, steps (2) to (4) in which the recording medium [M] is conveyed three times from the start state of step (1) are shown. Also, in the intermittent conveyance of the recording medium [M] by the conveyance device 10, the control device 30 moves the ink supply device 20 in one direction [-y] in the conveyance width direction [y] during the period from the end of conveyance to the start of the next conveyance. And during this movement, the control device 30 divides the arrangement of the nozzle openings 201 in the ink head 21 and the pre-treatment head 22 into at least two regions if it is a two-pass operation, and controls the supply of the ink [In] and the pre-treatment liquid [L1] for each of the divided regions. In steps (1) to (4) as described above, the control device 30 controls the driving of the conveyance device 10 and the ink supply device 20 as follows.

[0029] First, as shown in step (1), the control device 30 conveys and stops the recording medium [M] at a position overlapping at least the upstream side in the conveyance direction [x] of the pre-treatment head 22 by driving the conveyance device 10. In this state, the control device 30 moves the ink supply device 20, which was arranged on the right side of the recording medium [M] in the drawing, in one direction [-y] in the conveyance width direction [y].

[0030] During this movement, the control device 30 supplies the pretreatment liquid [L1] from the nozzle openings 201 provided in the area overlapping the recording medium [M] on the upstream side in the conveyance direction [x] in the pretreatment head 22, and lands the pretreatment liquid [L1] on the recording medium [M]. The supply of the pretreatment liquid [L1] may be continuous or intermittent, and may also be carried out intermittently based on the image data to be formed on the recording medium [M]. The supply of the pretreatment liquid [L1] by the pretreatment head 22 is the same hereinafter.

[0031] Next, as shown in step (2), the control device 30 conveys the recording medium [M] by a conveyance pitch [p] in the conveyance direction [x] by driving the conveyance device 10 and then stops it. At this time, the control device 30 moves the recording medium [M] by, for example, a conveyance pitch [p] that matches the deviation width [d] between the ink head 21 and the pretreatment head 22.

[0032] In this state, the control device 30 moves the ink supply device 20 in the other direction [+y] in the conveyance width direction [y]. At this time, the control device 30 supplies the pretreatment liquid [L1] from the nozzle openings 201 provided in the area overlapping the recording medium [M] in the pretreatment head 22, and lands the pretreatment liquid [L1] on the recording medium [M]. As a result, during the landing period of the pretreatment liquid [L1] in the conveyance direction [x] in the previous step (1), the pretreatment liquid [L1] lands, and the pretreatment liquid [L1] also lands in the area upstream in the conveyance direction [x] from the area where the pretreatment liquid [L1] landed in the previous step (1).

[0033] Also, the control device 30 supplies the ink [In] from the nozzle openings 201 provided in the area overlapping the recording medium [M] in the ink head 21, and lands the ink [In] on the recording medium [M]. The supply of the ink [In] is carried out intermittently based on the image data to be formed on the recording medium [M], and is the same hereinafter. As a result, the ink [In] lands on top of the position where the pretreatment liquid [L1] landed in the previous step (1).

[0034] Thereafter, as shown in step (3) and step (4), by repeating the driving of the conveyance device 10 by the control device 30 and the driving of the ink supply device 20, image formation is performed in a two-pass multi-pass method in which ink [In] is landed on top of the position where the pretreatment liquid [L1] has landed.

[0035] <Image Forming Method (Part 2)> FIG. 4 is a process diagram for explaining an image forming method (Part 2) by the image forming apparatus according to the first embodiment, and is a modified example of the image forming method (Part 1) described with reference to FIG. 3. FIG. 4 shows an image forming method in a four-pass multi-pass method in which ink is supplied four times to the same area as an example. For simplicity of explanation, only one ink head 21 is shown in the figure, and the ink head 21 and the pretreatment head 22 are simplified by showing only one row of nozzle openings 201. The image forming method described with reference to this figure is an image forming method implemented by an image forming program included in the above-described control device 30 (see FIG. 1). Hereinafter, with reference to FIG. 1 above, an example of the image forming method by the image forming apparatus 1 will be described based on FIG. 4.

[0036] As shown in steps (1) to (4) of FIG. 4, the control device 30 intermittently conveys the recording medium [M] at a conveyance pitch [p] in the conveyance direction [x] by driving the conveyance device 10. The conveyance pitch [p] is equal to the deviation width [d] in the conveyance direction [x] between the ink head 21 and the pretreatment head 22. In this case, the deviation width [d] and the conveyance pitch [p] are such that, with respect to 1 / 4 of the value obtained by subtracting 1 / 4 of the arrangement period of the nozzle openings 201 from the lengths of the ink head 21 and the pretreatment head 22 in the conveyance direction [x], 1 / 4 of the arrangement period of the nozzle openings 201 is added.

[0037] In FIG. 4, processes (2) to (4) in which the recording medium [M] is conveyed three times from the start state of process (1) are shown. Also, during the intermittent conveyance of the recording medium [M] by the conveyance device 10, the control device 30 moves the ink supply device 20 in one direction in the conveyance width direction [y] after the conveyance ends and before the next conveyance starts. And during this movement, the control device 30 divides the arrangement of the nozzle openings 201 in the ink head 21 and the pretreatment head 22 into at least four regions if it is a 4-pass, and controls the supply of ink [In] and the pretreatment liquid [L1] for each divided region.

[0038] In such processes (1) to (4), the control device 30 controls the driving of the ink supply device 20 in the same process as the process described above with reference to FIG. 3. Then, by repeating the driving of the conveyance device 10 by the control device 30 and the driving of the ink supply device 20, image formation in a 4-pass multi-pass method in which ink [In] is landed on top of the position where the pretreatment liquid [L1] has landed is performed.

[0039] <Image Forming Method (Part 3)> FIGS. 5 and 6 are process diagrams 1 and 2 for explaining the image forming method (Part 3) by the image forming apparatus of the first embodiment, and are modified examples of the image forming method (Part 2) described with reference to FIG. 4. FIGS. 5 and 6 show an image forming method in a 4-pass multi-pass method in which ink is supplied four times to the same region as an example. For simplicity of explanation, only one ink head 21 is shown, and only the nozzle openings 201 in one row of the ink head 21 and the pretreatment head 22 are shown and simplified. The image forming method described with reference to this figure is an image forming method implemented by the image forming program of the control device 30 (see FIG. 1) described above. Hereinafter, with reference to FIG. 1 above, FIGS. 5 and 6 will be used to explain an example of the image forming method by the image forming apparatus 1.

[0040] As shown in steps (1) to (7) of FIGS. 5 and 6, the control device 30 intermittently conveys the recording medium [M] in the conveyance direction [x] at a predetermined conveyance pitch [p] by driving the conveyance device 10. The conveyance pitch [p] is the same as the image forming method (Part 2) described with reference to FIG. 4. On the other hand, the deviation width [d] is a size obtained by adding the arrangement period of the nozzle openings 201 to the conveyance pitch [p].

[0041] In FIGS. 5 and 6, steps (2) to (7) in which the recording medium [M] is conveyed six times from the start state of step (1) are shown. Further, in the intermittent conveyance of the recording medium [M] by the conveyance device 10, the control device 30 moves the ink supply device 20 in one direction in the conveyance width direction [y] after the conveyance is completed until the next conveyance is started. And at the time of this movement, the control device 30 divides the arrangement of the nozzle openings 201 in the ink head 21 and the pretreatment head 22 into at least four regions if it is a four-pass, and controls the supply of the ink [In] and the pretreatment liquid [L1] for each divided region.

[0042] In such steps (1) to (7), the control device 30 controls the driving of the ink supply device 20 in the same steps as the steps described above with reference to FIG. 3. Then, by repeating the driving of the conveyance device 10 by the control device 30 and the driving of the ink supply device 20, image formation in a multi-pass method of four passes in which the ink [In] is landed on top of the position where the pretreatment liquid [L1] has landed is performed.

[0043] <Effect of the First Embodiment> According to the first embodiment described above, the ink supply device 20 has a configuration in which the ink head 21 and the pretreatment head 22 are shifted with an overlap with respect to the conveyance direction [x] of the recording medium [M]. As a result, compared with a configuration in which the ink head 21 and the pretreatment head 22 are completely shifted with respect to the conveyance direction [x] of the recording medium [M], it is possible to reduce the size of the ink supply device 20 and the image forming apparatus 1. Further, with this configuration, the time interval between the landing of the pretreatment liquid [L1] and the ink [In] on the recording medium [M] can be reduced. As a result, for example, the landed pretreatment liquid [L1] is less likely to be affected by environmental temperature and humidity, and it is possible to achieve uniformization of image quality.

[0044] ≪Second Embodiment≫ FIG. 7 is a configuration diagram of the image forming apparatus 2 according to the second embodiment. The difference between the image forming apparatus 2 shown in this figure and the image forming apparatus 1 (see FIG. 1) of the first embodiment lies in the configuration of the ink supply device 20', and the other configurations are the same. Therefore, the configuration of the ink supply device 20' will be described below.

[0045] [Ink Supply Device 20'] The ink supply device 20' is different from the ink supply device 20 (see FIG. 1) of the first embodiment in that it has a post-treatment head 23 instead of the pretreatment head 22.

[0046] The post-treatment head 23 has the same configuration as the ink head 21 described with reference to FIG. 2. This post-treatment head 23 is disposed outside the array of the ink heads 21. The post-treatment head 23 has an overlap with the ink head 21 in the conveyance direction [x], and is disposed with a predetermined shift width [d'] shifted downstream in the conveyance direction [x] with respect to the ink head 21. This shift width [d'] corresponds to the conveyance pitch [p] of the recording medium [M] by the conveyance device 10 as illustrated as an example, and may coincide with the conveyance pitch [p]. In the drawing, the post-treatment head 23 is disposed on the left side of the ink head 21, but a configuration in which the post-treatment head 23 is disposed on the right side of the ink head 21 may also be used.

[0047] When the ink of each color supplied from each ink head 21 contains a pigment, for example, the post-treatment liquid supplied from each post-treatment head 23 is assumed to contain at least a resin dispersant.

[0048] Here, the deviation width [d'] between the ink head 21 and the post-treatment head 23 is set in consideration of the number of ink supplies (hereinafter referred to as the number of passes) to the same area within the image formation area and the arrangement period of the nozzle openings 201 (see FIG. 2) in the conveyance direction [x] in image formation performed by the multi-pass method. The magnitude of this deviation width [d'] is the same as the magnitude of the deviation width [d] (see FIG. 1) of the pretreatment head 22 with respect to the ink head 21 described in the first embodiment.

[0049] <Image Forming Method> The image forming method by the image forming apparatus 2 of the second embodiment is the same as the image forming method by the image forming apparatus 1 of the first embodiment. Here, FIG. 3 used in the description of the previous first embodiment is also a process diagram for explaining the image forming method (part 1) by the image forming apparatus 2 of the second embodiment. In this FIG. 3, the parentheses in the drawing indicate the reference numerals of the components of the second embodiment. Hereinafter, with reference to the previous FIG. 7, an example of the image forming method in a two-pass multi-pass method by the image forming apparatus 2 will be described based on FIG. 3.

[0050] As shown in steps (1) to (4) of FIG. 3, the control device 30 intermittently conveys the recording medium [M] at a conveyance pitch [p] in the conveyance direction [x] by driving the conveyance device 10. The size of this conveyance pitch [p] is as described above. Further, during the intermittent conveyance of the recording medium [M] by the conveyance device 10, the control device 30 moves the ink supply device 20' in one direction in the conveyance width direction [y]. And during this movement, the control device 30 divides the arrangement of the nozzle openings 201 in the ink head 21 and the post-processing head 23 into at least two regions if it is two-pass, and controls the supply of ink [In] and the post-processing liquid ([L12]) for each divided region. In steps (1) to (4) as described above, the control device 30 controls the driving of the conveyance device 10 and the ink supply device 20' as follows.

[0051] In FIG. 3, steps (2) to (4) in which the recording medium [M] is conveyed three times from the start state of step (1) are shown. In steps (1) to (4) like this, the control device 30 controls the driving of the ink supply device 20' as follows.

[0052] First, as shown in step (1), the control device 30 conveys the recording medium [M] to a position overlapping the upstream side in the conveyance direction [x] of at least the ink head (21) by driving the conveyance device 10 and stops it. In this state, the control device 30 moves the ink supply device 20', which was arranged on the right side of the recording medium [M] in the drawing, in one direction [-y] in the conveyance width direction [y]. At that time, the control device 30 supplies ink ([In]) from the nozzle openings 201 provided in the region overlapping the recording medium [M] on the upstream side in the conveyance direction [x] in the ink head (21), and lands the ink ([In]) on the recording medium [M]. The supply of the ink ([In]) shall be intermittently performed based on the image data. However, in FIG. 3, the ink ([In]) is shown in a continuous supply state.

[0053] Next, as shown in step (2), the control device 30 drives the transport device 10 to transport the recording medium [M] by a transport pitch [p] in the transport direction [x] and then stop. At this time, the control device 30 moves the recording medium [M] by a transport pitch [p] that matches the deviation width ([d']) between the ink head (21) and the post-processing head (23).

[0054] In this state, the control device 30 moves the ink supply device 20' in the other direction [+y] in the transport width direction [y]. At this time, the control device 30 supplies ink ([In]) from the nozzle openings 201 provided in the area overlapping the recording medium [M] at the ink head (21) and lands the ink ([In]) on the recording medium [M]. As a result, during the landing period of the ink ([In]) in the transport direction [x] in the previous step (1), the ink ([In]) lands, and the ink ([In]) also lands in the area upstream in the transport direction [x] from the area where the ink ([In]) landed in the previous step (1).

[0055] Also, the control device 30 supplies the post-processing liquid ([L2]) from the nozzle openings 201 provided in the area overlapping the recording medium [M] at the post-processing head 23 and lands the post-processing liquid ([L2]) on the recording medium [M]. The supply of the post-processing liquid ([L2]) may be continuous or intermittent, and may also be intermittently performed based on the image data formed on this recording medium [M]. The supply of the post-processing liquid ([L2]) by the post-processing head (23) is the same hereinafter. As a result, the post-processing liquid ([L2]) lands on top of the position where the ink ([In]) landed in the previous step (1). However, in FIG. 3, the post-processing liquid ([L2]) shows a state of intermittent supply.

[0056] Thereafter, as shown in step (3) and step (4), by repeating the driving of the transport device 10 by the control device 30 and the driving of the ink supply device 20', image formation in a multi-pass method of two passes in which the post-processing liquid ([L2]) lands on top of the position where the ink ([In]) landed is performed. The above is the same for image formation in a multi-pass method of, for example, four passes, so the description here is omitted.

[0057] <Effects of the Second Embodiment> According to the second embodiment described above, the ink supply device 20' has a configuration in which the ink head 21 and the post-processing head 23 are shifted with an overlap with respect to the conveyance direction [x] of the recording medium [M]. As a result, compared with a configuration in which the ink head 21 and the post-processing head 23 are completely shifted with respect to the conveyance direction [x] of the recording medium [M], it is possible to reduce the size of the ink supply device 20' and the image forming apparatus 2. Further, with this configuration, the time interval between the landing of the ink [In] and the post-processing liquid [L2] on the recording medium [M] can be reduced. As a result, for example, the landed ink [In] is less likely to be affected by the environmental temperature and humidity, and it is possible to achieve uniformization of the image quality.

[0058] <<Third Embodiment>> FIG. 8 is a configuration diagram of the image forming apparatus 3 according to the third embodiment. The image forming apparatus 3 shown in this figure has a configuration combining the image forming apparatus 1 (see FIG. 1) of the first embodiment and the image forming apparatus 2 (see FIG. 7) of the second embodiment. Only the configuration of the ink supply device 20'' is different from other embodiments, and the other configurations are the same. Therefore, the configuration of the ink supply device 20'' will be described below.

[0059] [Ink Supply Device 20''] The ink supply device 20'' has a configuration combining the ink supply device 20 (see FIG. 1) of the first embodiment and the ink supply device 20' of the second embodiment, and includes an ink head 21, a pre-processing head 22, and a post-processing head 23. These ink head 21, pre-processing head 22, and post-processing head 23 are arranged in the configurations and arrangement states described in the first and second embodiments.

[0060] That is, the pre-processing head 22 is disposed outside the array of the ink heads 21, has an overlap with the ink heads 21 in the conveyance direction [x], and is disposed with a predetermined shift width [d] shifted upstream in the conveyance direction [x]. Further, the post-processing head 23 is disposed outside the array of the ink heads 21, has an overlap with the ink heads 21 in the conveyance direction [x], and is disposed with a predetermined shift width [d'] shifted downstream in the conveyance direction [x].

[0061] These shift widths [d], [d'] are as described in the previous first and second embodiments. Also, the shift widths [d] = [d']. In the drawing, the pre-processing head 22 is disposed on the right side of the ink heads 21 and the post-processing head 23 is disposed on the left side, but the reverse may also be possible. Further, both the pre-processing head 22 and the post-processing head 23 may be disposed on the left side or the right side of the ink heads 21. In this case, the pre-processing head 22 and the post-processing head 23 may be arranged in a line along the conveyance direction [x].

[0062] <Image forming method> The image forming method by the image forming apparatus 3 of the third embodiment is the same as the image forming methods by the image forming apparatuses 1, 2 of the first and second embodiments. That is, the control device 30 intermittently conveys the recording medium [M] at a conveyance pitch [p] in the conveyance direction [x] by driving the conveyance device 10. This conveyance pitch [p] coincides with the shift widths [d] = [d'] as an example.

[0063] Further, while the intermittent conveyance of the recording medium [M] by the conveyance device 10 is stopped, the control device 30 supplies ink, a pretreatment liquid, and a post-treatment liquid from the ink supply device 20”. At this time, while moving the ink supply device 20” in either direction in the conveyance width direction [y], first, the pretreatment liquid is supplied from the pretreatment head 22. Next, after the second movement of the ink supply device 20”, the pretreatment liquid is supplied from the pretreatment head 22 and the ink is supplied from the ink head 21. Further, in the third and subsequent movements of the ink supply device 20”, the pretreatment liquid is supplied from the pretreatment head 22, the ink is supplied from the ink head 21, and the post-treatment liquid is supplied from the post-treatment head 23.

[0064] As described above, image formation in a multi-pass method is performed in which ink is landed on top of the position where the pretreatment liquid has landed, and the post-treatment liquid is landed on top of the ink landing position.

[0065] <Effects of the Third Embodiment> According to the third embodiment as described above, it is possible to obtain the effects of the first and second embodiments.

[0066] In each of the above embodiments, the pretreatment liquid, ink, and post-treatment liquid are supplied in both the forward and return paths when the ink supply devices 20, 20’, 20” are reciprocally moved in the conveyance width direction [y]. However, it may be only the forward path or the return path. Thereby, since the inks of each color are supplied to the recording medium [M] in a fixed order according to the arrangement order of the ink heads 21 of each color, the uniformity of the formed image can be enhanced.

[0067] Also, in each of the above embodiments, 2-pass and 4-pass multi-pass drawing are exemplified, but the number of passes in the multi-pass method is not limited.

Explanation of Reference Numerals

[0068] 1, 2, 3… Image forming apparatus 10… Conveyance device 10a… Placing surface 20, 20’, 20”... Ink supply device 20a... Carriage 21... Ink head 21c... Ink head 21k... Ink head 21m... Ink head 21y... Ink head 22... Pretreatment head 23... Post-treatment head 30... Control device 200... Head 200a... Nozzle surface 201... Nozzle opening [d], [d’]... Deviation width [In]... Ink [L1]... Pretreatment liquid [L2]... Post-treatment liquid [M]... Recording medium [p]... Conveying pitch [x]... Conveying direction [y]... Conveying width direction

Claims

1. An ink supply device for forming an image by ink supply on a recording medium conveyed in one direction by a conveying device, an ink head having a plurality of nozzle openings arranged along the conveying direction of the recording medium and ejecting ink from each nozzle opening, a processing head having a plurality of nozzle openings arranged along the conveying direction of the recording medium and ejecting a processing liquid from each nozzle opening, the ink head and the processing head are integrally held, and a carriage that reciprocates in a conveying width direction perpendicular to the conveying direction along the surface of the recording medium is provided, the carriage, as the processing head, holds a pretreatment head that supplies a pretreatment liquid for the ink supplied from the ink head and a post-treatment head that supplies a post-treatment liquid for the ink supplied from the ink head, holds the pretreatment head shifted upstream in the conveying direction with respect to the ink head holds the post-treatment head shifted downstream in the conveying direction with respect to the ink head, the shift width in the conveying direction between the ink head and the pretreatment head and the shift width in the conveying direction between the ink head and the post-treatment head are the same Ink supply device.

2. the carriage holds a plurality of ink heads arranged in the conveying width direction, and holds the processing head outside the arrangement of the plurality of ink heads The ink supply device according to claim 1.

3. The pretreatment liquid contains at least a flocculant The ink supply device according to claim 1.

4. The post-treatment liquid contains at least a resin dispersant The ink supply device according to claim 1.

5. The arrangement period of the nozzle openings in the transport direction of the ink head and the processing head is the same. An ink supply device according to any one of claims 1 to 4.

6. The carriage holds the ink head and the processing head with the arrangement period of the nozzle openings shifted with respect to the transport direction. An ink supply device according to claim 5.

7. The ink contains at least a pigment. An ink supply device according to any one of claims 1 to 6.

8. The recording medium is a fabric. An ink supply device according to any one of claims 1 to 7.

9. An ink supply device according to any one of claims 1 to 8, and a transport device for transporting a recording medium on which an image is formed by ink supply from the ink supply device in the transport direction. An image forming apparatus.

10. The transport device intermittently transports the recording medium in the transport direction at a predetermined transport pitch. An image forming apparatus according to claim 9.

11. During the intermittent transport of the recording medium by the transport device, the ink supply device moves the carriage in the transport width direction, supplies ink from the ink head, and supplies a processing liquid from the processing head. An image forming apparatus according to claim 10.

12. In the ink supply device, the arrays of the nozzle openings in the ink head and the processing head are divided into a plurality of divided regions in the transport direction corresponding to the transport pitch, and the supply of the ink and the processing liquid is controlled for each divided region. An image forming apparatus according to claim 10 or 11.

13. The ink supply device supplies the ink and the processing liquid a plurality of times from different divided areas among the plurality of divided areas of the ink head and the processing head to the same area on the recording medium conveyed by the conveying device. The image forming apparatus according to claim 12.

14. The deviation width of the ink head and the processing head in the conveying direction is a size considering the arrangement period of the nozzle openings and the number of times of supplying the ink and the processing liquid to the same area on the recording medium. The image forming apparatus according to claim 13.

15. The deviation width and the conveying pitch are of the same size. The image forming apparatus according to claim 14.

16. An image forming method using the image forming apparatus according to any one of claims 9 to 15, the conveying device intermittently conveys the recording medium in the conveying direction at a conveying pitch that matches the deviation width of the ink head and the processing head in the conveying direction, the ink supply device moves the carriage in the conveying width direction during the intermittent conveyance of the recording medium by the conveying device, supplies ink from the ink head, and supplies a processing liquid from the processing head. Image forming method.

Images